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c906108c | 1 | \input texinfo @c -*-texinfo-*- |
ecd75fc8 | 2 | @c Copyright (C) 1988-2014 Free Software Foundation, Inc. |
c906108c | 3 | @c |
5d161b24 | 4 | @c %**start of header |
c906108c SS |
5 | @c makeinfo ignores cmds prev to setfilename, so its arg cannot make use |
6 | @c of @set vars. However, you can override filename with makeinfo -o. | |
7 | @setfilename gdb.info | |
8 | @c | |
43662968 | 9 | @c man begin INCLUDE |
c906108c | 10 | @include gdb-cfg.texi |
43662968 | 11 | @c man end |
c906108c | 12 | @c |
c906108c | 13 | @settitle Debugging with @value{GDBN} |
c906108c SS |
14 | @setchapternewpage odd |
15 | @c %**end of header | |
16 | ||
17 | @iftex | |
18 | @c @smallbook | |
19 | @c @cropmarks | |
20 | @end iftex | |
21 | ||
22 | @finalout | |
00595b5e EZ |
23 | @c To avoid file-name clashes between index.html and Index.html, when |
24 | @c the manual is produced on a Posix host and then moved to a | |
25 | @c case-insensitive filesystem (e.g., MS-Windows), we separate the | |
26 | @c indices into two: Concept Index and all the rest. | |
27 | @syncodeindex ky fn | |
28 | @syncodeindex tp fn | |
c906108c | 29 | |
41afff9a | 30 | @c readline appendices use @vindex, @findex and @ftable, |
48e934c6 | 31 | @c annotate.texi and gdbmi use @findex. |
00595b5e | 32 | @syncodeindex vr fn |
c906108c SS |
33 | |
34 | @c !!set GDB manual's edition---not the same as GDB version! | |
9fe8321b | 35 | @c This is updated by GNU Press. |
26829f2b | 36 | @set EDITION Tenth |
c906108c | 37 | |
87885426 FN |
38 | @c !!set GDB edit command default editor |
39 | @set EDITOR /bin/ex | |
c906108c | 40 | |
6c0e9fb3 | 41 | @c THIS MANUAL REQUIRES TEXINFO 4.0 OR LATER. |
c906108c | 42 | |
c906108c | 43 | @c This is a dir.info fragment to support semi-automated addition of |
6d2ebf8b | 44 | @c manuals to an info tree. |
03727ca6 | 45 | @dircategory Software development |
96a2c332 | 46 | @direntry |
03727ca6 | 47 | * Gdb: (gdb). The GNU debugger. |
6cb999f8 | 48 | * gdbserver: (gdb) Server. The GNU debugging server. |
96a2c332 SS |
49 | @end direntry |
50 | ||
a67ec3f4 | 51 | @copying |
43662968 | 52 | @c man begin COPYRIGHT |
ecd75fc8 | 53 | Copyright @copyright{} 1988-2014 Free Software Foundation, Inc. |
c906108c | 54 | |
e9c75b65 | 55 | Permission is granted to copy, distribute and/or modify this document |
4f5d9f07 | 56 | under the terms of the GNU Free Documentation License, Version 1.3 or |
e9c75b65 | 57 | any later version published by the Free Software Foundation; with the |
959acfd1 EZ |
58 | Invariant Sections being ``Free Software'' and ``Free Software Needs |
59 | Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' | |
60 | and with the Back-Cover Texts as in (a) below. | |
c906108c | 61 | |
b8533aec DJ |
62 | (a) The FSF's Back-Cover Text is: ``You are free to copy and modify |
63 | this GNU Manual. Buying copies from GNU Press supports the FSF in | |
64 | developing GNU and promoting software freedom.'' | |
43662968 | 65 | @c man end |
a67ec3f4 JM |
66 | @end copying |
67 | ||
68 | @ifnottex | |
69 | This file documents the @sc{gnu} debugger @value{GDBN}. | |
70 | ||
71 | This is the @value{EDITION} Edition, of @cite{Debugging with | |
72 | @value{GDBN}: the @sc{gnu} Source-Level Debugger} for @value{GDBN} | |
73 | @ifset VERSION_PACKAGE | |
74 | @value{VERSION_PACKAGE} | |
75 | @end ifset | |
76 | Version @value{GDBVN}. | |
77 | ||
78 | @insertcopying | |
79 | @end ifnottex | |
c906108c SS |
80 | |
81 | @titlepage | |
82 | @title Debugging with @value{GDBN} | |
83 | @subtitle The @sc{gnu} Source-Level Debugger | |
c906108c | 84 | @sp 1 |
c906108c | 85 | @subtitle @value{EDITION} Edition, for @value{GDBN} version @value{GDBVN} |
c16158bc JM |
86 | @ifset VERSION_PACKAGE |
87 | @sp 1 | |
88 | @subtitle @value{VERSION_PACKAGE} | |
89 | @end ifset | |
9e9c5ae7 | 90 | @author Richard Stallman, Roland Pesch, Stan Shebs, et al. |
c906108c | 91 | @page |
c906108c SS |
92 | @tex |
93 | {\parskip=0pt | |
c16158bc | 94 | \hfill (Send bugs and comments on @value{GDBN} to @value{BUGURL}.)\par |
c906108c SS |
95 | \hfill {\it Debugging with @value{GDBN}}\par |
96 | \hfill \TeX{}info \texinfoversion\par | |
97 | } | |
98 | @end tex | |
53a5351d | 99 | |
c906108c | 100 | @vskip 0pt plus 1filll |
c906108c | 101 | Published by the Free Software Foundation @* |
c02a867d EZ |
102 | 51 Franklin Street, Fifth Floor, |
103 | Boston, MA 02110-1301, USA@* | |
26829f2b | 104 | ISBN 978-0-9831592-3-0 @* |
e9c75b65 | 105 | |
a67ec3f4 | 106 | @insertcopying |
c906108c SS |
107 | @end titlepage |
108 | @page | |
109 | ||
6c0e9fb3 | 110 | @ifnottex |
6d2ebf8b SS |
111 | @node Top, Summary, (dir), (dir) |
112 | ||
c906108c SS |
113 | @top Debugging with @value{GDBN} |
114 | ||
115 | This file describes @value{GDBN}, the @sc{gnu} symbolic debugger. | |
116 | ||
c16158bc JM |
117 | This is the @value{EDITION} Edition, for @value{GDBN} |
118 | @ifset VERSION_PACKAGE | |
119 | @value{VERSION_PACKAGE} | |
120 | @end ifset | |
121 | Version @value{GDBVN}. | |
c906108c | 122 | |
ecd75fc8 | 123 | Copyright (C) 1988-2014 Free Software Foundation, Inc. |
6d2ebf8b | 124 | |
3fb6a982 JB |
125 | This edition of the GDB manual is dedicated to the memory of Fred |
126 | Fish. Fred was a long-standing contributor to GDB and to Free | |
127 | software in general. We will miss him. | |
128 | ||
6d2ebf8b SS |
129 | @menu |
130 | * Summary:: Summary of @value{GDBN} | |
131 | * Sample Session:: A sample @value{GDBN} session | |
132 | ||
133 | * Invocation:: Getting in and out of @value{GDBN} | |
134 | * Commands:: @value{GDBN} commands | |
135 | * Running:: Running programs under @value{GDBN} | |
136 | * Stopping:: Stopping and continuing | |
bacec72f | 137 | * Reverse Execution:: Running programs backward |
a2311334 | 138 | * Process Record and Replay:: Recording inferior's execution and replaying it |
6d2ebf8b SS |
139 | * Stack:: Examining the stack |
140 | * Source:: Examining source files | |
141 | * Data:: Examining data | |
edb3359d | 142 | * Optimized Code:: Debugging optimized code |
e2e0bcd1 | 143 | * Macros:: Preprocessor Macros |
b37052ae | 144 | * Tracepoints:: Debugging remote targets non-intrusively |
df0cd8c5 | 145 | * Overlays:: Debugging programs that use overlays |
6d2ebf8b SS |
146 | |
147 | * Languages:: Using @value{GDBN} with different languages | |
148 | ||
149 | * Symbols:: Examining the symbol table | |
150 | * Altering:: Altering execution | |
151 | * GDB Files:: @value{GDBN} files | |
152 | * Targets:: Specifying a debugging target | |
6b2f586d | 153 | * Remote Debugging:: Debugging remote programs |
6d2ebf8b SS |
154 | * Configurations:: Configuration-specific information |
155 | * Controlling GDB:: Controlling @value{GDBN} | |
d57a3c85 | 156 | * Extending GDB:: Extending @value{GDBN} |
21c294e6 | 157 | * Interpreters:: Command Interpreters |
c8f4133a | 158 | * TUI:: @value{GDBN} Text User Interface |
6d2ebf8b | 159 | * Emacs:: Using @value{GDBN} under @sc{gnu} Emacs |
7162c0ca | 160 | * GDB/MI:: @value{GDBN}'s Machine Interface. |
c8f4133a | 161 | * Annotations:: @value{GDBN}'s annotation interface. |
4efc6507 | 162 | * JIT Interface:: Using the JIT debugging interface. |
d1feda86 | 163 | * In-Process Agent:: In-Process Agent |
6d2ebf8b SS |
164 | |
165 | * GDB Bugs:: Reporting bugs in @value{GDBN} | |
6d2ebf8b | 166 | |
39037522 TT |
167 | @ifset SYSTEM_READLINE |
168 | * Command Line Editing: (rluserman). Command Line Editing | |
169 | * Using History Interactively: (history). Using History Interactively | |
170 | @end ifset | |
171 | @ifclear SYSTEM_READLINE | |
6d2ebf8b SS |
172 | * Command Line Editing:: Command Line Editing |
173 | * Using History Interactively:: Using History Interactively | |
39037522 | 174 | @end ifclear |
4ceed123 | 175 | * In Memoriam:: In Memoriam |
0869d01b | 176 | * Formatting Documentation:: How to format and print @value{GDBN} documentation |
6d2ebf8b | 177 | * Installing GDB:: Installing GDB |
eb12ee30 | 178 | * Maintenance Commands:: Maintenance Commands |
e0ce93ac | 179 | * Remote Protocol:: GDB Remote Serial Protocol |
f418dd93 | 180 | * Agent Expressions:: The GDB Agent Expression Mechanism |
23181151 DJ |
181 | * Target Descriptions:: How targets can describe themselves to |
182 | @value{GDBN} | |
07e059b5 VP |
183 | * Operating System Information:: Getting additional information from |
184 | the operating system | |
00bf0b85 | 185 | * Trace File Format:: GDB trace file format |
90476074 | 186 | * Index Section Format:: .gdb_index section format |
43662968 | 187 | * Man Pages:: Manual pages |
aab4e0ec AC |
188 | * Copying:: GNU General Public License says |
189 | how you can copy and share GDB | |
6826cf00 | 190 | * GNU Free Documentation License:: The license for this documentation |
00595b5e EZ |
191 | * Concept Index:: Index of @value{GDBN} concepts |
192 | * Command and Variable Index:: Index of @value{GDBN} commands, variables, | |
193 | functions, and Python data types | |
6d2ebf8b SS |
194 | @end menu |
195 | ||
6c0e9fb3 | 196 | @end ifnottex |
c906108c | 197 | |
449f3b6c | 198 | @contents |
449f3b6c | 199 | |
6d2ebf8b | 200 | @node Summary |
c906108c SS |
201 | @unnumbered Summary of @value{GDBN} |
202 | ||
203 | The purpose of a debugger such as @value{GDBN} is to allow you to see what is | |
204 | going on ``inside'' another program while it executes---or what another | |
205 | program was doing at the moment it crashed. | |
206 | ||
207 | @value{GDBN} can do four main kinds of things (plus other things in support of | |
208 | these) to help you catch bugs in the act: | |
209 | ||
210 | @itemize @bullet | |
211 | @item | |
212 | Start your program, specifying anything that might affect its behavior. | |
213 | ||
214 | @item | |
215 | Make your program stop on specified conditions. | |
216 | ||
217 | @item | |
218 | Examine what has happened, when your program has stopped. | |
219 | ||
220 | @item | |
221 | Change things in your program, so you can experiment with correcting the | |
222 | effects of one bug and go on to learn about another. | |
223 | @end itemize | |
224 | ||
49efadf5 | 225 | You can use @value{GDBN} to debug programs written in C and C@t{++}. |
79a6e687 | 226 | For more information, see @ref{Supported Languages,,Supported Languages}. |
c906108c SS |
227 | For more information, see @ref{C,,C and C++}. |
228 | ||
6aecb9c2 JB |
229 | Support for D is partial. For information on D, see |
230 | @ref{D,,D}. | |
231 | ||
cce74817 | 232 | @cindex Modula-2 |
e632838e AC |
233 | Support for Modula-2 is partial. For information on Modula-2, see |
234 | @ref{Modula-2,,Modula-2}. | |
c906108c | 235 | |
f4b8a18d KW |
236 | Support for OpenCL C is partial. For information on OpenCL C, see |
237 | @ref{OpenCL C,,OpenCL C}. | |
238 | ||
cce74817 JM |
239 | @cindex Pascal |
240 | Debugging Pascal programs which use sets, subranges, file variables, or | |
241 | nested functions does not currently work. @value{GDBN} does not support | |
242 | entering expressions, printing values, or similar features using Pascal | |
243 | syntax. | |
c906108c | 244 | |
c906108c SS |
245 | @cindex Fortran |
246 | @value{GDBN} can be used to debug programs written in Fortran, although | |
53a5351d | 247 | it may be necessary to refer to some variables with a trailing |
cce74817 | 248 | underscore. |
c906108c | 249 | |
b37303ee AF |
250 | @value{GDBN} can be used to debug programs written in Objective-C, |
251 | using either the Apple/NeXT or the GNU Objective-C runtime. | |
252 | ||
c906108c SS |
253 | @menu |
254 | * Free Software:: Freely redistributable software | |
984359d2 | 255 | * Free Documentation:: Free Software Needs Free Documentation |
c906108c SS |
256 | * Contributors:: Contributors to GDB |
257 | @end menu | |
258 | ||
6d2ebf8b | 259 | @node Free Software |
79a6e687 | 260 | @unnumberedsec Free Software |
c906108c | 261 | |
5d161b24 | 262 | @value{GDBN} is @dfn{free software}, protected by the @sc{gnu} |
c906108c SS |
263 | General Public License |
264 | (GPL). The GPL gives you the freedom to copy or adapt a licensed | |
265 | program---but every person getting a copy also gets with it the | |
266 | freedom to modify that copy (which means that they must get access to | |
267 | the source code), and the freedom to distribute further copies. | |
268 | Typical software companies use copyrights to limit your freedoms; the | |
269 | Free Software Foundation uses the GPL to preserve these freedoms. | |
270 | ||
271 | Fundamentally, the General Public License is a license which says that | |
272 | you have these freedoms and that you cannot take these freedoms away | |
273 | from anyone else. | |
274 | ||
984359d2 | 275 | @node Free Documentation |
2666264b | 276 | @unnumberedsec Free Software Needs Free Documentation |
959acfd1 EZ |
277 | |
278 | The biggest deficiency in the free software community today is not in | |
279 | the software---it is the lack of good free documentation that we can | |
280 | include with the free software. Many of our most important | |
281 | programs do not come with free reference manuals and free introductory | |
282 | texts. Documentation is an essential part of any software package; | |
283 | when an important free software package does not come with a free | |
284 | manual and a free tutorial, that is a major gap. We have many such | |
285 | gaps today. | |
286 | ||
287 | Consider Perl, for instance. The tutorial manuals that people | |
288 | normally use are non-free. How did this come about? Because the | |
289 | authors of those manuals published them with restrictive terms---no | |
290 | copying, no modification, source files not available---which exclude | |
291 | them from the free software world. | |
292 | ||
293 | That wasn't the first time this sort of thing happened, and it was far | |
294 | from the last. Many times we have heard a GNU user eagerly describe a | |
295 | manual that he is writing, his intended contribution to the community, | |
296 | only to learn that he had ruined everything by signing a publication | |
297 | contract to make it non-free. | |
298 | ||
299 | Free documentation, like free software, is a matter of freedom, not | |
300 | price. The problem with the non-free manual is not that publishers | |
301 | charge a price for printed copies---that in itself is fine. (The Free | |
302 | Software Foundation sells printed copies of manuals, too.) The | |
303 | problem is the restrictions on the use of the manual. Free manuals | |
304 | are available in source code form, and give you permission to copy and | |
305 | modify. Non-free manuals do not allow this. | |
306 | ||
307 | The criteria of freedom for a free manual are roughly the same as for | |
308 | free software. Redistribution (including the normal kinds of | |
309 | commercial redistribution) must be permitted, so that the manual can | |
310 | accompany every copy of the program, both on-line and on paper. | |
311 | ||
312 | Permission for modification of the technical content is crucial too. | |
313 | When people modify the software, adding or changing features, if they | |
314 | are conscientious they will change the manual too---so they can | |
315 | provide accurate and clear documentation for the modified program. A | |
316 | manual that leaves you no choice but to write a new manual to document | |
317 | a changed version of the program is not really available to our | |
318 | community. | |
319 | ||
320 | Some kinds of limits on the way modification is handled are | |
321 | acceptable. For example, requirements to preserve the original | |
322 | author's copyright notice, the distribution terms, or the list of | |
323 | authors, are ok. It is also no problem to require modified versions | |
324 | to include notice that they were modified. Even entire sections that | |
325 | may not be deleted or changed are acceptable, as long as they deal | |
326 | with nontechnical topics (like this one). These kinds of restrictions | |
327 | are acceptable because they don't obstruct the community's normal use | |
328 | of the manual. | |
329 | ||
330 | However, it must be possible to modify all the @emph{technical} | |
331 | content of the manual, and then distribute the result in all the usual | |
332 | media, through all the usual channels. Otherwise, the restrictions | |
333 | obstruct the use of the manual, it is not free, and we need another | |
334 | manual to replace it. | |
335 | ||
336 | Please spread the word about this issue. Our community continues to | |
337 | lose manuals to proprietary publishing. If we spread the word that | |
338 | free software needs free reference manuals and free tutorials, perhaps | |
339 | the next person who wants to contribute by writing documentation will | |
340 | realize, before it is too late, that only free manuals contribute to | |
341 | the free software community. | |
342 | ||
343 | If you are writing documentation, please insist on publishing it under | |
344 | the GNU Free Documentation License or another free documentation | |
345 | license. Remember that this decision requires your approval---you | |
346 | don't have to let the publisher decide. Some commercial publishers | |
347 | will use a free license if you insist, but they will not propose the | |
348 | option; it is up to you to raise the issue and say firmly that this is | |
349 | what you want. If the publisher you are dealing with refuses, please | |
350 | try other publishers. If you're not sure whether a proposed license | |
42584a72 | 351 | is free, write to @email{licensing@@gnu.org}. |
959acfd1 EZ |
352 | |
353 | You can encourage commercial publishers to sell more free, copylefted | |
354 | manuals and tutorials by buying them, and particularly by buying | |
355 | copies from the publishers that paid for their writing or for major | |
356 | improvements. Meanwhile, try to avoid buying non-free documentation | |
357 | at all. Check the distribution terms of a manual before you buy it, | |
358 | and insist that whoever seeks your business must respect your freedom. | |
72c9928d EZ |
359 | Check the history of the book, and try to reward the publishers that |
360 | have paid or pay the authors to work on it. | |
959acfd1 EZ |
361 | |
362 | The Free Software Foundation maintains a list of free documentation | |
363 | published by other publishers, at | |
364 | @url{http://www.fsf.org/doc/other-free-books.html}. | |
365 | ||
6d2ebf8b | 366 | @node Contributors |
96a2c332 SS |
367 | @unnumberedsec Contributors to @value{GDBN} |
368 | ||
369 | Richard Stallman was the original author of @value{GDBN}, and of many | |
370 | other @sc{gnu} programs. Many others have contributed to its | |
371 | development. This section attempts to credit major contributors. One | |
372 | of the virtues of free software is that everyone is free to contribute | |
373 | to it; with regret, we cannot actually acknowledge everyone here. The | |
374 | file @file{ChangeLog} in the @value{GDBN} distribution approximates a | |
c906108c SS |
375 | blow-by-blow account. |
376 | ||
377 | Changes much prior to version 2.0 are lost in the mists of time. | |
378 | ||
379 | @quotation | |
380 | @emph{Plea:} Additions to this section are particularly welcome. If you | |
381 | or your friends (or enemies, to be evenhanded) have been unfairly | |
382 | omitted from this list, we would like to add your names! | |
383 | @end quotation | |
384 | ||
385 | So that they may not regard their many labors as thankless, we | |
386 | particularly thank those who shepherded @value{GDBN} through major | |
387 | releases: | |
7ba3cf9c | 388 | Andrew Cagney (releases 6.3, 6.2, 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0); |
c906108c SS |
389 | Jim Blandy (release 4.18); |
390 | Jason Molenda (release 4.17); | |
391 | Stan Shebs (release 4.14); | |
392 | Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9); | |
393 | Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4); | |
394 | John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); | |
395 | Jim Kingdon (releases 3.5, 3.4, and 3.3); | |
396 | and Randy Smith (releases 3.2, 3.1, and 3.0). | |
397 | ||
398 | Richard Stallman, assisted at various times by Peter TerMaat, Chris | |
399 | Hanson, and Richard Mlynarik, handled releases through 2.8. | |
400 | ||
b37052ae EZ |
401 | Michael Tiemann is the author of most of the @sc{gnu} C@t{++} support |
402 | in @value{GDBN}, with significant additional contributions from Per | |
403 | Bothner and Daniel Berlin. James Clark wrote the @sc{gnu} C@t{++} | |
404 | demangler. Early work on C@t{++} was by Peter TerMaat (who also did | |
405 | much general update work leading to release 3.0). | |
c906108c | 406 | |
b37052ae | 407 | @value{GDBN} uses the BFD subroutine library to examine multiple |
c906108c SS |
408 | object-file formats; BFD was a joint project of David V. |
409 | Henkel-Wallace, Rich Pixley, Steve Chamberlain, and John Gilmore. | |
410 | ||
411 | David Johnson wrote the original COFF support; Pace Willison did | |
412 | the original support for encapsulated COFF. | |
413 | ||
0179ffac | 414 | Brent Benson of Harris Computer Systems contributed DWARF 2 support. |
c906108c SS |
415 | |
416 | Adam de Boor and Bradley Davis contributed the ISI Optimum V support. | |
417 | Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS | |
418 | support. | |
419 | Jean-Daniel Fekete contributed Sun 386i support. | |
420 | Chris Hanson improved the HP9000 support. | |
421 | Noboyuki Hikichi and Tomoyuki Hasei contributed Sony/News OS 3 support. | |
422 | David Johnson contributed Encore Umax support. | |
423 | Jyrki Kuoppala contributed Altos 3068 support. | |
424 | Jeff Law contributed HP PA and SOM support. | |
425 | Keith Packard contributed NS32K support. | |
426 | Doug Rabson contributed Acorn Risc Machine support. | |
427 | Bob Rusk contributed Harris Nighthawk CX-UX support. | |
428 | Chris Smith contributed Convex support (and Fortran debugging). | |
429 | Jonathan Stone contributed Pyramid support. | |
430 | Michael Tiemann contributed SPARC support. | |
431 | Tim Tucker contributed support for the Gould NP1 and Gould Powernode. | |
432 | Pace Willison contributed Intel 386 support. | |
433 | Jay Vosburgh contributed Symmetry support. | |
a37295f9 | 434 | Marko Mlinar contributed OpenRISC 1000 support. |
c906108c | 435 | |
1104b9e7 | 436 | Andreas Schwab contributed M68K @sc{gnu}/Linux support. |
c906108c SS |
437 | |
438 | Rich Schaefer and Peter Schauer helped with support of SunOS shared | |
439 | libraries. | |
440 | ||
441 | Jay Fenlason and Roland McGrath ensured that @value{GDBN} and GAS agree | |
442 | about several machine instruction sets. | |
443 | ||
444 | Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped develop | |
445 | remote debugging. Intel Corporation, Wind River Systems, AMD, and ARM | |
446 | contributed remote debugging modules for the i960, VxWorks, A29K UDI, | |
447 | and RDI targets, respectively. | |
448 | ||
449 | Brian Fox is the author of the readline libraries providing | |
450 | command-line editing and command history. | |
451 | ||
7a292a7a SS |
452 | Andrew Beers of SUNY Buffalo wrote the language-switching code, the |
453 | Modula-2 support, and contributed the Languages chapter of this manual. | |
c906108c | 454 | |
5d161b24 | 455 | Fred Fish wrote most of the support for Unix System Vr4. |
b37052ae | 456 | He also enhanced the command-completion support to cover C@t{++} overloaded |
c906108c | 457 | symbols. |
c906108c | 458 | |
f24c5e49 KI |
459 | Hitachi America (now Renesas America), Ltd. sponsored the support for |
460 | H8/300, H8/500, and Super-H processors. | |
c906108c SS |
461 | |
462 | NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx processors. | |
463 | ||
f24c5e49 KI |
464 | Mitsubishi (now Renesas) sponsored the support for D10V, D30V, and M32R/D |
465 | processors. | |
c906108c SS |
466 | |
467 | Toshiba sponsored the support for the TX39 Mips processor. | |
468 | ||
469 | Matsushita sponsored the support for the MN10200 and MN10300 processors. | |
470 | ||
96a2c332 | 471 | Fujitsu sponsored the support for SPARClite and FR30 processors. |
c906108c SS |
472 | |
473 | Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware | |
474 | watchpoints. | |
475 | ||
476 | Michael Snyder added support for tracepoints. | |
477 | ||
478 | Stu Grossman wrote gdbserver. | |
479 | ||
480 | Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made | |
96a2c332 | 481 | nearly innumerable bug fixes and cleanups throughout @value{GDBN}. |
c906108c SS |
482 | |
483 | The following people at the Hewlett-Packard Company contributed | |
484 | support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0 | |
b37052ae | 485 | (narrow mode), HP's implementation of kernel threads, HP's aC@t{++} |
d0d5df6f AC |
486 | compiler, and the Text User Interface (nee Terminal User Interface): |
487 | Ben Krepp, Richard Title, John Bishop, Susan Macchia, Kathy Mann, | |
488 | Satish Pai, India Paul, Steve Rehrauer, and Elena Zannoni. Kim Haase | |
489 | provided HP-specific information in this manual. | |
c906108c | 490 | |
b37052ae EZ |
491 | DJ Delorie ported @value{GDBN} to MS-DOS, for the DJGPP project. |
492 | Robert Hoehne made significant contributions to the DJGPP port. | |
493 | ||
96a2c332 SS |
494 | Cygnus Solutions has sponsored @value{GDBN} maintenance and much of its |
495 | development since 1991. Cygnus engineers who have worked on @value{GDBN} | |
2df3850c JM |
496 | fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin |
497 | Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim | |
498 | Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler, | |
499 | Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek | |
500 | Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In | |
501 | addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton, | |
502 | JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug | |
503 | Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff | |
504 | Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner, | |
505 | Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin | |
506 | Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela | |
507 | Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David | |
508 | Zuhn have made contributions both large and small. | |
c906108c | 509 | |
ffed4509 AC |
510 | Andrew Cagney, Fernando Nasser, and Elena Zannoni, while working for |
511 | Cygnus Solutions, implemented the original @sc{gdb/mi} interface. | |
512 | ||
e2e0bcd1 JB |
513 | Jim Blandy added support for preprocessor macros, while working for Red |
514 | Hat. | |
c906108c | 515 | |
a9967aef AC |
516 | Andrew Cagney designed @value{GDBN}'s architecture vector. Many |
517 | people including Andrew Cagney, Stephane Carrez, Randolph Chung, Nick | |
518 | Duffek, Richard Henderson, Mark Kettenis, Grace Sainsbury, Kei | |
519 | Sakamoto, Yoshinori Sato, Michael Snyder, Andreas Schwab, Jason | |
520 | Thorpe, Corinna Vinschen, Ulrich Weigand, and Elena Zannoni, helped | |
521 | with the migration of old architectures to this new framework. | |
522 | ||
c5e30d01 AC |
523 | Andrew Cagney completely re-designed and re-implemented @value{GDBN}'s |
524 | unwinder framework, this consisting of a fresh new design featuring | |
525 | frame IDs, independent frame sniffers, and the sentinel frame. Mark | |
526 | Kettenis implemented the @sc{dwarf 2} unwinder, Jeff Johnston the | |
527 | libunwind unwinder, and Andrew Cagney the dummy, sentinel, tramp, and | |
db2e3e2e | 528 | trad unwinders. The architecture-specific changes, each involving a |
c5e30d01 AC |
529 | complete rewrite of the architecture's frame code, were carried out by |
530 | Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane | |
531 | Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel | |
532 | Jacobowitz, Jeff Johnston, Mark Kettenis, Theodore A. Roth, Kei | |
533 | Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich | |
534 | Weigand. | |
535 | ||
ca3bf3bd DJ |
536 | Christian Zankel, Ross Morley, Bob Wilson, and Maxim Grigoriev from |
537 | Tensilica, Inc.@: contributed support for Xtensa processors. Others | |
538 | who have worked on the Xtensa port of @value{GDBN} in the past include | |
539 | Steve Tjiang, John Newlin, and Scott Foehner. | |
540 | ||
08be9d71 ME |
541 | Michael Eager and staff of Xilinx, Inc., contributed support for the |
542 | Xilinx MicroBlaze architecture. | |
543 | ||
6d2ebf8b | 544 | @node Sample Session |
c906108c SS |
545 | @chapter A Sample @value{GDBN} Session |
546 | ||
547 | You can use this manual at your leisure to read all about @value{GDBN}. | |
548 | However, a handful of commands are enough to get started using the | |
549 | debugger. This chapter illustrates those commands. | |
550 | ||
551 | @iftex | |
552 | In this sample session, we emphasize user input like this: @b{input}, | |
553 | to make it easier to pick out from the surrounding output. | |
554 | @end iftex | |
555 | ||
556 | @c FIXME: this example may not be appropriate for some configs, where | |
557 | @c FIXME...primary interest is in remote use. | |
558 | ||
559 | One of the preliminary versions of @sc{gnu} @code{m4} (a generic macro | |
560 | processor) exhibits the following bug: sometimes, when we change its | |
561 | quote strings from the default, the commands used to capture one macro | |
562 | definition within another stop working. In the following short @code{m4} | |
563 | session, we define a macro @code{foo} which expands to @code{0000}; we | |
564 | then use the @code{m4} built-in @code{defn} to define @code{bar} as the | |
565 | same thing. However, when we change the open quote string to | |
566 | @code{<QUOTE>} and the close quote string to @code{<UNQUOTE>}, the same | |
567 | procedure fails to define a new synonym @code{baz}: | |
568 | ||
569 | @smallexample | |
570 | $ @b{cd gnu/m4} | |
571 | $ @b{./m4} | |
572 | @b{define(foo,0000)} | |
573 | ||
574 | @b{foo} | |
575 | 0000 | |
576 | @b{define(bar,defn(`foo'))} | |
577 | ||
578 | @b{bar} | |
579 | 0000 | |
580 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
581 | ||
582 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
583 | @b{baz} | |
c8aa23ab | 584 | @b{Ctrl-d} |
c906108c SS |
585 | m4: End of input: 0: fatal error: EOF in string |
586 | @end smallexample | |
587 | ||
588 | @noindent | |
589 | Let us use @value{GDBN} to try to see what is going on. | |
590 | ||
c906108c SS |
591 | @smallexample |
592 | $ @b{@value{GDBP} m4} | |
593 | @c FIXME: this falsifies the exact text played out, to permit smallbook | |
594 | @c FIXME... format to come out better. | |
595 | @value{GDBN} is free software and you are welcome to distribute copies | |
5d161b24 | 596 | of it under certain conditions; type "show copying" to see |
c906108c | 597 | the conditions. |
5d161b24 | 598 | There is absolutely no warranty for @value{GDBN}; type "show warranty" |
c906108c SS |
599 | for details. |
600 | ||
601 | @value{GDBN} @value{GDBVN}, Copyright 1999 Free Software Foundation, Inc... | |
602 | (@value{GDBP}) | |
603 | @end smallexample | |
c906108c SS |
604 | |
605 | @noindent | |
606 | @value{GDBN} reads only enough symbol data to know where to find the | |
607 | rest when needed; as a result, the first prompt comes up very quickly. | |
608 | We now tell @value{GDBN} to use a narrower display width than usual, so | |
609 | that examples fit in this manual. | |
610 | ||
611 | @smallexample | |
612 | (@value{GDBP}) @b{set width 70} | |
613 | @end smallexample | |
614 | ||
615 | @noindent | |
616 | We need to see how the @code{m4} built-in @code{changequote} works. | |
617 | Having looked at the source, we know the relevant subroutine is | |
618 | @code{m4_changequote}, so we set a breakpoint there with the @value{GDBN} | |
619 | @code{break} command. | |
620 | ||
621 | @smallexample | |
622 | (@value{GDBP}) @b{break m4_changequote} | |
623 | Breakpoint 1 at 0x62f4: file builtin.c, line 879. | |
624 | @end smallexample | |
625 | ||
626 | @noindent | |
627 | Using the @code{run} command, we start @code{m4} running under @value{GDBN} | |
628 | control; as long as control does not reach the @code{m4_changequote} | |
629 | subroutine, the program runs as usual: | |
630 | ||
631 | @smallexample | |
632 | (@value{GDBP}) @b{run} | |
633 | Starting program: /work/Editorial/gdb/gnu/m4/m4 | |
634 | @b{define(foo,0000)} | |
635 | ||
636 | @b{foo} | |
637 | 0000 | |
638 | @end smallexample | |
639 | ||
640 | @noindent | |
641 | To trigger the breakpoint, we call @code{changequote}. @value{GDBN} | |
642 | suspends execution of @code{m4}, displaying information about the | |
643 | context where it stops. | |
644 | ||
645 | @smallexample | |
646 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
647 | ||
5d161b24 | 648 | Breakpoint 1, m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
649 | at builtin.c:879 |
650 | 879 if (bad_argc(TOKEN_DATA_TEXT(argv[0]),argc,1,3)) | |
651 | @end smallexample | |
652 | ||
653 | @noindent | |
654 | Now we use the command @code{n} (@code{next}) to advance execution to | |
655 | the next line of the current function. | |
656 | ||
657 | @smallexample | |
658 | (@value{GDBP}) @b{n} | |
659 | 882 set_quotes((argc >= 2) ? TOKEN_DATA_TEXT(argv[1])\ | |
660 | : nil, | |
661 | @end smallexample | |
662 | ||
663 | @noindent | |
664 | @code{set_quotes} looks like a promising subroutine. We can go into it | |
665 | by using the command @code{s} (@code{step}) instead of @code{next}. | |
666 | @code{step} goes to the next line to be executed in @emph{any} | |
667 | subroutine, so it steps into @code{set_quotes}. | |
668 | ||
669 | @smallexample | |
670 | (@value{GDBP}) @b{s} | |
671 | set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
672 | at input.c:530 | |
673 | 530 if (lquote != def_lquote) | |
674 | @end smallexample | |
675 | ||
676 | @noindent | |
677 | The display that shows the subroutine where @code{m4} is now | |
678 | suspended (and its arguments) is called a stack frame display. It | |
679 | shows a summary of the stack. We can use the @code{backtrace} | |
680 | command (which can also be spelled @code{bt}), to see where we are | |
681 | in the stack as a whole: the @code{backtrace} command displays a | |
682 | stack frame for each active subroutine. | |
683 | ||
684 | @smallexample | |
685 | (@value{GDBP}) @b{bt} | |
686 | #0 set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
687 | at input.c:530 | |
5d161b24 | 688 | #1 0x6344 in m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
689 | at builtin.c:882 |
690 | #2 0x8174 in expand_macro (sym=0x33320) at macro.c:242 | |
691 | #3 0x7a88 in expand_token (obs=0x0, t=209696, td=0xf7fffa30) | |
692 | at macro.c:71 | |
693 | #4 0x79dc in expand_input () at macro.c:40 | |
694 | #5 0x2930 in main (argc=0, argv=0xf7fffb20) at m4.c:195 | |
695 | @end smallexample | |
696 | ||
697 | @noindent | |
698 | We step through a few more lines to see what happens. The first two | |
699 | times, we can use @samp{s}; the next two times we use @code{n} to avoid | |
700 | falling into the @code{xstrdup} subroutine. | |
701 | ||
702 | @smallexample | |
703 | (@value{GDBP}) @b{s} | |
704 | 0x3b5c 532 if (rquote != def_rquote) | |
705 | (@value{GDBP}) @b{s} | |
706 | 0x3b80 535 lquote = (lq == nil || *lq == '\0') ? \ | |
707 | def_lquote : xstrdup(lq); | |
708 | (@value{GDBP}) @b{n} | |
709 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
710 | : xstrdup(rq); | |
711 | (@value{GDBP}) @b{n} | |
712 | 538 len_lquote = strlen(rquote); | |
713 | @end smallexample | |
714 | ||
715 | @noindent | |
716 | The last line displayed looks a little odd; we can examine the variables | |
717 | @code{lquote} and @code{rquote} to see if they are in fact the new left | |
718 | and right quotes we specified. We use the command @code{p} | |
719 | (@code{print}) to see their values. | |
720 | ||
721 | @smallexample | |
722 | (@value{GDBP}) @b{p lquote} | |
723 | $1 = 0x35d40 "<QUOTE>" | |
724 | (@value{GDBP}) @b{p rquote} | |
725 | $2 = 0x35d50 "<UNQUOTE>" | |
726 | @end smallexample | |
727 | ||
728 | @noindent | |
729 | @code{lquote} and @code{rquote} are indeed the new left and right quotes. | |
730 | To look at some context, we can display ten lines of source | |
731 | surrounding the current line with the @code{l} (@code{list}) command. | |
732 | ||
733 | @smallexample | |
734 | (@value{GDBP}) @b{l} | |
735 | 533 xfree(rquote); | |
736 | 534 | |
737 | 535 lquote = (lq == nil || *lq == '\0') ? def_lquote\ | |
738 | : xstrdup (lq); | |
739 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
740 | : xstrdup (rq); | |
741 | 537 | |
742 | 538 len_lquote = strlen(rquote); | |
743 | 539 len_rquote = strlen(lquote); | |
744 | 540 @} | |
745 | 541 | |
746 | 542 void | |
747 | @end smallexample | |
748 | ||
749 | @noindent | |
750 | Let us step past the two lines that set @code{len_lquote} and | |
751 | @code{len_rquote}, and then examine the values of those variables. | |
752 | ||
753 | @smallexample | |
754 | (@value{GDBP}) @b{n} | |
755 | 539 len_rquote = strlen(lquote); | |
756 | (@value{GDBP}) @b{n} | |
757 | 540 @} | |
758 | (@value{GDBP}) @b{p len_lquote} | |
759 | $3 = 9 | |
760 | (@value{GDBP}) @b{p len_rquote} | |
761 | $4 = 7 | |
762 | @end smallexample | |
763 | ||
764 | @noindent | |
765 | That certainly looks wrong, assuming @code{len_lquote} and | |
766 | @code{len_rquote} are meant to be the lengths of @code{lquote} and | |
767 | @code{rquote} respectively. We can set them to better values using | |
768 | the @code{p} command, since it can print the value of | |
769 | any expression---and that expression can include subroutine calls and | |
770 | assignments. | |
771 | ||
772 | @smallexample | |
773 | (@value{GDBP}) @b{p len_lquote=strlen(lquote)} | |
774 | $5 = 7 | |
775 | (@value{GDBP}) @b{p len_rquote=strlen(rquote)} | |
776 | $6 = 9 | |
777 | @end smallexample | |
778 | ||
779 | @noindent | |
780 | Is that enough to fix the problem of using the new quotes with the | |
781 | @code{m4} built-in @code{defn}? We can allow @code{m4} to continue | |
782 | executing with the @code{c} (@code{continue}) command, and then try the | |
783 | example that caused trouble initially: | |
784 | ||
785 | @smallexample | |
786 | (@value{GDBP}) @b{c} | |
787 | Continuing. | |
788 | ||
789 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
790 | ||
791 | baz | |
792 | 0000 | |
793 | @end smallexample | |
794 | ||
795 | @noindent | |
796 | Success! The new quotes now work just as well as the default ones. The | |
797 | problem seems to have been just the two typos defining the wrong | |
798 | lengths. We allow @code{m4} exit by giving it an EOF as input: | |
799 | ||
800 | @smallexample | |
c8aa23ab | 801 | @b{Ctrl-d} |
c906108c SS |
802 | Program exited normally. |
803 | @end smallexample | |
804 | ||
805 | @noindent | |
806 | The message @samp{Program exited normally.} is from @value{GDBN}; it | |
807 | indicates @code{m4} has finished executing. We can end our @value{GDBN} | |
808 | session with the @value{GDBN} @code{quit} command. | |
809 | ||
810 | @smallexample | |
811 | (@value{GDBP}) @b{quit} | |
812 | @end smallexample | |
c906108c | 813 | |
6d2ebf8b | 814 | @node Invocation |
c906108c SS |
815 | @chapter Getting In and Out of @value{GDBN} |
816 | ||
817 | This chapter discusses how to start @value{GDBN}, and how to get out of it. | |
5d161b24 | 818 | The essentials are: |
c906108c | 819 | @itemize @bullet |
5d161b24 | 820 | @item |
53a5351d | 821 | type @samp{@value{GDBP}} to start @value{GDBN}. |
5d161b24 | 822 | @item |
c8aa23ab | 823 | type @kbd{quit} or @kbd{Ctrl-d} to exit. |
c906108c SS |
824 | @end itemize |
825 | ||
826 | @menu | |
827 | * Invoking GDB:: How to start @value{GDBN} | |
828 | * Quitting GDB:: How to quit @value{GDBN} | |
829 | * Shell Commands:: How to use shell commands inside @value{GDBN} | |
79a6e687 | 830 | * Logging Output:: How to log @value{GDBN}'s output to a file |
c906108c SS |
831 | @end menu |
832 | ||
6d2ebf8b | 833 | @node Invoking GDB |
c906108c SS |
834 | @section Invoking @value{GDBN} |
835 | ||
c906108c SS |
836 | Invoke @value{GDBN} by running the program @code{@value{GDBP}}. Once started, |
837 | @value{GDBN} reads commands from the terminal until you tell it to exit. | |
838 | ||
839 | You can also run @code{@value{GDBP}} with a variety of arguments and options, | |
840 | to specify more of your debugging environment at the outset. | |
841 | ||
c906108c SS |
842 | The command-line options described here are designed |
843 | to cover a variety of situations; in some environments, some of these | |
5d161b24 | 844 | options may effectively be unavailable. |
c906108c SS |
845 | |
846 | The most usual way to start @value{GDBN} is with one argument, | |
847 | specifying an executable program: | |
848 | ||
474c8240 | 849 | @smallexample |
c906108c | 850 | @value{GDBP} @var{program} |
474c8240 | 851 | @end smallexample |
c906108c | 852 | |
c906108c SS |
853 | @noindent |
854 | You can also start with both an executable program and a core file | |
855 | specified: | |
856 | ||
474c8240 | 857 | @smallexample |
c906108c | 858 | @value{GDBP} @var{program} @var{core} |
474c8240 | 859 | @end smallexample |
c906108c SS |
860 | |
861 | You can, instead, specify a process ID as a second argument, if you want | |
862 | to debug a running process: | |
863 | ||
474c8240 | 864 | @smallexample |
c906108c | 865 | @value{GDBP} @var{program} 1234 |
474c8240 | 866 | @end smallexample |
c906108c SS |
867 | |
868 | @noindent | |
869 | would attach @value{GDBN} to process @code{1234} (unless you also have a file | |
870 | named @file{1234}; @value{GDBN} does check for a core file first). | |
871 | ||
c906108c | 872 | Taking advantage of the second command-line argument requires a fairly |
2df3850c JM |
873 | complete operating system; when you use @value{GDBN} as a remote |
874 | debugger attached to a bare board, there may not be any notion of | |
875 | ``process'', and there is often no way to get a core dump. @value{GDBN} | |
876 | will warn you if it is unable to attach or to read core dumps. | |
c906108c | 877 | |
aa26fa3a TT |
878 | You can optionally have @code{@value{GDBP}} pass any arguments after the |
879 | executable file to the inferior using @code{--args}. This option stops | |
880 | option processing. | |
474c8240 | 881 | @smallexample |
3f94c067 | 882 | @value{GDBP} --args gcc -O2 -c foo.c |
474c8240 | 883 | @end smallexample |
aa26fa3a TT |
884 | This will cause @code{@value{GDBP}} to debug @code{gcc}, and to set |
885 | @code{gcc}'s command-line arguments (@pxref{Arguments}) to @samp{-O2 -c foo.c}. | |
886 | ||
96a2c332 | 887 | You can run @code{@value{GDBP}} without printing the front material, which describes |
adcc0a31 | 888 | @value{GDBN}'s non-warranty, by specifying @code{--silent} |
889 | (or @code{-q}/@code{--quiet}): | |
c906108c SS |
890 | |
891 | @smallexample | |
adcc0a31 | 892 | @value{GDBP} --silent |
c906108c SS |
893 | @end smallexample |
894 | ||
895 | @noindent | |
896 | You can further control how @value{GDBN} starts up by using command-line | |
897 | options. @value{GDBN} itself can remind you of the options available. | |
898 | ||
899 | @noindent | |
900 | Type | |
901 | ||
474c8240 | 902 | @smallexample |
c906108c | 903 | @value{GDBP} -help |
474c8240 | 904 | @end smallexample |
c906108c SS |
905 | |
906 | @noindent | |
907 | to display all available options and briefly describe their use | |
908 | (@samp{@value{GDBP} -h} is a shorter equivalent). | |
909 | ||
910 | All options and command line arguments you give are processed | |
911 | in sequential order. The order makes a difference when the | |
912 | @samp{-x} option is used. | |
913 | ||
914 | ||
915 | @menu | |
c906108c SS |
916 | * File Options:: Choosing files |
917 | * Mode Options:: Choosing modes | |
6fc08d32 | 918 | * Startup:: What @value{GDBN} does during startup |
c906108c SS |
919 | @end menu |
920 | ||
6d2ebf8b | 921 | @node File Options |
79a6e687 | 922 | @subsection Choosing Files |
c906108c | 923 | |
2df3850c | 924 | When @value{GDBN} starts, it reads any arguments other than options as |
c906108c SS |
925 | specifying an executable file and core file (or process ID). This is |
926 | the same as if the arguments were specified by the @samp{-se} and | |
d52fb0e9 | 927 | @samp{-c} (or @samp{-p}) options respectively. (@value{GDBN} reads the |
19837790 MS |
928 | first argument that does not have an associated option flag as |
929 | equivalent to the @samp{-se} option followed by that argument; and the | |
930 | second argument that does not have an associated option flag, if any, as | |
931 | equivalent to the @samp{-c}/@samp{-p} option followed by that argument.) | |
932 | If the second argument begins with a decimal digit, @value{GDBN} will | |
933 | first attempt to attach to it as a process, and if that fails, attempt | |
934 | to open it as a corefile. If you have a corefile whose name begins with | |
b383017d | 935 | a digit, you can prevent @value{GDBN} from treating it as a pid by |
c1468174 | 936 | prefixing it with @file{./}, e.g.@: @file{./12345}. |
7a292a7a SS |
937 | |
938 | If @value{GDBN} has not been configured to included core file support, | |
939 | such as for most embedded targets, then it will complain about a second | |
940 | argument and ignore it. | |
c906108c SS |
941 | |
942 | Many options have both long and short forms; both are shown in the | |
943 | following list. @value{GDBN} also recognizes the long forms if you truncate | |
944 | them, so long as enough of the option is present to be unambiguous. | |
945 | (If you prefer, you can flag option arguments with @samp{--} rather | |
946 | than @samp{-}, though we illustrate the more usual convention.) | |
947 | ||
d700128c EZ |
948 | @c NOTE: the @cindex entries here use double dashes ON PURPOSE. This |
949 | @c way, both those who look for -foo and --foo in the index, will find | |
950 | @c it. | |
951 | ||
c906108c SS |
952 | @table @code |
953 | @item -symbols @var{file} | |
954 | @itemx -s @var{file} | |
d700128c EZ |
955 | @cindex @code{--symbols} |
956 | @cindex @code{-s} | |
c906108c SS |
957 | Read symbol table from file @var{file}. |
958 | ||
959 | @item -exec @var{file} | |
960 | @itemx -e @var{file} | |
d700128c EZ |
961 | @cindex @code{--exec} |
962 | @cindex @code{-e} | |
7a292a7a SS |
963 | Use file @var{file} as the executable file to execute when appropriate, |
964 | and for examining pure data in conjunction with a core dump. | |
c906108c SS |
965 | |
966 | @item -se @var{file} | |
d700128c | 967 | @cindex @code{--se} |
c906108c SS |
968 | Read symbol table from file @var{file} and use it as the executable |
969 | file. | |
970 | ||
c906108c SS |
971 | @item -core @var{file} |
972 | @itemx -c @var{file} | |
d700128c EZ |
973 | @cindex @code{--core} |
974 | @cindex @code{-c} | |
b383017d | 975 | Use file @var{file} as a core dump to examine. |
c906108c | 976 | |
19837790 MS |
977 | @item -pid @var{number} |
978 | @itemx -p @var{number} | |
979 | @cindex @code{--pid} | |
980 | @cindex @code{-p} | |
981 | Connect to process ID @var{number}, as with the @code{attach} command. | |
c906108c SS |
982 | |
983 | @item -command @var{file} | |
984 | @itemx -x @var{file} | |
d700128c EZ |
985 | @cindex @code{--command} |
986 | @cindex @code{-x} | |
95433b34 JB |
987 | Execute commands from file @var{file}. The contents of this file is |
988 | evaluated exactly as the @code{source} command would. | |
8150ff9c | 989 | @xref{Command Files,, Command files}. |
c906108c | 990 | |
8a5a3c82 AS |
991 | @item -eval-command @var{command} |
992 | @itemx -ex @var{command} | |
993 | @cindex @code{--eval-command} | |
994 | @cindex @code{-ex} | |
995 | Execute a single @value{GDBN} command. | |
996 | ||
997 | This option may be used multiple times to call multiple commands. It may | |
998 | also be interleaved with @samp{-command} as required. | |
999 | ||
1000 | @smallexample | |
1001 | @value{GDBP} -ex 'target sim' -ex 'load' \ | |
1002 | -x setbreakpoints -ex 'run' a.out | |
1003 | @end smallexample | |
1004 | ||
8320cc4f JK |
1005 | @item -init-command @var{file} |
1006 | @itemx -ix @var{file} | |
1007 | @cindex @code{--init-command} | |
1008 | @cindex @code{-ix} | |
2d7b58e8 JK |
1009 | Execute commands from file @var{file} before loading the inferior (but |
1010 | after loading gdbinit files). | |
8320cc4f JK |
1011 | @xref{Startup}. |
1012 | ||
1013 | @item -init-eval-command @var{command} | |
1014 | @itemx -iex @var{command} | |
1015 | @cindex @code{--init-eval-command} | |
1016 | @cindex @code{-iex} | |
2d7b58e8 JK |
1017 | Execute a single @value{GDBN} command before loading the inferior (but |
1018 | after loading gdbinit files). | |
8320cc4f JK |
1019 | @xref{Startup}. |
1020 | ||
c906108c SS |
1021 | @item -directory @var{directory} |
1022 | @itemx -d @var{directory} | |
d700128c EZ |
1023 | @cindex @code{--directory} |
1024 | @cindex @code{-d} | |
4b505b12 | 1025 | Add @var{directory} to the path to search for source and script files. |
c906108c | 1026 | |
c906108c SS |
1027 | @item -r |
1028 | @itemx -readnow | |
d700128c EZ |
1029 | @cindex @code{--readnow} |
1030 | @cindex @code{-r} | |
c906108c SS |
1031 | Read each symbol file's entire symbol table immediately, rather than |
1032 | the default, which is to read it incrementally as it is needed. | |
1033 | This makes startup slower, but makes future operations faster. | |
53a5351d | 1034 | |
c906108c SS |
1035 | @end table |
1036 | ||
6d2ebf8b | 1037 | @node Mode Options |
79a6e687 | 1038 | @subsection Choosing Modes |
c906108c SS |
1039 | |
1040 | You can run @value{GDBN} in various alternative modes---for example, in | |
1041 | batch mode or quiet mode. | |
1042 | ||
1043 | @table @code | |
bf88dd68 | 1044 | @anchor{-nx} |
c906108c SS |
1045 | @item -nx |
1046 | @itemx -n | |
d700128c EZ |
1047 | @cindex @code{--nx} |
1048 | @cindex @code{-n} | |
07540c15 DE |
1049 | Do not execute commands found in any initialization file. |
1050 | There are three init files, loaded in the following order: | |
1051 | ||
1052 | @table @code | |
1053 | @item @file{system.gdbinit} | |
1054 | This is the system-wide init file. | |
1055 | Its location is specified with the @code{--with-system-gdbinit} | |
1056 | configure option (@pxref{System-wide configuration}). | |
1057 | It is loaded first when @value{GDBN} starts, before command line options | |
1058 | have been processed. | |
1059 | @item @file{~/.gdbinit} | |
1060 | This is the init file in your home directory. | |
1061 | It is loaded next, after @file{system.gdbinit}, and before | |
1062 | command options have been processed. | |
1063 | @item @file{./.gdbinit} | |
1064 | This is the init file in the current directory. | |
1065 | It is loaded last, after command line options other than @code{-x} and | |
1066 | @code{-ex} have been processed. Command line options @code{-x} and | |
1067 | @code{-ex} are processed last, after @file{./.gdbinit} has been loaded. | |
1068 | @end table | |
1069 | ||
1070 | For further documentation on startup processing, @xref{Startup}. | |
1071 | For documentation on how to write command files, | |
1072 | @xref{Command Files,,Command Files}. | |
1073 | ||
1074 | @anchor{-nh} | |
1075 | @item -nh | |
1076 | @cindex @code{--nh} | |
1077 | Do not execute commands found in @file{~/.gdbinit}, the init file | |
1078 | in your home directory. | |
1079 | @xref{Startup}. | |
c906108c SS |
1080 | |
1081 | @item -quiet | |
d700128c | 1082 | @itemx -silent |
c906108c | 1083 | @itemx -q |
d700128c EZ |
1084 | @cindex @code{--quiet} |
1085 | @cindex @code{--silent} | |
1086 | @cindex @code{-q} | |
c906108c SS |
1087 | ``Quiet''. Do not print the introductory and copyright messages. These |
1088 | messages are also suppressed in batch mode. | |
1089 | ||
1090 | @item -batch | |
d700128c | 1091 | @cindex @code{--batch} |
c906108c SS |
1092 | Run in batch mode. Exit with status @code{0} after processing all the |
1093 | command files specified with @samp{-x} (and all commands from | |
1094 | initialization files, if not inhibited with @samp{-n}). Exit with | |
1095 | nonzero status if an error occurs in executing the @value{GDBN} commands | |
5da1313b JK |
1096 | in the command files. Batch mode also disables pagination, sets unlimited |
1097 | terminal width and height @pxref{Screen Size}, and acts as if @kbd{set confirm | |
1098 | off} were in effect (@pxref{Messages/Warnings}). | |
c906108c | 1099 | |
2df3850c JM |
1100 | Batch mode may be useful for running @value{GDBN} as a filter, for |
1101 | example to download and run a program on another computer; in order to | |
1102 | make this more useful, the message | |
c906108c | 1103 | |
474c8240 | 1104 | @smallexample |
c906108c | 1105 | Program exited normally. |
474c8240 | 1106 | @end smallexample |
c906108c SS |
1107 | |
1108 | @noindent | |
2df3850c JM |
1109 | (which is ordinarily issued whenever a program running under |
1110 | @value{GDBN} control terminates) is not issued when running in batch | |
1111 | mode. | |
1112 | ||
1a088d06 AS |
1113 | @item -batch-silent |
1114 | @cindex @code{--batch-silent} | |
1115 | Run in batch mode exactly like @samp{-batch}, but totally silently. All | |
1116 | @value{GDBN} output to @code{stdout} is prevented (@code{stderr} is | |
1117 | unaffected). This is much quieter than @samp{-silent} and would be useless | |
1118 | for an interactive session. | |
1119 | ||
1120 | This is particularly useful when using targets that give @samp{Loading section} | |
1121 | messages, for example. | |
1122 | ||
1123 | Note that targets that give their output via @value{GDBN}, as opposed to | |
1124 | writing directly to @code{stdout}, will also be made silent. | |
1125 | ||
4b0ad762 AS |
1126 | @item -return-child-result |
1127 | @cindex @code{--return-child-result} | |
1128 | The return code from @value{GDBN} will be the return code from the child | |
1129 | process (the process being debugged), with the following exceptions: | |
1130 | ||
1131 | @itemize @bullet | |
1132 | @item | |
1133 | @value{GDBN} exits abnormally. E.g., due to an incorrect argument or an | |
1134 | internal error. In this case the exit code is the same as it would have been | |
1135 | without @samp{-return-child-result}. | |
1136 | @item | |
1137 | The user quits with an explicit value. E.g., @samp{quit 1}. | |
1138 | @item | |
1139 | The child process never runs, or is not allowed to terminate, in which case | |
1140 | the exit code will be -1. | |
1141 | @end itemize | |
1142 | ||
1143 | This option is useful in conjunction with @samp{-batch} or @samp{-batch-silent}, | |
1144 | when @value{GDBN} is being used as a remote program loader or simulator | |
1145 | interface. | |
1146 | ||
2df3850c JM |
1147 | @item -nowindows |
1148 | @itemx -nw | |
d700128c EZ |
1149 | @cindex @code{--nowindows} |
1150 | @cindex @code{-nw} | |
2df3850c | 1151 | ``No windows''. If @value{GDBN} comes with a graphical user interface |
96a2c332 | 1152 | (GUI) built in, then this option tells @value{GDBN} to only use the command-line |
2df3850c JM |
1153 | interface. If no GUI is available, this option has no effect. |
1154 | ||
1155 | @item -windows | |
1156 | @itemx -w | |
d700128c EZ |
1157 | @cindex @code{--windows} |
1158 | @cindex @code{-w} | |
2df3850c JM |
1159 | If @value{GDBN} includes a GUI, then this option requires it to be |
1160 | used if possible. | |
c906108c SS |
1161 | |
1162 | @item -cd @var{directory} | |
d700128c | 1163 | @cindex @code{--cd} |
c906108c SS |
1164 | Run @value{GDBN} using @var{directory} as its working directory, |
1165 | instead of the current directory. | |
1166 | ||
aae1c79a | 1167 | @item -data-directory @var{directory} |
8d551b02 | 1168 | @itemx -D @var{directory} |
aae1c79a | 1169 | @cindex @code{--data-directory} |
8d551b02 | 1170 | @cindex @code{-D} |
aae1c79a DE |
1171 | Run @value{GDBN} using @var{directory} as its data directory. |
1172 | The data directory is where @value{GDBN} searches for its | |
1173 | auxiliary files. @xref{Data Files}. | |
1174 | ||
c906108c SS |
1175 | @item -fullname |
1176 | @itemx -f | |
d700128c EZ |
1177 | @cindex @code{--fullname} |
1178 | @cindex @code{-f} | |
7a292a7a SS |
1179 | @sc{gnu} Emacs sets this option when it runs @value{GDBN} as a |
1180 | subprocess. It tells @value{GDBN} to output the full file name and line | |
1181 | number in a standard, recognizable fashion each time a stack frame is | |
1182 | displayed (which includes each time your program stops). This | |
1183 | recognizable format looks like two @samp{\032} characters, followed by | |
1184 | the file name, line number and character position separated by colons, | |
1185 | and a newline. The Emacs-to-@value{GDBN} interface program uses the two | |
1186 | @samp{\032} characters as a signal to display the source code for the | |
1187 | frame. | |
c906108c | 1188 | |
d700128c EZ |
1189 | @item -annotate @var{level} |
1190 | @cindex @code{--annotate} | |
1191 | This option sets the @dfn{annotation level} inside @value{GDBN}. Its | |
1192 | effect is identical to using @samp{set annotate @var{level}} | |
086432e2 AC |
1193 | (@pxref{Annotations}). The annotation @var{level} controls how much |
1194 | information @value{GDBN} prints together with its prompt, values of | |
1195 | expressions, source lines, and other types of output. Level 0 is the | |
1196 | normal, level 1 is for use when @value{GDBN} is run as a subprocess of | |
1197 | @sc{gnu} Emacs, level 3 is the maximum annotation suitable for programs | |
1198 | that control @value{GDBN}, and level 2 has been deprecated. | |
1199 | ||
265eeb58 | 1200 | The annotation mechanism has largely been superseded by @sc{gdb/mi} |
086432e2 | 1201 | (@pxref{GDB/MI}). |
d700128c | 1202 | |
aa26fa3a TT |
1203 | @item --args |
1204 | @cindex @code{--args} | |
1205 | Change interpretation of command line so that arguments following the | |
1206 | executable file are passed as command line arguments to the inferior. | |
1207 | This option stops option processing. | |
1208 | ||
2df3850c JM |
1209 | @item -baud @var{bps} |
1210 | @itemx -b @var{bps} | |
d700128c EZ |
1211 | @cindex @code{--baud} |
1212 | @cindex @code{-b} | |
c906108c SS |
1213 | Set the line speed (baud rate or bits per second) of any serial |
1214 | interface used by @value{GDBN} for remote debugging. | |
c906108c | 1215 | |
f47b1503 AS |
1216 | @item -l @var{timeout} |
1217 | @cindex @code{-l} | |
1218 | Set the timeout (in seconds) of any communication used by @value{GDBN} | |
1219 | for remote debugging. | |
1220 | ||
c906108c | 1221 | @item -tty @var{device} |
d700128c EZ |
1222 | @itemx -t @var{device} |
1223 | @cindex @code{--tty} | |
1224 | @cindex @code{-t} | |
c906108c SS |
1225 | Run using @var{device} for your program's standard input and output. |
1226 | @c FIXME: kingdon thinks there is more to -tty. Investigate. | |
c906108c | 1227 | |
53a5351d | 1228 | @c resolve the situation of these eventually |
c4555f82 SC |
1229 | @item -tui |
1230 | @cindex @code{--tui} | |
d0d5df6f AC |
1231 | Activate the @dfn{Text User Interface} when starting. The Text User |
1232 | Interface manages several text windows on the terminal, showing | |
1233 | source, assembly, registers and @value{GDBN} command outputs | |
217bff3e JK |
1234 | (@pxref{TUI, ,@value{GDBN} Text User Interface}). Do not use this |
1235 | option if you run @value{GDBN} from Emacs (@pxref{Emacs, , | |
1236 | Using @value{GDBN} under @sc{gnu} Emacs}). | |
53a5351d JM |
1237 | |
1238 | @c @item -xdb | |
d700128c | 1239 | @c @cindex @code{--xdb} |
53a5351d JM |
1240 | @c Run in XDB compatibility mode, allowing the use of certain XDB commands. |
1241 | @c For information, see the file @file{xdb_trans.html}, which is usually | |
1242 | @c installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX | |
1243 | @c systems. | |
1244 | ||
d700128c EZ |
1245 | @item -interpreter @var{interp} |
1246 | @cindex @code{--interpreter} | |
1247 | Use the interpreter @var{interp} for interface with the controlling | |
1248 | program or device. This option is meant to be set by programs which | |
94bbb2c0 | 1249 | communicate with @value{GDBN} using it as a back end. |
21c294e6 | 1250 | @xref{Interpreters, , Command Interpreters}. |
94bbb2c0 | 1251 | |
da0f9dcd | 1252 | @samp{--interpreter=mi} (or @samp{--interpreter=mi2}) causes |
2fcf52f0 | 1253 | @value{GDBN} to use the @dfn{@sc{gdb/mi} interface} (@pxref{GDB/MI, , |
6b5e8c01 | 1254 | The @sc{gdb/mi} Interface}) included since @value{GDBN} version 6.0. The |
6c74ac8b AC |
1255 | previous @sc{gdb/mi} interface, included in @value{GDBN} version 5.3 and |
1256 | selected with @samp{--interpreter=mi1}, is deprecated. Earlier | |
1257 | @sc{gdb/mi} interfaces are no longer supported. | |
d700128c EZ |
1258 | |
1259 | @item -write | |
1260 | @cindex @code{--write} | |
1261 | Open the executable and core files for both reading and writing. This | |
1262 | is equivalent to the @samp{set write on} command inside @value{GDBN} | |
1263 | (@pxref{Patching}). | |
1264 | ||
1265 | @item -statistics | |
1266 | @cindex @code{--statistics} | |
1267 | This option causes @value{GDBN} to print statistics about time and | |
1268 | memory usage after it completes each command and returns to the prompt. | |
1269 | ||
1270 | @item -version | |
1271 | @cindex @code{--version} | |
1272 | This option causes @value{GDBN} to print its version number and | |
1273 | no-warranty blurb, and exit. | |
1274 | ||
6eaaf48b EZ |
1275 | @item -configuration |
1276 | @cindex @code{--configuration} | |
1277 | This option causes @value{GDBN} to print details about its build-time | |
1278 | configuration parameters, and then exit. These details can be | |
1279 | important when reporting @value{GDBN} bugs (@pxref{GDB Bugs}). | |
1280 | ||
c906108c SS |
1281 | @end table |
1282 | ||
6fc08d32 | 1283 | @node Startup |
79a6e687 | 1284 | @subsection What @value{GDBN} Does During Startup |
6fc08d32 EZ |
1285 | @cindex @value{GDBN} startup |
1286 | ||
1287 | Here's the description of what @value{GDBN} does during session startup: | |
1288 | ||
1289 | @enumerate | |
1290 | @item | |
1291 | Sets up the command interpreter as specified by the command line | |
1292 | (@pxref{Mode Options, interpreter}). | |
1293 | ||
1294 | @item | |
1295 | @cindex init file | |
098b41a6 JG |
1296 | Reads the system-wide @dfn{init file} (if @option{--with-system-gdbinit} was |
1297 | used when building @value{GDBN}; @pxref{System-wide configuration, | |
1298 | ,System-wide configuration and settings}) and executes all the commands in | |
1299 | that file. | |
1300 | ||
bf88dd68 | 1301 | @anchor{Home Directory Init File} |
098b41a6 JG |
1302 | @item |
1303 | Reads the init file (if any) in your home directory@footnote{On | |
6fc08d32 EZ |
1304 | DOS/Windows systems, the home directory is the one pointed to by the |
1305 | @code{HOME} environment variable.} and executes all the commands in | |
1306 | that file. | |
1307 | ||
2d7b58e8 JK |
1308 | @anchor{Option -init-eval-command} |
1309 | @item | |
1310 | Executes commands and command files specified by the @samp{-iex} and | |
1311 | @samp{-ix} options in their specified order. Usually you should use the | |
1312 | @samp{-ex} and @samp{-x} options instead, but this way you can apply | |
1313 | settings before @value{GDBN} init files get executed and before inferior | |
1314 | gets loaded. | |
1315 | ||
6fc08d32 EZ |
1316 | @item |
1317 | Processes command line options and operands. | |
1318 | ||
bf88dd68 | 1319 | @anchor{Init File in the Current Directory during Startup} |
6fc08d32 EZ |
1320 | @item |
1321 | Reads and executes the commands from init file (if any) in the current | |
bf88dd68 JK |
1322 | working directory as long as @samp{set auto-load local-gdbinit} is set to |
1323 | @samp{on} (@pxref{Init File in the Current Directory}). | |
1324 | This is only done if the current directory is | |
119b882a EZ |
1325 | different from your home directory. Thus, you can have more than one |
1326 | init file, one generic in your home directory, and another, specific | |
1327 | to the program you are debugging, in the directory where you invoke | |
6fc08d32 EZ |
1328 | @value{GDBN}. |
1329 | ||
a86caf66 DE |
1330 | @item |
1331 | If the command line specified a program to debug, or a process to | |
1332 | attach to, or a core file, @value{GDBN} loads any auto-loaded | |
1333 | scripts provided for the program or for its loaded shared libraries. | |
1334 | @xref{Auto-loading}. | |
1335 | ||
1336 | If you wish to disable the auto-loading during startup, | |
1337 | you must do something like the following: | |
1338 | ||
1339 | @smallexample | |
bf88dd68 | 1340 | $ gdb -iex "set auto-load python-scripts off" myprogram |
a86caf66 DE |
1341 | @end smallexample |
1342 | ||
8320cc4f JK |
1343 | Option @samp{-ex} does not work because the auto-loading is then turned |
1344 | off too late. | |
a86caf66 | 1345 | |
6fc08d32 | 1346 | @item |
6fe37d23 JK |
1347 | Executes commands and command files specified by the @samp{-ex} and |
1348 | @samp{-x} options in their specified order. @xref{Command Files}, for | |
1349 | more details about @value{GDBN} command files. | |
6fc08d32 EZ |
1350 | |
1351 | @item | |
1352 | Reads the command history recorded in the @dfn{history file}. | |
d620b259 | 1353 | @xref{Command History}, for more details about the command history and the |
6fc08d32 EZ |
1354 | files where @value{GDBN} records it. |
1355 | @end enumerate | |
1356 | ||
1357 | Init files use the same syntax as @dfn{command files} (@pxref{Command | |
1358 | Files}) and are processed by @value{GDBN} in the same way. The init | |
1359 | file in your home directory can set options (such as @samp{set | |
1360 | complaints}) that affect subsequent processing of command line options | |
1361 | and operands. Init files are not executed if you use the @samp{-nx} | |
79a6e687 | 1362 | option (@pxref{Mode Options, ,Choosing Modes}). |
6fc08d32 | 1363 | |
098b41a6 JG |
1364 | To display the list of init files loaded by gdb at startup, you |
1365 | can use @kbd{gdb --help}. | |
1366 | ||
6fc08d32 EZ |
1367 | @cindex init file name |
1368 | @cindex @file{.gdbinit} | |
119b882a | 1369 | @cindex @file{gdb.ini} |
8807d78b | 1370 | The @value{GDBN} init files are normally called @file{.gdbinit}. |
119b882a EZ |
1371 | The DJGPP port of @value{GDBN} uses the name @file{gdb.ini}, due to |
1372 | the limitations of file names imposed by DOS filesystems. The Windows | |
4d3f93a2 JB |
1373 | port of @value{GDBN} uses the standard name, but if it finds a |
1374 | @file{gdb.ini} file in your home directory, it warns you about that | |
1375 | and suggests to rename the file to the standard name. | |
119b882a | 1376 | |
6fc08d32 | 1377 | |
6d2ebf8b | 1378 | @node Quitting GDB |
c906108c SS |
1379 | @section Quitting @value{GDBN} |
1380 | @cindex exiting @value{GDBN} | |
1381 | @cindex leaving @value{GDBN} | |
1382 | ||
1383 | @table @code | |
1384 | @kindex quit @r{[}@var{expression}@r{]} | |
41afff9a | 1385 | @kindex q @r{(@code{quit})} |
96a2c332 SS |
1386 | @item quit @r{[}@var{expression}@r{]} |
1387 | @itemx q | |
1388 | To exit @value{GDBN}, use the @code{quit} command (abbreviated | |
c8aa23ab | 1389 | @code{q}), or type an end-of-file character (usually @kbd{Ctrl-d}). If you |
96a2c332 SS |
1390 | do not supply @var{expression}, @value{GDBN} will terminate normally; |
1391 | otherwise it will terminate using the result of @var{expression} as the | |
1392 | error code. | |
c906108c SS |
1393 | @end table |
1394 | ||
1395 | @cindex interrupt | |
c8aa23ab | 1396 | An interrupt (often @kbd{Ctrl-c}) does not exit from @value{GDBN}, but rather |
c906108c SS |
1397 | terminates the action of any @value{GDBN} command that is in progress and |
1398 | returns to @value{GDBN} command level. It is safe to type the interrupt | |
1399 | character at any time because @value{GDBN} does not allow it to take effect | |
1400 | until a time when it is safe. | |
1401 | ||
c906108c SS |
1402 | If you have been using @value{GDBN} to control an attached process or |
1403 | device, you can release it with the @code{detach} command | |
79a6e687 | 1404 | (@pxref{Attach, ,Debugging an Already-running Process}). |
c906108c | 1405 | |
6d2ebf8b | 1406 | @node Shell Commands |
79a6e687 | 1407 | @section Shell Commands |
c906108c SS |
1408 | |
1409 | If you need to execute occasional shell commands during your | |
1410 | debugging session, there is no need to leave or suspend @value{GDBN}; you can | |
1411 | just use the @code{shell} command. | |
1412 | ||
1413 | @table @code | |
1414 | @kindex shell | |
ed59ded5 | 1415 | @kindex ! |
c906108c | 1416 | @cindex shell escape |
ed59ded5 DE |
1417 | @item shell @var{command-string} |
1418 | @itemx !@var{command-string} | |
1419 | Invoke a standard shell to execute @var{command-string}. | |
1420 | Note that no space is needed between @code{!} and @var{command-string}. | |
c906108c | 1421 | If it exists, the environment variable @code{SHELL} determines which |
d4f3574e SS |
1422 | shell to run. Otherwise @value{GDBN} uses the default shell |
1423 | (@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.). | |
c906108c SS |
1424 | @end table |
1425 | ||
1426 | The utility @code{make} is often needed in development environments. | |
1427 | You do not have to use the @code{shell} command for this purpose in | |
1428 | @value{GDBN}: | |
1429 | ||
1430 | @table @code | |
1431 | @kindex make | |
1432 | @cindex calling make | |
1433 | @item make @var{make-args} | |
1434 | Execute the @code{make} program with the specified | |
1435 | arguments. This is equivalent to @samp{shell make @var{make-args}}. | |
1436 | @end table | |
1437 | ||
79a6e687 BW |
1438 | @node Logging Output |
1439 | @section Logging Output | |
0fac0b41 | 1440 | @cindex logging @value{GDBN} output |
9c16f35a | 1441 | @cindex save @value{GDBN} output to a file |
0fac0b41 DJ |
1442 | |
1443 | You may want to save the output of @value{GDBN} commands to a file. | |
1444 | There are several commands to control @value{GDBN}'s logging. | |
1445 | ||
1446 | @table @code | |
1447 | @kindex set logging | |
1448 | @item set logging on | |
1449 | Enable logging. | |
1450 | @item set logging off | |
1451 | Disable logging. | |
9c16f35a | 1452 | @cindex logging file name |
0fac0b41 DJ |
1453 | @item set logging file @var{file} |
1454 | Change the name of the current logfile. The default logfile is @file{gdb.txt}. | |
1455 | @item set logging overwrite [on|off] | |
1456 | By default, @value{GDBN} will append to the logfile. Set @code{overwrite} if | |
1457 | you want @code{set logging on} to overwrite the logfile instead. | |
1458 | @item set logging redirect [on|off] | |
1459 | By default, @value{GDBN} output will go to both the terminal and the logfile. | |
1460 | Set @code{redirect} if you want output to go only to the log file. | |
1461 | @kindex show logging | |
1462 | @item show logging | |
1463 | Show the current values of the logging settings. | |
1464 | @end table | |
1465 | ||
6d2ebf8b | 1466 | @node Commands |
c906108c SS |
1467 | @chapter @value{GDBN} Commands |
1468 | ||
1469 | You can abbreviate a @value{GDBN} command to the first few letters of the command | |
1470 | name, if that abbreviation is unambiguous; and you can repeat certain | |
1471 | @value{GDBN} commands by typing just @key{RET}. You can also use the @key{TAB} | |
1472 | key to get @value{GDBN} to fill out the rest of a word in a command (or to | |
1473 | show you the alternatives available, if there is more than one possibility). | |
1474 | ||
1475 | @menu | |
1476 | * Command Syntax:: How to give commands to @value{GDBN} | |
1477 | * Completion:: Command completion | |
1478 | * Help:: How to ask @value{GDBN} for help | |
1479 | @end menu | |
1480 | ||
6d2ebf8b | 1481 | @node Command Syntax |
79a6e687 | 1482 | @section Command Syntax |
c906108c SS |
1483 | |
1484 | A @value{GDBN} command is a single line of input. There is no limit on | |
1485 | how long it can be. It starts with a command name, which is followed by | |
1486 | arguments whose meaning depends on the command name. For example, the | |
1487 | command @code{step} accepts an argument which is the number of times to | |
1488 | step, as in @samp{step 5}. You can also use the @code{step} command | |
96a2c332 | 1489 | with no arguments. Some commands do not allow any arguments. |
c906108c SS |
1490 | |
1491 | @cindex abbreviation | |
1492 | @value{GDBN} command names may always be truncated if that abbreviation is | |
1493 | unambiguous. Other possible command abbreviations are listed in the | |
1494 | documentation for individual commands. In some cases, even ambiguous | |
1495 | abbreviations are allowed; for example, @code{s} is specially defined as | |
1496 | equivalent to @code{step} even though there are other commands whose | |
1497 | names start with @code{s}. You can test abbreviations by using them as | |
1498 | arguments to the @code{help} command. | |
1499 | ||
1500 | @cindex repeating commands | |
41afff9a | 1501 | @kindex RET @r{(repeat last command)} |
c906108c | 1502 | A blank line as input to @value{GDBN} (typing just @key{RET}) means to |
96a2c332 | 1503 | repeat the previous command. Certain commands (for example, @code{run}) |
c906108c SS |
1504 | will not repeat this way; these are commands whose unintentional |
1505 | repetition might cause trouble and which you are unlikely to want to | |
c45da7e6 EZ |
1506 | repeat. User-defined commands can disable this feature; see |
1507 | @ref{Define, dont-repeat}. | |
c906108c SS |
1508 | |
1509 | The @code{list} and @code{x} commands, when you repeat them with | |
1510 | @key{RET}, construct new arguments rather than repeating | |
1511 | exactly as typed. This permits easy scanning of source or memory. | |
1512 | ||
1513 | @value{GDBN} can also use @key{RET} in another way: to partition lengthy | |
1514 | output, in a way similar to the common utility @code{more} | |
79a6e687 | 1515 | (@pxref{Screen Size,,Screen Size}). Since it is easy to press one |
c906108c SS |
1516 | @key{RET} too many in this situation, @value{GDBN} disables command |
1517 | repetition after any command that generates this sort of display. | |
1518 | ||
41afff9a | 1519 | @kindex # @r{(a comment)} |
c906108c SS |
1520 | @cindex comment |
1521 | Any text from a @kbd{#} to the end of the line is a comment; it does | |
1522 | nothing. This is useful mainly in command files (@pxref{Command | |
79a6e687 | 1523 | Files,,Command Files}). |
c906108c | 1524 | |
88118b3a | 1525 | @cindex repeating command sequences |
c8aa23ab EZ |
1526 | @kindex Ctrl-o @r{(operate-and-get-next)} |
1527 | The @kbd{Ctrl-o} binding is useful for repeating a complex sequence of | |
7f9087cb | 1528 | commands. This command accepts the current line, like @key{RET}, and |
88118b3a TT |
1529 | then fetches the next line relative to the current line from the history |
1530 | for editing. | |
1531 | ||
6d2ebf8b | 1532 | @node Completion |
79a6e687 | 1533 | @section Command Completion |
c906108c SS |
1534 | |
1535 | @cindex completion | |
1536 | @cindex word completion | |
1537 | @value{GDBN} can fill in the rest of a word in a command for you, if there is | |
1538 | only one possibility; it can also show you what the valid possibilities | |
1539 | are for the next word in a command, at any time. This works for @value{GDBN} | |
1540 | commands, @value{GDBN} subcommands, and the names of symbols in your program. | |
1541 | ||
1542 | Press the @key{TAB} key whenever you want @value{GDBN} to fill out the rest | |
1543 | of a word. If there is only one possibility, @value{GDBN} fills in the | |
1544 | word, and waits for you to finish the command (or press @key{RET} to | |
1545 | enter it). For example, if you type | |
1546 | ||
1547 | @c FIXME "@key" does not distinguish its argument sufficiently to permit | |
1548 | @c complete accuracy in these examples; space introduced for clarity. | |
1549 | @c If texinfo enhancements make it unnecessary, it would be nice to | |
1550 | @c replace " @key" by "@key" in the following... | |
474c8240 | 1551 | @smallexample |
c906108c | 1552 | (@value{GDBP}) info bre @key{TAB} |
474c8240 | 1553 | @end smallexample |
c906108c SS |
1554 | |
1555 | @noindent | |
1556 | @value{GDBN} fills in the rest of the word @samp{breakpoints}, since that is | |
1557 | the only @code{info} subcommand beginning with @samp{bre}: | |
1558 | ||
474c8240 | 1559 | @smallexample |
c906108c | 1560 | (@value{GDBP}) info breakpoints |
474c8240 | 1561 | @end smallexample |
c906108c SS |
1562 | |
1563 | @noindent | |
1564 | You can either press @key{RET} at this point, to run the @code{info | |
1565 | breakpoints} command, or backspace and enter something else, if | |
1566 | @samp{breakpoints} does not look like the command you expected. (If you | |
1567 | were sure you wanted @code{info breakpoints} in the first place, you | |
1568 | might as well just type @key{RET} immediately after @samp{info bre}, | |
1569 | to exploit command abbreviations rather than command completion). | |
1570 | ||
1571 | If there is more than one possibility for the next word when you press | |
1572 | @key{TAB}, @value{GDBN} sounds a bell. You can either supply more | |
1573 | characters and try again, or just press @key{TAB} a second time; | |
1574 | @value{GDBN} displays all the possible completions for that word. For | |
1575 | example, you might want to set a breakpoint on a subroutine whose name | |
1576 | begins with @samp{make_}, but when you type @kbd{b make_@key{TAB}} @value{GDBN} | |
1577 | just sounds the bell. Typing @key{TAB} again displays all the | |
1578 | function names in your program that begin with those characters, for | |
1579 | example: | |
1580 | ||
474c8240 | 1581 | @smallexample |
c906108c SS |
1582 | (@value{GDBP}) b make_ @key{TAB} |
1583 | @exdent @value{GDBN} sounds bell; press @key{TAB} again, to see: | |
5d161b24 DB |
1584 | make_a_section_from_file make_environ |
1585 | make_abs_section make_function_type | |
1586 | make_blockvector make_pointer_type | |
1587 | make_cleanup make_reference_type | |
c906108c SS |
1588 | make_command make_symbol_completion_list |
1589 | (@value{GDBP}) b make_ | |
474c8240 | 1590 | @end smallexample |
c906108c SS |
1591 | |
1592 | @noindent | |
1593 | After displaying the available possibilities, @value{GDBN} copies your | |
1594 | partial input (@samp{b make_} in the example) so you can finish the | |
1595 | command. | |
1596 | ||
1597 | If you just want to see the list of alternatives in the first place, you | |
b37052ae | 1598 | can press @kbd{M-?} rather than pressing @key{TAB} twice. @kbd{M-?} |
7a292a7a | 1599 | means @kbd{@key{META} ?}. You can type this either by holding down a |
c906108c | 1600 | key designated as the @key{META} shift on your keyboard (if there is |
7a292a7a | 1601 | one) while typing @kbd{?}, or as @key{ESC} followed by @kbd{?}. |
c906108c SS |
1602 | |
1603 | @cindex quotes in commands | |
1604 | @cindex completion of quoted strings | |
1605 | Sometimes the string you need, while logically a ``word'', may contain | |
7a292a7a SS |
1606 | parentheses or other characters that @value{GDBN} normally excludes from |
1607 | its notion of a word. To permit word completion to work in this | |
1608 | situation, you may enclose words in @code{'} (single quote marks) in | |
1609 | @value{GDBN} commands. | |
c906108c | 1610 | |
c906108c | 1611 | The most likely situation where you might need this is in typing the |
b37052ae EZ |
1612 | name of a C@t{++} function. This is because C@t{++} allows function |
1613 | overloading (multiple definitions of the same function, distinguished | |
1614 | by argument type). For example, when you want to set a breakpoint you | |
1615 | may need to distinguish whether you mean the version of @code{name} | |
1616 | that takes an @code{int} parameter, @code{name(int)}, or the version | |
1617 | that takes a @code{float} parameter, @code{name(float)}. To use the | |
1618 | word-completion facilities in this situation, type a single quote | |
1619 | @code{'} at the beginning of the function name. This alerts | |
1620 | @value{GDBN} that it may need to consider more information than usual | |
1621 | when you press @key{TAB} or @kbd{M-?} to request word completion: | |
c906108c | 1622 | |
474c8240 | 1623 | @smallexample |
96a2c332 | 1624 | (@value{GDBP}) b 'bubble( @kbd{M-?} |
c906108c SS |
1625 | bubble(double,double) bubble(int,int) |
1626 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1627 | @end smallexample |
c906108c SS |
1628 | |
1629 | In some cases, @value{GDBN} can tell that completing a name requires using | |
1630 | quotes. When this happens, @value{GDBN} inserts the quote for you (while | |
1631 | completing as much as it can) if you do not type the quote in the first | |
1632 | place: | |
1633 | ||
474c8240 | 1634 | @smallexample |
c906108c SS |
1635 | (@value{GDBP}) b bub @key{TAB} |
1636 | @exdent @value{GDBN} alters your input line to the following, and rings a bell: | |
1637 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1638 | @end smallexample |
c906108c SS |
1639 | |
1640 | @noindent | |
1641 | In general, @value{GDBN} can tell that a quote is needed (and inserts it) if | |
1642 | you have not yet started typing the argument list when you ask for | |
1643 | completion on an overloaded symbol. | |
1644 | ||
79a6e687 BW |
1645 | For more information about overloaded functions, see @ref{C Plus Plus |
1646 | Expressions, ,C@t{++} Expressions}. You can use the command @code{set | |
c906108c | 1647 | overload-resolution off} to disable overload resolution; |
79a6e687 | 1648 | see @ref{Debugging C Plus Plus, ,@value{GDBN} Features for C@t{++}}. |
c906108c | 1649 | |
65d12d83 TT |
1650 | @cindex completion of structure field names |
1651 | @cindex structure field name completion | |
1652 | @cindex completion of union field names | |
1653 | @cindex union field name completion | |
1654 | When completing in an expression which looks up a field in a | |
1655 | structure, @value{GDBN} also tries@footnote{The completer can be | |
1656 | confused by certain kinds of invalid expressions. Also, it only | |
1657 | examines the static type of the expression, not the dynamic type.} to | |
1658 | limit completions to the field names available in the type of the | |
1659 | left-hand-side: | |
1660 | ||
1661 | @smallexample | |
1662 | (@value{GDBP}) p gdb_stdout.@kbd{M-?} | |
01124a23 DE |
1663 | magic to_fputs to_rewind |
1664 | to_data to_isatty to_write | |
1665 | to_delete to_put to_write_async_safe | |
1666 | to_flush to_read | |
65d12d83 TT |
1667 | @end smallexample |
1668 | ||
1669 | @noindent | |
1670 | This is because the @code{gdb_stdout} is a variable of the type | |
1671 | @code{struct ui_file} that is defined in @value{GDBN} sources as | |
1672 | follows: | |
1673 | ||
1674 | @smallexample | |
1675 | struct ui_file | |
1676 | @{ | |
1677 | int *magic; | |
1678 | ui_file_flush_ftype *to_flush; | |
1679 | ui_file_write_ftype *to_write; | |
01124a23 | 1680 | ui_file_write_async_safe_ftype *to_write_async_safe; |
65d12d83 TT |
1681 | ui_file_fputs_ftype *to_fputs; |
1682 | ui_file_read_ftype *to_read; | |
1683 | ui_file_delete_ftype *to_delete; | |
1684 | ui_file_isatty_ftype *to_isatty; | |
1685 | ui_file_rewind_ftype *to_rewind; | |
1686 | ui_file_put_ftype *to_put; | |
1687 | void *to_data; | |
1688 | @} | |
1689 | @end smallexample | |
1690 | ||
c906108c | 1691 | |
6d2ebf8b | 1692 | @node Help |
79a6e687 | 1693 | @section Getting Help |
c906108c SS |
1694 | @cindex online documentation |
1695 | @kindex help | |
1696 | ||
5d161b24 | 1697 | You can always ask @value{GDBN} itself for information on its commands, |
c906108c SS |
1698 | using the command @code{help}. |
1699 | ||
1700 | @table @code | |
41afff9a | 1701 | @kindex h @r{(@code{help})} |
c906108c SS |
1702 | @item help |
1703 | @itemx h | |
1704 | You can use @code{help} (abbreviated @code{h}) with no arguments to | |
1705 | display a short list of named classes of commands: | |
1706 | ||
1707 | @smallexample | |
1708 | (@value{GDBP}) help | |
1709 | List of classes of commands: | |
1710 | ||
2df3850c | 1711 | aliases -- Aliases of other commands |
c906108c | 1712 | breakpoints -- Making program stop at certain points |
2df3850c | 1713 | data -- Examining data |
c906108c | 1714 | files -- Specifying and examining files |
2df3850c JM |
1715 | internals -- Maintenance commands |
1716 | obscure -- Obscure features | |
1717 | running -- Running the program | |
1718 | stack -- Examining the stack | |
c906108c SS |
1719 | status -- Status inquiries |
1720 | support -- Support facilities | |
12c27660 | 1721 | tracepoints -- Tracing of program execution without |
96a2c332 | 1722 | stopping the program |
c906108c | 1723 | user-defined -- User-defined commands |
c906108c | 1724 | |
5d161b24 | 1725 | Type "help" followed by a class name for a list of |
c906108c | 1726 | commands in that class. |
5d161b24 | 1727 | Type "help" followed by command name for full |
c906108c SS |
1728 | documentation. |
1729 | Command name abbreviations are allowed if unambiguous. | |
1730 | (@value{GDBP}) | |
1731 | @end smallexample | |
96a2c332 | 1732 | @c the above line break eliminates huge line overfull... |
c906108c SS |
1733 | |
1734 | @item help @var{class} | |
1735 | Using one of the general help classes as an argument, you can get a | |
1736 | list of the individual commands in that class. For example, here is the | |
1737 | help display for the class @code{status}: | |
1738 | ||
1739 | @smallexample | |
1740 | (@value{GDBP}) help status | |
1741 | Status inquiries. | |
1742 | ||
1743 | List of commands: | |
1744 | ||
1745 | @c Line break in "show" line falsifies real output, but needed | |
1746 | @c to fit in smallbook page size. | |
2df3850c | 1747 | info -- Generic command for showing things |
12c27660 | 1748 | about the program being debugged |
2df3850c | 1749 | show -- Generic command for showing things |
12c27660 | 1750 | about the debugger |
c906108c | 1751 | |
5d161b24 | 1752 | Type "help" followed by command name for full |
c906108c SS |
1753 | documentation. |
1754 | Command name abbreviations are allowed if unambiguous. | |
1755 | (@value{GDBP}) | |
1756 | @end smallexample | |
1757 | ||
1758 | @item help @var{command} | |
1759 | With a command name as @code{help} argument, @value{GDBN} displays a | |
1760 | short paragraph on how to use that command. | |
1761 | ||
6837a0a2 DB |
1762 | @kindex apropos |
1763 | @item apropos @var{args} | |
09d4efe1 | 1764 | The @code{apropos} command searches through all of the @value{GDBN} |
6837a0a2 | 1765 | commands, and their documentation, for the regular expression specified in |
99e008fe | 1766 | @var{args}. It prints out all matches found. For example: |
6837a0a2 DB |
1767 | |
1768 | @smallexample | |
16899756 | 1769 | apropos alias |
6837a0a2 DB |
1770 | @end smallexample |
1771 | ||
b37052ae EZ |
1772 | @noindent |
1773 | results in: | |
6837a0a2 DB |
1774 | |
1775 | @smallexample | |
6d2ebf8b | 1776 | @c @group |
16899756 DE |
1777 | alias -- Define a new command that is an alias of an existing command |
1778 | aliases -- Aliases of other commands | |
1779 | d -- Delete some breakpoints or auto-display expressions | |
1780 | del -- Delete some breakpoints or auto-display expressions | |
1781 | delete -- Delete some breakpoints or auto-display expressions | |
6d2ebf8b | 1782 | @c @end group |
6837a0a2 DB |
1783 | @end smallexample |
1784 | ||
c906108c SS |
1785 | @kindex complete |
1786 | @item complete @var{args} | |
1787 | The @code{complete @var{args}} command lists all the possible completions | |
1788 | for the beginning of a command. Use @var{args} to specify the beginning of the | |
1789 | command you want completed. For example: | |
1790 | ||
1791 | @smallexample | |
1792 | complete i | |
1793 | @end smallexample | |
1794 | ||
1795 | @noindent results in: | |
1796 | ||
1797 | @smallexample | |
1798 | @group | |
2df3850c JM |
1799 | if |
1800 | ignore | |
c906108c SS |
1801 | info |
1802 | inspect | |
c906108c SS |
1803 | @end group |
1804 | @end smallexample | |
1805 | ||
1806 | @noindent This is intended for use by @sc{gnu} Emacs. | |
1807 | @end table | |
1808 | ||
1809 | In addition to @code{help}, you can use the @value{GDBN} commands @code{info} | |
1810 | and @code{show} to inquire about the state of your program, or the state | |
1811 | of @value{GDBN} itself. Each command supports many topics of inquiry; this | |
1812 | manual introduces each of them in the appropriate context. The listings | |
00595b5e EZ |
1813 | under @code{info} and under @code{show} in the Command, Variable, and |
1814 | Function Index point to all the sub-commands. @xref{Command and Variable | |
1815 | Index}. | |
c906108c SS |
1816 | |
1817 | @c @group | |
1818 | @table @code | |
1819 | @kindex info | |
41afff9a | 1820 | @kindex i @r{(@code{info})} |
c906108c SS |
1821 | @item info |
1822 | This command (abbreviated @code{i}) is for describing the state of your | |
cda4ce5a | 1823 | program. For example, you can show the arguments passed to a function |
c906108c SS |
1824 | with @code{info args}, list the registers currently in use with @code{info |
1825 | registers}, or list the breakpoints you have set with @code{info breakpoints}. | |
1826 | You can get a complete list of the @code{info} sub-commands with | |
1827 | @w{@code{help info}}. | |
1828 | ||
1829 | @kindex set | |
1830 | @item set | |
5d161b24 | 1831 | You can assign the result of an expression to an environment variable with |
c906108c SS |
1832 | @code{set}. For example, you can set the @value{GDBN} prompt to a $-sign with |
1833 | @code{set prompt $}. | |
1834 | ||
1835 | @kindex show | |
1836 | @item show | |
5d161b24 | 1837 | In contrast to @code{info}, @code{show} is for describing the state of |
c906108c SS |
1838 | @value{GDBN} itself. |
1839 | You can change most of the things you can @code{show}, by using the | |
1840 | related command @code{set}; for example, you can control what number | |
1841 | system is used for displays with @code{set radix}, or simply inquire | |
1842 | which is currently in use with @code{show radix}. | |
1843 | ||
1844 | @kindex info set | |
1845 | To display all the settable parameters and their current | |
1846 | values, you can use @code{show} with no arguments; you may also use | |
1847 | @code{info set}. Both commands produce the same display. | |
1848 | @c FIXME: "info set" violates the rule that "info" is for state of | |
1849 | @c FIXME...program. Ck w/ GNU: "info set" to be called something else, | |
1850 | @c FIXME...or change desc of rule---eg "state of prog and debugging session"? | |
1851 | @end table | |
1852 | @c @end group | |
1853 | ||
6eaaf48b | 1854 | Here are several miscellaneous @code{show} subcommands, all of which are |
c906108c SS |
1855 | exceptional in lacking corresponding @code{set} commands: |
1856 | ||
1857 | @table @code | |
1858 | @kindex show version | |
9c16f35a | 1859 | @cindex @value{GDBN} version number |
c906108c SS |
1860 | @item show version |
1861 | Show what version of @value{GDBN} is running. You should include this | |
2df3850c JM |
1862 | information in @value{GDBN} bug-reports. If multiple versions of |
1863 | @value{GDBN} are in use at your site, you may need to determine which | |
1864 | version of @value{GDBN} you are running; as @value{GDBN} evolves, new | |
1865 | commands are introduced, and old ones may wither away. Also, many | |
1866 | system vendors ship variant versions of @value{GDBN}, and there are | |
96a2c332 | 1867 | variant versions of @value{GDBN} in @sc{gnu}/Linux distributions as well. |
2df3850c JM |
1868 | The version number is the same as the one announced when you start |
1869 | @value{GDBN}. | |
c906108c SS |
1870 | |
1871 | @kindex show copying | |
09d4efe1 | 1872 | @kindex info copying |
9c16f35a | 1873 | @cindex display @value{GDBN} copyright |
c906108c | 1874 | @item show copying |
09d4efe1 | 1875 | @itemx info copying |
c906108c SS |
1876 | Display information about permission for copying @value{GDBN}. |
1877 | ||
1878 | @kindex show warranty | |
09d4efe1 | 1879 | @kindex info warranty |
c906108c | 1880 | @item show warranty |
09d4efe1 | 1881 | @itemx info warranty |
2df3850c | 1882 | Display the @sc{gnu} ``NO WARRANTY'' statement, or a warranty, |
96a2c332 | 1883 | if your version of @value{GDBN} comes with one. |
2df3850c | 1884 | |
6eaaf48b EZ |
1885 | @kindex show configuration |
1886 | @item show configuration | |
1887 | Display detailed information about the way @value{GDBN} was configured | |
1888 | when it was built. This displays the optional arguments passed to the | |
1889 | @file{configure} script and also configuration parameters detected | |
1890 | automatically by @command{configure}. When reporting a @value{GDBN} | |
1891 | bug (@pxref{GDB Bugs}), it is important to include this information in | |
1892 | your report. | |
1893 | ||
c906108c SS |
1894 | @end table |
1895 | ||
6d2ebf8b | 1896 | @node Running |
c906108c SS |
1897 | @chapter Running Programs Under @value{GDBN} |
1898 | ||
1899 | When you run a program under @value{GDBN}, you must first generate | |
1900 | debugging information when you compile it. | |
7a292a7a SS |
1901 | |
1902 | You may start @value{GDBN} with its arguments, if any, in an environment | |
1903 | of your choice. If you are doing native debugging, you may redirect | |
1904 | your program's input and output, debug an already running process, or | |
1905 | kill a child process. | |
c906108c SS |
1906 | |
1907 | @menu | |
1908 | * Compilation:: Compiling for debugging | |
1909 | * Starting:: Starting your program | |
c906108c SS |
1910 | * Arguments:: Your program's arguments |
1911 | * Environment:: Your program's environment | |
c906108c SS |
1912 | |
1913 | * Working Directory:: Your program's working directory | |
1914 | * Input/Output:: Your program's input and output | |
1915 | * Attach:: Debugging an already-running process | |
1916 | * Kill Process:: Killing the child process | |
c906108c | 1917 | |
6c95b8df | 1918 | * Inferiors and Programs:: Debugging multiple inferiors and programs |
c906108c | 1919 | * Threads:: Debugging programs with multiple threads |
6c95b8df | 1920 | * Forks:: Debugging forks |
5c95884b | 1921 | * Checkpoint/Restart:: Setting a @emph{bookmark} to return to later |
c906108c SS |
1922 | @end menu |
1923 | ||
6d2ebf8b | 1924 | @node Compilation |
79a6e687 | 1925 | @section Compiling for Debugging |
c906108c SS |
1926 | |
1927 | In order to debug a program effectively, you need to generate | |
1928 | debugging information when you compile it. This debugging information | |
1929 | is stored in the object file; it describes the data type of each | |
1930 | variable or function and the correspondence between source line numbers | |
1931 | and addresses in the executable code. | |
1932 | ||
1933 | To request debugging information, specify the @samp{-g} option when you run | |
1934 | the compiler. | |
1935 | ||
514c4d71 | 1936 | Programs that are to be shipped to your customers are compiled with |
edb3359d | 1937 | optimizations, using the @samp{-O} compiler option. However, some |
514c4d71 EZ |
1938 | compilers are unable to handle the @samp{-g} and @samp{-O} options |
1939 | together. Using those compilers, you cannot generate optimized | |
c906108c SS |
1940 | executables containing debugging information. |
1941 | ||
514c4d71 | 1942 | @value{NGCC}, the @sc{gnu} C/C@t{++} compiler, supports @samp{-g} with or |
53a5351d JM |
1943 | without @samp{-O}, making it possible to debug optimized code. We |
1944 | recommend that you @emph{always} use @samp{-g} whenever you compile a | |
1945 | program. You may think your program is correct, but there is no sense | |
edb3359d | 1946 | in pushing your luck. For more information, see @ref{Optimized Code}. |
c906108c SS |
1947 | |
1948 | Older versions of the @sc{gnu} C compiler permitted a variant option | |
1949 | @w{@samp{-gg}} for debugging information. @value{GDBN} no longer supports this | |
1950 | format; if your @sc{gnu} C compiler has this option, do not use it. | |
1951 | ||
514c4d71 EZ |
1952 | @value{GDBN} knows about preprocessor macros and can show you their |
1953 | expansion (@pxref{Macros}). Most compilers do not include information | |
1954 | about preprocessor macros in the debugging information if you specify | |
e0f8f636 TT |
1955 | the @option{-g} flag alone. Version 3.1 and later of @value{NGCC}, |
1956 | the @sc{gnu} C compiler, provides macro information if you are using | |
1957 | the DWARF debugging format, and specify the option @option{-g3}. | |
1958 | ||
1959 | @xref{Debugging Options,,Options for Debugging Your Program or GCC, | |
1960 | gcc.info, Using the @sc{gnu} Compiler Collection (GCC)}, for more | |
1961 | information on @value{NGCC} options affecting debug information. | |
1962 | ||
1963 | You will have the best debugging experience if you use the latest | |
1964 | version of the DWARF debugging format that your compiler supports. | |
1965 | DWARF is currently the most expressive and best supported debugging | |
1966 | format in @value{GDBN}. | |
514c4d71 | 1967 | |
c906108c | 1968 | @need 2000 |
6d2ebf8b | 1969 | @node Starting |
79a6e687 | 1970 | @section Starting your Program |
c906108c SS |
1971 | @cindex starting |
1972 | @cindex running | |
1973 | ||
1974 | @table @code | |
1975 | @kindex run | |
41afff9a | 1976 | @kindex r @r{(@code{run})} |
c906108c SS |
1977 | @item run |
1978 | @itemx r | |
7a292a7a | 1979 | Use the @code{run} command to start your program under @value{GDBN}. |
deb8ff2b PA |
1980 | You must first specify the program name with an argument to |
1981 | @value{GDBN} (@pxref{Invocation, ,Getting In and Out of | |
1982 | @value{GDBN}}), or by using the @code{file} or @code{exec-file} | |
1983 | command (@pxref{Files, ,Commands to Specify Files}). | |
c906108c SS |
1984 | |
1985 | @end table | |
1986 | ||
c906108c SS |
1987 | If you are running your program in an execution environment that |
1988 | supports processes, @code{run} creates an inferior process and makes | |
8edfe269 DJ |
1989 | that process run your program. In some environments without processes, |
1990 | @code{run} jumps to the start of your program. Other targets, | |
1991 | like @samp{remote}, are always running. If you get an error | |
1992 | message like this one: | |
1993 | ||
1994 | @smallexample | |
1995 | The "remote" target does not support "run". | |
1996 | Try "help target" or "continue". | |
1997 | @end smallexample | |
1998 | ||
1999 | @noindent | |
2000 | then use @code{continue} to run your program. You may need @code{load} | |
2001 | first (@pxref{load}). | |
c906108c SS |
2002 | |
2003 | The execution of a program is affected by certain information it | |
2004 | receives from its superior. @value{GDBN} provides ways to specify this | |
2005 | information, which you must do @emph{before} starting your program. (You | |
2006 | can change it after starting your program, but such changes only affect | |
2007 | your program the next time you start it.) This information may be | |
2008 | divided into four categories: | |
2009 | ||
2010 | @table @asis | |
2011 | @item The @emph{arguments.} | |
2012 | Specify the arguments to give your program as the arguments of the | |
2013 | @code{run} command. If a shell is available on your target, the shell | |
2014 | is used to pass the arguments, so that you may use normal conventions | |
2015 | (such as wildcard expansion or variable substitution) in describing | |
2016 | the arguments. | |
2017 | In Unix systems, you can control which shell is used with the | |
98882a26 PA |
2018 | @code{SHELL} environment variable. If you do not define @code{SHELL}, |
2019 | @value{GDBN} uses the default shell (@file{/bin/sh}). You can disable | |
2020 | use of any shell with the @code{set startup-with-shell} command (see | |
2021 | below for details). | |
c906108c SS |
2022 | |
2023 | @item The @emph{environment.} | |
2024 | Your program normally inherits its environment from @value{GDBN}, but you can | |
2025 | use the @value{GDBN} commands @code{set environment} and @code{unset | |
2026 | environment} to change parts of the environment that affect | |
79a6e687 | 2027 | your program. @xref{Environment, ,Your Program's Environment}. |
c906108c SS |
2028 | |
2029 | @item The @emph{working directory.} | |
2030 | Your program inherits its working directory from @value{GDBN}. You can set | |
2031 | the @value{GDBN} working directory with the @code{cd} command in @value{GDBN}. | |
79a6e687 | 2032 | @xref{Working Directory, ,Your Program's Working Directory}. |
c906108c SS |
2033 | |
2034 | @item The @emph{standard input and output.} | |
2035 | Your program normally uses the same device for standard input and | |
2036 | standard output as @value{GDBN} is using. You can redirect input and output | |
2037 | in the @code{run} command line, or you can use the @code{tty} command to | |
2038 | set a different device for your program. | |
79a6e687 | 2039 | @xref{Input/Output, ,Your Program's Input and Output}. |
c906108c SS |
2040 | |
2041 | @cindex pipes | |
2042 | @emph{Warning:} While input and output redirection work, you cannot use | |
2043 | pipes to pass the output of the program you are debugging to another | |
2044 | program; if you attempt this, @value{GDBN} is likely to wind up debugging the | |
2045 | wrong program. | |
2046 | @end table | |
c906108c SS |
2047 | |
2048 | When you issue the @code{run} command, your program begins to execute | |
79a6e687 | 2049 | immediately. @xref{Stopping, ,Stopping and Continuing}, for discussion |
c906108c SS |
2050 | of how to arrange for your program to stop. Once your program has |
2051 | stopped, you may call functions in your program, using the @code{print} | |
2052 | or @code{call} commands. @xref{Data, ,Examining Data}. | |
2053 | ||
2054 | If the modification time of your symbol file has changed since the last | |
2055 | time @value{GDBN} read its symbols, @value{GDBN} discards its symbol | |
2056 | table, and reads it again. When it does this, @value{GDBN} tries to retain | |
2057 | your current breakpoints. | |
2058 | ||
4e8b0763 JB |
2059 | @table @code |
2060 | @kindex start | |
2061 | @item start | |
2062 | @cindex run to main procedure | |
2063 | The name of the main procedure can vary from language to language. | |
2064 | With C or C@t{++}, the main procedure name is always @code{main}, but | |
2065 | other languages such as Ada do not require a specific name for their | |
2066 | main procedure. The debugger provides a convenient way to start the | |
2067 | execution of the program and to stop at the beginning of the main | |
2068 | procedure, depending on the language used. | |
2069 | ||
2070 | The @samp{start} command does the equivalent of setting a temporary | |
2071 | breakpoint at the beginning of the main procedure and then invoking | |
2072 | the @samp{run} command. | |
2073 | ||
f018e82f EZ |
2074 | @cindex elaboration phase |
2075 | Some programs contain an @dfn{elaboration} phase where some startup code is | |
2076 | executed before the main procedure is called. This depends on the | |
2077 | languages used to write your program. In C@t{++}, for instance, | |
4e8b0763 JB |
2078 | constructors for static and global objects are executed before |
2079 | @code{main} is called. It is therefore possible that the debugger stops | |
2080 | before reaching the main procedure. However, the temporary breakpoint | |
2081 | will remain to halt execution. | |
2082 | ||
2083 | Specify the arguments to give to your program as arguments to the | |
2084 | @samp{start} command. These arguments will be given verbatim to the | |
2085 | underlying @samp{run} command. Note that the same arguments will be | |
2086 | reused if no argument is provided during subsequent calls to | |
2087 | @samp{start} or @samp{run}. | |
2088 | ||
2089 | It is sometimes necessary to debug the program during elaboration. In | |
2090 | these cases, using the @code{start} command would stop the execution of | |
2091 | your program too late, as the program would have already completed the | |
2092 | elaboration phase. Under these circumstances, insert breakpoints in your | |
2093 | elaboration code before running your program. | |
ccd213ac | 2094 | |
41ef2965 | 2095 | @anchor{set exec-wrapper} |
ccd213ac DJ |
2096 | @kindex set exec-wrapper |
2097 | @item set exec-wrapper @var{wrapper} | |
2098 | @itemx show exec-wrapper | |
2099 | @itemx unset exec-wrapper | |
2100 | When @samp{exec-wrapper} is set, the specified wrapper is used to | |
2101 | launch programs for debugging. @value{GDBN} starts your program | |
2102 | with a shell command of the form @kbd{exec @var{wrapper} | |
2103 | @var{program}}. Quoting is added to @var{program} and its | |
2104 | arguments, but not to @var{wrapper}, so you should add quotes if | |
2105 | appropriate for your shell. The wrapper runs until it executes | |
2106 | your program, and then @value{GDBN} takes control. | |
2107 | ||
2108 | You can use any program that eventually calls @code{execve} with | |
2109 | its arguments as a wrapper. Several standard Unix utilities do | |
2110 | this, e.g.@: @code{env} and @code{nohup}. Any Unix shell script ending | |
2111 | with @code{exec "$@@"} will also work. | |
2112 | ||
2113 | For example, you can use @code{env} to pass an environment variable to | |
2114 | the debugged program, without setting the variable in your shell's | |
2115 | environment: | |
2116 | ||
2117 | @smallexample | |
2118 | (@value{GDBP}) set exec-wrapper env 'LD_PRELOAD=libtest.so' | |
2119 | (@value{GDBP}) run | |
2120 | @end smallexample | |
2121 | ||
2122 | This command is available when debugging locally on most targets, excluding | |
2123 | @sc{djgpp}, Cygwin, MS Windows, and QNX Neutrino. | |
2124 | ||
98882a26 PA |
2125 | @kindex set startup-with-shell |
2126 | @item set startup-with-shell | |
2127 | @itemx set startup-with-shell on | |
2128 | @itemx set startup-with-shell off | |
2129 | @itemx show set startup-with-shell | |
2130 | On Unix systems, by default, if a shell is available on your target, | |
2131 | @value{GDBN}) uses it to start your program. Arguments of the | |
2132 | @code{run} command are passed to the shell, which does variable | |
2133 | substitution, expands wildcard characters and performs redirection of | |
2134 | I/O. In some circumstances, it may be useful to disable such use of a | |
2135 | shell, for example, when debugging the shell itself or diagnosing | |
2136 | startup failures such as: | |
2137 | ||
2138 | @smallexample | |
2139 | (@value{GDBP}) run | |
2140 | Starting program: ./a.out | |
2141 | During startup program terminated with signal SIGSEGV, Segmentation fault. | |
2142 | @end smallexample | |
2143 | ||
2144 | @noindent | |
2145 | which indicates the shell or the wrapper specified with | |
2146 | @samp{exec-wrapper} crashed, not your program. Most often, this is | |
afa332ce PA |
2147 | caused by something odd in your shell's non-interactive mode |
2148 | initialization file---such as @file{.cshrc} for C-shell, | |
2149 | $@file{.zshenv} for the Z shell, or the file specified in the | |
2150 | @samp{BASH_ENV} environment variable for BASH. | |
98882a26 | 2151 | |
6a3cb8e8 PA |
2152 | @anchor{set auto-connect-native-target} |
2153 | @kindex set auto-connect-native-target | |
2154 | @item set auto-connect-native-target | |
2155 | @itemx set auto-connect-native-target on | |
2156 | @itemx set auto-connect-native-target off | |
2157 | @itemx show auto-connect-native-target | |
2158 | ||
2159 | By default, if not connected to any target yet (e.g., with | |
2160 | @code{target remote}), the @code{run} command starts your program as a | |
2161 | native process under @value{GDBN}, on your local machine. If you're | |
2162 | sure you don't want to debug programs on your local machine, you can | |
2163 | tell @value{GDBN} to not connect to the native target automatically | |
2164 | with the @code{set auto-connect-native-target off} command. | |
2165 | ||
2166 | If @code{on}, which is the default, and if @value{GDBN} is not | |
2167 | connected to a target already, the @code{run} command automaticaly | |
2168 | connects to the native target, if one is available. | |
2169 | ||
2170 | If @code{off}, and if @value{GDBN} is not connected to a target | |
2171 | already, the @code{run} command fails with an error: | |
2172 | ||
2173 | @smallexample | |
2174 | (@value{GDBP}) run | |
2175 | Don't know how to run. Try "help target". | |
2176 | @end smallexample | |
2177 | ||
2178 | If @value{GDBN} is already connected to a target, @value{GDBN} always | |
2179 | uses it with the @code{run} command. | |
2180 | ||
2181 | In any case, you can explicitly connect to the native target with the | |
2182 | @code{target native} command. For example, | |
2183 | ||
2184 | @smallexample | |
2185 | (@value{GDBP}) set auto-connect-native-target off | |
2186 | (@value{GDBP}) run | |
2187 | Don't know how to run. Try "help target". | |
2188 | (@value{GDBP}) target native | |
2189 | (@value{GDBP}) run | |
2190 | Starting program: ./a.out | |
2191 | [Inferior 1 (process 10421) exited normally] | |
2192 | @end smallexample | |
2193 | ||
2194 | In case you connected explicitly to the @code{native} target, | |
2195 | @value{GDBN} remains connected even if all inferiors exit, ready for | |
2196 | the next @code{run} command. Use the @code{disconnect} command to | |
2197 | disconnect. | |
2198 | ||
2199 | Examples of other commands that likewise respect the | |
2200 | @code{auto-connect-native-target} setting: @code{attach}, @code{info | |
2201 | proc}, @code{info os}. | |
2202 | ||
10568435 JK |
2203 | @kindex set disable-randomization |
2204 | @item set disable-randomization | |
2205 | @itemx set disable-randomization on | |
2206 | This option (enabled by default in @value{GDBN}) will turn off the native | |
2207 | randomization of the virtual address space of the started program. This option | |
2208 | is useful for multiple debugging sessions to make the execution better | |
2209 | reproducible and memory addresses reusable across debugging sessions. | |
2210 | ||
03583c20 UW |
2211 | This feature is implemented only on certain targets, including @sc{gnu}/Linux. |
2212 | On @sc{gnu}/Linux you can get the same behavior using | |
10568435 JK |
2213 | |
2214 | @smallexample | |
2215 | (@value{GDBP}) set exec-wrapper setarch `uname -m` -R | |
2216 | @end smallexample | |
2217 | ||
2218 | @item set disable-randomization off | |
2219 | Leave the behavior of the started executable unchanged. Some bugs rear their | |
2220 | ugly heads only when the program is loaded at certain addresses. If your bug | |
2221 | disappears when you run the program under @value{GDBN}, that might be because | |
2222 | @value{GDBN} by default disables the address randomization on platforms, such | |
2223 | as @sc{gnu}/Linux, which do that for stand-alone programs. Use @kbd{set | |
2224 | disable-randomization off} to try to reproduce such elusive bugs. | |
2225 | ||
03583c20 UW |
2226 | On targets where it is available, virtual address space randomization |
2227 | protects the programs against certain kinds of security attacks. In these | |
10568435 JK |
2228 | cases the attacker needs to know the exact location of a concrete executable |
2229 | code. Randomizing its location makes it impossible to inject jumps misusing | |
2230 | a code at its expected addresses. | |
2231 | ||
2232 | Prelinking shared libraries provides a startup performance advantage but it | |
2233 | makes addresses in these libraries predictable for privileged processes by | |
2234 | having just unprivileged access at the target system. Reading the shared | |
2235 | library binary gives enough information for assembling the malicious code | |
2236 | misusing it. Still even a prelinked shared library can get loaded at a new | |
2237 | random address just requiring the regular relocation process during the | |
2238 | startup. Shared libraries not already prelinked are always loaded at | |
2239 | a randomly chosen address. | |
2240 | ||
2241 | Position independent executables (PIE) contain position independent code | |
2242 | similar to the shared libraries and therefore such executables get loaded at | |
2243 | a randomly chosen address upon startup. PIE executables always load even | |
2244 | already prelinked shared libraries at a random address. You can build such | |
2245 | executable using @command{gcc -fPIE -pie}. | |
2246 | ||
2247 | Heap (malloc storage), stack and custom mmap areas are always placed randomly | |
2248 | (as long as the randomization is enabled). | |
2249 | ||
2250 | @item show disable-randomization | |
2251 | Show the current setting of the explicit disable of the native randomization of | |
2252 | the virtual address space of the started program. | |
2253 | ||
4e8b0763 JB |
2254 | @end table |
2255 | ||
6d2ebf8b | 2256 | @node Arguments |
79a6e687 | 2257 | @section Your Program's Arguments |
c906108c SS |
2258 | |
2259 | @cindex arguments (to your program) | |
2260 | The arguments to your program can be specified by the arguments of the | |
5d161b24 | 2261 | @code{run} command. |
c906108c SS |
2262 | They are passed to a shell, which expands wildcard characters and |
2263 | performs redirection of I/O, and thence to your program. Your | |
2264 | @code{SHELL} environment variable (if it exists) specifies what shell | |
2265 | @value{GDBN} uses. If you do not define @code{SHELL}, @value{GDBN} uses | |
d4f3574e SS |
2266 | the default shell (@file{/bin/sh} on Unix). |
2267 | ||
2268 | On non-Unix systems, the program is usually invoked directly by | |
2269 | @value{GDBN}, which emulates I/O redirection via the appropriate system | |
2270 | calls, and the wildcard characters are expanded by the startup code of | |
2271 | the program, not by the shell. | |
c906108c SS |
2272 | |
2273 | @code{run} with no arguments uses the same arguments used by the previous | |
2274 | @code{run}, or those set by the @code{set args} command. | |
2275 | ||
c906108c | 2276 | @table @code |
41afff9a | 2277 | @kindex set args |
c906108c SS |
2278 | @item set args |
2279 | Specify the arguments to be used the next time your program is run. If | |
2280 | @code{set args} has no arguments, @code{run} executes your program | |
2281 | with no arguments. Once you have run your program with arguments, | |
2282 | using @code{set args} before the next @code{run} is the only way to run | |
2283 | it again without arguments. | |
2284 | ||
2285 | @kindex show args | |
2286 | @item show args | |
2287 | Show the arguments to give your program when it is started. | |
2288 | @end table | |
2289 | ||
6d2ebf8b | 2290 | @node Environment |
79a6e687 | 2291 | @section Your Program's Environment |
c906108c SS |
2292 | |
2293 | @cindex environment (of your program) | |
2294 | The @dfn{environment} consists of a set of environment variables and | |
2295 | their values. Environment variables conventionally record such things as | |
2296 | your user name, your home directory, your terminal type, and your search | |
2297 | path for programs to run. Usually you set up environment variables with | |
2298 | the shell and they are inherited by all the other programs you run. When | |
2299 | debugging, it can be useful to try running your program with a modified | |
2300 | environment without having to start @value{GDBN} over again. | |
2301 | ||
2302 | @table @code | |
2303 | @kindex path | |
2304 | @item path @var{directory} | |
2305 | Add @var{directory} to the front of the @code{PATH} environment variable | |
17cc6a06 EZ |
2306 | (the search path for executables) that will be passed to your program. |
2307 | The value of @code{PATH} used by @value{GDBN} does not change. | |
d4f3574e SS |
2308 | You may specify several directory names, separated by whitespace or by a |
2309 | system-dependent separator character (@samp{:} on Unix, @samp{;} on | |
2310 | MS-DOS and MS-Windows). If @var{directory} is already in the path, it | |
2311 | is moved to the front, so it is searched sooner. | |
c906108c SS |
2312 | |
2313 | You can use the string @samp{$cwd} to refer to whatever is the current | |
2314 | working directory at the time @value{GDBN} searches the path. If you | |
2315 | use @samp{.} instead, it refers to the directory where you executed the | |
2316 | @code{path} command. @value{GDBN} replaces @samp{.} in the | |
2317 | @var{directory} argument (with the current path) before adding | |
2318 | @var{directory} to the search path. | |
2319 | @c 'path' is explicitly nonrepeatable, but RMS points out it is silly to | |
2320 | @c document that, since repeating it would be a no-op. | |
2321 | ||
2322 | @kindex show paths | |
2323 | @item show paths | |
2324 | Display the list of search paths for executables (the @code{PATH} | |
2325 | environment variable). | |
2326 | ||
2327 | @kindex show environment | |
2328 | @item show environment @r{[}@var{varname}@r{]} | |
2329 | Print the value of environment variable @var{varname} to be given to | |
2330 | your program when it starts. If you do not supply @var{varname}, | |
2331 | print the names and values of all environment variables to be given to | |
2332 | your program. You can abbreviate @code{environment} as @code{env}. | |
2333 | ||
2334 | @kindex set environment | |
53a5351d | 2335 | @item set environment @var{varname} @r{[}=@var{value}@r{]} |
c906108c | 2336 | Set environment variable @var{varname} to @var{value}. The value |
41ef2965 | 2337 | changes for your program (and the shell @value{GDBN} uses to launch |
697aa1b7 | 2338 | it), not for @value{GDBN} itself. The @var{value} may be any string; the |
41ef2965 PA |
2339 | values of environment variables are just strings, and any |
2340 | interpretation is supplied by your program itself. The @var{value} | |
c906108c SS |
2341 | parameter is optional; if it is eliminated, the variable is set to a |
2342 | null value. | |
2343 | @c "any string" here does not include leading, trailing | |
2344 | @c blanks. Gnu asks: does anyone care? | |
2345 | ||
2346 | For example, this command: | |
2347 | ||
474c8240 | 2348 | @smallexample |
c906108c | 2349 | set env USER = foo |
474c8240 | 2350 | @end smallexample |
c906108c SS |
2351 | |
2352 | @noindent | |
d4f3574e | 2353 | tells the debugged program, when subsequently run, that its user is named |
c906108c SS |
2354 | @samp{foo}. (The spaces around @samp{=} are used for clarity here; they |
2355 | are not actually required.) | |
2356 | ||
41ef2965 PA |
2357 | Note that on Unix systems, @value{GDBN} runs your program via a shell, |
2358 | which also inherits the environment set with @code{set environment}. | |
2359 | If necessary, you can avoid that by using the @samp{env} program as a | |
2360 | wrapper instead of using @code{set environment}. @xref{set | |
2361 | exec-wrapper}, for an example doing just that. | |
2362 | ||
c906108c SS |
2363 | @kindex unset environment |
2364 | @item unset environment @var{varname} | |
2365 | Remove variable @var{varname} from the environment to be passed to your | |
2366 | program. This is different from @samp{set env @var{varname} =}; | |
2367 | @code{unset environment} removes the variable from the environment, | |
2368 | rather than assigning it an empty value. | |
2369 | @end table | |
2370 | ||
d4f3574e | 2371 | @emph{Warning:} On Unix systems, @value{GDBN} runs your program using |
afa332ce PA |
2372 | the shell indicated by your @code{SHELL} environment variable if it |
2373 | exists (or @code{/bin/sh} if not). If your @code{SHELL} variable | |
2374 | names a shell that runs an initialization file when started | |
2375 | non-interactively---such as @file{.cshrc} for C-shell, $@file{.zshenv} | |
2376 | for the Z shell, or the file specified in the @samp{BASH_ENV} | |
2377 | environment variable for BASH---any variables you set in that file | |
2378 | affect your program. You may wish to move setting of environment | |
2379 | variables to files that are only run when you sign on, such as | |
2380 | @file{.login} or @file{.profile}. | |
c906108c | 2381 | |
6d2ebf8b | 2382 | @node Working Directory |
79a6e687 | 2383 | @section Your Program's Working Directory |
c906108c SS |
2384 | |
2385 | @cindex working directory (of your program) | |
2386 | Each time you start your program with @code{run}, it inherits its | |
2387 | working directory from the current working directory of @value{GDBN}. | |
2388 | The @value{GDBN} working directory is initially whatever it inherited | |
2389 | from its parent process (typically the shell), but you can specify a new | |
2390 | working directory in @value{GDBN} with the @code{cd} command. | |
2391 | ||
2392 | The @value{GDBN} working directory also serves as a default for the commands | |
2393 | that specify files for @value{GDBN} to operate on. @xref{Files, ,Commands to | |
79a6e687 | 2394 | Specify Files}. |
c906108c SS |
2395 | |
2396 | @table @code | |
2397 | @kindex cd | |
721c2651 | 2398 | @cindex change working directory |
f3c8a52a JK |
2399 | @item cd @r{[}@var{directory}@r{]} |
2400 | Set the @value{GDBN} working directory to @var{directory}. If not | |
2401 | given, @var{directory} uses @file{'~'}. | |
c906108c SS |
2402 | |
2403 | @kindex pwd | |
2404 | @item pwd | |
2405 | Print the @value{GDBN} working directory. | |
2406 | @end table | |
2407 | ||
60bf7e09 EZ |
2408 | It is generally impossible to find the current working directory of |
2409 | the process being debugged (since a program can change its directory | |
2410 | during its run). If you work on a system where @value{GDBN} is | |
2411 | configured with the @file{/proc} support, you can use the @code{info | |
2412 | proc} command (@pxref{SVR4 Process Information}) to find out the | |
2413 | current working directory of the debuggee. | |
2414 | ||
6d2ebf8b | 2415 | @node Input/Output |
79a6e687 | 2416 | @section Your Program's Input and Output |
c906108c SS |
2417 | |
2418 | @cindex redirection | |
2419 | @cindex i/o | |
2420 | @cindex terminal | |
2421 | By default, the program you run under @value{GDBN} does input and output to | |
5d161b24 | 2422 | the same terminal that @value{GDBN} uses. @value{GDBN} switches the terminal |
c906108c SS |
2423 | to its own terminal modes to interact with you, but it records the terminal |
2424 | modes your program was using and switches back to them when you continue | |
2425 | running your program. | |
2426 | ||
2427 | @table @code | |
2428 | @kindex info terminal | |
2429 | @item info terminal | |
2430 | Displays information recorded by @value{GDBN} about the terminal modes your | |
2431 | program is using. | |
2432 | @end table | |
2433 | ||
2434 | You can redirect your program's input and/or output using shell | |
2435 | redirection with the @code{run} command. For example, | |
2436 | ||
474c8240 | 2437 | @smallexample |
c906108c | 2438 | run > outfile |
474c8240 | 2439 | @end smallexample |
c906108c SS |
2440 | |
2441 | @noindent | |
2442 | starts your program, diverting its output to the file @file{outfile}. | |
2443 | ||
2444 | @kindex tty | |
2445 | @cindex controlling terminal | |
2446 | Another way to specify where your program should do input and output is | |
2447 | with the @code{tty} command. This command accepts a file name as | |
2448 | argument, and causes this file to be the default for future @code{run} | |
2449 | commands. It also resets the controlling terminal for the child | |
2450 | process, for future @code{run} commands. For example, | |
2451 | ||
474c8240 | 2452 | @smallexample |
c906108c | 2453 | tty /dev/ttyb |
474c8240 | 2454 | @end smallexample |
c906108c SS |
2455 | |
2456 | @noindent | |
2457 | directs that processes started with subsequent @code{run} commands | |
2458 | default to do input and output on the terminal @file{/dev/ttyb} and have | |
2459 | that as their controlling terminal. | |
2460 | ||
2461 | An explicit redirection in @code{run} overrides the @code{tty} command's | |
2462 | effect on the input/output device, but not its effect on the controlling | |
2463 | terminal. | |
2464 | ||
2465 | When you use the @code{tty} command or redirect input in the @code{run} | |
2466 | command, only the input @emph{for your program} is affected. The input | |
3cb3b8df BR |
2467 | for @value{GDBN} still comes from your terminal. @code{tty} is an alias |
2468 | for @code{set inferior-tty}. | |
2469 | ||
2470 | @cindex inferior tty | |
2471 | @cindex set inferior controlling terminal | |
2472 | You can use the @code{show inferior-tty} command to tell @value{GDBN} to | |
2473 | display the name of the terminal that will be used for future runs of your | |
2474 | program. | |
2475 | ||
2476 | @table @code | |
2477 | @item set inferior-tty /dev/ttyb | |
2478 | @kindex set inferior-tty | |
2479 | Set the tty for the program being debugged to /dev/ttyb. | |
2480 | ||
2481 | @item show inferior-tty | |
2482 | @kindex show inferior-tty | |
2483 | Show the current tty for the program being debugged. | |
2484 | @end table | |
c906108c | 2485 | |
6d2ebf8b | 2486 | @node Attach |
79a6e687 | 2487 | @section Debugging an Already-running Process |
c906108c SS |
2488 | @kindex attach |
2489 | @cindex attach | |
2490 | ||
2491 | @table @code | |
2492 | @item attach @var{process-id} | |
2493 | This command attaches to a running process---one that was started | |
2494 | outside @value{GDBN}. (@code{info files} shows your active | |
2495 | targets.) The command takes as argument a process ID. The usual way to | |
09d4efe1 | 2496 | find out the @var{process-id} of a Unix process is with the @code{ps} utility, |
c906108c SS |
2497 | or with the @samp{jobs -l} shell command. |
2498 | ||
2499 | @code{attach} does not repeat if you press @key{RET} a second time after | |
2500 | executing the command. | |
2501 | @end table | |
2502 | ||
2503 | To use @code{attach}, your program must be running in an environment | |
2504 | which supports processes; for example, @code{attach} does not work for | |
2505 | programs on bare-board targets that lack an operating system. You must | |
2506 | also have permission to send the process a signal. | |
2507 | ||
2508 | When you use @code{attach}, the debugger finds the program running in | |
2509 | the process first by looking in the current working directory, then (if | |
2510 | the program is not found) by using the source file search path | |
79a6e687 | 2511 | (@pxref{Source Path, ,Specifying Source Directories}). You can also use |
c906108c SS |
2512 | the @code{file} command to load the program. @xref{Files, ,Commands to |
2513 | Specify Files}. | |
2514 | ||
2515 | The first thing @value{GDBN} does after arranging to debug the specified | |
2516 | process is to stop it. You can examine and modify an attached process | |
53a5351d JM |
2517 | with all the @value{GDBN} commands that are ordinarily available when |
2518 | you start processes with @code{run}. You can insert breakpoints; you | |
2519 | can step and continue; you can modify storage. If you would rather the | |
2520 | process continue running, you may use the @code{continue} command after | |
c906108c SS |
2521 | attaching @value{GDBN} to the process. |
2522 | ||
2523 | @table @code | |
2524 | @kindex detach | |
2525 | @item detach | |
2526 | When you have finished debugging the attached process, you can use the | |
2527 | @code{detach} command to release it from @value{GDBN} control. Detaching | |
2528 | the process continues its execution. After the @code{detach} command, | |
2529 | that process and @value{GDBN} become completely independent once more, and you | |
2530 | are ready to @code{attach} another process or start one with @code{run}. | |
2531 | @code{detach} does not repeat if you press @key{RET} again after | |
2532 | executing the command. | |
2533 | @end table | |
2534 | ||
159fcc13 JK |
2535 | If you exit @value{GDBN} while you have an attached process, you detach |
2536 | that process. If you use the @code{run} command, you kill that process. | |
2537 | By default, @value{GDBN} asks for confirmation if you try to do either of these | |
2538 | things; you can control whether or not you need to confirm by using the | |
2539 | @code{set confirm} command (@pxref{Messages/Warnings, ,Optional Warnings and | |
79a6e687 | 2540 | Messages}). |
c906108c | 2541 | |
6d2ebf8b | 2542 | @node Kill Process |
79a6e687 | 2543 | @section Killing the Child Process |
c906108c SS |
2544 | |
2545 | @table @code | |
2546 | @kindex kill | |
2547 | @item kill | |
2548 | Kill the child process in which your program is running under @value{GDBN}. | |
2549 | @end table | |
2550 | ||
2551 | This command is useful if you wish to debug a core dump instead of a | |
2552 | running process. @value{GDBN} ignores any core dump file while your program | |
2553 | is running. | |
2554 | ||
2555 | On some operating systems, a program cannot be executed outside @value{GDBN} | |
2556 | while you have breakpoints set on it inside @value{GDBN}. You can use the | |
2557 | @code{kill} command in this situation to permit running your program | |
2558 | outside the debugger. | |
2559 | ||
2560 | The @code{kill} command is also useful if you wish to recompile and | |
2561 | relink your program, since on many systems it is impossible to modify an | |
2562 | executable file while it is running in a process. In this case, when you | |
2563 | next type @code{run}, @value{GDBN} notices that the file has changed, and | |
2564 | reads the symbol table again (while trying to preserve your current | |
2565 | breakpoint settings). | |
2566 | ||
6c95b8df PA |
2567 | @node Inferiors and Programs |
2568 | @section Debugging Multiple Inferiors and Programs | |
b77209e0 | 2569 | |
6c95b8df PA |
2570 | @value{GDBN} lets you run and debug multiple programs in a single |
2571 | session. In addition, @value{GDBN} on some systems may let you run | |
2572 | several programs simultaneously (otherwise you have to exit from one | |
2573 | before starting another). In the most general case, you can have | |
2574 | multiple threads of execution in each of multiple processes, launched | |
2575 | from multiple executables. | |
b77209e0 PA |
2576 | |
2577 | @cindex inferior | |
2578 | @value{GDBN} represents the state of each program execution with an | |
2579 | object called an @dfn{inferior}. An inferior typically corresponds to | |
2580 | a process, but is more general and applies also to targets that do not | |
2581 | have processes. Inferiors may be created before a process runs, and | |
6c95b8df PA |
2582 | may be retained after a process exits. Inferiors have unique |
2583 | identifiers that are different from process ids. Usually each | |
2584 | inferior will also have its own distinct address space, although some | |
2585 | embedded targets may have several inferiors running in different parts | |
2586 | of a single address space. Each inferior may in turn have multiple | |
2587 | threads running in it. | |
b77209e0 | 2588 | |
6c95b8df PA |
2589 | To find out what inferiors exist at any moment, use @w{@code{info |
2590 | inferiors}}: | |
b77209e0 PA |
2591 | |
2592 | @table @code | |
2593 | @kindex info inferiors | |
2594 | @item info inferiors | |
2595 | Print a list of all inferiors currently being managed by @value{GDBN}. | |
3a1ff0b6 PA |
2596 | |
2597 | @value{GDBN} displays for each inferior (in this order): | |
2598 | ||
2599 | @enumerate | |
2600 | @item | |
2601 | the inferior number assigned by @value{GDBN} | |
2602 | ||
2603 | @item | |
2604 | the target system's inferior identifier | |
6c95b8df PA |
2605 | |
2606 | @item | |
2607 | the name of the executable the inferior is running. | |
2608 | ||
3a1ff0b6 PA |
2609 | @end enumerate |
2610 | ||
2611 | @noindent | |
2612 | An asterisk @samp{*} preceding the @value{GDBN} inferior number | |
2613 | indicates the current inferior. | |
2614 | ||
2615 | For example, | |
2277426b | 2616 | @end table |
3a1ff0b6 PA |
2617 | @c end table here to get a little more width for example |
2618 | ||
2619 | @smallexample | |
2620 | (@value{GDBP}) info inferiors | |
6c95b8df PA |
2621 | Num Description Executable |
2622 | 2 process 2307 hello | |
2623 | * 1 process 3401 goodbye | |
3a1ff0b6 | 2624 | @end smallexample |
2277426b PA |
2625 | |
2626 | To switch focus between inferiors, use the @code{inferior} command: | |
2627 | ||
2628 | @table @code | |
3a1ff0b6 PA |
2629 | @kindex inferior @var{infno} |
2630 | @item inferior @var{infno} | |
2631 | Make inferior number @var{infno} the current inferior. The argument | |
2632 | @var{infno} is the inferior number assigned by @value{GDBN}, as shown | |
2633 | in the first field of the @samp{info inferiors} display. | |
2277426b PA |
2634 | @end table |
2635 | ||
6c95b8df PA |
2636 | |
2637 | You can get multiple executables into a debugging session via the | |
2638 | @code{add-inferior} and @w{@code{clone-inferior}} commands. On some | |
2639 | systems @value{GDBN} can add inferiors to the debug session | |
2640 | automatically by following calls to @code{fork} and @code{exec}. To | |
2641 | remove inferiors from the debugging session use the | |
af624141 | 2642 | @w{@code{remove-inferiors}} command. |
6c95b8df PA |
2643 | |
2644 | @table @code | |
2645 | @kindex add-inferior | |
2646 | @item add-inferior [ -copies @var{n} ] [ -exec @var{executable} ] | |
2647 | Adds @var{n} inferiors to be run using @var{executable} as the | |
697aa1b7 | 2648 | executable; @var{n} defaults to 1. If no executable is specified, |
6c95b8df PA |
2649 | the inferiors begins empty, with no program. You can still assign or |
2650 | change the program assigned to the inferior at any time by using the | |
2651 | @code{file} command with the executable name as its argument. | |
2652 | ||
2653 | @kindex clone-inferior | |
2654 | @item clone-inferior [ -copies @var{n} ] [ @var{infno} ] | |
2655 | Adds @var{n} inferiors ready to execute the same program as inferior | |
697aa1b7 | 2656 | @var{infno}; @var{n} defaults to 1, and @var{infno} defaults to the |
6c95b8df PA |
2657 | number of the current inferior. This is a convenient command when you |
2658 | want to run another instance of the inferior you are debugging. | |
2659 | ||
2660 | @smallexample | |
2661 | (@value{GDBP}) info inferiors | |
2662 | Num Description Executable | |
2663 | * 1 process 29964 helloworld | |
2664 | (@value{GDBP}) clone-inferior | |
2665 | Added inferior 2. | |
2666 | 1 inferiors added. | |
2667 | (@value{GDBP}) info inferiors | |
2668 | Num Description Executable | |
2669 | 2 <null> helloworld | |
2670 | * 1 process 29964 helloworld | |
2671 | @end smallexample | |
2672 | ||
2673 | You can now simply switch focus to inferior 2 and run it. | |
2674 | ||
af624141 MS |
2675 | @kindex remove-inferiors |
2676 | @item remove-inferiors @var{infno}@dots{} | |
2677 | Removes the inferior or inferiors @var{infno}@dots{}. It is not | |
2678 | possible to remove an inferior that is running with this command. For | |
2679 | those, use the @code{kill} or @code{detach} command first. | |
6c95b8df PA |
2680 | |
2681 | @end table | |
2682 | ||
2683 | To quit debugging one of the running inferiors that is not the current | |
2684 | inferior, you can either detach from it by using the @w{@code{detach | |
2685 | inferior}} command (allowing it to run independently), or kill it | |
af624141 | 2686 | using the @w{@code{kill inferiors}} command: |
2277426b PA |
2687 | |
2688 | @table @code | |
af624141 MS |
2689 | @kindex detach inferiors @var{infno}@dots{} |
2690 | @item detach inferior @var{infno}@dots{} | |
2691 | Detach from the inferior or inferiors identified by @value{GDBN} | |
5e30da2c | 2692 | inferior number(s) @var{infno}@dots{}. Note that the inferior's entry |
af624141 MS |
2693 | still stays on the list of inferiors shown by @code{info inferiors}, |
2694 | but its Description will show @samp{<null>}. | |
2695 | ||
2696 | @kindex kill inferiors @var{infno}@dots{} | |
2697 | @item kill inferiors @var{infno}@dots{} | |
2698 | Kill the inferior or inferiors identified by @value{GDBN} inferior | |
2699 | number(s) @var{infno}@dots{}. Note that the inferior's entry still | |
2700 | stays on the list of inferiors shown by @code{info inferiors}, but its | |
2701 | Description will show @samp{<null>}. | |
2277426b PA |
2702 | @end table |
2703 | ||
6c95b8df | 2704 | After the successful completion of a command such as @code{detach}, |
af624141 | 2705 | @code{detach inferiors}, @code{kill} or @code{kill inferiors}, or after |
6c95b8df PA |
2706 | a normal process exit, the inferior is still valid and listed with |
2707 | @code{info inferiors}, ready to be restarted. | |
2708 | ||
2709 | ||
2277426b PA |
2710 | To be notified when inferiors are started or exit under @value{GDBN}'s |
2711 | control use @w{@code{set print inferior-events}}: | |
b77209e0 | 2712 | |
2277426b | 2713 | @table @code |
b77209e0 PA |
2714 | @kindex set print inferior-events |
2715 | @cindex print messages on inferior start and exit | |
2716 | @item set print inferior-events | |
2717 | @itemx set print inferior-events on | |
2718 | @itemx set print inferior-events off | |
2719 | The @code{set print inferior-events} command allows you to enable or | |
2720 | disable printing of messages when @value{GDBN} notices that new | |
2721 | inferiors have started or that inferiors have exited or have been | |
2722 | detached. By default, these messages will not be printed. | |
2723 | ||
2724 | @kindex show print inferior-events | |
2725 | @item show print inferior-events | |
2726 | Show whether messages will be printed when @value{GDBN} detects that | |
2727 | inferiors have started, exited or have been detached. | |
2728 | @end table | |
2729 | ||
6c95b8df PA |
2730 | Many commands will work the same with multiple programs as with a |
2731 | single program: e.g., @code{print myglobal} will simply display the | |
2732 | value of @code{myglobal} in the current inferior. | |
2733 | ||
2734 | ||
2735 | Occasionaly, when debugging @value{GDBN} itself, it may be useful to | |
2736 | get more info about the relationship of inferiors, programs, address | |
2737 | spaces in a debug session. You can do that with the @w{@code{maint | |
2738 | info program-spaces}} command. | |
2739 | ||
2740 | @table @code | |
2741 | @kindex maint info program-spaces | |
2742 | @item maint info program-spaces | |
2743 | Print a list of all program spaces currently being managed by | |
2744 | @value{GDBN}. | |
2745 | ||
2746 | @value{GDBN} displays for each program space (in this order): | |
2747 | ||
2748 | @enumerate | |
2749 | @item | |
2750 | the program space number assigned by @value{GDBN} | |
2751 | ||
2752 | @item | |
2753 | the name of the executable loaded into the program space, with e.g., | |
2754 | the @code{file} command. | |
2755 | ||
2756 | @end enumerate | |
2757 | ||
2758 | @noindent | |
2759 | An asterisk @samp{*} preceding the @value{GDBN} program space number | |
2760 | indicates the current program space. | |
2761 | ||
2762 | In addition, below each program space line, @value{GDBN} prints extra | |
2763 | information that isn't suitable to display in tabular form. For | |
2764 | example, the list of inferiors bound to the program space. | |
2765 | ||
2766 | @smallexample | |
2767 | (@value{GDBP}) maint info program-spaces | |
2768 | Id Executable | |
2769 | 2 goodbye | |
2770 | Bound inferiors: ID 1 (process 21561) | |
2771 | * 1 hello | |
2772 | @end smallexample | |
2773 | ||
2774 | Here we can see that no inferior is running the program @code{hello}, | |
2775 | while @code{process 21561} is running the program @code{goodbye}. On | |
2776 | some targets, it is possible that multiple inferiors are bound to the | |
2777 | same program space. The most common example is that of debugging both | |
2778 | the parent and child processes of a @code{vfork} call. For example, | |
2779 | ||
2780 | @smallexample | |
2781 | (@value{GDBP}) maint info program-spaces | |
2782 | Id Executable | |
2783 | * 1 vfork-test | |
2784 | Bound inferiors: ID 2 (process 18050), ID 1 (process 18045) | |
2785 | @end smallexample | |
2786 | ||
2787 | Here, both inferior 2 and inferior 1 are running in the same program | |
2788 | space as a result of inferior 1 having executed a @code{vfork} call. | |
2789 | @end table | |
2790 | ||
6d2ebf8b | 2791 | @node Threads |
79a6e687 | 2792 | @section Debugging Programs with Multiple Threads |
c906108c SS |
2793 | |
2794 | @cindex threads of execution | |
2795 | @cindex multiple threads | |
2796 | @cindex switching threads | |
2797 | In some operating systems, such as HP-UX and Solaris, a single program | |
2798 | may have more than one @dfn{thread} of execution. The precise semantics | |
2799 | of threads differ from one operating system to another, but in general | |
2800 | the threads of a single program are akin to multiple processes---except | |
2801 | that they share one address space (that is, they can all examine and | |
2802 | modify the same variables). On the other hand, each thread has its own | |
2803 | registers and execution stack, and perhaps private memory. | |
2804 | ||
2805 | @value{GDBN} provides these facilities for debugging multi-thread | |
2806 | programs: | |
2807 | ||
2808 | @itemize @bullet | |
2809 | @item automatic notification of new threads | |
2810 | @item @samp{thread @var{threadno}}, a command to switch among threads | |
2811 | @item @samp{info threads}, a command to inquire about existing threads | |
5d161b24 | 2812 | @item @samp{thread apply [@var{threadno}] [@var{all}] @var{args}}, |
c906108c SS |
2813 | a command to apply a command to a list of threads |
2814 | @item thread-specific breakpoints | |
93815fbf VP |
2815 | @item @samp{set print thread-events}, which controls printing of |
2816 | messages on thread start and exit. | |
17a37d48 PP |
2817 | @item @samp{set libthread-db-search-path @var{path}}, which lets |
2818 | the user specify which @code{libthread_db} to use if the default choice | |
2819 | isn't compatible with the program. | |
c906108c SS |
2820 | @end itemize |
2821 | ||
c906108c SS |
2822 | @quotation |
2823 | @emph{Warning:} These facilities are not yet available on every | |
2824 | @value{GDBN} configuration where the operating system supports threads. | |
2825 | If your @value{GDBN} does not support threads, these commands have no | |
2826 | effect. For example, a system without thread support shows no output | |
2827 | from @samp{info threads}, and always rejects the @code{thread} command, | |
2828 | like this: | |
2829 | ||
2830 | @smallexample | |
2831 | (@value{GDBP}) info threads | |
2832 | (@value{GDBP}) thread 1 | |
2833 | Thread ID 1 not known. Use the "info threads" command to | |
2834 | see the IDs of currently known threads. | |
2835 | @end smallexample | |
2836 | @c FIXME to implementors: how hard would it be to say "sorry, this GDB | |
2837 | @c doesn't support threads"? | |
2838 | @end quotation | |
c906108c SS |
2839 | |
2840 | @cindex focus of debugging | |
2841 | @cindex current thread | |
2842 | The @value{GDBN} thread debugging facility allows you to observe all | |
2843 | threads while your program runs---but whenever @value{GDBN} takes | |
2844 | control, one thread in particular is always the focus of debugging. | |
2845 | This thread is called the @dfn{current thread}. Debugging commands show | |
2846 | program information from the perspective of the current thread. | |
2847 | ||
41afff9a | 2848 | @cindex @code{New} @var{systag} message |
c906108c SS |
2849 | @cindex thread identifier (system) |
2850 | @c FIXME-implementors!! It would be more helpful if the [New...] message | |
2851 | @c included GDB's numeric thread handle, so you could just go to that | |
2852 | @c thread without first checking `info threads'. | |
2853 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2854 | the target system's identification for the thread with a message in the | |
697aa1b7 | 2855 | form @samp{[New @var{systag}]}, where @var{systag} is a thread identifier |
c906108c | 2856 | whose form varies depending on the particular system. For example, on |
8807d78b | 2857 | @sc{gnu}/Linux, you might see |
c906108c | 2858 | |
474c8240 | 2859 | @smallexample |
08e796bc | 2860 | [New Thread 0x41e02940 (LWP 25582)] |
474c8240 | 2861 | @end smallexample |
c906108c SS |
2862 | |
2863 | @noindent | |
2864 | when @value{GDBN} notices a new thread. In contrast, on an SGI system, | |
2865 | the @var{systag} is simply something like @samp{process 368}, with no | |
2866 | further qualifier. | |
2867 | ||
2868 | @c FIXME!! (1) Does the [New...] message appear even for the very first | |
2869 | @c thread of a program, or does it only appear for the | |
6ca652b0 | 2870 | @c second---i.e.@: when it becomes obvious we have a multithread |
c906108c SS |
2871 | @c program? |
2872 | @c (2) *Is* there necessarily a first thread always? Or do some | |
2873 | @c multithread systems permit starting a program with multiple | |
5d161b24 | 2874 | @c threads ab initio? |
c906108c SS |
2875 | |
2876 | @cindex thread number | |
2877 | @cindex thread identifier (GDB) | |
2878 | For debugging purposes, @value{GDBN} associates its own thread | |
2879 | number---always a single integer---with each thread in your program. | |
2880 | ||
2881 | @table @code | |
2882 | @kindex info threads | |
60f98dde MS |
2883 | @item info threads @r{[}@var{id}@dots{}@r{]} |
2884 | Display a summary of all threads currently in your program. Optional | |
2885 | argument @var{id}@dots{} is one or more thread ids separated by spaces, and | |
2886 | means to print information only about the specified thread or threads. | |
2887 | @value{GDBN} displays for each thread (in this order): | |
c906108c SS |
2888 | |
2889 | @enumerate | |
09d4efe1 EZ |
2890 | @item |
2891 | the thread number assigned by @value{GDBN} | |
c906108c | 2892 | |
09d4efe1 EZ |
2893 | @item |
2894 | the target system's thread identifier (@var{systag}) | |
c906108c | 2895 | |
4694da01 TT |
2896 | @item |
2897 | the thread's name, if one is known. A thread can either be named by | |
2898 | the user (see @code{thread name}, below), or, in some cases, by the | |
2899 | program itself. | |
2900 | ||
09d4efe1 EZ |
2901 | @item |
2902 | the current stack frame summary for that thread | |
c906108c SS |
2903 | @end enumerate |
2904 | ||
2905 | @noindent | |
2906 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
2907 | indicates the current thread. | |
2908 | ||
5d161b24 | 2909 | For example, |
c906108c SS |
2910 | @end table |
2911 | @c end table here to get a little more width for example | |
2912 | ||
2913 | @smallexample | |
2914 | (@value{GDBP}) info threads | |
13fd8b81 TT |
2915 | Id Target Id Frame |
2916 | 3 process 35 thread 27 0x34e5 in sigpause () | |
2917 | 2 process 35 thread 23 0x34e5 in sigpause () | |
2918 | * 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) | |
c906108c SS |
2919 | at threadtest.c:68 |
2920 | @end smallexample | |
53a5351d | 2921 | |
c45da7e6 EZ |
2922 | On Solaris, you can display more information about user threads with a |
2923 | Solaris-specific command: | |
2924 | ||
2925 | @table @code | |
2926 | @item maint info sol-threads | |
2927 | @kindex maint info sol-threads | |
2928 | @cindex thread info (Solaris) | |
2929 | Display info on Solaris user threads. | |
2930 | @end table | |
2931 | ||
c906108c SS |
2932 | @table @code |
2933 | @kindex thread @var{threadno} | |
2934 | @item thread @var{threadno} | |
2935 | Make thread number @var{threadno} the current thread. The command | |
2936 | argument @var{threadno} is the internal @value{GDBN} thread number, as | |
2937 | shown in the first field of the @samp{info threads} display. | |
2938 | @value{GDBN} responds by displaying the system identifier of the thread | |
2939 | you selected, and its current stack frame summary: | |
2940 | ||
2941 | @smallexample | |
c906108c | 2942 | (@value{GDBP}) thread 2 |
13fd8b81 TT |
2943 | [Switching to thread 2 (Thread 0xb7fdab70 (LWP 12747))] |
2944 | #0 some_function (ignore=0x0) at example.c:8 | |
2945 | 8 printf ("hello\n"); | |
c906108c SS |
2946 | @end smallexample |
2947 | ||
2948 | @noindent | |
2949 | As with the @samp{[New @dots{}]} message, the form of the text after | |
2950 | @samp{Switching to} depends on your system's conventions for identifying | |
5d161b24 | 2951 | threads. |
c906108c | 2952 | |
6aed2dbc SS |
2953 | @vindex $_thread@r{, convenience variable} |
2954 | The debugger convenience variable @samp{$_thread} contains the number | |
2955 | of the current thread. You may find this useful in writing breakpoint | |
2956 | conditional expressions, command scripts, and so forth. See | |
2957 | @xref{Convenience Vars,, Convenience Variables}, for general | |
2958 | information on convenience variables. | |
2959 | ||
9c16f35a | 2960 | @kindex thread apply |
638ac427 | 2961 | @cindex apply command to several threads |
13fd8b81 | 2962 | @item thread apply [@var{threadno} | all] @var{command} |
839c27b7 EZ |
2963 | The @code{thread apply} command allows you to apply the named |
2964 | @var{command} to one or more threads. Specify the numbers of the | |
2965 | threads that you want affected with the command argument | |
2966 | @var{threadno}. It can be a single thread number, one of the numbers | |
2967 | shown in the first field of the @samp{info threads} display; or it | |
2968 | could be a range of thread numbers, as in @code{2-4}. To apply a | |
2969 | command to all threads, type @kbd{thread apply all @var{command}}. | |
93815fbf | 2970 | |
4694da01 TT |
2971 | @kindex thread name |
2972 | @cindex name a thread | |
2973 | @item thread name [@var{name}] | |
2974 | This command assigns a name to the current thread. If no argument is | |
2975 | given, any existing user-specified name is removed. The thread name | |
2976 | appears in the @samp{info threads} display. | |
2977 | ||
2978 | On some systems, such as @sc{gnu}/Linux, @value{GDBN} is able to | |
2979 | determine the name of the thread as given by the OS. On these | |
2980 | systems, a name specified with @samp{thread name} will override the | |
2981 | system-give name, and removing the user-specified name will cause | |
2982 | @value{GDBN} to once again display the system-specified name. | |
2983 | ||
60f98dde MS |
2984 | @kindex thread find |
2985 | @cindex search for a thread | |
2986 | @item thread find [@var{regexp}] | |
2987 | Search for and display thread ids whose name or @var{systag} | |
2988 | matches the supplied regular expression. | |
2989 | ||
2990 | As well as being the complement to the @samp{thread name} command, | |
2991 | this command also allows you to identify a thread by its target | |
2992 | @var{systag}. For instance, on @sc{gnu}/Linux, the target @var{systag} | |
2993 | is the LWP id. | |
2994 | ||
2995 | @smallexample | |
2996 | (@value{GDBN}) thread find 26688 | |
2997 | Thread 4 has target id 'Thread 0x41e02940 (LWP 26688)' | |
2998 | (@value{GDBN}) info thread 4 | |
2999 | Id Target Id Frame | |
3000 | 4 Thread 0x41e02940 (LWP 26688) 0x00000031ca6cd372 in select () | |
3001 | @end smallexample | |
3002 | ||
93815fbf VP |
3003 | @kindex set print thread-events |
3004 | @cindex print messages on thread start and exit | |
3005 | @item set print thread-events | |
3006 | @itemx set print thread-events on | |
3007 | @itemx set print thread-events off | |
3008 | The @code{set print thread-events} command allows you to enable or | |
3009 | disable printing of messages when @value{GDBN} notices that new threads have | |
3010 | started or that threads have exited. By default, these messages will | |
3011 | be printed if detection of these events is supported by the target. | |
3012 | Note that these messages cannot be disabled on all targets. | |
3013 | ||
3014 | @kindex show print thread-events | |
3015 | @item show print thread-events | |
3016 | Show whether messages will be printed when @value{GDBN} detects that threads | |
3017 | have started and exited. | |
c906108c SS |
3018 | @end table |
3019 | ||
79a6e687 | 3020 | @xref{Thread Stops,,Stopping and Starting Multi-thread Programs}, for |
c906108c SS |
3021 | more information about how @value{GDBN} behaves when you stop and start |
3022 | programs with multiple threads. | |
3023 | ||
79a6e687 | 3024 | @xref{Set Watchpoints,,Setting Watchpoints}, for information about |
c906108c | 3025 | watchpoints in programs with multiple threads. |
c906108c | 3026 | |
bf88dd68 | 3027 | @anchor{set libthread-db-search-path} |
17a37d48 PP |
3028 | @table @code |
3029 | @kindex set libthread-db-search-path | |
3030 | @cindex search path for @code{libthread_db} | |
3031 | @item set libthread-db-search-path @r{[}@var{path}@r{]} | |
3032 | If this variable is set, @var{path} is a colon-separated list of | |
3033 | directories @value{GDBN} will use to search for @code{libthread_db}. | |
3034 | If you omit @var{path}, @samp{libthread-db-search-path} will be reset to | |
98a5dd13 | 3035 | its default value (@code{$sdir:$pdir} on @sc{gnu}/Linux and Solaris systems). |
7e0396aa DE |
3036 | Internally, the default value comes from the @code{LIBTHREAD_DB_SEARCH_PATH} |
3037 | macro. | |
17a37d48 PP |
3038 | |
3039 | On @sc{gnu}/Linux and Solaris systems, @value{GDBN} uses a ``helper'' | |
3040 | @code{libthread_db} library to obtain information about threads in the | |
3041 | inferior process. @value{GDBN} will use @samp{libthread-db-search-path} | |
bf88dd68 JK |
3042 | to find @code{libthread_db}. @value{GDBN} also consults first if inferior |
3043 | specific thread debugging library loading is enabled | |
3044 | by @samp{set auto-load libthread-db} (@pxref{libthread_db.so.1 file}). | |
98a5dd13 DE |
3045 | |
3046 | A special entry @samp{$sdir} for @samp{libthread-db-search-path} | |
3047 | refers to the default system directories that are | |
bf88dd68 JK |
3048 | normally searched for loading shared libraries. The @samp{$sdir} entry |
3049 | is the only kind not needing to be enabled by @samp{set auto-load libthread-db} | |
3050 | (@pxref{libthread_db.so.1 file}). | |
98a5dd13 DE |
3051 | |
3052 | A special entry @samp{$pdir} for @samp{libthread-db-search-path} | |
3053 | refers to the directory from which @code{libpthread} | |
3054 | was loaded in the inferior process. | |
17a37d48 PP |
3055 | |
3056 | For any @code{libthread_db} library @value{GDBN} finds in above directories, | |
3057 | @value{GDBN} attempts to initialize it with the current inferior process. | |
3058 | If this initialization fails (which could happen because of a version | |
3059 | mismatch between @code{libthread_db} and @code{libpthread}), @value{GDBN} | |
3060 | will unload @code{libthread_db}, and continue with the next directory. | |
3061 | If none of @code{libthread_db} libraries initialize successfully, | |
3062 | @value{GDBN} will issue a warning and thread debugging will be disabled. | |
3063 | ||
3064 | Setting @code{libthread-db-search-path} is currently implemented | |
3065 | only on some platforms. | |
3066 | ||
3067 | @kindex show libthread-db-search-path | |
3068 | @item show libthread-db-search-path | |
3069 | Display current libthread_db search path. | |
02d868e8 PP |
3070 | |
3071 | @kindex set debug libthread-db | |
3072 | @kindex show debug libthread-db | |
3073 | @cindex debugging @code{libthread_db} | |
3074 | @item set debug libthread-db | |
3075 | @itemx show debug libthread-db | |
3076 | Turns on or off display of @code{libthread_db}-related events. | |
3077 | Use @code{1} to enable, @code{0} to disable. | |
17a37d48 PP |
3078 | @end table |
3079 | ||
6c95b8df PA |
3080 | @node Forks |
3081 | @section Debugging Forks | |
c906108c SS |
3082 | |
3083 | @cindex fork, debugging programs which call | |
3084 | @cindex multiple processes | |
3085 | @cindex processes, multiple | |
53a5351d JM |
3086 | On most systems, @value{GDBN} has no special support for debugging |
3087 | programs which create additional processes using the @code{fork} | |
3088 | function. When a program forks, @value{GDBN} will continue to debug the | |
3089 | parent process and the child process will run unimpeded. If you have | |
3090 | set a breakpoint in any code which the child then executes, the child | |
3091 | will get a @code{SIGTRAP} signal which (unless it catches the signal) | |
3092 | will cause it to terminate. | |
c906108c SS |
3093 | |
3094 | However, if you want to debug the child process there is a workaround | |
3095 | which isn't too painful. Put a call to @code{sleep} in the code which | |
3096 | the child process executes after the fork. It may be useful to sleep | |
3097 | only if a certain environment variable is set, or a certain file exists, | |
3098 | so that the delay need not occur when you don't want to run @value{GDBN} | |
3099 | on the child. While the child is sleeping, use the @code{ps} program to | |
3100 | get its process ID. Then tell @value{GDBN} (a new invocation of | |
3101 | @value{GDBN} if you are also debugging the parent process) to attach to | |
d4f3574e | 3102 | the child process (@pxref{Attach}). From that point on you can debug |
c906108c | 3103 | the child process just like any other process which you attached to. |
c906108c | 3104 | |
b51970ac DJ |
3105 | On some systems, @value{GDBN} provides support for debugging programs that |
3106 | create additional processes using the @code{fork} or @code{vfork} functions. | |
3107 | Currently, the only platforms with this feature are HP-UX (11.x and later | |
a6b151f1 | 3108 | only?) and @sc{gnu}/Linux (kernel version 2.5.60 and later). |
c906108c SS |
3109 | |
3110 | By default, when a program forks, @value{GDBN} will continue to debug | |
3111 | the parent process and the child process will run unimpeded. | |
3112 | ||
3113 | If you want to follow the child process instead of the parent process, | |
3114 | use the command @w{@code{set follow-fork-mode}}. | |
3115 | ||
3116 | @table @code | |
3117 | @kindex set follow-fork-mode | |
3118 | @item set follow-fork-mode @var{mode} | |
3119 | Set the debugger response to a program call of @code{fork} or | |
3120 | @code{vfork}. A call to @code{fork} or @code{vfork} creates a new | |
9c16f35a | 3121 | process. The @var{mode} argument can be: |
c906108c SS |
3122 | |
3123 | @table @code | |
3124 | @item parent | |
3125 | The original process is debugged after a fork. The child process runs | |
2df3850c | 3126 | unimpeded. This is the default. |
c906108c SS |
3127 | |
3128 | @item child | |
3129 | The new process is debugged after a fork. The parent process runs | |
3130 | unimpeded. | |
3131 | ||
c906108c SS |
3132 | @end table |
3133 | ||
9c16f35a | 3134 | @kindex show follow-fork-mode |
c906108c | 3135 | @item show follow-fork-mode |
2df3850c | 3136 | Display the current debugger response to a @code{fork} or @code{vfork} call. |
c906108c SS |
3137 | @end table |
3138 | ||
5c95884b MS |
3139 | @cindex debugging multiple processes |
3140 | On Linux, if you want to debug both the parent and child processes, use the | |
3141 | command @w{@code{set detach-on-fork}}. | |
3142 | ||
3143 | @table @code | |
3144 | @kindex set detach-on-fork | |
3145 | @item set detach-on-fork @var{mode} | |
3146 | Tells gdb whether to detach one of the processes after a fork, or | |
3147 | retain debugger control over them both. | |
3148 | ||
3149 | @table @code | |
3150 | @item on | |
3151 | The child process (or parent process, depending on the value of | |
3152 | @code{follow-fork-mode}) will be detached and allowed to run | |
3153 | independently. This is the default. | |
3154 | ||
3155 | @item off | |
3156 | Both processes will be held under the control of @value{GDBN}. | |
3157 | One process (child or parent, depending on the value of | |
3158 | @code{follow-fork-mode}) is debugged as usual, while the other | |
3159 | is held suspended. | |
3160 | ||
3161 | @end table | |
3162 | ||
11310833 NR |
3163 | @kindex show detach-on-fork |
3164 | @item show detach-on-fork | |
3165 | Show whether detach-on-fork mode is on/off. | |
5c95884b MS |
3166 | @end table |
3167 | ||
2277426b PA |
3168 | If you choose to set @samp{detach-on-fork} mode off, then @value{GDBN} |
3169 | will retain control of all forked processes (including nested forks). | |
3170 | You can list the forked processes under the control of @value{GDBN} by | |
3171 | using the @w{@code{info inferiors}} command, and switch from one fork | |
6c95b8df PA |
3172 | to another by using the @code{inferior} command (@pxref{Inferiors and |
3173 | Programs, ,Debugging Multiple Inferiors and Programs}). | |
5c95884b MS |
3174 | |
3175 | To quit debugging one of the forked processes, you can either detach | |
af624141 MS |
3176 | from it by using the @w{@code{detach inferiors}} command (allowing it |
3177 | to run independently), or kill it using the @w{@code{kill inferiors}} | |
6c95b8df PA |
3178 | command. @xref{Inferiors and Programs, ,Debugging Multiple Inferiors |
3179 | and Programs}. | |
5c95884b | 3180 | |
c906108c SS |
3181 | If you ask to debug a child process and a @code{vfork} is followed by an |
3182 | @code{exec}, @value{GDBN} executes the new target up to the first | |
3183 | breakpoint in the new target. If you have a breakpoint set on | |
3184 | @code{main} in your original program, the breakpoint will also be set on | |
3185 | the child process's @code{main}. | |
3186 | ||
2277426b PA |
3187 | On some systems, when a child process is spawned by @code{vfork}, you |
3188 | cannot debug the child or parent until an @code{exec} call completes. | |
c906108c SS |
3189 | |
3190 | If you issue a @code{run} command to @value{GDBN} after an @code{exec} | |
6c95b8df PA |
3191 | call executes, the new target restarts. To restart the parent |
3192 | process, use the @code{file} command with the parent executable name | |
3193 | as its argument. By default, after an @code{exec} call executes, | |
3194 | @value{GDBN} discards the symbols of the previous executable image. | |
3195 | You can change this behaviour with the @w{@code{set follow-exec-mode}} | |
3196 | command. | |
3197 | ||
3198 | @table @code | |
3199 | @kindex set follow-exec-mode | |
3200 | @item set follow-exec-mode @var{mode} | |
3201 | ||
3202 | Set debugger response to a program call of @code{exec}. An | |
3203 | @code{exec} call replaces the program image of a process. | |
3204 | ||
3205 | @code{follow-exec-mode} can be: | |
3206 | ||
3207 | @table @code | |
3208 | @item new | |
3209 | @value{GDBN} creates a new inferior and rebinds the process to this | |
3210 | new inferior. The program the process was running before the | |
3211 | @code{exec} call can be restarted afterwards by restarting the | |
3212 | original inferior. | |
3213 | ||
3214 | For example: | |
3215 | ||
3216 | @smallexample | |
3217 | (@value{GDBP}) info inferiors | |
3218 | (gdb) info inferior | |
3219 | Id Description Executable | |
3220 | * 1 <null> prog1 | |
3221 | (@value{GDBP}) run | |
3222 | process 12020 is executing new program: prog2 | |
3223 | Program exited normally. | |
3224 | (@value{GDBP}) info inferiors | |
3225 | Id Description Executable | |
3226 | * 2 <null> prog2 | |
3227 | 1 <null> prog1 | |
3228 | @end smallexample | |
3229 | ||
3230 | @item same | |
3231 | @value{GDBN} keeps the process bound to the same inferior. The new | |
3232 | executable image replaces the previous executable loaded in the | |
3233 | inferior. Restarting the inferior after the @code{exec} call, with | |
3234 | e.g., the @code{run} command, restarts the executable the process was | |
3235 | running after the @code{exec} call. This is the default mode. | |
3236 | ||
3237 | For example: | |
3238 | ||
3239 | @smallexample | |
3240 | (@value{GDBP}) info inferiors | |
3241 | Id Description Executable | |
3242 | * 1 <null> prog1 | |
3243 | (@value{GDBP}) run | |
3244 | process 12020 is executing new program: prog2 | |
3245 | Program exited normally. | |
3246 | (@value{GDBP}) info inferiors | |
3247 | Id Description Executable | |
3248 | * 1 <null> prog2 | |
3249 | @end smallexample | |
3250 | ||
3251 | @end table | |
3252 | @end table | |
c906108c SS |
3253 | |
3254 | You can use the @code{catch} command to make @value{GDBN} stop whenever | |
3255 | a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set | |
79a6e687 | 3256 | Catchpoints, ,Setting Catchpoints}. |
c906108c | 3257 | |
5c95884b | 3258 | @node Checkpoint/Restart |
79a6e687 | 3259 | @section Setting a @emph{Bookmark} to Return to Later |
5c95884b MS |
3260 | |
3261 | @cindex checkpoint | |
3262 | @cindex restart | |
3263 | @cindex bookmark | |
3264 | @cindex snapshot of a process | |
3265 | @cindex rewind program state | |
3266 | ||
3267 | On certain operating systems@footnote{Currently, only | |
3268 | @sc{gnu}/Linux.}, @value{GDBN} is able to save a @dfn{snapshot} of a | |
3269 | program's state, called a @dfn{checkpoint}, and come back to it | |
3270 | later. | |
3271 | ||
3272 | Returning to a checkpoint effectively undoes everything that has | |
3273 | happened in the program since the @code{checkpoint} was saved. This | |
3274 | includes changes in memory, registers, and even (within some limits) | |
3275 | system state. Effectively, it is like going back in time to the | |
3276 | moment when the checkpoint was saved. | |
3277 | ||
3278 | Thus, if you're stepping thru a program and you think you're | |
3279 | getting close to the point where things go wrong, you can save | |
3280 | a checkpoint. Then, if you accidentally go too far and miss | |
3281 | the critical statement, instead of having to restart your program | |
3282 | from the beginning, you can just go back to the checkpoint and | |
3283 | start again from there. | |
3284 | ||
3285 | This can be especially useful if it takes a lot of time or | |
3286 | steps to reach the point where you think the bug occurs. | |
3287 | ||
3288 | To use the @code{checkpoint}/@code{restart} method of debugging: | |
3289 | ||
3290 | @table @code | |
3291 | @kindex checkpoint | |
3292 | @item checkpoint | |
3293 | Save a snapshot of the debugged program's current execution state. | |
3294 | The @code{checkpoint} command takes no arguments, but each checkpoint | |
3295 | is assigned a small integer id, similar to a breakpoint id. | |
3296 | ||
3297 | @kindex info checkpoints | |
3298 | @item info checkpoints | |
3299 | List the checkpoints that have been saved in the current debugging | |
3300 | session. For each checkpoint, the following information will be | |
3301 | listed: | |
3302 | ||
3303 | @table @code | |
3304 | @item Checkpoint ID | |
3305 | @item Process ID | |
3306 | @item Code Address | |
3307 | @item Source line, or label | |
3308 | @end table | |
3309 | ||
3310 | @kindex restart @var{checkpoint-id} | |
3311 | @item restart @var{checkpoint-id} | |
3312 | Restore the program state that was saved as checkpoint number | |
3313 | @var{checkpoint-id}. All program variables, registers, stack frames | |
3314 | etc.@: will be returned to the values that they had when the checkpoint | |
3315 | was saved. In essence, gdb will ``wind back the clock'' to the point | |
3316 | in time when the checkpoint was saved. | |
3317 | ||
3318 | Note that breakpoints, @value{GDBN} variables, command history etc. | |
3319 | are not affected by restoring a checkpoint. In general, a checkpoint | |
3320 | only restores things that reside in the program being debugged, not in | |
3321 | the debugger. | |
3322 | ||
b8db102d MS |
3323 | @kindex delete checkpoint @var{checkpoint-id} |
3324 | @item delete checkpoint @var{checkpoint-id} | |
5c95884b MS |
3325 | Delete the previously-saved checkpoint identified by @var{checkpoint-id}. |
3326 | ||
3327 | @end table | |
3328 | ||
3329 | Returning to a previously saved checkpoint will restore the user state | |
3330 | of the program being debugged, plus a significant subset of the system | |
3331 | (OS) state, including file pointers. It won't ``un-write'' data from | |
3332 | a file, but it will rewind the file pointer to the previous location, | |
3333 | so that the previously written data can be overwritten. For files | |
3334 | opened in read mode, the pointer will also be restored so that the | |
3335 | previously read data can be read again. | |
3336 | ||
3337 | Of course, characters that have been sent to a printer (or other | |
3338 | external device) cannot be ``snatched back'', and characters received | |
3339 | from eg.@: a serial device can be removed from internal program buffers, | |
3340 | but they cannot be ``pushed back'' into the serial pipeline, ready to | |
3341 | be received again. Similarly, the actual contents of files that have | |
3342 | been changed cannot be restored (at this time). | |
3343 | ||
3344 | However, within those constraints, you actually can ``rewind'' your | |
3345 | program to a previously saved point in time, and begin debugging it | |
3346 | again --- and you can change the course of events so as to debug a | |
3347 | different execution path this time. | |
3348 | ||
3349 | @cindex checkpoints and process id | |
3350 | Finally, there is one bit of internal program state that will be | |
3351 | different when you return to a checkpoint --- the program's process | |
3352 | id. Each checkpoint will have a unique process id (or @var{pid}), | |
3353 | and each will be different from the program's original @var{pid}. | |
3354 | If your program has saved a local copy of its process id, this could | |
3355 | potentially pose a problem. | |
3356 | ||
79a6e687 | 3357 | @subsection A Non-obvious Benefit of Using Checkpoints |
5c95884b MS |
3358 | |
3359 | On some systems such as @sc{gnu}/Linux, address space randomization | |
3360 | is performed on new processes for security reasons. This makes it | |
3361 | difficult or impossible to set a breakpoint, or watchpoint, on an | |
3362 | absolute address if you have to restart the program, since the | |
3363 | absolute location of a symbol will change from one execution to the | |
3364 | next. | |
3365 | ||
3366 | A checkpoint, however, is an @emph{identical} copy of a process. | |
3367 | Therefore if you create a checkpoint at (eg.@:) the start of main, | |
3368 | and simply return to that checkpoint instead of restarting the | |
3369 | process, you can avoid the effects of address randomization and | |
3370 | your symbols will all stay in the same place. | |
3371 | ||
6d2ebf8b | 3372 | @node Stopping |
c906108c SS |
3373 | @chapter Stopping and Continuing |
3374 | ||
3375 | The principal purposes of using a debugger are so that you can stop your | |
3376 | program before it terminates; or so that, if your program runs into | |
3377 | trouble, you can investigate and find out why. | |
3378 | ||
7a292a7a SS |
3379 | Inside @value{GDBN}, your program may stop for any of several reasons, |
3380 | such as a signal, a breakpoint, or reaching a new line after a | |
3381 | @value{GDBN} command such as @code{step}. You may then examine and | |
3382 | change variables, set new breakpoints or remove old ones, and then | |
3383 | continue execution. Usually, the messages shown by @value{GDBN} provide | |
3384 | ample explanation of the status of your program---but you can also | |
3385 | explicitly request this information at any time. | |
c906108c SS |
3386 | |
3387 | @table @code | |
3388 | @kindex info program | |
3389 | @item info program | |
3390 | Display information about the status of your program: whether it is | |
7a292a7a | 3391 | running or not, what process it is, and why it stopped. |
c906108c SS |
3392 | @end table |
3393 | ||
3394 | @menu | |
3395 | * Breakpoints:: Breakpoints, watchpoints, and catchpoints | |
3396 | * Continuing and Stepping:: Resuming execution | |
aad1c02c TT |
3397 | * Skipping Over Functions and Files:: |
3398 | Skipping over functions and files | |
c906108c | 3399 | * Signals:: Signals |
c906108c | 3400 | * Thread Stops:: Stopping and starting multi-thread programs |
c906108c SS |
3401 | @end menu |
3402 | ||
6d2ebf8b | 3403 | @node Breakpoints |
79a6e687 | 3404 | @section Breakpoints, Watchpoints, and Catchpoints |
c906108c SS |
3405 | |
3406 | @cindex breakpoints | |
3407 | A @dfn{breakpoint} makes your program stop whenever a certain point in | |
3408 | the program is reached. For each breakpoint, you can add conditions to | |
3409 | control in finer detail whether your program stops. You can set | |
3410 | breakpoints with the @code{break} command and its variants (@pxref{Set | |
79a6e687 | 3411 | Breaks, ,Setting Breakpoints}), to specify the place where your program |
c906108c SS |
3412 | should stop by line number, function name or exact address in the |
3413 | program. | |
3414 | ||
09d4efe1 EZ |
3415 | On some systems, you can set breakpoints in shared libraries before |
3416 | the executable is run. There is a minor limitation on HP-UX systems: | |
3417 | you must wait until the executable is run in order to set breakpoints | |
3418 | in shared library routines that are not called directly by the program | |
3419 | (for example, routines that are arguments in a @code{pthread_create} | |
3420 | call). | |
c906108c SS |
3421 | |
3422 | @cindex watchpoints | |
fd60e0df | 3423 | @cindex data breakpoints |
c906108c SS |
3424 | @cindex memory tracing |
3425 | @cindex breakpoint on memory address | |
3426 | @cindex breakpoint on variable modification | |
3427 | A @dfn{watchpoint} is a special breakpoint that stops your program | |
fd60e0df | 3428 | when the value of an expression changes. The expression may be a value |
0ced0c34 | 3429 | of a variable, or it could involve values of one or more variables |
fd60e0df EZ |
3430 | combined by operators, such as @samp{a + b}. This is sometimes called |
3431 | @dfn{data breakpoints}. You must use a different command to set | |
79a6e687 | 3432 | watchpoints (@pxref{Set Watchpoints, ,Setting Watchpoints}), but aside |
fd60e0df EZ |
3433 | from that, you can manage a watchpoint like any other breakpoint: you |
3434 | enable, disable, and delete both breakpoints and watchpoints using the | |
3435 | same commands. | |
c906108c SS |
3436 | |
3437 | You can arrange to have values from your program displayed automatically | |
3438 | whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,, | |
79a6e687 | 3439 | Automatic Display}. |
c906108c SS |
3440 | |
3441 | @cindex catchpoints | |
3442 | @cindex breakpoint on events | |
3443 | A @dfn{catchpoint} is another special breakpoint that stops your program | |
b37052ae | 3444 | when a certain kind of event occurs, such as the throwing of a C@t{++} |
c906108c SS |
3445 | exception or the loading of a library. As with watchpoints, you use a |
3446 | different command to set a catchpoint (@pxref{Set Catchpoints, ,Setting | |
79a6e687 | 3447 | Catchpoints}), but aside from that, you can manage a catchpoint like any |
c906108c | 3448 | other breakpoint. (To stop when your program receives a signal, use the |
d4f3574e | 3449 | @code{handle} command; see @ref{Signals, ,Signals}.) |
c906108c SS |
3450 | |
3451 | @cindex breakpoint numbers | |
3452 | @cindex numbers for breakpoints | |
3453 | @value{GDBN} assigns a number to each breakpoint, watchpoint, or | |
3454 | catchpoint when you create it; these numbers are successive integers | |
3455 | starting with one. In many of the commands for controlling various | |
3456 | features of breakpoints you use the breakpoint number to say which | |
3457 | breakpoint you want to change. Each breakpoint may be @dfn{enabled} or | |
3458 | @dfn{disabled}; if disabled, it has no effect on your program until you | |
3459 | enable it again. | |
3460 | ||
c5394b80 JM |
3461 | @cindex breakpoint ranges |
3462 | @cindex ranges of breakpoints | |
3463 | Some @value{GDBN} commands accept a range of breakpoints on which to | |
3464 | operate. A breakpoint range is either a single breakpoint number, like | |
3465 | @samp{5}, or two such numbers, in increasing order, separated by a | |
3466 | hyphen, like @samp{5-7}. When a breakpoint range is given to a command, | |
d52fb0e9 | 3467 | all breakpoints in that range are operated on. |
c5394b80 | 3468 | |
c906108c SS |
3469 | @menu |
3470 | * Set Breaks:: Setting breakpoints | |
3471 | * Set Watchpoints:: Setting watchpoints | |
3472 | * Set Catchpoints:: Setting catchpoints | |
3473 | * Delete Breaks:: Deleting breakpoints | |
3474 | * Disabling:: Disabling breakpoints | |
3475 | * Conditions:: Break conditions | |
3476 | * Break Commands:: Breakpoint command lists | |
e7e0cddf | 3477 | * Dynamic Printf:: Dynamic printf |
6149aea9 | 3478 | * Save Breakpoints:: How to save breakpoints in a file |
62e5f89c | 3479 | * Static Probe Points:: Listing static probe points |
d4f3574e | 3480 | * Error in Breakpoints:: ``Cannot insert breakpoints'' |
79a6e687 | 3481 | * Breakpoint-related Warnings:: ``Breakpoint address adjusted...'' |
c906108c SS |
3482 | @end menu |
3483 | ||
6d2ebf8b | 3484 | @node Set Breaks |
79a6e687 | 3485 | @subsection Setting Breakpoints |
c906108c | 3486 | |
5d161b24 | 3487 | @c FIXME LMB what does GDB do if no code on line of breakpt? |
c906108c SS |
3488 | @c consider in particular declaration with/without initialization. |
3489 | @c | |
3490 | @c FIXME 2 is there stuff on this already? break at fun start, already init? | |
3491 | ||
3492 | @kindex break | |
41afff9a EZ |
3493 | @kindex b @r{(@code{break})} |
3494 | @vindex $bpnum@r{, convenience variable} | |
c906108c SS |
3495 | @cindex latest breakpoint |
3496 | Breakpoints are set with the @code{break} command (abbreviated | |
5d161b24 | 3497 | @code{b}). The debugger convenience variable @samp{$bpnum} records the |
f3b28801 | 3498 | number of the breakpoint you've set most recently; see @ref{Convenience |
79a6e687 | 3499 | Vars,, Convenience Variables}, for a discussion of what you can do with |
c906108c SS |
3500 | convenience variables. |
3501 | ||
c906108c | 3502 | @table @code |
2a25a5ba EZ |
3503 | @item break @var{location} |
3504 | Set a breakpoint at the given @var{location}, which can specify a | |
3505 | function name, a line number, or an address of an instruction. | |
3506 | (@xref{Specify Location}, for a list of all the possible ways to | |
3507 | specify a @var{location}.) The breakpoint will stop your program just | |
3508 | before it executes any of the code in the specified @var{location}. | |
3509 | ||
c906108c | 3510 | When using source languages that permit overloading of symbols, such as |
2a25a5ba | 3511 | C@t{++}, a function name may refer to more than one possible place to break. |
6ba66d6a JB |
3512 | @xref{Ambiguous Expressions,,Ambiguous Expressions}, for a discussion of |
3513 | that situation. | |
c906108c | 3514 | |
45ac276d | 3515 | It is also possible to insert a breakpoint that will stop the program |
2c88c651 JB |
3516 | only if a specific thread (@pxref{Thread-Specific Breakpoints}) |
3517 | or a specific task (@pxref{Ada Tasks}) hits that breakpoint. | |
45ac276d | 3518 | |
c906108c SS |
3519 | @item break |
3520 | When called without any arguments, @code{break} sets a breakpoint at | |
3521 | the next instruction to be executed in the selected stack frame | |
3522 | (@pxref{Stack, ,Examining the Stack}). In any selected frame but the | |
3523 | innermost, this makes your program stop as soon as control | |
3524 | returns to that frame. This is similar to the effect of a | |
3525 | @code{finish} command in the frame inside the selected frame---except | |
3526 | that @code{finish} does not leave an active breakpoint. If you use | |
3527 | @code{break} without an argument in the innermost frame, @value{GDBN} stops | |
3528 | the next time it reaches the current location; this may be useful | |
3529 | inside loops. | |
3530 | ||
3531 | @value{GDBN} normally ignores breakpoints when it resumes execution, until at | |
3532 | least one instruction has been executed. If it did not do this, you | |
3533 | would be unable to proceed past a breakpoint without first disabling the | |
3534 | breakpoint. This rule applies whether or not the breakpoint already | |
3535 | existed when your program stopped. | |
3536 | ||
3537 | @item break @dots{} if @var{cond} | |
3538 | Set a breakpoint with condition @var{cond}; evaluate the expression | |
3539 | @var{cond} each time the breakpoint is reached, and stop only if the | |
3540 | value is nonzero---that is, if @var{cond} evaluates as true. | |
3541 | @samp{@dots{}} stands for one of the possible arguments described | |
3542 | above (or no argument) specifying where to break. @xref{Conditions, | |
79a6e687 | 3543 | ,Break Conditions}, for more information on breakpoint conditions. |
c906108c SS |
3544 | |
3545 | @kindex tbreak | |
3546 | @item tbreak @var{args} | |
697aa1b7 | 3547 | Set a breakpoint enabled only for one stop. The @var{args} are the |
c906108c SS |
3548 | same as for the @code{break} command, and the breakpoint is set in the same |
3549 | way, but the breakpoint is automatically deleted after the first time your | |
79a6e687 | 3550 | program stops there. @xref{Disabling, ,Disabling Breakpoints}. |
c906108c | 3551 | |
c906108c | 3552 | @kindex hbreak |
ba04e063 | 3553 | @cindex hardware breakpoints |
c906108c | 3554 | @item hbreak @var{args} |
697aa1b7 | 3555 | Set a hardware-assisted breakpoint. The @var{args} are the same as for the |
d4f3574e | 3556 | @code{break} command and the breakpoint is set in the same way, but the |
c906108c SS |
3557 | breakpoint requires hardware support and some target hardware may not |
3558 | have this support. The main purpose of this is EPROM/ROM code | |
d4f3574e SS |
3559 | debugging, so you can set a breakpoint at an instruction without |
3560 | changing the instruction. This can be used with the new trap-generation | |
09d4efe1 | 3561 | provided by SPARClite DSU and most x86-based targets. These targets |
d4f3574e SS |
3562 | will generate traps when a program accesses some data or instruction |
3563 | address that is assigned to the debug registers. However the hardware | |
3564 | breakpoint registers can take a limited number of breakpoints. For | |
3565 | example, on the DSU, only two data breakpoints can be set at a time, and | |
3566 | @value{GDBN} will reject this command if more than two are used. Delete | |
3567 | or disable unused hardware breakpoints before setting new ones | |
79a6e687 BW |
3568 | (@pxref{Disabling, ,Disabling Breakpoints}). |
3569 | @xref{Conditions, ,Break Conditions}. | |
9c16f35a EZ |
3570 | For remote targets, you can restrict the number of hardware |
3571 | breakpoints @value{GDBN} will use, see @ref{set remote | |
3572 | hardware-breakpoint-limit}. | |
501eef12 | 3573 | |
c906108c SS |
3574 | @kindex thbreak |
3575 | @item thbreak @var{args} | |
697aa1b7 | 3576 | Set a hardware-assisted breakpoint enabled only for one stop. The @var{args} |
c906108c | 3577 | are the same as for the @code{hbreak} command and the breakpoint is set in |
5d161b24 | 3578 | the same way. However, like the @code{tbreak} command, |
c906108c SS |
3579 | the breakpoint is automatically deleted after the |
3580 | first time your program stops there. Also, like the @code{hbreak} | |
5d161b24 | 3581 | command, the breakpoint requires hardware support and some target hardware |
79a6e687 BW |
3582 | may not have this support. @xref{Disabling, ,Disabling Breakpoints}. |
3583 | See also @ref{Conditions, ,Break Conditions}. | |
c906108c SS |
3584 | |
3585 | @kindex rbreak | |
3586 | @cindex regular expression | |
8bd10a10 | 3587 | @cindex breakpoints at functions matching a regexp |
c45da7e6 | 3588 | @cindex set breakpoints in many functions |
c906108c | 3589 | @item rbreak @var{regex} |
c906108c | 3590 | Set breakpoints on all functions matching the regular expression |
11cf8741 JM |
3591 | @var{regex}. This command sets an unconditional breakpoint on all |
3592 | matches, printing a list of all breakpoints it set. Once these | |
3593 | breakpoints are set, they are treated just like the breakpoints set with | |
3594 | the @code{break} command. You can delete them, disable them, or make | |
3595 | them conditional the same way as any other breakpoint. | |
3596 | ||
3597 | The syntax of the regular expression is the standard one used with tools | |
3598 | like @file{grep}. Note that this is different from the syntax used by | |
3599 | shells, so for instance @code{foo*} matches all functions that include | |
3600 | an @code{fo} followed by zero or more @code{o}s. There is an implicit | |
3601 | @code{.*} leading and trailing the regular expression you supply, so to | |
3602 | match only functions that begin with @code{foo}, use @code{^foo}. | |
c906108c | 3603 | |
f7dc1244 | 3604 | @cindex non-member C@t{++} functions, set breakpoint in |
b37052ae | 3605 | When debugging C@t{++} programs, @code{rbreak} is useful for setting |
c906108c SS |
3606 | breakpoints on overloaded functions that are not members of any special |
3607 | classes. | |
c906108c | 3608 | |
f7dc1244 EZ |
3609 | @cindex set breakpoints on all functions |
3610 | The @code{rbreak} command can be used to set breakpoints in | |
3611 | @strong{all} the functions in a program, like this: | |
3612 | ||
3613 | @smallexample | |
3614 | (@value{GDBP}) rbreak . | |
3615 | @end smallexample | |
3616 | ||
8bd10a10 CM |
3617 | @item rbreak @var{file}:@var{regex} |
3618 | If @code{rbreak} is called with a filename qualification, it limits | |
3619 | the search for functions matching the given regular expression to the | |
3620 | specified @var{file}. This can be used, for example, to set breakpoints on | |
3621 | every function in a given file: | |
3622 | ||
3623 | @smallexample | |
3624 | (@value{GDBP}) rbreak file.c:. | |
3625 | @end smallexample | |
3626 | ||
3627 | The colon separating the filename qualifier from the regex may | |
3628 | optionally be surrounded by spaces. | |
3629 | ||
c906108c SS |
3630 | @kindex info breakpoints |
3631 | @cindex @code{$_} and @code{info breakpoints} | |
e5a67952 MS |
3632 | @item info breakpoints @r{[}@var{n}@dots{}@r{]} |
3633 | @itemx info break @r{[}@var{n}@dots{}@r{]} | |
c906108c | 3634 | Print a table of all breakpoints, watchpoints, and catchpoints set and |
45ac1734 | 3635 | not deleted. Optional argument @var{n} means print information only |
e5a67952 MS |
3636 | about the specified breakpoint(s) (or watchpoint(s) or catchpoint(s)). |
3637 | For each breakpoint, following columns are printed: | |
c906108c SS |
3638 | |
3639 | @table @emph | |
3640 | @item Breakpoint Numbers | |
3641 | @item Type | |
3642 | Breakpoint, watchpoint, or catchpoint. | |
3643 | @item Disposition | |
3644 | Whether the breakpoint is marked to be disabled or deleted when hit. | |
3645 | @item Enabled or Disabled | |
3646 | Enabled breakpoints are marked with @samp{y}. @samp{n} marks breakpoints | |
b3db7447 | 3647 | that are not enabled. |
c906108c | 3648 | @item Address |
fe6fbf8b | 3649 | Where the breakpoint is in your program, as a memory address. For a |
b3db7447 NR |
3650 | pending breakpoint whose address is not yet known, this field will |
3651 | contain @samp{<PENDING>}. Such breakpoint won't fire until a shared | |
3652 | library that has the symbol or line referred by breakpoint is loaded. | |
3653 | See below for details. A breakpoint with several locations will | |
3b784c4f | 3654 | have @samp{<MULTIPLE>} in this field---see below for details. |
c906108c SS |
3655 | @item What |
3656 | Where the breakpoint is in the source for your program, as a file and | |
2650777c JJ |
3657 | line number. For a pending breakpoint, the original string passed to |
3658 | the breakpoint command will be listed as it cannot be resolved until | |
3659 | the appropriate shared library is loaded in the future. | |
c906108c SS |
3660 | @end table |
3661 | ||
3662 | @noindent | |
83364271 LM |
3663 | If a breakpoint is conditional, there are two evaluation modes: ``host'' and |
3664 | ``target''. If mode is ``host'', breakpoint condition evaluation is done by | |
3665 | @value{GDBN} on the host's side. If it is ``target'', then the condition | |
3666 | is evaluated by the target. The @code{info break} command shows | |
3667 | the condition on the line following the affected breakpoint, together with | |
3668 | its condition evaluation mode in between parentheses. | |
3669 | ||
3670 | Breakpoint commands, if any, are listed after that. A pending breakpoint is | |
3671 | allowed to have a condition specified for it. The condition is not parsed for | |
3672 | validity until a shared library is loaded that allows the pending | |
3673 | breakpoint to resolve to a valid location. | |
c906108c SS |
3674 | |
3675 | @noindent | |
3676 | @code{info break} with a breakpoint | |
3677 | number @var{n} as argument lists only that breakpoint. The | |
3678 | convenience variable @code{$_} and the default examining-address for | |
3679 | the @code{x} command are set to the address of the last breakpoint | |
79a6e687 | 3680 | listed (@pxref{Memory, ,Examining Memory}). |
c906108c SS |
3681 | |
3682 | @noindent | |
3683 | @code{info break} displays a count of the number of times the breakpoint | |
3684 | has been hit. This is especially useful in conjunction with the | |
3685 | @code{ignore} command. You can ignore a large number of breakpoint | |
3686 | hits, look at the breakpoint info to see how many times the breakpoint | |
3687 | was hit, and then run again, ignoring one less than that number. This | |
3688 | will get you quickly to the last hit of that breakpoint. | |
816338b5 SS |
3689 | |
3690 | @noindent | |
3691 | For a breakpoints with an enable count (xref) greater than 1, | |
3692 | @code{info break} also displays that count. | |
3693 | ||
c906108c SS |
3694 | @end table |
3695 | ||
3696 | @value{GDBN} allows you to set any number of breakpoints at the same place in | |
3697 | your program. There is nothing silly or meaningless about this. When | |
3698 | the breakpoints are conditional, this is even useful | |
79a6e687 | 3699 | (@pxref{Conditions, ,Break Conditions}). |
c906108c | 3700 | |
2e9132cc EZ |
3701 | @cindex multiple locations, breakpoints |
3702 | @cindex breakpoints, multiple locations | |
fcda367b | 3703 | It is possible that a breakpoint corresponds to several locations |
fe6fbf8b VP |
3704 | in your program. Examples of this situation are: |
3705 | ||
3706 | @itemize @bullet | |
f8eba3c6 TT |
3707 | @item |
3708 | Multiple functions in the program may have the same name. | |
3709 | ||
fe6fbf8b VP |
3710 | @item |
3711 | For a C@t{++} constructor, the @value{NGCC} compiler generates several | |
3712 | instances of the function body, used in different cases. | |
3713 | ||
3714 | @item | |
3715 | For a C@t{++} template function, a given line in the function can | |
3716 | correspond to any number of instantiations. | |
3717 | ||
3718 | @item | |
3719 | For an inlined function, a given source line can correspond to | |
3720 | several places where that function is inlined. | |
fe6fbf8b VP |
3721 | @end itemize |
3722 | ||
3723 | In all those cases, @value{GDBN} will insert a breakpoint at all | |
f8eba3c6 | 3724 | the relevant locations. |
fe6fbf8b | 3725 | |
3b784c4f EZ |
3726 | A breakpoint with multiple locations is displayed in the breakpoint |
3727 | table using several rows---one header row, followed by one row for | |
3728 | each breakpoint location. The header row has @samp{<MULTIPLE>} in the | |
3729 | address column. The rows for individual locations contain the actual | |
3730 | addresses for locations, and show the functions to which those | |
3731 | locations belong. The number column for a location is of the form | |
fe6fbf8b VP |
3732 | @var{breakpoint-number}.@var{location-number}. |
3733 | ||
3734 | For example: | |
3b784c4f | 3735 | |
fe6fbf8b VP |
3736 | @smallexample |
3737 | Num Type Disp Enb Address What | |
3738 | 1 breakpoint keep y <MULTIPLE> | |
3739 | stop only if i==1 | |
3740 | breakpoint already hit 1 time | |
3741 | 1.1 y 0x080486a2 in void foo<int>() at t.cc:8 | |
3742 | 1.2 y 0x080486ca in void foo<double>() at t.cc:8 | |
3743 | @end smallexample | |
3744 | ||
3745 | Each location can be individually enabled or disabled by passing | |
3746 | @var{breakpoint-number}.@var{location-number} as argument to the | |
3b784c4f EZ |
3747 | @code{enable} and @code{disable} commands. Note that you cannot |
3748 | delete the individual locations from the list, you can only delete the | |
16bfc218 | 3749 | entire list of locations that belong to their parent breakpoint (with |
3b784c4f EZ |
3750 | the @kbd{delete @var{num}} command, where @var{num} is the number of |
3751 | the parent breakpoint, 1 in the above example). Disabling or enabling | |
3752 | the parent breakpoint (@pxref{Disabling}) affects all of the locations | |
3753 | that belong to that breakpoint. | |
fe6fbf8b | 3754 | |
2650777c | 3755 | @cindex pending breakpoints |
fe6fbf8b | 3756 | It's quite common to have a breakpoint inside a shared library. |
3b784c4f | 3757 | Shared libraries can be loaded and unloaded explicitly, |
fe6fbf8b VP |
3758 | and possibly repeatedly, as the program is executed. To support |
3759 | this use case, @value{GDBN} updates breakpoint locations whenever | |
3760 | any shared library is loaded or unloaded. Typically, you would | |
fcda367b | 3761 | set a breakpoint in a shared library at the beginning of your |
fe6fbf8b VP |
3762 | debugging session, when the library is not loaded, and when the |
3763 | symbols from the library are not available. When you try to set | |
3764 | breakpoint, @value{GDBN} will ask you if you want to set | |
3b784c4f | 3765 | a so called @dfn{pending breakpoint}---breakpoint whose address |
fe6fbf8b VP |
3766 | is not yet resolved. |
3767 | ||
3768 | After the program is run, whenever a new shared library is loaded, | |
3769 | @value{GDBN} reevaluates all the breakpoints. When a newly loaded | |
3770 | shared library contains the symbol or line referred to by some | |
3771 | pending breakpoint, that breakpoint is resolved and becomes an | |
3772 | ordinary breakpoint. When a library is unloaded, all breakpoints | |
3773 | that refer to its symbols or source lines become pending again. | |
3774 | ||
3775 | This logic works for breakpoints with multiple locations, too. For | |
3776 | example, if you have a breakpoint in a C@t{++} template function, and | |
3777 | a newly loaded shared library has an instantiation of that template, | |
3778 | a new location is added to the list of locations for the breakpoint. | |
3779 | ||
3780 | Except for having unresolved address, pending breakpoints do not | |
3781 | differ from regular breakpoints. You can set conditions or commands, | |
3782 | enable and disable them and perform other breakpoint operations. | |
3783 | ||
3784 | @value{GDBN} provides some additional commands for controlling what | |
3785 | happens when the @samp{break} command cannot resolve breakpoint | |
3786 | address specification to an address: | |
dd79a6cf JJ |
3787 | |
3788 | @kindex set breakpoint pending | |
3789 | @kindex show breakpoint pending | |
3790 | @table @code | |
3791 | @item set breakpoint pending auto | |
3792 | This is the default behavior. When @value{GDBN} cannot find the breakpoint | |
3793 | location, it queries you whether a pending breakpoint should be created. | |
3794 | ||
3795 | @item set breakpoint pending on | |
3796 | This indicates that an unrecognized breakpoint location should automatically | |
3797 | result in a pending breakpoint being created. | |
3798 | ||
3799 | @item set breakpoint pending off | |
3800 | This indicates that pending breakpoints are not to be created. Any | |
3801 | unrecognized breakpoint location results in an error. This setting does | |
3802 | not affect any pending breakpoints previously created. | |
3803 | ||
3804 | @item show breakpoint pending | |
3805 | Show the current behavior setting for creating pending breakpoints. | |
3806 | @end table | |
2650777c | 3807 | |
fe6fbf8b VP |
3808 | The settings above only affect the @code{break} command and its |
3809 | variants. Once breakpoint is set, it will be automatically updated | |
3810 | as shared libraries are loaded and unloaded. | |
2650777c | 3811 | |
765dc015 VP |
3812 | @cindex automatic hardware breakpoints |
3813 | For some targets, @value{GDBN} can automatically decide if hardware or | |
3814 | software breakpoints should be used, depending on whether the | |
3815 | breakpoint address is read-only or read-write. This applies to | |
3816 | breakpoints set with the @code{break} command as well as to internal | |
3817 | breakpoints set by commands like @code{next} and @code{finish}. For | |
fcda367b | 3818 | breakpoints set with @code{hbreak}, @value{GDBN} will always use hardware |
765dc015 VP |
3819 | breakpoints. |
3820 | ||
3821 | You can control this automatic behaviour with the following commands:: | |
3822 | ||
3823 | @kindex set breakpoint auto-hw | |
3824 | @kindex show breakpoint auto-hw | |
3825 | @table @code | |
3826 | @item set breakpoint auto-hw on | |
3827 | This is the default behavior. When @value{GDBN} sets a breakpoint, it | |
3828 | will try to use the target memory map to decide if software or hardware | |
3829 | breakpoint must be used. | |
3830 | ||
3831 | @item set breakpoint auto-hw off | |
3832 | This indicates @value{GDBN} should not automatically select breakpoint | |
3833 | type. If the target provides a memory map, @value{GDBN} will warn when | |
3834 | trying to set software breakpoint at a read-only address. | |
3835 | @end table | |
3836 | ||
74960c60 VP |
3837 | @value{GDBN} normally implements breakpoints by replacing the program code |
3838 | at the breakpoint address with a special instruction, which, when | |
3839 | executed, given control to the debugger. By default, the program | |
3840 | code is so modified only when the program is resumed. As soon as | |
3841 | the program stops, @value{GDBN} restores the original instructions. This | |
3842 | behaviour guards against leaving breakpoints inserted in the | |
3843 | target should gdb abrubptly disconnect. However, with slow remote | |
3844 | targets, inserting and removing breakpoint can reduce the performance. | |
3845 | This behavior can be controlled with the following commands:: | |
3846 | ||
3847 | @kindex set breakpoint always-inserted | |
3848 | @kindex show breakpoint always-inserted | |
3849 | @table @code | |
3850 | @item set breakpoint always-inserted off | |
33e5cbd6 PA |
3851 | All breakpoints, including newly added by the user, are inserted in |
3852 | the target only when the target is resumed. All breakpoints are | |
a25a5a45 | 3853 | removed from the target when it stops. This is the default mode. |
74960c60 VP |
3854 | |
3855 | @item set breakpoint always-inserted on | |
3856 | Causes all breakpoints to be inserted in the target at all times. If | |
3857 | the user adds a new breakpoint, or changes an existing breakpoint, the | |
3858 | breakpoints in the target are updated immediately. A breakpoint is | |
a25a5a45 | 3859 | removed from the target only when breakpoint itself is deleted. |
765dc015 | 3860 | |
83364271 LM |
3861 | @value{GDBN} handles conditional breakpoints by evaluating these conditions |
3862 | when a breakpoint breaks. If the condition is true, then the process being | |
3863 | debugged stops, otherwise the process is resumed. | |
3864 | ||
3865 | If the target supports evaluating conditions on its end, @value{GDBN} may | |
3866 | download the breakpoint, together with its conditions, to it. | |
3867 | ||
3868 | This feature can be controlled via the following commands: | |
3869 | ||
3870 | @kindex set breakpoint condition-evaluation | |
3871 | @kindex show breakpoint condition-evaluation | |
3872 | @table @code | |
3873 | @item set breakpoint condition-evaluation host | |
3874 | This option commands @value{GDBN} to evaluate the breakpoint | |
3875 | conditions on the host's side. Unconditional breakpoints are sent to | |
3876 | the target which in turn receives the triggers and reports them back to GDB | |
3877 | for condition evaluation. This is the standard evaluation mode. | |
3878 | ||
3879 | @item set breakpoint condition-evaluation target | |
3880 | This option commands @value{GDBN} to download breakpoint conditions | |
3881 | to the target at the moment of their insertion. The target | |
3882 | is responsible for evaluating the conditional expression and reporting | |
3883 | breakpoint stop events back to @value{GDBN} whenever the condition | |
3884 | is true. Due to limitations of target-side evaluation, some conditions | |
3885 | cannot be evaluated there, e.g., conditions that depend on local data | |
3886 | that is only known to the host. Examples include | |
3887 | conditional expressions involving convenience variables, complex types | |
3888 | that cannot be handled by the agent expression parser and expressions | |
3889 | that are too long to be sent over to the target, specially when the | |
3890 | target is a remote system. In these cases, the conditions will be | |
3891 | evaluated by @value{GDBN}. | |
3892 | ||
3893 | @item set breakpoint condition-evaluation auto | |
3894 | This is the default mode. If the target supports evaluating breakpoint | |
3895 | conditions on its end, @value{GDBN} will download breakpoint conditions to | |
3896 | the target (limitations mentioned previously apply). If the target does | |
3897 | not support breakpoint condition evaluation, then @value{GDBN} will fallback | |
3898 | to evaluating all these conditions on the host's side. | |
3899 | @end table | |
3900 | ||
3901 | ||
c906108c SS |
3902 | @cindex negative breakpoint numbers |
3903 | @cindex internal @value{GDBN} breakpoints | |
eb12ee30 AC |
3904 | @value{GDBN} itself sometimes sets breakpoints in your program for |
3905 | special purposes, such as proper handling of @code{longjmp} (in C | |
3906 | programs). These internal breakpoints are assigned negative numbers, | |
3907 | starting with @code{-1}; @samp{info breakpoints} does not display them. | |
c906108c | 3908 | You can see these breakpoints with the @value{GDBN} maintenance command |
eb12ee30 | 3909 | @samp{maint info breakpoints} (@pxref{maint info breakpoints}). |
c906108c SS |
3910 | |
3911 | ||
6d2ebf8b | 3912 | @node Set Watchpoints |
79a6e687 | 3913 | @subsection Setting Watchpoints |
c906108c SS |
3914 | |
3915 | @cindex setting watchpoints | |
c906108c SS |
3916 | You can use a watchpoint to stop execution whenever the value of an |
3917 | expression changes, without having to predict a particular place where | |
fd60e0df EZ |
3918 | this may happen. (This is sometimes called a @dfn{data breakpoint}.) |
3919 | The expression may be as simple as the value of a single variable, or | |
3920 | as complex as many variables combined by operators. Examples include: | |
3921 | ||
3922 | @itemize @bullet | |
3923 | @item | |
3924 | A reference to the value of a single variable. | |
3925 | ||
3926 | @item | |
3927 | An address cast to an appropriate data type. For example, | |
3928 | @samp{*(int *)0x12345678} will watch a 4-byte region at the specified | |
3929 | address (assuming an @code{int} occupies 4 bytes). | |
3930 | ||
3931 | @item | |
3932 | An arbitrarily complex expression, such as @samp{a*b + c/d}. The | |
3933 | expression can use any operators valid in the program's native | |
3934 | language (@pxref{Languages}). | |
3935 | @end itemize | |
c906108c | 3936 | |
fa4727a6 DJ |
3937 | You can set a watchpoint on an expression even if the expression can |
3938 | not be evaluated yet. For instance, you can set a watchpoint on | |
3939 | @samp{*global_ptr} before @samp{global_ptr} is initialized. | |
3940 | @value{GDBN} will stop when your program sets @samp{global_ptr} and | |
3941 | the expression produces a valid value. If the expression becomes | |
3942 | valid in some other way than changing a variable (e.g.@: if the memory | |
3943 | pointed to by @samp{*global_ptr} becomes readable as the result of a | |
3944 | @code{malloc} call), @value{GDBN} may not stop until the next time | |
3945 | the expression changes. | |
3946 | ||
82f2d802 EZ |
3947 | @cindex software watchpoints |
3948 | @cindex hardware watchpoints | |
c906108c | 3949 | Depending on your system, watchpoints may be implemented in software or |
2df3850c | 3950 | hardware. @value{GDBN} does software watchpointing by single-stepping your |
c906108c SS |
3951 | program and testing the variable's value each time, which is hundreds of |
3952 | times slower than normal execution. (But this may still be worth it, to | |
3953 | catch errors where you have no clue what part of your program is the | |
3954 | culprit.) | |
3955 | ||
37e4754d | 3956 | On some systems, such as HP-UX, PowerPC, @sc{gnu}/Linux and most other |
82f2d802 EZ |
3957 | x86-based targets, @value{GDBN} includes support for hardware |
3958 | watchpoints, which do not slow down the running of your program. | |
c906108c SS |
3959 | |
3960 | @table @code | |
3961 | @kindex watch | |
9c06b0b4 | 3962 | @item watch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} @r{[}mask @var{maskvalue}@r{]} |
fd60e0df EZ |
3963 | Set a watchpoint for an expression. @value{GDBN} will break when the |
3964 | expression @var{expr} is written into by the program and its value | |
3965 | changes. The simplest (and the most popular) use of this command is | |
3966 | to watch the value of a single variable: | |
3967 | ||
3968 | @smallexample | |
3969 | (@value{GDBP}) watch foo | |
3970 | @end smallexample | |
c906108c | 3971 | |
d8b2a693 | 3972 | If the command includes a @code{@r{[}thread @var{threadnum}@r{]}} |
9c06b0b4 | 3973 | argument, @value{GDBN} breaks only when the thread identified by |
d8b2a693 JB |
3974 | @var{threadnum} changes the value of @var{expr}. If any other threads |
3975 | change the value of @var{expr}, @value{GDBN} will not break. Note | |
3976 | that watchpoints restricted to a single thread in this way only work | |
3977 | with Hardware Watchpoints. | |
3978 | ||
06a64a0b TT |
3979 | Ordinarily a watchpoint respects the scope of variables in @var{expr} |
3980 | (see below). The @code{-location} argument tells @value{GDBN} to | |
3981 | instead watch the memory referred to by @var{expr}. In this case, | |
3982 | @value{GDBN} will evaluate @var{expr}, take the address of the result, | |
3983 | and watch the memory at that address. The type of the result is used | |
3984 | to determine the size of the watched memory. If the expression's | |
3985 | result does not have an address, then @value{GDBN} will print an | |
3986 | error. | |
3987 | ||
9c06b0b4 TJB |
3988 | The @code{@r{[}mask @var{maskvalue}@r{]}} argument allows creation |
3989 | of masked watchpoints, if the current architecture supports this | |
3990 | feature (e.g., PowerPC Embedded architecture, see @ref{PowerPC | |
3991 | Embedded}.) A @dfn{masked watchpoint} specifies a mask in addition | |
3992 | to an address to watch. The mask specifies that some bits of an address | |
3993 | (the bits which are reset in the mask) should be ignored when matching | |
3994 | the address accessed by the inferior against the watchpoint address. | |
3995 | Thus, a masked watchpoint watches many addresses simultaneously---those | |
3996 | addresses whose unmasked bits are identical to the unmasked bits in the | |
3997 | watchpoint address. The @code{mask} argument implies @code{-location}. | |
3998 | Examples: | |
3999 | ||
4000 | @smallexample | |
4001 | (@value{GDBP}) watch foo mask 0xffff00ff | |
4002 | (@value{GDBP}) watch *0xdeadbeef mask 0xffffff00 | |
4003 | @end smallexample | |
4004 | ||
c906108c | 4005 | @kindex rwatch |
9c06b0b4 | 4006 | @item rwatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} @r{[}mask @var{maskvalue}@r{]} |
09d4efe1 EZ |
4007 | Set a watchpoint that will break when the value of @var{expr} is read |
4008 | by the program. | |
c906108c SS |
4009 | |
4010 | @kindex awatch | |
9c06b0b4 | 4011 | @item awatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} @r{[}mask @var{maskvalue}@r{]} |
09d4efe1 EZ |
4012 | Set a watchpoint that will break when @var{expr} is either read from |
4013 | or written into by the program. | |
c906108c | 4014 | |
e5a67952 MS |
4015 | @kindex info watchpoints @r{[}@var{n}@dots{}@r{]} |
4016 | @item info watchpoints @r{[}@var{n}@dots{}@r{]} | |
d77f58be SS |
4017 | This command prints a list of watchpoints, using the same format as |
4018 | @code{info break} (@pxref{Set Breaks}). | |
c906108c SS |
4019 | @end table |
4020 | ||
65d79d4b SDJ |
4021 | If you watch for a change in a numerically entered address you need to |
4022 | dereference it, as the address itself is just a constant number which will | |
4023 | never change. @value{GDBN} refuses to create a watchpoint that watches | |
4024 | a never-changing value: | |
4025 | ||
4026 | @smallexample | |
4027 | (@value{GDBP}) watch 0x600850 | |
4028 | Cannot watch constant value 0x600850. | |
4029 | (@value{GDBP}) watch *(int *) 0x600850 | |
4030 | Watchpoint 1: *(int *) 6293584 | |
4031 | @end smallexample | |
4032 | ||
c906108c SS |
4033 | @value{GDBN} sets a @dfn{hardware watchpoint} if possible. Hardware |
4034 | watchpoints execute very quickly, and the debugger reports a change in | |
4035 | value at the exact instruction where the change occurs. If @value{GDBN} | |
4036 | cannot set a hardware watchpoint, it sets a software watchpoint, which | |
4037 | executes more slowly and reports the change in value at the next | |
82f2d802 EZ |
4038 | @emph{statement}, not the instruction, after the change occurs. |
4039 | ||
82f2d802 EZ |
4040 | @cindex use only software watchpoints |
4041 | You can force @value{GDBN} to use only software watchpoints with the | |
4042 | @kbd{set can-use-hw-watchpoints 0} command. With this variable set to | |
4043 | zero, @value{GDBN} will never try to use hardware watchpoints, even if | |
4044 | the underlying system supports them. (Note that hardware-assisted | |
4045 | watchpoints that were set @emph{before} setting | |
4046 | @code{can-use-hw-watchpoints} to zero will still use the hardware | |
d3e8051b | 4047 | mechanism of watching expression values.) |
c906108c | 4048 | |
9c16f35a EZ |
4049 | @table @code |
4050 | @item set can-use-hw-watchpoints | |
4051 | @kindex set can-use-hw-watchpoints | |
4052 | Set whether or not to use hardware watchpoints. | |
4053 | ||
4054 | @item show can-use-hw-watchpoints | |
4055 | @kindex show can-use-hw-watchpoints | |
4056 | Show the current mode of using hardware watchpoints. | |
4057 | @end table | |
4058 | ||
4059 | For remote targets, you can restrict the number of hardware | |
4060 | watchpoints @value{GDBN} will use, see @ref{set remote | |
4061 | hardware-breakpoint-limit}. | |
4062 | ||
c906108c SS |
4063 | When you issue the @code{watch} command, @value{GDBN} reports |
4064 | ||
474c8240 | 4065 | @smallexample |
c906108c | 4066 | Hardware watchpoint @var{num}: @var{expr} |
474c8240 | 4067 | @end smallexample |
c906108c SS |
4068 | |
4069 | @noindent | |
4070 | if it was able to set a hardware watchpoint. | |
4071 | ||
7be570e7 JM |
4072 | Currently, the @code{awatch} and @code{rwatch} commands can only set |
4073 | hardware watchpoints, because accesses to data that don't change the | |
4074 | value of the watched expression cannot be detected without examining | |
4075 | every instruction as it is being executed, and @value{GDBN} does not do | |
4076 | that currently. If @value{GDBN} finds that it is unable to set a | |
4077 | hardware breakpoint with the @code{awatch} or @code{rwatch} command, it | |
4078 | will print a message like this: | |
4079 | ||
4080 | @smallexample | |
4081 | Expression cannot be implemented with read/access watchpoint. | |
4082 | @end smallexample | |
4083 | ||
4084 | Sometimes, @value{GDBN} cannot set a hardware watchpoint because the | |
4085 | data type of the watched expression is wider than what a hardware | |
4086 | watchpoint on the target machine can handle. For example, some systems | |
4087 | can only watch regions that are up to 4 bytes wide; on such systems you | |
4088 | cannot set hardware watchpoints for an expression that yields a | |
4089 | double-precision floating-point number (which is typically 8 bytes | |
4090 | wide). As a work-around, it might be possible to break the large region | |
4091 | into a series of smaller ones and watch them with separate watchpoints. | |
4092 | ||
4093 | If you set too many hardware watchpoints, @value{GDBN} might be unable | |
4094 | to insert all of them when you resume the execution of your program. | |
4095 | Since the precise number of active watchpoints is unknown until such | |
4096 | time as the program is about to be resumed, @value{GDBN} might not be | |
4097 | able to warn you about this when you set the watchpoints, and the | |
4098 | warning will be printed only when the program is resumed: | |
4099 | ||
4100 | @smallexample | |
4101 | Hardware watchpoint @var{num}: Could not insert watchpoint | |
4102 | @end smallexample | |
4103 | ||
4104 | @noindent | |
4105 | If this happens, delete or disable some of the watchpoints. | |
4106 | ||
fd60e0df EZ |
4107 | Watching complex expressions that reference many variables can also |
4108 | exhaust the resources available for hardware-assisted watchpoints. | |
4109 | That's because @value{GDBN} needs to watch every variable in the | |
4110 | expression with separately allocated resources. | |
4111 | ||
c906108c | 4112 | If you call a function interactively using @code{print} or @code{call}, |
2df3850c | 4113 | any watchpoints you have set will be inactive until @value{GDBN} reaches another |
c906108c SS |
4114 | kind of breakpoint or the call completes. |
4115 | ||
7be570e7 JM |
4116 | @value{GDBN} automatically deletes watchpoints that watch local |
4117 | (automatic) variables, or expressions that involve such variables, when | |
4118 | they go out of scope, that is, when the execution leaves the block in | |
4119 | which these variables were defined. In particular, when the program | |
4120 | being debugged terminates, @emph{all} local variables go out of scope, | |
4121 | and so only watchpoints that watch global variables remain set. If you | |
4122 | rerun the program, you will need to set all such watchpoints again. One | |
4123 | way of doing that would be to set a code breakpoint at the entry to the | |
4124 | @code{main} function and when it breaks, set all the watchpoints. | |
4125 | ||
c906108c SS |
4126 | @cindex watchpoints and threads |
4127 | @cindex threads and watchpoints | |
d983da9c DJ |
4128 | In multi-threaded programs, watchpoints will detect changes to the |
4129 | watched expression from every thread. | |
4130 | ||
4131 | @quotation | |
4132 | @emph{Warning:} In multi-threaded programs, software watchpoints | |
53a5351d JM |
4133 | have only limited usefulness. If @value{GDBN} creates a software |
4134 | watchpoint, it can only watch the value of an expression @emph{in a | |
4135 | single thread}. If you are confident that the expression can only | |
4136 | change due to the current thread's activity (and if you are also | |
4137 | confident that no other thread can become current), then you can use | |
4138 | software watchpoints as usual. However, @value{GDBN} may not notice | |
4139 | when a non-current thread's activity changes the expression. (Hardware | |
4140 | watchpoints, in contrast, watch an expression in all threads.) | |
c906108c | 4141 | @end quotation |
c906108c | 4142 | |
501eef12 AC |
4143 | @xref{set remote hardware-watchpoint-limit}. |
4144 | ||
6d2ebf8b | 4145 | @node Set Catchpoints |
79a6e687 | 4146 | @subsection Setting Catchpoints |
d4f3574e | 4147 | @cindex catchpoints, setting |
c906108c SS |
4148 | @cindex exception handlers |
4149 | @cindex event handling | |
4150 | ||
4151 | You can use @dfn{catchpoints} to cause the debugger to stop for certain | |
b37052ae | 4152 | kinds of program events, such as C@t{++} exceptions or the loading of a |
c906108c SS |
4153 | shared library. Use the @code{catch} command to set a catchpoint. |
4154 | ||
4155 | @table @code | |
4156 | @kindex catch | |
4157 | @item catch @var{event} | |
697aa1b7 | 4158 | Stop when @var{event} occurs. The @var{event} can be any of the following: |
591f19e8 | 4159 | |
c906108c | 4160 | @table @code |
cc16e6c9 TT |
4161 | @item throw @r{[}@var{regexp}@r{]} |
4162 | @itemx rethrow @r{[}@var{regexp}@r{]} | |
4163 | @itemx catch @r{[}@var{regexp}@r{]} | |
1a4f73eb TT |
4164 | @kindex catch throw |
4165 | @kindex catch rethrow | |
4166 | @kindex catch catch | |
4644b6e3 | 4167 | @cindex stop on C@t{++} exceptions |
591f19e8 TT |
4168 | The throwing, re-throwing, or catching of a C@t{++} exception. |
4169 | ||
cc16e6c9 TT |
4170 | If @var{regexp} is given, then only exceptions whose type matches the |
4171 | regular expression will be caught. | |
4172 | ||
72f1fe8a TT |
4173 | @vindex $_exception@r{, convenience variable} |
4174 | The convenience variable @code{$_exception} is available at an | |
4175 | exception-related catchpoint, on some systems. This holds the | |
4176 | exception being thrown. | |
4177 | ||
591f19e8 TT |
4178 | There are currently some limitations to C@t{++} exception handling in |
4179 | @value{GDBN}: | |
c906108c | 4180 | |
591f19e8 TT |
4181 | @itemize @bullet |
4182 | @item | |
4183 | The support for these commands is system-dependent. Currently, only | |
4184 | systems using the @samp{gnu-v3} C@t{++} ABI (@pxref{ABI}) are | |
4185 | supported. | |
4186 | ||
72f1fe8a | 4187 | @item |
cc16e6c9 TT |
4188 | The regular expression feature and the @code{$_exception} convenience |
4189 | variable rely on the presence of some SDT probes in @code{libstdc++}. | |
4190 | If these probes are not present, then these features cannot be used. | |
dee368d3 TT |
4191 | These probes were first available in the GCC 4.8 release, but whether |
4192 | or not they are available in your GCC also depends on how it was | |
4193 | built. | |
72f1fe8a TT |
4194 | |
4195 | @item | |
4196 | The @code{$_exception} convenience variable is only valid at the | |
4197 | instruction at which an exception-related catchpoint is set. | |
4198 | ||
591f19e8 TT |
4199 | @item |
4200 | When an exception-related catchpoint is hit, @value{GDBN} stops at a | |
4201 | location in the system library which implements runtime exception | |
4202 | support for C@t{++}, usually @code{libstdc++}. You can use @code{up} | |
4203 | (@pxref{Selection}) to get to your code. | |
4204 | ||
4205 | @item | |
4206 | If you call a function interactively, @value{GDBN} normally returns | |
4207 | control to you when the function has finished executing. If the call | |
4208 | raises an exception, however, the call may bypass the mechanism that | |
4209 | returns control to you and cause your program either to abort or to | |
4210 | simply continue running until it hits a breakpoint, catches a signal | |
4211 | that @value{GDBN} is listening for, or exits. This is the case even if | |
4212 | you set a catchpoint for the exception; catchpoints on exceptions are | |
4213 | disabled within interactive calls. @xref{Calling}, for information on | |
4214 | controlling this with @code{set unwind-on-terminating-exception}. | |
4215 | ||
4216 | @item | |
4217 | You cannot raise an exception interactively. | |
4218 | ||
4219 | @item | |
4220 | You cannot install an exception handler interactively. | |
4221 | @end itemize | |
c906108c | 4222 | |
8936fcda | 4223 | @item exception |
1a4f73eb | 4224 | @kindex catch exception |
8936fcda JB |
4225 | @cindex Ada exception catching |
4226 | @cindex catch Ada exceptions | |
4227 | An Ada exception being raised. If an exception name is specified | |
4228 | at the end of the command (eg @code{catch exception Program_Error}), | |
4229 | the debugger will stop only when this specific exception is raised. | |
4230 | Otherwise, the debugger stops execution when any Ada exception is raised. | |
4231 | ||
87f67dba JB |
4232 | When inserting an exception catchpoint on a user-defined exception whose |
4233 | name is identical to one of the exceptions defined by the language, the | |
4234 | fully qualified name must be used as the exception name. Otherwise, | |
4235 | @value{GDBN} will assume that it should stop on the pre-defined exception | |
4236 | rather than the user-defined one. For instance, assuming an exception | |
4237 | called @code{Constraint_Error} is defined in package @code{Pck}, then | |
4238 | the command to use to catch such exceptions is @kbd{catch exception | |
4239 | Pck.Constraint_Error}. | |
4240 | ||
8936fcda | 4241 | @item exception unhandled |
1a4f73eb | 4242 | @kindex catch exception unhandled |
8936fcda JB |
4243 | An exception that was raised but is not handled by the program. |
4244 | ||
4245 | @item assert | |
1a4f73eb | 4246 | @kindex catch assert |
8936fcda JB |
4247 | A failed Ada assertion. |
4248 | ||
c906108c | 4249 | @item exec |
1a4f73eb | 4250 | @kindex catch exec |
4644b6e3 | 4251 | @cindex break on fork/exec |
5ee187d7 DJ |
4252 | A call to @code{exec}. This is currently only available for HP-UX |
4253 | and @sc{gnu}/Linux. | |
c906108c | 4254 | |
a96d9b2e | 4255 | @item syscall |
ee8e71d4 | 4256 | @itemx syscall @r{[}@var{name} @r{|} @var{number}@r{]} @dots{} |
1a4f73eb | 4257 | @kindex catch syscall |
a96d9b2e SDJ |
4258 | @cindex break on a system call. |
4259 | A call to or return from a system call, a.k.a.@: @dfn{syscall}. A | |
4260 | syscall is a mechanism for application programs to request a service | |
4261 | from the operating system (OS) or one of the OS system services. | |
4262 | @value{GDBN} can catch some or all of the syscalls issued by the | |
4263 | debuggee, and show the related information for each syscall. If no | |
4264 | argument is specified, calls to and returns from all system calls | |
4265 | will be caught. | |
4266 | ||
4267 | @var{name} can be any system call name that is valid for the | |
4268 | underlying OS. Just what syscalls are valid depends on the OS. On | |
4269 | GNU and Unix systems, you can find the full list of valid syscall | |
4270 | names on @file{/usr/include/asm/unistd.h}. | |
4271 | ||
4272 | @c For MS-Windows, the syscall names and the corresponding numbers | |
4273 | @c can be found, e.g., on this URL: | |
4274 | @c http://www.metasploit.com/users/opcode/syscalls.html | |
4275 | @c but we don't support Windows syscalls yet. | |
4276 | ||
4277 | Normally, @value{GDBN} knows in advance which syscalls are valid for | |
4278 | each OS, so you can use the @value{GDBN} command-line completion | |
4279 | facilities (@pxref{Completion,, command completion}) to list the | |
4280 | available choices. | |
4281 | ||
4282 | You may also specify the system call numerically. A syscall's | |
4283 | number is the value passed to the OS's syscall dispatcher to | |
4284 | identify the requested service. When you specify the syscall by its | |
4285 | name, @value{GDBN} uses its database of syscalls to convert the name | |
4286 | into the corresponding numeric code, but using the number directly | |
4287 | may be useful if @value{GDBN}'s database does not have the complete | |
4288 | list of syscalls on your system (e.g., because @value{GDBN} lags | |
4289 | behind the OS upgrades). | |
4290 | ||
4291 | The example below illustrates how this command works if you don't provide | |
4292 | arguments to it: | |
4293 | ||
4294 | @smallexample | |
4295 | (@value{GDBP}) catch syscall | |
4296 | Catchpoint 1 (syscall) | |
4297 | (@value{GDBP}) r | |
4298 | Starting program: /tmp/catch-syscall | |
4299 | ||
4300 | Catchpoint 1 (call to syscall 'close'), \ | |
4301 | 0xffffe424 in __kernel_vsyscall () | |
4302 | (@value{GDBP}) c | |
4303 | Continuing. | |
4304 | ||
4305 | Catchpoint 1 (returned from syscall 'close'), \ | |
4306 | 0xffffe424 in __kernel_vsyscall () | |
4307 | (@value{GDBP}) | |
4308 | @end smallexample | |
4309 | ||
4310 | Here is an example of catching a system call by name: | |
4311 | ||
4312 | @smallexample | |
4313 | (@value{GDBP}) catch syscall chroot | |
4314 | Catchpoint 1 (syscall 'chroot' [61]) | |
4315 | (@value{GDBP}) r | |
4316 | Starting program: /tmp/catch-syscall | |
4317 | ||
4318 | Catchpoint 1 (call to syscall 'chroot'), \ | |
4319 | 0xffffe424 in __kernel_vsyscall () | |
4320 | (@value{GDBP}) c | |
4321 | Continuing. | |
4322 | ||
4323 | Catchpoint 1 (returned from syscall 'chroot'), \ | |
4324 | 0xffffe424 in __kernel_vsyscall () | |
4325 | (@value{GDBP}) | |
4326 | @end smallexample | |
4327 | ||
4328 | An example of specifying a system call numerically. In the case | |
4329 | below, the syscall number has a corresponding entry in the XML | |
4330 | file, so @value{GDBN} finds its name and prints it: | |
4331 | ||
4332 | @smallexample | |
4333 | (@value{GDBP}) catch syscall 252 | |
4334 | Catchpoint 1 (syscall(s) 'exit_group') | |
4335 | (@value{GDBP}) r | |
4336 | Starting program: /tmp/catch-syscall | |
4337 | ||
4338 | Catchpoint 1 (call to syscall 'exit_group'), \ | |
4339 | 0xffffe424 in __kernel_vsyscall () | |
4340 | (@value{GDBP}) c | |
4341 | Continuing. | |
4342 | ||
4343 | Program exited normally. | |
4344 | (@value{GDBP}) | |
4345 | @end smallexample | |
4346 | ||
4347 | However, there can be situations when there is no corresponding name | |
4348 | in XML file for that syscall number. In this case, @value{GDBN} prints | |
4349 | a warning message saying that it was not able to find the syscall name, | |
4350 | but the catchpoint will be set anyway. See the example below: | |
4351 | ||
4352 | @smallexample | |
4353 | (@value{GDBP}) catch syscall 764 | |
4354 | warning: The number '764' does not represent a known syscall. | |
4355 | Catchpoint 2 (syscall 764) | |
4356 | (@value{GDBP}) | |
4357 | @end smallexample | |
4358 | ||
4359 | If you configure @value{GDBN} using the @samp{--without-expat} option, | |
4360 | it will not be able to display syscall names. Also, if your | |
4361 | architecture does not have an XML file describing its system calls, | |
4362 | you will not be able to see the syscall names. It is important to | |
4363 | notice that these two features are used for accessing the syscall | |
4364 | name database. In either case, you will see a warning like this: | |
4365 | ||
4366 | @smallexample | |
4367 | (@value{GDBP}) catch syscall | |
4368 | warning: Could not open "syscalls/i386-linux.xml" | |
4369 | warning: Could not load the syscall XML file 'syscalls/i386-linux.xml'. | |
4370 | GDB will not be able to display syscall names. | |
4371 | Catchpoint 1 (syscall) | |
4372 | (@value{GDBP}) | |
4373 | @end smallexample | |
4374 | ||
4375 | Of course, the file name will change depending on your architecture and system. | |
4376 | ||
4377 | Still using the example above, you can also try to catch a syscall by its | |
4378 | number. In this case, you would see something like: | |
4379 | ||
4380 | @smallexample | |
4381 | (@value{GDBP}) catch syscall 252 | |
4382 | Catchpoint 1 (syscall(s) 252) | |
4383 | @end smallexample | |
4384 | ||
4385 | Again, in this case @value{GDBN} would not be able to display syscall's names. | |
4386 | ||
c906108c | 4387 | @item fork |
1a4f73eb | 4388 | @kindex catch fork |
5ee187d7 DJ |
4389 | A call to @code{fork}. This is currently only available for HP-UX |
4390 | and @sc{gnu}/Linux. | |
c906108c SS |
4391 | |
4392 | @item vfork | |
1a4f73eb | 4393 | @kindex catch vfork |
5ee187d7 DJ |
4394 | A call to @code{vfork}. This is currently only available for HP-UX |
4395 | and @sc{gnu}/Linux. | |
c906108c | 4396 | |
edcc5120 TT |
4397 | @item load @r{[}regexp@r{]} |
4398 | @itemx unload @r{[}regexp@r{]} | |
1a4f73eb TT |
4399 | @kindex catch load |
4400 | @kindex catch unload | |
edcc5120 TT |
4401 | The loading or unloading of a shared library. If @var{regexp} is |
4402 | given, then the catchpoint will stop only if the regular expression | |
4403 | matches one of the affected libraries. | |
4404 | ||
ab04a2af | 4405 | @item signal @r{[}@var{signal}@dots{} @r{|} @samp{all}@r{]} |
1a4f73eb | 4406 | @kindex catch signal |
ab04a2af TT |
4407 | The delivery of a signal. |
4408 | ||
4409 | With no arguments, this catchpoint will catch any signal that is not | |
4410 | used internally by @value{GDBN}, specifically, all signals except | |
4411 | @samp{SIGTRAP} and @samp{SIGINT}. | |
4412 | ||
4413 | With the argument @samp{all}, all signals, including those used by | |
4414 | @value{GDBN}, will be caught. This argument cannot be used with other | |
4415 | signal names. | |
4416 | ||
4417 | Otherwise, the arguments are a list of signal names as given to | |
4418 | @code{handle} (@pxref{Signals}). Only signals specified in this list | |
4419 | will be caught. | |
4420 | ||
4421 | One reason that @code{catch signal} can be more useful than | |
4422 | @code{handle} is that you can attach commands and conditions to the | |
4423 | catchpoint. | |
4424 | ||
4425 | When a signal is caught by a catchpoint, the signal's @code{stop} and | |
4426 | @code{print} settings, as specified by @code{handle}, are ignored. | |
4427 | However, whether the signal is still delivered to the inferior depends | |
4428 | on the @code{pass} setting; this can be changed in the catchpoint's | |
4429 | commands. | |
4430 | ||
c906108c SS |
4431 | @end table |
4432 | ||
4433 | @item tcatch @var{event} | |
1a4f73eb | 4434 | @kindex tcatch |
c906108c SS |
4435 | Set a catchpoint that is enabled only for one stop. The catchpoint is |
4436 | automatically deleted after the first time the event is caught. | |
4437 | ||
4438 | @end table | |
4439 | ||
4440 | Use the @code{info break} command to list the current catchpoints. | |
4441 | ||
c906108c | 4442 | |
6d2ebf8b | 4443 | @node Delete Breaks |
79a6e687 | 4444 | @subsection Deleting Breakpoints |
c906108c SS |
4445 | |
4446 | @cindex clearing breakpoints, watchpoints, catchpoints | |
4447 | @cindex deleting breakpoints, watchpoints, catchpoints | |
4448 | It is often necessary to eliminate a breakpoint, watchpoint, or | |
4449 | catchpoint once it has done its job and you no longer want your program | |
4450 | to stop there. This is called @dfn{deleting} the breakpoint. A | |
4451 | breakpoint that has been deleted no longer exists; it is forgotten. | |
4452 | ||
4453 | With the @code{clear} command you can delete breakpoints according to | |
4454 | where they are in your program. With the @code{delete} command you can | |
4455 | delete individual breakpoints, watchpoints, or catchpoints by specifying | |
4456 | their breakpoint numbers. | |
4457 | ||
4458 | It is not necessary to delete a breakpoint to proceed past it. @value{GDBN} | |
4459 | automatically ignores breakpoints on the first instruction to be executed | |
4460 | when you continue execution without changing the execution address. | |
4461 | ||
4462 | @table @code | |
4463 | @kindex clear | |
4464 | @item clear | |
4465 | Delete any breakpoints at the next instruction to be executed in the | |
79a6e687 | 4466 | selected stack frame (@pxref{Selection, ,Selecting a Frame}). When |
c906108c SS |
4467 | the innermost frame is selected, this is a good way to delete a |
4468 | breakpoint where your program just stopped. | |
4469 | ||
2a25a5ba EZ |
4470 | @item clear @var{location} |
4471 | Delete any breakpoints set at the specified @var{location}. | |
4472 | @xref{Specify Location}, for the various forms of @var{location}; the | |
4473 | most useful ones are listed below: | |
4474 | ||
4475 | @table @code | |
c906108c SS |
4476 | @item clear @var{function} |
4477 | @itemx clear @var{filename}:@var{function} | |
09d4efe1 | 4478 | Delete any breakpoints set at entry to the named @var{function}. |
c906108c SS |
4479 | |
4480 | @item clear @var{linenum} | |
4481 | @itemx clear @var{filename}:@var{linenum} | |
09d4efe1 EZ |
4482 | Delete any breakpoints set at or within the code of the specified |
4483 | @var{linenum} of the specified @var{filename}. | |
2a25a5ba | 4484 | @end table |
c906108c SS |
4485 | |
4486 | @cindex delete breakpoints | |
4487 | @kindex delete | |
41afff9a | 4488 | @kindex d @r{(@code{delete})} |
c5394b80 JM |
4489 | @item delete @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
4490 | Delete the breakpoints, watchpoints, or catchpoints of the breakpoint | |
4491 | ranges specified as arguments. If no argument is specified, delete all | |
c906108c SS |
4492 | breakpoints (@value{GDBN} asks confirmation, unless you have @code{set |
4493 | confirm off}). You can abbreviate this command as @code{d}. | |
4494 | @end table | |
4495 | ||
6d2ebf8b | 4496 | @node Disabling |
79a6e687 | 4497 | @subsection Disabling Breakpoints |
c906108c | 4498 | |
4644b6e3 | 4499 | @cindex enable/disable a breakpoint |
c906108c SS |
4500 | Rather than deleting a breakpoint, watchpoint, or catchpoint, you might |
4501 | prefer to @dfn{disable} it. This makes the breakpoint inoperative as if | |
4502 | it had been deleted, but remembers the information on the breakpoint so | |
4503 | that you can @dfn{enable} it again later. | |
4504 | ||
4505 | You disable and enable breakpoints, watchpoints, and catchpoints with | |
d77f58be SS |
4506 | the @code{enable} and @code{disable} commands, optionally specifying |
4507 | one or more breakpoint numbers as arguments. Use @code{info break} to | |
4508 | print a list of all breakpoints, watchpoints, and catchpoints if you | |
4509 | do not know which numbers to use. | |
c906108c | 4510 | |
3b784c4f EZ |
4511 | Disabling and enabling a breakpoint that has multiple locations |
4512 | affects all of its locations. | |
4513 | ||
816338b5 SS |
4514 | A breakpoint, watchpoint, or catchpoint can have any of several |
4515 | different states of enablement: | |
c906108c SS |
4516 | |
4517 | @itemize @bullet | |
4518 | @item | |
4519 | Enabled. The breakpoint stops your program. A breakpoint set | |
4520 | with the @code{break} command starts out in this state. | |
4521 | @item | |
4522 | Disabled. The breakpoint has no effect on your program. | |
4523 | @item | |
4524 | Enabled once. The breakpoint stops your program, but then becomes | |
d4f3574e | 4525 | disabled. |
c906108c | 4526 | @item |
816338b5 SS |
4527 | Enabled for a count. The breakpoint stops your program for the next |
4528 | N times, then becomes disabled. | |
4529 | @item | |
c906108c | 4530 | Enabled for deletion. The breakpoint stops your program, but |
d4f3574e SS |
4531 | immediately after it does so it is deleted permanently. A breakpoint |
4532 | set with the @code{tbreak} command starts out in this state. | |
c906108c SS |
4533 | @end itemize |
4534 | ||
4535 | You can use the following commands to enable or disable breakpoints, | |
4536 | watchpoints, and catchpoints: | |
4537 | ||
4538 | @table @code | |
c906108c | 4539 | @kindex disable |
41afff9a | 4540 | @kindex dis @r{(@code{disable})} |
c5394b80 | 4541 | @item disable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4542 | Disable the specified breakpoints---or all breakpoints, if none are |
4543 | listed. A disabled breakpoint has no effect but is not forgotten. All | |
4544 | options such as ignore-counts, conditions and commands are remembered in | |
4545 | case the breakpoint is enabled again later. You may abbreviate | |
4546 | @code{disable} as @code{dis}. | |
4547 | ||
c906108c | 4548 | @kindex enable |
c5394b80 | 4549 | @item enable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4550 | Enable the specified breakpoints (or all defined breakpoints). They |
4551 | become effective once again in stopping your program. | |
4552 | ||
c5394b80 | 4553 | @item enable @r{[}breakpoints@r{]} once @var{range}@dots{} |
c906108c SS |
4554 | Enable the specified breakpoints temporarily. @value{GDBN} disables any |
4555 | of these breakpoints immediately after stopping your program. | |
4556 | ||
816338b5 SS |
4557 | @item enable @r{[}breakpoints@r{]} count @var{count} @var{range}@dots{} |
4558 | Enable the specified breakpoints temporarily. @value{GDBN} records | |
4559 | @var{count} with each of the specified breakpoints, and decrements a | |
4560 | breakpoint's count when it is hit. When any count reaches 0, | |
4561 | @value{GDBN} disables that breakpoint. If a breakpoint has an ignore | |
4562 | count (@pxref{Conditions, ,Break Conditions}), that will be | |
4563 | decremented to 0 before @var{count} is affected. | |
4564 | ||
c5394b80 | 4565 | @item enable @r{[}breakpoints@r{]} delete @var{range}@dots{} |
c906108c SS |
4566 | Enable the specified breakpoints to work once, then die. @value{GDBN} |
4567 | deletes any of these breakpoints as soon as your program stops there. | |
09d4efe1 | 4568 | Breakpoints set by the @code{tbreak} command start out in this state. |
c906108c SS |
4569 | @end table |
4570 | ||
d4f3574e SS |
4571 | @c FIXME: I think the following ``Except for [...] @code{tbreak}'' is |
4572 | @c confusing: tbreak is also initially enabled. | |
c906108c | 4573 | Except for a breakpoint set with @code{tbreak} (@pxref{Set Breaks, |
79a6e687 | 4574 | ,Setting Breakpoints}), breakpoints that you set are initially enabled; |
c906108c SS |
4575 | subsequently, they become disabled or enabled only when you use one of |
4576 | the commands above. (The command @code{until} can set and delete a | |
4577 | breakpoint of its own, but it does not change the state of your other | |
4578 | breakpoints; see @ref{Continuing and Stepping, ,Continuing and | |
79a6e687 | 4579 | Stepping}.) |
c906108c | 4580 | |
6d2ebf8b | 4581 | @node Conditions |
79a6e687 | 4582 | @subsection Break Conditions |
c906108c SS |
4583 | @cindex conditional breakpoints |
4584 | @cindex breakpoint conditions | |
4585 | ||
4586 | @c FIXME what is scope of break condition expr? Context where wanted? | |
5d161b24 | 4587 | @c in particular for a watchpoint? |
c906108c SS |
4588 | The simplest sort of breakpoint breaks every time your program reaches a |
4589 | specified place. You can also specify a @dfn{condition} for a | |
4590 | breakpoint. A condition is just a Boolean expression in your | |
4591 | programming language (@pxref{Expressions, ,Expressions}). A breakpoint with | |
4592 | a condition evaluates the expression each time your program reaches it, | |
4593 | and your program stops only if the condition is @emph{true}. | |
4594 | ||
4595 | This is the converse of using assertions for program validation; in that | |
4596 | situation, you want to stop when the assertion is violated---that is, | |
4597 | when the condition is false. In C, if you want to test an assertion expressed | |
4598 | by the condition @var{assert}, you should set the condition | |
4599 | @samp{! @var{assert}} on the appropriate breakpoint. | |
4600 | ||
4601 | Conditions are also accepted for watchpoints; you may not need them, | |
4602 | since a watchpoint is inspecting the value of an expression anyhow---but | |
4603 | it might be simpler, say, to just set a watchpoint on a variable name, | |
4604 | and specify a condition that tests whether the new value is an interesting | |
4605 | one. | |
4606 | ||
4607 | Break conditions can have side effects, and may even call functions in | |
4608 | your program. This can be useful, for example, to activate functions | |
4609 | that log program progress, or to use your own print functions to | |
99e008fe | 4610 | format special data structures. The effects are completely predictable |
c906108c SS |
4611 | unless there is another enabled breakpoint at the same address. (In |
4612 | that case, @value{GDBN} might see the other breakpoint first and stop your | |
4613 | program without checking the condition of this one.) Note that | |
d4f3574e SS |
4614 | breakpoint commands are usually more convenient and flexible than break |
4615 | conditions for the | |
c906108c | 4616 | purpose of performing side effects when a breakpoint is reached |
79a6e687 | 4617 | (@pxref{Break Commands, ,Breakpoint Command Lists}). |
c906108c | 4618 | |
83364271 LM |
4619 | Breakpoint conditions can also be evaluated on the target's side if |
4620 | the target supports it. Instead of evaluating the conditions locally, | |
4621 | @value{GDBN} encodes the expression into an agent expression | |
4622 | (@pxref{Agent Expressions}) suitable for execution on the target, | |
4623 | independently of @value{GDBN}. Global variables become raw memory | |
4624 | locations, locals become stack accesses, and so forth. | |
4625 | ||
4626 | In this case, @value{GDBN} will only be notified of a breakpoint trigger | |
4627 | when its condition evaluates to true. This mechanism may provide faster | |
4628 | response times depending on the performance characteristics of the target | |
4629 | since it does not need to keep @value{GDBN} informed about | |
4630 | every breakpoint trigger, even those with false conditions. | |
4631 | ||
c906108c SS |
4632 | Break conditions can be specified when a breakpoint is set, by using |
4633 | @samp{if} in the arguments to the @code{break} command. @xref{Set | |
79a6e687 | 4634 | Breaks, ,Setting Breakpoints}. They can also be changed at any time |
c906108c | 4635 | with the @code{condition} command. |
53a5351d | 4636 | |
c906108c SS |
4637 | You can also use the @code{if} keyword with the @code{watch} command. |
4638 | The @code{catch} command does not recognize the @code{if} keyword; | |
4639 | @code{condition} is the only way to impose a further condition on a | |
4640 | catchpoint. | |
c906108c SS |
4641 | |
4642 | @table @code | |
4643 | @kindex condition | |
4644 | @item condition @var{bnum} @var{expression} | |
4645 | Specify @var{expression} as the break condition for breakpoint, | |
4646 | watchpoint, or catchpoint number @var{bnum}. After you set a condition, | |
4647 | breakpoint @var{bnum} stops your program only if the value of | |
4648 | @var{expression} is true (nonzero, in C). When you use | |
4649 | @code{condition}, @value{GDBN} checks @var{expression} immediately for | |
4650 | syntactic correctness, and to determine whether symbols in it have | |
d4f3574e SS |
4651 | referents in the context of your breakpoint. If @var{expression} uses |
4652 | symbols not referenced in the context of the breakpoint, @value{GDBN} | |
4653 | prints an error message: | |
4654 | ||
474c8240 | 4655 | @smallexample |
d4f3574e | 4656 | No symbol "foo" in current context. |
474c8240 | 4657 | @end smallexample |
d4f3574e SS |
4658 | |
4659 | @noindent | |
c906108c SS |
4660 | @value{GDBN} does |
4661 | not actually evaluate @var{expression} at the time the @code{condition} | |
d4f3574e SS |
4662 | command (or a command that sets a breakpoint with a condition, like |
4663 | @code{break if @dots{}}) is given, however. @xref{Expressions, ,Expressions}. | |
c906108c SS |
4664 | |
4665 | @item condition @var{bnum} | |
4666 | Remove the condition from breakpoint number @var{bnum}. It becomes | |
4667 | an ordinary unconditional breakpoint. | |
4668 | @end table | |
4669 | ||
4670 | @cindex ignore count (of breakpoint) | |
4671 | A special case of a breakpoint condition is to stop only when the | |
4672 | breakpoint has been reached a certain number of times. This is so | |
4673 | useful that there is a special way to do it, using the @dfn{ignore | |
4674 | count} of the breakpoint. Every breakpoint has an ignore count, which | |
4675 | is an integer. Most of the time, the ignore count is zero, and | |
4676 | therefore has no effect. But if your program reaches a breakpoint whose | |
4677 | ignore count is positive, then instead of stopping, it just decrements | |
4678 | the ignore count by one and continues. As a result, if the ignore count | |
4679 | value is @var{n}, the breakpoint does not stop the next @var{n} times | |
4680 | your program reaches it. | |
4681 | ||
4682 | @table @code | |
4683 | @kindex ignore | |
4684 | @item ignore @var{bnum} @var{count} | |
4685 | Set the ignore count of breakpoint number @var{bnum} to @var{count}. | |
4686 | The next @var{count} times the breakpoint is reached, your program's | |
4687 | execution does not stop; other than to decrement the ignore count, @value{GDBN} | |
4688 | takes no action. | |
4689 | ||
4690 | To make the breakpoint stop the next time it is reached, specify | |
4691 | a count of zero. | |
4692 | ||
4693 | When you use @code{continue} to resume execution of your program from a | |
4694 | breakpoint, you can specify an ignore count directly as an argument to | |
4695 | @code{continue}, rather than using @code{ignore}. @xref{Continuing and | |
79a6e687 | 4696 | Stepping,,Continuing and Stepping}. |
c906108c SS |
4697 | |
4698 | If a breakpoint has a positive ignore count and a condition, the | |
4699 | condition is not checked. Once the ignore count reaches zero, | |
4700 | @value{GDBN} resumes checking the condition. | |
4701 | ||
4702 | You could achieve the effect of the ignore count with a condition such | |
4703 | as @w{@samp{$foo-- <= 0}} using a debugger convenience variable that | |
4704 | is decremented each time. @xref{Convenience Vars, ,Convenience | |
79a6e687 | 4705 | Variables}. |
c906108c SS |
4706 | @end table |
4707 | ||
4708 | Ignore counts apply to breakpoints, watchpoints, and catchpoints. | |
4709 | ||
4710 | ||
6d2ebf8b | 4711 | @node Break Commands |
79a6e687 | 4712 | @subsection Breakpoint Command Lists |
c906108c SS |
4713 | |
4714 | @cindex breakpoint commands | |
4715 | You can give any breakpoint (or watchpoint or catchpoint) a series of | |
4716 | commands to execute when your program stops due to that breakpoint. For | |
4717 | example, you might want to print the values of certain expressions, or | |
4718 | enable other breakpoints. | |
4719 | ||
4720 | @table @code | |
4721 | @kindex commands | |
ca91424e | 4722 | @kindex end@r{ (breakpoint commands)} |
95a42b64 | 4723 | @item commands @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4724 | @itemx @dots{} @var{command-list} @dots{} |
4725 | @itemx end | |
95a42b64 | 4726 | Specify a list of commands for the given breakpoints. The commands |
c906108c SS |
4727 | themselves appear on the following lines. Type a line containing just |
4728 | @code{end} to terminate the commands. | |
4729 | ||
4730 | To remove all commands from a breakpoint, type @code{commands} and | |
4731 | follow it immediately with @code{end}; that is, give no commands. | |
4732 | ||
95a42b64 TT |
4733 | With no argument, @code{commands} refers to the last breakpoint, |
4734 | watchpoint, or catchpoint set (not to the breakpoint most recently | |
4735 | encountered). If the most recent breakpoints were set with a single | |
4736 | command, then the @code{commands} will apply to all the breakpoints | |
4737 | set by that command. This applies to breakpoints set by | |
86b17b60 PA |
4738 | @code{rbreak}, and also applies when a single @code{break} command |
4739 | creates multiple breakpoints (@pxref{Ambiguous Expressions,,Ambiguous | |
4740 | Expressions}). | |
c906108c SS |
4741 | @end table |
4742 | ||
4743 | Pressing @key{RET} as a means of repeating the last @value{GDBN} command is | |
4744 | disabled within a @var{command-list}. | |
4745 | ||
4746 | You can use breakpoint commands to start your program up again. Simply | |
4747 | use the @code{continue} command, or @code{step}, or any other command | |
4748 | that resumes execution. | |
4749 | ||
4750 | Any other commands in the command list, after a command that resumes | |
4751 | execution, are ignored. This is because any time you resume execution | |
4752 | (even with a simple @code{next} or @code{step}), you may encounter | |
4753 | another breakpoint---which could have its own command list, leading to | |
4754 | ambiguities about which list to execute. | |
4755 | ||
4756 | @kindex silent | |
4757 | If the first command you specify in a command list is @code{silent}, the | |
4758 | usual message about stopping at a breakpoint is not printed. This may | |
4759 | be desirable for breakpoints that are to print a specific message and | |
4760 | then continue. If none of the remaining commands print anything, you | |
4761 | see no sign that the breakpoint was reached. @code{silent} is | |
4762 | meaningful only at the beginning of a breakpoint command list. | |
4763 | ||
