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c906108c | 1 | \input texinfo @c -*-texinfo-*- |
b6ba6518 | 2 | @c Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, |
7d51c7de | 3 | @c 1999, 2000, 2001, 2002, 2003, 2004, 2005 |
c906108c SS |
4 | @c Free Software Foundation, Inc. |
5 | @c | |
5d161b24 | 6 | @c %**start of header |
c906108c SS |
7 | @c makeinfo ignores cmds prev to setfilename, so its arg cannot make use |
8 | @c of @set vars. However, you can override filename with makeinfo -o. | |
9 | @setfilename gdb.info | |
10 | @c | |
11 | @include gdb-cfg.texi | |
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 | |
23 | @syncodeindex ky cp | |
24 | ||
41afff9a | 25 | @c readline appendices use @vindex, @findex and @ftable, |
48e934c6 | 26 | @c annotate.texi and gdbmi use @findex. |
c906108c | 27 | @syncodeindex vr cp |
41afff9a | 28 | @syncodeindex fn cp |
c906108c SS |
29 | |
30 | @c !!set GDB manual's edition---not the same as GDB version! | |
9fe8321b | 31 | @c This is updated by GNU Press. |
e9c75b65 | 32 | @set EDITION Ninth |
c906108c | 33 | |
87885426 FN |
34 | @c !!set GDB edit command default editor |
35 | @set EDITOR /bin/ex | |
c906108c | 36 | |
6c0e9fb3 | 37 | @c THIS MANUAL REQUIRES TEXINFO 4.0 OR LATER. |
c906108c | 38 | |
c906108c | 39 | @c This is a dir.info fragment to support semi-automated addition of |
6d2ebf8b | 40 | @c manuals to an info tree. |
03727ca6 | 41 | @dircategory Software development |
96a2c332 | 42 | @direntry |
03727ca6 | 43 | * Gdb: (gdb). The GNU debugger. |
96a2c332 SS |
44 | @end direntry |
45 | ||
c906108c SS |
46 | @ifinfo |
47 | This file documents the @sc{gnu} debugger @value{GDBN}. | |
48 | ||
49 | ||
9fe8321b AC |
50 | This is the @value{EDITION} Edition, of @cite{Debugging with |
51 | @value{GDBN}: the @sc{gnu} Source-Level Debugger} for @value{GDBN} | |
52 | Version @value{GDBVN}. | |
c906108c | 53 | |
8a037dd7 | 54 | Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998,@* |
7d51c7de BR |
55 | 1999, 2000, 2001, 2002, 2003, 2004, 2005@* |
56 | Free Software Foundation, Inc. | |
c906108c | 57 | |
e9c75b65 EZ |
58 | Permission is granted to copy, distribute and/or modify this document |
59 | under the terms of the GNU Free Documentation License, Version 1.1 or | |
60 | any later version published by the Free Software Foundation; with the | |
959acfd1 EZ |
61 | Invariant Sections being ``Free Software'' and ``Free Software Needs |
62 | Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' | |
63 | and with the Back-Cover Texts as in (a) below. | |
c906108c | 64 | |
6826cf00 EZ |
65 | (a) The Free Software Foundation's Back-Cover Text is: ``You have |
66 | freedom to copy and modify this GNU Manual, like GNU software. Copies | |
67 | published by the Free Software Foundation raise funds for GNU | |
68 | development.'' | |
c906108c SS |
69 | @end ifinfo |
70 | ||
71 | @titlepage | |
72 | @title Debugging with @value{GDBN} | |
73 | @subtitle The @sc{gnu} Source-Level Debugger | |
c906108c | 74 | @sp 1 |
c906108c | 75 | @subtitle @value{EDITION} Edition, for @value{GDBN} version @value{GDBVN} |
9e9c5ae7 | 76 | @author Richard Stallman, Roland Pesch, Stan Shebs, et al. |
c906108c | 77 | @page |
c906108c SS |
78 | @tex |
79 | {\parskip=0pt | |
53a5351d | 80 | \hfill (Send bugs and comments on @value{GDBN} to bug-gdb\@gnu.org.)\par |
c906108c SS |
81 | \hfill {\it Debugging with @value{GDBN}}\par |
82 | \hfill \TeX{}info \texinfoversion\par | |
83 | } | |
84 | @end tex | |
53a5351d | 85 | |
c906108c | 86 | @vskip 0pt plus 1filll |
8a037dd7 | 87 | Copyright @copyright{} 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
7d51c7de BR |
88 | 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 |
89 | Free Software Foundation, Inc. | |
c906108c | 90 | @sp 2 |
c906108c SS |
91 | Published by the Free Software Foundation @* |
92 | 59 Temple Place - Suite 330, @* | |
93 | Boston, MA 02111-1307 USA @* | |
6d2ebf8b | 94 | ISBN 1-882114-77-9 @* |
e9c75b65 EZ |
95 | |
96 | Permission is granted to copy, distribute and/or modify this document | |
97 | under the terms of the GNU Free Documentation License, Version 1.1 or | |
98 | any later version published by the Free Software Foundation; with the | |
959acfd1 EZ |
99 | Invariant Sections being ``Free Software'' and ``Free Software Needs |
100 | Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' | |
101 | and with the Back-Cover Texts as in (a) below. | |
e9c75b65 | 102 | |
6826cf00 EZ |
103 | (a) The Free Software Foundation's Back-Cover Text is: ``You have |
104 | freedom to copy and modify this GNU Manual, like GNU software. Copies | |
105 | published by the Free Software Foundation raise funds for GNU | |
106 | development.'' | |
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 | ||
9fe8321b | 117 | This is the @value{EDITION} Edition, for @value{GDBN} Version |
c906108c SS |
118 | @value{GDBVN}. |
119 | ||
7d51c7de | 120 | Copyright (C) 1988-2005 Free Software Foundation, Inc. |
6d2ebf8b SS |
121 | |
122 | @menu | |
123 | * Summary:: Summary of @value{GDBN} | |
124 | * Sample Session:: A sample @value{GDBN} session | |
125 | ||
126 | * Invocation:: Getting in and out of @value{GDBN} | |
127 | * Commands:: @value{GDBN} commands | |
128 | * Running:: Running programs under @value{GDBN} | |
129 | * Stopping:: Stopping and continuing | |
130 | * Stack:: Examining the stack | |
131 | * Source:: Examining source files | |
132 | * Data:: Examining data | |
e2e0bcd1 | 133 | * Macros:: Preprocessor Macros |
b37052ae | 134 | * Tracepoints:: Debugging remote targets non-intrusively |
df0cd8c5 | 135 | * Overlays:: Debugging programs that use overlays |
6d2ebf8b SS |
136 | |
137 | * Languages:: Using @value{GDBN} with different languages | |
138 | ||
139 | * Symbols:: Examining the symbol table | |
140 | * Altering:: Altering execution | |
141 | * GDB Files:: @value{GDBN} files | |
142 | * Targets:: Specifying a debugging target | |
6b2f586d | 143 | * Remote Debugging:: Debugging remote programs |
6d2ebf8b SS |
144 | * Configurations:: Configuration-specific information |
145 | * Controlling GDB:: Controlling @value{GDBN} | |
146 | * Sequences:: Canned sequences of commands | |
c4555f82 | 147 | * TUI:: @value{GDBN} Text User Interface |
21c294e6 | 148 | * Interpreters:: Command Interpreters |
6d2ebf8b SS |
149 | * Emacs:: Using @value{GDBN} under @sc{gnu} Emacs |
150 | * Annotations:: @value{GDBN}'s annotation interface. | |
7162c0ca | 151 | * GDB/MI:: @value{GDBN}'s Machine Interface. |
6d2ebf8b SS |
152 | |
153 | * GDB Bugs:: Reporting bugs in @value{GDBN} | |
154 | * Formatting Documentation:: How to format and print @value{GDBN} documentation | |
155 | ||
156 | * Command Line Editing:: Command Line Editing | |
157 | * Using History Interactively:: Using History Interactively | |
158 | * Installing GDB:: Installing GDB | |
eb12ee30 | 159 | * Maintenance Commands:: Maintenance Commands |
e0ce93ac | 160 | * Remote Protocol:: GDB Remote Serial Protocol |
f418dd93 | 161 | * Agent Expressions:: The GDB Agent Expression Mechanism |
aab4e0ec AC |
162 | * Copying:: GNU General Public License says |
163 | how you can copy and share GDB | |
6826cf00 | 164 | * GNU Free Documentation License:: The license for this documentation |
6d2ebf8b SS |
165 | * Index:: Index |
166 | @end menu | |
167 | ||
6c0e9fb3 | 168 | @end ifnottex |
c906108c | 169 | |
449f3b6c | 170 | @contents |
449f3b6c | 171 | |
6d2ebf8b | 172 | @node Summary |
c906108c SS |
173 | @unnumbered Summary of @value{GDBN} |
174 | ||
175 | The purpose of a debugger such as @value{GDBN} is to allow you to see what is | |
176 | going on ``inside'' another program while it executes---or what another | |
177 | program was doing at the moment it crashed. | |
178 | ||
179 | @value{GDBN} can do four main kinds of things (plus other things in support of | |
180 | these) to help you catch bugs in the act: | |
181 | ||
182 | @itemize @bullet | |
183 | @item | |
184 | Start your program, specifying anything that might affect its behavior. | |
185 | ||
186 | @item | |
187 | Make your program stop on specified conditions. | |
188 | ||
189 | @item | |
190 | Examine what has happened, when your program has stopped. | |
191 | ||
192 | @item | |
193 | Change things in your program, so you can experiment with correcting the | |
194 | effects of one bug and go on to learn about another. | |
195 | @end itemize | |
196 | ||
49efadf5 | 197 | You can use @value{GDBN} to debug programs written in C and C@t{++}. |
9c16f35a | 198 | For more information, see @ref{Supported languages,,Supported languages}. |
c906108c SS |
199 | For more information, see @ref{C,,C and C++}. |
200 | ||
cce74817 | 201 | @cindex Modula-2 |
e632838e AC |
202 | Support for Modula-2 is partial. For information on Modula-2, see |
203 | @ref{Modula-2,,Modula-2}. | |
c906108c | 204 | |
cce74817 JM |
205 | @cindex Pascal |
206 | Debugging Pascal programs which use sets, subranges, file variables, or | |
207 | nested functions does not currently work. @value{GDBN} does not support | |
208 | entering expressions, printing values, or similar features using Pascal | |
209 | syntax. | |
c906108c | 210 | |
c906108c SS |
211 | @cindex Fortran |
212 | @value{GDBN} can be used to debug programs written in Fortran, although | |
53a5351d | 213 | it may be necessary to refer to some variables with a trailing |
cce74817 | 214 | underscore. |
c906108c | 215 | |
b37303ee AF |
216 | @value{GDBN} can be used to debug programs written in Objective-C, |
217 | using either the Apple/NeXT or the GNU Objective-C runtime. | |
218 | ||
c906108c SS |
219 | @menu |
220 | * Free Software:: Freely redistributable software | |
221 | * Contributors:: Contributors to GDB | |
222 | @end menu | |
223 | ||
6d2ebf8b | 224 | @node Free Software |
c906108c SS |
225 | @unnumberedsec Free software |
226 | ||
5d161b24 | 227 | @value{GDBN} is @dfn{free software}, protected by the @sc{gnu} |
c906108c SS |
228 | General Public License |
229 | (GPL). The GPL gives you the freedom to copy or adapt a licensed | |
230 | program---but every person getting a copy also gets with it the | |
231 | freedom to modify that copy (which means that they must get access to | |
232 | the source code), and the freedom to distribute further copies. | |
233 | Typical software companies use copyrights to limit your freedoms; the | |
234 | Free Software Foundation uses the GPL to preserve these freedoms. | |
235 | ||
236 | Fundamentally, the General Public License is a license which says that | |
237 | you have these freedoms and that you cannot take these freedoms away | |
238 | from anyone else. | |
239 | ||
2666264b | 240 | @unnumberedsec Free Software Needs Free Documentation |
959acfd1 EZ |
241 | |
242 | The biggest deficiency in the free software community today is not in | |
243 | the software---it is the lack of good free documentation that we can | |
244 | include with the free software. Many of our most important | |
245 | programs do not come with free reference manuals and free introductory | |
246 | texts. Documentation is an essential part of any software package; | |
247 | when an important free software package does not come with a free | |
248 | manual and a free tutorial, that is a major gap. We have many such | |
249 | gaps today. | |
250 | ||
251 | Consider Perl, for instance. The tutorial manuals that people | |
252 | normally use are non-free. How did this come about? Because the | |
253 | authors of those manuals published them with restrictive terms---no | |
254 | copying, no modification, source files not available---which exclude | |
255 | them from the free software world. | |
256 | ||
257 | That wasn't the first time this sort of thing happened, and it was far | |
258 | from the last. Many times we have heard a GNU user eagerly describe a | |
259 | manual that he is writing, his intended contribution to the community, | |
260 | only to learn that he had ruined everything by signing a publication | |
261 | contract to make it non-free. | |
262 | ||
263 | Free documentation, like free software, is a matter of freedom, not | |
264 | price. The problem with the non-free manual is not that publishers | |
265 | charge a price for printed copies---that in itself is fine. (The Free | |
266 | Software Foundation sells printed copies of manuals, too.) The | |
267 | problem is the restrictions on the use of the manual. Free manuals | |
268 | are available in source code form, and give you permission to copy and | |
269 | modify. Non-free manuals do not allow this. | |
270 | ||
271 | The criteria of freedom for a free manual are roughly the same as for | |
272 | free software. Redistribution (including the normal kinds of | |
273 | commercial redistribution) must be permitted, so that the manual can | |
274 | accompany every copy of the program, both on-line and on paper. | |
275 | ||
276 | Permission for modification of the technical content is crucial too. | |
277 | When people modify the software, adding or changing features, if they | |
278 | are conscientious they will change the manual too---so they can | |
279 | provide accurate and clear documentation for the modified program. A | |
280 | manual that leaves you no choice but to write a new manual to document | |
281 | a changed version of the program is not really available to our | |
282 | community. | |
283 | ||
284 | Some kinds of limits on the way modification is handled are | |
285 | acceptable. For example, requirements to preserve the original | |
286 | author's copyright notice, the distribution terms, or the list of | |
287 | authors, are ok. It is also no problem to require modified versions | |
288 | to include notice that they were modified. Even entire sections that | |
289 | may not be deleted or changed are acceptable, as long as they deal | |
290 | with nontechnical topics (like this one). These kinds of restrictions | |
291 | are acceptable because they don't obstruct the community's normal use | |
292 | of the manual. | |
293 | ||
294 | However, it must be possible to modify all the @emph{technical} | |
295 | content of the manual, and then distribute the result in all the usual | |
296 | media, through all the usual channels. Otherwise, the restrictions | |
297 | obstruct the use of the manual, it is not free, and we need another | |
298 | manual to replace it. | |
299 | ||
300 | Please spread the word about this issue. Our community continues to | |
301 | lose manuals to proprietary publishing. If we spread the word that | |
302 | free software needs free reference manuals and free tutorials, perhaps | |
303 | the next person who wants to contribute by writing documentation will | |
304 | realize, before it is too late, that only free manuals contribute to | |
305 | the free software community. | |
306 | ||
307 | If you are writing documentation, please insist on publishing it under | |
308 | the GNU Free Documentation License or another free documentation | |
309 | license. Remember that this decision requires your approval---you | |
310 | don't have to let the publisher decide. Some commercial publishers | |
311 | will use a free license if you insist, but they will not propose the | |
312 | option; it is up to you to raise the issue and say firmly that this is | |
313 | what you want. If the publisher you are dealing with refuses, please | |
314 | try other publishers. If you're not sure whether a proposed license | |
42584a72 | 315 | is free, write to @email{licensing@@gnu.org}. |
959acfd1 EZ |
316 | |
317 | You can encourage commercial publishers to sell more free, copylefted | |
318 | manuals and tutorials by buying them, and particularly by buying | |
319 | copies from the publishers that paid for their writing or for major | |
320 | improvements. Meanwhile, try to avoid buying non-free documentation | |
321 | at all. Check the distribution terms of a manual before you buy it, | |
322 | and insist that whoever seeks your business must respect your freedom. | |
72c9928d EZ |
323 | Check the history of the book, and try to reward the publishers that |
324 | have paid or pay the authors to work on it. | |
959acfd1 EZ |
325 | |
326 | The Free Software Foundation maintains a list of free documentation | |
327 | published by other publishers, at | |
328 | @url{http://www.fsf.org/doc/other-free-books.html}. | |
329 | ||
6d2ebf8b | 330 | @node Contributors |
96a2c332 SS |
331 | @unnumberedsec Contributors to @value{GDBN} |
332 | ||
333 | Richard Stallman was the original author of @value{GDBN}, and of many | |
334 | other @sc{gnu} programs. Many others have contributed to its | |
335 | development. This section attempts to credit major contributors. One | |
336 | of the virtues of free software is that everyone is free to contribute | |
337 | to it; with regret, we cannot actually acknowledge everyone here. The | |
338 | file @file{ChangeLog} in the @value{GDBN} distribution approximates a | |
c906108c SS |
339 | blow-by-blow account. |
340 | ||
341 | Changes much prior to version 2.0 are lost in the mists of time. | |
342 | ||
343 | @quotation | |
344 | @emph{Plea:} Additions to this section are particularly welcome. If you | |
345 | or your friends (or enemies, to be evenhanded) have been unfairly | |
346 | omitted from this list, we would like to add your names! | |
347 | @end quotation | |
348 | ||
349 | So that they may not regard their many labors as thankless, we | |
350 | particularly thank those who shepherded @value{GDBN} through major | |
351 | releases: | |
7ba3cf9c | 352 | Andrew Cagney (releases 6.3, 6.2, 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0); |
c906108c SS |
353 | Jim Blandy (release 4.18); |
354 | Jason Molenda (release 4.17); | |
355 | Stan Shebs (release 4.14); | |
356 | Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9); | |
357 | Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4); | |
358 | John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); | |
359 | Jim Kingdon (releases 3.5, 3.4, and 3.3); | |
360 | and Randy Smith (releases 3.2, 3.1, and 3.0). | |
361 | ||
362 | Richard Stallman, assisted at various times by Peter TerMaat, Chris | |
363 | Hanson, and Richard Mlynarik, handled releases through 2.8. | |
364 | ||
b37052ae EZ |
365 | Michael Tiemann is the author of most of the @sc{gnu} C@t{++} support |
366 | in @value{GDBN}, with significant additional contributions from Per | |
367 | Bothner and Daniel Berlin. James Clark wrote the @sc{gnu} C@t{++} | |
368 | demangler. Early work on C@t{++} was by Peter TerMaat (who also did | |
369 | much general update work leading to release 3.0). | |
c906108c | 370 | |
b37052ae | 371 | @value{GDBN} uses the BFD subroutine library to examine multiple |
c906108c SS |
372 | object-file formats; BFD was a joint project of David V. |
373 | Henkel-Wallace, Rich Pixley, Steve Chamberlain, and John Gilmore. | |
374 | ||
375 | David Johnson wrote the original COFF support; Pace Willison did | |
376 | the original support for encapsulated COFF. | |
377 | ||
0179ffac | 378 | Brent Benson of Harris Computer Systems contributed DWARF 2 support. |
c906108c SS |
379 | |
380 | Adam de Boor and Bradley Davis contributed the ISI Optimum V support. | |
381 | Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS | |
382 | support. | |
383 | Jean-Daniel Fekete contributed Sun 386i support. | |
384 | Chris Hanson improved the HP9000 support. | |
385 | Noboyuki Hikichi and Tomoyuki Hasei contributed Sony/News OS 3 support. | |
386 | David Johnson contributed Encore Umax support. | |
387 | Jyrki Kuoppala contributed Altos 3068 support. | |
388 | Jeff Law contributed HP PA and SOM support. | |
389 | Keith Packard contributed NS32K support. | |
390 | Doug Rabson contributed Acorn Risc Machine support. | |
391 | Bob Rusk contributed Harris Nighthawk CX-UX support. | |
392 | Chris Smith contributed Convex support (and Fortran debugging). | |
393 | Jonathan Stone contributed Pyramid support. | |
394 | Michael Tiemann contributed SPARC support. | |
395 | Tim Tucker contributed support for the Gould NP1 and Gould Powernode. | |
396 | Pace Willison contributed Intel 386 support. | |
397 | Jay Vosburgh contributed Symmetry support. | |
a37295f9 | 398 | Marko Mlinar contributed OpenRISC 1000 support. |
c906108c | 399 | |
1104b9e7 | 400 | Andreas Schwab contributed M68K @sc{gnu}/Linux support. |
c906108c SS |
401 | |
402 | Rich Schaefer and Peter Schauer helped with support of SunOS shared | |
403 | libraries. | |
404 | ||
405 | Jay Fenlason and Roland McGrath ensured that @value{GDBN} and GAS agree | |
406 | about several machine instruction sets. | |
407 | ||
408 | Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped develop | |
409 | remote debugging. Intel Corporation, Wind River Systems, AMD, and ARM | |
410 | contributed remote debugging modules for the i960, VxWorks, A29K UDI, | |
411 | and RDI targets, respectively. | |
412 | ||
413 | Brian Fox is the author of the readline libraries providing | |
414 | command-line editing and command history. | |
415 | ||
7a292a7a SS |
416 | Andrew Beers of SUNY Buffalo wrote the language-switching code, the |
417 | Modula-2 support, and contributed the Languages chapter of this manual. | |
c906108c | 418 | |
5d161b24 | 419 | Fred Fish wrote most of the support for Unix System Vr4. |
b37052ae | 420 | He also enhanced the command-completion support to cover C@t{++} overloaded |
c906108c | 421 | symbols. |
c906108c | 422 | |
f24c5e49 KI |
423 | Hitachi America (now Renesas America), Ltd. sponsored the support for |
424 | H8/300, H8/500, and Super-H processors. | |
c906108c SS |
425 | |
426 | NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx processors. | |
427 | ||
f24c5e49 KI |
428 | Mitsubishi (now Renesas) sponsored the support for D10V, D30V, and M32R/D |
429 | processors. | |
c906108c SS |
430 | |
431 | Toshiba sponsored the support for the TX39 Mips processor. | |
432 | ||
433 | Matsushita sponsored the support for the MN10200 and MN10300 processors. | |
434 | ||
96a2c332 | 435 | Fujitsu sponsored the support for SPARClite and FR30 processors. |
c906108c SS |
436 | |
437 | Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware | |
438 | watchpoints. | |
439 | ||
440 | Michael Snyder added support for tracepoints. | |
441 | ||
442 | Stu Grossman wrote gdbserver. | |
443 | ||
444 | Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made | |
96a2c332 | 445 | nearly innumerable bug fixes and cleanups throughout @value{GDBN}. |
c906108c SS |
446 | |
447 | The following people at the Hewlett-Packard Company contributed | |
448 | support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0 | |
b37052ae | 449 | (narrow mode), HP's implementation of kernel threads, HP's aC@t{++} |
d0d5df6f AC |
450 | compiler, and the Text User Interface (nee Terminal User Interface): |
451 | Ben Krepp, Richard Title, John Bishop, Susan Macchia, Kathy Mann, | |
452 | Satish Pai, India Paul, Steve Rehrauer, and Elena Zannoni. Kim Haase | |
453 | provided HP-specific information in this manual. | |
c906108c | 454 | |
b37052ae EZ |
455 | DJ Delorie ported @value{GDBN} to MS-DOS, for the DJGPP project. |
456 | Robert Hoehne made significant contributions to the DJGPP port. | |
457 | ||
96a2c332 SS |
458 | Cygnus Solutions has sponsored @value{GDBN} maintenance and much of its |
459 | development since 1991. Cygnus engineers who have worked on @value{GDBN} | |
2df3850c JM |
460 | fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin |
461 | Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim | |
462 | Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler, | |
463 | Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek | |
464 | Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In | |
465 | addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton, | |
466 | JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug | |
467 | Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff | |
468 | Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner, | |
469 | Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin | |
470 | Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela | |
471 | Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David | |
472 | Zuhn have made contributions both large and small. | |
c906108c | 473 | |
ffed4509 AC |
474 | Andrew Cagney, Fernando Nasser, and Elena Zannoni, while working for |
475 | Cygnus Solutions, implemented the original @sc{gdb/mi} interface. | |
476 | ||
e2e0bcd1 JB |
477 | Jim Blandy added support for preprocessor macros, while working for Red |
478 | Hat. | |
c906108c | 479 | |
a9967aef AC |
480 | Andrew Cagney designed @value{GDBN}'s architecture vector. Many |
481 | people including Andrew Cagney, Stephane Carrez, Randolph Chung, Nick | |
482 | Duffek, Richard Henderson, Mark Kettenis, Grace Sainsbury, Kei | |
483 | Sakamoto, Yoshinori Sato, Michael Snyder, Andreas Schwab, Jason | |
484 | Thorpe, Corinna Vinschen, Ulrich Weigand, and Elena Zannoni, helped | |
485 | with the migration of old architectures to this new framework. | |
486 | ||
6d2ebf8b | 487 | @node Sample Session |
c906108c SS |
488 | @chapter A Sample @value{GDBN} Session |
489 | ||
490 | You can use this manual at your leisure to read all about @value{GDBN}. | |
491 | However, a handful of commands are enough to get started using the | |
492 | debugger. This chapter illustrates those commands. | |
493 | ||
494 | @iftex | |
495 | In this sample session, we emphasize user input like this: @b{input}, | |
496 | to make it easier to pick out from the surrounding output. | |
497 | @end iftex | |
498 | ||
499 | @c FIXME: this example may not be appropriate for some configs, where | |
500 | @c FIXME...primary interest is in remote use. | |
501 | ||
502 | One of the preliminary versions of @sc{gnu} @code{m4} (a generic macro | |
503 | processor) exhibits the following bug: sometimes, when we change its | |
504 | quote strings from the default, the commands used to capture one macro | |
505 | definition within another stop working. In the following short @code{m4} | |
506 | session, we define a macro @code{foo} which expands to @code{0000}; we | |
507 | then use the @code{m4} built-in @code{defn} to define @code{bar} as the | |
508 | same thing. However, when we change the open quote string to | |
509 | @code{<QUOTE>} and the close quote string to @code{<UNQUOTE>}, the same | |
510 | procedure fails to define a new synonym @code{baz}: | |
511 | ||
512 | @smallexample | |
513 | $ @b{cd gnu/m4} | |
514 | $ @b{./m4} | |
515 | @b{define(foo,0000)} | |
516 | ||
517 | @b{foo} | |
518 | 0000 | |
519 | @b{define(bar,defn(`foo'))} | |
520 | ||
521 | @b{bar} | |
522 | 0000 | |
523 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
524 | ||
525 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
526 | @b{baz} | |
527 | @b{C-d} | |
528 | m4: End of input: 0: fatal error: EOF in string | |
529 | @end smallexample | |
530 | ||
531 | @noindent | |
532 | Let us use @value{GDBN} to try to see what is going on. | |
533 | ||
c906108c SS |
534 | @smallexample |
535 | $ @b{@value{GDBP} m4} | |
536 | @c FIXME: this falsifies the exact text played out, to permit smallbook | |
537 | @c FIXME... format to come out better. | |
538 | @value{GDBN} is free software and you are welcome to distribute copies | |
5d161b24 | 539 | of it under certain conditions; type "show copying" to see |
c906108c | 540 | the conditions. |
5d161b24 | 541 | There is absolutely no warranty for @value{GDBN}; type "show warranty" |
c906108c SS |
542 | for details. |
543 | ||
544 | @value{GDBN} @value{GDBVN}, Copyright 1999 Free Software Foundation, Inc... | |
545 | (@value{GDBP}) | |
546 | @end smallexample | |
c906108c SS |
547 | |
548 | @noindent | |
549 | @value{GDBN} reads only enough symbol data to know where to find the | |
550 | rest when needed; as a result, the first prompt comes up very quickly. | |
551 | We now tell @value{GDBN} to use a narrower display width than usual, so | |
552 | that examples fit in this manual. | |
553 | ||
554 | @smallexample | |
555 | (@value{GDBP}) @b{set width 70} | |
556 | @end smallexample | |
557 | ||
558 | @noindent | |
559 | We need to see how the @code{m4} built-in @code{changequote} works. | |
560 | Having looked at the source, we know the relevant subroutine is | |
561 | @code{m4_changequote}, so we set a breakpoint there with the @value{GDBN} | |
562 | @code{break} command. | |
563 | ||
564 | @smallexample | |
565 | (@value{GDBP}) @b{break m4_changequote} | |
566 | Breakpoint 1 at 0x62f4: file builtin.c, line 879. | |
567 | @end smallexample | |
568 | ||
569 | @noindent | |
570 | Using the @code{run} command, we start @code{m4} running under @value{GDBN} | |
571 | control; as long as control does not reach the @code{m4_changequote} | |
572 | subroutine, the program runs as usual: | |
573 | ||
574 | @smallexample | |
575 | (@value{GDBP}) @b{run} | |
576 | Starting program: /work/Editorial/gdb/gnu/m4/m4 | |
577 | @b{define(foo,0000)} | |
578 | ||
579 | @b{foo} | |
580 | 0000 | |
581 | @end smallexample | |
582 | ||
583 | @noindent | |
584 | To trigger the breakpoint, we call @code{changequote}. @value{GDBN} | |
585 | suspends execution of @code{m4}, displaying information about the | |
586 | context where it stops. | |
587 | ||
588 | @smallexample | |
589 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
590 | ||
5d161b24 | 591 | Breakpoint 1, m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
592 | at builtin.c:879 |
593 | 879 if (bad_argc(TOKEN_DATA_TEXT(argv[0]),argc,1,3)) | |
594 | @end smallexample | |
595 | ||
596 | @noindent | |
597 | Now we use the command @code{n} (@code{next}) to advance execution to | |
598 | the next line of the current function. | |
599 | ||
600 | @smallexample | |
601 | (@value{GDBP}) @b{n} | |
602 | 882 set_quotes((argc >= 2) ? TOKEN_DATA_TEXT(argv[1])\ | |
603 | : nil, | |
604 | @end smallexample | |
605 | ||
606 | @noindent | |
607 | @code{set_quotes} looks like a promising subroutine. We can go into it | |
608 | by using the command @code{s} (@code{step}) instead of @code{next}. | |
609 | @code{step} goes to the next line to be executed in @emph{any} | |
610 | subroutine, so it steps into @code{set_quotes}. | |
611 | ||
612 | @smallexample | |
613 | (@value{GDBP}) @b{s} | |
614 | set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
615 | at input.c:530 | |
616 | 530 if (lquote != def_lquote) | |
617 | @end smallexample | |
618 | ||
619 | @noindent | |
620 | The display that shows the subroutine where @code{m4} is now | |
621 | suspended (and its arguments) is called a stack frame display. It | |
622 | shows a summary of the stack. We can use the @code{backtrace} | |
623 | command (which can also be spelled @code{bt}), to see where we are | |
624 | in the stack as a whole: the @code{backtrace} command displays a | |
625 | stack frame for each active subroutine. | |
626 | ||
627 | @smallexample | |
628 | (@value{GDBP}) @b{bt} | |
629 | #0 set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
630 | at input.c:530 | |
5d161b24 | 631 | #1 0x6344 in m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
632 | at builtin.c:882 |
633 | #2 0x8174 in expand_macro (sym=0x33320) at macro.c:242 | |
634 | #3 0x7a88 in expand_token (obs=0x0, t=209696, td=0xf7fffa30) | |
635 | at macro.c:71 | |
636 | #4 0x79dc in expand_input () at macro.c:40 | |
637 | #5 0x2930 in main (argc=0, argv=0xf7fffb20) at m4.c:195 | |
638 | @end smallexample | |
639 | ||
640 | @noindent | |
641 | We step through a few more lines to see what happens. The first two | |
642 | times, we can use @samp{s}; the next two times we use @code{n} to avoid | |
643 | falling into the @code{xstrdup} subroutine. | |
644 | ||
645 | @smallexample | |
646 | (@value{GDBP}) @b{s} | |
647 | 0x3b5c 532 if (rquote != def_rquote) | |
648 | (@value{GDBP}) @b{s} | |
649 | 0x3b80 535 lquote = (lq == nil || *lq == '\0') ? \ | |
650 | def_lquote : xstrdup(lq); | |
651 | (@value{GDBP}) @b{n} | |
652 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
653 | : xstrdup(rq); | |
654 | (@value{GDBP}) @b{n} | |
655 | 538 len_lquote = strlen(rquote); | |
656 | @end smallexample | |
657 | ||
658 | @noindent | |
659 | The last line displayed looks a little odd; we can examine the variables | |
660 | @code{lquote} and @code{rquote} to see if they are in fact the new left | |
661 | and right quotes we specified. We use the command @code{p} | |
662 | (@code{print}) to see their values. | |
663 | ||
664 | @smallexample | |
665 | (@value{GDBP}) @b{p lquote} | |
666 | $1 = 0x35d40 "<QUOTE>" | |
667 | (@value{GDBP}) @b{p rquote} | |
668 | $2 = 0x35d50 "<UNQUOTE>" | |
669 | @end smallexample | |
670 | ||
671 | @noindent | |
672 | @code{lquote} and @code{rquote} are indeed the new left and right quotes. | |
673 | To look at some context, we can display ten lines of source | |
674 | surrounding the current line with the @code{l} (@code{list}) command. | |
675 | ||
676 | @smallexample | |
677 | (@value{GDBP}) @b{l} | |
678 | 533 xfree(rquote); | |
679 | 534 | |
680 | 535 lquote = (lq == nil || *lq == '\0') ? def_lquote\ | |
681 | : xstrdup (lq); | |
682 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
683 | : xstrdup (rq); | |
684 | 537 | |
685 | 538 len_lquote = strlen(rquote); | |
686 | 539 len_rquote = strlen(lquote); | |
687 | 540 @} | |
688 | 541 | |
689 | 542 void | |
690 | @end smallexample | |
691 | ||
692 | @noindent | |
693 | Let us step past the two lines that set @code{len_lquote} and | |
694 | @code{len_rquote}, and then examine the values of those variables. | |
695 | ||
696 | @smallexample | |
697 | (@value{GDBP}) @b{n} | |
698 | 539 len_rquote = strlen(lquote); | |
699 | (@value{GDBP}) @b{n} | |
700 | 540 @} | |
701 | (@value{GDBP}) @b{p len_lquote} | |
702 | $3 = 9 | |
703 | (@value{GDBP}) @b{p len_rquote} | |
704 | $4 = 7 | |
705 | @end smallexample | |
706 | ||
707 | @noindent | |
708 | That certainly looks wrong, assuming @code{len_lquote} and | |
709 | @code{len_rquote} are meant to be the lengths of @code{lquote} and | |
710 | @code{rquote} respectively. We can set them to better values using | |
711 | the @code{p} command, since it can print the value of | |
712 | any expression---and that expression can include subroutine calls and | |
713 | assignments. | |
714 | ||
715 | @smallexample | |
716 | (@value{GDBP}) @b{p len_lquote=strlen(lquote)} | |
717 | $5 = 7 | |
718 | (@value{GDBP}) @b{p len_rquote=strlen(rquote)} | |
719 | $6 = 9 | |
720 | @end smallexample | |
721 | ||
722 | @noindent | |
723 | Is that enough to fix the problem of using the new quotes with the | |
724 | @code{m4} built-in @code{defn}? We can allow @code{m4} to continue | |
725 | executing with the @code{c} (@code{continue}) command, and then try the | |
726 | example that caused trouble initially: | |
727 | ||
728 | @smallexample | |
729 | (@value{GDBP}) @b{c} | |
730 | Continuing. | |
731 | ||
732 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
733 | ||
734 | baz | |
735 | 0000 | |
736 | @end smallexample | |
737 | ||
738 | @noindent | |
739 | Success! The new quotes now work just as well as the default ones. The | |
740 | problem seems to have been just the two typos defining the wrong | |
741 | lengths. We allow @code{m4} exit by giving it an EOF as input: | |
742 | ||
743 | @smallexample | |
744 | @b{C-d} | |
745 | Program exited normally. | |
746 | @end smallexample | |
747 | ||
748 | @noindent | |
749 | The message @samp{Program exited normally.} is from @value{GDBN}; it | |
750 | indicates @code{m4} has finished executing. We can end our @value{GDBN} | |
751 | session with the @value{GDBN} @code{quit} command. | |
752 | ||
753 | @smallexample | |
754 | (@value{GDBP}) @b{quit} | |
755 | @end smallexample | |
c906108c | 756 | |
6d2ebf8b | 757 | @node Invocation |
c906108c SS |
758 | @chapter Getting In and Out of @value{GDBN} |
759 | ||
760 | This chapter discusses how to start @value{GDBN}, and how to get out of it. | |
5d161b24 | 761 | The essentials are: |
c906108c | 762 | @itemize @bullet |
5d161b24 | 763 | @item |
53a5351d | 764 | type @samp{@value{GDBP}} to start @value{GDBN}. |
5d161b24 | 765 | @item |
c906108c SS |
766 | type @kbd{quit} or @kbd{C-d} to exit. |
767 | @end itemize | |
768 | ||
769 | @menu | |
770 | * Invoking GDB:: How to start @value{GDBN} | |
771 | * Quitting GDB:: How to quit @value{GDBN} | |
772 | * Shell Commands:: How to use shell commands inside @value{GDBN} | |
0fac0b41 | 773 | * Logging output:: How to log @value{GDBN}'s output to a file |
c906108c SS |
774 | @end menu |
775 | ||
6d2ebf8b | 776 | @node Invoking GDB |
c906108c SS |
777 | @section Invoking @value{GDBN} |
778 | ||
c906108c SS |
779 | Invoke @value{GDBN} by running the program @code{@value{GDBP}}. Once started, |
780 | @value{GDBN} reads commands from the terminal until you tell it to exit. | |
781 | ||
782 | You can also run @code{@value{GDBP}} with a variety of arguments and options, | |
783 | to specify more of your debugging environment at the outset. | |
784 | ||
c906108c SS |
785 | The command-line options described here are designed |
786 | to cover a variety of situations; in some environments, some of these | |
5d161b24 | 787 | options may effectively be unavailable. |
c906108c SS |
788 | |
789 | The most usual way to start @value{GDBN} is with one argument, | |
790 | specifying an executable program: | |
791 | ||
474c8240 | 792 | @smallexample |
c906108c | 793 | @value{GDBP} @var{program} |
474c8240 | 794 | @end smallexample |
c906108c | 795 | |
c906108c SS |
796 | @noindent |
797 | You can also start with both an executable program and a core file | |
798 | specified: | |
799 | ||
474c8240 | 800 | @smallexample |
c906108c | 801 | @value{GDBP} @var{program} @var{core} |
474c8240 | 802 | @end smallexample |
c906108c SS |
803 | |
804 | You can, instead, specify a process ID as a second argument, if you want | |
805 | to debug a running process: | |
806 | ||
474c8240 | 807 | @smallexample |
c906108c | 808 | @value{GDBP} @var{program} 1234 |
474c8240 | 809 | @end smallexample |
c906108c SS |
810 | |
811 | @noindent | |
812 | would attach @value{GDBN} to process @code{1234} (unless you also have a file | |
813 | named @file{1234}; @value{GDBN} does check for a core file first). | |
814 | ||
c906108c | 815 | Taking advantage of the second command-line argument requires a fairly |
2df3850c JM |
816 | complete operating system; when you use @value{GDBN} as a remote |
817 | debugger attached to a bare board, there may not be any notion of | |
818 | ``process'', and there is often no way to get a core dump. @value{GDBN} | |
819 | will warn you if it is unable to attach or to read core dumps. | |
c906108c | 820 | |
aa26fa3a TT |
821 | You can optionally have @code{@value{GDBP}} pass any arguments after the |
822 | executable file to the inferior using @code{--args}. This option stops | |
823 | option processing. | |
474c8240 | 824 | @smallexample |
aa26fa3a | 825 | gdb --args gcc -O2 -c foo.c |
474c8240 | 826 | @end smallexample |
aa26fa3a TT |
827 | This will cause @code{@value{GDBP}} to debug @code{gcc}, and to set |
828 | @code{gcc}'s command-line arguments (@pxref{Arguments}) to @samp{-O2 -c foo.c}. | |
829 | ||
96a2c332 | 830 | You can run @code{@value{GDBP}} without printing the front material, which describes |
c906108c SS |
831 | @value{GDBN}'s non-warranty, by specifying @code{-silent}: |
832 | ||
833 | @smallexample | |
834 | @value{GDBP} -silent | |
835 | @end smallexample | |
836 | ||
837 | @noindent | |
838 | You can further control how @value{GDBN} starts up by using command-line | |
839 | options. @value{GDBN} itself can remind you of the options available. | |
840 | ||
841 | @noindent | |
842 | Type | |
843 | ||
474c8240 | 844 | @smallexample |
c906108c | 845 | @value{GDBP} -help |
474c8240 | 846 | @end smallexample |
c906108c SS |
847 | |
848 | @noindent | |
849 | to display all available options and briefly describe their use | |
850 | (@samp{@value{GDBP} -h} is a shorter equivalent). | |
851 | ||
852 | All options and command line arguments you give are processed | |
853 | in sequential order. The order makes a difference when the | |
854 | @samp{-x} option is used. | |
855 | ||
856 | ||
857 | @menu | |
c906108c SS |
858 | * File Options:: Choosing files |
859 | * Mode Options:: Choosing modes | |
6fc08d32 | 860 | * Startup:: What @value{GDBN} does during startup |
c906108c SS |
861 | @end menu |
862 | ||
6d2ebf8b | 863 | @node File Options |
c906108c SS |
864 | @subsection Choosing files |
865 | ||
2df3850c | 866 | When @value{GDBN} starts, it reads any arguments other than options as |
c906108c SS |
867 | specifying an executable file and core file (or process ID). This is |
868 | the same as if the arguments were specified by the @samp{-se} and | |
19837790 MS |
869 | @samp{-c} (or @samp{-p} options respectively. (@value{GDBN} reads the |
870 | first argument that does not have an associated option flag as | |
871 | equivalent to the @samp{-se} option followed by that argument; and the | |
872 | second argument that does not have an associated option flag, if any, as | |
873 | equivalent to the @samp{-c}/@samp{-p} option followed by that argument.) | |
874 | If the second argument begins with a decimal digit, @value{GDBN} will | |
875 | first attempt to attach to it as a process, and if that fails, attempt | |
876 | to open it as a corefile. If you have a corefile whose name begins with | |
b383017d | 877 | a digit, you can prevent @value{GDBN} from treating it as a pid by |
79f12247 | 878 | prefixing it with @file{./}, eg. @file{./12345}. |
7a292a7a SS |
879 | |
880 | If @value{GDBN} has not been configured to included core file support, | |
881 | such as for most embedded targets, then it will complain about a second | |
882 | argument and ignore it. | |
c906108c SS |
883 | |
884 | Many options have both long and short forms; both are shown in the | |
885 | following list. @value{GDBN} also recognizes the long forms if you truncate | |
886 | them, so long as enough of the option is present to be unambiguous. | |
887 | (If you prefer, you can flag option arguments with @samp{--} rather | |
888 | than @samp{-}, though we illustrate the more usual convention.) | |
889 | ||
d700128c EZ |
890 | @c NOTE: the @cindex entries here use double dashes ON PURPOSE. This |
891 | @c way, both those who look for -foo and --foo in the index, will find | |
892 | @c it. | |
893 | ||
c906108c SS |
894 | @table @code |
895 | @item -symbols @var{file} | |
896 | @itemx -s @var{file} | |
d700128c EZ |
897 | @cindex @code{--symbols} |
898 | @cindex @code{-s} | |
c906108c SS |
899 | Read symbol table from file @var{file}. |
900 | ||
901 | @item -exec @var{file} | |
902 | @itemx -e @var{file} | |
d700128c EZ |
903 | @cindex @code{--exec} |
904 | @cindex @code{-e} | |
7a292a7a SS |
905 | Use file @var{file} as the executable file to execute when appropriate, |
906 | and for examining pure data in conjunction with a core dump. | |
c906108c SS |
907 | |
908 | @item -se @var{file} | |
d700128c | 909 | @cindex @code{--se} |
c906108c SS |
910 | Read symbol table from file @var{file} and use it as the executable |
911 | file. | |
912 | ||
c906108c SS |
913 | @item -core @var{file} |
914 | @itemx -c @var{file} | |
d700128c EZ |
915 | @cindex @code{--core} |
916 | @cindex @code{-c} | |
b383017d | 917 | Use file @var{file} as a core dump to examine. |
c906108c SS |
918 | |
919 | @item -c @var{number} | |
19837790 MS |
920 | @item -pid @var{number} |
921 | @itemx -p @var{number} | |
922 | @cindex @code{--pid} | |
923 | @cindex @code{-p} | |
924 | Connect to process ID @var{number}, as with the @code{attach} command. | |
925 | If there is no such process, @value{GDBN} will attempt to open a core | |
926 | file named @var{number}. | |
c906108c SS |
927 | |
928 | @item -command @var{file} | |
929 | @itemx -x @var{file} | |
d700128c EZ |
930 | @cindex @code{--command} |
931 | @cindex @code{-x} | |
c906108c SS |
932 | Execute @value{GDBN} commands from file @var{file}. @xref{Command |
933 | Files,, Command files}. | |
934 | ||
8a5a3c82 AS |
935 | @item -eval-command @var{command} |
936 | @itemx -ex @var{command} | |
937 | @cindex @code{--eval-command} | |
938 | @cindex @code{-ex} | |
939 | Execute a single @value{GDBN} command. | |
940 | ||
941 | This option may be used multiple times to call multiple commands. It may | |
942 | also be interleaved with @samp{-command} as required. | |
943 | ||
944 | @smallexample | |
945 | @value{GDBP} -ex 'target sim' -ex 'load' \ | |
946 | -x setbreakpoints -ex 'run' a.out | |
947 | @end smallexample | |
948 | ||
c906108c SS |
949 | @item -directory @var{directory} |
950 | @itemx -d @var{directory} | |
d700128c EZ |
951 | @cindex @code{--directory} |
952 | @cindex @code{-d} | |
c906108c SS |
953 | Add @var{directory} to the path to search for source files. |
954 | ||
c906108c SS |
955 | @item -r |
956 | @itemx -readnow | |
d700128c EZ |
957 | @cindex @code{--readnow} |
958 | @cindex @code{-r} | |
c906108c SS |
959 | Read each symbol file's entire symbol table immediately, rather than |
960 | the default, which is to read it incrementally as it is needed. | |
961 | This makes startup slower, but makes future operations faster. | |
53a5351d | 962 | |
c906108c SS |
963 | @end table |
964 | ||
6d2ebf8b | 965 | @node Mode Options |
c906108c SS |
966 | @subsection Choosing modes |
967 | ||
968 | You can run @value{GDBN} in various alternative modes---for example, in | |
969 | batch mode or quiet mode. | |
970 | ||
971 | @table @code | |
972 | @item -nx | |
973 | @itemx -n | |
d700128c EZ |
974 | @cindex @code{--nx} |
975 | @cindex @code{-n} | |
96565e91 | 976 | Do not execute commands found in any initialization files. Normally, |
2df3850c JM |
977 | @value{GDBN} executes the commands in these files after all the command |
978 | options and arguments have been processed. @xref{Command Files,,Command | |
979 | files}. | |
c906108c SS |
980 | |
981 | @item -quiet | |
d700128c | 982 | @itemx -silent |
c906108c | 983 | @itemx -q |
d700128c EZ |
984 | @cindex @code{--quiet} |
985 | @cindex @code{--silent} | |
986 | @cindex @code{-q} | |
c906108c SS |
987 | ``Quiet''. Do not print the introductory and copyright messages. These |
988 | messages are also suppressed in batch mode. | |
989 | ||
990 | @item -batch | |
d700128c | 991 | @cindex @code{--batch} |
c906108c SS |
992 | Run in batch mode. Exit with status @code{0} after processing all the |
993 | command files specified with @samp{-x} (and all commands from | |
994 | initialization files, if not inhibited with @samp{-n}). Exit with | |
995 | nonzero status if an error occurs in executing the @value{GDBN} commands | |
996 | in the command files. | |
997 | ||
2df3850c JM |
998 | Batch mode may be useful for running @value{GDBN} as a filter, for |
999 | example to download and run a program on another computer; in order to | |
1000 | make this more useful, the message | |
c906108c | 1001 | |
474c8240 | 1002 | @smallexample |
c906108c | 1003 | Program exited normally. |
474c8240 | 1004 | @end smallexample |
c906108c SS |
1005 | |
1006 | @noindent | |
2df3850c JM |
1007 | (which is ordinarily issued whenever a program running under |
1008 | @value{GDBN} control terminates) is not issued when running in batch | |
1009 | mode. | |
1010 | ||
1a088d06 AS |
1011 | @item -batch-silent |
1012 | @cindex @code{--batch-silent} | |
1013 | Run in batch mode exactly like @samp{-batch}, but totally silently. All | |
1014 | @value{GDBN} output to @code{stdout} is prevented (@code{stderr} is | |
1015 | unaffected). This is much quieter than @samp{-silent} and would be useless | |
1016 | for an interactive session. | |
1017 | ||
1018 | This is particularly useful when using targets that give @samp{Loading section} | |
1019 | messages, for example. | |
1020 | ||
1021 | Note that targets that give their output via @value{GDBN}, as opposed to | |
1022 | writing directly to @code{stdout}, will also be made silent. | |
1023 | ||
4b0ad762 AS |
1024 | @item -return-child-result |
1025 | @cindex @code{--return-child-result} | |
1026 | The return code from @value{GDBN} will be the return code from the child | |
1027 | process (the process being debugged), with the following exceptions: | |
1028 | ||
1029 | @itemize @bullet | |
1030 | @item | |
1031 | @value{GDBN} exits abnormally. E.g., due to an incorrect argument or an | |
1032 | internal error. In this case the exit code is the same as it would have been | |
1033 | without @samp{-return-child-result}. | |
1034 | @item | |
1035 | The user quits with an explicit value. E.g., @samp{quit 1}. | |
1036 | @item | |
1037 | The child process never runs, or is not allowed to terminate, in which case | |
1038 | the exit code will be -1. | |
1039 | @end itemize | |
1040 | ||
1041 | This option is useful in conjunction with @samp{-batch} or @samp{-batch-silent}, | |
1042 | when @value{GDBN} is being used as a remote program loader or simulator | |
1043 | interface. | |
1044 | ||
2df3850c JM |
1045 | @item -nowindows |
1046 | @itemx -nw | |
d700128c EZ |
1047 | @cindex @code{--nowindows} |
1048 | @cindex @code{-nw} | |
2df3850c | 1049 | ``No windows''. If @value{GDBN} comes with a graphical user interface |
96a2c332 | 1050 | (GUI) built in, then this option tells @value{GDBN} to only use the command-line |
2df3850c JM |
1051 | interface. If no GUI is available, this option has no effect. |
1052 | ||
1053 | @item -windows | |
1054 | @itemx -w | |
d700128c EZ |
1055 | @cindex @code{--windows} |
1056 | @cindex @code{-w} | |
2df3850c JM |
1057 | If @value{GDBN} includes a GUI, then this option requires it to be |
1058 | used if possible. | |
c906108c SS |
1059 | |
1060 | @item -cd @var{directory} | |
d700128c | 1061 | @cindex @code{--cd} |
c906108c SS |
1062 | Run @value{GDBN} using @var{directory} as its working directory, |
1063 | instead of the current directory. | |
1064 | ||
c906108c SS |
1065 | @item -fullname |
1066 | @itemx -f | |
d700128c EZ |
1067 | @cindex @code{--fullname} |
1068 | @cindex @code{-f} | |
7a292a7a SS |
1069 | @sc{gnu} Emacs sets this option when it runs @value{GDBN} as a |
1070 | subprocess. It tells @value{GDBN} to output the full file name and line | |
1071 | number in a standard, recognizable fashion each time a stack frame is | |
1072 | displayed (which includes each time your program stops). This | |
1073 | recognizable format looks like two @samp{\032} characters, followed by | |
1074 | the file name, line number and character position separated by colons, | |
1075 | and a newline. The Emacs-to-@value{GDBN} interface program uses the two | |
1076 | @samp{\032} characters as a signal to display the source code for the | |
1077 | frame. | |
c906108c | 1078 | |
d700128c EZ |
1079 | @item -epoch |
1080 | @cindex @code{--epoch} | |
1081 | The Epoch Emacs-@value{GDBN} interface sets this option when it runs | |
1082 | @value{GDBN} as a subprocess. It tells @value{GDBN} to modify its print | |
1083 | routines so as to allow Epoch to display values of expressions in a | |
1084 | separate window. | |
1085 | ||
1086 | @item -annotate @var{level} | |
1087 | @cindex @code{--annotate} | |
1088 | This option sets the @dfn{annotation level} inside @value{GDBN}. Its | |
1089 | effect is identical to using @samp{set annotate @var{level}} | |
086432e2 AC |
1090 | (@pxref{Annotations}). The annotation @var{level} controls how much |
1091 | information @value{GDBN} prints together with its prompt, values of | |
1092 | expressions, source lines, and other types of output. Level 0 is the | |
1093 | normal, level 1 is for use when @value{GDBN} is run as a subprocess of | |
1094 | @sc{gnu} Emacs, level 3 is the maximum annotation suitable for programs | |
1095 | that control @value{GDBN}, and level 2 has been deprecated. | |
1096 | ||
265eeb58 | 1097 | The annotation mechanism has largely been superseded by @sc{gdb/mi} |
086432e2 | 1098 | (@pxref{GDB/MI}). |
d700128c | 1099 | |
aa26fa3a TT |
1100 | @item --args |
1101 | @cindex @code{--args} | |
1102 | Change interpretation of command line so that arguments following the | |
1103 | executable file are passed as command line arguments to the inferior. | |
1104 | This option stops option processing. | |
1105 | ||
2df3850c JM |
1106 | @item -baud @var{bps} |
1107 | @itemx -b @var{bps} | |
d700128c EZ |
1108 | @cindex @code{--baud} |
1109 | @cindex @code{-b} | |
c906108c SS |
1110 | Set the line speed (baud rate or bits per second) of any serial |
1111 | interface used by @value{GDBN} for remote debugging. | |
c906108c | 1112 | |
f47b1503 AS |
1113 | @item -l @var{timeout} |
1114 | @cindex @code{-l} | |
1115 | Set the timeout (in seconds) of any communication used by @value{GDBN} | |
1116 | for remote debugging. | |
1117 | ||
c906108c | 1118 | @item -tty @var{device} |
d700128c EZ |
1119 | @itemx -t @var{device} |
1120 | @cindex @code{--tty} | |
1121 | @cindex @code{-t} | |
c906108c SS |
1122 | Run using @var{device} for your program's standard input and output. |
1123 | @c FIXME: kingdon thinks there is more to -tty. Investigate. | |
c906108c | 1124 | |
53a5351d | 1125 | @c resolve the situation of these eventually |
c4555f82 SC |
1126 | @item -tui |
1127 | @cindex @code{--tui} | |
d0d5df6f AC |
1128 | Activate the @dfn{Text User Interface} when starting. The Text User |
1129 | Interface manages several text windows on the terminal, showing | |
1130 | source, assembly, registers and @value{GDBN} command outputs | |
1131 | (@pxref{TUI, ,@value{GDBN} Text User Interface}). Alternatively, the | |
1132 | Text User Interface can be enabled by invoking the program | |
1133 | @samp{gdbtui}. Do not use this option if you run @value{GDBN} from | |
1134 | Emacs (@pxref{Emacs, ,Using @value{GDBN} under @sc{gnu} Emacs}). | |
53a5351d JM |
1135 | |
1136 | @c @item -xdb | |
d700128c | 1137 | @c @cindex @code{--xdb} |
53a5351d JM |
1138 | @c Run in XDB compatibility mode, allowing the use of certain XDB commands. |
1139 | @c For information, see the file @file{xdb_trans.html}, which is usually | |
1140 | @c installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX | |
1141 | @c systems. | |
1142 | ||
d700128c EZ |
1143 | @item -interpreter @var{interp} |
1144 | @cindex @code{--interpreter} | |
1145 | Use the interpreter @var{interp} for interface with the controlling | |
1146 | program or device. This option is meant to be set by programs which | |
94bbb2c0 | 1147 | communicate with @value{GDBN} using it as a back end. |
21c294e6 | 1148 | @xref{Interpreters, , Command Interpreters}. |
94bbb2c0 | 1149 | |
da0f9dcd | 1150 | @samp{--interpreter=mi} (or @samp{--interpreter=mi2}) causes |
2fcf52f0 | 1151 | @value{GDBN} to use the @dfn{@sc{gdb/mi} interface} (@pxref{GDB/MI, , |
6b5e8c01 | 1152 | The @sc{gdb/mi} Interface}) included since @value{GDBN} version 6.0. The |
6c74ac8b AC |
1153 | previous @sc{gdb/mi} interface, included in @value{GDBN} version 5.3 and |
1154 | selected with @samp{--interpreter=mi1}, is deprecated. Earlier | |
1155 | @sc{gdb/mi} interfaces are no longer supported. | |
d700128c EZ |
1156 | |
1157 | @item -write | |
1158 | @cindex @code{--write} | |
1159 | Open the executable and core files for both reading and writing. This | |
1160 | is equivalent to the @samp{set write on} command inside @value{GDBN} | |
1161 | (@pxref{Patching}). | |
1162 | ||
1163 | @item -statistics | |
1164 | @cindex @code{--statistics} | |
1165 | This option causes @value{GDBN} to print statistics about time and | |
1166 | memory usage after it completes each command and returns to the prompt. | |
1167 | ||
1168 | @item -version | |
1169 | @cindex @code{--version} | |
1170 | This option causes @value{GDBN} to print its version number and | |
1171 | no-warranty blurb, and exit. | |
1172 | ||
c906108c SS |
1173 | @end table |
1174 | ||
6fc08d32 EZ |
1175 | @node Startup |
1176 | @subsection What @value{GDBN} does during startup | |
1177 | @cindex @value{GDBN} startup | |
1178 | ||
1179 | Here's the description of what @value{GDBN} does during session startup: | |
1180 | ||
1181 | @enumerate | |
1182 | @item | |
1183 | Sets up the command interpreter as specified by the command line | |
1184 | (@pxref{Mode Options, interpreter}). | |
1185 | ||
1186 | @item | |
1187 | @cindex init file | |
1188 | Reads the @dfn{init file} (if any) in your home directory@footnote{On | |
1189 | DOS/Windows systems, the home directory is the one pointed to by the | |
1190 | @code{HOME} environment variable.} and executes all the commands in | |
1191 | that file. | |
1192 | ||
1193 | @item | |
1194 | Processes command line options and operands. | |
1195 | ||
1196 | @item | |
1197 | Reads and executes the commands from init file (if any) in the current | |
119b882a EZ |
1198 | working directory. This is only done if the current directory is |
1199 | different from your home directory. Thus, you can have more than one | |
1200 | init file, one generic in your home directory, and another, specific | |
1201 | to the program you are debugging, in the directory where you invoke | |
6fc08d32 EZ |
1202 | @value{GDBN}. |
1203 | ||
1204 | @item | |
1205 | Reads command files specified by the @samp{-x} option. @xref{Command | |
1206 | Files}, for more details about @value{GDBN} command files. | |
1207 | ||
1208 | @item | |
1209 | Reads the command history recorded in the @dfn{history file}. | |
d620b259 | 1210 | @xref{Command History}, for more details about the command history and the |
6fc08d32 EZ |
1211 | files where @value{GDBN} records it. |
1212 | @end enumerate | |
1213 | ||
1214 | Init files use the same syntax as @dfn{command files} (@pxref{Command | |
1215 | Files}) and are processed by @value{GDBN} in the same way. The init | |
1216 | file in your home directory can set options (such as @samp{set | |
1217 | complaints}) that affect subsequent processing of command line options | |
1218 | and operands. Init files are not executed if you use the @samp{-nx} | |
1219 | option (@pxref{Mode Options, ,Choosing modes}). | |
1220 | ||
1221 | @cindex init file name | |
1222 | @cindex @file{.gdbinit} | |
119b882a | 1223 | The @value{GDBN} init files are normally called @file{.gdbinit}. |
6fc08d32 EZ |
1224 | On some configurations of @value{GDBN}, the init file is known by a |
1225 | different name (these are typically environments where a specialized | |
1226 | form of @value{GDBN} may need to coexist with other forms, hence a | |
1227 | different name for the specialized version's init file). These are the | |
1228 | environments with special init file names: | |
1229 | ||
6fc08d32 | 1230 | @itemize @bullet |
119b882a EZ |
1231 | @cindex @file{gdb.ini} |
1232 | @item | |
1233 | The DJGPP port of @value{GDBN} uses the name @file{gdb.ini}, due to | |
1234 | the limitations of file names imposed by DOS filesystems. The Windows | |
1235 | ports of @value{GDBN} use the standard name, but if they find a | |
1236 | @file{gdb.ini} file, they warn you about that and suggest to rename | |
1237 | the file to the standard name. | |
1238 | ||
1239 | @cindex @file{.vxgdbinit} | |
6fc08d32 EZ |
1240 | @item |
1241 | VxWorks (Wind River Systems real-time OS): @file{.vxgdbinit} | |
1242 | ||
1243 | @cindex @file{.os68gdbinit} | |
1244 | @item | |
1245 | OS68K (Enea Data Systems real-time OS): @file{.os68gdbinit} | |
1246 | ||
1247 | @cindex @file{.esgdbinit} | |
1248 | @item | |
1249 | ES-1800 (Ericsson Telecom AB M68000 emulator): @file{.esgdbinit} | |
1250 | ||
1251 | @item | |
1252 | CISCO 68k: @file{.cisco-gdbinit} | |
1253 | @end itemize | |
1254 | ||
1255 | ||
6d2ebf8b | 1256 | @node Quitting GDB |
c906108c SS |
1257 | @section Quitting @value{GDBN} |
1258 | @cindex exiting @value{GDBN} | |
1259 | @cindex leaving @value{GDBN} | |
1260 | ||
1261 | @table @code | |
1262 | @kindex quit @r{[}@var{expression}@r{]} | |
41afff9a | 1263 | @kindex q @r{(@code{quit})} |
96a2c332 SS |
1264 | @item quit @r{[}@var{expression}@r{]} |
1265 | @itemx q | |
1266 | To exit @value{GDBN}, use the @code{quit} command (abbreviated | |
1267 | @code{q}), or type an end-of-file character (usually @kbd{C-d}). If you | |
1268 | do not supply @var{expression}, @value{GDBN} will terminate normally; | |
1269 | otherwise it will terminate using the result of @var{expression} as the | |
1270 | error code. | |
c906108c SS |
1271 | @end table |
1272 | ||
1273 | @cindex interrupt | |
1274 | An interrupt (often @kbd{C-c}) does not exit from @value{GDBN}, but rather | |
1275 | terminates the action of any @value{GDBN} command that is in progress and | |
1276 | returns to @value{GDBN} command level. It is safe to type the interrupt | |
1277 | character at any time because @value{GDBN} does not allow it to take effect | |
1278 | until a time when it is safe. | |
1279 | ||
c906108c SS |
1280 | If you have been using @value{GDBN} to control an attached process or |
1281 | device, you can release it with the @code{detach} command | |
1282 | (@pxref{Attach, ,Debugging an already-running process}). | |
c906108c | 1283 | |
6d2ebf8b | 1284 | @node Shell Commands |
c906108c SS |
1285 | @section Shell commands |
1286 | ||
1287 | If you need to execute occasional shell commands during your | |
1288 | debugging session, there is no need to leave or suspend @value{GDBN}; you can | |
1289 | just use the @code{shell} command. | |
1290 | ||
1291 | @table @code | |
1292 | @kindex shell | |
1293 | @cindex shell escape | |
1294 | @item shell @var{command string} | |
1295 | Invoke a standard shell to execute @var{command string}. | |
c906108c | 1296 | If it exists, the environment variable @code{SHELL} determines which |
d4f3574e SS |
1297 | shell to run. Otherwise @value{GDBN} uses the default shell |
1298 | (@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.). | |
c906108c SS |
1299 | @end table |
1300 | ||
1301 | The utility @code{make} is often needed in development environments. | |
1302 | You do not have to use the @code{shell} command for this purpose in | |
1303 | @value{GDBN}: | |
1304 | ||
1305 | @table @code | |
1306 | @kindex make | |
1307 | @cindex calling make | |
1308 | @item make @var{make-args} | |
1309 | Execute the @code{make} program with the specified | |
1310 | arguments. This is equivalent to @samp{shell make @var{make-args}}. | |
1311 | @end table | |
1312 | ||
0fac0b41 DJ |
1313 | @node Logging output |
1314 | @section Logging output | |
1315 | @cindex logging @value{GDBN} output | |
9c16f35a | 1316 | @cindex save @value{GDBN} output to a file |
0fac0b41 DJ |
1317 | |
1318 | You may want to save the output of @value{GDBN} commands to a file. | |
1319 | There are several commands to control @value{GDBN}'s logging. | |
1320 | ||
1321 | @table @code | |
1322 | @kindex set logging | |
1323 | @item set logging on | |
1324 | Enable logging. | |
1325 | @item set logging off | |
1326 | Disable logging. | |
9c16f35a | 1327 | @cindex logging file name |
0fac0b41 DJ |
1328 | @item set logging file @var{file} |
1329 | Change the name of the current logfile. The default logfile is @file{gdb.txt}. | |
1330 | @item set logging overwrite [on|off] | |
1331 | By default, @value{GDBN} will append to the logfile. Set @code{overwrite} if | |
1332 | you want @code{set logging on} to overwrite the logfile instead. | |
1333 | @item set logging redirect [on|off] | |
1334 | By default, @value{GDBN} output will go to both the terminal and the logfile. | |
1335 | Set @code{redirect} if you want output to go only to the log file. | |
1336 | @kindex show logging | |
1337 | @item show logging | |
1338 | Show the current values of the logging settings. | |
1339 | @end table | |
1340 | ||
6d2ebf8b | 1341 | @node Commands |
c906108c SS |
1342 | @chapter @value{GDBN} Commands |
1343 | ||
1344 | You can abbreviate a @value{GDBN} command to the first few letters of the command | |
1345 | name, if that abbreviation is unambiguous; and you can repeat certain | |
1346 | @value{GDBN} commands by typing just @key{RET}. You can also use the @key{TAB} | |
1347 | key to get @value{GDBN} to fill out the rest of a word in a command (or to | |
1348 | show you the alternatives available, if there is more than one possibility). | |
1349 | ||
1350 | @menu | |
1351 | * Command Syntax:: How to give commands to @value{GDBN} | |
1352 | * Completion:: Command completion | |
1353 | * Help:: How to ask @value{GDBN} for help | |
1354 | @end menu | |
1355 | ||
6d2ebf8b | 1356 | @node Command Syntax |
c906108c SS |
1357 | @section Command syntax |
1358 | ||
1359 | A @value{GDBN} command is a single line of input. There is no limit on | |
1360 | how long it can be. It starts with a command name, which is followed by | |
1361 | arguments whose meaning depends on the command name. For example, the | |
1362 | command @code{step} accepts an argument which is the number of times to | |
1363 | step, as in @samp{step 5}. You can also use the @code{step} command | |
96a2c332 | 1364 | with no arguments. Some commands do not allow any arguments. |
c906108c SS |
1365 | |
1366 | @cindex abbreviation | |
1367 | @value{GDBN} command names may always be truncated if that abbreviation is | |
1368 | unambiguous. Other possible command abbreviations are listed in the | |
1369 | documentation for individual commands. In some cases, even ambiguous | |
1370 | abbreviations are allowed; for example, @code{s} is specially defined as | |
1371 | equivalent to @code{step} even though there are other commands whose | |
1372 | names start with @code{s}. You can test abbreviations by using them as | |
1373 | arguments to the @code{help} command. | |
1374 | ||
1375 | @cindex repeating commands | |
41afff9a | 1376 | @kindex RET @r{(repeat last command)} |
c906108c | 1377 | A blank line as input to @value{GDBN} (typing just @key{RET}) means to |
96a2c332 | 1378 | repeat the previous command. Certain commands (for example, @code{run}) |
c906108c SS |
1379 | will not repeat this way; these are commands whose unintentional |
1380 | repetition might cause trouble and which you are unlikely to want to | |
c45da7e6 EZ |
1381 | repeat. User-defined commands can disable this feature; see |
1382 | @ref{Define, dont-repeat}. | |
c906108c SS |
1383 | |
1384 | The @code{list} and @code{x} commands, when you repeat them with | |
1385 | @key{RET}, construct new arguments rather than repeating | |
1386 | exactly as typed. This permits easy scanning of source or memory. | |
1387 | ||
1388 | @value{GDBN} can also use @key{RET} in another way: to partition lengthy | |
1389 | output, in a way similar to the common utility @code{more} | |
1390 | (@pxref{Screen Size,,Screen size}). Since it is easy to press one | |
1391 | @key{RET} too many in this situation, @value{GDBN} disables command | |
1392 | repetition after any command that generates this sort of display. | |
1393 | ||
41afff9a | 1394 | @kindex # @r{(a comment)} |
c906108c SS |
1395 | @cindex comment |
1396 | Any text from a @kbd{#} to the end of the line is a comment; it does | |
1397 | nothing. This is useful mainly in command files (@pxref{Command | |
1398 | Files,,Command files}). | |
1399 | ||
88118b3a TT |
1400 | @cindex repeating command sequences |
1401 | @kindex C-o @r{(operate-and-get-next)} | |
1402 | The @kbd{C-o} binding is useful for repeating a complex sequence of | |
1403 | commands. This command accepts the current line, like @kbd{RET}, and | |
1404 | then fetches the next line relative to the current line from the history | |
1405 | for editing. | |
1406 | ||
6d2ebf8b | 1407 | @node Completion |
c906108c SS |
1408 | @section Command completion |
1409 | ||
1410 | @cindex completion | |
1411 | @cindex word completion | |
1412 | @value{GDBN} can fill in the rest of a word in a command for you, if there is | |
1413 | only one possibility; it can also show you what the valid possibilities | |
1414 | are for the next word in a command, at any time. This works for @value{GDBN} | |
1415 | commands, @value{GDBN} subcommands, and the names of symbols in your program. | |
1416 | ||
1417 | Press the @key{TAB} key whenever you want @value{GDBN} to fill out the rest | |
1418 | of a word. If there is only one possibility, @value{GDBN} fills in the | |
1419 | word, and waits for you to finish the command (or press @key{RET} to | |
1420 | enter it). For example, if you type | |
1421 | ||
1422 | @c FIXME "@key" does not distinguish its argument sufficiently to permit | |
1423 | @c complete accuracy in these examples; space introduced for clarity. | |
1424 | @c If texinfo enhancements make it unnecessary, it would be nice to | |
1425 | @c replace " @key" by "@key" in the following... | |
474c8240 | 1426 | @smallexample |
c906108c | 1427 | (@value{GDBP}) info bre @key{TAB} |
474c8240 | 1428 | @end smallexample |
c906108c SS |
1429 | |
1430 | @noindent | |
1431 | @value{GDBN} fills in the rest of the word @samp{breakpoints}, since that is | |
1432 | the only @code{info} subcommand beginning with @samp{bre}: | |
1433 | ||
474c8240 | 1434 | @smallexample |
c906108c | 1435 | (@value{GDBP}) info breakpoints |
474c8240 | 1436 | @end smallexample |
c906108c SS |
1437 | |
1438 | @noindent | |
1439 | You can either press @key{RET} at this point, to run the @code{info | |
1440 | breakpoints} command, or backspace and enter something else, if | |
1441 | @samp{breakpoints} does not look like the command you expected. (If you | |
1442 | were sure you wanted @code{info breakpoints} in the first place, you | |
1443 | might as well just type @key{RET} immediately after @samp{info bre}, | |
1444 | to exploit command abbreviations rather than command completion). | |
1445 | ||
1446 | If there is more than one possibility for the next word when you press | |
1447 | @key{TAB}, @value{GDBN} sounds a bell. You can either supply more | |
1448 | characters and try again, or just press @key{TAB} a second time; | |
1449 | @value{GDBN} displays all the possible completions for that word. For | |
1450 | example, you might want to set a breakpoint on a subroutine whose name | |
1451 | begins with @samp{make_}, but when you type @kbd{b make_@key{TAB}} @value{GDBN} | |
1452 | just sounds the bell. Typing @key{TAB} again displays all the | |
1453 | function names in your program that begin with those characters, for | |
1454 | example: | |
1455 | ||
474c8240 | 1456 | @smallexample |
c906108c SS |
1457 | (@value{GDBP}) b make_ @key{TAB} |
1458 | @exdent @value{GDBN} sounds bell; press @key{TAB} again, to see: | |
5d161b24 DB |
1459 | make_a_section_from_file make_environ |
1460 | make_abs_section make_function_type | |
1461 | make_blockvector make_pointer_type | |
1462 | make_cleanup make_reference_type | |
c906108c SS |
1463 | make_command make_symbol_completion_list |
1464 | (@value{GDBP}) b make_ | |
474c8240 | 1465 | @end smallexample |
c906108c SS |
1466 | |
1467 | @noindent | |
1468 | After displaying the available possibilities, @value{GDBN} copies your | |
1469 | partial input (@samp{b make_} in the example) so you can finish the | |
1470 | command. | |
1471 | ||
1472 | If you just want to see the list of alternatives in the first place, you | |
b37052ae | 1473 | can press @kbd{M-?} rather than pressing @key{TAB} twice. @kbd{M-?} |
7a292a7a | 1474 | means @kbd{@key{META} ?}. You can type this either by holding down a |
c906108c | 1475 | key designated as the @key{META} shift on your keyboard (if there is |
7a292a7a | 1476 | one) while typing @kbd{?}, or as @key{ESC} followed by @kbd{?}. |
c906108c SS |
1477 | |
1478 | @cindex quotes in commands | |
1479 | @cindex completion of quoted strings | |
1480 | Sometimes the string you need, while logically a ``word'', may contain | |
7a292a7a SS |
1481 | parentheses or other characters that @value{GDBN} normally excludes from |
1482 | its notion of a word. To permit word completion to work in this | |
1483 | situation, you may enclose words in @code{'} (single quote marks) in | |
1484 | @value{GDBN} commands. | |
c906108c | 1485 | |
c906108c | 1486 | The most likely situation where you might need this is in typing the |
b37052ae EZ |
1487 | name of a C@t{++} function. This is because C@t{++} allows function |
1488 | overloading (multiple definitions of the same function, distinguished | |
1489 | by argument type). For example, when you want to set a breakpoint you | |
1490 | may need to distinguish whether you mean the version of @code{name} | |
1491 | that takes an @code{int} parameter, @code{name(int)}, or the version | |
1492 | that takes a @code{float} parameter, @code{name(float)}. To use the | |
1493 | word-completion facilities in this situation, type a single quote | |
1494 | @code{'} at the beginning of the function name. This alerts | |
1495 | @value{GDBN} that it may need to consider more information than usual | |
1496 | when you press @key{TAB} or @kbd{M-?} to request word completion: | |
c906108c | 1497 | |
474c8240 | 1498 | @smallexample |
96a2c332 | 1499 | (@value{GDBP}) b 'bubble( @kbd{M-?} |
c906108c SS |
1500 | bubble(double,double) bubble(int,int) |
1501 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1502 | @end smallexample |
c906108c SS |
1503 | |
1504 | In some cases, @value{GDBN} can tell that completing a name requires using | |
1505 | quotes. When this happens, @value{GDBN} inserts the quote for you (while | |
1506 | completing as much as it can) if you do not type the quote in the first | |
1507 | place: | |
1508 | ||
474c8240 | 1509 | @smallexample |
c906108c SS |
1510 | (@value{GDBP}) b bub @key{TAB} |
1511 | @exdent @value{GDBN} alters your input line to the following, and rings a bell: | |
1512 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1513 | @end smallexample |
c906108c SS |
1514 | |
1515 | @noindent | |
1516 | In general, @value{GDBN} can tell that a quote is needed (and inserts it) if | |
1517 | you have not yet started typing the argument list when you ask for | |
1518 | completion on an overloaded symbol. | |
1519 | ||
d4f3574e | 1520 | For more information about overloaded functions, see @ref{C plus plus |
b37052ae | 1521 | expressions, ,C@t{++} expressions}. You can use the command @code{set |
c906108c | 1522 | overload-resolution off} to disable overload resolution; |
b37052ae | 1523 | see @ref{Debugging C plus plus, ,@value{GDBN} features for C@t{++}}. |
c906108c SS |
1524 | |
1525 | ||
6d2ebf8b | 1526 | @node Help |
c906108c SS |
1527 | @section Getting help |
1528 | @cindex online documentation | |
1529 | @kindex help | |
1530 | ||
5d161b24 | 1531 | You can always ask @value{GDBN} itself for information on its commands, |
c906108c SS |
1532 | using the command @code{help}. |
1533 | ||
1534 | @table @code | |
41afff9a | 1535 | @kindex h @r{(@code{help})} |
c906108c SS |
1536 | @item help |
1537 | @itemx h | |
1538 | You can use @code{help} (abbreviated @code{h}) with no arguments to | |
1539 | display a short list of named classes of commands: | |
1540 | ||
1541 | @smallexample | |
1542 | (@value{GDBP}) help | |
1543 | List of classes of commands: | |
1544 | ||
2df3850c | 1545 | aliases -- Aliases of other commands |
c906108c | 1546 | breakpoints -- Making program stop at certain points |
2df3850c | 1547 | data -- Examining data |
c906108c | 1548 | files -- Specifying and examining files |
2df3850c JM |
1549 | internals -- Maintenance commands |
1550 | obscure -- Obscure features | |
1551 | running -- Running the program | |
1552 | stack -- Examining the stack | |
c906108c SS |
1553 | status -- Status inquiries |
1554 | support -- Support facilities | |
96a2c332 SS |
1555 | tracepoints -- Tracing of program execution without@* |
1556 | stopping the program | |
c906108c | 1557 | user-defined -- User-defined commands |
c906108c | 1558 | |
5d161b24 | 1559 | Type "help" followed by a class name for a list of |
c906108c | 1560 | commands in that class. |
5d161b24 | 1561 | Type "help" followed by command name for full |
c906108c SS |
1562 | documentation. |
1563 | Command name abbreviations are allowed if unambiguous. | |
1564 | (@value{GDBP}) | |
1565 | @end smallexample | |
96a2c332 | 1566 | @c the above line break eliminates huge line overfull... |
c906108c SS |
1567 | |
1568 | @item help @var{class} | |
1569 | Using one of the general help classes as an argument, you can get a | |
1570 | list of the individual commands in that class. For example, here is the | |
1571 | help display for the class @code{status}: | |
1572 | ||
1573 | @smallexample | |
1574 | (@value{GDBP}) help status | |
1575 | Status inquiries. | |
1576 | ||
1577 | List of commands: | |
1578 | ||
1579 | @c Line break in "show" line falsifies real output, but needed | |
1580 | @c to fit in smallbook page size. | |
2df3850c JM |
1581 | info -- Generic command for showing things |
1582 | about the program being debugged | |
1583 | show -- Generic command for showing things | |
1584 | about the debugger | |
c906108c | 1585 | |
5d161b24 | 1586 | Type "help" followed by command name for full |
c906108c SS |
1587 | documentation. |
1588 | Command name abbreviations are allowed if unambiguous. | |
1589 | (@value{GDBP}) | |
1590 | @end smallexample | |
1591 | ||
1592 | @item help @var{command} | |
1593 | With a command name as @code{help} argument, @value{GDBN} displays a | |
1594 | short paragraph on how to use that command. | |
1595 | ||
6837a0a2 DB |
1596 | @kindex apropos |
1597 | @item apropos @var{args} | |
09d4efe1 | 1598 | The @code{apropos} command searches through all of the @value{GDBN} |
6837a0a2 DB |
1599 | commands, and their documentation, for the regular expression specified in |
1600 | @var{args}. It prints out all matches found. For example: | |
1601 | ||
1602 | @smallexample | |
1603 | apropos reload | |
1604 | @end smallexample | |
1605 | ||
b37052ae EZ |
1606 | @noindent |
1607 | results in: | |
6837a0a2 DB |
1608 | |
1609 | @smallexample | |
6d2ebf8b SS |
1610 | @c @group |
1611 | set symbol-reloading -- Set dynamic symbol table reloading | |
1612 | multiple times in one run | |
1613 | show symbol-reloading -- Show dynamic symbol table reloading | |
1614 | multiple times in one run | |
1615 | @c @end group | |
6837a0a2 DB |
1616 | @end smallexample |
1617 | ||
c906108c SS |
1618 | @kindex complete |
1619 | @item complete @var{args} | |
1620 | The @code{complete @var{args}} command lists all the possible completions | |
1621 | for the beginning of a command. Use @var{args} to specify the beginning of the | |
1622 | command you want completed. For example: | |
1623 | ||
1624 | @smallexample | |
1625 | complete i | |
1626 | @end smallexample | |
1627 | ||
1628 | @noindent results in: | |
1629 | ||
1630 | @smallexample | |
1631 | @group | |
2df3850c JM |
1632 | if |
1633 | ignore | |
c906108c SS |
1634 | info |
1635 | inspect | |
c906108c SS |
1636 | @end group |
1637 | @end smallexample | |
1638 | ||
1639 | @noindent This is intended for use by @sc{gnu} Emacs. | |
1640 | @end table | |
1641 | ||
1642 | In addition to @code{help}, you can use the @value{GDBN} commands @code{info} | |
1643 | and @code{show} to inquire about the state of your program, or the state | |
1644 | of @value{GDBN} itself. Each command supports many topics of inquiry; this | |
1645 | manual introduces each of them in the appropriate context. The listings | |
1646 | under @code{info} and under @code{show} in the Index point to | |
1647 | all the sub-commands. @xref{Index}. | |
1648 | ||
1649 | @c @group | |
1650 | @table @code | |
1651 | @kindex info | |
41afff9a | 1652 | @kindex i @r{(@code{info})} |
c906108c SS |
1653 | @item info |
1654 | This command (abbreviated @code{i}) is for describing the state of your | |
1655 | program. For example, you can list the arguments given to your program | |
1656 | with @code{info args}, list the registers currently in use with @code{info | |
1657 | registers}, or list the breakpoints you have set with @code{info breakpoints}. | |
1658 | You can get a complete list of the @code{info} sub-commands with | |
1659 | @w{@code{help info}}. | |
1660 | ||
1661 | @kindex set | |
1662 | @item set | |
5d161b24 | 1663 | You can assign the result of an expression to an environment variable with |
c906108c SS |
1664 | @code{set}. For example, you can set the @value{GDBN} prompt to a $-sign with |
1665 | @code{set prompt $}. | |
1666 | ||
1667 | @kindex show | |
1668 | @item show | |
5d161b24 | 1669 | In contrast to @code{info}, @code{show} is for describing the state of |
c906108c SS |
1670 | @value{GDBN} itself. |
1671 | You can change most of the things you can @code{show}, by using the | |
1672 | related command @code{set}; for example, you can control what number | |
1673 | system is used for displays with @code{set radix}, or simply inquire | |
1674 | which is currently in use with @code{show radix}. | |
1675 | ||
1676 | @kindex info set | |
1677 | To display all the settable parameters and their current | |
1678 | values, you can use @code{show} with no arguments; you may also use | |
1679 | @code{info set}. Both commands produce the same display. | |
1680 | @c FIXME: "info set" violates the rule that "info" is for state of | |
1681 | @c FIXME...program. Ck w/ GNU: "info set" to be called something else, | |
1682 | @c FIXME...or change desc of rule---eg "state of prog and debugging session"? | |
1683 | @end table | |
1684 | @c @end group | |
1685 | ||
1686 | Here are three miscellaneous @code{show} subcommands, all of which are | |
1687 | exceptional in lacking corresponding @code{set} commands: | |
1688 | ||
1689 | @table @code | |
1690 | @kindex show version | |
9c16f35a | 1691 | @cindex @value{GDBN} version number |
c906108c SS |
1692 | @item show version |
1693 | Show what version of @value{GDBN} is running. You should include this | |
2df3850c JM |
1694 | information in @value{GDBN} bug-reports. If multiple versions of |
1695 | @value{GDBN} are in use at your site, you may need to determine which | |
1696 | version of @value{GDBN} you are running; as @value{GDBN} evolves, new | |
1697 | commands are introduced, and old ones may wither away. Also, many | |
1698 | system vendors ship variant versions of @value{GDBN}, and there are | |
96a2c332 | 1699 | variant versions of @value{GDBN} in @sc{gnu}/Linux distributions as well. |
2df3850c JM |
1700 | The version number is the same as the one announced when you start |
1701 | @value{GDBN}. | |
c906108c SS |
1702 | |
1703 | @kindex show copying | |
09d4efe1 | 1704 | @kindex info copying |
9c16f35a | 1705 | @cindex display @value{GDBN} copyright |
c906108c | 1706 | @item show copying |
09d4efe1 | 1707 | @itemx info copying |
c906108c SS |
1708 | Display information about permission for copying @value{GDBN}. |
1709 | ||
1710 | @kindex show warranty | |
09d4efe1 | 1711 | @kindex info warranty |
c906108c | 1712 | @item show warranty |
09d4efe1 | 1713 | @itemx info warranty |
2df3850c | 1714 | Display the @sc{gnu} ``NO WARRANTY'' statement, or a warranty, |
96a2c332 | 1715 | if your version of @value{GDBN} comes with one. |
2df3850c | 1716 | |
c906108c SS |
1717 | @end table |
1718 | ||
6d2ebf8b | 1719 | @node Running |
c906108c SS |
1720 | @chapter Running Programs Under @value{GDBN} |
1721 | ||
1722 | When you run a program under @value{GDBN}, you must first generate | |
1723 | debugging information when you compile it. | |
7a292a7a SS |
1724 | |
1725 | You may start @value{GDBN} with its arguments, if any, in an environment | |
1726 | of your choice. If you are doing native debugging, you may redirect | |
1727 | your program's input and output, debug an already running process, or | |
1728 | kill a child process. | |
c906108c SS |
1729 | |
1730 | @menu | |
1731 | * Compilation:: Compiling for debugging | |
1732 | * Starting:: Starting your program | |
c906108c SS |
1733 | * Arguments:: Your program's arguments |
1734 | * Environment:: Your program's environment | |
c906108c SS |
1735 | |
1736 | * Working Directory:: Your program's working directory | |
1737 | * Input/Output:: Your program's input and output | |
1738 | * Attach:: Debugging an already-running process | |
1739 | * Kill Process:: Killing the child process | |
c906108c SS |
1740 | |
1741 | * Threads:: Debugging programs with multiple threads | |
1742 | * Processes:: Debugging programs with multiple processes | |
1743 | @end menu | |
1744 | ||
6d2ebf8b | 1745 | @node Compilation |
c906108c SS |
1746 | @section Compiling for debugging |
1747 | ||
1748 | In order to debug a program effectively, you need to generate | |
1749 | debugging information when you compile it. This debugging information | |
1750 | is stored in the object file; it describes the data type of each | |
1751 | variable or function and the correspondence between source line numbers | |
1752 | and addresses in the executable code. | |
1753 | ||
1754 | To request debugging information, specify the @samp{-g} option when you run | |
1755 | the compiler. | |
1756 | ||
514c4d71 EZ |
1757 | Programs that are to be shipped to your customers are compiled with |
1758 | optimizations, using the @samp{-O} compiler option. However, many | |
1759 | compilers are unable to handle the @samp{-g} and @samp{-O} options | |
1760 | together. Using those compilers, you cannot generate optimized | |
c906108c SS |
1761 | executables containing debugging information. |
1762 | ||
514c4d71 | 1763 | @value{NGCC}, the @sc{gnu} C/C@t{++} compiler, supports @samp{-g} with or |
53a5351d JM |
1764 | without @samp{-O}, making it possible to debug optimized code. We |
1765 | recommend that you @emph{always} use @samp{-g} whenever you compile a | |
1766 | program. You may think your program is correct, but there is no sense | |
1767 | in pushing your luck. | |
c906108c SS |
1768 | |
1769 | @cindex optimized code, debugging | |
1770 | @cindex debugging optimized code | |
1771 | When you debug a program compiled with @samp{-g -O}, remember that the | |
1772 | optimizer is rearranging your code; the debugger shows you what is | |
1773 | really there. Do not be too surprised when the execution path does not | |
1774 | exactly match your source file! An extreme example: if you define a | |
1775 | variable, but never use it, @value{GDBN} never sees that | |
1776 | variable---because the compiler optimizes it out of existence. | |
1777 | ||
1778 | Some things do not work as well with @samp{-g -O} as with just | |
1779 | @samp{-g}, particularly on machines with instruction scheduling. If in | |
1780 | doubt, recompile with @samp{-g} alone, and if this fixes the problem, | |
1781 | please report it to us as a bug (including a test case!). | |
15387254 | 1782 | @xref{Variables}, for more information about debugging optimized code. |
c906108c SS |
1783 | |
1784 | Older versions of the @sc{gnu} C compiler permitted a variant option | |
1785 | @w{@samp{-gg}} for debugging information. @value{GDBN} no longer supports this | |
1786 | format; if your @sc{gnu} C compiler has this option, do not use it. | |
1787 | ||
514c4d71 EZ |
1788 | @value{GDBN} knows about preprocessor macros and can show you their |
1789 | expansion (@pxref{Macros}). Most compilers do not include information | |
1790 | about preprocessor macros in the debugging information if you specify | |
1791 | the @option{-g} flag alone, because this information is rather large. | |
1792 | Version 3.1 and later of @value{NGCC}, the @sc{gnu} C compiler, | |
1793 | provides macro information if you specify the options | |
1794 | @option{-gdwarf-2} and @option{-g3}; the former option requests | |
1795 | debugging information in the Dwarf 2 format, and the latter requests | |
1796 | ``extra information''. In the future, we hope to find more compact | |
1797 | ways to represent macro information, so that it can be included with | |
1798 | @option{-g} alone. | |
1799 | ||
c906108c | 1800 | @need 2000 |
6d2ebf8b | 1801 | @node Starting |
c906108c SS |
1802 | @section Starting your program |
1803 | @cindex starting | |
1804 | @cindex running | |
1805 | ||
1806 | @table @code | |
1807 | @kindex run | |
41afff9a | 1808 | @kindex r @r{(@code{run})} |
c906108c SS |
1809 | @item run |
1810 | @itemx r | |
7a292a7a SS |
1811 | Use the @code{run} command to start your program under @value{GDBN}. |
1812 | You must first specify the program name (except on VxWorks) with an | |
1813 | argument to @value{GDBN} (@pxref{Invocation, ,Getting In and Out of | |
1814 | @value{GDBN}}), or by using the @code{file} or @code{exec-file} command | |
1815 | (@pxref{Files, ,Commands to specify files}). | |
c906108c SS |
1816 | |
1817 | @end table | |
1818 | ||
c906108c SS |
1819 | If you are running your program in an execution environment that |
1820 | supports processes, @code{run} creates an inferior process and makes | |
1821 | that process run your program. (In environments without processes, | |
1822 | @code{run} jumps to the start of your program.) | |
1823 | ||
1824 | The execution of a program is affected by certain information it | |
1825 | receives from its superior. @value{GDBN} provides ways to specify this | |
1826 | information, which you must do @emph{before} starting your program. (You | |
1827 | can change it after starting your program, but such changes only affect | |
1828 | your program the next time you start it.) This information may be | |
1829 | divided into four categories: | |
1830 | ||
1831 | @table @asis | |
1832 | @item The @emph{arguments.} | |
1833 | Specify the arguments to give your program as the arguments of the | |
1834 | @code{run} command. If a shell is available on your target, the shell | |
1835 | is used to pass the arguments, so that you may use normal conventions | |
1836 | (such as wildcard expansion or variable substitution) in describing | |
1837 | the arguments. | |
1838 | In Unix systems, you can control which shell is used with the | |
1839 | @code{SHELL} environment variable. | |
1840 | @xref{Arguments, ,Your program's arguments}. | |
1841 | ||
1842 | @item The @emph{environment.} | |
1843 | Your program normally inherits its environment from @value{GDBN}, but you can | |
1844 | use the @value{GDBN} commands @code{set environment} and @code{unset | |
1845 | environment} to change parts of the environment that affect | |
1846 | your program. @xref{Environment, ,Your program's environment}. | |
1847 | ||
1848 | @item The @emph{working directory.} | |
1849 | Your program inherits its working directory from @value{GDBN}. You can set | |
1850 | the @value{GDBN} working directory with the @code{cd} command in @value{GDBN}. | |
1851 | @xref{Working Directory, ,Your program's working directory}. | |
1852 | ||
1853 | @item The @emph{standard input and output.} | |
1854 | Your program normally uses the same device for standard input and | |
1855 | standard output as @value{GDBN} is using. You can redirect input and output | |
1856 | in the @code{run} command line, or you can use the @code{tty} command to | |
1857 | set a different device for your program. | |
1858 | @xref{Input/Output, ,Your program's input and output}. | |
1859 | ||
1860 | @cindex pipes | |
1861 | @emph{Warning:} While input and output redirection work, you cannot use | |
1862 | pipes to pass the output of the program you are debugging to another | |
1863 | program; if you attempt this, @value{GDBN} is likely to wind up debugging the | |
1864 | wrong program. | |
1865 | @end table | |
c906108c SS |
1866 | |
1867 | When you issue the @code{run} command, your program begins to execute | |
1868 | immediately. @xref{Stopping, ,Stopping and continuing}, for discussion | |
1869 | of how to arrange for your program to stop. Once your program has | |
1870 | stopped, you may call functions in your program, using the @code{print} | |
1871 | or @code{call} commands. @xref{Data, ,Examining Data}. | |
1872 | ||
1873 | If the modification time of your symbol file has changed since the last | |
1874 | time @value{GDBN} read its symbols, @value{GDBN} discards its symbol | |
1875 | table, and reads it again. When it does this, @value{GDBN} tries to retain | |
1876 | your current breakpoints. | |
1877 | ||
4e8b0763 JB |
1878 | @table @code |
1879 | @kindex start | |
1880 | @item start | |
1881 | @cindex run to main procedure | |
1882 | The name of the main procedure can vary from language to language. | |
1883 | With C or C@t{++}, the main procedure name is always @code{main}, but | |
1884 | other languages such as Ada do not require a specific name for their | |
1885 | main procedure. The debugger provides a convenient way to start the | |
1886 | execution of the program and to stop at the beginning of the main | |
1887 | procedure, depending on the language used. | |
1888 | ||
1889 | The @samp{start} command does the equivalent of setting a temporary | |
1890 | breakpoint at the beginning of the main procedure and then invoking | |
1891 | the @samp{run} command. | |
1892 | ||
f018e82f EZ |
1893 | @cindex elaboration phase |
1894 | Some programs contain an @dfn{elaboration} phase where some startup code is | |
1895 | executed before the main procedure is called. This depends on the | |
1896 | languages used to write your program. In C@t{++}, for instance, | |
4e8b0763 JB |
1897 | constructors for static and global objects are executed before |
1898 | @code{main} is called. It is therefore possible that the debugger stops | |
1899 | before reaching the main procedure. However, the temporary breakpoint | |
1900 | will remain to halt execution. | |
1901 | ||
1902 | Specify the arguments to give to your program as arguments to the | |
1903 | @samp{start} command. These arguments will be given verbatim to the | |
1904 | underlying @samp{run} command. Note that the same arguments will be | |
1905 | reused if no argument is provided during subsequent calls to | |
1906 | @samp{start} or @samp{run}. | |
1907 | ||
1908 | It is sometimes necessary to debug the program during elaboration. In | |
1909 | these cases, using the @code{start} command would stop the execution of | |
1910 | your program too late, as the program would have already completed the | |
1911 | elaboration phase. Under these circumstances, insert breakpoints in your | |
1912 | elaboration code before running your program. | |
1913 | @end table | |
1914 | ||
6d2ebf8b | 1915 | @node Arguments |
c906108c SS |
1916 | @section Your program's arguments |
1917 | ||
1918 | @cindex arguments (to your program) | |
1919 | The arguments to your program can be specified by the arguments of the | |
5d161b24 | 1920 | @code{run} command. |
c906108c SS |
1921 | They are passed to a shell, which expands wildcard characters and |
1922 | performs redirection of I/O, and thence to your program. Your | |
1923 | @code{SHELL} environment variable (if it exists) specifies what shell | |
1924 | @value{GDBN} uses. If you do not define @code{SHELL}, @value{GDBN} uses | |
d4f3574e SS |
1925 | the default shell (@file{/bin/sh} on Unix). |
1926 | ||
1927 | On non-Unix systems, the program is usually invoked directly by | |
1928 | @value{GDBN}, which emulates I/O redirection via the appropriate system | |
1929 | calls, and the wildcard characters are expanded by the startup code of | |
1930 | the program, not by the shell. | |
c906108c SS |
1931 | |
1932 | @code{run} with no arguments uses the same arguments used by the previous | |
1933 | @code{run}, or those set by the @code{set args} command. | |
1934 | ||
c906108c | 1935 | @table @code |
41afff9a | 1936 | @kindex set args |
c906108c SS |
1937 | @item set args |
1938 | Specify the arguments to be used the next time your program is run. If | |
1939 | @code{set args} has no arguments, @code{run} executes your program | |
1940 | with no arguments. Once you have run your program with arguments, | |
1941 | using @code{set args} before the next @code{run} is the only way to run | |
1942 | it again without arguments. | |
1943 | ||
1944 | @kindex show args | |
1945 | @item show args | |
1946 | Show the arguments to give your program when it is started. | |
1947 | @end table | |
1948 | ||
6d2ebf8b | 1949 | @node Environment |
c906108c SS |
1950 | @section Your program's environment |
1951 | ||
1952 | @cindex environment (of your program) | |
1953 | The @dfn{environment} consists of a set of environment variables and | |
1954 | their values. Environment variables conventionally record such things as | |
1955 | your user name, your home directory, your terminal type, and your search | |
1956 | path for programs to run. Usually you set up environment variables with | |
1957 | the shell and they are inherited by all the other programs you run. When | |
1958 | debugging, it can be useful to try running your program with a modified | |
1959 | environment without having to start @value{GDBN} over again. | |
1960 | ||
1961 | @table @code | |
1962 | @kindex path | |
1963 | @item path @var{directory} | |
1964 | Add @var{directory} to the front of the @code{PATH} environment variable | |
17cc6a06 EZ |
1965 | (the search path for executables) that will be passed to your program. |
1966 | The value of @code{PATH} used by @value{GDBN} does not change. | |
d4f3574e SS |
1967 | You may specify several directory names, separated by whitespace or by a |
1968 | system-dependent separator character (@samp{:} on Unix, @samp{;} on | |
1969 | MS-DOS and MS-Windows). If @var{directory} is already in the path, it | |
1970 | is moved to the front, so it is searched sooner. | |
c906108c SS |
1971 | |
1972 | You can use the string @samp{$cwd} to refer to whatever is the current | |
1973 | working directory at the time @value{GDBN} searches the path. If you | |
1974 | use @samp{.} instead, it refers to the directory where you executed the | |
1975 | @code{path} command. @value{GDBN} replaces @samp{.} in the | |
1976 | @var{directory} argument (with the current path) before adding | |
1977 | @var{directory} to the search path. | |
1978 | @c 'path' is explicitly nonrepeatable, but RMS points out it is silly to | |
1979 | @c document that, since repeating it would be a no-op. | |
1980 | ||
1981 | @kindex show paths | |
1982 | @item show paths | |
1983 | Display the list of search paths for executables (the @code{PATH} | |
1984 | environment variable). | |
1985 | ||
1986 | @kindex show environment | |
1987 | @item show environment @r{[}@var{varname}@r{]} | |
1988 | Print the value of environment variable @var{varname} to be given to | |
1989 | your program when it starts. If you do not supply @var{varname}, | |
1990 | print the names and values of all environment variables to be given to | |
1991 | your program. You can abbreviate @code{environment} as @code{env}. | |
1992 | ||
1993 | @kindex set environment | |
53a5351d | 1994 | @item set environment @var{varname} @r{[}=@var{value}@r{]} |
c906108c SS |
1995 | Set environment variable @var{varname} to @var{value}. The value |
1996 | changes for your program only, not for @value{GDBN} itself. @var{value} may | |
1997 | be any string; the values of environment variables are just strings, and | |
1998 | any interpretation is supplied by your program itself. The @var{value} | |
1999 | parameter is optional; if it is eliminated, the variable is set to a | |
2000 | null value. | |
2001 | @c "any string" here does not include leading, trailing | |
2002 | @c blanks. Gnu asks: does anyone care? | |
2003 | ||
2004 | For example, this command: | |
2005 | ||
474c8240 | 2006 | @smallexample |
c906108c | 2007 | set env USER = foo |
474c8240 | 2008 | @end smallexample |
c906108c SS |
2009 | |
2010 | @noindent | |
d4f3574e | 2011 | tells the debugged program, when subsequently run, that its user is named |
c906108c SS |
2012 | @samp{foo}. (The spaces around @samp{=} are used for clarity here; they |
2013 | are not actually required.) | |
2014 | ||
2015 | @kindex unset environment | |
2016 | @item unset environment @var{varname} | |
2017 | Remove variable @var{varname} from the environment to be passed to your | |
2018 | program. This is different from @samp{set env @var{varname} =}; | |
2019 | @code{unset environment} removes the variable from the environment, | |
2020 | rather than assigning it an empty value. | |
2021 | @end table | |
2022 | ||
d4f3574e SS |
2023 | @emph{Warning:} On Unix systems, @value{GDBN} runs your program using |
2024 | the shell indicated | |
c906108c SS |
2025 | by your @code{SHELL} environment variable if it exists (or |
2026 | @code{/bin/sh} if not). If your @code{SHELL} variable names a shell | |
2027 | that runs an initialization file---such as @file{.cshrc} for C-shell, or | |
2028 | @file{.bashrc} for BASH---any variables you set in that file affect | |
2029 | your program. You may wish to move setting of environment variables to | |
2030 | files that are only run when you sign on, such as @file{.login} or | |
2031 | @file{.profile}. | |
2032 | ||
6d2ebf8b | 2033 | @node Working Directory |
c906108c SS |
2034 | @section Your program's working directory |
2035 | ||
2036 | @cindex working directory (of your program) | |
2037 | Each time you start your program with @code{run}, it inherits its | |
2038 | working directory from the current working directory of @value{GDBN}. | |
2039 | The @value{GDBN} working directory is initially whatever it inherited | |
2040 | from its parent process (typically the shell), but you can specify a new | |
2041 | working directory in @value{GDBN} with the @code{cd} command. | |
2042 | ||
2043 | The @value{GDBN} working directory also serves as a default for the commands | |
2044 | that specify files for @value{GDBN} to operate on. @xref{Files, ,Commands to | |
2045 | specify files}. | |
2046 | ||
2047 | @table @code | |
2048 | @kindex cd | |
721c2651 | 2049 | @cindex change working directory |
c906108c SS |
2050 | @item cd @var{directory} |
2051 | Set the @value{GDBN} working directory to @var{directory}. | |
2052 | ||
2053 | @kindex pwd | |
2054 | @item pwd | |
2055 | Print the @value{GDBN} working directory. | |
2056 | @end table | |
2057 | ||
60bf7e09 EZ |
2058 | It is generally impossible to find the current working directory of |
2059 | the process being debugged (since a program can change its directory | |
2060 | during its run). If you work on a system where @value{GDBN} is | |
2061 | configured with the @file{/proc} support, you can use the @code{info | |
2062 | proc} command (@pxref{SVR4 Process Information}) to find out the | |
2063 | current working directory of the debuggee. | |
2064 | ||
6d2ebf8b | 2065 | @node Input/Output |
c906108c SS |
2066 | @section Your program's input and output |
2067 | ||
2068 | @cindex redirection | |
2069 | @cindex i/o | |
2070 | @cindex terminal | |
2071 | By default, the program you run under @value{GDBN} does input and output to | |
5d161b24 | 2072 | the same terminal that @value{GDBN} uses. @value{GDBN} switches the terminal |
c906108c SS |
2073 | to its own terminal modes to interact with you, but it records the terminal |
2074 | modes your program was using and switches back to them when you continue | |
2075 | running your program. | |
2076 | ||
2077 | @table @code | |
2078 | @kindex info terminal | |
2079 | @item info terminal | |
2080 | Displays information recorded by @value{GDBN} about the terminal modes your | |
2081 | program is using. | |
2082 | @end table | |
2083 | ||
2084 | You can redirect your program's input and/or output using shell | |
2085 | redirection with the @code{run} command. For example, | |
2086 | ||
474c8240 | 2087 | @smallexample |
c906108c | 2088 | run > outfile |
474c8240 | 2089 | @end smallexample |
c906108c SS |
2090 | |
2091 | @noindent | |
2092 | starts your program, diverting its output to the file @file{outfile}. | |
2093 | ||
2094 | @kindex tty | |
2095 | @cindex controlling terminal | |
2096 | Another way to specify where your program should do input and output is | |
2097 | with the @code{tty} command. This command accepts a file name as | |
2098 | argument, and causes this file to be the default for future @code{run} | |
2099 | commands. It also resets the controlling terminal for the child | |
2100 | process, for future @code{run} commands. For example, | |
2101 | ||
474c8240 | 2102 | @smallexample |
c906108c | 2103 | tty /dev/ttyb |
474c8240 | 2104 | @end smallexample |
c906108c SS |
2105 | |
2106 | @noindent | |
2107 | directs that processes started with subsequent @code{run} commands | |
2108 | default to do input and output on the terminal @file{/dev/ttyb} and have | |
2109 | that as their controlling terminal. | |
2110 | ||
2111 | An explicit redirection in @code{run} overrides the @code{tty} command's | |
2112 | effect on the input/output device, but not its effect on the controlling | |
2113 | terminal. | |
2114 | ||
2115 | When you use the @code{tty} command or redirect input in the @code{run} | |
2116 | command, only the input @emph{for your program} is affected. The input | |
3cb3b8df BR |
2117 | for @value{GDBN} still comes from your terminal. @code{tty} is an alias |
2118 | for @code{set inferior-tty}. | |
2119 | ||
2120 | @cindex inferior tty | |
2121 | @cindex set inferior controlling terminal | |
2122 | You can use the @code{show inferior-tty} command to tell @value{GDBN} to | |
2123 | display the name of the terminal that will be used for future runs of your | |
2124 | program. | |
2125 | ||
2126 | @table @code | |
2127 | @item set inferior-tty /dev/ttyb | |
2128 | @kindex set inferior-tty | |
2129 | Set the tty for the program being debugged to /dev/ttyb. | |
2130 | ||
2131 | @item show inferior-tty | |
2132 | @kindex show inferior-tty | |
2133 | Show the current tty for the program being debugged. | |
2134 | @end table | |
c906108c | 2135 | |
6d2ebf8b | 2136 | @node Attach |
c906108c SS |
2137 | @section Debugging an already-running process |
2138 | @kindex attach | |
2139 | @cindex attach | |
2140 | ||
2141 | @table @code | |
2142 | @item attach @var{process-id} | |
2143 | This command attaches to a running process---one that was started | |
2144 | outside @value{GDBN}. (@code{info files} shows your active | |
2145 | targets.) The command takes as argument a process ID. The usual way to | |
09d4efe1 | 2146 | find out the @var{process-id} of a Unix process is with the @code{ps} utility, |
c906108c SS |
2147 | or with the @samp{jobs -l} shell command. |
2148 | ||
2149 | @code{attach} does not repeat if you press @key{RET} a second time after | |
2150 | executing the command. | |
2151 | @end table | |
2152 | ||
2153 | To use @code{attach}, your program must be running in an environment | |
2154 | which supports processes; for example, @code{attach} does not work for | |
2155 | programs on bare-board targets that lack an operating system. You must | |
2156 | also have permission to send the process a signal. | |
2157 | ||
2158 | When you use @code{attach}, the debugger finds the program running in | |
2159 | the process first by looking in the current working directory, then (if | |
2160 | the program is not found) by using the source file search path | |
2161 | (@pxref{Source Path, ,Specifying source directories}). You can also use | |
2162 | the @code{file} command to load the program. @xref{Files, ,Commands to | |
2163 | Specify Files}. | |
2164 | ||
2165 | The first thing @value{GDBN} does after arranging to debug the specified | |
2166 | process is to stop it. You can examine and modify an attached process | |
53a5351d JM |
2167 | with all the @value{GDBN} commands that are ordinarily available when |
2168 | you start processes with @code{run}. You can insert breakpoints; you | |
2169 | can step and continue; you can modify storage. If you would rather the | |
2170 | process continue running, you may use the @code{continue} command after | |
c906108c SS |
2171 | attaching @value{GDBN} to the process. |
2172 | ||
2173 | @table @code | |
2174 | @kindex detach | |
2175 | @item detach | |
2176 | When you have finished debugging the attached process, you can use the | |
2177 | @code{detach} command to release it from @value{GDBN} control. Detaching | |
2178 | the process continues its execution. After the @code{detach} command, | |
2179 | that process and @value{GDBN} become completely independent once more, and you | |
2180 | are ready to @code{attach} another process or start one with @code{run}. | |
2181 | @code{detach} does not repeat if you press @key{RET} again after | |
2182 | executing the command. | |
2183 | @end table | |
2184 | ||
2185 | If you exit @value{GDBN} or use the @code{run} command while you have an | |
2186 | attached process, you kill that process. By default, @value{GDBN} asks | |
2187 | for confirmation if you try to do either of these things; you can | |
2188 | control whether or not you need to confirm by using the @code{set | |
2189 | confirm} command (@pxref{Messages/Warnings, ,Optional warnings and | |
2190 | messages}). | |
2191 | ||
6d2ebf8b | 2192 | @node Kill Process |
c906108c | 2193 | @section Killing the child process |
c906108c SS |
2194 | |
2195 | @table @code | |
2196 | @kindex kill | |
2197 | @item kill | |
2198 | Kill the child process in which your program is running under @value{GDBN}. | |
2199 | @end table | |
2200 | ||
2201 | This command is useful if you wish to debug a core dump instead of a | |
2202 | running process. @value{GDBN} ignores any core dump file while your program | |
2203 | is running. | |
2204 | ||
2205 | On some operating systems, a program cannot be executed outside @value{GDBN} | |
2206 | while you have breakpoints set on it inside @value{GDBN}. You can use the | |
2207 | @code{kill} command in this situation to permit running your program | |
2208 | outside the debugger. | |
2209 | ||
2210 | The @code{kill} command is also useful if you wish to recompile and | |
2211 | relink your program, since on many systems it is impossible to modify an | |
2212 | executable file while it is running in a process. In this case, when you | |