4764 | The commands @code{echo}, @code{output}, and @code{printf} allow you to | |
4765 | print precisely controlled output, and are often useful in silent | |
79a6e687 | 4766 | breakpoints. @xref{Output, ,Commands for Controlled Output}. |
c906108c SS |
4767 | |
4768 | For example, here is how you could use breakpoint commands to print the | |
4769 | value of @code{x} at entry to @code{foo} whenever @code{x} is positive. | |
4770 | ||
474c8240 | 4771 | @smallexample |
c906108c SS |
4772 | break foo if x>0 |
4773 | commands | |
4774 | silent | |
4775 | printf "x is %d\n",x | |
4776 | cont | |
4777 | end | |
474c8240 | 4778 | @end smallexample |
c906108c SS |
4779 | |
4780 | One application for breakpoint commands is to compensate for one bug so | |
4781 | you can test for another. Put a breakpoint just after the erroneous line | |
4782 | of code, give it a condition to detect the case in which something | |
4783 | erroneous has been done, and give it commands to assign correct values | |
4784 | to any variables that need them. End with the @code{continue} command | |
4785 | so that your program does not stop, and start with the @code{silent} | |
4786 | command so that no output is produced. Here is an example: | |
4787 | ||
474c8240 | 4788 | @smallexample |
c906108c SS |
4789 | break 403 |
4790 | commands | |
4791 | silent | |
4792 | set x = y + 4 | |
4793 | cont | |
4794 | end | |
474c8240 | 4795 | @end smallexample |
c906108c | 4796 | |
e7e0cddf SS |
4797 | @node Dynamic Printf |
4798 | @subsection Dynamic Printf | |
4799 | ||
4800 | @cindex dynamic printf | |
4801 | @cindex dprintf | |
4802 | The dynamic printf command @code{dprintf} combines a breakpoint with | |
4803 | formatted printing of your program's data to give you the effect of | |
4804 | inserting @code{printf} calls into your program on-the-fly, without | |
4805 | having to recompile it. | |
4806 | ||
4807 | In its most basic form, the output goes to the GDB console. However, | |
4808 | you can set the variable @code{dprintf-style} for alternate handling. | |
4809 | For instance, you can ask to format the output by calling your | |
4810 | program's @code{printf} function. This has the advantage that the | |
4811 | characters go to the program's output device, so they can recorded in | |
4812 | redirects to files and so forth. | |
4813 | ||
d3ce09f5 SS |
4814 | If you are doing remote debugging with a stub or agent, you can also |
4815 | ask to have the printf handled by the remote agent. In addition to | |
4816 | ensuring that the output goes to the remote program's device along | |
4817 | with any other output the program might produce, you can also ask that | |
4818 | the dprintf remain active even after disconnecting from the remote | |
4819 | target. Using the stub/agent is also more efficient, as it can do | |
4820 | everything without needing to communicate with @value{GDBN}. | |
4821 | ||
e7e0cddf SS |
4822 | @table @code |
4823 | @kindex dprintf | |
4824 | @item dprintf @var{location},@var{template},@var{expression}[,@var{expression}@dots{}] | |
4825 | Whenever execution reaches @var{location}, print the values of one or | |
4826 | more @var{expressions} under the control of the string @var{template}. | |
4827 | To print several values, separate them with commas. | |
4828 | ||
4829 | @item set dprintf-style @var{style} | |
4830 | Set the dprintf output to be handled in one of several different | |
4831 | styles enumerated below. A change of style affects all existing | |
4832 | dynamic printfs immediately. (If you need individual control over the | |
4833 | print commands, simply define normal breakpoints with | |
4834 | explicitly-supplied command lists.) | |
4835 | ||
4836 | @item gdb | |
4837 | @kindex dprintf-style gdb | |
4838 | Handle the output using the @value{GDBN} @code{printf} command. | |
4839 | ||
4840 | @item call | |
4841 | @kindex dprintf-style call | |
4842 | Handle the output by calling a function in your program (normally | |
4843 | @code{printf}). | |
4844 | ||
d3ce09f5 SS |
4845 | @item agent |
4846 | @kindex dprintf-style agent | |
4847 | Have the remote debugging agent (such as @code{gdbserver}) handle | |
4848 | the output itself. This style is only available for agents that | |
4849 | support running commands on the target. | |
4850 | ||
e7e0cddf SS |
4851 | @item set dprintf-function @var{function} |
4852 | Set the function to call if the dprintf style is @code{call}. By | |
4853 | default its value is @code{printf}. You may set it to any expression. | |
4854 | that @value{GDBN} can evaluate to a function, as per the @code{call} | |
4855 | command. | |
4856 | ||
4857 | @item set dprintf-channel @var{channel} | |
4858 | Set a ``channel'' for dprintf. If set to a non-empty value, | |
4859 | @value{GDBN} will evaluate it as an expression and pass the result as | |
4860 | a first argument to the @code{dprintf-function}, in the manner of | |
4861 | @code{fprintf} and similar functions. Otherwise, the dprintf format | |
4862 | string will be the first argument, in the manner of @code{printf}. | |
4863 | ||
4864 | As an example, if you wanted @code{dprintf} output to go to a logfile | |
4865 | that is a standard I/O stream assigned to the variable @code{mylog}, | |
4866 | you could do the following: | |
4867 | ||
4868 | @example | |
4869 | (gdb) set dprintf-style call | |
4870 | (gdb) set dprintf-function fprintf | |
4871 | (gdb) set dprintf-channel mylog | |
4872 | (gdb) dprintf 25,"at line 25, glob=%d\n",glob | |
4873 | Dprintf 1 at 0x123456: file main.c, line 25. | |
4874 | (gdb) info break | |
4875 | 1 dprintf keep y 0x00123456 in main at main.c:25 | |
4876 | call (void) fprintf (mylog,"at line 25, glob=%d\n",glob) | |
4877 | continue | |
4878 | (gdb) | |
4879 | @end example | |
4880 | ||
4881 | Note that the @code{info break} displays the dynamic printf commands | |
4882 | as normal breakpoint commands; you can thus easily see the effect of | |
4883 | the variable settings. | |
4884 | ||
d3ce09f5 SS |
4885 | @item set disconnected-dprintf on |
4886 | @itemx set disconnected-dprintf off | |
4887 | @kindex set disconnected-dprintf | |
4888 | Choose whether @code{dprintf} commands should continue to run if | |
4889 | @value{GDBN} has disconnected from the target. This only applies | |
4890 | if the @code{dprintf-style} is @code{agent}. | |
4891 | ||
4892 | @item show disconnected-dprintf off | |
4893 | @kindex show disconnected-dprintf | |
4894 | Show the current choice for disconnected @code{dprintf}. | |
4895 | ||
e7e0cddf SS |
4896 | @end table |
4897 | ||
4898 | @value{GDBN} does not check the validity of function and channel, | |
4899 | relying on you to supply values that are meaningful for the contexts | |
4900 | in which they are being used. For instance, the function and channel | |
4901 | may be the values of local variables, but if that is the case, then | |
4902 | all enabled dynamic prints must be at locations within the scope of | |
4903 | those locals. If evaluation fails, @value{GDBN} will report an error. | |
4904 | ||
6149aea9 PA |
4905 | @node Save Breakpoints |
4906 | @subsection How to save breakpoints to a file | |
4907 | ||
4908 | To save breakpoint definitions to a file use the @w{@code{save | |
4909 | breakpoints}} command. | |
4910 | ||
4911 | @table @code | |
4912 | @kindex save breakpoints | |
4913 | @cindex save breakpoints to a file for future sessions | |
4914 | @item save breakpoints [@var{filename}] | |
4915 | This command saves all current breakpoint definitions together with | |
4916 | their commands and ignore counts, into a file @file{@var{filename}} | |
4917 | suitable for use in a later debugging session. This includes all | |
4918 | types of breakpoints (breakpoints, watchpoints, catchpoints, | |
4919 | tracepoints). To read the saved breakpoint definitions, use the | |
4920 | @code{source} command (@pxref{Command Files}). Note that watchpoints | |
4921 | with expressions involving local variables may fail to be recreated | |
4922 | because it may not be possible to access the context where the | |
4923 | watchpoint is valid anymore. Because the saved breakpoint definitions | |
4924 | are simply a sequence of @value{GDBN} commands that recreate the | |
4925 | breakpoints, you can edit the file in your favorite editing program, | |
4926 | and remove the breakpoint definitions you're not interested in, or | |
4927 | that can no longer be recreated. | |
4928 | @end table | |
4929 | ||
62e5f89c SDJ |
4930 | @node Static Probe Points |
4931 | @subsection Static Probe Points | |
4932 | ||
4933 | @cindex static probe point, SystemTap | |
4934 | @value{GDBN} supports @dfn{SDT} probes in the code. @acronym{SDT} stands | |
4935 | for Statically Defined Tracing, and the probes are designed to have a tiny | |
4936 | runtime code and data footprint, and no dynamic relocations. They are | |
4937 | usable from assembly, C and C@t{++} languages. See | |
4938 | @uref{http://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation} | |
4939 | for a good reference on how the @acronym{SDT} probes are implemented. | |
4940 | ||
4941 | Currently, @code{SystemTap} (@uref{http://sourceware.org/systemtap/}) | |
4942 | @acronym{SDT} probes are supported on ELF-compatible systems. See | |
4943 | @uref{http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps} | |
4944 | for more information on how to add @code{SystemTap} @acronym{SDT} probes | |
4945 | in your applications. | |
4946 | ||
4947 | @cindex semaphores on static probe points | |
4948 | Some probes have an associated semaphore variable; for instance, this | |
4949 | happens automatically if you defined your probe using a DTrace-style | |
4950 | @file{.d} file. If your probe has a semaphore, @value{GDBN} will | |
4951 | automatically enable it when you specify a breakpoint using the | |
4952 | @samp{-probe-stap} notation. But, if you put a breakpoint at a probe's | |
4953 | location by some other method (e.g., @code{break file:line}), then | |
4954 | @value{GDBN} will not automatically set the semaphore. | |
4955 | ||
4956 | You can examine the available static static probes using @code{info | |
4957 | probes}, with optional arguments: | |
4958 | ||
4959 | @table @code | |
4960 | @kindex info probes | |
4961 | @item info probes stap @r{[}@var{provider} @r{[}@var{name} @r{[}@var{objfile}@r{]}@r{]}@r{]} | |
4962 | If given, @var{provider} is a regular expression used to match against provider | |
4963 | names when selecting which probes to list. If omitted, probes by all | |
4964 | probes from all providers are listed. | |
4965 | ||
4966 | If given, @var{name} is a regular expression to match against probe names | |
4967 | when selecting which probes to list. If omitted, probe names are not | |
4968 | considered when deciding whether to display them. | |
4969 | ||
4970 | If given, @var{objfile} is a regular expression used to select which | |
4971 | object files (executable or shared libraries) to examine. If not | |
4972 | given, all object files are considered. | |
4973 | ||
4974 | @item info probes all | |
4975 | List the available static probes, from all types. | |
4976 | @end table | |
4977 | ||
4978 | @vindex $_probe_arg@r{, convenience variable} | |
4979 | A probe may specify up to twelve arguments. These are available at the | |
4980 | point at which the probe is defined---that is, when the current PC is | |
4981 | at the probe's location. The arguments are available using the | |
4982 | convenience variables (@pxref{Convenience Vars}) | |
4983 | @code{$_probe_arg0}@dots{}@code{$_probe_arg11}. Each probe argument is | |
4984 | an integer of the appropriate size; types are not preserved. The | |
4985 | convenience variable @code{$_probe_argc} holds the number of arguments | |
4986 | at the current probe point. | |
4987 | ||
4988 | These variables are always available, but attempts to access them at | |
4989 | any location other than a probe point will cause @value{GDBN} to give | |
4990 | an error message. | |
4991 | ||
4992 | ||
c906108c | 4993 | @c @ifclear BARETARGET |
6d2ebf8b | 4994 | @node Error in Breakpoints |
d4f3574e | 4995 | @subsection ``Cannot insert breakpoints'' |
c906108c | 4996 | |
fa3a767f PA |
4997 | If you request too many active hardware-assisted breakpoints and |
4998 | watchpoints, you will see this error message: | |
d4f3574e SS |
4999 | |
5000 | @c FIXME: the precise wording of this message may change; the relevant | |
5001 | @c source change is not committed yet (Sep 3, 1999). | |
5002 | @smallexample | |
5003 | Stopped; cannot insert breakpoints. | |
5004 | You may have requested too many hardware breakpoints and watchpoints. | |
5005 | @end smallexample | |
5006 | ||
5007 | @noindent | |
5008 | This message is printed when you attempt to resume the program, since | |
5009 | only then @value{GDBN} knows exactly how many hardware breakpoints and | |
5010 | watchpoints it needs to insert. | |
5011 | ||
5012 | When this message is printed, you need to disable or remove some of the | |
5013 | hardware-assisted breakpoints and watchpoints, and then continue. | |
5014 | ||
79a6e687 | 5015 | @node Breakpoint-related Warnings |
1485d690 KB |
5016 | @subsection ``Breakpoint address adjusted...'' |
5017 | @cindex breakpoint address adjusted | |
5018 | ||
5019 | Some processor architectures place constraints on the addresses at | |
5020 | which breakpoints may be placed. For architectures thus constrained, | |
5021 | @value{GDBN} will attempt to adjust the breakpoint's address to comply | |
5022 | with the constraints dictated by the architecture. | |
5023 | ||
5024 | One example of such an architecture is the Fujitsu FR-V. The FR-V is | |
5025 | a VLIW architecture in which a number of RISC-like instructions may be | |
5026 | bundled together for parallel execution. The FR-V architecture | |
5027 | constrains the location of a breakpoint instruction within such a | |
5028 | bundle to the instruction with the lowest address. @value{GDBN} | |
5029 | honors this constraint by adjusting a breakpoint's address to the | |
5030 | first in the bundle. | |
5031 | ||
5032 | It is not uncommon for optimized code to have bundles which contain | |
5033 | instructions from different source statements, thus it may happen that | |
5034 | a breakpoint's address will be adjusted from one source statement to | |
5035 | another. Since this adjustment may significantly alter @value{GDBN}'s | |
5036 | breakpoint related behavior from what the user expects, a warning is | |
5037 | printed when the breakpoint is first set and also when the breakpoint | |
5038 | is hit. | |
5039 | ||
5040 | A warning like the one below is printed when setting a breakpoint | |
5041 | that's been subject to address adjustment: | |
5042 | ||
5043 | @smallexample | |
5044 | warning: Breakpoint address adjusted from 0x00010414 to 0x00010410. | |
5045 | @end smallexample | |
5046 | ||
5047 | Such warnings are printed both for user settable and @value{GDBN}'s | |
5048 | internal breakpoints. If you see one of these warnings, you should | |
5049 | verify that a breakpoint set at the adjusted address will have the | |
5050 | desired affect. If not, the breakpoint in question may be removed and | |
b383017d | 5051 | other breakpoints may be set which will have the desired behavior. |
1485d690 KB |
5052 | E.g., it may be sufficient to place the breakpoint at a later |
5053 | instruction. A conditional breakpoint may also be useful in some | |
5054 | cases to prevent the breakpoint from triggering too often. | |
5055 | ||
5056 | @value{GDBN} will also issue a warning when stopping at one of these | |
5057 | adjusted breakpoints: | |
5058 | ||
5059 | @smallexample | |
5060 | warning: Breakpoint 1 address previously adjusted from 0x00010414 | |
5061 | to 0x00010410. | |
5062 | @end smallexample | |
5063 | ||
5064 | When this warning is encountered, it may be too late to take remedial | |
5065 | action except in cases where the breakpoint is hit earlier or more | |
5066 | frequently than expected. | |
d4f3574e | 5067 | |
6d2ebf8b | 5068 | @node Continuing and Stepping |
79a6e687 | 5069 | @section Continuing and Stepping |
c906108c SS |
5070 | |
5071 | @cindex stepping | |
5072 | @cindex continuing | |
5073 | @cindex resuming execution | |
5074 | @dfn{Continuing} means resuming program execution until your program | |
5075 | completes normally. In contrast, @dfn{stepping} means executing just | |
5076 | one more ``step'' of your program, where ``step'' may mean either one | |
5077 | line of source code, or one machine instruction (depending on what | |
7a292a7a SS |
5078 | particular command you use). Either when continuing or when stepping, |
5079 | your program may stop even sooner, due to a breakpoint or a signal. (If | |
d4f3574e SS |
5080 | it stops due to a signal, you may want to use @code{handle}, or use |
5081 | @samp{signal 0} to resume execution. @xref{Signals, ,Signals}.) | |
c906108c SS |
5082 | |
5083 | @table @code | |
5084 | @kindex continue | |
41afff9a EZ |
5085 | @kindex c @r{(@code{continue})} |
5086 | @kindex fg @r{(resume foreground execution)} | |
c906108c SS |
5087 | @item continue @r{[}@var{ignore-count}@r{]} |
5088 | @itemx c @r{[}@var{ignore-count}@r{]} | |
5089 | @itemx fg @r{[}@var{ignore-count}@r{]} | |
5090 | Resume program execution, at the address where your program last stopped; | |
5091 | any breakpoints set at that address are bypassed. The optional argument | |
5092 | @var{ignore-count} allows you to specify a further number of times to | |
5093 | ignore a breakpoint at this location; its effect is like that of | |
79a6e687 | 5094 | @code{ignore} (@pxref{Conditions, ,Break Conditions}). |
c906108c SS |
5095 | |
5096 | The argument @var{ignore-count} is meaningful only when your program | |
5097 | stopped due to a breakpoint. At other times, the argument to | |
5098 | @code{continue} is ignored. | |
5099 | ||
d4f3574e SS |
5100 | The synonyms @code{c} and @code{fg} (for @dfn{foreground}, as the |
5101 | debugged program is deemed to be the foreground program) are provided | |
5102 | purely for convenience, and have exactly the same behavior as | |
5103 | @code{continue}. | |
c906108c SS |
5104 | @end table |
5105 | ||
5106 | To resume execution at a different place, you can use @code{return} | |
79a6e687 | 5107 | (@pxref{Returning, ,Returning from a Function}) to go back to the |
c906108c | 5108 | calling function; or @code{jump} (@pxref{Jumping, ,Continuing at a |
79a6e687 | 5109 | Different Address}) to go to an arbitrary location in your program. |
c906108c SS |
5110 | |
5111 | A typical technique for using stepping is to set a breakpoint | |
79a6e687 | 5112 | (@pxref{Breakpoints, ,Breakpoints; Watchpoints; and Catchpoints}) at the |
c906108c SS |
5113 | beginning of the function or the section of your program where a problem |
5114 | is believed to lie, run your program until it stops at that breakpoint, | |
5115 | and then step through the suspect area, examining the variables that are | |
5116 | interesting, until you see the problem happen. | |
5117 | ||
5118 | @table @code | |
5119 | @kindex step | |
41afff9a | 5120 | @kindex s @r{(@code{step})} |
c906108c SS |
5121 | @item step |
5122 | Continue running your program until control reaches a different source | |
5123 | line, then stop it and return control to @value{GDBN}. This command is | |
5124 | abbreviated @code{s}. | |
5125 | ||
5126 | @quotation | |
5127 | @c "without debugging information" is imprecise; actually "without line | |
5128 | @c numbers in the debugging information". (gcc -g1 has debugging info but | |
5129 | @c not line numbers). But it seems complex to try to make that | |
5130 | @c distinction here. | |
5131 | @emph{Warning:} If you use the @code{step} command while control is | |
5132 | within a function that was compiled without debugging information, | |
5133 | execution proceeds until control reaches a function that does have | |
5134 | debugging information. Likewise, it will not step into a function which | |
5135 | is compiled without debugging information. To step through functions | |
5136 | without debugging information, use the @code{stepi} command, described | |
5137 | below. | |
5138 | @end quotation | |
5139 | ||
4a92d011 EZ |
5140 | The @code{step} command only stops at the first instruction of a source |
5141 | line. This prevents the multiple stops that could otherwise occur in | |
5142 | @code{switch} statements, @code{for} loops, etc. @code{step} continues | |
5143 | to stop if a function that has debugging information is called within | |
5144 | the line. In other words, @code{step} @emph{steps inside} any functions | |
5145 | called within the line. | |
c906108c | 5146 | |
d4f3574e SS |
5147 | Also, the @code{step} command only enters a function if there is line |
5148 | number information for the function. Otherwise it acts like the | |
5d161b24 | 5149 | @code{next} command. This avoids problems when using @code{cc -gl} |
eb17f351 | 5150 | on @acronym{MIPS} machines. Previously, @code{step} entered subroutines if there |
5d161b24 | 5151 | was any debugging information about the routine. |
c906108c SS |
5152 | |
5153 | @item step @var{count} | |
5154 | Continue running as in @code{step}, but do so @var{count} times. If a | |
7a292a7a SS |
5155 | breakpoint is reached, or a signal not related to stepping occurs before |
5156 | @var{count} steps, stepping stops right away. | |
c906108c SS |
5157 | |
5158 | @kindex next | |
41afff9a | 5159 | @kindex n @r{(@code{next})} |
c906108c SS |
5160 | @item next @r{[}@var{count}@r{]} |
5161 | Continue to the next source line in the current (innermost) stack frame. | |
7a292a7a SS |
5162 | This is similar to @code{step}, but function calls that appear within |
5163 | the line of code are executed without stopping. Execution stops when | |
5164 | control reaches a different line of code at the original stack level | |
5165 | that was executing when you gave the @code{next} command. This command | |
5166 | is abbreviated @code{n}. | |
c906108c SS |
5167 | |
5168 | An argument @var{count} is a repeat count, as for @code{step}. | |
5169 | ||
5170 | ||
5171 | @c FIX ME!! Do we delete this, or is there a way it fits in with | |
5172 | @c the following paragraph? --- Vctoria | |
5173 | @c | |
5174 | @c @code{next} within a function that lacks debugging information acts like | |
5175 | @c @code{step}, but any function calls appearing within the code of the | |
5176 | @c function are executed without stopping. | |
5177 | ||
d4f3574e SS |
5178 | The @code{next} command only stops at the first instruction of a |
5179 | source line. This prevents multiple stops that could otherwise occur in | |
4a92d011 | 5180 | @code{switch} statements, @code{for} loops, etc. |
c906108c | 5181 | |
b90a5f51 CF |
5182 | @kindex set step-mode |
5183 | @item set step-mode | |
5184 | @cindex functions without line info, and stepping | |
5185 | @cindex stepping into functions with no line info | |
5186 | @itemx set step-mode on | |
4a92d011 | 5187 | The @code{set step-mode on} command causes the @code{step} command to |
b90a5f51 CF |
5188 | stop at the first instruction of a function which contains no debug line |
5189 | information rather than stepping over it. | |
5190 | ||
4a92d011 EZ |
5191 | This is useful in cases where you may be interested in inspecting the |
5192 | machine instructions of a function which has no symbolic info and do not | |
5193 | want @value{GDBN} to automatically skip over this function. | |
b90a5f51 CF |
5194 | |
5195 | @item set step-mode off | |
4a92d011 | 5196 | Causes the @code{step} command to step over any functions which contains no |
b90a5f51 CF |
5197 | debug information. This is the default. |
5198 | ||
9c16f35a EZ |
5199 | @item show step-mode |
5200 | Show whether @value{GDBN} will stop in or step over functions without | |
5201 | source line debug information. | |
5202 | ||
c906108c | 5203 | @kindex finish |
8dfa32fc | 5204 | @kindex fin @r{(@code{finish})} |
c906108c SS |
5205 | @item finish |
5206 | Continue running until just after function in the selected stack frame | |
8dfa32fc JB |
5207 | returns. Print the returned value (if any). This command can be |
5208 | abbreviated as @code{fin}. | |
c906108c SS |
5209 | |
5210 | Contrast this with the @code{return} command (@pxref{Returning, | |
79a6e687 | 5211 | ,Returning from a Function}). |
c906108c SS |
5212 | |
5213 | @kindex until | |
41afff9a | 5214 | @kindex u @r{(@code{until})} |
09d4efe1 | 5215 | @cindex run until specified location |
c906108c SS |
5216 | @item until |
5217 | @itemx u | |
5218 | Continue running until a source line past the current line, in the | |
5219 | current stack frame, is reached. This command is used to avoid single | |
5220 | stepping through a loop more than once. It is like the @code{next} | |
5221 | command, except that when @code{until} encounters a jump, it | |
5222 | automatically continues execution until the program counter is greater | |
5223 | than the address of the jump. | |
5224 | ||
5225 | This means that when you reach the end of a loop after single stepping | |
5226 | though it, @code{until} makes your program continue execution until it | |
5227 | exits the loop. In contrast, a @code{next} command at the end of a loop | |
5228 | simply steps back to the beginning of the loop, which forces you to step | |
5229 | through the next iteration. | |
5230 | ||
5231 | @code{until} always stops your program if it attempts to exit the current | |
5232 | stack frame. | |
5233 | ||
5234 | @code{until} may produce somewhat counterintuitive results if the order | |
5235 | of machine code does not match the order of the source lines. For | |
5236 | example, in the following excerpt from a debugging session, the @code{f} | |
5237 | (@code{frame}) command shows that execution is stopped at line | |
5238 | @code{206}; yet when we use @code{until}, we get to line @code{195}: | |
5239 | ||
474c8240 | 5240 | @smallexample |
c906108c SS |
5241 | (@value{GDBP}) f |
5242 | #0 main (argc=4, argv=0xf7fffae8) at m4.c:206 | |
5243 | 206 expand_input(); | |
5244 | (@value{GDBP}) until | |
5245 | 195 for ( ; argc > 0; NEXTARG) @{ | |
474c8240 | 5246 | @end smallexample |
c906108c SS |
5247 | |
5248 | This happened because, for execution efficiency, the compiler had | |
5249 | generated code for the loop closure test at the end, rather than the | |
5250 | start, of the loop---even though the test in a C @code{for}-loop is | |
5251 | written before the body of the loop. The @code{until} command appeared | |
5252 | to step back to the beginning of the loop when it advanced to this | |
5253 | expression; however, it has not really gone to an earlier | |
5254 | statement---not in terms of the actual machine code. | |
5255 | ||
5256 | @code{until} with no argument works by means of single | |
5257 | instruction stepping, and hence is slower than @code{until} with an | |
5258 | argument. | |
5259 | ||
5260 | @item until @var{location} | |
5261 | @itemx u @var{location} | |
697aa1b7 EZ |
5262 | Continue running your program until either the specified @var{location} is |
5263 | reached, or the current stack frame returns. The location is any of | |
2a25a5ba EZ |
5264 | the forms described in @ref{Specify Location}. |
5265 | This form of the command uses temporary breakpoints, and | |
c60eb6f1 EZ |
5266 | hence is quicker than @code{until} without an argument. The specified |
5267 | location is actually reached only if it is in the current frame. This | |
5268 | implies that @code{until} can be used to skip over recursive function | |
5269 | invocations. For instance in the code below, if the current location is | |
5270 | line @code{96}, issuing @code{until 99} will execute the program up to | |
db2e3e2e | 5271 | line @code{99} in the same invocation of factorial, i.e., after the inner |
c60eb6f1 EZ |
5272 | invocations have returned. |
5273 | ||
5274 | @smallexample | |
5275 | 94 int factorial (int value) | |
5276 | 95 @{ | |
5277 | 96 if (value > 1) @{ | |
5278 | 97 value *= factorial (value - 1); | |
5279 | 98 @} | |
5280 | 99 return (value); | |
5281 | 100 @} | |
5282 | @end smallexample | |
5283 | ||
5284 | ||
5285 | @kindex advance @var{location} | |
984359d2 | 5286 | @item advance @var{location} |
09d4efe1 | 5287 | Continue running the program up to the given @var{location}. An argument is |
2a25a5ba EZ |
5288 | required, which should be of one of the forms described in |
5289 | @ref{Specify Location}. | |
5290 | Execution will also stop upon exit from the current stack | |
c60eb6f1 EZ |
5291 | frame. This command is similar to @code{until}, but @code{advance} will |
5292 | not skip over recursive function calls, and the target location doesn't | |
5293 | have to be in the same frame as the current one. | |
5294 | ||
c906108c SS |
5295 | |
5296 | @kindex stepi | |
41afff9a | 5297 | @kindex si @r{(@code{stepi})} |
c906108c | 5298 | @item stepi |
96a2c332 | 5299 | @itemx stepi @var{arg} |
c906108c SS |
5300 | @itemx si |
5301 | Execute one machine instruction, then stop and return to the debugger. | |
5302 | ||
5303 | It is often useful to do @samp{display/i $pc} when stepping by machine | |
5304 | instructions. This makes @value{GDBN} automatically display the next | |
5305 | instruction to be executed, each time your program stops. @xref{Auto | |
79a6e687 | 5306 | Display,, Automatic Display}. |
c906108c SS |
5307 | |
5308 | An argument is a repeat count, as in @code{step}. | |
5309 | ||
5310 | @need 750 | |
5311 | @kindex nexti | |
41afff9a | 5312 | @kindex ni @r{(@code{nexti})} |
c906108c | 5313 | @item nexti |
96a2c332 | 5314 | @itemx nexti @var{arg} |
c906108c SS |
5315 | @itemx ni |
5316 | Execute one machine instruction, but if it is a function call, | |
5317 | proceed until the function returns. | |
5318 | ||
5319 | An argument is a repeat count, as in @code{next}. | |
c1e36e3e PA |
5320 | |
5321 | @end table | |
5322 | ||
5323 | @anchor{range stepping} | |
5324 | @cindex range stepping | |
5325 | @cindex target-assisted range stepping | |
5326 | By default, and if available, @value{GDBN} makes use of | |
5327 | target-assisted @dfn{range stepping}. In other words, whenever you | |
5328 | use a stepping command (e.g., @code{step}, @code{next}), @value{GDBN} | |
5329 | tells the target to step the corresponding range of instruction | |
5330 | addresses instead of issuing multiple single-steps. This speeds up | |
5331 | line stepping, particularly for remote targets. Ideally, there should | |
5332 | be no reason you would want to turn range stepping off. However, it's | |
5333 | possible that a bug in the debug info, a bug in the remote stub (for | |
5334 | remote targets), or even a bug in @value{GDBN} could make line | |
5335 | stepping behave incorrectly when target-assisted range stepping is | |
5336 | enabled. You can use the following command to turn off range stepping | |
5337 | if necessary: | |
5338 | ||
5339 | @table @code | |
5340 | @kindex set range-stepping | |
5341 | @kindex show range-stepping | |
5342 | @item set range-stepping | |
5343 | @itemx show range-stepping | |
5344 | Control whether range stepping is enabled. | |
5345 | ||
5346 | If @code{on}, and the target supports it, @value{GDBN} tells the | |
5347 | target to step a range of addresses itself, instead of issuing | |
5348 | multiple single-steps. If @code{off}, @value{GDBN} always issues | |
5349 | single-steps, even if range stepping is supported by the target. The | |
5350 | default is @code{on}. | |
5351 | ||
c906108c SS |
5352 | @end table |
5353 | ||
aad1c02c TT |
5354 | @node Skipping Over Functions and Files |
5355 | @section Skipping Over Functions and Files | |
1bfeeb0f JL |
5356 | @cindex skipping over functions and files |
5357 | ||
5358 | The program you are debugging may contain some functions which are | |
5359 | uninteresting to debug. The @code{skip} comand lets you tell @value{GDBN} to | |
5360 | skip a function or all functions in a file when stepping. | |
5361 | ||
5362 | For example, consider the following C function: | |
5363 | ||
5364 | @smallexample | |
5365 | 101 int func() | |
5366 | 102 @{ | |
5367 | 103 foo(boring()); | |
5368 | 104 bar(boring()); | |
5369 | 105 @} | |
5370 | @end smallexample | |
5371 | ||
5372 | @noindent | |
5373 | Suppose you wish to step into the functions @code{foo} and @code{bar}, but you | |
5374 | are not interested in stepping through @code{boring}. If you run @code{step} | |
5375 | at line 103, you'll enter @code{boring()}, but if you run @code{next}, you'll | |
5376 | step over both @code{foo} and @code{boring}! | |
5377 | ||
5378 | One solution is to @code{step} into @code{boring} and use the @code{finish} | |
5379 | command to immediately exit it. But this can become tedious if @code{boring} | |
5380 | is called from many places. | |
5381 | ||
5382 | A more flexible solution is to execute @kbd{skip boring}. This instructs | |
5383 | @value{GDBN} never to step into @code{boring}. Now when you execute | |
5384 | @code{step} at line 103, you'll step over @code{boring} and directly into | |
5385 | @code{foo}. | |
5386 | ||
5387 | You can also instruct @value{GDBN} to skip all functions in a file, with, for | |
5388 | example, @code{skip file boring.c}. | |
5389 | ||
5390 | @table @code | |
5391 | @kindex skip function | |
5392 | @item skip @r{[}@var{linespec}@r{]} | |
5393 | @itemx skip function @r{[}@var{linespec}@r{]} | |
5394 | After running this command, the function named by @var{linespec} or the | |
5395 | function containing the line named by @var{linespec} will be skipped over when | |
983fb131 | 5396 | stepping. @xref{Specify Location}. |
1bfeeb0f JL |
5397 | |
5398 | If you do not specify @var{linespec}, the function you're currently debugging | |
5399 | will be skipped. | |
5400 | ||
5401 | (If you have a function called @code{file} that you want to skip, use | |
5402 | @kbd{skip function file}.) | |
5403 | ||
5404 | @kindex skip file | |
5405 | @item skip file @r{[}@var{filename}@r{]} | |
5406 | After running this command, any function whose source lives in @var{filename} | |
5407 | will be skipped over when stepping. | |
5408 | ||
5409 | If you do not specify @var{filename}, functions whose source lives in the file | |
5410 | you're currently debugging will be skipped. | |
5411 | @end table | |
5412 | ||
5413 | Skips can be listed, deleted, disabled, and enabled, much like breakpoints. | |
5414 | These are the commands for managing your list of skips: | |
5415 | ||
5416 | @table @code | |
5417 | @kindex info skip | |
5418 | @item info skip @r{[}@var{range}@r{]} | |
5419 | Print details about the specified skip(s). If @var{range} is not specified, | |
5420 | print a table with details about all functions and files marked for skipping. | |
5421 | @code{info skip} prints the following information about each skip: | |
5422 | ||
5423 | @table @emph | |
5424 | @item Identifier | |
5425 | A number identifying this skip. | |
5426 | @item Type | |
5427 | The type of this skip, either @samp{function} or @samp{file}. | |
5428 | @item Enabled or Disabled | |
5429 | Enabled skips are marked with @samp{y}. Disabled skips are marked with @samp{n}. | |
5430 | @item Address | |
5431 | For function skips, this column indicates the address in memory of the function | |
5432 | being skipped. If you've set a function skip on a function which has not yet | |
5433 | been loaded, this field will contain @samp{<PENDING>}. Once a shared library | |
5434 | which has the function is loaded, @code{info skip} will show the function's | |
5435 | address here. | |
5436 | @item What | |
5437 | For file skips, this field contains the filename being skipped. For functions | |
5438 | skips, this field contains the function name and its line number in the file | |
5439 | where it is defined. | |
5440 | @end table | |
5441 | ||
5442 | @kindex skip delete | |
5443 | @item skip delete @r{[}@var{range}@r{]} | |
5444 | Delete the specified skip(s). If @var{range} is not specified, delete all | |
5445 | skips. | |
5446 | ||
5447 | @kindex skip enable | |
5448 | @item skip enable @r{[}@var{range}@r{]} | |
5449 | Enable the specified skip(s). If @var{range} is not specified, enable all | |
5450 | skips. | |
5451 | ||
5452 | @kindex skip disable | |
5453 | @item skip disable @r{[}@var{range}@r{]} | |
5454 | Disable the specified skip(s). If @var{range} is not specified, disable all | |
5455 | skips. | |
5456 | ||
5457 | @end table | |
5458 | ||
6d2ebf8b | 5459 | @node Signals |
c906108c SS |
5460 | @section Signals |
5461 | @cindex signals | |
5462 | ||
5463 | A signal is an asynchronous event that can happen in a program. The | |
5464 | operating system defines the possible kinds of signals, and gives each | |
5465 | kind a name and a number. For example, in Unix @code{SIGINT} is the | |
c8aa23ab | 5466 | signal a program gets when you type an interrupt character (often @kbd{Ctrl-c}); |
c906108c SS |
5467 | @code{SIGSEGV} is the signal a program gets from referencing a place in |
5468 | memory far away from all the areas in use; @code{SIGALRM} occurs when | |
5469 | the alarm clock timer goes off (which happens only if your program has | |
5470 | requested an alarm). | |
5471 | ||
5472 | @cindex fatal signals | |
5473 | Some signals, including @code{SIGALRM}, are a normal part of the | |
5474 | functioning of your program. Others, such as @code{SIGSEGV}, indicate | |
d4f3574e | 5475 | errors; these signals are @dfn{fatal} (they kill your program immediately) if the |
c906108c SS |
5476 | program has not specified in advance some other way to handle the signal. |
5477 | @code{SIGINT} does not indicate an error in your program, but it is normally | |
5478 | fatal so it can carry out the purpose of the interrupt: to kill the program. | |
5479 | ||
5480 | @value{GDBN} has the ability to detect any occurrence of a signal in your | |
5481 | program. You can tell @value{GDBN} in advance what to do for each kind of | |
5482 | signal. | |
5483 | ||
5484 | @cindex handling signals | |
24f93129 EZ |
5485 | Normally, @value{GDBN} is set up to let the non-erroneous signals like |
5486 | @code{SIGALRM} be silently passed to your program | |
5487 | (so as not to interfere with their role in the program's functioning) | |
c906108c SS |
5488 | but to stop your program immediately whenever an error signal happens. |
5489 | You can change these settings with the @code{handle} command. | |
5490 | ||
5491 | @table @code | |
5492 | @kindex info signals | |
09d4efe1 | 5493 | @kindex info handle |
c906108c | 5494 | @item info signals |
96a2c332 | 5495 | @itemx info handle |
c906108c SS |
5496 | Print a table of all the kinds of signals and how @value{GDBN} has been told to |
5497 | handle each one. You can use this to see the signal numbers of all | |
5498 | the defined types of signals. | |
5499 | ||
45ac1734 EZ |
5500 | @item info signals @var{sig} |
5501 | Similar, but print information only about the specified signal number. | |
5502 | ||
d4f3574e | 5503 | @code{info handle} is an alias for @code{info signals}. |
c906108c | 5504 | |
ab04a2af TT |
5505 | @item catch signal @r{[}@var{signal}@dots{} @r{|} @samp{all}@r{]} |
5506 | Set a catchpoint for the indicated signals. @xref{Set Catchpoints}, | |
5507 | for details about this command. | |
5508 | ||
c906108c | 5509 | @kindex handle |
45ac1734 | 5510 | @item handle @var{signal} @r{[}@var{keywords}@dots{}@r{]} |
697aa1b7 | 5511 | Change the way @value{GDBN} handles signal @var{signal}. The @var{signal} |
5ece1a18 | 5512 | can be the number of a signal or its name (with or without the |
24f93129 | 5513 | @samp{SIG} at the beginning); a list of signal numbers of the form |
5ece1a18 | 5514 | @samp{@var{low}-@var{high}}; or the word @samp{all}, meaning all the |
45ac1734 EZ |
5515 | known signals. Optional arguments @var{keywords}, described below, |
5516 | say what change to make. | |
c906108c SS |
5517 | @end table |
5518 | ||
5519 | @c @group | |
5520 | The keywords allowed by the @code{handle} command can be abbreviated. | |
5521 | Their full names are: | |
5522 | ||
5523 | @table @code | |
5524 | @item nostop | |
5525 | @value{GDBN} should not stop your program when this signal happens. It may | |
5526 | still print a message telling you that the signal has come in. | |
5527 | ||
5528 | @item stop | |
5529 | @value{GDBN} should stop your program when this signal happens. This implies | |
5530 | the @code{print} keyword as well. | |
5531 | ||
5532 | @item print | |
5533 | @value{GDBN} should print a message when this signal happens. | |
5534 | ||
5535 | @item noprint | |
5536 | @value{GDBN} should not mention the occurrence of the signal at all. This | |
5537 | implies the @code{nostop} keyword as well. | |
5538 | ||
5539 | @item pass | |
5ece1a18 | 5540 | @itemx noignore |
c906108c SS |
5541 | @value{GDBN} should allow your program to see this signal; your program |
5542 | can handle the signal, or else it may terminate if the signal is fatal | |
5ece1a18 | 5543 | and not handled. @code{pass} and @code{noignore} are synonyms. |
c906108c SS |
5544 | |
5545 | @item nopass | |
5ece1a18 | 5546 | @itemx ignore |
c906108c | 5547 | @value{GDBN} should not allow your program to see this signal. |
5ece1a18 | 5548 | @code{nopass} and @code{ignore} are synonyms. |
c906108c SS |
5549 | @end table |
5550 | @c @end group | |
5551 | ||
d4f3574e SS |
5552 | When a signal stops your program, the signal is not visible to the |
5553 | program until you | |
c906108c SS |
5554 | continue. Your program sees the signal then, if @code{pass} is in |
5555 | effect for the signal in question @emph{at that time}. In other words, | |
5556 | after @value{GDBN} reports a signal, you can use the @code{handle} | |
5557 | command with @code{pass} or @code{nopass} to control whether your | |
5558 | program sees that signal when you continue. | |
5559 | ||
24f93129 EZ |
5560 | The default is set to @code{nostop}, @code{noprint}, @code{pass} for |
5561 | non-erroneous signals such as @code{SIGALRM}, @code{SIGWINCH} and | |
5562 | @code{SIGCHLD}, and to @code{stop}, @code{print}, @code{pass} for the | |
5563 | erroneous signals. | |
5564 | ||
c906108c SS |
5565 | You can also use the @code{signal} command to prevent your program from |
5566 | seeing a signal, or cause it to see a signal it normally would not see, | |
5567 | or to give it any signal at any time. For example, if your program stopped | |
5568 | due to some sort of memory reference error, you might store correct | |
5569 | values into the erroneous variables and continue, hoping to see more | |
5570 | execution; but your program would probably terminate immediately as | |
5571 | a result of the fatal signal once it saw the signal. To prevent this, | |
5572 | you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your | |
79a6e687 | 5573 | Program a Signal}. |
c906108c | 5574 | |
4aa995e1 PA |
5575 | @cindex extra signal information |
5576 | @anchor{extra signal information} | |
5577 | ||
5578 | On some targets, @value{GDBN} can inspect extra signal information | |
5579 | associated with the intercepted signal, before it is actually | |
5580 | delivered to the program being debugged. This information is exported | |
5581 | by the convenience variable @code{$_siginfo}, and consists of data | |
5582 | that is passed by the kernel to the signal handler at the time of the | |
5583 | receipt of a signal. The data type of the information itself is | |
5584 | target dependent. You can see the data type using the @code{ptype | |
5585 | $_siginfo} command. On Unix systems, it typically corresponds to the | |
5586 | standard @code{siginfo_t} type, as defined in the @file{signal.h} | |
5587 | system header. | |
5588 | ||
5589 | Here's an example, on a @sc{gnu}/Linux system, printing the stray | |
5590 | referenced address that raised a segmentation fault. | |
5591 | ||
5592 | @smallexample | |
5593 | @group | |
5594 | (@value{GDBP}) continue | |
5595 | Program received signal SIGSEGV, Segmentation fault. | |
5596 | 0x0000000000400766 in main () | |
5597 | 69 *(int *)p = 0; | |
5598 | (@value{GDBP}) ptype $_siginfo | |
5599 | type = struct @{ | |
5600 | int si_signo; | |
5601 | int si_errno; | |
5602 | int si_code; | |
5603 | union @{ | |
5604 | int _pad[28]; | |
5605 | struct @{...@} _kill; | |
5606 | struct @{...@} _timer; | |
5607 | struct @{...@} _rt; | |
5608 | struct @{...@} _sigchld; | |
5609 | struct @{...@} _sigfault; | |
5610 | struct @{...@} _sigpoll; | |
5611 | @} _sifields; | |
5612 | @} | |
5613 | (@value{GDBP}) ptype $_siginfo._sifields._sigfault | |
5614 | type = struct @{ | |
5615 | void *si_addr; | |
5616 | @} | |
5617 | (@value{GDBP}) p $_siginfo._sifields._sigfault.si_addr | |
5618 | $1 = (void *) 0x7ffff7ff7000 | |
5619 | @end group | |
5620 | @end smallexample | |
5621 | ||
5622 | Depending on target support, @code{$_siginfo} may also be writable. | |
5623 | ||
6d2ebf8b | 5624 | @node Thread Stops |
79a6e687 | 5625 | @section Stopping and Starting Multi-thread Programs |
c906108c | 5626 | |
0606b73b SL |
5627 | @cindex stopped threads |
5628 | @cindex threads, stopped | |
5629 | ||
5630 | @cindex continuing threads | |
5631 | @cindex threads, continuing | |
5632 | ||
5633 | @value{GDBN} supports debugging programs with multiple threads | |
5634 | (@pxref{Threads,, Debugging Programs with Multiple Threads}). There | |
5635 | are two modes of controlling execution of your program within the | |
5636 | debugger. In the default mode, referred to as @dfn{all-stop mode}, | |
5637 | when any thread in your program stops (for example, at a breakpoint | |
5638 | or while being stepped), all other threads in the program are also stopped by | |
5639 | @value{GDBN}. On some targets, @value{GDBN} also supports | |
5640 | @dfn{non-stop mode}, in which other threads can continue to run freely while | |
5641 | you examine the stopped thread in the debugger. | |
5642 | ||
5643 | @menu | |
5644 | * All-Stop Mode:: All threads stop when GDB takes control | |
5645 | * Non-Stop Mode:: Other threads continue to execute | |
5646 | * Background Execution:: Running your program asynchronously | |
5647 | * Thread-Specific Breakpoints:: Controlling breakpoints | |
5648 | * Interrupted System Calls:: GDB may interfere with system calls | |
d914c394 | 5649 | * Observer Mode:: GDB does not alter program behavior |
0606b73b SL |
5650 | @end menu |
5651 | ||
5652 | @node All-Stop Mode | |
5653 | @subsection All-Stop Mode | |
5654 | ||
5655 | @cindex all-stop mode | |
5656 | ||
5657 | In all-stop mode, whenever your program stops under @value{GDBN} for any reason, | |
5658 | @emph{all} threads of execution stop, not just the current thread. This | |
5659 | allows you to examine the overall state of the program, including | |
5660 | switching between threads, without worrying that things may change | |
5661 | underfoot. | |
5662 | ||
5663 | Conversely, whenever you restart the program, @emph{all} threads start | |
5664 | executing. @emph{This is true even when single-stepping} with commands | |
5665 | like @code{step} or @code{next}. | |
5666 | ||
5667 | In particular, @value{GDBN} cannot single-step all threads in lockstep. | |
5668 | Since thread scheduling is up to your debugging target's operating | |
5669 | system (not controlled by @value{GDBN}), other threads may | |
5670 | execute more than one statement while the current thread completes a | |
5671 | single step. Moreover, in general other threads stop in the middle of a | |
5672 | statement, rather than at a clean statement boundary, when the program | |
5673 | stops. | |
5674 | ||
5675 | You might even find your program stopped in another thread after | |
5676 | continuing or even single-stepping. This happens whenever some other | |
5677 | thread runs into a breakpoint, a signal, or an exception before the | |
5678 | first thread completes whatever you requested. | |
5679 | ||
5680 | @cindex automatic thread selection | |
5681 | @cindex switching threads automatically | |
5682 | @cindex threads, automatic switching | |
5683 | Whenever @value{GDBN} stops your program, due to a breakpoint or a | |
5684 | signal, it automatically selects the thread where that breakpoint or | |
5685 | signal happened. @value{GDBN} alerts you to the context switch with a | |
5686 | message such as @samp{[Switching to Thread @var{n}]} to identify the | |
5687 | thread. | |
5688 | ||
5689 | On some OSes, you can modify @value{GDBN}'s default behavior by | |
5690 | locking the OS scheduler to allow only a single thread to run. | |
5691 | ||
5692 | @table @code | |
5693 | @item set scheduler-locking @var{mode} | |
5694 | @cindex scheduler locking mode | |
5695 | @cindex lock scheduler | |
5696 | Set the scheduler locking mode. If it is @code{off}, then there is no | |
5697 | locking and any thread may run at any time. If @code{on}, then only the | |
5698 | current thread may run when the inferior is resumed. The @code{step} | |
5699 | mode optimizes for single-stepping; it prevents other threads | |
5700 | from preempting the current thread while you are stepping, so that | |
5701 | the focus of debugging does not change unexpectedly. | |
5702 | Other threads only rarely (or never) get a chance to run | |
5703 | when you step. They are more likely to run when you @samp{next} over a | |
5704 | function call, and they are completely free to run when you use commands | |
5705 | like @samp{continue}, @samp{until}, or @samp{finish}. However, unless another | |
5706 | thread hits a breakpoint during its timeslice, @value{GDBN} does not change | |
5707 | the current thread away from the thread that you are debugging. | |
5708 | ||
5709 | @item show scheduler-locking | |
5710 | Display the current scheduler locking mode. | |
5711 | @end table | |
5712 | ||
d4db2f36 PA |
5713 | @cindex resume threads of multiple processes simultaneously |
5714 | By default, when you issue one of the execution commands such as | |
5715 | @code{continue}, @code{next} or @code{step}, @value{GDBN} allows only | |
5716 | threads of the current inferior to run. For example, if @value{GDBN} | |
5717 | is attached to two inferiors, each with two threads, the | |
5718 | @code{continue} command resumes only the two threads of the current | |
5719 | inferior. This is useful, for example, when you debug a program that | |
5720 | forks and you want to hold the parent stopped (so that, for instance, | |
5721 | it doesn't run to exit), while you debug the child. In other | |
5722 | situations, you may not be interested in inspecting the current state | |
5723 | of any of the processes @value{GDBN} is attached to, and you may want | |
5724 | to resume them all until some breakpoint is hit. In the latter case, | |
5725 | you can instruct @value{GDBN} to allow all threads of all the | |
5726 | inferiors to run with the @w{@code{set schedule-multiple}} command. | |
5727 | ||
5728 | @table @code | |
5729 | @kindex set schedule-multiple | |
5730 | @item set schedule-multiple | |
5731 | Set the mode for allowing threads of multiple processes to be resumed | |
5732 | when an execution command is issued. When @code{on}, all threads of | |
5733 | all processes are allowed to run. When @code{off}, only the threads | |
5734 | of the current process are resumed. The default is @code{off}. The | |
5735 | @code{scheduler-locking} mode takes precedence when set to @code{on}, | |
5736 | or while you are stepping and set to @code{step}. | |
5737 | ||
5738 | @item show schedule-multiple | |
5739 | Display the current mode for resuming the execution of threads of | |
5740 | multiple processes. | |
5741 | @end table | |
5742 | ||
0606b73b SL |
5743 | @node Non-Stop Mode |
5744 | @subsection Non-Stop Mode | |
5745 | ||
5746 | @cindex non-stop mode | |
5747 | ||
5748 | @c This section is really only a place-holder, and needs to be expanded | |
97d8f0ee | 5749 | @c with more details. |
0606b73b SL |
5750 | |
5751 | For some multi-threaded targets, @value{GDBN} supports an optional | |
5752 | mode of operation in which you can examine stopped program threads in | |
5753 | the debugger while other threads continue to execute freely. This | |
97d8f0ee DE |
5754 | minimizes intrusion when debugging live systems, such as programs |
5755 | where some threads have real-time constraints or must continue to | |
0606b73b SL |
5756 | respond to external events. This is referred to as @dfn{non-stop} mode. |
5757 | ||
5758 | In non-stop mode, when a thread stops to report a debugging event, | |
5759 | @emph{only} that thread is stopped; @value{GDBN} does not stop other | |
5760 | threads as well, in contrast to the all-stop mode behavior. Additionally, | |
5761 | execution commands such as @code{continue} and @code{step} apply by default | |
5762 | only to the current thread in non-stop mode, rather than all threads as | |
5763 | in all-stop mode. This allows you to control threads explicitly in | |
97d8f0ee | 5764 | ways that are not possible in all-stop mode --- for example, stepping |
0606b73b | 5765 | one thread while allowing others to run freely, stepping |
97d8f0ee | 5766 | one thread while holding all others stopped, or stepping several threads |
0606b73b SL |
5767 | independently and simultaneously. |
5768 | ||
5769 | To enter non-stop mode, use this sequence of commands before you run | |
5770 | or attach to your program: | |
5771 | ||
0606b73b | 5772 | @smallexample |
0606b73b SL |
5773 | # If using the CLI, pagination breaks non-stop. |
5774 | set pagination off | |
5775 | ||
5776 | # Finally, turn it on! | |
5777 | set non-stop on | |
5778 | @end smallexample | |
5779 | ||
5780 | You can use these commands to manipulate the non-stop mode setting: | |
5781 | ||
5782 | @table @code | |
5783 | @kindex set non-stop | |
5784 | @item set non-stop on | |
5785 | Enable selection of non-stop mode. | |
5786 | @item set non-stop off | |
5787 | Disable selection of non-stop mode. | |
5788 | @kindex show non-stop | |
5789 | @item show non-stop | |
5790 | Show the current non-stop enablement setting. | |
5791 | @end table | |
5792 | ||
5793 | Note these commands only reflect whether non-stop mode is enabled, | |
97d8f0ee | 5794 | not whether the currently-executing program is being run in non-stop mode. |
0606b73b | 5795 | In particular, the @code{set non-stop} preference is only consulted when |
97d8f0ee | 5796 | @value{GDBN} starts or connects to the target program, and it is generally |
0606b73b SL |
5797 | not possible to switch modes once debugging has started. Furthermore, |
5798 | since not all targets support non-stop mode, even when you have enabled | |
5799 | non-stop mode, @value{GDBN} may still fall back to all-stop operation by | |
5800 | default. | |
5801 | ||
5802 | In non-stop mode, all execution commands apply only to the current thread | |
97d8f0ee | 5803 | by default. That is, @code{continue} only continues one thread. |
0606b73b SL |
5804 | To continue all threads, issue @code{continue -a} or @code{c -a}. |
5805 | ||
97d8f0ee | 5806 | You can use @value{GDBN}'s background execution commands |
0606b73b | 5807 | (@pxref{Background Execution}) to run some threads in the background |
97d8f0ee | 5808 | while you continue to examine or step others from @value{GDBN}. |
0606b73b SL |
5809 | The MI execution commands (@pxref{GDB/MI Program Execution}) are |
5810 | always executed asynchronously in non-stop mode. | |
5811 | ||
5812 | Suspending execution is done with the @code{interrupt} command when | |
97d8f0ee DE |
5813 | running in the background, or @kbd{Ctrl-c} during foreground execution. |
5814 | In all-stop mode, this stops the whole process; | |
5815 | but in non-stop mode the interrupt applies only to the current thread. | |
0606b73b SL |
5816 | To stop the whole program, use @code{interrupt -a}. |
5817 | ||
5818 | Other execution commands do not currently support the @code{-a} option. | |
5819 | ||
5820 | In non-stop mode, when a thread stops, @value{GDBN} doesn't automatically make | |
5821 | that thread current, as it does in all-stop mode. This is because the | |
97d8f0ee | 5822 | thread stop notifications are asynchronous with respect to @value{GDBN}'s |
0606b73b SL |
5823 | command interpreter, and it would be confusing if @value{GDBN} unexpectedly |
5824 | changed to a different thread just as you entered a command to operate on the | |
5825 | previously current thread. | |
5826 | ||
5827 | @node Background Execution | |
5828 | @subsection Background Execution | |
5829 | ||
5830 | @cindex foreground execution | |
5831 | @cindex background execution | |
5832 | @cindex asynchronous execution | |
5833 | @cindex execution, foreground, background and asynchronous | |
5834 | ||
5835 | @value{GDBN}'s execution commands have two variants: the normal | |
5836 | foreground (synchronous) behavior, and a background | |
97d8f0ee | 5837 | (asynchronous) behavior. In foreground execution, @value{GDBN} waits for |
0606b73b SL |
5838 | the program to report that some thread has stopped before prompting for |
5839 | another command. In background execution, @value{GDBN} immediately gives | |
5840 | a command prompt so that you can issue other commands while your program runs. | |
5841 | ||
32fc0df9 PA |
5842 | If the target doesn't support async mode, @value{GDBN} issues an error |
5843 | message if you attempt to use the background execution commands. | |
5844 | ||
0606b73b SL |
5845 | To specify background execution, add a @code{&} to the command. For example, |
5846 | the background form of the @code{continue} command is @code{continue&}, or | |
5847 | just @code{c&}. The execution commands that accept background execution | |
5848 | are: | |
5849 | ||
5850 | @table @code | |
5851 | @kindex run& | |
5852 | @item run | |
5853 | @xref{Starting, , Starting your Program}. | |
5854 | ||
5855 | @item attach | |
5856 | @kindex attach& | |
5857 | @xref{Attach, , Debugging an Already-running Process}. | |
5858 | ||
5859 | @item step | |
5860 | @kindex step& | |
5861 | @xref{Continuing and Stepping, step}. | |
5862 | ||
5863 | @item stepi | |
5864 | @kindex stepi& | |
5865 | @xref{Continuing and Stepping, stepi}. | |
5866 | ||
5867 | @item next | |
5868 | @kindex next& | |
5869 | @xref{Continuing and Stepping, next}. | |
5870 | ||
7ce58dd2 DE |
5871 | @item nexti |
5872 | @kindex nexti& | |
5873 | @xref{Continuing and Stepping, nexti}. | |
5874 | ||
0606b73b SL |
5875 | @item continue |
5876 | @kindex continue& | |
5877 | @xref{Continuing and Stepping, continue}. | |
5878 | ||
5879 | @item finish | |
5880 | @kindex finish& | |
5881 | @xref{Continuing and Stepping, finish}. | |
5882 | ||
5883 | @item until | |
5884 | @kindex until& | |
5885 | @xref{Continuing and Stepping, until}. | |
5886 | ||
5887 | @end table | |
5888 | ||
5889 | Background execution is especially useful in conjunction with non-stop | |
5890 | mode for debugging programs with multiple threads; see @ref{Non-Stop Mode}. | |
5891 | However, you can also use these commands in the normal all-stop mode with | |
5892 | the restriction that you cannot issue another execution command until the | |
5893 | previous one finishes. Examples of commands that are valid in all-stop | |
5894 | mode while the program is running include @code{help} and @code{info break}. | |
5895 | ||
5896 | You can interrupt your program while it is running in the background by | |
5897 | using the @code{interrupt} command. | |
5898 | ||
5899 | @table @code | |
5900 | @kindex interrupt | |
5901 | @item interrupt | |
5902 | @itemx interrupt -a | |
5903 | ||
97d8f0ee | 5904 | Suspend execution of the running program. In all-stop mode, |
0606b73b | 5905 | @code{interrupt} stops the whole process, but in non-stop mode, it stops |
97d8f0ee | 5906 | only the current thread. To stop the whole program in non-stop mode, |
0606b73b SL |
5907 | use @code{interrupt -a}. |
5908 | @end table | |
5909 | ||
0606b73b SL |
5910 | @node Thread-Specific Breakpoints |
5911 | @subsection Thread-Specific Breakpoints | |
5912 | ||
c906108c | 5913 | When your program has multiple threads (@pxref{Threads,, Debugging |
79a6e687 | 5914 | Programs with Multiple Threads}), you can choose whether to set |
c906108c SS |
5915 | breakpoints on all threads, or on a particular thread. |
5916 | ||
5917 | @table @code | |
5918 | @cindex breakpoints and threads | |
5919 | @cindex thread breakpoints | |
5920 | @kindex break @dots{} thread @var{threadno} | |
5921 | @item break @var{linespec} thread @var{threadno} | |
5922 | @itemx break @var{linespec} thread @var{threadno} if @dots{} | |
5923 | @var{linespec} specifies source lines; there are several ways of | |
2a25a5ba EZ |
5924 | writing them (@pxref{Specify Location}), but the effect is always to |
5925 | specify some source line. | |
c906108c SS |
5926 | |
5927 | Use the qualifier @samp{thread @var{threadno}} with a breakpoint command | |
5928 | to specify that you only want @value{GDBN} to stop the program when a | |
697aa1b7 EZ |
5929 | particular thread reaches this breakpoint. The @var{threadno} specifier |
5930 | is one of the numeric thread identifiers assigned by @value{GDBN}, shown | |
5931 | in the first column of the @samp{info threads} display. | |
c906108c SS |
5932 | |
5933 | If you do not specify @samp{thread @var{threadno}} when you set a | |
5934 | breakpoint, the breakpoint applies to @emph{all} threads of your | |
5935 | program. | |
5936 | ||
5937 | You can use the @code{thread} qualifier on conditional breakpoints as | |
b6199126 DJ |
5938 | well; in this case, place @samp{thread @var{threadno}} before or |
5939 | after the breakpoint condition, like this: | |
c906108c SS |
5940 | |
5941 | @smallexample | |
2df3850c | 5942 | (@value{GDBP}) break frik.c:13 thread 28 if bartab > lim |
c906108c SS |
5943 | @end smallexample |
5944 | ||
5945 | @end table | |
5946 | ||
f4fb82a1 PA |
5947 | Thread-specific breakpoints are automatically deleted when |
5948 | @value{GDBN} detects the corresponding thread is no longer in the | |
5949 | thread list. For example: | |
5950 | ||
5951 | @smallexample | |
5952 | (@value{GDBP}) c | |
5953 | Thread-specific breakpoint 3 deleted - thread 28 no longer in the thread list. | |
5954 | @end smallexample | |
5955 | ||
5956 | There are several ways for a thread to disappear, such as a regular | |
5957 | thread exit, but also when you detach from the process with the | |
5958 | @code{detach} command (@pxref{Attach, ,Debugging an Already-running | |
5959 | Process}), or if @value{GDBN} loses the remote connection | |
5960 | (@pxref{Remote Debugging}), etc. Note that with some targets, | |
5961 | @value{GDBN} is only able to detect a thread has exited when the user | |
5962 | explictly asks for the thread list with the @code{info threads} | |
5963 | command. | |
5964 | ||
0606b73b SL |
5965 | @node Interrupted System Calls |
5966 | @subsection Interrupted System Calls | |
c906108c | 5967 | |
36d86913 MC |
5968 | @cindex thread breakpoints and system calls |
5969 | @cindex system calls and thread breakpoints | |
5970 | @cindex premature return from system calls | |
0606b73b SL |
5971 | There is an unfortunate side effect when using @value{GDBN} to debug |
5972 | multi-threaded programs. If one thread stops for a | |
36d86913 MC |
5973 | breakpoint, or for some other reason, and another thread is blocked in a |
5974 | system call, then the system call may return prematurely. This is a | |
5975 | consequence of the interaction between multiple threads and the signals | |
5976 | that @value{GDBN} uses to implement breakpoints and other events that | |
5977 | stop execution. | |
5978 | ||
5979 | To handle this problem, your program should check the return value of | |
5980 | each system call and react appropriately. This is good programming | |
5981 | style anyways. | |
5982 | ||
5983 | For example, do not write code like this: | |
5984 | ||
5985 | @smallexample | |
5986 | sleep (10); | |
5987 | @end smallexample | |
5988 | ||
5989 | The call to @code{sleep} will return early if a different thread stops | |
5990 | at a breakpoint or for some other reason. | |
5991 | ||
5992 | Instead, write this: | |
5993 | ||
5994 | @smallexample | |
5995 | int unslept = 10; | |
5996 | while (unslept > 0) | |
5997 | unslept = sleep (unslept); | |
5998 | @end smallexample | |
5999 | ||
6000 | A system call is allowed to return early, so the system is still | |
6001 | conforming to its specification. But @value{GDBN} does cause your | |
6002 | multi-threaded program to behave differently than it would without | |
6003 | @value{GDBN}. | |
6004 | ||
6005 | Also, @value{GDBN} uses internal breakpoints in the thread library to | |
6006 | monitor certain events such as thread creation and thread destruction. | |
6007 | When such an event happens, a system call in another thread may return | |
6008 | prematurely, even though your program does not appear to stop. | |
6009 | ||
d914c394 SS |
6010 | @node Observer Mode |
6011 | @subsection Observer Mode | |
6012 | ||
6013 | If you want to build on non-stop mode and observe program behavior | |
6014 | without any chance of disruption by @value{GDBN}, you can set | |
6015 | variables to disable all of the debugger's attempts to modify state, | |
6016 | whether by writing memory, inserting breakpoints, etc. These operate | |
6017 | at a low level, intercepting operations from all commands. | |
6018 | ||
6019 | When all of these are set to @code{off}, then @value{GDBN} is said to | |
6020 | be @dfn{observer mode}. As a convenience, the variable | |
6021 | @code{observer} can be set to disable these, plus enable non-stop | |
6022 | mode. | |
6023 | ||
6024 | Note that @value{GDBN} will not prevent you from making nonsensical | |
6025 | combinations of these settings. For instance, if you have enabled | |
6026 | @code{may-insert-breakpoints} but disabled @code{may-write-memory}, | |
6027 | then breakpoints that work by writing trap instructions into the code | |
6028 | stream will still not be able to be placed. | |
6029 | ||
6030 | @table @code | |
6031 | ||
6032 | @kindex observer | |
6033 | @item set observer on | |
6034 | @itemx set observer off | |
6035 | When set to @code{on}, this disables all the permission variables | |
6036 | below (except for @code{insert-fast-tracepoints}), plus enables | |
6037 | non-stop debugging. Setting this to @code{off} switches back to | |
6038 | normal debugging, though remaining in non-stop mode. | |
6039 | ||
6040 | @item show observer | |
6041 | Show whether observer mode is on or off. | |
6042 | ||
6043 | @kindex may-write-registers | |
6044 | @item set may-write-registers on | |
6045 | @itemx set may-write-registers off | |
6046 | This controls whether @value{GDBN} will attempt to alter the values of | |
6047 | registers, such as with assignment expressions in @code{print}, or the | |
6048 | @code{jump} command. It defaults to @code{on}. | |
6049 | ||
6050 | @item show may-write-registers | |
6051 | Show the current permission to write registers. | |
6052 | ||
6053 | @kindex may-write-memory | |
6054 | @item set may-write-memory on | |
6055 | @itemx set may-write-memory off | |
6056 | This controls whether @value{GDBN} will attempt to alter the contents | |
6057 | of memory, such as with assignment expressions in @code{print}. It | |
6058 | defaults to @code{on}. | |
6059 | ||
6060 | @item show may-write-memory | |
6061 | Show the current permission to write memory. | |
6062 | ||
6063 | @kindex may-insert-breakpoints | |
6064 | @item set may-insert-breakpoints on | |
6065 | @itemx set may-insert-breakpoints off | |
6066 | This controls whether @value{GDBN} will attempt to insert breakpoints. | |
6067 | This affects all breakpoints, including internal breakpoints defined | |
6068 | by @value{GDBN}. It defaults to @code{on}. | |
6069 | ||
6070 | @item show may-insert-breakpoints | |
6071 | Show the current permission to insert breakpoints. | |
6072 | ||
6073 | @kindex may-insert-tracepoints | |
6074 | @item set may-insert-tracepoints on | |
6075 | @itemx set may-insert-tracepoints off | |
6076 | This controls whether @value{GDBN} will attempt to insert (regular) | |
6077 | tracepoints at the beginning of a tracing experiment. It affects only | |
6078 | non-fast tracepoints, fast tracepoints being under the control of | |
6079 | @code{may-insert-fast-tracepoints}. It defaults to @code{on}. | |
6080 | ||
6081 | @item show may-insert-tracepoints | |
6082 | Show the current permission to insert tracepoints. | |
6083 | ||
6084 | @kindex may-insert-fast-tracepoints | |
6085 | @item set may-insert-fast-tracepoints on | |
6086 | @itemx set may-insert-fast-tracepoints off | |
6087 | This controls whether @value{GDBN} will attempt to insert fast | |
6088 | tracepoints at the beginning of a tracing experiment. It affects only | |
6089 | fast tracepoints, regular (non-fast) tracepoints being under the | |
6090 | control of @code{may-insert-tracepoints}. It defaults to @code{on}. | |
6091 | ||
6092 | @item show may-insert-fast-tracepoints | |
6093 | Show the current permission to insert fast tracepoints. | |
6094 | ||
6095 | @kindex may-interrupt | |
6096 | @item set may-interrupt on | |
6097 | @itemx set may-interrupt off | |
6098 | This controls whether @value{GDBN} will attempt to interrupt or stop | |
6099 | program execution. When this variable is @code{off}, the | |
6100 | @code{interrupt} command will have no effect, nor will | |
6101 | @kbd{Ctrl-c}. It defaults to @code{on}. | |
6102 | ||
6103 | @item show may-interrupt | |
6104 | Show the current permission to interrupt or stop the program. | |
6105 | ||
6106 | @end table | |
c906108c | 6107 | |
bacec72f MS |
6108 | @node Reverse Execution |
6109 | @chapter Running programs backward | |
6110 | @cindex reverse execution | |
6111 | @cindex running programs backward | |
6112 | ||
6113 | When you are debugging a program, it is not unusual to realize that | |
6114 | you have gone too far, and some event of interest has already happened. | |
6115 | If the target environment supports it, @value{GDBN} can allow you to | |
6116 | ``rewind'' the program by running it backward. | |
6117 | ||
6118 | A target environment that supports reverse execution should be able | |
6119 | to ``undo'' the changes in machine state that have taken place as the | |
6120 | program was executing normally. Variables, registers etc.@: should | |
6121 | revert to their previous values. Obviously this requires a great | |
6122 | deal of sophistication on the part of the target environment; not | |
6123 | all target environments can support reverse execution. | |
6124 | ||
6125 | When a program is executed in reverse, the instructions that | |
6126 | have most recently been executed are ``un-executed'', in reverse | |
6127 | order. The program counter runs backward, following the previous | |
6128 | thread of execution in reverse. As each instruction is ``un-executed'', | |
6129 | the values of memory and/or registers that were changed by that | |
6130 | instruction are reverted to their previous states. After executing | |
6131 | a piece of source code in reverse, all side effects of that code | |
6132 | should be ``undone'', and all variables should be returned to their | |
6133 | prior values@footnote{ | |
6134 | Note that some side effects are easier to undo than others. For instance, | |
6135 | memory and registers are relatively easy, but device I/O is hard. Some | |
6136 | targets may be able undo things like device I/O, and some may not. | |
6137 | ||
6138 | The contract between @value{GDBN} and the reverse executing target | |
6139 | requires only that the target do something reasonable when | |
6140 | @value{GDBN} tells it to execute backwards, and then report the | |
6141 | results back to @value{GDBN}. Whatever the target reports back to | |
6142 | @value{GDBN}, @value{GDBN} will report back to the user. @value{GDBN} | |
6143 | assumes that the memory and registers that the target reports are in a | |
6144 | consistant state, but @value{GDBN} accepts whatever it is given. | |
6145 | }. | |
6146 | ||
6147 | If you are debugging in a target environment that supports | |
6148 | reverse execution, @value{GDBN} provides the following commands. | |
6149 | ||
6150 | @table @code | |
6151 | @kindex reverse-continue | |
6152 | @kindex rc @r{(@code{reverse-continue})} | |
6153 | @item reverse-continue @r{[}@var{ignore-count}@r{]} | |
6154 | @itemx rc @r{[}@var{ignore-count}@r{]} | |
6155 | Beginning at the point where your program last stopped, start executing | |
6156 | in reverse. Reverse execution will stop for breakpoints and synchronous | |
6157 | exceptions (signals), just like normal execution. Behavior of | |
6158 | asynchronous signals depends on the target environment. | |
6159 | ||
6160 | @kindex reverse-step | |
6161 | @kindex rs @r{(@code{step})} | |
6162 | @item reverse-step @r{[}@var{count}@r{]} | |
6163 | Run the program backward until control reaches the start of a | |
6164 | different source line; then stop it, and return control to @value{GDBN}. | |
6165 | ||
6166 | Like the @code{step} command, @code{reverse-step} will only stop | |
6167 | at the beginning of a source line. It ``un-executes'' the previously | |
6168 | executed source line. If the previous source line included calls to | |
6169 | debuggable functions, @code{reverse-step} will step (backward) into | |
6170 | the called function, stopping at the beginning of the @emph{last} | |
6171 | statement in the called function (typically a return statement). | |
6172 | ||
6173 | Also, as with the @code{step} command, if non-debuggable functions are | |
6174 | called, @code{reverse-step} will run thru them backward without stopping. | |
6175 | ||
6176 | @kindex reverse-stepi | |
6177 | @kindex rsi @r{(@code{reverse-stepi})} | |
6178 | @item reverse-stepi @r{[}@var{count}@r{]} | |
6179 | Reverse-execute one machine instruction. Note that the instruction | |
6180 | to be reverse-executed is @emph{not} the one pointed to by the program | |
6181 | counter, but the instruction executed prior to that one. For instance, | |
6182 | if the last instruction was a jump, @code{reverse-stepi} will take you | |
6183 | back from the destination of the jump to the jump instruction itself. | |
6184 | ||
6185 | @kindex reverse-next | |
6186 | @kindex rn @r{(@code{reverse-next})} | |
6187 | @item reverse-next @r{[}@var{count}@r{]} | |
6188 | Run backward to the beginning of the previous line executed in | |
6189 | the current (innermost) stack frame. If the line contains function | |
6190 | calls, they will be ``un-executed'' without stopping. Starting from | |
6191 | the first line of a function, @code{reverse-next} will take you back | |
6192 | to the caller of that function, @emph{before} the function was called, | |
6193 | just as the normal @code{next} command would take you from the last | |
6194 | line of a function back to its return to its caller | |
16af530a | 6195 | @footnote{Unless the code is too heavily optimized.}. |
bacec72f MS |
6196 | |
6197 | @kindex reverse-nexti | |
6198 | @kindex rni @r{(@code{reverse-nexti})} | |
6199 | @item reverse-nexti @r{[}@var{count}@r{]} | |
6200 | Like @code{nexti}, @code{reverse-nexti} executes a single instruction | |
6201 | in reverse, except that called functions are ``un-executed'' atomically. | |
6202 | That is, if the previously executed instruction was a return from | |
540aa8e7 | 6203 | another function, @code{reverse-nexti} will continue to execute |
bacec72f MS |
6204 | in reverse until the call to that function (from the current stack |
6205 | frame) is reached. | |
6206 | ||
6207 | @kindex reverse-finish | |
6208 | @item reverse-finish | |
6209 | Just as the @code{finish} command takes you to the point where the | |
6210 | current function returns, @code{reverse-finish} takes you to the point | |
6211 | where it was called. Instead of ending up at the end of the current | |
6212 | function invocation, you end up at the beginning. | |
6213 | ||
6214 | @kindex set exec-direction | |
6215 | @item set exec-direction | |
6216 | Set the direction of target execution. | |
984359d2 | 6217 | @item set exec-direction reverse |
bacec72f MS |
6218 | @cindex execute forward or backward in time |
6219 | @value{GDBN} will perform all execution commands in reverse, until the | |
6220 | exec-direction mode is changed to ``forward''. Affected commands include | |
6221 | @code{step, stepi, next, nexti, continue, and finish}. The @code{return} | |
6222 | command cannot be used in reverse mode. | |
6223 | @item set exec-direction forward | |
6224 | @value{GDBN} will perform all execution commands in the normal fashion. | |
6225 | This is the default. | |
6226 | @end table | |
6227 | ||
c906108c | 6228 | |
a2311334 EZ |
6229 | @node Process Record and Replay |
6230 | @chapter Recording Inferior's Execution and Replaying It | |
53cc454a HZ |
6231 | @cindex process record and replay |
6232 | @cindex recording inferior's execution and replaying it | |
6233 | ||
8e05493c EZ |
6234 | On some platforms, @value{GDBN} provides a special @dfn{process record |
6235 | and replay} target that can record a log of the process execution, and | |
6236 | replay it later with both forward and reverse execution commands. | |
a2311334 EZ |
6237 | |
6238 | @cindex replay mode | |
6239 | When this target is in use, if the execution log includes the record | |
6240 | for the next instruction, @value{GDBN} will debug in @dfn{replay | |
6241 | mode}. In the replay mode, the inferior does not really execute code | |
6242 | instructions. Instead, all the events that normally happen during | |
6243 | code execution are taken from the execution log. While code is not | |
6244 | really executed in replay mode, the values of registers (including the | |
6245 | program counter register) and the memory of the inferior are still | |
8e05493c EZ |
6246 | changed as they normally would. Their contents are taken from the |
6247 | execution log. | |
a2311334 EZ |
6248 | |
6249 | @cindex record mode | |
6250 | If the record for the next instruction is not in the execution log, | |
6251 | @value{GDBN} will debug in @dfn{record mode}. In this mode, the | |
6252 | inferior executes normally, and @value{GDBN} records the execution log | |
6253 | for future replay. | |
6254 | ||
8e05493c EZ |
6255 | The process record and replay target supports reverse execution |
6256 | (@pxref{Reverse Execution}), even if the platform on which the | |
6257 | inferior runs does not. However, the reverse execution is limited in | |
6258 | this case by the range of the instructions recorded in the execution | |
6259 | log. In other words, reverse execution on platforms that don't | |
6260 | support it directly can only be done in the replay mode. | |
6261 | ||
6262 | When debugging in the reverse direction, @value{GDBN} will work in | |
6263 | replay mode as long as the execution log includes the record for the | |
6264 | previous instruction; otherwise, it will work in record mode, if the | |
6265 | platform supports reverse execution, or stop if not. | |
6266 | ||
a2311334 EZ |
6267 | For architecture environments that support process record and replay, |
6268 | @value{GDBN} provides the following commands: | |
53cc454a HZ |
6269 | |
6270 | @table @code | |
6271 | @kindex target record | |
59ea5688 MM |
6272 | @kindex target record-full |
6273 | @kindex target record-btrace | |
53cc454a | 6274 | @kindex record |
59ea5688 MM |
6275 | @kindex record full |
6276 | @kindex record btrace | |
53cc454a | 6277 | @kindex rec |
59ea5688 MM |
6278 | @kindex rec full |
6279 | @kindex rec btrace | |
6280 | @item record @var{method} | |
6281 | This command starts the process record and replay target. The | |
6282 | recording method can be specified as parameter. Without a parameter | |
6283 | the command uses the @code{full} recording method. The following | |
6284 | recording methods are available: | |
a2311334 | 6285 | |
59ea5688 MM |
6286 | @table @code |
6287 | @item full | |
6288 | Full record/replay recording using @value{GDBN}'s software record and | |
6289 | replay implementation. This method allows replaying and reverse | |
6290 | execution. | |
6291 | ||
6292 | @item btrace | |
52834460 MM |
6293 | Hardware-supported instruction recording. This method does not record |
6294 | data. Further, the data is collected in a ring buffer so old data will | |
6295 | be overwritten when the buffer is full. It allows limited replay and | |
6296 | reverse execution. | |
59ea5688 MM |
6297 | |
6298 | This recording method may not be available on all processors. | |
6299 | @end table | |
6300 | ||
6301 | The process record and replay target can only debug a process that is | |
6302 | already running. Therefore, you need first to start the process with | |
6303 | the @kbd{run} or @kbd{start} commands, and then start the recording | |
6304 | with the @kbd{record @var{method}} command. | |
6305 | ||
6306 | Both @code{record @var{method}} and @code{rec @var{method}} are | |
6307 | aliases of @code{target record-@var{method}}. | |
a2311334 EZ |
6308 | |
6309 | @cindex displaced stepping, and process record and replay | |
6310 | Displaced stepping (@pxref{Maintenance Commands,, displaced stepping}) | |
6311 | will be automatically disabled when process record and replay target | |
6312 | is started. That's because the process record and replay target | |
6313 | doesn't support displaced stepping. | |
6314 | ||
6315 | @cindex non-stop mode, and process record and replay | |
6316 | @cindex asynchronous execution, and process record and replay | |
6317 | If the inferior is in the non-stop mode (@pxref{Non-Stop Mode}) or in | |
59ea5688 MM |
6318 | the asynchronous execution mode (@pxref{Background Execution}), not |
6319 | all recording methods are available. The @code{full} recording method | |
6320 | does not support these two modes. | |
53cc454a HZ |
6321 | |
6322 | @kindex record stop | |
6323 | @kindex rec s | |
6324 | @item record stop | |
a2311334 EZ |
6325 | Stop the process record and replay target. When process record and |
6326 | replay target stops, the entire execution log will be deleted and the | |
6327 | inferior will either be terminated, or will remain in its final state. | |
53cc454a | 6328 | |
a2311334 EZ |
6329 | When you stop the process record and replay target in record mode (at |
6330 | the end of the execution log), the inferior will be stopped at the | |
6331 | next instruction that would have been recorded. In other words, if | |
6332 | you record for a while and then stop recording, the inferior process | |
6333 | will be left in the same state as if the recording never happened. | |
53cc454a | 6334 | |
a2311334 EZ |
6335 | On the other hand, if the process record and replay target is stopped |
6336 | while in replay mode (that is, not at the end of the execution log, | |
6337 | but at some earlier point), the inferior process will become ``live'' | |
6338 | at that earlier state, and it will then be possible to continue the | |
6339 | usual ``live'' debugging of the process from that state. | |
53cc454a | 6340 | |
a2311334 EZ |
6341 | When the inferior process exits, or @value{GDBN} detaches from it, |
6342 | process record and replay target will automatically stop itself. | |
53cc454a | 6343 | |
742ce053 MM |
6344 | @kindex record goto |
6345 | @item record goto | |
6346 | Go to a specific location in the execution log. There are several | |
6347 | ways to specify the location to go to: | |
6348 | ||
6349 | @table @code | |
6350 | @item record goto begin | |
6351 | @itemx record goto start | |
6352 | Go to the beginning of the execution log. | |
6353 | ||
6354 | @item record goto end | |
6355 | Go to the end of the execution log. | |
6356 | ||
6357 | @item record goto @var{n} | |
6358 | Go to instruction number @var{n} in the execution log. | |
6359 | @end table | |
6360 | ||
24e933df HZ |
6361 | @kindex record save |
6362 | @item record save @var{filename} | |
6363 | Save the execution log to a file @file{@var{filename}}. | |
6364 | Default filename is @file{gdb_record.@var{process_id}}, where | |
6365 | @var{process_id} is the process ID of the inferior. | |
6366 | ||
59ea5688 MM |
6367 | This command may not be available for all recording methods. |
6368 | ||
24e933df HZ |
6369 | @kindex record restore |
6370 | @item record restore @var{filename} | |
6371 | Restore the execution log from a file @file{@var{filename}}. | |
6372 | File must have been created with @code{record save}. | |
6373 | ||
59ea5688 MM |
6374 | @kindex set record full |
6375 | @item set record full insn-number-max @var{limit} | |
f81d1120 | 6376 | @itemx set record full insn-number-max unlimited |
59ea5688 MM |
6377 | Set the limit of instructions to be recorded for the @code{full} |
6378 | recording method. Default value is 200000. | |
53cc454a | 6379 | |
a2311334 EZ |
6380 | If @var{limit} is a positive number, then @value{GDBN} will start |
6381 | deleting instructions from the log once the number of the record | |
6382 | instructions becomes greater than @var{limit}. For every new recorded | |
6383 | instruction, @value{GDBN} will delete the earliest recorded | |
6384 | instruction to keep the number of recorded instructions at the limit. | |
6385 | (Since deleting recorded instructions loses information, @value{GDBN} | |
6386 | lets you control what happens when the limit is reached, by means of | |
6387 | the @code{stop-at-limit} option, described below.) | |
53cc454a | 6388 | |
f81d1120 PA |
6389 | If @var{limit} is @code{unlimited} or zero, @value{GDBN} will never |
6390 | delete recorded instructions from the execution log. The number of | |
6391 | recorded instructions is limited only by the available memory. | |
53cc454a | 6392 | |
59ea5688 MM |
6393 | @kindex show record full |
6394 | @item show record full insn-number-max | |
6395 | Show the limit of instructions to be recorded with the @code{full} | |
6396 | recording method. | |
53cc454a | 6397 | |
59ea5688 MM |
6398 | @item set record full stop-at-limit |
6399 | Control the behavior of the @code{full} recording method when the | |
6400 | number of recorded instructions reaches the limit. If ON (the | |
6401 | default), @value{GDBN} will stop when the limit is reached for the | |
6402 | first time and ask you whether you want to stop the inferior or | |
6403 | continue running it and recording the execution log. If you decide | |
6404 | to continue recording, each new recorded instruction will cause the | |
6405 | oldest one to be deleted. | |
53cc454a | 6406 | |
a2311334 EZ |
6407 | If this option is OFF, @value{GDBN} will automatically delete the |
6408 | oldest record to make room for each new one, without asking. | |
53cc454a | 6409 | |
59ea5688 | 6410 | @item show record full stop-at-limit |
a2311334 | 6411 | Show the current setting of @code{stop-at-limit}. |
53cc454a | 6412 | |
59ea5688 | 6413 | @item set record full memory-query |
bb08c432 | 6414 | Control the behavior when @value{GDBN} is unable to record memory |
59ea5688 MM |
6415 | changes caused by an instruction for the @code{full} recording method. |
6416 | If ON, @value{GDBN} will query whether to stop the inferior in that | |
6417 | case. | |
bb08c432 HZ |
6418 | |
6419 | If this option is OFF (the default), @value{GDBN} will automatically | |
6420 | ignore the effect of such instructions on memory. Later, when | |
6421 | @value{GDBN} replays this execution log, it will mark the log of this | |
6422 | instruction as not accessible, and it will not affect the replay | |
6423 | results. | |
6424 | ||
59ea5688 | 6425 | @item show record full memory-query |
bb08c432 HZ |
6426 | Show the current setting of @code{memory-query}. |
6427 | ||
67b5c0c1 MM |
6428 | @kindex set record btrace |
6429 | The @code{btrace} record target does not trace data. As a | |
6430 | convenience, when replaying, @value{GDBN} reads read-only memory off | |
6431 | the live program directly, assuming that the addresses of the | |
6432 | read-only areas don't change. This for example makes it possible to | |
6433 | disassemble code while replaying, but not to print variables. | |
6434 | In some cases, being able to inspect variables might be useful. | |
6435 | You can use the following command for that: | |
6436 | ||
6437 | @item set record btrace replay-memory-access | |
6438 | Control the behavior of the @code{btrace} recording method when | |
6439 | accessing memory during replay. If @code{read-only} (the default), | |
6440 | @value{GDBN} will only allow accesses to read-only memory. | |
6441 | If @code{read-write}, @value{GDBN} will allow accesses to read-only | |
6442 | and to read-write memory. Beware that the accessed memory corresponds | |
6443 | to the live target and not necessarily to the current replay | |
6444 | position. | |
6445 | ||
6446 | @kindex show record btrace | |
6447 | @item show record btrace replay-memory-access | |
6448 | Show the current setting of @code{replay-memory-access}. | |
6449 | ||
29153c24 MS |
6450 | @kindex info record |
6451 | @item info record | |
59ea5688 MM |
6452 | Show various statistics about the recording depending on the recording |
6453 | method: | |
6454 | ||
6455 | @table @code | |
6456 | @item full | |
6457 | For the @code{full} recording method, it shows the state of process | |
6458 | record and its in-memory execution log buffer, including: | |
29153c24 MS |
6459 | |
6460 | @itemize @bullet | |
6461 | @item | |
6462 | Whether in record mode or replay mode. | |
6463 | @item | |
6464 | Lowest recorded instruction number (counting from when the current execution log started recording instructions). | |
6465 | @item | |
6466 | Highest recorded instruction number. | |
6467 | @item | |
6468 | Current instruction about to be replayed (if in replay mode). | |
6469 | @item | |
6470 | Number of instructions contained in the execution log. | |
6471 | @item | |
6472 | Maximum number of instructions that may be contained in the execution log. | |
6473 | @end itemize | |
53cc454a | 6474 | |
59ea5688 MM |
6475 | @item btrace |
6476 | For the @code{btrace} recording method, it shows the number of | |
6477 | instructions that have been recorded and the number of blocks of | |
6478 | sequential control-flow that is formed by the recorded instructions. | |
6479 | @end table | |
6480 | ||
53cc454a HZ |
6481 | @kindex record delete |
6482 | @kindex rec del | |
6483 | @item record delete | |
a2311334 | 6484 | When record target runs in replay mode (``in the past''), delete the |
53cc454a | 6485 | subsequent execution log and begin to record a new execution log starting |
a2311334 | 6486 | from the current address. This means you will abandon the previously |
53cc454a | 6487 | recorded ``future'' and begin recording a new ``future''. |
59ea5688 MM |
6488 | |
6489 | @kindex record instruction-history | |
6490 | @kindex rec instruction-history | |
6491 | @item record instruction-history | |
6492 | Disassembles instructions from the recorded execution log. By | |
6493 | default, ten instructions are disassembled. This can be changed using | |
6494 | the @code{set record instruction-history-size} command. Instructions | |
6495 | are printed in execution order. There are several ways to specify | |
6496 | what part of the execution log to disassemble: | |
6497 | ||
6498 | @table @code | |
6499 | @item record instruction-history @var{insn} | |
6500 | Disassembles ten instructions starting from instruction number | |
6501 | @var{insn}. | |
6502 | ||
6503 | @item record instruction-history @var{insn}, +/-@var{n} | |
6504 | Disassembles @var{n} instructions around instruction number | |
6505 | @var{insn}. If @var{n} is preceded with @code{+}, disassembles | |
6506 | @var{n} instructions after instruction number @var{insn}. If | |
6507 | @var{n} is preceded with @code{-}, disassembles @var{n} | |
6508 | instructions before instruction number @var{insn}. | |
6509 | ||
6510 | @item record instruction-history | |
6511 | Disassembles ten more instructions after the last disassembly. | |
6512 | ||
6513 | @item record instruction-history - | |
6514 | Disassembles ten more instructions before the last disassembly. | |
6515 | ||
6516 | @item record instruction-history @var{begin} @var{end} | |
6517 | Disassembles instructions beginning with instruction number | |
6518 | @var{begin} until instruction number @var{end}. The instruction | |
0688d04e | 6519 | number @var{end} is included. |
59ea5688 MM |
6520 | @end table |
6521 | ||
6522 | This command may not be available for all recording methods. | |
6523 | ||
6524 | @kindex set record | |
f81d1120 PA |
6525 | @item set record instruction-history-size @var{size} |
6526 | @itemx set record instruction-history-size unlimited | |
59ea5688 MM |
6527 | Define how many instructions to disassemble in the @code{record |
6528 | instruction-history} command. The default value is 10. | |
f81d1120 | 6529 | A @var{size} of @code{unlimited} means unlimited instructions. |
59ea5688 MM |
6530 | |
6531 | @kindex show record | |
6532 | @item show record instruction-history-size | |
6533 | Show how many instructions to disassemble in the @code{record | |
6534 | instruction-history} command. | |
6535 | ||
6536 | @kindex record function-call-history | |
6537 | @kindex rec function-call-history | |
6538 | @item record function-call-history | |
6539 | Prints the execution history at function granularity. It prints one | |
6540 | line for each sequence of instructions that belong to the same | |
6541 | function giving the name of that function, the source lines | |
6542 | for this instruction sequence (if the @code{/l} modifier is | |
6543 | specified), and the instructions numbers that form the sequence (if | |
8710b709 MM |
6544 | the @code{/i} modifier is specified). The function names are indented |
6545 | to reflect the call stack depth if the @code{/c} modifier is | |
6546 | specified. The @code{/l}, @code{/i}, and @code{/c} modifiers can be | |
6547 | given together. | |
59ea5688 MM |
6548 | |
6549 | @smallexample | |
6550 | (@value{GDBP}) @b{list 1, 10} | |
6551 | 1 void foo (void) | |
6552 | 2 @{ | |
6553 | 3 @} | |
6554 | 4 | |
6555 | 5 void bar (void) | |
6556 | 6 @{ | |
6557 | 7 ... | |
6558 | 8 foo (); | |
6559 | 9 ... | |
6560 | 10 @} | |
8710b709 MM |
6561 | (@value{GDBP}) @b{record function-call-history /ilc} |
6562 | 1 bar inst 1,4 at foo.c:6,8 | |
6563 | 2 foo inst 5,10 at foo.c:2,3 | |
6564 | 3 bar inst 11,13 at foo.c:9,10 | |
59ea5688 MM |
6565 | @end smallexample |
6566 | ||
6567 | By default, ten lines are printed. This can be changed using the | |
6568 | @code{set record function-call-history-size} command. Functions are | |
6569 | printed in execution order. There are several ways to specify what | |
6570 | to print: | |
6571 | ||
6572 | @table @code | |
6573 | @item record function-call-history @var{func} | |
6574 | Prints ten functions starting from function number @var{func}. | |
6575 | ||
6576 | @item record function-call-history @var{func}, +/-@var{n} | |
6577 | Prints @var{n} functions around function number @var{func}. If | |
6578 | @var{n} is preceded with @code{+}, prints @var{n} functions after | |
6579 | function number @var{func}. If @var{n} is preceded with @code{-}, | |
6580 | prints @var{n} functions before function number @var{func}. | |
6581 | ||
6582 | @item record function-call-history | |
6583 | Prints ten more functions after the last ten-line print. | |
6584 | ||
6585 | @item record function-call-history - | |
6586 | Prints ten more functions before the last ten-line print. | |
6587 | ||
6588 | @item record function-call-history @var{begin} @var{end} | |
6589 | Prints functions beginning with function number @var{begin} until | |
0688d04e | 6590 | function number @var{end}. The function number @var{end} is included. |
59ea5688 MM |
6591 | @end table |
6592 | ||
6593 | This command may not be available for all recording methods. | |
6594 | ||
f81d1120 PA |
6595 | @item set record function-call-history-size @var{size} |
6596 | @itemx set record function-call-history-size unlimited | |
59ea5688 MM |
6597 | Define how many lines to print in the |
6598 | @code{record function-call-history} command. The default value is 10. | |
f81d1120 | 6599 | A size of @code{unlimited} means unlimited lines. |
59ea5688 MM |
6600 | |
6601 | @item show record function-call-history-size | |
6602 | Show how many lines to print in the | |
6603 | @code{record function-call-history} command. | |
53cc454a HZ |
6604 | @end table |
6605 | ||
6606 | ||
6d2ebf8b | 6607 | @node Stack |
c906108c SS |
6608 | @chapter Examining the Stack |
6609 | ||
6610 | When your program has stopped, the first thing you need to know is where it | |
6611 | stopped and how it got there. | |
6612 | ||
6613 | @cindex call stack | |
5d161b24 DB |
6614 | Each time your program performs a function call, information about the call |
6615 | is generated. | |
6616 | That information includes the location of the call in your program, | |
6617 | the arguments of the call, | |
c906108c | 6618 | and the local variables of the function being called. |
5d161b24 | 6619 | The information is saved in a block of data called a @dfn{stack frame}. |
c906108c SS |
6620 | The stack frames are allocated in a region of memory called the @dfn{call |
6621 | stack}. | |
6622 | ||
6623 | When your program stops, the @value{GDBN} commands for examining the | |
6624 | stack allow you to see all of this information. | |
6625 | ||
6626 | @cindex selected frame | |
6627 | One of the stack frames is @dfn{selected} by @value{GDBN} and many | |
6628 | @value{GDBN} commands refer implicitly to the selected frame. In | |
6629 | particular, whenever you ask @value{GDBN} for the value of a variable in | |
6630 | your program, the value is found in the selected frame. There are | |
6631 | special @value{GDBN} commands to select whichever frame you are | |
79a6e687 | 6632 | interested in. @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
6633 | |
6634 | When your program stops, @value{GDBN} automatically selects the | |
5d161b24 | 6635 | currently executing frame and describes it briefly, similar to the |
79a6e687 | 6636 | @code{frame} command (@pxref{Frame Info, ,Information about a Frame}). |
c906108c SS |
6637 | |
6638 | @menu | |
6639 | * Frames:: Stack frames | |
6640 | * Backtrace:: Backtraces | |
1e611234 | 6641 | * Frame Filter Management:: Managing frame filters |
c906108c SS |
6642 | * Selection:: Selecting a frame |
6643 | * Frame Info:: Information on a frame | |
c906108c SS |
6644 | |
6645 | @end menu | |
6646 | ||
6d2ebf8b | 6647 | @node Frames |
79a6e687 | 6648 | @section Stack Frames |
c906108c | 6649 | |
d4f3574e | 6650 | @cindex frame, definition |
c906108c SS |
6651 | @cindex stack frame |
6652 | The call stack is divided up into contiguous pieces called @dfn{stack | |
6653 | frames}, or @dfn{frames} for short; each frame is the data associated | |
6654 | with one call to one function. The frame contains the arguments given | |
6655 | to the function, the function's local variables, and the address at | |
6656 | which the function is executing. | |
6657 | ||
6658 | @cindex initial frame | |
6659 | @cindex outermost frame | |
6660 | @cindex innermost frame | |
6661 | When your program is started, the stack has only one frame, that of the | |
6662 | function @code{main}. This is called the @dfn{initial} frame or the | |
6663 | @dfn{outermost} frame. Each time a function is called, a new frame is | |
6664 | made. Each time a function returns, the frame for that function invocation | |
6665 | is eliminated. If a function is recursive, there can be many frames for | |
6666 | the same function. The frame for the function in which execution is | |
6667 | actually occurring is called the @dfn{innermost} frame. This is the most | |
6668 | recently created of all the stack frames that still exist. | |
6669 | ||
6670 | @cindex frame pointer | |
6671 | Inside your program, stack frames are identified by their addresses. A | |
6672 | stack frame consists of many bytes, each of which has its own address; each | |
6673 | kind of computer has a convention for choosing one byte whose | |
6674 | address serves as the address of the frame. Usually this address is kept | |
e09f16f9 EZ |
6675 | in a register called the @dfn{frame pointer register} |
6676 | (@pxref{Registers, $fp}) while execution is going on in that frame. | |
c906108c SS |
6677 | |
6678 | @cindex frame number | |
6679 | @value{GDBN} assigns numbers to all existing stack frames, starting with | |
6680 | zero for the innermost frame, one for the frame that called it, | |
6681 | and so on upward. These numbers do not really exist in your program; | |
6682 | they are assigned by @value{GDBN} to give you a way of designating stack | |
6683 | frames in @value{GDBN} commands. | |
6684 | ||
6d2ebf8b SS |
6685 | @c The -fomit-frame-pointer below perennially causes hbox overflow |
6686 | @c underflow problems. | |
c906108c SS |
6687 | @cindex frameless execution |
6688 | Some compilers provide a way to compile functions so that they operate | |
e22ea452 | 6689 | without stack frames. (For example, the @value{NGCC} option |
474c8240 | 6690 | @smallexample |
6d2ebf8b | 6691 | @samp{-fomit-frame-pointer} |
474c8240 | 6692 | @end smallexample |
6d2ebf8b | 6693 | generates functions without a frame.) |
c906108c SS |
6694 | This is occasionally done with heavily used library functions to save |
6695 | the frame setup time. @value{GDBN} has limited facilities for dealing | |
6696 | with these function invocations. If the innermost function invocation | |
6697 | has no stack frame, @value{GDBN} nevertheless regards it as though | |
6698 | it had a separate frame, which is numbered zero as usual, allowing | |
6699 | correct tracing of the function call chain. However, @value{GDBN} has | |
6700 | no provision for frameless functions elsewhere in the stack. | |
6701 | ||
6702 | @table @code | |
d4f3574e | 6703 | @kindex frame@r{, command} |
41afff9a | 6704 | @cindex current stack frame |
697aa1b7 | 6705 | @item frame @r{[}@var{framespec}@r{]} |
5d161b24 | 6706 | The @code{frame} command allows you to move from one stack frame to another, |
697aa1b7 | 6707 | and to print the stack frame you select. The @var{framespec} may be either the |
5d161b24 DB |
6708 | address of the frame or the stack frame number. Without an argument, |
6709 | @code{frame} prints the current stack frame. | |
c906108c SS |
6710 | |
6711 | @kindex select-frame | |
41afff9a | 6712 | @cindex selecting frame silently |
c906108c SS |
6713 | @item select-frame |
6714 | The @code{select-frame} command allows you to move from one stack frame | |
6715 | to another without printing the frame. This is the silent version of | |
6716 | @code{frame}. | |
6717 | @end table | |
6718 | ||
6d2ebf8b | 6719 | @node Backtrace |
c906108c SS |
6720 | @section Backtraces |
6721 | ||
09d4efe1 EZ |
6722 | @cindex traceback |
6723 | @cindex call stack traces | |
c906108c SS |
6724 | A backtrace is a summary of how your program got where it is. It shows one |
6725 | line per frame, for many frames, starting with the currently executing | |
6726 | frame (frame zero), followed by its caller (frame one), and on up the | |
6727 | stack. | |
6728 | ||
1e611234 | 6729 | @anchor{backtrace-command} |
c906108c SS |
6730 | @table @code |
6731 | @kindex backtrace | |
41afff9a | 6732 | @kindex bt @r{(@code{backtrace})} |
c906108c SS |
6733 | @item backtrace |
6734 | @itemx bt | |
6735 | Print a backtrace of the entire stack: one line per frame for all | |
6736 | frames in the stack. | |
6737 | ||
6738 | You can stop the backtrace at any time by typing the system interrupt | |
c8aa23ab | 6739 | character, normally @kbd{Ctrl-c}. |
c906108c SS |
6740 | |
6741 | @item backtrace @var{n} | |
6742 | @itemx bt @var{n} | |
6743 | Similar, but print only the innermost @var{n} frames. | |
6744 | ||
6745 | @item backtrace -@var{n} | |
6746 | @itemx bt -@var{n} | |
6747 | Similar, but print only the outermost @var{n} frames. | |
0f061b69 NR |
6748 | |
6749 | @item backtrace full | |
0f061b69 | 6750 | @itemx bt full |
dd74f6ae NR |
6751 | @itemx bt full @var{n} |
6752 | @itemx bt full -@var{n} | |
697aa1b7 EZ |
6753 | Print the values of the local variables also. As described above, |
6754 | @var{n} specifies the number of frames to print. | |
1e611234 PM |
6755 | |
6756 | @item backtrace no-filters | |
6757 | @itemx bt no-filters | |
6758 | @itemx bt no-filters @var{n} | |
6759 | @itemx bt no-filters -@var{n} | |
6760 | @itemx bt no-filters full | |
6761 | @itemx bt no-filters full @var{n} | |
6762 | @itemx bt no-filters full -@var{n} | |
6763 | Do not run Python frame filters on this backtrace. @xref{Frame | |
6764 | Filter API}, for more information. Additionally use @ref{disable | |
6765 | frame-filter all} to turn off all frame filters. This is only | |
6766 | relevant when @value{GDBN} has been configured with @code{Python} | |
6767 | support. | |
c906108c SS |
6768 | @end table |
6769 | ||
6770 | @kindex where | |
6771 | @kindex info stack | |
c906108c SS |
6772 | The names @code{where} and @code{info stack} (abbreviated @code{info s}) |
6773 | are additional aliases for @code{backtrace}. | |
6774 | ||
839c27b7 EZ |
6775 | @cindex multiple threads, backtrace |
6776 | In a multi-threaded program, @value{GDBN} by default shows the | |
6777 | backtrace only for the current thread. To display the backtrace for | |
6778 | several or all of the threads, use the command @code{thread apply} | |
6779 | (@pxref{Threads, thread apply}). For example, if you type @kbd{thread | |
6780 | apply all backtrace}, @value{GDBN} will display the backtrace for all | |
6781 | the threads; this is handy when you debug a core dump of a | |
6782 | multi-threaded program. | |
6783 | ||
c906108c SS |
6784 | Each line in the backtrace shows the frame number and the function name. |
6785 | The program counter value is also shown---unless you use @code{set | |
6786 | print address off}. The backtrace also shows the source file name and | |
6787 | line number, as well as the arguments to the function. The program | |
6788 | counter value is omitted if it is at the beginning of the code for that | |
6789 | line number. | |
6790 | ||
6791 | Here is an example of a backtrace. It was made with the command | |
6792 | @samp{bt 3}, so it shows the innermost three frames. | |
6793 | ||
6794 | @smallexample | |
6795 | @group | |
5d161b24 | 6796 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) |
c906108c | 6797 | at builtin.c:993 |
4f5376b2 | 6798 | #1 0x6e38 in expand_macro (sym=0x2b600, data=...) at macro.c:242 |
c906108c SS |
6799 | #2 0x6840 in expand_token (obs=0x0, t=177664, td=0xf7fffb08) |
6800 | at macro.c:71 | |
6801 | (More stack frames follow...) | |
6802 | @end group | |
6803 | @end smallexample | |
6804 | ||
6805 | @noindent | |
6806 | The display for frame zero does not begin with a program counter | |
6807 | value, indicating that your program has stopped at the beginning of the | |
6808 | code for line @code{993} of @code{builtin.c}. | |
6809 | ||
4f5376b2 JB |
6810 | @noindent |
6811 | The value of parameter @code{data} in frame 1 has been replaced by | |
6812 | @code{@dots{}}. By default, @value{GDBN} prints the value of a parameter | |
6813 | only if it is a scalar (integer, pointer, enumeration, etc). See command | |
6814 | @kbd{set print frame-arguments} in @ref{Print Settings} for more details | |
6815 | on how to configure the way function parameter values are printed. | |
6816 | ||
585fdaa1 | 6817 | @cindex optimized out, in backtrace |
18999be5 EZ |
6818 | @cindex function call arguments, optimized out |
6819 | If your program was compiled with optimizations, some compilers will | |
6820 | optimize away arguments passed to functions if those arguments are | |
6821 | never used after the call. Such optimizations generate code that | |
6822 | passes arguments through registers, but doesn't store those arguments | |
6823 | in the stack frame. @value{GDBN} has no way of displaying such | |
6824 | arguments in stack frames other than the innermost one. Here's what | |
6825 | such a backtrace might look like: | |
6826 | ||
6827 | @smallexample | |
6828 | @group | |
6829 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) | |
6830 | at builtin.c:993 | |
585fdaa1 PA |
6831 | #1 0x6e38 in expand_macro (sym=<optimized out>) at macro.c:242 |
6832 | #2 0x6840 in expand_token (obs=0x0, t=<optimized out>, td=0xf7fffb08) | |
18999be5 EZ |
6833 | at macro.c:71 |
6834 | (More stack frames follow...) | |
6835 | @end group | |
6836 | @end smallexample | |
6837 | ||
6838 | @noindent | |
6839 | The values of arguments that were not saved in their stack frames are | |
585fdaa1 | 6840 | shown as @samp{<optimized out>}. |
18999be5 EZ |
6841 | |
6842 | If you need to display the values of such optimized-out arguments, | |
6843 | either deduce that from other variables whose values depend on the one | |
6844 | you are interested in, or recompile without optimizations. | |
6845 | ||
a8f24a35 EZ |
6846 | @cindex backtrace beyond @code{main} function |
6847 | @cindex program entry point | |
6848 | @cindex startup code, and backtrace | |
25d29d70 AC |
6849 | Most programs have a standard user entry point---a place where system |
6850 | libraries and startup code transition into user code. For C this is | |
d416eeec EZ |
6851 | @code{main}@footnote{ |
6852 | Note that embedded programs (the so-called ``free-standing'' | |
6853 | environment) are not required to have a @code{main} function as the | |
6854 | entry point. They could even have multiple entry points.}. | |
6855 | When @value{GDBN} finds the entry function in a backtrace | |
25d29d70 AC |
6856 | it will terminate the backtrace, to avoid tracing into highly |
6857 | system-specific (and generally uninteresting) code. | |
6858 | ||
6859 | If you need to examine the startup code, or limit the number of levels | |
6860 | in a backtrace, you can change this behavior: | |
95f90d25 DJ |
6861 | |
6862 | @table @code | |
25d29d70 AC |
6863 | @item set backtrace past-main |
6864 | @itemx set backtrace past-main on | |
4644b6e3 | 6865 | @kindex set backtrace |
25d29d70 AC |
6866 | Backtraces will continue past the user entry point. |
6867 | ||
6868 | @item set backtrace past-main off | |
95f90d25 DJ |
6869 | Backtraces will stop when they encounter the user entry point. This is the |
6870 | default. | |
6871 | ||
25d29d70 | 6872 | @item show backtrace past-main |
4644b6e3 | 6873 | @kindex show backtrace |
25d29d70 AC |
6874 | Display the current user entry point backtrace policy. |
6875 | ||
2315ffec RC |
6876 | @item set backtrace past-entry |
6877 | @itemx set backtrace past-entry on | |
a8f24a35 | 6878 | Backtraces will continue past the internal entry point of an application. |
2315ffec RC |
6879 | This entry point is encoded by the linker when the application is built, |
6880 | and is likely before the user entry point @code{main} (or equivalent) is called. | |
6881 | ||
6882 | @item set backtrace past-entry off | |
d3e8051b | 6883 | Backtraces will stop when they encounter the internal entry point of an |
2315ffec RC |
6884 | application. This is the default. |
6885 | ||
6886 | @item show backtrace past-entry | |
6887 | Display the current internal entry point backtrace policy. | |
6888 | ||
25d29d70 AC |
6889 | @item set backtrace limit @var{n} |
6890 | @itemx set backtrace limit 0 | |
f81d1120 | 6891 | @itemx set backtrace limit unlimited |
25d29d70 | 6892 | @cindex backtrace limit |
f81d1120 PA |
6893 | Limit the backtrace to @var{n} levels. A value of @code{unlimited} |
6894 | or zero means unlimited levels. | |
95f90d25 | 6895 | |
25d29d70 AC |
6896 | @item show backtrace limit |
6897 | Display the current limit on backtrace levels. | |
95f90d25 DJ |
6898 | @end table |
6899 | ||
1b56eb55 JK |
6900 | You can control how file names are displayed. |
6901 | ||
6902 | @table @code | |
6903 | @item set filename-display | |
6904 | @itemx set filename-display relative | |
6905 | @cindex filename-display | |
6906 | Display file names relative to the compilation directory. This is the default. | |
6907 | ||
6908 | @item set filename-display basename | |
6909 | Display only basename of a filename. | |
6910 | ||
6911 | @item set filename-display absolute | |
6912 | Display an absolute filename. | |
6913 | ||
6914 | @item show filename-display | |
6915 | Show the current way to display filenames. | |
6916 | @end table | |
6917 | ||
1e611234 PM |
6918 | @node Frame Filter Management |
6919 | @section Management of Frame Filters. | |
6920 | @cindex managing frame filters | |
6921 | ||
6922 | Frame filters are Python based utilities to manage and decorate the | |
6923 | output of frames. @xref{Frame Filter API}, for further information. | |
6924 | ||
6925 | Managing frame filters is performed by several commands available | |
6926 | within @value{GDBN}, detailed here. | |
6927 | ||
6928 | @table @code | |
6929 | @kindex info frame-filter | |
6930 | @item info frame-filter | |
6931 | Print a list of installed frame filters from all dictionaries, showing | |
6932 | their name, priority and enabled status. | |
6933 | ||
6934 | @kindex disable frame-filter | |
6935 | @anchor{disable frame-filter all} | |
6936 | @item disable frame-filter @var{filter-dictionary} @var{filter-name} | |
6937 | Disable a frame filter in the dictionary matching | |
697aa1b7 | 6938 | @var{filter-dictionary} and @var{filter-name}. The |
1e611234 | 6939 | @var{filter-dictionary} may be @code{all}, @code{global}, |
697aa1b7 | 6940 | @code{progspace}, or the name of the object file where the frame filter |
1e611234 | 6941 | dictionary resides. When @code{all} is specified, all frame filters |
697aa1b7 | 6942 | across all dictionaries are disabled. The @var{filter-name} is the name |
1e611234 PM |
6943 | of the frame filter and is used when @code{all} is not the option for |
6944 | @var{filter-dictionary}. A disabled frame-filter is not deleted, it | |
6945 | may be enabled again later. | |
6946 | ||
6947 | @kindex enable frame-filter | |
6948 | @item enable frame-filter @var{filter-dictionary} @var{filter-name} | |
6949 | Enable a frame filter in the dictionary matching | |
697aa1b7 | 6950 | @var{filter-dictionary} and @var{filter-name}. The |
1e611234 PM |
6951 | @var{filter-dictionary} may be @code{all}, @code{global}, |
6952 | @code{progspace} or the name of the object file where the frame filter | |
6953 | dictionary resides. When @code{all} is specified, all frame filters across | |
697aa1b7 | 6954 | all dictionaries are enabled. The @var{filter-name} is the name of the frame |
1e611234 PM |
6955 | filter and is used when @code{all} is not the option for |
6956 | @var{filter-dictionary}. | |
6957 | ||
6958 | Example: | |
6959 | ||
6960 | @smallexample | |
6961 | (gdb) info frame-filter | |
6962 | ||
6963 | global frame-filters: | |
6964 | Priority Enabled Name | |
6965 | 1000 No PrimaryFunctionFilter | |
6966 | 100 Yes Reverse | |
6967 | ||
6968 | progspace /build/test frame-filters: | |
6969 | Priority Enabled Name | |
6970 | 100 Yes ProgspaceFilter | |
6971 | ||
6972 | objfile /build/test frame-filters: | |
6973 | Priority Enabled Name | |
6974 | 999 Yes BuildProgra Filter | |
6975 | ||
6976 | (gdb) disable frame-filter /build/test BuildProgramFilter | |
6977 | (gdb) info frame-filter | |
6978 | ||
6979 | global frame-filters: | |
6980 | Priority Enabled Name | |
6981 | 1000 No PrimaryFunctionFilter | |
6982 | 100 Yes Reverse | |
6983 | ||
6984 | progspace /build/test frame-filters: | |
6985 | Priority Enabled Name | |
6986 | 100 Yes ProgspaceFilter | |
6987 | ||
6988 | objfile /build/test frame-filters: | |
6989 | Priority Enabled Name | |
6990 | 999 No BuildProgramFilter | |
6991 | ||
6992 | (gdb) enable frame-filter global PrimaryFunctionFilter | |
6993 | (gdb) info frame-filter | |
6994 | ||
6995 | global frame-filters: | |
6996 | Priority Enabled Name | |
6997 | 1000 Yes PrimaryFunctionFilter | |
6998 | 100 Yes Reverse | |
6999 | ||
7000 | progspace /build/test frame-filters: | |
7001 | Priority Enabled Name | |
7002 | 100 Yes ProgspaceFilter | |
7003 | ||
7004 | objfile /build/test frame-filters: | |
7005 | Priority Enabled Name | |
7006 | 999 No BuildProgramFilter | |
7007 | @end smallexample | |
7008 | ||
7009 | @kindex set frame-filter priority | |
7010 | @item set frame-filter priority @var{filter-dictionary} @var{filter-name} @var{priority} | |
7011 | Set the @var{priority} of a frame filter in the dictionary matching | |
7012 | @var{filter-dictionary}, and the frame filter name matching | |
697aa1b7 | 7013 | @var{filter-name}. The @var{filter-dictionary} may be @code{global}, |
1e611234 | 7014 | @code{progspace} or the name of the object file where the frame filter |
697aa1b7 | 7015 | dictionary resides. The @var{priority} is an integer. |
1e611234 PM |
7016 | |
7017 | @kindex show frame-filter priority | |
7018 | @item show frame-filter priority @var{filter-dictionary} @var{filter-name} | |
7019 | Show the @var{priority} of a frame filter in the dictionary matching | |
7020 | @var{filter-dictionary}, and the frame filter name matching | |
697aa1b7 | 7021 | @var{filter-name}. The @var{filter-dictionary} may be @code{global}, |
1e611234 PM |
7022 | @code{progspace} or the name of the object file where the frame filter |
7023 | dictionary resides. | |
7024 | ||
7025 | Example: | |
7026 | ||
7027 | @smallexample | |
7028 | (gdb) info frame-filter | |
7029 | ||
7030 | global frame-filters: | |
7031 | Priority Enabled Name | |
7032 | 1000 Yes PrimaryFunctionFilter | |
7033 | 100 Yes Reverse | |
7034 | ||
7035 | progspace /build/test frame-filters: | |
7036 | Priority Enabled Name | |
7037 | 100 Yes ProgspaceFilter | |
7038 | ||
7039 | objfile /build/test frame-filters: | |
7040 | Priority Enabled Name | |
7041 | 999 No BuildProgramFilter | |
7042 | ||
7043 | (gdb) set frame-filter priority global Reverse 50 | |
7044 | (gdb) info frame-filter | |
7045 | ||
7046 | global frame-filters: | |
7047 | Priority Enabled Name | |
7048 | 1000 Yes PrimaryFunctionFilter | |
7049 | 50 Yes Reverse | |
7050 | ||
7051 | progspace /build/test frame-filters: | |
7052 | Priority Enabled Name | |
7053 | 100 Yes ProgspaceFilter | |
7054 | ||
7055 | objfile /build/test frame-filters: | |
7056 | Priority Enabled Name | |
7057 | 999 No BuildProgramFilter | |
7058 | @end smallexample | |
7059 | @end table | |
7060 | ||
6d2ebf8b | 7061 | @node Selection |
79a6e687 | 7062 | @section Selecting a Frame |
c906108c SS |
7063 | |
7064 | Most commands for examining the stack and other data in your program work on | |
7065 | whichever stack frame is selected at the moment. Here are the commands for | |
7066 | selecting a stack frame; all of them finish by printing a brief description | |
7067 | of the stack frame just selected. | |
7068 | ||
7069 | @table @code | |
d4f3574e | 7070 | @kindex frame@r{, selecting} |
41afff9a | 7071 | @kindex f @r{(@code{frame})} |
c906108c SS |
7072 | @item frame @var{n} |
7073 | @itemx f @var{n} | |
7074 | Select frame number @var{n}. Recall that frame zero is the innermost | |
7075 | (currently executing) frame, frame one is the frame that called the | |
7076 | innermost one, and so on. The highest-numbered frame is the one for | |
7077 | @code{main}. | |
7078 | ||
7079 | @item frame @var{addr} | |
7080 | @itemx f @var{addr} | |
7081 | Select the frame at address @var{addr}. This is useful mainly if the | |
7082 | chaining of stack frames has been damaged by a bug, making it | |
7083 | impossible for @value{GDBN} to assign numbers properly to all frames. In | |
7084 | addition, this can be useful when your program has multiple stacks and | |
7085 | switches between them. | |
7086 | ||
c906108c SS |
7087 | On the SPARC architecture, @code{frame} needs two addresses to |
7088 | select an arbitrary frame: a frame pointer and a stack pointer. | |
7089 | ||
eb17f351 | 7090 | On the @acronym{MIPS} and Alpha architecture, it needs two addresses: a stack |
c906108c SS |
7091 | pointer and a program counter. |
7092 | ||
7093 | On the 29k architecture, it needs three addresses: a register stack | |
7094 | pointer, a program counter, and a memory stack pointer. | |
c906108c SS |
7095 | |
7096 | @kindex up | |
7097 | @item up @var{n} | |
697aa1b7 EZ |
7098 | Move @var{n} frames up the stack; @var{n} defaults to 1. For positive |
7099 | numbers @var{n}, this advances toward the outermost frame, to higher | |
7100 | frame numbers, to frames that have existed longer. | |
c906108c SS |
7101 | |
7102 | @kindex down | |
41afff9a | 7103 | @kindex do @r{(@code{down})} |
c906108c | 7104 | @item down @var{n} |
697aa1b7 EZ |
7105 | Move @var{n} frames down the stack; @var{n} defaults to 1. For |
7106 | positive numbers @var{n}, this advances toward the innermost frame, to | |
7107 | lower frame numbers, to frames that were created more recently. | |
7108 | You may abbreviate @code{down} as @code{do}. | |
c906108c SS |
7109 | @end table |
7110 | ||
7111 | All of these commands end by printing two lines of output describing the | |
7112 | frame. The first line shows the frame number, the function name, the | |
7113 | arguments, and the source file and line number of execution in that | |
5d161b24 | 7114 | frame. The second line shows the text of that source line. |
c906108c SS |
7115 | |
7116 | @need 1000 | |
7117 | For example: | |
7118 | ||
7119 | @smallexample | |
7120 | @group | |
7121 | (@value{GDBP}) up | |
7122 | #1 0x22f0 in main (argc=1, argv=0xf7fffbf4, env=0xf7fffbfc) | |
7123 | at env.c:10 | |
7124 | 10 read_input_file (argv[i]); | |
7125 | @end group | |
7126 | @end smallexample | |
7127 | ||
7128 | After such a printout, the @code{list} command with no arguments | |
7129 | prints ten lines centered on the point of execution in the frame. | |
87885426 FN |
7130 | You can also edit the program at the point of execution with your favorite |
7131 | editing program by typing @code{edit}. | |
79a6e687 | 7132 | @xref{List, ,Printing Source Lines}, |
87885426 | 7133 | for details. |
c906108c SS |
7134 | |
7135 | @table @code | |
7136 | @kindex down-silently | |
7137 | @kindex up-silently | |
7138 | @item up-silently @var{n} | |
7139 | @itemx down-silently @var{n} | |
7140 | These two commands are variants of @code{up} and @code{down}, | |
7141 | respectively; they differ in that they do their work silently, without | |
7142 | causing display of the new frame. They are intended primarily for use | |
7143 | in @value{GDBN} command scripts, where the output might be unnecessary and | |
7144 | distracting. | |
7145 | @end table | |
7146 | ||
6d2ebf8b | 7147 | @node Frame Info |
79a6e687 | 7148 | @section Information About a Frame |
c906108c SS |
7149 | |
7150 | There are several other commands to print information about the selected | |
7151 | stack frame. | |
7152 | ||
7153 | @table @code | |
7154 | @item frame | |
7155 | @itemx f | |
7156 | When used without any argument, this command does not change which | |
7157 | frame is selected, but prints a brief description of the currently | |
7158 | selected stack frame. It can be abbreviated @code{f}. With an | |
7159 | argument, this command is used to select a stack frame. | |
79a6e687 | 7160 | @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
7161 | |
7162 | @kindex info frame | |
41afff9a | 7163 | @kindex info f @r{(@code{info frame})} |
c906108c SS |
7164 | @item info frame |
7165 | @itemx info f | |
7166 | This command prints a verbose description of the selected stack frame, | |
7167 | including: | |
7168 | ||
7169 | @itemize @bullet | |
5d161b24 DB |
7170 | @item |
7171 | the address of the frame | |
c906108c SS |
7172 | @item |
7173 | the address of the next frame down (called by this frame) | |
7174 | @item | |
7175 | the address of the next frame up (caller of this frame) | |
7176 | @item | |
7177 | the language in which the source code corresponding to this frame is written | |
7178 | @item | |
7179 | the address of the frame's arguments | |
7180 | @item | |
d4f3574e SS |
7181 | the address of the frame's local variables |
7182 | @item | |
c906108c SS |
7183 | the program counter saved in it (the address of execution in the caller frame) |
7184 | @item | |
7185 | which registers were saved in the frame | |
7186 | @end itemize | |
7187 | ||
7188 | @noindent The verbose description is useful when | |
7189 | something has gone wrong that has made the stack format fail to fit | |
7190 | the usual conventions. | |
7191 | ||
7192 | @item info frame @var{addr} | |
7193 | @itemx info f @var{addr} | |
7194 | Print a verbose description of the frame at address @var{addr}, without | |
7195 | selecting that frame. The selected frame remains unchanged by this | |
7196 | command. This requires the same kind of address (more than one for some | |
7197 | architectures) that you specify in the @code{frame} command. | |
79a6e687 | 7198 | @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
7199 | |
7200 | @kindex info args | |
7201 | @item info args | |
7202 | Print the arguments of the selected frame, each on a separate line. | |
7203 | ||
7204 | @item info locals | |
7205 | @kindex info locals | |
7206 | Print the local variables of the selected frame, each on a separate | |
7207 | line. These are all variables (declared either static or automatic) | |
7208 | accessible at the point of execution of the selected frame. | |
7209 | ||
c906108c SS |
7210 | @end table |
7211 | ||
c906108c | 7212 | |
6d2ebf8b | 7213 | @node Source |
c906108c SS |
7214 | @chapter Examining Source Files |
7215 | ||
7216 | @value{GDBN} can print parts of your program's source, since the debugging | |
7217 | information recorded in the program tells @value{GDBN} what source files were | |
7218 | used to build it. When your program stops, @value{GDBN} spontaneously prints | |
7219 | the line where it stopped. Likewise, when you select a stack frame | |
79a6e687 | 7220 | (@pxref{Selection, ,Selecting a Frame}), @value{GDBN} prints the line where |
c906108c SS |
7221 | execution in that frame has stopped. You can print other portions of |
7222 | source files by explicit command. | |
7223 | ||
7a292a7a | 7224 | If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may |
d4f3574e | 7225 | prefer to use Emacs facilities to view source; see @ref{Emacs, ,Using |
7a292a7a | 7226 | @value{GDBN} under @sc{gnu} Emacs}. |
c906108c SS |
7227 | |
7228 | @menu | |
7229 | * List:: Printing source lines | |
2a25a5ba | 7230 | * Specify Location:: How to specify code locations |
87885426 | 7231 | * Edit:: Editing source files |
c906108c | 7232 | * Search:: Searching source files |
c906108c SS |
7233 | * Source Path:: Specifying source directories |
7234 | * Machine Code:: Source and machine code | |
7235 | @end menu | |
7236 | ||
6d2ebf8b | 7237 | @node List |
79a6e687 | 7238 | @section Printing Source Lines |
c906108c SS |
7239 | |
7240 | @kindex list | |
41afff9a | 7241 | @kindex l @r{(@code{list})} |
c906108c | 7242 | To print lines from a source file, use the @code{list} command |
5d161b24 | 7243 | (abbreviated @code{l}). By default, ten lines are printed. |
2a25a5ba EZ |
7244 | There are several ways to specify what part of the file you want to |
7245 | print; see @ref{Specify Location}, for the full list. | |
c906108c SS |
7246 | |
7247 | Here are the forms of the @code{list} command most commonly used: | |
7248 | ||
7249 | @table @code | |
7250 | @item list @var{linenum} | |
7251 | Print lines centered around line number @var{linenum} in the | |
7252 | current source file. | |
7253 | ||
7254 | @item list @var{function} | |
7255 | Print lines centered around the beginning of function | |
7256 | @var{function}. | |
7257 | ||
7258 | @item list | |
7259 | Print more lines. If the last lines printed were printed with a | |
7260 | @code{list} command, this prints lines following the last lines | |
7261 | printed; however, if the last line printed was a solitary line printed | |
7262 | as part of displaying a stack frame (@pxref{Stack, ,Examining the | |
7263 | Stack}), this prints lines centered around that line. | |
7264 | ||
7265 | @item list - | |
7266 | Print lines just before the lines last printed. | |
7267 | @end table | |
7268 | ||
9c16f35a | 7269 | @cindex @code{list}, how many lines to display |
c906108c SS |
7270 | By default, @value{GDBN} prints ten source lines with any of these forms of |
7271 | the @code{list} command. You can change this using @code{set listsize}: | |
7272 | ||
7273 | @table @code | |
7274 | @kindex set listsize | |
7275 | @item set listsize @var{count} | |
f81d1120 | 7276 | @itemx set listsize unlimited |
c906108c SS |
7277 | Make the @code{list} command display @var{count} source lines (unless |
7278 | the @code{list} argument explicitly specifies some other number). | |
f81d1120 | 7279 | Setting @var{count} to @code{unlimited} or 0 means there's no limit. |
c906108c SS |
7280 | |
7281 | @kindex show listsize | |
7282 | @item show listsize | |
7283 | Display the number of lines that @code{list} prints. | |
7284 | @end table | |
7285 | ||
7286 | Repeating a @code{list} command with @key{RET} discards the argument, | |
7287 | so it is equivalent to typing just @code{list}. This is more useful | |
7288 | than listing the same lines again. An exception is made for an | |
7289 | argument of @samp{-}; that argument is preserved in repetition so that | |
7290 | each repetition moves up in the source file. | |
7291 | ||
c906108c SS |
7292 | In general, the @code{list} command expects you to supply zero, one or two |
7293 | @dfn{linespecs}. Linespecs specify source lines; there are several ways | |
2a25a5ba EZ |
7294 | of writing them (@pxref{Specify Location}), but the effect is always |
7295 | to specify some source line. | |
7296 | ||
c906108c SS |
7297 | Here is a complete description of the possible arguments for @code{list}: |
7298 | ||
7299 | @table @code | |
7300 | @item list @var{linespec} | |
7301 | Print lines centered around the line specified by @var{linespec}. | |
7302 | ||
7303 | @item list @var{first},@var{last} | |
7304 | Print lines from @var{first} to @var{last}. Both arguments are | |
2a25a5ba EZ |
7305 | linespecs. When a @code{list} command has two linespecs, and the |
7306 | source file of the second linespec is omitted, this refers to | |
7307 | the same source file as the first linespec. | |
c906108c SS |
7308 | |
7309 | @item list ,@var{last} | |
7310 | Print lines ending with @var{last}. | |
7311 | ||
7312 | @item list @var{first}, | |
7313 | Print lines starting with @var{first}. | |
7314 | ||
7315 | @item list + | |
7316 | Print lines just after the lines last printed. | |
7317 | ||
7318 | @item list - | |
7319 | Print lines just before the lines last printed. | |
7320 | ||
7321 | @item list | |
7322 | As described in the preceding table. | |
7323 | @end table | |
7324 | ||
2a25a5ba EZ |
7325 | @node Specify Location |
7326 | @section Specifying a Location | |
7327 | @cindex specifying location | |
7328 | @cindex linespec | |
c906108c | 7329 | |
2a25a5ba EZ |
7330 | Several @value{GDBN} commands accept arguments that specify a location |
7331 | of your program's code. Since @value{GDBN} is a source-level | |
7332 | debugger, a location usually specifies some line in the source code; | |
7333 | for that reason, locations are also known as @dfn{linespecs}. | |
c906108c | 7334 | |
2a25a5ba EZ |
7335 | Here are all the different ways of specifying a code location that |
7336 | @value{GDBN} understands: | |
c906108c | 7337 | |
2a25a5ba EZ |
7338 | @table @code |
7339 | @item @var{linenum} | |
7340 | Specifies the line number @var{linenum} of the current source file. | |
c906108c | 7341 | |
2a25a5ba EZ |
7342 | @item -@var{offset} |
7343 | @itemx +@var{offset} | |
7344 | Specifies the line @var{offset} lines before or after the @dfn{current | |
7345 | line}. For the @code{list} command, the current line is the last one | |
7346 | printed; for the breakpoint commands, this is the line at which | |
7347 | execution stopped in the currently selected @dfn{stack frame} | |
7348 | (@pxref{Frames, ,Frames}, for a description of stack frames.) When | |
7349 | used as the second of the two linespecs in a @code{list} command, | |
7350 | this specifies the line @var{offset} lines up or down from the first | |
7351 | linespec. | |
7352 | ||
7353 | @item @var{filename}:@var{linenum} | |
7354 | Specifies the line @var{linenum} in the source file @var{filename}. | |
4aac40c8 TT |
7355 | If @var{filename} is a relative file name, then it will match any |
7356 | source file name with the same trailing components. For example, if | |
7357 | @var{filename} is @samp{gcc/expr.c}, then it will match source file | |
7358 | name of @file{/build/trunk/gcc/expr.c}, but not | |
7359 | @file{/build/trunk/libcpp/expr.c} or @file{/build/trunk/gcc/x-expr.c}. | |
c906108c SS |
7360 | |
7361 | @item @var{function} | |
7362 | Specifies the line that begins the body of the function @var{function}. | |
2a25a5ba | 7363 | For example, in C, this is the line with the open brace. |
c906108c | 7364 | |
9ef07c8c TT |
7365 | @item @var{function}:@var{label} |
7366 | Specifies the line where @var{label} appears in @var{function}. | |
7367 | ||
c906108c | 7368 | @item @var{filename}:@var{function} |
2a25a5ba EZ |
7369 | Specifies the line that begins the body of the function @var{function} |
7370 | in the file @var{filename}. You only need the file name with a | |
7371 | function name to avoid ambiguity when there are identically named | |
7372 | functions in different source files. | |
c906108c | 7373 | |
0f5238ed TT |
7374 | @item @var{label} |
7375 | Specifies the line at which the label named @var{label} appears. | |
7376 | @value{GDBN} searches for the label in the function corresponding to | |
7377 | the currently selected stack frame. If there is no current selected | |
7378 | stack frame (for instance, if the inferior is not running), then | |
7379 | @value{GDBN} will not search for a label. | |
7380 | ||
c906108c | 7381 | @item *@var{address} |
2a25a5ba EZ |
7382 | Specifies the program address @var{address}. For line-oriented |
7383 | commands, such as @code{list} and @code{edit}, this specifies a source | |
7384 | line that contains @var{address}. For @code{break} and other | |
7385 | breakpoint oriented commands, this can be used to set breakpoints in | |
7386 | parts of your program which do not have debugging information or | |
7387 | source files. | |
7388 | ||
7389 | Here @var{address} may be any expression valid in the current working | |
7390 | language (@pxref{Languages, working language}) that specifies a code | |
5fa54e5d EZ |
7391 | address. In addition, as a convenience, @value{GDBN} extends the |
7392 | semantics of expressions used in locations to cover the situations | |
7393 | that frequently happen during debugging. Here are the various forms | |
7394 | of @var{address}: | |
2a25a5ba EZ |
7395 | |
7396 | @table @code | |
7397 | @item @var{expression} | |
7398 | Any expression valid in the current working language. | |
7399 | ||
7400 | @item @var{funcaddr} | |
7401 | An address of a function or procedure derived from its name. In C, | |
7402 | C@t{++}, Java, Objective-C, Fortran, minimal, and assembly, this is | |
7403 | simply the function's name @var{function} (and actually a special case | |
7404 | of a valid expression). In Pascal and Modula-2, this is | |
7405 | @code{&@var{function}}. In Ada, this is @code{@var{function}'Address} | |
7406 | (although the Pascal form also works). | |
7407 | ||
7408 | This form specifies the address of the function's first instruction, | |
7409 | before the stack frame and arguments have been set up. | |
7410 | ||
7411 | @item '@var{filename}'::@var{funcaddr} | |
7412 | Like @var{funcaddr} above, but also specifies the name of the source | |
7413 | file explicitly. This is useful if the name of the function does not | |
7414 | specify the function unambiguously, e.g., if there are several | |
7415 | functions with identical names in different source files. | |
c906108c SS |
7416 | @end table |
7417 | ||
62e5f89c SDJ |
7418 | @cindex breakpoint at static probe point |
7419 | @item -pstap|-probe-stap @r{[}@var{objfile}:@r{[}@var{provider}:@r{]}@r{]}@var{name} | |
7420 | The @sc{gnu}/Linux tool @code{SystemTap} provides a way for | |
7421 | applications to embed static probes. @xref{Static Probe Points}, for more | |
7422 | information on finding and using static probes. This form of linespec | |
7423 | specifies the location of such a static probe. | |
7424 | ||
7425 | If @var{objfile} is given, only probes coming from that shared library | |
7426 | or executable matching @var{objfile} as a regular expression are considered. | |
7427 | If @var{provider} is given, then only probes from that provider are considered. | |
7428 | If several probes match the spec, @value{GDBN} will insert a breakpoint at | |
7429 | each one of those probes. | |
7430 | ||
2a25a5ba EZ |
7431 | @end table |
7432 | ||
7433 | ||
87885426 | 7434 | @node Edit |
79a6e687 | 7435 | @section Editing Source Files |
87885426 FN |
7436 | @cindex editing source files |
7437 | ||
7438 | @kindex edit | |
7439 | @kindex e @r{(@code{edit})} | |
7440 | To edit the lines in a source file, use the @code{edit} command. | |
7441 | The editing program of your choice | |
7442 | is invoked with the current line set to | |
7443 | the active line in the program. | |
7444 | Alternatively, there are several ways to specify what part of the file you | |
2a25a5ba | 7445 | want to print if you want to see other parts of the program: |
87885426 FN |
7446 | |
7447 | @table @code | |
2a25a5ba EZ |
7448 | @item edit @var{location} |
7449 | Edit the source file specified by @code{location}. Editing starts at | |
7450 | that @var{location}, e.g., at the specified source line of the | |
7451 | specified file. @xref{Specify Location}, for all the possible forms | |
7452 | of the @var{location} argument; here are the forms of the @code{edit} | |
7453 | command most commonly used: | |
87885426 | 7454 | |
2a25a5ba | 7455 | @table @code |
87885426 FN |
7456 | @item edit @var{number} |
7457 | Edit the current source file with @var{number} as the active line number. | |
7458 | ||
7459 | @item edit @var{function} | |
7460 | Edit the file containing @var{function} at the beginning of its definition. | |
2a25a5ba | 7461 | @end table |
87885426 | 7462 | |
87885426 FN |
7463 | @end table |
7464 | ||
79a6e687 | 7465 | @subsection Choosing your Editor |
87885426 FN |
7466 | You can customize @value{GDBN} to use any editor you want |
7467 | @footnote{ | |
7468 | The only restriction is that your editor (say @code{ex}), recognizes the | |
7469 | following command-line syntax: | |
10998722 | 7470 | @smallexample |
87885426 | 7471 | ex +@var{number} file |
10998722 | 7472 | @end smallexample |
15387254 EZ |
7473 | The optional numeric value +@var{number} specifies the number of the line in |
7474 | the file where to start editing.}. | |
7475 | By default, it is @file{@value{EDITOR}}, but you can change this | |
10998722 AC |
7476 | by setting the environment variable @code{EDITOR} before using |
7477 | @value{GDBN}. For example, to configure @value{GDBN} to use the | |
7478 | @code{vi} editor, you could use these commands with the @code{sh} shell: | |
7479 | @smallexample | |
87885426 FN |
7480 | EDITOR=/usr/bin/vi |
7481 | export EDITOR | |
15387254 | 7482 | gdb @dots{} |
10998722 | 7483 | @end smallexample |
87885426 | 7484 | or in the @code{csh} shell, |
10998722 | 7485 | @smallexample |
87885426 | 7486 | setenv EDITOR /usr/bin/vi |
15387254 | 7487 | gdb @dots{} |
10998722 | 7488 | @end smallexample |
87885426 | 7489 | |
6d2ebf8b | 7490 | @node Search |
79a6e687 | 7491 | @section Searching Source Files |
15387254 | 7492 | @cindex searching source files |
c906108c SS |
7493 | |
7494 | There are two commands for searching through the current source file for a | |
7495 | regular expression. | |
7496 | ||
7497 | @table @code | |
7498 | @kindex search | |
7499 | @kindex forward-search | |
1e96de83 | 7500 | @kindex fo @r{(@code{forward-search})} |
c906108c SS |
7501 | @item forward-search @var{regexp} |
7502 | @itemx search @var{regexp} | |
7503 | The command @samp{forward-search @var{regexp}} checks each line, | |
7504 | starting with the one following the last line listed, for a match for | |
5d161b24 | 7505 | @var{regexp}. It lists the line that is found. You can use the |
c906108c SS |
7506 | synonym @samp{search @var{regexp}} or abbreviate the command name as |
7507 | @code{fo}. | |
7508 | ||
09d4efe1 | 7509 | @kindex reverse-search |
c906108c SS |
7510 | @item reverse-search @var{regexp} |
7511 | The command @samp{reverse-search @var{regexp}} checks each line, starting | |
7512 | with the one before the last line listed and going backward, for a match | |
7513 | for @var{regexp}. It lists the line that is found. You can abbreviate | |
7514 | this command as @code{rev}. | |
7515 | @end table | |
c906108c | 7516 | |
6d2ebf8b | 7517 | @node Source Path |
79a6e687 | 7518 | @section Specifying Source Directories |
c906108c SS |
7519 | |
7520 | @cindex source path | |
7521 | @cindex directories for source files | |
7522 | Executable programs sometimes do not record the directories of the source | |
7523 | files from which they were compiled, just the names. Even when they do, | |
7524 | the directories could be moved between the compilation and your debugging | |
7525 | session. @value{GDBN} has a list of directories to search for source files; | |
7526 | this is called the @dfn{source path}. Each time @value{GDBN} wants a source file, | |
7527 | it tries all the directories in the list, in the order they are present | |
0b66e38c EZ |
7528 | in the list, until it finds a file with the desired name. |
7529 | ||
7530 | For example, suppose an executable references the file | |
7531 | @file{/usr/src/foo-1.0/lib/foo.c}, and our source path is | |
7532 | @file{/mnt/cross}. The file is first looked up literally; if this | |
7533 | fails, @file{/mnt/cross/usr/src/foo-1.0/lib/foo.c} is tried; if this | |
7534 | fails, @file{/mnt/cross/foo.c} is opened; if this fails, an error | |
7535 | message is printed. @value{GDBN} does not look up the parts of the | |
7536 | source file name, such as @file{/mnt/cross/src/foo-1.0/lib/foo.c}. | |
7537 | Likewise, the subdirectories of the source path are not searched: if | |
7538 | the source path is @file{/mnt/cross}, and the binary refers to | |
7539 | @file{foo.c}, @value{GDBN} would not find it under | |
7540 | @file{/mnt/cross/usr/src/foo-1.0/lib}. | |
7541 | ||
7542 | Plain file names, relative file names with leading directories, file | |
7543 | names containing dots, etc.@: are all treated as described above; for | |
7544 | instance, if the source path is @file{/mnt/cross}, and the source file | |
7545 | is recorded as @file{../lib/foo.c}, @value{GDBN} would first try | |
7546 | @file{../lib/foo.c}, then @file{/mnt/cross/../lib/foo.c}, and after | |
7547 | that---@file{/mnt/cross/foo.c}. | |
7548 | ||
7549 | Note that the executable search path is @emph{not} used to locate the | |
cd852561 | 7550 | source files. |
c906108c SS |
7551 | |
7552 | Whenever you reset or rearrange the source path, @value{GDBN} clears out | |
7553 | any information it has cached about where source files are found and where | |
7554 | each line is in the file. | |
7555 | ||
7556 | @kindex directory | |
7557 | @kindex dir | |
d4f3574e SS |
7558 | When you start @value{GDBN}, its source path includes only @samp{cdir} |
7559 | and @samp{cwd}, in that order. | |
c906108c SS |
7560 | To add other directories, use the @code{directory} command. |
7561 | ||
4b505b12 AS |
7562 | The search path is used to find both program source files and @value{GDBN} |
7563 | script files (read using the @samp{-command} option and @samp{source} command). | |
7564 | ||
30daae6c JB |
7565 | In addition to the source path, @value{GDBN} provides a set of commands |
7566 | that manage a list of source path substitution rules. A @dfn{substitution | |
7567 | rule} specifies how to rewrite source directories stored in the program's | |
7568 | debug information in case the sources were moved to a different | |
7569 | directory between compilation and debugging. A rule is made of | |
7570 | two strings, the first specifying what needs to be rewritten in | |
7571 | the path, and the second specifying how it should be rewritten. | |
7572 | In @ref{set substitute-path}, we name these two parts @var{from} and | |
7573 | @var{to} respectively. @value{GDBN} does a simple string replacement | |
7574 | of @var{from} with @var{to} at the start of the directory part of the | |
7575 | source file name, and uses that result instead of the original file | |
7576 | name to look up the sources. | |
7577 | ||
7578 | Using the previous example, suppose the @file{foo-1.0} tree has been | |
7579 | moved from @file{/usr/src} to @file{/mnt/cross}, then you can tell | |
3f94c067 | 7580 | @value{GDBN} to replace @file{/usr/src} in all source path names with |
30daae6c JB |
7581 | @file{/mnt/cross}. The first lookup will then be |
7582 | @file{/mnt/cross/foo-1.0/lib/foo.c} in place of the original location | |
7583 | of @file{/usr/src/foo-1.0/lib/foo.c}. To define a source path | |
7584 | substitution rule, use the @code{set substitute-path} command | |
7585 | (@pxref{set substitute-path}). | |
7586 | ||
7587 | To avoid unexpected substitution results, a rule is applied only if the | |
7588 | @var{from} part of the directory name ends at a directory separator. | |
7589 | For instance, a rule substituting @file{/usr/source} into | |
7590 | @file{/mnt/cross} will be applied to @file{/usr/source/foo-1.0} but | |
7591 | not to @file{/usr/sourceware/foo-2.0}. And because the substitution | |
d3e8051b | 7592 | is applied only at the beginning of the directory name, this rule will |
30daae6c JB |
7593 | not be applied to @file{/root/usr/source/baz.c} either. |
7594 | ||
7595 | In many cases, you can achieve the same result using the @code{directory} | |
7596 | command. However, @code{set substitute-path} can be more efficient in | |
7597 | the case where the sources are organized in a complex tree with multiple | |
7598 | subdirectories. With the @code{directory} command, you need to add each | |
7599 | subdirectory of your project. If you moved the entire tree while | |
7600 | preserving its internal organization, then @code{set substitute-path} | |
7601 | allows you to direct the debugger to all the sources with one single | |
7602 | command. | |
7603 | ||
7604 | @code{set substitute-path} is also more than just a shortcut command. | |
7605 | The source path is only used if the file at the original location no | |
7606 | longer exists. On the other hand, @code{set substitute-path} modifies | |
7607 | the debugger behavior to look at the rewritten location instead. So, if | |
7608 | for any reason a source file that is not relevant to your executable is | |
7609 | located at the original location, a substitution rule is the only | |
3f94c067 | 7610 | method available to point @value{GDBN} at the new location. |
30daae6c | 7611 | |
29b0e8a2 JM |
7612 | @cindex @samp{--with-relocated-sources} |
7613 | @cindex default source path substitution | |
7614 | You can configure a default source path substitution rule by | |
7615 | configuring @value{GDBN} with the | |
7616 | @samp{--with-relocated-sources=@var{dir}} option. The @var{dir} | |
7617 | should be the name of a directory under @value{GDBN}'s configured | |
7618 | prefix (set with @samp{--prefix} or @samp{--exec-prefix}), and | |
7619 | directory names in debug information under @var{dir} will be adjusted | |
7620 | automatically if the installed @value{GDBN} is moved to a new | |
7621 | location. This is useful if @value{GDBN}, libraries or executables | |
7622 | with debug information and corresponding source code are being moved | |
7623 | together. | |
7624 | ||
c906108c SS |
7625 | @table @code |
7626 | @item directory @var{dirname} @dots{} | |
7627 | @item dir @var{dirname} @dots{} | |
7628 | Add directory @var{dirname} to the front of the source path. Several | |
d4f3574e SS |
7629 | directory names may be given to this command, separated by @samp{:} |
7630 | (@samp{;} on MS-DOS and MS-Windows, where @samp{:} usually appears as | |
7631 | part of absolute file names) or | |
c906108c SS |
7632 | whitespace. You may specify a directory that is already in the source |
7633 | path; this moves it forward, so @value{GDBN} searches it sooner. | |
7634 | ||
7635 | @kindex cdir | |
7636 | @kindex cwd | |
41afff9a | 7637 | @vindex $cdir@r{, convenience variable} |
d3e8051b | 7638 | @vindex $cwd@r{, convenience variable} |
c906108c SS |
7639 | @cindex compilation directory |
7640 | @cindex current directory | |
7641 | @cindex working directory | |
7642 | @cindex directory, current | |
7643 | @cindex directory, compilation | |
7644 | You can use the string @samp{$cdir} to refer to the compilation | |
7645 | directory (if one is recorded), and @samp{$cwd} to refer to the current | |
7646 | working directory. @samp{$cwd} is not the same as @samp{.}---the former | |
7647 | tracks the current working directory as it changes during your @value{GDBN} | |
7648 | session, while the latter is immediately expanded to the current | |
7649 | directory at the time you add an entry to the source path. | |
7650 | ||
7651 | @item directory | |
cd852561 | 7652 | Reset the source path to its default value (@samp{$cdir:$cwd} on Unix systems). This requires confirmation. |
c906108c SS |
7653 | |
7654 | @c RET-repeat for @code{directory} is explicitly disabled, but since | |
7655 | @c repeating it would be a no-op we do not say that. (thanks to RMS) | |
7656 | ||
99e7ae30 DE |
7657 | @item set directories @var{path-list} |
7658 | @kindex set directories | |
7659 | Set the source path to @var{path-list}. | |
7660 | @samp{$cdir:$cwd} are added if missing. | |
7661 | ||
c906108c SS |
7662 | @item show directories |
7663 | @kindex show directories | |
7664 | Print the source path: show which directories it contains. | |
30daae6c JB |
7665 | |
7666 | @anchor{set substitute-path} | |
7667 | @item set substitute-path @var{from} @var{to} | |
7668 | @kindex set substitute-path | |
7669 | Define a source path substitution rule, and add it at the end of the | |
7670 | current list of existing substitution rules. If a rule with the same | |
7671 | @var{from} was already defined, then the old rule is also deleted. | |
7672 | ||
7673 | For example, if the file @file{/foo/bar/baz.c} was moved to | |
7674 | @file{/mnt/cross/baz.c}, then the command | |
7675 | ||
7676 | @smallexample | |
7677 | (@value{GDBP}) set substitute-path /usr/src /mnt/cross | |
7678 | @end smallexample | |
7679 | ||
7680 | @noindent | |
7681 | will tell @value{GDBN} to replace @samp{/usr/src} with | |
7682 | @samp{/mnt/cross}, which will allow @value{GDBN} to find the file | |
7683 | @file{baz.c} even though it was moved. | |
7684 | ||
7685 | In the case when more than one substitution rule have been defined, | |
7686 | the rules are evaluated one by one in the order where they have been | |
7687 | defined. The first one matching, if any, is selected to perform | |
7688 | the substitution. | |
7689 | ||
7690 | For instance, if we had entered the following commands: | |
7691 | ||
7692 | @smallexample | |
7693 | (@value{GDBP}) set substitute-path /usr/src/include /mnt/include | |
7694 | (@value{GDBP}) set substitute-path /usr/src /mnt/src | |
7695 | @end smallexample | |
7696 | ||
7697 | @noindent | |
7698 | @value{GDBN} would then rewrite @file{/usr/src/include/defs.h} into | |
7699 | @file{/mnt/include/defs.h} by using the first rule. However, it would | |
7700 | use the second rule to rewrite @file{/usr/src/lib/foo.c} into | |
7701 | @file{/mnt/src/lib/foo.c}. | |
7702 | ||
7703 | ||
7704 | @item unset substitute-path [path] | |
7705 | @kindex unset substitute-path | |
7706 | If a path is specified, search the current list of substitution rules | |
7707 | for a rule that would rewrite that path. Delete that rule if found. | |
7708 | A warning is emitted by the debugger if no rule could be found. | |
7709 | ||
7710 | If no path is specified, then all substitution rules are deleted. | |
7711 | ||
7712 | @item show substitute-path [path] | |
7713 | @kindex show substitute-path | |
7714 | If a path is specified, then print the source path substitution rule | |
7715 | which would rewrite that path, if any. | |
7716 | ||
7717 | If no path is specified, then print all existing source path substitution | |
7718 | rules. | |
7719 | ||
c906108c SS |
7720 | @end table |
7721 | ||
7722 | If your source path is cluttered with directories that are no longer of | |
7723 | interest, @value{GDBN} may sometimes cause confusion by finding the wrong | |
7724 | versions of source. You can correct the situation as follows: | |
7725 | ||
7726 | @enumerate | |
7727 | @item | |
cd852561 | 7728 | Use @code{directory} with no argument to reset the source path to its default value. |
c906108c SS |
7729 | |
7730 | @item | |
7731 | Use @code{directory} with suitable arguments to reinstall the | |
7732 | directories you want in the source path. You can add all the | |
7733 | directories in one command. | |
7734 | @end enumerate | |
7735 | ||
6d2ebf8b | 7736 | @node Machine Code |
79a6e687 | 7737 | @section Source and Machine Code |
15387254 | 7738 | @cindex source line and its code address |
c906108c SS |
7739 | |
7740 | You can use the command @code{info line} to map source lines to program | |
7741 | addresses (and vice versa), and the command @code{disassemble} to display | |
91440f57 HZ |
7742 | a range of addresses as machine instructions. You can use the command |
7743 | @code{set disassemble-next-line} to set whether to disassemble next | |
7744 | source line when execution stops. When run under @sc{gnu} Emacs | |
d4f3574e | 7745 | mode, the @code{info line} command causes the arrow to point to the |
5d161b24 | 7746 | line specified. Also, @code{info line} prints addresses in symbolic form as |
c906108c SS |
7747 | well as hex. |
7748 | ||
7749 | @table @code | |
7750 | @kindex info line | |
7751 | @item info line @var{linespec} | |
7752 | Print the starting and ending addresses of the compiled code for | |
7753 | source line @var{linespec}. You can specify source lines in any of | |
2a25a5ba | 7754 | the ways documented in @ref{Specify Location}. |
c906108c SS |
7755 | @end table |
7756 | ||
7757 | For example, we can use @code{info line} to discover the location of | |
7758 | the object code for the first line of function | |
7759 | @code{m4_changequote}: | |
7760 | ||
d4f3574e SS |
7761 | @c FIXME: I think this example should also show the addresses in |
7762 | @c symbolic form, as they usually would be displayed. | |
c906108c | 7763 | @smallexample |
96a2c332 | 7764 | (@value{GDBP}) info line m4_changequote |
c906108c SS |
7765 | Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350. |
7766 | @end smallexample | |
7767 | ||
7768 | @noindent | |
15387254 | 7769 | @cindex code address and its source line |
c906108c SS |
7770 | We can also inquire (using @code{*@var{addr}} as the form for |
7771 | @var{linespec}) what source line covers a particular address: | |
7772 | @smallexample | |
7773 | (@value{GDBP}) info line *0x63ff | |
7774 | Line 926 of "builtin.c" starts at pc 0x63e4 and ends at 0x6404. | |
7775 | @end smallexample | |
7776 | ||
7777 | @cindex @code{$_} and @code{info line} | |
15387254 | 7778 | @cindex @code{x} command, default address |
41afff9a | 7779 | @kindex x@r{(examine), and} info line |
c906108c SS |
7780 | After @code{info line}, the default address for the @code{x} command |
7781 | is changed to the starting address of the line, so that @samp{x/i} is | |
7782 | sufficient to begin examining the machine code (@pxref{Memory, | |
79a6e687 | 7783 | ,Examining Memory}). Also, this address is saved as the value of the |
c906108c | 7784 | convenience variable @code{$_} (@pxref{Convenience Vars, ,Convenience |
79a6e687 | 7785 | Variables}). |
c906108c SS |
7786 | |
7787 | @table @code | |
7788 | @kindex disassemble | |
7789 | @cindex assembly instructions | |
7790 | @cindex instructions, assembly | |
7791 | @cindex machine instructions | |
7792 | @cindex listing machine instructions | |
7793 | @item disassemble | |
d14508fe | 7794 | @itemx disassemble /m |
9b117ef3 | 7795 | @itemx disassemble /r |
c906108c | 7796 | This specialized command dumps a range of memory as machine |
d14508fe | 7797 | instructions. It can also print mixed source+disassembly by specifying |
9b117ef3 HZ |
7798 | the @code{/m} modifier and print the raw instructions in hex as well as |
7799 | in symbolic form by specifying the @code{/r}. | |
d14508fe | 7800 | The default memory range is the function surrounding the |
c906108c SS |
7801 | program counter of the selected frame. A single argument to this |
7802 | command is a program counter value; @value{GDBN} dumps the function | |
21a0512e PP |
7803 | surrounding this value. When two arguments are given, they should |
7804 | be separated by a comma, possibly surrounded by whitespace. The | |
53a71c06 CR |
7805 | arguments specify a range of addresses to dump, in one of two forms: |
7806 | ||
7807 | @table @code | |
7808 | @item @var{start},@var{end} | |
7809 | the addresses from @var{start} (inclusive) to @var{end} (exclusive) | |
7810 | @item @var{start},+@var{length} | |
7811 | the addresses from @var{start} (inclusive) to | |
7812 | @code{@var{start}+@var{length}} (exclusive). | |
7813 | @end table | |
7814 | ||
7815 | @noindent | |
7816 | When 2 arguments are specified, the name of the function is also | |
7817 | printed (since there could be several functions in the given range). | |
21a0512e PP |
7818 | |
7819 | The argument(s) can be any expression yielding a numeric value, such as | |
7820 | @samp{0x32c4}, @samp{&main+10} or @samp{$pc - 8}. | |
2b28d209 PP |
7821 | |
7822 | If the range of memory being disassembled contains current program counter, | |
7823 | the instruction at that location is shown with a @code{=>} marker. | |
c906108c SS |
7824 | @end table |
7825 | ||
c906108c SS |
7826 | The following example shows the disassembly of a range of addresses of |
7827 | HP PA-RISC 2.0 code: | |
7828 | ||
7829 | @smallexample | |
21a0512e | 7830 | (@value{GDBP}) disas 0x32c4, 0x32e4 |
c906108c | 7831 | Dump of assembler code from 0x32c4 to 0x32e4: |
2b28d209 PP |
7832 | 0x32c4 <main+204>: addil 0,dp |
7833 | 0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26 | |
7834 | 0x32cc <main+212>: ldil 0x3000,r31 | |
7835 | 0x32d0 <main+216>: ble 0x3f8(sr4,r31) | |
7836 | 0x32d4 <main+220>: ldo 0(r31),rp | |
7837 | 0x32d8 <main+224>: addil -0x800,dp | |
7838 | 0x32dc <main+228>: ldo 0x588(r1),r26 | |
7839 | 0x32e0 <main+232>: ldil 0x3000,r31 | |
c906108c SS |
7840 | End of assembler dump. |
7841 | @end smallexample | |
c906108c | 7842 | |
2b28d209 PP |
7843 | Here is an example showing mixed source+assembly for Intel x86, when the |
7844 | program is stopped just after function prologue: | |
d14508fe DE |
7845 | |
7846 | @smallexample | |
7847 | (@value{GDBP}) disas /m main | |
7848 | Dump of assembler code for function main: | |
7849 | 5 @{ | |
9c419145 PP |
7850 | 0x08048330 <+0>: push %ebp |
7851 | 0x08048331 <+1>: mov %esp,%ebp | |
7852 | 0x08048333 <+3>: sub $0x8,%esp | |
7853 | 0x08048336 <+6>: and $0xfffffff0,%esp | |
7854 | 0x08048339 <+9>: sub $0x10,%esp | |
d14508fe DE |
7855 | |
7856 | 6 printf ("Hello.\n"); | |
9c419145 PP |
7857 | => 0x0804833c <+12>: movl $0x8048440,(%esp) |
7858 | 0x08048343 <+19>: call 0x8048284 <puts@@plt> | |
d14508fe DE |
7859 | |
7860 | 7 return 0; | |
7861 | 8 @} | |
9c419145 PP |
7862 | 0x08048348 <+24>: mov $0x0,%eax |
7863 | 0x0804834d <+29>: leave | |
7864 | 0x0804834e <+30>: ret | |
d14508fe DE |
7865 | |
7866 | End of assembler dump. | |
7867 | @end smallexample | |
7868 | ||
53a71c06 CR |
7869 | Here is another example showing raw instructions in hex for AMD x86-64, |
7870 | ||
7871 | @smallexample | |
7872 | (gdb) disas /r 0x400281,+10 | |
7873 | Dump of assembler code from 0x400281 to 0x40028b: | |
7874 | 0x0000000000400281: 38 36 cmp %dh,(%rsi) | |
7875 | 0x0000000000400283: 2d 36 34 2e 73 sub $0x732e3436,%eax | |
7876 | 0x0000000000400288: 6f outsl %ds:(%rsi),(%dx) | |
7877 | 0x0000000000400289: 2e 32 00 xor %cs:(%rax),%al | |
7878 | End of assembler dump. | |
7879 | @end smallexample | |
7880 | ||
7e1e0340 DE |
7881 | Addresses cannot be specified as a linespec (@pxref{Specify Location}). |
7882 | So, for example, if you want to disassemble function @code{bar} | |
7883 | in file @file{foo.c}, you must type @samp{disassemble 'foo.c'::bar} | |
7884 | and not @samp{disassemble foo.c:bar}. | |
7885 | ||
c906108c SS |
7886 | Some architectures have more than one commonly-used set of instruction |
7887 | mnemonics or other syntax. | |
7888 | ||
76d17f34 EZ |
7889 | For programs that were dynamically linked and use shared libraries, |
7890 | instructions that call functions or branch to locations in the shared | |
7891 | libraries might show a seemingly bogus location---it's actually a | |
7892 | location of the relocation table. On some architectures, @value{GDBN} | |
7893 | might be able to resolve these to actual function names. | |
7894 | ||
c906108c | 7895 | @table @code |
d4f3574e | 7896 | @kindex set disassembly-flavor |
d4f3574e SS |
7897 | @cindex Intel disassembly flavor |
7898 | @cindex AT&T disassembly flavor | |
7899 | @item set disassembly-flavor @var{instruction-set} | |
c906108c SS |
7900 | Select the instruction set to use when disassembling the |
7901 | program via the @code{disassemble} or @code{x/i} commands. | |
7902 | ||
7903 | Currently this command is only defined for the Intel x86 family. You | |
d4f3574e SS |
7904 | can set @var{instruction-set} to either @code{intel} or @code{att}. |
7905 | The default is @code{att}, the AT&T flavor used by default by Unix | |
7906 | assemblers for x86-based targets. | |
9c16f35a EZ |
7907 | |
7908 | @kindex show disassembly-flavor | |
7909 | @item show disassembly-flavor | |
7910 | Show the current setting of the disassembly flavor. | |
c906108c SS |
7911 | @end table |
7912 | ||
91440f57 HZ |
7913 | @table @code |
7914 | @kindex set disassemble-next-line | |
7915 | @kindex show disassemble-next-line | |
7916 | @item set disassemble-next-line | |
7917 | @itemx show disassemble-next-line | |
32ae1842 EZ |
7918 | Control whether or not @value{GDBN} will disassemble the next source |
7919 | line or instruction when execution stops. If ON, @value{GDBN} will | |
7920 | display disassembly of the next source line when execution of the | |
7921 | program being debugged stops. This is @emph{in addition} to | |
7922 | displaying the source line itself, which @value{GDBN} always does if | |
7923 | possible. If the next source line cannot be displayed for some reason | |
7924 | (e.g., if @value{GDBN} cannot find the source file, or there's no line | |
7925 | info in the debug info), @value{GDBN} will display disassembly of the | |
7926 | next @emph{instruction} instead of showing the next source line. If | |
7927 | AUTO, @value{GDBN} will display disassembly of next instruction only | |
7928 | if the source line cannot be displayed. This setting causes | |
7929 | @value{GDBN} to display some feedback when you step through a function | |
7930 | with no line info or whose source file is unavailable. The default is | |
7931 | OFF, which means never display the disassembly of the next line or | |
7932 | instruction. | |
91440f57 HZ |
7933 | @end table |
7934 | ||
c906108c | 7935 | |
6d2ebf8b | 7936 | @node Data |
c906108c SS |
7937 | @chapter Examining Data |
7938 | ||
7939 | @cindex printing data | |
7940 | @cindex examining data | |
7941 | @kindex print | |
7942 | @kindex inspect | |
c906108c | 7943 | The usual way to examine data in your program is with the @code{print} |
7a292a7a SS |
7944 | command (abbreviated @code{p}), or its synonym @code{inspect}. It |
7945 | evaluates and prints the value of an expression of the language your | |
7946 | program is written in (@pxref{Languages, ,Using @value{GDBN} with | |
78e2826b TT |
7947 | Different Languages}). It may also print the expression using a |
7948 | Python-based pretty-printer (@pxref{Pretty Printing}). | |
c906108c SS |
7949 | |
7950 | @table @code | |
d4f3574e SS |
7951 | @item print @var{expr} |
7952 | @itemx print /@var{f} @var{expr} | |
7953 | @var{expr} is an expression (in the source language). By default the | |
7954 | value of @var{expr} is printed in a format appropriate to its data type; | |
c906108c | 7955 | you can choose a different format by specifying @samp{/@var{f}}, where |
d4f3574e | 7956 | @var{f} is a letter specifying the format; see @ref{Output Formats,,Output |
79a6e687 | 7957 | Formats}. |
c906108c SS |
7958 | |
7959 | @item print | |
7960 | @itemx print /@var{f} | |
15387254 | 7961 | @cindex reprint the last value |
d4f3574e | 7962 | If you omit @var{expr}, @value{GDBN} displays the last value again (from the |
79a6e687 | 7963 | @dfn{value history}; @pxref{Value History, ,Value History}). This allows you to |
c906108c SS |
7964 | conveniently inspect the same value in an alternative format. |
7965 | @end table | |
7966 | ||
7967 | A more low-level way of examining data is with the @code{x} command. | |
7968 | It examines data in memory at a specified address and prints it in a | |
79a6e687 | 7969 | specified format. @xref{Memory, ,Examining Memory}. |
c906108c | 7970 | |
7a292a7a | 7971 | If you are interested in information about types, or about how the |
d4f3574e SS |
7972 | fields of a struct or a class are declared, use the @code{ptype @var{exp}} |
7973 | command rather than @code{print}. @xref{Symbols, ,Examining the Symbol | |
7a292a7a | 7974 | Table}. |
c906108c | 7975 | |
06fc020f SCR |
7976 | @cindex exploring hierarchical data structures |
7977 | @kindex explore | |
7978 | Another way of examining values of expressions and type information is | |
7979 | through the Python extension command @code{explore} (available only if | |
7980 | the @value{GDBN} build is configured with @code{--with-python}). It | |
7981 | offers an interactive way to start at the highest level (or, the most | |
7982 | abstract level) of the data type of an expression (or, the data type | |
7983 | itself) and explore all the way down to leaf scalar values/fields | |
7984 | embedded in the higher level data types. | |
7985 | ||
7986 | @table @code | |
7987 | @item explore @var{arg} | |
7988 | @var{arg} is either an expression (in the source language), or a type | |
7989 | visible in the current context of the program being debugged. | |
7990 | @end table | |
7991 | ||
7992 | The working of the @code{explore} command can be illustrated with an | |
7993 | example. If a data type @code{struct ComplexStruct} is defined in your | |
7994 | C program as | |
7995 | ||
7996 | @smallexample | |
7997 | struct SimpleStruct | |
7998 | @{ | |
7999 | int i; | |
8000 | double d; | |
8001 | @}; | |
8002 | ||
8003 | struct ComplexStruct | |
8004 | @{ | |
8005 | struct SimpleStruct *ss_p; | |
8006 | int arr[10]; | |
8007 | @}; | |
8008 | @end smallexample | |
8009 | ||
8010 | @noindent | |
8011 | followed by variable declarations as | |
8012 | ||
8013 | @smallexample | |
8014 | struct SimpleStruct ss = @{ 10, 1.11 @}; | |
8015 | struct ComplexStruct cs = @{ &ss, @{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 @} @}; | |
8016 | @end smallexample | |
8017 | ||
8018 | @noindent | |
8019 | then, the value of the variable @code{cs} can be explored using the | |
8020 | @code{explore} command as follows. | |
8021 | ||
8022 | @smallexample | |
8023 | (gdb) explore cs | |
8024 | The value of `cs' is a struct/class of type `struct ComplexStruct' with | |
8025 | the following fields: | |
8026 | ||
8027 | ss_p = <Enter 0 to explore this field of type `struct SimpleStruct *'> | |
8028 | arr = <Enter 1 to explore this field of type `int [10]'> | |
8029 | ||
8030 | Enter the field number of choice: | |
8031 | @end smallexample | |
8032 | ||
8033 | @noindent | |
8034 | Since the fields of @code{cs} are not scalar values, you are being | |
8035 | prompted to chose the field you want to explore. Let's say you choose | |
8036 | the field @code{ss_p} by entering @code{0}. Then, since this field is a | |
8037 | pointer, you will be asked if it is pointing to a single value. From | |
8038 | the declaration of @code{cs} above, it is indeed pointing to a single | |
8039 | value, hence you enter @code{y}. If you enter @code{n}, then you will | |
8040 | be asked if it were pointing to an array of values, in which case this | |
8041 | field will be explored as if it were an array. | |
8042 | ||
8043 | @smallexample | |
8044 | `cs.ss_p' is a pointer to a value of type `struct SimpleStruct' | |
8045 | Continue exploring it as a pointer to a single value [y/n]: y | |
8046 | The value of `*(cs.ss_p)' is a struct/class of type `struct | |
8047 | SimpleStruct' with the following fields: | |
8048 | ||
8049 | i = 10 .. (Value of type `int') | |
8050 | d = 1.1100000000000001 .. (Value of type `double') | |
8051 | ||
8052 | Press enter to return to parent value: | |
8053 | @end smallexample | |
8054 | ||
8055 | @noindent | |
8056 | If the field @code{arr} of @code{cs} was chosen for exploration by | |
8057 | entering @code{1} earlier, then since it is as array, you will be | |
8058 | prompted to enter the index of the element in the array that you want | |
8059 | to explore. | |
8060 | ||
8061 | @smallexample | |
8062 | `cs.arr' is an array of `int'. | |
8063 | Enter the index of the element you want to explore in `cs.arr': 5 | |
8064 | ||
8065 | `(cs.arr)[5]' is a scalar value of type `int'. | |
8066 | ||
8067 | (cs.arr)[5] = 4 | |
8068 | ||
8069 | Press enter to return to parent value: | |
8070 | @end smallexample | |
8071 | ||
8072 | In general, at any stage of exploration, you can go deeper towards the | |
8073 | leaf values by responding to the prompts appropriately, or hit the | |
8074 | return key to return to the enclosing data structure (the @i{higher} | |
8075 | level data structure). | |
8076 | ||
8077 | Similar to exploring values, you can use the @code{explore} command to | |
8078 | explore types. Instead of specifying a value (which is typically a | |
8079 | variable name or an expression valid in the current context of the | |
8080 | program being debugged), you specify a type name. If you consider the | |
8081 | same example as above, your can explore the type | |
8082 | @code{struct ComplexStruct} by passing the argument | |
8083 | @code{struct ComplexStruct} to the @code{explore} command. | |
8084 | ||
8085 | @smallexample | |
8086 | (gdb) explore struct ComplexStruct | |
8087 | @end smallexample | |
8088 | ||
8089 | @noindent | |
8090 | By responding to the prompts appropriately in the subsequent interactive | |
8091 | session, you can explore the type @code{struct ComplexStruct} in a | |
8092 | manner similar to how the value @code{cs} was explored in the above | |
8093 | example. | |
8094 | ||
8095 | The @code{explore} command also has two sub-commands, | |
8096 | @code{explore value} and @code{explore type}. The former sub-command is | |
8097 | a way to explicitly specify that value exploration of the argument is | |
8098 | being invoked, while the latter is a way to explicitly specify that type | |
8099 | exploration of the argument is being invoked. | |
8100 | ||
8101 | @table @code | |
8102 | @item explore value @var{expr} | |
8103 | @cindex explore value | |
8104 | This sub-command of @code{explore} explores the value of the | |
8105 | expression @var{expr} (if @var{expr} is an expression valid in the | |
8106 | current context of the program being debugged). The behavior of this | |
8107 | command is identical to that of the behavior of the @code{explore} | |
8108 | command being passed the argument @var{expr}. | |
8109 | ||
8110 | @item explore type @var{arg} | |
8111 | @cindex explore type | |
8112 | This sub-command of @code{explore} explores the type of @var{arg} (if | |
8113 | @var{arg} is a type visible in the current context of program being | |
8114 | debugged), or the type of the value/expression @var{arg} (if @var{arg} | |
8115 | is an expression valid in the current context of the program being | |
8116 | debugged). If @var{arg} is a type, then the behavior of this command is | |
8117 | identical to that of the @code{explore} command being passed the | |
8118 | argument @var{arg}. If @var{arg} is an expression, then the behavior of | |
8119 | this command will be identical to that of the @code{explore} command | |
8120 | being passed the type of @var{arg} as the argument. | |
8121 | @end table | |
8122 | ||
c906108c SS |
8123 | @menu |
8124 | * Expressions:: Expressions | |
6ba66d6a | 8125 | * Ambiguous Expressions:: Ambiguous Expressions |
c906108c SS |
8126 | * Variables:: Program variables |
8127 | * Arrays:: Artificial arrays | |
8128 | * Output Formats:: Output formats | |
8129 | * Memory:: Examining memory | |
8130 | * Auto Display:: Automatic display | |
8131 | * Print Settings:: Print settings | |
4c374409 | 8132 | * Pretty Printing:: Python pretty printing |
c906108c SS |
8133 | * Value History:: Value history |
8134 | * Convenience Vars:: Convenience variables | |
a72c3253 | 8135 | * Convenience Funs:: Convenience functions |
c906108c | 8136 | * Registers:: Registers |
c906108c | 8137 | * Floating Point Hardware:: Floating point hardware |
53c69bd7 | 8138 | * Vector Unit:: Vector Unit |
721c2651 | 8139 | * OS Information:: Auxiliary data provided by operating system |
29e57380 | 8140 | * Memory Region Attributes:: Memory region attributes |
16d9dec6 | 8141 | * Dump/Restore Files:: Copy between memory and a file |
384ee23f | 8142 | * Core File Generation:: Cause a program dump its core |
a0eb71c5 KB |
8143 | * Character Sets:: Debugging programs that use a different |
8144 | character set than GDB does | |
b12039c6 | 8145 | * Caching Target Data:: Data caching for targets |
08388c79 | 8146 | * Searching Memory:: Searching memory for a sequence of bytes |
c906108c SS |
8147 | @end menu |
8148 | ||
6d2ebf8b | 8149 | @node Expressions |
c906108c SS |
8150 | @section Expressions |
8151 | ||
8152 | @cindex expressions | |
8153 | @code{print} and many other @value{GDBN} commands accept an expression and | |
8154 | compute its value. Any kind of constant, variable or operator defined | |
8155 | by the programming language you are using is valid in an expression in | |
e2e0bcd1 JB |
8156 | @value{GDBN}. This includes conditional expressions, function calls, |
8157 | casts, and string constants. It also includes preprocessor macros, if | |
8158 | you compiled your program to include this information; see | |
8159 | @ref{Compilation}. | |
c906108c | 8160 | |
15387254 | 8161 | @cindex arrays in expressions |
d4f3574e SS |
8162 | @value{GDBN} supports array constants in expressions input by |
8163 | the user. The syntax is @{@var{element}, @var{element}@dots{}@}. For example, | |
63092375 DJ |
8164 | you can use the command @code{print @{1, 2, 3@}} to create an array |
8165 | of three integers. If you pass an array to a function or assign it | |
8166 | to a program variable, @value{GDBN} copies the array to memory that | |
8167 | is @code{malloc}ed in the target program. | |
c906108c | 8168 | |
c906108c SS |
8169 | Because C is so widespread, most of the expressions shown in examples in |
8170 | this manual are in C. @xref{Languages, , Using @value{GDBN} with Different | |
8171 | Languages}, for information on how to use expressions in other | |
8172 | languages. | |
8173 | ||
8174 | In this section, we discuss operators that you can use in @value{GDBN} | |
8175 | expressions regardless of your programming language. | |
8176 | ||
15387254 | 8177 | @cindex casts, in expressions |
c906108c SS |
8178 | Casts are supported in all languages, not just in C, because it is so |
8179 | useful to cast a number into a pointer in order to examine a structure | |
8180 | at that address in memory. | |
8181 | @c FIXME: casts supported---Mod2 true? | |
c906108c SS |
8182 | |
8183 | @value{GDBN} supports these operators, in addition to those common | |
8184 | to programming languages: | |
8185 | ||
8186 | @table @code | |
8187 | @item @@ | |
8188 | @samp{@@} is a binary operator for treating parts of memory as arrays. | |
79a6e687 | 8189 | @xref{Arrays, ,Artificial Arrays}, for more information. |
c906108c SS |
8190 | |
8191 | @item :: | |
8192 | @samp{::} allows you to specify a variable in terms of the file or | |
79a6e687 | 8193 | function where it is defined. @xref{Variables, ,Program Variables}. |
c906108c SS |
8194 | |
8195 | @cindex @{@var{type}@} | |
8196 | @cindex type casting memory | |
8197 | @cindex memory, viewing as typed object | |
8198 | @cindex casts, to view memory | |
8199 | @item @{@var{type}@} @var{addr} | |
8200 | Refers to an object of type @var{type} stored at address @var{addr} in | |
697aa1b7 EZ |
8201 | memory. The address @var{addr} may be any expression whose value is |
8202 | an integer or pointer (but parentheses are required around binary | |
8203 | operators, just as in a cast). This construct is allowed regardless | |
8204 | of what kind of data is normally supposed to reside at @var{addr}. | |
c906108c SS |
8205 | @end table |
8206 | ||
6ba66d6a JB |
8207 | @node Ambiguous Expressions |
8208 | @section Ambiguous Expressions | |
8209 | @cindex ambiguous expressions | |
8210 | ||
8211 | Expressions can sometimes contain some ambiguous elements. For instance, | |
8212 | some programming languages (notably Ada, C@t{++} and Objective-C) permit | |
8213 | a single function name to be defined several times, for application in | |
8214 | different contexts. This is called @dfn{overloading}. Another example | |
8215 | involving Ada is generics. A @dfn{generic package} is similar to C@t{++} | |
8216 | templates and is typically instantiated several times, resulting in | |
8217 | the same function name being defined in different contexts. | |
8218 | ||
8219 | In some cases and depending on the language, it is possible to adjust | |
8220 | the expression to remove the ambiguity. For instance in C@t{++}, you | |
8221 | can specify the signature of the function you want to break on, as in | |
8222 | @kbd{break @var{function}(@var{types})}. In Ada, using the fully | |
8223 | qualified name of your function often makes the expression unambiguous | |
8224 | as well. | |
8225 | ||
8226 | When an ambiguity that needs to be resolved is detected, the debugger | |
8227 | has the capability to display a menu of numbered choices for each | |
8228 | possibility, and then waits for the selection with the prompt @samp{>}. | |
8229 | The first option is always @samp{[0] cancel}, and typing @kbd{0 @key{RET}} | |
8230 | aborts the current command. If the command in which the expression was | |
8231 | used allows more than one choice to be selected, the next option in the | |
8232 | menu is @samp{[1] all}, and typing @kbd{1 @key{RET}} selects all possible | |
8233 | choices. | |
8234 | ||
8235 | For example, the following session excerpt shows an attempt to set a | |
8236 | breakpoint at the overloaded symbol @code{String::after}. | |
8237 | We choose three particular definitions of that function name: | |
8238 | ||
8239 | @c FIXME! This is likely to change to show arg type lists, at least | |
8240 | @smallexample | |
8241 | @group | |
8242 | (@value{GDBP}) b String::after | |
8243 | [0] cancel | |
8244 | [1] all | |
8245 | [2] file:String.cc; line number:867 | |
8246 | [3] file:String.cc; line number:860 | |
8247 | [4] file:String.cc; line number:875 | |
8248 | [5] file:String.cc; line number:853 | |
8249 | [6] file:String.cc; line number:846 | |
8250 | [7] file:String.cc; line number:735 | |
8251 | > 2 4 6 | |
8252 | Breakpoint 1 at 0xb26c: file String.cc, line 867. | |
8253 | Breakpoint 2 at 0xb344: file String.cc, line 875. | |
8254 | Breakpoint 3 at 0xafcc: file String.cc, line 846. | |
8255 | Multiple breakpoints were set. | |
8256 | Use the "delete" command to delete unwanted | |
8257 | breakpoints. | |
8258 | (@value{GDBP}) | |
8259 | @end group | |
8260 | @end smallexample | |
8261 | ||
8262 | @table @code | |
8263 | @kindex set multiple-symbols | |
8264 | @item set multiple-symbols @var{mode} | |
8265 | @cindex multiple-symbols menu | |
8266 | ||
8267 | This option allows you to adjust the debugger behavior when an expression | |
8268 | is ambiguous. | |
8269 | ||
8270 | By default, @var{mode} is set to @code{all}. If the command with which | |
8271 | the expression is used allows more than one choice, then @value{GDBN} | |
8272 | automatically selects all possible choices. For instance, inserting | |
8273 | a breakpoint on a function using an ambiguous name results in a breakpoint | |
8274 | inserted on each possible match. However, if a unique choice must be made, | |
8275 | then @value{GDBN} uses the menu to help you disambiguate the expression. | |
8276 | For instance, printing the address of an overloaded function will result | |
8277 | in the use of the menu. | |
8278 | ||
8279 | When @var{mode} is set to @code{ask}, the debugger always uses the menu | |
8280 | when an ambiguity is detected. | |
8281 | ||
8282 | Finally, when @var{mode} is set to @code{cancel}, the debugger reports | |
8283 | an error due to the ambiguity and the command is aborted. | |
8284 | ||
8285 | @kindex show multiple-symbols | |
8286 | @item show multiple-symbols | |
8287 | Show the current value of the @code{multiple-symbols} setting. | |
8288 | @end table | |
8289 | ||
6d2ebf8b | 8290 | @node Variables |
79a6e687 | 8291 | @section Program Variables |
c906108c SS |
8292 | |
8293 | The most common kind of expression to use is the name of a variable | |
8294 | in your program. | |
8295 | ||
8296 | Variables in expressions are understood in the selected stack frame | |
79a6e687 | 8297 | (@pxref{Selection, ,Selecting a Frame}); they must be either: |
c906108c SS |
8298 | |
8299 | @itemize @bullet | |
8300 | @item | |
8301 | global (or file-static) | |
8302 | @end itemize | |
8303 | ||
5d161b24 | 8304 | @noindent or |
c906108c SS |
8305 | |
8306 | @itemize @bullet | |
8307 | @item | |
8308 | visible according to the scope rules of the | |
8309 | programming language from the point of execution in that frame | |
5d161b24 | 8310 | @end itemize |
c906108c SS |
8311 | |
8312 | @noindent This means that in the function | |
8313 | ||
474c8240 | 8314 | @smallexample |
c906108c SS |
8315 | foo (a) |
8316 | int a; | |
8317 | @{ | |
8318 | bar (a); | |
8319 | @{ | |
8320 | int b = test (); | |
8321 | bar (b); | |
8322 | @} | |
8323 | @} | |
474c8240 | 8324 | @end smallexample |
c906108c SS |
8325 | |
8326 | @noindent | |
8327 | you can examine and use the variable @code{a} whenever your program is | |
8328 | executing within the function @code{foo}, but you can only use or | |
8329 | examine the variable @code{b} while your program is executing inside | |
8330 | the block where @code{b} is declared. | |
8331 | ||
8332 | @cindex variable name conflict | |
8333 | There is an exception: you can refer to a variable or function whose | |
8334 | scope is a single source file even if the current execution point is not | |
8335 | in this file. But it is possible to have more than one such variable or | |
8336 | function with the same name (in different source files). If that | |
8337 | happens, referring to that name has unpredictable effects. If you wish, | |
72384ba3 | 8338 | you can specify a static variable in a particular function or file by |
15387254 | 8339 | using the colon-colon (@code{::}) notation: |
c906108c | 8340 | |
d4f3574e | 8341 | @cindex colon-colon, context for variables/functions |
12c27660 | 8342 | @ifnotinfo |
c906108c | 8343 | @c info cannot cope with a :: index entry, but why deprive hard copy readers? |
41afff9a | 8344 | @cindex @code{::}, context for variables/functions |
12c27660 | 8345 | @end ifnotinfo |
474c8240 | 8346 | @smallexample |
c906108c SS |
8347 | @var{file}::@var{variable} |
8348 | @var{function}::@var{variable} | |
474c8240 | 8349 | @end smallexample |
c906108c SS |
8350 | |
8351 | @noindent | |
8352 | Here @var{file} or @var{function} is the name of the context for the | |
8353 | static @var{variable}. In the case of file names, you can use quotes to | |
8354 | make sure @value{GDBN} parses the file name as a single word---for example, | |
8355 | to print a global value of @code{x} defined in @file{f2.c}: | |
8356 | ||
474c8240 | 8357 | @smallexample |
c906108c | 8358 | (@value{GDBP}) p 'f2.c'::x |
474c8240 | 8359 | @end smallexample |
c906108c | 8360 | |
72384ba3 PH |
8361 | The @code{::} notation is normally used for referring to |
8362 | static variables, since you typically disambiguate uses of local variables | |
8363 | in functions by selecting the appropriate frame and using the | |
8364 | simple name of the variable. However, you may also use this notation | |
8365 | to refer to local variables in frames enclosing the selected frame: | |
8366 | ||
8367 | @smallexample | |
8368 | void | |
8369 | foo (int a) | |
8370 | @{ | |
8371 | if (a < 10) | |
8372 | bar (a); | |
8373 | else | |
8374 | process (a); /* Stop here */ | |
8375 | @} | |
8376 | ||
8377 | int | |
8378 | bar (int a) | |
8379 | @{ | |
8380 | foo (a + 5); | |
8381 | @} | |
8382 | @end smallexample | |
8383 | ||
8384 | @noindent | |
8385 | For example, if there is a breakpoint at the commented line, | |
8386 | here is what you might see | |
8387 | when the program stops after executing the call @code{bar(0)}: | |
8388 | ||
8389 | @smallexample | |
8390 | (@value{GDBP}) p a | |
8391 | $1 = 10 | |
8392 | (@value{GDBP}) p bar::a | |
8393 | $2 = 5 | |
8394 | (@value{GDBP}) up 2 | |
8395 | #2 0x080483d0 in foo (a=5) at foobar.c:12 | |
8396 | (@value{GDBP}) p a | |
8397 | $3 = 5 | |
8398 | (@value{GDBP}) p bar::a | |
8399 | $4 = 0 | |
8400 | @end smallexample | |
8401 | ||
b37052ae | 8402 | @cindex C@t{++} scope resolution |
805e1f19 TT |
8403 | These uses of @samp{::} are very rarely in conflict with the very |
8404 | similar use of the same notation in C@t{++}. When they are in | |
8405 | conflict, the C@t{++} meaning takes precedence; however, this can be | |
8406 | overridden by quoting the file or function name with single quotes. | |
8407 | ||
8408 | For example, suppose the program is stopped in a method of a class | |
8409 | that has a field named @code{includefile}, and there is also an | |
8410 | include file named @file{includefile} that defines a variable, | |
8411 | @code{some_global}. | |
8412 | ||
8413 | @smallexample | |
8414 | (@value{GDBP}) p includefile | |
8415 | $1 = 23 | |
8416 | (@value{GDBP}) p includefile::some_global | |
8417 | A syntax error in expression, near `'. | |
8418 | (@value{GDBP}) p 'includefile'::some_global | |
8419 | $2 = 27 | |
8420 | @end smallexample | |
c906108c SS |
8421 | |
8422 | @cindex wrong values | |
8423 | @cindex variable values, wrong | |
15387254 EZ |
8424 | @cindex function entry/exit, wrong values of variables |
8425 | @cindex optimized code, wrong values of variables | |
c906108c SS |
8426 | @quotation |
8427 | @emph{Warning:} Occasionally, a local variable may appear to have the | |
8428 | wrong value at certain points in a function---just after entry to a new | |
8429 | scope, and just before exit. | |
8430 | @end quotation | |
8431 | You may see this problem when you are stepping by machine instructions. | |
8432 | This is because, on most machines, it takes more than one instruction to | |
8433 | set up a stack frame (including local variable definitions); if you are | |
8434 | stepping by machine instructions, variables may appear to have the wrong | |
8435 | values until the stack frame is completely built. On exit, it usually | |
8436 | also takes more than one machine instruction to destroy a stack frame; | |
8437 | after you begin stepping through that group of instructions, local | |
8438 | variable definitions may be gone. | |
8439 | ||
8440 | This may also happen when the compiler does significant optimizations. | |
8441 | To be sure of always seeing accurate values, turn off all optimization | |
8442 | when compiling. | |
8443 | ||
d4f3574e SS |
8444 | @cindex ``No symbol "foo" in current context'' |
8445 | Another possible effect of compiler optimizations is to optimize | |
8446 | unused variables out of existence, or assign variables to registers (as | |
8447 | opposed to memory addresses). Depending on the support for such cases | |
8448 | offered by the debug info format used by the compiler, @value{GDBN} | |
8449 | might not be able to display values for such local variables. If that | |
8450 | happens, @value{GDBN} will print a message like this: | |
8451 | ||
474c8240 | 8452 | @smallexample |
d4f3574e | 8453 | No symbol "foo" in current context. |
474c8240 | 8454 | @end smallexample |
d4f3574e SS |
8455 | |
8456 | To solve such problems, either recompile without optimizations, or use a | |
8457 | different debug info format, if the compiler supports several such | |
e0f8f636 TT |
8458 | formats. @xref{Compilation}, for more information on choosing compiler |
8459 | options. @xref{C, ,C and C@t{++}}, for more information about debug | |
8460 | info formats that are best suited to C@t{++} programs. | |
d4f3574e | 8461 | |
ab1adacd EZ |
8462 | If you ask to print an object whose contents are unknown to |
8463 | @value{GDBN}, e.g., because its data type is not completely specified | |
8464 | by the debug information, @value{GDBN} will say @samp{<incomplete | |
8465 | type>}. @xref{Symbols, incomplete type}, for more about this. | |
8466 | ||
36b11add JK |
8467 | If you append @kbd{@@entry} string to a function parameter name you get its |
8468 | value at the time the function got called. If the value is not available an | |
8469 | error message is printed. Entry values are available only with some compilers. | |
8470 | Entry values are normally also printed at the function parameter list according | |
8471 | to @ref{set print entry-values}. | |
8472 | ||
8473 | @smallexample | |
8474 | Breakpoint 1, d (i=30) at gdb.base/entry-value.c:29 | |
8475 | 29 i++; | |
8476 | (gdb) next | |
8477 | 30 e (i); | |
8478 | (gdb) print i | |
8479 | $1 = 31 | |
8480 | (gdb) print i@@entry | |
8481 | $2 = 30 | |
8482 | @end smallexample | |
8483 | ||
3a60f64e JK |
8484 | Strings are identified as arrays of @code{char} values without specified |
8485 | signedness. Arrays of either @code{signed char} or @code{unsigned char} get | |
8486 | printed as arrays of 1 byte sized integers. @code{-fsigned-char} or | |
8487 | @code{-funsigned-char} @value{NGCC} options have no effect as @value{GDBN} | |
8488 | defines literal string type @code{"char"} as @code{char} without a sign. | |
8489 | For program code | |
8490 | ||
8491 | @smallexample | |
8492 | char var0[] = "A"; | |
8493 | signed char var1[] = "A"; | |
8494 | @end smallexample | |
8495 | ||
8496 | You get during debugging | |
8497 | @smallexample | |
8498 | (gdb) print var0 | |
8499 | $1 = "A" | |
8500 | (gdb) print var1 | |
8501 | $2 = @{65 'A', 0 '\0'@} | |
8502 | @end smallexample | |
8503 | ||
6d2ebf8b | 8504 | @node Arrays |
79a6e687 | 8505 | @section Artificial Arrays |
c906108c SS |
8506 | |
8507 | @cindex artificial array | |
15387254 | 8508 | @cindex arrays |
41afff9a | 8509 | @kindex @@@r{, referencing memory as an array} |
c906108c SS |
8510 | It is often useful to print out several successive objects of the |
8511 | same type in memory; a section of an array, or an array of | |
8512 | dynamically determined size for which only a pointer exists in the | |
8513 | program. | |
8514 | ||
8515 | You can do this by referring to a contiguous span of memory as an | |
8516 | @dfn{artificial array}, using the binary operator @samp{@@}. The left | |
8517 | operand of @samp{@@} should be the first element of the desired array | |
8518 | and be an individual object. The right operand should be the desired length | |
8519 | of the array. The result is an array value whose elements are all of | |
8520 | the type of the left argument. The first element is actually the left | |
8521 | argument; the second element comes from bytes of memory immediately | |
8522 | following those that hold the first element, and so on. Here is an | |
8523 | example. If a program says | |
8524 | ||
474c8240 | 8525 | @smallexample |
c906108c | 8526 | int *array = (int *) malloc (len * sizeof (int)); |
474c8240 | 8527 | @end smallexample |
c906108c SS |
8528 | |
8529 | @noindent | |
8530 | you can print the contents of @code{array} with | |
8531 | ||
474c8240 | 8532 | @smallexample |
c906108c | 8533 | p *array@@len |
474c8240 | 8534 | @end smallexample |
c906108c SS |
8535 | |
8536 | The left operand of @samp{@@} must reside in memory. Array values made | |
8537 | with @samp{@@} in this way behave just like other arrays in terms of | |
8538 | subscripting, and are coerced to pointers when used in expressions. | |
8539 | Artificial arrays most often appear in expressions via the value history | |
79a6e687 | 8540 | (@pxref{Value History, ,Value History}), after printing one out. |
c906108c SS |
8541 | |
8542 | Another way to create an artificial array is to use a cast. | |
8543 | This re-interprets a value as if it were an array. | |
8544 | The value need not be in memory: | |
474c8240 | 8545 | @smallexample |
c906108c SS |
8546 | (@value{GDBP}) p/x (short[2])0x12345678 |
8547 | $1 = @{0x1234, 0x5678@} | |
474c8240 | 8548 | @end smallexample |
c906108c SS |
8549 | |
8550 | As a convenience, if you leave the array length out (as in | |
c3f6f71d | 8551 | @samp{(@var{type}[])@var{value}}) @value{GDBN} calculates the size to fill |
c906108c | 8552 | the value (as @samp{sizeof(@var{value})/sizeof(@var{type})}: |
474c8240 | 8553 | @smallexample |
c906108c SS |
8554 | (@value{GDBP}) p/x (short[])0x12345678 |
8555 | $2 = @{0x1234, 0x5678@} | |
474c8240 | 8556 | @end smallexample |
c906108c SS |
8557 | |
8558 | Sometimes the artificial array mechanism is not quite enough; in | |
8559 | moderately complex data structures, the elements of interest may not | |
8560 | actually be adjacent---for example, if you are interested in the values | |
8561 | of pointers in an array. One useful work-around in this situation is | |
8562 | to use a convenience variable (@pxref{Convenience Vars, ,Convenience | |
79a6e687 | 8563 | Variables}) as a counter in an expression that prints the first |
c906108c SS |
8564 | interesting value, and then repeat that expression via @key{RET}. For |
8565 | instance, suppose you have an array @code{dtab} of pointers to | |
8566 | structures, and you are interested in the values of a field @code{fv} | |
8567 | in each structure. Here is an example of what you might type: | |
8568 | ||
474c8240 | 8569 | @smallexample |
c906108c SS |
8570 | set $i = 0 |
8571 | p dtab[$i++]->fv | |
8572 | @key{RET} | |
8573 | @key{RET} | |
8574 | @dots{} | |
474c8240 | 8575 | @end smallexample |
c906108c | 8576 | |
6d2ebf8b | 8577 | @node Output Formats |
79a6e687 | 8578 | @section Output Formats |
c906108c SS |
8579 | |
8580 | @cindex formatted output | |
8581 | @cindex output formats | |
8582 | By default, @value{GDBN} prints a value according to its data type. Sometimes | |
8583 | this is not what you want. For example, you might want to print a number | |
8584 | in hex, or a pointer in decimal. Or you might want to view data in memory | |
8585 | at a certain address as a character string or as an instruction. To do | |
8586 | these things, specify an @dfn{output format} when you print a value. | |
8587 | ||
8588 | The simplest use of output formats is to say how to print a value | |
8589 | already computed. This is done by starting the arguments of the | |
8590 | @code{print} command with a slash and a format letter. The format | |
8591 | letters supported are: | |
8592 | ||
8593 | @table @code | |
8594 | @item x | |
8595 | Regard the bits of the value as an integer, and print the integer in | |
8596 | hexadecimal. | |
8597 | ||
8598 | @item d | |
8599 | Print as integer in signed decimal. | |
8600 | ||
8601 | @item u | |
8602 | Print as integer in unsigned decimal. | |
8603 | ||
8604 | @item o | |
8605 | Print as integer in octal. | |
8606 | ||
8607 | @item t | |
8608 | Print as integer in binary. The letter @samp{t} stands for ``two''. | |
8609 | @footnote{@samp{b} cannot be used because these format letters are also | |
8610 | used with the @code{x} command, where @samp{b} stands for ``byte''; | |
79a6e687 | 8611 | see @ref{Memory,,Examining Memory}.} |
c906108c SS |
8612 | |
8613 | @item a | |
8614 | @cindex unknown address, locating | |
3d67e040 | 8615 | @cindex locate address |
c906108c SS |
8616 | Print as an address, both absolute in hexadecimal and as an offset from |
8617 | the nearest preceding symbol. You can use this format used to discover | |
8618 | where (in what function) an unknown address is located: | |
8619 | ||
474c8240 | 8620 | @smallexample |
c906108c SS |
8621 | (@value{GDBP}) p/a 0x54320 |
8622 | $3 = 0x54320 <_initialize_vx+396> | |
474c8240 | 8623 | @end smallexample |
c906108c | 8624 | |
3d67e040 EZ |
8625 | @noindent |
8626 | The command @code{info symbol 0x54320} yields similar results. | |
8627 | @xref{Symbols, info symbol}. | |
8628 | ||
c906108c | 8629 | @item c |
51274035 EZ |
8630 | Regard as an integer and print it as a character constant. This |
8631 | prints both the numerical value and its character representation. The | |
8632 | character representation is replaced with the octal escape @samp{\nnn} | |
8633 | for characters outside the 7-bit @sc{ascii} range. | |
c906108c | 8634 | |
ea37ba09 DJ |
8635 | Without this format, @value{GDBN} displays @code{char}, |
8636 | @w{@code{unsigned char}}, and @w{@code{signed char}} data as character | |
8637 | constants. Single-byte members of vectors are displayed as integer | |
8638 | data. | |
8639 | ||
c906108c SS |
8640 | @item f |
8641 | Regard the bits of the value as a floating point number and print | |
8642 | using typical floating point syntax. | |
ea37ba09 DJ |
8643 | |
8644 | @item s | |
8645 | @cindex printing strings | |
8646 | @cindex printing byte arrays | |
8647 | Regard as a string, if possible. With this format, pointers to single-byte | |
8648 | data are displayed as null-terminated strings and arrays of single-byte data | |
8649 | are displayed as fixed-length strings. Other values are displayed in their | |
8650 | natural types. | |
8651 | ||
8652 | Without this format, @value{GDBN} displays pointers to and arrays of | |
8653 | @code{char}, @w{@code{unsigned char}}, and @w{@code{signed char}} as | |
8654 | strings. Single-byte members of a vector are displayed as an integer | |
8655 | array. | |
a6bac58e | 8656 | |
6fbe845e AB |
8657 | @item z |
8658 | Like @samp{x} formatting, the value is treated as an integer and | |
8659 | printed as hexadecimal, but leading zeros are printed to pad the value | |
8660 | to the size of the integer type. | |
8661 | ||
a6bac58e TT |
8662 | @item r |
8663 | @cindex raw printing | |
8664 | Print using the @samp{raw} formatting. By default, @value{GDBN} will | |
78e2826b TT |
8665 | use a Python-based pretty-printer, if one is available (@pxref{Pretty |
8666 | Printing}). This typically results in a higher-level display of the | |
8667 | value's contents. The @samp{r} format bypasses any Python | |
8668 | pretty-printer which might exist. | |
c906108c SS |
8669 | @end table |
8670 | ||
8671 | For example, to print the program counter in hex (@pxref{Registers}), type | |
8672 | ||
474c8240 | 8673 | @smallexample |
c906108c | 8674 | p/x $pc |
474c8240 | 8675 | @end smallexample |
c906108c SS |
8676 | |
8677 | @noindent | |
8678 | Note that no space is required before the slash; this is because command | |
8679 | names in @value{GDBN} cannot contain a slash. | |
8680 | ||
8681 | To reprint the last value in the value history with a different format, | |
8682 | you can use the @code{print} command with just a format and no | |
8683 | expression. For example, @samp{p/x} reprints the last value in hex. | |
8684 | ||
6d2ebf8b | 8685 | @node Memory |
79a6e687 | 8686 | @section Examining Memory |
c906108c SS |
8687 | |
8688 | You can use the command @code{x} (for ``examine'') to examine memory in | |
8689 | any of several formats, independently of your program's data types. | |
8690 | ||
8691 | @cindex examining memory | |
8692 | @table @code | |
41afff9a | 8693 | @kindex x @r{(examine memory)} |
c906108c SS |
8694 | @item x/@var{nfu} @var{addr} |
8695 | @itemx x @var{addr} | |
8696 | @itemx x | |
8697 | Use the @code{x} command to examine memory. | |
8698 | @end table | |
8699 | ||
8700 | @var{n}, @var{f}, and @var{u} are all optional parameters that specify how | |
8701 | much memory to display and how to format it; @var{addr} is an | |
8702 | expression giving the address where you want to start displaying memory. | |
8703 | If you use defaults for @var{nfu}, you need not type the slash @samp{/}. | |
8704 | Several commands set convenient defaults for @var{addr}. | |
8705 | ||
8706 | @table @r | |
8707 | @item @var{n}, the repeat count | |
8708 | The repeat count is a decimal integer; the default is 1. It specifies | |
8709 | how much memory (counting by units @var{u}) to display. | |
8710 | @c This really is **decimal**; unaffected by 'set radix' as of GDB | |
8711 | @c 4.1.2. | |
8712 | ||
8713 | @item @var{f}, the display format | |
51274035 EZ |
8714 | The display format is one of the formats used by @code{print} |
8715 | (@samp{x}, @samp{d}, @samp{u}, @samp{o}, @samp{t}, @samp{a}, @samp{c}, | |
ea37ba09 DJ |
8716 | @samp{f}, @samp{s}), and in addition @samp{i} (for machine instructions). |
8717 | The default is @samp{x} (hexadecimal) initially. The default changes | |
8718 | each time you use either @code{x} or @code{print}. | |
c906108c SS |
8719 | |
8720 | @item @var{u}, the unit size | |
8721 | The unit size is any of | |
8722 | ||
8723 | @table @code | |
8724 | @item b | |
8725 | Bytes. | |
8726 | @item h | |
8727 | Halfwords (two bytes). | |
8728 | @item w | |
8729 | Words (four bytes). This is the initial default. | |
8730 | @item g | |
8731 | Giant words (eight bytes). | |
8732 | @end table | |
8733 | ||
8734 | Each time you specify a unit size with @code{x}, that size becomes the | |
9a22f0d0 PM |
8735 | default unit the next time you use @code{x}. For the @samp{i} format, |
8736 | the unit size is ignored and is normally not written. For the @samp{s} format, | |
8737 | the unit size defaults to @samp{b}, unless it is explicitly given. | |
8738 | Use @kbd{x /hs} to display 16-bit char strings and @kbd{x /ws} to display | |
8739 | 32-bit strings. The next use of @kbd{x /s} will again display 8-bit strings. | |
8740 | Note that the results depend on the programming language of the | |
8741 | current compilation unit. If the language is C, the @samp{s} | |
8742 | modifier will use the UTF-16 encoding while @samp{w} will use | |
8743 | UTF-32. The encoding is set by the programming language and cannot | |
8744 | be altered. | |
c906108c SS |
8745 | |
8746 | @item @var{addr}, starting display address | |
8747 | @var{addr} is the address where you want @value{GDBN} to begin displaying | |
8748 | memory. The expression need not have a pointer value (though it may); | |
8749 | it is always interpreted as an integer address of a byte of memory. | |
8750 | @xref{Expressions, ,Expressions}, for more information on expressions. The default for | |
8751 | @var{addr} is usually just after the last address examined---but several | |
8752 | other commands also set the default address: @code{info breakpoints} (to | |
8753 | the address of the last breakpoint listed), @code{info line} (to the | |
8754 | starting address of a line), and @code{print} (if you use it to display | |
8755 | a value from memory). | |
8756 | @end table | |
8757 | ||
8758 | For example, @samp{x/3uh 0x54320} is a request to display three halfwords | |
8759 | (@code{h}) of memory, formatted as unsigned decimal integers (@samp{u}), | |
8760 | starting at address @code{0x54320}. @samp{x/4xw $sp} prints the four | |
8761 | words (@samp{w}) of memory above the stack pointer (here, @samp{$sp}; | |
d4f3574e | 8762 | @pxref{Registers, ,Registers}) in hexadecimal (@samp{x}). |
c906108c SS |
8763 | |
8764 | Since the letters indicating unit sizes are all distinct from the | |
8765 | letters specifying output formats, you do not have to remember whether | |
8766 | unit size or format comes first; either order works. The output | |
8767 | specifications @samp{4xw} and @samp{4wx} mean exactly the same thing. | |
8768 | (However, the count @var{n} must come first; @samp{wx4} does not work.) | |
8769 | ||
8770 | Even though the unit size @var{u} is ignored for the formats @samp{s} | |
8771 | and @samp{i}, you might still want to use a count @var{n}; for example, | |
8772 | @samp{3i} specifies that you want to see three machine instructions, | |
a4642986 MR |
8773 | including any operands. For convenience, especially when used with |
8774 | the @code{display} command, the @samp{i} format also prints branch delay | |
8775 | slot instructions, if any, beyond the count specified, which immediately | |
8776 | follow the last instruction that is within the count. The command | |
8777 | @code{disassemble} gives an alternative way of inspecting machine | |
8778 | instructions; see @ref{Machine Code,,Source and Machine Code}. | |
c906108c SS |
8779 | |
8780 | All the defaults for the arguments to @code{x} are designed to make it | |
8781 | easy to continue scanning memory with minimal specifications each time | |
8782 | you use @code{x}. For example, after you have inspected three machine | |
8783 | instructions with @samp{x/3i @var{addr}}, you can inspect the next seven | |
8784 | with just @samp{x/7}. If you use @key{RET} to repeat the @code{x} command, | |
8785 | the repeat count @var{n} is used again; the other arguments default as | |
8786 | for successive uses of @code{x}. | |
8787 | ||
2b28d209 PP |
8788 | When examining machine instructions, the instruction at current program |
8789 | counter is shown with a @code{=>} marker. For example: | |
8790 | ||
8791 | @smallexample | |
8792 | (@value{GDBP}) x/5i $pc-6 | |
8793 | 0x804837f <main+11>: mov %esp,%ebp | |
8794 | 0x8048381 <main+13>: push %ecx | |
8795 | 0x8048382 <main+14>: sub $0x4,%esp | |
8796 | => 0x8048385 <main+17>: movl $0x8048460,(%esp) | |
8797 | 0x804838c <main+24>: call 0x80482d4 <puts@@plt> | |
8798 | @end smallexample | |
8799 | ||
c906108c SS |
8800 | @cindex @code{$_}, @code{$__}, and value history |
8801 | The addresses and contents printed by the @code{x} command are not saved | |
8802 | in the value history because there is often too much of them and they | |
8803 | would get in the way. Instead, @value{GDBN} makes these values available for | |
8804 | subsequent use in expressions as values of the convenience variables | |
8805 | @code{$_} and @code{$__}. After an @code{x} command, the last address | |
8806 | examined is available for use in expressions in the convenience variable | |
8807 | @code{$_}. The contents of that address, as examined, are available in | |
8808 | the convenience variable @code{$__}. | |
8809 | ||
8810 | If the @code{x} command has a repeat count, the address and contents saved | |
8811 | are from the last memory unit printed; this is not the same as the last | |
8812 | address printed if several units were printed on the last line of output. | |
8813 | ||
09d4efe1 | 8814 | @cindex remote memory comparison |
936d2992 | 8815 | @cindex target memory comparison |
09d4efe1 | 8816 | @cindex verify remote memory image |
936d2992 | 8817 | @cindex verify target memory image |
09d4efe1 | 8818 | When you are debugging a program running on a remote target machine |
936d2992 PA |
8819 | (@pxref{Remote Debugging}), you may wish to verify the program's image |
8820 | in the remote machine's memory against the executable file you | |
8821 | downloaded to the target. Or, on any target, you may want to check | |
8822 | whether the program has corrupted its own read-only sections. The | |
8823 | @code{compare-sections} command is provided for such situations. | |
09d4efe1 EZ |
8824 | |
8825 | @table @code | |
8826 | @kindex compare-sections | |
95cf3b38 | 8827 | @item compare-sections @r{[}@var{section-name}@r{|}@code{-r}@r{]} |
09d4efe1 EZ |
8828 | Compare the data of a loadable section @var{section-name} in the |
8829 | executable file of the program being debugged with the same section in | |
936d2992 | 8830 | the target machine's memory, and report any mismatches. With no |
95cf3b38 | 8831 | arguments, compares all loadable sections. With an argument of |
936d2992 PA |
8832 | @code{-r}, compares all loadable read-only sections. |
8833 | ||
8834 | Note: for remote targets, this command can be accelerated if the | |
8835 | target supports computing the CRC checksum of a block of memory | |
8836 | (@pxref{qCRC packet}). | |
09d4efe1 EZ |
8837 | @end table |
8838 | ||
6d2ebf8b | 8839 | @node Auto Display |
79a6e687 | 8840 | @section Automatic Display |
c906108c SS |
8841 | @cindex automatic display |
8842 | @cindex display of expressions | |
8843 | ||
8844 | If you find that you want to print the value of an expression frequently | |
8845 | (to see how it changes), you might want to add it to the @dfn{automatic | |
8846 | display list} so that @value{GDBN} prints its value each time your program stops. | |
8847 | Each expression added to the list is given a number to identify it; | |
8848 | to remove an expression from the list, you specify that number. | |
8849 | The automatic display looks like this: | |
8850 | ||
474c8240 | 8851 | @smallexample |
c906108c SS |
8852 | 2: foo = 38 |
8853 | 3: bar[5] = (struct hack *) 0x3804 | |
474c8240 | 8854 | @end smallexample |
c906108c SS |
8855 | |
8856 | @noindent | |
8857 | This display shows item numbers, expressions and their current values. As with | |
8858 | displays you request manually using @code{x} or @code{print}, you can | |
8859 | specify the output format you prefer; in fact, @code{display} decides | |
ea37ba09 DJ |
8860 | whether to use @code{print} or @code{x} depending your format |
8861 | specification---it uses @code{x} if you specify either the @samp{i} | |
8862 | or @samp{s} format, or a unit size; otherwise it uses @code{print}. | |
c906108c SS |
8863 | |
8864 | @table @code | |
8865 | @kindex display | |
d4f3574e SS |
8866 | @item display @var{expr} |
8867 | Add the expression @var{expr} to the list of expressions to display | |
c906108c SS |
8868 | each time your program stops. @xref{Expressions, ,Expressions}. |
8869 | ||
8870 | @code{display} does not repeat if you press @key{RET} again after using it. | |
8871 | ||
d4f3574e | 8872 | @item display/@var{fmt} @var{expr} |
c906108c | 8873 | For @var{fmt} specifying only a display format and not a size or |
d4f3574e | 8874 | count, add the expression @var{expr} to the auto-display list but |
c906108c | 8875 | arrange to display it each time in the specified format @var{fmt}. |
79a6e687 | 8876 | @xref{Output Formats,,Output Formats}. |
c906108c SS |
8877 | |
8878 | @item display/@var{fmt} @var{addr} | |
8879 | For @var{fmt} @samp{i} or @samp{s}, or including a unit-size or a | |
8880 | number of units, add the expression @var{addr} as a memory address to | |
8881 | be examined each time your program stops. Examining means in effect | |
79a6e687 | 8882 | doing @samp{x/@var{fmt} @var{addr}}. @xref{Memory, ,Examining Memory}. |
c906108c SS |
8883 | @end table |
8884 | ||
8885 | For example, @samp{display/i $pc} can be helpful, to see the machine | |
8886 | instruction about to be executed each time execution stops (@samp{$pc} | |
d4f3574e | 8887 | is a common name for the program counter; @pxref{Registers, ,Registers}). |
c906108c SS |
8888 | |
8889 | @table @code | |
8890 | @kindex delete display | |
8891 | @kindex undisplay | |
8892 | @item undisplay @var{dnums}@dots{} | |
8893 | @itemx delete display @var{dnums}@dots{} | |
c9174737 PA |
8894 | Remove items from the list of expressions to display. Specify the |
8895 | numbers of the displays that you want affected with the command | |
8896 | argument @var{dnums}. It can be a single display number, one of the | |
8897 | numbers shown in the first field of the @samp{info display} display; | |
8898 | or it could be a range of display numbers, as in @code{2-4}. | |
c906108c SS |
8899 | |
8900 | @code{undisplay} does not repeat if you press @key{RET} after using it. | |
8901 | (Otherwise you would just get the error @samp{No display number @dots{}}.) | |
8902 | ||
8903 | @kindex disable display | |
8904 | @item disable display @var{dnums}@dots{} | |
8905 | Disable the display of item numbers @var{dnums}. A disabled display | |
8906 | item is not printed automatically, but is not forgotten. It may be | |
c9174737 PA |
8907 | enabled again later. Specify the numbers of the displays that you |
8908 | want affected with the command argument @var{dnums}. It can be a | |
8909 | single display number, one of the numbers shown in the first field of | |
8910 | the @samp{info display} display; or it could be a range of display | |
8911 | numbers, as in @code{2-4}. | |
c906108c SS |
8912 | |
8913 | @kindex enable display | |
8914 | @item enable display @var{dnums}@dots{} | |
8915 | Enable display of item numbers @var{dnums}. It becomes effective once | |
8916 | again in auto display of its expression, until you specify otherwise. | |
c9174737 PA |
8917 | Specify the numbers of the displays that you want affected with the |
8918 | command argument @var{dnums}. It can be a single display number, one | |
8919 | of the numbers shown in the first field of the @samp{info display} | |
8920 | display; or it could be a range of display numbers, as in @code{2-4}. | |
c906108c SS |
8921 | |
8922 | @item display | |
8923 | Display the current values of the expressions on the list, just as is | |
8924 | done when your program stops. | |
8925 | ||
8926 | @kindex info display | |
8927 | @item info display | |
8928 | Print the list of expressions previously set up to display | |
8929 | automatically, each one with its item number, but without showing the | |
8930 | values. This includes disabled expressions, which are marked as such. | |
8931 | It also includes expressions which would not be displayed right now | |
8932 | because they refer to automatic variables not currently available. | |
8933 | @end table | |
8934 | ||
15387254 | 8935 | @cindex display disabled out of scope |
c906108c SS |
8936 | If a display expression refers to local variables, then it does not make |
8937 | sense outside the lexical context for which it was set up. Such an | |
8938 | expression is disabled when execution enters a context where one of its | |
8939 | variables is not defined. For example, if you give the command | |
8940 | @code{display last_char} while inside a function with an argument | |
8941 | @code{last_char}, @value{GDBN} displays this argument while your program | |
8942 | continues to stop inside that function. When it stops elsewhere---where | |
8943 | there is no variable @code{last_char}---the display is disabled | |
8944 | automatically. The next time your program stops where @code{last_char} | |
8945 | is meaningful, you can enable the display expression once again. | |
8946 | ||
6d2ebf8b | 8947 | @node Print Settings |
79a6e687 | 8948 | @section Print Settings |
c906108c SS |
8949 | |
8950 | @cindex format options | |
8951 | @cindex print settings | |
8952 | @value{GDBN} provides the following ways to control how arrays, structures, | |
8953 | and symbols are printed. | |
8954 | ||
8955 | @noindent | |
8956 | These settings are useful for debugging programs in any language: | |
8957 | ||
8958 | @table @code | |
4644b6e3 | 8959 | @kindex set print |
c906108c SS |
8960 | @item set print address |
8961 | @itemx set print address on | |
4644b6e3 | 8962 | @cindex print/don't print memory addresses |
c906108c SS |
8963 | @value{GDBN} prints memory addresses showing the location of stack |
8964 | traces, structure values, pointer values, breakpoints, and so forth, | |
8965 | even when it also displays the contents of those addresses. The default | |
8966 | is @code{on}. For example, this is what a stack frame display looks like with | |
8967 | @code{set print address on}: | |
8968 | ||
8969 | @smallexample | |
8970 | @group | |
8971 | (@value{GDBP}) f | |
8972 | #0 set_quotes (lq=0x34c78 "<<", rq=0x34c88 ">>") | |
8973 | at input.c:530 | |
8974 | 530 if (lquote != def_lquote) | |
8975 | @end group | |
8976 | @end smallexample | |
8977 | ||
8978 | @item set print address off | |
8979 | Do not print addresses when displaying their contents. For example, | |
8980 | this is the same stack frame displayed with @code{set print address off}: | |
8981 | ||
8982 | @smallexample | |
8983 | @group | |
8984 | (@value{GDBP}) set print addr off | |
8985 | (@value{GDBP}) f | |
8986 | #0 set_quotes (lq="<<", rq=">>") at input.c:530 | |
8987 | 530 if (lquote != def_lquote) | |
8988 | @end group | |
8989 | @end smallexample | |
8990 | ||
8991 | You can use @samp{set print address off} to eliminate all machine | |
8992 | dependent displays from the @value{GDBN} interface. For example, with | |
8993 | @code{print address off}, you should get the same text for backtraces on | |
8994 | all machines---whether or not they involve pointer arguments. | |
8995 | ||
4644b6e3 | 8996 | @kindex show print |
c906108c SS |
8997 | @item show print address |
8998 | Show whether or not addresses are to be printed. | |
8999 | @end table | |
9000 | ||
9001 | When @value{GDBN} prints a symbolic address, it normally prints the | |
9002 | closest earlier symbol plus an offset. If that symbol does not uniquely | |
9003 | identify the address (for example, it is a name whose scope is a single | |
9004 | source file), you may need to clarify. One way to do this is with | |
9005 | @code{info line}, for example @samp{info line *0x4537}. Alternately, | |
9006 | you can set @value{GDBN} to print the source file and line number when | |
9007 | it prints a symbolic address: | |
9008 | ||
9009 | @table @code | |
c906108c | 9010 | @item set print symbol-filename on |
9c16f35a EZ |
9011 | @cindex source file and line of a symbol |
9012 | @cindex symbol, source file and line | |
c906108c SS |
9013 | Tell @value{GDBN} to print the source file name and line number of a |
9014 | symbol in the symbolic form of an address. | |
9015 | ||
9016 | @item set print symbol-filename off | |
9017 | Do not print source file name and line number of a symbol. This is the | |
9018 | default. | |
9019 | ||
c906108c SS |
9020 | @item show print symbol-filename |
9021 | Show whether or not @value{GDBN} will print the source file name and | |
9022 | line number of a symbol in the symbolic form of an address. | |
9023 | @end table | |
9024 | ||
9025 | Another situation where it is helpful to show symbol filenames and line | |
9026 | numbers is when disassembling code; @value{GDBN} shows you the line | |
9027 | number and source file that corresponds to each instruction. | |
9028 | ||
9029 | Also, you may wish to see the symbolic form only if the address being | |
9030 | printed is reasonably close to the closest earlier symbol: | |
9031 | ||
9032 | @table @code | |
c906108c | 9033 | @item set print max-symbolic-offset @var{max-offset} |
f81d1120 | 9034 | @itemx set print max-symbolic-offset unlimited |
4644b6e3 | 9035 | @cindex maximum value for offset of closest symbol |
c906108c SS |
9036 | Tell @value{GDBN} to only display the symbolic form of an address if the |
9037 | offset between the closest earlier symbol and the address is less than | |
f81d1120 PA |
9038 | @var{max-offset}. The default is @code{unlimited}, which tells @value{GDBN} |
9039 | to always print the symbolic form of an address if any symbol precedes | |
9040 | it. Zero is equivalent to @code{unlimited}. | |
c906108c | 9041 | |
c906108c SS |
9042 | @item show print max-symbolic-offset |
9043 | Ask how large the maximum offset is that @value{GDBN} prints in a | |
9044 | symbolic address. | |
9045 | @end table | |
9046 | ||
9047 | @cindex wild pointer, interpreting | |
9048 | @cindex pointer, finding referent | |
9049 | If you have a pointer and you are not sure where it points, try | |
9050 | @samp{set print symbol-filename on}. Then you can determine the name | |
9051 | and source file location of the variable where it points, using | |
9052 | @samp{p/a @var{pointer}}. This interprets the address in symbolic form. | |
9053 | For example, here @value{GDBN} shows that a variable @code{ptt} points | |
9054 | at another variable @code{t}, defined in @file{hi2.c}: | |
9055 | ||
474c8240 | 9056 | @smallexample |
c906108c SS |
9057 | (@value{GDBP}) set print symbol-filename on |
9058 | (@value{GDBP}) p/a ptt | |
9059 | $4 = 0xe008 <t in hi2.c> | |
474c8240 | 9060 | @end smallexample |
c906108c SS |
9061 | |
9062 | @quotation | |
9063 | @emph{Warning:} For pointers that point to a local variable, @samp{p/a} | |
9064 | does not show the symbol name and filename of the referent, even with | |
9065 | the appropriate @code{set print} options turned on. | |
9066 | @end quotation | |
9067 | ||
9cb709b6 TT |
9068 | You can also enable @samp{/a}-like formatting all the time using |
9069 | @samp{set print symbol on}: | |
9070 | ||
9071 | @table @code | |
9072 | @item set print symbol on | |
9073 | Tell @value{GDBN} to print the symbol corresponding to an address, if | |
9074 | one exists. | |
9075 | ||
9076 | @item set print symbol off | |
9077 | Tell @value{GDBN} not to print the symbol corresponding to an | |
9078 | address. In this mode, @value{GDBN} will still print the symbol | |
9079 | corresponding to pointers to functions. This is the default. | |
9080 | ||
9081 | @item show print symbol | |
9082 | Show whether @value{GDBN} will display the symbol corresponding to an | |
9083 | address. | |
9084 | @end table | |
9085 | ||
c906108c SS |
9086 | Other settings control how different kinds of objects are printed: |
9087 | ||
9088 | @table @code | |
c906108c SS |
9089 | @item set print array |
9090 | @itemx set print array on | |
4644b6e3 | 9091 | @cindex pretty print arrays |
c906108c SS |
9092 | Pretty print arrays. This format is more convenient to read, |
9093 | but uses more space. The default is off. | |
9094 | ||
9095 | @item set print array off | |
9096 | Return to compressed format for arrays. | |
9097 | ||
c906108c SS |
9098 | @item show print array |
9099 | Show whether compressed or pretty format is selected for displaying | |
9100 | arrays. | |
9101 | ||
3c9c013a JB |
9102 | @cindex print array indexes |
9103 | @item set print array-indexes | |
9104 | @itemx set print array-indexes on | |
9105 | Print the index of each element when displaying arrays. May be more | |
9106 | convenient to locate a given element in the array or quickly find the | |
9107 | index of a given element in that printed array. The default is off. | |
9108 | ||
9109 | @item set print array-indexes off | |
9110 | Stop printing element indexes when displaying arrays. | |
9111 | ||
9112 | @item show print array-indexes | |
9113 | Show whether the index of each element is printed when displaying | |
9114 | arrays. | |
9115 | ||
c906108c | 9116 | @item set print elements @var{number-of-elements} |
f81d1120 | 9117 | @itemx set print elements unlimited |
4644b6e3 | 9118 | @cindex number of array elements to print |
9c16f35a | 9119 | @cindex limit on number of printed array elements |
c906108c SS |
9120 | Set a limit on how many elements of an array @value{GDBN} will print. |
9121 | If @value{GDBN} is printing a large array, it stops printing after it has | |
9122 | printed the number of elements set by the @code{set print elements} command. | |
9123 | This limit also applies to the display of strings. | |
d4f3574e | 9124 | When @value{GDBN} starts, this limit is set to 200. |
f81d1120 PA |
9125 | Setting @var{number-of-elements} to @code{unlimited} or zero means |
9126 | that the number of elements to print is unlimited. | |
c906108c | 9127 | |
c906108c SS |
9128 | @item show print elements |
9129 | Display the number of elements of a large array that @value{GDBN} will print. | |
9130 | If the number is 0, then the printing is unlimited. | |
9131 | ||
b4740add | 9132 | @item set print frame-arguments @var{value} |
a0381d3a | 9133 | @kindex set print frame-arguments |
b4740add JB |
9134 | @cindex printing frame argument values |
9135 | @cindex print all frame argument values | |
9136 | @cindex print frame argument values for scalars only | |
9137 | @cindex do not print frame argument values | |
9138 | This command allows to control how the values of arguments are printed | |
9139 | when the debugger prints a frame (@pxref{Frames}). The possible | |
9140 | values are: | |
9141 | ||
9142 | @table @code | |
9143 | @item all | |
4f5376b2 | 9144 | The values of all arguments are printed. |
b4740add JB |
9145 | |
9146 | @item scalars | |
9147 | Print the value of an argument only if it is a scalar. The value of more | |
9148 | complex arguments such as arrays, structures, unions, etc, is replaced | |
4f5376b2 JB |
9149 | by @code{@dots{}}. This is the default. Here is an example where |
9150 | only scalar arguments are shown: | |
b4740add JB |
9151 | |
9152 | @smallexample | |
9153 | #1 0x08048361 in call_me (i=3, s=@dots{}, ss=0xbf8d508c, u=@dots{}, e=green) | |
9154 | at frame-args.c:23 | |
9155 | @end smallexample | |
9156 | ||
9157 | @item none | |
9158 | None of the argument values are printed. Instead, the value of each argument | |
9159 | is replaced by @code{@dots{}}. In this case, the example above now becomes: | |
9160 | ||
9161 | @smallexample | |
9162 | #1 0x08048361 in call_me (i=@dots{}, s=@dots{}, ss=@dots{}, u=@dots{}, e=@dots{}) | |
9163 | at frame-args.c:23 | |
9164 | @end smallexample | |
9165 | @end table | |
9166 | ||
4f5376b2 JB |
9167 | By default, only scalar arguments are printed. This command can be used |
9168 | to configure the debugger to print the value of all arguments, regardless | |
9169 | of their type. However, it is often advantageous to not print the value | |
9170 | of more complex parameters. For instance, it reduces the amount of | |
9171 | information printed in each frame, making the backtrace more readable. | |
9172 | Also, it improves performance when displaying Ada frames, because | |
9173 | the computation of large arguments can sometimes be CPU-intensive, | |
9174 | especially in large applications. Setting @code{print frame-arguments} | |
9175 | to @code{scalars} (the default) or @code{none} avoids this computation, | |
9176 | thus speeding up the display of each Ada frame. | |
b4740add JB |
9177 | |
9178 | @item show print frame-arguments | |
9179 | Show how the value of arguments should be displayed when printing a frame. | |
9180 | ||
e7045703 DE |
9181 | @item set print raw frame-arguments on |
9182 | Print frame arguments in raw, non pretty-printed, form. | |
9183 | ||
9184 | @item set print raw frame-arguments off | |
9185 | Print frame arguments in pretty-printed form, if there is a pretty-printer | |
9186 | for the value (@pxref{Pretty Printing}), | |
9187 | otherwise print the value in raw form. | |
9188 | This is the default. | |
9189 | ||
9190 | @item show print raw frame-arguments | |
9191 | Show whether to print frame arguments in raw form. | |
9192 | ||
36b11add | 9193 | @anchor{set print entry-values} |
e18b2753 JK |
9194 | @item set print entry-values @var{value} |
9195 | @kindex set print entry-values | |
9196 | Set printing of frame argument values at function entry. In some cases | |
9197 | @value{GDBN} can determine the value of function argument which was passed by | |
9198 | the function caller, even if the value was modified inside the called function | |
9199 | and therefore is different. With optimized code, the current value could be | |
9200 | unavailable, but the entry value may still be known. | |
9201 | ||
9202 | The default value is @code{default} (see below for its description). Older | |
9203 | @value{GDBN} behaved as with the setting @code{no}. Compilers not supporting | |
9204 | this feature will behave in the @code{default} setting the same way as with the | |
9205 | @code{no} setting. | |
9206 | ||
9207 | This functionality is currently supported only by DWARF 2 debugging format and | |
9208 | the compiler has to produce @samp{DW_TAG_GNU_call_site} tags. With | |
9209 | @value{NGCC}, you need to specify @option{-O -g} during compilation, to get | |
9210 | this information. | |
9211 | ||
9212 | The @var{value} parameter can be one of the following: | |
9213 | ||
9214 | @table @code | |
9215 | @item no | |
9216 | Print only actual parameter values, never print values from function entry | |
9217 | point. | |
9218 | @smallexample | |
9219 | #0 equal (val=5) | |
9220 | #0 different (val=6) | |
9221 | #0 lost (val=<optimized out>) | |
9222 | #0 born (val=10) | |
9223 | #0 invalid (val=<optimized out>) | |
9224 | @end smallexample | |
9225 | ||
9226 | @item only | |
9227 | Print only parameter values from function entry point. The actual parameter | |
9228 | values are never printed. | |
9229 | @smallexample | |
9230 | #0 equal (val@@entry=5) | |
9231 | #0 different (val@@entry=5) | |
9232 | #0 lost (val@@entry=5) | |
9233 | #0 born (val@@entry=<optimized out>) | |
9234 | #0 invalid (val@@entry=<optimized out>) | |
9235 | @end smallexample | |
9236 | ||
9237 | @item preferred | |
9238 | Print only parameter values from function entry point. If value from function | |
9239 | entry point is not known while the actual value is known, print the actual | |
9240 | value for such parameter. | |
9241 | @smallexample | |
9242 | #0 equal (val@@entry=5) | |
9243 | #0 different (val@@entry=5) | |
9244 | #0 lost (val@@entry=5) | |
9245 | #0 born (val=10) | |
9246 | #0 invalid (val@@entry=<optimized out>) | |
9247 | @end smallexample | |
9248 | ||
9249 | @item if-needed | |
9250 | Print actual parameter values. If actual parameter value is not known while | |
9251 | value from function entry point is known, print the entry point value for such | |
9252 | parameter. | |
9253 | @smallexample | |
9254 | #0 equal (val=5) | |
9255 | #0 different (val=6) | |
9256 | #0 lost (val@@entry=5) | |
9257 | #0 born (val=10) | |
9258 | #0 invalid (val=<optimized out>) | |
9259 | @end smallexample | |
9260 | ||
9261 | @item both | |
9262 | Always print both the actual parameter value and its value from function entry | |
9263 | point, even if values of one or both are not available due to compiler | |
9264 | optimizations. | |
9265 | @smallexample | |
9266 | #0 equal (val=5, val@@entry=5) | |
9267 | #0 different (val=6, val@@entry=5) | |
9268 | #0 lost (val=<optimized out>, val@@entry=5) | |
9269 | #0 born (val=10, val@@entry=<optimized out>) | |
9270 | #0 invalid (val=<optimized out>, val@@entry=<optimized out>) | |
9271 | @end smallexample | |
9272 | ||
9273 | @item compact | |
9274 | Print the actual parameter value if it is known and also its value from | |
9275 | function entry point if it is known. If neither is known, print for the actual | |
9276 | value @code{<optimized out>}. If not in MI mode (@pxref{GDB/MI}) and if both | |
9277 | values are known and identical, print the shortened | |
9278 | @code{param=param@@entry=VALUE} notation. | |
9279 | @smallexample | |
9280 | #0 equal (val=val@@entry=5) | |
9281 | #0 different (val=6, val@@entry=5) | |
9282 | #0 lost (val@@entry=5) | |
9283 | #0 born (val=10) | |
9284 | #0 invalid (val=<optimized out>) | |
9285 | @end smallexample | |
9286 | ||
9287 | @item default | |
9288 | Always print the actual parameter value. Print also its value from function | |
9289 | entry point, but only if it is known. If not in MI mode (@pxref{GDB/MI}) and | |
9290 | if both values are known and identical, print the shortened | |
9291 | @code{param=param@@entry=VALUE} notation. | |
9292 | @smallexample | |
9293 | #0 equal (val=val@@entry=5) | |
9294 | #0 different (val=6, val@@entry=5) | |
9295 | #0 lost (val=<optimized out>, val@@entry=5) | |
9296 | #0 born (val=10) | |
9297 | #0 invalid (val=<optimized out>) | |
9298 | @end smallexample | |
9299 | @end table | |
9300 | ||
9301 | For analysis messages on possible failures of frame argument values at function | |
9302 | entry resolution see @ref{set debug entry-values}. | |
9303 | ||
9304 | @item show print entry-values | |
9305 | Show the method being used for printing of frame argument values at function | |
9306 | entry. | |
9307 | ||
f81d1120 PA |
9308 | @item set print repeats @var{number-of-repeats} |
9309 | @itemx set print repeats unlimited | |
9c16f35a EZ |
9310 | @cindex repeated array elements |
9311 | Set the threshold for suppressing display of repeated array | |
d3e8051b | 9312 | elements. When the number of consecutive identical elements of an |
9c16f35a EZ |
9313 | array exceeds the threshold, @value{GDBN} prints the string |
9314 | @code{"<repeats @var{n} times>"}, where @var{n} is the number of | |
9315 | identical repetitions, instead of displaying the identical elements | |
f81d1120 PA |
9316 | themselves. Setting the threshold to @code{unlimited} or zero will |
9317 | cause all elements to be individually printed. The default threshold | |
9318 | is 10. | |
9c16f35a EZ |
9319 | |
9320 | @item show print repeats | |
9321 | Display the current threshold for printing repeated identical | |
9322 | elements. | |
9323 | ||
c906108c | 9324 | @item set print null-stop |
4644b6e3 | 9325 | @cindex @sc{null} elements in arrays |
c906108c | 9326 | Cause @value{GDBN} to stop printing the characters of an array when the first |
d4f3574e | 9327 | @sc{null} is encountered. This is useful when large arrays actually |
c906108c | 9328 | contain only short strings. |
d4f3574e | 9329 | The default is off. |
c906108c | 9330 | |
9c16f35a EZ |
9331 | @item show print null-stop |
9332 | Show whether @value{GDBN} stops printing an array on the first | |
9333 | @sc{null} character. | |
9334 | ||
c906108c | 9335 | @item set print pretty on |
9c16f35a EZ |
9336 | @cindex print structures in indented form |
9337 | @cindex indentation in structure display | |
5d161b24 | 9338 | Cause @value{GDBN} to print structures in an indented format with one member |
c906108c SS |
9339 | per line, like this: |
9340 | ||
9341 | @smallexample | |
9342 | @group | |
9343 | $1 = @{ | |
9344 | next = 0x0, | |
9345 | flags = @{ | |
9346 | sweet = 1, | |
9347 | sour = 1 | |
9348 | @}, | |
9349 | meat = 0x54 "Pork" | |
9350 | @} | |
9351 | @end group | |
9352 | @end smallexample | |
9353 | ||
9354 | @item set print pretty off | |
9355 | Cause @value{GDBN} to print structures in a compact format, like this: | |
9356 | ||
9357 | @smallexample | |
9358 | @group | |
9359 | $1 = @{next = 0x0, flags = @{sweet = 1, sour = 1@}, \ | |
9360 | meat = 0x54 "Pork"@} | |
9361 | @end group | |
9362 | @end smallexample | |
9363 | ||
9364 | @noindent | |
9365 | This is the default format. | |
9366 | ||
c906108c SS |
9367 | @item show print pretty |
9368 | Show which format @value{GDBN} is using to print structures. | |
9369 | ||
c906108c | 9370 | @item set print sevenbit-strings on |
4644b6e3 EZ |
9371 | @cindex eight-bit characters in strings |
9372 | @cindex octal escapes in strings | |
c906108c SS |
9373 | Print using only seven-bit characters; if this option is set, |
9374 | @value{GDBN} displays any eight-bit characters (in strings or | |
9375 | character values) using the notation @code{\}@var{nnn}. This setting is | |
9376 | best if you are working in English (@sc{ascii}) and you use the | |
9377 | high-order bit of characters as a marker or ``meta'' bit. | |
9378 | ||
9379 | @item set print sevenbit-strings off | |
9380 | Print full eight-bit characters. This allows the use of more | |
9381 | international character sets, and is the default. | |
9382 | ||
c906108c SS |
9383 | @item show print sevenbit-strings |
9384 | Show whether or not @value{GDBN} is printing only seven-bit characters. | |
9385 | ||
c906108c | 9386 | @item set print union on |
4644b6e3 | 9387 | @cindex unions in structures, printing |
9c16f35a EZ |
9388 | Tell @value{GDBN} to print unions which are contained in structures |
9389 | and other unions. This is the default setting. | |
c906108c SS |
9390 | |
9391 | @item set print union off | |
9c16f35a EZ |
9392 | Tell @value{GDBN} not to print unions which are contained in |
9393 | structures and other unions. @value{GDBN} will print @code{"@{...@}"} | |
9394 | instead. | |
c906108c | 9395 | |
c906108c SS |
9396 | @item show print union |
9397 | Ask @value{GDBN} whether or not it will print unions which are contained in | |
9c16f35a | 9398 | structures and other unions. |
c906108c SS |
9399 | |
9400 | For example, given the declarations | |
9401 | ||
9402 | @smallexample | |
9403 | typedef enum @{Tree, Bug@} Species; | |
9404 | typedef enum @{Big_tree, Acorn, Seedling@} Tree_forms; | |
5d161b24 | 9405 | typedef enum @{Caterpillar, Cocoon, Butterfly@} |
c906108c SS |
9406 | Bug_forms; |
9407 | ||
9408 | struct thing @{ | |
9409 | Species it; | |
9410 | union @{ | |
9411 | Tree_forms tree; | |
9412 | Bug_forms bug; | |
9413 | @} form; | |
9414 | @}; | |
9415 | ||
9416 | struct thing foo = @{Tree, @{Acorn@}@}; | |
9417 | @end smallexample | |
9418 | ||
9419 | @noindent | |
9420 | with @code{set print union on} in effect @samp{p foo} would print | |
9421 | ||
9422 | @smallexample | |
9423 | $1 = @{it = Tree, form = @{tree = Acorn, bug = Cocoon@}@} | |
9424 | @end smallexample | |
9425 | ||
9426 | @noindent | |
9427 | and with @code{set print union off} in effect it would print | |
9428 | ||
9429 | @smallexample | |
9430 | $1 = @{it = Tree, form = @{...@}@} | |
9431 | @end smallexample | |
9c16f35a EZ |
9432 | |
9433 | @noindent | |
9434 | @code{set print union} affects programs written in C-like languages | |
9435 | and in Pascal. | |
c906108c SS |
9436 | @end table |
9437 | ||
c906108c SS |
9438 | @need 1000 |
9439 | @noindent | |
b37052ae | 9440 | These settings are of interest when debugging C@t{++} programs: |
c906108c SS |
9441 | |
9442 | @table @code | |
4644b6e3 | 9443 | @cindex demangling C@t{++} names |
c906108c SS |
9444 | @item set print demangle |
9445 | @itemx set print demangle on | |
b37052ae | 9446 | Print C@t{++} names in their source form rather than in the encoded |
c906108c | 9447 | (``mangled'') form passed to the assembler and linker for type-safe |
d4f3574e | 9448 | linkage. The default is on. |
c906108c | 9449 | |
c906108c | 9450 | @item show print demangle |
b37052ae | 9451 | Show whether C@t{++} names are printed in mangled or demangled form. |
c906108c | 9452 | |
c906108c SS |
9453 | @item set print asm-demangle |
9454 | @itemx set print asm-demangle on | |
b37052ae | 9455 | Print C@t{++} names in their source form rather than their mangled form, even |
c906108c SS |
9456 | in assembler code printouts such as instruction disassemblies. |
9457 | The default is off. | |
9458 | ||
c906108c | 9459 | @item show print asm-demangle |
b37052ae | 9460 | Show whether C@t{++} names in assembly listings are printed in mangled |
c906108c SS |
9461 | or demangled form. |
9462 | ||
b37052ae EZ |
9463 | @cindex C@t{++} symbol decoding style |
9464 | @cindex symbol decoding style, C@t{++} | |
a8f24a35 | 9465 | @kindex set demangle-style |
c906108c SS |
9466 | @item set demangle-style @var{style} |
9467 | Choose among several encoding schemes used by different compilers to | |
b37052ae | 9468 | represent C@t{++} names. The choices for @var{style} are currently: |
c906108c SS |
9469 | |
9470 | @table @code | |
9471 | @item auto | |
9472 | Allow @value{GDBN} to choose a decoding style by inspecting your program. | |
891df0ea | 9473 | This is the default. |
c906108c SS |
9474 | |
9475 | @item gnu | |
b37052ae | 9476 | Decode based on the @sc{gnu} C@t{++} compiler (@code{g++}) encoding algorithm. |
c906108c SS |
9477 | |
9478 | @item hp | |
b37052ae | 9479 | Decode based on the HP ANSI C@t{++} (@code{aCC}) encoding algorithm. |
c906108c SS |
9480 | |
9481 | @item lucid | |
b37052ae | 9482 | Decode based on the Lucid C@t{++} compiler (@code{lcc}) encoding algorithm. |
c906108c SS |
9483 | |
9484 | @item arm | |
b37052ae | 9485 | Decode using the algorithm in the @cite{C@t{++} Annotated Reference Manual}. |
c906108c SS |
9486 | @strong{Warning:} this setting alone is not sufficient to allow |
9487 | debugging @code{cfront}-generated executables. @value{GDBN} would | |
9488 | require further enhancement to permit that. | |
9489 | ||
9490 | @end table | |
9491 | If you omit @var{style}, you will see a list of possible formats. | |
9492 | ||
c906108c | 9493 | @item show demangle-style |
b37052ae | 9494 | Display the encoding style currently in use for decoding C@t{++} symbols. |
c906108c | 9495 | |
c906108c SS |
9496 | @item set print object |
9497 | @itemx set print object on | |
4644b6e3 | 9498 | @cindex derived type of an object, printing |
9c16f35a | 9499 | @cindex display derived types |
c906108c SS |
9500 | When displaying a pointer to an object, identify the @emph{actual} |
9501 | (derived) type of the object rather than the @emph{declared} type, using | |
625c0d47 TT |
9502 | the virtual function table. Note that the virtual function table is |
9503 | required---this feature can only work for objects that have run-time | |
9504 | type identification; a single virtual method in the object's declared | |
8264ba82 AG |
9505 | type is sufficient. Note that this setting is also taken into account when |
9506 | working with variable objects via MI (@pxref{GDB/MI}). | |
c906108c SS |
9507 | |
9508 | @item set print object off | |
9509 | Display only the declared type of objects, without reference to the | |
9510 | virtual function table. This is the default setting. | |
9511 | ||
c906108c SS |
9512 | @item show print object |
9513 | Show whether actual, or declared, object types are displayed. | |
9514 | ||
c906108c SS |
9515 | @item set print static-members |
9516 | @itemx set print static-members on | |
4644b6e3 | 9517 | @cindex static members of C@t{++} objects |
b37052ae | 9518 | Print static members when displaying a C@t{++} object. The default is on. |
c906108c SS |
9519 | |
9520 | @item set print static-members off | |
b37052ae | 9521 | Do not print static members when displaying a C@t{++} object. |
c906108c | 9522 | |
c906108c | 9523 | @item show print static-members |
9c16f35a EZ |
9524 | Show whether C@t{++} static members are printed or not. |
9525 | ||
9526 | @item set print pascal_static-members | |
9527 | @itemx set print pascal_static-members on | |
d3e8051b EZ |
9528 | @cindex static members of Pascal objects |
9529 | @cindex Pascal objects, static members display | |
9c16f35a EZ |
9530 | Print static members when displaying a Pascal object. The default is on. |
9531 | ||
9532 | @item set print pascal_static-members off | |
9533 | Do not print static members when displaying a Pascal object. | |
9534 | ||
9535 | @item show print pascal_static-members | |
9536 | Show whether Pascal static members are printed or not. | |
c906108c SS |
9537 | |
9538 | @c These don't work with HP ANSI C++ yet. | |
c906108c SS |
9539 | @item set print vtbl |
9540 | @itemx set print vtbl on | |
4644b6e3 | 9541 | @cindex pretty print C@t{++} virtual function tables |
9c16f35a EZ |
9542 | @cindex virtual functions (C@t{++}) display |
9543 | @cindex VTBL display | |
b37052ae | 9544 | Pretty print C@t{++} virtual function tables. The default is off. |
c906108c | 9545 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 9546 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
9547 | |
9548 | @item set print vtbl off | |
b37052ae | 9549 | Do not pretty print C@t{++} virtual function tables. |
c906108c | 9550 | |
c906108c | 9551 | @item show print vtbl |
b37052ae | 9552 | Show whether C@t{++} virtual function tables are pretty printed, or not. |
c906108c | 9553 | @end table |
c906108c | 9554 | |
4c374409 JK |
9555 | @node Pretty Printing |
9556 | @section Pretty Printing | |
9557 | ||
9558 | @value{GDBN} provides a mechanism to allow pretty-printing of values using | |
9559 | Python code. It greatly simplifies the display of complex objects. This | |
9560 | mechanism works for both MI and the CLI. | |
9561 | ||
7b51bc51 DE |
9562 | @menu |
9563 | * Pretty-Printer Introduction:: Introduction to pretty-printers | |
9564 | * Pretty-Printer Example:: An example pretty-printer | |
9565 | * Pretty-Printer Commands:: Pretty-printer commands | |
9566 | @end menu | |
9567 | ||
9568 | @node Pretty-Printer Introduction | |
9569 | @subsection Pretty-Printer Introduction | |
9570 | ||
9571 | When @value{GDBN} prints a value, it first sees if there is a pretty-printer | |
9572 | registered for the value. If there is then @value{GDBN} invokes the | |
9573 | pretty-printer to print the value. Otherwise the value is printed normally. | |
9574 | ||
9575 | Pretty-printers are normally named. This makes them easy to manage. | |
9576 | The @samp{info pretty-printer} command will list all the installed | |
9577 | pretty-printers with their names. | |
9578 | If a pretty-printer can handle multiple data types, then its | |
9579 | @dfn{subprinters} are the printers for the individual data types. | |
9580 | Each such subprinter has its own name. | |
4e04c971 | 9581 | The format of the name is @var{printer-name};@var{subprinter-name}. |
7b51bc51 DE |
9582 | |
9583 | Pretty-printers are installed by @dfn{registering} them with @value{GDBN}. | |
9584 | Typically they are automatically loaded and registered when the corresponding | |
9585 | debug information is loaded, thus making them available without having to | |
9586 | do anything special. | |
9587 | ||
9588 | There are three places where a pretty-printer can be registered. | |
9589 | ||
9590 | @itemize @bullet | |
9591 | @item | |
9592 | Pretty-printers registered globally are available when debugging | |
9593 | all inferiors. | |
9594 | ||
9595 | @item | |
9596 | Pretty-printers registered with a program space are available only | |
9597 | when debugging that program. | |
9598 | @xref{Progspaces In Python}, for more details on program spaces in Python. | |
9599 | ||
9600 | @item | |
9601 | Pretty-printers registered with an objfile are loaded and unloaded | |
9602 | with the corresponding objfile (e.g., shared library). | |
9603 | @xref{Objfiles In Python}, for more details on objfiles in Python. | |
9604 | @end itemize | |
9605 | ||
9606 | @xref{Selecting Pretty-Printers}, for further information on how | |
9607 | pretty-printers are selected, | |
9608 | ||
9609 | @xref{Writing a Pretty-Printer}, for implementing pretty printers | |
9610 | for new types. | |
9611 | ||
9612 | @node Pretty-Printer Example | |
9613 | @subsection Pretty-Printer Example | |
9614 | ||
9615 | Here is how a C@t{++} @code{std::string} looks without a pretty-printer: | |
4c374409 JK |
9616 | |
9617 | @smallexample | |
9618 | (@value{GDBP}) print s | |
9619 | $1 = @{ | |
9620 | static npos = 4294967295, | |
9621 | _M_dataplus = @{ | |
9622 | <std::allocator<char>> = @{ | |
9623 | <__gnu_cxx::new_allocator<char>> = @{ | |
9624 | <No data fields>@}, <No data fields> | |
9625 | @}, | |
9626 | members of std::basic_string<char, std::char_traits<char>, | |
9627 | std::allocator<char> >::_Alloc_hider: | |
9628 | _M_p = 0x804a014 "abcd" | |
9629 | @} | |
9630 | @} | |
9631 | @end smallexample | |
9632 | ||
9633 | With a pretty-printer for @code{std::string} only the contents are printed: | |
9634 | ||
9635 | @smallexample | |
9636 | (@value{GDBP}) print s | |
9637 | $2 = "abcd" | |
9638 | @end smallexample | |
9639 | ||
7b51bc51 DE |
9640 | @node Pretty-Printer Commands |
9641 | @subsection Pretty-Printer Commands | |
9642 | @cindex pretty-printer commands | |
9643 | ||
9644 | @table @code | |
9645 | @kindex info pretty-printer | |
9646 | @item info pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
9647 | Print the list of installed pretty-printers. | |
9648 | This includes disabled pretty-printers, which are marked as such. | |
9649 | ||
9650 | @var{object-regexp} is a regular expression matching the objects | |
9651 | whose pretty-printers to list. | |
9652 | Objects can be @code{global}, the program space's file | |
9653 | (@pxref{Progspaces In Python}), | |
9654 | and the object files within that program space (@pxref{Objfiles In Python}). | |
9655 | @xref{Selecting Pretty-Printers}, for details on how @value{GDBN} | |
9656 | looks up a printer from these three objects. | |
9657 | ||
9658 | @var{name-regexp} is a regular expression matching the name of the printers | |
9659 | to list. | |
9660 | ||
9661 | @kindex disable pretty-printer | |
9662 | @item disable pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
9663 | Disable pretty-printers matching @var{object-regexp} and @var{name-regexp}. | |
9664 | A disabled pretty-printer is not forgotten, it may be enabled again later. | |
9665 | ||
9666 | @kindex enable pretty-printer | |
9667 | @item enable pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
9668 | Enable pretty-printers matching @var{object-regexp} and @var{name-regexp}. | |
9669 | @end table | |
9670 | ||
9671 | Example: | |
9672 | ||
9673 | Suppose we have three pretty-printers installed: one from library1.so | |
9674 | named @code{foo} that prints objects of type @code{foo}, and | |
9675 | another from library2.so named @code{bar} that prints two types of objects, | |
9676 | @code{bar1} and @code{bar2}. | |
9677 | ||
9678 | @smallexample | |
9679 | (gdb) info pretty-printer | |
9680 | library1.so: | |
9681 | foo | |
9682 | library2.so: | |
9683 | bar | |
9684 | bar1 | |
9685 | bar2 | |
9686 | (gdb) info pretty-printer library2 | |
9687 | library2.so: | |
9688 | bar | |
9689 | bar1 | |
9690 | bar2 | |
9691 | (gdb) disable pretty-printer library1 | |
9692 | 1 printer disabled | |
9693 | 2 of 3 printers enabled | |
9694 | (gdb) info pretty-printer | |
9695 | library1.so: | |
9696 | foo [disabled] | |
9697 | library2.so: | |
9698 | bar | |
9699 | bar1 | |
9700 | bar2 | |
9701 | (gdb) disable pretty-printer library2 bar:bar1 | |
9702 | 1 printer disabled | |
9703 | 1 of 3 printers enabled | |
9704 | (gdb) info pretty-printer library2 | |
9705 | library1.so: | |
9706 | foo [disabled] | |
9707 | library2.so: | |
9708 | bar | |
9709 | bar1 [disabled] | |
9710 | bar2 | |
9711 | (gdb) disable pretty-printer library2 bar | |
9712 | 1 printer disabled | |
9713 | 0 of 3 printers enabled | |
9714 | (gdb) info pretty-printer library2 | |
9715 | library1.so: | |
9716 | foo [disabled] | |
9717 | library2.so: | |
9718 | bar [disabled] | |
9719 | bar1 [disabled] | |
9720 | bar2 | |
9721 | @end smallexample | |
9722 | ||
9723 | Note that for @code{bar} the entire printer can be disabled, | |
9724 | as can each individual subprinter. | |
4c374409 | 9725 | |
6d2ebf8b | 9726 | @node Value History |
79a6e687 | 9727 | @section Value History |
c906108c SS |
9728 | |
9729 | @cindex value history | |
9c16f35a | 9730 | @cindex history of values printed by @value{GDBN} |
5d161b24 DB |
9731 | Values printed by the @code{print} command are saved in the @value{GDBN} |
9732 | @dfn{value history}. This allows you to refer to them in other expressions. | |
9733 | Values are kept until the symbol table is re-read or discarded | |
9734 | (for example with the @code{file} or @code{symbol-file} commands). | |
9735 | When the symbol table changes, the value history is discarded, | |
9736 | since the values may contain pointers back to the types defined in the | |
c906108c SS |
9737 | symbol table. |
9738 | ||
9739 | @cindex @code{$} | |
9740 | @cindex @code{$$} | |
9741 | @cindex history number | |
9742 | The values printed are given @dfn{history numbers} by which you can | |
9743 | refer to them. These are successive integers starting with one. | |
9744 | @code{print} shows you the history number assigned to a value by | |
9745 | printing @samp{$@var{num} = } before the value; here @var{num} is the | |
9746 | history number. | |
9747 | ||
9748 | To refer to any previous value, use @samp{$} followed by the value's | |
9749 | history number. The way @code{print} labels its output is designed to | |
9750 | remind you of this. Just @code{$} refers to the most recent value in | |
9751 | the history, and @code{$$} refers to the value before that. | |
9752 | @code{$$@var{n}} refers to the @var{n}th value from the end; @code{$$2} | |
9753 | is the value just prior to @code{$$}, @code{$$1} is equivalent to | |
9754 | @code{$$}, and @code{$$0} is equivalent to @code{$}. | |
9755 | ||
9756 | For example, suppose you have just printed a pointer to a structure and | |
9757 | want to see the contents of the structure. It suffices to type | |
9758 | ||
474c8240 | 9759 | @smallexample |
c906108c | 9760 | p *$ |
474c8240 | 9761 | @end smallexample |
c906108c SS |
9762 | |
9763 | If you have a chain of structures where the component @code{next} points | |
9764 | to the next one, you can print the contents of the next one with this: | |
9765 | ||
474c8240 | 9766 | @smallexample |
c906108c | 9767 | p *$.next |
474c8240 | 9768 | @end smallexample |
c906108c SS |
9769 | |
9770 | @noindent | |
9771 | You can print successive links in the chain by repeating this | |
9772 | command---which you can do by just typing @key{RET}. | |
9773 | ||
9774 | Note that the history records values, not expressions. If the value of | |
9775 | @code{x} is 4 and you type these commands: | |
9776 | ||
474c8240 | 9777 | @smallexample |
c906108c SS |
9778 | print x |
9779 | set x=5 | |
474c8240 | 9780 | @end smallexample |
c906108c SS |
9781 | |
9782 | @noindent | |
9783 | then the value recorded in the value history by the @code{print} command | |
9784 | remains 4 even though the value of @code{x} has changed. | |
9785 | ||
9786 | @table @code | |
9787 | @kindex show values | |
9788 | @item show values | |
9789 | Print the last ten values in the value history, with their item numbers. | |
9790 | This is like @samp{p@ $$9} repeated ten times, except that @code{show | |
9791 | values} does not change the history. | |
9792 | ||
9793 | @item show values @var{n} | |
9794 | Print ten history values centered on history item number @var{n}. | |
9795 | ||
9796 | @item show values + | |
9797 | Print ten history values just after the values last printed. If no more | |
9798 | values are available, @code{show values +} produces no display. | |
9799 | @end table | |
9800 | ||
9801 | Pressing @key{RET} to repeat @code{show values @var{n}} has exactly the | |
9802 | same effect as @samp{show values +}. | |
9803 | ||
6d2ebf8b | 9804 | @node Convenience Vars |
79a6e687 | 9805 | @section Convenience Variables |
c906108c SS |
9806 | |
9807 | @cindex convenience variables | |
9c16f35a | 9808 | @cindex user-defined variables |
c906108c SS |
9809 | @value{GDBN} provides @dfn{convenience variables} that you can use within |
9810 | @value{GDBN} to hold on to a value and refer to it later. These variables | |
9811 | exist entirely within @value{GDBN}; they are not part of your program, and | |
9812 | setting a convenience variable has no direct effect on further execution | |
9813 | of your program. That is why you can use them freely. | |
9814 | ||
9815 | Convenience variables are prefixed with @samp{$}. Any name preceded by | |
9816 | @samp{$} can be used for a convenience variable, unless it is one of | |
d4f3574e | 9817 | the predefined machine-specific register names (@pxref{Registers, ,Registers}). |
c906108c | 9818 | (Value history references, in contrast, are @emph{numbers} preceded |
79a6e687 | 9819 | by @samp{$}. @xref{Value History, ,Value History}.) |
c906108c SS |
9820 | |
9821 | You can save a value in a convenience variable with an assignment | |
9822 | expression, just as you would set a variable in your program. | |
9823 | For example: | |
9824 | ||
474c8240 | 9825 | @smallexample |
c906108c | 9826 | set $foo = *object_ptr |
474c8240 | 9827 | @end smallexample |
c906108c SS |
9828 | |
9829 | @noindent | |
9830 | would save in @code{$foo} the value contained in the object pointed to by | |
9831 | @code{object_ptr}. | |
9832 | ||
9833 | Using a convenience variable for the first time creates it, but its | |
9834 | value is @code{void} until you assign a new value. You can alter the | |
9835 | value with another assignment at any time. | |
9836 | ||
9837 | Convenience variables have no fixed types. You can assign a convenience | |
9838 | variable any type of value, including structures and arrays, even if | |
9839 | that variable already has a value of a different type. The convenience | |
9840 | variable, when used as an expression, has the type of its current value. | |
9841 | ||
9842 | @table @code | |
9843 | @kindex show convenience | |
f47f77df | 9844 | @cindex show all user variables and functions |
c906108c | 9845 | @item show convenience |
f47f77df DE |
9846 | Print a list of convenience variables used so far, and their values, |
9847 | as well as a list of the convenience functions. | |
d4f3574e | 9848 | Abbreviated @code{show conv}. |
53e5f3cf AS |
9849 | |
9850 | @kindex init-if-undefined | |
9851 | @cindex convenience variables, initializing | |
9852 | @item init-if-undefined $@var{variable} = @var{expression} | |
9853 | Set a convenience variable if it has not already been set. This is useful | |
9854 | for user-defined commands that keep some state. It is similar, in concept, | |
9855 | to using local static variables with initializers in C (except that | |
9856 | convenience variables are global). It can also be used to allow users to | |
9857 | override default values used in a command script. | |
9858 | ||
9859 | If the variable is already defined then the expression is not evaluated so | |
9860 | any side-effects do not occur. | |
c906108c SS |
9861 | @end table |
9862 | ||
9863 | One of the ways to use a convenience variable is as a counter to be | |
9864 | incremented or a pointer to be advanced. For example, to print | |
9865 | a field from successive elements of an array of structures: | |
9866 | ||
474c8240 | 9867 | @smallexample |
c906108c SS |
9868 | set $i = 0 |
9869 | print bar[$i++]->contents | |
474c8240 | 9870 | @end smallexample |
c906108c | 9871 | |
d4f3574e SS |
9872 | @noindent |
9873 | Repeat that command by typing @key{RET}. | |
c906108c SS |
9874 | |
9875 | Some convenience variables are created automatically by @value{GDBN} and given | |
9876 | values likely to be useful. | |
9877 | ||
9878 | @table @code | |
41afff9a | 9879 | @vindex $_@r{, convenience variable} |
c906108c SS |
9880 | @item $_ |
9881 | The variable @code{$_} is automatically set by the @code{x} command to | |
79a6e687 | 9882 | the last address examined (@pxref{Memory, ,Examining Memory}). Other |
c906108c SS |
9883 | commands which provide a default address for @code{x} to examine also |
9884 | set @code{$_} to that address; these commands include @code{info line} | |
9885 | and @code{info breakpoint}. The type of @code{$_} is @code{void *} | |
9886 | except when set by the @code{x} command, in which case it is a pointer | |
9887 | to the type of @code{$__}. | |
9888 | ||
41afff9a | 9889 | @vindex $__@r{, convenience variable} |
c906108c SS |
9890 | @item $__ |
9891 | The variable @code{$__} is automatically set by the @code{x} command | |
9892 | to the value found in the last address examined. Its type is chosen | |
9893 | to match the format in which the data was printed. | |
9894 | ||
9895 | @item $_exitcode | |
41afff9a | 9896 | @vindex $_exitcode@r{, convenience variable} |
0c557179 SDJ |
9897 | When the program being debugged terminates normally, @value{GDBN} |
9898 | automatically sets this variable to the exit code of the program, and | |
9899 | resets @code{$_exitsignal} to @code{void}. | |
9900 | ||
9901 | @item $_exitsignal | |
9902 | @vindex $_exitsignal@r{, convenience variable} | |
9903 | When the program being debugged dies due to an uncaught signal, | |
9904 | @value{GDBN} automatically sets this variable to that signal's number, | |
9905 | and resets @code{$_exitcode} to @code{void}. | |
9906 | ||
9907 | To distinguish between whether the program being debugged has exited | |
9908 | (i.e., @code{$_exitcode} is not @code{void}) or signalled (i.e., | |
9909 | @code{$_exitsignal} is not @code{void}), the convenience function | |
9910 | @code{$_isvoid} can be used (@pxref{Convenience Funs,, Convenience | |
9911 | Functions}). For example, considering the following source code: | |
9912 | ||
9913 | @smallexample | |
9914 | #include <signal.h> | |
9915 | ||
9916 | int | |
9917 | main (int argc, char *argv[]) | |
9918 | @{ | |
9919 | raise (SIGALRM); | |
9920 | return 0; | |
9921 | @} | |
9922 | @end smallexample | |
9923 | ||
9924 | A valid way of telling whether the program being debugged has exited | |
9925 | or signalled would be: | |
9926 | ||
9927 | @smallexample | |
9928 | (@value{GDBP}) define has_exited_or_signalled | |
9929 | Type commands for definition of ``has_exited_or_signalled''. | |
9930 | End with a line saying just ``end''. | |
9931 | >if $_isvoid ($_exitsignal) | |
9932 | >echo The program has exited\n | |
9933 | >else | |
9934 | >echo The program has signalled\n | |
9935 | >end | |
9936 | >end | |
9937 | (@value{GDBP}) run | |
9938 | Starting program: | |
9939 | ||
9940 | Program terminated with signal SIGALRM, Alarm clock. | |
9941 | The program no longer exists. | |
9942 | (@value{GDBP}) has_exited_or_signalled | |
9943 | The program has signalled | |
9944 | @end smallexample | |
9945 | ||
9946 | As can be seen, @value{GDBN} correctly informs that the program being | |
9947 | debugged has signalled, since it calls @code{raise} and raises a | |
9948 | @code{SIGALRM} signal. If the program being debugged had not called | |
9949 | @code{raise}, then @value{GDBN} would report a normal exit: | |
9950 | ||
9951 | @smallexample | |
9952 | (@value{GDBP}) has_exited_or_signalled | |
9953 | The program has exited | |
9954 | @end smallexample | |
4aa995e1 | 9955 | |
72f1fe8a TT |
9956 | @item $_exception |
9957 | The variable @code{$_exception} is set to the exception object being | |
9958 | thrown at an exception-related catchpoint. @xref{Set Catchpoints}. | |
9959 | ||
62e5f89c SDJ |
9960 | @item $_probe_argc |
9961 | @itemx $_probe_arg0@dots{}$_probe_arg11 | |
9962 | Arguments to a static probe. @xref{Static Probe Points}. | |
9963 | ||
0fb4aa4b PA |
9964 | @item $_sdata |
9965 | @vindex $_sdata@r{, inspect, convenience variable} | |
9966 | The variable @code{$_sdata} contains extra collected static tracepoint | |
9967 | data. @xref{Tracepoint Actions,,Tracepoint Action Lists}. Note that | |
9968 | @code{$_sdata} could be empty, if not inspecting a trace buffer, or | |
9969 | if extra static tracepoint data has not been collected. | |
9970 | ||
4aa995e1 PA |
9971 | @item $_siginfo |
9972 | @vindex $_siginfo@r{, convenience variable} | |
ec7e75e7 PP |
9973 | The variable @code{$_siginfo} contains extra signal information |
9974 | (@pxref{extra signal information}). Note that @code{$_siginfo} | |
9975 | could be empty, if the application has not yet received any signals. | |
9976 | For example, it will be empty before you execute the @code{run} command. | |
711e434b PM |
9977 | |
9978 | @item $_tlb | |
9979 | @vindex $_tlb@r{, convenience variable} | |
9980 | The variable @code{$_tlb} is automatically set when debugging | |
9981 | applications running on MS-Windows in native mode or connected to | |
9982 | gdbserver that supports the @code{qGetTIBAddr} request. | |
9983 | @xref{General Query Packets}. | |
9984 | This variable contains the address of the thread information block. | |
9985 | ||
c906108c SS |
9986 | @end table |
9987 | ||
53a5351d JM |
9988 | On HP-UX systems, if you refer to a function or variable name that |
9989 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
9990 | name first, before it searches for a convenience variable. | |
c906108c | 9991 | |
a72c3253 DE |
9992 | @node Convenience Funs |
9993 | @section Convenience Functions | |
9994 | ||
bc3b79fd TJB |
9995 | @cindex convenience functions |
9996 | @value{GDBN} also supplies some @dfn{convenience functions}. These | |
9997 | have a syntax similar to convenience variables. A convenience | |
9998 | function can be used in an expression just like an ordinary function; | |
9999 | however, a convenience function is implemented internally to | |
10000 | @value{GDBN}. | |
10001 | ||
a280dbd1 SDJ |
10002 | These functions do not require @value{GDBN} to be configured with |
10003 | @code{Python} support, which means that they are always available. | |
10004 | ||
10005 | @table @code | |
10006 | ||
10007 | @item $_isvoid (@var{expr}) | |
10008 | @findex $_isvoid@r{, convenience function} | |
10009 | Return one if the expression @var{expr} is @code{void}. Otherwise it | |
10010 | returns zero. | |
10011 | ||
10012 | A @code{void} expression is an expression where the type of the result | |
10013 | is @code{void}. For example, you can examine a convenience variable | |
10014 | (see @ref{Convenience Vars,, Convenience Variables}) to check whether | |
10015 | it is @code{void}: | |
10016 | ||
10017 | @smallexample | |
10018 | (@value{GDBP}) print $_exitcode | |
10019 | $1 = void | |
10020 | (@value{GDBP}) print $_isvoid ($_exitcode) | |
10021 | $2 = 1 | |
10022 | (@value{GDBP}) run | |
10023 | Starting program: ./a.out | |
10024 | [Inferior 1 (process 29572) exited normally] | |
10025 | (@value{GDBP}) print $_exitcode | |
10026 | $3 = 0 | |
10027 | (@value{GDBP}) print $_isvoid ($_exitcode) | |
10028 | $4 = 0 | |
10029 | @end smallexample | |
10030 | ||
10031 | In the example above, we used @code{$_isvoid} to check whether | |
10032 | @code{$_exitcode} is @code{void} before and after the execution of the | |
10033 | program being debugged. Before the execution there is no exit code to | |
10034 | be examined, therefore @code{$_exitcode} is @code{void}. After the | |
10035 | execution the program being debugged returned zero, therefore | |
10036 | @code{$_exitcode} is zero, which means that it is not @code{void} | |
10037 | anymore. | |
10038 | ||
10039 | The @code{void} expression can also be a call of a function from the | |
10040 | program being debugged. For example, given the following function: | |
10041 | ||
10042 | @smallexample | |
10043 | void | |
10044 | foo (void) | |
10045 | @{ | |
10046 | @} | |
10047 | @end smallexample | |
10048 | ||
10049 | The result of calling it inside @value{GDBN} is @code{void}: | |
10050 | ||
10051 | @smallexample | |
10052 | (@value{GDBP}) print foo () | |
10053 | $1 = void | |
10054 | (@value{GDBP}) print $_isvoid (foo ()) | |
10055 | $2 = 1 | |
10056 | (@value{GDBP}) set $v = foo () | |
10057 | (@value{GDBP}) print $v | |
10058 | $3 = void | |
10059 | (@value{GDBP}) print $_isvoid ($v) | |
10060 | $4 = 1 | |
10061 | @end smallexample | |
10062 | ||
10063 | @end table | |
10064 | ||
a72c3253 DE |
10065 | These functions require @value{GDBN} to be configured with |
10066 | @code{Python} support. | |
10067 | ||
10068 | @table @code | |
10069 | ||
10070 | @item $_memeq(@var{buf1}, @var{buf2}, @var{length}) | |
10071 | @findex $_memeq@r{, convenience function} | |
10072 | Returns one if the @var{length} bytes at the addresses given by | |
10073 | @var{buf1} and @var{buf2} are equal. | |
10074 | Otherwise it returns zero. | |
10075 | ||
10076 | @item $_regex(@var{str}, @var{regex}) | |
10077 | @findex $_regex@r{, convenience function} | |
10078 | Returns one if the string @var{str} matches the regular expression | |
10079 | @var{regex}. Otherwise it returns zero. | |
10080 | The syntax of the regular expression is that specified by @code{Python}'s | |
10081 | regular expression support. | |
10082 | ||
10083 | @item $_streq(@var{str1}, @var{str2}) | |
10084 | @findex $_streq@r{, convenience function} | |
10085 | Returns one if the strings @var{str1} and @var{str2} are equal. | |
10086 | Otherwise it returns zero. | |
10087 | ||
10088 | @item $_strlen(@var{str}) | |
10089 | @findex $_strlen@r{, convenience function} | |
10090 | Returns the length of string @var{str}. | |
10091 | ||
faa42425 DE |
10092 | @item $_caller_is(@var{name}@r{[}, @var{number_of_frames}@r{]}) |
10093 | @findex $_caller_is@r{, convenience function} | |
10094 | Returns one if the calling function's name is equal to @var{name}. | |
10095 | Otherwise it returns zero. | |
10096 | ||
10097 | If the optional argument @var{number_of_frames} is provided, | |
10098 | it is the number of frames up in the stack to look. | |
10099 | The default is 1. | |
10100 | ||
10101 | Example: | |
10102 | ||
10103 | @smallexample | |
10104 | (gdb) backtrace | |
10105 | #0 bottom_func () | |
10106 | at testsuite/gdb.python/py-caller-is.c:21 | |
10107 | #1 0x00000000004005a0 in middle_func () | |
10108 | at testsuite/gdb.python/py-caller-is.c:27 | |
10109 | #2 0x00000000004005ab in top_func () | |
10110 | at testsuite/gdb.python/py-caller-is.c:33 | |
10111 | #3 0x00000000004005b6 in main () | |
10112 | at testsuite/gdb.python/py-caller-is.c:39 | |
10113 | (gdb) print $_caller_is ("middle_func") | |
10114 | $1 = 1 | |
10115 | (gdb) print $_caller_is ("top_func", 2) | |
10116 | $1 = 1 | |
10117 | @end smallexample | |
10118 | ||
10119 | @item $_caller_matches(@var{regexp}@r{[}, @var{number_of_frames}@r{]}) | |
10120 | @findex $_caller_matches@r{, convenience function} | |
10121 | Returns one if the calling function's name matches the regular expression | |
10122 | @var{regexp}. Otherwise it returns zero. | |
10123 | ||
10124 | If the optional argument @var{number_of_frames} is provided, | |
10125 | it is the number of frames up in the stack to look. | |
10126 | The default is 1. | |
10127 | ||
10128 | @item $_any_caller_is(@var{name}@r{[}, @var{number_of_frames}@r{]}) | |
10129 | @findex $_any_caller_is@r{, convenience function} | |
10130 | Returns one if any calling function's name is equal to @var{name}. | |
10131 | Otherwise it returns zero. | |
10132 | ||
10133 | If the optional argument @var{number_of_frames} is provided, | |
10134 | it is the number of frames up in the stack to look. | |
10135 | The default is 1. | |
10136 | ||
10137 | This function differs from @code{$_caller_is} in that this function | |
10138 | checks all stack frames from the immediate caller to the frame specified | |
10139 | by @var{number_of_frames}, whereas @code{$_caller_is} only checks the | |
10140 | frame specified by @var{number_of_frames}. | |
10141 | ||
10142 | @item $_any_caller_matches(@var{regexp}@r{[}, @var{number_of_frames}@r{]}) | |
10143 | @findex $_any_caller_matches@r{, convenience function} | |
10144 | Returns one if any calling function's name matches the regular expression | |
10145 | @var{regexp}. Otherwise it returns zero. | |
10146 | ||
10147 | If the optional argument @var{number_of_frames} is provided, | |
10148 | it is the number of frames up in the stack to look. | |
10149 | The default is 1. | |
10150 | ||
10151 | This function differs from @code{$_caller_matches} in that this function | |
10152 | checks all stack frames from the immediate caller to the frame specified | |
10153 | by @var{number_of_frames}, whereas @code{$_caller_matches} only checks the | |
10154 | frame specified by @var{number_of_frames}. | |
10155 | ||
a72c3253 DE |
10156 | @end table |
10157 | ||
10158 | @value{GDBN} provides the ability to list and get help on | |
10159 | convenience functions. | |
10160 | ||
bc3b79fd TJB |
10161 | @table @code |
10162 | @item help function | |
10163 | @kindex help function | |
10164 | @cindex show all convenience functions | |
10165 | Print a list of all convenience functions. | |
10166 | @end table | |
10167 | ||
6d2ebf8b | 10168 | @node Registers |
c906108c SS |
10169 | @section Registers |
10170 | ||
10171 | @cindex registers | |
10172 | You can refer to machine register contents, in expressions, as variables | |
10173 | with names starting with @samp{$}. The names of registers are different | |
10174 | for each machine; use @code{info registers} to see the names used on | |
10175 | your machine. | |
10176 | ||
10177 | @table @code | |
10178 | @kindex info registers | |
10179 | @item info registers | |
10180 | Print the names and values of all registers except floating-point | |
c85508ee | 10181 | and vector registers (in the selected stack frame). |
c906108c SS |
10182 | |
10183 | @kindex info all-registers | |
10184 | @cindex floating point registers | |
10185 | @item info all-registers | |
10186 | Print the names and values of all registers, including floating-point | |
c85508ee | 10187 | and vector registers (in the selected stack frame). |
c906108c SS |
10188 | |
10189 | @item info registers @var{regname} @dots{} | |
10190 | Print the @dfn{relativized} value of each specified register @var{regname}. | |
5d161b24 | 10191 | As discussed in detail below, register values are normally relative to |
697aa1b7 | 10192 | the selected stack frame. The @var{regname} may be any register name valid on |
c906108c SS |
10193 | the machine you are using, with or without the initial @samp{$}. |
10194 | @end table | |
10195 | ||
e09f16f9 EZ |
10196 | @cindex stack pointer register |
10197 | @cindex program counter register | |
10198 | @cindex process status register | |
10199 | @cindex frame pointer register | |
10200 | @cindex standard registers | |
c906108c SS |
10201 | @value{GDBN} has four ``standard'' register names that are available (in |
10202 | expressions) on most machines---whenever they do not conflict with an | |
10203 | architecture's canonical mnemonics for registers. The register names | |
10204 | @code{$pc} and @code{$sp} are used for the program counter register and | |
10205 | the stack pointer. @code{$fp} is used for a register that contains a | |
10206 | pointer to the current stack frame, and @code{$ps} is used for a | |
10207 | register that contains the processor status. For example, | |
10208 | you could print the program counter in hex with | |
10209 | ||
474c8240 | 10210 | @smallexample |
c906108c | 10211 | p/x $pc |
474c8240 | 10212 | @end smallexample |
c906108c SS |
10213 | |
10214 | @noindent | |
10215 | or print the instruction to be executed next with | |
10216 | ||
474c8240 | 10217 | @smallexample |
c906108c | 10218 | x/i $pc |
474c8240 | 10219 | @end smallexample |
c906108c SS |
10220 | |
10221 | @noindent | |
10222 | or add four to the stack pointer@footnote{This is a way of removing | |
10223 | one word from the stack, on machines where stacks grow downward in | |
10224 | memory (most machines, nowadays). This assumes that the innermost | |
10225 | stack frame is selected; setting @code{$sp} is not allowed when other | |
10226 | stack frames are selected. To pop entire frames off the stack, | |
10227 | regardless of machine architecture, use @code{return}; | |
79a6e687 | 10228 | see @ref{Returning, ,Returning from a Function}.} with |
c906108c | 10229 | |
474c8240 | 10230 | @smallexample |
c906108c | 10231 | set $sp += 4 |
474c8240 | 10232 | @end smallexample |
c906108c SS |
10233 | |
10234 | Whenever possible, these four standard register names are available on | |
10235 | your machine even though the machine has different canonical mnemonics, | |
10236 | so long as there is no conflict. The @code{info registers} command | |
10237 | shows the canonical names. For example, on the SPARC, @code{info | |
10238 | registers} displays the processor status register as @code{$psr} but you | |
d4f3574e SS |
10239 | can also refer to it as @code{$ps}; and on x86-based machines @code{$ps} |
10240 | is an alias for the @sc{eflags} register. | |
c906108c SS |
10241 | |
10242 | @value{GDBN} always considers the contents of an ordinary register as an | |
10243 | integer when the register is examined in this way. Some machines have | |
10244 | special registers which can hold nothing but floating point; these | |
10245 | registers are considered to have floating point values. There is no way | |
10246 | to refer to the contents of an ordinary register as floating point value | |
10247 | (although you can @emph{print} it as a floating point value with | |
10248 | @samp{print/f $@var{regname}}). | |
10249 | ||
10250 | Some registers have distinct ``raw'' and ``virtual'' data formats. This | |
10251 | means that the data format in which the register contents are saved by | |
10252 | the operating system is not the same one that your program normally | |
10253 | sees. For example, the registers of the 68881 floating point | |
10254 | coprocessor are always saved in ``extended'' (raw) format, but all C | |
10255 | programs expect to work with ``double'' (virtual) format. In such | |
5d161b24 | 10256 | cases, @value{GDBN} normally works with the virtual format only (the format |
c906108c SS |
10257 | that makes sense for your program), but the @code{info registers} command |
10258 | prints the data in both formats. | |
10259 | ||
36b80e65 EZ |
10260 | @cindex SSE registers (x86) |
10261 | @cindex MMX registers (x86) | |
10262 | Some machines have special registers whose contents can be interpreted | |
10263 | in several different ways. For example, modern x86-based machines | |
10264 | have SSE and MMX registers that can hold several values packed | |
10265 | together in several different formats. @value{GDBN} refers to such | |
10266 | registers in @code{struct} notation: | |
10267 | ||
10268 | @smallexample | |
10269 | (@value{GDBP}) print $xmm1 | |
10270 | $1 = @{ | |
10271 | v4_float = @{0, 3.43859137e-038, 1.54142831e-044, 1.821688e-044@}, | |
10272 | v2_double = @{9.92129282474342e-303, 2.7585945287983262e-313@}, | |
10273 | v16_int8 = "\000\000\000\000\3706;\001\v\000\000\000\r\000\000", | |
10274 | v8_int16 = @{0, 0, 14072, 315, 11, 0, 13, 0@}, | |
10275 | v4_int32 = @{0, 20657912, 11, 13@}, | |
10276 | v2_int64 = @{88725056443645952, 55834574859@}, | |
10277 | uint128 = 0x0000000d0000000b013b36f800000000 | |
10278 | @} | |
10279 | @end smallexample | |
10280 | ||
10281 | @noindent | |
10282 | To set values of such registers, you need to tell @value{GDBN} which | |
10283 | view of the register you wish to change, as if you were assigning | |
10284 | value to a @code{struct} member: | |
10285 | ||
10286 | @smallexample | |
10287 | (@value{GDBP}) set $xmm1.uint128 = 0x000000000000000000000000FFFFFFFF | |
10288 | @end smallexample | |
10289 | ||
c906108c | 10290 | Normally, register values are relative to the selected stack frame |
79a6e687 | 10291 | (@pxref{Selection, ,Selecting a Frame}). This means that you get the |
c906108c SS |
10292 | value that the register would contain if all stack frames farther in |
10293 | were exited and their saved registers restored. In order to see the | |
10294 | true contents of hardware registers, you must select the innermost | |
10295 | frame (with @samp{frame 0}). | |
10296 | ||
901461f8 PA |
10297 | @cindex caller-saved registers |
10298 | @cindex call-clobbered registers | |
10299 | @cindex volatile registers | |
10300 | @cindex <not saved> values | |
10301 | Usually ABIs reserve some registers as not needed to be saved by the | |
10302 | callee (a.k.a.: ``caller-saved'', ``call-clobbered'' or ``volatile'' | |
10303 | registers). It may therefore not be possible for @value{GDBN} to know | |
10304 | the value a register had before the call (in other words, in the outer | |
10305 | frame), if the register value has since been changed by the callee. | |
10306 | @value{GDBN} tries to deduce where the inner frame saved | |
10307 | (``callee-saved'') registers, from the debug info, unwind info, or the | |
10308 | machine code generated by your compiler. If some register is not | |
10309 | saved, and @value{GDBN} knows the register is ``caller-saved'' (via | |
10310 | its own knowledge of the ABI, or because the debug/unwind info | |
10311 | explicitly says the register's value is undefined), @value{GDBN} | |
10312 | displays @w{@samp{<not saved>}} as the register's value. With targets | |
10313 | that @value{GDBN} has no knowledge of the register saving convention, | |
10314 | if a register was not saved by the callee, then its value and location | |
10315 | in the outer frame are assumed to be the same of the inner frame. | |
10316 | This is usually harmless, because if the register is call-clobbered, | |
10317 | the caller either does not care what is in the register after the | |
10318 | call, or has code to restore the value that it does care about. Note, | |
10319 | however, that if you change such a register in the outer frame, you | |
10320 | may also be affecting the inner frame. Also, the more ``outer'' the | |
10321 | frame is you're looking at, the more likely a call-clobbered | |
10322 | register's value is to be wrong, in the sense that it doesn't actually | |
10323 | represent the value the register had just before the call. | |
c906108c | 10324 | |
6d2ebf8b | 10325 | @node Floating Point Hardware |
79a6e687 | 10326 | @section Floating Point Hardware |
c906108c SS |
10327 | @cindex floating point |
10328 | ||
10329 | Depending on the configuration, @value{GDBN} may be able to give | |
10330 | you more information about the status of the floating point hardware. | |
10331 | ||
10332 | @table @code | |
10333 | @kindex info float | |
10334 | @item info float | |
10335 | Display hardware-dependent information about the floating | |
10336 | point unit. The exact contents and layout vary depending on the | |
10337 | floating point chip. Currently, @samp{info float} is supported on | |
10338 | the ARM and x86 machines. | |
10339 | @end table | |
c906108c | 10340 | |
e76f1f2e AC |
10341 | @node Vector Unit |
10342 | @section Vector Unit | |
10343 | @cindex vector unit | |
10344 | ||
10345 | Depending on the configuration, @value{GDBN} may be able to give you | |
10346 | more information about the status of the vector unit. | |
10347 | ||
10348 | @table @code | |
10349 | @kindex info vector | |
10350 | @item info vector | |
10351 | Display information about the vector unit. The exact contents and | |
10352 | layout vary depending on the hardware. | |
10353 | @end table | |
10354 | ||
721c2651 | 10355 | @node OS Information |
79a6e687 | 10356 | @section Operating System Auxiliary Information |
721c2651 EZ |
10357 | @cindex OS information |
10358 | ||
10359 | @value{GDBN} provides interfaces to useful OS facilities that can help | |
10360 | you debug your program. | |
10361 | ||
b383017d RM |
10362 | @cindex auxiliary vector |
10363 | @cindex vector, auxiliary | |
b383017d RM |
10364 | Some operating systems supply an @dfn{auxiliary vector} to programs at |
10365 | startup. This is akin to the arguments and environment that you | |
10366 | specify for a program, but contains a system-dependent variety of | |
10367 | binary values that tell system libraries important details about the | |
10368 | hardware, operating system, and process. Each value's purpose is | |
10369 | identified by an integer tag; the meanings are well-known but system-specific. | |
10370 | Depending on the configuration and operating system facilities, | |
9c16f35a EZ |
10371 | @value{GDBN} may be able to show you this information. For remote |
10372 | targets, this functionality may further depend on the remote stub's | |
427c3a89 DJ |
10373 | support of the @samp{qXfer:auxv:read} packet, see |
10374 | @ref{qXfer auxiliary vector read}. | |
b383017d RM |
10375 | |
10376 | @table @code | |
10377 | @kindex info auxv | |
10378 | @item info auxv | |
10379 | Display the auxiliary vector of the inferior, which can be either a | |
e4937fc1 | 10380 | live process or a core dump file. @value{GDBN} prints each tag value |
b383017d RM |
10381 | numerically, and also shows names and text descriptions for recognized |
10382 | tags. Some values in the vector are numbers, some bit masks, and some | |
e4937fc1 | 10383 | pointers to strings or other data. @value{GDBN} displays each value in the |
b383017d RM |
10384 | most appropriate form for a recognized tag, and in hexadecimal for |
10385 | an unrecognized tag. | |
10386 | @end table | |
10387 | ||
85d4a676 SS |
10388 | On some targets, @value{GDBN} can access operating system-specific |
10389 | information and show it to you. The types of information available | |
10390 | will differ depending on the type of operating system running on the | |
10391 | target. The mechanism used to fetch the data is described in | |
10392 | @ref{Operating System Information}. For remote targets, this | |
10393 | functionality depends on the remote stub's support of the | |
07e059b5 VP |
10394 | @samp{qXfer:osdata:read} packet, see @ref{qXfer osdata read}. |
10395 | ||
10396 | @table @code | |
a61408f8 | 10397 | @kindex info os |
85d4a676 SS |
10398 | @item info os @var{infotype} |
10399 | ||
10400 | Display OS information of the requested type. | |
a61408f8 | 10401 | |
85d4a676 SS |
10402 | On @sc{gnu}/Linux, the following values of @var{infotype} are valid: |
10403 | ||
10404 | @anchor{linux info os infotypes} | |
10405 | @table @code | |
07e059b5 | 10406 | @kindex info os processes |
85d4a676 | 10407 | @item processes |
07e059b5 | 10408 | Display the list of processes on the target. For each process, |
85d4a676 SS |
10409 | @value{GDBN} prints the process identifier, the name of the user, the |
10410 | command corresponding to the process, and the list of processor cores | |
10411 | that the process is currently running on. (To understand what these | |
10412 | properties mean, for this and the following info types, please consult | |
10413 | the general @sc{gnu}/Linux documentation.) | |
10414 | ||
10415 | @kindex info os procgroups | |
10416 | @item procgroups | |
10417 | Display the list of process groups on the target. For each process, | |
10418 | @value{GDBN} prints the identifier of the process group that it belongs | |
10419 | to, the command corresponding to the process group leader, the process | |
10420 | identifier, and the command line of the process. The list is sorted | |
10421 | first by the process group identifier, then by the process identifier, | |
10422 | so that processes belonging to the same process group are grouped together | |
10423 | and the process group leader is listed first. | |
10424 | ||
10425 | @kindex info os threads | |
10426 | @item threads | |
10427 | Display the list of threads running on the target. For each thread, | |
10428 | @value{GDBN} prints the identifier of the process that the thread | |
10429 | belongs to, the command of the process, the thread identifier, and the | |
10430 | processor core that it is currently running on. The main thread of a | |
10431 | process is not listed. | |
10432 | ||
10433 | @kindex info os files | |
10434 | @item files | |
10435 | Display the list of open file descriptors on the target. For each | |
10436 | file descriptor, @value{GDBN} prints the identifier of the process | |
10437 | owning the descriptor, the command of the owning process, the value | |
10438 | of the descriptor, and the target of the descriptor. | |
10439 | ||
10440 | @kindex info os sockets | |
10441 | @item sockets | |
10442 | Display the list of Internet-domain sockets on the target. For each | |
10443 | socket, @value{GDBN} prints the address and port of the local and | |
10444 | remote endpoints, the current state of the connection, the creator of | |
10445 | the socket, the IP address family of the socket, and the type of the | |
10446 | connection. | |
10447 | ||
10448 | @kindex info os shm | |
10449 | @item shm | |
10450 | Display the list of all System V shared-memory regions on the target. | |
10451 | For each shared-memory region, @value{GDBN} prints the region key, | |
10452 | the shared-memory identifier, the access permissions, the size of the | |
10453 | region, the process that created the region, the process that last | |
10454 | attached to or detached from the region, the current number of live | |
10455 | attaches to the region, and the times at which the region was last | |
10456 | attached to, detach from, and changed. | |
10457 | ||
10458 | @kindex info os semaphores | |
10459 | @item semaphores | |
10460 | Display the list of all System V semaphore sets on the target. For each | |
10461 | semaphore set, @value{GDBN} prints the semaphore set key, the semaphore | |
10462 | set identifier, the access permissions, the number of semaphores in the | |
10463 | set, the user and group of the owner and creator of the semaphore set, | |
10464 | and the times at which the semaphore set was operated upon and changed. | |
10465 | ||
10466 | @kindex info os msg | |
10467 | @item msg | |
10468 | Display the list of all System V message queues on the target. For each | |
10469 | message queue, @value{GDBN} prints the message queue key, the message | |
10470 | queue identifier, the access permissions, the current number of bytes | |
10471 | on the queue, the current number of messages on the queue, the processes | |
10472 | that last sent and received a message on the queue, the user and group | |
10473 | of the owner and creator of the message queue, the times at which a | |
10474 | message was last sent and received on the queue, and the time at which | |
10475 | the message queue was last changed. | |
10476 | ||
10477 | @kindex info os modules | |
10478 | @item modules | |
10479 | Display the list of all loaded kernel modules on the target. For each | |
10480 | module, @value{GDBN} prints the module name, the size of the module in | |
10481 | bytes, the number of times the module is used, the dependencies of the | |
10482 | module, the status of the module, and the address of the loaded module | |
10483 | in memory. | |
10484 | @end table | |
10485 | ||
10486 | @item info os | |
10487 | If @var{infotype} is omitted, then list the possible values for | |
10488 | @var{infotype} and the kind of OS information available for each | |
10489 | @var{infotype}. If the target does not return a list of possible | |
10490 | types, this command will report an error. | |
07e059b5 | 10491 | @end table |
721c2651 | 10492 | |
29e57380 | 10493 | @node Memory Region Attributes |
79a6e687 | 10494 | @section Memory Region Attributes |
29e57380 C |
10495 | @cindex memory region attributes |
10496 | ||
b383017d | 10497 | @dfn{Memory region attributes} allow you to describe special handling |
fd79ecee DJ |
10498 | required by regions of your target's memory. @value{GDBN} uses |
10499 | attributes to determine whether to allow certain types of memory | |
10500 | accesses; whether to use specific width accesses; and whether to cache | |
10501 | target memory. By default the description of memory regions is | |
10502 | fetched from the target (if the current target supports this), but the | |
10503 | user can override the fetched regions. | |
29e57380 C |
10504 | |
10505 | Defined memory regions can be individually enabled and disabled. When a | |
10506 | memory region is disabled, @value{GDBN} uses the default attributes when | |
10507 | accessing memory in that region. Similarly, if no memory regions have | |
10508 | been defined, @value{GDBN} uses the default attributes when accessing | |
10509 | all memory. | |
10510 | ||
b383017d | 10511 | When a memory region is defined, it is given a number to identify it; |
29e57380 C |
10512 | to enable, disable, or remove a memory region, you specify that number. |
10513 | ||
10514 | @table @code | |
10515 | @kindex mem | |
bfac230e | 10516 | @item mem @var{lower} @var{upper} @var{attributes}@dots{} |
09d4efe1 EZ |
10517 | Define a memory region bounded by @var{lower} and @var{upper} with |
10518 | attributes @var{attributes}@dots{}, and add it to the list of regions | |
10519 | monitored by @value{GDBN}. Note that @var{upper} == 0 is a special | |
d3e8051b | 10520 | case: it is treated as the target's maximum memory address. |
bfac230e | 10521 | (0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.) |
29e57380 | 10522 | |
fd79ecee DJ |
10523 | @item mem auto |
10524 | Discard any user changes to the memory regions and use target-supplied | |
10525 | regions, if available, or no regions if the target does not support. | |
10526 | ||
29e57380 C |
10527 | @kindex delete mem |
10528 | @item delete mem @var{nums}@dots{} | |
09d4efe1 EZ |
10529 | Remove memory regions @var{nums}@dots{} from the list of regions |
10530 | monitored by @value{GDBN}. | |
29e57380 C |
10531 | |
10532 | @kindex disable mem | |
10533 | @item disable mem @var{nums}@dots{} | |
09d4efe1 | 10534 | Disable monitoring of memory regions @var{nums}@dots{}. |
b383017d | 10535 | A disabled memory region is not forgotten. |
29e57380 C |
10536 | It may be enabled again later. |
10537 | ||
10538 | @kindex enable mem | |
10539 | @item enable mem @var{nums}@dots{} | |
09d4efe1 | 10540 | Enable monitoring of memory regions @var{nums}@dots{}. |
29e57380 C |
10541 | |
10542 | @kindex info mem | |
10543 | @item info mem | |
10544 | Print a table of all defined memory regions, with the following columns | |
09d4efe1 | 10545 | for each region: |
29e57380 C |
10546 | |
10547 | @table @emph | |
10548 | @item Memory Region Number | |
10549 | @item Enabled or Disabled. | |
b383017d | 10550 | Enabled memory regions are marked with @samp{y}. |
29e57380 C |
10551 | Disabled memory regions are marked with @samp{n}. |
10552 | ||
10553 | @item Lo Address | |
10554 | The address defining the inclusive lower bound of the memory region. | |
10555 | ||
10556 | @item Hi Address | |
10557 | The address defining the exclusive upper bound of the memory region. | |
10558 | ||
10559 | @item Attributes | |
10560 | The list of attributes set for this memory region. | |
10561 | @end table | |
10562 | @end table | |
10563 | ||
10564 | ||
10565 | @subsection Attributes | |
10566 | ||
b383017d | 10567 | @subsubsection Memory Access Mode |
29e57380 C |
10568 | The access mode attributes set whether @value{GDBN} may make read or |
10569 | write accesses to a memory region. | |
10570 | ||
10571 | While these attributes prevent @value{GDBN} from performing invalid | |
10572 | memory accesses, they do nothing to prevent the target system, I/O DMA, | |
359df76b | 10573 | etc.@: from accessing memory. |
29e57380 C |
10574 | |
10575 | @table @code | |
10576 | @item ro | |
10577 | Memory is read only. | |
10578 | @item wo | |
10579 | Memory is write only. | |
10580 | @item rw | |
6ca652b0 | 10581 | Memory is read/write. This is the default. |
29e57380 C |
10582 | @end table |
10583 | ||
10584 | @subsubsection Memory Access Size | |
d3e8051b | 10585 | The access size attribute tells @value{GDBN} to use specific sized |
29e57380 C |
10586 | accesses in the memory region. Often memory mapped device registers |
10587 | require specific sized accesses. If no access size attribute is | |
10588 | specified, @value{GDBN} may use accesses of any size. | |
10589 | ||
10590 | @table @code | |
10591 | @item 8 | |
10592 | Use 8 bit memory accesses. | |
10593 | @item 16 | |
10594 | Use 16 bit memory accesses. | |
10595 | @item 32 | |
10596 | Use 32 bit memory accesses. | |
10597 | @item 64 | |
10598 | Use 64 bit memory accesses. | |
10599 | @end table | |
10600 | ||
10601 | @c @subsubsection Hardware/Software Breakpoints | |
10602 | @c The hardware/software breakpoint attributes set whether @value{GDBN} | |
10603 | @c will use hardware or software breakpoints for the internal breakpoints | |
10604 | @c used by the step, next, finish, until, etc. commands. | |
10605 | @c | |
10606 | @c @table @code | |
10607 | @c @item hwbreak | |
b383017d | 10608 | @c Always use hardware breakpoints |
29e57380 C |
10609 | @c @item swbreak (default) |
10610 | @c @end table | |
10611 | ||
10612 | @subsubsection Data Cache | |
10613 | The data cache attributes set whether @value{GDBN} will cache target | |
10614 | memory. While this generally improves performance by reducing debug | |
10615 | protocol overhead, it can lead to incorrect results because @value{GDBN} | |
10616 | does not know about volatile variables or memory mapped device | |
10617 | registers. | |
10618 | ||
10619 | @table @code | |
10620 | @item cache | |
b383017d | 10621 | Enable @value{GDBN} to cache target memory. |
6ca652b0 EZ |
10622 | @item nocache |
10623 | Disable @value{GDBN} from caching target memory. This is the default. | |
29e57380 C |
10624 | @end table |
10625 | ||
4b5752d0 VP |
10626 | @subsection Memory Access Checking |
10627 | @value{GDBN} can be instructed to refuse accesses to memory that is | |
10628 | not explicitly described. This can be useful if accessing such | |
10629 | regions has undesired effects for a specific target, or to provide | |
10630 | better error checking. The following commands control this behaviour. | |
10631 | ||
10632 | @table @code | |
10633 | @kindex set mem inaccessible-by-default | |
10634 | @item set mem inaccessible-by-default [on|off] | |
10635 | If @code{on} is specified, make @value{GDBN} treat memory not | |
10636 | explicitly described by the memory ranges as non-existent and refuse accesses | |
10637 | to such memory. The checks are only performed if there's at least one | |
10638 | memory range defined. If @code{off} is specified, make @value{GDBN} | |
10639 | treat the memory not explicitly described by the memory ranges as RAM. | |
56cf5405 | 10640 | The default value is @code{on}. |
4b5752d0 VP |
10641 | @kindex show mem inaccessible-by-default |
10642 | @item show mem inaccessible-by-default | |
10643 | Show the current handling of accesses to unknown memory. | |
10644 | @end table | |
10645 | ||
10646 | ||
29e57380 | 10647 | @c @subsubsection Memory Write Verification |
b383017d | 10648 | @c The memory write verification attributes set whether @value{GDBN} |
29e57380 C |
10649 | @c will re-reads data after each write to verify the write was successful. |
10650 | @c | |
10651 | @c @table @code | |
10652 | @c @item verify | |
10653 | @c @item noverify (default) | |
10654 | @c @end table | |
10655 | ||
16d9dec6 | 10656 | @node Dump/Restore Files |
79a6e687 | 10657 | @section Copy Between Memory and a File |
16d9dec6 MS |
10658 | @cindex dump/restore files |
10659 | @cindex append data to a file | |
10660 | @cindex dump data to a file | |
10661 | @cindex restore data from a file | |
16d9dec6 | 10662 | |
df5215a6 JB |
10663 | You can use the commands @code{dump}, @code{append}, and |
10664 | @code{restore} to copy data between target memory and a file. The | |
10665 | @code{dump} and @code{append} commands write data to a file, and the | |
10666 | @code{restore} command reads data from a file back into the inferior's | |
10667 | memory. Files may be in binary, Motorola S-record, Intel hex, or | |
10668 | Tektronix Hex format; however, @value{GDBN} can only append to binary | |
10669 | files. | |
10670 | ||
10671 | @table @code | |
10672 | ||
10673 | @kindex dump | |
10674 | @item dump @r{[}@var{format}@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
10675 | @itemx dump @r{[}@var{format}@r{]} value @var{filename} @var{expr} | |
10676 | Dump the contents of memory from @var{start_addr} to @var{end_addr}, | |
10677 | or the value of @var{expr}, to @var{filename} in the given format. | |
16d9dec6 | 10678 | |
df5215a6 | 10679 | The @var{format} parameter may be any one of: |
16d9dec6 | 10680 | @table @code |
df5215a6 JB |
10681 | @item binary |
10682 | Raw binary form. | |
10683 | @item ihex | |
10684 | Intel hex format. | |
10685 | @item srec | |
10686 | Motorola S-record format. | |
10687 | @item tekhex | |
10688 | Tektronix Hex format. | |
10689 | @end table | |
10690 | ||
10691 | @value{GDBN} uses the same definitions of these formats as the | |
10692 | @sc{gnu} binary utilities, like @samp{objdump} and @samp{objcopy}. If | |
10693 | @var{format} is omitted, @value{GDBN} dumps the data in raw binary | |
10694 | form. | |
10695 | ||
10696 | @kindex append | |
10697 | @item append @r{[}binary@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
10698 | @itemx append @r{[}binary@r{]} value @var{filename} @var{expr} | |
10699 | Append the contents of memory from @var{start_addr} to @var{end_addr}, | |
09d4efe1 | 10700 | or the value of @var{expr}, to the file @var{filename}, in raw binary form. |
df5215a6 JB |
10701 | (@value{GDBN} can only append data to files in raw binary form.) |
10702 | ||
10703 | @kindex restore | |
10704 | @item restore @var{filename} @r{[}binary@r{]} @var{bias} @var{start} @var{end} | |
10705 | Restore the contents of file @var{filename} into memory. The | |
10706 | @code{restore} command can automatically recognize any known @sc{bfd} | |
10707 | file format, except for raw binary. To restore a raw binary file you | |
10708 | must specify the optional keyword @code{binary} after the filename. | |
16d9dec6 | 10709 | |
b383017d | 10710 | If @var{bias} is non-zero, its value will be added to the addresses |
16d9dec6 MS |
10711 | contained in the file. Binary files always start at address zero, so |
10712 | they will be restored at address @var{bias}. Other bfd files have | |
10713 | a built-in location; they will be restored at offset @var{bias} | |
10714 | from that location. | |
10715 | ||
10716 | If @var{start} and/or @var{end} are non-zero, then only data between | |
10717 | file offset @var{start} and file offset @var{end} will be restored. | |
b383017d | 10718 | These offsets are relative to the addresses in the file, before |
16d9dec6 MS |
10719 | the @var{bias} argument is applied. |
10720 | ||
10721 | @end table | |
10722 | ||
384ee23f EZ |
10723 | @node Core File Generation |
10724 | @section How to Produce a Core File from Your Program | |
10725 | @cindex dump core from inferior | |
10726 | ||
10727 | A @dfn{core file} or @dfn{core dump} is a file that records the memory | |
10728 | image of a running process and its process status (register values | |
10729 | etc.). Its primary use is post-mortem debugging of a program that | |
10730 | crashed while it ran outside a debugger. A program that crashes | |
10731 | automatically produces a core file, unless this feature is disabled by | |
10732 | the user. @xref{Files}, for information on invoking @value{GDBN} in | |
10733 | the post-mortem debugging mode. | |
10734 | ||
10735 | Occasionally, you may wish to produce a core file of the program you | |
10736 | are debugging in order to preserve a snapshot of its state. | |
10737 | @value{GDBN} has a special command for that. | |
10738 | ||
10739 | @table @code | |
10740 | @kindex gcore | |
10741 | @kindex generate-core-file | |
10742 | @item generate-core-file [@var{file}] | |
10743 | @itemx gcore [@var{file}] | |
10744 | Produce a core dump of the inferior process. The optional argument | |
10745 | @var{file} specifies the file name where to put the core dump. If not | |
10746 | specified, the file name defaults to @file{core.@var{pid}}, where | |
10747 | @var{pid} is the inferior process ID. | |
10748 | ||
10749 | Note that this command is implemented only for some systems (as of | |
05b4bd79 | 10750 | this writing, @sc{gnu}/Linux, FreeBSD, Solaris, and S390). |
384ee23f EZ |
10751 | @end table |
10752 | ||
a0eb71c5 KB |
10753 | @node Character Sets |
10754 | @section Character Sets | |
10755 | @cindex character sets | |
10756 | @cindex charset | |
10757 | @cindex translating between character sets | |
10758 | @cindex host character set | |
10759 | @cindex target character set | |
10760 | ||
10761 | If the program you are debugging uses a different character set to | |
10762 | represent characters and strings than the one @value{GDBN} uses itself, | |
10763 | @value{GDBN} can automatically translate between the character sets for | |
10764 | you. The character set @value{GDBN} uses we call the @dfn{host | |
10765 | character set}; the one the inferior program uses we call the | |
10766 | @dfn{target character set}. | |
10767 | ||
10768 | For example, if you are running @value{GDBN} on a @sc{gnu}/Linux system, which | |
10769 | uses the ISO Latin 1 character set, but you are using @value{GDBN}'s | |
ea35711c | 10770 | remote protocol (@pxref{Remote Debugging}) to debug a program |
a0eb71c5 KB |
10771 | running on an IBM mainframe, which uses the @sc{ebcdic} character set, |
10772 | then the host character set is Latin-1, and the target character set is | |
10773 | @sc{ebcdic}. If you give @value{GDBN} the command @code{set | |
e33d66ec | 10774 | target-charset EBCDIC-US}, then @value{GDBN} translates between |
a0eb71c5 KB |
10775 | @sc{ebcdic} and Latin 1 as you print character or string values, or use |
10776 | character and string literals in expressions. | |
10777 | ||
10778 | @value{GDBN} has no way to automatically recognize which character set | |
10779 | the inferior program uses; you must tell it, using the @code{set | |
10780 | target-charset} command, described below. | |
10781 | ||
10782 | Here are the commands for controlling @value{GDBN}'s character set | |
10783 | support: | |
10784 | ||
10785 | @table @code | |
10786 | @item set target-charset @var{charset} | |
10787 | @kindex set target-charset | |
10af6951 EZ |
10788 | Set the current target character set to @var{charset}. To display the |
10789 | list of supported target character sets, type | |
10790 | @kbd{@w{set target-charset @key{TAB}@key{TAB}}}. | |
a0eb71c5 | 10791 | |
a0eb71c5 KB |
10792 | @item set host-charset @var{charset} |
10793 | @kindex set host-charset | |
10794 | Set the current host character set to @var{charset}. | |
10795 | ||
10796 | By default, @value{GDBN} uses a host character set appropriate to the | |
10797 | system it is running on; you can override that default using the | |
732f6a93 TT |
10798 | @code{set host-charset} command. On some systems, @value{GDBN} cannot |
10799 | automatically determine the appropriate host character set. In this | |
10800 | case, @value{GDBN} uses @samp{UTF-8}. | |
a0eb71c5 KB |
10801 | |
10802 | @value{GDBN} can only use certain character sets as its host character | |
c1b6b909 | 10803 | set. If you type @kbd{@w{set host-charset @key{TAB}@key{TAB}}}, |
10af6951 | 10804 | @value{GDBN} will list the host character sets it supports. |
a0eb71c5 KB |
10805 | |
10806 | @item set charset @var{charset} | |
10807 | @kindex set charset | |
e33d66ec | 10808 | Set the current host and target character sets to @var{charset}. As |
10af6951 EZ |
10809 | above, if you type @kbd{@w{set charset @key{TAB}@key{TAB}}}, |
10810 | @value{GDBN} will list the names of the character sets that can be used | |
e33d66ec EZ |
10811 | for both host and target. |
10812 | ||
a0eb71c5 | 10813 | @item show charset |
a0eb71c5 | 10814 | @kindex show charset |
10af6951 | 10815 | Show the names of the current host and target character sets. |
e33d66ec | 10816 | |
10af6951 | 10817 | @item show host-charset |
a0eb71c5 | 10818 | @kindex show host-charset |
10af6951 | 10819 | Show the name of the current host character set. |
e33d66ec | 10820 | |
10af6951 | 10821 | @item show target-charset |
a0eb71c5 | 10822 | @kindex show target-charset |
10af6951 | 10823 | Show the name of the current target character set. |
a0eb71c5 | 10824 | |
10af6951 EZ |
10825 | @item set target-wide-charset @var{charset} |
10826 | @kindex set target-wide-charset | |
10827 | Set the current target's wide character set to @var{charset}. This is | |
10828 | the character set used by the target's @code{wchar_t} type. To | |
10829 | display the list of supported wide character sets, type | |
10830 | @kbd{@w{set target-wide-charset @key{TAB}@key{TAB}}}. | |
10831 | ||
10832 | @item show target-wide-charset | |
10833 | @kindex show target-wide-charset | |
10834 | Show the name of the current target's wide character set. | |
a0eb71c5 KB |
10835 | @end table |
10836 | ||
a0eb71c5 KB |
10837 | Here is an example of @value{GDBN}'s character set support in action. |
10838 | Assume that the following source code has been placed in the file | |
10839 | @file{charset-test.c}: | |
10840 | ||
10841 | @smallexample | |
10842 | #include <stdio.h> | |
10843 | ||
10844 | char ascii_hello[] | |
10845 | = @{72, 101, 108, 108, 111, 44, 32, 119, | |
10846 | 111, 114, 108, 100, 33, 10, 0@}; | |
10847 | char ibm1047_hello[] | |
10848 | = @{200, 133, 147, 147, 150, 107, 64, 166, | |
10849 | 150, 153, 147, 132, 90, 37, 0@}; | |
10850 | ||
10851 | main () | |
10852 | @{ | |
10853 | printf ("Hello, world!\n"); | |
10854 | @} | |
10998722 | 10855 | @end smallexample |
a0eb71c5 KB |
10856 | |
10857 | In this program, @code{ascii_hello} and @code{ibm1047_hello} are arrays | |
10858 | containing the string @samp{Hello, world!} followed by a newline, | |
10859 | encoded in the @sc{ascii} and @sc{ibm1047} character sets. | |
10860 | ||
10861 | We compile the program, and invoke the debugger on it: | |
10862 | ||
10863 | @smallexample | |
10864 | $ gcc -g charset-test.c -o charset-test | |
10865 | $ gdb -nw charset-test | |
10866 | GNU gdb 2001-12-19-cvs | |
10867 | Copyright 2001 Free Software Foundation, Inc. | |
10868 | @dots{} | |
f7dc1244 | 10869 | (@value{GDBP}) |
10998722 | 10870 | @end smallexample |
a0eb71c5 KB |
10871 | |
10872 | We can use the @code{show charset} command to see what character sets | |
10873 | @value{GDBN} is currently using to interpret and display characters and | |
10874 | strings: | |
10875 | ||
10876 | @smallexample | |
f7dc1244 | 10877 | (@value{GDBP}) show charset |
e33d66ec | 10878 | The current host and target character set is `ISO-8859-1'. |
f7dc1244 | 10879 | (@value{GDBP}) |
10998722 | 10880 | @end smallexample |
a0eb71c5 KB |
10881 | |
10882 | For the sake of printing this manual, let's use @sc{ascii} as our | |
10883 | initial character set: | |
10884 | @smallexample | |
f7dc1244 EZ |
10885 | (@value{GDBP}) set charset ASCII |
10886 | (@value{GDBP}) show charset | |
e33d66ec | 10887 | The current host and target character set is `ASCII'. |
f7dc1244 | 10888 | (@value{GDBP}) |
10998722 | 10889 | @end smallexample |
a0eb71c5 KB |
10890 | |
10891 | Let's assume that @sc{ascii} is indeed the correct character set for our | |
10892 | host system --- in other words, let's assume that if @value{GDBN} prints | |
10893 | characters using the @sc{ascii} character set, our terminal will display | |
10894 | them properly. Since our current target character set is also | |
10895 | @sc{ascii}, the contents of @code{ascii_hello} print legibly: | |
10896 | ||
10897 | @smallexample | |
f7dc1244 | 10898 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 10899 | $1 = 0x401698 "Hello, world!\n" |
f7dc1244 | 10900 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 10901 | $2 = 72 'H' |
f7dc1244 | 10902 | (@value{GDBP}) |
10998722 | 10903 | @end smallexample |
a0eb71c5 KB |
10904 | |
10905 | @value{GDBN} uses the target character set for character and string | |
10906 | literals you use in expressions: | |
10907 | ||
10908 | @smallexample | |
f7dc1244 | 10909 | (@value{GDBP}) print '+' |
a0eb71c5 | 10910 | $3 = 43 '+' |
f7dc1244 | 10911 | (@value{GDBP}) |
10998722 | 10912 | @end smallexample |
a0eb71c5 KB |
10913 | |
10914 | The @sc{ascii} character set uses the number 43 to encode the @samp{+} | |
10915 | character. | |
10916 | ||
10917 | @value{GDBN} relies on the user to tell it which character set the | |
10918 | target program uses. If we print @code{ibm1047_hello} while our target | |
10919 | character set is still @sc{ascii}, we get jibberish: | |
10920 | ||
10921 | @smallexample | |
f7dc1244 | 10922 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 10923 | $4 = 0x4016a8 "\310\205\223\223\226k@@\246\226\231\223\204Z%" |
f7dc1244 | 10924 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 10925 | $5 = 200 '\310' |
f7dc1244 | 10926 | (@value{GDBP}) |
10998722 | 10927 | @end smallexample |
a0eb71c5 | 10928 | |
e33d66ec | 10929 | If we invoke the @code{set target-charset} followed by @key{TAB}@key{TAB}, |
a0eb71c5 KB |
10930 | @value{GDBN} tells us the character sets it supports: |
10931 | ||
10932 | @smallexample | |
f7dc1244 | 10933 | (@value{GDBP}) set target-charset |
b383017d | 10934 | ASCII EBCDIC-US IBM1047 ISO-8859-1 |
f7dc1244 | 10935 | (@value{GDBP}) set target-charset |
10998722 | 10936 | @end smallexample |
a0eb71c5 KB |
10937 | |
10938 | We can select @sc{ibm1047} as our target character set, and examine the | |
10939 | program's strings again. Now the @sc{ascii} string is wrong, but | |
10940 | @value{GDBN} translates the contents of @code{ibm1047_hello} from the | |
10941 | target character set, @sc{ibm1047}, to the host character set, | |
10942 | @sc{ascii}, and they display correctly: | |
10943 | ||
10944 | @smallexample | |
f7dc1244 EZ |
10945 | (@value{GDBP}) set target-charset IBM1047 |
10946 | (@value{GDBP}) show charset | |
e33d66ec EZ |
10947 | The current host character set is `ASCII'. |
10948 | The current target character set is `IBM1047'. | |
f7dc1244 | 10949 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 10950 | $6 = 0x401698 "\110\145%%?\054\040\167?\162%\144\041\012" |
f7dc1244 | 10951 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 10952 | $7 = 72 '\110' |
f7dc1244 | 10953 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 10954 | $8 = 0x4016a8 "Hello, world!\n" |
f7dc1244 | 10955 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 10956 | $9 = 200 'H' |
f7dc1244 | 10957 | (@value{GDBP}) |
10998722 | 10958 | @end smallexample |
a0eb71c5 KB |
10959 | |
10960 | As above, @value{GDBN} uses the target character set for character and | |
10961 | string literals you use in expressions: | |
10962 | ||
10963 | @smallexample | |
f7dc1244 | 10964 | (@value{GDBP}) print '+' |
a0eb71c5 | 10965 | $10 = 78 '+' |
f7dc1244 | 10966 | (@value{GDBP}) |
10998722 | 10967 | @end smallexample |
a0eb71c5 | 10968 | |
e33d66ec | 10969 | The @sc{ibm1047} character set uses the number 78 to encode the @samp{+} |
a0eb71c5 KB |
10970 | character. |
10971 | ||
b12039c6 YQ |
10972 | @node Caching Target Data |
10973 | @section Caching Data of Targets | |
10974 | @cindex caching data of targets | |
10975 | ||
10976 | @value{GDBN} caches data exchanged between the debugger and a target. | |
b26dfc9a YQ |
10977 | Each cache is associated with the address space of the inferior. |
10978 | @xref{Inferiors and Programs}, about inferior and address space. | |
b12039c6 YQ |
10979 | Such caching generally improves performance in remote debugging |
10980 | (@pxref{Remote Debugging}), because it reduces the overhead of the | |
10981 | remote protocol by bundling memory reads and writes into large chunks. | |
10982 | Unfortunately, simply caching everything would lead to incorrect results, | |
10983 | since @value{GDBN} does not necessarily know anything about volatile | |
10984 | values, memory-mapped I/O addresses, etc. Furthermore, in non-stop mode | |
10985 | (@pxref{Non-Stop Mode}) memory can be changed @emph{while} a gdb command | |
10986 | is executing. | |
29b090c0 DE |
10987 | Therefore, by default, @value{GDBN} only caches data |
10988 | known to be on the stack@footnote{In non-stop mode, it is moderately | |
10989 | rare for a running thread to modify the stack of a stopped thread | |
10990 | in a way that would interfere with a backtrace, and caching of | |
29453a14 YQ |
10991 | stack reads provides a significant speed up of remote backtraces.} or |
10992 | in the code segment. | |
29b090c0 | 10993 | Other regions of memory can be explicitly marked as |
27b81af3 | 10994 | cacheable; @pxref{Memory Region Attributes}. |
09d4efe1 EZ |
10995 | |
10996 | @table @code | |
10997 | @kindex set remotecache | |
10998 | @item set remotecache on | |
10999 | @itemx set remotecache off | |
4e5d721f DE |
11000 | This option no longer does anything; it exists for compatibility |
11001 | with old scripts. | |
09d4efe1 EZ |
11002 | |
11003 | @kindex show remotecache | |
11004 | @item show remotecache | |
4e5d721f DE |
11005 | Show the current state of the obsolete remotecache flag. |
11006 | ||
11007 | @kindex set stack-cache | |
11008 | @item set stack-cache on | |
11009 | @itemx set stack-cache off | |
6dd315ba YQ |
11010 | Enable or disable caching of stack accesses. When @code{on}, use |
11011 | caching. By default, this option is @code{on}. | |
4e5d721f DE |
11012 | |
11013 | @kindex show stack-cache | |
11014 | @item show stack-cache | |
11015 | Show the current state of data caching for memory accesses. | |
09d4efe1 | 11016 | |
29453a14 YQ |
11017 | @kindex set code-cache |
11018 | @item set code-cache on | |
11019 | @itemx set code-cache off | |
11020 | Enable or disable caching of code segment accesses. When @code{on}, | |
11021 | use caching. By default, this option is @code{on}. This improves | |
11022 | performance of disassembly in remote debugging. | |
11023 | ||
11024 | @kindex show code-cache | |
11025 | @item show code-cache | |
11026 | Show the current state of target memory cache for code segment | |
11027 | accesses. | |
11028 | ||
09d4efe1 | 11029 | @kindex info dcache |
4e5d721f | 11030 | @item info dcache @r{[}line@r{]} |
b26dfc9a YQ |
11031 | Print the information about the performance of data cache of the |
11032 | current inferior's address space. The information displayed | |
11033 | includes the dcache width and depth, and for each cache line, its | |
11034 | number, address, and how many times it was referenced. This | |
11035 | command is useful for debugging the data cache operation. | |
4e5d721f DE |
11036 | |
11037 | If a line number is specified, the contents of that line will be | |
11038 | printed in hex. | |
1a532630 PP |
11039 | |
11040 | @item set dcache size @var{size} | |
11041 | @cindex dcache size | |
11042 | @kindex set dcache size | |
11043 | Set maximum number of entries in dcache (dcache depth above). | |
11044 | ||
11045 | @item set dcache line-size @var{line-size} | |
11046 | @cindex dcache line-size | |
11047 | @kindex set dcache line-size | |
11048 | Set number of bytes each dcache entry caches (dcache width above). | |
11049 | Must be a power of 2. | |
11050 | ||
11051 | @item show dcache size | |
11052 | @kindex show dcache size | |
b12039c6 | 11053 | Show maximum number of dcache entries. @xref{Caching Target Data, info dcache}. |
1a532630 PP |
11054 | |
11055 | @item show dcache line-size | |
11056 | @kindex show dcache line-size | |
b12039c6 | 11057 | Show default size of dcache lines. |
1a532630 | 11058 | |
09d4efe1 EZ |
11059 | @end table |
11060 | ||
08388c79 DE |
11061 | @node Searching Memory |
11062 | @section Search Memory | |
11063 | @cindex searching memory | |
11064 | ||
11065 | Memory can be searched for a particular sequence of bytes with the | |
11066 | @code{find} command. | |
11067 | ||
11068 | @table @code | |
11069 | @kindex find | |
11070 | @item find @r{[}/@var{sn}@r{]} @var{start_addr}, +@var{len}, @var{val1} @r{[}, @var{val2}, @dots{}@r{]} | |
11071 | @itemx find @r{[}/@var{sn}@r{]} @var{start_addr}, @var{end_addr}, @var{val1} @r{[}, @var{val2}, @dots{}@r{]} | |
11072 | Search memory for the sequence of bytes specified by @var{val1}, @var{val2}, | |
11073 | etc. The search begins at address @var{start_addr} and continues for either | |
11074 | @var{len} bytes or through to @var{end_addr} inclusive. | |
11075 | @end table | |
11076 | ||
11077 | @var{s} and @var{n} are optional parameters. | |
11078 | They may be specified in either order, apart or together. | |
11079 | ||
11080 | @table @r | |
11081 | @item @var{s}, search query size | |
11082 | The size of each search query value. | |
11083 | ||
11084 | @table @code | |
11085 | @item b | |
11086 | bytes | |
11087 | @item h | |
11088 | halfwords (two bytes) | |
11089 | @item w | |
11090 | words (four bytes) | |
11091 | @item g | |
11092 | giant words (eight bytes) | |
11093 | @end table | |
11094 | ||
11095 | All values are interpreted in the current language. | |
11096 | This means, for example, that if the current source language is C/C@t{++} | |
11097 | then searching for the string ``hello'' includes the trailing '\0'. | |
11098 | ||
11099 | If the value size is not specified, it is taken from the | |
11100 | value's type in the current language. | |
11101 | This is useful when one wants to specify the search | |
11102 | pattern as a mixture of types. | |
11103 | Note that this means, for example, that in the case of C-like languages | |
11104 | a search for an untyped 0x42 will search for @samp{(int) 0x42} | |
11105 | which is typically four bytes. | |
11106 | ||
11107 | @item @var{n}, maximum number of finds | |
11108 | The maximum number of matches to print. The default is to print all finds. | |
11109 | @end table | |
11110 | ||
11111 | You can use strings as search values. Quote them with double-quotes | |
11112 | (@code{"}). | |
11113 | The string value is copied into the search pattern byte by byte, | |
11114 | regardless of the endianness of the target and the size specification. | |
11115 | ||
11116 | The address of each match found is printed as well as a count of the | |
11117 | number of matches found. | |
11118 | ||
11119 | The address of the last value found is stored in convenience variable | |
11120 | @samp{$_}. | |
11121 | A count of the number of matches is stored in @samp{$numfound}. | |
11122 | ||
11123 | For example, if stopped at the @code{printf} in this function: | |
11124 | ||
11125 | @smallexample | |
11126 | void | |
11127 | hello () | |
11128 | @{ | |
11129 | static char hello[] = "hello-hello"; | |
11130 | static struct @{ char c; short s; int i; @} | |
11131 | __attribute__ ((packed)) mixed | |
11132 | = @{ 'c', 0x1234, 0x87654321 @}; | |
11133 | printf ("%s\n", hello); | |
11134 | @} | |
11135 | @end smallexample | |
11136 | ||
11137 | @noindent | |
11138 | you get during debugging: | |
11139 | ||
11140 | @smallexample | |
11141 | (gdb) find &hello[0], +sizeof(hello), "hello" | |
11142 | 0x804956d <hello.1620+6> | |
11143 | 1 pattern found | |
11144 | (gdb) find &hello[0], +sizeof(hello), 'h', 'e', 'l', 'l', 'o' | |
11145 | 0x8049567 <hello.1620> | |
11146 | 0x804956d <hello.1620+6> | |
11147 | 2 patterns found | |
11148 | (gdb) find /b1 &hello[0], +sizeof(hello), 'h', 0x65, 'l' | |
11149 | 0x8049567 <hello.1620> | |
11150 | 1 pattern found | |
11151 | (gdb) find &mixed, +sizeof(mixed), (char) 'c', (short) 0x1234, (int) 0x87654321 | |
11152 | 0x8049560 <mixed.1625> | |
11153 | 1 pattern found | |
11154 | (gdb) print $numfound | |
11155 | $1 = 1 | |
11156 | (gdb) print $_ | |
11157 | $2 = (void *) 0x8049560 | |
11158 | @end smallexample | |
a0eb71c5 | 11159 | |
edb3359d DJ |
11160 | @node Optimized Code |
11161 | @chapter Debugging Optimized Code | |
11162 | @cindex optimized code, debugging | |
11163 | @cindex debugging optimized code | |
11164 | ||
11165 | Almost all compilers support optimization. With optimization | |
11166 | disabled, the compiler generates assembly code that corresponds | |
11167 | directly to your source code, in a simplistic way. As the compiler | |
11168 | applies more powerful optimizations, the generated assembly code | |
11169 | diverges from your original source code. With help from debugging | |
11170 | information generated by the compiler, @value{GDBN} can map from | |
11171 | the running program back to constructs from your original source. | |
11172 | ||
11173 | @value{GDBN} is more accurate with optimization disabled. If you | |
11174 | can recompile without optimization, it is easier to follow the | |
11175 | progress of your program during debugging. But, there are many cases | |
11176 | where you may need to debug an optimized version. | |
11177 | ||
11178 | When you debug a program compiled with @samp{-g -O}, remember that the | |
11179 | optimizer has rearranged your code; the debugger shows you what is | |
11180 | really there. Do not be too surprised when the execution path does not | |
11181 | exactly match your source file! An extreme example: if you define a | |
11182 | variable, but never use it, @value{GDBN} never sees that | |
11183 | variable---because the compiler optimizes it out of existence. | |
11184 | ||
11185 | Some things do not work as well with @samp{-g -O} as with just | |
11186 | @samp{-g}, particularly on machines with instruction scheduling. If in | |
11187 | doubt, recompile with @samp{-g} alone, and if this fixes the problem, | |
11188 | please report it to us as a bug (including a test case!). | |
11189 | @xref{Variables}, for more information about debugging optimized code. | |
11190 | ||
11191 | @menu | |
11192 | * Inline Functions:: How @value{GDBN} presents inlining | |
111c6489 | 11193 | * Tail Call Frames:: @value{GDBN} analysis of jumps to functions |
edb3359d DJ |
11194 | @end menu |
11195 | ||
11196 | @node Inline Functions | |
11197 | @section Inline Functions | |
11198 | @cindex inline functions, debugging | |
11199 | ||
11200 | @dfn{Inlining} is an optimization that inserts a copy of the function | |
11201 | body directly at each call site, instead of jumping to a shared | |
11202 | routine. @value{GDBN} displays inlined functions just like | |
11203 | non-inlined functions. They appear in backtraces. You can view their | |
11204 | arguments and local variables, step into them with @code{step}, skip | |
11205 | them with @code{next}, and escape from them with @code{finish}. | |
11206 | You can check whether a function was inlined by using the | |
11207 | @code{info frame} command. | |
11208 | ||
11209 | For @value{GDBN} to support inlined functions, the compiler must | |
11210 | record information about inlining in the debug information --- | |
11211 | @value{NGCC} using the @sc{dwarf 2} format does this, and several | |
11212 | other compilers do also. @value{GDBN} only supports inlined functions | |
11213 | when using @sc{dwarf 2}. Versions of @value{NGCC} before 4.1 | |
11214 | do not emit two required attributes (@samp{DW_AT_call_file} and | |
11215 | @samp{DW_AT_call_line}); @value{GDBN} does not display inlined | |
11216 | function calls with earlier versions of @value{NGCC}. It instead | |
11217 | displays the arguments and local variables of inlined functions as | |
11218 | local variables in the caller. | |
11219 | ||
11220 | The body of an inlined function is directly included at its call site; | |
11221 | unlike a non-inlined function, there are no instructions devoted to | |
11222 | the call. @value{GDBN} still pretends that the call site and the | |
11223 | start of the inlined function are different instructions. Stepping to | |
11224 | the call site shows the call site, and then stepping again shows | |
11225 | the first line of the inlined function, even though no additional | |
11226 | instructions are executed. | |
11227 | ||
11228 | This makes source-level debugging much clearer; you can see both the | |
11229 | context of the call and then the effect of the call. Only stepping by | |
11230 | a single instruction using @code{stepi} or @code{nexti} does not do | |
11231 | this; single instruction steps always show the inlined body. | |
11232 | ||
11233 | There are some ways that @value{GDBN} does not pretend that inlined | |
11234 | function calls are the same as normal calls: | |
11235 | ||
11236 | @itemize @bullet | |
edb3359d DJ |
11237 | @item |
11238 | Setting breakpoints at the call site of an inlined function may not | |
11239 | work, because the call site does not contain any code. @value{GDBN} | |
11240 | may incorrectly move the breakpoint to the next line of the enclosing | |
11241 | function, after the call. This limitation will be removed in a future | |
11242 | version of @value{GDBN}; until then, set a breakpoint on an earlier line | |
11243 | or inside the inlined function instead. | |
11244 | ||
11245 | @item | |
11246 | @value{GDBN} cannot locate the return value of inlined calls after | |
11247 | using the @code{finish} command. This is a limitation of compiler-generated | |
11248 | debugging information; after @code{finish}, you can step to the next line | |
11249 | and print a variable where your program stored the return value. | |
11250 | ||
11251 | @end itemize | |
11252 | ||
111c6489 JK |
11253 | @node Tail Call Frames |
11254 | @section Tail Call Frames | |
11255 | @cindex tail call frames, debugging | |
11256 | ||
11257 | Function @code{B} can call function @code{C} in its very last statement. In | |
11258 | unoptimized compilation the call of @code{C} is immediately followed by return | |
11259 | instruction at the end of @code{B} code. Optimizing compiler may replace the | |
11260 | call and return in function @code{B} into one jump to function @code{C} | |
11261 | instead. Such use of a jump instruction is called @dfn{tail call}. | |
11262 | ||
11263 | During execution of function @code{C}, there will be no indication in the | |
11264 | function call stack frames that it was tail-called from @code{B}. If function | |
11265 | @code{A} regularly calls function @code{B} which tail-calls function @code{C}, | |
11266 | then @value{GDBN} will see @code{A} as the caller of @code{C}. However, in | |
11267 | some cases @value{GDBN} can determine that @code{C} was tail-called from | |
11268 | @code{B}, and it will then create fictitious call frame for that, with the | |
11269 | return address set up as if @code{B} called @code{C} normally. | |
11270 | ||
11271 | This functionality is currently supported only by DWARF 2 debugging format and | |
11272 | the compiler has to produce @samp{DW_TAG_GNU_call_site} tags. With | |
11273 | @value{NGCC}, you need to specify @option{-O -g} during compilation, to get | |
11274 | this information. | |
11275 | ||
11276 | @kbd{info frame} command (@pxref{Frame Info}) will indicate the tail call frame | |
11277 | kind by text @code{tail call frame} such as in this sample @value{GDBN} output: | |
11278 | ||
11279 | @smallexample | |
11280 | (gdb) x/i $pc - 2 | |
11281 | 0x40066b <b(int, double)+11>: jmp 0x400640 <c(int, double)> | |
11282 | (gdb) info frame | |
11283 | Stack level 1, frame at 0x7fffffffda30: | |
11284 | rip = 0x40066d in b (amd64-entry-value.cc:59); saved rip 0x4004c5 | |
11285 | tail call frame, caller of frame at 0x7fffffffda30 | |
11286 | source language c++. | |
11287 | Arglist at unknown address. | |
11288 | Locals at unknown address, Previous frame's sp is 0x7fffffffda30 | |
11289 | @end smallexample | |
11290 | ||
11291 | The detection of all the possible code path executions can find them ambiguous. | |
11292 | There is no execution history stored (possible @ref{Reverse Execution} is never | |
11293 | used for this purpose) and the last known caller could have reached the known | |
11294 | callee by multiple different jump sequences. In such case @value{GDBN} still | |
11295 | tries to show at least all the unambiguous top tail callers and all the | |
11296 | unambiguous bottom tail calees, if any. | |
11297 | ||
11298 | @table @code | |
e18b2753 | 11299 | @anchor{set debug entry-values} |
111c6489 JK |
11300 | @item set debug entry-values |
11301 | @kindex set debug entry-values | |
11302 | When set to on, enables printing of analysis messages for both frame argument | |
11303 | values at function entry and tail calls. It will show all the possible valid | |
11304 | tail calls code paths it has considered. It will also print the intersection | |
11305 | of them with the final unambiguous (possibly partial or even empty) code path | |
11306 | result. | |
11307 | ||
11308 | @item show debug entry-values | |
11309 | @kindex show debug entry-values | |
11310 | Show the current state of analysis messages printing for both frame argument | |
11311 | values at function entry and tail calls. | |
11312 | @end table | |
11313 | ||
11314 | The analysis messages for tail calls can for example show why the virtual tail | |
11315 | call frame for function @code{c} has not been recognized (due to the indirect | |
11316 | reference by variable @code{x}): | |
11317 | ||
11318 | @smallexample | |
11319 | static void __attribute__((noinline, noclone)) c (void); | |
11320 | void (*x) (void) = c; | |
11321 | static void __attribute__((noinline, noclone)) a (void) @{ x++; @} | |
11322 | static void __attribute__((noinline, noclone)) c (void) @{ a (); @} | |
11323 | int main (void) @{ x (); return 0; @} | |
11324 | ||
11325 | Breakpoint 1, DW_OP_GNU_entry_value resolving cannot find | |
11326 | DW_TAG_GNU_call_site 0x40039a in main | |
11327 | a () at t.c:3 | |
11328 | 3 static void __attribute__((noinline, noclone)) a (void) @{ x++; @} | |
11329 | (gdb) bt | |
11330 | #0 a () at t.c:3 | |
11331 | #1 0x000000000040039a in main () at t.c:5 | |
11332 | @end smallexample | |
11333 | ||
11334 | Another possibility is an ambiguous virtual tail call frames resolution: | |
11335 | ||
11336 | @smallexample | |
11337 | int i; | |
11338 | static void __attribute__((noinline, noclone)) f (void) @{ i++; @} | |
11339 | static void __attribute__((noinline, noclone)) e (void) @{ f (); @} | |
11340 | static void __attribute__((noinline, noclone)) d (void) @{ f (); @} | |
11341 | static void __attribute__((noinline, noclone)) c (void) @{ d (); @} | |
11342 | static void __attribute__((noinline, noclone)) b (void) | |
11343 | @{ if (i) c (); else e (); @} | |
11344 | static void __attribute__((noinline, noclone)) a (void) @{ b (); @} | |
11345 | int main (void) @{ a (); return 0; @} | |
11346 | ||
11347 | tailcall: initial: 0x4004d2(a) 0x4004ce(b) 0x4004b2(c) 0x4004a2(d) | |
11348 | tailcall: compare: 0x4004d2(a) 0x4004cc(b) 0x400492(e) | |
11349 | tailcall: reduced: 0x4004d2(a) | | |
11350 | (gdb) bt | |
11351 | #0 f () at t.c:2 | |
11352 | #1 0x00000000004004d2 in a () at t.c:8 | |
11353 | #2 0x0000000000400395 in main () at t.c:9 | |
11354 | @end smallexample | |
11355 | ||
5048e516 JK |
11356 | @set CALLSEQ1A @code{main@value{ARROW}a@value{ARROW}b@value{ARROW}c@value{ARROW}d@value{ARROW}f} |
11357 | @set CALLSEQ2A @code{main@value{ARROW}a@value{ARROW}b@value{ARROW}e@value{ARROW}f} | |
11358 | ||
11359 | @c Convert CALLSEQ#A to CALLSEQ#B depending on HAVE_MAKEINFO_CLICK. | |
11360 | @ifset HAVE_MAKEINFO_CLICK | |
11361 | @set ARROW @click{} | |
11362 | @set CALLSEQ1B @clicksequence{@value{CALLSEQ1A}} | |
11363 | @set CALLSEQ2B @clicksequence{@value{CALLSEQ2A}} | |
11364 | @end ifset | |
11365 | @ifclear HAVE_MAKEINFO_CLICK | |
11366 | @set ARROW -> | |
11367 | @set CALLSEQ1B @value{CALLSEQ1A} | |
11368 | @set CALLSEQ2B @value{CALLSEQ2A} | |
11369 | @end ifclear | |
11370 | ||
11371 | Frames #0 and #2 are real, #1 is a virtual tail call frame. | |
11372 | The code can have possible execution paths @value{CALLSEQ1B} or | |
11373 | @value{CALLSEQ2B}, @value{GDBN} cannot find which one from the inferior state. | |
111c6489 JK |
11374 | |
11375 | @code{initial:} state shows some random possible calling sequence @value{GDBN} | |
11376 | has found. It then finds another possible calling sequcen - that one is | |
11377 | prefixed by @code{compare:}. The non-ambiguous intersection of these two is | |
11378 | printed as the @code{reduced:} calling sequence. That one could have many | |
11379 | futher @code{compare:} and @code{reduced:} statements as long as there remain | |
11380 | any non-ambiguous sequence entries. | |
11381 | ||
11382 | For the frame of function @code{b} in both cases there are different possible | |
11383 | @code{$pc} values (@code{0x4004cc} or @code{0x4004ce}), therefore this frame is | |
11384 | also ambigous. The only non-ambiguous frame is the one for function @code{a}, | |
11385 | therefore this one is displayed to the user while the ambiguous frames are | |
11386 | omitted. | |
edb3359d | 11387 | |
e18b2753 JK |
11388 | There can be also reasons why printing of frame argument values at function |
11389 | entry may fail: | |
11390 | ||
11391 | @smallexample | |
11392 | int v; | |
11393 | static void __attribute__((noinline, noclone)) c (int i) @{ v++; @} | |
11394 | static void __attribute__((noinline, noclone)) a (int i); | |
11395 | static void __attribute__((noinline, noclone)) b (int i) @{ a (i); @} | |
11396 | static void __attribute__((noinline, noclone)) a (int i) | |
11397 | @{ if (i) b (i - 1); else c (0); @} | |
11398 | int main (void) @{ a (5); return 0; @} | |
11399 | ||
11400 | (gdb) bt | |
11401 | #0 c (i=i@@entry=0) at t.c:2 | |
11402 | #1 0x0000000000400428 in a (DW_OP_GNU_entry_value resolving has found | |
11403 | function "a" at 0x400420 can call itself via tail calls | |
11404 | i=<optimized out>) at t.c:6 | |
11405 | #2 0x000000000040036e in main () at t.c:7 | |
11406 | @end smallexample | |
11407 | ||
11408 | @value{GDBN} cannot find out from the inferior state if and how many times did | |
11409 | function @code{a} call itself (via function @code{b}) as these calls would be | |
11410 | tail calls. Such tail calls would modify thue @code{i} variable, therefore | |
11411 | @value{GDBN} cannot be sure the value it knows would be right - @value{GDBN} | |
11412 | prints @code{<optimized out>} instead. | |
11413 | ||
e2e0bcd1 JB |
11414 | @node Macros |
11415 | @chapter C Preprocessor Macros | |
11416 | ||
49efadf5 | 11417 | Some languages, such as C and C@t{++}, provide a way to define and invoke |
e2e0bcd1 JB |
11418 | ``preprocessor macros'' which expand into strings of tokens. |
11419 | @value{GDBN} can evaluate expressions containing macro invocations, show | |
11420 | the result of macro expansion, and show a macro's definition, including | |
11421 | where it was defined. | |
11422 | ||
11423 | You may need to compile your program specially to provide @value{GDBN} | |
11424 | with information about preprocessor macros. Most compilers do not | |
11425 | include macros in their debugging information, even when you compile | |
11426 | with the @option{-g} flag. @xref{Compilation}. | |
11427 | ||
11428 | A program may define a macro at one point, remove that definition later, | |
11429 | and then provide a different definition after that. Thus, at different | |
11430 | points in the program, a macro may have different definitions, or have | |
11431 | no definition at all. If there is a current stack frame, @value{GDBN} | |
11432 | uses the macros in scope at that frame's source code line. Otherwise, | |
11433 | @value{GDBN} uses the macros in scope at the current listing location; | |
11434 | see @ref{List}. | |
11435 | ||
e2e0bcd1 JB |
11436 | Whenever @value{GDBN} evaluates an expression, it always expands any |
11437 | macro invocations present in the expression. @value{GDBN} also provides | |
11438 | the following commands for working with macros explicitly. | |
11439 | ||
11440 | @table @code | |
11441 | ||
11442 | @kindex macro expand | |
11443 | @cindex macro expansion, showing the results of preprocessor | |
11444 | @cindex preprocessor macro expansion, showing the results of | |
11445 | @cindex expanding preprocessor macros | |
11446 | @item macro expand @var{expression} | |
11447 | @itemx macro exp @var{expression} | |
11448 | Show the results of expanding all preprocessor macro invocations in | |
11449 | @var{expression}. Since @value{GDBN} simply expands macros, but does | |
11450 | not parse the result, @var{expression} need not be a valid expression; | |
11451 | it can be any string of tokens. | |
11452 | ||
09d4efe1 | 11453 | @kindex macro exp1 |
e2e0bcd1 JB |
11454 | @item macro expand-once @var{expression} |
11455 | @itemx macro exp1 @var{expression} | |
4644b6e3 | 11456 | @cindex expand macro once |
e2e0bcd1 JB |
11457 | @i{(This command is not yet implemented.)} Show the results of |
11458 | expanding those preprocessor macro invocations that appear explicitly in | |
11459 | @var{expression}. Macro invocations appearing in that expansion are | |
11460 | left unchanged. This command allows you to see the effect of a | |
11461 | particular macro more clearly, without being confused by further | |
11462 | expansions. Since @value{GDBN} simply expands macros, but does not | |
11463 | parse the result, @var{expression} need not be a valid expression; it | |
11464 | can be any string of tokens. | |
11465 | ||
475b0867 | 11466 | @kindex info macro |
e2e0bcd1 | 11467 | @cindex macro definition, showing |
9b158ba0 | 11468 | @cindex definition of a macro, showing |
11469 | @cindex macros, from debug info | |
71eba9c2 | 11470 | @item info macro [-a|-all] [--] @var{macro} |
11471 | Show the current definition or all definitions of the named @var{macro}, | |
11472 | and describe the source location or compiler command-line where that | |
11473 | definition was established. The optional double dash is to signify the end of | |
11474 | argument processing and the beginning of @var{macro} for non C-like macros where | |
11475 | the macro may begin with a hyphen. | |
e2e0bcd1 | 11476 | |
9b158ba0 | 11477 | @kindex info macros |
11478 | @item info macros @var{linespec} | |
11479 | Show all macro definitions that are in effect at the location specified | |
11480 | by @var{linespec}, and describe the source location or compiler | |
11481 | command-line where those definitions were established. | |
11482 | ||
e2e0bcd1 JB |
11483 | @kindex macro define |
11484 | @cindex user-defined macros | |
11485 | @cindex defining macros interactively | |
11486 | @cindex macros, user-defined | |
11487 | @item macro define @var{macro} @var{replacement-list} | |
11488 | @itemx macro define @var{macro}(@var{arglist}) @var{replacement-list} | |
d7d9f01e TT |
11489 | Introduce a definition for a preprocessor macro named @var{macro}, |
11490 | invocations of which are replaced by the tokens given in | |
11491 | @var{replacement-list}. The first form of this command defines an | |
11492 | ``object-like'' macro, which takes no arguments; the second form | |
11493 | defines a ``function-like'' macro, which takes the arguments given in | |
11494 | @var{arglist}. | |
11495 | ||
11496 | A definition introduced by this command is in scope in every | |
11497 | expression evaluated in @value{GDBN}, until it is removed with the | |
11498 | @code{macro undef} command, described below. The definition overrides | |
11499 | all definitions for @var{macro} present in the program being debugged, | |
11500 | as well as any previous user-supplied definition. | |
e2e0bcd1 JB |
11501 | |
11502 | @kindex macro undef | |
11503 | @item macro undef @var{macro} | |
d7d9f01e TT |
11504 | Remove any user-supplied definition for the macro named @var{macro}. |
11505 | This command only affects definitions provided with the @code{macro | |
11506 | define} command, described above; it cannot remove definitions present | |
11507 | in the program being debugged. | |
e2e0bcd1 | 11508 | |
09d4efe1 EZ |
11509 | @kindex macro list |
11510 | @item macro list | |
d7d9f01e | 11511 | List all the macros defined using the @code{macro define} command. |
e2e0bcd1 JB |
11512 | @end table |
11513 | ||
11514 | @cindex macros, example of debugging with | |
11515 | Here is a transcript showing the above commands in action. First, we | |
11516 | show our source files: | |
11517 | ||
11518 | @smallexample | |
11519 | $ cat sample.c | |
11520 | #include <stdio.h> | |
11521 | #include "sample.h" | |
11522 | ||
11523 | #define M 42 | |
11524 | #define ADD(x) (M + x) | |
11525 | ||
11526 | main () | |
11527 | @{ | |
11528 | #define N 28 | |
11529 | printf ("Hello, world!\n"); | |
11530 | #undef N | |
11531 | printf ("We're so creative.\n"); | |
11532 | #define N 1729 | |
11533 | printf ("Goodbye, world!\n"); | |
11534 | @} | |
11535 | $ cat sample.h | |
11536 | #define Q < | |
11537 | $ | |
11538 | @end smallexample | |
11539 | ||
e0f8f636 TT |
11540 | Now, we compile the program using the @sc{gnu} C compiler, |
11541 | @value{NGCC}. We pass the @option{-gdwarf-2}@footnote{This is the | |
11542 | minimum. Recent versions of @value{NGCC} support @option{-gdwarf-3} | |
11543 | and @option{-gdwarf-4}; we recommend always choosing the most recent | |
11544 | version of DWARF.} @emph{and} @option{-g3} flags to ensure the compiler | |
11545 | includes information about preprocessor macros in the debugging | |
e2e0bcd1 JB |
11546 | information. |
11547 | ||
11548 | @smallexample | |
11549 | $ gcc -gdwarf-2 -g3 sample.c -o sample | |
11550 | $ | |
11551 | @end smallexample | |
11552 | ||
11553 | Now, we start @value{GDBN} on our sample program: | |
11554 | ||
11555 | @smallexample | |
11556 | $ gdb -nw sample | |
11557 | GNU gdb 2002-05-06-cvs | |
11558 | Copyright 2002 Free Software Foundation, Inc. | |
11559 | GDB is free software, @dots{} | |
f7dc1244 | 11560 | (@value{GDBP}) |
e2e0bcd1 JB |
11561 | @end smallexample |
11562 | ||
11563 | We can expand macros and examine their definitions, even when the | |
11564 | program is not running. @value{GDBN} uses the current listing position | |
11565 | to decide which macro definitions are in scope: | |
11566 | ||
11567 | @smallexample | |
f7dc1244 | 11568 | (@value{GDBP}) list main |
e2e0bcd1 JB |
11569 | 3 |
11570 | 4 #define M 42 | |
11571 | 5 #define ADD(x) (M + x) | |
11572 | 6 | |
11573 | 7 main () | |
11574 | 8 @{ | |
11575 | 9 #define N 28 | |
11576 | 10 printf ("Hello, world!\n"); | |
11577 | 11 #undef N | |
11578 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 11579 | (@value{GDBP}) info macro ADD |
e2e0bcd1 JB |
11580 | Defined at /home/jimb/gdb/macros/play/sample.c:5 |
11581 | #define ADD(x) (M + x) | |
f7dc1244 | 11582 | (@value{GDBP}) info macro Q |
e2e0bcd1 JB |
11583 | Defined at /home/jimb/gdb/macros/play/sample.h:1 |
11584 | included at /home/jimb/gdb/macros/play/sample.c:2 | |
11585 | #define Q < | |
f7dc1244 | 11586 | (@value{GDBP}) macro expand ADD(1) |
e2e0bcd1 | 11587 | expands to: (42 + 1) |
f7dc1244 | 11588 | (@value{GDBP}) macro expand-once ADD(1) |
e2e0bcd1 | 11589 | expands to: once (M + 1) |
f7dc1244 | 11590 | (@value{GDBP}) |
e2e0bcd1 JB |
11591 | @end smallexample |
11592 | ||
d7d9f01e | 11593 | In the example above, note that @code{macro expand-once} expands only |
e2e0bcd1 JB |
11594 | the macro invocation explicit in the original text --- the invocation of |
11595 | @code{ADD} --- but does not expand the invocation of the macro @code{M}, | |
11596 | which was introduced by @code{ADD}. | |
11597 | ||
3f94c067 BW |
11598 | Once the program is running, @value{GDBN} uses the macro definitions in |
11599 | force at the source line of the current stack frame: | |
e2e0bcd1 JB |
11600 | |
11601 | @smallexample | |
f7dc1244 | 11602 | (@value{GDBP}) break main |
e2e0bcd1 | 11603 | Breakpoint 1 at 0x8048370: file sample.c, line 10. |
f7dc1244 | 11604 | (@value{GDBP}) run |
b383017d | 11605 | Starting program: /home/jimb/gdb/macros/play/sample |
e2e0bcd1 JB |
11606 | |
11607 | Breakpoint 1, main () at sample.c:10 | |
11608 | 10 printf ("Hello, world!\n"); | |
f7dc1244 | 11609 | (@value{GDBP}) |
e2e0bcd1 JB |
11610 | @end smallexample |
11611 | ||
11612 | At line 10, the definition of the macro @code{N} at line 9 is in force: | |
11613 | ||
11614 | @smallexample | |
f7dc1244 | 11615 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
11616 | Defined at /home/jimb/gdb/macros/play/sample.c:9 |
11617 | #define N 28 | |
f7dc1244 | 11618 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 11619 | expands to: 28 < 42 |
f7dc1244 | 11620 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 11621 | $1 = 1 |
f7dc1244 | 11622 | (@value{GDBP}) |
e2e0bcd1 JB |
11623 | @end smallexample |
11624 | ||
11625 | As we step over directives that remove @code{N}'s definition, and then | |
11626 | give it a new definition, @value{GDBN} finds the definition (or lack | |
11627 | thereof) in force at each point: | |
11628 | ||
11629 | @smallexample | |
f7dc1244 | 11630 | (@value{GDBP}) next |
e2e0bcd1 JB |
11631 | Hello, world! |
11632 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 11633 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
11634 | The symbol `N' has no definition as a C/C++ preprocessor macro |
11635 | at /home/jimb/gdb/macros/play/sample.c:12 | |
f7dc1244 | 11636 | (@value{GDBP}) next |
e2e0bcd1 JB |
11637 | We're so creative. |
11638 | 14 printf ("Goodbye, world!\n"); | |
f7dc1244 | 11639 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
11640 | Defined at /home/jimb/gdb/macros/play/sample.c:13 |
11641 | #define N 1729 | |
f7dc1244 | 11642 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 11643 | expands to: 1729 < 42 |
f7dc1244 | 11644 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 11645 | $2 = 0 |
f7dc1244 | 11646 | (@value{GDBP}) |
e2e0bcd1 JB |
11647 | @end smallexample |
11648 | ||
484086b7 JK |
11649 | In addition to source files, macros can be defined on the compilation command |
11650 | line using the @option{-D@var{name}=@var{value}} syntax. For macros defined in | |
11651 | such a way, @value{GDBN} displays the location of their definition as line zero | |
11652 | of the source file submitted to the compiler. | |
11653 | ||
11654 | @smallexample | |
11655 | (@value{GDBP}) info macro __STDC__ | |
11656 | Defined at /home/jimb/gdb/macros/play/sample.c:0 | |
11657 | -D__STDC__=1 | |
11658 | (@value{GDBP}) | |
11659 | @end smallexample | |
11660 | ||
e2e0bcd1 | 11661 | |
b37052ae EZ |
11662 | @node Tracepoints |
11663 | @chapter Tracepoints | |
11664 | @c This chapter is based on the documentation written by Michael | |
11665 | @c Snyder, David Taylor, Jim Blandy, and Elena Zannoni. | |
11666 | ||
11667 | @cindex tracepoints | |
11668 | In some applications, it is not feasible for the debugger to interrupt | |
11669 | the program's execution long enough for the developer to learn | |
11670 | anything helpful about its behavior. If the program's correctness | |
11671 | depends on its real-time behavior, delays introduced by a debugger | |
11672 | might cause the program to change its behavior drastically, or perhaps | |
11673 | fail, even when the code itself is correct. It is useful to be able | |
11674 | to observe the program's behavior without interrupting it. | |
11675 | ||
11676 | Using @value{GDBN}'s @code{trace} and @code{collect} commands, you can | |
11677 | specify locations in the program, called @dfn{tracepoints}, and | |
11678 | arbitrary expressions to evaluate when those tracepoints are reached. | |
11679 | Later, using the @code{tfind} command, you can examine the values | |
11680 | those expressions had when the program hit the tracepoints. The | |
11681 | expressions may also denote objects in memory---structures or arrays, | |
11682 | for example---whose values @value{GDBN} should record; while visiting | |
11683 | a particular tracepoint, you may inspect those objects as if they were | |
11684 | in memory at that moment. However, because @value{GDBN} records these | |
11685 | values without interacting with you, it can do so quickly and | |
11686 | unobtrusively, hopefully not disturbing the program's behavior. | |
11687 | ||
11688 | The tracepoint facility is currently available only for remote | |
9d29849a JB |
11689 | targets. @xref{Targets}. In addition, your remote target must know |
11690 | how to collect trace data. This functionality is implemented in the | |
11691 | remote stub; however, none of the stubs distributed with @value{GDBN} | |
11692 | support tracepoints as of this writing. The format of the remote | |
11693 | packets used to implement tracepoints are described in @ref{Tracepoint | |
11694 | Packets}. | |
b37052ae | 11695 | |
00bf0b85 SS |
11696 | It is also possible to get trace data from a file, in a manner reminiscent |
11697 | of corefiles; you specify the filename, and use @code{tfind} to search | |
11698 | through the file. @xref{Trace Files}, for more details. | |
11699 | ||
b37052ae EZ |
11700 | This chapter describes the tracepoint commands and features. |
11701 | ||
11702 | @menu | |
b383017d RM |
11703 | * Set Tracepoints:: |
11704 | * Analyze Collected Data:: | |
11705 | * Tracepoint Variables:: | |
00bf0b85 | 11706 | * Trace Files:: |
b37052ae EZ |
11707 | @end menu |
11708 | ||
11709 | @node Set Tracepoints | |
11710 | @section Commands to Set Tracepoints | |
11711 | ||
11712 | Before running such a @dfn{trace experiment}, an arbitrary number of | |
1042e4c0 SS |
11713 | tracepoints can be set. A tracepoint is actually a special type of |
11714 | breakpoint (@pxref{Set Breaks}), so you can manipulate it using | |
11715 | standard breakpoint commands. For instance, as with breakpoints, | |
11716 | tracepoint numbers are successive integers starting from one, and many | |
11717 | of the commands associated with tracepoints take the tracepoint number | |
11718 | as their argument, to identify which tracepoint to work on. | |
b37052ae EZ |
11719 | |
11720 | For each tracepoint, you can specify, in advance, some arbitrary set | |
11721 | of data that you want the target to collect in the trace buffer when | |
11722 | it hits that tracepoint. The collected data can include registers, | |
11723 | local variables, or global data. Later, you can use @value{GDBN} | |
11724 | commands to examine the values these data had at the time the | |
11725 | tracepoint was hit. | |
11726 | ||
7d13fe92 SS |
11727 | Tracepoints do not support every breakpoint feature. Ignore counts on |
11728 | tracepoints have no effect, and tracepoints cannot run @value{GDBN} | |
11729 | commands when they are hit. Tracepoints may not be thread-specific | |
11730 | either. | |
1042e4c0 | 11731 | |
7a697b8d SS |
11732 | @cindex fast tracepoints |
11733 | Some targets may support @dfn{fast tracepoints}, which are inserted in | |
11734 | a different way (such as with a jump instead of a trap), that is | |
11735 | faster but possibly restricted in where they may be installed. | |
11736 | ||
0fb4aa4b PA |
11737 | @cindex static tracepoints |
11738 | @cindex markers, static tracepoints | |
11739 | @cindex probing markers, static tracepoints | |
11740 | Regular and fast tracepoints are dynamic tracing facilities, meaning | |
11741 | that they can be used to insert tracepoints at (almost) any location | |
11742 | in the target. Some targets may also support controlling @dfn{static | |
11743 | tracepoints} from @value{GDBN}. With static tracing, a set of | |
11744 | instrumentation points, also known as @dfn{markers}, are embedded in | |
11745 | the target program, and can be activated or deactivated by name or | |
11746 | address. These are usually placed at locations which facilitate | |
11747 | investigating what the target is actually doing. @value{GDBN}'s | |
11748 | support for static tracing includes being able to list instrumentation | |
11749 | points, and attach them with @value{GDBN} defined high level | |
11750 | tracepoints that expose the whole range of convenience of | |
8786b2bd | 11751 | @value{GDBN}'s tracepoints support. Namely, support for collecting |
0fb4aa4b PA |
11752 | registers values and values of global or local (to the instrumentation |
11753 | point) variables; tracepoint conditions and trace state variables. | |
11754 | The act of installing a @value{GDBN} static tracepoint on an | |
11755 | instrumentation point, or marker, is referred to as @dfn{probing} a | |
11756 | static tracepoint marker. | |
11757 | ||
fa593d66 PA |
11758 | @code{gdbserver} supports tracepoints on some target systems. |
11759 | @xref{Server,,Tracepoints support in @code{gdbserver}}. | |
11760 | ||
b37052ae EZ |
11761 | This section describes commands to set tracepoints and associated |
11762 | conditions and actions. | |
11763 | ||
11764 | @menu | |
b383017d RM |
11765 | * Create and Delete Tracepoints:: |
11766 | * Enable and Disable Tracepoints:: | |
11767 | * Tracepoint Passcounts:: | |
782b2b07 | 11768 | * Tracepoint Conditions:: |
f61e138d | 11769 | * Trace State Variables:: |
b383017d RM |
11770 | * Tracepoint Actions:: |
11771 | * Listing Tracepoints:: | |
0fb4aa4b | 11772 | * Listing Static Tracepoint Markers:: |
79a6e687 | 11773 | * Starting and Stopping Trace Experiments:: |
c9429232 | 11774 | * Tracepoint Restrictions:: |
b37052ae EZ |
11775 | @end menu |
11776 | ||
11777 | @node Create and Delete Tracepoints | |
11778 | @subsection Create and Delete Tracepoints | |
11779 | ||
11780 | @table @code | |
11781 | @cindex set tracepoint | |
11782 | @kindex trace | |
1042e4c0 | 11783 | @item trace @var{location} |
b37052ae | 11784 | The @code{trace} command is very similar to the @code{break} command. |
1042e4c0 SS |
11785 | Its argument @var{location} can be a source line, a function name, or |
11786 | an address in the target program. @xref{Specify Location}. The | |
11787 | @code{trace} command defines a tracepoint, which is a point in the | |
11788 | target program where the debugger will briefly stop, collect some | |
11789 | data, and then allow the program to continue. Setting a tracepoint or | |
1e4d1764 YQ |
11790 | changing its actions takes effect immediately if the remote stub |
11791 | supports the @samp{InstallInTrace} feature (@pxref{install tracepoint | |
11792 | in tracing}). | |
11793 | If remote stub doesn't support the @samp{InstallInTrace} feature, all | |
11794 | these changes don't take effect until the next @code{tstart} | |
1042e4c0 | 11795 | command, and once a trace experiment is running, further changes will |
bfccc43c YQ |
11796 | not have any effect until the next trace experiment starts. In addition, |
11797 | @value{GDBN} supports @dfn{pending tracepoints}---tracepoints whose | |
11798 | address is not yet resolved. (This is similar to pending breakpoints.) | |
11799 | Pending tracepoints are not downloaded to the target and not installed | |
11800 | until they are resolved. The resolution of pending tracepoints requires | |
11801 | @value{GDBN} support---when debugging with the remote target, and | |
11802 | @value{GDBN} disconnects from the remote stub (@pxref{disconnected | |
11803 | tracing}), pending tracepoints can not be resolved (and downloaded to | |
11804 | the remote stub) while @value{GDBN} is disconnected. | |
b37052ae EZ |
11805 | |
11806 | Here are some examples of using the @code{trace} command: | |
11807 | ||
11808 | @smallexample | |
11809 | (@value{GDBP}) @b{trace foo.c:121} // a source file and line number | |
11810 | ||
11811 | (@value{GDBP}) @b{trace +2} // 2 lines forward | |
11812 | ||
11813 | (@value{GDBP}) @b{trace my_function} // first source line of function | |
11814 | ||
11815 | (@value{GDBP}) @b{trace *my_function} // EXACT start address of function | |
11816 | ||
11817 | (@value{GDBP}) @b{trace *0x2117c4} // an address | |
11818 | @end smallexample | |
11819 | ||
11820 | @noindent | |
11821 | You can abbreviate @code{trace} as @code{tr}. | |
11822 | ||
782b2b07 SS |
11823 | @item trace @var{location} if @var{cond} |
11824 | Set a tracepoint with condition @var{cond}; evaluate the expression | |
11825 | @var{cond} each time the tracepoint is reached, and collect data only | |
11826 | if the value is nonzero---that is, if @var{cond} evaluates as true. | |
11827 | @xref{Tracepoint Conditions, ,Tracepoint Conditions}, for more | |
11828 | information on tracepoint conditions. | |
11829 | ||
7a697b8d SS |
11830 | @item ftrace @var{location} [ if @var{cond} ] |
11831 | @cindex set fast tracepoint | |
74c761c1 | 11832 | @cindex fast tracepoints, setting |
7a697b8d SS |
11833 | @kindex ftrace |
11834 | The @code{ftrace} command sets a fast tracepoint. For targets that | |
11835 | support them, fast tracepoints will use a more efficient but possibly | |
11836 | less general technique to trigger data collection, such as a jump | |
11837 | instruction instead of a trap, or some sort of hardware support. It | |
11838 | may not be possible to create a fast tracepoint at the desired | |
11839 | location, in which case the command will exit with an explanatory | |
11840 | message. | |
11841 | ||
11842 | @value{GDBN} handles arguments to @code{ftrace} exactly as for | |
11843 | @code{trace}. | |
11844 | ||
405f8e94 SS |
11845 | On 32-bit x86-architecture systems, fast tracepoints normally need to |
11846 | be placed at an instruction that is 5 bytes or longer, but can be | |
11847 | placed at 4-byte instructions if the low 64K of memory of the target | |
11848 | program is available to install trampolines. Some Unix-type systems, | |
11849 | such as @sc{gnu}/Linux, exclude low addresses from the program's | |
11850 | address space; but for instance with the Linux kernel it is possible | |
11851 | to let @value{GDBN} use this area by doing a @command{sysctl} command | |
11852 | to set the @code{mmap_min_addr} kernel parameter, as in | |
11853 | ||
11854 | @example | |
11855 | sudo sysctl -w vm.mmap_min_addr=32768 | |
11856 | @end example | |
11857 | ||
11858 | @noindent | |
11859 | which sets the low address to 32K, which leaves plenty of room for | |
11860 | trampolines. The minimum address should be set to a page boundary. | |
11861 | ||
0fb4aa4b | 11862 | @item strace @var{location} [ if @var{cond} ] |
74c761c1 PA |
11863 | @cindex set static tracepoint |
11864 | @cindex static tracepoints, setting | |
11865 | @cindex probe static tracepoint marker | |
0fb4aa4b PA |
11866 | @kindex strace |
11867 | The @code{strace} command sets a static tracepoint. For targets that | |
11868 | support it, setting a static tracepoint probes a static | |
11869 | instrumentation point, or marker, found at @var{location}. It may not | |
11870 | be possible to set a static tracepoint at the desired location, in | |
11871 | which case the command will exit with an explanatory message. | |
11872 | ||
11873 | @value{GDBN} handles arguments to @code{strace} exactly as for | |
11874 | @code{trace}, with the addition that the user can also specify | |
11875 | @code{-m @var{marker}} as @var{location}. This probes the marker | |
11876 | identified by the @var{marker} string identifier. This identifier | |
11877 | depends on the static tracepoint backend library your program is | |
11878 | using. You can find all the marker identifiers in the @samp{ID} field | |
11879 | of the @code{info static-tracepoint-markers} command output. | |
11880 | @xref{Listing Static Tracepoint Markers,,Listing Static Tracepoint | |
11881 | Markers}. For example, in the following small program using the UST | |
11882 | tracing engine: | |
11883 | ||
11884 | @smallexample | |
11885 | main () | |
11886 | @{ | |
11887 | trace_mark(ust, bar33, "str %s", "FOOBAZ"); | |
11888 | @} | |
11889 | @end smallexample | |
11890 | ||
11891 | @noindent | |
11892 | the marker id is composed of joining the first two arguments to the | |
11893 | @code{trace_mark} call with a slash, which translates to: | |
11894 | ||
11895 | @smallexample | |
11896 | (@value{GDBP}) info static-tracepoint-markers | |
11897 | Cnt Enb ID Address What | |
11898 | 1 n ust/bar33 0x0000000000400ddc in main at stexample.c:22 | |
11899 | Data: "str %s" | |
11900 | [etc...] | |
11901 | @end smallexample | |
11902 | ||
11903 | @noindent | |
11904 | so you may probe the marker above with: | |
11905 | ||
11906 | @smallexample | |
11907 | (@value{GDBP}) strace -m ust/bar33 | |
11908 | @end smallexample | |
11909 | ||
11910 | Static tracepoints accept an extra collect action --- @code{collect | |
11911 | $_sdata}. This collects arbitrary user data passed in the probe point | |
11912 | call to the tracing library. In the UST example above, you'll see | |
11913 | that the third argument to @code{trace_mark} is a printf-like format | |
11914 | string. The user data is then the result of running that formating | |
11915 | string against the following arguments. Note that @code{info | |
11916 | static-tracepoint-markers} command output lists that format string in | |
11917 | the @samp{Data:} field. | |
11918 | ||
11919 | You can inspect this data when analyzing the trace buffer, by printing | |
11920 | the $_sdata variable like any other variable available to | |
11921 | @value{GDBN}. @xref{Tracepoint Actions,,Tracepoint Action Lists}. | |
11922 | ||
b37052ae EZ |
11923 | @vindex $tpnum |
11924 | @cindex last tracepoint number | |
11925 | @cindex recent tracepoint number | |
11926 | @cindex tracepoint number | |
11927 | The convenience variable @code{$tpnum} records the tracepoint number | |
11928 | of the most recently set tracepoint. | |
11929 | ||
11930 | @kindex delete tracepoint | |
11931 | @cindex tracepoint deletion | |
11932 | @item delete tracepoint @r{[}@var{num}@r{]} | |
11933 | Permanently delete one or more tracepoints. With no argument, the | |
1042e4c0 SS |
11934 | default is to delete all tracepoints. Note that the regular |
11935 | @code{delete} command can remove tracepoints also. | |
b37052ae EZ |
11936 | |
11937 | Examples: | |
11938 | ||
11939 | @smallexample | |
11940 | (@value{GDBP}) @b{delete trace 1 2 3} // remove three tracepoints | |
11941 | ||
11942 | (@value{GDBP}) @b{delete trace} // remove all tracepoints | |
11943 | @end smallexample | |
11944 | ||
11945 | @noindent | |
11946 | You can abbreviate this command as @code{del tr}. | |
11947 | @end table | |
11948 | ||
11949 | @node Enable and Disable Tracepoints | |
11950 | @subsection Enable and Disable Tracepoints | |
11951 | ||
1042e4c0 SS |
11952 | These commands are deprecated; they are equivalent to plain @code{disable} and @code{enable}. |
11953 | ||
b37052ae EZ |
11954 | @table @code |
11955 | @kindex disable tracepoint | |
11956 | @item disable tracepoint @r{[}@var{num}@r{]} | |
11957 | Disable tracepoint @var{num}, or all tracepoints if no argument | |
11958 | @var{num} is given. A disabled tracepoint will have no effect during | |
d248b706 | 11959 | a trace experiment, but it is not forgotten. You can re-enable |
b37052ae | 11960 | a disabled tracepoint using the @code{enable tracepoint} command. |
d248b706 KY |
11961 | If the command is issued during a trace experiment and the debug target |
11962 | has support for disabling tracepoints during a trace experiment, then the | |
11963 | change will be effective immediately. Otherwise, it will be applied to the | |
11964 | next trace experiment. | |
b37052ae EZ |
11965 | |
11966 | @kindex enable tracepoint | |
11967 | @item enable tracepoint @r{[}@var{num}@r{]} | |
d248b706 KY |
11968 | Enable tracepoint @var{num}, or all tracepoints. If this command is |
11969 | issued during a trace experiment and the debug target supports enabling | |
11970 | tracepoints during a trace experiment, then the enabled tracepoints will | |
11971 | become effective immediately. Otherwise, they will become effective the | |
11972 | next time a trace experiment is run. | |
b37052ae EZ |
11973 | @end table |
11974 | ||
11975 | @node Tracepoint Passcounts | |
11976 | @subsection Tracepoint Passcounts | |
11977 | ||
11978 | @table @code | |
11979 | @kindex passcount | |
11980 | @cindex tracepoint pass count | |
11981 | @item passcount @r{[}@var{n} @r{[}@var{num}@r{]]} | |
11982 | Set the @dfn{passcount} of a tracepoint. The passcount is a way to | |
11983 | automatically stop a trace experiment. If a tracepoint's passcount is | |
11984 | @var{n}, then the trace experiment will be automatically stopped on | |
11985 | the @var{n}'th time that tracepoint is hit. If the tracepoint number | |
11986 | @var{num} is not specified, the @code{passcount} command sets the | |
11987 | passcount of the most recently defined tracepoint. If no passcount is | |
11988 | given, the trace experiment will run until stopped explicitly by the | |
11989 | user. | |
11990 | ||
11991 | Examples: | |
11992 | ||
11993 | @smallexample | |
b383017d | 11994 | (@value{GDBP}) @b{passcount 5 2} // Stop on the 5th execution of |
6826cf00 | 11995 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// tracepoint 2} |
b37052ae EZ |
11996 | |
11997 | (@value{GDBP}) @b{passcount 12} // Stop on the 12th execution of the | |
6826cf00 | 11998 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// most recently defined tracepoint.} |
b37052ae EZ |
11999 | (@value{GDBP}) @b{trace foo} |
12000 | (@value{GDBP}) @b{pass 3} | |
12001 | (@value{GDBP}) @b{trace bar} | |
12002 | (@value{GDBP}) @b{pass 2} | |
12003 | (@value{GDBP}) @b{trace baz} | |
12004 | (@value{GDBP}) @b{pass 1} // Stop tracing when foo has been | |
6826cf00 EZ |
12005 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// executed 3 times OR when bar has} |
12006 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// been executed 2 times} | |
12007 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// OR when baz has been executed 1 time.} | |
b37052ae EZ |
12008 | @end smallexample |
12009 | @end table | |
12010 | ||
782b2b07 SS |
12011 | @node Tracepoint Conditions |
12012 | @subsection Tracepoint Conditions | |
12013 | @cindex conditional tracepoints | |
12014 | @cindex tracepoint conditions | |
12015 | ||
12016 | The simplest sort of tracepoint collects data every time your program | |
12017 | reaches a specified place. You can also specify a @dfn{condition} for | |
12018 | a tracepoint. A condition is just a Boolean expression in your | |
12019 | programming language (@pxref{Expressions, ,Expressions}). A | |
12020 | tracepoint with a condition evaluates the expression each time your | |
12021 | program reaches it, and data collection happens only if the condition | |
12022 | is true. | |
12023 | ||
12024 | Tracepoint conditions can be specified when a tracepoint is set, by | |
12025 | using @samp{if} in the arguments to the @code{trace} command. | |
12026 | @xref{Create and Delete Tracepoints, ,Setting Tracepoints}. They can | |
12027 | also be set or changed at any time with the @code{condition} command, | |
12028 | just as with breakpoints. | |
12029 | ||
12030 | Unlike breakpoint conditions, @value{GDBN} does not actually evaluate | |
12031 | the conditional expression itself. Instead, @value{GDBN} encodes the | |
6dcd5565 | 12032 | expression into an agent expression (@pxref{Agent Expressions}) |
782b2b07 SS |
12033 | suitable for execution on the target, independently of @value{GDBN}. |
12034 | Global variables become raw memory locations, locals become stack | |
12035 | accesses, and so forth. | |
12036 | ||
12037 | For instance, suppose you have a function that is usually called | |
12038 | frequently, but should not be called after an error has occurred. You | |
12039 | could use the following tracepoint command to collect data about calls | |
12040 | of that function that happen while the error code is propagating | |
12041 | through the program; an unconditional tracepoint could end up | |
12042 | collecting thousands of useless trace frames that you would have to | |
12043 | search through. | |
12044 | ||
12045 | @smallexample | |
12046 | (@value{GDBP}) @kbd{trace normal_operation if errcode > 0} | |
12047 | @end smallexample | |
12048 | ||
f61e138d SS |
12049 | @node Trace State Variables |
12050 | @subsection Trace State Variables | |
12051 | @cindex trace state variables | |
12052 | ||
12053 | A @dfn{trace state variable} is a special type of variable that is | |
12054 | created and managed by target-side code. The syntax is the same as | |
12055 | that for GDB's convenience variables (a string prefixed with ``$''), | |
12056 | but they are stored on the target. They must be created explicitly, | |
12057 | using a @code{tvariable} command. They are always 64-bit signed | |
12058 | integers. | |
12059 | ||
12060 | Trace state variables are remembered by @value{GDBN}, and downloaded | |
12061 | to the target along with tracepoint information when the trace | |
12062 | experiment starts. There are no intrinsic limits on the number of | |
12063 | trace state variables, beyond memory limitations of the target. | |
12064 | ||
12065 | @cindex convenience variables, and trace state variables | |
12066 | Although trace state variables are managed by the target, you can use | |
12067 | them in print commands and expressions as if they were convenience | |
12068 | variables; @value{GDBN} will get the current value from the target | |
12069 | while the trace experiment is running. Trace state variables share | |
12070 | the same namespace as other ``$'' variables, which means that you | |
12071 | cannot have trace state variables with names like @code{$23} or | |
12072 | @code{$pc}, nor can you have a trace state variable and a convenience | |
12073 | variable with the same name. | |
12074 | ||
12075 | @table @code | |
12076 | ||
12077 | @item tvariable $@var{name} [ = @var{expression} ] | |
12078 | @kindex tvariable | |
12079 | The @code{tvariable} command creates a new trace state variable named | |
12080 | @code{$@var{name}}, and optionally gives it an initial value of | |
697aa1b7 | 12081 | @var{expression}. The @var{expression} is evaluated when this command is |
f61e138d SS |
12082 | entered; the result will be converted to an integer if possible, |
12083 | otherwise @value{GDBN} will report an error. A subsequent | |
12084 | @code{tvariable} command specifying the same name does not create a | |
12085 | variable, but instead assigns the supplied initial value to the | |
12086 | existing variable of that name, overwriting any previous initial | |
12087 | value. The default initial value is 0. | |
12088 | ||
12089 | @item info tvariables | |
12090 | @kindex info tvariables | |
12091 | List all the trace state variables along with their initial values. | |
12092 | Their current values may also be displayed, if the trace experiment is | |
12093 | currently running. | |
12094 | ||
12095 | @item delete tvariable @r{[} $@var{name} @dots{} @r{]} | |
12096 | @kindex delete tvariable | |
12097 | Delete the given trace state variables, or all of them if no arguments | |
12098 | are specified. | |
12099 | ||
12100 | @end table | |
12101 | ||
b37052ae EZ |
12102 | @node Tracepoint Actions |
12103 | @subsection Tracepoint Action Lists | |
12104 | ||
12105 | @table @code | |
12106 | @kindex actions | |
12107 | @cindex tracepoint actions | |
12108 | @item actions @r{[}@var{num}@r{]} | |
12109 | This command will prompt for a list of actions to be taken when the | |
12110 | tracepoint is hit. If the tracepoint number @var{num} is not | |
12111 | specified, this command sets the actions for the one that was most | |
12112 | recently defined (so that you can define a tracepoint and then say | |
12113 | @code{actions} without bothering about its number). You specify the | |
12114 | actions themselves on the following lines, one action at a time, and | |
12115 | terminate the actions list with a line containing just @code{end}. So | |
7d13fe92 | 12116 | far, the only defined actions are @code{collect}, @code{teval}, and |
b37052ae EZ |
12117 | @code{while-stepping}. |
12118 | ||
5a9351ae SS |
12119 | @code{actions} is actually equivalent to @code{commands} (@pxref{Break |
12120 | Commands, ,Breakpoint Command Lists}), except that only the defined | |
12121 | actions are allowed; any other @value{GDBN} command is rejected. | |
12122 | ||
b37052ae EZ |
12123 | @cindex remove actions from a tracepoint |
12124 | To remove all actions from a tracepoint, type @samp{actions @var{num}} | |
12125 | and follow it immediately with @samp{end}. | |
12126 | ||
12127 | @smallexample | |
12128 | (@value{GDBP}) @b{collect @var{data}} // collect some data | |
12129 | ||
6826cf00 | 12130 | (@value{GDBP}) @b{while-stepping 5} // single-step 5 times, collect data |
b37052ae | 12131 | |
6826cf00 | 12132 | (@value{GDBP}) @b{end} // signals the end of actions. |
b37052ae EZ |
12133 | @end smallexample |
12134 | ||
12135 | In the following example, the action list begins with @code{collect} | |
12136 | commands indicating the things to be collected when the tracepoint is | |
12137 | hit. Then, in order to single-step and collect additional data | |
12138 | following the tracepoint, a @code{while-stepping} command is used, | |
7d13fe92 SS |
12139 | followed by the list of things to be collected after each step in a |
12140 | sequence of single steps. The @code{while-stepping} command is | |
12141 | terminated by its own separate @code{end} command. Lastly, the action | |
12142 | list is terminated by an @code{end} command. | |
b37052ae EZ |
12143 | |
12144 | @smallexample | |
12145 | (@value{GDBP}) @b{trace foo} | |
12146 | (@value{GDBP}) @b{actions} | |
12147 | Enter actions for tracepoint 1, one per line: | |
12148 | > collect bar,baz | |
12149 | > collect $regs | |
12150 | > while-stepping 12 | |
5a9351ae | 12151 | > collect $pc, arr[i] |
b37052ae EZ |
12152 | > end |
12153 | end | |
12154 | @end smallexample | |
12155 | ||
12156 | @kindex collect @r{(tracepoints)} | |
3065dfb6 | 12157 | @item collect@r{[}/@var{mods}@r{]} @var{expr1}, @var{expr2}, @dots{} |
b37052ae EZ |
12158 | Collect values of the given expressions when the tracepoint is hit. |
12159 | This command accepts a comma-separated list of any valid expressions. | |
12160 | In addition to global, static, or local variables, the following | |
12161 | special arguments are supported: | |
12162 | ||
12163 | @table @code | |
12164 | @item $regs | |
0fb4aa4b | 12165 | Collect all registers. |
b37052ae EZ |
12166 | |
12167 | @item $args | |
0fb4aa4b | 12168 | Collect all function arguments. |
b37052ae EZ |
12169 | |
12170 | @item $locals | |
0fb4aa4b PA |
12171 | Collect all local variables. |
12172 | ||
6710bf39 SS |
12173 | @item $_ret |
12174 | Collect the return address. This is helpful if you want to see more | |
12175 | of a backtrace. | |
12176 | ||
62e5f89c SDJ |
12177 | @item $_probe_argc |
12178 | Collects the number of arguments from the static probe at which the | |
12179 | tracepoint is located. | |
12180 | @xref{Static Probe Points}. | |
12181 | ||
12182 | @item $_probe_arg@var{n} | |
12183 | @var{n} is an integer between 0 and 11. Collects the @var{n}th argument | |
12184 | from the static probe at which the tracepoint is located. | |
12185 | @xref{Static Probe Points}. | |
12186 | ||
0fb4aa4b PA |
12187 | @item $_sdata |
12188 | @vindex $_sdata@r{, collect} | |
12189 | Collect static tracepoint marker specific data. Only available for | |
12190 | static tracepoints. @xref{Tracepoint Actions,,Tracepoint Action | |
12191 | Lists}. On the UST static tracepoints library backend, an | |
12192 | instrumentation point resembles a @code{printf} function call. The | |
12193 | tracing library is able to collect user specified data formatted to a | |
12194 | character string using the format provided by the programmer that | |
12195 | instrumented the program. Other backends have similar mechanisms. | |
12196 | Here's an example of a UST marker call: | |
12197 | ||
12198 | @smallexample | |
12199 | const char master_name[] = "$your_name"; | |
12200 | trace_mark(channel1, marker1, "hello %s", master_name) | |
12201 | @end smallexample | |
12202 | ||
12203 | In this case, collecting @code{$_sdata} collects the string | |
12204 | @samp{hello $yourname}. When analyzing the trace buffer, you can | |
12205 | inspect @samp{$_sdata} like any other variable available to | |
12206 | @value{GDBN}. | |
b37052ae EZ |
12207 | @end table |
12208 | ||
12209 | You can give several consecutive @code{collect} commands, each one | |
12210 | with a single argument, or one @code{collect} command with several | |
5a9351ae | 12211 | arguments separated by commas; the effect is the same. |
b37052ae | 12212 | |
3065dfb6 SS |
12213 | The optional @var{mods} changes the usual handling of the arguments. |
12214 | @code{s} requests that pointers to chars be handled as strings, in | |
12215 | particular collecting the contents of the memory being pointed at, up | |
12216 | to the first zero. The upper bound is by default the value of the | |
12217 | @code{print elements} variable; if @code{s} is followed by a decimal | |
12218 | number, that is the upper bound instead. So for instance | |
12219 | @samp{collect/s25 mystr} collects as many as 25 characters at | |
12220 | @samp{mystr}. | |
12221 | ||
f5c37c66 EZ |
12222 | The command @code{info scope} (@pxref{Symbols, info scope}) is |
12223 | particularly useful for figuring out what data to collect. | |
12224 | ||
6da95a67 SS |
12225 | @kindex teval @r{(tracepoints)} |
12226 | @item teval @var{expr1}, @var{expr2}, @dots{} | |
12227 | Evaluate the given expressions when the tracepoint is hit. This | |
12228 | command accepts a comma-separated list of expressions. The results | |
12229 | are discarded, so this is mainly useful for assigning values to trace | |
12230 | state variables (@pxref{Trace State Variables}) without adding those | |
12231 | values to the trace buffer, as would be the case if the @code{collect} | |
12232 | action were used. | |
12233 | ||
b37052ae EZ |
12234 | @kindex while-stepping @r{(tracepoints)} |
12235 | @item while-stepping @var{n} | |
c9429232 | 12236 | Perform @var{n} single-step instruction traces after the tracepoint, |
7d13fe92 | 12237 | collecting new data after each step. The @code{while-stepping} |
c9429232 SS |
12238 | command is followed by the list of what to collect while stepping |
12239 | (followed by its own @code{end} command): | |
b37052ae EZ |
12240 | |
12241 | @smallexample | |
12242 | > while-stepping 12 | |
12243 | > collect $regs, myglobal | |
12244 | > end | |
12245 | > | |
12246 | @end smallexample | |
12247 | ||
12248 | @noindent | |
7d13fe92 SS |
12249 | Note that @code{$pc} is not automatically collected by |
12250 | @code{while-stepping}; you need to explicitly collect that register if | |
12251 | you need it. You may abbreviate @code{while-stepping} as @code{ws} or | |
b37052ae | 12252 | @code{stepping}. |
236f1d4d SS |
12253 | |
12254 | @item set default-collect @var{expr1}, @var{expr2}, @dots{} | |
12255 | @kindex set default-collect | |
12256 | @cindex default collection action | |
12257 | This variable is a list of expressions to collect at each tracepoint | |
12258 | hit. It is effectively an additional @code{collect} action prepended | |
12259 | to every tracepoint action list. The expressions are parsed | |
12260 | individually for each tracepoint, so for instance a variable named | |
12261 | @code{xyz} may be interpreted as a global for one tracepoint, and a | |
12262 | local for another, as appropriate to the tracepoint's location. | |
12263 | ||
12264 | @item show default-collect | |
12265 | @kindex show default-collect | |
12266 | Show the list of expressions that are collected by default at each | |
12267 | tracepoint hit. | |
12268 | ||
b37052ae EZ |
12269 | @end table |
12270 | ||
12271 | @node Listing Tracepoints | |
12272 | @subsection Listing Tracepoints | |
12273 | ||
12274 | @table @code | |
e5a67952 MS |
12275 | @kindex info tracepoints @r{[}@var{n}@dots{}@r{]} |
12276 | @kindex info tp @r{[}@var{n}@dots{}@r{]} | |
b37052ae | 12277 | @cindex information about tracepoints |
e5a67952 | 12278 | @item info tracepoints @r{[}@var{num}@dots{}@r{]} |
1042e4c0 SS |
12279 | Display information about the tracepoint @var{num}. If you don't |
12280 | specify a tracepoint number, displays information about all the | |
12281 | tracepoints defined so far. The format is similar to that used for | |
12282 | @code{info breakpoints}; in fact, @code{info tracepoints} is the same | |
12283 | command, simply restricting itself to tracepoints. | |
12284 | ||
12285 | A tracepoint's listing may include additional information specific to | |
12286 | tracing: | |
b37052ae EZ |
12287 | |
12288 | @itemize @bullet | |
12289 | @item | |
b37052ae | 12290 | its passcount as given by the @code{passcount @var{n}} command |
f2a8bc8a YQ |
12291 | |
12292 | @item | |
12293 | the state about installed on target of each location | |
b37052ae EZ |
12294 | @end itemize |
12295 | ||
12296 | @smallexample | |
12297 | (@value{GDBP}) @b{info trace} | |
1042e4c0 SS |
12298 | Num Type Disp Enb Address What |
12299 | 1 tracepoint keep y 0x0804ab57 in foo() at main.cxx:7 | |
5a9351ae SS |
12300 | while-stepping 20 |
12301 | collect globfoo, $regs | |
12302 | end | |
12303 | collect globfoo2 | |
12304 | end | |
1042e4c0 | 12305 | pass count 1200 |
f2a8bc8a YQ |
12306 | 2 tracepoint keep y <MULTIPLE> |
12307 | collect $eip | |
12308 | 2.1 y 0x0804859c in func4 at change-loc.h:35 | |
12309 | installed on target | |
12310 | 2.2 y 0xb7ffc480 in func4 at change-loc.h:35 | |
12311 | installed on target | |
12312 | 2.3 y <PENDING> set_tracepoint | |
12313 | 3 tracepoint keep y 0x080485b1 in foo at change-loc.c:29 | |
12314 | not installed on target | |
b37052ae EZ |
12315 | (@value{GDBP}) |
12316 | @end smallexample | |
12317 | ||
12318 | @noindent | |
12319 | This command can be abbreviated @code{info tp}. | |
12320 | @end table | |
12321 | ||
0fb4aa4b PA |
12322 | @node Listing Static Tracepoint Markers |
12323 | @subsection Listing Static Tracepoint Markers | |
12324 | ||
12325 | @table @code | |
12326 | @kindex info static-tracepoint-markers | |
12327 | @cindex information about static tracepoint markers | |
12328 | @item info static-tracepoint-markers | |
12329 | Display information about all static tracepoint markers defined in the | |
12330 | program. | |
12331 | ||
12332 | For each marker, the following columns are printed: | |
12333 | ||
12334 | @table @emph | |
12335 | @item Count | |
12336 | An incrementing counter, output to help readability. This is not a | |
12337 | stable identifier. | |
12338 | @item ID | |
12339 | The marker ID, as reported by the target. | |
12340 | @item Enabled or Disabled | |
12341 | Probed markers are tagged with @samp{y}. @samp{n} identifies marks | |
12342 | that are not enabled. | |
12343 | @item Address | |
12344 | Where the marker is in your program, as a memory address. | |
12345 | @item What | |
12346 | Where the marker is in the source for your program, as a file and line | |
12347 | number. If the debug information included in the program does not | |
12348 | allow @value{GDBN} to locate the source of the marker, this column | |
12349 | will be left blank. | |
12350 | @end table | |
12351 | ||
12352 | @noindent | |
12353 | In addition, the following information may be printed for each marker: | |
12354 | ||
12355 | @table @emph | |
12356 | @item Data | |
12357 | User data passed to the tracing library by the marker call. In the | |
12358 | UST backend, this is the format string passed as argument to the | |
12359 | marker call. | |
12360 | @item Static tracepoints probing the marker | |
12361 | The list of static tracepoints attached to the marker. | |
12362 | @end table | |
12363 | ||
12364 | @smallexample | |
12365 | (@value{GDBP}) info static-tracepoint-markers | |
12366 | Cnt ID Enb Address What | |
12367 | 1 ust/bar2 y 0x0000000000400e1a in main at stexample.c:25 | |
12368 | Data: number1 %d number2 %d | |
12369 | Probed by static tracepoints: #2 | |
12370 | 2 ust/bar33 n 0x0000000000400c87 in main at stexample.c:24 | |
12371 | Data: str %s | |
12372 | (@value{GDBP}) | |
12373 | @end smallexample | |
12374 | @end table | |
12375 | ||
79a6e687 BW |
12376 | @node Starting and Stopping Trace Experiments |
12377 | @subsection Starting and Stopping Trace Experiments | |
b37052ae EZ |
12378 | |
12379 | @table @code | |
f196051f | 12380 | @kindex tstart [ @var{notes} ] |
b37052ae EZ |
12381 | @cindex start a new trace experiment |
12382 | @cindex collected data discarded | |
12383 | @item tstart | |
f196051f SS |
12384 | This command starts the trace experiment, and begins collecting data. |
12385 | It has the side effect of discarding all the data collected in the | |
12386 | trace buffer during the previous trace experiment. If any arguments | |
12387 | are supplied, they are taken as a note and stored with the trace | |
12388 | experiment's state. The notes may be arbitrary text, and are | |
12389 | especially useful with disconnected tracing in a multi-user context; | |
12390 | the notes can explain what the trace is doing, supply user contact | |
12391 | information, and so forth. | |
12392 | ||
12393 | @kindex tstop [ @var{notes} ] | |
b37052ae EZ |
12394 | @cindex stop a running trace experiment |
12395 | @item tstop | |
f196051f SS |
12396 | This command stops the trace experiment. If any arguments are |
12397 | supplied, they are recorded with the experiment as a note. This is | |
12398 | useful if you are stopping a trace started by someone else, for | |
12399 | instance if the trace is interfering with the system's behavior and | |
12400 | needs to be stopped quickly. | |
b37052ae | 12401 | |
68c71a2e | 12402 | @strong{Note}: a trace experiment and data collection may stop |
b37052ae EZ |
12403 | automatically if any tracepoint's passcount is reached |
12404 | (@pxref{Tracepoint Passcounts}), or if the trace buffer becomes full. | |
12405 | ||
12406 | @kindex tstatus | |
12407 | @cindex status of trace data collection | |
12408 | @cindex trace experiment, status of | |
12409 | @item tstatus | |
12410 | This command displays the status of the current trace data | |
12411 | collection. | |
12412 | @end table | |
12413 | ||
12414 | Here is an example of the commands we described so far: | |
12415 | ||
12416 | @smallexample | |
12417 | (@value{GDBP}) @b{trace gdb_c_test} | |
12418 | (@value{GDBP}) @b{actions} | |
12419 | Enter actions for tracepoint #1, one per line. | |
12420 | > collect $regs,$locals,$args | |
12421 | > while-stepping 11 | |
12422 | > collect $regs | |
12423 | > end | |
12424 | > end | |
12425 | (@value{GDBP}) @b{tstart} | |
12426 | [time passes @dots{}] | |
12427 | (@value{GDBP}) @b{tstop} | |
12428 | @end smallexample | |
12429 | ||
03f2bd59 | 12430 | @anchor{disconnected tracing} |
d5551862 SS |
12431 | @cindex disconnected tracing |
12432 | You can choose to continue running the trace experiment even if | |
12433 | @value{GDBN} disconnects from the target, voluntarily or | |
12434 | involuntarily. For commands such as @code{detach}, the debugger will | |
12435 | ask what you want to do with the trace. But for unexpected | |
12436 | terminations (@value{GDBN} crash, network outage), it would be | |
12437 | unfortunate to lose hard-won trace data, so the variable | |
12438 | @code{disconnected-tracing} lets you decide whether the trace should | |
12439 | continue running without @value{GDBN}. | |
12440 | ||
12441 | @table @code | |
12442 | @item set disconnected-tracing on | |
12443 | @itemx set disconnected-tracing off | |
12444 | @kindex set disconnected-tracing | |
12445 | Choose whether a tracing run should continue to run if @value{GDBN} | |
12446 | has disconnected from the target. Note that @code{detach} or | |
12447 | @code{quit} will ask you directly what to do about a running trace no | |
12448 | matter what this variable's setting, so the variable is mainly useful | |
12449 | for handling unexpected situations, such as loss of the network. | |
12450 | ||
12451 | @item show disconnected-tracing | |
12452 | @kindex show disconnected-tracing | |
12453 | Show the current choice for disconnected tracing. | |
12454 | ||
12455 | @end table | |
12456 | ||
12457 | When you reconnect to the target, the trace experiment may or may not | |
12458 | still be running; it might have filled the trace buffer in the | |
12459 | meantime, or stopped for one of the other reasons. If it is running, | |
12460 | it will continue after reconnection. | |
12461 | ||
12462 | Upon reconnection, the target will upload information about the | |
12463 | tracepoints in effect. @value{GDBN} will then compare that | |
12464 | information to the set of tracepoints currently defined, and attempt | |
12465 | to match them up, allowing for the possibility that the numbers may | |
12466 | have changed due to creation and deletion in the meantime. If one of | |
12467 | the target's tracepoints does not match any in @value{GDBN}, the | |
12468 | debugger will create a new tracepoint, so that you have a number with | |
12469 | which to specify that tracepoint. This matching-up process is | |
12470 | necessarily heuristic, and it may result in useless tracepoints being | |
12471 | created; you may simply delete them if they are of no use. | |
b37052ae | 12472 | |
4daf5ac0 SS |
12473 | @cindex circular trace buffer |
12474 | If your target agent supports a @dfn{circular trace buffer}, then you | |
12475 | can run a trace experiment indefinitely without filling the trace | |
12476 | buffer; when space runs out, the agent deletes already-collected trace | |
12477 | frames, oldest first, until there is enough room to continue | |
12478 | collecting. This is especially useful if your tracepoints are being | |
12479 | hit too often, and your trace gets terminated prematurely because the | |
12480 | buffer is full. To ask for a circular trace buffer, simply set | |
81896e36 | 12481 | @samp{circular-trace-buffer} to on. You can set this at any time, |
4daf5ac0 SS |
12482 | including during tracing; if the agent can do it, it will change |
12483 | buffer handling on the fly, otherwise it will not take effect until | |
12484 | the next run. | |
12485 | ||
12486 | @table @code | |
12487 | @item set circular-trace-buffer on | |
12488 | @itemx set circular-trace-buffer off | |
12489 | @kindex set circular-trace-buffer | |
12490 | Choose whether a tracing run should use a linear or circular buffer | |
12491 | for trace data. A linear buffer will not lose any trace data, but may | |
12492 | fill up prematurely, while a circular buffer will discard old trace | |
12493 | data, but it will have always room for the latest tracepoint hits. | |
12494 | ||
12495 | @item show circular-trace-buffer | |
12496 | @kindex show circular-trace-buffer | |
12497 | Show the current choice for the trace buffer. Note that this may not | |
12498 | match the agent's current buffer handling, nor is it guaranteed to | |
12499 | match the setting that might have been in effect during a past run, | |
12500 | for instance if you are looking at frames from a trace file. | |
12501 | ||
12502 | @end table | |
12503 | ||
f6f899bf HAQ |
12504 | @table @code |
12505 | @item set trace-buffer-size @var{n} | |
f81d1120 | 12506 | @itemx set trace-buffer-size unlimited |
f6f899bf HAQ |
12507 | @kindex set trace-buffer-size |
12508 | Request that the target use a trace buffer of @var{n} bytes. Not all | |
12509 | targets will honor the request; they may have a compiled-in size for | |
12510 | the trace buffer, or some other limitation. Set to a value of | |
f81d1120 PA |
12511 | @code{unlimited} or @code{-1} to let the target use whatever size it |
12512 | likes. This is also the default. | |
f6f899bf HAQ |
12513 | |
12514 | @item show trace-buffer-size | |
12515 | @kindex show trace-buffer-size | |
12516 | Show the current requested size for the trace buffer. Note that this | |
12517 | will only match the actual size if the target supports size-setting, | |
12518 | and was able to handle the requested size. For instance, if the | |
12519 | target can only change buffer size between runs, this variable will | |
12520 | not reflect the change until the next run starts. Use @code{tstatus} | |
12521 | to get a report of the actual buffer size. | |
12522 | @end table | |
12523 | ||
f196051f SS |
12524 | @table @code |
12525 | @item set trace-user @var{text} | |
12526 | @kindex set trace-user | |
12527 | ||
12528 | @item show trace-user | |
12529 | @kindex show trace-user | |
12530 | ||
12531 | @item set trace-notes @var{text} | |
12532 | @kindex set trace-notes | |
12533 | Set the trace run's notes. | |
12534 | ||
12535 | @item show trace-notes | |
12536 | @kindex show trace-notes | |
12537 | Show the trace run's notes. | |
12538 | ||
12539 | @item set trace-stop-notes @var{text} | |
12540 | @kindex set trace-stop-notes | |
12541 | Set the trace run's stop notes. The handling of the note is as for | |
12542 | @code{tstop} arguments; the set command is convenient way to fix a | |
12543 | stop note that is mistaken or incomplete. | |
12544 | ||
12545 | @item show trace-stop-notes | |
12546 | @kindex show trace-stop-notes | |
12547 | Show the trace run's stop notes. | |
12548 | ||
12549 | @end table | |
12550 | ||
c9429232 SS |
12551 | @node Tracepoint Restrictions |
12552 | @subsection Tracepoint Restrictions | |
12553 | ||
12554 | @cindex tracepoint restrictions | |
12555 | There are a number of restrictions on the use of tracepoints. As | |
12556 | described above, tracepoint data gathering occurs on the target | |
12557 | without interaction from @value{GDBN}. Thus the full capabilities of | |
12558 | the debugger are not available during data gathering, and then at data | |
12559 | examination time, you will be limited by only having what was | |
12560 | collected. The following items describe some common problems, but it | |
12561 | is not exhaustive, and you may run into additional difficulties not | |
12562 | mentioned here. | |
12563 | ||
12564 | @itemize @bullet | |
12565 | ||
12566 | @item | |
12567 | Tracepoint expressions are intended to gather objects (lvalues). Thus | |
12568 | the full flexibility of GDB's expression evaluator is not available. | |
12569 | You cannot call functions, cast objects to aggregate types, access | |
12570 | convenience variables or modify values (except by assignment to trace | |
12571 | state variables). Some language features may implicitly call | |
12572 | functions (for instance Objective-C fields with accessors), and therefore | |
12573 | cannot be collected either. | |
12574 | ||
12575 | @item | |
12576 | Collection of local variables, either individually or in bulk with | |
12577 | @code{$locals} or @code{$args}, during @code{while-stepping} may | |
12578 | behave erratically. The stepping action may enter a new scope (for | |
12579 | instance by stepping into a function), or the location of the variable | |
12580 | may change (for instance it is loaded into a register). The | |
12581 | tracepoint data recorded uses the location information for the | |
12582 | variables that is correct for the tracepoint location. When the | |
12583 | tracepoint is created, it is not possible, in general, to determine | |
12584 | where the steps of a @code{while-stepping} sequence will advance the | |
12585 | program---particularly if a conditional branch is stepped. | |
12586 | ||
12587 | @item | |
12588 | Collection of an incompletely-initialized or partially-destroyed object | |
12589 | may result in something that @value{GDBN} cannot display, or displays | |
12590 | in a misleading way. | |
12591 | ||
12592 | @item | |
12593 | When @value{GDBN} displays a pointer to character it automatically | |
12594 | dereferences the pointer to also display characters of the string | |
12595 | being pointed to. However, collecting the pointer during tracing does | |
12596 | not automatically collect the string. You need to explicitly | |
12597 | dereference the pointer and provide size information if you want to | |
12598 | collect not only the pointer, but the memory pointed to. For example, | |
12599 | @code{*ptr@@50} can be used to collect the 50 element array pointed to | |
12600 | by @code{ptr}. | |
12601 | ||
12602 | @item | |
12603 | It is not possible to collect a complete stack backtrace at a | |
12604 | tracepoint. Instead, you may collect the registers and a few hundred | |
d99f7e48 | 12605 | bytes from the stack pointer with something like @code{*(unsigned char *)$esp@@300} |
c9429232 SS |
12606 | (adjust to use the name of the actual stack pointer register on your |
12607 | target architecture, and the amount of stack you wish to capture). | |
12608 | Then the @code{backtrace} command will show a partial backtrace when | |
12609 | using a trace frame. The number of stack frames that can be examined | |
12610 | depends on the sizes of the frames in the collected stack. Note that | |
12611 | if you ask for a block so large that it goes past the bottom of the | |
12612 | stack, the target agent may report an error trying to read from an | |
12613 | invalid address. | |
12614 | ||
af54718e SS |
12615 | @item |
12616 | If you do not collect registers at a tracepoint, @value{GDBN} can | |
12617 | infer that the value of @code{$pc} must be the same as the address of | |
12618 | the tracepoint and use that when you are looking at a trace frame | |
12619 | for that tracepoint. However, this cannot work if the tracepoint has | |
12620 | multiple locations (for instance if it was set in a function that was | |
12621 | inlined), or if it has a @code{while-stepping} loop. In those cases | |
12622 | @value{GDBN} will warn you that it can't infer @code{$pc}, and default | |
12623 | it to zero. | |
12624 | ||
c9429232 SS |
12625 | @end itemize |
12626 | ||
b37052ae | 12627 | @node Analyze Collected Data |
79a6e687 | 12628 | @section Using the Collected Data |
b37052ae EZ |
12629 | |
12630 | After the tracepoint experiment ends, you use @value{GDBN} commands | |
12631 | for examining the trace data. The basic idea is that each tracepoint | |
12632 | collects a trace @dfn{snapshot} every time it is hit and another | |
12633 | snapshot every time it single-steps. All these snapshots are | |
12634 | consecutively numbered from zero and go into a buffer, and you can | |
12635 | examine them later. The way you examine them is to @dfn{focus} on a | |
12636 | specific trace snapshot. When the remote stub is focused on a trace | |
12637 | snapshot, it will respond to all @value{GDBN} requests for memory and | |
12638 | registers by reading from the buffer which belongs to that snapshot, | |
12639 | rather than from @emph{real} memory or registers of the program being | |
12640 | debugged. This means that @strong{all} @value{GDBN} commands | |
12641 | (@code{print}, @code{info registers}, @code{backtrace}, etc.) will | |
12642 | behave as if we were currently debugging the program state as it was | |
12643 | when the tracepoint occurred. Any requests for data that are not in | |
12644 | the buffer will fail. | |
12645 | ||
12646 | @menu | |
12647 | * tfind:: How to select a trace snapshot | |
12648 | * tdump:: How to display all data for a snapshot | |
6149aea9 | 12649 | * save tracepoints:: How to save tracepoints for a future run |
b37052ae EZ |
12650 | @end menu |
12651 | ||
12652 | @node tfind | |
12653 | @subsection @code{tfind @var{n}} | |
12654 | ||
12655 | @kindex tfind | |
12656 | @cindex select trace snapshot | |
12657 | @cindex find trace snapshot | |
12658 | The basic command for selecting a trace snapshot from the buffer is | |
12659 | @code{tfind @var{n}}, which finds trace snapshot number @var{n}, | |
12660 | counting from zero. If no argument @var{n} is given, the next | |
12661 | snapshot is selected. | |
12662 | ||
12663 | Here are the various forms of using the @code{tfind} command. | |
12664 | ||
12665 | @table @code | |
12666 | @item tfind start | |
12667 | Find the first snapshot in the buffer. This is a synonym for | |
12668 | @code{tfind 0} (since 0 is the number of the first snapshot). | |
12669 | ||
12670 | @item tfind none | |
12671 | Stop debugging trace snapshots, resume @emph{live} debugging. | |
12672 | ||
12673 | @item tfind end | |
12674 | Same as @samp{tfind none}. | |
12675 | ||
12676 | @item tfind | |
12677 | No argument means find the next trace snapshot. | |
12678 | ||
12679 | @item tfind - | |
12680 | Find the previous trace snapshot before the current one. This permits | |
12681 | retracing earlier steps. | |
12682 | ||
12683 | @item tfind tracepoint @var{num} | |
12684 | Find the next snapshot associated with tracepoint @var{num}. Search | |
12685 | proceeds forward from the last examined trace snapshot. If no | |
12686 | argument @var{num} is given, it means find the next snapshot collected | |
12687 | for the same tracepoint as the current snapshot. | |
12688 | ||
12689 | @item tfind pc @var{addr} | |
12690 | Find the next snapshot associated with the value @var{addr} of the | |
12691 | program counter. Search proceeds forward from the last examined trace | |
12692 | snapshot. If no argument @var{addr} is given, it means find the next | |
12693 | snapshot with the same value of PC as the current snapshot. | |
12694 | ||
12695 | @item tfind outside @var{addr1}, @var{addr2} | |
12696 | Find the next snapshot whose PC is outside the given range of | |
081dfbf7 | 12697 | addresses (exclusive). |
b37052ae EZ |
12698 | |
12699 | @item tfind range @var{addr1}, @var{addr2} | |
12700 | Find the next snapshot whose PC is between @var{addr1} and | |
081dfbf7 | 12701 | @var{addr2} (inclusive). |
b37052ae EZ |
12702 | |
12703 | @item tfind line @r{[}@var{file}:@r{]}@var{n} | |
12704 | Find the next snapshot associated with the source line @var{n}. If | |
12705 | the optional argument @var{file} is given, refer to line @var{n} in | |
12706 | that source file. Search proceeds forward from the last examined | |
12707 | trace snapshot. If no argument @var{n} is given, it means find the | |
12708 | next line other than the one currently being examined; thus saying | |
12709 | @code{tfind line} repeatedly can appear to have the same effect as | |
12710 | stepping from line to line in a @emph{live} debugging session. | |
12711 | @end table | |
12712 | ||
12713 | The default arguments for the @code{tfind} commands are specifically | |
12714 | designed to make it easy to scan through the trace buffer. For | |
12715 | instance, @code{tfind} with no argument selects the next trace | |
12716 | snapshot, and @code{tfind -} with no argument selects the previous | |
12717 | trace snapshot. So, by giving one @code{tfind} command, and then | |
12718 | simply hitting @key{RET} repeatedly you can examine all the trace | |
12719 | snapshots in order. Or, by saying @code{tfind -} and then hitting | |
12720 | @key{RET} repeatedly you can examine the snapshots in reverse order. | |
12721 | The @code{tfind line} command with no argument selects the snapshot | |
12722 | for the next source line executed. The @code{tfind pc} command with | |
12723 | no argument selects the next snapshot with the same program counter | |
12724 | (PC) as the current frame. The @code{tfind tracepoint} command with | |
12725 | no argument selects the next trace snapshot collected by the same | |
12726 | tracepoint as the current one. | |
12727 | ||
12728 | In addition to letting you scan through the trace buffer manually, | |
12729 | these commands make it easy to construct @value{GDBN} scripts that | |
12730 | scan through the trace buffer and print out whatever collected data | |
12731 | you are interested in. Thus, if we want to examine the PC, FP, and SP | |
12732 | registers from each trace frame in the buffer, we can say this: | |
12733 | ||
12734 | @smallexample | |
12735 | (@value{GDBP}) @b{tfind start} | |
12736 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
12737 | > printf "Frame %d, PC = %08X, SP = %08X, FP = %08X\n", \ | |
12738 | $trace_frame, $pc, $sp, $fp | |
12739 | > tfind | |
12740 | > end | |
12741 | ||
12742 | Frame 0, PC = 0020DC64, SP = 0030BF3C, FP = 0030BF44 | |
12743 | Frame 1, PC = 0020DC6C, SP = 0030BF38, FP = 0030BF44 | |
12744 | Frame 2, PC = 0020DC70, SP = 0030BF34, FP = 0030BF44 | |
12745 | Frame 3, PC = 0020DC74, SP = 0030BF30, FP = 0030BF44 | |
12746 | Frame 4, PC = 0020DC78, SP = 0030BF2C, FP = 0030BF44 | |
12747 | Frame 5, PC = 0020DC7C, SP = 0030BF28, FP = 0030BF44 | |
12748 | Frame 6, PC = 0020DC80, SP = 0030BF24, FP = 0030BF44 | |
12749 | Frame 7, PC = 0020DC84, SP = 0030BF20, FP = 0030BF44 | |
12750 | Frame 8, PC = 0020DC88, SP = 0030BF1C, FP = 0030BF44 | |
12751 | Frame 9, PC = 0020DC8E, SP = 0030BF18, FP = 0030BF44 | |
12752 | Frame 10, PC = 00203F6C, SP = 0030BE3C, FP = 0030BF14 | |
12753 | @end smallexample | |
12754 | ||
12755 | Or, if we want to examine the variable @code{X} at each source line in | |
12756 | the buffer: | |
12757 | ||
12758 | @smallexample | |
12759 | (@value{GDBP}) @b{tfind start} | |
12760 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
12761 | > printf "Frame %d, X == %d\n", $trace_frame, X | |
12762 | > tfind line | |
12763 | > end | |
12764 | ||
12765 | Frame 0, X = 1 | |
12766 | Frame 7, X = 2 | |
12767 | Frame 13, X = 255 | |
12768 | @end smallexample | |
12769 | ||
12770 | @node tdump | |
12771 | @subsection @code{tdump} | |
12772 | @kindex tdump | |
12773 | @cindex dump all data collected at tracepoint | |
12774 | @cindex tracepoint data, display | |
12775 | ||
12776 | This command takes no arguments. It prints all the data collected at | |
12777 | the current trace snapshot. | |
12778 | ||
12779 | @smallexample | |
12780 | (@value{GDBP}) @b{trace 444} | |
12781 | (@value{GDBP}) @b{actions} | |
12782 | Enter actions for tracepoint #2, one per line: | |
12783 | > collect $regs, $locals, $args, gdb_long_test | |
12784 | > end | |
12785 | ||
12786 | (@value{GDBP}) @b{tstart} | |
12787 | ||
12788 | (@value{GDBP}) @b{tfind line 444} | |
12789 | #0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66) | |
12790 | at gdb_test.c:444 | |
12791 | 444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ) | |
12792 | ||
12793 | (@value{GDBP}) @b{tdump} | |
12794 | Data collected at tracepoint 2, trace frame 1: | |
12795 | d0 0xc4aa0085 -995491707 | |
12796 | d1 0x18 24 | |
12797 | d2 0x80 128 | |
12798 | d3 0x33 51 | |
12799 | d4 0x71aea3d 119204413 | |
12800 | d5 0x22 34 | |
12801 | d6 0xe0 224 | |
12802 | d7 0x380035 3670069 | |
12803 | a0 0x19e24a 1696330 | |
12804 | a1 0x3000668 50333288 | |
12805 | a2 0x100 256 | |
12806 | a3 0x322000 3284992 | |
12807 | a4 0x3000698 50333336 | |
12808 | a5 0x1ad3cc 1758156 | |
12809 | fp 0x30bf3c 0x30bf3c | |
12810 | sp 0x30bf34 0x30bf34 | |
12811 | ps 0x0 0 | |
12812 | pc 0x20b2c8 0x20b2c8 | |
12813 | fpcontrol 0x0 0 | |
12814 | fpstatus 0x0 0 | |
12815 | fpiaddr 0x0 0 | |
12816 | p = 0x20e5b4 "gdb-test" | |
12817 | p1 = (void *) 0x11 | |
12818 | p2 = (void *) 0x22 | |
12819 | p3 = (void *) 0x33 | |
12820 | p4 = (void *) 0x44 | |
12821 | p5 = (void *) 0x55 | |
12822 | p6 = (void *) 0x66 | |
12823 | gdb_long_test = 17 '\021' | |
12824 | ||
12825 | (@value{GDBP}) | |
12826 | @end smallexample | |
12827 | ||
af54718e SS |
12828 | @code{tdump} works by scanning the tracepoint's current collection |
12829 | actions and printing the value of each expression listed. So | |
12830 | @code{tdump} can fail, if after a run, you change the tracepoint's | |
12831 | actions to mention variables that were not collected during the run. | |
12832 | ||
12833 | Also, for tracepoints with @code{while-stepping} loops, @code{tdump} | |
12834 | uses the collected value of @code{$pc} to distinguish between trace | |
12835 | frames that were collected at the tracepoint hit, and frames that were | |
12836 | collected while stepping. This allows it to correctly choose whether | |
12837 | to display the basic list of collections, or the collections from the | |
12838 | body of the while-stepping loop. However, if @code{$pc} was not collected, | |
12839 | then @code{tdump} will always attempt to dump using the basic collection | |
12840 | list, and may fail if a while-stepping frame does not include all the | |
12841 | same data that is collected at the tracepoint hit. | |
12842 | @c This is getting pretty arcane, example would be good. | |
12843 | ||
6149aea9 PA |
12844 | @node save tracepoints |
12845 | @subsection @code{save tracepoints @var{filename}} | |
12846 | @kindex save tracepoints | |
b37052ae EZ |
12847 | @kindex save-tracepoints |
12848 | @cindex save tracepoints for future sessions | |
12849 | ||
12850 | This command saves all current tracepoint definitions together with | |
12851 | their actions and passcounts, into a file @file{@var{filename}} | |
12852 | suitable for use in a later debugging session. To read the saved | |
12853 | tracepoint definitions, use the @code{source} command (@pxref{Command | |
6149aea9 PA |
12854 | Files}). The @w{@code{save-tracepoints}} command is a deprecated |
12855 | alias for @w{@code{save tracepoints}} | |
b37052ae EZ |
12856 | |
12857 | @node Tracepoint Variables | |
12858 | @section Convenience Variables for Tracepoints | |
12859 | @cindex tracepoint variables | |
12860 | @cindex convenience variables for tracepoints | |
12861 | ||
12862 | @table @code | |
12863 | @vindex $trace_frame | |
12864 | @item (int) $trace_frame | |
12865 | The current trace snapshot (a.k.a.@: @dfn{frame}) number, or -1 if no | |
12866 | snapshot is selected. | |
12867 | ||
12868 | @vindex $tracepoint | |
12869 | @item (int) $tracepoint | |
12870 | The tracepoint for the current trace snapshot. | |
12871 | ||
12872 | @vindex $trace_line | |
12873 | @item (int) $trace_line | |
12874 | The line number for the current trace snapshot. | |
12875 | ||
12876 | @vindex $trace_file | |
12877 | @item (char []) $trace_file | |
12878 | The source file for the current trace snapshot. | |
12879 | ||
12880 | @vindex $trace_func | |
12881 | @item (char []) $trace_func | |
12882 | The name of the function containing @code{$tracepoint}. | |
12883 | @end table | |
12884 | ||
12885 | Note: @code{$trace_file} is not suitable for use in @code{printf}, | |
12886 | use @code{output} instead. | |
12887 | ||
12888 | Here's a simple example of using these convenience variables for | |
12889 | stepping through all the trace snapshots and printing some of their | |
f61e138d SS |
12890 | data. Note that these are not the same as trace state variables, |
12891 | which are managed by the target. | |
b37052ae EZ |
12892 | |
12893 | @smallexample | |
12894 | (@value{GDBP}) @b{tfind start} | |
12895 | ||
12896 | (@value{GDBP}) @b{while $trace_frame != -1} | |
12897 | > output $trace_file | |
12898 | > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint | |
12899 | > tfind | |
12900 | > end | |
12901 | @end smallexample | |
12902 | ||
00bf0b85 SS |
12903 | @node Trace Files |
12904 | @section Using Trace Files | |
12905 | @cindex trace files | |
12906 | ||
12907 | In some situations, the target running a trace experiment may no | |
12908 | longer be available; perhaps it crashed, or the hardware was needed | |
12909 | for a different activity. To handle these cases, you can arrange to | |
12910 | dump the trace data into a file, and later use that file as a source | |
12911 | of trace data, via the @code{target tfile} command. | |
12912 | ||
12913 | @table @code | |
12914 | ||
12915 | @kindex tsave | |
12916 | @item tsave [ -r ] @var{filename} | |
d0353e76 | 12917 | @itemx tsave [-ctf] @var{dirname} |
00bf0b85 SS |
12918 | Save the trace data to @var{filename}. By default, this command |
12919 | assumes that @var{filename} refers to the host filesystem, so if | |
12920 | necessary @value{GDBN} will copy raw trace data up from the target and | |
12921 | then save it. If the target supports it, you can also supply the | |
12922 | optional argument @code{-r} (``remote'') to direct the target to save | |
12923 | the data directly into @var{filename} in its own filesystem, which may be | |
12924 | more efficient if the trace buffer is very large. (Note, however, that | |
12925 | @code{target tfile} can only read from files accessible to the host.) | |
d0353e76 YQ |
12926 | By default, this command will save trace frame in tfile format. |
12927 | You can supply the optional argument @code{-ctf} to save date in CTF | |
12928 | format. The @dfn{Common Trace Format} (CTF) is proposed as a trace format | |
12929 | that can be shared by multiple debugging and tracing tools. Please go to | |
12930 | @indicateurl{http://www.efficios.com/ctf} to get more information. | |
00bf0b85 SS |
12931 | |
12932 | @kindex target tfile | |
12933 | @kindex tfile | |
393fd4c3 YQ |
12934 | @kindex target ctf |
12935 | @kindex ctf | |
00bf0b85 | 12936 | @item target tfile @var{filename} |
393fd4c3 YQ |
12937 | @itemx target ctf @var{dirname} |
12938 | Use the file named @var{filename} or directory named @var{dirname} as | |
12939 | a source of trace data. Commands that examine data work as they do with | |
12940 | a live target, but it is not possible to run any new trace experiments. | |
12941 | @code{tstatus} will report the state of the trace run at the moment | |
12942 | the data was saved, as well as the current trace frame you are examining. | |
697aa1b7 | 12943 | Both @var{filename} and @var{dirname} must be on a filesystem accessible to |
393fd4c3 YQ |
12944 | the host. |
12945 | ||
12946 | @smallexample | |
12947 | (@value{GDBP}) target ctf ctf.ctf | |
12948 | (@value{GDBP}) tfind | |
12949 | Found trace frame 0, tracepoint 2 | |
12950 | 39 ++a; /* set tracepoint 1 here */ | |
12951 | (@value{GDBP}) tdump | |
12952 | Data collected at tracepoint 2, trace frame 0: | |
12953 | i = 0 | |
12954 | a = 0 | |
12955 | b = 1 '\001' | |
12956 | c = @{"123", "456", "789", "123", "456", "789"@} | |
12957 | d = @{@{@{a = 1, b = 2@}, @{a = 3, b = 4@}@}, @{@{a = 5, b = 6@}, @{a = 7, b = 8@}@}@} | |
12958 | (@value{GDBP}) p b | |
12959 | $1 = 1 | |
12960 | @end smallexample | |
00bf0b85 SS |
12961 | |
12962 | @end table | |
12963 | ||
df0cd8c5 JB |
12964 | @node Overlays |
12965 | @chapter Debugging Programs That Use Overlays | |
12966 | @cindex overlays | |
12967 | ||
12968 | If your program is too large to fit completely in your target system's | |
12969 | memory, you can sometimes use @dfn{overlays} to work around this | |
12970 | problem. @value{GDBN} provides some support for debugging programs that | |
12971 | use overlays. | |
12972 | ||
12973 | @menu | |
12974 | * How Overlays Work:: A general explanation of overlays. | |
12975 | * Overlay Commands:: Managing overlays in @value{GDBN}. | |
12976 | * Automatic Overlay Debugging:: @value{GDBN} can find out which overlays are | |
12977 | mapped by asking the inferior. | |
12978 | * Overlay Sample Program:: A sample program using overlays. | |
12979 | @end menu | |
12980 | ||
12981 | @node How Overlays Work | |
12982 | @section How Overlays Work | |
12983 | @cindex mapped overlays | |
12984 | @cindex unmapped overlays | |
12985 | @cindex load address, overlay's | |
12986 | @cindex mapped address | |
12987 | @cindex overlay area | |
12988 | ||
12989 | Suppose you have a computer whose instruction address space is only 64 | |
12990 | kilobytes long, but which has much more memory which can be accessed by | |
12991 | other means: special instructions, segment registers, or memory | |
12992 | management hardware, for example. Suppose further that you want to | |
12993 | adapt a program which is larger than 64 kilobytes to run on this system. | |
12994 | ||
12995 | One solution is to identify modules of your program which are relatively | |
12996 | independent, and need not call each other directly; call these modules | |
12997 | @dfn{overlays}. Separate the overlays from the main program, and place | |
12998 | their machine code in the larger memory. Place your main program in | |
12999 | instruction memory, but leave at least enough space there to hold the | |
13000 | largest overlay as well. | |
13001 | ||
13002 | Now, to call a function located in an overlay, you must first copy that | |
13003 | overlay's machine code from the large memory into the space set aside | |
13004 | for it in the instruction memory, and then jump to its entry point | |
13005 | there. | |
13006 | ||
c928edc0 AC |
13007 | @c NB: In the below the mapped area's size is greater or equal to the |
13008 | @c size of all overlays. This is intentional to remind the developer | |
13009 | @c that overlays don't necessarily need to be the same size. | |
13010 | ||
474c8240 | 13011 | @smallexample |
df0cd8c5 | 13012 | @group |
c928edc0 AC |
13013 | Data Instruction Larger |
13014 | Address Space Address Space Address Space | |
13015 | +-----------+ +-----------+ +-----------+ | |
13016 | | | | | | | | |
13017 | +-----------+ +-----------+ +-----------+<-- overlay 1 | |
13018 | | program | | main | .----| overlay 1 | load address | |
13019 | | variables | | program | | +-----------+ | |
13020 | | and heap | | | | | | | |
13021 | +-----------+ | | | +-----------+<-- overlay 2 | |
13022 | | | +-----------+ | | | load address | |
13023 | +-----------+ | | | .-| overlay 2 | | |
13024 | | | | | | | | |
13025 | mapped --->+-----------+ | | +-----------+ | |
13026 | address | | | | | | | |
13027 | | overlay | <-' | | | | |
13028 | | area | <---' +-----------+<-- overlay 3 | |
13029 | | | <---. | | load address | |
13030 | +-----------+ `--| overlay 3 | | |
13031 | | | | | | |
13032 | +-----------+ | | | |
13033 | +-----------+ | |
13034 | | | | |
13035 | +-----------+ | |
13036 | ||
13037 | @anchor{A code overlay}A code overlay | |
df0cd8c5 | 13038 | @end group |
474c8240 | 13039 | @end smallexample |
df0cd8c5 | 13040 | |
c928edc0 AC |
13041 | The diagram (@pxref{A code overlay}) shows a system with separate data |
13042 | and instruction address spaces. To map an overlay, the program copies | |
13043 | its code from the larger address space to the instruction address space. | |
13044 | Since the overlays shown here all use the same mapped address, only one | |
13045 | may be mapped at a time. For a system with a single address space for | |
13046 | data and instructions, the diagram would be similar, except that the | |
13047 | program variables and heap would share an address space with the main | |
13048 | program and the overlay area. | |
df0cd8c5 JB |
13049 | |
13050 | An overlay loaded into instruction memory and ready for use is called a | |
13051 | @dfn{mapped} overlay; its @dfn{mapped address} is its address in the | |
13052 | instruction memory. An overlay not present (or only partially present) | |
13053 | in instruction memory is called @dfn{unmapped}; its @dfn{load address} | |
13054 | is its address in the larger memory. The mapped address is also called | |
13055 | the @dfn{virtual memory address}, or @dfn{VMA}; the load address is also | |
13056 | called the @dfn{load memory address}, or @dfn{LMA}. | |
13057 | ||
13058 | Unfortunately, overlays are not a completely transparent way to adapt a | |
13059 | program to limited instruction memory. They introduce a new set of | |
13060 | global constraints you must keep in mind as you design your program: | |
13061 | ||
13062 | @itemize @bullet | |
13063 | ||
13064 | @item | |
13065 | Before calling or returning to a function in an overlay, your program | |
13066 | must make sure that overlay is actually mapped. Otherwise, the call or | |
13067 | return will transfer control to the right address, but in the wrong | |
13068 | overlay, and your program will probably crash. | |
13069 | ||
13070 | @item | |
13071 | If the process of mapping an overlay is expensive on your system, you | |
13072 | will need to choose your overlays carefully to minimize their effect on | |
13073 | your program's performance. | |
13074 | ||
13075 | @item | |
13076 | The executable file you load onto your system must contain each | |
13077 | overlay's instructions, appearing at the overlay's load address, not its | |
13078 | mapped address. However, each overlay's instructions must be relocated | |
13079 | and its symbols defined as if the overlay were at its mapped address. | |
13080 | You can use GNU linker scripts to specify different load and relocation | |
13081 | addresses for pieces of your program; see @ref{Overlay Description,,, | |
13082 | ld.info, Using ld: the GNU linker}. | |
13083 | ||
13084 | @item | |
13085 | The procedure for loading executable files onto your system must be able | |
13086 | to load their contents into the larger address space as well as the | |
13087 | instruction and data spaces. | |
13088 | ||
13089 | @end itemize | |
13090 | ||
13091 | The overlay system described above is rather simple, and could be | |
13092 | improved in many ways: | |
13093 | ||
13094 | @itemize @bullet | |
13095 | ||
13096 | @item | |
13097 | If your system has suitable bank switch registers or memory management | |
13098 | hardware, you could use those facilities to make an overlay's load area | |
13099 | contents simply appear at their mapped address in instruction space. | |
13100 | This would probably be faster than copying the overlay to its mapped | |
13101 | area in the usual way. | |
13102 | ||
13103 | @item | |
13104 | If your overlays are small enough, you could set aside more than one | |
13105 | overlay area, and have more than one overlay mapped at a time. | |
13106 | ||
13107 | @item | |
13108 | You can use overlays to manage data, as well as instructions. In | |
13109 | general, data overlays are even less transparent to your design than | |
13110 | code overlays: whereas code overlays only require care when you call or | |
13111 | return to functions, data overlays require care every time you access | |
13112 | the data. Also, if you change the contents of a data overlay, you | |
13113 | must copy its contents back out to its load address before you can copy a | |
13114 | different data overlay into the same mapped area. | |
13115 | ||
13116 | @end itemize | |
13117 | ||
13118 | ||
13119 | @node Overlay Commands | |
13120 | @section Overlay Commands | |
13121 | ||
13122 | To use @value{GDBN}'s overlay support, each overlay in your program must | |
13123 | correspond to a separate section of the executable file. The section's | |
13124 | virtual memory address and load memory address must be the overlay's | |
13125 | mapped and load addresses. Identifying overlays with sections allows | |
13126 | @value{GDBN} to determine the appropriate address of a function or | |
13127 | variable, depending on whether the overlay is mapped or not. | |
13128 | ||
13129 | @value{GDBN}'s overlay commands all start with the word @code{overlay}; | |
13130 | you can abbreviate this as @code{ov} or @code{ovly}. The commands are: | |
13131 | ||
13132 | @table @code | |
13133 | @item overlay off | |
4644b6e3 | 13134 | @kindex overlay |
df0cd8c5 JB |
13135 | Disable @value{GDBN}'s overlay support. When overlay support is |
13136 | disabled, @value{GDBN} assumes that all functions and variables are | |
13137 | always present at their mapped addresses. By default, @value{GDBN}'s | |
13138 | overlay support is disabled. | |
13139 | ||
13140 | @item overlay manual | |
df0cd8c5 JB |
13141 | @cindex manual overlay debugging |
13142 | Enable @dfn{manual} overlay debugging. In this mode, @value{GDBN} | |
13143 | relies on you to tell it which overlays are mapped, and which are not, | |
13144 | using the @code{overlay map-overlay} and @code{overlay unmap-overlay} | |
13145 | commands described below. | |
13146 | ||
13147 | @item overlay map-overlay @var{overlay} | |
13148 | @itemx overlay map @var{overlay} | |
df0cd8c5 JB |
13149 | @cindex map an overlay |
13150 | Tell @value{GDBN} that @var{overlay} is now mapped; @var{overlay} must | |
13151 | be the name of the object file section containing the overlay. When an | |
13152 | overlay is mapped, @value{GDBN} assumes it can find the overlay's | |
13153 | functions and variables at their mapped addresses. @value{GDBN} assumes | |
13154 | that any other overlays whose mapped ranges overlap that of | |
13155 | @var{overlay} are now unmapped. | |
13156 | ||
13157 | @item overlay unmap-overlay @var{overlay} | |
13158 | @itemx overlay unmap @var{overlay} | |
df0cd8c5 JB |
13159 | @cindex unmap an overlay |
13160 | Tell @value{GDBN} that @var{overlay} is no longer mapped; @var{overlay} | |
13161 | must be the name of the object file section containing the overlay. | |
13162 | When an overlay is unmapped, @value{GDBN} assumes it can find the | |
13163 | overlay's functions and variables at their load addresses. | |
13164 | ||
13165 | @item overlay auto | |
df0cd8c5 JB |
13166 | Enable @dfn{automatic} overlay debugging. In this mode, @value{GDBN} |
13167 | consults a data structure the overlay manager maintains in the inferior | |
13168 | to see which overlays are mapped. For details, see @ref{Automatic | |
13169 | Overlay Debugging}. | |
13170 | ||
13171 | @item overlay load-target | |
13172 | @itemx overlay load | |
df0cd8c5 JB |
13173 | @cindex reloading the overlay table |
13174 | Re-read the overlay table from the inferior. Normally, @value{GDBN} | |
13175 | re-reads the table @value{GDBN} automatically each time the inferior | |
13176 | stops, so this command should only be necessary if you have changed the | |
13177 | overlay mapping yourself using @value{GDBN}. This command is only | |
13178 | useful when using automatic overlay debugging. | |
13179 | ||
13180 | @item overlay list-overlays | |
13181 | @itemx overlay list | |
13182 | @cindex listing mapped overlays | |
13183 | Display a list of the overlays currently mapped, along with their mapped | |
13184 | addresses, load addresses, and sizes. | |
13185 | ||
13186 | @end table | |
13187 | ||
13188 | Normally, when @value{GDBN} prints a code address, it includes the name | |
13189 | of the function the address falls in: | |
13190 | ||
474c8240 | 13191 | @smallexample |
f7dc1244 | 13192 | (@value{GDBP}) print main |
df0cd8c5 | 13193 | $3 = @{int ()@} 0x11a0 <main> |
474c8240 | 13194 | @end smallexample |
df0cd8c5 JB |
13195 | @noindent |
13196 | When overlay debugging is enabled, @value{GDBN} recognizes code in | |
13197 | unmapped overlays, and prints the names of unmapped functions with | |
13198 | asterisks around them. For example, if @code{foo} is a function in an | |
13199 | unmapped overlay, @value{GDBN} prints it this way: | |
13200 | ||
474c8240 | 13201 | @smallexample |
f7dc1244 | 13202 | (@value{GDBP}) overlay list |
df0cd8c5 | 13203 | No sections are mapped. |
f7dc1244 | 13204 | (@value{GDBP}) print foo |
df0cd8c5 | 13205 | $5 = @{int (int)@} 0x100000 <*foo*> |
474c8240 | 13206 | @end smallexample |
df0cd8c5 JB |
13207 | @noindent |
13208 | When @code{foo}'s overlay is mapped, @value{GDBN} prints the function's | |
13209 | name normally: | |
13210 | ||
474c8240 | 13211 | @smallexample |
f7dc1244 | 13212 | (@value{GDBP}) overlay list |
b383017d | 13213 | Section .ov.foo.text, loaded at 0x100000 - 0x100034, |
df0cd8c5 | 13214 | mapped at 0x1016 - 0x104a |
f7dc1244 | 13215 | (@value{GDBP}) print foo |
df0cd8c5 | 13216 | $6 = @{int (int)@} 0x1016 <foo> |
474c8240 | 13217 | @end smallexample |
df0cd8c5 JB |
13218 | |
13219 | When overlay debugging is enabled, @value{GDBN} can find the correct | |
13220 | address for functions and variables in an overlay, whether or not the | |
13221 | overlay is mapped. This allows most @value{GDBN} commands, like | |
13222 | @code{break} and @code{disassemble}, to work normally, even on unmapped | |
13223 | code. However, @value{GDBN}'s breakpoint support has some limitations: | |
13224 | ||
13225 | @itemize @bullet | |
13226 | @item | |
13227 | @cindex breakpoints in overlays | |
13228 | @cindex overlays, setting breakpoints in | |
13229 | You can set breakpoints in functions in unmapped overlays, as long as | |
13230 | @value{GDBN} can write to the overlay at its load address. | |
13231 | @item | |
13232 | @value{GDBN} can not set hardware or simulator-based breakpoints in | |
13233 | unmapped overlays. However, if you set a breakpoint at the end of your | |
13234 | overlay manager (and tell @value{GDBN} which overlays are now mapped, if | |
13235 | you are using manual overlay management), @value{GDBN} will re-set its | |
13236 | breakpoints properly. | |
13237 | @end itemize | |
13238 | ||
13239 | ||
13240 | @node Automatic Overlay Debugging | |
13241 | @section Automatic Overlay Debugging | |
13242 | @cindex automatic overlay debugging | |
13243 | ||
13244 | @value{GDBN} can automatically track which overlays are mapped and which | |
13245 | are not, given some simple co-operation from the overlay manager in the | |
13246 | inferior. If you enable automatic overlay debugging with the | |
13247 | @code{overlay auto} command (@pxref{Overlay Commands}), @value{GDBN} | |
13248 | looks in the inferior's memory for certain variables describing the | |
13249 | current state of the overlays. | |
13250 | ||
13251 | Here are the variables your overlay manager must define to support | |
13252 | @value{GDBN}'s automatic overlay debugging: | |
13253 | ||
13254 | @table @asis | |
13255 | ||
13256 | @item @code{_ovly_table}: | |
13257 | This variable must be an array of the following structures: | |
13258 | ||
474c8240 | 13259 | @smallexample |
df0cd8c5 JB |
13260 | struct |
13261 | @{ | |
13262 | /* The overlay's mapped address. */ | |
13263 | unsigned long vma; | |
13264 | ||
13265 | /* The size of the overlay, in bytes. */ | |
13266 | unsigned long size; | |
13267 | ||
13268 | /* The overlay's load address. */ | |
13269 | unsigned long lma; | |
13270 | ||
13271 | /* Non-zero if the overlay is currently mapped; | |
13272 | zero otherwise. */ | |
13273 | unsigned long mapped; | |
13274 | @} | |
474c8240 | 13275 | @end smallexample |
df0cd8c5 JB |
13276 | |
13277 | @item @code{_novlys}: | |
13278 | This variable must be a four-byte signed integer, holding the total | |
13279 | number of elements in @code{_ovly_table}. | |
13280 | ||
13281 | @end table | |
13282 | ||
13283 | To decide whether a particular overlay is mapped or not, @value{GDBN} | |
13284 | looks for an entry in @w{@code{_ovly_table}} whose @code{vma} and | |
13285 | @code{lma} members equal the VMA and LMA of the overlay's section in the | |
13286 | executable file. When @value{GDBN} finds a matching entry, it consults | |
13287 | the entry's @code{mapped} member to determine whether the overlay is | |
13288 | currently mapped. | |
13289 | ||
81d46470 | 13290 | In addition, your overlay manager may define a function called |
def71bfa | 13291 | @code{_ovly_debug_event}. If this function is defined, @value{GDBN} |
81d46470 MS |
13292 | will silently set a breakpoint there. If the overlay manager then |
13293 | calls this function whenever it has changed the overlay table, this | |
13294 | will enable @value{GDBN} to accurately keep track of which overlays | |
13295 | are in program memory, and update any breakpoints that may be set | |
b383017d | 13296 | in overlays. This will allow breakpoints to work even if the |
81d46470 MS |
13297 | overlays are kept in ROM or other non-writable memory while they |
13298 | are not being executed. | |
df0cd8c5 JB |
13299 | |
13300 | @node Overlay Sample Program | |
13301 | @section Overlay Sample Program | |
13302 | @cindex overlay example program | |
13303 | ||
13304 | When linking a program which uses overlays, you must place the overlays | |
13305 | at their load addresses, while relocating them to run at their mapped | |
13306 | addresses. To do this, you must write a linker script (@pxref{Overlay | |
13307 | Description,,, ld.info, Using ld: the GNU linker}). Unfortunately, | |
13308 | since linker scripts are specific to a particular host system, target | |
13309 | architecture, and target memory layout, this manual cannot provide | |
13310 | portable sample code demonstrating @value{GDBN}'s overlay support. | |
13311 | ||
13312 | However, the @value{GDBN} source distribution does contain an overlaid | |
13313 | program, with linker scripts for a few systems, as part of its test | |
13314 | suite. The program consists of the following files from | |
13315 | @file{gdb/testsuite/gdb.base}: | |
13316 | ||
13317 | @table @file | |
13318 | @item overlays.c | |
13319 | The main program file. | |
13320 | @item ovlymgr.c | |
13321 | A simple overlay manager, used by @file{overlays.c}. | |
13322 | @item foo.c | |
13323 | @itemx bar.c | |
13324 | @itemx baz.c | |
13325 | @itemx grbx.c | |
13326 | Overlay modules, loaded and used by @file{overlays.c}. | |
13327 | @item d10v.ld | |
13328 | @itemx m32r.ld | |
13329 | Linker scripts for linking the test program on the @code{d10v-elf} | |
13330 | and @code{m32r-elf} targets. | |
13331 | @end table | |
13332 | ||
13333 | You can build the test program using the @code{d10v-elf} GCC | |
13334 | cross-compiler like this: | |
13335 | ||
474c8240 | 13336 | @smallexample |
df0cd8c5 JB |
13337 | $ d10v-elf-gcc -g -c overlays.c |
13338 | $ d10v-elf-gcc -g -c ovlymgr.c | |
13339 | $ d10v-elf-gcc -g -c foo.c | |
13340 | $ d10v-elf-gcc -g -c bar.c | |
13341 | $ d10v-elf-gcc -g -c baz.c | |
13342 | $ d10v-elf-gcc -g -c grbx.c | |
13343 | $ d10v-elf-gcc -g overlays.o ovlymgr.o foo.o bar.o \ | |
13344 | baz.o grbx.o -Wl,-Td10v.ld -o overlays | |
474c8240 | 13345 | @end smallexample |
df0cd8c5 JB |
13346 | |
13347 | The build process is identical for any other architecture, except that | |
13348 | you must substitute the appropriate compiler and linker script for the | |
13349 | target system for @code{d10v-elf-gcc} and @code{d10v.ld}. | |
13350 | ||
13351 | ||
6d2ebf8b | 13352 | @node Languages |
c906108c SS |
13353 | @chapter Using @value{GDBN} with Different Languages |
13354 | @cindex languages | |
13355 | ||
c906108c SS |
13356 | Although programming languages generally have common aspects, they are |
13357 | rarely expressed in the same manner. For instance, in ANSI C, | |
13358 | dereferencing a pointer @code{p} is accomplished by @code{*p}, but in | |
13359 | Modula-2, it is accomplished by @code{p^}. Values can also be | |
5d161b24 | 13360 | represented (and displayed) differently. Hex numbers in C appear as |
c906108c | 13361 | @samp{0x1ae}, while in Modula-2 they appear as @samp{1AEH}. |
c906108c SS |
13362 | |
13363 | @cindex working language | |
13364 | Language-specific information is built into @value{GDBN} for some languages, | |
13365 | allowing you to express operations like the above in your program's | |
13366 | native language, and allowing @value{GDBN} to output values in a manner | |
13367 | consistent with the syntax of your program's native language. The | |
13368 | language you use to build expressions is called the @dfn{working | |
13369 | language}. | |
13370 | ||
13371 | @menu | |
13372 | * Setting:: Switching between source languages | |
13373 | * Show:: Displaying the language | |
c906108c | 13374 | * Checks:: Type and range checks |
79a6e687 BW |
13375 | * Supported Languages:: Supported languages |
13376 | * Unsupported Languages:: Unsupported languages | |
c906108c SS |
13377 | @end menu |
13378 | ||
6d2ebf8b | 13379 | @node Setting |
79a6e687 | 13380 | @section Switching Between Source Languages |
c906108c SS |
13381 | |
13382 | There are two ways to control the working language---either have @value{GDBN} | |
13383 | set it automatically, or select it manually yourself. You can use the | |
13384 | @code{set language} command for either purpose. On startup, @value{GDBN} | |
13385 | defaults to setting the language automatically. The working language is | |
13386 | used to determine how expressions you type are interpreted, how values | |
13387 | are printed, etc. | |
13388 | ||
13389 | In addition to the working language, every source file that | |
13390 | @value{GDBN} knows about has its own working language. For some object | |
13391 | file formats, the compiler might indicate which language a particular | |
13392 | source file is in. However, most of the time @value{GDBN} infers the | |
13393 | language from the name of the file. The language of a source file | |
b37052ae | 13394 | controls whether C@t{++} names are demangled---this way @code{backtrace} can |
c906108c | 13395 | show each frame appropriately for its own language. There is no way to |
d4f3574e SS |
13396 | set the language of a source file from within @value{GDBN}, but you can |
13397 | set the language associated with a filename extension. @xref{Show, , | |
79a6e687 | 13398 | Displaying the Language}. |
c906108c SS |
13399 | |
13400 | This is most commonly a problem when you use a program, such | |
5d161b24 | 13401 | as @code{cfront} or @code{f2c}, that generates C but is written in |
c906108c SS |
13402 | another language. In that case, make the |
13403 | program use @code{#line} directives in its C output; that way | |
13404 | @value{GDBN} will know the correct language of the source code of the original | |
13405 | program, and will display that source code, not the generated C code. | |
13406 | ||
13407 | @menu | |
13408 | * Filenames:: Filename extensions and languages. | |
13409 | * Manually:: Setting the working language manually | |
13410 | * Automatically:: Having @value{GDBN} infer the source language | |
13411 | @end menu | |
13412 | ||
6d2ebf8b | 13413 | @node Filenames |
79a6e687 | 13414 | @subsection List of Filename Extensions and Languages |
c906108c SS |
13415 | |
13416 | If a source file name ends in one of the following extensions, then | |
13417 | @value{GDBN} infers that its language is the one indicated. | |
13418 | ||
13419 | @table @file | |
e07c999f PH |
13420 | @item .ada |
13421 | @itemx .ads | |
13422 | @itemx .adb | |
13423 | @itemx .a | |
13424 | Ada source file. | |
c906108c SS |
13425 | |
13426 | @item .c | |
13427 | C source file | |
13428 | ||
13429 | @item .C | |
13430 | @itemx .cc | |
13431 | @itemx .cp | |
13432 | @itemx .cpp | |
13433 | @itemx .cxx | |
13434 | @itemx .c++ | |
b37052ae | 13435 | C@t{++} source file |
c906108c | 13436 | |
6aecb9c2 JB |
13437 | @item .d |
13438 | D source file | |
13439 | ||
b37303ee AF |
13440 | @item .m |
13441 | Objective-C source file | |
13442 | ||
c906108c SS |
13443 | @item .f |
13444 | @itemx .F | |
13445 | Fortran source file | |
13446 | ||
c906108c SS |
13447 | @item .mod |
13448 | Modula-2 source file | |
c906108c SS |
13449 | |
13450 | @item .s | |
13451 | @itemx .S | |
13452 | Assembler source file. This actually behaves almost like C, but | |
13453 | @value{GDBN} does not skip over function prologues when stepping. | |
13454 | @end table | |
13455 | ||
13456 | In addition, you may set the language associated with a filename | |
79a6e687 | 13457 | extension. @xref{Show, , Displaying the Language}. |
c906108c | 13458 | |
6d2ebf8b | 13459 | @node Manually |
79a6e687 | 13460 | @subsection Setting the Working Language |
c906108c SS |
13461 | |
13462 | If you allow @value{GDBN} to set the language automatically, | |
13463 | expressions are interpreted the same way in your debugging session and | |
13464 | your program. | |
13465 | ||
13466 | @kindex set language | |
13467 | If you wish, you may set the language manually. To do this, issue the | |
13468 | command @samp{set language @var{lang}}, where @var{lang} is the name of | |
5d161b24 | 13469 | a language, such as |
c906108c | 13470 | @code{c} or @code{modula-2}. |
c906108c SS |
13471 | For a list of the supported languages, type @samp{set language}. |
13472 | ||
c906108c SS |
13473 | Setting the language manually prevents @value{GDBN} from updating the working |
13474 | language automatically. This can lead to confusion if you try | |
13475 | to debug a program when the working language is not the same as the | |
13476 | source language, when an expression is acceptable to both | |
13477 | languages---but means different things. For instance, if the current | |
13478 | source file were written in C, and @value{GDBN} was parsing Modula-2, a | |
13479 | command such as: | |
13480 | ||
474c8240 | 13481 | @smallexample |
c906108c | 13482 | print a = b + c |
474c8240 | 13483 | @end smallexample |
c906108c SS |
13484 | |
13485 | @noindent | |
13486 | might not have the effect you intended. In C, this means to add | |
13487 | @code{b} and @code{c} and place the result in @code{a}. The result | |
13488 | printed would be the value of @code{a}. In Modula-2, this means to compare | |
13489 | @code{a} to the result of @code{b+c}, yielding a @code{BOOLEAN} value. | |
c906108c | 13490 | |
6d2ebf8b | 13491 | @node Automatically |
79a6e687 | 13492 | @subsection Having @value{GDBN} Infer the Source Language |
c906108c SS |
13493 | |
13494 | To have @value{GDBN} set the working language automatically, use | |
13495 | @samp{set language local} or @samp{set language auto}. @value{GDBN} | |
13496 | then infers the working language. That is, when your program stops in a | |
13497 | frame (usually by encountering a breakpoint), @value{GDBN} sets the | |
13498 | working language to the language recorded for the function in that | |
13499 | frame. If the language for a frame is unknown (that is, if the function | |
13500 | or block corresponding to the frame was defined in a source file that | |
13501 | does not have a recognized extension), the current working language is | |
13502 | not changed, and @value{GDBN} issues a warning. | |
13503 | ||
13504 | This may not seem necessary for most programs, which are written | |
13505 | entirely in one source language. However, program modules and libraries | |
13506 | written in one source language can be used by a main program written in | |
13507 | a different source language. Using @samp{set language auto} in this | |
13508 | case frees you from having to set the working language manually. | |
13509 | ||
6d2ebf8b | 13510 | @node Show |
79a6e687 | 13511 | @section Displaying the Language |
c906108c SS |
13512 | |
13513 | The following commands help you find out which language is the | |
13514 | working language, and also what language source files were written in. | |
13515 | ||
c906108c SS |
13516 | @table @code |
13517 | @item show language | |
403cb6b1 | 13518 | @anchor{show language} |
9c16f35a | 13519 | @kindex show language |
c906108c SS |
13520 | Display the current working language. This is the |
13521 | language you can use with commands such as @code{print} to | |
13522 | build and compute expressions that may involve variables in your program. | |
13523 | ||
13524 | @item info frame | |
4644b6e3 | 13525 | @kindex info frame@r{, show the source language} |
5d161b24 | 13526 | Display the source language for this frame. This language becomes the |
c906108c | 13527 | working language if you use an identifier from this frame. |
79a6e687 | 13528 | @xref{Frame Info, ,Information about a Frame}, to identify the other |
c906108c SS |
13529 | information listed here. |
13530 | ||
13531 | @item info source | |
4644b6e3 | 13532 | @kindex info source@r{, show the source language} |
c906108c | 13533 | Display the source language of this source file. |
5d161b24 | 13534 | @xref{Symbols, ,Examining the Symbol Table}, to identify the other |
c906108c SS |
13535 | information listed here. |
13536 | @end table | |
13537 | ||
13538 | In unusual circumstances, you may have source files with extensions | |
13539 | not in the standard list. You can then set the extension associated | |
13540 | with a language explicitly: | |
13541 | ||
c906108c | 13542 | @table @code |
09d4efe1 | 13543 | @item set extension-language @var{ext} @var{language} |
9c16f35a | 13544 | @kindex set extension-language |
09d4efe1 EZ |
13545 | Tell @value{GDBN} that source files with extension @var{ext} are to be |
13546 | assumed as written in the source language @var{language}. | |
c906108c SS |
13547 | |
13548 | @item info extensions | |
9c16f35a | 13549 | @kindex info extensions |
c906108c SS |
13550 | List all the filename extensions and the associated languages. |
13551 | @end table | |
13552 | ||
6d2ebf8b | 13553 | @node Checks |
79a6e687 | 13554 | @section Type and Range Checking |
c906108c | 13555 | |
c906108c SS |
13556 | Some languages are designed to guard you against making seemingly common |
13557 | errors through a series of compile- and run-time checks. These include | |
a451cb65 | 13558 | checking the type of arguments to functions and operators and making |
c906108c SS |
13559 | sure mathematical overflows are caught at run time. Checks such as |
13560 | these help to ensure a program's correctness once it has been compiled | |
a451cb65 | 13561 | by eliminating type mismatches and providing active checks for range |
c906108c SS |
13562 | errors when your program is running. |
13563 | ||
a451cb65 KS |
13564 | By default @value{GDBN} checks for these errors according to the |
13565 | rules of the current source language. Although @value{GDBN} does not check | |
13566 | the statements in your program, it can check expressions entered directly | |
13567 | into @value{GDBN} for evaluation via the @code{print} command, for example. | |
c906108c SS |
13568 | |
13569 | @menu | |
13570 | * Type Checking:: An overview of type checking | |
13571 | * Range Checking:: An overview of range checking | |
13572 | @end menu | |
13573 | ||
13574 | @cindex type checking | |
13575 | @cindex checks, type | |
6d2ebf8b | 13576 | @node Type Checking |
79a6e687 | 13577 | @subsection An Overview of Type Checking |
c906108c | 13578 | |
a451cb65 | 13579 | Some languages, such as C and C@t{++}, are strongly typed, meaning that the |
c906108c SS |
13580 | arguments to operators and functions have to be of the correct type, |
13581 | otherwise an error occurs. These checks prevent type mismatch | |
13582 | errors from ever causing any run-time problems. For example, | |
13583 | ||
13584 | @smallexample | |
a451cb65 KS |
13585 | int klass::my_method(char *b) @{ return b ? 1 : 2; @} |
13586 | ||
13587 | (@value{GDBP}) print obj.my_method (0) | |
13588 | $1 = 2 | |
c906108c | 13589 | @exdent but |
a451cb65 KS |
13590 | (@value{GDBP}) print obj.my_method (0x1234) |
13591 | Cannot resolve method klass::my_method to any overloaded instance | |
c906108c SS |
13592 | @end smallexample |
13593 | ||
a451cb65 KS |
13594 | The second example fails because in C@t{++} the integer constant |
13595 | @samp{0x1234} is not type-compatible with the pointer parameter type. | |
c906108c | 13596 | |
a451cb65 KS |
13597 | For the expressions you use in @value{GDBN} commands, you can tell |
13598 | @value{GDBN} to not enforce strict type checking or | |
5d161b24 | 13599 | to treat any mismatches as errors and abandon the expression; |
a451cb65 KS |
13600 | When type checking is disabled, @value{GDBN} successfully evaluates |
13601 | expressions like the second example above. | |
c906108c | 13602 | |
a451cb65 | 13603 | Even if type checking is off, there may be other reasons |
5d161b24 DB |
13604 | related to type that prevent @value{GDBN} from evaluating an expression. |
13605 | For instance, @value{GDBN} does not know how to add an @code{int} and | |
13606 | a @code{struct foo}. These particular type errors have nothing to do | |
a451cb65 KS |
13607 | with the language in use and usually arise from expressions which make |
13608 | little sense to evaluate anyway. | |
c906108c | 13609 | |
a451cb65 | 13610 | @value{GDBN} provides some additional commands for controlling type checking: |
c906108c | 13611 | |
c906108c SS |
13612 | @kindex set check type |
13613 | @kindex show check type | |
13614 | @table @code | |
c906108c SS |
13615 | @item set check type on |
13616 | @itemx set check type off | |
a451cb65 | 13617 | Set strict type checking on or off. If any type mismatches occur in |
d4f3574e | 13618 | evaluating an expression while type checking is on, @value{GDBN} prints a |
c906108c SS |
13619 | message and aborts evaluation of the expression. |
13620 | ||
a451cb65 KS |
13621 | @item show check type |
13622 | Show the current setting of type checking and whether @value{GDBN} | |
13623 | is enforcing strict type checking rules. | |
c906108c SS |
13624 | @end table |
13625 | ||
13626 | @cindex range checking | |
13627 | @cindex checks, range | |
6d2ebf8b | 13628 | @node Range Checking |
79a6e687 | 13629 | @subsection An Overview of Range Checking |
c906108c SS |
13630 | |
13631 | In some languages (such as Modula-2), it is an error to exceed the | |
13632 | bounds of a type; this is enforced with run-time checks. Such range | |
13633 | checking is meant to ensure program correctness by making sure | |
13634 | computations do not overflow, or indices on an array element access do | |
13635 | not exceed the bounds of the array. | |
13636 | ||
13637 | For expressions you use in @value{GDBN} commands, you can tell | |
13638 | @value{GDBN} to treat range errors in one of three ways: ignore them, | |
13639 | always treat them as errors and abandon the expression, or issue | |
13640 | warnings but evaluate the expression anyway. | |
13641 | ||
13642 | A range error can result from numerical overflow, from exceeding an | |
13643 | array index bound, or when you type a constant that is not a member | |
13644 | of any type. Some languages, however, do not treat overflows as an | |
13645 | error. In many implementations of C, mathematical overflow causes the | |
13646 | result to ``wrap around'' to lower values---for example, if @var{m} is | |
13647 | the largest integer value, and @var{s} is the smallest, then | |
13648 | ||
474c8240 | 13649 | @smallexample |
c906108c | 13650 | @var{m} + 1 @result{} @var{s} |
474c8240 | 13651 | @end smallexample |
c906108c SS |
13652 | |
13653 | This, too, is specific to individual languages, and in some cases | |
79a6e687 BW |
13654 | specific to individual compilers or machines. @xref{Supported Languages, , |
13655 | Supported Languages}, for further details on specific languages. | |
c906108c SS |
13656 | |
13657 | @value{GDBN} provides some additional commands for controlling the range checker: | |
13658 | ||
c906108c SS |
13659 | @kindex set check range |
13660 | @kindex show check range | |
13661 | @table @code | |
13662 | @item set check range auto | |
13663 | Set range checking on or off based on the current working language. | |
79a6e687 | 13664 | @xref{Supported Languages, ,Supported Languages}, for the default settings for |
c906108c SS |
13665 | each language. |
13666 | ||
13667 | @item set check range on | |
13668 | @itemx set check range off | |
13669 | Set range checking on or off, overriding the default setting for the | |
13670 | current working language. A warning is issued if the setting does not | |
c3f6f71d JM |
13671 | match the language default. If a range error occurs and range checking is on, |
13672 | then a message is printed and evaluation of the expression is aborted. | |
c906108c SS |
13673 | |
13674 | @item set check range warn | |
13675 | Output messages when the @value{GDBN} range checker detects a range error, | |
13676 | but attempt to evaluate the expression anyway. Evaluating the | |
13677 | expression may still be impossible for other reasons, such as accessing | |
13678 | memory that the process does not own (a typical example from many Unix | |
13679 | systems). | |
13680 | ||
13681 | @item show range | |
13682 | Show the current setting of the range checker, and whether or not it is | |
13683 | being set automatically by @value{GDBN}. | |
13684 | @end table | |
c906108c | 13685 | |
79a6e687 BW |
13686 | @node Supported Languages |
13687 | @section Supported Languages | |
c906108c | 13688 | |
a766d390 DE |
13689 | @value{GDBN} supports C, C@t{++}, D, Go, Objective-C, Fortran, Java, |
13690 | OpenCL C, Pascal, assembly, Modula-2, and Ada. | |
cce74817 | 13691 | @c This is false ... |
c906108c SS |
13692 | Some @value{GDBN} features may be used in expressions regardless of the |
13693 | language you use: the @value{GDBN} @code{@@} and @code{::} operators, | |
13694 | and the @samp{@{type@}addr} construct (@pxref{Expressions, | |
13695 | ,Expressions}) can be used with the constructs of any supported | |
13696 | language. | |
13697 | ||
13698 | The following sections detail to what degree each source language is | |
13699 | supported by @value{GDBN}. These sections are not meant to be language | |
13700 | tutorials or references, but serve only as a reference guide to what the | |
13701 | @value{GDBN} expression parser accepts, and what input and output | |
13702 | formats should look like for different languages. There are many good | |
13703 | books written on each of these languages; please look to these for a | |
13704 | language reference or tutorial. | |
13705 | ||
c906108c | 13706 | @menu |
b37303ee | 13707 | * C:: C and C@t{++} |
6aecb9c2 | 13708 | * D:: D |
a766d390 | 13709 | * Go:: Go |
b383017d | 13710 | * Objective-C:: Objective-C |
f4b8a18d | 13711 | * OpenCL C:: OpenCL C |
09d4efe1 | 13712 | * Fortran:: Fortran |
9c16f35a | 13713 | * Pascal:: Pascal |
b37303ee | 13714 | * Modula-2:: Modula-2 |
e07c999f | 13715 | * Ada:: Ada |
c906108c SS |
13716 | @end menu |
13717 | ||
6d2ebf8b | 13718 | @node C |
b37052ae | 13719 | @subsection C and C@t{++} |
7a292a7a | 13720 | |
b37052ae EZ |
13721 | @cindex C and C@t{++} |
13722 | @cindex expressions in C or C@t{++} | |
c906108c | 13723 | |
b37052ae | 13724 | Since C and C@t{++} are so closely related, many features of @value{GDBN} apply |
c906108c SS |
13725 | to both languages. Whenever this is the case, we discuss those languages |
13726 | together. | |
13727 | ||
41afff9a EZ |
13728 | @cindex C@t{++} |
13729 | @cindex @code{g++}, @sc{gnu} C@t{++} compiler | |
b37052ae EZ |
13730 | @cindex @sc{gnu} C@t{++} |
13731 | The C@t{++} debugging facilities are jointly implemented by the C@t{++} | |
13732 | compiler and @value{GDBN}. Therefore, to debug your C@t{++} code | |
13733 | effectively, you must compile your C@t{++} programs with a supported | |
13734 | C@t{++} compiler, such as @sc{gnu} @code{g++}, or the HP ANSI C@t{++} | |
c906108c SS |
13735 | compiler (@code{aCC}). |
13736 | ||
c906108c | 13737 | @menu |
b37052ae EZ |
13738 | * C Operators:: C and C@t{++} operators |
13739 | * C Constants:: C and C@t{++} constants | |
79a6e687 | 13740 | * C Plus Plus Expressions:: C@t{++} expressions |
b37052ae EZ |
13741 | * C Defaults:: Default settings for C and C@t{++} |
13742 | * C Checks:: C and C@t{++} type and range checks | |
c906108c | 13743 | * Debugging C:: @value{GDBN} and C |
79a6e687 | 13744 | * Debugging C Plus Plus:: @value{GDBN} features for C@t{++} |
febe4383 | 13745 | * Decimal Floating Point:: Numbers in Decimal Floating Point format |
c906108c | 13746 | @end menu |
c906108c | 13747 | |
6d2ebf8b | 13748 | @node C Operators |
79a6e687 | 13749 | @subsubsection C and C@t{++} Operators |
7a292a7a | 13750 | |
b37052ae | 13751 | @cindex C and C@t{++} operators |
c906108c SS |
13752 | |
13753 | Operators must be defined on values of specific types. For instance, | |
13754 | @code{+} is defined on numbers, but not on structures. Operators are | |
5d161b24 | 13755 | often defined on groups of types. |
c906108c | 13756 | |
b37052ae | 13757 | For the purposes of C and C@t{++}, the following definitions hold: |
c906108c SS |
13758 | |
13759 | @itemize @bullet | |
53a5351d | 13760 | |
c906108c | 13761 | @item |
c906108c | 13762 | @emph{Integral types} include @code{int} with any of its storage-class |
b37052ae | 13763 | specifiers; @code{char}; @code{enum}; and, for C@t{++}, @code{bool}. |
c906108c SS |
13764 | |
13765 | @item | |
d4f3574e SS |
13766 | @emph{Floating-point types} include @code{float}, @code{double}, and |
13767 | @code{long double} (if supported by the target platform). | |
c906108c SS |
13768 | |
13769 | @item | |
53a5351d | 13770 | @emph{Pointer types} include all types defined as @code{(@var{type} *)}. |
c906108c SS |
13771 | |
13772 | @item | |
13773 | @emph{Scalar types} include all of the above. | |
53a5351d | 13774 | |
c906108c SS |
13775 | @end itemize |
13776 | ||
13777 | @noindent | |
13778 | The following operators are supported. They are listed here | |
13779 | in order of increasing precedence: | |
13780 | ||
13781 | @table @code | |
13782 | @item , | |
13783 | The comma or sequencing operator. Expressions in a comma-separated list | |
13784 | are evaluated from left to right, with the result of the entire | |
13785 | expression being the last expression evaluated. | |
13786 | ||
13787 | @item = | |
13788 | Assignment. The value of an assignment expression is the value | |
13789 | assigned. Defined on scalar types. | |
13790 | ||
13791 | @item @var{op}= | |
13792 | Used in an expression of the form @w{@code{@var{a} @var{op}= @var{b}}}, | |
13793 | and translated to @w{@code{@var{a} = @var{a op b}}}. | |
697aa1b7 | 13794 | @w{@code{@var{op}=}} and @code{=} have the same precedence. The operator |
c906108c SS |
13795 | @var{op} is any one of the operators @code{|}, @code{^}, @code{&}, |
13796 | @code{<<}, @code{>>}, @code{+}, @code{-}, @code{*}, @code{/}, @code{%}. | |
13797 | ||
13798 | @item ?: | |
13799 | The ternary operator. @code{@var{a} ? @var{b} : @var{c}} can be thought | |
697aa1b7 EZ |
13800 | of as: if @var{a} then @var{b} else @var{c}. The argument @var{a} |
13801 | should be of an integral type. | |
c906108c SS |
13802 | |
13803 | @item || | |
13804 | Logical @sc{or}. Defined on integral types. | |
13805 | ||
13806 | @item && | |
13807 | Logical @sc{and}. Defined on integral types. | |
13808 | ||
13809 | @item | | |
13810 | Bitwise @sc{or}. Defined on integral types. | |
13811 | ||
13812 | @item ^ | |
13813 | Bitwise exclusive-@sc{or}. Defined on integral types. | |
13814 | ||
13815 | @item & | |
13816 | Bitwise @sc{and}. Defined on integral types. | |
13817 | ||
13818 | @item ==@r{, }!= | |
13819 | Equality and inequality. Defined on scalar types. The value of these | |
13820 | expressions is 0 for false and non-zero for true. | |
13821 | ||
13822 | @item <@r{, }>@r{, }<=@r{, }>= | |
13823 | Less than, greater than, less than or equal, greater than or equal. | |
13824 | Defined on scalar types. The value of these expressions is 0 for false | |
13825 | and non-zero for true. | |
13826 | ||
13827 | @item <<@r{, }>> | |
13828 | left shift, and right shift. Defined on integral types. | |
13829 | ||
13830 | @item @@ | |
13831 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
13832 | ||
13833 | @item +@r{, }- | |
13834 | Addition and subtraction. Defined on integral types, floating-point types and | |
13835 | pointer types. | |
13836 | ||
13837 | @item *@r{, }/@r{, }% | |
13838 | Multiplication, division, and modulus. Multiplication and division are | |
13839 | defined on integral and floating-point types. Modulus is defined on | |
13840 | integral types. | |
13841 | ||
13842 | @item ++@r{, }-- | |
13843 | Increment and decrement. When appearing before a variable, the | |
13844 | operation is performed before the variable is used in an expression; | |
13845 | when appearing after it, the variable's value is used before the | |
13846 | operation takes place. | |
13847 | ||
13848 | @item * | |
13849 | Pointer dereferencing. Defined on pointer types. Same precedence as | |
13850 | @code{++}. | |
13851 | ||
13852 | @item & | |
13853 | Address operator. Defined on variables. Same precedence as @code{++}. | |
13854 | ||
b37052ae EZ |
13855 | For debugging C@t{++}, @value{GDBN} implements a use of @samp{&} beyond what is |
13856 | allowed in the C@t{++} language itself: you can use @samp{&(&@var{ref})} | |
b17828ca | 13857 | to examine the address |
b37052ae | 13858 | where a C@t{++} reference variable (declared with @samp{&@var{ref}}) is |
c906108c | 13859 | stored. |
c906108c SS |
13860 | |
13861 | @item - | |
13862 | Negative. Defined on integral and floating-point types. Same | |
13863 | precedence as @code{++}. | |
13864 | ||
13865 | @item ! | |
13866 | Logical negation. Defined on integral types. Same precedence as | |
13867 | @code{++}. | |
13868 | ||
13869 | @item ~ | |
13870 | Bitwise complement operator. Defined on integral types. Same precedence as | |
13871 | @code{++}. | |
13872 | ||
13873 | ||
13874 | @item .@r{, }-> | |
13875 | Structure member, and pointer-to-structure member. For convenience, | |
13876 | @value{GDBN} regards the two as equivalent, choosing whether to dereference a | |
13877 | pointer based on the stored type information. | |
13878 | Defined on @code{struct} and @code{union} data. | |
13879 | ||
c906108c SS |
13880 | @item .*@r{, }->* |
13881 | Dereferences of pointers to members. | |
c906108c SS |
13882 | |
13883 | @item [] | |
13884 | Array indexing. @code{@var{a}[@var{i}]} is defined as | |
13885 | @code{*(@var{a}+@var{i})}. Same precedence as @code{->}. | |
13886 | ||
13887 | @item () | |
13888 | Function parameter list. Same precedence as @code{->}. | |
13889 | ||
c906108c | 13890 | @item :: |
b37052ae | 13891 | C@t{++} scope resolution operator. Defined on @code{struct}, @code{union}, |
7a292a7a | 13892 | and @code{class} types. |
c906108c SS |
13893 | |
13894 | @item :: | |
7a292a7a SS |
13895 | Doubled colons also represent the @value{GDBN} scope operator |
13896 | (@pxref{Expressions, ,Expressions}). Same precedence as @code{::}, | |
13897 | above. | |
c906108c SS |
13898 | @end table |
13899 | ||
c906108c SS |
13900 | If an operator is redefined in the user code, @value{GDBN} usually |
13901 | attempts to invoke the redefined version instead of using the operator's | |
13902 | predefined meaning. | |
c906108c | 13903 | |
6d2ebf8b | 13904 | @node C Constants |
79a6e687 | 13905 | @subsubsection C and C@t{++} Constants |
c906108c | 13906 | |
b37052ae | 13907 | @cindex C and C@t{++} constants |
c906108c | 13908 | |
b37052ae | 13909 | @value{GDBN} allows you to express the constants of C and C@t{++} in the |
c906108c | 13910 | following ways: |
c906108c SS |
13911 | |
13912 | @itemize @bullet | |
13913 | @item | |
13914 | Integer constants are a sequence of digits. Octal constants are | |
6ca652b0 EZ |
13915 | specified by a leading @samp{0} (i.e.@: zero), and hexadecimal constants |
13916 | by a leading @samp{0x} or @samp{0X}. Constants may also end with a letter | |
c906108c SS |
13917 | @samp{l}, specifying that the constant should be treated as a |
13918 | @code{long} value. | |
13919 | ||
13920 | @item | |
13921 | Floating point constants are a sequence of digits, followed by a decimal | |
13922 | point, followed by a sequence of digits, and optionally followed by an | |
13923 | exponent. An exponent is of the form: | |
13924 | @samp{@w{e@r{[[}+@r{]|}-@r{]}@var{nnn}}}, where @var{nnn} is another | |
13925 | sequence of digits. The @samp{+} is optional for positive exponents. | |
d4f3574e SS |
13926 | A floating-point constant may also end with a letter @samp{f} or |
13927 | @samp{F}, specifying that the constant should be treated as being of | |
13928 | the @code{float} (as opposed to the default @code{double}) type; or with | |
13929 | a letter @samp{l} or @samp{L}, which specifies a @code{long double} | |
13930 | constant. | |
c906108c SS |
13931 | |
13932 | @item | |
13933 | Enumerated constants consist of enumerated identifiers, or their | |
13934 | integral equivalents. | |
13935 | ||
13936 | @item | |
13937 | Character constants are a single character surrounded by single quotes | |
13938 | (@code{'}), or a number---the ordinal value of the corresponding character | |
d4f3574e | 13939 | (usually its @sc{ascii} value). Within quotes, the single character may |
c906108c SS |
13940 | be represented by a letter or by @dfn{escape sequences}, which are of |
13941 | the form @samp{\@var{nnn}}, where @var{nnn} is the octal representation | |
13942 | of the character's ordinal value; or of the form @samp{\@var{x}}, where | |
13943 | @samp{@var{x}} is a predefined special character---for example, | |
13944 | @samp{\n} for newline. | |
13945 | ||
e0f8f636 TT |
13946 | Wide character constants can be written by prefixing a character |
13947 | constant with @samp{L}, as in C. For example, @samp{L'x'} is the wide | |
13948 | form of @samp{x}. The target wide character set is used when | |
13949 | computing the value of this constant (@pxref{Character Sets}). | |
13950 | ||
c906108c | 13951 | @item |
96a2c332 SS |
13952 | String constants are a sequence of character constants surrounded by |
13953 | double quotes (@code{"}). Any valid character constant (as described | |
13954 | above) may appear. Double quotes within the string must be preceded by | |
13955 | a backslash, so for instance @samp{"a\"b'c"} is a string of five | |
13956 | characters. | |
c906108c | 13957 | |
e0f8f636 TT |
13958 | Wide string constants can be written by prefixing a string constant |
13959 | with @samp{L}, as in C. The target wide character set is used when | |
13960 | computing the value of this constant (@pxref{Character Sets}). | |
13961 | ||
c906108c SS |
13962 | @item |
13963 | Pointer constants are an integral value. You can also write pointers | |
13964 | to constants using the C operator @samp{&}. | |
13965 | ||
13966 | @item | |
13967 | Array constants are comma-separated lists surrounded by braces @samp{@{} | |
13968 | and @samp{@}}; for example, @samp{@{1,2,3@}} is a three-element array of | |
13969 | integers, @samp{@{@{1,2@}, @{3,4@}, @{5,6@}@}} is a three-by-two array, | |
13970 | and @samp{@{&"hi", &"there", &"fred"@}} is a three-element array of pointers. | |
13971 | @end itemize | |
13972 | ||
79a6e687 BW |
13973 | @node C Plus Plus Expressions |
13974 | @subsubsection C@t{++} Expressions | |
b37052ae EZ |
13975 | |
13976 | @cindex expressions in C@t{++} | |
13977 | @value{GDBN} expression handling can interpret most C@t{++} expressions. | |
13978 | ||
0179ffac DC |
13979 | @cindex debugging C@t{++} programs |
13980 | @cindex C@t{++} compilers | |
13981 | @cindex debug formats and C@t{++} | |
13982 | @cindex @value{NGCC} and C@t{++} | |
c906108c | 13983 | @quotation |
e0f8f636 TT |
13984 | @emph{Warning:} @value{GDBN} can only debug C@t{++} code if you use |
13985 | the proper compiler and the proper debug format. Currently, | |
13986 | @value{GDBN} works best when debugging C@t{++} code that is compiled | |
13987 | with the most recent version of @value{NGCC} possible. The DWARF | |
13988 | debugging format is preferred; @value{NGCC} defaults to this on most | |
13989 | popular platforms. Other compilers and/or debug formats are likely to | |
13990 | work badly or not at all when using @value{GDBN} to debug C@t{++} | |
13991 | code. @xref{Compilation}. | |
c906108c | 13992 | @end quotation |
c906108c SS |
13993 | |
13994 | @enumerate | |
13995 | ||
13996 | @cindex member functions | |
13997 | @item | |
13998 | Member function calls are allowed; you can use expressions like | |
13999 | ||
474c8240 | 14000 | @smallexample |
c906108c | 14001 | count = aml->GetOriginal(x, y) |
474c8240 | 14002 | @end smallexample |
c906108c | 14003 | |
41afff9a | 14004 | @vindex this@r{, inside C@t{++} member functions} |
b37052ae | 14005 | @cindex namespace in C@t{++} |
c906108c SS |
14006 | @item |
14007 | While a member function is active (in the selected stack frame), your | |
14008 | expressions have the same namespace available as the member function; | |
14009 | that is, @value{GDBN} allows implicit references to the class instance | |
e0f8f636 TT |
14010 | pointer @code{this} following the same rules as C@t{++}. @code{using} |
14011 | declarations in the current scope are also respected by @value{GDBN}. | |
c906108c | 14012 | |
c906108c | 14013 | @cindex call overloaded functions |
d4f3574e | 14014 | @cindex overloaded functions, calling |
b37052ae | 14015 | @cindex type conversions in C@t{++} |
c906108c SS |
14016 | @item |
14017 | You can call overloaded functions; @value{GDBN} resolves the function | |
d4f3574e | 14018 | call to the right definition, with some restrictions. @value{GDBN} does not |
c906108c SS |
14019 | perform overload resolution involving user-defined type conversions, |
14020 | calls to constructors, or instantiations of templates that do not exist | |
14021 | in the program. It also cannot handle ellipsis argument lists or | |
14022 | default arguments. | |
14023 | ||
14024 | It does perform integral conversions and promotions, floating-point | |
14025 | promotions, arithmetic conversions, pointer conversions, conversions of | |
14026 | class objects to base classes, and standard conversions such as those of | |
14027 | functions or arrays to pointers; it requires an exact match on the | |
14028 | number of function arguments. | |
14029 | ||
14030 | Overload resolution is always performed, unless you have specified | |
79a6e687 BW |
14031 | @code{set overload-resolution off}. @xref{Debugging C Plus Plus, |
14032 | ,@value{GDBN} Features for C@t{++}}. | |
c906108c | 14033 | |
d4f3574e | 14034 | You must specify @code{set overload-resolution off} in order to use an |
c906108c SS |
14035 | explicit function signature to call an overloaded function, as in |
14036 | @smallexample | |
14037 | p 'foo(char,int)'('x', 13) | |
14038 | @end smallexample | |
d4f3574e | 14039 | |
c906108c | 14040 | The @value{GDBN} command-completion facility can simplify this; |
79a6e687 | 14041 | see @ref{Completion, ,Command Completion}. |
c906108c | 14042 | |
c906108c SS |
14043 | @cindex reference declarations |
14044 | @item | |
b37052ae EZ |
14045 | @value{GDBN} understands variables declared as C@t{++} references; you can use |
14046 | them in expressions just as you do in C@t{++} source---they are automatically | |
c906108c SS |
14047 | dereferenced. |
14048 | ||
14049 | In the parameter list shown when @value{GDBN} displays a frame, the values of | |
14050 | reference variables are not displayed (unlike other variables); this | |
14051 | avoids clutter, since references are often used for large structures. | |
14052 | The @emph{address} of a reference variable is always shown, unless | |
14053 | you have specified @samp{set print address off}. | |
14054 | ||
14055 | @item | |
b37052ae | 14056 | @value{GDBN} supports the C@t{++} name resolution operator @code{::}---your |
c906108c SS |
14057 | expressions can use it just as expressions in your program do. Since |
14058 | one scope may be defined in another, you can use @code{::} repeatedly if | |
14059 | necessary, for example in an expression like | |
14060 | @samp{@var{scope1}::@var{scope2}::@var{name}}. @value{GDBN} also allows | |
b37052ae | 14061 | resolving name scope by reference to source files, in both C and C@t{++} |
79a6e687 | 14062 | debugging (@pxref{Variables, ,Program Variables}). |
c906108c | 14063 | |
e0f8f636 TT |
14064 | @item |
14065 | @value{GDBN} performs argument-dependent lookup, following the C@t{++} | |
14066 | specification. | |
14067 | @end enumerate | |
c906108c | 14068 | |
6d2ebf8b | 14069 | @node C Defaults |
79a6e687 | 14070 | @subsubsection C and C@t{++} Defaults |
7a292a7a | 14071 | |
b37052ae | 14072 | @cindex C and C@t{++} defaults |
c906108c | 14073 | |
a451cb65 KS |
14074 | If you allow @value{GDBN} to set range checking automatically, it |
14075 | defaults to @code{off} whenever the working language changes to | |
b37052ae | 14076 | C or C@t{++}. This happens regardless of whether you or @value{GDBN} |
c906108c | 14077 | selects the working language. |
c906108c SS |
14078 | |
14079 | If you allow @value{GDBN} to set the language automatically, it | |
14080 | recognizes source files whose names end with @file{.c}, @file{.C}, or | |
14081 | @file{.cc}, etc, and when @value{GDBN} enters code compiled from one of | |
b37052ae | 14082 | these files, it sets the working language to C or C@t{++}. |
79a6e687 | 14083 | @xref{Automatically, ,Having @value{GDBN} Infer the Source Language}, |
c906108c SS |
14084 | for further details. |
14085 | ||
6d2ebf8b | 14086 | @node C Checks |
79a6e687 | 14087 | @subsubsection C and C@t{++} Type and Range Checks |
7a292a7a | 14088 | |
b37052ae | 14089 | @cindex C and C@t{++} checks |
c906108c | 14090 | |
a451cb65 KS |
14091 | By default, when @value{GDBN} parses C or C@t{++} expressions, strict type |
14092 | checking is used. However, if you turn type checking off, @value{GDBN} | |
14093 | will allow certain non-standard conversions, such as promoting integer | |
14094 | constants to pointers. | |
c906108c SS |
14095 | |
14096 | Range checking, if turned on, is done on mathematical operations. Array | |
14097 | indices are not checked, since they are often used to index a pointer | |
14098 | that is not itself an array. | |
c906108c | 14099 | |
6d2ebf8b | 14100 | @node Debugging C |
c906108c | 14101 | @subsubsection @value{GDBN} and C |
c906108c SS |
14102 | |
14103 | The @code{set print union} and @code{show print union} commands apply to | |
14104 | the @code{union} type. When set to @samp{on}, any @code{union} that is | |
7a292a7a SS |
14105 | inside a @code{struct} or @code{class} is also printed. Otherwise, it |
14106 | appears as @samp{@{...@}}. | |
c906108c SS |
14107 | |
14108 | The @code{@@} operator aids in the debugging of dynamic arrays, formed | |
14109 | with pointers and a memory allocation function. @xref{Expressions, | |
14110 | ,Expressions}. | |
14111 | ||
79a6e687 BW |
14112 | @node Debugging C Plus Plus |
14113 | @subsubsection @value{GDBN} Features for C@t{++} | |
c906108c | 14114 | |
b37052ae | 14115 | @cindex commands for C@t{++} |
7a292a7a | 14116 | |
b37052ae EZ |
14117 | Some @value{GDBN} commands are particularly useful with C@t{++}, and some are |
14118 | designed specifically for use with C@t{++}. Here is a summary: | |
c906108c SS |
14119 | |
14120 | @table @code | |
14121 | @cindex break in overloaded functions | |
14122 | @item @r{breakpoint menus} | |
14123 | When you want a breakpoint in a function whose name is overloaded, | |
6ba66d6a JB |
14124 | @value{GDBN} has the capability to display a menu of possible breakpoint |
14125 | locations to help you specify which function definition you want. | |
14126 | @xref{Ambiguous Expressions,,Ambiguous Expressions}. | |
c906108c | 14127 | |
b37052ae | 14128 | @cindex overloading in C@t{++} |
c906108c SS |
14129 | @item rbreak @var{regex} |
14130 | Setting breakpoints using regular expressions is helpful for setting | |
14131 | breakpoints on overloaded functions that are not members of any special | |
14132 | classes. | |
79a6e687 | 14133 | @xref{Set Breaks, ,Setting Breakpoints}. |
c906108c | 14134 | |
b37052ae | 14135 | @cindex C@t{++} exception handling |
c906108c | 14136 | @item catch throw |
591f19e8 | 14137 | @itemx catch rethrow |
c906108c | 14138 | @itemx catch catch |
b37052ae | 14139 | Debug C@t{++} exception handling using these commands. @xref{Set |
79a6e687 | 14140 | Catchpoints, , Setting Catchpoints}. |
c906108c SS |
14141 | |
14142 | @cindex inheritance | |
14143 | @item ptype @var{typename} | |
14144 | Print inheritance relationships as well as other information for type | |
14145 | @var{typename}. | |
14146 | @xref{Symbols, ,Examining the Symbol Table}. | |
14147 | ||
c4aeac85 TT |
14148 | @item info vtbl @var{expression}. |
14149 | The @code{info vtbl} command can be used to display the virtual | |
14150 | method tables of the object computed by @var{expression}. This shows | |
14151 | one entry per virtual table; there may be multiple virtual tables when | |
14152 | multiple inheritance is in use. | |
14153 | ||
b37052ae | 14154 | @cindex C@t{++} symbol display |
c906108c SS |
14155 | @item set print demangle |
14156 | @itemx show print demangle | |
14157 | @itemx set print asm-demangle | |
14158 | @itemx show print asm-demangle | |
b37052ae EZ |
14159 | Control whether C@t{++} symbols display in their source form, both when |
14160 | displaying code as C@t{++} source and when displaying disassemblies. | |
79a6e687 | 14161 | @xref{Print Settings, ,Print Settings}. |
c906108c SS |
14162 | |
14163 | @item set print object | |
14164 | @itemx show print object | |
14165 | Choose whether to print derived (actual) or declared types of objects. | |
79a6e687 | 14166 | @xref{Print Settings, ,Print Settings}. |
c906108c SS |
14167 | |
14168 | @item set print vtbl | |
14169 | @itemx show print vtbl | |
14170 | Control the format for printing virtual function tables. | |
79a6e687 | 14171 | @xref{Print Settings, ,Print Settings}. |
c906108c | 14172 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 14173 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
14174 | |
14175 | @kindex set overload-resolution | |
d4f3574e | 14176 | @cindex overloaded functions, overload resolution |
c906108c | 14177 | @item set overload-resolution on |
b37052ae | 14178 | Enable overload resolution for C@t{++} expression evaluation. The default |
c906108c SS |
14179 | is on. For overloaded functions, @value{GDBN} evaluates the arguments |
14180 | and searches for a function whose signature matches the argument types, | |
79a6e687 BW |
14181 | using the standard C@t{++} conversion rules (see @ref{C Plus Plus |
14182 | Expressions, ,C@t{++} Expressions}, for details). | |
14183 | If it cannot find a match, it emits a message. | |
c906108c SS |
14184 | |
14185 | @item set overload-resolution off | |
b37052ae | 14186 | Disable overload resolution for C@t{++} expression evaluation. For |
c906108c SS |
14187 | overloaded functions that are not class member functions, @value{GDBN} |
14188 | chooses the first function of the specified name that it finds in the | |
14189 | symbol table, whether or not its arguments are of the correct type. For | |
14190 | overloaded functions that are class member functions, @value{GDBN} | |
14191 | searches for a function whose signature @emph{exactly} matches the | |
14192 | argument types. | |
c906108c | 14193 | |
9c16f35a EZ |
14194 | @kindex show overload-resolution |
14195 | @item show overload-resolution | |
14196 | Show the current setting of overload resolution. | |
14197 | ||
c906108c SS |
14198 | @item @r{Overloaded symbol names} |
14199 | You can specify a particular definition of an overloaded symbol, using | |
b37052ae | 14200 | the same notation that is used to declare such symbols in C@t{++}: type |
c906108c SS |
14201 | @code{@var{symbol}(@var{types})} rather than just @var{symbol}. You can |
14202 | also use the @value{GDBN} command-line word completion facilities to list the | |
14203 | available choices, or to finish the type list for you. | |
79a6e687 | 14204 | @xref{Completion,, Command Completion}, for details on how to do this. |
c906108c | 14205 | @end table |
c906108c | 14206 | |
febe4383 TJB |
14207 | @node Decimal Floating Point |
14208 | @subsubsection Decimal Floating Point format | |
14209 | @cindex decimal floating point format | |
14210 | ||
14211 | @value{GDBN} can examine, set and perform computations with numbers in | |
14212 | decimal floating point format, which in the C language correspond to the | |
14213 | @code{_Decimal32}, @code{_Decimal64} and @code{_Decimal128} types as | |
14214 | specified by the extension to support decimal floating-point arithmetic. | |
14215 | ||
14216 | There are two encodings in use, depending on the architecture: BID (Binary | |
14217 | Integer Decimal) for x86 and x86-64, and DPD (Densely Packed Decimal) for | |
4ac33720 UW |
14218 | PowerPC and S/390. @value{GDBN} will use the appropriate encoding for the |
14219 | configured target. | |
febe4383 TJB |
14220 | |
14221 | Because of a limitation in @file{libdecnumber}, the library used by @value{GDBN} | |
14222 | to manipulate decimal floating point numbers, it is not possible to convert | |
14223 | (using a cast, for example) integers wider than 32-bit to decimal float. | |
14224 | ||
14225 | In addition, in order to imitate @value{GDBN}'s behaviour with binary floating | |
14226 | point computations, error checking in decimal float operations ignores | |
14227 | underflow, overflow and divide by zero exceptions. | |
14228 | ||
4acd40f3 | 14229 | In the PowerPC architecture, @value{GDBN} provides a set of pseudo-registers |
99e008fe EZ |
14230 | to inspect @code{_Decimal128} values stored in floating point registers. |
14231 | See @ref{PowerPC,,PowerPC} for more details. | |
4acd40f3 | 14232 | |
6aecb9c2 JB |
14233 | @node D |
14234 | @subsection D | |
14235 | ||
14236 | @cindex D | |
14237 | @value{GDBN} can be used to debug programs written in D and compiled with | |
14238 | GDC, LDC or DMD compilers. Currently @value{GDBN} supports only one D | |
14239 | specific feature --- dynamic arrays. | |
14240 | ||
a766d390 DE |
14241 | @node Go |
14242 | @subsection Go | |
14243 | ||
14244 | @cindex Go (programming language) | |
14245 | @value{GDBN} can be used to debug programs written in Go and compiled with | |
14246 | @file{gccgo} or @file{6g} compilers. | |
14247 | ||
14248 | Here is a summary of the Go-specific features and restrictions: | |
14249 | ||
14250 | @table @code | |
14251 | @cindex current Go package | |
14252 | @item The current Go package | |
14253 | The name of the current package does not need to be specified when | |
14254 | specifying global variables and functions. | |
14255 | ||
14256 | For example, given the program: | |
14257 | ||
14258 | @example | |
14259 | package main | |
14260 | var myglob = "Shall we?" | |
14261 | func main () @{ | |
14262 | // ... | |
14263 | @} | |
14264 | @end example | |
14265 | ||
14266 | When stopped inside @code{main} either of these work: | |
14267 | ||
14268 | @example | |
14269 | (gdb) p myglob | |
14270 | (gdb) p main.myglob | |
14271 | @end example | |
14272 | ||
14273 | @cindex builtin Go types | |
14274 | @item Builtin Go types | |
14275 | The @code{string} type is recognized by @value{GDBN} and is printed | |
14276 | as a string. | |
14277 | ||
14278 | @cindex builtin Go functions | |
14279 | @item Builtin Go functions | |
14280 | The @value{GDBN} expression parser recognizes the @code{unsafe.Sizeof} | |
14281 | function and handles it internally. | |
a766d390 DE |
14282 | |
14283 | @cindex restrictions on Go expressions | |
14284 | @item Restrictions on Go expressions | |
14285 | All Go operators are supported except @code{&^}. | |
14286 | The Go @code{_} ``blank identifier'' is not supported. | |
14287 | Automatic dereferencing of pointers is not supported. | |
50f042b9 | 14288 | @end table |
a766d390 | 14289 | |
b37303ee AF |
14290 | @node Objective-C |
14291 | @subsection Objective-C | |
14292 | ||
14293 | @cindex Objective-C | |
14294 | This section provides information about some commands and command | |
721c2651 EZ |
14295 | options that are useful for debugging Objective-C code. See also |
14296 | @ref{Symbols, info classes}, and @ref{Symbols, info selectors}, for a | |
14297 | few more commands specific to Objective-C support. | |
b37303ee AF |
14298 | |
14299 | @menu | |
b383017d RM |
14300 | * Method Names in Commands:: |
14301 | * The Print Command with Objective-C:: | |
b37303ee AF |
14302 | @end menu |
14303 | ||
c8f4133a | 14304 | @node Method Names in Commands |
b37303ee AF |
14305 | @subsubsection Method Names in Commands |
14306 | ||
14307 | The following commands have been extended to accept Objective-C method | |
14308 | names as line specifications: | |
14309 | ||
14310 | @kindex clear@r{, and Objective-C} | |
14311 | @kindex break@r{, and Objective-C} | |
14312 | @kindex info line@r{, and Objective-C} | |
14313 | @kindex jump@r{, and Objective-C} | |
14314 | @kindex list@r{, and Objective-C} | |
14315 | @itemize | |
14316 | @item @code{clear} | |
14317 | @item @code{break} | |
14318 | @item @code{info line} | |
14319 | @item @code{jump} | |
14320 | @item @code{list} | |
14321 | @end itemize | |
14322 | ||
14323 | A fully qualified Objective-C method name is specified as | |
14324 | ||
14325 | @smallexample | |
14326 | -[@var{Class} @var{methodName}] | |
14327 | @end smallexample | |
14328 | ||
c552b3bb JM |
14329 | where the minus sign is used to indicate an instance method and a |
14330 | plus sign (not shown) is used to indicate a class method. The class | |
14331 | name @var{Class} and method name @var{methodName} are enclosed in | |
14332 | brackets, similar to the way messages are specified in Objective-C | |
14333 | source code. For example, to set a breakpoint at the @code{create} | |
14334 | instance method of class @code{Fruit} in the program currently being | |
14335 | debugged, enter: | |
b37303ee AF |
14336 | |
14337 | @smallexample | |
14338 | break -[Fruit create] | |
14339 | @end smallexample | |
14340 | ||
14341 | To list ten program lines around the @code{initialize} class method, | |
14342 | enter: | |
14343 | ||
14344 | @smallexample | |
14345 | list +[NSText initialize] | |
14346 | @end smallexample | |
14347 | ||
c552b3bb JM |
14348 | In the current version of @value{GDBN}, the plus or minus sign is |
14349 | required. In future versions of @value{GDBN}, the plus or minus | |
14350 | sign will be optional, but you can use it to narrow the search. It | |
14351 | is also possible to specify just a method name: | |
b37303ee AF |
14352 | |
14353 | @smallexample | |
14354 | break create | |
14355 | @end smallexample | |
14356 | ||
14357 | You must specify the complete method name, including any colons. If | |
14358 | your program's source files contain more than one @code{create} method, | |
14359 | you'll be presented with a numbered list of classes that implement that | |
14360 | method. Indicate your choice by number, or type @samp{0} to exit if | |
14361 | none apply. | |
14362 | ||
14363 | As another example, to clear a breakpoint established at the | |
14364 | @code{makeKeyAndOrderFront:} method of the @code{NSWindow} class, enter: | |
14365 | ||
14366 | @smallexample | |
14367 | clear -[NSWindow makeKeyAndOrderFront:] | |
14368 | @end smallexample | |
14369 | ||
14370 | @node The Print Command with Objective-C | |
14371 | @subsubsection The Print Command With Objective-C | |
721c2651 | 14372 | @cindex Objective-C, print objects |
c552b3bb JM |
14373 | @kindex print-object |
14374 | @kindex po @r{(@code{print-object})} | |
b37303ee | 14375 | |
c552b3bb | 14376 | The print command has also been extended to accept methods. For example: |
b37303ee AF |
14377 | |
14378 | @smallexample | |
c552b3bb | 14379 | print -[@var{object} hash] |
b37303ee AF |
14380 | @end smallexample |
14381 | ||
14382 | @cindex print an Objective-C object description | |
c552b3bb JM |
14383 | @cindex @code{_NSPrintForDebugger}, and printing Objective-C objects |
14384 | @noindent | |
14385 | will tell @value{GDBN} to send the @code{hash} message to @var{object} | |
14386 | and print the result. Also, an additional command has been added, | |
14387 | @code{print-object} or @code{po} for short, which is meant to print | |
14388 | the description of an object. However, this command may only work | |
14389 | with certain Objective-C libraries that have a particular hook | |
14390 | function, @code{_NSPrintForDebugger}, defined. | |
b37303ee | 14391 | |
f4b8a18d KW |
14392 | @node OpenCL C |
14393 | @subsection OpenCL C | |
14394 | ||
14395 | @cindex OpenCL C | |
14396 | This section provides information about @value{GDBN}s OpenCL C support. | |
14397 | ||
14398 | @menu | |
14399 | * OpenCL C Datatypes:: | |
14400 | * OpenCL C Expressions:: | |
14401 | * OpenCL C Operators:: | |
14402 | @end menu | |
14403 | ||
14404 | @node OpenCL C Datatypes | |
14405 | @subsubsection OpenCL C Datatypes | |
14406 | ||
14407 | @cindex OpenCL C Datatypes | |
14408 | @value{GDBN} supports the builtin scalar and vector datatypes specified | |
14409 | by OpenCL 1.1. In addition the half- and double-precision floating point | |
14410 | data types of the @code{cl_khr_fp16} and @code{cl_khr_fp64} OpenCL | |
14411 | extensions are also known to @value{GDBN}. | |
14412 | ||
14413 | @node OpenCL C Expressions | |
14414 | @subsubsection OpenCL C Expressions | |
14415 | ||
14416 | @cindex OpenCL C Expressions | |
14417 | @value{GDBN} supports accesses to vector components including the access as | |
14418 | lvalue where possible. Since OpenCL C is based on C99 most C expressions | |
14419 | supported by @value{GDBN} can be used as well. | |
14420 | ||
14421 | @node OpenCL C Operators | |
14422 | @subsubsection OpenCL C Operators | |
14423 | ||
14424 | @cindex OpenCL C Operators | |
14425 | @value{GDBN} supports the operators specified by OpenCL 1.1 for scalar and | |
14426 | vector data types. | |
14427 | ||
09d4efe1 EZ |
14428 | @node Fortran |
14429 | @subsection Fortran | |
14430 | @cindex Fortran-specific support in @value{GDBN} | |
14431 | ||
814e32d7 WZ |
14432 | @value{GDBN} can be used to debug programs written in Fortran, but it |
14433 | currently supports only the features of Fortran 77 language. | |
14434 | ||
14435 | @cindex trailing underscore, in Fortran symbols | |
14436 | Some Fortran compilers (@sc{gnu} Fortran 77 and Fortran 95 compilers | |
14437 | among them) append an underscore to the names of variables and | |
14438 | functions. When you debug programs compiled by those compilers, you | |
14439 | will need to refer to variables and functions with a trailing | |
14440 | underscore. | |
14441 | ||
14442 | @menu | |
14443 | * Fortran Operators:: Fortran operators and expressions | |
14444 | * Fortran Defaults:: Default settings for Fortran | |
79a6e687 | 14445 | * Special Fortran Commands:: Special @value{GDBN} commands for Fortran |
814e32d7 WZ |
14446 | @end menu |
14447 | ||
14448 | @node Fortran Operators | |
79a6e687 | 14449 | @subsubsection Fortran Operators and Expressions |
814e32d7 WZ |
14450 | |
14451 | @cindex Fortran operators and expressions | |
14452 | ||
14453 | Operators must be defined on values of specific types. For instance, | |
14454 | @code{+} is defined on numbers, but not on characters or other non- | |
ff2587ec | 14455 | arithmetic types. Operators are often defined on groups of types. |
814e32d7 WZ |
14456 | |
14457 | @table @code | |
14458 | @item ** | |
99e008fe | 14459 | The exponentiation operator. It raises the first operand to the power |
814e32d7 WZ |
14460 | of the second one. |
14461 | ||
14462 | @item : | |
14463 | The range operator. Normally used in the form of array(low:high) to | |
14464 | represent a section of array. | |
68837c9d MD |
14465 | |
14466 | @item % | |
14467 | The access component operator. Normally used to access elements in derived | |
14468 | types. Also suitable for unions. As unions aren't part of regular Fortran, | |
14469 | this can only happen when accessing a register that uses a gdbarch-defined | |
14470 | union type. | |
814e32d7 WZ |
14471 | @end table |
14472 | ||
14473 | @node Fortran Defaults | |
14474 | @subsubsection Fortran Defaults | |
14475 | ||
14476 | @cindex Fortran Defaults | |
14477 | ||
14478 | Fortran symbols are usually case-insensitive, so @value{GDBN} by | |
14479 | default uses case-insensitive matches for Fortran symbols. You can | |
14480 | change that with the @samp{set case-insensitive} command, see | |
14481 | @ref{Symbols}, for the details. | |
14482 | ||
79a6e687 BW |
14483 | @node Special Fortran Commands |
14484 | @subsubsection Special Fortran Commands | |
814e32d7 WZ |
14485 | |
14486 | @cindex Special Fortran commands | |
14487 | ||
db2e3e2e BW |
14488 | @value{GDBN} has some commands to support Fortran-specific features, |
14489 | such as displaying common blocks. | |
814e32d7 | 14490 | |
09d4efe1 EZ |
14491 | @table @code |
14492 | @cindex @code{COMMON} blocks, Fortran | |
14493 | @kindex info common | |
14494 | @item info common @r{[}@var{common-name}@r{]} | |
14495 | This command prints the values contained in the Fortran @code{COMMON} | |
14496 | block whose name is @var{common-name}. With no argument, the names of | |
d52fb0e9 | 14497 | all @code{COMMON} blocks visible at the current program location are |
09d4efe1 EZ |
14498 | printed. |
14499 | @end table | |
14500 | ||
9c16f35a EZ |
14501 | @node Pascal |
14502 | @subsection Pascal | |
14503 | ||
14504 | @cindex Pascal support in @value{GDBN}, limitations | |
14505 | Debugging Pascal programs which use sets, subranges, file variables, or | |
14506 | nested functions does not currently work. @value{GDBN} does not support | |
14507 | entering expressions, printing values, or similar features using Pascal | |
14508 | syntax. | |
14509 | ||
14510 | The Pascal-specific command @code{set print pascal_static-members} | |
14511 | controls whether static members of Pascal objects are displayed. | |
14512 | @xref{Print Settings, pascal_static-members}. | |
14513 | ||
09d4efe1 | 14514 | @node Modula-2 |
c906108c | 14515 | @subsection Modula-2 |
7a292a7a | 14516 | |
d4f3574e | 14517 | @cindex Modula-2, @value{GDBN} support |
c906108c SS |
14518 | |
14519 | The extensions made to @value{GDBN} to support Modula-2 only support | |
14520 | output from the @sc{gnu} Modula-2 compiler (which is currently being | |
14521 | developed). Other Modula-2 compilers are not currently supported, and | |
14522 | attempting to debug executables produced by them is most likely | |
14523 | to give an error as @value{GDBN} reads in the executable's symbol | |
14524 | table. | |
14525 | ||
14526 | @cindex expressions in Modula-2 | |
14527 | @menu | |
14528 | * M2 Operators:: Built-in operators | |
14529 | * Built-In Func/Proc:: Built-in functions and procedures | |
14530 | * M2 Constants:: Modula-2 constants | |
72019c9c | 14531 | * M2 Types:: Modula-2 types |
c906108c SS |
14532 | * M2 Defaults:: Default settings for Modula-2 |
14533 | * Deviations:: Deviations from standard Modula-2 | |
14534 | * M2 Checks:: Modula-2 type and range checks | |
14535 | * M2 Scope:: The scope operators @code{::} and @code{.} | |
14536 | * GDB/M2:: @value{GDBN} and Modula-2 | |
14537 | @end menu | |
14538 | ||
6d2ebf8b | 14539 | @node M2 Operators |
c906108c SS |
14540 | @subsubsection Operators |
14541 | @cindex Modula-2 operators | |
14542 | ||
14543 | Operators must be defined on values of specific types. For instance, | |
14544 | @code{+} is defined on numbers, but not on structures. Operators are | |