2213 | next type @code{run}, @value{GDBN} notices that the file has changed, and | |
2214 | reads the symbol table again (while trying to preserve your current | |
2215 | breakpoint settings). | |
2216 | ||
6d2ebf8b | 2217 | @node Threads |
c906108c | 2218 | @section Debugging programs with multiple threads |
c906108c SS |
2219 | |
2220 | @cindex threads of execution | |
2221 | @cindex multiple threads | |
2222 | @cindex switching threads | |
2223 | In some operating systems, such as HP-UX and Solaris, a single program | |
2224 | may have more than one @dfn{thread} of execution. The precise semantics | |
2225 | of threads differ from one operating system to another, but in general | |
2226 | the threads of a single program are akin to multiple processes---except | |
2227 | that they share one address space (that is, they can all examine and | |
2228 | modify the same variables). On the other hand, each thread has its own | |
2229 | registers and execution stack, and perhaps private memory. | |
2230 | ||
2231 | @value{GDBN} provides these facilities for debugging multi-thread | |
2232 | programs: | |
2233 | ||
2234 | @itemize @bullet | |
2235 | @item automatic notification of new threads | |
2236 | @item @samp{thread @var{threadno}}, a command to switch among threads | |
2237 | @item @samp{info threads}, a command to inquire about existing threads | |
5d161b24 | 2238 | @item @samp{thread apply [@var{threadno}] [@var{all}] @var{args}}, |
c906108c SS |
2239 | a command to apply a command to a list of threads |
2240 | @item thread-specific breakpoints | |
2241 | @end itemize | |
2242 | ||
c906108c SS |
2243 | @quotation |
2244 | @emph{Warning:} These facilities are not yet available on every | |
2245 | @value{GDBN} configuration where the operating system supports threads. | |
2246 | If your @value{GDBN} does not support threads, these commands have no | |
2247 | effect. For example, a system without thread support shows no output | |
2248 | from @samp{info threads}, and always rejects the @code{thread} command, | |
2249 | like this: | |
2250 | ||
2251 | @smallexample | |
2252 | (@value{GDBP}) info threads | |
2253 | (@value{GDBP}) thread 1 | |
2254 | Thread ID 1 not known. Use the "info threads" command to | |
2255 | see the IDs of currently known threads. | |
2256 | @end smallexample | |
2257 | @c FIXME to implementors: how hard would it be to say "sorry, this GDB | |
2258 | @c doesn't support threads"? | |
2259 | @end quotation | |
c906108c SS |
2260 | |
2261 | @cindex focus of debugging | |
2262 | @cindex current thread | |
2263 | The @value{GDBN} thread debugging facility allows you to observe all | |
2264 | threads while your program runs---but whenever @value{GDBN} takes | |
2265 | control, one thread in particular is always the focus of debugging. | |
2266 | This thread is called the @dfn{current thread}. Debugging commands show | |
2267 | program information from the perspective of the current thread. | |
2268 | ||
41afff9a | 2269 | @cindex @code{New} @var{systag} message |
c906108c SS |
2270 | @cindex thread identifier (system) |
2271 | @c FIXME-implementors!! It would be more helpful if the [New...] message | |
2272 | @c included GDB's numeric thread handle, so you could just go to that | |
2273 | @c thread without first checking `info threads'. | |
2274 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2275 | the target system's identification for the thread with a message in the | |
2276 | form @samp{[New @var{systag}]}. @var{systag} is a thread identifier | |
2277 | whose form varies depending on the particular system. For example, on | |
2278 | LynxOS, you might see | |
2279 | ||
474c8240 | 2280 | @smallexample |
c906108c | 2281 | [New process 35 thread 27] |
474c8240 | 2282 | @end smallexample |
c906108c SS |
2283 | |
2284 | @noindent | |
2285 | when @value{GDBN} notices a new thread. In contrast, on an SGI system, | |
2286 | the @var{systag} is simply something like @samp{process 368}, with no | |
2287 | further qualifier. | |
2288 | ||
2289 | @c FIXME!! (1) Does the [New...] message appear even for the very first | |
2290 | @c thread of a program, or does it only appear for the | |
6ca652b0 | 2291 | @c second---i.e.@: when it becomes obvious we have a multithread |
c906108c SS |
2292 | @c program? |
2293 | @c (2) *Is* there necessarily a first thread always? Or do some | |
2294 | @c multithread systems permit starting a program with multiple | |
5d161b24 | 2295 | @c threads ab initio? |
c906108c SS |
2296 | |
2297 | @cindex thread number | |
2298 | @cindex thread identifier (GDB) | |
2299 | For debugging purposes, @value{GDBN} associates its own thread | |
2300 | number---always a single integer---with each thread in your program. | |
2301 | ||
2302 | @table @code | |
2303 | @kindex info threads | |
2304 | @item info threads | |
2305 | Display a summary of all threads currently in your | |
2306 | program. @value{GDBN} displays for each thread (in this order): | |
2307 | ||
2308 | @enumerate | |
09d4efe1 EZ |
2309 | @item |
2310 | the thread number assigned by @value{GDBN} | |
c906108c | 2311 | |
09d4efe1 EZ |
2312 | @item |
2313 | the target system's thread identifier (@var{systag}) | |
c906108c | 2314 | |
09d4efe1 EZ |
2315 | @item |
2316 | the current stack frame summary for that thread | |
c906108c SS |
2317 | @end enumerate |
2318 | ||
2319 | @noindent | |
2320 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
2321 | indicates the current thread. | |
2322 | ||
5d161b24 | 2323 | For example, |
c906108c SS |
2324 | @end table |
2325 | @c end table here to get a little more width for example | |
2326 | ||
2327 | @smallexample | |
2328 | (@value{GDBP}) info threads | |
2329 | 3 process 35 thread 27 0x34e5 in sigpause () | |
2330 | 2 process 35 thread 23 0x34e5 in sigpause () | |
2331 | * 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) | |
2332 | at threadtest.c:68 | |
2333 | @end smallexample | |
53a5351d JM |
2334 | |
2335 | On HP-UX systems: | |
c906108c | 2336 | |
4644b6e3 EZ |
2337 | @cindex debugging multithreaded programs (on HP-UX) |
2338 | @cindex thread identifier (GDB), on HP-UX | |
c906108c SS |
2339 | For debugging purposes, @value{GDBN} associates its own thread |
2340 | number---a small integer assigned in thread-creation order---with each | |
2341 | thread in your program. | |
2342 | ||
41afff9a EZ |
2343 | @cindex @code{New} @var{systag} message, on HP-UX |
2344 | @cindex thread identifier (system), on HP-UX | |
c906108c SS |
2345 | @c FIXME-implementors!! It would be more helpful if the [New...] message |
2346 | @c included GDB's numeric thread handle, so you could just go to that | |
2347 | @c thread without first checking `info threads'. | |
2348 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2349 | both @value{GDBN}'s thread number and the target system's identification for the thread with a message in the | |
2350 | form @samp{[New @var{systag}]}. @var{systag} is a thread identifier | |
2351 | whose form varies depending on the particular system. For example, on | |
2352 | HP-UX, you see | |
2353 | ||
474c8240 | 2354 | @smallexample |
c906108c | 2355 | [New thread 2 (system thread 26594)] |
474c8240 | 2356 | @end smallexample |
c906108c SS |
2357 | |
2358 | @noindent | |
5d161b24 | 2359 | when @value{GDBN} notices a new thread. |
c906108c SS |
2360 | |
2361 | @table @code | |
4644b6e3 | 2362 | @kindex info threads (HP-UX) |
c906108c SS |
2363 | @item info threads |
2364 | Display a summary of all threads currently in your | |
2365 | program. @value{GDBN} displays for each thread (in this order): | |
2366 | ||
2367 | @enumerate | |
2368 | @item the thread number assigned by @value{GDBN} | |
2369 | ||
2370 | @item the target system's thread identifier (@var{systag}) | |
2371 | ||
2372 | @item the current stack frame summary for that thread | |
2373 | @end enumerate | |
2374 | ||
2375 | @noindent | |
2376 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
2377 | indicates the current thread. | |
2378 | ||
5d161b24 | 2379 | For example, |
c906108c SS |
2380 | @end table |
2381 | @c end table here to get a little more width for example | |
2382 | ||
474c8240 | 2383 | @smallexample |
c906108c | 2384 | (@value{GDBP}) info threads |
6d2ebf8b SS |
2385 | * 3 system thread 26607 worker (wptr=0x7b09c318 "@@") \@* |
2386 | at quicksort.c:137 | |
2387 | 2 system thread 26606 0x7b0030d8 in __ksleep () \@* | |
2388 | from /usr/lib/libc.2 | |
2389 | 1 system thread 27905 0x7b003498 in _brk () \@* | |
2390 | from /usr/lib/libc.2 | |
474c8240 | 2391 | @end smallexample |
c906108c | 2392 | |
c45da7e6 EZ |
2393 | On Solaris, you can display more information about user threads with a |
2394 | Solaris-specific command: | |
2395 | ||
2396 | @table @code | |
2397 | @item maint info sol-threads | |
2398 | @kindex maint info sol-threads | |
2399 | @cindex thread info (Solaris) | |
2400 | Display info on Solaris user threads. | |
2401 | @end table | |
2402 | ||
c906108c SS |
2403 | @table @code |
2404 | @kindex thread @var{threadno} | |
2405 | @item thread @var{threadno} | |
2406 | Make thread number @var{threadno} the current thread. The command | |
2407 | argument @var{threadno} is the internal @value{GDBN} thread number, as | |
2408 | shown in the first field of the @samp{info threads} display. | |
2409 | @value{GDBN} responds by displaying the system identifier of the thread | |
2410 | you selected, and its current stack frame summary: | |
2411 | ||
2412 | @smallexample | |
2413 | @c FIXME!! This example made up; find a @value{GDBN} w/threads and get real one | |
2414 | (@value{GDBP}) thread 2 | |
c906108c | 2415 | [Switching to process 35 thread 23] |
c906108c SS |
2416 | 0x34e5 in sigpause () |
2417 | @end smallexample | |
2418 | ||
2419 | @noindent | |
2420 | As with the @samp{[New @dots{}]} message, the form of the text after | |
2421 | @samp{Switching to} depends on your system's conventions for identifying | |
5d161b24 | 2422 | threads. |
c906108c | 2423 | |
9c16f35a | 2424 | @kindex thread apply |
638ac427 | 2425 | @cindex apply command to several threads |
c906108c SS |
2426 | @item thread apply [@var{threadno}] [@var{all}] @var{args} |
2427 | The @code{thread apply} command allows you to apply a command to one or | |
2428 | more threads. Specify the numbers of the threads that you want affected | |
2429 | with the command argument @var{threadno}. @var{threadno} is the internal | |
2430 | @value{GDBN} thread number, as shown in the first field of the @samp{info | |
5d161b24 DB |
2431 | threads} display. To apply a command to all threads, use |
2432 | @code{thread apply all} @var{args}. | |
c906108c SS |
2433 | @end table |
2434 | ||
2435 | @cindex automatic thread selection | |
2436 | @cindex switching threads automatically | |
2437 | @cindex threads, automatic switching | |
2438 | Whenever @value{GDBN} stops your program, due to a breakpoint or a | |
2439 | signal, it automatically selects the thread where that breakpoint or | |
2440 | signal happened. @value{GDBN} alerts you to the context switch with a | |
2441 | message of the form @samp{[Switching to @var{systag}]} to identify the | |
2442 | thread. | |
2443 | ||
2444 | @xref{Thread Stops,,Stopping and starting multi-thread programs}, for | |
2445 | more information about how @value{GDBN} behaves when you stop and start | |
2446 | programs with multiple threads. | |
2447 | ||
2448 | @xref{Set Watchpoints,,Setting watchpoints}, for information about | |
2449 | watchpoints in programs with multiple threads. | |
c906108c | 2450 | |
6d2ebf8b | 2451 | @node Processes |
c906108c SS |
2452 | @section Debugging programs with multiple processes |
2453 | ||
2454 | @cindex fork, debugging programs which call | |
2455 | @cindex multiple processes | |
2456 | @cindex processes, multiple | |
53a5351d JM |
2457 | On most systems, @value{GDBN} has no special support for debugging |
2458 | programs which create additional processes using the @code{fork} | |
2459 | function. When a program forks, @value{GDBN} will continue to debug the | |
2460 | parent process and the child process will run unimpeded. If you have | |
2461 | set a breakpoint in any code which the child then executes, the child | |
2462 | will get a @code{SIGTRAP} signal which (unless it catches the signal) | |
2463 | will cause it to terminate. | |
c906108c SS |
2464 | |
2465 | However, if you want to debug the child process there is a workaround | |
2466 | which isn't too painful. Put a call to @code{sleep} in the code which | |
2467 | the child process executes after the fork. It may be useful to sleep | |
2468 | only if a certain environment variable is set, or a certain file exists, | |
2469 | so that the delay need not occur when you don't want to run @value{GDBN} | |
2470 | on the child. While the child is sleeping, use the @code{ps} program to | |
2471 | get its process ID. Then tell @value{GDBN} (a new invocation of | |
2472 | @value{GDBN} if you are also debugging the parent process) to attach to | |
d4f3574e | 2473 | the child process (@pxref{Attach}). From that point on you can debug |
c906108c | 2474 | the child process just like any other process which you attached to. |
c906108c | 2475 | |
b51970ac DJ |
2476 | On some systems, @value{GDBN} provides support for debugging programs that |
2477 | create additional processes using the @code{fork} or @code{vfork} functions. | |
2478 | Currently, the only platforms with this feature are HP-UX (11.x and later | |
2479 | only?) and GNU/Linux (kernel version 2.5.60 and later). | |
c906108c SS |
2480 | |
2481 | By default, when a program forks, @value{GDBN} will continue to debug | |
2482 | the parent process and the child process will run unimpeded. | |
2483 | ||
2484 | If you want to follow the child process instead of the parent process, | |
2485 | use the command @w{@code{set follow-fork-mode}}. | |
2486 | ||
2487 | @table @code | |
2488 | @kindex set follow-fork-mode | |
2489 | @item set follow-fork-mode @var{mode} | |
2490 | Set the debugger response to a program call of @code{fork} or | |
2491 | @code{vfork}. A call to @code{fork} or @code{vfork} creates a new | |
9c16f35a | 2492 | process. The @var{mode} argument can be: |
c906108c SS |
2493 | |
2494 | @table @code | |
2495 | @item parent | |
2496 | The original process is debugged after a fork. The child process runs | |
2df3850c | 2497 | unimpeded. This is the default. |
c906108c SS |
2498 | |
2499 | @item child | |
2500 | The new process is debugged after a fork. The parent process runs | |
2501 | unimpeded. | |
2502 | ||
c906108c SS |
2503 | @end table |
2504 | ||
9c16f35a | 2505 | @kindex show follow-fork-mode |
c906108c | 2506 | @item show follow-fork-mode |
2df3850c | 2507 | Display the current debugger response to a @code{fork} or @code{vfork} call. |
c906108c SS |
2508 | @end table |
2509 | ||
2510 | If you ask to debug a child process and a @code{vfork} is followed by an | |
2511 | @code{exec}, @value{GDBN} executes the new target up to the first | |
2512 | breakpoint in the new target. If you have a breakpoint set on | |
2513 | @code{main} in your original program, the breakpoint will also be set on | |
2514 | the child process's @code{main}. | |
2515 | ||
2516 | When a child process is spawned by @code{vfork}, you cannot debug the | |
2517 | child or parent until an @code{exec} call completes. | |
2518 | ||
2519 | If you issue a @code{run} command to @value{GDBN} after an @code{exec} | |
2520 | call executes, the new target restarts. To restart the parent process, | |
2521 | use the @code{file} command with the parent executable name as its | |
2522 | argument. | |
2523 | ||
2524 | You can use the @code{catch} command to make @value{GDBN} stop whenever | |
2525 | a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set | |
2526 | Catchpoints, ,Setting catchpoints}. | |
c906108c | 2527 | |
6d2ebf8b | 2528 | @node Stopping |
c906108c SS |
2529 | @chapter Stopping and Continuing |
2530 | ||
2531 | The principal purposes of using a debugger are so that you can stop your | |
2532 | program before it terminates; or so that, if your program runs into | |
2533 | trouble, you can investigate and find out why. | |
2534 | ||
7a292a7a SS |
2535 | Inside @value{GDBN}, your program may stop for any of several reasons, |
2536 | such as a signal, a breakpoint, or reaching a new line after a | |
2537 | @value{GDBN} command such as @code{step}. You may then examine and | |
2538 | change variables, set new breakpoints or remove old ones, and then | |
2539 | continue execution. Usually, the messages shown by @value{GDBN} provide | |
2540 | ample explanation of the status of your program---but you can also | |
2541 | explicitly request this information at any time. | |
c906108c SS |
2542 | |
2543 | @table @code | |
2544 | @kindex info program | |
2545 | @item info program | |
2546 | Display information about the status of your program: whether it is | |
7a292a7a | 2547 | running or not, what process it is, and why it stopped. |
c906108c SS |
2548 | @end table |
2549 | ||
2550 | @menu | |
2551 | * Breakpoints:: Breakpoints, watchpoints, and catchpoints | |
2552 | * Continuing and Stepping:: Resuming execution | |
c906108c | 2553 | * Signals:: Signals |
c906108c | 2554 | * Thread Stops:: Stopping and starting multi-thread programs |
c906108c SS |
2555 | @end menu |
2556 | ||
6d2ebf8b | 2557 | @node Breakpoints |
c906108c SS |
2558 | @section Breakpoints, watchpoints, and catchpoints |
2559 | ||
2560 | @cindex breakpoints | |
2561 | A @dfn{breakpoint} makes your program stop whenever a certain point in | |
2562 | the program is reached. For each breakpoint, you can add conditions to | |
2563 | control in finer detail whether your program stops. You can set | |
2564 | breakpoints with the @code{break} command and its variants (@pxref{Set | |
2565 | Breaks, ,Setting breakpoints}), to specify the place where your program | |
2566 | should stop by line number, function name or exact address in the | |
2567 | program. | |
2568 | ||
09d4efe1 EZ |
2569 | On some systems, you can set breakpoints in shared libraries before |
2570 | the executable is run. There is a minor limitation on HP-UX systems: | |
2571 | you must wait until the executable is run in order to set breakpoints | |
2572 | in shared library routines that are not called directly by the program | |
2573 | (for example, routines that are arguments in a @code{pthread_create} | |
2574 | call). | |
c906108c SS |
2575 | |
2576 | @cindex watchpoints | |
2577 | @cindex memory tracing | |
2578 | @cindex breakpoint on memory address | |
2579 | @cindex breakpoint on variable modification | |
2580 | A @dfn{watchpoint} is a special breakpoint that stops your program | |
2581 | when the value of an expression changes. You must use a different | |
2582 | command to set watchpoints (@pxref{Set Watchpoints, ,Setting | |
2583 | watchpoints}), but aside from that, you can manage a watchpoint like | |
2584 | any other breakpoint: you enable, disable, and delete both breakpoints | |
2585 | and watchpoints using the same commands. | |
2586 | ||
2587 | You can arrange to have values from your program displayed automatically | |
2588 | whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,, | |
2589 | Automatic display}. | |
2590 | ||
2591 | @cindex catchpoints | |
2592 | @cindex breakpoint on events | |
2593 | A @dfn{catchpoint} is another special breakpoint that stops your program | |
b37052ae | 2594 | when a certain kind of event occurs, such as the throwing of a C@t{++} |
c906108c SS |
2595 | exception or the loading of a library. As with watchpoints, you use a |
2596 | different command to set a catchpoint (@pxref{Set Catchpoints, ,Setting | |
2597 | catchpoints}), but aside from that, you can manage a catchpoint like any | |
2598 | other breakpoint. (To stop when your program receives a signal, use the | |
d4f3574e | 2599 | @code{handle} command; see @ref{Signals, ,Signals}.) |
c906108c SS |
2600 | |
2601 | @cindex breakpoint numbers | |
2602 | @cindex numbers for breakpoints | |
2603 | @value{GDBN} assigns a number to each breakpoint, watchpoint, or | |
2604 | catchpoint when you create it; these numbers are successive integers | |
2605 | starting with one. In many of the commands for controlling various | |
2606 | features of breakpoints you use the breakpoint number to say which | |
2607 | breakpoint you want to change. Each breakpoint may be @dfn{enabled} or | |
2608 | @dfn{disabled}; if disabled, it has no effect on your program until you | |
2609 | enable it again. | |
2610 | ||
c5394b80 JM |
2611 | @cindex breakpoint ranges |
2612 | @cindex ranges of breakpoints | |
2613 | Some @value{GDBN} commands accept a range of breakpoints on which to | |
2614 | operate. A breakpoint range is either a single breakpoint number, like | |
2615 | @samp{5}, or two such numbers, in increasing order, separated by a | |
2616 | hyphen, like @samp{5-7}. When a breakpoint range is given to a command, | |
2617 | all breakpoint in that range are operated on. | |
2618 | ||
c906108c SS |
2619 | @menu |
2620 | * Set Breaks:: Setting breakpoints | |
2621 | * Set Watchpoints:: Setting watchpoints | |
2622 | * Set Catchpoints:: Setting catchpoints | |
2623 | * Delete Breaks:: Deleting breakpoints | |
2624 | * Disabling:: Disabling breakpoints | |
2625 | * Conditions:: Break conditions | |
2626 | * Break Commands:: Breakpoint command lists | |
c906108c | 2627 | * Breakpoint Menus:: Breakpoint menus |
d4f3574e | 2628 | * Error in Breakpoints:: ``Cannot insert breakpoints'' |
e4d5f7e1 | 2629 | * Breakpoint related warnings:: ``Breakpoint address adjusted...'' |
c906108c SS |
2630 | @end menu |
2631 | ||
6d2ebf8b | 2632 | @node Set Breaks |
c906108c SS |
2633 | @subsection Setting breakpoints |
2634 | ||
5d161b24 | 2635 | @c FIXME LMB what does GDB do if no code on line of breakpt? |
c906108c SS |
2636 | @c consider in particular declaration with/without initialization. |
2637 | @c | |
2638 | @c FIXME 2 is there stuff on this already? break at fun start, already init? | |
2639 | ||
2640 | @kindex break | |
41afff9a EZ |
2641 | @kindex b @r{(@code{break})} |
2642 | @vindex $bpnum@r{, convenience variable} | |
c906108c SS |
2643 | @cindex latest breakpoint |
2644 | Breakpoints are set with the @code{break} command (abbreviated | |
5d161b24 | 2645 | @code{b}). The debugger convenience variable @samp{$bpnum} records the |
f3b28801 | 2646 | number of the breakpoint you've set most recently; see @ref{Convenience |
c906108c SS |
2647 | Vars,, Convenience variables}, for a discussion of what you can do with |
2648 | convenience variables. | |
2649 | ||
2650 | You have several ways to say where the breakpoint should go. | |
2651 | ||
2652 | @table @code | |
2653 | @item break @var{function} | |
5d161b24 | 2654 | Set a breakpoint at entry to function @var{function}. |
c906108c | 2655 | When using source languages that permit overloading of symbols, such as |
b37052ae | 2656 | C@t{++}, @var{function} may refer to more than one possible place to break. |
c906108c | 2657 | @xref{Breakpoint Menus,,Breakpoint menus}, for a discussion of that situation. |
c906108c SS |
2658 | |
2659 | @item break +@var{offset} | |
2660 | @itemx break -@var{offset} | |
2661 | Set a breakpoint some number of lines forward or back from the position | |
d4f3574e | 2662 | at which execution stopped in the currently selected @dfn{stack frame}. |
2df3850c | 2663 | (@xref{Frames, ,Frames}, for a description of stack frames.) |
c906108c SS |
2664 | |
2665 | @item break @var{linenum} | |
2666 | Set a breakpoint at line @var{linenum} in the current source file. | |
d4f3574e SS |
2667 | The current source file is the last file whose source text was printed. |
2668 | The breakpoint will stop your program just before it executes any of the | |
c906108c SS |
2669 | code on that line. |
2670 | ||
2671 | @item break @var{filename}:@var{linenum} | |
2672 | Set a breakpoint at line @var{linenum} in source file @var{filename}. | |
2673 | ||
2674 | @item break @var{filename}:@var{function} | |
2675 | Set a breakpoint at entry to function @var{function} found in file | |
2676 | @var{filename}. Specifying a file name as well as a function name is | |
2677 | superfluous except when multiple files contain similarly named | |
2678 | functions. | |
2679 | ||
2680 | @item break *@var{address} | |
2681 | Set a breakpoint at address @var{address}. You can use this to set | |
2682 | breakpoints in parts of your program which do not have debugging | |
2683 | information or source files. | |
2684 | ||
2685 | @item break | |
2686 | When called without any arguments, @code{break} sets a breakpoint at | |
2687 | the next instruction to be executed in the selected stack frame | |
2688 | (@pxref{Stack, ,Examining the Stack}). In any selected frame but the | |
2689 | innermost, this makes your program stop as soon as control | |
2690 | returns to that frame. This is similar to the effect of a | |
2691 | @code{finish} command in the frame inside the selected frame---except | |
2692 | that @code{finish} does not leave an active breakpoint. If you use | |
2693 | @code{break} without an argument in the innermost frame, @value{GDBN} stops | |
2694 | the next time it reaches the current location; this may be useful | |
2695 | inside loops. | |
2696 | ||
2697 | @value{GDBN} normally ignores breakpoints when it resumes execution, until at | |
2698 | least one instruction has been executed. If it did not do this, you | |
2699 | would be unable to proceed past a breakpoint without first disabling the | |
2700 | breakpoint. This rule applies whether or not the breakpoint already | |
2701 | existed when your program stopped. | |
2702 | ||
2703 | @item break @dots{} if @var{cond} | |
2704 | Set a breakpoint with condition @var{cond}; evaluate the expression | |
2705 | @var{cond} each time the breakpoint is reached, and stop only if the | |
2706 | value is nonzero---that is, if @var{cond} evaluates as true. | |
2707 | @samp{@dots{}} stands for one of the possible arguments described | |
2708 | above (or no argument) specifying where to break. @xref{Conditions, | |
2709 | ,Break conditions}, for more information on breakpoint conditions. | |
2710 | ||
2711 | @kindex tbreak | |
2712 | @item tbreak @var{args} | |
2713 | Set a breakpoint enabled only for one stop. @var{args} are the | |
2714 | same as for the @code{break} command, and the breakpoint is set in the same | |
2715 | way, but the breakpoint is automatically deleted after the first time your | |
2716 | program stops there. @xref{Disabling, ,Disabling breakpoints}. | |
2717 | ||
c906108c | 2718 | @kindex hbreak |
ba04e063 | 2719 | @cindex hardware breakpoints |
c906108c | 2720 | @item hbreak @var{args} |
d4f3574e SS |
2721 | Set a hardware-assisted breakpoint. @var{args} are the same as for the |
2722 | @code{break} command and the breakpoint is set in the same way, but the | |
c906108c SS |
2723 | breakpoint requires hardware support and some target hardware may not |
2724 | have this support. The main purpose of this is EPROM/ROM code | |
d4f3574e SS |
2725 | debugging, so you can set a breakpoint at an instruction without |
2726 | changing the instruction. This can be used with the new trap-generation | |
09d4efe1 | 2727 | provided by SPARClite DSU and most x86-based targets. These targets |
d4f3574e SS |
2728 | will generate traps when a program accesses some data or instruction |
2729 | address that is assigned to the debug registers. However the hardware | |
2730 | breakpoint registers can take a limited number of breakpoints. For | |
2731 | example, on the DSU, only two data breakpoints can be set at a time, and | |
2732 | @value{GDBN} will reject this command if more than two are used. Delete | |
2733 | or disable unused hardware breakpoints before setting new ones | |
2734 | (@pxref{Disabling, ,Disabling}). @xref{Conditions, ,Break conditions}. | |
9c16f35a EZ |
2735 | For remote targets, you can restrict the number of hardware |
2736 | breakpoints @value{GDBN} will use, see @ref{set remote | |
2737 | hardware-breakpoint-limit}. | |
501eef12 | 2738 | |
c906108c SS |
2739 | |
2740 | @kindex thbreak | |
2741 | @item thbreak @var{args} | |
2742 | Set a hardware-assisted breakpoint enabled only for one stop. @var{args} | |
2743 | are the same as for the @code{hbreak} command and the breakpoint is set in | |
5d161b24 | 2744 | the same way. However, like the @code{tbreak} command, |
c906108c SS |
2745 | the breakpoint is automatically deleted after the |
2746 | first time your program stops there. Also, like the @code{hbreak} | |
5d161b24 DB |
2747 | command, the breakpoint requires hardware support and some target hardware |
2748 | may not have this support. @xref{Disabling, ,Disabling breakpoints}. | |
d4f3574e | 2749 | See also @ref{Conditions, ,Break conditions}. |
c906108c SS |
2750 | |
2751 | @kindex rbreak | |
2752 | @cindex regular expression | |
c45da7e6 EZ |
2753 | @cindex breakpoints in functions matching a regexp |
2754 | @cindex set breakpoints in many functions | |
c906108c | 2755 | @item rbreak @var{regex} |
c906108c | 2756 | Set breakpoints on all functions matching the regular expression |
11cf8741 JM |
2757 | @var{regex}. This command sets an unconditional breakpoint on all |
2758 | matches, printing a list of all breakpoints it set. Once these | |
2759 | breakpoints are set, they are treated just like the breakpoints set with | |
2760 | the @code{break} command. You can delete them, disable them, or make | |
2761 | them conditional the same way as any other breakpoint. | |
2762 | ||
2763 | The syntax of the regular expression is the standard one used with tools | |
2764 | like @file{grep}. Note that this is different from the syntax used by | |
2765 | shells, so for instance @code{foo*} matches all functions that include | |
2766 | an @code{fo} followed by zero or more @code{o}s. There is an implicit | |
2767 | @code{.*} leading and trailing the regular expression you supply, so to | |
2768 | match only functions that begin with @code{foo}, use @code{^foo}. | |
c906108c | 2769 | |
f7dc1244 | 2770 | @cindex non-member C@t{++} functions, set breakpoint in |
b37052ae | 2771 | When debugging C@t{++} programs, @code{rbreak} is useful for setting |
c906108c SS |
2772 | breakpoints on overloaded functions that are not members of any special |
2773 | classes. | |
c906108c | 2774 | |
f7dc1244 EZ |
2775 | @cindex set breakpoints on all functions |
2776 | The @code{rbreak} command can be used to set breakpoints in | |
2777 | @strong{all} the functions in a program, like this: | |
2778 | ||
2779 | @smallexample | |
2780 | (@value{GDBP}) rbreak . | |
2781 | @end smallexample | |
2782 | ||
c906108c SS |
2783 | @kindex info breakpoints |
2784 | @cindex @code{$_} and @code{info breakpoints} | |
2785 | @item info breakpoints @r{[}@var{n}@r{]} | |
2786 | @itemx info break @r{[}@var{n}@r{]} | |
2787 | @itemx info watchpoints @r{[}@var{n}@r{]} | |
2788 | Print a table of all breakpoints, watchpoints, and catchpoints set and | |
2789 | not deleted, with the following columns for each breakpoint: | |
2790 | ||
2791 | @table @emph | |
2792 | @item Breakpoint Numbers | |
2793 | @item Type | |
2794 | Breakpoint, watchpoint, or catchpoint. | |
2795 | @item Disposition | |
2796 | Whether the breakpoint is marked to be disabled or deleted when hit. | |
2797 | @item Enabled or Disabled | |
2798 | Enabled breakpoints are marked with @samp{y}. @samp{n} marks breakpoints | |
2799 | that are not enabled. | |
2800 | @item Address | |
2650777c JJ |
2801 | Where the breakpoint is in your program, as a memory address. If the |
2802 | breakpoint is pending (see below for details) on a future load of a shared library, the address | |
2803 | will be listed as @samp{<PENDING>}. | |
c906108c SS |
2804 | @item What |
2805 | Where the breakpoint is in the source for your program, as a file and | |
2650777c JJ |
2806 | line number. For a pending breakpoint, the original string passed to |
2807 | the breakpoint command will be listed as it cannot be resolved until | |
2808 | the appropriate shared library is loaded in the future. | |
c906108c SS |
2809 | @end table |
2810 | ||
2811 | @noindent | |
2812 | If a breakpoint is conditional, @code{info break} shows the condition on | |
2813 | the line following the affected breakpoint; breakpoint commands, if any, | |
2650777c JJ |
2814 | are listed after that. A pending breakpoint is allowed to have a condition |
2815 | specified for it. The condition is not parsed for validity until a shared | |
2816 | library is loaded that allows the pending breakpoint to resolve to a | |
2817 | valid location. | |
c906108c SS |
2818 | |
2819 | @noindent | |
2820 | @code{info break} with a breakpoint | |
2821 | number @var{n} as argument lists only that breakpoint. The | |
2822 | convenience variable @code{$_} and the default examining-address for | |
2823 | the @code{x} command are set to the address of the last breakpoint | |
5d161b24 | 2824 | listed (@pxref{Memory, ,Examining memory}). |
c906108c SS |
2825 | |
2826 | @noindent | |
2827 | @code{info break} displays a count of the number of times the breakpoint | |
2828 | has been hit. This is especially useful in conjunction with the | |
2829 | @code{ignore} command. You can ignore a large number of breakpoint | |
2830 | hits, look at the breakpoint info to see how many times the breakpoint | |
2831 | was hit, and then run again, ignoring one less than that number. This | |
2832 | will get you quickly to the last hit of that breakpoint. | |
2833 | @end table | |
2834 | ||
2835 | @value{GDBN} allows you to set any number of breakpoints at the same place in | |
2836 | your program. There is nothing silly or meaningless about this. When | |
2837 | the breakpoints are conditional, this is even useful | |
2838 | (@pxref{Conditions, ,Break conditions}). | |
2839 | ||
2650777c | 2840 | @cindex pending breakpoints |
dd79a6cf JJ |
2841 | If a specified breakpoint location cannot be found, it may be due to the fact |
2842 | that the location is in a shared library that is yet to be loaded. In such | |
2843 | a case, you may want @value{GDBN} to create a special breakpoint (known as | |
2844 | a @dfn{pending breakpoint}) that | |
2845 | attempts to resolve itself in the future when an appropriate shared library | |
2846 | gets loaded. | |
2847 | ||
2848 | Pending breakpoints are useful to set at the start of your | |
2650777c JJ |
2849 | @value{GDBN} session for locations that you know will be dynamically loaded |
2850 | later by the program being debugged. When shared libraries are loaded, | |
dd79a6cf JJ |
2851 | a check is made to see if the load resolves any pending breakpoint locations. |
2852 | If a pending breakpoint location gets resolved, | |
2853 | a regular breakpoint is created and the original pending breakpoint is removed. | |
2854 | ||
2855 | @value{GDBN} provides some additional commands for controlling pending | |
2856 | breakpoint support: | |
2857 | ||
2858 | @kindex set breakpoint pending | |
2859 | @kindex show breakpoint pending | |
2860 | @table @code | |
2861 | @item set breakpoint pending auto | |
2862 | This is the default behavior. When @value{GDBN} cannot find the breakpoint | |
2863 | location, it queries you whether a pending breakpoint should be created. | |
2864 | ||
2865 | @item set breakpoint pending on | |
2866 | This indicates that an unrecognized breakpoint location should automatically | |
2867 | result in a pending breakpoint being created. | |
2868 | ||
2869 | @item set breakpoint pending off | |
2870 | This indicates that pending breakpoints are not to be created. Any | |
2871 | unrecognized breakpoint location results in an error. This setting does | |
2872 | not affect any pending breakpoints previously created. | |
2873 | ||
2874 | @item show breakpoint pending | |
2875 | Show the current behavior setting for creating pending breakpoints. | |
2876 | @end table | |
2650777c | 2877 | |
649e03f6 RM |
2878 | @cindex operations allowed on pending breakpoints |
2879 | Normal breakpoint operations apply to pending breakpoints as well. You may | |
2880 | specify a condition for a pending breakpoint and/or commands to run when the | |
2650777c JJ |
2881 | breakpoint is reached. You can also enable or disable |
2882 | the pending breakpoint. When you specify a condition for a pending breakpoint, | |
2883 | the parsing of the condition will be deferred until the point where the | |
2884 | pending breakpoint location is resolved. Disabling a pending breakpoint | |
2885 | tells @value{GDBN} to not attempt to resolve the breakpoint on any subsequent | |
2886 | shared library load. When a pending breakpoint is re-enabled, | |
649e03f6 | 2887 | @value{GDBN} checks to see if the location is already resolved. |
2650777c JJ |
2888 | This is done because any number of shared library loads could have |
2889 | occurred since the time the breakpoint was disabled and one or more | |
2890 | of these loads could resolve the location. | |
2891 | ||
c906108c SS |
2892 | @cindex negative breakpoint numbers |
2893 | @cindex internal @value{GDBN} breakpoints | |
eb12ee30 AC |
2894 | @value{GDBN} itself sometimes sets breakpoints in your program for |
2895 | special purposes, such as proper handling of @code{longjmp} (in C | |
2896 | programs). These internal breakpoints are assigned negative numbers, | |
2897 | starting with @code{-1}; @samp{info breakpoints} does not display them. | |
c906108c | 2898 | You can see these breakpoints with the @value{GDBN} maintenance command |
eb12ee30 | 2899 | @samp{maint info breakpoints} (@pxref{maint info breakpoints}). |
c906108c SS |
2900 | |
2901 | ||
6d2ebf8b | 2902 | @node Set Watchpoints |
c906108c SS |
2903 | @subsection Setting watchpoints |
2904 | ||
2905 | @cindex setting watchpoints | |
c906108c SS |
2906 | You can use a watchpoint to stop execution whenever the value of an |
2907 | expression changes, without having to predict a particular place where | |
2908 | this may happen. | |
2909 | ||
82f2d802 EZ |
2910 | @cindex software watchpoints |
2911 | @cindex hardware watchpoints | |
c906108c | 2912 | Depending on your system, watchpoints may be implemented in software or |
2df3850c | 2913 | hardware. @value{GDBN} does software watchpointing by single-stepping your |
c906108c SS |
2914 | program and testing the variable's value each time, which is hundreds of |
2915 | times slower than normal execution. (But this may still be worth it, to | |
2916 | catch errors where you have no clue what part of your program is the | |
2917 | culprit.) | |
2918 | ||
82f2d802 EZ |
2919 | On some systems, such as HP-UX, @sc{gnu}/Linux and most other |
2920 | x86-based targets, @value{GDBN} includes support for hardware | |
2921 | watchpoints, which do not slow down the running of your program. | |
c906108c SS |
2922 | |
2923 | @table @code | |
2924 | @kindex watch | |
2925 | @item watch @var{expr} | |
2926 | Set a watchpoint for an expression. @value{GDBN} will break when @var{expr} | |
2927 | is written into by the program and its value changes. | |
2928 | ||
2929 | @kindex rwatch | |
2930 | @item rwatch @var{expr} | |
09d4efe1 EZ |
2931 | Set a watchpoint that will break when the value of @var{expr} is read |
2932 | by the program. | |
c906108c SS |
2933 | |
2934 | @kindex awatch | |
2935 | @item awatch @var{expr} | |
09d4efe1 EZ |
2936 | Set a watchpoint that will break when @var{expr} is either read from |
2937 | or written into by the program. | |
c906108c SS |
2938 | |
2939 | @kindex info watchpoints | |
2940 | @item info watchpoints | |
2941 | This command prints a list of watchpoints, breakpoints, and catchpoints; | |
09d4efe1 | 2942 | it is the same as @code{info break} (@pxref{Set Breaks}). |
c906108c SS |
2943 | @end table |
2944 | ||
2945 | @value{GDBN} sets a @dfn{hardware watchpoint} if possible. Hardware | |
2946 | watchpoints execute very quickly, and the debugger reports a change in | |
2947 | value at the exact instruction where the change occurs. If @value{GDBN} | |
2948 | cannot set a hardware watchpoint, it sets a software watchpoint, which | |
2949 | executes more slowly and reports the change in value at the next | |
82f2d802 EZ |
2950 | @emph{statement}, not the instruction, after the change occurs. |
2951 | ||
82f2d802 EZ |
2952 | @cindex use only software watchpoints |
2953 | You can force @value{GDBN} to use only software watchpoints with the | |
2954 | @kbd{set can-use-hw-watchpoints 0} command. With this variable set to | |
2955 | zero, @value{GDBN} will never try to use hardware watchpoints, even if | |
2956 | the underlying system supports them. (Note that hardware-assisted | |
2957 | watchpoints that were set @emph{before} setting | |
2958 | @code{can-use-hw-watchpoints} to zero will still use the hardware | |
2959 | mechanism of watching expressiion values.) | |
c906108c | 2960 | |
9c16f35a EZ |
2961 | @table @code |
2962 | @item set can-use-hw-watchpoints | |
2963 | @kindex set can-use-hw-watchpoints | |
2964 | Set whether or not to use hardware watchpoints. | |
2965 | ||
2966 | @item show can-use-hw-watchpoints | |
2967 | @kindex show can-use-hw-watchpoints | |
2968 | Show the current mode of using hardware watchpoints. | |
2969 | @end table | |
2970 | ||
2971 | For remote targets, you can restrict the number of hardware | |
2972 | watchpoints @value{GDBN} will use, see @ref{set remote | |
2973 | hardware-breakpoint-limit}. | |
2974 | ||
c906108c SS |
2975 | When you issue the @code{watch} command, @value{GDBN} reports |
2976 | ||
474c8240 | 2977 | @smallexample |
c906108c | 2978 | Hardware watchpoint @var{num}: @var{expr} |
474c8240 | 2979 | @end smallexample |
c906108c SS |
2980 | |
2981 | @noindent | |
2982 | if it was able to set a hardware watchpoint. | |
2983 | ||
7be570e7 JM |
2984 | Currently, the @code{awatch} and @code{rwatch} commands can only set |
2985 | hardware watchpoints, because accesses to data that don't change the | |
2986 | value of the watched expression cannot be detected without examining | |
2987 | every instruction as it is being executed, and @value{GDBN} does not do | |
2988 | that currently. If @value{GDBN} finds that it is unable to set a | |
2989 | hardware breakpoint with the @code{awatch} or @code{rwatch} command, it | |
2990 | will print a message like this: | |
2991 | ||
2992 | @smallexample | |
2993 | Expression cannot be implemented with read/access watchpoint. | |
2994 | @end smallexample | |
2995 | ||
2996 | Sometimes, @value{GDBN} cannot set a hardware watchpoint because the | |
2997 | data type of the watched expression is wider than what a hardware | |
2998 | watchpoint on the target machine can handle. For example, some systems | |
2999 | can only watch regions that are up to 4 bytes wide; on such systems you | |
3000 | cannot set hardware watchpoints for an expression that yields a | |
3001 | double-precision floating-point number (which is typically 8 bytes | |
3002 | wide). As a work-around, it might be possible to break the large region | |
3003 | into a series of smaller ones and watch them with separate watchpoints. | |
3004 | ||
3005 | If you set too many hardware watchpoints, @value{GDBN} might be unable | |
3006 | to insert all of them when you resume the execution of your program. | |
3007 | Since the precise number of active watchpoints is unknown until such | |
3008 | time as the program is about to be resumed, @value{GDBN} might not be | |
3009 | able to warn you about this when you set the watchpoints, and the | |
3010 | warning will be printed only when the program is resumed: | |
3011 | ||
3012 | @smallexample | |
3013 | Hardware watchpoint @var{num}: Could not insert watchpoint | |
3014 | @end smallexample | |
3015 | ||
3016 | @noindent | |
3017 | If this happens, delete or disable some of the watchpoints. | |
3018 | ||
3019 | The SPARClite DSU will generate traps when a program accesses some data | |
3020 | or instruction address that is assigned to the debug registers. For the | |
3021 | data addresses, DSU facilitates the @code{watch} command. However the | |
3022 | hardware breakpoint registers can only take two data watchpoints, and | |
3023 | both watchpoints must be the same kind. For example, you can set two | |
3024 | watchpoints with @code{watch} commands, two with @code{rwatch} commands, | |
3025 | @strong{or} two with @code{awatch} commands, but you cannot set one | |
3026 | watchpoint with one command and the other with a different command. | |
c906108c SS |
3027 | @value{GDBN} will reject the command if you try to mix watchpoints. |
3028 | Delete or disable unused watchpoint commands before setting new ones. | |
3029 | ||
3030 | If you call a function interactively using @code{print} or @code{call}, | |
2df3850c | 3031 | any watchpoints you have set will be inactive until @value{GDBN} reaches another |
c906108c SS |
3032 | kind of breakpoint or the call completes. |
3033 | ||
7be570e7 JM |
3034 | @value{GDBN} automatically deletes watchpoints that watch local |
3035 | (automatic) variables, or expressions that involve such variables, when | |
3036 | they go out of scope, that is, when the execution leaves the block in | |
3037 | which these variables were defined. In particular, when the program | |
3038 | being debugged terminates, @emph{all} local variables go out of scope, | |
3039 | and so only watchpoints that watch global variables remain set. If you | |
3040 | rerun the program, you will need to set all such watchpoints again. One | |
3041 | way of doing that would be to set a code breakpoint at the entry to the | |
3042 | @code{main} function and when it breaks, set all the watchpoints. | |
3043 | ||
c906108c SS |
3044 | @quotation |
3045 | @cindex watchpoints and threads | |
3046 | @cindex threads and watchpoints | |
c906108c SS |
3047 | @emph{Warning:} In multi-thread programs, watchpoints have only limited |
3048 | usefulness. With the current watchpoint implementation, @value{GDBN} | |
3049 | can only watch the value of an expression @emph{in a single thread}. If | |
3050 | you are confident that the expression can only change due to the current | |
3051 | thread's activity (and if you are also confident that no other thread | |
3052 | can become current), then you can use watchpoints as usual. However, | |
3053 | @value{GDBN} may not notice when a non-current thread's activity changes | |
3054 | the expression. | |
53a5351d | 3055 | |
d4f3574e | 3056 | @c FIXME: this is almost identical to the previous paragraph. |
53a5351d JM |
3057 | @emph{HP-UX Warning:} In multi-thread programs, software watchpoints |
3058 | have only limited usefulness. If @value{GDBN} creates a software | |
3059 | watchpoint, it can only watch the value of an expression @emph{in a | |
3060 | single thread}. If you are confident that the expression can only | |
3061 | change due to the current thread's activity (and if you are also | |
3062 | confident that no other thread can become current), then you can use | |
3063 | software watchpoints as usual. However, @value{GDBN} may not notice | |
3064 | when a non-current thread's activity changes the expression. (Hardware | |
3065 | watchpoints, in contrast, watch an expression in all threads.) | |
c906108c | 3066 | @end quotation |
c906108c | 3067 | |
501eef12 AC |
3068 | @xref{set remote hardware-watchpoint-limit}. |
3069 | ||
6d2ebf8b | 3070 | @node Set Catchpoints |
c906108c | 3071 | @subsection Setting catchpoints |
d4f3574e | 3072 | @cindex catchpoints, setting |
c906108c SS |
3073 | @cindex exception handlers |
3074 | @cindex event handling | |
3075 | ||
3076 | You can use @dfn{catchpoints} to cause the debugger to stop for certain | |
b37052ae | 3077 | kinds of program events, such as C@t{++} exceptions or the loading of a |
c906108c SS |
3078 | shared library. Use the @code{catch} command to set a catchpoint. |
3079 | ||
3080 | @table @code | |
3081 | @kindex catch | |
3082 | @item catch @var{event} | |
3083 | Stop when @var{event} occurs. @var{event} can be any of the following: | |
3084 | @table @code | |
3085 | @item throw | |
4644b6e3 | 3086 | @cindex stop on C@t{++} exceptions |
b37052ae | 3087 | The throwing of a C@t{++} exception. |
c906108c SS |
3088 | |
3089 | @item catch | |
b37052ae | 3090 | The catching of a C@t{++} exception. |
c906108c SS |
3091 | |
3092 | @item exec | |
4644b6e3 | 3093 | @cindex break on fork/exec |
c906108c SS |
3094 | A call to @code{exec}. This is currently only available for HP-UX. |
3095 | ||
3096 | @item fork | |
c906108c SS |
3097 | A call to @code{fork}. This is currently only available for HP-UX. |
3098 | ||
3099 | @item vfork | |
c906108c SS |
3100 | A call to @code{vfork}. This is currently only available for HP-UX. |
3101 | ||
3102 | @item load | |
3103 | @itemx load @var{libname} | |
4644b6e3 | 3104 | @cindex break on load/unload of shared library |
c906108c SS |
3105 | The dynamic loading of any shared library, or the loading of the library |
3106 | @var{libname}. This is currently only available for HP-UX. | |
3107 | ||
3108 | @item unload | |
3109 | @itemx unload @var{libname} | |
c906108c SS |
3110 | The unloading of any dynamically loaded shared library, or the unloading |
3111 | of the library @var{libname}. This is currently only available for HP-UX. | |
3112 | @end table | |
3113 | ||
3114 | @item tcatch @var{event} | |
3115 | Set a catchpoint that is enabled only for one stop. The catchpoint is | |
3116 | automatically deleted after the first time the event is caught. | |
3117 | ||
3118 | @end table | |
3119 | ||
3120 | Use the @code{info break} command to list the current catchpoints. | |
3121 | ||
b37052ae | 3122 | There are currently some limitations to C@t{++} exception handling |
c906108c SS |
3123 | (@code{catch throw} and @code{catch catch}) in @value{GDBN}: |
3124 | ||
3125 | @itemize @bullet | |
3126 | @item | |
3127 | If you call a function interactively, @value{GDBN} normally returns | |
3128 | control to you when the function has finished executing. If the call | |
3129 | raises an exception, however, the call may bypass the mechanism that | |
3130 | returns control to you and cause your program either to abort or to | |
3131 | simply continue running until it hits a breakpoint, catches a signal | |
3132 | that @value{GDBN} is listening for, or exits. This is the case even if | |
3133 | you set a catchpoint for the exception; catchpoints on exceptions are | |
3134 | disabled within interactive calls. | |
3135 | ||
3136 | @item | |
3137 | You cannot raise an exception interactively. | |
3138 | ||
3139 | @item | |
3140 | You cannot install an exception handler interactively. | |
3141 | @end itemize | |
3142 | ||
3143 | @cindex raise exceptions | |
3144 | Sometimes @code{catch} is not the best way to debug exception handling: | |
3145 | if you need to know exactly where an exception is raised, it is better to | |
3146 | stop @emph{before} the exception handler is called, since that way you | |
3147 | can see the stack before any unwinding takes place. If you set a | |
3148 | breakpoint in an exception handler instead, it may not be easy to find | |
3149 | out where the exception was raised. | |
3150 | ||
3151 | To stop just before an exception handler is called, you need some | |
b37052ae | 3152 | knowledge of the implementation. In the case of @sc{gnu} C@t{++}, exceptions are |
c906108c SS |
3153 | raised by calling a library function named @code{__raise_exception} |
3154 | which has the following ANSI C interface: | |
3155 | ||
474c8240 | 3156 | @smallexample |
c906108c | 3157 | /* @var{addr} is where the exception identifier is stored. |
d4f3574e SS |
3158 | @var{id} is the exception identifier. */ |
3159 | void __raise_exception (void **addr, void *id); | |
474c8240 | 3160 | @end smallexample |
c906108c SS |
3161 | |
3162 | @noindent | |
3163 | To make the debugger catch all exceptions before any stack | |
3164 | unwinding takes place, set a breakpoint on @code{__raise_exception} | |
3165 | (@pxref{Breakpoints, ,Breakpoints; watchpoints; and exceptions}). | |
3166 | ||
3167 | With a conditional breakpoint (@pxref{Conditions, ,Break conditions}) | |
3168 | that depends on the value of @var{id}, you can stop your program when | |
3169 | a specific exception is raised. You can use multiple conditional | |
3170 | breakpoints to stop your program when any of a number of exceptions are | |
3171 | raised. | |
3172 | ||
3173 | ||
6d2ebf8b | 3174 | @node Delete Breaks |
c906108c SS |
3175 | @subsection Deleting breakpoints |
3176 | ||
3177 | @cindex clearing breakpoints, watchpoints, catchpoints | |
3178 | @cindex deleting breakpoints, watchpoints, catchpoints | |
3179 | It is often necessary to eliminate a breakpoint, watchpoint, or | |
3180 | catchpoint once it has done its job and you no longer want your program | |
3181 | to stop there. This is called @dfn{deleting} the breakpoint. A | |
3182 | breakpoint that has been deleted no longer exists; it is forgotten. | |
3183 | ||
3184 | With the @code{clear} command you can delete breakpoints according to | |
3185 | where they are in your program. With the @code{delete} command you can | |
3186 | delete individual breakpoints, watchpoints, or catchpoints by specifying | |
3187 | their breakpoint numbers. | |
3188 | ||
3189 | It is not necessary to delete a breakpoint to proceed past it. @value{GDBN} | |
3190 | automatically ignores breakpoints on the first instruction to be executed | |
3191 | when you continue execution without changing the execution address. | |
3192 | ||
3193 | @table @code | |
3194 | @kindex clear | |
3195 | @item clear | |
3196 | Delete any breakpoints at the next instruction to be executed in the | |
3197 | selected stack frame (@pxref{Selection, ,Selecting a frame}). When | |
3198 | the innermost frame is selected, this is a good way to delete a | |
3199 | breakpoint where your program just stopped. | |
3200 | ||
3201 | @item clear @var{function} | |
3202 | @itemx clear @var{filename}:@var{function} | |
09d4efe1 | 3203 | Delete any breakpoints set at entry to the named @var{function}. |
c906108c SS |
3204 | |
3205 | @item clear @var{linenum} | |
3206 | @itemx clear @var{filename}:@var{linenum} | |
09d4efe1 EZ |
3207 | Delete any breakpoints set at or within the code of the specified |
3208 | @var{linenum} of the specified @var{filename}. | |
c906108c SS |
3209 | |
3210 | @cindex delete breakpoints | |
3211 | @kindex delete | |
41afff9a | 3212 | @kindex d @r{(@code{delete})} |
c5394b80 JM |
3213 | @item delete @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
3214 | Delete the breakpoints, watchpoints, or catchpoints of the breakpoint | |
3215 | ranges specified as arguments. If no argument is specified, delete all | |
c906108c SS |
3216 | breakpoints (@value{GDBN} asks confirmation, unless you have @code{set |
3217 | confirm off}). You can abbreviate this command as @code{d}. | |
3218 | @end table | |
3219 | ||
6d2ebf8b | 3220 | @node Disabling |
c906108c SS |
3221 | @subsection Disabling breakpoints |
3222 | ||
4644b6e3 | 3223 | @cindex enable/disable a breakpoint |
c906108c SS |
3224 | Rather than deleting a breakpoint, watchpoint, or catchpoint, you might |
3225 | prefer to @dfn{disable} it. This makes the breakpoint inoperative as if | |
3226 | it had been deleted, but remembers the information on the breakpoint so | |
3227 | that you can @dfn{enable} it again later. | |
3228 | ||
3229 | You disable and enable breakpoints, watchpoints, and catchpoints with | |
3230 | the @code{enable} and @code{disable} commands, optionally specifying one | |
3231 | or more breakpoint numbers as arguments. Use @code{info break} or | |
3232 | @code{info watch} to print a list of breakpoints, watchpoints, and | |
3233 | catchpoints if you do not know which numbers to use. | |
3234 | ||
3235 | A breakpoint, watchpoint, or catchpoint can have any of four different | |
3236 | states of enablement: | |
3237 | ||
3238 | @itemize @bullet | |
3239 | @item | |
3240 | Enabled. The breakpoint stops your program. A breakpoint set | |
3241 | with the @code{break} command starts out in this state. | |
3242 | @item | |
3243 | Disabled. The breakpoint has no effect on your program. | |
3244 | @item | |
3245 | Enabled once. The breakpoint stops your program, but then becomes | |
d4f3574e | 3246 | disabled. |
c906108c SS |
3247 | @item |
3248 | Enabled for deletion. The breakpoint stops your program, but | |
d4f3574e SS |
3249 | immediately after it does so it is deleted permanently. A breakpoint |
3250 | set with the @code{tbreak} command starts out in this state. | |
c906108c SS |
3251 | @end itemize |
3252 | ||
3253 | You can use the following commands to enable or disable breakpoints, | |
3254 | watchpoints, and catchpoints: | |
3255 | ||
3256 | @table @code | |
c906108c | 3257 | @kindex disable |
41afff9a | 3258 | @kindex dis @r{(@code{disable})} |
c5394b80 | 3259 | @item disable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
3260 | Disable the specified breakpoints---or all breakpoints, if none are |
3261 | listed. A disabled breakpoint has no effect but is not forgotten. All | |
3262 | options such as ignore-counts, conditions and commands are remembered in | |
3263 | case the breakpoint is enabled again later. You may abbreviate | |
3264 | @code{disable} as @code{dis}. | |
3265 | ||
c906108c | 3266 | @kindex enable |
c5394b80 | 3267 | @item enable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
3268 | Enable the specified breakpoints (or all defined breakpoints). They |
3269 | become effective once again in stopping your program. | |
3270 | ||
c5394b80 | 3271 | @item enable @r{[}breakpoints@r{]} once @var{range}@dots{} |
c906108c SS |
3272 | Enable the specified breakpoints temporarily. @value{GDBN} disables any |
3273 | of these breakpoints immediately after stopping your program. | |
3274 | ||
c5394b80 | 3275 | @item enable @r{[}breakpoints@r{]} delete @var{range}@dots{} |
c906108c SS |
3276 | Enable the specified breakpoints to work once, then die. @value{GDBN} |
3277 | deletes any of these breakpoints as soon as your program stops there. | |
09d4efe1 | 3278 | Breakpoints set by the @code{tbreak} command start out in this state. |
c906108c SS |
3279 | @end table |
3280 | ||
d4f3574e SS |
3281 | @c FIXME: I think the following ``Except for [...] @code{tbreak}'' is |
3282 | @c confusing: tbreak is also initially enabled. | |
c906108c SS |
3283 | Except for a breakpoint set with @code{tbreak} (@pxref{Set Breaks, |
3284 | ,Setting breakpoints}), breakpoints that you set are initially enabled; | |
3285 | subsequently, they become disabled or enabled only when you use one of | |
3286 | the commands above. (The command @code{until} can set and delete a | |
3287 | breakpoint of its own, but it does not change the state of your other | |
3288 | breakpoints; see @ref{Continuing and Stepping, ,Continuing and | |
3289 | stepping}.) | |
3290 | ||
6d2ebf8b | 3291 | @node Conditions |
c906108c SS |
3292 | @subsection Break conditions |
3293 | @cindex conditional breakpoints | |
3294 | @cindex breakpoint conditions | |
3295 | ||
3296 | @c FIXME what is scope of break condition expr? Context where wanted? | |
5d161b24 | 3297 | @c in particular for a watchpoint? |
c906108c SS |
3298 | The simplest sort of breakpoint breaks every time your program reaches a |
3299 | specified place. You can also specify a @dfn{condition} for a | |
3300 | breakpoint. A condition is just a Boolean expression in your | |
3301 | programming language (@pxref{Expressions, ,Expressions}). A breakpoint with | |
3302 | a condition evaluates the expression each time your program reaches it, | |
3303 | and your program stops only if the condition is @emph{true}. | |
3304 | ||
3305 | This is the converse of using assertions for program validation; in that | |
3306 | situation, you want to stop when the assertion is violated---that is, | |
3307 | when the condition is false. In C, if you want to test an assertion expressed | |
3308 | by the condition @var{assert}, you should set the condition | |
3309 | @samp{! @var{assert}} on the appropriate breakpoint. | |
3310 | ||
3311 | Conditions are also accepted for watchpoints; you may not need them, | |
3312 | since a watchpoint is inspecting the value of an expression anyhow---but | |
3313 | it might be simpler, say, to just set a watchpoint on a variable name, | |
3314 | and specify a condition that tests whether the new value is an interesting | |
3315 | one. | |
3316 | ||
3317 | Break conditions can have side effects, and may even call functions in | |
3318 | your program. This can be useful, for example, to activate functions | |
3319 | that log program progress, or to use your own print functions to | |
3320 | format special data structures. The effects are completely predictable | |
3321 | unless there is another enabled breakpoint at the same address. (In | |
3322 | that case, @value{GDBN} might see the other breakpoint first and stop your | |
3323 | program without checking the condition of this one.) Note that | |
d4f3574e SS |
3324 | breakpoint commands are usually more convenient and flexible than break |
3325 | conditions for the | |
c906108c SS |
3326 | purpose of performing side effects when a breakpoint is reached |
3327 | (@pxref{Break Commands, ,Breakpoint command lists}). | |
3328 | ||
3329 | Break conditions can be specified when a breakpoint is set, by using | |
3330 | @samp{if} in the arguments to the @code{break} command. @xref{Set | |
3331 | Breaks, ,Setting breakpoints}. They can also be changed at any time | |
3332 | with the @code{condition} command. | |
53a5351d | 3333 | |
c906108c SS |
3334 | You can also use the @code{if} keyword with the @code{watch} command. |
3335 | The @code{catch} command does not recognize the @code{if} keyword; | |
3336 | @code{condition} is the only way to impose a further condition on a | |
3337 | catchpoint. | |
c906108c SS |
3338 | |
3339 | @table @code | |
3340 | @kindex condition | |
3341 | @item condition @var{bnum} @var{expression} | |
3342 | Specify @var{expression} as the break condition for breakpoint, | |
3343 | watchpoint, or catchpoint number @var{bnum}. After you set a condition, | |
3344 | breakpoint @var{bnum} stops your program only if the value of | |
3345 | @var{expression} is true (nonzero, in C). When you use | |
3346 | @code{condition}, @value{GDBN} checks @var{expression} immediately for | |
3347 | syntactic correctness, and to determine whether symbols in it have | |
d4f3574e SS |
3348 | referents in the context of your breakpoint. If @var{expression} uses |
3349 | symbols not referenced in the context of the breakpoint, @value{GDBN} | |
3350 | prints an error message: | |
3351 | ||
474c8240 | 3352 | @smallexample |
d4f3574e | 3353 | No symbol "foo" in current context. |
474c8240 | 3354 | @end smallexample |
d4f3574e SS |
3355 | |
3356 | @noindent | |
c906108c SS |
3357 | @value{GDBN} does |
3358 | not actually evaluate @var{expression} at the time the @code{condition} | |
d4f3574e SS |
3359 | command (or a command that sets a breakpoint with a condition, like |
3360 | @code{break if @dots{}}) is given, however. @xref{Expressions, ,Expressions}. | |
c906108c SS |
3361 | |
3362 | @item condition @var{bnum} | |
3363 | Remove the condition from breakpoint number @var{bnum}. It becomes | |
3364 | an ordinary unconditional breakpoint. | |
3365 | @end table | |
3366 | ||
3367 | @cindex ignore count (of breakpoint) | |
3368 | A special case of a breakpoint condition is to stop only when the | |
3369 | breakpoint has been reached a certain number of times. This is so | |
3370 | useful that there is a special way to do it, using the @dfn{ignore | |
3371 | count} of the breakpoint. Every breakpoint has an ignore count, which | |
3372 | is an integer. Most of the time, the ignore count is zero, and | |
3373 | therefore has no effect. But if your program reaches a breakpoint whose | |
3374 | ignore count is positive, then instead of stopping, it just decrements | |
3375 | the ignore count by one and continues. As a result, if the ignore count | |
3376 | value is @var{n}, the breakpoint does not stop the next @var{n} times | |
3377 | your program reaches it. | |
3378 | ||
3379 | @table @code | |
3380 | @kindex ignore | |
3381 | @item ignore @var{bnum} @var{count} | |
3382 | Set the ignore count of breakpoint number @var{bnum} to @var{count}. | |
3383 | The next @var{count} times the breakpoint is reached, your program's | |
3384 | execution does not stop; other than to decrement the ignore count, @value{GDBN} | |
3385 | takes no action. | |
3386 | ||
3387 | To make the breakpoint stop the next time it is reached, specify | |
3388 | a count of zero. | |
3389 | ||
3390 | When you use @code{continue} to resume execution of your program from a | |
3391 | breakpoint, you can specify an ignore count directly as an argument to | |
3392 | @code{continue}, rather than using @code{ignore}. @xref{Continuing and | |
3393 | Stepping,,Continuing and stepping}. | |
3394 | ||
3395 | If a breakpoint has a positive ignore count and a condition, the | |
3396 | condition is not checked. Once the ignore count reaches zero, | |
3397 | @value{GDBN} resumes checking the condition. | |
3398 | ||
3399 | You could achieve the effect of the ignore count with a condition such | |
3400 | as @w{@samp{$foo-- <= 0}} using a debugger convenience variable that | |
3401 | is decremented each time. @xref{Convenience Vars, ,Convenience | |
3402 | variables}. | |
3403 | @end table | |
3404 | ||
3405 | Ignore counts apply to breakpoints, watchpoints, and catchpoints. | |
3406 | ||
3407 | ||
6d2ebf8b | 3408 | @node Break Commands |
c906108c SS |
3409 | @subsection Breakpoint command lists |
3410 | ||
3411 | @cindex breakpoint commands | |
3412 | You can give any breakpoint (or watchpoint or catchpoint) a series of | |
3413 | commands to execute when your program stops due to that breakpoint. For | |
3414 | example, you might want to print the values of certain expressions, or | |
3415 | enable other breakpoints. | |
3416 | ||
3417 | @table @code | |
3418 | @kindex commands | |
3419 | @kindex end | |
3420 | @item commands @r{[}@var{bnum}@r{]} | |
3421 | @itemx @dots{} @var{command-list} @dots{} | |
3422 | @itemx end | |
3423 | Specify a list of commands for breakpoint number @var{bnum}. The commands | |
3424 | themselves appear on the following lines. Type a line containing just | |
3425 | @code{end} to terminate the commands. | |
3426 | ||
3427 | To remove all commands from a breakpoint, type @code{commands} and | |
3428 | follow it immediately with @code{end}; that is, give no commands. | |
3429 | ||
3430 | With no @var{bnum} argument, @code{commands} refers to the last | |
3431 | breakpoint, watchpoint, or catchpoint set (not to the breakpoint most | |
3432 | recently encountered). | |
3433 | @end table | |
3434 | ||
3435 | Pressing @key{RET} as a means of repeating the last @value{GDBN} command is | |
3436 | disabled within a @var{command-list}. | |
3437 | ||
3438 | You can use breakpoint commands to start your program up again. Simply | |
3439 | use the @code{continue} command, or @code{step}, or any other command | |
3440 | that resumes execution. | |
3441 | ||
3442 | Any other commands in the command list, after a command that resumes | |
3443 | execution, are ignored. This is because any time you resume execution | |
3444 | (even with a simple @code{next} or @code{step}), you may encounter | |
3445 | another breakpoint---which could have its own command list, leading to | |
3446 | ambiguities about which list to execute. | |
3447 | ||
3448 | @kindex silent | |
3449 | If the first command you specify in a command list is @code{silent}, the | |
3450 | usual message about stopping at a breakpoint is not printed. This may | |
3451 | be desirable for breakpoints that are to print a specific message and | |
3452 | then continue. If none of the remaining commands print anything, you | |
3453 | see no sign that the breakpoint was reached. @code{silent} is | |
3454 | meaningful only at the beginning of a breakpoint command list. | |
3455 | ||
3456 | The commands @code{echo}, @code{output}, and @code{printf} allow you to | |
3457 | print precisely controlled output, and are often useful in silent | |
3458 | breakpoints. @xref{Output, ,Commands for controlled output}. | |
3459 | ||
3460 | For example, here is how you could use breakpoint commands to print the | |
3461 | value of @code{x} at entry to @code{foo} whenever @code{x} is positive. | |
3462 | ||
474c8240 | 3463 | @smallexample |
c906108c SS |
3464 | break foo if x>0 |
3465 | commands | |
3466 | silent | |
3467 | printf "x is %d\n",x | |
3468 | cont | |
3469 | end | |
474c8240 | 3470 | @end smallexample |
c906108c SS |
3471 | |
3472 | One application for breakpoint commands is to compensate for one bug so | |
3473 | you can test for another. Put a breakpoint just after the erroneous line | |
3474 | of code, give it a condition to detect the case in which something | |
3475 | erroneous has been done, and give it commands to assign correct values | |
3476 | to any variables that need them. End with the @code{continue} command | |
3477 | so that your program does not stop, and start with the @code{silent} | |
3478 | command so that no output is produced. Here is an example: | |
3479 | ||
474c8240 | 3480 | @smallexample |
c906108c SS |
3481 | break 403 |
3482 | commands | |
3483 | silent | |
3484 | set x = y + 4 | |
3485 | cont | |
3486 | end | |
474c8240 | 3487 | @end smallexample |
c906108c | 3488 | |
6d2ebf8b | 3489 | @node Breakpoint Menus |
c906108c SS |
3490 | @subsection Breakpoint menus |
3491 | @cindex overloading | |
3492 | @cindex symbol overloading | |
3493 | ||
b383017d | 3494 | Some programming languages (notably C@t{++} and Objective-C) permit a |
b37303ee | 3495 | single function name |
c906108c SS |
3496 | to be defined several times, for application in different contexts. |
3497 | This is called @dfn{overloading}. When a function name is overloaded, | |
3498 | @samp{break @var{function}} is not enough to tell @value{GDBN} where you want | |
3499 | a breakpoint. If you realize this is a problem, you can use | |
3500 | something like @samp{break @var{function}(@var{types})} to specify which | |
3501 | particular version of the function you want. Otherwise, @value{GDBN} offers | |
3502 | you a menu of numbered choices for different possible breakpoints, and | |
3503 | waits for your selection with the prompt @samp{>}. The first two | |
3504 | options are always @samp{[0] cancel} and @samp{[1] all}. Typing @kbd{1} | |
3505 | sets a breakpoint at each definition of @var{function}, and typing | |
3506 | @kbd{0} aborts the @code{break} command without setting any new | |
3507 | breakpoints. | |
3508 | ||
3509 | For example, the following session excerpt shows an attempt to set a | |
3510 | breakpoint at the overloaded symbol @code{String::after}. | |
3511 | We choose three particular definitions of that function name: | |
3512 | ||
3513 | @c FIXME! This is likely to change to show arg type lists, at least | |
3514 | @smallexample | |
3515 | @group | |
3516 | (@value{GDBP}) b String::after | |
3517 | [0] cancel | |
3518 | [1] all | |
3519 | [2] file:String.cc; line number:867 | |
3520 | [3] file:String.cc; line number:860 | |
3521 | [4] file:String.cc; line number:875 | |
3522 | [5] file:String.cc; line number:853 | |
3523 | [6] file:String.cc; line number:846 | |
3524 | [7] file:String.cc; line number:735 | |
3525 | > 2 4 6 | |
3526 | Breakpoint 1 at 0xb26c: file String.cc, line 867. | |
3527 | Breakpoint 2 at 0xb344: file String.cc, line 875. | |
3528 | Breakpoint 3 at 0xafcc: file String.cc, line 846. | |
3529 | Multiple breakpoints were set. | |
3530 | Use the "delete" command to delete unwanted | |
3531 | breakpoints. | |
3532 | (@value{GDBP}) | |
3533 | @end group | |
3534 | @end smallexample | |
c906108c SS |
3535 | |
3536 | @c @ifclear BARETARGET | |
6d2ebf8b | 3537 | @node Error in Breakpoints |
d4f3574e | 3538 | @subsection ``Cannot insert breakpoints'' |
c906108c SS |
3539 | @c |
3540 | @c FIXME!! 14/6/95 Is there a real example of this? Let's use it. | |
3541 | @c | |
d4f3574e SS |
3542 | Under some operating systems, breakpoints cannot be used in a program if |
3543 | any other process is running that program. In this situation, | |
5d161b24 | 3544 | attempting to run or continue a program with a breakpoint causes |
d4f3574e SS |
3545 | @value{GDBN} to print an error message: |
3546 | ||
474c8240 | 3547 | @smallexample |
d4f3574e SS |
3548 | Cannot insert breakpoints. |
3549 | The same program may be running in another process. | |
474c8240 | 3550 | @end smallexample |
d4f3574e SS |
3551 | |
3552 | When this happens, you have three ways to proceed: | |
3553 | ||
3554 | @enumerate | |
3555 | @item | |
3556 | Remove or disable the breakpoints, then continue. | |
3557 | ||
3558 | @item | |
5d161b24 | 3559 | Suspend @value{GDBN}, and copy the file containing your program to a new |
d4f3574e | 3560 | name. Resume @value{GDBN} and use the @code{exec-file} command to specify |
5d161b24 | 3561 | that @value{GDBN} should run your program under that name. |
d4f3574e SS |
3562 | Then start your program again. |
3563 | ||
3564 | @item | |
3565 | Relink your program so that the text segment is nonsharable, using the | |
3566 | linker option @samp{-N}. The operating system limitation may not apply | |
3567 | to nonsharable executables. | |
3568 | @end enumerate | |
c906108c SS |
3569 | @c @end ifclear |
3570 | ||
d4f3574e SS |
3571 | A similar message can be printed if you request too many active |
3572 | hardware-assisted breakpoints and watchpoints: | |
3573 | ||
3574 | @c FIXME: the precise wording of this message may change; the relevant | |
3575 | @c source change is not committed yet (Sep 3, 1999). | |
3576 | @smallexample | |
3577 | Stopped; cannot insert breakpoints. | |
3578 | You may have requested too many hardware breakpoints and watchpoints. | |
3579 | @end smallexample | |
3580 | ||
3581 | @noindent | |
3582 | This message is printed when you attempt to resume the program, since | |
3583 | only then @value{GDBN} knows exactly how many hardware breakpoints and | |
3584 | watchpoints it needs to insert. | |
3585 | ||
3586 | When this message is printed, you need to disable or remove some of the | |
3587 | hardware-assisted breakpoints and watchpoints, and then continue. | |
3588 | ||
1485d690 KB |
3589 | @node Breakpoint related warnings |
3590 | @subsection ``Breakpoint address adjusted...'' | |
3591 | @cindex breakpoint address adjusted | |
3592 | ||
3593 | Some processor architectures place constraints on the addresses at | |
3594 | which breakpoints may be placed. For architectures thus constrained, | |
3595 | @value{GDBN} will attempt to adjust the breakpoint's address to comply | |
3596 | with the constraints dictated by the architecture. | |
3597 | ||
3598 | One example of such an architecture is the Fujitsu FR-V. The FR-V is | |
3599 | a VLIW architecture in which a number of RISC-like instructions may be | |
3600 | bundled together for parallel execution. The FR-V architecture | |
3601 | constrains the location of a breakpoint instruction within such a | |
3602 | bundle to the instruction with the lowest address. @value{GDBN} | |
3603 | honors this constraint by adjusting a breakpoint's address to the | |
3604 | first in the bundle. | |
3605 | ||
3606 | It is not uncommon for optimized code to have bundles which contain | |
3607 | instructions from different source statements, thus it may happen that | |
3608 | a breakpoint's address will be adjusted from one source statement to | |
3609 | another. Since this adjustment may significantly alter @value{GDBN}'s | |
3610 | breakpoint related behavior from what the user expects, a warning is | |
3611 | printed when the breakpoint is first set and also when the breakpoint | |
3612 | is hit. | |
3613 | ||
3614 | A warning like the one below is printed when setting a breakpoint | |
3615 | that's been subject to address adjustment: | |
3616 | ||
3617 | @smallexample | |
3618 | warning: Breakpoint address adjusted from 0x00010414 to 0x00010410. | |
3619 | @end smallexample | |
3620 | ||
3621 | Such warnings are printed both for user settable and @value{GDBN}'s | |
3622 | internal breakpoints. If you see one of these warnings, you should | |
3623 | verify that a breakpoint set at the adjusted address will have the | |
3624 | desired affect. If not, the breakpoint in question may be removed and | |
b383017d | 3625 | other breakpoints may be set which will have the desired behavior. |
1485d690 KB |
3626 | E.g., it may be sufficient to place the breakpoint at a later |
3627 | instruction. A conditional breakpoint may also be useful in some | |
3628 | cases to prevent the breakpoint from triggering too often. | |
3629 | ||
3630 | @value{GDBN} will also issue a warning when stopping at one of these | |
3631 | adjusted breakpoints: | |
3632 | ||
3633 | @smallexample | |
3634 | warning: Breakpoint 1 address previously adjusted from 0x00010414 | |
3635 | to 0x00010410. | |
3636 | @end smallexample | |
3637 | ||
3638 | When this warning is encountered, it may be too late to take remedial | |
3639 | action except in cases where the breakpoint is hit earlier or more | |
3640 | frequently than expected. | |
d4f3574e | 3641 | |
6d2ebf8b | 3642 | @node Continuing and Stepping |
c906108c SS |
3643 | @section Continuing and stepping |
3644 | ||
3645 | @cindex stepping | |
3646 | @cindex continuing | |
3647 | @cindex resuming execution | |
3648 | @dfn{Continuing} means resuming program execution until your program | |
3649 | completes normally. In contrast, @dfn{stepping} means executing just | |
3650 | one more ``step'' of your program, where ``step'' may mean either one | |
3651 | line of source code, or one machine instruction (depending on what | |
7a292a7a SS |
3652 | particular command you use). Either when continuing or when stepping, |
3653 | your program may stop even sooner, due to a breakpoint or a signal. (If | |
d4f3574e SS |
3654 | it stops due to a signal, you may want to use @code{handle}, or use |
3655 | @samp{signal 0} to resume execution. @xref{Signals, ,Signals}.) | |
c906108c SS |
3656 | |
3657 | @table @code | |
3658 | @kindex continue | |
41afff9a EZ |
3659 | @kindex c @r{(@code{continue})} |
3660 | @kindex fg @r{(resume foreground execution)} | |
c906108c SS |
3661 | @item continue @r{[}@var{ignore-count}@r{]} |
3662 | @itemx c @r{[}@var{ignore-count}@r{]} | |
3663 | @itemx fg @r{[}@var{ignore-count}@r{]} | |
3664 | Resume program execution, at the address where your program last stopped; | |
3665 | any breakpoints set at that address are bypassed. The optional argument | |
3666 | @var{ignore-count} allows you to specify a further number of times to | |
3667 | ignore a breakpoint at this location; its effect is like that of | |
3668 | @code{ignore} (@pxref{Conditions, ,Break conditions}). | |
3669 | ||
3670 | The argument @var{ignore-count} is meaningful only when your program | |
3671 | stopped due to a breakpoint. At other times, the argument to | |
3672 | @code{continue} is ignored. | |
3673 | ||
d4f3574e SS |
3674 | The synonyms @code{c} and @code{fg} (for @dfn{foreground}, as the |
3675 | debugged program is deemed to be the foreground program) are provided | |
3676 | purely for convenience, and have exactly the same behavior as | |
3677 | @code{continue}. | |
c906108c SS |
3678 | @end table |
3679 | ||
3680 | To resume execution at a different place, you can use @code{return} | |
3681 | (@pxref{Returning, ,Returning from a function}) to go back to the | |
3682 | calling function; or @code{jump} (@pxref{Jumping, ,Continuing at a | |
3683 | different address}) to go to an arbitrary location in your program. | |
3684 | ||
3685 | A typical technique for using stepping is to set a breakpoint | |
3686 | (@pxref{Breakpoints, ,Breakpoints; watchpoints; and catchpoints}) at the | |
3687 | beginning of the function or the section of your program where a problem | |
3688 | is believed to lie, run your program until it stops at that breakpoint, | |
3689 | and then step through the suspect area, examining the variables that are | |
3690 | interesting, until you see the problem happen. | |
3691 | ||
3692 | @table @code | |
3693 | @kindex step | |
41afff9a | 3694 | @kindex s @r{(@code{step})} |
c906108c SS |
3695 | @item step |
3696 | Continue running your program until control reaches a different source | |
3697 | line, then stop it and return control to @value{GDBN}. This command is | |
3698 | abbreviated @code{s}. | |
3699 | ||
3700 | @quotation | |
3701 | @c "without debugging information" is imprecise; actually "without line | |
3702 | @c numbers in the debugging information". (gcc -g1 has debugging info but | |
3703 | @c not line numbers). But it seems complex to try to make that | |
3704 | @c distinction here. | |
3705 | @emph{Warning:} If you use the @code{step} command while control is | |
3706 | within a function that was compiled without debugging information, | |
3707 | execution proceeds until control reaches a function that does have | |
3708 | debugging information. Likewise, it will not step into a function which | |
3709 | is compiled without debugging information. To step through functions | |
3710 | without debugging information, use the @code{stepi} command, described | |
3711 | below. | |
3712 | @end quotation | |
3713 | ||
4a92d011 EZ |
3714 | The @code{step} command only stops at the first instruction of a source |
3715 | line. This prevents the multiple stops that could otherwise occur in | |
3716 | @code{switch} statements, @code{for} loops, etc. @code{step} continues | |
3717 | to stop if a function that has debugging information is called within | |
3718 | the line. In other words, @code{step} @emph{steps inside} any functions | |
3719 | called within the line. | |
c906108c | 3720 | |
d4f3574e SS |
3721 | Also, the @code{step} command only enters a function if there is line |
3722 | number information for the function. Otherwise it acts like the | |
5d161b24 | 3723 | @code{next} command. This avoids problems when using @code{cc -gl} |
c906108c | 3724 | on MIPS machines. Previously, @code{step} entered subroutines if there |
5d161b24 | 3725 | was any debugging information about the routine. |
c906108c SS |
3726 | |
3727 | @item step @var{count} | |
3728 | Continue running as in @code{step}, but do so @var{count} times. If a | |
7a292a7a SS |
3729 | breakpoint is reached, or a signal not related to stepping occurs before |
3730 | @var{count} steps, stepping stops right away. | |
c906108c SS |
3731 | |
3732 | @kindex next | |
41afff9a | 3733 | @kindex n @r{(@code{next})} |
c906108c SS |
3734 | @item next @r{[}@var{count}@r{]} |
3735 | Continue to the next source line in the current (innermost) stack frame. | |
7a292a7a SS |
3736 | This is similar to @code{step}, but function calls that appear within |
3737 | the line of code are executed without stopping. Execution stops when | |
3738 | control reaches a different line of code at the original stack level | |
3739 | that was executing when you gave the @code{next} command. This command | |
3740 | is abbreviated @code{n}. | |
c906108c SS |
3741 | |
3742 | An argument @var{count} is a repeat count, as for @code{step}. | |
3743 | ||
3744 | ||
3745 | @c FIX ME!! Do we delete this, or is there a way it fits in with | |
3746 | @c the following paragraph? --- Vctoria | |
3747 | @c | |
3748 | @c @code{next} within a function that lacks debugging information acts like | |
3749 | @c @code{step}, but any function calls appearing within the code of the | |
3750 | @c function are executed without stopping. | |
3751 | ||
d4f3574e SS |
3752 | The @code{next} command only stops at the first instruction of a |
3753 | source line. This prevents multiple stops that could otherwise occur in | |
4a92d011 | 3754 | @code{switch} statements, @code{for} loops, etc. |
c906108c | 3755 | |
b90a5f51 CF |
3756 | @kindex set step-mode |
3757 | @item set step-mode | |
3758 | @cindex functions without line info, and stepping | |
3759 | @cindex stepping into functions with no line info | |
3760 | @itemx set step-mode on | |
4a92d011 | 3761 | The @code{set step-mode on} command causes the @code{step} command to |
b90a5f51 CF |
3762 | stop at the first instruction of a function which contains no debug line |
3763 | information rather than stepping over it. | |
3764 | ||
4a92d011 EZ |
3765 | This is useful in cases where you may be interested in inspecting the |
3766 | machine instructions of a function which has no symbolic info and do not | |
3767 | want @value{GDBN} to automatically skip over this function. | |
b90a5f51 CF |
3768 | |
3769 | @item set step-mode off | |
4a92d011 | 3770 | Causes the @code{step} command to step over any functions which contains no |
b90a5f51 CF |
3771 | debug information. This is the default. |
3772 | ||
9c16f35a EZ |
3773 | @item show step-mode |
3774 | Show whether @value{GDBN} will stop in or step over functions without | |
3775 | source line debug information. | |
3776 | ||
c906108c SS |
3777 | @kindex finish |
3778 | @item finish | |
3779 | Continue running until just after function in the selected stack frame | |
3780 | returns. Print the returned value (if any). | |
3781 | ||
3782 | Contrast this with the @code{return} command (@pxref{Returning, | |
3783 | ,Returning from a function}). | |
3784 | ||
3785 | @kindex until | |
41afff9a | 3786 | @kindex u @r{(@code{until})} |
09d4efe1 | 3787 | @cindex run until specified location |
c906108c SS |
3788 | @item until |
3789 | @itemx u | |
3790 | Continue running until a source line past the current line, in the | |
3791 | current stack frame, is reached. This command is used to avoid single | |
3792 | stepping through a loop more than once. It is like the @code{next} | |
3793 | command, except that when @code{until} encounters a jump, it | |
3794 | automatically continues execution until the program counter is greater | |
3795 | than the address of the jump. | |
3796 | ||
3797 | This means that when you reach the end of a loop after single stepping | |
3798 | though it, @code{until} makes your program continue execution until it | |
3799 | exits the loop. In contrast, a @code{next} command at the end of a loop | |
3800 | simply steps back to the beginning of the loop, which forces you to step | |
3801 | through the next iteration. | |
3802 | ||
3803 | @code{until} always stops your program if it attempts to exit the current | |
3804 | stack frame. | |
3805 | ||
3806 | @code{until} may produce somewhat counterintuitive results if the order | |
3807 | of machine code does not match the order of the source lines. For | |
3808 | example, in the following excerpt from a debugging session, the @code{f} | |
3809 | (@code{frame}) command shows that execution is stopped at line | |
3810 | @code{206}; yet when we use @code{until}, we get to line @code{195}: | |
3811 | ||
474c8240 | 3812 | @smallexample |
c906108c SS |
3813 | (@value{GDBP}) f |
3814 | #0 main (argc=4, argv=0xf7fffae8) at m4.c:206 | |
3815 | 206 expand_input(); | |
3816 | (@value{GDBP}) until | |
3817 | 195 for ( ; argc > 0; NEXTARG) @{ | |
474c8240 | 3818 | @end smallexample |
c906108c SS |
3819 | |
3820 | This happened because, for execution efficiency, the compiler had | |
3821 | generated code for the loop closure test at the end, rather than the | |
3822 | start, of the loop---even though the test in a C @code{for}-loop is | |
3823 | written before the body of the loop. The @code{until} command appeared | |
3824 | to step back to the beginning of the loop when it advanced to this | |
3825 | expression; however, it has not really gone to an earlier | |
3826 | statement---not in terms of the actual machine code. | |
3827 | ||
3828 | @code{until} with no argument works by means of single | |
3829 | instruction stepping, and hence is slower than @code{until} with an | |
3830 | argument. | |
3831 | ||
3832 | @item until @var{location} | |
3833 | @itemx u @var{location} | |
3834 | Continue running your program until either the specified location is | |
3835 | reached, or the current stack frame returns. @var{location} is any of | |
3836 | the forms of argument acceptable to @code{break} (@pxref{Set Breaks, | |
c60eb6f1 EZ |
3837 | ,Setting breakpoints}). This form of the command uses breakpoints, and |
3838 | hence is quicker than @code{until} without an argument. The specified | |
3839 | location is actually reached only if it is in the current frame. This | |
3840 | implies that @code{until} can be used to skip over recursive function | |
3841 | invocations. For instance in the code below, if the current location is | |
3842 | line @code{96}, issuing @code{until 99} will execute the program up to | |
3843 | line @code{99} in the same invocation of factorial, i.e. after the inner | |
3844 | invocations have returned. | |
3845 | ||
3846 | @smallexample | |
3847 | 94 int factorial (int value) | |
3848 | 95 @{ | |
3849 | 96 if (value > 1) @{ | |
3850 | 97 value *= factorial (value - 1); | |
3851 | 98 @} | |
3852 | 99 return (value); | |
3853 | 100 @} | |
3854 | @end smallexample | |
3855 | ||
3856 | ||
3857 | @kindex advance @var{location} | |
3858 | @itemx advance @var{location} | |
09d4efe1 EZ |
3859 | Continue running the program up to the given @var{location}. An argument is |
3860 | required, which should be of the same form as arguments for the @code{break} | |
c60eb6f1 EZ |
3861 | command. Execution will also stop upon exit from the current stack |
3862 | frame. This command is similar to @code{until}, but @code{advance} will | |
3863 | not skip over recursive function calls, and the target location doesn't | |
3864 | have to be in the same frame as the current one. | |
3865 | ||
c906108c SS |
3866 | |
3867 | @kindex stepi | |
41afff9a | 3868 | @kindex si @r{(@code{stepi})} |
c906108c | 3869 | @item stepi |
96a2c332 | 3870 | @itemx stepi @var{arg} |
c906108c SS |
3871 | @itemx si |
3872 | Execute one machine instruction, then stop and return to the debugger. | |
3873 | ||
3874 | It is often useful to do @samp{display/i $pc} when stepping by machine | |
3875 | instructions. This makes @value{GDBN} automatically display the next | |
3876 | instruction to be executed, each time your program stops. @xref{Auto | |
3877 | Display,, Automatic display}. | |
3878 | ||
3879 | An argument is a repeat count, as in @code{step}. | |
3880 | ||
3881 | @need 750 | |
3882 | @kindex nexti | |
41afff9a | 3883 | @kindex ni @r{(@code{nexti})} |
c906108c | 3884 | @item nexti |
96a2c332 | 3885 | @itemx nexti @var{arg} |
c906108c SS |
3886 | @itemx ni |
3887 | Execute one machine instruction, but if it is a function call, | |
3888 | proceed until the function returns. | |
3889 | ||
3890 | An argument is a repeat count, as in @code{next}. | |
3891 | @end table | |
3892 | ||
6d2ebf8b | 3893 | @node Signals |
c906108c SS |
3894 | @section Signals |
3895 | @cindex signals | |
3896 | ||
3897 | A signal is an asynchronous event that can happen in a program. The | |
3898 | operating system defines the possible kinds of signals, and gives each | |
3899 | kind a name and a number. For example, in Unix @code{SIGINT} is the | |
d4f3574e | 3900 | signal a program gets when you type an interrupt character (often @kbd{C-c}); |
c906108c SS |
3901 | @code{SIGSEGV} is the signal a program gets from referencing a place in |
3902 | memory far away from all the areas in use; @code{SIGALRM} occurs when | |
3903 | the alarm clock timer goes off (which happens only if your program has | |
3904 | requested an alarm). | |
3905 | ||
3906 | @cindex fatal signals | |
3907 | Some signals, including @code{SIGALRM}, are a normal part of the | |
3908 | functioning of your program. Others, such as @code{SIGSEGV}, indicate | |
d4f3574e | 3909 | errors; these signals are @dfn{fatal} (they kill your program immediately) if the |
c906108c SS |
3910 | program has not specified in advance some other way to handle the signal. |
3911 | @code{SIGINT} does not indicate an error in your program, but it is normally | |
3912 | fatal so it can carry out the purpose of the interrupt: to kill the program. | |
3913 | ||
3914 | @value{GDBN} has the ability to detect any occurrence of a signal in your | |
3915 | program. You can tell @value{GDBN} in advance what to do for each kind of | |
3916 | signal. | |
3917 | ||
3918 | @cindex handling signals | |
24f93129 EZ |
3919 | Normally, @value{GDBN} is set up to let the non-erroneous signals like |
3920 | @code{SIGALRM} be silently passed to your program | |
3921 | (so as not to interfere with their role in the program's functioning) | |
c906108c SS |
3922 | but to stop your program immediately whenever an error signal happens. |
3923 | You can change these settings with the @code{handle} command. | |
3924 | ||
3925 | @table @code | |
3926 | @kindex info signals | |
09d4efe1 | 3927 | @kindex info handle |
c906108c | 3928 | @item info signals |
96a2c332 | 3929 | @itemx info handle |
c906108c SS |
3930 | Print a table of all the kinds of signals and how @value{GDBN} has been told to |
3931 | handle each one. You can use this to see the signal numbers of all | |
3932 | the defined types of signals. | |
3933 | ||
d4f3574e | 3934 | @code{info handle} is an alias for @code{info signals}. |
c906108c SS |
3935 | |
3936 | @kindex handle | |
3937 | @item handle @var{signal} @var{keywords}@dots{} | |
5ece1a18 EZ |
3938 | Change the way @value{GDBN} handles signal @var{signal}. @var{signal} |
3939 | can be the number of a signal or its name (with or without the | |
24f93129 | 3940 | @samp{SIG} at the beginning); a list of signal numbers of the form |
5ece1a18 EZ |
3941 | @samp{@var{low}-@var{high}}; or the word @samp{all}, meaning all the |
3942 | known signals. The @var{keywords} say what change to make. | |
c906108c SS |
3943 | @end table |
3944 | ||
3945 | @c @group | |
3946 | The keywords allowed by the @code{handle} command can be abbreviated. | |
3947 | Their full names are: | |
3948 | ||
3949 | @table @code | |
3950 | @item nostop | |
3951 | @value{GDBN} should not stop your program when this signal happens. It may | |
3952 | still print a message telling you that the signal has come in. | |
3953 | ||
3954 | @item stop | |
3955 | @value{GDBN} should stop your program when this signal happens. This implies | |
3956 | the @code{print} keyword as well. | |
3957 | ||
3958 | @item print | |
3959 | @value{GDBN} should print a message when this signal happens. | |
3960 | ||
3961 | @item noprint | |
3962 | @value{GDBN} should not mention the occurrence of the signal at all. This | |
3963 | implies the @code{nostop} keyword as well. | |
3964 | ||
3965 | @item pass | |
5ece1a18 | 3966 | @itemx noignore |
c906108c SS |
3967 | @value{GDBN} should allow your program to see this signal; your program |
3968 | can handle the signal, or else it may terminate if the signal is fatal | |
5ece1a18 | 3969 | and not handled. @code{pass} and @code{noignore} are synonyms. |
c906108c SS |
3970 | |
3971 | @item nopass | |
5ece1a18 | 3972 | @itemx ignore |
c906108c | 3973 | @value{GDBN} should not allow your program to see this signal. |
5ece1a18 | 3974 | @code{nopass} and @code{ignore} are synonyms. |
c906108c SS |
3975 | @end table |
3976 | @c @end group | |
3977 | ||
d4f3574e SS |
3978 | When a signal stops your program, the signal is not visible to the |
3979 | program until you | |
c906108c SS |
3980 | continue. Your program sees the signal then, if @code{pass} is in |
3981 | effect for the signal in question @emph{at that time}. In other words, | |
3982 | after @value{GDBN} reports a signal, you can use the @code{handle} | |
3983 | command with @code{pass} or @code{nopass} to control whether your | |
3984 | program sees that signal when you continue. | |
3985 | ||
24f93129 EZ |
3986 | The default is set to @code{nostop}, @code{noprint}, @code{pass} for |
3987 | non-erroneous signals such as @code{SIGALRM}, @code{SIGWINCH} and | |
3988 | @code{SIGCHLD}, and to @code{stop}, @code{print}, @code{pass} for the | |
3989 | erroneous signals. | |
3990 | ||
c906108c SS |
3991 | You can also use the @code{signal} command to prevent your program from |
3992 | seeing a signal, or cause it to see a signal it normally would not see, | |
3993 | or to give it any signal at any time. For example, if your program stopped | |
3994 | due to some sort of memory reference error, you might store correct | |
3995 | values into the erroneous variables and continue, hoping to see more | |
3996 | execution; but your program would probably terminate immediately as | |
3997 | a result of the fatal signal once it saw the signal. To prevent this, | |
3998 | you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your | |
5d161b24 | 3999 | program a signal}. |
c906108c | 4000 | |
6d2ebf8b | 4001 | @node Thread Stops |
c906108c SS |
4002 | @section Stopping and starting multi-thread programs |
4003 | ||
4004 | When your program has multiple threads (@pxref{Threads,, Debugging | |
4005 | programs with multiple threads}), you can choose whether to set | |
4006 | breakpoints on all threads, or on a particular thread. | |
4007 | ||
4008 | @table @code | |
4009 | @cindex breakpoints and threads | |
4010 | @cindex thread breakpoints | |
4011 | @kindex break @dots{} thread @var{threadno} | |
4012 | @item break @var{linespec} thread @var{threadno} | |
4013 | @itemx break @var{linespec} thread @var{threadno} if @dots{} | |
4014 | @var{linespec} specifies source lines; there are several ways of | |
4015 | writing them, but the effect is always to specify some source line. | |
4016 | ||
4017 | Use the qualifier @samp{thread @var{threadno}} with a breakpoint command | |
4018 | to specify that you only want @value{GDBN} to stop the program when a | |
4019 | particular thread reaches this breakpoint. @var{threadno} is one of the | |
4020 | numeric thread identifiers assigned by @value{GDBN}, shown in the first | |
4021 | column of the @samp{info threads} display. | |
4022 | ||
4023 | If you do not specify @samp{thread @var{threadno}} when you set a | |
4024 | breakpoint, the breakpoint applies to @emph{all} threads of your | |
4025 | program. | |
4026 | ||
4027 | You can use the @code{thread} qualifier on conditional breakpoints as | |
4028 | well; in this case, place @samp{thread @var{threadno}} before the | |
4029 | breakpoint condition, like this: | |
4030 | ||
4031 | @smallexample | |
2df3850c | 4032 | (@value{GDBP}) break frik.c:13 thread 28 if bartab > lim |
c906108c SS |
4033 | @end smallexample |
4034 | ||
4035 | @end table | |
4036 | ||
4037 | @cindex stopped threads | |
4038 | @cindex threads, stopped | |
4039 | Whenever your program stops under @value{GDBN} for any reason, | |
4040 | @emph{all} threads of execution stop, not just the current thread. This | |
4041 | allows you to examine the overall state of the program, including | |
4042 | switching between threads, without worrying that things may change | |
4043 | underfoot. | |
4044 | ||
36d86913 MC |
4045 | @cindex thread breakpoints and system calls |
4046 | @cindex system calls and thread breakpoints | |
4047 | @cindex premature return from system calls | |
4048 | There is an unfortunate side effect. If one thread stops for a | |
4049 | breakpoint, or for some other reason, and another thread is blocked in a | |
4050 | system call, then the system call may return prematurely. This is a | |
4051 | consequence of the interaction between multiple threads and the signals | |
4052 | that @value{GDBN} uses to implement breakpoints and other events that | |
4053 | stop execution. | |
4054 | ||
4055 | To handle this problem, your program should check the return value of | |
4056 | each system call and react appropriately. This is good programming | |
4057 | style anyways. | |
4058 | ||
4059 | For example, do not write code like this: | |
4060 | ||
4061 | @smallexample | |
4062 | sleep (10); | |
4063 | @end smallexample | |
4064 | ||
4065 | The call to @code{sleep} will return early if a different thread stops | |
4066 | at a breakpoint or for some other reason. | |
4067 | ||
4068 | Instead, write this: | |
4069 | ||
4070 | @smallexample | |
4071 | int unslept = 10; | |
4072 | while (unslept > 0) | |
4073 | unslept = sleep (unslept); | |
4074 | @end smallexample | |
4075 | ||
4076 | A system call is allowed to return early, so the system is still | |
4077 | conforming to its specification. But @value{GDBN} does cause your | |
4078 | multi-threaded program to behave differently than it would without | |
4079 | @value{GDBN}. | |
4080 | ||
4081 | Also, @value{GDBN} uses internal breakpoints in the thread library to | |
4082 | monitor certain events such as thread creation and thread destruction. | |
4083 | When such an event happens, a system call in another thread may return | |
4084 | prematurely, even though your program does not appear to stop. | |
4085 | ||
c906108c SS |
4086 | @cindex continuing threads |
4087 | @cindex threads, continuing | |
4088 | Conversely, whenever you restart the program, @emph{all} threads start | |
4089 | executing. @emph{This is true even when single-stepping} with commands | |
5d161b24 | 4090 | like @code{step} or @code{next}. |
c906108c SS |
4091 | |
4092 | In particular, @value{GDBN} cannot single-step all threads in lockstep. | |
4093 | Since thread scheduling is up to your debugging target's operating | |
4094 | system (not controlled by @value{GDBN}), other threads may | |
4095 | execute more than one statement while the current thread completes a | |
4096 | single step. Moreover, in general other threads stop in the middle of a | |
4097 | statement, rather than at a clean statement boundary, when the program | |
4098 | stops. | |
4099 | ||
4100 | You might even find your program stopped in another thread after | |
4101 | continuing or even single-stepping. This happens whenever some other | |
4102 | thread runs into a breakpoint, a signal, or an exception before the | |
4103 | first thread completes whatever you requested. | |
4104 | ||
4105 | On some OSes, you can lock the OS scheduler and thus allow only a single | |
4106 | thread to run. | |
4107 | ||
4108 | @table @code | |
4109 | @item set scheduler-locking @var{mode} | |
9c16f35a EZ |
4110 | @cindex scheduler locking mode |
4111 | @cindex lock scheduler | |
c906108c SS |
4112 | Set the scheduler locking mode. If it is @code{off}, then there is no |
4113 | locking and any thread may run at any time. If @code{on}, then only the | |
4114 | current thread may run when the inferior is resumed. The @code{step} | |
4115 | mode optimizes for single-stepping. It stops other threads from | |
4116 | ``seizing the prompt'' by preempting the current thread while you are | |
4117 | stepping. Other threads will only rarely (or never) get a chance to run | |
d4f3574e | 4118 | when you step. They are more likely to run when you @samp{next} over a |
c906108c | 4119 | function call, and they are completely free to run when you use commands |
d4f3574e | 4120 | like @samp{continue}, @samp{until}, or @samp{finish}. However, unless another |
c906108c | 4121 | thread hits a breakpoint during its timeslice, they will never steal the |
2df3850c | 4122 | @value{GDBN} prompt away from the thread that you are debugging. |
c906108c SS |
4123 | |
4124 | @item show scheduler-locking | |
4125 | Display the current scheduler locking mode. | |
4126 | @end table | |
4127 | ||
c906108c | 4128 | |
6d2ebf8b | 4129 | @node Stack |
c906108c SS |
4130 | @chapter Examining the Stack |
4131 | ||
4132 | When your program has stopped, the first thing you need to know is where it | |
4133 | stopped and how it got there. | |
4134 | ||
4135 | @cindex call stack | |
5d161b24 DB |
4136 | Each time your program performs a function call, information about the call |
4137 | is generated. | |
4138 | That information includes the location of the call in your program, | |
4139 | the arguments of the call, | |
c906108c | 4140 | and the local variables of the function being called. |
5d161b24 | 4141 | The information is saved in a block of data called a @dfn{stack frame}. |
c906108c SS |
4142 | The stack frames are allocated in a region of memory called the @dfn{call |
4143 | stack}. | |
4144 | ||
4145 | When your program stops, the @value{GDBN} commands for examining the | |
4146 | stack allow you to see all of this information. | |
4147 | ||
4148 | @cindex selected frame | |
4149 | One of the stack frames is @dfn{selected} by @value{GDBN} and many | |
4150 | @value{GDBN} commands refer implicitly to the selected frame. In | |
4151 | particular, whenever you ask @value{GDBN} for the value of a variable in | |
4152 | your program, the value is found in the selected frame. There are | |
4153 | special @value{GDBN} commands to select whichever frame you are | |
4154 | interested in. @xref{Selection, ,Selecting a frame}. | |
4155 | ||
4156 | When your program stops, @value{GDBN} automatically selects the | |
5d161b24 | 4157 | currently executing frame and describes it briefly, similar to the |
c906108c SS |
4158 | @code{frame} command (@pxref{Frame Info, ,Information about a frame}). |
4159 | ||
4160 | @menu | |
4161 | * Frames:: Stack frames | |
4162 | * Backtrace:: Backtraces | |
4163 | * Selection:: Selecting a frame | |
4164 | * Frame Info:: Information on a frame | |
c906108c SS |
4165 | |
4166 | @end menu | |
4167 | ||
6d2ebf8b | 4168 | @node Frames |
c906108c SS |
4169 | @section Stack frames |
4170 | ||
d4f3574e | 4171 | @cindex frame, definition |
c906108c SS |
4172 | @cindex stack frame |
4173 | The call stack is divided up into contiguous pieces called @dfn{stack | |
4174 | frames}, or @dfn{frames} for short; each frame is the data associated | |
4175 | with one call to one function. The frame contains the arguments given | |
4176 | to the function, the function's local variables, and the address at | |
4177 | which the function is executing. | |
4178 | ||
4179 | @cindex initial frame | |
4180 | @cindex outermost frame | |
4181 | @cindex innermost frame | |
4182 | When your program is started, the stack has only one frame, that of the | |
4183 | function @code{main}. This is called the @dfn{initial} frame or the | |
4184 | @dfn{outermost} frame. Each time a function is called, a new frame is | |
4185 | made. Each time a function returns, the frame for that function invocation | |
4186 | is eliminated. If a function is recursive, there can be many frames for | |
4187 | the same function. The frame for the function in which execution is | |
4188 | actually occurring is called the @dfn{innermost} frame. This is the most | |
4189 | recently created of all the stack frames that still exist. | |
4190 | ||
4191 | @cindex frame pointer | |
4192 | Inside your program, stack frames are identified by their addresses. A | |
4193 | stack frame consists of many bytes, each of which has its own address; each | |
4194 | kind of computer has a convention for choosing one byte whose | |
4195 | address serves as the address of the frame. Usually this address is kept | |
e09f16f9 EZ |
4196 | in a register called the @dfn{frame pointer register} |
4197 | (@pxref{Registers, $fp}) while execution is going on in that frame. | |
c906108c SS |
4198 | |
4199 | @cindex frame number | |
4200 | @value{GDBN} assigns numbers to all existing stack frames, starting with | |
4201 | zero for the innermost frame, one for the frame that called it, | |
4202 | and so on upward. These numbers do not really exist in your program; | |
4203 | they are assigned by @value{GDBN} to give you a way of designating stack | |
4204 | frames in @value{GDBN} commands. | |
4205 | ||
6d2ebf8b SS |
4206 | @c The -fomit-frame-pointer below perennially causes hbox overflow |
4207 | @c underflow problems. | |
c906108c SS |
4208 | @cindex frameless execution |
4209 | Some compilers provide a way to compile functions so that they operate | |
6d2ebf8b | 4210 | without stack frames. (For example, the @value{GCC} option |
474c8240 | 4211 | @smallexample |
6d2ebf8b | 4212 | @samp{-fomit-frame-pointer} |
474c8240 | 4213 | @end smallexample |
6d2ebf8b | 4214 | generates functions without a frame.) |
c906108c SS |
4215 | This is occasionally done with heavily used library functions to save |
4216 | the frame setup time. @value{GDBN} has limited facilities for dealing | |
4217 | with these function invocations. If the innermost function invocation | |
4218 | has no stack frame, @value{GDBN} nevertheless regards it as though | |
4219 | it had a separate frame, which is numbered zero as usual, allowing | |
4220 | correct tracing of the function call chain. However, @value{GDBN} has | |
4221 | no provision for frameless functions elsewhere in the stack. | |
4222 | ||
4223 | @table @code | |
d4f3574e | 4224 | @kindex frame@r{, command} |
41afff9a | 4225 | @cindex current stack frame |
c906108c | 4226 | @item frame @var{args} |
5d161b24 | 4227 | The @code{frame} command allows you to move from one stack frame to another, |
c906108c | 4228 | and to print the stack frame you select. @var{args} may be either the |
5d161b24 DB |
4229 | address of the frame or the stack frame number. Without an argument, |
4230 | @code{frame} prints the current stack frame. | |
c906108c SS |
4231 | |
4232 | @kindex select-frame | |
41afff9a | 4233 | @cindex selecting frame silently |
c906108c SS |
4234 | @item select-frame |
4235 | The @code{select-frame} command allows you to move from one stack frame | |
4236 | to another without printing the frame. This is the silent version of | |
4237 | @code{frame}. | |
4238 | @end table | |
4239 | ||
6d2ebf8b | 4240 | @node Backtrace |
c906108c SS |