14545 | often defined on groups of types. For the purposes of Modula-2, the | |
14546 | following definitions hold: | |
14547 | ||
14548 | @itemize @bullet | |
14549 | ||
14550 | @item | |
14551 | @emph{Integral types} consist of @code{INTEGER}, @code{CARDINAL}, and | |
14552 | their subranges. | |
14553 | ||
14554 | @item | |
14555 | @emph{Character types} consist of @code{CHAR} and its subranges. | |
14556 | ||
14557 | @item | |
14558 | @emph{Floating-point types} consist of @code{REAL}. | |
14559 | ||
14560 | @item | |
14561 | @emph{Pointer types} consist of anything declared as @code{POINTER TO | |
14562 | @var{type}}. | |
14563 | ||
14564 | @item | |
14565 | @emph{Scalar types} consist of all of the above. | |
14566 | ||
14567 | @item | |
14568 | @emph{Set types} consist of @code{SET} and @code{BITSET} types. | |
14569 | ||
14570 | @item | |
14571 | @emph{Boolean types} consist of @code{BOOLEAN}. | |
14572 | @end itemize | |
14573 | ||
14574 | @noindent | |
14575 | The following operators are supported, and appear in order of | |
14576 | increasing precedence: | |
14577 | ||
14578 | @table @code | |
14579 | @item , | |
14580 | Function argument or array index separator. | |
14581 | ||
14582 | @item := | |
14583 | Assignment. The value of @var{var} @code{:=} @var{value} is | |
14584 | @var{value}. | |
14585 | ||
14586 | @item <@r{, }> | |
14587 | Less than, greater than on integral, floating-point, or enumerated | |
14588 | types. | |
14589 | ||
14590 | @item <=@r{, }>= | |
96a2c332 | 14591 | Less than or equal to, greater than or equal to |
c906108c SS |
14592 | on integral, floating-point and enumerated types, or set inclusion on |
14593 | set types. Same precedence as @code{<}. | |
14594 | ||
14595 | @item =@r{, }<>@r{, }# | |
14596 | Equality and two ways of expressing inequality, valid on scalar types. | |
14597 | Same precedence as @code{<}. In @value{GDBN} scripts, only @code{<>} is | |
14598 | available for inequality, since @code{#} conflicts with the script | |
14599 | comment character. | |
14600 | ||
14601 | @item IN | |
14602 | Set membership. Defined on set types and the types of their members. | |
14603 | Same precedence as @code{<}. | |
14604 | ||
14605 | @item OR | |
14606 | Boolean disjunction. Defined on boolean types. | |
14607 | ||
14608 | @item AND@r{, }& | |
d4f3574e | 14609 | Boolean conjunction. Defined on boolean types. |
c906108c SS |
14610 | |
14611 | @item @@ | |
14612 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
14613 | ||
14614 | @item +@r{, }- | |
14615 | Addition and subtraction on integral and floating-point types, or union | |
14616 | and difference on set types. | |
14617 | ||
14618 | @item * | |
14619 | Multiplication on integral and floating-point types, or set intersection | |
14620 | on set types. | |
14621 | ||
14622 | @item / | |
14623 | Division on floating-point types, or symmetric set difference on set | |
14624 | types. Same precedence as @code{*}. | |
14625 | ||
14626 | @item DIV@r{, }MOD | |
14627 | Integer division and remainder. Defined on integral types. Same | |
14628 | precedence as @code{*}. | |
14629 | ||
14630 | @item - | |
99e008fe | 14631 | Negative. Defined on @code{INTEGER} and @code{REAL} data. |
c906108c SS |
14632 | |
14633 | @item ^ | |
14634 | Pointer dereferencing. Defined on pointer types. | |
14635 | ||
14636 | @item NOT | |
14637 | Boolean negation. Defined on boolean types. Same precedence as | |
14638 | @code{^}. | |
14639 | ||
14640 | @item . | |
14641 | @code{RECORD} field selector. Defined on @code{RECORD} data. Same | |
14642 | precedence as @code{^}. | |
14643 | ||
14644 | @item [] | |
14645 | Array indexing. Defined on @code{ARRAY} data. Same precedence as @code{^}. | |
14646 | ||
14647 | @item () | |
14648 | Procedure argument list. Defined on @code{PROCEDURE} objects. Same precedence | |
14649 | as @code{^}. | |
14650 | ||
14651 | @item ::@r{, }. | |
14652 | @value{GDBN} and Modula-2 scope operators. | |
14653 | @end table | |
14654 | ||
14655 | @quotation | |
72019c9c | 14656 | @emph{Warning:} Set expressions and their operations are not yet supported, so @value{GDBN} |
c906108c SS |
14657 | treats the use of the operator @code{IN}, or the use of operators |
14658 | @code{+}, @code{-}, @code{*}, @code{/}, @code{=}, , @code{<>}, @code{#}, | |
14659 | @code{<=}, and @code{>=} on sets as an error. | |
14660 | @end quotation | |
14661 | ||
cb51c4e0 | 14662 | |
6d2ebf8b | 14663 | @node Built-In Func/Proc |
79a6e687 | 14664 | @subsubsection Built-in Functions and Procedures |
cb51c4e0 | 14665 | @cindex Modula-2 built-ins |
c906108c SS |
14666 | |
14667 | Modula-2 also makes available several built-in procedures and functions. | |
14668 | In describing these, the following metavariables are used: | |
14669 | ||
14670 | @table @var | |
14671 | ||
14672 | @item a | |
14673 | represents an @code{ARRAY} variable. | |
14674 | ||
14675 | @item c | |
14676 | represents a @code{CHAR} constant or variable. | |
14677 | ||
14678 | @item i | |
14679 | represents a variable or constant of integral type. | |
14680 | ||
14681 | @item m | |
14682 | represents an identifier that belongs to a set. Generally used in the | |
14683 | same function with the metavariable @var{s}. The type of @var{s} should | |
14684 | be @code{SET OF @var{mtype}} (where @var{mtype} is the type of @var{m}). | |
14685 | ||
14686 | @item n | |
14687 | represents a variable or constant of integral or floating-point type. | |
14688 | ||
14689 | @item r | |
14690 | represents a variable or constant of floating-point type. | |
14691 | ||
14692 | @item t | |
14693 | represents a type. | |
14694 | ||
14695 | @item v | |
14696 | represents a variable. | |
14697 | ||
14698 | @item x | |
14699 | represents a variable or constant of one of many types. See the | |
14700 | explanation of the function for details. | |
14701 | @end table | |
14702 | ||
14703 | All Modula-2 built-in procedures also return a result, described below. | |
14704 | ||
14705 | @table @code | |
14706 | @item ABS(@var{n}) | |
14707 | Returns the absolute value of @var{n}. | |
14708 | ||
14709 | @item CAP(@var{c}) | |
14710 | If @var{c} is a lower case letter, it returns its upper case | |
c3f6f71d | 14711 | equivalent, otherwise it returns its argument. |
c906108c SS |
14712 | |
14713 | @item CHR(@var{i}) | |
14714 | Returns the character whose ordinal value is @var{i}. | |
14715 | ||
14716 | @item DEC(@var{v}) | |
c3f6f71d | 14717 | Decrements the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
14718 | |
14719 | @item DEC(@var{v},@var{i}) | |
14720 | Decrements the value in the variable @var{v} by @var{i}. Returns the | |
14721 | new value. | |
14722 | ||
14723 | @item EXCL(@var{m},@var{s}) | |
14724 | Removes the element @var{m} from the set @var{s}. Returns the new | |
14725 | set. | |
14726 | ||
14727 | @item FLOAT(@var{i}) | |
14728 | Returns the floating point equivalent of the integer @var{i}. | |
14729 | ||
14730 | @item HIGH(@var{a}) | |
14731 | Returns the index of the last member of @var{a}. | |
14732 | ||
14733 | @item INC(@var{v}) | |
c3f6f71d | 14734 | Increments the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
14735 | |
14736 | @item INC(@var{v},@var{i}) | |
14737 | Increments the value in the variable @var{v} by @var{i}. Returns the | |
14738 | new value. | |
14739 | ||
14740 | @item INCL(@var{m},@var{s}) | |
14741 | Adds the element @var{m} to the set @var{s} if it is not already | |
14742 | there. Returns the new set. | |
14743 | ||
14744 | @item MAX(@var{t}) | |
14745 | Returns the maximum value of the type @var{t}. | |
14746 | ||
14747 | @item MIN(@var{t}) | |
14748 | Returns the minimum value of the type @var{t}. | |
14749 | ||
14750 | @item ODD(@var{i}) | |
14751 | Returns boolean TRUE if @var{i} is an odd number. | |
14752 | ||
14753 | @item ORD(@var{x}) | |
14754 | Returns the ordinal value of its argument. For example, the ordinal | |
697aa1b7 EZ |
14755 | value of a character is its @sc{ascii} value (on machines supporting |
14756 | the @sc{ascii} character set). The argument @var{x} must be of an | |
14757 | ordered type, which include integral, character and enumerated types. | |
c906108c SS |
14758 | |
14759 | @item SIZE(@var{x}) | |
697aa1b7 EZ |
14760 | Returns the size of its argument. The argument @var{x} can be a |
14761 | variable or a type. | |
c906108c SS |
14762 | |
14763 | @item TRUNC(@var{r}) | |
14764 | Returns the integral part of @var{r}. | |
14765 | ||
844781a1 | 14766 | @item TSIZE(@var{x}) |
697aa1b7 EZ |
14767 | Returns the size of its argument. The argument @var{x} can be a |
14768 | variable or a type. | |
844781a1 | 14769 | |
c906108c SS |
14770 | @item VAL(@var{t},@var{i}) |
14771 | Returns the member of the type @var{t} whose ordinal value is @var{i}. | |
14772 | @end table | |
14773 | ||
14774 | @quotation | |
14775 | @emph{Warning:} Sets and their operations are not yet supported, so | |
14776 | @value{GDBN} treats the use of procedures @code{INCL} and @code{EXCL} as | |
14777 | an error. | |
14778 | @end quotation | |
14779 | ||
14780 | @cindex Modula-2 constants | |
6d2ebf8b | 14781 | @node M2 Constants |
c906108c SS |
14782 | @subsubsection Constants |
14783 | ||
14784 | @value{GDBN} allows you to express the constants of Modula-2 in the following | |
14785 | ways: | |
14786 | ||
14787 | @itemize @bullet | |
14788 | ||
14789 | @item | |
14790 | Integer constants are simply a sequence of digits. When used in an | |
14791 | expression, a constant is interpreted to be type-compatible with the | |
14792 | rest of the expression. Hexadecimal integers are specified by a | |
14793 | trailing @samp{H}, and octal integers by a trailing @samp{B}. | |
14794 | ||
14795 | @item | |
14796 | Floating point constants appear as a sequence of digits, followed by a | |
14797 | decimal point and another sequence of digits. An optional exponent can | |
14798 | then be specified, in the form @samp{E@r{[}+@r{|}-@r{]}@var{nnn}}, where | |
14799 | @samp{@r{[}+@r{|}-@r{]}@var{nnn}} is the desired exponent. All of the | |
14800 | digits of the floating point constant must be valid decimal (base 10) | |
14801 | digits. | |
14802 | ||
14803 | @item | |
14804 | Character constants consist of a single character enclosed by a pair of | |
14805 | like quotes, either single (@code{'}) or double (@code{"}). They may | |
c3f6f71d | 14806 | also be expressed by their ordinal value (their @sc{ascii} value, usually) |
c906108c SS |
14807 | followed by a @samp{C}. |
14808 | ||
14809 | @item | |
14810 | String constants consist of a sequence of characters enclosed by a | |
14811 | pair of like quotes, either single (@code{'}) or double (@code{"}). | |
14812 | Escape sequences in the style of C are also allowed. @xref{C | |
79a6e687 | 14813 | Constants, ,C and C@t{++} Constants}, for a brief explanation of escape |
c906108c SS |
14814 | sequences. |
14815 | ||
14816 | @item | |
14817 | Enumerated constants consist of an enumerated identifier. | |
14818 | ||
14819 | @item | |
14820 | Boolean constants consist of the identifiers @code{TRUE} and | |
14821 | @code{FALSE}. | |
14822 | ||
14823 | @item | |
14824 | Pointer constants consist of integral values only. | |
14825 | ||
14826 | @item | |
14827 | Set constants are not yet supported. | |
14828 | @end itemize | |
14829 | ||
72019c9c GM |
14830 | @node M2 Types |
14831 | @subsubsection Modula-2 Types | |
14832 | @cindex Modula-2 types | |
14833 | ||
14834 | Currently @value{GDBN} can print the following data types in Modula-2 | |
14835 | syntax: array types, record types, set types, pointer types, procedure | |
14836 | types, enumerated types, subrange types and base types. You can also | |
14837 | print the contents of variables declared using these type. | |
14838 | This section gives a number of simple source code examples together with | |
14839 | sample @value{GDBN} sessions. | |
14840 | ||
14841 | The first example contains the following section of code: | |
14842 | ||
14843 | @smallexample | |
14844 | VAR | |
14845 | s: SET OF CHAR ; | |
14846 | r: [20..40] ; | |
14847 | @end smallexample | |
14848 | ||
14849 | @noindent | |
14850 | and you can request @value{GDBN} to interrogate the type and value of | |
14851 | @code{r} and @code{s}. | |
14852 | ||
14853 | @smallexample | |
14854 | (@value{GDBP}) print s | |
14855 | @{'A'..'C', 'Z'@} | |
14856 | (@value{GDBP}) ptype s | |
14857 | SET OF CHAR | |
14858 | (@value{GDBP}) print r | |
14859 | 21 | |
14860 | (@value{GDBP}) ptype r | |
14861 | [20..40] | |
14862 | @end smallexample | |
14863 | ||
14864 | @noindent | |
14865 | Likewise if your source code declares @code{s} as: | |
14866 | ||
14867 | @smallexample | |
14868 | VAR | |
14869 | s: SET ['A'..'Z'] ; | |
14870 | @end smallexample | |
14871 | ||
14872 | @noindent | |
14873 | then you may query the type of @code{s} by: | |
14874 | ||
14875 | @smallexample | |
14876 | (@value{GDBP}) ptype s | |
14877 | type = SET ['A'..'Z'] | |
14878 | @end smallexample | |
14879 | ||
14880 | @noindent | |
14881 | Note that at present you cannot interactively manipulate set | |
14882 | expressions using the debugger. | |
14883 | ||
14884 | The following example shows how you might declare an array in Modula-2 | |
14885 | and how you can interact with @value{GDBN} to print its type and contents: | |
14886 | ||
14887 | @smallexample | |
14888 | VAR | |
14889 | s: ARRAY [-10..10] OF CHAR ; | |
14890 | @end smallexample | |
14891 | ||
14892 | @smallexample | |
14893 | (@value{GDBP}) ptype s | |
14894 | ARRAY [-10..10] OF CHAR | |
14895 | @end smallexample | |
14896 | ||
14897 | Note that the array handling is not yet complete and although the type | |
14898 | is printed correctly, expression handling still assumes that all | |
14899 | arrays have a lower bound of zero and not @code{-10} as in the example | |
844781a1 | 14900 | above. |
72019c9c GM |
14901 | |
14902 | Here are some more type related Modula-2 examples: | |
14903 | ||
14904 | @smallexample | |
14905 | TYPE | |
14906 | colour = (blue, red, yellow, green) ; | |
14907 | t = [blue..yellow] ; | |
14908 | VAR | |
14909 | s: t ; | |
14910 | BEGIN | |
14911 | s := blue ; | |
14912 | @end smallexample | |
14913 | ||
14914 | @noindent | |
14915 | The @value{GDBN} interaction shows how you can query the data type | |
14916 | and value of a variable. | |
14917 | ||
14918 | @smallexample | |
14919 | (@value{GDBP}) print s | |
14920 | $1 = blue | |
14921 | (@value{GDBP}) ptype t | |
14922 | type = [blue..yellow] | |
14923 | @end smallexample | |
14924 | ||
14925 | @noindent | |
14926 | In this example a Modula-2 array is declared and its contents | |
14927 | displayed. Observe that the contents are written in the same way as | |
14928 | their @code{C} counterparts. | |
14929 | ||
14930 | @smallexample | |
14931 | VAR | |
14932 | s: ARRAY [1..5] OF CARDINAL ; | |
14933 | BEGIN | |
14934 | s[1] := 1 ; | |
14935 | @end smallexample | |
14936 | ||
14937 | @smallexample | |
14938 | (@value{GDBP}) print s | |
14939 | $1 = @{1, 0, 0, 0, 0@} | |
14940 | (@value{GDBP}) ptype s | |
14941 | type = ARRAY [1..5] OF CARDINAL | |
14942 | @end smallexample | |
14943 | ||
14944 | The Modula-2 language interface to @value{GDBN} also understands | |
14945 | pointer types as shown in this example: | |
14946 | ||
14947 | @smallexample | |
14948 | VAR | |
14949 | s: POINTER TO ARRAY [1..5] OF CARDINAL ; | |
14950 | BEGIN | |
14951 | NEW(s) ; | |
14952 | s^[1] := 1 ; | |
14953 | @end smallexample | |
14954 | ||
14955 | @noindent | |
14956 | and you can request that @value{GDBN} describes the type of @code{s}. | |
14957 | ||
14958 | @smallexample | |
14959 | (@value{GDBP}) ptype s | |
14960 | type = POINTER TO ARRAY [1..5] OF CARDINAL | |
14961 | @end smallexample | |
14962 | ||
14963 | @value{GDBN} handles compound types as we can see in this example. | |
14964 | Here we combine array types, record types, pointer types and subrange | |
14965 | types: | |
14966 | ||
14967 | @smallexample | |
14968 | TYPE | |
14969 | foo = RECORD | |
14970 | f1: CARDINAL ; | |
14971 | f2: CHAR ; | |
14972 | f3: myarray ; | |
14973 | END ; | |
14974 | ||
14975 | myarray = ARRAY myrange OF CARDINAL ; | |
14976 | myrange = [-2..2] ; | |
14977 | VAR | |
14978 | s: POINTER TO ARRAY myrange OF foo ; | |
14979 | @end smallexample | |
14980 | ||
14981 | @noindent | |
14982 | and you can ask @value{GDBN} to describe the type of @code{s} as shown | |
14983 | below. | |
14984 | ||
14985 | @smallexample | |
14986 | (@value{GDBP}) ptype s | |
14987 | type = POINTER TO ARRAY [-2..2] OF foo = RECORD | |
14988 | f1 : CARDINAL; | |
14989 | f2 : CHAR; | |
14990 | f3 : ARRAY [-2..2] OF CARDINAL; | |
14991 | END | |
14992 | @end smallexample | |
14993 | ||
6d2ebf8b | 14994 | @node M2 Defaults |
79a6e687 | 14995 | @subsubsection Modula-2 Defaults |
c906108c SS |
14996 | @cindex Modula-2 defaults |
14997 | ||
14998 | If type and range checking are set automatically by @value{GDBN}, they | |
14999 | both default to @code{on} whenever the working language changes to | |
d4f3574e | 15000 | Modula-2. This happens regardless of whether you or @value{GDBN} |
c906108c SS |
15001 | selected the working language. |
15002 | ||
15003 | If you allow @value{GDBN} to set the language automatically, then entering | |
15004 | code compiled from a file whose name ends with @file{.mod} sets the | |
79a6e687 BW |
15005 | working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} |
15006 | Infer the Source Language}, for further details. | |
c906108c | 15007 | |
6d2ebf8b | 15008 | @node Deviations |
79a6e687 | 15009 | @subsubsection Deviations from Standard Modula-2 |
c906108c SS |
15010 | @cindex Modula-2, deviations from |
15011 | ||
15012 | A few changes have been made to make Modula-2 programs easier to debug. | |
15013 | This is done primarily via loosening its type strictness: | |
15014 | ||
15015 | @itemize @bullet | |
15016 | @item | |
15017 | Unlike in standard Modula-2, pointer constants can be formed by | |
15018 | integers. This allows you to modify pointer variables during | |
15019 | debugging. (In standard Modula-2, the actual address contained in a | |
15020 | pointer variable is hidden from you; it can only be modified | |
15021 | through direct assignment to another pointer variable or expression that | |
15022 | returned a pointer.) | |
15023 | ||
15024 | @item | |
15025 | C escape sequences can be used in strings and characters to represent | |
15026 | non-printable characters. @value{GDBN} prints out strings with these | |
15027 | escape sequences embedded. Single non-printable characters are | |
15028 | printed using the @samp{CHR(@var{nnn})} format. | |
15029 | ||
15030 | @item | |
15031 | The assignment operator (@code{:=}) returns the value of its right-hand | |
15032 | argument. | |
15033 | ||
15034 | @item | |
15035 | All built-in procedures both modify @emph{and} return their argument. | |
15036 | @end itemize | |
15037 | ||
6d2ebf8b | 15038 | @node M2 Checks |
79a6e687 | 15039 | @subsubsection Modula-2 Type and Range Checks |
c906108c SS |
15040 | @cindex Modula-2 checks |
15041 | ||
15042 | @quotation | |
15043 | @emph{Warning:} in this release, @value{GDBN} does not yet perform type or | |
15044 | range checking. | |
15045 | @end quotation | |
15046 | @c FIXME remove warning when type/range checks added | |
15047 | ||
15048 | @value{GDBN} considers two Modula-2 variables type equivalent if: | |
15049 | ||
15050 | @itemize @bullet | |
15051 | @item | |
15052 | They are of types that have been declared equivalent via a @code{TYPE | |
15053 | @var{t1} = @var{t2}} statement | |
15054 | ||
15055 | @item | |
15056 | They have been declared on the same line. (Note: This is true of the | |
15057 | @sc{gnu} Modula-2 compiler, but it may not be true of other compilers.) | |
15058 | @end itemize | |
15059 | ||
15060 | As long as type checking is enabled, any attempt to combine variables | |
15061 | whose types are not equivalent is an error. | |
15062 | ||
15063 | Range checking is done on all mathematical operations, assignment, array | |
15064 | index bounds, and all built-in functions and procedures. | |
15065 | ||
6d2ebf8b | 15066 | @node M2 Scope |
79a6e687 | 15067 | @subsubsection The Scope Operators @code{::} and @code{.} |
c906108c | 15068 | @cindex scope |
41afff9a | 15069 | @cindex @code{.}, Modula-2 scope operator |
c906108c SS |
15070 | @cindex colon, doubled as scope operator |
15071 | @ifinfo | |
41afff9a | 15072 | @vindex colon-colon@r{, in Modula-2} |
c906108c SS |
15073 | @c Info cannot handle :: but TeX can. |
15074 | @end ifinfo | |
a67ec3f4 | 15075 | @ifnotinfo |
41afff9a | 15076 | @vindex ::@r{, in Modula-2} |
a67ec3f4 | 15077 | @end ifnotinfo |
c906108c SS |
15078 | |
15079 | There are a few subtle differences between the Modula-2 scope operator | |
15080 | (@code{.}) and the @value{GDBN} scope operator (@code{::}). The two have | |
15081 | similar syntax: | |
15082 | ||
474c8240 | 15083 | @smallexample |
c906108c SS |
15084 | |
15085 | @var{module} . @var{id} | |
15086 | @var{scope} :: @var{id} | |
474c8240 | 15087 | @end smallexample |
c906108c SS |
15088 | |
15089 | @noindent | |
15090 | where @var{scope} is the name of a module or a procedure, | |
15091 | @var{module} the name of a module, and @var{id} is any declared | |
15092 | identifier within your program, except another module. | |
15093 | ||
15094 | Using the @code{::} operator makes @value{GDBN} search the scope | |
15095 | specified by @var{scope} for the identifier @var{id}. If it is not | |
15096 | found in the specified scope, then @value{GDBN} searches all scopes | |
15097 | enclosing the one specified by @var{scope}. | |
15098 | ||
15099 | Using the @code{.} operator makes @value{GDBN} search the current scope for | |
15100 | the identifier specified by @var{id} that was imported from the | |
15101 | definition module specified by @var{module}. With this operator, it is | |
15102 | an error if the identifier @var{id} was not imported from definition | |
15103 | module @var{module}, or if @var{id} is not an identifier in | |
15104 | @var{module}. | |
15105 | ||
6d2ebf8b | 15106 | @node GDB/M2 |
c906108c SS |
15107 | @subsubsection @value{GDBN} and Modula-2 |
15108 | ||
15109 | Some @value{GDBN} commands have little use when debugging Modula-2 programs. | |
15110 | Five subcommands of @code{set print} and @code{show print} apply | |
b37052ae | 15111 | specifically to C and C@t{++}: @samp{vtbl}, @samp{demangle}, |
c906108c | 15112 | @samp{asm-demangle}, @samp{object}, and @samp{union}. The first four |
b37052ae | 15113 | apply to C@t{++}, and the last to the C @code{union} type, which has no direct |
c906108c SS |
15114 | analogue in Modula-2. |
15115 | ||
15116 | The @code{@@} operator (@pxref{Expressions, ,Expressions}), while available | |
d4f3574e | 15117 | with any language, is not useful with Modula-2. Its |
c906108c | 15118 | intent is to aid the debugging of @dfn{dynamic arrays}, which cannot be |
b37052ae | 15119 | created in Modula-2 as they can in C or C@t{++}. However, because an |
c906108c | 15120 | address can be specified by an integral constant, the construct |
d4f3574e | 15121 | @samp{@{@var{type}@}@var{adrexp}} is still useful. |
c906108c SS |
15122 | |
15123 | @cindex @code{#} in Modula-2 | |
15124 | In @value{GDBN} scripts, the Modula-2 inequality operator @code{#} is | |
15125 | interpreted as the beginning of a comment. Use @code{<>} instead. | |
c906108c | 15126 | |
e07c999f PH |
15127 | @node Ada |
15128 | @subsection Ada | |
15129 | @cindex Ada | |
15130 | ||
15131 | The extensions made to @value{GDBN} for Ada only support | |
15132 | output from the @sc{gnu} Ada (GNAT) compiler. | |
15133 | Other Ada compilers are not currently supported, and | |
15134 | attempting to debug executables produced by them is most likely | |
15135 | to be difficult. | |
15136 | ||
15137 | ||
15138 | @cindex expressions in Ada | |
15139 | @menu | |
15140 | * Ada Mode Intro:: General remarks on the Ada syntax | |
15141 | and semantics supported by Ada mode | |
15142 | in @value{GDBN}. | |
15143 | * Omissions from Ada:: Restrictions on the Ada expression syntax. | |
15144 | * Additions to Ada:: Extensions of the Ada expression syntax. | |
15145 | * Stopping Before Main Program:: Debugging the program during elaboration. | |
58d06528 | 15146 | * Ada Exceptions:: Ada Exceptions |
20924a55 JB |
15147 | * Ada Tasks:: Listing and setting breakpoints in tasks. |
15148 | * Ada Tasks and Core Files:: Tasking Support when Debugging Core Files | |
6e1bb179 JB |
15149 | * Ravenscar Profile:: Tasking Support when using the Ravenscar |
15150 | Profile | |
e07c999f PH |
15151 | * Ada Glitches:: Known peculiarities of Ada mode. |
15152 | @end menu | |
15153 | ||
15154 | @node Ada Mode Intro | |
15155 | @subsubsection Introduction | |
15156 | @cindex Ada mode, general | |
15157 | ||
15158 | The Ada mode of @value{GDBN} supports a fairly large subset of Ada expression | |
15159 | syntax, with some extensions. | |
15160 | The philosophy behind the design of this subset is | |
15161 | ||
15162 | @itemize @bullet | |
15163 | @item | |
15164 | That @value{GDBN} should provide basic literals and access to operations for | |
15165 | arithmetic, dereferencing, field selection, indexing, and subprogram calls, | |
15166 | leaving more sophisticated computations to subprograms written into the | |
15167 | program (which therefore may be called from @value{GDBN}). | |
15168 | ||
15169 | @item | |
15170 | That type safety and strict adherence to Ada language restrictions | |
15171 | are not particularly important to the @value{GDBN} user. | |
15172 | ||
15173 | @item | |
15174 | That brevity is important to the @value{GDBN} user. | |
15175 | @end itemize | |
15176 | ||
f3a2dd1a JB |
15177 | Thus, for brevity, the debugger acts as if all names declared in |
15178 | user-written packages are directly visible, even if they are not visible | |
15179 | according to Ada rules, thus making it unnecessary to fully qualify most | |
15180 | names with their packages, regardless of context. Where this causes | |
15181 | ambiguity, @value{GDBN} asks the user's intent. | |
e07c999f PH |
15182 | |
15183 | The debugger will start in Ada mode if it detects an Ada main program. | |
15184 | As for other languages, it will enter Ada mode when stopped in a program that | |
15185 | was translated from an Ada source file. | |
15186 | ||
15187 | While in Ada mode, you may use `@t{--}' for comments. This is useful | |
15188 | mostly for documenting command files. The standard @value{GDBN} comment | |
15189 | (@samp{#}) still works at the beginning of a line in Ada mode, but not in the | |
15190 | middle (to allow based literals). | |
15191 | ||
15192 | The debugger supports limited overloading. Given a subprogram call in which | |
15193 | the function symbol has multiple definitions, it will use the number of | |
15194 | actual parameters and some information about their types to attempt to narrow | |
15195 | the set of definitions. It also makes very limited use of context, preferring | |
15196 | procedures to functions in the context of the @code{call} command, and | |
15197 | functions to procedures elsewhere. | |
15198 | ||
15199 | @node Omissions from Ada | |
15200 | @subsubsection Omissions from Ada | |
15201 | @cindex Ada, omissions from | |
15202 | ||
15203 | Here are the notable omissions from the subset: | |
15204 | ||
15205 | @itemize @bullet | |
15206 | @item | |
15207 | Only a subset of the attributes are supported: | |
15208 | ||
15209 | @itemize @minus | |
15210 | @item | |
15211 | @t{'First}, @t{'Last}, and @t{'Length} | |
15212 | on array objects (not on types and subtypes). | |
15213 | ||
15214 | @item | |
15215 | @t{'Min} and @t{'Max}. | |
15216 | ||
15217 | @item | |
15218 | @t{'Pos} and @t{'Val}. | |
15219 | ||
15220 | @item | |
15221 | @t{'Tag}. | |
15222 | ||
15223 | @item | |
15224 | @t{'Range} on array objects (not subtypes), but only as the right | |
15225 | operand of the membership (@code{in}) operator. | |
15226 | ||
15227 | @item | |
15228 | @t{'Access}, @t{'Unchecked_Access}, and | |
15229 | @t{'Unrestricted_Access} (a GNAT extension). | |
15230 | ||
15231 | @item | |
15232 | @t{'Address}. | |
15233 | @end itemize | |
15234 | ||
15235 | @item | |
15236 | The names in | |
15237 | @code{Characters.Latin_1} are not available and | |
15238 | concatenation is not implemented. Thus, escape characters in strings are | |
15239 | not currently available. | |
15240 | ||
15241 | @item | |
15242 | Equality tests (@samp{=} and @samp{/=}) on arrays test for bitwise | |
15243 | equality of representations. They will generally work correctly | |
15244 | for strings and arrays whose elements have integer or enumeration types. | |
15245 | They may not work correctly for arrays whose element | |
15246 | types have user-defined equality, for arrays of real values | |
15247 | (in particular, IEEE-conformant floating point, because of negative | |
15248 | zeroes and NaNs), and for arrays whose elements contain unused bits with | |
15249 | indeterminate values. | |
15250 | ||
15251 | @item | |
15252 | The other component-by-component array operations (@code{and}, @code{or}, | |
15253 | @code{xor}, @code{not}, and relational tests other than equality) | |
15254 | are not implemented. | |
15255 | ||
15256 | @item | |
860701dc PH |
15257 | @cindex array aggregates (Ada) |
15258 | @cindex record aggregates (Ada) | |
15259 | @cindex aggregates (Ada) | |
15260 | There is limited support for array and record aggregates. They are | |
15261 | permitted only on the right sides of assignments, as in these examples: | |
15262 | ||
15263 | @smallexample | |
077e0a52 JB |
15264 | (@value{GDBP}) set An_Array := (1, 2, 3, 4, 5, 6) |
15265 | (@value{GDBP}) set An_Array := (1, others => 0) | |
15266 | (@value{GDBP}) set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6) | |
15267 | (@value{GDBP}) set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9)) | |
15268 | (@value{GDBP}) set A_Record := (1, "Peter", True); | |
15269 | (@value{GDBP}) set A_Record := (Name => "Peter", Id => 1, Alive => True) | |
860701dc PH |
15270 | @end smallexample |
15271 | ||
15272 | Changing a | |
15273 | discriminant's value by assigning an aggregate has an | |
15274 | undefined effect if that discriminant is used within the record. | |
15275 | However, you can first modify discriminants by directly assigning to | |
15276 | them (which normally would not be allowed in Ada), and then performing an | |
15277 | aggregate assignment. For example, given a variable @code{A_Rec} | |
15278 | declared to have a type such as: | |
15279 | ||
15280 | @smallexample | |
15281 | type Rec (Len : Small_Integer := 0) is record | |
15282 | Id : Integer; | |
15283 | Vals : IntArray (1 .. Len); | |
15284 | end record; | |
15285 | @end smallexample | |
15286 | ||
15287 | you can assign a value with a different size of @code{Vals} with two | |
15288 | assignments: | |
15289 | ||
15290 | @smallexample | |
077e0a52 JB |
15291 | (@value{GDBP}) set A_Rec.Len := 4 |
15292 | (@value{GDBP}) set A_Rec := (Id => 42, Vals => (1, 2, 3, 4)) | |
860701dc PH |
15293 | @end smallexample |
15294 | ||
15295 | As this example also illustrates, @value{GDBN} is very loose about the usual | |
15296 | rules concerning aggregates. You may leave out some of the | |
15297 | components of an array or record aggregate (such as the @code{Len} | |
15298 | component in the assignment to @code{A_Rec} above); they will retain their | |
15299 | original values upon assignment. You may freely use dynamic values as | |
15300 | indices in component associations. You may even use overlapping or | |
15301 | redundant component associations, although which component values are | |
15302 | assigned in such cases is not defined. | |
e07c999f PH |
15303 | |
15304 | @item | |
15305 | Calls to dispatching subprograms are not implemented. | |
15306 | ||
15307 | @item | |
15308 | The overloading algorithm is much more limited (i.e., less selective) | |
ae21e955 BW |
15309 | than that of real Ada. It makes only limited use of the context in |
15310 | which a subexpression appears to resolve its meaning, and it is much | |
15311 | looser in its rules for allowing type matches. As a result, some | |
15312 | function calls will be ambiguous, and the user will be asked to choose | |
15313 | the proper resolution. | |
e07c999f PH |
15314 | |
15315 | @item | |
15316 | The @code{new} operator is not implemented. | |
15317 | ||
15318 | @item | |
15319 | Entry calls are not implemented. | |
15320 | ||
15321 | @item | |
15322 | Aside from printing, arithmetic operations on the native VAX floating-point | |
15323 | formats are not supported. | |
15324 | ||
15325 | @item | |
15326 | It is not possible to slice a packed array. | |
158c7665 PH |
15327 | |
15328 | @item | |
15329 | The names @code{True} and @code{False}, when not part of a qualified name, | |
15330 | are interpreted as if implicitly prefixed by @code{Standard}, regardless of | |
15331 | context. | |
15332 | Should your program | |
15333 | redefine these names in a package or procedure (at best a dubious practice), | |
15334 | you will have to use fully qualified names to access their new definitions. | |
e07c999f PH |
15335 | @end itemize |
15336 | ||
15337 | @node Additions to Ada | |
15338 | @subsubsection Additions to Ada | |
15339 | @cindex Ada, deviations from | |
15340 | ||
15341 | As it does for other languages, @value{GDBN} makes certain generic | |
15342 | extensions to Ada (@pxref{Expressions}): | |
15343 | ||
15344 | @itemize @bullet | |
15345 | @item | |
ae21e955 BW |
15346 | If the expression @var{E} is a variable residing in memory (typically |
15347 | a local variable or array element) and @var{N} is a positive integer, | |
15348 | then @code{@var{E}@@@var{N}} displays the values of @var{E} and the | |
15349 | @var{N}-1 adjacent variables following it in memory as an array. In | |
15350 | Ada, this operator is generally not necessary, since its prime use is | |
15351 | in displaying parts of an array, and slicing will usually do this in | |
15352 | Ada. However, there are occasional uses when debugging programs in | |
15353 | which certain debugging information has been optimized away. | |
e07c999f PH |
15354 | |
15355 | @item | |
ae21e955 BW |
15356 | @code{@var{B}::@var{var}} means ``the variable named @var{var} that |
15357 | appears in function or file @var{B}.'' When @var{B} is a file name, | |
15358 | you must typically surround it in single quotes. | |
e07c999f PH |
15359 | |
15360 | @item | |
15361 | The expression @code{@{@var{type}@} @var{addr}} means ``the variable of type | |
15362 | @var{type} that appears at address @var{addr}.'' | |
15363 | ||
15364 | @item | |
15365 | A name starting with @samp{$} is a convenience variable | |
15366 | (@pxref{Convenience Vars}) or a machine register (@pxref{Registers}). | |
15367 | @end itemize | |
15368 | ||
ae21e955 BW |
15369 | In addition, @value{GDBN} provides a few other shortcuts and outright |
15370 | additions specific to Ada: | |
e07c999f PH |
15371 | |
15372 | @itemize @bullet | |
15373 | @item | |
15374 | The assignment statement is allowed as an expression, returning | |
15375 | its right-hand operand as its value. Thus, you may enter | |
15376 | ||
15377 | @smallexample | |
077e0a52 JB |
15378 | (@value{GDBP}) set x := y + 3 |
15379 | (@value{GDBP}) print A(tmp := y + 1) | |
e07c999f PH |
15380 | @end smallexample |
15381 | ||
15382 | @item | |
15383 | The semicolon is allowed as an ``operator,'' returning as its value | |
15384 | the value of its right-hand operand. | |
15385 | This allows, for example, | |
15386 | complex conditional breaks: | |
15387 | ||
15388 | @smallexample | |
077e0a52 JB |
15389 | (@value{GDBP}) break f |
15390 | (@value{GDBP}) condition 1 (report(i); k += 1; A(k) > 100) | |
e07c999f PH |
15391 | @end smallexample |
15392 | ||
15393 | @item | |
15394 | Rather than use catenation and symbolic character names to introduce special | |
15395 | characters into strings, one may instead use a special bracket notation, | |
15396 | which is also used to print strings. A sequence of characters of the form | |
15397 | @samp{["@var{XX}"]} within a string or character literal denotes the | |
15398 | (single) character whose numeric encoding is @var{XX} in hexadecimal. The | |
15399 | sequence of characters @samp{["""]} also denotes a single quotation mark | |
15400 | in strings. For example, | |
15401 | @smallexample | |
15402 | "One line.["0a"]Next line.["0a"]" | |
15403 | @end smallexample | |
15404 | @noindent | |
ae21e955 BW |
15405 | contains an ASCII newline character (@code{Ada.Characters.Latin_1.LF}) |
15406 | after each period. | |
e07c999f PH |
15407 | |
15408 | @item | |
15409 | The subtype used as a prefix for the attributes @t{'Pos}, @t{'Min}, and | |
15410 | @t{'Max} is optional (and is ignored in any case). For example, it is valid | |
15411 | to write | |
15412 | ||
15413 | @smallexample | |
077e0a52 | 15414 | (@value{GDBP}) print 'max(x, y) |
e07c999f PH |
15415 | @end smallexample |
15416 | ||
15417 | @item | |
15418 | When printing arrays, @value{GDBN} uses positional notation when the | |
15419 | array has a lower bound of 1, and uses a modified named notation otherwise. | |
ae21e955 BW |
15420 | For example, a one-dimensional array of three integers with a lower bound |
15421 | of 3 might print as | |
e07c999f PH |
15422 | |
15423 | @smallexample | |
15424 | (3 => 10, 17, 1) | |
15425 | @end smallexample | |
15426 | ||
15427 | @noindent | |
15428 | That is, in contrast to valid Ada, only the first component has a @code{=>} | |
15429 | clause. | |
15430 | ||
15431 | @item | |
15432 | You may abbreviate attributes in expressions with any unique, | |
15433 | multi-character subsequence of | |
15434 | their names (an exact match gets preference). | |
15435 | For example, you may use @t{a'len}, @t{a'gth}, or @t{a'lh} | |
15436 | in place of @t{a'length}. | |
15437 | ||
15438 | @item | |
15439 | @cindex quoting Ada internal identifiers | |
15440 | Since Ada is case-insensitive, the debugger normally maps identifiers you type | |
15441 | to lower case. The GNAT compiler uses upper-case characters for | |
15442 | some of its internal identifiers, which are normally of no interest to users. | |
15443 | For the rare occasions when you actually have to look at them, | |
15444 | enclose them in angle brackets to avoid the lower-case mapping. | |
15445 | For example, | |
15446 | @smallexample | |
077e0a52 | 15447 | (@value{GDBP}) print <JMPBUF_SAVE>[0] |
e07c999f PH |
15448 | @end smallexample |
15449 | ||
15450 | @item | |
15451 | Printing an object of class-wide type or dereferencing an | |
15452 | access-to-class-wide value will display all the components of the object's | |
15453 | specific type (as indicated by its run-time tag). Likewise, component | |
15454 | selection on such a value will operate on the specific type of the | |
15455 | object. | |
15456 | ||
15457 | @end itemize | |
15458 | ||
15459 | @node Stopping Before Main Program | |
15460 | @subsubsection Stopping at the Very Beginning | |
15461 | ||
15462 | @cindex breakpointing Ada elaboration code | |
15463 | It is sometimes necessary to debug the program during elaboration, and | |
15464 | before reaching the main procedure. | |
15465 | As defined in the Ada Reference | |
15466 | Manual, the elaboration code is invoked from a procedure called | |
15467 | @code{adainit}. To run your program up to the beginning of | |
15468 | elaboration, simply use the following two commands: | |
15469 | @code{tbreak adainit} and @code{run}. | |
15470 | ||
58d06528 JB |
15471 | @node Ada Exceptions |
15472 | @subsubsection Ada Exceptions | |
15473 | ||
15474 | A command is provided to list all Ada exceptions: | |
15475 | ||
15476 | @table @code | |
15477 | @kindex info exceptions | |
15478 | @item info exceptions | |
15479 | @itemx info exceptions @var{regexp} | |
15480 | The @code{info exceptions} command allows you to list all Ada exceptions | |
15481 | defined within the program being debugged, as well as their addresses. | |
15482 | With a regular expression, @var{regexp}, as argument, only those exceptions | |
15483 | whose names match @var{regexp} are listed. | |
15484 | @end table | |
15485 | ||
15486 | Below is a small example, showing how the command can be used, first | |
15487 | without argument, and next with a regular expression passed as an | |
15488 | argument. | |
15489 | ||
15490 | @smallexample | |
15491 | (@value{GDBP}) info exceptions | |
15492 | All defined Ada exceptions: | |
15493 | constraint_error: 0x613da0 | |
15494 | program_error: 0x613d20 | |
15495 | storage_error: 0x613ce0 | |
15496 | tasking_error: 0x613ca0 | |
15497 | const.aint_global_e: 0x613b00 | |
15498 | (@value{GDBP}) info exceptions const.aint | |
15499 | All Ada exceptions matching regular expression "const.aint": | |
15500 | constraint_error: 0x613da0 | |
15501 | const.aint_global_e: 0x613b00 | |
15502 | @end smallexample | |
15503 | ||
15504 | It is also possible to ask @value{GDBN} to stop your program's execution | |
15505 | when an exception is raised. For more details, see @ref{Set Catchpoints}. | |
15506 | ||
20924a55 JB |
15507 | @node Ada Tasks |
15508 | @subsubsection Extensions for Ada Tasks | |
15509 | @cindex Ada, tasking | |
15510 | ||
15511 | Support for Ada tasks is analogous to that for threads (@pxref{Threads}). | |
15512 | @value{GDBN} provides the following task-related commands: | |
15513 | ||
15514 | @table @code | |
15515 | @kindex info tasks | |
15516 | @item info tasks | |
15517 | This command shows a list of current Ada tasks, as in the following example: | |
15518 | ||
15519 | ||
15520 | @smallexample | |
15521 | @iftex | |
15522 | @leftskip=0.5cm | |
15523 | @end iftex | |
15524 | (@value{GDBP}) info tasks | |
15525 | ID TID P-ID Pri State Name | |
15526 | 1 8088000 0 15 Child Activation Wait main_task | |
15527 | 2 80a4000 1 15 Accept Statement b | |
15528 | 3 809a800 1 15 Child Activation Wait a | |
32cd1edc | 15529 | * 4 80ae800 3 15 Runnable c |
20924a55 JB |
15530 | |
15531 | @end smallexample | |
15532 | ||
15533 | @noindent | |
15534 | In this listing, the asterisk before the last task indicates it to be the | |
15535 | task currently being inspected. | |
15536 | ||
15537 | @table @asis | |
15538 | @item ID | |
15539 | Represents @value{GDBN}'s internal task number. | |
15540 | ||
15541 | @item TID | |
15542 | The Ada task ID. | |
15543 | ||
15544 | @item P-ID | |
15545 | The parent's task ID (@value{GDBN}'s internal task number). | |
15546 | ||
15547 | @item Pri | |
15548 | The base priority of the task. | |
15549 | ||
15550 | @item State | |
15551 | Current state of the task. | |
15552 | ||
15553 | @table @code | |
15554 | @item Unactivated | |
15555 | The task has been created but has not been activated. It cannot be | |
15556 | executing. | |
15557 | ||
20924a55 JB |
15558 | @item Runnable |
15559 | The task is not blocked for any reason known to Ada. (It may be waiting | |
15560 | for a mutex, though.) It is conceptually "executing" in normal mode. | |
15561 | ||
15562 | @item Terminated | |
15563 | The task is terminated, in the sense of ARM 9.3 (5). Any dependents | |
15564 | that were waiting on terminate alternatives have been awakened and have | |
15565 | terminated themselves. | |
15566 | ||
15567 | @item Child Activation Wait | |
15568 | The task is waiting for created tasks to complete activation. | |
15569 | ||
15570 | @item Accept Statement | |
15571 | The task is waiting on an accept or selective wait statement. | |
15572 | ||
15573 | @item Waiting on entry call | |
15574 | The task is waiting on an entry call. | |
15575 | ||
15576 | @item Async Select Wait | |
15577 | The task is waiting to start the abortable part of an asynchronous | |
15578 | select statement. | |
15579 | ||
15580 | @item Delay Sleep | |
15581 | The task is waiting on a select statement with only a delay | |
15582 | alternative open. | |
15583 | ||
15584 | @item Child Termination Wait | |
15585 | The task is sleeping having completed a master within itself, and is | |
15586 | waiting for the tasks dependent on that master to become terminated or | |
15587 | waiting on a terminate Phase. | |
15588 | ||
15589 | @item Wait Child in Term Alt | |
15590 | The task is sleeping waiting for tasks on terminate alternatives to | |
15591 | finish terminating. | |
15592 | ||
15593 | @item Accepting RV with @var{taskno} | |
15594 | The task is accepting a rendez-vous with the task @var{taskno}. | |
15595 | @end table | |
15596 | ||
15597 | @item Name | |
15598 | Name of the task in the program. | |
15599 | ||
15600 | @end table | |
15601 | ||
15602 | @kindex info task @var{taskno} | |
15603 | @item info task @var{taskno} | |
15604 | This command shows detailled informations on the specified task, as in | |
15605 | the following example: | |
15606 | @smallexample | |
15607 | @iftex | |
15608 | @leftskip=0.5cm | |
15609 | @end iftex | |
15610 | (@value{GDBP}) info tasks | |
15611 | ID TID P-ID Pri State Name | |
15612 | 1 8077880 0 15 Child Activation Wait main_task | |
32cd1edc | 15613 | * 2 807c468 1 15 Runnable task_1 |
20924a55 JB |
15614 | (@value{GDBP}) info task 2 |
15615 | Ada Task: 0x807c468 | |
15616 | Name: task_1 | |
15617 | Thread: 0x807f378 | |
15618 | Parent: 1 (main_task) | |
15619 | Base Priority: 15 | |
15620 | State: Runnable | |
15621 | @end smallexample | |
15622 | ||
15623 | @item task | |
15624 | @kindex task@r{ (Ada)} | |
15625 | @cindex current Ada task ID | |
15626 | This command prints the ID of the current task. | |
15627 | ||
15628 | @smallexample | |
15629 | @iftex | |
15630 | @leftskip=0.5cm | |
15631 | @end iftex | |
15632 | (@value{GDBP}) info tasks | |
15633 | ID TID P-ID Pri State Name | |
15634 | 1 8077870 0 15 Child Activation Wait main_task | |
32cd1edc | 15635 | * 2 807c458 1 15 Runnable t |
20924a55 JB |
15636 | (@value{GDBP}) task |
15637 | [Current task is 2] | |
15638 | @end smallexample | |
15639 | ||
15640 | @item task @var{taskno} | |
15641 | @cindex Ada task switching | |
15642 | This command is like the @code{thread @var{threadno}} | |
15643 | command (@pxref{Threads}). It switches the context of debugging | |
15644 | from the current task to the given task. | |
15645 | ||
15646 | @smallexample | |
15647 | @iftex | |
15648 | @leftskip=0.5cm | |
15649 | @end iftex | |
15650 | (@value{GDBP}) info tasks | |
15651 | ID TID P-ID Pri State Name | |
15652 | 1 8077870 0 15 Child Activation Wait main_task | |
32cd1edc | 15653 | * 2 807c458 1 15 Runnable t |
20924a55 JB |
15654 | (@value{GDBP}) task 1 |
15655 | [Switching to task 1] | |
15656 | #0 0x8067726 in pthread_cond_wait () | |
15657 | (@value{GDBP}) bt | |
15658 | #0 0x8067726 in pthread_cond_wait () | |
15659 | #1 0x8056714 in system.os_interface.pthread_cond_wait () | |
15660 | #2 0x805cb63 in system.task_primitives.operations.sleep () | |
15661 | #3 0x806153e in system.tasking.stages.activate_tasks () | |
15662 | #4 0x804aacc in un () at un.adb:5 | |
15663 | @end smallexample | |
15664 | ||
45ac276d JB |
15665 | @item break @var{linespec} task @var{taskno} |
15666 | @itemx break @var{linespec} task @var{taskno} if @dots{} | |
15667 | @cindex breakpoints and tasks, in Ada | |
15668 | @cindex task breakpoints, in Ada | |
15669 | @kindex break @dots{} task @var{taskno}@r{ (Ada)} | |
15670 | These commands are like the @code{break @dots{} thread @dots{}} | |
697aa1b7 EZ |
15671 | command (@pxref{Thread Stops}). The |
15672 | @var{linespec} argument specifies source lines, as described | |
45ac276d JB |
15673 | in @ref{Specify Location}. |
15674 | ||
15675 | Use the qualifier @samp{task @var{taskno}} with a breakpoint command | |
15676 | to specify that you only want @value{GDBN} to stop the program when a | |
697aa1b7 | 15677 | particular Ada task reaches this breakpoint. The @var{taskno} is one of the |
45ac276d JB |
15678 | numeric task identifiers assigned by @value{GDBN}, shown in the first |
15679 | column of the @samp{info tasks} display. | |
15680 | ||
15681 | If you do not specify @samp{task @var{taskno}} when you set a | |
15682 | breakpoint, the breakpoint applies to @emph{all} tasks of your | |
15683 | program. | |
15684 | ||
15685 | You can use the @code{task} qualifier on conditional breakpoints as | |
15686 | well; in this case, place @samp{task @var{taskno}} before the | |
15687 | breakpoint condition (before the @code{if}). | |
15688 | ||
15689 | For example, | |
15690 | ||
15691 | @smallexample | |
15692 | @iftex | |
15693 | @leftskip=0.5cm | |
15694 | @end iftex | |
15695 | (@value{GDBP}) info tasks | |
15696 | ID TID P-ID Pri State Name | |
15697 | 1 140022020 0 15 Child Activation Wait main_task | |
15698 | 2 140045060 1 15 Accept/Select Wait t2 | |
15699 | 3 140044840 1 15 Runnable t1 | |
15700 | * 4 140056040 1 15 Runnable t3 | |
15701 | (@value{GDBP}) b 15 task 2 | |
15702 | Breakpoint 5 at 0x120044cb0: file test_task_debug.adb, line 15. | |
15703 | (@value{GDBP}) cont | |
15704 | Continuing. | |
15705 | task # 1 running | |
15706 | task # 2 running | |
15707 | ||
15708 | Breakpoint 5, test_task_debug () at test_task_debug.adb:15 | |
15709 | 15 flush; | |
15710 | (@value{GDBP}) info tasks | |
15711 | ID TID P-ID Pri State Name | |
15712 | 1 140022020 0 15 Child Activation Wait main_task | |
15713 | * 2 140045060 1 15 Runnable t2 | |
15714 | 3 140044840 1 15 Runnable t1 | |
15715 | 4 140056040 1 15 Delay Sleep t3 | |
15716 | @end smallexample | |
20924a55 JB |
15717 | @end table |
15718 | ||
15719 | @node Ada Tasks and Core Files | |
15720 | @subsubsection Tasking Support when Debugging Core Files | |
15721 | @cindex Ada tasking and core file debugging | |
15722 | ||
15723 | When inspecting a core file, as opposed to debugging a live program, | |
15724 | tasking support may be limited or even unavailable, depending on | |
15725 | the platform being used. | |
15726 | For instance, on x86-linux, the list of tasks is available, but task | |
15727 | switching is not supported. On Tru64, however, task switching will work | |
15728 | as usual. | |
15729 | ||
15730 | On certain platforms, including Tru64, the debugger needs to perform some | |
15731 | memory writes in order to provide Ada tasking support. When inspecting | |
15732 | a core file, this means that the core file must be opened with read-write | |
15733 | privileges, using the command @samp{"set write on"} (@pxref{Patching}). | |
15734 | Under these circumstances, you should make a backup copy of the core | |
15735 | file before inspecting it with @value{GDBN}. | |
15736 | ||
6e1bb179 JB |
15737 | @node Ravenscar Profile |
15738 | @subsubsection Tasking Support when using the Ravenscar Profile | |
15739 | @cindex Ravenscar Profile | |
15740 | ||
15741 | The @dfn{Ravenscar Profile} is a subset of the Ada tasking features, | |
15742 | specifically designed for systems with safety-critical real-time | |
15743 | requirements. | |
15744 | ||
15745 | @table @code | |
15746 | @kindex set ravenscar task-switching on | |
15747 | @cindex task switching with program using Ravenscar Profile | |
15748 | @item set ravenscar task-switching on | |
15749 | Allows task switching when debugging a program that uses the Ravenscar | |
15750 | Profile. This is the default. | |
15751 | ||
15752 | @kindex set ravenscar task-switching off | |
15753 | @item set ravenscar task-switching off | |
15754 | Turn off task switching when debugging a program that uses the Ravenscar | |
15755 | Profile. This is mostly intended to disable the code that adds support | |
15756 | for the Ravenscar Profile, in case a bug in either @value{GDBN} or in | |
15757 | the Ravenscar runtime is preventing @value{GDBN} from working properly. | |
15758 | To be effective, this command should be run before the program is started. | |
15759 | ||
15760 | @kindex show ravenscar task-switching | |
15761 | @item show ravenscar task-switching | |
15762 | Show whether it is possible to switch from task to task in a program | |
15763 | using the Ravenscar Profile. | |
15764 | ||
15765 | @end table | |
15766 | ||
e07c999f PH |
15767 | @node Ada Glitches |
15768 | @subsubsection Known Peculiarities of Ada Mode | |
15769 | @cindex Ada, problems | |
15770 | ||
15771 | Besides the omissions listed previously (@pxref{Omissions from Ada}), | |
15772 | we know of several problems with and limitations of Ada mode in | |
15773 | @value{GDBN}, | |
15774 | some of which will be fixed with planned future releases of the debugger | |
15775 | and the GNU Ada compiler. | |
15776 | ||
15777 | @itemize @bullet | |
e07c999f PH |
15778 | @item |
15779 | Static constants that the compiler chooses not to materialize as objects in | |
15780 | storage are invisible to the debugger. | |
15781 | ||
15782 | @item | |
15783 | Named parameter associations in function argument lists are ignored (the | |
15784 | argument lists are treated as positional). | |
15785 | ||
15786 | @item | |
15787 | Many useful library packages are currently invisible to the debugger. | |
15788 | ||
15789 | @item | |
15790 | Fixed-point arithmetic, conversions, input, and output is carried out using | |
15791 | floating-point arithmetic, and may give results that only approximate those on | |
15792 | the host machine. | |
15793 | ||
e07c999f PH |
15794 | @item |
15795 | The GNAT compiler never generates the prefix @code{Standard} for any of | |
15796 | the standard symbols defined by the Ada language. @value{GDBN} knows about | |
15797 | this: it will strip the prefix from names when you use it, and will never | |
15798 | look for a name you have so qualified among local symbols, nor match against | |
15799 | symbols in other packages or subprograms. If you have | |
15800 | defined entities anywhere in your program other than parameters and | |
15801 | local variables whose simple names match names in @code{Standard}, | |
15802 | GNAT's lack of qualification here can cause confusion. When this happens, | |
15803 | you can usually resolve the confusion | |
15804 | by qualifying the problematic names with package | |
15805 | @code{Standard} explicitly. | |
15806 | @end itemize | |
15807 | ||
95433b34 JB |
15808 | Older versions of the compiler sometimes generate erroneous debugging |
15809 | information, resulting in the debugger incorrectly printing the value | |
15810 | of affected entities. In some cases, the debugger is able to work | |
15811 | around an issue automatically. In other cases, the debugger is able | |
15812 | to work around the issue, but the work-around has to be specifically | |
15813 | enabled. | |
15814 | ||
15815 | @kindex set ada trust-PAD-over-XVS | |
15816 | @kindex show ada trust-PAD-over-XVS | |
15817 | @table @code | |
15818 | ||
15819 | @item set ada trust-PAD-over-XVS on | |
15820 | Configure GDB to strictly follow the GNAT encoding when computing the | |
15821 | value of Ada entities, particularly when @code{PAD} and @code{PAD___XVS} | |
15822 | types are involved (see @code{ada/exp_dbug.ads} in the GCC sources for | |
15823 | a complete description of the encoding used by the GNAT compiler). | |
15824 | This is the default. | |
15825 | ||
15826 | @item set ada trust-PAD-over-XVS off | |
15827 | This is related to the encoding using by the GNAT compiler. If @value{GDBN} | |
15828 | sometimes prints the wrong value for certain entities, changing @code{ada | |
15829 | trust-PAD-over-XVS} to @code{off} activates a work-around which may fix | |
15830 | the issue. It is always safe to set @code{ada trust-PAD-over-XVS} to | |
15831 | @code{off}, but this incurs a slight performance penalty, so it is | |
15832 | recommended to leave this setting to @code{on} unless necessary. | |
15833 | ||
15834 | @end table | |
15835 | ||
c6044dd1 JB |
15836 | @cindex GNAT descriptive types |
15837 | @cindex GNAT encoding | |
15838 | Internally, the debugger also relies on the compiler following a number | |
15839 | of conventions known as the @samp{GNAT Encoding}, all documented in | |
15840 | @file{gcc/ada/exp_dbug.ads} in the GCC sources. This encoding describes | |
15841 | how the debugging information should be generated for certain types. | |
15842 | In particular, this convention makes use of @dfn{descriptive types}, | |
15843 | which are artificial types generated purely to help the debugger. | |
15844 | ||
15845 | These encodings were defined at a time when the debugging information | |
15846 | format used was not powerful enough to describe some of the more complex | |
15847 | types available in Ada. Since DWARF allows us to express nearly all | |
15848 | Ada features, the long-term goal is to slowly replace these descriptive | |
15849 | types by their pure DWARF equivalent. To facilitate that transition, | |
15850 | a new maintenance option is available to force the debugger to ignore | |
15851 | those descriptive types. It allows the user to quickly evaluate how | |
15852 | well @value{GDBN} works without them. | |
15853 | ||
15854 | @table @code | |
15855 | ||
15856 | @kindex maint ada set ignore-descriptive-types | |
15857 | @item maintenance ada set ignore-descriptive-types [on|off] | |
15858 | Control whether the debugger should ignore descriptive types. | |
15859 | The default is not to ignore descriptives types (@code{off}). | |
15860 | ||
15861 | @kindex maint ada show ignore-descriptive-types | |
15862 | @item maintenance ada show ignore-descriptive-types | |
15863 | Show if descriptive types are ignored by @value{GDBN}. | |
15864 | ||
15865 | @end table | |
15866 | ||
79a6e687 BW |
15867 | @node Unsupported Languages |
15868 | @section Unsupported Languages | |
4e562065 JB |
15869 | |
15870 | @cindex unsupported languages | |
15871 | @cindex minimal language | |
15872 | In addition to the other fully-supported programming languages, | |
15873 | @value{GDBN} also provides a pseudo-language, called @code{minimal}. | |
15874 | It does not represent a real programming language, but provides a set | |
15875 | of capabilities close to what the C or assembly languages provide. | |
15876 | This should allow most simple operations to be performed while debugging | |
15877 | an application that uses a language currently not supported by @value{GDBN}. | |
15878 | ||
15879 | If the language is set to @code{auto}, @value{GDBN} will automatically | |
15880 | select this language if the current frame corresponds to an unsupported | |
15881 | language. | |
15882 | ||
6d2ebf8b | 15883 | @node Symbols |
c906108c SS |
15884 | @chapter Examining the Symbol Table |
15885 | ||
d4f3574e | 15886 | The commands described in this chapter allow you to inquire about the |
c906108c SS |
15887 | symbols (names of variables, functions and types) defined in your |
15888 | program. This information is inherent in the text of your program and | |
15889 | does not change as your program executes. @value{GDBN} finds it in your | |
15890 | program's symbol table, in the file indicated when you started @value{GDBN} | |
79a6e687 BW |
15891 | (@pxref{File Options, ,Choosing Files}), or by one of the |
15892 | file-management commands (@pxref{Files, ,Commands to Specify Files}). | |
c906108c SS |
15893 | |
15894 | @cindex symbol names | |
15895 | @cindex names of symbols | |
15896 | @cindex quoting names | |
15897 | Occasionally, you may need to refer to symbols that contain unusual | |
15898 | characters, which @value{GDBN} ordinarily treats as word delimiters. The | |
15899 | most frequent case is in referring to static variables in other | |
79a6e687 | 15900 | source files (@pxref{Variables,,Program Variables}). File names |
c906108c SS |
15901 | are recorded in object files as debugging symbols, but @value{GDBN} would |
15902 | ordinarily parse a typical file name, like @file{foo.c}, as the three words | |
15903 | @samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize | |
15904 | @samp{foo.c} as a single symbol, enclose it in single quotes; for example, | |
15905 | ||
474c8240 | 15906 | @smallexample |
c906108c | 15907 | p 'foo.c'::x |
474c8240 | 15908 | @end smallexample |
c906108c SS |
15909 | |
15910 | @noindent | |
15911 | looks up the value of @code{x} in the scope of the file @file{foo.c}. | |
15912 | ||
15913 | @table @code | |
a8f24a35 EZ |
15914 | @cindex case-insensitive symbol names |
15915 | @cindex case sensitivity in symbol names | |
15916 | @kindex set case-sensitive | |
15917 | @item set case-sensitive on | |
15918 | @itemx set case-sensitive off | |
15919 | @itemx set case-sensitive auto | |
15920 | Normally, when @value{GDBN} looks up symbols, it matches their names | |
15921 | with case sensitivity determined by the current source language. | |
15922 | Occasionally, you may wish to control that. The command @code{set | |
15923 | case-sensitive} lets you do that by specifying @code{on} for | |
15924 | case-sensitive matches or @code{off} for case-insensitive ones. If | |
15925 | you specify @code{auto}, case sensitivity is reset to the default | |
15926 | suitable for the source language. The default is case-sensitive | |
15927 | matches for all languages except for Fortran, for which the default is | |
15928 | case-insensitive matches. | |
15929 | ||
9c16f35a EZ |
15930 | @kindex show case-sensitive |
15931 | @item show case-sensitive | |
a8f24a35 EZ |
15932 | This command shows the current setting of case sensitivity for symbols |
15933 | lookups. | |
15934 | ||
53342f27 TT |
15935 | @kindex set print type methods |
15936 | @item set print type methods | |
15937 | @itemx set print type methods on | |
15938 | @itemx set print type methods off | |
15939 | Normally, when @value{GDBN} prints a class, it displays any methods | |
15940 | declared in that class. You can control this behavior either by | |
15941 | passing the appropriate flag to @code{ptype}, or using @command{set | |
15942 | print type methods}. Specifying @code{on} will cause @value{GDBN} to | |
15943 | display the methods; this is the default. Specifying @code{off} will | |
15944 | cause @value{GDBN} to omit the methods. | |
15945 | ||
15946 | @kindex show print type methods | |
15947 | @item show print type methods | |
15948 | This command shows the current setting of method display when printing | |
15949 | classes. | |
15950 | ||
15951 | @kindex set print type typedefs | |
15952 | @item set print type typedefs | |
15953 | @itemx set print type typedefs on | |
15954 | @itemx set print type typedefs off | |
15955 | ||
15956 | Normally, when @value{GDBN} prints a class, it displays any typedefs | |
15957 | defined in that class. You can control this behavior either by | |
15958 | passing the appropriate flag to @code{ptype}, or using @command{set | |
15959 | print type typedefs}. Specifying @code{on} will cause @value{GDBN} to | |
15960 | display the typedef definitions; this is the default. Specifying | |
15961 | @code{off} will cause @value{GDBN} to omit the typedef definitions. | |
15962 | Note that this controls whether the typedef definition itself is | |
15963 | printed, not whether typedef names are substituted when printing other | |
15964 | types. | |
15965 | ||
15966 | @kindex show print type typedefs | |
15967 | @item show print type typedefs | |
15968 | This command shows the current setting of typedef display when | |
15969 | printing classes. | |
15970 | ||
c906108c | 15971 | @kindex info address |
b37052ae | 15972 | @cindex address of a symbol |
c906108c SS |
15973 | @item info address @var{symbol} |
15974 | Describe where the data for @var{symbol} is stored. For a register | |
15975 | variable, this says which register it is kept in. For a non-register | |
15976 | local variable, this prints the stack-frame offset at which the variable | |
15977 | is always stored. | |
15978 | ||
15979 | Note the contrast with @samp{print &@var{symbol}}, which does not work | |
15980 | at all for a register variable, and for a stack local variable prints | |
15981 | the exact address of the current instantiation of the variable. | |
15982 | ||
3d67e040 | 15983 | @kindex info symbol |
b37052ae | 15984 | @cindex symbol from address |
9c16f35a | 15985 | @cindex closest symbol and offset for an address |
3d67e040 EZ |
15986 | @item info symbol @var{addr} |
15987 | Print the name of a symbol which is stored at the address @var{addr}. | |
15988 | If no symbol is stored exactly at @var{addr}, @value{GDBN} prints the | |
15989 | nearest symbol and an offset from it: | |
15990 | ||
474c8240 | 15991 | @smallexample |
3d67e040 EZ |
15992 | (@value{GDBP}) info symbol 0x54320 |
15993 | _initialize_vx + 396 in section .text | |
474c8240 | 15994 | @end smallexample |
3d67e040 EZ |
15995 | |
15996 | @noindent | |
15997 | This is the opposite of the @code{info address} command. You can use | |
15998 | it to find out the name of a variable or a function given its address. | |
15999 | ||
c14c28ba PP |
16000 | For dynamically linked executables, the name of executable or shared |
16001 | library containing the symbol is also printed: | |
16002 | ||
16003 | @smallexample | |
16004 | (@value{GDBP}) info symbol 0x400225 | |
16005 | _start + 5 in section .text of /tmp/a.out | |
16006 | (@value{GDBP}) info symbol 0x2aaaac2811cf | |
16007 | __read_nocancel + 6 in section .text of /usr/lib64/libc.so.6 | |
16008 | @end smallexample | |
16009 | ||
c906108c | 16010 | @kindex whatis |
53342f27 | 16011 | @item whatis[/@var{flags}] [@var{arg}] |
177bc839 JK |
16012 | Print the data type of @var{arg}, which can be either an expression |
16013 | or a name of a data type. With no argument, print the data type of | |
16014 | @code{$}, the last value in the value history. | |
16015 | ||
16016 | If @var{arg} is an expression (@pxref{Expressions, ,Expressions}), it | |
16017 | is not actually evaluated, and any side-effecting operations (such as | |
16018 | assignments or function calls) inside it do not take place. | |
16019 | ||
16020 | If @var{arg} is a variable or an expression, @code{whatis} prints its | |
16021 | literal type as it is used in the source code. If the type was | |
16022 | defined using a @code{typedef}, @code{whatis} will @emph{not} print | |
16023 | the data type underlying the @code{typedef}. If the type of the | |
16024 | variable or the expression is a compound data type, such as | |
16025 | @code{struct} or @code{class}, @code{whatis} never prints their | |
16026 | fields or methods. It just prints the @code{struct}/@code{class} | |
16027 | name (a.k.a.@: its @dfn{tag}). If you want to see the members of | |
16028 | such a compound data type, use @code{ptype}. | |
16029 | ||
16030 | If @var{arg} is a type name that was defined using @code{typedef}, | |
16031 | @code{whatis} @dfn{unrolls} only one level of that @code{typedef}. | |
16032 | Unrolling means that @code{whatis} will show the underlying type used | |
16033 | in the @code{typedef} declaration of @var{arg}. However, if that | |
16034 | underlying type is also a @code{typedef}, @code{whatis} will not | |
16035 | unroll it. | |
16036 | ||
16037 | For C code, the type names may also have the form @samp{class | |
16038 | @var{class-name}}, @samp{struct @var{struct-tag}}, @samp{union | |
16039 | @var{union-tag}} or @samp{enum @var{enum-tag}}. | |
c906108c | 16040 | |
53342f27 TT |
16041 | @var{flags} can be used to modify how the type is displayed. |
16042 | Available flags are: | |
16043 | ||
16044 | @table @code | |
16045 | @item r | |
16046 | Display in ``raw'' form. Normally, @value{GDBN} substitutes template | |
16047 | parameters and typedefs defined in a class when printing the class' | |
16048 | members. The @code{/r} flag disables this. | |
16049 | ||
16050 | @item m | |
16051 | Do not print methods defined in the class. | |
16052 | ||
16053 | @item M | |
16054 | Print methods defined in the class. This is the default, but the flag | |
16055 | exists in case you change the default with @command{set print type methods}. | |
16056 | ||
16057 | @item t | |
16058 | Do not print typedefs defined in the class. Note that this controls | |
16059 | whether the typedef definition itself is printed, not whether typedef | |
16060 | names are substituted when printing other types. | |
16061 | ||
16062 | @item T | |
16063 | Print typedefs defined in the class. This is the default, but the flag | |
16064 | exists in case you change the default with @command{set print type typedefs}. | |
16065 | @end table | |
16066 | ||
c906108c | 16067 | @kindex ptype |
53342f27 | 16068 | @item ptype[/@var{flags}] [@var{arg}] |
62f3a2ba FF |
16069 | @code{ptype} accepts the same arguments as @code{whatis}, but prints a |
16070 | detailed description of the type, instead of just the name of the type. | |
16071 | @xref{Expressions, ,Expressions}. | |
c906108c | 16072 | |
177bc839 JK |
16073 | Contrary to @code{whatis}, @code{ptype} always unrolls any |
16074 | @code{typedef}s in its argument declaration, whether the argument is | |
16075 | a variable, expression, or a data type. This means that @code{ptype} | |
16076 | of a variable or an expression will not print literally its type as | |
16077 | present in the source code---use @code{whatis} for that. @code{typedef}s at | |
16078 | the pointer or reference targets are also unrolled. Only @code{typedef}s of | |
16079 | fields, methods and inner @code{class typedef}s of @code{struct}s, | |
16080 | @code{class}es and @code{union}s are not unrolled even with @code{ptype}. | |
16081 | ||
c906108c SS |
16082 | For example, for this variable declaration: |
16083 | ||
474c8240 | 16084 | @smallexample |
177bc839 JK |
16085 | typedef double real_t; |
16086 | struct complex @{ real_t real; double imag; @}; | |
16087 | typedef struct complex complex_t; | |
16088 | complex_t var; | |
16089 | real_t *real_pointer_var; | |
474c8240 | 16090 | @end smallexample |
c906108c SS |
16091 | |
16092 | @noindent | |
16093 | the two commands give this output: | |
16094 | ||
474c8240 | 16095 | @smallexample |
c906108c | 16096 | @group |
177bc839 JK |
16097 | (@value{GDBP}) whatis var |
16098 | type = complex_t | |
16099 | (@value{GDBP}) ptype var | |
16100 | type = struct complex @{ | |
16101 | real_t real; | |
16102 | double imag; | |
16103 | @} | |
16104 | (@value{GDBP}) whatis complex_t | |
16105 | type = struct complex | |
16106 | (@value{GDBP}) whatis struct complex | |
c906108c | 16107 | type = struct complex |
177bc839 | 16108 | (@value{GDBP}) ptype struct complex |
c906108c | 16109 | type = struct complex @{ |
177bc839 | 16110 | real_t real; |
c906108c SS |
16111 | double imag; |
16112 | @} | |
177bc839 JK |
16113 | (@value{GDBP}) whatis real_pointer_var |
16114 | type = real_t * | |
16115 | (@value{GDBP}) ptype real_pointer_var | |
16116 | type = double * | |
c906108c | 16117 | @end group |
474c8240 | 16118 | @end smallexample |
c906108c SS |
16119 | |
16120 | @noindent | |
16121 | As with @code{whatis}, using @code{ptype} without an argument refers to | |
16122 | the type of @code{$}, the last value in the value history. | |
16123 | ||
ab1adacd EZ |
16124 | @cindex incomplete type |
16125 | Sometimes, programs use opaque data types or incomplete specifications | |
16126 | of complex data structure. If the debug information included in the | |
16127 | program does not allow @value{GDBN} to display a full declaration of | |
16128 | the data type, it will say @samp{<incomplete type>}. For example, | |
16129 | given these declarations: | |
16130 | ||
16131 | @smallexample | |
16132 | struct foo; | |
16133 | struct foo *fooptr; | |
16134 | @end smallexample | |
16135 | ||
16136 | @noindent | |
16137 | but no definition for @code{struct foo} itself, @value{GDBN} will say: | |
16138 | ||
16139 | @smallexample | |
ddb50cd7 | 16140 | (@value{GDBP}) ptype foo |
ab1adacd EZ |
16141 | $1 = <incomplete type> |
16142 | @end smallexample | |
16143 | ||
16144 | @noindent | |
16145 | ``Incomplete type'' is C terminology for data types that are not | |
16146 | completely specified. | |
16147 | ||
c906108c SS |
16148 | @kindex info types |
16149 | @item info types @var{regexp} | |
16150 | @itemx info types | |
09d4efe1 EZ |
16151 | Print a brief description of all types whose names match the regular |
16152 | expression @var{regexp} (or all types in your program, if you supply | |
16153 | no argument). Each complete typename is matched as though it were a | |
16154 | complete line; thus, @samp{i type value} gives information on all | |
16155 | types in your program whose names include the string @code{value}, but | |
16156 | @samp{i type ^value$} gives information only on types whose complete | |
16157 | name is @code{value}. | |
c906108c SS |
16158 | |
16159 | This command differs from @code{ptype} in two ways: first, like | |
16160 | @code{whatis}, it does not print a detailed description; second, it | |
16161 | lists all source files where a type is defined. | |
16162 | ||
18a9fc12 TT |
16163 | @kindex info type-printers |
16164 | @item info type-printers | |
16165 | Versions of @value{GDBN} that ship with Python scripting enabled may | |
16166 | have ``type printers'' available. When using @command{ptype} or | |
16167 | @command{whatis}, these printers are consulted when the name of a type | |
16168 | is needed. @xref{Type Printing API}, for more information on writing | |
16169 | type printers. | |
16170 | ||
16171 | @code{info type-printers} displays all the available type printers. | |
16172 | ||
16173 | @kindex enable type-printer | |
16174 | @kindex disable type-printer | |
16175 | @item enable type-printer @var{name}@dots{} | |
16176 | @item disable type-printer @var{name}@dots{} | |
16177 | These commands can be used to enable or disable type printers. | |
16178 | ||
b37052ae EZ |
16179 | @kindex info scope |
16180 | @cindex local variables | |
09d4efe1 | 16181 | @item info scope @var{location} |
b37052ae | 16182 | List all the variables local to a particular scope. This command |
09d4efe1 EZ |
16183 | accepts a @var{location} argument---a function name, a source line, or |
16184 | an address preceded by a @samp{*}, and prints all the variables local | |
2a25a5ba EZ |
16185 | to the scope defined by that location. (@xref{Specify Location}, for |
16186 | details about supported forms of @var{location}.) For example: | |
b37052ae EZ |
16187 | |
16188 | @smallexample | |
16189 | (@value{GDBP}) @b{info scope command_line_handler} | |
16190 | Scope for command_line_handler: | |
16191 | Symbol rl is an argument at stack/frame offset 8, length 4. | |
16192 | Symbol linebuffer is in static storage at address 0x150a18, length 4. | |
16193 | Symbol linelength is in static storage at address 0x150a1c, length 4. | |
16194 | Symbol p is a local variable in register $esi, length 4. | |
16195 | Symbol p1 is a local variable in register $ebx, length 4. | |
16196 | Symbol nline is a local variable in register $edx, length 4. | |
16197 | Symbol repeat is a local variable at frame offset -8, length 4. | |
16198 | @end smallexample | |
16199 | ||
f5c37c66 EZ |
16200 | @noindent |
16201 | This command is especially useful for determining what data to collect | |
16202 | during a @dfn{trace experiment}, see @ref{Tracepoint Actions, | |
16203 | collect}. | |
16204 | ||
c906108c SS |
16205 | @kindex info source |
16206 | @item info source | |
919d772c JB |
16207 | Show information about the current source file---that is, the source file for |
16208 | the function containing the current point of execution: | |
16209 | @itemize @bullet | |
16210 | @item | |
16211 | the name of the source file, and the directory containing it, | |
16212 | @item | |
16213 | the directory it was compiled in, | |
16214 | @item | |
16215 | its length, in lines, | |
16216 | @item | |
16217 | which programming language it is written in, | |
16218 | @item | |
16219 | whether the executable includes debugging information for that file, and | |
16220 | if so, what format the information is in (e.g., STABS, Dwarf 2, etc.), and | |
16221 | @item | |
16222 | whether the debugging information includes information about | |
16223 | preprocessor macros. | |
16224 | @end itemize | |
16225 | ||
c906108c SS |
16226 | |
16227 | @kindex info sources | |
16228 | @item info sources | |
16229 | Print the names of all source files in your program for which there is | |
16230 | debugging information, organized into two lists: files whose symbols | |
16231 | have already been read, and files whose symbols will be read when needed. | |
16232 | ||
16233 | @kindex info functions | |
16234 | @item info functions | |
16235 | Print the names and data types of all defined functions. | |
16236 | ||
16237 | @item info functions @var{regexp} | |
16238 | Print the names and data types of all defined functions | |
16239 | whose names contain a match for regular expression @var{regexp}. | |
16240 | Thus, @samp{info fun step} finds all functions whose names | |
16241 | include @code{step}; @samp{info fun ^step} finds those whose names | |
b383017d | 16242 | start with @code{step}. If a function name contains characters |
c1468174 | 16243 | that conflict with the regular expression language (e.g.@: |
1c5dfdad | 16244 | @samp{operator*()}), they may be quoted with a backslash. |
c906108c SS |
16245 | |
16246 | @kindex info variables | |
16247 | @item info variables | |
0fe7935b | 16248 | Print the names and data types of all variables that are defined |
6ca652b0 | 16249 | outside of functions (i.e.@: excluding local variables). |
c906108c SS |
16250 | |
16251 | @item info variables @var{regexp} | |
16252 | Print the names and data types of all variables (except for local | |
16253 | variables) whose names contain a match for regular expression | |
16254 | @var{regexp}. | |
16255 | ||
b37303ee | 16256 | @kindex info classes |
721c2651 | 16257 | @cindex Objective-C, classes and selectors |
b37303ee AF |
16258 | @item info classes |
16259 | @itemx info classes @var{regexp} | |
16260 | Display all Objective-C classes in your program, or | |
16261 | (with the @var{regexp} argument) all those matching a particular regular | |
16262 | expression. | |
16263 | ||
16264 | @kindex info selectors | |
16265 | @item info selectors | |
16266 | @itemx info selectors @var{regexp} | |
16267 | Display all Objective-C selectors in your program, or | |
16268 | (with the @var{regexp} argument) all those matching a particular regular | |
16269 | expression. | |
16270 | ||
c906108c SS |
16271 | @ignore |
16272 | This was never implemented. | |
16273 | @kindex info methods | |
16274 | @item info methods | |
16275 | @itemx info methods @var{regexp} | |
16276 | The @code{info methods} command permits the user to examine all defined | |
b37052ae EZ |
16277 | methods within C@t{++} program, or (with the @var{regexp} argument) a |
16278 | specific set of methods found in the various C@t{++} classes. Many | |
16279 | C@t{++} classes provide a large number of methods. Thus, the output | |
c906108c SS |
16280 | from the @code{ptype} command can be overwhelming and hard to use. The |
16281 | @code{info-methods} command filters the methods, printing only those | |
16282 | which match the regular-expression @var{regexp}. | |
16283 | @end ignore | |
16284 | ||
9c16f35a | 16285 | @cindex opaque data types |
c906108c SS |
16286 | @kindex set opaque-type-resolution |
16287 | @item set opaque-type-resolution on | |
16288 | Tell @value{GDBN} to resolve opaque types. An opaque type is a type | |
16289 | declared as a pointer to a @code{struct}, @code{class}, or | |
16290 | @code{union}---for example, @code{struct MyType *}---that is used in one | |
16291 | source file although the full declaration of @code{struct MyType} is in | |
16292 | another source file. The default is on. | |
16293 | ||
16294 | A change in the setting of this subcommand will not take effect until | |
16295 | the next time symbols for a file are loaded. | |
16296 | ||
16297 | @item set opaque-type-resolution off | |
16298 | Tell @value{GDBN} not to resolve opaque types. In this case, the type | |
16299 | is printed as follows: | |
16300 | @smallexample | |
16301 | @{<no data fields>@} | |
16302 | @end smallexample | |
16303 | ||
16304 | @kindex show opaque-type-resolution | |
16305 | @item show opaque-type-resolution | |
16306 | Show whether opaque types are resolved or not. | |
c906108c | 16307 | |
770e7fc7 DE |
16308 | @kindex set print symbol-loading |
16309 | @cindex print messages when symbols are loaded | |
16310 | @item set print symbol-loading | |
16311 | @itemx set print symbol-loading full | |
16312 | @itemx set print symbol-loading brief | |
16313 | @itemx set print symbol-loading off | |
16314 | The @code{set print symbol-loading} command allows you to control the | |
16315 | printing of messages when @value{GDBN} loads symbol information. | |
16316 | By default a message is printed for the executable and one for each | |
16317 | shared library, and normally this is what you want. However, when | |
16318 | debugging apps with large numbers of shared libraries these messages | |
16319 | can be annoying. | |
16320 | When set to @code{brief} a message is printed for each executable, | |
16321 | and when @value{GDBN} loads a collection of shared libraries at once | |
16322 | it will only print one message regardless of the number of shared | |
16323 | libraries. When set to @code{off} no messages are printed. | |
16324 | ||
16325 | @kindex show print symbol-loading | |
16326 | @item show print symbol-loading | |
16327 | Show whether messages will be printed when a @value{GDBN} command | |
16328 | entered from the keyboard causes symbol information to be loaded. | |
16329 | ||
c906108c SS |
16330 | @kindex maint print symbols |
16331 | @cindex symbol dump | |
16332 | @kindex maint print psymbols | |
16333 | @cindex partial symbol dump | |
7c57fa1e YQ |
16334 | @kindex maint print msymbols |
16335 | @cindex minimal symbol dump | |
c906108c SS |
16336 | @item maint print symbols @var{filename} |
16337 | @itemx maint print psymbols @var{filename} | |
16338 | @itemx maint print msymbols @var{filename} | |
16339 | Write a dump of debugging symbol data into the file @var{filename}. | |
16340 | These commands are used to debug the @value{GDBN} symbol-reading code. Only | |
16341 | symbols with debugging data are included. If you use @samp{maint print | |
16342 | symbols}, @value{GDBN} includes all the symbols for which it has already | |
16343 | collected full details: that is, @var{filename} reflects symbols for | |
16344 | only those files whose symbols @value{GDBN} has read. You can use the | |
16345 | command @code{info sources} to find out which files these are. If you | |
16346 | use @samp{maint print psymbols} instead, the dump shows information about | |
16347 | symbols that @value{GDBN} only knows partially---that is, symbols defined in | |
16348 | files that @value{GDBN} has skimmed, but not yet read completely. Finally, | |
16349 | @samp{maint print msymbols} dumps just the minimal symbol information | |
16350 | required for each object file from which @value{GDBN} has read some symbols. | |
79a6e687 | 16351 | @xref{Files, ,Commands to Specify Files}, for a discussion of how |
c906108c | 16352 | @value{GDBN} reads symbols (in the description of @code{symbol-file}). |
44ea7b70 | 16353 | |
5e7b2f39 JB |
16354 | @kindex maint info symtabs |
16355 | @kindex maint info psymtabs | |
44ea7b70 JB |
16356 | @cindex listing @value{GDBN}'s internal symbol tables |
16357 | @cindex symbol tables, listing @value{GDBN}'s internal | |
16358 | @cindex full symbol tables, listing @value{GDBN}'s internal | |
16359 | @cindex partial symbol tables, listing @value{GDBN}'s internal | |
5e7b2f39 JB |
16360 | @item maint info symtabs @r{[} @var{regexp} @r{]} |
16361 | @itemx maint info psymtabs @r{[} @var{regexp} @r{]} | |
44ea7b70 JB |
16362 | |
16363 | List the @code{struct symtab} or @code{struct partial_symtab} | |
16364 | structures whose names match @var{regexp}. If @var{regexp} is not | |
16365 | given, list them all. The output includes expressions which you can | |
16366 | copy into a @value{GDBN} debugging this one to examine a particular | |
16367 | structure in more detail. For example: | |
16368 | ||
16369 | @smallexample | |
5e7b2f39 | 16370 | (@value{GDBP}) maint info psymtabs dwarf2read |
44ea7b70 JB |
16371 | @{ objfile /home/gnu/build/gdb/gdb |
16372 | ((struct objfile *) 0x82e69d0) | |
b383017d | 16373 | @{ psymtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
16374 | ((struct partial_symtab *) 0x8474b10) |
16375 | readin no | |
16376 | fullname (null) | |
16377 | text addresses 0x814d3c8 -- 0x8158074 | |
16378 | globals (* (struct partial_symbol **) 0x8507a08 @@ 9) | |
16379 | statics (* (struct partial_symbol **) 0x40e95b78 @@ 2882) | |
16380 | dependencies (none) | |
16381 | @} | |
16382 | @} | |
5e7b2f39 | 16383 | (@value{GDBP}) maint info symtabs |
44ea7b70 JB |
16384 | (@value{GDBP}) |
16385 | @end smallexample | |
16386 | @noindent | |
16387 | We see that there is one partial symbol table whose filename contains | |
16388 | the string @samp{dwarf2read}, belonging to the @samp{gdb} executable; | |
16389 | and we see that @value{GDBN} has not read in any symtabs yet at all. | |
16390 | If we set a breakpoint on a function, that will cause @value{GDBN} to | |
16391 | read the symtab for the compilation unit containing that function: | |
16392 | ||
16393 | @smallexample | |
16394 | (@value{GDBP}) break dwarf2_psymtab_to_symtab | |
16395 | Breakpoint 1 at 0x814e5da: file /home/gnu/src/gdb/dwarf2read.c, | |
16396 | line 1574. | |
5e7b2f39 | 16397 | (@value{GDBP}) maint info symtabs |
b383017d | 16398 | @{ objfile /home/gnu/build/gdb/gdb |
44ea7b70 | 16399 | ((struct objfile *) 0x82e69d0) |
b383017d | 16400 | @{ symtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
16401 | ((struct symtab *) 0x86c1f38) |
16402 | dirname (null) | |
16403 | fullname (null) | |
16404 | blockvector ((struct blockvector *) 0x86c1bd0) (primary) | |
1b39d5c0 | 16405 | linetable ((struct linetable *) 0x8370fa0) |
44ea7b70 JB |
16406 | debugformat DWARF 2 |
16407 | @} | |
16408 | @} | |
b383017d | 16409 | (@value{GDBP}) |
44ea7b70 | 16410 | @end smallexample |
c906108c SS |
16411 | @end table |
16412 | ||
44ea7b70 | 16413 | |
6d2ebf8b | 16414 | @node Altering |
c906108c SS |
16415 | @chapter Altering Execution |
16416 | ||
16417 | Once you think you have found an error in your program, you might want to | |
16418 | find out for certain whether correcting the apparent error would lead to | |
16419 | correct results in the rest of the run. You can find the answer by | |
16420 | experiment, using the @value{GDBN} features for altering execution of the | |
16421 | program. | |
16422 | ||
16423 | For example, you can store new values into variables or memory | |
7a292a7a SS |
16424 | locations, give your program a signal, restart it at a different |
16425 | address, or even return prematurely from a function. | |
c906108c SS |
16426 | |
16427 | @menu | |
16428 | * Assignment:: Assignment to variables | |
16429 | * Jumping:: Continuing at a different address | |
c906108c | 16430 | * Signaling:: Giving your program a signal |
c906108c SS |
16431 | * Returning:: Returning from a function |
16432 | * Calling:: Calling your program's functions | |
16433 | * Patching:: Patching your program | |
16434 | @end menu | |
16435 | ||
6d2ebf8b | 16436 | @node Assignment |
79a6e687 | 16437 | @section Assignment to Variables |
c906108c SS |
16438 | |
16439 | @cindex assignment | |
16440 | @cindex setting variables | |
16441 | To alter the value of a variable, evaluate an assignment expression. | |
16442 | @xref{Expressions, ,Expressions}. For example, | |
16443 | ||
474c8240 | 16444 | @smallexample |
c906108c | 16445 | print x=4 |
474c8240 | 16446 | @end smallexample |
c906108c SS |
16447 | |
16448 | @noindent | |
16449 | stores the value 4 into the variable @code{x}, and then prints the | |
5d161b24 | 16450 | value of the assignment expression (which is 4). |
c906108c SS |
16451 | @xref{Languages, ,Using @value{GDBN} with Different Languages}, for more |
16452 | information on operators in supported languages. | |
c906108c SS |
16453 | |
16454 | @kindex set variable | |
16455 | @cindex variables, setting | |
16456 | If you are not interested in seeing the value of the assignment, use the | |
16457 | @code{set} command instead of the @code{print} command. @code{set} is | |
16458 | really the same as @code{print} except that the expression's value is | |
16459 | not printed and is not put in the value history (@pxref{Value History, | |
79a6e687 | 16460 | ,Value History}). The expression is evaluated only for its effects. |
c906108c | 16461 | |
c906108c SS |
16462 | If the beginning of the argument string of the @code{set} command |
16463 | appears identical to a @code{set} subcommand, use the @code{set | |
16464 | variable} command instead of just @code{set}. This command is identical | |
16465 | to @code{set} except for its lack of subcommands. For example, if your | |
16466 | program has a variable @code{width}, you get an error if you try to set | |
16467 | a new value with just @samp{set width=13}, because @value{GDBN} has the | |
16468 | command @code{set width}: | |
16469 | ||
474c8240 | 16470 | @smallexample |
c906108c SS |
16471 | (@value{GDBP}) whatis width |
16472 | type = double | |
16473 | (@value{GDBP}) p width | |
16474 | $4 = 13 | |
16475 | (@value{GDBP}) set width=47 | |
16476 | Invalid syntax in expression. | |
474c8240 | 16477 | @end smallexample |
c906108c SS |
16478 | |
16479 | @noindent | |
16480 | The invalid expression, of course, is @samp{=47}. In | |
16481 | order to actually set the program's variable @code{width}, use | |
16482 | ||
474c8240 | 16483 | @smallexample |
c906108c | 16484 | (@value{GDBP}) set var width=47 |
474c8240 | 16485 | @end smallexample |
53a5351d | 16486 | |
c906108c SS |
16487 | Because the @code{set} command has many subcommands that can conflict |
16488 | with the names of program variables, it is a good idea to use the | |
16489 | @code{set variable} command instead of just @code{set}. For example, if | |
16490 | your program has a variable @code{g}, you run into problems if you try | |
16491 | to set a new value with just @samp{set g=4}, because @value{GDBN} has | |
16492 | the command @code{set gnutarget}, abbreviated @code{set g}: | |
16493 | ||
474c8240 | 16494 | @smallexample |
c906108c SS |
16495 | @group |
16496 | (@value{GDBP}) whatis g | |
16497 | type = double | |
16498 | (@value{GDBP}) p g | |
16499 | $1 = 1 | |
16500 | (@value{GDBP}) set g=4 | |
2df3850c | 16501 | (@value{GDBP}) p g |
c906108c SS |
16502 | $2 = 1 |
16503 | (@value{GDBP}) r | |
16504 | The program being debugged has been started already. | |
16505 | Start it from the beginning? (y or n) y | |
16506 | Starting program: /home/smith/cc_progs/a.out | |
6d2ebf8b SS |
16507 | "/home/smith/cc_progs/a.out": can't open to read symbols: |
16508 | Invalid bfd target. | |
c906108c SS |
16509 | (@value{GDBP}) show g |
16510 | The current BFD target is "=4". | |
16511 | @end group | |
474c8240 | 16512 | @end smallexample |
c906108c SS |
16513 | |
16514 | @noindent | |
16515 | The program variable @code{g} did not change, and you silently set the | |
16516 | @code{gnutarget} to an invalid value. In order to set the variable | |
16517 | @code{g}, use | |
16518 | ||
474c8240 | 16519 | @smallexample |
c906108c | 16520 | (@value{GDBP}) set var g=4 |
474c8240 | 16521 | @end smallexample |
c906108c SS |
16522 | |
16523 | @value{GDBN} allows more implicit conversions in assignments than C; you can | |
16524 | freely store an integer value into a pointer variable or vice versa, | |
16525 | and you can convert any structure to any other structure that is the | |
16526 | same length or shorter. | |
16527 | @comment FIXME: how do structs align/pad in these conversions? | |
16528 | @comment /doc@cygnus.com 18dec1990 | |
16529 | ||
16530 | To store values into arbitrary places in memory, use the @samp{@{@dots{}@}} | |
16531 | construct to generate a value of specified type at a specified address | |
16532 | (@pxref{Expressions, ,Expressions}). For example, @code{@{int@}0x83040} refers | |
16533 | to memory location @code{0x83040} as an integer (which implies a certain size | |
16534 | and representation in memory), and | |
16535 | ||
474c8240 | 16536 | @smallexample |
c906108c | 16537 | set @{int@}0x83040 = 4 |
474c8240 | 16538 | @end smallexample |
c906108c SS |
16539 | |
16540 | @noindent | |
16541 | stores the value 4 into that memory location. | |
16542 | ||
6d2ebf8b | 16543 | @node Jumping |
79a6e687 | 16544 | @section Continuing at a Different Address |
c906108c SS |
16545 | |
16546 | Ordinarily, when you continue your program, you do so at the place where | |
16547 | it stopped, with the @code{continue} command. You can instead continue at | |
16548 | an address of your own choosing, with the following commands: | |
16549 | ||
16550 | @table @code | |
16551 | @kindex jump | |
c1d780c2 | 16552 | @kindex j @r{(@code{jump})} |
c906108c | 16553 | @item jump @var{linespec} |
c1d780c2 | 16554 | @itemx j @var{linespec} |
2a25a5ba | 16555 | @itemx jump @var{location} |
c1d780c2 | 16556 | @itemx j @var{location} |
2a25a5ba EZ |
16557 | Resume execution at line @var{linespec} or at address given by |
16558 | @var{location}. Execution stops again immediately if there is a | |
16559 | breakpoint there. @xref{Specify Location}, for a description of the | |
16560 | different forms of @var{linespec} and @var{location}. It is common | |
16561 | practice to use the @code{tbreak} command in conjunction with | |
16562 | @code{jump}. @xref{Set Breaks, ,Setting Breakpoints}. | |
c906108c SS |
16563 | |
16564 | The @code{jump} command does not change the current stack frame, or | |
16565 | the stack pointer, or the contents of any memory location or any | |
16566 | register other than the program counter. If line @var{linespec} is in | |
16567 | a different function from the one currently executing, the results may | |
16568 | be bizarre if the two functions expect different patterns of arguments or | |
16569 | of local variables. For this reason, the @code{jump} command requests | |
16570 | confirmation if the specified line is not in the function currently | |
16571 | executing. However, even bizarre results are predictable if you are | |
16572 | well acquainted with the machine-language code of your program. | |
c906108c SS |
16573 | @end table |
16574 | ||
c906108c | 16575 | @c Doesn't work on HP-UX; have to set $pcoqh and $pcoqt. |
53a5351d JM |
16576 | On many systems, you can get much the same effect as the @code{jump} |
16577 | command by storing a new value into the register @code{$pc}. The | |
16578 | difference is that this does not start your program running; it only | |
16579 | changes the address of where it @emph{will} run when you continue. For | |
16580 | example, | |
c906108c | 16581 | |
474c8240 | 16582 | @smallexample |
c906108c | 16583 | set $pc = 0x485 |
474c8240 | 16584 | @end smallexample |
c906108c SS |
16585 | |
16586 | @noindent | |
16587 | makes the next @code{continue} command or stepping command execute at | |
16588 | address @code{0x485}, rather than at the address where your program stopped. | |
79a6e687 | 16589 | @xref{Continuing and Stepping, ,Continuing and Stepping}. |
c906108c SS |
16590 | |
16591 | The most common occasion to use the @code{jump} command is to back | |
16592 | up---perhaps with more breakpoints set---over a portion of a program | |
16593 | that has already executed, in order to examine its execution in more | |
16594 | detail. | |
16595 | ||
c906108c | 16596 | @c @group |
6d2ebf8b | 16597 | @node Signaling |
79a6e687 | 16598 | @section Giving your Program a Signal |
9c16f35a | 16599 | @cindex deliver a signal to a program |
c906108c SS |
16600 | |
16601 | @table @code | |
16602 | @kindex signal | |
16603 | @item signal @var{signal} | |
70509625 | 16604 | Resume execution where your program is stopped, but immediately give it the |
697aa1b7 | 16605 | signal @var{signal}. The @var{signal} can be the name or the number of a |
c906108c SS |
16606 | signal. For example, on many systems @code{signal 2} and @code{signal |
16607 | SIGINT} are both ways of sending an interrupt signal. | |
16608 | ||
16609 | Alternatively, if @var{signal} is zero, continue execution without | |
16610 | giving a signal. This is useful when your program stopped on account of | |
ae606bee | 16611 | a signal and would ordinarily see the signal when resumed with the |
c906108c SS |
16612 | @code{continue} command; @samp{signal 0} causes it to resume without a |
16613 | signal. | |
16614 | ||
70509625 PA |
16615 | @emph{Note:} When resuming a multi-threaded program, @var{signal} is |
16616 | delivered to the currently selected thread, not the thread that last | |
16617 | reported a stop. This includes the situation where a thread was | |
16618 | stopped due to a signal. So if you want to continue execution | |
16619 | suppressing the signal that stopped a thread, you should select that | |
16620 | same thread before issuing the @samp{signal 0} command. If you issue | |
16621 | the @samp{signal 0} command with another thread as the selected one, | |
16622 | @value{GDBN} detects that and asks for confirmation. | |
16623 | ||
c906108c SS |
16624 | Invoking the @code{signal} command is not the same as invoking the |
16625 | @code{kill} utility from the shell. Sending a signal with @code{kill} | |
16626 | causes @value{GDBN} to decide what to do with the signal depending on | |
16627 | the signal handling tables (@pxref{Signals}). The @code{signal} command | |
16628 | passes the signal directly to your program. | |
16629 | ||
81219e53 DE |
16630 | @code{signal} does not repeat when you press @key{RET} a second time |
16631 | after executing the command. | |
16632 | ||
16633 | @kindex queue-signal | |
16634 | @item queue-signal @var{signal} | |
16635 | Queue @var{signal} to be delivered immediately to the current thread | |
16636 | when execution of the thread resumes. The @var{signal} can be the name or | |
16637 | the number of a signal. For example, on many systems @code{signal 2} and | |
16638 | @code{signal SIGINT} are both ways of sending an interrupt signal. | |
16639 | The handling of the signal must be set to pass the signal to the program, | |
16640 | otherwise @value{GDBN} will report an error. | |
16641 | You can control the handling of signals from @value{GDBN} with the | |
16642 | @code{handle} command (@pxref{Signals}). | |
16643 | ||
16644 | Alternatively, if @var{signal} is zero, any currently queued signal | |
16645 | for the current thread is discarded and when execution resumes no signal | |
16646 | will be delivered. This is useful when your program stopped on account | |
16647 | of a signal and would ordinarily see the signal when resumed with the | |
16648 | @code{continue} command. | |
16649 | ||
16650 | This command differs from the @code{signal} command in that the signal | |
16651 | is just queued, execution is not resumed. And @code{queue-signal} cannot | |
16652 | be used to pass a signal whose handling state has been set to @code{nopass} | |
16653 | (@pxref{Signals}). | |
16654 | @end table | |
16655 | @c @end group | |
c906108c | 16656 | |
6d2ebf8b | 16657 | @node Returning |
79a6e687 | 16658 | @section Returning from a Function |
c906108c SS |
16659 | |
16660 | @table @code | |
16661 | @cindex returning from a function | |
16662 | @kindex return | |
16663 | @item return | |
16664 | @itemx return @var{expression} | |
16665 | You can cancel execution of a function call with the @code{return} | |
16666 | command. If you give an | |
16667 | @var{expression} argument, its value is used as the function's return | |
16668 | value. | |
16669 | @end table | |
16670 | ||
16671 | When you use @code{return}, @value{GDBN} discards the selected stack frame | |
16672 | (and all frames within it). You can think of this as making the | |
16673 | discarded frame return prematurely. If you wish to specify a value to | |
16674 | be returned, give that value as the argument to @code{return}. | |
16675 | ||
16676 | This pops the selected stack frame (@pxref{Selection, ,Selecting a | |
79a6e687 | 16677 | Frame}), and any other frames inside of it, leaving its caller as the |
c906108c SS |
16678 | innermost remaining frame. That frame becomes selected. The |
16679 | specified value is stored in the registers used for returning values | |
16680 | of functions. | |
16681 | ||
16682 | The @code{return} command does not resume execution; it leaves the | |
16683 | program stopped in the state that would exist if the function had just | |
16684 | returned. In contrast, the @code{finish} command (@pxref{Continuing | |
79a6e687 | 16685 | and Stepping, ,Continuing and Stepping}) resumes execution until the |
c906108c SS |
16686 | selected stack frame returns naturally. |
16687 | ||
61ff14c6 JK |
16688 | @value{GDBN} needs to know how the @var{expression} argument should be set for |
16689 | the inferior. The concrete registers assignment depends on the OS ABI and the | |
16690 | type being returned by the selected stack frame. For example it is common for | |
16691 | OS ABI to return floating point values in FPU registers while integer values in | |
16692 | CPU registers. Still some ABIs return even floating point values in CPU | |
16693 | registers. Larger integer widths (such as @code{long long int}) also have | |
16694 | specific placement rules. @value{GDBN} already knows the OS ABI from its | |
16695 | current target so it needs to find out also the type being returned to make the | |
16696 | assignment into the right register(s). | |
16697 | ||
16698 | Normally, the selected stack frame has debug info. @value{GDBN} will always | |
16699 | use the debug info instead of the implicit type of @var{expression} when the | |
16700 | debug info is available. For example, if you type @kbd{return -1}, and the | |
16701 | function in the current stack frame is declared to return a @code{long long | |
16702 | int}, @value{GDBN} transparently converts the implicit @code{int} value of -1 | |
16703 | into a @code{long long int}: | |
16704 | ||
16705 | @smallexample | |
16706 | Breakpoint 1, func () at gdb.base/return-nodebug.c:29 | |
16707 | 29 return 31; | |
16708 | (@value{GDBP}) return -1 | |
16709 | Make func return now? (y or n) y | |
16710 | #0 0x004004f6 in main () at gdb.base/return-nodebug.c:43 | |
16711 | 43 printf ("result=%lld\n", func ()); | |
16712 | (@value{GDBP}) | |
16713 | @end smallexample | |
16714 | ||
16715 | However, if the selected stack frame does not have a debug info, e.g., if the | |
16716 | function was compiled without debug info, @value{GDBN} has to find out the type | |
16717 | to return from user. Specifying a different type by mistake may set the value | |
16718 | in different inferior registers than the caller code expects. For example, | |
16719 | typing @kbd{return -1} with its implicit type @code{int} would set only a part | |
16720 | of a @code{long long int} result for a debug info less function (on 32-bit | |
16721 | architectures). Therefore the user is required to specify the return type by | |
16722 | an appropriate cast explicitly: | |
16723 | ||
16724 | @smallexample | |
16725 | Breakpoint 2, 0x0040050b in func () | |
16726 | (@value{GDBP}) return -1 | |
16727 | Return value type not available for selected stack frame. | |
16728 | Please use an explicit cast of the value to return. | |
16729 | (@value{GDBP}) return (long long int) -1 | |
16730 | Make selected stack frame return now? (y or n) y | |
16731 | #0 0x00400526 in main () | |
16732 | (@value{GDBP}) | |
16733 | @end smallexample | |
16734 | ||
6d2ebf8b | 16735 | @node Calling |
79a6e687 | 16736 | @section Calling Program Functions |
c906108c | 16737 | |
f8568604 | 16738 | @table @code |
c906108c | 16739 | @cindex calling functions |
f8568604 EZ |
16740 | @cindex inferior functions, calling |
16741 | @item print @var{expr} | |
d3e8051b | 16742 | Evaluate the expression @var{expr} and display the resulting value. |
697aa1b7 | 16743 | The expression may include calls to functions in the program being |
f8568604 EZ |
16744 | debugged. |
16745 | ||
c906108c | 16746 | @kindex call |
c906108c SS |
16747 | @item call @var{expr} |
16748 | Evaluate the expression @var{expr} without displaying @code{void} | |
16749 | returned values. | |
c906108c SS |
16750 | |
16751 | You can use this variant of the @code{print} command if you want to | |
f8568604 EZ |
16752 | execute a function from your program that does not return anything |
16753 | (a.k.a.@: @dfn{a void function}), but without cluttering the output | |
16754 | with @code{void} returned values that @value{GDBN} will otherwise | |
16755 | print. If the result is not void, it is printed and saved in the | |
16756 | value history. | |
16757 | @end table | |
16758 | ||
9c16f35a EZ |
16759 | It is possible for the function you call via the @code{print} or |
16760 | @code{call} command to generate a signal (e.g., if there's a bug in | |
16761 | the function, or if you passed it incorrect arguments). What happens | |
16762 | in that case is controlled by the @code{set unwindonsignal} command. | |
16763 | ||
7cd1089b PM |
16764 | Similarly, with a C@t{++} program it is possible for the function you |
16765 | call via the @code{print} or @code{call} command to generate an | |
16766 | exception that is not handled due to the constraints of the dummy | |
16767 | frame. In this case, any exception that is raised in the frame, but has | |
16768 | an out-of-frame exception handler will not be found. GDB builds a | |
16769 | dummy-frame for the inferior function call, and the unwinder cannot | |
16770 | seek for exception handlers outside of this dummy-frame. What happens | |
16771 | in that case is controlled by the | |
16772 | @code{set unwind-on-terminating-exception} command. | |
16773 | ||
9c16f35a EZ |
16774 | @table @code |
16775 | @item set unwindonsignal | |
16776 | @kindex set unwindonsignal | |
16777 | @cindex unwind stack in called functions | |
16778 | @cindex call dummy stack unwinding | |
16779 | Set unwinding of the stack if a signal is received while in a function | |
16780 | that @value{GDBN} called in the program being debugged. If set to on, | |
16781 | @value{GDBN} unwinds the stack it created for the call and restores | |
16782 | the context to what it was before the call. If set to off (the | |
16783 | default), @value{GDBN} stops in the frame where the signal was | |
16784 | received. | |
16785 | ||
16786 | @item show unwindonsignal | |
16787 | @kindex show unwindonsignal | |
16788 | Show the current setting of stack unwinding in the functions called by | |
16789 | @value{GDBN}. | |
7cd1089b PM |
16790 | |
16791 | @item set unwind-on-terminating-exception | |
16792 | @kindex set unwind-on-terminating-exception | |
16793 | @cindex unwind stack in called functions with unhandled exceptions | |
16794 | @cindex call dummy stack unwinding on unhandled exception. | |
16795 | Set unwinding of the stack if a C@t{++} exception is raised, but left | |
16796 | unhandled while in a function that @value{GDBN} called in the program being | |
16797 | debugged. If set to on (the default), @value{GDBN} unwinds the stack | |
16798 | it created for the call and restores the context to what it was before | |
16799 | the call. If set to off, @value{GDBN} the exception is delivered to | |
16800 | the default C@t{++} exception handler and the inferior terminated. | |
16801 | ||
16802 | @item show unwind-on-terminating-exception | |
16803 | @kindex show unwind-on-terminating-exception | |
16804 | Show the current setting of stack unwinding in the functions called by | |
16805 | @value{GDBN}. | |
16806 | ||
9c16f35a EZ |
16807 | @end table |
16808 | ||
f8568604 EZ |
16809 | @cindex weak alias functions |
16810 | Sometimes, a function you wish to call is actually a @dfn{weak alias} | |
16811 | for another function. In such case, @value{GDBN} might not pick up | |
16812 | the type information, including the types of the function arguments, | |
16813 | which causes @value{GDBN} to call the inferior function incorrectly. | |
16814 | As a result, the called function will function erroneously and may | |
16815 | even crash. A solution to that is to use the name of the aliased | |
16816 | function instead. | |
c906108c | 16817 | |
6d2ebf8b | 16818 | @node Patching |
79a6e687 | 16819 | @section Patching Programs |
7a292a7a | 16820 | |
c906108c SS |
16821 | @cindex patching binaries |
16822 | @cindex writing into executables | |
c906108c | 16823 | @cindex writing into corefiles |
c906108c | 16824 | |
7a292a7a SS |
16825 | By default, @value{GDBN} opens the file containing your program's |
16826 | executable code (or the corefile) read-only. This prevents accidental | |
16827 | alterations to machine code; but it also prevents you from intentionally | |
16828 | patching your program's binary. | |
c906108c SS |
16829 | |
16830 | If you'd like to be able to patch the binary, you can specify that | |
16831 | explicitly with the @code{set write} command. For example, you might | |
16832 | want to turn on internal debugging flags, or even to make emergency | |
16833 | repairs. | |
16834 | ||
16835 | @table @code | |
16836 | @kindex set write | |
16837 | @item set write on | |
16838 | @itemx set write off | |
7a292a7a | 16839 | If you specify @samp{set write on}, @value{GDBN} opens executable and |
20924a55 | 16840 | core files for both reading and writing; if you specify @kbd{set write |
c906108c SS |
16841 | off} (the default), @value{GDBN} opens them read-only. |
16842 | ||
16843 | If you have already loaded a file, you must load it again (using the | |
7a292a7a SS |
16844 | @code{exec-file} or @code{core-file} command) after changing @code{set |
16845 | write}, for your new setting to take effect. | |
c906108c SS |
16846 | |
16847 | @item show write | |
16848 | @kindex show write | |
7a292a7a SS |
16849 | Display whether executable files and core files are opened for writing |
16850 | as well as reading. | |
c906108c SS |
16851 | @end table |
16852 | ||
6d2ebf8b | 16853 | @node GDB Files |
c906108c SS |
16854 | @chapter @value{GDBN} Files |
16855 | ||
7a292a7a SS |
16856 | @value{GDBN} needs to know the file name of the program to be debugged, |
16857 | both in order to read its symbol table and in order to start your | |
16858 | program. To debug a core dump of a previous run, you must also tell | |
16859 | @value{GDBN} the name of the core dump file. | |
c906108c SS |
16860 | |
16861 | @menu | |
16862 | * Files:: Commands to specify files | |
5b5d99cf | 16863 | * Separate Debug Files:: Debugging information in separate files |
608e2dbb | 16864 | * MiniDebugInfo:: Debugging information in a special section |
9291a0cd | 16865 | * Index Files:: Index files speed up GDB |
c906108c | 16866 | * Symbol Errors:: Errors reading symbol files |
b14b1491 | 16867 | * Data Files:: GDB data files |
c906108c SS |
16868 | @end menu |
16869 | ||
6d2ebf8b | 16870 | @node Files |
79a6e687 | 16871 | @section Commands to Specify Files |
c906108c | 16872 | |
7a292a7a | 16873 | @cindex symbol table |
c906108c | 16874 | @cindex core dump file |
7a292a7a SS |
16875 | |
16876 | You may want to specify executable and core dump file names. The usual | |
16877 | way to do this is at start-up time, using the arguments to | |
16878 | @value{GDBN}'s start-up commands (@pxref{Invocation, , Getting In and | |
16879 | Out of @value{GDBN}}). | |
c906108c SS |
16880 | |
16881 | Occasionally it is necessary to change to a different file during a | |
397ca115 EZ |
16882 | @value{GDBN} session. Or you may run @value{GDBN} and forget to |
16883 | specify a file you want to use. Or you are debugging a remote target | |
79a6e687 BW |
16884 | via @code{gdbserver} (@pxref{Server, file, Using the @code{gdbserver} |
16885 | Program}). In these situations the @value{GDBN} commands to specify | |
0869d01b | 16886 | new files are useful. |
c906108c SS |
16887 | |
16888 | @table @code | |
16889 | @cindex executable file | |
16890 | @kindex file | |
16891 | @item file @var{filename} | |
16892 | Use @var{filename} as the program to be debugged. It is read for its | |
16893 | symbols and for the contents of pure memory. It is also the program | |
16894 | executed when you use the @code{run} command. If you do not specify a | |
5d161b24 DB |
16895 | directory and the file is not found in the @value{GDBN} working directory, |
16896 | @value{GDBN} uses the environment variable @code{PATH} as a list of | |
16897 | directories to search, just as the shell does when looking for a program | |
16898 | to run. You can change the value of this variable, for both @value{GDBN} | |
c906108c SS |
16899 | and your program, using the @code{path} command. |
16900 | ||
fc8be69e EZ |
16901 | @cindex unlinked object files |
16902 | @cindex patching object files | |
16903 | You can load unlinked object @file{.o} files into @value{GDBN} using | |
16904 | the @code{file} command. You will not be able to ``run'' an object | |
16905 | file, but you can disassemble functions and inspect variables. Also, | |
16906 | if the underlying BFD functionality supports it, you could use | |
16907 | @kbd{gdb -write} to patch object files using this technique. Note | |
16908 | that @value{GDBN} can neither interpret nor modify relocations in this | |
16909 | case, so branches and some initialized variables will appear to go to | |
16910 | the wrong place. But this feature is still handy from time to time. | |
16911 | ||
c906108c SS |
16912 | @item file |
16913 | @code{file} with no argument makes @value{GDBN} discard any information it | |
16914 | has on both executable file and the symbol table. | |
16915 | ||
16916 | @kindex exec-file | |
16917 | @item exec-file @r{[} @var{filename} @r{]} | |
16918 | Specify that the program to be run (but not the symbol table) is found | |
16919 | in @var{filename}. @value{GDBN} searches the environment variable @code{PATH} | |
16920 | if necessary to locate your program. Omitting @var{filename} means to | |
16921 | discard information on the executable file. | |
16922 | ||
16923 | @kindex symbol-file | |
16924 | @item symbol-file @r{[} @var{filename} @r{]} | |
16925 | Read symbol table information from file @var{filename}. @code{PATH} is | |
16926 | searched when necessary. Use the @code{file} command to get both symbol | |
16927 | table and program to run from the same file. | |
16928 | ||
16929 | @code{symbol-file} with no argument clears out @value{GDBN} information on your | |
16930 | program's symbol table. | |
16931 | ||
ae5a43e0 DJ |
16932 | The @code{symbol-file} command causes @value{GDBN} to forget the contents of |
16933 | some breakpoints and auto-display expressions. This is because they may | |
16934 | contain pointers to the internal data recording symbols and data types, | |
16935 | which are part of the old symbol table data being discarded inside | |
16936 | @value{GDBN}. | |
c906108c SS |
16937 | |
16938 | @code{symbol-file} does not repeat if you press @key{RET} again after | |
16939 | executing it once. | |
16940 | ||
16941 | When @value{GDBN} is configured for a particular environment, it | |
16942 | understands debugging information in whatever format is the standard | |
16943 | generated for that environment; you may use either a @sc{gnu} compiler, or | |
16944 | other compilers that adhere to the local conventions. | |
c906108c | 16945 | Best results are usually obtained from @sc{gnu} compilers; for example, |
e22ea452 | 16946 | using @code{@value{NGCC}} you can generate debugging information for |
c906108c | 16947 | optimized code. |
c906108c SS |
16948 | |
16949 | For most kinds of object files, with the exception of old SVR3 systems | |
16950 | using COFF, the @code{symbol-file} command does not normally read the | |
16951 | symbol table in full right away. Instead, it scans the symbol table | |
16952 | quickly to find which source files and which symbols are present. The | |
16953 | details are read later, one source file at a time, as they are needed. | |
16954 | ||
16955 | The purpose of this two-stage reading strategy is to make @value{GDBN} | |
16956 | start up faster. For the most part, it is invisible except for | |
16957 | occasional pauses while the symbol table details for a particular source | |
16958 | file are being read. (The @code{set verbose} command can turn these | |
16959 | pauses into messages if desired. @xref{Messages/Warnings, ,Optional | |
79a6e687 | 16960 | Warnings and Messages}.) |
c906108c | 16961 | |
c906108c SS |
16962 | We have not implemented the two-stage strategy for COFF yet. When the |
16963 | symbol table is stored in COFF format, @code{symbol-file} reads the | |
16964 | symbol table data in full right away. Note that ``stabs-in-COFF'' | |
16965 | still does the two-stage strategy, since the debug info is actually | |
16966 | in stabs format. | |
16967 | ||
16968 | @kindex readnow | |
16969 | @cindex reading symbols immediately | |
16970 | @cindex symbols, reading immediately | |
6ac33a4e TT |
16971 | @item symbol-file @r{[} -readnow @r{]} @var{filename} |
16972 | @itemx file @r{[} -readnow @r{]} @var{filename} | |
c906108c SS |
16973 | You can override the @value{GDBN} two-stage strategy for reading symbol |
16974 | tables by using the @samp{-readnow} option with any of the commands that | |
16975 | load symbol table information, if you want to be sure @value{GDBN} has the | |
5d161b24 | 16976 | entire symbol table available. |
c906108c | 16977 | |
c906108c SS |
16978 | @c FIXME: for now no mention of directories, since this seems to be in |
16979 | @c flux. 13mar1992 status is that in theory GDB would look either in | |
16980 | @c current dir or in same dir as myprog; but issues like competing | |
16981 | @c GDB's, or clutter in system dirs, mean that in practice right now | |
16982 | @c only current dir is used. FFish says maybe a special GDB hierarchy | |
16983 | @c (eg rooted in val of env var GDBSYMS) could exist for mappable symbol | |
16984 | @c files. | |
16985 | ||
c906108c | 16986 | @kindex core-file |
09d4efe1 | 16987 | @item core-file @r{[}@var{filename}@r{]} |
4644b6e3 | 16988 | @itemx core |
c906108c SS |
16989 | Specify the whereabouts of a core dump file to be used as the ``contents |
16990 | of memory''. Traditionally, core files contain only some parts of the | |
16991 | address space of the process that generated them; @value{GDBN} can access the | |
16992 | executable file itself for other parts. | |
16993 | ||
16994 | @code{core-file} with no argument specifies that no core file is | |
16995 | to be used. | |
16996 | ||
16997 | Note that the core file is ignored when your program is actually running | |
7a292a7a SS |
16998 | under @value{GDBN}. So, if you have been running your program and you |
16999 | wish to debug a core file instead, you must kill the subprocess in which | |
17000 | the program is running. To do this, use the @code{kill} command | |
79a6e687 | 17001 | (@pxref{Kill Process, ,Killing the Child Process}). |
c906108c | 17002 | |
c906108c SS |
17003 | @kindex add-symbol-file |
17004 | @cindex dynamic linking | |
17005 | @item add-symbol-file @var{filename} @var{address} | |
a94ab193 | 17006 | @itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]} |
24bdad53 | 17007 | @itemx add-symbol-file @var{filename} @var{address} -s @var{section} @var{address} @dots{} |
96a2c332 SS |
17008 | The @code{add-symbol-file} command reads additional symbol table |
17009 | information from the file @var{filename}. You would use this command | |
17010 | when @var{filename} has been dynamically loaded (by some other means) | |
697aa1b7 | 17011 | into the program that is running. The @var{address} should give the memory |
96a2c332 | 17012 | address at which the file has been loaded; @value{GDBN} cannot figure |
d167840f | 17013 | this out for itself. You can additionally specify an arbitrary number |
24bdad53 | 17014 | of @samp{-s @var{section} @var{address}} pairs, to give an explicit |
d167840f EZ |
17015 | section name and base address for that section. You can specify any |
17016 | @var{address} as an expression. | |
c906108c SS |
17017 | |
17018 | The symbol table of the file @var{filename} is added to the symbol table | |
17019 | originally read with the @code{symbol-file} command. You can use the | |
96a2c332 | 17020 | @code{add-symbol-file} command any number of times; the new symbol data |
98297bf6 NB |
17021 | thus read is kept in addition to the old. |
17022 | ||
17023 | Changes can be reverted using the command @code{remove-symbol-file}. | |
c906108c | 17024 | |
17d9d558 JB |
17025 | @cindex relocatable object files, reading symbols from |
17026 | @cindex object files, relocatable, reading symbols from | |
17027 | @cindex reading symbols from relocatable object files | |
17028 | @cindex symbols, reading from relocatable object files | |
17029 | @cindex @file{.o} files, reading symbols from | |
17030 | Although @var{filename} is typically a shared library file, an | |
17031 | executable file, or some other object file which has been fully | |
17032 | relocated for loading into a process, you can also load symbolic | |
17033 | information from relocatable @file{.o} files, as long as: | |
17034 | ||
17035 | @itemize @bullet | |
17036 | @item | |
17037 | the file's symbolic information refers only to linker symbols defined in | |
17038 | that file, not to symbols defined by other object files, | |
17039 | @item | |
17040 | every section the file's symbolic information refers to has actually | |
17041 | been loaded into the inferior, as it appears in the file, and | |
17042 | @item | |
17043 | you can determine the address at which every section was loaded, and | |
17044 | provide these to the @code{add-symbol-file} command. | |
17045 | @end itemize | |
17046 | ||
17047 | @noindent | |
17048 | Some embedded operating systems, like Sun Chorus and VxWorks, can load | |
17049 | relocatable files into an already running program; such systems | |
17050 | typically make the requirements above easy to meet. However, it's | |
17051 | important to recognize that many native systems use complex link | |
49efadf5 | 17052 | procedures (@code{.linkonce} section factoring and C@t{++} constructor table |
17d9d558 JB |
17053 | assembly, for example) that make the requirements difficult to meet. In |
17054 | general, one cannot assume that using @code{add-symbol-file} to read a | |
17055 | relocatable object file's symbolic information will have the same effect | |
17056 | as linking the relocatable object file into the program in the normal | |
17057 | way. | |
17058 | ||
c906108c SS |
17059 | @code{add-symbol-file} does not repeat if you press @key{RET} after using it. |
17060 | ||
98297bf6 NB |
17061 | @kindex remove-symbol-file |
17062 | @item remove-symbol-file @var{filename} | |
17063 | @item remove-symbol-file -a @var{address} | |
17064 | Remove a symbol file added via the @code{add-symbol-file} command. The | |
17065 | file to remove can be identified by its @var{filename} or by an @var{address} | |
17066 | that lies within the boundaries of this symbol file in memory. Example: | |
17067 | ||
17068 | @smallexample | |
17069 | (gdb) add-symbol-file /home/user/gdb/mylib.so 0x7ffff7ff9480 | |
17070 | add symbol table from file "/home/user/gdb/mylib.so" at | |
17071 | .text_addr = 0x7ffff7ff9480 | |
17072 | (y or n) y | |
17073 | Reading symbols from /home/user/gdb/mylib.so...done. | |
17074 | (gdb) remove-symbol-file -a 0x7ffff7ff9480 | |
17075 | Remove symbol table from file "/home/user/gdb/mylib.so"? (y or n) y | |
17076 | (gdb) | |
17077 | @end smallexample | |
17078 | ||
17079 | ||
17080 | @code{remove-symbol-file} does not repeat if you press @key{RET} after using it. | |
17081 | ||
c45da7e6 EZ |
17082 | @kindex add-symbol-file-from-memory |
17083 | @cindex @code{syscall DSO} | |
17084 | @cindex load symbols from memory | |
17085 | @item add-symbol-file-from-memory @var{address} | |
17086 | Load symbols from the given @var{address} in a dynamically loaded | |
17087 | object file whose image is mapped directly into the inferior's memory. | |
17088 | For example, the Linux kernel maps a @code{syscall DSO} into each | |
17089 | process's address space; this DSO provides kernel-specific code for | |
17090 | some system calls. The argument can be any expression whose | |
17091 | evaluation yields the address of the file's shared object file header. | |
17092 | For this command to work, you must have used @code{symbol-file} or | |
17093 | @code{exec-file} commands in advance. | |
17094 | ||
09d4efe1 EZ |
17095 | @kindex add-shared-symbol-files |
17096 | @kindex assf | |
17097 | @item add-shared-symbol-files @var{library-file} | |
17098 | @itemx assf @var{library-file} | |
95060284 JB |
17099 | This command is deprecated and will be removed in future versions |
17100 | of @value{GDBN}. Use the @code{sharedlibrary} command instead. | |
17101 | ||
09d4efe1 EZ |
17102 | The @code{add-shared-symbol-files} command can currently be used only |
17103 | in the Cygwin build of @value{GDBN} on MS-Windows OS, where it is an | |
17104 | alias for the @code{dll-symbols} command (@pxref{Cygwin Native}). | |
17105 | @value{GDBN} automatically looks for shared libraries, however if | |
17106 | @value{GDBN} does not find yours, you can invoke | |
17107 | @code{add-shared-symbol-files}. It takes one argument: the shared | |
17108 | library's file name. @code{assf} is a shorthand alias for | |
17109 | @code{add-shared-symbol-files}. | |
c906108c | 17110 | |
c906108c | 17111 | @kindex section |
09d4efe1 EZ |
17112 | @item section @var{section} @var{addr} |
17113 | The @code{section} command changes the base address of the named | |
17114 | @var{section} of the exec file to @var{addr}. This can be used if the | |
17115 | exec file does not contain section addresses, (such as in the | |
17116 | @code{a.out} format), or when the addresses specified in the file | |
17117 | itself are wrong. Each section must be changed separately. The | |
17118 | @code{info files} command, described below, lists all the sections and | |
17119 | their addresses. | |
c906108c SS |
17120 | |
17121 | @kindex info files | |
17122 | @kindex info target | |
17123 | @item info files | |
17124 | @itemx info target | |
7a292a7a SS |
17125 | @code{info files} and @code{info target} are synonymous; both print the |
17126 | current target (@pxref{Targets, ,Specifying a Debugging Target}), | |
17127 | including the names of the executable and core dump files currently in | |
17128 | use by @value{GDBN}, and the files from which symbols were loaded. The | |
17129 | command @code{help target} lists all possible targets rather than | |
17130 | current ones. | |
17131 | ||
fe95c787 MS |
17132 | @kindex maint info sections |
17133 | @item maint info sections | |
17134 | Another command that can give you extra information about program sections | |
17135 | is @code{maint info sections}. In addition to the section information | |
17136 | displayed by @code{info files}, this command displays the flags and file | |
17137 | offset of each section in the executable and core dump files. In addition, | |
17138 | @code{maint info sections} provides the following command options (which | |
17139 | may be arbitrarily combined): | |
17140 | ||
17141 | @table @code | |
17142 | @item ALLOBJ | |
17143 | Display sections for all loaded object files, including shared libraries. | |
17144 | @item @var{sections} | |
6600abed | 17145 | Display info only for named @var{sections}. |
fe95c787 MS |
17146 | @item @var{section-flags} |
17147 | Display info only for sections for which @var{section-flags} are true. | |
17148 | The section flags that @value{GDBN} currently knows about are: | |
17149 | @table @code | |
17150 | @item ALLOC | |
17151 | Section will have space allocated in the process when loaded. | |
17152 | Set for all sections except those containing debug information. | |
17153 | @item LOAD | |
17154 | Section will be loaded from the file into the child process memory. | |
17155 | Set for pre-initialized code and data, clear for @code{.bss} sections. | |
17156 | @item RELOC | |
17157 | Section needs to be relocated before loading. | |
17158 | @item READONLY | |
17159 | Section cannot be modified by the child process. | |
17160 | @item CODE | |
17161 | Section contains executable code only. | |
6600abed | 17162 | @item DATA |
fe95c787 MS |
17163 | Section contains data only (no executable code). |
17164 | @item ROM | |
17165 | Section will reside in ROM. | |
17166 | @item CONSTRUCTOR | |
17167 | Section contains data for constructor/destructor lists. | |
17168 | @item HAS_CONTENTS | |
17169 | Section is not empty. | |
17170 | @item NEVER_LOAD | |
17171 | An instruction to the linker to not output the section. | |
17172 | @item COFF_SHARED_LIBRARY | |
17173 | A notification to the linker that the section contains | |
17174 | COFF shared library information. | |
17175 | @item IS_COMMON | |
17176 | Section contains common symbols. | |
17177 | @end table | |
17178 | @end table | |
6763aef9 | 17179 | @kindex set trust-readonly-sections |
9c16f35a | 17180 | @cindex read-only sections |
6763aef9 MS |
17181 | @item set trust-readonly-sections on |
17182 | Tell @value{GDBN} that readonly sections in your object file | |
6ca652b0 | 17183 | really are read-only (i.e.@: that their contents will not change). |
6763aef9 MS |
17184 | In that case, @value{GDBN} can fetch values from these sections |
17185 | out of the object file, rather than from the target program. | |
17186 | For some targets (notably embedded ones), this can be a significant | |
17187 | enhancement to debugging performance. | |
17188 | ||
17189 | The default is off. | |
17190 | ||
17191 | @item set trust-readonly-sections off | |
15110bc3 | 17192 | Tell @value{GDBN} not to trust readonly sections. This means that |
6763aef9 MS |
17193 | the contents of the section might change while the program is running, |
17194 | and must therefore be fetched from the target when needed. | |
9c16f35a EZ |
17195 | |
17196 | @item show trust-readonly-sections | |
17197 | Show the current setting of trusting readonly sections. | |
c906108c SS |
17198 | @end table |
17199 | ||
17200 | All file-specifying commands allow both absolute and relative file names | |
17201 | as arguments. @value{GDBN} always converts the file name to an absolute file | |
17202 | name and remembers it that way. | |
17203 | ||
c906108c | 17204 | @cindex shared libraries |
9cceb671 DJ |
17205 | @anchor{Shared Libraries} |
17206 | @value{GDBN} supports @sc{gnu}/Linux, MS-Windows, HP-UX, SunOS, SVr4, Irix, | |
9c16f35a | 17207 | and IBM RS/6000 AIX shared libraries. |
53a5351d | 17208 | |
9cceb671 DJ |
17209 | On MS-Windows @value{GDBN} must be linked with the Expat library to support |
17210 | shared libraries. @xref{Expat}. | |
17211 | ||
c906108c SS |
17212 | @value{GDBN} automatically loads symbol definitions from shared libraries |
17213 | when you use the @code{run} command, or when you examine a core file. | |
17214 | (Before you issue the @code{run} command, @value{GDBN} does not understand | |
17215 | references to a function in a shared library, however---unless you are | |
17216 | debugging a core file). | |
53a5351d JM |
17217 | |
17218 | On HP-UX, if the program loads a library explicitly, @value{GDBN} | |
17219 | automatically loads the symbols at the time of the @code{shl_load} call. | |
17220 | ||
c906108c SS |
17221 | @c FIXME: some @value{GDBN} release may permit some refs to undef |
17222 | @c FIXME...symbols---eg in a break cmd---assuming they are from a shared | |
17223 | @c FIXME...lib; check this from time to time when updating manual | |
17224 | ||
b7209cb4 FF |
17225 | There are times, however, when you may wish to not automatically load |
17226 | symbol definitions from shared libraries, such as when they are | |
17227 | particularly large or there are many of them. | |
17228 | ||
17229 | To control the automatic loading of shared library symbols, use the | |
17230 | commands: | |
17231 | ||
17232 | @table @code | |
17233 | @kindex set auto-solib-add | |
17234 | @item set auto-solib-add @var{mode} | |
17235 | If @var{mode} is @code{on}, symbols from all shared object libraries | |
17236 | will be loaded automatically when the inferior begins execution, you | |
17237 | attach to an independently started inferior, or when the dynamic linker | |
17238 | informs @value{GDBN} that a new library has been loaded. If @var{mode} | |
17239 | is @code{off}, symbols must be loaded manually, using the | |
17240 | @code{sharedlibrary} command. The default value is @code{on}. | |
17241 | ||
dcaf7c2c EZ |
17242 | @cindex memory used for symbol tables |
17243 | If your program uses lots of shared libraries with debug info that | |
17244 | takes large amounts of memory, you can decrease the @value{GDBN} | |
17245 | memory footprint by preventing it from automatically loading the | |
17246 | symbols from shared libraries. To that end, type @kbd{set | |
17247 | auto-solib-add off} before running the inferior, then load each | |
17248 | library whose debug symbols you do need with @kbd{sharedlibrary | |
d3e8051b | 17249 | @var{regexp}}, where @var{regexp} is a regular expression that matches |
dcaf7c2c EZ |
17250 | the libraries whose symbols you want to be loaded. |
17251 | ||
b7209cb4 FF |
17252 | @kindex show auto-solib-add |
17253 | @item show auto-solib-add | |
17254 | Display the current autoloading mode. | |
17255 | @end table | |
17256 | ||
c45da7e6 | 17257 | @cindex load shared library |
b7209cb4 FF |
17258 | To explicitly load shared library symbols, use the @code{sharedlibrary} |
17259 | command: | |
17260 | ||
c906108c SS |
17261 | @table @code |
17262 | @kindex info sharedlibrary | |
17263 | @kindex info share | |
55333a84 DE |
17264 | @item info share @var{regex} |
17265 | @itemx info sharedlibrary @var{regex} | |
17266 | Print the names of the shared libraries which are currently loaded | |
17267 | that match @var{regex}. If @var{regex} is omitted then print | |
17268 | all shared libraries that are loaded. | |
c906108c SS |
17269 | |
17270 | @kindex sharedlibrary | |
17271 | @kindex share | |
17272 | @item sharedlibrary @var{regex} | |
17273 | @itemx share @var{regex} | |
c906108c SS |
17274 | Load shared object library symbols for files matching a |
17275 | Unix regular expression. | |
17276 | As with files loaded automatically, it only loads shared libraries | |
17277 | required by your program for a core file or after typing @code{run}. If | |
17278 | @var{regex} is omitted all shared libraries required by your program are | |
17279 | loaded. | |
c45da7e6 EZ |
17280 | |
17281 | @item nosharedlibrary | |
17282 | @kindex nosharedlibrary | |
17283 | @cindex unload symbols from shared libraries | |
17284 | Unload all shared object library symbols. This discards all symbols | |
17285 | that have been loaded from all shared libraries. Symbols from shared | |
17286 | libraries that were loaded by explicit user requests are not | |
17287 | discarded. | |
c906108c SS |
17288 | @end table |
17289 | ||
721c2651 | 17290 | Sometimes you may wish that @value{GDBN} stops and gives you control |
edcc5120 TT |
17291 | when any of shared library events happen. The best way to do this is |
17292 | to use @code{catch load} and @code{catch unload} (@pxref{Set | |
17293 | Catchpoints}). | |
17294 | ||
17295 | @value{GDBN} also supports the the @code{set stop-on-solib-events} | |
17296 | command for this. This command exists for historical reasons. It is | |
17297 | less useful than setting a catchpoint, because it does not allow for | |
17298 | conditions or commands as a catchpoint does. | |
721c2651 EZ |
17299 | |
17300 | @table @code | |
17301 | @item set stop-on-solib-events | |
17302 | @kindex set stop-on-solib-events | |
17303 | This command controls whether @value{GDBN} should give you control | |
17304 | when the dynamic linker notifies it about some shared library event. | |
17305 | The most common event of interest is loading or unloading of a new | |
17306 | shared library. | |
17307 | ||
17308 | @item show stop-on-solib-events | |
17309 | @kindex show stop-on-solib-events | |
17310 | Show whether @value{GDBN} stops and gives you control when shared | |
17311 | library events happen. | |
17312 | @end table | |
17313 | ||
f5ebfba0 | 17314 | Shared libraries are also supported in many cross or remote debugging |
f1838a98 UW |
17315 | configurations. @value{GDBN} needs to have access to the target's libraries; |
17316 | this can be accomplished either by providing copies of the libraries | |
17317 | on the host system, or by asking @value{GDBN} to automatically retrieve the | |
17318 | libraries from the target. If copies of the target libraries are | |
17319 | provided, they need to be the same as the target libraries, although the | |
f5ebfba0 DJ |
17320 | copies on the target can be stripped as long as the copies on the host are |
17321 | not. | |
17322 | ||
59b7b46f EZ |
17323 | @cindex where to look for shared libraries |
17324 | For remote debugging, you need to tell @value{GDBN} where the target | |
17325 | libraries are, so that it can load the correct copies---otherwise, it | |
17326 | may try to load the host's libraries. @value{GDBN} has two variables | |
17327 | to specify the search directories for target libraries. | |
f5ebfba0 DJ |
17328 | |
17329 | @table @code | |
59b7b46f | 17330 | @cindex prefix for shared library file names |
f822c95b | 17331 | @cindex system root, alternate |
f5ebfba0 | 17332 | @kindex set solib-absolute-prefix |
f822c95b DJ |
17333 | @kindex set sysroot |
17334 | @item set sysroot @var{path} | |
17335 | Use @var{path} as the system root for the program being debugged. Any | |
17336 | absolute shared library paths will be prefixed with @var{path}; many | |
17337 | runtime loaders store the absolute paths to the shared library in the | |
17338 | target program's memory. If you use @code{set sysroot} to find shared | |
17339 | libraries, they need to be laid out in the same way that they are on | |
17340 | the target, with e.g.@: a @file{/lib} and @file{/usr/lib} hierarchy | |
17341 | under @var{path}. | |
17342 | ||
f1838a98 UW |
17343 | If @var{path} starts with the sequence @file{remote:}, @value{GDBN} will |
17344 | retrieve the target libraries from the remote system. This is only | |
17345 | supported when using a remote target that supports the @code{remote get} | |
17346 | command (@pxref{File Transfer,,Sending files to a remote system}). | |
17347 | The part of @var{path} following the initial @file{remote:} | |
17348 | (if present) is used as system root prefix on the remote file system. | |
17349 | @footnote{If you want to specify a local system root using a directory | |
17350 | that happens to be named @file{remote:}, you need to use some equivalent | |
17351 | variant of the name like @file{./remote:}.} | |
17352 | ||
ab38a727 PA |
17353 | For targets with an MS-DOS based filesystem, such as MS-Windows and |
17354 | SymbianOS, @value{GDBN} tries prefixing a few variants of the target | |
17355 | absolute file name with @var{path}. But first, on Unix hosts, | |
17356 | @value{GDBN} converts all backslash directory separators into forward | |
17357 | slashes, because the backslash is not a directory separator on Unix: | |
17358 | ||
17359 | @smallexample | |
17360 | c:\foo\bar.dll @result{} c:/foo/bar.dll | |
17361 | @end smallexample | |
17362 | ||
17363 | Then, @value{GDBN} attempts prefixing the target file name with | |
17364 | @var{path}, and looks for the resulting file name in the host file | |
17365 | system: | |
17366 | ||
17367 | @smallexample | |
17368 | c:/foo/bar.dll @result{} /path/to/sysroot/c:/foo/bar.dll | |
17369 | @end smallexample | |
17370 | ||
17371 | If that does not find the shared library, @value{GDBN} tries removing | |
17372 | the @samp{:} character from the drive spec, both for convenience, and, | |
17373 | for the case of the host file system not supporting file names with | |
17374 | colons: | |
17375 | ||
17376 | @smallexample | |
17377 | c:/foo/bar.dll @result{} /path/to/sysroot/c/foo/bar.dll | |
17378 | @end smallexample | |
17379 | ||
17380 | This makes it possible to have a system root that mirrors a target | |
17381 | with more than one drive. E.g., you may want to setup your local | |
17382 | copies of the target system shared libraries like so (note @samp{c} vs | |
17383 | @samp{z}): | |
17384 | ||
17385 | @smallexample | |
17386 | @file{/path/to/sysroot/c/sys/bin/foo.dll} | |
17387 | @file{/path/to/sysroot/c/sys/bin/bar.dll} | |
17388 | @file{/path/to/sysroot/z/sys/bin/bar.dll} | |
17389 | @end smallexample | |
17390 | ||
17391 | @noindent | |
17392 | and point the system root at @file{/path/to/sysroot}, so that | |
17393 | @value{GDBN} can find the correct copies of both | |
17394 | @file{c:\sys\bin\foo.dll}, and @file{z:\sys\bin\bar.dll}. | |
17395 | ||
17396 | If that still does not find the shared library, @value{GDBN} tries | |
17397 | removing the whole drive spec from the target file name: | |
17398 | ||
17399 | @smallexample | |
17400 | c:/foo/bar.dll @result{} /path/to/sysroot/foo/bar.dll | |
17401 | @end smallexample | |
17402 | ||
17403 | This last lookup makes it possible to not care about the drive name, | |
17404 | if you don't want or need to. | |
17405 | ||
f822c95b DJ |
17406 | The @code{set solib-absolute-prefix} command is an alias for @code{set |
17407 | sysroot}. | |
17408 | ||
17409 | @cindex default system root | |
59b7b46f | 17410 | @cindex @samp{--with-sysroot} |
f822c95b DJ |
17411 | You can set the default system root by using the configure-time |
17412 | @samp{--with-sysroot} option. If the system root is inside | |
17413 | @value{GDBN}'s configured binary prefix (set with @samp{--prefix} or | |
17414 | @samp{--exec-prefix}), then the default system root will be updated | |
17415 | automatically if the installed @value{GDBN} is moved to a new | |
17416 | location. | |
17417 | ||
17418 | @kindex show sysroot | |
17419 | @item show sysroot | |
f5ebfba0 DJ |
17420 | Display the current shared library prefix. |
17421 | ||
17422 | @kindex set solib-search-path | |
17423 | @item set solib-search-path @var{path} | |
f822c95b DJ |
17424 | If this variable is set, @var{path} is a colon-separated list of |
17425 | directories to search for shared libraries. @samp{solib-search-path} | |
17426 | is used after @samp{sysroot} fails to locate the library, or if the | |
17427 | path to the library is relative instead of absolute. If you want to | |
17428 | use @samp{solib-search-path} instead of @samp{sysroot}, be sure to set | |
d3e8051b | 17429 | @samp{sysroot} to a nonexistent directory to prevent @value{GDBN} from |
f822c95b | 17430 | finding your host's libraries. @samp{sysroot} is preferred; setting |
d3e8051b | 17431 | it to a nonexistent directory may interfere with automatic loading |
f822c95b | 17432 | of shared library symbols. |
f5ebfba0 DJ |
17433 | |
17434 | @kindex show solib-search-path | |
17435 | @item show solib-search-path | |
17436 | Display the current shared library search path. | |
ab38a727 PA |
17437 | |
17438 | @cindex DOS file-name semantics of file names. | |
17439 | @kindex set target-file-system-kind (unix|dos-based|auto) | |
17440 | @kindex show target-file-system-kind | |
17441 | @item set target-file-system-kind @var{kind} | |
17442 | Set assumed file system kind for target reported file names. | |
17443 | ||
17444 | Shared library file names as reported by the target system may not | |
17445 | make sense as is on the system @value{GDBN} is running on. For | |
17446 | example, when remote debugging a target that has MS-DOS based file | |
17447 | system semantics, from a Unix host, the target may be reporting to | |
17448 | @value{GDBN} a list of loaded shared libraries with file names such as | |
17449 | @file{c:\Windows\kernel32.dll}. On Unix hosts, there's no concept of | |
17450 | drive letters, so the @samp{c:\} prefix is not normally understood as | |
17451 | indicating an absolute file name, and neither is the backslash | |
17452 | normally considered a directory separator character. In that case, | |
17453 | the native file system would interpret this whole absolute file name | |
17454 | as a relative file name with no directory components. This would make | |
17455 | it impossible to point @value{GDBN} at a copy of the remote target's | |
17456 | shared libraries on the host using @code{set sysroot}, and impractical | |
17457 | with @code{set solib-search-path}. Setting | |
17458 | @code{target-file-system-kind} to @code{dos-based} tells @value{GDBN} | |
17459 | to interpret such file names similarly to how the target would, and to | |
17460 | map them to file names valid on @value{GDBN}'s native file system | |
17461 | semantics. The value of @var{kind} can be @code{"auto"}, in addition | |
17462 | to one of the supported file system kinds. In that case, @value{GDBN} | |
17463 | tries to determine the appropriate file system variant based on the | |
17464 | current target's operating system (@pxref{ABI, ,Configuring the | |
17465 | Current ABI}). The supported file system settings are: | |
17466 | ||
17467 | @table @code | |
17468 | @item unix | |
17469 | Instruct @value{GDBN} to assume the target file system is of Unix | |
17470 | kind. Only file names starting the forward slash (@samp{/}) character | |
17471 | are considered absolute, and the directory separator character is also | |
17472 | the forward slash. | |
17473 | ||
17474 | @item dos-based | |
17475 | Instruct @value{GDBN} to assume the target file system is DOS based. | |
17476 | File names starting with either a forward slash, or a drive letter | |
17477 | followed by a colon (e.g., @samp{c:}), are considered absolute, and | |
17478 | both the slash (@samp{/}) and the backslash (@samp{\\}) characters are | |
17479 | considered directory separators. | |
17480 | ||
17481 | @item auto | |
17482 | Instruct @value{GDBN} to use the file system kind associated with the | |
17483 | target operating system (@pxref{ABI, ,Configuring the Current ABI}). | |
17484 | This is the default. | |
17485 | @end table | |
f5ebfba0 DJ |
17486 | @end table |
17487 | ||
c011a4f4 DE |
17488 | @cindex file name canonicalization |
17489 | @cindex base name differences | |
17490 | When processing file names provided by the user, @value{GDBN} | |
17491 | frequently needs to compare them to the file names recorded in the | |
17492 | program's debug info. Normally, @value{GDBN} compares just the | |
17493 | @dfn{base names} of the files as strings, which is reasonably fast | |
17494 | even for very large programs. (The base name of a file is the last | |
17495 | portion of its name, after stripping all the leading directories.) | |
17496 | This shortcut in comparison is based upon the assumption that files | |
17497 | cannot have more than one base name. This is usually true, but | |
17498 | references to files that use symlinks or similar filesystem | |
17499 | facilities violate that assumption. If your program records files | |
17500 | using such facilities, or if you provide file names to @value{GDBN} | |
17501 | using symlinks etc., you can set @code{basenames-may-differ} to | |
17502 | @code{true} to instruct @value{GDBN} to completely canonicalize each | |
17503 | pair of file names it needs to compare. This will make file-name | |
17504 | comparisons accurate, but at a price of a significant slowdown. | |
17505 | ||
17506 | @table @code | |
17507 | @item set basenames-may-differ | |
17508 | @kindex set basenames-may-differ | |
17509 | Set whether a source file may have multiple base names. | |
17510 | ||
17511 | @item show basenames-may-differ | |
17512 | @kindex show basenames-may-differ | |
17513 | Show whether a source file may have multiple base names. | |
17514 | @end table | |
5b5d99cf JB |
17515 | |
17516 | @node Separate Debug Files | |
17517 | @section Debugging Information in Separate Files | |
17518 | @cindex separate debugging information files | |
17519 | @cindex debugging information in separate files | |
17520 | @cindex @file{.debug} subdirectories | |
17521 | @cindex debugging information directory, global | |
f307c045 | 17522 | @cindex global debugging information directories |
c7e83d54 EZ |
17523 | @cindex build ID, and separate debugging files |
17524 | @cindex @file{.build-id} directory | |
5b5d99cf JB |
17525 | |
17526 | @value{GDBN} allows you to put a program's debugging information in a | |
17527 | file separate from the executable itself, in a way that allows | |
17528 | @value{GDBN} to find and load the debugging information automatically. | |
c7e83d54 EZ |
17529 | Since debugging information can be very large---sometimes larger |
17530 | than the executable code itself---some systems distribute debugging | |
5b5d99cf JB |
17531 | information for their executables in separate files, which users can |
17532 | install only when they need to debug a problem. | |
17533 | ||
c7e83d54 EZ |
17534 | @value{GDBN} supports two ways of specifying the separate debug info |
17535 | file: | |
5b5d99cf JB |
17536 | |
17537 | @itemize @bullet | |
17538 | @item | |
c7e83d54 EZ |
17539 | The executable contains a @dfn{debug link} that specifies the name of |
17540 | the separate debug info file. The separate debug file's name is | |
17541 | usually @file{@var{executable}.debug}, where @var{executable} is the | |
17542 | name of the corresponding executable file without leading directories | |
17543 | (e.g., @file{ls.debug} for @file{/usr/bin/ls}). In addition, the | |
99e008fe EZ |
17544 | debug link specifies a 32-bit @dfn{Cyclic Redundancy Check} (CRC) |
17545 | checksum for the debug file, which @value{GDBN} uses to validate that | |
17546 | the executable and the debug file came from the same build. | |
c7e83d54 EZ |
17547 | |
17548 | @item | |
7e27a47a | 17549 | The executable contains a @dfn{build ID}, a unique bit string that is |
c7e83d54 | 17550 | also present in the corresponding debug info file. (This is supported |
7e27a47a EZ |
17551 | only on some operating systems, notably those which use the ELF format |
17552 | for binary files and the @sc{gnu} Binutils.) For more details about | |
17553 | this feature, see the description of the @option{--build-id} | |
17554 | command-line option in @ref{Options, , Command Line Options, ld.info, | |
17555 | The GNU Linker}. The debug info file's name is not specified | |
17556 | explicitly by the build ID, but can be computed from the build ID, see | |
17557 | below. | |
d3750b24 JK |
17558 | @end itemize |
17559 | ||
c7e83d54 EZ |
17560 | Depending on the way the debug info file is specified, @value{GDBN} |
17561 | uses two different methods of looking for the debug file: | |
d3750b24 JK |
17562 | |
17563 | @itemize @bullet | |
17564 | @item | |
c7e83d54 EZ |
17565 | For the ``debug link'' method, @value{GDBN} looks up the named file in |
17566 | the directory of the executable file, then in a subdirectory of that | |
f307c045 JK |
17567 | directory named @file{.debug}, and finally under each one of the global debug |
17568 | directories, in a subdirectory whose name is identical to the leading | |
c7e83d54 EZ |
17569 | directories of the executable's absolute file name. |
17570 | ||
17571 | @item | |
83f83d7f | 17572 | For the ``build ID'' method, @value{GDBN} looks in the |
f307c045 JK |
17573 | @file{.build-id} subdirectory of each one of the global debug directories for |
17574 | a file named @file{@var{nn}/@var{nnnnnnnn}.debug}, where @var{nn} are the | |
7e27a47a EZ |
17575 | first 2 hex characters of the build ID bit string, and @var{nnnnnnnn} |
17576 | are the rest of the bit string. (Real build ID strings are 32 or more | |
17577 | hex characters, not 10.) | |
c7e83d54 EZ |
17578 | @end itemize |
17579 | ||
17580 | So, for example, suppose you ask @value{GDBN} to debug | |
7e27a47a EZ |
17581 | @file{/usr/bin/ls}, which has a debug link that specifies the |
17582 | file @file{ls.debug}, and a build ID whose value in hex is | |
f307c045 | 17583 | @code{abcdef1234}. If the list of the global debug directories includes |
c7e83d54 EZ |
17584 | @file{/usr/lib/debug}, then @value{GDBN} will look for the following |
17585 | debug information files, in the indicated order: | |
17586 | ||
17587 | @itemize @minus | |
17588 | @item | |
17589 | @file{/usr/lib/debug/.build-id/ab/cdef1234.debug} | |
d3750b24 | 17590 | @item |
c7e83d54 | 17591 | @file{/usr/bin/ls.debug} |
5b5d99cf | 17592 | @item |
c7e83d54 | 17593 | @file{/usr/bin/.debug/ls.debug} |
5b5d99cf | 17594 | @item |
c7e83d54 | 17595 | @file{/usr/lib/debug/usr/bin/ls.debug}. |
5b5d99cf | 17596 | @end itemize |
5b5d99cf | 17597 | |
1564a261 JK |
17598 | @anchor{debug-file-directory} |
17599 | Global debugging info directories default to what is set by @value{GDBN} | |
17600 | configure option @option{--with-separate-debug-dir}. During @value{GDBN} run | |
17601 | you can also set the global debugging info directories, and view the list | |
17602 | @value{GDBN} is currently using. | |
5b5d99cf JB |
17603 | |
17604 | @table @code | |
17605 | ||
17606 | @kindex set debug-file-directory | |
24ddea62 JK |
17607 | @item set debug-file-directory @var{directories} |
17608 | Set the directories which @value{GDBN} searches for separate debugging | |
d9242c17 JK |
17609 | information files to @var{directory}. Multiple path components can be set |
17610 | concatenating them by a path separator. | |
5b5d99cf JB |
17611 | |
17612 | @kindex show debug-file-directory | |
17613 | @item show debug-file-directory | |
24ddea62 | 17614 | Show the directories @value{GDBN} searches for separate debugging |
5b5d99cf JB |
17615 | information files. |
17616 | ||
17617 | @end table | |
17618 | ||
17619 | @cindex @code{.gnu_debuglink} sections | |
c7e83d54 | 17620 | @cindex debug link sections |
5b5d99cf JB |
17621 | A debug link is a special section of the executable file named |
17622 | @code{.gnu_debuglink}. The section must contain: | |
17623 | ||
17624 | @itemize | |
17625 | @item | |
17626 | A filename, with any leading directory components removed, followed by | |
17627 | a zero byte, | |
17628 | @item | |
17629 | zero to three bytes of padding, as needed to reach the next four-byte | |
17630 | boundary within the section, and | |
17631 | @item | |
17632 | a four-byte CRC checksum, stored in the same endianness used for the | |
17633 | executable file itself. The checksum is computed on the debugging | |
17634 | information file's full contents by the function given below, passing | |
17635 | zero as the @var{crc} argument. | |
17636 | @end itemize | |
17637 | ||
17638 | Any executable file format can carry a debug link, as long as it can | |
17639 | contain a section named @code{.gnu_debuglink} with the contents | |
17640 | described above. | |
17641 | ||
d3750b24 | 17642 | @cindex @code{.note.gnu.build-id} sections |
c7e83d54 | 17643 | @cindex build ID sections |
7e27a47a EZ |
17644 | The build ID is a special section in the executable file (and in other |
17645 | ELF binary files that @value{GDBN} may consider). This section is | |
17646 | often named @code{.note.gnu.build-id}, but that name is not mandatory. | |
17647 | It contains unique identification for the built files---the ID remains | |
17648 | the same across multiple builds of the same build tree. The default | |
17649 | algorithm SHA1 produces 160 bits (40 hexadecimal characters) of the | |
17650 | content for the build ID string. The same section with an identical | |
17651 | value is present in the original built binary with symbols, in its | |
17652 | stripped variant, and in the separate debugging information file. | |
d3750b24 | 17653 | |
5b5d99cf JB |
17654 | The debugging information file itself should be an ordinary |
17655 | executable, containing a full set of linker symbols, sections, and | |
17656 | debugging information. The sections of the debugging information file | |
c7e83d54 EZ |
17657 | should have the same names, addresses, and sizes as the original file, |
17658 | but they need not contain any data---much like a @code{.bss} section | |
5b5d99cf JB |
17659 | in an ordinary executable. |
17660 | ||
7e27a47a | 17661 | The @sc{gnu} binary utilities (Binutils) package includes the |
c7e83d54 EZ |
17662 | @samp{objcopy} utility that can produce |
17663 | the separated executable / debugging information file pairs using the | |
17664 | following commands: | |
17665 | ||
17666 | @smallexample | |
17667 | @kbd{objcopy --only-keep-debug foo foo.debug} | |
17668 | @kbd{strip -g foo} | |
c7e83d54 EZ |
17669 | @end smallexample |
17670 | ||
17671 | @noindent | |
17672 | These commands remove the debugging | |
83f83d7f JK |
17673 | information from the executable file @file{foo} and place it in the file |
17674 | @file{foo.debug}. You can use the first, second or both methods to link the | |
17675 | two files: | |
17676 | ||
17677 | @itemize @bullet | |
17678 | @item | |
17679 | The debug link method needs the following additional command to also leave | |
17680 | behind a debug link in @file{foo}: | |
17681 | ||
17682 | @smallexample | |
17683 | @kbd{objcopy --add-gnu-debuglink=foo.debug foo} | |
17684 | @end smallexample | |
17685 | ||
17686 | Ulrich Drepper's @file{elfutils} package, starting with version 0.53, contains | |
d3750b24 | 17687 | a version of the @code{strip} command such that the command @kbd{strip foo -f |
83f83d7f JK |
17688 | foo.debug} has the same functionality as the two @code{objcopy} commands and |
17689 | the @code{ln -s} command above, together. | |
17690 | ||
17691 | @item | |
17692 | Build ID gets embedded into the main executable using @code{ld --build-id} or | |
17693 | the @value{NGCC} counterpart @code{gcc -Wl,--build-id}. Build ID support plus | |
17694 | compatibility fixes for debug files separation are present in @sc{gnu} binary | |
7e27a47a | 17695 | utilities (Binutils) package since version 2.18. |
83f83d7f JK |
17696 | @end itemize |
17697 | ||
17698 | @noindent | |
d3750b24 | 17699 | |
99e008fe EZ |
17700 | @cindex CRC algorithm definition |
17701 | The CRC used in @code{.gnu_debuglink} is the CRC-32 defined in | |
17702 | IEEE 802.3 using the polynomial: | |
17703 | ||
17704 | @c TexInfo requires naked braces for multi-digit exponents for Tex | |
17705 | @c output, but this causes HTML output to barf. HTML has to be set using | |
17706 | @c raw commands. So we end up having to specify this equation in 2 | |
17707 | @c different ways! | |
17708 | @ifhtml | |
17709 | @display | |
17710 | @html | |
17711 | <em>x</em><sup>32</sup> + <em>x</em><sup>26</sup> + <em>x</em><sup>23</sup> + <em>x</em><sup>22</sup> + <em>x</em><sup>16</sup> + <em>x</em><sup>12</sup> + <em>x</em><sup>11</sup> | |
17712 | + <em>x</em><sup>10</sup> + <em>x</em><sup>8</sup> + <em>x</em><sup>7</sup> + <em>x</em><sup>5</sup> + <em>x</em><sup>4</sup> + <em>x</em><sup>2</sup> + <em>x</em> + 1 | |
17713 | @end html | |
17714 | @end display | |
17715 | @end ifhtml | |
17716 | @ifnothtml | |
17717 | @display | |
17718 | @math{x^{32} + x^{26} + x^{23} + x^{22} + x^{16} + x^{12} + x^{11}} | |
17719 | @math{+ x^{10} + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1} | |
17720 | @end display | |
17721 | @end ifnothtml | |
17722 | ||
17723 | The function is computed byte at a time, taking the least | |
17724 | significant bit of each byte first. The initial pattern | |
17725 | @code{0xffffffff} is used, to ensure leading zeros affect the CRC and | |
17726 | the final result is inverted to ensure trailing zeros also affect the | |
17727 | CRC. | |
17728 | ||
17729 | @emph{Note:} This is the same CRC polynomial as used in handling the | |
936d2992 PA |
17730 | @dfn{Remote Serial Protocol} @code{qCRC} packet (@pxref{qCRC packet}). |
17731 | However in the case of the Remote Serial Protocol, the CRC is computed | |
17732 | @emph{most} significant bit first, and the result is not inverted, so | |
17733 | trailing zeros have no effect on the CRC value. | |
99e008fe EZ |
17734 | |
17735 | To complete the description, we show below the code of the function | |
17736 | which produces the CRC used in @code{.gnu_debuglink}. Inverting the | |
17737 | initially supplied @code{crc} argument means that an initial call to | |
17738 | this function passing in zero will start computing the CRC using | |
17739 | @code{0xffffffff}. | |
5b5d99cf | 17740 | |
4644b6e3 | 17741 | @kindex gnu_debuglink_crc32 |
5b5d99cf JB |
17742 | @smallexample |
17743 | unsigned long | |
17744 | gnu_debuglink_crc32 (unsigned long crc, | |
17745 | unsigned char *buf, size_t len) | |
17746 | @{ | |
17747 | static const unsigned long crc32_table[256] = | |
17748 | @{ | |
17749 | 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, | |
17750 | 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, | |
17751 | 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, | |
17752 | 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, | |
17753 | 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, | |
17754 | 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, | |
17755 | 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, | |
17756 | 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, | |
17757 | 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, | |
17758 | 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, | |
17759 | 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, | |
17760 | 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, | |
17761 | 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, | |
17762 | 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, | |
17763 | 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, | |
17764 | 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, | |
17765 | 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, | |
17766 | 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, | |
17767 | 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, | |
17768 | 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, | |
17769 | 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, | |
17770 | 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, | |
17771 | 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, | |
17772 | 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, | |
17773 | 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, | |
17774 | 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, | |
17775 | 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, | |
17776 | 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, | |
17777 | 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, | |
17778 | 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, | |
17779 | 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, | |
17780 | 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, | |
17781 | 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, | |
17782 | 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, | |
17783 | 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, | |
17784 | 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, | |
17785 | 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, | |
17786 | 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, | |
17787 | 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, | |
17788 | 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, | |
17789 | 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, | |
17790 | 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, | |
17791 | 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, | |
17792 | 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, | |
17793 | 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, | |
17794 | 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, | |
17795 | 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, | |
17796 | 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, | |
17797 | 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, | |
17798 | 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, | |
17799 | 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, | |
17800 | 0x2d02ef8d | |
17801 | @}; | |
17802 | unsigned char *end; | |
17803 | ||
17804 | crc = ~crc & 0xffffffff; | |
17805 | for (end = buf + len; buf < end; ++buf) | |
17806 | crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); | |
e7a3abfc | 17807 | return ~crc & 0xffffffff; |
5b5d99cf JB |
17808 | @} |
17809 | @end smallexample | |
17810 | ||
c7e83d54 EZ |
17811 | @noindent |
17812 | This computation does not apply to the ``build ID'' method. | |
17813 | ||
608e2dbb TT |
17814 | @node MiniDebugInfo |
17815 | @section Debugging information in a special section | |
17816 | @cindex separate debug sections | |
17817 | @cindex @samp{.gnu_debugdata} section | |
17818 | ||
17819 | Some systems ship pre-built executables and libraries that have a | |
17820 | special @samp{.gnu_debugdata} section. This feature is called | |
17821 | @dfn{MiniDebugInfo}. This section holds an LZMA-compressed object and | |
17822 | is used to supply extra symbols for backtraces. | |
17823 | ||
17824 | The intent of this section is to provide extra minimal debugging | |
17825 | information for use in simple backtraces. It is not intended to be a | |
17826 | replacement for full separate debugging information (@pxref{Separate | |
17827 | Debug Files}). The example below shows the intended use; however, | |
17828 | @value{GDBN} does not currently put restrictions on what sort of | |
17829 | debugging information might be included in the section. | |
17830 | ||
17831 | @value{GDBN} has support for this extension. If the section exists, | |
17832 | then it is used provided that no other source of debugging information | |
17833 | can be found, and that @value{GDBN} was configured with LZMA support. | |
17834 | ||
17835 | This section can be easily created using @command{objcopy} and other | |
17836 | standard utilities: | |
17837 | ||
17838 | @smallexample | |
17839 | # Extract the dynamic symbols from the main binary, there is no need | |
5423b017 | 17840 | # to also have these in the normal symbol table. |
608e2dbb TT |
17841 | nm -D @var{binary} --format=posix --defined-only \ |
17842 | | awk '@{ print $1 @}' | sort > dynsyms | |
17843 | ||
5423b017 | 17844 | # Extract all the text (i.e. function) symbols from the debuginfo. |
1d236d23 JK |
17845 | # (Note that we actually also accept "D" symbols, for the benefit |
17846 | # of platforms like PowerPC64 that use function descriptors.) | |
608e2dbb | 17847 | nm @var{binary} --format=posix --defined-only \ |
1d236d23 | 17848 | | awk '@{ if ($2 == "T" || $2 == "t" || $2 == "D") print $1 @}' \ |
608e2dbb TT |
17849 | | sort > funcsyms |
17850 | ||
17851 | # Keep all the function symbols not already in the dynamic symbol | |
17852 | # table. | |
17853 | comm -13 dynsyms funcsyms > keep_symbols | |
17854 | ||
edf9f00c JK |
17855 | # Separate full debug info into debug binary. |
17856 | objcopy --only-keep-debug @var{binary} debug | |
17857 | ||
608e2dbb TT |
17858 | # Copy the full debuginfo, keeping only a minimal set of symbols and |
17859 | # removing some unnecessary sections. | |
17860 | objcopy -S --remove-section .gdb_index --remove-section .comment \ | |
edf9f00c JK |
17861 | --keep-symbols=keep_symbols debug mini_debuginfo |
17862 | ||
17863 | # Drop the full debug info from the original binary. | |
17864 | strip --strip-all -R .comment @var{binary} | |
608e2dbb TT |
17865 | |
17866 | # Inject the compressed data into the .gnu_debugdata section of the | |
17867 | # original binary. | |
17868 | xz mini_debuginfo | |
17869 | objcopy --add-section .gnu_debugdata=mini_debuginfo.xz @var{binary} | |
17870 | @end smallexample | |
5b5d99cf | 17871 | |
9291a0cd TT |
17872 | @node Index Files |
17873 | @section Index Files Speed Up @value{GDBN} | |
17874 | @cindex index files | |
17875 | @cindex @samp{.gdb_index} section | |
17876 | ||
17877 | When @value{GDBN} finds a symbol file, it scans the symbols in the | |
17878 | file in order to construct an internal symbol table. This lets most | |
17879 | @value{GDBN} operations work quickly---at the cost of a delay early | |
17880 | on. For large programs, this delay can be quite lengthy, so | |
17881 | @value{GDBN} provides a way to build an index, which speeds up | |
17882 | startup. | |
17883 | ||
17884 | The index is stored as a section in the symbol file. @value{GDBN} can | |
17885 | write the index to a file, then you can put it into the symbol file | |
17886 | using @command{objcopy}. | |
17887 | ||
17888 | To create an index file, use the @code{save gdb-index} command: | |
17889 | ||
17890 | @table @code | |
17891 | @item save gdb-index @var{directory} | |
17892 | @kindex save gdb-index | |
17893 | Create an index file for each symbol file currently known by | |
17894 | @value{GDBN}. Each file is named after its corresponding symbol file, | |
17895 | with @samp{.gdb-index} appended, and is written into the given | |
17896 | @var{directory}. | |
17897 | @end table | |
17898 | ||
17899 | Once you have created an index file you can merge it into your symbol | |
17900 | file, here named @file{symfile}, using @command{objcopy}: | |
17901 | ||
17902 | @smallexample | |
17903 | $ objcopy --add-section .gdb_index=symfile.gdb-index \ | |
17904 | --set-section-flags .gdb_index=readonly symfile symfile | |
17905 | @end smallexample | |
17906 | ||
e615022a DE |
17907 | @value{GDBN} will normally ignore older versions of @file{.gdb_index} |
17908 | sections that have been deprecated. Usually they are deprecated because | |
17909 | they are missing a new feature or have performance issues. | |
17910 | To tell @value{GDBN} to use a deprecated index section anyway | |
17911 | specify @code{set use-deprecated-index-sections on}. | |
17912 | The default is @code{off}. | |
17913 | This can speed up startup, but may result in some functionality being lost. | |
17914 | @xref{Index Section Format}. | |
17915 | ||
17916 | @emph{Warning:} Setting @code{use-deprecated-index-sections} to @code{on} | |
17917 | must be done before gdb reads the file. The following will not work: | |
17918 | ||
17919 | @smallexample | |
17920 | $ gdb -ex "set use-deprecated-index-sections on" <program> | |
17921 | @end smallexample | |
17922 | ||
17923 | Instead you must do, for example, | |
17924 | ||
17925 | @smallexample | |
17926 | $ gdb -iex "set use-deprecated-index-sections on" <program> | |
17927 | @end smallexample | |
17928 | ||
9291a0cd TT |
17929 | There are currently some limitation on indices. They only work when |
17930 | for DWARF debugging information, not stabs. And, they do not | |
17931 | currently work for programs using Ada. | |
17932 | ||
6d2ebf8b | 17933 | @node Symbol Errors |
79a6e687 | 17934 | @section Errors Reading Symbol Files |
c906108c SS |
17935 | |
17936 | While reading a symbol file, @value{GDBN} occasionally encounters problems, | |
17937 | such as symbol types it does not recognize, or known bugs in compiler | |
17938 | output. By default, @value{GDBN} does not notify you of such problems, since | |
17939 | they are relatively common and primarily of interest to people | |
17940 | debugging compilers. If you are interested in seeing information | |
17941 | about ill-constructed symbol tables, you can either ask @value{GDBN} to print | |
17942 | only one message about each such type of problem, no matter how many | |
17943 | times the problem occurs; or you can ask @value{GDBN} to print more messages, | |
17944 | to see how many times the problems occur, with the @code{set | |
79a6e687 BW |
17945 | complaints} command (@pxref{Messages/Warnings, ,Optional Warnings and |
17946 | Messages}). | |
c906108c SS |
17947 | |
17948 | The messages currently printed, and their meanings, include: | |
17949 | ||
17950 | @table @code | |
17951 | @item inner block not inside outer block in @var{symbol} | |
17952 | ||
17953 | The symbol information shows where symbol scopes begin and end | |
17954 | (such as at the start of a function or a block of statements). This | |
17955 | error indicates that an inner scope block is not fully contained | |
17956 | in its outer scope blocks. | |
17957 | ||
17958 | @value{GDBN} circumvents the problem by treating the inner block as if it had | |
17959 | the same scope as the outer block. In the error message, @var{symbol} | |
17960 | may be shown as ``@code{(don't know)}'' if the outer block is not a | |
17961 | function. | |
17962 | ||
17963 | @item block at @var{address} out of order | |
17964 | ||
17965 | The symbol information for symbol scope blocks should occur in | |
17966 | order of increasing addresses. This error indicates that it does not | |
17967 | do so. | |
17968 | ||
17969 | @value{GDBN} does not circumvent this problem, and has trouble | |
17970 | locating symbols in the source file whose symbols it is reading. (You | |
17971 | can often determine what source file is affected by specifying | |
79a6e687 BW |
17972 | @code{set verbose on}. @xref{Messages/Warnings, ,Optional Warnings and |
17973 | Messages}.) | |
c906108c SS |
17974 | |
17975 | @item bad block start address patched | |
17976 | ||
17977 | The symbol information for a symbol scope block has a start address | |
17978 | smaller than the address of the preceding source line. This is known | |
17979 | to occur in the SunOS 4.1.1 (and earlier) C compiler. | |
17980 | ||
17981 | @value{GDBN} circumvents the problem by treating the symbol scope block as | |
17982 | starting on the previous source line. | |
17983 | ||
17984 | @item bad string table offset in symbol @var{n} | |
17985 | ||
17986 | @cindex foo | |
17987 | Symbol number @var{n} contains a pointer into the string table which is | |
17988 | larger than the size of the string table. | |
17989 | ||
17990 | @value{GDBN} circumvents the problem by considering the symbol to have the | |
17991 | name @code{foo}, which may cause other problems if many symbols end up | |
17992 | with this name. | |
17993 | ||
17994 | @item unknown symbol type @code{0x@var{nn}} | |
17995 | ||
7a292a7a SS |
17996 | The symbol information contains new data types that @value{GDBN} does |
17997 | not yet know how to read. @code{0x@var{nn}} is the symbol type of the | |
d4f3574e | 17998 | uncomprehended information, in hexadecimal. |
c906108c | 17999 | |
7a292a7a SS |
18000 | @value{GDBN} circumvents the error by ignoring this symbol information. |
18001 | This usually allows you to debug your program, though certain symbols | |
c906108c | 18002 | are not accessible. If you encounter such a problem and feel like |
7a292a7a SS |
18003 | debugging it, you can debug @code{@value{GDBP}} with itself, breakpoint |
18004 | on @code{complain}, then go up to the function @code{read_dbx_symtab} | |
18005 | and examine @code{*bufp} to see the symbol. | |
c906108c SS |
18006 | |
18007 | @item stub type has NULL name | |
c906108c | 18008 | |
7a292a7a | 18009 | @value{GDBN} could not find the full definition for a struct or class. |
c906108c | 18010 | |
7a292a7a | 18011 | @item const/volatile indicator missing (ok if using g++ v1.x), got@dots{} |
b37052ae | 18012 | The symbol information for a C@t{++} member function is missing some |
7a292a7a SS |
18013 | information that recent versions of the compiler should have output for |
18014 | it. | |
c906108c SS |
18015 | |
18016 | @item info mismatch between compiler and debugger | |
18017 | ||
18018 | @value{GDBN} could not parse a type specification output by the compiler. | |
7a292a7a | 18019 | |
c906108c SS |
18020 | @end table |
18021 | ||
b14b1491 TT |
18022 | @node Data Files |
18023 | @section GDB Data Files | |
18024 | ||
18025 | @cindex prefix for data files | |
18026 | @value{GDBN} will sometimes read an auxiliary data file. These files | |
18027 | are kept in a directory known as the @dfn{data directory}. | |
18028 | ||
18029 | You can set the data directory's name, and view the name @value{GDBN} | |
18030 | is currently using. | |
18031 | ||
18032 | @table @code | |
18033 | @kindex set data-directory | |
18034 | @item set data-directory @var{directory} | |
18035 | Set the directory which @value{GDBN} searches for auxiliary data files | |
18036 | to @var{directory}. | |
18037 | ||
18038 | @kindex show data-directory | |
18039 | @item show data-directory | |
18040 | Show the directory @value{GDBN} searches for auxiliary data files. | |
18041 | @end table | |
18042 | ||
18043 | @cindex default data directory | |
18044 | @cindex @samp{--with-gdb-datadir} | |
18045 | You can set the default data directory by using the configure-time | |
18046 | @samp{--with-gdb-datadir} option. If the data directory is inside | |
18047 | @value{GDBN}'s configured binary prefix (set with @samp{--prefix} or | |
18048 | @samp{--exec-prefix}), then the default data directory will be updated | |
18049 | automatically if the installed @value{GDBN} is moved to a new | |
18050 | location. | |
18051 | ||
aae1c79a DE |
18052 | The data directory may also be specified with the |
18053 | @code{--data-directory} command line option. | |
18054 | @xref{Mode Options}. | |
18055 | ||
6d2ebf8b | 18056 | @node Targets |
c906108c | 18057 | @chapter Specifying a Debugging Target |
7a292a7a | 18058 | |
c906108c | 18059 | @cindex debugging target |
c906108c | 18060 | A @dfn{target} is the execution environment occupied by your program. |
53a5351d JM |
18061 | |
18062 | Often, @value{GDBN} runs in the same host environment as your program; | |
18063 | in that case, the debugging target is specified as a side effect when | |
18064 | you use the @code{file} or @code{core} commands. When you need more | |
c906108c SS |
18065 | flexibility---for example, running @value{GDBN} on a physically separate |
18066 | host, or controlling a standalone system over a serial port or a | |
53a5351d JM |
18067 | realtime system over a TCP/IP connection---you can use the @code{target} |
18068 | command to specify one of the target types configured for @value{GDBN} | |
79a6e687 | 18069 | (@pxref{Target Commands, ,Commands for Managing Targets}). |
c906108c | 18070 | |
a8f24a35 EZ |
18071 | @cindex target architecture |
18072 | It is possible to build @value{GDBN} for several different @dfn{target | |
18073 | architectures}. When @value{GDBN} is built like that, you can choose | |
18074 | one of the available architectures with the @kbd{set architecture} | |
18075 | command. | |
18076 | ||
18077 | @table @code | |
18078 | @kindex set architecture | |
18079 | @kindex show architecture | |
18080 | @item set architecture @var{arch} | |
18081 | This command sets the current target architecture to @var{arch}. The | |
18082 | value of @var{arch} can be @code{"auto"}, in addition to one of the | |
18083 | supported architectures. | |
18084 | ||
18085 | @item show architecture | |
18086 | Show the current target architecture. | |
9c16f35a EZ |
18087 | |
18088 | @item set processor | |
18089 | @itemx processor | |
18090 | @kindex set processor | |
18091 | @kindex show processor | |
18092 | These are alias commands for, respectively, @code{set architecture} | |
18093 | and @code{show architecture}. | |
a8f24a35 EZ |
18094 | @end table |
18095 | ||
c906108c SS |
18096 | @menu |
18097 | * Active Targets:: Active targets | |
18098 | * Target Commands:: Commands for managing targets | |
c906108c | 18099 | * Byte Order:: Choosing target byte order |
c906108c SS |
18100 | @end menu |
18101 | ||
6d2ebf8b | 18102 | @node Active Targets |
79a6e687 | 18103 | @section Active Targets |
7a292a7a | 18104 | |
c906108c SS |
18105 | @cindex stacking targets |
18106 | @cindex active targets | |
18107 | @cindex multiple targets | |
18108 | ||
8ea5bce5 | 18109 | There are multiple classes of targets such as: processes, executable files or |
c0edd9ed JK |
18110 | recording sessions. Core files belong to the process class, making core file |
18111 | and process mutually exclusive. Otherwise, @value{GDBN} can work concurrently | |
18112 | on multiple active targets, one in each class. This allows you to (for | |
18113 | example) start a process and inspect its activity, while still having access to | |
18114 | the executable file after the process finishes. Or if you start process | |
18115 | recording (@pxref{Reverse Execution}) and @code{reverse-step} there, you are | |
18116 | presented a virtual layer of the recording target, while the process target | |
18117 | remains stopped at the chronologically last point of the process execution. | |
18118 | ||
18119 | Use the @code{core-file} and @code{exec-file} commands to select a new core | |
18120 | file or executable target (@pxref{Files, ,Commands to Specify Files}). To | |
18121 | specify as a target a process that is already running, use the @code{attach} | |
18122 | command (@pxref{Attach, ,Debugging an Already-running Process}). | |
c906108c | 18123 | |
6d2ebf8b | 18124 | @node Target Commands |
79a6e687 | 18125 | @section Commands for Managing Targets |
c906108c SS |
18126 | |
18127 | @table @code | |
18128 | @item target @var{type} @var{parameters} | |
7a292a7a SS |
18129 | Connects the @value{GDBN} host environment to a target machine or |
18130 | process. A target is typically a protocol for talking to debugging | |
18131 | facilities. You use the argument @var{type} to specify the type or | |
18132 | protocol of the target machine. | |
c906108c SS |
18133 | |
18134 | Further @var{parameters} are interpreted by the target protocol, but | |
18135 | typically include things like device names or host names to connect | |
18136 | with, process numbers, and baud rates. | |
c906108c SS |
18137 | |
18138 | The @code{target} command does not repeat if you press @key{RET} again | |
18139 | after executing the command. | |
18140 | ||
18141 | @kindex help target | |
18142 | @item help target | |
18143 | Displays the names of all targets available. To display targets | |
18144 | currently selected, use either @code{info target} or @code{info files} | |
79a6e687 | 18145 | (@pxref{Files, ,Commands to Specify Files}). |
c906108c SS |
18146 | |
18147 | @item help target @var{name} | |
18148 | Describe a particular target, including any parameters necessary to | |
18149 | select it. | |
18150 | ||
18151 | @kindex set gnutarget | |
18152 | @item set gnutarget @var{args} | |
5d161b24 | 18153 | @value{GDBN} uses its own library BFD to read your files. @value{GDBN} |
c906108c | 18154 | knows whether it is reading an @dfn{executable}, |
5d161b24 DB |
18155 | a @dfn{core}, or a @dfn{.o} file; however, you can specify the file format |
18156 | with the @code{set gnutarget} command. Unlike most @code{target} commands, | |
c906108c SS |
18157 | with @code{gnutarget} the @code{target} refers to a program, not a machine. |
18158 | ||
d4f3574e | 18159 | @quotation |
c906108c SS |
18160 | @emph{Warning:} To specify a file format with @code{set gnutarget}, |
18161 | you must know the actual BFD name. | |
d4f3574e | 18162 | @end quotation |
c906108c | 18163 | |
d4f3574e | 18164 | @noindent |
79a6e687 | 18165 | @xref{Files, , Commands to Specify Files}. |
c906108c | 18166 | |
5d161b24 | 18167 | @kindex show gnutarget |
c906108c SS |
18168 | @item show gnutarget |
18169 | Use the @code{show gnutarget} command to display what file format | |
18170 | @code{gnutarget} is set to read. If you have not set @code{gnutarget}, | |
18171 | @value{GDBN} will determine the file format for each file automatically, | |
c4957902 | 18172 | and @code{show gnutarget} displays @samp{The current BFD target is "auto"}. |
c906108c SS |
18173 | @end table |
18174 | ||
4644b6e3 | 18175 | @cindex common targets |
c906108c SS |
18176 | Here are some common targets (available, or not, depending on the GDB |
18177 | configuration): | |
c906108c SS |
18178 | |
18179 | @table @code | |
4644b6e3 | 18180 | @kindex target |
c906108c | 18181 | @item target exec @var{program} |
4644b6e3 | 18182 | @cindex executable file target |
c906108c SS |
18183 | An executable file. @samp{target exec @var{program}} is the same as |
18184 | @samp{exec-file @var{program}}. | |
18185 | ||
c906108c | 18186 | @item target core @var{filename} |
4644b6e3 | 18187 | @cindex core dump file target |
c906108c SS |
18188 | A core dump file. @samp{target core @var{filename}} is the same as |
18189 | @samp{core-file @var{filename}}. | |
c906108c | 18190 | |
1a10341b | 18191 | @item target remote @var{medium} |
4644b6e3 | 18192 | @cindex remote target |
1a10341b JB |
18193 | A remote system connected to @value{GDBN} via a serial line or network |
18194 | connection. This command tells @value{GDBN} to use its own remote | |
18195 | protocol over @var{medium} for debugging. @xref{Remote Debugging}. | |
18196 | ||
18197 | For example, if you have a board connected to @file{/dev/ttya} on the | |
18198 | machine running @value{GDBN}, you could say: | |
18199 | ||
18200 | @smallexample | |
18201 | target remote /dev/ttya | |
18202 | @end smallexample | |
18203 | ||
18204 | @code{target remote} supports the @code{load} command. This is only | |
18205 | useful if you have some other way of getting the stub to the target | |
18206 | system, and you can put it somewhere in memory where it won't get | |
18207 | clobbered by the download. | |
c906108c | 18208 | |
ee8e71d4 | 18209 | @item target sim @r{[}@var{simargs}@r{]} @dots{} |
4644b6e3 | 18210 | @cindex built-in simulator target |
2df3850c | 18211 | Builtin CPU simulator. @value{GDBN} includes simulators for most architectures. |
104c1213 | 18212 | In general, |
474c8240 | 18213 | @smallexample |
104c1213 JM |
18214 | target sim |
18215 | load | |
18216 | run | |
474c8240 | 18217 | @end smallexample |
d4f3574e | 18218 | @noindent |
104c1213 | 18219 | works; however, you cannot assume that a specific memory map, device |
d4f3574e | 18220 | drivers, or even basic I/O is available, although some simulators do |
104c1213 JM |
18221 | provide these. For info about any processor-specific simulator details, |
18222 | see the appropriate section in @ref{Embedded Processors, ,Embedded | |
18223 | Processors}. | |
18224 | ||
6a3cb8e8 PA |
18225 | @item target native |
18226 | @cindex native target | |
18227 | Setup for local/native process debugging. Useful to make the | |
18228 | @code{run} command spawn native processes (likewise @code{attach}, | |
18229 | etc.@:) even when @code{set auto-connect-native-target} is @code{off} | |
18230 | (@pxref{set auto-connect-native-target}). | |
18231 | ||
c906108c SS |
18232 | @end table |
18233 | ||
5d161b24 | 18234 | Different targets are available on different configurations of @value{GDBN}; |
c906108c | 18235 | your configuration may have more or fewer targets. |
c906108c | 18236 | |
721c2651 EZ |
18237 | Many remote targets require you to download the executable's code once |
18238 | you've successfully established a connection. You may wish to control | |
3d00d119 DJ |
18239 | various aspects of this process. |
18240 | ||
18241 | @table @code | |
721c2651 EZ |
18242 | |
18243 | @item set hash | |
18244 | @kindex set hash@r{, for remote monitors} | |
18245 | @cindex hash mark while downloading | |
18246 | This command controls whether a hash mark @samp{#} is displayed while | |
18247 | downloading a file to the remote monitor. If on, a hash mark is | |
18248 | displayed after each S-record is successfully downloaded to the | |
18249 | monitor. | |
18250 | ||
18251 | @item show hash | |
18252 | @kindex show hash@r{, for remote monitors} | |
18253 | Show the current status of displaying the hash mark. | |
18254 | ||
18255 | @item set debug monitor | |
18256 | @kindex set debug monitor | |
18257 | @cindex display remote monitor communications | |
18258 | Enable or disable display of communications messages between | |
18259 | @value{GDBN} and the remote monitor. | |
18260 | ||
18261 | @item show debug monitor | |
18262 | @kindex show debug monitor | |
18263 | Show the current status of displaying communications between | |
18264 | @value{GDBN} and the remote monitor. | |
a8f24a35 | 18265 | @end table |
c906108c SS |
18266 | |
18267 | @table @code | |
18268 | ||
18269 | @kindex load @var{filename} | |
18270 | @item load @var{filename} | |
8edfe269 | 18271 | @anchor{load} |
c906108c SS |
18272 | Depending on what remote debugging facilities are configured into |
18273 | @value{GDBN}, the @code{load} command may be available. Where it exists, it | |
18274 | is meant to make @var{filename} (an executable) available for debugging | |
18275 | on the remote system---by downloading, or dynamic linking, for example. | |
18276 | @code{load} also records the @var{filename} symbol table in @value{GDBN}, like | |
18277 | the @code{add-symbol-file} command. | |
18278 | ||
18279 | If your @value{GDBN} does not have a @code{load} command, attempting to | |
18280 | execute it gets the error message ``@code{You can't do that when your | |
18281 | target is @dots{}}'' | |
c906108c SS |
18282 | |
18283 | The file is loaded at whatever address is specified in the executable. | |
18284 | For some object file formats, you can specify the load address when you | |
18285 | link the program; for other formats, like a.out, the object file format | |
18286 | specifies a fixed address. | |
18287 | @c FIXME! This would be a good place for an xref to the GNU linker doc. | |
18288 | ||
68437a39 DJ |
18289 | Depending on the remote side capabilities, @value{GDBN} may be able to |
18290 | load programs into flash memory. | |
18291 | ||
c906108c SS |
18292 | @code{load} does not repeat if you press @key{RET} again after using it. |
18293 | @end table | |
18294 | ||
6d2ebf8b | 18295 | @node Byte Order |
79a6e687 | 18296 | @section Choosing Target Byte Order |
7a292a7a | 18297 | |
c906108c SS |
18298 | @cindex choosing target byte order |
18299 | @cindex target byte order | |
c906108c | 18300 | |
eb17f351 | 18301 | Some types of processors, such as the @acronym{MIPS}, PowerPC, and Renesas SH, |
c906108c SS |
18302 | offer the ability to run either big-endian or little-endian byte |
18303 | orders. Usually the executable or symbol will include a bit to | |
18304 | designate the endian-ness, and you will not need to worry about | |
18305 | which to use. However, you may still find it useful to adjust | |
d4f3574e | 18306 | @value{GDBN}'s idea of processor endian-ness manually. |
c906108c SS |
18307 | |
18308 | @table @code | |
4644b6e3 | 18309 | @kindex set endian |
c906108c SS |
18310 | @item set endian big |
18311 | Instruct @value{GDBN} to assume the target is big-endian. | |
18312 | ||
c906108c SS |
18313 | @item set endian little |
18314 | Instruct @value{GDBN} to assume the target is little-endian. | |
18315 | ||
c906108c SS |
18316 | @item set endian auto |
18317 | Instruct @value{GDBN} to use the byte order associated with the | |
18318 | executable. | |
18319 | ||
18320 | @item show endian | |
18321 | Display @value{GDBN}'s current idea of the target byte order. | |
18322 | ||
18323 | @end table | |
18324 | ||
18325 | Note that these commands merely adjust interpretation of symbolic | |
18326 | data on the host, and that they have absolutely no effect on the | |
18327 | target system. | |
18328 | ||
ea35711c DJ |
18329 | |
18330 | @node Remote Debugging | |
18331 | @chapter Debugging Remote Programs | |
c906108c SS |
18332 | @cindex remote debugging |
18333 | ||
18334 | If you are trying to debug a program running on a machine that cannot run | |
5d161b24 DB |
18335 | @value{GDBN} in the usual way, it is often useful to use remote debugging. |
18336 | For example, you might use remote debugging on an operating system kernel, | |
c906108c SS |
18337 | or on a small system which does not have a general purpose operating system |
18338 | powerful enough to run a full-featured debugger. | |
18339 | ||
18340 | Some configurations of @value{GDBN} have special serial or TCP/IP interfaces | |
18341 | to make this work with particular debugging targets. In addition, | |
5d161b24 | 18342 | @value{GDBN} comes with a generic serial protocol (specific to @value{GDBN}, |
c906108c SS |
18343 | but not specific to any particular target system) which you can use if you |
18344 | write the remote stubs---the code that runs on the remote system to | |
18345 | communicate with @value{GDBN}. | |
18346 | ||
18347 | Other remote targets may be available in your | |
18348 | configuration of @value{GDBN}; use @code{help target} to list them. | |
c906108c | 18349 | |
6b2f586d | 18350 | @menu |
07f31aa6 | 18351 | * Connecting:: Connecting to a remote target |
a6b151f1 | 18352 | * File Transfer:: Sending files to a remote system |
6b2f586d | 18353 | * Server:: Using the gdbserver program |
79a6e687 BW |
18354 | * Remote Configuration:: Remote configuration |
18355 | * Remote Stub:: Implementing a remote stub | |
6b2f586d AC |
18356 | @end menu |
18357 | ||
07f31aa6 | 18358 | @node Connecting |
79a6e687 | 18359 | @section Connecting to a Remote Target |
07f31aa6 DJ |
18360 | |
18361 | On the @value{GDBN} host machine, you will need an unstripped copy of | |
d3e8051b | 18362 | your program, since @value{GDBN} needs symbol and debugging information. |
07f31aa6 DJ |
18363 | Start up @value{GDBN} as usual, using the name of the local copy of your |
18364 | program as the first argument. | |
18365 | ||
86941c27 JB |
18366 | @cindex @code{target remote} |
18367 | @value{GDBN} can communicate with the target over a serial line, or | |
18368 | over an @acronym{IP} network using @acronym{TCP} or @acronym{UDP}. In | |
18369 | each case, @value{GDBN} uses the same protocol for debugging your | |
18370 | program; only the medium carrying the debugging packets varies. The | |
18371 | @code{target remote} command establishes a connection to the target. | |
18372 | Its arguments indicate which medium to use: | |
18373 | ||
18374 | @table @code | |
18375 | ||
18376 | @item target remote @var{serial-device} | |
07f31aa6 | 18377 | @cindex serial line, @code{target remote} |
86941c27 JB |
18378 | Use @var{serial-device} to communicate with the target. For example, |
18379 | to use a serial line connected to the device named @file{/dev/ttyb}: | |
18380 | ||
18381 | @smallexample | |
18382 | target remote /dev/ttyb | |
18383 | @end smallexample | |
18384 | ||
07f31aa6 | 18385 | If you're using a serial line, you may want to give @value{GDBN} the |
2446f5ea | 18386 | @samp{--baud} option, or use the @code{set serial baud} command |
0d12017b | 18387 | (@pxref{Remote Configuration, set serial baud}) before the |
9c16f35a | 18388 | @code{target} command. |
07f31aa6 | 18389 | |
86941c27 JB |
18390 | @item target remote @code{@var{host}:@var{port}} |
18391 | @itemx target remote @code{tcp:@var{host}:@var{port}} | |
18392 | @cindex @acronym{TCP} port, @code{target remote} | |
18393 | Debug using a @acronym{TCP} connection to @var{port} on @var{host}. | |
18394 | The @var{host} may be either a host name or a numeric @acronym{IP} | |
18395 | address; @var{port} must be a decimal number. The @var{host} could be | |
18396 | the target machine itself, if it is directly connected to the net, or | |
18397 | it might be a terminal server which in turn has a serial line to the | |
18398 | target. | |
07f31aa6 | 18399 | |
86941c27 JB |
18400 | For example, to connect to port 2828 on a terminal server named |
18401 | @code{manyfarms}: | |
07f31aa6 DJ |
18402 | |
18403 | @smallexample | |
18404 | target remote manyfarms:2828 | |
18405 | @end smallexample | |
18406 | ||
86941c27 JB |
18407 | If your remote target is actually running on the same machine as your |
18408 | debugger session (e.g.@: a simulator for your target running on the | |
18409 | same host), you can omit the hostname. For example, to connect to | |
18410 | port 1234 on your local machine: | |
07f31aa6 DJ |
18411 | |
18412 | @smallexample | |
18413 | target remote :1234 | |
18414 | @end smallexample | |
18415 | @noindent | |
18416 | ||
18417 | Note that the colon is still required here. | |
18418 | ||
86941c27 JB |
18419 | @item target remote @code{udp:@var{host}:@var{port}} |
18420 | @cindex @acronym{UDP} port, @code{target remote} | |
18421 | Debug using @acronym{UDP} packets to @var{port} on @var{host}. For example, to | |
18422 | connect to @acronym{UDP} port 2828 on a terminal server named @code{manyfarms}: | |
07f31aa6 DJ |
18423 | |
18424 | @smallexample | |
18425 | target remote udp:manyfarms:2828 | |
18426 | @end smallexample | |
18427 | ||
86941c27 JB |
18428 | When using a @acronym{UDP} connection for remote debugging, you should |
18429 | keep in mind that the `U' stands for ``Unreliable''. @acronym{UDP} | |
18430 | can silently drop packets on busy or unreliable networks, which will | |
18431 | cause havoc with your debugging session. | |
18432 | ||
66b8c7f6 JB |
18433 | @item target remote | @var{command} |
18434 | @cindex pipe, @code{target remote} to | |
18435 | Run @var{command} in the background and communicate with it using a | |
18436 | pipe. The @var{command} is a shell command, to be parsed and expanded | |
18437 | by the system's command shell, @code{/bin/sh}; it should expect remote | |
18438 | protocol packets on its standard input, and send replies on its | |
18439 | standard output. You could use this to run a stand-alone simulator | |
18440 | that speaks the remote debugging protocol, to make net connections | |
18441 | using programs like @code{ssh}, or for other similar tricks. | |
18442 | ||
18443 | If @var{command} closes its standard output (perhaps by exiting), | |
18444 | @value{GDBN} will try to send it a @code{SIGTERM} signal. (If the | |
18445 | program has already exited, this will have no effect.) | |
18446 | ||
86941c27 | 18447 | @end table |
07f31aa6 | 18448 | |
86941c27 | 18449 | Once the connection has been established, you can use all the usual |
8edfe269 DJ |
18450 | commands to examine and change data. The remote program is already |
18451 | running; you can use @kbd{step} and @kbd{continue}, and you do not | |
18452 | need to use @kbd{run}. | |
07f31aa6 DJ |
18453 | |
18454 | @cindex interrupting remote programs | |
18455 | @cindex remote programs, interrupting | |
18456 | Whenever @value{GDBN} is waiting for the remote program, if you type the | |
c8aa23ab | 18457 | interrupt character (often @kbd{Ctrl-c}), @value{GDBN} attempts to stop the |
07f31aa6 DJ |
18458 | program. This may or may not succeed, depending in part on the hardware |
18459 | and the serial drivers the remote system uses. If you type the | |
18460 | interrupt character once again, @value{GDBN} displays this prompt: | |
18461 | ||
18462 | @smallexample | |
18463 | Interrupted while waiting for the program. | |
18464 | Give up (and stop debugging it)? (y or n) | |
18465 | @end smallexample | |
18466 | ||
18467 | If you type @kbd{y}, @value{GDBN} abandons the remote debugging session. | |
18468 | (If you decide you want to try again later, you can use @samp{target | |
18469 | remote} again to connect once more.) If you type @kbd{n}, @value{GDBN} | |
18470 | goes back to waiting. | |
18471 | ||
18472 | @table @code | |
18473 | @kindex detach (remote) | |
18474 | @item detach | |
18475 | When you have finished debugging the remote program, you can use the | |
18476 | @code{detach} command to release it from @value{GDBN} control. | |
18477 | Detaching from the target normally resumes its execution, but the results | |
18478 | will depend on your particular remote stub. After the @code{detach} | |
18479 | command, @value{GDBN} is free to connect to another target. | |
18480 | ||
18481 | @kindex disconnect | |
18482 | @item disconnect | |
18483 | The @code{disconnect} command behaves like @code{detach}, except that | |
18484 | the target is generally not resumed. It will wait for @value{GDBN} | |
18485 | (this instance or another one) to connect and continue debugging. After | |
18486 | the @code{disconnect} command, @value{GDBN} is again free to connect to | |
18487 | another target. | |
09d4efe1 EZ |
18488 | |
18489 | @cindex send command to remote monitor | |
fad38dfa EZ |
18490 | @cindex extend @value{GDBN} for remote targets |
18491 | @cindex add new commands for external monitor | |
09d4efe1 EZ |
18492 | @kindex monitor |
18493 | @item monitor @var{cmd} | |
fad38dfa EZ |
18494 | This command allows you to send arbitrary commands directly to the |
18495 | remote monitor. Since @value{GDBN} doesn't care about the commands it | |
18496 | sends like this, this command is the way to extend @value{GDBN}---you | |
18497 | can add new commands that only the external monitor will understand | |
18498 | and implement. | |
07f31aa6 DJ |
18499 | @end table |
18500 | ||
a6b151f1 DJ |
18501 | @node File Transfer |
18502 | @section Sending files to a remote system | |
18503 | @cindex remote target, file transfer | |
18504 | @cindex file transfer | |
18505 | @cindex sending files to remote systems | |
18506 | ||
18507 | Some remote targets offer the ability to transfer files over the same | |
18508 | connection used to communicate with @value{GDBN}. This is convenient | |
18509 | for targets accessible through other means, e.g.@: @sc{gnu}/Linux systems | |
18510 | running @code{gdbserver} over a network interface. For other targets, | |
18511 | e.g.@: embedded devices with only a single serial port, this may be | |
18512 | the only way to upload or download files. | |
18513 | ||
18514 | Not all remote targets support these commands. | |
18515 | ||
18516 | @table @code | |
18517 | @kindex remote put | |
18518 | @item remote put @var{hostfile} @var{targetfile} | |
18519 | Copy file @var{hostfile} from the host system (the machine running | |
18520 | @value{GDBN}) to @var{targetfile} on the target system. | |
18521 | ||
18522 | @kindex remote get | |
18523 | @item remote get @var{targetfile} @var{hostfile} | |
18524 | Copy file @var{targetfile} from the target system to @var{hostfile} | |
18525 | on the host system. | |
18526 | ||
18527 | @kindex remote delete | |
18528 | @item remote delete @var{targetfile} | |
18529 | Delete @var{targetfile} from the target system. | |
18530 | ||
18531 | @end table | |
18532 | ||
6f05cf9f | 18533 | @node Server |
79a6e687 | 18534 | @section Using the @code{gdbserver} Program |
6f05cf9f AC |
18535 | |
18536 | @kindex gdbserver | |
18537 | @cindex remote connection without stubs | |
18538 | @code{gdbserver} is a control program for Unix-like systems, which | |
18539 | allows you to connect your program with a remote @value{GDBN} via | |
18540 | @code{target remote}---but without linking in the usual debugging stub. | |
18541 | ||
18542 | @code{gdbserver} is not a complete replacement for the debugging stubs, | |
18543 | because it requires essentially the same operating-system facilities | |
18544 | that @value{GDBN} itself does. In fact, a system that can run | |
18545 | @code{gdbserver} to connect to a remote @value{GDBN} could also run | |
18546 | @value{GDBN} locally! @code{gdbserver} is sometimes useful nevertheless, | |
18547 | because it is a much smaller program than @value{GDBN} itself. It is | |
18548 | also easier to port than all of @value{GDBN}, so you may be able to get | |
18549 | started more quickly on a new system by using @code{gdbserver}. | |
18550 | Finally, if you develop code for real-time systems, you may find that | |
18551 | the tradeoffs involved in real-time operation make it more convenient to | |
18552 | do as much development work as possible on another system, for example | |
18553 | by cross-compiling. You can use @code{gdbserver} to make a similar | |
18554 | choice for debugging. | |
18555 | ||
18556 | @value{GDBN} and @code{gdbserver} communicate via either a serial line | |
18557 | or a TCP connection, using the standard @value{GDBN} remote serial | |
18558 | protocol. | |
18559 | ||
2d717e4f DJ |
18560 | @quotation |
18561 | @emph{Warning:} @code{gdbserver} does not have any built-in security. | |
18562 | Do not run @code{gdbserver} connected to any public network; a | |
18563 | @value{GDBN} connection to @code{gdbserver} provides access to the | |
18564 | target system with the same privileges as the user running | |
18565 | @code{gdbserver}. | |
18566 | @end quotation | |
18567 | ||
18568 | @subsection Running @code{gdbserver} | |
18569 | @cindex arguments, to @code{gdbserver} | |
d9b1a651 | 18570 | @cindex @code{gdbserver}, command-line arguments |
2d717e4f DJ |
18571 | |
18572 | Run @code{gdbserver} on the target system. You need a copy of the | |
18573 | program you want to debug, including any libraries it requires. | |
6f05cf9f AC |
18574 | @code{gdbserver} does not need your program's symbol table, so you can |
18575 | strip the program if necessary to save space. @value{GDBN} on the host | |
18576 | system does all the symbol handling. | |
18577 | ||
18578 | To use the server, you must tell it how to communicate with @value{GDBN}; | |
56460a61 | 18579 | the name of your program; and the arguments for your program. The usual |
6f05cf9f AC |
18580 | syntax is: |
18581 | ||
18582 | @smallexample | |
18583 | target> gdbserver @var{comm} @var{program} [ @var{args} @dots{} ] | |
18584 | @end smallexample | |
18585 | ||
e0f9f062 DE |
18586 | @var{comm} is either a device name (to use a serial line), or a TCP |
18587 | hostname and portnumber, or @code{-} or @code{stdio} to use | |
18588 | stdin/stdout of @code{gdbserver}. | |
18589 | For example, to debug Emacs with the argument | |
6f05cf9f AC |
18590 | @samp{foo.txt} and communicate with @value{GDBN} over the serial port |
18591 | @file{/dev/com1}: | |
18592 | ||
18593 | @smallexample | |
18594 | target> gdbserver /dev/com1 emacs foo.txt | |
18595 | @end smallexample | |
18596 | ||
18597 | @code{gdbserver} waits passively for the host @value{GDBN} to communicate | |
18598 | with it. | |
18599 | ||
18600 | To use a TCP connection instead of a serial line: | |
18601 | ||
18602 | @smallexample | |
18603 | target> gdbserver host:2345 emacs foo.txt | |
18604 | @end smallexample | |
18605 | ||
18606 | The only difference from the previous example is the first argument, | |
18607 | specifying that you are communicating with the host @value{GDBN} via | |
18608 | TCP. The @samp{host:2345} argument means that @code{gdbserver} is to | |
18609 | expect a TCP connection from machine @samp{host} to local TCP port 2345. | |
18610 | (Currently, the @samp{host} part is ignored.) You can choose any number | |
18611 | you want for the port number as long as it does not conflict with any | |
18612 | TCP ports already in use on the target system (for example, @code{23} is | |
18613 | reserved for @code{telnet}).@footnote{If you choose a port number that | |
18614 | conflicts with another service, @code{gdbserver} prints an error message | |
18615 | and exits.} You must use the same port number with the host @value{GDBN} | |
18616 | @code{target remote} command. | |
18617 | ||
e0f9f062 DE |
18618 | The @code{stdio} connection is useful when starting @code{gdbserver} |
18619 | with ssh: | |
18620 | ||
18621 | @smallexample | |
18622 | (gdb) target remote | ssh -T hostname gdbserver - hello | |
18623 | @end smallexample | |
18624 | ||
18625 | The @samp{-T} option to ssh is provided because we don't need a remote pty, | |
18626 | and we don't want escape-character handling. Ssh does this by default when | |
18627 | a command is provided, the flag is provided to make it explicit. | |
18628 | You could elide it if you want to. | |
18629 | ||
18630 | Programs started with stdio-connected gdbserver have @file{/dev/null} for | |
18631 | @code{stdin}, and @code{stdout},@code{stderr} are sent back to gdb for | |
18632 | display through a pipe connected to gdbserver. | |
18633 | Both @code{stdout} and @code{stderr} use the same pipe. | |
18634 | ||
2d717e4f | 18635 | @subsubsection Attaching to a Running Program |
d9b1a651 EZ |
18636 | @cindex attach to a program, @code{gdbserver} |
18637 | @cindex @option{--attach}, @code{gdbserver} option | |
2d717e4f | 18638 | |
56460a61 DJ |
18639 | On some targets, @code{gdbserver} can also attach to running programs. |
18640 | This is accomplished via the @code{--attach} argument. The syntax is: | |
18641 | ||
18642 | @smallexample | |
2d717e4f | 18643 | target> gdbserver --attach @var{comm} @var{pid} |
56460a61 DJ |
18644 | @end smallexample |
18645 | ||
18646 | @var{pid} is the process ID of a currently running process. It isn't necessary | |
18647 | to point @code{gdbserver} at a binary for the running process. | |
18648 | ||
b1fe9455 | 18649 | @pindex pidof |
b1fe9455 DJ |
18650 | You can debug processes by name instead of process ID if your target has the |
18651 | @code{pidof} utility: | |
18652 | ||
18653 | @smallexample | |
2d717e4f | 18654 | target> gdbserver --attach @var{comm} `pidof @var{program}` |
b1fe9455 DJ |
18655 | @end smallexample |
18656 | ||
f822c95b | 18657 | In case more than one copy of @var{program} is running, or @var{program} |
b1fe9455 DJ |
18658 | has multiple threads, most versions of @code{pidof} support the |
18659 | @code{-s} option to only return the first process ID. | |
18660 | ||
2d717e4f | 18661 | @subsubsection Multi-Process Mode for @code{gdbserver} |
d9b1a651 EZ |
18662 | @cindex @code{gdbserver}, multiple processes |
18663 | @cindex multiple processes with @code{gdbserver} | |
2d717e4f DJ |
18664 | |
18665 | When you connect to @code{gdbserver} using @code{target remote}, | |
18666 | @code{gdbserver} debugs the specified program only once. When the | |
18667 | program exits, or you detach from it, @value{GDBN} closes the connection | |
18668 | and @code{gdbserver} exits. | |
18669 | ||
6e6c6f50 | 18670 | If you connect using @kbd{target extended-remote}, @code{gdbserver} |
2d717e4f DJ |
18671 | enters multi-process mode. When the debugged program exits, or you |
18672 | detach from it, @value{GDBN} stays connected to @code{gdbserver} even | |
18673 | though no program is running. The @code{run} and @code{attach} | |
18674 | commands instruct @code{gdbserver} to run or attach to a new program. | |
18675 | The @code{run} command uses @code{set remote exec-file} (@pxref{set | |
18676 | remote exec-file}) to select the program to run. Command line | |
18677 | arguments are supported, except for wildcard expansion and I/O | |
18678 | redirection (@pxref{Arguments}). | |
18679 | ||
d9b1a651 | 18680 | @cindex @option{--multi}, @code{gdbserver} option |
2d717e4f DJ |
18681 | To start @code{gdbserver} without supplying an initial command to run |
18682 | or process ID to attach, use the @option{--multi} command line option. | |
6e6c6f50 | 18683 | Then you can connect using @kbd{target extended-remote} and start |
2d717e4f DJ |
18684 | the program you want to debug. |
18685 | ||
03f2bd59 JK |
18686 | In multi-process mode @code{gdbserver} does not automatically exit unless you |
18687 | use the option @option{--once}. You can terminate it by using | |
18688 | @code{monitor exit} (@pxref{Monitor Commands for gdbserver}). Note that the | |
18689 | conditions under which @code{gdbserver} terminates depend on how @value{GDBN} | |
18690 | connects to it (@kbd{target remote} or @kbd{target extended-remote}). The | |
18691 | @option{--multi} option to @code{gdbserver} has no influence on that. | |
18692 | ||
18693 | @subsubsection TCP port allocation lifecycle of @code{gdbserver} | |
18694 | ||
18695 | This section applies only when @code{gdbserver} is run to listen on a TCP port. | |
18696 | ||
18697 | @code{gdbserver} normally terminates after all of its debugged processes have | |
18698 | terminated in @kbd{target remote} mode. On the other hand, for @kbd{target | |
18699 | extended-remote}, @code{gdbserver} stays running even with no processes left. | |
18700 | @value{GDBN} normally terminates the spawned debugged process on its exit, | |
18701 | which normally also terminates @code{gdbserver} in the @kbd{target remote} | |
18702 | mode. Therefore, when the connection drops unexpectedly, and @value{GDBN} | |
18703 | cannot ask @code{gdbserver} to kill its debugged processes, @code{gdbserver} | |
18704 | stays running even in the @kbd{target remote} mode. | |
18705 | ||
18706 | When @code{gdbserver} stays running, @value{GDBN} can connect to it again later. | |
18707 | Such reconnecting is useful for features like @ref{disconnected tracing}. For | |
18708 | completeness, at most one @value{GDBN} can be connected at a time. | |
18709 | ||
18710 | @cindex @option{--once}, @code{gdbserver} option | |
18711 | By default, @code{gdbserver} keeps the listening TCP port open, so that | |
6e8c5661 | 18712 | subsequent connections are possible. However, if you start @code{gdbserver} |
03f2bd59 JK |
18713 | with the @option{--once} option, it will stop listening for any further |
18714 | connection attempts after connecting to the first @value{GDBN} session. This | |
18715 | means no further connections to @code{gdbserver} will be possible after the | |
18716 | first one. It also means @code{gdbserver} will terminate after the first | |
18717 | connection with remote @value{GDBN} has closed, even for unexpectedly closed | |
18718 | connections and even in the @kbd{target extended-remote} mode. The | |
18719 | @option{--once} option allows reusing the same port number for connecting to | |
18720 | multiple instances of @code{gdbserver} running on the same host, since each | |
18721 | instance closes its port after the first connection. | |
2d717e4f | 18722 | |
87ce2a04 | 18723 | @anchor{Other Command-Line Arguments for gdbserver} |
2d717e4f DJ |
18724 | @subsubsection Other Command-Line Arguments for @code{gdbserver} |
18725 | ||
d9b1a651 | 18726 | @cindex @option{--debug}, @code{gdbserver} option |
62709adf | 18727 | The @option{--debug} option tells @code{gdbserver} to display extra |
d9b1a651 EZ |
18728 | status information about the debugging process. |
18729 | @cindex @option{--remote-debug}, @code{gdbserver} option | |
18730 | The @option{--remote-debug} option tells @code{gdbserver} to display | |
62709adf PA |
18731 | remote protocol debug output. These options are intended for |
18732 | @code{gdbserver} development and for bug reports to the developers. | |
2d717e4f | 18733 | |
87ce2a04 DE |
18734 | @cindex @option{--debug-format}, @code{gdbserver} option |
18735 | The @option{--debug-format=option1[,option2,...]} option tells | |
18736 | @code{gdbserver} to include additional information in each output. | |
18737 | Possible options are: | |
18738 | ||
18739 | @table @code | |
18740 | @item none | |
18741 | Turn off all extra information in debugging output. | |
18742 | @item all | |
18743 | Turn on all extra information in debugging output. | |
18744 | @item timestamps | |
18745 | Include a timestamp in each line of debugging output. | |
18746 | @end table | |
18747 | ||
18748 | Options are processed in order. Thus, for example, if @option{none} | |
18749 | appears last then no additional information is added to debugging output. | |
18750 | ||
d9b1a651 | 18751 | @cindex @option{--wrapper}, @code{gdbserver} option |
ccd213ac DJ |
18752 | The @option{--wrapper} option specifies a wrapper to launch programs |
18753 | for debugging. The option should be followed by the name of the | |
18754 | wrapper, then any command-line arguments to pass to the wrapper, then | |
18755 | @kbd{--} indicating the end of the wrapper arguments. | |
18756 | ||
18757 | @code{gdbserver} runs the specified wrapper program with a combined | |
18758 | command line including the wrapper arguments, then the name of the | |
18759 | program to debug, then any arguments to the program. The wrapper | |
18760 | runs until it executes your program, and then @value{GDBN} gains control. | |
18761 | ||
18762 | You can use any program that eventually calls @code{execve} with | |
18763 | its arguments as a wrapper. Several standard Unix utilities do | |
18764 | this, e.g.@: @code{env} and @code{nohup}. Any Unix shell script ending | |
18765 | with @code{exec "$@@"} will also work. | |
18766 | ||
18767 | For example, you can use @code{env} to pass an environment variable to | |
18768 | the debugged program, without setting the variable in @code{gdbserver}'s | |
18769 | environment: | |
18770 | ||
18771 | @smallexample | |
18772 | $ gdbserver --wrapper env LD_PRELOAD=libtest.so -- :2222 ./testprog | |
18773 | @end smallexample | |
18774 | ||
2d717e4f DJ |
18775 | @subsection Connecting to @code{gdbserver} |
18776 | ||
18777 | Run @value{GDBN} on the host system. | |
18778 | ||
18779 | First make sure you have the necessary symbol files. Load symbols for | |
f822c95b DJ |
18780 | your application using the @code{file} command before you connect. Use |
18781 | @code{set sysroot} to locate target libraries (unless your @value{GDBN} | |
2d717e4f | 18782 | was compiled with the correct sysroot using @code{--with-sysroot}). |
f822c95b DJ |
18783 | |
18784 | The symbol file and target libraries must exactly match the executable | |
18785 | and libraries on the target, with one exception: the files on the host | |
18786 | system should not be stripped, even if the files on the target system | |
18787 | are. Mismatched or missing files will lead to confusing results | |
18788 | during debugging. On @sc{gnu}/Linux targets, mismatched or missing | |
18789 | files may also prevent @code{gdbserver} from debugging multi-threaded | |
18790 | programs. | |
18791 | ||
79a6e687 | 18792 | Connect to your target (@pxref{Connecting,,Connecting to a Remote Target}). |
6f05cf9f AC |
18793 | For TCP connections, you must start up @code{gdbserver} prior to using |
18794 | the @code{target remote} command. Otherwise you may get an error whose | |
18795 | text depends on the host system, but which usually looks something like | |
2d717e4f | 18796 | @samp{Connection refused}. Don't use the @code{load} |
397ca115 | 18797 | command in @value{GDBN} when using @code{gdbserver}, since the program is |
f822c95b | 18798 | already on the target. |
07f31aa6 | 18799 | |
79a6e687 | 18800 | @subsection Monitor Commands for @code{gdbserver} |
c74d0ad8 | 18801 | @cindex monitor commands, for @code{gdbserver} |
2d717e4f | 18802 | @anchor{Monitor Commands for gdbserver} |
c74d0ad8 DJ |
18803 | |
18804 | During a @value{GDBN} session using @code{gdbserver}, you can use the | |
18805 | @code{monitor} command to send special requests to @code{gdbserver}. | |
2d717e4f | 18806 | Here are the available commands. |
c74d0ad8 DJ |
18807 | |
18808 | @table @code | |
18809 | @item monitor help | |
18810 | List the available monitor commands. | |
18811 | ||
18812 | @item monitor set debug 0 | |
18813 | @itemx monitor set debug 1 | |
18814 | Disable or enable general debugging messages. | |
18815 | ||
18816 | @item monitor set remote-debug 0 | |
18817 | @itemx monitor set remote-debug 1 | |
18818 | Disable or enable specific debugging messages associated with the remote | |
18819 | protocol (@pxref{Remote Protocol}). | |
18820 | ||
87ce2a04 DE |
18821 | @item monitor set debug-format option1@r{[},option2,...@r{]} |
18822 | Specify additional text to add to debugging messages. | |
18823 | Possible options are: | |
18824 | ||
18825 | @table @code | |
18826 | @item none | |
18827 | Turn off all extra information in debugging output. | |
18828 | @item all | |
18829 | Turn on all extra information in debugging output. | |
18830 | @item timestamps | |
18831 | Include a timestamp in each line of debugging output. | |
18832 | @end table | |
18833 | ||
18834 | Options are processed in order. Thus, for example, if @option{none} | |
18835 | appears last then no additional information is added to debugging output. | |
18836 | ||
cdbfd419 PP |
18837 | @item monitor set libthread-db-search-path [PATH] |
18838 | @cindex gdbserver, search path for @code{libthread_db} | |
18839 | When this command is issued, @var{path} is a colon-separated list of | |
18840 | directories to search for @code{libthread_db} (@pxref{Threads,,set | |
18841 | libthread-db-search-path}). If you omit @var{path}, | |
84e578fb | 18842 | @samp{libthread-db-search-path} will be reset to its default value. |
cdbfd419 | 18843 | |
98a5dd13 DE |
18844 | The special entry @samp{$pdir} for @samp{libthread-db-search-path} is |
18845 | not supported in @code{gdbserver}. | |
18846 | ||
2d717e4f DJ |
18847 | @item monitor exit |
18848 | Tell gdbserver to exit immediately. This command should be followed by | |
18849 | @code{disconnect} to close the debugging session. @code{gdbserver} will | |
18850 | detach from any attached processes and kill any processes it created. | |
18851 | Use @code{monitor exit} to terminate @code{gdbserver} at the end | |
18852 | of a multi-process mode debug session. | |
18853 | ||
c74d0ad8 DJ |
18854 | @end table |
18855 | ||
fa593d66 PA |
18856 | @subsection Tracepoints support in @code{gdbserver} |
18857 | @cindex tracepoints support in @code{gdbserver} | |
18858 | ||
0fb4aa4b PA |
18859 | On some targets, @code{gdbserver} supports tracepoints, fast |
18860 | tracepoints and static tracepoints. | |
fa593d66 | 18861 | |
0fb4aa4b | 18862 | For fast or static tracepoints to work, a special library called the |
fa593d66 PA |
18863 | @dfn{in-process agent} (IPA), must be loaded in the inferior process. |
18864 | This library is built and distributed as an integral part of | |
0fb4aa4b PA |
18865 | @code{gdbserver}. In addition, support for static tracepoints |
18866 | requires building the in-process agent library with static tracepoints | |
18867 | support. At present, the UST (LTTng Userspace Tracer, | |
18868 | @url{http://lttng.org/ust}) tracing engine is supported. This support | |
18869 | is automatically available if UST development headers are found in the | |
18870 | standard include path when @code{gdbserver} is built, or if | |
18871 | @code{gdbserver} was explicitly configured using @option{--with-ust} | |
18872 | to point at such headers. You can explicitly disable the support | |
18873 | using @option{--with-ust=no}. | |
fa593d66 PA |
18874 | |
18875 | There are several ways to load the in-process agent in your program: | |
18876 | ||
18877 | @table @code | |
18878 | @item Specifying it as dependency at link time | |
18879 | ||
18880 | You can link your program dynamically with the in-process agent | |
18881 | library. On most systems, this is accomplished by adding | |
18882 | @code{-linproctrace} to the link command. | |
18883 | ||
18884 | @item Using the system's preloading mechanisms | |
18885 | ||
18886 | You can force loading the in-process agent at startup time by using | |
18887 | your system's support for preloading shared libraries. Many Unixes | |
18888 | support the concept of preloading user defined libraries. In most | |
18889 | cases, you do that by specifying @code{LD_PRELOAD=libinproctrace.so} | |
18890 | in the environment. See also the description of @code{gdbserver}'s | |
18891 | @option{--wrapper} command line option. | |
18892 | ||
18893 | @item Using @value{GDBN} to force loading the agent at run time | |
18894 | ||
18895 | On some systems, you can force the inferior to load a shared library, | |
18896 | by calling a dynamic loader function in the inferior that takes care | |
18897 | of dynamically looking up and loading a shared library. On most Unix | |
18898 | systems, the function is @code{dlopen}. You'll use the @code{call} | |
18899 | command for that. For example: | |
18900 | ||
18901 | @smallexample | |
18902 | (@value{GDBP}) call dlopen ("libinproctrace.so", ...) | |
18903 | @end smallexample | |
18904 | ||
18905 | Note that on most Unix systems, for the @code{dlopen} function to be | |
18906 | available, the program needs to be linked with @code{-ldl}. | |
18907 | @end table | |
18908 | ||
18909 | On systems that have a userspace dynamic loader, like most Unix | |
18910 | systems, when you connect to @code{gdbserver} using @code{target | |
18911 | remote}, you'll find that the program is stopped at the dynamic | |
18912 | loader's entry point, and no shared library has been loaded in the | |
18913 | program's address space yet, including the in-process agent. In that | |
0fb4aa4b PA |
18914 | case, before being able to use any of the fast or static tracepoints |
18915 | features, you need to let the loader run and load the shared | |
18916 | libraries. The simplest way to do that is to run the program to the | |
18917 | main procedure. E.g., if debugging a C or C@t{++} program, start | |
fa593d66 PA |
18918 | @code{gdbserver} like so: |
18919 | ||
18920 | @smallexample | |
18921 | $ gdbserver :9999 myprogram | |
18922 | @end smallexample | |
18923 | ||
18924 | Start GDB and connect to @code{gdbserver} like so, and run to main: | |
18925 | ||
18926 | @smallexample | |
18927 | $ gdb myprogram | |
18928 | (@value{GDBP}) target remote myhost:9999 | |
18929 | 0x00007f215893ba60 in ?? () from /lib64/ld-linux-x86-64.so.2 | |
18930 | (@value{GDBP}) b main | |
18931 | (@value{GDBP}) continue | |
18932 | @end smallexample | |
18933 | ||
18934 | The in-process tracing agent library should now be loaded into the | |
18935 | process; you can confirm it with the @code{info sharedlibrary} | |
18936 | command, which will list @file{libinproctrace.so} as loaded in the | |
0fb4aa4b PA |
18937 | process. You are now ready to install fast tracepoints, list static |
18938 | tracepoint markers, probe static tracepoints markers, and start | |
fa593d66 PA |
18939 | tracing. |
18940 | ||
79a6e687 BW |
18941 | @node Remote Configuration |
18942 | @section Remote Configuration | |
501eef12 | 18943 | |
9c16f35a EZ |
18944 | @kindex set remote |
18945 | @kindex show remote | |
18946 | This section documents the configuration options available when | |
18947 | debugging remote programs. For the options related to the File I/O | |
fc320d37 | 18948 | extensions of the remote protocol, see @ref{system, |
9c16f35a | 18949 | system-call-allowed}. |
501eef12 AC |
18950 | |
18951 | @table @code | |
9c16f35a | 18952 | @item set remoteaddresssize @var{bits} |
d3e8051b | 18953 | @cindex address size for remote targets |
9c16f35a EZ |
18954 | @cindex bits in remote address |
18955 | Set the maximum size of address in a memory packet to the specified | |
18956 | number of bits. @value{GDBN} will mask off the address bits above | |
18957 | that number, when it passes addresses to the remote target. The | |
18958 | default value is the number of bits in the target's address. | |
18959 | ||
18960 | @item show remoteaddresssize | |
18961 | Show the current value of remote address size in bits. | |
18962 | ||
0d12017b | 18963 | @item set serial baud @var{n} |
9c16f35a EZ |
18964 | @cindex baud rate for remote targets |
18965 | Set the baud rate for the remote serial I/O to @var{n} baud. The | |
18966 | value is used to set the speed of the serial port used for debugging | |
18967 | remote targets. | |
18968 | ||
0d12017b | 18969 | @item show serial baud |
9c16f35a EZ |
18970 | Show the current speed of the remote connection. |
18971 | ||
18972 | @item set remotebreak | |
18973 | @cindex interrupt remote programs | |
18974 | @cindex BREAK signal instead of Ctrl-C | |
9a6253be | 18975 | @anchor{set remotebreak} |
9c16f35a | 18976 | If set to on, @value{GDBN} sends a @code{BREAK} signal to the remote |
c8aa23ab | 18977 | when you type @kbd{Ctrl-c} to interrupt the program running |
9a7a1b36 | 18978 | on the remote. If set to off, @value{GDBN} sends the @samp{Ctrl-C} |
9c16f35a EZ |
18979 | character instead. The default is off, since most remote systems |
18980 | expect to see @samp{Ctrl-C} as the interrupt signal. | |
18981 | ||
18982 | @item show remotebreak | |
18983 | Show whether @value{GDBN} sends @code{BREAK} or @samp{Ctrl-C} to | |
18984 | interrupt the remote program. | |
18985 | ||
23776285 MR |
18986 | @item set remoteflow on |
18987 | @itemx set remoteflow off | |
18988 | @kindex set remoteflow | |
18989 | Enable or disable hardware flow control (@code{RTS}/@code{CTS}) | |
18990 | on the serial port used to communicate to the remote target. | |
18991 | ||
18992 | @item show remoteflow | |
18993 | @kindex show remoteflow | |
18994 | Show the current setting of hardware flow control. | |
18995 | ||
9c16f35a EZ |
18996 | @item set remotelogbase @var{base} |
18997 | Set the base (a.k.a.@: radix) of logging serial protocol | |
18998 | communications to @var{base}. Supported values of @var{base} are: | |
18999 | @code{ascii}, @code{octal}, and @code{hex}. The default is | |
19000 | @code{ascii}. | |
19001 | ||
19002 | @item show remotelogbase | |
19003 | Show the current setting of the radix for logging remote serial | |
19004 | protocol. | |
19005 | ||
19006 | @item set remotelogfile @var{file} | |
19007 | @cindex record serial communications on file | |
19008 | Record remote serial communications on the named @var{file}. The | |
19009 | default is not to record at all. | |
19010 | ||
19011 | @item show remotelogfile. | |
19012 | Show the current setting of the file name on which to record the | |
19013 | serial communications. | |
19014 | ||
19015 | @item set remotetimeout @var{num} | |
19016 | @cindex timeout for serial communications | |
19017 | @cindex remote timeout | |
19018 | Set the timeout limit to wait for the remote target to respond to | |
19019 | @var{num} seconds. The default is 2 seconds. | |
19020 | ||
19021 | @item show remotetimeout | |
19022 | Show the current number of seconds to wait for the remote target | |
19023 | responses. | |
19024 | ||
19025 | @cindex limit hardware breakpoints and watchpoints | |
19026 | @cindex remote target, limit break- and watchpoints | |
501eef12 AC |
19027 | @anchor{set remote hardware-watchpoint-limit} |
19028 | @anchor{set remote hardware-breakpoint-limit} | |
19029 | @item set remote hardware-watchpoint-limit @var{limit} | |
19030 | @itemx set remote hardware-breakpoint-limit @var{limit} | |
19031 | Restrict @value{GDBN} to using @var{limit} remote hardware breakpoint or | |
19032 | watchpoints. A limit of -1, the default, is treated as unlimited. | |
2d717e4f | 19033 | |
480a3f21 PW |
19034 | @cindex limit hardware watchpoints length |
19035 | @cindex remote target, limit watchpoints length | |
19036 | @anchor{set remote hardware-watchpoint-length-limit} | |
19037 | @item set remote hardware-watchpoint-length-limit @var{limit} | |
19038 | Restrict @value{GDBN} to using @var{limit} bytes for the maximum length of | |
19039 | a remote hardware watchpoint. A limit of -1, the default, is treated | |
19040 | as unlimited. | |
19041 | ||
19042 | @item show remote hardware-watchpoint-length-limit | |
19043 | Show the current limit (in bytes) of the maximum length of | |
19044 | a remote hardware watchpoint. | |
19045 | ||
2d717e4f DJ |
19046 | @item set remote exec-file @var{filename} |
19047 | @itemx show remote exec-file | |
19048 | @anchor{set remote exec-file} | |
19049 | @cindex executable file, for remote target | |
19050 | Select the file used for @code{run} with @code{target | |
19051 | extended-remote}. This should be set to a filename valid on the | |
19052 | target system. If it is not set, the target will use a default | |
19053 | filename (e.g.@: the last program run). | |
84603566 | 19054 | |
9a7071a8 JB |
19055 | @item set remote interrupt-sequence |
19056 | @cindex interrupt remote programs | |
19057 | @cindex select Ctrl-C, BREAK or BREAK-g | |
19058 | Allow the user to select one of @samp{Ctrl-C}, a @code{BREAK} or | |
19059 | @samp{BREAK-g} as the | |
19060 | sequence to the remote target in order to interrupt the execution. | |
19061 | @samp{Ctrl-C} is a default. Some system prefers @code{BREAK} which | |
19062 | is high level of serial line for some certain time. | |
19063 | Linux kernel prefers @samp{BREAK-g}, a.k.a Magic SysRq g. | |
19064 | It is @code{BREAK} signal followed by character @code{g}. | |
19065 | ||
19066 | @item show interrupt-sequence | |
19067 | Show which of @samp{Ctrl-C}, @code{BREAK} or @code{BREAK-g} | |
19068 | is sent by @value{GDBN} to interrupt the remote program. | |
19069 | @code{BREAK-g} is BREAK signal followed by @code{g} and | |
19070 | also known as Magic SysRq g. | |
19071 | ||
19072 | @item set remote interrupt-on-connect | |
19073 | @cindex send interrupt-sequence on start | |
19074 | Specify whether interrupt-sequence is sent to remote target when | |
19075 | @value{GDBN} connects to it. This is mostly needed when you debug | |
19076 | Linux kernel. Linux kernel expects @code{BREAK} followed by @code{g} | |
19077 | which is known as Magic SysRq g in order to connect @value{GDBN}. | |
19078 | ||
19079 | @item show interrupt-on-connect | |
19080 | Show whether interrupt-sequence is sent | |
19081 | to remote target when @value{GDBN} connects to it. | |
19082 | ||
84603566 SL |
19083 | @kindex set tcp |
19084 | @kindex show tcp | |
19085 | @item set tcp auto-retry on | |
19086 | @cindex auto-retry, for remote TCP target | |
19087 | Enable auto-retry for remote TCP connections. This is useful if the remote | |
19088 | debugging agent is launched in parallel with @value{GDBN}; there is a race | |
19089 | condition because the agent may not become ready to accept the connection | |
19090 | before @value{GDBN} attempts to connect. When auto-retry is | |
19091 | enabled, if the initial attempt to connect fails, @value{GDBN} reattempts | |
19092 | to establish the connection using the timeout specified by | |
19093 | @code{set tcp connect-timeout}. | |
19094 | ||
19095 | @item set tcp auto-retry off | |
19096 | Do not auto-retry failed TCP connections. | |
19097 | ||
19098 | @item show tcp auto-retry | |
19099 | Show the current auto-retry setting. | |
19100 | ||
19101 | @item set tcp connect-timeout @var{seconds} | |
f81d1120 | 19102 | @itemx set tcp connect-timeout unlimited |
84603566 SL |
19103 | @cindex connection timeout, for remote TCP target |
19104 | @cindex timeout, for remote target connection | |
19105 | Set the timeout for establishing a TCP connection to the remote target to | |
19106 | @var{seconds}. The timeout affects both polling to retry failed connections | |
19107 | (enabled by @code{set tcp auto-retry on}) and waiting for connections | |
19108 | that are merely slow to complete, and represents an approximate cumulative | |
f81d1120 PA |
19109 | value. If @var{seconds} is @code{unlimited}, there is no timeout and |
19110 | @value{GDBN} will keep attempting to establish a connection forever, | |
19111 | unless interrupted with @kbd{Ctrl-c}. The default is 15 seconds. | |
84603566 SL |
19112 | |
19113 | @item show tcp connect-timeout | |
19114 | Show the current connection timeout setting. | |
501eef12 AC |
19115 | @end table |
19116 | ||
427c3a89 DJ |
19117 | @cindex remote packets, enabling and disabling |
19118 | The @value{GDBN} remote protocol autodetects the packets supported by | |
19119 | your debugging stub. If you need to override the autodetection, you | |
19120 | can use these commands to enable or disable individual packets. Each | |
19121 | packet can be set to @samp{on} (the remote target supports this | |
19122 | packet), @samp{off} (the remote target does not support this packet), | |
19123 | or @samp{auto} (detect remote target support for this packet). They | |
19124 | all default to @samp{auto}. For more information about each packet, | |
19125 | see @ref{Remote Protocol}. | |
19126 | ||
19127 | During normal use, you should not have to use any of these commands. | |
19128 | If you do, that may be a bug in your remote debugging stub, or a bug | |
19129 | in @value{GDBN}. You may want to report the problem to the | |
19130 | @value{GDBN} developers. | |
19131 | ||
cfa9d6d9 DJ |
19132 | For each packet @var{name}, the command to enable or disable the |
19133 | packet is @code{set remote @var{name}-packet}. The available settings | |
19134 | are: | |
427c3a89 | 19135 | |
cfa9d6d9 | 19136 | @multitable @columnfractions 0.28 0.32 0.25 |
427c3a89 DJ |
19137 | @item Command Name |
19138 | @tab Remote Packet | |
19139 | @tab Related Features | |
19140 | ||
cfa9d6d9 | 19141 | @item @code{fetch-register} |
427c3a89 DJ |
19142 | @tab @code{p} |
19143 | @tab @code{info registers} | |
19144 | ||
cfa9d6d9 | 19145 | @item @code{set-register} |
427c3a89 DJ |
19146 | @tab @code{P} |
19147 | @tab @code{set} | |
19148 | ||
cfa9d6d9 | 19149 | @item @code{binary-download} |
427c3a89 DJ |
19150 | @tab @code{X} |
19151 | @tab @code{load}, @code{set} | |
19152 | ||
cfa9d6d9 | 19153 | @item @code{read-aux-vector} |
427c3a89 DJ |
19154 | @tab @code{qXfer:auxv:read} |
19155 | @tab @code{info auxv} | |
19156 | ||
cfa9d6d9 | 19157 | @item @code{symbol-lookup} |
427c3a89 DJ |
19158 | @tab @code{qSymbol} |
19159 | @tab Detecting multiple threads | |
19160 | ||
2d717e4f DJ |
19161 | @item @code{attach} |
19162 | @tab @code{vAttach} | |
19163 | @tab @code{attach} | |
19164 | ||
cfa9d6d9 | 19165 | @item @code{verbose-resume} |
427c3a89 DJ |
19166 | @tab @code{vCont} |
19167 | @tab Stepping or resuming multiple threads | |
19168 | ||
2d717e4f DJ |
19169 | @item @code{run} |
19170 | @tab @code{vRun} | |
19171 | @tab @code{run} | |
19172 | ||
cfa9d6d9 | 19173 | @item @code{software-breakpoint} |
427c3a89 DJ |
19174 | @tab @code{Z0} |
19175 | @tab @code{break} | |
19176 | ||
cfa9d6d9 | 19177 | @item @code{hardware-breakpoint} |
427c3a89 DJ |
19178 | @tab @code{Z1} |
19179 | @tab @code{hbreak} | |
19180 | ||
cfa9d6d9 | 19181 | @item @code{write-watchpoint} |
427c3a89 DJ |
19182 | @tab @code{Z2} |
19183 | @tab @code{watch} | |
19184 | ||
cfa9d6d9 | 19185 | @item @code{read-watchpoint} |
427c3a89 DJ |
19186 | @tab @code{Z3} |
19187 | @tab @code{rwatch} | |
19188 | ||
cfa9d6d9 | 19189 | @item @code{access-watchpoint} |
427c3a89 DJ |
19190 | @tab @code{Z4} |
19191 | @tab @code{awatch} | |
19192 | ||
cfa9d6d9 DJ |
19193 | @item @code{target-features} |
19194 | @tab @code{qXfer:features:read} | |
19195 | @tab @code{set architecture} | |
19196 | ||
19197 | @item @code{library-info} | |
19198 | @tab @code{qXfer:libraries:read} | |
19199 | @tab @code{info sharedlibrary} | |
19200 | ||
19201 | @item @code{memory-map} | |
19202 | @tab @code{qXfer:memory-map:read} | |
19203 | @tab @code{info mem} | |
19204 | ||
0fb4aa4b PA |
19205 | @item @code{read-sdata-object} |
19206 | @tab @code{qXfer:sdata:read} | |
19207 | @tab @code{print $_sdata} | |
19208 | ||
cfa9d6d9 DJ |
19209 | @item @code{read-spu-object} |
19210 | @tab @code{qXfer:spu:read} | |
19211 | @tab @code{info spu} | |
19212 | ||
19213 | @item @code{write-spu-object} | |
19214 | @tab @code{qXfer:spu:write} | |
19215 | @tab @code{info spu} | |
19216 | ||
4aa995e1 PA |
19217 | @item @code{read-siginfo-object} |
19218 | @tab @code{qXfer:siginfo:read} | |
19219 | @tab @code{print $_siginfo} | |
19220 | ||
19221 | @item @code{write-siginfo-object} | |
19222 | @tab @code{qXfer:siginfo:write} | |
19223 | @tab @code{set $_siginfo} | |
19224 | ||
dc146f7c VP |
19225 | @item @code{threads} |
19226 | @tab @code{qXfer:threads:read} | |
19227 | @tab @code{info threads} | |
19228 | ||
cfa9d6d9 | 19229 | @item @code{get-thread-local-@*storage-address} |
427c3a89 DJ |
19230 | @tab @code{qGetTLSAddr} |
19231 | @tab Displaying @code{__thread} variables | |
19232 | ||
711e434b PM |
19233 | @item @code{get-thread-information-block-address} |
19234 | @tab @code{qGetTIBAddr} | |
19235 | @tab Display MS-Windows Thread Information Block. | |
19236 | ||
08388c79 DE |
19237 | @item @code{search-memory} |
19238 | @tab @code{qSearch:memory} | |
19239 | @tab @code{find} | |
19240 | ||
427c3a89 DJ |
19241 | @item @code{supported-packets} |
19242 | @tab @code{qSupported} | |
19243 | @tab Remote communications parameters | |
19244 | ||
cfa9d6d9 | 19245 | @item @code{pass-signals} |
89be2091 DJ |
19246 | @tab @code{QPassSignals} |
19247 | @tab @code{handle @var{signal}} | |
19248 | ||
9b224c5e PA |
19249 | @item @code{program-signals} |
19250 | @tab @code{QProgramSignals} | |
19251 | @tab @code{handle @var{signal}} | |
19252 | ||
a6b151f1 DJ |
19253 | @item @code{hostio-close-packet} |
19254 | @tab @code{vFile:close} | |
19255 | @tab @code{remote get}, @code{remote put} | |
19256 | ||
19257 | @item @code{hostio-open-packet} | |
19258 | @tab @code{vFile:open} | |
19259 | @tab @code{remote get}, @code{remote put} | |
19260 | ||
19261 | @item @code{hostio-pread-packet} | |
19262 | @tab @code{vFile:pread} | |
19263 | @tab @code{remote get}, @code{remote put} | |
19264 | ||
19265 | @item @code{hostio-pwrite-packet} | |
19266 | @tab @code{vFile:pwrite} | |
19267 | @tab @code{remote get}, @code{remote put} | |
19268 | ||
19269 | @item @code{hostio-unlink-packet} | |
19270 | @tab @code{vFile:unlink} | |
19271 | @tab @code{remote delete} | |
a6f3e723 | 19272 | |
b9e7b9c3 UW |
19273 | @item @code{hostio-readlink-packet} |
19274 | @tab @code{vFile:readlink} | |
19275 | @tab Host I/O | |
19276 | ||
a6f3e723 SL |
19277 | @item @code{noack-packet} |
19278 | @tab @code{QStartNoAckMode} | |
19279 | @tab Packet acknowledgment | |
07e059b5 VP |
19280 | |
19281 | @item @code{osdata} | |
19282 | @tab @code{qXfer:osdata:read} | |
19283 | @tab @code{info os} | |
0b16c5cf PA |
19284 | |
19285 | @item @code{query-attached} | |
19286 | @tab @code{qAttached} | |
19287 | @tab Querying remote process attach state. | |
b3b9301e | 19288 | |
a46c1e42 PA |
19289 | @item @code{trace-buffer-size} |
19290 | @tab @code{QTBuffer:size} | |
19291 | @tab @code{set trace-buffer-size} | |
19292 | ||
bd3eecc3 PA |
19293 | @item @code{trace-status} |
19294 | @tab @code{qTStatus} | |
19295 | @tab @code{tstatus} | |
19296 | ||
b3b9301e PA |
19297 | @item @code{traceframe-info} |
19298 | @tab @code{qXfer:traceframe-info:read} | |
19299 | @tab Traceframe info | |
03583c20 | 19300 | |
1e4d1764 YQ |
19301 | @item @code{install-in-trace} |
19302 | @tab @code{InstallInTrace} | |
19303 | @tab Install tracepoint in tracing | |
19304 | ||
03583c20 UW |
19305 | @item @code{disable-randomization} |
19306 | @tab @code{QDisableRandomization} | |
19307 | @tab @code{set disable-randomization} | |
83364271 LM |
19308 | |
19309 | @item @code{conditional-breakpoints-packet} | |
19310 | @tab @code{Z0 and Z1} | |
19311 | @tab @code{Support for target-side breakpoint condition evaluation} | |
427c3a89 DJ |
19312 | @end multitable |
19313 | ||
79a6e687 BW |
19314 | @node Remote Stub |
19315 | @section Implementing a Remote Stub | |
7a292a7a | 19316 | |
8e04817f AC |
19317 | @cindex debugging stub, example |
19318 | @cindex remote stub, example | |
19319 | @cindex stub example, remote debugging | |
19320 | The stub files provided with @value{GDBN} implement the target side of the | |
19321 | communication protocol, and the @value{GDBN} side is implemented in the | |
19322 | @value{GDBN} source file @file{remote.c}. Normally, you can simply allow | |
19323 | these subroutines to communicate, and ignore the details. (If you're | |
19324 | implementing your own stub file, you can still ignore the details: start | |
19325 | with one of the existing stub files. @file{sparc-stub.c} is the best | |
19326 | organized, and therefore the easiest to read.) | |
19327 | ||
104c1213 JM |
19328 | @cindex remote serial debugging, overview |
19329 | To debug a program running on another machine (the debugging | |
19330 | @dfn{target} machine), you must first arrange for all the usual | |
19331 | prerequisites for the program to run by itself. For example, for a C | |
19332 | program, you need: | |
c906108c | 19333 | |
104c1213 JM |
19334 | @enumerate |
19335 | @item | |
19336 | A startup routine to set up the C runtime environment; these usually | |
19337 | have a name like @file{crt0}. The startup routine may be supplied by | |
19338 | your hardware supplier, or you may have to write your own. | |
96baa820 | 19339 | |
5d161b24 | 19340 | @item |
d4f3574e | 19341 | A C subroutine library to support your program's |
104c1213 | 19342 | subroutine calls, notably managing input and output. |
96baa820 | 19343 | |
104c1213 JM |
19344 | @item |
19345 | A way of getting your program to the other machine---for example, a | |
19346 | download program. These are often supplied by the hardware | |
19347 | manufacturer, but you may have to write your own from hardware | |
19348 | documentation. | |
19349 | @end enumerate | |
96baa820 | 19350 | |
104c1213 JM |
19351 | The next step is to arrange for your program to use a serial port to |
19352 | communicate with the machine where @value{GDBN} is running (the @dfn{host} | |
19353 | machine). In general terms, the scheme looks like this: | |
96baa820 | 19354 | |
104c1213 JM |
19355 | @table @emph |
19356 | @item On the host, | |
19357 | @value{GDBN} already understands how to use this protocol; when everything | |
19358 | else is set up, you can simply use the @samp{target remote} command | |
19359 | (@pxref{Targets,,Specifying a Debugging Target}). | |
19360 | ||
19361 | @item On the target, | |
19362 | you must link with your program a few special-purpose subroutines that | |
19363 | implement the @value{GDBN} remote serial protocol. The file containing these | |
19364 | subroutines is called a @dfn{debugging stub}. | |
19365 | ||
19366 | On certain remote targets, you can use an auxiliary program | |
19367 | @code{gdbserver} instead of linking a stub into your program. | |
79a6e687 | 19368 | @xref{Server,,Using the @code{gdbserver} Program}, for details. |
104c1213 | 19369 | @end table |
96baa820 | 19370 | |
104c1213 JM |
19371 | The debugging stub is specific to the architecture of the remote |
19372 | machine; for example, use @file{sparc-stub.c} to debug programs on | |
19373 | @sc{sparc} boards. | |
96baa820 | 19374 | |
104c1213 JM |
19375 | @cindex remote serial stub list |
19376 | These working remote stubs are distributed with @value{GDBN}: | |
96baa820 | 19377 | |
104c1213 JM |
19378 | @table @code |
19379 | ||
19380 | @item i386-stub.c | |
41afff9a | 19381 | @cindex @file{i386-stub.c} |
104c1213 JM |
19382 | @cindex Intel |
19383 | @cindex i386 | |
19384 | For Intel 386 and compatible architectures. | |
19385 | ||
19386 | @item m68k-stub.c | |
41afff9a | 19387 | @cindex @file{m68k-stub.c} |
104c1213 JM |
19388 | @cindex Motorola 680x0 |
19389 | @cindex m680x0 | |
19390 | For Motorola 680x0 architectures. | |
19391 | ||
19392 | @item sh-stub.c | |
41afff9a | 19393 | @cindex @file{sh-stub.c} |
172c2a43 | 19394 | @cindex Renesas |
104c1213 | 19395 | @cindex SH |
172c2a43 | 19396 | For Renesas SH architectures. |
104c1213 JM |
19397 | |
19398 | @item sparc-stub.c | |
41afff9a | 19399 | @cindex @file{sparc-stub.c} |
104c1213 JM |
19400 | @cindex Sparc |
19401 | For @sc{sparc} architectures. | |
19402 | ||
19403 | @item sparcl-stub.c | |
41afff9a | 19404 | @cindex @file{sparcl-stub.c} |
104c1213 JM |
19405 | @cindex Fujitsu |
19406 | @cindex SparcLite | |
19407 | For Fujitsu @sc{sparclite} architectures. | |
19408 | ||
19409 | @end table | |
19410 | ||
19411 | The @file{README} file in the @value{GDBN} distribution may list other | |
19412 | recently added stubs. | |
19413 | ||
19414 | @menu | |
19415 | * Stub Contents:: What the stub can do for you | |
19416 | * Bootstrapping:: What you must do for the stub | |
19417 | * Debug Session:: Putting it all together | |
104c1213 JM |
19418 | @end menu |
19419 | ||
6d2ebf8b | 19420 | @node Stub Contents |
79a6e687 | 19421 | @subsection What the Stub Can Do for You |
104c1213 JM |
19422 | |
19423 | @cindex remote serial stub | |
19424 | The debugging stub for your architecture supplies these three | |
19425 | subroutines: | |
19426 | ||
19427 | @table @code | |
19428 | @item set_debug_traps | |
4644b6e3 | 19429 | @findex set_debug_traps |
104c1213 JM |
19430 | @cindex remote serial stub, initialization |
19431 | This routine arranges for @code{handle_exception} to run when your | |
2fb860fc PA |
19432 | program stops. You must call this subroutine explicitly in your |
19433 | program's startup code. | |
104c1213 JM |
19434 | |
19435 | @item handle_exception | |
4644b6e3 | 19436 | @findex handle_exception |
104c1213 JM |
19437 | @cindex remote serial stub, main routine |
19438 | This is the central workhorse, but your program never calls it | |
19439 | explicitly---the setup code arranges for @code{handle_exception} to | |
19440 | run when a trap is triggered. | |
19441 | ||
19442 | @code{handle_exception} takes control when your program stops during | |
19443 | execution (for example, on a breakpoint), and mediates communications | |
19444 | with @value{GDBN} on the host machine. This is where the communications | |
19445 | protocol is implemented; @code{handle_exception} acts as the @value{GDBN} | |
d4f3574e | 19446 | representative on the target machine. It begins by sending summary |
104c1213 JM |
19447 | information on the state of your program, then continues to execute, |
19448 | retrieving and transmitting any information @value{GDBN} needs, until you | |
19449 | execute a @value{GDBN} command that makes your program resume; at that point, | |
19450 | @code{handle_exception} returns control to your own code on the target | |
5d161b24 | 19451 | machine. |
104c1213 JM |
19452 | |
19453 | @item breakpoint | |
19454 | @cindex @code{breakpoint} subroutine, remote | |
19455 | Use this auxiliary subroutine to make your program contain a | |
19456 | breakpoint. Depending on the particular situation, this may be the only | |
19457 | way for @value{GDBN} to get control. For instance, if your target | |
19458 | machine has some sort of interrupt button, you won't need to call this; | |
19459 | pressing the interrupt button transfers control to | |
19460 | @code{handle_exception}---in effect, to @value{GDBN}. On some machines, | |
19461 | simply receiving characters on the serial port may also trigger a trap; | |
19462 | again, in that situation, you don't need to call @code{breakpoint} from | |
19463 | your own program---simply running @samp{target remote} from the host | |
5d161b24 | 19464 | @value{GDBN} session gets control. |
104c1213 JM |
19465 | |
19466 | Call @code{breakpoint} if none of these is true, or if you simply want | |
19467 | to make certain your program stops at a predetermined point for the | |
19468 | start of your debugging session. | |
19469 | @end table | |
19470 | ||
6d2ebf8b | 19471 | @node Bootstrapping |
79a6e687 | 19472 | @subsection What You Must Do for the Stub |
104c1213 JM |
19473 | |
19474 | @cindex remote stub, support routines | |
19475 | The debugging stubs that come with @value{GDBN} are set up for a particular | |
19476 | chip architecture, but they have no information about the rest of your | |
19477 | debugging target machine. | |
19478 | ||
19479 | First of all you need to tell the stub how to communicate with the | |
19480 | serial port. | |
19481 | ||
19482 | @table @code | |
19483 | @item int getDebugChar() | |
4644b6e3 | 19484 | @findex getDebugChar |
104c1213 JM |
19485 | Write this subroutine to read a single character from the serial port. |
19486 | It may be identical to @code{getchar} for your target system; a | |
19487 | different name is used to allow you to distinguish the two if you wish. | |
19488 | ||
19489 | @item void putDebugChar(int) | |
4644b6e3 | 19490 | @findex putDebugChar |
104c1213 | 19491 | Write this subroutine to write a single character to the serial port. |
5d161b24 | 19492 | It may be identical to @code{putchar} for your target system; a |
104c1213 JM |
19493 | different name is used to allow you to distinguish the two if you wish. |
19494 | @end table | |
19495 | ||
19496 | @cindex control C, and remote debugging | |
19497 | @cindex interrupting remote targets | |
19498 | If you want @value{GDBN} to be able to stop your program while it is | |
19499 | running, you need to use an interrupt-driven serial driver, and arrange | |
19500 | for it to stop when it receives a @code{^C} (@samp{\003}, the control-C | |
19501 | character). That is the character which @value{GDBN} uses to tell the | |
19502 | remote system to stop. | |
19503 | ||
19504 | Getting the debugging target to return the proper status to @value{GDBN} | |
19505 | probably requires changes to the standard stub; one quick and dirty way | |
19506 | is to just execute a breakpoint instruction (the ``dirty'' part is that | |
19507 | @value{GDBN} reports a @code{SIGTRAP} instead of a @code{SIGINT}). | |
19508 | ||
19509 | Other routines you need to supply are: | |
19510 | ||
19511 | @table @code | |
19512 | @item void exceptionHandler (int @var{exception_number}, void *@var{exception_address}) | |
4644b6e3 | 19513 | @findex exceptionHandler |
104c1213 JM |
19514 | Write this function to install @var{exception_address} in the exception |
19515 | handling tables. You need to do this because the stub does not have any | |
19516 | way of knowing what the exception handling tables on your target system | |
19517 | are like (for example, the processor's table might be in @sc{rom}, | |
19518 | containing entries which point to a table in @sc{ram}). | |
697aa1b7 | 19519 | The @var{exception_number} specifies the exception which should be changed; |
104c1213 JM |
19520 | its meaning is architecture-dependent (for example, different numbers |
19521 | might represent divide by zero, misaligned access, etc). When this | |
19522 | exception occurs, control should be transferred directly to | |
19523 | @var{exception_address}, and the processor state (stack, registers, | |
19524 | and so on) should be just as it is when a processor exception occurs. So if | |
19525 | you want to use a jump instruction to reach @var{exception_address}, it | |
19526 | should be a simple jump, not a jump to subroutine. | |
19527 | ||
19528 | For the 386, @var{exception_address} should be installed as an interrupt | |
19529 | gate so that interrupts are masked while the handler runs. The gate | |
19530 | should be at privilege level 0 (the most privileged level). The | |
19531 | @sc{sparc} and 68k stubs are able to mask interrupts themselves without | |
19532 | help from @code{exceptionHandler}. | |
19533 | ||
19534 | @item void flush_i_cache() | |
4644b6e3 | 19535 | @findex flush_i_cache |
d4f3574e | 19536 | On @sc{sparc} and @sc{sparclite} only, write this subroutine to flush the |
104c1213 JM |
19537 | instruction cache, if any, on your target machine. If there is no |
19538 | instruction cache, this subroutine may be a no-op. | |
19539 | ||
19540 | On target machines that have instruction caches, @value{GDBN} requires this | |
19541 | function to make certain that the state of your program is stable. | |
19542 | @end table | |
19543 | ||
19544 | @noindent | |
19545 | You must also make sure this library routine is available: | |
19546 | ||
19547 | @table @code | |
19548 | @item void *memset(void *, int, int) | |
4644b6e3 | 19549 | @findex memset |
104c1213 JM |
19550 | This is the standard library function @code{memset} that sets an area of |
19551 | memory to a known value. If you have one of the free versions of | |
19552 | @code{libc.a}, @code{memset} can be found there; otherwise, you must | |
19553 | either obtain it from your hardware manufacturer, or write your own. | |
19554 | @end table | |
19555 | ||
19556 | If you do not use the GNU C compiler, you may need other standard | |
19557 | library subroutines as well; this varies from one stub to another, | |
19558 | but in general the stubs are likely to use any of the common library | |
e22ea452 | 19559 | subroutines which @code{@value{NGCC}} generates as inline code. |
104c1213 JM |
19560 | |
19561 | ||
6d2ebf8b | 19562 | @node Debug Session |
79a6e687 | 19563 | @subsection Putting it All Together |
104c1213 JM |
19564 | |
19565 | @cindex remote serial debugging summary | |
19566 | In summary, when your program is ready to debug, you must follow these | |
19567 | steps. | |
19568 | ||
19569 | @enumerate | |
19570 | @item | |
6d2ebf8b | 19571 | Make sure you have defined the supporting low-level routines |
79a6e687 | 19572 | (@pxref{Bootstrapping,,What You Must Do for the Stub}): |
104c1213 JM |
19573 | @display |
19574 | @code{getDebugChar}, @code{putDebugChar}, | |
19575 | @code{flush_i_cache}, @code{memset}, @code{exceptionHandler}. | |
19576 | @end display | |
19577 | ||
19578 | @item | |
2fb860fc PA |
19579 | Insert these lines in your program's startup code, before the main |
19580 | procedure is called: | |
104c1213 | 19581 | |
474c8240 | 19582 | @smallexample |
104c1213 JM |
19583 | set_debug_traps(); |
19584 | breakpoint(); | |
474c8240 | 19585 | @end smallexample |
104c1213 | 19586 | |
2fb860fc PA |
19587 | On some machines, when a breakpoint trap is raised, the hardware |
19588 | automatically makes the PC point to the instruction after the | |
19589 | breakpoint. If your machine doesn't do that, you may need to adjust | |
19590 | @code{handle_exception} to arrange for it to return to the instruction | |
19591 | after the breakpoint on this first invocation, so that your program | |
19592 | doesn't keep hitting the initial breakpoint instead of making | |
19593 | progress. | |
19594 | ||
104c1213 JM |
19595 | @item |
19596 | For the 680x0 stub only, you need to provide a variable called | |
19597 | @code{exceptionHook}. Normally you just use: | |
19598 | ||
474c8240 | 19599 | @smallexample |
104c1213 | 19600 | void (*exceptionHook)() = 0; |
474c8240 | 19601 | @end smallexample |
104c1213 | 19602 | |
d4f3574e | 19603 | @noindent |
104c1213 | 19604 | but if before calling @code{set_debug_traps}, you set it to point to a |
598ca718 | 19605 | function in your program, that function is called when |
104c1213 JM |
19606 | @code{@value{GDBN}} continues after stopping on a trap (for example, bus |
19607 | error). The function indicated by @code{exceptionHook} is called with | |
19608 | one parameter: an @code{int} which is the exception number. | |
19609 | ||
19610 | @item | |
19611 | Compile and link together: your program, the @value{GDBN} debugging stub for | |
19612 | your target architecture, and the supporting subroutines. | |
19613 | ||
19614 | @item | |
19615 | Make sure you have a serial connection between your target machine and | |
19616 | the @value{GDBN} host, and identify the serial port on the host. | |
19617 | ||
19618 | @item | |
19619 | @c The "remote" target now provides a `load' command, so we should | |
19620 | @c document that. FIXME. | |
19621 | Download your program to your target machine (or get it there by | |
19622 | whatever means the manufacturer provides), and start it. | |
19623 | ||
19624 | @item | |
07f31aa6 | 19625 | Start @value{GDBN} on the host, and connect to the target |
79a6e687 | 19626 | (@pxref{Connecting,,Connecting to a Remote Target}). |
9db8d71f | 19627 | |
104c1213 JM |
19628 | @end enumerate |
19629 | ||
8e04817f AC |
19630 | @node Configurations |
19631 | @chapter Configuration-Specific Information | |
104c1213 | 19632 | |
8e04817f AC |
19633 | While nearly all @value{GDBN} commands are available for all native and |
19634 | cross versions of the debugger, there are some exceptions. This chapter | |
19635 | describes things that are only available in certain configurations. | |
104c1213 | 19636 | |
8e04817f AC |
19637 | There are three major categories of configurations: native |
19638 | configurations, where the host and target are the same, embedded | |
19639 | operating system configurations, which are usually the same for several | |
19640 | different processor architectures, and bare embedded processors, which | |
19641 | are quite different from each other. | |
104c1213 | 19642 | |
8e04817f AC |
19643 | @menu |
19644 | * Native:: | |
19645 | * Embedded OS:: | |
19646 | * Embedded Processors:: | |
19647 | * Architectures:: | |
19648 | @end menu | |
104c1213 | 19649 | |
8e04817f AC |
19650 | @node Native |
19651 | @section Native | |
104c1213 | 19652 | |
8e04817f AC |
19653 | This section describes details specific to particular native |
19654 | configurations. | |
6cf7e474 | 19655 | |
8e04817f AC |
19656 | @menu |
19657 | * HP-UX:: HP-UX | |
7561d450 | 19658 | * BSD libkvm Interface:: Debugging BSD kernel memory images |
8e04817f AC |
19659 | * SVR4 Process Information:: SVR4 process information |
19660 | * DJGPP Native:: Features specific to the DJGPP port | |
78c47bea | 19661 | * Cygwin Native:: Features specific to the Cygwin port |
14d6dd68 | 19662 | * Hurd Native:: Features specific to @sc{gnu} Hurd |
a80b95ba | 19663 | * Darwin:: Features specific to Darwin |
8e04817f | 19664 | @end menu |
6cf7e474 | 19665 | |
8e04817f AC |
19666 | @node HP-UX |
19667 | @subsection HP-UX | |
104c1213 | 19668 | |
8e04817f AC |
19669 | On HP-UX systems, if you refer to a function or variable name that |
19670 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
19671 | name first, before it searches for a convenience variable. | |
104c1213 | 19672 | |
9c16f35a | 19673 | |
7561d450 MK |
19674 | @node BSD libkvm Interface |
19675 | @subsection BSD libkvm Interface | |
19676 | ||
19677 | @cindex libkvm | |
19678 | @cindex kernel memory image | |
19679 | @cindex kernel crash dump | |
19680 | ||
19681 | BSD-derived systems (FreeBSD/NetBSD/OpenBSD) have a kernel memory | |
19682 | interface that provides a uniform interface for accessing kernel virtual | |
19683 | memory images, including live systems and crash dumps. @value{GDBN} | |
19684 | uses this interface to allow you to debug live kernels and kernel crash | |
19685 | dumps on many native BSD configurations. This is implemented as a | |
19686 | special @code{kvm} debugging target. For debugging a live system, load | |
19687 | the currently running kernel into @value{GDBN} and connect to the | |
19688 | @code{kvm} target: | |
19689 | ||
19690 | @smallexample | |
19691 | (@value{GDBP}) @b{target kvm} | |
19692 | @end smallexample | |
19693 | ||
19694 | For debugging crash dumps, provide the file name of the crash dump as an | |
19695 | argument: | |
19696 | ||
19697 | @smallexample | |
19698 | (@value{GDBP}) @b{target kvm /var/crash/bsd.0} | |
19699 | @end smallexample | |
19700 | ||
19701 | Once connected to the @code{kvm} target, the following commands are | |
19702 | available: | |
19703 | ||
19704 | @table @code | |
19705 | @kindex kvm | |
19706 | @item kvm pcb | |
721c2651 | 19707 | Set current context from the @dfn{Process Control Block} (PCB) address. |
7561d450 MK |
19708 | |
19709 | @item kvm proc | |
19710 | Set current context from proc address. This command isn't available on | |
19711 | modern FreeBSD systems. | |
19712 | @end table | |
19713 | ||
8e04817f | 19714 | @node SVR4 Process Information |
79a6e687 | 19715 | @subsection SVR4 Process Information |
60bf7e09 EZ |
19716 | @cindex /proc |
19717 | @cindex examine process image | |
19718 | @cindex process info via @file{/proc} | |
104c1213 | 19719 | |
60bf7e09 EZ |
19720 | Many versions of SVR4 and compatible systems provide a facility called |
19721 | @samp{/proc} that can be used to examine the image of a running | |
451b7c33 TT |
19722 | process using file-system subroutines. |
19723 | ||
19724 | If @value{GDBN} is configured for an operating system with this | |
19725 | facility, the command @code{info proc} is available to report | |
19726 | information about the process running your program, or about any | |
19727 | process running on your system. This includes, as of this writing, | |
19728 | @sc{gnu}/Linux, OSF/1 (Digital Unix), Solaris, and Irix, but | |
19729 | not HP-UX, for example. | |
19730 | ||
19731 | This command may also work on core files that were created on a system | |
19732 | that has the @samp{/proc} facility. | |
104c1213 | 19733 | |
8e04817f AC |
19734 | @table @code |
19735 | @kindex info proc | |
60bf7e09 | 19736 | @cindex process ID |
8e04817f | 19737 | @item info proc |
60bf7e09 EZ |
19738 | @itemx info proc @var{process-id} |
19739 | Summarize available information about any running process. If a | |
19740 | process ID is specified by @var{process-id}, display information about | |
19741 | that process; otherwise display information about the program being | |
19742 | debugged. The summary includes the debugged process ID, the command | |
19743 | line used to invoke it, its current working directory, and its | |
19744 | executable file's absolute file name. | |
19745 | ||
19746 | On some systems, @var{process-id} can be of the form | |
19747 | @samp{[@var{pid}]/@var{tid}} which specifies a certain thread ID | |
19748 | within a process. If the optional @var{pid} part is missing, it means | |
19749 | a thread from the process being debugged (the leading @samp{/} still | |
19750 | needs to be present, or else @value{GDBN} will interpret the number as | |
19751 | a process ID rather than a thread ID). | |
6cf7e474 | 19752 | |
0c631110 TT |
19753 | @item info proc cmdline |
19754 | @cindex info proc cmdline | |
19755 | Show the original command line of the process. This command is | |
19756 | specific to @sc{gnu}/Linux. | |
19757 | ||
19758 | @item info proc cwd | |
19759 | @cindex info proc cwd | |
19760 | Show the current working directory of the process. This command is | |
19761 | specific to @sc{gnu}/Linux. | |
19762 | ||
19763 | @item info proc exe | |
19764 | @cindex info proc exe | |
19765 | Show the name of executable of the process. This command is specific | |
19766 | to @sc{gnu}/Linux. | |
19767 | ||
8e04817f | 19768 | @item info proc mappings |
60bf7e09 EZ |
19769 | @cindex memory address space mappings |
19770 | Report the memory address space ranges accessible in the program, with | |
19771 | information on whether the process has read, write, or execute access | |
19772 | rights to each range. On @sc{gnu}/Linux systems, each memory range | |
19773 | includes the object file which is mapped to that range, instead of the | |
19774 | memory access rights to that range. | |
19775 | ||
19776 | @item info proc stat | |
19777 | @itemx info proc status | |
19778 | @cindex process detailed status information | |
19779 | These subcommands are specific to @sc{gnu}/Linux systems. They show | |
19780 | the process-related information, including the user ID and group ID; | |
19781 | how many threads are there in the process; its virtual memory usage; | |
19782 | the signals that are pending, blocked, and ignored; its TTY; its | |
19783 | consumption of system and user time; its stack size; its @samp{nice} | |
2eecc4ab | 19784 | value; etc. For more information, see the @samp{proc} man page |
60bf7e09 EZ |
19785 | (type @kbd{man 5 proc} from your shell prompt). |
19786 | ||
19787 | @item info proc all | |
19788 | Show all the information about the process described under all of the | |
19789 | above @code{info proc} subcommands. | |
19790 | ||
8e04817f AC |
19791 | @ignore |
19792 | @comment These sub-options of 'info proc' were not included when | |
19793 | @comment procfs.c was re-written. Keep their descriptions around | |
19794 | @comment against the day when someone finds the time to put them back in. | |
19795 | @kindex info proc times | |
19796 | @item info proc times | |
19797 | Starting time, user CPU time, and system CPU time for your program and | |
19798 | its children. | |
6cf7e474 | 19799 | |
8e04817f AC |
19800 | @kindex info proc id |
19801 | @item info proc id | |
19802 | Report on the process IDs related to your program: its own process ID, | |
19803 | the ID of its parent, the process group ID, and the session ID. | |
8e04817f | 19804 | @end ignore |
721c2651 EZ |
19805 | |
19806 | @item set procfs-trace | |
19807 | @kindex set procfs-trace | |
19808 | @cindex @code{procfs} API calls | |
19809 | This command enables and disables tracing of @code{procfs} API calls. | |
19810 | ||
19811 | @item show procfs-trace | |
19812 | @kindex show procfs-trace | |
19813 | Show the current state of @code{procfs} API call tracing. | |
19814 | ||
19815 | @item set procfs-file @var{file} | |
19816 | @kindex set procfs-file | |
19817 | Tell @value{GDBN} to write @code{procfs} API trace to the named | |
19818 | @var{file}. @value{GDBN} appends the trace info to the previous | |
19819 | contents of the file. The default is to display the trace on the | |
19820 | standard output. | |
19821 | ||
19822 | @item show procfs-file | |
19823 | @kindex show procfs-file | |
19824 | Show the file to which @code{procfs} API trace is written. | |
19825 | ||
19826 | @item proc-trace-entry | |
19827 | @itemx proc-trace-exit | |
19828 | @itemx proc-untrace-entry | |
19829 | @itemx proc-untrace-exit | |
19830 | @kindex proc-trace-entry | |
19831 | @kindex proc-trace-exit | |
19832 | @kindex proc-untrace-entry | |
19833 | @kindex proc-untrace-exit | |
19834 | These commands enable and disable tracing of entries into and exits | |
19835 | from the @code{syscall} interface. | |
19836 | ||
19837 | @item info pidlist | |
19838 | @kindex info pidlist | |
19839 | @cindex process list, QNX Neutrino | |
19840 | For QNX Neutrino only, this command displays the list of all the | |
19841 | processes and all the threads within each process. | |
19842 | ||
19843 | @item info meminfo | |
19844 | @kindex info meminfo | |
19845 | @cindex mapinfo list, QNX Neutrino | |
19846 | For QNX Neutrino only, this command displays the list of all mapinfos. | |
8e04817f | 19847 | @end table |
104c1213 | 19848 | |
8e04817f AC |
19849 | @node DJGPP Native |
19850 | @subsection Features for Debugging @sc{djgpp} Programs | |
19851 | @cindex @sc{djgpp} debugging | |
19852 | @cindex native @sc{djgpp} debugging | |
19853 | @cindex MS-DOS-specific commands | |
104c1213 | 19854 | |
514c4d71 EZ |
19855 | @cindex DPMI |
19856 | @sc{djgpp} is a port of the @sc{gnu} development tools to MS-DOS and | |
8e04817f AC |
19857 | MS-Windows. @sc{djgpp} programs are 32-bit protected-mode programs |
19858 | that use the @dfn{DPMI} (DOS Protected-Mode Interface) API to run on | |
19859 | top of real-mode DOS systems and their emulations. | |
104c1213 | 19860 | |
8e04817f AC |
19861 | @value{GDBN} supports native debugging of @sc{djgpp} programs, and |
19862 | defines a few commands specific to the @sc{djgpp} port. This | |
19863 | subsection describes those commands. | |
104c1213 | 19864 | |
8e04817f AC |
19865 | @table @code |
19866 | @kindex info dos | |
19867 | @item info dos | |
19868 | This is a prefix of @sc{djgpp}-specific commands which print | |
19869 | information about the target system and important OS structures. | |
f1251bdd | 19870 | |
8e04817f AC |
19871 | @kindex sysinfo |
19872 | @cindex MS-DOS system info | |
19873 | @cindex free memory information (MS-DOS) | |
19874 | @item info dos sysinfo | |
19875 | This command displays assorted information about the underlying | |
19876 | platform: the CPU type and features, the OS version and flavor, the | |
19877 | DPMI version, and the available conventional and DPMI memory. | |
104c1213 | 19878 | |
8e04817f AC |
19879 | @cindex GDT |
19880 | @cindex LDT | |
19881 | @cindex IDT | |
19882 | @cindex segment descriptor tables | |
19883 | @cindex descriptor tables display | |
19884 | @item info dos gdt | |
19885 | @itemx info dos ldt | |
19886 | @itemx info dos idt | |
19887 | These 3 commands display entries from, respectively, Global, Local, | |
19888 | and Interrupt Descriptor Tables (GDT, LDT, and IDT). The descriptor | |
19889 | tables are data structures which store a descriptor for each segment | |
19890 | that is currently in use. The segment's selector is an index into a | |
19891 | descriptor table; the table entry for that index holds the | |
19892 | descriptor's base address and limit, and its attributes and access | |
19893 | rights. | |
104c1213 | 19894 | |
8e04817f AC |
19895 | A typical @sc{djgpp} program uses 3 segments: a code segment, a data |
19896 | segment (used for both data and the stack), and a DOS segment (which | |
19897 | allows access to DOS/BIOS data structures and absolute addresses in | |
19898 | conventional memory). However, the DPMI host will usually define | |
19899 | additional segments in order to support the DPMI environment. | |
d4f3574e | 19900 | |
8e04817f AC |
19901 | @cindex garbled pointers |
19902 | These commands allow to display entries from the descriptor tables. | |
19903 | Without an argument, all entries from the specified table are | |
19904 | displayed. An argument, which should be an integer expression, means | |
19905 | display a single entry whose index is given by the argument. For | |
19906 | example, here's a convenient way to display information about the | |
19907 | debugged program's data segment: | |
104c1213 | 19908 | |
8e04817f AC |
19909 | @smallexample |
19910 | @exdent @code{(@value{GDBP}) info dos ldt $ds} | |
19911 | @exdent @code{0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up)} | |
19912 | @end smallexample | |
104c1213 | 19913 | |
8e04817f AC |
19914 | @noindent |
19915 | This comes in handy when you want to see whether a pointer is outside | |
19916 | the data segment's limit (i.e.@: @dfn{garbled}). | |
104c1213 | 19917 | |
8e04817f AC |
19918 | @cindex page tables display (MS-DOS) |
19919 | @item info dos pde | |
19920 | @itemx info dos pte | |
19921 | These two commands display entries from, respectively, the Page | |
19922 | Directory and the Page Tables. Page Directories and Page Tables are | |
19923 | data structures which control how virtual memory addresses are mapped | |
19924 | into physical addresses. A Page Table includes an entry for every | |
19925 | page of memory that is mapped into the program's address space; there | |
19926 | may be several Page Tables, each one holding up to 4096 entries. A | |
19927 | Page Directory has up to 4096 entries, one each for every Page Table | |
19928 | that is currently in use. | |
104c1213 | 19929 | |
8e04817f AC |
19930 | Without an argument, @kbd{info dos pde} displays the entire Page |
19931 | Directory, and @kbd{info dos pte} displays all the entries in all of | |
19932 | the Page Tables. An argument, an integer expression, given to the | |
19933 | @kbd{info dos pde} command means display only that entry from the Page | |
19934 | Directory table. An argument given to the @kbd{info dos pte} command | |
19935 | means display entries from a single Page Table, the one pointed to by | |
19936 | the specified entry in the Page Directory. | |
104c1213 | 19937 | |
8e04817f AC |
19938 | @cindex direct memory access (DMA) on MS-DOS |
19939 | These commands are useful when your program uses @dfn{DMA} (Direct | |
19940 | Memory Access), which needs physical addresses to program the DMA | |
19941 | controller. | |
104c1213 | 19942 | |
8e04817f | 19943 | These commands are supported only with some DPMI servers. |
104c1213 | 19944 | |
8e04817f AC |
19945 | @cindex physical address from linear address |
19946 | @item info dos address-pte @var{addr} | |
19947 | This command displays the Page Table entry for a specified linear | |
514c4d71 EZ |
19948 | address. The argument @var{addr} is a linear address which should |
19949 | already have the appropriate segment's base address added to it, | |
19950 | because this command accepts addresses which may belong to @emph{any} | |
19951 | segment. For example, here's how to display the Page Table entry for | |
19952 | the page where a variable @code{i} is stored: | |
104c1213 | 19953 | |
b383017d | 19954 | @smallexample |
8e04817f AC |
19955 | @exdent @code{(@value{GDBP}) info dos address-pte __djgpp_base_address + (char *)&i} |
19956 | @exdent @code{Page Table entry for address 0x11a00d30:} | |
b383017d | 19957 | @exdent @code{Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30} |
8e04817f | 19958 | @end smallexample |
104c1213 | 19959 | |
8e04817f AC |
19960 | @noindent |
19961 | This says that @code{i} is stored at offset @code{0xd30} from the page | |
514c4d71 | 19962 | whose physical base address is @code{0x02698000}, and shows all the |
8e04817f | 19963 | attributes of that page. |
104c1213 | 19964 | |
8e04817f AC |
19965 | Note that you must cast the addresses of variables to a @code{char *}, |
19966 | since otherwise the value of @code{__djgpp_base_address}, the base | |
19967 | address of all variables and functions in a @sc{djgpp} program, will | |
19968 | be added using the rules of C pointer arithmetics: if @code{i} is | |
19969 | declared an @code{int}, @value{GDBN} will add 4 times the value of | |
19970 | @code{__djgpp_base_address} to the address of @code{i}. | |
104c1213 | 19971 | |
8e04817f AC |
19972 | Here's another example, it displays the Page Table entry for the |
19973 | transfer buffer: | |
104c1213 | 19974 | |
8e04817f AC |
19975 | @smallexample |
19976 | @exdent @code{(@value{GDBP}) info dos address-pte *((unsigned *)&_go32_info_block + 3)} | |
19977 | @exdent @code{Page Table entry for address 0x29110:} | |
19978 | @exdent @code{Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110} | |
19979 | @end smallexample | |
104c1213 | 19980 | |
8e04817f AC |
19981 | @noindent |
19982 | (The @code{+ 3} offset is because the transfer buffer's address is the | |
514c4d71 EZ |
19983 | 3rd member of the @code{_go32_info_block} structure.) The output |
19984 | clearly shows that this DPMI server maps the addresses in conventional | |
19985 | memory 1:1, i.e.@: the physical (@code{0x00029000} + @code{0x110}) and | |
19986 | linear (@code{0x29110}) addresses are identical. | |
104c1213 | 19987 | |
8e04817f AC |
19988 | This command is supported only with some DPMI servers. |
19989 | @end table | |
104c1213 | 19990 | |
c45da7e6 | 19991 | @cindex DOS serial data link, remote debugging |
a8f24a35 EZ |
19992 | In addition to native debugging, the DJGPP port supports remote |
19993 | debugging via a serial data link. The following commands are specific | |
19994 | to remote serial debugging in the DJGPP port of @value{GDBN}. | |
19995 | ||
19996 | @table @code | |
19997 | @kindex set com1base | |
19998 | @kindex set com1irq | |
19999 | @kindex set com2base | |
20000 | @kindex set com2irq | |
20001 | @kindex set com3base | |
20002 | @kindex set com3irq | |
20003 | @kindex set com4base | |
20004 | @kindex set com4irq | |
20005 | @item set com1base @var{addr} | |
20006 | This command sets the base I/O port address of the @file{COM1} serial | |
20007 | port. | |
20008 | ||
20009 | @item set com1irq @var{irq} | |
20010 | This command sets the @dfn{Interrupt Request} (@code{IRQ}) line to use | |
20011 | for the @file{COM1} serial port. | |
20012 | ||
20013 | There are similar commands @samp{set com2base}, @samp{set com3irq}, | |
20014 | etc.@: for setting the port address and the @code{IRQ} lines for the | |
20015 | other 3 COM ports. | |
20016 | ||
20017 | @kindex show com1base | |
20018 | @kindex show com1irq | |
20019 | @kindex show com2base | |
20020 | @kindex show com2irq | |
20021 | @kindex show com3base | |
20022 | @kindex show com3irq | |
20023 | @kindex show com4base | |
20024 | @kindex show com4irq | |
20025 | The related commands @samp{show com1base}, @samp{show com1irq} etc.@: | |
20026 | display the current settings of the base address and the @code{IRQ} | |
20027 | lines used by the COM ports. | |
c45da7e6 EZ |
20028 | |
20029 | @item info serial | |
20030 | @kindex info serial | |
20031 | @cindex DOS serial port status | |
20032 | This command prints the status of the 4 DOS serial ports. For each | |
20033 | port, it prints whether it's active or not, its I/O base address and | |
20034 | IRQ number, whether it uses a 16550-style FIFO, its baudrate, and the | |
20035 | counts of various errors encountered so far. | |
a8f24a35 EZ |
20036 | @end table |
20037 | ||
20038 | ||
78c47bea | 20039 | @node Cygwin Native |
79a6e687 | 20040 | @subsection Features for Debugging MS Windows PE Executables |
78c47bea PM |
20041 | @cindex MS Windows debugging |
20042 | @cindex native Cygwin debugging | |
20043 | @cindex Cygwin-specific commands | |
20044 | ||
be448670 | 20045 | @value{GDBN} supports native debugging of MS Windows programs, including |
cbb8f428 EZ |
20046 | DLLs with and without symbolic debugging information. |
20047 | ||
20048 | @cindex Ctrl-BREAK, MS-Windows | |
20049 | @cindex interrupt debuggee on MS-Windows | |
20050 | MS-Windows programs that call @code{SetConsoleMode} to switch off the | |
20051 | special meaning of the @samp{Ctrl-C} keystroke cannot be interrupted | |
20052 | by typing @kbd{C-c}. For this reason, @value{GDBN} on MS-Windows | |
20053 | supports @kbd{C-@key{BREAK}} as an alternative interrupt key | |
20054 | sequence, which can be used to interrupt the debuggee even if it | |
20055 | ignores @kbd{C-c}. | |
20056 | ||
20057 | There are various additional Cygwin-specific commands, described in | |
20058 | this section. Working with DLLs that have no debugging symbols is | |
20059 | described in @ref{Non-debug DLL Symbols}. | |
78c47bea PM |
20060 | |
20061 | @table @code | |
20062 | @kindex info w32 | |
20063 | @item info w32 | |
db2e3e2e | 20064 | This is a prefix of MS Windows-specific commands which print |
78c47bea PM |
20065 | information about the target system and important OS structures. |
20066 | ||
20067 | @item info w32 selector | |
20068 | This command displays information returned by | |
20069 | the Win32 API @code{GetThreadSelectorEntry} function. | |
20070 | It takes an optional argument that is evaluated to | |
20071 | a long value to give the information about this given selector. | |
20072 | Without argument, this command displays information | |
d3e8051b | 20073 | about the six segment registers. |
78c47bea | 20074 | |
711e434b PM |
20075 | @item info w32 thread-information-block |
20076 | This command displays thread specific information stored in the | |
20077 | Thread Information Block (readable on the X86 CPU family using @code{$fs} | |
20078 | selector for 32-bit programs and @code{$gs} for 64-bit programs). | |
20079 | ||
78c47bea PM |
20080 | @kindex info dll |
20081 | @item info dll | |
db2e3e2e | 20082 | This is a Cygwin-specific alias of @code{info shared}. |
78c47bea PM |
20083 | |
20084 | @kindex dll-symbols | |
20085 | @item dll-symbols | |
95060284 JB |
20086 | This command is deprecated and will be removed in future versions |
20087 | of @value{GDBN}. Use the @code{sharedlibrary} command instead. | |
20088 | ||
78c47bea PM |
20089 | This command loads symbols from a dll similarly to |
20090 | add-sym command but without the need to specify a base address. | |
20091 | ||
be90c084 | 20092 | @kindex set cygwin-exceptions |
e16b02ee EZ |
20093 | @cindex debugging the Cygwin DLL |
20094 | @cindex Cygwin DLL, debugging | |
be90c084 | 20095 | @item set cygwin-exceptions @var{mode} |
e16b02ee EZ |
20096 | If @var{mode} is @code{on}, @value{GDBN} will break on exceptions that |
20097 | happen inside the Cygwin DLL. If @var{mode} is @code{off}, | |
20098 | @value{GDBN} will delay recognition of exceptions, and may ignore some | |
20099 | exceptions which seem to be caused by internal Cygwin DLL | |
20100 | ``bookkeeping''. This option is meant primarily for debugging the | |
20101 | Cygwin DLL itself; the default value is @code{off} to avoid annoying | |
20102 | @value{GDBN} users with false @code{SIGSEGV} signals. | |
be90c084 CF |
20103 | |
20104 | @kindex show cygwin-exceptions | |
20105 | @item show cygwin-exceptions | |
e16b02ee EZ |
20106 | Displays whether @value{GDBN} will break on exceptions that happen |
20107 | inside the Cygwin DLL itself. | |
be90c084 | 20108 | |
b383017d | 20109 | @kindex set new-console |
78c47bea | 20110 | @item set new-console @var{mode} |
b383017d | 20111 | If @var{mode} is @code{on} the debuggee will |
78c47bea | 20112 | be started in a new console on next start. |
e03e5e7b | 20113 | If @var{mode} is @code{off}, the debuggee will |
78c47bea PM |
20114 | be started in the same console as the debugger. |
20115 | ||
20116 | @kindex show new-console | |
20117 | @item show new-console | |
20118 | Displays whether a new console is used | |
20119 | when the debuggee is started. | |
20120 | ||
20121 | @kindex set new-group | |
20122 | @item set new-group @var{mode} | |
20123 | This boolean value controls whether the debuggee should | |
20124 | start a new group or stay in the same group as the debugger. | |
20125 | This affects the way the Windows OS handles | |
c8aa23ab | 20126 | @samp{Ctrl-C}. |
78c47bea PM |
20127 | |
20128 | @kindex show new-group | |
20129 | @item show new-group | |
20130 | Displays current value of new-group boolean. | |
20131 | ||
20132 | @kindex set debugevents | |
20133 | @item set debugevents | |
219eec71 EZ |
20134 | This boolean value adds debug output concerning kernel events related |
20135 | to the debuggee seen by the debugger. This includes events that | |
20136 | signal thread and process creation and exit, DLL loading and | |
20137 | unloading, console interrupts, and debugging messages produced by the | |
20138 | Windows @code{OutputDebugString} API call. | |
78c47bea PM |
20139 | |
20140 | @kindex set debugexec | |
20141 | @item set debugexec | |
b383017d | 20142 | This boolean value adds debug output concerning execute events |
219eec71 | 20143 | (such as resume thread) seen by the debugger. |
78c47bea PM |
20144 | |
20145 | @kindex set debugexceptions | |
20146 | @item set debugexceptions | |
219eec71 EZ |
20147 | This boolean value adds debug output concerning exceptions in the |
20148 | debuggee seen by the debugger. | |
78c47bea PM |
20149 | |
20150 | @kindex set debugmemory | |
20151 | @item set debugmemory | |
219eec71 EZ |
20152 | This boolean value adds debug output concerning debuggee memory reads |
20153 | and writes by the debugger. | |
78c47bea PM |
20154 | |
20155 | @kindex set shell | |
20156 | @item set shell | |
20157 | This boolean values specifies whether the debuggee is called | |
20158 | via a shell or directly (default value is on). | |
20159 | ||
20160 | @kindex show shell | |
20161 | @item show shell | |
20162 | Displays if the debuggee will be started with a shell. | |
20163 | ||
20164 | @end table | |
20165 | ||
be448670 | 20166 | @menu |
79a6e687 | 20167 | * Non-debug DLL Symbols:: Support for DLLs without debugging symbols |
be448670 CF |
20168 | @end menu |
20169 | ||
79a6e687 BW |
20170 | @node Non-debug DLL Symbols |
20171 | @subsubsection Support for DLLs without Debugging Symbols | |
be448670 CF |
20172 | @cindex DLLs with no debugging symbols |
20173 | @cindex Minimal symbols and DLLs | |
20174 | ||
20175 | Very often on windows, some of the DLLs that your program relies on do | |
20176 | not include symbolic debugging information (for example, | |
db2e3e2e | 20177 | @file{kernel32.dll}). When @value{GDBN} doesn't recognize any debugging |
be448670 | 20178 | symbols in a DLL, it relies on the minimal amount of symbolic |
db2e3e2e | 20179 | information contained in the DLL's export table. This section |
be448670 CF |
20180 | describes working with such symbols, known internally to @value{GDBN} as |
20181 | ``minimal symbols''. | |
20182 | ||
20183 | Note that before the debugged program has started execution, no DLLs | |
db2e3e2e | 20184 | will have been loaded. The easiest way around this problem is simply to |
be448670 | 20185 | start the program --- either by setting a breakpoint or letting the |
95060284 | 20186 | program run once to completion. |
be448670 | 20187 | |
79a6e687 | 20188 | @subsubsection DLL Name Prefixes |
be448670 CF |
20189 | |
20190 | In keeping with the naming conventions used by the Microsoft debugging | |
20191 | tools, DLL export symbols are made available with a prefix based on the | |
20192 | DLL name, for instance @code{KERNEL32!CreateFileA}. The plain name is | |
20193 | also entered into the symbol table, so @code{CreateFileA} is often | |
99e008fe | 20194 | sufficient. In some cases there will be name clashes within a program |
be448670 CF |
20195 | (particularly if the executable itself includes full debugging symbols) |
20196 | necessitating the use of the fully qualified name when referring to the | |
99e008fe | 20197 | contents of the DLL. Use single-quotes around the name to avoid the |
be448670 CF |
20198 | exclamation mark (``!'') being interpreted as a language operator. |
20199 | ||
20200 | Note that the internal name of the DLL may be all upper-case, even | |
99e008fe | 20201 | though the file name of the DLL is lower-case, or vice-versa. Since |
be448670 CF |
20202 | symbols within @value{GDBN} are @emph{case-sensitive} this may cause |
20203 | some confusion. If in doubt, try the @code{info functions} and | |
0869d01b NR |
20204 | @code{info variables} commands or even @code{maint print msymbols} |
20205 | (@pxref{Symbols}). Here's an example: | |
be448670 CF |
20206 | |
20207 | @smallexample | |
f7dc1244 | 20208 | (@value{GDBP}) info function CreateFileA |
be448670 CF |
20209 | All functions matching regular expression "CreateFileA": |
20210 | ||
20211 | Non-debugging symbols: | |
20212 | 0x77e885f4 CreateFileA | |
20213 | 0x77e885f4 KERNEL32!CreateFileA | |
20214 | @end smallexample | |
20215 | ||
20216 | @smallexample | |
f7dc1244 | 20217 | (@value{GDBP}) info function ! |
be448670 CF |
20218 | All functions matching regular expression "!": |
20219 | ||
20220 | Non-debugging symbols: | |
20221 | 0x6100114c cygwin1!__assert | |
20222 | 0x61004034 cygwin1!_dll_crt0@@0 | |
20223 | 0x61004240 cygwin1!dll_crt0(per_process *) | |
20224 | [etc...] | |
20225 | @end smallexample | |
20226 | ||
79a6e687 | 20227 | @subsubsection Working with Minimal Symbols |
be448670 CF |
20228 | |
20229 | Symbols extracted from a DLL's export table do not contain very much | |
20230 | type information. All that @value{GDBN} can do is guess whether a symbol | |
20231 | refers to a function or variable depending on the linker section that | |
20232 | contains the symbol. Also note that the actual contents of the memory | |
20233 | contained in a DLL are not available unless the program is running. This | |
20234 | means that you cannot examine the contents of a variable or disassemble | |
20235 | a function within a DLL without a running program. | |
20236 | ||
20237 | Variables are generally treated as pointers and dereferenced | |
20238 | automatically. For this reason, it is often necessary to prefix a | |
20239 | variable name with the address-of operator (``&'') and provide explicit | |
20240 | type information in the command. Here's an example of the type of | |
20241 | problem: | |
20242 | ||
20243 | @smallexample | |
f7dc1244 | 20244 | (@value{GDBP}) print 'cygwin1!__argv' |
be448670 CF |
20245 | $1 = 268572168 |
20246 | @end smallexample | |
20247 | ||
20248 | @smallexample | |
f7dc1244 | 20249 | (@value{GDBP}) x 'cygwin1!__argv' |
be448670 CF |
20250 | 0x10021610: "\230y\"" |
20251 | @end smallexample | |
20252 | ||
20253 | And two possible solutions: | |
20254 | ||
20255 | @smallexample | |
f7dc1244 | 20256 | (@value{GDBP}) print ((char **)'cygwin1!__argv')[0] |
be448670 CF |
20257 | $2 = 0x22fd98 "/cygdrive/c/mydirectory/myprogram" |
20258 | @end smallexample | |
20259 | ||
20260 | @smallexample | |
f7dc1244 | 20261 | (@value{GDBP}) x/2x &'cygwin1!__argv' |
be448670 | 20262 | 0x610c0aa8 <cygwin1!__argv>: 0x10021608 0x00000000 |
f7dc1244 | 20263 | (@value{GDBP}) x/x 0x10021608 |
be448670 | 20264 | 0x10021608: 0x0022fd98 |
f7dc1244 | 20265 | (@value{GDBP}) x/s 0x0022fd98 |
be448670 CF |
20266 | 0x22fd98: "/cygdrive/c/mydirectory/myprogram" |
20267 | @end smallexample | |
20268 | ||
20269 | Setting a break point within a DLL is possible even before the program | |
20270 | starts execution. However, under these circumstances, @value{GDBN} can't | |
20271 | examine the initial instructions of the function in order to skip the | |
20272 | function's frame set-up code. You can work around this by using ``*&'' | |
20273 | to set the breakpoint at a raw memory address: | |
20274 | ||
20275 | @smallexample | |
f7dc1244 | 20276 | (@value{GDBP}) break *&'python22!PyOS_Readline' |
be448670 CF |
20277 | Breakpoint 1 at 0x1e04eff0 |
20278 | @end smallexample | |
20279 | ||
20280 | The author of these extensions is not entirely convinced that setting a | |
20281 | break point within a shared DLL like @file{kernel32.dll} is completely | |
20282 | safe. | |
20283 | ||
14d6dd68 | 20284 | @node Hurd Native |
79a6e687 | 20285 | @subsection Commands Specific to @sc{gnu} Hurd Systems |
14d6dd68 EZ |
20286 | @cindex @sc{gnu} Hurd debugging |
20287 | ||
20288 | This subsection describes @value{GDBN} commands specific to the | |
20289 | @sc{gnu} Hurd native debugging. | |
20290 | ||
20291 | @table @code | |
20292 | @item set signals | |
20293 | @itemx set sigs | |
20294 | @kindex set signals@r{, Hurd command} | |
20295 | @kindex set sigs@r{, Hurd command} | |
20296 | This command toggles the state of inferior signal interception by | |
20297 | @value{GDBN}. Mach exceptions, such as breakpoint traps, are not | |
20298 | affected by this command. @code{sigs} is a shorthand alias for | |
20299 | @code{signals}. | |
20300 | ||
20301 | @item show signals | |
20302 | @itemx show sigs | |
20303 | @kindex show signals@r{, Hurd command} | |
20304 | @kindex show sigs@r{, Hurd command} | |
20305 | Show the current state of intercepting inferior's signals. | |
20306 | ||
20307 | @item set signal-thread | |
20308 | @itemx set sigthread | |
20309 | @kindex set signal-thread | |
20310 | @kindex set sigthread | |
20311 | This command tells @value{GDBN} which thread is the @code{libc} signal | |
20312 | thread. That thread is run when a signal is delivered to a running | |
20313 | process. @code{set sigthread} is the shorthand alias of @code{set | |
20314 | signal-thread}. | |
20315 | ||
20316 | @item show signal-thread | |
20317 | @itemx show sigthread | |
20318 | @kindex show signal-thread | |
20319 | @kindex show sigthread | |
20320 | These two commands show which thread will run when the inferior is | |
20321 | delivered a signal. | |
20322 | ||
20323 | @item set stopped | |
20324 | @kindex set stopped@r{, Hurd command} | |
20325 | This commands tells @value{GDBN} that the inferior process is stopped, | |
20326 | as with the @code{SIGSTOP} signal. The stopped process can be | |
20327 | continued by delivering a signal to it. | |
20328 | ||
20329 | @item show stopped | |
20330 | @kindex show stopped@r{, Hurd command} | |
20331 | This command shows whether @value{GDBN} thinks the debuggee is | |
20332 | stopped. | |
20333 | ||
20334 | @item set exceptions | |
20335 | @kindex set exceptions@r{, Hurd command} | |
20336 | Use this command to turn off trapping of exceptions in the inferior. | |
20337 | When exception trapping is off, neither breakpoints nor | |
20338 | single-stepping will work. To restore the default, set exception | |
20339 | trapping on. | |
20340 | ||
20341 | @item show exceptions | |
20342 | @kindex show exceptions@r{, Hurd command} | |
20343 | Show the current state of trapping exceptions in the inferior. | |
20344 | ||
20345 | @item set task pause | |
20346 | @kindex set task@r{, Hurd commands} | |
20347 | @cindex task attributes (@sc{gnu} Hurd) | |
20348 | @cindex pause current task (@sc{gnu} Hurd) | |
20349 | This command toggles task suspension when @value{GDBN} has control. | |
20350 | Setting it to on takes effect immediately, and the task is suspended | |
20351 | whenever @value{GDBN} gets control. Setting it to off will take | |
20352 | effect the next time the inferior is continued. If this option is set | |
20353 | to off, you can use @code{set thread default pause on} or @code{set | |
20354 | thread pause on} (see below) to pause individual threads. | |
20355 | ||
20356 | @item show task pause | |
20357 | @kindex show task@r{, Hurd commands} | |
20358 | Show the current state of task suspension. | |
20359 | ||
20360 | @item set task detach-suspend-count | |
20361 | @cindex task suspend count | |
20362 | @cindex detach from task, @sc{gnu} Hurd | |
20363 | This command sets the suspend count the task will be left with when | |
20364 | @value{GDBN} detaches from it. | |
20365 | ||
20366 | @item show task detach-suspend-count | |
20367 | Show the suspend count the task will be left with when detaching. | |
20368 | ||
20369 | @item set task exception-port | |
20370 | @itemx set task excp | |
20371 | @cindex task exception port, @sc{gnu} Hurd | |
20372 | This command sets the task exception port to which @value{GDBN} will | |
20373 | forward exceptions. The argument should be the value of the @dfn{send | |
20374 | rights} of the task. @code{set task excp} is a shorthand alias. | |
20375 | ||
20376 | @item set noninvasive | |
20377 | @cindex noninvasive task options | |
20378 | This command switches @value{GDBN} to a mode that is the least | |
20379 | invasive as far as interfering with the inferior is concerned. This | |
20380 | is the same as using @code{set task pause}, @code{set exceptions}, and | |
20381 | @code{set signals} to values opposite to the defaults. | |
20382 | ||
20383 | @item info send-rights | |
20384 | @itemx info receive-rights | |
20385 | @itemx info port-rights | |
20386 | @itemx info port-sets | |
20387 | @itemx info dead-names | |
20388 | @itemx info ports | |
20389 | @itemx info psets | |
20390 | @cindex send rights, @sc{gnu} Hurd | |
20391 | @cindex receive rights, @sc{gnu} Hurd | |
20392 | @cindex port rights, @sc{gnu} Hurd | |
20393 | @cindex port sets, @sc{gnu} Hurd | |
20394 | @cindex dead names, @sc{gnu} Hurd | |
20395 | These commands display information about, respectively, send rights, | |
20396 | receive rights, port rights, port sets, and dead names of a task. | |
20397 | There are also shorthand aliases: @code{info ports} for @code{info | |
20398 | port-rights} and @code{info psets} for @code{info port-sets}. | |
20399 | ||
20400 | @item set thread pause | |
20401 | @kindex set thread@r{, Hurd command} | |
20402 | @cindex thread properties, @sc{gnu} Hurd | |
20403 | @cindex pause current thread (@sc{gnu} Hurd) | |
20404 | This command toggles current thread suspension when @value{GDBN} has | |
20405 | control. Setting it to on takes effect immediately, and the current | |
20406 | thread is suspended whenever @value{GDBN} gets control. Setting it to | |
20407 | off will take effect the next time the inferior is continued. | |
20408 | Normally, this command has no effect, since when @value{GDBN} has | |
20409 | control, the whole task is suspended. However, if you used @code{set | |
20410 | task pause off} (see above), this command comes in handy to suspend | |
20411 | only the current thread. | |
20412 | ||
20413 | @item show thread pause | |
20414 | @kindex show thread@r{, Hurd command} | |
20415 | This command shows the state of current thread suspension. | |
20416 | ||
20417 | @item set thread run | |
d3e8051b | 20418 | This command sets whether the current thread is allowed to run. |
14d6dd68 EZ |
20419 | |
20420 | @item show thread run | |
20421 | Show whether the current thread is allowed to run. | |
20422 | ||
20423 | @item set thread detach-suspend-count | |
20424 | @cindex thread suspend count, @sc{gnu} Hurd | |
20425 | @cindex detach from thread, @sc{gnu} Hurd | |
20426 | This command sets the suspend count @value{GDBN} will leave on a | |
20427 | thread when detaching. This number is relative to the suspend count | |
20428 | found by @value{GDBN} when it notices the thread; use @code{set thread | |
20429 | takeover-suspend-count} to force it to an absolute value. | |
20430 | ||
20431 | @item show thread detach-suspend-count | |
20432 | Show the suspend count @value{GDBN} will leave on the thread when | |
20433 | detaching. | |
20434 | ||
20435 | @item set thread exception-port | |
20436 | @itemx set thread excp | |
20437 | Set the thread exception port to which to forward exceptions. This | |
20438 | overrides the port set by @code{set task exception-port} (see above). | |
20439 | @code{set thread excp} is the shorthand alias. | |
20440 | ||
20441 | @item set thread takeover-suspend-count | |
20442 | Normally, @value{GDBN}'s thread suspend counts are relative to the | |
20443 | value @value{GDBN} finds when it notices each thread. This command | |
20444 | changes the suspend counts to be absolute instead. | |
20445 | ||
20446 | @item set thread default | |
20447 | @itemx show thread default | |
20448 | @cindex thread default settings, @sc{gnu} Hurd | |
20449 | Each of the above @code{set thread} commands has a @code{set thread | |
20450 | default} counterpart (e.g., @code{set thread default pause}, @code{set | |
20451 | thread default exception-port}, etc.). The @code{thread default} | |
20452 | variety of commands sets the default thread properties for all | |
20453 | threads; you can then change the properties of individual threads with | |
20454 | the non-default commands. | |
20455 | @end table | |
20456 | ||
a80b95ba TG |
20457 | @node Darwin |
20458 | @subsection Darwin | |
20459 | @cindex Darwin | |
20460 | ||
20461 | @value{GDBN} provides the following commands specific to the Darwin target: | |
20462 | ||
20463 | @table @code | |
20464 | @item set debug darwin @var{num} | |
20465 | @kindex set debug darwin | |
20466 | When set to a non zero value, enables debugging messages specific to | |
20467 | the Darwin support. Higher values produce more verbose output. | |
20468 | ||
20469 | @item show debug darwin | |
20470 | @kindex show debug darwin | |
20471 | Show the current state of Darwin messages. | |
20472 | ||
20473 | @item set debug mach-o @var{num} | |
20474 | @kindex set debug mach-o | |
20475 | When set to a non zero value, enables debugging messages while | |
20476 | @value{GDBN} is reading Darwin object files. (@dfn{Mach-O} is the | |
20477 | file format used on Darwin for object and executable files.) Higher | |
20478 | values produce more verbose output. This is a command to diagnose | |
20479 | problems internal to @value{GDBN} and should not be needed in normal | |
20480 | usage. | |
20481 | ||
20482 | @item show debug mach-o | |
20483 | @kindex show debug mach-o | |
20484 | Show the current state of Mach-O file messages. | |
20485 | ||
20486 | @item set mach-exceptions on | |
20487 | @itemx set mach-exceptions off | |
20488 | @kindex set mach-exceptions | |
20489 | On Darwin, faults are first reported as a Mach exception and are then | |
20490 | mapped to a Posix signal. Use this command to turn on trapping of | |
20491 | Mach exceptions in the inferior. This might be sometimes useful to | |
20492 | better understand the cause of a fault. The default is off. | |
20493 | ||
20494 | @item show mach-exceptions | |
20495 | @kindex show mach-exceptions | |
20496 | Show the current state of exceptions trapping. | |
20497 | @end table | |
20498 | ||
a64548ea | 20499 | |
8e04817f AC |
20500 | @node Embedded OS |
20501 | @section Embedded Operating Systems | |
104c1213 | 20502 | |
8e04817f AC |
20503 | This section describes configurations involving the debugging of |
20504 | embedded operating systems that are available for several different | |
20505 | architectures. | |
d4f3574e | 20506 | |
8e04817f AC |
20507 | @value{GDBN} includes the ability to debug programs running on |
20508 | various real-time operating systems. | |
104c1213 | 20509 | |
6d2ebf8b | 20510 | @node Embedded Processors |
104c1213 JM |
20511 | @section Embedded Processors |
20512 | ||
20513 | This section goes into details specific to particular embedded | |
20514 | configurations. | |
20515 | ||
c45da7e6 EZ |
20516 | @cindex send command to simulator |
20517 | Whenever a specific embedded processor has a simulator, @value{GDBN} | |
20518 | allows to send an arbitrary command to the simulator. | |
20519 | ||
20520 | @table @code | |
20521 | @item sim @var{command} | |
20522 | @kindex sim@r{, a command} | |
20523 | Send an arbitrary @var{command} string to the simulator. Consult the | |
20524 | documentation for the specific simulator in use for information about | |
20525 | acceptable commands. | |
20526 | @end table | |
20527 | ||
7d86b5d5 | 20528 | |
104c1213 | 20529 | @menu |
c45da7e6 | 20530 | * ARM:: ARM RDI |
172c2a43 | 20531 | * M32R/D:: Renesas M32R/D |
104c1213 | 20532 | * M68K:: Motorola M68K |
08be9d71 | 20533 | * MicroBlaze:: Xilinx MicroBlaze |
104c1213 | 20534 | * MIPS Embedded:: MIPS Embedded |
4acd40f3 | 20535 | * PowerPC Embedded:: PowerPC Embedded |
984359d2 | 20536 | * PA:: HP PA Embedded |
104c1213 JM |
20537 | * Sparclet:: Tsqware Sparclet |
20538 | * Sparclite:: Fujitsu Sparclite | |
104c1213 | 20539 | * Z8000:: Zilog Z8000 |
a64548ea EZ |
20540 | * AVR:: Atmel AVR |
20541 | * CRIS:: CRIS | |
20542 | * Super-H:: Renesas Super-H | |
104c1213 JM |
20543 | @end menu |
20544 | ||
6d2ebf8b | 20545 | @node ARM |
104c1213 | 20546 | @subsection ARM |
c45da7e6 | 20547 | @cindex ARM RDI |
104c1213 JM |
20548 | |
20549 | @table @code | |
8e04817f AC |
20550 | @kindex target rdi |
20551 | @item target rdi @var{dev} | |
20552 | ARM Angel monitor, via RDI library interface to ADP protocol. You may | |
20553 | use this target to communicate with both boards running the Angel | |
20554 | monitor, or with the EmbeddedICE JTAG debug device. | |
20555 | ||
20556 | @kindex target rdp | |
20557 | @item target rdp @var{dev} | |
20558 | ARM Demon monitor. | |
20559 | ||
20560 | @end table | |
20561 | ||
e2f4edfd EZ |
20562 | @value{GDBN} provides the following ARM-specific commands: |
20563 | ||
20564 | @table @code | |
20565 | @item set arm disassembler | |
20566 | @kindex set arm | |
20567 | This commands selects from a list of disassembly styles. The | |
20568 | @code{"std"} style is the standard style. | |
20569 | ||
20570 | @item show arm disassembler | |
20571 | @kindex show arm | |
20572 | Show the current disassembly style. | |
20573 | ||
20574 | @item set arm apcs32 | |
20575 | @cindex ARM 32-bit mode | |
20576 | This command toggles ARM operation mode between 32-bit and 26-bit. | |
20577 | ||
20578 | @item show arm apcs32 | |
20579 | Display the current usage of the ARM 32-bit mode. | |
20580 | ||
20581 | @item set arm fpu @var{fputype} | |
20582 | This command sets the ARM floating-point unit (FPU) type. The | |
20583 | argument @var{fputype} can be one of these: | |
20584 | ||
20585 | @table @code | |
20586 | @item auto | |
20587 | Determine the FPU type by querying the OS ABI. | |
20588 | @item softfpa | |
20589 | Software FPU, with mixed-endian doubles on little-endian ARM | |
20590 | processors. | |
20591 | @item fpa | |
20592 | GCC-compiled FPA co-processor. | |
20593 | @item softvfp | |
20594 | Software FPU with pure-endian doubles. | |
20595 | @item vfp | |
20596 | VFP co-processor. | |
20597 | @end table | |
20598 | ||
20599 | @item show arm fpu | |
20600 | Show the current type of the FPU. | |
20601 | ||
20602 | @item set arm abi | |
20603 | This command forces @value{GDBN} to use the specified ABI. | |
20604 | ||
20605 | @item show arm abi | |
20606 | Show the currently used ABI. | |
20607 | ||
0428b8f5 DJ |
20608 | @item set arm fallback-mode (arm|thumb|auto) |
20609 | @value{GDBN} uses the symbol table, when available, to determine | |
20610 | whether instructions are ARM or Thumb. This command controls | |
20611 | @value{GDBN}'s default behavior when the symbol table is not | |
20612 | available. The default is @samp{auto}, which causes @value{GDBN} to | |
20613 | use the current execution mode (from the @code{T} bit in the @code{CPSR} | |
20614 | register). | |
20615 | ||
20616 | @item show arm fallback-mode | |
20617 | Show the current fallback instruction mode. | |
20618 | ||
20619 | @item set arm force-mode (arm|thumb|auto) | |
20620 | This command overrides use of the symbol table to determine whether | |
20621 | instructions are ARM or Thumb. The default is @samp{auto}, which | |
20622 | causes @value{GDBN} to use the symbol table and then the setting | |
20623 | of @samp{set arm fallback-mode}. | |
20624 | ||
20625 | @item show arm force-mode | |
20626 | Show the current forced instruction mode. | |
20627 | ||
e2f4edfd EZ |
20628 | @item set debug arm |
20629 | Toggle whether to display ARM-specific debugging messages from the ARM | |
20630 | target support subsystem. | |
20631 | ||
20632 | @item show debug arm | |
20633 | Show whether ARM-specific debugging messages are enabled. | |
20634 | @end table | |
20635 | ||
c45da7e6 EZ |
20636 | The following commands are available when an ARM target is debugged |
20637 | using the RDI interface: | |
20638 | ||
20639 | @table @code | |
20640 | @item rdilogfile @r{[}@var{file}@r{]} | |
20641 | @kindex rdilogfile | |
20642 | @cindex ADP (Angel Debugger Protocol) logging | |
20643 | Set the filename for the ADP (Angel Debugger Protocol) packet log. | |
20644 | With an argument, sets the log file to the specified @var{file}. With | |
20645 | no argument, show the current log file name. The default log file is | |
20646 | @file{rdi.log}. | |
20647 | ||
20648 | @item rdilogenable @r{[}@var{arg}@r{]} | |
20649 | @kindex rdilogenable | |
20650 | Control logging of ADP packets. With an argument of 1 or @code{"yes"} | |
20651 | enables logging, with an argument 0 or @code{"no"} disables it. With | |
20652 | no arguments displays the current setting. When logging is enabled, | |
20653 | ADP packets exchanged between @value{GDBN} and the RDI target device | |
20654 | are logged to a file. | |
20655 | ||
20656 | @item set rdiromatzero | |
20657 | @kindex set rdiromatzero | |
20658 | @cindex ROM at zero address, RDI | |
20659 | Tell @value{GDBN} whether the target has ROM at address 0. If on, | |
20660 | vector catching is disabled, so that zero address can be used. If off | |
20661 | (the default), vector catching is enabled. For this command to take | |
20662 | effect, it needs to be invoked prior to the @code{target rdi} command. | |
20663 | ||
20664 | @item show rdiromatzero | |
20665 | @kindex show rdiromatzero | |
20666 | Show the current setting of ROM at zero address. | |
20667 | ||
20668 | @item set rdiheartbeat | |
20669 | @kindex set rdiheartbeat | |
20670 | @cindex RDI heartbeat | |
20671 | Enable or disable RDI heartbeat packets. It is not recommended to | |
20672 | turn on this option, since it confuses ARM and EPI JTAG interface, as | |
20673 | well as the Angel monitor. | |
20674 | ||
20675 | @item show rdiheartbeat | |
20676 | @kindex show rdiheartbeat | |
20677 | Show the setting of RDI heartbeat packets. | |
20678 | @end table | |
20679 | ||
ee8e71d4 EZ |
20680 | @table @code |
20681 | @item target sim @r{[}@var{simargs}@r{]} @dots{} | |
20682 | The @value{GDBN} ARM simulator accepts the following optional arguments. | |
20683 | ||
20684 | @table @code | |
20685 | @item --swi-support=@var{type} | |
697aa1b7 | 20686 | Tell the simulator which SWI interfaces to support. The argument |
ee8e71d4 EZ |
20687 | @var{type} may be a comma separated list of the following values. |
20688 | The default value is @code{all}. | |
20689 | ||
20690 | @table @code | |
20691 | @item none | |
20692 | @item demon | |
20693 | @item angel | |
20694 | @item redboot | |
20695 | @item all | |
20696 | @end table | |
20697 | @end table | |
20698 | @end table | |
e2f4edfd | 20699 | |
8e04817f | 20700 | @node M32R/D |
ba04e063 | 20701 | @subsection Renesas M32R/D and M32R/SDI |
8e04817f AC |
20702 | |
20703 | @table @code | |
8e04817f AC |
20704 | @kindex target m32r |
20705 | @item target m32r @var{dev} | |
172c2a43 | 20706 | Renesas M32R/D ROM monitor. |
8e04817f | 20707 | |
fb3e19c0 KI |
20708 | @kindex target m32rsdi |
20709 | @item target m32rsdi @var{dev} | |
20710 | Renesas M32R SDI server, connected via parallel port to the board. | |
721c2651 EZ |
20711 | @end table |
20712 | ||
20713 | The following @value{GDBN} commands are specific to the M32R monitor: | |
20714 | ||
20715 | @table @code | |
20716 | @item set download-path @var{path} | |
20717 | @kindex set download-path | |
20718 | @cindex find downloadable @sc{srec} files (M32R) | |
d3e8051b | 20719 | Set the default path for finding downloadable @sc{srec} files. |
721c2651 EZ |
20720 | |
20721 | @item show download-path | |
20722 | @kindex show download-path | |
20723 | Show the default path for downloadable @sc{srec} files. | |
fb3e19c0 | 20724 | |
721c2651 EZ |
20725 | @item set board-address @var{addr} |
20726 | @kindex set board-address | |
20727 | @cindex M32-EVA target board address | |
20728 | Set the IP address for the M32R-EVA target board. | |
20729 | ||
20730 | @item show board-address | |
20731 | @kindex show board-address | |
20732 | Show the current IP address of the target board. | |
20733 | ||
20734 | @item set server-address @var{addr} | |
20735 | @kindex set server-address | |
20736 | @cindex download server address (M32R) | |
20737 | Set the IP address for the download server, which is the @value{GDBN}'s | |
20738 | host machine. | |
20739 | ||
20740 | @item show server-address | |
20741 | @kindex show server-address | |
20742 | Display the IP address of the download server. | |
20743 | ||
20744 | @item upload @r{[}@var{file}@r{]} | |
20745 | @kindex upload@r{, M32R} | |
20746 | Upload the specified @sc{srec} @var{file} via the monitor's Ethernet | |
20747 | upload capability. If no @var{file} argument is given, the current | |
20748 | executable file is uploaded. | |
20749 | ||
20750 | @item tload @r{[}@var{file}@r{]} | |
20751 | @kindex tload@r{, M32R} | |
20752 | Test the @code{upload} command. | |
8e04817f AC |
20753 | @end table |
20754 | ||
ba04e063 EZ |
20755 | The following commands are available for M32R/SDI: |
20756 | ||
20757 | @table @code | |
20758 | @item sdireset | |
20759 | @kindex sdireset | |
20760 | @cindex reset SDI connection, M32R | |
20761 | This command resets the SDI connection. | |
20762 | ||
20763 | @item sdistatus | |
20764 | @kindex sdistatus | |
20765 | This command shows the SDI connection status. | |
20766 | ||
20767 | @item debug_chaos | |
20768 | @kindex debug_chaos | |
20769 | @cindex M32R/Chaos debugging | |
20770 | Instructs the remote that M32R/Chaos debugging is to be used. | |
20771 | ||
20772 | @item use_debug_dma | |
20773 | @kindex use_debug_dma | |
20774 | Instructs the remote to use the DEBUG_DMA method of accessing memory. | |
20775 | ||
20776 | @item use_mon_code | |
20777 | @kindex use_mon_code | |
20778 | Instructs the remote to use the MON_CODE method of accessing memory. | |
20779 | ||
20780 | @item use_ib_break | |
20781 | @kindex use_ib_break | |
20782 | Instructs the remote to set breakpoints by IB break. | |
20783 | ||
20784 | @item use_dbt_break | |
20785 | @kindex use_dbt_break | |
20786 | Instructs the remote to set breakpoints by DBT. | |
20787 | @end table | |
20788 | ||
8e04817f AC |
20789 | @node M68K |
20790 | @subsection M68k | |
20791 | ||
7ce59000 DJ |
20792 | The Motorola m68k configuration includes ColdFire support, and a |
20793 | target command for the following ROM monitor. | |
8e04817f AC |
20794 | |
20795 | @table @code | |
20796 | ||
8e04817f AC |
20797 | @kindex target dbug |
20798 | @item target dbug @var{dev} | |
20799 | dBUG ROM monitor for Motorola ColdFire. | |
20800 | ||
8e04817f AC |
20801 | @end table |
20802 | ||
08be9d71 ME |
20803 | @node MicroBlaze |
20804 | @subsection MicroBlaze | |
20805 | @cindex Xilinx MicroBlaze | |
20806 | @cindex XMD, Xilinx Microprocessor Debugger | |
20807 | ||
20808 | The MicroBlaze is a soft-core processor supported on various Xilinx | |
20809 | FPGAs, such as Spartan or Virtex series. Boards with these processors | |
20810 | usually have JTAG ports which connect to a host system running the Xilinx | |
20811 | Embedded Development Kit (EDK) or Software Development Kit (SDK). | |
20812 | This host system is used to download the configuration bitstream to | |
20813 | the target FPGA. The Xilinx Microprocessor Debugger (XMD) program | |
20814 | communicates with the target board using the JTAG interface and | |
20815 | presents a @code{gdbserver} interface to the board. By default | |
20816 | @code{xmd} uses port @code{1234}. (While it is possible to change | |
20817 | this default port, it requires the use of undocumented @code{xmd} | |
20818 | commands. Contact Xilinx support if you need to do this.) | |
20819 | ||
20820 | Use these GDB commands to connect to the MicroBlaze target processor. | |
20821 | ||
20822 | @table @code | |
20823 | @item target remote :1234 | |
20824 | Use this command to connect to the target if you are running @value{GDBN} | |
20825 | on the same system as @code{xmd}. | |
20826 | ||
20827 | @item target remote @var{xmd-host}:1234 | |
20828 | Use this command to connect to the target if it is connected to @code{xmd} | |
20829 | running on a different system named @var{xmd-host}. | |
20830 | ||
20831 | @item load | |
20832 | Use this command to download a program to the MicroBlaze target. | |
20833 | ||
20834 | @item set debug microblaze @var{n} | |
20835 | Enable MicroBlaze-specific debugging messages if non-zero. | |
20836 | ||
20837 | @item show debug microblaze @var{n} | |
20838 | Show MicroBlaze-specific debugging level. | |
20839 | @end table | |
20840 | ||
8e04817f | 20841 | @node MIPS Embedded |
eb17f351 | 20842 | @subsection @acronym{MIPS} Embedded |
8e04817f | 20843 | |
eb17f351 EZ |
20844 | @cindex @acronym{MIPS} boards |
20845 | @value{GDBN} can use the @acronym{MIPS} remote debugging protocol to talk to a | |
20846 | @acronym{MIPS} board attached to a serial line. This is available when | |
cc30c4bd | 20847 | you configure @value{GDBN} with @samp{--target=mips-elf}. |
104c1213 | 20848 | |
8e04817f AC |
20849 | @need 1000 |
20850 | Use these @value{GDBN} commands to specify the connection to your target board: | |
104c1213 | 20851 | |
8e04817f AC |
20852 | @table @code |
20853 | @item target mips @var{port} | |
20854 | @kindex target mips @var{port} | |
20855 | To run a program on the board, start up @code{@value{GDBP}} with the | |
20856 | name of your program as the argument. To connect to the board, use the | |
20857 | command @samp{target mips @var{port}}, where @var{port} is the name of | |
20858 | the serial port connected to the board. If the program has not already | |
20859 | been downloaded to the board, you may use the @code{load} command to | |
20860 | download it. You can then use all the usual @value{GDBN} commands. | |
104c1213 | 20861 | |
8e04817f AC |
20862 | For example, this sequence connects to the target board through a serial |
20863 | port, and loads and runs a program called @var{prog} through the | |
20864 | debugger: | |
104c1213 | 20865 | |
474c8240 | 20866 | @smallexample |
8e04817f AC |
20867 | host$ @value{GDBP} @var{prog} |
20868 | @value{GDBN} is free software and @dots{} | |
20869 | (@value{GDBP}) target mips /dev/ttyb | |
20870 | (@value{GDBP}) load @var{prog} | |
20871 | (@value{GDBP}) run | |
474c8240 | 20872 | @end smallexample |
104c1213 | 20873 | |
8e04817f AC |
20874 | @item target mips @var{hostname}:@var{portnumber} |
20875 | On some @value{GDBN} host configurations, you can specify a TCP | |
20876 | connection (for instance, to a serial line managed by a terminal | |
20877 | concentrator) instead of a serial port, using the syntax | |
20878 | @samp{@var{hostname}:@var{portnumber}}. | |
104c1213 | 20879 | |
8e04817f AC |
20880 | @item target pmon @var{port} |
20881 | @kindex target pmon @var{port} | |
20882 | PMON ROM monitor. | |
104c1213 | 20883 | |
8e04817f AC |
20884 | @item target ddb @var{port} |
20885 | @kindex target ddb @var{port} | |
20886 | NEC's DDB variant of PMON for Vr4300. | |
104c1213 | 20887 | |
8e04817f AC |
20888 | @item target lsi @var{port} |
20889 | @kindex target lsi @var{port} | |
20890 | LSI variant of PMON. | |
104c1213 | 20891 | |
8e04817f AC |
20892 | @kindex target r3900 |
20893 | @item target r3900 @var{dev} | |
20894 | Densan DVE-R3900 ROM monitor for Toshiba R3900 Mips. | |
104c1213 | 20895 | |
8e04817f AC |
20896 | @kindex target array |
20897 | @item target array @var{dev} | |
20898 | Array Tech LSI33K RAID controller board. | |
104c1213 | 20899 | |
8e04817f | 20900 | @end table |
104c1213 | 20901 | |
104c1213 | 20902 | |
8e04817f | 20903 | @noindent |
eb17f351 | 20904 | @value{GDBN} also supports these special commands for @acronym{MIPS} targets: |
104c1213 | 20905 | |
8e04817f | 20906 | @table @code |
8e04817f AC |
20907 | @item set mipsfpu double |
20908 | @itemx set mipsfpu single | |
20909 | @itemx set mipsfpu none | |
a64548ea | 20910 | @itemx set mipsfpu auto |
8e04817f AC |
20911 | @itemx show mipsfpu |
20912 | @kindex set mipsfpu | |
20913 | @kindex show mipsfpu | |
eb17f351 EZ |
20914 | @cindex @acronym{MIPS} remote floating point |
20915 | @cindex floating point, @acronym{MIPS} remote | |
20916 | If your target board does not support the @acronym{MIPS} floating point | |
8e04817f AC |
20917 | coprocessor, you should use the command @samp{set mipsfpu none} (if you |
20918 | need this, you may wish to put the command in your @value{GDBN} init | |
20919 | file). This tells @value{GDBN} how to find the return value of | |
20920 | functions which return floating point values. It also allows | |
20921 | @value{GDBN} to avoid saving the floating point registers when calling | |
20922 | functions on the board. If you are using a floating point coprocessor | |
20923 | with only single precision floating point support, as on the @sc{r4650} | |
20924 | processor, use the command @samp{set mipsfpu single}. The default | |
20925 | double precision floating point coprocessor may be selected using | |
20926 | @samp{set mipsfpu double}. | |
104c1213 | 20927 | |
8e04817f AC |
20928 | In previous versions the only choices were double precision or no |
20929 | floating point, so @samp{set mipsfpu on} will select double precision | |
20930 | and @samp{set mipsfpu off} will select no floating point. | |
104c1213 | 20931 | |
8e04817f AC |
20932 | As usual, you can inquire about the @code{mipsfpu} variable with |
20933 | @samp{show mipsfpu}. | |
104c1213 | 20934 | |
8e04817f AC |
20935 | @item set timeout @var{seconds} |
20936 | @itemx set retransmit-timeout @var{seconds} | |
20937 | @itemx show timeout | |
20938 | @itemx show retransmit-timeout | |
eb17f351 EZ |
20939 | @cindex @code{timeout}, @acronym{MIPS} protocol |
20940 | @cindex @code{retransmit-timeout}, @acronym{MIPS} protocol | |
8e04817f AC |
20941 | @kindex set timeout |
20942 | @kindex show timeout | |
20943 | @kindex set retransmit-timeout | |
20944 | @kindex show retransmit-timeout | |
eb17f351 | 20945 | You can control the timeout used while waiting for a packet, in the @acronym{MIPS} |
8e04817f AC |
20946 | remote protocol, with the @code{set timeout @var{seconds}} command. The |
20947 | default is 5 seconds. Similarly, you can control the timeout used while | |
a6f3e723 | 20948 | waiting for an acknowledgment of a packet with the @code{set |
8e04817f AC |
20949 | retransmit-timeout @var{seconds}} command. The default is 3 seconds. |
20950 | You can inspect both values with @code{show timeout} and @code{show | |
20951 | retransmit-timeout}. (These commands are @emph{only} available when | |
cc30c4bd | 20952 | @value{GDBN} is configured for @samp{--target=mips-elf}.) |
104c1213 | 20953 | |
8e04817f AC |
20954 | The timeout set by @code{set timeout} does not apply when @value{GDBN} |
20955 | is waiting for your program to stop. In that case, @value{GDBN} waits | |
20956 | forever because it has no way of knowing how long the program is going | |
20957 | to run before stopping. | |
ba04e063 EZ |
20958 | |
20959 | @item set syn-garbage-limit @var{num} | |
eb17f351 EZ |
20960 | @kindex set syn-garbage-limit@r{, @acronym{MIPS} remote} |
20961 | @cindex synchronize with remote @acronym{MIPS} target | |
ba04e063 EZ |
20962 | Limit the maximum number of characters @value{GDBN} should ignore when |
20963 | it tries to synchronize with the remote target. The default is 10 | |
20964 | characters. Setting the limit to -1 means there's no limit. | |
20965 | ||
20966 | @item show syn-garbage-limit | |
eb17f351 | 20967 | @kindex show syn-garbage-limit@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
20968 | Show the current limit on the number of characters to ignore when |
20969 | trying to synchronize with the remote system. | |
20970 | ||
20971 | @item set monitor-prompt @var{prompt} | |
eb17f351 | 20972 | @kindex set monitor-prompt@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
20973 | @cindex remote monitor prompt |
20974 | Tell @value{GDBN} to expect the specified @var{prompt} string from the | |
20975 | remote monitor. The default depends on the target: | |
20976 | @table @asis | |
20977 | @item pmon target | |
20978 | @samp{PMON} | |
20979 | @item ddb target | |
20980 | @samp{NEC010} | |
20981 | @item lsi target | |
20982 | @samp{PMON>} | |
20983 | @end table | |
20984 | ||
20985 | @item show monitor-prompt | |
eb17f351 | 20986 | @kindex show monitor-prompt@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
20987 | Show the current strings @value{GDBN} expects as the prompt from the |
20988 | remote monitor. | |
20989 | ||
20990 | @item set monitor-warnings | |
eb17f351 | 20991 | @kindex set monitor-warnings@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
20992 | Enable or disable monitor warnings about hardware breakpoints. This |
20993 | has effect only for the @code{lsi} target. When on, @value{GDBN} will | |
20994 | display warning messages whose codes are returned by the @code{lsi} | |
20995 | PMON monitor for breakpoint commands. | |
20996 | ||
20997 | @item show monitor-warnings | |
eb17f351 | 20998 | @kindex show monitor-warnings@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
20999 | Show the current setting of printing monitor warnings. |
21000 | ||
21001 | @item pmon @var{command} | |
eb17f351 | 21002 | @kindex pmon@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
21003 | @cindex send PMON command |
21004 | This command allows sending an arbitrary @var{command} string to the | |
21005 | monitor. The monitor must be in debug mode for this to work. | |
8e04817f | 21006 | @end table |
104c1213 | 21007 | |
4acd40f3 TJB |
21008 | @node PowerPC Embedded |
21009 | @subsection PowerPC Embedded | |
104c1213 | 21010 | |
66b73624 TJB |
21011 | @cindex DVC register |
21012 | @value{GDBN} supports using the DVC (Data Value Compare) register to | |
21013 | implement in hardware simple hardware watchpoint conditions of the form: | |
21014 | ||
21015 | @smallexample | |
21016 | (@value{GDBP}) watch @var{ADDRESS|VARIABLE} \ | |
21017 | if @var{ADDRESS|VARIABLE} == @var{CONSTANT EXPRESSION} | |
21018 | @end smallexample | |
21019 | ||
e09342b5 TJB |
21020 | The DVC register will be automatically used when @value{GDBN} detects |
21021 | such pattern in a condition expression, and the created watchpoint uses one | |
21022 | debug register (either the @code{exact-watchpoints} option is on and the | |
21023 | variable is scalar, or the variable has a length of one byte). This feature | |
21024 | is available in native @value{GDBN} running on a Linux kernel version 2.6.34 | |
21025 | or newer. | |
21026 | ||
21027 | When running on PowerPC embedded processors, @value{GDBN} automatically uses | |
21028 | ranged hardware watchpoints, unless the @code{exact-watchpoints} option is on, | |
21029 | in which case watchpoints using only one debug register are created when | |
21030 | watching variables of scalar types. | |
21031 | ||
21032 | You can create an artificial array to watch an arbitrary memory | |
21033 | region using one of the following commands (@pxref{Expressions}): | |
21034 | ||
21035 | @smallexample | |
21036 | (@value{GDBP}) watch *((char *) @var{address})@@@var{length} | |
21037 | (@value{GDBP}) watch @{char[@var{length}]@} @var{address} | |
21038 | @end smallexample | |
66b73624 | 21039 | |
9c06b0b4 TJB |
21040 | PowerPC embedded processors support masked watchpoints. See the discussion |
21041 | about the @code{mask} argument in @ref{Set Watchpoints}. | |
21042 | ||
f1310107 TJB |
21043 | @cindex ranged breakpoint |
21044 | PowerPC embedded processors support hardware accelerated | |
21045 | @dfn{ranged breakpoints}. A ranged breakpoint stops execution of | |
21046 | the inferior whenever it executes an instruction at any address within | |
21047 | the range it specifies. To set a ranged breakpoint in @value{GDBN}, | |
21048 | use the @code{break-range} command. | |
21049 | ||
55eddb0f DJ |
21050 | @value{GDBN} provides the following PowerPC-specific commands: |
21051 | ||
104c1213 | 21052 | @table @code |
f1310107 TJB |
21053 | @kindex break-range |
21054 | @item break-range @var{start-location}, @var{end-location} | |
697aa1b7 EZ |
21055 | Set a breakpoint for an address range given by |
21056 | @var{start-location} and @var{end-location}, which can specify a function name, | |
f1310107 TJB |
21057 | a line number, an offset of lines from the current line or from the start |
21058 | location, or an address of an instruction (see @ref{Specify Location}, | |
21059 | for a list of all the possible ways to specify a @var{location}.) | |
21060 | The breakpoint will stop execution of the inferior whenever it | |
21061 | executes an instruction at any address within the specified range, | |
21062 | (including @var{start-location} and @var{end-location}.) | |
21063 | ||
55eddb0f DJ |
21064 | @kindex set powerpc |
21065 | @item set powerpc soft-float | |
21066 | @itemx show powerpc soft-float | |
21067 | Force @value{GDBN} to use (or not use) a software floating point calling | |
21068 | convention. By default, @value{GDBN} selects the calling convention based | |
21069 | on the selected architecture and the provided executable file. | |
21070 | ||
21071 | @item set powerpc vector-abi | |
21072 | @itemx show powerpc vector-abi | |
21073 | Force @value{GDBN} to use the specified calling convention for vector | |
21074 | arguments and return values. The valid options are @samp{auto}; | |
21075 | @samp{generic}, to avoid vector registers even if they are present; | |
21076 | @samp{altivec}, to use AltiVec registers; and @samp{spe} to use SPE | |
21077 | registers. By default, @value{GDBN} selects the calling convention | |
21078 | based on the selected architecture and the provided executable file. | |
21079 | ||
e09342b5 TJB |
21080 | @item set powerpc exact-watchpoints |
21081 | @itemx show powerpc exact-watchpoints | |
21082 | Allow @value{GDBN} to use only one debug register when watching a variable | |
21083 | of scalar type, thus assuming that the variable is accessed through the | |
21084 | address of its first byte. | |
21085 | ||
8e04817f AC |
21086 | @kindex target dink32 |
21087 | @item target dink32 @var{dev} | |
21088 | DINK32 ROM monitor. | |
104c1213 | 21089 | |
8e04817f AC |
21090 | @kindex target ppcbug |
21091 | @item target ppcbug @var{dev} | |
21092 | @kindex target ppcbug1 | |
21093 | @item target ppcbug1 @var{dev} | |
21094 | PPCBUG ROM monitor for PowerPC. | |
104c1213 | 21095 | |
8e04817f AC |
21096 | @kindex target sds |
21097 | @item target sds @var{dev} | |
21098 | SDS monitor, running on a PowerPC board (such as Motorola's ADS). | |
c45da7e6 | 21099 | @end table |
8e04817f | 21100 | |
c45da7e6 | 21101 | @cindex SDS protocol |
d52fb0e9 | 21102 | The following commands specific to the SDS protocol are supported |
55eddb0f | 21103 | by @value{GDBN}: |
c45da7e6 EZ |
21104 | |
21105 | @table @code | |
21106 | @item set sdstimeout @var{nsec} | |
21107 | @kindex set sdstimeout | |
21108 | Set the timeout for SDS protocol reads to be @var{nsec} seconds. The | |
21109 | default is 2 seconds. | |
21110 | ||
21111 | @item show sdstimeout | |
21112 | @kindex show sdstimeout | |
21113 | Show the current value of the SDS timeout. | |
21114 | ||
21115 | @item sds @var{command} | |
21116 | @kindex sds@r{, a command} | |
21117 | Send the specified @var{command} string to the SDS monitor. | |
8e04817f AC |
21118 | @end table |
21119 | ||
c45da7e6 | 21120 | |
8e04817f AC |
21121 | @node PA |
21122 | @subsection HP PA Embedded | |
104c1213 JM |
21123 | |
21124 | @table @code | |
21125 | ||
8e04817f AC |
21126 | @kindex target op50n |
21127 | @item target op50n @var{dev} | |
21128 | OP50N monitor, running on an OKI HPPA board. | |
21129 | ||
21130 | @kindex target w89k | |
21131 | @item target w89k @var{dev} | |
21132 | W89K monitor, running on a Winbond HPPA board. | |
104c1213 JM |
21133 | |
21134 | @end table | |
21135 | ||
8e04817f AC |
21136 | @node Sparclet |
21137 | @subsection Tsqware Sparclet | |
104c1213 | 21138 | |
8e04817f AC |
21139 | @cindex Sparclet |
21140 | ||
21141 | @value{GDBN} enables developers to debug tasks running on | |
21142 | Sparclet targets from a Unix host. | |
21143 | @value{GDBN} uses code that runs on | |
21144 | both the Unix host and on the Sparclet target. The program | |
21145 | @code{@value{GDBP}} is installed and executed on the Unix host. | |
104c1213 | 21146 | |
8e04817f AC |
21147 | @table @code |
21148 | @item remotetimeout @var{args} | |
21149 | @kindex remotetimeout | |
21150 | @value{GDBN} supports the option @code{remotetimeout}. | |
697aa1b7 | 21151 | This option is set by the user, and @var{args} represents the number of |
8e04817f | 21152 | seconds @value{GDBN} waits for responses. |
104c1213 JM |
21153 | @end table |
21154 | ||
8e04817f AC |
21155 | @cindex compiling, on Sparclet |
21156 | When compiling for debugging, include the options @samp{-g} to get debug | |
21157 | information and @samp{-Ttext} to relocate the program to where you wish to | |
21158 | load it on the target. You may also want to add the options @samp{-n} or | |
21159 | @samp{-N} in order to reduce the size of the sections. Example: | |
104c1213 | 21160 | |
474c8240 | 21161 | @smallexample |
8e04817f | 21162 | sparclet-aout-gcc prog.c -Ttext 0x12010000 -g -o prog -N |
474c8240 | 21163 | @end smallexample |
104c1213 | 21164 | |
8e04817f | 21165 | You can use @code{objdump} to verify that the addresses are what you intended: |
104c1213 | 21166 | |
474c8240 | 21167 | @smallexample |
8e04817f | 21168 | sparclet-aout-objdump --headers --syms prog |
474c8240 | 21169 | @end smallexample |
104c1213 | 21170 | |
8e04817f AC |
21171 | @cindex running, on Sparclet |
21172 | Once you have set | |
21173 | your Unix execution search path to find @value{GDBN}, you are ready to | |
21174 | run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} | |
21175 | (or @code{sparclet-aout-gdb}, depending on your installation). | |
104c1213 | 21176 | |
8e04817f AC |
21177 | @value{GDBN} comes up showing the prompt: |
21178 | ||
474c8240 | 21179 | @smallexample |
8e04817f | 21180 | (gdbslet) |
474c8240 | 21181 | @end smallexample |
104c1213 JM |
21182 | |
21183 | @menu | |
8e04817f AC |
21184 | * Sparclet File:: Setting the file to debug |
21185 | * Sparclet Connection:: Connecting to Sparclet | |
21186 | * Sparclet Download:: Sparclet download | |
21187 | * Sparclet Execution:: Running and debugging | |
104c1213 JM |
21188 | @end menu |
21189 | ||
8e04817f | 21190 | @node Sparclet File |
79a6e687 | 21191 | @subsubsection Setting File to Debug |
104c1213 | 21192 | |
8e04817f | 21193 | The @value{GDBN} command @code{file} lets you choose with program to debug. |
104c1213 | 21194 | |
474c8240 | 21195 | @smallexample |
8e04817f | 21196 | (gdbslet) file prog |
474c8240 | 21197 | @end smallexample |
104c1213 | 21198 | |
8e04817f AC |
21199 | @need 1000 |
21200 | @value{GDBN} then attempts to read the symbol table of @file{prog}. | |
21201 | @value{GDBN} locates | |
21202 | the file by searching the directories listed in the command search | |
21203 | path. | |
12c27660 | 21204 | If the file was compiled with debug information (option @samp{-g}), source |
8e04817f AC |
21205 | files will be searched as well. |
21206 | @value{GDBN} locates | |
21207 | the source files by searching the directories listed in the directory search | |
79a6e687 | 21208 | path (@pxref{Environment, ,Your Program's Environment}). |
8e04817f AC |
21209 | If it fails |
21210 | to find a file, it displays a message such as: | |
104c1213 | 21211 | |
474c8240 | 21212 | @smallexample |
8e04817f | 21213 | prog: No such file or directory. |
474c8240 | 21214 | @end smallexample |
104c1213 | 21215 | |
8e04817f AC |
21216 | When this happens, add the appropriate directories to the search paths with |
21217 | the @value{GDBN} commands @code{path} and @code{dir}, and execute the | |
21218 | @code{target} command again. | |
104c1213 | 21219 | |
8e04817f AC |
21220 | @node Sparclet Connection |
21221 | @subsubsection Connecting to Sparclet | |
104c1213 | 21222 | |
8e04817f AC |
21223 | The @value{GDBN} command @code{target} lets you connect to a Sparclet target. |
21224 | To connect to a target on serial port ``@code{ttya}'', type: | |
104c1213 | 21225 | |
474c8240 | 21226 | @smallexample |
8e04817f AC |
21227 | (gdbslet) target sparclet /dev/ttya |
21228 | Remote target sparclet connected to /dev/ttya | |
21229 | main () at ../prog.c:3 | |
474c8240 | 21230 | @end smallexample |
104c1213 | 21231 | |
8e04817f AC |
21232 | @need 750 |
21233 | @value{GDBN} displays messages like these: | |
104c1213 | 21234 | |
474c8240 | 21235 | @smallexample |
8e04817f | 21236 | Connected to ttya. |
474c8240 | 21237 | @end smallexample |
104c1213 | 21238 | |
8e04817f | 21239 | @node Sparclet Download |
79a6e687 | 21240 | @subsubsection Sparclet Download |
104c1213 | 21241 | |
8e04817f AC |
21242 | @cindex download to Sparclet |
21243 | Once connected to the Sparclet target, | |
21244 | you can use the @value{GDBN} | |
21245 | @code{load} command to download the file from the host to the target. | |
21246 | The file name and load offset should be given as arguments to the @code{load} | |
21247 | command. | |
21248 | Since the file format is aout, the program must be loaded to the starting | |
21249 | address. You can use @code{objdump} to find out what this value is. The load | |
21250 | offset is an offset which is added to the VMA (virtual memory address) | |
21251 | of each of the file's sections. | |
21252 | For instance, if the program | |
21253 | @file{prog} was linked to text address 0x1201000, with data at 0x12010160 | |
21254 | and bss at 0x12010170, in @value{GDBN}, type: | |
104c1213 | 21255 | |
474c8240 | 21256 | @smallexample |
8e04817f AC |
21257 | (gdbslet) load prog 0x12010000 |
21258 | Loading section .text, size 0xdb0 vma 0x12010000 | |
474c8240 | 21259 | @end smallexample |
104c1213 | 21260 | |
8e04817f AC |
21261 | If the code is loaded at a different address then what the program was linked |
21262 | to, you may need to use the @code{section} and @code{add-symbol-file} commands | |
21263 | to tell @value{GDBN} where to map the symbol table. | |
21264 | ||
21265 | @node Sparclet Execution | |
79a6e687 | 21266 | @subsubsection Running and Debugging |
8e04817f AC |
21267 | |
21268 | @cindex running and debugging Sparclet programs | |
21269 | You can now begin debugging the task using @value{GDBN}'s execution control | |
21270 | commands, @code{b}, @code{step}, @code{run}, etc. See the @value{GDBN} | |
21271 | manual for the list of commands. | |
21272 | ||
474c8240 | 21273 | @smallexample |
8e04817f AC |
21274 | (gdbslet) b main |
21275 | Breakpoint 1 at 0x12010000: file prog.c, line 3. | |
21276 | (gdbslet) run | |
21277 | Starting program: prog | |
21278 | Breakpoint 1, main (argc=1, argv=0xeffff21c) at prog.c:3 | |
21279 | 3 char *symarg = 0; | |
21280 | (gdbslet) step | |
21281 | 4 char *execarg = "hello!"; | |
21282 | (gdbslet) | |
474c8240 | 21283 | @end smallexample |
8e04817f AC |
21284 | |
21285 | @node Sparclite | |
21286 | @subsection Fujitsu Sparclite | |
104c1213 JM |
21287 | |
21288 | @table @code | |
21289 | ||
8e04817f AC |
21290 | @kindex target sparclite |
21291 | @item target sparclite @var{dev} | |
21292 | Fujitsu sparclite boards, used only for the purpose of loading. | |
21293 | You must use an additional command to debug the program. | |
21294 | For example: target remote @var{dev} using @value{GDBN} standard | |
21295 | remote protocol. | |
104c1213 JM |
21296 | |
21297 | @end table | |
21298 | ||
8e04817f AC |
21299 | @node Z8000 |
21300 | @subsection Zilog Z8000 | |
104c1213 | 21301 | |
8e04817f AC |
21302 | @cindex Z8000 |
21303 | @cindex simulator, Z8000 | |
21304 | @cindex Zilog Z8000 simulator | |
104c1213 | 21305 | |
8e04817f AC |
21306 | When configured for debugging Zilog Z8000 targets, @value{GDBN} includes |
21307 | a Z8000 simulator. | |
21308 | ||
21309 | For the Z8000 family, @samp{target sim} simulates either the Z8002 (the | |
21310 | unsegmented variant of the Z8000 architecture) or the Z8001 (the | |
21311 | segmented variant). The simulator recognizes which architecture is | |
21312 | appropriate by inspecting the object code. | |
104c1213 | 21313 | |
8e04817f AC |
21314 | @table @code |
21315 | @item target sim @var{args} | |
21316 | @kindex sim | |
21317 | @kindex target sim@r{, with Z8000} | |
21318 | Debug programs on a simulated CPU. If the simulator supports setup | |
21319 | options, specify them via @var{args}. | |
104c1213 JM |
21320 | @end table |
21321 | ||
8e04817f AC |
21322 | @noindent |
21323 | After specifying this target, you can debug programs for the simulated | |
21324 | CPU in the same style as programs for your host computer; use the | |
21325 | @code{file} command to load a new program image, the @code{run} command | |
21326 | to run your program, and so on. | |
21327 | ||
21328 | As well as making available all the usual machine registers | |
21329 | (@pxref{Registers, ,Registers}), the Z8000 simulator provides three | |
21330 | additional items of information as specially named registers: | |
104c1213 JM |
21331 | |
21332 | @table @code | |
21333 | ||
8e04817f AC |
21334 | @item cycles |
21335 | Counts clock-ticks in the simulator. | |
104c1213 | 21336 | |
8e04817f AC |
21337 | @item insts |
21338 | Counts instructions run in the simulator. | |
104c1213 | 21339 | |
8e04817f AC |
21340 | @item time |
21341 | Execution time in 60ths of a second. | |
104c1213 | 21342 | |
8e04817f | 21343 | @end table |
104c1213 | 21344 | |
8e04817f AC |
21345 | You can refer to these values in @value{GDBN} expressions with the usual |
21346 | conventions; for example, @w{@samp{b fputc if $cycles>5000}} sets a | |
21347 | conditional breakpoint that suspends only after at least 5000 | |
21348 | simulated clock ticks. | |
104c1213 | 21349 | |
a64548ea EZ |
21350 | @node AVR |
21351 | @subsection Atmel AVR | |
21352 | @cindex AVR | |
21353 | ||
21354 | When configured for debugging the Atmel AVR, @value{GDBN} supports the | |
21355 | following AVR-specific commands: | |
21356 | ||
21357 | @table @code | |
21358 | @item info io_registers | |
21359 | @kindex info io_registers@r{, AVR} | |
21360 | @cindex I/O registers (Atmel AVR) | |
21361 | This command displays information about the AVR I/O registers. For | |
21362 | each register, @value{GDBN} prints its number and value. | |
21363 | @end table | |
21364 | ||
21365 | @node CRIS | |
21366 | @subsection CRIS | |
21367 | @cindex CRIS | |
21368 | ||
21369 | When configured for debugging CRIS, @value{GDBN} provides the | |
21370 | following CRIS-specific commands: | |
21371 | ||
21372 | @table @code | |
21373 | @item set cris-version @var{ver} | |
21374 | @cindex CRIS version | |
e22e55c9 OF |
21375 | Set the current CRIS version to @var{ver}, either @samp{10} or @samp{32}. |
21376 | The CRIS version affects register names and sizes. This command is useful in | |
21377 | case autodetection of the CRIS version fails. | |
a64548ea EZ |
21378 | |
21379 | @item show cris-version | |
21380 | Show the current CRIS version. | |
21381 | ||
21382 | @item set cris-dwarf2-cfi | |
21383 | @cindex DWARF-2 CFI and CRIS | |
e22e55c9 OF |
21384 | Set the usage of DWARF-2 CFI for CRIS debugging. The default is @samp{on}. |
21385 | Change to @samp{off} when using @code{gcc-cris} whose version is below | |
21386 | @code{R59}. | |
a64548ea EZ |
21387 | |
21388 | @item show cris-dwarf2-cfi | |
21389 | Show the current state of using DWARF-2 CFI. | |
e22e55c9 OF |
21390 | |
21391 | @item set cris-mode @var{mode} | |
21392 | @cindex CRIS mode | |
21393 | Set the current CRIS mode to @var{mode}. It should only be changed when | |
21394 | debugging in guru mode, in which case it should be set to | |
21395 | @samp{guru} (the default is @samp{normal}). | |
21396 | ||
21397 | @item show cris-mode | |
21398 | Show the current CRIS mode. | |
a64548ea EZ |
21399 | @end table |
21400 | ||
21401 | @node Super-H | |
21402 | @subsection Renesas Super-H | |
21403 | @cindex Super-H | |
21404 | ||
21405 | For the Renesas Super-H processor, @value{GDBN} provides these | |
21406 | commands: | |
21407 | ||
21408 | @table @code | |
c055b101 CV |
21409 | @item set sh calling-convention @var{convention} |
21410 | @kindex set sh calling-convention | |
21411 | Set the calling-convention used when calling functions from @value{GDBN}. | |
21412 | Allowed values are @samp{gcc}, which is the default setting, and @samp{renesas}. | |
21413 | With the @samp{gcc} setting, functions are called using the @value{NGCC} calling | |
21414 | convention. If the DWARF-2 information of the called function specifies | |
21415 | that the function follows the Renesas calling convention, the function | |
21416 | is called using the Renesas calling convention. If the calling convention | |
21417 | is set to @samp{renesas}, the Renesas calling convention is always used, | |
21418 | regardless of the DWARF-2 information. This can be used to override the | |
21419 | default of @samp{gcc} if debug information is missing, or the compiler | |
21420 | does not emit the DWARF-2 calling convention entry for a function. | |
21421 | ||
21422 | @item show sh calling-convention | |
21423 | @kindex show sh calling-convention | |
21424 | Show the current calling convention setting. | |
21425 | ||
a64548ea EZ |
21426 | @end table |
21427 | ||
21428 | ||
8e04817f AC |
21429 | @node Architectures |
21430 | @section Architectures | |
104c1213 | 21431 | |
8e04817f AC |
21432 | This section describes characteristics of architectures that affect |
21433 | all uses of @value{GDBN} with the architecture, both native and cross. | |
104c1213 | 21434 | |
8e04817f | 21435 | @menu |
430ed3f0 | 21436 | * AArch64:: |
9c16f35a | 21437 | * i386:: |
8e04817f AC |
21438 | * Alpha:: |
21439 | * MIPS:: | |
a64548ea | 21440 | * HPPA:: HP PA architecture |
23d964e7 | 21441 | * SPU:: Cell Broadband Engine SPU architecture |
4acd40f3 | 21442 | * PowerPC:: |
a1217d97 | 21443 | * Nios II:: |
8e04817f | 21444 | @end menu |
104c1213 | 21445 | |
430ed3f0 MS |
21446 | @node AArch64 |
21447 | @subsection AArch64 | |
21448 | @cindex AArch64 support | |
21449 | ||
21450 | When @value{GDBN} is debugging the AArch64 architecture, it provides the | |
21451 | following special commands: | |
21452 | ||
21453 | @table @code | |
21454 | @item set debug aarch64 | |
21455 | @kindex set debug aarch64 | |
21456 | This command determines whether AArch64 architecture-specific debugging | |
21457 | messages are to be displayed. | |
21458 | ||
21459 | @item show debug aarch64 | |
21460 | Show whether AArch64 debugging messages are displayed. | |
21461 | ||
21462 | @end table | |
21463 | ||
9c16f35a | 21464 | @node i386 |
db2e3e2e | 21465 | @subsection x86 Architecture-specific Issues |
9c16f35a EZ |
21466 | |
21467 | @table @code | |
21468 | @item set struct-convention @var{mode} | |
21469 | @kindex set struct-convention | |
21470 | @cindex struct return convention | |
21471 | @cindex struct/union returned in registers | |
21472 | Set the convention used by the inferior to return @code{struct}s and | |
21473 | @code{union}s from functions to @var{mode}. Possible values of | |
21474 | @var{mode} are @code{"pcc"}, @code{"reg"}, and @code{"default"} (the | |
21475 | default). @code{"default"} or @code{"pcc"} means that @code{struct}s | |
21476 | are returned on the stack, while @code{"reg"} means that a | |
21477 | @code{struct} or a @code{union} whose size is 1, 2, 4, or 8 bytes will | |
21478 | be returned in a register. | |
21479 | ||
21480 | @item show struct-convention | |
21481 | @kindex show struct-convention | |
21482 | Show the current setting of the convention to return @code{struct}s | |
21483 | from functions. | |
3ea8680f | 21484 | @end table |
ca8941bb | 21485 | |
ca8941bb | 21486 | @subsubsection Intel(R) @dfn{Memory Protection Extensions} (MPX). |
22f25c9d | 21487 | @cindex Intel(R) Memory Protection Extensions (MPX). |
ca8941bb | 21488 | |
ca8941bb WT |
21489 | Memory Protection Extension (MPX) adds the bound registers @samp{BND0} |
21490 | @footnote{The register named with capital letters represent the architecture | |
21491 | registers.} through @samp{BND3}. Bound registers store a pair of 64-bit values | |
21492 | which are the lower bound and upper bound. Bounds are effective addresses or | |
21493 | memory locations. The upper bounds are architecturally represented in 1's | |
21494 | complement form. A bound having lower bound = 0, and upper bound = 0 | |
21495 | (1's complement of all bits set) will allow access to the entire address space. | |
21496 | ||
21497 | @samp{BND0} through @samp{BND3} are represented in @value{GDBN} as @samp{bnd0raw} | |
21498 | through @samp{bnd3raw}. Pseudo registers @samp{bnd0} through @samp{bnd3} | |
21499 | display the upper bound performing the complement of one operation on the | |
21500 | upper bound value, i.e.@ when upper bound in @samp{bnd0raw} is 0 in the | |
21501 | @value{GDBN} @samp{bnd0} it will be @code{0xfff@dots{}}. In this sense it | |
21502 | can also be noted that the upper bounds are inclusive. | |
21503 | ||
21504 | As an example, assume that the register BND0 holds bounds for a pointer having | |
21505 | access allowed for the range between 0x32 and 0x71. The values present on | |
21506 | bnd0raw and bnd registers are presented as follows: | |
21507 | ||
21508 | @smallexample | |
21509 | bnd0raw = @{0x32, 0xffffffff8e@} | |
21510 | bnd0 = @{lbound = 0x32, ubound = 0x71@} : size 64 | |
21511 | @end smallexample | |
21512 | ||
22f25c9d EZ |
21513 | This way the raw value can be accessed via bnd0raw@dots{}bnd3raw. Any |
21514 | change on bnd0@dots{}bnd3 or bnd0raw@dots{}bnd3raw is reflect on its | |
21515 | counterpart. When the bnd0@dots{}bnd3 registers are displayed via | |
21516 | Python, the display includes the memory size, in bits, accessible to | |
21517 | the pointer. | |
9c16f35a | 21518 | |
8e04817f AC |
21519 | @node Alpha |
21520 | @subsection Alpha | |
104c1213 | 21521 | |
8e04817f | 21522 | See the following section. |
104c1213 | 21523 | |
8e04817f | 21524 | @node MIPS |
eb17f351 | 21525 | @subsection @acronym{MIPS} |
104c1213 | 21526 | |
8e04817f | 21527 | @cindex stack on Alpha |
eb17f351 | 21528 | @cindex stack on @acronym{MIPS} |
8e04817f | 21529 | @cindex Alpha stack |
eb17f351 EZ |
21530 | @cindex @acronym{MIPS} stack |
21531 | Alpha- and @acronym{MIPS}-based computers use an unusual stack frame, which | |
8e04817f AC |
21532 | sometimes requires @value{GDBN} to search backward in the object code to |
21533 | find the beginning of a function. | |
104c1213 | 21534 | |
eb17f351 | 21535 | @cindex response time, @acronym{MIPS} debugging |
8e04817f AC |
21536 | To improve response time (especially for embedded applications, where |
21537 | @value{GDBN} may be restricted to a slow serial line for this search) | |
21538 | you may want to limit the size of this search, using one of these | |
21539 | commands: | |
104c1213 | 21540 | |
8e04817f | 21541 | @table @code |
eb17f351 | 21542 | @cindex @code{heuristic-fence-post} (Alpha, @acronym{MIPS}) |
8e04817f AC |
21543 | @item set heuristic-fence-post @var{limit} |
21544 | Restrict @value{GDBN} to examining at most @var{limit} bytes in its | |
21545 | search for the beginning of a function. A value of @var{0} (the | |
21546 | default) means there is no limit. However, except for @var{0}, the | |
21547 | larger the limit the more bytes @code{heuristic-fence-post} must search | |
e2f4edfd EZ |
21548 | and therefore the longer it takes to run. You should only need to use |
21549 | this command when debugging a stripped executable. | |
104c1213 | 21550 | |
8e04817f AC |
21551 | @item show heuristic-fence-post |
21552 | Display the current limit. | |
21553 | @end table | |
104c1213 JM |
21554 | |
21555 | @noindent | |
8e04817f | 21556 | These commands are available @emph{only} when @value{GDBN} is configured |
eb17f351 | 21557 | for debugging programs on Alpha or @acronym{MIPS} processors. |
104c1213 | 21558 | |
eb17f351 | 21559 | Several @acronym{MIPS}-specific commands are available when debugging @acronym{MIPS} |
a64548ea EZ |
21560 | programs: |
21561 | ||
21562 | @table @code | |
a64548ea EZ |
21563 | @item set mips abi @var{arg} |
21564 | @kindex set mips abi | |
eb17f351 EZ |
21565 | @cindex set ABI for @acronym{MIPS} |
21566 | Tell @value{GDBN} which @acronym{MIPS} ABI is used by the inferior. Possible | |
a64548ea EZ |
21567 | values of @var{arg} are: |
21568 | ||
21569 | @table @samp | |
21570 | @item auto | |
21571 | The default ABI associated with the current binary (this is the | |
21572 | default). | |
21573 | @item o32 | |
21574 | @item o64 | |
21575 | @item n32 | |
21576 | @item n64 | |
21577 | @item eabi32 | |
21578 | @item eabi64 | |
a64548ea EZ |
21579 | @end table |
21580 | ||
21581 | @item show mips abi | |
21582 | @kindex show mips abi | |
eb17f351 | 21583 | Show the @acronym{MIPS} ABI used by @value{GDBN} to debug the inferior. |
a64548ea | 21584 | |
4cc0665f MR |
21585 | @item set mips compression @var{arg} |
21586 | @kindex set mips compression | |
21587 | @cindex code compression, @acronym{MIPS} | |
21588 | Tell @value{GDBN} which @acronym{MIPS} compressed | |
21589 | @acronym{ISA, Instruction Set Architecture} encoding is used by the | |
21590 | inferior. @value{GDBN} uses this for code disassembly and other | |
21591 | internal interpretation purposes. This setting is only referred to | |
21592 | when no executable has been associated with the debugging session or | |
21593 | the executable does not provide information about the encoding it uses. | |
21594 | Otherwise this setting is automatically updated from information | |
21595 | provided by the executable. | |
21596 | ||
21597 | Possible values of @var{arg} are @samp{mips16} and @samp{micromips}. | |
21598 | The default compressed @acronym{ISA} encoding is @samp{mips16}, as | |
21599 | executables containing @acronym{MIPS16} code frequently are not | |
21600 | identified as such. | |
21601 | ||
21602 | This setting is ``sticky''; that is, it retains its value across | |
21603 | debugging sessions until reset either explicitly with this command or | |
21604 | implicitly from an executable. | |
21605 | ||
21606 | The compiler and/or assembler typically add symbol table annotations to | |
21607 | identify functions compiled for the @acronym{MIPS16} or | |
21608 | @acronym{microMIPS} @acronym{ISA}s. If these function-scope annotations | |
21609 | are present, @value{GDBN} uses them in preference to the global | |
21610 | compressed @acronym{ISA} encoding setting. | |
21611 | ||
21612 | @item show mips compression | |
21613 | @kindex show mips compression | |
21614 | Show the @acronym{MIPS} compressed @acronym{ISA} encoding used by | |
21615 | @value{GDBN} to debug the inferior. | |
21616 | ||
a64548ea EZ |
21617 | @item set mipsfpu |
21618 | @itemx show mipsfpu | |
21619 | @xref{MIPS Embedded, set mipsfpu}. | |
21620 | ||
21621 | @item set mips mask-address @var{arg} | |
21622 | @kindex set mips mask-address | |
eb17f351 | 21623 | @cindex @acronym{MIPS} addresses, masking |
a64548ea | 21624 | This command determines whether the most-significant 32 bits of 64-bit |
eb17f351 | 21625 | @acronym{MIPS} addresses are masked off. The argument @var{arg} can be |
a64548ea EZ |
21626 | @samp{on}, @samp{off}, or @samp{auto}. The latter is the default |
21627 | setting, which lets @value{GDBN} determine the correct value. | |
21628 | ||
21629 | @item show mips mask-address | |
21630 | @kindex show mips mask-address | |
eb17f351 | 21631 | Show whether the upper 32 bits of @acronym{MIPS} addresses are masked off or |
a64548ea EZ |
21632 | not. |
21633 | ||
21634 | @item set remote-mips64-transfers-32bit-regs | |
21635 | @kindex set remote-mips64-transfers-32bit-regs | |
eb17f351 EZ |
21636 | This command controls compatibility with 64-bit @acronym{MIPS} targets that |
21637 | transfer data in 32-bit quantities. If you have an old @acronym{MIPS} 64 target | |
a64548ea EZ |
21638 | that transfers 32 bits for some registers, like @sc{sr} and @sc{fsr}, |
21639 | and 64 bits for other registers, set this option to @samp{on}. | |
21640 | ||
21641 | @item show remote-mips64-transfers-32bit-regs | |
21642 | @kindex show remote-mips64-transfers-32bit-regs | |
eb17f351 | 21643 | Show the current setting of compatibility with older @acronym{MIPS} 64 targets. |
a64548ea EZ |
21644 | |
21645 | @item set debug mips | |
21646 | @kindex set debug mips | |
eb17f351 | 21647 | This command turns on and off debugging messages for the @acronym{MIPS}-specific |
a64548ea EZ |
21648 | target code in @value{GDBN}. |
21649 | ||
21650 | @item show debug mips | |
21651 | @kindex show debug mips | |
eb17f351 | 21652 | Show the current setting of @acronym{MIPS} debugging messages. |
a64548ea EZ |
21653 | @end table |
21654 | ||
21655 | ||
21656 | @node HPPA | |
21657 | @subsection HPPA | |
21658 | @cindex HPPA support | |
21659 | ||
d3e8051b | 21660 | When @value{GDBN} is debugging the HP PA architecture, it provides the |
a64548ea EZ |
21661 | following special commands: |
21662 | ||
21663 | @table @code | |
21664 | @item set debug hppa | |
21665 | @kindex set debug hppa | |
db2e3e2e | 21666 | This command determines whether HPPA architecture-specific debugging |
a64548ea EZ |
21667 | messages are to be displayed. |
21668 | ||
21669 | @item show debug hppa | |
21670 | Show whether HPPA debugging messages are displayed. | |
21671 | ||
21672 | @item maint print unwind @var{address} | |
21673 | @kindex maint print unwind@r{, HPPA} | |
21674 | This command displays the contents of the unwind table entry at the | |
21675 | given @var{address}. | |
21676 | ||
21677 | @end table | |
21678 | ||
104c1213 | 21679 | |
23d964e7 UW |
21680 | @node SPU |
21681 | @subsection Cell Broadband Engine SPU architecture | |
21682 | @cindex Cell Broadband Engine | |
21683 | @cindex SPU | |
21684 | ||
21685 | When @value{GDBN} is debugging the Cell Broadband Engine SPU architecture, | |
21686 | it provides the following special commands: | |
21687 | ||
21688 | @table @code | |
21689 | @item info spu event | |
21690 | @kindex info spu | |
21691 | Display SPU event facility status. Shows current event mask | |
21692 | and pending event status. | |
21693 | ||
21694 | @item info spu signal | |
21695 | Display SPU signal notification facility status. Shows pending | |
21696 | signal-control word and signal notification mode of both signal | |
21697 | notification channels. | |
21698 | ||
21699 | @item info spu mailbox | |
21700 | Display SPU mailbox facility status. Shows all pending entries, | |
21701 | in order of processing, in each of the SPU Write Outbound, | |
21702 | SPU Write Outbound Interrupt, and SPU Read Inbound mailboxes. | |
21703 | ||
21704 | @item info spu dma | |
21705 | Display MFC DMA status. Shows all pending commands in the MFC | |
21706 | DMA queue. For each entry, opcode, tag, class IDs, effective | |
21707 | and local store addresses and transfer size are shown. | |
21708 | ||
21709 | @item info spu proxydma | |
21710 | Display MFC Proxy-DMA status. Shows all pending commands in the MFC | |
21711 | Proxy-DMA queue. For each entry, opcode, tag, class IDs, effective | |
21712 | and local store addresses and transfer size are shown. | |
21713 | ||
21714 | @end table | |
21715 | ||
3285f3fe UW |
21716 | When @value{GDBN} is debugging a combined PowerPC/SPU application |
21717 | on the Cell Broadband Engine, it provides in addition the following | |
21718 | special commands: | |
21719 | ||
21720 | @table @code | |
21721 | @item set spu stop-on-load @var{arg} | |
21722 | @kindex set spu | |
21723 | Set whether to stop for new SPE threads. When set to @code{on}, @value{GDBN} | |
21724 | will give control to the user when a new SPE thread enters its @code{main} | |
21725 | function. The default is @code{off}. | |
21726 | ||
21727 | @item show spu stop-on-load | |
21728 | @kindex show spu | |
21729 | Show whether to stop for new SPE threads. | |
21730 | ||
ff1a52c6 UW |
21731 | @item set spu auto-flush-cache @var{arg} |
21732 | Set whether to automatically flush the software-managed cache. When set to | |
21733 | @code{on}, @value{GDBN} will automatically cause the SPE software-managed | |
21734 | cache to be flushed whenever SPE execution stops. This provides a consistent | |
21735 | view of PowerPC memory that is accessed via the cache. If an application | |
21736 | does not use the software-managed cache, this option has no effect. | |
21737 | ||
21738 | @item show spu auto-flush-cache | |
21739 | Show whether to automatically flush the software-managed cache. | |
21740 | ||
3285f3fe UW |
21741 | @end table |
21742 | ||
4acd40f3 TJB |
21743 | @node PowerPC |
21744 | @subsection PowerPC | |
21745 | @cindex PowerPC architecture | |
21746 | ||
21747 | When @value{GDBN} is debugging the PowerPC architecture, it provides a set of | |
21748 | pseudo-registers to enable inspection of 128-bit wide Decimal Floating Point | |
21749 | numbers stored in the floating point registers. These values must be stored | |
21750 | in two consecutive registers, always starting at an even register like | |
21751 | @code{f0} or @code{f2}. | |
21752 | ||
21753 | The pseudo-registers go from @code{$dl0} through @code{$dl15}, and are formed | |
21754 | by joining the even/odd register pairs @code{f0} and @code{f1} for @code{$dl0}, | |
21755 | @code{f2} and @code{f3} for @code{$dl1} and so on. | |
21756 | ||
aeac0ff9 | 21757 | For POWER7 processors, @value{GDBN} provides a set of pseudo-registers, the 64-bit |
677c5bb1 LM |
21758 | wide Extended Floating Point Registers (@samp{f32} through @samp{f63}). |
21759 | ||
a1217d97 SL |
21760 | @node Nios II |
21761 | @subsection Nios II | |
21762 | @cindex Nios II architecture | |
21763 | ||
21764 | When @value{GDBN} is debugging the Nios II architecture, | |
21765 | it provides the following special commands: | |
21766 | ||
21767 | @table @code | |
21768 | ||
21769 | @item set debug nios2 | |
21770 | @kindex set debug nios2 | |
21771 | This command turns on and off debugging messages for the Nios II | |
21772 | target code in @value{GDBN}. | |
21773 | ||
21774 | @item show debug nios2 | |
21775 | @kindex show debug nios2 | |
21776 | Show the current setting of Nios II debugging messages. | |
21777 | @end table | |
23d964e7 | 21778 | |
8e04817f AC |
21779 | @node Controlling GDB |
21780 | @chapter Controlling @value{GDBN} | |
21781 | ||
21782 | You can alter the way @value{GDBN} interacts with you by using the | |
21783 | @code{set} command. For commands controlling how @value{GDBN} displays | |
79a6e687 | 21784 | data, see @ref{Print Settings, ,Print Settings}. Other settings are |
8e04817f AC |
21785 | described here. |
21786 | ||
21787 | @menu | |
21788 | * Prompt:: Prompt | |
21789 | * Editing:: Command editing | |
d620b259 | 21790 | * Command History:: Command history |
8e04817f AC |
21791 | * Screen Size:: Screen size |
21792 | * Numbers:: Numbers | |
1e698235 | 21793 | * ABI:: Configuring the current ABI |
bf88dd68 | 21794 | * Auto-loading:: Automatically loading associated files |
8e04817f AC |
21795 | * Messages/Warnings:: Optional warnings and messages |
21796 | * Debugging Output:: Optional messages about internal happenings | |
14fb1bac | 21797 | * Other Misc Settings:: Other Miscellaneous Settings |
8e04817f AC |
21798 | @end menu |
21799 | ||
21800 | @node Prompt | |
21801 | @section Prompt | |
104c1213 | 21802 | |
8e04817f | 21803 | @cindex prompt |
104c1213 | 21804 | |
8e04817f AC |
21805 | @value{GDBN} indicates its readiness to read a command by printing a string |
21806 | called the @dfn{prompt}. This string is normally @samp{(@value{GDBP})}. You | |
21807 | can change the prompt string with the @code{set prompt} command. For | |
21808 | instance, when debugging @value{GDBN} with @value{GDBN}, it is useful to change | |
21809 | the prompt in one of the @value{GDBN} sessions so that you can always tell | |
21810 | which one you are talking to. | |
104c1213 | 21811 | |
8e04817f AC |
21812 | @emph{Note:} @code{set prompt} does not add a space for you after the |
21813 | prompt you set. This allows you to set a prompt which ends in a space | |
21814 | or a prompt that does not. | |
104c1213 | 21815 | |
8e04817f AC |
21816 | @table @code |
21817 | @kindex set prompt | |
21818 | @item set prompt @var{newprompt} | |
21819 | Directs @value{GDBN} to use @var{newprompt} as its prompt string henceforth. | |
104c1213 | 21820 | |
8e04817f AC |
21821 | @kindex show prompt |
21822 | @item show prompt | |
21823 | Prints a line of the form: @samp{Gdb's prompt is: @var{your-prompt}} | |
104c1213 JM |
21824 | @end table |
21825 | ||
fa3a4f15 PM |
21826 | Versions of @value{GDBN} that ship with Python scripting enabled have |
21827 | prompt extensions. The commands for interacting with these extensions | |
21828 | are: | |
21829 | ||
21830 | @table @code | |
21831 | @kindex set extended-prompt | |
21832 | @item set extended-prompt @var{prompt} | |
21833 | Set an extended prompt that allows for substitutions. | |
21834 | @xref{gdb.prompt}, for a list of escape sequences that can be used for | |
21835 | substitution. Any escape sequences specified as part of the prompt | |
21836 | string are replaced with the corresponding strings each time the prompt | |
21837 | is displayed. | |
21838 | ||
21839 | For example: | |
21840 | ||
21841 | @smallexample | |
21842 | set extended-prompt Current working directory: \w (gdb) | |
21843 | @end smallexample | |
21844 | ||
21845 | Note that when an extended-prompt is set, it takes control of the | |
21846 | @var{prompt_hook} hook. @xref{prompt_hook}, for further information. | |
21847 | ||
21848 | @kindex show extended-prompt | |
21849 | @item show extended-prompt | |
21850 | Prints the extended prompt. Any escape sequences specified as part of | |
21851 | the prompt string with @code{set extended-prompt}, are replaced with the | |
21852 | corresponding strings each time the prompt is displayed. | |
21853 | @end table | |
21854 | ||
8e04817f | 21855 | @node Editing |
79a6e687 | 21856 | @section Command Editing |
8e04817f AC |
21857 | @cindex readline |
21858 | @cindex command line editing | |
104c1213 | 21859 | |
703663ab | 21860 | @value{GDBN} reads its input commands via the @dfn{Readline} interface. This |
8e04817f AC |
21861 | @sc{gnu} library provides consistent behavior for programs which provide a |
21862 | command line interface to the user. Advantages are @sc{gnu} Emacs-style | |
21863 | or @dfn{vi}-style inline editing of commands, @code{csh}-like history | |
21864 | substitution, and a storage and recall of command history across | |
21865 | debugging sessions. | |
104c1213 | 21866 | |
8e04817f AC |
21867 | You may control the behavior of command line editing in @value{GDBN} with the |
21868 | command @code{set}. | |
104c1213 | 21869 | |
8e04817f AC |
21870 | @table @code |
21871 | @kindex set editing | |
21872 | @cindex editing | |
21873 | @item set editing | |
21874 | @itemx set editing on | |
21875 | Enable command line editing (enabled by default). | |
104c1213 | 21876 | |
8e04817f AC |
21877 | @item set editing off |
21878 | Disable command line editing. | |
104c1213 | 21879 | |
8e04817f AC |
21880 | @kindex show editing |
21881 | @item show editing | |
21882 | Show whether command line editing is enabled. | |
104c1213 JM |
21883 | @end table |
21884 | ||
39037522 TT |
21885 | @ifset SYSTEM_READLINE |
21886 | @xref{Command Line Editing, , , rluserman, GNU Readline Library}, | |
21887 | @end ifset | |
21888 | @ifclear SYSTEM_READLINE | |
21889 | @xref{Command Line Editing}, | |
21890 | @end ifclear | |
21891 | for more details about the Readline | |
703663ab EZ |
21892 | interface. Users unfamiliar with @sc{gnu} Emacs or @code{vi} are |
21893 | encouraged to read that chapter. | |
21894 | ||
d620b259 | 21895 | @node Command History |
79a6e687 | 21896 | @section Command History |
703663ab | 21897 | @cindex command history |
8e04817f AC |
21898 | |
21899 | @value{GDBN} can keep track of the commands you type during your | |
21900 | debugging sessions, so that you can be certain of precisely what | |
21901 | happened. Use these commands to manage the @value{GDBN} command | |
21902 | history facility. | |
104c1213 | 21903 | |
703663ab | 21904 | @value{GDBN} uses the @sc{gnu} History library, a part of the Readline |
39037522 TT |
21905 | package, to provide the history facility. |
21906 | @ifset SYSTEM_READLINE | |
21907 | @xref{Using History Interactively, , , history, GNU History Library}, | |
21908 | @end ifset | |
21909 | @ifclear SYSTEM_READLINE | |
21910 | @xref{Using History Interactively}, | |
21911 | @end ifclear | |
21912 | for the detailed description of the History library. | |
703663ab | 21913 | |
d620b259 | 21914 | To issue a command to @value{GDBN} without affecting certain aspects of |
9e6c4bd5 NR |
21915 | the state which is seen by users, prefix it with @samp{server } |
21916 | (@pxref{Server Prefix}). This | |
d620b259 NR |
21917 | means that this command will not affect the command history, nor will it |
21918 | affect @value{GDBN}'s notion of which command to repeat if @key{RET} is | |
21919 | pressed on a line by itself. | |
21920 | ||
21921 | @cindex @code{server}, command prefix | |
21922 | The server prefix does not affect the recording of values into the value | |
21923 | history; to print a value without recording it into the value history, | |
21924 | use the @code{output} command instead of the @code{print} command. | |
21925 | ||
703663ab EZ |
21926 | Here is the description of @value{GDBN} commands related to command |
21927 | history. | |
21928 | ||
104c1213 | 21929 | @table @code |
8e04817f AC |
21930 | @cindex history substitution |
21931 | @cindex history file | |
21932 | @kindex set history filename | |
4644b6e3 | 21933 | @cindex @env{GDBHISTFILE}, environment variable |
8e04817f AC |
21934 | @item set history filename @var{fname} |
21935 | Set the name of the @value{GDBN} command history file to @var{fname}. | |
21936 | This is the file where @value{GDBN} reads an initial command history | |
21937 | list, and where it writes the command history from this session when it | |
21938 | exits. You can access this list through history expansion or through | |
21939 | the history command editing characters listed below. This file defaults | |
21940 | to the value of the environment variable @code{GDBHISTFILE}, or to | |
21941 | @file{./.gdb_history} (@file{./_gdb_history} on MS-DOS) if this variable | |
21942 | is not set. | |
104c1213 | 21943 | |
9c16f35a EZ |
21944 | @cindex save command history |
21945 | @kindex set history save | |
8e04817f AC |
21946 | @item set history save |
21947 | @itemx set history save on | |
21948 | Record command history in a file, whose name may be specified with the | |
21949 | @code{set history filename} command. By default, this option is disabled. | |
104c1213 | 21950 | |
8e04817f AC |
21951 | @item set history save off |
21952 | Stop recording command history in a file. | |
104c1213 | 21953 | |
8e04817f | 21954 | @cindex history size |
9c16f35a | 21955 | @kindex set history size |
6fc08d32 | 21956 | @cindex @env{HISTSIZE}, environment variable |
8e04817f | 21957 | @item set history size @var{size} |
f81d1120 | 21958 | @itemx set history size unlimited |
8e04817f AC |
21959 | Set the number of commands which @value{GDBN} keeps in its history list. |
21960 | This defaults to the value of the environment variable | |
f81d1120 PA |
21961 | @code{HISTSIZE}, or to 256 if this variable is not set. If @var{size} |
21962 | is @code{unlimited}, the number of commands @value{GDBN} keeps in the | |
21963 | history list is unlimited. | |
104c1213 JM |
21964 | @end table |
21965 | ||
8e04817f | 21966 | History expansion assigns special meaning to the character @kbd{!}. |
39037522 TT |
21967 | @ifset SYSTEM_READLINE |
21968 | @xref{Event Designators, , , history, GNU History Library}, | |
21969 | @end ifset | |
21970 | @ifclear SYSTEM_READLINE | |
21971 | @xref{Event Designators}, | |
21972 | @end ifclear | |
21973 | for more details. | |
8e04817f | 21974 | |
703663ab | 21975 | @cindex history expansion, turn on/off |
8e04817f AC |
21976 | Since @kbd{!} is also the logical not operator in C, history expansion |
21977 | is off by default. If you decide to enable history expansion with the | |
21978 | @code{set history expansion on} command, you may sometimes need to | |
21979 | follow @kbd{!} (when it is used as logical not, in an expression) with | |
21980 | a space or a tab to prevent it from being expanded. The readline | |
21981 | history facilities do not attempt substitution on the strings | |
21982 | @kbd{!=} and @kbd{!(}, even when history expansion is enabled. | |
21983 | ||
21984 | The commands to control history expansion are: | |
104c1213 JM |
21985 | |
21986 | @table @code | |
8e04817f AC |
21987 | @item set history expansion on |
21988 | @itemx set history expansion | |
703663ab | 21989 | @kindex set history expansion |
8e04817f | 21990 | Enable history expansion. History expansion is off by default. |
104c1213 | 21991 | |
8e04817f AC |
21992 | @item set history expansion off |
21993 | Disable history expansion. | |
104c1213 | 21994 | |
8e04817f AC |
21995 | @c @group |
21996 | @kindex show history | |
21997 | @item show history | |
21998 | @itemx show history filename | |
21999 | @itemx show history save | |
22000 | @itemx show history size | |
22001 | @itemx show history expansion | |
22002 | These commands display the state of the @value{GDBN} history parameters. | |
22003 | @code{show history} by itself displays all four states. | |
22004 | @c @end group | |
22005 | @end table | |
22006 | ||
22007 | @table @code | |
9c16f35a EZ |
22008 | @kindex show commands |
22009 | @cindex show last commands | |
22010 | @cindex display command history | |
8e04817f AC |
22011 | @item show commands |
22012 | Display the last ten commands in the command history. | |
104c1213 | 22013 | |
8e04817f AC |
22014 | @item show commands @var{n} |
22015 | Print ten commands centered on command number @var{n}. | |
22016 | ||
22017 | @item show commands + | |
22018 | Print ten commands just after the commands last printed. | |
104c1213 JM |
22019 | @end table |
22020 | ||
8e04817f | 22021 | @node Screen Size |
79a6e687 | 22022 | @section Screen Size |
8e04817f | 22023 | @cindex size of screen |
f179cf97 EZ |
22024 | @cindex screen size |
22025 | @cindex pagination | |
22026 | @cindex page size | |
8e04817f | 22027 | @cindex pauses in output |
104c1213 | 22028 | |
8e04817f AC |
22029 | Certain commands to @value{GDBN} may produce large amounts of |
22030 | information output to the screen. To help you read all of it, | |
22031 | @value{GDBN} pauses and asks you for input at the end of each page of | |
22032 | output. Type @key{RET} when you want to continue the output, or @kbd{q} | |
22033 | to discard the remaining output. Also, the screen width setting | |
22034 | determines when to wrap lines of output. Depending on what is being | |
22035 | printed, @value{GDBN} tries to break the line at a readable place, | |
22036 | rather than simply letting it overflow onto the following line. | |
22037 | ||
22038 | Normally @value{GDBN} knows the size of the screen from the terminal | |
22039 | driver software. For example, on Unix @value{GDBN} uses the termcap data base | |
22040 | together with the value of the @code{TERM} environment variable and the | |
22041 | @code{stty rows} and @code{stty cols} settings. If this is not correct, | |
22042 | you can override it with the @code{set height} and @code{set | |
22043 | width} commands: | |
22044 | ||
22045 | @table @code | |
22046 | @kindex set height | |
22047 | @kindex set width | |
22048 | @kindex show width | |
22049 | @kindex show height | |
22050 | @item set height @var{lpp} | |
f81d1120 | 22051 | @itemx set height unlimited |
8e04817f AC |
22052 | @itemx show height |
22053 | @itemx set width @var{cpl} | |
f81d1120 | 22054 | @itemx set width unlimited |
8e04817f AC |
22055 | @itemx show width |
22056 | These @code{set} commands specify a screen height of @var{lpp} lines and | |
22057 | a screen width of @var{cpl} characters. The associated @code{show} | |
22058 | commands display the current settings. | |
104c1213 | 22059 | |
f81d1120 PA |
22060 | If you specify a height of either @code{unlimited} or zero lines, |
22061 | @value{GDBN} does not pause during output no matter how long the | |
22062 | output is. This is useful if output is to a file or to an editor | |
22063 | buffer. | |
104c1213 | 22064 | |
f81d1120 PA |
22065 | Likewise, you can specify @samp{set width unlimited} or @samp{set |
22066 | width 0} to prevent @value{GDBN} from wrapping its output. | |
9c16f35a EZ |
22067 | |
22068 | @item set pagination on | |
22069 | @itemx set pagination off | |
22070 | @kindex set pagination | |
22071 | Turn the output pagination on or off; the default is on. Turning | |
f81d1120 | 22072 | pagination off is the alternative to @code{set height unlimited}. Note that |
7c953934 TT |
22073 | running @value{GDBN} with the @option{--batch} option (@pxref{Mode |
22074 | Options, -batch}) also automatically disables pagination. | |
9c16f35a EZ |
22075 | |
22076 | @item show pagination | |
22077 | @kindex show pagination | |
22078 | Show the current pagination mode. | |
104c1213 JM |
22079 | @end table |
22080 | ||
8e04817f AC |
22081 | @node Numbers |
22082 | @section Numbers | |
22083 | @cindex number representation | |
22084 | @cindex entering numbers | |
104c1213 | 22085 | |
8e04817f AC |
22086 | You can always enter numbers in octal, decimal, or hexadecimal in |
22087 | @value{GDBN} by the usual conventions: octal numbers begin with | |
22088 | @samp{0}, decimal numbers end with @samp{.}, and hexadecimal numbers | |
eb2dae08 EZ |
22089 | begin with @samp{0x}. Numbers that neither begin with @samp{0} or |
22090 | @samp{0x}, nor end with a @samp{.} are, by default, entered in base | |
22091 | 10; likewise, the default display for numbers---when no particular | |
22092 | format is specified---is base 10. You can change the default base for | |
22093 | both input and output with the commands described below. | |
104c1213 | 22094 | |
8e04817f AC |
22095 | @table @code |
22096 | @kindex set input-radix | |
22097 | @item set input-radix @var{base} | |
22098 | Set the default base for numeric input. Supported choices | |
697aa1b7 | 22099 | for @var{base} are decimal 8, 10, or 16. The base must itself be |
eb2dae08 | 22100 | specified either unambiguously or using the current input radix; for |
8e04817f | 22101 | example, any of |
104c1213 | 22102 | |
8e04817f | 22103 | @smallexample |
9c16f35a EZ |
22104 | set input-radix 012 |
22105 | set input-radix 10. | |
22106 | set input-radix 0xa | |
8e04817f | 22107 | @end smallexample |
104c1213 | 22108 | |
8e04817f | 22109 | @noindent |
9c16f35a | 22110 | sets the input base to decimal. On the other hand, @samp{set input-radix 10} |
eb2dae08 EZ |
22111 | leaves the input radix unchanged, no matter what it was, since |
22112 | @samp{10}, being without any leading or trailing signs of its base, is | |
22113 | interpreted in the current radix. Thus, if the current radix is 16, | |
22114 | @samp{10} is interpreted in hex, i.e.@: as 16 decimal, which doesn't | |
22115 | change the radix. | |
104c1213 | 22116 | |
8e04817f AC |
22117 | @kindex set output-radix |
22118 | @item set output-radix @var{base} | |
22119 | Set the default base for numeric display. Supported choices | |
697aa1b7 | 22120 | for @var{base} are decimal 8, 10, or 16. The base must itself be |
eb2dae08 | 22121 | specified either unambiguously or using the current input radix. |
104c1213 | 22122 | |
8e04817f AC |
22123 | @kindex show input-radix |
22124 | @item show input-radix | |
22125 | Display the current default base for numeric input. | |
104c1213 | 22126 | |
8e04817f AC |
22127 | @kindex show output-radix |
22128 | @item show output-radix | |
22129 | Display the current default base for numeric display. | |
9c16f35a EZ |
22130 | |
22131 | @item set radix @r{[}@var{base}@r{]} | |
22132 | @itemx show radix | |
22133 | @kindex set radix | |
22134 | @kindex show radix | |
22135 | These commands set and show the default base for both input and output | |
22136 | of numbers. @code{set radix} sets the radix of input and output to | |
22137 | the same base; without an argument, it resets the radix back to its | |
22138 | default value of 10. | |
22139 | ||
8e04817f | 22140 | @end table |
104c1213 | 22141 | |
1e698235 | 22142 | @node ABI |
79a6e687 | 22143 | @section Configuring the Current ABI |
1e698235 DJ |
22144 | |
22145 | @value{GDBN} can determine the @dfn{ABI} (Application Binary Interface) of your | |
22146 | application automatically. However, sometimes you need to override its | |
22147 | conclusions. Use these commands to manage @value{GDBN}'s view of the | |
22148 | current ABI. | |
22149 | ||
98b45e30 DJ |
22150 | @cindex OS ABI |
22151 | @kindex set osabi | |
b4e9345d | 22152 | @kindex show osabi |
430ed3f0 | 22153 | @cindex Newlib OS ABI and its influence on the longjmp handling |
98b45e30 DJ |
22154 | |
22155 | One @value{GDBN} configuration can debug binaries for multiple operating | |
b383017d | 22156 | system targets, either via remote debugging or native emulation. |
98b45e30 DJ |
22157 | @value{GDBN} will autodetect the @dfn{OS ABI} (Operating System ABI) in use, |
22158 | but you can override its conclusion using the @code{set osabi} command. | |
22159 | One example where this is useful is in debugging of binaries which use | |
22160 | an alternate C library (e.g.@: @sc{uClibc} for @sc{gnu}/Linux) which does | |
22161 | not have the same identifying marks that the standard C library for your | |
22162 | platform provides. | |
22163 | ||
430ed3f0 MS |
22164 | When @value{GDBN} is debugging the AArch64 architecture, it provides a |
22165 | ``Newlib'' OS ABI. This is useful for handling @code{setjmp} and | |
22166 | @code{longjmp} when debugging binaries that use the @sc{newlib} C library. | |
22167 | The ``Newlib'' OS ABI can be selected by @code{set osabi Newlib}. | |
22168 | ||
98b45e30 DJ |
22169 | @table @code |
22170 | @item show osabi | |
22171 | Show the OS ABI currently in use. | |
22172 | ||
22173 | @item set osabi | |
22174 | With no argument, show the list of registered available OS ABI's. | |
22175 | ||
22176 | @item set osabi @var{abi} | |
22177 | Set the current OS ABI to @var{abi}. | |
22178 | @end table | |
22179 | ||
1e698235 | 22180 | @cindex float promotion |
1e698235 DJ |
22181 | |
22182 | Generally, the way that an argument of type @code{float} is passed to a | |
22183 | function depends on whether the function is prototyped. For a prototyped | |
22184 | (i.e.@: ANSI/ISO style) function, @code{float} arguments are passed unchanged, | |
22185 | according to the architecture's convention for @code{float}. For unprototyped | |
22186 | (i.e.@: K&R style) functions, @code{float} arguments are first promoted to type | |
22187 | @code{double} and then passed. | |
22188 | ||
22189 | Unfortunately, some forms of debug information do not reliably indicate whether | |
22190 | a function is prototyped. If @value{GDBN} calls a function that is not marked | |
22191 | as prototyped, it consults @kbd{set coerce-float-to-double}. | |
22192 | ||
22193 | @table @code | |
a8f24a35 | 22194 | @kindex set coerce-float-to-double |
1e698235 DJ |
22195 | @item set coerce-float-to-double |
22196 | @itemx set coerce-float-to-double on | |
22197 | Arguments of type @code{float} will be promoted to @code{double} when passed | |
22198 | to an unprototyped function. This is the default setting. | |
22199 | ||
22200 | @item set coerce-float-to-double off | |
22201 | Arguments of type @code{float} will be passed directly to unprototyped | |
22202 | functions. | |
9c16f35a EZ |
22203 | |
22204 | @kindex show coerce-float-to-double | |
22205 | @item show coerce-float-to-double | |
22206 | Show the current setting of promoting @code{float} to @code{double}. | |
1e698235 DJ |
22207 | @end table |
22208 | ||
f1212245 DJ |
22209 | @kindex set cp-abi |
22210 | @kindex show cp-abi | |
22211 | @value{GDBN} needs to know the ABI used for your program's C@t{++} | |
22212 | objects. The correct C@t{++} ABI depends on which C@t{++} compiler was | |
22213 | used to build your application. @value{GDBN} only fully supports | |
22214 | programs with a single C@t{++} ABI; if your program contains code using | |
22215 | multiple C@t{++} ABI's or if @value{GDBN} can not identify your | |
22216 | program's ABI correctly, you can tell @value{GDBN} which ABI to use. | |
22217 | Currently supported ABI's include ``gnu-v2'', for @code{g++} versions | |
22218 | before 3.0, ``gnu-v3'', for @code{g++} versions 3.0 and later, and | |
22219 | ``hpaCC'' for the HP ANSI C@t{++} compiler. Other C@t{++} compilers may | |
22220 | use the ``gnu-v2'' or ``gnu-v3'' ABI's as well. The default setting is | |
22221 | ``auto''. | |
22222 | ||
22223 | @table @code | |
22224 | @item show cp-abi | |
22225 | Show the C@t{++} ABI currently in use. | |
22226 | ||
22227 | @item set cp-abi | |
22228 | With no argument, show the list of supported C@t{++} ABI's. | |
22229 | ||
22230 | @item set cp-abi @var{abi} | |
22231 | @itemx set cp-abi auto | |
22232 | Set the current C@t{++} ABI to @var{abi}, or return to automatic detection. | |
22233 | @end table | |
22234 | ||
bf88dd68 JK |
22235 | @node Auto-loading |
22236 | @section Automatically loading associated files | |
22237 | @cindex auto-loading | |
22238 | ||
22239 | @value{GDBN} sometimes reads files with commands and settings automatically, | |
22240 | without being explicitly told so by the user. We call this feature | |
22241 | @dfn{auto-loading}. While auto-loading is useful for automatically adapting | |
22242 | @value{GDBN} to the needs of your project, it can sometimes produce unexpected | |
22243 | results or introduce security risks (e.g., if the file comes from untrusted | |
22244 | sources). | |
22245 | ||
71b8c845 DE |
22246 | @menu |
22247 | * Init File in the Current Directory:: @samp{set/show/info auto-load local-gdbinit} | |
22248 | * libthread_db.so.1 file:: @samp{set/show/info auto-load libthread-db} | |
22249 | ||
22250 | * Auto-loading safe path:: @samp{set/show/info auto-load safe-path} | |
22251 | * Auto-loading verbose mode:: @samp{set/show debug auto-load} | |
22252 | @end menu | |
22253 | ||
22254 | There are various kinds of files @value{GDBN} can automatically load. | |
22255 | In addition to these files, @value{GDBN} supports auto-loading code written | |
22256 | in various extension languages. @xref{Auto-loading extensions}. | |
22257 | ||
c1668e4e JK |
22258 | Note that loading of these associated files (including the local @file{.gdbinit} |
22259 | file) requires accordingly configured @code{auto-load safe-path} | |
22260 | (@pxref{Auto-loading safe path}). | |
22261 | ||
bf88dd68 JK |
22262 | For these reasons, @value{GDBN} includes commands and options to let you |
22263 | control when to auto-load files and which files should be auto-loaded. | |
22264 | ||
22265 | @table @code | |
22266 | @anchor{set auto-load off} | |
22267 | @kindex set auto-load off | |
22268 | @item set auto-load off | |
22269 | Globally disable loading of all auto-loaded files. | |
22270 | You may want to use this command with the @samp{-iex} option | |
22271 | (@pxref{Option -init-eval-command}) such as: | |
22272 | @smallexample | |
22273 | $ @kbd{gdb -iex "set auto-load off" untrusted-executable corefile} | |
22274 | @end smallexample | |
22275 | ||
22276 | Be aware that system init file (@pxref{System-wide configuration}) | |
22277 | and init files from your home directory (@pxref{Home Directory Init File}) | |
22278 | still get read (as they come from generally trusted directories). | |
22279 | To prevent @value{GDBN} from auto-loading even those init files, use the | |
22280 | @option{-nx} option (@pxref{Mode Options}), in addition to | |
22281 | @code{set auto-load no}. | |
22282 | ||
22283 | @anchor{show auto-load} | |
22284 | @kindex show auto-load | |
22285 | @item show auto-load | |
22286 | Show whether auto-loading of each specific @samp{auto-load} file(s) is enabled | |
22287 | or disabled. | |
22288 | ||
22289 | @smallexample | |
22290 | (gdb) show auto-load | |
22291 | gdb-scripts: Auto-loading of canned sequences of commands scripts is on. | |
22292 | libthread-db: Auto-loading of inferior specific libthread_db is on. | |
1ccacbcd JK |
22293 | local-gdbinit: Auto-loading of .gdbinit script from current directory |
22294 | is on. | |
bf88dd68 | 22295 | python-scripts: Auto-loading of Python scripts is on. |
bccbefd2 | 22296 | safe-path: List of directories from which it is safe to auto-load files |
1564a261 | 22297 | is $debugdir:$datadir/auto-load. |
7349ff92 | 22298 | scripts-directory: List of directories from which to load auto-loaded scripts |
1564a261 | 22299 | is $debugdir:$datadir/auto-load. |
bf88dd68 JK |
22300 | @end smallexample |
22301 | ||
22302 | @anchor{info auto-load} | |
22303 | @kindex info auto-load | |
22304 | @item info auto-load | |
22305 | Print whether each specific @samp{auto-load} file(s) have been auto-loaded or | |
22306 | not. | |
22307 | ||
22308 | @smallexample | |
22309 | (gdb) info auto-load | |
22310 | gdb-scripts: | |
22311 | Loaded Script | |
22312 | Yes /home/user/gdb/gdb-gdb.gdb | |
22313 | libthread-db: No auto-loaded libthread-db. | |
1ccacbcd JK |
22314 | local-gdbinit: Local .gdbinit file "/home/user/gdb/.gdbinit" has been |
22315 | loaded. | |
bf88dd68 JK |
22316 | python-scripts: |
22317 | Loaded Script | |
22318 | Yes /home/user/gdb/gdb-gdb.py | |
22319 | @end smallexample | |
22320 | @end table | |
22321 | ||
bf88dd68 JK |
22322 | These are @value{GDBN} control commands for the auto-loading: |
22323 | ||
22324 | @multitable @columnfractions .5 .5 | |
22325 | @item @xref{set auto-load off}. | |
22326 | @tab Disable auto-loading globally. | |
22327 | @item @xref{show auto-load}. | |
22328 | @tab Show setting of all kinds of files. | |
22329 | @item @xref{info auto-load}. | |
22330 | @tab Show state of all kinds of files. | |
22331 | @item @xref{set auto-load gdb-scripts}. | |
22332 | @tab Control for @value{GDBN} command scripts. | |
22333 | @item @xref{show auto-load gdb-scripts}. | |
22334 | @tab Show setting of @value{GDBN} command scripts. | |
22335 | @item @xref{info auto-load gdb-scripts}. | |
22336 | @tab Show state of @value{GDBN} command scripts. | |
22337 | @item @xref{set auto-load python-scripts}. | |
22338 | @tab Control for @value{GDBN} Python scripts. | |
22339 | @item @xref{show auto-load python-scripts}. | |
22340 | @tab Show setting of @value{GDBN} Python scripts. | |
22341 | @item @xref{info auto-load python-scripts}. | |
22342 | @tab Show state of @value{GDBN} Python scripts. | |
ed3ef339 DE |
22343 | @item @xref{set auto-load guile-scripts}. |
22344 | @tab Control for @value{GDBN} Guile scripts. | |
22345 | @item @xref{show auto-load guile-scripts}. | |
22346 | @tab Show setting of @value{GDBN} Guile scripts. | |
22347 | @item @xref{info auto-load guile-scripts}. | |
22348 | @tab Show state of @value{GDBN} Guile scripts. | |
7349ff92 JK |
22349 | @item @xref{set auto-load scripts-directory}. |
22350 | @tab Control for @value{GDBN} auto-loaded scripts location. | |
22351 | @item @xref{show auto-load scripts-directory}. | |
22352 | @tab Show @value{GDBN} auto-loaded scripts location. | |
bf88dd68 JK |
22353 | @item @xref{set auto-load local-gdbinit}. |
22354 | @tab Control for init file in the current directory. | |
22355 | @item @xref{show auto-load local-gdbinit}. | |
22356 | @tab Show setting of init file in the current directory. | |
22357 | @item @xref{info auto-load local-gdbinit}. | |
22358 | @tab Show state of init file in the current directory. | |
22359 | @item @xref{set auto-load libthread-db}. | |
22360 | @tab Control for thread debugging library. | |
22361 | @item @xref{show auto-load libthread-db}. | |
22362 | @tab Show setting of thread debugging library. | |
22363 | @item @xref{info auto-load libthread-db}. | |
22364 | @tab Show state of thread debugging library. | |
bccbefd2 JK |
22365 | @item @xref{set auto-load safe-path}. |
22366 | @tab Control directories trusted for automatic loading. | |
22367 | @item @xref{show auto-load safe-path}. | |
22368 | @tab Show directories trusted for automatic loading. | |
22369 | @item @xref{add-auto-load-safe-path}. | |
22370 | @tab Add directory trusted for automatic loading. | |
bf88dd68 JK |
22371 | @end multitable |
22372 | ||
bf88dd68 JK |
22373 | @node Init File in the Current Directory |
22374 | @subsection Automatically loading init file in the current directory | |
22375 | @cindex auto-loading init file in the current directory | |
22376 | ||
22377 | By default, @value{GDBN} reads and executes the canned sequences of commands | |
22378 | from init file (if any) in the current working directory, | |
22379 | see @ref{Init File in the Current Directory during Startup}. | |
22380 | ||
c1668e4e JK |
22381 | Note that loading of this local @file{.gdbinit} file also requires accordingly |
22382 | configured @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
22383 | ||
bf88dd68 JK |
22384 | @table @code |
22385 | @anchor{set auto-load local-gdbinit} | |
22386 | @kindex set auto-load local-gdbinit | |
22387 | @item set auto-load local-gdbinit [on|off] | |
22388 | Enable or disable the auto-loading of canned sequences of commands | |
22389 | (@pxref{Sequences}) found in init file in the current directory. | |
22390 | ||
22391 | @anchor{show auto-load local-gdbinit} | |
22392 | @kindex show auto-load local-gdbinit | |
22393 | @item show auto-load local-gdbinit | |
22394 | Show whether auto-loading of canned sequences of commands from init file in the | |
22395 | current directory is enabled or disabled. | |
22396 | ||
22397 | @anchor{info auto-load local-gdbinit} | |
22398 | @kindex info auto-load local-gdbinit | |
22399 | @item info auto-load local-gdbinit | |
22400 | Print whether canned sequences of commands from init file in the | |
22401 | current directory have been auto-loaded. | |
22402 | @end table | |
22403 | ||
22404 | @node libthread_db.so.1 file | |
22405 | @subsection Automatically loading thread debugging library | |
22406 | @cindex auto-loading libthread_db.so.1 | |
22407 | ||
22408 | This feature is currently present only on @sc{gnu}/Linux native hosts. | |
22409 | ||
22410 | @value{GDBN} reads in some cases thread debugging library from places specific | |
22411 | to the inferior (@pxref{set libthread-db-search-path}). | |
22412 | ||
22413 | The special @samp{libthread-db-search-path} entry @samp{$sdir} is processed | |
22414 | without checking this @samp{set auto-load libthread-db} switch as system | |
22415 | libraries have to be trusted in general. In all other cases of | |
22416 | @samp{libthread-db-search-path} entries @value{GDBN} checks first if @samp{set | |
22417 | auto-load libthread-db} is enabled before trying to open such thread debugging | |
22418 | library. | |
22419 | ||
c1668e4e JK |
22420 | Note that loading of this debugging library also requires accordingly configured |
22421 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
22422 | ||
bf88dd68 JK |
22423 | @table @code |
22424 | @anchor{set auto-load libthread-db} | |
22425 | @kindex set auto-load libthread-db | |
22426 | @item set auto-load libthread-db [on|off] | |
22427 | Enable or disable the auto-loading of inferior specific thread debugging library. | |
22428 | ||
22429 | @anchor{show auto-load libthread-db} | |
22430 | @kindex show auto-load libthread-db | |
22431 | @item show auto-load libthread-db | |
22432 | Show whether auto-loading of inferior specific thread debugging library is | |
22433 | enabled or disabled. | |
22434 | ||
22435 | @anchor{info auto-load libthread-db} | |
22436 | @kindex info auto-load libthread-db | |
22437 | @item info auto-load libthread-db | |
22438 | Print the list of all loaded inferior specific thread debugging libraries and | |
22439 | for each such library print list of inferior @var{pid}s using it. | |
22440 | @end table | |
22441 | ||
bccbefd2 JK |
22442 | @node Auto-loading safe path |
22443 | @subsection Security restriction for auto-loading | |
22444 | @cindex auto-loading safe-path | |
22445 | ||
22446 | As the files of inferior can come from untrusted source (such as submitted by | |
22447 | an application user) @value{GDBN} does not always load any files automatically. | |
22448 | @value{GDBN} provides the @samp{set auto-load safe-path} setting to list | |
22449 | directories trusted for loading files not explicitly requested by user. | |
202cbf1c | 22450 | Each directory can also be a shell wildcard pattern. |
bccbefd2 JK |
22451 | |
22452 | If the path is not set properly you will see a warning and the file will not | |
22453 | get loaded: | |
22454 | ||
22455 | @smallexample | |
22456 | $ ./gdb -q ./gdb | |
22457 | Reading symbols from /home/user/gdb/gdb...done. | |
22458 | warning: File "/home/user/gdb/gdb-gdb.gdb" auto-loading has been | |
1564a261 JK |
22459 | declined by your `auto-load safe-path' set |
22460 | to "$debugdir:$datadir/auto-load". | |
bccbefd2 | 22461 | warning: File "/home/user/gdb/gdb-gdb.py" auto-loading has been |
1564a261 JK |
22462 | declined by your `auto-load safe-path' set |
22463 | to "$debugdir:$datadir/auto-load". | |
bccbefd2 JK |
22464 | @end smallexample |
22465 | ||
2c91021c JK |
22466 | @noindent |
22467 | To instruct @value{GDBN} to go ahead and use the init files anyway, | |
22468 | invoke @value{GDBN} like this: | |
22469 | ||
22470 | @smallexample | |
22471 | $ gdb -q -iex "set auto-load safe-path /home/user/gdb" ./gdb | |
22472 | @end smallexample | |
22473 | ||
bccbefd2 JK |
22474 | The list of trusted directories is controlled by the following commands: |
22475 | ||
22476 | @table @code | |
22477 | @anchor{set auto-load safe-path} | |
22478 | @kindex set auto-load safe-path | |
af2c1515 | 22479 | @item set auto-load safe-path @r{[}@var{directories}@r{]} |
bccbefd2 JK |
22480 | Set the list of directories (and their subdirectories) trusted for automatic |
22481 | loading and execution of scripts. You can also enter a specific trusted file. | |
202cbf1c JK |
22482 | Each directory can also be a shell wildcard pattern; wildcards do not match |
22483 | directory separator - see @code{FNM_PATHNAME} for system function @code{fnmatch} | |
22484 | (@pxref{Wildcard Matching, fnmatch, , libc, GNU C Library Reference Manual}). | |
af2c1515 JK |
22485 | If you omit @var{directories}, @samp{auto-load safe-path} will be reset to |
22486 | its default value as specified during @value{GDBN} compilation. | |
22487 | ||
d9242c17 | 22488 | The list of directories uses path separator (@samp{:} on GNU and Unix |
bccbefd2 JK |
22489 | systems, @samp{;} on MS-Windows and MS-DOS) to separate directories, similarly |
22490 | to the @env{PATH} environment variable. | |
22491 | ||
22492 | @anchor{show auto-load safe-path} | |
22493 | @kindex show auto-load safe-path | |
22494 | @item show auto-load safe-path | |
22495 | Show the list of directories trusted for automatic loading and execution of | |
22496 | scripts. | |
22497 | ||
22498 | @anchor{add-auto-load-safe-path} | |
22499 | @kindex add-auto-load-safe-path | |
22500 | @item add-auto-load-safe-path | |
22501 | Add an entry (or list of entries) the list of directories trusted for automatic | |
22502 | loading and execution of scripts. Multiple entries may be delimited by the | |
d9242c17 | 22503 | host platform path separator in use. |
bccbefd2 JK |
22504 | @end table |
22505 | ||
7349ff92 | 22506 | This variable defaults to what @code{--with-auto-load-dir} has been configured |
1564a261 JK |
22507 | to (@pxref{with-auto-load-dir}). @file{$debugdir} and @file{$datadir} |
22508 | substitution applies the same as for @ref{set auto-load scripts-directory}. | |
22509 | The default @code{set auto-load safe-path} value can be also overriden by | |
22510 | @value{GDBN} configuration option @option{--with-auto-load-safe-path}. | |
6dea1fbd | 22511 | |
6dea1fbd JK |
22512 | Setting this variable to @file{/} disables this security protection, |
22513 | corresponding @value{GDBN} configuration option is | |
22514 | @option{--without-auto-load-safe-path}. | |
bccbefd2 JK |
22515 | This variable is supposed to be set to the system directories writable by the |
22516 | system superuser only. Users can add their source directories in init files in | |
22517 | their home directories (@pxref{Home Directory Init File}). See also deprecated | |
22518 | init file in the current directory | |
22519 | (@pxref{Init File in the Current Directory during Startup}). | |
22520 | ||
22521 | To force @value{GDBN} to load the files it declined to load in the previous | |
22522 | example, you could use one of the following ways: | |
22523 | ||
0511cc75 JK |
22524 | @table @asis |
22525 | @item @file{~/.gdbinit}: @samp{add-auto-load-safe-path ~/src/gdb} | |
bccbefd2 JK |
22526 | Specify this trusted directory (or a file) as additional component of the list. |
22527 | You have to specify also any existing directories displayed by | |
22528 | by @samp{show auto-load safe-path} (such as @samp{/usr:/bin} in this example). | |
22529 | ||
174bb630 | 22530 | @item @kbd{gdb -iex "set auto-load safe-path /usr:/bin:~/src/gdb" @dots{}} |
bccbefd2 JK |
22531 | Specify this directory as in the previous case but just for a single |
22532 | @value{GDBN} session. | |
22533 | ||
af2c1515 | 22534 | @item @kbd{gdb -iex "set auto-load safe-path /" @dots{}} |
bccbefd2 JK |
22535 | Disable auto-loading safety for a single @value{GDBN} session. |
22536 | This assumes all the files you debug during this @value{GDBN} session will come | |
22537 | from trusted sources. | |
22538 | ||
22539 | @item @kbd{./configure --without-auto-load-safe-path} | |
22540 | During compilation of @value{GDBN} you may disable any auto-loading safety. | |
22541 | This assumes all the files you will ever debug with this @value{GDBN} come from | |
22542 | trusted sources. | |
0511cc75 | 22543 | @end table |
bccbefd2 JK |
22544 | |
22545 | On the other hand you can also explicitly forbid automatic files loading which | |
22546 | also suppresses any such warning messages: | |
22547 | ||
0511cc75 | 22548 | @table @asis |
174bb630 | 22549 | @item @kbd{gdb -iex "set auto-load no" @dots{}} |
bccbefd2 JK |
22550 | You can use @value{GDBN} command-line option for a single @value{GDBN} session. |
22551 | ||
0511cc75 | 22552 | @item @file{~/.gdbinit}: @samp{set auto-load no} |
bccbefd2 JK |
22553 | Disable auto-loading globally for the user |
22554 | (@pxref{Home Directory Init File}). While it is improbable, you could also | |
22555 | use system init file instead (@pxref{System-wide configuration}). | |
0511cc75 | 22556 | @end table |
bccbefd2 JK |
22557 | |
22558 | This setting applies to the file names as entered by user. If no entry matches | |
22559 | @value{GDBN} tries as a last resort to also resolve all the file names into | |
22560 | their canonical form (typically resolving symbolic links) and compare the | |
22561 | entries again. @value{GDBN} already canonicalizes most of the filenames on its | |
22562 | own before starting the comparison so a canonical form of directories is | |
22563 | recommended to be entered. | |
22564 | ||
4dc84fd1 JK |
22565 | @node Auto-loading verbose mode |
22566 | @subsection Displaying files tried for auto-load | |
22567 | @cindex auto-loading verbose mode | |
22568 | ||
22569 | For better visibility of all the file locations where you can place scripts to | |
22570 | be auto-loaded with inferior --- or to protect yourself against accidental | |
22571 | execution of untrusted scripts --- @value{GDBN} provides a feature for printing | |
22572 | all the files attempted to be loaded. Both existing and non-existing files may | |
22573 | be printed. | |
22574 | ||
22575 | For example the list of directories from which it is safe to auto-load files | |
22576 | (@pxref{Auto-loading safe path}) applies also to canonicalized filenames which | |
22577 | may not be too obvious while setting it up. | |
22578 | ||
22579 | @smallexample | |
0070f25a | 22580 | (gdb) set debug auto-load on |
4dc84fd1 JK |
22581 | (gdb) file ~/src/t/true |
22582 | auto-load: Loading canned sequences of commands script "/tmp/true-gdb.gdb" | |
22583 | for objfile "/tmp/true". | |
22584 | auto-load: Updating directories of "/usr:/opt". | |
22585 | auto-load: Using directory "/usr". | |
22586 | auto-load: Using directory "/opt". | |
22587 | warning: File "/tmp/true-gdb.gdb" auto-loading has been declined | |
22588 | by your `auto-load safe-path' set to "/usr:/opt". | |
22589 | @end smallexample | |
22590 | ||
22591 | @table @code | |
22592 | @anchor{set debug auto-load} | |
22593 | @kindex set debug auto-load | |
22594 | @item set debug auto-load [on|off] | |
22595 | Set whether to print the filenames attempted to be auto-loaded. | |
22596 | ||
22597 | @anchor{show debug auto-load} | |
22598 | @kindex show debug auto-load | |
22599 | @item show debug auto-load | |
22600 | Show whether printing of the filenames attempted to be auto-loaded is turned | |
22601 | on or off. | |
22602 | @end table | |
22603 | ||
8e04817f | 22604 | @node Messages/Warnings |
79a6e687 | 22605 | @section Optional Warnings and Messages |
104c1213 | 22606 | |
9c16f35a EZ |
22607 | @cindex verbose operation |
22608 | @cindex optional warnings | |
8e04817f AC |
22609 | By default, @value{GDBN} is silent about its inner workings. If you are |
22610 | running on a slow machine, you may want to use the @code{set verbose} | |
22611 | command. This makes @value{GDBN} tell you when it does a lengthy | |
22612 | internal operation, so you will not think it has crashed. | |
104c1213 | 22613 | |
8e04817f AC |
22614 | Currently, the messages controlled by @code{set verbose} are those |
22615 | which announce that the symbol table for a source file is being read; | |
79a6e687 | 22616 | see @code{symbol-file} in @ref{Files, ,Commands to Specify Files}. |
104c1213 | 22617 | |
8e04817f AC |
22618 | @table @code |
22619 | @kindex set verbose | |
22620 | @item set verbose on | |
22621 | Enables @value{GDBN} output of certain informational messages. | |
104c1213 | 22622 | |
8e04817f AC |
22623 | @item set verbose off |
22624 | Disables @value{GDBN} output of certain informational messages. | |
104c1213 | 22625 | |
8e04817f AC |
22626 | @kindex show verbose |
22627 | @item show verbose | |
22628 | Displays whether @code{set verbose} is on or off. | |
22629 | @end table | |
104c1213 | 22630 | |
8e04817f AC |
22631 | By default, if @value{GDBN} encounters bugs in the symbol table of an |
22632 | object file, it is silent; but if you are debugging a compiler, you may | |
79a6e687 BW |
22633 | find this information useful (@pxref{Symbol Errors, ,Errors Reading |
22634 | Symbol Files}). | |
104c1213 | 22635 | |
8e04817f | 22636 | @table @code |
104c1213 | 22637 | |
8e04817f AC |
22638 | @kindex set complaints |
22639 | @item set complaints @var{limit} | |
22640 | Permits @value{GDBN} to output @var{limit} complaints about each type of | |
22641 | unusual symbols before becoming silent about the problem. Set | |
22642 | @var{limit} to zero to suppress all complaints; set it to a large number | |
22643 | to prevent complaints from being suppressed. | |
104c1213 | 22644 | |
8e04817f AC |
22645 | @kindex show complaints |
22646 | @item show complaints | |
22647 | Displays how many symbol complaints @value{GDBN} is permitted to produce. | |
104c1213 | 22648 | |
8e04817f | 22649 | @end table |
104c1213 | 22650 | |
d837706a | 22651 | @anchor{confirmation requests} |
8e04817f AC |
22652 | By default, @value{GDBN} is cautious, and asks what sometimes seems to be a |
22653 | lot of stupid questions to confirm certain commands. For example, if | |
22654 | you try to run a program which is already running: | |
104c1213 | 22655 | |
474c8240 | 22656 | @smallexample |
8e04817f AC |
22657 | (@value{GDBP}) run |
22658 | The program being debugged has been started already. | |
22659 | Start it from the beginning? (y or n) | |
474c8240 | 22660 | @end smallexample |
104c1213 | 22661 | |
8e04817f AC |
22662 | If you are willing to unflinchingly face the consequences of your own |
22663 | commands, you can disable this ``feature'': | |
104c1213 | 22664 | |
8e04817f | 22665 | @table @code |
104c1213 | 22666 | |
8e04817f AC |
22667 | @kindex set confirm |
22668 | @cindex flinching | |
22669 | @cindex confirmation | |
22670 | @cindex stupid questions | |
22671 | @item set confirm off | |
7c953934 TT |
22672 | Disables confirmation requests. Note that running @value{GDBN} with |
22673 | the @option{--batch} option (@pxref{Mode Options, -batch}) also | |
22674 | automatically disables confirmation requests. | |
104c1213 | 22675 | |
8e04817f AC |
22676 | @item set confirm on |
22677 | Enables confirmation requests (the default). | |
104c1213 | 22678 | |
8e04817f AC |
22679 | @kindex show confirm |
22680 | @item show confirm | |
22681 | Displays state of confirmation requests. | |
22682 | ||
22683 | @end table | |
104c1213 | 22684 | |
16026cd7 AS |
22685 | @cindex command tracing |
22686 | If you need to debug user-defined commands or sourced files you may find it | |
22687 | useful to enable @dfn{command tracing}. In this mode each command will be | |
22688 | printed as it is executed, prefixed with one or more @samp{+} symbols, the | |
22689 | quantity denoting the call depth of each command. | |
22690 | ||
22691 | @table @code | |
22692 | @kindex set trace-commands | |
22693 | @cindex command scripts, debugging | |
22694 | @item set trace-commands on | |
22695 | Enable command tracing. | |
22696 | @item set trace-commands off | |
22697 | Disable command tracing. | |
22698 | @item show trace-commands | |
22699 | Display the current state of command tracing. | |
22700 | @end table | |
22701 | ||
8e04817f | 22702 | @node Debugging Output |
79a6e687 | 22703 | @section Optional Messages about Internal Happenings |
4644b6e3 EZ |
22704 | @cindex optional debugging messages |
22705 | ||
da316a69 EZ |
22706 | @value{GDBN} has commands that enable optional debugging messages from |
22707 | various @value{GDBN} subsystems; normally these commands are of | |
22708 | interest to @value{GDBN} maintainers, or when reporting a bug. This | |
22709 | section documents those commands. | |
22710 | ||
104c1213 | 22711 | @table @code |
a8f24a35 EZ |
22712 | @kindex set exec-done-display |
22713 | @item set exec-done-display | |
22714 | Turns on or off the notification of asynchronous commands' | |
22715 | completion. When on, @value{GDBN} will print a message when an | |
22716 | asynchronous command finishes its execution. The default is off. | |
22717 | @kindex show exec-done-display | |
22718 | @item show exec-done-display | |
22719 | Displays the current setting of asynchronous command completion | |
22720 | notification. | |
4644b6e3 | 22721 | @kindex set debug |
be9a8770 PA |
22722 | @cindex ARM AArch64 |
22723 | @item set debug aarch64 | |
22724 | Turns on or off display of debugging messages related to ARM AArch64. | |
22725 | The default is off. | |
22726 | @kindex show debug | |
22727 | @item show debug aarch64 | |
22728 | Displays the current state of displaying debugging messages related to | |
22729 | ARM AArch64. | |
4644b6e3 | 22730 | @cindex gdbarch debugging info |
a8f24a35 | 22731 | @cindex architecture debugging info |
8e04817f | 22732 | @item set debug arch |
a8f24a35 | 22733 | Turns on or off display of gdbarch debugging info. The default is off |
8e04817f AC |
22734 | @item show debug arch |
22735 | Displays the current state of displaying gdbarch debugging info. | |
9a005eb9 JB |
22736 | @item set debug aix-solib |
22737 | @cindex AIX shared library debugging | |
22738 | Control display of debugging messages from the AIX shared library | |
22739 | support module. The default is off. | |
22740 | @item show debug aix-thread | |
22741 | Show the current state of displaying AIX shared library debugging messages. | |
721c2651 EZ |
22742 | @item set debug aix-thread |
22743 | @cindex AIX threads | |
22744 | Display debugging messages about inner workings of the AIX thread | |
22745 | module. | |
22746 | @item show debug aix-thread | |
22747 | Show the current state of AIX thread debugging info display. | |
900e11f9 JK |
22748 | @item set debug check-physname |
22749 | @cindex physname | |
22750 | Check the results of the ``physname'' computation. When reading DWARF | |
22751 | debugging information for C@t{++}, @value{GDBN} attempts to compute | |
22752 | each entity's name. @value{GDBN} can do this computation in two | |
22753 | different ways, depending on exactly what information is present. | |
22754 | When enabled, this setting causes @value{GDBN} to compute the names | |
22755 | both ways and display any discrepancies. | |
22756 | @item show debug check-physname | |
22757 | Show the current state of ``physname'' checking. | |
be9a8770 PA |
22758 | @item set debug coff-pe-read |
22759 | @cindex COFF/PE exported symbols | |
22760 | Control display of debugging messages related to reading of COFF/PE | |
22761 | exported symbols. The default is off. | |
22762 | @item show debug coff-pe-read | |
22763 | Displays the current state of displaying debugging messages related to | |
22764 | reading of COFF/PE exported symbols. | |
d97bc12b DE |
22765 | @item set debug dwarf2-die |
22766 | @cindex DWARF2 DIEs | |
22767 | Dump DWARF2 DIEs after they are read in. | |
22768 | The value is the number of nesting levels to print. | |
22769 | A value of zero turns off the display. | |
22770 | @item show debug dwarf2-die | |
22771 | Show the current state of DWARF2 DIE debugging. | |
45cfd468 DE |
22772 | @item set debug dwarf2-read |
22773 | @cindex DWARF2 Reading | |
22774 | Turns on or off display of debugging messages related to reading | |
73be47f5 DE |
22775 | DWARF debug info. The default is 0 (off). |
22776 | A value of 1 provides basic information. | |
22777 | A value greater than 1 provides more verbose information. | |
45cfd468 DE |
22778 | @item show debug dwarf2-read |
22779 | Show the current state of DWARF2 reader debugging. | |
237fc4c9 PA |
22780 | @item set debug displaced |
22781 | @cindex displaced stepping debugging info | |
22782 | Turns on or off display of @value{GDBN} debugging info for the | |
22783 | displaced stepping support. The default is off. | |
22784 | @item show debug displaced | |
22785 | Displays the current state of displaying @value{GDBN} debugging info | |
22786 | related to displaced stepping. | |
8e04817f | 22787 | @item set debug event |
4644b6e3 | 22788 | @cindex event debugging info |
a8f24a35 | 22789 | Turns on or off display of @value{GDBN} event debugging info. The |
8e04817f | 22790 | default is off. |
8e04817f AC |
22791 | @item show debug event |
22792 | Displays the current state of displaying @value{GDBN} event debugging | |
22793 | info. | |
8e04817f | 22794 | @item set debug expression |
4644b6e3 | 22795 | @cindex expression debugging info |
721c2651 EZ |
22796 | Turns on or off display of debugging info about @value{GDBN} |
22797 | expression parsing. The default is off. | |
8e04817f | 22798 | @item show debug expression |
721c2651 EZ |
22799 | Displays the current state of displaying debugging info about |
22800 | @value{GDBN} expression parsing. | |
7453dc06 | 22801 | @item set debug frame |
4644b6e3 | 22802 | @cindex frame debugging info |
7453dc06 AC |
22803 | Turns on or off display of @value{GDBN} frame debugging info. The |
22804 | default is off. | |
7453dc06 AC |
22805 | @item show debug frame |
22806 | Displays the current state of displaying @value{GDBN} frame debugging | |
22807 | info. | |
cbe54154 PA |
22808 | @item set debug gnu-nat |
22809 | @cindex @sc{gnu}/Hurd debug messages | |
22810 | Turns on or off debugging messages from the @sc{gnu}/Hurd debug support. | |
22811 | @item show debug gnu-nat | |
22812 | Show the current state of @sc{gnu}/Hurd debugging messages. | |
30e91e0b RC |
22813 | @item set debug infrun |
22814 | @cindex inferior debugging info | |
22815 | Turns on or off display of @value{GDBN} debugging info for running the inferior. | |
22816 | The default is off. @file{infrun.c} contains GDB's runtime state machine used | |
22817 | for implementing operations such as single-stepping the inferior. | |
22818 | @item show debug infrun | |
22819 | Displays the current state of @value{GDBN} inferior debugging. | |
a255712f PP |
22820 | @item set debug jit |
22821 | @cindex just-in-time compilation, debugging messages | |
22822 | Turns on or off debugging messages from JIT debug support. | |
22823 | @item show debug jit | |
22824 | Displays the current state of @value{GDBN} JIT debugging. | |
da316a69 EZ |
22825 | @item set debug lin-lwp |
22826 | @cindex @sc{gnu}/Linux LWP debug messages | |
22827 | @cindex Linux lightweight processes | |
721c2651 | 22828 | Turns on or off debugging messages from the Linux LWP debug support. |
da316a69 EZ |
22829 | @item show debug lin-lwp |
22830 | Show the current state of Linux LWP debugging messages. | |
be9a8770 PA |
22831 | @item set debug mach-o |
22832 | @cindex Mach-O symbols processing | |
22833 | Control display of debugging messages related to Mach-O symbols | |
22834 | processing. The default is off. | |
22835 | @item show debug mach-o | |
22836 | Displays the current state of displaying debugging messages related to | |
22837 | reading of COFF/PE exported symbols. | |
c9b6281a YQ |
22838 | @item set debug notification |
22839 | @cindex remote async notification debugging info | |
22840 | Turns on or off debugging messages about remote async notification. | |
22841 | The default is off. | |
22842 | @item show debug notification | |
22843 | Displays the current state of remote async notification debugging messages. | |
2b4855ab | 22844 | @item set debug observer |
4644b6e3 | 22845 | @cindex observer debugging info |
2b4855ab AC |
22846 | Turns on or off display of @value{GDBN} observer debugging. This |
22847 | includes info such as the notification of observable events. | |
2b4855ab AC |
22848 | @item show debug observer |
22849 | Displays the current state of observer debugging. | |
8e04817f | 22850 | @item set debug overload |
4644b6e3 | 22851 | @cindex C@t{++} overload debugging info |
8e04817f | 22852 | Turns on or off display of @value{GDBN} C@t{++} overload debugging |
359df76b | 22853 | info. This includes info such as ranking of functions, etc. The default |
8e04817f | 22854 | is off. |
8e04817f AC |
22855 | @item show debug overload |
22856 | Displays the current state of displaying @value{GDBN} C@t{++} overload | |
22857 | debugging info. | |
92981e24 TT |
22858 | @cindex expression parser, debugging info |
22859 | @cindex debug expression parser | |
22860 | @item set debug parser | |
22861 | Turns on or off the display of expression parser debugging output. | |
22862 | Internally, this sets the @code{yydebug} variable in the expression | |
22863 | parser. @xref{Tracing, , Tracing Your Parser, bison, Bison}, for | |
22864 | details. The default is off. | |
22865 | @item show debug parser | |
22866 | Show the current state of expression parser debugging. | |
8e04817f AC |
22867 | @cindex packets, reporting on stdout |
22868 | @cindex serial connections, debugging | |
605a56cb DJ |
22869 | @cindex debug remote protocol |
22870 | @cindex remote protocol debugging | |
22871 | @cindex display remote packets | |
8e04817f AC |
22872 | @item set debug remote |
22873 | Turns on or off display of reports on all packets sent back and forth across | |
22874 | the serial line to the remote machine. The info is printed on the | |
22875 | @value{GDBN} standard output stream. The default is off. | |
8e04817f AC |
22876 | @item show debug remote |
22877 | Displays the state of display of remote packets. | |
8e04817f AC |
22878 | @item set debug serial |
22879 | Turns on or off display of @value{GDBN} serial debugging info. The | |
22880 | default is off. | |
8e04817f AC |
22881 | @item show debug serial |
22882 | Displays the current state of displaying @value{GDBN} serial debugging | |
22883 | info. | |
c45da7e6 EZ |
22884 | @item set debug solib-frv |
22885 | @cindex FR-V shared-library debugging | |
22886 | Turns on or off debugging messages for FR-V shared-library code. | |
22887 | @item show debug solib-frv | |
22888 | Display the current state of FR-V shared-library code debugging | |
22889 | messages. | |
8fb8eb5c DE |
22890 | @item set debug symfile |
22891 | @cindex symbol file functions | |
22892 | Turns on or off display of debugging messages related to symbol file functions. | |
22893 | The default is off. @xref{Files}. | |
22894 | @item show debug symfile | |
22895 | Show the current state of symbol file debugging messages. | |
45cfd468 DE |
22896 | @item set debug symtab-create |
22897 | @cindex symbol table creation | |
22898 | Turns on or off display of debugging messages related to symbol table creation. | |
db0fec5c DE |
22899 | The default is 0 (off). |
22900 | A value of 1 provides basic information. | |
22901 | A value greater than 1 provides more verbose information. | |
45cfd468 DE |
22902 | @item show debug symtab-create |
22903 | Show the current state of symbol table creation debugging. | |
8e04817f | 22904 | @item set debug target |
4644b6e3 | 22905 | @cindex target debugging info |
8e04817f AC |
22906 | Turns on or off display of @value{GDBN} target debugging info. This info |
22907 | includes what is going on at the target level of GDB, as it happens. The | |
701b08bb | 22908 | default is 0. Set it to 1 to track events, and to 2 to also track the |
3cecbbbe | 22909 | value of large memory transfers. |
8e04817f AC |
22910 | @item show debug target |
22911 | Displays the current state of displaying @value{GDBN} target debugging | |
22912 | info. | |
75feb17d DJ |
22913 | @item set debug timestamp |
22914 | @cindex timestampping debugging info | |
22915 | Turns on or off display of timestamps with @value{GDBN} debugging info. | |
22916 | When enabled, seconds and microseconds are displayed before each debugging | |
22917 | message. | |
22918 | @item show debug timestamp | |
22919 | Displays the current state of displaying timestamps with @value{GDBN} | |
22920 | debugging info. | |
f989a1c8 | 22921 | @item set debug varobj |
4644b6e3 | 22922 | @cindex variable object debugging info |
8e04817f AC |
22923 | Turns on or off display of @value{GDBN} variable object debugging |
22924 | info. The default is off. | |
f989a1c8 | 22925 | @item show debug varobj |
8e04817f AC |
22926 | Displays the current state of displaying @value{GDBN} variable object |
22927 | debugging info. | |
e776119f DJ |
22928 | @item set debug xml |
22929 | @cindex XML parser debugging | |
22930 | Turns on or off debugging messages for built-in XML parsers. | |
22931 | @item show debug xml | |
22932 | Displays the current state of XML debugging messages. | |
8e04817f | 22933 | @end table |
104c1213 | 22934 | |
14fb1bac JB |
22935 | @node Other Misc Settings |
22936 | @section Other Miscellaneous Settings | |
22937 | @cindex miscellaneous settings | |
22938 | ||
22939 | @table @code | |
22940 | @kindex set interactive-mode | |
22941 | @item set interactive-mode | |
7bfc9434 JB |
22942 | If @code{on}, forces @value{GDBN} to assume that GDB was started |
22943 | in a terminal. In practice, this means that @value{GDBN} should wait | |
22944 | for the user to answer queries generated by commands entered at | |
22945 | the command prompt. If @code{off}, forces @value{GDBN} to operate | |
22946 | in the opposite mode, and it uses the default answers to all queries. | |
22947 | If @code{auto} (the default), @value{GDBN} tries to determine whether | |
22948 | its standard input is a terminal, and works in interactive-mode if it | |
22949 | is, non-interactively otherwise. | |
14fb1bac JB |
22950 | |
22951 | In the vast majority of cases, the debugger should be able to guess | |
22952 | correctly which mode should be used. But this setting can be useful | |
22953 | in certain specific cases, such as running a MinGW @value{GDBN} | |
22954 | inside a cygwin window. | |
22955 | ||
22956 | @kindex show interactive-mode | |
22957 | @item show interactive-mode | |
22958 | Displays whether the debugger is operating in interactive mode or not. | |
22959 | @end table | |
22960 | ||
d57a3c85 TJB |
22961 | @node Extending GDB |
22962 | @chapter Extending @value{GDBN} | |
22963 | @cindex extending GDB | |
22964 | ||
71b8c845 DE |
22965 | @value{GDBN} provides several mechanisms for extension. |
22966 | @value{GDBN} also provides the ability to automatically load | |
22967 | extensions when it reads a file for debugging. This allows the | |
22968 | user to automatically customize @value{GDBN} for the program | |
22969 | being debugged. | |
d57a3c85 | 22970 | |
71b8c845 DE |
22971 | @menu |
22972 | * Sequences:: Canned Sequences of @value{GDBN} Commands | |
22973 | * Python:: Extending @value{GDBN} using Python | |
ed3ef339 | 22974 | * Guile:: Extending @value{GDBN} using Guile |
71b8c845 | 22975 | * Auto-loading extensions:: Automatically loading extensions |
ed3ef339 | 22976 | * Multiple Extension Languages:: Working with multiple extension languages |
71b8c845 DE |
22977 | * Aliases:: Creating new spellings of existing commands |
22978 | @end menu | |
22979 | ||
22980 | To facilitate the use of extension languages, @value{GDBN} is capable | |
95433b34 | 22981 | of evaluating the contents of a file. When doing so, @value{GDBN} |
71b8c845 | 22982 | can recognize which extension language is being used by looking at |
95433b34 JB |
22983 | the filename extension. Files with an unrecognized filename extension |
22984 | are always treated as a @value{GDBN} Command Files. | |
22985 | @xref{Command Files,, Command files}. | |
22986 | ||
22987 | You can control how @value{GDBN} evaluates these files with the following | |
22988 | setting: | |
22989 | ||
22990 | @table @code | |
22991 | @kindex set script-extension | |
22992 | @kindex show script-extension | |
22993 | @item set script-extension off | |
22994 | All scripts are always evaluated as @value{GDBN} Command Files. | |
22995 | ||
22996 | @item set script-extension soft | |
22997 | The debugger determines the scripting language based on filename | |
22998 | extension. If this scripting language is supported, @value{GDBN} | |
22999 | evaluates the script using that language. Otherwise, it evaluates | |
23000 | the file as a @value{GDBN} Command File. | |
23001 | ||
23002 | @item set script-extension strict | |
23003 | The debugger determines the scripting language based on filename | |
23004 | extension, and evaluates the script using that language. If the | |
23005 | language is not supported, then the evaluation fails. | |
23006 | ||
23007 | @item show script-extension | |
23008 | Display the current value of the @code{script-extension} option. | |
23009 | ||
23010 | @end table | |
23011 | ||
8e04817f | 23012 | @node Sequences |
d57a3c85 | 23013 | @section Canned Sequences of Commands |
104c1213 | 23014 | |
8e04817f | 23015 | Aside from breakpoint commands (@pxref{Break Commands, ,Breakpoint |
79a6e687 | 23016 | Command Lists}), @value{GDBN} provides two ways to store sequences of |
8e04817f AC |
23017 | commands for execution as a unit: user-defined commands and command |
23018 | files. | |
104c1213 | 23019 | |
8e04817f | 23020 | @menu |
fcc73fe3 EZ |
23021 | * Define:: How to define your own commands |
23022 | * Hooks:: Hooks for user-defined commands | |
23023 | * Command Files:: How to write scripts of commands to be stored in a file | |
23024 | * Output:: Commands for controlled output | |
71b8c845 | 23025 | * Auto-loading sequences:: Controlling auto-loaded command files |
8e04817f | 23026 | @end menu |
104c1213 | 23027 | |
8e04817f | 23028 | @node Define |
d57a3c85 | 23029 | @subsection User-defined Commands |
104c1213 | 23030 | |
8e04817f | 23031 | @cindex user-defined command |
fcc73fe3 | 23032 | @cindex arguments, to user-defined commands |
8e04817f AC |
23033 | A @dfn{user-defined command} is a sequence of @value{GDBN} commands to |
23034 | which you assign a new name as a command. This is done with the | |
23035 | @code{define} command. User commands may accept up to 10 arguments | |
23036 | separated by whitespace. Arguments are accessed within the user command | |
c03c782f | 23037 | via @code{$arg0@dots{}$arg9}. A trivial example: |
104c1213 | 23038 | |
8e04817f AC |
23039 | @smallexample |
23040 | define adder | |
23041 | print $arg0 + $arg1 + $arg2 | |
c03c782f | 23042 | end |
8e04817f | 23043 | @end smallexample |
104c1213 JM |
23044 | |
23045 | @noindent | |
8e04817f | 23046 | To execute the command use: |
104c1213 | 23047 | |
8e04817f AC |
23048 | @smallexample |
23049 | adder 1 2 3 | |
23050 | @end smallexample | |
104c1213 | 23051 | |
8e04817f AC |
23052 | @noindent |
23053 | This defines the command @code{adder}, which prints the sum of | |
23054 | its three arguments. Note the arguments are text substitutions, so they may | |
23055 | reference variables, use complex expressions, or even perform inferior | |
23056 | functions calls. | |
104c1213 | 23057 | |
fcc73fe3 EZ |
23058 | @cindex argument count in user-defined commands |
23059 | @cindex how many arguments (user-defined commands) | |
c03c782f AS |
23060 | In addition, @code{$argc} may be used to find out how many arguments have |
23061 | been passed. This expands to a number in the range 0@dots{}10. | |
23062 | ||
23063 | @smallexample | |
23064 | define adder | |
23065 | if $argc == 2 | |
23066 | print $arg0 + $arg1 | |
23067 | end | |
23068 | if $argc == 3 | |
23069 | print $arg0 + $arg1 + $arg2 | |
23070 | end | |
23071 | end | |
23072 | @end smallexample | |
23073 | ||
104c1213 | 23074 | @table @code |
104c1213 | 23075 | |
8e04817f AC |
23076 | @kindex define |
23077 | @item define @var{commandname} | |
23078 | Define a command named @var{commandname}. If there is already a command | |
23079 | by that name, you are asked to confirm that you want to redefine it. | |
697aa1b7 | 23080 | The argument @var{commandname} may be a bare command name consisting of letters, |
adb483fe DJ |
23081 | numbers, dashes, and underscores. It may also start with any predefined |
23082 | prefix command. For example, @samp{define target my-target} creates | |
23083 | a user-defined @samp{target my-target} command. | |
104c1213 | 23084 | |
8e04817f AC |
23085 | The definition of the command is made up of other @value{GDBN} command lines, |
23086 | which are given following the @code{define} command. The end of these | |
23087 | commands is marked by a line containing @code{end}. | |
104c1213 | 23088 | |
8e04817f | 23089 | @kindex document |
ca91424e | 23090 | @kindex end@r{ (user-defined commands)} |
8e04817f AC |
23091 | @item document @var{commandname} |
23092 | Document the user-defined command @var{commandname}, so that it can be | |
23093 | accessed by @code{help}. The command @var{commandname} must already be | |
23094 | defined. This command reads lines of documentation just as @code{define} | |
23095 | reads the lines of the command definition, ending with @code{end}. | |
23096 | After the @code{document} command is finished, @code{help} on command | |
23097 | @var{commandname} displays the documentation you have written. | |
104c1213 | 23098 | |
8e04817f AC |
23099 | You may use the @code{document} command again to change the |
23100 | documentation of a command. Redefining the command with @code{define} | |
23101 | does not change the documentation. | |
104c1213 | 23102 | |
c45da7e6 EZ |
23103 | @kindex dont-repeat |
23104 | @cindex don't repeat command | |
23105 | @item dont-repeat | |
23106 | Used inside a user-defined command, this tells @value{GDBN} that this | |
23107 | command should not be repeated when the user hits @key{RET} | |
23108 | (@pxref{Command Syntax, repeat last command}). | |
23109 | ||
8e04817f AC |
23110 | @kindex help user-defined |
23111 | @item help user-defined | |
7d74f244 DE |
23112 | List all user-defined commands and all python commands defined in class |
23113 | COMAND_USER. The first line of the documentation or docstring is | |
23114 | included (if any). | |
104c1213 | 23115 | |
8e04817f AC |
23116 | @kindex show user |
23117 | @item show user | |
23118 | @itemx show user @var{commandname} | |
23119 | Display the @value{GDBN} commands used to define @var{commandname} (but | |
23120 | not its documentation). If no @var{commandname} is given, display the | |
23121 | definitions for all user-defined commands. | |
7d74f244 | 23122 | This does not work for user-defined python commands. |
104c1213 | 23123 | |
fcc73fe3 | 23124 | @cindex infinite recursion in user-defined commands |
20f01a46 DH |
23125 | @kindex show max-user-call-depth |
23126 | @kindex set max-user-call-depth | |
23127 | @item show max-user-call-depth | |
5ca0cb28 DH |
23128 | @itemx set max-user-call-depth |
23129 | The value of @code{max-user-call-depth} controls how many recursion | |
3f94c067 | 23130 | levels are allowed in user-defined commands before @value{GDBN} suspects an |
5ca0cb28 | 23131 | infinite recursion and aborts the command. |
7d74f244 | 23132 | This does not apply to user-defined python commands. |
104c1213 JM |
23133 | @end table |
23134 | ||
fcc73fe3 EZ |
23135 | In addition to the above commands, user-defined commands frequently |
23136 | use control flow commands, described in @ref{Command Files}. | |
23137 | ||
8e04817f AC |
23138 | When user-defined commands are executed, the |
23139 | commands of the definition are not printed. An error in any command | |
23140 | stops execution of the user-defined command. | |
104c1213 | 23141 | |
8e04817f AC |
23142 | If used interactively, commands that would ask for confirmation proceed |
23143 | without asking when used inside a user-defined command. Many @value{GDBN} | |
23144 | commands that normally print messages to say what they are doing omit the | |
23145 | messages when used in a user-defined command. | |
104c1213 | 23146 | |
8e04817f | 23147 | @node Hooks |
d57a3c85 | 23148 | @subsection User-defined Command Hooks |
8e04817f AC |
23149 | @cindex command hooks |
23150 | @cindex hooks, for commands | |
23151 | @cindex hooks, pre-command | |
104c1213 | 23152 | |
8e04817f | 23153 | @kindex hook |
8e04817f AC |
23154 | You may define @dfn{hooks}, which are a special kind of user-defined |
23155 | command. Whenever you run the command @samp{foo}, if the user-defined | |
23156 | command @samp{hook-foo} exists, it is executed (with no arguments) | |
23157 | before that command. | |
104c1213 | 23158 | |
8e04817f AC |
23159 | @cindex hooks, post-command |
23160 | @kindex hookpost | |
8e04817f AC |
23161 | A hook may also be defined which is run after the command you executed. |
23162 | Whenever you run the command @samp{foo}, if the user-defined command | |
23163 | @samp{hookpost-foo} exists, it is executed (with no arguments) after | |
23164 | that command. Post-execution hooks may exist simultaneously with | |
23165 | pre-execution hooks, for the same command. | |
104c1213 | 23166 | |
8e04817f | 23167 | It is valid for a hook to call the command which it hooks. If this |
9f1c6395 | 23168 | occurs, the hook is not re-executed, thereby avoiding infinite recursion. |
104c1213 | 23169 | |
8e04817f AC |
23170 | @c It would be nice if hookpost could be passed a parameter indicating |
23171 | @c if the command it hooks executed properly or not. FIXME! | |
104c1213 | 23172 | |
8e04817f AC |
23173 | @kindex stop@r{, a pseudo-command} |
23174 | In addition, a pseudo-command, @samp{stop} exists. Defining | |
23175 | (@samp{hook-stop}) makes the associated commands execute every time | |
23176 | execution stops in your program: before breakpoint commands are run, | |
23177 | displays are printed, or the stack frame is printed. | |
104c1213 | 23178 | |
8e04817f AC |
23179 | For example, to ignore @code{SIGALRM} signals while |
23180 | single-stepping, but treat them normally during normal execution, | |
23181 | you could define: | |
104c1213 | 23182 | |
474c8240 | 23183 | @smallexample |
8e04817f AC |
23184 | define hook-stop |
23185 | handle SIGALRM nopass | |
23186 | end | |
104c1213 | 23187 | |
8e04817f AC |
23188 | define hook-run |
23189 | handle SIGALRM pass | |
23190 | end | |
104c1213 | 23191 | |
8e04817f | 23192 | define hook-continue |
d3e8051b | 23193 | handle SIGALRM pass |
8e04817f | 23194 | end |
474c8240 | 23195 | @end smallexample |
104c1213 | 23196 | |
d3e8051b | 23197 | As a further example, to hook at the beginning and end of the @code{echo} |
b383017d | 23198 | command, and to add extra text to the beginning and end of the message, |
8e04817f | 23199 | you could define: |
104c1213 | 23200 | |
474c8240 | 23201 | @smallexample |
8e04817f AC |
23202 | define hook-echo |
23203 | echo <<<--- | |
23204 | end | |
104c1213 | 23205 | |
8e04817f AC |
23206 | define hookpost-echo |
23207 | echo --->>>\n | |
23208 | end | |
104c1213 | 23209 | |
8e04817f AC |
23210 | (@value{GDBP}) echo Hello World |
23211 | <<<---Hello World--->>> | |
23212 | (@value{GDBP}) | |
104c1213 | 23213 | |
474c8240 | 23214 | @end smallexample |
104c1213 | 23215 | |
8e04817f AC |
23216 | You can define a hook for any single-word command in @value{GDBN}, but |
23217 | not for command aliases; you should define a hook for the basic command | |
c1468174 | 23218 | name, e.g.@: @code{backtrace} rather than @code{bt}. |
8e04817f AC |
23219 | @c FIXME! So how does Joe User discover whether a command is an alias |
23220 | @c or not? | |
adb483fe DJ |
23221 | You can hook a multi-word command by adding @code{hook-} or |
23222 | @code{hookpost-} to the last word of the command, e.g.@: | |
23223 | @samp{define target hook-remote} to add a hook to @samp{target remote}. | |
23224 | ||
8e04817f AC |
23225 | If an error occurs during the execution of your hook, execution of |
23226 | @value{GDBN} commands stops and @value{GDBN} issues a prompt | |
23227 | (before the command that you actually typed had a chance to run). | |
104c1213 | 23228 | |
8e04817f AC |
23229 | If you try to define a hook which does not match any known command, you |
23230 | get a warning from the @code{define} command. | |
c906108c | 23231 | |
8e04817f | 23232 | @node Command Files |
d57a3c85 | 23233 | @subsection Command Files |
c906108c | 23234 | |
8e04817f | 23235 | @cindex command files |
fcc73fe3 | 23236 | @cindex scripting commands |
6fc08d32 EZ |
23237 | A command file for @value{GDBN} is a text file made of lines that are |
23238 | @value{GDBN} commands. Comments (lines starting with @kbd{#}) may | |
23239 | also be included. An empty line in a command file does nothing; it | |
23240 | does not mean to repeat the last command, as it would from the | |
23241 | terminal. | |
c906108c | 23242 | |
6fc08d32 | 23243 | You can request the execution of a command file with the @code{source} |
95433b34 JB |
23244 | command. Note that the @code{source} command is also used to evaluate |
23245 | scripts that are not Command Files. The exact behavior can be configured | |
23246 | using the @code{script-extension} setting. | |
23247 | @xref{Extending GDB,, Extending GDB}. | |
c906108c | 23248 | |
8e04817f AC |
23249 | @table @code |
23250 | @kindex source | |
ca91424e | 23251 | @cindex execute commands from a file |
3f7b2faa | 23252 | @item source [-s] [-v] @var{filename} |
8e04817f | 23253 | Execute the command file @var{filename}. |
c906108c SS |
23254 | @end table |
23255 | ||
fcc73fe3 EZ |
23256 | The lines in a command file are generally executed sequentially, |
23257 | unless the order of execution is changed by one of the | |
23258 | @emph{flow-control commands} described below. The commands are not | |
a71ec265 DH |
23259 | printed as they are executed. An error in any command terminates |
23260 | execution of the command file and control is returned to the console. | |
c906108c | 23261 | |
08001717 DE |
23262 | @value{GDBN} first searches for @var{filename} in the current directory. |
23263 | If the file is not found there, and @var{filename} does not specify a | |
23264 | directory, then @value{GDBN} also looks for the file on the source search path | |
23265 | (specified with the @samp{directory} command); | |
23266 | except that @file{$cdir} is not searched because the compilation directory | |
23267 | is not relevant to scripts. | |
4b505b12 | 23268 | |
3f7b2faa DE |
23269 | If @code{-s} is specified, then @value{GDBN} searches for @var{filename} |
23270 | on the search path even if @var{filename} specifies a directory. | |
23271 | The search is done by appending @var{filename} to each element of the | |
23272 | search path. So, for example, if @var{filename} is @file{mylib/myscript} | |
23273 | and the search path contains @file{/home/user} then @value{GDBN} will | |
23274 | look for the script @file{/home/user/mylib/myscript}. | |
23275 | The search is also done if @var{filename} is an absolute path. | |
23276 | For example, if @var{filename} is @file{/tmp/myscript} and | |
23277 | the search path contains @file{/home/user} then @value{GDBN} will | |
23278 | look for the script @file{/home/user/tmp/myscript}. | |
23279 | For DOS-like systems, if @var{filename} contains a drive specification, | |
23280 | it is stripped before concatenation. For example, if @var{filename} is | |
23281 | @file{d:myscript} and the search path contains @file{c:/tmp} then @value{GDBN} | |
23282 | will look for the script @file{c:/tmp/myscript}. | |
23283 | ||
16026cd7 AS |
23284 | If @code{-v}, for verbose mode, is given then @value{GDBN} displays |
23285 | each command as it is executed. The option must be given before | |
23286 | @var{filename}, and is interpreted as part of the filename anywhere else. | |
23287 | ||
8e04817f AC |
23288 | Commands that would ask for confirmation if used interactively proceed |
23289 | without asking when used in a command file. Many @value{GDBN} commands that | |
23290 | normally print messages to say what they are doing omit the messages | |
23291 | when called from command files. | |
c906108c | 23292 | |
8e04817f AC |
23293 | @value{GDBN} also accepts command input from standard input. In this |
23294 | mode, normal output goes to standard output and error output goes to | |
23295 | standard error. Errors in a command file supplied on standard input do | |
6fc08d32 | 23296 | not terminate execution of the command file---execution continues with |
8e04817f | 23297 | the next command. |
c906108c | 23298 | |
474c8240 | 23299 | @smallexample |
8e04817f | 23300 | gdb < cmds > log 2>&1 |
474c8240 | 23301 | @end smallexample |
c906108c | 23302 | |
8e04817f AC |
23303 | (The syntax above will vary depending on the shell used.) This example |
23304 | will execute commands from the file @file{cmds}. All output and errors | |
23305 | would be directed to @file{log}. | |
c906108c | 23306 | |
fcc73fe3 EZ |
23307 | Since commands stored on command files tend to be more general than |
23308 | commands typed interactively, they frequently need to deal with | |
23309 | complicated situations, such as different or unexpected values of | |
23310 | variables and symbols, changes in how the program being debugged is | |
23311 | built, etc. @value{GDBN} provides a set of flow-control commands to | |
23312 | deal with these complexities. Using these commands, you can write | |
23313 | complex scripts that loop over data structures, execute commands | |
23314 | conditionally, etc. | |
23315 | ||
23316 | @table @code | |
23317 | @kindex if | |
23318 | @kindex else | |
23319 | @item if | |
23320 | @itemx else | |
23321 | This command allows to include in your script conditionally executed | |
23322 | commands. The @code{if} command takes a single argument, which is an | |
23323 | expression to evaluate. It is followed by a series of commands that | |
23324 | are executed only if the expression is true (its value is nonzero). | |
23325 | There can then optionally be an @code{else} line, followed by a series | |
23326 | of commands that are only executed if the expression was false. The | |
23327 | end of the list is marked by a line containing @code{end}. | |
23328 | ||
23329 | @kindex while | |
23330 | @item while | |
23331 | This command allows to write loops. Its syntax is similar to | |
23332 | @code{if}: the command takes a single argument, which is an expression | |
23333 | to evaluate, and must be followed by the commands to execute, one per | |
23334 | line, terminated by an @code{end}. These commands are called the | |
23335 | @dfn{body} of the loop. The commands in the body of @code{while} are | |
23336 | executed repeatedly as long as the expression evaluates to true. | |
23337 | ||
23338 | @kindex loop_break | |
23339 | @item loop_break | |
23340 | This command exits the @code{while} loop in whose body it is included. | |
23341 | Execution of the script continues after that @code{while}s @code{end} | |
23342 | line. | |
23343 | ||
23344 | @kindex loop_continue | |
23345 | @item loop_continue | |
23346 | This command skips the execution of the rest of the body of commands | |
23347 | in the @code{while} loop in whose body it is included. Execution | |
23348 | branches to the beginning of the @code{while} loop, where it evaluates | |
23349 | the controlling expression. | |
ca91424e EZ |
23350 | |
23351 | @kindex end@r{ (if/else/while commands)} | |
23352 | @item end | |
23353 | Terminate the block of commands that are the body of @code{if}, | |
23354 | @code{else}, or @code{while} flow-control commands. | |
fcc73fe3 EZ |
23355 | @end table |
23356 | ||
23357 | ||
8e04817f | 23358 | @node Output |
d57a3c85 | 23359 | @subsection Commands for Controlled Output |
c906108c | 23360 | |
8e04817f AC |
23361 | During the execution of a command file or a user-defined command, normal |
23362 | @value{GDBN} output is suppressed; the only output that appears is what is | |
23363 | explicitly printed by the commands in the definition. This section | |
23364 | describes three commands useful for generating exactly the output you | |
23365 | want. | |
c906108c SS |
23366 | |
23367 | @table @code | |
8e04817f AC |
23368 | @kindex echo |
23369 | @item echo @var{text} | |
23370 | @c I do not consider backslash-space a standard C escape sequence | |
23371 | @c because it is not in ANSI. | |
23372 | Print @var{text}. Nonprinting characters can be included in | |
23373 | @var{text} using C escape sequences, such as @samp{\n} to print a | |
23374 | newline. @strong{No newline is printed unless you specify one.} | |
23375 | In addition to the standard C escape sequences, a backslash followed | |
23376 | by a space stands for a space. This is useful for displaying a | |
23377 | string with spaces at the beginning or the end, since leading and | |
23378 | trailing spaces are otherwise trimmed from all arguments. | |
23379 | To print @samp{@w{ }and foo =@w{ }}, use the command | |
23380 | @samp{echo \@w{ }and foo = \@w{ }}. | |
c906108c | 23381 | |
8e04817f AC |
23382 | A backslash at the end of @var{text} can be used, as in C, to continue |
23383 | the command onto subsequent lines. For example, | |
c906108c | 23384 | |
474c8240 | 23385 | @smallexample |
8e04817f AC |
23386 | echo This is some text\n\ |
23387 | which is continued\n\ | |
23388 | onto several lines.\n | |
474c8240 | 23389 | @end smallexample |
c906108c | 23390 | |
8e04817f | 23391 | produces the same output as |
c906108c | 23392 | |
474c8240 | 23393 | @smallexample |
8e04817f AC |
23394 | echo This is some text\n |
23395 | echo which is continued\n | |
23396 | echo onto several lines.\n | |
474c8240 | 23397 | @end smallexample |
c906108c | 23398 | |
8e04817f AC |
23399 | @kindex output |
23400 | @item output @var{expression} | |
23401 | Print the value of @var{expression} and nothing but that value: no | |
23402 | newlines, no @samp{$@var{nn} = }. The value is not entered in the | |
23403 | value history either. @xref{Expressions, ,Expressions}, for more information | |
23404 | on expressions. | |
c906108c | 23405 | |
8e04817f AC |
23406 | @item output/@var{fmt} @var{expression} |
23407 | Print the value of @var{expression} in format @var{fmt}. You can use | |
23408 | the same formats as for @code{print}. @xref{Output Formats,,Output | |
79a6e687 | 23409 | Formats}, for more information. |
c906108c | 23410 | |
8e04817f | 23411 | @kindex printf |
82160952 EZ |
23412 | @item printf @var{template}, @var{expressions}@dots{} |
23413 | Print the values of one or more @var{expressions} under the control of | |
23414 | the string @var{template}. To print several values, make | |
23415 | @var{expressions} be a comma-separated list of individual expressions, | |
23416 | which may be either numbers or pointers. Their values are printed as | |
23417 | specified by @var{template}, exactly as a C program would do by | |
23418 | executing the code below: | |
c906108c | 23419 | |
474c8240 | 23420 | @smallexample |
82160952 | 23421 | printf (@var{template}, @var{expressions}@dots{}); |
474c8240 | 23422 | @end smallexample |
c906108c | 23423 | |
82160952 EZ |
23424 | As in @code{C} @code{printf}, ordinary characters in @var{template} |
23425 | are printed verbatim, while @dfn{conversion specification} introduced | |
23426 | by the @samp{%} character cause subsequent @var{expressions} to be | |
23427 | evaluated, their values converted and formatted according to type and | |
23428 | style information encoded in the conversion specifications, and then | |
23429 | printed. | |
23430 | ||
8e04817f | 23431 | For example, you can print two values in hex like this: |
c906108c | 23432 | |
8e04817f AC |
23433 | @smallexample |
23434 | printf "foo, bar-foo = 0x%x, 0x%x\n", foo, bar-foo | |
23435 | @end smallexample | |
c906108c | 23436 | |
82160952 EZ |
23437 | @code{printf} supports all the standard @code{C} conversion |
23438 | specifications, including the flags and modifiers between the @samp{%} | |
23439 | character and the conversion letter, with the following exceptions: | |
23440 | ||
23441 | @itemize @bullet | |
23442 | @item | |
23443 | The argument-ordering modifiers, such as @samp{2$}, are not supported. | |
23444 | ||
23445 | @item | |
23446 | The modifier @samp{*} is not supported for specifying precision or | |
23447 | width. | |
23448 | ||
23449 | @item | |
23450 | The @samp{'} flag (for separation of digits into groups according to | |
23451 | @code{LC_NUMERIC'}) is not supported. | |
23452 | ||
23453 | @item | |
23454 | The type modifiers @samp{hh}, @samp{j}, @samp{t}, and @samp{z} are not | |
23455 | supported. | |
23456 | ||
23457 | @item | |
23458 | The conversion letter @samp{n} (as in @samp{%n}) is not supported. | |
23459 | ||
23460 | @item | |
23461 | The conversion letters @samp{a} and @samp{A} are not supported. | |
23462 | @end itemize | |
23463 | ||
23464 | @noindent | |
23465 | Note that the @samp{ll} type modifier is supported only if the | |
23466 | underlying @code{C} implementation used to build @value{GDBN} supports | |
23467 | the @code{long long int} type, and the @samp{L} type modifier is | |
23468 | supported only if @code{long double} type is available. | |
23469 | ||
23470 | As in @code{C}, @code{printf} supports simple backslash-escape | |
23471 | sequences, such as @code{\n}, @samp{\t}, @samp{\\}, @samp{\"}, | |
23472 | @samp{\a}, and @samp{\f}, that consist of backslash followed by a | |
23473 | single character. Octal and hexadecimal escape sequences are not | |
23474 | supported. | |
1a619819 LM |
23475 | |
23476 | Additionally, @code{printf} supports conversion specifications for DFP | |
0aea4bf3 LM |
23477 | (@dfn{Decimal Floating Point}) types using the following length modifiers |
23478 | together with a floating point specifier. | |
1a619819 LM |
23479 | letters: |
23480 | ||
23481 | @itemize @bullet | |
23482 | @item | |
23483 | @samp{H} for printing @code{Decimal32} types. | |
23484 | ||
23485 | @item | |
23486 | @samp{D} for printing @code{Decimal64} types. | |
23487 | ||
23488 | @item | |
23489 | @samp{DD} for printing @code{Decimal128} types. | |
23490 | @end itemize | |
23491 | ||
23492 | If the underlying @code{C} implementation used to build @value{GDBN} has | |
0aea4bf3 | 23493 | support for the three length modifiers for DFP types, other modifiers |
3b784c4f | 23494 | such as width and precision will also be available for @value{GDBN} to use. |
1a619819 LM |
23495 | |
23496 | In case there is no such @code{C} support, no additional modifiers will be | |
23497 | available and the value will be printed in the standard way. | |
23498 | ||
23499 | Here's an example of printing DFP types using the above conversion letters: | |
23500 | @smallexample | |
0aea4bf3 | 23501 | printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl |
1a619819 LM |
23502 | @end smallexample |
23503 | ||
f1421989 HZ |
23504 | @kindex eval |
23505 | @item eval @var{template}, @var{expressions}@dots{} | |
23506 | Convert the values of one or more @var{expressions} under the control of | |
23507 | the string @var{template} to a command line, and call it. | |
23508 | ||
c906108c SS |
23509 | @end table |
23510 | ||
71b8c845 DE |
23511 | @node Auto-loading sequences |
23512 | @subsection Controlling auto-loading native @value{GDBN} scripts | |
23513 | @cindex native script auto-loading | |
23514 | ||
23515 | When a new object file is read (for example, due to the @code{file} | |
23516 | command, or because the inferior has loaded a shared library), | |
23517 | @value{GDBN} will look for the command file @file{@var{objfile}-gdb.gdb}. | |
23518 | @xref{Auto-loading extensions}. | |
23519 | ||
23520 | Auto-loading can be enabled or disabled, | |
23521 | and the list of auto-loaded scripts can be printed. | |
23522 | ||
23523 | @table @code | |
23524 | @anchor{set auto-load gdb-scripts} | |
23525 | @kindex set auto-load gdb-scripts | |
23526 | @item set auto-load gdb-scripts [on|off] | |
23527 | Enable or disable the auto-loading of canned sequences of commands scripts. | |
23528 | ||
23529 | @anchor{show auto-load gdb-scripts} | |
23530 | @kindex show auto-load gdb-scripts | |
23531 | @item show auto-load gdb-scripts | |
23532 | Show whether auto-loading of canned sequences of commands scripts is enabled or | |
23533 | disabled. | |
23534 | ||
23535 | @anchor{info auto-load gdb-scripts} | |
23536 | @kindex info auto-load gdb-scripts | |
23537 | @cindex print list of auto-loaded canned sequences of commands scripts | |
23538 | @item info auto-load gdb-scripts [@var{regexp}] | |
23539 | Print the list of all canned sequences of commands scripts that @value{GDBN} | |
23540 | auto-loaded. | |
23541 | @end table | |
23542 | ||
23543 | If @var{regexp} is supplied only canned sequences of commands scripts with | |
23544 | matching names are printed. | |
23545 | ||
329baa95 DE |
23546 | @c Python docs live in a separate file. |
23547 | @include python.texi | |
0e3509db | 23548 | |
ed3ef339 DE |
23549 | @c Guile docs live in a separate file. |
23550 | @include guile.texi | |
23551 | ||
71b8c845 DE |
23552 | @node Auto-loading extensions |
23553 | @section Auto-loading extensions | |
23554 | @cindex auto-loading extensions | |
23555 | ||
23556 | @value{GDBN} provides two mechanisms for automatically loading extensions | |
23557 | when a new object file is read (for example, due to the @code{file} | |
23558 | command, or because the inferior has loaded a shared library): | |
23559 | @file{@var{objfile}-gdb.@var{ext}} and the @code{.debug_gdb_scripts} | |
23560 | section of modern file formats like ELF. | |
23561 | ||
23562 | @menu | |
23563 | * objfile-gdb.ext file: objfile-gdbdotext file. The @file{@var{objfile}-gdb.@var{ext}} file | |
23564 | * .debug_gdb_scripts section: dotdebug_gdb_scripts section. The @code{.debug_gdb_scripts} section | |
23565 | * Which flavor to choose?:: | |
23566 | @end menu | |
23567 | ||
23568 | The auto-loading feature is useful for supplying application-specific | |
23569 | debugging commands and features. | |
23570 | ||
23571 | Auto-loading can be enabled or disabled, | |
23572 | and the list of auto-loaded scripts can be printed. | |
23573 | See the @samp{auto-loading} section of each extension language | |
23574 | for more information. | |
23575 | For @value{GDBN} command files see @ref{Auto-loading sequences}. | |
23576 | For Python files see @ref{Python Auto-loading}. | |
23577 | ||
23578 | Note that loading of this script file also requires accordingly configured | |
23579 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
23580 | ||
23581 | @node objfile-gdbdotext file | |
23582 | @subsection The @file{@var{objfile}-gdb.@var{ext}} file | |
23583 | @cindex @file{@var{objfile}-gdb.gdb} | |
23584 | @cindex @file{@var{objfile}-gdb.py} | |
23585 | @cindex @file{@var{objfile}-gdb.scm} | |
23586 | ||
23587 | When a new object file is read, @value{GDBN} looks for a file named | |
23588 | @file{@var{objfile}-gdb.@var{ext}} (we call it @var{script-name} below), | |
23589 | where @var{objfile} is the object file's name and | |
23590 | where @var{ext} is the file extension for the extension language: | |
23591 | ||
23592 | @table @code | |
23593 | @item @file{@var{objfile}-gdb.gdb} | |
23594 | GDB's own command language | |
23595 | @item @file{@var{objfile}-gdb.py} | |
23596 | Python | |
ed3ef339 DE |
23597 | @item @file{@var{objfile}-gdb.scm} |
23598 | Guile | |
71b8c845 DE |
23599 | @end table |
23600 | ||
23601 | @var{script-name} is formed by ensuring that the file name of @var{objfile} | |
23602 | is absolute, following all symlinks, and resolving @code{.} and @code{..} | |
23603 | components, and appending the @file{-gdb.@var{ext}} suffix. | |
23604 | If this file exists and is readable, @value{GDBN} will evaluate it as a | |
23605 | script in the specified extension language. | |
23606 | ||
23607 | If this file does not exist, then @value{GDBN} will look for | |
23608 | @var{script-name} file in all of the directories as specified below. | |
23609 | ||
23610 | Note that loading of these files requires an accordingly configured | |
23611 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
23612 | ||
23613 | For object files using @file{.exe} suffix @value{GDBN} tries to load first the | |
23614 | scripts normally according to its @file{.exe} filename. But if no scripts are | |
23615 | found @value{GDBN} also tries script filenames matching the object file without | |
23616 | its @file{.exe} suffix. This @file{.exe} stripping is case insensitive and it | |
23617 | is attempted on any platform. This makes the script filenames compatible | |
23618 | between Unix and MS-Windows hosts. | |
23619 | ||
23620 | @table @code | |
23621 | @anchor{set auto-load scripts-directory} | |
23622 | @kindex set auto-load scripts-directory | |
23623 | @item set auto-load scripts-directory @r{[}@var{directories}@r{]} | |
23624 | Control @value{GDBN} auto-loaded scripts location. Multiple directory entries | |
23625 | may be delimited by the host platform path separator in use | |
23626 | (@samp{:} on Unix, @samp{;} on MS-Windows and MS-DOS). | |
23627 | ||
23628 | Each entry here needs to be covered also by the security setting | |
23629 | @code{set auto-load safe-path} (@pxref{set auto-load safe-path}). | |
23630 | ||
23631 | @anchor{with-auto-load-dir} | |
23632 | This variable defaults to @file{$debugdir:$datadir/auto-load}. The default | |
23633 | @code{set auto-load safe-path} value can be also overriden by @value{GDBN} | |
23634 | configuration option @option{--with-auto-load-dir}. | |
23635 | ||
23636 | Any reference to @file{$debugdir} will get replaced by | |
23637 | @var{debug-file-directory} value (@pxref{Separate Debug Files}) and any | |
23638 | reference to @file{$datadir} will get replaced by @var{data-directory} which is | |
23639 | determined at @value{GDBN} startup (@pxref{Data Files}). @file{$debugdir} and | |
23640 | @file{$datadir} must be placed as a directory component --- either alone or | |
23641 | delimited by @file{/} or @file{\} directory separators, depending on the host | |
23642 | platform. | |
23643 | ||
23644 | The list of directories uses path separator (@samp{:} on GNU and Unix | |
23645 | systems, @samp{;} on MS-Windows and MS-DOS) to separate directories, similarly | |
23646 | to the @env{PATH} environment variable. | |
23647 | ||
23648 | @anchor{show auto-load scripts-directory} | |
23649 | @kindex show auto-load scripts-directory | |
23650 | @item show auto-load scripts-directory | |
23651 | Show @value{GDBN} auto-loaded scripts location. | |
23652 | @end table | |
23653 | ||
23654 | @value{GDBN} does not track which files it has already auto-loaded this way. | |
23655 | @value{GDBN} will load the associated script every time the corresponding | |
23656 | @var{objfile} is opened. | |
23657 | So your @file{-gdb.@var{ext}} file should be careful to avoid errors if it | |
23658 | is evaluated more than once. | |
23659 | ||
23660 | @node dotdebug_gdb_scripts section | |
23661 | @subsection The @code{.debug_gdb_scripts} section | |
23662 | @cindex @code{.debug_gdb_scripts} section | |
23663 | ||
23664 | For systems using file formats like ELF and COFF, | |
23665 | when @value{GDBN} loads a new object file | |
23666 | it will look for a special section named @code{.debug_gdb_scripts}. | |
23667 | If this section exists, its contents is a list of NUL-terminated names | |
23668 | of scripts to load. Each entry begins with a non-NULL prefix byte that | |
23669 | specifies the kind of entry, typically the extension language. | |
23670 | ||
23671 | @value{GDBN} will look for each specified script file first in the | |
23672 | current directory and then along the source search path | |
23673 | (@pxref{Source Path, ,Specifying Source Directories}), | |
23674 | except that @file{$cdir} is not searched, since the compilation | |
23675 | directory is not relevant to scripts. | |
23676 | ||
23677 | Entries can be placed in section @code{.debug_gdb_scripts} with, | |
23678 | for example, this GCC macro for Python scripts. | |
23679 | ||
23680 | @example | |
23681 | /* Note: The "MS" section flags are to remove duplicates. */ | |
23682 | #define DEFINE_GDB_PY_SCRIPT(script_name) \ | |
23683 | asm("\ | |
23684 | .pushsection \".debug_gdb_scripts\", \"MS\",@@progbits,1\n\ | |
23685 | .byte 1 /* Python */\n\ | |
23686 | .asciz \"" script_name "\"\n\ | |
23687 | .popsection \n\ | |
23688 | "); | |
23689 | @end example | |
23690 | ||
23691 | @noindent | |
ed3ef339 | 23692 | For Guile scripts, replace @code{.byte 1} with @code{.byte 3}. |
71b8c845 DE |
23693 | Then one can reference the macro in a header or source file like this: |
23694 | ||
23695 | @example | |
23696 | DEFINE_GDB_PY_SCRIPT ("my-app-scripts.py") | |
23697 | @end example | |
23698 | ||
23699 | The script name may include directories if desired. | |
23700 | ||
23701 | Note that loading of this script file also requires accordingly configured | |
23702 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
23703 | ||
23704 | If the macro invocation is put in a header, any application or library | |
23705 | using this header will get a reference to the specified script, | |
23706 | and with the use of @code{"MS"} attributes on the section, the linker | |
23707 | will remove duplicates. | |
23708 | ||
23709 | @node Which flavor to choose? | |
23710 | @subsection Which flavor to choose? | |
23711 | ||
23712 | Given the multiple ways of auto-loading extensions, it might not always | |
23713 | be clear which one to choose. This section provides some guidance. | |
23714 | ||
23715 | @noindent | |
23716 | Benefits of the @file{-gdb.@var{ext}} way: | |
23717 | ||
23718 | @itemize @bullet | |
23719 | @item | |
23720 | Can be used with file formats that don't support multiple sections. | |
23721 | ||
23722 | @item | |
23723 | Ease of finding scripts for public libraries. | |
23724 | ||
23725 | Scripts specified in the @code{.debug_gdb_scripts} section are searched for | |
23726 | in the source search path. | |
23727 | For publicly installed libraries, e.g., @file{libstdc++}, there typically | |
23728 | isn't a source directory in which to find the script. | |
23729 | ||
23730 | @item | |
23731 | Doesn't require source code additions. | |
23732 | @end itemize | |
23733 | ||
23734 | @noindent | |
23735 | Benefits of the @code{.debug_gdb_scripts} way: | |
23736 | ||
23737 | @itemize @bullet | |
23738 | @item | |
23739 | Works with static linking. | |
23740 | ||
23741 | Scripts for libraries done the @file{-gdb.@var{ext}} way require an objfile to | |
23742 | trigger their loading. When an application is statically linked the only | |
23743 | objfile available is the executable, and it is cumbersome to attach all the | |
23744 | scripts from all the input libraries to the executable's | |
23745 | @file{-gdb.@var{ext}} script. | |
23746 | ||
23747 | @item | |
23748 | Works with classes that are entirely inlined. | |
23749 | ||
23750 | Some classes can be entirely inlined, and thus there may not be an associated | |
23751 | shared library to attach a @file{-gdb.@var{ext}} script to. | |
23752 | ||
23753 | @item | |
23754 | Scripts needn't be copied out of the source tree. | |
23755 | ||
23756 | In some circumstances, apps can be built out of large collections of internal | |
23757 | libraries, and the build infrastructure necessary to install the | |
23758 | @file{-gdb.@var{ext}} scripts in a place where @value{GDBN} can find them is | |
23759 | cumbersome. It may be easier to specify the scripts in the | |
23760 | @code{.debug_gdb_scripts} section as relative paths, and add a path to the | |
23761 | top of the source tree to the source search path. | |
23762 | @end itemize | |
23763 | ||
ed3ef339 DE |
23764 | @node Multiple Extension Languages |
23765 | @section Multiple Extension Languages | |
23766 | ||
23767 | The Guile and Python extension languages do not share any state, | |
23768 | and generally do not interfere with each other. | |
23769 | There are some things to be aware of, however. | |
23770 | ||
23771 | @subsection Python comes first | |
23772 | ||
23773 | Python was @value{GDBN}'s first extension language, and to avoid breaking | |
23774 | existing behaviour Python comes first. This is generally solved by the | |
23775 | ``first one wins'' principle. @value{GDBN} maintains a list of enabled | |
23776 | extension languages, and when it makes a call to an extension language, | |
23777 | (say to pretty-print a value), it tries each in turn until an extension | |
23778 | language indicates it has performed the request (e.g., has returned the | |
23779 | pretty-printed form of a value). | |
23780 | This extends to errors while performing such requests: If an error happens | |
23781 | while, for example, trying to pretty-print an object then the error is | |
23782 | reported and any following extension languages are not tried. | |
23783 | ||
5a56e9c5 DE |
23784 | @node Aliases |
23785 | @section Creating new spellings of existing commands | |
23786 | @cindex aliases for commands | |
23787 | ||
23788 | It is often useful to define alternate spellings of existing commands. | |
23789 | For example, if a new @value{GDBN} command defined in Python has | |
23790 | a long name to type, it is handy to have an abbreviated version of it | |
23791 | that involves less typing. | |
23792 | ||
23793 | @value{GDBN} itself uses aliases. For example @samp{s} is an alias | |
23794 | of the @samp{step} command even though it is otherwise an ambiguous | |
23795 | abbreviation of other commands like @samp{set} and @samp{show}. | |
23796 | ||
23797 | Aliases are also used to provide shortened or more common versions | |
23798 | of multi-word commands. For example, @value{GDBN} provides the | |
23799 | @samp{tty} alias of the @samp{set inferior-tty} command. | |
23800 | ||
23801 | You can define a new alias with the @samp{alias} command. | |
23802 | ||
23803 | @table @code | |
23804 | ||
23805 | @kindex alias | |
23806 | @item alias [-a] [--] @var{ALIAS} = @var{COMMAND} | |
23807 | ||
23808 | @end table | |
23809 | ||
23810 | @var{ALIAS} specifies the name of the new alias. | |
23811 | Each word of @var{ALIAS} must consist of letters, numbers, dashes and | |
23812 | underscores. | |
23813 | ||
23814 | @var{COMMAND} specifies the name of an existing command | |
23815 | that is being aliased. | |
23816 | ||
23817 | The @samp{-a} option specifies that the new alias is an abbreviation | |
23818 | of the command. Abbreviations are not shown in command | |
23819 | lists displayed by the @samp{help} command. | |
23820 | ||
23821 | The @samp{--} option specifies the end of options, | |
23822 | and is useful when @var{ALIAS} begins with a dash. | |
23823 | ||
23824 | Here is a simple example showing how to make an abbreviation | |
23825 | of a command so that there is less to type. | |
23826 | Suppose you were tired of typing @samp{disas}, the current | |
23827 | shortest unambiguous abbreviation of the @samp{disassemble} command | |
23828 | and you wanted an even shorter version named @samp{di}. | |
23829 | The following will accomplish this. | |
23830 | ||
23831 | @smallexample | |
23832 | (gdb) alias -a di = disas | |
23833 | @end smallexample | |
23834 | ||
23835 | Note that aliases are different from user-defined commands. | |
23836 | With a user-defined command, you also need to write documentation | |
23837 | for it with the @samp{document} command. | |
23838 | An alias automatically picks up the documentation of the existing command. | |
23839 | ||
23840 | Here is an example where we make @samp{elms} an abbreviation of | |
23841 | @samp{elements} in the @samp{set print elements} command. | |
23842 | This is to show that you can make an abbreviation of any part | |
23843 | of a command. | |
23844 | ||
23845 | @smallexample | |
23846 | (gdb) alias -a set print elms = set print elements | |
23847 | (gdb) alias -a show print elms = show print elements | |
23848 | (gdb) set p elms 20 | |
23849 | (gdb) show p elms | |
23850 | Limit on string chars or array elements to print is 200. | |
23851 | @end smallexample | |
23852 | ||
23853 | Note that if you are defining an alias of a @samp{set} command, | |
23854 | and you want to have an alias for the corresponding @samp{show} | |
23855 | command, then you need to define the latter separately. | |
23856 | ||
23857 | Unambiguously abbreviated commands are allowed in @var{COMMAND} and | |
23858 | @var{ALIAS}, just as they are normally. | |
23859 | ||
23860 | @smallexample | |
23861 | (gdb) alias -a set pr elms = set p ele | |
23862 | @end smallexample | |
23863 | ||
23864 | Finally, here is an example showing the creation of a one word | |
23865 | alias for a more complex command. | |
23866 | This creates alias @samp{spe} of the command @samp{set print elements}. | |
23867 | ||
23868 | @smallexample | |
23869 | (gdb) alias spe = set print elements | |
23870 | (gdb) spe 20 | |
23871 | @end smallexample | |
23872 | ||
21c294e6 AC |
23873 | @node Interpreters |
23874 | @chapter Command Interpreters | |
23875 | @cindex command interpreters | |
23876 | ||
23877 | @value{GDBN} supports multiple command interpreters, and some command | |
23878 | infrastructure to allow users or user interface writers to switch | |
23879 | between interpreters or run commands in other interpreters. | |
23880 | ||
23881 | @value{GDBN} currently supports two command interpreters, the console | |
23882 | interpreter (sometimes called the command-line interpreter or @sc{cli}) | |
23883 | and the machine interface interpreter (or @sc{gdb/mi}). This manual | |
23884 | describes both of these interfaces in great detail. | |
23885 | ||
23886 | By default, @value{GDBN} will start with the console interpreter. | |
23887 | However, the user may choose to start @value{GDBN} with another | |
23888 | interpreter by specifying the @option{-i} or @option{--interpreter} | |
23889 | startup options. Defined interpreters include: | |
23890 | ||
23891 | @table @code | |
23892 | @item console | |
23893 | @cindex console interpreter | |
23894 | The traditional console or command-line interpreter. This is the most often | |
23895 | used interpreter with @value{GDBN}. With no interpreter specified at runtime, | |
23896 | @value{GDBN} will use this interpreter. | |
23897 | ||
23898 | @item mi | |
23899 | @cindex mi interpreter | |
23900 | The newest @sc{gdb/mi} interface (currently @code{mi2}). Used primarily | |
23901 | by programs wishing to use @value{GDBN} as a backend for a debugger GUI | |
23902 | or an IDE. For more information, see @ref{GDB/MI, ,The @sc{gdb/mi} | |
23903 | Interface}. | |
23904 | ||
23905 | @item mi2 | |
23906 | @cindex mi2 interpreter | |
23907 | The current @sc{gdb/mi} interface. | |
23908 | ||
23909 | @item mi1 | |
23910 | @cindex mi1 interpreter | |
23911 | The @sc{gdb/mi} interface included in @value{GDBN} 5.1, 5.2, and 5.3. | |
23912 | ||
23913 | @end table | |
23914 | ||
23915 | @cindex invoke another interpreter | |
23916 | The interpreter being used by @value{GDBN} may not be dynamically | |
23917 | switched at runtime. Although possible, this could lead to a very | |
23918 | precarious situation. Consider an IDE using @sc{gdb/mi}. If a user | |
23919 | enters the command "interpreter-set console" in a console view, | |
23920 | @value{GDBN} would switch to using the console interpreter, rendering | |
23921 | the IDE inoperable! | |
23922 | ||
23923 | @kindex interpreter-exec | |
23924 | Although you may only choose a single interpreter at startup, you may execute | |
23925 | commands in any interpreter from the current interpreter using the appropriate | |
23926 | command. If you are running the console interpreter, simply use the | |
23927 | @code{interpreter-exec} command: | |
23928 | ||
23929 | @smallexample | |
23930 | interpreter-exec mi "-data-list-register-names" | |
23931 | @end smallexample | |
23932 | ||
23933 | @sc{gdb/mi} has a similar command, although it is only available in versions of | |
23934 | @value{GDBN} which support @sc{gdb/mi} version 2 (or greater). | |
23935 | ||
8e04817f AC |
23936 | @node TUI |
23937 | @chapter @value{GDBN} Text User Interface | |
23938 | @cindex TUI | |
d0d5df6f | 23939 | @cindex Text User Interface |
c906108c | 23940 | |
8e04817f AC |
23941 | @menu |
23942 | * TUI Overview:: TUI overview | |
23943 | * TUI Keys:: TUI key bindings | |
7cf36c78 | 23944 | * TUI Single Key Mode:: TUI single key mode |
db2e3e2e | 23945 | * TUI Commands:: TUI-specific commands |
8e04817f AC |
23946 | * TUI Configuration:: TUI configuration variables |
23947 | @end menu | |
c906108c | 23948 | |
46ba6afa | 23949 | The @value{GDBN} Text User Interface (TUI) is a terminal |
d0d5df6f AC |
23950 | interface which uses the @code{curses} library to show the source |
23951 | file, the assembly output, the program registers and @value{GDBN} | |
46ba6afa BW |
23952 | commands in separate text windows. The TUI mode is supported only |
23953 | on platforms where a suitable version of the @code{curses} library | |
23954 | is available. | |
d0d5df6f | 23955 | |
46ba6afa | 23956 | The TUI mode is enabled by default when you invoke @value{GDBN} as |
217bff3e | 23957 | @samp{@value{GDBP} -tui}. |
46ba6afa BW |
23958 | You can also switch in and out of TUI mode while @value{GDBN} runs by |
23959 | using various TUI commands and key bindings, such as @kbd{C-x C-a}. | |
23960 | @xref{TUI Keys, ,TUI Key Bindings}. | |
c906108c | 23961 | |
8e04817f | 23962 | @node TUI Overview |
79a6e687 | 23963 | @section TUI Overview |
c906108c | 23964 | |
46ba6afa | 23965 | In TUI mode, @value{GDBN} can display several text windows: |
c906108c | 23966 | |
8e04817f AC |
23967 | @table @emph |
23968 | @item command | |
23969 | This window is the @value{GDBN} command window with the @value{GDBN} | |
46ba6afa BW |
23970 | prompt and the @value{GDBN} output. The @value{GDBN} input is still |
23971 | managed using readline. | |
c906108c | 23972 | |
8e04817f AC |
23973 | @item source |
23974 | The source window shows the source file of the program. The current | |
46ba6afa | 23975 | line and active breakpoints are displayed in this window. |
c906108c | 23976 | |
8e04817f AC |
23977 | @item assembly |
23978 | The assembly window shows the disassembly output of the program. | |
c906108c | 23979 | |
8e04817f | 23980 | @item register |
46ba6afa BW |
23981 | This window shows the processor registers. Registers are highlighted |
23982 | when their values change. | |
c906108c SS |
23983 | @end table |
23984 | ||
269c21fe | 23985 | The source and assembly windows show the current program position |
46ba6afa BW |
23986 | by highlighting the current line and marking it with a @samp{>} marker. |
23987 | Breakpoints are indicated with two markers. The first marker | |
269c21fe SC |
23988 | indicates the breakpoint type: |
23989 | ||
23990 | @table @code | |
23991 | @item B | |
23992 | Breakpoint which was hit at least once. | |
23993 | ||
23994 | @item b | |
23995 | Breakpoint which was never hit. | |
23996 | ||
23997 | @item H | |
23998 | Hardware breakpoint which was hit at least once. | |
23999 | ||
24000 | @item h | |
24001 | Hardware breakpoint which was never hit. | |
269c21fe SC |
24002 | @end table |
24003 | ||
24004 | The second marker indicates whether the breakpoint is enabled or not: | |
24005 | ||
24006 | @table @code | |
24007 | @item + | |
24008 | Breakpoint is enabled. | |
24009 | ||
24010 | @item - | |
24011 | Breakpoint is disabled. | |
269c21fe SC |
24012 | @end table |
24013 | ||
46ba6afa BW |
24014 | The source, assembly and register windows are updated when the current |
24015 | thread changes, when the frame changes, or when the program counter | |
24016 | changes. | |
24017 | ||
24018 | These windows are not all visible at the same time. The command | |
24019 | window is always visible. The others can be arranged in several | |
24020 | layouts: | |
c906108c | 24021 | |
8e04817f AC |
24022 | @itemize @bullet |
24023 | @item | |
46ba6afa | 24024 | source only, |
2df3850c | 24025 | |
8e04817f | 24026 | @item |
46ba6afa | 24027 | assembly only, |
8e04817f AC |
24028 | |
24029 | @item | |
46ba6afa | 24030 | source and assembly, |
8e04817f AC |
24031 | |
24032 | @item | |
46ba6afa | 24033 | source and registers, or |
c906108c | 24034 | |
8e04817f | 24035 | @item |
46ba6afa | 24036 | assembly and registers. |
8e04817f | 24037 | @end itemize |
c906108c | 24038 | |
46ba6afa | 24039 | A status line above the command window shows the following information: |
b7bb15bc SC |
24040 | |
24041 | @table @emph | |
24042 | @item target | |
46ba6afa | 24043 | Indicates the current @value{GDBN} target. |
b7bb15bc SC |
24044 | (@pxref{Targets, ,Specifying a Debugging Target}). |
24045 | ||
24046 | @item process | |
46ba6afa | 24047 | Gives the current process or thread number. |
b7bb15bc SC |
24048 | When no process is being debugged, this field is set to @code{No process}. |
24049 | ||
24050 | @item function | |
24051 | Gives the current function name for the selected frame. | |
24052 | The name is demangled if demangling is turned on (@pxref{Print Settings}). | |
46ba6afa | 24053 | When there is no symbol corresponding to the current program counter, |
b7bb15bc SC |
24054 | the string @code{??} is displayed. |
24055 | ||
24056 | @item line | |
24057 | Indicates the current line number for the selected frame. | |
46ba6afa | 24058 | When the current line number is not known, the string @code{??} is displayed. |
b7bb15bc SC |
24059 | |
24060 | @item pc | |
24061 | Indicates the current program counter address. | |
b7bb15bc SC |
24062 | @end table |
24063 | ||
8e04817f AC |
24064 | @node TUI Keys |
24065 | @section TUI Key Bindings | |
24066 | @cindex TUI key bindings | |
c906108c | 24067 | |
8e04817f | 24068 | The TUI installs several key bindings in the readline keymaps |
39037522 TT |
24069 | @ifset SYSTEM_READLINE |
24070 | (@pxref{Command Line Editing, , , rluserman, GNU Readline Library}). | |
24071 | @end ifset | |
24072 | @ifclear SYSTEM_READLINE | |
24073 | (@pxref{Command Line Editing}). | |
24074 | @end ifclear | |
24075 | The following key bindings are installed for both TUI mode and the | |
24076 | @value{GDBN} standard mode. | |
c906108c | 24077 | |
8e04817f AC |
24078 | @table @kbd |
24079 | @kindex C-x C-a | |
24080 | @item C-x C-a | |
24081 | @kindex C-x a | |
24082 | @itemx C-x a | |
24083 | @kindex C-x A | |
24084 | @itemx C-x A | |
46ba6afa BW |
24085 | Enter or leave the TUI mode. When leaving the TUI mode, |
24086 | the curses window management stops and @value{GDBN} operates using | |
24087 | its standard mode, writing on the terminal directly. When reentering | |
24088 | the TUI mode, control is given back to the curses windows. | |
8e04817f | 24089 | The screen is then refreshed. |
c906108c | 24090 | |
8e04817f AC |
24091 | @kindex C-x 1 |
24092 | @item C-x 1 | |
24093 | Use a TUI layout with only one window. The layout will | |
24094 | either be @samp{source} or @samp{assembly}. When the TUI mode | |
24095 | is not active, it will switch to the TUI mode. | |
2df3850c | 24096 | |
8e04817f | 24097 | Think of this key binding as the Emacs @kbd{C-x 1} binding. |
c906108c | 24098 | |
8e04817f AC |
24099 | @kindex C-x 2 |
24100 | @item C-x 2 | |
24101 | Use a TUI layout with at least two windows. When the current | |
46ba6afa | 24102 | layout already has two windows, the next layout with two windows is used. |
8e04817f AC |
24103 | When a new layout is chosen, one window will always be common to the |
24104 | previous layout and the new one. | |
c906108c | 24105 | |
8e04817f | 24106 | Think of it as the Emacs @kbd{C-x 2} binding. |
2df3850c | 24107 | |
72ffddc9 SC |
24108 | @kindex C-x o |
24109 | @item C-x o | |
24110 | Change the active window. The TUI associates several key bindings | |
46ba6afa | 24111 | (like scrolling and arrow keys) with the active window. This command |
72ffddc9 SC |
24112 | gives the focus to the next TUI window. |
24113 | ||
24114 | Think of it as the Emacs @kbd{C-x o} binding. | |
24115 | ||
7cf36c78 SC |
24116 | @kindex C-x s |
24117 | @item C-x s | |
46ba6afa BW |
24118 | Switch in and out of the TUI SingleKey mode that binds single |
24119 | keys to @value{GDBN} commands (@pxref{TUI Single Key Mode}). | |
c906108c SS |
24120 | @end table |
24121 | ||
46ba6afa | 24122 | The following key bindings only work in the TUI mode: |
5d161b24 | 24123 | |
46ba6afa | 24124 | @table @asis |
8e04817f | 24125 | @kindex PgUp |
46ba6afa | 24126 | @item @key{PgUp} |
8e04817f | 24127 | Scroll the active window one page up. |
c906108c | 24128 | |
8e04817f | 24129 | @kindex PgDn |
46ba6afa | 24130 | @item @key{PgDn} |
8e04817f | 24131 | Scroll the active window one page down. |
c906108c | 24132 | |
8e04817f | 24133 | @kindex Up |
46ba6afa | 24134 | @item @key{Up} |
8e04817f | 24135 | Scroll the active window one line up. |
c906108c | 24136 | |
8e04817f | 24137 | @kindex Down |
46ba6afa | 24138 | @item @key{Down} |
8e04817f | 24139 | Scroll the active window one line down. |
c906108c | 24140 | |
8e04817f | 24141 | @kindex Left |
46ba6afa | 24142 | @item @key{Left} |
8e04817f | 24143 | Scroll the active window one column left. |
c906108c | 24144 | |
8e04817f | 24145 | @kindex Right |
46ba6afa | 24146 | @item @key{Right} |
8e04817f | 24147 | Scroll the active window one column right. |
c906108c | 24148 | |
8e04817f | 24149 | @kindex C-L |
46ba6afa | 24150 | @item @kbd{C-L} |
8e04817f | 24151 | Refresh the screen. |
8e04817f | 24152 | @end table |
c906108c | 24153 | |
46ba6afa BW |
24154 | Because the arrow keys scroll the active window in the TUI mode, they |
24155 | are not available for their normal use by readline unless the command | |
24156 | window has the focus. When another window is active, you must use | |
24157 | other readline key bindings such as @kbd{C-p}, @kbd{C-n}, @kbd{C-b} | |
24158 | and @kbd{C-f} to control the command window. | |
8e04817f | 24159 | |
7cf36c78 SC |
24160 | @node TUI Single Key Mode |
24161 | @section TUI Single Key Mode | |
24162 | @cindex TUI single key mode | |
24163 | ||
46ba6afa BW |
24164 | The TUI also provides a @dfn{SingleKey} mode, which binds several |
24165 | frequently used @value{GDBN} commands to single keys. Type @kbd{C-x s} to | |
24166 | switch into this mode, where the following key bindings are used: | |
7cf36c78 SC |
24167 | |
24168 | @table @kbd | |
24169 | @kindex c @r{(SingleKey TUI key)} | |
24170 | @item c | |
24171 | continue | |
24172 | ||
24173 | @kindex d @r{(SingleKey TUI key)} | |
24174 | @item d | |
24175 | down | |
24176 | ||
24177 | @kindex f @r{(SingleKey TUI key)} | |
24178 | @item f | |
24179 | finish | |
24180 | ||
24181 | @kindex n @r{(SingleKey TUI key)} | |
24182 | @item n | |
24183 | next | |
24184 | ||
24185 | @kindex q @r{(SingleKey TUI key)} | |
24186 | @item q | |
46ba6afa | 24187 | exit the SingleKey mode. |
7cf36c78 SC |
24188 | |
24189 | @kindex r @r{(SingleKey TUI key)} | |
24190 | @item r | |
24191 | run | |
24192 | ||
24193 | @kindex s @r{(SingleKey TUI key)} | |
24194 | @item s | |
24195 | step | |
24196 | ||
24197 | @kindex u @r{(SingleKey TUI key)} | |
24198 | @item u | |
24199 | up | |
24200 | ||
24201 | @kindex v @r{(SingleKey TUI key)} | |
24202 | @item v | |
24203 | info locals | |
24204 | ||
24205 | @kindex w @r{(SingleKey TUI key)} | |
24206 | @item w | |
24207 | where | |
7cf36c78 SC |
24208 | @end table |
24209 | ||
24210 | Other keys temporarily switch to the @value{GDBN} command prompt. | |
24211 | The key that was pressed is inserted in the editing buffer so that | |
24212 | it is possible to type most @value{GDBN} commands without interaction | |
46ba6afa BW |
24213 | with the TUI SingleKey mode. Once the command is entered the TUI |
24214 | SingleKey mode is restored. The only way to permanently leave | |
7f9087cb | 24215 | this mode is by typing @kbd{q} or @kbd{C-x s}. |
7cf36c78 SC |
24216 | |
24217 | ||
8e04817f | 24218 | @node TUI Commands |
db2e3e2e | 24219 | @section TUI-specific Commands |
8e04817f AC |
24220 | @cindex TUI commands |
24221 | ||
24222 | The TUI has specific commands to control the text windows. | |
46ba6afa BW |
24223 | These commands are always available, even when @value{GDBN} is not in |
24224 | the TUI mode. When @value{GDBN} is in the standard mode, most | |
24225 | of these commands will automatically switch to the TUI mode. | |
c906108c | 24226 | |
ff12863f PA |
24227 | Note that if @value{GDBN}'s @code{stdout} is not connected to a |
24228 | terminal, or @value{GDBN} has been started with the machine interface | |
24229 | interpreter (@pxref{GDB/MI, ,The @sc{gdb/mi} Interface}), most of | |
24230 | these commands will fail with an error, because it would not be | |
24231 | possible or desirable to enable curses window management. | |
24232 | ||
c906108c | 24233 | @table @code |
3d757584 SC |
24234 | @item info win |
24235 | @kindex info win | |
24236 | List and give the size of all displayed windows. | |
24237 | ||
8e04817f | 24238 | @item layout next |
4644b6e3 | 24239 | @kindex layout |
8e04817f | 24240 | Display the next layout. |
2df3850c | 24241 | |
8e04817f | 24242 | @item layout prev |
8e04817f | 24243 | Display the previous layout. |
c906108c | 24244 | |
8e04817f | 24245 | @item layout src |
8e04817f | 24246 | Display the source window only. |
c906108c | 24247 | |
8e04817f | 24248 | @item layout asm |
8e04817f | 24249 | Display the assembly window only. |
c906108c | 24250 | |
8e04817f | 24251 | @item layout split |
8e04817f | 24252 | Display the source and assembly window. |
c906108c | 24253 | |
8e04817f | 24254 | @item layout regs |
8e04817f AC |
24255 | Display the register window together with the source or assembly window. |
24256 | ||
46ba6afa | 24257 | @item focus next |
8e04817f | 24258 | @kindex focus |
46ba6afa BW |
24259 | Make the next window active for scrolling. |
24260 | ||
24261 | @item focus prev | |
24262 | Make the previous window active for scrolling. | |
24263 | ||
24264 | @item focus src | |
24265 | Make the source window active for scrolling. | |
24266 | ||
24267 | @item focus asm | |
24268 | Make the assembly window active for scrolling. | |
24269 | ||
24270 | @item focus regs | |
24271 | Make the register window active for scrolling. | |
24272 | ||
24273 | @item focus cmd | |
24274 | Make the command window active for scrolling. | |
c906108c | 24275 | |
8e04817f AC |
24276 | @item refresh |
24277 | @kindex refresh | |
7f9087cb | 24278 | Refresh the screen. This is similar to typing @kbd{C-L}. |
c906108c | 24279 | |
6a1b180d SC |
24280 | @item tui reg float |
24281 | @kindex tui reg | |
24282 | Show the floating point registers in the register window. | |
24283 | ||
24284 | @item tui reg general | |
24285 | Show the general registers in the register window. | |
24286 | ||
24287 | @item tui reg next | |
24288 | Show the next register group. The list of register groups as well as | |
24289 | their order is target specific. The predefined register groups are the | |
24290 | following: @code{general}, @code{float}, @code{system}, @code{vector}, | |
24291 | @code{all}, @code{save}, @code{restore}. | |
24292 | ||
24293 | @item tui reg system | |
24294 | Show the system registers in the register window. | |
24295 | ||
8e04817f AC |
24296 | @item update |
24297 | @kindex update | |
24298 | Update the source window and the current execution point. | |
c906108c | 24299 | |
8e04817f AC |
24300 | @item winheight @var{name} +@var{count} |
24301 | @itemx winheight @var{name} -@var{count} | |
24302 | @kindex winheight | |
24303 | Change the height of the window @var{name} by @var{count} | |
24304 | lines. Positive counts increase the height, while negative counts | |
24305 | decrease it. | |
2df3850c | 24306 | |
46ba6afa BW |
24307 | @item tabset @var{nchars} |
24308 | @kindex tabset | |
c45da7e6 | 24309 | Set the width of tab stops to be @var{nchars} characters. |
c906108c SS |
24310 | @end table |
24311 | ||
8e04817f | 24312 | @node TUI Configuration |
79a6e687 | 24313 | @section TUI Configuration Variables |
8e04817f | 24314 | @cindex TUI configuration variables |
c906108c | 24315 | |
46ba6afa | 24316 | Several configuration variables control the appearance of TUI windows. |
c906108c | 24317 | |
8e04817f AC |
24318 | @table @code |
24319 | @item set tui border-kind @var{kind} | |
24320 | @kindex set tui border-kind | |
24321 | Select the border appearance for the source, assembly and register windows. | |
24322 | The possible values are the following: | |
24323 | @table @code | |
24324 | @item space | |
24325 | Use a space character to draw the border. | |
c906108c | 24326 | |
8e04817f | 24327 | @item ascii |
46ba6afa | 24328 | Use @sc{ascii} characters @samp{+}, @samp{-} and @samp{|} to draw the border. |
c906108c | 24329 | |
8e04817f AC |
24330 | @item acs |
24331 | Use the Alternate Character Set to draw the border. The border is | |
24332 | drawn using character line graphics if the terminal supports them. | |
8e04817f | 24333 | @end table |
c78b4128 | 24334 | |
8e04817f AC |
24335 | @item set tui border-mode @var{mode} |
24336 | @kindex set tui border-mode | |
46ba6afa BW |
24337 | @itemx set tui active-border-mode @var{mode} |
24338 | @kindex set tui active-border-mode | |
24339 | Select the display attributes for the borders of the inactive windows | |
24340 | or the active window. The @var{mode} can be one of the following: | |
8e04817f AC |
24341 | @table @code |
24342 | @item normal | |
24343 | Use normal attributes to display the border. | |
c906108c | 24344 | |
8e04817f AC |
24345 | @item standout |
24346 | Use standout mode. | |
c906108c | 24347 | |
8e04817f AC |
24348 | @item reverse |
24349 | Use reverse video mode. | |
c906108c | 24350 | |
8e04817f AC |
24351 | @item half |
24352 | Use half bright mode. | |
c906108c | 24353 | |
8e04817f AC |
24354 | @item half-standout |
24355 | Use half bright and standout mode. | |
c906108c | 24356 | |
8e04817f AC |
24357 | @item bold |
24358 | Use extra bright or bold mode. | |
c78b4128 | 24359 | |
8e04817f AC |
24360 | @item bold-standout |
24361 | Use extra bright or bold and standout mode. | |
8e04817f | 24362 | @end table |
8e04817f | 24363 | @end table |
c78b4128 | 24364 | |
8e04817f AC |
24365 | @node Emacs |
24366 | @chapter Using @value{GDBN} under @sc{gnu} Emacs | |
c78b4128 | 24367 | |
8e04817f AC |
24368 | @cindex Emacs |
24369 | @cindex @sc{gnu} Emacs | |
24370 | A special interface allows you to use @sc{gnu} Emacs to view (and | |
24371 | edit) the source files for the program you are debugging with | |
24372 | @value{GDBN}. | |
c906108c | 24373 | |
8e04817f AC |
24374 | To use this interface, use the command @kbd{M-x gdb} in Emacs. Give the |
24375 | executable file you want to debug as an argument. This command starts | |
24376 | @value{GDBN} as a subprocess of Emacs, with input and output through a newly | |
24377 | created Emacs buffer. | |
24378 | @c (Do not use the @code{-tui} option to run @value{GDBN} from Emacs.) | |
c906108c | 24379 | |
5e252a2e | 24380 | Running @value{GDBN} under Emacs can be just like running @value{GDBN} normally except for two |
8e04817f | 24381 | things: |
c906108c | 24382 | |
8e04817f AC |
24383 | @itemize @bullet |
24384 | @item | |
5e252a2e NR |
24385 | All ``terminal'' input and output goes through an Emacs buffer, called |
24386 | the GUD buffer. | |
c906108c | 24387 | |
8e04817f AC |
24388 | This applies both to @value{GDBN} commands and their output, and to the input |
24389 | and output done by the program you are debugging. | |
bf0184be | 24390 | |
8e04817f AC |
24391 | This is useful because it means that you can copy the text of previous |
24392 | commands and input them again; you can even use parts of the output | |
24393 | in this way. | |
bf0184be | 24394 | |
8e04817f AC |
24395 | All the facilities of Emacs' Shell mode are available for interacting |
24396 | with your program. In particular, you can send signals the usual | |
24397 | way---for example, @kbd{C-c C-c} for an interrupt, @kbd{C-c C-z} for a | |
24398 | stop. | |
bf0184be ND |
24399 | |
24400 | @item | |
8e04817f | 24401 | @value{GDBN} displays source code through Emacs. |
bf0184be | 24402 | |
8e04817f AC |
24403 | Each time @value{GDBN} displays a stack frame, Emacs automatically finds the |
24404 | source file for that frame and puts an arrow (@samp{=>}) at the | |
24405 | left margin of the current line. Emacs uses a separate buffer for | |
24406 | source display, and splits the screen to show both your @value{GDBN} session | |
24407 | and the source. | |
bf0184be | 24408 | |
8e04817f AC |
24409 | Explicit @value{GDBN} @code{list} or search commands still produce output as |
24410 | usual, but you probably have no reason to use them from Emacs. | |
5e252a2e NR |
24411 | @end itemize |
24412 | ||
24413 | We call this @dfn{text command mode}. Emacs 22.1, and later, also uses | |
24414 | a graphical mode, enabled by default, which provides further buffers | |
24415 | that can control the execution and describe the state of your program. | |
24416 | @xref{GDB Graphical Interface,,, Emacs, The @sc{gnu} Emacs Manual}. | |
c906108c | 24417 | |
64fabec2 AC |
24418 | If you specify an absolute file name when prompted for the @kbd{M-x |
24419 | gdb} argument, then Emacs sets your current working directory to where | |
24420 | your program resides. If you only specify the file name, then Emacs | |
7a9dd1b2 | 24421 | sets your current working directory to the directory associated |
64fabec2 AC |
24422 | with the previous buffer. In this case, @value{GDBN} may find your |
24423 | program by searching your environment's @code{PATH} variable, but on | |
24424 | some operating systems it might not find the source. So, although the | |
24425 | @value{GDBN} input and output session proceeds normally, the auxiliary | |
24426 | buffer does not display the current source and line of execution. | |
24427 | ||
24428 | The initial working directory of @value{GDBN} is printed on the top | |