4241 | @section Backtraces |
4242 | ||
09d4efe1 EZ |
4243 | @cindex traceback |
4244 | @cindex call stack traces | |
c906108c SS |
4245 | A backtrace is a summary of how your program got where it is. It shows one |
4246 | line per frame, for many frames, starting with the currently executing | |
4247 | frame (frame zero), followed by its caller (frame one), and on up the | |
4248 | stack. | |
4249 | ||
4250 | @table @code | |
4251 | @kindex backtrace | |
41afff9a | 4252 | @kindex bt @r{(@code{backtrace})} |
c906108c SS |
4253 | @item backtrace |
4254 | @itemx bt | |
4255 | Print a backtrace of the entire stack: one line per frame for all | |
4256 | frames in the stack. | |
4257 | ||
4258 | You can stop the backtrace at any time by typing the system interrupt | |
4259 | character, normally @kbd{C-c}. | |
4260 | ||
4261 | @item backtrace @var{n} | |
4262 | @itemx bt @var{n} | |
4263 | Similar, but print only the innermost @var{n} frames. | |
4264 | ||
4265 | @item backtrace -@var{n} | |
4266 | @itemx bt -@var{n} | |
4267 | Similar, but print only the outermost @var{n} frames. | |
0f061b69 NR |
4268 | |
4269 | @item backtrace full | |
4270 | Print the values of the local variables also. | |
4271 | @itemx bt full | |
c906108c SS |
4272 | @end table |
4273 | ||
4274 | @kindex where | |
4275 | @kindex info stack | |
c906108c SS |
4276 | The names @code{where} and @code{info stack} (abbreviated @code{info s}) |
4277 | are additional aliases for @code{backtrace}. | |
4278 | ||
4279 | Each line in the backtrace shows the frame number and the function name. | |
4280 | The program counter value is also shown---unless you use @code{set | |
4281 | print address off}. The backtrace also shows the source file name and | |
4282 | line number, as well as the arguments to the function. The program | |
4283 | counter value is omitted if it is at the beginning of the code for that | |
4284 | line number. | |
4285 | ||
4286 | Here is an example of a backtrace. It was made with the command | |
4287 | @samp{bt 3}, so it shows the innermost three frames. | |
4288 | ||
4289 | @smallexample | |
4290 | @group | |
5d161b24 | 4291 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) |
c906108c SS |
4292 | at builtin.c:993 |
4293 | #1 0x6e38 in expand_macro (sym=0x2b600) at macro.c:242 | |
4294 | #2 0x6840 in expand_token (obs=0x0, t=177664, td=0xf7fffb08) | |
4295 | at macro.c:71 | |
4296 | (More stack frames follow...) | |
4297 | @end group | |
4298 | @end smallexample | |
4299 | ||
4300 | @noindent | |
4301 | The display for frame zero does not begin with a program counter | |
4302 | value, indicating that your program has stopped at the beginning of the | |
4303 | code for line @code{993} of @code{builtin.c}. | |
4304 | ||
18999be5 EZ |
4305 | @cindex value optimized out, in backtrace |
4306 | @cindex function call arguments, optimized out | |
4307 | If your program was compiled with optimizations, some compilers will | |
4308 | optimize away arguments passed to functions if those arguments are | |
4309 | never used after the call. Such optimizations generate code that | |
4310 | passes arguments through registers, but doesn't store those arguments | |
4311 | in the stack frame. @value{GDBN} has no way of displaying such | |
4312 | arguments in stack frames other than the innermost one. Here's what | |
4313 | such a backtrace might look like: | |
4314 | ||
4315 | @smallexample | |
4316 | @group | |
4317 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) | |
4318 | at builtin.c:993 | |
4319 | #1 0x6e38 in expand_macro (sym=<value optimized out>) at macro.c:242 | |
4320 | #2 0x6840 in expand_token (obs=0x0, t=<value optimized out>, td=0xf7fffb08) | |
4321 | at macro.c:71 | |
4322 | (More stack frames follow...) | |
4323 | @end group | |
4324 | @end smallexample | |
4325 | ||
4326 | @noindent | |
4327 | The values of arguments that were not saved in their stack frames are | |
4328 | shown as @samp{<value optimized out>}. | |
4329 | ||
4330 | If you need to display the values of such optimized-out arguments, | |
4331 | either deduce that from other variables whose values depend on the one | |
4332 | you are interested in, or recompile without optimizations. | |
4333 | ||
a8f24a35 EZ |
4334 | @cindex backtrace beyond @code{main} function |
4335 | @cindex program entry point | |
4336 | @cindex startup code, and backtrace | |
25d29d70 AC |
4337 | Most programs have a standard user entry point---a place where system |
4338 | libraries and startup code transition into user code. For C this is | |
d416eeec EZ |
4339 | @code{main}@footnote{ |
4340 | Note that embedded programs (the so-called ``free-standing'' | |
4341 | environment) are not required to have a @code{main} function as the | |
4342 | entry point. They could even have multiple entry points.}. | |
4343 | When @value{GDBN} finds the entry function in a backtrace | |
25d29d70 AC |
4344 | it will terminate the backtrace, to avoid tracing into highly |
4345 | system-specific (and generally uninteresting) code. | |
4346 | ||
4347 | If you need to examine the startup code, or limit the number of levels | |
4348 | in a backtrace, you can change this behavior: | |
95f90d25 DJ |
4349 | |
4350 | @table @code | |
25d29d70 AC |
4351 | @item set backtrace past-main |
4352 | @itemx set backtrace past-main on | |
4644b6e3 | 4353 | @kindex set backtrace |
25d29d70 AC |
4354 | Backtraces will continue past the user entry point. |
4355 | ||
4356 | @item set backtrace past-main off | |
95f90d25 DJ |
4357 | Backtraces will stop when they encounter the user entry point. This is the |
4358 | default. | |
4359 | ||
25d29d70 | 4360 | @item show backtrace past-main |
4644b6e3 | 4361 | @kindex show backtrace |
25d29d70 AC |
4362 | Display the current user entry point backtrace policy. |
4363 | ||
2315ffec RC |
4364 | @item set backtrace past-entry |
4365 | @itemx set backtrace past-entry on | |
a8f24a35 | 4366 | Backtraces will continue past the internal entry point of an application. |
2315ffec RC |
4367 | This entry point is encoded by the linker when the application is built, |
4368 | and is likely before the user entry point @code{main} (or equivalent) is called. | |
4369 | ||
4370 | @item set backtrace past-entry off | |
4371 | Backtraces will stop when they encouter the internal entry point of an | |
4372 | application. This is the default. | |
4373 | ||
4374 | @item show backtrace past-entry | |
4375 | Display the current internal entry point backtrace policy. | |
4376 | ||
25d29d70 AC |
4377 | @item set backtrace limit @var{n} |
4378 | @itemx set backtrace limit 0 | |
4379 | @cindex backtrace limit | |
4380 | Limit the backtrace to @var{n} levels. A value of zero means | |
4381 | unlimited. | |
95f90d25 | 4382 | |
25d29d70 AC |
4383 | @item show backtrace limit |
4384 | Display the current limit on backtrace levels. | |
95f90d25 DJ |
4385 | @end table |
4386 | ||
6d2ebf8b | 4387 | @node Selection |
c906108c SS |
4388 | @section Selecting a frame |
4389 | ||
4390 | Most commands for examining the stack and other data in your program work on | |
4391 | whichever stack frame is selected at the moment. Here are the commands for | |
4392 | selecting a stack frame; all of them finish by printing a brief description | |
4393 | of the stack frame just selected. | |
4394 | ||
4395 | @table @code | |
d4f3574e | 4396 | @kindex frame@r{, selecting} |
41afff9a | 4397 | @kindex f @r{(@code{frame})} |
c906108c SS |
4398 | @item frame @var{n} |
4399 | @itemx f @var{n} | |
4400 | Select frame number @var{n}. Recall that frame zero is the innermost | |
4401 | (currently executing) frame, frame one is the frame that called the | |
4402 | innermost one, and so on. The highest-numbered frame is the one for | |
4403 | @code{main}. | |
4404 | ||
4405 | @item frame @var{addr} | |
4406 | @itemx f @var{addr} | |
4407 | Select the frame at address @var{addr}. This is useful mainly if the | |
4408 | chaining of stack frames has been damaged by a bug, making it | |
4409 | impossible for @value{GDBN} to assign numbers properly to all frames. In | |
4410 | addition, this can be useful when your program has multiple stacks and | |
4411 | switches between them. | |
4412 | ||
c906108c SS |
4413 | On the SPARC architecture, @code{frame} needs two addresses to |
4414 | select an arbitrary frame: a frame pointer and a stack pointer. | |
4415 | ||
4416 | On the MIPS and Alpha architecture, it needs two addresses: a stack | |
4417 | pointer and a program counter. | |
4418 | ||
4419 | On the 29k architecture, it needs three addresses: a register stack | |
4420 | pointer, a program counter, and a memory stack pointer. | |
c906108c SS |
4421 | |
4422 | @kindex up | |
4423 | @item up @var{n} | |
4424 | Move @var{n} frames up the stack. For positive numbers @var{n}, this | |
4425 | advances toward the outermost frame, to higher frame numbers, to frames | |
4426 | that have existed longer. @var{n} defaults to one. | |
4427 | ||
4428 | @kindex down | |
41afff9a | 4429 | @kindex do @r{(@code{down})} |
c906108c SS |
4430 | @item down @var{n} |
4431 | Move @var{n} frames down the stack. For positive numbers @var{n}, this | |
4432 | advances toward the innermost frame, to lower frame numbers, to frames | |
4433 | that were created more recently. @var{n} defaults to one. You may | |
4434 | abbreviate @code{down} as @code{do}. | |
4435 | @end table | |
4436 | ||
4437 | All of these commands end by printing two lines of output describing the | |
4438 | frame. The first line shows the frame number, the function name, the | |
4439 | arguments, and the source file and line number of execution in that | |
5d161b24 | 4440 | frame. The second line shows the text of that source line. |
c906108c SS |
4441 | |
4442 | @need 1000 | |
4443 | For example: | |
4444 | ||
4445 | @smallexample | |
4446 | @group | |
4447 | (@value{GDBP}) up | |
4448 | #1 0x22f0 in main (argc=1, argv=0xf7fffbf4, env=0xf7fffbfc) | |
4449 | at env.c:10 | |
4450 | 10 read_input_file (argv[i]); | |
4451 | @end group | |
4452 | @end smallexample | |
4453 | ||
4454 | After such a printout, the @code{list} command with no arguments | |
4455 | prints ten lines centered on the point of execution in the frame. | |
87885426 FN |
4456 | You can also edit the program at the point of execution with your favorite |
4457 | editing program by typing @code{edit}. | |
4458 | @xref{List, ,Printing source lines}, | |
4459 | for details. | |
c906108c SS |
4460 | |
4461 | @table @code | |
4462 | @kindex down-silently | |
4463 | @kindex up-silently | |
4464 | @item up-silently @var{n} | |
4465 | @itemx down-silently @var{n} | |
4466 | These two commands are variants of @code{up} and @code{down}, | |
4467 | respectively; they differ in that they do their work silently, without | |
4468 | causing display of the new frame. They are intended primarily for use | |
4469 | in @value{GDBN} command scripts, where the output might be unnecessary and | |
4470 | distracting. | |
4471 | @end table | |
4472 | ||
6d2ebf8b | 4473 | @node Frame Info |
c906108c SS |
4474 | @section Information about a frame |
4475 | ||
4476 | There are several other commands to print information about the selected | |
4477 | stack frame. | |
4478 | ||
4479 | @table @code | |
4480 | @item frame | |
4481 | @itemx f | |
4482 | When used without any argument, this command does not change which | |
4483 | frame is selected, but prints a brief description of the currently | |
4484 | selected stack frame. It can be abbreviated @code{f}. With an | |
4485 | argument, this command is used to select a stack frame. | |
4486 | @xref{Selection, ,Selecting a frame}. | |
4487 | ||
4488 | @kindex info frame | |
41afff9a | 4489 | @kindex info f @r{(@code{info frame})} |
c906108c SS |
4490 | @item info frame |
4491 | @itemx info f | |
4492 | This command prints a verbose description of the selected stack frame, | |
4493 | including: | |
4494 | ||
4495 | @itemize @bullet | |
5d161b24 DB |
4496 | @item |
4497 | the address of the frame | |
c906108c SS |
4498 | @item |
4499 | the address of the next frame down (called by this frame) | |
4500 | @item | |
4501 | the address of the next frame up (caller of this frame) | |
4502 | @item | |
4503 | the language in which the source code corresponding to this frame is written | |
4504 | @item | |
4505 | the address of the frame's arguments | |
4506 | @item | |
d4f3574e SS |
4507 | the address of the frame's local variables |
4508 | @item | |
c906108c SS |
4509 | the program counter saved in it (the address of execution in the caller frame) |
4510 | @item | |
4511 | which registers were saved in the frame | |
4512 | @end itemize | |
4513 | ||
4514 | @noindent The verbose description is useful when | |
4515 | something has gone wrong that has made the stack format fail to fit | |
4516 | the usual conventions. | |
4517 | ||
4518 | @item info frame @var{addr} | |
4519 | @itemx info f @var{addr} | |
4520 | Print a verbose description of the frame at address @var{addr}, without | |
4521 | selecting that frame. The selected frame remains unchanged by this | |
4522 | command. This requires the same kind of address (more than one for some | |
4523 | architectures) that you specify in the @code{frame} command. | |
4524 | @xref{Selection, ,Selecting a frame}. | |
4525 | ||
4526 | @kindex info args | |
4527 | @item info args | |
4528 | Print the arguments of the selected frame, each on a separate line. | |
4529 | ||
4530 | @item info locals | |
4531 | @kindex info locals | |
4532 | Print the local variables of the selected frame, each on a separate | |
4533 | line. These are all variables (declared either static or automatic) | |
4534 | accessible at the point of execution of the selected frame. | |
4535 | ||
c906108c | 4536 | @kindex info catch |
d4f3574e SS |
4537 | @cindex catch exceptions, list active handlers |
4538 | @cindex exception handlers, how to list | |
c906108c SS |
4539 | @item info catch |
4540 | Print a list of all the exception handlers that are active in the | |
4541 | current stack frame at the current point of execution. To see other | |
4542 | exception handlers, visit the associated frame (using the @code{up}, | |
4543 | @code{down}, or @code{frame} commands); then type @code{info catch}. | |
4544 | @xref{Set Catchpoints, , Setting catchpoints}. | |
53a5351d | 4545 | |
c906108c SS |
4546 | @end table |
4547 | ||
c906108c | 4548 | |
6d2ebf8b | 4549 | @node Source |
c906108c SS |
4550 | @chapter Examining Source Files |
4551 | ||
4552 | @value{GDBN} can print parts of your program's source, since the debugging | |
4553 | information recorded in the program tells @value{GDBN} what source files were | |
4554 | used to build it. When your program stops, @value{GDBN} spontaneously prints | |
4555 | the line where it stopped. Likewise, when you select a stack frame | |
4556 | (@pxref{Selection, ,Selecting a frame}), @value{GDBN} prints the line where | |
4557 | execution in that frame has stopped. You can print other portions of | |
4558 | source files by explicit command. | |
4559 | ||
7a292a7a | 4560 | If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may |
d4f3574e | 4561 | prefer to use Emacs facilities to view source; see @ref{Emacs, ,Using |
7a292a7a | 4562 | @value{GDBN} under @sc{gnu} Emacs}. |
c906108c SS |
4563 | |
4564 | @menu | |
4565 | * List:: Printing source lines | |
87885426 | 4566 | * Edit:: Editing source files |
c906108c | 4567 | * Search:: Searching source files |
c906108c SS |
4568 | * Source Path:: Specifying source directories |
4569 | * Machine Code:: Source and machine code | |
4570 | @end menu | |
4571 | ||
6d2ebf8b | 4572 | @node List |
c906108c SS |
4573 | @section Printing source lines |
4574 | ||
4575 | @kindex list | |
41afff9a | 4576 | @kindex l @r{(@code{list})} |
c906108c | 4577 | To print lines from a source file, use the @code{list} command |
5d161b24 | 4578 | (abbreviated @code{l}). By default, ten lines are printed. |
c906108c SS |
4579 | There are several ways to specify what part of the file you want to print. |
4580 | ||
4581 | Here are the forms of the @code{list} command most commonly used: | |
4582 | ||
4583 | @table @code | |
4584 | @item list @var{linenum} | |
4585 | Print lines centered around line number @var{linenum} in the | |
4586 | current source file. | |
4587 | ||
4588 | @item list @var{function} | |
4589 | Print lines centered around the beginning of function | |
4590 | @var{function}. | |
4591 | ||
4592 | @item list | |
4593 | Print more lines. If the last lines printed were printed with a | |
4594 | @code{list} command, this prints lines following the last lines | |
4595 | printed; however, if the last line printed was a solitary line printed | |
4596 | as part of displaying a stack frame (@pxref{Stack, ,Examining the | |
4597 | Stack}), this prints lines centered around that line. | |
4598 | ||
4599 | @item list - | |
4600 | Print lines just before the lines last printed. | |
4601 | @end table | |
4602 | ||
9c16f35a | 4603 | @cindex @code{list}, how many lines to display |
c906108c SS |
4604 | By default, @value{GDBN} prints ten source lines with any of these forms of |
4605 | the @code{list} command. You can change this using @code{set listsize}: | |
4606 | ||
4607 | @table @code | |
4608 | @kindex set listsize | |
4609 | @item set listsize @var{count} | |
4610 | Make the @code{list} command display @var{count} source lines (unless | |
4611 | the @code{list} argument explicitly specifies some other number). | |
4612 | ||
4613 | @kindex show listsize | |
4614 | @item show listsize | |
4615 | Display the number of lines that @code{list} prints. | |
4616 | @end table | |
4617 | ||
4618 | Repeating a @code{list} command with @key{RET} discards the argument, | |
4619 | so it is equivalent to typing just @code{list}. This is more useful | |
4620 | than listing the same lines again. An exception is made for an | |
4621 | argument of @samp{-}; that argument is preserved in repetition so that | |
4622 | each repetition moves up in the source file. | |
4623 | ||
4624 | @cindex linespec | |
4625 | In general, the @code{list} command expects you to supply zero, one or two | |
4626 | @dfn{linespecs}. Linespecs specify source lines; there are several ways | |
d4f3574e | 4627 | of writing them, but the effect is always to specify some source line. |
c906108c SS |
4628 | Here is a complete description of the possible arguments for @code{list}: |
4629 | ||
4630 | @table @code | |
4631 | @item list @var{linespec} | |
4632 | Print lines centered around the line specified by @var{linespec}. | |
4633 | ||
4634 | @item list @var{first},@var{last} | |
4635 | Print lines from @var{first} to @var{last}. Both arguments are | |
4636 | linespecs. | |
4637 | ||
4638 | @item list ,@var{last} | |
4639 | Print lines ending with @var{last}. | |
4640 | ||
4641 | @item list @var{first}, | |
4642 | Print lines starting with @var{first}. | |
4643 | ||
4644 | @item list + | |
4645 | Print lines just after the lines last printed. | |
4646 | ||
4647 | @item list - | |
4648 | Print lines just before the lines last printed. | |
4649 | ||
4650 | @item list | |
4651 | As described in the preceding table. | |
4652 | @end table | |
4653 | ||
4654 | Here are the ways of specifying a single source line---all the | |
4655 | kinds of linespec. | |
4656 | ||
4657 | @table @code | |
4658 | @item @var{number} | |
4659 | Specifies line @var{number} of the current source file. | |
4660 | When a @code{list} command has two linespecs, this refers to | |
4661 | the same source file as the first linespec. | |
4662 | ||
4663 | @item +@var{offset} | |
4664 | Specifies the line @var{offset} lines after the last line printed. | |
4665 | When used as the second linespec in a @code{list} command that has | |
4666 | two, this specifies the line @var{offset} lines down from the | |
4667 | first linespec. | |
4668 | ||
4669 | @item -@var{offset} | |
4670 | Specifies the line @var{offset} lines before the last line printed. | |
4671 | ||
4672 | @item @var{filename}:@var{number} | |
4673 | Specifies line @var{number} in the source file @var{filename}. | |
4674 | ||
4675 | @item @var{function} | |
4676 | Specifies the line that begins the body of the function @var{function}. | |
4677 | For example: in C, this is the line with the open brace. | |
4678 | ||
4679 | @item @var{filename}:@var{function} | |
4680 | Specifies the line of the open-brace that begins the body of the | |
4681 | function @var{function} in the file @var{filename}. You only need the | |
4682 | file name with a function name to avoid ambiguity when there are | |
4683 | identically named functions in different source files. | |
4684 | ||
4685 | @item *@var{address} | |
4686 | Specifies the line containing the program address @var{address}. | |
4687 | @var{address} may be any expression. | |
4688 | @end table | |
4689 | ||
87885426 FN |
4690 | @node Edit |
4691 | @section Editing source files | |
4692 | @cindex editing source files | |
4693 | ||
4694 | @kindex edit | |
4695 | @kindex e @r{(@code{edit})} | |
4696 | To edit the lines in a source file, use the @code{edit} command. | |
4697 | The editing program of your choice | |
4698 | is invoked with the current line set to | |
4699 | the active line in the program. | |
4700 | Alternatively, there are several ways to specify what part of the file you | |
4701 | want to print if you want to see other parts of the program. | |
4702 | ||
4703 | Here are the forms of the @code{edit} command most commonly used: | |
4704 | ||
4705 | @table @code | |
4706 | @item edit | |
4707 | Edit the current source file at the active line number in the program. | |
4708 | ||
4709 | @item edit @var{number} | |
4710 | Edit the current source file with @var{number} as the active line number. | |
4711 | ||
4712 | @item edit @var{function} | |
4713 | Edit the file containing @var{function} at the beginning of its definition. | |
4714 | ||
4715 | @item edit @var{filename}:@var{number} | |
4716 | Specifies line @var{number} in the source file @var{filename}. | |
4717 | ||
4718 | @item edit @var{filename}:@var{function} | |
4719 | Specifies the line that begins the body of the | |
4720 | function @var{function} in the file @var{filename}. You only need the | |
4721 | file name with a function name to avoid ambiguity when there are | |
4722 | identically named functions in different source files. | |
4723 | ||
4724 | @item edit *@var{address} | |
4725 | Specifies the line containing the program address @var{address}. | |
4726 | @var{address} may be any expression. | |
4727 | @end table | |
4728 | ||
4729 | @subsection Choosing your editor | |
4730 | You can customize @value{GDBN} to use any editor you want | |
4731 | @footnote{ | |
4732 | The only restriction is that your editor (say @code{ex}), recognizes the | |
4733 | following command-line syntax: | |
10998722 | 4734 | @smallexample |
87885426 | 4735 | ex +@var{number} file |
10998722 | 4736 | @end smallexample |
15387254 EZ |
4737 | The optional numeric value +@var{number} specifies the number of the line in |
4738 | the file where to start editing.}. | |
4739 | By default, it is @file{@value{EDITOR}}, but you can change this | |
10998722 AC |
4740 | by setting the environment variable @code{EDITOR} before using |
4741 | @value{GDBN}. For example, to configure @value{GDBN} to use the | |
4742 | @code{vi} editor, you could use these commands with the @code{sh} shell: | |
4743 | @smallexample | |
87885426 FN |
4744 | EDITOR=/usr/bin/vi |
4745 | export EDITOR | |
15387254 | 4746 | gdb @dots{} |
10998722 | 4747 | @end smallexample |
87885426 | 4748 | or in the @code{csh} shell, |
10998722 | 4749 | @smallexample |
87885426 | 4750 | setenv EDITOR /usr/bin/vi |
15387254 | 4751 | gdb @dots{} |
10998722 | 4752 | @end smallexample |
87885426 | 4753 | |
6d2ebf8b | 4754 | @node Search |
c906108c | 4755 | @section Searching source files |
15387254 | 4756 | @cindex searching source files |
c906108c SS |
4757 | |
4758 | There are two commands for searching through the current source file for a | |
4759 | regular expression. | |
4760 | ||
4761 | @table @code | |
4762 | @kindex search | |
4763 | @kindex forward-search | |
4764 | @item forward-search @var{regexp} | |
4765 | @itemx search @var{regexp} | |
4766 | The command @samp{forward-search @var{regexp}} checks each line, | |
4767 | starting with the one following the last line listed, for a match for | |
5d161b24 | 4768 | @var{regexp}. It lists the line that is found. You can use the |
c906108c SS |
4769 | synonym @samp{search @var{regexp}} or abbreviate the command name as |
4770 | @code{fo}. | |
4771 | ||
09d4efe1 | 4772 | @kindex reverse-search |
c906108c SS |
4773 | @item reverse-search @var{regexp} |
4774 | The command @samp{reverse-search @var{regexp}} checks each line, starting | |
4775 | with the one before the last line listed and going backward, for a match | |
4776 | for @var{regexp}. It lists the line that is found. You can abbreviate | |
4777 | this command as @code{rev}. | |
4778 | @end table | |
c906108c | 4779 | |
6d2ebf8b | 4780 | @node Source Path |
c906108c SS |
4781 | @section Specifying source directories |
4782 | ||
4783 | @cindex source path | |
4784 | @cindex directories for source files | |
4785 | Executable programs sometimes do not record the directories of the source | |
4786 | files from which they were compiled, just the names. Even when they do, | |
4787 | the directories could be moved between the compilation and your debugging | |
4788 | session. @value{GDBN} has a list of directories to search for source files; | |
4789 | this is called the @dfn{source path}. Each time @value{GDBN} wants a source file, | |
4790 | it tries all the directories in the list, in the order they are present | |
0b66e38c EZ |
4791 | in the list, until it finds a file with the desired name. |
4792 | ||
4793 | For example, suppose an executable references the file | |
4794 | @file{/usr/src/foo-1.0/lib/foo.c}, and our source path is | |
4795 | @file{/mnt/cross}. The file is first looked up literally; if this | |
4796 | fails, @file{/mnt/cross/usr/src/foo-1.0/lib/foo.c} is tried; if this | |
4797 | fails, @file{/mnt/cross/foo.c} is opened; if this fails, an error | |
4798 | message is printed. @value{GDBN} does not look up the parts of the | |
4799 | source file name, such as @file{/mnt/cross/src/foo-1.0/lib/foo.c}. | |
4800 | Likewise, the subdirectories of the source path are not searched: if | |
4801 | the source path is @file{/mnt/cross}, and the binary refers to | |
4802 | @file{foo.c}, @value{GDBN} would not find it under | |
4803 | @file{/mnt/cross/usr/src/foo-1.0/lib}. | |
4804 | ||
4805 | Plain file names, relative file names with leading directories, file | |
4806 | names containing dots, etc.@: are all treated as described above; for | |
4807 | instance, if the source path is @file{/mnt/cross}, and the source file | |
4808 | is recorded as @file{../lib/foo.c}, @value{GDBN} would first try | |
4809 | @file{../lib/foo.c}, then @file{/mnt/cross/../lib/foo.c}, and after | |
4810 | that---@file{/mnt/cross/foo.c}. | |
4811 | ||
4812 | Note that the executable search path is @emph{not} used to locate the | |
4813 | source files. Neither is the current working directory, unless it | |
4814 | happens to be in the source path. | |
c906108c SS |
4815 | |
4816 | Whenever you reset or rearrange the source path, @value{GDBN} clears out | |
4817 | any information it has cached about where source files are found and where | |
4818 | each line is in the file. | |
4819 | ||
4820 | @kindex directory | |
4821 | @kindex dir | |
d4f3574e SS |
4822 | When you start @value{GDBN}, its source path includes only @samp{cdir} |
4823 | and @samp{cwd}, in that order. | |
c906108c SS |
4824 | To add other directories, use the @code{directory} command. |
4825 | ||
4826 | @table @code | |
4827 | @item directory @var{dirname} @dots{} | |
4828 | @item dir @var{dirname} @dots{} | |
4829 | Add directory @var{dirname} to the front of the source path. Several | |
d4f3574e SS |
4830 | directory names may be given to this command, separated by @samp{:} |
4831 | (@samp{;} on MS-DOS and MS-Windows, where @samp{:} usually appears as | |
4832 | part of absolute file names) or | |
c906108c SS |
4833 | whitespace. You may specify a directory that is already in the source |
4834 | path; this moves it forward, so @value{GDBN} searches it sooner. | |
4835 | ||
4836 | @kindex cdir | |
4837 | @kindex cwd | |
41afff9a EZ |
4838 | @vindex $cdir@r{, convenience variable} |
4839 | @vindex $cwdr@r{, convenience variable} | |
c906108c SS |
4840 | @cindex compilation directory |
4841 | @cindex current directory | |
4842 | @cindex working directory | |
4843 | @cindex directory, current | |
4844 | @cindex directory, compilation | |
4845 | You can use the string @samp{$cdir} to refer to the compilation | |
4846 | directory (if one is recorded), and @samp{$cwd} to refer to the current | |
4847 | working directory. @samp{$cwd} is not the same as @samp{.}---the former | |
4848 | tracks the current working directory as it changes during your @value{GDBN} | |
4849 | session, while the latter is immediately expanded to the current | |
4850 | directory at the time you add an entry to the source path. | |
4851 | ||
4852 | @item directory | |
4853 | Reset the source path to empty again. This requires confirmation. | |
4854 | ||
4855 | @c RET-repeat for @code{directory} is explicitly disabled, but since | |
4856 | @c repeating it would be a no-op we do not say that. (thanks to RMS) | |
4857 | ||
4858 | @item show directories | |
4859 | @kindex show directories | |
4860 | Print the source path: show which directories it contains. | |
4861 | @end table | |
4862 | ||
4863 | If your source path is cluttered with directories that are no longer of | |
4864 | interest, @value{GDBN} may sometimes cause confusion by finding the wrong | |
4865 | versions of source. You can correct the situation as follows: | |
4866 | ||
4867 | @enumerate | |
4868 | @item | |
4869 | Use @code{directory} with no argument to reset the source path to empty. | |
4870 | ||
4871 | @item | |
4872 | Use @code{directory} with suitable arguments to reinstall the | |
4873 | directories you want in the source path. You can add all the | |
4874 | directories in one command. | |
4875 | @end enumerate | |
4876 | ||
6d2ebf8b | 4877 | @node Machine Code |
c906108c | 4878 | @section Source and machine code |
15387254 | 4879 | @cindex source line and its code address |
c906108c SS |
4880 | |
4881 | You can use the command @code{info line} to map source lines to program | |
4882 | addresses (and vice versa), and the command @code{disassemble} to display | |
4883 | a range of addresses as machine instructions. When run under @sc{gnu} Emacs | |
d4f3574e | 4884 | mode, the @code{info line} command causes the arrow to point to the |
5d161b24 | 4885 | line specified. Also, @code{info line} prints addresses in symbolic form as |
c906108c SS |
4886 | well as hex. |
4887 | ||
4888 | @table @code | |
4889 | @kindex info line | |
4890 | @item info line @var{linespec} | |
4891 | Print the starting and ending addresses of the compiled code for | |
4892 | source line @var{linespec}. You can specify source lines in any of | |
4893 | the ways understood by the @code{list} command (@pxref{List, ,Printing | |
4894 | source lines}). | |
4895 | @end table | |
4896 | ||
4897 | For example, we can use @code{info line} to discover the location of | |
4898 | the object code for the first line of function | |
4899 | @code{m4_changequote}: | |
4900 | ||
d4f3574e SS |
4901 | @c FIXME: I think this example should also show the addresses in |
4902 | @c symbolic form, as they usually would be displayed. | |
c906108c | 4903 | @smallexample |
96a2c332 | 4904 | (@value{GDBP}) info line m4_changequote |
c906108c SS |
4905 | Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350. |
4906 | @end smallexample | |
4907 | ||
4908 | @noindent | |
15387254 | 4909 | @cindex code address and its source line |
c906108c SS |
4910 | We can also inquire (using @code{*@var{addr}} as the form for |
4911 | @var{linespec}) what source line covers a particular address: | |
4912 | @smallexample | |
4913 | (@value{GDBP}) info line *0x63ff | |
4914 | Line 926 of "builtin.c" starts at pc 0x63e4 and ends at 0x6404. | |
4915 | @end smallexample | |
4916 | ||
4917 | @cindex @code{$_} and @code{info line} | |
15387254 | 4918 | @cindex @code{x} command, default address |
41afff9a | 4919 | @kindex x@r{(examine), and} info line |
c906108c SS |
4920 | After @code{info line}, the default address for the @code{x} command |
4921 | is changed to the starting address of the line, so that @samp{x/i} is | |
4922 | sufficient to begin examining the machine code (@pxref{Memory, | |
4923 | ,Examining memory}). Also, this address is saved as the value of the | |
4924 | convenience variable @code{$_} (@pxref{Convenience Vars, ,Convenience | |
4925 | variables}). | |
4926 | ||
4927 | @table @code | |
4928 | @kindex disassemble | |
4929 | @cindex assembly instructions | |
4930 | @cindex instructions, assembly | |
4931 | @cindex machine instructions | |
4932 | @cindex listing machine instructions | |
4933 | @item disassemble | |
4934 | This specialized command dumps a range of memory as machine | |
4935 | instructions. The default memory range is the function surrounding the | |
4936 | program counter of the selected frame. A single argument to this | |
4937 | command is a program counter value; @value{GDBN} dumps the function | |
4938 | surrounding this value. Two arguments specify a range of addresses | |
4939 | (first inclusive, second exclusive) to dump. | |
4940 | @end table | |
4941 | ||
c906108c SS |
4942 | The following example shows the disassembly of a range of addresses of |
4943 | HP PA-RISC 2.0 code: | |
4944 | ||
4945 | @smallexample | |
4946 | (@value{GDBP}) disas 0x32c4 0x32e4 | |
4947 | Dump of assembler code from 0x32c4 to 0x32e4: | |
4948 | 0x32c4 <main+204>: addil 0,dp | |
4949 | 0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26 | |
4950 | 0x32cc <main+212>: ldil 0x3000,r31 | |
4951 | 0x32d0 <main+216>: ble 0x3f8(sr4,r31) | |
4952 | 0x32d4 <main+220>: ldo 0(r31),rp | |
4953 | 0x32d8 <main+224>: addil -0x800,dp | |
4954 | 0x32dc <main+228>: ldo 0x588(r1),r26 | |
4955 | 0x32e0 <main+232>: ldil 0x3000,r31 | |
4956 | End of assembler dump. | |
4957 | @end smallexample | |
c906108c SS |
4958 | |
4959 | Some architectures have more than one commonly-used set of instruction | |
4960 | mnemonics or other syntax. | |
4961 | ||
76d17f34 EZ |
4962 | For programs that were dynamically linked and use shared libraries, |
4963 | instructions that call functions or branch to locations in the shared | |
4964 | libraries might show a seemingly bogus location---it's actually a | |
4965 | location of the relocation table. On some architectures, @value{GDBN} | |
4966 | might be able to resolve these to actual function names. | |
4967 | ||
c906108c | 4968 | @table @code |
d4f3574e | 4969 | @kindex set disassembly-flavor |
d4f3574e SS |
4970 | @cindex Intel disassembly flavor |
4971 | @cindex AT&T disassembly flavor | |
4972 | @item set disassembly-flavor @var{instruction-set} | |
c906108c SS |
4973 | Select the instruction set to use when disassembling the |
4974 | program via the @code{disassemble} or @code{x/i} commands. | |
4975 | ||
4976 | Currently this command is only defined for the Intel x86 family. You | |
d4f3574e SS |
4977 | can set @var{instruction-set} to either @code{intel} or @code{att}. |
4978 | The default is @code{att}, the AT&T flavor used by default by Unix | |
4979 | assemblers for x86-based targets. | |
9c16f35a EZ |
4980 | |
4981 | @kindex show disassembly-flavor | |
4982 | @item show disassembly-flavor | |
4983 | Show the current setting of the disassembly flavor. | |
c906108c SS |
4984 | @end table |
4985 | ||
4986 | ||
6d2ebf8b | 4987 | @node Data |
c906108c SS |
4988 | @chapter Examining Data |
4989 | ||
4990 | @cindex printing data | |
4991 | @cindex examining data | |
4992 | @kindex print | |
4993 | @kindex inspect | |
4994 | @c "inspect" is not quite a synonym if you are using Epoch, which we do not | |
4995 | @c document because it is nonstandard... Under Epoch it displays in a | |
4996 | @c different window or something like that. | |
4997 | The usual way to examine data in your program is with the @code{print} | |
7a292a7a SS |
4998 | command (abbreviated @code{p}), or its synonym @code{inspect}. It |
4999 | evaluates and prints the value of an expression of the language your | |
5000 | program is written in (@pxref{Languages, ,Using @value{GDBN} with | |
5001 | Different Languages}). | |
c906108c SS |
5002 | |
5003 | @table @code | |
d4f3574e SS |
5004 | @item print @var{expr} |
5005 | @itemx print /@var{f} @var{expr} | |
5006 | @var{expr} is an expression (in the source language). By default the | |
5007 | value of @var{expr} is printed in a format appropriate to its data type; | |
c906108c | 5008 | you can choose a different format by specifying @samp{/@var{f}}, where |
d4f3574e | 5009 | @var{f} is a letter specifying the format; see @ref{Output Formats,,Output |
c906108c SS |
5010 | formats}. |
5011 | ||
5012 | @item print | |
5013 | @itemx print /@var{f} | |
15387254 | 5014 | @cindex reprint the last value |
d4f3574e | 5015 | If you omit @var{expr}, @value{GDBN} displays the last value again (from the |
c906108c SS |
5016 | @dfn{value history}; @pxref{Value History, ,Value history}). This allows you to |
5017 | conveniently inspect the same value in an alternative format. | |
5018 | @end table | |
5019 | ||
5020 | A more low-level way of examining data is with the @code{x} command. | |
5021 | It examines data in memory at a specified address and prints it in a | |
5022 | specified format. @xref{Memory, ,Examining memory}. | |
5023 | ||
7a292a7a | 5024 | If you are interested in information about types, or about how the |
d4f3574e SS |
5025 | fields of a struct or a class are declared, use the @code{ptype @var{exp}} |
5026 | command rather than @code{print}. @xref{Symbols, ,Examining the Symbol | |
7a292a7a | 5027 | Table}. |
c906108c SS |
5028 | |
5029 | @menu | |
5030 | * Expressions:: Expressions | |
5031 | * Variables:: Program variables | |
5032 | * Arrays:: Artificial arrays | |
5033 | * Output Formats:: Output formats | |
5034 | * Memory:: Examining memory | |
5035 | * Auto Display:: Automatic display | |
5036 | * Print Settings:: Print settings | |
5037 | * Value History:: Value history | |
5038 | * Convenience Vars:: Convenience variables | |
5039 | * Registers:: Registers | |
c906108c | 5040 | * Floating Point Hardware:: Floating point hardware |
53c69bd7 | 5041 | * Vector Unit:: Vector Unit |
721c2651 | 5042 | * OS Information:: Auxiliary data provided by operating system |
29e57380 | 5043 | * Memory Region Attributes:: Memory region attributes |
16d9dec6 | 5044 | * Dump/Restore Files:: Copy between memory and a file |
384ee23f | 5045 | * Core File Generation:: Cause a program dump its core |
a0eb71c5 KB |
5046 | * Character Sets:: Debugging programs that use a different |
5047 | character set than GDB does | |
09d4efe1 | 5048 | * Caching Remote Data:: Data caching for remote targets |
c906108c SS |
5049 | @end menu |
5050 | ||
6d2ebf8b | 5051 | @node Expressions |
c906108c SS |
5052 | @section Expressions |
5053 | ||
5054 | @cindex expressions | |
5055 | @code{print} and many other @value{GDBN} commands accept an expression and | |
5056 | compute its value. Any kind of constant, variable or operator defined | |
5057 | by the programming language you are using is valid in an expression in | |
e2e0bcd1 JB |
5058 | @value{GDBN}. This includes conditional expressions, function calls, |
5059 | casts, and string constants. It also includes preprocessor macros, if | |
5060 | you compiled your program to include this information; see | |
5061 | @ref{Compilation}. | |
c906108c | 5062 | |
15387254 | 5063 | @cindex arrays in expressions |
d4f3574e SS |
5064 | @value{GDBN} supports array constants in expressions input by |
5065 | the user. The syntax is @{@var{element}, @var{element}@dots{}@}. For example, | |
5d161b24 | 5066 | you can use the command @code{print @{1, 2, 3@}} to build up an array in |
d4f3574e | 5067 | memory that is @code{malloc}ed in the target program. |
c906108c | 5068 | |
c906108c SS |
5069 | Because C is so widespread, most of the expressions shown in examples in |
5070 | this manual are in C. @xref{Languages, , Using @value{GDBN} with Different | |
5071 | Languages}, for information on how to use expressions in other | |
5072 | languages. | |
5073 | ||
5074 | In this section, we discuss operators that you can use in @value{GDBN} | |
5075 | expressions regardless of your programming language. | |
5076 | ||
15387254 | 5077 | @cindex casts, in expressions |
c906108c SS |
5078 | Casts are supported in all languages, not just in C, because it is so |
5079 | useful to cast a number into a pointer in order to examine a structure | |
5080 | at that address in memory. | |
5081 | @c FIXME: casts supported---Mod2 true? | |
c906108c SS |
5082 | |
5083 | @value{GDBN} supports these operators, in addition to those common | |
5084 | to programming languages: | |
5085 | ||
5086 | @table @code | |
5087 | @item @@ | |
5088 | @samp{@@} is a binary operator for treating parts of memory as arrays. | |
5089 | @xref{Arrays, ,Artificial arrays}, for more information. | |
5090 | ||
5091 | @item :: | |
5092 | @samp{::} allows you to specify a variable in terms of the file or | |
5093 | function where it is defined. @xref{Variables, ,Program variables}. | |
5094 | ||
5095 | @cindex @{@var{type}@} | |
5096 | @cindex type casting memory | |
5097 | @cindex memory, viewing as typed object | |
5098 | @cindex casts, to view memory | |
5099 | @item @{@var{type}@} @var{addr} | |
5100 | Refers to an object of type @var{type} stored at address @var{addr} in | |
5101 | memory. @var{addr} may be any expression whose value is an integer or | |
5102 | pointer (but parentheses are required around binary operators, just as in | |
5103 | a cast). This construct is allowed regardless of what kind of data is | |
5104 | normally supposed to reside at @var{addr}. | |
5105 | @end table | |
5106 | ||
6d2ebf8b | 5107 | @node Variables |
c906108c SS |
5108 | @section Program variables |
5109 | ||
5110 | The most common kind of expression to use is the name of a variable | |
5111 | in your program. | |
5112 | ||
5113 | Variables in expressions are understood in the selected stack frame | |
5114 | (@pxref{Selection, ,Selecting a frame}); they must be either: | |
5115 | ||
5116 | @itemize @bullet | |
5117 | @item | |
5118 | global (or file-static) | |
5119 | @end itemize | |
5120 | ||
5d161b24 | 5121 | @noindent or |
c906108c SS |
5122 | |
5123 | @itemize @bullet | |
5124 | @item | |
5125 | visible according to the scope rules of the | |
5126 | programming language from the point of execution in that frame | |
5d161b24 | 5127 | @end itemize |
c906108c SS |
5128 | |
5129 | @noindent This means that in the function | |
5130 | ||
474c8240 | 5131 | @smallexample |
c906108c SS |
5132 | foo (a) |
5133 | int a; | |
5134 | @{ | |
5135 | bar (a); | |
5136 | @{ | |
5137 | int b = test (); | |
5138 | bar (b); | |
5139 | @} | |
5140 | @} | |
474c8240 | 5141 | @end smallexample |
c906108c SS |
5142 | |
5143 | @noindent | |
5144 | you can examine and use the variable @code{a} whenever your program is | |
5145 | executing within the function @code{foo}, but you can only use or | |
5146 | examine the variable @code{b} while your program is executing inside | |
5147 | the block where @code{b} is declared. | |
5148 | ||
5149 | @cindex variable name conflict | |
5150 | There is an exception: you can refer to a variable or function whose | |
5151 | scope is a single source file even if the current execution point is not | |
5152 | in this file. But it is possible to have more than one such variable or | |
5153 | function with the same name (in different source files). If that | |
5154 | happens, referring to that name has unpredictable effects. If you wish, | |
5155 | you can specify a static variable in a particular function or file, | |
15387254 | 5156 | using the colon-colon (@code{::}) notation: |
c906108c | 5157 | |
d4f3574e | 5158 | @cindex colon-colon, context for variables/functions |
c906108c SS |
5159 | @iftex |
5160 | @c info cannot cope with a :: index entry, but why deprive hard copy readers? | |
41afff9a | 5161 | @cindex @code{::}, context for variables/functions |
c906108c | 5162 | @end iftex |
474c8240 | 5163 | @smallexample |
c906108c SS |
5164 | @var{file}::@var{variable} |
5165 | @var{function}::@var{variable} | |
474c8240 | 5166 | @end smallexample |
c906108c SS |
5167 | |
5168 | @noindent | |
5169 | Here @var{file} or @var{function} is the name of the context for the | |
5170 | static @var{variable}. In the case of file names, you can use quotes to | |
5171 | make sure @value{GDBN} parses the file name as a single word---for example, | |
5172 | to print a global value of @code{x} defined in @file{f2.c}: | |
5173 | ||
474c8240 | 5174 | @smallexample |
c906108c | 5175 | (@value{GDBP}) p 'f2.c'::x |
474c8240 | 5176 | @end smallexample |
c906108c | 5177 | |
b37052ae | 5178 | @cindex C@t{++} scope resolution |
c906108c | 5179 | This use of @samp{::} is very rarely in conflict with the very similar |
b37052ae | 5180 | use of the same notation in C@t{++}. @value{GDBN} also supports use of the C@t{++} |
c906108c SS |
5181 | scope resolution operator in @value{GDBN} expressions. |
5182 | @c FIXME: Um, so what happens in one of those rare cases where it's in | |
5183 | @c conflict?? --mew | |
c906108c SS |
5184 | |
5185 | @cindex wrong values | |
5186 | @cindex variable values, wrong | |
15387254 EZ |
5187 | @cindex function entry/exit, wrong values of variables |
5188 | @cindex optimized code, wrong values of variables | |
c906108c SS |
5189 | @quotation |
5190 | @emph{Warning:} Occasionally, a local variable may appear to have the | |
5191 | wrong value at certain points in a function---just after entry to a new | |
5192 | scope, and just before exit. | |
5193 | @end quotation | |
5194 | You may see this problem when you are stepping by machine instructions. | |
5195 | This is because, on most machines, it takes more than one instruction to | |
5196 | set up a stack frame (including local variable definitions); if you are | |
5197 | stepping by machine instructions, variables may appear to have the wrong | |
5198 | values until the stack frame is completely built. On exit, it usually | |
5199 | also takes more than one machine instruction to destroy a stack frame; | |
5200 | after you begin stepping through that group of instructions, local | |
5201 | variable definitions may be gone. | |
5202 | ||
5203 | This may also happen when the compiler does significant optimizations. | |
5204 | To be sure of always seeing accurate values, turn off all optimization | |
5205 | when compiling. | |
5206 | ||
d4f3574e SS |
5207 | @cindex ``No symbol "foo" in current context'' |
5208 | Another possible effect of compiler optimizations is to optimize | |
5209 | unused variables out of existence, or assign variables to registers (as | |
5210 | opposed to memory addresses). Depending on the support for such cases | |
5211 | offered by the debug info format used by the compiler, @value{GDBN} | |
5212 | might not be able to display values for such local variables. If that | |
5213 | happens, @value{GDBN} will print a message like this: | |
5214 | ||
474c8240 | 5215 | @smallexample |
d4f3574e | 5216 | No symbol "foo" in current context. |
474c8240 | 5217 | @end smallexample |
d4f3574e SS |
5218 | |
5219 | To solve such problems, either recompile without optimizations, or use a | |
5220 | different debug info format, if the compiler supports several such | |
15387254 | 5221 | formats. For example, @value{NGCC}, the @sc{gnu} C/C@t{++} compiler, |
0179ffac DC |
5222 | usually supports the @option{-gstabs+} option. @option{-gstabs+} |
5223 | produces debug info in a format that is superior to formats such as | |
5224 | COFF. You may be able to use DWARF 2 (@option{-gdwarf-2}), which is also | |
5225 | an effective form for debug info. @xref{Debugging Options,,Options | |
5226 | for Debugging Your Program or @sc{gnu} CC, gcc.info, Using @sc{gnu} CC}. | |
15387254 EZ |
5227 | @xref{C, , Debugging C++}, for more info about debug info formats |
5228 | that are best suited to C@t{++} programs. | |
d4f3574e | 5229 | |
ab1adacd EZ |
5230 | If you ask to print an object whose contents are unknown to |
5231 | @value{GDBN}, e.g., because its data type is not completely specified | |
5232 | by the debug information, @value{GDBN} will say @samp{<incomplete | |
5233 | type>}. @xref{Symbols, incomplete type}, for more about this. | |
5234 | ||
6d2ebf8b | 5235 | @node Arrays |
c906108c SS |
5236 | @section Artificial arrays |
5237 | ||
5238 | @cindex artificial array | |
15387254 | 5239 | @cindex arrays |
41afff9a | 5240 | @kindex @@@r{, referencing memory as an array} |
c906108c SS |
5241 | It is often useful to print out several successive objects of the |
5242 | same type in memory; a section of an array, or an array of | |
5243 | dynamically determined size for which only a pointer exists in the | |
5244 | program. | |
5245 | ||
5246 | You can do this by referring to a contiguous span of memory as an | |
5247 | @dfn{artificial array}, using the binary operator @samp{@@}. The left | |
5248 | operand of @samp{@@} should be the first element of the desired array | |
5249 | and be an individual object. The right operand should be the desired length | |
5250 | of the array. The result is an array value whose elements are all of | |
5251 | the type of the left argument. The first element is actually the left | |
5252 | argument; the second element comes from bytes of memory immediately | |
5253 | following those that hold the first element, and so on. Here is an | |
5254 | example. If a program says | |
5255 | ||
474c8240 | 5256 | @smallexample |
c906108c | 5257 | int *array = (int *) malloc (len * sizeof (int)); |
474c8240 | 5258 | @end smallexample |
c906108c SS |
5259 | |
5260 | @noindent | |
5261 | you can print the contents of @code{array} with | |
5262 | ||
474c8240 | 5263 | @smallexample |
c906108c | 5264 | p *array@@len |
474c8240 | 5265 | @end smallexample |
c906108c SS |
5266 | |
5267 | The left operand of @samp{@@} must reside in memory. Array values made | |
5268 | with @samp{@@} in this way behave just like other arrays in terms of | |
5269 | subscripting, and are coerced to pointers when used in expressions. | |
5270 | Artificial arrays most often appear in expressions via the value history | |
5271 | (@pxref{Value History, ,Value history}), after printing one out. | |
5272 | ||
5273 | Another way to create an artificial array is to use a cast. | |
5274 | This re-interprets a value as if it were an array. | |
5275 | The value need not be in memory: | |
474c8240 | 5276 | @smallexample |
c906108c SS |
5277 | (@value{GDBP}) p/x (short[2])0x12345678 |
5278 | $1 = @{0x1234, 0x5678@} | |
474c8240 | 5279 | @end smallexample |
c906108c SS |
5280 | |
5281 | As a convenience, if you leave the array length out (as in | |
c3f6f71d | 5282 | @samp{(@var{type}[])@var{value}}) @value{GDBN} calculates the size to fill |
c906108c | 5283 | the value (as @samp{sizeof(@var{value})/sizeof(@var{type})}: |
474c8240 | 5284 | @smallexample |
c906108c SS |
5285 | (@value{GDBP}) p/x (short[])0x12345678 |
5286 | $2 = @{0x1234, 0x5678@} | |
474c8240 | 5287 | @end smallexample |
c906108c SS |
5288 | |
5289 | Sometimes the artificial array mechanism is not quite enough; in | |
5290 | moderately complex data structures, the elements of interest may not | |
5291 | actually be adjacent---for example, if you are interested in the values | |
5292 | of pointers in an array. One useful work-around in this situation is | |
5293 | to use a convenience variable (@pxref{Convenience Vars, ,Convenience | |
5294 | variables}) as a counter in an expression that prints the first | |
5295 | interesting value, and then repeat that expression via @key{RET}. For | |
5296 | instance, suppose you have an array @code{dtab} of pointers to | |
5297 | structures, and you are interested in the values of a field @code{fv} | |
5298 | in each structure. Here is an example of what you might type: | |
5299 | ||
474c8240 | 5300 | @smallexample |
c906108c SS |
5301 | set $i = 0 |
5302 | p dtab[$i++]->fv | |
5303 | @key{RET} | |
5304 | @key{RET} | |
5305 | @dots{} | |
474c8240 | 5306 | @end smallexample |
c906108c | 5307 | |
6d2ebf8b | 5308 | @node Output Formats |
c906108c SS |
5309 | @section Output formats |
5310 | ||
5311 | @cindex formatted output | |
5312 | @cindex output formats | |
5313 | By default, @value{GDBN} prints a value according to its data type. Sometimes | |
5314 | this is not what you want. For example, you might want to print a number | |
5315 | in hex, or a pointer in decimal. Or you might want to view data in memory | |
5316 | at a certain address as a character string or as an instruction. To do | |
5317 | these things, specify an @dfn{output format} when you print a value. | |
5318 | ||
5319 | The simplest use of output formats is to say how to print a value | |
5320 | already computed. This is done by starting the arguments of the | |
5321 | @code{print} command with a slash and a format letter. The format | |
5322 | letters supported are: | |
5323 | ||
5324 | @table @code | |
5325 | @item x | |
5326 | Regard the bits of the value as an integer, and print the integer in | |
5327 | hexadecimal. | |
5328 | ||
5329 | @item d | |
5330 | Print as integer in signed decimal. | |
5331 | ||
5332 | @item u | |
5333 | Print as integer in unsigned decimal. | |
5334 | ||
5335 | @item o | |
5336 | Print as integer in octal. | |
5337 | ||
5338 | @item t | |
5339 | Print as integer in binary. The letter @samp{t} stands for ``two''. | |
5340 | @footnote{@samp{b} cannot be used because these format letters are also | |
5341 | used with the @code{x} command, where @samp{b} stands for ``byte''; | |
d4f3574e | 5342 | see @ref{Memory,,Examining memory}.} |
c906108c SS |
5343 | |
5344 | @item a | |
5345 | @cindex unknown address, locating | |
3d67e040 | 5346 | @cindex locate address |
c906108c SS |
5347 | Print as an address, both absolute in hexadecimal and as an offset from |
5348 | the nearest preceding symbol. You can use this format used to discover | |
5349 | where (in what function) an unknown address is located: | |
5350 | ||
474c8240 | 5351 | @smallexample |
c906108c SS |
5352 | (@value{GDBP}) p/a 0x54320 |
5353 | $3 = 0x54320 <_initialize_vx+396> | |
474c8240 | 5354 | @end smallexample |
c906108c | 5355 | |
3d67e040 EZ |
5356 | @noindent |
5357 | The command @code{info symbol 0x54320} yields similar results. | |
5358 | @xref{Symbols, info symbol}. | |
5359 | ||
c906108c | 5360 | @item c |
51274035 EZ |
5361 | Regard as an integer and print it as a character constant. This |
5362 | prints both the numerical value and its character representation. The | |
5363 | character representation is replaced with the octal escape @samp{\nnn} | |
5364 | for characters outside the 7-bit @sc{ascii} range. | |
c906108c SS |
5365 | |
5366 | @item f | |
5367 | Regard the bits of the value as a floating point number and print | |
5368 | using typical floating point syntax. | |
5369 | @end table | |
5370 | ||
5371 | For example, to print the program counter in hex (@pxref{Registers}), type | |
5372 | ||
474c8240 | 5373 | @smallexample |
c906108c | 5374 | p/x $pc |
474c8240 | 5375 | @end smallexample |
c906108c SS |
5376 | |
5377 | @noindent | |
5378 | Note that no space is required before the slash; this is because command | |
5379 | names in @value{GDBN} cannot contain a slash. | |
5380 | ||
5381 | To reprint the last value in the value history with a different format, | |
5382 | you can use the @code{print} command with just a format and no | |
5383 | expression. For example, @samp{p/x} reprints the last value in hex. | |
5384 | ||
6d2ebf8b | 5385 | @node Memory |
c906108c SS |
5386 | @section Examining memory |
5387 | ||
5388 | You can use the command @code{x} (for ``examine'') to examine memory in | |
5389 | any of several formats, independently of your program's data types. | |
5390 | ||
5391 | @cindex examining memory | |
5392 | @table @code | |
41afff9a | 5393 | @kindex x @r{(examine memory)} |
c906108c SS |
5394 | @item x/@var{nfu} @var{addr} |
5395 | @itemx x @var{addr} | |
5396 | @itemx x | |
5397 | Use the @code{x} command to examine memory. | |
5398 | @end table | |
5399 | ||
5400 | @var{n}, @var{f}, and @var{u} are all optional parameters that specify how | |
5401 | much memory to display and how to format it; @var{addr} is an | |
5402 | expression giving the address where you want to start displaying memory. | |
5403 | If you use defaults for @var{nfu}, you need not type the slash @samp{/}. | |
5404 | Several commands set convenient defaults for @var{addr}. | |
5405 | ||
5406 | @table @r | |
5407 | @item @var{n}, the repeat count | |
5408 | The repeat count is a decimal integer; the default is 1. It specifies | |
5409 | how much memory (counting by units @var{u}) to display. | |
5410 | @c This really is **decimal**; unaffected by 'set radix' as of GDB | |
5411 | @c 4.1.2. | |
5412 | ||
5413 | @item @var{f}, the display format | |
51274035 EZ |
5414 | The display format is one of the formats used by @code{print} |
5415 | (@samp{x}, @samp{d}, @samp{u}, @samp{o}, @samp{t}, @samp{a}, @samp{c}, | |
5416 | @samp{f}), and in addition @samp{s} (for null-terminated strings) and | |
5417 | @samp{i} (for machine instructions). The default is @samp{x} | |
5418 | (hexadecimal) initially. The default changes each time you use either | |
5419 | @code{x} or @code{print}. | |
c906108c SS |
5420 | |
5421 | @item @var{u}, the unit size | |
5422 | The unit size is any of | |
5423 | ||
5424 | @table @code | |
5425 | @item b | |
5426 | Bytes. | |
5427 | @item h | |
5428 | Halfwords (two bytes). | |
5429 | @item w | |
5430 | Words (four bytes). This is the initial default. | |
5431 | @item g | |
5432 | Giant words (eight bytes). | |
5433 | @end table | |
5434 | ||
5435 | Each time you specify a unit size with @code{x}, that size becomes the | |
5436 | default unit the next time you use @code{x}. (For the @samp{s} and | |
5437 | @samp{i} formats, the unit size is ignored and is normally not written.) | |
5438 | ||
5439 | @item @var{addr}, starting display address | |
5440 | @var{addr} is the address where you want @value{GDBN} to begin displaying | |
5441 | memory. The expression need not have a pointer value (though it may); | |
5442 | it is always interpreted as an integer address of a byte of memory. | |
5443 | @xref{Expressions, ,Expressions}, for more information on expressions. The default for | |
5444 | @var{addr} is usually just after the last address examined---but several | |
5445 | other commands also set the default address: @code{info breakpoints} (to | |
5446 | the address of the last breakpoint listed), @code{info line} (to the | |
5447 | starting address of a line), and @code{print} (if you use it to display | |
5448 | a value from memory). | |
5449 | @end table | |
5450 | ||
5451 | For example, @samp{x/3uh 0x54320} is a request to display three halfwords | |
5452 | (@code{h}) of memory, formatted as unsigned decimal integers (@samp{u}), | |
5453 | starting at address @code{0x54320}. @samp{x/4xw $sp} prints the four | |
5454 | words (@samp{w}) of memory above the stack pointer (here, @samp{$sp}; | |
d4f3574e | 5455 | @pxref{Registers, ,Registers}) in hexadecimal (@samp{x}). |
c906108c SS |
5456 | |
5457 | Since the letters indicating unit sizes are all distinct from the | |
5458 | letters specifying output formats, you do not have to remember whether | |
5459 | unit size or format comes first; either order works. The output | |
5460 | specifications @samp{4xw} and @samp{4wx} mean exactly the same thing. | |
5461 | (However, the count @var{n} must come first; @samp{wx4} does not work.) | |
5462 | ||
5463 | Even though the unit size @var{u} is ignored for the formats @samp{s} | |
5464 | and @samp{i}, you might still want to use a count @var{n}; for example, | |
5465 | @samp{3i} specifies that you want to see three machine instructions, | |
5466 | including any operands. The command @code{disassemble} gives an | |
d4f3574e | 5467 | alternative way of inspecting machine instructions; see @ref{Machine |
c906108c SS |
5468 | Code,,Source and machine code}. |
5469 | ||
5470 | All the defaults for the arguments to @code{x} are designed to make it | |
5471 | easy to continue scanning memory with minimal specifications each time | |
5472 | you use @code{x}. For example, after you have inspected three machine | |
5473 | instructions with @samp{x/3i @var{addr}}, you can inspect the next seven | |
5474 | with just @samp{x/7}. If you use @key{RET} to repeat the @code{x} command, | |
5475 | the repeat count @var{n} is used again; the other arguments default as | |
5476 | for successive uses of @code{x}. | |
5477 | ||
5478 | @cindex @code{$_}, @code{$__}, and value history | |
5479 | The addresses and contents printed by the @code{x} command are not saved | |
5480 | in the value history because there is often too much of them and they | |
5481 | would get in the way. Instead, @value{GDBN} makes these values available for | |
5482 | subsequent use in expressions as values of the convenience variables | |
5483 | @code{$_} and @code{$__}. After an @code{x} command, the last address | |
5484 | examined is available for use in expressions in the convenience variable | |
5485 | @code{$_}. The contents of that address, as examined, are available in | |
5486 | the convenience variable @code{$__}. | |
5487 | ||
5488 | If the @code{x} command has a repeat count, the address and contents saved | |
5489 | are from the last memory unit printed; this is not the same as the last | |
5490 | address printed if several units were printed on the last line of output. | |
5491 | ||
09d4efe1 EZ |
5492 | @cindex remote memory comparison |
5493 | @cindex verify remote memory image | |
5494 | When you are debugging a program running on a remote target machine | |
5495 | (@pxref{Remote}), you may wish to verify the program's image in the | |
5496 | remote machine's memory against the executable file you downloaded to | |
5497 | the target. The @code{compare-sections} command is provided for such | |
5498 | situations. | |
5499 | ||
5500 | @table @code | |
5501 | @kindex compare-sections | |
5502 | @item compare-sections @r{[}@var{section-name}@r{]} | |
5503 | Compare the data of a loadable section @var{section-name} in the | |
5504 | executable file of the program being debugged with the same section in | |
5505 | the remote machine's memory, and report any mismatches. With no | |
5506 | arguments, compares all loadable sections. This command's | |
5507 | availability depends on the target's support for the @code{"qCRC"} | |
5508 | remote request. | |
5509 | @end table | |
5510 | ||
6d2ebf8b | 5511 | @node Auto Display |
c906108c SS |
5512 | @section Automatic display |
5513 | @cindex automatic display | |
5514 | @cindex display of expressions | |
5515 | ||
5516 | If you find that you want to print the value of an expression frequently | |
5517 | (to see how it changes), you might want to add it to the @dfn{automatic | |
5518 | display list} so that @value{GDBN} prints its value each time your program stops. | |
5519 | Each expression added to the list is given a number to identify it; | |
5520 | to remove an expression from the list, you specify that number. | |
5521 | The automatic display looks like this: | |
5522 | ||
474c8240 | 5523 | @smallexample |
c906108c SS |
5524 | 2: foo = 38 |
5525 | 3: bar[5] = (struct hack *) 0x3804 | |
474c8240 | 5526 | @end smallexample |
c906108c SS |
5527 | |
5528 | @noindent | |
5529 | This display shows item numbers, expressions and their current values. As with | |
5530 | displays you request manually using @code{x} or @code{print}, you can | |
5531 | specify the output format you prefer; in fact, @code{display} decides | |
5532 | whether to use @code{print} or @code{x} depending on how elaborate your | |
5533 | format specification is---it uses @code{x} if you specify a unit size, | |
5534 | or one of the two formats (@samp{i} and @samp{s}) that are only | |
5535 | supported by @code{x}; otherwise it uses @code{print}. | |
5536 | ||
5537 | @table @code | |
5538 | @kindex display | |
d4f3574e SS |
5539 | @item display @var{expr} |
5540 | Add the expression @var{expr} to the list of expressions to display | |
c906108c SS |
5541 | each time your program stops. @xref{Expressions, ,Expressions}. |
5542 | ||
5543 | @code{display} does not repeat if you press @key{RET} again after using it. | |
5544 | ||
d4f3574e | 5545 | @item display/@var{fmt} @var{expr} |
c906108c | 5546 | For @var{fmt} specifying only a display format and not a size or |
d4f3574e | 5547 | count, add the expression @var{expr} to the auto-display list but |
c906108c SS |
5548 | arrange to display it each time in the specified format @var{fmt}. |
5549 | @xref{Output Formats,,Output formats}. | |
5550 | ||
5551 | @item display/@var{fmt} @var{addr} | |
5552 | For @var{fmt} @samp{i} or @samp{s}, or including a unit-size or a | |
5553 | number of units, add the expression @var{addr} as a memory address to | |
5554 | be examined each time your program stops. Examining means in effect | |
5555 | doing @samp{x/@var{fmt} @var{addr}}. @xref{Memory, ,Examining memory}. | |
5556 | @end table | |
5557 | ||
5558 | For example, @samp{display/i $pc} can be helpful, to see the machine | |
5559 | instruction about to be executed each time execution stops (@samp{$pc} | |
d4f3574e | 5560 | is a common name for the program counter; @pxref{Registers, ,Registers}). |
c906108c SS |
5561 | |
5562 | @table @code | |
5563 | @kindex delete display | |
5564 | @kindex undisplay | |
5565 | @item undisplay @var{dnums}@dots{} | |
5566 | @itemx delete display @var{dnums}@dots{} | |
5567 | Remove item numbers @var{dnums} from the list of expressions to display. | |
5568 | ||
5569 | @code{undisplay} does not repeat if you press @key{RET} after using it. | |
5570 | (Otherwise you would just get the error @samp{No display number @dots{}}.) | |
5571 | ||
5572 | @kindex disable display | |
5573 | @item disable display @var{dnums}@dots{} | |
5574 | Disable the display of item numbers @var{dnums}. A disabled display | |
5575 | item is not printed automatically, but is not forgotten. It may be | |
5576 | enabled again later. | |
5577 | ||
5578 | @kindex enable display | |
5579 | @item enable display @var{dnums}@dots{} | |
5580 | Enable display of item numbers @var{dnums}. It becomes effective once | |
5581 | again in auto display of its expression, until you specify otherwise. | |
5582 | ||
5583 | @item display | |
5584 | Display the current values of the expressions on the list, just as is | |
5585 | done when your program stops. | |
5586 | ||
5587 | @kindex info display | |
5588 | @item info display | |
5589 | Print the list of expressions previously set up to display | |
5590 | automatically, each one with its item number, but without showing the | |
5591 | values. This includes disabled expressions, which are marked as such. | |
5592 | It also includes expressions which would not be displayed right now | |
5593 | because they refer to automatic variables not currently available. | |
5594 | @end table | |
5595 | ||
15387254 | 5596 | @cindex display disabled out of scope |
c906108c SS |
5597 | If a display expression refers to local variables, then it does not make |
5598 | sense outside the lexical context for which it was set up. Such an | |
5599 | expression is disabled when execution enters a context where one of its | |
5600 | variables is not defined. For example, if you give the command | |
5601 | @code{display last_char} while inside a function with an argument | |
5602 | @code{last_char}, @value{GDBN} displays this argument while your program | |
5603 | continues to stop inside that function. When it stops elsewhere---where | |
5604 | there is no variable @code{last_char}---the display is disabled | |
5605 | automatically. The next time your program stops where @code{last_char} | |
5606 | is meaningful, you can enable the display expression once again. | |
5607 | ||
6d2ebf8b | 5608 | @node Print Settings |
c906108c SS |
5609 | @section Print settings |
5610 | ||
5611 | @cindex format options | |
5612 | @cindex print settings | |
5613 | @value{GDBN} provides the following ways to control how arrays, structures, | |
5614 | and symbols are printed. | |
5615 | ||
5616 | @noindent | |
5617 | These settings are useful for debugging programs in any language: | |
5618 | ||
5619 | @table @code | |
4644b6e3 | 5620 | @kindex set print |
c906108c SS |
5621 | @item set print address |
5622 | @itemx set print address on | |
4644b6e3 | 5623 | @cindex print/don't print memory addresses |
c906108c SS |
5624 | @value{GDBN} prints memory addresses showing the location of stack |
5625 | traces, structure values, pointer values, breakpoints, and so forth, | |
5626 | even when it also displays the contents of those addresses. The default | |
5627 | is @code{on}. For example, this is what a stack frame display looks like with | |
5628 | @code{set print address on}: | |
5629 | ||
5630 | @smallexample | |
5631 | @group | |
5632 | (@value{GDBP}) f | |
5633 | #0 set_quotes (lq=0x34c78 "<<", rq=0x34c88 ">>") | |
5634 | at input.c:530 | |
5635 | 530 if (lquote != def_lquote) | |
5636 | @end group | |
5637 | @end smallexample | |
5638 | ||
5639 | @item set print address off | |
5640 | Do not print addresses when displaying their contents. For example, | |
5641 | this is the same stack frame displayed with @code{set print address off}: | |
5642 | ||
5643 | @smallexample | |
5644 | @group | |
5645 | (@value{GDBP}) set print addr off | |
5646 | (@value{GDBP}) f | |
5647 | #0 set_quotes (lq="<<", rq=">>") at input.c:530 | |
5648 | 530 if (lquote != def_lquote) | |
5649 | @end group | |
5650 | @end smallexample | |
5651 | ||
5652 | You can use @samp{set print address off} to eliminate all machine | |
5653 | dependent displays from the @value{GDBN} interface. For example, with | |
5654 | @code{print address off}, you should get the same text for backtraces on | |
5655 | all machines---whether or not they involve pointer arguments. | |
5656 | ||
4644b6e3 | 5657 | @kindex show print |
c906108c SS |
5658 | @item show print address |
5659 | Show whether or not addresses are to be printed. | |
5660 | @end table | |
5661 | ||
5662 | When @value{GDBN} prints a symbolic address, it normally prints the | |
5663 | closest earlier symbol plus an offset. If that symbol does not uniquely | |
5664 | identify the address (for example, it is a name whose scope is a single | |
5665 | source file), you may need to clarify. One way to do this is with | |
5666 | @code{info line}, for example @samp{info line *0x4537}. Alternately, | |
5667 | you can set @value{GDBN} to print the source file and line number when | |
5668 | it prints a symbolic address: | |
5669 | ||
5670 | @table @code | |
c906108c | 5671 | @item set print symbol-filename on |
9c16f35a EZ |
5672 | @cindex source file and line of a symbol |
5673 | @cindex symbol, source file and line | |
c906108c SS |
5674 | Tell @value{GDBN} to print the source file name and line number of a |
5675 | symbol in the symbolic form of an address. | |
5676 | ||
5677 | @item set print symbol-filename off | |
5678 | Do not print source file name and line number of a symbol. This is the | |
5679 | default. | |
5680 | ||
c906108c SS |
5681 | @item show print symbol-filename |
5682 | Show whether or not @value{GDBN} will print the source file name and | |
5683 | line number of a symbol in the symbolic form of an address. | |
5684 | @end table | |
5685 | ||
5686 | Another situation where it is helpful to show symbol filenames and line | |
5687 | numbers is when disassembling code; @value{GDBN} shows you the line | |
5688 | number and source file that corresponds to each instruction. | |
5689 | ||
5690 | Also, you may wish to see the symbolic form only if the address being | |
5691 | printed is reasonably close to the closest earlier symbol: | |
5692 | ||
5693 | @table @code | |
c906108c | 5694 | @item set print max-symbolic-offset @var{max-offset} |
4644b6e3 | 5695 | @cindex maximum value for offset of closest symbol |
c906108c SS |
5696 | Tell @value{GDBN} to only display the symbolic form of an address if the |
5697 | offset between the closest earlier symbol and the address is less than | |
5d161b24 | 5698 | @var{max-offset}. The default is 0, which tells @value{GDBN} |
c906108c SS |
5699 | to always print the symbolic form of an address if any symbol precedes it. |
5700 | ||
c906108c SS |
5701 | @item show print max-symbolic-offset |
5702 | Ask how large the maximum offset is that @value{GDBN} prints in a | |
5703 | symbolic address. | |
5704 | @end table | |
5705 | ||
5706 | @cindex wild pointer, interpreting | |
5707 | @cindex pointer, finding referent | |
5708 | If you have a pointer and you are not sure where it points, try | |
5709 | @samp{set print symbol-filename on}. Then you can determine the name | |
5710 | and source file location of the variable where it points, using | |
5711 | @samp{p/a @var{pointer}}. This interprets the address in symbolic form. | |
5712 | For example, here @value{GDBN} shows that a variable @code{ptt} points | |
5713 | at another variable @code{t}, defined in @file{hi2.c}: | |
5714 | ||
474c8240 | 5715 | @smallexample |
c906108c SS |
5716 | (@value{GDBP}) set print symbol-filename on |
5717 | (@value{GDBP}) p/a ptt | |
5718 | $4 = 0xe008 <t in hi2.c> | |
474c8240 | 5719 | @end smallexample |
c906108c SS |
5720 | |
5721 | @quotation | |
5722 | @emph{Warning:} For pointers that point to a local variable, @samp{p/a} | |
5723 | does not show the symbol name and filename of the referent, even with | |
5724 | the appropriate @code{set print} options turned on. | |
5725 | @end quotation | |
5726 | ||
5727 | Other settings control how different kinds of objects are printed: | |
5728 | ||
5729 | @table @code | |
c906108c SS |
5730 | @item set print array |
5731 | @itemx set print array on | |
4644b6e3 | 5732 | @cindex pretty print arrays |
c906108c SS |
5733 | Pretty print arrays. This format is more convenient to read, |
5734 | but uses more space. The default is off. | |
5735 | ||
5736 | @item set print array off | |
5737 | Return to compressed format for arrays. | |
5738 | ||
c906108c SS |
5739 | @item show print array |
5740 | Show whether compressed or pretty format is selected for displaying | |
5741 | arrays. | |
5742 | ||
3c9c013a JB |
5743 | @cindex print array indexes |
5744 | @item set print array-indexes | |
5745 | @itemx set print array-indexes on | |
5746 | Print the index of each element when displaying arrays. May be more | |
5747 | convenient to locate a given element in the array or quickly find the | |
5748 | index of a given element in that printed array. The default is off. | |
5749 | ||
5750 | @item set print array-indexes off | |
5751 | Stop printing element indexes when displaying arrays. | |
5752 | ||
5753 | @item show print array-indexes | |
5754 | Show whether the index of each element is printed when displaying | |
5755 | arrays. | |
5756 | ||
c906108c | 5757 | @item set print elements @var{number-of-elements} |
4644b6e3 | 5758 | @cindex number of array elements to print |
9c16f35a | 5759 | @cindex limit on number of printed array elements |
c906108c SS |
5760 | Set a limit on how many elements of an array @value{GDBN} will print. |
5761 | If @value{GDBN} is printing a large array, it stops printing after it has | |
5762 | printed the number of elements set by the @code{set print elements} command. | |
5763 | This limit also applies to the display of strings. | |
d4f3574e | 5764 | When @value{GDBN} starts, this limit is set to 200. |
c906108c SS |
5765 | Setting @var{number-of-elements} to zero means that the printing is unlimited. |
5766 | ||
c906108c SS |
5767 | @item show print elements |
5768 | Display the number of elements of a large array that @value{GDBN} will print. | |
5769 | If the number is 0, then the printing is unlimited. | |
5770 | ||
9c16f35a EZ |
5771 | @item set print repeats |
5772 | @cindex repeated array elements | |
5773 | Set the threshold for suppressing display of repeated array | |
5774 | elelments. When the number of consecutive identical elements of an | |
5775 | array exceeds the threshold, @value{GDBN} prints the string | |
5776 | @code{"<repeats @var{n} times>"}, where @var{n} is the number of | |
5777 | identical repetitions, instead of displaying the identical elements | |
5778 | themselves. Setting the threshold to zero will cause all elements to | |
5779 | be individually printed. The default threshold is 10. | |
5780 | ||
5781 | @item show print repeats | |
5782 | Display the current threshold for printing repeated identical | |
5783 | elements. | |
5784 | ||
c906108c | 5785 | @item set print null-stop |
4644b6e3 | 5786 | @cindex @sc{null} elements in arrays |
c906108c | 5787 | Cause @value{GDBN} to stop printing the characters of an array when the first |
d4f3574e | 5788 | @sc{null} is encountered. This is useful when large arrays actually |
c906108c | 5789 | contain only short strings. |
d4f3574e | 5790 | The default is off. |
c906108c | 5791 | |
9c16f35a EZ |
5792 | @item show print null-stop |
5793 | Show whether @value{GDBN} stops printing an array on the first | |
5794 | @sc{null} character. | |
5795 | ||
c906108c | 5796 | @item set print pretty on |
9c16f35a EZ |
5797 | @cindex print structures in indented form |
5798 | @cindex indentation in structure display | |
5d161b24 | 5799 | Cause @value{GDBN} to print structures in an indented format with one member |
c906108c SS |
5800 | per line, like this: |
5801 | ||
5802 | @smallexample | |
5803 | @group | |
5804 | $1 = @{ | |
5805 | next = 0x0, | |
5806 | flags = @{ | |
5807 | sweet = 1, | |
5808 | sour = 1 | |
5809 | @}, | |
5810 | meat = 0x54 "Pork" | |
5811 | @} | |
5812 | @end group | |
5813 | @end smallexample | |
5814 | ||
5815 | @item set print pretty off | |
5816 | Cause @value{GDBN} to print structures in a compact format, like this: | |
5817 | ||
5818 | @smallexample | |
5819 | @group | |
5820 | $1 = @{next = 0x0, flags = @{sweet = 1, sour = 1@}, \ | |
5821 | meat = 0x54 "Pork"@} | |
5822 | @end group | |
5823 | @end smallexample | |
5824 | ||
5825 | @noindent | |
5826 | This is the default format. | |
5827 | ||
c906108c SS |
5828 | @item show print pretty |
5829 | Show which format @value{GDBN} is using to print structures. | |
5830 | ||
c906108c | 5831 | @item set print sevenbit-strings on |
4644b6e3 EZ |
5832 | @cindex eight-bit characters in strings |
5833 | @cindex octal escapes in strings | |
c906108c SS |
5834 | Print using only seven-bit characters; if this option is set, |
5835 | @value{GDBN} displays any eight-bit characters (in strings or | |
5836 | character values) using the notation @code{\}@var{nnn}. This setting is | |
5837 | best if you are working in English (@sc{ascii}) and you use the | |
5838 | high-order bit of characters as a marker or ``meta'' bit. | |
5839 | ||
5840 | @item set print sevenbit-strings off | |
5841 | Print full eight-bit characters. This allows the use of more | |
5842 | international character sets, and is the default. | |
5843 | ||
c906108c SS |
5844 | @item show print sevenbit-strings |
5845 | Show whether or not @value{GDBN} is printing only seven-bit characters. | |
5846 | ||
c906108c | 5847 | @item set print union on |
4644b6e3 | 5848 | @cindex unions in structures, printing |
9c16f35a EZ |
5849 | Tell @value{GDBN} to print unions which are contained in structures |
5850 | and other unions. This is the default setting. | |
c906108c SS |
5851 | |
5852 | @item set print union off | |
9c16f35a EZ |
5853 | Tell @value{GDBN} not to print unions which are contained in |
5854 | structures and other unions. @value{GDBN} will print @code{"@{...@}"} | |
5855 | instead. | |
c906108c | 5856 | |
c906108c SS |
5857 | @item show print union |
5858 | Ask @value{GDBN} whether or not it will print unions which are contained in | |
9c16f35a | 5859 | structures and other unions. |
c906108c SS |
5860 | |
5861 | For example, given the declarations | |
5862 | ||
5863 | @smallexample | |
5864 | typedef enum @{Tree, Bug@} Species; | |
5865 | typedef enum @{Big_tree, Acorn, Seedling@} Tree_forms; | |
5d161b24 | 5866 | typedef enum @{Caterpillar, Cocoon, Butterfly@} |
c906108c SS |
5867 | Bug_forms; |
5868 | ||
5869 | struct thing @{ | |
5870 | Species it; | |
5871 | union @{ | |
5872 | Tree_forms tree; | |
5873 | Bug_forms bug; | |
5874 | @} form; | |
5875 | @}; | |
5876 | ||
5877 | struct thing foo = @{Tree, @{Acorn@}@}; | |
5878 | @end smallexample | |
5879 | ||
5880 | @noindent | |
5881 | with @code{set print union on} in effect @samp{p foo} would print | |
5882 | ||
5883 | @smallexample | |
5884 | $1 = @{it = Tree, form = @{tree = Acorn, bug = Cocoon@}@} | |
5885 | @end smallexample | |
5886 | ||
5887 | @noindent | |
5888 | and with @code{set print union off} in effect it would print | |
5889 | ||
5890 | @smallexample | |
5891 | $1 = @{it = Tree, form = @{...@}@} | |
5892 | @end smallexample | |
9c16f35a EZ |
5893 | |
5894 | @noindent | |
5895 | @code{set print union} affects programs written in C-like languages | |
5896 | and in Pascal. | |
c906108c SS |
5897 | @end table |
5898 | ||
c906108c SS |
5899 | @need 1000 |
5900 | @noindent | |
b37052ae | 5901 | These settings are of interest when debugging C@t{++} programs: |
c906108c SS |
5902 | |
5903 | @table @code | |
4644b6e3 | 5904 | @cindex demangling C@t{++} names |
c906108c SS |
5905 | @item set print demangle |
5906 | @itemx set print demangle on | |
b37052ae | 5907 | Print C@t{++} names in their source form rather than in the encoded |
c906108c | 5908 | (``mangled'') form passed to the assembler and linker for type-safe |
d4f3574e | 5909 | linkage. The default is on. |
c906108c | 5910 | |
c906108c | 5911 | @item show print demangle |
b37052ae | 5912 | Show whether C@t{++} names are printed in mangled or demangled form. |
c906108c | 5913 | |
c906108c SS |
5914 | @item set print asm-demangle |
5915 | @itemx set print asm-demangle on | |
b37052ae | 5916 | Print C@t{++} names in their source form rather than their mangled form, even |
c906108c SS |
5917 | in assembler code printouts such as instruction disassemblies. |
5918 | The default is off. | |
5919 | ||
c906108c | 5920 | @item show print asm-demangle |
b37052ae | 5921 | Show whether C@t{++} names in assembly listings are printed in mangled |
c906108c SS |
5922 | or demangled form. |
5923 | ||
b37052ae EZ |
5924 | @cindex C@t{++} symbol decoding style |
5925 | @cindex symbol decoding style, C@t{++} | |
a8f24a35 | 5926 | @kindex set demangle-style |
c906108c SS |
5927 | @item set demangle-style @var{style} |
5928 | Choose among several encoding schemes used by different compilers to | |
b37052ae | 5929 | represent C@t{++} names. The choices for @var{style} are currently: |
c906108c SS |
5930 | |
5931 | @table @code | |
5932 | @item auto | |
5933 | Allow @value{GDBN} to choose a decoding style by inspecting your program. | |
5934 | ||
5935 | @item gnu | |
b37052ae | 5936 | Decode based on the @sc{gnu} C@t{++} compiler (@code{g++}) encoding algorithm. |
c906108c | 5937 | This is the default. |
c906108c SS |
5938 | |
5939 | @item hp | |
b37052ae | 5940 | Decode based on the HP ANSI C@t{++} (@code{aCC}) encoding algorithm. |
c906108c SS |
5941 | |
5942 | @item lucid | |
b37052ae | 5943 | Decode based on the Lucid C@t{++} compiler (@code{lcc}) encoding algorithm. |
c906108c SS |
5944 | |
5945 | @item arm | |
b37052ae | 5946 | Decode using the algorithm in the @cite{C@t{++} Annotated Reference Manual}. |
c906108c SS |
5947 | @strong{Warning:} this setting alone is not sufficient to allow |
5948 | debugging @code{cfront}-generated executables. @value{GDBN} would | |
5949 | require further enhancement to permit that. | |
5950 | ||
5951 | @end table | |
5952 | If you omit @var{style}, you will see a list of possible formats. | |
5953 | ||
c906108c | 5954 | @item show demangle-style |
b37052ae | 5955 | Display the encoding style currently in use for decoding C@t{++} symbols. |
c906108c | 5956 | |
c906108c SS |
5957 | @item set print object |
5958 | @itemx set print object on | |
4644b6e3 | 5959 | @cindex derived type of an object, printing |
9c16f35a | 5960 | @cindex display derived types |
c906108c SS |
5961 | When displaying a pointer to an object, identify the @emph{actual} |
5962 | (derived) type of the object rather than the @emph{declared} type, using | |
5963 | the virtual function table. | |
5964 | ||
5965 | @item set print object off | |
5966 | Display only the declared type of objects, without reference to the | |
5967 | virtual function table. This is the default setting. | |
5968 | ||
c906108c SS |
5969 | @item show print object |
5970 | Show whether actual, or declared, object types are displayed. | |
5971 | ||
c906108c SS |
5972 | @item set print static-members |
5973 | @itemx set print static-members on | |
4644b6e3 | 5974 | @cindex static members of C@t{++} objects |
b37052ae | 5975 | Print static members when displaying a C@t{++} object. The default is on. |
c906108c SS |
5976 | |
5977 | @item set print static-members off | |
b37052ae | 5978 | Do not print static members when displaying a C@t{++} object. |
c906108c | 5979 | |
c906108c | 5980 | @item show print static-members |
9c16f35a EZ |
5981 | Show whether C@t{++} static members are printed or not. |
5982 | ||
5983 | @item set print pascal_static-members | |
5984 | @itemx set print pascal_static-members on | |
5985 | @cindex static members of Pacal objects | |
5986 | @cindex Pacal objects, static members display | |
5987 | Print static members when displaying a Pascal object. The default is on. | |
5988 | ||
5989 | @item set print pascal_static-members off | |
5990 | Do not print static members when displaying a Pascal object. | |
5991 | ||
5992 | @item show print pascal_static-members | |
5993 | Show whether Pascal static members are printed or not. | |
c906108c SS |
5994 | |
5995 | @c These don't work with HP ANSI C++ yet. | |
c906108c SS |
5996 | @item set print vtbl |
5997 | @itemx set print vtbl on | |
4644b6e3 | 5998 | @cindex pretty print C@t{++} virtual function tables |
9c16f35a EZ |
5999 | @cindex virtual functions (C@t{++}) display |
6000 | @cindex VTBL display | |
b37052ae | 6001 | Pretty print C@t{++} virtual function tables. The default is off. |
c906108c | 6002 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 6003 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
6004 | |
6005 | @item set print vtbl off | |
b37052ae | 6006 | Do not pretty print C@t{++} virtual function tables. |
c906108c | 6007 | |
c906108c | 6008 | @item show print vtbl |
b37052ae | 6009 | Show whether C@t{++} virtual function tables are pretty printed, or not. |
c906108c | 6010 | @end table |
c906108c | 6011 | |
6d2ebf8b | 6012 | @node Value History |
c906108c SS |
6013 | @section Value history |
6014 | ||
6015 | @cindex value history | |
9c16f35a | 6016 | @cindex history of values printed by @value{GDBN} |
5d161b24 DB |
6017 | Values printed by the @code{print} command are saved in the @value{GDBN} |
6018 | @dfn{value history}. This allows you to refer to them in other expressions. | |
6019 | Values are kept until the symbol table is re-read or discarded | |
6020 | (for example with the @code{file} or @code{symbol-file} commands). | |
6021 | When the symbol table changes, the value history is discarded, | |
6022 | since the values may contain pointers back to the types defined in the | |
c906108c SS |
6023 | symbol table. |
6024 | ||
6025 | @cindex @code{$} | |
6026 | @cindex @code{$$} | |
6027 | @cindex history number | |
6028 | The values printed are given @dfn{history numbers} by which you can | |
6029 | refer to them. These are successive integers starting with one. | |
6030 | @code{print} shows you the history number assigned to a value by | |
6031 | printing @samp{$@var{num} = } before the value; here @var{num} is the | |
6032 | history number. | |
6033 | ||
6034 | To refer to any previous value, use @samp{$} followed by the value's | |
6035 | history number. The way @code{print} labels its output is designed to | |
6036 | remind you of this. Just @code{$} refers to the most recent value in | |
6037 | the history, and @code{$$} refers to the value before that. | |
6038 | @code{$$@var{n}} refers to the @var{n}th value from the end; @code{$$2} | |
6039 | is the value just prior to @code{$$}, @code{$$1} is equivalent to | |
6040 | @code{$$}, and @code{$$0} is equivalent to @code{$}. | |
6041 | ||
6042 | For example, suppose you have just printed a pointer to a structure and | |
6043 | want to see the contents of the structure. It suffices to type | |
6044 | ||
474c8240 | 6045 | @smallexample |
c906108c | 6046 | p *$ |
474c8240 | 6047 | @end smallexample |
c906108c SS |
6048 | |
6049 | If you have a chain of structures where the component @code{next} points | |
6050 | to the next one, you can print the contents of the next one with this: | |
6051 | ||
474c8240 | 6052 | @smallexample |
c906108c | 6053 | p *$.next |
474c8240 | 6054 | @end smallexample |
c906108c SS |
6055 | |
6056 | @noindent | |
6057 | You can print successive links in the chain by repeating this | |
6058 | command---which you can do by just typing @key{RET}. | |
6059 | ||
6060 | Note that the history records values, not expressions. If the value of | |
6061 | @code{x} is 4 and you type these commands: | |
6062 | ||
474c8240 | 6063 | @smallexample |
c906108c SS |
6064 | print x |
6065 | set x=5 | |
474c8240 | 6066 | @end smallexample |
c906108c SS |
6067 | |
6068 | @noindent | |
6069 | then the value recorded in the value history by the @code{print} command | |
6070 | remains 4 even though the value of @code{x} has changed. | |
6071 | ||
6072 | @table @code | |
6073 | @kindex show values | |
6074 | @item show values | |
6075 | Print the last ten values in the value history, with their item numbers. | |
6076 | This is like @samp{p@ $$9} repeated ten times, except that @code{show | |
6077 | values} does not change the history. | |
6078 | ||
6079 | @item show values @var{n} | |
6080 | Print ten history values centered on history item number @var{n}. | |
6081 | ||
6082 | @item show values + | |
6083 | Print ten history values just after the values last printed. If no more | |
6084 | values are available, @code{show values +} produces no display. | |
6085 | @end table | |
6086 | ||
6087 | Pressing @key{RET} to repeat @code{show values @var{n}} has exactly the | |
6088 | same effect as @samp{show values +}. | |
6089 | ||
6d2ebf8b | 6090 | @node Convenience Vars |
c906108c SS |
6091 | @section Convenience variables |
6092 | ||
6093 | @cindex convenience variables | |
9c16f35a | 6094 | @cindex user-defined variables |
c906108c SS |
6095 | @value{GDBN} provides @dfn{convenience variables} that you can use within |
6096 | @value{GDBN} to hold on to a value and refer to it later. These variables | |
6097 | exist entirely within @value{GDBN}; they are not part of your program, and | |
6098 | setting a convenience variable has no direct effect on further execution | |
6099 | of your program. That is why you can use them freely. | |
6100 | ||
6101 | Convenience variables are prefixed with @samp{$}. Any name preceded by | |
6102 | @samp{$} can be used for a convenience variable, unless it is one of | |
d4f3574e | 6103 | the predefined machine-specific register names (@pxref{Registers, ,Registers}). |
c906108c SS |
6104 | (Value history references, in contrast, are @emph{numbers} preceded |
6105 | by @samp{$}. @xref{Value History, ,Value history}.) | |
6106 | ||
6107 | You can save a value in a convenience variable with an assignment | |
6108 | expression, just as you would set a variable in your program. | |
6109 | For example: | |
6110 | ||
474c8240 | 6111 | @smallexample |
c906108c | 6112 | set $foo = *object_ptr |
474c8240 | 6113 | @end smallexample |
c906108c SS |
6114 | |
6115 | @noindent | |
6116 | would save in @code{$foo} the value contained in the object pointed to by | |
6117 | @code{object_ptr}. | |
6118 | ||
6119 | Using a convenience variable for the first time creates it, but its | |
6120 | value is @code{void} until you assign a new value. You can alter the | |
6121 | value with another assignment at any time. | |
6122 | ||
6123 | Convenience variables have no fixed types. You can assign a convenience | |
6124 | variable any type of value, including structures and arrays, even if | |
6125 | that variable already has a value of a different type. The convenience | |
6126 | variable, when used as an expression, has the type of its current value. | |
6127 | ||
6128 | @table @code | |
6129 | @kindex show convenience | |
9c16f35a | 6130 | @cindex show all user variables |
c906108c SS |
6131 | @item show convenience |
6132 | Print a list of convenience variables used so far, and their values. | |
d4f3574e | 6133 | Abbreviated @code{show conv}. |
c906108c SS |
6134 | @end table |
6135 | ||
6136 | One of the ways to use a convenience variable is as a counter to be | |
6137 | incremented or a pointer to be advanced. For example, to print | |
6138 | a field from successive elements of an array of structures: | |
6139 | ||
474c8240 | 6140 | @smallexample |
c906108c SS |
6141 | set $i = 0 |
6142 | print bar[$i++]->contents | |
474c8240 | 6143 | @end smallexample |
c906108c | 6144 | |
d4f3574e SS |
6145 | @noindent |
6146 | Repeat that command by typing @key{RET}. | |
c906108c SS |
6147 | |
6148 | Some convenience variables are created automatically by @value{GDBN} and given | |
6149 | values likely to be useful. | |
6150 | ||
6151 | @table @code | |
41afff9a | 6152 | @vindex $_@r{, convenience variable} |
c906108c SS |
6153 | @item $_ |
6154 | The variable @code{$_} is automatically set by the @code{x} command to | |
6155 | the last address examined (@pxref{Memory, ,Examining memory}). Other | |
6156 | commands which provide a default address for @code{x} to examine also | |
6157 | set @code{$_} to that address; these commands include @code{info line} | |
6158 | and @code{info breakpoint}. The type of @code{$_} is @code{void *} | |
6159 | except when set by the @code{x} command, in which case it is a pointer | |
6160 | to the type of @code{$__}. | |
6161 | ||
41afff9a | 6162 | @vindex $__@r{, convenience variable} |
c906108c SS |
6163 | @item $__ |
6164 | The variable @code{$__} is automatically set by the @code{x} command | |
6165 | to the value found in the last address examined. Its type is chosen | |
6166 | to match the format in which the data was printed. | |
6167 | ||
6168 | @item $_exitcode | |
41afff9a | 6169 | @vindex $_exitcode@r{, convenience variable} |
c906108c SS |
6170 | The variable @code{$_exitcode} is automatically set to the exit code when |
6171 | the program being debugged terminates. | |
6172 | @end table | |
6173 | ||
53a5351d JM |
6174 | On HP-UX systems, if you refer to a function or variable name that |
6175 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
6176 | name first, before it searches for a convenience variable. | |
c906108c | 6177 | |
6d2ebf8b | 6178 | @node Registers |
c906108c SS |
6179 | @section Registers |
6180 | ||
6181 | @cindex registers | |
6182 | You can refer to machine register contents, in expressions, as variables | |
6183 | with names starting with @samp{$}. The names of registers are different | |
6184 | for each machine; use @code{info registers} to see the names used on | |
6185 | your machine. | |
6186 | ||
6187 | @table @code | |
6188 | @kindex info registers | |
6189 | @item info registers | |
6190 | Print the names and values of all registers except floating-point | |
c85508ee | 6191 | and vector registers (in the selected stack frame). |
c906108c SS |
6192 | |
6193 | @kindex info all-registers | |
6194 | @cindex floating point registers | |
6195 | @item info all-registers | |
6196 | Print the names and values of all registers, including floating-point | |
c85508ee | 6197 | and vector registers (in the selected stack frame). |
c906108c SS |
6198 | |
6199 | @item info registers @var{regname} @dots{} | |
6200 | Print the @dfn{relativized} value of each specified register @var{regname}. | |
5d161b24 DB |
6201 | As discussed in detail below, register values are normally relative to |
6202 | the selected stack frame. @var{regname} may be any register name valid on | |
c906108c SS |
6203 | the machine you are using, with or without the initial @samp{$}. |
6204 | @end table | |
6205 | ||
e09f16f9 EZ |
6206 | @cindex stack pointer register |
6207 | @cindex program counter register | |
6208 | @cindex process status register | |
6209 | @cindex frame pointer register | |
6210 | @cindex standard registers | |
c906108c SS |
6211 | @value{GDBN} has four ``standard'' register names that are available (in |
6212 | expressions) on most machines---whenever they do not conflict with an | |
6213 | architecture's canonical mnemonics for registers. The register names | |
6214 | @code{$pc} and @code{$sp} are used for the program counter register and | |
6215 | the stack pointer. @code{$fp} is used for a register that contains a | |
6216 | pointer to the current stack frame, and @code{$ps} is used for a | |
6217 | register that contains the processor status. For example, | |
6218 | you could print the program counter in hex with | |
6219 | ||
474c8240 | 6220 | @smallexample |
c906108c | 6221 | p/x $pc |
474c8240 | 6222 | @end smallexample |
c906108c SS |
6223 | |
6224 | @noindent | |
6225 | or print the instruction to be executed next with | |
6226 | ||
474c8240 | 6227 | @smallexample |
c906108c | 6228 | x/i $pc |
474c8240 | 6229 | @end smallexample |
c906108c SS |
6230 | |
6231 | @noindent | |
6232 | or add four to the stack pointer@footnote{This is a way of removing | |
6233 | one word from the stack, on machines where stacks grow downward in | |
6234 | memory (most machines, nowadays). This assumes that the innermost | |
6235 | stack frame is selected; setting @code{$sp} is not allowed when other | |
6236 | stack frames are selected. To pop entire frames off the stack, | |
6237 | regardless of machine architecture, use @code{return}; | |
d4f3574e | 6238 | see @ref{Returning, ,Returning from a function}.} with |
c906108c | 6239 | |
474c8240 | 6240 | @smallexample |
c906108c | 6241 | set $sp += 4 |
474c8240 | 6242 | @end smallexample |
c906108c SS |
6243 | |
6244 | Whenever possible, these four standard register names are available on | |
6245 | your machine even though the machine has different canonical mnemonics, | |
6246 | so long as there is no conflict. The @code{info registers} command | |
6247 | shows the canonical names. For example, on the SPARC, @code{info | |
6248 | registers} displays the processor status register as @code{$psr} but you | |
d4f3574e SS |
6249 | can also refer to it as @code{$ps}; and on x86-based machines @code{$ps} |
6250 | is an alias for the @sc{eflags} register. | |
c906108c SS |
6251 | |
6252 | @value{GDBN} always considers the contents of an ordinary register as an | |
6253 | integer when the register is examined in this way. Some machines have | |
6254 | special registers which can hold nothing but floating point; these | |
6255 | registers are considered to have floating point values. There is no way | |
6256 | to refer to the contents of an ordinary register as floating point value | |
6257 | (although you can @emph{print} it as a floating point value with | |
6258 | @samp{print/f $@var{regname}}). | |
6259 | ||
6260 | Some registers have distinct ``raw'' and ``virtual'' data formats. This | |
6261 | means that the data format in which the register contents are saved by | |
6262 | the operating system is not the same one that your program normally | |
6263 | sees. For example, the registers of the 68881 floating point | |
6264 | coprocessor are always saved in ``extended'' (raw) format, but all C | |
6265 | programs expect to work with ``double'' (virtual) format. In such | |
5d161b24 | 6266 | cases, @value{GDBN} normally works with the virtual format only (the format |
c906108c SS |
6267 | that makes sense for your program), but the @code{info registers} command |
6268 | prints the data in both formats. | |
6269 | ||
6270 | Normally, register values are relative to the selected stack frame | |
6271 | (@pxref{Selection, ,Selecting a frame}). This means that you get the | |
6272 | value that the register would contain if all stack frames farther in | |
6273 | were exited and their saved registers restored. In order to see the | |
6274 | true contents of hardware registers, you must select the innermost | |
6275 | frame (with @samp{frame 0}). | |
6276 | ||
6277 | However, @value{GDBN} must deduce where registers are saved, from the machine | |
6278 | code generated by your compiler. If some registers are not saved, or if | |
6279 | @value{GDBN} is unable to locate the saved registers, the selected stack | |
6280 | frame makes no difference. | |
6281 | ||
6d2ebf8b | 6282 | @node Floating Point Hardware |
c906108c SS |
6283 | @section Floating point hardware |
6284 | @cindex floating point | |
6285 | ||
6286 | Depending on the configuration, @value{GDBN} may be able to give | |
6287 | you more information about the status of the floating point hardware. | |
6288 | ||
6289 | @table @code | |
6290 | @kindex info float | |
6291 | @item info float | |
6292 | Display hardware-dependent information about the floating | |
6293 | point unit. The exact contents and layout vary depending on the | |
6294 | floating point chip. Currently, @samp{info float} is supported on | |
6295 | the ARM and x86 machines. | |
6296 | @end table | |
c906108c | 6297 | |
e76f1f2e AC |
6298 | @node Vector Unit |
6299 | @section Vector Unit | |
6300 | @cindex vector unit | |
6301 | ||
6302 | Depending on the configuration, @value{GDBN} may be able to give you | |
6303 | more information about the status of the vector unit. | |
6304 | ||
6305 | @table @code | |
6306 | @kindex info vector | |
6307 | @item info vector | |
6308 | Display information about the vector unit. The exact contents and | |
6309 | layout vary depending on the hardware. | |
6310 | @end table | |
6311 | ||
721c2651 EZ |
6312 | @node OS Information |
6313 | @section Operating system auxiliary information | |
6314 | @cindex OS information | |
6315 | ||
6316 | @value{GDBN} provides interfaces to useful OS facilities that can help | |
6317 | you debug your program. | |
6318 | ||
6319 | @cindex @code{ptrace} system call | |
6320 | @cindex @code{struct user} contents | |
6321 | When @value{GDBN} runs on a @dfn{Posix system} (such as GNU or Unix | |
6322 | machines), it interfaces with the inferior via the @code{ptrace} | |
6323 | system call. The operating system creates a special sata structure, | |
6324 | called @code{struct user}, for this interface. You can use the | |
6325 | command @code{info udot} to display the contents of this data | |
6326 | structure. | |
6327 | ||
6328 | @table @code | |
6329 | @item info udot | |
6330 | @kindex info udot | |
6331 | Display the contents of the @code{struct user} maintained by the OS | |
6332 | kernel for the program being debugged. @value{GDBN} displays the | |
6333 | contents of @code{struct user} as a list of hex numbers, similar to | |
6334 | the @code{examine} command. | |
6335 | @end table | |
6336 | ||
b383017d RM |
6337 | @cindex auxiliary vector |
6338 | @cindex vector, auxiliary | |
b383017d RM |
6339 | Some operating systems supply an @dfn{auxiliary vector} to programs at |
6340 | startup. This is akin to the arguments and environment that you | |
6341 | specify for a program, but contains a system-dependent variety of | |
6342 | binary values that tell system libraries important details about the | |
6343 | hardware, operating system, and process. Each value's purpose is | |
6344 | identified by an integer tag; the meanings are well-known but system-specific. | |
6345 | Depending on the configuration and operating system facilities, | |
9c16f35a EZ |
6346 | @value{GDBN} may be able to show you this information. For remote |
6347 | targets, this functionality may further depend on the remote stub's | |
6348 | support of the @samp{qPart:auxv:read} packet, see @ref{Remote | |
6349 | configuration, auxiliary vector}. | |
b383017d RM |
6350 | |
6351 | @table @code | |
6352 | @kindex info auxv | |
6353 | @item info auxv | |
6354 | Display the auxiliary vector of the inferior, which can be either a | |
e4937fc1 | 6355 | live process or a core dump file. @value{GDBN} prints each tag value |
b383017d RM |
6356 | numerically, and also shows names and text descriptions for recognized |
6357 | tags. Some values in the vector are numbers, some bit masks, and some | |
e4937fc1 | 6358 | pointers to strings or other data. @value{GDBN} displays each value in the |
b383017d RM |
6359 | most appropriate form for a recognized tag, and in hexadecimal for |
6360 | an unrecognized tag. | |
6361 | @end table | |
6362 | ||
721c2651 | 6363 | |
29e57380 | 6364 | @node Memory Region Attributes |
b383017d | 6365 | @section Memory region attributes |
29e57380 C |
6366 | @cindex memory region attributes |
6367 | ||
b383017d RM |
6368 | @dfn{Memory region attributes} allow you to describe special handling |
6369 | required by regions of your target's memory. @value{GDBN} uses attributes | |
29e57380 C |
6370 | to determine whether to allow certain types of memory accesses; whether to |
6371 | use specific width accesses; and whether to cache target memory. | |
6372 | ||
6373 | Defined memory regions can be individually enabled and disabled. When a | |
6374 | memory region is disabled, @value{GDBN} uses the default attributes when | |
6375 | accessing memory in that region. Similarly, if no memory regions have | |
6376 | been defined, @value{GDBN} uses the default attributes when accessing | |
6377 | all memory. | |
6378 | ||
b383017d | 6379 | When a memory region is defined, it is given a number to identify it; |
29e57380 C |
6380 | to enable, disable, or remove a memory region, you specify that number. |
6381 | ||
6382 | @table @code | |
6383 | @kindex mem | |
bfac230e | 6384 | @item mem @var{lower} @var{upper} @var{attributes}@dots{} |
09d4efe1 EZ |
6385 | Define a memory region bounded by @var{lower} and @var{upper} with |
6386 | attributes @var{attributes}@dots{}, and add it to the list of regions | |
6387 | monitored by @value{GDBN}. Note that @var{upper} == 0 is a special | |
6388 | case: it is treated as the the target's maximum memory address. | |
bfac230e | 6389 | (0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.) |
29e57380 C |
6390 | |
6391 | @kindex delete mem | |
6392 | @item delete mem @var{nums}@dots{} | |
09d4efe1 EZ |
6393 | Remove memory regions @var{nums}@dots{} from the list of regions |
6394 | monitored by @value{GDBN}. | |
29e57380 C |
6395 | |
6396 | @kindex disable mem | |
6397 | @item disable mem @var{nums}@dots{} | |
09d4efe1 | 6398 | Disable monitoring of memory regions @var{nums}@dots{}. |
b383017d | 6399 | A disabled memory region is not forgotten. |
29e57380 C |
6400 | It may be enabled again later. |
6401 | ||
6402 | @kindex enable mem | |
6403 | @item enable mem @var{nums}@dots{} | |
09d4efe1 | 6404 | Enable monitoring of memory regions @var{nums}@dots{}. |
29e57380 C |
6405 | |
6406 | @kindex info mem | |
6407 | @item info mem | |
6408 | Print a table of all defined memory regions, with the following columns | |
09d4efe1 | 6409 | for each region: |
29e57380 C |
6410 | |
6411 | @table @emph | |
6412 | @item Memory Region Number | |
6413 | @item Enabled or Disabled. | |
b383017d | 6414 | Enabled memory regions are marked with @samp{y}. |
29e57380 C |
6415 | Disabled memory regions are marked with @samp{n}. |
6416 | ||
6417 | @item Lo Address | |
6418 | The address defining the inclusive lower bound of the memory region. | |
6419 | ||
6420 | @item Hi Address | |
6421 | The address defining the exclusive upper bound of the memory region. | |
6422 | ||
6423 | @item Attributes | |
6424 | The list of attributes set for this memory region. | |
6425 | @end table | |
6426 | @end table | |
6427 | ||
6428 | ||
6429 | @subsection Attributes | |
6430 | ||
b383017d | 6431 | @subsubsection Memory Access Mode |
29e57380 C |
6432 | The access mode attributes set whether @value{GDBN} may make read or |
6433 | write accesses to a memory region. | |
6434 | ||
6435 | While these attributes prevent @value{GDBN} from performing invalid | |
6436 | memory accesses, they do nothing to prevent the target system, I/O DMA, | |
6437 | etc. from accessing memory. | |
6438 | ||
6439 | @table @code | |
6440 | @item ro | |
6441 | Memory is read only. | |
6442 | @item wo | |
6443 | Memory is write only. | |
6444 | @item rw | |
6ca652b0 | 6445 | Memory is read/write. This is the default. |
29e57380 C |
6446 | @end table |
6447 | ||
6448 | @subsubsection Memory Access Size | |
6449 | The acccess size attributes tells @value{GDBN} to use specific sized | |
6450 | accesses in the memory region. Often memory mapped device registers | |
6451 | require specific sized accesses. If no access size attribute is | |
6452 | specified, @value{GDBN} may use accesses of any size. | |