5e252a2e NR |
24429 | line of the GUD buffer and this serves as a default for the commands |
24430 | that specify files for @value{GDBN} to operate on. @xref{Files, | |
24431 | ,Commands to Specify Files}. | |
64fabec2 AC |
24432 | |
24433 | By default, @kbd{M-x gdb} calls the program called @file{gdb}. If you | |
24434 | need to call @value{GDBN} by a different name (for example, if you | |
24435 | keep several configurations around, with different names) you can | |
24436 | customize the Emacs variable @code{gud-gdb-command-name} to run the | |
24437 | one you want. | |
8e04817f | 24438 | |
5e252a2e | 24439 | In the GUD buffer, you can use these special Emacs commands in |
8e04817f | 24440 | addition to the standard Shell mode commands: |
c906108c | 24441 | |
8e04817f AC |
24442 | @table @kbd |
24443 | @item C-h m | |
5e252a2e | 24444 | Describe the features of Emacs' GUD Mode. |
c906108c | 24445 | |
64fabec2 | 24446 | @item C-c C-s |
8e04817f AC |
24447 | Execute to another source line, like the @value{GDBN} @code{step} command; also |
24448 | update the display window to show the current file and location. | |
c906108c | 24449 | |
64fabec2 | 24450 | @item C-c C-n |
8e04817f AC |
24451 | Execute to next source line in this function, skipping all function |
24452 | calls, like the @value{GDBN} @code{next} command. Then update the display window | |
24453 | to show the current file and location. | |
c906108c | 24454 | |
64fabec2 | 24455 | @item C-c C-i |
8e04817f AC |
24456 | Execute one instruction, like the @value{GDBN} @code{stepi} command; update |
24457 | display window accordingly. | |
c906108c | 24458 | |
8e04817f AC |
24459 | @item C-c C-f |
24460 | Execute until exit from the selected stack frame, like the @value{GDBN} | |
24461 | @code{finish} command. | |
c906108c | 24462 | |
64fabec2 | 24463 | @item C-c C-r |
8e04817f AC |
24464 | Continue execution of your program, like the @value{GDBN} @code{continue} |
24465 | command. | |
b433d00b | 24466 | |
64fabec2 | 24467 | @item C-c < |
8e04817f AC |
24468 | Go up the number of frames indicated by the numeric argument |
24469 | (@pxref{Arguments, , Numeric Arguments, Emacs, The @sc{gnu} Emacs Manual}), | |
24470 | like the @value{GDBN} @code{up} command. | |
b433d00b | 24471 | |
64fabec2 | 24472 | @item C-c > |
8e04817f AC |
24473 | Go down the number of frames indicated by the numeric argument, like the |
24474 | @value{GDBN} @code{down} command. | |
8e04817f | 24475 | @end table |
c906108c | 24476 | |
7f9087cb | 24477 | In any source file, the Emacs command @kbd{C-x @key{SPC}} (@code{gud-break}) |
8e04817f | 24478 | tells @value{GDBN} to set a breakpoint on the source line point is on. |
c906108c | 24479 | |
5e252a2e NR |
24480 | In text command mode, if you type @kbd{M-x speedbar}, Emacs displays a |
24481 | separate frame which shows a backtrace when the GUD buffer is current. | |
24482 | Move point to any frame in the stack and type @key{RET} to make it | |
24483 | become the current frame and display the associated source in the | |
24484 | source buffer. Alternatively, click @kbd{Mouse-2} to make the | |
24485 | selected frame become the current one. In graphical mode, the | |
24486 | speedbar displays watch expressions. | |
64fabec2 | 24487 | |
8e04817f AC |
24488 | If you accidentally delete the source-display buffer, an easy way to get |
24489 | it back is to type the command @code{f} in the @value{GDBN} buffer, to | |
24490 | request a frame display; when you run under Emacs, this recreates | |
24491 | the source buffer if necessary to show you the context of the current | |
24492 | frame. | |
c906108c | 24493 | |
8e04817f AC |
24494 | The source files displayed in Emacs are in ordinary Emacs buffers |
24495 | which are visiting the source files in the usual way. You can edit | |
24496 | the files with these buffers if you wish; but keep in mind that @value{GDBN} | |
24497 | communicates with Emacs in terms of line numbers. If you add or | |
24498 | delete lines from the text, the line numbers that @value{GDBN} knows cease | |
24499 | to correspond properly with the code. | |
b383017d | 24500 | |
5e252a2e NR |
24501 | A more detailed description of Emacs' interaction with @value{GDBN} is |
24502 | given in the Emacs manual (@pxref{Debuggers,,, Emacs, The @sc{gnu} | |
24503 | Emacs Manual}). | |
c906108c | 24504 | |
922fbb7b AC |
24505 | @node GDB/MI |
24506 | @chapter The @sc{gdb/mi} Interface | |
24507 | ||
24508 | @unnumberedsec Function and Purpose | |
24509 | ||
24510 | @cindex @sc{gdb/mi}, its purpose | |
6b5e8c01 NR |
24511 | @sc{gdb/mi} is a line based machine oriented text interface to |
24512 | @value{GDBN} and is activated by specifying using the | |
24513 | @option{--interpreter} command line option (@pxref{Mode Options}). It | |
24514 | is specifically intended to support the development of systems which | |
24515 | use the debugger as just one small component of a larger system. | |
922fbb7b AC |
24516 | |
24517 | This chapter is a specification of the @sc{gdb/mi} interface. It is written | |
24518 | in the form of a reference manual. | |
24519 | ||
24520 | Note that @sc{gdb/mi} is still under construction, so some of the | |
af6eff6f NR |
24521 | features described below are incomplete and subject to change |
24522 | (@pxref{GDB/MI Development and Front Ends, , @sc{gdb/mi} Development and Front Ends}). | |
922fbb7b AC |
24523 | |
24524 | @unnumberedsec Notation and Terminology | |
24525 | ||
24526 | @cindex notational conventions, for @sc{gdb/mi} | |
24527 | This chapter uses the following notation: | |
24528 | ||
24529 | @itemize @bullet | |
24530 | @item | |
24531 | @code{|} separates two alternatives. | |
24532 | ||
24533 | @item | |
24534 | @code{[ @var{something} ]} indicates that @var{something} is optional: | |
24535 | it may or may not be given. | |
24536 | ||
24537 | @item | |
24538 | @code{( @var{group} )*} means that @var{group} inside the parentheses | |
24539 | may repeat zero or more times. | |
24540 | ||
24541 | @item | |
24542 | @code{( @var{group} )+} means that @var{group} inside the parentheses | |
24543 | may repeat one or more times. | |
24544 | ||
24545 | @item | |
24546 | @code{"@var{string}"} means a literal @var{string}. | |
24547 | @end itemize | |
24548 | ||
24549 | @ignore | |
24550 | @heading Dependencies | |
24551 | @end ignore | |
24552 | ||
922fbb7b | 24553 | @menu |
c3b108f7 | 24554 | * GDB/MI General Design:: |
922fbb7b AC |
24555 | * GDB/MI Command Syntax:: |
24556 | * GDB/MI Compatibility with CLI:: | |
af6eff6f | 24557 | * GDB/MI Development and Front Ends:: |
922fbb7b | 24558 | * GDB/MI Output Records:: |
ef21caaf | 24559 | * GDB/MI Simple Examples:: |
922fbb7b | 24560 | * GDB/MI Command Description Format:: |
ef21caaf | 24561 | * GDB/MI Breakpoint Commands:: |
3fa7bf06 | 24562 | * GDB/MI Catchpoint Commands:: |
a2c02241 NR |
24563 | * GDB/MI Program Context:: |
24564 | * GDB/MI Thread Commands:: | |
5d77fe44 | 24565 | * GDB/MI Ada Tasking Commands:: |
a2c02241 NR |
24566 | * GDB/MI Program Execution:: |
24567 | * GDB/MI Stack Manipulation:: | |
24568 | * GDB/MI Variable Objects:: | |
922fbb7b | 24569 | * GDB/MI Data Manipulation:: |
a2c02241 NR |
24570 | * GDB/MI Tracepoint Commands:: |
24571 | * GDB/MI Symbol Query:: | |
351ff01a | 24572 | * GDB/MI File Commands:: |
922fbb7b AC |
24573 | @ignore |
24574 | * GDB/MI Kod Commands:: | |
24575 | * GDB/MI Memory Overlay Commands:: | |
24576 | * GDB/MI Signal Handling Commands:: | |
24577 | @end ignore | |
922fbb7b | 24578 | * GDB/MI Target Manipulation:: |
a6b151f1 | 24579 | * GDB/MI File Transfer Commands:: |
58d06528 | 24580 | * GDB/MI Ada Exceptions Commands:: |
d192b373 | 24581 | * GDB/MI Support Commands:: |
ef21caaf | 24582 | * GDB/MI Miscellaneous Commands:: |
922fbb7b AC |
24583 | @end menu |
24584 | ||
c3b108f7 VP |
24585 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24586 | @node GDB/MI General Design | |
24587 | @section @sc{gdb/mi} General Design | |
24588 | @cindex GDB/MI General Design | |
24589 | ||
24590 | Interaction of a @sc{GDB/MI} frontend with @value{GDBN} involves three | |
24591 | parts---commands sent to @value{GDBN}, responses to those commands | |
24592 | and notifications. Each command results in exactly one response, | |
24593 | indicating either successful completion of the command, or an error. | |
24594 | For the commands that do not resume the target, the response contains the | |
24595 | requested information. For the commands that resume the target, the | |
24596 | response only indicates whether the target was successfully resumed. | |
24597 | Notifications is the mechanism for reporting changes in the state of the | |
24598 | target, or in @value{GDBN} state, that cannot conveniently be associated with | |
24599 | a command and reported as part of that command response. | |
24600 | ||
24601 | The important examples of notifications are: | |
24602 | @itemize @bullet | |
24603 | ||
24604 | @item | |
24605 | Exec notifications. These are used to report changes in | |
24606 | target state---when a target is resumed, or stopped. It would not | |
24607 | be feasible to include this information in response of resuming | |
24608 | commands, because one resume commands can result in multiple events in | |
24609 | different threads. Also, quite some time may pass before any event | |
24610 | happens in the target, while a frontend needs to know whether the resuming | |
24611 | command itself was successfully executed. | |
24612 | ||
24613 | @item | |
24614 | Console output, and status notifications. Console output | |
24615 | notifications are used to report output of CLI commands, as well as | |
24616 | diagnostics for other commands. Status notifications are used to | |
24617 | report the progress of a long-running operation. Naturally, including | |
24618 | this information in command response would mean no output is produced | |
24619 | until the command is finished, which is undesirable. | |
24620 | ||
24621 | @item | |
24622 | General notifications. Commands may have various side effects on | |
24623 | the @value{GDBN} or target state beyond their official purpose. For example, | |
24624 | a command may change the selected thread. Although such changes can | |
24625 | be included in command response, using notification allows for more | |
24626 | orthogonal frontend design. | |
24627 | ||
24628 | @end itemize | |
24629 | ||
24630 | There's no guarantee that whenever an MI command reports an error, | |
24631 | @value{GDBN} or the target are in any specific state, and especially, | |
24632 | the state is not reverted to the state before the MI command was | |
24633 | processed. Therefore, whenever an MI command results in an error, | |
24634 | we recommend that the frontend refreshes all the information shown in | |
24635 | the user interface. | |
24636 | ||
508094de NR |
24637 | |
24638 | @menu | |
24639 | * Context management:: | |
24640 | * Asynchronous and non-stop modes:: | |
24641 | * Thread groups:: | |
24642 | @end menu | |
24643 | ||
24644 | @node Context management | |
c3b108f7 VP |
24645 | @subsection Context management |
24646 | ||
403cb6b1 JB |
24647 | @subsubsection Threads and Frames |
24648 | ||
c3b108f7 VP |
24649 | In most cases when @value{GDBN} accesses the target, this access is |
24650 | done in context of a specific thread and frame (@pxref{Frames}). | |
24651 | Often, even when accessing global data, the target requires that a thread | |
24652 | be specified. The CLI interface maintains the selected thread and frame, | |
24653 | and supplies them to target on each command. This is convenient, | |
24654 | because a command line user would not want to specify that information | |
24655 | explicitly on each command, and because user interacts with | |
24656 | @value{GDBN} via a single terminal, so no confusion is possible as | |
24657 | to what thread and frame are the current ones. | |
24658 | ||
24659 | In the case of MI, the concept of selected thread and frame is less | |
24660 | useful. First, a frontend can easily remember this information | |
24661 | itself. Second, a graphical frontend can have more than one window, | |
24662 | each one used for debugging a different thread, and the frontend might | |
24663 | want to access additional threads for internal purposes. This | |
24664 | increases the risk that by relying on implicitly selected thread, the | |
24665 | frontend may be operating on a wrong one. Therefore, each MI command | |
24666 | should explicitly specify which thread and frame to operate on. To | |
24667 | make it possible, each MI command accepts the @samp{--thread} and | |
24668 | @samp{--frame} options, the value to each is @value{GDBN} identifier | |
24669 | for thread and frame to operate on. | |
24670 | ||
24671 | Usually, each top-level window in a frontend allows the user to select | |
24672 | a thread and a frame, and remembers the user selection for further | |
24673 | operations. However, in some cases @value{GDBN} may suggest that the | |
24674 | current thread be changed. For example, when stopping on a breakpoint | |
24675 | it is reasonable to switch to the thread where breakpoint is hit. For | |
24676 | another example, if the user issues the CLI @samp{thread} command via | |
24677 | the frontend, it is desirable to change the frontend's selected thread to the | |
24678 | one specified by user. @value{GDBN} communicates the suggestion to | |
24679 | change current thread using the @samp{=thread-selected} notification. | |
24680 | No such notification is available for the selected frame at the moment. | |
24681 | ||
24682 | Note that historically, MI shares the selected thread with CLI, so | |
24683 | frontends used the @code{-thread-select} to execute commands in the | |
24684 | right context. However, getting this to work right is cumbersome. The | |
24685 | simplest way is for frontend to emit @code{-thread-select} command | |
24686 | before every command. This doubles the number of commands that need | |
24687 | to be sent. The alternative approach is to suppress @code{-thread-select} | |
24688 | if the selected thread in @value{GDBN} is supposed to be identical to the | |
24689 | thread the frontend wants to operate on. However, getting this | |
24690 | optimization right can be tricky. In particular, if the frontend | |
24691 | sends several commands to @value{GDBN}, and one of the commands changes the | |
24692 | selected thread, then the behaviour of subsequent commands will | |
24693 | change. So, a frontend should either wait for response from such | |
24694 | problematic commands, or explicitly add @code{-thread-select} for | |
24695 | all subsequent commands. No frontend is known to do this exactly | |
24696 | right, so it is suggested to just always pass the @samp{--thread} and | |
24697 | @samp{--frame} options. | |
24698 | ||
403cb6b1 JB |
24699 | @subsubsection Language |
24700 | ||
24701 | The execution of several commands depends on which language is selected. | |
24702 | By default, the current language (@pxref{show language}) is used. | |
24703 | But for commands known to be language-sensitive, it is recommended | |
24704 | to use the @samp{--language} option. This option takes one argument, | |
24705 | which is the name of the language to use while executing the command. | |
24706 | For instance: | |
24707 | ||
24708 | @smallexample | |
24709 | -data-evaluate-expression --language c "sizeof (void*)" | |
24710 | ^done,value="4" | |
24711 | (gdb) | |
24712 | @end smallexample | |
24713 | ||
24714 | The valid language names are the same names accepted by the | |
24715 | @samp{set language} command (@pxref{Manually}), excluding @samp{auto}, | |
24716 | @samp{local} or @samp{unknown}. | |
24717 | ||
508094de | 24718 | @node Asynchronous and non-stop modes |
c3b108f7 VP |
24719 | @subsection Asynchronous command execution and non-stop mode |
24720 | ||
24721 | On some targets, @value{GDBN} is capable of processing MI commands | |
24722 | even while the target is running. This is called @dfn{asynchronous | |
24723 | command execution} (@pxref{Background Execution}). The frontend may | |
24724 | specify a preferrence for asynchronous execution using the | |
329ea579 | 24725 | @code{-gdb-set mi-async 1} command, which should be emitted before |
c3b108f7 VP |
24726 | either running the executable or attaching to the target. After the |
24727 | frontend has started the executable or attached to the target, it can | |
24728 | find if asynchronous execution is enabled using the | |
24729 | @code{-list-target-features} command. | |
24730 | ||
329ea579 PA |
24731 | @table @code |
24732 | @item -gdb-set mi-async on | |
24733 | @item -gdb-set mi-async off | |
24734 | Set whether MI is in asynchronous mode. | |
24735 | ||
24736 | When @code{off}, which is the default, MI execution commands (e.g., | |
24737 | @code{-exec-continue}) are foreground commands, and @value{GDBN} waits | |
24738 | for the program to stop before processing further commands. | |
24739 | ||
24740 | When @code{on}, MI execution commands are background execution | |
24741 | commands (e.g., @code{-exec-continue} becomes the equivalent of the | |
24742 | @code{c&} CLI command), and so @value{GDBN} is capable of processing | |
24743 | MI commands even while the target is running. | |
24744 | ||
24745 | @item -gdb-show mi-async | |
24746 | Show whether MI asynchronous mode is enabled. | |
24747 | @end table | |
24748 | ||
24749 | Note: In @value{GDBN} version 7.7 and earlier, this option was called | |
24750 | @code{target-async} instead of @code{mi-async}, and it had the effect | |
24751 | of both putting MI in asynchronous mode and making CLI background | |
24752 | commands possible. CLI background commands are now always possible | |
24753 | ``out of the box'' if the target supports them. The old spelling is | |
24754 | kept as a deprecated alias for backwards compatibility. | |
24755 | ||
c3b108f7 VP |
24756 | Even if @value{GDBN} can accept a command while target is running, |
24757 | many commands that access the target do not work when the target is | |
24758 | running. Therefore, asynchronous command execution is most useful | |
24759 | when combined with non-stop mode (@pxref{Non-Stop Mode}). Then, | |
24760 | it is possible to examine the state of one thread, while other threads | |
24761 | are running. | |
24762 | ||
24763 | When a given thread is running, MI commands that try to access the | |
24764 | target in the context of that thread may not work, or may work only on | |
24765 | some targets. In particular, commands that try to operate on thread's | |
24766 | stack will not work, on any target. Commands that read memory, or | |
24767 | modify breakpoints, may work or not work, depending on the target. Note | |
24768 | that even commands that operate on global state, such as @code{print}, | |
24769 | @code{set}, and breakpoint commands, still access the target in the | |
24770 | context of a specific thread, so frontend should try to find a | |
24771 | stopped thread and perform the operation on that thread (using the | |
24772 | @samp{--thread} option). | |
24773 | ||
24774 | Which commands will work in the context of a running thread is | |
24775 | highly target dependent. However, the two commands | |
24776 | @code{-exec-interrupt}, to stop a thread, and @code{-thread-info}, | |
24777 | to find the state of a thread, will always work. | |
24778 | ||
508094de | 24779 | @node Thread groups |
c3b108f7 VP |
24780 | @subsection Thread groups |
24781 | @value{GDBN} may be used to debug several processes at the same time. | |
24782 | On some platfroms, @value{GDBN} may support debugging of several | |
24783 | hardware systems, each one having several cores with several different | |
24784 | processes running on each core. This section describes the MI | |
24785 | mechanism to support such debugging scenarios. | |
24786 | ||
24787 | The key observation is that regardless of the structure of the | |
24788 | target, MI can have a global list of threads, because most commands that | |
24789 | accept the @samp{--thread} option do not need to know what process that | |
24790 | thread belongs to. Therefore, it is not necessary to introduce | |
24791 | neither additional @samp{--process} option, nor an notion of the | |
24792 | current process in the MI interface. The only strictly new feature | |
24793 | that is required is the ability to find how the threads are grouped | |
24794 | into processes. | |
24795 | ||
24796 | To allow the user to discover such grouping, and to support arbitrary | |
24797 | hierarchy of machines/cores/processes, MI introduces the concept of a | |
24798 | @dfn{thread group}. Thread group is a collection of threads and other | |
24799 | thread groups. A thread group always has a string identifier, a type, | |
24800 | and may have additional attributes specific to the type. A new | |
24801 | command, @code{-list-thread-groups}, returns the list of top-level | |
24802 | thread groups, which correspond to processes that @value{GDBN} is | |
24803 | debugging at the moment. By passing an identifier of a thread group | |
24804 | to the @code{-list-thread-groups} command, it is possible to obtain | |
24805 | the members of specific thread group. | |
24806 | ||
24807 | To allow the user to easily discover processes, and other objects, he | |
24808 | wishes to debug, a concept of @dfn{available thread group} is | |
24809 | introduced. Available thread group is an thread group that | |
24810 | @value{GDBN} is not debugging, but that can be attached to, using the | |
24811 | @code{-target-attach} command. The list of available top-level thread | |
24812 | groups can be obtained using @samp{-list-thread-groups --available}. | |
24813 | In general, the content of a thread group may be only retrieved only | |
24814 | after attaching to that thread group. | |
24815 | ||
a79b8f6e VP |
24816 | Thread groups are related to inferiors (@pxref{Inferiors and |
24817 | Programs}). Each inferior corresponds to a thread group of a special | |
24818 | type @samp{process}, and some additional operations are permitted on | |
24819 | such thread groups. | |
24820 | ||
922fbb7b AC |
24821 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24822 | @node GDB/MI Command Syntax | |
24823 | @section @sc{gdb/mi} Command Syntax | |
24824 | ||
24825 | @menu | |
24826 | * GDB/MI Input Syntax:: | |
24827 | * GDB/MI Output Syntax:: | |
922fbb7b AC |
24828 | @end menu |
24829 | ||
24830 | @node GDB/MI Input Syntax | |
24831 | @subsection @sc{gdb/mi} Input Syntax | |
24832 | ||
24833 | @cindex input syntax for @sc{gdb/mi} | |
24834 | @cindex @sc{gdb/mi}, input syntax | |
24835 | @table @code | |
24836 | @item @var{command} @expansion{} | |
24837 | @code{@var{cli-command} | @var{mi-command}} | |
24838 | ||
24839 | @item @var{cli-command} @expansion{} | |
24840 | @code{[ @var{token} ] @var{cli-command} @var{nl}}, where | |
24841 | @var{cli-command} is any existing @value{GDBN} CLI command. | |
24842 | ||
24843 | @item @var{mi-command} @expansion{} | |
24844 | @code{[ @var{token} ] "-" @var{operation} ( " " @var{option} )* | |
24845 | @code{[} " --" @code{]} ( " " @var{parameter} )* @var{nl}} | |
24846 | ||
24847 | @item @var{token} @expansion{} | |
24848 | "any sequence of digits" | |
24849 | ||
24850 | @item @var{option} @expansion{} | |
24851 | @code{"-" @var{parameter} [ " " @var{parameter} ]} | |
24852 | ||
24853 | @item @var{parameter} @expansion{} | |
24854 | @code{@var{non-blank-sequence} | @var{c-string}} | |
24855 | ||
24856 | @item @var{operation} @expansion{} | |
24857 | @emph{any of the operations described in this chapter} | |
24858 | ||
24859 | @item @var{non-blank-sequence} @expansion{} | |
24860 | @emph{anything, provided it doesn't contain special characters such as | |
24861 | "-", @var{nl}, """ and of course " "} | |
24862 | ||
24863 | @item @var{c-string} @expansion{} | |
24864 | @code{""" @var{seven-bit-iso-c-string-content} """} | |
24865 | ||
24866 | @item @var{nl} @expansion{} | |
24867 | @code{CR | CR-LF} | |
24868 | @end table | |
24869 | ||
24870 | @noindent | |
24871 | Notes: | |
24872 | ||
24873 | @itemize @bullet | |
24874 | @item | |
24875 | The CLI commands are still handled by the @sc{mi} interpreter; their | |
24876 | output is described below. | |
24877 | ||
24878 | @item | |
24879 | The @code{@var{token}}, when present, is passed back when the command | |
24880 | finishes. | |
24881 | ||
24882 | @item | |
24883 | Some @sc{mi} commands accept optional arguments as part of the parameter | |
24884 | list. Each option is identified by a leading @samp{-} (dash) and may be | |
24885 | followed by an optional argument parameter. Options occur first in the | |
24886 | parameter list and can be delimited from normal parameters using | |
24887 | @samp{--} (this is useful when some parameters begin with a dash). | |
24888 | @end itemize | |
24889 | ||
24890 | Pragmatics: | |
24891 | ||
24892 | @itemize @bullet | |
24893 | @item | |
24894 | We want easy access to the existing CLI syntax (for debugging). | |
24895 | ||
24896 | @item | |
24897 | We want it to be easy to spot a @sc{mi} operation. | |
24898 | @end itemize | |
24899 | ||
24900 | @node GDB/MI Output Syntax | |
24901 | @subsection @sc{gdb/mi} Output Syntax | |
24902 | ||
24903 | @cindex output syntax of @sc{gdb/mi} | |
24904 | @cindex @sc{gdb/mi}, output syntax | |
24905 | The output from @sc{gdb/mi} consists of zero or more out-of-band records | |
24906 | followed, optionally, by a single result record. This result record | |
24907 | is for the most recent command. The sequence of output records is | |
594fe323 | 24908 | terminated by @samp{(gdb)}. |
922fbb7b AC |
24909 | |
24910 | If an input command was prefixed with a @code{@var{token}} then the | |
24911 | corresponding output for that command will also be prefixed by that same | |
24912 | @var{token}. | |
24913 | ||
24914 | @table @code | |
24915 | @item @var{output} @expansion{} | |
594fe323 | 24916 | @code{( @var{out-of-band-record} )* [ @var{result-record} ] "(gdb)" @var{nl}} |
922fbb7b AC |
24917 | |
24918 | @item @var{result-record} @expansion{} | |
24919 | @code{ [ @var{token} ] "^" @var{result-class} ( "," @var{result} )* @var{nl}} | |
24920 | ||
24921 | @item @var{out-of-band-record} @expansion{} | |
24922 | @code{@var{async-record} | @var{stream-record}} | |
24923 | ||
24924 | @item @var{async-record} @expansion{} | |
24925 | @code{@var{exec-async-output} | @var{status-async-output} | @var{notify-async-output}} | |
24926 | ||
24927 | @item @var{exec-async-output} @expansion{} | |
dcf106f3 | 24928 | @code{[ @var{token} ] "*" @var{async-output nl}} |
922fbb7b AC |
24929 | |
24930 | @item @var{status-async-output} @expansion{} | |
dcf106f3 | 24931 | @code{[ @var{token} ] "+" @var{async-output nl}} |
922fbb7b AC |
24932 | |
24933 | @item @var{notify-async-output} @expansion{} | |
dcf106f3 | 24934 | @code{[ @var{token} ] "=" @var{async-output nl}} |
922fbb7b AC |
24935 | |
24936 | @item @var{async-output} @expansion{} | |
dcf106f3 | 24937 | @code{@var{async-class} ( "," @var{result} )*} |
922fbb7b AC |
24938 | |
24939 | @item @var{result-class} @expansion{} | |
24940 | @code{"done" | "running" | "connected" | "error" | "exit"} | |
24941 | ||
24942 | @item @var{async-class} @expansion{} | |
24943 | @code{"stopped" | @var{others}} (where @var{others} will be added | |
24944 | depending on the needs---this is still in development). | |
24945 | ||
24946 | @item @var{result} @expansion{} | |
24947 | @code{ @var{variable} "=" @var{value}} | |
24948 | ||
24949 | @item @var{variable} @expansion{} | |
24950 | @code{ @var{string} } | |
24951 | ||
24952 | @item @var{value} @expansion{} | |
24953 | @code{ @var{const} | @var{tuple} | @var{list} } | |
24954 | ||
24955 | @item @var{const} @expansion{} | |
24956 | @code{@var{c-string}} | |
24957 | ||
24958 | @item @var{tuple} @expansion{} | |
24959 | @code{ "@{@}" | "@{" @var{result} ( "," @var{result} )* "@}" } | |
24960 | ||
24961 | @item @var{list} @expansion{} | |
24962 | @code{ "[]" | "[" @var{value} ( "," @var{value} )* "]" | "[" | |
24963 | @var{result} ( "," @var{result} )* "]" } | |
24964 | ||
24965 | @item @var{stream-record} @expansion{} | |
24966 | @code{@var{console-stream-output} | @var{target-stream-output} | @var{log-stream-output}} | |
24967 | ||
24968 | @item @var{console-stream-output} @expansion{} | |
dcf106f3 | 24969 | @code{"~" @var{c-string nl}} |
922fbb7b AC |
24970 | |
24971 | @item @var{target-stream-output} @expansion{} | |
dcf106f3 | 24972 | @code{"@@" @var{c-string nl}} |
922fbb7b AC |
24973 | |
24974 | @item @var{log-stream-output} @expansion{} | |
dcf106f3 | 24975 | @code{"&" @var{c-string nl}} |
922fbb7b AC |
24976 | |
24977 | @item @var{nl} @expansion{} | |
24978 | @code{CR | CR-LF} | |
24979 | ||
24980 | @item @var{token} @expansion{} | |
24981 | @emph{any sequence of digits}. | |
24982 | @end table | |
24983 | ||
24984 | @noindent | |
24985 | Notes: | |
24986 | ||
24987 | @itemize @bullet | |
24988 | @item | |
24989 | All output sequences end in a single line containing a period. | |
24990 | ||
24991 | @item | |
721c02de VP |
24992 | The @code{@var{token}} is from the corresponding request. Note that |
24993 | for all async output, while the token is allowed by the grammar and | |
24994 | may be output by future versions of @value{GDBN} for select async | |
24995 | output messages, it is generally omitted. Frontends should treat | |
24996 | all async output as reporting general changes in the state of the | |
24997 | target and there should be no need to associate async output to any | |
24998 | prior command. | |
922fbb7b AC |
24999 | |
25000 | @item | |
25001 | @cindex status output in @sc{gdb/mi} | |
25002 | @var{status-async-output} contains on-going status information about the | |
25003 | progress of a slow operation. It can be discarded. All status output is | |
25004 | prefixed by @samp{+}. | |
25005 | ||
25006 | @item | |
25007 | @cindex async output in @sc{gdb/mi} | |
25008 | @var{exec-async-output} contains asynchronous state change on the target | |
25009 | (stopped, started, disappeared). All async output is prefixed by | |
25010 | @samp{*}. | |
25011 | ||
25012 | @item | |
25013 | @cindex notify output in @sc{gdb/mi} | |
25014 | @var{notify-async-output} contains supplementary information that the | |
25015 | client should handle (e.g., a new breakpoint information). All notify | |
25016 | output is prefixed by @samp{=}. | |
25017 | ||
25018 | @item | |
25019 | @cindex console output in @sc{gdb/mi} | |
25020 | @var{console-stream-output} is output that should be displayed as is in the | |
25021 | console. It is the textual response to a CLI command. All the console | |
25022 | output is prefixed by @samp{~}. | |
25023 | ||
25024 | @item | |
25025 | @cindex target output in @sc{gdb/mi} | |
25026 | @var{target-stream-output} is the output produced by the target program. | |
25027 | All the target output is prefixed by @samp{@@}. | |
25028 | ||
25029 | @item | |
25030 | @cindex log output in @sc{gdb/mi} | |
25031 | @var{log-stream-output} is output text coming from @value{GDBN}'s internals, for | |
25032 | instance messages that should be displayed as part of an error log. All | |
25033 | the log output is prefixed by @samp{&}. | |
25034 | ||
25035 | @item | |
25036 | @cindex list output in @sc{gdb/mi} | |
25037 | New @sc{gdb/mi} commands should only output @var{lists} containing | |
25038 | @var{values}. | |
25039 | ||
25040 | ||
25041 | @end itemize | |
25042 | ||
25043 | @xref{GDB/MI Stream Records, , @sc{gdb/mi} Stream Records}, for more | |
25044 | details about the various output records. | |
25045 | ||
922fbb7b AC |
25046 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25047 | @node GDB/MI Compatibility with CLI | |
25048 | @section @sc{gdb/mi} Compatibility with CLI | |
25049 | ||
25050 | @cindex compatibility, @sc{gdb/mi} and CLI | |
25051 | @cindex @sc{gdb/mi}, compatibility with CLI | |
922fbb7b | 25052 | |
a2c02241 NR |
25053 | For the developers convenience CLI commands can be entered directly, |
25054 | but there may be some unexpected behaviour. For example, commands | |
25055 | that query the user will behave as if the user replied yes, breakpoint | |
25056 | command lists are not executed and some CLI commands, such as | |
25057 | @code{if}, @code{when} and @code{define}, prompt for further input with | |
25058 | @samp{>}, which is not valid MI output. | |
ef21caaf NR |
25059 | |
25060 | This feature may be removed at some stage in the future and it is | |
a2c02241 NR |
25061 | recommended that front ends use the @code{-interpreter-exec} command |
25062 | (@pxref{-interpreter-exec}). | |
922fbb7b | 25063 | |
af6eff6f NR |
25064 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25065 | @node GDB/MI Development and Front Ends | |
25066 | @section @sc{gdb/mi} Development and Front Ends | |
25067 | @cindex @sc{gdb/mi} development | |
25068 | ||
25069 | The application which takes the MI output and presents the state of the | |
25070 | program being debugged to the user is called a @dfn{front end}. | |
25071 | ||
25072 | Although @sc{gdb/mi} is still incomplete, it is currently being used | |
25073 | by a variety of front ends to @value{GDBN}. This makes it difficult | |
25074 | to introduce new functionality without breaking existing usage. This | |
25075 | section tries to minimize the problems by describing how the protocol | |
25076 | might change. | |
25077 | ||
25078 | Some changes in MI need not break a carefully designed front end, and | |
25079 | for these the MI version will remain unchanged. The following is a | |
25080 | list of changes that may occur within one level, so front ends should | |
25081 | parse MI output in a way that can handle them: | |
25082 | ||
25083 | @itemize @bullet | |
25084 | @item | |
25085 | New MI commands may be added. | |
25086 | ||
25087 | @item | |
25088 | New fields may be added to the output of any MI command. | |
25089 | ||
36ece8b3 NR |
25090 | @item |
25091 | The range of values for fields with specified values, e.g., | |
9f708cb2 | 25092 | @code{in_scope} (@pxref{-var-update}) may be extended. |
36ece8b3 | 25093 | |
af6eff6f NR |
25094 | @c The format of field's content e.g type prefix, may change so parse it |
25095 | @c at your own risk. Yes, in general? | |
25096 | ||
25097 | @c The order of fields may change? Shouldn't really matter but it might | |
25098 | @c resolve inconsistencies. | |
25099 | @end itemize | |
25100 | ||
25101 | If the changes are likely to break front ends, the MI version level | |
25102 | will be increased by one. This will allow the front end to parse the | |
25103 | output according to the MI version. Apart from mi0, new versions of | |
25104 | @value{GDBN} will not support old versions of MI and it will be the | |
25105 | responsibility of the front end to work with the new one. | |
25106 | ||
25107 | @c Starting with mi3, add a new command -mi-version that prints the MI | |
25108 | @c version? | |
25109 | ||
25110 | The best way to avoid unexpected changes in MI that might break your front | |
25111 | end is to make your project known to @value{GDBN} developers and | |
7a9a6b69 | 25112 | follow development on @email{gdb@@sourceware.org} and |
fa0f268d | 25113 | @email{gdb-patches@@sourceware.org}. |
af6eff6f NR |
25114 | @cindex mailing lists |
25115 | ||
922fbb7b AC |
25116 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25117 | @node GDB/MI Output Records | |
25118 | @section @sc{gdb/mi} Output Records | |
25119 | ||
25120 | @menu | |
25121 | * GDB/MI Result Records:: | |
25122 | * GDB/MI Stream Records:: | |
82f68b1c | 25123 | * GDB/MI Async Records:: |
54516a0b | 25124 | * GDB/MI Breakpoint Information:: |
c3b108f7 | 25125 | * GDB/MI Frame Information:: |
dc146f7c | 25126 | * GDB/MI Thread Information:: |
4368ebeb | 25127 | * GDB/MI Ada Exception Information:: |
922fbb7b AC |
25128 | @end menu |
25129 | ||
25130 | @node GDB/MI Result Records | |
25131 | @subsection @sc{gdb/mi} Result Records | |
25132 | ||
25133 | @cindex result records in @sc{gdb/mi} | |
25134 | @cindex @sc{gdb/mi}, result records | |
25135 | In addition to a number of out-of-band notifications, the response to a | |
25136 | @sc{gdb/mi} command includes one of the following result indications: | |
25137 | ||
25138 | @table @code | |
25139 | @findex ^done | |
25140 | @item "^done" [ "," @var{results} ] | |
25141 | The synchronous operation was successful, @code{@var{results}} are the return | |
25142 | values. | |
25143 | ||
25144 | @item "^running" | |
25145 | @findex ^running | |
8e9c5e02 VP |
25146 | This result record is equivalent to @samp{^done}. Historically, it |
25147 | was output instead of @samp{^done} if the command has resumed the | |
25148 | target. This behaviour is maintained for backward compatibility, but | |
25149 | all frontends should treat @samp{^done} and @samp{^running} | |
25150 | identically and rely on the @samp{*running} output record to determine | |
25151 | which threads are resumed. | |
922fbb7b | 25152 | |
ef21caaf NR |
25153 | @item "^connected" |
25154 | @findex ^connected | |
3f94c067 | 25155 | @value{GDBN} has connected to a remote target. |
ef21caaf | 25156 | |
2ea126fa | 25157 | @item "^error" "," "msg=" @var{c-string} [ "," "code=" @var{c-string} ] |
922fbb7b | 25158 | @findex ^error |
2ea126fa JB |
25159 | The operation failed. The @code{msg=@var{c-string}} variable contains |
25160 | the corresponding error message. | |
25161 | ||
25162 | If present, the @code{code=@var{c-string}} variable provides an error | |
25163 | code on which consumers can rely on to detect the corresponding | |
25164 | error condition. At present, only one error code is defined: | |
25165 | ||
25166 | @table @samp | |
25167 | @item "undefined-command" | |
25168 | Indicates that the command causing the error does not exist. | |
25169 | @end table | |
ef21caaf NR |
25170 | |
25171 | @item "^exit" | |
25172 | @findex ^exit | |
3f94c067 | 25173 | @value{GDBN} has terminated. |
ef21caaf | 25174 | |
922fbb7b AC |
25175 | @end table |
25176 | ||
25177 | @node GDB/MI Stream Records | |
25178 | @subsection @sc{gdb/mi} Stream Records | |
25179 | ||
25180 | @cindex @sc{gdb/mi}, stream records | |
25181 | @cindex stream records in @sc{gdb/mi} | |
25182 | @value{GDBN} internally maintains a number of output streams: the console, the | |
25183 | target, and the log. The output intended for each of these streams is | |
25184 | funneled through the @sc{gdb/mi} interface using @dfn{stream records}. | |
25185 | ||
25186 | Each stream record begins with a unique @dfn{prefix character} which | |
25187 | identifies its stream (@pxref{GDB/MI Output Syntax, , @sc{gdb/mi} Output | |
25188 | Syntax}). In addition to the prefix, each stream record contains a | |
25189 | @code{@var{string-output}}. This is either raw text (with an implicit new | |
25190 | line) or a quoted C string (which does not contain an implicit newline). | |
25191 | ||
25192 | @table @code | |
25193 | @item "~" @var{string-output} | |
25194 | The console output stream contains text that should be displayed in the | |
25195 | CLI console window. It contains the textual responses to CLI commands. | |
25196 | ||
25197 | @item "@@" @var{string-output} | |
25198 | The target output stream contains any textual output from the running | |
ef21caaf NR |
25199 | target. This is only present when GDB's event loop is truly |
25200 | asynchronous, which is currently only the case for remote targets. | |
922fbb7b AC |
25201 | |
25202 | @item "&" @var{string-output} | |
25203 | The log stream contains debugging messages being produced by @value{GDBN}'s | |
25204 | internals. | |
25205 | @end table | |
25206 | ||
82f68b1c VP |
25207 | @node GDB/MI Async Records |
25208 | @subsection @sc{gdb/mi} Async Records | |
922fbb7b | 25209 | |
82f68b1c VP |
25210 | @cindex async records in @sc{gdb/mi} |
25211 | @cindex @sc{gdb/mi}, async records | |
25212 | @dfn{Async} records are used to notify the @sc{gdb/mi} client of | |
922fbb7b | 25213 | additional changes that have occurred. Those changes can either be a |
82f68b1c | 25214 | consequence of @sc{gdb/mi} commands (e.g., a breakpoint modified) or a result of |
922fbb7b AC |
25215 | target activity (e.g., target stopped). |
25216 | ||
8eb41542 | 25217 | The following is the list of possible async records: |
922fbb7b AC |
25218 | |
25219 | @table @code | |
034dad6f | 25220 | |
e1ac3328 VP |
25221 | @item *running,thread-id="@var{thread}" |
25222 | The target is now running. The @var{thread} field tells which | |
25223 | specific thread is now running, and can be @samp{all} if all threads | |
25224 | are running. The frontend should assume that no interaction with a | |
25225 | running thread is possible after this notification is produced. | |
25226 | The frontend should not assume that this notification is output | |
25227 | only once for any command. @value{GDBN} may emit this notification | |
25228 | several times, either for different threads, because it cannot resume | |
25229 | all threads together, or even for a single thread, if the thread must | |
25230 | be stepped though some code before letting it run freely. | |
25231 | ||
dc146f7c | 25232 | @item *stopped,reason="@var{reason}",thread-id="@var{id}",stopped-threads="@var{stopped}",core="@var{core}" |
82f68b1c VP |
25233 | The target has stopped. The @var{reason} field can have one of the |
25234 | following values: | |
034dad6f BR |
25235 | |
25236 | @table @code | |
25237 | @item breakpoint-hit | |
25238 | A breakpoint was reached. | |
25239 | @item watchpoint-trigger | |
25240 | A watchpoint was triggered. | |
25241 | @item read-watchpoint-trigger | |
25242 | A read watchpoint was triggered. | |
25243 | @item access-watchpoint-trigger | |
25244 | An access watchpoint was triggered. | |
25245 | @item function-finished | |
25246 | An -exec-finish or similar CLI command was accomplished. | |
25247 | @item location-reached | |
25248 | An -exec-until or similar CLI command was accomplished. | |
25249 | @item watchpoint-scope | |
25250 | A watchpoint has gone out of scope. | |
25251 | @item end-stepping-range | |
25252 | An -exec-next, -exec-next-instruction, -exec-step, -exec-step-instruction or | |
25253 | similar CLI command was accomplished. | |
25254 | @item exited-signalled | |
25255 | The inferior exited because of a signal. | |
25256 | @item exited | |
25257 | The inferior exited. | |
25258 | @item exited-normally | |
25259 | The inferior exited normally. | |
25260 | @item signal-received | |
25261 | A signal was received by the inferior. | |
36dfb11c TT |
25262 | @item solib-event |
25263 | The inferior has stopped due to a library being loaded or unloaded. | |
edcc5120 TT |
25264 | This can happen when @code{stop-on-solib-events} (@pxref{Files}) is |
25265 | set or when a @code{catch load} or @code{catch unload} catchpoint is | |
25266 | in use (@pxref{Set Catchpoints}). | |
36dfb11c TT |
25267 | @item fork |
25268 | The inferior has forked. This is reported when @code{catch fork} | |
25269 | (@pxref{Set Catchpoints}) has been used. | |
25270 | @item vfork | |
25271 | The inferior has vforked. This is reported in when @code{catch vfork} | |
25272 | (@pxref{Set Catchpoints}) has been used. | |
25273 | @item syscall-entry | |
25274 | The inferior entered a system call. This is reported when @code{catch | |
25275 | syscall} (@pxref{Set Catchpoints}) has been used. | |
25276 | @item syscall-entry | |
25277 | The inferior returned from a system call. This is reported when | |
25278 | @code{catch syscall} (@pxref{Set Catchpoints}) has been used. | |
25279 | @item exec | |
25280 | The inferior called @code{exec}. This is reported when @code{catch exec} | |
25281 | (@pxref{Set Catchpoints}) has been used. | |
922fbb7b AC |
25282 | @end table |
25283 | ||
c3b108f7 VP |
25284 | The @var{id} field identifies the thread that directly caused the stop |
25285 | -- for example by hitting a breakpoint. Depending on whether all-stop | |
25286 | mode is in effect (@pxref{All-Stop Mode}), @value{GDBN} may either | |
25287 | stop all threads, or only the thread that directly triggered the stop. | |
25288 | If all threads are stopped, the @var{stopped} field will have the | |
25289 | value of @code{"all"}. Otherwise, the value of the @var{stopped} | |
25290 | field will be a list of thread identifiers. Presently, this list will | |
25291 | always include a single thread, but frontend should be prepared to see | |
dc146f7c VP |
25292 | several threads in the list. The @var{core} field reports the |
25293 | processor core on which the stop event has happened. This field may be absent | |
25294 | if such information is not available. | |
c3b108f7 | 25295 | |
a79b8f6e VP |
25296 | @item =thread-group-added,id="@var{id}" |
25297 | @itemx =thread-group-removed,id="@var{id}" | |
25298 | A thread group was either added or removed. The @var{id} field | |
25299 | contains the @value{GDBN} identifier of the thread group. When a thread | |
25300 | group is added, it generally might not be associated with a running | |
25301 | process. When a thread group is removed, its id becomes invalid and | |
25302 | cannot be used in any way. | |
25303 | ||
25304 | @item =thread-group-started,id="@var{id}",pid="@var{pid}" | |
25305 | A thread group became associated with a running program, | |
25306 | either because the program was just started or the thread group | |
25307 | was attached to a program. The @var{id} field contains the | |
25308 | @value{GDBN} identifier of the thread group. The @var{pid} field | |
25309 | contains process identifier, specific to the operating system. | |
25310 | ||
8cf64490 | 25311 | @item =thread-group-exited,id="@var{id}"[,exit-code="@var{code}"] |
a79b8f6e VP |
25312 | A thread group is no longer associated with a running program, |
25313 | either because the program has exited, or because it was detached | |
c3b108f7 | 25314 | from. The @var{id} field contains the @value{GDBN} identifier of the |
697aa1b7 | 25315 | thread group. The @var{code} field is the exit code of the inferior; it exists |
8cf64490 | 25316 | only when the inferior exited with some code. |
c3b108f7 VP |
25317 | |
25318 | @item =thread-created,id="@var{id}",group-id="@var{gid}" | |
25319 | @itemx =thread-exited,id="@var{id}",group-id="@var{gid}" | |
82f68b1c | 25320 | A thread either was created, or has exited. The @var{id} field |
c3b108f7 VP |
25321 | contains the @value{GDBN} identifier of the thread. The @var{gid} |
25322 | field identifies the thread group this thread belongs to. | |
66bb093b VP |
25323 | |
25324 | @item =thread-selected,id="@var{id}" | |
25325 | Informs that the selected thread was changed as result of the last | |
25326 | command. This notification is not emitted as result of @code{-thread-select} | |
25327 | command but is emitted whenever an MI command that is not documented | |
25328 | to change the selected thread actually changes it. In particular, | |
25329 | invoking, directly or indirectly (via user-defined command), the CLI | |
25330 | @code{thread} command, will generate this notification. | |
25331 | ||
25332 | We suggest that in response to this notification, front ends | |
25333 | highlight the selected thread and cause subsequent commands to apply to | |
25334 | that thread. | |
25335 | ||
c86cf029 VP |
25336 | @item =library-loaded,... |
25337 | Reports that a new library file was loaded by the program. This | |
25338 | notification has 4 fields---@var{id}, @var{target-name}, | |
134eb42c | 25339 | @var{host-name}, and @var{symbols-loaded}. The @var{id} field is an |
c86cf029 VP |
25340 | opaque identifier of the library. For remote debugging case, |
25341 | @var{target-name} and @var{host-name} fields give the name of the | |
134eb42c VP |
25342 | library file on the target, and on the host respectively. For native |
25343 | debugging, both those fields have the same value. The | |
f1cbe1d3 TT |
25344 | @var{symbols-loaded} field is emitted only for backward compatibility |
25345 | and should not be relied on to convey any useful information. The | |
25346 | @var{thread-group} field, if present, specifies the id of the thread | |
25347 | group in whose context the library was loaded. If the field is | |
25348 | absent, it means the library was loaded in the context of all present | |
25349 | thread groups. | |
c86cf029 VP |
25350 | |
25351 | @item =library-unloaded,... | |
134eb42c | 25352 | Reports that a library was unloaded by the program. This notification |
c86cf029 | 25353 | has 3 fields---@var{id}, @var{target-name} and @var{host-name} with |
a79b8f6e VP |
25354 | the same meaning as for the @code{=library-loaded} notification. |
25355 | The @var{thread-group} field, if present, specifies the id of the | |
25356 | thread group in whose context the library was unloaded. If the field is | |
25357 | absent, it means the library was unloaded in the context of all present | |
25358 | thread groups. | |
c86cf029 | 25359 | |
201b4506 YQ |
25360 | @item =traceframe-changed,num=@var{tfnum},tracepoint=@var{tpnum} |
25361 | @itemx =traceframe-changed,end | |
25362 | Reports that the trace frame was changed and its new number is | |
25363 | @var{tfnum}. The number of the tracepoint associated with this trace | |
25364 | frame is @var{tpnum}. | |
25365 | ||
134a2066 | 25366 | @item =tsv-created,name=@var{name},initial=@var{initial} |
bb25a15c | 25367 | Reports that the new trace state variable @var{name} is created with |
134a2066 | 25368 | initial value @var{initial}. |
bb25a15c YQ |
25369 | |
25370 | @item =tsv-deleted,name=@var{name} | |
25371 | @itemx =tsv-deleted | |
25372 | Reports that the trace state variable @var{name} is deleted or all | |
25373 | trace state variables are deleted. | |
25374 | ||
134a2066 YQ |
25375 | @item =tsv-modified,name=@var{name},initial=@var{initial}[,current=@var{current}] |
25376 | Reports that the trace state variable @var{name} is modified with | |
25377 | the initial value @var{initial}. The current value @var{current} of | |
25378 | trace state variable is optional and is reported if the current | |
25379 | value of trace state variable is known. | |
25380 | ||
8d3788bd VP |
25381 | @item =breakpoint-created,bkpt=@{...@} |
25382 | @itemx =breakpoint-modified,bkpt=@{...@} | |
d9f08f52 | 25383 | @itemx =breakpoint-deleted,id=@var{number} |
8d3788bd VP |
25384 | Reports that a breakpoint was created, modified, or deleted, |
25385 | respectively. Only user-visible breakpoints are reported to the MI | |
25386 | user. | |
25387 | ||
25388 | The @var{bkpt} argument is of the same form as returned by the various | |
d9f08f52 YQ |
25389 | breakpoint commands; @xref{GDB/MI Breakpoint Commands}. The |
25390 | @var{number} is the ordinal number of the breakpoint. | |
8d3788bd VP |
25391 | |
25392 | Note that if a breakpoint is emitted in the result record of a | |
25393 | command, then it will not also be emitted in an async record. | |
25394 | ||
82a90ccf YQ |
25395 | @item =record-started,thread-group="@var{id}" |
25396 | @itemx =record-stopped,thread-group="@var{id}" | |
25397 | Execution log recording was either started or stopped on an | |
25398 | inferior. The @var{id} is the @value{GDBN} identifier of the thread | |
25399 | group corresponding to the affected inferior. | |
25400 | ||
5b9afe8a YQ |
25401 | @item =cmd-param-changed,param=@var{param},value=@var{value} |
25402 | Reports that a parameter of the command @code{set @var{param}} is | |
25403 | changed to @var{value}. In the multi-word @code{set} command, | |
25404 | the @var{param} is the whole parameter list to @code{set} command. | |
25405 | For example, In command @code{set check type on}, @var{param} | |
25406 | is @code{check type} and @var{value} is @code{on}. | |
8de0566d YQ |
25407 | |
25408 | @item =memory-changed,thread-group=@var{id},addr=@var{addr},len=@var{len}[,type="code"] | |
25409 | Reports that bytes from @var{addr} to @var{data} + @var{len} were | |
25410 | written in an inferior. The @var{id} is the identifier of the | |
25411 | thread group corresponding to the affected inferior. The optional | |
25412 | @code{type="code"} part is reported if the memory written to holds | |
25413 | executable code. | |
82f68b1c VP |
25414 | @end table |
25415 | ||
54516a0b TT |
25416 | @node GDB/MI Breakpoint Information |
25417 | @subsection @sc{gdb/mi} Breakpoint Information | |
25418 | ||
25419 | When @value{GDBN} reports information about a breakpoint, a | |
25420 | tracepoint, a watchpoint, or a catchpoint, it uses a tuple with the | |
25421 | following fields: | |
25422 | ||
25423 | @table @code | |
25424 | @item number | |
25425 | The breakpoint number. For a breakpoint that represents one location | |
25426 | of a multi-location breakpoint, this will be a dotted pair, like | |
25427 | @samp{1.2}. | |
25428 | ||
25429 | @item type | |
25430 | The type of the breakpoint. For ordinary breakpoints this will be | |
25431 | @samp{breakpoint}, but many values are possible. | |
25432 | ||
8ac3646f TT |
25433 | @item catch-type |
25434 | If the type of the breakpoint is @samp{catchpoint}, then this | |
25435 | indicates the exact type of catchpoint. | |
25436 | ||
54516a0b TT |
25437 | @item disp |
25438 | This is the breakpoint disposition---either @samp{del}, meaning that | |
25439 | the breakpoint will be deleted at the next stop, or @samp{keep}, | |
25440 | meaning that the breakpoint will not be deleted. | |
25441 | ||
25442 | @item enabled | |
25443 | This indicates whether the breakpoint is enabled, in which case the | |
25444 | value is @samp{y}, or disabled, in which case the value is @samp{n}. | |
25445 | Note that this is not the same as the field @code{enable}. | |
25446 | ||
25447 | @item addr | |
25448 | The address of the breakpoint. This may be a hexidecimal number, | |
25449 | giving the address; or the string @samp{<PENDING>}, for a pending | |
25450 | breakpoint; or the string @samp{<MULTIPLE>}, for a breakpoint with | |
25451 | multiple locations. This field will not be present if no address can | |
25452 | be determined. For example, a watchpoint does not have an address. | |
25453 | ||
25454 | @item func | |
25455 | If known, the function in which the breakpoint appears. | |
25456 | If not known, this field is not present. | |
25457 | ||
25458 | @item filename | |
25459 | The name of the source file which contains this function, if known. | |
25460 | If not known, this field is not present. | |
25461 | ||
25462 | @item fullname | |
25463 | The full file name of the source file which contains this function, if | |
25464 | known. If not known, this field is not present. | |
25465 | ||
25466 | @item line | |
25467 | The line number at which this breakpoint appears, if known. | |
25468 | If not known, this field is not present. | |
25469 | ||
25470 | @item at | |
25471 | If the source file is not known, this field may be provided. If | |
25472 | provided, this holds the address of the breakpoint, possibly followed | |
25473 | by a symbol name. | |
25474 | ||
25475 | @item pending | |
25476 | If this breakpoint is pending, this field is present and holds the | |
25477 | text used to set the breakpoint, as entered by the user. | |
25478 | ||
25479 | @item evaluated-by | |
25480 | Where this breakpoint's condition is evaluated, either @samp{host} or | |
25481 | @samp{target}. | |
25482 | ||
25483 | @item thread | |
25484 | If this is a thread-specific breakpoint, then this identifies the | |
25485 | thread in which the breakpoint can trigger. | |
25486 | ||
25487 | @item task | |
25488 | If this breakpoint is restricted to a particular Ada task, then this | |
25489 | field will hold the task identifier. | |
25490 | ||
25491 | @item cond | |
25492 | If the breakpoint is conditional, this is the condition expression. | |
25493 | ||
25494 | @item ignore | |
25495 | The ignore count of the breakpoint. | |
25496 | ||
25497 | @item enable | |
25498 | The enable count of the breakpoint. | |
25499 | ||
25500 | @item traceframe-usage | |
25501 | FIXME. | |
25502 | ||
25503 | @item static-tracepoint-marker-string-id | |
25504 | For a static tracepoint, the name of the static tracepoint marker. | |
25505 | ||
25506 | @item mask | |
25507 | For a masked watchpoint, this is the mask. | |
25508 | ||
25509 | @item pass | |
25510 | A tracepoint's pass count. | |
25511 | ||
25512 | @item original-location | |
25513 | The location of the breakpoint as originally specified by the user. | |
25514 | This field is optional. | |
25515 | ||
25516 | @item times | |
25517 | The number of times the breakpoint has been hit. | |
25518 | ||
25519 | @item installed | |
25520 | This field is only given for tracepoints. This is either @samp{y}, | |
25521 | meaning that the tracepoint is installed, or @samp{n}, meaning that it | |
25522 | is not. | |
25523 | ||
25524 | @item what | |
25525 | Some extra data, the exact contents of which are type-dependent. | |
25526 | ||
25527 | @end table | |
25528 | ||
25529 | For example, here is what the output of @code{-break-insert} | |
25530 | (@pxref{GDB/MI Breakpoint Commands}) might be: | |
25531 | ||
25532 | @smallexample | |
25533 | -> -break-insert main | |
25534 | <- ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
25535 | enabled="y",addr="0x08048564",func="main",file="myprog.c", | |
998580f1 MK |
25536 | fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"], |
25537 | times="0"@} | |
54516a0b TT |
25538 | <- (gdb) |
25539 | @end smallexample | |
25540 | ||
c3b108f7 VP |
25541 | @node GDB/MI Frame Information |
25542 | @subsection @sc{gdb/mi} Frame Information | |
25543 | ||
25544 | Response from many MI commands includes an information about stack | |
25545 | frame. This information is a tuple that may have the following | |
25546 | fields: | |
25547 | ||
25548 | @table @code | |
25549 | @item level | |
25550 | The level of the stack frame. The innermost frame has the level of | |
25551 | zero. This field is always present. | |
25552 | ||
25553 | @item func | |
25554 | The name of the function corresponding to the frame. This field may | |
25555 | be absent if @value{GDBN} is unable to determine the function name. | |
25556 | ||
25557 | @item addr | |
25558 | The code address for the frame. This field is always present. | |
25559 | ||
25560 | @item file | |
25561 | The name of the source files that correspond to the frame's code | |
25562 | address. This field may be absent. | |
25563 | ||
25564 | @item line | |
25565 | The source line corresponding to the frames' code address. This field | |
25566 | may be absent. | |
25567 | ||
25568 | @item from | |
25569 | The name of the binary file (either executable or shared library) the | |
25570 | corresponds to the frame's code address. This field may be absent. | |
25571 | ||
25572 | @end table | |
82f68b1c | 25573 | |
dc146f7c VP |
25574 | @node GDB/MI Thread Information |
25575 | @subsection @sc{gdb/mi} Thread Information | |
25576 | ||
25577 | Whenever @value{GDBN} has to report an information about a thread, it | |
25578 | uses a tuple with the following fields: | |
25579 | ||
25580 | @table @code | |
25581 | @item id | |
25582 | The numeric id assigned to the thread by @value{GDBN}. This field is | |
25583 | always present. | |
25584 | ||
25585 | @item target-id | |
25586 | Target-specific string identifying the thread. This field is always present. | |
25587 | ||
25588 | @item details | |
25589 | Additional information about the thread provided by the target. | |
25590 | It is supposed to be human-readable and not interpreted by the | |
25591 | frontend. This field is optional. | |
25592 | ||
25593 | @item state | |
25594 | Either @samp{stopped} or @samp{running}, depending on whether the | |
25595 | thread is presently running. This field is always present. | |
25596 | ||
25597 | @item core | |
25598 | The value of this field is an integer number of the processor core the | |
25599 | thread was last seen on. This field is optional. | |
25600 | @end table | |
25601 | ||
956a9fb9 JB |
25602 | @node GDB/MI Ada Exception Information |
25603 | @subsection @sc{gdb/mi} Ada Exception Information | |
25604 | ||
25605 | Whenever a @code{*stopped} record is emitted because the program | |
25606 | stopped after hitting an exception catchpoint (@pxref{Set Catchpoints}), | |
25607 | @value{GDBN} provides the name of the exception that was raised via | |
25608 | the @code{exception-name} field. | |
922fbb7b | 25609 | |
ef21caaf NR |
25610 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25611 | @node GDB/MI Simple Examples | |
25612 | @section Simple Examples of @sc{gdb/mi} Interaction | |
25613 | @cindex @sc{gdb/mi}, simple examples | |
25614 | ||
25615 | This subsection presents several simple examples of interaction using | |
25616 | the @sc{gdb/mi} interface. In these examples, @samp{->} means that the | |
25617 | following line is passed to @sc{gdb/mi} as input, while @samp{<-} means | |
25618 | the output received from @sc{gdb/mi}. | |
25619 | ||
d3e8051b | 25620 | Note the line breaks shown in the examples are here only for |
ef21caaf NR |
25621 | readability, they don't appear in the real output. |
25622 | ||
79a6e687 | 25623 | @subheading Setting a Breakpoint |
ef21caaf NR |
25624 | |
25625 | Setting a breakpoint generates synchronous output which contains detailed | |
25626 | information of the breakpoint. | |
25627 | ||
25628 | @smallexample | |
25629 | -> -break-insert main | |
25630 | <- ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
25631 | enabled="y",addr="0x08048564",func="main",file="myprog.c", | |
998580f1 MK |
25632 | fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"], |
25633 | times="0"@} | |
ef21caaf NR |
25634 | <- (gdb) |
25635 | @end smallexample | |
25636 | ||
25637 | @subheading Program Execution | |
25638 | ||
25639 | Program execution generates asynchronous records and MI gives the | |
25640 | reason that execution stopped. | |
25641 | ||
25642 | @smallexample | |
25643 | -> -exec-run | |
25644 | <- ^running | |
25645 | <- (gdb) | |
a47ec5fe | 25646 | <- *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", |
ef21caaf NR |
25647 | frame=@{addr="0x08048564",func="main", |
25648 | args=[@{name="argc",value="1"@},@{name="argv",value="0xbfc4d4d4"@}], | |
25649 | file="myprog.c",fullname="/home/nickrob/myprog.c",line="68"@} | |
25650 | <- (gdb) | |
25651 | -> -exec-continue | |
25652 | <- ^running | |
25653 | <- (gdb) | |
25654 | <- *stopped,reason="exited-normally" | |
25655 | <- (gdb) | |
25656 | @end smallexample | |
25657 | ||
3f94c067 | 25658 | @subheading Quitting @value{GDBN} |
ef21caaf | 25659 | |
3f94c067 | 25660 | Quitting @value{GDBN} just prints the result class @samp{^exit}. |
ef21caaf NR |
25661 | |
25662 | @smallexample | |
25663 | -> (gdb) | |
25664 | <- -gdb-exit | |
25665 | <- ^exit | |
25666 | @end smallexample | |
25667 | ||
a6b29f87 VP |
25668 | Please note that @samp{^exit} is printed immediately, but it might |
25669 | take some time for @value{GDBN} to actually exit. During that time, @value{GDBN} | |
25670 | performs necessary cleanups, including killing programs being debugged | |
25671 | or disconnecting from debug hardware, so the frontend should wait till | |
25672 | @value{GDBN} exits and should only forcibly kill @value{GDBN} if it | |
25673 | fails to exit in reasonable time. | |
25674 | ||
a2c02241 | 25675 | @subheading A Bad Command |
ef21caaf NR |
25676 | |
25677 | Here's what happens if you pass a non-existent command: | |
25678 | ||
25679 | @smallexample | |
25680 | -> -rubbish | |
25681 | <- ^error,msg="Undefined MI command: rubbish" | |
594fe323 | 25682 | <- (gdb) |
ef21caaf NR |
25683 | @end smallexample |
25684 | ||
25685 | ||
922fbb7b AC |
25686 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25687 | @node GDB/MI Command Description Format | |
25688 | @section @sc{gdb/mi} Command Description Format | |
25689 | ||
25690 | The remaining sections describe blocks of commands. Each block of | |
25691 | commands is laid out in a fashion similar to this section. | |
25692 | ||
922fbb7b AC |
25693 | @subheading Motivation |
25694 | ||
25695 | The motivation for this collection of commands. | |
25696 | ||
25697 | @subheading Introduction | |
25698 | ||
25699 | A brief introduction to this collection of commands as a whole. | |
25700 | ||
25701 | @subheading Commands | |
25702 | ||
25703 | For each command in the block, the following is described: | |
25704 | ||
25705 | @subsubheading Synopsis | |
25706 | ||
25707 | @smallexample | |
25708 | -command @var{args}@dots{} | |
25709 | @end smallexample | |
25710 | ||
922fbb7b AC |
25711 | @subsubheading Result |
25712 | ||
265eeb58 | 25713 | @subsubheading @value{GDBN} Command |
922fbb7b | 25714 | |
265eeb58 | 25715 | The corresponding @value{GDBN} CLI command(s), if any. |
922fbb7b AC |
25716 | |
25717 | @subsubheading Example | |
25718 | ||
ef21caaf NR |
25719 | Example(s) formatted for readability. Some of the described commands have |
25720 | not been implemented yet and these are labeled N.A.@: (not available). | |
25721 | ||
25722 | ||
922fbb7b | 25723 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
ef21caaf NR |
25724 | @node GDB/MI Breakpoint Commands |
25725 | @section @sc{gdb/mi} Breakpoint Commands | |
922fbb7b AC |
25726 | |
25727 | @cindex breakpoint commands for @sc{gdb/mi} | |
25728 | @cindex @sc{gdb/mi}, breakpoint commands | |
25729 | This section documents @sc{gdb/mi} commands for manipulating | |
25730 | breakpoints. | |
25731 | ||
25732 | @subheading The @code{-break-after} Command | |
25733 | @findex -break-after | |
25734 | ||
25735 | @subsubheading Synopsis | |
25736 | ||
25737 | @smallexample | |
25738 | -break-after @var{number} @var{count} | |
25739 | @end smallexample | |
25740 | ||
25741 | The breakpoint number @var{number} is not in effect until it has been | |
25742 | hit @var{count} times. To see how this is reflected in the output of | |
25743 | the @samp{-break-list} command, see the description of the | |
25744 | @samp{-break-list} command below. | |
25745 | ||
25746 | @subsubheading @value{GDBN} Command | |
25747 | ||
25748 | The corresponding @value{GDBN} command is @samp{ignore}. | |
25749 | ||
25750 | @subsubheading Example | |
25751 | ||
25752 | @smallexample | |
594fe323 | 25753 | (gdb) |
922fbb7b | 25754 | -break-insert main |
a47ec5fe AR |
25755 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep", |
25756 | enabled="y",addr="0x000100d0",func="main",file="hello.c", | |
998580f1 MK |
25757 | fullname="/home/foo/hello.c",line="5",thread-groups=["i1"], |
25758 | times="0"@} | |
594fe323 | 25759 | (gdb) |
922fbb7b AC |
25760 | -break-after 1 3 |
25761 | ~ | |
25762 | ^done | |
594fe323 | 25763 | (gdb) |
922fbb7b AC |
25764 | -break-list |
25765 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25766 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25767 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25768 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25769 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25770 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25771 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25772 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 25773 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 25774 | line="5",thread-groups=["i1"],times="0",ignore="3"@}]@} |
594fe323 | 25775 | (gdb) |
922fbb7b AC |
25776 | @end smallexample |
25777 | ||
25778 | @ignore | |
25779 | @subheading The @code{-break-catch} Command | |
25780 | @findex -break-catch | |
48cb2d85 | 25781 | @end ignore |
922fbb7b AC |
25782 | |
25783 | @subheading The @code{-break-commands} Command | |
25784 | @findex -break-commands | |
922fbb7b | 25785 | |
48cb2d85 VP |
25786 | @subsubheading Synopsis |
25787 | ||
25788 | @smallexample | |
25789 | -break-commands @var{number} [ @var{command1} ... @var{commandN} ] | |
25790 | @end smallexample | |
25791 | ||
25792 | Specifies the CLI commands that should be executed when breakpoint | |
25793 | @var{number} is hit. The parameters @var{command1} to @var{commandN} | |
25794 | are the commands. If no command is specified, any previously-set | |
25795 | commands are cleared. @xref{Break Commands}. Typical use of this | |
25796 | functionality is tracing a program, that is, printing of values of | |
25797 | some variables whenever breakpoint is hit and then continuing. | |
25798 | ||
25799 | @subsubheading @value{GDBN} Command | |
25800 | ||
25801 | The corresponding @value{GDBN} command is @samp{commands}. | |
25802 | ||
25803 | @subsubheading Example | |
25804 | ||
25805 | @smallexample | |
25806 | (gdb) | |
25807 | -break-insert main | |
25808 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
25809 | enabled="y",addr="0x000100d0",func="main",file="hello.c", | |
998580f1 MK |
25810 | fullname="/home/foo/hello.c",line="5",thread-groups=["i1"], |
25811 | times="0"@} | |
48cb2d85 VP |
25812 | (gdb) |
25813 | -break-commands 1 "print v" "continue" | |
25814 | ^done | |
25815 | (gdb) | |
25816 | @end smallexample | |
922fbb7b AC |
25817 | |
25818 | @subheading The @code{-break-condition} Command | |
25819 | @findex -break-condition | |
25820 | ||
25821 | @subsubheading Synopsis | |
25822 | ||
25823 | @smallexample | |
25824 | -break-condition @var{number} @var{expr} | |
25825 | @end smallexample | |
25826 | ||
25827 | Breakpoint @var{number} will stop the program only if the condition in | |
25828 | @var{expr} is true. The condition becomes part of the | |
25829 | @samp{-break-list} output (see the description of the @samp{-break-list} | |
25830 | command below). | |
25831 | ||
25832 | @subsubheading @value{GDBN} Command | |
25833 | ||
25834 | The corresponding @value{GDBN} command is @samp{condition}. | |
25835 | ||
25836 | @subsubheading Example | |
25837 | ||
25838 | @smallexample | |
594fe323 | 25839 | (gdb) |
922fbb7b AC |
25840 | -break-condition 1 1 |
25841 | ^done | |
594fe323 | 25842 | (gdb) |
922fbb7b AC |
25843 | -break-list |
25844 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25845 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25846 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25847 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25848 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25849 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25850 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25851 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 25852 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 25853 | line="5",cond="1",thread-groups=["i1"],times="0",ignore="3"@}]@} |
594fe323 | 25854 | (gdb) |
922fbb7b AC |
25855 | @end smallexample |
25856 | ||
25857 | @subheading The @code{-break-delete} Command | |
25858 | @findex -break-delete | |
25859 | ||
25860 | @subsubheading Synopsis | |
25861 | ||
25862 | @smallexample | |
25863 | -break-delete ( @var{breakpoint} )+ | |
25864 | @end smallexample | |
25865 | ||
25866 | Delete the breakpoint(s) whose number(s) are specified in the argument | |
25867 | list. This is obviously reflected in the breakpoint list. | |
25868 | ||
79a6e687 | 25869 | @subsubheading @value{GDBN} Command |
922fbb7b AC |
25870 | |
25871 | The corresponding @value{GDBN} command is @samp{delete}. | |
25872 | ||
25873 | @subsubheading Example | |
25874 | ||
25875 | @smallexample | |
594fe323 | 25876 | (gdb) |
922fbb7b AC |
25877 | -break-delete 1 |
25878 | ^done | |
594fe323 | 25879 | (gdb) |
922fbb7b AC |
25880 | -break-list |
25881 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
25882 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25883 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25884 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25885 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25886 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25887 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25888 | body=[]@} | |
594fe323 | 25889 | (gdb) |
922fbb7b AC |
25890 | @end smallexample |
25891 | ||
25892 | @subheading The @code{-break-disable} Command | |
25893 | @findex -break-disable | |
25894 | ||
25895 | @subsubheading Synopsis | |
25896 | ||
25897 | @smallexample | |
25898 | -break-disable ( @var{breakpoint} )+ | |
25899 | @end smallexample | |
25900 | ||
25901 | Disable the named @var{breakpoint}(s). The field @samp{enabled} in the | |
25902 | break list is now set to @samp{n} for the named @var{breakpoint}(s). | |
25903 | ||
25904 | @subsubheading @value{GDBN} Command | |
25905 | ||
25906 | The corresponding @value{GDBN} command is @samp{disable}. | |
25907 | ||
25908 | @subsubheading Example | |
25909 | ||
25910 | @smallexample | |
594fe323 | 25911 | (gdb) |
922fbb7b AC |
25912 | -break-disable 2 |
25913 | ^done | |
594fe323 | 25914 | (gdb) |
922fbb7b AC |
25915 | -break-list |
25916 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25917 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25918 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25919 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25920 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25921 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25922 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25923 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="n", | |
948d5102 | 25924 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 25925 | line="5",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 25926 | (gdb) |
922fbb7b AC |
25927 | @end smallexample |
25928 | ||
25929 | @subheading The @code{-break-enable} Command | |
25930 | @findex -break-enable | |
25931 | ||
25932 | @subsubheading Synopsis | |
25933 | ||
25934 | @smallexample | |
25935 | -break-enable ( @var{breakpoint} )+ | |
25936 | @end smallexample | |
25937 | ||
25938 | Enable (previously disabled) @var{breakpoint}(s). | |
25939 | ||
25940 | @subsubheading @value{GDBN} Command | |
25941 | ||
25942 | The corresponding @value{GDBN} command is @samp{enable}. | |
25943 | ||
25944 | @subsubheading Example | |
25945 | ||
25946 | @smallexample | |
594fe323 | 25947 | (gdb) |
922fbb7b AC |
25948 | -break-enable 2 |
25949 | ^done | |
594fe323 | 25950 | (gdb) |
922fbb7b AC |
25951 | -break-list |
25952 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25953 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25954 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25955 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25956 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25957 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25958 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25959 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 25960 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 25961 | line="5",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 25962 | (gdb) |
922fbb7b AC |
25963 | @end smallexample |
25964 | ||
25965 | @subheading The @code{-break-info} Command | |
25966 | @findex -break-info | |
25967 | ||
25968 | @subsubheading Synopsis | |
25969 | ||
25970 | @smallexample | |
25971 | -break-info @var{breakpoint} | |
25972 | @end smallexample | |
25973 | ||
25974 | @c REDUNDANT??? | |
25975 | Get information about a single breakpoint. | |
25976 | ||
54516a0b TT |
25977 | The result is a table of breakpoints. @xref{GDB/MI Breakpoint |
25978 | Information}, for details on the format of each breakpoint in the | |
25979 | table. | |
25980 | ||
79a6e687 | 25981 | @subsubheading @value{GDBN} Command |
922fbb7b AC |
25982 | |
25983 | The corresponding @value{GDBN} command is @samp{info break @var{breakpoint}}. | |
25984 | ||
25985 | @subsubheading Example | |
25986 | N.A. | |
25987 | ||
25988 | @subheading The @code{-break-insert} Command | |
25989 | @findex -break-insert | |
25990 | ||
25991 | @subsubheading Synopsis | |
25992 | ||
25993 | @smallexample | |
18148017 | 25994 | -break-insert [ -t ] [ -h ] [ -f ] [ -d ] [ -a ] |
922fbb7b | 25995 | [ -c @var{condition} ] [ -i @var{ignore-count} ] |
472a2379 | 25996 | [ -p @var{thread-id} ] [ @var{location} ] |
922fbb7b AC |
25997 | @end smallexample |
25998 | ||
25999 | @noindent | |
afe8ab22 | 26000 | If specified, @var{location}, can be one of: |
922fbb7b AC |
26001 | |
26002 | @itemize @bullet | |
26003 | @item function | |
26004 | @c @item +offset | |
26005 | @c @item -offset | |
26006 | @c @item linenum | |
26007 | @item filename:linenum | |
26008 | @item filename:function | |
26009 | @item *address | |
26010 | @end itemize | |
26011 | ||
26012 | The possible optional parameters of this command are: | |
26013 | ||
26014 | @table @samp | |
26015 | @item -t | |
948d5102 | 26016 | Insert a temporary breakpoint. |
922fbb7b AC |
26017 | @item -h |
26018 | Insert a hardware breakpoint. | |
afe8ab22 VP |
26019 | @item -f |
26020 | If @var{location} cannot be parsed (for example if it | |
26021 | refers to unknown files or functions), create a pending | |
26022 | breakpoint. Without this flag, @value{GDBN} will report | |
26023 | an error, and won't create a breakpoint, if @var{location} | |
26024 | cannot be parsed. | |
41447f92 VP |
26025 | @item -d |
26026 | Create a disabled breakpoint. | |
18148017 VP |
26027 | @item -a |
26028 | Create a tracepoint. @xref{Tracepoints}. When this parameter | |
26029 | is used together with @samp{-h}, a fast tracepoint is created. | |
472a2379 KS |
26030 | @item -c @var{condition} |
26031 | Make the breakpoint conditional on @var{condition}. | |
26032 | @item -i @var{ignore-count} | |
26033 | Initialize the @var{ignore-count}. | |
26034 | @item -p @var{thread-id} | |
26035 | Restrict the breakpoint to the specified @var{thread-id}. | |
922fbb7b AC |
26036 | @end table |
26037 | ||
26038 | @subsubheading Result | |
26039 | ||
54516a0b TT |
26040 | @xref{GDB/MI Breakpoint Information}, for details on the format of the |
26041 | resulting breakpoint. | |
922fbb7b AC |
26042 | |
26043 | Note: this format is open to change. | |
26044 | @c An out-of-band breakpoint instead of part of the result? | |
26045 | ||
26046 | @subsubheading @value{GDBN} Command | |
26047 | ||
26048 | The corresponding @value{GDBN} commands are @samp{break}, @samp{tbreak}, | |
496ee73e | 26049 | @samp{hbreak}, and @samp{thbreak}. @c and @samp{rbreak}. |
922fbb7b AC |
26050 | |
26051 | @subsubheading Example | |
26052 | ||
26053 | @smallexample | |
594fe323 | 26054 | (gdb) |
922fbb7b | 26055 | -break-insert main |
948d5102 | 26056 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c", |
998580f1 MK |
26057 | fullname="/home/foo/recursive2.c,line="4",thread-groups=["i1"], |
26058 | times="0"@} | |
594fe323 | 26059 | (gdb) |
922fbb7b | 26060 | -break-insert -t foo |
948d5102 | 26061 | ^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c", |
998580f1 MK |
26062 | fullname="/home/foo/recursive2.c,line="11",thread-groups=["i1"], |
26063 | times="0"@} | |
594fe323 | 26064 | (gdb) |
922fbb7b AC |
26065 | -break-list |
26066 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
26067 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26068 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26069 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26070 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26071 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26072 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26073 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 26074 | addr="0x0001072c", func="main",file="recursive2.c", |
998580f1 MK |
26075 | fullname="/home/foo/recursive2.c,"line="4",thread-groups=["i1"], |
26076 | times="0"@}, | |
922fbb7b | 26077 | bkpt=@{number="2",type="breakpoint",disp="del",enabled="y", |
948d5102 | 26078 | addr="0x00010774",func="foo",file="recursive2.c", |
998580f1 MK |
26079 | fullname="/home/foo/recursive2.c",line="11",thread-groups=["i1"], |
26080 | times="0"@}]@} | |
594fe323 | 26081 | (gdb) |
496ee73e KS |
26082 | @c -break-insert -r foo.* |
26083 | @c ~int foo(int, int); | |
26084 | @c ^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c, | |
998580f1 MK |
26085 | @c "fullname="/home/foo/recursive2.c",line="11",thread-groups=["i1"], |
26086 | @c times="0"@} | |
496ee73e | 26087 | @c (gdb) |
922fbb7b AC |
26088 | @end smallexample |
26089 | ||
c5867ab6 HZ |
26090 | @subheading The @code{-dprintf-insert} Command |
26091 | @findex -dprintf-insert | |
26092 | ||
26093 | @subsubheading Synopsis | |
26094 | ||
26095 | @smallexample | |
26096 | -dprintf-insert [ -t ] [ -f ] [ -d ] | |
26097 | [ -c @var{condition} ] [ -i @var{ignore-count} ] | |
26098 | [ -p @var{thread-id} ] [ @var{location} ] [ @var{format} ] | |
26099 | [ @var{argument} ] | |
26100 | @end smallexample | |
26101 | ||
26102 | @noindent | |
26103 | If specified, @var{location}, can be one of: | |
26104 | ||
26105 | @itemize @bullet | |
26106 | @item @var{function} | |
26107 | @c @item +offset | |
26108 | @c @item -offset | |
26109 | @c @item @var{linenum} | |
26110 | @item @var{filename}:@var{linenum} | |
26111 | @item @var{filename}:function | |
26112 | @item *@var{address} | |
26113 | @end itemize | |
26114 | ||
26115 | The possible optional parameters of this command are: | |
26116 | ||
26117 | @table @samp | |
26118 | @item -t | |
26119 | Insert a temporary breakpoint. | |
26120 | @item -f | |
26121 | If @var{location} cannot be parsed (for example, if it | |
26122 | refers to unknown files or functions), create a pending | |
26123 | breakpoint. Without this flag, @value{GDBN} will report | |
26124 | an error, and won't create a breakpoint, if @var{location} | |
26125 | cannot be parsed. | |
26126 | @item -d | |
26127 | Create a disabled breakpoint. | |
26128 | @item -c @var{condition} | |
26129 | Make the breakpoint conditional on @var{condition}. | |
26130 | @item -i @var{ignore-count} | |
26131 | Set the ignore count of the breakpoint (@pxref{Conditions, ignore count}) | |
26132 | to @var{ignore-count}. | |
26133 | @item -p @var{thread-id} | |
26134 | Restrict the breakpoint to the specified @var{thread-id}. | |
26135 | @end table | |
26136 | ||
26137 | @subsubheading Result | |
26138 | ||
26139 | @xref{GDB/MI Breakpoint Information}, for details on the format of the | |
26140 | resulting breakpoint. | |
26141 | ||
26142 | @c An out-of-band breakpoint instead of part of the result? | |
26143 | ||
26144 | @subsubheading @value{GDBN} Command | |
26145 | ||
26146 | The corresponding @value{GDBN} command is @samp{dprintf}. | |
26147 | ||
26148 | @subsubheading Example | |
26149 | ||
26150 | @smallexample | |
26151 | (gdb) | |
26152 | 4-dprintf-insert foo "At foo entry\n" | |
26153 | 4^done,bkpt=@{number="1",type="dprintf",disp="keep",enabled="y", | |
26154 | addr="0x000000000040061b",func="foo",file="mi-dprintf.c", | |
26155 | fullname="mi-dprintf.c",line="25",thread-groups=["i1"], | |
26156 | times="0",script=@{"printf \"At foo entry\\n\"","continue"@}, | |
26157 | original-location="foo"@} | |
26158 | (gdb) | |
26159 | 5-dprintf-insert 26 "arg=%d, g=%d\n" arg g | |
26160 | 5^done,bkpt=@{number="2",type="dprintf",disp="keep",enabled="y", | |
26161 | addr="0x000000000040062a",func="foo",file="mi-dprintf.c", | |
26162 | fullname="mi-dprintf.c",line="26",thread-groups=["i1"], | |
26163 | times="0",script=@{"printf \"arg=%d, g=%d\\n\", arg, g","continue"@}, | |
26164 | original-location="mi-dprintf.c:26"@} | |
26165 | (gdb) | |
26166 | @end smallexample | |
26167 | ||
922fbb7b AC |
26168 | @subheading The @code{-break-list} Command |
26169 | @findex -break-list | |
26170 | ||
26171 | @subsubheading Synopsis | |
26172 | ||
26173 | @smallexample | |
26174 | -break-list | |
26175 | @end smallexample | |
26176 | ||
26177 | Displays the list of inserted breakpoints, showing the following fields: | |
26178 | ||
26179 | @table @samp | |
26180 | @item Number | |
26181 | number of the breakpoint | |
26182 | @item Type | |
26183 | type of the breakpoint: @samp{breakpoint} or @samp{watchpoint} | |
26184 | @item Disposition | |
26185 | should the breakpoint be deleted or disabled when it is hit: @samp{keep} | |
26186 | or @samp{nokeep} | |
26187 | @item Enabled | |
26188 | is the breakpoint enabled or no: @samp{y} or @samp{n} | |
26189 | @item Address | |
26190 | memory location at which the breakpoint is set | |
26191 | @item What | |
26192 | logical location of the breakpoint, expressed by function name, file | |
26193 | name, line number | |
998580f1 MK |
26194 | @item Thread-groups |
26195 | list of thread groups to which this breakpoint applies | |
922fbb7b AC |
26196 | @item Times |
26197 | number of times the breakpoint has been hit | |
26198 | @end table | |
26199 | ||
26200 | If there are no breakpoints or watchpoints, the @code{BreakpointTable} | |
26201 | @code{body} field is an empty list. | |
26202 | ||
26203 | @subsubheading @value{GDBN} Command | |
26204 | ||
26205 | The corresponding @value{GDBN} command is @samp{info break}. | |
26206 | ||
26207 | @subsubheading Example | |
26208 | ||
26209 | @smallexample | |
594fe323 | 26210 | (gdb) |
922fbb7b AC |
26211 | -break-list |
26212 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
26213 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26214 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26215 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26216 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26217 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26218 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26219 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
998580f1 MK |
26220 | addr="0x000100d0",func="main",file="hello.c",line="5",thread-groups=["i1"], |
26221 | times="0"@}, | |
922fbb7b | 26222 | bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", |
948d5102 | 26223 | addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 26224 | line="13",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 26225 | (gdb) |
922fbb7b AC |
26226 | @end smallexample |
26227 | ||
26228 | Here's an example of the result when there are no breakpoints: | |
26229 | ||
26230 | @smallexample | |
594fe323 | 26231 | (gdb) |
922fbb7b AC |
26232 | -break-list |
26233 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
26234 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26235 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26236 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26237 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26238 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26239 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26240 | body=[]@} | |
594fe323 | 26241 | (gdb) |
922fbb7b AC |
26242 | @end smallexample |
26243 | ||
18148017 VP |
26244 | @subheading The @code{-break-passcount} Command |
26245 | @findex -break-passcount | |
26246 | ||
26247 | @subsubheading Synopsis | |
26248 | ||
26249 | @smallexample | |
26250 | -break-passcount @var{tracepoint-number} @var{passcount} | |
26251 | @end smallexample | |
26252 | ||
26253 | Set the passcount for tracepoint @var{tracepoint-number} to | |
26254 | @var{passcount}. If the breakpoint referred to by @var{tracepoint-number} | |
26255 | is not a tracepoint, error is emitted. This corresponds to CLI | |
26256 | command @samp{passcount}. | |
26257 | ||
922fbb7b AC |
26258 | @subheading The @code{-break-watch} Command |
26259 | @findex -break-watch | |
26260 | ||
26261 | @subsubheading Synopsis | |
26262 | ||
26263 | @smallexample | |
26264 | -break-watch [ -a | -r ] | |
26265 | @end smallexample | |
26266 | ||
26267 | Create a watchpoint. With the @samp{-a} option it will create an | |
d3e8051b | 26268 | @dfn{access} watchpoint, i.e., a watchpoint that triggers either on a |
922fbb7b | 26269 | read from or on a write to the memory location. With the @samp{-r} |
d3e8051b | 26270 | option, the watchpoint created is a @dfn{read} watchpoint, i.e., it will |
922fbb7b AC |
26271 | trigger only when the memory location is accessed for reading. Without |
26272 | either of the options, the watchpoint created is a regular watchpoint, | |
d3e8051b | 26273 | i.e., it will trigger when the memory location is accessed for writing. |
79a6e687 | 26274 | @xref{Set Watchpoints, , Setting Watchpoints}. |
922fbb7b AC |
26275 | |
26276 | Note that @samp{-break-list} will report a single list of watchpoints and | |
26277 | breakpoints inserted. | |
26278 | ||
26279 | @subsubheading @value{GDBN} Command | |
26280 | ||
26281 | The corresponding @value{GDBN} commands are @samp{watch}, @samp{awatch}, and | |
26282 | @samp{rwatch}. | |
26283 | ||
26284 | @subsubheading Example | |
26285 | ||
26286 | Setting a watchpoint on a variable in the @code{main} function: | |
26287 | ||
26288 | @smallexample | |
594fe323 | 26289 | (gdb) |
922fbb7b AC |
26290 | -break-watch x |
26291 | ^done,wpt=@{number="2",exp="x"@} | |
594fe323 | 26292 | (gdb) |
922fbb7b AC |
26293 | -exec-continue |
26294 | ^running | |
0869d01b NR |
26295 | (gdb) |
26296 | *stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@}, | |
922fbb7b | 26297 | value=@{old="-268439212",new="55"@}, |
76ff342d | 26298 | frame=@{func="main",args=[],file="recursive2.c", |
948d5102 | 26299 | fullname="/home/foo/bar/recursive2.c",line="5"@} |
594fe323 | 26300 | (gdb) |
922fbb7b AC |
26301 | @end smallexample |
26302 | ||
26303 | Setting a watchpoint on a variable local to a function. @value{GDBN} will stop | |
26304 | the program execution twice: first for the variable changing value, then | |
26305 | for the watchpoint going out of scope. | |
26306 | ||
26307 | @smallexample | |
594fe323 | 26308 | (gdb) |
922fbb7b AC |
26309 | -break-watch C |
26310 | ^done,wpt=@{number="5",exp="C"@} | |
594fe323 | 26311 | (gdb) |
922fbb7b AC |
26312 | -exec-continue |
26313 | ^running | |
0869d01b NR |
26314 | (gdb) |
26315 | *stopped,reason="watchpoint-trigger", | |
922fbb7b AC |
26316 | wpt=@{number="5",exp="C"@},value=@{old="-276895068",new="3"@}, |
26317 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
26318 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
26319 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
594fe323 | 26320 | (gdb) |
922fbb7b AC |
26321 | -exec-continue |
26322 | ^running | |
0869d01b NR |
26323 | (gdb) |
26324 | *stopped,reason="watchpoint-scope",wpnum="5", | |
922fbb7b AC |
26325 | frame=@{func="callee3",args=[@{name="strarg", |
26326 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
26327 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
26328 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 26329 | (gdb) |
922fbb7b AC |
26330 | @end smallexample |
26331 | ||
26332 | Listing breakpoints and watchpoints, at different points in the program | |
26333 | execution. Note that once the watchpoint goes out of scope, it is | |
26334 | deleted. | |
26335 | ||
26336 | @smallexample | |
594fe323 | 26337 | (gdb) |
922fbb7b AC |
26338 | -break-watch C |
26339 | ^done,wpt=@{number="2",exp="C"@} | |
594fe323 | 26340 | (gdb) |
922fbb7b AC |
26341 | -break-list |
26342 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
26343 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26344 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26345 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26346 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26347 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26348 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26349 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
26350 | addr="0x00010734",func="callee4", | |
948d5102 | 26351 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
998580f1 MK |
26352 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",thread-groups=["i1"], |
26353 | times="1"@}, | |
922fbb7b | 26354 | bkpt=@{number="2",type="watchpoint",disp="keep", |
998580f1 | 26355 | enabled="y",addr="",what="C",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 26356 | (gdb) |
922fbb7b AC |
26357 | -exec-continue |
26358 | ^running | |
0869d01b NR |
26359 | (gdb) |
26360 | *stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="C"@}, | |
922fbb7b AC |
26361 | value=@{old="-276895068",new="3"@}, |
26362 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
26363 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
26364 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
594fe323 | 26365 | (gdb) |
922fbb7b AC |
26366 | -break-list |
26367 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
26368 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26369 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26370 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26371 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26372 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26373 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26374 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
26375 | addr="0x00010734",func="callee4", | |
948d5102 | 26376 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
998580f1 MK |
26377 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",thread-groups=["i1"], |
26378 | times="1"@}, | |
922fbb7b | 26379 | bkpt=@{number="2",type="watchpoint",disp="keep", |
998580f1 | 26380 | enabled="y",addr="",what="C",thread-groups=["i1"],times="-5"@}]@} |
594fe323 | 26381 | (gdb) |
922fbb7b AC |
26382 | -exec-continue |
26383 | ^running | |
26384 | ^done,reason="watchpoint-scope",wpnum="2", | |
26385 | frame=@{func="callee3",args=[@{name="strarg", | |
26386 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
26387 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
26388 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 26389 | (gdb) |
922fbb7b AC |
26390 | -break-list |
26391 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
26392 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26393 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26394 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26395 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26396 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26397 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26398 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
26399 | addr="0x00010734",func="callee4", | |
948d5102 NR |
26400 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
26401 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8", | |
998580f1 | 26402 | thread-groups=["i1"],times="1"@}]@} |
594fe323 | 26403 | (gdb) |
922fbb7b AC |
26404 | @end smallexample |
26405 | ||
3fa7bf06 MG |
26406 | |
26407 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
26408 | @node GDB/MI Catchpoint Commands | |
26409 | @section @sc{gdb/mi} Catchpoint Commands | |
26410 | ||
26411 | This section documents @sc{gdb/mi} commands for manipulating | |
26412 | catchpoints. | |
26413 | ||
40555925 JB |
26414 | @menu |
26415 | * Shared Library GDB/MI Catchpoint Commands:: | |
26416 | * Ada Exception GDB/MI Catchpoint Commands:: | |
26417 | @end menu | |
26418 | ||
26419 | @node Shared Library GDB/MI Catchpoint Commands | |
26420 | @subsection Shared Library @sc{gdb/mi} Catchpoints | |
26421 | ||
3fa7bf06 MG |
26422 | @subheading The @code{-catch-load} Command |
26423 | @findex -catch-load | |
26424 | ||
26425 | @subsubheading Synopsis | |
26426 | ||
26427 | @smallexample | |
26428 | -catch-load [ -t ] [ -d ] @var{regexp} | |
26429 | @end smallexample | |
26430 | ||
26431 | Add a catchpoint for library load events. If the @samp{-t} option is used, | |
26432 | the catchpoint is a temporary one (@pxref{Set Breaks, ,Setting | |
26433 | Breakpoints}). If the @samp{-d} option is used, the catchpoint is created | |
26434 | in a disabled state. The @samp{regexp} argument is a regular | |
26435 | expression used to match the name of the loaded library. | |
26436 | ||
26437 | ||
26438 | @subsubheading @value{GDBN} Command | |
26439 | ||
26440 | The corresponding @value{GDBN} command is @samp{catch load}. | |
26441 | ||
26442 | @subsubheading Example | |
26443 | ||
26444 | @smallexample | |
26445 | -catch-load -t foo.so | |
26446 | ^done,bkpt=@{number="1",type="catchpoint",disp="del",enabled="y", | |
8ac3646f | 26447 | what="load of library matching foo.so",catch-type="load",times="0"@} |
3fa7bf06 MG |
26448 | (gdb) |
26449 | @end smallexample | |
26450 | ||
26451 | ||
26452 | @subheading The @code{-catch-unload} Command | |
26453 | @findex -catch-unload | |
26454 | ||
26455 | @subsubheading Synopsis | |
26456 | ||
26457 | @smallexample | |
26458 | -catch-unload [ -t ] [ -d ] @var{regexp} | |
26459 | @end smallexample | |
26460 | ||
26461 | Add a catchpoint for library unload events. If the @samp{-t} option is | |
26462 | used, the catchpoint is a temporary one (@pxref{Set Breaks, ,Setting | |
26463 | Breakpoints}). If the @samp{-d} option is used, the catchpoint is | |
26464 | created in a disabled state. The @samp{regexp} argument is a regular | |
26465 | expression used to match the name of the unloaded library. | |
26466 | ||
26467 | @subsubheading @value{GDBN} Command | |
26468 | ||
26469 | The corresponding @value{GDBN} command is @samp{catch unload}. | |
26470 | ||
26471 | @subsubheading Example | |
26472 | ||
26473 | @smallexample | |
26474 | -catch-unload -d bar.so | |
26475 | ^done,bkpt=@{number="2",type="catchpoint",disp="keep",enabled="n", | |
8ac3646f | 26476 | what="load of library matching bar.so",catch-type="unload",times="0"@} |
3fa7bf06 MG |
26477 | (gdb) |
26478 | @end smallexample | |
26479 | ||
40555925 JB |
26480 | @node Ada Exception GDB/MI Catchpoint Commands |
26481 | @subsection Ada Exception @sc{gdb/mi} Catchpoints | |
26482 | ||
26483 | The following @sc{gdb/mi} commands can be used to create catchpoints | |
26484 | that stop the execution when Ada exceptions are being raised. | |
26485 | ||
26486 | @subheading The @code{-catch-assert} Command | |
26487 | @findex -catch-assert | |
26488 | ||
26489 | @subsubheading Synopsis | |
26490 | ||
26491 | @smallexample | |
26492 | -catch-assert [ -c @var{condition}] [ -d ] [ -t ] | |
26493 | @end smallexample | |
26494 | ||
26495 | Add a catchpoint for failed Ada assertions. | |
26496 | ||
26497 | The possible optional parameters for this command are: | |
26498 | ||
26499 | @table @samp | |
26500 | @item -c @var{condition} | |
26501 | Make the catchpoint conditional on @var{condition}. | |
26502 | @item -d | |
26503 | Create a disabled catchpoint. | |
26504 | @item -t | |
26505 | Create a temporary catchpoint. | |
26506 | @end table | |
26507 | ||
26508 | @subsubheading @value{GDBN} Command | |
26509 | ||
26510 | The corresponding @value{GDBN} command is @samp{catch assert}. | |
26511 | ||
26512 | @subsubheading Example | |
26513 | ||
26514 | @smallexample | |
26515 | -catch-assert | |
26516 | ^done,bkptno="5",bkpt=@{number="5",type="breakpoint",disp="keep", | |
26517 | enabled="y",addr="0x0000000000404888",what="failed Ada assertions", | |
26518 | thread-groups=["i1"],times="0", | |
26519 | original-location="__gnat_debug_raise_assert_failure"@} | |
26520 | (gdb) | |
26521 | @end smallexample | |
26522 | ||
26523 | @subheading The @code{-catch-exception} Command | |
26524 | @findex -catch-exception | |
26525 | ||
26526 | @subsubheading Synopsis | |
26527 | ||
26528 | @smallexample | |
26529 | -catch-exception [ -c @var{condition}] [ -d ] [ -e @var{exception-name} ] | |
26530 | [ -t ] [ -u ] | |
26531 | @end smallexample | |
26532 | ||
26533 | Add a catchpoint stopping when Ada exceptions are raised. | |
26534 | By default, the command stops the program when any Ada exception | |
26535 | gets raised. But it is also possible, by using some of the | |
26536 | optional parameters described below, to create more selective | |
26537 | catchpoints. | |
26538 | ||
26539 | The possible optional parameters for this command are: | |
26540 | ||
26541 | @table @samp | |
26542 | @item -c @var{condition} | |
26543 | Make the catchpoint conditional on @var{condition}. | |
26544 | @item -d | |
26545 | Create a disabled catchpoint. | |
26546 | @item -e @var{exception-name} | |
26547 | Only stop when @var{exception-name} is raised. This option cannot | |
26548 | be used combined with @samp{-u}. | |
26549 | @item -t | |
26550 | Create a temporary catchpoint. | |
26551 | @item -u | |
26552 | Stop only when an unhandled exception gets raised. This option | |
26553 | cannot be used combined with @samp{-e}. | |
26554 | @end table | |
26555 | ||
26556 | @subsubheading @value{GDBN} Command | |
26557 | ||
26558 | The corresponding @value{GDBN} commands are @samp{catch exception} | |
26559 | and @samp{catch exception unhandled}. | |
26560 | ||
26561 | @subsubheading Example | |
26562 | ||
26563 | @smallexample | |
26564 | -catch-exception -e Program_Error | |
26565 | ^done,bkptno="4",bkpt=@{number="4",type="breakpoint",disp="keep", | |
26566 | enabled="y",addr="0x0000000000404874", | |
26567 | what="`Program_Error' Ada exception", thread-groups=["i1"], | |
26568 | times="0",original-location="__gnat_debug_raise_exception"@} | |
26569 | (gdb) | |
26570 | @end smallexample | |
3fa7bf06 | 26571 | |
922fbb7b | 26572 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
a2c02241 NR |
26573 | @node GDB/MI Program Context |
26574 | @section @sc{gdb/mi} Program Context | |
922fbb7b | 26575 | |
a2c02241 NR |
26576 | @subheading The @code{-exec-arguments} Command |
26577 | @findex -exec-arguments | |
922fbb7b | 26578 | |
922fbb7b AC |
26579 | |
26580 | @subsubheading Synopsis | |
26581 | ||
26582 | @smallexample | |
a2c02241 | 26583 | -exec-arguments @var{args} |
922fbb7b AC |
26584 | @end smallexample |
26585 | ||
a2c02241 NR |
26586 | Set the inferior program arguments, to be used in the next |
26587 | @samp{-exec-run}. | |
922fbb7b | 26588 | |
a2c02241 | 26589 | @subsubheading @value{GDBN} Command |
922fbb7b | 26590 | |
a2c02241 | 26591 | The corresponding @value{GDBN} command is @samp{set args}. |
922fbb7b | 26592 | |
a2c02241 | 26593 | @subsubheading Example |
922fbb7b | 26594 | |
fbc5282e MK |
26595 | @smallexample |
26596 | (gdb) | |
26597 | -exec-arguments -v word | |
26598 | ^done | |
26599 | (gdb) | |
26600 | @end smallexample | |
922fbb7b | 26601 | |
a2c02241 | 26602 | |
9901a55b | 26603 | @ignore |
a2c02241 NR |
26604 | @subheading The @code{-exec-show-arguments} Command |
26605 | @findex -exec-show-arguments | |
26606 | ||
26607 | @subsubheading Synopsis | |
26608 | ||
26609 | @smallexample | |
26610 | -exec-show-arguments | |
26611 | @end smallexample | |
26612 | ||
26613 | Print the arguments of the program. | |
922fbb7b AC |
26614 | |
26615 | @subsubheading @value{GDBN} Command | |
26616 | ||
a2c02241 | 26617 | The corresponding @value{GDBN} command is @samp{show args}. |
922fbb7b AC |
26618 | |
26619 | @subsubheading Example | |
a2c02241 | 26620 | N.A. |
9901a55b | 26621 | @end ignore |
922fbb7b | 26622 | |
922fbb7b | 26623 | |
a2c02241 NR |
26624 | @subheading The @code{-environment-cd} Command |
26625 | @findex -environment-cd | |
922fbb7b | 26626 | |
a2c02241 | 26627 | @subsubheading Synopsis |
922fbb7b AC |
26628 | |
26629 | @smallexample | |
a2c02241 | 26630 | -environment-cd @var{pathdir} |
922fbb7b AC |
26631 | @end smallexample |
26632 | ||
a2c02241 | 26633 | Set @value{GDBN}'s working directory. |
922fbb7b | 26634 | |
a2c02241 | 26635 | @subsubheading @value{GDBN} Command |
922fbb7b | 26636 | |
a2c02241 NR |
26637 | The corresponding @value{GDBN} command is @samp{cd}. |
26638 | ||
26639 | @subsubheading Example | |
922fbb7b AC |
26640 | |
26641 | @smallexample | |
594fe323 | 26642 | (gdb) |
a2c02241 NR |
26643 | -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb |
26644 | ^done | |
594fe323 | 26645 | (gdb) |
922fbb7b AC |
26646 | @end smallexample |
26647 | ||
26648 | ||
a2c02241 NR |
26649 | @subheading The @code{-environment-directory} Command |
26650 | @findex -environment-directory | |
922fbb7b AC |
26651 | |
26652 | @subsubheading Synopsis | |
26653 | ||
26654 | @smallexample | |
a2c02241 | 26655 | -environment-directory [ -r ] [ @var{pathdir} ]+ |
922fbb7b AC |
26656 | @end smallexample |
26657 | ||
a2c02241 NR |
26658 | Add directories @var{pathdir} to beginning of search path for source files. |
26659 | If the @samp{-r} option is used, the search path is reset to the default | |
26660 | search path. If directories @var{pathdir} are supplied in addition to the | |
26661 | @samp{-r} option, the search path is first reset and then addition | |
26662 | occurs as normal. | |
26663 | Multiple directories may be specified, separated by blanks. Specifying | |
26664 | multiple directories in a single command | |
26665 | results in the directories added to the beginning of the | |
26666 | search path in the same order they were presented in the command. | |
26667 | If blanks are needed as | |
26668 | part of a directory name, double-quotes should be used around | |
26669 | the name. In the command output, the path will show up separated | |
d3e8051b | 26670 | by the system directory-separator character. The directory-separator |
a2c02241 NR |
26671 | character must not be used |
26672 | in any directory name. | |
26673 | If no directories are specified, the current search path is displayed. | |
922fbb7b AC |
26674 | |
26675 | @subsubheading @value{GDBN} Command | |
26676 | ||
a2c02241 | 26677 | The corresponding @value{GDBN} command is @samp{dir}. |
922fbb7b AC |
26678 | |
26679 | @subsubheading Example | |
26680 | ||
922fbb7b | 26681 | @smallexample |
594fe323 | 26682 | (gdb) |
a2c02241 NR |
26683 | -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb |
26684 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
594fe323 | 26685 | (gdb) |
a2c02241 NR |
26686 | -environment-directory "" |
26687 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
594fe323 | 26688 | (gdb) |
a2c02241 NR |
26689 | -environment-directory -r /home/jjohnstn/src/gdb /usr/src |
26690 | ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd" | |
594fe323 | 26691 | (gdb) |
a2c02241 NR |
26692 | -environment-directory -r |
26693 | ^done,source-path="$cdir:$cwd" | |
594fe323 | 26694 | (gdb) |
922fbb7b AC |
26695 | @end smallexample |
26696 | ||
26697 | ||
a2c02241 NR |
26698 | @subheading The @code{-environment-path} Command |
26699 | @findex -environment-path | |
922fbb7b AC |
26700 | |
26701 | @subsubheading Synopsis | |
26702 | ||
26703 | @smallexample | |
a2c02241 | 26704 | -environment-path [ -r ] [ @var{pathdir} ]+ |
922fbb7b AC |
26705 | @end smallexample |
26706 | ||
a2c02241 NR |
26707 | Add directories @var{pathdir} to beginning of search path for object files. |
26708 | If the @samp{-r} option is used, the search path is reset to the original | |
26709 | search path that existed at gdb start-up. If directories @var{pathdir} are | |
26710 | supplied in addition to the | |
26711 | @samp{-r} option, the search path is first reset and then addition | |
26712 | occurs as normal. | |
26713 | Multiple directories may be specified, separated by blanks. Specifying | |
26714 | multiple directories in a single command | |
26715 | results in the directories added to the beginning of the | |
26716 | search path in the same order they were presented in the command. | |
26717 | If blanks are needed as | |
26718 | part of a directory name, double-quotes should be used around | |
26719 | the name. In the command output, the path will show up separated | |
d3e8051b | 26720 | by the system directory-separator character. The directory-separator |
a2c02241 NR |
26721 | character must not be used |
26722 | in any directory name. | |
26723 | If no directories are specified, the current path is displayed. | |
26724 | ||
922fbb7b AC |
26725 | |
26726 | @subsubheading @value{GDBN} Command | |
26727 | ||
a2c02241 | 26728 | The corresponding @value{GDBN} command is @samp{path}. |
922fbb7b AC |
26729 | |
26730 | @subsubheading Example | |
26731 | ||
922fbb7b | 26732 | @smallexample |
594fe323 | 26733 | (gdb) |
a2c02241 NR |
26734 | -environment-path |
26735 | ^done,path="/usr/bin" | |
594fe323 | 26736 | (gdb) |
a2c02241 NR |
26737 | -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin |
26738 | ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin" | |
594fe323 | 26739 | (gdb) |
a2c02241 NR |
26740 | -environment-path -r /usr/local/bin |
26741 | ^done,path="/usr/local/bin:/usr/bin" | |
594fe323 | 26742 | (gdb) |
922fbb7b AC |
26743 | @end smallexample |
26744 | ||
26745 | ||
a2c02241 NR |
26746 | @subheading The @code{-environment-pwd} Command |
26747 | @findex -environment-pwd | |
922fbb7b AC |
26748 | |
26749 | @subsubheading Synopsis | |
26750 | ||
26751 | @smallexample | |
a2c02241 | 26752 | -environment-pwd |
922fbb7b AC |
26753 | @end smallexample |
26754 | ||
a2c02241 | 26755 | Show the current working directory. |
922fbb7b | 26756 | |
79a6e687 | 26757 | @subsubheading @value{GDBN} Command |
922fbb7b | 26758 | |
a2c02241 | 26759 | The corresponding @value{GDBN} command is @samp{pwd}. |
922fbb7b AC |
26760 | |
26761 | @subsubheading Example | |
26762 | ||
922fbb7b | 26763 | @smallexample |
594fe323 | 26764 | (gdb) |
a2c02241 NR |
26765 | -environment-pwd |
26766 | ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb" | |
594fe323 | 26767 | (gdb) |
922fbb7b AC |
26768 | @end smallexample |
26769 | ||
a2c02241 NR |
26770 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
26771 | @node GDB/MI Thread Commands | |
26772 | @section @sc{gdb/mi} Thread Commands | |
26773 | ||
26774 | ||
26775 | @subheading The @code{-thread-info} Command | |
26776 | @findex -thread-info | |
922fbb7b AC |
26777 | |
26778 | @subsubheading Synopsis | |
26779 | ||
26780 | @smallexample | |
8e8901c5 | 26781 | -thread-info [ @var{thread-id} ] |
922fbb7b AC |
26782 | @end smallexample |
26783 | ||
8e8901c5 VP |
26784 | Reports information about either a specific thread, if |
26785 | the @var{thread-id} parameter is present, or about all | |
26786 | threads. When printing information about all threads, | |
26787 | also reports the current thread. | |
26788 | ||
79a6e687 | 26789 | @subsubheading @value{GDBN} Command |
922fbb7b | 26790 | |
8e8901c5 VP |
26791 | The @samp{info thread} command prints the same information |
26792 | about all threads. | |
922fbb7b | 26793 | |
4694da01 | 26794 | @subsubheading Result |
922fbb7b | 26795 | |
4694da01 TT |
26796 | The result is a list of threads. The following attributes are |
26797 | defined for a given thread: | |
26798 | ||
26799 | @table @samp | |
26800 | @item current | |
26801 | This field exists only for the current thread. It has the value @samp{*}. | |
26802 | ||
26803 | @item id | |
26804 | The identifier that @value{GDBN} uses to refer to the thread. | |
26805 | ||
26806 | @item target-id | |
26807 | The identifier that the target uses to refer to the thread. | |
26808 | ||
26809 | @item details | |
26810 | Extra information about the thread, in a target-specific format. This | |
26811 | field is optional. | |
26812 | ||
26813 | @item name | |
26814 | The name of the thread. If the user specified a name using the | |
26815 | @code{thread name} command, then this name is given. Otherwise, if | |
26816 | @value{GDBN} can extract the thread name from the target, then that | |
26817 | name is given. If @value{GDBN} cannot find the thread name, then this | |
26818 | field is omitted. | |
26819 | ||
26820 | @item frame | |
26821 | The stack frame currently executing in the thread. | |
922fbb7b | 26822 | |
4694da01 TT |
26823 | @item state |
26824 | The thread's state. The @samp{state} field may have the following | |
26825 | values: | |
c3b108f7 VP |
26826 | |
26827 | @table @code | |
26828 | @item stopped | |
26829 | The thread is stopped. Frame information is available for stopped | |
26830 | threads. | |
26831 | ||
26832 | @item running | |
26833 | The thread is running. There's no frame information for running | |
26834 | threads. | |
26835 | ||
26836 | @end table | |
26837 | ||
4694da01 TT |
26838 | @item core |
26839 | If @value{GDBN} can find the CPU core on which this thread is running, | |
26840 | then this field is the core identifier. This field is optional. | |
26841 | ||
26842 | @end table | |
26843 | ||
26844 | @subsubheading Example | |
26845 | ||
26846 | @smallexample | |
26847 | -thread-info | |
26848 | ^done,threads=[ | |
26849 | @{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", | |
26850 | frame=@{level="0",addr="0xffffe410",func="__kernel_vsyscall", | |
26851 | args=[]@},state="running"@}, | |
26852 | @{id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", | |
26853 | frame=@{level="0",addr="0x0804891f",func="foo", | |
26854 | args=[@{name="i",value="10"@}], | |
26855 | file="/tmp/a.c",fullname="/tmp/a.c",line="158"@}, | |
26856 | state="running"@}], | |
26857 | current-thread-id="1" | |
26858 | (gdb) | |
26859 | @end smallexample | |
26860 | ||
a2c02241 NR |
26861 | @subheading The @code{-thread-list-ids} Command |
26862 | @findex -thread-list-ids | |
922fbb7b | 26863 | |
a2c02241 | 26864 | @subsubheading Synopsis |
922fbb7b | 26865 | |
a2c02241 NR |
26866 | @smallexample |
26867 | -thread-list-ids | |
26868 | @end smallexample | |
922fbb7b | 26869 | |
a2c02241 NR |
26870 | Produces a list of the currently known @value{GDBN} thread ids. At the |
26871 | end of the list it also prints the total number of such threads. | |
922fbb7b | 26872 | |
c3b108f7 VP |
26873 | This command is retained for historical reasons, the |
26874 | @code{-thread-info} command should be used instead. | |
26875 | ||
922fbb7b AC |
26876 | @subsubheading @value{GDBN} Command |
26877 | ||
a2c02241 | 26878 | Part of @samp{info threads} supplies the same information. |
922fbb7b AC |
26879 | |
26880 | @subsubheading Example | |
26881 | ||
922fbb7b | 26882 | @smallexample |
594fe323 | 26883 | (gdb) |
a2c02241 NR |
26884 | -thread-list-ids |
26885 | ^done,thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
592375cd | 26886 | current-thread-id="1",number-of-threads="3" |
594fe323 | 26887 | (gdb) |
922fbb7b AC |
26888 | @end smallexample |
26889 | ||
a2c02241 NR |
26890 | |
26891 | @subheading The @code{-thread-select} Command | |
26892 | @findex -thread-select | |
922fbb7b AC |
26893 | |
26894 | @subsubheading Synopsis | |
26895 | ||
26896 | @smallexample | |
a2c02241 | 26897 | -thread-select @var{threadnum} |
922fbb7b AC |
26898 | @end smallexample |
26899 | ||
a2c02241 NR |
26900 | Make @var{threadnum} the current thread. It prints the number of the new |
26901 | current thread, and the topmost frame for that thread. | |
922fbb7b | 26902 | |
c3b108f7 VP |
26903 | This command is deprecated in favor of explicitly using the |
26904 | @samp{--thread} option to each command. | |
26905 | ||
922fbb7b AC |
26906 | @subsubheading @value{GDBN} Command |
26907 | ||
a2c02241 | 26908 | The corresponding @value{GDBN} command is @samp{thread}. |
922fbb7b AC |
26909 | |
26910 | @subsubheading Example | |
922fbb7b AC |
26911 | |
26912 | @smallexample | |
594fe323 | 26913 | (gdb) |
a2c02241 NR |
26914 | -exec-next |
26915 | ^running | |
594fe323 | 26916 | (gdb) |
a2c02241 NR |
26917 | *stopped,reason="end-stepping-range",thread-id="2",line="187", |
26918 | file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c" | |
594fe323 | 26919 | (gdb) |
a2c02241 NR |
26920 | -thread-list-ids |
26921 | ^done, | |
26922 | thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
26923 | number-of-threads="3" | |
594fe323 | 26924 | (gdb) |
a2c02241 NR |
26925 | -thread-select 3 |
26926 | ^done,new-thread-id="3", | |
26927 | frame=@{level="0",func="vprintf", | |
26928 | args=[@{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""@}, | |
26929 | @{name="arg",value="0x2"@}],file="vprintf.c",line="31"@} | |
594fe323 | 26930 | (gdb) |
922fbb7b AC |
26931 | @end smallexample |
26932 | ||
5d77fe44 JB |
26933 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
26934 | @node GDB/MI Ada Tasking Commands | |
26935 | @section @sc{gdb/mi} Ada Tasking Commands | |
26936 | ||
26937 | @subheading The @code{-ada-task-info} Command | |
26938 | @findex -ada-task-info | |
26939 | ||
26940 | @subsubheading Synopsis | |
26941 | ||
26942 | @smallexample | |
26943 | -ada-task-info [ @var{task-id} ] | |
26944 | @end smallexample | |
26945 | ||
26946 | Reports information about either a specific Ada task, if the | |
26947 | @var{task-id} parameter is present, or about all Ada tasks. | |
26948 | ||
26949 | @subsubheading @value{GDBN} Command | |
26950 | ||
26951 | The @samp{info tasks} command prints the same information | |
26952 | about all Ada tasks (@pxref{Ada Tasks}). | |
26953 | ||
26954 | @subsubheading Result | |
26955 | ||
26956 | The result is a table of Ada tasks. The following columns are | |
26957 | defined for each Ada task: | |
26958 | ||
26959 | @table @samp | |
26960 | @item current | |
26961 | This field exists only for the current thread. It has the value @samp{*}. | |
26962 | ||
26963 | @item id | |
26964 | The identifier that @value{GDBN} uses to refer to the Ada task. | |
26965 | ||
26966 | @item task-id | |
26967 | The identifier that the target uses to refer to the Ada task. | |
26968 | ||
26969 | @item thread-id | |
26970 | The identifier of the thread corresponding to the Ada task. | |
26971 | ||
26972 | This field should always exist, as Ada tasks are always implemented | |
26973 | on top of a thread. But if @value{GDBN} cannot find this corresponding | |
26974 | thread for any reason, the field is omitted. | |
26975 | ||
26976 | @item parent-id | |
26977 | This field exists only when the task was created by another task. | |
26978 | In this case, it provides the ID of the parent task. | |
26979 | ||
26980 | @item priority | |
26981 | The base priority of the task. | |
26982 | ||
26983 | @item state | |
26984 | The current state of the task. For a detailed description of the | |
26985 | possible states, see @ref{Ada Tasks}. | |
26986 | ||
26987 | @item name | |
26988 | The name of the task. | |
26989 | ||
26990 | @end table | |
26991 | ||
26992 | @subsubheading Example | |
26993 | ||
26994 | @smallexample | |
26995 | -ada-task-info | |
26996 | ^done,tasks=@{nr_rows="3",nr_cols="8", | |
26997 | hdr=[@{width="1",alignment="-1",col_name="current",colhdr=""@}, | |
26998 | @{width="3",alignment="1",col_name="id",colhdr="ID"@}, | |
26999 | @{width="9",alignment="1",col_name="task-id",colhdr="TID"@}, | |
27000 | @{width="4",alignment="1",col_name="thread-id",colhdr=""@}, | |
27001 | @{width="4",alignment="1",col_name="parent-id",colhdr="P-ID"@}, | |
27002 | @{width="3",alignment="1",col_name="priority",colhdr="Pri"@}, | |
27003 | @{width="22",alignment="-1",col_name="state",colhdr="State"@}, | |
27004 | @{width="1",alignment="2",col_name="name",colhdr="Name"@}], | |
27005 | body=[@{current="*",id="1",task-id=" 644010",thread-id="1",priority="48", | |
27006 | state="Child Termination Wait",name="main_task"@}]@} | |
27007 | (gdb) | |
27008 | @end smallexample | |
27009 | ||
a2c02241 NR |
27010 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
27011 | @node GDB/MI Program Execution | |
27012 | @section @sc{gdb/mi} Program Execution | |
922fbb7b | 27013 | |
ef21caaf | 27014 | These are the asynchronous commands which generate the out-of-band |
3f94c067 | 27015 | record @samp{*stopped}. Currently @value{GDBN} only really executes |
ef21caaf NR |
27016 | asynchronously with remote targets and this interaction is mimicked in |
27017 | other cases. | |
922fbb7b | 27018 | |
922fbb7b AC |
27019 | @subheading The @code{-exec-continue} Command |
27020 | @findex -exec-continue | |
27021 | ||
27022 | @subsubheading Synopsis | |
27023 | ||
27024 | @smallexample | |
540aa8e7 | 27025 | -exec-continue [--reverse] [--all|--thread-group N] |
922fbb7b AC |
27026 | @end smallexample |
27027 | ||
540aa8e7 MS |
27028 | Resumes the execution of the inferior program, which will continue |
27029 | to execute until it reaches a debugger stop event. If the | |
27030 | @samp{--reverse} option is specified, execution resumes in reverse until | |
27031 | it reaches a stop event. Stop events may include | |
27032 | @itemize @bullet | |
27033 | @item | |
27034 | breakpoints or watchpoints | |
27035 | @item | |
27036 | signals or exceptions | |
27037 | @item | |
27038 | the end of the process (or its beginning under @samp{--reverse}) | |
27039 | @item | |
27040 | the end or beginning of a replay log if one is being used. | |
27041 | @end itemize | |
27042 | In all-stop mode (@pxref{All-Stop | |
27043 | Mode}), may resume only one thread, or all threads, depending on the | |
27044 | value of the @samp{scheduler-locking} variable. If @samp{--all} is | |
a79b8f6e | 27045 | specified, all threads (in all inferiors) will be resumed. The @samp{--all} option is |
540aa8e7 MS |
27046 | ignored in all-stop mode. If the @samp{--thread-group} options is |
27047 | specified, then all threads in that thread group are resumed. | |
922fbb7b AC |
27048 | |
27049 | @subsubheading @value{GDBN} Command | |
27050 | ||
27051 | The corresponding @value{GDBN} corresponding is @samp{continue}. | |
27052 | ||
27053 | @subsubheading Example | |
27054 | ||
27055 | @smallexample | |
27056 | -exec-continue | |
27057 | ^running | |
594fe323 | 27058 | (gdb) |
922fbb7b | 27059 | @@Hello world |
a47ec5fe AR |
27060 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",frame=@{ |
27061 | func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c", | |
27062 | line="13"@} | |
594fe323 | 27063 | (gdb) |
922fbb7b AC |
27064 | @end smallexample |
27065 | ||
27066 | ||
27067 | @subheading The @code{-exec-finish} Command | |
27068 | @findex -exec-finish | |
27069 | ||
27070 | @subsubheading Synopsis | |
27071 | ||
27072 | @smallexample | |
540aa8e7 | 27073 | -exec-finish [--reverse] |
922fbb7b AC |
27074 | @end smallexample |
27075 | ||
ef21caaf NR |
27076 | Resumes the execution of the inferior program until the current |
27077 | function is exited. Displays the results returned by the function. | |
540aa8e7 MS |
27078 | If the @samp{--reverse} option is specified, resumes the reverse |
27079 | execution of the inferior program until the point where current | |
27080 | function was called. | |
922fbb7b AC |
27081 | |
27082 | @subsubheading @value{GDBN} Command | |
27083 | ||
27084 | The corresponding @value{GDBN} command is @samp{finish}. | |
27085 | ||
27086 | @subsubheading Example | |
27087 | ||
27088 | Function returning @code{void}. | |
27089 | ||
27090 | @smallexample | |
27091 | -exec-finish | |
27092 | ^running | |
594fe323 | 27093 | (gdb) |
922fbb7b AC |
27094 | @@hello from foo |
27095 | *stopped,reason="function-finished",frame=@{func="main",args=[], | |
948d5102 | 27096 | file="hello.c",fullname="/home/foo/bar/hello.c",line="7"@} |
594fe323 | 27097 | (gdb) |
922fbb7b AC |
27098 | @end smallexample |
27099 | ||
27100 | Function returning other than @code{void}. The name of the internal | |
27101 | @value{GDBN} variable storing the result is printed, together with the | |
27102 | value itself. | |
27103 | ||
27104 | @smallexample | |
27105 | -exec-finish | |
27106 | ^running | |
594fe323 | 27107 | (gdb) |
922fbb7b AC |
27108 | *stopped,reason="function-finished",frame=@{addr="0x000107b0",func="foo", |
27109 | args=[@{name="a",value="1"],@{name="b",value="9"@}@}, | |
948d5102 | 27110 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, |
922fbb7b | 27111 | gdb-result-var="$1",return-value="0" |
594fe323 | 27112 | (gdb) |
922fbb7b AC |
27113 | @end smallexample |
27114 | ||
27115 | ||
27116 | @subheading The @code{-exec-interrupt} Command | |
27117 | @findex -exec-interrupt | |
27118 | ||
27119 | @subsubheading Synopsis | |
27120 | ||
27121 | @smallexample | |
c3b108f7 | 27122 | -exec-interrupt [--all|--thread-group N] |
922fbb7b AC |
27123 | @end smallexample |
27124 | ||
ef21caaf NR |
27125 | Interrupts the background execution of the target. Note how the token |
27126 | associated with the stop message is the one for the execution command | |
27127 | that has been interrupted. The token for the interrupt itself only | |
27128 | appears in the @samp{^done} output. If the user is trying to | |
922fbb7b AC |
27129 | interrupt a non-running program, an error message will be printed. |
27130 | ||
c3b108f7 VP |
27131 | Note that when asynchronous execution is enabled, this command is |
27132 | asynchronous just like other execution commands. That is, first the | |
27133 | @samp{^done} response will be printed, and the target stop will be | |
27134 | reported after that using the @samp{*stopped} notification. | |
27135 | ||
27136 | In non-stop mode, only the context thread is interrupted by default. | |
a79b8f6e VP |
27137 | All threads (in all inferiors) will be interrupted if the |
27138 | @samp{--all} option is specified. If the @samp{--thread-group} | |
27139 | option is specified, all threads in that group will be interrupted. | |
c3b108f7 | 27140 | |
922fbb7b AC |
27141 | @subsubheading @value{GDBN} Command |
27142 | ||
27143 | The corresponding @value{GDBN} command is @samp{interrupt}. | |
27144 | ||
27145 | @subsubheading Example | |
27146 | ||
27147 | @smallexample | |
594fe323 | 27148 | (gdb) |
922fbb7b AC |
27149 | 111-exec-continue |
27150 | 111^running | |
27151 | ||
594fe323 | 27152 | (gdb) |
922fbb7b AC |
27153 | 222-exec-interrupt |
27154 | 222^done | |
594fe323 | 27155 | (gdb) |
922fbb7b | 27156 | 111*stopped,signal-name="SIGINT",signal-meaning="Interrupt", |
76ff342d | 27157 | frame=@{addr="0x00010140",func="foo",args=[],file="try.c", |
948d5102 | 27158 | fullname="/home/foo/bar/try.c",line="13"@} |
594fe323 | 27159 | (gdb) |
922fbb7b | 27160 | |
594fe323 | 27161 | (gdb) |
922fbb7b AC |
27162 | -exec-interrupt |
27163 | ^error,msg="mi_cmd_exec_interrupt: Inferior not executing." | |
594fe323 | 27164 | (gdb) |
922fbb7b AC |
27165 | @end smallexample |
27166 | ||
83eba9b7 VP |
27167 | @subheading The @code{-exec-jump} Command |
27168 | @findex -exec-jump | |
27169 | ||
27170 | @subsubheading Synopsis | |
27171 | ||
27172 | @smallexample | |
27173 | -exec-jump @var{location} | |
27174 | @end smallexample | |
27175 | ||
27176 | Resumes execution of the inferior program at the location specified by | |
27177 | parameter. @xref{Specify Location}, for a description of the | |
27178 | different forms of @var{location}. | |
27179 | ||
27180 | @subsubheading @value{GDBN} Command | |
27181 | ||
27182 | The corresponding @value{GDBN} command is @samp{jump}. | |
27183 | ||
27184 | @subsubheading Example | |
27185 | ||
27186 | @smallexample | |
27187 | -exec-jump foo.c:10 | |
27188 | *running,thread-id="all" | |
27189 | ^running | |
27190 | @end smallexample | |
27191 | ||
922fbb7b AC |
27192 | |
27193 | @subheading The @code{-exec-next} Command | |
27194 | @findex -exec-next | |
27195 | ||
27196 | @subsubheading Synopsis | |
27197 | ||
27198 | @smallexample | |
540aa8e7 | 27199 | -exec-next [--reverse] |
922fbb7b AC |
27200 | @end smallexample |
27201 | ||
ef21caaf NR |
27202 | Resumes execution of the inferior program, stopping when the beginning |
27203 | of the next source line is reached. | |
922fbb7b | 27204 | |
540aa8e7 MS |
27205 | If the @samp{--reverse} option is specified, resumes reverse execution |
27206 | of the inferior program, stopping at the beginning of the previous | |
27207 | source line. If you issue this command on the first line of a | |
27208 | function, it will take you back to the caller of that function, to the | |
27209 | source line where the function was called. | |
27210 | ||
27211 | ||
922fbb7b AC |
27212 | @subsubheading @value{GDBN} Command |
27213 | ||
27214 | The corresponding @value{GDBN} command is @samp{next}. | |
27215 | ||
27216 | @subsubheading Example | |
27217 | ||
27218 | @smallexample | |
27219 | -exec-next | |
27220 | ^running | |
594fe323 | 27221 | (gdb) |
922fbb7b | 27222 | *stopped,reason="end-stepping-range",line="8",file="hello.c" |
594fe323 | 27223 | (gdb) |
922fbb7b AC |
27224 | @end smallexample |
27225 | ||
27226 | ||
27227 | @subheading The @code{-exec-next-instruction} Command | |
27228 | @findex -exec-next-instruction | |
27229 | ||
27230 | @subsubheading Synopsis | |
27231 | ||
27232 | @smallexample | |
540aa8e7 | 27233 | -exec-next-instruction [--reverse] |
922fbb7b AC |
27234 | @end smallexample |
27235 | ||
ef21caaf NR |
27236 | Executes one machine instruction. If the instruction is a function |
27237 | call, continues until the function returns. If the program stops at an | |
27238 | instruction in the middle of a source line, the address will be | |
27239 | printed as well. | |
922fbb7b | 27240 | |
540aa8e7 MS |
27241 | If the @samp{--reverse} option is specified, resumes reverse execution |
27242 | of the inferior program, stopping at the previous instruction. If the | |
27243 | previously executed instruction was a return from another function, | |
27244 | it will continue to execute in reverse until the call to that function | |
27245 | (from the current stack frame) is reached. | |
27246 | ||
922fbb7b AC |
27247 | @subsubheading @value{GDBN} Command |
27248 | ||
27249 | The corresponding @value{GDBN} command is @samp{nexti}. | |
27250 | ||
27251 | @subsubheading Example | |
27252 | ||
27253 | @smallexample | |
594fe323 | 27254 | (gdb) |
922fbb7b AC |
27255 | -exec-next-instruction |
27256 | ^running | |
27257 | ||
594fe323 | 27258 | (gdb) |
922fbb7b AC |
27259 | *stopped,reason="end-stepping-range", |
27260 | addr="0x000100d4",line="5",file="hello.c" | |
594fe323 | 27261 | (gdb) |
922fbb7b AC |
27262 | @end smallexample |
27263 | ||
27264 | ||
27265 | @subheading The @code{-exec-return} Command | |
27266 | @findex -exec-return | |
27267 | ||
27268 | @subsubheading Synopsis | |
27269 | ||
27270 | @smallexample | |
27271 | -exec-return | |
27272 | @end smallexample | |
27273 | ||
27274 | Makes current function return immediately. Doesn't execute the inferior. | |
27275 | Displays the new current frame. | |
27276 | ||
27277 | @subsubheading @value{GDBN} Command | |
27278 | ||
27279 | The corresponding @value{GDBN} command is @samp{return}. | |
27280 | ||
27281 | @subsubheading Example | |
27282 | ||
27283 | @smallexample | |
594fe323 | 27284 | (gdb) |
922fbb7b AC |
27285 | 200-break-insert callee4 |
27286 | 200^done,bkpt=@{number="1",addr="0x00010734", | |
27287 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
594fe323 | 27288 | (gdb) |
922fbb7b AC |
27289 | 000-exec-run |
27290 | 000^running | |
594fe323 | 27291 | (gdb) |
a47ec5fe | 27292 | 000*stopped,reason="breakpoint-hit",disp="keep",bkptno="1", |
922fbb7b | 27293 | frame=@{func="callee4",args=[], |
76ff342d DJ |
27294 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
27295 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
594fe323 | 27296 | (gdb) |
922fbb7b AC |
27297 | 205-break-delete |
27298 | 205^done | |
594fe323 | 27299 | (gdb) |
922fbb7b AC |
27300 | 111-exec-return |
27301 | 111^done,frame=@{level="0",func="callee3", | |
27302 | args=[@{name="strarg", | |
27303 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
27304 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
27305 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 27306 | (gdb) |
922fbb7b AC |
27307 | @end smallexample |
27308 | ||
27309 | ||
27310 | @subheading The @code{-exec-run} Command | |
27311 | @findex -exec-run | |
27312 | ||
27313 | @subsubheading Synopsis | |
27314 | ||
27315 | @smallexample | |
5713b9b5 | 27316 | -exec-run [ --all | --thread-group N ] [ --start ] |
922fbb7b AC |
27317 | @end smallexample |
27318 | ||
ef21caaf NR |
27319 | Starts execution of the inferior from the beginning. The inferior |
27320 | executes until either a breakpoint is encountered or the program | |
27321 | exits. In the latter case the output will include an exit code, if | |
27322 | the program has exited exceptionally. | |
922fbb7b | 27323 | |
5713b9b5 JB |
27324 | When neither the @samp{--all} nor the @samp{--thread-group} option |
27325 | is specified, the current inferior is started. If the | |
a79b8f6e VP |
27326 | @samp{--thread-group} option is specified, it should refer to a thread |
27327 | group of type @samp{process}, and that thread group will be started. | |
27328 | If the @samp{--all} option is specified, then all inferiors will be started. | |
27329 | ||
5713b9b5 JB |
27330 | Using the @samp{--start} option instructs the debugger to stop |
27331 | the execution at the start of the inferior's main subprogram, | |
27332 | following the same behavior as the @code{start} command | |
27333 | (@pxref{Starting}). | |
27334 | ||
922fbb7b AC |
27335 | @subsubheading @value{GDBN} Command |
27336 | ||
27337 | The corresponding @value{GDBN} command is @samp{run}. | |
27338 | ||
ef21caaf | 27339 | @subsubheading Examples |
922fbb7b AC |
27340 | |
27341 | @smallexample | |
594fe323 | 27342 | (gdb) |
922fbb7b AC |
27343 | -break-insert main |
27344 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@} | |
594fe323 | 27345 | (gdb) |
922fbb7b AC |
27346 | -exec-run |
27347 | ^running | |
594fe323 | 27348 | (gdb) |
a47ec5fe | 27349 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1", |
76ff342d | 27350 | frame=@{func="main",args=[],file="recursive2.c", |
948d5102 | 27351 | fullname="/home/foo/bar/recursive2.c",line="4"@} |
594fe323 | 27352 | (gdb) |
922fbb7b AC |
27353 | @end smallexample |
27354 | ||
ef21caaf NR |
27355 | @noindent |
27356 | Program exited normally: | |
27357 | ||
27358 | @smallexample | |
594fe323 | 27359 | (gdb) |
ef21caaf NR |
27360 | -exec-run |
27361 | ^running | |
594fe323 | 27362 | (gdb) |
ef21caaf NR |
27363 | x = 55 |
27364 | *stopped,reason="exited-normally" | |
594fe323 | 27365 | (gdb) |
ef21caaf NR |
27366 | @end smallexample |
27367 | ||
27368 | @noindent | |
27369 | Program exited exceptionally: | |
27370 | ||
27371 | @smallexample | |
594fe323 | 27372 | (gdb) |
ef21caaf NR |
27373 | -exec-run |
27374 | ^running | |
594fe323 | 27375 | (gdb) |
ef21caaf NR |
27376 | x = 55 |
27377 | *stopped,reason="exited",exit-code="01" | |
594fe323 | 27378 | (gdb) |
ef21caaf NR |
27379 | @end smallexample |
27380 | ||
27381 | Another way the program can terminate is if it receives a signal such as | |
27382 | @code{SIGINT}. In this case, @sc{gdb/mi} displays this: | |
27383 | ||
27384 | @smallexample | |
594fe323 | 27385 | (gdb) |
ef21caaf NR |
27386 | *stopped,reason="exited-signalled",signal-name="SIGINT", |
27387 | signal-meaning="Interrupt" | |
27388 | @end smallexample | |
27389 | ||
922fbb7b | 27390 | |
a2c02241 NR |
27391 | @c @subheading -exec-signal |
27392 | ||
27393 | ||
27394 | @subheading The @code{-exec-step} Command | |
27395 | @findex -exec-step | |
922fbb7b AC |
27396 | |
27397 | @subsubheading Synopsis | |
27398 | ||
27399 | @smallexample | |
540aa8e7 | 27400 | -exec-step [--reverse] |
922fbb7b AC |
27401 | @end smallexample |
27402 | ||
a2c02241 NR |
27403 | Resumes execution of the inferior program, stopping when the beginning |
27404 | of the next source line is reached, if the next source line is not a | |
27405 | function call. If it is, stop at the first instruction of the called | |
540aa8e7 MS |
27406 | function. If the @samp{--reverse} option is specified, resumes reverse |
27407 | execution of the inferior program, stopping at the beginning of the | |
27408 | previously executed source line. | |
922fbb7b AC |
27409 | |
27410 | @subsubheading @value{GDBN} Command | |
27411 | ||
a2c02241 | 27412 | The corresponding @value{GDBN} command is @samp{step}. |
922fbb7b AC |
27413 | |
27414 | @subsubheading Example | |
27415 | ||
27416 | Stepping into a function: | |
27417 | ||
27418 | @smallexample | |
27419 | -exec-step | |
27420 | ^running | |
594fe323 | 27421 | (gdb) |
922fbb7b AC |
27422 | *stopped,reason="end-stepping-range", |
27423 | frame=@{func="foo",args=[@{name="a",value="10"@}, | |
76ff342d | 27424 | @{name="b",value="0"@}],file="recursive2.c", |
948d5102 | 27425 | fullname="/home/foo/bar/recursive2.c",line="11"@} |
594fe323 | 27426 | (gdb) |
922fbb7b AC |
27427 | @end smallexample |
27428 | ||
27429 | Regular stepping: | |
27430 | ||
27431 | @smallexample | |
27432 | -exec-step | |
27433 | ^running | |
594fe323 | 27434 | (gdb) |
922fbb7b | 27435 | *stopped,reason="end-stepping-range",line="14",file="recursive2.c" |
594fe323 | 27436 | (gdb) |
922fbb7b AC |
27437 | @end smallexample |
27438 | ||
27439 | ||
27440 | @subheading The @code{-exec-step-instruction} Command | |
27441 | @findex -exec-step-instruction | |
27442 | ||
27443 | @subsubheading Synopsis | |
27444 | ||
27445 | @smallexample | |
540aa8e7 | 27446 | -exec-step-instruction [--reverse] |
922fbb7b AC |
27447 | @end smallexample |
27448 | ||
540aa8e7 MS |
27449 | Resumes the inferior which executes one machine instruction. If the |
27450 | @samp{--reverse} option is specified, resumes reverse execution of the | |
27451 | inferior program, stopping at the previously executed instruction. | |
27452 | The output, once @value{GDBN} has stopped, will vary depending on | |
27453 | whether we have stopped in the middle of a source line or not. In the | |
27454 | former case, the address at which the program stopped will be printed | |
27455 | as well. | |
922fbb7b AC |
27456 | |
27457 | @subsubheading @value{GDBN} Command | |
27458 | ||
27459 | The corresponding @value{GDBN} command is @samp{stepi}. | |
27460 | ||
27461 | @subsubheading Example | |
27462 | ||
27463 | @smallexample | |
594fe323 | 27464 | (gdb) |
922fbb7b AC |
27465 | -exec-step-instruction |
27466 | ^running | |
27467 | ||
594fe323 | 27468 | (gdb) |
922fbb7b | 27469 | *stopped,reason="end-stepping-range", |
76ff342d | 27470 | frame=@{func="foo",args=[],file="try.c", |
948d5102 | 27471 | fullname="/home/foo/bar/try.c",line="10"@} |
594fe323 | 27472 | (gdb) |
922fbb7b AC |
27473 | -exec-step-instruction |
27474 | ^running | |
27475 | ||
594fe323 | 27476 | (gdb) |
922fbb7b | 27477 | *stopped,reason="end-stepping-range", |
76ff342d | 27478 | frame=@{addr="0x000100f4",func="foo",args=[],file="try.c", |
948d5102 | 27479 | fullname="/home/foo/bar/try.c",line="10"@} |
594fe323 | 27480 | (gdb) |
922fbb7b AC |
27481 | @end smallexample |
27482 | ||
27483 | ||
27484 | @subheading The @code{-exec-until} Command | |
27485 | @findex -exec-until | |
27486 | ||
27487 | @subsubheading Synopsis | |
27488 | ||
27489 | @smallexample | |
27490 | -exec-until [ @var{location} ] | |
27491 | @end smallexample | |
27492 | ||
ef21caaf NR |
27493 | Executes the inferior until the @var{location} specified in the |
27494 | argument is reached. If there is no argument, the inferior executes | |
27495 | until a source line greater than the current one is reached. The | |
27496 | reason for stopping in this case will be @samp{location-reached}. | |
922fbb7b AC |
27497 | |
27498 | @subsubheading @value{GDBN} Command | |
27499 | ||
27500 | The corresponding @value{GDBN} command is @samp{until}. | |
27501 | ||
27502 | @subsubheading Example | |
27503 | ||
27504 | @smallexample | |
594fe323 | 27505 | (gdb) |
922fbb7b AC |
27506 | -exec-until recursive2.c:6 |
27507 | ^running | |
594fe323 | 27508 | (gdb) |
922fbb7b AC |
27509 | x = 55 |
27510 | *stopped,reason="location-reached",frame=@{func="main",args=[], | |
948d5102 | 27511 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6"@} |
594fe323 | 27512 | (gdb) |
922fbb7b AC |
27513 | @end smallexample |
27514 | ||
27515 | @ignore | |
27516 | @subheading -file-clear | |
27517 | Is this going away???? | |
27518 | @end ignore | |
27519 | ||
351ff01a | 27520 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
a2c02241 NR |
27521 | @node GDB/MI Stack Manipulation |
27522 | @section @sc{gdb/mi} Stack Manipulation Commands | |
351ff01a | 27523 | |
1e611234 PM |
27524 | @subheading The @code{-enable-frame-filters} Command |
27525 | @findex -enable-frame-filters | |
27526 | ||
27527 | @smallexample | |
27528 | -enable-frame-filters | |
27529 | @end smallexample | |
27530 | ||
27531 | @value{GDBN} allows Python-based frame filters to affect the output of | |
27532 | the MI commands relating to stack traces. As there is no way to | |
27533 | implement this in a fully backward-compatible way, a front end must | |
27534 | request that this functionality be enabled. | |
27535 | ||
27536 | Once enabled, this feature cannot be disabled. | |
27537 | ||
27538 | Note that if Python support has not been compiled into @value{GDBN}, | |
27539 | this command will still succeed (and do nothing). | |
922fbb7b | 27540 | |
a2c02241 NR |
27541 | @subheading The @code{-stack-info-frame} Command |
27542 | @findex -stack-info-frame | |
922fbb7b AC |
27543 | |
27544 | @subsubheading Synopsis | |
27545 | ||
27546 | @smallexample | |
a2c02241 | 27547 | -stack-info-frame |
922fbb7b AC |
27548 | @end smallexample |
27549 | ||
a2c02241 | 27550 | Get info on the selected frame. |
922fbb7b AC |
27551 | |
27552 | @subsubheading @value{GDBN} Command | |
27553 | ||
a2c02241 NR |
27554 | The corresponding @value{GDBN} command is @samp{info frame} or @samp{frame} |
27555 | (without arguments). | |
922fbb7b AC |
27556 | |
27557 | @subsubheading Example | |
27558 | ||
27559 | @smallexample | |
594fe323 | 27560 | (gdb) |
a2c02241 NR |
27561 | -stack-info-frame |
27562 | ^done,frame=@{level="1",addr="0x0001076c",func="callee3", | |
27563 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
27564 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@} | |
594fe323 | 27565 | (gdb) |
922fbb7b AC |
27566 | @end smallexample |
27567 | ||
a2c02241 NR |
27568 | @subheading The @code{-stack-info-depth} Command |
27569 | @findex -stack-info-depth | |
922fbb7b AC |
27570 | |
27571 | @subsubheading Synopsis | |
27572 | ||
27573 | @smallexample | |
a2c02241 | 27574 | -stack-info-depth [ @var{max-depth} ] |
922fbb7b AC |
27575 | @end smallexample |
27576 | ||
a2c02241 NR |
27577 | Return the depth of the stack. If the integer argument @var{max-depth} |
27578 | is specified, do not count beyond @var{max-depth} frames. | |
922fbb7b AC |
27579 | |
27580 | @subsubheading @value{GDBN} Command | |
27581 | ||
a2c02241 | 27582 | There's no equivalent @value{GDBN} command. |
922fbb7b AC |
27583 | |
27584 | @subsubheading Example | |
27585 | ||
a2c02241 NR |
27586 | For a stack with frame levels 0 through 11: |
27587 | ||
922fbb7b | 27588 | @smallexample |
594fe323 | 27589 | (gdb) |
a2c02241 NR |
27590 | -stack-info-depth |
27591 | ^done,depth="12" | |
594fe323 | 27592 | (gdb) |
a2c02241 NR |
27593 | -stack-info-depth 4 |
27594 | ^done,depth="4" | |
594fe323 | 27595 | (gdb) |
a2c02241 NR |
27596 | -stack-info-depth 12 |
27597 | ^done,depth="12" | |
594fe323 | 27598 | (gdb) |
a2c02241 NR |
27599 | -stack-info-depth 11 |
27600 | ^done,depth="11" | |
594fe323 | 27601 | (gdb) |
a2c02241 NR |
27602 | -stack-info-depth 13 |
27603 | ^done,depth="12" | |
594fe323 | 27604 | (gdb) |
922fbb7b AC |
27605 | @end smallexample |
27606 | ||
1e611234 | 27607 | @anchor{-stack-list-arguments} |
a2c02241 NR |
27608 | @subheading The @code{-stack-list-arguments} Command |
27609 | @findex -stack-list-arguments | |
922fbb7b AC |
27610 | |
27611 | @subsubheading Synopsis | |
27612 | ||
27613 | @smallexample | |
6211c335 | 27614 | -stack-list-arguments [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values} |
a2c02241 | 27615 | [ @var{low-frame} @var{high-frame} ] |
922fbb7b AC |
27616 | @end smallexample |
27617 | ||
a2c02241 NR |
27618 | Display a list of the arguments for the frames between @var{low-frame} |
27619 | and @var{high-frame} (inclusive). If @var{low-frame} and | |
2f1acb09 VP |
27620 | @var{high-frame} are not provided, list the arguments for the whole |
27621 | call stack. If the two arguments are equal, show the single frame | |
27622 | at the corresponding level. It is an error if @var{low-frame} is | |
27623 | larger than the actual number of frames. On the other hand, | |
27624 | @var{high-frame} may be larger than the actual number of frames, in | |
27625 | which case only existing frames will be returned. | |
a2c02241 | 27626 | |
3afae151 VP |
27627 | If @var{print-values} is 0 or @code{--no-values}, print only the names of |
27628 | the variables; if it is 1 or @code{--all-values}, print also their | |
27629 | values; and if it is 2 or @code{--simple-values}, print the name, | |
27630 | type and value for simple data types, and the name and type for arrays, | |
1e611234 PM |
27631 | structures and unions. If the option @code{--no-frame-filters} is |
27632 | supplied, then Python frame filters will not be executed. | |
27633 | ||
6211c335 YQ |
27634 | If the @code{--skip-unavailable} option is specified, arguments that |
27635 | are not available are not listed. Partially available arguments | |
27636 | are still displayed, however. | |
922fbb7b | 27637 | |
b3372f91 VP |
27638 | Use of this command to obtain arguments in a single frame is |
27639 | deprecated in favor of the @samp{-stack-list-variables} command. | |
27640 | ||
922fbb7b AC |
27641 | @subsubheading @value{GDBN} Command |
27642 | ||
a2c02241 NR |
27643 | @value{GDBN} does not have an equivalent command. @code{gdbtk} has a |
27644 | @samp{gdb_get_args} command which partially overlaps with the | |
27645 | functionality of @samp{-stack-list-arguments}. | |
922fbb7b AC |
27646 | |
27647 | @subsubheading Example | |
922fbb7b | 27648 | |
a2c02241 | 27649 | @smallexample |
594fe323 | 27650 | (gdb) |
a2c02241 NR |
27651 | -stack-list-frames |
27652 | ^done, | |
27653 | stack=[ | |
27654 | frame=@{level="0",addr="0x00010734",func="callee4", | |
27655 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
27656 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@}, | |
27657 | frame=@{level="1",addr="0x0001076c",func="callee3", | |
27658 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
27659 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@}, | |
27660 | frame=@{level="2",addr="0x0001078c",func="callee2", | |
27661 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
27662 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22"@}, | |
27663 | frame=@{level="3",addr="0x000107b4",func="callee1", | |
27664 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
27665 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27"@}, | |
27666 | frame=@{level="4",addr="0x000107e0",func="main", | |
27667 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
27668 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32"@}] | |
594fe323 | 27669 | (gdb) |
a2c02241 NR |
27670 | -stack-list-arguments 0 |
27671 | ^done, | |
27672 | stack-args=[ | |
27673 | frame=@{level="0",args=[]@}, | |
27674 | frame=@{level="1",args=[name="strarg"]@}, | |
27675 | frame=@{level="2",args=[name="intarg",name="strarg"]@}, | |
27676 | frame=@{level="3",args=[name="intarg",name="strarg",name="fltarg"]@}, | |
27677 | frame=@{level="4",args=[]@}] | |
594fe323 | 27678 | (gdb) |
a2c02241 NR |
27679 | -stack-list-arguments 1 |
27680 | ^done, | |
27681 | stack-args=[ | |
27682 | frame=@{level="0",args=[]@}, | |
27683 | frame=@{level="1", | |
27684 | args=[@{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
27685 | frame=@{level="2",args=[ | |
27686 | @{name="intarg",value="2"@}, | |
27687 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
27688 | @{frame=@{level="3",args=[ | |
27689 | @{name="intarg",value="2"@}, | |
27690 | @{name="strarg",value="0x11940 \"A string argument.\""@}, | |
27691 | @{name="fltarg",value="3.5"@}]@}, | |
27692 | frame=@{level="4",args=[]@}] | |
594fe323 | 27693 | (gdb) |
a2c02241 NR |
27694 | -stack-list-arguments 0 2 2 |
27695 | ^done,stack-args=[frame=@{level="2",args=[name="intarg",name="strarg"]@}] | |
594fe323 | 27696 | (gdb) |
a2c02241 NR |
27697 | -stack-list-arguments 1 2 2 |
27698 | ^done,stack-args=[frame=@{level="2", | |
27699 | args=[@{name="intarg",value="2"@}, | |
27700 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}] | |
594fe323 | 27701 | (gdb) |
a2c02241 NR |
27702 | @end smallexample |
27703 | ||
27704 | @c @subheading -stack-list-exception-handlers | |
922fbb7b | 27705 | |
a2c02241 | 27706 | |
1e611234 | 27707 | @anchor{-stack-list-frames} |
a2c02241 NR |
27708 | @subheading The @code{-stack-list-frames} Command |
27709 | @findex -stack-list-frames | |
1abaf70c BR |
27710 | |
27711 | @subsubheading Synopsis | |
27712 | ||
27713 | @smallexample | |
1e611234 | 27714 | -stack-list-frames [ --no-frame-filters @var{low-frame} @var{high-frame} ] |
1abaf70c BR |
27715 | @end smallexample |
27716 | ||
a2c02241 NR |
27717 | List the frames currently on the stack. For each frame it displays the |
27718 | following info: | |
27719 | ||
27720 | @table @samp | |
27721 | @item @var{level} | |
d3e8051b | 27722 | The frame number, 0 being the topmost frame, i.e., the innermost function. |
a2c02241 NR |
27723 | @item @var{addr} |
27724 | The @code{$pc} value for that frame. | |
27725 | @item @var{func} | |
27726 | Function name. | |
27727 | @item @var{file} | |
27728 | File name of the source file where the function lives. | |
7d288aaa TT |
27729 | @item @var{fullname} |
27730 | The full file name of the source file where the function lives. | |
a2c02241 NR |
27731 | @item @var{line} |
27732 | Line number corresponding to the @code{$pc}. | |
7d288aaa TT |
27733 | @item @var{from} |
27734 | The shared library where this function is defined. This is only given | |
27735 | if the frame's function is not known. | |
a2c02241 NR |
27736 | @end table |
27737 | ||
27738 | If invoked without arguments, this command prints a backtrace for the | |
27739 | whole stack. If given two integer arguments, it shows the frames whose | |
27740 | levels are between the two arguments (inclusive). If the two arguments | |
2ab1eb7a VP |
27741 | are equal, it shows the single frame at the corresponding level. It is |
27742 | an error if @var{low-frame} is larger than the actual number of | |
a5451f4e | 27743 | frames. On the other hand, @var{high-frame} may be larger than the |
1e611234 PM |
27744 | actual number of frames, in which case only existing frames will be |
27745 | returned. If the option @code{--no-frame-filters} is supplied, then | |
27746 | Python frame filters will not be executed. | |
1abaf70c BR |
27747 | |
27748 | @subsubheading @value{GDBN} Command | |
27749 | ||
a2c02241 | 27750 | The corresponding @value{GDBN} commands are @samp{backtrace} and @samp{where}. |
1abaf70c BR |
27751 | |
27752 | @subsubheading Example | |
27753 | ||
a2c02241 NR |
27754 | Full stack backtrace: |
27755 | ||
1abaf70c | 27756 | @smallexample |
594fe323 | 27757 | (gdb) |
a2c02241 NR |
27758 | -stack-list-frames |
27759 | ^done,stack= | |
27760 | [frame=@{level="0",addr="0x0001076c",func="foo", | |
27761 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11"@}, | |
27762 | frame=@{level="1",addr="0x000107a4",func="foo", | |
27763 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27764 | frame=@{level="2",addr="0x000107a4",func="foo", | |
27765 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27766 | frame=@{level="3",addr="0x000107a4",func="foo", | |
27767 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27768 | frame=@{level="4",addr="0x000107a4",func="foo", | |
27769 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27770 | frame=@{level="5",addr="0x000107a4",func="foo", | |
27771 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27772 | frame=@{level="6",addr="0x000107a4",func="foo", | |
27773 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27774 | frame=@{level="7",addr="0x000107a4",func="foo", | |
27775 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27776 | frame=@{level="8",addr="0x000107a4",func="foo", | |
27777 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27778 | frame=@{level="9",addr="0x000107a4",func="foo", | |
27779 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27780 | frame=@{level="10",addr="0x000107a4",func="foo", | |
27781 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27782 | frame=@{level="11",addr="0x00010738",func="main", | |
27783 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4"@}] | |
594fe323 | 27784 | (gdb) |
1abaf70c BR |
27785 | @end smallexample |
27786 | ||
a2c02241 | 27787 | Show frames between @var{low_frame} and @var{high_frame}: |
1abaf70c | 27788 | |
a2c02241 | 27789 | @smallexample |
594fe323 | 27790 | (gdb) |
a2c02241 NR |
27791 | -stack-list-frames 3 5 |
27792 | ^done,stack= | |
27793 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
27794 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27795 | frame=@{level="4",addr="0x000107a4",func="foo", | |
27796 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
27797 | frame=@{level="5",addr="0x000107a4",func="foo", | |
27798 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}] | |
594fe323 | 27799 | (gdb) |
a2c02241 | 27800 | @end smallexample |
922fbb7b | 27801 | |
a2c02241 | 27802 | Show a single frame: |
922fbb7b AC |
27803 | |
27804 | @smallexample | |
594fe323 | 27805 | (gdb) |
a2c02241 NR |
27806 | -stack-list-frames 3 3 |
27807 | ^done,stack= | |
27808 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
27809 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}] | |
594fe323 | 27810 | (gdb) |
922fbb7b AC |
27811 | @end smallexample |
27812 | ||
922fbb7b | 27813 | |
a2c02241 NR |
27814 | @subheading The @code{-stack-list-locals} Command |
27815 | @findex -stack-list-locals | |
1e611234 | 27816 | @anchor{-stack-list-locals} |
57c22c6c | 27817 | |
a2c02241 | 27818 | @subsubheading Synopsis |
922fbb7b AC |
27819 | |
27820 | @smallexample | |
6211c335 | 27821 | -stack-list-locals [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values} |
922fbb7b AC |
27822 | @end smallexample |
27823 | ||
a2c02241 NR |
27824 | Display the local variable names for the selected frame. If |
27825 | @var{print-values} is 0 or @code{--no-values}, print only the names of | |
27826 | the variables; if it is 1 or @code{--all-values}, print also their | |
27827 | values; and if it is 2 or @code{--simple-values}, print the name, | |
3afae151 | 27828 | type and value for simple data types, and the name and type for arrays, |
a2c02241 NR |
27829 | structures and unions. In this last case, a frontend can immediately |
27830 | display the value of simple data types and create variable objects for | |
d3e8051b | 27831 | other data types when the user wishes to explore their values in |
1e611234 PM |
27832 | more detail. If the option @code{--no-frame-filters} is supplied, then |
27833 | Python frame filters will not be executed. | |
922fbb7b | 27834 | |
6211c335 YQ |
27835 | If the @code{--skip-unavailable} option is specified, local variables |
27836 | that are not available are not listed. Partially available local | |
27837 | variables are still displayed, however. | |
27838 | ||
b3372f91 VP |
27839 | This command is deprecated in favor of the |
27840 | @samp{-stack-list-variables} command. | |
27841 | ||
922fbb7b AC |
27842 | @subsubheading @value{GDBN} Command |
27843 | ||
a2c02241 | 27844 | @samp{info locals} in @value{GDBN}, @samp{gdb_get_locals} in @code{gdbtk}. |
922fbb7b AC |
27845 | |
27846 | @subsubheading Example | |
922fbb7b AC |
27847 | |
27848 | @smallexample | |
594fe323 | 27849 | (gdb) |
a2c02241 NR |
27850 | -stack-list-locals 0 |
27851 | ^done,locals=[name="A",name="B",name="C"] | |
594fe323 | 27852 | (gdb) |
a2c02241 NR |
27853 | -stack-list-locals --all-values |
27854 | ^done,locals=[@{name="A",value="1"@},@{name="B",value="2"@}, | |
27855 | @{name="C",value="@{1, 2, 3@}"@}] | |
27856 | -stack-list-locals --simple-values | |
27857 | ^done,locals=[@{name="A",type="int",value="1"@}, | |
27858 | @{name="B",type="int",value="2"@},@{name="C",type="int [3]"@}] | |
594fe323 | 27859 | (gdb) |
922fbb7b AC |
27860 | @end smallexample |
27861 | ||
1e611234 | 27862 | @anchor{-stack-list-variables} |
b3372f91 VP |
27863 | @subheading The @code{-stack-list-variables} Command |
27864 | @findex -stack-list-variables | |
27865 | ||
27866 | @subsubheading Synopsis | |
27867 | ||
27868 | @smallexample | |
6211c335 | 27869 | -stack-list-variables [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values} |
b3372f91 VP |
27870 | @end smallexample |
27871 | ||
27872 | Display the names of local variables and function arguments for the selected frame. If | |
27873 | @var{print-values} is 0 or @code{--no-values}, print only the names of | |
27874 | the variables; if it is 1 or @code{--all-values}, print also their | |
27875 | values; and if it is 2 or @code{--simple-values}, print the name, | |
3afae151 | 27876 | type and value for simple data types, and the name and type for arrays, |
1e611234 PM |
27877 | structures and unions. If the option @code{--no-frame-filters} is |
27878 | supplied, then Python frame filters will not be executed. | |
b3372f91 | 27879 | |
6211c335 YQ |
27880 | If the @code{--skip-unavailable} option is specified, local variables |
27881 | and arguments that are not available are not listed. Partially | |
27882 | available arguments and local variables are still displayed, however. | |
27883 | ||
b3372f91 VP |
27884 | @subsubheading Example |
27885 | ||
27886 | @smallexample | |
27887 | (gdb) | |
27888 | -stack-list-variables --thread 1 --frame 0 --all-values | |
4f412fd0 | 27889 | ^done,variables=[@{name="x",value="11"@},@{name="s",value="@{a = 1, b = 2@}"@}] |
b3372f91 VP |
27890 | (gdb) |
27891 | @end smallexample | |
27892 | ||
922fbb7b | 27893 | |
a2c02241 NR |
27894 | @subheading The @code{-stack-select-frame} Command |
27895 | @findex -stack-select-frame | |
922fbb7b AC |
27896 | |
27897 | @subsubheading Synopsis | |
27898 | ||
27899 | @smallexample | |
a2c02241 | 27900 | -stack-select-frame @var{framenum} |
922fbb7b AC |
27901 | @end smallexample |
27902 | ||
a2c02241 NR |
27903 | Change the selected frame. Select a different frame @var{framenum} on |
27904 | the stack. | |
922fbb7b | 27905 | |
c3b108f7 VP |
27906 | This command in deprecated in favor of passing the @samp{--frame} |
27907 | option to every command. | |
27908 | ||
922fbb7b AC |
27909 | @subsubheading @value{GDBN} Command |
27910 | ||
a2c02241 NR |
27911 | The corresponding @value{GDBN} commands are @samp{frame}, @samp{up}, |
27912 | @samp{down}, @samp{select-frame}, @samp{up-silent}, and @samp{down-silent}. | |
922fbb7b AC |
27913 | |
27914 | @subsubheading Example | |
27915 | ||
27916 | @smallexample | |
594fe323 | 27917 | (gdb) |
a2c02241 | 27918 | -stack-select-frame 2 |
922fbb7b | 27919 | ^done |
594fe323 | 27920 | (gdb) |
922fbb7b AC |
27921 | @end smallexample |
27922 | ||
27923 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
a2c02241 NR |
27924 | @node GDB/MI Variable Objects |
27925 | @section @sc{gdb/mi} Variable Objects | |
922fbb7b | 27926 | |
a1b5960f | 27927 | @ignore |
922fbb7b | 27928 | |
a2c02241 | 27929 | @subheading Motivation for Variable Objects in @sc{gdb/mi} |
922fbb7b | 27930 | |
a2c02241 NR |
27931 | For the implementation of a variable debugger window (locals, watched |
27932 | expressions, etc.), we are proposing the adaptation of the existing code | |
27933 | used by @code{Insight}. | |
922fbb7b | 27934 | |
a2c02241 | 27935 | The two main reasons for that are: |
922fbb7b | 27936 | |
a2c02241 NR |
27937 | @enumerate 1 |
27938 | @item | |
27939 | It has been proven in practice (it is already on its second generation). | |
922fbb7b | 27940 | |
a2c02241 NR |
27941 | @item |
27942 | It will shorten development time (needless to say how important it is | |
27943 | now). | |
27944 | @end enumerate | |
922fbb7b | 27945 | |
a2c02241 NR |
27946 | The original interface was designed to be used by Tcl code, so it was |
27947 | slightly changed so it could be used through @sc{gdb/mi}. This section | |
27948 | describes the @sc{gdb/mi} operations that will be available and gives some | |
27949 | hints about their use. | |
922fbb7b | 27950 | |
a2c02241 NR |
27951 | @emph{Note}: In addition to the set of operations described here, we |
27952 | expect the @sc{gui} implementation of a variable window to require, at | |
27953 | least, the following operations: | |
922fbb7b | 27954 | |
a2c02241 NR |
27955 | @itemize @bullet |
27956 | @item @code{-gdb-show} @code{output-radix} | |
27957 | @item @code{-stack-list-arguments} | |
27958 | @item @code{-stack-list-locals} | |
27959 | @item @code{-stack-select-frame} | |
27960 | @end itemize | |
922fbb7b | 27961 | |
a1b5960f VP |
27962 | @end ignore |
27963 | ||
c8b2f53c | 27964 | @subheading Introduction to Variable Objects |
922fbb7b | 27965 | |
a2c02241 | 27966 | @cindex variable objects in @sc{gdb/mi} |
c8b2f53c VP |
27967 | |
27968 | Variable objects are "object-oriented" MI interface for examining and | |
27969 | changing values of expressions. Unlike some other MI interfaces that | |
27970 | work with expressions, variable objects are specifically designed for | |
27971 | simple and efficient presentation in the frontend. A variable object | |
27972 | is identified by string name. When a variable object is created, the | |
27973 | frontend specifies the expression for that variable object. The | |
27974 | expression can be a simple variable, or it can be an arbitrary complex | |
27975 | expression, and can even involve CPU registers. After creating a | |
27976 | variable object, the frontend can invoke other variable object | |
27977 | operations---for example to obtain or change the value of a variable | |
27978 | object, or to change display format. | |
27979 | ||
27980 | Variable objects have hierarchical tree structure. Any variable object | |
27981 | that corresponds to a composite type, such as structure in C, has | |
27982 | a number of child variable objects, for example corresponding to each | |
27983 | element of a structure. A child variable object can itself have | |
27984 | children, recursively. Recursion ends when we reach | |
25d5ea92 VP |
27985 | leaf variable objects, which always have built-in types. Child variable |
27986 | objects are created only by explicit request, so if a frontend | |
27987 | is not interested in the children of a particular variable object, no | |
27988 | child will be created. | |
c8b2f53c VP |
27989 | |
27990 | For a leaf variable object it is possible to obtain its value as a | |
27991 | string, or set the value from a string. String value can be also | |
27992 | obtained for a non-leaf variable object, but it's generally a string | |
27993 | that only indicates the type of the object, and does not list its | |
27994 | contents. Assignment to a non-leaf variable object is not allowed. | |
27995 | ||
27996 | A frontend does not need to read the values of all variable objects each time | |
27997 | the program stops. Instead, MI provides an update command that lists all | |
27998 | variable objects whose values has changed since the last update | |
27999 | operation. This considerably reduces the amount of data that must | |
25d5ea92 VP |
28000 | be transferred to the frontend. As noted above, children variable |
28001 | objects are created on demand, and only leaf variable objects have a | |
28002 | real value. As result, gdb will read target memory only for leaf | |
28003 | variables that frontend has created. | |
28004 | ||
28005 | The automatic update is not always desirable. For example, a frontend | |
28006 | might want to keep a value of some expression for future reference, | |
28007 | and never update it. For another example, fetching memory is | |
28008 | relatively slow for embedded targets, so a frontend might want | |
28009 | to disable automatic update for the variables that are either not | |
28010 | visible on the screen, or ``closed''. This is possible using so | |
28011 | called ``frozen variable objects''. Such variable objects are never | |
28012 | implicitly updated. | |
922fbb7b | 28013 | |
c3b108f7 VP |
28014 | Variable objects can be either @dfn{fixed} or @dfn{floating}. For the |
28015 | fixed variable object, the expression is parsed when the variable | |
28016 | object is created, including associating identifiers to specific | |
28017 | variables. The meaning of expression never changes. For a floating | |
28018 | variable object the values of variables whose names appear in the | |
28019 | expressions are re-evaluated every time in the context of the current | |
28020 | frame. Consider this example: | |
28021 | ||
28022 | @smallexample | |
28023 | void do_work(...) | |
28024 | @{ | |
28025 | struct work_state state; | |
28026 | ||
28027 | if (...) | |
28028 | do_work(...); | |
28029 | @} | |
28030 | @end smallexample | |
28031 | ||
28032 | If a fixed variable object for the @code{state} variable is created in | |
7a9dd1b2 | 28033 | this function, and we enter the recursive call, the variable |
c3b108f7 VP |
28034 | object will report the value of @code{state} in the top-level |
28035 | @code{do_work} invocation. On the other hand, a floating variable | |
28036 | object will report the value of @code{state} in the current frame. | |
28037 | ||
28038 | If an expression specified when creating a fixed variable object | |
28039 | refers to a local variable, the variable object becomes bound to the | |
28040 | thread and frame in which the variable object is created. When such | |
28041 | variable object is updated, @value{GDBN} makes sure that the | |
28042 | thread/frame combination the variable object is bound to still exists, | |
28043 | and re-evaluates the variable object in context of that thread/frame. | |
28044 | ||
a2c02241 NR |
28045 | The following is the complete set of @sc{gdb/mi} operations defined to |
28046 | access this functionality: | |
922fbb7b | 28047 | |
a2c02241 NR |
28048 | @multitable @columnfractions .4 .6 |
28049 | @item @strong{Operation} | |
28050 | @tab @strong{Description} | |
922fbb7b | 28051 | |
0cc7d26f TT |
28052 | @item @code{-enable-pretty-printing} |
28053 | @tab enable Python-based pretty-printing | |
a2c02241 NR |
28054 | @item @code{-var-create} |
28055 | @tab create a variable object | |
28056 | @item @code{-var-delete} | |
22d8a470 | 28057 | @tab delete the variable object and/or its children |
a2c02241 NR |
28058 | @item @code{-var-set-format} |
28059 | @tab set the display format of this variable | |
28060 | @item @code{-var-show-format} | |
28061 | @tab show the display format of this variable | |
28062 | @item @code{-var-info-num-children} | |
28063 | @tab tells how many children this object has | |
28064 | @item @code{-var-list-children} | |
28065 | @tab return a list of the object's children | |
28066 | @item @code{-var-info-type} | |
28067 | @tab show the type of this variable object | |
28068 | @item @code{-var-info-expression} | |
02142340 VP |
28069 | @tab print parent-relative expression that this variable object represents |
28070 | @item @code{-var-info-path-expression} | |
28071 | @tab print full expression that this variable object represents | |
a2c02241 NR |
28072 | @item @code{-var-show-attributes} |
28073 | @tab is this variable editable? does it exist here? | |
28074 | @item @code{-var-evaluate-expression} | |
28075 | @tab get the value of this variable | |
28076 | @item @code{-var-assign} | |
28077 | @tab set the value of this variable | |
28078 | @item @code{-var-update} | |
28079 | @tab update the variable and its children | |
25d5ea92 VP |
28080 | @item @code{-var-set-frozen} |
28081 | @tab set frozeness attribute | |
0cc7d26f TT |
28082 | @item @code{-var-set-update-range} |
28083 | @tab set range of children to display on update | |
a2c02241 | 28084 | @end multitable |
922fbb7b | 28085 | |
a2c02241 NR |
28086 | In the next subsection we describe each operation in detail and suggest |
28087 | how it can be used. | |
922fbb7b | 28088 | |
a2c02241 | 28089 | @subheading Description And Use of Operations on Variable Objects |
922fbb7b | 28090 | |
0cc7d26f TT |
28091 | @subheading The @code{-enable-pretty-printing} Command |
28092 | @findex -enable-pretty-printing | |
28093 | ||
28094 | @smallexample | |
28095 | -enable-pretty-printing | |
28096 | @end smallexample | |
28097 | ||
28098 | @value{GDBN} allows Python-based visualizers to affect the output of the | |
28099 | MI variable object commands. However, because there was no way to | |
28100 | implement this in a fully backward-compatible way, a front end must | |
28101 | request that this functionality be enabled. | |
28102 | ||
28103 | Once enabled, this feature cannot be disabled. | |
28104 | ||
28105 | Note that if Python support has not been compiled into @value{GDBN}, | |
28106 | this command will still succeed (and do nothing). | |
28107 | ||
f43030c4 TT |
28108 | This feature is currently (as of @value{GDBN} 7.0) experimental, and |
28109 | may work differently in future versions of @value{GDBN}. | |
28110 | ||
a2c02241 NR |
28111 | @subheading The @code{-var-create} Command |
28112 | @findex -var-create | |
ef21caaf | 28113 | |
a2c02241 | 28114 | @subsubheading Synopsis |
ef21caaf | 28115 | |
a2c02241 NR |
28116 | @smallexample |
28117 | -var-create @{@var{name} | "-"@} | |
c3b108f7 | 28118 | @{@var{frame-addr} | "*" | "@@"@} @var{expression} |
a2c02241 NR |
28119 | @end smallexample |
28120 | ||
28121 | This operation creates a variable object, which allows the monitoring of | |
28122 | a variable, the result of an expression, a memory cell or a CPU | |
28123 | register. | |
ef21caaf | 28124 | |
a2c02241 NR |
28125 | The @var{name} parameter is the string by which the object can be |
28126 | referenced. It must be unique. If @samp{-} is specified, the varobj | |
28127 | system will generate a string ``varNNNNNN'' automatically. It will be | |
c3b108f7 | 28128 | unique provided that one does not specify @var{name} of that format. |
a2c02241 | 28129 | The command fails if a duplicate name is found. |
ef21caaf | 28130 | |
a2c02241 NR |
28131 | The frame under which the expression should be evaluated can be |
28132 | specified by @var{frame-addr}. A @samp{*} indicates that the current | |
c3b108f7 VP |
28133 | frame should be used. A @samp{@@} indicates that a floating variable |
28134 | object must be created. | |
922fbb7b | 28135 | |
a2c02241 NR |
28136 | @var{expression} is any expression valid on the current language set (must not |
28137 | begin with a @samp{*}), or one of the following: | |
922fbb7b | 28138 | |
a2c02241 NR |
28139 | @itemize @bullet |
28140 | @item | |
28141 | @samp{*@var{addr}}, where @var{addr} is the address of a memory cell | |
922fbb7b | 28142 | |
a2c02241 NR |
28143 | @item |
28144 | @samp{*@var{addr}-@var{addr}} --- a memory address range (TBD) | |
922fbb7b | 28145 | |
a2c02241 NR |
28146 | @item |
28147 | @samp{$@var{regname}} --- a CPU register name | |
28148 | @end itemize | |
922fbb7b | 28149 | |
0cc7d26f TT |
28150 | @cindex dynamic varobj |
28151 | A varobj's contents may be provided by a Python-based pretty-printer. In this | |
28152 | case the varobj is known as a @dfn{dynamic varobj}. Dynamic varobjs | |
28153 | have slightly different semantics in some cases. If the | |
28154 | @code{-enable-pretty-printing} command is not sent, then @value{GDBN} | |
28155 | will never create a dynamic varobj. This ensures backward | |
28156 | compatibility for existing clients. | |
28157 | ||
a2c02241 | 28158 | @subsubheading Result |
922fbb7b | 28159 | |
0cc7d26f TT |
28160 | This operation returns attributes of the newly-created varobj. These |
28161 | are: | |
28162 | ||
28163 | @table @samp | |
28164 | @item name | |
28165 | The name of the varobj. | |
28166 | ||
28167 | @item numchild | |
28168 | The number of children of the varobj. This number is not necessarily | |
28169 | reliable for a dynamic varobj. Instead, you must examine the | |
28170 | @samp{has_more} attribute. | |
28171 | ||
28172 | @item value | |
28173 | The varobj's scalar value. For a varobj whose type is some sort of | |
28174 | aggregate (e.g., a @code{struct}), or for a dynamic varobj, this value | |
28175 | will not be interesting. | |
28176 | ||
28177 | @item type | |
28178 | The varobj's type. This is a string representation of the type, as | |
8264ba82 AG |
28179 | would be printed by the @value{GDBN} CLI. If @samp{print object} |
28180 | (@pxref{Print Settings, set print object}) is set to @code{on}, the | |
28181 | @emph{actual} (derived) type of the object is shown rather than the | |
28182 | @emph{declared} one. | |
0cc7d26f TT |
28183 | |
28184 | @item thread-id | |
28185 | If a variable object is bound to a specific thread, then this is the | |
28186 | thread's identifier. | |
28187 | ||
28188 | @item has_more | |
28189 | For a dynamic varobj, this indicates whether there appear to be any | |
28190 | children available. For a non-dynamic varobj, this will be 0. | |
28191 | ||
28192 | @item dynamic | |
28193 | This attribute will be present and have the value @samp{1} if the | |
28194 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
28195 | then this attribute will not be present. | |
28196 | ||
28197 | @item displayhint | |
28198 | A dynamic varobj can supply a display hint to the front end. The | |
28199 | value comes directly from the Python pretty-printer object's | |
4c374409 | 28200 | @code{display_hint} method. @xref{Pretty Printing API}. |
0cc7d26f TT |
28201 | @end table |
28202 | ||
28203 | Typical output will look like this: | |
922fbb7b AC |
28204 | |
28205 | @smallexample | |
0cc7d26f TT |
28206 | name="@var{name}",numchild="@var{N}",type="@var{type}",thread-id="@var{M}", |
28207 | has_more="@var{has_more}" | |
dcaaae04 NR |
28208 | @end smallexample |
28209 | ||
a2c02241 NR |
28210 | |
28211 | @subheading The @code{-var-delete} Command | |
28212 | @findex -var-delete | |
922fbb7b AC |
28213 | |
28214 | @subsubheading Synopsis | |
28215 | ||
28216 | @smallexample | |
22d8a470 | 28217 | -var-delete [ -c ] @var{name} |
922fbb7b AC |
28218 | @end smallexample |
28219 | ||
a2c02241 | 28220 | Deletes a previously created variable object and all of its children. |
22d8a470 | 28221 | With the @samp{-c} option, just deletes the children. |
922fbb7b | 28222 | |
a2c02241 | 28223 | Returns an error if the object @var{name} is not found. |
922fbb7b | 28224 | |
922fbb7b | 28225 | |
a2c02241 NR |
28226 | @subheading The @code{-var-set-format} Command |
28227 | @findex -var-set-format | |
922fbb7b | 28228 | |
a2c02241 | 28229 | @subsubheading Synopsis |
922fbb7b AC |
28230 | |
28231 | @smallexample | |
a2c02241 | 28232 | -var-set-format @var{name} @var{format-spec} |
922fbb7b AC |
28233 | @end smallexample |
28234 | ||
a2c02241 NR |
28235 | Sets the output format for the value of the object @var{name} to be |
28236 | @var{format-spec}. | |
28237 | ||
de051565 | 28238 | @anchor{-var-set-format} |
a2c02241 NR |
28239 | The syntax for the @var{format-spec} is as follows: |
28240 | ||
28241 | @smallexample | |
28242 | @var{format-spec} @expansion{} | |
28243 | @{binary | decimal | hexadecimal | octal | natural@} | |
28244 | @end smallexample | |
28245 | ||
c8b2f53c VP |
28246 | The natural format is the default format choosen automatically |
28247 | based on the variable type (like decimal for an @code{int}, hex | |
28248 | for pointers, etc.). | |
28249 | ||
28250 | For a variable with children, the format is set only on the | |
28251 | variable itself, and the children are not affected. | |
a2c02241 NR |
28252 | |
28253 | @subheading The @code{-var-show-format} Command | |
28254 | @findex -var-show-format | |
922fbb7b AC |
28255 | |
28256 | @subsubheading Synopsis | |
28257 | ||
28258 | @smallexample | |
a2c02241 | 28259 | -var-show-format @var{name} |
922fbb7b AC |
28260 | @end smallexample |
28261 | ||
a2c02241 | 28262 | Returns the format used to display the value of the object @var{name}. |
922fbb7b | 28263 | |
a2c02241 NR |
28264 | @smallexample |
28265 | @var{format} @expansion{} | |
28266 | @var{format-spec} | |
28267 | @end smallexample | |
922fbb7b | 28268 | |
922fbb7b | 28269 | |
a2c02241 NR |
28270 | @subheading The @code{-var-info-num-children} Command |
28271 | @findex -var-info-num-children | |
28272 | ||
28273 | @subsubheading Synopsis | |
28274 | ||
28275 | @smallexample | |
28276 | -var-info-num-children @var{name} | |
28277 | @end smallexample | |
28278 | ||
28279 | Returns the number of children of a variable object @var{name}: | |
28280 | ||
28281 | @smallexample | |
28282 | numchild=@var{n} | |
28283 | @end smallexample | |
28284 | ||
0cc7d26f TT |
28285 | Note that this number is not completely reliable for a dynamic varobj. |
28286 | It will return the current number of children, but more children may | |
28287 | be available. | |
28288 | ||
a2c02241 NR |
28289 | |
28290 | @subheading The @code{-var-list-children} Command | |
28291 | @findex -var-list-children | |
28292 | ||
28293 | @subsubheading Synopsis | |
28294 | ||
28295 | @smallexample | |
0cc7d26f | 28296 | -var-list-children [@var{print-values}] @var{name} [@var{from} @var{to}] |
a2c02241 | 28297 | @end smallexample |
b569d230 | 28298 | @anchor{-var-list-children} |
a2c02241 NR |
28299 | |
28300 | Return a list of the children of the specified variable object and | |
28301 | create variable objects for them, if they do not already exist. With | |
f5011d11 | 28302 | a single argument or if @var{print-values} has a value of 0 or |
a2c02241 NR |
28303 | @code{--no-values}, print only the names of the variables; if |
28304 | @var{print-values} is 1 or @code{--all-values}, also print their | |
28305 | values; and if it is 2 or @code{--simple-values} print the name and | |
28306 | value for simple data types and just the name for arrays, structures | |
28307 | and unions. | |
922fbb7b | 28308 | |
0cc7d26f TT |
28309 | @var{from} and @var{to}, if specified, indicate the range of children |
28310 | to report. If @var{from} or @var{to} is less than zero, the range is | |
28311 | reset and all children will be reported. Otherwise, children starting | |
28312 | at @var{from} (zero-based) and up to and excluding @var{to} will be | |
28313 | reported. | |
28314 | ||
28315 | If a child range is requested, it will only affect the current call to | |
28316 | @code{-var-list-children}, but not future calls to @code{-var-update}. | |
28317 | For this, you must instead use @code{-var-set-update-range}. The | |
28318 | intent of this approach is to enable a front end to implement any | |
28319 | update approach it likes; for example, scrolling a view may cause the | |
28320 | front end to request more children with @code{-var-list-children}, and | |
28321 | then the front end could call @code{-var-set-update-range} with a | |
28322 | different range to ensure that future updates are restricted to just | |
28323 | the visible items. | |
28324 | ||
b569d230 EZ |
28325 | For each child the following results are returned: |
28326 | ||
28327 | @table @var | |
28328 | ||
28329 | @item name | |
28330 | Name of the variable object created for this child. | |
28331 | ||
28332 | @item exp | |
28333 | The expression to be shown to the user by the front end to designate this child. | |
28334 | For example this may be the name of a structure member. | |
28335 | ||
0cc7d26f TT |
28336 | For a dynamic varobj, this value cannot be used to form an |
28337 | expression. There is no way to do this at all with a dynamic varobj. | |
28338 | ||
b569d230 EZ |
28339 | For C/C@t{++} structures there are several pseudo children returned to |
28340 | designate access qualifiers. For these pseudo children @var{exp} is | |
28341 | @samp{public}, @samp{private}, or @samp{protected}. In this case the | |
28342 | type and value are not present. | |
28343 | ||
0cc7d26f TT |
28344 | A dynamic varobj will not report the access qualifying |
28345 | pseudo-children, regardless of the language. This information is not | |
28346 | available at all with a dynamic varobj. | |
28347 | ||
b569d230 | 28348 | @item numchild |
0cc7d26f TT |
28349 | Number of children this child has. For a dynamic varobj, this will be |
28350 | 0. | |
b569d230 EZ |
28351 | |
28352 | @item type | |
8264ba82 AG |
28353 | The type of the child. If @samp{print object} |
28354 | (@pxref{Print Settings, set print object}) is set to @code{on}, the | |
28355 | @emph{actual} (derived) type of the object is shown rather than the | |
28356 | @emph{declared} one. | |
b569d230 EZ |
28357 | |
28358 | @item value | |
28359 | If values were requested, this is the value. | |
28360 | ||
28361 | @item thread-id | |
28362 | If this variable object is associated with a thread, this is the thread id. | |
28363 | Otherwise this result is not present. | |
28364 | ||
28365 | @item frozen | |
28366 | If the variable object is frozen, this variable will be present with a value of 1. | |
c78feb39 | 28367 | |
9df9dbe0 YQ |
28368 | @item displayhint |
28369 | A dynamic varobj can supply a display hint to the front end. The | |
28370 | value comes directly from the Python pretty-printer object's | |
28371 | @code{display_hint} method. @xref{Pretty Printing API}. | |
28372 | ||
c78feb39 YQ |
28373 | @item dynamic |
28374 | This attribute will be present and have the value @samp{1} if the | |
28375 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
28376 | then this attribute will not be present. | |
28377 | ||
b569d230 EZ |
28378 | @end table |
28379 | ||
0cc7d26f TT |
28380 | The result may have its own attributes: |
28381 | ||
28382 | @table @samp | |
28383 | @item displayhint | |
28384 | A dynamic varobj can supply a display hint to the front end. The | |
28385 | value comes directly from the Python pretty-printer object's | |
4c374409 | 28386 | @code{display_hint} method. @xref{Pretty Printing API}. |
0cc7d26f TT |
28387 | |
28388 | @item has_more | |
28389 | This is an integer attribute which is nonzero if there are children | |
28390 | remaining after the end of the selected range. | |
28391 | @end table | |
28392 | ||
922fbb7b AC |
28393 | @subsubheading Example |
28394 | ||
28395 | @smallexample | |
594fe323 | 28396 | (gdb) |
a2c02241 | 28397 | -var-list-children n |
b569d230 | 28398 | ^done,numchild=@var{n},children=[child=@{name=@var{name},exp=@var{exp}, |
a2c02241 | 28399 | numchild=@var{n},type=@var{type}@},@r{(repeats N times)}] |
594fe323 | 28400 | (gdb) |
a2c02241 | 28401 | -var-list-children --all-values n |
b569d230 | 28402 | ^done,numchild=@var{n},children=[child=@{name=@var{name},exp=@var{exp}, |
a2c02241 | 28403 | numchild=@var{n},value=@var{value},type=@var{type}@},@r{(repeats N times)}] |
922fbb7b AC |
28404 | @end smallexample |
28405 | ||
922fbb7b | 28406 | |
a2c02241 NR |
28407 | @subheading The @code{-var-info-type} Command |
28408 | @findex -var-info-type | |
922fbb7b | 28409 | |
a2c02241 NR |
28410 | @subsubheading Synopsis |
28411 | ||
28412 | @smallexample | |
28413 | -var-info-type @var{name} | |
28414 | @end smallexample | |
28415 | ||
28416 | Returns the type of the specified variable @var{name}. The type is | |
28417 | returned as a string in the same format as it is output by the | |
28418 | @value{GDBN} CLI: | |
28419 | ||
28420 | @smallexample | |
28421 | type=@var{typename} | |
28422 | @end smallexample | |
28423 | ||
28424 | ||
28425 | @subheading The @code{-var-info-expression} Command | |
28426 | @findex -var-info-expression | |
922fbb7b AC |
28427 | |
28428 | @subsubheading Synopsis | |
28429 | ||
28430 | @smallexample | |
a2c02241 | 28431 | -var-info-expression @var{name} |
922fbb7b AC |
28432 | @end smallexample |
28433 | ||
02142340 VP |
28434 | Returns a string that is suitable for presenting this |
28435 | variable object in user interface. The string is generally | |
28436 | not valid expression in the current language, and cannot be evaluated. | |
28437 | ||
28438 | For example, if @code{a} is an array, and variable object | |
28439 | @code{A} was created for @code{a}, then we'll get this output: | |
922fbb7b | 28440 | |
a2c02241 | 28441 | @smallexample |
02142340 VP |
28442 | (gdb) -var-info-expression A.1 |
28443 | ^done,lang="C",exp="1" | |
a2c02241 | 28444 | @end smallexample |
922fbb7b | 28445 | |
a2c02241 | 28446 | @noindent |
fa4d0c40 YQ |
28447 | Here, the value of @code{lang} is the language name, which can be |
28448 | found in @ref{Supported Languages}. | |
02142340 VP |
28449 | |
28450 | Note that the output of the @code{-var-list-children} command also | |
28451 | includes those expressions, so the @code{-var-info-expression} command | |
28452 | is of limited use. | |
28453 | ||
28454 | @subheading The @code{-var-info-path-expression} Command | |
28455 | @findex -var-info-path-expression | |
28456 | ||
28457 | @subsubheading Synopsis | |
28458 | ||
28459 | @smallexample | |
28460 | -var-info-path-expression @var{name} | |
28461 | @end smallexample | |
28462 | ||
28463 | Returns an expression that can be evaluated in the current | |
28464 | context and will yield the same value that a variable object has. | |
28465 | Compare this with the @code{-var-info-expression} command, which | |
28466 | result can be used only for UI presentation. Typical use of | |
28467 | the @code{-var-info-path-expression} command is creating a | |
28468 | watchpoint from a variable object. | |
28469 | ||
0cc7d26f TT |
28470 | This command is currently not valid for children of a dynamic varobj, |
28471 | and will give an error when invoked on one. | |
28472 | ||
02142340 VP |
28473 | For example, suppose @code{C} is a C@t{++} class, derived from class |
28474 | @code{Base}, and that the @code{Base} class has a member called | |
28475 | @code{m_size}. Assume a variable @code{c} is has the type of | |
28476 | @code{C} and a variable object @code{C} was created for variable | |
28477 | @code{c}. Then, we'll get this output: | |
28478 | @smallexample | |
28479 | (gdb) -var-info-path-expression C.Base.public.m_size | |
28480 | ^done,path_expr=((Base)c).m_size) | |
28481 | @end smallexample | |
922fbb7b | 28482 | |
a2c02241 NR |
28483 | @subheading The @code{-var-show-attributes} Command |
28484 | @findex -var-show-attributes | |
922fbb7b | 28485 | |
a2c02241 | 28486 | @subsubheading Synopsis |
922fbb7b | 28487 | |
a2c02241 NR |
28488 | @smallexample |
28489 | -var-show-attributes @var{name} | |
28490 | @end smallexample | |
922fbb7b | 28491 | |
a2c02241 | 28492 | List attributes of the specified variable object @var{name}: |
922fbb7b AC |
28493 | |
28494 | @smallexample | |
a2c02241 | 28495 | status=@var{attr} [ ( ,@var{attr} )* ] |
922fbb7b AC |
28496 | @end smallexample |
28497 | ||
a2c02241 NR |
28498 | @noindent |
28499 | where @var{attr} is @code{@{ @{ editable | noneditable @} | TBD @}}. | |
28500 | ||
28501 | @subheading The @code{-var-evaluate-expression} Command | |
28502 | @findex -var-evaluate-expression | |
28503 | ||
28504 | @subsubheading Synopsis | |
28505 | ||
28506 | @smallexample | |
de051565 | 28507 | -var-evaluate-expression [-f @var{format-spec}] @var{name} |
a2c02241 NR |
28508 | @end smallexample |
28509 | ||
28510 | Evaluates the expression that is represented by the specified variable | |
de051565 MK |
28511 | object and returns its value as a string. The format of the string |
28512 | can be specified with the @samp{-f} option. The possible values of | |
28513 | this option are the same as for @code{-var-set-format} | |
28514 | (@pxref{-var-set-format}). If the @samp{-f} option is not specified, | |
28515 | the current display format will be used. The current display format | |
28516 | can be changed using the @code{-var-set-format} command. | |
a2c02241 NR |
28517 | |
28518 | @smallexample | |
28519 | value=@var{value} | |
28520 | @end smallexample | |
28521 | ||
28522 | Note that one must invoke @code{-var-list-children} for a variable | |
28523 | before the value of a child variable can be evaluated. | |
28524 | ||
28525 | @subheading The @code{-var-assign} Command | |
28526 | @findex -var-assign | |
28527 | ||
28528 | @subsubheading Synopsis | |
28529 | ||
28530 | @smallexample | |
28531 | -var-assign @var{name} @var{expression} | |
28532 | @end smallexample | |
28533 | ||
28534 | Assigns the value of @var{expression} to the variable object specified | |
28535 | by @var{name}. The object must be @samp{editable}. If the variable's | |
28536 | value is altered by the assign, the variable will show up in any | |
28537 | subsequent @code{-var-update} list. | |
28538 | ||
28539 | @subsubheading Example | |
922fbb7b AC |
28540 | |
28541 | @smallexample | |
594fe323 | 28542 | (gdb) |
a2c02241 NR |
28543 | -var-assign var1 3 |
28544 | ^done,value="3" | |
594fe323 | 28545 | (gdb) |
a2c02241 NR |
28546 | -var-update * |
28547 | ^done,changelist=[@{name="var1",in_scope="true",type_changed="false"@}] | |
594fe323 | 28548 | (gdb) |
922fbb7b AC |
28549 | @end smallexample |
28550 | ||
a2c02241 NR |
28551 | @subheading The @code{-var-update} Command |
28552 | @findex -var-update | |
28553 | ||
28554 | @subsubheading Synopsis | |
28555 | ||
28556 | @smallexample | |
28557 | -var-update [@var{print-values}] @{@var{name} | "*"@} | |
28558 | @end smallexample | |
28559 | ||
c8b2f53c VP |
28560 | Reevaluate the expressions corresponding to the variable object |
28561 | @var{name} and all its direct and indirect children, and return the | |
36ece8b3 NR |
28562 | list of variable objects whose values have changed; @var{name} must |
28563 | be a root variable object. Here, ``changed'' means that the result of | |
28564 | @code{-var-evaluate-expression} before and after the | |
28565 | @code{-var-update} is different. If @samp{*} is used as the variable | |
9f708cb2 VP |
28566 | object names, all existing variable objects are updated, except |
28567 | for frozen ones (@pxref{-var-set-frozen}). The option | |
36ece8b3 | 28568 | @var{print-values} determines whether both names and values, or just |
de051565 | 28569 | names are printed. The possible values of this option are the same |
36ece8b3 NR |
28570 | as for @code{-var-list-children} (@pxref{-var-list-children}). It is |
28571 | recommended to use the @samp{--all-values} option, to reduce the | |
28572 | number of MI commands needed on each program stop. | |
c8b2f53c | 28573 | |
c3b108f7 VP |
28574 | With the @samp{*} parameter, if a variable object is bound to a |
28575 | currently running thread, it will not be updated, without any | |
28576 | diagnostic. | |
a2c02241 | 28577 | |
0cc7d26f TT |
28578 | If @code{-var-set-update-range} was previously used on a varobj, then |
28579 | only the selected range of children will be reported. | |
922fbb7b | 28580 | |
0cc7d26f TT |
28581 | @code{-var-update} reports all the changed varobjs in a tuple named |
28582 | @samp{changelist}. | |
28583 | ||
28584 | Each item in the change list is itself a tuple holding: | |
28585 | ||
28586 | @table @samp | |
28587 | @item name | |
28588 | The name of the varobj. | |
28589 | ||
28590 | @item value | |
28591 | If values were requested for this update, then this field will be | |
28592 | present and will hold the value of the varobj. | |
922fbb7b | 28593 | |
0cc7d26f | 28594 | @item in_scope |
9f708cb2 | 28595 | @anchor{-var-update} |
0cc7d26f | 28596 | This field is a string which may take one of three values: |
36ece8b3 NR |
28597 | |
28598 | @table @code | |
28599 | @item "true" | |
28600 | The variable object's current value is valid. | |
28601 | ||
28602 | @item "false" | |
28603 | The variable object does not currently hold a valid value but it may | |
28604 | hold one in the future if its associated expression comes back into | |
28605 | scope. | |
28606 | ||
28607 | @item "invalid" | |
28608 | The variable object no longer holds a valid value. | |
28609 | This can occur when the executable file being debugged has changed, | |
28610 | either through recompilation or by using the @value{GDBN} @code{file} | |
28611 | command. The front end should normally choose to delete these variable | |
28612 | objects. | |
28613 | @end table | |
28614 | ||
28615 | In the future new values may be added to this list so the front should | |
28616 | be prepared for this possibility. @xref{GDB/MI Development and Front Ends, ,@sc{GDB/MI} Development and Front Ends}. | |
28617 | ||
0cc7d26f TT |
28618 | @item type_changed |
28619 | This is only present if the varobj is still valid. If the type | |
28620 | changed, then this will be the string @samp{true}; otherwise it will | |
28621 | be @samp{false}. | |
28622 | ||
7191c139 JB |
28623 | When a varobj's type changes, its children are also likely to have |
28624 | become incorrect. Therefore, the varobj's children are automatically | |
28625 | deleted when this attribute is @samp{true}. Also, the varobj's update | |
28626 | range, when set using the @code{-var-set-update-range} command, is | |
28627 | unset. | |
28628 | ||
0cc7d26f TT |
28629 | @item new_type |
28630 | If the varobj's type changed, then this field will be present and will | |
28631 | hold the new type. | |
28632 | ||
28633 | @item new_num_children | |
28634 | For a dynamic varobj, if the number of children changed, or if the | |
28635 | type changed, this will be the new number of children. | |
28636 | ||
28637 | The @samp{numchild} field in other varobj responses is generally not | |
28638 | valid for a dynamic varobj -- it will show the number of children that | |
28639 | @value{GDBN} knows about, but because dynamic varobjs lazily | |
28640 | instantiate their children, this will not reflect the number of | |
28641 | children which may be available. | |
28642 | ||
28643 | The @samp{new_num_children} attribute only reports changes to the | |
28644 | number of children known by @value{GDBN}. This is the only way to | |
28645 | detect whether an update has removed children (which necessarily can | |
28646 | only happen at the end of the update range). | |
28647 | ||
28648 | @item displayhint | |
28649 | The display hint, if any. | |
28650 | ||
28651 | @item has_more | |
28652 | This is an integer value, which will be 1 if there are more children | |
28653 | available outside the varobj's update range. | |
28654 | ||
28655 | @item dynamic | |
28656 | This attribute will be present and have the value @samp{1} if the | |
28657 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
28658 | then this attribute will not be present. | |
28659 | ||
28660 | @item new_children | |
28661 | If new children were added to a dynamic varobj within the selected | |
28662 | update range (as set by @code{-var-set-update-range}), then they will | |
28663 | be listed in this attribute. | |
28664 | @end table | |
28665 | ||
28666 | @subsubheading Example | |
28667 | ||
28668 | @smallexample | |
28669 | (gdb) | |
28670 | -var-assign var1 3 | |
28671 | ^done,value="3" | |
28672 | (gdb) | |
28673 | -var-update --all-values var1 | |
28674 | ^done,changelist=[@{name="var1",value="3",in_scope="true", | |
28675 | type_changed="false"@}] | |
28676 | (gdb) | |
28677 | @end smallexample | |
28678 | ||
25d5ea92 VP |
28679 | @subheading The @code{-var-set-frozen} Command |
28680 | @findex -var-set-frozen | |
9f708cb2 | 28681 | @anchor{-var-set-frozen} |
25d5ea92 VP |
28682 | |
28683 | @subsubheading Synopsis | |
28684 | ||
28685 | @smallexample | |
9f708cb2 | 28686 | -var-set-frozen @var{name} @var{flag} |
25d5ea92 VP |
28687 | @end smallexample |
28688 | ||
9f708cb2 | 28689 | Set the frozenness flag on the variable object @var{name}. The |
25d5ea92 | 28690 | @var{flag} parameter should be either @samp{1} to make the variable |
9f708cb2 | 28691 | frozen or @samp{0} to make it unfrozen. If a variable object is |
25d5ea92 | 28692 | frozen, then neither itself, nor any of its children, are |
9f708cb2 | 28693 | implicitly updated by @code{-var-update} of |
25d5ea92 VP |
28694 | a parent variable or by @code{-var-update *}. Only |
28695 | @code{-var-update} of the variable itself will update its value and | |
28696 | values of its children. After a variable object is unfrozen, it is | |
28697 | implicitly updated by all subsequent @code{-var-update} operations. | |
28698 | Unfreezing a variable does not update it, only subsequent | |
28699 | @code{-var-update} does. | |
28700 | ||
28701 | @subsubheading Example | |
28702 | ||
28703 | @smallexample | |
28704 | (gdb) | |
28705 | -var-set-frozen V 1 | |
28706 | ^done | |
28707 | (gdb) | |
28708 | @end smallexample | |
28709 | ||
0cc7d26f TT |
28710 | @subheading The @code{-var-set-update-range} command |
28711 | @findex -var-set-update-range | |
28712 | @anchor{-var-set-update-range} | |
28713 | ||
28714 | @subsubheading Synopsis | |
28715 | ||
28716 | @smallexample | |
28717 | -var-set-update-range @var{name} @var{from} @var{to} | |
28718 | @end smallexample | |
28719 | ||
28720 | Set the range of children to be returned by future invocations of | |
28721 | @code{-var-update}. | |
28722 | ||
28723 | @var{from} and @var{to} indicate the range of children to report. If | |
28724 | @var{from} or @var{to} is less than zero, the range is reset and all | |
28725 | children will be reported. Otherwise, children starting at @var{from} | |
28726 | (zero-based) and up to and excluding @var{to} will be reported. | |
28727 | ||
28728 | @subsubheading Example | |
28729 | ||
28730 | @smallexample | |
28731 | (gdb) | |
28732 | -var-set-update-range V 1 2 | |
28733 | ^done | |
28734 | @end smallexample | |
28735 | ||
b6313243 TT |
28736 | @subheading The @code{-var-set-visualizer} command |
28737 | @findex -var-set-visualizer | |
28738 | @anchor{-var-set-visualizer} | |
28739 | ||
28740 | @subsubheading Synopsis | |
28741 | ||
28742 | @smallexample | |
28743 | -var-set-visualizer @var{name} @var{visualizer} | |
28744 | @end smallexample | |
28745 | ||
28746 | Set a visualizer for the variable object @var{name}. | |
28747 | ||
28748 | @var{visualizer} is the visualizer to use. The special value | |
28749 | @samp{None} means to disable any visualizer in use. | |
28750 | ||
28751 | If not @samp{None}, @var{visualizer} must be a Python expression. | |
28752 | This expression must evaluate to a callable object which accepts a | |
28753 | single argument. @value{GDBN} will call this object with the value of | |
28754 | the varobj @var{name} as an argument (this is done so that the same | |
28755 | Python pretty-printing code can be used for both the CLI and MI). | |
28756 | When called, this object must return an object which conforms to the | |
4c374409 | 28757 | pretty-printing interface (@pxref{Pretty Printing API}). |
b6313243 TT |
28758 | |
28759 | The pre-defined function @code{gdb.default_visualizer} may be used to | |
28760 | select a visualizer by following the built-in process | |
28761 | (@pxref{Selecting Pretty-Printers}). This is done automatically when | |
28762 | a varobj is created, and so ordinarily is not needed. | |
28763 | ||
28764 | This feature is only available if Python support is enabled. The MI | |
d192b373 | 28765 | command @code{-list-features} (@pxref{GDB/MI Support Commands}) |
b6313243 TT |
28766 | can be used to check this. |
28767 | ||
28768 | @subsubheading Example | |
28769 | ||
28770 | Resetting the visualizer: | |
28771 | ||
28772 | @smallexample | |
28773 | (gdb) | |
28774 | -var-set-visualizer V None | |
28775 | ^done | |
28776 | @end smallexample | |
28777 | ||
28778 | Reselecting the default (type-based) visualizer: | |
28779 | ||
28780 | @smallexample | |
28781 | (gdb) | |
28782 | -var-set-visualizer V gdb.default_visualizer | |
28783 | ^done | |
28784 | @end smallexample | |
28785 | ||
28786 | Suppose @code{SomeClass} is a visualizer class. A lambda expression | |
28787 | can be used to instantiate this class for a varobj: | |
28788 | ||
28789 | @smallexample | |
28790 | (gdb) | |
28791 | -var-set-visualizer V "lambda val: SomeClass()" | |
28792 | ^done | |
28793 | @end smallexample | |
25d5ea92 | 28794 | |
a2c02241 NR |
28795 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
28796 | @node GDB/MI Data Manipulation | |
28797 | @section @sc{gdb/mi} Data Manipulation | |
922fbb7b | 28798 | |
a2c02241 NR |
28799 | @cindex data manipulation, in @sc{gdb/mi} |
28800 | @cindex @sc{gdb/mi}, data manipulation | |
28801 | This section describes the @sc{gdb/mi} commands that manipulate data: | |
28802 | examine memory and registers, evaluate expressions, etc. | |
28803 | ||
28804 | @c REMOVED FROM THE INTERFACE. | |
28805 | @c @subheading -data-assign | |
28806 | @c Change the value of a program variable. Plenty of side effects. | |
79a6e687 | 28807 | @c @subsubheading GDB Command |
a2c02241 NR |
28808 | @c set variable |
28809 | @c @subsubheading Example | |
28810 | @c N.A. | |
28811 | ||
28812 | @subheading The @code{-data-disassemble} Command | |
28813 | @findex -data-disassemble | |
922fbb7b AC |
28814 | |
28815 | @subsubheading Synopsis | |
28816 | ||
28817 | @smallexample | |
a2c02241 NR |
28818 | -data-disassemble |
28819 | [ -s @var{start-addr} -e @var{end-addr} ] | |
28820 | | [ -f @var{filename} -l @var{linenum} [ -n @var{lines} ] ] | |
28821 | -- @var{mode} | |
922fbb7b AC |
28822 | @end smallexample |
28823 | ||
a2c02241 NR |
28824 | @noindent |
28825 | Where: | |
28826 | ||
28827 | @table @samp | |
28828 | @item @var{start-addr} | |
28829 | is the beginning address (or @code{$pc}) | |
28830 | @item @var{end-addr} | |
28831 | is the end address | |
28832 | @item @var{filename} | |
28833 | is the name of the file to disassemble | |
28834 | @item @var{linenum} | |
28835 | is the line number to disassemble around | |
28836 | @item @var{lines} | |
d3e8051b | 28837 | is the number of disassembly lines to be produced. If it is -1, |
a2c02241 NR |
28838 | the whole function will be disassembled, in case no @var{end-addr} is |
28839 | specified. If @var{end-addr} is specified as a non-zero value, and | |
28840 | @var{lines} is lower than the number of disassembly lines between | |
28841 | @var{start-addr} and @var{end-addr}, only @var{lines} lines are | |
28842 | displayed; if @var{lines} is higher than the number of lines between | |
28843 | @var{start-addr} and @var{end-addr}, only the lines up to @var{end-addr} | |
28844 | are displayed. | |
28845 | @item @var{mode} | |
b716877b AB |
28846 | is either 0 (meaning only disassembly), 1 (meaning mixed source and |
28847 | disassembly), 2 (meaning disassembly with raw opcodes), or 3 (meaning | |
28848 | mixed source and disassembly with raw opcodes). | |
a2c02241 NR |
28849 | @end table |
28850 | ||
28851 | @subsubheading Result | |
28852 | ||
ed8a1c2d AB |
28853 | The result of the @code{-data-disassemble} command will be a list named |
28854 | @samp{asm_insns}, the contents of this list depend on the @var{mode} | |
28855 | used with the @code{-data-disassemble} command. | |
a2c02241 | 28856 | |
ed8a1c2d AB |
28857 | For modes 0 and 2 the @samp{asm_insns} list contains tuples with the |
28858 | following fields: | |
28859 | ||
28860 | @table @code | |
28861 | @item address | |
28862 | The address at which this instruction was disassembled. | |
28863 | ||
28864 | @item func-name | |
28865 | The name of the function this instruction is within. | |
28866 | ||
28867 | @item offset | |
28868 | The decimal offset in bytes from the start of @samp{func-name}. | |
28869 | ||
28870 | @item inst | |
28871 | The text disassembly for this @samp{address}. | |
28872 | ||
28873 | @item opcodes | |
28874 | This field is only present for mode 2. This contains the raw opcode | |
28875 | bytes for the @samp{inst} field. | |
28876 | ||
28877 | @end table | |
28878 | ||
28879 | For modes 1 and 3 the @samp{asm_insns} list contains tuples named | |
28880 | @samp{src_and_asm_line}, each of which has the following fields: | |
a2c02241 | 28881 | |
ed8a1c2d AB |
28882 | @table @code |
28883 | @item line | |
28884 | The line number within @samp{file}. | |
28885 | ||
28886 | @item file | |
28887 | The file name from the compilation unit. This might be an absolute | |
28888 | file name or a relative file name depending on the compile command | |
28889 | used. | |
28890 | ||
28891 | @item fullname | |
f35a17b5 JK |
28892 | Absolute file name of @samp{file}. It is converted to a canonical form |
28893 | using the source file search path | |
28894 | (@pxref{Source Path, ,Specifying Source Directories}) | |
28895 | and after resolving all the symbolic links. | |
28896 | ||
28897 | If the source file is not found this field will contain the path as | |
28898 | present in the debug information. | |
ed8a1c2d AB |
28899 | |
28900 | @item line_asm_insn | |
28901 | This is a list of tuples containing the disassembly for @samp{line} in | |
28902 | @samp{file}. The fields of each tuple are the same as for | |
28903 | @code{-data-disassemble} in @var{mode} 0 and 2, so @samp{address}, | |
28904 | @samp{func-name}, @samp{offset}, @samp{inst}, and optionally | |
28905 | @samp{opcodes}. | |
28906 | ||
28907 | @end table | |
28908 | ||
28909 | Note that whatever included in the @samp{inst} field, is not | |
28910 | manipulated directly by @sc{gdb/mi}, i.e., it is not possible to | |
28911 | adjust its format. | |
922fbb7b AC |
28912 | |
28913 | @subsubheading @value{GDBN} Command | |
28914 | ||
ed8a1c2d | 28915 | The corresponding @value{GDBN} command is @samp{disassemble}. |
922fbb7b AC |
28916 | |
28917 | @subsubheading Example | |
28918 | ||
a2c02241 NR |
28919 | Disassemble from the current value of @code{$pc} to @code{$pc + 20}: |
28920 | ||
922fbb7b | 28921 | @smallexample |
594fe323 | 28922 | (gdb) |
a2c02241 NR |
28923 | -data-disassemble -s $pc -e "$pc + 20" -- 0 |
28924 | ^done, | |
28925 | asm_insns=[ | |
28926 | @{address="0x000107c0",func-name="main",offset="4", | |
28927 | inst="mov 2, %o0"@}, | |
28928 | @{address="0x000107c4",func-name="main",offset="8", | |
28929 | inst="sethi %hi(0x11800), %o2"@}, | |
28930 | @{address="0x000107c8",func-name="main",offset="12", | |
28931 | inst="or %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"@}, | |
28932 | @{address="0x000107cc",func-name="main",offset="16", | |
28933 | inst="sethi %hi(0x11800), %o2"@}, | |
28934 | @{address="0x000107d0",func-name="main",offset="20", | |
28935 | inst="or %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"@}] | |
594fe323 | 28936 | (gdb) |
a2c02241 NR |
28937 | @end smallexample |
28938 | ||
28939 | Disassemble the whole @code{main} function. Line 32 is part of | |
28940 | @code{main}. | |
28941 | ||
28942 | @smallexample | |
28943 | -data-disassemble -f basics.c -l 32 -- 0 | |
28944 | ^done,asm_insns=[ | |
28945 | @{address="0x000107bc",func-name="main",offset="0", | |
28946 | inst="save %sp, -112, %sp"@}, | |
28947 | @{address="0x000107c0",func-name="main",offset="4", | |
28948 | inst="mov 2, %o0"@}, | |
28949 | @{address="0x000107c4",func-name="main",offset="8", | |
28950 | inst="sethi %hi(0x11800), %o2"@}, | |
28951 | [@dots{}] | |
28952 | @{address="0x0001081c",func-name="main",offset="96",inst="ret "@}, | |
28953 | @{address="0x00010820",func-name="main",offset="100",inst="restore "@}] | |
594fe323 | 28954 | (gdb) |
922fbb7b AC |
28955 | @end smallexample |
28956 | ||
a2c02241 | 28957 | Disassemble 3 instructions from the start of @code{main}: |
922fbb7b | 28958 | |
a2c02241 | 28959 | @smallexample |
594fe323 | 28960 | (gdb) |
a2c02241 NR |
28961 | -data-disassemble -f basics.c -l 32 -n 3 -- 0 |
28962 | ^done,asm_insns=[ | |
28963 | @{address="0x000107bc",func-name="main",offset="0", | |
28964 | inst="save %sp, -112, %sp"@}, | |
28965 | @{address="0x000107c0",func-name="main",offset="4", | |
28966 | inst="mov 2, %o0"@}, | |
28967 | @{address="0x000107c4",func-name="main",offset="8", | |
28968 | inst="sethi %hi(0x11800), %o2"@}] | |
594fe323 | 28969 | (gdb) |
a2c02241 NR |
28970 | @end smallexample |
28971 | ||
28972 | Disassemble 3 instructions from the start of @code{main} in mixed mode: | |
28973 | ||
28974 | @smallexample | |
594fe323 | 28975 | (gdb) |
a2c02241 NR |
28976 | -data-disassemble -f basics.c -l 32 -n 3 -- 1 |
28977 | ^done,asm_insns=[ | |
28978 | src_and_asm_line=@{line="31", | |
ed8a1c2d AB |
28979 | file="../../../src/gdb/testsuite/gdb.mi/basics.c", |
28980 | fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c", | |
28981 | line_asm_insn=[@{address="0x000107bc", | |
28982 | func-name="main",offset="0",inst="save %sp, -112, %sp"@}]@}, | |
a2c02241 | 28983 | src_and_asm_line=@{line="32", |
ed8a1c2d AB |
28984 | file="../../../src/gdb/testsuite/gdb.mi/basics.c", |
28985 | fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c", | |
28986 | line_asm_insn=[@{address="0x000107c0", | |
28987 | func-name="main",offset="4",inst="mov 2, %o0"@}, | |
a2c02241 NR |
28988 | @{address="0x000107c4",func-name="main",offset="8", |
28989 | inst="sethi %hi(0x11800), %o2"@}]@}] | |
594fe323 | 28990 | (gdb) |
a2c02241 NR |
28991 | @end smallexample |
28992 | ||
28993 | ||
28994 | @subheading The @code{-data-evaluate-expression} Command | |
28995 | @findex -data-evaluate-expression | |
922fbb7b AC |
28996 | |
28997 | @subsubheading Synopsis | |
28998 | ||
28999 | @smallexample | |
a2c02241 | 29000 | -data-evaluate-expression @var{expr} |
922fbb7b AC |
29001 | @end smallexample |
29002 | ||
a2c02241 NR |
29003 | Evaluate @var{expr} as an expression. The expression could contain an |
29004 | inferior function call. The function call will execute synchronously. | |
29005 | If the expression contains spaces, it must be enclosed in double quotes. | |
922fbb7b AC |
29006 | |
29007 | @subsubheading @value{GDBN} Command | |
29008 | ||
a2c02241 NR |
29009 | The corresponding @value{GDBN} commands are @samp{print}, @samp{output}, and |
29010 | @samp{call}. In @code{gdbtk} only, there's a corresponding | |
29011 | @samp{gdb_eval} command. | |
922fbb7b AC |
29012 | |
29013 | @subsubheading Example | |
29014 | ||
a2c02241 NR |
29015 | In the following example, the numbers that precede the commands are the |
29016 | @dfn{tokens} described in @ref{GDB/MI Command Syntax, ,@sc{gdb/mi} | |
29017 | Command Syntax}. Notice how @sc{gdb/mi} returns the same tokens in its | |
29018 | output. | |
29019 | ||
922fbb7b | 29020 | @smallexample |
a2c02241 NR |
29021 | 211-data-evaluate-expression A |
29022 | 211^done,value="1" | |
594fe323 | 29023 | (gdb) |
a2c02241 NR |
29024 | 311-data-evaluate-expression &A |
29025 | 311^done,value="0xefffeb7c" | |
594fe323 | 29026 | (gdb) |
a2c02241 NR |
29027 | 411-data-evaluate-expression A+3 |
29028 | 411^done,value="4" | |
594fe323 | 29029 | (gdb) |
a2c02241 NR |
29030 | 511-data-evaluate-expression "A + 3" |
29031 | 511^done,value="4" | |
594fe323 | 29032 | (gdb) |
a2c02241 | 29033 | @end smallexample |
922fbb7b AC |
29034 | |
29035 | ||
a2c02241 NR |
29036 | @subheading The @code{-data-list-changed-registers} Command |
29037 | @findex -data-list-changed-registers | |
922fbb7b AC |
29038 | |
29039 | @subsubheading Synopsis | |
29040 | ||
29041 | @smallexample | |
a2c02241 | 29042 | -data-list-changed-registers |
922fbb7b AC |
29043 | @end smallexample |
29044 | ||
a2c02241 | 29045 | Display a list of the registers that have changed. |
922fbb7b AC |
29046 | |
29047 | @subsubheading @value{GDBN} Command | |
29048 | ||
a2c02241 NR |
29049 | @value{GDBN} doesn't have a direct analog for this command; @code{gdbtk} |
29050 | has the corresponding command @samp{gdb_changed_register_list}. | |
922fbb7b AC |
29051 | |
29052 | @subsubheading Example | |
922fbb7b | 29053 | |
a2c02241 | 29054 | On a PPC MBX board: |
922fbb7b AC |
29055 | |
29056 | @smallexample | |
594fe323 | 29057 | (gdb) |
a2c02241 NR |
29058 | -exec-continue |
29059 | ^running | |
922fbb7b | 29060 | |
594fe323 | 29061 | (gdb) |
a47ec5fe AR |
29062 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",frame=@{ |
29063 | func="main",args=[],file="try.c",fullname="/home/foo/bar/try.c", | |
29064 | line="5"@} | |
594fe323 | 29065 | (gdb) |
a2c02241 NR |
29066 | -data-list-changed-registers |
29067 | ^done,changed-registers=["0","1","2","4","5","6","7","8","9", | |
29068 | "10","11","13","14","15","16","17","18","19","20","21","22","23", | |
29069 | "24","25","26","27","28","30","31","64","65","66","67","69"] | |
594fe323 | 29070 | (gdb) |
a2c02241 | 29071 | @end smallexample |
922fbb7b AC |
29072 | |
29073 | ||
a2c02241 NR |
29074 | @subheading The @code{-data-list-register-names} Command |
29075 | @findex -data-list-register-names | |
922fbb7b AC |
29076 | |
29077 | @subsubheading Synopsis | |
29078 | ||
29079 | @smallexample | |
a2c02241 | 29080 | -data-list-register-names [ ( @var{regno} )+ ] |
922fbb7b AC |
29081 | @end smallexample |
29082 | ||
a2c02241 NR |
29083 | Show a list of register names for the current target. If no arguments |
29084 | are given, it shows a list of the names of all the registers. If | |
29085 | integer numbers are given as arguments, it will print a list of the | |
29086 | names of the registers corresponding to the arguments. To ensure | |
29087 | consistency between a register name and its number, the output list may | |
29088 | include empty register names. | |
922fbb7b AC |
29089 | |
29090 | @subsubheading @value{GDBN} Command | |
29091 | ||
a2c02241 NR |
29092 | @value{GDBN} does not have a command which corresponds to |
29093 | @samp{-data-list-register-names}. In @code{gdbtk} there is a | |
29094 | corresponding command @samp{gdb_regnames}. | |
922fbb7b AC |
29095 | |
29096 | @subsubheading Example | |
922fbb7b | 29097 | |
a2c02241 NR |
29098 | For the PPC MBX board: |
29099 | @smallexample | |
594fe323 | 29100 | (gdb) |
a2c02241 NR |
29101 | -data-list-register-names |
29102 | ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7", | |
29103 | "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18", | |
29104 | "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29", | |
29105 | "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9", | |
29106 | "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20", | |
29107 | "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31", | |
29108 | "", "pc","ps","cr","lr","ctr","xer"] | |
594fe323 | 29109 | (gdb) |
a2c02241 NR |
29110 | -data-list-register-names 1 2 3 |
29111 | ^done,register-names=["r1","r2","r3"] | |
594fe323 | 29112 | (gdb) |
a2c02241 | 29113 | @end smallexample |
922fbb7b | 29114 | |
a2c02241 NR |
29115 | @subheading The @code{-data-list-register-values} Command |
29116 | @findex -data-list-register-values | |
922fbb7b AC |
29117 | |
29118 | @subsubheading Synopsis | |
29119 | ||
29120 | @smallexample | |
c898adb7 YQ |
29121 | -data-list-register-values |
29122 | [ @code{--skip-unavailable} ] @var{fmt} [ ( @var{regno} )*] | |
922fbb7b AC |
29123 | @end smallexample |
29124 | ||
697aa1b7 EZ |
29125 | Display the registers' contents. The format according to which the |
29126 | registers' contents are to be returned is given by @var{fmt}, followed | |
29127 | by an optional list of numbers specifying the registers to display. A | |
29128 | missing list of numbers indicates that the contents of all the | |
29129 | registers must be returned. The @code{--skip-unavailable} option | |
29130 | indicates that only the available registers are to be returned. | |
a2c02241 NR |
29131 | |
29132 | Allowed formats for @var{fmt} are: | |
29133 | ||
29134 | @table @code | |
29135 | @item x | |
29136 | Hexadecimal | |
29137 | @item o | |
29138 | Octal | |
29139 | @item t | |
29140 | Binary | |
29141 | @item d | |
29142 | Decimal | |
29143 | @item r | |
29144 | Raw | |
29145 | @item N | |
29146 | Natural | |
29147 | @end table | |
922fbb7b AC |
29148 | |
29149 | @subsubheading @value{GDBN} Command | |
29150 | ||
a2c02241 NR |
29151 | The corresponding @value{GDBN} commands are @samp{info reg}, @samp{info |
29152 | all-reg}, and (in @code{gdbtk}) @samp{gdb_fetch_registers}. | |
922fbb7b AC |
29153 | |
29154 | @subsubheading Example | |
922fbb7b | 29155 | |
a2c02241 NR |
29156 | For a PPC MBX board (note: line breaks are for readability only, they |
29157 | don't appear in the actual output): | |
29158 | ||
29159 | @smallexample | |
594fe323 | 29160 | (gdb) |
a2c02241 NR |
29161 | -data-list-register-values r 64 65 |
29162 | ^done,register-values=[@{number="64",value="0xfe00a300"@}, | |
29163 | @{number="65",value="0x00029002"@}] | |
594fe323 | 29164 | (gdb) |
a2c02241 NR |
29165 | -data-list-register-values x |
29166 | ^done,register-values=[@{number="0",value="0xfe0043c8"@}, | |
29167 | @{number="1",value="0x3fff88"@},@{number="2",value="0xfffffffe"@}, | |
29168 | @{number="3",value="0x0"@},@{number="4",value="0xa"@}, | |
29169 | @{number="5",value="0x3fff68"@},@{number="6",value="0x3fff58"@}, | |
29170 | @{number="7",value="0xfe011e98"@},@{number="8",value="0x2"@}, | |
29171 | @{number="9",value="0xfa202820"@},@{number="10",value="0xfa202808"@}, | |
29172 | @{number="11",value="0x1"@},@{number="12",value="0x0"@}, | |
29173 | @{number="13",value="0x4544"@},@{number="14",value="0xffdfffff"@}, | |
29174 | @{number="15",value="0xffffffff"@},@{number="16",value="0xfffffeff"@}, | |
29175 | @{number="17",value="0xefffffed"@},@{number="18",value="0xfffffffe"@}, | |
29176 | @{number="19",value="0xffffffff"@},@{number="20",value="0xffffffff"@}, | |
29177 | @{number="21",value="0xffffffff"@},@{number="22",value="0xfffffff7"@}, | |
29178 | @{number="23",value="0xffffffff"@},@{number="24",value="0xffffffff"@}, | |
29179 | @{number="25",value="0xffffffff"@},@{number="26",value="0xfffffffb"@}, | |
29180 | @{number="27",value="0xffffffff"@},@{number="28",value="0xf7bfffff"@}, | |
29181 | @{number="29",value="0x0"@},@{number="30",value="0xfe010000"@}, | |
29182 | @{number="31",value="0x0"@},@{number="32",value="0x0"@}, | |
29183 | @{number="33",value="0x0"@},@{number="34",value="0x0"@}, | |
29184 | @{number="35",value="0x0"@},@{number="36",value="0x0"@}, | |
29185 | @{number="37",value="0x0"@},@{number="38",value="0x0"@}, | |
29186 | @{number="39",value="0x0"@},@{number="40",value="0x0"@}, | |
29187 | @{number="41",value="0x0"@},@{number="42",value="0x0"@}, | |
29188 | @{number="43",value="0x0"@},@{number="44",value="0x0"@}, | |
29189 | @{number="45",value="0x0"@},@{number="46",value="0x0"@}, | |
29190 | @{number="47",value="0x0"@},@{number="48",value="0x0"@}, | |
29191 | @{number="49",value="0x0"@},@{number="50",value="0x0"@}, | |
29192 | @{number="51",value="0x0"@},@{number="52",value="0x0"@}, | |
29193 | @{number="53",value="0x0"@},@{number="54",value="0x0"@}, | |
29194 | @{number="55",value="0x0"@},@{number="56",value="0x0"@}, | |
29195 | @{number="57",value="0x0"@},@{number="58",value="0x0"@}, | |
29196 | @{number="59",value="0x0"@},@{number="60",value="0x0"@}, | |
29197 | @{number="61",value="0x0"@},@{number="62",value="0x0"@}, | |
29198 | @{number="63",value="0x0"@},@{number="64",value="0xfe00a300"@}, | |
29199 | @{number="65",value="0x29002"@},@{number="66",value="0x202f04b5"@}, | |
29200 | @{number="67",value="0xfe0043b0"@},@{number="68",value="0xfe00b3e4"@}, | |
29201 | @{number="69",value="0x20002b03"@}] | |
594fe323 | 29202 | (gdb) |
a2c02241 | 29203 | @end smallexample |
922fbb7b | 29204 | |
a2c02241 NR |
29205 | |
29206 | @subheading The @code{-data-read-memory} Command | |
29207 | @findex -data-read-memory | |
922fbb7b | 29208 | |
8dedea02 VP |
29209 | This command is deprecated, use @code{-data-read-memory-bytes} instead. |
29210 | ||
922fbb7b AC |
29211 | @subsubheading Synopsis |
29212 | ||
29213 | @smallexample | |
a2c02241 NR |
29214 | -data-read-memory [ -o @var{byte-offset} ] |
29215 | @var{address} @var{word-format} @var{word-size} | |
29216 | @var{nr-rows} @var{nr-cols} [ @var{aschar} ] | |
922fbb7b AC |
29217 | @end smallexample |
29218 | ||
a2c02241 NR |
29219 | @noindent |
29220 | where: | |
922fbb7b | 29221 | |
a2c02241 NR |
29222 | @table @samp |
29223 | @item @var{address} | |
29224 | An expression specifying the address of the first memory word to be | |
29225 | read. Complex expressions containing embedded white space should be | |
29226 | quoted using the C convention. | |
922fbb7b | 29227 | |
a2c02241 NR |
29228 | @item @var{word-format} |
29229 | The format to be used to print the memory words. The notation is the | |
29230 | same as for @value{GDBN}'s @code{print} command (@pxref{Output Formats, | |
79a6e687 | 29231 | ,Output Formats}). |
922fbb7b | 29232 | |
a2c02241 NR |
29233 | @item @var{word-size} |
29234 | The size of each memory word in bytes. | |
922fbb7b | 29235 | |
a2c02241 NR |
29236 | @item @var{nr-rows} |
29237 | The number of rows in the output table. | |
922fbb7b | 29238 | |
a2c02241 NR |
29239 | @item @var{nr-cols} |
29240 | The number of columns in the output table. | |
922fbb7b | 29241 | |
a2c02241 NR |
29242 | @item @var{aschar} |
29243 | If present, indicates that each row should include an @sc{ascii} dump. The | |
29244 | value of @var{aschar} is used as a padding character when a byte is not a | |
29245 | member of the printable @sc{ascii} character set (printable @sc{ascii} | |
29246 | characters are those whose code is between 32 and 126, inclusively). | |
922fbb7b | 29247 | |
a2c02241 NR |
29248 | @item @var{byte-offset} |
29249 | An offset to add to the @var{address} before fetching memory. | |
29250 | @end table | |
922fbb7b | 29251 | |
a2c02241 NR |
29252 | This command displays memory contents as a table of @var{nr-rows} by |
29253 | @var{nr-cols} words, each word being @var{word-size} bytes. In total, | |
29254 | @code{@var{nr-rows} * @var{nr-cols} * @var{word-size}} bytes are read | |
29255 | (returned as @samp{total-bytes}). Should less than the requested number | |
29256 | of bytes be returned by the target, the missing words are identified | |
29257 | using @samp{N/A}. The number of bytes read from the target is returned | |
29258 | in @samp{nr-bytes} and the starting address used to read memory in | |
29259 | @samp{addr}. | |
29260 | ||
29261 | The address of the next/previous row or page is available in | |
29262 | @samp{next-row} and @samp{prev-row}, @samp{next-page} and | |
29263 | @samp{prev-page}. | |
922fbb7b AC |
29264 | |
29265 | @subsubheading @value{GDBN} Command | |
29266 | ||
a2c02241 NR |
29267 | The corresponding @value{GDBN} command is @samp{x}. @code{gdbtk} has |
29268 | @samp{gdb_get_mem} memory read command. | |
922fbb7b AC |
29269 | |
29270 | @subsubheading Example | |
32e7087d | 29271 | |
a2c02241 NR |
29272 | Read six bytes of memory starting at @code{bytes+6} but then offset by |
29273 | @code{-6} bytes. Format as three rows of two columns. One byte per | |
29274 | word. Display each word in hex. | |
32e7087d JB |
29275 | |
29276 | @smallexample | |
594fe323 | 29277 | (gdb) |
a2c02241 NR |
29278 | 9-data-read-memory -o -6 -- bytes+6 x 1 3 2 |
29279 | 9^done,addr="0x00001390",nr-bytes="6",total-bytes="6", | |
29280 | next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396", | |
29281 | prev-page="0x0000138a",memory=[ | |
29282 | @{addr="0x00001390",data=["0x00","0x01"]@}, | |
29283 | @{addr="0x00001392",data=["0x02","0x03"]@}, | |
29284 | @{addr="0x00001394",data=["0x04","0x05"]@}] | |
594fe323 | 29285 | (gdb) |
32e7087d JB |
29286 | @end smallexample |
29287 | ||
a2c02241 NR |
29288 | Read two bytes of memory starting at address @code{shorts + 64} and |
29289 | display as a single word formatted in decimal. | |
32e7087d | 29290 | |
32e7087d | 29291 | @smallexample |
594fe323 | 29292 | (gdb) |
a2c02241 NR |
29293 | 5-data-read-memory shorts+64 d 2 1 1 |
29294 | 5^done,addr="0x00001510",nr-bytes="2",total-bytes="2", | |
29295 | next-row="0x00001512",prev-row="0x0000150e", | |
29296 | next-page="0x00001512",prev-page="0x0000150e",memory=[ | |
29297 | @{addr="0x00001510",data=["128"]@}] | |
594fe323 | 29298 | (gdb) |
32e7087d JB |
29299 | @end smallexample |
29300 | ||
a2c02241 NR |
29301 | Read thirty two bytes of memory starting at @code{bytes+16} and format |
29302 | as eight rows of four columns. Include a string encoding with @samp{x} | |
29303 | used as the non-printable character. | |
922fbb7b AC |
29304 | |
29305 | @smallexample | |
594fe323 | 29306 | (gdb) |
a2c02241 NR |
29307 | 4-data-read-memory bytes+16 x 1 8 4 x |
29308 | 4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32", | |
29309 | next-row="0x000013c0",prev-row="0x0000139c", | |
29310 | next-page="0x000013c0",prev-page="0x00001380",memory=[ | |
29311 | @{addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"@}, | |
29312 | @{addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"@}, | |
29313 | @{addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"@}, | |
29314 | @{addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"@}, | |
29315 | @{addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"@}, | |
29316 | @{addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"@}, | |
29317 | @{addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"@}, | |
29318 | @{addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"@}] | |
594fe323 | 29319 | (gdb) |
922fbb7b AC |
29320 | @end smallexample |
29321 | ||
8dedea02 VP |
29322 | @subheading The @code{-data-read-memory-bytes} Command |
29323 | @findex -data-read-memory-bytes | |
29324 | ||
29325 | @subsubheading Synopsis | |
29326 | ||
29327 | @smallexample | |
29328 | -data-read-memory-bytes [ -o @var{byte-offset} ] | |
29329 | @var{address} @var{count} | |
29330 | @end smallexample | |
29331 | ||
29332 | @noindent | |
29333 | where: | |
29334 | ||
29335 | @table @samp | |
29336 | @item @var{address} | |
29337 | An expression specifying the address of the first memory word to be | |
29338 | read. Complex expressions containing embedded white space should be | |
29339 | quoted using the C convention. | |
29340 | ||
29341 | @item @var{count} | |
29342 | The number of bytes to read. This should be an integer literal. | |
29343 | ||
29344 | @item @var{byte-offset} | |
29345 | The offsets in bytes relative to @var{address} at which to start | |
29346 | reading. This should be an integer literal. This option is provided | |
29347 | so that a frontend is not required to first evaluate address and then | |
29348 | perform address arithmetics itself. | |
29349 | ||
29350 | @end table | |
29351 | ||
29352 | This command attempts to read all accessible memory regions in the | |
29353 | specified range. First, all regions marked as unreadable in the memory | |
29354 | map (if one is defined) will be skipped. @xref{Memory Region | |
29355 | Attributes}. Second, @value{GDBN} will attempt to read the remaining | |
29356 | regions. For each one, if reading full region results in an errors, | |
29357 | @value{GDBN} will try to read a subset of the region. | |
29358 | ||
29359 | In general, every single byte in the region may be readable or not, | |
29360 | and the only way to read every readable byte is to try a read at | |
29361 | every address, which is not practical. Therefore, @value{GDBN} will | |
29362 | attempt to read all accessible bytes at either beginning or the end | |
29363 | of the region, using a binary division scheme. This heuristic works | |
29364 | well for reading accross a memory map boundary. Note that if a region | |
29365 | has a readable range that is neither at the beginning or the end, | |
29366 | @value{GDBN} will not read it. | |
29367 | ||
29368 | The result record (@pxref{GDB/MI Result Records}) that is output of | |
29369 | the command includes a field named @samp{memory} whose content is a | |
29370 | list of tuples. Each tuple represent a successfully read memory block | |
29371 | and has the following fields: | |
29372 | ||
29373 | @table @code | |
29374 | @item begin | |
29375 | The start address of the memory block, as hexadecimal literal. | |
29376 | ||
29377 | @item end | |
29378 | The end address of the memory block, as hexadecimal literal. | |
29379 | ||
29380 | @item offset | |
29381 | The offset of the memory block, as hexadecimal literal, relative to | |
29382 | the start address passed to @code{-data-read-memory-bytes}. | |
29383 | ||
29384 | @item contents | |
29385 | The contents of the memory block, in hex. | |
29386 | ||
29387 | @end table | |
29388 | ||
29389 | ||
29390 | ||
29391 | @subsubheading @value{GDBN} Command | |
29392 | ||
29393 | The corresponding @value{GDBN} command is @samp{x}. | |
29394 | ||
29395 | @subsubheading Example | |
29396 | ||
29397 | @smallexample | |
29398 | (gdb) | |
29399 | -data-read-memory-bytes &a 10 | |
29400 | ^done,memory=[@{begin="0xbffff154",offset="0x00000000", | |
29401 | end="0xbffff15e", | |
29402 | contents="01000000020000000300"@}] | |
29403 | (gdb) | |
29404 | @end smallexample | |
29405 | ||
29406 | ||
29407 | @subheading The @code{-data-write-memory-bytes} Command | |
29408 | @findex -data-write-memory-bytes | |
29409 | ||
29410 | @subsubheading Synopsis | |
29411 | ||
29412 | @smallexample | |
29413 | -data-write-memory-bytes @var{address} @var{contents} | |
62747a60 | 29414 | -data-write-memory-bytes @var{address} @var{contents} @r{[}@var{count}@r{]} |
8dedea02 VP |
29415 | @end smallexample |
29416 | ||
29417 | @noindent | |
29418 | where: | |
29419 | ||
29420 | @table @samp | |
29421 | @item @var{address} | |
29422 | An expression specifying the address of the first memory word to be | |
29423 | read. Complex expressions containing embedded white space should be | |
29424 | quoted using the C convention. | |
29425 | ||
29426 | @item @var{contents} | |
29427 | The hex-encoded bytes to write. | |
29428 | ||
62747a60 TT |
29429 | @item @var{count} |
29430 | Optional argument indicating the number of bytes to be written. If @var{count} | |
29431 | is greater than @var{contents}' length, @value{GDBN} will repeatedly | |
29432 | write @var{contents} until it fills @var{count} bytes. | |
29433 | ||
8dedea02 VP |
29434 | @end table |
29435 | ||
29436 | @subsubheading @value{GDBN} Command | |
29437 | ||
29438 | There's no corresponding @value{GDBN} command. | |
29439 | ||
29440 | @subsubheading Example | |
29441 | ||
29442 | @smallexample | |
29443 | (gdb) | |
29444 | -data-write-memory-bytes &a "aabbccdd" | |
29445 | ^done | |
29446 | (gdb) | |
29447 | @end smallexample | |
29448 | ||
62747a60 TT |
29449 | @smallexample |
29450 | (gdb) | |
29451 | -data-write-memory-bytes &a "aabbccdd" 16e | |
29452 | ^done | |
29453 | (gdb) | |
29454 | @end smallexample | |
8dedea02 | 29455 | |
a2c02241 NR |
29456 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
29457 | @node GDB/MI Tracepoint Commands | |
29458 | @section @sc{gdb/mi} Tracepoint Commands | |
922fbb7b | 29459 | |
18148017 VP |
29460 | The commands defined in this section implement MI support for |
29461 | tracepoints. For detailed introduction, see @ref{Tracepoints}. | |
29462 | ||
29463 | @subheading The @code{-trace-find} Command | |
29464 | @findex -trace-find | |
29465 | ||
29466 | @subsubheading Synopsis | |
29467 | ||
29468 | @smallexample | |
29469 | -trace-find @var{mode} [@var{parameters}@dots{}] | |
29470 | @end smallexample | |
29471 | ||
29472 | Find a trace frame using criteria defined by @var{mode} and | |
29473 | @var{parameters}. The following table lists permissible | |
29474 | modes and their parameters. For details of operation, see @ref{tfind}. | |
29475 | ||
29476 | @table @samp | |
29477 | ||
29478 | @item none | |
29479 | No parameters are required. Stops examining trace frames. | |
29480 | ||
29481 | @item frame-number | |
29482 | An integer is required as parameter. Selects tracepoint frame with | |
29483 | that index. | |
29484 | ||
29485 | @item tracepoint-number | |
29486 | An integer is required as parameter. Finds next | |
29487 | trace frame that corresponds to tracepoint with the specified number. | |
29488 | ||
29489 | @item pc | |
29490 | An address is required as parameter. Finds | |
29491 | next trace frame that corresponds to any tracepoint at the specified | |
29492 | address. | |
29493 | ||
29494 | @item pc-inside-range | |
29495 | Two addresses are required as parameters. Finds next trace | |
29496 | frame that corresponds to a tracepoint at an address inside the | |
29497 | specified range. Both bounds are considered to be inside the range. | |
29498 | ||
29499 | @item pc-outside-range | |
29500 | Two addresses are required as parameters. Finds | |
29501 | next trace frame that corresponds to a tracepoint at an address outside | |
29502 | the specified range. Both bounds are considered to be inside the range. | |
29503 | ||
29504 | @item line | |
29505 | Line specification is required as parameter. @xref{Specify Location}. | |
29506 | Finds next trace frame that corresponds to a tracepoint at | |
29507 | the specified location. | |
29508 | ||
29509 | @end table | |
29510 | ||
29511 | If @samp{none} was passed as @var{mode}, the response does not | |
29512 | have fields. Otherwise, the response may have the following fields: | |
29513 | ||
29514 | @table @samp | |
29515 | @item found | |
29516 | This field has either @samp{0} or @samp{1} as the value, depending | |
29517 | on whether a matching tracepoint was found. | |
29518 | ||
29519 | @item traceframe | |
29520 | The index of the found traceframe. This field is present iff | |
29521 | the @samp{found} field has value of @samp{1}. | |
29522 | ||
29523 | @item tracepoint | |
29524 | The index of the found tracepoint. This field is present iff | |
29525 | the @samp{found} field has value of @samp{1}. | |
29526 | ||
29527 | @item frame | |
29528 | The information about the frame corresponding to the found trace | |
29529 | frame. This field is present only if a trace frame was found. | |
cd64ee31 | 29530 | @xref{GDB/MI Frame Information}, for description of this field. |
18148017 VP |
29531 | |
29532 | @end table | |
29533 | ||
7d13fe92 SS |
29534 | @subsubheading @value{GDBN} Command |
29535 | ||
29536 | The corresponding @value{GDBN} command is @samp{tfind}. | |
29537 | ||
18148017 VP |
29538 | @subheading -trace-define-variable |
29539 | @findex -trace-define-variable | |
29540 | ||
29541 | @subsubheading Synopsis | |
29542 | ||
29543 | @smallexample | |
29544 | -trace-define-variable @var{name} [ @var{value} ] | |
29545 | @end smallexample | |
29546 | ||
29547 | Create trace variable @var{name} if it does not exist. If | |
29548 | @var{value} is specified, sets the initial value of the specified | |
29549 | trace variable to that value. Note that the @var{name} should start | |
29550 | with the @samp{$} character. | |
29551 | ||
7d13fe92 SS |
29552 | @subsubheading @value{GDBN} Command |
29553 | ||
29554 | The corresponding @value{GDBN} command is @samp{tvariable}. | |
29555 | ||
dc673c81 YQ |
29556 | @subheading The @code{-trace-frame-collected} Command |
29557 | @findex -trace-frame-collected | |
29558 | ||
29559 | @subsubheading Synopsis | |
29560 | ||
29561 | @smallexample | |
29562 | -trace-frame-collected | |
29563 | [--var-print-values @var{var_pval}] | |
29564 | [--comp-print-values @var{comp_pval}] | |
29565 | [--registers-format @var{regformat}] | |
29566 | [--memory-contents] | |
29567 | @end smallexample | |
29568 | ||
29569 | This command returns the set of collected objects, register names, | |
29570 | trace state variable names, memory ranges and computed expressions | |
29571 | that have been collected at a particular trace frame. The optional | |
29572 | parameters to the command affect the output format in different ways. | |
29573 | See the output description table below for more details. | |
29574 | ||
29575 | The reported names can be used in the normal manner to create | |
29576 | varobjs and inspect the objects themselves. The items returned by | |
29577 | this command are categorized so that it is clear which is a variable, | |
29578 | which is a register, which is a trace state variable, which is a | |
29579 | memory range and which is a computed expression. | |
29580 | ||
29581 | For instance, if the actions were | |
29582 | @smallexample | |
29583 | collect myVar, myArray[myIndex], myObj.field, myPtr->field, myCount + 2 | |
29584 | collect *(int*)0xaf02bef0@@40 | |
29585 | @end smallexample | |
29586 | ||
29587 | @noindent | |
29588 | the object collected in its entirety would be @code{myVar}. The | |
29589 | object @code{myArray} would be partially collected, because only the | |
29590 | element at index @code{myIndex} would be collected. The remaining | |
29591 | objects would be computed expressions. | |
29592 | ||
29593 | An example output would be: | |
29594 | ||
29595 | @smallexample | |
29596 | (gdb) | |
29597 | -trace-frame-collected | |
29598 | ^done, | |
29599 | explicit-variables=[@{name="myVar",value="1"@}], | |
29600 | computed-expressions=[@{name="myArray[myIndex]",value="0"@}, | |
29601 | @{name="myObj.field",value="0"@}, | |
29602 | @{name="myPtr->field",value="1"@}, | |
29603 | @{name="myCount + 2",value="3"@}, | |
29604 | @{name="$tvar1 + 1",value="43970027"@}], | |
29605 | registers=[@{number="0",value="0x7fe2c6e79ec8"@}, | |
29606 | @{number="1",value="0x0"@}, | |
29607 | @{number="2",value="0x4"@}, | |
29608 | ... | |
29609 | @{number="125",value="0x0"@}], | |
29610 | tvars=[@{name="$tvar1",current="43970026"@}], | |
29611 | memory=[@{address="0x0000000000602264",length="4"@}, | |
29612 | @{address="0x0000000000615bc0",length="4"@}] | |
29613 | (gdb) | |
29614 | @end smallexample | |
29615 | ||
29616 | Where: | |
29617 | ||
29618 | @table @code | |
29619 | @item explicit-variables | |
29620 | The set of objects that have been collected in their entirety (as | |
29621 | opposed to collecting just a few elements of an array or a few struct | |
29622 | members). For each object, its name and value are printed. | |
29623 | The @code{--var-print-values} option affects how or whether the value | |
29624 | field is output. If @var{var_pval} is 0, then print only the names; | |
29625 | if it is 1, print also their values; and if it is 2, print the name, | |
29626 | type and value for simple data types, and the name and type for | |
29627 | arrays, structures and unions. | |
29628 | ||
29629 | @item computed-expressions | |
29630 | The set of computed expressions that have been collected at the | |
29631 | current trace frame. The @code{--comp-print-values} option affects | |
29632 | this set like the @code{--var-print-values} option affects the | |
29633 | @code{explicit-variables} set. See above. | |
29634 | ||
29635 | @item registers | |
29636 | The registers that have been collected at the current trace frame. | |
29637 | For each register collected, the name and current value are returned. | |
29638 | The value is formatted according to the @code{--registers-format} | |
29639 | option. See the @command{-data-list-register-values} command for a | |
29640 | list of the allowed formats. The default is @samp{x}. | |
29641 | ||
29642 | @item tvars | |
29643 | The trace state variables that have been collected at the current | |
29644 | trace frame. For each trace state variable collected, the name and | |
29645 | current value are returned. | |
29646 | ||
29647 | @item memory | |
29648 | The set of memory ranges that have been collected at the current trace | |
29649 | frame. Its content is a list of tuples. Each tuple represents a | |
29650 | collected memory range and has the following fields: | |
29651 | ||
29652 | @table @code | |
29653 | @item address | |
29654 | The start address of the memory range, as hexadecimal literal. | |
29655 | ||
29656 | @item length | |
29657 | The length of the memory range, as decimal literal. | |
29658 | ||
29659 | @item contents | |
29660 | The contents of the memory block, in hex. This field is only present | |
29661 | if the @code{--memory-contents} option is specified. | |
29662 | ||
29663 | @end table | |
29664 | ||
29665 | @end table | |
29666 | ||
29667 | @subsubheading @value{GDBN} Command | |
29668 | ||
29669 | There is no corresponding @value{GDBN} command. | |
29670 | ||
29671 | @subsubheading Example | |
29672 | ||
18148017 VP |
29673 | @subheading -trace-list-variables |
29674 | @findex -trace-list-variables | |
922fbb7b | 29675 | |
18148017 | 29676 | @subsubheading Synopsis |
922fbb7b | 29677 | |
18148017 VP |
29678 | @smallexample |
29679 | -trace-list-variables | |
29680 | @end smallexample | |
922fbb7b | 29681 | |
18148017 VP |
29682 | Return a table of all defined trace variables. Each element of the |
29683 | table has the following fields: | |
922fbb7b | 29684 | |
18148017 VP |
29685 | @table @samp |
29686 | @item name | |
29687 | The name of the trace variable. This field is always present. | |
922fbb7b | 29688 | |
18148017 VP |
29689 | @item initial |
29690 | The initial value. This is a 64-bit signed integer. This | |
29691 | field is always present. | |
922fbb7b | 29692 | |
18148017 VP |
29693 | @item current |
29694 | The value the trace variable has at the moment. This is a 64-bit | |
29695 | signed integer. This field is absent iff current value is | |
29696 | not defined, for example if the trace was never run, or is | |
29697 | presently running. | |
922fbb7b | 29698 | |
18148017 | 29699 | @end table |
922fbb7b | 29700 | |
7d13fe92 SS |
29701 | @subsubheading @value{GDBN} Command |
29702 | ||
29703 | The corresponding @value{GDBN} command is @samp{tvariables}. | |
29704 | ||
18148017 | 29705 | @subsubheading Example |
922fbb7b | 29706 | |
18148017 VP |
29707 | @smallexample |
29708 | (gdb) | |
29709 | -trace-list-variables | |
29710 | ^done,trace-variables=@{nr_rows="1",nr_cols="3", | |
29711 | hdr=[@{width="15",alignment="-1",col_name="name",colhdr="Name"@}, | |
29712 | @{width="11",alignment="-1",col_name="initial",colhdr="Initial"@}, | |
29713 | @{width="11",alignment="-1",col_name="current",colhdr="Current"@}], | |
29714 | body=[variable=@{name="$trace_timestamp",initial="0"@} | |
29715 | variable=@{name="$foo",initial="10",current="15"@}]@} | |
29716 | (gdb) | |
29717 | @end smallexample | |
922fbb7b | 29718 | |
18148017 VP |
29719 | @subheading -trace-save |
29720 | @findex -trace-save | |
922fbb7b | 29721 | |
18148017 VP |
29722 | @subsubheading Synopsis |
29723 | ||
29724 | @smallexample | |
29725 | -trace-save [-r ] @var{filename} | |
29726 | @end smallexample | |
29727 | ||
29728 | Saves the collected trace data to @var{filename}. Without the | |
29729 | @samp{-r} option, the data is downloaded from the target and saved | |
29730 | in a local file. With the @samp{-r} option the target is asked | |
29731 | to perform the save. | |
29732 | ||
7d13fe92 SS |
29733 | @subsubheading @value{GDBN} Command |
29734 | ||
29735 | The corresponding @value{GDBN} command is @samp{tsave}. | |
29736 | ||
18148017 VP |
29737 | |
29738 | @subheading -trace-start | |
29739 | @findex -trace-start | |
29740 | ||
29741 | @subsubheading Synopsis | |
29742 | ||
29743 | @smallexample | |
29744 | -trace-start | |
29745 | @end smallexample | |
922fbb7b | 29746 | |
18148017 VP |
29747 | Starts a tracing experiments. The result of this command does not |
29748 | have any fields. | |
922fbb7b | 29749 | |
7d13fe92 SS |
29750 | @subsubheading @value{GDBN} Command |
29751 | ||
29752 | The corresponding @value{GDBN} command is @samp{tstart}. | |
29753 | ||
18148017 VP |
29754 | @subheading -trace-status |
29755 | @findex -trace-status | |
922fbb7b | 29756 | |
18148017 VP |
29757 | @subsubheading Synopsis |
29758 | ||
29759 | @smallexample | |
29760 | -trace-status | |
29761 | @end smallexample | |
29762 | ||
a97153c7 | 29763 | Obtains the status of a tracing experiment. The result may include |
18148017 VP |
29764 | the following fields: |
29765 | ||
29766 | @table @samp | |
29767 | ||
29768 | @item supported | |
29769 | May have a value of either @samp{0}, when no tracing operations are | |
29770 | supported, @samp{1}, when all tracing operations are supported, or | |
29771 | @samp{file} when examining trace file. In the latter case, examining | |
29772 | of trace frame is possible but new tracing experiement cannot be | |
29773 | started. This field is always present. | |
29774 | ||
29775 | @item running | |
29776 | May have a value of either @samp{0} or @samp{1} depending on whether | |
29777 | tracing experiement is in progress on target. This field is present | |
29778 | if @samp{supported} field is not @samp{0}. | |
29779 | ||
29780 | @item stop-reason | |
29781 | Report the reason why the tracing was stopped last time. This field | |
29782 | may be absent iff tracing was never stopped on target yet. The | |
29783 | value of @samp{request} means the tracing was stopped as result of | |
29784 | the @code{-trace-stop} command. The value of @samp{overflow} means | |
29785 | the tracing buffer is full. The value of @samp{disconnection} means | |
29786 | tracing was automatically stopped when @value{GDBN} has disconnected. | |
29787 | The value of @samp{passcount} means tracing was stopped when a | |
29788 | tracepoint was passed a maximal number of times for that tracepoint. | |
29789 | This field is present if @samp{supported} field is not @samp{0}. | |
29790 | ||
29791 | @item stopping-tracepoint | |
29792 | The number of tracepoint whose passcount as exceeded. This field is | |
29793 | present iff the @samp{stop-reason} field has the value of | |
29794 | @samp{passcount}. | |
29795 | ||
29796 | @item frames | |
87290684 SS |
29797 | @itemx frames-created |
29798 | The @samp{frames} field is a count of the total number of trace frames | |
29799 | in the trace buffer, while @samp{frames-created} is the total created | |
29800 | during the run, including ones that were discarded, such as when a | |
29801 | circular trace buffer filled up. Both fields are optional. | |
18148017 VP |
29802 | |
29803 | @item buffer-size | |
29804 | @itemx buffer-free | |
29805 | These fields tell the current size of the tracing buffer and the | |
87290684 | 29806 | remaining space. These fields are optional. |
18148017 | 29807 | |
a97153c7 PA |
29808 | @item circular |
29809 | The value of the circular trace buffer flag. @code{1} means that the | |
29810 | trace buffer is circular and old trace frames will be discarded if | |
29811 | necessary to make room, @code{0} means that the trace buffer is linear | |
29812 | and may fill up. | |
29813 | ||
29814 | @item disconnected | |
29815 | The value of the disconnected tracing flag. @code{1} means that | |
29816 | tracing will continue after @value{GDBN} disconnects, @code{0} means | |
29817 | that the trace run will stop. | |
29818 | ||
f5911ea1 HAQ |
29819 | @item trace-file |
29820 | The filename of the trace file being examined. This field is | |
29821 | optional, and only present when examining a trace file. | |
29822 | ||
18148017 VP |
29823 | @end table |
29824 | ||
7d13fe92 SS |
29825 | @subsubheading @value{GDBN} Command |
29826 | ||
29827 | The corresponding @value{GDBN} command is @samp{tstatus}. | |
29828 | ||
18148017 VP |
29829 | @subheading -trace-stop |
29830 | @findex -trace-stop | |
29831 | ||
29832 | @subsubheading Synopsis | |
29833 | ||
29834 | @smallexample | |
29835 | -trace-stop | |
29836 | @end smallexample | |
922fbb7b | 29837 | |
18148017 VP |
29838 | Stops a tracing experiment. The result of this command has the same |
29839 | fields as @code{-trace-status}, except that the @samp{supported} and | |
29840 | @samp{running} fields are not output. | |
922fbb7b | 29841 | |
7d13fe92 SS |
29842 | @subsubheading @value{GDBN} Command |
29843 | ||
29844 | The corresponding @value{GDBN} command is @samp{tstop}. | |
29845 | ||
922fbb7b | 29846 | |
a2c02241 NR |
29847 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
29848 | @node GDB/MI Symbol Query | |
29849 | @section @sc{gdb/mi} Symbol Query Commands | |
922fbb7b AC |
29850 | |
29851 | ||
9901a55b | 29852 | @ignore |
a2c02241 NR |
29853 | @subheading The @code{-symbol-info-address} Command |
29854 | @findex -symbol-info-address | |
922fbb7b AC |
29855 | |
29856 | @subsubheading Synopsis | |
29857 | ||
29858 | @smallexample | |
a2c02241 | 29859 | -symbol-info-address @var{symbol} |
922fbb7b AC |
29860 | @end smallexample |
29861 | ||
a2c02241 | 29862 | Describe where @var{symbol} is stored. |
922fbb7b AC |
29863 | |
29864 | @subsubheading @value{GDBN} Command | |
29865 | ||
a2c02241 | 29866 | The corresponding @value{GDBN} command is @samp{info address}. |
922fbb7b AC |
29867 | |
29868 | @subsubheading Example | |
29869 | N.A. | |
29870 | ||
29871 | ||
a2c02241 NR |
29872 | @subheading The @code{-symbol-info-file} Command |
29873 | @findex -symbol-info-file | |
922fbb7b AC |
29874 | |
29875 | @subsubheading Synopsis | |
29876 | ||
29877 | @smallexample | |
a2c02241 | 29878 | -symbol-info-file |
922fbb7b AC |
29879 | @end smallexample |
29880 | ||
a2c02241 | 29881 | Show the file for the symbol. |
922fbb7b | 29882 | |
a2c02241 | 29883 | @subsubheading @value{GDBN} Command |
922fbb7b | 29884 | |
a2c02241 NR |
29885 | There's no equivalent @value{GDBN} command. @code{gdbtk} has |
29886 | @samp{gdb_find_file}. | |
922fbb7b AC |
29887 | |
29888 | @subsubheading Example | |
29889 | N.A. | |
29890 | ||
29891 | ||
a2c02241 NR |
29892 | @subheading The @code{-symbol-info-function} Command |
29893 | @findex -symbol-info-function | |
922fbb7b AC |
29894 | |