6453 | ||
6454 | @table @code | |
6455 | @item 8 | |
6456 | Use 8 bit memory accesses. | |
6457 | @item 16 | |
6458 | Use 16 bit memory accesses. | |
6459 | @item 32 | |
6460 | Use 32 bit memory accesses. | |
6461 | @item 64 | |
6462 | Use 64 bit memory accesses. | |
6463 | @end table | |
6464 | ||
6465 | @c @subsubsection Hardware/Software Breakpoints | |
6466 | @c The hardware/software breakpoint attributes set whether @value{GDBN} | |
6467 | @c will use hardware or software breakpoints for the internal breakpoints | |
6468 | @c used by the step, next, finish, until, etc. commands. | |
6469 | @c | |
6470 | @c @table @code | |
6471 | @c @item hwbreak | |
b383017d | 6472 | @c Always use hardware breakpoints |
29e57380 C |
6473 | @c @item swbreak (default) |
6474 | @c @end table | |
6475 | ||
6476 | @subsubsection Data Cache | |
6477 | The data cache attributes set whether @value{GDBN} will cache target | |
6478 | memory. While this generally improves performance by reducing debug | |
6479 | protocol overhead, it can lead to incorrect results because @value{GDBN} | |
6480 | does not know about volatile variables or memory mapped device | |
6481 | registers. | |
6482 | ||
6483 | @table @code | |
6484 | @item cache | |
b383017d | 6485 | Enable @value{GDBN} to cache target memory. |
6ca652b0 EZ |
6486 | @item nocache |
6487 | Disable @value{GDBN} from caching target memory. This is the default. | |
29e57380 C |
6488 | @end table |
6489 | ||
6490 | @c @subsubsection Memory Write Verification | |
b383017d | 6491 | @c The memory write verification attributes set whether @value{GDBN} |
29e57380 C |
6492 | @c will re-reads data after each write to verify the write was successful. |
6493 | @c | |
6494 | @c @table @code | |
6495 | @c @item verify | |
6496 | @c @item noverify (default) | |
6497 | @c @end table | |
6498 | ||
16d9dec6 MS |
6499 | @node Dump/Restore Files |
6500 | @section Copy between memory and a file | |
6501 | @cindex dump/restore files | |
6502 | @cindex append data to a file | |
6503 | @cindex dump data to a file | |
6504 | @cindex restore data from a file | |
16d9dec6 | 6505 | |
df5215a6 JB |
6506 | You can use the commands @code{dump}, @code{append}, and |
6507 | @code{restore} to copy data between target memory and a file. The | |
6508 | @code{dump} and @code{append} commands write data to a file, and the | |
6509 | @code{restore} command reads data from a file back into the inferior's | |
6510 | memory. Files may be in binary, Motorola S-record, Intel hex, or | |
6511 | Tektronix Hex format; however, @value{GDBN} can only append to binary | |
6512 | files. | |
6513 | ||
6514 | @table @code | |
6515 | ||
6516 | @kindex dump | |
6517 | @item dump @r{[}@var{format}@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
6518 | @itemx dump @r{[}@var{format}@r{]} value @var{filename} @var{expr} | |
6519 | Dump the contents of memory from @var{start_addr} to @var{end_addr}, | |
6520 | or the value of @var{expr}, to @var{filename} in the given format. | |
16d9dec6 | 6521 | |
df5215a6 | 6522 | The @var{format} parameter may be any one of: |
16d9dec6 | 6523 | @table @code |
df5215a6 JB |
6524 | @item binary |
6525 | Raw binary form. | |
6526 | @item ihex | |
6527 | Intel hex format. | |
6528 | @item srec | |
6529 | Motorola S-record format. | |
6530 | @item tekhex | |
6531 | Tektronix Hex format. | |
6532 | @end table | |
6533 | ||
6534 | @value{GDBN} uses the same definitions of these formats as the | |
6535 | @sc{gnu} binary utilities, like @samp{objdump} and @samp{objcopy}. If | |
6536 | @var{format} is omitted, @value{GDBN} dumps the data in raw binary | |
6537 | form. | |
6538 | ||
6539 | @kindex append | |
6540 | @item append @r{[}binary@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
6541 | @itemx append @r{[}binary@r{]} value @var{filename} @var{expr} | |
6542 | Append the contents of memory from @var{start_addr} to @var{end_addr}, | |
09d4efe1 | 6543 | or the value of @var{expr}, to the file @var{filename}, in raw binary form. |
df5215a6 JB |
6544 | (@value{GDBN} can only append data to files in raw binary form.) |
6545 | ||
6546 | @kindex restore | |
6547 | @item restore @var{filename} @r{[}binary@r{]} @var{bias} @var{start} @var{end} | |
6548 | Restore the contents of file @var{filename} into memory. The | |
6549 | @code{restore} command can automatically recognize any known @sc{bfd} | |
6550 | file format, except for raw binary. To restore a raw binary file you | |
6551 | must specify the optional keyword @code{binary} after the filename. | |
16d9dec6 | 6552 | |
b383017d | 6553 | If @var{bias} is non-zero, its value will be added to the addresses |
16d9dec6 MS |
6554 | contained in the file. Binary files always start at address zero, so |
6555 | they will be restored at address @var{bias}. Other bfd files have | |
6556 | a built-in location; they will be restored at offset @var{bias} | |
6557 | from that location. | |
6558 | ||
6559 | If @var{start} and/or @var{end} are non-zero, then only data between | |
6560 | file offset @var{start} and file offset @var{end} will be restored. | |
b383017d | 6561 | These offsets are relative to the addresses in the file, before |
16d9dec6 MS |
6562 | the @var{bias} argument is applied. |
6563 | ||
6564 | @end table | |
6565 | ||
384ee23f EZ |
6566 | @node Core File Generation |
6567 | @section How to Produce a Core File from Your Program | |
6568 | @cindex dump core from inferior | |
6569 | ||
6570 | A @dfn{core file} or @dfn{core dump} is a file that records the memory | |
6571 | image of a running process and its process status (register values | |
6572 | etc.). Its primary use is post-mortem debugging of a program that | |
6573 | crashed while it ran outside a debugger. A program that crashes | |
6574 | automatically produces a core file, unless this feature is disabled by | |
6575 | the user. @xref{Files}, for information on invoking @value{GDBN} in | |
6576 | the post-mortem debugging mode. | |
6577 | ||
6578 | Occasionally, you may wish to produce a core file of the program you | |
6579 | are debugging in order to preserve a snapshot of its state. | |
6580 | @value{GDBN} has a special command for that. | |
6581 | ||
6582 | @table @code | |
6583 | @kindex gcore | |
6584 | @kindex generate-core-file | |
6585 | @item generate-core-file [@var{file}] | |
6586 | @itemx gcore [@var{file}] | |
6587 | Produce a core dump of the inferior process. The optional argument | |
6588 | @var{file} specifies the file name where to put the core dump. If not | |
6589 | specified, the file name defaults to @file{core.@var{pid}}, where | |
6590 | @var{pid} is the inferior process ID. | |
6591 | ||
6592 | Note that this command is implemented only for some systems (as of | |
6593 | this writing, @sc{gnu}/Linux, FreeBSD, Solaris, Unixware, and S390). | |
6594 | @end table | |
6595 | ||
a0eb71c5 KB |
6596 | @node Character Sets |
6597 | @section Character Sets | |
6598 | @cindex character sets | |
6599 | @cindex charset | |
6600 | @cindex translating between character sets | |
6601 | @cindex host character set | |
6602 | @cindex target character set | |
6603 | ||
6604 | If the program you are debugging uses a different character set to | |
6605 | represent characters and strings than the one @value{GDBN} uses itself, | |
6606 | @value{GDBN} can automatically translate between the character sets for | |
6607 | you. The character set @value{GDBN} uses we call the @dfn{host | |
6608 | character set}; the one the inferior program uses we call the | |
6609 | @dfn{target character set}. | |
6610 | ||
6611 | For example, if you are running @value{GDBN} on a @sc{gnu}/Linux system, which | |
6612 | uses the ISO Latin 1 character set, but you are using @value{GDBN}'s | |
6613 | remote protocol (@pxref{Remote,Remote Debugging}) to debug a program | |
6614 | running on an IBM mainframe, which uses the @sc{ebcdic} character set, | |
6615 | then the host character set is Latin-1, and the target character set is | |
6616 | @sc{ebcdic}. If you give @value{GDBN} the command @code{set | |
e33d66ec | 6617 | target-charset EBCDIC-US}, then @value{GDBN} translates between |
a0eb71c5 KB |
6618 | @sc{ebcdic} and Latin 1 as you print character or string values, or use |
6619 | character and string literals in expressions. | |
6620 | ||
6621 | @value{GDBN} has no way to automatically recognize which character set | |
6622 | the inferior program uses; you must tell it, using the @code{set | |
6623 | target-charset} command, described below. | |
6624 | ||
6625 | Here are the commands for controlling @value{GDBN}'s character set | |
6626 | support: | |
6627 | ||
6628 | @table @code | |
6629 | @item set target-charset @var{charset} | |
6630 | @kindex set target-charset | |
6631 | Set the current target character set to @var{charset}. We list the | |
e33d66ec EZ |
6632 | character set names @value{GDBN} recognizes below, but if you type |
6633 | @code{set target-charset} followed by @key{TAB}@key{TAB}, @value{GDBN} will | |
6634 | list the target character sets it supports. | |
a0eb71c5 KB |
6635 | @end table |
6636 | ||
6637 | @table @code | |
6638 | @item set host-charset @var{charset} | |
6639 | @kindex set host-charset | |
6640 | Set the current host character set to @var{charset}. | |
6641 | ||
6642 | By default, @value{GDBN} uses a host character set appropriate to the | |
6643 | system it is running on; you can override that default using the | |
6644 | @code{set host-charset} command. | |
6645 | ||
6646 | @value{GDBN} can only use certain character sets as its host character | |
6647 | set. We list the character set names @value{GDBN} recognizes below, and | |
e33d66ec EZ |
6648 | indicate which can be host character sets, but if you type |
6649 | @code{set target-charset} followed by @key{TAB}@key{TAB}, @value{GDBN} will | |
6650 | list the host character sets it supports. | |
a0eb71c5 KB |
6651 | |
6652 | @item set charset @var{charset} | |
6653 | @kindex set charset | |
e33d66ec EZ |
6654 | Set the current host and target character sets to @var{charset}. As |
6655 | above, if you type @code{set charset} followed by @key{TAB}@key{TAB}, | |
6656 | @value{GDBN} will list the name of the character sets that can be used | |
6657 | for both host and target. | |
6658 | ||
a0eb71c5 KB |
6659 | |
6660 | @item show charset | |
a0eb71c5 | 6661 | @kindex show charset |
b383017d | 6662 | Show the names of the current host and target charsets. |
e33d66ec EZ |
6663 | |
6664 | @itemx show host-charset | |
a0eb71c5 | 6665 | @kindex show host-charset |
b383017d | 6666 | Show the name of the current host charset. |
e33d66ec EZ |
6667 | |
6668 | @itemx show target-charset | |
a0eb71c5 | 6669 | @kindex show target-charset |
b383017d | 6670 | Show the name of the current target charset. |
a0eb71c5 KB |
6671 | |
6672 | @end table | |
6673 | ||
6674 | @value{GDBN} currently includes support for the following character | |
6675 | sets: | |
6676 | ||
6677 | @table @code | |
6678 | ||
6679 | @item ASCII | |
6680 | @cindex ASCII character set | |
6681 | Seven-bit U.S. @sc{ascii}. @value{GDBN} can use this as its host | |
6682 | character set. | |
6683 | ||
6684 | @item ISO-8859-1 | |
6685 | @cindex ISO 8859-1 character set | |
6686 | @cindex ISO Latin 1 character set | |
e33d66ec | 6687 | The ISO Latin 1 character set. This extends @sc{ascii} with accented |
a0eb71c5 KB |
6688 | characters needed for French, German, and Spanish. @value{GDBN} can use |
6689 | this as its host character set. | |
6690 | ||
6691 | @item EBCDIC-US | |
6692 | @itemx IBM1047 | |
6693 | @cindex EBCDIC character set | |
6694 | @cindex IBM1047 character set | |
6695 | Variants of the @sc{ebcdic} character set, used on some of IBM's | |
6696 | mainframe operating systems. (@sc{gnu}/Linux on the S/390 uses U.S. @sc{ascii}.) | |
6697 | @value{GDBN} cannot use these as its host character set. | |
6698 | ||
6699 | @end table | |
6700 | ||
6701 | Note that these are all single-byte character sets. More work inside | |
6702 | GDB is needed to support multi-byte or variable-width character | |
6703 | encodings, like the UTF-8 and UCS-2 encodings of Unicode. | |
6704 | ||
6705 | Here is an example of @value{GDBN}'s character set support in action. | |
6706 | Assume that the following source code has been placed in the file | |
6707 | @file{charset-test.c}: | |
6708 | ||
6709 | @smallexample | |
6710 | #include <stdio.h> | |
6711 | ||
6712 | char ascii_hello[] | |
6713 | = @{72, 101, 108, 108, 111, 44, 32, 119, | |
6714 | 111, 114, 108, 100, 33, 10, 0@}; | |
6715 | char ibm1047_hello[] | |
6716 | = @{200, 133, 147, 147, 150, 107, 64, 166, | |
6717 | 150, 153, 147, 132, 90, 37, 0@}; | |
6718 | ||
6719 | main () | |
6720 | @{ | |
6721 | printf ("Hello, world!\n"); | |
6722 | @} | |
10998722 | 6723 | @end smallexample |
a0eb71c5 KB |
6724 | |
6725 | In this program, @code{ascii_hello} and @code{ibm1047_hello} are arrays | |
6726 | containing the string @samp{Hello, world!} followed by a newline, | |
6727 | encoded in the @sc{ascii} and @sc{ibm1047} character sets. | |
6728 | ||
6729 | We compile the program, and invoke the debugger on it: | |
6730 | ||
6731 | @smallexample | |
6732 | $ gcc -g charset-test.c -o charset-test | |
6733 | $ gdb -nw charset-test | |
6734 | GNU gdb 2001-12-19-cvs | |
6735 | Copyright 2001 Free Software Foundation, Inc. | |
6736 | @dots{} | |
f7dc1244 | 6737 | (@value{GDBP}) |
10998722 | 6738 | @end smallexample |
a0eb71c5 KB |
6739 | |
6740 | We can use the @code{show charset} command to see what character sets | |
6741 | @value{GDBN} is currently using to interpret and display characters and | |
6742 | strings: | |
6743 | ||
6744 | @smallexample | |
f7dc1244 | 6745 | (@value{GDBP}) show charset |
e33d66ec | 6746 | The current host and target character set is `ISO-8859-1'. |
f7dc1244 | 6747 | (@value{GDBP}) |
10998722 | 6748 | @end smallexample |
a0eb71c5 KB |
6749 | |
6750 | For the sake of printing this manual, let's use @sc{ascii} as our | |
6751 | initial character set: | |
6752 | @smallexample | |
f7dc1244 EZ |
6753 | (@value{GDBP}) set charset ASCII |
6754 | (@value{GDBP}) show charset | |
e33d66ec | 6755 | The current host and target character set is `ASCII'. |
f7dc1244 | 6756 | (@value{GDBP}) |
10998722 | 6757 | @end smallexample |
a0eb71c5 KB |
6758 | |
6759 | Let's assume that @sc{ascii} is indeed the correct character set for our | |
6760 | host system --- in other words, let's assume that if @value{GDBN} prints | |
6761 | characters using the @sc{ascii} character set, our terminal will display | |
6762 | them properly. Since our current target character set is also | |
6763 | @sc{ascii}, the contents of @code{ascii_hello} print legibly: | |
6764 | ||
6765 | @smallexample | |
f7dc1244 | 6766 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 6767 | $1 = 0x401698 "Hello, world!\n" |
f7dc1244 | 6768 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 6769 | $2 = 72 'H' |
f7dc1244 | 6770 | (@value{GDBP}) |
10998722 | 6771 | @end smallexample |
a0eb71c5 KB |
6772 | |
6773 | @value{GDBN} uses the target character set for character and string | |
6774 | literals you use in expressions: | |
6775 | ||
6776 | @smallexample | |
f7dc1244 | 6777 | (@value{GDBP}) print '+' |
a0eb71c5 | 6778 | $3 = 43 '+' |
f7dc1244 | 6779 | (@value{GDBP}) |
10998722 | 6780 | @end smallexample |
a0eb71c5 KB |
6781 | |
6782 | The @sc{ascii} character set uses the number 43 to encode the @samp{+} | |
6783 | character. | |
6784 | ||
6785 | @value{GDBN} relies on the user to tell it which character set the | |
6786 | target program uses. If we print @code{ibm1047_hello} while our target | |
6787 | character set is still @sc{ascii}, we get jibberish: | |
6788 | ||
6789 | @smallexample | |
f7dc1244 | 6790 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 6791 | $4 = 0x4016a8 "\310\205\223\223\226k@@\246\226\231\223\204Z%" |
f7dc1244 | 6792 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 6793 | $5 = 200 '\310' |
f7dc1244 | 6794 | (@value{GDBP}) |
10998722 | 6795 | @end smallexample |
a0eb71c5 | 6796 | |
e33d66ec | 6797 | If we invoke the @code{set target-charset} followed by @key{TAB}@key{TAB}, |
a0eb71c5 KB |
6798 | @value{GDBN} tells us the character sets it supports: |
6799 | ||
6800 | @smallexample | |
f7dc1244 | 6801 | (@value{GDBP}) set target-charset |
b383017d | 6802 | ASCII EBCDIC-US IBM1047 ISO-8859-1 |
f7dc1244 | 6803 | (@value{GDBP}) set target-charset |
10998722 | 6804 | @end smallexample |
a0eb71c5 KB |
6805 | |
6806 | We can select @sc{ibm1047} as our target character set, and examine the | |
6807 | program's strings again. Now the @sc{ascii} string is wrong, but | |
6808 | @value{GDBN} translates the contents of @code{ibm1047_hello} from the | |
6809 | target character set, @sc{ibm1047}, to the host character set, | |
6810 | @sc{ascii}, and they display correctly: | |
6811 | ||
6812 | @smallexample | |
f7dc1244 EZ |
6813 | (@value{GDBP}) set target-charset IBM1047 |
6814 | (@value{GDBP}) show charset | |
e33d66ec EZ |
6815 | The current host character set is `ASCII'. |
6816 | The current target character set is `IBM1047'. | |
f7dc1244 | 6817 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 6818 | $6 = 0x401698 "\110\145%%?\054\040\167?\162%\144\041\012" |
f7dc1244 | 6819 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 6820 | $7 = 72 '\110' |
f7dc1244 | 6821 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 6822 | $8 = 0x4016a8 "Hello, world!\n" |
f7dc1244 | 6823 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 6824 | $9 = 200 'H' |
f7dc1244 | 6825 | (@value{GDBP}) |
10998722 | 6826 | @end smallexample |
a0eb71c5 KB |
6827 | |
6828 | As above, @value{GDBN} uses the target character set for character and | |
6829 | string literals you use in expressions: | |
6830 | ||
6831 | @smallexample | |
f7dc1244 | 6832 | (@value{GDBP}) print '+' |
a0eb71c5 | 6833 | $10 = 78 '+' |
f7dc1244 | 6834 | (@value{GDBP}) |
10998722 | 6835 | @end smallexample |
a0eb71c5 | 6836 | |
e33d66ec | 6837 | The @sc{ibm1047} character set uses the number 78 to encode the @samp{+} |
a0eb71c5 KB |
6838 | character. |
6839 | ||
09d4efe1 EZ |
6840 | @node Caching Remote Data |
6841 | @section Caching Data of Remote Targets | |
6842 | @cindex caching data of remote targets | |
6843 | ||
6844 | @value{GDBN} can cache data exchanged between the debugger and a | |
6845 | remote target (@pxref{Remote}). Such caching generally improves | |
6846 | performance, because it reduces the overhead of the remote protocol by | |
6847 | bundling memory reads and writes into large chunks. Unfortunately, | |
6848 | @value{GDBN} does not currently know anything about volatile | |
6849 | registers, and thus data caching will produce incorrect results when | |
6850 | volatile registers are in use. | |
6851 | ||
6852 | @table @code | |
6853 | @kindex set remotecache | |
6854 | @item set remotecache on | |
6855 | @itemx set remotecache off | |
6856 | Set caching state for remote targets. When @code{ON}, use data | |
6857 | caching. By default, this option is @code{OFF}. | |
6858 | ||
6859 | @kindex show remotecache | |
6860 | @item show remotecache | |
6861 | Show the current state of data caching for remote targets. | |
6862 | ||
6863 | @kindex info dcache | |
6864 | @item info dcache | |
6865 | Print the information about the data cache performance. The | |
6866 | information displayed includes: the dcache width and depth; and for | |
6867 | each cache line, how many times it was referenced, and its data and | |
6868 | state (dirty, bad, ok, etc.). This command is useful for debugging | |
6869 | the data cache operation. | |
6870 | @end table | |
6871 | ||
a0eb71c5 | 6872 | |
e2e0bcd1 JB |
6873 | @node Macros |
6874 | @chapter C Preprocessor Macros | |
6875 | ||
49efadf5 | 6876 | Some languages, such as C and C@t{++}, provide a way to define and invoke |
e2e0bcd1 JB |
6877 | ``preprocessor macros'' which expand into strings of tokens. |
6878 | @value{GDBN} can evaluate expressions containing macro invocations, show | |
6879 | the result of macro expansion, and show a macro's definition, including | |
6880 | where it was defined. | |
6881 | ||
6882 | You may need to compile your program specially to provide @value{GDBN} | |
6883 | with information about preprocessor macros. Most compilers do not | |
6884 | include macros in their debugging information, even when you compile | |
6885 | with the @option{-g} flag. @xref{Compilation}. | |
6886 | ||
6887 | A program may define a macro at one point, remove that definition later, | |
6888 | and then provide a different definition after that. Thus, at different | |
6889 | points in the program, a macro may have different definitions, or have | |
6890 | no definition at all. If there is a current stack frame, @value{GDBN} | |
6891 | uses the macros in scope at that frame's source code line. Otherwise, | |
6892 | @value{GDBN} uses the macros in scope at the current listing location; | |
6893 | see @ref{List}. | |
6894 | ||
6895 | At the moment, @value{GDBN} does not support the @code{##} | |
6896 | token-splicing operator, the @code{#} stringification operator, or | |
6897 | variable-arity macros. | |
6898 | ||
6899 | Whenever @value{GDBN} evaluates an expression, it always expands any | |
6900 | macro invocations present in the expression. @value{GDBN} also provides | |
6901 | the following commands for working with macros explicitly. | |
6902 | ||
6903 | @table @code | |
6904 | ||
6905 | @kindex macro expand | |
6906 | @cindex macro expansion, showing the results of preprocessor | |
6907 | @cindex preprocessor macro expansion, showing the results of | |
6908 | @cindex expanding preprocessor macros | |
6909 | @item macro expand @var{expression} | |
6910 | @itemx macro exp @var{expression} | |
6911 | Show the results of expanding all preprocessor macro invocations in | |
6912 | @var{expression}. Since @value{GDBN} simply expands macros, but does | |
6913 | not parse the result, @var{expression} need not be a valid expression; | |
6914 | it can be any string of tokens. | |
6915 | ||
09d4efe1 | 6916 | @kindex macro exp1 |
e2e0bcd1 JB |
6917 | @item macro expand-once @var{expression} |
6918 | @itemx macro exp1 @var{expression} | |
4644b6e3 | 6919 | @cindex expand macro once |
e2e0bcd1 JB |
6920 | @i{(This command is not yet implemented.)} Show the results of |
6921 | expanding those preprocessor macro invocations that appear explicitly in | |
6922 | @var{expression}. Macro invocations appearing in that expansion are | |
6923 | left unchanged. This command allows you to see the effect of a | |
6924 | particular macro more clearly, without being confused by further | |
6925 | expansions. Since @value{GDBN} simply expands macros, but does not | |
6926 | parse the result, @var{expression} need not be a valid expression; it | |
6927 | can be any string of tokens. | |
6928 | ||
475b0867 | 6929 | @kindex info macro |
e2e0bcd1 JB |
6930 | @cindex macro definition, showing |
6931 | @cindex definition, showing a macro's | |
475b0867 | 6932 | @item info macro @var{macro} |
e2e0bcd1 JB |
6933 | Show the definition of the macro named @var{macro}, and describe the |
6934 | source location where that definition was established. | |
6935 | ||
6936 | @kindex macro define | |
6937 | @cindex user-defined macros | |
6938 | @cindex defining macros interactively | |
6939 | @cindex macros, user-defined | |
6940 | @item macro define @var{macro} @var{replacement-list} | |
6941 | @itemx macro define @var{macro}(@var{arglist}) @var{replacement-list} | |
6942 | @i{(This command is not yet implemented.)} Introduce a definition for a | |
6943 | preprocessor macro named @var{macro}, invocations of which are replaced | |
6944 | by the tokens given in @var{replacement-list}. The first form of this | |
6945 | command defines an ``object-like'' macro, which takes no arguments; the | |
6946 | second form defines a ``function-like'' macro, which takes the arguments | |
6947 | given in @var{arglist}. | |
6948 | ||
6949 | A definition introduced by this command is in scope in every expression | |
6950 | evaluated in @value{GDBN}, until it is removed with the @command{macro | |
6951 | undef} command, described below. The definition overrides all | |
6952 | definitions for @var{macro} present in the program being debugged, as | |
6953 | well as any previous user-supplied definition. | |
6954 | ||
6955 | @kindex macro undef | |
6956 | @item macro undef @var{macro} | |
6957 | @i{(This command is not yet implemented.)} Remove any user-supplied | |
6958 | definition for the macro named @var{macro}. This command only affects | |
6959 | definitions provided with the @command{macro define} command, described | |
6960 | above; it cannot remove definitions present in the program being | |
6961 | debugged. | |
6962 | ||
09d4efe1 EZ |
6963 | @kindex macro list |
6964 | @item macro list | |
6965 | @i{(This command is not yet implemented.)} List all the macros | |
6966 | defined using the @code{macro define} command. | |
e2e0bcd1 JB |
6967 | @end table |
6968 | ||
6969 | @cindex macros, example of debugging with | |
6970 | Here is a transcript showing the above commands in action. First, we | |
6971 | show our source files: | |
6972 | ||
6973 | @smallexample | |
6974 | $ cat sample.c | |
6975 | #include <stdio.h> | |
6976 | #include "sample.h" | |
6977 | ||
6978 | #define M 42 | |
6979 | #define ADD(x) (M + x) | |
6980 | ||
6981 | main () | |
6982 | @{ | |
6983 | #define N 28 | |
6984 | printf ("Hello, world!\n"); | |
6985 | #undef N | |
6986 | printf ("We're so creative.\n"); | |
6987 | #define N 1729 | |
6988 | printf ("Goodbye, world!\n"); | |
6989 | @} | |
6990 | $ cat sample.h | |
6991 | #define Q < | |
6992 | $ | |
6993 | @end smallexample | |
6994 | ||
6995 | Now, we compile the program using the @sc{gnu} C compiler, @value{NGCC}. | |
6996 | We pass the @option{-gdwarf-2} and @option{-g3} flags to ensure the | |
6997 | compiler includes information about preprocessor macros in the debugging | |
6998 | information. | |
6999 | ||
7000 | @smallexample | |
7001 | $ gcc -gdwarf-2 -g3 sample.c -o sample | |
7002 | $ | |
7003 | @end smallexample | |
7004 | ||
7005 | Now, we start @value{GDBN} on our sample program: | |
7006 | ||
7007 | @smallexample | |
7008 | $ gdb -nw sample | |
7009 | GNU gdb 2002-05-06-cvs | |
7010 | Copyright 2002 Free Software Foundation, Inc. | |
7011 | GDB is free software, @dots{} | |
f7dc1244 | 7012 | (@value{GDBP}) |
e2e0bcd1 JB |
7013 | @end smallexample |
7014 | ||
7015 | We can expand macros and examine their definitions, even when the | |
7016 | program is not running. @value{GDBN} uses the current listing position | |
7017 | to decide which macro definitions are in scope: | |
7018 | ||
7019 | @smallexample | |
f7dc1244 | 7020 | (@value{GDBP}) list main |
e2e0bcd1 JB |
7021 | 3 |
7022 | 4 #define M 42 | |
7023 | 5 #define ADD(x) (M + x) | |
7024 | 6 | |
7025 | 7 main () | |
7026 | 8 @{ | |
7027 | 9 #define N 28 | |
7028 | 10 printf ("Hello, world!\n"); | |
7029 | 11 #undef N | |
7030 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 7031 | (@value{GDBP}) info macro ADD |
e2e0bcd1 JB |
7032 | Defined at /home/jimb/gdb/macros/play/sample.c:5 |
7033 | #define ADD(x) (M + x) | |
f7dc1244 | 7034 | (@value{GDBP}) info macro Q |
e2e0bcd1 JB |
7035 | Defined at /home/jimb/gdb/macros/play/sample.h:1 |
7036 | included at /home/jimb/gdb/macros/play/sample.c:2 | |
7037 | #define Q < | |
f7dc1244 | 7038 | (@value{GDBP}) macro expand ADD(1) |
e2e0bcd1 | 7039 | expands to: (42 + 1) |
f7dc1244 | 7040 | (@value{GDBP}) macro expand-once ADD(1) |
e2e0bcd1 | 7041 | expands to: once (M + 1) |
f7dc1244 | 7042 | (@value{GDBP}) |
e2e0bcd1 JB |
7043 | @end smallexample |
7044 | ||
7045 | In the example above, note that @command{macro expand-once} expands only | |
7046 | the macro invocation explicit in the original text --- the invocation of | |
7047 | @code{ADD} --- but does not expand the invocation of the macro @code{M}, | |
7048 | which was introduced by @code{ADD}. | |
7049 | ||
7050 | Once the program is running, GDB uses the macro definitions in force at | |
7051 | the source line of the current stack frame: | |
7052 | ||
7053 | @smallexample | |
f7dc1244 | 7054 | (@value{GDBP}) break main |
e2e0bcd1 | 7055 | Breakpoint 1 at 0x8048370: file sample.c, line 10. |
f7dc1244 | 7056 | (@value{GDBP}) run |
b383017d | 7057 | Starting program: /home/jimb/gdb/macros/play/sample |
e2e0bcd1 JB |
7058 | |
7059 | Breakpoint 1, main () at sample.c:10 | |
7060 | 10 printf ("Hello, world!\n"); | |
f7dc1244 | 7061 | (@value{GDBP}) |
e2e0bcd1 JB |
7062 | @end smallexample |
7063 | ||
7064 | At line 10, the definition of the macro @code{N} at line 9 is in force: | |
7065 | ||
7066 | @smallexample | |
f7dc1244 | 7067 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
7068 | Defined at /home/jimb/gdb/macros/play/sample.c:9 |
7069 | #define N 28 | |
f7dc1244 | 7070 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 7071 | expands to: 28 < 42 |
f7dc1244 | 7072 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 7073 | $1 = 1 |
f7dc1244 | 7074 | (@value{GDBP}) |
e2e0bcd1 JB |
7075 | @end smallexample |
7076 | ||
7077 | As we step over directives that remove @code{N}'s definition, and then | |
7078 | give it a new definition, @value{GDBN} finds the definition (or lack | |
7079 | thereof) in force at each point: | |
7080 | ||
7081 | @smallexample | |
f7dc1244 | 7082 | (@value{GDBP}) next |
e2e0bcd1 JB |
7083 | Hello, world! |
7084 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 7085 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
7086 | The symbol `N' has no definition as a C/C++ preprocessor macro |
7087 | at /home/jimb/gdb/macros/play/sample.c:12 | |
f7dc1244 | 7088 | (@value{GDBP}) next |
e2e0bcd1 JB |
7089 | We're so creative. |
7090 | 14 printf ("Goodbye, world!\n"); | |
f7dc1244 | 7091 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
7092 | Defined at /home/jimb/gdb/macros/play/sample.c:13 |
7093 | #define N 1729 | |
f7dc1244 | 7094 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 7095 | expands to: 1729 < 42 |
f7dc1244 | 7096 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 7097 | $2 = 0 |
f7dc1244 | 7098 | (@value{GDBP}) |
e2e0bcd1 JB |
7099 | @end smallexample |
7100 | ||
7101 | ||
b37052ae EZ |
7102 | @node Tracepoints |
7103 | @chapter Tracepoints | |
7104 | @c This chapter is based on the documentation written by Michael | |
7105 | @c Snyder, David Taylor, Jim Blandy, and Elena Zannoni. | |
7106 | ||
7107 | @cindex tracepoints | |
7108 | In some applications, it is not feasible for the debugger to interrupt | |
7109 | the program's execution long enough for the developer to learn | |
7110 | anything helpful about its behavior. If the program's correctness | |
7111 | depends on its real-time behavior, delays introduced by a debugger | |
7112 | might cause the program to change its behavior drastically, or perhaps | |
7113 | fail, even when the code itself is correct. It is useful to be able | |
7114 | to observe the program's behavior without interrupting it. | |
7115 | ||
7116 | Using @value{GDBN}'s @code{trace} and @code{collect} commands, you can | |
7117 | specify locations in the program, called @dfn{tracepoints}, and | |
7118 | arbitrary expressions to evaluate when those tracepoints are reached. | |
7119 | Later, using the @code{tfind} command, you can examine the values | |
7120 | those expressions had when the program hit the tracepoints. The | |
7121 | expressions may also denote objects in memory---structures or arrays, | |
7122 | for example---whose values @value{GDBN} should record; while visiting | |
7123 | a particular tracepoint, you may inspect those objects as if they were | |
7124 | in memory at that moment. However, because @value{GDBN} records these | |
7125 | values without interacting with you, it can do so quickly and | |
7126 | unobtrusively, hopefully not disturbing the program's behavior. | |
7127 | ||
7128 | The tracepoint facility is currently available only for remote | |
9d29849a JB |
7129 | targets. @xref{Targets}. In addition, your remote target must know |
7130 | how to collect trace data. This functionality is implemented in the | |
7131 | remote stub; however, none of the stubs distributed with @value{GDBN} | |
7132 | support tracepoints as of this writing. The format of the remote | |
7133 | packets used to implement tracepoints are described in @ref{Tracepoint | |
7134 | Packets}. | |
b37052ae EZ |
7135 | |
7136 | This chapter describes the tracepoint commands and features. | |
7137 | ||
7138 | @menu | |
b383017d RM |
7139 | * Set Tracepoints:: |
7140 | * Analyze Collected Data:: | |
7141 | * Tracepoint Variables:: | |
b37052ae EZ |
7142 | @end menu |
7143 | ||
7144 | @node Set Tracepoints | |
7145 | @section Commands to Set Tracepoints | |
7146 | ||
7147 | Before running such a @dfn{trace experiment}, an arbitrary number of | |
7148 | tracepoints can be set. Like a breakpoint (@pxref{Set Breaks}), a | |
7149 | tracepoint has a number assigned to it by @value{GDBN}. Like with | |
7150 | breakpoints, tracepoint numbers are successive integers starting from | |
7151 | one. Many of the commands associated with tracepoints take the | |
7152 | tracepoint number as their argument, to identify which tracepoint to | |
7153 | work on. | |
7154 | ||
7155 | For each tracepoint, you can specify, in advance, some arbitrary set | |
7156 | of data that you want the target to collect in the trace buffer when | |
7157 | it hits that tracepoint. The collected data can include registers, | |
7158 | local variables, or global data. Later, you can use @value{GDBN} | |
7159 | commands to examine the values these data had at the time the | |
7160 | tracepoint was hit. | |
7161 | ||
7162 | This section describes commands to set tracepoints and associated | |
7163 | conditions and actions. | |
7164 | ||
7165 | @menu | |
b383017d RM |
7166 | * Create and Delete Tracepoints:: |
7167 | * Enable and Disable Tracepoints:: | |
7168 | * Tracepoint Passcounts:: | |
7169 | * Tracepoint Actions:: | |
7170 | * Listing Tracepoints:: | |
7171 | * Starting and Stopping Trace Experiment:: | |
b37052ae EZ |
7172 | @end menu |
7173 | ||
7174 | @node Create and Delete Tracepoints | |
7175 | @subsection Create and Delete Tracepoints | |
7176 | ||
7177 | @table @code | |
7178 | @cindex set tracepoint | |
7179 | @kindex trace | |
7180 | @item trace | |
7181 | The @code{trace} command is very similar to the @code{break} command. | |
7182 | Its argument can be a source line, a function name, or an address in | |
7183 | the target program. @xref{Set Breaks}. The @code{trace} command | |
7184 | defines a tracepoint, which is a point in the target program where the | |
7185 | debugger will briefly stop, collect some data, and then allow the | |
7186 | program to continue. Setting a tracepoint or changing its commands | |
7187 | doesn't take effect until the next @code{tstart} command; thus, you | |
7188 | cannot change the tracepoint attributes once a trace experiment is | |
7189 | running. | |
7190 | ||
7191 | Here are some examples of using the @code{trace} command: | |
7192 | ||
7193 | @smallexample | |
7194 | (@value{GDBP}) @b{trace foo.c:121} // a source file and line number | |
7195 | ||
7196 | (@value{GDBP}) @b{trace +2} // 2 lines forward | |
7197 | ||
7198 | (@value{GDBP}) @b{trace my_function} // first source line of function | |
7199 | ||
7200 | (@value{GDBP}) @b{trace *my_function} // EXACT start address of function | |
7201 | ||
7202 | (@value{GDBP}) @b{trace *0x2117c4} // an address | |
7203 | @end smallexample | |
7204 | ||
7205 | @noindent | |
7206 | You can abbreviate @code{trace} as @code{tr}. | |
7207 | ||
7208 | @vindex $tpnum | |
7209 | @cindex last tracepoint number | |
7210 | @cindex recent tracepoint number | |
7211 | @cindex tracepoint number | |
7212 | The convenience variable @code{$tpnum} records the tracepoint number | |
7213 | of the most recently set tracepoint. | |
7214 | ||
7215 | @kindex delete tracepoint | |
7216 | @cindex tracepoint deletion | |
7217 | @item delete tracepoint @r{[}@var{num}@r{]} | |
7218 | Permanently delete one or more tracepoints. With no argument, the | |
7219 | default is to delete all tracepoints. | |
7220 | ||
7221 | Examples: | |
7222 | ||
7223 | @smallexample | |
7224 | (@value{GDBP}) @b{delete trace 1 2 3} // remove three tracepoints | |
7225 | ||
7226 | (@value{GDBP}) @b{delete trace} // remove all tracepoints | |
7227 | @end smallexample | |
7228 | ||
7229 | @noindent | |
7230 | You can abbreviate this command as @code{del tr}. | |
7231 | @end table | |
7232 | ||
7233 | @node Enable and Disable Tracepoints | |
7234 | @subsection Enable and Disable Tracepoints | |
7235 | ||
7236 | @table @code | |
7237 | @kindex disable tracepoint | |
7238 | @item disable tracepoint @r{[}@var{num}@r{]} | |
7239 | Disable tracepoint @var{num}, or all tracepoints if no argument | |
7240 | @var{num} is given. A disabled tracepoint will have no effect during | |
7241 | the next trace experiment, but it is not forgotten. You can re-enable | |
7242 | a disabled tracepoint using the @code{enable tracepoint} command. | |
7243 | ||
7244 | @kindex enable tracepoint | |
7245 | @item enable tracepoint @r{[}@var{num}@r{]} | |
7246 | Enable tracepoint @var{num}, or all tracepoints. The enabled | |
7247 | tracepoints will become effective the next time a trace experiment is | |
7248 | run. | |
7249 | @end table | |
7250 | ||
7251 | @node Tracepoint Passcounts | |
7252 | @subsection Tracepoint Passcounts | |
7253 | ||
7254 | @table @code | |
7255 | @kindex passcount | |
7256 | @cindex tracepoint pass count | |
7257 | @item passcount @r{[}@var{n} @r{[}@var{num}@r{]]} | |
7258 | Set the @dfn{passcount} of a tracepoint. The passcount is a way to | |
7259 | automatically stop a trace experiment. If a tracepoint's passcount is | |
7260 | @var{n}, then the trace experiment will be automatically stopped on | |
7261 | the @var{n}'th time that tracepoint is hit. If the tracepoint number | |
7262 | @var{num} is not specified, the @code{passcount} command sets the | |
7263 | passcount of the most recently defined tracepoint. If no passcount is | |
7264 | given, the trace experiment will run until stopped explicitly by the | |
7265 | user. | |
7266 | ||
7267 | Examples: | |
7268 | ||
7269 | @smallexample | |
b383017d | 7270 | (@value{GDBP}) @b{passcount 5 2} // Stop on the 5th execution of |
6826cf00 | 7271 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// tracepoint 2} |
b37052ae EZ |
7272 | |
7273 | (@value{GDBP}) @b{passcount 12} // Stop on the 12th execution of the | |
6826cf00 | 7274 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// most recently defined tracepoint.} |
b37052ae EZ |
7275 | (@value{GDBP}) @b{trace foo} |
7276 | (@value{GDBP}) @b{pass 3} | |
7277 | (@value{GDBP}) @b{trace bar} | |
7278 | (@value{GDBP}) @b{pass 2} | |
7279 | (@value{GDBP}) @b{trace baz} | |
7280 | (@value{GDBP}) @b{pass 1} // Stop tracing when foo has been | |
6826cf00 EZ |
7281 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// executed 3 times OR when bar has} |
7282 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// been executed 2 times} | |
7283 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// OR when baz has been executed 1 time.} | |
b37052ae EZ |
7284 | @end smallexample |
7285 | @end table | |
7286 | ||
7287 | @node Tracepoint Actions | |
7288 | @subsection Tracepoint Action Lists | |
7289 | ||
7290 | @table @code | |
7291 | @kindex actions | |
7292 | @cindex tracepoint actions | |
7293 | @item actions @r{[}@var{num}@r{]} | |
7294 | This command will prompt for a list of actions to be taken when the | |
7295 | tracepoint is hit. If the tracepoint number @var{num} is not | |
7296 | specified, this command sets the actions for the one that was most | |
7297 | recently defined (so that you can define a tracepoint and then say | |
7298 | @code{actions} without bothering about its number). You specify the | |
7299 | actions themselves on the following lines, one action at a time, and | |
7300 | terminate the actions list with a line containing just @code{end}. So | |
7301 | far, the only defined actions are @code{collect} and | |
7302 | @code{while-stepping}. | |
7303 | ||
7304 | @cindex remove actions from a tracepoint | |
7305 | To remove all actions from a tracepoint, type @samp{actions @var{num}} | |
7306 | and follow it immediately with @samp{end}. | |
7307 | ||
7308 | @smallexample | |
7309 | (@value{GDBP}) @b{collect @var{data}} // collect some data | |
7310 | ||
6826cf00 | 7311 | (@value{GDBP}) @b{while-stepping 5} // single-step 5 times, collect data |
b37052ae | 7312 | |
6826cf00 | 7313 | (@value{GDBP}) @b{end} // signals the end of actions. |
b37052ae EZ |
7314 | @end smallexample |
7315 | ||
7316 | In the following example, the action list begins with @code{collect} | |
7317 | commands indicating the things to be collected when the tracepoint is | |
7318 | hit. Then, in order to single-step and collect additional data | |
7319 | following the tracepoint, a @code{while-stepping} command is used, | |
7320 | followed by the list of things to be collected while stepping. The | |
7321 | @code{while-stepping} command is terminated by its own separate | |
7322 | @code{end} command. Lastly, the action list is terminated by an | |
7323 | @code{end} command. | |
7324 | ||
7325 | @smallexample | |
7326 | (@value{GDBP}) @b{trace foo} | |
7327 | (@value{GDBP}) @b{actions} | |
7328 | Enter actions for tracepoint 1, one per line: | |
7329 | > collect bar,baz | |
7330 | > collect $regs | |
7331 | > while-stepping 12 | |
7332 | > collect $fp, $sp | |
7333 | > end | |
7334 | end | |
7335 | @end smallexample | |
7336 | ||
7337 | @kindex collect @r{(tracepoints)} | |
7338 | @item collect @var{expr1}, @var{expr2}, @dots{} | |
7339 | Collect values of the given expressions when the tracepoint is hit. | |
7340 | This command accepts a comma-separated list of any valid expressions. | |
7341 | In addition to global, static, or local variables, the following | |
7342 | special arguments are supported: | |
7343 | ||
7344 | @table @code | |
7345 | @item $regs | |
7346 | collect all registers | |
7347 | ||
7348 | @item $args | |
7349 | collect all function arguments | |
7350 | ||
7351 | @item $locals | |
7352 | collect all local variables. | |
7353 | @end table | |
7354 | ||
7355 | You can give several consecutive @code{collect} commands, each one | |
7356 | with a single argument, or one @code{collect} command with several | |
7357 | arguments separated by commas: the effect is the same. | |
7358 | ||
f5c37c66 EZ |
7359 | The command @code{info scope} (@pxref{Symbols, info scope}) is |
7360 | particularly useful for figuring out what data to collect. | |
7361 | ||
b37052ae EZ |
7362 | @kindex while-stepping @r{(tracepoints)} |
7363 | @item while-stepping @var{n} | |
7364 | Perform @var{n} single-step traces after the tracepoint, collecting | |
7365 | new data at each step. The @code{while-stepping} command is | |
7366 | followed by the list of what to collect while stepping (followed by | |
7367 | its own @code{end} command): | |
7368 | ||
7369 | @smallexample | |
7370 | > while-stepping 12 | |
7371 | > collect $regs, myglobal | |
7372 | > end | |
7373 | > | |
7374 | @end smallexample | |
7375 | ||
7376 | @noindent | |
7377 | You may abbreviate @code{while-stepping} as @code{ws} or | |
7378 | @code{stepping}. | |
7379 | @end table | |
7380 | ||
7381 | @node Listing Tracepoints | |
7382 | @subsection Listing Tracepoints | |
7383 | ||
7384 | @table @code | |
7385 | @kindex info tracepoints | |
09d4efe1 | 7386 | @kindex info tp |
b37052ae EZ |
7387 | @cindex information about tracepoints |
7388 | @item info tracepoints @r{[}@var{num}@r{]} | |
8a037dd7 | 7389 | Display information about the tracepoint @var{num}. If you don't specify |
798c8bc6 | 7390 | a tracepoint number, displays information about all the tracepoints |
b37052ae EZ |
7391 | defined so far. For each tracepoint, the following information is |
7392 | shown: | |
7393 | ||
7394 | @itemize @bullet | |
7395 | @item | |
7396 | its number | |
7397 | @item | |
7398 | whether it is enabled or disabled | |
7399 | @item | |
7400 | its address | |
7401 | @item | |
7402 | its passcount as given by the @code{passcount @var{n}} command | |
7403 | @item | |
7404 | its step count as given by the @code{while-stepping @var{n}} command | |
7405 | @item | |
7406 | where in the source files is the tracepoint set | |
7407 | @item | |
7408 | its action list as given by the @code{actions} command | |
7409 | @end itemize | |
7410 | ||
7411 | @smallexample | |
7412 | (@value{GDBP}) @b{info trace} | |
7413 | Num Enb Address PassC StepC What | |
7414 | 1 y 0x002117c4 0 0 <gdb_asm> | |
6826cf00 EZ |
7415 | 2 y 0x0020dc64 0 0 in g_test at g_test.c:1375 |
7416 | 3 y 0x0020b1f4 0 0 in get_data at ../foo.c:41 | |
b37052ae EZ |
7417 | (@value{GDBP}) |
7418 | @end smallexample | |
7419 | ||
7420 | @noindent | |
7421 | This command can be abbreviated @code{info tp}. | |
7422 | @end table | |
7423 | ||
7424 | @node Starting and Stopping Trace Experiment | |
7425 | @subsection Starting and Stopping Trace Experiment | |
7426 | ||
7427 | @table @code | |
7428 | @kindex tstart | |
7429 | @cindex start a new trace experiment | |
7430 | @cindex collected data discarded | |
7431 | @item tstart | |
7432 | This command takes no arguments. It starts the trace experiment, and | |
7433 | begins collecting data. This has the side effect of discarding all | |
7434 | the data collected in the trace buffer during the previous trace | |
7435 | experiment. | |
7436 | ||
7437 | @kindex tstop | |
7438 | @cindex stop a running trace experiment | |
7439 | @item tstop | |
7440 | This command takes no arguments. It ends the trace experiment, and | |
7441 | stops collecting data. | |
7442 | ||
68c71a2e | 7443 | @strong{Note}: a trace experiment and data collection may stop |
b37052ae EZ |
7444 | automatically if any tracepoint's passcount is reached |
7445 | (@pxref{Tracepoint Passcounts}), or if the trace buffer becomes full. | |
7446 | ||
7447 | @kindex tstatus | |
7448 | @cindex status of trace data collection | |
7449 | @cindex trace experiment, status of | |
7450 | @item tstatus | |
7451 | This command displays the status of the current trace data | |
7452 | collection. | |
7453 | @end table | |
7454 | ||
7455 | Here is an example of the commands we described so far: | |
7456 | ||
7457 | @smallexample | |
7458 | (@value{GDBP}) @b{trace gdb_c_test} | |
7459 | (@value{GDBP}) @b{actions} | |
7460 | Enter actions for tracepoint #1, one per line. | |
7461 | > collect $regs,$locals,$args | |
7462 | > while-stepping 11 | |
7463 | > collect $regs | |
7464 | > end | |
7465 | > end | |
7466 | (@value{GDBP}) @b{tstart} | |
7467 | [time passes @dots{}] | |
7468 | (@value{GDBP}) @b{tstop} | |
7469 | @end smallexample | |
7470 | ||
7471 | ||
7472 | @node Analyze Collected Data | |
7473 | @section Using the collected data | |
7474 | ||
7475 | After the tracepoint experiment ends, you use @value{GDBN} commands | |
7476 | for examining the trace data. The basic idea is that each tracepoint | |
7477 | collects a trace @dfn{snapshot} every time it is hit and another | |
7478 | snapshot every time it single-steps. All these snapshots are | |
7479 | consecutively numbered from zero and go into a buffer, and you can | |
7480 | examine them later. The way you examine them is to @dfn{focus} on a | |
7481 | specific trace snapshot. When the remote stub is focused on a trace | |
7482 | snapshot, it will respond to all @value{GDBN} requests for memory and | |
7483 | registers by reading from the buffer which belongs to that snapshot, | |
7484 | rather than from @emph{real} memory or registers of the program being | |
7485 | debugged. This means that @strong{all} @value{GDBN} commands | |
7486 | (@code{print}, @code{info registers}, @code{backtrace}, etc.) will | |
7487 | behave as if we were currently debugging the program state as it was | |
7488 | when the tracepoint occurred. Any requests for data that are not in | |
7489 | the buffer will fail. | |
7490 | ||
7491 | @menu | |
7492 | * tfind:: How to select a trace snapshot | |
7493 | * tdump:: How to display all data for a snapshot | |
7494 | * save-tracepoints:: How to save tracepoints for a future run | |
7495 | @end menu | |
7496 | ||
7497 | @node tfind | |
7498 | @subsection @code{tfind @var{n}} | |
7499 | ||
7500 | @kindex tfind | |
7501 | @cindex select trace snapshot | |
7502 | @cindex find trace snapshot | |
7503 | The basic command for selecting a trace snapshot from the buffer is | |
7504 | @code{tfind @var{n}}, which finds trace snapshot number @var{n}, | |
7505 | counting from zero. If no argument @var{n} is given, the next | |
7506 | snapshot is selected. | |
7507 | ||
7508 | Here are the various forms of using the @code{tfind} command. | |
7509 | ||
7510 | @table @code | |
7511 | @item tfind start | |
7512 | Find the first snapshot in the buffer. This is a synonym for | |
7513 | @code{tfind 0} (since 0 is the number of the first snapshot). | |
7514 | ||
7515 | @item tfind none | |
7516 | Stop debugging trace snapshots, resume @emph{live} debugging. | |
7517 | ||
7518 | @item tfind end | |
7519 | Same as @samp{tfind none}. | |
7520 | ||
7521 | @item tfind | |
7522 | No argument means find the next trace snapshot. | |
7523 | ||
7524 | @item tfind - | |
7525 | Find the previous trace snapshot before the current one. This permits | |
7526 | retracing earlier steps. | |
7527 | ||
7528 | @item tfind tracepoint @var{num} | |
7529 | Find the next snapshot associated with tracepoint @var{num}. Search | |
7530 | proceeds forward from the last examined trace snapshot. If no | |
7531 | argument @var{num} is given, it means find the next snapshot collected | |
7532 | for the same tracepoint as the current snapshot. | |
7533 | ||
7534 | @item tfind pc @var{addr} | |
7535 | Find the next snapshot associated with the value @var{addr} of the | |
7536 | program counter. Search proceeds forward from the last examined trace | |
7537 | snapshot. If no argument @var{addr} is given, it means find the next | |
7538 | snapshot with the same value of PC as the current snapshot. | |
7539 | ||
7540 | @item tfind outside @var{addr1}, @var{addr2} | |
7541 | Find the next snapshot whose PC is outside the given range of | |
7542 | addresses. | |
7543 | ||
7544 | @item tfind range @var{addr1}, @var{addr2} | |
7545 | Find the next snapshot whose PC is between @var{addr1} and | |
7546 | @var{addr2}. @c FIXME: Is the range inclusive or exclusive? | |
7547 | ||
7548 | @item tfind line @r{[}@var{file}:@r{]}@var{n} | |
7549 | Find the next snapshot associated with the source line @var{n}. If | |
7550 | the optional argument @var{file} is given, refer to line @var{n} in | |
7551 | that source file. Search proceeds forward from the last examined | |
7552 | trace snapshot. If no argument @var{n} is given, it means find the | |
7553 | next line other than the one currently being examined; thus saying | |
7554 | @code{tfind line} repeatedly can appear to have the same effect as | |
7555 | stepping from line to line in a @emph{live} debugging session. | |
7556 | @end table | |
7557 | ||
7558 | The default arguments for the @code{tfind} commands are specifically | |
7559 | designed to make it easy to scan through the trace buffer. For | |
7560 | instance, @code{tfind} with no argument selects the next trace | |
7561 | snapshot, and @code{tfind -} with no argument selects the previous | |
7562 | trace snapshot. So, by giving one @code{tfind} command, and then | |
7563 | simply hitting @key{RET} repeatedly you can examine all the trace | |
7564 | snapshots in order. Or, by saying @code{tfind -} and then hitting | |
7565 | @key{RET} repeatedly you can examine the snapshots in reverse order. | |
7566 | The @code{tfind line} command with no argument selects the snapshot | |
7567 | for the next source line executed. The @code{tfind pc} command with | |
7568 | no argument selects the next snapshot with the same program counter | |
7569 | (PC) as the current frame. The @code{tfind tracepoint} command with | |
7570 | no argument selects the next trace snapshot collected by the same | |
7571 | tracepoint as the current one. | |
7572 | ||
7573 | In addition to letting you scan through the trace buffer manually, | |
7574 | these commands make it easy to construct @value{GDBN} scripts that | |
7575 | scan through the trace buffer and print out whatever collected data | |
7576 | you are interested in. Thus, if we want to examine the PC, FP, and SP | |
7577 | registers from each trace frame in the buffer, we can say this: | |
7578 | ||
7579 | @smallexample | |
7580 | (@value{GDBP}) @b{tfind start} | |
7581 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
7582 | > printf "Frame %d, PC = %08X, SP = %08X, FP = %08X\n", \ | |
7583 | $trace_frame, $pc, $sp, $fp | |
7584 | > tfind | |
7585 | > end | |
7586 | ||
7587 | Frame 0, PC = 0020DC64, SP = 0030BF3C, FP = 0030BF44 | |
7588 | Frame 1, PC = 0020DC6C, SP = 0030BF38, FP = 0030BF44 | |
7589 | Frame 2, PC = 0020DC70, SP = 0030BF34, FP = 0030BF44 | |
7590 | Frame 3, PC = 0020DC74, SP = 0030BF30, FP = 0030BF44 | |
7591 | Frame 4, PC = 0020DC78, SP = 0030BF2C, FP = 0030BF44 | |
7592 | Frame 5, PC = 0020DC7C, SP = 0030BF28, FP = 0030BF44 | |
7593 | Frame 6, PC = 0020DC80, SP = 0030BF24, FP = 0030BF44 | |
7594 | Frame 7, PC = 0020DC84, SP = 0030BF20, FP = 0030BF44 | |
7595 | Frame 8, PC = 0020DC88, SP = 0030BF1C, FP = 0030BF44 | |
7596 | Frame 9, PC = 0020DC8E, SP = 0030BF18, FP = 0030BF44 | |
7597 | Frame 10, PC = 00203F6C, SP = 0030BE3C, FP = 0030BF14 | |
7598 | @end smallexample | |
7599 | ||
7600 | Or, if we want to examine the variable @code{X} at each source line in | |
7601 | the buffer: | |
7602 | ||
7603 | @smallexample | |
7604 | (@value{GDBP}) @b{tfind start} | |
7605 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
7606 | > printf "Frame %d, X == %d\n", $trace_frame, X | |
7607 | > tfind line | |
7608 | > end | |
7609 | ||
7610 | Frame 0, X = 1 | |
7611 | Frame 7, X = 2 | |
7612 | Frame 13, X = 255 | |
7613 | @end smallexample | |
7614 | ||
7615 | @node tdump | |
7616 | @subsection @code{tdump} | |
7617 | @kindex tdump | |
7618 | @cindex dump all data collected at tracepoint | |
7619 | @cindex tracepoint data, display | |
7620 | ||
7621 | This command takes no arguments. It prints all the data collected at | |
7622 | the current trace snapshot. | |
7623 | ||
7624 | @smallexample | |
7625 | (@value{GDBP}) @b{trace 444} | |
7626 | (@value{GDBP}) @b{actions} | |
7627 | Enter actions for tracepoint #2, one per line: | |
7628 | > collect $regs, $locals, $args, gdb_long_test | |
7629 | > end | |
7630 | ||
7631 | (@value{GDBP}) @b{tstart} | |
7632 | ||
7633 | (@value{GDBP}) @b{tfind line 444} | |
7634 | #0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66) | |
7635 | at gdb_test.c:444 | |
7636 | 444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ) | |
7637 | ||
7638 | (@value{GDBP}) @b{tdump} | |
7639 | Data collected at tracepoint 2, trace frame 1: | |
7640 | d0 0xc4aa0085 -995491707 | |
7641 | d1 0x18 24 | |
7642 | d2 0x80 128 | |
7643 | d3 0x33 51 | |
7644 | d4 0x71aea3d 119204413 | |
7645 | d5 0x22 34 | |
7646 | d6 0xe0 224 | |
7647 | d7 0x380035 3670069 | |
7648 | a0 0x19e24a 1696330 | |
7649 | a1 0x3000668 50333288 | |
7650 | a2 0x100 256 | |
7651 | a3 0x322000 3284992 | |
7652 | a4 0x3000698 50333336 | |
7653 | a5 0x1ad3cc 1758156 | |
7654 | fp 0x30bf3c 0x30bf3c | |
7655 | sp 0x30bf34 0x30bf34 | |
7656 | ps 0x0 0 | |
7657 | pc 0x20b2c8 0x20b2c8 | |
7658 | fpcontrol 0x0 0 | |
7659 | fpstatus 0x0 0 | |
7660 | fpiaddr 0x0 0 | |
7661 | p = 0x20e5b4 "gdb-test" | |
7662 | p1 = (void *) 0x11 | |
7663 | p2 = (void *) 0x22 | |
7664 | p3 = (void *) 0x33 | |
7665 | p4 = (void *) 0x44 | |
7666 | p5 = (void *) 0x55 | |
7667 | p6 = (void *) 0x66 | |
7668 | gdb_long_test = 17 '\021' | |
7669 | ||
7670 | (@value{GDBP}) | |
7671 | @end smallexample | |
7672 | ||
7673 | @node save-tracepoints | |
7674 | @subsection @code{save-tracepoints @var{filename}} | |
7675 | @kindex save-tracepoints | |
7676 | @cindex save tracepoints for future sessions | |
7677 | ||
7678 | This command saves all current tracepoint definitions together with | |
7679 | their actions and passcounts, into a file @file{@var{filename}} | |
7680 | suitable for use in a later debugging session. To read the saved | |
7681 | tracepoint definitions, use the @code{source} command (@pxref{Command | |
7682 | Files}). | |
7683 | ||
7684 | @node Tracepoint Variables | |
7685 | @section Convenience Variables for Tracepoints | |
7686 | @cindex tracepoint variables | |
7687 | @cindex convenience variables for tracepoints | |
7688 | ||
7689 | @table @code | |
7690 | @vindex $trace_frame | |
7691 | @item (int) $trace_frame | |
7692 | The current trace snapshot (a.k.a.@: @dfn{frame}) number, or -1 if no | |
7693 | snapshot is selected. | |
7694 | ||
7695 | @vindex $tracepoint | |
7696 | @item (int) $tracepoint | |
7697 | The tracepoint for the current trace snapshot. | |
7698 | ||
7699 | @vindex $trace_line | |
7700 | @item (int) $trace_line | |
7701 | The line number for the current trace snapshot. | |
7702 | ||
7703 | @vindex $trace_file | |
7704 | @item (char []) $trace_file | |
7705 | The source file for the current trace snapshot. | |
7706 | ||
7707 | @vindex $trace_func | |
7708 | @item (char []) $trace_func | |
7709 | The name of the function containing @code{$tracepoint}. | |
7710 | @end table | |
7711 | ||
7712 | Note: @code{$trace_file} is not suitable for use in @code{printf}, | |
7713 | use @code{output} instead. | |
7714 | ||
7715 | Here's a simple example of using these convenience variables for | |
7716 | stepping through all the trace snapshots and printing some of their | |
7717 | data. | |
7718 | ||
7719 | @smallexample | |
7720 | (@value{GDBP}) @b{tfind start} | |
7721 | ||
7722 | (@value{GDBP}) @b{while $trace_frame != -1} | |
7723 | > output $trace_file | |
7724 | > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint | |
7725 | > tfind | |
7726 | > end | |
7727 | @end smallexample | |
7728 | ||
df0cd8c5 JB |
7729 | @node Overlays |
7730 | @chapter Debugging Programs That Use Overlays | |
7731 | @cindex overlays | |
7732 | ||
7733 | If your program is too large to fit completely in your target system's | |
7734 | memory, you can sometimes use @dfn{overlays} to work around this | |
7735 | problem. @value{GDBN} provides some support for debugging programs that | |
7736 | use overlays. | |
7737 | ||
7738 | @menu | |
7739 | * How Overlays Work:: A general explanation of overlays. | |
7740 | * Overlay Commands:: Managing overlays in @value{GDBN}. | |
7741 | * Automatic Overlay Debugging:: @value{GDBN} can find out which overlays are | |
7742 | mapped by asking the inferior. | |
7743 | * Overlay Sample Program:: A sample program using overlays. | |
7744 | @end menu | |
7745 | ||
7746 | @node How Overlays Work | |
7747 | @section How Overlays Work | |
7748 | @cindex mapped overlays | |
7749 | @cindex unmapped overlays | |
7750 | @cindex load address, overlay's | |
7751 | @cindex mapped address | |
7752 | @cindex overlay area | |
7753 | ||
7754 | Suppose you have a computer whose instruction address space is only 64 | |
7755 | kilobytes long, but which has much more memory which can be accessed by | |
7756 | other means: special instructions, segment registers, or memory | |
7757 | management hardware, for example. Suppose further that you want to | |
7758 | adapt a program which is larger than 64 kilobytes to run on this system. | |
7759 | ||
7760 | One solution is to identify modules of your program which are relatively | |
7761 | independent, and need not call each other directly; call these modules | |
7762 | @dfn{overlays}. Separate the overlays from the main program, and place | |
7763 | their machine code in the larger memory. Place your main program in | |
7764 | instruction memory, but leave at least enough space there to hold the | |
7765 | largest overlay as well. | |
7766 | ||
7767 | Now, to call a function located in an overlay, you must first copy that | |
7768 | overlay's machine code from the large memory into the space set aside | |
7769 | for it in the instruction memory, and then jump to its entry point | |
7770 | there. | |
7771 | ||
c928edc0 AC |
7772 | @c NB: In the below the mapped area's size is greater or equal to the |
7773 | @c size of all overlays. This is intentional to remind the developer | |
7774 | @c that overlays don't necessarily need to be the same size. | |
7775 | ||
474c8240 | 7776 | @smallexample |
df0cd8c5 | 7777 | @group |
c928edc0 AC |
7778 | Data Instruction Larger |
7779 | Address Space Address Space Address Space | |
7780 | +-----------+ +-----------+ +-----------+ | |
7781 | | | | | | | | |
7782 | +-----------+ +-----------+ +-----------+<-- overlay 1 | |
7783 | | program | | main | .----| overlay 1 | load address | |
7784 | | variables | | program | | +-----------+ | |
7785 | | and heap | | | | | | | |
7786 | +-----------+ | | | +-----------+<-- overlay 2 | |
7787 | | | +-----------+ | | | load address | |
7788 | +-----------+ | | | .-| overlay 2 | | |
7789 | | | | | | | | |
7790 | mapped --->+-----------+ | | +-----------+ | |
7791 | address | | | | | | | |
7792 | | overlay | <-' | | | | |
7793 | | area | <---' +-----------+<-- overlay 3 | |
7794 | | | <---. | | load address | |
7795 | +-----------+ `--| overlay 3 | | |
7796 | | | | | | |
7797 | +-----------+ | | | |
7798 | +-----------+ | |
7799 | | | | |
7800 | +-----------+ | |
7801 | ||
7802 | @anchor{A code overlay}A code overlay | |
df0cd8c5 | 7803 | @end group |
474c8240 | 7804 | @end smallexample |
df0cd8c5 | 7805 | |
c928edc0 AC |
7806 | The diagram (@pxref{A code overlay}) shows a system with separate data |
7807 | and instruction address spaces. To map an overlay, the program copies | |
7808 | its code from the larger address space to the instruction address space. | |
7809 | Since the overlays shown here all use the same mapped address, only one | |
7810 | may be mapped at a time. For a system with a single address space for | |
7811 | data and instructions, the diagram would be similar, except that the | |
7812 | program variables and heap would share an address space with the main | |
7813 | program and the overlay area. | |
df0cd8c5 JB |
7814 | |
7815 | An overlay loaded into instruction memory and ready for use is called a | |
7816 | @dfn{mapped} overlay; its @dfn{mapped address} is its address in the | |
7817 | instruction memory. An overlay not present (or only partially present) | |
7818 | in instruction memory is called @dfn{unmapped}; its @dfn{load address} | |
7819 | is its address in the larger memory. The mapped address is also called | |
7820 | the @dfn{virtual memory address}, or @dfn{VMA}; the load address is also | |
7821 | called the @dfn{load memory address}, or @dfn{LMA}. | |
7822 | ||
7823 | Unfortunately, overlays are not a completely transparent way to adapt a | |
7824 | program to limited instruction memory. They introduce a new set of | |
7825 | global constraints you must keep in mind as you design your program: | |
7826 | ||
7827 | @itemize @bullet | |
7828 | ||
7829 | @item | |
7830 | Before calling or returning to a function in an overlay, your program | |
7831 | must make sure that overlay is actually mapped. Otherwise, the call or | |
7832 | return will transfer control to the right address, but in the wrong | |
7833 | overlay, and your program will probably crash. | |
7834 | ||
7835 | @item | |
7836 | If the process of mapping an overlay is expensive on your system, you | |
7837 | will need to choose your overlays carefully to minimize their effect on | |
7838 | your program's performance. | |
7839 | ||
7840 | @item | |
7841 | The executable file you load onto your system must contain each | |
7842 | overlay's instructions, appearing at the overlay's load address, not its | |
7843 | mapped address. However, each overlay's instructions must be relocated | |
7844 | and its symbols defined as if the overlay were at its mapped address. | |
7845 | You can use GNU linker scripts to specify different load and relocation | |
7846 | addresses for pieces of your program; see @ref{Overlay Description,,, | |
7847 | ld.info, Using ld: the GNU linker}. | |
7848 | ||
7849 | @item | |
7850 | The procedure for loading executable files onto your system must be able | |
7851 | to load their contents into the larger address space as well as the | |
7852 | instruction and data spaces. | |
7853 | ||
7854 | @end itemize | |
7855 | ||
7856 | The overlay system described above is rather simple, and could be | |
7857 | improved in many ways: | |
7858 | ||
7859 | @itemize @bullet | |
7860 | ||
7861 | @item | |
7862 | If your system has suitable bank switch registers or memory management | |
7863 | hardware, you could use those facilities to make an overlay's load area | |
7864 | contents simply appear at their mapped address in instruction space. | |
7865 | This would probably be faster than copying the overlay to its mapped | |
7866 | area in the usual way. | |
7867 | ||
7868 | @item | |
7869 | If your overlays are small enough, you could set aside more than one | |
7870 | overlay area, and have more than one overlay mapped at a time. | |
7871 | ||
7872 | @item | |
7873 | You can use overlays to manage data, as well as instructions. In | |
7874 | general, data overlays are even less transparent to your design than | |
7875 | code overlays: whereas code overlays only require care when you call or | |
7876 | return to functions, data overlays require care every time you access | |
7877 | the data. Also, if you change the contents of a data overlay, you | |
7878 | must copy its contents back out to its load address before you can copy a | |
7879 | different data overlay into the same mapped area. | |
7880 | ||
7881 | @end itemize | |
7882 | ||
7883 | ||
7884 | @node Overlay Commands | |
7885 | @section Overlay Commands | |
7886 | ||
7887 | To use @value{GDBN}'s overlay support, each overlay in your program must | |
7888 | correspond to a separate section of the executable file. The section's | |
7889 | virtual memory address and load memory address must be the overlay's | |
7890 | mapped and load addresses. Identifying overlays with sections allows | |
7891 | @value{GDBN} to determine the appropriate address of a function or | |
7892 | variable, depending on whether the overlay is mapped or not. | |
7893 | ||
7894 | @value{GDBN}'s overlay commands all start with the word @code{overlay}; | |
7895 | you can abbreviate this as @code{ov} or @code{ovly}. The commands are: | |
7896 | ||
7897 | @table @code | |
7898 | @item overlay off | |
4644b6e3 | 7899 | @kindex overlay |
df0cd8c5 JB |
7900 | Disable @value{GDBN}'s overlay support. When overlay support is |
7901 | disabled, @value{GDBN} assumes that all functions and variables are | |
7902 | always present at their mapped addresses. By default, @value{GDBN}'s | |
7903 | overlay support is disabled. | |
7904 | ||
7905 | @item overlay manual | |
df0cd8c5 JB |
7906 | @cindex manual overlay debugging |
7907 | Enable @dfn{manual} overlay debugging. In this mode, @value{GDBN} | |
7908 | relies on you to tell it which overlays are mapped, and which are not, | |
7909 | using the @code{overlay map-overlay} and @code{overlay unmap-overlay} | |
7910 | commands described below. | |
7911 | ||
7912 | @item overlay map-overlay @var{overlay} | |
7913 | @itemx overlay map @var{overlay} | |
df0cd8c5 JB |
7914 | @cindex map an overlay |
7915 | Tell @value{GDBN} that @var{overlay} is now mapped; @var{overlay} must | |
7916 | be the name of the object file section containing the overlay. When an | |
7917 | overlay is mapped, @value{GDBN} assumes it can find the overlay's | |
7918 | functions and variables at their mapped addresses. @value{GDBN} assumes | |
7919 | that any other overlays whose mapped ranges overlap that of | |
7920 | @var{overlay} are now unmapped. | |
7921 | ||
7922 | @item overlay unmap-overlay @var{overlay} | |
7923 | @itemx overlay unmap @var{overlay} | |
df0cd8c5 JB |
7924 | @cindex unmap an overlay |
7925 | Tell @value{GDBN} that @var{overlay} is no longer mapped; @var{overlay} | |
7926 | must be the name of the object file section containing the overlay. | |
7927 | When an overlay is unmapped, @value{GDBN} assumes it can find the | |
7928 | overlay's functions and variables at their load addresses. | |
7929 | ||
7930 | @item overlay auto | |
df0cd8c5 JB |
7931 | Enable @dfn{automatic} overlay debugging. In this mode, @value{GDBN} |
7932 | consults a data structure the overlay manager maintains in the inferior | |
7933 | to see which overlays are mapped. For details, see @ref{Automatic | |
7934 | Overlay Debugging}. | |
7935 | ||
7936 | @item overlay load-target | |
7937 | @itemx overlay load | |
df0cd8c5 JB |
7938 | @cindex reloading the overlay table |
7939 | Re-read the overlay table from the inferior. Normally, @value{GDBN} | |
7940 | re-reads the table @value{GDBN} automatically each time the inferior | |
7941 | stops, so this command should only be necessary if you have changed the | |
7942 | overlay mapping yourself using @value{GDBN}. This command is only | |
7943 | useful when using automatic overlay debugging. | |
7944 | ||
7945 | @item overlay list-overlays | |
7946 | @itemx overlay list | |
7947 | @cindex listing mapped overlays | |
7948 | Display a list of the overlays currently mapped, along with their mapped | |
7949 | addresses, load addresses, and sizes. | |
7950 | ||
7951 | @end table | |
7952 | ||
7953 | Normally, when @value{GDBN} prints a code address, it includes the name | |
7954 | of the function the address falls in: | |
7955 | ||
474c8240 | 7956 | @smallexample |
f7dc1244 | 7957 | (@value{GDBP}) print main |
df0cd8c5 | 7958 | $3 = @{int ()@} 0x11a0 <main> |
474c8240 | 7959 | @end smallexample |
df0cd8c5 JB |
7960 | @noindent |
7961 | When overlay debugging is enabled, @value{GDBN} recognizes code in | |
7962 | unmapped overlays, and prints the names of unmapped functions with | |
7963 | asterisks around them. For example, if @code{foo} is a function in an | |
7964 | unmapped overlay, @value{GDBN} prints it this way: | |
7965 | ||
474c8240 | 7966 | @smallexample |
f7dc1244 | 7967 | (@value{GDBP}) overlay list |
df0cd8c5 | 7968 | No sections are mapped. |
f7dc1244 | 7969 | (@value{GDBP}) print foo |
df0cd8c5 | 7970 | $5 = @{int (int)@} 0x100000 <*foo*> |
474c8240 | 7971 | @end smallexample |
df0cd8c5 JB |
7972 | @noindent |
7973 | When @code{foo}'s overlay is mapped, @value{GDBN} prints the function's | |
7974 | name normally: | |
7975 | ||
474c8240 | 7976 | @smallexample |
f7dc1244 | 7977 | (@value{GDBP}) overlay list |
b383017d | 7978 | Section .ov.foo.text, loaded at 0x100000 - 0x100034, |
df0cd8c5 | 7979 | mapped at 0x1016 - 0x104a |
f7dc1244 | 7980 | (@value{GDBP}) print foo |
df0cd8c5 | 7981 | $6 = @{int (int)@} 0x1016 <foo> |
474c8240 | 7982 | @end smallexample |
df0cd8c5 JB |
7983 | |
7984 | When overlay debugging is enabled, @value{GDBN} can find the correct | |
7985 | address for functions and variables in an overlay, whether or not the | |
7986 | overlay is mapped. This allows most @value{GDBN} commands, like | |
7987 | @code{break} and @code{disassemble}, to work normally, even on unmapped | |
7988 | code. However, @value{GDBN}'s breakpoint support has some limitations: | |
7989 | ||
7990 | @itemize @bullet | |
7991 | @item | |
7992 | @cindex breakpoints in overlays | |
7993 | @cindex overlays, setting breakpoints in | |
7994 | You can set breakpoints in functions in unmapped overlays, as long as | |
7995 | @value{GDBN} can write to the overlay at its load address. | |
7996 | @item | |
7997 | @value{GDBN} can not set hardware or simulator-based breakpoints in | |
7998 | unmapped overlays. However, if you set a breakpoint at the end of your | |
7999 | overlay manager (and tell @value{GDBN} which overlays are now mapped, if | |
8000 | you are using manual overlay management), @value{GDBN} will re-set its | |
8001 | breakpoints properly. | |
8002 | @end itemize | |
8003 | ||
8004 | ||
8005 | @node Automatic Overlay Debugging | |
8006 | @section Automatic Overlay Debugging | |
8007 | @cindex automatic overlay debugging | |
8008 | ||
8009 | @value{GDBN} can automatically track which overlays are mapped and which | |
8010 | are not, given some simple co-operation from the overlay manager in the | |
8011 | inferior. If you enable automatic overlay debugging with the | |
8012 | @code{overlay auto} command (@pxref{Overlay Commands}), @value{GDBN} | |
8013 | looks in the inferior's memory for certain variables describing the | |
8014 | current state of the overlays. | |
8015 | ||
8016 | Here are the variables your overlay manager must define to support | |
8017 | @value{GDBN}'s automatic overlay debugging: | |
8018 | ||
8019 | @table @asis | |
8020 | ||
8021 | @item @code{_ovly_table}: | |
8022 | This variable must be an array of the following structures: | |
8023 | ||
474c8240 | 8024 | @smallexample |
df0cd8c5 JB |
8025 | struct |
8026 | @{ | |
8027 | /* The overlay's mapped address. */ | |
8028 | unsigned long vma; | |
8029 | ||
8030 | /* The size of the overlay, in bytes. */ | |
8031 | unsigned long size; | |
8032 | ||
8033 | /* The overlay's load address. */ | |
8034 | unsigned long lma; | |
8035 | ||
8036 | /* Non-zero if the overlay is currently mapped; | |
8037 | zero otherwise. */ | |
8038 | unsigned long mapped; | |
8039 | @} | |
474c8240 | 8040 | @end smallexample |
df0cd8c5 JB |
8041 | |
8042 | @item @code{_novlys}: | |
8043 | This variable must be a four-byte signed integer, holding the total | |
8044 | number of elements in @code{_ovly_table}. | |
8045 | ||
8046 | @end table | |
8047 | ||
8048 | To decide whether a particular overlay is mapped or not, @value{GDBN} | |
8049 | looks for an entry in @w{@code{_ovly_table}} whose @code{vma} and | |
8050 | @code{lma} members equal the VMA and LMA of the overlay's section in the | |
8051 | executable file. When @value{GDBN} finds a matching entry, it consults | |
8052 | the entry's @code{mapped} member to determine whether the overlay is | |
8053 | currently mapped. | |
8054 | ||
81d46470 | 8055 | In addition, your overlay manager may define a function called |
def71bfa | 8056 | @code{_ovly_debug_event}. If this function is defined, @value{GDBN} |
81d46470 MS |
8057 | will silently set a breakpoint there. If the overlay manager then |
8058 | calls this function whenever it has changed the overlay table, this | |
8059 | will enable @value{GDBN} to accurately keep track of which overlays | |
8060 | are in program memory, and update any breakpoints that may be set | |
b383017d | 8061 | in overlays. This will allow breakpoints to work even if the |
81d46470 MS |
8062 | overlays are kept in ROM or other non-writable memory while they |
8063 | are not being executed. | |
df0cd8c5 JB |
8064 | |
8065 | @node Overlay Sample Program | |
8066 | @section Overlay Sample Program | |
8067 | @cindex overlay example program | |
8068 | ||
8069 | When linking a program which uses overlays, you must place the overlays | |
8070 | at their load addresses, while relocating them to run at their mapped | |
8071 | addresses. To do this, you must write a linker script (@pxref{Overlay | |
8072 | Description,,, ld.info, Using ld: the GNU linker}). Unfortunately, | |
8073 | since linker scripts are specific to a particular host system, target | |
8074 | architecture, and target memory layout, this manual cannot provide | |
8075 | portable sample code demonstrating @value{GDBN}'s overlay support. | |
8076 | ||
8077 | However, the @value{GDBN} source distribution does contain an overlaid | |
8078 | program, with linker scripts for a few systems, as part of its test | |
8079 | suite. The program consists of the following files from | |
8080 | @file{gdb/testsuite/gdb.base}: | |
8081 | ||
8082 | @table @file | |
8083 | @item overlays.c | |
8084 | The main program file. | |
8085 | @item ovlymgr.c | |
8086 | A simple overlay manager, used by @file{overlays.c}. | |
8087 | @item foo.c | |
8088 | @itemx bar.c | |
8089 | @itemx baz.c | |
8090 | @itemx grbx.c | |
8091 | Overlay modules, loaded and used by @file{overlays.c}. | |
8092 | @item d10v.ld | |
8093 | @itemx m32r.ld | |
8094 | Linker scripts for linking the test program on the @code{d10v-elf} | |
8095 | and @code{m32r-elf} targets. | |
8096 | @end table | |
8097 | ||
8098 | You can build the test program using the @code{d10v-elf} GCC | |
8099 | cross-compiler like this: | |
8100 | ||
474c8240 | 8101 | @smallexample |
df0cd8c5 JB |
8102 | $ d10v-elf-gcc -g -c overlays.c |
8103 | $ d10v-elf-gcc -g -c ovlymgr.c | |
8104 | $ d10v-elf-gcc -g -c foo.c | |
8105 | $ d10v-elf-gcc -g -c bar.c | |
8106 | $ d10v-elf-gcc -g -c baz.c | |
8107 | $ d10v-elf-gcc -g -c grbx.c | |
8108 | $ d10v-elf-gcc -g overlays.o ovlymgr.o foo.o bar.o \ | |
8109 | baz.o grbx.o -Wl,-Td10v.ld -o overlays | |
474c8240 | 8110 | @end smallexample |
df0cd8c5 JB |
8111 | |
8112 | The build process is identical for any other architecture, except that | |
8113 | you must substitute the appropriate compiler and linker script for the | |
8114 | target system for @code{d10v-elf-gcc} and @code{d10v.ld}. | |
8115 | ||
8116 | ||
6d2ebf8b | 8117 | @node Languages |
c906108c SS |
8118 | @chapter Using @value{GDBN} with Different Languages |
8119 | @cindex languages | |
8120 | ||
c906108c SS |
8121 | Although programming languages generally have common aspects, they are |
8122 | rarely expressed in the same manner. For instance, in ANSI C, | |
8123 | dereferencing a pointer @code{p} is accomplished by @code{*p}, but in | |
8124 | Modula-2, it is accomplished by @code{p^}. Values can also be | |
5d161b24 | 8125 | represented (and displayed) differently. Hex numbers in C appear as |
c906108c | 8126 | @samp{0x1ae}, while in Modula-2 they appear as @samp{1AEH}. |
c906108c SS |
8127 | |
8128 | @cindex working language | |
8129 | Language-specific information is built into @value{GDBN} for some languages, | |
8130 | allowing you to express operations like the above in your program's | |
8131 | native language, and allowing @value{GDBN} to output values in a manner | |
8132 | consistent with the syntax of your program's native language. The | |
8133 | language you use to build expressions is called the @dfn{working | |
8134 | language}. | |
8135 | ||
8136 | @menu | |
8137 | * Setting:: Switching between source languages | |
8138 | * Show:: Displaying the language | |
c906108c | 8139 | * Checks:: Type and range checks |
9c16f35a | 8140 | * Supported languages:: Supported languages |
4e562065 | 8141 | * Unsupported languages:: Unsupported languages |
c906108c SS |
8142 | @end menu |
8143 | ||
6d2ebf8b | 8144 | @node Setting |
c906108c SS |
8145 | @section Switching between source languages |
8146 | ||
8147 | There are two ways to control the working language---either have @value{GDBN} | |
8148 | set it automatically, or select it manually yourself. You can use the | |
8149 | @code{set language} command for either purpose. On startup, @value{GDBN} | |
8150 | defaults to setting the language automatically. The working language is | |
8151 | used to determine how expressions you type are interpreted, how values | |
8152 | are printed, etc. | |
8153 | ||
8154 | In addition to the working language, every source file that | |
8155 | @value{GDBN} knows about has its own working language. For some object | |
8156 | file formats, the compiler might indicate which language a particular | |
8157 | source file is in. However, most of the time @value{GDBN} infers the | |
8158 | language from the name of the file. The language of a source file | |
b37052ae | 8159 | controls whether C@t{++} names are demangled---this way @code{backtrace} can |
c906108c | 8160 | show each frame appropriately for its own language. There is no way to |
d4f3574e SS |
8161 | set the language of a source file from within @value{GDBN}, but you can |
8162 | set the language associated with a filename extension. @xref{Show, , | |
8163 | Displaying the language}. | |
c906108c SS |
8164 | |
8165 | This is most commonly a problem when you use a program, such | |
5d161b24 | 8166 | as @code{cfront} or @code{f2c}, that generates C but is written in |
c906108c SS |
8167 | another language. In that case, make the |
8168 | program use @code{#line} directives in its C output; that way | |
8169 | @value{GDBN} will know the correct language of the source code of the original | |
8170 | program, and will display that source code, not the generated C code. | |
8171 | ||
8172 | @menu | |
8173 | * Filenames:: Filename extensions and languages. | |
8174 | * Manually:: Setting the working language manually | |
8175 | * Automatically:: Having @value{GDBN} infer the source language | |
8176 | @end menu | |
8177 | ||
6d2ebf8b | 8178 | @node Filenames |
c906108c SS |
8179 | @subsection List of filename extensions and languages |
8180 | ||
8181 | If a source file name ends in one of the following extensions, then | |
8182 | @value{GDBN} infers that its language is the one indicated. | |
8183 | ||
8184 | @table @file | |
e07c999f PH |
8185 | @item .ada |
8186 | @itemx .ads | |
8187 | @itemx .adb | |
8188 | @itemx .a | |
8189 | Ada source file. | |
c906108c SS |
8190 | |
8191 | @item .c | |
8192 | C source file | |
8193 | ||
8194 | @item .C | |
8195 | @itemx .cc | |
8196 | @itemx .cp | |
8197 | @itemx .cpp | |
8198 | @itemx .cxx | |
8199 | @itemx .c++ | |
b37052ae | 8200 | C@t{++} source file |
c906108c | 8201 | |
b37303ee AF |
8202 | @item .m |
8203 | Objective-C source file | |
8204 | ||
c906108c SS |
8205 | @item .f |
8206 | @itemx .F | |
8207 | Fortran source file | |
8208 | ||
c906108c SS |
8209 | @item .mod |
8210 | Modula-2 source file | |
c906108c SS |
8211 | |
8212 | @item .s | |
8213 | @itemx .S | |
8214 | Assembler source file. This actually behaves almost like C, but | |
8215 | @value{GDBN} does not skip over function prologues when stepping. | |
8216 | @end table | |
8217 | ||
8218 | In addition, you may set the language associated with a filename | |
8219 | extension. @xref{Show, , Displaying the language}. | |
8220 | ||
6d2ebf8b | 8221 | @node Manually |
c906108c SS |
8222 | @subsection Setting the working language |
8223 | ||
8224 | If you allow @value{GDBN} to set the language automatically, | |
8225 | expressions are interpreted the same way in your debugging session and | |
8226 | your program. | |
8227 | ||
8228 | @kindex set language | |
8229 | If you wish, you may set the language manually. To do this, issue the | |
8230 | command @samp{set language @var{lang}}, where @var{lang} is the name of | |
5d161b24 | 8231 | a language, such as |
c906108c | 8232 | @code{c} or @code{modula-2}. |
c906108c SS |
8233 | For a list of the supported languages, type @samp{set language}. |
8234 | ||
c906108c SS |
8235 | Setting the language manually prevents @value{GDBN} from updating the working |
8236 | language automatically. This can lead to confusion if you try | |
8237 | to debug a program when the working language is not the same as the | |
8238 | source language, when an expression is acceptable to both | |
8239 | languages---but means different things. For instance, if the current | |
8240 | source file were written in C, and @value{GDBN} was parsing Modula-2, a | |
8241 | command such as: | |
8242 | ||
474c8240 | 8243 | @smallexample |
c906108c | 8244 | print a = b + c |
474c8240 | 8245 | @end smallexample |
c906108c SS |
8246 | |
8247 | @noindent | |
8248 | might not have the effect you intended. In C, this means to add | |
8249 | @code{b} and @code{c} and place the result in @code{a}. The result | |
8250 | printed would be the value of @code{a}. In Modula-2, this means to compare | |
8251 | @code{a} to the result of @code{b+c}, yielding a @code{BOOLEAN} value. | |
c906108c | 8252 | |
6d2ebf8b | 8253 | @node Automatically |
c906108c SS |
8254 | @subsection Having @value{GDBN} infer the source language |
8255 | ||
8256 | To have @value{GDBN} set the working language automatically, use | |
8257 | @samp{set language local} or @samp{set language auto}. @value{GDBN} | |
8258 | then infers the working language. That is, when your program stops in a | |
8259 | frame (usually by encountering a breakpoint), @value{GDBN} sets the | |
8260 | working language to the language recorded for the function in that | |
8261 | frame. If the language for a frame is unknown (that is, if the function | |
8262 | or block corresponding to the frame was defined in a source file that | |
8263 | does not have a recognized extension), the current working language is | |
8264 | not changed, and @value{GDBN} issues a warning. | |
8265 | ||
8266 | This may not seem necessary for most programs, which are written | |
8267 | entirely in one source language. However, program modules and libraries | |
8268 | written in one source language can be used by a main program written in | |
8269 | a different source language. Using @samp{set language auto} in this | |
8270 | case frees you from having to set the working language manually. | |
8271 | ||
6d2ebf8b | 8272 | @node Show |
c906108c | 8273 | @section Displaying the language |
c906108c SS |
8274 | |
8275 | The following commands help you find out which language is the | |
8276 | working language, and also what language source files were written in. | |
8277 | ||
c906108c SS |
8278 | @table @code |
8279 | @item show language | |
9c16f35a | 8280 | @kindex show language |
c906108c SS |
8281 | Display the current working language. This is the |
8282 | language you can use with commands such as @code{print} to | |
8283 | build and compute expressions that may involve variables in your program. | |
8284 | ||
8285 | @item info frame | |
4644b6e3 | 8286 | @kindex info frame@r{, show the source language} |
5d161b24 | 8287 | Display the source language for this frame. This language becomes the |
c906108c | 8288 | working language if you use an identifier from this frame. |
5d161b24 | 8289 | @xref{Frame Info, ,Information about a frame}, to identify the other |
c906108c SS |
8290 | information listed here. |
8291 | ||
8292 | @item info source | |
4644b6e3 | 8293 | @kindex info source@r{, show the source language} |
c906108c | 8294 | Display the source language of this source file. |
5d161b24 | 8295 | @xref{Symbols, ,Examining the Symbol Table}, to identify the other |
c906108c SS |
8296 | information listed here. |
8297 | @end table | |
8298 | ||
8299 | In unusual circumstances, you may have source files with extensions | |
8300 | not in the standard list. You can then set the extension associated | |
8301 | with a language explicitly: | |
8302 | ||
c906108c | 8303 | @table @code |
09d4efe1 | 8304 | @item set extension-language @var{ext} @var{language} |
9c16f35a | 8305 | @kindex set extension-language |
09d4efe1 EZ |
8306 | Tell @value{GDBN} that source files with extension @var{ext} are to be |
8307 | assumed as written in the source language @var{language}. | |
c906108c SS |
8308 | |
8309 | @item info extensions | |
9c16f35a | 8310 | @kindex info extensions |
c906108c SS |
8311 | List all the filename extensions and the associated languages. |
8312 | @end table | |
8313 | ||
6d2ebf8b | 8314 | @node Checks |
c906108c SS |
8315 | @section Type and range checking |
8316 | ||
8317 | @quotation | |
8318 | @emph{Warning:} In this release, the @value{GDBN} commands for type and range | |
8319 | checking are included, but they do not yet have any effect. This | |
8320 | section documents the intended facilities. | |
8321 | @end quotation | |
8322 | @c FIXME remove warning when type/range code added | |
8323 | ||
8324 | Some languages are designed to guard you against making seemingly common | |
8325 | errors through a series of compile- and run-time checks. These include | |
8326 | checking the type of arguments to functions and operators, and making | |
8327 | sure mathematical overflows are caught at run time. Checks such as | |
8328 | these help to ensure a program's correctness once it has been compiled | |
8329 | by eliminating type mismatches, and providing active checks for range | |
8330 | errors when your program is running. | |
8331 | ||
8332 | @value{GDBN} can check for conditions like the above if you wish. | |
9c16f35a EZ |
8333 | Although @value{GDBN} does not check the statements in your program, |
8334 | it can check expressions entered directly into @value{GDBN} for | |
8335 | evaluation via the @code{print} command, for example. As with the | |
8336 | working language, @value{GDBN} can also decide whether or not to check | |
8337 | automatically based on your program's source language. | |
8338 | @xref{Supported languages, ,Supported languages}, for the default | |
8339 | settings of supported languages. | |
c906108c SS |
8340 | |
8341 | @menu | |
8342 | * Type Checking:: An overview of type checking | |
8343 | * Range Checking:: An overview of range checking | |
8344 | @end menu | |
8345 | ||
8346 | @cindex type checking | |
8347 | @cindex checks, type | |
6d2ebf8b | 8348 | @node Type Checking |
c906108c SS |
8349 | @subsection An overview of type checking |
8350 | ||
8351 | Some languages, such as Modula-2, are strongly typed, meaning that the | |
8352 | arguments to operators and functions have to be of the correct type, | |
8353 | otherwise an error occurs. These checks prevent type mismatch | |
8354 | errors from ever causing any run-time problems. For example, | |
8355 | ||
8356 | @smallexample | |
8357 | 1 + 2 @result{} 3 | |
8358 | @exdent but | |
8359 | @error{} 1 + 2.3 | |
8360 | @end smallexample | |
8361 | ||
8362 | The second example fails because the @code{CARDINAL} 1 is not | |
8363 | type-compatible with the @code{REAL} 2.3. | |
8364 | ||
5d161b24 DB |
8365 | For the expressions you use in @value{GDBN} commands, you can tell the |
8366 | @value{GDBN} type checker to skip checking; | |
8367 | to treat any mismatches as errors and abandon the expression; | |
8368 | or to only issue warnings when type mismatches occur, | |
c906108c SS |
8369 | but evaluate the expression anyway. When you choose the last of |
8370 | these, @value{GDBN} evaluates expressions like the second example above, but | |
8371 | also issues a warning. | |
8372 | ||
5d161b24 DB |
8373 | Even if you turn type checking off, there may be other reasons |
8374 | related to type that prevent @value{GDBN} from evaluating an expression. | |
8375 | For instance, @value{GDBN} does not know how to add an @code{int} and | |
8376 | a @code{struct foo}. These particular type errors have nothing to do | |
8377 | with the language in use, and usually arise from expressions, such as | |
c906108c SS |
8378 | the one described above, which make little sense to evaluate anyway. |
8379 | ||
8380 | Each language defines to what degree it is strict about type. For | |
8381 | instance, both Modula-2 and C require the arguments to arithmetical | |
8382 | operators to be numbers. In C, enumerated types and pointers can be | |
8383 | represented as numbers, so that they are valid arguments to mathematical | |
9c16f35a | 8384 | operators. @xref{Supported languages, ,Supported languages}, for further |
c906108c SS |
8385 | details on specific languages. |
8386 | ||
8387 | @value{GDBN} provides some additional commands for controlling the type checker: | |
8388 | ||
c906108c SS |
8389 | @kindex set check type |
8390 | @kindex show check type | |
8391 | @table @code | |
8392 | @item set check type auto | |
8393 | Set type checking on or off based on the current working language. | |
9c16f35a | 8394 | @xref{Supported languages, ,Supported languages}, for the default settings for |
c906108c SS |
8395 | each language. |
8396 | ||
8397 | @item set check type on | |
8398 | @itemx set check type off | |
8399 | Set type checking on or off, overriding the default setting for the | |
8400 | current working language. Issue a warning if the setting does not | |
8401 | match the language default. If any type mismatches occur in | |
d4f3574e | 8402 | evaluating an expression while type checking is on, @value{GDBN} prints a |
c906108c SS |
8403 | message and aborts evaluation of the expression. |
8404 | ||
8405 | @item set check type warn | |
8406 | Cause the type checker to issue warnings, but to always attempt to | |
8407 | evaluate the expression. Evaluating the expression may still | |
8408 | be impossible for other reasons. For example, @value{GDBN} cannot add | |
8409 | numbers and structures. | |
8410 | ||
8411 | @item show type | |
5d161b24 | 8412 | Show the current setting of the type checker, and whether or not @value{GDBN} |
c906108c SS |
8413 | is setting it automatically. |
8414 | @end table | |
8415 | ||
8416 | @cindex range checking | |
8417 | @cindex checks, range | |
6d2ebf8b | 8418 | @node Range Checking |
c906108c SS |
8419 | @subsection An overview of range checking |
8420 | ||
8421 | In some languages (such as Modula-2), it is an error to exceed the | |
8422 | bounds of a type; this is enforced with run-time checks. Such range | |
8423 | checking is meant to ensure program correctness by making sure | |
8424 | computations do not overflow, or indices on an array element access do | |
8425 | not exceed the bounds of the array. | |
8426 | ||
8427 | For expressions you use in @value{GDBN} commands, you can tell | |
8428 | @value{GDBN} to treat range errors in one of three ways: ignore them, | |
8429 | always treat them as errors and abandon the expression, or issue | |
8430 | warnings but evaluate the expression anyway. | |
8431 | ||
8432 | A range error can result from numerical overflow, from exceeding an | |
8433 | array index bound, or when you type a constant that is not a member | |
8434 | of any type. Some languages, however, do not treat overflows as an | |
8435 | error. In many implementations of C, mathematical overflow causes the | |
8436 | result to ``wrap around'' to lower values---for example, if @var{m} is | |
8437 | the largest integer value, and @var{s} is the smallest, then | |
8438 | ||
474c8240 | 8439 | @smallexample |
c906108c | 8440 | @var{m} + 1 @result{} @var{s} |
474c8240 | 8441 | @end smallexample |
c906108c SS |
8442 | |
8443 | This, too, is specific to individual languages, and in some cases | |
9c16f35a | 8444 | specific to individual compilers or machines. @xref{Supported languages, , |
c906108c SS |
8445 | Supported languages}, for further details on specific languages. |
8446 | ||
8447 | @value{GDBN} provides some additional commands for controlling the range checker: | |
8448 | ||
c906108c SS |
8449 | @kindex set check range |
8450 | @kindex show check range | |
8451 | @table @code | |
8452 | @item set check range auto | |
8453 | Set range checking on or off based on the current working language. | |
9c16f35a | 8454 | @xref{Supported languages, ,Supported languages}, for the default settings for |
c906108c SS |
8455 | each language. |
8456 | ||
8457 | @item set check range on | |
8458 | @itemx set check range off | |
8459 | Set range checking on or off, overriding the default setting for the | |
8460 | current working language. A warning is issued if the setting does not | |
c3f6f71d JM |
8461 | match the language default. If a range error occurs and range checking is on, |
8462 | then a message is printed and evaluation of the expression is aborted. | |
c906108c SS |
8463 | |
8464 | @item set check range warn | |
8465 | Output messages when the @value{GDBN} range checker detects a range error, | |
8466 | but attempt to evaluate the expression anyway. Evaluating the | |
8467 | expression may still be impossible for other reasons, such as accessing | |
8468 | memory that the process does not own (a typical example from many Unix | |
8469 | systems). | |
8470 | ||
8471 | @item show range | |
8472 | Show the current setting of the range checker, and whether or not it is | |
8473 | being set automatically by @value{GDBN}. | |
8474 | @end table | |
c906108c | 8475 | |
9c16f35a | 8476 | @node Supported languages |
c906108c | 8477 | @section Supported languages |
c906108c | 8478 | |
9c16f35a EZ |
8479 | @value{GDBN} supports C, C@t{++}, Objective-C, Fortran, Java, Pascal, |
8480 | assembly, Modula-2, and Ada. | |
cce74817 | 8481 | @c This is false ... |
c906108c SS |
8482 | Some @value{GDBN} features may be used in expressions regardless of the |
8483 | language you use: the @value{GDBN} @code{@@} and @code{::} operators, | |
8484 | and the @samp{@{type@}addr} construct (@pxref{Expressions, | |
8485 | ,Expressions}) can be used with the constructs of any supported | |
8486 | language. | |
8487 | ||
8488 | The following sections detail to what degree each source language is | |
8489 | supported by @value{GDBN}. These sections are not meant to be language | |
8490 | tutorials or references, but serve only as a reference guide to what the | |
8491 | @value{GDBN} expression parser accepts, and what input and output | |
8492 | formats should look like for different languages. There are many good | |
8493 | books written on each of these languages; please look to these for a | |
8494 | language reference or tutorial. | |
8495 | ||
c906108c | 8496 | @menu |
b37303ee | 8497 | * C:: C and C@t{++} |
b383017d | 8498 | * Objective-C:: Objective-C |
09d4efe1 | 8499 | * Fortran:: Fortran |
9c16f35a | 8500 | * Pascal:: Pascal |
b37303ee | 8501 | * Modula-2:: Modula-2 |
e07c999f | 8502 | * Ada:: Ada |
c906108c SS |
8503 | @end menu |
8504 | ||
6d2ebf8b | 8505 | @node C |
b37052ae | 8506 | @subsection C and C@t{++} |
7a292a7a | 8507 | |
b37052ae EZ |
8508 | @cindex C and C@t{++} |
8509 | @cindex expressions in C or C@t{++} | |
c906108c | 8510 | |
b37052ae | 8511 | Since C and C@t{++} are so closely related, many features of @value{GDBN} apply |
c906108c SS |
8512 | to both languages. Whenever this is the case, we discuss those languages |
8513 | together. | |
8514 | ||
41afff9a EZ |
8515 | @cindex C@t{++} |
8516 | @cindex @code{g++}, @sc{gnu} C@t{++} compiler | |
b37052ae EZ |
8517 | @cindex @sc{gnu} C@t{++} |
8518 | The C@t{++} debugging facilities are jointly implemented by the C@t{++} | |
8519 | compiler and @value{GDBN}. Therefore, to debug your C@t{++} code | |
8520 | effectively, you must compile your C@t{++} programs with a supported | |
8521 | C@t{++} compiler, such as @sc{gnu} @code{g++}, or the HP ANSI C@t{++} | |
c906108c SS |
8522 | compiler (@code{aCC}). |
8523 | ||
0179ffac DC |
8524 | For best results when using @sc{gnu} C@t{++}, use the DWARF 2 debugging |
8525 | format; if it doesn't work on your system, try the stabs+ debugging | |
8526 | format. You can select those formats explicitly with the @code{g++} | |
8527 | command-line options @option{-gdwarf-2} and @option{-gstabs+}. | |
8528 | @xref{Debugging Options,,Options for Debugging Your Program or @sc{gnu} | |
8529 | CC, gcc.info, Using @sc{gnu} CC}. | |
c906108c | 8530 | |
c906108c | 8531 | @menu |
b37052ae EZ |
8532 | * C Operators:: C and C@t{++} operators |
8533 | * C Constants:: C and C@t{++} constants | |
8534 | * C plus plus expressions:: C@t{++} expressions | |
8535 | * C Defaults:: Default settings for C and C@t{++} | |
8536 | * C Checks:: C and C@t{++} type and range checks | |
c906108c | 8537 | * Debugging C:: @value{GDBN} and C |
b37052ae | 8538 | * Debugging C plus plus:: @value{GDBN} features for C@t{++} |
c906108c | 8539 | @end menu |
c906108c | 8540 | |
6d2ebf8b | 8541 | @node C Operators |
b37052ae | 8542 | @subsubsection C and C@t{++} operators |
7a292a7a | 8543 | |
b37052ae | 8544 | @cindex C and C@t{++} operators |
c906108c SS |
8545 | |
8546 | Operators must be defined on values of specific types. For instance, | |
8547 | @code{+} is defined on numbers, but not on structures. Operators are | |
5d161b24 | 8548 | often defined on groups of types. |
c906108c | 8549 | |
b37052ae | 8550 | For the purposes of C and C@t{++}, the following definitions hold: |
c906108c SS |
8551 | |
8552 | @itemize @bullet | |
53a5351d | 8553 | |
c906108c | 8554 | @item |
c906108c | 8555 | @emph{Integral types} include @code{int} with any of its storage-class |
b37052ae | 8556 | specifiers; @code{char}; @code{enum}; and, for C@t{++}, @code{bool}. |
c906108c SS |
8557 | |
8558 | @item | |
d4f3574e SS |
8559 | @emph{Floating-point types} include @code{float}, @code{double}, and |
8560 | @code{long double} (if supported by the target platform). | |
c906108c SS |
8561 | |
8562 | @item | |
53a5351d | 8563 | @emph{Pointer types} include all types defined as @code{(@var{type} *)}. |
c906108c SS |
8564 | |
8565 | @item | |
8566 | @emph{Scalar types} include all of the above. | |
53a5351d | 8567 | |
c906108c SS |
8568 | @end itemize |
8569 | ||
8570 | @noindent | |
8571 | The following operators are supported. They are listed here | |
8572 | in order of increasing precedence: | |
8573 | ||
8574 | @table @code | |
8575 | @item , | |
8576 | The comma or sequencing operator. Expressions in a comma-separated list | |
8577 | are evaluated from left to right, with the result of the entire | |
8578 | expression being the last expression evaluated. | |
8579 | ||
8580 | @item = | |
8581 | Assignment. The value of an assignment expression is the value | |
8582 | assigned. Defined on scalar types. | |
8583 | ||
8584 | @item @var{op}= | |
8585 | Used in an expression of the form @w{@code{@var{a} @var{op}= @var{b}}}, | |
8586 | and translated to @w{@code{@var{a} = @var{a op b}}}. | |
d4f3574e | 8587 | @w{@code{@var{op}=}} and @code{=} have the same precedence. |
c906108c SS |
8588 | @var{op} is any one of the operators @code{|}, @code{^}, @code{&}, |
8589 | @code{<<}, @code{>>}, @code{+}, @code{-}, @code{*}, @code{/}, @code{%}. | |
8590 | ||
8591 | @item ?: | |
8592 | The ternary operator. @code{@var{a} ? @var{b} : @var{c}} can be thought | |
8593 | of as: if @var{a} then @var{b} else @var{c}. @var{a} should be of an | |
8594 | integral type. | |
8595 | ||
8596 | @item || | |
8597 | Logical @sc{or}. Defined on integral types. | |
8598 | ||
8599 | @item && | |
8600 | Logical @sc{and}. Defined on integral types. | |
8601 | ||
8602 | @item | | |
8603 | Bitwise @sc{or}. Defined on integral types. | |
8604 | ||
8605 | @item ^ | |
8606 | Bitwise exclusive-@sc{or}. Defined on integral types. | |
8607 | ||
8608 | @item & | |
8609 | Bitwise @sc{and}. Defined on integral types. | |
8610 | ||
8611 | @item ==@r{, }!= | |
8612 | Equality and inequality. Defined on scalar types. The value of these | |
8613 | expressions is 0 for false and non-zero for true. | |
8614 | ||
8615 | @item <@r{, }>@r{, }<=@r{, }>= | |
8616 | Less than, greater than, less than or equal, greater than or equal. | |
8617 | Defined on scalar types. The value of these expressions is 0 for false | |
8618 | and non-zero for true. | |
8619 | ||
8620 | @item <<@r{, }>> | |
8621 | left shift, and right shift. Defined on integral types. | |
8622 | ||
8623 | @item @@ | |
8624 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
8625 | ||
8626 | @item +@r{, }- | |
8627 | Addition and subtraction. Defined on integral types, floating-point types and | |
8628 | pointer types. | |
8629 | ||
8630 | @item *@r{, }/@r{, }% | |
8631 | Multiplication, division, and modulus. Multiplication and division are | |
8632 | defined on integral and floating-point types. Modulus is defined on | |
8633 | integral types. | |
8634 | ||
8635 | @item ++@r{, }-- | |
8636 | Increment and decrement. When appearing before a variable, the | |
8637 | operation is performed before the variable is used in an expression; | |
8638 | when appearing after it, the variable's value is used before the | |
8639 | operation takes place. | |
8640 | ||
8641 | @item * | |
8642 | Pointer dereferencing. Defined on pointer types. Same precedence as | |
8643 | @code{++}. | |
8644 | ||
8645 | @item & | |
8646 | Address operator. Defined on variables. Same precedence as @code{++}. | |
8647 | ||
b37052ae EZ |
8648 | For debugging C@t{++}, @value{GDBN} implements a use of @samp{&} beyond what is |
8649 | allowed in the C@t{++} language itself: you can use @samp{&(&@var{ref})} | |
c906108c | 8650 | (or, if you prefer, simply @samp{&&@var{ref}}) to examine the address |
b37052ae | 8651 | where a C@t{++} reference variable (declared with @samp{&@var{ref}}) is |
c906108c | 8652 | stored. |
c906108c SS |
8653 | |
8654 | @item - | |
8655 | Negative. Defined on integral and floating-point types. Same | |
8656 | precedence as @code{++}. | |
8657 | ||
8658 | @item ! | |
8659 | Logical negation. Defined on integral types. Same precedence as | |
8660 | @code{++}. | |
8661 | ||
8662 | @item ~ | |
8663 | Bitwise complement operator. Defined on integral types. Same precedence as | |
8664 | @code{++}. | |
8665 | ||
8666 | ||
8667 | @item .@r{, }-> | |
8668 | Structure member, and pointer-to-structure member. For convenience, | |
8669 | @value{GDBN} regards the two as equivalent, choosing whether to dereference a | |
8670 | pointer based on the stored type information. | |
8671 | Defined on @code{struct} and @code{union} data. | |
8672 | ||
c906108c SS |
8673 | @item .*@r{, }->* |
8674 | Dereferences of pointers to members. | |
c906108c SS |
8675 | |
8676 | @item [] | |
8677 | Array indexing. @code{@var{a}[@var{i}]} is defined as | |
8678 | @code{*(@var{a}+@var{i})}. Same precedence as @code{->}. | |
8679 | ||
8680 | @item () | |
8681 | Function parameter list. Same precedence as @code{->}. | |
8682 | ||
c906108c | 8683 | @item :: |
b37052ae | 8684 | C@t{++} scope resolution operator. Defined on @code{struct}, @code{union}, |
7a292a7a | 8685 | and @code{class} types. |
c906108c SS |
8686 | |
8687 | @item :: | |
7a292a7a SS |
8688 | Doubled colons also represent the @value{GDBN} scope operator |
8689 | (@pxref{Expressions, ,Expressions}). Same precedence as @code{::}, | |
8690 | above. | |
c906108c SS |
8691 | @end table |
8692 | ||
c906108c SS |
8693 | If an operator is redefined in the user code, @value{GDBN} usually |
8694 | attempts to invoke the redefined version instead of using the operator's | |
8695 | predefined meaning. | |
c906108c | 8696 | |
c906108c | 8697 | @menu |
5d161b24 | 8698 | * C Constants:: |
c906108c SS |
8699 | @end menu |
8700 | ||
6d2ebf8b | 8701 | @node C Constants |
b37052ae | 8702 | @subsubsection C and C@t{++} constants |
c906108c | 8703 | |
b37052ae | 8704 | @cindex C and C@t{++} constants |
c906108c | 8705 | |
b37052ae | 8706 | @value{GDBN} allows you to express the constants of C and C@t{++} in the |
c906108c | 8707 | following ways: |
c906108c SS |
8708 | |
8709 | @itemize @bullet | |
8710 | @item | |
8711 | Integer constants are a sequence of digits. Octal constants are | |
6ca652b0 EZ |
8712 | specified by a leading @samp{0} (i.e.@: zero), and hexadecimal constants |
8713 | by a leading @samp{0x} or @samp{0X}. Constants may also end with a letter | |
c906108c SS |
8714 | @samp{l}, specifying that the constant should be treated as a |
8715 | @code{long} value. | |
8716 | ||
8717 | @item | |
8718 | Floating point constants are a sequence of digits, followed by a decimal | |
8719 | point, followed by a sequence of digits, and optionally followed by an | |
8720 | exponent. An exponent is of the form: | |
8721 | @samp{@w{e@r{[[}+@r{]|}-@r{]}@var{nnn}}}, where @var{nnn} is another | |
8722 | sequence of digits. The @samp{+} is optional for positive exponents. | |
d4f3574e SS |
8723 | A floating-point constant may also end with a letter @samp{f} or |
8724 | @samp{F}, specifying that the constant should be treated as being of | |
8725 | the @code{float} (as opposed to the default @code{double}) type; or with | |
8726 | a letter @samp{l} or @samp{L}, which specifies a @code{long double} | |
8727 | constant. | |
c906108c SS |
8728 | |
8729 | @item | |
8730 | Enumerated constants consist of enumerated identifiers, or their | |
8731 | integral equivalents. | |
8732 | ||
8733 | @item | |
8734 | Character constants are a single character surrounded by single quotes | |
8735 | (@code{'}), or a number---the ordinal value of the corresponding character | |
d4f3574e | 8736 | (usually its @sc{ascii} value). Within quotes, the single character may |
c906108c SS |
8737 | be represented by a letter or by @dfn{escape sequences}, which are of |
8738 | the form @samp{\@var{nnn}}, where @var{nnn} is the octal representation | |
8739 | of the character's ordinal value; or of the form @samp{\@var{x}}, where | |
8740 | @samp{@var{x}} is a predefined special character---for example, | |
8741 | @samp{\n} for newline. | |
8742 | ||
8743 | @item | |
96a2c332 SS |
8744 | String constants are a sequence of character constants surrounded by |
8745 | double quotes (@code{"}). Any valid character constant (as described | |
8746 | above) may appear. Double quotes within the string must be preceded by | |
8747 | a backslash, so for instance @samp{"a\"b'c"} is a string of five | |
8748 | characters. | |
c906108c SS |
8749 | |
8750 | @item | |
8751 | Pointer constants are an integral value. You can also write pointers | |
8752 | to constants using the C operator @samp{&}. | |
8753 | ||
8754 | @item | |
8755 | Array constants are comma-separated lists surrounded by braces @samp{@{} | |
8756 | and @samp{@}}; for example, @samp{@{1,2,3@}} is a three-element array of | |
8757 | integers, @samp{@{@{1,2@}, @{3,4@}, @{5,6@}@}} is a three-by-two array, | |
8758 | and @samp{@{&"hi", &"there", &"fred"@}} is a three-element array of pointers. | |
8759 | @end itemize | |
8760 | ||
c906108c | 8761 | @menu |
5d161b24 DB |
8762 | * C plus plus expressions:: |
8763 | * C Defaults:: | |
8764 | * C Checks:: | |
c906108c | 8765 | |
5d161b24 | 8766 | * Debugging C:: |
c906108c SS |
8767 | @end menu |
8768 | ||
6d2ebf8b | 8769 | @node C plus plus expressions |
b37052ae EZ |
8770 | @subsubsection C@t{++} expressions |
8771 | ||
8772 | @cindex expressions in C@t{++} | |
8773 | @value{GDBN} expression handling can interpret most C@t{++} expressions. | |
8774 | ||
0179ffac DC |
8775 | @cindex debugging C@t{++} programs |
8776 | @cindex C@t{++} compilers | |
8777 | @cindex debug formats and C@t{++} | |
8778 | @cindex @value{NGCC} and C@t{++} | |
c906108c | 8779 | @quotation |
b37052ae | 8780 | @emph{Warning:} @value{GDBN} can only debug C@t{++} code if you use the |
0179ffac DC |
8781 | proper compiler and the proper debug format. Currently, @value{GDBN} |
8782 | works best when debugging C@t{++} code that is compiled with | |
8783 | @value{NGCC} 2.95.3 or with @value{NGCC} 3.1 or newer, using the options | |
8784 | @option{-gdwarf-2} or @option{-gstabs+}. DWARF 2 is preferred over | |
8785 | stabs+. Most configurations of @value{NGCC} emit either DWARF 2 or | |
8786 | stabs+ as their default debug format, so you usually don't need to | |
8787 | specify a debug format explicitly. Other compilers and/or debug formats | |
8788 | are likely to work badly or not at all when using @value{GDBN} to debug | |
8789 | C@t{++} code. | |
c906108c | 8790 | @end quotation |
c906108c SS |
8791 | |
8792 | @enumerate | |
8793 | ||
8794 | @cindex member functions | |
8795 | @item | |
8796 | Member function calls are allowed; you can use expressions like | |
8797 | ||
474c8240 | 8798 | @smallexample |
c906108c | 8799 | count = aml->GetOriginal(x, y) |
474c8240 | 8800 | @end smallexample |
c906108c | 8801 | |
41afff9a | 8802 | @vindex this@r{, inside C@t{++} member functions} |
b37052ae | 8803 | @cindex namespace in C@t{++} |
c906108c SS |
8804 | @item |
8805 | While a member function is active (in the selected stack frame), your | |
8806 | expressions have the same namespace available as the member function; | |
8807 | that is, @value{GDBN} allows implicit references to the class instance | |
b37052ae | 8808 | pointer @code{this} following the same rules as C@t{++}. |
c906108c | 8809 | |
c906108c | 8810 | @cindex call overloaded functions |
d4f3574e | 8811 | @cindex overloaded functions, calling |
b37052ae | 8812 | @cindex type conversions in C@t{++} |
c906108c SS |
8813 | @item |
8814 | You can call overloaded functions; @value{GDBN} resolves the function | |
d4f3574e | 8815 | call to the right definition, with some restrictions. @value{GDBN} does not |
c906108c SS |
8816 | perform overload resolution involving user-defined type conversions, |
8817 | calls to constructors, or instantiations of templates that do not exist | |
8818 | in the program. It also cannot handle ellipsis argument lists or | |
8819 | default arguments. | |
8820 | ||
8821 | It does perform integral conversions and promotions, floating-point | |
8822 | promotions, arithmetic conversions, pointer conversions, conversions of | |
8823 | class objects to base classes, and standard conversions such as those of | |
8824 | functions or arrays to pointers; it requires an exact match on the | |
8825 | number of function arguments. | |
8826 | ||
8827 | Overload resolution is always performed, unless you have specified | |
8828 | @code{set overload-resolution off}. @xref{Debugging C plus plus, | |
b37052ae | 8829 | ,@value{GDBN} features for C@t{++}}. |
c906108c | 8830 | |
d4f3574e | 8831 | You must specify @code{set overload-resolution off} in order to use an |
c906108c SS |
8832 | explicit function signature to call an overloaded function, as in |
8833 | @smallexample | |
8834 | p 'foo(char,int)'('x', 13) | |
8835 | @end smallexample | |
d4f3574e | 8836 | |
c906108c | 8837 | The @value{GDBN} command-completion facility can simplify this; |
d4f3574e | 8838 | see @ref{Completion, ,Command completion}. |
c906108c | 8839 | |
c906108c SS |
8840 | @cindex reference declarations |
8841 | @item | |
b37052ae EZ |
8842 | @value{GDBN} understands variables declared as C@t{++} references; you can use |
8843 | them in expressions just as you do in C@t{++} source---they are automatically | |
c906108c SS |
8844 | dereferenced. |
8845 | ||
8846 | In the parameter list shown when @value{GDBN} displays a frame, the values of | |
8847 | reference variables are not displayed (unlike other variables); this | |
8848 | avoids clutter, since references are often used for large structures. | |
8849 | The @emph{address} of a reference variable is always shown, unless | |
8850 | you have specified @samp{set print address off}. | |
8851 | ||
8852 | @item | |
b37052ae | 8853 | @value{GDBN} supports the C@t{++} name resolution operator @code{::}---your |
c906108c SS |
8854 | expressions can use it just as expressions in your program do. Since |
8855 | one scope may be defined in another, you can use @code{::} repeatedly if | |
8856 | necessary, for example in an expression like | |
8857 | @samp{@var{scope1}::@var{scope2}::@var{name}}. @value{GDBN} also allows | |
b37052ae | 8858 | resolving name scope by reference to source files, in both C and C@t{++} |
c906108c SS |
8859 | debugging (@pxref{Variables, ,Program variables}). |
8860 | @end enumerate | |
8861 | ||
b37052ae | 8862 | In addition, when used with HP's C@t{++} compiler, @value{GDBN} supports |
53a5351d JM |
8863 | calling virtual functions correctly, printing out virtual bases of |
8864 | objects, calling functions in a base subobject, casting objects, and | |
8865 | invoking user-defined operators. | |
c906108c | 8866 | |
6d2ebf8b | 8867 | @node C Defaults |
b37052ae | 8868 | @subsubsection C and C@t{++} defaults |
7a292a7a | 8869 | |
b37052ae | 8870 | @cindex C and C@t{++} defaults |
c906108c | 8871 | |
c906108c SS |
8872 | If you allow @value{GDBN} to set type and range checking automatically, they |
8873 | both default to @code{off} whenever the working language changes to | |
b37052ae | 8874 | C or C@t{++}. This happens regardless of whether you or @value{GDBN} |
c906108c | 8875 | selects the working language. |
c906108c SS |
8876 | |
8877 | If you allow @value{GDBN} to set the language automatically, it | |
8878 | recognizes source files whose names end with @file{.c}, @file{.C}, or | |
8879 | @file{.cc}, etc, and when @value{GDBN} enters code compiled from one of | |
b37052ae | 8880 | these files, it sets the working language to C or C@t{++}. |
c906108c SS |
8881 | @xref{Automatically, ,Having @value{GDBN} infer the source language}, |
8882 | for further details. | |
8883 | ||
c906108c SS |
8884 | @c Type checking is (a) primarily motivated by Modula-2, and (b) |
8885 | @c unimplemented. If (b) changes, it might make sense to let this node | |
8886 | @c appear even if Mod-2 does not, but meanwhile ignore it. roland 16jul93. | |
7a292a7a | 8887 | |
6d2ebf8b | 8888 | @node C Checks |
b37052ae | 8889 | @subsubsection C and C@t{++} type and range checks |
7a292a7a | 8890 | |
b37052ae | 8891 | @cindex C and C@t{++} checks |
c906108c | 8892 | |
b37052ae | 8893 | By default, when @value{GDBN} parses C or C@t{++} expressions, type checking |
c906108c SS |
8894 | is not used. However, if you turn type checking on, @value{GDBN} |
8895 | considers two variables type equivalent if: | |
8896 | ||
8897 | @itemize @bullet | |
8898 | @item | |
8899 | The two variables are structured and have the same structure, union, or | |
8900 | enumerated tag. | |
8901 | ||
8902 | @item | |
8903 | The two variables have the same type name, or types that have been | |
8904 | declared equivalent through @code{typedef}. | |
8905 | ||
8906 | @ignore | |
8907 | @c leaving this out because neither J Gilmore nor R Pesch understand it. | |
8908 | @c FIXME--beers? | |
8909 | @item | |
8910 | The two @code{struct}, @code{union}, or @code{enum} variables are | |
8911 | declared in the same declaration. (Note: this may not be true for all C | |
8912 | compilers.) | |
8913 | @end ignore | |
8914 | @end itemize | |
8915 | ||
8916 | Range checking, if turned on, is done on mathematical operations. Array | |
8917 | indices are not checked, since they are often used to index a pointer | |
8918 | that is not itself an array. | |
c906108c | 8919 | |
6d2ebf8b | 8920 | @node Debugging C |
c906108c | 8921 | @subsubsection @value{GDBN} and C |
c906108c SS |
8922 | |
8923 | The @code{set print union} and @code{show print union} commands apply to | |
8924 | the @code{union} type. When set to @samp{on}, any @code{union} that is | |
7a292a7a SS |
8925 | inside a @code{struct} or @code{class} is also printed. Otherwise, it |
8926 | appears as @samp{@{...@}}. | |
c906108c SS |
8927 | |
8928 | The @code{@@} operator aids in the debugging of dynamic arrays, formed | |
8929 | with pointers and a memory allocation function. @xref{Expressions, | |
8930 | ,Expressions}. | |
8931 | ||
c906108c | 8932 | @menu |
5d161b24 | 8933 | * Debugging C plus plus:: |
c906108c SS |
8934 | @end menu |
8935 | ||
6d2ebf8b | 8936 | @node Debugging C plus plus |
b37052ae | 8937 | @subsubsection @value{GDBN} features for C@t{++} |
c906108c | 8938 | |
b37052ae | 8939 | @cindex commands for C@t{++} |
7a292a7a | 8940 | |
b37052ae EZ |
8941 | Some @value{GDBN} commands are particularly useful with C@t{++}, and some are |
8942 | designed specifically for use with C@t{++}. Here is a summary: | |
c906108c SS |
8943 | |
8944 | @table @code | |
8945 | @cindex break in overloaded functions | |
8946 | @item @r{breakpoint menus} | |
8947 | When you want a breakpoint in a function whose name is overloaded, | |
8948 | @value{GDBN} breakpoint menus help you specify which function definition | |
8949 | you want. @xref{Breakpoint Menus,,Breakpoint menus}. | |
8950 | ||
b37052ae | 8951 | @cindex overloading in C@t{++} |
c906108c SS |
8952 | @item rbreak @var{regex} |
8953 | Setting breakpoints using regular expressions is helpful for setting | |
8954 | breakpoints on overloaded functions that are not members of any special | |
8955 | classes. | |
8956 | @xref{Set Breaks, ,Setting breakpoints}. | |
8957 | ||
b37052ae | 8958 | @cindex C@t{++} exception handling |
c906108c SS |
8959 | @item catch throw |
8960 | @itemx catch catch | |
b37052ae | 8961 | Debug C@t{++} exception handling using these commands. @xref{Set |
c906108c SS |
8962 | Catchpoints, , Setting catchpoints}. |
8963 | ||
8964 | @cindex inheritance | |
8965 | @item ptype @var{typename} | |
8966 | Print inheritance relationships as well as other information for type | |
8967 | @var{typename}. | |
8968 | @xref{Symbols, ,Examining the Symbol Table}. | |
8969 | ||
b37052ae | 8970 | @cindex C@t{++} symbol display |
c906108c SS |
8971 | @item set print demangle |
8972 | @itemx show print demangle | |
8973 | @itemx set print asm-demangle | |
8974 | @itemx show print asm-demangle | |
b37052ae EZ |
8975 | Control whether C@t{++} symbols display in their source form, both when |
8976 | displaying code as C@t{++} source and when displaying disassemblies. | |
c906108c SS |
8977 | @xref{Print Settings, ,Print settings}. |
8978 | ||
8979 | @item set print object | |
8980 | @itemx show print object | |
8981 | Choose whether to print derived (actual) or declared types of objects. | |
8982 | @xref{Print Settings, ,Print settings}. | |
8983 | ||
8984 | @item set print vtbl | |
8985 | @itemx show print vtbl | |
8986 | Control the format for printing virtual function tables. | |
8987 | @xref{Print Settings, ,Print settings}. | |
c906108c | 8988 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 8989 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
8990 | |
8991 | @kindex set overload-resolution | |
d4f3574e | 8992 | @cindex overloaded functions, overload resolution |
c906108c | 8993 | @item set overload-resolution on |
b37052ae | 8994 | Enable overload resolution for C@t{++} expression evaluation. The default |
c906108c SS |
8995 | is on. For overloaded functions, @value{GDBN} evaluates the arguments |
8996 | and searches for a function whose signature matches the argument types, | |
b37052ae | 8997 | using the standard C@t{++} conversion rules (see @ref{C plus plus expressions, ,C@t{++} |
d4f3574e | 8998 | expressions}, for details). If it cannot find a match, it emits a |
c906108c SS |
8999 | message. |
9000 | ||
9001 | @item set overload-resolution off | |
b37052ae | 9002 | Disable overload resolution for C@t{++} expression evaluation. For |
c906108c SS |
9003 | overloaded functions that are not class member functions, @value{GDBN} |
9004 | chooses the first function of the specified name that it finds in the | |
9005 | symbol table, whether or not its arguments are of the correct type. For | |
9006 | overloaded functions that are class member functions, @value{GDBN} | |
9007 | searches for a function whose signature @emph{exactly} matches the | |
9008 | argument types. | |
c906108c | 9009 | |
9c16f35a EZ |
9010 | @kindex show overload-resolution |
9011 | @item show overload-resolution | |
9012 | Show the current setting of overload resolution. | |
9013 | ||
c906108c SS |
9014 | @item @r{Overloaded symbol names} |
9015 | You can specify a particular definition of an overloaded symbol, using | |
b37052ae | 9016 | the same notation that is used to declare such symbols in C@t{++}: type |
c906108c SS |
9017 | @code{@var{symbol}(@var{types})} rather than just @var{symbol}. You can |
9018 | also use the @value{GDBN} command-line word completion facilities to list the | |
9019 | available choices, or to finish the type list for you. | |
9020 | @xref{Completion,, Command completion}, for details on how to do this. | |
9021 | @end table | |
c906108c | 9022 | |
b37303ee AF |
9023 | @node Objective-C |
9024 | @subsection Objective-C | |
9025 | ||
9026 | @cindex Objective-C | |
9027 | This section provides information about some commands and command | |
721c2651 EZ |
9028 | options that are useful for debugging Objective-C code. See also |
9029 | @ref{Symbols, info classes}, and @ref{Symbols, info selectors}, for a | |
9030 | few more commands specific to Objective-C support. | |
b37303ee AF |
9031 | |
9032 | @menu | |
b383017d RM |
9033 | * Method Names in Commands:: |
9034 | * The Print Command with Objective-C:: | |
b37303ee AF |
9035 | @end menu |
9036 | ||
9037 | @node Method Names in Commands, The Print Command with Objective-C, Objective-C, Objective-C | |
9038 | @subsubsection Method Names in Commands | |
9039 | ||
9040 | The following commands have been extended to accept Objective-C method | |
9041 | names as line specifications: | |
9042 | ||
9043 | @kindex clear@r{, and Objective-C} | |
9044 | @kindex break@r{, and Objective-C} | |
9045 | @kindex info line@r{, and Objective-C} | |
9046 | @kindex jump@r{, and Objective-C} | |
9047 | @kindex list@r{, and Objective-C} | |
9048 | @itemize | |
9049 | @item @code{clear} | |
9050 | @item @code{break} | |
9051 | @item @code{info line} | |
9052 | @item @code{jump} | |
9053 | @item @code{list} | |
9054 | @end itemize | |
9055 | ||
9056 | A fully qualified Objective-C method name is specified as | |
9057 | ||
9058 | @smallexample | |
9059 | -[@var{Class} @var{methodName}] | |
9060 | @end smallexample | |
9061 | ||
c552b3bb JM |
9062 | where the minus sign is used to indicate an instance method and a |
9063 | plus sign (not shown) is used to indicate a class method. The class | |
9064 | name @var{Class} and method name @var{methodName} are enclosed in | |
9065 | brackets, similar to the way messages are specified in Objective-C | |
9066 | source code. For example, to set a breakpoint at the @code{create} | |
9067 | instance method of class @code{Fruit} in the program currently being | |
9068 | debugged, enter: | |
b37303ee AF |
9069 | |
9070 | @smallexample | |
9071 | break -[Fruit create] | |
9072 | @end smallexample | |
9073 | ||
9074 | To list ten program lines around the @code{initialize} class method, | |
9075 | enter: | |
9076 | ||
9077 | @smallexample | |
9078 | list +[NSText initialize] | |
9079 | @end smallexample | |
9080 | ||
c552b3bb JM |
9081 | In the current version of @value{GDBN}, the plus or minus sign is |
9082 | required. In future versions of @value{GDBN}, the plus or minus | |
9083 | sign will be optional, but you can use it to narrow the search. It | |
9084 | is also possible to specify just a method name: | |
b37303ee AF |
9085 | |
9086 | @smallexample | |
9087 | break create | |
9088 | @end smallexample | |
9089 | ||
9090 | You must specify the complete method name, including any colons. If | |
9091 | your program's source files contain more than one @code{create} method, | |
9092 | you'll be presented with a numbered list of classes that implement that | |
9093 | method. Indicate your choice by number, or type @samp{0} to exit if | |
9094 | none apply. | |
9095 | ||
9096 | As another example, to clear a breakpoint established at the | |
9097 | @code{makeKeyAndOrderFront:} method of the @code{NSWindow} class, enter: | |
9098 | ||
9099 | @smallexample | |
9100 | clear -[NSWindow makeKeyAndOrderFront:] | |
9101 | @end smallexample | |
9102 | ||
9103 | @node The Print Command with Objective-C | |
9104 | @subsubsection The Print Command With Objective-C | |
721c2651 | 9105 | @cindex Objective-C, print objects |
c552b3bb JM |
9106 | @kindex print-object |
9107 | @kindex po @r{(@code{print-object})} | |
b37303ee | 9108 | |
c552b3bb | 9109 | The print command has also been extended to accept methods. For example: |
b37303ee AF |
9110 | |
9111 | @smallexample | |
c552b3bb | 9112 | print -[@var{object} hash] |
b37303ee AF |
9113 | @end smallexample |
9114 | ||
9115 | @cindex print an Objective-C object description | |
c552b3bb JM |
9116 | @cindex @code{_NSPrintForDebugger}, and printing Objective-C objects |
9117 | @noindent | |
9118 | will tell @value{GDBN} to send the @code{hash} message to @var{object} | |
9119 | and print the result. Also, an additional command has been added, | |
9120 | @code{print-object} or @code{po} for short, which is meant to print | |
9121 | the description of an object. However, this command may only work | |
9122 | with certain Objective-C libraries that have a particular hook | |
9123 | function, @code{_NSPrintForDebugger}, defined. | |
b37303ee | 9124 | |
09d4efe1 EZ |
9125 | @node Fortran |
9126 | @subsection Fortran | |
9127 | @cindex Fortran-specific support in @value{GDBN} | |
9128 | ||
814e32d7 WZ |
9129 | @value{GDBN} can be used to debug programs written in Fortran, but it |
9130 | currently supports only the features of Fortran 77 language. | |
9131 | ||
9132 | @cindex trailing underscore, in Fortran symbols | |
9133 | Some Fortran compilers (@sc{gnu} Fortran 77 and Fortran 95 compilers | |
9134 | among them) append an underscore to the names of variables and | |
9135 | functions. When you debug programs compiled by those compilers, you | |
9136 | will need to refer to variables and functions with a trailing | |
9137 | underscore. | |
9138 | ||
9139 | @menu | |
9140 | * Fortran Operators:: Fortran operators and expressions | |
9141 | * Fortran Defaults:: Default settings for Fortran | |
9142 | * Special Fortran commands:: Special @value{GDBN} commands for Fortran | |
9143 | @end menu | |
9144 | ||
9145 | @node Fortran Operators | |
9146 | @subsubsection Fortran operators and expressions | |
9147 | ||
9148 | @cindex Fortran operators and expressions | |
9149 | ||
9150 | Operators must be defined on values of specific types. For instance, | |
9151 | @code{+} is defined on numbers, but not on characters or other non- | |
ff2587ec | 9152 | arithmetic types. Operators are often defined on groups of types. |
814e32d7 WZ |
9153 | |
9154 | @table @code | |
9155 | @item ** | |
9156 | The exponentiation operator. It raises the first operand to the power | |
9157 | of the second one. | |
9158 | ||
9159 | @item : | |
9160 | The range operator. Normally used in the form of array(low:high) to | |
9161 | represent a section of array. | |
9162 | @end table | |
9163 | ||
9164 | @node Fortran Defaults | |
9165 | @subsubsection Fortran Defaults | |
9166 | ||
9167 | @cindex Fortran Defaults | |
9168 | ||
9169 | Fortran symbols are usually case-insensitive, so @value{GDBN} by | |
9170 | default uses case-insensitive matches for Fortran symbols. You can | |
9171 | change that with the @samp{set case-insensitive} command, see | |
9172 | @ref{Symbols}, for the details. | |
9173 | ||
9174 | @node Special Fortran commands | |
9175 | @subsubsection Special Fortran commands | |
9176 | ||
9177 | @cindex Special Fortran commands | |
9178 | ||
9179 | @value{GDBN} had some commands to support Fortran specific feature, | |
9180 | such as common block displaying. | |
9181 | ||
09d4efe1 EZ |
9182 | @table @code |
9183 | @cindex @code{COMMON} blocks, Fortran | |
9184 | @kindex info common | |
9185 | @item info common @r{[}@var{common-name}@r{]} | |
9186 | This command prints the values contained in the Fortran @code{COMMON} | |
9187 | block whose name is @var{common-name}. With no argument, the names of | |
9188 | all @code{COMMON} blocks visible at current program location are | |
9189 | printed. | |
9190 | @end table | |
9191 | ||
9c16f35a EZ |
9192 | @node Pascal |
9193 | @subsection Pascal | |
9194 | ||
9195 | @cindex Pascal support in @value{GDBN}, limitations | |
9196 | Debugging Pascal programs which use sets, subranges, file variables, or | |
9197 | nested functions does not currently work. @value{GDBN} does not support | |
9198 | entering expressions, printing values, or similar features using Pascal | |
9199 | syntax. | |
9200 | ||
9201 | The Pascal-specific command @code{set print pascal_static-members} | |
9202 | controls whether static members of Pascal objects are displayed. | |
9203 | @xref{Print Settings, pascal_static-members}. | |
9204 | ||
09d4efe1 | 9205 | @node Modula-2 |
c906108c | 9206 | @subsection Modula-2 |
7a292a7a | 9207 | |
d4f3574e | 9208 | @cindex Modula-2, @value{GDBN} support |
c906108c SS |
9209 | |
9210 | The extensions made to @value{GDBN} to support Modula-2 only support | |
9211 | output from the @sc{gnu} Modula-2 compiler (which is currently being | |
9212 | developed). Other Modula-2 compilers are not currently supported, and | |
9213 | attempting to debug executables produced by them is most likely | |
9214 | to give an error as @value{GDBN} reads in the executable's symbol | |
9215 | table. | |
9216 | ||
9217 | @cindex expressions in Modula-2 | |
9218 | @menu | |
9219 | * M2 Operators:: Built-in operators | |
9220 | * Built-In Func/Proc:: Built-in functions and procedures | |
9221 | * M2 Constants:: Modula-2 constants | |
9222 | * M2 Defaults:: Default settings for Modula-2 | |
9223 | * Deviations:: Deviations from standard Modula-2 | |
9224 | * M2 Checks:: Modula-2 type and range checks | |
9225 | * M2 Scope:: The scope operators @code{::} and @code{.} | |
9226 | * GDB/M2:: @value{GDBN} and Modula-2 | |
9227 | @end menu | |
9228 | ||
6d2ebf8b | 9229 | @node M2 Operators |
c906108c SS |
9230 | @subsubsection Operators |
9231 | @cindex Modula-2 operators | |
9232 | ||
9233 | Operators must be defined on values of specific types. For instance, | |
9234 | @code{+} is defined on numbers, but not on structures. Operators are | |
9235 | often defined on groups of types. For the purposes of Modula-2, the | |
9236 | following definitions hold: | |
9237 | ||
9238 | @itemize @bullet | |
9239 | ||
9240 | @item | |
9241 | @emph{Integral types} consist of @code{INTEGER}, @code{CARDINAL}, and | |
9242 | their subranges. | |
9243 | ||
9244 | @item | |
9245 | @emph{Character types} consist of @code{CHAR} and its subranges. | |
9246 | ||
9247 | @item | |
9248 | @emph{Floating-point types} consist of @code{REAL}. | |
9249 | ||
9250 | @item | |
9251 | @emph{Pointer types} consist of anything declared as @code{POINTER TO | |
9252 | @var{type}}. | |
9253 | ||
9254 | @item | |
9255 | @emph{Scalar types} consist of all of the above. | |
9256 | ||
9257 | @item | |
9258 | @emph{Set types} consist of @code{SET} and @code{BITSET} types. | |
9259 | ||
9260 | @item | |
9261 | @emph{Boolean types} consist of @code{BOOLEAN}. | |
9262 | @end itemize | |
9263 | ||
9264 | @noindent | |
9265 | The following operators are supported, and appear in order of | |
9266 | increasing precedence: | |
9267 | ||
9268 | @table @code | |
9269 | @item , | |
9270 | Function argument or array index separator. | |
9271 | ||
9272 | @item := | |
9273 | Assignment. The value of @var{var} @code{:=} @var{value} is | |
9274 | @var{value}. | |
9275 | ||
9276 | @item <@r{, }> | |
9277 | Less than, greater than on integral, floating-point, or enumerated | |
9278 | types. | |
9279 | ||
9280 | @item <=@r{, }>= | |
96a2c332 | 9281 | Less than or equal to, greater than or equal to |
c906108c SS |
9282 | on integral, floating-point and enumerated types, or set inclusion on |
9283 | set types. Same precedence as @code{<}. | |
9284 | ||
9285 | @item =@r{, }<>@r{, }# | |
9286 | Equality and two ways of expressing inequality, valid on scalar types. | |
9287 | Same precedence as @code{<}. In @value{GDBN} scripts, only @code{<>} is | |
9288 | available for inequality, since @code{#} conflicts with the script | |
9289 | comment character. | |
9290 | ||
9291 | @item IN | |
9292 | Set membership. Defined on set types and the types of their members. | |
9293 | Same precedence as @code{<}. | |
9294 | ||
9295 | @item OR | |
9296 | Boolean disjunction. Defined on boolean types. | |
9297 | ||
9298 | @item AND@r{, }& | |
d4f3574e | 9299 | Boolean conjunction. Defined on boolean types. |
c906108c SS |
9300 | |
9301 | @item @@ | |
9302 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
9303 | ||
9304 | @item +@r{, }- | |
9305 | Addition and subtraction on integral and floating-point types, or union | |
9306 | and difference on set types. | |
9307 | ||
9308 | @item * | |
9309 | Multiplication on integral and floating-point types, or set intersection | |
9310 | on set types. | |
9311 | ||
9312 | @item / | |
9313 | Division on floating-point types, or symmetric set difference on set | |
9314 | types. Same precedence as @code{*}. | |
9315 | ||
9316 | @item DIV@r{, }MOD | |
9317 | Integer division and remainder. Defined on integral types. Same | |
9318 | precedence as @code{*}. | |
9319 | ||
9320 | @item - | |
9321 | Negative. Defined on @code{INTEGER} and @code{REAL} data. | |
9322 | ||
9323 | @item ^ | |
9324 | Pointer dereferencing. Defined on pointer types. | |
9325 | ||
9326 | @item NOT | |
9327 | Boolean negation. Defined on boolean types. Same precedence as | |
9328 | @code{^}. | |
9329 | ||
9330 | @item . | |
9331 | @code{RECORD} field selector. Defined on @code{RECORD} data. Same | |
9332 | precedence as @code{^}. | |
9333 | ||
9334 | @item [] | |
9335 | Array indexing. Defined on @code{ARRAY} data. Same precedence as @code{^}. | |
9336 | ||
9337 | @item () | |
9338 | Procedure argument list. Defined on @code{PROCEDURE} objects. Same precedence | |
9339 | as @code{^}. | |
9340 | ||
9341 | @item ::@r{, }. | |
9342 | @value{GDBN} and Modula-2 scope operators. | |
9343 | @end table | |
9344 | ||
9345 | @quotation | |
9346 | @emph{Warning:} Sets and their operations are not yet supported, so @value{GDBN} | |
9347 | treats the use of the operator @code{IN}, or the use of operators | |
9348 | @code{+}, @code{-}, @code{*}, @code{/}, @code{=}, , @code{<>}, @code{#}, | |
9349 | @code{<=}, and @code{>=} on sets as an error. | |
9350 | @end quotation | |
9351 | ||
cb51c4e0 | 9352 | |
6d2ebf8b | 9353 | @node Built-In Func/Proc |
c906108c | 9354 | @subsubsection Built-in functions and procedures |
cb51c4e0 | 9355 | @cindex Modula-2 built-ins |
c906108c SS |
9356 | |
9357 | Modula-2 also makes available several built-in procedures and functions. | |
9358 | In describing these, the following metavariables are used: | |
9359 | ||
9360 | @table @var | |
9361 | ||
9362 | @item a | |
9363 | represents an @code{ARRAY} variable. | |
9364 | ||
9365 | @item c | |
9366 | represents a @code{CHAR} constant or variable. | |
9367 | ||
9368 | @item i | |
9369 | represents a variable or constant of integral type. | |
9370 | ||
9371 | @item m | |
9372 | represents an identifier that belongs to a set. Generally used in the | |
9373 | same function with the metavariable @var{s}. The type of @var{s} should | |
9374 | be @code{SET OF @var{mtype}} (where @var{mtype} is the type of @var{m}). | |
9375 | ||
9376 | @item n | |
9377 | represents a variable or constant of integral or floating-point type. | |
9378 | ||
9379 | @item r | |
9380 | represents a variable or constant of floating-point type. | |
9381 | ||
9382 | @item t | |
9383 | represents a type. | |
9384 | ||
9385 | @item v | |
9386 | represents a variable. | |
9387 | ||
9388 | @item x | |
9389 | represents a variable or constant of one of many types. See the | |
9390 | explanation of the function for details. | |
9391 | @end table | |
9392 | ||
9393 | All Modula-2 built-in procedures also return a result, described below. | |
9394 | ||
9395 | @table @code | |
9396 | @item ABS(@var{n}) | |
9397 | Returns the absolute value of @var{n}. | |
9398 | ||
9399 | @item CAP(@var{c}) | |
9400 | If @var{c} is a lower case letter, it returns its upper case | |
c3f6f71d | 9401 | equivalent, otherwise it returns its argument. |
c906108c SS |
9402 | |
9403 | @item CHR(@var{i}) | |
9404 | Returns the character whose ordinal value is @var{i}. | |
9405 | ||
9406 | @item DEC(@var{v}) | |
c3f6f71d | 9407 | Decrements the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
9408 | |
9409 | @item DEC(@var{v},@var{i}) | |
9410 | Decrements the value in the variable @var{v} by @var{i}. Returns the | |
9411 | new value. | |
9412 | ||
9413 | @item EXCL(@var{m},@var{s}) | |
9414 | Removes the element @var{m} from the set @var{s}. Returns the new | |
9415 | set. | |
9416 | ||
9417 | @item FLOAT(@var{i}) | |
9418 | Returns the floating point equivalent of the integer @var{i}. | |
9419 | ||
9420 | @item HIGH(@var{a}) | |
9421 | Returns the index of the last member of @var{a}. | |
9422 | ||
9423 | @item INC(@var{v}) | |
c3f6f71d | 9424 | Increments the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
9425 | |
9426 | @item INC(@var{v},@var{i}) | |
9427 | Increments the value in the variable @var{v} by @var{i}. Returns the | |
9428 | new value. | |
9429 | ||
9430 | @item INCL(@var{m},@var{s}) | |
9431 | Adds the element @var{m} to the set @var{s} if it is not already | |
9432 | there. Returns the new set. | |
9433 | ||
9434 | @item MAX(@var{t}) | |
9435 | Returns the maximum value of the type @var{t}. | |
9436 | ||
9437 | @item MIN(@var{t}) | |
9438 | Returns the minimum value of the type @var{t}. | |
9439 | ||
9440 | @item ODD(@var{i}) | |
9441 | Returns boolean TRUE if @var{i} is an odd number. | |
9442 | ||
9443 | @item ORD(@var{x}) | |
9444 | Returns the ordinal value of its argument. For example, the ordinal | |
c3f6f71d JM |
9445 | value of a character is its @sc{ascii} value (on machines supporting the |
9446 | @sc{ascii} character set). @var{x} must be of an ordered type, which include | |
c906108c SS |
9447 | integral, character and enumerated types. |
9448 | ||
9449 | @item SIZE(@var{x}) | |
9450 | Returns the size of its argument. @var{x} can be a variable or a type. | |
9451 | ||
9452 | @item TRUNC(@var{r}) | |
9453 | Returns the integral part of @var{r}. | |
9454 | ||
9455 | @item VAL(@var{t},@var{i}) | |
9456 | Returns the member of the type @var{t} whose ordinal value is @var{i}. | |
9457 | @end table | |
9458 | ||
9459 | @quotation | |
9460 | @emph{Warning:} Sets and their operations are not yet supported, so | |
9461 | @value{GDBN} treats the use of procedures @code{INCL} and @code{EXCL} as | |
9462 | an error. | |
9463 | @end quotation | |
9464 | ||
9465 | @cindex Modula-2 constants | |
6d2ebf8b | 9466 | @node M2 Constants |
c906108c SS |
9467 | @subsubsection Constants |
9468 | ||
9469 | @value{GDBN} allows you to express the constants of Modula-2 in the following | |
9470 | ways: | |
9471 | ||
9472 | @itemize @bullet | |
9473 | ||
9474 | @item | |
9475 | Integer constants are simply a sequence of digits. When used in an | |
9476 | expression, a constant is interpreted to be type-compatible with the | |
9477 | rest of the expression. Hexadecimal integers are specified by a | |
9478 | trailing @samp{H}, and octal integers by a trailing @samp{B}. | |
9479 | ||
9480 | @item | |
9481 | Floating point constants appear as a sequence of digits, followed by a | |
9482 | decimal point and another sequence of digits. An optional exponent can | |
9483 | then be specified, in the form @samp{E@r{[}+@r{|}-@r{]}@var{nnn}}, where | |
9484 | @samp{@r{[}+@r{|}-@r{]}@var{nnn}} is the desired exponent. All of the | |
9485 | digits of the floating point constant must be valid decimal (base 10) | |
9486 | digits. | |
9487 | ||
9488 | @item | |
9489 | Character constants consist of a single character enclosed by a pair of | |
9490 | like quotes, either single (@code{'}) or double (@code{"}). They may | |
c3f6f71d | 9491 | also be expressed by their ordinal value (their @sc{ascii} value, usually) |
c906108c SS |
9492 | followed by a @samp{C}. |
9493 | ||
9494 | @item | |
9495 | String constants consist of a sequence of characters enclosed by a | |
9496 | pair of like quotes, either single (@code{'}) or double (@code{"}). | |
9497 | Escape sequences in the style of C are also allowed. @xref{C | |
b37052ae | 9498 | Constants, ,C and C@t{++} constants}, for a brief explanation of escape |
c906108c SS |
9499 | sequences. |
9500 | ||
9501 | @item | |
9502 | Enumerated constants consist of an enumerated identifier. | |
9503 | ||
9504 | @item | |
9505 | Boolean constants consist of the identifiers @code{TRUE} and | |
9506 | @code{FALSE}. | |
9507 | ||
9508 | @item | |
9509 | Pointer constants consist of integral values only. | |
9510 | ||
9511 | @item | |
9512 | Set constants are not yet supported. | |
9513 | @end itemize | |
9514 | ||
6d2ebf8b | 9515 | @node M2 Defaults |
c906108c SS |
9516 | @subsubsection Modula-2 defaults |
9517 | @cindex Modula-2 defaults | |
9518 | ||
9519 | If type and range checking are set automatically by @value{GDBN}, they | |
9520 | both default to @code{on} whenever the working language changes to | |
d4f3574e | 9521 | Modula-2. This happens regardless of whether you or @value{GDBN} |
c906108c SS |
9522 | selected the working language. |
9523 | ||
9524 | If you allow @value{GDBN} to set the language automatically, then entering | |
9525 | code compiled from a file whose name ends with @file{.mod} sets the | |
d4f3574e | 9526 | working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} set |
c906108c SS |
9527 | the language automatically}, for further details. |
9528 | ||
6d2ebf8b | 9529 | @node Deviations |
c906108c SS |
9530 | @subsubsection Deviations from standard Modula-2 |
9531 | @cindex Modula-2, deviations from | |
9532 | ||
9533 | A few changes have been made to make Modula-2 programs easier to debug. | |
9534 | This is done primarily via loosening its type strictness: | |
9535 | ||
9536 | @itemize @bullet | |
9537 | @item | |
9538 | Unlike in standard Modula-2, pointer constants can be formed by | |
9539 | integers. This allows you to modify pointer variables during | |
9540 | debugging. (In standard Modula-2, the actual address contained in a | |
9541 | pointer variable is hidden from you; it can only be modified | |
9542 | through direct assignment to another pointer variable or expression that | |
9543 | returned a pointer.) | |
9544 | ||
9545 | @item | |
9546 | C escape sequences can be used in strings and characters to represent | |
9547 | non-printable characters. @value{GDBN} prints out strings with these | |
9548 | escape sequences embedded. Single non-printable characters are | |
9549 | printed using the @samp{CHR(@var{nnn})} format. | |
9550 | ||
9551 | @item | |
9552 | The assignment operator (@code{:=}) returns the value of its right-hand | |
9553 | argument. | |
9554 | ||
9555 | @item | |
9556 | All built-in procedures both modify @emph{and} return their argument. | |
9557 | @end itemize | |
9558 | ||
6d2ebf8b | 9559 | @node M2 Checks |
c906108c SS |
9560 | @subsubsection Modula-2 type and range checks |
9561 | @cindex Modula-2 checks | |
9562 | ||
9563 | @quotation | |
9564 | @emph{Warning:} in this release, @value{GDBN} does not yet perform type or | |
9565 | range checking. | |
9566 | @end quotation | |
9567 | @c FIXME remove warning when type/range checks added | |
9568 | ||
9569 | @value{GDBN} considers two Modula-2 variables type equivalent if: | |
9570 | ||
9571 | @itemize @bullet | |
9572 | @item | |
9573 | They are of types that have been declared equivalent via a @code{TYPE | |
9574 | @var{t1} = @var{t2}} statement | |
9575 | ||
9576 | @item | |
9577 | They have been declared on the same line. (Note: This is true of the | |
9578 | @sc{gnu} Modula-2 compiler, but it may not be true of other compilers.) | |
9579 | @end itemize | |
9580 | ||
9581 | As long as type checking is enabled, any attempt to combine variables | |
9582 | whose types are not equivalent is an error. | |
9583 | ||
9584 | Range checking is done on all mathematical operations, assignment, array | |
9585 | index bounds, and all built-in functions and procedures. | |
9586 | ||
6d2ebf8b | 9587 | @node M2 Scope |
c906108c SS |
9588 | @subsubsection The scope operators @code{::} and @code{.} |
9589 | @cindex scope | |
41afff9a | 9590 | @cindex @code{.}, Modula-2 scope operator |
c906108c SS |
9591 | @cindex colon, doubled as scope operator |
9592 | @ifinfo | |
41afff9a | 9593 | @vindex colon-colon@r{, in Modula-2} |
c906108c SS |
9594 | @c Info cannot handle :: but TeX can. |
9595 | @end ifinfo | |
9596 | @iftex | |
41afff9a | 9597 | @vindex ::@r{, in Modula-2} |
c906108c SS |
9598 | @end iftex |
9599 | ||
9600 | There are a few subtle differences between the Modula-2 scope operator | |
9601 | (@code{.}) and the @value{GDBN} scope operator (@code{::}). The two have | |
9602 | similar syntax: | |
9603 | ||
474c8240 | 9604 | @smallexample |
c906108c SS |
9605 | |
9606 | @var{module} . @var{id} | |
9607 | @var{scope} :: @var{id} | |
474c8240 | 9608 | @end smallexample |
c906108c SS |
9609 | |
9610 | @noindent | |
9611 | where @var{scope} is the name of a module or a procedure, | |
9612 | @var{module} the name of a module, and @var{id} is any declared | |
9613 | identifier within your program, except another module. | |
9614 | ||
9615 | Using the @code{::} operator makes @value{GDBN} search the scope | |
9616 | specified by @var{scope} for the identifier @var{id}. If it is not | |
9617 | found in the specified scope, then @value{GDBN} searches all scopes | |
9618 | enclosing the one specified by @var{scope}. | |
9619 | ||
9620 | Using the @code{.} operator makes @value{GDBN} search the current scope for | |
9621 | the identifier specified by @var{id} that was imported from the | |
9622 | definition module specified by @var{module}. With this operator, it is | |
9623 | an error if the identifier @var{id} was not imported from definition | |
9624 | module @var{module}, or if @var{id} is not an identifier in | |
9625 | @var{module}. | |
9626 | ||
6d2ebf8b | 9627 | @node GDB/M2 |
c906108c SS |
9628 | @subsubsection @value{GDBN} and Modula-2 |
9629 | ||
9630 | Some @value{GDBN} commands have little use when debugging Modula-2 programs. | |
9631 | Five subcommands of @code{set print} and @code{show print} apply | |
b37052ae | 9632 | specifically to C and C@t{++}: @samp{vtbl}, @samp{demangle}, |
c906108c | 9633 | @samp{asm-demangle}, @samp{object}, and @samp{union}. The first four |
b37052ae | 9634 | apply to C@t{++}, and the last to the C @code{union} type, which has no direct |
c906108c SS |
9635 | analogue in Modula-2. |
9636 | ||
9637 | The @code{@@} operator (@pxref{Expressions, ,Expressions}), while available | |
d4f3574e | 9638 | with any language, is not useful with Modula-2. Its |
c906108c | 9639 | intent is to aid the debugging of @dfn{dynamic arrays}, which cannot be |
b37052ae | 9640 | created in Modula-2 as they can in C or C@t{++}. However, because an |
c906108c | 9641 | address can be specified by an integral constant, the construct |
d4f3574e | 9642 | @samp{@{@var{type}@}@var{adrexp}} is still useful. |
c906108c SS |
9643 | |
9644 | @cindex @code{#} in Modula-2 | |
9645 | In @value{GDBN} scripts, the Modula-2 inequality operator @code{#} is | |
9646 | interpreted as the beginning of a comment. Use @code{<>} instead. | |
c906108c | 9647 | |
e07c999f PH |
9648 | @node Ada |
9649 | @subsection Ada | |
9650 | @cindex Ada | |
9651 | ||
9652 | The extensions made to @value{GDBN} for Ada only support | |
9653 | output from the @sc{gnu} Ada (GNAT) compiler. | |
9654 | Other Ada compilers are not currently supported, and | |
9655 | attempting to debug executables produced by them is most likely | |
9656 | to be difficult. | |
9657 | ||
9658 | ||
9659 | @cindex expressions in Ada | |
9660 | @menu | |
9661 | * Ada Mode Intro:: General remarks on the Ada syntax | |
9662 | and semantics supported by Ada mode | |
9663 | in @value{GDBN}. | |
9664 | * Omissions from Ada:: Restrictions on the Ada expression syntax. | |
9665 | * Additions to Ada:: Extensions of the Ada expression syntax. | |
9666 | * Stopping Before Main Program:: Debugging the program during elaboration. | |
9667 | * Ada Glitches:: Known peculiarities of Ada mode. | |
9668 | @end menu | |
9669 | ||
9670 | @node Ada Mode Intro | |
9671 | @subsubsection Introduction | |
9672 | @cindex Ada mode, general | |
9673 | ||
9674 | The Ada mode of @value{GDBN} supports a fairly large subset of Ada expression | |
9675 | syntax, with some extensions. | |
9676 | The philosophy behind the design of this subset is | |
9677 | ||
9678 | @itemize @bullet | |
9679 | @item | |
9680 | That @value{GDBN} should provide basic literals and access to operations for | |
9681 | arithmetic, dereferencing, field selection, indexing, and subprogram calls, | |
9682 | leaving more sophisticated computations to subprograms written into the | |
9683 | program (which therefore may be called from @value{GDBN}). | |
9684 | ||
9685 | @item | |
9686 | That type safety and strict adherence to Ada language restrictions | |
9687 | are not particularly important to the @value{GDBN} user. | |
9688 | ||
9689 | @item | |
9690 | That brevity is important to the @value{GDBN} user. | |
9691 | @end itemize | |
9692 | ||
9693 | Thus, for brevity, the debugger acts as if there were | |
9694 | implicit @code{with} and @code{use} clauses in effect for all user-written | |
9695 | packages, making it unnecessary to fully qualify most names with | |
9696 | their packages, regardless of context. Where this causes ambiguity, | |
9697 | @value{GDBN} asks the user's intent. | |
9698 | ||
9699 | The debugger will start in Ada mode if it detects an Ada main program. | |
9700 | As for other languages, it will enter Ada mode when stopped in a program that | |
9701 | was translated from an Ada source file. | |
9702 | ||
9703 | While in Ada mode, you may use `@t{--}' for comments. This is useful | |
9704 | mostly for documenting command files. The standard @value{GDBN} comment | |
9705 | (@samp{#}) still works at the beginning of a line in Ada mode, but not in the | |
9706 | middle (to allow based literals). | |
9707 | ||
9708 | The debugger supports limited overloading. Given a subprogram call in which | |
9709 | the function symbol has multiple definitions, it will use the number of | |
9710 | actual parameters and some information about their types to attempt to narrow | |
9711 | the set of definitions. It also makes very limited use of context, preferring | |
9712 | procedures to functions in the context of the @code{call} command, and | |
9713 | functions to procedures elsewhere. | |
9714 | ||
9715 | @node Omissions from Ada | |
9716 | @subsubsection Omissions from Ada | |
9717 | @cindex Ada, omissions from | |
9718 | ||
9719 | Here are the notable omissions from the subset: | |
9720 | ||
9721 | @itemize @bullet | |
9722 | @item | |
9723 | Only a subset of the attributes are supported: | |
9724 | ||
9725 | @itemize @minus | |
9726 | @item | |
9727 | @t{'First}, @t{'Last}, and @t{'Length} | |
9728 | on array objects (not on types and subtypes). | |
9729 | ||
9730 | @item | |
9731 | @t{'Min} and @t{'Max}. | |
9732 | ||
9733 | @item | |
9734 | @t{'Pos} and @t{'Val}. | |
9735 | ||
9736 | @item | |
9737 | @t{'Tag}. | |
9738 | ||
9739 | @item | |
9740 | @t{'Range} on array objects (not subtypes), but only as the right | |
9741 | operand of the membership (@code{in}) operator. | |
9742 | ||
9743 | @item | |
9744 | @t{'Access}, @t{'Unchecked_Access}, and | |
9745 | @t{'Unrestricted_Access} (a GNAT extension). | |
9746 | ||
9747 | @item | |
9748 | @t{'Address}. | |
9749 | @end itemize | |
9750 | ||
9751 | @item | |
9752 | The names in | |
9753 | @code{Characters.Latin_1} are not available and | |
9754 | concatenation is not implemented. Thus, escape characters in strings are | |
9755 | not currently available. | |
9756 | ||
9757 | @item | |
9758 | Equality tests (@samp{=} and @samp{/=}) on arrays test for bitwise | |
9759 | equality of representations. They will generally work correctly | |
9760 | for strings and arrays whose elements have integer or enumeration types. | |
9761 | They may not work correctly for arrays whose element | |
9762 | types have user-defined equality, for arrays of real values | |
9763 | (in particular, IEEE-conformant floating point, because of negative | |
9764 | zeroes and NaNs), and for arrays whose elements contain unused bits with | |
9765 | indeterminate values. | |
9766 | ||
9767 | @item | |
9768 | The other component-by-component array operations (@code{and}, @code{or}, | |
9769 | @code{xor}, @code{not}, and relational tests other than equality) | |
9770 | are not implemented. | |
9771 | ||
9772 | @item | |
9773 | There are no record or array aggregates. | |
9774 | ||
9775 | @item | |
9776 | Calls to dispatching subprograms are not implemented. | |
9777 | ||
9778 | @item | |
9779 | The overloading algorithm is much more limited (i.e., less selective) | |
9780 | than that of real Ada. It makes only limited use of the context in which a subexpression | |
9781 | appears to resolve its meaning, and it is much looser in its rules for allowing | |
9782 | type matches. As a result, some function calls will be ambiguous, and the user | |
9783 | will be asked to choose the proper resolution. | |
9784 | ||
9785 | @item | |
9786 | The @code{new} operator is not implemented. | |
9787 | ||
9788 | @item | |
9789 | Entry calls are not implemented. | |
9790 | ||
9791 | @item | |
9792 | Aside from printing, arithmetic operations on the native VAX floating-point | |
9793 | formats are not supported. | |
9794 | ||
9795 | @item | |
9796 | It is not possible to slice a packed array. | |
9797 | @end itemize | |
9798 | ||
9799 | @node Additions to Ada | |
9800 | @subsubsection Additions to Ada | |
9801 | @cindex Ada, deviations from | |
9802 | ||
9803 | As it does for other languages, @value{GDBN} makes certain generic | |
9804 | extensions to Ada (@pxref{Expressions}): | |
9805 | ||
9806 | @itemize @bullet | |
9807 | @item | |
9808 | If the expression @var{E} is a variable residing in memory | |
9809 | (typically a local variable or array element) and @var{N} is | |
9810 | a positive integer, then @code{@var{E}@@@var{N}} displays the values of | |
9811 | @var{E} and the @var{N}-1 adjacent variables following it in memory as an array. | |
9812 | In Ada, this operator is generally not necessary, since its prime use | |
9813 | is in displaying parts of an array, and slicing will usually do this in Ada. | |
9814 | However, there are occasional uses when debugging programs | |
9815 | in which certain debugging information has been optimized away. | |
9816 | ||
9817 | @item | |
9818 | @code{@var{B}::@var{var}} means ``the variable named @var{var} that appears | |
9819 | in function or file @var{B}.'' When @var{B} is a file name, you must typically | |
9820 | surround it in single quotes. | |
9821 | ||
9822 | @item | |
9823 | The expression @code{@{@var{type}@} @var{addr}} means ``the variable of type | |
9824 | @var{type} that appears at address @var{addr}.'' | |
9825 | ||
9826 | @item | |
9827 | A name starting with @samp{$} is a convenience variable | |
9828 | (@pxref{Convenience Vars}) or a machine register (@pxref{Registers}). | |
9829 | @end itemize | |
9830 | ||
9831 | In addition, @value{GDBN} provides a few other shortcuts and outright additions specific | |
9832 | to Ada: | |
9833 | ||
9834 | @itemize @bullet | |
9835 | @item | |
9836 | The assignment statement is allowed as an expression, returning | |
9837 | its right-hand operand as its value. Thus, you may enter | |
9838 | ||
9839 | @smallexample | |
9840 | set x := y + 3 | |
9841 | print A(tmp := y + 1) | |
9842 | @end smallexample | |
9843 | ||
9844 | @item | |
9845 | The semicolon is allowed as an ``operator,'' returning as its value | |
9846 | the value of its right-hand operand. | |
9847 | This allows, for example, | |
9848 | complex conditional breaks: | |
9849 | ||
9850 | @smallexample | |
9851 | break f | |
9852 | condition 1 (report(i); k += 1; A(k) > 100) | |
9853 | @end smallexample | |
9854 | ||
9855 | @item | |
9856 | Rather than use catenation and symbolic character names to introduce special | |
9857 | characters into strings, one may instead use a special bracket notation, | |
9858 | which is also used to print strings. A sequence of characters of the form | |
9859 | @samp{["@var{XX}"]} within a string or character literal denotes the | |
9860 | (single) character whose numeric encoding is @var{XX} in hexadecimal. The | |
9861 | sequence of characters @samp{["""]} also denotes a single quotation mark | |
9862 | in strings. For example, | |
9863 | @smallexample | |
9864 | "One line.["0a"]Next line.["0a"]" | |
9865 | @end smallexample | |
9866 | @noindent | |
9867 | contains an ASCII newline character (@code{Ada.Characters.Latin_1.LF}) after each | |
9868 | period. | |
9869 | ||
9870 | @item | |
9871 | The subtype used as a prefix for the attributes @t{'Pos}, @t{'Min}, and | |
9872 | @t{'Max} is optional (and is ignored in any case). For example, it is valid | |
9873 | to write | |
9874 | ||
9875 | @smallexample | |
9876 | print 'max(x, y) | |
9877 | @end smallexample | |
9878 | ||
9879 | @item | |
9880 | When printing arrays, @value{GDBN} uses positional notation when the | |
9881 | array has a lower bound of 1, and uses a modified named notation otherwise. | |
9882 | For example, a one-dimensional array of three integers with a lower bound of 3 might print as | |
9883 | ||
9884 | @smallexample | |
9885 | (3 => 10, 17, 1) | |
9886 | @end smallexample | |
9887 | ||
9888 | @noindent | |
9889 | That is, in contrast to valid Ada, only the first component has a @code{=>} | |
9890 | clause. | |
9891 | ||
9892 | @item | |
9893 | You may abbreviate attributes in expressions with any unique, | |
9894 | multi-character subsequence of | |
9895 | their names (an exact match gets preference). | |
9896 | For example, you may use @t{a'len}, @t{a'gth}, or @t{a'lh} | |
9897 | in place of @t{a'length}. | |
9898 | ||
9899 | @item | |
9900 | @cindex quoting Ada internal identifiers | |
9901 | Since Ada is case-insensitive, the debugger normally maps identifiers you type | |
9902 | to lower case. The GNAT compiler uses upper-case characters for | |
9903 | some of its internal identifiers, which are normally of no interest to users. | |
9904 | For the rare occasions when you actually have to look at them, | |
9905 | enclose them in angle brackets to avoid the lower-case mapping. | |
9906 | For example, | |
9907 | @smallexample | |
9908 | @value{GDBP} print <JMPBUF_SAVE>[0] | |
9909 | @end smallexample | |
9910 | ||
9911 | @item | |
9912 | Printing an object of class-wide type or dereferencing an | |
9913 | access-to-class-wide value will display all the components of the object's | |
9914 | specific type (as indicated by its run-time tag). Likewise, component | |
9915 | selection on such a value will operate on the specific type of the | |
9916 | object. | |
9917 | ||
9918 | @end itemize | |
9919 | ||
9920 | @node Stopping Before Main Program | |
9921 | @subsubsection Stopping at the Very Beginning | |
9922 | ||
9923 | @cindex breakpointing Ada elaboration code | |
9924 | It is sometimes necessary to debug the program during elaboration, and | |
9925 | before reaching the main procedure. | |
9926 | As defined in the Ada Reference | |
9927 | Manual, the elaboration code is invoked from a procedure called | |
9928 | @code{adainit}. To run your program up to the beginning of | |
9929 | elaboration, simply use the following two commands: | |
9930 | @code{tbreak adainit} and @code{run}. | |
9931 | ||
9932 | @node Ada Glitches | |
9933 | @subsubsection Known Peculiarities of Ada Mode | |
9934 | @cindex Ada, problems | |
9935 | ||
9936 | Besides the omissions listed previously (@pxref{Omissions from Ada}), | |
9937 | we know of several problems with and limitations of Ada mode in | |
9938 | @value{GDBN}, | |
9939 | some of which will be fixed with planned future releases of the debugger | |
9940 | and the GNU Ada compiler. | |
9941 | ||
9942 | @itemize @bullet | |
9943 | @item | |
9944 | Currently, the debugger | |
9945 | has insufficient information to determine whether certain pointers represent | |
9946 | pointers to objects or the objects themselves. | |
9947 | Thus, the user may have to tack an extra @code{.all} after an expression | |
9948 | to get it printed properly. | |
9949 | ||
9950 | @item | |
9951 | Static constants that the compiler chooses not to materialize as objects in | |
9952 | storage are invisible to the debugger. | |
9953 | ||
9954 | @item | |
9955 | Named parameter associations in function argument lists are ignored (the | |
9956 | argument lists are treated as positional). | |
9957 | ||
9958 | @item | |
9959 | Many useful library packages are currently invisible to the debugger. | |
9960 | ||
9961 | @item | |
9962 | Fixed-point arithmetic, conversions, input, and output is carried out using | |
9963 | floating-point arithmetic, and may give results that only approximate those on | |
9964 | the host machine. | |
9965 | ||
9966 | @item | |
9967 | The type of the @t{'Address} attribute may not be @code{System.Address}. | |
9968 | ||
9969 | @item | |
9970 | The GNAT compiler never generates the prefix @code{Standard} for any of | |
9971 | the standard symbols defined by the Ada language. @value{GDBN} knows about | |
9972 | this: it will strip the prefix from names when you use it, and will never | |
9973 | look for a name you have so qualified among local symbols, nor match against | |
9974 | symbols in other packages or subprograms. If you have | |
9975 | defined entities anywhere in your program other than parameters and | |
9976 | local variables whose simple names match names in @code{Standard}, | |
9977 | GNAT's lack of qualification here can cause confusion. When this happens, | |
9978 | you can usually resolve the confusion | |
9979 | by qualifying the problematic names with package | |
9980 | @code{Standard} explicitly. | |
9981 | @end itemize | |
9982 | ||
4e562065 JB |
9983 | @node Unsupported languages |
9984 | @section Unsupported languages | |
9985 | ||
9986 | @cindex unsupported languages | |
9987 | @cindex minimal language | |
9988 | In addition to the other fully-supported programming languages, | |
9989 | @value{GDBN} also provides a pseudo-language, called @code{minimal}. | |
9990 | It does not represent a real programming language, but provides a set | |
9991 | of capabilities close to what the C or assembly languages provide. | |
9992 | This should allow most simple operations to be performed while debugging | |
9993 | an application that uses a language currently not supported by @value{GDBN}. | |
9994 | ||
9995 | If the language is set to @code{auto}, @value{GDBN} will automatically | |
9996 | select this language if the current frame corresponds to an unsupported | |
9997 | language. | |
9998 | ||
6d2ebf8b | 9999 | @node Symbols |
c906108c SS |
10000 | @chapter Examining the Symbol Table |
10001 | ||
d4f3574e | 10002 | The commands described in this chapter allow you to inquire about the |
c906108c SS |
10003 | symbols (names of variables, functions and types) defined in your |
10004 | program. This information is inherent in the text of your program and | |
10005 | does not change as your program executes. @value{GDBN} finds it in your | |
10006 | program's symbol table, in the file indicated when you started @value{GDBN} | |
10007 | (@pxref{File Options, ,Choosing files}), or by one of the | |
10008 | file-management commands (@pxref{Files, ,Commands to specify files}). | |
10009 | ||
10010 | @cindex symbol names | |
10011 | @cindex names of symbols | |
10012 | @cindex quoting names | |
10013 | Occasionally, you may need to refer to symbols that contain unusual | |
10014 | characters, which @value{GDBN} ordinarily treats as word delimiters. The | |
10015 | most frequent case is in referring to static variables in other | |
10016 | source files (@pxref{Variables,,Program variables}). File names | |
10017 | are recorded in object files as debugging symbols, but @value{GDBN} would | |
10018 | ordinarily parse a typical file name, like @file{foo.c}, as the three words | |
10019 | @samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize | |
10020 | @samp{foo.c} as a single symbol, enclose it in single quotes; for example, | |
10021 | ||
474c8240 | 10022 | @smallexample |
c906108c | 10023 | p 'foo.c'::x |
474c8240 | 10024 | @end smallexample |
c906108c SS |
10025 | |
10026 | @noindent | |
10027 | looks up the value of @code{x} in the scope of the file @file{foo.c}. | |
10028 | ||
10029 | @table @code | |
a8f24a35 EZ |
10030 | @cindex case-insensitive symbol names |
10031 | @cindex case sensitivity in symbol names | |
10032 | @kindex set case-sensitive | |
10033 | @item set case-sensitive on | |
10034 | @itemx set case-sensitive off | |
10035 | @itemx set case-sensitive auto | |
10036 | Normally, when @value{GDBN} looks up symbols, it matches their names | |
10037 | with case sensitivity determined by the current source language. | |
10038 | Occasionally, you may wish to control that. The command @code{set | |
10039 | case-sensitive} lets you do that by specifying @code{on} for | |
10040 | case-sensitive matches or @code{off} for case-insensitive ones. If | |
10041 | you specify @code{auto}, case sensitivity is reset to the default | |
10042 | suitable for the source language. The default is case-sensitive | |
10043 | matches for all languages except for Fortran, for which the default is | |
10044 | case-insensitive matches. | |
10045 | ||
9c16f35a EZ |
10046 | @kindex show case-sensitive |
10047 | @item show case-sensitive | |
a8f24a35 EZ |
10048 | This command shows the current setting of case sensitivity for symbols |
10049 | lookups. | |
10050 | ||
c906108c | 10051 | @kindex info address |
b37052ae | 10052 | @cindex address of a symbol |
c906108c SS |
10053 | @item info address @var{symbol} |
10054 | Describe where the data for @var{symbol} is stored. For a register | |
10055 | variable, this says which register it is kept in. For a non-register | |
10056 | local variable, this prints the stack-frame offset at which the variable | |
10057 | is always stored. | |
10058 | ||
10059 | Note the contrast with @samp{print &@var{symbol}}, which does not work | |
10060 | at all for a register variable, and for a stack local variable prints | |
10061 | the exact address of the current instantiation of the variable. | |
10062 | ||
3d67e040 | 10063 | @kindex info symbol |
b37052ae | 10064 | @cindex symbol from address |
9c16f35a | 10065 | @cindex closest symbol and offset for an address |
3d67e040 EZ |
10066 | @item info symbol @var{addr} |
10067 | Print the name of a symbol which is stored at the address @var{addr}. | |
10068 | If no symbol is stored exactly at @var{addr}, @value{GDBN} prints the | |
10069 | nearest symbol and an offset from it: | |
10070 | ||
474c8240 | 10071 | @smallexample |
3d67e040 EZ |
10072 | (@value{GDBP}) info symbol 0x54320 |
10073 | _initialize_vx + 396 in section .text | |
474c8240 | 10074 | @end smallexample |
3d67e040 EZ |
10075 | |
10076 | @noindent | |
10077 | This is the opposite of the @code{info address} command. You can use | |
10078 | it to find out the name of a variable or a function given its address. | |
10079 | ||
c906108c | 10080 | @kindex whatis |
d4f3574e SS |
10081 | @item whatis @var{expr} |
10082 | Print the data type of expression @var{expr}. @var{expr} is not | |
c906108c SS |
10083 | actually evaluated, and any side-effecting operations (such as |
10084 | assignments or function calls) inside it do not take place. | |
10085 | @xref{Expressions, ,Expressions}. | |
10086 | ||
10087 | @item whatis | |
10088 | Print the data type of @code{$}, the last value in the value history. | |
10089 | ||
10090 | @kindex ptype | |
10091 | @item ptype @var{typename} | |
10092 | Print a description of data type @var{typename}. @var{typename} may be | |
7a292a7a SS |
10093 | the name of a type, or for C code it may have the form @samp{class |
10094 | @var{class-name}}, @samp{struct @var{struct-tag}}, @samp{union | |
10095 | @var{union-tag}} or @samp{enum @var{enum-tag}}. | |
c906108c | 10096 | |
d4f3574e | 10097 | @item ptype @var{expr} |
c906108c | 10098 | @itemx ptype |
d4f3574e | 10099 | Print a description of the type of expression @var{expr}. @code{ptype} |
c906108c SS |
10100 | differs from @code{whatis} by printing a detailed description, instead |
10101 | of just the name of the type. | |
10102 | ||
10103 | For example, for this variable declaration: | |
10104 | ||
474c8240 | 10105 | @smallexample |
c906108c | 10106 | struct complex @{double real; double imag;@} v; |
474c8240 | 10107 | @end smallexample |
c906108c SS |
10108 | |
10109 | @noindent | |
10110 | the two commands give this output: | |
10111 | ||
474c8240 | 10112 | @smallexample |
c906108c SS |
10113 | @group |
10114 | (@value{GDBP}) whatis v | |
10115 | type = struct complex | |
10116 | (@value{GDBP}) ptype v | |
10117 | type = struct complex @{ | |
10118 | double real; | |
10119 | double imag; | |
10120 | @} | |
10121 | @end group | |
474c8240 | 10122 | @end smallexample |
c906108c SS |
10123 | |
10124 | @noindent | |
10125 | As with @code{whatis}, using @code{ptype} without an argument refers to | |
10126 | the type of @code{$}, the last value in the value history. | |
10127 | ||
ab1adacd EZ |
10128 | @cindex incomplete type |
10129 | Sometimes, programs use opaque data types or incomplete specifications | |
10130 | of complex data structure. If the debug information included in the | |
10131 | program does not allow @value{GDBN} to display a full declaration of | |
10132 | the data type, it will say @samp{<incomplete type>}. For example, | |
10133 | given these declarations: | |
10134 | ||
10135 | @smallexample | |
10136 | struct foo; | |
10137 | struct foo *fooptr; | |
10138 | @end smallexample | |
10139 | ||
10140 | @noindent | |
10141 | but no definition for @code{struct foo} itself, @value{GDBN} will say: | |
10142 | ||
10143 | @smallexample | |
10144 | (gdb) ptype foo | |
10145 | $1 = <incomplete type> | |
10146 | @end smallexample | |
10147 | ||
10148 | @noindent | |
10149 | ``Incomplete type'' is C terminology for data types that are not | |
10150 | completely specified. | |
10151 | ||
c906108c SS |
10152 | @kindex info types |
10153 | @item info types @var{regexp} | |
10154 | @itemx info types | |
09d4efe1 EZ |
10155 | Print a brief description of all types whose names match the regular |
10156 | expression @var{regexp} (or all types in your program, if you supply | |
10157 | no argument). Each complete typename is matched as though it were a | |
10158 | complete line; thus, @samp{i type value} gives information on all | |
10159 | types in your program whose names include the string @code{value}, but | |
10160 | @samp{i type ^value$} gives information only on types whose complete | |
10161 | name is @code{value}. | |
c906108c SS |
10162 | |
10163 | This command differs from @code{ptype} in two ways: first, like | |
10164 | @code{whatis}, it does not print a detailed description; second, it | |
10165 | lists all source files where a type is defined. | |
10166 | ||
b37052ae EZ |
10167 | @kindex info scope |
10168 | @cindex local variables | |
09d4efe1 | 10169 | @item info scope @var{location} |
b37052ae | 10170 | List all the variables local to a particular scope. This command |
09d4efe1 EZ |
10171 | accepts a @var{location} argument---a function name, a source line, or |
10172 | an address preceded by a @samp{*}, and prints all the variables local | |
10173 | to the scope defined by that location. For example: | |
b37052ae EZ |
10174 | |
10175 | @smallexample | |
10176 | (@value{GDBP}) @b{info scope command_line_handler} | |
10177 | Scope for command_line_handler: | |
10178 | Symbol rl is an argument at stack/frame offset 8, length 4. | |
10179 | Symbol linebuffer is in static storage at address 0x150a18, length 4. | |
10180 | Symbol linelength is in static storage at address 0x150a1c, length 4. | |
10181 | Symbol p is a local variable in register $esi, length 4. | |
10182 | Symbol p1 is a local variable in register $ebx, length 4. | |
10183 | Symbol nline is a local variable in register $edx, length 4. | |
10184 | Symbol repeat is a local variable at frame offset -8, length 4. | |
10185 | @end smallexample | |
10186 | ||
f5c37c66 EZ |
10187 | @noindent |
10188 | This command is especially useful for determining what data to collect | |
10189 | during a @dfn{trace experiment}, see @ref{Tracepoint Actions, | |
10190 | collect}. | |
10191 | ||
c906108c SS |
10192 | @kindex info source |
10193 | @item info source | |
919d772c JB |
10194 | Show information about the current source file---that is, the source file for |
10195 | the function containing the current point of execution: | |
10196 | @itemize @bullet | |
10197 | @item | |
10198 | the name of the source file, and the directory containing it, | |
10199 | @item | |
10200 | the directory it was compiled in, | |
10201 | @item | |
10202 | its length, in lines, | |
10203 | @item | |
10204 | which programming language it is written in, | |
10205 | @item | |
10206 | whether the executable includes debugging information for that file, and | |
10207 | if so, what format the information is in (e.g., STABS, Dwarf 2, etc.), and | |
10208 | @item | |
10209 | whether the debugging information includes information about | |
10210 | preprocessor macros. | |
10211 | @end itemize | |
10212 | ||
c906108c SS |
10213 | |
10214 | @kindex info sources | |
10215 | @item info sources | |
10216 | Print the names of all source files in your program for which there is | |
10217 | debugging information, organized into two lists: files whose symbols | |
10218 | have already been read, and files whose symbols will be read when needed. | |
10219 | ||
10220 | @kindex info functions | |
10221 | @item info functions | |
10222 | Print the names and data types of all defined functions. | |
10223 | ||
10224 | @item info functions @var{regexp} | |
10225 | Print the names and data types of all defined functions | |
10226 | whose names contain a match for regular expression @var{regexp}. | |
10227 | Thus, @samp{info fun step} finds all functions whose names | |
10228 | include @code{step}; @samp{info fun ^step} finds those whose names | |
b383017d RM |
10229 | start with @code{step}. If a function name contains characters |
10230 | that conflict with the regular expression language (eg. | |
1c5dfdad | 10231 | @samp{operator*()}), they may be quoted with a backslash. |
c906108c SS |
10232 | |
10233 | @kindex info variables | |
10234 | @item info variables | |
10235 | Print the names and data types of all variables that are declared | |
6ca652b0 | 10236 | outside of functions (i.e.@: excluding local variables). |
c906108c SS |
10237 | |
10238 | @item info variables @var{regexp} | |
10239 | Print the names and data types of all variables (except for local | |
10240 | variables) whose names contain a match for regular expression | |
10241 | @var{regexp}. | |
10242 | ||
b37303ee | 10243 | @kindex info classes |
721c2651 | 10244 | @cindex Objective-C, classes and selectors |
b37303ee AF |
10245 | @item info classes |
10246 | @itemx info classes @var{regexp} | |
10247 | Display all Objective-C classes in your program, or | |
10248 | (with the @var{regexp} argument) all those matching a particular regular | |
10249 | expression. | |
10250 | ||
10251 | @kindex info selectors | |
10252 | @item info selectors | |
10253 | @itemx info selectors @var{regexp} | |
10254 | Display all Objective-C selectors in your program, or | |
10255 | (with the @var{regexp} argument) all those matching a particular regular | |
10256 | expression. | |
10257 | ||
c906108c SS |
10258 | @ignore |
10259 | This was never implemented. | |
10260 | @kindex info methods | |
10261 | @item info methods | |
10262 | @itemx info methods @var{regexp} | |
10263 | The @code{info methods} command permits the user to examine all defined | |
b37052ae EZ |
10264 | methods within C@t{++} program, or (with the @var{regexp} argument) a |
10265 | specific set of methods found in the various C@t{++} classes. Many | |
10266 | C@t{++} classes provide a large number of methods. Thus, the output | |
c906108c SS |
10267 | from the @code{ptype} command can be overwhelming and hard to use. The |
10268 | @code{info-methods} command filters the methods, printing only those | |
10269 | which match the regular-expression @var{regexp}. | |
10270 | @end ignore | |
10271 | ||
c906108c SS |
10272 | @cindex reloading symbols |
10273 | Some systems allow individual object files that make up your program to | |
7a292a7a SS |
10274 | be replaced without stopping and restarting your program. For example, |
10275 | in VxWorks you can simply recompile a defective object file and keep on | |
10276 | running. If you are running on one of these systems, you can allow | |
10277 | @value{GDBN} to reload the symbols for automatically relinked modules: | |
c906108c SS |
10278 | |
10279 | @table @code | |
10280 | @kindex set symbol-reloading | |
10281 | @item set symbol-reloading on | |
10282 | Replace symbol definitions for the corresponding source file when an | |
10283 | object file with a particular name is seen again. | |
10284 | ||
10285 | @item set symbol-reloading off | |
6d2ebf8b SS |
10286 | Do not replace symbol definitions when encountering object files of the |
10287 | same name more than once. This is the default state; if you are not | |
10288 | running on a system that permits automatic relinking of modules, you | |
10289 | should leave @code{symbol-reloading} off, since otherwise @value{GDBN} | |
10290 | may discard symbols when linking large programs, that may contain | |
10291 | several modules (from different directories or libraries) with the same | |
10292 | name. | |
c906108c SS |
10293 | |
10294 | @kindex show symbol-reloading | |
10295 | @item show symbol-reloading | |
10296 | Show the current @code{on} or @code{off} setting. | |
10297 | @end table | |
c906108c | 10298 | |
9c16f35a | 10299 | @cindex opaque data types |
c906108c SS |
10300 | @kindex set opaque-type-resolution |
10301 | @item set opaque-type-resolution on | |
10302 | Tell @value{GDBN} to resolve opaque types. An opaque type is a type | |
10303 | declared as a pointer to a @code{struct}, @code{class}, or | |
10304 | @code{union}---for example, @code{struct MyType *}---that is used in one | |
10305 | source file although the full declaration of @code{struct MyType} is in | |
10306 | another source file. The default is on. | |
10307 | ||
10308 | A change in the setting of this subcommand will not take effect until | |
10309 | the next time symbols for a file are loaded. | |
10310 | ||
10311 | @item set opaque-type-resolution off | |
10312 | Tell @value{GDBN} not to resolve opaque types. In this case, the type | |
10313 | is printed as follows: | |
10314 | @smallexample | |
10315 | @{<no data fields>@} | |
10316 | @end smallexample | |
10317 | ||
10318 | @kindex show opaque-type-resolution | |
10319 | @item show opaque-type-resolution | |
10320 | Show whether opaque types are resolved or not. | |
c906108c SS |
10321 | |
10322 | @kindex maint print symbols | |
10323 | @cindex symbol dump | |
10324 | @kindex maint print psymbols | |
10325 | @cindex partial symbol dump | |
10326 | @item maint print symbols @var{filename} | |
10327 | @itemx maint print psymbols @var{filename} | |
10328 | @itemx maint print msymbols @var{filename} | |
10329 | Write a dump of debugging symbol data into the file @var{filename}. | |
10330 | These commands are used to debug the @value{GDBN} symbol-reading code. Only | |
10331 | symbols with debugging data are included. If you use @samp{maint print | |
10332 | symbols}, @value{GDBN} includes all the symbols for which it has already | |
10333 | collected full details: that is, @var{filename} reflects symbols for | |
10334 | only those files whose symbols @value{GDBN} has read. You can use the | |
10335 | command @code{info sources} to find out which files these are. If you | |
10336 | use @samp{maint print psymbols} instead, the dump shows information about | |
10337 | symbols that @value{GDBN} only knows partially---that is, symbols defined in | |
10338 | files that @value{GDBN} has skimmed, but not yet read completely. Finally, | |
10339 | @samp{maint print msymbols} dumps just the minimal symbol information | |
10340 | required for each object file from which @value{GDBN} has read some symbols. | |
10341 | @xref{Files, ,Commands to specify files}, for a discussion of how | |
10342 | @value{GDBN} reads symbols (in the description of @code{symbol-file}). | |
44ea7b70 | 10343 | |
5e7b2f39 JB |
10344 | @kindex maint info symtabs |
10345 | @kindex maint info psymtabs | |
44ea7b70 JB |
10346 | @cindex listing @value{GDBN}'s internal symbol tables |
10347 | @cindex symbol tables, listing @value{GDBN}'s internal | |
10348 | @cindex full symbol tables, listing @value{GDBN}'s internal | |
10349 | @cindex partial symbol tables, listing @value{GDBN}'s internal | |
5e7b2f39 JB |
10350 | @item maint info symtabs @r{[} @var{regexp} @r{]} |
10351 | @itemx maint info psymtabs @r{[} @var{regexp} @r{]} | |
44ea7b70 JB |
10352 | |
10353 | List the @code{struct symtab} or @code{struct partial_symtab} | |
10354 | structures whose names match @var{regexp}. If @var{regexp} is not | |
10355 | given, list them all. The output includes expressions which you can | |
10356 | copy into a @value{GDBN} debugging this one to examine a particular | |
10357 | structure in more detail. For example: | |
10358 | ||
10359 | @smallexample | |
5e7b2f39 | 10360 | (@value{GDBP}) maint info psymtabs dwarf2read |
44ea7b70 JB |
10361 | @{ objfile /home/gnu/build/gdb/gdb |
10362 | ((struct objfile *) 0x82e69d0) | |
b383017d | 10363 | @{ psymtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
10364 | ((struct partial_symtab *) 0x8474b10) |
10365 | readin no | |
10366 | fullname (null) | |
10367 | text addresses 0x814d3c8 -- 0x8158074 | |
10368 | globals (* (struct partial_symbol **) 0x8507a08 @@ 9) | |
10369 | statics (* (struct partial_symbol **) 0x40e95b78 @@ 2882) | |
10370 | dependencies (none) | |
10371 | @} | |
10372 | @} | |
5e7b2f39 | 10373 | (@value{GDBP}) maint info symtabs |
44ea7b70 JB |
10374 | (@value{GDBP}) |
10375 | @end smallexample | |
10376 | @noindent | |
10377 | We see that there is one partial symbol table whose filename contains | |
10378 | the string @samp{dwarf2read}, belonging to the @samp{gdb} executable; | |
10379 | and we see that @value{GDBN} has not read in any symtabs yet at all. | |
10380 | If we set a breakpoint on a function, that will cause @value{GDBN} to | |
10381 | read the symtab for the compilation unit containing that function: | |
10382 | ||
10383 | @smallexample | |
10384 | (@value{GDBP}) break dwarf2_psymtab_to_symtab | |
10385 | Breakpoint 1 at 0x814e5da: file /home/gnu/src/gdb/dwarf2read.c, | |
10386 | line 1574. | |
5e7b2f39 | 10387 | (@value{GDBP}) maint info symtabs |
b383017d | 10388 | @{ objfile /home/gnu/build/gdb/gdb |
44ea7b70 | 10389 | ((struct objfile *) 0x82e69d0) |
b383017d | 10390 | @{ symtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
10391 | ((struct symtab *) 0x86c1f38) |
10392 | dirname (null) | |
10393 | fullname (null) | |
10394 | blockvector ((struct blockvector *) 0x86c1bd0) (primary) | |
10395 | debugformat DWARF 2 | |
10396 | @} | |
10397 | @} | |
b383017d | 10398 | (@value{GDBP}) |
44ea7b70 | 10399 | @end smallexample |
c906108c SS |
10400 | @end table |
10401 | ||
44ea7b70 | 10402 | |
6d2ebf8b | 10403 | @node Altering |
c906108c SS |
10404 | @chapter Altering Execution |
10405 | ||
10406 | Once you think you have found an error in your program, you might want to | |
10407 | find out for certain whether correcting the apparent error would lead to | |
10408 | correct results in the rest of the run. You can find the answer by | |
10409 | experiment, using the @value{GDBN} features for altering execution of the | |
10410 | program. | |
10411 | ||
10412 | For example, you can store new values into variables or memory | |
7a292a7a SS |
10413 | locations, give your program a signal, restart it at a different |
10414 | address, or even return prematurely from a function. | |
c906108c SS |
10415 | |
10416 | @menu | |
10417 | * Assignment:: Assignment to variables | |
10418 | * Jumping:: Continuing at a different address | |
c906108c | 10419 | * Signaling:: Giving your program a signal |
c906108c SS |
10420 | * Returning:: Returning from a function |
10421 | * Calling:: Calling your program's functions | |
10422 | * Patching:: Patching your program | |
10423 | @end menu | |
10424 | ||
6d2ebf8b | 10425 | @node Assignment |
c906108c SS |
10426 | @section Assignment to variables |
10427 | ||
10428 | @cindex assignment | |
10429 | @cindex setting variables | |
10430 | To alter the value of a variable, evaluate an assignment expression. | |
10431 | @xref{Expressions, ,Expressions}. For example, | |
10432 | ||
474c8240 | 10433 | @smallexample |
c906108c | 10434 | print x=4 |
474c8240 | 10435 | @end smallexample |
c906108c SS |
10436 | |
10437 | @noindent | |
10438 | stores the value 4 into the variable @code{x}, and then prints the | |
5d161b24 | 10439 | value of the assignment expression (which is 4). |
c906108c SS |
10440 | @xref{Languages, ,Using @value{GDBN} with Different Languages}, for more |
10441 | information on operators in supported languages. | |
c906108c SS |
10442 | |
10443 | @kindex set variable | |
10444 | @cindex variables, setting | |
10445 | If you are not interested in seeing the value of the assignment, use the | |
10446 | @code{set} command instead of the @code{print} command. @code{set} is | |
10447 | really the same as @code{print} except that the expression's value is | |
10448 | not printed and is not put in the value history (@pxref{Value History, | |
10449 | ,Value history}). The expression is evaluated only for its effects. | |
10450 | ||
c906108c SS |
10451 | If the beginning of the argument string of the @code{set} command |
10452 | appears identical to a @code{set} subcommand, use the @code{set | |
10453 | variable} command instead of just @code{set}. This command is identical | |
10454 | to @code{set} except for its lack of subcommands. For example, if your | |
10455 | program has a variable @code{width}, you get an error if you try to set | |
10456 | a new value with just @samp{set width=13}, because @value{GDBN} has the | |
10457 | command @code{set width}: | |
10458 | ||
474c8240 | 10459 | @smallexample |
c906108c SS |
10460 | (@value{GDBP}) whatis width |
10461 | type = double | |
10462 | (@value{GDBP}) p width | |
10463 | $4 = 13 | |
10464 | (@value{GDBP}) set width=47 | |
10465 | Invalid syntax in expression. | |
474c8240 | 10466 | @end smallexample |
c906108c SS |
10467 | |
10468 | @noindent | |
10469 | The invalid expression, of course, is @samp{=47}. In | |
10470 | order to actually set the program's variable @code{width}, use | |
10471 | ||
474c8240 | 10472 | @smallexample |
c906108c | 10473 | (@value{GDBP}) set var width=47 |
474c8240 | 10474 | @end smallexample |
53a5351d | 10475 | |
c906108c SS |
10476 | Because the @code{set} command has many subcommands that can conflict |
10477 | with the names of program variables, it is a good idea to use the | |
10478 | @code{set variable} command instead of just @code{set}. For example, if | |
10479 | your program has a variable @code{g}, you run into problems if you try | |
10480 | to set a new value with just @samp{set g=4}, because @value{GDBN} has | |
10481 | the command @code{set gnutarget}, abbreviated @code{set g}: | |
10482 | ||
474c8240 | 10483 | @smallexample |
c906108c SS |
10484 | @group |
10485 | (@value{GDBP}) whatis g | |
10486 | type = double | |
10487 | (@value{GDBP}) p g | |
10488 | $1 = 1 | |
10489 | (@value{GDBP}) set g=4 | |
2df3850c | 10490 | (@value{GDBP}) p g |
c906108c SS |
10491 | $2 = 1 |
10492 | (@value{GDBP}) r | |
10493 | The program being debugged has been started already. | |
10494 | Start it from the beginning? (y or n) y | |
10495 | Starting program: /home/smith/cc_progs/a.out | |
6d2ebf8b SS |
10496 | "/home/smith/cc_progs/a.out": can't open to read symbols: |
10497 | Invalid bfd target. | |
c906108c SS |
10498 | (@value{GDBP}) show g |
10499 | The current BFD target is "=4". | |
10500 | @end group | |
474c8240 | 10501 | @end smallexample |
c906108c SS |
10502 | |
10503 | @noindent | |
10504 | The program variable @code{g} did not change, and you silently set the | |
10505 | @code{gnutarget} to an invalid value. In order to set the variable | |
10506 | @code{g}, use | |
10507 | ||
474c8240 | 10508 | @smallexample |
c906108c | 10509 | (@value{GDBP}) set var g=4 |
474c8240 | 10510 | @end smallexample |
c906108c SS |
10511 | |
10512 | @value{GDBN} allows more implicit conversions in assignments than C; you can | |
10513 | freely store an integer value into a pointer variable or vice versa, | |
10514 | and you can convert any structure to any other structure that is the | |
10515 | same length or shorter. | |
10516 | @comment FIXME: how do structs align/pad in these conversions? | |
10517 | @comment /doc@cygnus.com 18dec1990 | |
10518 | ||
10519 | To store values into arbitrary places in memory, use the @samp{@{@dots{}@}} | |
10520 | construct to generate a value of specified type at a specified address | |
10521 | (@pxref{Expressions, ,Expressions}). For example, @code{@{int@}0x83040} refers | |
10522 | to memory location @code{0x83040} as an integer (which implies a certain size | |
10523 | and representation in memory), and | |
10524 | ||
474c8240 | 10525 | @smallexample |
c906108c | 10526 | set @{int@}0x83040 = 4 |
474c8240 | 10527 | @end smallexample |
c906108c SS |
10528 | |
10529 | @noindent | |
10530 | stores the value 4 into that memory location. | |
10531 | ||
6d2ebf8b | 10532 | @node Jumping |
c906108c SS |
10533 | @section Continuing at a different address |
10534 | ||
10535 | Ordinarily, when you continue your program, you do so at the place where | |
10536 | it stopped, with the @code{continue} command. You can instead continue at | |
10537 | an address of your own choosing, with the following commands: | |
10538 | ||
10539 | @table @code | |
10540 | @kindex jump | |
10541 | @item jump @var{linespec} | |
10542 | Resume execution at line @var{linespec}. Execution stops again | |
10543 | immediately if there is a breakpoint there. @xref{List, ,Printing | |
10544 | source lines}, for a description of the different forms of | |
10545 | @var{linespec}. It is common practice to use the @code{tbreak} command | |
10546 | in conjunction with @code{jump}. @xref{Set Breaks, ,Setting | |
10547 | breakpoints}. | |
10548 | ||
10549 | The @code{jump} command does not change the current stack frame, or | |
10550 | the stack pointer, or the contents of any memory location or any | |
10551 | register other than the program counter. If line @var{linespec} is in | |
10552 | a different function from the one currently executing, the results may | |
10553 | be bizarre if the two functions expect different patterns of arguments or | |
10554 | of local variables. For this reason, the @code{jump} command requests | |
10555 | confirmation if the specified line is not in the function currently | |
10556 | executing. However, even bizarre results are predictable if you are | |
10557 | well acquainted with the machine-language code of your program. | |
10558 | ||
10559 | @item jump *@var{address} | |
10560 | Resume execution at the instruction at address @var{address}. | |
10561 | @end table | |
10562 | ||
c906108c | 10563 | @c Doesn't work on HP-UX; have to set $pcoqh and $pcoqt. |
53a5351d JM |
10564 | On many systems, you can get much the same effect as the @code{jump} |
10565 | command by storing a new value into the register @code{$pc}. The | |
10566 | difference is that this does not start your program running; it only | |
10567 | changes the address of where it @emph{will} run when you continue. For | |
10568 | example, | |
c906108c | 10569 | |
474c8240 | 10570 | @smallexample |
c906108c | 10571 | set $pc = 0x485 |
474c8240 | 10572 | @end smallexample |
c906108c SS |
10573 | |
10574 | @noindent | |
10575 | makes the next @code{continue} command or stepping command execute at | |
10576 | address @code{0x485}, rather than at the address where your program stopped. | |
10577 | @xref{Continuing and Stepping, ,Continuing and stepping}. | |
c906108c SS |
10578 | |
10579 | The most common occasion to use the @code{jump} command is to back | |
10580 | up---perhaps with more breakpoints set---over a portion of a program | |
10581 | that has already executed, in order to examine its execution in more | |
10582 | detail. | |
10583 | ||
c906108c | 10584 | @c @group |
6d2ebf8b | 10585 | @node Signaling |
c906108c | 10586 | @section Giving your program a signal |
9c16f35a | 10587 | @cindex deliver a signal to a program |
c906108c SS |
10588 | |
10589 | @table @code | |
10590 | @kindex signal | |
10591 | @item signal @var{signal} | |
10592 | Resume execution where your program stopped, but immediately give it the | |
10593 | signal @var{signal}. @var{signal} can be the name or the number of a | |
10594 | signal. For example, on many systems @code{signal 2} and @code{signal | |
10595 | SIGINT} are both ways of sending an interrupt signal. | |
10596 | ||
10597 | Alternatively, if @var{signal} is zero, continue execution without | |
10598 | giving a signal. This is useful when your program stopped on account of | |
10599 | a signal and would ordinary see the signal when resumed with the | |
10600 | @code{continue} command; @samp{signal 0} causes it to resume without a | |
10601 | signal. | |
10602 | ||
10603 | @code{signal} does not repeat when you press @key{RET} a second time | |
10604 | after executing the command. | |
10605 | @end table | |
10606 | @c @end group | |
10607 | ||
10608 | Invoking the @code{signal} command is not the same as invoking the | |
10609 | @code{kill} utility from the shell. Sending a signal with @code{kill} | |
10610 | causes @value{GDBN} to decide what to do with the signal depending on | |
10611 | the signal handling tables (@pxref{Signals}). The @code{signal} command | |
10612 | passes the signal directly to your program. | |
10613 | ||
c906108c | 10614 | |
6d2ebf8b | 10615 | @node Returning |
c906108c SS |
10616 | @section Returning from a function |
10617 | ||
10618 | @table @code | |
10619 | @cindex returning from a function | |
10620 | @kindex return | |
10621 | @item return | |
10622 | @itemx return @var{expression} | |
10623 | You can cancel execution of a function call with the @code{return} | |
10624 | command. If you give an | |
10625 | @var{expression} argument, its value is used as the function's return | |
10626 | value. | |
10627 | @end table | |
10628 | ||
10629 | When you use @code{return}, @value{GDBN} discards the selected stack frame | |
10630 | (and all frames within it). You can think of this as making the | |
10631 | discarded frame return prematurely. If you wish to specify a value to | |
10632 | be returned, give that value as the argument to @code{return}. | |
10633 | ||
10634 | This pops the selected stack frame (@pxref{Selection, ,Selecting a | |
10635 | frame}), and any other frames inside of it, leaving its caller as the | |
10636 | innermost remaining frame. That frame becomes selected. The | |
10637 | specified value is stored in the registers used for returning values | |
10638 | of functions. | |
10639 | ||
10640 | The @code{return} command does not resume execution; it leaves the | |
10641 | program stopped in the state that would exist if the function had just | |
10642 | returned. In contrast, the @code{finish} command (@pxref{Continuing | |
10643 | and Stepping, ,Continuing and stepping}) resumes execution until the | |
10644 | selected stack frame returns naturally. | |
10645 | ||
6d2ebf8b | 10646 | @node Calling |
c906108c SS |
10647 | @section Calling program functions |
10648 | ||
f8568604 | 10649 | @table @code |
c906108c | 10650 | @cindex calling functions |
f8568604 EZ |
10651 | @cindex inferior functions, calling |
10652 | @item print @var{expr} | |
9c16f35a | 10653 | Evaluate the expression @var{expr} and display the resuling value. |
f8568604 EZ |
10654 | @var{expr} may include calls to functions in the program being |
10655 | debugged. | |
10656 | ||
c906108c | 10657 | @kindex call |
c906108c SS |
10658 | @item call @var{expr} |
10659 | Evaluate the expression @var{expr} without displaying @code{void} | |
10660 | returned values. | |
c906108c SS |
10661 | |
10662 | You can use this variant of the @code{print} command if you want to | |
f8568604 EZ |
10663 | execute a function from your program that does not return anything |
10664 | (a.k.a.@: @dfn{a void function}), but without cluttering the output | |
10665 | with @code{void} returned values that @value{GDBN} will otherwise | |
10666 | print. If the result is not void, it is printed and saved in the | |
10667 | value history. | |
10668 | @end table | |
10669 | ||
9c16f35a EZ |
10670 | It is possible for the function you call via the @code{print} or |
10671 | @code{call} command to generate a signal (e.g., if there's a bug in | |
10672 | the function, or if you passed it incorrect arguments). What happens | |
10673 | in that case is controlled by the @code{set unwindonsignal} command. | |
10674 | ||
10675 | @table @code | |
10676 | @item set unwindonsignal | |
10677 | @kindex set unwindonsignal | |
10678 | @cindex unwind stack in called functions | |
10679 | @cindex call dummy stack unwinding | |
10680 | Set unwinding of the stack if a signal is received while in a function | |
10681 | that @value{GDBN} called in the program being debugged. If set to on, | |
10682 | @value{GDBN} unwinds the stack it created for the call and restores | |
10683 | the context to what it was before the call. If set to off (the | |
10684 | default), @value{GDBN} stops in the frame where the signal was | |
10685 | received. | |
10686 | ||
10687 | @item show unwindonsignal | |
10688 | @kindex show unwindonsignal | |
10689 | Show the current setting of stack unwinding in the functions called by | |
10690 | @value{GDBN}. | |
10691 | @end table | |
10692 | ||
f8568604 EZ |
10693 | @cindex weak alias functions |
10694 | Sometimes, a function you wish to call is actually a @dfn{weak alias} | |
10695 | for another function. In such case, @value{GDBN} might not pick up | |
10696 | the type information, including the types of the function arguments, | |
10697 | which causes @value{GDBN} to call the inferior function incorrectly. | |
10698 | As a result, the called function will function erroneously and may | |
10699 | even crash. A solution to that is to use the name of the aliased | |
10700 | function instead. | |
c906108c | 10701 | |
6d2ebf8b | 10702 | @node Patching |
c906108c | 10703 | @section Patching programs |
7a292a7a | 10704 | |
c906108c SS |
10705 | @cindex patching binaries |
10706 | @cindex writing into executables | |
c906108c | 10707 | @cindex writing into corefiles |
c906108c | 10708 | |
7a292a7a SS |
10709 | By default, @value{GDBN} opens the file containing your program's |
10710 | executable code (or the corefile) read-only. This prevents accidental | |
10711 | alterations to machine code; but it also prevents you from intentionally | |
10712 | patching your program's binary. | |
c906108c SS |
10713 | |
10714 | If you'd like to be able to patch the binary, you can specify that | |
10715 | explicitly with the @code{set write} command. For example, you might | |
10716 | want to turn on internal debugging flags, or even to make emergency | |
10717 | repairs. | |
10718 | ||
10719 | @table @code | |
10720 | @kindex set write | |
10721 | @item set write on | |
10722 | @itemx set write off | |
7a292a7a SS |
10723 | If you specify @samp{set write on}, @value{GDBN} opens executable and |
10724 | core files for both reading and writing; if you specify @samp{set write | |
c906108c SS |
10725 | off} (the default), @value{GDBN} opens them read-only. |
10726 | ||
10727 | If you have already loaded a file, you must load it again (using the | |
7a292a7a SS |
10728 | @code{exec-file} or @code{core-file} command) after changing @code{set |
10729 | write}, for your new setting to take effect. | |
c906108c SS |
10730 | |
10731 | @item show write | |
10732 | @kindex show write | |
7a292a7a SS |
10733 | Display whether executable files and core files are opened for writing |
10734 | as well as reading. | |
c906108c SS |
10735 | @end table |
10736 | ||
6d2ebf8b | 10737 | @node GDB Files |
c906108c SS |
10738 | @chapter @value{GDBN} Files |
10739 | ||
7a292a7a SS |
10740 | @value{GDBN} needs to know the file name of the program to be debugged, |
10741 | both in order to read its symbol table and in order to start your | |
10742 | program. To debug a core dump of a previous run, you must also tell | |
10743 | @value{GDBN} the name of the core dump file. | |
c906108c SS |
10744 | |
10745 | @menu | |
10746 | * Files:: Commands to specify files | |
5b5d99cf | 10747 | * Separate Debug Files:: Debugging information in separate files |
c906108c SS |
10748 | * Symbol Errors:: Errors reading symbol files |
10749 | @end menu | |
10750 | ||
6d2ebf8b | 10751 | @node Files |
c906108c | 10752 | @section Commands to specify files |
c906108c | 10753 | |
7a292a7a | 10754 | @cindex symbol table |
c906108c | 10755 | @cindex core dump file |
7a292a7a SS |
10756 | |
10757 | You may want to specify executable and core dump file names. The usual | |
10758 | way to do this is at start-up time, using the arguments to | |
10759 | @value{GDBN}'s start-up commands (@pxref{Invocation, , Getting In and | |
10760 | Out of @value{GDBN}}). | |
c906108c SS |
10761 | |
10762 | Occasionally it is necessary to change to a different file during a | |
397ca115 EZ |
10763 | @value{GDBN} session. Or you may run @value{GDBN} and forget to |
10764 | specify a file you want to use. Or you are debugging a remote target | |
10765 | via @code{gdbserver} (@pxref{Server, file}). In these situations the | |
10766 | @value{GDBN} commands to specify new files are useful. | |
c906108c SS |
10767 | |
10768 | @table @code | |
10769 | @cindex executable file | |
10770 | @kindex file | |
10771 | @item file @var{filename} | |
10772 | Use @var{filename} as the program to be debugged. It is read for its | |
10773 | symbols and for the contents of pure memory. It is also the program | |
10774 | executed when you use the @code{run} command. If you do not specify a | |
5d161b24 DB |
10775 | directory and the file is not found in the @value{GDBN} working directory, |
10776 | @value{GDBN} uses the environment variable @code{PATH} as a list of | |
10777 | directories to search, just as the shell does when looking for a program | |
10778 | to run. You can change the value of this variable, for both @value{GDBN} | |
c906108c SS |
10779 | and your program, using the @code{path} command. |
10780 | ||
fc8be69e EZ |
10781 | @cindex unlinked object files |
10782 | @cindex patching object files | |
10783 | You can load unlinked object @file{.o} files into @value{GDBN} using | |
10784 | the @code{file} command. You will not be able to ``run'' an object | |
10785 | file, but you can disassemble functions and inspect variables. Also, | |
10786 | if the underlying BFD functionality supports it, you could use | |
10787 | @kbd{gdb -write} to patch object files using this technique. Note | |
10788 | that @value{GDBN} can neither interpret nor modify relocations in this | |
10789 | case, so branches and some initialized variables will appear to go to | |
10790 | the wrong place. But this feature is still handy from time to time. | |
10791 | ||
c906108c SS |
10792 | @item file |
10793 | @code{file} with no argument makes @value{GDBN} discard any information it | |
10794 | has on both executable file and the symbol table. | |
10795 | ||
10796 | @kindex exec-file | |
10797 | @item exec-file @r{[} @var{filename} @r{]} | |
10798 | Specify that the program to be run (but not the symbol table) is found | |
10799 | in @var{filename}. @value{GDBN} searches the environment variable @code{PATH} | |
10800 | if necessary to locate your program. Omitting @var{filename} means to | |
10801 | discard information on the executable file. | |
10802 | ||
10803 | @kindex symbol-file | |
10804 | @item symbol-file @r{[} @var{filename} @r{]} | |
10805 | Read symbol table information from file @var{filename}. @code{PATH} is | |
10806 | searched when necessary. Use the @code{file} command to get both symbol | |
10807 | table and program to run from the same file. | |
10808 | ||
10809 | @code{symbol-file} with no argument clears out @value{GDBN} information on your | |
10810 | program's symbol table. | |
10811 | ||
5d161b24 | 10812 | The @code{symbol-file} command causes @value{GDBN} to forget the contents |
c906108c SS |
10813 | of its convenience variables, the value history, and all breakpoints and |
10814 | auto-display expressions. This is because they may contain pointers to | |
10815 | the internal data recording symbols and data types, which are part of | |
10816 | the old symbol table data being discarded inside @value{GDBN}. | |
10817 | ||
10818 | @code{symbol-file} does not repeat if you press @key{RET} again after | |
10819 | executing it once. | |
10820 | ||
10821 | When @value{GDBN} is configured for a particular environment, it | |
10822 | understands debugging information in whatever format is the standard | |
10823 | generated for that environment; you may use either a @sc{gnu} compiler, or | |
10824 | other compilers that adhere to the local conventions. | |
c906108c SS |
10825 | Best results are usually obtained from @sc{gnu} compilers; for example, |
10826 | using @code{@value{GCC}} you can generate debugging information for | |
10827 | optimized code. | |
c906108c SS |
10828 | |
10829 | For most kinds of object files, with the exception of old SVR3 systems | |
10830 | using COFF, the @code{symbol-file} command does not normally read the | |
10831 | symbol table in full right away. Instead, it scans the symbol table | |
10832 | quickly to find which source files and which symbols are present. The | |
10833 | details are read later, one source file at a time, as they are needed. | |
10834 | ||
10835 | The purpose of this two-stage reading strategy is to make @value{GDBN} | |
10836 | start up faster. For the most part, it is invisible except for | |
10837 | occasional pauses while the symbol table details for a particular source | |
10838 | file are being read. (The @code{set verbose} command can turn these | |
10839 | pauses into messages if desired. @xref{Messages/Warnings, ,Optional | |
10840 | warnings and messages}.) | |
10841 | ||
c906108c SS |
10842 | We have not implemented the two-stage strategy for COFF yet. When the |
10843 | symbol table is stored in COFF format, @code{symbol-file} reads the | |
10844 | symbol table data in full right away. Note that ``stabs-in-COFF'' | |
10845 | still does the two-stage strategy, since the debug info is actually | |
10846 | in stabs format. | |
10847 | ||
10848 | @kindex readnow | |
10849 | @cindex reading symbols immediately | |
10850 | @cindex symbols, reading immediately | |
a94ab193 EZ |
10851 | @item symbol-file @var{filename} @r{[} -readnow @r{]} |
10852 | @itemx file @var{filename} @r{[} -readnow @r{]} | |
c906108c SS |
10853 | You can override the @value{GDBN} two-stage strategy for reading symbol |
10854 | tables by using the @samp{-readnow} option with any of the commands that | |
10855 | load symbol table information, if you want to be sure @value{GDBN} has the | |
5d161b24 | 10856 | entire symbol table available. |
c906108c | 10857 | |
c906108c SS |
10858 | @c FIXME: for now no mention of directories, since this seems to be in |
10859 | @c flux. 13mar1992 status is that in theory GDB would look either in | |
10860 | @c current dir or in same dir as myprog; but issues like competing | |
10861 | @c GDB's, or clutter in system dirs, mean that in practice right now | |
10862 | @c only current dir is used. FFish says maybe a special GDB hierarchy | |
10863 | @c (eg rooted in val of env var GDBSYMS) could exist for mappable symbol | |
10864 | @c files. | |
10865 | ||
c906108c | 10866 | @kindex core-file |
09d4efe1 | 10867 | @item core-file @r{[}@var{filename}@r{]} |
4644b6e3 | 10868 | @itemx core |
c906108c SS |
10869 | Specify the whereabouts of a core dump file to be used as the ``contents |
10870 | of memory''. Traditionally, core files contain only some parts of the | |
10871 | address space of the process that generated them; @value{GDBN} can access the | |
10872 | executable file itself for other parts. | |
10873 | ||
10874 | @code{core-file} with no argument specifies that no core file is | |
10875 | to be used. | |
10876 | ||
10877 | Note that the core file is ignored when your program is actually running | |
7a292a7a SS |
10878 | under @value{GDBN}. So, if you have been running your program and you |
10879 | wish to debug a core file instead, you must kill the subprocess in which | |
10880 | the program is running. To do this, use the @code{kill} command | |
c906108c | 10881 | (@pxref{Kill Process, ,Killing the child process}). |
c906108c | 10882 | |
c906108c SS |
10883 | @kindex add-symbol-file |
10884 | @cindex dynamic linking | |
10885 | @item add-symbol-file @var{filename} @var{address} | |
a94ab193 | 10886 | @itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]} |
17d9d558 | 10887 | @itemx add-symbol-file @var{filename} @r{-s}@var{section} @var{address} @dots{} |
96a2c332 SS |
10888 | The @code{add-symbol-file} command reads additional symbol table |
10889 | information from the file @var{filename}. You would use this command | |
10890 | when @var{filename} has been dynamically loaded (by some other means) | |
10891 | into the program that is running. @var{address} should be the memory | |
10892 | address at which the file has been loaded; @value{GDBN} cannot figure | |
d167840f EZ |
10893 | this out for itself. You can additionally specify an arbitrary number |
10894 | of @samp{@r{-s}@var{section} @var{address}} pairs, to give an explicit | |
10895 | section name and base address for that section. You can specify any | |
10896 | @var{address} as an expression. | |
c906108c SS |
10897 | |
10898 | The symbol table of the file @var{filename} is added to the symbol table | |
10899 | originally read with the @code{symbol-file} command. You can use the | |
96a2c332 SS |
10900 | @code{add-symbol-file} command any number of times; the new symbol data |
10901 | thus read keeps adding to the old. To discard all old symbol data | |
10902 | instead, use the @code{symbol-file} command without any arguments. | |
c906108c | 10903 | |
17d9d558 JB |
10904 | @cindex relocatable object files, reading symbols from |
10905 | @cindex object files, relocatable, reading symbols from | |
10906 | @cindex reading symbols from relocatable object files | |
10907 | @cindex symbols, reading from relocatable object files | |
10908 | @cindex @file{.o} files, reading symbols from | |
10909 | Although @var{filename} is typically a shared library file, an | |
10910 | executable file, or some other object file which has been fully | |
10911 | relocated for loading into a process, you can also load symbolic | |
10912 | information from relocatable @file{.o} files, as long as: | |
10913 | ||
10914 | @itemize @bullet | |
10915 | @item | |
10916 | the file's symbolic information refers only to linker symbols defined in | |
10917 | that file, not to symbols defined by other object files, | |
10918 | @item | |
10919 | every section the file's symbolic information refers to has actually | |
10920 | been loaded into the inferior, as it appears in the file, and | |
10921 | @item | |
10922 | you can determine the address at which every section was loaded, and | |
10923 | provide these to the @code{add-symbol-file} command. | |
10924 | @end itemize | |
10925 | ||
10926 | @noindent | |
10927 | Some embedded operating systems, like Sun Chorus and VxWorks, can load | |
10928 | relocatable files into an already running program; such systems | |
10929 | typically make the requirements above easy to meet. However, it's | |
10930 | important to recognize that many native systems use complex link | |
49efadf5 | 10931 | procedures (@code{.linkonce} section factoring and C@t{++} constructor table |
17d9d558 JB |
10932 | assembly, for example) that make the requirements difficult to meet. In |
10933 | general, one cannot assume that using @code{add-symbol-file} to read a | |
10934 | relocatable object file's symbolic information will have the same effect | |
10935 | as linking the relocatable object file into the program in the normal | |
10936 | way. | |
10937 | ||
c906108c SS |
10938 | @code{add-symbol-file} does not repeat if you press @key{RET} after using it. |
10939 | ||
c45da7e6 EZ |
10940 | @kindex add-symbol-file-from-memory |
10941 | @cindex @code{syscall DSO} | |
10942 | @cindex load symbols from memory | |
10943 | @item add-symbol-file-from-memory @var{address} | |
10944 | Load symbols from the given @var{address} in a dynamically loaded | |
10945 | object file whose image is mapped directly into the inferior's memory. | |
10946 | For example, the Linux kernel maps a @code{syscall DSO} into each | |
10947 | process's address space; this DSO provides kernel-specific code for | |
10948 | some system calls. The argument can be any expression whose | |
10949 | evaluation yields the address of the file's shared object file header. | |
10950 | For this command to work, you must have used @code{symbol-file} or | |
10951 | @code{exec-file} commands in advance. | |
10952 | ||
09d4efe1 EZ |
10953 | @kindex add-shared-symbol-files |
10954 | @kindex assf | |
10955 | @item add-shared-symbol-files @var{library-file} | |
10956 | @itemx assf @var{library-file} | |
10957 | The @code{add-shared-symbol-files} command can currently be used only | |
10958 | in the Cygwin build of @value{GDBN} on MS-Windows OS, where it is an | |
10959 | alias for the @code{dll-symbols} command (@pxref{Cygwin Native}). | |
10960 | @value{GDBN} automatically looks for shared libraries, however if | |
10961 | @value{GDBN} does not find yours, you can invoke | |
10962 | @code{add-shared-symbol-files}. It takes one argument: the shared | |
10963 | library's file name. @code{assf} is a shorthand alias for | |
10964 | @code{add-shared-symbol-files}. | |
c906108c | 10965 | |
c906108c | 10966 | @kindex section |
09d4efe1 EZ |
10967 | @item section @var{section} @var{addr} |
10968 | The @code{section} command changes the base address of the named | |
10969 | @var{section} of the exec file to @var{addr}. This can be used if the | |
10970 | exec file does not contain section addresses, (such as in the | |
10971 | @code{a.out} format), or when the addresses specified in the file | |
10972 | itself are wrong. Each section must be changed separately. The | |
10973 | @code{info files} command, described below, lists all the sections and | |
10974 | their addresses. | |
c906108c SS |
10975 | |
10976 | @kindex info files | |
10977 | @kindex info target | |
10978 | @item info files | |
10979 | @itemx info target | |
7a292a7a SS |
10980 | @code{info files} and @code{info target} are synonymous; both print the |
10981 | current target (@pxref{Targets, ,Specifying a Debugging Target}), | |
10982 | including the names of the executable and core dump files currently in | |
10983 | use by @value{GDBN}, and the files from which symbols were loaded. The | |
10984 | command @code{help target} lists all possible targets rather than | |
10985 | current ones. | |
10986 | ||
fe95c787 MS |
10987 | @kindex maint info sections |
10988 | @item maint info sections | |
10989 | Another command that can give you extra information about program sections | |
10990 | is @code{maint info sections}. In addition to the section information | |
10991 | displayed by @code{info files}, this command displays the flags and file | |
10992 | offset of each section in the executable and core dump files. In addition, | |
10993 | @code{maint info sections} provides the following command options (which | |
10994 | may be arbitrarily combined): | |
10995 | ||
10996 | @table @code | |
10997 | @item ALLOBJ | |
10998 | Display sections for all loaded object files, including shared libraries. | |