29895 | @subsubheading Synopsis | |
29896 | ||
29897 | @smallexample | |
a2c02241 | 29898 | -symbol-info-function |
922fbb7b AC |
29899 | @end smallexample |
29900 | ||
a2c02241 | 29901 | Show which function the symbol lives in. |
922fbb7b AC |
29902 | |
29903 | @subsubheading @value{GDBN} Command | |
29904 | ||
a2c02241 | 29905 | @samp{gdb_get_function} in @code{gdbtk}. |
922fbb7b AC |
29906 | |
29907 | @subsubheading Example | |
29908 | N.A. | |
29909 | ||
29910 | ||
a2c02241 NR |
29911 | @subheading The @code{-symbol-info-line} Command |
29912 | @findex -symbol-info-line | |
922fbb7b AC |
29913 | |
29914 | @subsubheading Synopsis | |
29915 | ||
29916 | @smallexample | |
a2c02241 | 29917 | -symbol-info-line |
922fbb7b AC |
29918 | @end smallexample |
29919 | ||
a2c02241 | 29920 | Show the core addresses of the code for a source line. |
922fbb7b | 29921 | |
a2c02241 | 29922 | @subsubheading @value{GDBN} Command |
922fbb7b | 29923 | |
a2c02241 NR |
29924 | The corresponding @value{GDBN} command is @samp{info line}. |
29925 | @code{gdbtk} has the @samp{gdb_get_line} and @samp{gdb_get_file} commands. | |
922fbb7b AC |
29926 | |
29927 | @subsubheading Example | |
a2c02241 | 29928 | N.A. |
922fbb7b AC |
29929 | |
29930 | ||
a2c02241 NR |
29931 | @subheading The @code{-symbol-info-symbol} Command |
29932 | @findex -symbol-info-symbol | |
07f31aa6 DJ |
29933 | |
29934 | @subsubheading Synopsis | |
29935 | ||
a2c02241 NR |
29936 | @smallexample |
29937 | -symbol-info-symbol @var{addr} | |
29938 | @end smallexample | |
07f31aa6 | 29939 | |
a2c02241 | 29940 | Describe what symbol is at location @var{addr}. |
07f31aa6 | 29941 | |
a2c02241 | 29942 | @subsubheading @value{GDBN} Command |
07f31aa6 | 29943 | |
a2c02241 | 29944 | The corresponding @value{GDBN} command is @samp{info symbol}. |
07f31aa6 DJ |
29945 | |
29946 | @subsubheading Example | |
a2c02241 | 29947 | N.A. |
07f31aa6 DJ |
29948 | |
29949 | ||
a2c02241 NR |
29950 | @subheading The @code{-symbol-list-functions} Command |
29951 | @findex -symbol-list-functions | |
922fbb7b AC |
29952 | |
29953 | @subsubheading Synopsis | |
29954 | ||
29955 | @smallexample | |
a2c02241 | 29956 | -symbol-list-functions |
922fbb7b AC |
29957 | @end smallexample |
29958 | ||
a2c02241 | 29959 | List the functions in the executable. |
922fbb7b AC |
29960 | |
29961 | @subsubheading @value{GDBN} Command | |
29962 | ||
a2c02241 NR |
29963 | @samp{info functions} in @value{GDBN}, @samp{gdb_listfunc} and |
29964 | @samp{gdb_search} in @code{gdbtk}. | |
922fbb7b AC |
29965 | |
29966 | @subsubheading Example | |
a2c02241 | 29967 | N.A. |
9901a55b | 29968 | @end ignore |
922fbb7b AC |
29969 | |
29970 | ||
a2c02241 NR |
29971 | @subheading The @code{-symbol-list-lines} Command |
29972 | @findex -symbol-list-lines | |
922fbb7b AC |
29973 | |
29974 | @subsubheading Synopsis | |
29975 | ||
29976 | @smallexample | |
a2c02241 | 29977 | -symbol-list-lines @var{filename} |
922fbb7b AC |
29978 | @end smallexample |
29979 | ||
a2c02241 NR |
29980 | Print the list of lines that contain code and their associated program |
29981 | addresses for the given source filename. The entries are sorted in | |
29982 | ascending PC order. | |
922fbb7b AC |
29983 | |
29984 | @subsubheading @value{GDBN} Command | |
29985 | ||
a2c02241 | 29986 | There is no corresponding @value{GDBN} command. |
922fbb7b AC |
29987 | |
29988 | @subsubheading Example | |
a2c02241 | 29989 | @smallexample |
594fe323 | 29990 | (gdb) |
a2c02241 NR |
29991 | -symbol-list-lines basics.c |
29992 | ^done,lines=[@{pc="0x08048554",line="7"@},@{pc="0x0804855a",line="8"@}] | |
594fe323 | 29993 | (gdb) |
a2c02241 | 29994 | @end smallexample |
922fbb7b AC |
29995 | |
29996 | ||
9901a55b | 29997 | @ignore |
a2c02241 NR |
29998 | @subheading The @code{-symbol-list-types} Command |
29999 | @findex -symbol-list-types | |
922fbb7b AC |
30000 | |
30001 | @subsubheading Synopsis | |
30002 | ||
30003 | @smallexample | |
a2c02241 | 30004 | -symbol-list-types |
922fbb7b AC |
30005 | @end smallexample |
30006 | ||
a2c02241 | 30007 | List all the type names. |
922fbb7b AC |
30008 | |
30009 | @subsubheading @value{GDBN} Command | |
30010 | ||
a2c02241 NR |
30011 | The corresponding commands are @samp{info types} in @value{GDBN}, |
30012 | @samp{gdb_search} in @code{gdbtk}. | |
922fbb7b AC |
30013 | |
30014 | @subsubheading Example | |
30015 | N.A. | |
30016 | ||
30017 | ||
a2c02241 NR |
30018 | @subheading The @code{-symbol-list-variables} Command |
30019 | @findex -symbol-list-variables | |
922fbb7b AC |
30020 | |
30021 | @subsubheading Synopsis | |
30022 | ||
30023 | @smallexample | |
a2c02241 | 30024 | -symbol-list-variables |
922fbb7b AC |
30025 | @end smallexample |
30026 | ||
a2c02241 | 30027 | List all the global and static variable names. |
922fbb7b AC |
30028 | |
30029 | @subsubheading @value{GDBN} Command | |
30030 | ||
a2c02241 | 30031 | @samp{info variables} in @value{GDBN}, @samp{gdb_search} in @code{gdbtk}. |
922fbb7b AC |
30032 | |
30033 | @subsubheading Example | |
30034 | N.A. | |
30035 | ||
30036 | ||
a2c02241 NR |
30037 | @subheading The @code{-symbol-locate} Command |
30038 | @findex -symbol-locate | |
922fbb7b AC |
30039 | |
30040 | @subsubheading Synopsis | |
30041 | ||
30042 | @smallexample | |
a2c02241 | 30043 | -symbol-locate |
922fbb7b AC |
30044 | @end smallexample |
30045 | ||
922fbb7b AC |
30046 | @subsubheading @value{GDBN} Command |
30047 | ||
a2c02241 | 30048 | @samp{gdb_loc} in @code{gdbtk}. |
922fbb7b AC |
30049 | |
30050 | @subsubheading Example | |
30051 | N.A. | |
30052 | ||
30053 | ||
a2c02241 NR |
30054 | @subheading The @code{-symbol-type} Command |
30055 | @findex -symbol-type | |
922fbb7b AC |
30056 | |
30057 | @subsubheading Synopsis | |
30058 | ||
30059 | @smallexample | |
a2c02241 | 30060 | -symbol-type @var{variable} |
922fbb7b AC |
30061 | @end smallexample |
30062 | ||
a2c02241 | 30063 | Show type of @var{variable}. |
922fbb7b | 30064 | |
a2c02241 | 30065 | @subsubheading @value{GDBN} Command |
922fbb7b | 30066 | |
a2c02241 NR |
30067 | The corresponding @value{GDBN} command is @samp{ptype}, @code{gdbtk} has |
30068 | @samp{gdb_obj_variable}. | |
30069 | ||
30070 | @subsubheading Example | |
30071 | N.A. | |
9901a55b | 30072 | @end ignore |
a2c02241 NR |
30073 | |
30074 | ||
30075 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
30076 | @node GDB/MI File Commands | |
30077 | @section @sc{gdb/mi} File Commands | |
30078 | ||
30079 | This section describes the GDB/MI commands to specify executable file names | |
30080 | and to read in and obtain symbol table information. | |
30081 | ||
30082 | @subheading The @code{-file-exec-and-symbols} Command | |
30083 | @findex -file-exec-and-symbols | |
30084 | ||
30085 | @subsubheading Synopsis | |
922fbb7b AC |
30086 | |
30087 | @smallexample | |
a2c02241 | 30088 | -file-exec-and-symbols @var{file} |
922fbb7b AC |
30089 | @end smallexample |
30090 | ||
a2c02241 NR |
30091 | Specify the executable file to be debugged. This file is the one from |
30092 | which the symbol table is also read. If no file is specified, the | |
30093 | command clears the executable and symbol information. If breakpoints | |
30094 | are set when using this command with no arguments, @value{GDBN} will produce | |
30095 | error messages. Otherwise, no output is produced, except a completion | |
30096 | notification. | |
30097 | ||
922fbb7b AC |
30098 | @subsubheading @value{GDBN} Command |
30099 | ||
a2c02241 | 30100 | The corresponding @value{GDBN} command is @samp{file}. |
922fbb7b AC |
30101 | |
30102 | @subsubheading Example | |
30103 | ||
30104 | @smallexample | |
594fe323 | 30105 | (gdb) |
a2c02241 NR |
30106 | -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
30107 | ^done | |
594fe323 | 30108 | (gdb) |
922fbb7b AC |
30109 | @end smallexample |
30110 | ||
922fbb7b | 30111 | |
a2c02241 NR |
30112 | @subheading The @code{-file-exec-file} Command |
30113 | @findex -file-exec-file | |
922fbb7b AC |
30114 | |
30115 | @subsubheading Synopsis | |
30116 | ||
30117 | @smallexample | |
a2c02241 | 30118 | -file-exec-file @var{file} |
922fbb7b AC |
30119 | @end smallexample |
30120 | ||
a2c02241 NR |
30121 | Specify the executable file to be debugged. Unlike |
30122 | @samp{-file-exec-and-symbols}, the symbol table is @emph{not} read | |
30123 | from this file. If used without argument, @value{GDBN} clears the information | |
30124 | about the executable file. No output is produced, except a completion | |
30125 | notification. | |
922fbb7b | 30126 | |
a2c02241 NR |
30127 | @subsubheading @value{GDBN} Command |
30128 | ||
30129 | The corresponding @value{GDBN} command is @samp{exec-file}. | |
922fbb7b AC |
30130 | |
30131 | @subsubheading Example | |
a2c02241 NR |
30132 | |
30133 | @smallexample | |
594fe323 | 30134 | (gdb) |
a2c02241 NR |
30135 | -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
30136 | ^done | |
594fe323 | 30137 | (gdb) |
a2c02241 | 30138 | @end smallexample |
922fbb7b AC |
30139 | |
30140 | ||
9901a55b | 30141 | @ignore |
a2c02241 NR |
30142 | @subheading The @code{-file-list-exec-sections} Command |
30143 | @findex -file-list-exec-sections | |
922fbb7b AC |
30144 | |
30145 | @subsubheading Synopsis | |
30146 | ||
30147 | @smallexample | |
a2c02241 | 30148 | -file-list-exec-sections |
922fbb7b AC |
30149 | @end smallexample |
30150 | ||
a2c02241 NR |
30151 | List the sections of the current executable file. |
30152 | ||
922fbb7b AC |
30153 | @subsubheading @value{GDBN} Command |
30154 | ||
a2c02241 NR |
30155 | The @value{GDBN} command @samp{info file} shows, among the rest, the same |
30156 | information as this command. @code{gdbtk} has a corresponding command | |
30157 | @samp{gdb_load_info}. | |
922fbb7b AC |
30158 | |
30159 | @subsubheading Example | |
30160 | N.A. | |
9901a55b | 30161 | @end ignore |
922fbb7b AC |
30162 | |
30163 | ||
a2c02241 NR |
30164 | @subheading The @code{-file-list-exec-source-file} Command |
30165 | @findex -file-list-exec-source-file | |
922fbb7b AC |
30166 | |
30167 | @subsubheading Synopsis | |
30168 | ||
30169 | @smallexample | |
a2c02241 | 30170 | -file-list-exec-source-file |
922fbb7b AC |
30171 | @end smallexample |
30172 | ||
a2c02241 | 30173 | List the line number, the current source file, and the absolute path |
44288b44 NR |
30174 | to the current source file for the current executable. The macro |
30175 | information field has a value of @samp{1} or @samp{0} depending on | |
30176 | whether or not the file includes preprocessor macro information. | |
922fbb7b AC |
30177 | |
30178 | @subsubheading @value{GDBN} Command | |
30179 | ||
a2c02241 | 30180 | The @value{GDBN} equivalent is @samp{info source} |
922fbb7b AC |
30181 | |
30182 | @subsubheading Example | |
30183 | ||
922fbb7b | 30184 | @smallexample |
594fe323 | 30185 | (gdb) |
a2c02241 | 30186 | 123-file-list-exec-source-file |
44288b44 | 30187 | 123^done,line="1",file="foo.c",fullname="/home/bar/foo.c,macro-info="1" |
594fe323 | 30188 | (gdb) |
922fbb7b AC |
30189 | @end smallexample |
30190 | ||
30191 | ||
a2c02241 NR |
30192 | @subheading The @code{-file-list-exec-source-files} Command |
30193 | @findex -file-list-exec-source-files | |
922fbb7b AC |
30194 | |
30195 | @subsubheading Synopsis | |
30196 | ||
30197 | @smallexample | |
a2c02241 | 30198 | -file-list-exec-source-files |
922fbb7b AC |
30199 | @end smallexample |
30200 | ||
a2c02241 NR |
30201 | List the source files for the current executable. |
30202 | ||
f35a17b5 JK |
30203 | It will always output both the filename and fullname (absolute file |
30204 | name) of a source file. | |
922fbb7b AC |
30205 | |
30206 | @subsubheading @value{GDBN} Command | |
30207 | ||
a2c02241 NR |
30208 | The @value{GDBN} equivalent is @samp{info sources}. |
30209 | @code{gdbtk} has an analogous command @samp{gdb_listfiles}. | |
922fbb7b AC |
30210 | |
30211 | @subsubheading Example | |
922fbb7b | 30212 | @smallexample |
594fe323 | 30213 | (gdb) |
a2c02241 NR |
30214 | -file-list-exec-source-files |
30215 | ^done,files=[ | |
30216 | @{file=foo.c,fullname=/home/foo.c@}, | |
30217 | @{file=/home/bar.c,fullname=/home/bar.c@}, | |
30218 | @{file=gdb_could_not_find_fullpath.c@}] | |
594fe323 | 30219 | (gdb) |
922fbb7b AC |
30220 | @end smallexample |
30221 | ||
9901a55b | 30222 | @ignore |
a2c02241 NR |
30223 | @subheading The @code{-file-list-shared-libraries} Command |
30224 | @findex -file-list-shared-libraries | |
922fbb7b | 30225 | |
a2c02241 | 30226 | @subsubheading Synopsis |
922fbb7b | 30227 | |
a2c02241 NR |
30228 | @smallexample |
30229 | -file-list-shared-libraries | |
30230 | @end smallexample | |
922fbb7b | 30231 | |
a2c02241 | 30232 | List the shared libraries in the program. |
922fbb7b | 30233 | |
a2c02241 | 30234 | @subsubheading @value{GDBN} Command |
922fbb7b | 30235 | |
a2c02241 | 30236 | The corresponding @value{GDBN} command is @samp{info shared}. |
922fbb7b | 30237 | |
a2c02241 NR |
30238 | @subsubheading Example |
30239 | N.A. | |
922fbb7b AC |
30240 | |
30241 | ||
a2c02241 NR |
30242 | @subheading The @code{-file-list-symbol-files} Command |
30243 | @findex -file-list-symbol-files | |
922fbb7b | 30244 | |
a2c02241 | 30245 | @subsubheading Synopsis |
922fbb7b | 30246 | |
a2c02241 NR |
30247 | @smallexample |
30248 | -file-list-symbol-files | |
30249 | @end smallexample | |
922fbb7b | 30250 | |
a2c02241 | 30251 | List symbol files. |
922fbb7b | 30252 | |
a2c02241 | 30253 | @subsubheading @value{GDBN} Command |
922fbb7b | 30254 | |
a2c02241 | 30255 | The corresponding @value{GDBN} command is @samp{info file} (part of it). |
922fbb7b | 30256 | |
a2c02241 NR |
30257 | @subsubheading Example |
30258 | N.A. | |
9901a55b | 30259 | @end ignore |
922fbb7b | 30260 | |
922fbb7b | 30261 | |
a2c02241 NR |
30262 | @subheading The @code{-file-symbol-file} Command |
30263 | @findex -file-symbol-file | |
922fbb7b | 30264 | |
a2c02241 | 30265 | @subsubheading Synopsis |
922fbb7b | 30266 | |
a2c02241 NR |
30267 | @smallexample |
30268 | -file-symbol-file @var{file} | |
30269 | @end smallexample | |
922fbb7b | 30270 | |
a2c02241 NR |
30271 | Read symbol table info from the specified @var{file} argument. When |
30272 | used without arguments, clears @value{GDBN}'s symbol table info. No output is | |
30273 | produced, except for a completion notification. | |
922fbb7b | 30274 | |
a2c02241 | 30275 | @subsubheading @value{GDBN} Command |
922fbb7b | 30276 | |
a2c02241 | 30277 | The corresponding @value{GDBN} command is @samp{symbol-file}. |
922fbb7b | 30278 | |
a2c02241 | 30279 | @subsubheading Example |
922fbb7b | 30280 | |
a2c02241 | 30281 | @smallexample |
594fe323 | 30282 | (gdb) |
a2c02241 NR |
30283 | -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
30284 | ^done | |
594fe323 | 30285 | (gdb) |
a2c02241 | 30286 | @end smallexample |
922fbb7b | 30287 | |
a2c02241 | 30288 | @ignore |
a2c02241 NR |
30289 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30290 | @node GDB/MI Memory Overlay Commands | |
30291 | @section @sc{gdb/mi} Memory Overlay Commands | |
922fbb7b | 30292 | |
a2c02241 | 30293 | The memory overlay commands are not implemented. |
922fbb7b | 30294 | |
a2c02241 | 30295 | @c @subheading -overlay-auto |
922fbb7b | 30296 | |
a2c02241 | 30297 | @c @subheading -overlay-list-mapping-state |
922fbb7b | 30298 | |
a2c02241 | 30299 | @c @subheading -overlay-list-overlays |
922fbb7b | 30300 | |
a2c02241 | 30301 | @c @subheading -overlay-map |
922fbb7b | 30302 | |
a2c02241 | 30303 | @c @subheading -overlay-off |
922fbb7b | 30304 | |
a2c02241 | 30305 | @c @subheading -overlay-on |
922fbb7b | 30306 | |
a2c02241 | 30307 | @c @subheading -overlay-unmap |
922fbb7b | 30308 | |
a2c02241 NR |
30309 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30310 | @node GDB/MI Signal Handling Commands | |
30311 | @section @sc{gdb/mi} Signal Handling Commands | |
922fbb7b | 30312 | |
a2c02241 | 30313 | Signal handling commands are not implemented. |
922fbb7b | 30314 | |
a2c02241 | 30315 | @c @subheading -signal-handle |
922fbb7b | 30316 | |
a2c02241 | 30317 | @c @subheading -signal-list-handle-actions |
922fbb7b | 30318 | |
a2c02241 NR |
30319 | @c @subheading -signal-list-signal-types |
30320 | @end ignore | |
922fbb7b | 30321 | |
922fbb7b | 30322 | |
a2c02241 NR |
30323 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30324 | @node GDB/MI Target Manipulation | |
30325 | @section @sc{gdb/mi} Target Manipulation Commands | |
922fbb7b AC |
30326 | |
30327 | ||
a2c02241 NR |
30328 | @subheading The @code{-target-attach} Command |
30329 | @findex -target-attach | |
922fbb7b AC |
30330 | |
30331 | @subsubheading Synopsis | |
30332 | ||
30333 | @smallexample | |
c3b108f7 | 30334 | -target-attach @var{pid} | @var{gid} | @var{file} |
922fbb7b AC |
30335 | @end smallexample |
30336 | ||
c3b108f7 VP |
30337 | Attach to a process @var{pid} or a file @var{file} outside of |
30338 | @value{GDBN}, or a thread group @var{gid}. If attaching to a thread | |
30339 | group, the id previously returned by | |
30340 | @samp{-list-thread-groups --available} must be used. | |
922fbb7b | 30341 | |
79a6e687 | 30342 | @subsubheading @value{GDBN} Command |
922fbb7b | 30343 | |
a2c02241 | 30344 | The corresponding @value{GDBN} command is @samp{attach}. |
922fbb7b | 30345 | |
a2c02241 | 30346 | @subsubheading Example |
b56e7235 VP |
30347 | @smallexample |
30348 | (gdb) | |
30349 | -target-attach 34 | |
30350 | =thread-created,id="1" | |
5ae4183a | 30351 | *stopped,thread-id="1",frame=@{addr="0xb7f7e410",func="bar",args=[]@} |
b56e7235 VP |
30352 | ^done |
30353 | (gdb) | |
30354 | @end smallexample | |
a2c02241 | 30355 | |
9901a55b | 30356 | @ignore |
a2c02241 NR |
30357 | @subheading The @code{-target-compare-sections} Command |
30358 | @findex -target-compare-sections | |
922fbb7b AC |
30359 | |
30360 | @subsubheading Synopsis | |
30361 | ||
30362 | @smallexample | |
a2c02241 | 30363 | -target-compare-sections [ @var{section} ] |
922fbb7b AC |
30364 | @end smallexample |
30365 | ||
a2c02241 NR |
30366 | Compare data of section @var{section} on target to the exec file. |
30367 | Without the argument, all sections are compared. | |
922fbb7b | 30368 | |
a2c02241 | 30369 | @subsubheading @value{GDBN} Command |
922fbb7b | 30370 | |
a2c02241 | 30371 | The @value{GDBN} equivalent is @samp{compare-sections}. |
922fbb7b | 30372 | |
a2c02241 NR |
30373 | @subsubheading Example |
30374 | N.A. | |
9901a55b | 30375 | @end ignore |
a2c02241 NR |
30376 | |
30377 | ||
30378 | @subheading The @code{-target-detach} Command | |
30379 | @findex -target-detach | |
922fbb7b AC |
30380 | |
30381 | @subsubheading Synopsis | |
30382 | ||
30383 | @smallexample | |
c3b108f7 | 30384 | -target-detach [ @var{pid} | @var{gid} ] |
922fbb7b AC |
30385 | @end smallexample |
30386 | ||
a2c02241 | 30387 | Detach from the remote target which normally resumes its execution. |
c3b108f7 VP |
30388 | If either @var{pid} or @var{gid} is specified, detaches from either |
30389 | the specified process, or specified thread group. There's no output. | |
a2c02241 | 30390 | |
79a6e687 | 30391 | @subsubheading @value{GDBN} Command |
a2c02241 NR |
30392 | |
30393 | The corresponding @value{GDBN} command is @samp{detach}. | |
30394 | ||
30395 | @subsubheading Example | |
922fbb7b AC |
30396 | |
30397 | @smallexample | |
594fe323 | 30398 | (gdb) |
a2c02241 NR |
30399 | -target-detach |
30400 | ^done | |
594fe323 | 30401 | (gdb) |
922fbb7b AC |
30402 | @end smallexample |
30403 | ||
30404 | ||
a2c02241 NR |
30405 | @subheading The @code{-target-disconnect} Command |
30406 | @findex -target-disconnect | |
922fbb7b AC |
30407 | |
30408 | @subsubheading Synopsis | |
30409 | ||
123dc839 | 30410 | @smallexample |
a2c02241 | 30411 | -target-disconnect |
123dc839 | 30412 | @end smallexample |
922fbb7b | 30413 | |
a2c02241 NR |
30414 | Disconnect from the remote target. There's no output and the target is |
30415 | generally not resumed. | |
30416 | ||
79a6e687 | 30417 | @subsubheading @value{GDBN} Command |
a2c02241 NR |
30418 | |
30419 | The corresponding @value{GDBN} command is @samp{disconnect}. | |
bc8ced35 NR |
30420 | |
30421 | @subsubheading Example | |
922fbb7b AC |
30422 | |
30423 | @smallexample | |
594fe323 | 30424 | (gdb) |
a2c02241 NR |
30425 | -target-disconnect |
30426 | ^done | |
594fe323 | 30427 | (gdb) |
922fbb7b AC |
30428 | @end smallexample |
30429 | ||
30430 | ||
a2c02241 NR |
30431 | @subheading The @code{-target-download} Command |
30432 | @findex -target-download | |
922fbb7b AC |
30433 | |
30434 | @subsubheading Synopsis | |
30435 | ||
30436 | @smallexample | |
a2c02241 | 30437 | -target-download |
922fbb7b AC |
30438 | @end smallexample |
30439 | ||
a2c02241 NR |
30440 | Loads the executable onto the remote target. |
30441 | It prints out an update message every half second, which includes the fields: | |
30442 | ||
30443 | @table @samp | |
30444 | @item section | |
30445 | The name of the section. | |
30446 | @item section-sent | |
30447 | The size of what has been sent so far for that section. | |
30448 | @item section-size | |
30449 | The size of the section. | |
30450 | @item total-sent | |
30451 | The total size of what was sent so far (the current and the previous sections). | |
30452 | @item total-size | |
30453 | The size of the overall executable to download. | |
30454 | @end table | |
30455 | ||
30456 | @noindent | |
30457 | Each message is sent as status record (@pxref{GDB/MI Output Syntax, , | |
30458 | @sc{gdb/mi} Output Syntax}). | |
30459 | ||
30460 | In addition, it prints the name and size of the sections, as they are | |
30461 | downloaded. These messages include the following fields: | |
30462 | ||
30463 | @table @samp | |
30464 | @item section | |
30465 | The name of the section. | |
30466 | @item section-size | |
30467 | The size of the section. | |
30468 | @item total-size | |
30469 | The size of the overall executable to download. | |
30470 | @end table | |
30471 | ||
30472 | @noindent | |
30473 | At the end, a summary is printed. | |
30474 | ||
30475 | @subsubheading @value{GDBN} Command | |
30476 | ||
30477 | The corresponding @value{GDBN} command is @samp{load}. | |
30478 | ||
30479 | @subsubheading Example | |
30480 | ||
30481 | Note: each status message appears on a single line. Here the messages | |
30482 | have been broken down so that they can fit onto a page. | |
922fbb7b AC |
30483 | |
30484 | @smallexample | |
594fe323 | 30485 | (gdb) |
a2c02241 NR |
30486 | -target-download |
30487 | +download,@{section=".text",section-size="6668",total-size="9880"@} | |
30488 | +download,@{section=".text",section-sent="512",section-size="6668", | |
30489 | total-sent="512",total-size="9880"@} | |
30490 | +download,@{section=".text",section-sent="1024",section-size="6668", | |
30491 | total-sent="1024",total-size="9880"@} | |
30492 | +download,@{section=".text",section-sent="1536",section-size="6668", | |
30493 | total-sent="1536",total-size="9880"@} | |
30494 | +download,@{section=".text",section-sent="2048",section-size="6668", | |
30495 | total-sent="2048",total-size="9880"@} | |
30496 | +download,@{section=".text",section-sent="2560",section-size="6668", | |
30497 | total-sent="2560",total-size="9880"@} | |
30498 | +download,@{section=".text",section-sent="3072",section-size="6668", | |
30499 | total-sent="3072",total-size="9880"@} | |
30500 | +download,@{section=".text",section-sent="3584",section-size="6668", | |
30501 | total-sent="3584",total-size="9880"@} | |
30502 | +download,@{section=".text",section-sent="4096",section-size="6668", | |
30503 | total-sent="4096",total-size="9880"@} | |
30504 | +download,@{section=".text",section-sent="4608",section-size="6668", | |
30505 | total-sent="4608",total-size="9880"@} | |
30506 | +download,@{section=".text",section-sent="5120",section-size="6668", | |
30507 | total-sent="5120",total-size="9880"@} | |
30508 | +download,@{section=".text",section-sent="5632",section-size="6668", | |
30509 | total-sent="5632",total-size="9880"@} | |
30510 | +download,@{section=".text",section-sent="6144",section-size="6668", | |
30511 | total-sent="6144",total-size="9880"@} | |
30512 | +download,@{section=".text",section-sent="6656",section-size="6668", | |
30513 | total-sent="6656",total-size="9880"@} | |
30514 | +download,@{section=".init",section-size="28",total-size="9880"@} | |
30515 | +download,@{section=".fini",section-size="28",total-size="9880"@} | |
30516 | +download,@{section=".data",section-size="3156",total-size="9880"@} | |
30517 | +download,@{section=".data",section-sent="512",section-size="3156", | |
30518 | total-sent="7236",total-size="9880"@} | |
30519 | +download,@{section=".data",section-sent="1024",section-size="3156", | |
30520 | total-sent="7748",total-size="9880"@} | |
30521 | +download,@{section=".data",section-sent="1536",section-size="3156", | |
30522 | total-sent="8260",total-size="9880"@} | |
30523 | +download,@{section=".data",section-sent="2048",section-size="3156", | |
30524 | total-sent="8772",total-size="9880"@} | |
30525 | +download,@{section=".data",section-sent="2560",section-size="3156", | |
30526 | total-sent="9284",total-size="9880"@} | |
30527 | +download,@{section=".data",section-sent="3072",section-size="3156", | |
30528 | total-sent="9796",total-size="9880"@} | |
30529 | ^done,address="0x10004",load-size="9880",transfer-rate="6586", | |
30530 | write-rate="429" | |
594fe323 | 30531 | (gdb) |
922fbb7b AC |
30532 | @end smallexample |
30533 | ||
30534 | ||
9901a55b | 30535 | @ignore |
a2c02241 NR |
30536 | @subheading The @code{-target-exec-status} Command |
30537 | @findex -target-exec-status | |
922fbb7b AC |
30538 | |
30539 | @subsubheading Synopsis | |
30540 | ||
30541 | @smallexample | |
a2c02241 | 30542 | -target-exec-status |
922fbb7b AC |
30543 | @end smallexample |
30544 | ||
a2c02241 NR |
30545 | Provide information on the state of the target (whether it is running or |
30546 | not, for instance). | |
922fbb7b | 30547 | |
a2c02241 | 30548 | @subsubheading @value{GDBN} Command |
922fbb7b | 30549 | |
a2c02241 NR |
30550 | There's no equivalent @value{GDBN} command. |
30551 | ||
30552 | @subsubheading Example | |
30553 | N.A. | |
922fbb7b | 30554 | |
a2c02241 NR |
30555 | |
30556 | @subheading The @code{-target-list-available-targets} Command | |
30557 | @findex -target-list-available-targets | |
922fbb7b AC |
30558 | |
30559 | @subsubheading Synopsis | |
30560 | ||
30561 | @smallexample | |
a2c02241 | 30562 | -target-list-available-targets |
922fbb7b AC |
30563 | @end smallexample |
30564 | ||
a2c02241 | 30565 | List the possible targets to connect to. |
922fbb7b | 30566 | |
a2c02241 | 30567 | @subsubheading @value{GDBN} Command |
922fbb7b | 30568 | |
a2c02241 | 30569 | The corresponding @value{GDBN} command is @samp{help target}. |
922fbb7b | 30570 | |
a2c02241 NR |
30571 | @subsubheading Example |
30572 | N.A. | |
30573 | ||
30574 | ||
30575 | @subheading The @code{-target-list-current-targets} Command | |
30576 | @findex -target-list-current-targets | |
922fbb7b AC |
30577 | |
30578 | @subsubheading Synopsis | |
30579 | ||
30580 | @smallexample | |
a2c02241 | 30581 | -target-list-current-targets |
922fbb7b AC |
30582 | @end smallexample |
30583 | ||
a2c02241 | 30584 | Describe the current target. |
922fbb7b | 30585 | |
a2c02241 | 30586 | @subsubheading @value{GDBN} Command |
922fbb7b | 30587 | |
a2c02241 NR |
30588 | The corresponding information is printed by @samp{info file} (among |
30589 | other things). | |
922fbb7b | 30590 | |
a2c02241 NR |
30591 | @subsubheading Example |
30592 | N.A. | |
30593 | ||
30594 | ||
30595 | @subheading The @code{-target-list-parameters} Command | |
30596 | @findex -target-list-parameters | |
922fbb7b AC |
30597 | |
30598 | @subsubheading Synopsis | |
30599 | ||
30600 | @smallexample | |
a2c02241 | 30601 | -target-list-parameters |
922fbb7b AC |
30602 | @end smallexample |
30603 | ||
a2c02241 | 30604 | @c ???? |
9901a55b | 30605 | @end ignore |
a2c02241 NR |
30606 | |
30607 | @subsubheading @value{GDBN} Command | |
30608 | ||
30609 | No equivalent. | |
922fbb7b AC |
30610 | |
30611 | @subsubheading Example | |
a2c02241 NR |
30612 | N.A. |
30613 | ||
30614 | ||
30615 | @subheading The @code{-target-select} Command | |
30616 | @findex -target-select | |
30617 | ||
30618 | @subsubheading Synopsis | |
922fbb7b AC |
30619 | |
30620 | @smallexample | |
a2c02241 | 30621 | -target-select @var{type} @var{parameters @dots{}} |
922fbb7b AC |
30622 | @end smallexample |
30623 | ||
a2c02241 | 30624 | Connect @value{GDBN} to the remote target. This command takes two args: |
922fbb7b | 30625 | |
a2c02241 NR |
30626 | @table @samp |
30627 | @item @var{type} | |
75c99385 | 30628 | The type of target, for instance @samp{remote}, etc. |
a2c02241 NR |
30629 | @item @var{parameters} |
30630 | Device names, host names and the like. @xref{Target Commands, , | |
79a6e687 | 30631 | Commands for Managing Targets}, for more details. |
a2c02241 NR |
30632 | @end table |
30633 | ||
30634 | The output is a connection notification, followed by the address at | |
30635 | which the target program is, in the following form: | |
922fbb7b AC |
30636 | |
30637 | @smallexample | |
a2c02241 NR |
30638 | ^connected,addr="@var{address}",func="@var{function name}", |
30639 | args=[@var{arg list}] | |
922fbb7b AC |
30640 | @end smallexample |
30641 | ||
a2c02241 NR |
30642 | @subsubheading @value{GDBN} Command |
30643 | ||
30644 | The corresponding @value{GDBN} command is @samp{target}. | |
265eeb58 NR |
30645 | |
30646 | @subsubheading Example | |
922fbb7b | 30647 | |
265eeb58 | 30648 | @smallexample |
594fe323 | 30649 | (gdb) |
75c99385 | 30650 | -target-select remote /dev/ttya |
a2c02241 | 30651 | ^connected,addr="0xfe00a300",func="??",args=[] |
594fe323 | 30652 | (gdb) |
265eeb58 | 30653 | @end smallexample |
ef21caaf | 30654 | |
a6b151f1 DJ |
30655 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30656 | @node GDB/MI File Transfer Commands | |
30657 | @section @sc{gdb/mi} File Transfer Commands | |
30658 | ||
30659 | ||
30660 | @subheading The @code{-target-file-put} Command | |
30661 | @findex -target-file-put | |
30662 | ||
30663 | @subsubheading Synopsis | |
30664 | ||
30665 | @smallexample | |
30666 | -target-file-put @var{hostfile} @var{targetfile} | |
30667 | @end smallexample | |
30668 | ||
30669 | Copy file @var{hostfile} from the host system (the machine running | |
30670 | @value{GDBN}) to @var{targetfile} on the target system. | |
30671 | ||
30672 | @subsubheading @value{GDBN} Command | |
30673 | ||
30674 | The corresponding @value{GDBN} command is @samp{remote put}. | |
30675 | ||
30676 | @subsubheading Example | |
30677 | ||
30678 | @smallexample | |
30679 | (gdb) | |
30680 | -target-file-put localfile remotefile | |
30681 | ^done | |
30682 | (gdb) | |
30683 | @end smallexample | |
30684 | ||
30685 | ||
1763a388 | 30686 | @subheading The @code{-target-file-get} Command |
a6b151f1 DJ |
30687 | @findex -target-file-get |
30688 | ||
30689 | @subsubheading Synopsis | |
30690 | ||
30691 | @smallexample | |
30692 | -target-file-get @var{targetfile} @var{hostfile} | |
30693 | @end smallexample | |
30694 | ||
30695 | Copy file @var{targetfile} from the target system to @var{hostfile} | |
30696 | on the host system. | |
30697 | ||
30698 | @subsubheading @value{GDBN} Command | |
30699 | ||
30700 | The corresponding @value{GDBN} command is @samp{remote get}. | |
30701 | ||
30702 | @subsubheading Example | |
30703 | ||
30704 | @smallexample | |
30705 | (gdb) | |
30706 | -target-file-get remotefile localfile | |
30707 | ^done | |
30708 | (gdb) | |
30709 | @end smallexample | |
30710 | ||
30711 | ||
30712 | @subheading The @code{-target-file-delete} Command | |
30713 | @findex -target-file-delete | |
30714 | ||
30715 | @subsubheading Synopsis | |
30716 | ||
30717 | @smallexample | |
30718 | -target-file-delete @var{targetfile} | |
30719 | @end smallexample | |
30720 | ||
30721 | Delete @var{targetfile} from the target system. | |
30722 | ||
30723 | @subsubheading @value{GDBN} Command | |
30724 | ||
30725 | The corresponding @value{GDBN} command is @samp{remote delete}. | |
30726 | ||
30727 | @subsubheading Example | |
30728 | ||
30729 | @smallexample | |
30730 | (gdb) | |
30731 | -target-file-delete remotefile | |
30732 | ^done | |
30733 | (gdb) | |
30734 | @end smallexample | |
30735 | ||
30736 | ||
58d06528 JB |
30737 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30738 | @node GDB/MI Ada Exceptions Commands | |
30739 | @section Ada Exceptions @sc{gdb/mi} Commands | |
30740 | ||
30741 | @subheading The @code{-info-ada-exceptions} Command | |
30742 | @findex -info-ada-exceptions | |
30743 | ||
30744 | @subsubheading Synopsis | |
30745 | ||
30746 | @smallexample | |
30747 | -info-ada-exceptions [ @var{regexp}] | |
30748 | @end smallexample | |
30749 | ||
30750 | List all Ada exceptions defined within the program being debugged. | |
30751 | With a regular expression @var{regexp}, only those exceptions whose | |
30752 | names match @var{regexp} are listed. | |
30753 | ||
30754 | @subsubheading @value{GDBN} Command | |
30755 | ||
30756 | The corresponding @value{GDBN} command is @samp{info exceptions}. | |
30757 | ||
30758 | @subsubheading Result | |
30759 | ||
30760 | The result is a table of Ada exceptions. The following columns are | |
30761 | defined for each exception: | |
30762 | ||
30763 | @table @samp | |
30764 | @item name | |
30765 | The name of the exception. | |
30766 | ||
30767 | @item address | |
30768 | The address of the exception. | |
30769 | ||
30770 | @end table | |
30771 | ||
30772 | @subsubheading Example | |
30773 | ||
30774 | @smallexample | |
30775 | -info-ada-exceptions aint | |
30776 | ^done,ada-exceptions=@{nr_rows="2",nr_cols="2", | |
30777 | hdr=[@{width="1",alignment="-1",col_name="name",colhdr="Name"@}, | |
30778 | @{width="1",alignment="-1",col_name="address",colhdr="Address"@}], | |
30779 | body=[@{name="constraint_error",address="0x0000000000613da0"@}, | |
30780 | @{name="const.aint_global_e",address="0x0000000000613b00"@}]@} | |
30781 | @end smallexample | |
30782 | ||
30783 | @subheading Catching Ada Exceptions | |
30784 | ||
30785 | The commands describing how to ask @value{GDBN} to stop when a program | |
30786 | raises an exception are described at @ref{Ada Exception GDB/MI | |
30787 | Catchpoint Commands}. | |
30788 | ||
30789 | ||
ef21caaf | 30790 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
d192b373 JB |
30791 | @node GDB/MI Support Commands |
30792 | @section @sc{gdb/mi} Support Commands | |
ef21caaf | 30793 | |
d192b373 JB |
30794 | Since new commands and features get regularly added to @sc{gdb/mi}, |
30795 | some commands are available to help front-ends query the debugger | |
30796 | about support for these capabilities. Similarly, it is also possible | |
30797 | to query @value{GDBN} about target support of certain features. | |
ef21caaf | 30798 | |
6b7cbff1 JB |
30799 | @subheading The @code{-info-gdb-mi-command} Command |
30800 | @cindex @code{-info-gdb-mi-command} | |
30801 | @findex -info-gdb-mi-command | |
30802 | ||
30803 | @subsubheading Synopsis | |
30804 | ||
30805 | @smallexample | |
30806 | -info-gdb-mi-command @var{cmd_name} | |
30807 | @end smallexample | |
30808 | ||
30809 | Query support for the @sc{gdb/mi} command named @var{cmd_name}. | |
30810 | ||
30811 | Note that the dash (@code{-}) starting all @sc{gdb/mi} commands | |
30812 | is technically not part of the command name (@pxref{GDB/MI Input | |
30813 | Syntax}), and thus should be omitted in @var{cmd_name}. However, | |
30814 | for ease of use, this command also accepts the form with the leading | |
30815 | dash. | |
30816 | ||
30817 | @subsubheading @value{GDBN} Command | |
30818 | ||
30819 | There is no corresponding @value{GDBN} command. | |
30820 | ||
30821 | @subsubheading Result | |
30822 | ||
30823 | The result is a tuple. There is currently only one field: | |
30824 | ||
30825 | @table @samp | |
30826 | @item exists | |
30827 | This field is equal to @code{"true"} if the @sc{gdb/mi} command exists, | |
30828 | @code{"false"} otherwise. | |
30829 | ||
30830 | @end table | |
30831 | ||
30832 | @subsubheading Example | |
30833 | ||
30834 | Here is an example where the @sc{gdb/mi} command does not exist: | |
30835 | ||
30836 | @smallexample | |
30837 | -info-gdb-mi-command unsupported-command | |
30838 | ^done,command=@{exists="false"@} | |
30839 | @end smallexample | |
30840 | ||
30841 | @noindent | |
30842 | And here is an example where the @sc{gdb/mi} command is known | |
30843 | to the debugger: | |
30844 | ||
30845 | @smallexample | |
30846 | -info-gdb-mi-command symbol-list-lines | |
30847 | ^done,command=@{exists="true"@} | |
30848 | @end smallexample | |
30849 | ||
084344da VP |
30850 | @subheading The @code{-list-features} Command |
30851 | @findex -list-features | |
9b26f0fb | 30852 | @cindex supported @sc{gdb/mi} features, list |
084344da VP |
30853 | |
30854 | Returns a list of particular features of the MI protocol that | |
30855 | this version of gdb implements. A feature can be a command, | |
30856 | or a new field in an output of some command, or even an | |
30857 | important bugfix. While a frontend can sometimes detect presence | |
30858 | of a feature at runtime, it is easier to perform detection at debugger | |
d192b373 | 30859 | startup. |
084344da VP |
30860 | |
30861 | The command returns a list of strings, with each string naming an | |
30862 | available feature. Each returned string is just a name, it does not | |
d192b373 | 30863 | have any internal structure. The list of possible feature names |
084344da VP |
30864 | is given below. |
30865 | ||
30866 | Example output: | |
30867 | ||
30868 | @smallexample | |
30869 | (gdb) -list-features | |
30870 | ^done,result=["feature1","feature2"] | |
30871 | @end smallexample | |
30872 | ||
30873 | The current list of features is: | |
30874 | ||
edef6000 | 30875 | @ftable @samp |
30e026bb | 30876 | @item frozen-varobjs |
a05336a1 JB |
30877 | Indicates support for the @code{-var-set-frozen} command, as well |
30878 | as possible presense of the @code{frozen} field in the output | |
30e026bb VP |
30879 | of @code{-varobj-create}. |
30880 | @item pending-breakpoints | |
a05336a1 JB |
30881 | Indicates support for the @option{-f} option to the @code{-break-insert} |
30882 | command. | |
b6313243 | 30883 | @item python |
a05336a1 | 30884 | Indicates Python scripting support, Python-based |
b6313243 TT |
30885 | pretty-printing commands, and possible presence of the |
30886 | @samp{display_hint} field in the output of @code{-var-list-children} | |
30e026bb | 30887 | @item thread-info |
a05336a1 | 30888 | Indicates support for the @code{-thread-info} command. |
8dedea02 | 30889 | @item data-read-memory-bytes |
a05336a1 | 30890 | Indicates support for the @code{-data-read-memory-bytes} and the |
8dedea02 | 30891 | @code{-data-write-memory-bytes} commands. |
39c4d40a TT |
30892 | @item breakpoint-notifications |
30893 | Indicates that changes to breakpoints and breakpoints created via the | |
30894 | CLI will be announced via async records. | |
5d77fe44 | 30895 | @item ada-task-info |
6adcee18 | 30896 | Indicates support for the @code{-ada-task-info} command. |
422ad5c2 JB |
30897 | @item language-option |
30898 | Indicates that all @sc{gdb/mi} commands accept the @option{--language} | |
30899 | option (@pxref{Context management}). | |
6b7cbff1 JB |
30900 | @item info-gdb-mi-command |
30901 | Indicates support for the @code{-info-gdb-mi-command} command. | |
2ea126fa JB |
30902 | @item undefined-command-error-code |
30903 | Indicates support for the "undefined-command" error code in error result | |
30904 | records, produced when trying to execute an undefined @sc{gdb/mi} command | |
30905 | (@pxref{GDB/MI Result Records}). | |
72bfa06c JB |
30906 | @item exec-run-start-option |
30907 | Indicates that the @code{-exec-run} command supports the @option{--start} | |
30908 | option (@pxref{GDB/MI Program Execution}). | |
edef6000 | 30909 | @end ftable |
084344da | 30910 | |
c6ebd6cf VP |
30911 | @subheading The @code{-list-target-features} Command |
30912 | @findex -list-target-features | |
30913 | ||
30914 | Returns a list of particular features that are supported by the | |
30915 | target. Those features affect the permitted MI commands, but | |
30916 | unlike the features reported by the @code{-list-features} command, the | |
30917 | features depend on which target GDB is using at the moment. Whenever | |
30918 | a target can change, due to commands such as @code{-target-select}, | |
30919 | @code{-target-attach} or @code{-exec-run}, the list of target features | |
30920 | may change, and the frontend should obtain it again. | |
30921 | Example output: | |
30922 | ||
30923 | @smallexample | |
b3d3b4bd | 30924 | (gdb) -list-target-features |
c6ebd6cf VP |
30925 | ^done,result=["async"] |
30926 | @end smallexample | |
30927 | ||
30928 | The current list of features is: | |
30929 | ||
30930 | @table @samp | |
30931 | @item async | |
30932 | Indicates that the target is capable of asynchronous command | |
30933 | execution, which means that @value{GDBN} will accept further commands | |
30934 | while the target is running. | |
30935 | ||
f75d858b MK |
30936 | @item reverse |
30937 | Indicates that the target is capable of reverse execution. | |
30938 | @xref{Reverse Execution}, for more information. | |
30939 | ||
c6ebd6cf VP |
30940 | @end table |
30941 | ||
d192b373 JB |
30942 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30943 | @node GDB/MI Miscellaneous Commands | |
30944 | @section Miscellaneous @sc{gdb/mi} Commands | |
30945 | ||
30946 | @c @subheading -gdb-complete | |
30947 | ||
30948 | @subheading The @code{-gdb-exit} Command | |
30949 | @findex -gdb-exit | |
30950 | ||
30951 | @subsubheading Synopsis | |
30952 | ||
30953 | @smallexample | |
30954 | -gdb-exit | |
30955 | @end smallexample | |
30956 | ||
30957 | Exit @value{GDBN} immediately. | |
30958 | ||
30959 | @subsubheading @value{GDBN} Command | |
30960 | ||
30961 | Approximately corresponds to @samp{quit}. | |
30962 | ||
30963 | @subsubheading Example | |
30964 | ||
30965 | @smallexample | |
30966 | (gdb) | |
30967 | -gdb-exit | |
30968 | ^exit | |
30969 | @end smallexample | |
30970 | ||
30971 | ||
30972 | @ignore | |
30973 | @subheading The @code{-exec-abort} Command | |
30974 | @findex -exec-abort | |
30975 | ||
30976 | @subsubheading Synopsis | |
30977 | ||
30978 | @smallexample | |
30979 | -exec-abort | |
30980 | @end smallexample | |
30981 | ||
30982 | Kill the inferior running program. | |
30983 | ||
30984 | @subsubheading @value{GDBN} Command | |
30985 | ||
30986 | The corresponding @value{GDBN} command is @samp{kill}. | |
30987 | ||
30988 | @subsubheading Example | |
30989 | N.A. | |
30990 | @end ignore | |
30991 | ||
30992 | ||
30993 | @subheading The @code{-gdb-set} Command | |
30994 | @findex -gdb-set | |
30995 | ||
30996 | @subsubheading Synopsis | |
30997 | ||
30998 | @smallexample | |
30999 | -gdb-set | |
31000 | @end smallexample | |
31001 | ||
31002 | Set an internal @value{GDBN} variable. | |
31003 | @c IS THIS A DOLLAR VARIABLE? OR SOMETHING LIKE ANNOTATE ????? | |
31004 | ||
31005 | @subsubheading @value{GDBN} Command | |
31006 | ||
31007 | The corresponding @value{GDBN} command is @samp{set}. | |
31008 | ||
31009 | @subsubheading Example | |
31010 | ||
31011 | @smallexample | |
31012 | (gdb) | |
31013 | -gdb-set $foo=3 | |
31014 | ^done | |
31015 | (gdb) | |
31016 | @end smallexample | |
31017 | ||
31018 | ||
31019 | @subheading The @code{-gdb-show} Command | |
31020 | @findex -gdb-show | |
31021 | ||
31022 | @subsubheading Synopsis | |
31023 | ||
31024 | @smallexample | |
31025 | -gdb-show | |
31026 | @end smallexample | |
31027 | ||
31028 | Show the current value of a @value{GDBN} variable. | |
31029 | ||
31030 | @subsubheading @value{GDBN} Command | |
31031 | ||
31032 | The corresponding @value{GDBN} command is @samp{show}. | |
31033 | ||
31034 | @subsubheading Example | |
31035 | ||
31036 | @smallexample | |
31037 | (gdb) | |
31038 | -gdb-show annotate | |
31039 | ^done,value="0" | |
31040 | (gdb) | |
31041 | @end smallexample | |
31042 | ||
31043 | @c @subheading -gdb-source | |
31044 | ||
31045 | ||
31046 | @subheading The @code{-gdb-version} Command | |
31047 | @findex -gdb-version | |
31048 | ||
31049 | @subsubheading Synopsis | |
31050 | ||
31051 | @smallexample | |
31052 | -gdb-version | |
31053 | @end smallexample | |
31054 | ||
31055 | Show version information for @value{GDBN}. Used mostly in testing. | |
31056 | ||
31057 | @subsubheading @value{GDBN} Command | |
31058 | ||
31059 | The @value{GDBN} equivalent is @samp{show version}. @value{GDBN} by | |
31060 | default shows this information when you start an interactive session. | |
31061 | ||
31062 | @subsubheading Example | |
31063 | ||
31064 | @c This example modifies the actual output from GDB to avoid overfull | |
31065 | @c box in TeX. | |
31066 | @smallexample | |
31067 | (gdb) | |
31068 | -gdb-version | |
31069 | ~GNU gdb 5.2.1 | |
31070 | ~Copyright 2000 Free Software Foundation, Inc. | |
31071 | ~GDB is free software, covered by the GNU General Public License, and | |
31072 | ~you are welcome to change it and/or distribute copies of it under | |
31073 | ~ certain conditions. | |
31074 | ~Type "show copying" to see the conditions. | |
31075 | ~There is absolutely no warranty for GDB. Type "show warranty" for | |
31076 | ~ details. | |
31077 | ~This GDB was configured as | |
31078 | "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi". | |
31079 | ^done | |
31080 | (gdb) | |
31081 | @end smallexample | |
31082 | ||
c3b108f7 VP |
31083 | @subheading The @code{-list-thread-groups} Command |
31084 | @findex -list-thread-groups | |
31085 | ||
31086 | @subheading Synopsis | |
31087 | ||
31088 | @smallexample | |
dc146f7c | 31089 | -list-thread-groups [ --available ] [ --recurse 1 ] [ @var{group} ... ] |
c3b108f7 VP |
31090 | @end smallexample |
31091 | ||
dc146f7c VP |
31092 | Lists thread groups (@pxref{Thread groups}). When a single thread |
31093 | group is passed as the argument, lists the children of that group. | |
31094 | When several thread group are passed, lists information about those | |
31095 | thread groups. Without any parameters, lists information about all | |
31096 | top-level thread groups. | |
31097 | ||
31098 | Normally, thread groups that are being debugged are reported. | |
31099 | With the @samp{--available} option, @value{GDBN} reports thread groups | |
31100 | available on the target. | |
31101 | ||
31102 | The output of this command may have either a @samp{threads} result or | |
31103 | a @samp{groups} result. The @samp{thread} result has a list of tuples | |
31104 | as value, with each tuple describing a thread (@pxref{GDB/MI Thread | |
31105 | Information}). The @samp{groups} result has a list of tuples as value, | |
31106 | each tuple describing a thread group. If top-level groups are | |
31107 | requested (that is, no parameter is passed), or when several groups | |
31108 | are passed, the output always has a @samp{groups} result. The format | |
31109 | of the @samp{group} result is described below. | |
31110 | ||
31111 | To reduce the number of roundtrips it's possible to list thread groups | |
31112 | together with their children, by passing the @samp{--recurse} option | |
31113 | and the recursion depth. Presently, only recursion depth of 1 is | |
31114 | permitted. If this option is present, then every reported thread group | |
31115 | will also include its children, either as @samp{group} or | |
31116 | @samp{threads} field. | |
31117 | ||
31118 | In general, any combination of option and parameters is permitted, with | |
31119 | the following caveats: | |
31120 | ||
31121 | @itemize @bullet | |
31122 | @item | |
31123 | When a single thread group is passed, the output will typically | |
31124 | be the @samp{threads} result. Because threads may not contain | |
31125 | anything, the @samp{recurse} option will be ignored. | |
31126 | ||
31127 | @item | |
31128 | When the @samp{--available} option is passed, limited information may | |
31129 | be available. In particular, the list of threads of a process might | |
31130 | be inaccessible. Further, specifying specific thread groups might | |
31131 | not give any performance advantage over listing all thread groups. | |
31132 | The frontend should assume that @samp{-list-thread-groups --available} | |
31133 | is always an expensive operation and cache the results. | |
31134 | ||
31135 | @end itemize | |
31136 | ||
31137 | The @samp{groups} result is a list of tuples, where each tuple may | |
31138 | have the following fields: | |
31139 | ||
31140 | @table @code | |
31141 | @item id | |
31142 | Identifier of the thread group. This field is always present. | |
a79b8f6e VP |
31143 | The identifier is an opaque string; frontends should not try to |
31144 | convert it to an integer, even though it might look like one. | |
dc146f7c VP |
31145 | |
31146 | @item type | |
31147 | The type of the thread group. At present, only @samp{process} is a | |
31148 | valid type. | |
31149 | ||
31150 | @item pid | |
31151 | The target-specific process identifier. This field is only present | |
a79b8f6e | 31152 | for thread groups of type @samp{process} and only if the process exists. |
c3b108f7 | 31153 | |
dc146f7c VP |
31154 | @item num_children |
31155 | The number of children this thread group has. This field may be | |
31156 | absent for an available thread group. | |
31157 | ||
31158 | @item threads | |
31159 | This field has a list of tuples as value, each tuple describing a | |
31160 | thread. It may be present if the @samp{--recurse} option is | |
31161 | specified, and it's actually possible to obtain the threads. | |
31162 | ||
31163 | @item cores | |
31164 | This field is a list of integers, each identifying a core that one | |
31165 | thread of the group is running on. This field may be absent if | |
31166 | such information is not available. | |
31167 | ||
a79b8f6e VP |
31168 | @item executable |
31169 | The name of the executable file that corresponds to this thread group. | |
31170 | The field is only present for thread groups of type @samp{process}, | |
31171 | and only if there is a corresponding executable file. | |
31172 | ||
dc146f7c | 31173 | @end table |
c3b108f7 VP |
31174 | |
31175 | @subheading Example | |
31176 | ||
31177 | @smallexample | |
31178 | @value{GDBP} | |
31179 | -list-thread-groups | |
31180 | ^done,groups=[@{id="17",type="process",pid="yyy",num_children="2"@}] | |
31181 | -list-thread-groups 17 | |
31182 | ^done,threads=[@{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", | |
31183 | frame=@{level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]@},state="running"@}, | |
31184 | @{id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", | |
31185 | frame=@{level="0",addr="0x0804891f",func="foo",args=[@{name="i",value="10"@}], | |
31186 | file="/tmp/a.c",fullname="/tmp/a.c",line="158"@},state="running"@}]] | |
dc146f7c VP |
31187 | -list-thread-groups --available |
31188 | ^done,groups=[@{id="17",type="process",pid="yyy",num_children="2",cores=[1,2]@}] | |
31189 | -list-thread-groups --available --recurse 1 | |
31190 | ^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], | |
31191 | threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@}, | |
31192 | @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},..] | |
31193 | -list-thread-groups --available --recurse 1 17 18 | |
31194 | ^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], | |
31195 | threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@}, | |
31196 | @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},...] | |
c3b108f7 | 31197 | @end smallexample |
c6ebd6cf | 31198 | |
f3e0e960 SS |
31199 | @subheading The @code{-info-os} Command |
31200 | @findex -info-os | |
31201 | ||
31202 | @subsubheading Synopsis | |
31203 | ||
31204 | @smallexample | |
31205 | -info-os [ @var{type} ] | |
31206 | @end smallexample | |
31207 | ||
31208 | If no argument is supplied, the command returns a table of available | |
31209 | operating-system-specific information types. If one of these types is | |
31210 | supplied as an argument @var{type}, then the command returns a table | |
31211 | of data of that type. | |
31212 | ||
31213 | The types of information available depend on the target operating | |
31214 | system. | |
31215 | ||
31216 | @subsubheading @value{GDBN} Command | |
31217 | ||
31218 | The corresponding @value{GDBN} command is @samp{info os}. | |
31219 | ||
31220 | @subsubheading Example | |
31221 | ||
31222 | When run on a @sc{gnu}/Linux system, the output will look something | |
31223 | like this: | |
31224 | ||
31225 | @smallexample | |
31226 | @value{GDBP} | |
31227 | -info-os | |
71caed83 | 31228 | ^done,OSDataTable=@{nr_rows="9",nr_cols="3", |
f3e0e960 | 31229 | hdr=[@{width="10",alignment="-1",col_name="col0",colhdr="Type"@}, |
71caed83 SS |
31230 | @{width="10",alignment="-1",col_name="col1",colhdr="Description"@}, |
31231 | @{width="10",alignment="-1",col_name="col2",colhdr="Title"@}], | |
31232 | body=[item=@{col0="processes",col1="Listing of all processes", | |
31233 | col2="Processes"@}, | |
31234 | item=@{col0="procgroups",col1="Listing of all process groups", | |
31235 | col2="Process groups"@}, | |
31236 | item=@{col0="threads",col1="Listing of all threads", | |
31237 | col2="Threads"@}, | |
31238 | item=@{col0="files",col1="Listing of all file descriptors", | |
31239 | col2="File descriptors"@}, | |
31240 | item=@{col0="sockets",col1="Listing of all internet-domain sockets", | |
31241 | col2="Sockets"@}, | |
31242 | item=@{col0="shm",col1="Listing of all shared-memory regions", | |
31243 | col2="Shared-memory regions"@}, | |
31244 | item=@{col0="semaphores",col1="Listing of all semaphores", | |
31245 | col2="Semaphores"@}, | |
31246 | item=@{col0="msg",col1="Listing of all message queues", | |
31247 | col2="Message queues"@}, | |
31248 | item=@{col0="modules",col1="Listing of all loaded kernel modules", | |
31249 | col2="Kernel modules"@}]@} | |
f3e0e960 SS |
31250 | @value{GDBP} |
31251 | -info-os processes | |
31252 | ^done,OSDataTable=@{nr_rows="190",nr_cols="4", | |
31253 | hdr=[@{width="10",alignment="-1",col_name="col0",colhdr="pid"@}, | |
31254 | @{width="10",alignment="-1",col_name="col1",colhdr="user"@}, | |
31255 | @{width="10",alignment="-1",col_name="col2",colhdr="command"@}, | |
31256 | @{width="10",alignment="-1",col_name="col3",colhdr="cores"@}], | |
31257 | body=[item=@{col0="1",col1="root",col2="/sbin/init",col3="0"@}, | |
31258 | item=@{col0="2",col1="root",col2="[kthreadd]",col3="1"@}, | |
31259 | item=@{col0="3",col1="root",col2="[ksoftirqd/0]",col3="0"@}, | |
31260 | ... | |
31261 | item=@{col0="26446",col1="stan",col2="bash",col3="0"@}, | |
31262 | item=@{col0="28152",col1="stan",col2="bash",col3="1"@}]@} | |
31263 | (gdb) | |
31264 | @end smallexample | |
a79b8f6e | 31265 | |
71caed83 SS |
31266 | (Note that the MI output here includes a @code{"Title"} column that |
31267 | does not appear in command-line @code{info os}; this column is useful | |
31268 | for MI clients that want to enumerate the types of data, such as in a | |
31269 | popup menu, but is needless clutter on the command line, and | |
31270 | @code{info os} omits it.) | |
31271 | ||
a79b8f6e VP |
31272 | @subheading The @code{-add-inferior} Command |
31273 | @findex -add-inferior | |
31274 | ||
31275 | @subheading Synopsis | |
31276 | ||
31277 | @smallexample | |
31278 | -add-inferior | |
31279 | @end smallexample | |
31280 | ||
31281 | Creates a new inferior (@pxref{Inferiors and Programs}). The created | |
31282 | inferior is not associated with any executable. Such association may | |
31283 | be established with the @samp{-file-exec-and-symbols} command | |
31284 | (@pxref{GDB/MI File Commands}). The command response has a single | |
b7742092 | 31285 | field, @samp{inferior}, whose value is the identifier of the |
a79b8f6e VP |
31286 | thread group corresponding to the new inferior. |
31287 | ||
31288 | @subheading Example | |
31289 | ||
31290 | @smallexample | |
31291 | @value{GDBP} | |
31292 | -add-inferior | |
b7742092 | 31293 | ^done,inferior="i3" |
a79b8f6e VP |
31294 | @end smallexample |
31295 | ||
ef21caaf NR |
31296 | @subheading The @code{-interpreter-exec} Command |
31297 | @findex -interpreter-exec | |
31298 | ||
31299 | @subheading Synopsis | |
31300 | ||
31301 | @smallexample | |
31302 | -interpreter-exec @var{interpreter} @var{command} | |
31303 | @end smallexample | |
a2c02241 | 31304 | @anchor{-interpreter-exec} |
ef21caaf NR |
31305 | |
31306 | Execute the specified @var{command} in the given @var{interpreter}. | |
31307 | ||
31308 | @subheading @value{GDBN} Command | |
31309 | ||
31310 | The corresponding @value{GDBN} command is @samp{interpreter-exec}. | |
31311 | ||
31312 | @subheading Example | |
31313 | ||
31314 | @smallexample | |
594fe323 | 31315 | (gdb) |
ef21caaf NR |
31316 | -interpreter-exec console "break main" |
31317 | &"During symbol reading, couldn't parse type; debugger out of date?.\n" | |
31318 | &"During symbol reading, bad structure-type format.\n" | |
31319 | ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n" | |
31320 | ^done | |
594fe323 | 31321 | (gdb) |
ef21caaf NR |
31322 | @end smallexample |
31323 | ||
31324 | @subheading The @code{-inferior-tty-set} Command | |
31325 | @findex -inferior-tty-set | |
31326 | ||
31327 | @subheading Synopsis | |
31328 | ||
31329 | @smallexample | |
31330 | -inferior-tty-set /dev/pts/1 | |
31331 | @end smallexample | |
31332 | ||
31333 | Set terminal for future runs of the program being debugged. | |
31334 | ||
31335 | @subheading @value{GDBN} Command | |
31336 | ||
31337 | The corresponding @value{GDBN} command is @samp{set inferior-tty} /dev/pts/1. | |
31338 | ||
31339 | @subheading Example | |
31340 | ||
31341 | @smallexample | |
594fe323 | 31342 | (gdb) |
ef21caaf NR |
31343 | -inferior-tty-set /dev/pts/1 |
31344 | ^done | |
594fe323 | 31345 | (gdb) |
ef21caaf NR |
31346 | @end smallexample |
31347 | ||
31348 | @subheading The @code{-inferior-tty-show} Command | |
31349 | @findex -inferior-tty-show | |
31350 | ||
31351 | @subheading Synopsis | |
31352 | ||
31353 | @smallexample | |
31354 | -inferior-tty-show | |
31355 | @end smallexample | |
31356 | ||
31357 | Show terminal for future runs of program being debugged. | |
31358 | ||
31359 | @subheading @value{GDBN} Command | |
31360 | ||
31361 | The corresponding @value{GDBN} command is @samp{show inferior-tty}. | |
31362 | ||
31363 | @subheading Example | |
31364 | ||
31365 | @smallexample | |
594fe323 | 31366 | (gdb) |
ef21caaf NR |
31367 | -inferior-tty-set /dev/pts/1 |
31368 | ^done | |
594fe323 | 31369 | (gdb) |
ef21caaf NR |
31370 | -inferior-tty-show |
31371 | ^done,inferior_tty_terminal="/dev/pts/1" | |
594fe323 | 31372 | (gdb) |
ef21caaf | 31373 | @end smallexample |
922fbb7b | 31374 | |
a4eefcd8 NR |
31375 | @subheading The @code{-enable-timings} Command |
31376 | @findex -enable-timings | |
31377 | ||
31378 | @subheading Synopsis | |
31379 | ||
31380 | @smallexample | |
31381 | -enable-timings [yes | no] | |
31382 | @end smallexample | |
31383 | ||
31384 | Toggle the printing of the wallclock, user and system times for an MI | |
31385 | command as a field in its output. This command is to help frontend | |
31386 | developers optimize the performance of their code. No argument is | |
31387 | equivalent to @samp{yes}. | |
31388 | ||
31389 | @subheading @value{GDBN} Command | |
31390 | ||
31391 | No equivalent. | |
31392 | ||
31393 | @subheading Example | |
31394 | ||
31395 | @smallexample | |
31396 | (gdb) | |
31397 | -enable-timings | |
31398 | ^done | |
31399 | (gdb) | |
31400 | -break-insert main | |
31401 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
31402 | addr="0x080484ed",func="main",file="myprog.c", | |
998580f1 MK |
31403 | fullname="/home/nickrob/myprog.c",line="73",thread-groups=["i1"], |
31404 | times="0"@}, | |
a4eefcd8 NR |
31405 | time=@{wallclock="0.05185",user="0.00800",system="0.00000"@} |
31406 | (gdb) | |
31407 | -enable-timings no | |
31408 | ^done | |
31409 | (gdb) | |
31410 | -exec-run | |
31411 | ^running | |
31412 | (gdb) | |
a47ec5fe | 31413 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", |
a4eefcd8 NR |
31414 | frame=@{addr="0x080484ed",func="main",args=[@{name="argc",value="1"@}, |
31415 | @{name="argv",value="0xbfb60364"@}],file="myprog.c", | |
31416 | fullname="/home/nickrob/myprog.c",line="73"@} | |
31417 | (gdb) | |
31418 | @end smallexample | |
31419 | ||
922fbb7b AC |
31420 | @node Annotations |
31421 | @chapter @value{GDBN} Annotations | |
31422 | ||
086432e2 AC |
31423 | This chapter describes annotations in @value{GDBN}. Annotations were |
31424 | designed to interface @value{GDBN} to graphical user interfaces or other | |
31425 | similar programs which want to interact with @value{GDBN} at a | |
922fbb7b AC |
31426 | relatively high level. |
31427 | ||
d3e8051b | 31428 | The annotation mechanism has largely been superseded by @sc{gdb/mi} |
086432e2 AC |
31429 | (@pxref{GDB/MI}). |
31430 | ||
922fbb7b AC |
31431 | @ignore |
31432 | This is Edition @value{EDITION}, @value{DATE}. | |
31433 | @end ignore | |
31434 | ||
31435 | @menu | |
31436 | * Annotations Overview:: What annotations are; the general syntax. | |
9e6c4bd5 | 31437 | * Server Prefix:: Issuing a command without affecting user state. |
922fbb7b AC |
31438 | * Prompting:: Annotations marking @value{GDBN}'s need for input. |
31439 | * Errors:: Annotations for error messages. | |
922fbb7b AC |
31440 | * Invalidation:: Some annotations describe things now invalid. |
31441 | * Annotations for Running:: | |
31442 | Whether the program is running, how it stopped, etc. | |
31443 | * Source Annotations:: Annotations describing source code. | |
922fbb7b AC |
31444 | @end menu |
31445 | ||
31446 | @node Annotations Overview | |
31447 | @section What is an Annotation? | |
31448 | @cindex annotations | |
31449 | ||
922fbb7b AC |
31450 | Annotations start with a newline character, two @samp{control-z} |
31451 | characters, and the name of the annotation. If there is no additional | |
31452 | information associated with this annotation, the name of the annotation | |
31453 | is followed immediately by a newline. If there is additional | |
31454 | information, the name of the annotation is followed by a space, the | |
31455 | additional information, and a newline. The additional information | |
31456 | cannot contain newline characters. | |
31457 | ||
31458 | Any output not beginning with a newline and two @samp{control-z} | |
31459 | characters denotes literal output from @value{GDBN}. Currently there is | |
31460 | no need for @value{GDBN} to output a newline followed by two | |
31461 | @samp{control-z} characters, but if there was such a need, the | |
31462 | annotations could be extended with an @samp{escape} annotation which | |
31463 | means those three characters as output. | |
31464 | ||
086432e2 AC |
31465 | The annotation @var{level}, which is specified using the |
31466 | @option{--annotate} command line option (@pxref{Mode Options}), controls | |
31467 | how much information @value{GDBN} prints together with its prompt, | |
31468 | values of expressions, source lines, and other types of output. Level 0 | |
d3e8051b | 31469 | is for no annotations, level 1 is for use when @value{GDBN} is run as a |
086432e2 AC |
31470 | subprocess of @sc{gnu} Emacs, level 3 is the maximum annotation suitable |
31471 | for programs that control @value{GDBN}, and level 2 annotations have | |
31472 | been made obsolete (@pxref{Limitations, , Limitations of the Annotation | |
09d4efe1 EZ |
31473 | Interface, annotate, GDB's Obsolete Annotations}). |
31474 | ||
31475 | @table @code | |
31476 | @kindex set annotate | |
31477 | @item set annotate @var{level} | |
e09f16f9 | 31478 | The @value{GDBN} command @code{set annotate} sets the level of |
09d4efe1 | 31479 | annotations to the specified @var{level}. |
9c16f35a EZ |
31480 | |
31481 | @item show annotate | |
31482 | @kindex show annotate | |
31483 | Show the current annotation level. | |
09d4efe1 EZ |
31484 | @end table |
31485 | ||
31486 | This chapter describes level 3 annotations. | |
086432e2 | 31487 | |
922fbb7b AC |
31488 | A simple example of starting up @value{GDBN} with annotations is: |
31489 | ||
31490 | @smallexample | |
086432e2 AC |
31491 | $ @kbd{gdb --annotate=3} |
31492 | GNU gdb 6.0 | |
31493 | Copyright 2003 Free Software Foundation, Inc. | |
922fbb7b AC |
31494 | GDB is free software, covered by the GNU General Public License, |
31495 | and you are welcome to change it and/or distribute copies of it | |
31496 | under certain conditions. | |
31497 | Type "show copying" to see the conditions. | |
31498 | There is absolutely no warranty for GDB. Type "show warranty" | |
31499 | for details. | |
086432e2 | 31500 | This GDB was configured as "i386-pc-linux-gnu" |
922fbb7b AC |
31501 | |
31502 | ^Z^Zpre-prompt | |
f7dc1244 | 31503 | (@value{GDBP}) |
922fbb7b | 31504 | ^Z^Zprompt |
086432e2 | 31505 | @kbd{quit} |
922fbb7b AC |
31506 | |
31507 | ^Z^Zpost-prompt | |
b383017d | 31508 | $ |
922fbb7b AC |
31509 | @end smallexample |
31510 | ||
31511 | Here @samp{quit} is input to @value{GDBN}; the rest is output from | |
31512 | @value{GDBN}. The three lines beginning @samp{^Z^Z} (where @samp{^Z} | |
31513 | denotes a @samp{control-z} character) are annotations; the rest is | |
31514 | output from @value{GDBN}. | |
31515 | ||
9e6c4bd5 NR |
31516 | @node Server Prefix |
31517 | @section The Server Prefix | |
31518 | @cindex server prefix | |
31519 | ||
31520 | If you prefix a command with @samp{server } then it will not affect | |
31521 | the command history, nor will it affect @value{GDBN}'s notion of which | |
31522 | command to repeat if @key{RET} is pressed on a line by itself. This | |
31523 | means that commands can be run behind a user's back by a front-end in | |
31524 | a transparent manner. | |
31525 | ||
d837706a NR |
31526 | The @code{server } prefix does not affect the recording of values into |
31527 | the value history; to print a value without recording it into the | |
31528 | value history, use the @code{output} command instead of the | |
31529 | @code{print} command. | |
31530 | ||
31531 | Using this prefix also disables confirmation requests | |
31532 | (@pxref{confirmation requests}). | |
9e6c4bd5 | 31533 | |
922fbb7b AC |
31534 | @node Prompting |
31535 | @section Annotation for @value{GDBN} Input | |
31536 | ||
31537 | @cindex annotations for prompts | |
31538 | When @value{GDBN} prompts for input, it annotates this fact so it is possible | |
31539 | to know when to send output, when the output from a given command is | |
31540 | over, etc. | |
31541 | ||
31542 | Different kinds of input each have a different @dfn{input type}. Each | |
31543 | input type has three annotations: a @code{pre-} annotation, which | |
31544 | denotes the beginning of any prompt which is being output, a plain | |
31545 | annotation, which denotes the end of the prompt, and then a @code{post-} | |
31546 | annotation which denotes the end of any echo which may (or may not) be | |
31547 | associated with the input. For example, the @code{prompt} input type | |
31548 | features the following annotations: | |
31549 | ||
31550 | @smallexample | |
31551 | ^Z^Zpre-prompt | |
31552 | ^Z^Zprompt | |
31553 | ^Z^Zpost-prompt | |
31554 | @end smallexample | |
31555 | ||
31556 | The input types are | |
31557 | ||
31558 | @table @code | |
e5ac9b53 EZ |
31559 | @findex pre-prompt annotation |
31560 | @findex prompt annotation | |
31561 | @findex post-prompt annotation | |
922fbb7b AC |
31562 | @item prompt |
31563 | When @value{GDBN} is prompting for a command (the main @value{GDBN} prompt). | |
31564 | ||
e5ac9b53 EZ |
31565 | @findex pre-commands annotation |
31566 | @findex commands annotation | |
31567 | @findex post-commands annotation | |
922fbb7b AC |
31568 | @item commands |
31569 | When @value{GDBN} prompts for a set of commands, like in the @code{commands} | |
31570 | command. The annotations are repeated for each command which is input. | |
31571 | ||
e5ac9b53 EZ |
31572 | @findex pre-overload-choice annotation |
31573 | @findex overload-choice annotation | |
31574 | @findex post-overload-choice annotation | |
922fbb7b AC |
31575 | @item overload-choice |
31576 | When @value{GDBN} wants the user to select between various overloaded functions. | |
31577 | ||
e5ac9b53 EZ |
31578 | @findex pre-query annotation |
31579 | @findex query annotation | |
31580 | @findex post-query annotation | |
922fbb7b AC |
31581 | @item query |
31582 | When @value{GDBN} wants the user to confirm a potentially dangerous operation. | |
31583 | ||
e5ac9b53 EZ |
31584 | @findex pre-prompt-for-continue annotation |
31585 | @findex prompt-for-continue annotation | |
31586 | @findex post-prompt-for-continue annotation | |
922fbb7b AC |
31587 | @item prompt-for-continue |
31588 | When @value{GDBN} is asking the user to press return to continue. Note: Don't | |
31589 | expect this to work well; instead use @code{set height 0} to disable | |
31590 | prompting. This is because the counting of lines is buggy in the | |
31591 | presence of annotations. | |
31592 | @end table | |
31593 | ||
31594 | @node Errors | |
31595 | @section Errors | |
31596 | @cindex annotations for errors, warnings and interrupts | |
31597 | ||
e5ac9b53 | 31598 | @findex quit annotation |
922fbb7b AC |
31599 | @smallexample |
31600 | ^Z^Zquit | |
31601 | @end smallexample | |
31602 | ||
31603 | This annotation occurs right before @value{GDBN} responds to an interrupt. | |
31604 | ||
e5ac9b53 | 31605 | @findex error annotation |
922fbb7b AC |
31606 | @smallexample |
31607 | ^Z^Zerror | |
31608 | @end smallexample | |
31609 | ||
31610 | This annotation occurs right before @value{GDBN} responds to an error. | |
31611 | ||
31612 | Quit and error annotations indicate that any annotations which @value{GDBN} was | |
31613 | in the middle of may end abruptly. For example, if a | |
31614 | @code{value-history-begin} annotation is followed by a @code{error}, one | |
31615 | cannot expect to receive the matching @code{value-history-end}. One | |
31616 | cannot expect not to receive it either, however; an error annotation | |
31617 | does not necessarily mean that @value{GDBN} is immediately returning all the way | |
31618 | to the top level. | |
31619 | ||
e5ac9b53 | 31620 | @findex error-begin annotation |
922fbb7b AC |
31621 | A quit or error annotation may be preceded by |
31622 | ||
31623 | @smallexample | |
31624 | ^Z^Zerror-begin | |
31625 | @end smallexample | |
31626 | ||
31627 | Any output between that and the quit or error annotation is the error | |
31628 | message. | |
31629 | ||
31630 | Warning messages are not yet annotated. | |
31631 | @c If we want to change that, need to fix warning(), type_error(), | |
31632 | @c range_error(), and possibly other places. | |
31633 | ||
922fbb7b AC |
31634 | @node Invalidation |
31635 | @section Invalidation Notices | |
31636 | ||
31637 | @cindex annotations for invalidation messages | |
31638 | The following annotations say that certain pieces of state may have | |
31639 | changed. | |
31640 | ||
31641 | @table @code | |
e5ac9b53 | 31642 | @findex frames-invalid annotation |
922fbb7b AC |
31643 | @item ^Z^Zframes-invalid |
31644 | ||
31645 | The frames (for example, output from the @code{backtrace} command) may | |
31646 | have changed. | |
31647 | ||
e5ac9b53 | 31648 | @findex breakpoints-invalid annotation |
922fbb7b AC |
31649 | @item ^Z^Zbreakpoints-invalid |
31650 | ||
31651 | The breakpoints may have changed. For example, the user just added or | |
31652 | deleted a breakpoint. | |
31653 | @end table | |
31654 | ||
31655 | @node Annotations for Running | |
31656 | @section Running the Program | |
31657 | @cindex annotations for running programs | |
31658 | ||
e5ac9b53 EZ |
31659 | @findex starting annotation |
31660 | @findex stopping annotation | |
922fbb7b | 31661 | When the program starts executing due to a @value{GDBN} command such as |
b383017d | 31662 | @code{step} or @code{continue}, |
922fbb7b AC |
31663 | |
31664 | @smallexample | |
31665 | ^Z^Zstarting | |
31666 | @end smallexample | |
31667 | ||
b383017d | 31668 | is output. When the program stops, |
922fbb7b AC |
31669 | |
31670 | @smallexample | |
31671 | ^Z^Zstopped | |
31672 | @end smallexample | |
31673 | ||
31674 | is output. Before the @code{stopped} annotation, a variety of | |
31675 | annotations describe how the program stopped. | |
31676 | ||
31677 | @table @code | |
e5ac9b53 | 31678 | @findex exited annotation |
922fbb7b AC |
31679 | @item ^Z^Zexited @var{exit-status} |
31680 | The program exited, and @var{exit-status} is the exit status (zero for | |
31681 | successful exit, otherwise nonzero). | |
31682 | ||
e5ac9b53 EZ |
31683 | @findex signalled annotation |
31684 | @findex signal-name annotation | |
31685 | @findex signal-name-end annotation | |
31686 | @findex signal-string annotation | |
31687 | @findex signal-string-end annotation | |
922fbb7b AC |
31688 | @item ^Z^Zsignalled |
31689 | The program exited with a signal. After the @code{^Z^Zsignalled}, the | |
31690 | annotation continues: | |
31691 | ||
31692 | @smallexample | |
31693 | @var{intro-text} | |
31694 | ^Z^Zsignal-name | |
31695 | @var{name} | |
31696 | ^Z^Zsignal-name-end | |
31697 | @var{middle-text} | |
31698 | ^Z^Zsignal-string | |
31699 | @var{string} | |
31700 | ^Z^Zsignal-string-end | |
31701 | @var{end-text} | |
31702 | @end smallexample | |
31703 | ||
31704 | @noindent | |
31705 | where @var{name} is the name of the signal, such as @code{SIGILL} or | |
31706 | @code{SIGSEGV}, and @var{string} is the explanation of the signal, such | |
697aa1b7 | 31707 | as @code{Illegal Instruction} or @code{Segmentation fault}. The arguments |
922fbb7b AC |
31708 | @var{intro-text}, @var{middle-text}, and @var{end-text} are for the |
31709 | user's benefit and have no particular format. | |
31710 | ||
e5ac9b53 | 31711 | @findex signal annotation |
922fbb7b AC |
31712 | @item ^Z^Zsignal |
31713 | The syntax of this annotation is just like @code{signalled}, but @value{GDBN} is | |
31714 | just saying that the program received the signal, not that it was | |
31715 | terminated with it. | |
31716 | ||
e5ac9b53 | 31717 | @findex breakpoint annotation |
922fbb7b AC |
31718 | @item ^Z^Zbreakpoint @var{number} |
31719 | The program hit breakpoint number @var{number}. | |
31720 | ||
e5ac9b53 | 31721 | @findex watchpoint annotation |
922fbb7b AC |
31722 | @item ^Z^Zwatchpoint @var{number} |
31723 | The program hit watchpoint number @var{number}. | |
31724 | @end table | |
31725 | ||
31726 | @node Source Annotations | |
31727 | @section Displaying Source | |
31728 | @cindex annotations for source display | |
31729 | ||
e5ac9b53 | 31730 | @findex source annotation |
922fbb7b AC |
31731 | The following annotation is used instead of displaying source code: |
31732 | ||
31733 | @smallexample | |
31734 | ^Z^Zsource @var{filename}:@var{line}:@var{character}:@var{middle}:@var{addr} | |
31735 | @end smallexample | |
31736 | ||
31737 | where @var{filename} is an absolute file name indicating which source | |
31738 | file, @var{line} is the line number within that file (where 1 is the | |
31739 | first line in the file), @var{character} is the character position | |
31740 | within the file (where 0 is the first character in the file) (for most | |
31741 | debug formats this will necessarily point to the beginning of a line), | |
31742 | @var{middle} is @samp{middle} if @var{addr} is in the middle of the | |
31743 | line, or @samp{beg} if @var{addr} is at the beginning of the line, and | |
31744 | @var{addr} is the address in the target program associated with the | |
697aa1b7 | 31745 | source which is being displayed. The @var{addr} is in the form @samp{0x} |
922fbb7b AC |
31746 | followed by one or more lowercase hex digits (note that this does not |
31747 | depend on the language). | |
31748 | ||
4efc6507 DE |
31749 | @node JIT Interface |
31750 | @chapter JIT Compilation Interface | |
31751 | @cindex just-in-time compilation | |
31752 | @cindex JIT compilation interface | |
31753 | ||
31754 | This chapter documents @value{GDBN}'s @dfn{just-in-time} (JIT) compilation | |
31755 | interface. A JIT compiler is a program or library that generates native | |
31756 | executable code at runtime and executes it, usually in order to achieve good | |
31757 | performance while maintaining platform independence. | |
31758 | ||
31759 | Programs that use JIT compilation are normally difficult to debug because | |
31760 | portions of their code are generated at runtime, instead of being loaded from | |
31761 | object files, which is where @value{GDBN} normally finds the program's symbols | |
31762 | and debug information. In order to debug programs that use JIT compilation, | |
31763 | @value{GDBN} has an interface that allows the program to register in-memory | |
31764 | symbol files with @value{GDBN} at runtime. | |
31765 | ||
31766 | If you are using @value{GDBN} to debug a program that uses this interface, then | |
31767 | it should work transparently so long as you have not stripped the binary. If | |
31768 | you are developing a JIT compiler, then the interface is documented in the rest | |
31769 | of this chapter. At this time, the only known client of this interface is the | |
31770 | LLVM JIT. | |
31771 | ||
31772 | Broadly speaking, the JIT interface mirrors the dynamic loader interface. The | |
31773 | JIT compiler communicates with @value{GDBN} by writing data into a global | |
31774 | variable and calling a fuction at a well-known symbol. When @value{GDBN} | |
31775 | attaches, it reads a linked list of symbol files from the global variable to | |
31776 | find existing code, and puts a breakpoint in the function so that it can find | |
31777 | out about additional code. | |
31778 | ||
31779 | @menu | |
31780 | * Declarations:: Relevant C struct declarations | |
31781 | * Registering Code:: Steps to register code | |
31782 | * Unregistering Code:: Steps to unregister code | |
f85b53f8 | 31783 | * Custom Debug Info:: Emit debug information in a custom format |
4efc6507 DE |
31784 | @end menu |
31785 | ||
31786 | @node Declarations | |
31787 | @section JIT Declarations | |
31788 | ||
31789 | These are the relevant struct declarations that a C program should include to | |
31790 | implement the interface: | |
31791 | ||
31792 | @smallexample | |
31793 | typedef enum | |
31794 | @{ | |
31795 | JIT_NOACTION = 0, | |
31796 | JIT_REGISTER_FN, | |
31797 | JIT_UNREGISTER_FN | |
31798 | @} jit_actions_t; | |
31799 | ||
31800 | struct jit_code_entry | |
31801 | @{ | |
31802 | struct jit_code_entry *next_entry; | |
31803 | struct jit_code_entry *prev_entry; | |
31804 | const char *symfile_addr; | |
31805 | uint64_t symfile_size; | |
31806 | @}; | |
31807 | ||
31808 | struct jit_descriptor | |
31809 | @{ | |
31810 | uint32_t version; | |
31811 | /* This type should be jit_actions_t, but we use uint32_t | |
31812 | to be explicit about the bitwidth. */ | |
31813 | uint32_t action_flag; | |
31814 | struct jit_code_entry *relevant_entry; | |
31815 | struct jit_code_entry *first_entry; | |
31816 | @}; | |
31817 | ||
31818 | /* GDB puts a breakpoint in this function. */ | |
31819 | void __attribute__((noinline)) __jit_debug_register_code() @{ @}; | |
31820 | ||
31821 | /* Make sure to specify the version statically, because the | |
31822 | debugger may check the version before we can set it. */ | |
31823 | struct jit_descriptor __jit_debug_descriptor = @{ 1, 0, 0, 0 @}; | |
31824 | @end smallexample | |
31825 | ||
31826 | If the JIT is multi-threaded, then it is important that the JIT synchronize any | |
31827 | modifications to this global data properly, which can easily be done by putting | |
31828 | a global mutex around modifications to these structures. | |
31829 | ||
31830 | @node Registering Code | |
31831 | @section Registering Code | |
31832 | ||
31833 | To register code with @value{GDBN}, the JIT should follow this protocol: | |
31834 | ||
31835 | @itemize @bullet | |
31836 | @item | |
31837 | Generate an object file in memory with symbols and other desired debug | |
31838 | information. The file must include the virtual addresses of the sections. | |
31839 | ||
31840 | @item | |
31841 | Create a code entry for the file, which gives the start and size of the symbol | |
31842 | file. | |
31843 | ||
31844 | @item | |
31845 | Add it to the linked list in the JIT descriptor. | |
31846 | ||
31847 | @item | |
31848 | Point the relevant_entry field of the descriptor at the entry. | |
31849 | ||
31850 | @item | |
31851 | Set @code{action_flag} to @code{JIT_REGISTER} and call | |
31852 | @code{__jit_debug_register_code}. | |
31853 | @end itemize | |
31854 | ||
31855 | When @value{GDBN} is attached and the breakpoint fires, @value{GDBN} uses the | |
31856 | @code{relevant_entry} pointer so it doesn't have to walk the list looking for | |
31857 | new code. However, the linked list must still be maintained in order to allow | |
31858 | @value{GDBN} to attach to a running process and still find the symbol files. | |
31859 | ||
31860 | @node Unregistering Code | |
31861 | @section Unregistering Code | |
31862 | ||
31863 | If code is freed, then the JIT should use the following protocol: | |
31864 | ||
31865 | @itemize @bullet | |
31866 | @item | |
31867 | Remove the code entry corresponding to the code from the linked list. | |
31868 | ||
31869 | @item | |
31870 | Point the @code{relevant_entry} field of the descriptor at the code entry. | |
31871 | ||
31872 | @item | |
31873 | Set @code{action_flag} to @code{JIT_UNREGISTER} and call | |
31874 | @code{__jit_debug_register_code}. | |
31875 | @end itemize | |
31876 | ||
31877 | If the JIT frees or recompiles code without unregistering it, then @value{GDBN} | |
31878 | and the JIT will leak the memory used for the associated symbol files. | |
31879 | ||
f85b53f8 SD |
31880 | @node Custom Debug Info |
31881 | @section Custom Debug Info | |
31882 | @cindex custom JIT debug info | |
31883 | @cindex JIT debug info reader | |
31884 | ||
31885 | Generating debug information in platform-native file formats (like ELF | |
31886 | or COFF) may be an overkill for JIT compilers; especially if all the | |
31887 | debug info is used for is displaying a meaningful backtrace. The | |
31888 | issue can be resolved by having the JIT writers decide on a debug info | |
31889 | format and also provide a reader that parses the debug info generated | |
31890 | by the JIT compiler. This section gives a brief overview on writing | |
31891 | such a parser. More specific details can be found in the source file | |
31892 | @file{gdb/jit-reader.in}, which is also installed as a header at | |
31893 | @file{@var{includedir}/gdb/jit-reader.h} for easy inclusion. | |
31894 | ||
31895 | The reader is implemented as a shared object (so this functionality is | |
31896 | not available on platforms which don't allow loading shared objects at | |
31897 | runtime). Two @value{GDBN} commands, @code{jit-reader-load} and | |
31898 | @code{jit-reader-unload} are provided, to be used to load and unload | |
31899 | the readers from a preconfigured directory. Once loaded, the shared | |
31900 | object is used the parse the debug information emitted by the JIT | |
31901 | compiler. | |
31902 | ||
31903 | @menu | |
31904 | * Using JIT Debug Info Readers:: How to use supplied readers correctly | |
31905 | * Writing JIT Debug Info Readers:: Creating a debug-info reader | |
31906 | @end menu | |
31907 | ||
31908 | @node Using JIT Debug Info Readers | |
31909 | @subsection Using JIT Debug Info Readers | |
31910 | @kindex jit-reader-load | |
31911 | @kindex jit-reader-unload | |
31912 | ||
31913 | Readers can be loaded and unloaded using the @code{jit-reader-load} | |
31914 | and @code{jit-reader-unload} commands. | |
31915 | ||
31916 | @table @code | |
c9fb1240 | 31917 | @item jit-reader-load @var{reader} |
697aa1b7 | 31918 | Load the JIT reader named @var{reader}, which is a shared |
c9fb1240 SD |
31919 | object specified as either an absolute or a relative file name. In |
31920 | the latter case, @value{GDBN} will try to load the reader from a | |
31921 | pre-configured directory, usually @file{@var{libdir}/gdb/} on a UNIX | |
31922 | system (here @var{libdir} is the system library directory, often | |
31923 | @file{/usr/local/lib}). | |
31924 | ||
31925 | Only one reader can be active at a time; trying to load a second | |
31926 | reader when one is already loaded will result in @value{GDBN} | |
31927 | reporting an error. A new JIT reader can be loaded by first unloading | |
31928 | the current one using @code{jit-reader-unload} and then invoking | |
31929 | @code{jit-reader-load}. | |
f85b53f8 SD |
31930 | |
31931 | @item jit-reader-unload | |
31932 | Unload the currently loaded JIT reader. | |
31933 | ||
31934 | @end table | |
31935 | ||
31936 | @node Writing JIT Debug Info Readers | |
31937 | @subsection Writing JIT Debug Info Readers | |
31938 | @cindex writing JIT debug info readers | |
31939 | ||
31940 | As mentioned, a reader is essentially a shared object conforming to a | |
31941 | certain ABI. This ABI is described in @file{jit-reader.h}. | |
31942 | ||
31943 | @file{jit-reader.h} defines the structures, macros and functions | |
31944 | required to write a reader. It is installed (along with | |
31945 | @value{GDBN}), in @file{@var{includedir}/gdb} where @var{includedir} is | |
31946 | the system include directory. | |
31947 | ||
31948 | Readers need to be released under a GPL compatible license. A reader | |
31949 | can be declared as released under such a license by placing the macro | |
31950 | @code{GDB_DECLARE_GPL_COMPATIBLE_READER} in a source file. | |
31951 | ||
31952 | The entry point for readers is the symbol @code{gdb_init_reader}, | |
31953 | which is expected to be a function with the prototype | |
31954 | ||
31955 | @findex gdb_init_reader | |
31956 | @smallexample | |
31957 | extern struct gdb_reader_funcs *gdb_init_reader (void); | |
31958 | @end smallexample | |
31959 | ||
31960 | @cindex @code{struct gdb_reader_funcs} | |
31961 | ||
31962 | @code{struct gdb_reader_funcs} contains a set of pointers to callback | |
31963 | functions. These functions are executed to read the debug info | |
31964 | generated by the JIT compiler (@code{read}), to unwind stack frames | |
31965 | (@code{unwind}) and to create canonical frame IDs | |
31966 | (@code{get_Frame_id}). It also has a callback that is called when the | |
31967 | reader is being unloaded (@code{destroy}). The struct looks like this | |
31968 | ||
31969 | @smallexample | |
31970 | struct gdb_reader_funcs | |
31971 | @{ | |
31972 | /* Must be set to GDB_READER_INTERFACE_VERSION. */ | |
31973 | int reader_version; | |
31974 | ||
31975 | /* For use by the reader. */ | |
31976 | void *priv_data; | |
31977 | ||
31978 | gdb_read_debug_info *read; | |
31979 | gdb_unwind_frame *unwind; | |
31980 | gdb_get_frame_id *get_frame_id; | |
31981 | gdb_destroy_reader *destroy; | |
31982 | @}; | |
31983 | @end smallexample | |
31984 | ||
31985 | @cindex @code{struct gdb_symbol_callbacks} | |
31986 | @cindex @code{struct gdb_unwind_callbacks} | |
31987 | ||
31988 | The callbacks are provided with another set of callbacks by | |
31989 | @value{GDBN} to do their job. For @code{read}, these callbacks are | |
31990 | passed in a @code{struct gdb_symbol_callbacks} and for @code{unwind} | |
31991 | and @code{get_frame_id}, in a @code{struct gdb_unwind_callbacks}. | |
31992 | @code{struct gdb_symbol_callbacks} has callbacks to create new object | |
31993 | files and new symbol tables inside those object files. @code{struct | |
31994 | gdb_unwind_callbacks} has callbacks to read registers off the current | |
31995 | frame and to write out the values of the registers in the previous | |
31996 | frame. Both have a callback (@code{target_read}) to read bytes off the | |
31997 | target's address space. | |
31998 | ||
d1feda86 YQ |
31999 | @node In-Process Agent |
32000 | @chapter In-Process Agent | |
32001 | @cindex debugging agent | |
32002 | The traditional debugging model is conceptually low-speed, but works fine, | |
32003 | because most bugs can be reproduced in debugging-mode execution. However, | |
32004 | as multi-core or many-core processors are becoming mainstream, and | |
32005 | multi-threaded programs become more and more popular, there should be more | |
32006 | and more bugs that only manifest themselves at normal-mode execution, for | |
32007 | example, thread races, because debugger's interference with the program's | |
32008 | timing may conceal the bugs. On the other hand, in some applications, | |
32009 | it is not feasible for the debugger to interrupt the program's execution | |
32010 | long enough for the developer to learn anything helpful about its behavior. | |
32011 | If the program's correctness depends on its real-time behavior, delays | |
32012 | introduced by a debugger might cause the program to fail, even when the | |
32013 | code itself is correct. It is useful to be able to observe the program's | |
32014 | behavior without interrupting it. | |
32015 | ||
32016 | Therefore, traditional debugging model is too intrusive to reproduce | |
32017 | some bugs. In order to reduce the interference with the program, we can | |
32018 | reduce the number of operations performed by debugger. The | |
32019 | @dfn{In-Process Agent}, a shared library, is running within the same | |
32020 | process with inferior, and is able to perform some debugging operations | |
32021 | itself. As a result, debugger is only involved when necessary, and | |
32022 | performance of debugging can be improved accordingly. Note that | |
32023 | interference with program can be reduced but can't be removed completely, | |
32024 | because the in-process agent will still stop or slow down the program. | |
32025 | ||
32026 | The in-process agent can interpret and execute Agent Expressions | |
32027 | (@pxref{Agent Expressions}) during performing debugging operations. The | |
32028 | agent expressions can be used for different purposes, such as collecting | |
32029 | data in tracepoints, and condition evaluation in breakpoints. | |
32030 | ||
32031 | @anchor{Control Agent} | |
32032 | You can control whether the in-process agent is used as an aid for | |
32033 | debugging with the following commands: | |
32034 | ||
32035 | @table @code | |
32036 | @kindex set agent on | |
32037 | @item set agent on | |
32038 | Causes the in-process agent to perform some operations on behalf of the | |
32039 | debugger. Just which operations requested by the user will be done | |
32040 | by the in-process agent depends on the its capabilities. For example, | |
32041 | if you request to evaluate breakpoint conditions in the in-process agent, | |
32042 | and the in-process agent has such capability as well, then breakpoint | |
32043 | conditions will be evaluated in the in-process agent. | |
32044 | ||
32045 | @kindex set agent off | |
32046 | @item set agent off | |
32047 | Disables execution of debugging operations by the in-process agent. All | |
32048 | of the operations will be performed by @value{GDBN}. | |
32049 | ||
32050 | @kindex show agent | |
32051 | @item show agent | |
32052 | Display the current setting of execution of debugging operations by | |
32053 | the in-process agent. | |
32054 | @end table | |
32055 | ||
16bdd41f YQ |
32056 | @menu |
32057 | * In-Process Agent Protocol:: | |
32058 | @end menu | |
32059 | ||
32060 | @node In-Process Agent Protocol | |
32061 | @section In-Process Agent Protocol | |
32062 | @cindex in-process agent protocol | |
32063 | ||
32064 | The in-process agent is able to communicate with both @value{GDBN} and | |
32065 | GDBserver (@pxref{In-Process Agent}). This section documents the protocol | |
32066 | used for communications between @value{GDBN} or GDBserver and the IPA. | |
32067 | In general, @value{GDBN} or GDBserver sends commands | |
32068 | (@pxref{IPA Protocol Commands}) and data to in-process agent, and then | |
32069 | in-process agent replies back with the return result of the command, or | |
32070 | some other information. The data sent to in-process agent is composed | |
32071 | of primitive data types, such as 4-byte or 8-byte type, and composite | |
32072 | types, which are called objects (@pxref{IPA Protocol Objects}). | |
32073 | ||
32074 | @menu | |
32075 | * IPA Protocol Objects:: | |
32076 | * IPA Protocol Commands:: | |
32077 | @end menu | |
32078 | ||
32079 | @node IPA Protocol Objects | |
32080 | @subsection IPA Protocol Objects | |
32081 | @cindex ipa protocol objects | |
32082 | ||
32083 | The commands sent to and results received from agent may contain some | |
32084 | complex data types called @dfn{objects}. | |
32085 | ||
32086 | The in-process agent is running on the same machine with @value{GDBN} | |
32087 | or GDBserver, so it doesn't have to handle as much differences between | |
32088 | two ends as remote protocol (@pxref{Remote Protocol}) tries to handle. | |
32089 | However, there are still some differences of two ends in two processes: | |
32090 | ||
32091 | @enumerate | |
32092 | @item | |
32093 | word size. On some 64-bit machines, @value{GDBN} or GDBserver can be | |
32094 | compiled as a 64-bit executable, while in-process agent is a 32-bit one. | |
32095 | @item | |
32096 | ABI. Some machines may have multiple types of ABI, @value{GDBN} or | |
32097 | GDBserver is compiled with one, and in-process agent is compiled with | |
32098 | the other one. | |
32099 | @end enumerate | |
32100 | ||
32101 | Here are the IPA Protocol Objects: | |
32102 | ||
32103 | @enumerate | |
32104 | @item | |
32105 | agent expression object. It represents an agent expression | |
32106 | (@pxref{Agent Expressions}). | |
32107 | @anchor{agent expression object} | |
32108 | @item | |
32109 | tracepoint action object. It represents a tracepoint action | |
32110 | (@pxref{Tracepoint Actions,,Tracepoint Action Lists}) to collect registers, | |
32111 | memory, static trace data and to evaluate expression. | |
32112 | @anchor{tracepoint action object} | |
32113 | @item | |
32114 | tracepoint object. It represents a tracepoint (@pxref{Tracepoints}). | |
32115 | @anchor{tracepoint object} | |
32116 | ||
32117 | @end enumerate | |
32118 | ||
32119 | The following table describes important attributes of each IPA protocol | |
32120 | object: | |
32121 | ||
32122 | @multitable @columnfractions .30 .20 .50 | |
32123 | @headitem Name @tab Size @tab Description | |
32124 | @item @emph{agent expression object} @tab @tab | |
32125 | @item length @tab 4 @tab length of bytes code | |
32126 | @item byte code @tab @var{length} @tab contents of byte code | |
32127 | @item @emph{tracepoint action for collecting memory} @tab @tab | |
32128 | @item 'M' @tab 1 @tab type of tracepoint action | |
32129 | @item addr @tab 8 @tab if @var{basereg} is @samp{-1}, @var{addr} is the | |
32130 | address of the lowest byte to collect, otherwise @var{addr} is the offset | |
32131 | of @var{basereg} for memory collecting. | |
32132 | @item len @tab 8 @tab length of memory for collecting | |
32133 | @item basereg @tab 4 @tab the register number containing the starting | |
32134 | memory address for collecting. | |
32135 | @item @emph{tracepoint action for collecting registers} @tab @tab | |
32136 | @item 'R' @tab 1 @tab type of tracepoint action | |
32137 | @item @emph{tracepoint action for collecting static trace data} @tab @tab | |
32138 | @item 'L' @tab 1 @tab type of tracepoint action | |
32139 | @item @emph{tracepoint action for expression evaluation} @tab @tab | |
32140 | @item 'X' @tab 1 @tab type of tracepoint action | |
32141 | @item agent expression @tab length of @tab @ref{agent expression object} | |
32142 | @item @emph{tracepoint object} @tab @tab | |
32143 | @item number @tab 4 @tab number of tracepoint | |
32144 | @item address @tab 8 @tab address of tracepoint inserted on | |
32145 | @item type @tab 4 @tab type of tracepoint | |
32146 | @item enabled @tab 1 @tab enable or disable of tracepoint | |
32147 | @item step_count @tab 8 @tab step | |
32148 | @item pass_count @tab 8 @tab pass | |
32149 | @item numactions @tab 4 @tab number of tracepoint actions | |
32150 | @item hit count @tab 8 @tab hit count | |
32151 | @item trace frame usage @tab 8 @tab trace frame usage | |
32152 | @item compiled_cond @tab 8 @tab compiled condition | |
32153 | @item orig_size @tab 8 @tab orig size | |
32154 | @item condition @tab 4 if condition is NULL otherwise length of | |
32155 | @ref{agent expression object} | |
32156 | @tab zero if condition is NULL, otherwise is | |
32157 | @ref{agent expression object} | |
32158 | @item actions @tab variable | |
32159 | @tab numactions number of @ref{tracepoint action object} | |
32160 | @end multitable | |
32161 | ||
32162 | @node IPA Protocol Commands | |
32163 | @subsection IPA Protocol Commands | |
32164 | @cindex ipa protocol commands | |
32165 | ||
32166 | The spaces in each command are delimiters to ease reading this commands | |
32167 | specification. They don't exist in real commands. | |
32168 | ||
32169 | @table @samp | |
32170 | ||
32171 | @item FastTrace:@var{tracepoint_object} @var{gdb_jump_pad_head} | |
32172 | Installs a new fast tracepoint described by @var{tracepoint_object} | |
697aa1b7 | 32173 | (@pxref{tracepoint object}). The @var{gdb_jump_pad_head}, 8-byte long, is the |
16bdd41f YQ |
32174 | head of @dfn{jumppad}, which is used to jump to data collection routine |
32175 | in IPA finally. | |
32176 | ||
32177 | Replies: | |
32178 | @table @samp | |
32179 | @item OK @var{target_address} @var{gdb_jump_pad_head} @var{fjump_size} @var{fjump} | |
32180 | @var{target_address} is address of tracepoint in the inferior. | |
697aa1b7 | 32181 | The @var{gdb_jump_pad_head} is updated head of jumppad. Both of |
16bdd41f | 32182 | @var{target_address} and @var{gdb_jump_pad_head} are 8-byte long. |
697aa1b7 EZ |
32183 | The @var{fjump} contains a sequence of instructions jump to jumppad entry. |
32184 | The @var{fjump_size}, 4-byte long, is the size of @var{fjump}. | |
16bdd41f YQ |
32185 | @item E @var{NN} |
32186 | for an error | |
32187 | ||
32188 | @end table | |
32189 | ||
7255706c YQ |
32190 | @item close |
32191 | Closes the in-process agent. This command is sent when @value{GDBN} or GDBserver | |
32192 | is about to kill inferiors. | |
32193 | ||
16bdd41f YQ |
32194 | @item qTfSTM |
32195 | @xref{qTfSTM}. | |
32196 | @item qTsSTM | |
32197 | @xref{qTsSTM}. | |
32198 | @item qTSTMat | |
32199 | @xref{qTSTMat}. | |
32200 | @item probe_marker_at:@var{address} | |
32201 | Asks in-process agent to probe the marker at @var{address}. | |
32202 | ||
32203 | Replies: | |
32204 | @table @samp | |
32205 | @item E @var{NN} | |
32206 | for an error | |
32207 | @end table | |
32208 | @item unprobe_marker_at:@var{address} | |
32209 | Asks in-process agent to unprobe the marker at @var{address}. | |
32210 | @end table | |
32211 | ||
8e04817f AC |
32212 | @node GDB Bugs |
32213 | @chapter Reporting Bugs in @value{GDBN} | |
32214 | @cindex bugs in @value{GDBN} | |
32215 | @cindex reporting bugs in @value{GDBN} | |
c906108c | 32216 | |
8e04817f | 32217 | Your bug reports play an essential role in making @value{GDBN} reliable. |
c906108c | 32218 | |
8e04817f AC |
32219 | Reporting a bug may help you by bringing a solution to your problem, or it |
32220 | may not. But in any case the principal function of a bug report is to help | |
32221 | the entire community by making the next version of @value{GDBN} work better. Bug | |
32222 | reports are your contribution to the maintenance of @value{GDBN}. | |
c906108c | 32223 | |
8e04817f AC |
32224 | In order for a bug report to serve its purpose, you must include the |
32225 | information that enables us to fix the bug. | |
c4555f82 SC |
32226 | |
32227 | @menu | |
8e04817f AC |
32228 | * Bug Criteria:: Have you found a bug? |
32229 | * Bug Reporting:: How to report bugs | |
c4555f82 SC |
32230 | @end menu |
32231 | ||
8e04817f | 32232 | @node Bug Criteria |
79a6e687 | 32233 | @section Have You Found a Bug? |
8e04817f | 32234 | @cindex bug criteria |
c4555f82 | 32235 | |
8e04817f | 32236 | If you are not sure whether you have found a bug, here are some guidelines: |
c4555f82 SC |
32237 | |
32238 | @itemize @bullet | |
8e04817f AC |
32239 | @cindex fatal signal |
32240 | @cindex debugger crash | |
32241 | @cindex crash of debugger | |
c4555f82 | 32242 | @item |
8e04817f AC |
32243 | If the debugger gets a fatal signal, for any input whatever, that is a |
32244 | @value{GDBN} bug. Reliable debuggers never crash. | |
32245 | ||
32246 | @cindex error on valid input | |
32247 | @item | |
32248 | If @value{GDBN} produces an error message for valid input, that is a | |
32249 | bug. (Note that if you're cross debugging, the problem may also be | |
32250 | somewhere in the connection to the target.) | |
c4555f82 | 32251 | |
8e04817f | 32252 | @cindex invalid input |
c4555f82 | 32253 | @item |
8e04817f AC |
32254 | If @value{GDBN} does not produce an error message for invalid input, |
32255 | that is a bug. However, you should note that your idea of | |
32256 | ``invalid input'' might be our idea of ``an extension'' or ``support | |
32257 | for traditional practice''. | |
32258 | ||
32259 | @item | |
32260 | If you are an experienced user of debugging tools, your suggestions | |
32261 | for improvement of @value{GDBN} are welcome in any case. | |
c4555f82 SC |
32262 | @end itemize |
32263 | ||
8e04817f | 32264 | @node Bug Reporting |
79a6e687 | 32265 | @section How to Report Bugs |
8e04817f AC |
32266 | @cindex bug reports |
32267 | @cindex @value{GDBN} bugs, reporting | |
32268 | ||
32269 | A number of companies and individuals offer support for @sc{gnu} products. | |
32270 | If you obtained @value{GDBN} from a support organization, we recommend you | |
32271 | contact that organization first. | |
32272 | ||
32273 | You can find contact information for many support companies and | |
32274 | individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs | |
32275 | distribution. | |
32276 | @c should add a web page ref... | |
32277 | ||
c16158bc JM |
32278 | @ifset BUGURL |
32279 | @ifset BUGURL_DEFAULT | |
129188f6 | 32280 | In any event, we also recommend that you submit bug reports for |
d3e8051b | 32281 | @value{GDBN}. The preferred method is to submit them directly using |
129188f6 AC |
32282 | @uref{http://www.gnu.org/software/gdb/bugs/, @value{GDBN}'s Bugs web |
32283 | page}. Alternatively, the @email{bug-gdb@@gnu.org, e-mail gateway} can | |
32284 | be used. | |
8e04817f AC |
32285 | |
32286 | @strong{Do not send bug reports to @samp{info-gdb}, or to | |
32287 | @samp{help-gdb}, or to any newsgroups.} Most users of @value{GDBN} do | |
32288 | not want to receive bug reports. Those that do have arranged to receive | |
32289 | @samp{bug-gdb}. | |
32290 | ||
32291 | The mailing list @samp{bug-gdb} has a newsgroup @samp{gnu.gdb.bug} which | |
32292 | serves as a repeater. The mailing list and the newsgroup carry exactly | |
32293 | the same messages. Often people think of posting bug reports to the | |
32294 | newsgroup instead of mailing them. This appears to work, but it has one | |
32295 | problem which can be crucial: a newsgroup posting often lacks a mail | |
32296 | path back to the sender. Thus, if we need to ask for more information, | |
32297 | we may be unable to reach you. For this reason, it is better to send | |
32298 | bug reports to the mailing list. | |
c16158bc JM |
32299 | @end ifset |
32300 | @ifclear BUGURL_DEFAULT | |
32301 | In any event, we also recommend that you submit bug reports for | |
32302 | @value{GDBN} to @value{BUGURL}. | |
32303 | @end ifclear | |
32304 | @end ifset | |
c4555f82 | 32305 | |
8e04817f AC |
32306 | The fundamental principle of reporting bugs usefully is this: |
32307 | @strong{report all the facts}. If you are not sure whether to state a | |
32308 | fact or leave it out, state it! | |
c4555f82 | 32309 | |
8e04817f AC |
32310 | Often people omit facts because they think they know what causes the |
32311 | problem and assume that some details do not matter. Thus, you might | |
32312 | assume that the name of the variable you use in an example does not matter. | |
32313 | Well, probably it does not, but one cannot be sure. Perhaps the bug is a | |
32314 | stray memory reference which happens to fetch from the location where that | |
32315 | name is stored in memory; perhaps, if the name were different, the contents | |
32316 | of that location would fool the debugger into doing the right thing despite | |
32317 | the bug. Play it safe and give a specific, complete example. That is the | |
32318 | easiest thing for you to do, and the most helpful. | |
c4555f82 | 32319 | |
8e04817f AC |
32320 | Keep in mind that the purpose of a bug report is to enable us to fix the |
32321 | bug. It may be that the bug has been reported previously, but neither | |
32322 | you nor we can know that unless your bug report is complete and | |
32323 | self-contained. | |
c4555f82 | 32324 | |
8e04817f AC |
32325 | Sometimes people give a few sketchy facts and ask, ``Does this ring a |
32326 | bell?'' Those bug reports are useless, and we urge everyone to | |
32327 | @emph{refuse to respond to them} except to chide the sender to report | |
32328 | bugs properly. | |
32329 | ||
32330 | To enable us to fix the bug, you should include all these things: | |
c4555f82 SC |
32331 | |
32332 | @itemize @bullet | |
32333 | @item | |
8e04817f AC |
32334 | The version of @value{GDBN}. @value{GDBN} announces it if you start |
32335 | with no arguments; you can also print it at any time using @code{show | |
32336 | version}. | |
c4555f82 | 32337 | |
8e04817f AC |
32338 | Without this, we will not know whether there is any point in looking for |
32339 | the bug in the current version of @value{GDBN}. | |
c4555f82 SC |
32340 | |
32341 | @item | |
8e04817f AC |
32342 | The type of machine you are using, and the operating system name and |
32343 | version number. | |
c4555f82 | 32344 | |
6eaaf48b EZ |
32345 | @item |
32346 | The details of the @value{GDBN} build-time configuration. | |
32347 | @value{GDBN} shows these details if you invoke it with the | |
32348 | @option{--configuration} command-line option, or if you type | |
32349 | @code{show configuration} at @value{GDBN}'s prompt. | |
32350 | ||
c4555f82 | 32351 | @item |
c1468174 | 32352 | What compiler (and its version) was used to compile @value{GDBN}---e.g.@: |
8e04817f | 32353 | ``@value{GCC}--2.8.1''. |
c4555f82 SC |
32354 | |
32355 | @item | |
8e04817f | 32356 | What compiler (and its version) was used to compile the program you are |
c1468174 | 32357 | debugging---e.g.@: ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP |
3f94c067 BW |
32358 | C Compiler''. For @value{NGCC}, you can say @kbd{@value{GCC} --version} |
32359 | to get this information; for other compilers, see the documentation for | |
32360 | those compilers. | |
c4555f82 | 32361 | |
8e04817f AC |
32362 | @item |
32363 | The command arguments you gave the compiler to compile your example and | |
32364 | observe the bug. For example, did you use @samp{-O}? To guarantee | |
32365 | you will not omit something important, list them all. A copy of the | |
32366 | Makefile (or the output from make) is sufficient. | |
c4555f82 | 32367 | |
8e04817f AC |
32368 | If we were to try to guess the arguments, we would probably guess wrong |
32369 | and then we might not encounter the bug. | |
c4555f82 | 32370 | |
8e04817f AC |
32371 | @item |
32372 | A complete input script, and all necessary source files, that will | |
32373 | reproduce the bug. | |
c4555f82 | 32374 | |
8e04817f AC |
32375 | @item |
32376 | A description of what behavior you observe that you believe is | |
32377 | incorrect. For example, ``It gets a fatal signal.'' | |
c4555f82 | 32378 | |
8e04817f AC |
32379 | Of course, if the bug is that @value{GDBN} gets a fatal signal, then we |
32380 | will certainly notice it. But if the bug is incorrect output, we might | |
32381 | not notice unless it is glaringly wrong. You might as well not give us | |
32382 | a chance to make a mistake. | |
c4555f82 | 32383 | |
8e04817f AC |
32384 | Even if the problem you experience is a fatal signal, you should still |
32385 | say so explicitly. Suppose something strange is going on, such as, your | |
32386 | copy of @value{GDBN} is out of synch, or you have encountered a bug in | |
32387 | the C library on your system. (This has happened!) Your copy might | |
32388 | crash and ours would not. If you told us to expect a crash, then when | |
32389 | ours fails to crash, we would know that the bug was not happening for | |
32390 | us. If you had not told us to expect a crash, then we would not be able | |
32391 | to draw any conclusion from our observations. | |
c4555f82 | 32392 | |
e0c07bf0 MC |
32393 | @pindex script |
32394 | @cindex recording a session script | |
32395 | To collect all this information, you can use a session recording program | |
32396 | such as @command{script}, which is available on many Unix systems. | |
32397 | Just run your @value{GDBN} session inside @command{script} and then | |
32398 | include the @file{typescript} file with your bug report. | |
32399 | ||
32400 | Another way to record a @value{GDBN} session is to run @value{GDBN} | |
32401 | inside Emacs and then save the entire buffer to a file. | |
32402 | ||
8e04817f AC |
32403 | @item |
32404 | If you wish to suggest changes to the @value{GDBN} source, send us context | |
32405 | diffs. If you even discuss something in the @value{GDBN} source, refer to | |
32406 | it by context, not by line number. | |
c4555f82 | 32407 | |
8e04817f AC |
32408 | The line numbers in our development sources will not match those in your |
32409 | sources. Your line numbers would convey no useful information to us. | |
c4555f82 | 32410 | |
8e04817f | 32411 | @end itemize |
c4555f82 | 32412 | |
8e04817f | 32413 | Here are some things that are not necessary: |
c4555f82 | 32414 | |
8e04817f AC |
32415 | @itemize @bullet |
32416 | @item | |
32417 | A description of the envelope of the bug. | |
c4555f82 | 32418 | |
8e04817f AC |
32419 | Often people who encounter a bug spend a lot of time investigating |
32420 | which changes to the input file will make the bug go away and which | |
32421 | changes will not affect it. | |
c4555f82 | 32422 | |
8e04817f AC |
32423 | This is often time consuming and not very useful, because the way we |
32424 | will find the bug is by running a single example under the debugger | |
32425 | with breakpoints, not by pure deduction from a series of examples. | |
32426 | We recommend that you save your time for something else. | |
c4555f82 | 32427 | |
8e04817f AC |
32428 | Of course, if you can find a simpler example to report @emph{instead} |
32429 | of the original one, that is a convenience for us. Errors in the | |
32430 | output will be easier to spot, running under the debugger will take | |
32431 | less time, and so on. | |
c4555f82 | 32432 | |
8e04817f AC |
32433 | However, simplification is not vital; if you do not want to do this, |
32434 | report the bug anyway and send us the entire test case you used. | |
c4555f82 | 32435 | |
8e04817f AC |
32436 | @item |
32437 | A patch for the bug. | |
c4555f82 | 32438 | |
8e04817f AC |
32439 | A patch for the bug does help us if it is a good one. But do not omit |
32440 | the necessary information, such as the test case, on the assumption that | |
32441 | a patch is all we need. We might see problems with your patch and decide | |
32442 | to fix the problem another way, or we might not understand it at all. | |
c4555f82 | 32443 | |
8e04817f AC |
32444 | Sometimes with a program as complicated as @value{GDBN} it is very hard to |
32445 | construct an example that will make the program follow a certain path | |
32446 | through the code. If you do not send us the example, we will not be able | |
32447 | to construct one, so we will not be able to verify that the bug is fixed. | |
c4555f82 | 32448 | |
8e04817f AC |
32449 | And if we cannot understand what bug you are trying to fix, or why your |
32450 | patch should be an improvement, we will not install it. A test case will | |
32451 | help us to understand. | |
c4555f82 | 32452 | |
8e04817f AC |
32453 | @item |
32454 | A guess about what the bug is or what it depends on. | |
c4555f82 | 32455 | |
8e04817f AC |
32456 | Such guesses are usually wrong. Even we cannot guess right about such |
32457 | things without first using the debugger to find the facts. | |
32458 | @end itemize | |
c4555f82 | 32459 | |
8e04817f AC |
32460 | @c The readline documentation is distributed with the readline code |
32461 | @c and consists of the two following files: | |
cc88a640 JK |
32462 | @c rluser.texi |
32463 | @c hsuser.texi | |
8e04817f AC |
32464 | @c Use -I with makeinfo to point to the appropriate directory, |
32465 | @c environment var TEXINPUTS with TeX. | |
39037522 | 32466 | @ifclear SYSTEM_READLINE |
5bdf8622 | 32467 | @include rluser.texi |
cc88a640 | 32468 | @include hsuser.texi |
39037522 | 32469 | @end ifclear |
c4555f82 | 32470 | |
4ceed123 JB |
32471 | @node In Memoriam |
32472 | @appendix In Memoriam | |
32473 | ||
9ed350ad JB |
32474 | The @value{GDBN} project mourns the loss of the following long-time |
32475 | contributors: | |
4ceed123 JB |
32476 | |
32477 | @table @code | |
32478 | @item Fred Fish | |
9ed350ad JB |
32479 | Fred was a long-standing contributor to @value{GDBN} (1991-2006), and |
32480 | to Free Software in general. Outside of @value{GDBN}, he was known in | |
32481 | the Amiga world for his series of Fish Disks, and the GeekGadget project. | |
4ceed123 JB |
32482 | |
32483 | @item Michael Snyder | |
9ed350ad JB |
32484 | Michael was one of the Global Maintainers of the @value{GDBN} project, |
32485 | with contributions recorded as early as 1996, until 2011. In addition | |
32486 | to his day to day participation, he was a large driving force behind | |
32487 | adding Reverse Debugging to @value{GDBN}. | |
4ceed123 JB |
32488 | @end table |
32489 | ||
32490 | Beyond their technical contributions to the project, they were also | |
32491 | enjoyable members of the Free Software Community. We will miss them. | |
c4555f82 | 32492 | |
8e04817f AC |
32493 | @node Formatting Documentation |
32494 | @appendix Formatting Documentation | |
c4555f82 | 32495 | |
8e04817f AC |
32496 | @cindex @value{GDBN} reference card |
32497 | @cindex reference card | |
32498 | The @value{GDBN} 4 release includes an already-formatted reference card, ready | |
32499 | for printing with PostScript or Ghostscript, in the @file{gdb} | |
32500 | subdirectory of the main source directory@footnote{In | |
32501 | @file{gdb-@value{GDBVN}/gdb/refcard.ps} of the version @value{GDBVN} | |
32502 | release.}. If you can use PostScript or Ghostscript with your printer, | |
32503 | you can print the reference card immediately with @file{refcard.ps}. | |
c4555f82 | 32504 | |
8e04817f AC |
32505 | The release also includes the source for the reference card. You |
32506 | can format it, using @TeX{}, by typing: | |
c4555f82 | 32507 | |
474c8240 | 32508 | @smallexample |
8e04817f | 32509 | make refcard.dvi |
474c8240 | 32510 | @end smallexample |
c4555f82 | 32511 | |
8e04817f AC |
32512 | The @value{GDBN} reference card is designed to print in @dfn{landscape} |
32513 | mode on US ``letter'' size paper; | |
32514 | that is, on a sheet 11 inches wide by 8.5 inches | |
32515 | high. You will need to specify this form of printing as an option to | |
32516 | your @sc{dvi} output program. | |
c4555f82 | 32517 | |
8e04817f | 32518 | @cindex documentation |
c4555f82 | 32519 | |
8e04817f AC |
32520 | All the documentation for @value{GDBN} comes as part of the machine-readable |
32521 | distribution. The documentation is written in Texinfo format, which is | |
32522 | a documentation system that uses a single source file to produce both | |
32523 | on-line information and a printed manual. You can use one of the Info | |
32524 | formatting commands to create the on-line version of the documentation | |
32525 | and @TeX{} (or @code{texi2roff}) to typeset the printed version. | |
c4555f82 | 32526 | |
8e04817f AC |
32527 | @value{GDBN} includes an already formatted copy of the on-line Info |
32528 | version of this manual in the @file{gdb} subdirectory. The main Info | |
32529 | file is @file{gdb-@value{GDBVN}/gdb/gdb.info}, and it refers to | |
32530 | subordinate files matching @samp{gdb.info*} in the same directory. If | |
32531 | necessary, you can print out these files, or read them with any editor; | |
32532 | but they are easier to read using the @code{info} subsystem in @sc{gnu} | |
32533 | Emacs or the standalone @code{info} program, available as part of the | |
32534 | @sc{gnu} Texinfo distribution. | |
c4555f82 | 32535 | |
8e04817f AC |
32536 | If you want to format these Info files yourself, you need one of the |
32537 | Info formatting programs, such as @code{texinfo-format-buffer} or | |
32538 | @code{makeinfo}. | |
c4555f82 | 32539 | |
8e04817f AC |
32540 | If you have @code{makeinfo} installed, and are in the top level |
32541 | @value{GDBN} source directory (@file{gdb-@value{GDBVN}}, in the case of | |
32542 | version @value{GDBVN}), you can make the Info file by typing: | |
c4555f82 | 32543 | |
474c8240 | 32544 | @smallexample |
8e04817f AC |
32545 | cd gdb |
32546 | make gdb.info | |
474c8240 | 32547 | @end smallexample |
c4555f82 | 32548 | |
8e04817f AC |
32549 | If you want to typeset and print copies of this manual, you need @TeX{}, |
32550 | a program to print its @sc{dvi} output files, and @file{texinfo.tex}, the | |
32551 | Texinfo definitions file. | |
c4555f82 | 32552 | |
8e04817f AC |
32553 | @TeX{} is a typesetting program; it does not print files directly, but |
32554 | produces output files called @sc{dvi} files. To print a typeset | |
32555 | document, you need a program to print @sc{dvi} files. If your system | |
32556 | has @TeX{} installed, chances are it has such a program. The precise | |
32557 | command to use depends on your system; @kbd{lpr -d} is common; another | |
32558 | (for PostScript devices) is @kbd{dvips}. The @sc{dvi} print command may | |
32559 | require a file name without any extension or a @samp{.dvi} extension. | |
c4555f82 | 32560 | |
8e04817f AC |
32561 | @TeX{} also requires a macro definitions file called |
32562 | @file{texinfo.tex}. This file tells @TeX{} how to typeset a document | |
32563 | written in Texinfo format. On its own, @TeX{} cannot either read or | |
32564 | typeset a Texinfo file. @file{texinfo.tex} is distributed with GDB | |
32565 | and is located in the @file{gdb-@var{version-number}/texinfo} | |
32566 | directory. | |
c4555f82 | 32567 | |
8e04817f | 32568 | If you have @TeX{} and a @sc{dvi} printer program installed, you can |
d3e8051b | 32569 | typeset and print this manual. First switch to the @file{gdb} |
8e04817f AC |
32570 | subdirectory of the main source directory (for example, to |
32571 | @file{gdb-@value{GDBVN}/gdb}) and type: | |
c4555f82 | 32572 | |
474c8240 | 32573 | @smallexample |
8e04817f | 32574 | make gdb.dvi |
474c8240 | 32575 | @end smallexample |
c4555f82 | 32576 | |
8e04817f | 32577 | Then give @file{gdb.dvi} to your @sc{dvi} printing program. |
c4555f82 | 32578 | |
8e04817f AC |
32579 | @node Installing GDB |
32580 | @appendix Installing @value{GDBN} | |
8e04817f | 32581 | @cindex installation |
c4555f82 | 32582 | |
7fa2210b DJ |
32583 | @menu |
32584 | * Requirements:: Requirements for building @value{GDBN} | |
db2e3e2e | 32585 | * Running Configure:: Invoking the @value{GDBN} @file{configure} script |
7fa2210b DJ |
32586 | * Separate Objdir:: Compiling @value{GDBN} in another directory |
32587 | * Config Names:: Specifying names for hosts and targets | |
32588 | * Configure Options:: Summary of options for configure | |
098b41a6 | 32589 | * System-wide configuration:: Having a system-wide init file |
7fa2210b DJ |
32590 | @end menu |
32591 | ||
32592 | @node Requirements | |
79a6e687 | 32593 | @section Requirements for Building @value{GDBN} |
7fa2210b DJ |
32594 | @cindex building @value{GDBN}, requirements for |
32595 | ||
32596 | Building @value{GDBN} requires various tools and packages to be available. | |
32597 | Other packages will be used only if they are found. | |
32598 | ||
79a6e687 | 32599 | @heading Tools/Packages Necessary for Building @value{GDBN} |
7fa2210b DJ |
32600 | @table @asis |
32601 | @item ISO C90 compiler | |
32602 | @value{GDBN} is written in ISO C90. It should be buildable with any | |
32603 | working C90 compiler, e.g.@: GCC. | |
32604 | ||
32605 | @end table | |
32606 | ||
79a6e687 | 32607 | @heading Tools/Packages Optional for Building @value{GDBN} |
7fa2210b DJ |
32608 | @table @asis |
32609 | @item Expat | |
123dc839 | 32610 | @anchor{Expat} |
7fa2210b DJ |
32611 | @value{GDBN} can use the Expat XML parsing library. This library may be |
32612 | included with your operating system distribution; if it is not, you | |
32613 | can get the latest version from @url{http://expat.sourceforge.net}. | |
db2e3e2e | 32614 | The @file{configure} script will search for this library in several |
7fa2210b DJ |
32615 | standard locations; if it is installed in an unusual path, you can |
32616 | use the @option{--with-libexpat-prefix} option to specify its location. | |
32617 | ||
9cceb671 DJ |
32618 | Expat is used for: |
32619 | ||
32620 | @itemize @bullet | |
32621 | @item | |
32622 | Remote protocol memory maps (@pxref{Memory Map Format}) | |
32623 | @item | |
32624 | Target descriptions (@pxref{Target Descriptions}) | |
32625 | @item | |
2268b414 JK |
32626 | Remote shared library lists (@xref{Library List Format}, |
32627 | or alternatively @pxref{Library List Format for SVR4 Targets}) | |
9cceb671 DJ |
32628 | @item |
32629 | MS-Windows shared libraries (@pxref{Shared Libraries}) | |
b3b9301e PA |
32630 | @item |
32631 | Traceframe info (@pxref{Traceframe Info Format}) | |
2ae8c8e7 MM |
32632 | @item |
32633 | Branch trace (@pxref{Branch Trace Format}) | |
9cceb671 | 32634 | @end itemize |
7fa2210b | 32635 | |
31fffb02 CS |
32636 | @item zlib |
32637 | @cindex compressed debug sections | |
32638 | @value{GDBN} will use the @samp{zlib} library, if available, to read | |
32639 | compressed debug sections. Some linkers, such as GNU gold, are capable | |
32640 | of producing binaries with compressed debug sections. If @value{GDBN} | |
32641 | is compiled with @samp{zlib}, it will be able to read the debug | |
32642 | information in such binaries. | |
32643 | ||
32644 | The @samp{zlib} library is likely included with your operating system | |
32645 | distribution; if it is not, you can get the latest version from | |
32646 | @url{http://zlib.net}. | |
32647 | ||
6c7a06a3 TT |
32648 | @item iconv |
32649 | @value{GDBN}'s features related to character sets (@pxref{Character | |
32650 | Sets}) require a functioning @code{iconv} implementation. If you are | |
32651 | on a GNU system, then this is provided by the GNU C Library. Some | |
32652 | other systems also provide a working @code{iconv}. | |
32653 | ||
478aac75 DE |
32654 | If @value{GDBN} is using the @code{iconv} program which is installed |
32655 | in a non-standard place, you will need to tell @value{GDBN} where to find it. | |
32656 | This is done with @option{--with-iconv-bin} which specifies the | |
32657 | directory that contains the @code{iconv} program. | |
32658 | ||
32659 | On systems without @code{iconv}, you can install GNU Libiconv. If you | |
6c7a06a3 TT |
32660 | have previously installed Libiconv, you can use the |
32661 | @option{--with-libiconv-prefix} option to configure. | |
32662 | ||
32663 | @value{GDBN}'s top-level @file{configure} and @file{Makefile} will | |
32664 | arrange to build Libiconv if a directory named @file{libiconv} appears | |
32665 | in the top-most source directory. If Libiconv is built this way, and | |
32666 | if the operating system does not provide a suitable @code{iconv} | |
32667 | implementation, then the just-built library will automatically be used | |
32668 | by @value{GDBN}. One easy way to set this up is to download GNU | |
32669 | Libiconv, unpack it, and then rename the directory holding the | |
32670 | Libiconv source code to @samp{libiconv}. | |
7fa2210b DJ |
32671 | @end table |
32672 | ||
32673 | @node Running Configure | |
db2e3e2e | 32674 | @section Invoking the @value{GDBN} @file{configure} Script |
7fa2210b | 32675 | @cindex configuring @value{GDBN} |
db2e3e2e | 32676 | @value{GDBN} comes with a @file{configure} script that automates the process |
8e04817f AC |
32677 | of preparing @value{GDBN} for installation; you can then use @code{make} to |
32678 | build the @code{gdb} program. | |
32679 | @iftex | |
32680 | @c irrelevant in info file; it's as current as the code it lives with. | |
32681 | @footnote{If you have a more recent version of @value{GDBN} than @value{GDBVN}, | |
32682 | look at the @file{README} file in the sources; we may have improved the | |
32683 | installation procedures since publishing this manual.} | |
32684 | @end iftex | |
c4555f82 | 32685 | |
8e04817f AC |
32686 | The @value{GDBN} distribution includes all the source code you need for |
32687 | @value{GDBN} in a single directory, whose name is usually composed by | |
32688 | appending the version number to @samp{gdb}. | |
c4555f82 | 32689 | |
8e04817f AC |
32690 | For example, the @value{GDBN} version @value{GDBVN} distribution is in the |
32691 | @file{gdb-@value{GDBVN}} directory. That directory contains: | |
c4555f82 | 32692 | |
8e04817f AC |
32693 | @table @code |
32694 | @item gdb-@value{GDBVN}/configure @r{(and supporting files)} | |
32695 | script for configuring @value{GDBN} and all its supporting libraries | |
c4555f82 | 32696 | |
8e04817f AC |
32697 | @item gdb-@value{GDBVN}/gdb |
32698 | the source specific to @value{GDBN} itself | |
c4555f82 | 32699 | |
8e04817f AC |
32700 | @item gdb-@value{GDBVN}/bfd |
32701 | source for the Binary File Descriptor library | |
c906108c | 32702 | |
8e04817f AC |
32703 | @item gdb-@value{GDBVN}/include |
32704 | @sc{gnu} include files | |
c906108c | 32705 | |
8e04817f AC |
32706 | @item gdb-@value{GDBVN}/libiberty |
32707 | source for the @samp{-liberty} free software library | |
c906108c | 32708 | |
8e04817f AC |
32709 | @item gdb-@value{GDBVN}/opcodes |
32710 | source for the library of opcode tables and disassemblers | |
c906108c | 32711 | |
8e04817f AC |
32712 | @item gdb-@value{GDBVN}/readline |
32713 | source for the @sc{gnu} command-line interface | |
c906108c | 32714 | |
8e04817f AC |
32715 | @item gdb-@value{GDBVN}/glob |
32716 | source for the @sc{gnu} filename pattern-matching subroutine | |
c906108c | 32717 | |
8e04817f AC |
32718 | @item gdb-@value{GDBVN}/mmalloc |
32719 | source for the @sc{gnu} memory-mapped malloc package | |
32720 | @end table | |
c906108c | 32721 | |
db2e3e2e | 32722 | The simplest way to configure and build @value{GDBN} is to run @file{configure} |
8e04817f AC |
32723 | from the @file{gdb-@var{version-number}} source directory, which in |
32724 | this example is the @file{gdb-@value{GDBVN}} directory. | |
c906108c | 32725 | |
8e04817f | 32726 | First switch to the @file{gdb-@var{version-number}} source directory |
db2e3e2e | 32727 | if you are not already in it; then run @file{configure}. Pass the |
8e04817f AC |
32728 | identifier for the platform on which @value{GDBN} will run as an |
32729 | argument. | |
c906108c | 32730 | |
8e04817f | 32731 | For example: |
c906108c | 32732 | |
474c8240 | 32733 | @smallexample |
8e04817f AC |
32734 | cd gdb-@value{GDBVN} |
32735 | ./configure @var{host} | |
32736 | make | |
474c8240 | 32737 | @end smallexample |
c906108c | 32738 | |
8e04817f AC |
32739 | @noindent |
32740 | where @var{host} is an identifier such as @samp{sun4} or | |
32741 | @samp{decstation}, that identifies the platform where @value{GDBN} will run. | |
db2e3e2e | 32742 | (You can often leave off @var{host}; @file{configure} tries to guess the |
8e04817f | 32743 | correct value by examining your system.) |
c906108c | 32744 | |
8e04817f AC |
32745 | Running @samp{configure @var{host}} and then running @code{make} builds the |
32746 | @file{bfd}, @file{readline}, @file{mmalloc}, and @file{libiberty} | |
32747 | libraries, then @code{gdb} itself. The configured source files, and the | |
32748 | binaries, are left in the corresponding source directories. | |
c906108c | 32749 | |
8e04817f | 32750 | @need 750 |
db2e3e2e | 32751 | @file{configure} is a Bourne-shell (@code{/bin/sh}) script; if your |
8e04817f AC |
32752 | system does not recognize this automatically when you run a different |
32753 | shell, you may need to run @code{sh} on it explicitly: | |
c906108c | 32754 | |
474c8240 | 32755 | @smallexample |
8e04817f | 32756 | sh configure @var{host} |
474c8240 | 32757 | @end smallexample |
c906108c | 32758 | |
db2e3e2e | 32759 | If you run @file{configure} from a directory that contains source |
8e04817f | 32760 | directories for multiple libraries or programs, such as the |
db2e3e2e BW |
32761 | @file{gdb-@value{GDBVN}} source directory for version @value{GDBVN}, |
32762 | @file{configure} | |
8e04817f AC |
32763 | creates configuration files for every directory level underneath (unless |
32764 | you tell it not to, with the @samp{--norecursion} option). | |
32765 | ||
db2e3e2e | 32766 | You should run the @file{configure} script from the top directory in the |
94e91d6d | 32767 | source tree, the @file{gdb-@var{version-number}} directory. If you run |
db2e3e2e | 32768 | @file{configure} from one of the subdirectories, you will configure only |
94e91d6d | 32769 | that subdirectory. That is usually not what you want. In particular, |
db2e3e2e | 32770 | if you run the first @file{configure} from the @file{gdb} subdirectory |
94e91d6d MC |
32771 | of the @file{gdb-@var{version-number}} directory, you will omit the |
32772 | configuration of @file{bfd}, @file{readline}, and other sibling | |
32773 | directories of the @file{gdb} subdirectory. This leads to build errors | |
32774 | about missing include files such as @file{bfd/bfd.h}. | |
c906108c | 32775 | |
8e04817f AC |
32776 | You can install @code{@value{GDBP}} anywhere; it has no hardwired paths. |
32777 | However, you should make sure that the shell on your path (named by | |
32778 | the @samp{SHELL} environment variable) is publicly readable. Remember | |
32779 | that @value{GDBN} uses the shell to start your program---some systems refuse to | |
32780 | let @value{GDBN} debug child processes whose programs are not readable. | |
c906108c | 32781 | |
8e04817f | 32782 | @node Separate Objdir |
79a6e687 | 32783 | @section Compiling @value{GDBN} in Another Directory |
c906108c | 32784 | |
8e04817f AC |
32785 | If you want to run @value{GDBN} versions for several host or target machines, |
32786 | you need a different @code{gdb} compiled for each combination of | |
db2e3e2e | 32787 | host and target. @file{configure} is designed to make this easy by |
8e04817f AC |
32788 | allowing you to generate each configuration in a separate subdirectory, |
32789 | rather than in the source directory. If your @code{make} program | |
32790 | handles the @samp{VPATH} feature (@sc{gnu} @code{make} does), running | |
32791 | @code{make} in each of these directories builds the @code{gdb} | |
32792 | program specified there. | |
c906108c | 32793 | |
db2e3e2e | 32794 | To build @code{gdb} in a separate directory, run @file{configure} |
8e04817f | 32795 | with the @samp{--srcdir} option to specify where to find the source. |
db2e3e2e BW |
32796 | (You also need to specify a path to find @file{configure} |
32797 | itself from your working directory. If the path to @file{configure} | |
8e04817f AC |
32798 | would be the same as the argument to @samp{--srcdir}, you can leave out |
32799 | the @samp{--srcdir} option; it is assumed.) | |
c906108c | 32800 | |
8e04817f AC |
32801 | For example, with version @value{GDBVN}, you can build @value{GDBN} in a |
32802 | separate directory for a Sun 4 like this: | |
c906108c | 32803 | |
474c8240 | 32804 | @smallexample |
8e04817f AC |
32805 | @group |
32806 | cd gdb-@value{GDBVN} | |
32807 | mkdir ../gdb-sun4 | |
32808 | cd ../gdb-sun4 | |
32809 | ../gdb-@value{GDBVN}/configure sun4 | |
32810 | make | |
32811 | @end group | |
474c8240 | 32812 | @end smallexample |
c906108c | 32813 | |
db2e3e2e | 32814 | When @file{configure} builds a configuration using a remote source |
8e04817f AC |
32815 | directory, it creates a tree for the binaries with the same structure |
32816 | (and using the same names) as the tree under the source directory. In | |
32817 | the example, you'd find the Sun 4 library @file{libiberty.a} in the | |
32818 | directory @file{gdb-sun4/libiberty}, and @value{GDBN} itself in | |
32819 | @file{gdb-sun4/gdb}. | |
c906108c | 32820 | |
94e91d6d MC |
32821 | Make sure that your path to the @file{configure} script has just one |
32822 | instance of @file{gdb} in it. If your path to @file{configure} looks | |
32823 | like @file{../gdb-@value{GDBVN}/gdb/configure}, you are configuring only | |
32824 | one subdirectory of @value{GDBN}, not the whole package. This leads to | |
32825 | build errors about missing include files such as @file{bfd/bfd.h}. | |
32826 | ||
8e04817f AC |
32827 | One popular reason to build several @value{GDBN} configurations in separate |
32828 | directories is to configure @value{GDBN} for cross-compiling (where | |
32829 | @value{GDBN} runs on one machine---the @dfn{host}---while debugging | |
32830 | programs that run on another machine---the @dfn{target}). | |
32831 | You specify a cross-debugging target by | |
db2e3e2e | 32832 | giving the @samp{--target=@var{target}} option to @file{configure}. |
c906108c | 32833 | |
8e04817f AC |
32834 | When you run @code{make} to build a program or library, you must run |
32835 | it in a configured directory---whatever directory you were in when you | |
db2e3e2e | 32836 | called @file{configure} (or one of its subdirectories). |
c906108c | 32837 | |
db2e3e2e | 32838 | The @code{Makefile} that @file{configure} generates in each source |
8e04817f AC |
32839 | directory also runs recursively. If you type @code{make} in a source |
32840 | directory such as @file{gdb-@value{GDBVN}} (or in a separate configured | |
32841 | directory configured with @samp{--srcdir=@var{dirname}/gdb-@value{GDBVN}}), you | |
32842 | will build all the required libraries, and then build GDB. | |
c906108c | 32843 | |
8e04817f AC |
32844 | When you have multiple hosts or targets configured in separate |
32845 | directories, you can run @code{make} on them in parallel (for example, | |
32846 | if they are NFS-mounted on each of the hosts); they will not interfere | |
32847 | with each other. | |
c906108c | 32848 | |
8e04817f | 32849 | @node Config Names |
79a6e687 | 32850 | @section Specifying Names for Hosts and Targets |
c906108c | 32851 | |
db2e3e2e | 32852 | The specifications used for hosts and targets in the @file{configure} |
8e04817f AC |
32853 | script are based on a three-part naming scheme, but some short predefined |
32854 | aliases are also supported. The full naming scheme encodes three pieces | |
32855 | of information in the following pattern: | |
c906108c | 32856 | |
474c8240 | 32857 | @smallexample |
8e04817f | 32858 | @var{architecture}-@var{vendor}-@var{os} |
474c8240 | 32859 | @end smallexample |
c906108c | 32860 | |
8e04817f AC |
32861 | For example, you can use the alias @code{sun4} as a @var{host} argument, |
32862 | or as the value for @var{target} in a @code{--target=@var{target}} | |
32863 | option. The equivalent full name is @samp{sparc-sun-sunos4}. | |
c906108c | 32864 | |
db2e3e2e | 32865 | The @file{configure} script accompanying @value{GDBN} does not provide |
8e04817f | 32866 | any query facility to list all supported host and target names or |
db2e3e2e | 32867 | aliases. @file{configure} calls the Bourne shell script |
8e04817f AC |
32868 | @code{config.sub} to map abbreviations to full names; you can read the |
32869 | script, if you wish, or you can use it to test your guesses on | |
32870 | abbreviations---for example: | |
c906108c | 32871 | |
8e04817f AC |
32872 | @smallexample |
32873 | % sh config.sub i386-linux | |
32874 | i386-pc-linux-gnu | |
32875 | % sh config.sub alpha-linux | |
32876 | alpha-unknown-linux-gnu | |
32877 | % sh config.sub hp9k700 | |
32878 | hppa1.1-hp-hpux | |
32879 | % sh config.sub sun4 | |
32880 | sparc-sun-sunos4.1.1 | |
32881 | % sh config.sub sun3 | |
32882 | m68k-sun-sunos4.1.1 | |
32883 | % sh config.sub i986v | |
32884 | Invalid configuration `i986v': machine `i986v' not recognized | |
32885 | @end smallexample | |
c906108c | 32886 | |
8e04817f AC |
32887 | @noindent |
32888 | @code{config.sub} is also distributed in the @value{GDBN} source | |
32889 | directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}). | |
d700128c | 32890 | |
8e04817f | 32891 | @node Configure Options |
db2e3e2e | 32892 | @section @file{configure} Options |
c906108c | 32893 | |
db2e3e2e BW |
32894 | Here is a summary of the @file{configure} options and arguments that |
32895 | are most often useful for building @value{GDBN}. @file{configure} also has | |
8e04817f | 32896 | several other options not listed here. @inforef{What Configure |
db2e3e2e | 32897 | Does,,configure.info}, for a full explanation of @file{configure}. |
c906108c | 32898 | |
474c8240 | 32899 | @smallexample |
8e04817f AC |
32900 | configure @r{[}--help@r{]} |
32901 | @r{[}--prefix=@var{dir}@r{]} | |
32902 | @r{[}--exec-prefix=@var{dir}@r{]} | |
32903 | @r{[}--srcdir=@var{dirname}@r{]} | |
32904 | @r{[}--norecursion@r{]} @r{[}--rm@r{]} | |
32905 | @r{[}--target=@var{target}@r{]} | |
32906 | @var{host} | |
474c8240 | 32907 | @end smallexample |
c906108c | 32908 | |
8e04817f AC |
32909 | @noindent |
32910 | You may introduce options with a single @samp{-} rather than | |
32911 | @samp{--} if you prefer; but you may abbreviate option names if you use | |
32912 | @samp{--}. | |
c906108c | 32913 | |
8e04817f AC |
32914 | @table @code |
32915 | @item --help | |
db2e3e2e | 32916 | Display a quick summary of how to invoke @file{configure}. |
c906108c | 32917 | |
8e04817f AC |
32918 | @item --prefix=@var{dir} |
32919 | Configure the source to install programs and files under directory | |
32920 | @file{@var{dir}}. | |
c906108c | 32921 | |
8e04817f AC |
32922 | @item --exec-prefix=@var{dir} |
32923 | Configure the source to install programs under directory | |
32924 | @file{@var{dir}}. | |
c906108c | 32925 | |
8e04817f AC |
32926 | @c avoid splitting the warning from the explanation: |
32927 | @need 2000 | |
32928 | @item --srcdir=@var{dirname} | |
32929 | @strong{Warning: using this option requires @sc{gnu} @code{make}, or another | |
32930 | @code{make} that implements the @code{VPATH} feature.}@* | |
32931 | Use this option to make configurations in directories separate from the | |
32932 | @value{GDBN} source directories. Among other things, you can use this to | |
32933 | build (or maintain) several configurations simultaneously, in separate | |
db2e3e2e | 32934 | directories. @file{configure} writes configuration-specific files in |
8e04817f | 32935 | the current directory, but arranges for them to use the source in the |
db2e3e2e | 32936 | directory @var{dirname}. @file{configure} creates directories under |
8e04817f AC |
32937 | the working directory in parallel to the source directories below |
32938 | @var{dirname}. | |
c906108c | 32939 | |
8e04817f | 32940 | @item --norecursion |
db2e3e2e | 32941 | Configure only the directory level where @file{configure} is executed; do not |
8e04817f | 32942 | propagate configuration to subdirectories. |
c906108c | 32943 | |
8e04817f AC |
32944 | @item --target=@var{target} |
32945 | Configure @value{GDBN} for cross-debugging programs running on the specified | |
32946 | @var{target}. Without this option, @value{GDBN} is configured to debug | |
32947 | programs that run on the same machine (@var{host}) as @value{GDBN} itself. | |
c906108c | 32948 | |
8e04817f | 32949 | There is no convenient way to generate a list of all available targets. |
c906108c | 32950 | |
8e04817f AC |
32951 | @item @var{host} @dots{} |
32952 | Configure @value{GDBN} to run on the specified @var{host}. | |
c906108c | 32953 | |
8e04817f AC |
32954 | There is no convenient way to generate a list of all available hosts. |
32955 | @end table | |
c906108c | 32956 | |
8e04817f AC |
32957 | There are many other options available as well, but they are generally |
32958 | needed for special purposes only. | |
c906108c | 32959 | |
098b41a6 JG |
32960 | @node System-wide configuration |
32961 | @section System-wide configuration and settings | |
32962 | @cindex system-wide init file | |
32963 | ||
32964 | @value{GDBN} can be configured to have a system-wide init file; | |
32965 | this file will be read and executed at startup (@pxref{Startup, , What | |
32966 | @value{GDBN} does during startup}). | |
32967 | ||
32968 | Here is the corresponding configure option: | |
32969 | ||
32970 | @table @code | |
32971 | @item --with-system-gdbinit=@var{file} | |
32972 | Specify that the default location of the system-wide init file is | |
32973 | @var{file}. | |
32974 | @end table | |
32975 | ||
32976 | If @value{GDBN} has been configured with the option @option{--prefix=$prefix}, | |
32977 | it may be subject to relocation. Two possible cases: | |
32978 | ||
32979 | @itemize @bullet | |
32980 | @item | |
32981 | If the default location of this init file contains @file{$prefix}, | |
32982 | it will be subject to relocation. Suppose that the configure options | |
32983 | are @option{--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit}; | |
32984 | if @value{GDBN} is moved from @file{$prefix} to @file{$install}, the system | |
32985 | init file is looked for as @file{$install/etc/gdbinit} instead of | |
32986 | @file{$prefix/etc/gdbinit}. | |
32987 | ||
32988 | @item | |
32989 | By contrast, if the default location does not contain the prefix, | |
32990 | it will not be relocated. E.g.@: if @value{GDBN} has been configured with | |
32991 | @option{--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit}, | |
32992 | then @value{GDBN} will always look for @file{/usr/share/gdb/gdbinit}, | |
32993 | wherever @value{GDBN} is installed. | |
32994 | @end itemize | |
32995 | ||
e64e0392 DE |
32996 | If the configured location of the system-wide init file (as given by the |
32997 | @option{--with-system-gdbinit} option at configure time) is in the | |
32998 | data-directory (as specified by @option{--with-gdb-datadir} at configure | |
32999 | time) or in one of its subdirectories, then @value{GDBN} will look for the | |
33000 | system-wide init file in the directory specified by the | |
33001 | @option{--data-directory} command-line option. | |
33002 | Note that the system-wide init file is only read once, during @value{GDBN} | |
33003 | initialization. If the data-directory is changed after @value{GDBN} has | |
33004 | started with the @code{set data-directory} command, the file will not be | |
33005 | reread. | |
33006 | ||
5901af59 JB |
33007 | @menu |
33008 | * System-wide Configuration Scripts:: Installed System-wide Configuration Scripts | |
33009 | @end menu | |
33010 | ||
33011 | @node System-wide Configuration Scripts | |
0201faac JB |
33012 | @subsection Installed System-wide Configuration Scripts |
33013 | @cindex system-wide configuration scripts | |
33014 | ||
33015 | The @file{system-gdbinit} directory, located inside the data-directory | |
33016 | (as specified by @option{--with-gdb-datadir} at configure time) contains | |
33017 | a number of scripts which can be used as system-wide init files. To | |
33018 | automatically source those scripts at startup, @value{GDBN} should be | |
33019 | configured with @option{--with-system-gdbinit}. Otherwise, any user | |
33020 | should be able to source them by hand as needed. | |
33021 | ||
33022 | The following scripts are currently available: | |
33023 | @itemize @bullet | |
33024 | ||
33025 | @item @file{elinos.py} | |
33026 | @pindex elinos.py | |
33027 | @cindex ELinOS system-wide configuration script | |
33028 | This script is useful when debugging a program on an ELinOS target. | |
33029 | It takes advantage of the environment variables defined in a standard | |
33030 | ELinOS environment in order to determine the location of the system | |
33031 | shared libraries, and then sets the @samp{solib-absolute-prefix} | |
33032 | and @samp{solib-search-path} variables appropriately. | |
33033 | ||
33034 | @item @file{wrs-linux.py} | |
33035 | @pindex wrs-linux.py | |
33036 | @cindex Wind River Linux system-wide configuration script | |
33037 | This script is useful when debugging a program on a target running | |
33038 | Wind River Linux. It expects the @env{ENV_PREFIX} to be set to | |
33039 | the host-side sysroot used by the target system. | |
33040 | ||
33041 | @end itemize | |
33042 | ||
8e04817f AC |
33043 | @node Maintenance Commands |
33044 | @appendix Maintenance Commands | |
33045 | @cindex maintenance commands | |
33046 | @cindex internal commands | |
c906108c | 33047 | |
8e04817f | 33048 | In addition to commands intended for @value{GDBN} users, @value{GDBN} |
09d4efe1 EZ |
33049 | includes a number of commands intended for @value{GDBN} developers, |
33050 | that are not documented elsewhere in this manual. These commands are | |
da316a69 EZ |
33051 | provided here for reference. (For commands that turn on debugging |
33052 | messages, see @ref{Debugging Output}.) | |
c906108c | 33053 | |
8e04817f | 33054 | @table @code |
09d4efe1 | 33055 | @kindex maint agent |
782b2b07 | 33056 | @kindex maint agent-eval |
f77cc5f0 HZ |
33057 | @item maint agent @r{[}-at @var{location}@r{,}@r{]} @var{expression} |
33058 | @itemx maint agent-eval @r{[}-at @var{location}@r{,}@r{]} @var{expression} | |
09d4efe1 EZ |
33059 | Translate the given @var{expression} into remote agent bytecodes. |
33060 | This command is useful for debugging the Agent Expression mechanism | |
782b2b07 SS |
33061 | (@pxref{Agent Expressions}). The @samp{agent} version produces an |
33062 | expression useful for data collection, such as by tracepoints, while | |
33063 | @samp{maint agent-eval} produces an expression that evaluates directly | |
33064 | to a result. For instance, a collection expression for @code{globa + | |
33065 | globb} will include bytecodes to record four bytes of memory at each | |
33066 | of the addresses of @code{globa} and @code{globb}, while discarding | |
33067 | the result of the addition, while an evaluation expression will do the | |
33068 | addition and return the sum. | |
f77cc5f0 HZ |
33069 | If @code{-at} is given, generate remote agent bytecode for @var{location}. |
33070 | If not, generate remote agent bytecode for current frame PC address. | |
09d4efe1 | 33071 | |
d3ce09f5 SS |
33072 | @kindex maint agent-printf |
33073 | @item maint agent-printf @var{format},@var{expr},... | |
33074 | Translate the given format string and list of argument expressions | |
33075 | into remote agent bytecodes and display them as a disassembled list. | |
33076 | This command is useful for debugging the agent version of dynamic | |
6dd24dfa | 33077 | printf (@pxref{Dynamic Printf}). |
d3ce09f5 | 33078 | |
8e04817f AC |
33079 | @kindex maint info breakpoints |
33080 | @item @anchor{maint info breakpoints}maint info breakpoints | |
33081 | Using the same format as @samp{info breakpoints}, display both the | |
33082 | breakpoints you've set explicitly, and those @value{GDBN} is using for | |
33083 | internal purposes. Internal breakpoints are shown with negative | |
33084 | breakpoint numbers. The type column identifies what kind of breakpoint | |
33085 | is shown: | |
c906108c | 33086 | |
8e04817f AC |
33087 | @table @code |
33088 | @item breakpoint | |
33089 | Normal, explicitly set breakpoint. | |
c906108c | 33090 | |
8e04817f AC |
33091 | @item watchpoint |
33092 | Normal, explicitly set watchpoint. | |
c906108c | 33093 | |
8e04817f AC |
33094 | @item longjmp |
33095 | Internal breakpoint, used to handle correctly stepping through | |
33096 | @code{longjmp} calls. | |
c906108c | 33097 | |
8e04817f AC |
33098 | @item longjmp resume |
33099 | Internal breakpoint at the target of a @code{longjmp}. | |
c906108c | 33100 | |
8e04817f AC |
33101 | @item until |
33102 | Temporary internal breakpoint used by the @value{GDBN} @code{until} command. | |
c906108c | 33103 | |
8e04817f AC |
33104 | @item finish |
33105 | Temporary internal breakpoint used by the @value{GDBN} @code{finish} command. | |
c906108c | 33106 | |
8e04817f AC |
33107 | @item shlib events |
33108 | Shared library events. | |
c906108c | 33109 | |
8e04817f | 33110 | @end table |
c906108c | 33111 | |
d6b28940 TT |
33112 | @kindex maint info bfds |
33113 | @item maint info bfds | |
33114 | This prints information about each @code{bfd} object that is known to | |
33115 | @value{GDBN}. @xref{Top, , BFD, bfd, The Binary File Descriptor Library}. | |
33116 | ||
fff08868 HZ |
33117 | @kindex set displaced-stepping |
33118 | @kindex show displaced-stepping | |
237fc4c9 PA |
33119 | @cindex displaced stepping support |
33120 | @cindex out-of-line single-stepping | |
fff08868 HZ |
33121 | @item set displaced-stepping |
33122 | @itemx show displaced-stepping | |
237fc4c9 | 33123 | Control whether or not @value{GDBN} will do @dfn{displaced stepping} |
fff08868 HZ |
33124 | if the target supports it. Displaced stepping is a way to single-step |
33125 | over breakpoints without removing them from the inferior, by executing | |
33126 | an out-of-line copy of the instruction that was originally at the | |
33127 | breakpoint location. It is also known as out-of-line single-stepping. | |
33128 | ||
33129 | @table @code | |
33130 | @item set displaced-stepping on | |
33131 | If the target architecture supports it, @value{GDBN} will use | |
33132 | displaced stepping to step over breakpoints. | |
33133 | ||
33134 | @item set displaced-stepping off | |
33135 | @value{GDBN} will not use displaced stepping to step over breakpoints, | |
33136 | even if such is supported by the target architecture. | |
33137 | ||
33138 | @cindex non-stop mode, and @samp{set displaced-stepping} | |
33139 | @item set displaced-stepping auto | |
33140 | This is the default mode. @value{GDBN} will use displaced stepping | |
33141 | only if non-stop mode is active (@pxref{Non-Stop Mode}) and the target | |
33142 | architecture supports displaced stepping. | |
33143 | @end table | |
237fc4c9 | 33144 | |
7d0c9981 DE |
33145 | @kindex maint check-psymtabs |
33146 | @item maint check-psymtabs | |
33147 | Check the consistency of currently expanded psymtabs versus symtabs. | |
33148 | Use this to check, for example, whether a symbol is in one but not the other. | |
33149 | ||
09d4efe1 EZ |
33150 | @kindex maint check-symtabs |
33151 | @item maint check-symtabs | |
7d0c9981 DE |
33152 | Check the consistency of currently expanded symtabs. |
33153 | ||
33154 | @kindex maint expand-symtabs | |
33155 | @item maint expand-symtabs [@var{regexp}] | |
33156 | Expand symbol tables. | |
33157 | If @var{regexp} is specified, only expand symbol tables for file | |
33158 | names matching @var{regexp}. | |
09d4efe1 | 33159 | |
992c7d70 GB |
33160 | @kindex maint set catch-demangler-crashes |
33161 | @kindex maint show catch-demangler-crashes | |
33162 | @cindex demangler crashes | |
33163 | @item maint set catch-demangler-crashes [on|off] | |
33164 | @itemx maint show catch-demangler-crashes | |
33165 | Control whether @value{GDBN} should attempt to catch crashes in the | |
33166 | symbol name demangler. The default is to attempt to catch crashes. | |
33167 | If enabled, the first time a crash is caught, a core file is created, | |
33168 | the offending symbol is displayed and the user is presented with the | |
33169 | option to terminate the current session. | |
33170 | ||
09d4efe1 EZ |
33171 | @kindex maint cplus first_component |
33172 | @item maint cplus first_component @var{name} | |
33173 | Print the first C@t{++} class/namespace component of @var{name}. | |
33174 | ||
33175 | @kindex maint cplus namespace | |
33176 | @item maint cplus namespace | |
33177 | Print the list of possible C@t{++} namespaces. | |
33178 | ||
33179 | @kindex maint demangle | |
33180 | @item maint demangle @var{name} | |
d3e8051b | 33181 | Demangle a C@t{++} or Objective-C mangled @var{name}. |
09d4efe1 EZ |
33182 | |
33183 | @kindex maint deprecate | |
33184 | @kindex maint undeprecate | |
33185 | @cindex deprecated commands | |
33186 | @item maint deprecate @var{command} @r{[}@var{replacement}@r{]} | |
33187 | @itemx maint undeprecate @var{command} | |
33188 | Deprecate or undeprecate the named @var{command}. Deprecated commands | |
33189 | cause @value{GDBN} to issue a warning when you use them. The optional | |
33190 | argument @var{replacement} says which newer command should be used in | |
33191 | favor of the deprecated one; if it is given, @value{GDBN} will mention | |
33192 | the replacement as part of the warning. | |
33193 | ||
33194 | @kindex maint dump-me | |
33195 | @item maint dump-me | |
721c2651 | 33196 | @cindex @code{SIGQUIT} signal, dump core of @value{GDBN} |
09d4efe1 | 33197 | Cause a fatal signal in the debugger and force it to dump its core. |
721c2651 EZ |
33198 | This is supported only on systems which support aborting a program |
33199 | with the @code{SIGQUIT} signal. | |
09d4efe1 | 33200 | |
8d30a00d AC |
33201 | @kindex maint internal-error |
33202 | @kindex maint internal-warning | |
57fcfb1b GB |
33203 | @kindex maint demangler-warning |
33204 | @cindex demangler crashes | |
09d4efe1 EZ |
33205 | @item maint internal-error @r{[}@var{message-text}@r{]} |
33206 | @itemx maint internal-warning @r{[}@var{message-text}@r{]} | |
57fcfb1b GB |
33207 | @itemx maint demangler-warning @r{[}@var{message-text}@r{]} |
33208 | ||
33209 | Cause @value{GDBN} to call the internal function @code{internal_error}, | |
33210 | @code{internal_warning} or @code{demangler_warning} and hence behave | |
33211 | as though an internal problam has been detected. In addition to | |
33212 | reporting the internal problem, these functions give the user the | |
33213 | opportunity to either quit @value{GDBN} or (for @code{internal_error} | |
33214 | and @code{internal_warning}) create a core file of the current | |
8d30a00d AC |
33215 | @value{GDBN} session. |
33216 | ||
09d4efe1 EZ |
33217 | These commands take an optional parameter @var{message-text} that is |
33218 | used as the text of the error or warning message. | |
33219 | ||
d3e8051b | 33220 | Here's an example of using @code{internal-error}: |
09d4efe1 | 33221 | |
8d30a00d | 33222 | @smallexample |
f7dc1244 | 33223 | (@value{GDBP}) @kbd{maint internal-error testing, 1, 2} |
8d30a00d AC |
33224 | @dots{}/maint.c:121: internal-error: testing, 1, 2 |
33225 | A problem internal to GDB has been detected. Further | |
33226 | debugging may prove unreliable. | |
33227 | Quit this debugging session? (y or n) @kbd{n} | |
33228 | Create a core file? (y or n) @kbd{n} | |
f7dc1244 | 33229 | (@value{GDBP}) |
8d30a00d AC |
33230 | @end smallexample |
33231 | ||
3c16cced PA |
33232 | @cindex @value{GDBN} internal error |
33233 | @cindex internal errors, control of @value{GDBN} behavior | |
57fcfb1b | 33234 | @cindex demangler crashes |
3c16cced PA |
33235 | |
33236 | @kindex maint set internal-error | |
33237 | @kindex maint show internal-error | |
33238 | @kindex maint set internal-warning | |
33239 | @kindex maint show internal-warning | |
57fcfb1b GB |
33240 | @kindex maint set demangler-warning |
33241 | @kindex maint show demangler-warning | |
3c16cced PA |
33242 | @item maint set internal-error @var{action} [ask|yes|no] |
33243 | @itemx maint show internal-error @var{action} | |
33244 | @itemx maint set internal-warning @var{action} [ask|yes|no] | |
33245 | @itemx maint show internal-warning @var{action} | |
57fcfb1b GB |
33246 | @itemx maint set demangler-warning @var{action} [ask|yes|no] |
33247 | @itemx maint show demangler-warning @var{action} | |
3c16cced PA |
33248 | When @value{GDBN} reports an internal problem (error or warning) it |
33249 | gives the user the opportunity to both quit @value{GDBN} and create a | |
33250 | core file of the current @value{GDBN} session. These commands let you | |
33251 | override the default behaviour for each particular @var{action}, | |
33252 | described in the table below. | |
33253 | ||
33254 | @table @samp | |
33255 | @item quit | |
33256 | You can specify that @value{GDBN} should always (yes) or never (no) | |
33257 | quit. The default is to ask the user what to do. | |
33258 | ||
33259 | @item corefile | |
33260 | You can specify that @value{GDBN} should always (yes) or never (no) | |
57fcfb1b GB |
33261 | create a core file. The default is to ask the user what to do. Note |
33262 | that there is no @code{corefile} option for @code{demangler-warning}: | |
33263 | demangler warnings always create a core file and this cannot be | |
33264 | disabled. | |
3c16cced PA |
33265 | @end table |
33266 | ||
09d4efe1 EZ |
33267 | @kindex maint packet |
33268 | @item maint packet @var{text} | |
33269 | If @value{GDBN} is talking to an inferior via the serial protocol, | |
33270 | then this command sends the string @var{text} to the inferior, and | |
33271 | displays the response packet. @value{GDBN} supplies the initial | |
33272 | @samp{$} character, the terminating @samp{#} character, and the | |
33273 | checksum. | |
33274 | ||
33275 | @kindex maint print architecture | |
33276 | @item maint print architecture @r{[}@var{file}@r{]} | |
33277 | Print the entire architecture configuration. The optional argument | |
33278 | @var{file} names the file where the output goes. | |
8d30a00d | 33279 | |
81adfced DJ |
33280 | @kindex maint print c-tdesc |
33281 | @item maint print c-tdesc | |
33282 | Print the current target description (@pxref{Target Descriptions}) as | |
33283 | a C source file. The created source file can be used in @value{GDBN} | |
33284 | when an XML parser is not available to parse the description. | |
33285 | ||
00905d52 AC |
33286 | @kindex maint print dummy-frames |
33287 | @item maint print dummy-frames | |
00905d52 AC |
33288 | Prints the contents of @value{GDBN}'s internal dummy-frame stack. |
33289 | ||
33290 | @smallexample | |
f7dc1244 | 33291 | (@value{GDBP}) @kbd{b add} |
00905d52 | 33292 | @dots{} |
f7dc1244 | 33293 | (@value{GDBP}) @kbd{print add(2,3)} |
00905d52 AC |
33294 | Breakpoint 2, add (a=2, b=3) at @dots{} |
33295 | 58 return (a + b); | |
33296 | The program being debugged stopped while in a function called from GDB. | |
33297 | @dots{} | |
f7dc1244 | 33298 | (@value{GDBP}) @kbd{maint print dummy-frames} |
b67a2c6f | 33299 | 0xa8206d8: id=@{stack=0xbfffe734,code=0xbfffe73f,!special@}, ptid=process 9353 |
f7dc1244 | 33300 | (@value{GDBP}) |
00905d52 AC |
33301 | @end smallexample |
33302 | ||
33303 | Takes an optional file parameter. | |
33304 | ||
0680b120 AC |
33305 | @kindex maint print registers |
33306 | @kindex maint print raw-registers | |
33307 | @kindex maint print cooked-registers | |
617073a9 | 33308 | @kindex maint print register-groups |
c21236dc | 33309 | @kindex maint print remote-registers |
09d4efe1 EZ |
33310 | @item maint print registers @r{[}@var{file}@r{]} |
33311 | @itemx maint print raw-registers @r{[}@var{file}@r{]} | |
33312 | @itemx maint print cooked-registers @r{[}@var{file}@r{]} | |
33313 | @itemx maint print register-groups @r{[}@var{file}@r{]} | |
c21236dc | 33314 | @itemx maint print remote-registers @r{[}@var{file}@r{]} |
0680b120 AC |
33315 | Print @value{GDBN}'s internal register data structures. |
33316 | ||
617073a9 | 33317 | The command @code{maint print raw-registers} includes the contents of |
c21236dc PA |
33318 | the raw register cache; the command @code{maint print |
33319 | cooked-registers} includes the (cooked) value of all registers, | |
33320 | including registers which aren't available on the target nor visible | |
33321 | to user; the command @code{maint print register-groups} includes the | |
33322 | groups that each register is a member of; and the command @code{maint | |
33323 | print remote-registers} includes the remote target's register numbers | |
0a7cfe2c | 33324 | and offsets in the `G' packets. |
0680b120 | 33325 | |
09d4efe1 EZ |
33326 | These commands take an optional parameter, a file name to which to |
33327 | write the information. | |
0680b120 | 33328 | |
617073a9 | 33329 | @kindex maint print reggroups |
09d4efe1 EZ |
33330 | @item maint print reggroups @r{[}@var{file}@r{]} |
33331 | Print @value{GDBN}'s internal register group data structures. The | |
33332 | optional argument @var{file} tells to what file to write the | |
33333 | information. | |
617073a9 | 33334 | |
09d4efe1 | 33335 | The register groups info looks like this: |
617073a9 AC |
33336 | |
33337 | @smallexample | |
f7dc1244 | 33338 | (@value{GDBP}) @kbd{maint print reggroups} |
b383017d RM |
33339 | Group Type |
33340 | general user | |
33341 | float user | |
33342 | all user | |
33343 | vector user | |
33344 | system user | |
33345 | save internal | |
33346 | restore internal | |
617073a9 AC |
33347 | @end smallexample |
33348 | ||
09d4efe1 EZ |
33349 | @kindex flushregs |
33350 | @item flushregs | |
33351 | This command forces @value{GDBN} to flush its internal register cache. | |
33352 | ||
33353 | @kindex maint print objfiles | |
33354 | @cindex info for known object files | |
52e260a3 DE |
33355 | @item maint print objfiles @r{[}@var{regexp}@r{]} |
33356 | Print a dump of all known object files. | |
33357 | If @var{regexp} is specified, only print object files whose names | |
33358 | match @var{regexp}. For each object file, this command prints its name, | |
33359 | address in memory, and all of its psymtabs and symtabs. | |
09d4efe1 | 33360 | |
8a1ea21f DE |
33361 | @kindex maint print section-scripts |
33362 | @cindex info for known .debug_gdb_scripts-loaded scripts | |
33363 | @item maint print section-scripts [@var{regexp}] | |
33364 | Print a dump of scripts specified in the @code{.debug_gdb_section} section. | |
33365 | If @var{regexp} is specified, only print scripts loaded by object files | |
33366 | matching @var{regexp}. | |
33367 | For each script, this command prints its name as specified in the objfile, | |
33368 | and the full path if known. | |
8e0583c8 | 33369 | @xref{dotdebug_gdb_scripts section}. |
8a1ea21f | 33370 | |
09d4efe1 EZ |
33371 | @kindex maint print statistics |
33372 | @cindex bcache statistics | |
33373 | @item maint print statistics | |
33374 | This command prints, for each object file in the program, various data | |
33375 | about that object file followed by the byte cache (@dfn{bcache}) | |
33376 | statistics for the object file. The objfile data includes the number | |
d3e8051b | 33377 | of minimal, partial, full, and stabs symbols, the number of types |
09d4efe1 EZ |
33378 | defined by the objfile, the number of as yet unexpanded psym tables, |
33379 | the number of line tables and string tables, and the amount of memory | |
33380 | used by the various tables. The bcache statistics include the counts, | |
33381 | sizes, and counts of duplicates of all and unique objects, max, | |
33382 | average, and median entry size, total memory used and its overhead and | |
33383 | savings, and various measures of the hash table size and chain | |
33384 | lengths. | |
33385 | ||
c7ba131e JB |
33386 | @kindex maint print target-stack |
33387 | @cindex target stack description | |
33388 | @item maint print target-stack | |
33389 | A @dfn{target} is an interface between the debugger and a particular | |
33390 | kind of file or process. Targets can be stacked in @dfn{strata}, | |
33391 | so that more than one target can potentially respond to a request. | |
33392 | In particular, memory accesses will walk down the stack of targets | |
33393 | until they find a target that is interested in handling that particular | |
33394 | address. | |
33395 | ||
33396 | This command prints a short description of each layer that was pushed on | |
33397 | the @dfn{target stack}, starting from the top layer down to the bottom one. | |
33398 | ||
09d4efe1 EZ |
33399 | @kindex maint print type |
33400 | @cindex type chain of a data type | |
33401 | @item maint print type @var{expr} | |
33402 | Print the type chain for a type specified by @var{expr}. The argument | |
33403 | can be either a type name or a symbol. If it is a symbol, the type of | |
33404 | that symbol is described. The type chain produced by this command is | |
33405 | a recursive definition of the data type as stored in @value{GDBN}'s | |
33406 | data structures, including its flags and contained types. | |
33407 | ||
9eae7c52 TT |
33408 | @kindex maint set dwarf2 always-disassemble |
33409 | @kindex maint show dwarf2 always-disassemble | |
33410 | @item maint set dwarf2 always-disassemble | |
33411 | @item maint show dwarf2 always-disassemble | |
33412 | Control the behavior of @code{info address} when using DWARF debugging | |
33413 | information. | |
33414 | ||
33415 | The default is @code{off}, which means that @value{GDBN} should try to | |
33416 | describe a variable's location in an easily readable format. When | |
33417 | @code{on}, @value{GDBN} will instead display the DWARF location | |
33418 | expression in an assembly-like format. Note that some locations are | |
33419 | too complex for @value{GDBN} to describe simply; in this case you will | |
33420 | always see the disassembly form. | |
33421 | ||
33422 | Here is an example of the resulting disassembly: | |
33423 | ||
33424 | @smallexample | |
33425 | (gdb) info addr argc | |
33426 | Symbol "argc" is a complex DWARF expression: | |
33427 | 1: DW_OP_fbreg 0 | |
33428 | @end smallexample | |
33429 | ||
33430 | For more information on these expressions, see | |
33431 | @uref{http://www.dwarfstd.org/, the DWARF standard}. | |
33432 | ||
09d4efe1 EZ |
33433 | @kindex maint set dwarf2 max-cache-age |
33434 | @kindex maint show dwarf2 max-cache-age | |
33435 | @item maint set dwarf2 max-cache-age | |
33436 | @itemx maint show dwarf2 max-cache-age | |
33437 | Control the DWARF 2 compilation unit cache. | |
33438 | ||
33439 | @cindex DWARF 2 compilation units cache | |
33440 | In object files with inter-compilation-unit references, such as those | |
33441 | produced by the GCC option @samp{-feliminate-dwarf2-dups}, the DWARF 2 | |
33442 | reader needs to frequently refer to previously read compilation units. | |
33443 | This setting controls how long a compilation unit will remain in the | |
33444 | cache if it is not referenced. A higher limit means that cached | |
33445 | compilation units will be stored in memory longer, and more total | |
33446 | memory will be used. Setting it to zero disables caching, which will | |
33447 | slow down @value{GDBN} startup, but reduce memory consumption. | |
33448 | ||
e7ba9c65 DJ |
33449 | @kindex maint set profile |
33450 | @kindex maint show profile | |
33451 | @cindex profiling GDB | |
33452 | @item maint set profile | |
33453 | @itemx maint show profile | |
33454 | Control profiling of @value{GDBN}. | |
33455 | ||
33456 | Profiling will be disabled until you use the @samp{maint set profile} | |
33457 | command to enable it. When you enable profiling, the system will begin | |
33458 | collecting timing and execution count data; when you disable profiling or | |
33459 | exit @value{GDBN}, the results will be written to a log file. Remember that | |
33460 | if you use profiling, @value{GDBN} will overwrite the profiling log file | |
33461 | (often called @file{gmon.out}). If you have a record of important profiling | |
33462 | data in a @file{gmon.out} file, be sure to move it to a safe location. | |
33463 | ||
33464 | Configuring with @samp{--enable-profiling} arranges for @value{GDBN} to be | |
b383017d | 33465 | compiled with the @samp{-pg} compiler option. |
e7ba9c65 | 33466 | |
cbe54154 PA |
33467 | @kindex maint set show-debug-regs |
33468 | @kindex maint show show-debug-regs | |
eac35c4e | 33469 | @cindex hardware debug registers |
cbe54154 PA |
33470 | @item maint set show-debug-regs |
33471 | @itemx maint show show-debug-regs | |
eac35c4e | 33472 | Control whether to show variables that mirror the hardware debug |
6dd315ba | 33473 | registers. Use @code{on} to enable, @code{off} to disable. If |
3f94c067 | 33474 | enabled, the debug registers values are shown when @value{GDBN} inserts or |
09d4efe1 EZ |
33475 | removes a hardware breakpoint or watchpoint, and when the inferior |
33476 | triggers a hardware-assisted breakpoint or watchpoint. | |
33477 | ||
711e434b PM |
33478 | @kindex maint set show-all-tib |
33479 | @kindex maint show show-all-tib | |
33480 | @item maint set show-all-tib | |
33481 | @itemx maint show show-all-tib | |
33482 | Control whether to show all non zero areas within a 1k block starting | |
33483 | at thread local base, when using the @samp{info w32 thread-information-block} | |
33484 | command. | |
33485 | ||
329ea579 PA |
33486 | @kindex maint set target-async |
33487 | @kindex maint show target-async | |
33488 | @item maint set target-async | |
33489 | @itemx maint show target-async | |
33490 | This controls whether @value{GDBN} targets operate in synchronous or | |
33491 | asynchronous mode (@pxref{Background Execution}). Normally the | |
33492 | default is asynchronous, if it is available; but this can be changed | |
33493 | to more easily debug problems occurring only in synchronous mode. | |
33494 | ||
bd712aed DE |
33495 | @kindex maint set per-command |
33496 | @kindex maint show per-command | |
33497 | @item maint set per-command | |
33498 | @itemx maint show per-command | |
33499 | @cindex resources used by commands | |
09d4efe1 | 33500 | |
bd712aed DE |
33501 | @value{GDBN} can display the resources used by each command. |
33502 | This is useful in debugging performance problems. | |
33503 | ||
33504 | @table @code | |
33505 | @item maint set per-command space [on|off] | |
33506 | @itemx maint show per-command space | |
33507 | Enable or disable the printing of the memory used by GDB for each command. | |
33508 | If enabled, @value{GDBN} will display how much memory each command | |
33509 | took, following the command's own output. | |
33510 | This can also be requested by invoking @value{GDBN} with the | |
33511 | @option{--statistics} command-line switch (@pxref{Mode Options}). | |
33512 | ||
33513 | @item maint set per-command time [on|off] | |
33514 | @itemx maint show per-command time | |
33515 | Enable or disable the printing of the execution time of @value{GDBN} | |
33516 | for each command. | |
33517 | If enabled, @value{GDBN} will display how much time it | |
09d4efe1 | 33518 | took to execute each command, following the command's own output. |
0a1c4d10 DE |
33519 | Both CPU time and wallclock time are printed. |
33520 | Printing both is useful when trying to determine whether the cost is | |
bd712aed | 33521 | CPU or, e.g., disk/network latency. |
0a1c4d10 DE |
33522 | Note that the CPU time printed is for @value{GDBN} only, it does not include |
33523 | the execution time of the inferior because there's no mechanism currently | |
33524 | to compute how much time was spent by @value{GDBN} and how much time was | |
33525 | spent by the program been debugged. | |
09d4efe1 EZ |
33526 | This can also be requested by invoking @value{GDBN} with the |
33527 | @option{--statistics} command-line switch (@pxref{Mode Options}). | |
33528 | ||
bd712aed DE |
33529 | @item maint set per-command symtab [on|off] |
33530 | @itemx maint show per-command symtab | |
33531 | Enable or disable the printing of basic symbol table statistics | |
33532 | for each command. | |
33533 | If enabled, @value{GDBN} will display the following information: | |
33534 | ||
215b9f98 EZ |
33535 | @enumerate a |
33536 | @item | |
33537 | number of symbol tables | |
33538 | @item | |
33539 | number of primary symbol tables | |
33540 | @item | |
33541 | number of blocks in the blockvector | |
33542 | @end enumerate | |
bd712aed DE |
33543 | @end table |
33544 | ||
33545 | @kindex maint space | |
33546 | @cindex memory used by commands | |
33547 | @item maint space @var{value} | |
33548 | An alias for @code{maint set per-command space}. | |
33549 | A non-zero value enables it, zero disables it. | |
33550 | ||
33551 | @kindex maint time | |
33552 | @cindex time of command execution | |
33553 | @item maint time @var{value} | |
33554 | An alias for @code{maint set per-command time}. | |
33555 | A non-zero value enables it, zero disables it. | |
33556 | ||
09d4efe1 EZ |
33557 | @kindex maint translate-address |
33558 | @item maint translate-address @r{[}@var{section}@r{]} @var{addr} | |
33559 | Find the symbol stored at the location specified by the address | |
33560 | @var{addr} and an optional section name @var{section}. If found, | |
33561 | @value{GDBN} prints the name of the closest symbol and an offset from | |
33562 | the symbol's location to the specified address. This is similar to | |
33563 | the @code{info address} command (@pxref{Symbols}), except that this | |
33564 | command also allows to find symbols in other sections. | |
ae038cb0 | 33565 | |
c14c28ba PP |
33566 | If section was not specified, the section in which the symbol was found |
33567 | is also printed. For dynamically linked executables, the name of | |
33568 | executable or shared library containing the symbol is printed as well. | |
33569 | ||
8e04817f | 33570 | @end table |
c906108c | 33571 | |
9c16f35a EZ |
33572 | The following command is useful for non-interactive invocations of |
33573 | @value{GDBN}, such as in the test suite. | |
33574 | ||
33575 | @table @code | |
33576 | @item set watchdog @var{nsec} | |
33577 | @kindex set watchdog | |
33578 | @cindex watchdog timer | |
33579 | @cindex timeout for commands | |
33580 | Set the maximum number of seconds @value{GDBN} will wait for the | |
33581 | target operation to finish. If this time expires, @value{GDBN} | |
33582 | reports and error and the command is aborted. | |
33583 | ||
33584 | @item show watchdog | |
33585 | Show the current setting of the target wait timeout. | |
33586 | @end table | |
c906108c | 33587 | |
e0ce93ac | 33588 | @node Remote Protocol |
8e04817f | 33589 | @appendix @value{GDBN} Remote Serial Protocol |
c906108c | 33590 | |
ee2d5c50 AC |
33591 | @menu |
33592 | * Overview:: | |
33593 | * Packets:: | |
33594 | * Stop Reply Packets:: | |
33595 | * General Query Packets:: | |
a1dcb23a | 33596 | * Architecture-Specific Protocol Details:: |
9d29849a | 33597 | * Tracepoint Packets:: |
a6b151f1 | 33598 | * Host I/O Packets:: |
9a6253be | 33599 | * Interrupts:: |
8b23ecc4 SL |
33600 | * Notification Packets:: |
33601 | * Remote Non-Stop:: | |
a6f3e723 | 33602 | * Packet Acknowledgment:: |
ee2d5c50 | 33603 | * Examples:: |
79a6e687 | 33604 | * File-I/O Remote Protocol Extension:: |
cfa9d6d9 | 33605 | * Library List Format:: |
2268b414 | 33606 | * Library List Format for SVR4 Targets:: |
79a6e687 | 33607 | * Memory Map Format:: |
dc146f7c | 33608 | * Thread List Format:: |
b3b9301e | 33609 | * Traceframe Info Format:: |
2ae8c8e7 | 33610 | * Branch Trace Format:: |
ee2d5c50 AC |
33611 | @end menu |
33612 | ||
33613 | @node Overview | |
33614 | @section Overview | |
33615 | ||
8e04817f AC |
33616 | There may be occasions when you need to know something about the |
33617 | protocol---for example, if there is only one serial port to your target | |
33618 | machine, you might want your program to do something special if it | |
33619 | recognizes a packet meant for @value{GDBN}. | |
c906108c | 33620 | |
d2c6833e | 33621 | In the examples below, @samp{->} and @samp{<-} are used to indicate |
bf06d120 | 33622 | transmitted and received data, respectively. |
c906108c | 33623 | |
8e04817f AC |
33624 | @cindex protocol, @value{GDBN} remote serial |
33625 | @cindex serial protocol, @value{GDBN} remote | |
33626 | @cindex remote serial protocol | |
8b23ecc4 SL |
33627 | All @value{GDBN} commands and responses (other than acknowledgments |
33628 | and notifications, see @ref{Notification Packets}) are sent as a | |
33629 | @var{packet}. A @var{packet} is introduced with the character | |
8e04817f AC |
33630 | @samp{$}, the actual @var{packet-data}, and the terminating character |
33631 | @samp{#} followed by a two-digit @var{checksum}: | |
c906108c | 33632 | |
474c8240 | 33633 | @smallexample |
8e04817f | 33634 | @code{$}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 33635 | @end smallexample |
8e04817f | 33636 | @noindent |
c906108c | 33637 | |
8e04817f AC |
33638 | @cindex checksum, for @value{GDBN} remote |
33639 | @noindent | |
33640 | The two-digit @var{checksum} is computed as the modulo 256 sum of all | |
33641 | characters between the leading @samp{$} and the trailing @samp{#} (an | |
33642 | eight bit unsigned checksum). | |
c906108c | 33643 | |
8e04817f AC |
33644 | Implementors should note that prior to @value{GDBN} 5.0 the protocol |
33645 | specification also included an optional two-digit @var{sequence-id}: | |
c906108c | 33646 | |
474c8240 | 33647 | @smallexample |
8e04817f | 33648 | @code{$}@var{sequence-id}@code{:}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 33649 | @end smallexample |
c906108c | 33650 | |
8e04817f AC |
33651 | @cindex sequence-id, for @value{GDBN} remote |
33652 | @noindent | |
33653 | That @var{sequence-id} was appended to the acknowledgment. @value{GDBN} | |
33654 | has never output @var{sequence-id}s. Stubs that handle packets added | |
33655 | since @value{GDBN} 5.0 must not accept @var{sequence-id}. | |
c906108c | 33656 | |
8e04817f AC |
33657 | When either the host or the target machine receives a packet, the first |
33658 | response expected is an acknowledgment: either @samp{+} (to indicate | |
33659 | the package was received correctly) or @samp{-} (to request | |
33660 | retransmission): | |
c906108c | 33661 | |
474c8240 | 33662 | @smallexample |
d2c6833e AC |
33663 | -> @code{$}@var{packet-data}@code{#}@var{checksum} |
33664 | <- @code{+} | |
474c8240 | 33665 | @end smallexample |
8e04817f | 33666 | @noindent |
53a5351d | 33667 | |
a6f3e723 SL |
33668 | The @samp{+}/@samp{-} acknowledgments can be disabled |
33669 | once a connection is established. | |
33670 | @xref{Packet Acknowledgment}, for details. | |
33671 | ||
8e04817f AC |
33672 | The host (@value{GDBN}) sends @var{command}s, and the target (the |
33673 | debugging stub incorporated in your program) sends a @var{response}. In | |
33674 | the case of step and continue @var{command}s, the response is only sent | |
8b23ecc4 SL |
33675 | when the operation has completed, and the target has again stopped all |
33676 | threads in all attached processes. This is the default all-stop mode | |
33677 | behavior, but the remote protocol also supports @value{GDBN}'s non-stop | |
33678 | execution mode; see @ref{Remote Non-Stop}, for details. | |
c906108c | 33679 | |
8e04817f AC |
33680 | @var{packet-data} consists of a sequence of characters with the |
33681 | exception of @samp{#} and @samp{$} (see @samp{X} packet for additional | |
33682 | exceptions). | |
c906108c | 33683 | |
ee2d5c50 | 33684 | @cindex remote protocol, field separator |
0876f84a | 33685 | Fields within the packet should be separated using @samp{,} @samp{;} or |
8e04817f | 33686 | @samp{:}. Except where otherwise noted all numbers are represented in |
ee2d5c50 | 33687 | @sc{hex} with leading zeros suppressed. |
c906108c | 33688 | |
8e04817f AC |
33689 | Implementors should note that prior to @value{GDBN} 5.0, the character |
33690 | @samp{:} could not appear as the third character in a packet (as it | |
33691 | would potentially conflict with the @var{sequence-id}). | |
c906108c | 33692 | |
0876f84a DJ |
33693 | @cindex remote protocol, binary data |
33694 | @anchor{Binary Data} | |
33695 | Binary data in most packets is encoded either as two hexadecimal | |
33696 | digits per byte of binary data. This allowed the traditional remote | |
33697 | protocol to work over connections which were only seven-bit clean. | |
33698 | Some packets designed more recently assume an eight-bit clean | |
33699 | connection, and use a more efficient encoding to send and receive | |
33700 | binary data. | |
33701 | ||
33702 | The binary data representation uses @code{7d} (@sc{ascii} @samp{@}}) | |
33703 | as an escape character. Any escaped byte is transmitted as the escape | |
33704 | character followed by the original character XORed with @code{0x20}. | |
33705 | For example, the byte @code{0x7d} would be transmitted as the two | |
33706 | bytes @code{0x7d 0x5d}. The bytes @code{0x23} (@sc{ascii} @samp{#}), | |
33707 | @code{0x24} (@sc{ascii} @samp{$}), and @code{0x7d} (@sc{ascii} | |
33708 | @samp{@}}) must always be escaped. Responses sent by the stub | |
33709 | must also escape @code{0x2a} (@sc{ascii} @samp{*}), so that it | |
33710 | is not interpreted as the start of a run-length encoded sequence | |
33711 | (described next). | |
33712 | ||
1d3811f6 DJ |
33713 | Response @var{data} can be run-length encoded to save space. |
33714 | Run-length encoding replaces runs of identical characters with one | |
33715 | instance of the repeated character, followed by a @samp{*} and a | |
33716 | repeat count. The repeat count is itself sent encoded, to avoid | |
33717 | binary characters in @var{data}: a value of @var{n} is sent as | |
33718 | @code{@var{n}+29}. For a repeat count greater or equal to 3, this | |
33719 | produces a printable @sc{ascii} character, e.g.@: a space (@sc{ascii} | |
33720 | code 32) for a repeat count of 3. (This is because run-length | |
33721 | encoding starts to win for counts 3 or more.) Thus, for example, | |
33722 | @samp{0* } is a run-length encoding of ``0000'': the space character | |
33723 | after @samp{*} means repeat the leading @code{0} @w{@code{32 - 29 = | |
33724 | 3}} more times. | |
33725 | ||
33726 | The printable characters @samp{#} and @samp{$} or with a numeric value | |
33727 | greater than 126 must not be used. Runs of six repeats (@samp{#}) or | |
33728 | seven repeats (@samp{$}) can be expanded using a repeat count of only | |
33729 | five (@samp{"}). For example, @samp{00000000} can be encoded as | |
33730 | @samp{0*"00}. | |
c906108c | 33731 | |
8e04817f AC |
33732 | The error response returned for some packets includes a two character |
33733 | error number. That number is not well defined. | |
c906108c | 33734 | |
f8da2bff | 33735 | @cindex empty response, for unsupported packets |
8e04817f AC |
33736 | For any @var{command} not supported by the stub, an empty response |
33737 | (@samp{$#00}) should be returned. That way it is possible to extend the | |
33738 | protocol. A newer @value{GDBN} can tell if a packet is supported based | |
33739 | on that response. | |
c906108c | 33740 | |
393eab54 PA |
33741 | At a minimum, a stub is required to support the @samp{g} and @samp{G} |
33742 | commands for register access, and the @samp{m} and @samp{M} commands | |
33743 | for memory access. Stubs that only control single-threaded targets | |
33744 | can implement run control with the @samp{c} (continue), and @samp{s} | |
33745 | (step) commands. Stubs that support multi-threading targets should | |
33746 | support the @samp{vCont} command. All other commands are optional. | |
c906108c | 33747 | |
ee2d5c50 AC |
33748 | @node Packets |
33749 | @section Packets | |
33750 | ||
33751 | The following table provides a complete list of all currently defined | |
33752 | @var{command}s and their corresponding response @var{data}. | |
79a6e687 | 33753 | @xref{File-I/O Remote Protocol Extension}, for details about the File |
9c16f35a | 33754 | I/O extension of the remote protocol. |
ee2d5c50 | 33755 | |
b8ff78ce JB |
33756 | Each packet's description has a template showing the packet's overall |
33757 | syntax, followed by an explanation of the packet's meaning. We | |
33758 | include spaces in some of the templates for clarity; these are not | |
33759 | part of the packet's syntax. No @value{GDBN} packet uses spaces to | |
33760 | separate its components. For example, a template like @samp{foo | |
33761 | @var{bar} @var{baz}} describes a packet beginning with the three ASCII | |
33762 | bytes @samp{foo}, followed by a @var{bar}, followed directly by a | |
3f94c067 | 33763 | @var{baz}. @value{GDBN} does not transmit a space character between the |
b8ff78ce JB |
33764 | @samp{foo} and the @var{bar}, or between the @var{bar} and the |
33765 | @var{baz}. | |
33766 | ||
b90a069a SL |
33767 | @cindex @var{thread-id}, in remote protocol |
33768 | @anchor{thread-id syntax} | |
33769 | Several packets and replies include a @var{thread-id} field to identify | |
33770 | a thread. Normally these are positive numbers with a target-specific | |
33771 | interpretation, formatted as big-endian hex strings. A @var{thread-id} | |
33772 | can also be a literal @samp{-1} to indicate all threads, or @samp{0} to | |
33773 | pick any thread. | |
33774 | ||
33775 | In addition, the remote protocol supports a multiprocess feature in | |
33776 | which the @var{thread-id} syntax is extended to optionally include both | |
33777 | process and thread ID fields, as @samp{p@var{pid}.@var{tid}}. | |
33778 | The @var{pid} (process) and @var{tid} (thread) components each have the | |
33779 | format described above: a positive number with target-specific | |
33780 | interpretation formatted as a big-endian hex string, literal @samp{-1} | |
33781 | to indicate all processes or threads (respectively), or @samp{0} to | |
33782 | indicate an arbitrary process or thread. Specifying just a process, as | |
33783 | @samp{p@var{pid}}, is equivalent to @samp{p@var{pid}.-1}. It is an | |
33784 | error to specify all processes but a specific thread, such as | |
33785 | @samp{p-1.@var{tid}}. Note that the @samp{p} prefix is @emph{not} used | |
33786 | for those packets and replies explicitly documented to include a process | |
33787 | ID, rather than a @var{thread-id}. | |
33788 | ||
33789 | The multiprocess @var{thread-id} syntax extensions are only used if both | |
33790 | @value{GDBN} and the stub report support for the @samp{multiprocess} | |
33791 | feature using @samp{qSupported}. @xref{multiprocess extensions}, for | |
33792 | more information. | |
33793 | ||
8ffe2530 JB |
33794 | Note that all packet forms beginning with an upper- or lower-case |
33795 | letter, other than those described here, are reserved for future use. | |
33796 | ||
b8ff78ce | 33797 | Here are the packet descriptions. |
ee2d5c50 | 33798 | |
b8ff78ce | 33799 | @table @samp |
ee2d5c50 | 33800 | |
b8ff78ce JB |
33801 | @item ! |
33802 | @cindex @samp{!} packet | |
2d717e4f | 33803 | @anchor{extended mode} |
8e04817f AC |
33804 | Enable extended mode. In extended mode, the remote server is made |
33805 | persistent. The @samp{R} packet is used to restart the program being | |
33806 | debugged. | |
ee2d5c50 AC |
33807 | |
33808 | Reply: | |
33809 | @table @samp | |
33810 | @item OK | |
8e04817f | 33811 | The remote target both supports and has enabled extended mode. |
ee2d5c50 | 33812 | @end table |
c906108c | 33813 | |
b8ff78ce JB |
33814 | @item ? |
33815 | @cindex @samp{?} packet | |
36cb1214 | 33816 | @anchor{? packet} |
ee2d5c50 | 33817 | Indicate the reason the target halted. The reply is the same as for |
8b23ecc4 SL |
33818 | step and continue. This packet has a special interpretation when the |
33819 | target is in non-stop mode; see @ref{Remote Non-Stop}. | |
c906108c | 33820 | |
ee2d5c50 AC |
33821 | Reply: |
33822 | @xref{Stop Reply Packets}, for the reply specifications. | |
33823 | ||
b8ff78ce JB |
33824 | @item A @var{arglen},@var{argnum},@var{arg},@dots{} |
33825 | @cindex @samp{A} packet | |
33826 | Initialized @code{argv[]} array passed into program. @var{arglen} | |
33827 | specifies the number of bytes in the hex encoded byte stream | |
33828 | @var{arg}. See @code{gdbserver} for more details. | |
ee2d5c50 AC |
33829 | |
33830 | Reply: | |
33831 | @table @samp | |
33832 | @item OK | |
b8ff78ce JB |
33833 | The arguments were set. |
33834 | @item E @var{NN} | |
33835 | An error occurred. | |
ee2d5c50 AC |
33836 | @end table |
33837 | ||
b8ff78ce JB |
33838 | @item b @var{baud} |
33839 | @cindex @samp{b} packet | |
33840 | (Don't use this packet; its behavior is not well-defined.) | |
ee2d5c50 AC |
33841 | Change the serial line speed to @var{baud}. |
33842 | ||
33843 | JTC: @emph{When does the transport layer state change? When it's | |
33844 | received, or after the ACK is transmitted. In either case, there are | |
33845 | problems if the command or the acknowledgment packet is dropped.} | |
33846 | ||
33847 | Stan: @emph{If people really wanted to add something like this, and get | |
33848 | it working for the first time, they ought to modify ser-unix.c to send | |
33849 | some kind of out-of-band message to a specially-setup stub and have the | |
33850 | switch happen "in between" packets, so that from remote protocol's point | |
33851 | of view, nothing actually happened.} | |
33852 | ||
b8ff78ce JB |
33853 | @item B @var{addr},@var{mode} |
33854 | @cindex @samp{B} packet | |
8e04817f | 33855 | Set (@var{mode} is @samp{S}) or clear (@var{mode} is @samp{C}) a |
2f870471 AC |
33856 | breakpoint at @var{addr}. |
33857 | ||
b8ff78ce | 33858 | Don't use this packet. Use the @samp{Z} and @samp{z} packets instead |
2f870471 | 33859 | (@pxref{insert breakpoint or watchpoint packet}). |
c906108c | 33860 | |
bacec72f | 33861 | @cindex @samp{bc} packet |
0d772ac9 MS |
33862 | @anchor{bc} |
33863 | @item bc | |
bacec72f MS |
33864 | Backward continue. Execute the target system in reverse. No parameter. |
33865 | @xref{Reverse Execution}, for more information. | |
33866 | ||
33867 | Reply: | |
33868 | @xref{Stop Reply Packets}, for the reply specifications. | |
33869 | ||
bacec72f | 33870 | @cindex @samp{bs} packet |
0d772ac9 MS |
33871 | @anchor{bs} |
33872 | @item bs | |
bacec72f MS |
33873 | Backward single step. Execute one instruction in reverse. No parameter. |
33874 | @xref{Reverse Execution}, for more information. | |
33875 | ||
33876 | Reply: | |
33877 | @xref{Stop Reply Packets}, for the reply specifications. | |
33878 | ||
4f553f88 | 33879 | @item c @r{[}@var{addr}@r{]} |
b8ff78ce | 33880 | @cindex @samp{c} packet |
697aa1b7 EZ |
33881 | Continue at @var{addr}, which is the address to resume. If @var{addr} |
33882 | is omitted, resume at current address. | |
c906108c | 33883 | |
393eab54 PA |
33884 | This packet is deprecated for multi-threading support. @xref{vCont |
33885 | packet}. | |
33886 | ||
ee2d5c50 AC |
33887 | Reply: |
33888 | @xref{Stop Reply Packets}, for the reply specifications. | |
33889 | ||
4f553f88 | 33890 | @item C @var{sig}@r{[};@var{addr}@r{]} |
b8ff78ce | 33891 | @cindex @samp{C} packet |
8e04817f | 33892 | Continue with signal @var{sig} (hex signal number). If |
b8ff78ce | 33893 | @samp{;@var{addr}} is omitted, resume at same address. |
c906108c | 33894 | |
393eab54 PA |
33895 | This packet is deprecated for multi-threading support. @xref{vCont |
33896 | packet}. | |
33897 | ||
ee2d5c50 AC |
33898 | Reply: |
33899 | @xref{Stop Reply Packets}, for the reply specifications. | |
c906108c | 33900 | |
b8ff78ce JB |
33901 | @item d |
33902 | @cindex @samp{d} packet | |
ee2d5c50 AC |
33903 | Toggle debug flag. |
33904 | ||
b8ff78ce JB |
33905 | Don't use this packet; instead, define a general set packet |
33906 | (@pxref{General Query Packets}). | |
ee2d5c50 | 33907 | |
b8ff78ce | 33908 | @item D |
b90a069a | 33909 | @itemx D;@var{pid} |
b8ff78ce | 33910 | @cindex @samp{D} packet |
b90a069a SL |
33911 | The first form of the packet is used to detach @value{GDBN} from the |
33912 | remote system. It is sent to the remote target | |
07f31aa6 | 33913 | before @value{GDBN} disconnects via the @code{detach} command. |
ee2d5c50 | 33914 | |
b90a069a SL |
33915 | The second form, including a process ID, is used when multiprocess |
33916 | protocol extensions are enabled (@pxref{multiprocess extensions}), to | |
33917 | detach only a specific process. The @var{pid} is specified as a | |
33918 | big-endian hex string. | |
33919 | ||
ee2d5c50 AC |
33920 | Reply: |
33921 | @table @samp | |
10fac096 NW |
33922 | @item OK |
33923 | for success | |
b8ff78ce | 33924 | @item E @var{NN} |
10fac096 | 33925 | for an error |
ee2d5c50 | 33926 | @end table |
c906108c | 33927 | |
b8ff78ce JB |
33928 | @item F @var{RC},@var{EE},@var{CF};@var{XX} |
33929 | @cindex @samp{F} packet | |
33930 | A reply from @value{GDBN} to an @samp{F} packet sent by the target. | |
33931 | This is part of the File-I/O protocol extension. @xref{File-I/O | |
79a6e687 | 33932 | Remote Protocol Extension}, for the specification. |
ee2d5c50 | 33933 | |
b8ff78ce | 33934 | @item g |
ee2d5c50 | 33935 | @anchor{read registers packet} |
b8ff78ce | 33936 | @cindex @samp{g} packet |
ee2d5c50 AC |
33937 | Read general registers. |
33938 | ||
33939 | Reply: | |
33940 | @table @samp | |
33941 | @item @var{XX@dots{}} | |
8e04817f AC |
33942 | Each byte of register data is described by two hex digits. The bytes |
33943 | with the register are transmitted in target byte order. The size of | |
b8ff78ce | 33944 | each register and their position within the @samp{g} packet are |
4a9bb1df UW |
33945 | determined by the @value{GDBN} internal gdbarch functions |
33946 | @code{DEPRECATED_REGISTER_RAW_SIZE} and @code{gdbarch_register_name}. The | |
b8ff78ce | 33947 | specification of several standard @samp{g} packets is specified below. |
ad196637 PA |
33948 | |
33949 | When reading registers from a trace frame (@pxref{Analyze Collected | |
33950 | Data,,Using the Collected Data}), the stub may also return a string of | |
33951 | literal @samp{x}'s in place of the register data digits, to indicate | |
33952 | that the corresponding register has not been collected, thus its value | |
33953 | is unavailable. For example, for an architecture with 4 registers of | |
33954 | 4 bytes each, the following reply indicates to @value{GDBN} that | |
33955 | registers 0 and 2 have not been collected, while registers 1 and 3 | |
33956 | have been collected, and both have zero value: | |
33957 | ||
33958 | @smallexample | |
33959 | -> @code{g} | |
33960 | <- @code{xxxxxxxx00000000xxxxxxxx00000000} | |
33961 | @end smallexample | |
33962 | ||
b8ff78ce | 33963 | @item E @var{NN} |
ee2d5c50 AC |
33964 | for an error. |
33965 | @end table | |
c906108c | 33966 | |
b8ff78ce JB |
33967 | @item G @var{XX@dots{}} |
33968 | @cindex @samp{G} packet | |
33969 | Write general registers. @xref{read registers packet}, for a | |
33970 | description of the @var{XX@dots{}} data. | |
ee2d5c50 AC |
33971 | |
33972 | Reply: | |
33973 | @table @samp | |
33974 | @item OK | |
33975 | for success | |
b8ff78ce | 33976 | @item E @var{NN} |
ee2d5c50 AC |
33977 | for an error |
33978 | @end table | |
33979 | ||
393eab54 | 33980 | @item H @var{op} @var{thread-id} |
b8ff78ce | 33981 | @cindex @samp{H} packet |
8e04817f | 33982 | Set thread for subsequent operations (@samp{m}, @samp{M}, @samp{g}, |
697aa1b7 EZ |
33983 | @samp{G}, et.al.). Depending on the operation to be performed, @var{op} |
33984 | should be @samp{c} for step and continue operations (note that this | |
393eab54 | 33985 | is deprecated, supporting the @samp{vCont} command is a better |
697aa1b7 | 33986 | option), and @samp{g} for other operations. The thread designator |
393eab54 PA |
33987 | @var{thread-id} has the format and interpretation described in |
33988 | @ref{thread-id syntax}. | |
ee2d5c50 AC |
33989 | |
33990 | Reply: | |
33991 | @table @samp | |
33992 | @item OK | |
33993 | for success | |
b8ff78ce | 33994 | @item E @var{NN} |
ee2d5c50 AC |
33995 | for an error |
33996 | @end table | |
c906108c | 33997 | |
8e04817f AC |
33998 | @c FIXME: JTC: |
33999 | @c 'H': How restrictive (or permissive) is the thread model. If a | |
34000 | @c thread is selected and stopped, are other threads allowed | |
34001 | @c to continue to execute? As I mentioned above, I think the | |
34002 | @c semantics of each command when a thread is selected must be | |
34003 | @c described. For example: | |
34004 | @c | |
34005 | @c 'g': If the stub supports threads and a specific thread is | |
34006 | @c selected, returns the register block from that thread; | |
34007 | @c otherwise returns current registers. | |
34008 | @c | |
34009 | @c 'G' If the stub supports threads and a specific thread is | |
34010 | @c selected, sets the registers of the register block of | |
34011 | @c that thread; otherwise sets current registers. | |
c906108c | 34012 | |
b8ff78ce | 34013 | @item i @r{[}@var{addr}@r{[},@var{nnn}@r{]]} |
ee2d5c50 | 34014 | @anchor{cycle step packet} |
b8ff78ce JB |
34015 | @cindex @samp{i} packet |
34016 | Step the remote target by a single clock cycle. If @samp{,@var{nnn}} is | |
8e04817f AC |
34017 | present, cycle step @var{nnn} cycles. If @var{addr} is present, cycle |
34018 | step starting at that address. | |
c906108c | 34019 | |
b8ff78ce JB |
34020 | @item I |
34021 | @cindex @samp{I} packet | |
34022 | Signal, then cycle step. @xref{step with signal packet}. @xref{cycle | |
34023 | step packet}. | |
ee2d5c50 | 34024 | |
b8ff78ce JB |
34025 | @item k |
34026 | @cindex @samp{k} packet | |
34027 | Kill request. | |
c906108c | 34028 | |
36cb1214 HZ |
34029 | The exact effect of this packet is not specified. |
34030 | ||
34031 | For a bare-metal target, it may power cycle or reset the target | |
34032 | system. For that reason, the @samp{k} packet has no reply. | |
34033 | ||
34034 | For a single-process target, it may kill that process if possible. | |
34035 | ||
34036 | A multiple-process target may choose to kill just one process, or all | |
34037 | that are under @value{GDBN}'s control. For more precise control, use | |
34038 | the vKill packet (@pxref{vKill packet}). | |
34039 | ||
34040 | If the target system immediately closes the connection in response to | |
34041 | @samp{k}, @value{GDBN} does not consider the lack of packet | |
34042 | acknowledgment to be an error, and assumes the kill was successful. | |
34043 | ||
34044 | If connected using @kbd{target extended-remote}, and the target does | |
34045 | not close the connection in response to a kill request, @value{GDBN} | |
34046 | probes the target state as if a new connection was opened | |
34047 | (@pxref{? packet}). | |
c906108c | 34048 | |
b8ff78ce JB |
34049 | @item m @var{addr},@var{length} |
34050 | @cindex @samp{m} packet | |
8e04817f | 34051 | Read @var{length} bytes of memory starting at address @var{addr}. |
fb031cdf JB |
34052 | Note that @var{addr} may not be aligned to any particular boundary. |
34053 | ||
34054 | The stub need not use any particular size or alignment when gathering | |
34055 | data from memory for the response; even if @var{addr} is word-aligned | |
34056 | and @var{length} is a multiple of the word size, the stub is free to | |
34057 | use byte accesses, or not. For this reason, this packet may not be | |
34058 | suitable for accessing memory-mapped I/O devices. | |
c43c5473 JB |
34059 | @cindex alignment of remote memory accesses |
34060 | @cindex size of remote memory accesses | |
34061 | @cindex memory, alignment and size of remote accesses | |
c906108c | 34062 | |
ee2d5c50 AC |
34063 | Reply: |
34064 | @table @samp | |
34065 | @item @var{XX@dots{}} | |
599b237a | 34066 | Memory contents; each byte is transmitted as a two-digit hexadecimal |
b8ff78ce JB |
34067 | number. The reply may contain fewer bytes than requested if the |
34068 | server was able to read only part of the region of memory. | |
34069 | @item E @var{NN} | |
ee2d5c50 AC |
34070 | @var{NN} is errno |
34071 | @end table | |
34072 | ||
b8ff78ce JB |
34073 | @item M @var{addr},@var{length}:@var{XX@dots{}} |
34074 | @cindex @samp{M} packet | |
8e04817f | 34075 | Write @var{length} bytes of memory starting at address @var{addr}. |
697aa1b7 | 34076 | The data is given by @var{XX@dots{}}; each byte is transmitted as a two-digit |
599b237a | 34077 | hexadecimal number. |
ee2d5c50 AC |
34078 | |
34079 | Reply: | |
34080 | @table @samp | |
34081 | @item OK | |
34082 | for success | |
b8ff78ce | 34083 | @item E @var{NN} |
8e04817f AC |
34084 | for an error (this includes the case where only part of the data was |
34085 | written). | |
ee2d5c50 | 34086 | @end table |
c906108c | 34087 | |
b8ff78ce JB |
34088 | @item p @var{n} |
34089 | @cindex @samp{p} packet | |
34090 | Read the value of register @var{n}; @var{n} is in hex. | |
2e868123 AC |
34091 | @xref{read registers packet}, for a description of how the returned |
34092 | register value is encoded. | |
ee2d5c50 AC |
34093 | |
34094 | Reply: | |
34095 | @table @samp | |
2e868123 AC |
34096 | @item @var{XX@dots{}} |
34097 | the register's value | |
b8ff78ce | 34098 | @item E @var{NN} |
2e868123 | 34099 | for an error |
d57350ea | 34100 | @item @w{} |
2e868123 | 34101 | Indicating an unrecognized @var{query}. |
ee2d5c50 AC |
34102 | @end table |
34103 | ||
b8ff78ce | 34104 | @item P @var{n@dots{}}=@var{r@dots{}} |
ee2d5c50 | 34105 | @anchor{write register packet} |
b8ff78ce JB |
34106 | @cindex @samp{P} packet |
34107 | Write register @var{n@dots{}} with value @var{r@dots{}}. The register | |
599b237a | 34108 | number @var{n} is in hexadecimal, and @var{r@dots{}} contains two hex |
8e04817f | 34109 | digits for each byte in the register (target byte order). |
c906108c | 34110 | |
ee2d5c50 AC |
34111 | Reply: |
34112 | @table @samp | |
34113 | @item OK | |
34114 | for success | |
b8ff78ce | 34115 | @item E @var{NN} |
ee2d5c50 AC |
34116 | for an error |
34117 | @end table | |
34118 | ||
5f3bebba JB |
34119 | @item q @var{name} @var{params}@dots{} |
34120 | @itemx Q @var{name} @var{params}@dots{} | |
b8ff78ce | 34121 | @cindex @samp{q} packet |
b8ff78ce | 34122 | @cindex @samp{Q} packet |
5f3bebba JB |
34123 | General query (@samp{q}) and set (@samp{Q}). These packets are |
34124 | described fully in @ref{General Query Packets}. | |
c906108c | 34125 | |
b8ff78ce JB |
34126 | @item r |
34127 | @cindex @samp{r} packet | |
8e04817f | 34128 | Reset the entire system. |
c906108c | 34129 | |
b8ff78ce | 34130 | Don't use this packet; use the @samp{R} packet instead. |
ee2d5c50 | 34131 | |
b8ff78ce JB |
34132 | @item R @var{XX} |
34133 | @cindex @samp{R} packet | |
697aa1b7 | 34134 | Restart the program being debugged. The @var{XX}, while needed, is ignored. |
2d717e4f | 34135 | This packet is only available in extended mode (@pxref{extended mode}). |
ee2d5c50 | 34136 | |
8e04817f | 34137 | The @samp{R} packet has no reply. |
ee2d5c50 | 34138 | |
4f553f88 | 34139 | @item s @r{[}@var{addr}@r{]} |
b8ff78ce | 34140 | @cindex @samp{s} packet |
697aa1b7 | 34141 | Single step, resuming at @var{addr}. If |
b8ff78ce | 34142 | @var{addr} is omitted, resume at same address. |
c906108c | 34143 | |
393eab54 PA |
34144 | This packet is deprecated for multi-threading support. @xref{vCont |
34145 | packet}. | |
34146 | ||
ee2d5c50 AC |
34147 | Reply: |
34148 | @xref{Stop Reply Packets}, for the reply specifications. | |
34149 | ||
4f553f88 | 34150 | @item S @var{sig}@r{[};@var{addr}@r{]} |
ee2d5c50 | 34151 | @anchor{step with signal packet} |
b8ff78ce JB |
34152 | @cindex @samp{S} packet |
34153 | Step with signal. This is analogous to the @samp{C} packet, but | |
34154 | requests a single-step, rather than a normal resumption of execution. | |
c906108c | 34155 | |
393eab54 PA |
34156 | This packet is deprecated for multi-threading support. @xref{vCont |
34157 | packet}. | |
34158 | ||
ee2d5c50 AC |
34159 | Reply: |
34160 | @xref{Stop Reply Packets}, for the reply specifications. | |
34161 | ||
b8ff78ce JB |
34162 | @item t @var{addr}:@var{PP},@var{MM} |
34163 | @cindex @samp{t} packet | |
8e04817f | 34164 | Search backwards starting at address @var{addr} for a match with pattern |
697aa1b7 EZ |
34165 | @var{PP} and mask @var{MM}, both of which are are 4 byte long. |
34166 | There must be at least 3 digits in @var{addr}. | |
c906108c | 34167 | |
b90a069a | 34168 | @item T @var{thread-id} |
b8ff78ce | 34169 | @cindex @samp{T} packet |
b90a069a | 34170 | Find out if the thread @var{thread-id} is alive. @xref{thread-id syntax}. |
c906108c | 34171 | |
ee2d5c50 AC |
34172 | Reply: |
34173 | @table @samp | |
34174 | @item OK | |
34175 | thread is still alive | |
b8ff78ce | 34176 | @item E @var{NN} |
ee2d5c50 AC |
34177 | thread is dead |
34178 | @end table | |
34179 | ||
b8ff78ce JB |
34180 | @item v |
34181 | Packets starting with @samp{v} are identified by a multi-letter name, | |
34182 | up to the first @samp{;} or @samp{?} (or the end of the packet). | |
86d30acc | 34183 | |
2d717e4f DJ |
34184 | @item vAttach;@var{pid} |
34185 | @cindex @samp{vAttach} packet | |
8b23ecc4 SL |
34186 | Attach to a new process with the specified process ID @var{pid}. |
34187 | The process ID is a | |
34188 | hexadecimal integer identifying the process. In all-stop mode, all | |
34189 | threads in the attached process are stopped; in non-stop mode, it may be | |
34190 | attached without being stopped if that is supported by the target. | |
34191 | ||
34192 | @c In non-stop mode, on a successful vAttach, the stub should set the | |
34193 | @c current thread to a thread of the newly-attached process. After | |
34194 | @c attaching, GDB queries for the attached process's thread ID with qC. | |
34195 | @c Also note that, from a user perspective, whether or not the | |
34196 | @c target is stopped on attach in non-stop mode depends on whether you | |
34197 | @c use the foreground or background version of the attach command, not | |
34198 | @c on what vAttach does; GDB does the right thing with respect to either | |
34199 | @c stopping or restarting threads. | |
2d717e4f DJ |
34200 | |
34201 | This packet is only available in extended mode (@pxref{extended mode}). | |
34202 | ||
34203 | Reply: | |
34204 | @table @samp | |
34205 | @item E @var{nn} | |
34206 | for an error | |
34207 | @item @r{Any stop packet} | |
8b23ecc4 SL |
34208 | for success in all-stop mode (@pxref{Stop Reply Packets}) |
34209 | @item OK | |
34210 | for success in non-stop mode (@pxref{Remote Non-Stop}) | |
2d717e4f DJ |
34211 | @end table |
34212 | ||
b90a069a | 34213 | @item vCont@r{[};@var{action}@r{[}:@var{thread-id}@r{]]}@dots{} |
b8ff78ce | 34214 | @cindex @samp{vCont} packet |
393eab54 | 34215 | @anchor{vCont packet} |
b8ff78ce | 34216 | Resume the inferior, specifying different actions for each thread. |
b90a069a | 34217 | If an action is specified with no @var{thread-id}, then it is applied to any |
86d30acc | 34218 | threads that don't have a specific action specified; if no default action is |
8b23ecc4 SL |
34219 | specified then other threads should remain stopped in all-stop mode and |
34220 | in their current state in non-stop mode. | |
34221 | Specifying multiple | |
86d30acc | 34222 | default actions is an error; specifying no actions is also an error. |
b90a069a SL |
34223 | Thread IDs are specified using the syntax described in @ref{thread-id syntax}. |
34224 | ||
34225 | Currently supported actions are: | |
86d30acc | 34226 | |
b8ff78ce | 34227 | @table @samp |
86d30acc DJ |
34228 | @item c |
34229 | Continue. | |
b8ff78ce | 34230 | @item C @var{sig} |
8b23ecc4 | 34231 | Continue with signal @var{sig}. The signal @var{sig} should be two hex digits. |
86d30acc DJ |
34232 | @item s |
34233 | Step. | |
b8ff78ce | 34234 | @item S @var{sig} |
8b23ecc4 SL |
34235 | Step with signal @var{sig}. The signal @var{sig} should be two hex digits. |
34236 | @item t | |
34237 | Stop. | |
c1e36e3e PA |
34238 | @item r @var{start},@var{end} |
34239 | Step once, and then keep stepping as long as the thread stops at | |
34240 | addresses between @var{start} (inclusive) and @var{end} (exclusive). | |
34241 | The remote stub reports a stop reply when either the thread goes out | |
34242 | of the range or is stopped due to an unrelated reason, such as hitting | |
34243 | a breakpoint. @xref{range stepping}. | |
34244 | ||
34245 | If the range is empty (@var{start} == @var{end}), then the action | |
34246 | becomes equivalent to the @samp{s} action. In other words, | |
34247 | single-step once, and report the stop (even if the stepped instruction | |
34248 | jumps to @var{start}). | |
34249 | ||
34250 | (A stop reply may be sent at any point even if the PC is still within | |
34251 | the stepping range; for example, it is valid to implement this packet | |
34252 | in a degenerate way as a single instruction step operation.) | |
34253 | ||
86d30acc DJ |
34254 | @end table |
34255 | ||
8b23ecc4 SL |
34256 | The optional argument @var{addr} normally associated with the |
34257 | @samp{c}, @samp{C}, @samp{s}, and @samp{S} packets is | |
b8ff78ce | 34258 | not supported in @samp{vCont}. |
86d30acc | 34259 | |
08a0efd0 PA |
34260 | The @samp{t} action is only relevant in non-stop mode |
34261 | (@pxref{Remote Non-Stop}) and may be ignored by the stub otherwise. | |
8b23ecc4 SL |
34262 | A stop reply should be generated for any affected thread not already stopped. |
34263 | When a thread is stopped by means of a @samp{t} action, | |
34264 | the corresponding stop reply should indicate that the thread has stopped with | |
34265 | signal @samp{0}, regardless of whether the target uses some other signal | |
34266 | as an implementation detail. | |
34267 | ||
4220b2f8 TS |
34268 | The stub must support @samp{vCont} if it reports support for |
34269 | multiprocess extensions (@pxref{multiprocess extensions}). Note that in | |
34270 | this case @samp{vCont} actions can be specified to apply to all threads | |
34271 | in a process by using the @samp{p@var{pid}.-1} form of the | |
34272 | @var{thread-id}. | |
34273 | ||
86d30acc DJ |
34274 | Reply: |
34275 | @xref{Stop Reply Packets}, for the reply specifications. | |
34276 | ||
b8ff78ce JB |
34277 | @item vCont? |
34278 | @cindex @samp{vCont?} packet | |
d3e8051b | 34279 | Request a list of actions supported by the @samp{vCont} packet. |
86d30acc DJ |
34280 | |
34281 | Reply: | |
34282 | @table @samp | |
b8ff78ce JB |
34283 | @item vCont@r{[};@var{action}@dots{}@r{]} |
34284 | The @samp{vCont} packet is supported. Each @var{action} is a supported | |
34285 | command in the @samp{vCont} packet. | |
d57350ea | 34286 | @item @w{} |
b8ff78ce | 34287 | The @samp{vCont} packet is not supported. |
86d30acc | 34288 | @end table |
ee2d5c50 | 34289 | |
a6b151f1 DJ |
34290 | @item vFile:@var{operation}:@var{parameter}@dots{} |
34291 | @cindex @samp{vFile} packet | |
34292 | Perform a file operation on the target system. For details, | |
34293 | see @ref{Host I/O Packets}. | |
34294 | ||
68437a39 DJ |
34295 | @item vFlashErase:@var{addr},@var{length} |
34296 | @cindex @samp{vFlashErase} packet | |
34297 | Direct the stub to erase @var{length} bytes of flash starting at | |
34298 | @var{addr}. The region may enclose any number of flash blocks, but | |
34299 | its start and end must fall on block boundaries, as indicated by the | |
79a6e687 BW |
34300 | flash block size appearing in the memory map (@pxref{Memory Map |
34301 | Format}). @value{GDBN} groups flash memory programming operations | |
68437a39 DJ |
34302 | together, and sends a @samp{vFlashDone} request after each group; the |
34303 | stub is allowed to delay erase operation until the @samp{vFlashDone} | |
34304 | packet is received. | |
34305 | ||
34306 | Reply: | |
34307 | @table @samp | |
34308 | @item OK | |
34309 | for success | |
34310 | @item E @var{NN} | |
34311 | for an error | |
34312 | @end table | |
34313 | ||
34314 | @item vFlashWrite:@var{addr}:@var{XX@dots{}} | |
34315 | @cindex @samp{vFlashWrite} packet | |
34316 | Direct the stub to write data to flash address @var{addr}. The data | |
34317 | is passed in binary form using the same encoding as for the @samp{X} | |
34318 | packet (@pxref{Binary Data}). The memory ranges specified by | |
34319 | @samp{vFlashWrite} packets preceding a @samp{vFlashDone} packet must | |
34320 | not overlap, and must appear in order of increasing addresses | |
34321 | (although @samp{vFlashErase} packets for higher addresses may already | |
34322 | have been received; the ordering is guaranteed only between | |
34323 | @samp{vFlashWrite} packets). If a packet writes to an address that was | |
34324 | neither erased by a preceding @samp{vFlashErase} packet nor by some other | |
34325 | target-specific method, the results are unpredictable. | |
34326 | ||
34327 | ||
34328 | Reply: | |
34329 | @table @samp | |
34330 | @item OK | |
34331 | for success | |
34332 | @item E.memtype | |
34333 | for vFlashWrite addressing non-flash memory | |
34334 | @item E @var{NN} | |
34335 | for an error | |
34336 | @end table | |
34337 | ||
34338 | @item vFlashDone | |
34339 | @cindex @samp{vFlashDone} packet | |
34340 | Indicate to the stub that flash programming operation is finished. | |
34341 | The stub is permitted to delay or batch the effects of a group of | |
34342 | @samp{vFlashErase} and @samp{vFlashWrite} packets until a | |
34343 | @samp{vFlashDone} packet is received. The contents of the affected | |
34344 | regions of flash memory are unpredictable until the @samp{vFlashDone} | |
34345 | request is completed. | |
34346 | ||
b90a069a SL |
34347 | @item vKill;@var{pid} |
34348 | @cindex @samp{vKill} packet | |
36cb1214 | 34349 | @anchor{vKill packet} |
697aa1b7 | 34350 | Kill the process with the specified process ID @var{pid}, which is a |
b90a069a SL |
34351 | hexadecimal integer identifying the process. This packet is used in |
34352 | preference to @samp{k} when multiprocess protocol extensions are | |
34353 | supported; see @ref{multiprocess extensions}. | |
34354 | ||
34355 | Reply: | |
34356 | @table @samp | |
34357 | @item E @var{nn} | |
34358 | for an error | |
34359 | @item OK | |
34360 | for success | |
34361 | @end table | |
34362 | ||
2d717e4f DJ |
34363 | @item vRun;@var{filename}@r{[};@var{argument}@r{]}@dots{} |
34364 | @cindex @samp{vRun} packet | |
34365 | Run the program @var{filename}, passing it each @var{argument} on its | |
34366 | command line. The file and arguments are hex-encoded strings. If | |
34367 | @var{filename} is an empty string, the stub may use a default program | |
34368 | (e.g.@: the last program run). The program is created in the stopped | |
9b562ab8 | 34369 | state. |
2d717e4f | 34370 | |
8b23ecc4 SL |
34371 | @c FIXME: What about non-stop mode? |
34372 | ||
2d717e4f DJ |
34373 | This packet is only available in extended mode (@pxref{extended mode}). |
34374 | ||
34375 | Reply: | |
34376 | @table @samp | |
34377 | @item E @var{nn} | |
34378 | for an error | |
34379 | @item @r{Any stop packet} | |
34380 | for success (@pxref{Stop Reply Packets}) | |
34381 | @end table | |
34382 | ||
8b23ecc4 | 34383 | @item vStopped |
8b23ecc4 | 34384 | @cindex @samp{vStopped} packet |
8dbe8ece | 34385 | @xref{Notification Packets}. |
8b23ecc4 | 34386 | |
b8ff78ce | 34387 | @item X @var{addr},@var{length}:@var{XX@dots{}} |
9a6253be | 34388 | @anchor{X packet} |
b8ff78ce JB |
34389 | @cindex @samp{X} packet |
34390 | Write data to memory, where the data is transmitted in binary. | |
697aa1b7 | 34391 | Memory is specified by its address @var{addr} and number of bytes @var{length}; |
0876f84a | 34392 | @samp{@var{XX}@dots{}} is binary data (@pxref{Binary Data}). |
c906108c | 34393 | |
ee2d5c50 AC |
34394 | Reply: |
34395 | @table @samp | |
34396 | @item OK | |
34397 | for success | |
b8ff78ce | 34398 | @item E @var{NN} |
ee2d5c50 AC |
34399 | for an error |
34400 | @end table | |
34401 | ||
a1dcb23a DJ |
34402 | @item z @var{type},@var{addr},@var{kind} |
34403 | @itemx Z @var{type},@var{addr},@var{kind} | |
2f870471 | 34404 | @anchor{insert breakpoint or watchpoint packet} |
b8ff78ce JB |
34405 | @cindex @samp{z} packet |
34406 | @cindex @samp{Z} packets | |
34407 | Insert (@samp{Z}) or remove (@samp{z}) a @var{type} breakpoint or | |
a1dcb23a | 34408 | watchpoint starting at address @var{address} of kind @var{kind}. |
ee2d5c50 | 34409 | |
2f870471 AC |
34410 | Each breakpoint and watchpoint packet @var{type} is documented |
34411 | separately. | |
34412 | ||
512217c7 AC |
34413 | @emph{Implementation notes: A remote target shall return an empty string |
34414 | for an unrecognized breakpoint or watchpoint packet @var{type}. A | |
34415 | remote target shall support either both or neither of a given | |
b8ff78ce | 34416 | @samp{Z@var{type}@dots{}} and @samp{z@var{type}@dots{}} packet pair. To |
2f870471 AC |
34417 | avoid potential problems with duplicate packets, the operations should |
34418 | be implemented in an idempotent way.} | |
34419 | ||
a1dcb23a | 34420 | @item z0,@var{addr},@var{kind} |
d3ce09f5 | 34421 | @itemx Z0,@var{addr},@var{kind}@r{[};@var{cond_list}@dots{}@r{]}@r{[};cmds:@var{persist},@var{cmd_list}@dots{}@r{]} |
b8ff78ce JB |
34422 | @cindex @samp{z0} packet |
34423 | @cindex @samp{Z0} packet | |
34424 | Insert (@samp{Z0}) or remove (@samp{z0}) a memory breakpoint at address | |
a1dcb23a | 34425 | @var{addr} of type @var{kind}. |
2f870471 AC |
34426 | |
34427 | A memory breakpoint is implemented by replacing the instruction at | |
34428 | @var{addr} with a software breakpoint or trap instruction. The | |
a1dcb23a DJ |
34429 | @var{kind} is target-specific and typically indicates the size of |
34430 | the breakpoint in bytes that should be inserted. E.g., the @sc{arm} | |
34431 | and @sc{mips} can insert either a 2 or 4 byte breakpoint. Some | |
34432 | architectures have additional meanings for @var{kind}; | |
83364271 LM |
34433 | @var{cond_list} is an optional list of conditional expressions in bytecode |
34434 | form that should be evaluated on the target's side. These are the | |
34435 | conditions that should be taken into consideration when deciding if | |
34436 | the breakpoint trigger should be reported back to @var{GDBN}. | |
34437 | ||
34438 | The @var{cond_list} parameter is comprised of a series of expressions, | |
34439 | concatenated without separators. Each expression has the following form: | |
34440 | ||
34441 | @table @samp | |
34442 | ||
34443 | @item X @var{len},@var{expr} | |
34444 | @var{len} is the length of the bytecode expression and @var{expr} is the | |
34445 | actual conditional expression in bytecode form. | |
34446 | ||
34447 | @end table | |
34448 | ||
d3ce09f5 SS |
34449 | The optional @var{cmd_list} parameter introduces commands that may be |
34450 | run on the target, rather than being reported back to @value{GDBN}. | |
34451 | The parameter starts with a numeric flag @var{persist}; if the flag is | |
34452 | nonzero, then the breakpoint may remain active and the commands | |
34453 | continue to be run even when @value{GDBN} disconnects from the target. | |
34454 | Following this flag is a series of expressions concatenated with no | |
34455 | separators. Each expression has the following form: | |
34456 | ||
34457 | @table @samp | |
34458 | ||
34459 | @item X @var{len},@var{expr} | |
34460 | @var{len} is the length of the bytecode expression and @var{expr} is the | |
34461 | actual conditional expression in bytecode form. | |
34462 | ||
34463 | @end table | |
34464 | ||
a1dcb23a | 34465 | see @ref{Architecture-Specific Protocol Details}. |
c906108c | 34466 | |
2f870471 AC |
34467 | @emph{Implementation note: It is possible for a target to copy or move |
34468 | code that contains memory breakpoints (e.g., when implementing | |
34469 | overlays). The behavior of this packet, in the presence of such a | |
34470 | target, is not defined.} | |
c906108c | 34471 | |
ee2d5c50 AC |
34472 | Reply: |
34473 | @table @samp | |
2f870471 AC |
34474 | @item OK |
34475 | success | |
d57350ea | 34476 | @item @w{} |
2f870471 | 34477 | not supported |
b8ff78ce | 34478 | @item E @var{NN} |
ee2d5c50 | 34479 | for an error |
2f870471 AC |
34480 | @end table |
34481 | ||
a1dcb23a | 34482 | @item z1,@var{addr},@var{kind} |
83364271 | 34483 | @itemx Z1,@var{addr},@var{kind}@r{[};@var{cond_list}@dots{}@r{]} |
b8ff78ce JB |
34484 | @cindex @samp{z1} packet |
34485 | @cindex @samp{Z1} packet | |
34486 | Insert (@samp{Z1}) or remove (@samp{z1}) a hardware breakpoint at | |
a1dcb23a | 34487 | address @var{addr}. |
2f870471 AC |
34488 | |
34489 | A hardware breakpoint is implemented using a mechanism that is not | |
697aa1b7 | 34490 | dependant on being able to modify the target's memory. The @var{kind} |
83364271 | 34491 | and @var{cond_list} have the same meaning as in @samp{Z0} packets. |
2f870471 AC |
34492 | |
34493 | @emph{Implementation note: A hardware breakpoint is not affected by code | |
34494 | movement.} | |
34495 | ||
34496 | Reply: | |
34497 | @table @samp | |
ee2d5c50 | 34498 | @item OK |
2f870471 | 34499 | success |
d57350ea | 34500 | @item @w{} |
2f870471 | 34501 | not supported |
b8ff78ce | 34502 | @item E @var{NN} |
2f870471 AC |
34503 | for an error |
34504 | @end table | |
34505 | ||
a1dcb23a DJ |
34506 | @item z2,@var{addr},@var{kind} |
34507 | @itemx Z2,@var{addr},@var{kind} | |
b8ff78ce JB |
34508 | @cindex @samp{z2} packet |
34509 | @cindex @samp{Z2} packet | |
a1dcb23a | 34510 | Insert (@samp{Z2}) or remove (@samp{z2}) a write watchpoint at @var{addr}. |
697aa1b7 | 34511 | The number of bytes to watch is specified by @var{kind}. |
2f870471 AC |
34512 | |
34513 | Reply: | |
34514 | @table @samp | |
34515 | @item OK | |
34516 | success | |
d57350ea | 34517 | @item @w{} |
2f870471 | 34518 | not supported |
b8ff78ce | 34519 | @item E @var{NN} |
2f870471 AC |
34520 | for an error |
34521 | @end table | |
34522 | ||
a1dcb23a DJ |
34523 | @item z3,@var{addr},@var{kind} |
34524 | @itemx Z3,@var{addr},@var{kind} | |
b8ff78ce JB |
34525 | @cindex @samp{z3} packet |
34526 | @cindex @samp{Z3} packet | |
a1dcb23a | 34527 | Insert (@samp{Z3}) or remove (@samp{z3}) a read watchpoint at @var{addr}. |
697aa1b7 | 34528 | The number of bytes to watch is specified by @var{kind}. |
2f870471 AC |
34529 | |
34530 | Reply: | |
34531 | @table @samp | |
34532 | @item OK | |
34533 | success | |
d57350ea | 34534 | @item @w{} |
2f870471 | 34535 | not supported |
b8ff78ce | 34536 | @item E @var{NN} |
2f870471 AC |
34537 | for an error |
34538 | @end table | |
34539 | ||
a1dcb23a DJ |
34540 | @item z4,@var{addr},@var{kind} |
34541 | @itemx Z4,@var{addr},@var{kind} | |
b8ff78ce JB |
34542 | @cindex @samp{z4} packet |
34543 | @cindex @samp{Z4} packet | |
a1dcb23a | 34544 | Insert (@samp{Z4}) or remove (@samp{z4}) an access watchpoint at @var{addr}. |
697aa1b7 | 34545 | The number of bytes to watch is specified by @var{kind}. |
2f870471 AC |
34546 | |
34547 | Reply: | |
34548 | @table @samp | |
34549 | @item OK | |
34550 | success | |
d57350ea | 34551 | @item @w{} |
2f870471 | 34552 | not supported |
b8ff78ce | 34553 | @item E @var{NN} |
2f870471 | 34554 | for an error |
ee2d5c50 AC |
34555 | @end table |
34556 | ||
34557 | @end table | |
c906108c | 34558 | |
ee2d5c50 AC |
34559 | @node Stop Reply Packets |
34560 | @section Stop Reply Packets | |
34561 | @cindex stop reply packets | |
c906108c | 34562 | |
8b23ecc4 SL |
34563 | The @samp{C}, @samp{c}, @samp{S}, @samp{s}, @samp{vCont}, |
34564 | @samp{vAttach}, @samp{vRun}, @samp{vStopped}, and @samp{?} packets can | |
34565 | receive any of the below as a reply. Except for @samp{?} | |
34566 | and @samp{vStopped}, that reply is only returned | |
b8ff78ce | 34567 | when the target halts. In the below the exact meaning of @dfn{signal |
89be2091 DJ |
34568 | number} is defined by the header @file{include/gdb/signals.h} in the |
34569 | @value{GDBN} source code. | |
c906108c | 34570 | |
b8ff78ce JB |
34571 | As in the description of request packets, we include spaces in the |
34572 | reply templates for clarity; these are not part of the reply packet's | |
34573 | syntax. No @value{GDBN} stop reply packet uses spaces to separate its | |
34574 | components. | |
c906108c | 34575 | |
b8ff78ce | 34576 | @table @samp |
ee2d5c50 | 34577 | |
b8ff78ce | 34578 | @item S @var{AA} |
599b237a | 34579 | The program received signal number @var{AA} (a two-digit hexadecimal |
940178d3 JB |
34580 | number). This is equivalent to a @samp{T} response with no |
34581 | @var{n}:@var{r} pairs. | |
c906108c | 34582 | |
b8ff78ce JB |
34583 | @item T @var{AA} @var{n1}:@var{r1};@var{n2}:@var{r2};@dots{} |
34584 | @cindex @samp{T} packet reply | |
599b237a | 34585 | The program received signal number @var{AA} (a two-digit hexadecimal |
940178d3 JB |
34586 | number). This is equivalent to an @samp{S} response, except that the |
34587 | @samp{@var{n}:@var{r}} pairs can carry values of important registers | |
34588 | and other information directly in the stop reply packet, reducing | |
34589 | round-trip latency. Single-step and breakpoint traps are reported | |
34590 | this way. Each @samp{@var{n}:@var{r}} pair is interpreted as follows: | |
cfa9d6d9 DJ |
34591 | |
34592 | @itemize @bullet | |
b8ff78ce | 34593 | @item |
599b237a | 34594 | If @var{n} is a hexadecimal number, it is a register number, and the |
697aa1b7 | 34595 | corresponding @var{r} gives that register's value. The data @var{r} is a |
b8ff78ce JB |
34596 | series of bytes in target byte order, with each byte given by a |
34597 | two-digit hex number. | |
cfa9d6d9 | 34598 | |
b8ff78ce | 34599 | @item |
b90a069a SL |
34600 | If @var{n} is @samp{thread}, then @var{r} is the @var{thread-id} of |
34601 | the stopped thread, as specified in @ref{thread-id syntax}. | |
cfa9d6d9 | 34602 | |
dc146f7c VP |
34603 | @item |
34604 | If @var{n} is @samp{core}, then @var{r} is the hexadecimal number of | |
34605 | the core on which the stop event was detected. | |
34606 | ||
b8ff78ce | 34607 | @item |
cfa9d6d9 DJ |
34608 | If @var{n} is a recognized @dfn{stop reason}, it describes a more |
34609 | specific event that stopped the target. The currently defined stop | |
697aa1b7 | 34610 | reasons are listed below. The @var{aa} should be @samp{05}, the trap |
cfa9d6d9 DJ |
34611 | signal. At most one stop reason should be present. |
34612 | ||
b8ff78ce JB |
34613 | @item |
34614 | Otherwise, @value{GDBN} should ignore this @samp{@var{n}:@var{r}} pair | |
34615 | and go on to the next; this allows us to extend the protocol in the | |
34616 | future. | |
cfa9d6d9 DJ |
34617 | @end itemize |
34618 | ||
34619 | The currently defined stop reasons are: | |
34620 | ||
34621 | @table @samp | |
34622 | @item watch | |
34623 | @itemx rwatch | |
34624 | @itemx awatch | |
34625 | The packet indicates a watchpoint hit, and @var{r} is the data address, in | |
34626 | hex. | |
34627 | ||
34628 | @cindex shared library events, remote reply | |
34629 | @item library | |
34630 | The packet indicates that the loaded libraries have changed. | |
34631 | @value{GDBN} should use @samp{qXfer:libraries:read} to fetch a new | |
697aa1b7 | 34632 | list of loaded libraries. The @var{r} part is ignored. |
bacec72f MS |
34633 | |
34634 | @cindex replay log events, remote reply | |
34635 | @item replaylog | |
34636 | The packet indicates that the target cannot continue replaying | |
34637 | logged execution events, because it has reached the end (or the | |
34638 | beginning when executing backward) of the log. The value of @var{r} | |
34639 | will be either @samp{begin} or @samp{end}. @xref{Reverse Execution}, | |
34640 | for more information. | |
cfa9d6d9 | 34641 | @end table |
ee2d5c50 | 34642 | |
b8ff78ce | 34643 | @item W @var{AA} |
b90a069a | 34644 | @itemx W @var{AA} ; process:@var{pid} |
8e04817f | 34645 | The process exited, and @var{AA} is the exit status. This is only |
ee2d5c50 AC |
34646 | applicable to certain targets. |
34647 | ||
b90a069a SL |
34648 | The second form of the response, including the process ID of the exited |
34649 | process, can be used only when @value{GDBN} has reported support for | |
34650 | multiprocess protocol extensions; see @ref{multiprocess extensions}. | |
34651 | The @var{pid} is formatted as a big-endian hex string. | |
34652 | ||
b8ff78ce | 34653 | @item X @var{AA} |
b90a069a | 34654 | @itemx X @var{AA} ; process:@var{pid} |
8e04817f | 34655 | The process terminated with signal @var{AA}. |
c906108c | 34656 | |
b90a069a SL |
34657 | The second form of the response, including the process ID of the |
34658 | terminated process, can be used only when @value{GDBN} has reported | |
34659 | support for multiprocess protocol extensions; see @ref{multiprocess | |
34660 | extensions}. The @var{pid} is formatted as a big-endian hex string. | |
34661 | ||
b8ff78ce JB |
34662 | @item O @var{XX}@dots{} |
34663 | @samp{@var{XX}@dots{}} is hex encoding of @sc{ascii} data, to be | |
34664 | written as the program's console output. This can happen at any time | |
34665 | while the program is running and the debugger should continue to wait | |
8b23ecc4 | 34666 | for @samp{W}, @samp{T}, etc. This reply is not permitted in non-stop mode. |
0ce1b118 | 34667 | |
b8ff78ce | 34668 | @item F @var{call-id},@var{parameter}@dots{} |
0ce1b118 CV |
34669 | @var{call-id} is the identifier which says which host system call should |
34670 | be called. This is just the name of the function. Translation into the | |
34671 | correct system call is only applicable as it's defined in @value{GDBN}. | |
79a6e687 | 34672 | @xref{File-I/O Remote Protocol Extension}, for a list of implemented |
0ce1b118 CV |
34673 | system calls. |
34674 | ||
b8ff78ce JB |
34675 | @samp{@var{parameter}@dots{}} is a list of parameters as defined for |
34676 | this very system call. | |
0ce1b118 | 34677 | |
b8ff78ce JB |
34678 | The target replies with this packet when it expects @value{GDBN} to |
34679 | call a host system call on behalf of the target. @value{GDBN} replies | |
34680 | with an appropriate @samp{F} packet and keeps up waiting for the next | |
34681 | reply packet from the target. The latest @samp{C}, @samp{c}, @samp{S} | |
79a6e687 BW |
34682 | or @samp{s} action is expected to be continued. @xref{File-I/O Remote |
34683 | Protocol Extension}, for more details. | |
0ce1b118 | 34684 | |
ee2d5c50 AC |
34685 | @end table |
34686 | ||
34687 | @node General Query Packets | |
34688 | @section General Query Packets | |
9c16f35a | 34689 | @cindex remote query requests |
c906108c | 34690 | |
5f3bebba JB |
34691 | Packets starting with @samp{q} are @dfn{general query packets}; |
34692 | packets starting with @samp{Q} are @dfn{general set packets}. General | |
34693 | query and set packets are a semi-unified form for retrieving and | |
34694 | sending information to and from the stub. | |
34695 | ||
34696 | The initial letter of a query or set packet is followed by a name | |
34697 | indicating what sort of thing the packet applies to. For example, | |
34698 | @value{GDBN} may use a @samp{qSymbol} packet to exchange symbol | |
34699 | definitions with the stub. These packet names follow some | |
34700 | conventions: | |
34701 | ||
34702 | @itemize @bullet | |
34703 | @item | |
34704 | The name must not contain commas, colons or semicolons. | |
34705 | @item | |
34706 | Most @value{GDBN} query and set packets have a leading upper case | |
34707 | letter. | |
34708 | @item | |
34709 | The names of custom vendor packets should use a company prefix, in | |
34710 | lower case, followed by a period. For example, packets designed at | |
34711 | the Acme Corporation might begin with @samp{qacme.foo} (for querying | |
34712 | foos) or @samp{Qacme.bar} (for setting bars). | |
34713 | @end itemize | |
34714 | ||
aa56d27a JB |
34715 | The name of a query or set packet should be separated from any |
34716 | parameters by a @samp{:}; the parameters themselves should be | |
34717 | separated by @samp{,} or @samp{;}. Stubs must be careful to match the | |
369af7bd DJ |
34718 | full packet name, and check for a separator or the end of the packet, |
34719 | in case two packet names share a common prefix. New packets should not begin | |
34720 | with @samp{qC}, @samp{qP}, or @samp{qL}@footnote{The @samp{qP} and @samp{qL} | |
34721 | packets predate these conventions, and have arguments without any terminator | |
34722 | for the packet name; we suspect they are in widespread use in places that | |
34723 | are difficult to upgrade. The @samp{qC} packet has no arguments, but some | |
34724 | existing stubs (e.g.@: RedBoot) are known to not check for the end of the | |
34725 | packet.}. | |
c906108c | 34726 | |
b8ff78ce JB |
34727 | Like the descriptions of the other packets, each description here |
34728 | has a template showing the packet's overall syntax, followed by an | |
34729 | explanation of the packet's meaning. We include spaces in some of the | |
34730 | templates for clarity; these are not part of the packet's syntax. No | |
34731 | @value{GDBN} packet uses spaces to separate its components. | |
34732 | ||
5f3bebba JB |
34733 | Here are the currently defined query and set packets: |
34734 | ||
b8ff78ce | 34735 | @table @samp |
c906108c | 34736 | |
d1feda86 | 34737 | @item QAgent:1 |
af4238e5 | 34738 | @itemx QAgent:0 |
d1feda86 YQ |
34739 | Turn on or off the agent as a helper to perform some debugging operations |
34740 | delegated from @value{GDBN} (@pxref{Control Agent}). | |
34741 | ||
d914c394 SS |
34742 | @item QAllow:@var{op}:@var{val}@dots{} |
34743 | @cindex @samp{QAllow} packet | |
34744 | Specify which operations @value{GDBN} expects to request of the | |
34745 | target, as a semicolon-separated list of operation name and value | |
34746 | pairs. Possible values for @var{op} include @samp{WriteReg}, | |
34747 | @samp{WriteMem}, @samp{InsertBreak}, @samp{InsertTrace}, | |
34748 | @samp{InsertFastTrace}, and @samp{Stop}. @var{val} is either 0, | |
34749 | indicating that @value{GDBN} will not request the operation, or 1, | |
34750 | indicating that it may. (The target can then use this to set up its | |
34751 | own internals optimally, for instance if the debugger never expects to | |
34752 | insert breakpoints, it may not need to install its own trap handler.) | |
34753 | ||
b8ff78ce | 34754 | @item qC |
9c16f35a | 34755 | @cindex current thread, remote request |
b8ff78ce | 34756 | @cindex @samp{qC} packet |
b90a069a | 34757 | Return the current thread ID. |
ee2d5c50 AC |
34758 | |
34759 | Reply: | |
34760 | @table @samp | |
b90a069a SL |
34761 | @item QC @var{thread-id} |
34762 | Where @var{thread-id} is a thread ID as documented in | |
34763 | @ref{thread-id syntax}. | |
b8ff78ce | 34764 | @item @r{(anything else)} |
b90a069a | 34765 | Any other reply implies the old thread ID. |
ee2d5c50 AC |
34766 | @end table |
34767 | ||
b8ff78ce | 34768 | @item qCRC:@var{addr},@var{length} |
ff2587ec | 34769 | @cindex CRC of memory block, remote request |
b8ff78ce | 34770 | @cindex @samp{qCRC} packet |
936d2992 | 34771 | @anchor{qCRC packet} |
99e008fe EZ |
34772 | Compute the CRC checksum of a block of memory using CRC-32 defined in |
34773 | IEEE 802.3. The CRC is computed byte at a time, taking the most | |
34774 | significant bit of each byte first. The initial pattern code | |
34775 | @code{0xffffffff} is used to ensure leading zeros affect the CRC. | |
34776 | ||
34777 | @emph{Note:} This is the same CRC used in validating separate debug | |
34778 | files (@pxref{Separate Debug Files, , Debugging Information in Separate | |
34779 | Files}). However the algorithm is slightly different. When validating | |
34780 | separate debug files, the CRC is computed taking the @emph{least} | |
34781 | significant bit of each byte first, and the final result is inverted to | |
34782 | detect trailing zeros. | |
34783 | ||
ff2587ec WZ |
34784 | Reply: |
34785 | @table @samp | |
b8ff78ce | 34786 | @item E @var{NN} |
ff2587ec | 34787 | An error (such as memory fault) |
b8ff78ce JB |
34788 | @item C @var{crc32} |
34789 | The specified memory region's checksum is @var{crc32}. | |
ff2587ec WZ |
34790 | @end table |
34791 | ||
03583c20 UW |
34792 | @item QDisableRandomization:@var{value} |
34793 | @cindex disable address space randomization, remote request | |
34794 | @cindex @samp{QDisableRandomization} packet | |
34795 | Some target operating systems will randomize the virtual address space | |
34796 | of the inferior process as a security feature, but provide a feature | |
34797 | to disable such randomization, e.g.@: to allow for a more deterministic | |
34798 | debugging experience. On such systems, this packet with a @var{value} | |
34799 | of 1 directs the target to disable address space randomization for | |
34800 | processes subsequently started via @samp{vRun} packets, while a packet | |
34801 | with a @var{value} of 0 tells the target to enable address space | |
34802 | randomization. | |
34803 | ||
34804 | This packet is only available in extended mode (@pxref{extended mode}). | |
34805 | ||
34806 | Reply: | |
34807 | @table @samp | |
34808 | @item OK | |
34809 | The request succeeded. | |
34810 | ||
34811 | @item E @var{nn} | |
697aa1b7 | 34812 | An error occurred. The error number @var{nn} is given as hex digits. |
03583c20 | 34813 | |
d57350ea | 34814 | @item @w{} |
03583c20 UW |
34815 | An empty reply indicates that @samp{QDisableRandomization} is not supported |
34816 | by the stub. | |
34817 | @end table | |
34818 | ||
34819 | This packet is not probed by default; the remote stub must request it, | |
34820 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
34821 | This should only be done on targets that actually support disabling | |
34822 | address space randomization. | |
34823 | ||
b8ff78ce JB |
34824 | @item qfThreadInfo |
34825 | @itemx qsThreadInfo | |
9c16f35a | 34826 | @cindex list active threads, remote request |
b8ff78ce JB |
34827 | @cindex @samp{qfThreadInfo} packet |
34828 | @cindex @samp{qsThreadInfo} packet | |
b90a069a | 34829 | Obtain a list of all active thread IDs from the target (OS). Since there |
8e04817f AC |
34830 | may be too many active threads to fit into one reply packet, this query |
34831 | works iteratively: it may require more than one query/reply sequence to | |
34832 | obtain the entire list of threads. The first query of the sequence will | |
b8ff78ce JB |
34833 | be the @samp{qfThreadInfo} query; subsequent queries in the |
34834 | sequence will be the @samp{qsThreadInfo} query. | |
ee2d5c50 | 34835 | |
b8ff78ce | 34836 | NOTE: This packet replaces the @samp{qL} query (see below). |
ee2d5c50 AC |
34837 | |
34838 | Reply: | |
34839 | @table @samp | |
b90a069a SL |
34840 | @item m @var{thread-id} |
34841 | A single thread ID | |
34842 | @item m @var{thread-id},@var{thread-id}@dots{} | |
34843 | a comma-separated list of thread IDs | |
b8ff78ce JB |
34844 | @item l |
34845 | (lower case letter @samp{L}) denotes end of list. | |
ee2d5c50 AC |
34846 | @end table |
34847 | ||
34848 | In response to each query, the target will reply with a list of one or | |
b90a069a | 34849 | more thread IDs, separated by commas. |
e1aac25b | 34850 | @value{GDBN} will respond to each reply with a request for more thread |
b8ff78ce | 34851 | ids (using the @samp{qs} form of the query), until the target responds |
501994c0 | 34852 | with @samp{l} (lower-case ell, for @dfn{last}). |
b90a069a SL |
34853 | Refer to @ref{thread-id syntax}, for the format of the @var{thread-id} |
34854 | fields. | |
c906108c | 34855 | |
8dfcab11 DT |
34856 | @emph{Note: @value{GDBN} will send the @code{qfThreadInfo} query during the |
34857 | initial connection with the remote target, and the very first thread ID | |
34858 | mentioned in the reply will be stopped by @value{GDBN} in a subsequent | |
34859 | message. Therefore, the stub should ensure that the first thread ID in | |
34860 | the @code{qfThreadInfo} reply is suitable for being stopped by @value{GDBN}.} | |
34861 | ||
b8ff78ce | 34862 | @item qGetTLSAddr:@var{thread-id},@var{offset},@var{lm} |
ff2587ec | 34863 | @cindex get thread-local storage address, remote request |
b8ff78ce | 34864 | @cindex @samp{qGetTLSAddr} packet |
ff2587ec WZ |
34865 | Fetch the address associated with thread local storage specified |
34866 | by @var{thread-id}, @var{offset}, and @var{lm}. | |
34867 | ||
b90a069a SL |
34868 | @var{thread-id} is the thread ID associated with the |
34869 | thread for which to fetch the TLS address. @xref{thread-id syntax}. | |
ff2587ec WZ |
34870 | |
34871 | @var{offset} is the (big endian, hex encoded) offset associated with the | |
34872 | thread local variable. (This offset is obtained from the debug | |
34873 | information associated with the variable.) | |
34874 | ||
db2e3e2e | 34875 | @var{lm} is the (big endian, hex encoded) OS/ABI-specific encoding of the |
7a9dd1b2 | 34876 | load module associated with the thread local storage. For example, |
ff2587ec WZ |
34877 | a @sc{gnu}/Linux system will pass the link map address of the shared |
34878 | object associated with the thread local storage under consideration. | |
34879 | Other operating environments may choose to represent the load module | |
34880 | differently, so the precise meaning of this parameter will vary. | |
ee2d5c50 AC |
34881 | |
34882 | Reply: | |
b8ff78ce JB |
34883 | @table @samp |
34884 | @item @var{XX}@dots{} | |
ff2587ec WZ |
34885 | Hex encoded (big endian) bytes representing the address of the thread |
34886 | local storage requested. | |
34887 | ||
b8ff78ce | 34888 | @item E @var{nn} |
697aa1b7 | 34889 | An error occurred. The error number @var{nn} is given as hex digits. |
ff2587ec | 34890 | |
d57350ea | 34891 | @item @w{} |
b8ff78ce | 34892 | An empty reply indicates that @samp{qGetTLSAddr} is not supported by the stub. |
ee2d5c50 AC |
34893 | @end table |
34894 | ||
711e434b PM |
34895 | @item qGetTIBAddr:@var{thread-id} |
34896 | @cindex get thread information block address | |
34897 | @cindex @samp{qGetTIBAddr} packet | |
34898 | Fetch address of the Windows OS specific Thread Information Block. | |
34899 | ||
34900 | @var{thread-id} is the thread ID associated with the thread. | |
34901 | ||
34902 | Reply: | |
34903 | @table @samp | |
34904 | @item @var{XX}@dots{} | |
34905 | Hex encoded (big endian) bytes representing the linear address of the | |
34906 | thread information block. | |
34907 | ||
34908 | @item E @var{nn} | |
34909 | An error occured. This means that either the thread was not found, or the | |
34910 | address could not be retrieved. | |
34911 | ||
d57350ea | 34912 | @item @w{} |
711e434b PM |
34913 | An empty reply indicates that @samp{qGetTIBAddr} is not supported by the stub. |
34914 | @end table | |
34915 | ||
b8ff78ce | 34916 | @item qL @var{startflag} @var{threadcount} @var{nextthread} |
8e04817f AC |
34917 | Obtain thread information from RTOS. Where: @var{startflag} (one hex |
34918 | digit) is one to indicate the first query and zero to indicate a | |
34919 | subsequent query; @var{threadcount} (two hex digits) is the maximum | |
34920 | number of threads the response packet can contain; and @var{nextthread} | |
34921 | (eight hex digits), for subsequent queries (@var{startflag} is zero), is | |
34922 | returned in the response as @var{argthread}. | |
ee2d5c50 | 34923 | |
b8ff78ce | 34924 | Don't use this packet; use the @samp{qfThreadInfo} query instead (see above). |
ee2d5c50 AC |
34925 | |
34926 | Reply: | |
34927 | @table @samp | |
b8ff78ce | 34928 | @item qM @var{count} @var{done} @var{argthread} @var{thread}@dots{} |
8e04817f AC |
34929 | Where: @var{count} (two hex digits) is the number of threads being |
34930 | returned; @var{done} (one hex digit) is zero to indicate more threads | |
34931 | and one indicates no further threads; @var{argthreadid} (eight hex | |
b8ff78ce | 34932 | digits) is @var{nextthread} from the request packet; @var{thread}@dots{} |
697aa1b7 EZ |
34933 | is a sequence of thread IDs, @var{threadid} (eight hex |
34934 | digits), from the target. See @code{remote.c:parse_threadlist_response()}. | |
ee2d5c50 | 34935 | @end table |
c906108c | 34936 | |
b8ff78ce | 34937 | @item qOffsets |
9c16f35a | 34938 | @cindex section offsets, remote request |
b8ff78ce | 34939 | @cindex @samp{qOffsets} packet |
31d99776 DJ |
34940 | Get section offsets that the target used when relocating the downloaded |
34941 | image. | |
c906108c | 34942 | |
ee2d5c50 AC |
34943 | Reply: |
34944 | @table @samp | |
31d99776 DJ |
34945 | @item Text=@var{xxx};Data=@var{yyy}@r{[};Bss=@var{zzz}@r{]} |
34946 | Relocate the @code{Text} section by @var{xxx} from its original address. | |
34947 | Relocate the @code{Data} section by @var{yyy} from its original address. | |
34948 | If the object file format provides segment information (e.g.@: @sc{elf} | |
34949 | @samp{PT_LOAD} program headers), @value{GDBN} will relocate entire | |
34950 | segments by the supplied offsets. | |
34951 | ||
34952 | @emph{Note: while a @code{Bss} offset may be included in the response, | |
34953 | @value{GDBN} ignores this and instead applies the @code{Data} offset | |
34954 | to the @code{Bss} section.} | |
34955 | ||
34956 | @item TextSeg=@var{xxx}@r{[};DataSeg=@var{yyy}@r{]} | |
34957 | Relocate the first segment of the object file, which conventionally | |
34958 | contains program code, to a starting address of @var{xxx}. If | |
34959 | @samp{DataSeg} is specified, relocate the second segment, which | |
34960 | conventionally contains modifiable data, to a starting address of | |
34961 | @var{yyy}. @value{GDBN} will report an error if the object file | |
34962 | does not contain segment information, or does not contain at least | |
34963 | as many segments as mentioned in the reply. Extra segments are | |
34964 | kept at fixed offsets relative to the last relocated segment. | |
ee2d5c50 AC |
34965 | @end table |
34966 | ||
b90a069a | 34967 | @item qP @var{mode} @var{thread-id} |
9c16f35a | 34968 | @cindex thread information, remote request |
b8ff78ce | 34969 | @cindex @samp{qP} packet |
b90a069a SL |
34970 | Returns information on @var{thread-id}. Where: @var{mode} is a hex |
34971 | encoded 32 bit mode; @var{thread-id} is a thread ID | |
34972 | (@pxref{thread-id syntax}). | |
ee2d5c50 | 34973 | |
aa56d27a JB |
34974 | Don't use this packet; use the @samp{qThreadExtraInfo} query instead |
34975 | (see below). | |
34976 | ||
b8ff78ce | 34977 | Reply: see @code{remote.c:remote_unpack_thread_info_response()}. |
c906108c | 34978 | |
8b23ecc4 | 34979 | @item QNonStop:1 |
687e43a4 | 34980 | @itemx QNonStop:0 |
8b23ecc4 SL |
34981 | @cindex non-stop mode, remote request |
34982 | @cindex @samp{QNonStop} packet | |
34983 | @anchor{QNonStop} | |
34984 | Enter non-stop (@samp{QNonStop:1}) or all-stop (@samp{QNonStop:0}) mode. | |
34985 | @xref{Remote Non-Stop}, for more information. | |
34986 | ||
34987 | Reply: | |
34988 | @table @samp | |
34989 | @item OK | |
34990 | The request succeeded. | |
34991 | ||
34992 | @item E @var{nn} | |
697aa1b7 | 34993 | An error occurred. The error number @var{nn} is given as hex digits. |
8b23ecc4 | 34994 | |
d57350ea | 34995 | @item @w{} |
8b23ecc4 SL |
34996 | An empty reply indicates that @samp{QNonStop} is not supported by |
34997 | the stub. | |
34998 | @end table | |
34999 | ||
35000 | This packet is not probed by default; the remote stub must request it, | |
35001 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35002 | Use of this packet is controlled by the @code{set non-stop} command; | |
35003 | @pxref{Non-Stop Mode}. | |
35004 | ||
89be2091 DJ |
35005 | @item QPassSignals: @var{signal} @r{[};@var{signal}@r{]}@dots{} |
35006 | @cindex pass signals to inferior, remote request | |
35007 | @cindex @samp{QPassSignals} packet | |
23181151 | 35008 | @anchor{QPassSignals} |
89be2091 DJ |
35009 | Each listed @var{signal} should be passed directly to the inferior process. |
35010 | Signals are numbered identically to continue packets and stop replies | |
35011 | (@pxref{Stop Reply Packets}). Each @var{signal} list item should be | |