10999 | @item @var{sections} | |
6600abed | 11000 | Display info only for named @var{sections}. |
fe95c787 MS |
11001 | @item @var{section-flags} |
11002 | Display info only for sections for which @var{section-flags} are true. | |
11003 | The section flags that @value{GDBN} currently knows about are: | |
11004 | @table @code | |
11005 | @item ALLOC | |
11006 | Section will have space allocated in the process when loaded. | |
11007 | Set for all sections except those containing debug information. | |
11008 | @item LOAD | |
11009 | Section will be loaded from the file into the child process memory. | |
11010 | Set for pre-initialized code and data, clear for @code{.bss} sections. | |
11011 | @item RELOC | |
11012 | Section needs to be relocated before loading. | |
11013 | @item READONLY | |
11014 | Section cannot be modified by the child process. | |
11015 | @item CODE | |
11016 | Section contains executable code only. | |
6600abed | 11017 | @item DATA |
fe95c787 MS |
11018 | Section contains data only (no executable code). |
11019 | @item ROM | |
11020 | Section will reside in ROM. | |
11021 | @item CONSTRUCTOR | |
11022 | Section contains data for constructor/destructor lists. | |
11023 | @item HAS_CONTENTS | |
11024 | Section is not empty. | |
11025 | @item NEVER_LOAD | |
11026 | An instruction to the linker to not output the section. | |
11027 | @item COFF_SHARED_LIBRARY | |
11028 | A notification to the linker that the section contains | |
11029 | COFF shared library information. | |
11030 | @item IS_COMMON | |
11031 | Section contains common symbols. | |
11032 | @end table | |
11033 | @end table | |
6763aef9 | 11034 | @kindex set trust-readonly-sections |
9c16f35a | 11035 | @cindex read-only sections |
6763aef9 MS |
11036 | @item set trust-readonly-sections on |
11037 | Tell @value{GDBN} that readonly sections in your object file | |
6ca652b0 | 11038 | really are read-only (i.e.@: that their contents will not change). |
6763aef9 MS |
11039 | In that case, @value{GDBN} can fetch values from these sections |
11040 | out of the object file, rather than from the target program. | |
11041 | For some targets (notably embedded ones), this can be a significant | |
11042 | enhancement to debugging performance. | |
11043 | ||
11044 | The default is off. | |
11045 | ||
11046 | @item set trust-readonly-sections off | |
15110bc3 | 11047 | Tell @value{GDBN} not to trust readonly sections. This means that |
6763aef9 MS |
11048 | the contents of the section might change while the program is running, |
11049 | and must therefore be fetched from the target when needed. | |
9c16f35a EZ |
11050 | |
11051 | @item show trust-readonly-sections | |
11052 | Show the current setting of trusting readonly sections. | |
c906108c SS |
11053 | @end table |
11054 | ||
11055 | All file-specifying commands allow both absolute and relative file names | |
11056 | as arguments. @value{GDBN} always converts the file name to an absolute file | |
11057 | name and remembers it that way. | |
11058 | ||
c906108c | 11059 | @cindex shared libraries |
9c16f35a EZ |
11060 | @value{GDBN} supports GNU/Linux, MS-Windows, HP-UX, SunOS, SVr4, Irix, |
11061 | and IBM RS/6000 AIX shared libraries. | |
53a5351d | 11062 | |
c906108c SS |
11063 | @value{GDBN} automatically loads symbol definitions from shared libraries |
11064 | when you use the @code{run} command, or when you examine a core file. | |
11065 | (Before you issue the @code{run} command, @value{GDBN} does not understand | |
11066 | references to a function in a shared library, however---unless you are | |
11067 | debugging a core file). | |
53a5351d JM |
11068 | |
11069 | On HP-UX, if the program loads a library explicitly, @value{GDBN} | |
11070 | automatically loads the symbols at the time of the @code{shl_load} call. | |
11071 | ||
c906108c SS |
11072 | @c FIXME: some @value{GDBN} release may permit some refs to undef |
11073 | @c FIXME...symbols---eg in a break cmd---assuming they are from a shared | |
11074 | @c FIXME...lib; check this from time to time when updating manual | |
11075 | ||
b7209cb4 FF |
11076 | There are times, however, when you may wish to not automatically load |
11077 | symbol definitions from shared libraries, such as when they are | |
11078 | particularly large or there are many of them. | |
11079 | ||
11080 | To control the automatic loading of shared library symbols, use the | |
11081 | commands: | |
11082 | ||
11083 | @table @code | |
11084 | @kindex set auto-solib-add | |
11085 | @item set auto-solib-add @var{mode} | |
11086 | If @var{mode} is @code{on}, symbols from all shared object libraries | |
11087 | will be loaded automatically when the inferior begins execution, you | |
11088 | attach to an independently started inferior, or when the dynamic linker | |
11089 | informs @value{GDBN} that a new library has been loaded. If @var{mode} | |
11090 | is @code{off}, symbols must be loaded manually, using the | |
11091 | @code{sharedlibrary} command. The default value is @code{on}. | |
11092 | ||
dcaf7c2c EZ |
11093 | @cindex memory used for symbol tables |
11094 | If your program uses lots of shared libraries with debug info that | |
11095 | takes large amounts of memory, you can decrease the @value{GDBN} | |
11096 | memory footprint by preventing it from automatically loading the | |
11097 | symbols from shared libraries. To that end, type @kbd{set | |
11098 | auto-solib-add off} before running the inferior, then load each | |
11099 | library whose debug symbols you do need with @kbd{sharedlibrary | |
11100 | @var{regexp}}, where @var{regexp} is a regular expresion that matches | |
11101 | the libraries whose symbols you want to be loaded. | |
11102 | ||
b7209cb4 FF |
11103 | @kindex show auto-solib-add |
11104 | @item show auto-solib-add | |
11105 | Display the current autoloading mode. | |
11106 | @end table | |
11107 | ||
c45da7e6 | 11108 | @cindex load shared library |
b7209cb4 FF |
11109 | To explicitly load shared library symbols, use the @code{sharedlibrary} |
11110 | command: | |
11111 | ||
c906108c SS |
11112 | @table @code |
11113 | @kindex info sharedlibrary | |
11114 | @kindex info share | |
11115 | @item info share | |
11116 | @itemx info sharedlibrary | |
11117 | Print the names of the shared libraries which are currently loaded. | |
11118 | ||
11119 | @kindex sharedlibrary | |
11120 | @kindex share | |
11121 | @item sharedlibrary @var{regex} | |
11122 | @itemx share @var{regex} | |
c906108c SS |
11123 | Load shared object library symbols for files matching a |
11124 | Unix regular expression. | |
11125 | As with files loaded automatically, it only loads shared libraries | |
11126 | required by your program for a core file or after typing @code{run}. If | |
11127 | @var{regex} is omitted all shared libraries required by your program are | |
11128 | loaded. | |
c45da7e6 EZ |
11129 | |
11130 | @item nosharedlibrary | |
11131 | @kindex nosharedlibrary | |
11132 | @cindex unload symbols from shared libraries | |
11133 | Unload all shared object library symbols. This discards all symbols | |
11134 | that have been loaded from all shared libraries. Symbols from shared | |
11135 | libraries that were loaded by explicit user requests are not | |
11136 | discarded. | |
c906108c SS |
11137 | @end table |
11138 | ||
721c2651 EZ |
11139 | Sometimes you may wish that @value{GDBN} stops and gives you control |
11140 | when any of shared library events happen. Use the @code{set | |
11141 | stop-on-solib-events} command for this: | |
11142 | ||
11143 | @table @code | |
11144 | @item set stop-on-solib-events | |
11145 | @kindex set stop-on-solib-events | |
11146 | This command controls whether @value{GDBN} should give you control | |
11147 | when the dynamic linker notifies it about some shared library event. | |
11148 | The most common event of interest is loading or unloading of a new | |
11149 | shared library. | |
11150 | ||
11151 | @item show stop-on-solib-events | |
11152 | @kindex show stop-on-solib-events | |
11153 | Show whether @value{GDBN} stops and gives you control when shared | |
11154 | library events happen. | |
11155 | @end table | |
11156 | ||
f5ebfba0 DJ |
11157 | Shared libraries are also supported in many cross or remote debugging |
11158 | configurations. A copy of the target's libraries need to be present on the | |
11159 | host system; they need to be the same as the target libraries, although the | |
11160 | copies on the target can be stripped as long as the copies on the host are | |
11161 | not. | |
11162 | ||
59b7b46f EZ |
11163 | @cindex where to look for shared libraries |
11164 | For remote debugging, you need to tell @value{GDBN} where the target | |
11165 | libraries are, so that it can load the correct copies---otherwise, it | |
11166 | may try to load the host's libraries. @value{GDBN} has two variables | |
11167 | to specify the search directories for target libraries. | |
f5ebfba0 DJ |
11168 | |
11169 | @table @code | |
59b7b46f | 11170 | @cindex prefix for shared library file names |
f5ebfba0 DJ |
11171 | @kindex set solib-absolute-prefix |
11172 | @item set solib-absolute-prefix @var{path} | |
11173 | If this variable is set, @var{path} will be used as a prefix for any | |
11174 | absolute shared library paths; many runtime loaders store the absolute | |
11175 | paths to the shared library in the target program's memory. If you use | |
11176 | @samp{solib-absolute-prefix} to find shared libraries, they need to be laid | |
11177 | out in the same way that they are on the target, with e.g.@: a | |
11178 | @file{/usr/lib} hierarchy under @var{path}. | |
11179 | ||
59b7b46f EZ |
11180 | @cindex default value of @samp{solib-absolute-prefix} |
11181 | @cindex @samp{--with-sysroot} | |
f5ebfba0 DJ |
11182 | You can set the default value of @samp{solib-absolute-prefix} by using the |
11183 | configure-time @samp{--with-sysroot} option. | |
11184 | ||
11185 | @kindex show solib-absolute-prefix | |
11186 | @item show solib-absolute-prefix | |
11187 | Display the current shared library prefix. | |
11188 | ||
11189 | @kindex set solib-search-path | |
11190 | @item set solib-search-path @var{path} | |
11191 | If this variable is set, @var{path} is a colon-separated list of directories | |
11192 | to search for shared libraries. @samp{solib-search-path} is used after | |
11193 | @samp{solib-absolute-prefix} fails to locate the library, or if the path to | |
11194 | the library is relative instead of absolute. If you want to use | |
11195 | @samp{solib-search-path} instead of @samp{solib-absolute-prefix}, be sure to | |
11196 | set @samp{solib-absolute-prefix} to a nonexistant directory to prevent | |
11197 | @value{GDBN} from finding your host's libraries. | |
11198 | ||
11199 | @kindex show solib-search-path | |
11200 | @item show solib-search-path | |
11201 | Display the current shared library search path. | |
11202 | @end table | |
11203 | ||
5b5d99cf JB |
11204 | |
11205 | @node Separate Debug Files | |
11206 | @section Debugging Information in Separate Files | |
11207 | @cindex separate debugging information files | |
11208 | @cindex debugging information in separate files | |
11209 | @cindex @file{.debug} subdirectories | |
11210 | @cindex debugging information directory, global | |
11211 | @cindex global debugging information directory | |
11212 | ||
11213 | @value{GDBN} allows you to put a program's debugging information in a | |
11214 | file separate from the executable itself, in a way that allows | |
11215 | @value{GDBN} to find and load the debugging information automatically. | |
11216 | Since debugging information can be very large --- sometimes larger | |
11217 | than the executable code itself --- some systems distribute debugging | |
11218 | information for their executables in separate files, which users can | |
11219 | install only when they need to debug a problem. | |
11220 | ||
11221 | If an executable's debugging information has been extracted to a | |
11222 | separate file, the executable should contain a @dfn{debug link} giving | |
11223 | the name of the debugging information file (with no directory | |
11224 | components), and a checksum of its contents. (The exact form of a | |
11225 | debug link is described below.) If the full name of the directory | |
11226 | containing the executable is @var{execdir}, and the executable has a | |
11227 | debug link that specifies the name @var{debugfile}, then @value{GDBN} | |
11228 | will automatically search for the debugging information file in three | |
11229 | places: | |
11230 | ||
11231 | @itemize @bullet | |
11232 | @item | |
11233 | the directory containing the executable file (that is, it will look | |
11234 | for a file named @file{@var{execdir}/@var{debugfile}}, | |
11235 | @item | |
11236 | a subdirectory of that directory named @file{.debug} (that is, the | |
11237 | file @file{@var{execdir}/.debug/@var{debugfile}}, and | |
11238 | @item | |
11239 | a subdirectory of the global debug file directory that includes the | |
11240 | executable's full path, and the name from the link (that is, the file | |
11241 | @file{@var{globaldebugdir}/@var{execdir}/@var{debugfile}}, where | |
11242 | @var{globaldebugdir} is the global debug file directory, and | |
11243 | @var{execdir} has been turned into a relative path). | |
11244 | @end itemize | |
11245 | @noindent | |
11246 | @value{GDBN} checks under each of these names for a debugging | |
11247 | information file whose checksum matches that given in the link, and | |
11248 | reads the debugging information from the first one it finds. | |
11249 | ||
11250 | So, for example, if you ask @value{GDBN} to debug @file{/usr/bin/ls}, | |
11251 | which has a link containing the name @file{ls.debug}, and the global | |
11252 | debug directory is @file{/usr/lib/debug}, then @value{GDBN} will look | |
11253 | for debug information in @file{/usr/bin/ls.debug}, | |
11254 | @file{/usr/bin/.debug/ls.debug}, and | |
11255 | @file{/usr/lib/debug/usr/bin/ls.debug}. | |
11256 | ||
11257 | You can set the global debugging info directory's name, and view the | |
11258 | name @value{GDBN} is currently using. | |
11259 | ||
11260 | @table @code | |
11261 | ||
11262 | @kindex set debug-file-directory | |
11263 | @item set debug-file-directory @var{directory} | |
11264 | Set the directory which @value{GDBN} searches for separate debugging | |
11265 | information files to @var{directory}. | |
11266 | ||
11267 | @kindex show debug-file-directory | |
11268 | @item show debug-file-directory | |
11269 | Show the directory @value{GDBN} searches for separate debugging | |
11270 | information files. | |
11271 | ||
11272 | @end table | |
11273 | ||
11274 | @cindex @code{.gnu_debuglink} sections | |
11275 | @cindex debug links | |
11276 | A debug link is a special section of the executable file named | |
11277 | @code{.gnu_debuglink}. The section must contain: | |
11278 | ||
11279 | @itemize | |
11280 | @item | |
11281 | A filename, with any leading directory components removed, followed by | |
11282 | a zero byte, | |
11283 | @item | |
11284 | zero to three bytes of padding, as needed to reach the next four-byte | |
11285 | boundary within the section, and | |
11286 | @item | |
11287 | a four-byte CRC checksum, stored in the same endianness used for the | |
11288 | executable file itself. The checksum is computed on the debugging | |
11289 | information file's full contents by the function given below, passing | |
11290 | zero as the @var{crc} argument. | |
11291 | @end itemize | |
11292 | ||
11293 | Any executable file format can carry a debug link, as long as it can | |
11294 | contain a section named @code{.gnu_debuglink} with the contents | |
11295 | described above. | |
11296 | ||
11297 | The debugging information file itself should be an ordinary | |
11298 | executable, containing a full set of linker symbols, sections, and | |
11299 | debugging information. The sections of the debugging information file | |
11300 | should have the same names, addresses and sizes as the original file, | |
11301 | but they need not contain any data --- much like a @code{.bss} section | |
11302 | in an ordinary executable. | |
11303 | ||
11304 | As of December 2002, there is no standard GNU utility to produce | |
11305 | separated executable / debugging information file pairs. Ulrich | |
11306 | Drepper's @file{elfutils} package, starting with version 0.53, | |
11307 | contains a version of the @code{strip} command such that the command | |
11308 | @kbd{strip foo -f foo.debug} removes the debugging information from | |
11309 | the executable file @file{foo}, places it in the file | |
11310 | @file{foo.debug}, and leaves behind a debug link in @file{foo}. | |
11311 | ||
11312 | Since there are many different ways to compute CRC's (different | |
11313 | polynomials, reversals, byte ordering, etc.), the simplest way to | |
11314 | describe the CRC used in @code{.gnu_debuglink} sections is to give the | |
11315 | complete code for a function that computes it: | |
11316 | ||
4644b6e3 | 11317 | @kindex gnu_debuglink_crc32 |
5b5d99cf JB |
11318 | @smallexample |
11319 | unsigned long | |
11320 | gnu_debuglink_crc32 (unsigned long crc, | |
11321 | unsigned char *buf, size_t len) | |
11322 | @{ | |
11323 | static const unsigned long crc32_table[256] = | |
11324 | @{ | |
11325 | 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, | |
11326 | 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, | |
11327 | 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, | |
11328 | 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, | |
11329 | 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, | |
11330 | 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, | |
11331 | 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, | |
11332 | 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, | |
11333 | 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, | |
11334 | 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, | |
11335 | 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, | |
11336 | 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, | |
11337 | 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, | |
11338 | 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, | |
11339 | 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, | |
11340 | 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, | |
11341 | 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, | |
11342 | 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, | |
11343 | 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, | |
11344 | 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, | |
11345 | 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, | |
11346 | 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, | |
11347 | 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, | |
11348 | 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, | |
11349 | 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, | |
11350 | 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, | |
11351 | 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, | |
11352 | 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, | |
11353 | 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, | |
11354 | 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, | |
11355 | 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, | |
11356 | 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, | |
11357 | 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, | |
11358 | 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, | |
11359 | 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, | |
11360 | 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, | |
11361 | 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, | |
11362 | 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, | |
11363 | 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, | |
11364 | 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, | |
11365 | 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, | |
11366 | 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, | |
11367 | 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, | |
11368 | 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, | |
11369 | 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, | |
11370 | 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, | |
11371 | 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, | |
11372 | 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, | |
11373 | 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, | |
11374 | 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, | |
11375 | 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, | |
11376 | 0x2d02ef8d | |
11377 | @}; | |
11378 | unsigned char *end; | |
11379 | ||
11380 | crc = ~crc & 0xffffffff; | |
11381 | for (end = buf + len; buf < end; ++buf) | |
11382 | crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); | |
e7a3abfc | 11383 | return ~crc & 0xffffffff; |
5b5d99cf JB |
11384 | @} |
11385 | @end smallexample | |
11386 | ||
11387 | ||
6d2ebf8b | 11388 | @node Symbol Errors |
c906108c SS |
11389 | @section Errors reading symbol files |
11390 | ||
11391 | While reading a symbol file, @value{GDBN} occasionally encounters problems, | |
11392 | such as symbol types it does not recognize, or known bugs in compiler | |
11393 | output. By default, @value{GDBN} does not notify you of such problems, since | |
11394 | they are relatively common and primarily of interest to people | |
11395 | debugging compilers. If you are interested in seeing information | |
11396 | about ill-constructed symbol tables, you can either ask @value{GDBN} to print | |
11397 | only one message about each such type of problem, no matter how many | |
11398 | times the problem occurs; or you can ask @value{GDBN} to print more messages, | |
11399 | to see how many times the problems occur, with the @code{set | |
11400 | complaints} command (@pxref{Messages/Warnings, ,Optional warnings and | |
11401 | messages}). | |
11402 | ||
11403 | The messages currently printed, and their meanings, include: | |
11404 | ||
11405 | @table @code | |
11406 | @item inner block not inside outer block in @var{symbol} | |
11407 | ||
11408 | The symbol information shows where symbol scopes begin and end | |
11409 | (such as at the start of a function or a block of statements). This | |
11410 | error indicates that an inner scope block is not fully contained | |
11411 | in its outer scope blocks. | |
11412 | ||
11413 | @value{GDBN} circumvents the problem by treating the inner block as if it had | |
11414 | the same scope as the outer block. In the error message, @var{symbol} | |
11415 | may be shown as ``@code{(don't know)}'' if the outer block is not a | |
11416 | function. | |
11417 | ||
11418 | @item block at @var{address} out of order | |
11419 | ||
11420 | The symbol information for symbol scope blocks should occur in | |
11421 | order of increasing addresses. This error indicates that it does not | |
11422 | do so. | |
11423 | ||
11424 | @value{GDBN} does not circumvent this problem, and has trouble | |
11425 | locating symbols in the source file whose symbols it is reading. (You | |
11426 | can often determine what source file is affected by specifying | |
11427 | @code{set verbose on}. @xref{Messages/Warnings, ,Optional warnings and | |
11428 | messages}.) | |
11429 | ||
11430 | @item bad block start address patched | |
11431 | ||
11432 | The symbol information for a symbol scope block has a start address | |
11433 | smaller than the address of the preceding source line. This is known | |
11434 | to occur in the SunOS 4.1.1 (and earlier) C compiler. | |
11435 | ||
11436 | @value{GDBN} circumvents the problem by treating the symbol scope block as | |
11437 | starting on the previous source line. | |
11438 | ||
11439 | @item bad string table offset in symbol @var{n} | |
11440 | ||
11441 | @cindex foo | |
11442 | Symbol number @var{n} contains a pointer into the string table which is | |
11443 | larger than the size of the string table. | |
11444 | ||
11445 | @value{GDBN} circumvents the problem by considering the symbol to have the | |
11446 | name @code{foo}, which may cause other problems if many symbols end up | |
11447 | with this name. | |
11448 | ||
11449 | @item unknown symbol type @code{0x@var{nn}} | |
11450 | ||
7a292a7a SS |
11451 | The symbol information contains new data types that @value{GDBN} does |
11452 | not yet know how to read. @code{0x@var{nn}} is the symbol type of the | |
d4f3574e | 11453 | uncomprehended information, in hexadecimal. |
c906108c | 11454 | |
7a292a7a SS |
11455 | @value{GDBN} circumvents the error by ignoring this symbol information. |
11456 | This usually allows you to debug your program, though certain symbols | |
c906108c | 11457 | are not accessible. If you encounter such a problem and feel like |
7a292a7a SS |
11458 | debugging it, you can debug @code{@value{GDBP}} with itself, breakpoint |
11459 | on @code{complain}, then go up to the function @code{read_dbx_symtab} | |
11460 | and examine @code{*bufp} to see the symbol. | |
c906108c SS |
11461 | |
11462 | @item stub type has NULL name | |
c906108c | 11463 | |
7a292a7a | 11464 | @value{GDBN} could not find the full definition for a struct or class. |
c906108c | 11465 | |
7a292a7a | 11466 | @item const/volatile indicator missing (ok if using g++ v1.x), got@dots{} |
b37052ae | 11467 | The symbol information for a C@t{++} member function is missing some |
7a292a7a SS |
11468 | information that recent versions of the compiler should have output for |
11469 | it. | |
c906108c SS |
11470 | |
11471 | @item info mismatch between compiler and debugger | |
11472 | ||
11473 | @value{GDBN} could not parse a type specification output by the compiler. | |
7a292a7a | 11474 | |
c906108c SS |
11475 | @end table |
11476 | ||
6d2ebf8b | 11477 | @node Targets |
c906108c | 11478 | @chapter Specifying a Debugging Target |
7a292a7a | 11479 | |
c906108c | 11480 | @cindex debugging target |
c906108c | 11481 | A @dfn{target} is the execution environment occupied by your program. |
53a5351d JM |
11482 | |
11483 | Often, @value{GDBN} runs in the same host environment as your program; | |
11484 | in that case, the debugging target is specified as a side effect when | |
11485 | you use the @code{file} or @code{core} commands. When you need more | |
c906108c SS |
11486 | flexibility---for example, running @value{GDBN} on a physically separate |
11487 | host, or controlling a standalone system over a serial port or a | |
53a5351d JM |
11488 | realtime system over a TCP/IP connection---you can use the @code{target} |
11489 | command to specify one of the target types configured for @value{GDBN} | |
11490 | (@pxref{Target Commands, ,Commands for managing targets}). | |
c906108c | 11491 | |
a8f24a35 EZ |
11492 | @cindex target architecture |
11493 | It is possible to build @value{GDBN} for several different @dfn{target | |
11494 | architectures}. When @value{GDBN} is built like that, you can choose | |
11495 | one of the available architectures with the @kbd{set architecture} | |
11496 | command. | |
11497 | ||
11498 | @table @code | |
11499 | @kindex set architecture | |
11500 | @kindex show architecture | |
11501 | @item set architecture @var{arch} | |
11502 | This command sets the current target architecture to @var{arch}. The | |
11503 | value of @var{arch} can be @code{"auto"}, in addition to one of the | |
11504 | supported architectures. | |
11505 | ||
11506 | @item show architecture | |
11507 | Show the current target architecture. | |
9c16f35a EZ |
11508 | |
11509 | @item set processor | |
11510 | @itemx processor | |
11511 | @kindex set processor | |
11512 | @kindex show processor | |
11513 | These are alias commands for, respectively, @code{set architecture} | |
11514 | and @code{show architecture}. | |
a8f24a35 EZ |
11515 | @end table |
11516 | ||
c906108c SS |
11517 | @menu |
11518 | * Active Targets:: Active targets | |
11519 | * Target Commands:: Commands for managing targets | |
c906108c SS |
11520 | * Byte Order:: Choosing target byte order |
11521 | * Remote:: Remote debugging | |
96baa820 | 11522 | * KOD:: Kernel Object Display |
c906108c SS |
11523 | |
11524 | @end menu | |
11525 | ||
6d2ebf8b | 11526 | @node Active Targets |
c906108c | 11527 | @section Active targets |
7a292a7a | 11528 | |
c906108c SS |
11529 | @cindex stacking targets |
11530 | @cindex active targets | |
11531 | @cindex multiple targets | |
11532 | ||
c906108c | 11533 | There are three classes of targets: processes, core files, and |
7a292a7a SS |
11534 | executable files. @value{GDBN} can work concurrently on up to three |
11535 | active targets, one in each class. This allows you to (for example) | |
11536 | start a process and inspect its activity without abandoning your work on | |
11537 | a core file. | |
c906108c SS |
11538 | |
11539 | For example, if you execute @samp{gdb a.out}, then the executable file | |
11540 | @code{a.out} is the only active target. If you designate a core file as | |
11541 | well---presumably from a prior run that crashed and coredumped---then | |
11542 | @value{GDBN} has two active targets and uses them in tandem, looking | |
11543 | first in the corefile target, then in the executable file, to satisfy | |
11544 | requests for memory addresses. (Typically, these two classes of target | |
11545 | are complementary, since core files contain only a program's | |
11546 | read-write memory---variables and so on---plus machine status, while | |
11547 | executable files contain only the program text and initialized data.) | |
c906108c SS |
11548 | |
11549 | When you type @code{run}, your executable file becomes an active process | |
7a292a7a SS |
11550 | target as well. When a process target is active, all @value{GDBN} |
11551 | commands requesting memory addresses refer to that target; addresses in | |
11552 | an active core file or executable file target are obscured while the | |
11553 | process target is active. | |
c906108c | 11554 | |
7a292a7a SS |
11555 | Use the @code{core-file} and @code{exec-file} commands to select a new |
11556 | core file or executable target (@pxref{Files, ,Commands to specify | |
c906108c | 11557 | files}). To specify as a target a process that is already running, use |
7a292a7a SS |
11558 | the @code{attach} command (@pxref{Attach, ,Debugging an already-running |
11559 | process}). | |
c906108c | 11560 | |
6d2ebf8b | 11561 | @node Target Commands |
c906108c SS |
11562 | @section Commands for managing targets |
11563 | ||
11564 | @table @code | |
11565 | @item target @var{type} @var{parameters} | |
7a292a7a SS |
11566 | Connects the @value{GDBN} host environment to a target machine or |
11567 | process. A target is typically a protocol for talking to debugging | |
11568 | facilities. You use the argument @var{type} to specify the type or | |
11569 | protocol of the target machine. | |
c906108c SS |
11570 | |
11571 | Further @var{parameters} are interpreted by the target protocol, but | |
11572 | typically include things like device names or host names to connect | |
11573 | with, process numbers, and baud rates. | |
c906108c SS |
11574 | |
11575 | The @code{target} command does not repeat if you press @key{RET} again | |
11576 | after executing the command. | |
11577 | ||
11578 | @kindex help target | |
11579 | @item help target | |
11580 | Displays the names of all targets available. To display targets | |
11581 | currently selected, use either @code{info target} or @code{info files} | |
11582 | (@pxref{Files, ,Commands to specify files}). | |
11583 | ||
11584 | @item help target @var{name} | |
11585 | Describe a particular target, including any parameters necessary to | |
11586 | select it. | |
11587 | ||
11588 | @kindex set gnutarget | |
11589 | @item set gnutarget @var{args} | |
5d161b24 | 11590 | @value{GDBN} uses its own library BFD to read your files. @value{GDBN} |
c906108c | 11591 | knows whether it is reading an @dfn{executable}, |
5d161b24 DB |
11592 | a @dfn{core}, or a @dfn{.o} file; however, you can specify the file format |
11593 | with the @code{set gnutarget} command. Unlike most @code{target} commands, | |
c906108c SS |
11594 | with @code{gnutarget} the @code{target} refers to a program, not a machine. |
11595 | ||
d4f3574e | 11596 | @quotation |
c906108c SS |
11597 | @emph{Warning:} To specify a file format with @code{set gnutarget}, |
11598 | you must know the actual BFD name. | |
d4f3574e | 11599 | @end quotation |
c906108c | 11600 | |
d4f3574e SS |
11601 | @noindent |
11602 | @xref{Files, , Commands to specify files}. | |
c906108c | 11603 | |
5d161b24 | 11604 | @kindex show gnutarget |
c906108c SS |
11605 | @item show gnutarget |
11606 | Use the @code{show gnutarget} command to display what file format | |
11607 | @code{gnutarget} is set to read. If you have not set @code{gnutarget}, | |
11608 | @value{GDBN} will determine the file format for each file automatically, | |
11609 | and @code{show gnutarget} displays @samp{The current BDF target is "auto"}. | |
11610 | @end table | |
11611 | ||
4644b6e3 | 11612 | @cindex common targets |
c906108c SS |
11613 | Here are some common targets (available, or not, depending on the GDB |
11614 | configuration): | |
c906108c SS |
11615 | |
11616 | @table @code | |
4644b6e3 | 11617 | @kindex target |
c906108c | 11618 | @item target exec @var{program} |
4644b6e3 | 11619 | @cindex executable file target |
c906108c SS |
11620 | An executable file. @samp{target exec @var{program}} is the same as |
11621 | @samp{exec-file @var{program}}. | |
11622 | ||
c906108c | 11623 | @item target core @var{filename} |
4644b6e3 | 11624 | @cindex core dump file target |
c906108c SS |
11625 | A core dump file. @samp{target core @var{filename}} is the same as |
11626 | @samp{core-file @var{filename}}. | |
c906108c | 11627 | |
c906108c | 11628 | @item target remote @var{dev} |
4644b6e3 | 11629 | @cindex remote target |
c906108c SS |
11630 | Remote serial target in GDB-specific protocol. The argument @var{dev} |
11631 | specifies what serial device to use for the connection (e.g. | |
11632 | @file{/dev/ttya}). @xref{Remote, ,Remote debugging}. @code{target remote} | |
d4f3574e | 11633 | supports the @code{load} command. This is only useful if you have |
c906108c SS |
11634 | some other way of getting the stub to the target system, and you can put |
11635 | it somewhere in memory where it won't get clobbered by the download. | |
11636 | ||
c906108c | 11637 | @item target sim |
4644b6e3 | 11638 | @cindex built-in simulator target |
2df3850c | 11639 | Builtin CPU simulator. @value{GDBN} includes simulators for most architectures. |
104c1213 | 11640 | In general, |
474c8240 | 11641 | @smallexample |
104c1213 JM |
11642 | target sim |
11643 | load | |
11644 | run | |
474c8240 | 11645 | @end smallexample |
d4f3574e | 11646 | @noindent |
104c1213 | 11647 | works; however, you cannot assume that a specific memory map, device |
d4f3574e | 11648 | drivers, or even basic I/O is available, although some simulators do |
104c1213 JM |
11649 | provide these. For info about any processor-specific simulator details, |
11650 | see the appropriate section in @ref{Embedded Processors, ,Embedded | |
11651 | Processors}. | |
11652 | ||
c906108c SS |
11653 | @end table |
11654 | ||
104c1213 | 11655 | Some configurations may include these targets as well: |
c906108c SS |
11656 | |
11657 | @table @code | |
11658 | ||
c906108c | 11659 | @item target nrom @var{dev} |
4644b6e3 | 11660 | @cindex NetROM ROM emulator target |
c906108c SS |
11661 | NetROM ROM emulator. This target only supports downloading. |
11662 | ||
c906108c SS |
11663 | @end table |
11664 | ||
5d161b24 | 11665 | Different targets are available on different configurations of @value{GDBN}; |
c906108c | 11666 | your configuration may have more or fewer targets. |
c906108c | 11667 | |
721c2651 EZ |
11668 | Many remote targets require you to download the executable's code once |
11669 | you've successfully established a connection. You may wish to control | |
11670 | various aspects of this process, such as the size of the data chunks | |
11671 | used by @value{GDBN} to download program parts to the remote target. | |
a8f24a35 EZ |
11672 | |
11673 | @table @code | |
11674 | @kindex set download-write-size | |
11675 | @item set download-write-size @var{size} | |
11676 | Set the write size used when downloading a program. Only used when | |
11677 | downloading a program onto a remote target. Specify zero or a | |
11678 | negative value to disable blocked writes. The actual size of each | |
11679 | transfer is also limited by the size of the target packet and the | |
11680 | memory cache. | |
11681 | ||
11682 | @kindex show download-write-size | |
11683 | @item show download-write-size | |
721c2651 | 11684 | @kindex show download-write-size |
a8f24a35 | 11685 | Show the current value of the write size. |
721c2651 EZ |
11686 | |
11687 | @item set hash | |
11688 | @kindex set hash@r{, for remote monitors} | |
11689 | @cindex hash mark while downloading | |
11690 | This command controls whether a hash mark @samp{#} is displayed while | |
11691 | downloading a file to the remote monitor. If on, a hash mark is | |
11692 | displayed after each S-record is successfully downloaded to the | |
11693 | monitor. | |
11694 | ||
11695 | @item show hash | |
11696 | @kindex show hash@r{, for remote monitors} | |
11697 | Show the current status of displaying the hash mark. | |
11698 | ||
11699 | @item set debug monitor | |
11700 | @kindex set debug monitor | |
11701 | @cindex display remote monitor communications | |
11702 | Enable or disable display of communications messages between | |
11703 | @value{GDBN} and the remote monitor. | |
11704 | ||
11705 | @item show debug monitor | |
11706 | @kindex show debug monitor | |
11707 | Show the current status of displaying communications between | |
11708 | @value{GDBN} and the remote monitor. | |
a8f24a35 | 11709 | @end table |
c906108c SS |
11710 | |
11711 | @table @code | |
11712 | ||
11713 | @kindex load @var{filename} | |
11714 | @item load @var{filename} | |
c906108c SS |
11715 | Depending on what remote debugging facilities are configured into |
11716 | @value{GDBN}, the @code{load} command may be available. Where it exists, it | |
11717 | is meant to make @var{filename} (an executable) available for debugging | |
11718 | on the remote system---by downloading, or dynamic linking, for example. | |
11719 | @code{load} also records the @var{filename} symbol table in @value{GDBN}, like | |
11720 | the @code{add-symbol-file} command. | |
11721 | ||
11722 | If your @value{GDBN} does not have a @code{load} command, attempting to | |
11723 | execute it gets the error message ``@code{You can't do that when your | |
11724 | target is @dots{}}'' | |
c906108c SS |
11725 | |
11726 | The file is loaded at whatever address is specified in the executable. | |
11727 | For some object file formats, you can specify the load address when you | |
11728 | link the program; for other formats, like a.out, the object file format | |
11729 | specifies a fixed address. | |
11730 | @c FIXME! This would be a good place for an xref to the GNU linker doc. | |
11731 | ||
c906108c SS |
11732 | @code{load} does not repeat if you press @key{RET} again after using it. |
11733 | @end table | |
11734 | ||
6d2ebf8b | 11735 | @node Byte Order |
c906108c | 11736 | @section Choosing target byte order |
7a292a7a | 11737 | |
c906108c SS |
11738 | @cindex choosing target byte order |
11739 | @cindex target byte order | |
c906108c | 11740 | |
172c2a43 | 11741 | Some types of processors, such as the MIPS, PowerPC, and Renesas SH, |
c906108c SS |
11742 | offer the ability to run either big-endian or little-endian byte |
11743 | orders. Usually the executable or symbol will include a bit to | |
11744 | designate the endian-ness, and you will not need to worry about | |
11745 | which to use. However, you may still find it useful to adjust | |
d4f3574e | 11746 | @value{GDBN}'s idea of processor endian-ness manually. |
c906108c SS |
11747 | |
11748 | @table @code | |
4644b6e3 | 11749 | @kindex set endian |
c906108c SS |
11750 | @item set endian big |
11751 | Instruct @value{GDBN} to assume the target is big-endian. | |
11752 | ||
c906108c SS |
11753 | @item set endian little |
11754 | Instruct @value{GDBN} to assume the target is little-endian. | |
11755 | ||
c906108c SS |
11756 | @item set endian auto |
11757 | Instruct @value{GDBN} to use the byte order associated with the | |
11758 | executable. | |
11759 | ||
11760 | @item show endian | |
11761 | Display @value{GDBN}'s current idea of the target byte order. | |
11762 | ||
11763 | @end table | |
11764 | ||
11765 | Note that these commands merely adjust interpretation of symbolic | |
11766 | data on the host, and that they have absolutely no effect on the | |
11767 | target system. | |
11768 | ||
6d2ebf8b | 11769 | @node Remote |
c906108c SS |
11770 | @section Remote debugging |
11771 | @cindex remote debugging | |
11772 | ||
11773 | If you are trying to debug a program running on a machine that cannot run | |
5d161b24 DB |
11774 | @value{GDBN} in the usual way, it is often useful to use remote debugging. |
11775 | For example, you might use remote debugging on an operating system kernel, | |
c906108c SS |
11776 | or on a small system which does not have a general purpose operating system |
11777 | powerful enough to run a full-featured debugger. | |
11778 | ||
11779 | Some configurations of @value{GDBN} have special serial or TCP/IP interfaces | |
11780 | to make this work with particular debugging targets. In addition, | |
5d161b24 | 11781 | @value{GDBN} comes with a generic serial protocol (specific to @value{GDBN}, |
c906108c SS |
11782 | but not specific to any particular target system) which you can use if you |
11783 | write the remote stubs---the code that runs on the remote system to | |
11784 | communicate with @value{GDBN}. | |
11785 | ||
11786 | Other remote targets may be available in your | |
11787 | configuration of @value{GDBN}; use @code{help target} to list them. | |
c906108c | 11788 | |
c45da7e6 EZ |
11789 | Once you've connected to the remote target, @value{GDBN} allows you to |
11790 | send arbitrary commands to the remote monitor: | |
11791 | ||
11792 | @table @code | |
11793 | @item remote @var{command} | |
11794 | @kindex remote@r{, a command} | |
11795 | @cindex send command to remote monitor | |
11796 | Send an arbitrary @var{command} string to the remote monitor. | |
11797 | @end table | |
11798 | ||
11799 | ||
6f05cf9f AC |
11800 | @node KOD |
11801 | @section Kernel Object Display | |
6f05cf9f | 11802 | @cindex kernel object display |
6f05cf9f AC |
11803 | @cindex KOD |
11804 | ||
11805 | Some targets support kernel object display. Using this facility, | |
11806 | @value{GDBN} communicates specially with the underlying operating system | |
11807 | and can display information about operating system-level objects such as | |
11808 | mutexes and other synchronization objects. Exactly which objects can be | |
11809 | displayed is determined on a per-OS basis. | |
11810 | ||
3bbe9696 | 11811 | @kindex set os |
6f05cf9f AC |
11812 | Use the @code{set os} command to set the operating system. This tells |
11813 | @value{GDBN} which kernel object display module to initialize: | |
11814 | ||
474c8240 | 11815 | @smallexample |
6f05cf9f | 11816 | (@value{GDBP}) set os cisco |
474c8240 | 11817 | @end smallexample |
6f05cf9f | 11818 | |
3bbe9696 EZ |
11819 | @kindex show os |
11820 | The associated command @code{show os} displays the operating system | |
11821 | set with the @code{set os} command; if no operating system has been | |
11822 | set, @code{show os} will display an empty string @samp{""}. | |
11823 | ||
6f05cf9f AC |
11824 | If @code{set os} succeeds, @value{GDBN} will display some information |
11825 | about the operating system, and will create a new @code{info} command | |
11826 | which can be used to query the target. The @code{info} command is named | |
11827 | after the operating system: | |
c906108c | 11828 | |
3bbe9696 | 11829 | @kindex info cisco |
474c8240 | 11830 | @smallexample |
6f05cf9f AC |
11831 | (@value{GDBP}) info cisco |
11832 | List of Cisco Kernel Objects | |
11833 | Object Description | |
11834 | any Any and all objects | |
474c8240 | 11835 | @end smallexample |
6f05cf9f AC |
11836 | |
11837 | Further subcommands can be used to query about particular objects known | |
11838 | by the kernel. | |
11839 | ||
3bbe9696 EZ |
11840 | There is currently no way to determine whether a given operating |
11841 | system is supported other than to try setting it with @kbd{set os | |
11842 | @var{name}}, where @var{name} is the name of the operating system you | |
11843 | want to try. | |
6f05cf9f AC |
11844 | |
11845 | ||
11846 | @node Remote Debugging | |
11847 | @chapter Debugging remote programs | |
11848 | ||
6b2f586d | 11849 | @menu |
07f31aa6 | 11850 | * Connecting:: Connecting to a remote target |
6b2f586d AC |
11851 | * Server:: Using the gdbserver program |
11852 | * NetWare:: Using the gdbserve.nlm program | |
501eef12 | 11853 | * Remote configuration:: Remote configuration |
6b2f586d | 11854 | * remote stub:: Implementing a remote stub |
6b2f586d AC |
11855 | @end menu |
11856 | ||
07f31aa6 DJ |
11857 | @node Connecting |
11858 | @section Connecting to a remote target | |
11859 | ||
11860 | On the @value{GDBN} host machine, you will need an unstripped copy of | |
11861 | your program, since @value{GDBN} needs symobl and debugging information. | |
11862 | Start up @value{GDBN} as usual, using the name of the local copy of your | |
11863 | program as the first argument. | |
11864 | ||
11865 | @cindex serial line, @code{target remote} | |
11866 | If you're using a serial line, you may want to give @value{GDBN} the | |
11867 | @w{@samp{--baud}} option, or use the @code{set remotebaud} command | |
9c16f35a EZ |
11868 | (@pxref{Remote configuration, set remotebaud}) before the |
11869 | @code{target} command. | |
07f31aa6 DJ |
11870 | |
11871 | After that, use @code{target remote} to establish communications with | |
11872 | the target machine. Its argument specifies how to communicate---either | |
11873 | via a devicename attached to a direct serial line, or a TCP or UDP port | |
11874 | (possibly to a terminal server which in turn has a serial line to the | |
11875 | target). For example, to use a serial line connected to the device | |
11876 | named @file{/dev/ttyb}: | |
11877 | ||
11878 | @smallexample | |
11879 | target remote /dev/ttyb | |
11880 | @end smallexample | |
11881 | ||
11882 | @cindex TCP port, @code{target remote} | |
11883 | To use a TCP connection, use an argument of the form | |
11884 | @code{@var{host}:@var{port}} or @code{tcp:@var{host}:@var{port}}. | |
11885 | For example, to connect to port 2828 on a | |
11886 | terminal server named @code{manyfarms}: | |
11887 | ||
11888 | @smallexample | |
11889 | target remote manyfarms:2828 | |
11890 | @end smallexample | |
11891 | ||
11892 | If your remote target is actually running on the same machine as | |
11893 | your debugger session (e.g.@: a simulator of your target running on | |
11894 | the same host), you can omit the hostname. For example, to connect | |
11895 | to port 1234 on your local machine: | |
11896 | ||
11897 | @smallexample | |
11898 | target remote :1234 | |
11899 | @end smallexample | |
11900 | @noindent | |
11901 | ||
11902 | Note that the colon is still required here. | |
11903 | ||
11904 | @cindex UDP port, @code{target remote} | |
11905 | To use a UDP connection, use an argument of the form | |
11906 | @code{udp:@var{host}:@var{port}}. For example, to connect to UDP port 2828 | |
11907 | on a terminal server named @code{manyfarms}: | |
11908 | ||
11909 | @smallexample | |
11910 | target remote udp:manyfarms:2828 | |
11911 | @end smallexample | |
11912 | ||
11913 | When using a UDP connection for remote debugging, you should keep in mind | |
11914 | that the `U' stands for ``Unreliable''. UDP can silently drop packets on | |
11915 | busy or unreliable networks, which will cause havoc with your debugging | |
11916 | session. | |
11917 | ||
11918 | Now you can use all the usual commands to examine and change data and to | |
11919 | step and continue the remote program. | |
11920 | ||
11921 | @cindex interrupting remote programs | |
11922 | @cindex remote programs, interrupting | |
11923 | Whenever @value{GDBN} is waiting for the remote program, if you type the | |
11924 | interrupt character (often @key{C-C}), @value{GDBN} attempts to stop the | |
11925 | program. This may or may not succeed, depending in part on the hardware | |
11926 | and the serial drivers the remote system uses. If you type the | |
11927 | interrupt character once again, @value{GDBN} displays this prompt: | |
11928 | ||
11929 | @smallexample | |
11930 | Interrupted while waiting for the program. | |
11931 | Give up (and stop debugging it)? (y or n) | |
11932 | @end smallexample | |
11933 | ||
11934 | If you type @kbd{y}, @value{GDBN} abandons the remote debugging session. | |
11935 | (If you decide you want to try again later, you can use @samp{target | |
11936 | remote} again to connect once more.) If you type @kbd{n}, @value{GDBN} | |
11937 | goes back to waiting. | |
11938 | ||
11939 | @table @code | |
11940 | @kindex detach (remote) | |
11941 | @item detach | |
11942 | When you have finished debugging the remote program, you can use the | |
11943 | @code{detach} command to release it from @value{GDBN} control. | |
11944 | Detaching from the target normally resumes its execution, but the results | |
11945 | will depend on your particular remote stub. After the @code{detach} | |
11946 | command, @value{GDBN} is free to connect to another target. | |
11947 | ||
11948 | @kindex disconnect | |
11949 | @item disconnect | |
11950 | The @code{disconnect} command behaves like @code{detach}, except that | |
11951 | the target is generally not resumed. It will wait for @value{GDBN} | |
11952 | (this instance or another one) to connect and continue debugging. After | |
11953 | the @code{disconnect} command, @value{GDBN} is again free to connect to | |
11954 | another target. | |
09d4efe1 EZ |
11955 | |
11956 | @cindex send command to remote monitor | |
11957 | @kindex monitor | |
11958 | @item monitor @var{cmd} | |
11959 | This command allows you to send commands directly to the remote | |
11960 | monitor. | |
07f31aa6 DJ |
11961 | @end table |
11962 | ||
6f05cf9f AC |
11963 | @node Server |
11964 | @section Using the @code{gdbserver} program | |
11965 | ||
11966 | @kindex gdbserver | |
11967 | @cindex remote connection without stubs | |
11968 | @code{gdbserver} is a control program for Unix-like systems, which | |
11969 | allows you to connect your program with a remote @value{GDBN} via | |
11970 | @code{target remote}---but without linking in the usual debugging stub. | |
11971 | ||
11972 | @code{gdbserver} is not a complete replacement for the debugging stubs, | |
11973 | because it requires essentially the same operating-system facilities | |
11974 | that @value{GDBN} itself does. In fact, a system that can run | |
11975 | @code{gdbserver} to connect to a remote @value{GDBN} could also run | |
11976 | @value{GDBN} locally! @code{gdbserver} is sometimes useful nevertheless, | |
11977 | because it is a much smaller program than @value{GDBN} itself. It is | |
11978 | also easier to port than all of @value{GDBN}, so you may be able to get | |
11979 | started more quickly on a new system by using @code{gdbserver}. | |
11980 | Finally, if you develop code for real-time systems, you may find that | |
11981 | the tradeoffs involved in real-time operation make it more convenient to | |
11982 | do as much development work as possible on another system, for example | |
11983 | by cross-compiling. You can use @code{gdbserver} to make a similar | |
11984 | choice for debugging. | |
11985 | ||
11986 | @value{GDBN} and @code{gdbserver} communicate via either a serial line | |
11987 | or a TCP connection, using the standard @value{GDBN} remote serial | |
11988 | protocol. | |
11989 | ||
11990 | @table @emph | |
11991 | @item On the target machine, | |
11992 | you need to have a copy of the program you want to debug. | |
11993 | @code{gdbserver} does not need your program's symbol table, so you can | |
11994 | strip the program if necessary to save space. @value{GDBN} on the host | |
11995 | system does all the symbol handling. | |
11996 | ||
11997 | To use the server, you must tell it how to communicate with @value{GDBN}; | |
56460a61 | 11998 | the name of your program; and the arguments for your program. The usual |
6f05cf9f AC |
11999 | syntax is: |
12000 | ||
12001 | @smallexample | |
12002 | target> gdbserver @var{comm} @var{program} [ @var{args} @dots{} ] | |
12003 | @end smallexample | |
12004 | ||
12005 | @var{comm} is either a device name (to use a serial line) or a TCP | |
12006 | hostname and portnumber. For example, to debug Emacs with the argument | |
12007 | @samp{foo.txt} and communicate with @value{GDBN} over the serial port | |
12008 | @file{/dev/com1}: | |
12009 | ||
12010 | @smallexample | |
12011 | target> gdbserver /dev/com1 emacs foo.txt | |
12012 | @end smallexample | |
12013 | ||
12014 | @code{gdbserver} waits passively for the host @value{GDBN} to communicate | |
12015 | with it. | |
12016 | ||
12017 | To use a TCP connection instead of a serial line: | |
12018 | ||
12019 | @smallexample | |
12020 | target> gdbserver host:2345 emacs foo.txt | |
12021 | @end smallexample | |
12022 | ||
12023 | The only difference from the previous example is the first argument, | |
12024 | specifying that you are communicating with the host @value{GDBN} via | |
12025 | TCP. The @samp{host:2345} argument means that @code{gdbserver} is to | |
12026 | expect a TCP connection from machine @samp{host} to local TCP port 2345. | |
12027 | (Currently, the @samp{host} part is ignored.) You can choose any number | |
12028 | you want for the port number as long as it does not conflict with any | |
12029 | TCP ports already in use on the target system (for example, @code{23} is | |
12030 | reserved for @code{telnet}).@footnote{If you choose a port number that | |
12031 | conflicts with another service, @code{gdbserver} prints an error message | |
12032 | and exits.} You must use the same port number with the host @value{GDBN} | |
12033 | @code{target remote} command. | |
12034 | ||
56460a61 DJ |
12035 | On some targets, @code{gdbserver} can also attach to running programs. |
12036 | This is accomplished via the @code{--attach} argument. The syntax is: | |
12037 | ||
12038 | @smallexample | |
12039 | target> gdbserver @var{comm} --attach @var{pid} | |
12040 | @end smallexample | |
12041 | ||
12042 | @var{pid} is the process ID of a currently running process. It isn't necessary | |
12043 | to point @code{gdbserver} at a binary for the running process. | |
12044 | ||
b1fe9455 DJ |
12045 | @pindex pidof |
12046 | @cindex attach to a program by name | |
12047 | You can debug processes by name instead of process ID if your target has the | |
12048 | @code{pidof} utility: | |
12049 | ||
12050 | @smallexample | |
12051 | target> gdbserver @var{comm} --attach `pidof @var{PROGRAM}` | |
12052 | @end smallexample | |
12053 | ||
12054 | In case more than one copy of @var{PROGRAM} is running, or @var{PROGRAM} | |
12055 | has multiple threads, most versions of @code{pidof} support the | |
12056 | @code{-s} option to only return the first process ID. | |
12057 | ||
07f31aa6 DJ |
12058 | @item On the host machine, |
12059 | connect to your target (@pxref{Connecting,,Connecting to a remote target}). | |
6f05cf9f AC |
12060 | For TCP connections, you must start up @code{gdbserver} prior to using |
12061 | the @code{target remote} command. Otherwise you may get an error whose | |
12062 | text depends on the host system, but which usually looks something like | |
07f31aa6 | 12063 | @samp{Connection refused}. You don't need to use the @code{load} |
397ca115 EZ |
12064 | command in @value{GDBN} when using @code{gdbserver}, since the program is |
12065 | already on the target. However, if you want to load the symbols (as | |
12066 | you normally would), do that with the @code{file} command, and issue | |
12067 | it @emph{before} connecting to the server; otherwise, you will get an | |
12068 | error message saying @code{"Program is already running"}, since the | |
12069 | program is considered running after the connection. | |
07f31aa6 | 12070 | |
6f05cf9f AC |
12071 | @end table |
12072 | ||
12073 | @node NetWare | |
12074 | @section Using the @code{gdbserve.nlm} program | |
12075 | ||
12076 | @kindex gdbserve.nlm | |
12077 | @code{gdbserve.nlm} is a control program for NetWare systems, which | |
12078 | allows you to connect your program with a remote @value{GDBN} via | |
12079 | @code{target remote}. | |
12080 | ||
12081 | @value{GDBN} and @code{gdbserve.nlm} communicate via a serial line, | |
12082 | using the standard @value{GDBN} remote serial protocol. | |
12083 | ||
12084 | @table @emph | |
12085 | @item On the target machine, | |
12086 | you need to have a copy of the program you want to debug. | |
12087 | @code{gdbserve.nlm} does not need your program's symbol table, so you | |
12088 | can strip the program if necessary to save space. @value{GDBN} on the | |
12089 | host system does all the symbol handling. | |
12090 | ||
12091 | To use the server, you must tell it how to communicate with | |
12092 | @value{GDBN}; the name of your program; and the arguments for your | |
12093 | program. The syntax is: | |
12094 | ||
12095 | @smallexample | |
12096 | load gdbserve [ BOARD=@var{board} ] [ PORT=@var{port} ] | |
12097 | [ BAUD=@var{baud} ] @var{program} [ @var{args} @dots{} ] | |
12098 | @end smallexample | |
12099 | ||
12100 | @var{board} and @var{port} specify the serial line; @var{baud} specifies | |
12101 | the baud rate used by the connection. @var{port} and @var{node} default | |
12102 | to 0, @var{baud} defaults to 9600@dmn{bps}. | |
12103 | ||
12104 | For example, to debug Emacs with the argument @samp{foo.txt}and | |
12105 | communicate with @value{GDBN} over serial port number 2 or board 1 | |
12106 | using a 19200@dmn{bps} connection: | |
12107 | ||
12108 | @smallexample | |
12109 | load gdbserve BOARD=1 PORT=2 BAUD=19200 emacs foo.txt | |
12110 | @end smallexample | |
12111 | ||
07f31aa6 DJ |
12112 | @item |
12113 | On the @value{GDBN} host machine, connect to your target (@pxref{Connecting,, | |
12114 | Connecting to a remote target}). | |
6f05cf9f | 12115 | |
6f05cf9f AC |
12116 | @end table |
12117 | ||
501eef12 AC |
12118 | @node Remote configuration |
12119 | @section Remote configuration | |
12120 | ||
9c16f35a EZ |
12121 | @kindex set remote |
12122 | @kindex show remote | |
12123 | This section documents the configuration options available when | |
12124 | debugging remote programs. For the options related to the File I/O | |
12125 | extensions of the remote protocol, see @ref{The system call, | |
12126 | system-call-allowed}. | |
501eef12 AC |
12127 | |
12128 | @table @code | |
9c16f35a EZ |
12129 | @item set remoteaddresssize @var{bits} |
12130 | @cindex adress size for remote targets | |
12131 | @cindex bits in remote address | |
12132 | Set the maximum size of address in a memory packet to the specified | |
12133 | number of bits. @value{GDBN} will mask off the address bits above | |
12134 | that number, when it passes addresses to the remote target. The | |
12135 | default value is the number of bits in the target's address. | |
12136 | ||
12137 | @item show remoteaddresssize | |
12138 | Show the current value of remote address size in bits. | |
12139 | ||
12140 | @item set remotebaud @var{n} | |
12141 | @cindex baud rate for remote targets | |
12142 | Set the baud rate for the remote serial I/O to @var{n} baud. The | |
12143 | value is used to set the speed of the serial port used for debugging | |
12144 | remote targets. | |
12145 | ||
12146 | @item show remotebaud | |
12147 | Show the current speed of the remote connection. | |
12148 | ||
12149 | @item set remotebreak | |
12150 | @cindex interrupt remote programs | |
12151 | @cindex BREAK signal instead of Ctrl-C | |
9a6253be | 12152 | @anchor{set remotebreak} |
9c16f35a EZ |
12153 | If set to on, @value{GDBN} sends a @code{BREAK} signal to the remote |
12154 | when you press the @key{Ctrl-C} key to interrupt the program running | |
9a7a1b36 | 12155 | on the remote. If set to off, @value{GDBN} sends the @samp{Ctrl-C} |
9c16f35a EZ |
12156 | character instead. The default is off, since most remote systems |
12157 | expect to see @samp{Ctrl-C} as the interrupt signal. | |
12158 | ||
12159 | @item show remotebreak | |
12160 | Show whether @value{GDBN} sends @code{BREAK} or @samp{Ctrl-C} to | |
12161 | interrupt the remote program. | |
12162 | ||
12163 | @item set remotedebug | |
12164 | @cindex debug remote protocol | |
12165 | @cindex remote protocol debugging | |
12166 | @cindex display remote packets | |
12167 | Control the debugging of the remote protocol. When enabled, each | |
12168 | packet sent to or received from the remote target is displayed. The | |
12169 | defaults is off. | |
12170 | ||
12171 | @item show remotedebug | |
12172 | Show the current setting of the remote protocol debugging. | |
12173 | ||
12174 | @item set remotedevice @var{device} | |
12175 | @cindex serial port name | |
12176 | Set the name of the serial port through which to communicate to the | |
12177 | remote target to @var{device}. This is the device used by | |
12178 | @value{GDBN} to open the serial communications line to the remote | |
12179 | target. There's no default, so you must set a valid port name for the | |
12180 | remote serial communications to work. (Some varieties of the | |
12181 | @code{target} command accept the port name as part of their | |
12182 | arguments.) | |
12183 | ||
12184 | @item show remotedevice | |
12185 | Show the current name of the serial port. | |
12186 | ||
12187 | @item set remotelogbase @var{base} | |
12188 | Set the base (a.k.a.@: radix) of logging serial protocol | |
12189 | communications to @var{base}. Supported values of @var{base} are: | |
12190 | @code{ascii}, @code{octal}, and @code{hex}. The default is | |
12191 | @code{ascii}. | |
12192 | ||
12193 | @item show remotelogbase | |
12194 | Show the current setting of the radix for logging remote serial | |
12195 | protocol. | |
12196 | ||
12197 | @item set remotelogfile @var{file} | |
12198 | @cindex record serial communications on file | |
12199 | Record remote serial communications on the named @var{file}. The | |
12200 | default is not to record at all. | |
12201 | ||
12202 | @item show remotelogfile. | |
12203 | Show the current setting of the file name on which to record the | |
12204 | serial communications. | |
12205 | ||
12206 | @item set remotetimeout @var{num} | |
12207 | @cindex timeout for serial communications | |
12208 | @cindex remote timeout | |
12209 | Set the timeout limit to wait for the remote target to respond to | |
12210 | @var{num} seconds. The default is 2 seconds. | |
12211 | ||
12212 | @item show remotetimeout | |
12213 | Show the current number of seconds to wait for the remote target | |
12214 | responses. | |
12215 | ||
12216 | @cindex limit hardware breakpoints and watchpoints | |
12217 | @cindex remote target, limit break- and watchpoints | |
501eef12 AC |
12218 | @anchor{set remote hardware-watchpoint-limit} |
12219 | @anchor{set remote hardware-breakpoint-limit} | |
12220 | @item set remote hardware-watchpoint-limit @var{limit} | |
12221 | @itemx set remote hardware-breakpoint-limit @var{limit} | |
12222 | Restrict @value{GDBN} to using @var{limit} remote hardware breakpoint or | |
12223 | watchpoints. A limit of -1, the default, is treated as unlimited. | |
9c16f35a EZ |
12224 | |
12225 | @item set remote fetch-register-packet | |
12226 | @itemx set remote set-register-packet | |
12227 | @itemx set remote P-packet | |
12228 | @itemx set remote p-packet | |
12229 | @cindex P-packet | |
12230 | @cindex fetch registers from remote targets | |
12231 | @cindex set registers in remote targets | |
12232 | Determine whether @value{GDBN} can set and fetch registers from the | |
12233 | remote target using the @samp{P} packets. The default depends on the | |
12234 | remote stub's support of the @samp{P} packets (@value{GDBN} queries | |
12235 | the stub when this packet is first required). | |
12236 | ||
12237 | @item show remote fetch-register-packet | |
12238 | @itemx show remote set-register-packet | |
12239 | @itemx show remote P-packet | |
12240 | @itemx show remote p-packet | |
12241 | Show the current setting of using the @samp{P} packets for setting and | |
12242 | fetching registers from the remote target. | |
12243 | ||
12244 | @cindex binary downloads | |
12245 | @cindex X-packet | |
12246 | @item set remote binary-download-packet | |
12247 | @itemx set remote X-packet | |
12248 | Determine whether @value{GDBN} sends downloads in binary mode using | |
12249 | the @samp{X} packets. The default is on. | |
12250 | ||
12251 | @item show remote binary-download-packet | |
12252 | @itemx show remote X-packet | |
12253 | Show the current setting of using the @samp{X} packets for binary | |
12254 | downloads. | |
12255 | ||
12256 | @item set remote read-aux-vector-packet | |
12257 | @cindex auxiliary vector of remote target | |
12258 | @cindex @code{auxv}, and remote targets | |
12259 | Set the use of the remote protocol's @samp{qPart:auxv:read} (target | |
12260 | auxiliary vector read) request. This request is used to fetch the | |
721c2651 EZ |
12261 | remote target's @dfn{auxiliary vector}, see @ref{OS Information, |
12262 | Auxiliary Vector}. The default setting depends on the remote stub's | |
12263 | support of this request (@value{GDBN} queries the stub when this | |
12264 | request is first required). @xref{General Query Packets, qPart}, for | |
12265 | more information about this request. | |
9c16f35a EZ |
12266 | |
12267 | @item show remote read-aux-vector-packet | |
12268 | Show the current setting of use of the @samp{qPart:auxv:read} request. | |
12269 | ||
12270 | @item set remote symbol-lookup-packet | |
12271 | @cindex remote symbol lookup request | |
12272 | Set the use of the remote protocol's @samp{qSymbol} (target symbol | |
12273 | lookup) request. This request is used to communicate symbol | |
12274 | information to the remote target, e.g., whenever a new shared library | |
12275 | is loaded by the remote (@pxref{Files, shared libraries}). The | |
12276 | default setting depends on the remote stub's support of this request | |
12277 | (@value{GDBN} queries the stub when this request is first required). | |
12278 | @xref{General Query Packets, qSymbol}, for more information about this | |
12279 | request. | |
12280 | ||
12281 | @item show remote symbol-lookup-packet | |
12282 | Show the current setting of use of the @samp{qSymbol} request. | |
12283 | ||
12284 | @item set remote verbose-resume-packet | |
12285 | @cindex resume remote target | |
12286 | @cindex signal thread, and remote targets | |
12287 | @cindex single-step thread, and remote targets | |
12288 | @cindex thread-specific operations on remote targets | |
12289 | Set the use of the remote protocol's @samp{vCont} (descriptive resume) | |
12290 | request. This request is used to resume specific threads in the | |
12291 | remote target, and to single-step or signal them. The default setting | |
12292 | depends on the remote stub's support of this request (@value{GDBN} | |
12293 | queries the stub when this request is first required). This setting | |
12294 | affects debugging of multithreaded programs: if @samp{vCont} cannot be | |
12295 | used, @value{GDBN} might be unable to single-step a specific thread, | |
12296 | especially under @code{set scheduler-locking off}; it is also | |
12297 | impossible to pause a specific thread. @xref{Packets, vCont}, for | |
12298 | more details. | |
12299 | ||
12300 | @item show remote verbose-resume-packet | |
12301 | Show the current setting of use of the @samp{vCont} request | |
12302 | ||
12303 | @item set remote software-breakpoint-packet | |
12304 | @itemx set remote hardware-breakpoint-packet | |
12305 | @itemx set remote write-watchpoint-packet | |
12306 | @itemx set remote read-watchpoint-packet | |
12307 | @itemx set remote access-watchpoint-packet | |
12308 | @itemx set remote Z-packet | |
12309 | @cindex Z-packet | |
12310 | @cindex remote hardware breakpoints and watchpoints | |
12311 | These commands enable or disable the use of @samp{Z} packets for | |
12312 | setting breakpoints and watchpoints in the remote target. The default | |
12313 | depends on the remote stub's support of the @samp{Z} packets | |
12314 | (@value{GDBN} queries the stub when each packet is first required). | |
12315 | The command @code{set remote Z-packet}, kept for back-compatibility, | |
12316 | turns on or off all the features that require the use of @samp{Z} | |
12317 | packets. | |
12318 | ||
12319 | @item show remote software-breakpoint-packet | |
12320 | @itemx show remote hardware-breakpoint-packet | |
12321 | @itemx show remote write-watchpoint-packet | |
12322 | @itemx show remote read-watchpoint-packet | |
12323 | @itemx show remote access-watchpoint-packet | |
12324 | @itemx show remote Z-packet | |
12325 | Show the current setting of @samp{Z} packets usage. | |
0abb7bc7 EZ |
12326 | |
12327 | @item set remote get-thread-local-storage-address | |
12328 | @kindex set remote get-thread-local-storage-address | |
12329 | @cindex thread local storage of remote targets | |
12330 | This command enables or disables the use of the @samp{qGetTLSAddr} | |
12331 | (Get Thread Local Storage Address) request packet. The default | |
12332 | depends on whether the remote stub supports this request. | |
12333 | @xref{General Query Packets, qGetTLSAddr}, for more details about this | |
12334 | packet. | |
12335 | ||
12336 | @item show remote get-thread-local-storage-address | |
12337 | @kindex show remote get-thread-local-storage-address | |
12338 | Show the current setting of @samp{qGetTLSAddr} packet usage. | |
501eef12 AC |
12339 | @end table |
12340 | ||
6f05cf9f AC |
12341 | @node remote stub |
12342 | @section Implementing a remote stub | |
7a292a7a | 12343 | |
8e04817f AC |
12344 | @cindex debugging stub, example |
12345 | @cindex remote stub, example | |
12346 | @cindex stub example, remote debugging | |
12347 | The stub files provided with @value{GDBN} implement the target side of the | |
12348 | communication protocol, and the @value{GDBN} side is implemented in the | |
12349 | @value{GDBN} source file @file{remote.c}. Normally, you can simply allow | |
12350 | these subroutines to communicate, and ignore the details. (If you're | |
12351 | implementing your own stub file, you can still ignore the details: start | |
12352 | with one of the existing stub files. @file{sparc-stub.c} is the best | |
12353 | organized, and therefore the easiest to read.) | |
12354 | ||
104c1213 JM |
12355 | @cindex remote serial debugging, overview |
12356 | To debug a program running on another machine (the debugging | |
12357 | @dfn{target} machine), you must first arrange for all the usual | |
12358 | prerequisites for the program to run by itself. For example, for a C | |
12359 | program, you need: | |
c906108c | 12360 | |
104c1213 JM |
12361 | @enumerate |
12362 | @item | |
12363 | A startup routine to set up the C runtime environment; these usually | |
12364 | have a name like @file{crt0}. The startup routine may be supplied by | |
12365 | your hardware supplier, or you may have to write your own. | |
96baa820 | 12366 | |
5d161b24 | 12367 | @item |
d4f3574e | 12368 | A C subroutine library to support your program's |
104c1213 | 12369 | subroutine calls, notably managing input and output. |
96baa820 | 12370 | |
104c1213 JM |
12371 | @item |
12372 | A way of getting your program to the other machine---for example, a | |
12373 | download program. These are often supplied by the hardware | |
12374 | manufacturer, but you may have to write your own from hardware | |
12375 | documentation. | |
12376 | @end enumerate | |
96baa820 | 12377 | |
104c1213 JM |
12378 | The next step is to arrange for your program to use a serial port to |
12379 | communicate with the machine where @value{GDBN} is running (the @dfn{host} | |
12380 | machine). In general terms, the scheme looks like this: | |
96baa820 | 12381 | |
104c1213 JM |
12382 | @table @emph |
12383 | @item On the host, | |
12384 | @value{GDBN} already understands how to use this protocol; when everything | |
12385 | else is set up, you can simply use the @samp{target remote} command | |
12386 | (@pxref{Targets,,Specifying a Debugging Target}). | |
12387 | ||
12388 | @item On the target, | |
12389 | you must link with your program a few special-purpose subroutines that | |
12390 | implement the @value{GDBN} remote serial protocol. The file containing these | |
12391 | subroutines is called a @dfn{debugging stub}. | |
12392 | ||
12393 | On certain remote targets, you can use an auxiliary program | |
12394 | @code{gdbserver} instead of linking a stub into your program. | |
12395 | @xref{Server,,Using the @code{gdbserver} program}, for details. | |
12396 | @end table | |
96baa820 | 12397 | |
104c1213 JM |
12398 | The debugging stub is specific to the architecture of the remote |
12399 | machine; for example, use @file{sparc-stub.c} to debug programs on | |
12400 | @sc{sparc} boards. | |
96baa820 | 12401 | |
104c1213 JM |
12402 | @cindex remote serial stub list |
12403 | These working remote stubs are distributed with @value{GDBN}: | |
96baa820 | 12404 | |
104c1213 JM |
12405 | @table @code |
12406 | ||
12407 | @item i386-stub.c | |
41afff9a | 12408 | @cindex @file{i386-stub.c} |
104c1213 JM |
12409 | @cindex Intel |
12410 | @cindex i386 | |
12411 | For Intel 386 and compatible architectures. | |
12412 | ||
12413 | @item m68k-stub.c | |
41afff9a | 12414 | @cindex @file{m68k-stub.c} |
104c1213 JM |
12415 | @cindex Motorola 680x0 |
12416 | @cindex m680x0 | |
12417 | For Motorola 680x0 architectures. | |
12418 | ||
12419 | @item sh-stub.c | |
41afff9a | 12420 | @cindex @file{sh-stub.c} |
172c2a43 | 12421 | @cindex Renesas |
104c1213 | 12422 | @cindex SH |
172c2a43 | 12423 | For Renesas SH architectures. |
104c1213 JM |
12424 | |
12425 | @item sparc-stub.c | |
41afff9a | 12426 | @cindex @file{sparc-stub.c} |
104c1213 JM |
12427 | @cindex Sparc |
12428 | For @sc{sparc} architectures. | |
12429 | ||
12430 | @item sparcl-stub.c | |
41afff9a | 12431 | @cindex @file{sparcl-stub.c} |
104c1213 JM |
12432 | @cindex Fujitsu |
12433 | @cindex SparcLite | |
12434 | For Fujitsu @sc{sparclite} architectures. | |
12435 | ||
12436 | @end table | |
12437 | ||
12438 | The @file{README} file in the @value{GDBN} distribution may list other | |
12439 | recently added stubs. | |
12440 | ||
12441 | @menu | |
12442 | * Stub Contents:: What the stub can do for you | |
12443 | * Bootstrapping:: What you must do for the stub | |
12444 | * Debug Session:: Putting it all together | |
104c1213 JM |
12445 | @end menu |
12446 | ||
6d2ebf8b | 12447 | @node Stub Contents |
6f05cf9f | 12448 | @subsection What the stub can do for you |
104c1213 JM |
12449 | |
12450 | @cindex remote serial stub | |
12451 | The debugging stub for your architecture supplies these three | |
12452 | subroutines: | |
12453 | ||
12454 | @table @code | |
12455 | @item set_debug_traps | |
4644b6e3 | 12456 | @findex set_debug_traps |
104c1213 JM |
12457 | @cindex remote serial stub, initialization |
12458 | This routine arranges for @code{handle_exception} to run when your | |
12459 | program stops. You must call this subroutine explicitly near the | |
12460 | beginning of your program. | |
12461 | ||
12462 | @item handle_exception | |
4644b6e3 | 12463 | @findex handle_exception |
104c1213 JM |
12464 | @cindex remote serial stub, main routine |
12465 | This is the central workhorse, but your program never calls it | |
12466 | explicitly---the setup code arranges for @code{handle_exception} to | |
12467 | run when a trap is triggered. | |
12468 | ||
12469 | @code{handle_exception} takes control when your program stops during | |
12470 | execution (for example, on a breakpoint), and mediates communications | |
12471 | with @value{GDBN} on the host machine. This is where the communications | |
12472 | protocol is implemented; @code{handle_exception} acts as the @value{GDBN} | |
d4f3574e | 12473 | representative on the target machine. It begins by sending summary |
104c1213 JM |
12474 | information on the state of your program, then continues to execute, |
12475 | retrieving and transmitting any information @value{GDBN} needs, until you | |
12476 | execute a @value{GDBN} command that makes your program resume; at that point, | |
12477 | @code{handle_exception} returns control to your own code on the target | |
5d161b24 | 12478 | machine. |
104c1213 JM |
12479 | |
12480 | @item breakpoint | |
12481 | @cindex @code{breakpoint} subroutine, remote | |
12482 | Use this auxiliary subroutine to make your program contain a | |
12483 | breakpoint. Depending on the particular situation, this may be the only | |
12484 | way for @value{GDBN} to get control. For instance, if your target | |
12485 | machine has some sort of interrupt button, you won't need to call this; | |
12486 | pressing the interrupt button transfers control to | |
12487 | @code{handle_exception}---in effect, to @value{GDBN}. On some machines, | |
12488 | simply receiving characters on the serial port may also trigger a trap; | |
12489 | again, in that situation, you don't need to call @code{breakpoint} from | |
12490 | your own program---simply running @samp{target remote} from the host | |
5d161b24 | 12491 | @value{GDBN} session gets control. |
104c1213 JM |
12492 | |
12493 | Call @code{breakpoint} if none of these is true, or if you simply want | |
12494 | to make certain your program stops at a predetermined point for the | |
12495 | start of your debugging session. | |
12496 | @end table | |
12497 | ||
6d2ebf8b | 12498 | @node Bootstrapping |
6f05cf9f | 12499 | @subsection What you must do for the stub |
104c1213 JM |
12500 | |
12501 | @cindex remote stub, support routines | |
12502 | The debugging stubs that come with @value{GDBN} are set up for a particular | |
12503 | chip architecture, but they have no information about the rest of your | |
12504 | debugging target machine. | |
12505 | ||
12506 | First of all you need to tell the stub how to communicate with the | |
12507 | serial port. | |
12508 | ||
12509 | @table @code | |
12510 | @item int getDebugChar() | |
4644b6e3 | 12511 | @findex getDebugChar |
104c1213 JM |
12512 | Write this subroutine to read a single character from the serial port. |
12513 | It may be identical to @code{getchar} for your target system; a | |
12514 | different name is used to allow you to distinguish the two if you wish. | |
12515 | ||
12516 | @item void putDebugChar(int) | |
4644b6e3 | 12517 | @findex putDebugChar |
104c1213 | 12518 | Write this subroutine to write a single character to the serial port. |
5d161b24 | 12519 | It may be identical to @code{putchar} for your target system; a |
104c1213 JM |
12520 | different name is used to allow you to distinguish the two if you wish. |
12521 | @end table | |
12522 | ||
12523 | @cindex control C, and remote debugging | |
12524 | @cindex interrupting remote targets | |
12525 | If you want @value{GDBN} to be able to stop your program while it is | |
12526 | running, you need to use an interrupt-driven serial driver, and arrange | |
12527 | for it to stop when it receives a @code{^C} (@samp{\003}, the control-C | |
12528 | character). That is the character which @value{GDBN} uses to tell the | |
12529 | remote system to stop. | |
12530 | ||
12531 | Getting the debugging target to return the proper status to @value{GDBN} | |
12532 | probably requires changes to the standard stub; one quick and dirty way | |
12533 | is to just execute a breakpoint instruction (the ``dirty'' part is that | |
12534 | @value{GDBN} reports a @code{SIGTRAP} instead of a @code{SIGINT}). | |
12535 | ||
12536 | Other routines you need to supply are: | |
12537 | ||
12538 | @table @code | |
12539 | @item void exceptionHandler (int @var{exception_number}, void *@var{exception_address}) | |
4644b6e3 | 12540 | @findex exceptionHandler |
104c1213 JM |
12541 | Write this function to install @var{exception_address} in the exception |
12542 | handling tables. You need to do this because the stub does not have any | |
12543 | way of knowing what the exception handling tables on your target system | |
12544 | are like (for example, the processor's table might be in @sc{rom}, | |
12545 | containing entries which point to a table in @sc{ram}). | |
12546 | @var{exception_number} is the exception number which should be changed; | |
12547 | its meaning is architecture-dependent (for example, different numbers | |
12548 | might represent divide by zero, misaligned access, etc). When this | |
12549 | exception occurs, control should be transferred directly to | |
12550 | @var{exception_address}, and the processor state (stack, registers, | |
12551 | and so on) should be just as it is when a processor exception occurs. So if | |
12552 | you want to use a jump instruction to reach @var{exception_address}, it | |
12553 | should be a simple jump, not a jump to subroutine. | |
12554 | ||
12555 | For the 386, @var{exception_address} should be installed as an interrupt | |
12556 | gate so that interrupts are masked while the handler runs. The gate | |
12557 | should be at privilege level 0 (the most privileged level). The | |
12558 | @sc{sparc} and 68k stubs are able to mask interrupts themselves without | |
12559 | help from @code{exceptionHandler}. | |
12560 | ||
12561 | @item void flush_i_cache() | |
4644b6e3 | 12562 | @findex flush_i_cache |
d4f3574e | 12563 | On @sc{sparc} and @sc{sparclite} only, write this subroutine to flush the |
104c1213 JM |
12564 | instruction cache, if any, on your target machine. If there is no |
12565 | instruction cache, this subroutine may be a no-op. | |
12566 | ||
12567 | On target machines that have instruction caches, @value{GDBN} requires this | |
12568 | function to make certain that the state of your program is stable. | |
12569 | @end table | |
12570 | ||
12571 | @noindent | |
12572 | You must also make sure this library routine is available: | |
12573 | ||
12574 | @table @code | |
12575 | @item void *memset(void *, int, int) | |
4644b6e3 | 12576 | @findex memset |
104c1213 JM |
12577 | This is the standard library function @code{memset} that sets an area of |
12578 | memory to a known value. If you have one of the free versions of | |
12579 | @code{libc.a}, @code{memset} can be found there; otherwise, you must | |
12580 | either obtain it from your hardware manufacturer, or write your own. | |
12581 | @end table | |
12582 | ||
12583 | If you do not use the GNU C compiler, you may need other standard | |
12584 | library subroutines as well; this varies from one stub to another, | |
12585 | but in general the stubs are likely to use any of the common library | |
d4f3574e | 12586 | subroutines which @code{@value{GCC}} generates as inline code. |
104c1213 JM |
12587 | |
12588 | ||
6d2ebf8b | 12589 | @node Debug Session |
6f05cf9f | 12590 | @subsection Putting it all together |
104c1213 JM |
12591 | |
12592 | @cindex remote serial debugging summary | |
12593 | In summary, when your program is ready to debug, you must follow these | |
12594 | steps. | |
12595 | ||
12596 | @enumerate | |
12597 | @item | |
6d2ebf8b | 12598 | Make sure you have defined the supporting low-level routines |
104c1213 JM |
12599 | (@pxref{Bootstrapping,,What you must do for the stub}): |
12600 | @display | |
12601 | @code{getDebugChar}, @code{putDebugChar}, | |
12602 | @code{flush_i_cache}, @code{memset}, @code{exceptionHandler}. | |
12603 | @end display | |
12604 | ||
12605 | @item | |
12606 | Insert these lines near the top of your program: | |
12607 | ||
474c8240 | 12608 | @smallexample |
104c1213 JM |
12609 | set_debug_traps(); |
12610 | breakpoint(); | |
474c8240 | 12611 | @end smallexample |
104c1213 JM |
12612 | |
12613 | @item | |
12614 | For the 680x0 stub only, you need to provide a variable called | |
12615 | @code{exceptionHook}. Normally you just use: | |
12616 | ||
474c8240 | 12617 | @smallexample |
104c1213 | 12618 | void (*exceptionHook)() = 0; |
474c8240 | 12619 | @end smallexample |
104c1213 | 12620 | |
d4f3574e | 12621 | @noindent |
104c1213 | 12622 | but if before calling @code{set_debug_traps}, you set it to point to a |
598ca718 | 12623 | function in your program, that function is called when |
104c1213 JM |
12624 | @code{@value{GDBN}} continues after stopping on a trap (for example, bus |
12625 | error). The function indicated by @code{exceptionHook} is called with | |
12626 | one parameter: an @code{int} which is the exception number. | |
12627 | ||
12628 | @item | |
12629 | Compile and link together: your program, the @value{GDBN} debugging stub for | |
12630 | your target architecture, and the supporting subroutines. | |
12631 | ||
12632 | @item | |
12633 | Make sure you have a serial connection between your target machine and | |
12634 | the @value{GDBN} host, and identify the serial port on the host. | |
12635 | ||
12636 | @item | |
12637 | @c The "remote" target now provides a `load' command, so we should | |
12638 | @c document that. FIXME. | |
12639 | Download your program to your target machine (or get it there by | |
12640 | whatever means the manufacturer provides), and start it. | |
12641 | ||
12642 | @item | |
07f31aa6 DJ |
12643 | Start @value{GDBN} on the host, and connect to the target |
12644 | (@pxref{Connecting,,Connecting to a remote target}). | |
9db8d71f | 12645 | |
104c1213 JM |
12646 | @end enumerate |
12647 | ||
8e04817f AC |
12648 | @node Configurations |
12649 | @chapter Configuration-Specific Information | |
104c1213 | 12650 | |
8e04817f AC |
12651 | While nearly all @value{GDBN} commands are available for all native and |
12652 | cross versions of the debugger, there are some exceptions. This chapter | |
12653 | describes things that are only available in certain configurations. | |
104c1213 | 12654 | |
8e04817f AC |
12655 | There are three major categories of configurations: native |
12656 | configurations, where the host and target are the same, embedded | |
12657 | operating system configurations, which are usually the same for several | |
12658 | different processor architectures, and bare embedded processors, which | |
12659 | are quite different from each other. | |
104c1213 | 12660 | |
8e04817f AC |
12661 | @menu |
12662 | * Native:: | |
12663 | * Embedded OS:: | |
12664 | * Embedded Processors:: | |
12665 | * Architectures:: | |
12666 | @end menu | |
104c1213 | 12667 | |
8e04817f AC |
12668 | @node Native |
12669 | @section Native | |
104c1213 | 12670 | |
8e04817f AC |
12671 | This section describes details specific to particular native |
12672 | configurations. | |
6cf7e474 | 12673 | |
8e04817f AC |
12674 | @menu |
12675 | * HP-UX:: HP-UX | |
7561d450 | 12676 | * BSD libkvm Interface:: Debugging BSD kernel memory images |
8e04817f AC |
12677 | * SVR4 Process Information:: SVR4 process information |
12678 | * DJGPP Native:: Features specific to the DJGPP port | |
78c47bea | 12679 | * Cygwin Native:: Features specific to the Cygwin port |
14d6dd68 | 12680 | * Hurd Native:: Features specific to @sc{gnu} Hurd |
a64548ea | 12681 | * Neutrino:: Features specific to QNX Neutrino |
8e04817f | 12682 | @end menu |
6cf7e474 | 12683 | |
8e04817f AC |
12684 | @node HP-UX |
12685 | @subsection HP-UX | |
104c1213 | 12686 | |
8e04817f AC |
12687 | On HP-UX systems, if you refer to a function or variable name that |
12688 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
12689 | name first, before it searches for a convenience variable. | |
104c1213 | 12690 | |
9c16f35a | 12691 | |
7561d450 MK |
12692 | @node BSD libkvm Interface |
12693 | @subsection BSD libkvm Interface | |
12694 | ||
12695 | @cindex libkvm | |
12696 | @cindex kernel memory image | |
12697 | @cindex kernel crash dump | |
12698 | ||
12699 | BSD-derived systems (FreeBSD/NetBSD/OpenBSD) have a kernel memory | |
12700 | interface that provides a uniform interface for accessing kernel virtual | |
12701 | memory images, including live systems and crash dumps. @value{GDBN} | |
12702 | uses this interface to allow you to debug live kernels and kernel crash | |
12703 | dumps on many native BSD configurations. This is implemented as a | |
12704 | special @code{kvm} debugging target. For debugging a live system, load | |
12705 | the currently running kernel into @value{GDBN} and connect to the | |
12706 | @code{kvm} target: | |
12707 | ||
12708 | @smallexample | |
12709 | (@value{GDBP}) @b{target kvm} | |
12710 | @end smallexample | |
12711 | ||
12712 | For debugging crash dumps, provide the file name of the crash dump as an | |
12713 | argument: | |
12714 | ||
12715 | @smallexample | |
12716 | (@value{GDBP}) @b{target kvm /var/crash/bsd.0} | |
12717 | @end smallexample | |
12718 | ||
12719 | Once connected to the @code{kvm} target, the following commands are | |
12720 | available: | |
12721 | ||
12722 | @table @code | |
12723 | @kindex kvm | |
12724 | @item kvm pcb | |
721c2651 | 12725 | Set current context from the @dfn{Process Control Block} (PCB) address. |
7561d450 MK |
12726 | |
12727 | @item kvm proc | |
12728 | Set current context from proc address. This command isn't available on | |
12729 | modern FreeBSD systems. | |
12730 | @end table | |
12731 | ||
8e04817f AC |
12732 | @node SVR4 Process Information |
12733 | @subsection SVR4 process information | |
60bf7e09 EZ |
12734 | @cindex /proc |
12735 | @cindex examine process image | |
12736 | @cindex process info via @file{/proc} | |
104c1213 | 12737 | |
60bf7e09 EZ |
12738 | Many versions of SVR4 and compatible systems provide a facility called |
12739 | @samp{/proc} that can be used to examine the image of a running | |
12740 | process using file-system subroutines. If @value{GDBN} is configured | |
12741 | for an operating system with this facility, the command @code{info | |
12742 | proc} is available to report information about the process running | |
12743 | your program, or about any process running on your system. @code{info | |
12744 | proc} works only on SVR4 systems that include the @code{procfs} code. | |
12745 | This includes, as of this writing, @sc{gnu}/Linux, OSF/1 (Digital | |
12746 | Unix), Solaris, Irix, and Unixware, but not HP-UX, for example. | |
104c1213 | 12747 | |
8e04817f AC |
12748 | @table @code |
12749 | @kindex info proc | |
60bf7e09 | 12750 | @cindex process ID |
8e04817f | 12751 | @item info proc |
60bf7e09 EZ |
12752 | @itemx info proc @var{process-id} |
12753 | Summarize available information about any running process. If a | |
12754 | process ID is specified by @var{process-id}, display information about | |
12755 | that process; otherwise display information about the program being | |
12756 | debugged. The summary includes the debugged process ID, the command | |
12757 | line used to invoke it, its current working directory, and its | |
12758 | executable file's absolute file name. | |
12759 | ||
12760 | On some systems, @var{process-id} can be of the form | |
12761 | @samp{[@var{pid}]/@var{tid}} which specifies a certain thread ID | |
12762 | within a process. If the optional @var{pid} part is missing, it means | |
12763 | a thread from the process being debugged (the leading @samp{/} still | |
12764 | needs to be present, or else @value{GDBN} will interpret the number as | |
12765 | a process ID rather than a thread ID). | |
6cf7e474 | 12766 | |
8e04817f | 12767 | @item info proc mappings |
60bf7e09 EZ |
12768 | @cindex memory address space mappings |
12769 | Report the memory address space ranges accessible in the program, with | |
12770 | information on whether the process has read, write, or execute access | |
12771 | rights to each range. On @sc{gnu}/Linux systems, each memory range | |
12772 | includes the object file which is mapped to that range, instead of the | |
12773 | memory access rights to that range. | |
12774 | ||
12775 | @item info proc stat | |
12776 | @itemx info proc status | |
12777 | @cindex process detailed status information | |
12778 | These subcommands are specific to @sc{gnu}/Linux systems. They show | |
12779 | the process-related information, including the user ID and group ID; | |
12780 | how many threads are there in the process; its virtual memory usage; | |
12781 | the signals that are pending, blocked, and ignored; its TTY; its | |
12782 | consumption of system and user time; its stack size; its @samp{nice} | |
2eecc4ab | 12783 | value; etc. For more information, see the @samp{proc} man page |
60bf7e09 EZ |
12784 | (type @kbd{man 5 proc} from your shell prompt). |
12785 | ||
12786 | @item info proc all | |
12787 | Show all the information about the process described under all of the | |
12788 | above @code{info proc} subcommands. | |
12789 | ||
8e04817f AC |
12790 | @ignore |
12791 | @comment These sub-options of 'info proc' were not included when | |
12792 | @comment procfs.c was re-written. Keep their descriptions around | |
12793 | @comment against the day when someone finds the time to put them back in. | |
12794 | @kindex info proc times | |
12795 | @item info proc times | |
12796 | Starting time, user CPU time, and system CPU time for your program and | |
12797 | its children. | |
6cf7e474 | 12798 | |
8e04817f AC |
12799 | @kindex info proc id |
12800 | @item info proc id | |
12801 | Report on the process IDs related to your program: its own process ID, | |
12802 | the ID of its parent, the process group ID, and the session ID. | |
8e04817f | 12803 | @end ignore |
721c2651 EZ |
12804 | |
12805 | @item set procfs-trace | |
12806 | @kindex set procfs-trace | |
12807 | @cindex @code{procfs} API calls | |
12808 | This command enables and disables tracing of @code{procfs} API calls. | |
12809 | ||
12810 | @item show procfs-trace | |
12811 | @kindex show procfs-trace | |
12812 | Show the current state of @code{procfs} API call tracing. | |
12813 | ||
12814 | @item set procfs-file @var{file} | |
12815 | @kindex set procfs-file | |
12816 | Tell @value{GDBN} to write @code{procfs} API trace to the named | |
12817 | @var{file}. @value{GDBN} appends the trace info to the previous | |
12818 | contents of the file. The default is to display the trace on the | |
12819 | standard output. | |
12820 | ||
12821 | @item show procfs-file | |
12822 | @kindex show procfs-file | |
12823 | Show the file to which @code{procfs} API trace is written. | |
12824 | ||
12825 | @item proc-trace-entry | |
12826 | @itemx proc-trace-exit | |
12827 | @itemx proc-untrace-entry | |
12828 | @itemx proc-untrace-exit | |
12829 | @kindex proc-trace-entry | |
12830 | @kindex proc-trace-exit | |
12831 | @kindex proc-untrace-entry | |
12832 | @kindex proc-untrace-exit | |
12833 | These commands enable and disable tracing of entries into and exits | |
12834 | from the @code{syscall} interface. | |
12835 | ||
12836 | @item info pidlist | |
12837 | @kindex info pidlist | |
12838 | @cindex process list, QNX Neutrino | |
12839 | For QNX Neutrino only, this command displays the list of all the | |
12840 | processes and all the threads within each process. | |
12841 | ||
12842 | @item info meminfo | |
12843 | @kindex info meminfo | |
12844 | @cindex mapinfo list, QNX Neutrino | |
12845 | For QNX Neutrino only, this command displays the list of all mapinfos. | |
8e04817f | 12846 | @end table |
104c1213 | 12847 | |
8e04817f AC |
12848 | @node DJGPP Native |
12849 | @subsection Features for Debugging @sc{djgpp} Programs | |
12850 | @cindex @sc{djgpp} debugging | |
12851 | @cindex native @sc{djgpp} debugging | |
12852 | @cindex MS-DOS-specific commands | |
104c1213 | 12853 | |
514c4d71 EZ |
12854 | @cindex DPMI |
12855 | @sc{djgpp} is a port of the @sc{gnu} development tools to MS-DOS and | |
8e04817f AC |
12856 | MS-Windows. @sc{djgpp} programs are 32-bit protected-mode programs |
12857 | that use the @dfn{DPMI} (DOS Protected-Mode Interface) API to run on | |
12858 | top of real-mode DOS systems and their emulations. | |
104c1213 | 12859 | |
8e04817f AC |
12860 | @value{GDBN} supports native debugging of @sc{djgpp} programs, and |
12861 | defines a few commands specific to the @sc{djgpp} port. This | |
12862 | subsection describes those commands. | |
104c1213 | 12863 | |
8e04817f AC |
12864 | @table @code |
12865 | @kindex info dos | |
12866 | @item info dos | |
12867 | This is a prefix of @sc{djgpp}-specific commands which print | |
12868 | information about the target system and important OS structures. | |
f1251bdd | 12869 | |
8e04817f AC |
12870 | @kindex sysinfo |
12871 | @cindex MS-DOS system info | |
12872 | @cindex free memory information (MS-DOS) | |
12873 | @item info dos sysinfo | |
12874 | This command displays assorted information about the underlying | |
12875 | platform: the CPU type and features, the OS version and flavor, the | |
12876 | DPMI version, and the available conventional and DPMI memory. | |
104c1213 | 12877 | |
8e04817f AC |
12878 | @cindex GDT |
12879 | @cindex LDT | |
12880 | @cindex IDT | |
12881 | @cindex segment descriptor tables | |
12882 | @cindex descriptor tables display | |
12883 | @item info dos gdt | |
12884 | @itemx info dos ldt | |
12885 | @itemx info dos idt | |
12886 | These 3 commands display entries from, respectively, Global, Local, | |
12887 | and Interrupt Descriptor Tables (GDT, LDT, and IDT). The descriptor | |
12888 | tables are data structures which store a descriptor for each segment | |
12889 | that is currently in use. The segment's selector is an index into a | |
12890 | descriptor table; the table entry for that index holds the | |
12891 | descriptor's base address and limit, and its attributes and access | |
12892 | rights. | |
104c1213 | 12893 | |
8e04817f AC |
12894 | A typical @sc{djgpp} program uses 3 segments: a code segment, a data |
12895 | segment (used for both data and the stack), and a DOS segment (which | |
12896 | allows access to DOS/BIOS data structures and absolute addresses in | |
12897 | conventional memory). However, the DPMI host will usually define | |
12898 | additional segments in order to support the DPMI environment. | |
d4f3574e | 12899 | |
8e04817f AC |
12900 | @cindex garbled pointers |
12901 | These commands allow to display entries from the descriptor tables. | |
12902 | Without an argument, all entries from the specified table are | |
12903 | displayed. An argument, which should be an integer expression, means | |
12904 | display a single entry whose index is given by the argument. For | |
12905 | example, here's a convenient way to display information about the | |
12906 | debugged program's data segment: | |
104c1213 | 12907 | |
8e04817f AC |
12908 | @smallexample |
12909 | @exdent @code{(@value{GDBP}) info dos ldt $ds} | |
12910 | @exdent @code{0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up)} | |
12911 | @end smallexample | |
104c1213 | 12912 | |
8e04817f AC |
12913 | @noindent |
12914 | This comes in handy when you want to see whether a pointer is outside | |
12915 | the data segment's limit (i.e.@: @dfn{garbled}). | |
104c1213 | 12916 | |
8e04817f AC |
12917 | @cindex page tables display (MS-DOS) |
12918 | @item info dos pde | |
12919 | @itemx info dos pte | |
12920 | These two commands display entries from, respectively, the Page | |
12921 | Directory and the Page Tables. Page Directories and Page Tables are | |
12922 | data structures which control how virtual memory addresses are mapped | |
12923 | into physical addresses. A Page Table includes an entry for every | |
12924 | page of memory that is mapped into the program's address space; there | |
12925 | may be several Page Tables, each one holding up to 4096 entries. A | |
12926 | Page Directory has up to 4096 entries, one each for every Page Table | |
12927 | that is currently in use. | |
104c1213 | 12928 | |
8e04817f AC |
12929 | Without an argument, @kbd{info dos pde} displays the entire Page |
12930 | Directory, and @kbd{info dos pte} displays all the entries in all of | |
12931 | the Page Tables. An argument, an integer expression, given to the | |
12932 | @kbd{info dos pde} command means display only that entry from the Page | |
12933 | Directory table. An argument given to the @kbd{info dos pte} command | |
12934 | means display entries from a single Page Table, the one pointed to by | |
12935 | the specified entry in the Page Directory. | |
104c1213 | 12936 | |
8e04817f AC |
12937 | @cindex direct memory access (DMA) on MS-DOS |
12938 | These commands are useful when your program uses @dfn{DMA} (Direct | |
12939 | Memory Access), which needs physical addresses to program the DMA | |
12940 | controller. | |
104c1213 | 12941 | |
8e04817f | 12942 | These commands are supported only with some DPMI servers. |
104c1213 | 12943 | |
8e04817f AC |
12944 | @cindex physical address from linear address |
12945 | @item info dos address-pte @var{addr} | |
12946 | This command displays the Page Table entry for a specified linear | |
514c4d71 EZ |
12947 | address. The argument @var{addr} is a linear address which should |
12948 | already have the appropriate segment's base address added to it, | |
12949 | because this command accepts addresses which may belong to @emph{any} | |
12950 | segment. For example, here's how to display the Page Table entry for | |
12951 | the page where a variable @code{i} is stored: | |
104c1213 | 12952 | |
b383017d | 12953 | @smallexample |
8e04817f AC |
12954 | @exdent @code{(@value{GDBP}) info dos address-pte __djgpp_base_address + (char *)&i} |
12955 | @exdent @code{Page Table entry for address 0x11a00d30:} | |
b383017d | 12956 | @exdent @code{Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30} |
8e04817f | 12957 | @end smallexample |
104c1213 | 12958 | |
8e04817f AC |
12959 | @noindent |
12960 | This says that @code{i} is stored at offset @code{0xd30} from the page | |
514c4d71 | 12961 | whose physical base address is @code{0x02698000}, and shows all the |
8e04817f | 12962 | attributes of that page. |
104c1213 | 12963 | |
8e04817f AC |
12964 | Note that you must cast the addresses of variables to a @code{char *}, |
12965 | since otherwise the value of @code{__djgpp_base_address}, the base | |
12966 | address of all variables and functions in a @sc{djgpp} program, will | |
12967 | be added using the rules of C pointer arithmetics: if @code{i} is | |
12968 | declared an @code{int}, @value{GDBN} will add 4 times the value of | |
12969 | @code{__djgpp_base_address} to the address of @code{i}. | |
104c1213 | 12970 | |
8e04817f AC |
12971 | Here's another example, it displays the Page Table entry for the |
12972 | transfer buffer: | |
104c1213 | 12973 | |
8e04817f AC |
12974 | @smallexample |
12975 | @exdent @code{(@value{GDBP}) info dos address-pte *((unsigned *)&_go32_info_block + 3)} | |
12976 | @exdent @code{Page Table entry for address 0x29110:} | |
12977 | @exdent @code{Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110} | |
12978 | @end smallexample | |
104c1213 | 12979 | |
8e04817f AC |
12980 | @noindent |
12981 | (The @code{+ 3} offset is because the transfer buffer's address is the | |
514c4d71 EZ |
12982 | 3rd member of the @code{_go32_info_block} structure.) The output |
12983 | clearly shows that this DPMI server maps the addresses in conventional | |
12984 | memory 1:1, i.e.@: the physical (@code{0x00029000} + @code{0x110}) and | |
12985 | linear (@code{0x29110}) addresses are identical. | |
104c1213 | 12986 | |
8e04817f AC |
12987 | This command is supported only with some DPMI servers. |
12988 | @end table | |
104c1213 | 12989 | |
c45da7e6 | 12990 | @cindex DOS serial data link, remote debugging |
a8f24a35 EZ |
12991 | In addition to native debugging, the DJGPP port supports remote |
12992 | debugging via a serial data link. The following commands are specific | |
12993 | to remote serial debugging in the DJGPP port of @value{GDBN}. | |
12994 | ||
12995 | @table @code | |
12996 | @kindex set com1base | |
12997 | @kindex set com1irq | |
12998 | @kindex set com2base | |
12999 | @kindex set com2irq | |
13000 | @kindex set com3base | |
13001 | @kindex set com3irq | |
13002 | @kindex set com4base | |
13003 | @kindex set com4irq | |
13004 | @item set com1base @var{addr} | |
13005 | This command sets the base I/O port address of the @file{COM1} serial | |
13006 | port. | |
13007 | ||
13008 | @item set com1irq @var{irq} | |
13009 | This command sets the @dfn{Interrupt Request} (@code{IRQ}) line to use | |
13010 | for the @file{COM1} serial port. | |
13011 | ||
13012 | There are similar commands @samp{set com2base}, @samp{set com3irq}, | |
13013 | etc.@: for setting the port address and the @code{IRQ} lines for the | |
13014 | other 3 COM ports. | |
13015 | ||
13016 | @kindex show com1base | |
13017 | @kindex show com1irq | |
13018 | @kindex show com2base | |
13019 | @kindex show com2irq | |
13020 | @kindex show com3base | |
13021 | @kindex show com3irq | |
13022 | @kindex show com4base | |
13023 | @kindex show com4irq | |
13024 | The related commands @samp{show com1base}, @samp{show com1irq} etc.@: | |
13025 | display the current settings of the base address and the @code{IRQ} | |
13026 | lines used by the COM ports. | |
c45da7e6 EZ |
13027 | |
13028 | @item info serial | |
13029 | @kindex info serial | |
13030 | @cindex DOS serial port status | |
13031 | This command prints the status of the 4 DOS serial ports. For each | |
13032 | port, it prints whether it's active or not, its I/O base address and | |
13033 | IRQ number, whether it uses a 16550-style FIFO, its baudrate, and the | |
13034 | counts of various errors encountered so far. | |
a8f24a35 EZ |
13035 | @end table |
13036 | ||
13037 | ||
78c47bea PM |
13038 | @node Cygwin Native |
13039 | @subsection Features for Debugging MS Windows PE executables | |
13040 | @cindex MS Windows debugging | |
13041 | @cindex native Cygwin debugging | |
13042 | @cindex Cygwin-specific commands | |
13043 | ||
be448670 CF |
13044 | @value{GDBN} supports native debugging of MS Windows programs, including |
13045 | DLLs with and without symbolic debugging information. There are various | |
13046 | additional Cygwin-specific commands, described in this subsection. The | |
13047 | subsubsection @pxref{Non-debug DLL symbols} describes working with DLLs | |
13048 | that have no debugging symbols. | |
13049 | ||
78c47bea PM |
13050 | |
13051 | @table @code | |
13052 | @kindex info w32 | |
13053 | @item info w32 | |
13054 | This is a prefix of MS Windows specific commands which print | |
13055 | information about the target system and important OS structures. | |
13056 | ||
13057 | @item info w32 selector | |
13058 | This command displays information returned by | |
13059 | the Win32 API @code{GetThreadSelectorEntry} function. | |
13060 | It takes an optional argument that is evaluated to | |
13061 | a long value to give the information about this given selector. | |
13062 | Without argument, this command displays information | |
13063 | about the the six segment registers. | |
13064 | ||
13065 | @kindex info dll | |
13066 | @item info dll | |
13067 | This is a Cygwin specific alias of info shared. | |
13068 | ||
13069 | @kindex dll-symbols | |
13070 | @item dll-symbols | |
13071 | This command loads symbols from a dll similarly to | |
13072 | add-sym command but without the need to specify a base address. | |
13073 | ||
b383017d | 13074 | @kindex set new-console |
78c47bea | 13075 | @item set new-console @var{mode} |
b383017d | 13076 | If @var{mode} is @code{on} the debuggee will |
78c47bea PM |
13077 | be started in a new console on next start. |
13078 | If @var{mode} is @code{off}i, the debuggee will | |
13079 | be started in the same console as the debugger. | |
13080 | ||
13081 | @kindex show new-console | |
13082 | @item show new-console | |
13083 | Displays whether a new console is used | |
13084 | when the debuggee is started. | |
13085 | ||
13086 | @kindex set new-group | |
13087 | @item set new-group @var{mode} | |
13088 | This boolean value controls whether the debuggee should | |
13089 | start a new group or stay in the same group as the debugger. | |
13090 | This affects the way the Windows OS handles | |
13091 | Ctrl-C. | |
13092 | ||
13093 | @kindex show new-group | |
13094 | @item show new-group | |
13095 | Displays current value of new-group boolean. | |
13096 | ||
13097 | @kindex set debugevents | |
13098 | @item set debugevents | |
13099 | This boolean value adds debug output concerning events seen by the debugger. | |
13100 | ||
13101 | @kindex set debugexec | |
13102 | @item set debugexec | |
b383017d | 13103 | This boolean value adds debug output concerning execute events |
78c47bea PM |
13104 | seen by the debugger. |
13105 | ||
13106 | @kindex set debugexceptions | |
13107 | @item set debugexceptions | |
b383017d | 13108 | This boolean value adds debug ouptut concerning exception events |
78c47bea PM |
13109 | seen by the debugger. |
13110 | ||
13111 | @kindex set debugmemory | |
13112 | @item set debugmemory | |
b383017d | 13113 | This boolean value adds debug ouptut concerning memory events |
78c47bea PM |
13114 | seen by the debugger. |
13115 | ||
13116 | @kindex set shell | |
13117 | @item set shell | |
13118 | This boolean values specifies whether the debuggee is called | |
13119 | via a shell or directly (default value is on). | |
13120 | ||
13121 | @kindex show shell | |
13122 | @item show shell | |
13123 | Displays if the debuggee will be started with a shell. | |
13124 | ||
13125 | @end table | |
13126 | ||
be448670 CF |
13127 | @menu |
13128 | * Non-debug DLL symbols:: Support for DLLs without debugging symbols | |
13129 | @end menu | |
13130 | ||
13131 | @node Non-debug DLL symbols | |
13132 | @subsubsection Support for DLLs without debugging symbols | |
13133 | @cindex DLLs with no debugging symbols | |
13134 | @cindex Minimal symbols and DLLs | |
13135 | ||
13136 | Very often on windows, some of the DLLs that your program relies on do | |
13137 | not include symbolic debugging information (for example, | |
13138 | @file{kernel32.dll}). When @value{GDBN} doesn't recognize any debugging | |
13139 | symbols in a DLL, it relies on the minimal amount of symbolic | |
13140 | information contained in the DLL's export table. This subsubsection | |
13141 | describes working with such symbols, known internally to @value{GDBN} as | |
13142 | ``minimal symbols''. | |
13143 | ||
13144 | Note that before the debugged program has started execution, no DLLs | |
13145 | will have been loaded. The easiest way around this problem is simply to | |
13146 | start the program --- either by setting a breakpoint or letting the | |
13147 | program run once to completion. It is also possible to force | |
13148 | @value{GDBN} to load a particular DLL before starting the executable --- | |
13149 | see the shared library information in @pxref{Files} or the | |
13150 | @code{dll-symbols} command in @pxref{Cygwin Native}. Currently, | |
13151 | explicitly loading symbols from a DLL with no debugging information will | |
13152 | cause the symbol names to be duplicated in @value{GDBN}'s lookup table, | |
13153 | which may adversely affect symbol lookup performance. | |
13154 | ||
13155 | @subsubsection DLL name prefixes | |
13156 | ||
13157 | In keeping with the naming conventions used by the Microsoft debugging | |
13158 | tools, DLL export symbols are made available with a prefix based on the | |
13159 | DLL name, for instance @code{KERNEL32!CreateFileA}. The plain name is | |
13160 | also entered into the symbol table, so @code{CreateFileA} is often | |
13161 | sufficient. In some cases there will be name clashes within a program | |
13162 | (particularly if the executable itself includes full debugging symbols) | |
13163 | necessitating the use of the fully qualified name when referring to the | |
13164 | contents of the DLL. Use single-quotes around the name to avoid the | |
13165 | exclamation mark (``!'') being interpreted as a language operator. | |
13166 | ||
13167 | Note that the internal name of the DLL may be all upper-case, even | |
13168 | though the file name of the DLL is lower-case, or vice-versa. Since | |
13169 | symbols within @value{GDBN} are @emph{case-sensitive} this may cause | |
13170 | some confusion. If in doubt, try the @code{info functions} and | |
13171 | @code{info variables} commands or even @code{maint print msymbols} (see | |
13172 | @pxref{Symbols}). Here's an example: | |
13173 | ||
13174 | @smallexample | |
f7dc1244 | 13175 | (@value{GDBP}) info function CreateFileA |
be448670 CF |
13176 | All functions matching regular expression "CreateFileA": |
13177 | ||
13178 | Non-debugging symbols: | |
13179 | 0x77e885f4 CreateFileA | |
13180 | 0x77e885f4 KERNEL32!CreateFileA | |
13181 | @end smallexample | |
13182 | ||
13183 | @smallexample | |
f7dc1244 | 13184 | (@value{GDBP}) info function ! |
be448670 CF |
13185 | All functions matching regular expression "!": |
13186 | ||
13187 | Non-debugging symbols: | |
13188 | 0x6100114c cygwin1!__assert | |
13189 | 0x61004034 cygwin1!_dll_crt0@@0 | |
13190 | 0x61004240 cygwin1!dll_crt0(per_process *) | |
13191 | [etc...] | |
13192 | @end smallexample | |
13193 | ||
13194 | @subsubsection Working with minimal symbols | |
13195 | ||
13196 | Symbols extracted from a DLL's export table do not contain very much | |
13197 | type information. All that @value{GDBN} can do is guess whether a symbol | |
13198 | refers to a function or variable depending on the linker section that | |
13199 | contains the symbol. Also note that the actual contents of the memory | |
13200 | contained in a DLL are not available unless the program is running. This | |
13201 | means that you cannot examine the contents of a variable or disassemble | |
13202 | a function within a DLL without a running program. | |
13203 | ||
13204 | Variables are generally treated as pointers and dereferenced | |
13205 | automatically. For this reason, it is often necessary to prefix a | |
13206 | variable name with the address-of operator (``&'') and provide explicit | |
13207 | type information in the command. Here's an example of the type of | |
13208 | problem: | |
13209 | ||
13210 | @smallexample | |
f7dc1244 | 13211 | (@value{GDBP}) print 'cygwin1!__argv' |
be448670 CF |
13212 | $1 = 268572168 |
13213 | @end smallexample | |
13214 | ||
13215 | @smallexample | |
f7dc1244 | 13216 | (@value{GDBP}) x 'cygwin1!__argv' |
be448670 CF |
13217 | 0x10021610: "\230y\"" |
13218 | @end smallexample | |
13219 | ||
13220 | And two possible solutions: | |
13221 | ||
13222 | @smallexample | |
f7dc1244 | 13223 | (@value{GDBP}) print ((char **)'cygwin1!__argv')[0] |
be448670 CF |
13224 | $2 = 0x22fd98 "/cygdrive/c/mydirectory/myprogram" |
13225 | @end smallexample | |
13226 | ||
13227 | @smallexample | |
f7dc1244 | 13228 | (@value{GDBP}) x/2x &'cygwin1!__argv' |
be448670 | 13229 | 0x610c0aa8 <cygwin1!__argv>: 0x10021608 0x00000000 |
f7dc1244 | 13230 | (@value{GDBP}) x/x 0x10021608 |
be448670 | 13231 | 0x10021608: 0x0022fd98 |
f7dc1244 | 13232 | (@value{GDBP}) x/s 0x0022fd98 |
be448670 CF |
13233 | 0x22fd98: "/cygdrive/c/mydirectory/myprogram" |
13234 | @end smallexample | |
13235 | ||
13236 | Setting a break point within a DLL is possible even before the program | |
13237 | starts execution. However, under these circumstances, @value{GDBN} can't | |
13238 | examine the initial instructions of the function in order to skip the | |
13239 | function's frame set-up code. You can work around this by using ``*&'' | |
13240 | to set the breakpoint at a raw memory address: | |
13241 | ||
13242 | @smallexample | |
f7dc1244 | 13243 | (@value{GDBP}) break *&'python22!PyOS_Readline' |
be448670 CF |
13244 | Breakpoint 1 at 0x1e04eff0 |
13245 | @end smallexample | |
13246 | ||
13247 | The author of these extensions is not entirely convinced that setting a | |
13248 | break point within a shared DLL like @file{kernel32.dll} is completely | |
13249 | safe. | |
13250 | ||
14d6dd68 EZ |
13251 | @node Hurd Native |
13252 | @subsection Commands specific to @sc{gnu} Hurd systems | |
13253 | @cindex @sc{gnu} Hurd debugging | |
13254 | ||
13255 | This subsection describes @value{GDBN} commands specific to the | |
13256 | @sc{gnu} Hurd native debugging. | |
13257 | ||
13258 | @table @code | |
13259 | @item set signals | |
13260 | @itemx set sigs | |
13261 | @kindex set signals@r{, Hurd command} | |
13262 | @kindex set sigs@r{, Hurd command} | |
13263 | This command toggles the state of inferior signal interception by | |
13264 | @value{GDBN}. Mach exceptions, such as breakpoint traps, are not | |
13265 | affected by this command. @code{sigs} is a shorthand alias for | |
13266 | @code{signals}. | |
13267 | ||
13268 | @item show signals | |
13269 | @itemx show sigs | |
13270 | @kindex show signals@r{, Hurd command} | |
13271 | @kindex show sigs@r{, Hurd command} | |
13272 | Show the current state of intercepting inferior's signals. | |
13273 | ||
13274 | @item set signal-thread | |
13275 | @itemx set sigthread | |
13276 | @kindex set signal-thread | |
13277 | @kindex set sigthread | |
13278 | This command tells @value{GDBN} which thread is the @code{libc} signal | |
13279 | thread. That thread is run when a signal is delivered to a running | |
13280 | process. @code{set sigthread} is the shorthand alias of @code{set | |
13281 | signal-thread}. | |
13282 | ||
13283 | @item show signal-thread | |
13284 | @itemx show sigthread | |
13285 | @kindex show signal-thread | |
13286 | @kindex show sigthread | |
13287 | These two commands show which thread will run when the inferior is | |
13288 | delivered a signal. | |
13289 | ||
13290 | @item set stopped | |
13291 | @kindex set stopped@r{, Hurd command} | |
13292 | This commands tells @value{GDBN} that the inferior process is stopped, | |
13293 | as with the @code{SIGSTOP} signal. The stopped process can be | |
13294 | continued by delivering a signal to it. | |
13295 | ||
13296 | @item show stopped | |
13297 | @kindex show stopped@r{, Hurd command} | |
13298 | This command shows whether @value{GDBN} thinks the debuggee is | |
13299 | stopped. | |
13300 | ||
13301 | @item set exceptions | |
13302 | @kindex set exceptions@r{, Hurd command} | |
13303 | Use this command to turn off trapping of exceptions in the inferior. | |
13304 | When exception trapping is off, neither breakpoints nor | |
13305 | single-stepping will work. To restore the default, set exception | |
13306 | trapping on. | |
13307 | ||
13308 | @item show exceptions | |
13309 | @kindex show exceptions@r{, Hurd command} | |
13310 | Show the current state of trapping exceptions in the inferior. | |
13311 | ||
13312 | @item set task pause | |
13313 | @kindex set task@r{, Hurd commands} | |
13314 | @cindex task attributes (@sc{gnu} Hurd) | |
13315 | @cindex pause current task (@sc{gnu} Hurd) | |
13316 | This command toggles task suspension when @value{GDBN} has control. | |
13317 | Setting it to on takes effect immediately, and the task is suspended | |
13318 | whenever @value{GDBN} gets control. Setting it to off will take | |
13319 | effect the next time the inferior is continued. If this option is set | |
13320 | to off, you can use @code{set thread default pause on} or @code{set | |
13321 | thread pause on} (see below) to pause individual threads. | |
13322 | ||
13323 | @item show task pause | |
13324 | @kindex show task@r{, Hurd commands} | |
13325 | Show the current state of task suspension. | |
13326 | ||
13327 | @item set task detach-suspend-count | |
13328 | @cindex task suspend count | |
13329 | @cindex detach from task, @sc{gnu} Hurd | |
13330 | This command sets the suspend count the task will be left with when | |
13331 | @value{GDBN} detaches from it. | |
13332 | ||
13333 | @item show task detach-suspend-count | |
13334 | Show the suspend count the task will be left with when detaching. | |
13335 | ||
13336 | @item set task exception-port | |
13337 | @itemx set task excp | |
13338 | @cindex task exception port, @sc{gnu} Hurd | |
13339 | This command sets the task exception port to which @value{GDBN} will | |
13340 | forward exceptions. The argument should be the value of the @dfn{send | |
13341 | rights} of the task. @code{set task excp} is a shorthand alias. | |
13342 | ||
13343 | @item set noninvasive | |
13344 | @cindex noninvasive task options | |
13345 | This command switches @value{GDBN} to a mode that is the least | |
13346 | invasive as far as interfering with the inferior is concerned. This | |
13347 | is the same as using @code{set task pause}, @code{set exceptions}, and | |
13348 | @code{set signals} to values opposite to the defaults. | |
13349 | ||
13350 | @item info send-rights | |
13351 | @itemx info receive-rights | |
13352 | @itemx info port-rights | |
13353 | @itemx info port-sets | |
13354 | @itemx info dead-names | |
13355 | @itemx info ports | |
13356 | @itemx info psets | |
13357 | @cindex send rights, @sc{gnu} Hurd | |
13358 | @cindex receive rights, @sc{gnu} Hurd | |
13359 | @cindex port rights, @sc{gnu} Hurd | |
13360 | @cindex port sets, @sc{gnu} Hurd | |
13361 | @cindex dead names, @sc{gnu} Hurd | |
13362 | These commands display information about, respectively, send rights, | |
13363 | receive rights, port rights, port sets, and dead names of a task. | |
13364 | There are also shorthand aliases: @code{info ports} for @code{info | |
13365 | port-rights} and @code{info psets} for @code{info port-sets}. | |
13366 | ||
13367 | @item set thread pause | |
13368 | @kindex set thread@r{, Hurd command} | |
13369 | @cindex thread properties, @sc{gnu} Hurd | |
13370 | @cindex pause current thread (@sc{gnu} Hurd) | |
13371 | This command toggles current thread suspension when @value{GDBN} has | |
13372 | control. Setting it to on takes effect immediately, and the current | |
13373 | thread is suspended whenever @value{GDBN} gets control. Setting it to | |
13374 | off will take effect the next time the inferior is continued. | |
13375 | Normally, this command has no effect, since when @value{GDBN} has | |
13376 | control, the whole task is suspended. However, if you used @code{set | |
13377 | task pause off} (see above), this command comes in handy to suspend | |
13378 | only the current thread. | |
13379 | ||
13380 | @item show thread pause | |
13381 | @kindex show thread@r{, Hurd command} | |
13382 | This command shows the state of current thread suspension. | |
13383 | ||
13384 | @item set thread run | |
13385 | This comamnd sets whether the current thread is allowed to run. | |
13386 | ||
13387 | @item show thread run | |
13388 | Show whether the current thread is allowed to run. | |
13389 | ||
13390 | @item set thread detach-suspend-count | |
13391 | @cindex thread suspend count, @sc{gnu} Hurd | |
13392 | @cindex detach from thread, @sc{gnu} Hurd | |
13393 | This command sets the suspend count @value{GDBN} will leave on a | |
13394 | thread when detaching. This number is relative to the suspend count | |
13395 | found by @value{GDBN} when it notices the thread; use @code{set thread | |
13396 | takeover-suspend-count} to force it to an absolute value. | |
13397 | ||
13398 | @item show thread detach-suspend-count | |
13399 | Show the suspend count @value{GDBN} will leave on the thread when | |
13400 | detaching. | |
13401 | ||
13402 | @item set thread exception-port | |
13403 | @itemx set thread excp | |
13404 | Set the thread exception port to which to forward exceptions. This | |
13405 | overrides the port set by @code{set task exception-port} (see above). | |
13406 | @code{set thread excp} is the shorthand alias. | |
13407 | ||
13408 | @item set thread takeover-suspend-count | |
13409 | Normally, @value{GDBN}'s thread suspend counts are relative to the | |
13410 | value @value{GDBN} finds when it notices each thread. This command | |
13411 | changes the suspend counts to be absolute instead. | |
13412 | ||
13413 | @item set thread default | |
13414 | @itemx show thread default | |
13415 | @cindex thread default settings, @sc{gnu} Hurd | |
13416 | Each of the above @code{set thread} commands has a @code{set thread | |
13417 | default} counterpart (e.g., @code{set thread default pause}, @code{set | |
13418 | thread default exception-port}, etc.). The @code{thread default} | |
13419 | variety of commands sets the default thread properties for all | |
13420 | threads; you can then change the properties of individual threads with | |
13421 | the non-default commands. | |
13422 | @end table | |
13423 | ||
13424 | ||
a64548ea EZ |
13425 | @node Neutrino |
13426 | @subsection QNX Neutrino | |
13427 | @cindex QNX Neutrino | |
13428 | ||
13429 | @value{GDBN} provides the following commands specific to the QNX | |
13430 | Neutrino target: | |
13431 | ||
13432 | @table @code | |
13433 | @item set debug nto-debug | |
13434 | @kindex set debug nto-debug | |
13435 | When set to on, enables debugging messages specific to the QNX | |
13436 | Neutrino support. | |
13437 | ||
13438 | @item show debug nto-debug | |
13439 | @kindex show debug nto-debug | |
13440 | Show the current state of QNX Neutrino messages. | |
13441 | @end table | |
13442 | ||
13443 | ||
8e04817f AC |
13444 | @node Embedded OS |
13445 | @section Embedded Operating Systems | |
104c1213 | 13446 | |
8e04817f AC |
13447 | This section describes configurations involving the debugging of |
13448 | embedded operating systems that are available for several different | |
13449 | architectures. | |
d4f3574e | 13450 | |
8e04817f AC |
13451 | @menu |
13452 | * VxWorks:: Using @value{GDBN} with VxWorks | |
13453 | @end menu | |
104c1213 | 13454 | |
8e04817f AC |
13455 | @value{GDBN} includes the ability to debug programs running on |
13456 | various real-time operating systems. | |
104c1213 | 13457 | |
8e04817f AC |
13458 | @node VxWorks |
13459 | @subsection Using @value{GDBN} with VxWorks | |
104c1213 | 13460 | |
8e04817f | 13461 | @cindex VxWorks |
104c1213 | 13462 | |
8e04817f | 13463 | @table @code |
104c1213 | 13464 | |
8e04817f AC |
13465 | @kindex target vxworks |
13466 | @item target vxworks @var{machinename} | |
13467 | A VxWorks system, attached via TCP/IP. The argument @var{machinename} | |
13468 | is the target system's machine name or IP address. | |
104c1213 | 13469 | |
8e04817f | 13470 | @end table |
104c1213 | 13471 | |
8e04817f AC |
13472 | On VxWorks, @code{load} links @var{filename} dynamically on the |
13473 | current target system as well as adding its symbols in @value{GDBN}. | |
104c1213 | 13474 | |
8e04817f AC |
13475 | @value{GDBN} enables developers to spawn and debug tasks running on networked |
13476 | VxWorks targets from a Unix host. Already-running tasks spawned from | |
13477 | the VxWorks shell can also be debugged. @value{GDBN} uses code that runs on | |
13478 | both the Unix host and on the VxWorks target. The program | |
13479 | @code{@value{GDBP}} is installed and executed on the Unix host. (It may be | |
13480 | installed with the name @code{vxgdb}, to distinguish it from a | |
13481 | @value{GDBN} for debugging programs on the host itself.) | |
104c1213 | 13482 | |
8e04817f AC |
13483 | @table @code |
13484 | @item VxWorks-timeout @var{args} | |
13485 | @kindex vxworks-timeout | |
13486 | All VxWorks-based targets now support the option @code{vxworks-timeout}. | |
13487 | This option is set by the user, and @var{args} represents the number of | |
13488 | seconds @value{GDBN} waits for responses to rpc's. You might use this if | |
13489 | your VxWorks target is a slow software simulator or is on the far side | |
13490 | of a thin network line. | |
13491 | @end table | |
104c1213 | 13492 | |
8e04817f AC |
13493 | The following information on connecting to VxWorks was current when |
13494 | this manual was produced; newer releases of VxWorks may use revised | |
13495 | procedures. | |
104c1213 | 13496 | |
4644b6e3 | 13497 | @findex INCLUDE_RDB |
8e04817f AC |
13498 | To use @value{GDBN} with VxWorks, you must rebuild your VxWorks kernel |
13499 | to include the remote debugging interface routines in the VxWorks | |
13500 | library @file{rdb.a}. To do this, define @code{INCLUDE_RDB} in the | |
13501 | VxWorks configuration file @file{configAll.h} and rebuild your VxWorks | |
13502 | kernel. The resulting kernel contains @file{rdb.a}, and spawns the | |
13503 | source debugging task @code{tRdbTask} when VxWorks is booted. For more | |
13504 | information on configuring and remaking VxWorks, see the manufacturer's | |
13505 | manual. | |
13506 | @c VxWorks, see the @cite{VxWorks Programmer's Guide}. | |
104c1213 | 13507 | |
8e04817f AC |
13508 | Once you have included @file{rdb.a} in your VxWorks system image and set |
13509 | your Unix execution search path to find @value{GDBN}, you are ready to | |
13510 | run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} (or | |
13511 | @code{vxgdb}, depending on your installation). | |
104c1213 | 13512 | |
8e04817f | 13513 | @value{GDBN} comes up showing the prompt: |
104c1213 | 13514 | |
474c8240 | 13515 | @smallexample |
8e04817f | 13516 | (vxgdb) |
474c8240 | 13517 | @end smallexample |
104c1213 | 13518 | |
8e04817f AC |
13519 | @menu |
13520 | * VxWorks Connection:: Connecting to VxWorks | |
13521 | * VxWorks Download:: VxWorks download | |
13522 | * VxWorks Attach:: Running tasks | |
13523 | @end menu | |
104c1213 | 13524 | |
8e04817f AC |
13525 | @node VxWorks Connection |
13526 | @subsubsection Connecting to VxWorks | |
104c1213 | 13527 | |
8e04817f AC |
13528 | The @value{GDBN} command @code{target} lets you connect to a VxWorks target on the |
13529 | network. To connect to a target whose host name is ``@code{tt}'', type: | |
104c1213 | 13530 | |
474c8240 | 13531 | @smallexample |
8e04817f | 13532 | (vxgdb) target vxworks tt |
474c8240 | 13533 | @end smallexample |
104c1213 | 13534 | |
8e04817f AC |
13535 | @need 750 |
13536 | @value{GDBN} displays messages like these: | |
104c1213 | 13537 | |
8e04817f AC |
13538 | @smallexample |
13539 | Attaching remote machine across net... | |
13540 | Connected to tt. | |
13541 | @end smallexample | |
104c1213 | 13542 | |
8e04817f AC |
13543 | @need 1000 |
13544 | @value{GDBN} then attempts to read the symbol tables of any object modules | |
13545 | loaded into the VxWorks target since it was last booted. @value{GDBN} locates | |
13546 | these files by searching the directories listed in the command search | |
13547 | path (@pxref{Environment, ,Your program's environment}); if it fails | |
13548 | to find an object file, it displays a message such as: | |
5d161b24 | 13549 | |
474c8240 | 13550 | @smallexample |
8e04817f | 13551 | prog.o: No such file or directory. |
474c8240 | 13552 | @end smallexample |
104c1213 | 13553 | |
8e04817f AC |
13554 | When this happens, add the appropriate directory to the search path with |
13555 | the @value{GDBN} command @code{path}, and execute the @code{target} | |
13556 | command again. | |
104c1213 | 13557 | |
8e04817f AC |
13558 | @node VxWorks Download |
13559 | @subsubsection VxWorks download | |
104c1213 | 13560 | |
8e04817f AC |
13561 | @cindex download to VxWorks |
13562 | If you have connected to the VxWorks target and you want to debug an | |
13563 | object that has not yet been loaded, you can use the @value{GDBN} | |
13564 | @code{load} command to download a file from Unix to VxWorks | |
13565 | incrementally. The object file given as an argument to the @code{load} | |
13566 | command is actually opened twice: first by the VxWorks target in order | |
13567 | to download the code, then by @value{GDBN} in order to read the symbol | |
13568 | table. This can lead to problems if the current working directories on | |
13569 | the two systems differ. If both systems have NFS mounted the same | |
13570 | filesystems, you can avoid these problems by using absolute paths. | |
13571 | Otherwise, it is simplest to set the working directory on both systems | |
13572 | to the directory in which the object file resides, and then to reference | |
13573 | the file by its name, without any path. For instance, a program | |
13574 | @file{prog.o} may reside in @file{@var{vxpath}/vw/demo/rdb} in VxWorks | |
13575 | and in @file{@var{hostpath}/vw/demo/rdb} on the host. To load this | |
13576 | program, type this on VxWorks: | |
104c1213 | 13577 | |
474c8240 | 13578 | @smallexample |
8e04817f | 13579 | -> cd "@var{vxpath}/vw/demo/rdb" |
474c8240 | 13580 | @end smallexample |
104c1213 | 13581 | |
8e04817f AC |
13582 | @noindent |
13583 | Then, in @value{GDBN}, type: | |
104c1213 | 13584 | |
474c8240 | 13585 | @smallexample |
8e04817f AC |
13586 | (vxgdb) cd @var{hostpath}/vw/demo/rdb |
13587 | (vxgdb) load prog.o | |
474c8240 | 13588 | @end smallexample |
104c1213 | 13589 | |
8e04817f | 13590 | @value{GDBN} displays a response similar to this: |
104c1213 | 13591 | |
8e04817f AC |
13592 | @smallexample |
13593 | Reading symbol data from wherever/vw/demo/rdb/prog.o... done. | |
13594 | @end smallexample | |
104c1213 | 13595 | |
8e04817f AC |
13596 | You can also use the @code{load} command to reload an object module |
13597 | after editing and recompiling the corresponding source file. Note that | |
13598 | this makes @value{GDBN} delete all currently-defined breakpoints, | |
13599 | auto-displays, and convenience variables, and to clear the value | |
13600 | history. (This is necessary in order to preserve the integrity of | |
13601 | debugger's data structures that reference the target system's symbol | |
13602 | table.) | |
104c1213 | 13603 | |
8e04817f AC |
13604 | @node VxWorks Attach |
13605 | @subsubsection Running tasks | |
104c1213 JM |
13606 | |
13607 | @cindex running VxWorks tasks | |
13608 | You can also attach to an existing task using the @code{attach} command as | |
13609 | follows: | |
13610 | ||
474c8240 | 13611 | @smallexample |
104c1213 | 13612 | (vxgdb) attach @var{task} |
474c8240 | 13613 | @end smallexample |
104c1213 JM |
13614 | |
13615 | @noindent | |
13616 | where @var{task} is the VxWorks hexadecimal task ID. The task can be running | |
13617 | or suspended when you attach to it. Running tasks are suspended at | |
13618 | the time of attachment. | |
13619 | ||
6d2ebf8b | 13620 | @node Embedded Processors |
104c1213 JM |
13621 | @section Embedded Processors |
13622 | ||
13623 | This section goes into details specific to particular embedded | |
13624 | configurations. | |
13625 | ||
c45da7e6 EZ |
13626 | @cindex send command to simulator |
13627 | Whenever a specific embedded processor has a simulator, @value{GDBN} | |
13628 | allows to send an arbitrary command to the simulator. | |
13629 | ||
13630 | @table @code | |
13631 | @item sim @var{command} | |
13632 | @kindex sim@r{, a command} | |
13633 | Send an arbitrary @var{command} string to the simulator. Consult the | |
13634 | documentation for the specific simulator in use for information about | |
13635 | acceptable commands. | |
13636 | @end table | |
13637 | ||
7d86b5d5 | 13638 | |
104c1213 | 13639 | @menu |
c45da7e6 | 13640 | * ARM:: ARM RDI |
172c2a43 KI |
13641 | * H8/300:: Renesas H8/300 |
13642 | * H8/500:: Renesas H8/500 | |
13643 | * M32R/D:: Renesas M32R/D | |
104c1213 | 13644 | * M68K:: Motorola M68K |
104c1213 | 13645 | * MIPS Embedded:: MIPS Embedded |
a37295f9 | 13646 | * OpenRISC 1000:: OpenRisc 1000 |
104c1213 JM |
13647 | * PA:: HP PA Embedded |
13648 | * PowerPC: PowerPC | |
172c2a43 | 13649 | * SH:: Renesas SH |
104c1213 JM |
13650 | * Sparclet:: Tsqware Sparclet |
13651 | * Sparclite:: Fujitsu Sparclite | |
13652 | * ST2000:: Tandem ST2000 | |
13653 | * Z8000:: Zilog Z8000 | |
a64548ea EZ |
13654 | * AVR:: Atmel AVR |
13655 | * CRIS:: CRIS | |
13656 | * Super-H:: Renesas Super-H | |
c45da7e6 | 13657 | * WinCE:: Windows CE child processes |
104c1213 JM |
13658 | @end menu |
13659 | ||
6d2ebf8b | 13660 | @node ARM |
104c1213 | 13661 | @subsection ARM |
c45da7e6 | 13662 | @cindex ARM RDI |
104c1213 JM |
13663 | |
13664 | @table @code | |
8e04817f AC |
13665 | @kindex target rdi |
13666 | @item target rdi @var{dev} | |
13667 | ARM Angel monitor, via RDI library interface to ADP protocol. You may | |
13668 | use this target to communicate with both boards running the Angel | |
13669 | monitor, or with the EmbeddedICE JTAG debug device. | |
13670 | ||
13671 | @kindex target rdp | |
13672 | @item target rdp @var{dev} | |
13673 | ARM Demon monitor. | |
13674 | ||
13675 | @end table | |
13676 | ||
e2f4edfd EZ |
13677 | @value{GDBN} provides the following ARM-specific commands: |
13678 | ||
13679 | @table @code | |
13680 | @item set arm disassembler | |
13681 | @kindex set arm | |
13682 | This commands selects from a list of disassembly styles. The | |
13683 | @code{"std"} style is the standard style. | |
13684 | ||
13685 | @item show arm disassembler | |
13686 | @kindex show arm | |
13687 | Show the current disassembly style. | |
13688 | ||
13689 | @item set arm apcs32 | |
13690 | @cindex ARM 32-bit mode | |
13691 | This command toggles ARM operation mode between 32-bit and 26-bit. | |
13692 | ||
13693 | @item show arm apcs32 | |
13694 | Display the current usage of the ARM 32-bit mode. | |
13695 | ||
13696 | @item set arm fpu @var{fputype} | |
13697 | This command sets the ARM floating-point unit (FPU) type. The | |
13698 | argument @var{fputype} can be one of these: | |
13699 | ||
13700 | @table @code | |
13701 | @item auto | |
13702 | Determine the FPU type by querying the OS ABI. | |
13703 | @item softfpa | |
13704 | Software FPU, with mixed-endian doubles on little-endian ARM | |
13705 | processors. | |
13706 | @item fpa | |
13707 | GCC-compiled FPA co-processor. | |
13708 | @item softvfp | |
13709 | Software FPU with pure-endian doubles. | |
13710 | @item vfp | |
13711 | VFP co-processor. | |
13712 | @end table | |
13713 | ||
13714 | @item show arm fpu | |
13715 | Show the current type of the FPU. | |
13716 | ||
13717 | @item set arm abi | |
13718 | This command forces @value{GDBN} to use the specified ABI. | |
13719 | ||
13720 | @item show arm abi | |
13721 | Show the currently used ABI. | |
13722 | ||
13723 | @item set debug arm | |
13724 | Toggle whether to display ARM-specific debugging messages from the ARM | |
13725 | target support subsystem. | |
13726 | ||
13727 | @item show debug arm | |
13728 | Show whether ARM-specific debugging messages are enabled. | |
13729 | @end table | |
13730 | ||
c45da7e6 EZ |
13731 | The following commands are available when an ARM target is debugged |
13732 | using the RDI interface: | |
13733 | ||
13734 | @table @code | |
13735 | @item rdilogfile @r{[}@var{file}@r{]} | |
13736 | @kindex rdilogfile | |
13737 | @cindex ADP (Angel Debugger Protocol) logging | |
13738 | Set the filename for the ADP (Angel Debugger Protocol) packet log. | |
13739 | With an argument, sets the log file to the specified @var{file}. With | |
13740 | no argument, show the current log file name. The default log file is | |
13741 | @file{rdi.log}. | |
13742 | ||
13743 | @item rdilogenable @r{[}@var{arg}@r{]} | |
13744 | @kindex rdilogenable | |
13745 | Control logging of ADP packets. With an argument of 1 or @code{"yes"} | |
13746 | enables logging, with an argument 0 or @code{"no"} disables it. With | |
13747 | no arguments displays the current setting. When logging is enabled, | |
13748 | ADP packets exchanged between @value{GDBN} and the RDI target device | |
13749 | are logged to a file. | |
13750 | ||
13751 | @item set rdiromatzero | |
13752 | @kindex set rdiromatzero | |
13753 | @cindex ROM at zero address, RDI | |
13754 | Tell @value{GDBN} whether the target has ROM at address 0. If on, | |
13755 | vector catching is disabled, so that zero address can be used. If off | |
13756 | (the default), vector catching is enabled. For this command to take | |
13757 | effect, it needs to be invoked prior to the @code{target rdi} command. | |
13758 | ||
13759 | @item show rdiromatzero | |
13760 | @kindex show rdiromatzero | |
13761 | Show the current setting of ROM at zero address. | |
13762 | ||
13763 | @item set rdiheartbeat | |
13764 | @kindex set rdiheartbeat | |
13765 | @cindex RDI heartbeat | |
13766 | Enable or disable RDI heartbeat packets. It is not recommended to | |
13767 | turn on this option, since it confuses ARM and EPI JTAG interface, as | |
13768 | well as the Angel monitor. | |
13769 | ||
13770 | @item show rdiheartbeat | |
13771 | @kindex show rdiheartbeat | |
13772 | Show the setting of RDI heartbeat packets. | |
13773 | @end table | |
13774 | ||
e2f4edfd | 13775 | |
8e04817f | 13776 | @node H8/300 |
172c2a43 | 13777 | @subsection Renesas H8/300 |
8e04817f AC |
13778 | |
13779 | @table @code | |
13780 | ||
13781 | @kindex target hms@r{, with H8/300} | |
13782 | @item target hms @var{dev} | |
172c2a43 | 13783 | A Renesas SH, H8/300, or H8/500 board, attached via serial line to your host. |
8e04817f AC |
13784 | Use special commands @code{device} and @code{speed} to control the serial |
13785 | line and the communications speed used. | |
13786 | ||
13787 | @kindex target e7000@r{, with H8/300} | |
13788 | @item target e7000 @var{dev} | |
172c2a43 | 13789 | E7000 emulator for Renesas H8 and SH. |
8e04817f AC |
13790 | |
13791 | @kindex target sh3@r{, with H8/300} | |
13792 | @kindex target sh3e@r{, with H8/300} | |
13793 | @item target sh3 @var{dev} | |
13794 | @itemx target sh3e @var{dev} | |
172c2a43 | 13795 | Renesas SH-3 and SH-3E target systems. |
8e04817f AC |
13796 | |
13797 | @end table | |
13798 | ||
13799 | @cindex download to H8/300 or H8/500 | |
13800 | @cindex H8/300 or H8/500 download | |
172c2a43 KI |
13801 | @cindex download to Renesas SH |
13802 | @cindex Renesas SH download | |
13803 | When you select remote debugging to a Renesas SH, H8/300, or H8/500 | |
13804 | board, the @code{load} command downloads your program to the Renesas | |
8e04817f AC |
13805 | board and also opens it as the current executable target for |
13806 | @value{GDBN} on your host (like the @code{file} command). | |
13807 | ||
13808 | @value{GDBN} needs to know these things to talk to your | |
172c2a43 | 13809 | Renesas SH, H8/300, or H8/500: |
8e04817f AC |
13810 | |
13811 | @enumerate | |
13812 | @item | |
13813 | that you want to use @samp{target hms}, the remote debugging interface | |
172c2a43 KI |
13814 | for Renesas microprocessors, or @samp{target e7000}, the in-circuit |
13815 | emulator for the Renesas SH and the Renesas 300H. (@samp{target hms} is | |
13816 | the default when @value{GDBN} is configured specifically for the Renesas SH, | |
8e04817f AC |
13817 | H8/300, or H8/500.) |
13818 | ||
13819 | @item | |
172c2a43 | 13820 | what serial device connects your host to your Renesas board (the first |
8e04817f AC |
13821 | serial device available on your host is the default). |
13822 | ||
13823 | @item | |
13824 | what speed to use over the serial device. | |
13825 | @end enumerate | |
13826 | ||
13827 | @menu | |
172c2a43 KI |
13828 | * Renesas Boards:: Connecting to Renesas boards. |
13829 | * Renesas ICE:: Using the E7000 In-Circuit Emulator. | |
13830 | * Renesas Special:: Special @value{GDBN} commands for Renesas micros. | |
8e04817f AC |
13831 | @end menu |
13832 | ||
172c2a43 KI |
13833 | @node Renesas Boards |
13834 | @subsubsection Connecting to Renesas boards | |
8e04817f AC |
13835 | |
13836 | @c only for Unix hosts | |
13837 | @kindex device | |
172c2a43 | 13838 | @cindex serial device, Renesas micros |
8e04817f AC |
13839 | Use the special @code{@value{GDBN}} command @samp{device @var{port}} if you |
13840 | need to explicitly set the serial device. The default @var{port} is the | |
13841 | first available port on your host. This is only necessary on Unix | |
13842 | hosts, where it is typically something like @file{/dev/ttya}. | |
13843 | ||
13844 | @kindex speed | |
172c2a43 | 13845 | @cindex serial line speed, Renesas micros |
8e04817f AC |
13846 | @code{@value{GDBN}} has another special command to set the communications |
13847 | speed: @samp{speed @var{bps}}. This command also is only used from Unix | |
13848 | hosts; on DOS hosts, set the line speed as usual from outside @value{GDBN} with | |
13849 | the DOS @code{mode} command (for instance, | |
13850 | @w{@kbd{mode com2:9600,n,8,1,p}} for a 9600@dmn{bps} connection). | |
13851 | ||
13852 | The @samp{device} and @samp{speed} commands are available only when you | |
172c2a43 | 13853 | use a Unix host to debug your Renesas microprocessor programs. If you |
8e04817f AC |
13854 | use a DOS host, |
13855 | @value{GDBN} depends on an auxiliary terminate-and-stay-resident program | |
13856 | called @code{asynctsr} to communicate with the development board | |
13857 | through a PC serial port. You must also use the DOS @code{mode} command | |
13858 | to set up the serial port on the DOS side. | |
13859 | ||
13860 | The following sample session illustrates the steps needed to start a | |
13861 | program under @value{GDBN} control on an H8/300. The example uses a | |
13862 | sample H8/300 program called @file{t.x}. The procedure is the same for | |
172c2a43 | 13863 | the Renesas SH and the H8/500. |
8e04817f AC |
13864 | |
13865 | First hook up your development board. In this example, we use a | |
13866 | board attached to serial port @code{COM2}; if you use a different serial | |
13867 | port, substitute its name in the argument of the @code{mode} command. | |
13868 | When you call @code{asynctsr}, the auxiliary comms program used by the | |
13869 | debugger, you give it just the numeric part of the serial port's name; | |
13870 | for example, @samp{asyncstr 2} below runs @code{asyncstr} on | |
13871 | @code{COM2}. | |
13872 | ||
474c8240 | 13873 | @smallexample |
8e04817f AC |
13874 | C:\H8300\TEST> asynctsr 2 |
13875 | C:\H8300\TEST> mode com2:9600,n,8,1,p | |
13876 | ||
13877 | Resident portion of MODE loaded | |
13878 | ||
13879 | COM2: 9600, n, 8, 1, p | |
13880 | ||
474c8240 | 13881 | @end smallexample |
8e04817f AC |
13882 | |
13883 | @quotation | |
13884 | @emph{Warning:} We have noticed a bug in PC-NFS that conflicts with | |
13885 | @code{asynctsr}. If you also run PC-NFS on your DOS host, you may need to | |
13886 | disable it, or even boot without it, to use @code{asynctsr} to control | |
13887 | your development board. | |
13888 | @end quotation | |
13889 | ||
13890 | @kindex target hms@r{, and serial protocol} | |
13891 | Now that serial communications are set up, and the development board is | |
9c16f35a | 13892 | connected, you can start up @value{GDBN}. Call @code{@value{GDBN}} with |
8e04817f AC |
13893 | the name of your program as the argument. @code{@value{GDBN}} prompts |
13894 | you, as usual, with the prompt @samp{(@value{GDBP})}. Use two special | |
13895 | commands to begin your debugging session: @samp{target hms} to specify | |
172c2a43 | 13896 | cross-debugging to the Renesas board, and the @code{load} command to |
8e04817f AC |
13897 | download your program to the board. @code{load} displays the names of |
13898 | the program's sections, and a @samp{*} for each 2K of data downloaded. | |
13899 | (If you want to refresh @value{GDBN} data on symbols or on the | |
13900 | executable file without downloading, use the @value{GDBN} commands | |
13901 | @code{file} or @code{symbol-file}. These commands, and @code{load} | |
13902 | itself, are described in @ref{Files,,Commands to specify files}.) | |
13903 | ||
13904 | @smallexample | |
13905 | (eg-C:\H8300\TEST) @value{GDBP} t.x | |
13906 | @value{GDBN} is free software and you are welcome to distribute copies | |
13907 | of it under certain conditions; type "show copying" to see | |
13908 | the conditions. | |
13909 | There is absolutely no warranty for @value{GDBN}; type "show warranty" | |
13910 | for details. | |
13911 | @value{GDBN} @value{GDBVN}, Copyright 1992 Free Software Foundation, Inc... | |
13912 | (@value{GDBP}) target hms | |
13913 | Connected to remote H8/300 HMS system. | |
13914 | (@value{GDBP}) load t.x | |
13915 | .text : 0x8000 .. 0xabde *********** | |
13916 | .data : 0xabde .. 0xad30 * | |
13917 | .stack : 0xf000 .. 0xf014 * | |
13918 | @end smallexample | |
13919 | ||
13920 | At this point, you're ready to run or debug your program. From here on, | |
13921 | you can use all the usual @value{GDBN} commands. The @code{break} command | |
13922 | sets breakpoints; the @code{run} command starts your program; | |
13923 | @code{print} or @code{x} display data; the @code{continue} command | |
13924 | resumes execution after stopping at a breakpoint. You can use the | |
13925 | @code{help} command at any time to find out more about @value{GDBN} commands. | |
13926 | ||
13927 | Remember, however, that @emph{operating system} facilities aren't | |
13928 | available on your development board; for example, if your program hangs, | |
13929 | you can't send an interrupt---but you can press the @sc{reset} switch! | |
13930 | ||
13931 | Use the @sc{reset} button on the development board | |
13932 | @itemize @bullet | |
13933 | @item | |
13934 | to interrupt your program (don't use @kbd{ctl-C} on the DOS host---it has | |
13935 | no way to pass an interrupt signal to the development board); and | |
13936 | ||
13937 | @item | |
13938 | to return to the @value{GDBN} command prompt after your program finishes | |
13939 | normally. The communications protocol provides no other way for @value{GDBN} | |
13940 | to detect program completion. | |
13941 | @end itemize | |
13942 | ||
13943 | In either case, @value{GDBN} sees the effect of a @sc{reset} on the | |
13944 | development board as a ``normal exit'' of your program. | |
13945 | ||
172c2a43 | 13946 | @node Renesas ICE |
8e04817f AC |
13947 | @subsubsection Using the E7000 in-circuit emulator |
13948 | ||
172c2a43 | 13949 | @kindex target e7000@r{, with Renesas ICE} |
8e04817f | 13950 | You can use the E7000 in-circuit emulator to develop code for either the |
172c2a43 | 13951 | Renesas SH or the H8/300H. Use one of these forms of the @samp{target |
8e04817f AC |
13952 | e7000} command to connect @value{GDBN} to your E7000: |
13953 | ||
13954 | @table @code | |
13955 | @item target e7000 @var{port} @var{speed} | |
13956 | Use this form if your E7000 is connected to a serial port. The | |
13957 | @var{port} argument identifies what serial port to use (for example, | |
13958 | @samp{com2}). The third argument is the line speed in bits per second | |
13959 | (for example, @samp{9600}). | |
13960 | ||
13961 | @item target e7000 @var{hostname} | |
13962 | If your E7000 is installed as a host on a TCP/IP network, you can just | |
13963 | specify its hostname; @value{GDBN} uses @code{telnet} to connect. | |
13964 | @end table | |
13965 | ||
ba04e063 EZ |
13966 | The following special commands are available when debugging with the |
13967 | Renesas E7000 ICE: | |
13968 | ||
13969 | @table @code | |
13970 | @item e7000 @var{command} | |
13971 | @kindex e7000 | |
13972 | @cindex send command to E7000 monitor | |
13973 | This sends the specified @var{command} to the E7000 monitor. | |
13974 | ||
13975 | @item ftplogin @var{machine} @var{username} @var{password} @var{dir} | |
13976 | @kindex ftplogin@r{, E7000} | |
13977 | This command records information for subsequent interface with the | |
13978 | E7000 monitor via the FTP protocol: @value{GDBN} will log into the | |
13979 | named @var{machine} using specified @var{username} and @var{password}, | |
13980 | and then chdir to the named directory @var{dir}. | |
13981 | ||
13982 | @item ftpload @var{file} | |
13983 | @kindex ftpload@r{, E7000} | |
13984 | This command uses credentials recorded by @code{ftplogin} to fetch and | |
13985 | load the named @var{file} from the E7000 monitor. | |
13986 | ||
13987 | @item drain | |
13988 | @kindex drain@r{, E7000} | |
13989 | This command drains any pending text buffers stored on the E7000. | |
13990 | ||
13991 | @item set usehardbreakpoints | |
13992 | @itemx show usehardbreakpoints | |
13993 | @kindex set usehardbreakpoints@r{, E7000} | |
13994 | @kindex show usehardbreakpoints@r{, E7000} | |
13995 | @cindex hardware breakpoints, and E7000 | |
13996 | These commands set and show the use of hardware breakpoints for all | |
13997 | breakpoints. @xref{Set Breaks, hardware-assisted breakpoint}, for | |
13998 | more information about using hardware breakpoints selectively. | |
13999 | @end table | |
14000 | ||
172c2a43 KI |
14001 | @node Renesas Special |
14002 | @subsubsection Special @value{GDBN} commands for Renesas micros | |
8e04817f AC |
14003 | |
14004 | Some @value{GDBN} commands are available only for the H8/300: | |
14005 | ||
14006 | @table @code | |
14007 | ||
14008 | @kindex set machine | |
14009 | @kindex show machine | |
14010 | @item set machine h8300 | |
14011 | @itemx set machine h8300h | |
14012 | Condition @value{GDBN} for one of the two variants of the H8/300 | |
14013 | architecture with @samp{set machine}. You can use @samp{show machine} | |
14014 | to check which variant is currently in effect. | |
104c1213 JM |
14015 | |
14016 | @end table | |
14017 | ||
8e04817f AC |
14018 | @node H8/500 |
14019 | @subsection H8/500 | |
104c1213 JM |
14020 | |
14021 | @table @code | |
14022 | ||
8e04817f AC |
14023 | @kindex set memory @var{mod} |
14024 | @cindex memory models, H8/500 | |
14025 | @item set memory @var{mod} | |
14026 | @itemx show memory | |
14027 | Specify which H8/500 memory model (@var{mod}) you are using with | |
14028 | @samp{set memory}; check which memory model is in effect with @samp{show | |
14029 | memory}. The accepted values for @var{mod} are @code{small}, | |
14030 | @code{big}, @code{medium}, and @code{compact}. | |
104c1213 | 14031 | |
8e04817f | 14032 | @end table |
104c1213 | 14033 | |
8e04817f | 14034 | @node M32R/D |
ba04e063 | 14035 | @subsection Renesas M32R/D and M32R/SDI |
8e04817f AC |
14036 | |
14037 | @table @code | |
8e04817f AC |
14038 | @kindex target m32r |
14039 | @item target m32r @var{dev} | |
172c2a43 | 14040 | Renesas M32R/D ROM monitor. |
8e04817f | 14041 | |
fb3e19c0 KI |
14042 | @kindex target m32rsdi |
14043 | @item target m32rsdi @var{dev} | |
14044 | Renesas M32R SDI server, connected via parallel port to the board. | |
721c2651 EZ |
14045 | @end table |
14046 | ||
14047 | The following @value{GDBN} commands are specific to the M32R monitor: | |
14048 | ||
14049 | @table @code | |
14050 | @item set download-path @var{path} | |
14051 | @kindex set download-path | |
14052 | @cindex find downloadable @sc{srec} files (M32R) | |
14053 | Set the default path for finding donwloadable @sc{srec} files. | |
14054 | ||
14055 | @item show download-path | |
14056 | @kindex show download-path | |
14057 | Show the default path for downloadable @sc{srec} files. | |
fb3e19c0 | 14058 | |
721c2651 EZ |
14059 | @item set board-address @var{addr} |
14060 | @kindex set board-address | |
14061 | @cindex M32-EVA target board address | |
14062 | Set the IP address for the M32R-EVA target board. | |
14063 | ||
14064 | @item show board-address | |
14065 | @kindex show board-address | |
14066 | Show the current IP address of the target board. | |
14067 | ||
14068 | @item set server-address @var{addr} | |
14069 | @kindex set server-address | |
14070 | @cindex download server address (M32R) | |
14071 | Set the IP address for the download server, which is the @value{GDBN}'s | |
14072 | host machine. | |
14073 | ||
14074 | @item show server-address | |
14075 | @kindex show server-address | |
14076 | Display the IP address of the download server. | |
14077 | ||
14078 | @item upload @r{[}@var{file}@r{]} | |
14079 | @kindex upload@r{, M32R} | |
14080 | Upload the specified @sc{srec} @var{file} via the monitor's Ethernet | |
14081 | upload capability. If no @var{file} argument is given, the current | |
14082 | executable file is uploaded. | |
14083 | ||
14084 | @item tload @r{[}@var{file}@r{]} | |
14085 | @kindex tload@r{, M32R} | |
14086 | Test the @code{upload} command. | |
8e04817f AC |
14087 | @end table |
14088 | ||
ba04e063 EZ |
14089 | The following commands are available for M32R/SDI: |
14090 | ||
14091 | @table @code | |
14092 | @item sdireset | |
14093 | @kindex sdireset | |
14094 | @cindex reset SDI connection, M32R | |
14095 | This command resets the SDI connection. | |
14096 | ||
14097 | @item sdistatus | |
14098 | @kindex sdistatus | |
14099 | This command shows the SDI connection status. | |
14100 | ||
14101 | @item debug_chaos | |
14102 | @kindex debug_chaos | |
14103 | @cindex M32R/Chaos debugging | |
14104 | Instructs the remote that M32R/Chaos debugging is to be used. | |
14105 | ||
14106 | @item use_debug_dma | |
14107 | @kindex use_debug_dma | |
14108 | Instructs the remote to use the DEBUG_DMA method of accessing memory. | |
14109 | ||
14110 | @item use_mon_code | |
14111 | @kindex use_mon_code | |
14112 | Instructs the remote to use the MON_CODE method of accessing memory. | |
14113 | ||
14114 | @item use_ib_break | |
14115 | @kindex use_ib_break | |
14116 | Instructs the remote to set breakpoints by IB break. | |
14117 | ||
14118 | @item use_dbt_break | |
14119 | @kindex use_dbt_break | |
14120 | Instructs the remote to set breakpoints by DBT. | |
14121 | @end table | |
14122 | ||
8e04817f AC |
14123 | @node M68K |
14124 | @subsection M68k | |
14125 | ||
14126 | The Motorola m68k configuration includes ColdFire support, and | |
14127 | target command for the following ROM monitors. | |
14128 | ||
14129 | @table @code | |
14130 | ||
14131 | @kindex target abug | |
14132 | @item target abug @var{dev} | |
14133 | ABug ROM monitor for M68K. | |
14134 | ||
14135 | @kindex target cpu32bug | |
14136 | @item target cpu32bug @var{dev} | |
14137 | CPU32BUG monitor, running on a CPU32 (M68K) board. | |
14138 | ||
14139 | @kindex target dbug | |
14140 | @item target dbug @var{dev} | |
14141 | dBUG ROM monitor for Motorola ColdFire. | |
14142 | ||
14143 | @kindex target est | |
14144 | @item target est @var{dev} | |
14145 | EST-300 ICE monitor, running on a CPU32 (M68K) board. | |
14146 | ||
14147 | @kindex target rom68k | |
14148 | @item target rom68k @var{dev} | |
14149 | ROM 68K monitor, running on an M68K IDP board. | |
14150 | ||
14151 | @end table | |
14152 | ||
8e04817f AC |
14153 | @table @code |
14154 | ||
14155 | @kindex target rombug | |
14156 | @item target rombug @var{dev} | |
14157 | ROMBUG ROM monitor for OS/9000. | |
14158 | ||
14159 | @end table | |
14160 | ||
8e04817f AC |
14161 | @node MIPS Embedded |
14162 | @subsection MIPS Embedded | |
14163 | ||
14164 | @cindex MIPS boards | |
14165 | @value{GDBN} can use the MIPS remote debugging protocol to talk to a | |
14166 | MIPS board attached to a serial line. This is available when | |
14167 | you configure @value{GDBN} with @samp{--target=mips-idt-ecoff}. | |
104c1213 | 14168 | |
8e04817f AC |
14169 | @need 1000 |
14170 | Use these @value{GDBN} commands to specify the connection to your target board: | |
104c1213 | 14171 | |
8e04817f AC |
14172 | @table @code |
14173 | @item target mips @var{port} | |
14174 | @kindex target mips @var{port} | |
14175 | To run a program on the board, start up @code{@value{GDBP}} with the | |
14176 | name of your program as the argument. To connect to the board, use the | |
14177 | command @samp{target mips @var{port}}, where @var{port} is the name of | |
14178 | the serial port connected to the board. If the program has not already | |
14179 | been downloaded to the board, you may use the @code{load} command to | |
14180 | download it. You can then use all the usual @value{GDBN} commands. | |
104c1213 | 14181 | |
8e04817f AC |
14182 | For example, this sequence connects to the target board through a serial |
14183 | port, and loads and runs a program called @var{prog} through the | |
14184 | debugger: | |
104c1213 | 14185 | |
474c8240 | 14186 | @smallexample |
8e04817f AC |
14187 | host$ @value{GDBP} @var{prog} |
14188 | @value{GDBN} is free software and @dots{} | |
14189 | (@value{GDBP}) target mips /dev/ttyb | |
14190 | (@value{GDBP}) load @var{prog} | |
14191 | (@value{GDBP}) run | |
474c8240 | 14192 | @end smallexample |
104c1213 | 14193 | |
8e04817f AC |
14194 | @item target mips @var{hostname}:@var{portnumber} |
14195 | On some @value{GDBN} host configurations, you can specify a TCP | |
14196 | connection (for instance, to a serial line managed by a terminal | |
14197 | concentrator) instead of a serial port, using the syntax | |
14198 | @samp{@var{hostname}:@var{portnumber}}. | |
104c1213 | 14199 | |
8e04817f AC |
14200 | @item target pmon @var{port} |
14201 | @kindex target pmon @var{port} | |
14202 | PMON ROM monitor. | |
104c1213 | 14203 | |
8e04817f AC |
14204 | @item target ddb @var{port} |
14205 | @kindex target ddb @var{port} | |
14206 | NEC's DDB variant of PMON for Vr4300. | |
104c1213 | 14207 | |
8e04817f AC |
14208 | @item target lsi @var{port} |
14209 | @kindex target lsi @var{port} | |
14210 | LSI variant of PMON. | |
104c1213 | 14211 | |
8e04817f AC |
14212 | @kindex target r3900 |
14213 | @item target r3900 @var{dev} | |
14214 | Densan DVE-R3900 ROM monitor for Toshiba R3900 Mips. | |
104c1213 | 14215 | |
8e04817f AC |
14216 | @kindex target array |
14217 | @item target array @var{dev} | |
14218 | Array Tech LSI33K RAID controller board. | |
104c1213 | 14219 | |
8e04817f | 14220 | @end table |
104c1213 | 14221 | |
104c1213 | 14222 | |
8e04817f AC |
14223 | @noindent |
14224 | @value{GDBN} also supports these special commands for MIPS targets: | |
104c1213 | 14225 | |
8e04817f | 14226 | @table @code |
8e04817f AC |
14227 | @item set mipsfpu double |
14228 | @itemx set mipsfpu single | |
14229 | @itemx set mipsfpu none | |
a64548ea | 14230 | @itemx set mipsfpu auto |
8e04817f AC |
14231 | @itemx show mipsfpu |
14232 | @kindex set mipsfpu | |
14233 | @kindex show mipsfpu | |
14234 | @cindex MIPS remote floating point | |
14235 | @cindex floating point, MIPS remote | |
14236 | If your target board does not support the MIPS floating point | |
14237 | coprocessor, you should use the command @samp{set mipsfpu none} (if you | |
14238 | need this, you may wish to put the command in your @value{GDBN} init | |
14239 | file). This tells @value{GDBN} how to find the return value of | |
14240 | functions which return floating point values. It also allows | |
14241 | @value{GDBN} to avoid saving the floating point registers when calling | |
14242 | functions on the board. If you are using a floating point coprocessor | |
14243 | with only single precision floating point support, as on the @sc{r4650} | |
14244 | processor, use the command @samp{set mipsfpu single}. The default | |
14245 | double precision floating point coprocessor may be selected using | |
14246 | @samp{set mipsfpu double}. | |
104c1213 | 14247 | |
8e04817f AC |
14248 | In previous versions the only choices were double precision or no |
14249 | floating point, so @samp{set mipsfpu on} will select double precision | |
14250 | and @samp{set mipsfpu off} will select no floating point. | |
104c1213 | 14251 | |
8e04817f AC |
14252 | As usual, you can inquire about the @code{mipsfpu} variable with |
14253 | @samp{show mipsfpu}. | |
104c1213 | 14254 | |
8e04817f AC |
14255 | @item set timeout @var{seconds} |
14256 | @itemx set retransmit-timeout @var{seconds} | |
14257 | @itemx show timeout | |
14258 | @itemx show retransmit-timeout | |
14259 | @cindex @code{timeout}, MIPS protocol | |
14260 | @cindex @code{retransmit-timeout}, MIPS protocol | |
14261 | @kindex set timeout | |
14262 | @kindex show timeout | |
14263 | @kindex set retransmit-timeout | |
14264 | @kindex show retransmit-timeout | |
14265 | You can control the timeout used while waiting for a packet, in the MIPS | |
14266 | remote protocol, with the @code{set timeout @var{seconds}} command. The | |
14267 | default is 5 seconds. Similarly, you can control the timeout used while | |
14268 | waiting for an acknowledgement of a packet with the @code{set | |
14269 | retransmit-timeout @var{seconds}} command. The default is 3 seconds. | |
14270 | You can inspect both values with @code{show timeout} and @code{show | |
14271 | retransmit-timeout}. (These commands are @emph{only} available when | |
14272 | @value{GDBN} is configured for @samp{--target=mips-idt-ecoff}.) | |
104c1213 | 14273 | |
8e04817f AC |
14274 | The timeout set by @code{set timeout} does not apply when @value{GDBN} |
14275 | is waiting for your program to stop. In that case, @value{GDBN} waits | |
14276 | forever because it has no way of knowing how long the program is going | |
14277 | to run before stopping. | |
ba04e063 EZ |
14278 | |
14279 | @item set syn-garbage-limit @var{num} | |
14280 | @kindex set syn-garbage-limit@r{, MIPS remote} | |
14281 | @cindex synchronize with remote MIPS target | |
14282 | Limit the maximum number of characters @value{GDBN} should ignore when | |
14283 | it tries to synchronize with the remote target. The default is 10 | |
14284 | characters. Setting the limit to -1 means there's no limit. | |
14285 | ||
14286 | @item show syn-garbage-limit | |
14287 | @kindex show syn-garbage-limit@r{, MIPS remote} | |
14288 | Show the current limit on the number of characters to ignore when | |
14289 | trying to synchronize with the remote system. | |
14290 | ||
14291 | @item set monitor-prompt @var{prompt} | |
14292 | @kindex set monitor-prompt@r{, MIPS remote} | |
14293 | @cindex remote monitor prompt | |
14294 | Tell @value{GDBN} to expect the specified @var{prompt} string from the | |
14295 | remote monitor. The default depends on the target: | |
14296 | @table @asis | |
14297 | @item pmon target | |
14298 | @samp{PMON} | |
14299 | @item ddb target | |
14300 | @samp{NEC010} | |
14301 | @item lsi target | |
14302 | @samp{PMON>} | |
14303 | @end table | |
14304 | ||
14305 | @item show monitor-prompt | |
14306 | @kindex show monitor-prompt@r{, MIPS remote} | |
14307 | Show the current strings @value{GDBN} expects as the prompt from the | |
14308 | remote monitor. | |
14309 | ||
14310 | @item set monitor-warnings | |
14311 | @kindex set monitor-warnings@r{, MIPS remote} | |
14312 | Enable or disable monitor warnings about hardware breakpoints. This | |
14313 | has effect only for the @code{lsi} target. When on, @value{GDBN} will | |
14314 | display warning messages whose codes are returned by the @code{lsi} | |
14315 | PMON monitor for breakpoint commands. | |
14316 | ||
14317 | @item show monitor-warnings | |
14318 | @kindex show monitor-warnings@r{, MIPS remote} | |
14319 | Show the current setting of printing monitor warnings. | |
14320 | ||
14321 | @item pmon @var{command} | |
14322 | @kindex pmon@r{, MIPS remote} | |
14323 | @cindex send PMON command | |
14324 | This command allows sending an arbitrary @var{command} string to the | |
14325 | monitor. The monitor must be in debug mode for this to work. | |
8e04817f | 14326 | @end table |
104c1213 | 14327 | |
a37295f9 MM |
14328 | @node OpenRISC 1000 |
14329 | @subsection OpenRISC 1000 | |
14330 | @cindex OpenRISC 1000 | |
14331 | ||
14332 | @cindex or1k boards | |
14333 | See OR1k Architecture document (@uref{www.opencores.org}) for more information | |
14334 | about platform and commands. | |
14335 | ||
14336 | @table @code | |
14337 | ||
14338 | @kindex target jtag | |
14339 | @item target jtag jtag://@var{host}:@var{port} | |
14340 | ||
14341 | Connects to remote JTAG server. | |
14342 | JTAG remote server can be either an or1ksim or JTAG server, | |
14343 | connected via parallel port to the board. | |
14344 | ||
14345 | Example: @code{target jtag jtag://localhost:9999} | |
14346 | ||
14347 | @kindex or1ksim | |
14348 | @item or1ksim @var{command} | |
14349 | If connected to @code{or1ksim} OpenRISC 1000 Architectural | |
14350 | Simulator, proprietary commands can be executed. | |
14351 | ||
14352 | @kindex info or1k spr | |
14353 | @item info or1k spr | |
14354 | Displays spr groups. | |
14355 | ||
14356 | @item info or1k spr @var{group} | |
14357 | @itemx info or1k spr @var{groupno} | |
14358 | Displays register names in selected group. | |
14359 | ||
14360 | @item info or1k spr @var{group} @var{register} | |
14361 | @itemx info or1k spr @var{register} | |
14362 | @itemx info or1k spr @var{groupno} @var{registerno} | |
14363 | @itemx info or1k spr @var{registerno} | |
14364 | Shows information about specified spr register. | |
14365 | ||
14366 | @kindex spr | |
14367 | @item spr @var{group} @var{register} @var{value} | |
14368 | @itemx spr @var{register @var{value}} | |
14369 | @itemx spr @var{groupno} @var{registerno @var{value}} | |
14370 | @itemx spr @var{registerno @var{value}} | |
14371 | Writes @var{value} to specified spr register. | |
14372 | @end table | |
14373 | ||
14374 | Some implementations of OpenRISC 1000 Architecture also have hardware trace. | |
14375 | It is very similar to @value{GDBN} trace, except it does not interfere with normal | |
14376 | program execution and is thus much faster. Hardware breakpoints/watchpoint | |
14377 | triggers can be set using: | |
14378 | @table @code | |
14379 | @item $LEA/$LDATA | |
14380 | Load effective address/data | |
14381 | @item $SEA/$SDATA | |
14382 | Store effective address/data | |
14383 | @item $AEA/$ADATA | |
14384 | Access effective address ($SEA or $LEA) or data ($SDATA/$LDATA) | |
14385 | @item $FETCH | |
14386 | Fetch data | |
14387 | @end table | |
14388 | ||
14389 | When triggered, it can capture low level data, like: @code{PC}, @code{LSEA}, | |
14390 | @code{LDATA}, @code{SDATA}, @code{READSPR}, @code{WRITESPR}, @code{INSTR}. | |
14391 | ||
14392 | @code{htrace} commands: | |
14393 | @cindex OpenRISC 1000 htrace | |
14394 | @table @code | |
14395 | @kindex hwatch | |
14396 | @item hwatch @var{conditional} | |
14397 | Set hardware watchpoint on combination of Load/Store Effecive Address(es) | |
14398 | or Data. For example: | |
14399 | ||
14400 | @code{hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) && ($SDATA >= 50)} | |
14401 | ||
14402 | @code{hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) && ($SDATA >= 50)} | |
14403 | ||
4644b6e3 | 14404 | @kindex htrace |
a37295f9 MM |
14405 | @item htrace info |
14406 | Display information about current HW trace configuration. | |
14407 | ||
a37295f9 MM |
14408 | @item htrace trigger @var{conditional} |
14409 | Set starting criteria for HW trace. | |
14410 | ||
a37295f9 MM |
14411 | @item htrace qualifier @var{conditional} |
14412 | Set acquisition qualifier for HW trace. | |
14413 | ||
a37295f9 MM |
14414 | @item htrace stop @var{conditional} |
14415 | Set HW trace stopping criteria. | |
14416 | ||
f153cc92 | 14417 | @item htrace record [@var{data}]* |
a37295f9 MM |
14418 | Selects the data to be recorded, when qualifier is met and HW trace was |
14419 | triggered. | |
14420 | ||
a37295f9 | 14421 | @item htrace enable |
a37295f9 MM |
14422 | @itemx htrace disable |
14423 | Enables/disables the HW trace. | |
14424 | ||
f153cc92 | 14425 | @item htrace rewind [@var{filename}] |
a37295f9 MM |
14426 | Clears currently recorded trace data. |
14427 | ||
14428 | If filename is specified, new trace file is made and any newly collected data | |
14429 | will be written there. | |
14430 | ||
f153cc92 | 14431 | @item htrace print [@var{start} [@var{len}]] |
a37295f9 MM |
14432 | Prints trace buffer, using current record configuration. |
14433 | ||
a37295f9 MM |
14434 | @item htrace mode continuous |
14435 | Set continuous trace mode. | |
14436 | ||
a37295f9 MM |
14437 | @item htrace mode suspend |
14438 | Set suspend trace mode. | |
14439 | ||
14440 | @end table | |
14441 | ||
8e04817f AC |
14442 | @node PowerPC |
14443 | @subsection PowerPC | |
104c1213 JM |
14444 | |
14445 | @table @code | |
8e04817f AC |
14446 | @kindex target dink32 |
14447 | @item target dink32 @var{dev} | |
14448 | DINK32 ROM monitor. | |
104c1213 | 14449 | |
8e04817f AC |
14450 | @kindex target ppcbug |
14451 | @item target ppcbug @var{dev} | |
14452 | @kindex target ppcbug1 | |
14453 | @item target ppcbug1 @var{dev} | |
14454 | PPCBUG ROM monitor for PowerPC. | |
104c1213 | 14455 | |
8e04817f AC |
14456 | @kindex target sds |
14457 | @item target sds @var{dev} | |
14458 | SDS monitor, running on a PowerPC board (such as Motorola's ADS). | |
c45da7e6 | 14459 | @end table |
8e04817f | 14460 | |
c45da7e6 EZ |
14461 | @cindex SDS protocol |
14462 | The following commands specifi to the SDS protocol are supported | |
14463 | by@value{GDBN}: | |
14464 | ||
14465 | @table @code | |
14466 | @item set sdstimeout @var{nsec} | |
14467 | @kindex set sdstimeout | |
14468 | Set the timeout for SDS protocol reads to be @var{nsec} seconds. The | |
14469 | default is 2 seconds. | |
14470 | ||
14471 | @item show sdstimeout | |
14472 | @kindex show sdstimeout | |
14473 | Show the current value of the SDS timeout. | |
14474 | ||
14475 | @item sds @var{command} | |
14476 | @kindex sds@r{, a command} | |
14477 | Send the specified @var{command} string to the SDS monitor. | |
8e04817f AC |
14478 | @end table |
14479 | ||
c45da7e6 | 14480 | |
8e04817f AC |
14481 | @node PA |
14482 | @subsection HP PA Embedded | |
104c1213 JM |
14483 | |
14484 | @table @code | |
14485 | ||
8e04817f AC |
14486 | @kindex target op50n |
14487 | @item target op50n @var{dev} | |
14488 | OP50N monitor, running on an OKI HPPA board. | |
14489 | ||
14490 | @kindex target w89k | |
14491 | @item target w89k @var{dev} | |
14492 | W89K monitor, running on a Winbond HPPA board. | |
104c1213 JM |
14493 | |
14494 | @end table | |
14495 | ||
8e04817f | 14496 | @node SH |
172c2a43 | 14497 | @subsection Renesas SH |
104c1213 JM |
14498 | |
14499 | @table @code | |
14500 | ||
172c2a43 | 14501 | @kindex target hms@r{, with Renesas SH} |
8e04817f | 14502 | @item target hms @var{dev} |
172c2a43 | 14503 | A Renesas SH board attached via serial line to your host. Use special |
8e04817f AC |
14504 | commands @code{device} and @code{speed} to control the serial line and |
14505 | the communications speed used. | |
104c1213 | 14506 | |
172c2a43 | 14507 | @kindex target e7000@r{, with Renesas SH} |
8e04817f | 14508 | @item target e7000 @var{dev} |
172c2a43 | 14509 | E7000 emulator for Renesas SH. |
104c1213 | 14510 | |
8e04817f AC |
14511 | @kindex target sh3@r{, with SH} |
14512 | @kindex target sh3e@r{, with SH} | |
14513 | @item target sh3 @var{dev} | |
14514 | @item target sh3e @var{dev} | |
172c2a43 | 14515 | Renesas SH-3 and SH-3E target systems. |
104c1213 | 14516 | |
8e04817f | 14517 | @end table |
104c1213 | 14518 | |
8e04817f AC |
14519 | @node Sparclet |
14520 | @subsection Tsqware Sparclet | |
104c1213 | 14521 | |
8e04817f AC |
14522 | @cindex Sparclet |
14523 | ||
14524 | @value{GDBN} enables developers to debug tasks running on | |
14525 | Sparclet targets from a Unix host. | |
14526 | @value{GDBN} uses code that runs on | |
14527 | both the Unix host and on the Sparclet target. The program | |
14528 | @code{@value{GDBP}} is installed and executed on the Unix host. | |
104c1213 | 14529 | |
8e04817f AC |
14530 | @table @code |
14531 | @item remotetimeout @var{args} | |
14532 | @kindex remotetimeout | |
14533 | @value{GDBN} supports the option @code{remotetimeout}. | |
14534 | This option is set by the user, and @var{args} represents the number of | |
14535 | seconds @value{GDBN} waits for responses. | |
104c1213 JM |
14536 | @end table |
14537 | ||
8e04817f AC |
14538 | @cindex compiling, on Sparclet |
14539 | When compiling for debugging, include the options @samp{-g} to get debug | |
14540 | information and @samp{-Ttext} to relocate the program to where you wish to | |
14541 | load it on the target. You may also want to add the options @samp{-n} or | |
14542 | @samp{-N} in order to reduce the size of the sections. Example: | |
104c1213 | 14543 | |
474c8240 | 14544 | @smallexample |
8e04817f | 14545 | sparclet-aout-gcc prog.c -Ttext 0x12010000 -g -o prog -N |
474c8240 | 14546 | @end smallexample |
104c1213 | 14547 | |
8e04817f | 14548 | You can use @code{objdump} to verify that the addresses are what you intended: |
104c1213 | 14549 | |
474c8240 | 14550 | @smallexample |
8e04817f | 14551 | sparclet-aout-objdump --headers --syms prog |
474c8240 | 14552 | @end smallexample |
104c1213 | 14553 | |
8e04817f AC |
14554 | @cindex running, on Sparclet |
14555 | Once you have set | |
14556 | your Unix execution search path to find @value{GDBN}, you are ready to | |
14557 | run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} | |
14558 | (or @code{sparclet-aout-gdb}, depending on your installation). | |
104c1213 | 14559 | |
8e04817f AC |
14560 | @value{GDBN} comes up showing the prompt: |
14561 | ||
474c8240 | 14562 | @smallexample |
8e04817f | 14563 | (gdbslet) |
474c8240 | 14564 | @end smallexample |
104c1213 JM |
14565 | |
14566 | @menu | |
8e04817f AC |
14567 | * Sparclet File:: Setting the file to debug |
14568 | * Sparclet Connection:: Connecting to Sparclet | |
14569 | * Sparclet Download:: Sparclet download | |
14570 | * Sparclet Execution:: Running and debugging | |
104c1213 JM |
14571 | @end menu |
14572 | ||
8e04817f AC |
14573 | @node Sparclet File |
14574 | @subsubsection Setting file to debug | |
104c1213 | 14575 | |
8e04817f | 14576 | The @value{GDBN} command @code{file} lets you choose with program to debug. |
104c1213 | 14577 | |
474c8240 | 14578 | @smallexample |
8e04817f | 14579 | (gdbslet) file prog |
474c8240 | 14580 | @end smallexample |
104c1213 | 14581 | |
8e04817f AC |
14582 | @need 1000 |
14583 | @value{GDBN} then attempts to read the symbol table of @file{prog}. | |
14584 | @value{GDBN} locates | |
14585 | the file by searching the directories listed in the command search | |
14586 | path. | |
14587 | If the file was compiled with debug information (option "-g"), source | |
14588 | files will be searched as well. | |
14589 | @value{GDBN} locates | |
14590 | the source files by searching the directories listed in the directory search | |
14591 | path (@pxref{Environment, ,Your program's environment}). | |
14592 | If it fails | |
14593 | to find a file, it displays a message such as: | |
104c1213 | 14594 | |
474c8240 | 14595 | @smallexample |
8e04817f | 14596 | prog: No such file or directory. |
474c8240 | 14597 | @end smallexample |
104c1213 | 14598 | |
8e04817f AC |
14599 | When this happens, add the appropriate directories to the search paths with |
14600 | the @value{GDBN} commands @code{path} and @code{dir}, and execute the | |
14601 | @code{target} command again. | |
104c1213 | 14602 | |
8e04817f AC |
14603 | @node Sparclet Connection |
14604 | @subsubsection Connecting to Sparclet | |
104c1213 | 14605 | |
8e04817f AC |
14606 | The @value{GDBN} command @code{target} lets you connect to a Sparclet target. |
14607 | To connect to a target on serial port ``@code{ttya}'', type: | |
104c1213 | 14608 | |
474c8240 | 14609 | @smallexample |
8e04817f AC |
14610 | (gdbslet) target sparclet /dev/ttya |
14611 | Remote target sparclet connected to /dev/ttya | |
14612 | main () at ../prog.c:3 | |
474c8240 | 14613 | @end smallexample |
104c1213 | 14614 | |
8e04817f AC |
14615 | @need 750 |
14616 | @value{GDBN} displays messages like these: | |
104c1213 | 14617 | |
474c8240 | 14618 | @smallexample |
8e04817f | 14619 | Connected to ttya. |
474c8240 | 14620 | @end smallexample |
104c1213 | 14621 | |
8e04817f AC |
14622 | @node Sparclet Download |
14623 | @subsubsection Sparclet download | |
104c1213 | 14624 | |
8e04817f AC |
14625 | @cindex download to Sparclet |
14626 | Once connected to the Sparclet target, | |
14627 | you can use the @value{GDBN} | |
14628 | @code{load} command to download the file from the host to the target. | |
14629 | The file name and load offset should be given as arguments to the @code{load} | |
14630 | command. | |
14631 | Since the file format is aout, the program must be loaded to the starting | |
14632 | address. You can use @code{objdump} to find out what this value is. The load | |
14633 | offset is an offset which is added to the VMA (virtual memory address) | |
14634 | of each of the file's sections. | |
14635 | For instance, if the program | |
14636 | @file{prog} was linked to text address 0x1201000, with data at 0x12010160 | |
14637 | and bss at 0x12010170, in @value{GDBN}, type: | |
104c1213 | 14638 | |
474c8240 | 14639 | @smallexample |
8e04817f AC |
14640 | (gdbslet) load prog 0x12010000 |
14641 | Loading section .text, size 0xdb0 vma 0x12010000 | |
474c8240 | 14642 | @end smallexample |
104c1213 | 14643 | |
8e04817f AC |
14644 | If the code is loaded at a different address then what the program was linked |
14645 | to, you may need to use the @code{section} and @code{add-symbol-file} commands | |
14646 | to tell @value{GDBN} where to map the symbol table. | |
14647 | ||
14648 | @node Sparclet Execution | |
14649 | @subsubsection Running and debugging | |
14650 | ||
14651 | @cindex running and debugging Sparclet programs | |
14652 | You can now begin debugging the task using @value{GDBN}'s execution control | |
14653 | commands, @code{b}, @code{step}, @code{run}, etc. See the @value{GDBN} | |
14654 | manual for the list of commands. | |
14655 | ||
474c8240 | 14656 | @smallexample |
8e04817f AC |
14657 | (gdbslet) b main |
14658 | Breakpoint 1 at 0x12010000: file prog.c, line 3. | |
14659 | (gdbslet) run | |
14660 | Starting program: prog | |
14661 | Breakpoint 1, main (argc=1, argv=0xeffff21c) at prog.c:3 | |
14662 | 3 char *symarg = 0; | |
14663 | (gdbslet) step | |
14664 | 4 char *execarg = "hello!"; | |
14665 | (gdbslet) | |
474c8240 | 14666 | @end smallexample |
8e04817f AC |
14667 | |
14668 | @node Sparclite | |
14669 | @subsection Fujitsu Sparclite | |
104c1213 JM |
14670 | |
14671 | @table @code | |
14672 | ||
8e04817f AC |
14673 | @kindex target sparclite |
14674 | @item target sparclite @var{dev} | |
14675 | Fujitsu sparclite boards, used only for the purpose of loading. | |
14676 | You must use an additional command to debug the program. | |
14677 | For example: target remote @var{dev} using @value{GDBN} standard | |
14678 | remote protocol. | |
104c1213 JM |
14679 | |
14680 | @end table | |
14681 | ||
8e04817f AC |
14682 | @node ST2000 |
14683 | @subsection Tandem ST2000 | |
104c1213 | 14684 | |
8e04817f AC |
14685 | @value{GDBN} may be used with a Tandem ST2000 phone switch, running Tandem's |
14686 | STDBUG protocol. | |
104c1213 | 14687 | |
8e04817f AC |
14688 | To connect your ST2000 to the host system, see the manufacturer's |
14689 | manual. Once the ST2000 is physically attached, you can run: | |
104c1213 | 14690 | |
474c8240 | 14691 | @smallexample |
8e04817f | 14692 | target st2000 @var{dev} @var{speed} |
474c8240 | 14693 | @end smallexample |
104c1213 | 14694 | |
8e04817f AC |
14695 | @noindent |
14696 | to establish it as your debugging environment. @var{dev} is normally | |
14697 | the name of a serial device, such as @file{/dev/ttya}, connected to the | |
14698 | ST2000 via a serial line. You can instead specify @var{dev} as a TCP | |
14699 | connection (for example, to a serial line attached via a terminal | |
14700 | concentrator) using the syntax @code{@var{hostname}:@var{portnumber}}. | |
104c1213 | 14701 | |
8e04817f AC |
14702 | The @code{load} and @code{attach} commands are @emph{not} defined for |
14703 | this target; you must load your program into the ST2000 as you normally | |
14704 | would for standalone operation. @value{GDBN} reads debugging information | |
14705 | (such as symbols) from a separate, debugging version of the program | |
14706 | available on your host computer. | |
14707 | @c FIXME!! This is terribly vague; what little content is here is | |
14708 | @c basically hearsay. | |
104c1213 | 14709 | |
8e04817f AC |
14710 | @cindex ST2000 auxiliary commands |
14711 | These auxiliary @value{GDBN} commands are available to help you with the ST2000 | |
14712 | environment: | |
104c1213 | 14713 | |
8e04817f AC |
14714 | @table @code |
14715 | @item st2000 @var{command} | |
14716 | @kindex st2000 @var{cmd} | |
14717 | @cindex STDBUG commands (ST2000) | |
14718 | @cindex commands to STDBUG (ST2000) | |
14719 | Send a @var{command} to the STDBUG monitor. See the manufacturer's | |
14720 | manual for available commands. | |
104c1213 | 14721 | |
8e04817f AC |
14722 | @item connect |
14723 | @cindex connect (to STDBUG) | |
14724 | Connect the controlling terminal to the STDBUG command monitor. When | |
14725 | you are done interacting with STDBUG, typing either of two character | |
14726 | sequences gets you back to the @value{GDBN} command prompt: | |
14727 | @kbd{@key{RET}~.} (Return, followed by tilde and period) or | |
14728 | @kbd{@key{RET}~@key{C-d}} (Return, followed by tilde and control-D). | |
104c1213 JM |
14729 | @end table |
14730 | ||
8e04817f AC |
14731 | @node Z8000 |
14732 | @subsection Zilog Z8000 | |
104c1213 | 14733 | |
8e04817f AC |
14734 | @cindex Z8000 |
14735 | @cindex simulator, Z8000 | |
14736 | @cindex Zilog Z8000 simulator | |
104c1213 | 14737 | |
8e04817f AC |
14738 | When configured for debugging Zilog Z8000 targets, @value{GDBN} includes |
14739 | a Z8000 simulator. | |
14740 | ||
14741 | For the Z8000 family, @samp{target sim} simulates either the Z8002 (the | |
14742 | unsegmented variant of the Z8000 architecture) or the Z8001 (the | |
14743 | segmented variant). The simulator recognizes which architecture is | |
14744 | appropriate by inspecting the object code. | |
104c1213 | 14745 | |
8e04817f AC |
14746 | @table @code |
14747 | @item target sim @var{args} | |
14748 | @kindex sim | |
14749 | @kindex target sim@r{, with Z8000} | |
14750 | Debug programs on a simulated CPU. If the simulator supports setup | |
14751 | options, specify them via @var{args}. | |
104c1213 JM |
14752 | @end table |
14753 | ||
8e04817f AC |
14754 | @noindent |
14755 | After specifying this target, you can debug programs for the simulated | |
14756 | CPU in the same style as programs for your host computer; use the | |
14757 | @code{file} command to load a new program image, the @code{run} command | |
14758 | to run your program, and so on. | |
14759 | ||
14760 | As well as making available all the usual machine registers | |
14761 | (@pxref{Registers, ,Registers}), the Z8000 simulator provides three | |
14762 | additional items of information as specially named registers: | |
104c1213 JM |
14763 | |
14764 | @table @code | |
14765 | ||
8e04817f AC |
14766 | @item cycles |
14767 | Counts clock-ticks in the simulator. | |
104c1213 | 14768 | |
8e04817f AC |
14769 | @item insts |
14770 | Counts instructions run in the simulator. | |
104c1213 | 14771 | |
8e04817f AC |
14772 | @item time |
14773 | Execution time in 60ths of a second. | |
104c1213 | 14774 | |
8e04817f | 14775 | @end table |
104c1213 | 14776 | |
8e04817f AC |
14777 | You can refer to these values in @value{GDBN} expressions with the usual |
14778 | conventions; for example, @w{@samp{b fputc if $cycles>5000}} sets a | |
14779 | conditional breakpoint that suspends only after at least 5000 | |
14780 | simulated clock ticks. | |
104c1213 | 14781 | |
a64548ea EZ |
14782 | @node AVR |
14783 | @subsection Atmel AVR | |
14784 | @cindex AVR | |
14785 | ||
14786 | When configured for debugging the Atmel AVR, @value{GDBN} supports the | |
14787 | following AVR-specific commands: | |
14788 | ||
14789 | @table @code | |
14790 | @item info io_registers | |
14791 | @kindex info io_registers@r{, AVR} | |
14792 | @cindex I/O registers (Atmel AVR) | |
14793 | This command displays information about the AVR I/O registers. For | |
14794 | each register, @value{GDBN} prints its number and value. | |
14795 | @end table | |
14796 | ||
14797 | @node CRIS | |
14798 | @subsection CRIS | |
14799 | @cindex CRIS | |
14800 | ||
14801 | When configured for debugging CRIS, @value{GDBN} provides the | |
14802 | following CRIS-specific commands: | |
14803 | ||
14804 | @table @code | |
14805 | @item set cris-version @var{ver} | |
14806 | @cindex CRIS version | |
e22e55c9 OF |
14807 | Set the current CRIS version to @var{ver}, either @samp{10} or @samp{32}. |
14808 | The CRIS version affects register names and sizes. This command is useful in | |
14809 | case autodetection of the CRIS version fails. | |
a64548ea EZ |
14810 | |
14811 | @item show cris-version | |
14812 | Show the current CRIS version. | |
14813 | ||
14814 | @item set cris-dwarf2-cfi | |
14815 | @cindex DWARF-2 CFI and CRIS | |
e22e55c9 OF |
14816 | Set the usage of DWARF-2 CFI for CRIS debugging. The default is @samp{on}. |
14817 | Change to @samp{off} when using @code{gcc-cris} whose version is below | |
14818 | @code{R59}. | |
a64548ea EZ |
14819 | |
14820 | @item show cris-dwarf2-cfi | |
14821 | Show the current state of using DWARF-2 CFI. | |
e22e55c9 OF |
14822 | |
14823 | @item set cris-mode @var{mode} | |
14824 | @cindex CRIS mode | |
14825 | Set the current CRIS mode to @var{mode}. It should only be changed when | |
14826 | debugging in guru mode, in which case it should be set to | |
14827 | @samp{guru} (the default is @samp{normal}). | |
14828 | ||
14829 | @item show cris-mode | |
14830 | Show the current CRIS mode. | |
a64548ea EZ |
14831 | @end table |
14832 | ||
14833 | @node Super-H | |
14834 | @subsection Renesas Super-H | |
14835 | @cindex Super-H | |
14836 | ||
14837 | For the Renesas Super-H processor, @value{GDBN} provides these | |
14838 | commands: | |
14839 | ||
14840 | @table @code | |
14841 | @item regs | |
14842 | @kindex regs@r{, Super-H} | |
14843 | Show the values of all Super-H registers. | |
14844 | @end table | |
14845 | ||
c45da7e6 EZ |
14846 | @node WinCE |
14847 | @subsection Windows CE | |
14848 | @cindex Windows CE | |
14849 | ||
14850 | The following commands are available for Windows CE: | |
14851 | ||
14852 | @table @code | |
14853 | @item set remotedirectory @var{dir} | |
14854 | @kindex set remotedirectory | |
14855 | Tell @value{GDBN} to upload files from the named directory @var{dir}. | |
14856 | The default is @file{/gdb}, i.e.@: the root directory on the current | |
14857 | drive. | |
14858 | ||
14859 | @item show remotedirectory | |
14860 | @kindex show remotedirectory | |
14861 | Show the current value of the upload directory. | |
14862 | ||
14863 | @item set remoteupload @var{method} | |
14864 | @kindex set remoteupload | |
14865 | Set the method used to upload files to remote device. Valid values | |
14866 | for @var{method} are @samp{always}, @samp{newer}, and @samp{never}. | |
14867 | The default is @samp{newer}. | |
14868 | ||
14869 | @item show remoteupload | |
14870 | @kindex show remoteupload | |
14871 | Show the current setting of the upload method. | |
14872 | ||
14873 | @item set remoteaddhost | |
14874 | @kindex set remoteaddhost | |
14875 | Tell @value{GDBN} whether to add this host to the remote stub's | |
14876 | arguments when you debug over a network. | |
14877 | ||
14878 | @item show remoteaddhost | |
14879 | @kindex show remoteaddhost | |
14880 | Show whether to add this host to remote stub's arguments when | |
14881 | debugging over a network. | |
14882 | @end table | |
14883 | ||
a64548ea | 14884 | |
8e04817f AC |
14885 | @node Architectures |
14886 | @section Architectures | |
104c1213 | 14887 | |
8e04817f AC |
14888 | This section describes characteristics of architectures that affect |
14889 | all uses of @value{GDBN} with the architecture, both native and cross. | |
104c1213 | 14890 | |
8e04817f | 14891 | @menu |
9c16f35a | 14892 | * i386:: |
8e04817f AC |
14893 | * A29K:: |
14894 | * Alpha:: | |
14895 | * MIPS:: | |
a64548ea | 14896 | * HPPA:: HP PA architecture |
8e04817f | 14897 | @end menu |
104c1213 | 14898 | |
9c16f35a EZ |
14899 | @node i386 |
14900 | @subsection x86 Architecture-specific issues. | |
14901 | ||
14902 | @table @code | |
14903 | @item set struct-convention @var{mode} | |
14904 | @kindex set struct-convention | |
14905 | @cindex struct return convention | |
14906 | @cindex struct/union returned in registers | |
14907 | Set the convention used by the inferior to return @code{struct}s and | |
14908 | @code{union}s from functions to @var{mode}. Possible values of | |
14909 | @var{mode} are @code{"pcc"}, @code{"reg"}, and @code{"default"} (the | |
14910 | default). @code{"default"} or @code{"pcc"} means that @code{struct}s | |
14911 | are returned on the stack, while @code{"reg"} means that a | |
14912 | @code{struct} or a @code{union} whose size is 1, 2, 4, or 8 bytes will | |
14913 | be returned in a register. | |
14914 | ||
14915 | @item show struct-convention | |
14916 | @kindex show struct-convention | |
14917 | Show the current setting of the convention to return @code{struct}s | |
14918 | from functions. | |
14919 | @end table | |
14920 | ||
8e04817f AC |
14921 | @node A29K |
14922 | @subsection A29K | |
104c1213 JM |
14923 | |
14924 | @table @code | |
104c1213 | 14925 | |
8e04817f AC |
14926 | @kindex set rstack_high_address |
14927 | @cindex AMD 29K register stack | |
14928 | @cindex register stack, AMD29K | |
14929 | @item set rstack_high_address @var{address} | |
14930 | On AMD 29000 family processors, registers are saved in a separate | |
14931 | @dfn{register stack}. There is no way for @value{GDBN} to determine the | |
14932 | extent of this stack. Normally, @value{GDBN} just assumes that the | |
14933 | stack is ``large enough''. This may result in @value{GDBN} referencing | |
14934 | memory locations that do not exist. If necessary, you can get around | |
14935 | this problem by specifying the ending address of the register stack with | |
14936 | the @code{set rstack_high_address} command. The argument should be an | |
14937 | address, which you probably want to precede with @samp{0x} to specify in | |
14938 | hexadecimal. | |
104c1213 | 14939 | |
8e04817f AC |
14940 | @kindex show rstack_high_address |
14941 | @item show rstack_high_address | |
14942 | Display the current limit of the register stack, on AMD 29000 family | |
14943 | processors. | |
104c1213 | 14944 | |
8e04817f | 14945 | @end table |
104c1213 | 14946 | |
8e04817f AC |
14947 | @node Alpha |
14948 | @subsection Alpha | |
104c1213 | 14949 | |
8e04817f | 14950 | See the following section. |
104c1213 | 14951 | |
8e04817f AC |
14952 | @node MIPS |
14953 | @subsection MIPS | |
104c1213 | 14954 | |
8e04817f AC |
14955 | @cindex stack on Alpha |
14956 | @cindex stack on MIPS | |
14957 | @cindex Alpha stack | |
14958 | @cindex MIPS stack | |
14959 | Alpha- and MIPS-based computers use an unusual stack frame, which | |
14960 | sometimes requires @value{GDBN} to search backward in the object code to | |
14961 | find the beginning of a function. | |
104c1213 | 14962 | |
8e04817f AC |
14963 | @cindex response time, MIPS debugging |
14964 | To improve response time (especially for embedded applications, where | |
14965 | @value{GDBN} may be restricted to a slow serial line for this search) | |
14966 | you may want to limit the size of this search, using one of these | |
14967 | commands: | |
104c1213 | 14968 | |
8e04817f AC |
14969 | @table @code |
14970 | @cindex @code{heuristic-fence-post} (Alpha, MIPS) | |
14971 | @item set heuristic-fence-post @var{limit} | |
14972 | Restrict @value{GDBN} to examining at most @var{limit} bytes in its | |
14973 | search for the beginning of a function. A value of @var{0} (the | |
14974 | default) means there is no limit. However, except for @var{0}, the | |
14975 | larger the limit the more bytes @code{heuristic-fence-post} must search | |
e2f4edfd EZ |
14976 | and therefore the longer it takes to run. You should only need to use |
14977 | this command when debugging a stripped executable. | |
104c1213 | 14978 | |
8e04817f AC |
14979 | @item show heuristic-fence-post |
14980 | Display the current limit. | |
14981 | @end table | |
104c1213 JM |
14982 | |
14983 | @noindent | |
8e04817f AC |
14984 | These commands are available @emph{only} when @value{GDBN} is configured |
14985 | for debugging programs on Alpha or MIPS processors. | |
104c1213 | 14986 | |
a64548ea EZ |
14987 | Several MIPS-specific commands are available when debugging MIPS |
14988 | programs: | |
14989 | ||
14990 | @table @code | |
14991 | @item set mips saved-gpreg-size @var{size} | |
14992 | @kindex set mips saved-gpreg-size | |
14993 | @cindex MIPS GP register size on stack | |
14994 | Set the size of MIPS general-purpose registers saved on the stack. | |
14995 | The argument @var{size} can be one of the following: | |
14996 | ||
14997 | @table @samp | |
14998 | @item 32 | |
14999 | 32-bit GP registers | |
15000 | @item 64 | |
15001 | 64-bit GP registers | |
15002 | @item auto | |
15003 | Use the target's default setting or autodetect the saved size from the | |
15004 | information contained in the executable. This is the default | |
15005 | @end table | |
15006 | ||
15007 | @item show mips saved-gpreg-size | |
15008 | @kindex show mips saved-gpreg-size | |
15009 | Show the current size of MIPS GP registers on the stack. | |
15010 | ||
15011 | @item set mips stack-arg-size @var{size} | |
15012 | @kindex set mips stack-arg-size | |
15013 | @cindex MIPS stack space for arguments | |
15014 | Set the amount of stack space reserved for arguments to functions. | |
15015 | The argument can be one of @code{"32"}, @code{"64"} or @code{"auto"} | |
15016 | (the default). | |
15017 | ||
15018 | @item set mips abi @var{arg} | |
15019 | @kindex set mips abi | |
15020 | @cindex set ABI for MIPS | |
15021 | Tell @value{GDBN} which MIPS ABI is used by the inferior. Possible | |
15022 | values of @var{arg} are: | |
15023 | ||
15024 | @table @samp | |
15025 | @item auto | |
15026 | The default ABI associated with the current binary (this is the | |
15027 | default). | |
15028 | @item o32 | |
15029 | @item o64 | |
15030 | @item n32 | |
15031 | @item n64 | |
15032 | @item eabi32 | |
15033 | @item eabi64 | |
15034 | @item auto | |
15035 | @end table | |
15036 | ||
15037 | @item show mips abi | |
15038 | @kindex show mips abi | |
15039 | Show the MIPS ABI used by @value{GDBN} to debug the inferior. | |
15040 | ||
15041 | @item set mipsfpu | |
15042 | @itemx show mipsfpu | |
15043 | @xref{MIPS Embedded, set mipsfpu}. | |
15044 | ||
15045 | @item set mips mask-address @var{arg} | |
15046 | @kindex set mips mask-address | |
15047 | @cindex MIPS addresses, masking | |
15048 | This command determines whether the most-significant 32 bits of 64-bit | |
15049 | MIPS addresses are masked off. The argument @var{arg} can be | |
15050 | @samp{on}, @samp{off}, or @samp{auto}. The latter is the default | |
15051 | setting, which lets @value{GDBN} determine the correct value. | |
15052 | ||
15053 | @item show mips mask-address | |
15054 | @kindex show mips mask-address | |
15055 | Show whether the upper 32 bits of MIPS addresses are masked off or | |
15056 | not. | |
15057 | ||
15058 | @item set remote-mips64-transfers-32bit-regs | |
15059 | @kindex set remote-mips64-transfers-32bit-regs | |
15060 | This command controls compatibility with 64-bit MIPS targets that | |
15061 | transfer data in 32-bit quantities. If you have an old MIPS 64 target | |
15062 | that transfers 32 bits for some registers, like @sc{sr} and @sc{fsr}, | |
15063 | and 64 bits for other registers, set this option to @samp{on}. | |
15064 | ||
15065 | @item show remote-mips64-transfers-32bit-regs | |
15066 | @kindex show remote-mips64-transfers-32bit-regs | |
15067 | Show the current setting of compatibility with older MIPS 64 targets. | |
15068 | ||
15069 | @item set debug mips | |
15070 | @kindex set debug mips | |
15071 | This command turns on and off debugging messages for the MIPS-specific | |
15072 | target code in @value{GDBN}. | |
15073 | ||
15074 | @item show debug mips | |
15075 | @kindex show debug mips | |
15076 | Show the current setting of MIPS debugging messages. | |
15077 | @end table | |
15078 | ||
15079 | ||
15080 | @node HPPA | |
15081 | @subsection HPPA | |
15082 | @cindex HPPA support | |
15083 | ||
15084 | When @value{GDBN} is debugging te HP PA architecture, it provides the | |
15085 | following special commands: | |
15086 | ||
15087 | @table @code | |
15088 | @item set debug hppa | |
15089 | @kindex set debug hppa | |
15090 | THis command determines whether HPPA architecture specific debugging | |
15091 | messages are to be displayed. | |
15092 | ||
15093 | @item show debug hppa | |
15094 | Show whether HPPA debugging messages are displayed. | |
15095 | ||
15096 | @item maint print unwind @var{address} | |
15097 | @kindex maint print unwind@r{, HPPA} | |
15098 | This command displays the contents of the unwind table entry at the | |
15099 | given @var{address}. | |
15100 | ||
15101 | @end table | |
15102 | ||
104c1213 | 15103 | |
8e04817f AC |
15104 | @node Controlling GDB |
15105 | @chapter Controlling @value{GDBN} | |
15106 | ||
15107 | You can alter the way @value{GDBN} interacts with you by using the | |
15108 | @code{set} command. For commands controlling how @value{GDBN} displays | |
15109 | data, see @ref{Print Settings, ,Print settings}. Other settings are | |
15110 | described here. | |
15111 | ||
15112 | @menu | |
15113 | * Prompt:: Prompt | |
15114 | * Editing:: Command editing | |
d620b259 | 15115 | * Command History:: Command history |
8e04817f AC |
15116 | * Screen Size:: Screen size |
15117 | * Numbers:: Numbers | |
1e698235 | 15118 | * ABI:: Configuring the current ABI |
8e04817f AC |
15119 | * Messages/Warnings:: Optional warnings and messages |
15120 | * Debugging Output:: Optional messages about internal happenings | |
15121 | @end menu | |
15122 | ||
15123 | @node Prompt | |
15124 | @section Prompt | |
104c1213 | 15125 | |
8e04817f | 15126 | @cindex prompt |
104c1213 | 15127 | |
8e04817f AC |
15128 | @value{GDBN} indicates its readiness to read a command by printing a string |
15129 | called the @dfn{prompt}. This string is normally @samp{(@value{GDBP})}. You | |
15130 | can change the prompt string with the @code{set prompt} command. For | |
15131 | instance, when debugging @value{GDBN} with @value{GDBN}, it is useful to change | |
15132 | the prompt in one of the @value{GDBN} sessions so that you can always tell | |
15133 | which one you are talking to. | |
104c1213 | 15134 | |
8e04817f AC |
15135 | @emph{Note:} @code{set prompt} does not add a space for you after the |
15136 | prompt you set. This allows you to set a prompt which ends in a space | |
15137 | or a prompt that does not. | |
104c1213 | 15138 | |
8e04817f AC |
15139 | @table @code |
15140 | @kindex set prompt | |
15141 | @item set prompt @var{newprompt} | |
15142 | Directs @value{GDBN} to use @var{newprompt} as its prompt string henceforth. | |
104c1213 | 15143 | |
8e04817f AC |
15144 | @kindex show prompt |
15145 | @item show prompt | |
15146 | Prints a line of the form: @samp{Gdb's prompt is: @var{your-prompt}} | |
104c1213 JM |
15147 | @end table |
15148 | ||
8e04817f AC |
15149 | @node Editing |
15150 | @section Command editing | |
15151 | @cindex readline | |
15152 | @cindex command line editing | |
104c1213 | 15153 | |
703663ab | 15154 | @value{GDBN} reads its input commands via the @dfn{Readline} interface. This |
8e04817f AC |
15155 | @sc{gnu} library provides consistent behavior for programs which provide a |
15156 | command line interface to the user. Advantages are @sc{gnu} Emacs-style | |
15157 | or @dfn{vi}-style inline editing of commands, @code{csh}-like history | |
15158 | substitution, and a storage and recall of command history across | |
15159 | debugging sessions. | |
104c1213 | 15160 | |
8e04817f AC |
15161 | You may control the behavior of command line editing in @value{GDBN} with the |
15162 | command @code{set}. | |
104c1213 | 15163 | |
8e04817f AC |
15164 | @table @code |
15165 | @kindex set editing | |
15166 | @cindex editing | |
15167 | @item set editing | |
15168 | @itemx set editing on | |
15169 | Enable command line editing (enabled by default). | |
104c1213 | 15170 | |
8e04817f AC |
15171 | @item set editing off |
15172 | Disable command line editing. | |
104c1213 | 15173 | |
8e04817f AC |
15174 | @kindex show editing |
15175 | @item show editing | |
15176 | Show whether command line editing is enabled. | |
104c1213 JM |
15177 | @end table |
15178 | ||
703663ab EZ |
15179 | @xref{Command Line Editing}, for more details about the Readline |
15180 | interface. Users unfamiliar with @sc{gnu} Emacs or @code{vi} are | |
15181 | encouraged to read that chapter. | |
15182 | ||
d620b259 | 15183 | @node Command History |
8e04817f | 15184 | @section Command history |
703663ab | 15185 | @cindex command history |
8e04817f AC |
15186 | |
15187 | @value{GDBN} can keep track of the commands you type during your | |
15188 | debugging sessions, so that you can be certain of precisely what | |
15189 | happened. Use these commands to manage the @value{GDBN} command | |
15190 | history facility. | |
104c1213 | 15191 | |
703663ab EZ |
15192 | @value{GDBN} uses the @sc{gnu} History library, a part of the Readline |
15193 | package, to provide the history facility. @xref{Using History | |
15194 | Interactively}, for the detailed description of the History library. | |
15195 | ||
d620b259 NR |
15196 | To issue a command to @value{GDBN} without affecting certain aspects of |
15197 | the state which is seen by users, prefix it with @samp{server }. This | |
15198 | means that this command will not affect the command history, nor will it | |
15199 | affect @value{GDBN}'s notion of which command to repeat if @key{RET} is | |
15200 | pressed on a line by itself. | |
15201 | ||
15202 | @cindex @code{server}, command prefix | |
15203 | The server prefix does not affect the recording of values into the value | |
15204 | history; to print a value without recording it into the value history, | |
15205 | use the @code{output} command instead of the @code{print} command. | |
15206 | ||
703663ab EZ |
15207 | Here is the description of @value{GDBN} commands related to command |
15208 | history. | |
15209 | ||
104c1213 | 15210 | @table @code |
8e04817f AC |
15211 | @cindex history substitution |
15212 | @cindex history file | |
15213 | @kindex set history filename | |
4644b6e3 | 15214 | @cindex @env{GDBHISTFILE}, environment variable |
8e04817f AC |
15215 | @item set history filename @var{fname} |
15216 | Set the name of the @value{GDBN} command history file to @var{fname}. | |
15217 | This is the file where @value{GDBN} reads an initial command history | |
15218 | list, and where it writes the command history from this session when it | |
15219 | exits. You can access this list through history expansion or through | |
15220 | the history command editing characters listed below. This file defaults | |
15221 | to the value of the environment variable @code{GDBHISTFILE}, or to | |
15222 | @file{./.gdb_history} (@file{./_gdb_history} on MS-DOS) if this variable | |
15223 | is not set. | |
104c1213 | 15224 | |
9c16f35a EZ |
15225 | @cindex save command history |
15226 | @kindex set history save | |
8e04817f AC |
15227 | @item set history save |
15228 | @itemx set history save on | |
15229 | Record command history in a file, whose name may be specified with the | |
15230 | @code{set history filename} command. By default, this option is disabled. | |
104c1213 | 15231 | |
8e04817f AC |
15232 | @item set history save off |
15233 | Stop recording command history in a file. | |
104c1213 | 15234 | |
8e04817f | 15235 | @cindex history size |
9c16f35a | 15236 | @kindex set history size |
6fc08d32 | 15237 | @cindex @env{HISTSIZE}, environment variable |
8e04817f AC |
15238 | @item set history size @var{size} |
15239 | Set the number of commands which @value{GDBN} keeps in its history list. | |
15240 | This defaults to the value of the environment variable | |
15241 | @code{HISTSIZE}, or to 256 if this variable is not set. | |
104c1213 JM |
15242 | @end table |
15243 | ||
8e04817f | 15244 | History expansion assigns special meaning to the character @kbd{!}. |
703663ab | 15245 | @xref{Event Designators}, for more details. |
8e04817f | 15246 | |
703663ab | 15247 | @cindex history expansion, turn on/off |
8e04817f AC |
15248 | Since @kbd{!} is also the logical not operator in C, history expansion |
15249 | is off by default. If you decide to enable history expansion with the | |
15250 | @code{set history expansion on} command, you may sometimes need to | |
15251 | follow @kbd{!} (when it is used as logical not, in an expression) with | |
15252 | a space or a tab to prevent it from being expanded. The readline | |
15253 | history facilities do not attempt substitution on the strings | |
15254 | @kbd{!=} and @kbd{!(}, even when history expansion is enabled. | |
15255 | ||
15256 | The commands to control history expansion are: | |
104c1213 JM |
15257 | |
15258 | @table @code | |
8e04817f AC |
15259 | @item set history expansion on |
15260 | @itemx set history expansion | |
703663ab | 15261 | @kindex set history expansion |
8e04817f | 15262 | Enable history expansion. History expansion is off by default. |
104c1213 | 15263 | |
8e04817f AC |
15264 | @item set history expansion off |
15265 | Disable history expansion. | |
104c1213 | 15266 | |
8e04817f AC |
15267 | @c @group |
15268 | @kindex show history | |
15269 | @item show history | |
15270 | @itemx show history filename | |
15271 | @itemx show history save | |
15272 | @itemx show history size | |
15273 | @itemx show history expansion | |
15274 | These commands display the state of the @value{GDBN} history parameters. | |
15275 | @code{show history} by itself displays all four states. | |
15276 | @c @end group | |
15277 | @end table | |
15278 | ||
15279 | @table @code | |
9c16f35a EZ |
15280 | @kindex show commands |
15281 | @cindex show last commands | |
15282 | @cindex display command history | |
8e04817f AC |
15283 | @item show commands |
15284 | Display the last ten commands in the command history. | |
104c1213 | 15285 | |
8e04817f AC |
15286 | @item show commands @var{n} |
15287 | Print ten commands centered on command number @var{n}. | |
15288 | ||
15289 | @item show commands + | |
15290 | Print ten commands just after the commands last printed. | |
104c1213 JM |
15291 | @end table |
15292 | ||
8e04817f AC |
15293 | @node Screen Size |
15294 | @section Screen size | |
15295 | @cindex size of screen | |
15296 | @cindex pauses in output | |
104c1213 | 15297 | |
8e04817f AC |
15298 | Certain commands to @value{GDBN} may produce large amounts of |
15299 | information output to the screen. To help you read all of it, | |
15300 | @value{GDBN} pauses and asks you for input at the end of each page of | |
15301 | output. Type @key{RET} when you want to continue the output, or @kbd{q} | |
15302 | to discard the remaining output. Also, the screen width setting | |
15303 | determines when to wrap lines of output. Depending on what is being | |
15304 | printed, @value{GDBN} tries to break the line at a readable place, | |
15305 | rather than simply letting it overflow onto the following line. | |
15306 | ||
15307 | Normally @value{GDBN} knows the size of the screen from the terminal | |
15308 | driver software. For example, on Unix @value{GDBN} uses the termcap data base | |
15309 | together with the value of the @code{TERM} environment variable and the | |
15310 | @code{stty rows} and @code{stty cols} settings. If this is not correct, | |
15311 | you can override it with the @code{set height} and @code{set | |
15312 | width} commands: | |
15313 | ||
15314 | @table @code | |
15315 | @kindex set height | |
15316 | @kindex set width | |
15317 | @kindex show width | |
15318 | @kindex show height | |
15319 | @item set height @var{lpp} | |
15320 | @itemx show height | |
15321 | @itemx set width @var{cpl} | |
15322 | @itemx show width | |
15323 | These @code{set} commands specify a screen height of @var{lpp} lines and | |
15324 | a screen width of @var{cpl} characters. The associated @code{show} | |
15325 | commands display the current settings. | |
104c1213 | 15326 | |
8e04817f AC |
15327 | If you specify a height of zero lines, @value{GDBN} does not pause during |
15328 | output no matter how long the output is. This is useful if output is to a | |
15329 | file or to an editor buffer. | |
104c1213 | 15330 | |
8e04817f AC |
15331 | Likewise, you can specify @samp{set width 0} to prevent @value{GDBN} |
15332 | from wrapping its output. | |
9c16f35a EZ |
15333 | |
15334 | @item set pagination on | |
15335 | @itemx set pagination off | |
15336 | @kindex set pagination | |
15337 | Turn the output pagination on or off; the default is on. Turning | |
15338 | pagination off is the alternative to @code{set height 0}. | |
15339 | ||
15340 | @item show pagination | |
15341 | @kindex show pagination | |
15342 | Show the current pagination mode. | |
104c1213 JM |
15343 | @end table |
15344 | ||
8e04817f AC |
15345 | @node Numbers |
15346 | @section Numbers | |
15347 | @cindex number representation | |
15348 | @cindex entering numbers | |
104c1213 | 15349 | |
8e04817f AC |
15350 | You can always enter numbers in octal, decimal, or hexadecimal in |
15351 | @value{GDBN} by the usual conventions: octal numbers begin with | |
15352 | @samp{0}, decimal numbers end with @samp{.}, and hexadecimal numbers | |
eb2dae08 EZ |
15353 | begin with @samp{0x}. Numbers that neither begin with @samp{0} or |
15354 | @samp{0x}, nor end with a @samp{.} are, by default, entered in base | |
15355 | 10; likewise, the default display for numbers---when no particular | |
15356 | format is specified---is base 10. You can change the default base for | |
15357 | both input and output with the commands described below. | |
104c1213 | 15358 | |
8e04817f AC |
15359 | @table @code |
15360 | @kindex set input-radix | |
15361 | @item set input-radix @var{base} | |
15362 | Set the default base for numeric input. Supported choices | |
15363 | for @var{base} are decimal 8, 10, or 16. @var{base} must itself be | |
eb2dae08 | 15364 | specified either unambiguously or using the current input radix; for |
8e04817f | 15365 | example, any of |
104c1213 | 15366 | |
8e04817f | 15367 | @smallexample |
9c16f35a EZ |
15368 | set input-radix 012 |
15369 | set input-radix 10. | |
15370 | set input-radix 0xa | |
8e04817f | 15371 | @end smallexample |
104c1213 | 15372 | |
8e04817f | 15373 | @noindent |
9c16f35a | 15374 | sets the input base to decimal. On the other hand, @samp{set input-radix 10} |
eb2dae08 EZ |
15375 | leaves the input radix unchanged, no matter what it was, since |
15376 | @samp{10}, being without any leading or trailing signs of its base, is | |
15377 | interpreted in the current radix. Thus, if the current radix is 16, | |
15378 | @samp{10} is interpreted in hex, i.e.@: as 16 decimal, which doesn't | |
15379 | change the radix. | |
104c1213 | 15380 | |
8e04817f AC |
15381 | @kindex set output-radix |
15382 | @item set output-radix @var{base} | |
15383 | Set the default base for numeric display. Supported choices | |
15384 | for @var{base} are decimal 8, 10, or 16. @var{base} must itself be | |
eb2dae08 | 15385 | specified either unambiguously or using the current input radix. |
104c1213 | 15386 | |
8e04817f AC |
15387 | @kindex show input-radix |
15388 | @item show input-radix | |
15389 | Display the current default base for numeric input. | |
104c1213 | 15390 | |
8e04817f AC |
15391 | @kindex show output-radix |
15392 | @item show output-radix | |
15393 | Display the current default base for numeric display. | |
9c16f35a EZ |
15394 | |
15395 | @item set radix @r{[}@var{base}@r{]} | |
15396 | @itemx show radix | |
15397 | @kindex set radix | |
15398 | @kindex show radix | |
15399 | These commands set and show the default base for both input and output | |
15400 | of numbers. @code{set radix} sets the radix of input and output to | |
15401 | the same base; without an argument, it resets the radix back to its | |
15402 | default value of 10. | |
15403 | ||
8e04817f | 15404 | @end table |
104c1213 | 15405 | |
1e698235 DJ |
15406 | @node ABI |
15407 | @section Configuring the current ABI | |
15408 | ||
15409 | @value{GDBN} can determine the @dfn{ABI} (Application Binary Interface) of your | |
15410 | application automatically. However, sometimes you need to override its | |
15411 | conclusions. Use these commands to manage @value{GDBN}'s view of the | |
15412 | current ABI. | |
15413 | ||
98b45e30 DJ |
15414 | @cindex OS ABI |
15415 | @kindex set osabi | |
b4e9345d | 15416 | @kindex show osabi |
98b45e30 DJ |
15417 | |
15418 | One @value{GDBN} configuration can debug binaries for multiple operating | |
b383017d | 15419 | system targets, either via remote debugging or native emulation. |
98b45e30 DJ |
15420 | @value{GDBN} will autodetect the @dfn{OS ABI} (Operating System ABI) in use, |
15421 | but you can override its conclusion using the @code{set osabi} command. | |
15422 | One example where this is useful is in debugging of binaries which use | |
15423 | an alternate C library (e.g.@: @sc{uClibc} for @sc{gnu}/Linux) which does | |
15424 | not have the same identifying marks that the standard C library for your | |
15425 | platform provides. | |
15426 | ||
15427 | @table @code | |
15428 | @item show osabi | |
15429 | Show the OS ABI currently in use. | |
15430 | ||
15431 | @item set osabi | |
15432 | With no argument, show the list of registered available OS ABI's. | |
15433 | ||
15434 | @item set osabi @var{abi} | |
15435 | Set the current OS ABI to @var{abi}. | |
15436 | @end table | |
15437 | ||
1e698235 | 15438 | @cindex float promotion |
1e698235 DJ |
15439 | |
15440 | Generally, the way that an argument of type @code{float} is passed to a | |
15441 | function depends on whether the function is prototyped. For a prototyped | |
15442 | (i.e.@: ANSI/ISO style) function, @code{float} arguments are passed unchanged, | |
15443 | according to the architecture's convention for @code{float}. For unprototyped | |
15444 | (i.e.@: K&R style) functions, @code{float} arguments are first promoted to type | |
15445 | @code{double} and then passed. | |
15446 | ||
15447 | Unfortunately, some forms of debug information do not reliably indicate whether | |
15448 | a function is prototyped. If @value{GDBN} calls a function that is not marked | |
15449 | as prototyped, it consults @kbd{set coerce-float-to-double}. | |
15450 | ||
15451 | @table @code | |
a8f24a35 | 15452 | @kindex set coerce-float-to-double |
1e698235 DJ |
15453 | @item set coerce-float-to-double |
15454 | @itemx set coerce-float-to-double on | |
15455 | Arguments of type @code{float} will be promoted to @code{double} when passed | |
15456 | to an unprototyped function. This is the default setting. | |
15457 | ||
15458 | @item set coerce-float-to-double off | |
15459 | Arguments of type @code{float} will be passed directly to unprototyped | |
15460 | functions. | |
9c16f35a EZ |
15461 | |
15462 | @kindex show coerce-float-to-double | |
15463 | @item show coerce-float-to-double | |
15464 | Show the current setting of promoting @code{float} to @code{double}. | |
1e698235 DJ |
15465 | @end table |
15466 | ||
f1212245 DJ |
15467 | @kindex set cp-abi |
15468 | @kindex show cp-abi | |