35012 | strictly greater than the previous item. These signals do not need to stop | |
35013 | the inferior, or be reported to @value{GDBN}. All other signals should be | |
35014 | reported to @value{GDBN}. Multiple @samp{QPassSignals} packets do not | |
35015 | combine; any earlier @samp{QPassSignals} list is completely replaced by the | |
35016 | new list. This packet improves performance when using @samp{handle | |
35017 | @var{signal} nostop noprint pass}. | |
35018 | ||
35019 | Reply: | |
35020 | @table @samp | |
35021 | @item OK | |
35022 | The request succeeded. | |
35023 | ||
35024 | @item E @var{nn} | |
697aa1b7 | 35025 | An error occurred. The error number @var{nn} is given as hex digits. |
89be2091 | 35026 | |
d57350ea | 35027 | @item @w{} |
89be2091 DJ |
35028 | An empty reply indicates that @samp{QPassSignals} is not supported by |
35029 | the stub. | |
35030 | @end table | |
35031 | ||
35032 | Use of this packet is controlled by the @code{set remote pass-signals} | |
79a6e687 | 35033 | command (@pxref{Remote Configuration, set remote pass-signals}). |
89be2091 DJ |
35034 | This packet is not probed by default; the remote stub must request it, |
35035 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35036 | ||
9b224c5e PA |
35037 | @item QProgramSignals: @var{signal} @r{[};@var{signal}@r{]}@dots{} |
35038 | @cindex signals the inferior may see, remote request | |
35039 | @cindex @samp{QProgramSignals} packet | |
35040 | @anchor{QProgramSignals} | |
35041 | Each listed @var{signal} may be delivered to the inferior process. | |
35042 | Others should be silently discarded. | |
35043 | ||
35044 | In some cases, the remote stub may need to decide whether to deliver a | |
35045 | signal to the program or not without @value{GDBN} involvement. One | |
35046 | example of that is while detaching --- the program's threads may have | |
35047 | stopped for signals that haven't yet had a chance of being reported to | |
35048 | @value{GDBN}, and so the remote stub can use the signal list specified | |
35049 | by this packet to know whether to deliver or ignore those pending | |
35050 | signals. | |
35051 | ||
35052 | This does not influence whether to deliver a signal as requested by a | |
35053 | resumption packet (@pxref{vCont packet}). | |
35054 | ||
35055 | Signals are numbered identically to continue packets and stop replies | |
35056 | (@pxref{Stop Reply Packets}). Each @var{signal} list item should be | |
35057 | strictly greater than the previous item. Multiple | |
35058 | @samp{QProgramSignals} packets do not combine; any earlier | |
35059 | @samp{QProgramSignals} list is completely replaced by the new list. | |
35060 | ||
35061 | Reply: | |
35062 | @table @samp | |
35063 | @item OK | |
35064 | The request succeeded. | |
35065 | ||
35066 | @item E @var{nn} | |
697aa1b7 | 35067 | An error occurred. The error number @var{nn} is given as hex digits. |
9b224c5e | 35068 | |
d57350ea | 35069 | @item @w{} |
9b224c5e PA |
35070 | An empty reply indicates that @samp{QProgramSignals} is not supported |
35071 | by the stub. | |
35072 | @end table | |
35073 | ||
35074 | Use of this packet is controlled by the @code{set remote program-signals} | |
35075 | command (@pxref{Remote Configuration, set remote program-signals}). | |
35076 | This packet is not probed by default; the remote stub must request it, | |
35077 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35078 | ||
b8ff78ce | 35079 | @item qRcmd,@var{command} |
ff2587ec | 35080 | @cindex execute remote command, remote request |
b8ff78ce | 35081 | @cindex @samp{qRcmd} packet |
ff2587ec | 35082 | @var{command} (hex encoded) is passed to the local interpreter for |
b8ff78ce JB |
35083 | execution. Invalid commands should be reported using the output |
35084 | string. Before the final result packet, the target may also respond | |
35085 | with a number of intermediate @samp{O@var{output}} console output | |
35086 | packets. @emph{Implementors should note that providing access to a | |
35087 | stubs's interpreter may have security implications}. | |
fa93a9d8 | 35088 | |
ff2587ec WZ |
35089 | Reply: |
35090 | @table @samp | |
35091 | @item OK | |
35092 | A command response with no output. | |
35093 | @item @var{OUTPUT} | |
35094 | A command response with the hex encoded output string @var{OUTPUT}. | |
b8ff78ce | 35095 | @item E @var{NN} |
ff2587ec | 35096 | Indicate a badly formed request. |
d57350ea | 35097 | @item @w{} |
b8ff78ce | 35098 | An empty reply indicates that @samp{qRcmd} is not recognized. |
ff2587ec | 35099 | @end table |
fa93a9d8 | 35100 | |
aa56d27a JB |
35101 | (Note that the @code{qRcmd} packet's name is separated from the |
35102 | command by a @samp{,}, not a @samp{:}, contrary to the naming | |
35103 | conventions above. Please don't use this packet as a model for new | |
35104 | packets.) | |
35105 | ||
08388c79 DE |
35106 | @item qSearch:memory:@var{address};@var{length};@var{search-pattern} |
35107 | @cindex searching memory, in remote debugging | |
5c4808ca | 35108 | @ifnotinfo |
08388c79 | 35109 | @cindex @samp{qSearch:memory} packet |
5c4808ca EZ |
35110 | @end ifnotinfo |
35111 | @cindex @samp{qSearch memory} packet | |
08388c79 DE |
35112 | @anchor{qSearch memory} |
35113 | Search @var{length} bytes at @var{address} for @var{search-pattern}. | |
697aa1b7 EZ |
35114 | Both @var{address} and @var{length} are encoded in hex; |
35115 | @var{search-pattern} is a sequence of bytes, also hex encoded. | |
08388c79 DE |
35116 | |
35117 | Reply: | |
35118 | @table @samp | |
35119 | @item 0 | |
35120 | The pattern was not found. | |
35121 | @item 1,address | |
35122 | The pattern was found at @var{address}. | |
35123 | @item E @var{NN} | |
35124 | A badly formed request or an error was encountered while searching memory. | |
d57350ea | 35125 | @item @w{} |
08388c79 DE |
35126 | An empty reply indicates that @samp{qSearch:memory} is not recognized. |
35127 | @end table | |
35128 | ||
a6f3e723 SL |
35129 | @item QStartNoAckMode |
35130 | @cindex @samp{QStartNoAckMode} packet | |
35131 | @anchor{QStartNoAckMode} | |
35132 | Request that the remote stub disable the normal @samp{+}/@samp{-} | |
35133 | protocol acknowledgments (@pxref{Packet Acknowledgment}). | |
35134 | ||
35135 | Reply: | |
35136 | @table @samp | |
35137 | @item OK | |
35138 | The stub has switched to no-acknowledgment mode. | |
35139 | @value{GDBN} acknowledges this reponse, | |
35140 | but neither the stub nor @value{GDBN} shall send or expect further | |
35141 | @samp{+}/@samp{-} acknowledgments in the current connection. | |
d57350ea | 35142 | @item @w{} |
a6f3e723 SL |
35143 | An empty reply indicates that the stub does not support no-acknowledgment mode. |
35144 | @end table | |
35145 | ||
be2a5f71 DJ |
35146 | @item qSupported @r{[}:@var{gdbfeature} @r{[};@var{gdbfeature}@r{]}@dots{} @r{]} |
35147 | @cindex supported packets, remote query | |
35148 | @cindex features of the remote protocol | |
35149 | @cindex @samp{qSupported} packet | |
0876f84a | 35150 | @anchor{qSupported} |
be2a5f71 DJ |
35151 | Tell the remote stub about features supported by @value{GDBN}, and |
35152 | query the stub for features it supports. This packet allows | |
35153 | @value{GDBN} and the remote stub to take advantage of each others' | |
35154 | features. @samp{qSupported} also consolidates multiple feature probes | |
35155 | at startup, to improve @value{GDBN} performance---a single larger | |
35156 | packet performs better than multiple smaller probe packets on | |
35157 | high-latency links. Some features may enable behavior which must not | |
35158 | be on by default, e.g.@: because it would confuse older clients or | |
35159 | stubs. Other features may describe packets which could be | |
35160 | automatically probed for, but are not. These features must be | |
35161 | reported before @value{GDBN} will use them. This ``default | |
35162 | unsupported'' behavior is not appropriate for all packets, but it | |
35163 | helps to keep the initial connection time under control with new | |
35164 | versions of @value{GDBN} which support increasing numbers of packets. | |
35165 | ||
35166 | Reply: | |
35167 | @table @samp | |
35168 | @item @var{stubfeature} @r{[};@var{stubfeature}@r{]}@dots{} | |
35169 | The stub supports or does not support each returned @var{stubfeature}, | |
35170 | depending on the form of each @var{stubfeature} (see below for the | |
35171 | possible forms). | |
d57350ea | 35172 | @item @w{} |
be2a5f71 DJ |
35173 | An empty reply indicates that @samp{qSupported} is not recognized, |
35174 | or that no features needed to be reported to @value{GDBN}. | |
35175 | @end table | |
35176 | ||
35177 | The allowed forms for each feature (either a @var{gdbfeature} in the | |
35178 | @samp{qSupported} packet, or a @var{stubfeature} in the response) | |
35179 | are: | |
35180 | ||
35181 | @table @samp | |
35182 | @item @var{name}=@var{value} | |
35183 | The remote protocol feature @var{name} is supported, and associated | |
35184 | with the specified @var{value}. The format of @var{value} depends | |
35185 | on the feature, but it must not include a semicolon. | |
35186 | @item @var{name}+ | |
35187 | The remote protocol feature @var{name} is supported, and does not | |
35188 | need an associated value. | |
35189 | @item @var{name}- | |
35190 | The remote protocol feature @var{name} is not supported. | |
35191 | @item @var{name}? | |
35192 | The remote protocol feature @var{name} may be supported, and | |
35193 | @value{GDBN} should auto-detect support in some other way when it is | |
35194 | needed. This form will not be used for @var{gdbfeature} notifications, | |
35195 | but may be used for @var{stubfeature} responses. | |
35196 | @end table | |
35197 | ||
35198 | Whenever the stub receives a @samp{qSupported} request, the | |
35199 | supplied set of @value{GDBN} features should override any previous | |
35200 | request. This allows @value{GDBN} to put the stub in a known | |
35201 | state, even if the stub had previously been communicating with | |
35202 | a different version of @value{GDBN}. | |
35203 | ||
b90a069a SL |
35204 | The following values of @var{gdbfeature} (for the packet sent by @value{GDBN}) |
35205 | are defined: | |
35206 | ||
35207 | @table @samp | |
35208 | @item multiprocess | |
35209 | This feature indicates whether @value{GDBN} supports multiprocess | |
35210 | extensions to the remote protocol. @value{GDBN} does not use such | |
35211 | extensions unless the stub also reports that it supports them by | |
35212 | including @samp{multiprocess+} in its @samp{qSupported} reply. | |
35213 | @xref{multiprocess extensions}, for details. | |
c8d5aac9 L |
35214 | |
35215 | @item xmlRegisters | |
35216 | This feature indicates that @value{GDBN} supports the XML target | |
35217 | description. If the stub sees @samp{xmlRegisters=} with target | |
35218 | specific strings separated by a comma, it will report register | |
35219 | description. | |
dde08ee1 PA |
35220 | |
35221 | @item qRelocInsn | |
35222 | This feature indicates whether @value{GDBN} supports the | |
35223 | @samp{qRelocInsn} packet (@pxref{Tracepoint Packets,,Relocate | |
35224 | instruction reply packet}). | |
b90a069a SL |
35225 | @end table |
35226 | ||
35227 | Stubs should ignore any unknown values for | |
be2a5f71 DJ |
35228 | @var{gdbfeature}. Any @value{GDBN} which sends a @samp{qSupported} |
35229 | packet supports receiving packets of unlimited length (earlier | |
b90a069a | 35230 | versions of @value{GDBN} may reject overly long responses). Additional values |
be2a5f71 DJ |
35231 | for @var{gdbfeature} may be defined in the future to let the stub take |
35232 | advantage of new features in @value{GDBN}, e.g.@: incompatible | |
b90a069a SL |
35233 | improvements in the remote protocol---the @samp{multiprocess} feature is |
35234 | an example of such a feature. The stub's reply should be independent | |
be2a5f71 DJ |
35235 | of the @var{gdbfeature} entries sent by @value{GDBN}; first @value{GDBN} |
35236 | describes all the features it supports, and then the stub replies with | |
35237 | all the features it supports. | |
35238 | ||
35239 | Similarly, @value{GDBN} will silently ignore unrecognized stub feature | |
35240 | responses, as long as each response uses one of the standard forms. | |
35241 | ||
35242 | Some features are flags. A stub which supports a flag feature | |
35243 | should respond with a @samp{+} form response. Other features | |
35244 | require values, and the stub should respond with an @samp{=} | |
35245 | form response. | |
35246 | ||
35247 | Each feature has a default value, which @value{GDBN} will use if | |
35248 | @samp{qSupported} is not available or if the feature is not mentioned | |
35249 | in the @samp{qSupported} response. The default values are fixed; a | |
35250 | stub is free to omit any feature responses that match the defaults. | |
35251 | ||
35252 | Not all features can be probed, but for those which can, the probing | |
35253 | mechanism is useful: in some cases, a stub's internal | |
35254 | architecture may not allow the protocol layer to know some information | |
35255 | about the underlying target in advance. This is especially common in | |
35256 | stubs which may be configured for multiple targets. | |
35257 | ||
35258 | These are the currently defined stub features and their properties: | |
35259 | ||
cfa9d6d9 | 35260 | @multitable @columnfractions 0.35 0.2 0.12 0.2 |
be2a5f71 DJ |
35261 | @c NOTE: The first row should be @headitem, but we do not yet require |
35262 | @c a new enough version of Texinfo (4.7) to use @headitem. | |
0876f84a | 35263 | @item Feature Name |
be2a5f71 DJ |
35264 | @tab Value Required |
35265 | @tab Default | |
35266 | @tab Probe Allowed | |
35267 | ||
35268 | @item @samp{PacketSize} | |
35269 | @tab Yes | |
35270 | @tab @samp{-} | |
35271 | @tab No | |
35272 | ||
0876f84a DJ |
35273 | @item @samp{qXfer:auxv:read} |
35274 | @tab No | |
35275 | @tab @samp{-} | |
35276 | @tab Yes | |
35277 | ||
2ae8c8e7 MM |
35278 | @item @samp{qXfer:btrace:read} |
35279 | @tab No | |
35280 | @tab @samp{-} | |
35281 | @tab Yes | |
35282 | ||
23181151 DJ |
35283 | @item @samp{qXfer:features:read} |
35284 | @tab No | |
35285 | @tab @samp{-} | |
35286 | @tab Yes | |
35287 | ||
cfa9d6d9 DJ |
35288 | @item @samp{qXfer:libraries:read} |
35289 | @tab No | |
35290 | @tab @samp{-} | |
35291 | @tab Yes | |
35292 | ||
85dc5a12 GB |
35293 | @item @samp{qXfer:libraries-svr4:read} |
35294 | @tab No | |
35295 | @tab @samp{-} | |
35296 | @tab Yes | |
35297 | ||
35298 | @item @samp{augmented-libraries-svr4-read} | |
35299 | @tab No | |
35300 | @tab @samp{-} | |
35301 | @tab No | |
35302 | ||
68437a39 DJ |
35303 | @item @samp{qXfer:memory-map:read} |
35304 | @tab No | |
35305 | @tab @samp{-} | |
35306 | @tab Yes | |
35307 | ||
0fb4aa4b PA |
35308 | @item @samp{qXfer:sdata:read} |
35309 | @tab No | |
35310 | @tab @samp{-} | |
35311 | @tab Yes | |
35312 | ||
0e7f50da UW |
35313 | @item @samp{qXfer:spu:read} |
35314 | @tab No | |
35315 | @tab @samp{-} | |
35316 | @tab Yes | |
35317 | ||
35318 | @item @samp{qXfer:spu:write} | |
35319 | @tab No | |
35320 | @tab @samp{-} | |
35321 | @tab Yes | |
35322 | ||
4aa995e1 PA |
35323 | @item @samp{qXfer:siginfo:read} |
35324 | @tab No | |
35325 | @tab @samp{-} | |
35326 | @tab Yes | |
35327 | ||
35328 | @item @samp{qXfer:siginfo:write} | |
35329 | @tab No | |
35330 | @tab @samp{-} | |
35331 | @tab Yes | |
35332 | ||
dc146f7c VP |
35333 | @item @samp{qXfer:threads:read} |
35334 | @tab No | |
35335 | @tab @samp{-} | |
35336 | @tab Yes | |
35337 | ||
b3b9301e PA |
35338 | @item @samp{qXfer:traceframe-info:read} |
35339 | @tab No | |
35340 | @tab @samp{-} | |
35341 | @tab Yes | |
35342 | ||
169081d0 TG |
35343 | @item @samp{qXfer:uib:read} |
35344 | @tab No | |
35345 | @tab @samp{-} | |
35346 | @tab Yes | |
35347 | ||
78d85199 YQ |
35348 | @item @samp{qXfer:fdpic:read} |
35349 | @tab No | |
35350 | @tab @samp{-} | |
35351 | @tab Yes | |
dc146f7c | 35352 | |
2ae8c8e7 MM |
35353 | @item @samp{Qbtrace:off} |
35354 | @tab Yes | |
35355 | @tab @samp{-} | |
35356 | @tab Yes | |
35357 | ||
35358 | @item @samp{Qbtrace:bts} | |
35359 | @tab Yes | |
35360 | @tab @samp{-} | |
35361 | @tab Yes | |
35362 | ||
8b23ecc4 SL |
35363 | @item @samp{QNonStop} |
35364 | @tab No | |
35365 | @tab @samp{-} | |
35366 | @tab Yes | |
35367 | ||
89be2091 DJ |
35368 | @item @samp{QPassSignals} |
35369 | @tab No | |
35370 | @tab @samp{-} | |
35371 | @tab Yes | |
35372 | ||
a6f3e723 SL |
35373 | @item @samp{QStartNoAckMode} |
35374 | @tab No | |
35375 | @tab @samp{-} | |
35376 | @tab Yes | |
35377 | ||
b90a069a SL |
35378 | @item @samp{multiprocess} |
35379 | @tab No | |
35380 | @tab @samp{-} | |
35381 | @tab No | |
35382 | ||
83364271 LM |
35383 | @item @samp{ConditionalBreakpoints} |
35384 | @tab No | |
35385 | @tab @samp{-} | |
35386 | @tab No | |
35387 | ||
782b2b07 SS |
35388 | @item @samp{ConditionalTracepoints} |
35389 | @tab No | |
35390 | @tab @samp{-} | |
35391 | @tab No | |
35392 | ||
0d772ac9 MS |
35393 | @item @samp{ReverseContinue} |
35394 | @tab No | |
2f8132f3 | 35395 | @tab @samp{-} |
0d772ac9 MS |
35396 | @tab No |
35397 | ||
35398 | @item @samp{ReverseStep} | |
35399 | @tab No | |
2f8132f3 | 35400 | @tab @samp{-} |
0d772ac9 MS |
35401 | @tab No |
35402 | ||
409873ef SS |
35403 | @item @samp{TracepointSource} |
35404 | @tab No | |
35405 | @tab @samp{-} | |
35406 | @tab No | |
35407 | ||
d1feda86 YQ |
35408 | @item @samp{QAgent} |
35409 | @tab No | |
35410 | @tab @samp{-} | |
35411 | @tab No | |
35412 | ||
d914c394 SS |
35413 | @item @samp{QAllow} |
35414 | @tab No | |
35415 | @tab @samp{-} | |
35416 | @tab No | |
35417 | ||
03583c20 UW |
35418 | @item @samp{QDisableRandomization} |
35419 | @tab No | |
35420 | @tab @samp{-} | |
35421 | @tab No | |
35422 | ||
d248b706 KY |
35423 | @item @samp{EnableDisableTracepoints} |
35424 | @tab No | |
35425 | @tab @samp{-} | |
35426 | @tab No | |
35427 | ||
f6f899bf HAQ |
35428 | @item @samp{QTBuffer:size} |
35429 | @tab No | |
35430 | @tab @samp{-} | |
35431 | @tab No | |
35432 | ||
3065dfb6 SS |
35433 | @item @samp{tracenz} |
35434 | @tab No | |
35435 | @tab @samp{-} | |
35436 | @tab No | |
35437 | ||
d3ce09f5 SS |
35438 | @item @samp{BreakpointCommands} |
35439 | @tab No | |
35440 | @tab @samp{-} | |
35441 | @tab No | |
35442 | ||
be2a5f71 DJ |
35443 | @end multitable |
35444 | ||
35445 | These are the currently defined stub features, in more detail: | |
35446 | ||
35447 | @table @samp | |
35448 | @cindex packet size, remote protocol | |
35449 | @item PacketSize=@var{bytes} | |
35450 | The remote stub can accept packets up to at least @var{bytes} in | |
35451 | length. @value{GDBN} will send packets up to this size for bulk | |
35452 | transfers, and will never send larger packets. This is a limit on the | |
35453 | data characters in the packet, including the frame and checksum. | |
35454 | There is no trailing NUL byte in a remote protocol packet; if the stub | |
35455 | stores packets in a NUL-terminated format, it should allow an extra | |
35456 | byte in its buffer for the NUL. If this stub feature is not supported, | |
35457 | @value{GDBN} guesses based on the size of the @samp{g} packet response. | |
35458 | ||
0876f84a DJ |
35459 | @item qXfer:auxv:read |
35460 | The remote stub understands the @samp{qXfer:auxv:read} packet | |
35461 | (@pxref{qXfer auxiliary vector read}). | |
35462 | ||
2ae8c8e7 MM |
35463 | @item qXfer:btrace:read |
35464 | The remote stub understands the @samp{qXfer:btrace:read} | |
35465 | packet (@pxref{qXfer btrace read}). | |
35466 | ||
23181151 DJ |
35467 | @item qXfer:features:read |
35468 | The remote stub understands the @samp{qXfer:features:read} packet | |
35469 | (@pxref{qXfer target description read}). | |
35470 | ||
cfa9d6d9 DJ |
35471 | @item qXfer:libraries:read |
35472 | The remote stub understands the @samp{qXfer:libraries:read} packet | |
35473 | (@pxref{qXfer library list read}). | |
35474 | ||
2268b414 JK |
35475 | @item qXfer:libraries-svr4:read |
35476 | The remote stub understands the @samp{qXfer:libraries-svr4:read} packet | |
35477 | (@pxref{qXfer svr4 library list read}). | |
35478 | ||
85dc5a12 GB |
35479 | @item augmented-libraries-svr4-read |
35480 | The remote stub understands the augmented form of the | |
35481 | @samp{qXfer:libraries-svr4:read} packet | |
35482 | (@pxref{qXfer svr4 library list read}). | |
35483 | ||
23181151 DJ |
35484 | @item qXfer:memory-map:read |
35485 | The remote stub understands the @samp{qXfer:memory-map:read} packet | |
35486 | (@pxref{qXfer memory map read}). | |
35487 | ||
0fb4aa4b PA |
35488 | @item qXfer:sdata:read |
35489 | The remote stub understands the @samp{qXfer:sdata:read} packet | |
35490 | (@pxref{qXfer sdata read}). | |
35491 | ||
0e7f50da UW |
35492 | @item qXfer:spu:read |
35493 | The remote stub understands the @samp{qXfer:spu:read} packet | |
35494 | (@pxref{qXfer spu read}). | |
35495 | ||
35496 | @item qXfer:spu:write | |
35497 | The remote stub understands the @samp{qXfer:spu:write} packet | |
35498 | (@pxref{qXfer spu write}). | |
35499 | ||
4aa995e1 PA |
35500 | @item qXfer:siginfo:read |
35501 | The remote stub understands the @samp{qXfer:siginfo:read} packet | |
35502 | (@pxref{qXfer siginfo read}). | |
35503 | ||
35504 | @item qXfer:siginfo:write | |
35505 | The remote stub understands the @samp{qXfer:siginfo:write} packet | |
35506 | (@pxref{qXfer siginfo write}). | |
35507 | ||
dc146f7c VP |
35508 | @item qXfer:threads:read |
35509 | The remote stub understands the @samp{qXfer:threads:read} packet | |
35510 | (@pxref{qXfer threads read}). | |
35511 | ||
b3b9301e PA |
35512 | @item qXfer:traceframe-info:read |
35513 | The remote stub understands the @samp{qXfer:traceframe-info:read} | |
35514 | packet (@pxref{qXfer traceframe info read}). | |
35515 | ||
169081d0 TG |
35516 | @item qXfer:uib:read |
35517 | The remote stub understands the @samp{qXfer:uib:read} | |
35518 | packet (@pxref{qXfer unwind info block}). | |
35519 | ||
78d85199 YQ |
35520 | @item qXfer:fdpic:read |
35521 | The remote stub understands the @samp{qXfer:fdpic:read} | |
35522 | packet (@pxref{qXfer fdpic loadmap read}). | |
35523 | ||
8b23ecc4 SL |
35524 | @item QNonStop |
35525 | The remote stub understands the @samp{QNonStop} packet | |
35526 | (@pxref{QNonStop}). | |
35527 | ||
23181151 DJ |
35528 | @item QPassSignals |
35529 | The remote stub understands the @samp{QPassSignals} packet | |
35530 | (@pxref{QPassSignals}). | |
35531 | ||
a6f3e723 SL |
35532 | @item QStartNoAckMode |
35533 | The remote stub understands the @samp{QStartNoAckMode} packet and | |
35534 | prefers to operate in no-acknowledgment mode. @xref{Packet Acknowledgment}. | |
35535 | ||
b90a069a SL |
35536 | @item multiprocess |
35537 | @anchor{multiprocess extensions} | |
35538 | @cindex multiprocess extensions, in remote protocol | |
35539 | The remote stub understands the multiprocess extensions to the remote | |
35540 | protocol syntax. The multiprocess extensions affect the syntax of | |
35541 | thread IDs in both packets and replies (@pxref{thread-id syntax}), and | |
35542 | add process IDs to the @samp{D} packet and @samp{W} and @samp{X} | |
35543 | replies. Note that reporting this feature indicates support for the | |
35544 | syntactic extensions only, not that the stub necessarily supports | |
35545 | debugging of more than one process at a time. The stub must not use | |
35546 | multiprocess extensions in packet replies unless @value{GDBN} has also | |
35547 | indicated it supports them in its @samp{qSupported} request. | |
35548 | ||
07e059b5 VP |
35549 | @item qXfer:osdata:read |
35550 | The remote stub understands the @samp{qXfer:osdata:read} packet | |
35551 | ((@pxref{qXfer osdata read}). | |
35552 | ||
83364271 LM |
35553 | @item ConditionalBreakpoints |
35554 | The target accepts and implements evaluation of conditional expressions | |
35555 | defined for breakpoints. The target will only report breakpoint triggers | |
35556 | when such conditions are true (@pxref{Conditions, ,Break Conditions}). | |
35557 | ||
782b2b07 SS |
35558 | @item ConditionalTracepoints |
35559 | The remote stub accepts and implements conditional expressions defined | |
35560 | for tracepoints (@pxref{Tracepoint Conditions}). | |
35561 | ||
0d772ac9 MS |
35562 | @item ReverseContinue |
35563 | The remote stub accepts and implements the reverse continue packet | |
35564 | (@pxref{bc}). | |
35565 | ||
35566 | @item ReverseStep | |
35567 | The remote stub accepts and implements the reverse step packet | |
35568 | (@pxref{bs}). | |
35569 | ||
409873ef SS |
35570 | @item TracepointSource |
35571 | The remote stub understands the @samp{QTDPsrc} packet that supplies | |
35572 | the source form of tracepoint definitions. | |
35573 | ||
d1feda86 YQ |
35574 | @item QAgent |
35575 | The remote stub understands the @samp{QAgent} packet. | |
35576 | ||
d914c394 SS |
35577 | @item QAllow |
35578 | The remote stub understands the @samp{QAllow} packet. | |
35579 | ||
03583c20 UW |
35580 | @item QDisableRandomization |
35581 | The remote stub understands the @samp{QDisableRandomization} packet. | |
35582 | ||
0fb4aa4b PA |
35583 | @item StaticTracepoint |
35584 | @cindex static tracepoints, in remote protocol | |
35585 | The remote stub supports static tracepoints. | |
35586 | ||
1e4d1764 YQ |
35587 | @item InstallInTrace |
35588 | @anchor{install tracepoint in tracing} | |
35589 | The remote stub supports installing tracepoint in tracing. | |
35590 | ||
d248b706 KY |
35591 | @item EnableDisableTracepoints |
35592 | The remote stub supports the @samp{QTEnable} (@pxref{QTEnable}) and | |
35593 | @samp{QTDisable} (@pxref{QTDisable}) packets that allow tracepoints | |
35594 | to be enabled and disabled while a trace experiment is running. | |
35595 | ||
f6f899bf | 35596 | @item QTBuffer:size |
28abe188 | 35597 | The remote stub supports the @samp{QTBuffer:size} (@pxref{QTBuffer-size}) |
f6f899bf HAQ |
35598 | packet that allows to change the size of the trace buffer. |
35599 | ||
3065dfb6 SS |
35600 | @item tracenz |
35601 | @cindex string tracing, in remote protocol | |
35602 | The remote stub supports the @samp{tracenz} bytecode for collecting strings. | |
35603 | See @ref{Bytecode Descriptions} for details about the bytecode. | |
35604 | ||
d3ce09f5 SS |
35605 | @item BreakpointCommands |
35606 | @cindex breakpoint commands, in remote protocol | |
35607 | The remote stub supports running a breakpoint's command list itself, | |
35608 | rather than reporting the hit to @value{GDBN}. | |
35609 | ||
2ae8c8e7 MM |
35610 | @item Qbtrace:off |
35611 | The remote stub understands the @samp{Qbtrace:off} packet. | |
35612 | ||
35613 | @item Qbtrace:bts | |
35614 | The remote stub understands the @samp{Qbtrace:bts} packet. | |
35615 | ||
be2a5f71 DJ |
35616 | @end table |
35617 | ||
b8ff78ce | 35618 | @item qSymbol:: |
ff2587ec | 35619 | @cindex symbol lookup, remote request |
b8ff78ce | 35620 | @cindex @samp{qSymbol} packet |
ff2587ec WZ |
35621 | Notify the target that @value{GDBN} is prepared to serve symbol lookup |
35622 | requests. Accept requests from the target for the values of symbols. | |
fa93a9d8 JB |
35623 | |
35624 | Reply: | |
ff2587ec | 35625 | @table @samp |
b8ff78ce | 35626 | @item OK |
ff2587ec | 35627 | The target does not need to look up any (more) symbols. |
b8ff78ce | 35628 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
35629 | The target requests the value of symbol @var{sym_name} (hex encoded). |
35630 | @value{GDBN} may provide the value by using the | |
b8ff78ce JB |
35631 | @samp{qSymbol:@var{sym_value}:@var{sym_name}} message, described |
35632 | below. | |
ff2587ec | 35633 | @end table |
83761cbd | 35634 | |
b8ff78ce | 35635 | @item qSymbol:@var{sym_value}:@var{sym_name} |
ff2587ec WZ |
35636 | Set the value of @var{sym_name} to @var{sym_value}. |
35637 | ||
35638 | @var{sym_name} (hex encoded) is the name of a symbol whose value the | |
35639 | target has previously requested. | |
35640 | ||
35641 | @var{sym_value} (hex) is the value for symbol @var{sym_name}. If | |
35642 | @value{GDBN} cannot supply a value for @var{sym_name}, then this field | |
35643 | will be empty. | |
35644 | ||
35645 | Reply: | |
35646 | @table @samp | |
b8ff78ce | 35647 | @item OK |
ff2587ec | 35648 | The target does not need to look up any (more) symbols. |
b8ff78ce | 35649 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
35650 | The target requests the value of a new symbol @var{sym_name} (hex |
35651 | encoded). @value{GDBN} will continue to supply the values of symbols | |
35652 | (if available), until the target ceases to request them. | |
fa93a9d8 | 35653 | @end table |
0abb7bc7 | 35654 | |
00bf0b85 | 35655 | @item qTBuffer |
687e43a4 TT |
35656 | @itemx QTBuffer |
35657 | @itemx QTDisconnected | |
d5551862 | 35658 | @itemx QTDP |
409873ef | 35659 | @itemx QTDPsrc |
d5551862 | 35660 | @itemx QTDV |
00bf0b85 SS |
35661 | @itemx qTfP |
35662 | @itemx qTfV | |
9d29849a | 35663 | @itemx QTFrame |
405f8e94 SS |
35664 | @itemx qTMinFTPILen |
35665 | ||
9d29849a JB |
35666 | @xref{Tracepoint Packets}. |
35667 | ||
b90a069a | 35668 | @item qThreadExtraInfo,@var{thread-id} |
ff2587ec | 35669 | @cindex thread attributes info, remote request |
b8ff78ce | 35670 | @cindex @samp{qThreadExtraInfo} packet |
697aa1b7 EZ |
35671 | Obtain from the target OS a printable string description of thread |
35672 | attributes for the thread @var{thread-id}; see @ref{thread-id syntax}, | |
35673 | for the forms of @var{thread-id}. This | |
b8ff78ce JB |
35674 | string may contain anything that the target OS thinks is interesting |
35675 | for @value{GDBN} to tell the user about the thread. The string is | |
35676 | displayed in @value{GDBN}'s @code{info threads} display. Some | |
35677 | examples of possible thread extra info strings are @samp{Runnable}, or | |
35678 | @samp{Blocked on Mutex}. | |
ff2587ec WZ |
35679 | |
35680 | Reply: | |
35681 | @table @samp | |
b8ff78ce JB |
35682 | @item @var{XX}@dots{} |
35683 | Where @samp{@var{XX}@dots{}} is a hex encoding of @sc{ascii} data, | |
35684 | comprising the printable string containing the extra information about | |
35685 | the thread's attributes. | |
ff2587ec | 35686 | @end table |
814e32d7 | 35687 | |
aa56d27a JB |
35688 | (Note that the @code{qThreadExtraInfo} packet's name is separated from |
35689 | the command by a @samp{,}, not a @samp{:}, contrary to the naming | |
35690 | conventions above. Please don't use this packet as a model for new | |
35691 | packets.) | |
35692 | ||
f196051f | 35693 | @item QTNotes |
687e43a4 TT |
35694 | @itemx qTP |
35695 | @itemx QTSave | |
35696 | @itemx qTsP | |
35697 | @itemx qTsV | |
d5551862 | 35698 | @itemx QTStart |
9d29849a | 35699 | @itemx QTStop |
d248b706 KY |
35700 | @itemx QTEnable |
35701 | @itemx QTDisable | |
9d29849a JB |
35702 | @itemx QTinit |
35703 | @itemx QTro | |
35704 | @itemx qTStatus | |
d5551862 | 35705 | @itemx qTV |
0fb4aa4b PA |
35706 | @itemx qTfSTM |
35707 | @itemx qTsSTM | |
35708 | @itemx qTSTMat | |
9d29849a JB |
35709 | @xref{Tracepoint Packets}. |
35710 | ||
0876f84a DJ |
35711 | @item qXfer:@var{object}:read:@var{annex}:@var{offset},@var{length} |
35712 | @cindex read special object, remote request | |
35713 | @cindex @samp{qXfer} packet | |
68437a39 | 35714 | @anchor{qXfer read} |
0876f84a DJ |
35715 | Read uninterpreted bytes from the target's special data area |
35716 | identified by the keyword @var{object}. Request @var{length} bytes | |
35717 | starting at @var{offset} bytes into the data. The content and | |
0e7f50da | 35718 | encoding of @var{annex} is specific to @var{object}; it can supply |
0876f84a DJ |
35719 | additional details about what data to access. |
35720 | ||
35721 | Here are the specific requests of this form defined so far. All | |
35722 | @samp{qXfer:@var{object}:read:@dots{}} requests use the same reply | |
35723 | formats, listed below. | |
35724 | ||
35725 | @table @samp | |
35726 | @item qXfer:auxv:read::@var{offset},@var{length} | |
35727 | @anchor{qXfer auxiliary vector read} | |
35728 | Access the target's @dfn{auxiliary vector}. @xref{OS Information, | |
427c3a89 | 35729 | auxiliary vector}. Note @var{annex} must be empty. |
0876f84a DJ |
35730 | |
35731 | This packet is not probed by default; the remote stub must request it, | |
89be2091 | 35732 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). |
0876f84a | 35733 | |
2ae8c8e7 MM |
35734 | @item qXfer:btrace:read:@var{annex}:@var{offset},@var{length} |
35735 | @anchor{qXfer btrace read} | |
35736 | ||
35737 | Return a description of the current branch trace. | |
35738 | @xref{Branch Trace Format}. The annex part of the generic @samp{qXfer} | |
35739 | packet may have one of the following values: | |
35740 | ||
35741 | @table @code | |
35742 | @item all | |
35743 | Returns all available branch trace. | |
35744 | ||
35745 | @item new | |
35746 | Returns all available branch trace if the branch trace changed since | |
35747 | the last read request. | |
969c39fb MM |
35748 | |
35749 | @item delta | |
35750 | Returns the new branch trace since the last read request. Adds a new | |
35751 | block to the end of the trace that begins at zero and ends at the source | |
35752 | location of the first branch in the trace buffer. This extra block is | |
35753 | used to stitch traces together. | |
35754 | ||
35755 | If the trace buffer overflowed, returns an error indicating the overflow. | |
2ae8c8e7 MM |
35756 | @end table |
35757 | ||
35758 | This packet is not probed by default; the remote stub must request it | |
35759 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35760 | ||
23181151 DJ |
35761 | @item qXfer:features:read:@var{annex}:@var{offset},@var{length} |
35762 | @anchor{qXfer target description read} | |
35763 | Access the @dfn{target description}. @xref{Target Descriptions}. The | |
35764 | annex specifies which XML document to access. The main description is | |
35765 | always loaded from the @samp{target.xml} annex. | |
35766 | ||
35767 | This packet is not probed by default; the remote stub must request it, | |
35768 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35769 | ||
cfa9d6d9 DJ |
35770 | @item qXfer:libraries:read:@var{annex}:@var{offset},@var{length} |
35771 | @anchor{qXfer library list read} | |
35772 | Access the target's list of loaded libraries. @xref{Library List Format}. | |
35773 | The annex part of the generic @samp{qXfer} packet must be empty | |
35774 | (@pxref{qXfer read}). | |
35775 | ||
35776 | Targets which maintain a list of libraries in the program's memory do | |
35777 | not need to implement this packet; it is designed for platforms where | |
35778 | the operating system manages the list of loaded libraries. | |
35779 | ||
35780 | This packet is not probed by default; the remote stub must request it, | |
35781 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35782 | ||
2268b414 JK |
35783 | @item qXfer:libraries-svr4:read:@var{annex}:@var{offset},@var{length} |
35784 | @anchor{qXfer svr4 library list read} | |
35785 | Access the target's list of loaded libraries when the target is an SVR4 | |
35786 | platform. @xref{Library List Format for SVR4 Targets}. The annex part | |
85dc5a12 GB |
35787 | of the generic @samp{qXfer} packet must be empty unless the remote |
35788 | stub indicated it supports the augmented form of this packet | |
35789 | by supplying an appropriate @samp{qSupported} response | |
35790 | (@pxref{qXfer read}, @ref{qSupported}). | |
2268b414 JK |
35791 | |
35792 | This packet is optional for better performance on SVR4 targets. | |
35793 | @value{GDBN} uses memory read packets to read the SVR4 library list otherwise. | |
35794 | ||
35795 | This packet is not probed by default; the remote stub must request it, | |
35796 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35797 | ||
85dc5a12 GB |
35798 | If the remote stub indicates it supports the augmented form of this |
35799 | packet then the annex part of the generic @samp{qXfer} packet may | |
35800 | contain a semicolon-separated list of @samp{@var{name}=@var{value}} | |
35801 | arguments. The currently supported arguments are: | |
35802 | ||
35803 | @table @code | |
35804 | @item start=@var{address} | |
35805 | A hexadecimal number specifying the address of the @samp{struct | |
35806 | link_map} to start reading the library list from. If unset or zero | |
35807 | then the first @samp{struct link_map} in the library list will be | |
35808 | chosen as the starting point. | |
35809 | ||
35810 | @item prev=@var{address} | |
35811 | A hexadecimal number specifying the address of the @samp{struct | |
35812 | link_map} immediately preceding the @samp{struct link_map} | |
35813 | specified by the @samp{start} argument. If unset or zero then | |
35814 | the remote stub will expect that no @samp{struct link_map} | |
35815 | exists prior to the starting point. | |
35816 | ||
35817 | @end table | |
35818 | ||
35819 | Arguments that are not understood by the remote stub will be silently | |
35820 | ignored. | |
35821 | ||
68437a39 DJ |
35822 | @item qXfer:memory-map:read::@var{offset},@var{length} |
35823 | @anchor{qXfer memory map read} | |
79a6e687 | 35824 | Access the target's @dfn{memory-map}. @xref{Memory Map Format}. The |
68437a39 DJ |
35825 | annex part of the generic @samp{qXfer} packet must be empty |
35826 | (@pxref{qXfer read}). | |
35827 | ||
0e7f50da UW |
35828 | This packet is not probed by default; the remote stub must request it, |
35829 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35830 | ||
0fb4aa4b PA |
35831 | @item qXfer:sdata:read::@var{offset},@var{length} |
35832 | @anchor{qXfer sdata read} | |
35833 | ||
35834 | Read contents of the extra collected static tracepoint marker | |
35835 | information. The annex part of the generic @samp{qXfer} packet must | |
35836 | be empty (@pxref{qXfer read}). @xref{Tracepoint Actions,,Tracepoint | |
35837 | Action Lists}. | |
35838 | ||
35839 | This packet is not probed by default; the remote stub must request it, | |
35840 | by supplying an appropriate @samp{qSupported} response | |
35841 | (@pxref{qSupported}). | |
35842 | ||
4aa995e1 PA |
35843 | @item qXfer:siginfo:read::@var{offset},@var{length} |
35844 | @anchor{qXfer siginfo read} | |
35845 | Read contents of the extra signal information on the target | |
35846 | system. The annex part of the generic @samp{qXfer} packet must be | |
35847 | empty (@pxref{qXfer read}). | |
35848 | ||
35849 | This packet is not probed by default; the remote stub must request it, | |
35850 | by supplying an appropriate @samp{qSupported} response | |
35851 | (@pxref{qSupported}). | |
35852 | ||
0e7f50da UW |
35853 | @item qXfer:spu:read:@var{annex}:@var{offset},@var{length} |
35854 | @anchor{qXfer spu read} | |
35855 | Read contents of an @code{spufs} file on the target system. The | |
35856 | annex specifies which file to read; it must be of the form | |
35857 | @file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID | |
35858 | in the target process, and @var{name} identifes the @code{spufs} file | |
35859 | in that context to be accessed. | |
35860 | ||
68437a39 | 35861 | This packet is not probed by default; the remote stub must request it, |
07e059b5 VP |
35862 | by supplying an appropriate @samp{qSupported} response |
35863 | (@pxref{qSupported}). | |
35864 | ||
dc146f7c VP |
35865 | @item qXfer:threads:read::@var{offset},@var{length} |
35866 | @anchor{qXfer threads read} | |
35867 | Access the list of threads on target. @xref{Thread List Format}. The | |
35868 | annex part of the generic @samp{qXfer} packet must be empty | |
35869 | (@pxref{qXfer read}). | |
35870 | ||
35871 | This packet is not probed by default; the remote stub must request it, | |
35872 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35873 | ||
b3b9301e PA |
35874 | @item qXfer:traceframe-info:read::@var{offset},@var{length} |
35875 | @anchor{qXfer traceframe info read} | |
35876 | ||
35877 | Return a description of the current traceframe's contents. | |
35878 | @xref{Traceframe Info Format}. The annex part of the generic | |
35879 | @samp{qXfer} packet must be empty (@pxref{qXfer read}). | |
35880 | ||
35881 | This packet is not probed by default; the remote stub must request it, | |
35882 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35883 | ||
169081d0 TG |
35884 | @item qXfer:uib:read:@var{pc}:@var{offset},@var{length} |
35885 | @anchor{qXfer unwind info block} | |
35886 | ||
35887 | Return the unwind information block for @var{pc}. This packet is used | |
35888 | on OpenVMS/ia64 to ask the kernel unwind information. | |
35889 | ||
35890 | This packet is not probed by default. | |
35891 | ||
78d85199 YQ |
35892 | @item qXfer:fdpic:read:@var{annex}:@var{offset},@var{length} |
35893 | @anchor{qXfer fdpic loadmap read} | |
35894 | Read contents of @code{loadmap}s on the target system. The | |
35895 | annex, either @samp{exec} or @samp{interp}, specifies which @code{loadmap}, | |
35896 | executable @code{loadmap} or interpreter @code{loadmap} to read. | |
35897 | ||
35898 | This packet is not probed by default; the remote stub must request it, | |
35899 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35900 | ||
07e059b5 VP |
35901 | @item qXfer:osdata:read::@var{offset},@var{length} |
35902 | @anchor{qXfer osdata read} | |
697aa1b7 | 35903 | Access the target's @dfn{operating system information}. |
07e059b5 VP |
35904 | @xref{Operating System Information}. |
35905 | ||
68437a39 DJ |
35906 | @end table |
35907 | ||
0876f84a DJ |
35908 | Reply: |
35909 | @table @samp | |
35910 | @item m @var{data} | |
35911 | Data @var{data} (@pxref{Binary Data}) has been read from the | |
35912 | target. There may be more data at a higher address (although | |
35913 | it is permitted to return @samp{m} even for the last valid | |
35914 | block of data, as long as at least one byte of data was read). | |
697aa1b7 | 35915 | It is possible for @var{data} to have fewer bytes than the @var{length} in the |
0876f84a DJ |
35916 | request. |
35917 | ||
35918 | @item l @var{data} | |
35919 | Data @var{data} (@pxref{Binary Data}) has been read from the target. | |
697aa1b7 EZ |
35920 | There is no more data to be read. It is possible for @var{data} to |
35921 | have fewer bytes than the @var{length} in the request. | |
0876f84a DJ |
35922 | |
35923 | @item l | |
35924 | The @var{offset} in the request is at the end of the data. | |
35925 | There is no more data to be read. | |
35926 | ||
35927 | @item E00 | |
35928 | The request was malformed, or @var{annex} was invalid. | |
35929 | ||
35930 | @item E @var{nn} | |
35931 | The offset was invalid, or there was an error encountered reading the data. | |
697aa1b7 | 35932 | The @var{nn} part is a hex-encoded @code{errno} value. |
0876f84a | 35933 | |
d57350ea | 35934 | @item @w{} |
0876f84a DJ |
35935 | An empty reply indicates the @var{object} string was not recognized by |
35936 | the stub, or that the object does not support reading. | |
35937 | @end table | |
35938 | ||
35939 | @item qXfer:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{} | |
35940 | @cindex write data into object, remote request | |
4aa995e1 | 35941 | @anchor{qXfer write} |
0876f84a DJ |
35942 | Write uninterpreted bytes into the target's special data area |
35943 | identified by the keyword @var{object}, starting at @var{offset} bytes | |
697aa1b7 EZ |
35944 | into the data. The binary-encoded data (@pxref{Binary Data}) to be |
35945 | written is given by @var{data}@dots{}. The content and encoding of @var{annex} | |
0e7f50da | 35946 | is specific to @var{object}; it can supply additional details about what data |
0876f84a DJ |
35947 | to access. |
35948 | ||
0e7f50da UW |
35949 | Here are the specific requests of this form defined so far. All |
35950 | @samp{qXfer:@var{object}:write:@dots{}} requests use the same reply | |
35951 | formats, listed below. | |
35952 | ||
35953 | @table @samp | |
4aa995e1 PA |
35954 | @item qXfer:siginfo:write::@var{offset}:@var{data}@dots{} |
35955 | @anchor{qXfer siginfo write} | |
35956 | Write @var{data} to the extra signal information on the target system. | |
35957 | The annex part of the generic @samp{qXfer} packet must be | |
35958 | empty (@pxref{qXfer write}). | |
35959 | ||
35960 | This packet is not probed by default; the remote stub must request it, | |
35961 | by supplying an appropriate @samp{qSupported} response | |
35962 | (@pxref{qSupported}). | |
35963 | ||
84fcdf95 | 35964 | @item qXfer:spu:write:@var{annex}:@var{offset}:@var{data}@dots{} |
0e7f50da UW |
35965 | @anchor{qXfer spu write} |
35966 | Write @var{data} to an @code{spufs} file on the target system. The | |
35967 | annex specifies which file to write; it must be of the form | |
35968 | @file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID | |
35969 | in the target process, and @var{name} identifes the @code{spufs} file | |
35970 | in that context to be accessed. | |
35971 | ||
35972 | This packet is not probed by default; the remote stub must request it, | |
35973 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
35974 | @end table | |
0876f84a DJ |
35975 | |
35976 | Reply: | |
35977 | @table @samp | |
35978 | @item @var{nn} | |
35979 | @var{nn} (hex encoded) is the number of bytes written. | |
35980 | This may be fewer bytes than supplied in the request. | |
35981 | ||
35982 | @item E00 | |
35983 | The request was malformed, or @var{annex} was invalid. | |
35984 | ||
35985 | @item E @var{nn} | |
35986 | The offset was invalid, or there was an error encountered writing the data. | |
697aa1b7 | 35987 | The @var{nn} part is a hex-encoded @code{errno} value. |
0876f84a | 35988 | |
d57350ea | 35989 | @item @w{} |
0876f84a DJ |
35990 | An empty reply indicates the @var{object} string was not |
35991 | recognized by the stub, or that the object does not support writing. | |
35992 | @end table | |
35993 | ||
35994 | @item qXfer:@var{object}:@var{operation}:@dots{} | |
35995 | Requests of this form may be added in the future. When a stub does | |
35996 | not recognize the @var{object} keyword, or its support for | |
35997 | @var{object} does not recognize the @var{operation} keyword, the stub | |
35998 | must respond with an empty packet. | |
35999 | ||
0b16c5cf PA |
36000 | @item qAttached:@var{pid} |
36001 | @cindex query attached, remote request | |
36002 | @cindex @samp{qAttached} packet | |
36003 | Return an indication of whether the remote server attached to an | |
36004 | existing process or created a new process. When the multiprocess | |
36005 | protocol extensions are supported (@pxref{multiprocess extensions}), | |
36006 | @var{pid} is an integer in hexadecimal format identifying the target | |
36007 | process. Otherwise, @value{GDBN} will omit the @var{pid} field and | |
36008 | the query packet will be simplified as @samp{qAttached}. | |
36009 | ||
36010 | This query is used, for example, to know whether the remote process | |
36011 | should be detached or killed when a @value{GDBN} session is ended with | |
36012 | the @code{quit} command. | |
36013 | ||
36014 | Reply: | |
36015 | @table @samp | |
36016 | @item 1 | |
36017 | The remote server attached to an existing process. | |
36018 | @item 0 | |
36019 | The remote server created a new process. | |
36020 | @item E @var{NN} | |
36021 | A badly formed request or an error was encountered. | |
36022 | @end table | |
36023 | ||
2ae8c8e7 MM |
36024 | @item Qbtrace:bts |
36025 | Enable branch tracing for the current thread using bts tracing. | |
36026 | ||
36027 | Reply: | |
36028 | @table @samp | |
36029 | @item OK | |
36030 | Branch tracing has been enabled. | |
36031 | @item E.errtext | |
36032 | A badly formed request or an error was encountered. | |
36033 | @end table | |
36034 | ||
36035 | @item Qbtrace:off | |
36036 | Disable branch tracing for the current thread. | |
36037 | ||
36038 | Reply: | |
36039 | @table @samp | |
36040 | @item OK | |
36041 | Branch tracing has been disabled. | |
36042 | @item E.errtext | |
36043 | A badly formed request or an error was encountered. | |
36044 | @end table | |
36045 | ||
ee2d5c50 AC |
36046 | @end table |
36047 | ||
a1dcb23a DJ |
36048 | @node Architecture-Specific Protocol Details |
36049 | @section Architecture-Specific Protocol Details | |
36050 | ||
36051 | This section describes how the remote protocol is applied to specific | |
36052 | target architectures. Also see @ref{Standard Target Features}, for | |
36053 | details of XML target descriptions for each architecture. | |
36054 | ||
02b67415 MR |
36055 | @menu |
36056 | * ARM-Specific Protocol Details:: | |
36057 | * MIPS-Specific Protocol Details:: | |
36058 | @end menu | |
36059 | ||
36060 | @node ARM-Specific Protocol Details | |
36061 | @subsection @acronym{ARM}-specific Protocol Details | |
36062 | ||
36063 | @menu | |
36064 | * ARM Breakpoint Kinds:: | |
36065 | @end menu | |
a1dcb23a | 36066 | |
02b67415 MR |
36067 | @node ARM Breakpoint Kinds |
36068 | @subsubsection @acronym{ARM} Breakpoint Kinds | |
36069 | @cindex breakpoint kinds, @acronym{ARM} | |
a1dcb23a DJ |
36070 | |
36071 | These breakpoint kinds are defined for the @samp{Z0} and @samp{Z1} packets. | |
36072 | ||
36073 | @table @r | |
36074 | ||
36075 | @item 2 | |
36076 | 16-bit Thumb mode breakpoint. | |
36077 | ||
36078 | @item 3 | |
36079 | 32-bit Thumb mode (Thumb-2) breakpoint. | |
36080 | ||
36081 | @item 4 | |
02b67415 | 36082 | 32-bit @acronym{ARM} mode breakpoint. |
a1dcb23a DJ |
36083 | |
36084 | @end table | |
36085 | ||
02b67415 MR |
36086 | @node MIPS-Specific Protocol Details |
36087 | @subsection @acronym{MIPS}-specific Protocol Details | |
36088 | ||
36089 | @menu | |
36090 | * MIPS Register packet Format:: | |
4cc0665f | 36091 | * MIPS Breakpoint Kinds:: |
02b67415 | 36092 | @end menu |
a1dcb23a | 36093 | |
02b67415 MR |
36094 | @node MIPS Register packet Format |
36095 | @subsubsection @acronym{MIPS} Register Packet Format | |
eb17f351 | 36096 | @cindex register packet format, @acronym{MIPS} |
eb12ee30 | 36097 | |
b8ff78ce | 36098 | The following @code{g}/@code{G} packets have previously been defined. |
ee2d5c50 AC |
36099 | In the below, some thirty-two bit registers are transferred as |
36100 | sixty-four bits. Those registers should be zero/sign extended (which?) | |
599b237a BW |
36101 | to fill the space allocated. Register bytes are transferred in target |
36102 | byte order. The two nibbles within a register byte are transferred | |
02b67415 | 36103 | most-significant -- least-significant. |
eb12ee30 | 36104 | |
ee2d5c50 | 36105 | @table @r |
eb12ee30 | 36106 | |
8e04817f | 36107 | @item MIPS32 |
599b237a | 36108 | All registers are transferred as thirty-two bit quantities in the order: |
8e04817f AC |
36109 | 32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point |
36110 | registers; fsr; fir; fp. | |
eb12ee30 | 36111 | |
8e04817f | 36112 | @item MIPS64 |
599b237a | 36113 | All registers are transferred as sixty-four bit quantities (including |
8e04817f AC |
36114 | thirty-two bit registers such as @code{sr}). The ordering is the same |
36115 | as @code{MIPS32}. | |
eb12ee30 | 36116 | |
ee2d5c50 AC |
36117 | @end table |
36118 | ||
4cc0665f MR |
36119 | @node MIPS Breakpoint Kinds |
36120 | @subsubsection @acronym{MIPS} Breakpoint Kinds | |
36121 | @cindex breakpoint kinds, @acronym{MIPS} | |
36122 | ||
36123 | These breakpoint kinds are defined for the @samp{Z0} and @samp{Z1} packets. | |
36124 | ||
36125 | @table @r | |
36126 | ||
36127 | @item 2 | |
36128 | 16-bit @acronym{MIPS16} mode breakpoint. | |
36129 | ||
36130 | @item 3 | |
36131 | 16-bit @acronym{microMIPS} mode breakpoint. | |
36132 | ||
36133 | @item 4 | |
36134 | 32-bit standard @acronym{MIPS} mode breakpoint. | |
36135 | ||
36136 | @item 5 | |
36137 | 32-bit @acronym{microMIPS} mode breakpoint. | |
36138 | ||
36139 | @end table | |
36140 | ||
9d29849a JB |
36141 | @node Tracepoint Packets |
36142 | @section Tracepoint Packets | |
36143 | @cindex tracepoint packets | |
36144 | @cindex packets, tracepoint | |
36145 | ||
36146 | Here we describe the packets @value{GDBN} uses to implement | |
36147 | tracepoints (@pxref{Tracepoints}). | |
36148 | ||
36149 | @table @samp | |
36150 | ||
7a697b8d | 36151 | @item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}[:F@var{flen}][:X@var{len},@var{bytes}]@r{[}-@r{]} |
c614397c | 36152 | @cindex @samp{QTDP} packet |
9d29849a JB |
36153 | Create a new tracepoint, number @var{n}, at @var{addr}. If @var{ena} |
36154 | is @samp{E}, then the tracepoint is enabled; if it is @samp{D}, then | |
697aa1b7 EZ |
36155 | the tracepoint is disabled. The @var{step} gives the tracepoint's step |
36156 | count, and @var{pass} gives its pass count. If an @samp{F} is present, | |
7a697b8d SS |
36157 | then the tracepoint is to be a fast tracepoint, and the @var{flen} is |
36158 | the number of bytes that the target should copy elsewhere to make room | |
36159 | for the tracepoint. If an @samp{X} is present, it introduces a | |
36160 | tracepoint condition, which consists of a hexadecimal length, followed | |
36161 | by a comma and hex-encoded bytes, in a manner similar to action | |
36162 | encodings as described below. If the trailing @samp{-} is present, | |
36163 | further @samp{QTDP} packets will follow to specify this tracepoint's | |
36164 | actions. | |
9d29849a JB |
36165 | |
36166 | Replies: | |
36167 | @table @samp | |
36168 | @item OK | |
36169 | The packet was understood and carried out. | |
dde08ee1 PA |
36170 | @item qRelocInsn |
36171 | @xref{Tracepoint Packets,,Relocate instruction reply packet}. | |
d57350ea | 36172 | @item @w{} |
9d29849a JB |
36173 | The packet was not recognized. |
36174 | @end table | |
36175 | ||
36176 | @item QTDP:-@var{n}:@var{addr}:@r{[}S@r{]}@var{action}@dots{}@r{[}-@r{]} | |
697aa1b7 | 36177 | Define actions to be taken when a tracepoint is hit. The @var{n} and |
9d29849a JB |
36178 | @var{addr} must be the same as in the initial @samp{QTDP} packet for |
36179 | this tracepoint. This packet may only be sent immediately after | |
36180 | another @samp{QTDP} packet that ended with a @samp{-}. If the | |
36181 | trailing @samp{-} is present, further @samp{QTDP} packets will follow, | |
36182 | specifying more actions for this tracepoint. | |
36183 | ||
36184 | In the series of action packets for a given tracepoint, at most one | |
36185 | can have an @samp{S} before its first @var{action}. If such a packet | |
36186 | is sent, it and the following packets define ``while-stepping'' | |
36187 | actions. Any prior packets define ordinary actions --- that is, those | |
36188 | taken when the tracepoint is first hit. If no action packet has an | |
36189 | @samp{S}, then all the packets in the series specify ordinary | |
36190 | tracepoint actions. | |
36191 | ||
36192 | The @samp{@var{action}@dots{}} portion of the packet is a series of | |
36193 | actions, concatenated without separators. Each action has one of the | |
36194 | following forms: | |
36195 | ||
36196 | @table @samp | |
36197 | ||
36198 | @item R @var{mask} | |
697aa1b7 | 36199 | Collect the registers whose bits are set in @var{mask}, |
599b237a | 36200 | a hexadecimal number whose @var{i}'th bit is set if register number |
9d29849a JB |
36201 | @var{i} should be collected. (The least significant bit is numbered |
36202 | zero.) Note that @var{mask} may be any number of digits long; it may | |
36203 | not fit in a 32-bit word. | |
36204 | ||
36205 | @item M @var{basereg},@var{offset},@var{len} | |
36206 | Collect @var{len} bytes of memory starting at the address in register | |
36207 | number @var{basereg}, plus @var{offset}. If @var{basereg} is | |
36208 | @samp{-1}, then the range has a fixed address: @var{offset} is the | |
36209 | address of the lowest byte to collect. The @var{basereg}, | |
599b237a | 36210 | @var{offset}, and @var{len} parameters are all unsigned hexadecimal |
9d29849a JB |
36211 | values (the @samp{-1} value for @var{basereg} is a special case). |
36212 | ||
36213 | @item X @var{len},@var{expr} | |
36214 | Evaluate @var{expr}, whose length is @var{len}, and collect memory as | |
697aa1b7 | 36215 | it directs. The agent expression @var{expr} is as described in |
9d29849a JB |
36216 | @ref{Agent Expressions}. Each byte of the expression is encoded as a |
36217 | two-digit hex number in the packet; @var{len} is the number of bytes | |
36218 | in the expression (and thus one-half the number of hex digits in the | |
36219 | packet). | |
36220 | ||
36221 | @end table | |
36222 | ||
36223 | Any number of actions may be packed together in a single @samp{QTDP} | |
36224 | packet, as long as the packet does not exceed the maximum packet | |
c1947b85 JB |
36225 | length (400 bytes, for many stubs). There may be only one @samp{R} |
36226 | action per tracepoint, and it must precede any @samp{M} or @samp{X} | |
36227 | actions. Any registers referred to by @samp{M} and @samp{X} actions | |
36228 | must be collected by a preceding @samp{R} action. (The | |
36229 | ``while-stepping'' actions are treated as if they were attached to a | |
36230 | separate tracepoint, as far as these restrictions are concerned.) | |
9d29849a JB |
36231 | |
36232 | Replies: | |
36233 | @table @samp | |
36234 | @item OK | |
36235 | The packet was understood and carried out. | |
dde08ee1 PA |
36236 | @item qRelocInsn |
36237 | @xref{Tracepoint Packets,,Relocate instruction reply packet}. | |
d57350ea | 36238 | @item @w{} |
9d29849a JB |
36239 | The packet was not recognized. |
36240 | @end table | |
36241 | ||
409873ef SS |
36242 | @item QTDPsrc:@var{n}:@var{addr}:@var{type}:@var{start}:@var{slen}:@var{bytes} |
36243 | @cindex @samp{QTDPsrc} packet | |
36244 | Specify a source string of tracepoint @var{n} at address @var{addr}. | |
36245 | This is useful to get accurate reproduction of the tracepoints | |
697aa1b7 | 36246 | originally downloaded at the beginning of the trace run. The @var{type} |
409873ef SS |
36247 | is the name of the tracepoint part, such as @samp{cond} for the |
36248 | tracepoint's conditional expression (see below for a list of types), while | |
36249 | @var{bytes} is the string, encoded in hexadecimal. | |
36250 | ||
36251 | @var{start} is the offset of the @var{bytes} within the overall source | |
36252 | string, while @var{slen} is the total length of the source string. | |
36253 | This is intended for handling source strings that are longer than will | |
36254 | fit in a single packet. | |
36255 | @c Add detailed example when this info is moved into a dedicated | |
36256 | @c tracepoint descriptions section. | |
36257 | ||
36258 | The available string types are @samp{at} for the location, | |
36259 | @samp{cond} for the conditional, and @samp{cmd} for an action command. | |
36260 | @value{GDBN} sends a separate packet for each command in the action | |
36261 | list, in the same order in which the commands are stored in the list. | |
36262 | ||
36263 | The target does not need to do anything with source strings except | |
36264 | report them back as part of the replies to the @samp{qTfP}/@samp{qTsP} | |
36265 | query packets. | |
36266 | ||
36267 | Although this packet is optional, and @value{GDBN} will only send it | |
36268 | if the target replies with @samp{TracepointSource} @xref{General | |
36269 | Query Packets}, it makes both disconnected tracing and trace files | |
36270 | much easier to use. Otherwise the user must be careful that the | |
36271 | tracepoints in effect while looking at trace frames are identical to | |
36272 | the ones in effect during the trace run; even a small discrepancy | |
36273 | could cause @samp{tdump} not to work, or a particular trace frame not | |
36274 | be found. | |
36275 | ||
f61e138d SS |
36276 | @item QTDV:@var{n}:@var{value} |
36277 | @cindex define trace state variable, remote request | |
36278 | @cindex @samp{QTDV} packet | |
36279 | Create a new trace state variable, number @var{n}, with an initial | |
36280 | value of @var{value}, which is a 64-bit signed integer. Both @var{n} | |
36281 | and @var{value} are encoded as hexadecimal values. @value{GDBN} has | |
36282 | the option of not using this packet for initial values of zero; the | |
36283 | target should simply create the trace state variables as they are | |
36284 | mentioned in expressions. | |
36285 | ||
9d29849a | 36286 | @item QTFrame:@var{n} |
c614397c | 36287 | @cindex @samp{QTFrame} packet |
9d29849a JB |
36288 | Select the @var{n}'th tracepoint frame from the buffer, and use the |
36289 | register and memory contents recorded there to answer subsequent | |
36290 | request packets from @value{GDBN}. | |
36291 | ||
36292 | A successful reply from the stub indicates that the stub has found the | |
36293 | requested frame. The response is a series of parts, concatenated | |
36294 | without separators, describing the frame we selected. Each part has | |
36295 | one of the following forms: | |
36296 | ||
36297 | @table @samp | |
36298 | @item F @var{f} | |
36299 | The selected frame is number @var{n} in the trace frame buffer; | |
599b237a | 36300 | @var{f} is a hexadecimal number. If @var{f} is @samp{-1}, then there |
9d29849a JB |
36301 | was no frame matching the criteria in the request packet. |
36302 | ||
36303 | @item T @var{t} | |
36304 | The selected trace frame records a hit of tracepoint number @var{t}; | |
599b237a | 36305 | @var{t} is a hexadecimal number. |
9d29849a JB |
36306 | |
36307 | @end table | |
36308 | ||
36309 | @item QTFrame:pc:@var{addr} | |
36310 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
36311 | currently selected frame whose PC is @var{addr}; | |
599b237a | 36312 | @var{addr} is a hexadecimal number. |
9d29849a JB |
36313 | |
36314 | @item QTFrame:tdp:@var{t} | |
36315 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
36316 | currently selected frame that is a hit of tracepoint @var{t}; @var{t} | |
599b237a | 36317 | is a hexadecimal number. |
9d29849a JB |
36318 | |
36319 | @item QTFrame:range:@var{start}:@var{end} | |
36320 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
36321 | currently selected frame whose PC is between @var{start} (inclusive) | |
081dfbf7 | 36322 | and @var{end} (inclusive); @var{start} and @var{end} are hexadecimal |
9d29849a JB |
36323 | numbers. |
36324 | ||
36325 | @item QTFrame:outside:@var{start}:@var{end} | |
36326 | Like @samp{QTFrame:range:@var{start}:@var{end}}, but select the first | |
081dfbf7 | 36327 | frame @emph{outside} the given range of addresses (exclusive). |
9d29849a | 36328 | |
405f8e94 | 36329 | @item qTMinFTPILen |
c614397c | 36330 | @cindex @samp{qTMinFTPILen} packet |
405f8e94 SS |
36331 | This packet requests the minimum length of instruction at which a fast |
36332 | tracepoint (@pxref{Set Tracepoints}) may be placed. For instance, on | |
36333 | the 32-bit x86 architecture, it is possible to use a 4-byte jump, but | |
36334 | it depends on the target system being able to create trampolines in | |
36335 | the first 64K of memory, which might or might not be possible for that | |
36336 | system. So the reply to this packet will be 4 if it is able to | |
36337 | arrange for that. | |
36338 | ||
36339 | Replies: | |
36340 | ||
36341 | @table @samp | |
36342 | @item 0 | |
36343 | The minimum instruction length is currently unknown. | |
36344 | @item @var{length} | |
697aa1b7 EZ |
36345 | The minimum instruction length is @var{length}, where @var{length} |
36346 | is a hexadecimal number greater or equal to 1. A reply | |
36347 | of 1 means that a fast tracepoint may be placed on any instruction | |
36348 | regardless of size. | |
405f8e94 SS |
36349 | @item E |
36350 | An error has occurred. | |
d57350ea | 36351 | @item @w{} |
405f8e94 SS |
36352 | An empty reply indicates that the request is not supported by the stub. |
36353 | @end table | |
36354 | ||
9d29849a | 36355 | @item QTStart |
c614397c | 36356 | @cindex @samp{QTStart} packet |
dde08ee1 PA |
36357 | Begin the tracepoint experiment. Begin collecting data from |
36358 | tracepoint hits in the trace frame buffer. This packet supports the | |
36359 | @samp{qRelocInsn} reply (@pxref{Tracepoint Packets,,Relocate | |
36360 | instruction reply packet}). | |
9d29849a JB |
36361 | |
36362 | @item QTStop | |
c614397c | 36363 | @cindex @samp{QTStop} packet |
9d29849a JB |
36364 | End the tracepoint experiment. Stop collecting trace frames. |
36365 | ||
d248b706 KY |
36366 | @item QTEnable:@var{n}:@var{addr} |
36367 | @anchor{QTEnable} | |
c614397c | 36368 | @cindex @samp{QTEnable} packet |
d248b706 KY |
36369 | Enable tracepoint @var{n} at address @var{addr} in a started tracepoint |
36370 | experiment. If the tracepoint was previously disabled, then collection | |
36371 | of data from it will resume. | |
36372 | ||
36373 | @item QTDisable:@var{n}:@var{addr} | |
36374 | @anchor{QTDisable} | |
c614397c | 36375 | @cindex @samp{QTDisable} packet |
d248b706 KY |
36376 | Disable tracepoint @var{n} at address @var{addr} in a started tracepoint |
36377 | experiment. No more data will be collected from the tracepoint unless | |
36378 | @samp{QTEnable:@var{n}:@var{addr}} is subsequently issued. | |
36379 | ||
9d29849a | 36380 | @item QTinit |
c614397c | 36381 | @cindex @samp{QTinit} packet |
9d29849a JB |
36382 | Clear the table of tracepoints, and empty the trace frame buffer. |
36383 | ||
36384 | @item QTro:@var{start1},@var{end1}:@var{start2},@var{end2}:@dots{} | |
c614397c | 36385 | @cindex @samp{QTro} packet |
9d29849a JB |
36386 | Establish the given ranges of memory as ``transparent''. The stub |
36387 | will answer requests for these ranges from memory's current contents, | |
36388 | if they were not collected as part of the tracepoint hit. | |
36389 | ||
36390 | @value{GDBN} uses this to mark read-only regions of memory, like those | |
36391 | containing program code. Since these areas never change, they should | |
36392 | still have the same contents they did when the tracepoint was hit, so | |
36393 | there's no reason for the stub to refuse to provide their contents. | |
36394 | ||
d5551862 | 36395 | @item QTDisconnected:@var{value} |
c614397c | 36396 | @cindex @samp{QTDisconnected} packet |
d5551862 SS |
36397 | Set the choice to what to do with the tracing run when @value{GDBN} |
36398 | disconnects from the target. A @var{value} of 1 directs the target to | |
36399 | continue the tracing run, while 0 tells the target to stop tracing if | |
36400 | @value{GDBN} is no longer in the picture. | |
36401 | ||
9d29849a | 36402 | @item qTStatus |
c614397c | 36403 | @cindex @samp{qTStatus} packet |
9d29849a JB |
36404 | Ask the stub if there is a trace experiment running right now. |
36405 | ||
4daf5ac0 SS |
36406 | The reply has the form: |
36407 | ||
36408 | @table @samp | |
36409 | ||
36410 | @item T@var{running}@r{[};@var{field}@r{]}@dots{} | |
36411 | @var{running} is a single digit @code{1} if the trace is presently | |
36412 | running, or @code{0} if not. It is followed by semicolon-separated | |
36413 | optional fields that an agent may use to report additional status. | |
36414 | ||
36415 | @end table | |
36416 | ||
36417 | If the trace is not running, the agent may report any of several | |
36418 | explanations as one of the optional fields: | |
36419 | ||
36420 | @table @samp | |
36421 | ||
36422 | @item tnotrun:0 | |
36423 | No trace has been run yet. | |
36424 | ||
f196051f SS |
36425 | @item tstop[:@var{text}]:0 |
36426 | The trace was stopped by a user-originated stop command. The optional | |
36427 | @var{text} field is a user-supplied string supplied as part of the | |
36428 | stop command (for instance, an explanation of why the trace was | |
36429 | stopped manually). It is hex-encoded. | |
4daf5ac0 SS |
36430 | |
36431 | @item tfull:0 | |
36432 | The trace stopped because the trace buffer filled up. | |
36433 | ||
36434 | @item tdisconnected:0 | |
36435 | The trace stopped because @value{GDBN} disconnected from the target. | |
36436 | ||
36437 | @item tpasscount:@var{tpnum} | |
36438 | The trace stopped because tracepoint @var{tpnum} exceeded its pass count. | |
36439 | ||
6c28cbf2 SS |
36440 | @item terror:@var{text}:@var{tpnum} |
36441 | The trace stopped because tracepoint @var{tpnum} had an error. The | |
36442 | string @var{text} is available to describe the nature of the error | |
697aa1b7 EZ |
36443 | (for instance, a divide by zero in the condition expression); it |
36444 | is hex encoded. | |
6c28cbf2 | 36445 | |
4daf5ac0 SS |
36446 | @item tunknown:0 |
36447 | The trace stopped for some other reason. | |
36448 | ||
36449 | @end table | |
36450 | ||
33da3f1c SS |
36451 | Additional optional fields supply statistical and other information. |
36452 | Although not required, they are extremely useful for users monitoring | |
36453 | the progress of a trace run. If a trace has stopped, and these | |
36454 | numbers are reported, they must reflect the state of the just-stopped | |
36455 | trace. | |
4daf5ac0 | 36456 | |
9d29849a | 36457 | @table @samp |
4daf5ac0 SS |
36458 | |
36459 | @item tframes:@var{n} | |
36460 | The number of trace frames in the buffer. | |
36461 | ||
36462 | @item tcreated:@var{n} | |
36463 | The total number of trace frames created during the run. This may | |
36464 | be larger than the trace frame count, if the buffer is circular. | |
36465 | ||
36466 | @item tsize:@var{n} | |
36467 | The total size of the trace buffer, in bytes. | |
36468 | ||
36469 | @item tfree:@var{n} | |
36470 | The number of bytes still unused in the buffer. | |
36471 | ||
33da3f1c SS |
36472 | @item circular:@var{n} |
36473 | The value of the circular trace buffer flag. @code{1} means that the | |
36474 | trace buffer is circular and old trace frames will be discarded if | |
36475 | necessary to make room, @code{0} means that the trace buffer is linear | |
36476 | and may fill up. | |
36477 | ||
36478 | @item disconn:@var{n} | |
36479 | The value of the disconnected tracing flag. @code{1} means that | |
36480 | tracing will continue after @value{GDBN} disconnects, @code{0} means | |
36481 | that the trace run will stop. | |
36482 | ||
9d29849a JB |
36483 | @end table |
36484 | ||
f196051f SS |
36485 | @item qTP:@var{tp}:@var{addr} |
36486 | @cindex tracepoint status, remote request | |
36487 | @cindex @samp{qTP} packet | |
36488 | Ask the stub for the current state of tracepoint number @var{tp} at | |
36489 | address @var{addr}. | |
36490 | ||
36491 | Replies: | |
36492 | @table @samp | |
36493 | @item V@var{hits}:@var{usage} | |
36494 | The tracepoint has been hit @var{hits} times so far during the trace | |
36495 | run, and accounts for @var{usage} in the trace buffer. Note that | |
36496 | @code{while-stepping} steps are not counted as separate hits, but the | |
36497 | steps' space consumption is added into the usage number. | |
36498 | ||
36499 | @end table | |
36500 | ||
f61e138d SS |
36501 | @item qTV:@var{var} |
36502 | @cindex trace state variable value, remote request | |
36503 | @cindex @samp{qTV} packet | |
36504 | Ask the stub for the value of the trace state variable number @var{var}. | |
36505 | ||
36506 | Replies: | |
36507 | @table @samp | |
36508 | @item V@var{value} | |
36509 | The value of the variable is @var{value}. This will be the current | |
36510 | value of the variable if the user is examining a running target, or a | |
36511 | saved value if the variable was collected in the trace frame that the | |
36512 | user is looking at. Note that multiple requests may result in | |
36513 | different reply values, such as when requesting values while the | |
36514 | program is running. | |
36515 | ||
36516 | @item U | |
36517 | The value of the variable is unknown. This would occur, for example, | |
36518 | if the user is examining a trace frame in which the requested variable | |
36519 | was not collected. | |
9d29849a JB |
36520 | @end table |
36521 | ||
d5551862 | 36522 | @item qTfP |
c614397c | 36523 | @cindex @samp{qTfP} packet |
d5551862 | 36524 | @itemx qTsP |
c614397c | 36525 | @cindex @samp{qTsP} packet |
d5551862 SS |
36526 | These packets request data about tracepoints that are being used by |
36527 | the target. @value{GDBN} sends @code{qTfP} to get the first piece | |
36528 | of data, and multiple @code{qTsP} to get additional pieces. Replies | |
36529 | to these packets generally take the form of the @code{QTDP} packets | |
36530 | that define tracepoints. (FIXME add detailed syntax) | |
36531 | ||
00bf0b85 | 36532 | @item qTfV |
c614397c | 36533 | @cindex @samp{qTfV} packet |
00bf0b85 | 36534 | @itemx qTsV |
c614397c | 36535 | @cindex @samp{qTsV} packet |
00bf0b85 SS |
36536 | These packets request data about trace state variables that are on the |
36537 | target. @value{GDBN} sends @code{qTfV} to get the first vari of data, | |
36538 | and multiple @code{qTsV} to get additional variables. Replies to | |
36539 | these packets follow the syntax of the @code{QTDV} packets that define | |
36540 | trace state variables. | |
36541 | ||
0fb4aa4b PA |
36542 | @item qTfSTM |
36543 | @itemx qTsSTM | |
16bdd41f YQ |
36544 | @anchor{qTfSTM} |
36545 | @anchor{qTsSTM} | |
c614397c YQ |
36546 | @cindex @samp{qTfSTM} packet |
36547 | @cindex @samp{qTsSTM} packet | |
0fb4aa4b PA |
36548 | These packets request data about static tracepoint markers that exist |
36549 | in the target program. @value{GDBN} sends @code{qTfSTM} to get the | |
36550 | first piece of data, and multiple @code{qTsSTM} to get additional | |
36551 | pieces. Replies to these packets take the following form: | |
36552 | ||
36553 | Reply: | |
36554 | @table @samp | |
36555 | @item m @var{address}:@var{id}:@var{extra} | |
36556 | A single marker | |
36557 | @item m @var{address}:@var{id}:@var{extra},@var{address}:@var{id}:@var{extra}@dots{} | |
36558 | a comma-separated list of markers | |
36559 | @item l | |
36560 | (lower case letter @samp{L}) denotes end of list. | |
36561 | @item E @var{nn} | |
697aa1b7 | 36562 | An error occurred. The error number @var{nn} is given as hex digits. |
d57350ea | 36563 | @item @w{} |
0fb4aa4b PA |
36564 | An empty reply indicates that the request is not supported by the |
36565 | stub. | |
36566 | @end table | |
36567 | ||
697aa1b7 | 36568 | The @var{address} is encoded in hex; |
0fb4aa4b PA |
36569 | @var{id} and @var{extra} are strings encoded in hex. |
36570 | ||
36571 | In response to each query, the target will reply with a list of one or | |
36572 | more markers, separated by commas. @value{GDBN} will respond to each | |
36573 | reply with a request for more markers (using the @samp{qs} form of the | |
36574 | query), until the target responds with @samp{l} (lower-case ell, for | |
36575 | @dfn{last}). | |
36576 | ||
36577 | @item qTSTMat:@var{address} | |
16bdd41f | 36578 | @anchor{qTSTMat} |
c614397c | 36579 | @cindex @samp{qTSTMat} packet |
0fb4aa4b PA |
36580 | This packets requests data about static tracepoint markers in the |
36581 | target program at @var{address}. Replies to this packet follow the | |
36582 | syntax of the @samp{qTfSTM} and @code{qTsSTM} packets that list static | |
36583 | tracepoint markers. | |
36584 | ||
00bf0b85 | 36585 | @item QTSave:@var{filename} |
c614397c | 36586 | @cindex @samp{QTSave} packet |
00bf0b85 | 36587 | This packet directs the target to save trace data to the file name |
697aa1b7 | 36588 | @var{filename} in the target's filesystem. The @var{filename} is encoded |
00bf0b85 SS |
36589 | as a hex string; the interpretation of the file name (relative vs |
36590 | absolute, wild cards, etc) is up to the target. | |
36591 | ||
36592 | @item qTBuffer:@var{offset},@var{len} | |
c614397c | 36593 | @cindex @samp{qTBuffer} packet |
00bf0b85 SS |
36594 | Return up to @var{len} bytes of the current contents of trace buffer, |
36595 | starting at @var{offset}. The trace buffer is treated as if it were | |
36596 | a contiguous collection of traceframes, as per the trace file format. | |
36597 | The reply consists as many hex-encoded bytes as the target can deliver | |
36598 | in a packet; it is not an error to return fewer than were asked for. | |
36599 | A reply consisting of just @code{l} indicates that no bytes are | |
36600 | available. | |
36601 | ||
4daf5ac0 SS |
36602 | @item QTBuffer:circular:@var{value} |
36603 | This packet directs the target to use a circular trace buffer if | |
36604 | @var{value} is 1, or a linear buffer if the value is 0. | |
36605 | ||
f6f899bf | 36606 | @item QTBuffer:size:@var{size} |
28abe188 EZ |
36607 | @anchor{QTBuffer-size} |
36608 | @cindex @samp{QTBuffer size} packet | |
f6f899bf HAQ |
36609 | This packet directs the target to make the trace buffer be of size |
36610 | @var{size} if possible. A value of @code{-1} tells the target to | |
36611 | use whatever size it prefers. | |
36612 | ||
f196051f | 36613 | @item QTNotes:@r{[}@var{type}:@var{text}@r{]}@r{[};@var{type}:@var{text}@r{]}@dots{} |
c614397c | 36614 | @cindex @samp{QTNotes} packet |
f196051f SS |
36615 | This packet adds optional textual notes to the trace run. Allowable |
36616 | types include @code{user}, @code{notes}, and @code{tstop}, the | |
36617 | @var{text} fields are arbitrary strings, hex-encoded. | |
36618 | ||
f61e138d | 36619 | @end table |
9d29849a | 36620 | |
dde08ee1 PA |
36621 | @subsection Relocate instruction reply packet |
36622 | When installing fast tracepoints in memory, the target may need to | |
36623 | relocate the instruction currently at the tracepoint address to a | |
36624 | different address in memory. For most instructions, a simple copy is | |
36625 | enough, but, for example, call instructions that implicitly push the | |
36626 | return address on the stack, and relative branches or other | |
36627 | PC-relative instructions require offset adjustment, so that the effect | |
36628 | of executing the instruction at a different address is the same as if | |
36629 | it had executed in the original location. | |
36630 | ||
36631 | In response to several of the tracepoint packets, the target may also | |
36632 | respond with a number of intermediate @samp{qRelocInsn} request | |
36633 | packets before the final result packet, to have @value{GDBN} handle | |
36634 | this relocation operation. If a packet supports this mechanism, its | |
36635 | documentation will explicitly say so. See for example the above | |
36636 | descriptions for the @samp{QTStart} and @samp{QTDP} packets. The | |
36637 | format of the request is: | |
36638 | ||
36639 | @table @samp | |
36640 | @item qRelocInsn:@var{from};@var{to} | |
36641 | ||
36642 | This requests @value{GDBN} to copy instruction at address @var{from} | |
36643 | to address @var{to}, possibly adjusted so that executing the | |
36644 | instruction at @var{to} has the same effect as executing it at | |
36645 | @var{from}. @value{GDBN} writes the adjusted instruction to target | |
36646 | memory starting at @var{to}. | |
36647 | @end table | |
36648 | ||
36649 | Replies: | |
36650 | @table @samp | |
36651 | @item qRelocInsn:@var{adjusted_size} | |
697aa1b7 | 36652 | Informs the stub the relocation is complete. The @var{adjusted_size} is |
dde08ee1 PA |
36653 | the length in bytes of resulting relocated instruction sequence. |
36654 | @item E @var{NN} | |
36655 | A badly formed request was detected, or an error was encountered while | |
36656 | relocating the instruction. | |
36657 | @end table | |
36658 | ||
a6b151f1 DJ |
36659 | @node Host I/O Packets |
36660 | @section Host I/O Packets | |
36661 | @cindex Host I/O, remote protocol | |
36662 | @cindex file transfer, remote protocol | |
36663 | ||
36664 | The @dfn{Host I/O} packets allow @value{GDBN} to perform I/O | |
36665 | operations on the far side of a remote link. For example, Host I/O is | |
36666 | used to upload and download files to a remote target with its own | |
36667 | filesystem. Host I/O uses the same constant values and data structure | |
36668 | layout as the target-initiated File-I/O protocol. However, the | |
36669 | Host I/O packets are structured differently. The target-initiated | |
36670 | protocol relies on target memory to store parameters and buffers. | |
36671 | Host I/O requests are initiated by @value{GDBN}, and the | |
36672 | target's memory is not involved. @xref{File-I/O Remote Protocol | |
36673 | Extension}, for more details on the target-initiated protocol. | |
36674 | ||
36675 | The Host I/O request packets all encode a single operation along with | |
36676 | its arguments. They have this format: | |
36677 | ||
36678 | @table @samp | |
36679 | ||
36680 | @item vFile:@var{operation}: @var{parameter}@dots{} | |
36681 | @var{operation} is the name of the particular request; the target | |
36682 | should compare the entire packet name up to the second colon when checking | |
36683 | for a supported operation. The format of @var{parameter} depends on | |
36684 | the operation. Numbers are always passed in hexadecimal. Negative | |
36685 | numbers have an explicit minus sign (i.e.@: two's complement is not | |
36686 | used). Strings (e.g.@: filenames) are encoded as a series of | |
36687 | hexadecimal bytes. The last argument to a system call may be a | |
36688 | buffer of escaped binary data (@pxref{Binary Data}). | |
36689 | ||
36690 | @end table | |
36691 | ||
36692 | The valid responses to Host I/O packets are: | |
36693 | ||
36694 | @table @samp | |
36695 | ||
36696 | @item F @var{result} [, @var{errno}] [; @var{attachment}] | |
36697 | @var{result} is the integer value returned by this operation, usually | |
36698 | non-negative for success and -1 for errors. If an error has occured, | |
697aa1b7 | 36699 | @var{errno} will be included in the result specifying a |
a6b151f1 DJ |
36700 | value defined by the File-I/O protocol (@pxref{Errno Values}). For |
36701 | operations which return data, @var{attachment} supplies the data as a | |
36702 | binary buffer. Binary buffers in response packets are escaped in the | |
36703 | normal way (@pxref{Binary Data}). See the individual packet | |
36704 | documentation for the interpretation of @var{result} and | |
36705 | @var{attachment}. | |
36706 | ||
d57350ea | 36707 | @item @w{} |
a6b151f1 DJ |
36708 | An empty response indicates that this operation is not recognized. |
36709 | ||
36710 | @end table | |
36711 | ||
36712 | These are the supported Host I/O operations: | |
36713 | ||
36714 | @table @samp | |
697aa1b7 EZ |
36715 | @item vFile:open: @var{filename}, @var{flags}, @var{mode} |
36716 | Open a file at @var{filename} and return a file descriptor for it, or | |
36717 | return -1 if an error occurs. The @var{filename} is a string, | |
a6b151f1 DJ |
36718 | @var{flags} is an integer indicating a mask of open flags |
36719 | (@pxref{Open Flags}), and @var{mode} is an integer indicating a mask | |
36720 | of mode bits to use if the file is created (@pxref{mode_t Values}). | |
c1c25a1a | 36721 | @xref{open}, for details of the open flags and mode values. |
a6b151f1 DJ |
36722 | |
36723 | @item vFile:close: @var{fd} | |
36724 | Close the open file corresponding to @var{fd} and return 0, or | |
36725 | -1 if an error occurs. | |
36726 | ||
36727 | @item vFile:pread: @var{fd}, @var{count}, @var{offset} | |
36728 | Read data from the open file corresponding to @var{fd}. Up to | |
36729 | @var{count} bytes will be read from the file, starting at @var{offset} | |
36730 | relative to the start of the file. The target may read fewer bytes; | |
36731 | common reasons include packet size limits and an end-of-file | |
36732 | condition. The number of bytes read is returned. Zero should only be | |
36733 | returned for a successful read at the end of the file, or if | |
36734 | @var{count} was zero. | |
36735 | ||
36736 | The data read should be returned as a binary attachment on success. | |
36737 | If zero bytes were read, the response should include an empty binary | |
36738 | attachment (i.e.@: a trailing semicolon). The return value is the | |
36739 | number of target bytes read; the binary attachment may be longer if | |
36740 | some characters were escaped. | |
36741 | ||
36742 | @item vFile:pwrite: @var{fd}, @var{offset}, @var{data} | |
36743 | Write @var{data} (a binary buffer) to the open file corresponding | |
36744 | to @var{fd}. Start the write at @var{offset} from the start of the | |
36745 | file. Unlike many @code{write} system calls, there is no | |
36746 | separate @var{count} argument; the length of @var{data} in the | |
36747 | packet is used. @samp{vFile:write} returns the number of bytes written, | |
36748 | which may be shorter than the length of @var{data}, or -1 if an | |
36749 | error occurred. | |
36750 | ||
697aa1b7 EZ |
36751 | @item vFile:unlink: @var{filename} |
36752 | Delete the file at @var{filename} on the target. Return 0, | |
36753 | or -1 if an error occurs. The @var{filename} is a string. | |
a6b151f1 | 36754 | |
b9e7b9c3 UW |
36755 | @item vFile:readlink: @var{filename} |
36756 | Read value of symbolic link @var{filename} on the target. Return | |
36757 | the number of bytes read, or -1 if an error occurs. | |
36758 | ||
36759 | The data read should be returned as a binary attachment on success. | |
36760 | If zero bytes were read, the response should include an empty binary | |
36761 | attachment (i.e.@: a trailing semicolon). The return value is the | |
36762 | number of target bytes read; the binary attachment may be longer if | |
36763 | some characters were escaped. | |
36764 | ||
a6b151f1 DJ |
36765 | @end table |
36766 | ||
9a6253be KB |
36767 | @node Interrupts |
36768 | @section Interrupts | |
36769 | @cindex interrupts (remote protocol) | |
36770 | ||
36771 | When a program on the remote target is running, @value{GDBN} may | |
9a7071a8 JB |
36772 | attempt to interrupt it by sending a @samp{Ctrl-C}, @code{BREAK} or |
36773 | a @code{BREAK} followed by @code{g}, | |
36774 | control of which is specified via @value{GDBN}'s @samp{interrupt-sequence}. | |
9a6253be KB |
36775 | |
36776 | The precise meaning of @code{BREAK} is defined by the transport | |
8775bb90 MS |
36777 | mechanism and may, in fact, be undefined. @value{GDBN} does not |
36778 | currently define a @code{BREAK} mechanism for any of the network | |
36779 | interfaces except for TCP, in which case @value{GDBN} sends the | |
36780 | @code{telnet} BREAK sequence. | |
9a6253be KB |
36781 | |
36782 | @samp{Ctrl-C}, on the other hand, is defined and implemented for all | |
36783 | transport mechanisms. It is represented by sending the single byte | |
36784 | @code{0x03} without any of the usual packet overhead described in | |
36785 | the Overview section (@pxref{Overview}). When a @code{0x03} byte is | |
36786 | transmitted as part of a packet, it is considered to be packet data | |
36787 | and does @emph{not} represent an interrupt. E.g., an @samp{X} packet | |
0876f84a | 36788 | (@pxref{X packet}), used for binary downloads, may include an unescaped |
9a6253be KB |
36789 | @code{0x03} as part of its packet. |
36790 | ||
9a7071a8 JB |
36791 | @code{BREAK} followed by @code{g} is also known as Magic SysRq g. |
36792 | When Linux kernel receives this sequence from serial port, | |
36793 | it stops execution and connects to gdb. | |
36794 | ||
9a6253be KB |
36795 | Stubs are not required to recognize these interrupt mechanisms and the |
36796 | precise meaning associated with receipt of the interrupt is | |
8b23ecc4 SL |
36797 | implementation defined. If the target supports debugging of multiple |
36798 | threads and/or processes, it should attempt to interrupt all | |
36799 | currently-executing threads and processes. | |
36800 | If the stub is successful at interrupting the | |
36801 | running program, it should send one of the stop | |
36802 | reply packets (@pxref{Stop Reply Packets}) to @value{GDBN} as a result | |
36803 | of successfully stopping the program in all-stop mode, and a stop reply | |
36804 | for each stopped thread in non-stop mode. | |
36805 | Interrupts received while the | |
36806 | program is stopped are discarded. | |
36807 | ||
36808 | @node Notification Packets | |
36809 | @section Notification Packets | |
36810 | @cindex notification packets | |
36811 | @cindex packets, notification | |
36812 | ||
36813 | The @value{GDBN} remote serial protocol includes @dfn{notifications}, | |
36814 | packets that require no acknowledgment. Both the GDB and the stub | |
36815 | may send notifications (although the only notifications defined at | |
36816 | present are sent by the stub). Notifications carry information | |
36817 | without incurring the round-trip latency of an acknowledgment, and so | |
36818 | are useful for low-impact communications where occasional packet loss | |
36819 | is not a problem. | |
36820 | ||
36821 | A notification packet has the form @samp{% @var{data} # | |
36822 | @var{checksum}}, where @var{data} is the content of the notification, | |
36823 | and @var{checksum} is a checksum of @var{data}, computed and formatted | |
36824 | as for ordinary @value{GDBN} packets. A notification's @var{data} | |
36825 | never contains @samp{$}, @samp{%} or @samp{#} characters. Upon | |
36826 | receiving a notification, the recipient sends no @samp{+} or @samp{-} | |
36827 | to acknowledge the notification's receipt or to report its corruption. | |
36828 | ||
36829 | Every notification's @var{data} begins with a name, which contains no | |
36830 | colon characters, followed by a colon character. | |
36831 | ||
36832 | Recipients should silently ignore corrupted notifications and | |
36833 | notifications they do not understand. Recipients should restart | |
36834 | timeout periods on receipt of a well-formed notification, whether or | |
36835 | not they understand it. | |
36836 | ||
36837 | Senders should only send the notifications described here when this | |
36838 | protocol description specifies that they are permitted. In the | |
36839 | future, we may extend the protocol to permit existing notifications in | |
36840 | new contexts; this rule helps older senders avoid confusing newer | |
36841 | recipients. | |
36842 | ||
36843 | (Older versions of @value{GDBN} ignore bytes received until they see | |
36844 | the @samp{$} byte that begins an ordinary packet, so new stubs may | |
36845 | transmit notifications without fear of confusing older clients. There | |
36846 | are no notifications defined for @value{GDBN} to send at the moment, but we | |
36847 | assume that most older stubs would ignore them, as well.) | |
36848 | ||
8dbe8ece | 36849 | Each notification is comprised of three parts: |
8b23ecc4 | 36850 | @table @samp |
8dbe8ece YQ |
36851 | @item @var{name}:@var{event} |
36852 | The notification packet is sent by the side that initiates the | |
36853 | exchange (currently, only the stub does that), with @var{event} | |
697aa1b7 EZ |
36854 | carrying the specific information about the notification, and |
36855 | @var{name} specifying the name of the notification. | |
8dbe8ece YQ |
36856 | @item @var{ack} |
36857 | The acknowledge sent by the other side, usually @value{GDBN}, to | |
36858 | acknowledge the exchange and request the event. | |
36859 | @end table | |
36860 | ||
36861 | The purpose of an asynchronous notification mechanism is to report to | |
36862 | @value{GDBN} that something interesting happened in the remote stub. | |
36863 | ||
36864 | The remote stub may send notification @var{name}:@var{event} | |
36865 | at any time, but @value{GDBN} acknowledges the notification when | |
36866 | appropriate. The notification event is pending before @value{GDBN} | |
36867 | acknowledges. Only one notification at a time may be pending; if | |
36868 | additional events occur before @value{GDBN} has acknowledged the | |
36869 | previous notification, they must be queued by the stub for later | |
36870 | synchronous transmission in response to @var{ack} packets from | |
36871 | @value{GDBN}. Because the notification mechanism is unreliable, | |
36872 | the stub is permitted to resend a notification if it believes | |
36873 | @value{GDBN} may not have received it. | |
36874 | ||
36875 | Specifically, notifications may appear when @value{GDBN} is not | |
36876 | otherwise reading input from the stub, or when @value{GDBN} is | |
36877 | expecting to read a normal synchronous response or a | |
36878 | @samp{+}/@samp{-} acknowledgment to a packet it has sent. | |
36879 | Notification packets are distinct from any other communication from | |
36880 | the stub so there is no ambiguity. | |
36881 | ||
36882 | After receiving a notification, @value{GDBN} shall acknowledge it by | |
36883 | sending a @var{ack} packet as a regular, synchronous request to the | |
36884 | stub. Such acknowledgment is not required to happen immediately, as | |
36885 | @value{GDBN} is permitted to send other, unrelated packets to the | |
36886 | stub first, which the stub should process normally. | |
36887 | ||
36888 | Upon receiving a @var{ack} packet, if the stub has other queued | |
36889 | events to report to @value{GDBN}, it shall respond by sending a | |
36890 | normal @var{event}. @value{GDBN} shall then send another @var{ack} | |
36891 | packet to solicit further responses; again, it is permitted to send | |
36892 | other, unrelated packets as well which the stub should process | |
36893 | normally. | |
36894 | ||
36895 | If the stub receives a @var{ack} packet and there are no additional | |
36896 | @var{event} to report, the stub shall return an @samp{OK} response. | |
36897 | At this point, @value{GDBN} has finished processing a notification | |
36898 | and the stub has completed sending any queued events. @value{GDBN} | |
36899 | won't accept any new notifications until the final @samp{OK} is | |
36900 | received . If further notification events occur, the stub shall send | |
36901 | a new notification, @value{GDBN} shall accept the notification, and | |
36902 | the process shall be repeated. | |
36903 | ||
36904 | The process of asynchronous notification can be illustrated by the | |
36905 | following example: | |
36906 | @smallexample | |
36907 | <- @code{%%Stop:T0505:98e7ffbf;04:4ce6ffbf;08:b1b6e54c;thread:p7526.7526;core:0;} | |
36908 | @code{...} | |
36909 | -> @code{vStopped} | |
36910 | <- @code{T0505:68f37db7;04:40f37db7;08:63850408;thread:p7526.7528;core:0;} | |
36911 | -> @code{vStopped} | |
36912 | <- @code{T0505:68e3fdb6;04:40e3fdb6;08:63850408;thread:p7526.7529;core:0;} | |
36913 | -> @code{vStopped} | |
36914 | <- @code{OK} | |
36915 | @end smallexample | |
36916 | ||
36917 | The following notifications are defined: | |
36918 | @multitable @columnfractions 0.12 0.12 0.38 0.38 | |
36919 | ||
36920 | @item Notification | |
36921 | @tab Ack | |
36922 | @tab Event | |
36923 | @tab Description | |
36924 | ||
36925 | @item Stop | |
36926 | @tab vStopped | |
36927 | @tab @var{reply}. The @var{reply} has the form of a stop reply, as | |
8b23ecc4 SL |
36928 | described in @ref{Stop Reply Packets}. Refer to @ref{Remote Non-Stop}, |
36929 | for information on how these notifications are acknowledged by | |
36930 | @value{GDBN}. | |
8dbe8ece YQ |
36931 | @tab Report an asynchronous stop event in non-stop mode. |
36932 | ||
36933 | @end multitable | |
8b23ecc4 SL |
36934 | |
36935 | @node Remote Non-Stop | |
36936 | @section Remote Protocol Support for Non-Stop Mode | |
36937 | ||
36938 | @value{GDBN}'s remote protocol supports non-stop debugging of | |
36939 | multi-threaded programs, as described in @ref{Non-Stop Mode}. If the stub | |
36940 | supports non-stop mode, it should report that to @value{GDBN} by including | |
36941 | @samp{QNonStop+} in its @samp{qSupported} response (@pxref{qSupported}). | |
36942 | ||
36943 | @value{GDBN} typically sends a @samp{QNonStop} packet only when | |
36944 | establishing a new connection with the stub. Entering non-stop mode | |
36945 | does not alter the state of any currently-running threads, but targets | |
36946 | must stop all threads in any already-attached processes when entering | |
36947 | all-stop mode. @value{GDBN} uses the @samp{?} packet as necessary to | |
36948 | probe the target state after a mode change. | |
36949 | ||
36950 | In non-stop mode, when an attached process encounters an event that | |
36951 | would otherwise be reported with a stop reply, it uses the | |
36952 | asynchronous notification mechanism (@pxref{Notification Packets}) to | |
36953 | inform @value{GDBN}. In contrast to all-stop mode, where all threads | |
36954 | in all processes are stopped when a stop reply is sent, in non-stop | |
36955 | mode only the thread reporting the stop event is stopped. That is, | |
36956 | when reporting a @samp{S} or @samp{T} response to indicate completion | |
36957 | of a step operation, hitting a breakpoint, or a fault, only the | |
36958 | affected thread is stopped; any other still-running threads continue | |
36959 | to run. When reporting a @samp{W} or @samp{X} response, all running | |
36960 | threads belonging to other attached processes continue to run. | |
36961 | ||
8b23ecc4 SL |
36962 | In non-stop mode, the target shall respond to the @samp{?} packet as |
36963 | follows. First, any incomplete stop reply notification/@samp{vStopped} | |
36964 | sequence in progress is abandoned. The target must begin a new | |
36965 | sequence reporting stop events for all stopped threads, whether or not | |
36966 | it has previously reported those events to @value{GDBN}. The first | |
36967 | stop reply is sent as a synchronous reply to the @samp{?} packet, and | |
36968 | subsequent stop replies are sent as responses to @samp{vStopped} packets | |
36969 | using the mechanism described above. The target must not send | |
36970 | asynchronous stop reply notifications until the sequence is complete. | |
36971 | If all threads are running when the target receives the @samp{?} packet, | |
36972 | or if the target is not attached to any process, it shall respond | |
36973 | @samp{OK}. | |
9a6253be | 36974 | |
a6f3e723 SL |
36975 | @node Packet Acknowledgment |
36976 | @section Packet Acknowledgment | |
36977 | ||
36978 | @cindex acknowledgment, for @value{GDBN} remote | |
36979 | @cindex packet acknowledgment, for @value{GDBN} remote | |
36980 | By default, when either the host or the target machine receives a packet, | |
36981 | the first response expected is an acknowledgment: either @samp{+} (to indicate | |
36982 | the package was received correctly) or @samp{-} (to request retransmission). | |
36983 | This mechanism allows the @value{GDBN} remote protocol to operate over | |
36984 | unreliable transport mechanisms, such as a serial line. | |
36985 | ||
36986 | In cases where the transport mechanism is itself reliable (such as a pipe or | |
36987 | TCP connection), the @samp{+}/@samp{-} acknowledgments are redundant. | |
36988 | It may be desirable to disable them in that case to reduce communication | |
36989 | overhead, or for other reasons. This can be accomplished by means of the | |
36990 | @samp{QStartNoAckMode} packet; @pxref{QStartNoAckMode}. | |
36991 | ||
36992 | When in no-acknowledgment mode, neither the stub nor @value{GDBN} shall send or | |
36993 | expect @samp{+}/@samp{-} protocol acknowledgments. The packet | |
36994 | and response format still includes the normal checksum, as described in | |
36995 | @ref{Overview}, but the checksum may be ignored by the receiver. | |
36996 | ||
36997 | If the stub supports @samp{QStartNoAckMode} and prefers to operate in | |
36998 | no-acknowledgment mode, it should report that to @value{GDBN} | |
36999 | by including @samp{QStartNoAckMode+} in its response to @samp{qSupported}; | |
37000 | @pxref{qSupported}. | |
37001 | If @value{GDBN} also supports @samp{QStartNoAckMode} and it has not been | |
37002 | disabled via the @code{set remote noack-packet off} command | |
37003 | (@pxref{Remote Configuration}), | |
37004 | @value{GDBN} may then send a @samp{QStartNoAckMode} packet to the stub. | |
37005 | Only then may the stub actually turn off packet acknowledgments. | |
37006 | @value{GDBN} sends a final @samp{+} acknowledgment of the stub's @samp{OK} | |
37007 | response, which can be safely ignored by the stub. | |
37008 | ||
37009 | Note that @code{set remote noack-packet} command only affects negotiation | |
37010 | between @value{GDBN} and the stub when subsequent connections are made; | |
37011 | it does not affect the protocol acknowledgment state for any current | |
37012 | connection. | |
37013 | Since @samp{+}/@samp{-} acknowledgments are enabled by default when a | |
37014 | new connection is established, | |
37015 | there is also no protocol request to re-enable the acknowledgments | |
37016 | for the current connection, once disabled. | |
37017 | ||
ee2d5c50 AC |
37018 | @node Examples |
37019 | @section Examples | |
eb12ee30 | 37020 | |
8e04817f AC |
37021 | Example sequence of a target being re-started. Notice how the restart |
37022 | does not get any direct output: | |
eb12ee30 | 37023 | |
474c8240 | 37024 | @smallexample |
d2c6833e AC |
37025 | -> @code{R00} |
37026 | <- @code{+} | |
8e04817f | 37027 | @emph{target restarts} |
d2c6833e | 37028 | -> @code{?} |
8e04817f | 37029 | <- @code{+} |
d2c6833e AC |
37030 | <- @code{T001:1234123412341234} |
37031 | -> @code{+} | |
474c8240 | 37032 | @end smallexample |
eb12ee30 | 37033 | |
8e04817f | 37034 | Example sequence of a target being stepped by a single instruction: |
eb12ee30 | 37035 | |
474c8240 | 37036 | @smallexample |
d2c6833e | 37037 | -> @code{G1445@dots{}} |
8e04817f | 37038 | <- @code{+} |
d2c6833e AC |
37039 | -> @code{s} |
37040 | <- @code{+} | |
37041 | @emph{time passes} | |
37042 | <- @code{T001:1234123412341234} | |
8e04817f | 37043 | -> @code{+} |
d2c6833e | 37044 | -> @code{g} |
8e04817f | 37045 | <- @code{+} |
d2c6833e AC |
37046 | <- @code{1455@dots{}} |
37047 | -> @code{+} | |
474c8240 | 37048 | @end smallexample |
eb12ee30 | 37049 | |
79a6e687 BW |
37050 | @node File-I/O Remote Protocol Extension |
37051 | @section File-I/O Remote Protocol Extension | |
0ce1b118 CV |
37052 | @cindex File-I/O remote protocol extension |
37053 | ||
37054 | @menu | |
37055 | * File-I/O Overview:: | |
79a6e687 BW |
37056 | * Protocol Basics:: |
37057 | * The F Request Packet:: | |
37058 | * The F Reply Packet:: | |
37059 | * The Ctrl-C Message:: | |
0ce1b118 | 37060 | * Console I/O:: |
79a6e687 | 37061 | * List of Supported Calls:: |
db2e3e2e | 37062 | * Protocol-specific Representation of Datatypes:: |
0ce1b118 CV |
37063 | * Constants:: |
37064 | * File-I/O Examples:: | |
37065 | @end menu | |
37066 | ||
37067 | @node File-I/O Overview | |
37068 | @subsection File-I/O Overview | |
37069 | @cindex file-i/o overview | |
37070 | ||
9c16f35a | 37071 | The @dfn{File I/O remote protocol extension} (short: File-I/O) allows the |
fc320d37 | 37072 | target to use the host's file system and console I/O to perform various |
0ce1b118 | 37073 | system calls. System calls on the target system are translated into a |
fc320d37 SL |
37074 | remote protocol packet to the host system, which then performs the needed |
37075 | actions and returns a response packet to the target system. | |
0ce1b118 CV |
37076 | This simulates file system operations even on targets that lack file systems. |
37077 | ||
fc320d37 SL |
37078 | The protocol is defined to be independent of both the host and target systems. |
37079 | It uses its own internal representation of datatypes and values. Both | |
0ce1b118 | 37080 | @value{GDBN} and the target's @value{GDBN} stub are responsible for |
fc320d37 SL |
37081 | translating the system-dependent value representations into the internal |
37082 | protocol representations when data is transmitted. | |
0ce1b118 | 37083 | |
fc320d37 SL |
37084 | The communication is synchronous. A system call is possible only when |
37085 | @value{GDBN} is waiting for a response from the @samp{C}, @samp{c}, @samp{S} | |
37086 | or @samp{s} packets. While @value{GDBN} handles the request for a system call, | |
0ce1b118 | 37087 | the target is stopped to allow deterministic access to the target's |
fc320d37 SL |
37088 | memory. Therefore File-I/O is not interruptible by target signals. On |
37089 | the other hand, it is possible to interrupt File-I/O by a user interrupt | |
c8aa23ab | 37090 | (@samp{Ctrl-C}) within @value{GDBN}. |
0ce1b118 CV |
37091 | |
37092 | The target's request to perform a host system call does not finish | |
37093 | the latest @samp{C}, @samp{c}, @samp{S} or @samp{s} action. That means, | |
37094 | after finishing the system call, the target returns to continuing the | |
37095 | previous activity (continue, step). No additional continue or step | |
37096 | request from @value{GDBN} is required. | |
37097 | ||
37098 | @smallexample | |
f7dc1244 | 37099 | (@value{GDBP}) continue |
0ce1b118 CV |
37100 | <- target requests 'system call X' |
37101 | target is stopped, @value{GDBN} executes system call | |
3f94c067 BW |
37102 | -> @value{GDBN} returns result |
37103 | ... target continues, @value{GDBN} returns to wait for the target | |
0ce1b118 CV |
37104 | <- target hits breakpoint and sends a Txx packet |
37105 | @end smallexample | |
37106 | ||
fc320d37 SL |
37107 | The protocol only supports I/O on the console and to regular files on |
37108 | the host file system. Character or block special devices, pipes, | |
37109 | named pipes, sockets or any other communication method on the host | |
0ce1b118 CV |
37110 | system are not supported by this protocol. |
37111 | ||
8b23ecc4 SL |
37112 | File I/O is not supported in non-stop mode. |
37113 | ||
79a6e687 BW |
37114 | @node Protocol Basics |
37115 | @subsection Protocol Basics | |
0ce1b118 CV |
37116 | @cindex protocol basics, file-i/o |
37117 | ||
fc320d37 SL |
37118 | The File-I/O protocol uses the @code{F} packet as the request as well |
37119 | as reply packet. Since a File-I/O system call can only occur when | |
37120 | @value{GDBN} is waiting for a response from the continuing or stepping target, | |
37121 | the File-I/O request is a reply that @value{GDBN} has to expect as a result | |
37122 | of a previous @samp{C}, @samp{c}, @samp{S} or @samp{s} packet. | |
0ce1b118 CV |
37123 | This @code{F} packet contains all information needed to allow @value{GDBN} |
37124 | to call the appropriate host system call: | |
37125 | ||
37126 | @itemize @bullet | |
b383017d | 37127 | @item |
0ce1b118 CV |
37128 | A unique identifier for the requested system call. |
37129 | ||
37130 | @item | |
37131 | All parameters to the system call. Pointers are given as addresses | |
37132 | in the target memory address space. Pointers to strings are given as | |
b383017d | 37133 | pointer/length pair. Numerical values are given as they are. |
db2e3e2e | 37134 | Numerical control flags are given in a protocol-specific representation. |
0ce1b118 CV |
37135 | |
37136 | @end itemize | |
37137 | ||
fc320d37 | 37138 | At this point, @value{GDBN} has to perform the following actions. |
0ce1b118 CV |
37139 | |
37140 | @itemize @bullet | |
b383017d | 37141 | @item |
fc320d37 SL |
37142 | If the parameters include pointer values to data needed as input to a |
37143 | system call, @value{GDBN} requests this data from the target with a | |
0ce1b118 CV |
37144 | standard @code{m} packet request. This additional communication has to be |
37145 | expected by the target implementation and is handled as any other @code{m} | |
37146 | packet. | |
37147 | ||
37148 | @item | |
37149 | @value{GDBN} translates all value from protocol representation to host | |
37150 | representation as needed. Datatypes are coerced into the host types. | |
37151 | ||
37152 | @item | |
fc320d37 | 37153 | @value{GDBN} calls the system call. |
0ce1b118 CV |
37154 | |
37155 | @item | |
37156 | It then coerces datatypes back to protocol representation. | |
37157 | ||
37158 | @item | |
fc320d37 SL |
37159 | If the system call is expected to return data in buffer space specified |
37160 | by pointer parameters to the call, the data is transmitted to the | |
0ce1b118 CV |
37161 | target using a @code{M} or @code{X} packet. This packet has to be expected |
37162 | by the target implementation and is handled as any other @code{M} or @code{X} | |
37163 | packet. | |
37164 | ||
37165 | @end itemize | |
37166 | ||
37167 | Eventually @value{GDBN} replies with another @code{F} packet which contains all | |
37168 | necessary information for the target to continue. This at least contains | |
37169 | ||
37170 | @itemize @bullet | |
37171 | @item | |
37172 | Return value. | |
37173 | ||
37174 | @item | |
37175 | @code{errno}, if has been changed by the system call. | |
37176 | ||
37177 | @item | |
37178 | ``Ctrl-C'' flag. | |
37179 | ||
37180 | @end itemize | |
37181 | ||
37182 | After having done the needed type and value coercion, the target continues | |
37183 | the latest continue or step action. | |
37184 | ||
79a6e687 BW |
37185 | @node The F Request Packet |
37186 | @subsection The @code{F} Request Packet | |
0ce1b118 CV |
37187 | @cindex file-i/o request packet |
37188 | @cindex @code{F} request packet | |
37189 | ||
37190 | The @code{F} request packet has the following format: | |
37191 | ||
37192 | @table @samp | |
fc320d37 | 37193 | @item F@var{call-id},@var{parameter@dots{}} |
0ce1b118 CV |
37194 | |
37195 | @var{call-id} is the identifier to indicate the host system call to be called. | |
37196 | This is just the name of the function. | |
37197 | ||
fc320d37 SL |
37198 | @var{parameter@dots{}} are the parameters to the system call. |
37199 | Parameters are hexadecimal integer values, either the actual values in case | |
37200 | of scalar datatypes, pointers to target buffer space in case of compound | |
37201 | datatypes and unspecified memory areas, or pointer/length pairs in case | |
37202 | of string parameters. These are appended to the @var{call-id} as a | |
37203 | comma-delimited list. All values are transmitted in ASCII | |
37204 | string representation, pointer/length pairs separated by a slash. | |
0ce1b118 | 37205 | |
b383017d | 37206 | @end table |
0ce1b118 | 37207 | |
fc320d37 | 37208 | |
0ce1b118 | 37209 | |
79a6e687 BW |
37210 | @node The F Reply Packet |
37211 | @subsection The @code{F} Reply Packet | |
0ce1b118 CV |
37212 | @cindex file-i/o reply packet |
37213 | @cindex @code{F} reply packet | |
37214 | ||
37215 | The @code{F} reply packet has the following format: | |
37216 | ||
37217 | @table @samp | |
37218 | ||
d3bdde98 | 37219 | @item F@var{retcode},@var{errno},@var{Ctrl-C flag};@var{call-specific attachment} |
0ce1b118 CV |
37220 | |
37221 | @var{retcode} is the return code of the system call as hexadecimal value. | |
37222 | ||
db2e3e2e BW |
37223 | @var{errno} is the @code{errno} set by the call, in protocol-specific |
37224 | representation. | |
0ce1b118 CV |
37225 | This parameter can be omitted if the call was successful. |
37226 | ||
fc320d37 SL |
37227 | @var{Ctrl-C flag} is only sent if the user requested a break. In this |
37228 | case, @var{errno} must be sent as well, even if the call was successful. | |
37229 | The @var{Ctrl-C flag} itself consists of the character @samp{C}: | |
0ce1b118 CV |
37230 | |
37231 | @smallexample | |
37232 | F0,0,C | |
37233 | @end smallexample | |
37234 | ||
37235 | @noindent | |
fc320d37 | 37236 | or, if the call was interrupted before the host call has been performed: |
0ce1b118 CV |
37237 | |
37238 | @smallexample | |
37239 | F-1,4,C | |
37240 | @end smallexample | |
37241 | ||
37242 | @noindent | |
db2e3e2e | 37243 | assuming 4 is the protocol-specific representation of @code{EINTR}. |
0ce1b118 CV |
37244 | |
37245 | @end table | |
37246 | ||
0ce1b118 | 37247 | |
79a6e687 BW |
37248 | @node The Ctrl-C Message |
37249 | @subsection The @samp{Ctrl-C} Message | |
0ce1b118 CV |
37250 | @cindex ctrl-c message, in file-i/o protocol |
37251 | ||
c8aa23ab | 37252 | If the @samp{Ctrl-C} flag is set in the @value{GDBN} |
79a6e687 | 37253 | reply packet (@pxref{The F Reply Packet}), |
fc320d37 | 37254 | the target should behave as if it had |
0ce1b118 | 37255 | gotten a break message. The meaning for the target is ``system call |
fc320d37 | 37256 | interrupted by @code{SIGINT}''. Consequentially, the target should actually stop |
0ce1b118 | 37257 | (as with a break message) and return to @value{GDBN} with a @code{T02} |
c8aa23ab | 37258 | packet. |
fc320d37 SL |
37259 | |
37260 | It's important for the target to know in which | |
37261 | state the system call was interrupted. There are two possible cases: | |
0ce1b118 CV |
37262 | |
37263 | @itemize @bullet | |
37264 | @item | |
37265 | The system call hasn't been performed on the host yet. | |
37266 | ||
37267 | @item | |
37268 | The system call on the host has been finished. | |
37269 | ||
37270 | @end itemize | |
37271 | ||
37272 | These two states can be distinguished by the target by the value of the | |
37273 | returned @code{errno}. If it's the protocol representation of @code{EINTR}, the system | |
37274 | call hasn't been performed. This is equivalent to the @code{EINTR} handling | |
37275 | on POSIX systems. In any other case, the target may presume that the | |
fc320d37 | 37276 | system call has been finished --- successfully or not --- and should behave |
0ce1b118 CV |
37277 | as if the break message arrived right after the system call. |
37278 | ||
fc320d37 | 37279 | @value{GDBN} must behave reliably. If the system call has not been called |
0ce1b118 CV |
37280 | yet, @value{GDBN} may send the @code{F} reply immediately, setting @code{EINTR} as |
37281 | @code{errno} in the packet. If the system call on the host has been finished | |
fc320d37 SL |
37282 | before the user requests a break, the full action must be finished by |
37283 | @value{GDBN}. This requires sending @code{M} or @code{X} packets as necessary. | |
37284 | The @code{F} packet may only be sent when either nothing has happened | |
0ce1b118 CV |
37285 | or the full action has been completed. |
37286 | ||
37287 | @node Console I/O | |
37288 | @subsection Console I/O | |
37289 | @cindex console i/o as part of file-i/o | |
37290 | ||
d3e8051b | 37291 | By default and if not explicitly closed by the target system, the file |
0ce1b118 CV |
37292 | descriptors 0, 1 and 2 are connected to the @value{GDBN} console. Output |
37293 | on the @value{GDBN} console is handled as any other file output operation | |
37294 | (@code{write(1, @dots{})} or @code{write(2, @dots{})}). Console input is handled | |
37295 | by @value{GDBN} so that after the target read request from file descriptor | |
37296 | 0 all following typing is buffered until either one of the following | |
37297 | conditions is met: | |
37298 | ||
37299 | @itemize @bullet | |
37300 | @item | |
c8aa23ab | 37301 | The user types @kbd{Ctrl-c}. The behaviour is as explained above, and the |
0ce1b118 CV |
37302 | @code{read} |
37303 | system call is treated as finished. | |
37304 | ||
37305 | @item | |
7f9087cb | 37306 | The user presses @key{RET}. This is treated as end of input with a trailing |
fc320d37 | 37307 | newline. |
0ce1b118 CV |
37308 | |
37309 | @item | |
c8aa23ab EZ |
37310 | The user types @kbd{Ctrl-d}. This is treated as end of input. No trailing |
37311 | character (neither newline nor @samp{Ctrl-D}) is appended to the input. | |
0ce1b118 CV |
37312 | |
37313 | @end itemize | |
37314 | ||
fc320d37 SL |
37315 | If the user has typed more characters than fit in the buffer given to |
37316 | the @code{read} call, the trailing characters are buffered in @value{GDBN} until | |
37317 | either another @code{read(0, @dots{})} is requested by the target, or debugging | |
37318 | is stopped at the user's request. | |
0ce1b118 | 37319 | |
0ce1b118 | 37320 | |
79a6e687 BW |
37321 | @node List of Supported Calls |
37322 | @subsection List of Supported Calls | |
0ce1b118 CV |
37323 | @cindex list of supported file-i/o calls |
37324 | ||
37325 | @menu | |
37326 | * open:: | |
37327 | * close:: | |
37328 | * read:: | |
37329 | * write:: | |
37330 | * lseek:: | |
37331 | * rename:: | |
37332 | * unlink:: | |
37333 | * stat/fstat:: | |
37334 | * gettimeofday:: | |
37335 | * isatty:: | |
37336 | * system:: | |
37337 | @end menu | |
37338 | ||
37339 | @node open | |
37340 | @unnumberedsubsubsec open | |
37341 | @cindex open, file-i/o system call | |
37342 | ||
fc320d37 SL |
37343 | @table @asis |
37344 | @item Synopsis: | |
0ce1b118 | 37345 | @smallexample |
0ce1b118 CV |
37346 | int open(const char *pathname, int flags); |
37347 | int open(const char *pathname, int flags, mode_t mode); | |
0ce1b118 CV |
37348 | @end smallexample |
37349 | ||
fc320d37 SL |
37350 | @item Request: |
37351 | @samp{Fopen,@var{pathptr}/@var{len},@var{flags},@var{mode}} | |
37352 | ||
0ce1b118 | 37353 | @noindent |
fc320d37 | 37354 | @var{flags} is the bitwise @code{OR} of the following values: |
0ce1b118 CV |
37355 | |
37356 | @table @code | |
b383017d | 37357 | @item O_CREAT |
0ce1b118 CV |
37358 | If the file does not exist it will be created. The host |
37359 | rules apply as far as file ownership and time stamps | |
37360 | are concerned. | |
37361 | ||
b383017d | 37362 | @item O_EXCL |
fc320d37 | 37363 | When used with @code{O_CREAT}, if the file already exists it is |
0ce1b118 CV |
37364 | an error and open() fails. |
37365 | ||
b383017d | 37366 | @item O_TRUNC |
0ce1b118 | 37367 | If the file already exists and the open mode allows |
fc320d37 SL |
37368 | writing (@code{O_RDWR} or @code{O_WRONLY} is given) it will be |
37369 | truncated to zero length. | |
0ce1b118 | 37370 | |
b383017d | 37371 | @item O_APPEND |
0ce1b118 CV |
37372 | The file is opened in append mode. |
37373 | ||
b383017d | 37374 | @item O_RDONLY |
0ce1b118 CV |
37375 | The file is opened for reading only. |
37376 | ||
b383017d | 37377 | @item O_WRONLY |
0ce1b118 CV |
37378 | The file is opened for writing only. |
37379 | ||
b383017d | 37380 | @item O_RDWR |
0ce1b118 | 37381 | The file is opened for reading and writing. |
fc320d37 | 37382 | @end table |
0ce1b118 CV |
37383 | |
37384 | @noindent | |
fc320d37 | 37385 | Other bits are silently ignored. |
0ce1b118 | 37386 | |
0ce1b118 CV |
37387 | |
37388 | @noindent | |
fc320d37 | 37389 | @var{mode} is the bitwise @code{OR} of the following values: |
0ce1b118 CV |
37390 | |
37391 | @table @code | |
b383017d | 37392 | @item S_IRUSR |
0ce1b118 CV |
37393 | User has read permission. |
37394 | ||
b383017d | 37395 | @item S_IWUSR |
0ce1b118 CV |
37396 | User has write permission. |
37397 | ||
b383017d | 37398 | @item S_IRGRP |
0ce1b118 CV |
37399 | Group has read permission. |
37400 | ||
b383017d | 37401 | @item S_IWGRP |
0ce1b118 CV |
37402 | Group has write permission. |
37403 | ||
b383017d | 37404 | @item S_IROTH |
0ce1b118 CV |
37405 | Others have read permission. |
37406 | ||
b383017d | 37407 | @item S_IWOTH |
0ce1b118 | 37408 | Others have write permission. |
fc320d37 | 37409 | @end table |
0ce1b118 CV |
37410 | |
37411 | @noindent | |
fc320d37 | 37412 | Other bits are silently ignored. |
0ce1b118 | 37413 | |
0ce1b118 | 37414 | |
fc320d37 SL |
37415 | @item Return value: |
37416 | @code{open} returns the new file descriptor or -1 if an error | |
37417 | occurred. | |
0ce1b118 | 37418 | |
fc320d37 | 37419 | @item Errors: |
0ce1b118 CV |
37420 | |
37421 | @table @code | |
b383017d | 37422 | @item EEXIST |
fc320d37 | 37423 | @var{pathname} already exists and @code{O_CREAT} and @code{O_EXCL} were used. |
0ce1b118 | 37424 | |
b383017d | 37425 | @item EISDIR |
fc320d37 | 37426 | @var{pathname} refers to a directory. |
0ce1b118 | 37427 | |
b383017d | 37428 | @item EACCES |
0ce1b118 CV |
37429 | The requested access is not allowed. |
37430 | ||
37431 | @item ENAMETOOLONG | |
fc320d37 | 37432 | @var{pathname} was too long. |
0ce1b118 | 37433 | |
b383017d | 37434 | @item ENOENT |
fc320d37 | 37435 | A directory component in @var{pathname} does not exist. |
0ce1b118 | 37436 | |
b383017d | 37437 | @item ENODEV |
fc320d37 | 37438 | @var{pathname} refers to a device, pipe, named pipe or socket. |
0ce1b118 | 37439 | |
b383017d | 37440 | @item EROFS |
fc320d37 | 37441 | @var{pathname} refers to a file on a read-only filesystem and |
0ce1b118 CV |
37442 | write access was requested. |
37443 | ||
b383017d | 37444 | @item EFAULT |
fc320d37 | 37445 | @var{pathname} is an invalid pointer value. |
0ce1b118 | 37446 | |
b383017d | 37447 | @item ENOSPC |
0ce1b118 CV |
37448 | No space on device to create the file. |
37449 | ||
b383017d | 37450 | @item EMFILE |
0ce1b118 CV |
37451 | The process already has the maximum number of files open. |
37452 | ||
b383017d | 37453 | @item ENFILE |
0ce1b118 CV |
37454 | The limit on the total number of files open on the system |
37455 | has been reached. | |
37456 | ||
b383017d | 37457 | @item EINTR |
0ce1b118 CV |
37458 | The call was interrupted by the user. |
37459 | @end table | |
37460 | ||
fc320d37 SL |
37461 | @end table |
37462 | ||
0ce1b118 CV |
37463 | @node close |
37464 | @unnumberedsubsubsec close | |
37465 | @cindex close, file-i/o system call | |
37466 | ||
fc320d37 SL |
37467 | @table @asis |
37468 | @item Synopsis: | |
0ce1b118 | 37469 | @smallexample |
0ce1b118 | 37470 | int close(int fd); |
fc320d37 | 37471 | @end smallexample |
0ce1b118 | 37472 | |
fc320d37 SL |
37473 | @item Request: |
37474 | @samp{Fclose,@var{fd}} | |
0ce1b118 | 37475 | |
fc320d37 SL |
37476 | @item Return value: |
37477 | @code{close} returns zero on success, or -1 if an error occurred. | |
0ce1b118 | 37478 | |
fc320d37 | 37479 | @item Errors: |
0ce1b118 CV |
37480 | |
37481 | @table @code | |
b383017d | 37482 | @item EBADF |
fc320d37 | 37483 | @var{fd} isn't a valid open file descriptor. |
0ce1b118 | 37484 | |
b383017d | 37485 | @item EINTR |
0ce1b118 CV |
37486 | The call was interrupted by the user. |
37487 | @end table | |
37488 | ||
fc320d37 SL |
37489 | @end table |
37490 | ||
0ce1b118 CV |
37491 | @node read |
37492 | @unnumberedsubsubsec read | |
37493 | @cindex read, file-i/o system call | |
37494 | ||
fc320d37 SL |
37495 | @table @asis |
37496 | @item Synopsis: | |
0ce1b118 | 37497 | @smallexample |
0ce1b118 | 37498 | int read(int fd, void *buf, unsigned int count); |
fc320d37 | 37499 | @end smallexample |
0ce1b118 | 37500 | |
fc320d37 SL |
37501 | @item Request: |
37502 | @samp{Fread,@var{fd},@var{bufptr},@var{count}} | |
0ce1b118 | 37503 | |
fc320d37 | 37504 | @item Return value: |
0ce1b118 CV |
37505 | On success, the number of bytes read is returned. |
37506 | Zero indicates end of file. If count is zero, read | |
b383017d | 37507 | returns zero as well. On error, -1 is returned. |
0ce1b118 | 37508 | |
fc320d37 | 37509 | @item Errors: |
0ce1b118 CV |
37510 | |
37511 | @table @code | |
b383017d | 37512 | @item EBADF |
fc320d37 | 37513 | @var{fd} is not a valid file descriptor or is not open for |
0ce1b118 CV |
37514 | reading. |
37515 | ||
b383017d | 37516 | @item EFAULT |
fc320d37 | 37517 | @var{bufptr} is an invalid pointer value. |
0ce1b118 | 37518 | |
b383017d | 37519 | @item EINTR |
0ce1b118 CV |
37520 | The call was interrupted by the user. |
37521 | @end table | |
37522 | ||
fc320d37 SL |
37523 | @end table |
37524 | ||
0ce1b118 CV |
37525 | @node write |
37526 | @unnumberedsubsubsec write | |
37527 | @cindex write, file-i/o system call | |
37528 | ||
fc320d37 SL |
37529 | @table @asis |
37530 | @item Synopsis: | |
0ce1b118 | 37531 | @smallexample |
0ce1b118 | 37532 | int write(int fd, const void *buf, unsigned int count); |
fc320d37 | 37533 | @end smallexample |
0ce1b118 | 37534 | |
fc320d37 SL |
37535 | @item Request: |
37536 | @samp{Fwrite,@var{fd},@var{bufptr},@var{count}} | |
0ce1b118 | 37537 | |
fc320d37 | 37538 | @item Return value: |
0ce1b118 CV |
37539 | On success, the number of bytes written are returned. |
37540 | Zero indicates nothing was written. On error, -1 | |
37541 | is returned. | |
37542 | ||
fc320d37 | 37543 | @item Errors: |
0ce1b118 CV |
37544 | |
37545 | @table @code | |
b383017d | 37546 | @item EBADF |
fc320d37 | 37547 | @var{fd} is not a valid file descriptor or is not open for |
0ce1b118 CV |
37548 | writing. |
37549 | ||
b383017d | 37550 | @item EFAULT |
fc320d37 | 37551 | @var{bufptr} is an invalid pointer value. |
0ce1b118 | 37552 | |
b383017d | 37553 | @item EFBIG |
0ce1b118 | 37554 | An attempt was made to write a file that exceeds the |
db2e3e2e | 37555 | host-specific maximum file size allowed. |
0ce1b118 | 37556 | |
b383017d | 37557 | @item ENOSPC |
0ce1b118 CV |
37558 | No space on device to write the data. |
37559 | ||
b383017d | 37560 | @item EINTR |
0ce1b118 CV |
37561 | The call was interrupted by the user. |
37562 | @end table | |
37563 | ||
fc320d37 SL |
37564 | @end table |
37565 | ||
0ce1b118 CV |
37566 | @node lseek |
37567 | @unnumberedsubsubsec lseek | |
37568 | @cindex lseek, file-i/o system call | |
37569 | ||
fc320d37 SL |
37570 | @table @asis |
37571 | @item Synopsis: | |
0ce1b118 | 37572 | @smallexample |
0ce1b118 | 37573 | long lseek (int fd, long offset, int flag); |
0ce1b118 CV |
37574 | @end smallexample |
37575 | ||
fc320d37 SL |
37576 | @item Request: |
37577 | @samp{Flseek,@var{fd},@var{offset},@var{flag}} | |
37578 | ||
37579 | @var{flag} is one of: | |
0ce1b118 CV |
37580 | |
37581 | @table @code | |
b383017d | 37582 | @item SEEK_SET |
fc320d37 | 37583 | The offset is set to @var{offset} bytes. |
0ce1b118 | 37584 | |
b383017d | 37585 | @item SEEK_CUR |
fc320d37 | 37586 | The offset is set to its current location plus @var{offset} |
0ce1b118 CV |
37587 | bytes. |
37588 | ||
b383017d | 37589 | @item SEEK_END |
fc320d37 | 37590 | The offset is set to the size of the file plus @var{offset} |
0ce1b118 CV |
37591 | bytes. |
37592 | @end table | |
37593 | ||
fc320d37 | 37594 | @item Return value: |
0ce1b118 CV |
37595 | On success, the resulting unsigned offset in bytes from |
37596 | the beginning of the file is returned. Otherwise, a | |
37597 | value of -1 is returned. | |
37598 | ||
fc320d37 | 37599 | @item Errors: |
0ce1b118 CV |
37600 | |
37601 | @table @code | |
b383017d | 37602 | @item EBADF |
fc320d37 | 37603 | @var{fd} is not a valid open file descriptor. |
0ce1b118 | 37604 | |
b383017d | 37605 | @item ESPIPE |
fc320d37 | 37606 | @var{fd} is associated with the @value{GDBN} console. |
0ce1b118 | 37607 | |
b383017d | 37608 | @item EINVAL |
fc320d37 | 37609 | @var{flag} is not a proper value. |
0ce1b118 | 37610 | |
b383017d | 37611 | @item EINTR |
0ce1b118 CV |
37612 | The call was interrupted by the user. |
37613 | @end table | |
37614 | ||
fc320d37 SL |
37615 | @end table |
37616 | ||
0ce1b118 CV |
37617 | @node rename |
37618 | @unnumberedsubsubsec rename | |
37619 | @cindex rename, file-i/o system call | |
37620 | ||
fc320d37 SL |
37621 | @table @asis |
37622 | @item Synopsis: | |
0ce1b118 | 37623 | @smallexample |
0ce1b118 | 37624 | int rename(const char *oldpath, const char *newpath); |
fc320d37 | 37625 | @end smallexample |
0ce1b118 | 37626 | |
fc320d37 SL |
37627 | @item Request: |
37628 | @samp{Frename,@var{oldpathptr}/@var{len},@var{newpathptr}/@var{len}} | |
0ce1b118 | 37629 | |
fc320d37 | 37630 | @item Return value: |
0ce1b118 CV |
37631 | On success, zero is returned. On error, -1 is returned. |
37632 | ||
fc320d37 | 37633 | @item Errors: |
0ce1b118 CV |
37634 | |
37635 | @table @code | |
b383017d | 37636 | @item EISDIR |
fc320d37 | 37637 | @var{newpath} is an existing directory, but @var{oldpath} is not a |
0ce1b118 CV |
37638 | directory. |
37639 | ||
b383017d | 37640 | @item EEXIST |
fc320d37 | 37641 | @var{newpath} is a non-empty directory. |
0ce1b118 | 37642 | |
b383017d | 37643 | @item EBUSY |
fc320d37 | 37644 | @var{oldpath} or @var{newpath} is a directory that is in use by some |
0ce1b118 CV |
37645 | process. |
37646 | ||
b383017d | 37647 | @item EINVAL |
0ce1b118 CV |
37648 | An attempt was made to make a directory a subdirectory |
37649 | of itself. | |
37650 | ||
b383017d | 37651 | @item ENOTDIR |
fc320d37 SL |
37652 | A component used as a directory in @var{oldpath} or new |
37653 | path is not a directory. Or @var{oldpath} is a directory | |
37654 | and @var{newpath} exists but is not a directory. | |
0ce1b118 | 37655 | |
b383017d | 37656 | @item EFAULT |
fc320d37 | 37657 | @var{oldpathptr} or @var{newpathptr} are invalid pointer values. |
0ce1b118 | 37658 | |
b383017d | 37659 | @item EACCES |
0ce1b118 CV |
37660 | No access to the file or the path of the file. |
37661 | ||
37662 | @item ENAMETOOLONG | |
b383017d | 37663 | |
fc320d37 | 37664 | @var{oldpath} or @var{newpath} was too long. |
0ce1b118 | 37665 | |
b383017d | 37666 | @item ENOENT |
fc320d37 | 37667 | A directory component in @var{oldpath} or @var{newpath} does not exist. |
0ce1b118 | 37668 | |
b383017d | 37669 | @item EROFS |
0ce1b118 CV |
37670 | The file is on a read-only filesystem. |
37671 | ||
b383017d | 37672 | @item ENOSPC |
0ce1b118 CV |
37673 | The device containing the file has no room for the new |
37674 | directory entry. | |
37675 | ||
b383017d | 37676 | @item EINTR |
0ce1b118 CV |
37677 | The call was interrupted by the user. |
37678 | @end table | |
37679 | ||
fc320d37 SL |
37680 | @end table |
37681 | ||
0ce1b118 CV |
37682 | @node unlink |
37683 | @unnumberedsubsubsec unlink | |
37684 | @cindex unlink, file-i/o system call | |
37685 | ||
fc320d37 SL |
37686 | @table @asis |
37687 | @item Synopsis: | |
0ce1b118 | 37688 | @smallexample |
0ce1b118 | 37689 | int unlink(const char *pathname); |
fc320d37 | 37690 | @end smallexample |
0ce1b118 | 37691 | |
fc320d37 SL |
37692 | @item Request: |
37693 | @samp{Funlink,@var{pathnameptr}/@var{len}} | |
0ce1b118 | 37694 | |
fc320d37 | 37695 | @item Return value: |
0ce1b118 CV |
37696 | On success, zero is returned. On error, -1 is returned. |
37697 | ||
fc320d37 | 37698 | @item Errors: |
0ce1b118 CV |
37699 | |
37700 | @table @code | |
b383017d | 37701 | @item EACCES |
0ce1b118 CV |
37702 | No access to the file or the path of the file. |
37703 | ||
b383017d | 37704 | @item EPERM |
0ce1b118 CV |
37705 | The system does not allow unlinking of directories. |
37706 | ||
b383017d | 37707 | @item EBUSY |
fc320d37 | 37708 | The file @var{pathname} cannot be unlinked because it's |
0ce1b118 CV |
37709 | being used by another process. |
37710 | ||
b383017d | 37711 | @item EFAULT |
fc320d37 | 37712 | @var{pathnameptr} is an invalid pointer value. |
0ce1b118 CV |
37713 | |
37714 | @item ENAMETOOLONG | |
fc320d37 | 37715 | @var{pathname} was too long. |
0ce1b118 | 37716 | |
b383017d | 37717 | @item ENOENT |
fc320d37 | 37718 | A directory component in @var{pathname} does not exist. |
0ce1b118 | 37719 | |
b383017d | 37720 | @item ENOTDIR |
0ce1b118 CV |
37721 | A component of the path is not a directory. |
37722 | ||
b383017d | 37723 | @item EROFS |
0ce1b118 CV |
37724 | The file is on a read-only filesystem. |
37725 | ||
b383017d | 37726 | @item EINTR |
0ce1b118 CV |
37727 | The call was interrupted by the user. |
37728 | @end table | |
37729 | ||
fc320d37 SL |
37730 | @end table |
37731 | ||
0ce1b118 CV |
37732 | @node stat/fstat |
37733 | @unnumberedsubsubsec stat/fstat | |
37734 | @cindex fstat, file-i/o system call | |
37735 | @cindex stat, file-i/o system call | |
37736 | ||
fc320d37 SL |
37737 | @table @asis |
37738 | @item Synopsis: | |
0ce1b118 | 37739 | @smallexample |
0ce1b118 CV |
37740 | int stat(const char *pathname, struct stat *buf); |
37741 | int fstat(int fd, struct stat *buf); | |
fc320d37 | 37742 | @end smallexample |
0ce1b118 | 37743 | |
fc320d37 SL |
37744 | @item Request: |
37745 | @samp{Fstat,@var{pathnameptr}/@var{len},@var{bufptr}}@* | |
37746 | @samp{Ffstat,@var{fd},@var{bufptr}} | |
0ce1b118 | 37747 | |
fc320d37 | 37748 | @item Return value: |
0ce1b118 CV |
37749 | On success, zero is returned. On error, -1 is returned. |
37750 | ||
fc320d37 | 37751 | @item Errors: |
0ce1b118 CV |
37752 | |
37753 | @table @code | |
b383017d | 37754 | @item EBADF |
fc320d37 | 37755 | @var{fd} is not a valid open file. |
0ce1b118 | 37756 | |
b383017d | 37757 | @item ENOENT |
fc320d37 | 37758 | A directory component in @var{pathname} does not exist or the |
0ce1b118 CV |
37759 | path is an empty string. |
37760 | ||
b383017d | 37761 | @item ENOTDIR |
0ce1b118 CV |
37762 | A component of the path is not a directory. |
37763 | ||
b383017d | 37764 | @item EFAULT |
fc320d37 | 37765 | @var{pathnameptr} is an invalid pointer value. |
0ce1b118 | 37766 | |
b383017d | 37767 | @item EACCES |
0ce1b118 CV |
37768 | No access to the file or the path of the file. |
37769 | ||
37770 | @item ENAMETOOLONG | |
fc320d37 | 37771 | @var{pathname} was too long. |
0ce1b118 | 37772 | |
b383017d | 37773 | @item EINTR |
0ce1b118 CV |
37774 | The call was interrupted by the user. |
37775 | @end table | |
37776 | ||
fc320d37 SL |
37777 | @end table |
37778 | ||
0ce1b118 CV |
37779 | @node gettimeofday |
37780 | @unnumberedsubsubsec gettimeofday | |
37781 | @cindex gettimeofday, file-i/o system call | |
37782 | ||
fc320d37 SL |
37783 | @table @asis |
37784 | @item Synopsis: | |
0ce1b118 | 37785 | @smallexample |
0ce1b118 | 37786 | int gettimeofday(struct timeval *tv, void *tz); |
fc320d37 | 37787 | @end smallexample |
0ce1b118 | 37788 | |
fc320d37 SL |
37789 | @item Request: |
37790 | @samp{Fgettimeofday,@var{tvptr},@var{tzptr}} | |
0ce1b118 | 37791 | |
fc320d37 | 37792 | @item Return value: |
0ce1b118 CV |
37793 | On success, 0 is returned, -1 otherwise. |
37794 | ||
fc320d37 | 37795 | @item Errors: |
0ce1b118 CV |
37796 | |
37797 | @table @code | |
b383017d | 37798 | @item EINVAL |
fc320d37 | 37799 | @var{tz} is a non-NULL pointer. |
0ce1b118 | 37800 | |
b383017d | 37801 | @item EFAULT |
fc320d37 SL |
37802 | @var{tvptr} and/or @var{tzptr} is an invalid pointer value. |
37803 | @end table | |
37804 | ||
0ce1b118 CV |
37805 | @end table |
37806 | ||
37807 | @node isatty | |
37808 | @unnumberedsubsubsec isatty | |
37809 | @cindex isatty, file-i/o system call | |
37810 | ||
fc320d37 SL |
37811 | @table @asis |
37812 | @item Synopsis: | |
0ce1b118 | 37813 | @smallexample |
0ce1b118 | 37814 | int isatty(int fd); |
fc320d37 | 37815 | @end smallexample |
0ce1b118 | 37816 | |
fc320d37 SL |
37817 | @item Request: |
37818 | @samp{Fisatty,@var{fd}} | |
0ce1b118 | 37819 | |
fc320d37 SL |
37820 | @item Return value: |
37821 | Returns 1 if @var{fd} refers to the @value{GDBN} console, 0 otherwise. | |
0ce1b118 | 37822 | |
fc320d37 | 37823 | @item Errors: |
0ce1b118 CV |
37824 | |
37825 | @table @code | |
b383017d | 37826 | @item EINTR |
0ce1b118 CV |
37827 | The call was interrupted by the user. |
37828 | @end table | |
37829 | ||
fc320d37 SL |
37830 | @end table |
37831 | ||
37832 | Note that the @code{isatty} call is treated as a special case: it returns | |
37833 | 1 to the target if the file descriptor is attached | |
37834 | to the @value{GDBN} console, 0 otherwise. Implementing through system calls | |
37835 | would require implementing @code{ioctl} and would be more complex than | |
37836 | needed. | |
37837 | ||
37838 | ||
0ce1b118 CV |
37839 | @node system |
37840 | @unnumberedsubsubsec system | |
37841 | @cindex system, file-i/o system call | |
37842 | ||
fc320d37 SL |
37843 | @table @asis |
37844 | @item Synopsis: | |
0ce1b118 | 37845 | @smallexample |
0ce1b118 | 37846 | int system(const char *command); |
fc320d37 | 37847 | @end smallexample |
0ce1b118 | 37848 | |
fc320d37 SL |
37849 | @item Request: |
37850 | @samp{Fsystem,@var{commandptr}/@var{len}} | |
0ce1b118 | 37851 | |
fc320d37 | 37852 | @item Return value: |
5600ea19 NS |
37853 | If @var{len} is zero, the return value indicates whether a shell is |
37854 | available. A zero return value indicates a shell is not available. | |
37855 | For non-zero @var{len}, the value returned is -1 on error and the | |
37856 | return status of the command otherwise. Only the exit status of the | |
37857 | command is returned, which is extracted from the host's @code{system} | |
37858 | return value by calling @code{WEXITSTATUS(retval)}. In case | |
37859 | @file{/bin/sh} could not be executed, 127 is returned. | |
0ce1b118 | 37860 | |
fc320d37 | 37861 | @item Errors: |
0ce1b118 CV |
37862 | |
37863 | @table @code | |
b383017d | 37864 | @item EINTR |
0ce1b118 CV |
37865 | The call was interrupted by the user. |
37866 | @end table | |
37867 | ||
fc320d37 SL |
37868 | @end table |
37869 | ||
37870 | @value{GDBN} takes over the full task of calling the necessary host calls | |
37871 | to perform the @code{system} call. The return value of @code{system} on | |
37872 | the host is simplified before it's returned | |
37873 | to the target. Any termination signal information from the child process | |
37874 | is discarded, and the return value consists | |
37875 | entirely of the exit status of the called command. | |
37876 | ||
37877 | Due to security concerns, the @code{system} call is by default refused | |
37878 | by @value{GDBN}. The user has to allow this call explicitly with the | |
37879 | @code{set remote system-call-allowed 1} command. | |
37880 | ||
37881 | @table @code | |
37882 | @item set remote system-call-allowed | |
37883 | @kindex set remote system-call-allowed | |
37884 | Control whether to allow the @code{system} calls in the File I/O | |
37885 | protocol for the remote target. The default is zero (disabled). | |
37886 | ||
37887 | @item show remote system-call-allowed | |
37888 | @kindex show remote system-call-allowed | |
37889 | Show whether the @code{system} calls are allowed in the File I/O | |
37890 | protocol. | |
37891 | @end table | |
37892 | ||
db2e3e2e BW |
37893 | @node Protocol-specific Representation of Datatypes |
37894 | @subsection Protocol-specific Representation of Datatypes | |
37895 | @cindex protocol-specific representation of datatypes, in file-i/o protocol | |
0ce1b118 CV |
37896 | |
37897 | @menu | |
79a6e687 BW |
37898 | * Integral Datatypes:: |
37899 | * Pointer Values:: | |
37900 | * Memory Transfer:: | |
0ce1b118 CV |
37901 | * struct stat:: |
37902 | * struct timeval:: | |
37903 | @end menu | |
37904 | ||
79a6e687 BW |
37905 | @node Integral Datatypes |
37906 | @unnumberedsubsubsec Integral Datatypes | |
0ce1b118 CV |
37907 | @cindex integral datatypes, in file-i/o protocol |
37908 | ||
fc320d37 SL |
37909 | The integral datatypes used in the system calls are @code{int}, |
37910 | @code{unsigned int}, @code{long}, @code{unsigned long}, | |
37911 | @code{mode_t}, and @code{time_t}. | |
0ce1b118 | 37912 | |
fc320d37 | 37913 | @code{int}, @code{unsigned int}, @code{mode_t} and @code{time_t} are |
0ce1b118 CV |
37914 | implemented as 32 bit values in this protocol. |
37915 | ||
fc320d37 | 37916 | @code{long} and @code{unsigned long} are implemented as 64 bit types. |
b383017d | 37917 | |
0ce1b118 CV |
37918 | @xref{Limits}, for corresponding MIN and MAX values (similar to those |
37919 | in @file{limits.h}) to allow range checking on host and target. | |
37920 | ||
37921 | @code{time_t} datatypes are defined as seconds since the Epoch. | |
37922 | ||
37923 | All integral datatypes transferred as part of a memory read or write of a | |
37924 | structured datatype e.g.@: a @code{struct stat} have to be given in big endian | |
37925 | byte order. | |
37926 | ||
79a6e687 BW |
37927 | @node Pointer Values |
37928 | @unnumberedsubsubsec Pointer Values | |
0ce1b118 CV |
37929 | @cindex pointer values, in file-i/o protocol |
37930 | ||
37931 | Pointers to target data are transmitted as they are. An exception | |
37932 | is made for pointers to buffers for which the length isn't | |
37933 | transmitted as part of the function call, namely strings. Strings | |
37934 | are transmitted as a pointer/length pair, both as hex values, e.g.@: | |
37935 | ||
37936 | @smallexample | |
37937 | @code{1aaf/12} | |
37938 | @end smallexample | |
37939 | ||
37940 | @noindent | |
37941 | which is a pointer to data of length 18 bytes at position 0x1aaf. | |
37942 | The length is defined as the full string length in bytes, including | |
fc320d37 SL |
37943 | the trailing null byte. For example, the string @code{"hello world"} |
37944 | at address 0x123456 is transmitted as | |
0ce1b118 CV |
37945 | |
37946 | @smallexample | |
fc320d37 | 37947 | @code{123456/d} |
0ce1b118 CV |
37948 | @end smallexample |
37949 | ||
79a6e687 BW |
37950 | @node Memory Transfer |
37951 | @unnumberedsubsubsec Memory Transfer | |
fc320d37 SL |
37952 | @cindex memory transfer, in file-i/o protocol |
37953 | ||
37954 | Structured data which is transferred using a memory read or write (for | |
db2e3e2e | 37955 | example, a @code{struct stat}) is expected to be in a protocol-specific format |
fc320d37 SL |
37956 | with all scalar multibyte datatypes being big endian. Translation to |
37957 | this representation needs to be done both by the target before the @code{F} | |
37958 | packet is sent, and by @value{GDBN} before | |
37959 | it transfers memory to the target. Transferred pointers to structured | |
37960 | data should point to the already-coerced data at any time. | |
0ce1b118 | 37961 | |
0ce1b118 CV |
37962 | |
37963 | @node struct stat | |
37964 | @unnumberedsubsubsec struct stat | |
37965 | @cindex struct stat, in file-i/o protocol | |
37966 | ||
fc320d37 SL |
37967 | The buffer of type @code{struct stat} used by the target and @value{GDBN} |
37968 | is defined as follows: | |
0ce1b118 CV |
37969 | |
37970 | @smallexample | |
37971 | struct stat @{ | |
37972 | unsigned int st_dev; /* device */ | |
37973 | unsigned int st_ino; /* inode */ | |
37974 | mode_t st_mode; /* protection */ | |
37975 | unsigned int st_nlink; /* number of hard links */ | |
37976 | unsigned int st_uid; /* user ID of owner */ | |
37977 | unsigned int st_gid; /* group ID of owner */ | |
37978 | unsigned int st_rdev; /* device type (if inode device) */ | |
37979 | unsigned long st_size; /* total size, in bytes */ | |
37980 | unsigned long st_blksize; /* blocksize for filesystem I/O */ | |
37981 | unsigned long st_blocks; /* number of blocks allocated */ | |
37982 | time_t st_atime; /* time of last access */ | |
37983 | time_t st_mtime; /* time of last modification */ | |
37984 | time_t st_ctime; /* time of last change */ | |
37985 | @}; | |
37986 | @end smallexample | |
37987 | ||
fc320d37 | 37988 | The integral datatypes conform to the definitions given in the |
79a6e687 | 37989 | appropriate section (see @ref{Integral Datatypes}, for details) so this |
0ce1b118 CV |
37990 | structure is of size 64 bytes. |
37991 | ||
37992 | The values of several fields have a restricted meaning and/or | |
37993 | range of values. | |
37994 | ||
fc320d37 | 37995 | @table @code |
0ce1b118 | 37996 | |
fc320d37 SL |
37997 | @item st_dev |
37998 | A value of 0 represents a file, 1 the console. | |
0ce1b118 | 37999 | |
fc320d37 SL |
38000 | @item st_ino |
38001 | No valid meaning for the target. Transmitted unchanged. | |
0ce1b118 | 38002 | |
fc320d37 SL |
38003 | @item st_mode |
38004 | Valid mode bits are described in @ref{Constants}. Any other | |
38005 | bits have currently no meaning for the target. | |
0ce1b118 | 38006 | |
fc320d37 SL |
38007 | @item st_uid |
38008 | @itemx st_gid | |
38009 | @itemx st_rdev | |
38010 | No valid meaning for the target. Transmitted unchanged. | |
0ce1b118 | 38011 | |
fc320d37 SL |
38012 | @item st_atime |
38013 | @itemx st_mtime | |
38014 | @itemx st_ctime | |
38015 | These values have a host and file system dependent | |
38016 | accuracy. Especially on Windows hosts, the file system may not | |
38017 | support exact timing values. | |
38018 | @end table | |
0ce1b118 | 38019 | |
fc320d37 SL |
38020 | The target gets a @code{struct stat} of the above representation and is |
38021 | responsible for coercing it to the target representation before | |
0ce1b118 CV |
38022 | continuing. |
38023 | ||
fc320d37 SL |
38024 | Note that due to size differences between the host, target, and protocol |
38025 | representations of @code{struct stat} members, these members could eventually | |
0ce1b118 CV |
38026 | get truncated on the target. |
38027 | ||
38028 | @node struct timeval | |
38029 | @unnumberedsubsubsec struct timeval | |
38030 | @cindex struct timeval, in file-i/o protocol | |
38031 | ||
fc320d37 | 38032 | The buffer of type @code{struct timeval} used by the File-I/O protocol |
0ce1b118 CV |
38033 | is defined as follows: |
38034 | ||
38035 | @smallexample | |
b383017d | 38036 | struct timeval @{ |
0ce1b118 CV |
38037 | time_t tv_sec; /* second */ |
38038 | long tv_usec; /* microsecond */ | |
38039 | @}; | |
38040 | @end smallexample | |
38041 | ||
fc320d37 | 38042 | The integral datatypes conform to the definitions given in the |
79a6e687 | 38043 | appropriate section (see @ref{Integral Datatypes}, for details) so this |
0ce1b118 CV |
38044 | structure is of size 8 bytes. |
38045 | ||
38046 | @node Constants | |
38047 | @subsection Constants | |
38048 | @cindex constants, in file-i/o protocol | |
38049 | ||
38050 | The following values are used for the constants inside of the | |
fc320d37 | 38051 | protocol. @value{GDBN} and target are responsible for translating these |
0ce1b118 CV |
38052 | values before and after the call as needed. |
38053 | ||
38054 | @menu | |
79a6e687 BW |
38055 | * Open Flags:: |
38056 | * mode_t Values:: | |
38057 | * Errno Values:: | |
38058 | * Lseek Flags:: | |
0ce1b118 CV |
38059 | * Limits:: |
38060 | @end menu | |
38061 | ||
79a6e687 BW |
38062 | @node Open Flags |
38063 | @unnumberedsubsubsec Open Flags | |
0ce1b118 CV |
38064 | @cindex open flags, in file-i/o protocol |
38065 | ||
38066 | All values are given in hexadecimal representation. | |
38067 | ||
38068 | @smallexample | |
38069 | O_RDONLY 0x0 | |
38070 | O_WRONLY 0x1 | |
38071 | O_RDWR 0x2 | |
38072 | O_APPEND 0x8 | |
38073 | O_CREAT 0x200 | |
38074 | O_TRUNC 0x400 | |
38075 | O_EXCL 0x800 | |
38076 | @end smallexample | |
38077 | ||
79a6e687 BW |
38078 | @node mode_t Values |
38079 | @unnumberedsubsubsec mode_t Values | |
0ce1b118 CV |
38080 | @cindex mode_t values, in file-i/o protocol |
38081 | ||
38082 | All values are given in octal representation. | |
38083 | ||
38084 | @smallexample | |
38085 | S_IFREG 0100000 | |
38086 | S_IFDIR 040000 | |
38087 | S_IRUSR 0400 | |
38088 | S_IWUSR 0200 | |
38089 | S_IXUSR 0100 | |
38090 | S_IRGRP 040 | |
38091 | S_IWGRP 020 | |
38092 | S_IXGRP 010 | |
38093 | S_IROTH 04 | |
38094 | S_IWOTH 02 | |
38095 | S_IXOTH 01 | |
38096 | @end smallexample | |
38097 | ||
79a6e687 BW |
38098 | @node Errno Values |
38099 | @unnumberedsubsubsec Errno Values | |
0ce1b118 CV |
38100 | @cindex errno values, in file-i/o protocol |
38101 | ||
38102 | All values are given in decimal representation. | |
38103 | ||
38104 | @smallexample | |
38105 | EPERM 1 | |
38106 | ENOENT 2 | |
38107 | EINTR 4 | |
38108 | EBADF 9 | |
38109 | EACCES 13 | |
38110 | EFAULT 14 | |
38111 | EBUSY 16 | |
38112 | EEXIST 17 | |
38113 | ENODEV 19 | |
38114 | ENOTDIR 20 | |
38115 | EISDIR 21 | |
38116 | EINVAL 22 | |
38117 | ENFILE 23 | |
38118 | EMFILE 24 | |
38119 | EFBIG 27 | |
38120 | ENOSPC 28 | |
38121 | ESPIPE 29 | |
38122 | EROFS 30 | |
38123 | ENAMETOOLONG 91 | |
38124 | EUNKNOWN 9999 | |
38125 | @end smallexample | |
38126 | ||
fc320d37 | 38127 | @code{EUNKNOWN} is used as a fallback error value if a host system returns |
0ce1b118 CV |
38128 | any error value not in the list of supported error numbers. |
38129 | ||
79a6e687 BW |
38130 | @node Lseek Flags |
38131 | @unnumberedsubsubsec Lseek Flags | |
0ce1b118 CV |
38132 | @cindex lseek flags, in file-i/o protocol |
38133 | ||
38134 | @smallexample | |
38135 | SEEK_SET 0 | |
38136 | SEEK_CUR 1 | |
38137 | SEEK_END 2 | |
38138 | @end smallexample | |
38139 | ||
38140 | @node Limits | |
38141 | @unnumberedsubsubsec Limits | |
38142 | @cindex limits, in file-i/o protocol | |
38143 | ||
38144 | All values are given in decimal representation. | |
38145 | ||
38146 | @smallexample | |
38147 | INT_MIN -2147483648 | |
38148 | INT_MAX 2147483647 | |
38149 | UINT_MAX 4294967295 | |
38150 | LONG_MIN -9223372036854775808 | |
38151 | LONG_MAX 9223372036854775807 | |
38152 | ULONG_MAX 18446744073709551615 | |
38153 | @end smallexample | |
38154 | ||
38155 | @node File-I/O Examples | |
38156 | @subsection File-I/O Examples | |
38157 | @cindex file-i/o examples | |
38158 | ||
38159 | Example sequence of a write call, file descriptor 3, buffer is at target | |
38160 | address 0x1234, 6 bytes should be written: | |
38161 | ||
38162 | @smallexample | |
38163 | <- @code{Fwrite,3,1234,6} | |
38164 | @emph{request memory read from target} | |
38165 | -> @code{m1234,6} | |
38166 | <- XXXXXX | |
38167 | @emph{return "6 bytes written"} | |
38168 | -> @code{F6} | |
38169 | @end smallexample | |
38170 | ||
38171 | Example sequence of a read call, file descriptor 3, buffer is at target | |
38172 | address 0x1234, 6 bytes should be read: | |
38173 | ||
38174 | @smallexample | |
38175 | <- @code{Fread,3,1234,6} | |
38176 | @emph{request memory write to target} | |
38177 | -> @code{X1234,6:XXXXXX} | |
38178 | @emph{return "6 bytes read"} | |
38179 | -> @code{F6} | |
38180 | @end smallexample | |
38181 | ||
38182 | Example sequence of a read call, call fails on the host due to invalid | |
fc320d37 | 38183 | file descriptor (@code{EBADF}): |
0ce1b118 CV |
38184 | |
38185 | @smallexample | |
38186 | <- @code{Fread,3,1234,6} | |
38187 | -> @code{F-1,9} | |
38188 | @end smallexample | |
38189 | ||
c8aa23ab | 38190 | Example sequence of a read call, user presses @kbd{Ctrl-c} before syscall on |
0ce1b118 CV |
38191 | host is called: |
38192 | ||
38193 | @smallexample | |
38194 | <- @code{Fread,3,1234,6} | |
38195 | -> @code{F-1,4,C} | |
38196 | <- @code{T02} | |
38197 | @end smallexample | |
38198 | ||
c8aa23ab | 38199 | Example sequence of a read call, user presses @kbd{Ctrl-c} after syscall on |
0ce1b118 CV |
38200 | host is called: |
38201 | ||
38202 | @smallexample | |
38203 | <- @code{Fread,3,1234,6} | |
38204 | -> @code{X1234,6:XXXXXX} | |
38205 | <- @code{T02} | |
38206 | @end smallexample | |
38207 | ||
cfa9d6d9 DJ |
38208 | @node Library List Format |
38209 | @section Library List Format | |
38210 | @cindex library list format, remote protocol | |
38211 | ||
38212 | On some platforms, a dynamic loader (e.g.@: @file{ld.so}) runs in the | |
38213 | same process as your application to manage libraries. In this case, | |
38214 | @value{GDBN} can use the loader's symbol table and normal memory | |
38215 | operations to maintain a list of shared libraries. On other | |
38216 | platforms, the operating system manages loaded libraries. | |
38217 | @value{GDBN} can not retrieve the list of currently loaded libraries | |
38218 | through memory operations, so it uses the @samp{qXfer:libraries:read} | |
38219 | packet (@pxref{qXfer library list read}) instead. The remote stub | |
38220 | queries the target's operating system and reports which libraries | |
38221 | are loaded. | |
38222 | ||
38223 | The @samp{qXfer:libraries:read} packet returns an XML document which | |
38224 | lists loaded libraries and their offsets. Each library has an | |
1fddbabb PA |
38225 | associated name and one or more segment or section base addresses, |
38226 | which report where the library was loaded in memory. | |
38227 | ||
38228 | For the common case of libraries that are fully linked binaries, the | |
38229 | library should have a list of segments. If the target supports | |
38230 | dynamic linking of a relocatable object file, its library XML element | |
38231 | should instead include a list of allocated sections. The segment or | |
38232 | section bases are start addresses, not relocation offsets; they do not | |
38233 | depend on the library's link-time base addresses. | |
cfa9d6d9 | 38234 | |
9cceb671 DJ |
38235 | @value{GDBN} must be linked with the Expat library to support XML |
38236 | library lists. @xref{Expat}. | |
38237 | ||
cfa9d6d9 DJ |
38238 | A simple memory map, with one loaded library relocated by a single |
38239 | offset, looks like this: | |
38240 | ||
38241 | @smallexample | |
38242 | <library-list> | |
38243 | <library name="/lib/libc.so.6"> | |
38244 | <segment address="0x10000000"/> | |
38245 | </library> | |
38246 | </library-list> | |
38247 | @end smallexample | |
38248 | ||
1fddbabb PA |
38249 | Another simple memory map, with one loaded library with three |
38250 | allocated sections (.text, .data, .bss), looks like this: | |
38251 | ||
38252 | @smallexample | |
38253 | <library-list> | |
38254 | <library name="sharedlib.o"> | |
38255 | <section address="0x10000000"/> | |
38256 | <section address="0x20000000"/> | |
38257 | <section address="0x30000000"/> | |
38258 | </library> | |
38259 | </library-list> | |
38260 | @end smallexample | |
38261 | ||
cfa9d6d9 DJ |
38262 | The format of a library list is described by this DTD: |
38263 | ||
38264 | @smallexample | |
38265 | <!-- library-list: Root element with versioning --> | |
38266 | <!ELEMENT library-list (library)*> | |
38267 | <!ATTLIST library-list version CDATA #FIXED "1.0"> | |
1fddbabb | 38268 | <!ELEMENT library (segment*, section*)> |
cfa9d6d9 DJ |
38269 | <!ATTLIST library name CDATA #REQUIRED> |
38270 | <!ELEMENT segment EMPTY> | |
38271 | <!ATTLIST segment address CDATA #REQUIRED> | |
1fddbabb PA |
38272 | <!ELEMENT section EMPTY> |
38273 | <!ATTLIST section address CDATA #REQUIRED> | |
cfa9d6d9 DJ |
38274 | @end smallexample |
38275 | ||
1fddbabb PA |
38276 | In addition, segments and section descriptors cannot be mixed within a |
38277 | single library element, and you must supply at least one segment or | |
38278 | section for each library. | |
38279 | ||
2268b414 JK |
38280 | @node Library List Format for SVR4 Targets |
38281 | @section Library List Format for SVR4 Targets | |
38282 | @cindex library list format, remote protocol | |
38283 | ||
38284 | On SVR4 platforms @value{GDBN} can use the symbol table of a dynamic loader | |
38285 | (e.g.@: @file{ld.so}) and normal memory operations to maintain a list of | |
38286 | shared libraries. Still a special library list provided by this packet is | |
38287 | more efficient for the @value{GDBN} remote protocol. | |
38288 | ||
38289 | The @samp{qXfer:libraries-svr4:read} packet returns an XML document which lists | |
38290 | loaded libraries and their SVR4 linker parameters. For each library on SVR4 | |
38291 | target, the following parameters are reported: | |
38292 | ||
38293 | @itemize @minus | |
38294 | @item | |
38295 | @code{name}, the absolute file name from the @code{l_name} field of | |
38296 | @code{struct link_map}. | |
38297 | @item | |
38298 | @code{lm} with address of @code{struct link_map} used for TLS | |
38299 | (Thread Local Storage) access. | |
38300 | @item | |
38301 | @code{l_addr}, the displacement as read from the field @code{l_addr} of | |
38302 | @code{struct link_map}. For prelinked libraries this is not an absolute | |
38303 | memory address. It is a displacement of absolute memory address against | |
38304 | address the file was prelinked to during the library load. | |
38305 | @item | |
38306 | @code{l_ld}, which is memory address of the @code{PT_DYNAMIC} segment | |
38307 | @end itemize | |
38308 | ||
38309 | Additionally the single @code{main-lm} attribute specifies address of | |
38310 | @code{struct link_map} used for the main executable. This parameter is used | |
38311 | for TLS access and its presence is optional. | |
38312 | ||
38313 | @value{GDBN} must be linked with the Expat library to support XML | |
38314 | SVR4 library lists. @xref{Expat}. | |
38315 | ||
38316 | A simple memory map, with two loaded libraries (which do not use prelink), | |
38317 | looks like this: | |
38318 | ||
38319 | @smallexample | |
38320 | <library-list-svr4 version="1.0" main-lm="0xe4f8f8"> | |
38321 | <library name="/lib/ld-linux.so.2" lm="0xe4f51c" l_addr="0xe2d000" | |
38322 | l_ld="0xe4eefc"/> | |
38323 | <library name="/lib/libc.so.6" lm="0xe4fbe8" l_addr="0x154000" | |
38324 | l_ld="0x152350"/> | |
38325 | </library-list-svr> | |
38326 | @end smallexample | |
38327 | ||
38328 | The format of an SVR4 library list is described by this DTD: | |
38329 | ||
38330 | @smallexample | |
38331 | <!-- library-list-svr4: Root element with versioning --> | |
38332 | <!ELEMENT library-list-svr4 (library)*> | |
38333 | <!ATTLIST library-list-svr4 version CDATA #FIXED "1.0"> | |
38334 | <!ATTLIST library-list-svr4 main-lm CDATA #IMPLIED> | |
38335 | <!ELEMENT library EMPTY> | |
38336 | <!ATTLIST library name CDATA #REQUIRED> | |
38337 | <!ATTLIST library lm CDATA #REQUIRED> | |
38338 | <!ATTLIST library l_addr CDATA #REQUIRED> | |
38339 | <!ATTLIST library l_ld CDATA #REQUIRED> | |
38340 | @end smallexample | |
38341 | ||
79a6e687 BW |
38342 | @node Memory Map Format |
38343 | @section Memory Map Format | |
68437a39 DJ |
38344 | @cindex memory map format |
38345 | ||
38346 | To be able to write into flash memory, @value{GDBN} needs to obtain a | |
38347 | memory map from the target. This section describes the format of the | |
38348 | memory map. | |
38349 | ||
38350 | The memory map is obtained using the @samp{qXfer:memory-map:read} | |
38351 | (@pxref{qXfer memory map read}) packet and is an XML document that | |
9cceb671 DJ |
38352 | lists memory regions. |
38353 | ||
38354 | @value{GDBN} must be linked with the Expat library to support XML | |
38355 | memory maps. @xref{Expat}. | |
38356 | ||
38357 | The top-level structure of the document is shown below: | |
68437a39 DJ |
38358 | |
38359 | @smallexample | |
38360 | <?xml version="1.0"?> | |
38361 | <!DOCTYPE memory-map | |
38362 | PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN" | |
38363 | "http://sourceware.org/gdb/gdb-memory-map.dtd"> | |
38364 | <memory-map> | |
38365 | region... | |
38366 | </memory-map> | |
38367 | @end smallexample | |
38368 | ||
38369 | Each region can be either: | |
38370 | ||
38371 | @itemize | |
38372 | ||
38373 | @item | |
38374 | A region of RAM starting at @var{addr} and extending for @var{length} | |
38375 | bytes from there: | |
38376 | ||
38377 | @smallexample | |
38378 | <memory type="ram" start="@var{addr}" length="@var{length}"/> | |
38379 | @end smallexample | |
38380 | ||
38381 | ||
38382 | @item | |
38383 | A region of read-only memory: | |
38384 | ||
38385 | @smallexample | |
38386 | <memory type="rom" start="@var{addr}" length="@var{length}"/> | |
38387 | @end smallexample | |
38388 | ||
38389 | ||
38390 | @item | |
38391 | A region of flash memory, with erasure blocks @var{blocksize} | |
38392 | bytes in length: | |
38393 | ||
38394 | @smallexample | |
38395 | <memory type="flash" start="@var{addr}" length="@var{length}"> | |
38396 | <property name="blocksize">@var{blocksize}</property> | |
38397 | </memory> | |
38398 | @end smallexample | |
38399 | ||
38400 | @end itemize | |
38401 | ||
38402 | Regions must not overlap. @value{GDBN} assumes that areas of memory not covered | |
38403 | by the memory map are RAM, and uses the ordinary @samp{M} and @samp{X} | |
38404 | packets to write to addresses in such ranges. | |
38405 | ||
38406 | The formal DTD for memory map format is given below: | |
38407 | ||
38408 | @smallexample | |
38409 | <!-- ................................................... --> | |
38410 | <!-- Memory Map XML DTD ................................ --> | |
38411 | <!-- File: memory-map.dtd .............................. --> | |
38412 | <!-- .................................... .............. --> | |
38413 | <!-- memory-map.dtd --> | |
38414 | <!-- memory-map: Root element with versioning --> | |
38415 | <!ELEMENT memory-map (memory | property)> | |
38416 | <!ATTLIST memory-map version CDATA #FIXED "1.0.0"> | |
38417 | <!ELEMENT memory (property)> | |
38418 | <!-- memory: Specifies a memory region, | |
38419 | and its type, or device. --> | |
38420 | <!ATTLIST memory type CDATA #REQUIRED | |
38421 | start CDATA #REQUIRED | |
38422 | length CDATA #REQUIRED | |
38423 | device CDATA #IMPLIED> | |
38424 | <!-- property: Generic attribute tag --> | |
38425 | <!ELEMENT property (#PCDATA | property)*> | |
38426 | <!ATTLIST property name CDATA #REQUIRED> | |
38427 | @end smallexample | |
38428 | ||
dc146f7c VP |
38429 | @node Thread List Format |
38430 | @section Thread List Format | |
38431 | @cindex thread list format | |
38432 | ||
38433 | To efficiently update the list of threads and their attributes, | |
38434 | @value{GDBN} issues the @samp{qXfer:threads:read} packet | |
38435 | (@pxref{qXfer threads read}) and obtains the XML document with | |
38436 | the following structure: | |
38437 | ||
38438 | @smallexample | |
38439 | <?xml version="1.0"?> | |
38440 | <threads> | |
38441 | <thread id="id" core="0"> | |
38442 | ... description ... | |
38443 | </thread> | |
38444 | </threads> | |
38445 | @end smallexample | |
38446 | ||
38447 | Each @samp{thread} element must have the @samp{id} attribute that | |
38448 | identifies the thread (@pxref{thread-id syntax}). The | |
38449 | @samp{core} attribute, if present, specifies which processor core | |
38450 | the thread was last executing on. The content of the of @samp{thread} | |
38451 | element is interpreted as human-readable auxilliary information. | |
38452 | ||
b3b9301e PA |
38453 | @node Traceframe Info Format |
38454 | @section Traceframe Info Format | |
38455 | @cindex traceframe info format | |
38456 | ||
38457 | To be able to know which objects in the inferior can be examined when | |
38458 | inspecting a tracepoint hit, @value{GDBN} needs to obtain the list of | |
38459 | memory ranges, registers and trace state variables that have been | |
38460 | collected in a traceframe. | |
38461 | ||
38462 | This list is obtained using the @samp{qXfer:traceframe-info:read} | |
38463 | (@pxref{qXfer traceframe info read}) packet and is an XML document. | |
38464 | ||
38465 | @value{GDBN} must be linked with the Expat library to support XML | |
38466 | traceframe info discovery. @xref{Expat}. | |
38467 | ||
38468 | The top-level structure of the document is shown below: | |
38469 | ||
38470 | @smallexample | |
38471 | <?xml version="1.0"?> | |
38472 | <!DOCTYPE traceframe-info | |
38473 | PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN" | |
38474 | "http://sourceware.org/gdb/gdb-traceframe-info.dtd"> | |
38475 | <traceframe-info> | |
38476 | block... | |
38477 | </traceframe-info> | |
38478 | @end smallexample | |
38479 | ||
38480 | Each traceframe block can be either: | |
38481 | ||
38482 | @itemize | |
38483 | ||
38484 | @item | |
38485 | A region of collected memory starting at @var{addr} and extending for | |
38486 | @var{length} bytes from there: | |
38487 | ||
38488 | @smallexample | |
38489 | <memory start="@var{addr}" length="@var{length}"/> | |
38490 | @end smallexample | |
38491 | ||
28a93511 YQ |
38492 | @item |
38493 | A block indicating trace state variable numbered @var{number} has been | |
38494 | collected: | |
38495 | ||
38496 | @smallexample | |
38497 | <tvar id="@var{number}"/> | |
38498 | @end smallexample | |
38499 | ||
b3b9301e PA |
38500 | @end itemize |
38501 | ||
38502 | The formal DTD for the traceframe info format is given below: | |
38503 | ||
38504 | @smallexample | |
28a93511 | 38505 | <!ELEMENT traceframe-info (memory | tvar)* > |
b3b9301e PA |
38506 | <!ATTLIST traceframe-info version CDATA #FIXED "1.0"> |
38507 | ||
38508 | <!ELEMENT memory EMPTY> | |
38509 | <!ATTLIST memory start CDATA #REQUIRED | |
38510 | length CDATA #REQUIRED> | |
28a93511 YQ |
38511 | <!ELEMENT tvar> |
38512 | <!ATTLIST tvar id CDATA #REQUIRED> | |
b3b9301e PA |
38513 | @end smallexample |
38514 | ||
2ae8c8e7 MM |
38515 | @node Branch Trace Format |
38516 | @section Branch Trace Format | |
38517 | @cindex branch trace format | |
38518 | ||
38519 | In order to display the branch trace of an inferior thread, | |
38520 | @value{GDBN} needs to obtain the list of branches. This list is | |
38521 | represented as list of sequential code blocks that are connected via | |
38522 | branches. The code in each block has been executed sequentially. | |
38523 | ||
38524 | This list is obtained using the @samp{qXfer:btrace:read} | |
38525 | (@pxref{qXfer btrace read}) packet and is an XML document. | |
38526 | ||
38527 | @value{GDBN} must be linked with the Expat library to support XML | |
38528 | traceframe info discovery. @xref{Expat}. | |
38529 | ||
38530 | The top-level structure of the document is shown below: | |
38531 | ||
38532 | @smallexample | |
38533 | <?xml version="1.0"?> | |
38534 | <!DOCTYPE btrace | |
38535 | PUBLIC "+//IDN gnu.org//DTD GDB Branch Trace V1.0//EN" | |
38536 | "http://sourceware.org/gdb/gdb-btrace.dtd"> | |
38537 | <btrace> | |
38538 | block... | |
38539 | </btrace> | |
38540 | @end smallexample | |
38541 | ||
38542 | @itemize | |
38543 | ||
38544 | @item | |
38545 | A block of sequentially executed instructions starting at @var{begin} | |
38546 | and ending at @var{end}: | |
38547 | ||
38548 | @smallexample | |
38549 | <block begin="@var{begin}" end="@var{end}"/> | |
38550 | @end smallexample | |
38551 | ||
38552 | @end itemize | |
38553 | ||
38554 | The formal DTD for the branch trace format is given below: | |
38555 | ||
38556 | @smallexample | |
38557 | <!ELEMENT btrace (block)* > | |
38558 | <!ATTLIST btrace version CDATA #FIXED "1.0"> | |
38559 | ||
38560 | <!ELEMENT block EMPTY> | |
38561 | <!ATTLIST block begin CDATA #REQUIRED | |
38562 | end CDATA #REQUIRED> | |
38563 | @end smallexample | |
38564 | ||
f418dd93 DJ |
38565 | @include agentexpr.texi |
38566 | ||
23181151 DJ |
38567 | @node Target Descriptions |
38568 | @appendix Target Descriptions | |
38569 | @cindex target descriptions | |
38570 | ||
23181151 DJ |
38571 | One of the challenges of using @value{GDBN} to debug embedded systems |
38572 | is that there are so many minor variants of each processor | |
38573 | architecture in use. It is common practice for vendors to start with | |
eb17f351 | 38574 | a standard processor core --- ARM, PowerPC, or @acronym{MIPS}, for example --- |
23181151 DJ |
38575 | and then make changes to adapt it to a particular market niche. Some |
38576 | architectures have hundreds of variants, available from dozens of | |
38577 | vendors. This leads to a number of problems: | |
38578 | ||
38579 | @itemize @bullet | |
38580 | @item | |
38581 | With so many different customized processors, it is difficult for | |
38582 | the @value{GDBN} maintainers to keep up with the changes. | |
38583 | @item | |
38584 | Since individual variants may have short lifetimes or limited | |
38585 | audiences, it may not be worthwhile to carry information about every | |
38586 | variant in the @value{GDBN} source tree. | |
38587 | @item | |
38588 | When @value{GDBN} does support the architecture of the embedded system | |
38589 | at hand, the task of finding the correct architecture name to give the | |
38590 | @command{set architecture} command can be error-prone. | |
38591 | @end itemize | |
38592 | ||
38593 | To address these problems, the @value{GDBN} remote protocol allows a | |
38594 | target system to not only identify itself to @value{GDBN}, but to | |
38595 | actually describe its own features. This lets @value{GDBN} support | |
38596 | processor variants it has never seen before --- to the extent that the | |
38597 | descriptions are accurate, and that @value{GDBN} understands them. | |
38598 | ||
9cceb671 DJ |
38599 | @value{GDBN} must be linked with the Expat library to support XML |
38600 | target descriptions. @xref{Expat}. | |
123dc839 | 38601 | |
23181151 DJ |
38602 | @menu |
38603 | * Retrieving Descriptions:: How descriptions are fetched from a target. | |
38604 | * Target Description Format:: The contents of a target description. | |
123dc839 DJ |
38605 | * Predefined Target Types:: Standard types available for target |
38606 | descriptions. | |
38607 | * Standard Target Features:: Features @value{GDBN} knows about. | |
23181151 DJ |
38608 | @end menu |
38609 | ||
38610 | @node Retrieving Descriptions | |
38611 | @section Retrieving Descriptions | |
38612 | ||
38613 | Target descriptions can be read from the target automatically, or | |
38614 | specified by the user manually. The default behavior is to read the | |
38615 | description from the target. @value{GDBN} retrieves it via the remote | |
38616 | protocol using @samp{qXfer} requests (@pxref{General Query Packets, | |
38617 | qXfer}). The @var{annex} in the @samp{qXfer} packet will be | |
38618 | @samp{target.xml}. The contents of the @samp{target.xml} annex are an | |
38619 | XML document, of the form described in @ref{Target Description | |
38620 | Format}. | |
38621 | ||
38622 | Alternatively, you can specify a file to read for the target description. | |
38623 | If a file is set, the target will not be queried. The commands to | |
38624 | specify a file are: | |
38625 | ||
38626 | @table @code | |
38627 | @cindex set tdesc filename | |
38628 | @item set tdesc filename @var{path} | |
38629 | Read the target description from @var{path}. | |
38630 | ||
38631 | @cindex unset tdesc filename | |
38632 | @item unset tdesc filename | |
38633 | Do not read the XML target description from a file. @value{GDBN} | |
38634 | will use the description supplied by the current target. | |
38635 | ||
38636 | @cindex show tdesc filename | |
38637 | @item show tdesc filename | |
38638 | Show the filename to read for a target description, if any. | |
38639 | @end table | |
38640 | ||
38641 | ||
38642 | @node Target Description Format | |
38643 | @section Target Description Format | |
38644 | @cindex target descriptions, XML format | |
38645 | ||
38646 | A target description annex is an @uref{http://www.w3.org/XML/, XML} | |
38647 | document which complies with the Document Type Definition provided in | |
38648 | the @value{GDBN} sources in @file{gdb/features/gdb-target.dtd}. This | |
38649 | means you can use generally available tools like @command{xmllint} to | |
38650 | check that your feature descriptions are well-formed and valid. | |
38651 | However, to help people unfamiliar with XML write descriptions for | |
38652 | their targets, we also describe the grammar here. | |
38653 | ||
123dc839 DJ |
38654 | Target descriptions can identify the architecture of the remote target |
38655 | and (for some architectures) provide information about custom register | |
08d16641 PA |
38656 | sets. They can also identify the OS ABI of the remote target. |
38657 | @value{GDBN} can use this information to autoconfigure for your | |
123dc839 | 38658 | target, or to warn you if you connect to an unsupported target. |
23181151 DJ |
38659 | |
38660 | Here is a simple target description: | |
38661 | ||
123dc839 | 38662 | @smallexample |
1780a0ed | 38663 | <target version="1.0"> |
23181151 DJ |
38664 | <architecture>i386:x86-64</architecture> |
38665 | </target> | |
123dc839 | 38666 | @end smallexample |
23181151 DJ |
38667 | |
38668 | @noindent | |
38669 | This minimal description only says that the target uses | |
38670 | the x86-64 architecture. | |
38671 | ||
123dc839 DJ |
38672 | A target description has the following overall form, with [ ] marking |
38673 | optional elements and @dots{} marking repeatable elements. The elements | |
38674 | are explained further below. | |
23181151 | 38675 | |
123dc839 | 38676 | @smallexample |
23181151 DJ |
38677 | <?xml version="1.0"?> |
38678 | <!DOCTYPE target SYSTEM "gdb-target.dtd"> | |
1780a0ed | 38679 | <target version="1.0"> |
123dc839 | 38680 | @r{[}@var{architecture}@r{]} |
08d16641 | 38681 | @r{[}@var{osabi}@r{]} |
e35359c5 | 38682 | @r{[}@var{compatible}@r{]} |
123dc839 | 38683 | @r{[}@var{feature}@dots{}@r{]} |
23181151 | 38684 | </target> |
123dc839 | 38685 | @end smallexample |
23181151 DJ |
38686 | |
38687 | @noindent | |
38688 | The description is generally insensitive to whitespace and line | |
38689 | breaks, under the usual common-sense rules. The XML version | |
38690 | declaration and document type declaration can generally be omitted | |
38691 | (@value{GDBN} does not require them), but specifying them may be | |
1780a0ed DJ |
38692 | useful for XML validation tools. The @samp{version} attribute for |
38693 | @samp{<target>} may also be omitted, but we recommend | |
38694 | including it; if future versions of @value{GDBN} use an incompatible | |
38695 | revision of @file{gdb-target.dtd}, they will detect and report | |
38696 | the version mismatch. | |
23181151 | 38697 | |
108546a0 DJ |
38698 | @subsection Inclusion |
38699 | @cindex target descriptions, inclusion | |
38700 | @cindex XInclude | |
38701 | @ifnotinfo | |
38702 | @cindex <xi:include> | |
38703 | @end ifnotinfo | |
38704 | ||
38705 | It can sometimes be valuable to split a target description up into | |
38706 | several different annexes, either for organizational purposes, or to | |
38707 | share files between different possible target descriptions. You can | |
38708 | divide a description into multiple files by replacing any element of | |
38709 | the target description with an inclusion directive of the form: | |
38710 | ||
123dc839 | 38711 | @smallexample |
108546a0 | 38712 | <xi:include href="@var{document}"/> |
123dc839 | 38713 | @end smallexample |
108546a0 DJ |
38714 | |
38715 | @noindent | |
38716 | When @value{GDBN} encounters an element of this form, it will retrieve | |
38717 | the named XML @var{document}, and replace the inclusion directive with | |
38718 | the contents of that document. If the current description was read | |
38719 | using @samp{qXfer}, then so will be the included document; | |
38720 | @var{document} will be interpreted as the name of an annex. If the | |
38721 | current description was read from a file, @value{GDBN} will look for | |
38722 | @var{document} as a file in the same directory where it found the | |
38723 | original description. | |
38724 | ||
123dc839 DJ |
38725 | @subsection Architecture |
38726 | @cindex <architecture> | |
38727 | ||
38728 | An @samp{<architecture>} element has this form: | |
38729 | ||
38730 | @smallexample | |
38731 | <architecture>@var{arch}</architecture> | |
38732 | @end smallexample | |
38733 | ||
e35359c5 UW |
38734 | @var{arch} is one of the architectures from the set accepted by |
38735 | @code{set architecture} (@pxref{Targets, ,Specifying a Debugging Target}). | |
123dc839 | 38736 | |
08d16641 PA |
38737 | @subsection OS ABI |
38738 | @cindex @code{<osabi>} | |
38739 | ||
38740 | This optional field was introduced in @value{GDBN} version 7.0. | |
38741 | Previous versions of @value{GDBN} ignore it. | |
38742 | ||
38743 | An @samp{<osabi>} element has this form: | |
38744 | ||
38745 | @smallexample | |
38746 | <osabi>@var{abi-name}</osabi> | |
38747 | @end smallexample | |
38748 | ||
38749 | @var{abi-name} is an OS ABI name from the same selection accepted by | |
38750 | @w{@code{set osabi}} (@pxref{ABI, ,Configuring the Current ABI}). | |
38751 | ||
e35359c5 UW |
38752 | @subsection Compatible Architecture |
38753 | @cindex @code{<compatible>} | |
38754 | ||
38755 | This optional field was introduced in @value{GDBN} version 7.0. | |
38756 | Previous versions of @value{GDBN} ignore it. | |
38757 | ||
38758 | A @samp{<compatible>} element has this form: | |
38759 | ||
38760 | @smallexample | |
38761 | <compatible>@var{arch}</compatible> | |
38762 | @end smallexample | |
38763 | ||
38764 | @var{arch} is one of the architectures from the set accepted by | |
38765 | @code{set architecture} (@pxref{Targets, ,Specifying a Debugging Target}). | |
38766 | ||
38767 | A @samp{<compatible>} element is used to specify that the target | |
38768 | is able to run binaries in some other than the main target architecture | |
38769 | given by the @samp{<architecture>} element. For example, on the | |
38770 | Cell Broadband Engine, the main architecture is @code{powerpc:common} | |
38771 | or @code{powerpc:common64}, but the system is able to run binaries | |
38772 | in the @code{spu} architecture as well. The way to describe this | |
38773 | capability with @samp{<compatible>} is as follows: | |
38774 | ||
38775 | @smallexample | |
38776 | <architecture>powerpc:common</architecture> | |
38777 | <compatible>spu</compatible> | |
38778 | @end smallexample | |
38779 | ||
123dc839 DJ |
38780 | @subsection Features |
38781 | @cindex <feature> | |
38782 | ||
38783 | Each @samp{<feature>} describes some logical portion of the target | |
38784 | system. Features are currently used to describe available CPU | |
38785 | registers and the types of their contents. A @samp{<feature>} element | |
38786 | has this form: | |
38787 | ||
38788 | @smallexample | |
38789 | <feature name="@var{name}"> | |
38790 | @r{[}@var{type}@dots{}@r{]} | |
38791 | @var{reg}@dots{} | |
38792 | </feature> | |
38793 | @end smallexample | |
38794 | ||
38795 | @noindent | |
38796 | Each feature's name should be unique within the description. The name | |
38797 | of a feature does not matter unless @value{GDBN} has some special | |
38798 | knowledge of the contents of that feature; if it does, the feature | |
38799 | should have its standard name. @xref{Standard Target Features}. | |
38800 | ||
38801 | @subsection Types | |
38802 | ||
38803 | Any register's value is a collection of bits which @value{GDBN} must | |
38804 | interpret. The default interpretation is a two's complement integer, | |
38805 | but other types can be requested by name in the register description. | |
38806 | Some predefined types are provided by @value{GDBN} (@pxref{Predefined | |
38807 | Target Types}), and the description can define additional composite types. | |
38808 | ||
38809 | Each type element must have an @samp{id} attribute, which gives | |
38810 | a unique (within the containing @samp{<feature>}) name to the type. | |
38811 | Types must be defined before they are used. | |
38812 | ||
38813 | @cindex <vector> | |
38814 | Some targets offer vector registers, which can be treated as arrays | |
38815 | of scalar elements. These types are written as @samp{<vector>} elements, | |
38816 | specifying the array element type, @var{type}, and the number of elements, | |
38817 | @var{count}: | |
38818 | ||
38819 | @smallexample | |
38820 | <vector id="@var{id}" type="@var{type}" count="@var{count}"/> | |
38821 | @end smallexample | |
38822 | ||
38823 | @cindex <union> | |
38824 | If a register's value is usefully viewed in multiple ways, define it | |
38825 | with a union type containing the useful representations. The | |
38826 | @samp{<union>} element contains one or more @samp{<field>} elements, | |
38827 | each of which has a @var{name} and a @var{type}: | |
38828 | ||
38829 | @smallexample | |
38830 | <union id="@var{id}"> | |
38831 | <field name="@var{name}" type="@var{type}"/> | |
38832 | @dots{} | |
38833 | </union> | |
38834 | @end smallexample | |
38835 | ||
f5dff777 DJ |
38836 | @cindex <struct> |
38837 | If a register's value is composed from several separate values, define | |
38838 | it with a structure type. There are two forms of the @samp{<struct>} | |
38839 | element; a @samp{<struct>} element must either contain only bitfields | |
38840 | or contain no bitfields. If the structure contains only bitfields, | |
38841 | its total size in bytes must be specified, each bitfield must have an | |
38842 | explicit start and end, and bitfields are automatically assigned an | |
38843 | integer type. The field's @var{start} should be less than or | |
38844 | equal to its @var{end}, and zero represents the least significant bit. | |
38845 | ||
38846 | @smallexample | |
38847 | <struct id="@var{id}" size="@var{size}"> | |
38848 | <field name="@var{name}" start="@var{start}" end="@var{end}"/> | |
38849 | @dots{} | |
38850 | </struct> | |
38851 | @end smallexample | |
38852 | ||
38853 | If the structure contains no bitfields, then each field has an | |
38854 | explicit type, and no implicit padding is added. | |
38855 | ||
38856 | @smallexample | |
38857 | <struct id="@var{id}"> | |
38858 | <field name="@var{name}" type="@var{type}"/> | |
38859 | @dots{} | |
38860 | </struct> | |
38861 | @end smallexample | |
38862 | ||
38863 | @cindex <flags> | |
38864 | If a register's value is a series of single-bit flags, define it with | |
38865 | a flags type. The @samp{<flags>} element has an explicit @var{size} | |
38866 | and contains one or more @samp{<field>} elements. Each field has a | |
38867 | @var{name}, a @var{start}, and an @var{end}. Only single-bit flags | |
38868 | are supported. | |
38869 | ||
38870 | @smallexample | |
38871 | <flags id="@var{id}" size="@var{size}"> | |
38872 | <field name="@var{name}" start="@var{start}" end="@var{end}"/> | |
38873 | @dots{} | |
38874 | </flags> | |
38875 | @end smallexample | |
38876 | ||
123dc839 DJ |
38877 | @subsection Registers |
38878 | @cindex <reg> | |
38879 | ||
38880 | Each register is represented as an element with this form: | |
38881 | ||
38882 | @smallexample | |
38883 | <reg name="@var{name}" | |
38884 | bitsize="@var{size}" | |
38885 | @r{[}regnum="@var{num}"@r{]} | |
38886 | @r{[}save-restore="@var{save-restore}"@r{]} | |
38887 | @r{[}type="@var{type}"@r{]} | |
38888 | @r{[}group="@var{group}"@r{]}/> | |
38889 | @end smallexample | |
38890 | ||
38891 | @noindent | |
38892 | The components are as follows: | |
38893 | ||
38894 | @table @var | |
38895 | ||
38896 | @item name | |
38897 | The register's name; it must be unique within the target description. | |
38898 | ||
38899 | @item bitsize | |
38900 | The register's size, in bits. | |
38901 | ||
38902 | @item regnum | |
38903 | The register's number. If omitted, a register's number is one greater | |
38904 | than that of the previous register (either in the current feature or in | |
177b42fe | 38905 | a preceding feature); the first register in the target description |
123dc839 DJ |
38906 | defaults to zero. This register number is used to read or write |
38907 | the register; e.g.@: it is used in the remote @code{p} and @code{P} | |
38908 | packets, and registers appear in the @code{g} and @code{G} packets | |
38909 | in order of increasing register number. | |
38910 | ||
38911 | @item save-restore | |
38912 | Whether the register should be preserved across inferior function | |
38913 | calls; this must be either @code{yes} or @code{no}. The default is | |
38914 | @code{yes}, which is appropriate for most registers except for | |
38915 | some system control registers; this is not related to the target's | |
38916 | ABI. | |
38917 | ||
38918 | @item type | |
697aa1b7 | 38919 | The type of the register. It may be a predefined type, a type |
123dc839 DJ |
38920 | defined in the current feature, or one of the special types @code{int} |
38921 | and @code{float}. @code{int} is an integer type of the correct size | |
38922 | for @var{bitsize}, and @code{float} is a floating point type (in the | |
38923 | architecture's normal floating point format) of the correct size for | |
38924 | @var{bitsize}. The default is @code{int}. | |
38925 | ||
38926 | @item group | |
697aa1b7 | 38927 | The register group to which this register belongs. It must |
123dc839 DJ |
38928 | be either @code{general}, @code{float}, or @code{vector}. If no |
38929 | @var{group} is specified, @value{GDBN} will not display the register | |
38930 | in @code{info registers}. | |
38931 | ||
38932 | @end table | |
38933 | ||
38934 | @node Predefined Target Types | |
38935 | @section Predefined Target Types | |
38936 | @cindex target descriptions, predefined types | |
38937 | ||
38938 | Type definitions in the self-description can build up composite types | |
38939 | from basic building blocks, but can not define fundamental types. Instead, | |
38940 | standard identifiers are provided by @value{GDBN} for the fundamental | |
38941 | types. The currently supported types are: | |
38942 | ||
38943 | @table @code | |
38944 | ||
38945 | @item int8 | |
38946 | @itemx int16 | |
38947 | @itemx int32 | |
38948 | @itemx int64 | |
7cc46491 | 38949 | @itemx int128 |
123dc839 DJ |
38950 | Signed integer types holding the specified number of bits. |
38951 | ||
38952 | @item uint8 | |
38953 | @itemx uint16 | |
38954 | @itemx uint32 | |
38955 | @itemx uint64 | |
7cc46491 | 38956 | @itemx uint128 |
123dc839 DJ |
38957 | Unsigned integer types holding the specified number of bits. |
38958 | ||
38959 | @item code_ptr | |
38960 | @itemx data_ptr | |
38961 | Pointers to unspecified code and data. The program counter and | |
38962 | any dedicated return address register may be marked as code | |
38963 | pointers; printing a code pointer converts it into a symbolic | |
38964 | address. The stack pointer and any dedicated address registers | |
38965 | may be marked as data pointers. | |
38966 | ||
6e3bbd1a PB |
38967 | @item ieee_single |
38968 | Single precision IEEE floating point. | |
38969 | ||
38970 | @item ieee_double | |
38971 | Double precision IEEE floating point. | |
38972 | ||
123dc839 DJ |
38973 | @item arm_fpa_ext |
38974 | The 12-byte extended precision format used by ARM FPA registers. | |
38975 | ||
075b51b7 L |
38976 | @item i387_ext |
38977 | The 10-byte extended precision format used by x87 registers. | |
38978 | ||
38979 | @item i386_eflags | |
38980 | 32bit @sc{eflags} register used by x86. | |
38981 | ||
38982 | @item i386_mxcsr | |
38983 | 32bit @sc{mxcsr} register used by x86. | |
38984 | ||
123dc839 DJ |
38985 | @end table |
38986 | ||
38987 | @node Standard Target Features | |
38988 | @section Standard Target Features | |
38989 | @cindex target descriptions, standard features | |
38990 | ||
38991 | A target description must contain either no registers or all the | |
38992 | target's registers. If the description contains no registers, then | |
38993 | @value{GDBN} will assume a default register layout, selected based on | |
38994 | the architecture. If the description contains any registers, the | |
38995 | default layout will not be used; the standard registers must be | |
38996 | described in the target description, in such a way that @value{GDBN} | |
38997 | can recognize them. | |
38998 | ||
38999 | This is accomplished by giving specific names to feature elements | |
39000 | which contain standard registers. @value{GDBN} will look for features | |
39001 | with those names and verify that they contain the expected registers; | |
39002 | if any known feature is missing required registers, or if any required | |
39003 | feature is missing, @value{GDBN} will reject the target | |
39004 | description. You can add additional registers to any of the | |
39005 | standard features --- @value{GDBN} will display them just as if | |
39006 | they were added to an unrecognized feature. | |
39007 | ||
39008 | This section lists the known features and their expected contents. | |
39009 | Sample XML documents for these features are included in the | |
39010 | @value{GDBN} source tree, in the directory @file{gdb/features}. | |
39011 | ||
39012 | Names recognized by @value{GDBN} should include the name of the | |
39013 | company or organization which selected the name, and the overall | |
39014 | architecture to which the feature applies; so e.g.@: the feature | |
39015 | containing ARM core registers is named @samp{org.gnu.gdb.arm.core}. | |
39016 | ||
ff6f572f DJ |
39017 | The names of registers are not case sensitive for the purpose |
39018 | of recognizing standard features, but @value{GDBN} will only display | |
39019 | registers using the capitalization used in the description. | |
39020 | ||
e9c17194 | 39021 | @menu |
430ed3f0 | 39022 | * AArch64 Features:: |
e9c17194 | 39023 | * ARM Features:: |
3bb8d5c3 | 39024 | * i386 Features:: |
164224e9 | 39025 | * MicroBlaze Features:: |
1e26b4f8 | 39026 | * MIPS Features:: |
e9c17194 | 39027 | * M68K Features:: |
a1217d97 | 39028 | * Nios II Features:: |
1e26b4f8 | 39029 | * PowerPC Features:: |
4ac33720 | 39030 | * S/390 and System z Features:: |
224bbe49 | 39031 | * TIC6x Features:: |
e9c17194 VP |
39032 | @end menu |
39033 | ||
39034 | ||
430ed3f0 MS |
39035 | @node AArch64 Features |
39036 | @subsection AArch64 Features | |
39037 | @cindex target descriptions, AArch64 features | |
39038 | ||
39039 | The @samp{org.gnu.gdb.aarch64.core} feature is required for AArch64 | |
39040 | targets. It should contain registers @samp{x0} through @samp{x30}, | |
39041 | @samp{sp}, @samp{pc}, and @samp{cpsr}. | |
39042 | ||
39043 | The @samp{org.gnu.gdb.aarch64.fpu} feature is optional. If present, | |
39044 | it should contain registers @samp{v0} through @samp{v31}, @samp{fpsr}, | |
39045 | and @samp{fpcr}. | |
39046 | ||
e9c17194 | 39047 | @node ARM Features |
123dc839 DJ |
39048 | @subsection ARM Features |
39049 | @cindex target descriptions, ARM features | |
39050 | ||
9779414d DJ |
39051 | The @samp{org.gnu.gdb.arm.core} feature is required for non-M-profile |
39052 | ARM targets. | |
123dc839 DJ |
39053 | It should contain registers @samp{r0} through @samp{r13}, @samp{sp}, |
39054 | @samp{lr}, @samp{pc}, and @samp{cpsr}. | |
39055 | ||
9779414d DJ |
39056 | For M-profile targets (e.g. Cortex-M3), the @samp{org.gnu.gdb.arm.core} |
39057 | feature is replaced by @samp{org.gnu.gdb.arm.m-profile}. It should contain | |
39058 | registers @samp{r0} through @samp{r13}, @samp{sp}, @samp{lr}, @samp{pc}, | |
39059 | and @samp{xpsr}. | |
39060 | ||
123dc839 DJ |
39061 | The @samp{org.gnu.gdb.arm.fpa} feature is optional. If present, it |
39062 | should contain registers @samp{f0} through @samp{f7} and @samp{fps}. | |
39063 | ||
ff6f572f DJ |
39064 | The @samp{org.gnu.gdb.xscale.iwmmxt} feature is optional. If present, |
39065 | it should contain at least registers @samp{wR0} through @samp{wR15} and | |
39066 | @samp{wCGR0} through @samp{wCGR3}. The @samp{wCID}, @samp{wCon}, | |
39067 | @samp{wCSSF}, and @samp{wCASF} registers are optional. | |
23181151 | 39068 | |
58d6951d DJ |
39069 | The @samp{org.gnu.gdb.arm.vfp} feature is optional. If present, it |
39070 | should contain at least registers @samp{d0} through @samp{d15}. If | |
39071 | they are present, @samp{d16} through @samp{d31} should also be included. | |
39072 | @value{GDBN} will synthesize the single-precision registers from | |
39073 | halves of the double-precision registers. | |
39074 | ||
39075 | The @samp{org.gnu.gdb.arm.neon} feature is optional. It does not | |
39076 | need to contain registers; it instructs @value{GDBN} to display the | |
39077 | VFP double-precision registers as vectors and to synthesize the | |
39078 | quad-precision registers from pairs of double-precision registers. | |
39079 | If this feature is present, @samp{org.gnu.gdb.arm.vfp} must also | |
39080 | be present and include 32 double-precision registers. | |
39081 | ||
3bb8d5c3 L |
39082 | @node i386 Features |
39083 | @subsection i386 Features | |
39084 | @cindex target descriptions, i386 features | |
39085 | ||
39086 | The @samp{org.gnu.gdb.i386.core} feature is required for i386/amd64 | |
39087 | targets. It should describe the following registers: | |
39088 | ||
39089 | @itemize @minus | |
39090 | @item | |
39091 | @samp{eax} through @samp{edi} plus @samp{eip} for i386 | |
39092 | @item | |
39093 | @samp{rax} through @samp{r15} plus @samp{rip} for amd64 | |
39094 | @item | |
39095 | @samp{eflags}, @samp{cs}, @samp{ss}, @samp{ds}, @samp{es}, | |
39096 | @samp{fs}, @samp{gs} | |
39097 | @item | |
39098 | @samp{st0} through @samp{st7} | |
39099 | @item | |
39100 | @samp{fctrl}, @samp{fstat}, @samp{ftag}, @samp{fiseg}, @samp{fioff}, | |
39101 | @samp{foseg}, @samp{fooff} and @samp{fop} | |
39102 | @end itemize | |
39103 | ||
39104 | The register sets may be different, depending on the target. | |
39105 | ||
3a13a53b | 39106 | The @samp{org.gnu.gdb.i386.sse} feature is optional. It should |
3bb8d5c3 L |
39107 | describe registers: |
39108 | ||
39109 | @itemize @minus | |
39110 | @item | |
39111 | @samp{xmm0} through @samp{xmm7} for i386 | |
39112 | @item | |
39113 | @samp{xmm0} through @samp{xmm15} for amd64 | |
39114 | @item | |
39115 | @samp{mxcsr} | |
39116 | @end itemize | |
39117 | ||
3a13a53b L |
39118 | The @samp{org.gnu.gdb.i386.avx} feature is optional and requires the |
39119 | @samp{org.gnu.gdb.i386.sse} feature. It should | |
f68eb612 L |
39120 | describe the upper 128 bits of @sc{ymm} registers: |
39121 | ||
39122 | @itemize @minus | |
39123 | @item | |
39124 | @samp{ymm0h} through @samp{ymm7h} for i386 | |
39125 | @item | |
39126 | @samp{ymm0h} through @samp{ymm15h} for amd64 | |
f68eb612 L |
39127 | @end itemize |
39128 | ||
ca8941bb WT |
39129 | The @samp{org.gnu.gdb.i386.mpx} is an optional feature representing Intel(R) |
39130 | Memory Protection Extension (MPX). It should describe the following registers: | |
39131 | ||
39132 | @itemize @minus | |
39133 | @item | |
39134 | @samp{bnd0raw} through @samp{bnd3raw} for i386 and amd64. | |
39135 | @item | |
39136 | @samp{bndcfgu} and @samp{bndstatus} for i386 and amd64. | |
39137 | @end itemize | |
39138 | ||
3bb8d5c3 L |
39139 | The @samp{org.gnu.gdb.i386.linux} feature is optional. It should |
39140 | describe a single register, @samp{orig_eax}. | |
39141 | ||
01f9f808 MS |
39142 | The @samp{org.gnu.gdb.i386.avx512} feature is optional and requires the |
39143 | @samp{org.gnu.gdb.i386.avx} feature. It should | |
39144 | describe additional @sc{xmm} registers: | |
39145 | ||
39146 | @itemize @minus | |
39147 | @item | |
39148 | @samp{xmm16h} through @samp{xmm31h}, only valid for amd64. | |
39149 | @end itemize | |
39150 | ||
39151 | It should describe the upper 128 bits of additional @sc{ymm} registers: | |
39152 | ||
39153 | @itemize @minus | |
39154 | @item | |
39155 | @samp{ymm16h} through @samp{ymm31h}, only valid for amd64. | |
39156 | @end itemize | |
39157 | ||
39158 | It should | |
39159 | describe the upper 256 bits of @sc{zmm} registers: | |
39160 | ||
39161 | @itemize @minus | |
39162 | @item | |
39163 | @samp{zmm0h} through @samp{zmm7h} for i386. | |
39164 | @item | |
39165 | @samp{zmm0h} through @samp{zmm15h} for amd64. | |
39166 | @end itemize | |
39167 | ||
39168 | It should | |
39169 | describe the additional @sc{zmm} registers: | |
39170 | ||
39171 | @itemize @minus | |
39172 | @item | |
39173 | @samp{zmm16h} through @samp{zmm31h}, only valid for amd64. | |
39174 | @end itemize | |
39175 | ||
164224e9 ME |
39176 | @node MicroBlaze Features |
39177 | @subsection MicroBlaze Features | |
39178 | @cindex target descriptions, MicroBlaze features | |
39179 | ||
39180 | The @samp{org.gnu.gdb.microblaze.core} feature is required for MicroBlaze | |
39181 | targets. It should contain registers @samp{r0} through @samp{r31}, | |
39182 | @samp{rpc}, @samp{rmsr}, @samp{rear}, @samp{resr}, @samp{rfsr}, @samp{rbtr}, | |
39183 | @samp{rpvr}, @samp{rpvr1} through @samp{rpvr11}, @samp{redr}, @samp{rpid}, | |
39184 | @samp{rzpr}, @samp{rtlbx}, @samp{rtlbsx}, @samp{rtlblo}, and @samp{rtlbhi}. | |
39185 | ||
39186 | The @samp{org.gnu.gdb.microblaze.stack-protect} feature is optional. | |
39187 | If present, it should contain registers @samp{rshr} and @samp{rslr} | |
39188 | ||
1e26b4f8 | 39189 | @node MIPS Features |
eb17f351 EZ |
39190 | @subsection @acronym{MIPS} Features |
39191 | @cindex target descriptions, @acronym{MIPS} features | |
f8b73d13 | 39192 | |
eb17f351 | 39193 | The @samp{org.gnu.gdb.mips.cpu} feature is required for @acronym{MIPS} targets. |
f8b73d13 DJ |
39194 | It should contain registers @samp{r0} through @samp{r31}, @samp{lo}, |
39195 | @samp{hi}, and @samp{pc}. They may be 32-bit or 64-bit depending | |
39196 | on the target. | |
39197 | ||
39198 | The @samp{org.gnu.gdb.mips.cp0} feature is also required. It should | |
39199 | contain at least the @samp{status}, @samp{badvaddr}, and @samp{cause} | |
39200 | registers. They may be 32-bit or 64-bit depending on the target. | |
39201 | ||
39202 | The @samp{org.gnu.gdb.mips.fpu} feature is currently required, though | |
39203 | it may be optional in a future version of @value{GDBN}. It should | |
39204 | contain registers @samp{f0} through @samp{f31}, @samp{fcsr}, and | |
39205 | @samp{fir}. They may be 32-bit or 64-bit depending on the target. | |
39206 | ||
1faeff08 MR |
39207 | The @samp{org.gnu.gdb.mips.dsp} feature is optional. It should |
39208 | contain registers @samp{hi1} through @samp{hi3}, @samp{lo1} through | |
39209 | @samp{lo3}, and @samp{dspctl}. The @samp{dspctl} register should | |
39210 | be 32-bit and the rest may be 32-bit or 64-bit depending on the target. | |
39211 | ||
822b6570 DJ |
39212 | The @samp{org.gnu.gdb.mips.linux} feature is optional. It should |
39213 | contain a single register, @samp{restart}, which is used by the | |
39214 | Linux kernel to control restartable syscalls. | |
39215 | ||
e9c17194 VP |
39216 | @node M68K Features |
39217 | @subsection M68K Features | |
39218 | @cindex target descriptions, M68K features | |
39219 | ||
39220 | @table @code | |
39221 | @item @samp{org.gnu.gdb.m68k.core} | |
39222 | @itemx @samp{org.gnu.gdb.coldfire.core} | |
39223 | @itemx @samp{org.gnu.gdb.fido.core} | |
39224 | One of those features must be always present. | |
249e1128 | 39225 | The feature that is present determines which flavor of m68k is |
e9c17194 VP |
39226 | used. The feature that is present should contain registers |
39227 | @samp{d0} through @samp{d7}, @samp{a0} through @samp{a5}, @samp{fp}, | |
39228 | @samp{sp}, @samp{ps} and @samp{pc}. | |
39229 | ||
39230 | @item @samp{org.gnu.gdb.coldfire.fp} | |
39231 | This feature is optional. If present, it should contain registers | |
39232 | @samp{fp0} through @samp{fp7}, @samp{fpcontrol}, @samp{fpstatus} and | |
39233 | @samp{fpiaddr}. | |
39234 | @end table | |
39235 | ||
a1217d97 SL |
39236 | @node Nios II Features |
39237 | @subsection Nios II Features | |
39238 | @cindex target descriptions, Nios II features | |
39239 | ||
39240 | The @samp{org.gnu.gdb.nios2.cpu} feature is required for Nios II | |
39241 | targets. It should contain the 32 core registers (@samp{zero}, | |
39242 | @samp{at}, @samp{r2} through @samp{r23}, @samp{et} through @samp{ra}), | |
39243 | @samp{pc}, and the 16 control registers (@samp{status} through | |
39244 | @samp{mpuacc}). | |
39245 | ||
1e26b4f8 | 39246 | @node PowerPC Features |
7cc46491 DJ |
39247 | @subsection PowerPC Features |
39248 | @cindex target descriptions, PowerPC features | |
39249 | ||
39250 | The @samp{org.gnu.gdb.power.core} feature is required for PowerPC | |
39251 | targets. It should contain registers @samp{r0} through @samp{r31}, | |
39252 | @samp{pc}, @samp{msr}, @samp{cr}, @samp{lr}, @samp{ctr}, and | |
39253 | @samp{xer}. They may be 32-bit or 64-bit depending on the target. | |
39254 | ||
39255 | The @samp{org.gnu.gdb.power.fpu} feature is optional. It should | |
39256 | contain registers @samp{f0} through @samp{f31} and @samp{fpscr}. | |
39257 | ||
39258 | The @samp{org.gnu.gdb.power.altivec} feature is optional. It should | |
39259 | contain registers @samp{vr0} through @samp{vr31}, @samp{vscr}, | |
39260 | and @samp{vrsave}. | |
39261 | ||
677c5bb1 LM |
39262 | The @samp{org.gnu.gdb.power.vsx} feature is optional. It should |
39263 | contain registers @samp{vs0h} through @samp{vs31h}. @value{GDBN} | |
39264 | will combine these registers with the floating point registers | |
39265 | (@samp{f0} through @samp{f31}) and the altivec registers (@samp{vr0} | |
aeac0ff9 | 39266 | through @samp{vr31}) to present the 128-bit wide registers @samp{vs0} |
677c5bb1 LM |
39267 | through @samp{vs63}, the set of vector registers for POWER7. |
39268 | ||
7cc46491 DJ |
39269 | The @samp{org.gnu.gdb.power.spe} feature is optional. It should |
39270 | contain registers @samp{ev0h} through @samp{ev31h}, @samp{acc}, and | |
39271 | @samp{spefscr}. SPE targets should provide 32-bit registers in | |
39272 | @samp{org.gnu.gdb.power.core} and provide the upper halves in | |
39273 | @samp{ev0h} through @samp{ev31h}. @value{GDBN} will combine | |
39274 | these to present registers @samp{ev0} through @samp{ev31} to the | |
39275 | user. | |
39276 | ||
4ac33720 UW |
39277 | @node S/390 and System z Features |
39278 | @subsection S/390 and System z Features | |
39279 | @cindex target descriptions, S/390 features | |
39280 | @cindex target descriptions, System z features | |
39281 | ||
39282 | The @samp{org.gnu.gdb.s390.core} feature is required for S/390 and | |
39283 | System z targets. It should contain the PSW and the 16 general | |
39284 | registers. In particular, System z targets should provide the 64-bit | |
39285 | registers @samp{pswm}, @samp{pswa}, and @samp{r0} through @samp{r15}. | |
39286 | S/390 targets should provide the 32-bit versions of these registers. | |
39287 | A System z target that runs in 31-bit addressing mode should provide | |
39288 | 32-bit versions of @samp{pswm} and @samp{pswa}, as well as the general | |
39289 | register's upper halves @samp{r0h} through @samp{r15h}, and their | |
39290 | lower halves @samp{r0l} through @samp{r15l}. | |
39291 | ||
39292 | The @samp{org.gnu.gdb.s390.fpr} feature is required. It should | |
39293 | contain the 64-bit registers @samp{f0} through @samp{f15}, and | |
39294 | @samp{fpc}. | |
39295 | ||
39296 | The @samp{org.gnu.gdb.s390.acr} feature is required. It should | |
39297 | contain the 32-bit registers @samp{acr0} through @samp{acr15}. | |
39298 | ||
39299 | The @samp{org.gnu.gdb.s390.linux} feature is optional. It should | |
39300 | contain the register @samp{orig_r2}, which is 64-bit wide on System z | |
39301 | targets and 32-bit otherwise. In addition, the feature may contain | |
39302 | the @samp{last_break} register, whose width depends on the addressing | |
39303 | mode, as well as the @samp{system_call} register, which is always | |
39304 | 32-bit wide. | |
39305 | ||
39306 | The @samp{org.gnu.gdb.s390.tdb} feature is optional. It should | |
39307 | contain the 64-bit registers @samp{tdb0}, @samp{tac}, @samp{tct}, | |
39308 | @samp{atia}, and @samp{tr0} through @samp{tr15}. | |
39309 | ||
224bbe49 YQ |
39310 | @node TIC6x Features |
39311 | @subsection TMS320C6x Features | |
39312 | @cindex target descriptions, TIC6x features | |
39313 | @cindex target descriptions, TMS320C6x features | |
39314 | The @samp{org.gnu.gdb.tic6x.core} feature is required for TMS320C6x | |
39315 | targets. It should contain registers @samp{A0} through @samp{A15}, | |
39316 | registers @samp{B0} through @samp{B15}, @samp{CSR} and @samp{PC}. | |
39317 | ||
39318 | The @samp{org.gnu.gdb.tic6x.gp} feature is optional. It should | |
39319 | contain registers @samp{A16} through @samp{A31} and @samp{B16} | |
39320 | through @samp{B31}. | |
39321 | ||
39322 | The @samp{org.gnu.gdb.tic6x.c6xp} feature is optional. It should | |
39323 | contain registers @samp{TSR}, @samp{ILC} and @samp{RILC}. | |
39324 | ||
07e059b5 VP |
39325 | @node Operating System Information |
39326 | @appendix Operating System Information | |
39327 | @cindex operating system information | |
39328 | ||
39329 | @menu | |
39330 | * Process list:: | |
39331 | @end menu | |
39332 | ||
39333 | Users of @value{GDBN} often wish to obtain information about the state of | |
39334 | the operating system running on the target---for example the list of | |
39335 | processes, or the list of open files. This section describes the | |
39336 | mechanism that makes it possible. This mechanism is similar to the | |
39337 | target features mechanism (@pxref{Target Descriptions}), but focuses | |
39338 | on a different aspect of target. | |
39339 | ||
39340 | Operating system information is retrived from the target via the | |
39341 | remote protocol, using @samp{qXfer} requests (@pxref{qXfer osdata | |
39342 | read}). The object name in the request should be @samp{osdata}, and | |
39343 | the @var{annex} identifies the data to be fetched. | |
39344 | ||
39345 | @node Process list | |
39346 | @appendixsection Process list | |
39347 | @cindex operating system information, process list | |
39348 | ||
39349 | When requesting the process list, the @var{annex} field in the | |
39350 | @samp{qXfer} request should be @samp{processes}. The returned data is | |
39351 | an XML document. The formal syntax of this document is defined in | |
39352 | @file{gdb/features/osdata.dtd}. | |
39353 | ||
39354 | An example document is: | |
39355 | ||
39356 | @smallexample | |
39357 | <?xml version="1.0"?> | |
39358 | <!DOCTYPE target SYSTEM "osdata.dtd"> | |
39359 | <osdata type="processes"> | |
39360 | <item> | |
39361 | <column name="pid">1</column> | |
39362 | <column name="user">root</column> | |
39363 | <column name="command">/sbin/init</column> | |
dc146f7c | 39364 | <column name="cores">1,2,3</column> |
07e059b5 VP |
39365 | </item> |
39366 | </osdata> | |
39367 | @end smallexample | |
39368 | ||
39369 | Each item should include a column whose name is @samp{pid}. The value | |
39370 | of that column should identify the process on the target. The | |
39371 | @samp{user} and @samp{command} columns are optional, and will be | |
dc146f7c VP |
39372 | displayed by @value{GDBN}. The @samp{cores} column, if present, |
39373 | should contain a comma-separated list of cores that this process | |
39374 | is running on. Target may provide additional columns, | |
07e059b5 VP |
39375 | which @value{GDBN} currently ignores. |
39376 | ||
05c8c3f5 TT |
39377 | @node Trace File Format |
39378 | @appendix Trace File Format | |
39379 | @cindex trace file format | |
39380 | ||
39381 | The trace file comes in three parts: a header, a textual description | |
39382 | section, and a trace frame section with binary data. | |
39383 | ||
39384 | The header has the form @code{\x7fTRACE0\n}. The first byte is | |
39385 | @code{0x7f} so as to indicate that the file contains binary data, | |
39386 | while the @code{0} is a version number that may have different values | |
39387 | in the future. | |
39388 | ||
39389 | The description section consists of multiple lines of @sc{ascii} text | |
39390 | separated by newline characters (@code{0xa}). The lines may include a | |
39391 | variety of optional descriptive or context-setting information, such | |
39392 | as tracepoint definitions or register set size. @value{GDBN} will | |
39393 | ignore any line that it does not recognize. An empty line marks the end | |
39394 | of this section. | |
39395 | ||
39396 | @c FIXME add some specific types of data | |
39397 | ||
39398 | The trace frame section consists of a number of consecutive frames. | |
39399 | Each frame begins with a two-byte tracepoint number, followed by a | |
39400 | four-byte size giving the amount of data in the frame. The data in | |
39401 | the frame consists of a number of blocks, each introduced by a | |
39402 | character indicating its type (at least register, memory, and trace | |
39403 | state variable). The data in this section is raw binary, not a | |
39404 | hexadecimal or other encoding; its endianness matches the target's | |
39405 | endianness. | |
39406 | ||
39407 | @c FIXME bi-arch may require endianness/arch info in description section | |
39408 | ||
39409 | @table @code | |
39410 | @item R @var{bytes} | |
39411 | Register block. The number and ordering of bytes matches that of a | |
39412 | @code{g} packet in the remote protocol. Note that these are the | |
39413 | actual bytes, in target order and @value{GDBN} register order, not a | |
39414 | hexadecimal encoding. | |
39415 | ||
39416 | @item M @var{address} @var{length} @var{bytes}... | |
39417 | Memory block. This is a contiguous block of memory, at the 8-byte | |
39418 | address @var{address}, with a 2-byte length @var{length}, followed by | |
39419 | @var{length} bytes. | |
39420 | ||
39421 | @item V @var{number} @var{value} | |
39422 | Trace state variable block. This records the 8-byte signed value | |
39423 | @var{value} of trace state variable numbered @var{number}. | |
39424 | ||
39425 | @end table | |
39426 | ||
39427 | Future enhancements of the trace file format may include additional types | |
39428 | of blocks. | |
39429 | ||
90476074 TT |
39430 | @node Index Section Format |
39431 | @appendix @code{.gdb_index} section format | |
39432 | @cindex .gdb_index section format | |
39433 | @cindex index section format | |
39434 | ||
39435 | This section documents the index section that is created by @code{save | |
39436 | gdb-index} (@pxref{Index Files}). The index section is | |
39437 | DWARF-specific; some knowledge of DWARF is assumed in this | |
39438 | description. | |
39439 | ||
39440 | The mapped index file format is designed to be directly | |
39441 | @code{mmap}able on any architecture. In most cases, a datum is | |
39442 | represented using a little-endian 32-bit integer value, called an | |
39443 | @code{offset_type}. Big endian machines must byte-swap the values | |
39444 | before using them. Exceptions to this rule are noted. The data is | |
39445 | laid out such that alignment is always respected. | |
39446 | ||
39447 | A mapped index consists of several areas, laid out in order. | |
39448 | ||
39449 | @enumerate | |
39450 | @item | |
39451 | The file header. This is a sequence of values, of @code{offset_type} | |
39452 | unless otherwise noted: | |
39453 | ||
39454 | @enumerate | |
39455 | @item | |
796a7ff8 | 39456 | The version number, currently 8. Versions 1, 2 and 3 are obsolete. |
481860b3 | 39457 | Version 4 uses a different hashing function from versions 5 and 6. |
b6ba681c TT |
39458 | Version 6 includes symbols for inlined functions, whereas versions 4 |
39459 | and 5 do not. Version 7 adds attributes to the CU indices in the | |
796a7ff8 DE |
39460 | symbol table. Version 8 specifies that symbols from DWARF type units |
39461 | (@samp{DW_TAG_type_unit}) refer to the type unit's symbol table and not the | |
39462 | compilation unit (@samp{DW_TAG_comp_unit}) using the type. | |
39463 | ||
39464 | @value{GDBN} will only read version 4, 5, or 6 indices | |
e615022a | 39465 | by specifying @code{set use-deprecated-index-sections on}. |
796a7ff8 DE |
39466 | GDB has a workaround for potentially broken version 7 indices so it is |
39467 | currently not flagged as deprecated. | |
90476074 TT |
39468 | |
39469 | @item | |
39470 | The offset, from the start of the file, of the CU list. | |
39471 | ||
39472 | @item | |
39473 | The offset, from the start of the file, of the types CU list. Note | |
39474 | that this area can be empty, in which case this offset will be equal | |
39475 | to the next offset. | |
39476 | ||
39477 | @item | |
39478 | The offset, from the start of the file, of the address area. | |
39479 | ||
39480 | @item | |
39481 | The offset, from the start of the file, of the symbol table. | |
39482 | ||
39483 | @item | |
39484 | The offset, from the start of the file, of the constant pool. | |
39485 | @end enumerate | |
39486 | ||
39487 | @item | |
39488 | The CU list. This is a sequence of pairs of 64-bit little-endian | |
39489 | values, sorted by the CU offset. The first element in each pair is | |
39490 | the offset of a CU in the @code{.debug_info} section. The second | |
39491 | element in each pair is the length of that CU. References to a CU | |
39492 | elsewhere in the map are done using a CU index, which is just the | |
39493 | 0-based index into this table. Note that if there are type CUs, then | |
39494 | conceptually CUs and type CUs form a single list for the purposes of | |
39495 | CU indices. | |
39496 | ||
39497 | @item | |
39498 | The types CU list. This is a sequence of triplets of 64-bit | |
39499 | little-endian values. In a triplet, the first value is the CU offset, | |
39500 | the second value is the type offset in the CU, and the third value is | |
39501 | the type signature. The types CU list is not sorted. | |
39502 | ||
39503 | @item | |
39504 | The address area. The address area consists of a sequence of address | |
39505 | entries. Each address entry has three elements: | |
39506 | ||
39507 | @enumerate | |
39508 | @item | |
39509 | The low address. This is a 64-bit little-endian value. | |
39510 | ||
39511 | @item | |
39512 | The high address. This is a 64-bit little-endian value. Like | |
39513 | @code{DW_AT_high_pc}, the value is one byte beyond the end. | |
39514 | ||
39515 | @item | |
39516 | The CU index. This is an @code{offset_type} value. | |
39517 | @end enumerate | |
39518 | ||
39519 | @item | |
39520 | The symbol table. This is an open-addressed hash table. The size of | |
39521 | the hash table is always a power of 2. | |
39522 | ||
39523 | Each slot in the hash table consists of a pair of @code{offset_type} | |
39524 | values. The first value is the offset of the symbol's name in the | |
39525 | constant pool. The second value is the offset of the CU vector in the | |
39526 | constant pool. | |
39527 | ||
39528 | If both values are 0, then this slot in the hash table is empty. This | |
39529 | is ok because while 0 is a valid constant pool index, it cannot be a | |
39530 | valid index for both a string and a CU vector. | |
39531 | ||
39532 | The hash value for a table entry is computed by applying an | |
39533 | iterative hash function to the symbol's name. Starting with an | |
39534 | initial value of @code{r = 0}, each (unsigned) character @samp{c} in | |
559a7a62 JK |
39535 | the string is incorporated into the hash using the formula depending on the |
39536 | index version: | |
39537 | ||
39538 | @table @asis | |
39539 | @item Version 4 | |
39540 | The formula is @code{r = r * 67 + c - 113}. | |
39541 | ||
156942c7 | 39542 | @item Versions 5 to 7 |
559a7a62 JK |
39543 | The formula is @code{r = r * 67 + tolower (c) - 113}. |
39544 | @end table | |
39545 | ||
39546 | The terminating @samp{\0} is not incorporated into the hash. | |
90476074 TT |
39547 | |
39548 | The step size used in the hash table is computed via | |
39549 | @code{((hash * 17) & (size - 1)) | 1}, where @samp{hash} is the hash | |
39550 | value, and @samp{size} is the size of the hash table. The step size | |
39551 | is used to find the next candidate slot when handling a hash | |
39552 | collision. | |
39553 | ||
39554 | The names of C@t{++} symbols in the hash table are canonicalized. We | |
39555 | don't currently have a simple description of the canonicalization | |
39556 | algorithm; if you intend to create new index sections, you must read | |
39557 | the code. | |
39558 | ||
39559 | @item | |
39560 | The constant pool. This is simply a bunch of bytes. It is organized | |
39561 | so that alignment is correct: CU vectors are stored first, followed by | |
39562 | strings. | |
39563 | ||
39564 | A CU vector in the constant pool is a sequence of @code{offset_type} | |
39565 | values. The first value is the number of CU indices in the vector. | |
156942c7 DE |
39566 | Each subsequent value is the index and symbol attributes of a CU in |
39567 | the CU list. This element in the hash table is used to indicate which | |
39568 | CUs define the symbol and how the symbol is used. | |
39569 | See below for the format of each CU index+attributes entry. | |
90476074 TT |
39570 | |
39571 | A string in the constant pool is zero-terminated. | |
39572 | @end enumerate | |
39573 | ||
156942c7 DE |
39574 | Attributes were added to CU index values in @code{.gdb_index} version 7. |
39575 | If a symbol has multiple uses within a CU then there is one | |
39576 | CU index+attributes value for each use. | |
39577 | ||
39578 | The format of each CU index+attributes entry is as follows | |
39579 | (bit 0 = LSB): | |
39580 | ||
39581 | @table @asis | |
39582 | ||
39583 | @item Bits 0-23 | |
39584 | This is the index of the CU in the CU list. | |
39585 | @item Bits 24-27 | |
39586 | These bits are reserved for future purposes and must be zero. | |
39587 | @item Bits 28-30 | |
39588 | The kind of the symbol in the CU. | |
39589 | ||
39590 | @table @asis | |
39591 | @item 0 | |
39592 | This value is reserved and should not be used. | |
39593 | By reserving zero the full @code{offset_type} value is backwards compatible | |
39594 | with previous versions of the index. | |
39595 | @item 1 | |
39596 | The symbol is a type. | |
39597 | @item 2 | |
39598 | The symbol is a variable or an enum value. | |
39599 | @item 3 | |
39600 | The symbol is a function. | |
39601 | @item 4 | |
39602 | Any other kind of symbol. | |
39603 | @item 5,6,7 | |
39604 | These values are reserved. | |
39605 | @end table | |
39606 | ||
39607 | @item Bit 31 | |
39608 | This bit is zero if the value is global and one if it is static. | |
39609 | ||
39610 | The determination of whether a symbol is global or static is complicated. | |
39611 | The authorative reference is the file @file{dwarf2read.c} in | |
39612 | @value{GDBN} sources. | |
39613 | ||
39614 | @end table | |
39615 | ||
39616 | This pseudo-code describes the computation of a symbol's kind and | |
39617 | global/static attributes in the index. | |
39618 | ||
39619 | @smallexample | |
39620 | is_external = get_attribute (die, DW_AT_external); | |
39621 | language = get_attribute (cu_die, DW_AT_language); | |
39622 | switch (die->tag) | |
39623 | @{ | |
39624 | case DW_TAG_typedef: | |
39625 | case DW_TAG_base_type: | |
39626 | case DW_TAG_subrange_type: | |
39627 | kind = TYPE; | |
39628 | is_static = 1; | |
39629 | break; | |
39630 | case DW_TAG_enumerator: | |
39631 | kind = VARIABLE; | |
39632 | is_static = (language != CPLUS && language != JAVA); | |
39633 | break; | |
39634 | case DW_TAG_subprogram: | |
39635 | kind = FUNCTION; | |
39636 | is_static = ! (is_external || language == ADA); | |
39637 | break; | |
39638 | case DW_TAG_constant: | |
39639 | kind = VARIABLE; | |
39640 | is_static = ! is_external; | |
39641 | break; | |
39642 | case DW_TAG_variable: | |
39643 | kind = VARIABLE; | |
39644 | is_static = ! is_external; | |
39645 | break; | |
39646 | case DW_TAG_namespace: | |
39647 | kind = TYPE; | |
39648 | is_static = 0; | |
39649 | break; | |
39650 | case DW_TAG_class_type: | |
39651 | case DW_TAG_interface_type: | |
39652 | case DW_TAG_structure_type: | |
39653 | case DW_TAG_union_type: | |
39654 | case DW_TAG_enumeration_type: | |
39655 | kind = TYPE; | |
39656 | is_static = (language != CPLUS && language != JAVA); | |
39657 | break; | |
39658 | default: | |
39659 | assert (0); | |
39660 | @} | |
39661 | @end smallexample | |
39662 | ||
43662968 JK |
39663 | @node Man Pages |
39664 | @appendix Manual pages | |
39665 | @cindex Man pages | |
39666 | ||
39667 | @menu | |
39668 | * gdb man:: The GNU Debugger man page | |
39669 | * gdbserver man:: Remote Server for the GNU Debugger man page | |
b292c783 | 39670 | * gcore man:: Generate a core file of a running program |
43662968 JK |
39671 | * gdbinit man:: gdbinit scripts |
39672 | @end menu | |
39673 | ||
39674 | @node gdb man | |
39675 | @heading gdb man | |
39676 | ||
39677 | @c man title gdb The GNU Debugger | |
39678 | ||
39679 | @c man begin SYNOPSIS gdb | |
39680 | gdb [@option{-help}] [@option{-nh}] [@option{-nx}] [@option{-q}] | |
39681 | [@option{-batch}] [@option{-cd=}@var{dir}] [@option{-f}] | |
39682 | [@option{-b}@w{ }@var{bps}] | |
39683 | [@option{-tty=}@var{dev}] [@option{-s} @var{symfile}] | |
39684 | [@option{-e}@w{ }@var{prog}] [@option{-se}@w{ }@var{prog}] | |
906ccdf0 JK |
39685 | [@option{-c}@w{ }@var{core}] [@option{-p}@w{ }@var{procID}] |
39686 | [@option{-x}@w{ }@var{cmds}] [@option{-d}@w{ }@var{dir}] | |
39687 | [@var{prog}|@var{prog} @var{procID}|@var{prog} @var{core}] | |
43662968 JK |
39688 | @c man end |
39689 | ||
39690 | @c man begin DESCRIPTION gdb | |
39691 | The purpose of a debugger such as @value{GDBN} is to allow you to see what is | |
39692 | going on ``inside'' another program while it executes -- or what another | |
39693 | program was doing at the moment it crashed. | |
39694 | ||
39695 | @value{GDBN} can do four main kinds of things (plus other things in support of | |
39696 | these) to help you catch bugs in the act: | |
39697 | ||
39698 | @itemize @bullet | |
39699 | @item | |
39700 | Start your program, specifying anything that might affect its behavior. | |
39701 | ||
39702 | @item | |
39703 | Make your program stop on specified conditions. | |
39704 | ||
39705 | @item | |
39706 | Examine what has happened, when your program has stopped. | |
39707 | ||
39708 | @item | |
39709 | Change things in your program, so you can experiment with correcting the | |
39710 | effects of one bug and go on to learn about another. | |
39711 | @end itemize | |
39712 | ||
906ccdf0 JK |
39713 | You can use @value{GDBN} to debug programs written in C, C@t{++}, Fortran and |
39714 | Modula-2. | |
43662968 JK |
39715 | |
39716 | @value{GDBN} is invoked with the shell command @code{gdb}. Once started, it reads | |
39717 | commands from the terminal until you tell it to exit with the @value{GDBN} | |
39718 | command @code{quit}. You can get online help from @value{GDBN} itself | |
39719 | by using the command @code{help}. | |
39720 | ||
39721 | You can run @code{gdb} with no arguments or options; but the most | |
39722 | usual way to start @value{GDBN} is with one argument or two, specifying an | |
39723 | executable program as the argument: | |
39724 | ||
39725 | @smallexample | |
39726 | gdb program | |
39727 | @end smallexample | |
39728 | ||
39729 | You can also start with both an executable program and a core file specified: | |
39730 | ||
39731 | @smallexample | |
39732 | gdb program core | |
39733 | @end smallexample | |
39734 | ||
39735 | You can, instead, specify a process ID as a second argument, if you want | |
39736 | to debug a running process: | |
39737 | ||
39738 | @smallexample | |
39739 | gdb program 1234 | |
906ccdf0 | 39740 | gdb -p 1234 |
43662968 JK |
39741 | @end smallexample |
39742 | ||
39743 | @noindent | |
39744 | would attach @value{GDBN} to process @code{1234} (unless you also have a file | |
39745 | named @file{1234}; @value{GDBN} does check for a core file first). | |
906ccdf0 | 39746 | With option @option{-p} you can omit the @var{program} filename. |
43662968 JK |
39747 | |
39748 | Here are some of the most frequently needed @value{GDBN} commands: | |
39749 | ||
39750 | @c pod2man highlights the right hand side of the @item lines. | |
39751 | @table @env | |
39752 | @item break [@var{file}:]@var{functiop} | |
39753 | Set a breakpoint at @var{function} (in @var{file}). | |
39754 | ||
39755 | @item run [@var{arglist}] | |
39756 | Start your program (with @var{arglist}, if specified). | |
39757 | ||
39758 | @item bt | |
39759 | Backtrace: display the program stack. | |
39760 | ||
39761 | @item print @var{expr} | |
39762 | Display the value of an expression. | |
39763 | ||
39764 | @item c | |
39765 | Continue running your program (after stopping, e.g. at a breakpoint). | |
39766 | ||
39767 | @item next | |
39768 | Execute next program line (after stopping); step @emph{over} any | |
39769 | function calls in the line. | |
39770 | ||
39771 | @item edit [@var{file}:]@var{function} | |
39772 | look at the program line where it is presently stopped. | |
39773 | ||
39774 | @item list [@var{file}:]@var{function} | |
39775 | type the text of the program in the vicinity of where it is presently stopped. | |
39776 | ||
39777 | @item step | |
39778 | Execute next program line (after stopping); step @emph{into} any | |
39779 | function calls in the line. | |
39780 | ||
39781 | @item help [@var{name}] | |
39782 | Show information about @value{GDBN} command @var{name}, or general information | |
39783 | about using @value{GDBN}. | |
39784 | ||
39785 | @item quit | |
39786 | Exit from @value{GDBN}. | |
39787 | @end table | |
39788 | ||
39789 | @ifset man | |
39790 | For full details on @value{GDBN}, | |
39791 | see @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
39792 | by Richard M. Stallman and Roland H. Pesch. The same text is available online | |
39793 | as the @code{gdb} entry in the @code{info} program. | |
39794 | @end ifset | |
39795 | @c man end | |
39796 | ||
39797 | @c man begin OPTIONS gdb | |
39798 | Any arguments other than options specify an executable | |
39799 | file and core file (or process ID); that is, the first argument | |
39800 | encountered with no | |
39801 | associated option flag is equivalent to a @option{-se} option, and the second, | |
39802 | if any, is equivalent to a @option{-c} option if it's the name of a file. | |
39803 | Many options have | |
39804 | both long and short forms; both are shown here. The long forms are also | |
39805 | recognized if you truncate them, so long as enough of the option is | |
39806 | present to be unambiguous. (If you prefer, you can flag option | |
39807 | arguments with @option{+} rather than @option{-}, though we illustrate the | |
39808 | more usual convention.) | |
39809 | ||
39810 | All the options and command line arguments you give are processed | |
39811 | in sequential order. The order makes a difference when the @option{-x} | |
39812 | option is used. | |
39813 | ||
39814 | @table @env | |
39815 | @item -help | |
39816 | @itemx -h | |
39817 | List all options, with brief explanations. | |
39818 | ||
39819 | @item -symbols=@var{file} | |
39820 | @itemx -s @var{file} | |
39821 | Read symbol table from file @var{file}. | |
39822 | ||
39823 | @item -write | |
39824 | Enable writing into executable and core files. | |
39825 | ||
39826 | @item -exec=@var{file} | |
39827 | @itemx -e @var{file} | |
39828 | Use file @var{file} as the executable file to execute when | |
39829 | appropriate, and for examining pure data in conjunction with a core | |
39830 | dump. | |
39831 | ||
39832 | @item -se=@var{file} | |
39833 | Read symbol table from file @var{file} and use it as the executable | |
39834 | file. | |
39835 | ||
39836 | @item -core=@var{file} | |
39837 | @itemx -c @var{file} | |
39838 | Use file @var{file} as a core dump to examine. | |
39839 | ||
39840 | @item -command=@var{file} | |
39841 | @itemx -x @var{file} | |
39842 | Execute @value{GDBN} commands from file @var{file}. | |
39843 | ||
39844 | @item -ex @var{command} | |
39845 | Execute given @value{GDBN} @var{command}. | |
39846 | ||
39847 | @item -directory=@var{directory} | |
39848 | @itemx -d @var{directory} | |
39849 | Add @var{directory} to the path to search for source files. | |
39850 | ||
39851 | @item -nh | |
39852 | Do not execute commands from @file{~/.gdbinit}. | |
39853 | ||
39854 | @item -nx | |
39855 | @itemx -n | |
39856 | Do not execute commands from any @file{.gdbinit} initialization files. | |
39857 | ||
39858 | @item -quiet | |
39859 | @itemx -q | |
39860 | ``Quiet''. Do not print the introductory and copyright messages. These | |
39861 | messages are also suppressed in batch mode. | |
39862 | ||
39863 | @item -batch | |
39864 | Run in batch mode. Exit with status @code{0} after processing all the command | |
39865 | files specified with @option{-x} (and @file{.gdbinit}, if not inhibited). | |
39866 | Exit with nonzero status if an error occurs in executing the @value{GDBN} | |
39867 | commands in the command files. | |
39868 | ||
39869 | Batch mode may be useful for running @value{GDBN} as a filter, for example to | |
39870 | download and run a program on another computer; in order to make this | |
39871 | more useful, the message | |
39872 | ||
39873 | @smallexample | |
39874 | Program exited normally. | |
39875 | @end smallexample | |
39876 | ||
39877 | @noindent | |
39878 | (which is ordinarily issued whenever a program running under @value{GDBN} control | |
39879 | terminates) is not issued when running in batch mode. | |
39880 | ||
39881 | @item -cd=@var{directory} | |
39882 | Run @value{GDBN} using @var{directory} as its working directory, | |
39883 | instead of the current directory. | |
39884 | ||
39885 | @item -fullname | |
39886 | @itemx -f | |
39887 | Emacs sets this option when it runs @value{GDBN} as a subprocess. It tells | |
39888 | @value{GDBN} to output the full file name and line number in a standard, | |
39889 | recognizable fashion each time a stack frame is displayed (which | |
39890 | includes each time the program stops). This recognizable format looks | |
39891 | like two @samp{\032} characters, followed by the file name, line number | |
39892 | and character position separated by colons, and a newline. The | |
39893 | Emacs-to-@value{GDBN} interface program uses the two @samp{\032} | |
39894 | characters as a signal to display the source code for the frame. | |
39895 | ||
39896 | @item -b @var{bps} | |
39897 | Set the line speed (baud rate or bits per second) of any serial | |
39898 | interface used by @value{GDBN} for remote debugging. | |
39899 | ||
39900 | @item -tty=@var{device} | |
39901 | Run using @var{device} for your program's standard input and output. | |
39902 | @end table | |
39903 | @c man end | |
39904 | ||
39905 | @c man begin SEEALSO gdb | |
39906 | @ifset man | |
39907 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
39908 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
39909 | documentation are properly installed at your site, the command | |
39910 | ||
39911 | @smallexample | |
39912 | info gdb | |
39913 | @end smallexample | |
39914 | ||
39915 | @noindent | |
39916 | should give you access to the complete manual. | |
39917 | ||
39918 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
39919 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
39920 | @end ifset | |
39921 | @c man end | |
39922 | ||
39923 | @node gdbserver man | |
39924 | @heading gdbserver man | |
39925 | ||
39926 | @c man title gdbserver Remote Server for the GNU Debugger | |
39927 | @format | |
39928 | @c man begin SYNOPSIS gdbserver | |
5b8b6385 | 39929 | gdbserver @var{comm} @var{prog} [@var{args}@dots{}] |
43662968 | 39930 | |
5b8b6385 JK |
39931 | gdbserver --attach @var{comm} @var{pid} |
39932 | ||
39933 | gdbserver --multi @var{comm} | |
43662968 JK |
39934 | @c man end |
39935 | @end format | |
39936 | ||
39937 | @c man begin DESCRIPTION gdbserver | |
39938 | @command{gdbserver} is a program that allows you to run @value{GDBN} on a different machine | |
39939 | than the one which is running the program being debugged. | |
39940 | ||
39941 | @ifclear man | |
39942 | @subheading Usage (server (target) side) | |
39943 | @end ifclear | |
39944 | @ifset man | |
39945 | Usage (server (target) side): | |
39946 | @end ifset | |
39947 | ||
39948 | First, you need to have a copy of the program you want to debug put onto | |
39949 | the target system. The program can be stripped to save space if needed, as | |
39950 | @command{gdbserver} doesn't care about symbols. All symbol handling is taken care of by | |
39951 | the @value{GDBN} running on the host system. | |
39952 | ||
39953 | To use the server, you log on to the target system, and run the @command{gdbserver} | |
39954 | program. You must tell it (a) how to communicate with @value{GDBN}, (b) the name of | |
39955 | your program, and (c) its arguments. The general syntax is: | |
39956 | ||
39957 | @smallexample | |
39958 | target> gdbserver @var{comm} @var{program} [@var{args} ...] | |
39959 | @end smallexample | |
39960 | ||
39961 | For example, using a serial port, you might say: | |
39962 | ||
39963 | @smallexample | |
39964 | @ifset man | |
39965 | @c @file would wrap it as F</dev/com1>. | |
39966 | target> gdbserver /dev/com1 emacs foo.txt | |
39967 | @end ifset | |
39968 | @ifclear man | |
39969 | target> gdbserver @file{/dev/com1} emacs foo.txt | |
39970 | @end ifclear | |
39971 | @end smallexample | |
39972 | ||
39973 | This tells @command{gdbserver} to debug emacs with an argument of foo.txt, and | |
39974 | to communicate with @value{GDBN} via @file{/dev/com1}. @command{gdbserver} now | |
39975 | waits patiently for the host @value{GDBN} to communicate with it. | |
39976 | ||
39977 | To use a TCP connection, you could say: | |
39978 | ||
39979 | @smallexample | |
39980 | target> gdbserver host:2345 emacs foo.txt | |
39981 | @end smallexample | |
39982 | ||
39983 | This says pretty much the same thing as the last example, except that we are | |
39984 | going to communicate with the @code{host} @value{GDBN} via TCP. The @code{host:2345} argument means | |
39985 | that we are expecting to see a TCP connection from @code{host} to local TCP port | |
39986 | 2345. (Currently, the @code{host} part is ignored.) You can choose any number you | |
39987 | want for the port number as long as it does not conflict with any existing TCP | |
39988 | ports on the target system. This same port number must be used in the host | |
39989 | @value{GDBN}s @code{target remote} command, which will be described shortly. Note that if | |
39990 | you chose a port number that conflicts with another service, @command{gdbserver} will | |
39991 | print an error message and exit. | |
39992 | ||
5b8b6385 | 39993 | @command{gdbserver} can also attach to running programs. |
43662968 JK |
39994 | This is accomplished via the @option{--attach} argument. The syntax is: |
39995 | ||
39996 | @smallexample | |
5b8b6385 | 39997 | target> gdbserver --attach @var{comm} @var{pid} |
43662968 JK |
39998 | @end smallexample |
39999 | ||
40000 | @var{pid} is the process ID of a currently running process. It isn't | |
40001 | necessary to point @command{gdbserver} at a binary for the running process. | |
40002 | ||
5b8b6385 JK |
40003 | To start @code{gdbserver} without supplying an initial command to run |
40004 | or process ID to attach, use the @option{--multi} command line option. | |
40005 | In such case you should connect using @kbd{target extended-remote} to start | |
40006 | the program you want to debug. | |
40007 | ||
40008 | @smallexample | |
40009 | target> gdbserver --multi @var{comm} | |
40010 | @end smallexample | |
40011 | ||
43662968 JK |
40012 | @ifclear man |
40013 | @subheading Usage (host side) | |
40014 | @end ifclear | |
40015 | @ifset man | |
40016 | Usage (host side): | |
40017 | @end ifset | |
40018 | ||
40019 | You need an unstripped copy of the target program on your host system, since | |
40020 | @value{GDBN} needs to examine it's symbol tables and such. Start up @value{GDBN} as you normally | |
40021 | would, with the target program as the first argument. (You may need to use the | |
40022 | @option{--baud} option if the serial line is running at anything except 9600 baud.) | |
40023 | That is @code{gdb TARGET-PROG}, or @code{gdb --baud BAUD TARGET-PROG}. After that, the only | |
5b8b6385 JK |
40024 | new command you need to know about is @code{target remote} |
40025 | (or @code{target extended-remote}). Its argument is either | |
43662968 JK |
40026 | a device name (usually a serial device, like @file{/dev/ttyb}), or a @code{HOST:PORT} |
40027 | descriptor. For example: | |
40028 | ||
40029 | @smallexample | |
40030 | @ifset man | |
40031 | @c @file would wrap it as F</dev/ttyb>. | |
40032 | (gdb) target remote /dev/ttyb | |
40033 | @end ifset | |
40034 | @ifclear man | |
40035 | (gdb) target remote @file{/dev/ttyb} | |
40036 | @end ifclear | |
40037 | @end smallexample | |
40038 | ||
40039 | @noindent | |
40040 | communicates with the server via serial line @file{/dev/ttyb}, and: | |
40041 | ||
40042 | @smallexample | |
40043 | (gdb) target remote the-target:2345 | |
40044 | @end smallexample | |
40045 | ||
40046 | @noindent | |
40047 | communicates via a TCP connection to port 2345 on host `the-target', where | |
40048 | you previously started up @command{gdbserver} with the same port number. Note that for | |
40049 | TCP connections, you must start up @command{gdbserver} prior to using the `target remote' | |
40050 | command, otherwise you may get an error that looks something like | |
40051 | `Connection refused'. | |
5b8b6385 JK |
40052 | |
40053 | @command{gdbserver} can also debug multiple inferiors at once, | |
40054 | described in | |
40055 | @ifset man | |
40056 | the @value{GDBN} manual in node @code{Inferiors and Programs} | |
40057 | -- shell command @code{info -f gdb -n 'Inferiors and Programs'}. | |
40058 | @end ifset | |
40059 | @ifclear man | |
40060 | @ref{Inferiors and Programs}. | |
40061 | @end ifclear | |
40062 | In such case use the @code{extended-remote} @value{GDBN} command variant: | |
40063 | ||
40064 | @smallexample | |
40065 | (gdb) target extended-remote the-target:2345 | |
40066 | @end smallexample | |
40067 | ||
40068 | The @command{gdbserver} option @option{--multi} may or may not be used in such | |
40069 | case. | |
43662968 JK |
40070 | @c man end |
40071 | ||
40072 | @c man begin OPTIONS gdbserver | |
5b8b6385 JK |
40073 | There are three different modes for invoking @command{gdbserver}: |
40074 | ||
40075 | @itemize @bullet | |
40076 | ||
40077 | @item | |
40078 | Debug a specific program specified by its program name: | |
40079 | ||
40080 | @smallexample | |
40081 | gdbserver @var{comm} @var{prog} [@var{args}@dots{}] | |
40082 | @end smallexample | |
40083 | ||
40084 | The @var{comm} parameter specifies how should the server communicate | |
40085 | with @value{GDBN}; it is either a device name (to use a serial line), | |
40086 | a TCP port number (@code{:1234}), or @code{-} or @code{stdio} to use | |
40087 | stdin/stdout of @code{gdbserver}. Specify the name of the program to | |
40088 | debug in @var{prog}. Any remaining arguments will be passed to the | |
40089 | program verbatim. When the program exits, @value{GDBN} will close the | |
40090 | connection, and @code{gdbserver} will exit. | |
40091 | ||
40092 | @item | |
40093 | Debug a specific program by specifying the process ID of a running | |
40094 | program: | |
40095 | ||
40096 | @smallexample | |
40097 | gdbserver --attach @var{comm} @var{pid} | |
40098 | @end smallexample | |
40099 | ||
40100 | The @var{comm} parameter is as described above. Supply the process ID | |
40101 | of a running program in @var{pid}; @value{GDBN} will do everything | |
40102 | else. Like with the previous mode, when the process @var{pid} exits, | |
40103 | @value{GDBN} will close the connection, and @code{gdbserver} will exit. | |
40104 | ||
40105 | @item | |
40106 | Multi-process mode -- debug more than one program/process: | |
40107 | ||
40108 | @smallexample | |
40109 | gdbserver --multi @var{comm} | |
40110 | @end smallexample | |
40111 | ||
40112 | In this mode, @value{GDBN} can instruct @command{gdbserver} which | |
40113 | command(s) to run. Unlike the other 2 modes, @value{GDBN} will not | |
40114 | close the connection when a process being debugged exits, so you can | |
40115 | debug several processes in the same session. | |
40116 | @end itemize | |
40117 | ||
40118 | In each of the modes you may specify these options: | |
40119 | ||
40120 | @table @env | |
40121 | ||
40122 | @item --help | |
40123 | List all options, with brief explanations. | |
40124 | ||
40125 | @item --version | |
40126 | This option causes @command{gdbserver} to print its version number and exit. | |
40127 | ||
40128 | @item --attach | |
40129 | @command{gdbserver} will attach to a running program. The syntax is: | |
40130 | ||
40131 | @smallexample | |
40132 | target> gdbserver --attach @var{comm} @var{pid} | |
40133 | @end smallexample | |
40134 | ||
40135 | @var{pid} is the process ID of a currently running process. It isn't | |
40136 | necessary to point @command{gdbserver} at a binary for the running process. | |
40137 | ||
40138 | @item --multi | |
40139 | To start @code{gdbserver} without supplying an initial command to run | |
40140 | or process ID to attach, use this command line option. | |
40141 | Then you can connect using @kbd{target extended-remote} and start | |
40142 | the program you want to debug. The syntax is: | |
40143 | ||
40144 | @smallexample | |
40145 | target> gdbserver --multi @var{comm} | |
40146 | @end smallexample | |
40147 | ||
40148 | @item --debug | |
40149 | Instruct @code{gdbserver} to display extra status information about the debugging | |
40150 | process. | |
40151 | This option is intended for @code{gdbserver} development and for bug reports to | |
40152 | the developers. | |
40153 | ||
40154 | @item --remote-debug | |
40155 | Instruct @code{gdbserver} to display remote protocol debug output. | |
40156 | This option is intended for @code{gdbserver} development and for bug reports to | |
40157 | the developers. | |
40158 | ||
87ce2a04 DE |
40159 | @item --debug-format=option1@r{[},option2,...@r{]} |
40160 | Instruct @code{gdbserver} to include extra information in each line | |
40161 | of debugging output. | |
40162 | @xref{Other Command-Line Arguments for gdbserver}. | |
40163 | ||
5b8b6385 JK |
40164 | @item --wrapper |
40165 | Specify a wrapper to launch programs | |
40166 | for debugging. The option should be followed by the name of the | |
40167 | wrapper, then any command-line arguments to pass to the wrapper, then | |
40168 | @kbd{--} indicating the end of the wrapper arguments. | |
40169 | ||
40170 | @item --once | |
40171 | By default, @command{gdbserver} keeps the listening TCP port open, so that | |
40172 | additional connections are possible. However, if you start @code{gdbserver} | |
40173 | with the @option{--once} option, it will stop listening for any further | |
40174 | connection attempts after connecting to the first @value{GDBN} session. | |
40175 | ||
40176 | @c --disable-packet is not documented for users. | |
40177 | ||
40178 | @c --disable-randomization and --no-disable-randomization are superseded by | |
40179 | @c QDisableRandomization. | |
40180 | ||
40181 | @end table | |
43662968 JK |
40182 | @c man end |
40183 | ||
40184 | @c man begin SEEALSO gdbserver | |
40185 | @ifset man | |
40186 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
40187 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
40188 | documentation are properly installed at your site, the command | |
40189 | ||
40190 | @smallexample | |
40191 | info gdb | |
40192 | @end smallexample | |
40193 | ||
40194 | should give you access to the complete manual. | |
40195 | ||
40196 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
40197 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
40198 | @end ifset | |
40199 | @c man end | |
40200 | ||
b292c783 JK |
40201 | @node gcore man |
40202 | @heading gcore | |
40203 | ||
40204 | @c man title gcore Generate a core file of a running program | |
40205 | ||
40206 | @format | |
40207 | @c man begin SYNOPSIS gcore | |
40208 | gcore [-o @var{filename}] @var{pid} | |
40209 | @c man end | |
40210 | @end format | |
40211 | ||
40212 | @c man begin DESCRIPTION gcore | |
40213 | Generate a core dump of a running program with process ID @var{pid}. | |
40214 | Produced file is equivalent to a kernel produced core file as if the process | |
40215 | crashed (and if @kbd{ulimit -c} were used to set up an appropriate core dump | |
40216 | limit). Unlike after a crash, after @command{gcore} the program remains | |
40217 | running without any change. | |
40218 | @c man end | |
40219 | ||
40220 | @c man begin OPTIONS gcore | |
40221 | @table @env | |
40222 | @item -o @var{filename} | |
40223 | The optional argument | |
40224 | @var{filename} specifies the file name where to put the core dump. | |
40225 | If not specified, the file name defaults to @file{core.@var{pid}}, | |
40226 | where @var{pid} is the running program process ID. | |
40227 | @end table | |
40228 | @c man end | |
40229 | ||
40230 | @c man begin SEEALSO gcore | |
40231 | @ifset man | |
40232 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
40233 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
40234 | documentation are properly installed at your site, the command | |
40235 | ||
40236 | @smallexample | |
40237 | info gdb | |
40238 | @end smallexample | |
40239 | ||
40240 | @noindent | |
40241 | should give you access to the complete manual. | |
40242 | ||
40243 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
40244 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
40245 | @end ifset | |
40246 | @c man end | |
40247 | ||
43662968 JK |
40248 | @node gdbinit man |
40249 | @heading gdbinit | |
40250 | ||
40251 | @c man title gdbinit GDB initialization scripts | |
40252 | ||
40253 | @format | |
40254 | @c man begin SYNOPSIS gdbinit | |
40255 | @ifset SYSTEM_GDBINIT | |
40256 | @value{SYSTEM_GDBINIT} | |
40257 | @end ifset | |
40258 | ||
40259 | ~/.gdbinit | |
40260 | ||
40261 | ./.gdbinit | |
40262 | @c man end | |
40263 | @end format | |
40264 | ||
40265 | @c man begin DESCRIPTION gdbinit | |
40266 | These files contain @value{GDBN} commands to automatically execute during | |
40267 | @value{GDBN} startup. The lines of contents are canned sequences of commands, | |
40268 | described in | |
40269 | @ifset man | |
40270 | the @value{GDBN} manual in node @code{Sequences} | |
40271 | -- shell command @code{info -f gdb -n Sequences}. | |
40272 | @end ifset | |
40273 | @ifclear man | |
40274 | @ref{Sequences}. | |
40275 | @end ifclear | |
40276 | ||
40277 | Please read more in | |
40278 | @ifset man | |
40279 | the @value{GDBN} manual in node @code{Startup} | |
40280 | -- shell command @code{info -f gdb -n Startup}. | |
40281 | @end ifset | |
40282 | @ifclear man | |
40283 | @ref{Startup}. | |
40284 | @end ifclear | |
40285 | ||
40286 | @table @env | |
40287 | @ifset SYSTEM_GDBINIT | |
40288 | @item @value{SYSTEM_GDBINIT} | |
40289 | @end ifset | |
40290 | @ifclear SYSTEM_GDBINIT | |
40291 | @item (not enabled with @code{--with-system-gdbinit} during compilation) | |
40292 | @end ifclear | |
40293 | System-wide initialization file. It is executed unless user specified | |
40294 | @value{GDBN} option @code{-nx} or @code{-n}. | |
40295 | See more in | |
40296 | @ifset man | |
40297 | the @value{GDBN} manual in node @code{System-wide configuration} | |
40298 | -- shell command @code{info -f gdb -n 'System-wide configuration'}. | |
40299 | @end ifset | |
40300 | @ifclear man | |
40301 | @ref{System-wide configuration}. | |
40302 | @end ifclear | |
40303 | ||
40304 | @item ~/.gdbinit | |
40305 | User initialization file. It is executed unless user specified | |
40306 | @value{GDBN} options @code{-nx}, @code{-n} or @code{-nh}. | |
40307 | ||
40308 | @item ./.gdbinit | |
40309 | Initialization file for current directory. It may need to be enabled with | |
40310 | @value{GDBN} security command @code{set auto-load local-gdbinit}. | |
40311 | See more in | |
40312 | @ifset man | |
40313 | the @value{GDBN} manual in node @code{Init File in the Current Directory} | |
40314 | -- shell command @code{info -f gdb -n 'Init File in the Current Directory'}. | |
40315 | @end ifset | |
40316 | @ifclear man | |
40317 | @ref{Init File in the Current Directory}. | |
40318 | @end ifclear | |
40319 | @end table | |
40320 | @c man end | |
40321 | ||
40322 | @c man begin SEEALSO gdbinit | |
40323 | @ifset man | |
40324 | gdb(1), @code{info -f gdb -n Startup} | |
40325 | ||
40326 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
40327 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
40328 | documentation are properly installed at your site, the command | |
40329 | ||
40330 | @smallexample | |
40331 | info gdb | |
40332 | @end smallexample | |
40333 | ||
40334 | should give you access to the complete manual. | |
40335 | ||
40336 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
40337 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
40338 | @end ifset | |
40339 | @c man end | |
40340 | ||
aab4e0ec | 40341 | @include gpl.texi |
eb12ee30 | 40342 | |
e4c0cfae SS |
40343 | @node GNU Free Documentation License |
40344 | @appendix GNU Free Documentation License | |
6826cf00 EZ |
40345 | @include fdl.texi |
40346 | ||
00595b5e EZ |
40347 | @node Concept Index |
40348 | @unnumbered Concept Index | |
c906108c SS |
40349 | |
40350 | @printindex cp | |
40351 | ||
00595b5e EZ |
40352 | @node Command and Variable Index |
40353 | @unnumbered Command, Variable, and Function Index | |
40354 | ||
40355 | @printindex fn | |
40356 | ||
c906108c | 40357 | @tex |
984359d2 | 40358 | % I think something like @@colophon should be in texinfo. In the |
c906108c SS |
40359 | % meantime: |
40360 | \long\def\colophon{\hbox to0pt{}\vfill | |
40361 | \centerline{The body of this manual is set in} | |
40362 | \centerline{\fontname\tenrm,} | |
40363 | \centerline{with headings in {\bf\fontname\tenbf}} | |
40364 | \centerline{and examples in {\tt\fontname\tentt}.} | |
40365 | \centerline{{\it\fontname\tenit\/},} | |
40366 | \centerline{{\bf\fontname\tenbf}, and} | |
40367 | \centerline{{\sl\fontname\tensl\/}} | |
40368 | \centerline{are used for emphasis.}\vfill} | |
40369 | \page\colophon | |
984359d2 | 40370 | % Blame: doc@@cygnus.com, 1991. |
c906108c SS |
40371 | @end tex |
40372 | ||
c906108c | 40373 | @bye |