15469 | @value{GDBN} needs to know the ABI used for your program's C@t{++} | |
15470 | objects. The correct C@t{++} ABI depends on which C@t{++} compiler was | |
15471 | used to build your application. @value{GDBN} only fully supports | |
15472 | programs with a single C@t{++} ABI; if your program contains code using | |
15473 | multiple C@t{++} ABI's or if @value{GDBN} can not identify your | |
15474 | program's ABI correctly, you can tell @value{GDBN} which ABI to use. | |
15475 | Currently supported ABI's include ``gnu-v2'', for @code{g++} versions | |
15476 | before 3.0, ``gnu-v3'', for @code{g++} versions 3.0 and later, and | |
15477 | ``hpaCC'' for the HP ANSI C@t{++} compiler. Other C@t{++} compilers may | |
15478 | use the ``gnu-v2'' or ``gnu-v3'' ABI's as well. The default setting is | |
15479 | ``auto''. | |
15480 | ||
15481 | @table @code | |
15482 | @item show cp-abi | |
15483 | Show the C@t{++} ABI currently in use. | |
15484 | ||
15485 | @item set cp-abi | |
15486 | With no argument, show the list of supported C@t{++} ABI's. | |
15487 | ||
15488 | @item set cp-abi @var{abi} | |
15489 | @itemx set cp-abi auto | |
15490 | Set the current C@t{++} ABI to @var{abi}, or return to automatic detection. | |
15491 | @end table | |
15492 | ||
8e04817f AC |
15493 | @node Messages/Warnings |
15494 | @section Optional warnings and messages | |
104c1213 | 15495 | |
9c16f35a EZ |
15496 | @cindex verbose operation |
15497 | @cindex optional warnings | |
8e04817f AC |
15498 | By default, @value{GDBN} is silent about its inner workings. If you are |
15499 | running on a slow machine, you may want to use the @code{set verbose} | |
15500 | command. This makes @value{GDBN} tell you when it does a lengthy | |
15501 | internal operation, so you will not think it has crashed. | |
104c1213 | 15502 | |
8e04817f AC |
15503 | Currently, the messages controlled by @code{set verbose} are those |
15504 | which announce that the symbol table for a source file is being read; | |
15505 | see @code{symbol-file} in @ref{Files, ,Commands to specify files}. | |
104c1213 | 15506 | |
8e04817f AC |
15507 | @table @code |
15508 | @kindex set verbose | |
15509 | @item set verbose on | |
15510 | Enables @value{GDBN} output of certain informational messages. | |
104c1213 | 15511 | |
8e04817f AC |
15512 | @item set verbose off |
15513 | Disables @value{GDBN} output of certain informational messages. | |
104c1213 | 15514 | |
8e04817f AC |
15515 | @kindex show verbose |
15516 | @item show verbose | |
15517 | Displays whether @code{set verbose} is on or off. | |
15518 | @end table | |
104c1213 | 15519 | |
8e04817f AC |
15520 | By default, if @value{GDBN} encounters bugs in the symbol table of an |
15521 | object file, it is silent; but if you are debugging a compiler, you may | |
15522 | find this information useful (@pxref{Symbol Errors, ,Errors reading | |
15523 | symbol files}). | |
104c1213 | 15524 | |
8e04817f | 15525 | @table @code |
104c1213 | 15526 | |
8e04817f AC |
15527 | @kindex set complaints |
15528 | @item set complaints @var{limit} | |
15529 | Permits @value{GDBN} to output @var{limit} complaints about each type of | |
15530 | unusual symbols before becoming silent about the problem. Set | |
15531 | @var{limit} to zero to suppress all complaints; set it to a large number | |
15532 | to prevent complaints from being suppressed. | |
104c1213 | 15533 | |
8e04817f AC |
15534 | @kindex show complaints |
15535 | @item show complaints | |
15536 | Displays how many symbol complaints @value{GDBN} is permitted to produce. | |
104c1213 | 15537 | |
8e04817f | 15538 | @end table |
104c1213 | 15539 | |
8e04817f AC |
15540 | By default, @value{GDBN} is cautious, and asks what sometimes seems to be a |
15541 | lot of stupid questions to confirm certain commands. For example, if | |
15542 | you try to run a program which is already running: | |
104c1213 | 15543 | |
474c8240 | 15544 | @smallexample |
8e04817f AC |
15545 | (@value{GDBP}) run |
15546 | The program being debugged has been started already. | |
15547 | Start it from the beginning? (y or n) | |
474c8240 | 15548 | @end smallexample |
104c1213 | 15549 | |
8e04817f AC |
15550 | If you are willing to unflinchingly face the consequences of your own |
15551 | commands, you can disable this ``feature'': | |
104c1213 | 15552 | |
8e04817f | 15553 | @table @code |
104c1213 | 15554 | |
8e04817f AC |
15555 | @kindex set confirm |
15556 | @cindex flinching | |
15557 | @cindex confirmation | |
15558 | @cindex stupid questions | |
15559 | @item set confirm off | |
15560 | Disables confirmation requests. | |
104c1213 | 15561 | |
8e04817f AC |
15562 | @item set confirm on |
15563 | Enables confirmation requests (the default). | |
104c1213 | 15564 | |
8e04817f AC |
15565 | @kindex show confirm |
15566 | @item show confirm | |
15567 | Displays state of confirmation requests. | |
15568 | ||
15569 | @end table | |
104c1213 | 15570 | |
8e04817f AC |
15571 | @node Debugging Output |
15572 | @section Optional messages about internal happenings | |
4644b6e3 EZ |
15573 | @cindex optional debugging messages |
15574 | ||
da316a69 EZ |
15575 | @value{GDBN} has commands that enable optional debugging messages from |
15576 | various @value{GDBN} subsystems; normally these commands are of | |
15577 | interest to @value{GDBN} maintainers, or when reporting a bug. This | |
15578 | section documents those commands. | |
15579 | ||
104c1213 | 15580 | @table @code |
a8f24a35 EZ |
15581 | @kindex set exec-done-display |
15582 | @item set exec-done-display | |
15583 | Turns on or off the notification of asynchronous commands' | |
15584 | completion. When on, @value{GDBN} will print a message when an | |
15585 | asynchronous command finishes its execution. The default is off. | |
15586 | @kindex show exec-done-display | |
15587 | @item show exec-done-display | |
15588 | Displays the current setting of asynchronous command completion | |
15589 | notification. | |
4644b6e3 EZ |
15590 | @kindex set debug |
15591 | @cindex gdbarch debugging info | |
a8f24a35 | 15592 | @cindex architecture debugging info |
8e04817f | 15593 | @item set debug arch |
a8f24a35 | 15594 | Turns on or off display of gdbarch debugging info. The default is off |
4644b6e3 | 15595 | @kindex show debug |
8e04817f AC |
15596 | @item show debug arch |
15597 | Displays the current state of displaying gdbarch debugging info. | |
721c2651 EZ |
15598 | @item set debug aix-thread |
15599 | @cindex AIX threads | |
15600 | Display debugging messages about inner workings of the AIX thread | |
15601 | module. | |
15602 | @item show debug aix-thread | |
15603 | Show the current state of AIX thread debugging info display. | |
8e04817f | 15604 | @item set debug event |
4644b6e3 | 15605 | @cindex event debugging info |
a8f24a35 | 15606 | Turns on or off display of @value{GDBN} event debugging info. The |
8e04817f | 15607 | default is off. |
8e04817f AC |
15608 | @item show debug event |
15609 | Displays the current state of displaying @value{GDBN} event debugging | |
15610 | info. | |
8e04817f | 15611 | @item set debug expression |
4644b6e3 | 15612 | @cindex expression debugging info |
721c2651 EZ |
15613 | Turns on or off display of debugging info about @value{GDBN} |
15614 | expression parsing. The default is off. | |
8e04817f | 15615 | @item show debug expression |
721c2651 EZ |
15616 | Displays the current state of displaying debugging info about |
15617 | @value{GDBN} expression parsing. | |
7453dc06 | 15618 | @item set debug frame |
4644b6e3 | 15619 | @cindex frame debugging info |
7453dc06 AC |
15620 | Turns on or off display of @value{GDBN} frame debugging info. The |
15621 | default is off. | |
7453dc06 AC |
15622 | @item show debug frame |
15623 | Displays the current state of displaying @value{GDBN} frame debugging | |
15624 | info. | |
30e91e0b RC |
15625 | @item set debug infrun |
15626 | @cindex inferior debugging info | |
15627 | Turns on or off display of @value{GDBN} debugging info for running the inferior. | |
15628 | The default is off. @file{infrun.c} contains GDB's runtime state machine used | |
15629 | for implementing operations such as single-stepping the inferior. | |
15630 | @item show debug infrun | |
15631 | Displays the current state of @value{GDBN} inferior debugging. | |
da316a69 EZ |
15632 | @item set debug lin-lwp |
15633 | @cindex @sc{gnu}/Linux LWP debug messages | |
15634 | @cindex Linux lightweight processes | |
721c2651 | 15635 | Turns on or off debugging messages from the Linux LWP debug support. |
da316a69 EZ |
15636 | @item show debug lin-lwp |
15637 | Show the current state of Linux LWP debugging messages. | |
2b4855ab | 15638 | @item set debug observer |
4644b6e3 | 15639 | @cindex observer debugging info |
2b4855ab AC |
15640 | Turns on or off display of @value{GDBN} observer debugging. This |
15641 | includes info such as the notification of observable events. | |
2b4855ab AC |
15642 | @item show debug observer |
15643 | Displays the current state of observer debugging. | |
8e04817f | 15644 | @item set debug overload |
4644b6e3 | 15645 | @cindex C@t{++} overload debugging info |
8e04817f AC |
15646 | Turns on or off display of @value{GDBN} C@t{++} overload debugging |
15647 | info. This includes info such as ranking of functions, etc. The default | |
15648 | is off. | |
8e04817f AC |
15649 | @item show debug overload |
15650 | Displays the current state of displaying @value{GDBN} C@t{++} overload | |
15651 | debugging info. | |
8e04817f AC |
15652 | @cindex packets, reporting on stdout |
15653 | @cindex serial connections, debugging | |
15654 | @item set debug remote | |
15655 | Turns on or off display of reports on all packets sent back and forth across | |
15656 | the serial line to the remote machine. The info is printed on the | |
15657 | @value{GDBN} standard output stream. The default is off. | |
8e04817f AC |
15658 | @item show debug remote |
15659 | Displays the state of display of remote packets. | |
8e04817f AC |
15660 | @item set debug serial |
15661 | Turns on or off display of @value{GDBN} serial debugging info. The | |
15662 | default is off. | |
8e04817f AC |
15663 | @item show debug serial |
15664 | Displays the current state of displaying @value{GDBN} serial debugging | |
15665 | info. | |
c45da7e6 EZ |
15666 | @item set debug solib-frv |
15667 | @cindex FR-V shared-library debugging | |
15668 | Turns on or off debugging messages for FR-V shared-library code. | |
15669 | @item show debug solib-frv | |
15670 | Display the current state of FR-V shared-library code debugging | |
15671 | messages. | |
8e04817f | 15672 | @item set debug target |
4644b6e3 | 15673 | @cindex target debugging info |
8e04817f AC |
15674 | Turns on or off display of @value{GDBN} target debugging info. This info |
15675 | includes what is going on at the target level of GDB, as it happens. The | |
701b08bb DJ |
15676 | default is 0. Set it to 1 to track events, and to 2 to also track the |
15677 | value of large memory transfers. Changes to this flag do not take effect | |
15678 | until the next time you connect to a target or use the @code{run} command. | |
8e04817f AC |
15679 | @item show debug target |
15680 | Displays the current state of displaying @value{GDBN} target debugging | |
15681 | info. | |
c45da7e6 | 15682 | @item set debugvarobj |
4644b6e3 | 15683 | @cindex variable object debugging info |
8e04817f AC |
15684 | Turns on or off display of @value{GDBN} variable object debugging |
15685 | info. The default is off. | |
c45da7e6 | 15686 | @item show debugvarobj |
8e04817f AC |
15687 | Displays the current state of displaying @value{GDBN} variable object |
15688 | debugging info. | |
15689 | @end table | |
104c1213 | 15690 | |
8e04817f AC |
15691 | @node Sequences |
15692 | @chapter Canned Sequences of Commands | |
104c1213 | 15693 | |
8e04817f AC |
15694 | Aside from breakpoint commands (@pxref{Break Commands, ,Breakpoint |
15695 | command lists}), @value{GDBN} provides two ways to store sequences of | |
15696 | commands for execution as a unit: user-defined commands and command | |
15697 | files. | |
104c1213 | 15698 | |
8e04817f AC |
15699 | @menu |
15700 | * Define:: User-defined commands | |
15701 | * Hooks:: User-defined command hooks | |
15702 | * Command Files:: Command files | |
15703 | * Output:: Commands for controlled output | |
15704 | @end menu | |
104c1213 | 15705 | |
8e04817f AC |
15706 | @node Define |
15707 | @section User-defined commands | |
104c1213 | 15708 | |
8e04817f AC |
15709 | @cindex user-defined command |
15710 | A @dfn{user-defined command} is a sequence of @value{GDBN} commands to | |
15711 | which you assign a new name as a command. This is done with the | |
15712 | @code{define} command. User commands may accept up to 10 arguments | |
15713 | separated by whitespace. Arguments are accessed within the user command | |
c03c782f | 15714 | via @code{$arg0@dots{}$arg9}. A trivial example: |
104c1213 | 15715 | |
8e04817f AC |
15716 | @smallexample |
15717 | define adder | |
15718 | print $arg0 + $arg1 + $arg2 | |
c03c782f | 15719 | end |
8e04817f | 15720 | @end smallexample |
104c1213 JM |
15721 | |
15722 | @noindent | |
8e04817f | 15723 | To execute the command use: |
104c1213 | 15724 | |
8e04817f AC |
15725 | @smallexample |
15726 | adder 1 2 3 | |
15727 | @end smallexample | |
104c1213 | 15728 | |
8e04817f AC |
15729 | @noindent |
15730 | This defines the command @code{adder}, which prints the sum of | |
15731 | its three arguments. Note the arguments are text substitutions, so they may | |
15732 | reference variables, use complex expressions, or even perform inferior | |
15733 | functions calls. | |
104c1213 | 15734 | |
c03c782f AS |
15735 | In addition, @code{$argc} may be used to find out how many arguments have |
15736 | been passed. This expands to a number in the range 0@dots{}10. | |
15737 | ||
15738 | @smallexample | |
15739 | define adder | |
15740 | if $argc == 2 | |
15741 | print $arg0 + $arg1 | |
15742 | end | |
15743 | if $argc == 3 | |
15744 | print $arg0 + $arg1 + $arg2 | |
15745 | end | |
15746 | end | |
15747 | @end smallexample | |
15748 | ||
104c1213 | 15749 | @table @code |
104c1213 | 15750 | |
8e04817f AC |
15751 | @kindex define |
15752 | @item define @var{commandname} | |
15753 | Define a command named @var{commandname}. If there is already a command | |
15754 | by that name, you are asked to confirm that you want to redefine it. | |
104c1213 | 15755 | |
8e04817f AC |
15756 | The definition of the command is made up of other @value{GDBN} command lines, |
15757 | which are given following the @code{define} command. The end of these | |
15758 | commands is marked by a line containing @code{end}. | |
104c1213 | 15759 | |
8e04817f AC |
15760 | @kindex if |
15761 | @kindex else | |
15762 | @item if | |
09d4efe1 | 15763 | @itemx else |
8e04817f AC |
15764 | Takes a single argument, which is an expression to evaluate. |
15765 | It is followed by a series of commands that are executed | |
15766 | only if the expression is true (nonzero). | |
15767 | There can then optionally be a line @code{else}, followed | |
15768 | by a series of commands that are only executed if the expression | |
15769 | was false. The end of the list is marked by a line containing @code{end}. | |
104c1213 | 15770 | |
8e04817f AC |
15771 | @kindex while |
15772 | @item while | |
15773 | The syntax is similar to @code{if}: the command takes a single argument, | |
15774 | which is an expression to evaluate, and must be followed by the commands to | |
15775 | execute, one per line, terminated by an @code{end}. | |
15776 | The commands are executed repeatedly as long as the expression | |
15777 | evaluates to true. | |
104c1213 | 15778 | |
8e04817f AC |
15779 | @kindex document |
15780 | @item document @var{commandname} | |
15781 | Document the user-defined command @var{commandname}, so that it can be | |
15782 | accessed by @code{help}. The command @var{commandname} must already be | |
15783 | defined. This command reads lines of documentation just as @code{define} | |
15784 | reads the lines of the command definition, ending with @code{end}. | |
15785 | After the @code{document} command is finished, @code{help} on command | |
15786 | @var{commandname} displays the documentation you have written. | |
104c1213 | 15787 | |
8e04817f AC |
15788 | You may use the @code{document} command again to change the |
15789 | documentation of a command. Redefining the command with @code{define} | |
15790 | does not change the documentation. | |
104c1213 | 15791 | |
c45da7e6 EZ |
15792 | @kindex dont-repeat |
15793 | @cindex don't repeat command | |
15794 | @item dont-repeat | |
15795 | Used inside a user-defined command, this tells @value{GDBN} that this | |
15796 | command should not be repeated when the user hits @key{RET} | |
15797 | (@pxref{Command Syntax, repeat last command}). | |
15798 | ||
8e04817f AC |
15799 | @kindex help user-defined |
15800 | @item help user-defined | |
15801 | List all user-defined commands, with the first line of the documentation | |
15802 | (if any) for each. | |
104c1213 | 15803 | |
8e04817f AC |
15804 | @kindex show user |
15805 | @item show user | |
15806 | @itemx show user @var{commandname} | |
15807 | Display the @value{GDBN} commands used to define @var{commandname} (but | |
15808 | not its documentation). If no @var{commandname} is given, display the | |
15809 | definitions for all user-defined commands. | |
104c1213 | 15810 | |
9c16f35a | 15811 | @cindex infinite recusrion in user-defined commands |
20f01a46 DH |
15812 | @kindex show max-user-call-depth |
15813 | @kindex set max-user-call-depth | |
15814 | @item show max-user-call-depth | |
5ca0cb28 DH |
15815 | @itemx set max-user-call-depth |
15816 | The value of @code{max-user-call-depth} controls how many recursion | |
15817 | levels are allowed in user-defined commands before GDB suspects an | |
15818 | infinite recursion and aborts the command. | |
20f01a46 | 15819 | |
104c1213 JM |
15820 | @end table |
15821 | ||
8e04817f AC |
15822 | When user-defined commands are executed, the |
15823 | commands of the definition are not printed. An error in any command | |
15824 | stops execution of the user-defined command. | |
104c1213 | 15825 | |
8e04817f AC |
15826 | If used interactively, commands that would ask for confirmation proceed |
15827 | without asking when used inside a user-defined command. Many @value{GDBN} | |
15828 | commands that normally print messages to say what they are doing omit the | |
15829 | messages when used in a user-defined command. | |
104c1213 | 15830 | |
8e04817f AC |
15831 | @node Hooks |
15832 | @section User-defined command hooks | |
15833 | @cindex command hooks | |
15834 | @cindex hooks, for commands | |
15835 | @cindex hooks, pre-command | |
104c1213 | 15836 | |
8e04817f | 15837 | @kindex hook |
8e04817f AC |
15838 | You may define @dfn{hooks}, which are a special kind of user-defined |
15839 | command. Whenever you run the command @samp{foo}, if the user-defined | |
15840 | command @samp{hook-foo} exists, it is executed (with no arguments) | |
15841 | before that command. | |
104c1213 | 15842 | |
8e04817f AC |
15843 | @cindex hooks, post-command |
15844 | @kindex hookpost | |
8e04817f AC |
15845 | A hook may also be defined which is run after the command you executed. |
15846 | Whenever you run the command @samp{foo}, if the user-defined command | |
15847 | @samp{hookpost-foo} exists, it is executed (with no arguments) after | |
15848 | that command. Post-execution hooks may exist simultaneously with | |
15849 | pre-execution hooks, for the same command. | |
104c1213 | 15850 | |
8e04817f | 15851 | It is valid for a hook to call the command which it hooks. If this |
9f1c6395 | 15852 | occurs, the hook is not re-executed, thereby avoiding infinite recursion. |
104c1213 | 15853 | |
8e04817f AC |
15854 | @c It would be nice if hookpost could be passed a parameter indicating |
15855 | @c if the command it hooks executed properly or not. FIXME! | |
104c1213 | 15856 | |
8e04817f AC |
15857 | @kindex stop@r{, a pseudo-command} |
15858 | In addition, a pseudo-command, @samp{stop} exists. Defining | |
15859 | (@samp{hook-stop}) makes the associated commands execute every time | |
15860 | execution stops in your program: before breakpoint commands are run, | |
15861 | displays are printed, or the stack frame is printed. | |
104c1213 | 15862 | |
8e04817f AC |
15863 | For example, to ignore @code{SIGALRM} signals while |
15864 | single-stepping, but treat them normally during normal execution, | |
15865 | you could define: | |
104c1213 | 15866 | |
474c8240 | 15867 | @smallexample |
8e04817f AC |
15868 | define hook-stop |
15869 | handle SIGALRM nopass | |
15870 | end | |
104c1213 | 15871 | |
8e04817f AC |
15872 | define hook-run |
15873 | handle SIGALRM pass | |
15874 | end | |
104c1213 | 15875 | |
8e04817f AC |
15876 | define hook-continue |
15877 | handle SIGLARM pass | |
15878 | end | |
474c8240 | 15879 | @end smallexample |
104c1213 | 15880 | |
8e04817f | 15881 | As a further example, to hook at the begining and end of the @code{echo} |
b383017d | 15882 | command, and to add extra text to the beginning and end of the message, |
8e04817f | 15883 | you could define: |
104c1213 | 15884 | |
474c8240 | 15885 | @smallexample |
8e04817f AC |
15886 | define hook-echo |
15887 | echo <<<--- | |
15888 | end | |
104c1213 | 15889 | |
8e04817f AC |
15890 | define hookpost-echo |
15891 | echo --->>>\n | |
15892 | end | |
104c1213 | 15893 | |
8e04817f AC |
15894 | (@value{GDBP}) echo Hello World |
15895 | <<<---Hello World--->>> | |
15896 | (@value{GDBP}) | |
104c1213 | 15897 | |
474c8240 | 15898 | @end smallexample |
104c1213 | 15899 | |
8e04817f AC |
15900 | You can define a hook for any single-word command in @value{GDBN}, but |
15901 | not for command aliases; you should define a hook for the basic command | |
15902 | name, e.g. @code{backtrace} rather than @code{bt}. | |
15903 | @c FIXME! So how does Joe User discover whether a command is an alias | |
15904 | @c or not? | |
15905 | If an error occurs during the execution of your hook, execution of | |
15906 | @value{GDBN} commands stops and @value{GDBN} issues a prompt | |
15907 | (before the command that you actually typed had a chance to run). | |
104c1213 | 15908 | |
8e04817f AC |
15909 | If you try to define a hook which does not match any known command, you |
15910 | get a warning from the @code{define} command. | |
c906108c | 15911 | |
8e04817f AC |
15912 | @node Command Files |
15913 | @section Command files | |
c906108c | 15914 | |
8e04817f | 15915 | @cindex command files |
6fc08d32 EZ |
15916 | A command file for @value{GDBN} is a text file made of lines that are |
15917 | @value{GDBN} commands. Comments (lines starting with @kbd{#}) may | |
15918 | also be included. An empty line in a command file does nothing; it | |
15919 | does not mean to repeat the last command, as it would from the | |
15920 | terminal. | |
c906108c | 15921 | |
6fc08d32 EZ |
15922 | You can request the execution of a command file with the @code{source} |
15923 | command: | |
c906108c | 15924 | |
8e04817f AC |
15925 | @table @code |
15926 | @kindex source | |
15927 | @item source @var{filename} | |
15928 | Execute the command file @var{filename}. | |
c906108c SS |
15929 | @end table |
15930 | ||
8e04817f | 15931 | The lines in a command file are executed sequentially. They are not |
a71ec265 DH |
15932 | printed as they are executed. An error in any command terminates |
15933 | execution of the command file and control is returned to the console. | |
c906108c | 15934 | |
8e04817f AC |
15935 | Commands that would ask for confirmation if used interactively proceed |
15936 | without asking when used in a command file. Many @value{GDBN} commands that | |
15937 | normally print messages to say what they are doing omit the messages | |
15938 | when called from command files. | |
c906108c | 15939 | |
8e04817f AC |
15940 | @value{GDBN} also accepts command input from standard input. In this |
15941 | mode, normal output goes to standard output and error output goes to | |
15942 | standard error. Errors in a command file supplied on standard input do | |
6fc08d32 | 15943 | not terminate execution of the command file---execution continues with |
8e04817f | 15944 | the next command. |
c906108c | 15945 | |
474c8240 | 15946 | @smallexample |
8e04817f | 15947 | gdb < cmds > log 2>&1 |
474c8240 | 15948 | @end smallexample |
c906108c | 15949 | |
8e04817f AC |
15950 | (The syntax above will vary depending on the shell used.) This example |
15951 | will execute commands from the file @file{cmds}. All output and errors | |
15952 | would be directed to @file{log}. | |
c906108c | 15953 | |
8e04817f AC |
15954 | @node Output |
15955 | @section Commands for controlled output | |
c906108c | 15956 | |
8e04817f AC |
15957 | During the execution of a command file or a user-defined command, normal |
15958 | @value{GDBN} output is suppressed; the only output that appears is what is | |
15959 | explicitly printed by the commands in the definition. This section | |
15960 | describes three commands useful for generating exactly the output you | |
15961 | want. | |
c906108c SS |
15962 | |
15963 | @table @code | |
8e04817f AC |
15964 | @kindex echo |
15965 | @item echo @var{text} | |
15966 | @c I do not consider backslash-space a standard C escape sequence | |
15967 | @c because it is not in ANSI. | |
15968 | Print @var{text}. Nonprinting characters can be included in | |
15969 | @var{text} using C escape sequences, such as @samp{\n} to print a | |
15970 | newline. @strong{No newline is printed unless you specify one.} | |
15971 | In addition to the standard C escape sequences, a backslash followed | |
15972 | by a space stands for a space. This is useful for displaying a | |
15973 | string with spaces at the beginning or the end, since leading and | |
15974 | trailing spaces are otherwise trimmed from all arguments. | |
15975 | To print @samp{@w{ }and foo =@w{ }}, use the command | |
15976 | @samp{echo \@w{ }and foo = \@w{ }}. | |
c906108c | 15977 | |
8e04817f AC |
15978 | A backslash at the end of @var{text} can be used, as in C, to continue |
15979 | the command onto subsequent lines. For example, | |
c906108c | 15980 | |
474c8240 | 15981 | @smallexample |
8e04817f AC |
15982 | echo This is some text\n\ |
15983 | which is continued\n\ | |
15984 | onto several lines.\n | |
474c8240 | 15985 | @end smallexample |
c906108c | 15986 | |
8e04817f | 15987 | produces the same output as |
c906108c | 15988 | |
474c8240 | 15989 | @smallexample |
8e04817f AC |
15990 | echo This is some text\n |
15991 | echo which is continued\n | |
15992 | echo onto several lines.\n | |
474c8240 | 15993 | @end smallexample |
c906108c | 15994 | |
8e04817f AC |
15995 | @kindex output |
15996 | @item output @var{expression} | |
15997 | Print the value of @var{expression} and nothing but that value: no | |
15998 | newlines, no @samp{$@var{nn} = }. The value is not entered in the | |
15999 | value history either. @xref{Expressions, ,Expressions}, for more information | |
16000 | on expressions. | |
c906108c | 16001 | |
8e04817f AC |
16002 | @item output/@var{fmt} @var{expression} |
16003 | Print the value of @var{expression} in format @var{fmt}. You can use | |
16004 | the same formats as for @code{print}. @xref{Output Formats,,Output | |
16005 | formats}, for more information. | |
c906108c | 16006 | |
8e04817f AC |
16007 | @kindex printf |
16008 | @item printf @var{string}, @var{expressions}@dots{} | |
16009 | Print the values of the @var{expressions} under the control of | |
16010 | @var{string}. The @var{expressions} are separated by commas and may be | |
16011 | either numbers or pointers. Their values are printed as specified by | |
16012 | @var{string}, exactly as if your program were to execute the C | |
16013 | subroutine | |
16014 | @c FIXME: the above implies that at least all ANSI C formats are | |
16015 | @c supported, but it isn't true: %E and %G don't work (or so it seems). | |
16016 | @c Either this is a bug, or the manual should document what formats are | |
16017 | @c supported. | |
c906108c | 16018 | |
474c8240 | 16019 | @smallexample |
8e04817f | 16020 | printf (@var{string}, @var{expressions}@dots{}); |
474c8240 | 16021 | @end smallexample |
c906108c | 16022 | |
8e04817f | 16023 | For example, you can print two values in hex like this: |
c906108c | 16024 | |
8e04817f AC |
16025 | @smallexample |
16026 | printf "foo, bar-foo = 0x%x, 0x%x\n", foo, bar-foo | |
16027 | @end smallexample | |
c906108c | 16028 | |
8e04817f AC |
16029 | The only backslash-escape sequences that you can use in the format |
16030 | string are the simple ones that consist of backslash followed by a | |
16031 | letter. | |
c906108c SS |
16032 | @end table |
16033 | ||
21c294e6 AC |
16034 | @node Interpreters |
16035 | @chapter Command Interpreters | |
16036 | @cindex command interpreters | |
16037 | ||
16038 | @value{GDBN} supports multiple command interpreters, and some command | |
16039 | infrastructure to allow users or user interface writers to switch | |
16040 | between interpreters or run commands in other interpreters. | |
16041 | ||
16042 | @value{GDBN} currently supports two command interpreters, the console | |
16043 | interpreter (sometimes called the command-line interpreter or @sc{cli}) | |
16044 | and the machine interface interpreter (or @sc{gdb/mi}). This manual | |
16045 | describes both of these interfaces in great detail. | |
16046 | ||
16047 | By default, @value{GDBN} will start with the console interpreter. | |
16048 | However, the user may choose to start @value{GDBN} with another | |
16049 | interpreter by specifying the @option{-i} or @option{--interpreter} | |
16050 | startup options. Defined interpreters include: | |
16051 | ||
16052 | @table @code | |
16053 | @item console | |
16054 | @cindex console interpreter | |
16055 | The traditional console or command-line interpreter. This is the most often | |
16056 | used interpreter with @value{GDBN}. With no interpreter specified at runtime, | |
16057 | @value{GDBN} will use this interpreter. | |
16058 | ||
16059 | @item mi | |
16060 | @cindex mi interpreter | |
16061 | The newest @sc{gdb/mi} interface (currently @code{mi2}). Used primarily | |
16062 | by programs wishing to use @value{GDBN} as a backend for a debugger GUI | |
16063 | or an IDE. For more information, see @ref{GDB/MI, ,The @sc{gdb/mi} | |
16064 | Interface}. | |
16065 | ||
16066 | @item mi2 | |
16067 | @cindex mi2 interpreter | |
16068 | The current @sc{gdb/mi} interface. | |
16069 | ||
16070 | @item mi1 | |
16071 | @cindex mi1 interpreter | |
16072 | The @sc{gdb/mi} interface included in @value{GDBN} 5.1, 5.2, and 5.3. | |
16073 | ||
16074 | @end table | |
16075 | ||
16076 | @cindex invoke another interpreter | |
16077 | The interpreter being used by @value{GDBN} may not be dynamically | |
16078 | switched at runtime. Although possible, this could lead to a very | |
16079 | precarious situation. Consider an IDE using @sc{gdb/mi}. If a user | |
16080 | enters the command "interpreter-set console" in a console view, | |
16081 | @value{GDBN} would switch to using the console interpreter, rendering | |
16082 | the IDE inoperable! | |
16083 | ||
16084 | @kindex interpreter-exec | |
16085 | Although you may only choose a single interpreter at startup, you may execute | |
16086 | commands in any interpreter from the current interpreter using the appropriate | |
16087 | command. If you are running the console interpreter, simply use the | |
16088 | @code{interpreter-exec} command: | |
16089 | ||
16090 | @smallexample | |
16091 | interpreter-exec mi "-data-list-register-names" | |
16092 | @end smallexample | |
16093 | ||
16094 | @sc{gdb/mi} has a similar command, although it is only available in versions of | |
16095 | @value{GDBN} which support @sc{gdb/mi} version 2 (or greater). | |
16096 | ||
8e04817f AC |
16097 | @node TUI |
16098 | @chapter @value{GDBN} Text User Interface | |
16099 | @cindex TUI | |
d0d5df6f | 16100 | @cindex Text User Interface |
c906108c | 16101 | |
8e04817f AC |
16102 | @menu |
16103 | * TUI Overview:: TUI overview | |
16104 | * TUI Keys:: TUI key bindings | |
7cf36c78 | 16105 | * TUI Single Key Mode:: TUI single key mode |
8e04817f AC |
16106 | * TUI Commands:: TUI specific commands |
16107 | * TUI Configuration:: TUI configuration variables | |
16108 | @end menu | |
c906108c | 16109 | |
d0d5df6f AC |
16110 | The @value{GDBN} Text User Interface, TUI in short, is a terminal |
16111 | interface which uses the @code{curses} library to show the source | |
16112 | file, the assembly output, the program registers and @value{GDBN} | |
16113 | commands in separate text windows. | |
16114 | ||
16115 | The TUI is enabled by invoking @value{GDBN} using either | |
16116 | @pindex gdbtui | |
16117 | @samp{gdbtui} or @samp{gdb -tui}. | |
c906108c | 16118 | |
8e04817f AC |
16119 | @node TUI Overview |
16120 | @section TUI overview | |
c906108c | 16121 | |
8e04817f AC |
16122 | The TUI has two display modes that can be switched while |
16123 | @value{GDBN} runs: | |
c906108c | 16124 | |
8e04817f AC |
16125 | @itemize @bullet |
16126 | @item | |
16127 | A curses (or TUI) mode in which it displays several text | |
16128 | windows on the terminal. | |
c906108c | 16129 | |
8e04817f AC |
16130 | @item |
16131 | A standard mode which corresponds to the @value{GDBN} configured without | |
16132 | the TUI. | |
16133 | @end itemize | |
c906108c | 16134 | |
8e04817f AC |
16135 | In the TUI mode, @value{GDBN} can display several text window |
16136 | on the terminal: | |
c906108c | 16137 | |
8e04817f AC |
16138 | @table @emph |
16139 | @item command | |
16140 | This window is the @value{GDBN} command window with the @value{GDBN} | |
16141 | prompt and the @value{GDBN} outputs. The @value{GDBN} input is still | |
16142 | managed using readline but through the TUI. The @emph{command} | |
16143 | window is always visible. | |
c906108c | 16144 | |
8e04817f AC |
16145 | @item source |
16146 | The source window shows the source file of the program. The current | |
16147 | line as well as active breakpoints are displayed in this window. | |
c906108c | 16148 | |
8e04817f AC |
16149 | @item assembly |
16150 | The assembly window shows the disassembly output of the program. | |
c906108c | 16151 | |
8e04817f AC |
16152 | @item register |
16153 | This window shows the processor registers. It detects when | |
16154 | a register is changed and when this is the case, registers that have | |
6a1b180d | 16155 | changed are highlighted. |
c906108c | 16156 | |
c906108c SS |
16157 | @end table |
16158 | ||
269c21fe SC |
16159 | The source and assembly windows show the current program position |
16160 | by highlighting the current line and marking them with the @samp{>} marker. | |
16161 | Breakpoints are also indicated with two markers. A first one | |
16162 | indicates the breakpoint type: | |
16163 | ||
16164 | @table @code | |
16165 | @item B | |
16166 | Breakpoint which was hit at least once. | |
16167 | ||
16168 | @item b | |
16169 | Breakpoint which was never hit. | |
16170 | ||
16171 | @item H | |
16172 | Hardware breakpoint which was hit at least once. | |
16173 | ||
16174 | @item h | |
16175 | Hardware breakpoint which was never hit. | |
16176 | ||
16177 | @end table | |
16178 | ||
16179 | The second marker indicates whether the breakpoint is enabled or not: | |
16180 | ||
16181 | @table @code | |
16182 | @item + | |
16183 | Breakpoint is enabled. | |
16184 | ||
16185 | @item - | |
16186 | Breakpoint is disabled. | |
16187 | ||
16188 | @end table | |
16189 | ||
8e04817f AC |
16190 | The source, assembly and register windows are attached to the thread |
16191 | and the frame position. They are updated when the current thread | |
16192 | changes, when the frame changes or when the program counter changes. | |
16193 | These three windows are arranged by the TUI according to several | |
16194 | layouts. The layout defines which of these three windows are visible. | |
16195 | The following layouts are available: | |
c906108c | 16196 | |
8e04817f AC |
16197 | @itemize @bullet |
16198 | @item | |
16199 | source | |
2df3850c | 16200 | |
8e04817f AC |
16201 | @item |
16202 | assembly | |
16203 | ||
16204 | @item | |
16205 | source and assembly | |
16206 | ||
16207 | @item | |
16208 | source and registers | |
c906108c | 16209 | |
8e04817f AC |
16210 | @item |
16211 | assembly and registers | |
2df3850c | 16212 | |
8e04817f | 16213 | @end itemize |
c906108c | 16214 | |
b7bb15bc SC |
16215 | On top of the command window a status line gives various information |
16216 | concerning the current process begin debugged. The status line is | |
16217 | updated when the information it shows changes. The following fields | |
16218 | are displayed: | |
16219 | ||
16220 | @table @emph | |
16221 | @item target | |
16222 | Indicates the current gdb target | |
16223 | (@pxref{Targets, ,Specifying a Debugging Target}). | |
16224 | ||
16225 | @item process | |
16226 | Gives information about the current process or thread number. | |
16227 | When no process is being debugged, this field is set to @code{No process}. | |
16228 | ||
16229 | @item function | |
16230 | Gives the current function name for the selected frame. | |
16231 | The name is demangled if demangling is turned on (@pxref{Print Settings}). | |
16232 | When there is no symbol corresponding to the current program counter | |
16233 | the string @code{??} is displayed. | |
16234 | ||
16235 | @item line | |
16236 | Indicates the current line number for the selected frame. | |
16237 | When the current line number is not known the string @code{??} is displayed. | |
16238 | ||
16239 | @item pc | |
16240 | Indicates the current program counter address. | |
16241 | ||
16242 | @end table | |
16243 | ||
8e04817f AC |
16244 | @node TUI Keys |
16245 | @section TUI Key Bindings | |
16246 | @cindex TUI key bindings | |
c906108c | 16247 | |
8e04817f AC |
16248 | The TUI installs several key bindings in the readline keymaps |
16249 | (@pxref{Command Line Editing}). | |
16250 | They allow to leave or enter in the TUI mode or they operate | |
7cf36c78 SC |
16251 | directly on the TUI layout and windows. The TUI also provides |
16252 | a @emph{SingleKey} keymap which binds several keys directly to | |
16253 | @value{GDBN} commands. The following key bindings | |
8e04817f | 16254 | are installed for both TUI mode and the @value{GDBN} standard mode. |
c906108c | 16255 | |
8e04817f AC |
16256 | @table @kbd |
16257 | @kindex C-x C-a | |
16258 | @item C-x C-a | |
16259 | @kindex C-x a | |
16260 | @itemx C-x a | |
16261 | @kindex C-x A | |
16262 | @itemx C-x A | |
16263 | Enter or leave the TUI mode. When the TUI mode is left, | |
16264 | the curses window management is left and @value{GDBN} operates using | |
16265 | its standard mode writing on the terminal directly. When the TUI | |
16266 | mode is entered, the control is given back to the curses windows. | |
16267 | The screen is then refreshed. | |
c906108c | 16268 | |
8e04817f AC |
16269 | @kindex C-x 1 |
16270 | @item C-x 1 | |
16271 | Use a TUI layout with only one window. The layout will | |
16272 | either be @samp{source} or @samp{assembly}. When the TUI mode | |
16273 | is not active, it will switch to the TUI mode. | |
2df3850c | 16274 | |
8e04817f | 16275 | Think of this key binding as the Emacs @kbd{C-x 1} binding. |
c906108c | 16276 | |
8e04817f AC |
16277 | @kindex C-x 2 |
16278 | @item C-x 2 | |
16279 | Use a TUI layout with at least two windows. When the current | |
16280 | layout shows already two windows, a next layout with two windows is used. | |
16281 | When a new layout is chosen, one window will always be common to the | |
16282 | previous layout and the new one. | |
c906108c | 16283 | |
8e04817f | 16284 | Think of it as the Emacs @kbd{C-x 2} binding. |
2df3850c | 16285 | |
72ffddc9 SC |
16286 | @kindex C-x o |
16287 | @item C-x o | |
16288 | Change the active window. The TUI associates several key bindings | |
16289 | (like scrolling and arrow keys) to the active window. This command | |
16290 | gives the focus to the next TUI window. | |
16291 | ||
16292 | Think of it as the Emacs @kbd{C-x o} binding. | |
16293 | ||
7cf36c78 SC |
16294 | @kindex C-x s |
16295 | @item C-x s | |
16296 | Use the TUI @emph{SingleKey} keymap that binds single key to gdb commands | |
16297 | (@pxref{TUI Single Key Mode}). | |
16298 | ||
c906108c SS |
16299 | @end table |
16300 | ||
8e04817f | 16301 | The following key bindings are handled only by the TUI mode: |
5d161b24 | 16302 | |
8e04817f AC |
16303 | @table @key |
16304 | @kindex PgUp | |
16305 | @item PgUp | |
16306 | Scroll the active window one page up. | |
c906108c | 16307 | |
8e04817f AC |
16308 | @kindex PgDn |
16309 | @item PgDn | |
16310 | Scroll the active window one page down. | |
c906108c | 16311 | |
8e04817f AC |
16312 | @kindex Up |
16313 | @item Up | |
16314 | Scroll the active window one line up. | |
c906108c | 16315 | |
8e04817f AC |
16316 | @kindex Down |
16317 | @item Down | |
16318 | Scroll the active window one line down. | |
c906108c | 16319 | |
8e04817f AC |
16320 | @kindex Left |
16321 | @item Left | |
16322 | Scroll the active window one column left. | |
c906108c | 16323 | |
8e04817f AC |
16324 | @kindex Right |
16325 | @item Right | |
16326 | Scroll the active window one column right. | |
c906108c | 16327 | |
8e04817f AC |
16328 | @kindex C-L |
16329 | @item C-L | |
16330 | Refresh the screen. | |
c906108c | 16331 | |
8e04817f | 16332 | @end table |
c906108c | 16333 | |
8e04817f | 16334 | In the TUI mode, the arrow keys are used by the active window |
72ffddc9 SC |
16335 | for scrolling. This means they are available for readline when the |
16336 | active window is the command window. When the command window | |
16337 | does not have the focus, it is necessary to use other readline | |
16338 | key bindings such as @key{C-p}, @key{C-n}, @key{C-b} and @key{C-f}. | |
8e04817f | 16339 | |
7cf36c78 SC |
16340 | @node TUI Single Key Mode |
16341 | @section TUI Single Key Mode | |
16342 | @cindex TUI single key mode | |
16343 | ||
16344 | The TUI provides a @emph{SingleKey} mode in which it installs a particular | |
16345 | key binding in the readline keymaps to connect single keys to | |
b383017d | 16346 | some gdb commands. |
7cf36c78 SC |
16347 | |
16348 | @table @kbd | |
16349 | @kindex c @r{(SingleKey TUI key)} | |
16350 | @item c | |
16351 | continue | |
16352 | ||
16353 | @kindex d @r{(SingleKey TUI key)} | |
16354 | @item d | |
16355 | down | |
16356 | ||
16357 | @kindex f @r{(SingleKey TUI key)} | |
16358 | @item f | |
16359 | finish | |
16360 | ||
16361 | @kindex n @r{(SingleKey TUI key)} | |
16362 | @item n | |
16363 | next | |
16364 | ||
16365 | @kindex q @r{(SingleKey TUI key)} | |
16366 | @item q | |
16367 | exit the @emph{SingleKey} mode. | |
16368 | ||
16369 | @kindex r @r{(SingleKey TUI key)} | |
16370 | @item r | |
16371 | run | |
16372 | ||
16373 | @kindex s @r{(SingleKey TUI key)} | |
16374 | @item s | |
16375 | step | |
16376 | ||
16377 | @kindex u @r{(SingleKey TUI key)} | |
16378 | @item u | |
16379 | up | |
16380 | ||
16381 | @kindex v @r{(SingleKey TUI key)} | |
16382 | @item v | |
16383 | info locals | |
16384 | ||
16385 | @kindex w @r{(SingleKey TUI key)} | |
16386 | @item w | |
16387 | where | |
16388 | ||
16389 | @end table | |
16390 | ||
16391 | Other keys temporarily switch to the @value{GDBN} command prompt. | |
16392 | The key that was pressed is inserted in the editing buffer so that | |
16393 | it is possible to type most @value{GDBN} commands without interaction | |
16394 | with the TUI @emph{SingleKey} mode. Once the command is entered the TUI | |
16395 | @emph{SingleKey} mode is restored. The only way to permanently leave | |
16396 | this mode is by hitting @key{q} or @samp{@key{C-x} @key{s}}. | |
16397 | ||
16398 | ||
8e04817f AC |
16399 | @node TUI Commands |
16400 | @section TUI specific commands | |
16401 | @cindex TUI commands | |
16402 | ||
16403 | The TUI has specific commands to control the text windows. | |
16404 | These commands are always available, that is they do not depend on | |
16405 | the current terminal mode in which @value{GDBN} runs. When @value{GDBN} | |
16406 | is in the standard mode, using these commands will automatically switch | |
16407 | in the TUI mode. | |
c906108c SS |
16408 | |
16409 | @table @code | |
3d757584 SC |
16410 | @item info win |
16411 | @kindex info win | |
16412 | List and give the size of all displayed windows. | |
16413 | ||
8e04817f | 16414 | @item layout next |
4644b6e3 | 16415 | @kindex layout |
8e04817f | 16416 | Display the next layout. |
2df3850c | 16417 | |
8e04817f | 16418 | @item layout prev |
8e04817f | 16419 | Display the previous layout. |
c906108c | 16420 | |
8e04817f | 16421 | @item layout src |
8e04817f | 16422 | Display the source window only. |
c906108c | 16423 | |
8e04817f | 16424 | @item layout asm |
8e04817f | 16425 | Display the assembly window only. |
c906108c | 16426 | |
8e04817f | 16427 | @item layout split |
8e04817f | 16428 | Display the source and assembly window. |
c906108c | 16429 | |
8e04817f | 16430 | @item layout regs |
8e04817f AC |
16431 | Display the register window together with the source or assembly window. |
16432 | ||
16433 | @item focus next | prev | src | asm | regs | split | |
16434 | @kindex focus | |
16435 | Set the focus to the named window. | |
16436 | This command allows to change the active window so that scrolling keys | |
16437 | can be affected to another window. | |
c906108c | 16438 | |
8e04817f AC |
16439 | @item refresh |
16440 | @kindex refresh | |
16441 | Refresh the screen. This is similar to using @key{C-L} key. | |
c906108c | 16442 | |
6a1b180d SC |
16443 | @item tui reg float |
16444 | @kindex tui reg | |
16445 | Show the floating point registers in the register window. | |
16446 | ||
16447 | @item tui reg general | |
16448 | Show the general registers in the register window. | |
16449 | ||
16450 | @item tui reg next | |
16451 | Show the next register group. The list of register groups as well as | |
16452 | their order is target specific. The predefined register groups are the | |
16453 | following: @code{general}, @code{float}, @code{system}, @code{vector}, | |
16454 | @code{all}, @code{save}, @code{restore}. | |
16455 | ||
16456 | @item tui reg system | |
16457 | Show the system registers in the register window. | |
16458 | ||
8e04817f AC |
16459 | @item update |
16460 | @kindex update | |
16461 | Update the source window and the current execution point. | |
c906108c | 16462 | |
8e04817f AC |
16463 | @item winheight @var{name} +@var{count} |
16464 | @itemx winheight @var{name} -@var{count} | |
16465 | @kindex winheight | |
16466 | Change the height of the window @var{name} by @var{count} | |
16467 | lines. Positive counts increase the height, while negative counts | |
16468 | decrease it. | |
2df3850c | 16469 | |
c45da7e6 EZ |
16470 | @item tabset |
16471 | @kindex tabset @var{nchars} | |
16472 | Set the width of tab stops to be @var{nchars} characters. | |
16473 | ||
c906108c SS |
16474 | @end table |
16475 | ||
8e04817f AC |
16476 | @node TUI Configuration |
16477 | @section TUI configuration variables | |
16478 | @cindex TUI configuration variables | |
c906108c | 16479 | |
8e04817f AC |
16480 | The TUI has several configuration variables that control the |
16481 | appearance of windows on the terminal. | |
c906108c | 16482 | |
8e04817f AC |
16483 | @table @code |
16484 | @item set tui border-kind @var{kind} | |
16485 | @kindex set tui border-kind | |
16486 | Select the border appearance for the source, assembly and register windows. | |
16487 | The possible values are the following: | |
16488 | @table @code | |
16489 | @item space | |
16490 | Use a space character to draw the border. | |
c906108c | 16491 | |
8e04817f AC |
16492 | @item ascii |
16493 | Use ascii characters + - and | to draw the border. | |
c906108c | 16494 | |
8e04817f AC |
16495 | @item acs |
16496 | Use the Alternate Character Set to draw the border. The border is | |
16497 | drawn using character line graphics if the terminal supports them. | |
c78b4128 | 16498 | |
8e04817f | 16499 | @end table |
c78b4128 | 16500 | |
8e04817f AC |
16501 | @item set tui active-border-mode @var{mode} |
16502 | @kindex set tui active-border-mode | |
16503 | Select the attributes to display the border of the active window. | |
16504 | The possible values are @code{normal}, @code{standout}, @code{reverse}, | |
16505 | @code{half}, @code{half-standout}, @code{bold} and @code{bold-standout}. | |
c78b4128 | 16506 | |
8e04817f AC |
16507 | @item set tui border-mode @var{mode} |
16508 | @kindex set tui border-mode | |
16509 | Select the attributes to display the border of other windows. | |
16510 | The @var{mode} can be one of the following: | |
16511 | @table @code | |
16512 | @item normal | |
16513 | Use normal attributes to display the border. | |
c906108c | 16514 | |
8e04817f AC |
16515 | @item standout |
16516 | Use standout mode. | |
c906108c | 16517 | |
8e04817f AC |
16518 | @item reverse |
16519 | Use reverse video mode. | |
c906108c | 16520 | |
8e04817f AC |
16521 | @item half |
16522 | Use half bright mode. | |
c906108c | 16523 | |
8e04817f AC |
16524 | @item half-standout |
16525 | Use half bright and standout mode. | |
c906108c | 16526 | |
8e04817f AC |
16527 | @item bold |
16528 | Use extra bright or bold mode. | |
c78b4128 | 16529 | |
8e04817f AC |
16530 | @item bold-standout |
16531 | Use extra bright or bold and standout mode. | |
c78b4128 | 16532 | |
8e04817f | 16533 | @end table |
c78b4128 | 16534 | |
8e04817f | 16535 | @end table |
c78b4128 | 16536 | |
8e04817f AC |
16537 | @node Emacs |
16538 | @chapter Using @value{GDBN} under @sc{gnu} Emacs | |
c78b4128 | 16539 | |
8e04817f AC |
16540 | @cindex Emacs |
16541 | @cindex @sc{gnu} Emacs | |
16542 | A special interface allows you to use @sc{gnu} Emacs to view (and | |
16543 | edit) the source files for the program you are debugging with | |
16544 | @value{GDBN}. | |
c906108c | 16545 | |
8e04817f AC |
16546 | To use this interface, use the command @kbd{M-x gdb} in Emacs. Give the |
16547 | executable file you want to debug as an argument. This command starts | |
16548 | @value{GDBN} as a subprocess of Emacs, with input and output through a newly | |
16549 | created Emacs buffer. | |
16550 | @c (Do not use the @code{-tui} option to run @value{GDBN} from Emacs.) | |
c906108c | 16551 | |
8e04817f AC |
16552 | Using @value{GDBN} under Emacs is just like using @value{GDBN} normally except for two |
16553 | things: | |
c906108c | 16554 | |
8e04817f AC |
16555 | @itemize @bullet |
16556 | @item | |
16557 | All ``terminal'' input and output goes through the Emacs buffer. | |
16558 | @end itemize | |
c906108c | 16559 | |
8e04817f AC |
16560 | This applies both to @value{GDBN} commands and their output, and to the input |
16561 | and output done by the program you are debugging. | |
bf0184be | 16562 | |
8e04817f AC |
16563 | This is useful because it means that you can copy the text of previous |
16564 | commands and input them again; you can even use parts of the output | |
16565 | in this way. | |
bf0184be | 16566 | |
8e04817f AC |
16567 | All the facilities of Emacs' Shell mode are available for interacting |
16568 | with your program. In particular, you can send signals the usual | |
16569 | way---for example, @kbd{C-c C-c} for an interrupt, @kbd{C-c C-z} for a | |
16570 | stop. | |
bf0184be | 16571 | |
8e04817f | 16572 | @itemize @bullet |
bf0184be | 16573 | @item |
8e04817f AC |
16574 | @value{GDBN} displays source code through Emacs. |
16575 | @end itemize | |
bf0184be | 16576 | |
8e04817f AC |
16577 | Each time @value{GDBN} displays a stack frame, Emacs automatically finds the |
16578 | source file for that frame and puts an arrow (@samp{=>}) at the | |
16579 | left margin of the current line. Emacs uses a separate buffer for | |
16580 | source display, and splits the screen to show both your @value{GDBN} session | |
16581 | and the source. | |
bf0184be | 16582 | |
8e04817f AC |
16583 | Explicit @value{GDBN} @code{list} or search commands still produce output as |
16584 | usual, but you probably have no reason to use them from Emacs. | |
c906108c | 16585 | |
64fabec2 AC |
16586 | If you specify an absolute file name when prompted for the @kbd{M-x |
16587 | gdb} argument, then Emacs sets your current working directory to where | |
16588 | your program resides. If you only specify the file name, then Emacs | |
16589 | sets your current working directory to to the directory associated | |
16590 | with the previous buffer. In this case, @value{GDBN} may find your | |
16591 | program by searching your environment's @code{PATH} variable, but on | |
16592 | some operating systems it might not find the source. So, although the | |
16593 | @value{GDBN} input and output session proceeds normally, the auxiliary | |
16594 | buffer does not display the current source and line of execution. | |
16595 | ||
16596 | The initial working directory of @value{GDBN} is printed on the top | |
16597 | line of the @value{GDBN} I/O buffer and this serves as a default for | |
16598 | the commands that specify files for @value{GDBN} to operate | |
16599 | on. @xref{Files, ,Commands to specify files}. | |
16600 | ||
16601 | By default, @kbd{M-x gdb} calls the program called @file{gdb}. If you | |
16602 | need to call @value{GDBN} by a different name (for example, if you | |
16603 | keep several configurations around, with different names) you can | |
16604 | customize the Emacs variable @code{gud-gdb-command-name} to run the | |
16605 | one you want. | |
8e04817f AC |
16606 | |
16607 | In the @value{GDBN} I/O buffer, you can use these special Emacs commands in | |
16608 | addition to the standard Shell mode commands: | |
c906108c | 16609 | |
8e04817f AC |
16610 | @table @kbd |
16611 | @item C-h m | |
16612 | Describe the features of Emacs' @value{GDBN} Mode. | |
c906108c | 16613 | |
64fabec2 | 16614 | @item C-c C-s |
8e04817f AC |
16615 | Execute to another source line, like the @value{GDBN} @code{step} command; also |
16616 | update the display window to show the current file and location. | |
c906108c | 16617 | |
64fabec2 | 16618 | @item C-c C-n |
8e04817f AC |
16619 | Execute to next source line in this function, skipping all function |
16620 | calls, like the @value{GDBN} @code{next} command. Then update the display window | |
16621 | to show the current file and location. | |
c906108c | 16622 | |
64fabec2 | 16623 | @item C-c C-i |
8e04817f AC |
16624 | Execute one instruction, like the @value{GDBN} @code{stepi} command; update |
16625 | display window accordingly. | |
c906108c | 16626 | |
8e04817f AC |
16627 | @item C-c C-f |
16628 | Execute until exit from the selected stack frame, like the @value{GDBN} | |
16629 | @code{finish} command. | |
c906108c | 16630 | |
64fabec2 | 16631 | @item C-c C-r |
8e04817f AC |
16632 | Continue execution of your program, like the @value{GDBN} @code{continue} |
16633 | command. | |
b433d00b | 16634 | |
64fabec2 | 16635 | @item C-c < |
8e04817f AC |
16636 | Go up the number of frames indicated by the numeric argument |
16637 | (@pxref{Arguments, , Numeric Arguments, Emacs, The @sc{gnu} Emacs Manual}), | |
16638 | like the @value{GDBN} @code{up} command. | |
b433d00b | 16639 | |
64fabec2 | 16640 | @item C-c > |
8e04817f AC |
16641 | Go down the number of frames indicated by the numeric argument, like the |
16642 | @value{GDBN} @code{down} command. | |
8e04817f | 16643 | @end table |
c906108c | 16644 | |
64fabec2 | 16645 | In any source file, the Emacs command @kbd{C-x SPC} (@code{gud-break}) |
8e04817f | 16646 | tells @value{GDBN} to set a breakpoint on the source line point is on. |
c906108c | 16647 | |
64fabec2 AC |
16648 | If you type @kbd{M-x speedbar}, then Emacs displays a separate frame which |
16649 | shows a backtrace when the @value{GDBN} I/O buffer is current. Move | |
16650 | point to any frame in the stack and type @key{RET} to make it become the | |
16651 | current frame and display the associated source in the source buffer. | |
16652 | Alternatively, click @kbd{Mouse-2} to make the selected frame become the | |
16653 | current one. | |
16654 | ||
8e04817f AC |
16655 | If you accidentally delete the source-display buffer, an easy way to get |
16656 | it back is to type the command @code{f} in the @value{GDBN} buffer, to | |
16657 | request a frame display; when you run under Emacs, this recreates | |
16658 | the source buffer if necessary to show you the context of the current | |
16659 | frame. | |
c906108c | 16660 | |
8e04817f AC |
16661 | The source files displayed in Emacs are in ordinary Emacs buffers |
16662 | which are visiting the source files in the usual way. You can edit | |
16663 | the files with these buffers if you wish; but keep in mind that @value{GDBN} | |
16664 | communicates with Emacs in terms of line numbers. If you add or | |
16665 | delete lines from the text, the line numbers that @value{GDBN} knows cease | |
16666 | to correspond properly with the code. | |
b383017d | 16667 | |
64fabec2 AC |
16668 | The description given here is for GNU Emacs version 21.3 and a more |
16669 | detailed description of its interaction with @value{GDBN} is given in | |
16670 | the Emacs manual (@pxref{Debuggers,,, Emacs, The @sc{gnu} Emacs Manual}). | |
c906108c | 16671 | |
8e04817f AC |
16672 | @c The following dropped because Epoch is nonstandard. Reactivate |
16673 | @c if/when v19 does something similar. ---doc@cygnus.com 19dec1990 | |
16674 | @ignore | |
16675 | @kindex Emacs Epoch environment | |
16676 | @kindex Epoch | |
16677 | @kindex inspect | |
c906108c | 16678 | |
8e04817f AC |
16679 | Version 18 of @sc{gnu} Emacs has a built-in window system |
16680 | called the @code{epoch} | |
16681 | environment. Users of this environment can use a new command, | |
16682 | @code{inspect} which performs identically to @code{print} except that | |
16683 | each value is printed in its own window. | |
16684 | @end ignore | |
c906108c | 16685 | |
922fbb7b AC |
16686 | |
16687 | @node GDB/MI | |
16688 | @chapter The @sc{gdb/mi} Interface | |
16689 | ||
16690 | @unnumberedsec Function and Purpose | |
16691 | ||
16692 | @cindex @sc{gdb/mi}, its purpose | |
6b5e8c01 NR |
16693 | @sc{gdb/mi} is a line based machine oriented text interface to |
16694 | @value{GDBN} and is activated by specifying using the | |
16695 | @option{--interpreter} command line option (@pxref{Mode Options}). It | |
16696 | is specifically intended to support the development of systems which | |
16697 | use the debugger as just one small component of a larger system. | |
922fbb7b AC |
16698 | |
16699 | This chapter is a specification of the @sc{gdb/mi} interface. It is written | |
16700 | in the form of a reference manual. | |
16701 | ||
16702 | Note that @sc{gdb/mi} is still under construction, so some of the | |
16703 | features described below are incomplete and subject to change. | |
16704 | ||
16705 | @unnumberedsec Notation and Terminology | |
16706 | ||
16707 | @cindex notational conventions, for @sc{gdb/mi} | |
16708 | This chapter uses the following notation: | |
16709 | ||
16710 | @itemize @bullet | |
16711 | @item | |
16712 | @code{|} separates two alternatives. | |
16713 | ||
16714 | @item | |
16715 | @code{[ @var{something} ]} indicates that @var{something} is optional: | |
16716 | it may or may not be given. | |
16717 | ||
16718 | @item | |
16719 | @code{( @var{group} )*} means that @var{group} inside the parentheses | |
16720 | may repeat zero or more times. | |
16721 | ||
16722 | @item | |
16723 | @code{( @var{group} )+} means that @var{group} inside the parentheses | |
16724 | may repeat one or more times. | |
16725 | ||
16726 | @item | |
16727 | @code{"@var{string}"} means a literal @var{string}. | |
16728 | @end itemize | |
16729 | ||
16730 | @ignore | |
16731 | @heading Dependencies | |
16732 | @end ignore | |
16733 | ||
16734 | @heading Acknowledgments | |
16735 | ||
16736 | In alphabetic order: Andrew Cagney, Fernando Nasser, Stan Shebs and | |
16737 | Elena Zannoni. | |
16738 | ||
16739 | @menu | |
16740 | * GDB/MI Command Syntax:: | |
16741 | * GDB/MI Compatibility with CLI:: | |
16742 | * GDB/MI Output Records:: | |
16743 | * GDB/MI Command Description Format:: | |
16744 | * GDB/MI Breakpoint Table Commands:: | |
16745 | * GDB/MI Data Manipulation:: | |
16746 | * GDB/MI Program Control:: | |
16747 | * GDB/MI Miscellaneous Commands:: | |
16748 | @ignore | |
16749 | * GDB/MI Kod Commands:: | |
16750 | * GDB/MI Memory Overlay Commands:: | |
16751 | * GDB/MI Signal Handling Commands:: | |
16752 | @end ignore | |
16753 | * GDB/MI Stack Manipulation:: | |
16754 | * GDB/MI Symbol Query:: | |
16755 | * GDB/MI Target Manipulation:: | |
16756 | * GDB/MI Thread Commands:: | |
16757 | * GDB/MI Tracepoint Commands:: | |
16758 | * GDB/MI Variable Objects:: | |
16759 | @end menu | |
16760 | ||
16761 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
16762 | @node GDB/MI Command Syntax | |
16763 | @section @sc{gdb/mi} Command Syntax | |
16764 | ||
16765 | @menu | |
16766 | * GDB/MI Input Syntax:: | |
16767 | * GDB/MI Output Syntax:: | |
16768 | * GDB/MI Simple Examples:: | |
16769 | @end menu | |
16770 | ||
16771 | @node GDB/MI Input Syntax | |
16772 | @subsection @sc{gdb/mi} Input Syntax | |
16773 | ||
16774 | @cindex input syntax for @sc{gdb/mi} | |
16775 | @cindex @sc{gdb/mi}, input syntax | |
16776 | @table @code | |
16777 | @item @var{command} @expansion{} | |
16778 | @code{@var{cli-command} | @var{mi-command}} | |
16779 | ||
16780 | @item @var{cli-command} @expansion{} | |
16781 | @code{[ @var{token} ] @var{cli-command} @var{nl}}, where | |
16782 | @var{cli-command} is any existing @value{GDBN} CLI command. | |
16783 | ||
16784 | @item @var{mi-command} @expansion{} | |
16785 | @code{[ @var{token} ] "-" @var{operation} ( " " @var{option} )* | |
16786 | @code{[} " --" @code{]} ( " " @var{parameter} )* @var{nl}} | |
16787 | ||
16788 | @item @var{token} @expansion{} | |
16789 | "any sequence of digits" | |
16790 | ||
16791 | @item @var{option} @expansion{} | |
16792 | @code{"-" @var{parameter} [ " " @var{parameter} ]} | |
16793 | ||
16794 | @item @var{parameter} @expansion{} | |
16795 | @code{@var{non-blank-sequence} | @var{c-string}} | |
16796 | ||
16797 | @item @var{operation} @expansion{} | |
16798 | @emph{any of the operations described in this chapter} | |
16799 | ||
16800 | @item @var{non-blank-sequence} @expansion{} | |
16801 | @emph{anything, provided it doesn't contain special characters such as | |
16802 | "-", @var{nl}, """ and of course " "} | |
16803 | ||
16804 | @item @var{c-string} @expansion{} | |
16805 | @code{""" @var{seven-bit-iso-c-string-content} """} | |
16806 | ||
16807 | @item @var{nl} @expansion{} | |
16808 | @code{CR | CR-LF} | |
16809 | @end table | |
16810 | ||
16811 | @noindent | |
16812 | Notes: | |
16813 | ||
16814 | @itemize @bullet | |
16815 | @item | |
16816 | The CLI commands are still handled by the @sc{mi} interpreter; their | |
16817 | output is described below. | |
16818 | ||
16819 | @item | |
16820 | The @code{@var{token}}, when present, is passed back when the command | |
16821 | finishes. | |
16822 | ||
16823 | @item | |
16824 | Some @sc{mi} commands accept optional arguments as part of the parameter | |
16825 | list. Each option is identified by a leading @samp{-} (dash) and may be | |
16826 | followed by an optional argument parameter. Options occur first in the | |
16827 | parameter list and can be delimited from normal parameters using | |
16828 | @samp{--} (this is useful when some parameters begin with a dash). | |
16829 | @end itemize | |
16830 | ||
16831 | Pragmatics: | |
16832 | ||
16833 | @itemize @bullet | |
16834 | @item | |
16835 | We want easy access to the existing CLI syntax (for debugging). | |
16836 | ||
16837 | @item | |
16838 | We want it to be easy to spot a @sc{mi} operation. | |
16839 | @end itemize | |
16840 | ||
16841 | @node GDB/MI Output Syntax | |
16842 | @subsection @sc{gdb/mi} Output Syntax | |
16843 | ||
16844 | @cindex output syntax of @sc{gdb/mi} | |
16845 | @cindex @sc{gdb/mi}, output syntax | |
16846 | The output from @sc{gdb/mi} consists of zero or more out-of-band records | |
16847 | followed, optionally, by a single result record. This result record | |
16848 | is for the most recent command. The sequence of output records is | |
16849 | terminated by @samp{(@value{GDBP})}. | |
16850 | ||
16851 | If an input command was prefixed with a @code{@var{token}} then the | |
16852 | corresponding output for that command will also be prefixed by that same | |
16853 | @var{token}. | |
16854 | ||
16855 | @table @code | |
16856 | @item @var{output} @expansion{} | |
f7dc1244 | 16857 | @code{( @var{out-of-band-record} )* [ @var{result-record} ] "(@value{GDBP})" @var{nl}} |
922fbb7b AC |
16858 | |
16859 | @item @var{result-record} @expansion{} | |
16860 | @code{ [ @var{token} ] "^" @var{result-class} ( "," @var{result} )* @var{nl}} | |
16861 | ||
16862 | @item @var{out-of-band-record} @expansion{} | |
16863 | @code{@var{async-record} | @var{stream-record}} | |
16864 | ||
16865 | @item @var{async-record} @expansion{} | |
16866 | @code{@var{exec-async-output} | @var{status-async-output} | @var{notify-async-output}} | |
16867 | ||
16868 | @item @var{exec-async-output} @expansion{} | |
16869 | @code{[ @var{token} ] "*" @var{async-output}} | |
16870 | ||
16871 | @item @var{status-async-output} @expansion{} | |
16872 | @code{[ @var{token} ] "+" @var{async-output}} | |
16873 | ||
16874 | @item @var{notify-async-output} @expansion{} | |
16875 | @code{[ @var{token} ] "=" @var{async-output}} | |
16876 | ||
16877 | @item @var{async-output} @expansion{} | |
16878 | @code{@var{async-class} ( "," @var{result} )* @var{nl}} | |
16879 | ||
16880 | @item @var{result-class} @expansion{} | |
16881 | @code{"done" | "running" | "connected" | "error" | "exit"} | |
16882 | ||
16883 | @item @var{async-class} @expansion{} | |
16884 | @code{"stopped" | @var{others}} (where @var{others} will be added | |
16885 | depending on the needs---this is still in development). | |
16886 | ||
16887 | @item @var{result} @expansion{} | |
16888 | @code{ @var{variable} "=" @var{value}} | |
16889 | ||
16890 | @item @var{variable} @expansion{} | |
16891 | @code{ @var{string} } | |
16892 | ||
16893 | @item @var{value} @expansion{} | |
16894 | @code{ @var{const} | @var{tuple} | @var{list} } | |
16895 | ||
16896 | @item @var{const} @expansion{} | |
16897 | @code{@var{c-string}} | |
16898 | ||
16899 | @item @var{tuple} @expansion{} | |
16900 | @code{ "@{@}" | "@{" @var{result} ( "," @var{result} )* "@}" } | |
16901 | ||
16902 | @item @var{list} @expansion{} | |
16903 | @code{ "[]" | "[" @var{value} ( "," @var{value} )* "]" | "[" | |
16904 | @var{result} ( "," @var{result} )* "]" } | |
16905 | ||
16906 | @item @var{stream-record} @expansion{} | |
16907 | @code{@var{console-stream-output} | @var{target-stream-output} | @var{log-stream-output}} | |
16908 | ||
16909 | @item @var{console-stream-output} @expansion{} | |
16910 | @code{"~" @var{c-string}} | |
16911 | ||
16912 | @item @var{target-stream-output} @expansion{} | |
16913 | @code{"@@" @var{c-string}} | |
16914 | ||
16915 | @item @var{log-stream-output} @expansion{} | |
16916 | @code{"&" @var{c-string}} | |
16917 | ||
16918 | @item @var{nl} @expansion{} | |
16919 | @code{CR | CR-LF} | |
16920 | ||
16921 | @item @var{token} @expansion{} | |
16922 | @emph{any sequence of digits}. | |
16923 | @end table | |
16924 | ||
16925 | @noindent | |
16926 | Notes: | |
16927 | ||
16928 | @itemize @bullet | |
16929 | @item | |
16930 | All output sequences end in a single line containing a period. | |
16931 | ||
16932 | @item | |
16933 | The @code{@var{token}} is from the corresponding request. If an execution | |
16934 | command is interrupted by the @samp{-exec-interrupt} command, the | |
16935 | @var{token} associated with the @samp{*stopped} message is the one of the | |
16936 | original execution command, not the one of the interrupt command. | |
16937 | ||
16938 | @item | |
16939 | @cindex status output in @sc{gdb/mi} | |
16940 | @var{status-async-output} contains on-going status information about the | |
16941 | progress of a slow operation. It can be discarded. All status output is | |
16942 | prefixed by @samp{+}. | |
16943 | ||
16944 | @item | |
16945 | @cindex async output in @sc{gdb/mi} | |
16946 | @var{exec-async-output} contains asynchronous state change on the target | |
16947 | (stopped, started, disappeared). All async output is prefixed by | |
16948 | @samp{*}. | |
16949 | ||
16950 | @item | |
16951 | @cindex notify output in @sc{gdb/mi} | |
16952 | @var{notify-async-output} contains supplementary information that the | |
16953 | client should handle (e.g., a new breakpoint information). All notify | |
16954 | output is prefixed by @samp{=}. | |
16955 | ||
16956 | @item | |
16957 | @cindex console output in @sc{gdb/mi} | |
16958 | @var{console-stream-output} is output that should be displayed as is in the | |
16959 | console. It is the textual response to a CLI command. All the console | |
16960 | output is prefixed by @samp{~}. | |
16961 | ||
16962 | @item | |
16963 | @cindex target output in @sc{gdb/mi} | |
16964 | @var{target-stream-output} is the output produced by the target program. | |
16965 | All the target output is prefixed by @samp{@@}. | |
16966 | ||
16967 | @item | |
16968 | @cindex log output in @sc{gdb/mi} | |
16969 | @var{log-stream-output} is output text coming from @value{GDBN}'s internals, for | |
16970 | instance messages that should be displayed as part of an error log. All | |
16971 | the log output is prefixed by @samp{&}. | |
16972 | ||
16973 | @item | |
16974 | @cindex list output in @sc{gdb/mi} | |
16975 | New @sc{gdb/mi} commands should only output @var{lists} containing | |
16976 | @var{values}. | |
16977 | ||
16978 | ||
16979 | @end itemize | |
16980 | ||
16981 | @xref{GDB/MI Stream Records, , @sc{gdb/mi} Stream Records}, for more | |
16982 | details about the various output records. | |
16983 | ||
16984 | @node GDB/MI Simple Examples | |
16985 | @subsection Simple Examples of @sc{gdb/mi} Interaction | |
16986 | @cindex @sc{gdb/mi}, simple examples | |
16987 | ||
16988 | This subsection presents several simple examples of interaction using | |
16989 | the @sc{gdb/mi} interface. In these examples, @samp{->} means that the | |
16990 | following line is passed to @sc{gdb/mi} as input, while @samp{<-} means | |
16991 | the output received from @sc{gdb/mi}. | |
16992 | ||
16993 | @subsubheading Target Stop | |
16994 | @c Ummm... There is no "-stop" command. This assumes async, no? | |
16995 | Here's an example of stopping the inferior process: | |
16996 | ||
16997 | @smallexample | |
16998 | -> -stop | |
16999 | <- (@value{GDBP}) | |
17000 | @end smallexample | |
17001 | ||
17002 | @noindent | |
17003 | and later: | |
17004 | ||
17005 | @smallexample | |
17006 | <- *stop,reason="stop",address="0x123",source="a.c:123" | |
17007 | <- (@value{GDBP}) | |
17008 | @end smallexample | |
17009 | ||
17010 | @subsubheading Simple CLI Command | |
17011 | ||
17012 | Here's an example of a simple CLI command being passed through | |
17013 | @sc{gdb/mi} and on to the CLI. | |
17014 | ||
17015 | @smallexample | |
17016 | -> print 1+2 | |
17017 | <- &"print 1+2\n" | |
17018 | <- ~"$1 = 3\n" | |
17019 | <- ^done | |
17020 | <- (@value{GDBP}) | |
17021 | @end smallexample | |
17022 | ||
17023 | @subsubheading Command With Side Effects | |
17024 | ||
17025 | @smallexample | |
17026 | -> -symbol-file xyz.exe | |
17027 | <- *breakpoint,nr="3",address="0x123",source="a.c:123" | |
17028 | <- (@value{GDBP}) | |
17029 | @end smallexample | |
17030 | ||
17031 | @subsubheading A Bad Command | |
17032 | ||
17033 | Here's what happens if you pass a non-existent command: | |
17034 | ||
17035 | @smallexample | |
17036 | -> -rubbish | |
17037 | <- ^error,msg="Undefined MI command: rubbish" | |
17038 | <- (@value{GDBP}) | |
17039 | @end smallexample | |
17040 | ||
17041 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17042 | @node GDB/MI Compatibility with CLI | |
17043 | @section @sc{gdb/mi} Compatibility with CLI | |
17044 | ||
17045 | @cindex compatibility, @sc{gdb/mi} and CLI | |
17046 | @cindex @sc{gdb/mi}, compatibility with CLI | |
17047 | To help users familiar with @value{GDBN}'s existing CLI interface, @sc{gdb/mi} | |
17048 | accepts existing CLI commands. As specified by the syntax, such | |
17049 | commands can be directly entered into the @sc{gdb/mi} interface and @value{GDBN} will | |
17050 | respond. | |
17051 | ||
17052 | This mechanism is provided as an aid to developers of @sc{gdb/mi} | |
17053 | clients and not as a reliable interface into the CLI. Since the command | |
17054 | is being interpreteted in an environment that assumes @sc{gdb/mi} | |
17055 | behaviour, the exact output of such commands is likely to end up being | |
17056 | an un-supported hybrid of @sc{gdb/mi} and CLI output. | |
17057 | ||
17058 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17059 | @node GDB/MI Output Records | |
17060 | @section @sc{gdb/mi} Output Records | |
17061 | ||
17062 | @menu | |
17063 | * GDB/MI Result Records:: | |
17064 | * GDB/MI Stream Records:: | |
17065 | * GDB/MI Out-of-band Records:: | |
17066 | @end menu | |
17067 | ||
17068 | @node GDB/MI Result Records | |
17069 | @subsection @sc{gdb/mi} Result Records | |
17070 | ||
17071 | @cindex result records in @sc{gdb/mi} | |
17072 | @cindex @sc{gdb/mi}, result records | |
17073 | In addition to a number of out-of-band notifications, the response to a | |
17074 | @sc{gdb/mi} command includes one of the following result indications: | |
17075 | ||
17076 | @table @code | |
17077 | @findex ^done | |
17078 | @item "^done" [ "," @var{results} ] | |
17079 | The synchronous operation was successful, @code{@var{results}} are the return | |
17080 | values. | |
17081 | ||
17082 | @item "^running" | |
17083 | @findex ^running | |
17084 | @c Is this one correct? Should it be an out-of-band notification? | |
17085 | The asynchronous operation was successfully started. The target is | |
17086 | running. | |
17087 | ||
17088 | @item "^error" "," @var{c-string} | |
17089 | @findex ^error | |
17090 | The operation failed. The @code{@var{c-string}} contains the corresponding | |
17091 | error message. | |
17092 | @end table | |
17093 | ||
17094 | @node GDB/MI Stream Records | |
17095 | @subsection @sc{gdb/mi} Stream Records | |
17096 | ||
17097 | @cindex @sc{gdb/mi}, stream records | |
17098 | @cindex stream records in @sc{gdb/mi} | |
17099 | @value{GDBN} internally maintains a number of output streams: the console, the | |
17100 | target, and the log. The output intended for each of these streams is | |
17101 | funneled through the @sc{gdb/mi} interface using @dfn{stream records}. | |
17102 | ||
17103 | Each stream record begins with a unique @dfn{prefix character} which | |
17104 | identifies its stream (@pxref{GDB/MI Output Syntax, , @sc{gdb/mi} Output | |
17105 | Syntax}). In addition to the prefix, each stream record contains a | |
17106 | @code{@var{string-output}}. This is either raw text (with an implicit new | |
17107 | line) or a quoted C string (which does not contain an implicit newline). | |
17108 | ||
17109 | @table @code | |
17110 | @item "~" @var{string-output} | |
17111 | The console output stream contains text that should be displayed in the | |
17112 | CLI console window. It contains the textual responses to CLI commands. | |
17113 | ||
17114 | @item "@@" @var{string-output} | |
17115 | The target output stream contains any textual output from the running | |
17116 | target. | |
17117 | ||
17118 | @item "&" @var{string-output} | |
17119 | The log stream contains debugging messages being produced by @value{GDBN}'s | |
17120 | internals. | |
17121 | @end table | |
17122 | ||
17123 | @node GDB/MI Out-of-band Records | |
17124 | @subsection @sc{gdb/mi} Out-of-band Records | |
17125 | ||
17126 | @cindex out-of-band records in @sc{gdb/mi} | |
17127 | @cindex @sc{gdb/mi}, out-of-band records | |
17128 | @dfn{Out-of-band} records are used to notify the @sc{gdb/mi} client of | |
17129 | additional changes that have occurred. Those changes can either be a | |
17130 | consequence of @sc{gdb/mi} (e.g., a breakpoint modified) or a result of | |
17131 | target activity (e.g., target stopped). | |
17132 | ||
17133 | The following is a preliminary list of possible out-of-band records. | |
034dad6f | 17134 | In particular, the @var{exec-async-output} records. |
922fbb7b AC |
17135 | |
17136 | @table @code | |
034dad6f BR |
17137 | @item *stopped,reason="@var{reason}" |
17138 | @end table | |
17139 | ||
17140 | @var{reason} can be one of the following: | |
17141 | ||
17142 | @table @code | |
17143 | @item breakpoint-hit | |
17144 | A breakpoint was reached. | |
17145 | @item watchpoint-trigger | |
17146 | A watchpoint was triggered. | |
17147 | @item read-watchpoint-trigger | |
17148 | A read watchpoint was triggered. | |
17149 | @item access-watchpoint-trigger | |
17150 | An access watchpoint was triggered. | |
17151 | @item function-finished | |
17152 | An -exec-finish or similar CLI command was accomplished. | |
17153 | @item location-reached | |
17154 | An -exec-until or similar CLI command was accomplished. | |
17155 | @item watchpoint-scope | |
17156 | A watchpoint has gone out of scope. | |
17157 | @item end-stepping-range | |
17158 | An -exec-next, -exec-next-instruction, -exec-step, -exec-step-instruction or | |
17159 | similar CLI command was accomplished. | |
17160 | @item exited-signalled | |
17161 | The inferior exited because of a signal. | |
17162 | @item exited | |
17163 | The inferior exited. | |
17164 | @item exited-normally | |
17165 | The inferior exited normally. | |
17166 | @item signal-received | |
17167 | A signal was received by the inferior. | |
922fbb7b AC |
17168 | @end table |
17169 | ||
17170 | ||
17171 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17172 | @node GDB/MI Command Description Format | |
17173 | @section @sc{gdb/mi} Command Description Format | |
17174 | ||
17175 | The remaining sections describe blocks of commands. Each block of | |
17176 | commands is laid out in a fashion similar to this section. | |
17177 | ||
17178 | Note the the line breaks shown in the examples are here only for | |
17179 | readability. They don't appear in the real output. | |
17180 | Also note that the commands with a non-available example (N.A.@:) are | |
17181 | not yet implemented. | |
17182 | ||
17183 | @subheading Motivation | |
17184 | ||
17185 | The motivation for this collection of commands. | |
17186 | ||
17187 | @subheading Introduction | |
17188 | ||
17189 | A brief introduction to this collection of commands as a whole. | |
17190 | ||
17191 | @subheading Commands | |
17192 | ||
17193 | For each command in the block, the following is described: | |
17194 | ||
17195 | @subsubheading Synopsis | |
17196 | ||
17197 | @smallexample | |
17198 | -command @var{args}@dots{} | |
17199 | @end smallexample | |
17200 | ||
922fbb7b AC |
17201 | @subsubheading Result |
17202 | ||
265eeb58 | 17203 | @subsubheading @value{GDBN} Command |
922fbb7b | 17204 | |
265eeb58 | 17205 | The corresponding @value{GDBN} CLI command(s), if any. |
922fbb7b AC |
17206 | |
17207 | @subsubheading Example | |
17208 | ||
922fbb7b AC |
17209 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
17210 | @node GDB/MI Breakpoint Table Commands | |
17211 | @section @sc{gdb/mi} Breakpoint table commands | |
17212 | ||
17213 | @cindex breakpoint commands for @sc{gdb/mi} | |
17214 | @cindex @sc{gdb/mi}, breakpoint commands | |
17215 | This section documents @sc{gdb/mi} commands for manipulating | |
17216 | breakpoints. | |
17217 | ||
17218 | @subheading The @code{-break-after} Command | |
17219 | @findex -break-after | |
17220 | ||
17221 | @subsubheading Synopsis | |
17222 | ||
17223 | @smallexample | |
17224 | -break-after @var{number} @var{count} | |
17225 | @end smallexample | |
17226 | ||
17227 | The breakpoint number @var{number} is not in effect until it has been | |
17228 | hit @var{count} times. To see how this is reflected in the output of | |
17229 | the @samp{-break-list} command, see the description of the | |
17230 | @samp{-break-list} command below. | |
17231 | ||
17232 | @subsubheading @value{GDBN} Command | |
17233 | ||
17234 | The corresponding @value{GDBN} command is @samp{ignore}. | |
17235 | ||
17236 | @subsubheading Example | |
17237 | ||
17238 | @smallexample | |
17239 | (@value{GDBP}) | |
17240 | -break-insert main | |
17241 | ^done,bkpt=@{number="1",addr="0x000100d0",file="hello.c",line="5"@} | |
17242 | (@value{GDBP}) | |
17243 | -break-after 1 3 | |
17244 | ~ | |
17245 | ^done | |
17246 | (@value{GDBP}) | |
17247 | -break-list | |
17248 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
17249 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17250 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17251 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17252 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17253 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17254 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17255 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
17256 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0", | |
17257 | ignore="3"@}]@} | |
17258 | (@value{GDBP}) | |
17259 | @end smallexample | |
17260 | ||
17261 | @ignore | |
17262 | @subheading The @code{-break-catch} Command | |
17263 | @findex -break-catch | |
17264 | ||
17265 | @subheading The @code{-break-commands} Command | |
17266 | @findex -break-commands | |
17267 | @end ignore | |
17268 | ||
17269 | ||
17270 | @subheading The @code{-break-condition} Command | |
17271 | @findex -break-condition | |
17272 | ||
17273 | @subsubheading Synopsis | |
17274 | ||
17275 | @smallexample | |
17276 | -break-condition @var{number} @var{expr} | |
17277 | @end smallexample | |
17278 | ||
17279 | Breakpoint @var{number} will stop the program only if the condition in | |
17280 | @var{expr} is true. The condition becomes part of the | |
17281 | @samp{-break-list} output (see the description of the @samp{-break-list} | |
17282 | command below). | |
17283 | ||
17284 | @subsubheading @value{GDBN} Command | |
17285 | ||
17286 | The corresponding @value{GDBN} command is @samp{condition}. | |
17287 | ||
17288 | @subsubheading Example | |
17289 | ||
17290 | @smallexample | |
17291 | (@value{GDBP}) | |
17292 | -break-condition 1 1 | |
17293 | ^done | |
17294 | (@value{GDBP}) | |
17295 | -break-list | |
17296 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
17297 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17298 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17299 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17300 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17301 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17302 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17303 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
17304 | addr="0x000100d0",func="main",file="hello.c",line="5",cond="1", | |
17305 | times="0",ignore="3"@}]@} | |
17306 | (@value{GDBP}) | |
17307 | @end smallexample | |
17308 | ||
17309 | @subheading The @code{-break-delete} Command | |
17310 | @findex -break-delete | |
17311 | ||
17312 | @subsubheading Synopsis | |
17313 | ||
17314 | @smallexample | |
17315 | -break-delete ( @var{breakpoint} )+ | |
17316 | @end smallexample | |
17317 | ||
17318 | Delete the breakpoint(s) whose number(s) are specified in the argument | |
17319 | list. This is obviously reflected in the breakpoint list. | |
17320 | ||
17321 | @subsubheading @value{GDBN} command | |
17322 | ||
17323 | The corresponding @value{GDBN} command is @samp{delete}. | |
17324 | ||
17325 | @subsubheading Example | |
17326 | ||
17327 | @smallexample | |
17328 | (@value{GDBP}) | |
17329 | -break-delete 1 | |
17330 | ^done | |
17331 | (@value{GDBP}) | |
17332 | -break-list | |
17333 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
17334 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17335 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17336 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17337 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17338 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17339 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17340 | body=[]@} | |
17341 | (@value{GDBP}) | |
17342 | @end smallexample | |
17343 | ||
17344 | @subheading The @code{-break-disable} Command | |
17345 | @findex -break-disable | |
17346 | ||
17347 | @subsubheading Synopsis | |
17348 | ||
17349 | @smallexample | |
17350 | -break-disable ( @var{breakpoint} )+ | |
17351 | @end smallexample | |
17352 | ||
17353 | Disable the named @var{breakpoint}(s). The field @samp{enabled} in the | |
17354 | break list is now set to @samp{n} for the named @var{breakpoint}(s). | |
17355 | ||
17356 | @subsubheading @value{GDBN} Command | |
17357 | ||
17358 | The corresponding @value{GDBN} command is @samp{disable}. | |
17359 | ||
17360 | @subsubheading Example | |
17361 | ||
17362 | @smallexample | |
17363 | (@value{GDBP}) | |
17364 | -break-disable 2 | |
17365 | ^done | |
17366 | (@value{GDBP}) | |
17367 | -break-list | |
17368 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
17369 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17370 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17371 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17372 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17373 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17374 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17375 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="n", | |
17376 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}]@} | |
17377 | (@value{GDBP}) | |
17378 | @end smallexample | |
17379 | ||
17380 | @subheading The @code{-break-enable} Command | |
17381 | @findex -break-enable | |
17382 | ||
17383 | @subsubheading Synopsis | |
17384 | ||
17385 | @smallexample | |
17386 | -break-enable ( @var{breakpoint} )+ | |
17387 | @end smallexample | |
17388 | ||
17389 | Enable (previously disabled) @var{breakpoint}(s). | |
17390 | ||
17391 | @subsubheading @value{GDBN} Command | |
17392 | ||
17393 | The corresponding @value{GDBN} command is @samp{enable}. | |
17394 | ||
17395 | @subsubheading Example | |
17396 | ||
17397 | @smallexample | |
17398 | (@value{GDBP}) | |
17399 | -break-enable 2 | |
17400 | ^done | |
17401 | (@value{GDBP}) | |
17402 | -break-list | |
17403 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
17404 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17405 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17406 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17407 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17408 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17409 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17410 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
17411 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}]@} | |
17412 | (@value{GDBP}) | |
17413 | @end smallexample | |
17414 | ||
17415 | @subheading The @code{-break-info} Command | |
17416 | @findex -break-info | |
17417 | ||
17418 | @subsubheading Synopsis | |
17419 | ||
17420 | @smallexample | |
17421 | -break-info @var{breakpoint} | |
17422 | @end smallexample | |
17423 | ||
17424 | @c REDUNDANT??? | |
17425 | Get information about a single breakpoint. | |
17426 | ||
17427 | @subsubheading @value{GDBN} command | |
17428 | ||
17429 | The corresponding @value{GDBN} command is @samp{info break @var{breakpoint}}. | |
17430 | ||
17431 | @subsubheading Example | |
17432 | N.A. | |
17433 | ||
17434 | @subheading The @code{-break-insert} Command | |
17435 | @findex -break-insert | |
17436 | ||
17437 | @subsubheading Synopsis | |
17438 | ||
17439 | @smallexample | |
17440 | -break-insert [ -t ] [ -h ] [ -r ] | |
17441 | [ -c @var{condition} ] [ -i @var{ignore-count} ] | |
17442 | [ -p @var{thread} ] [ @var{line} | @var{addr} ] | |
17443 | @end smallexample | |
17444 | ||
17445 | @noindent | |
17446 | If specified, @var{line}, can be one of: | |
17447 | ||
17448 | @itemize @bullet | |
17449 | @item function | |
17450 | @c @item +offset | |
17451 | @c @item -offset | |
17452 | @c @item linenum | |
17453 | @item filename:linenum | |
17454 | @item filename:function | |
17455 | @item *address | |
17456 | @end itemize | |
17457 | ||
17458 | The possible optional parameters of this command are: | |
17459 | ||
17460 | @table @samp | |
17461 | @item -t | |
17462 | Insert a tempoary breakpoint. | |
17463 | @item -h | |
17464 | Insert a hardware breakpoint. | |
17465 | @item -c @var{condition} | |
17466 | Make the breakpoint conditional on @var{condition}. | |
17467 | @item -i @var{ignore-count} | |
17468 | Initialize the @var{ignore-count}. | |
17469 | @item -r | |
17470 | Insert a regular breakpoint in all the functions whose names match the | |
17471 | given regular expression. Other flags are not applicable to regular | |
17472 | expresson. | |
17473 | @end table | |
17474 | ||
17475 | @subsubheading Result | |
17476 | ||
17477 | The result is in the form: | |
17478 | ||
17479 | @smallexample | |
17480 | ^done,bkptno="@var{number}",func="@var{funcname}", | |
17481 | file="@var{filename}",line="@var{lineno}" | |
17482 | @end smallexample | |
17483 | ||
17484 | @noindent | |
17485 | where @var{number} is the @value{GDBN} number for this breakpoint, @var{funcname} | |
17486 | is the name of the function where the breakpoint was inserted, | |
17487 | @var{filename} is the name of the source file which contains this | |
17488 | function, and @var{lineno} is the source line number within that file. | |
17489 | ||
17490 | Note: this format is open to change. | |
17491 | @c An out-of-band breakpoint instead of part of the result? | |
17492 | ||
17493 | @subsubheading @value{GDBN} Command | |
17494 | ||
17495 | The corresponding @value{GDBN} commands are @samp{break}, @samp{tbreak}, | |
17496 | @samp{hbreak}, @samp{thbreak}, and @samp{rbreak}. | |
17497 | ||
17498 | @subsubheading Example | |
17499 | ||
17500 | @smallexample | |
17501 | (@value{GDBP}) | |
17502 | -break-insert main | |
17503 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@} | |
17504 | (@value{GDBP}) | |
17505 | -break-insert -t foo | |
17506 | ^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c",line="11"@} | |
17507 | (@value{GDBP}) | |
17508 | -break-list | |
17509 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
17510 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17511 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17512 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17513 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17514 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17515 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17516 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
17517 | addr="0x0001072c", func="main",file="recursive2.c",line="4",times="0"@}, | |
17518 | bkpt=@{number="2",type="breakpoint",disp="del",enabled="y", | |
17519 | addr="0x00010774",func="foo",file="recursive2.c",line="11",times="0"@}]@} | |
17520 | (@value{GDBP}) | |
17521 | -break-insert -r foo.* | |
17522 | ~int foo(int, int); | |
17523 | ^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c",line="11"@} | |
17524 | (@value{GDBP}) | |
17525 | @end smallexample | |
17526 | ||
17527 | @subheading The @code{-break-list} Command | |
17528 | @findex -break-list | |
17529 | ||
17530 | @subsubheading Synopsis | |
17531 | ||
17532 | @smallexample | |
17533 | -break-list | |
17534 | @end smallexample | |
17535 | ||
17536 | Displays the list of inserted breakpoints, showing the following fields: | |
17537 | ||
17538 | @table @samp | |
17539 | @item Number | |
17540 | number of the breakpoint | |
17541 | @item Type | |
17542 | type of the breakpoint: @samp{breakpoint} or @samp{watchpoint} | |
17543 | @item Disposition | |
17544 | should the breakpoint be deleted or disabled when it is hit: @samp{keep} | |
17545 | or @samp{nokeep} | |
17546 | @item Enabled | |
17547 | is the breakpoint enabled or no: @samp{y} or @samp{n} | |
17548 | @item Address | |
17549 | memory location at which the breakpoint is set | |
17550 | @item What | |
17551 | logical location of the breakpoint, expressed by function name, file | |
17552 | name, line number | |
17553 | @item Times | |
17554 | number of times the breakpoint has been hit | |
17555 | @end table | |
17556 | ||
17557 | If there are no breakpoints or watchpoints, the @code{BreakpointTable} | |
17558 | @code{body} field is an empty list. | |
17559 | ||
17560 | @subsubheading @value{GDBN} Command | |
17561 | ||
17562 | The corresponding @value{GDBN} command is @samp{info break}. | |
17563 | ||
17564 | @subsubheading Example | |
17565 | ||
17566 | @smallexample | |
17567 | (@value{GDBP}) | |
17568 | -break-list | |
17569 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
17570 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17571 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17572 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17573 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17574 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17575 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17576 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
17577 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}, | |
17578 | bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
17579 | addr="0x00010114",func="foo",file="hello.c",line="13",times="0"@}]@} | |
17580 | (@value{GDBP}) | |
17581 | @end smallexample | |
17582 | ||
17583 | Here's an example of the result when there are no breakpoints: | |
17584 | ||
17585 | @smallexample | |
17586 | (@value{GDBP}) | |
17587 | -break-list | |
17588 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
17589 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17590 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17591 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17592 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17593 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17594 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17595 | body=[]@} | |
17596 | (@value{GDBP}) | |
17597 | @end smallexample | |
17598 | ||
17599 | @subheading The @code{-break-watch} Command | |
17600 | @findex -break-watch | |
17601 | ||
17602 | @subsubheading Synopsis | |
17603 | ||
17604 | @smallexample | |
17605 | -break-watch [ -a | -r ] | |
17606 | @end smallexample | |
17607 | ||
17608 | Create a watchpoint. With the @samp{-a} option it will create an | |
17609 | @dfn{access} watchpoint, i.e. a watchpoint that triggers either on a | |
17610 | read from or on a write to the memory location. With the @samp{-r} | |
17611 | option, the watchpoint created is a @dfn{read} watchpoint, i.e. it will | |
17612 | trigger only when the memory location is accessed for reading. Without | |
17613 | either of the options, the watchpoint created is a regular watchpoint, | |
17614 | i.e. it will trigger when the memory location is accessed for writing. | |
17615 | @xref{Set Watchpoints, , Setting watchpoints}. | |
17616 | ||
17617 | Note that @samp{-break-list} will report a single list of watchpoints and | |
17618 | breakpoints inserted. | |
17619 | ||
17620 | @subsubheading @value{GDBN} Command | |
17621 | ||
17622 | The corresponding @value{GDBN} commands are @samp{watch}, @samp{awatch}, and | |
17623 | @samp{rwatch}. | |
17624 | ||
17625 | @subsubheading Example | |
17626 | ||
17627 | Setting a watchpoint on a variable in the @code{main} function: | |
17628 | ||
17629 | @smallexample | |
17630 | (@value{GDBP}) | |
17631 | -break-watch x | |
17632 | ^done,wpt=@{number="2",exp="x"@} | |
17633 | (@value{GDBP}) | |
17634 | -exec-continue | |
17635 | ^running | |
17636 | ^done,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@}, | |
17637 | value=@{old="-268439212",new="55"@}, | |
76ff342d DJ |
17638 | frame=@{func="main",args=[],file="recursive2.c", |
17639 | fullname="/home/foo/bar/devo/myproject/recursive2.c",line="5"@} | |
922fbb7b AC |
17640 | (@value{GDBP}) |
17641 | @end smallexample | |
17642 | ||
17643 | Setting a watchpoint on a variable local to a function. @value{GDBN} will stop | |
17644 | the program execution twice: first for the variable changing value, then | |
17645 | for the watchpoint going out of scope. | |
17646 | ||
17647 | @smallexample | |
17648 | (@value{GDBP}) | |
17649 | -break-watch C | |
17650 | ^done,wpt=@{number="5",exp="C"@} | |
17651 | (@value{GDBP}) | |
17652 | -exec-continue | |
17653 | ^running | |
17654 | ^done,reason="watchpoint-trigger", | |
17655 | wpt=@{number="5",exp="C"@},value=@{old="-276895068",new="3"@}, | |
17656 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
17657 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
17658 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
922fbb7b AC |
17659 | (@value{GDBP}) |
17660 | -exec-continue | |
17661 | ^running | |
17662 | ^done,reason="watchpoint-scope",wpnum="5", | |
17663 | frame=@{func="callee3",args=[@{name="strarg", | |
17664 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
17665 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
17666 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
922fbb7b AC |
17667 | (@value{GDBP}) |
17668 | @end smallexample | |
17669 | ||
17670 | Listing breakpoints and watchpoints, at different points in the program | |
17671 | execution. Note that once the watchpoint goes out of scope, it is | |
17672 | deleted. | |
17673 | ||
17674 | @smallexample | |
17675 | (@value{GDBP}) | |
17676 | -break-watch C | |
17677 | ^done,wpt=@{number="2",exp="C"@} | |
17678 | (@value{GDBP}) | |
17679 | -break-list | |
17680 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
17681 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17682 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17683 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17684 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17685 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17686 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17687 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
17688 | addr="0x00010734",func="callee4", | |
17689 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}, | |
17690 | bkpt=@{number="2",type="watchpoint",disp="keep", | |
17691 | enabled="y",addr="",what="C",times="0"@}]@} | |
17692 | (@value{GDBP}) | |
17693 | -exec-continue | |
17694 | ^running | |
17695 | ^done,reason="watchpoint-trigger",wpt=@{number="2",exp="C"@}, | |
17696 | value=@{old="-276895068",new="3"@}, | |
17697 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
17698 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
17699 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
922fbb7b AC |
17700 | (@value{GDBP}) |
17701 | -break-list | |
17702 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
17703 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17704 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17705 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17706 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17707 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17708 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17709 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
17710 | addr="0x00010734",func="callee4", | |
17711 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}, | |
17712 | bkpt=@{number="2",type="watchpoint",disp="keep", | |
17713 | enabled="y",addr="",what="C",times="-5"@}]@} | |
17714 | (@value{GDBP}) | |
17715 | -exec-continue | |
17716 | ^running | |
17717 | ^done,reason="watchpoint-scope",wpnum="2", | |
17718 | frame=@{func="callee3",args=[@{name="strarg", | |
17719 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
17720 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
17721 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
922fbb7b AC |
17722 | (@value{GDBP}) |
17723 | -break-list | |
17724 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
17725 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
17726 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
17727 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
17728 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
17729 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
17730 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
17731 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
17732 | addr="0x00010734",func="callee4", | |
17733 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}]@} | |
17734 | (@value{GDBP}) | |
17735 | @end smallexample | |
17736 | ||
17737 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17738 | @node GDB/MI Data Manipulation | |
17739 | @section @sc{gdb/mi} Data Manipulation | |
17740 | ||
17741 | @cindex data manipulation, in @sc{gdb/mi} | |
17742 | @cindex @sc{gdb/mi}, data manipulation | |
17743 | This section describes the @sc{gdb/mi} commands that manipulate data: | |
17744 | examine memory and registers, evaluate expressions, etc. | |
17745 | ||
17746 | @c REMOVED FROM THE INTERFACE. | |
17747 | @c @subheading -data-assign | |
17748 | @c Change the value of a program variable. Plenty of side effects. | |
17749 | @c @subsubheading GDB command | |
17750 | @c set variable | |
17751 | @c @subsubheading Example | |
17752 | @c N.A. | |
17753 | ||
17754 | @subheading The @code{-data-disassemble} Command | |
17755 | @findex -data-disassemble | |
17756 | ||
17757 | @subsubheading Synopsis | |
17758 | ||
17759 | @smallexample | |
17760 | -data-disassemble | |
17761 | [ -s @var{start-addr} -e @var{end-addr} ] | |
17762 | | [ -f @var{filename} -l @var{linenum} [ -n @var{lines} ] ] | |
17763 | -- @var{mode} | |
17764 | @end smallexample | |
17765 | ||
17766 | @noindent | |
17767 | Where: | |
17768 | ||
17769 | @table @samp | |
17770 | @item @var{start-addr} | |
17771 | is the beginning address (or @code{$pc}) | |
17772 | @item @var{end-addr} | |
17773 | is the end address | |
17774 | @item @var{filename} | |
17775 | is the name of the file to disassemble | |
17776 | @item @var{linenum} | |
17777 | is the line number to disassemble around | |
17778 | @item @var{lines} | |
17779 | is the the number of disassembly lines to be produced. If it is -1, | |
17780 | the whole function will be disassembled, in case no @var{end-addr} is | |
17781 | specified. If @var{end-addr} is specified as a non-zero value, and | |
17782 | @var{lines} is lower than the number of disassembly lines between | |
17783 | @var{start-addr} and @var{end-addr}, only @var{lines} lines are | |
17784 | displayed; if @var{lines} is higher than the number of lines between | |
17785 | @var{start-addr} and @var{end-addr}, only the lines up to @var{end-addr} | |
17786 | are displayed. | |
17787 | @item @var{mode} | |
17788 | is either 0 (meaning only disassembly) or 1 (meaning mixed source and | |
17789 | disassembly). | |
17790 | @end table | |
17791 | ||
17792 | @subsubheading Result | |
17793 | ||
17794 | The output for each instruction is composed of four fields: | |
17795 | ||
17796 | @itemize @bullet | |
17797 | @item Address | |
17798 | @item Func-name | |
17799 | @item Offset | |
17800 | @item Instruction | |
17801 | @end itemize | |
17802 | ||
17803 | Note that whatever included in the instruction field, is not manipulated | |
17804 | directely by @sc{gdb/mi}, i.e. it is not possible to adjust its format. | |
17805 | ||
17806 | @subsubheading @value{GDBN} Command | |
17807 | ||
17808 | There's no direct mapping from this command to the CLI. | |
17809 | ||
17810 | @subsubheading Example | |
17811 | ||
17812 | Disassemble from the current value of @code{$pc} to @code{$pc + 20}: | |
17813 | ||
17814 | @smallexample | |
17815 | (@value{GDBP}) | |
17816 | -data-disassemble -s $pc -e "$pc + 20" -- 0 | |
17817 | ^done, | |
17818 | asm_insns=[ | |
17819 | @{address="0x000107c0",func-name="main",offset="4", | |
17820 | inst="mov 2, %o0"@}, | |
17821 | @{address="0x000107c4",func-name="main",offset="8", | |
17822 | inst="sethi %hi(0x11800), %o2"@}, | |
17823 | @{address="0x000107c8",func-name="main",offset="12", | |
17824 | inst="or %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"@}, | |
17825 | @{address="0x000107cc",func-name="main",offset="16", | |
17826 | inst="sethi %hi(0x11800), %o2"@}, | |
17827 | @{address="0x000107d0",func-name="main",offset="20", | |
17828 | inst="or %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"@}] | |
17829 | (@value{GDBP}) | |
17830 | @end smallexample | |
17831 | ||
17832 | Disassemble the whole @code{main} function. Line 32 is part of | |
17833 | @code{main}. | |
17834 | ||
17835 | @smallexample | |
17836 | -data-disassemble -f basics.c -l 32 -- 0 | |
17837 | ^done,asm_insns=[ | |
17838 | @{address="0x000107bc",func-name="main",offset="0", | |
17839 | inst="save %sp, -112, %sp"@}, | |
17840 | @{address="0x000107c0",func-name="main",offset="4", | |
17841 | inst="mov 2, %o0"@}, | |
17842 | @{address="0x000107c4",func-name="main",offset="8", | |
17843 | inst="sethi %hi(0x11800), %o2"@}, | |
17844 | [@dots{}] | |
17845 | @{address="0x0001081c",func-name="main",offset="96",inst="ret "@}, | |
17846 | @{address="0x00010820",func-name="main",offset="100",inst="restore "@}] | |
17847 | (@value{GDBP}) | |
17848 | @end smallexample | |
17849 | ||
17850 | Disassemble 3 instructions from the start of @code{main}: | |
17851 | ||
17852 | @smallexample | |
17853 | (@value{GDBP}) | |
17854 | -data-disassemble -f basics.c -l 32 -n 3 -- 0 | |
17855 | ^done,asm_insns=[ | |
17856 | @{address="0x000107bc",func-name="main",offset="0", | |
17857 | inst="save %sp, -112, %sp"@}, | |
17858 | @{address="0x000107c0",func-name="main",offset="4", | |
17859 | inst="mov 2, %o0"@}, | |
17860 | @{address="0x000107c4",func-name="main",offset="8", | |
17861 | inst="sethi %hi(0x11800), %o2"@}] | |
17862 | (@value{GDBP}) | |
17863 | @end smallexample | |
17864 | ||
17865 | Disassemble 3 instructions from the start of @code{main} in mixed mode: | |
17866 | ||
17867 | @smallexample | |
17868 | (@value{GDBP}) | |
17869 | -data-disassemble -f basics.c -l 32 -n 3 -- 1 | |
17870 | ^done,asm_insns=[ | |
17871 | src_and_asm_line=@{line="31", | |
17872 | file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \ | |
17873 | testsuite/gdb.mi/basics.c",line_asm_insn=[ | |
17874 | @{address="0x000107bc",func-name="main",offset="0", | |
17875 | inst="save %sp, -112, %sp"@}]@}, | |
17876 | src_and_asm_line=@{line="32", | |
17877 | file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \ | |
17878 | testsuite/gdb.mi/basics.c",line_asm_insn=[ | |
17879 | @{address="0x000107c0",func-name="main",offset="4", | |
17880 | inst="mov 2, %o0"@}, | |
17881 | @{address="0x000107c4",func-name="main",offset="8", | |
17882 | inst="sethi %hi(0x11800), %o2"@}]@}] | |
17883 | (@value{GDBP}) | |
17884 | @end smallexample | |
17885 | ||
17886 | ||
17887 | @subheading The @code{-data-evaluate-expression} Command | |
17888 | @findex -data-evaluate-expression | |
17889 | ||
17890 | @subsubheading Synopsis | |
17891 | ||
17892 | @smallexample | |
17893 | -data-evaluate-expression @var{expr} | |
17894 | @end smallexample | |
17895 | ||
17896 | Evaluate @var{expr} as an expression. The expression could contain an | |
17897 | inferior function call. The function call will execute synchronously. | |
17898 | If the expression contains spaces, it must be enclosed in double quotes. | |
17899 | ||
17900 | @subsubheading @value{GDBN} Command | |
17901 | ||
17902 | The corresponding @value{GDBN} commands are @samp{print}, @samp{output}, and | |
17903 | @samp{call}. In @code{gdbtk} only, there's a corresponding | |
17904 | @samp{gdb_eval} command. | |
17905 | ||
17906 | @subsubheading Example | |
17907 | ||
17908 | In the following example, the numbers that precede the commands are the | |
17909 | @dfn{tokens} described in @ref{GDB/MI Command Syntax, ,@sc{gdb/mi} | |
17910 | Command Syntax}. Notice how @sc{gdb/mi} returns the same tokens in its | |
17911 | output. | |
17912 | ||
17913 | @smallexample | |
17914 | 211-data-evaluate-expression A | |
17915 | 211^done,value="1" | |
17916 | (@value{GDBP}) | |
17917 | 311-data-evaluate-expression &A | |
17918 | 311^done,value="0xefffeb7c" | |
17919 | (@value{GDBP}) | |
17920 | 411-data-evaluate-expression A+3 | |
17921 | 411^done,value="4" | |
17922 | (@value{GDBP}) | |
17923 | 511-data-evaluate-expression "A + 3" | |
17924 | 511^done,value="4" | |
17925 | (@value{GDBP}) | |
17926 | @end smallexample | |
17927 | ||
17928 | ||
17929 | @subheading The @code{-data-list-changed-registers} Command | |
17930 | @findex -data-list-changed-registers | |
17931 | ||
17932 | @subsubheading Synopsis | |
17933 | ||
17934 | @smallexample | |
17935 | -data-list-changed-registers | |
17936 | @end smallexample | |
17937 | ||
17938 | Display a list of the registers that have changed. | |
17939 | ||
17940 | @subsubheading @value{GDBN} Command | |
17941 | ||
17942 | @value{GDBN} doesn't have a direct analog for this command; @code{gdbtk} | |
17943 | has the corresponding command @samp{gdb_changed_register_list}. | |
17944 | ||
17945 | @subsubheading Example | |
17946 | ||
17947 | On a PPC MBX board: | |
17948 | ||
17949 | @smallexample | |
17950 | (@value{GDBP}) | |
17951 | -exec-continue | |
17952 | ^running | |
17953 | ||
17954 | (@value{GDBP}) | |
17955 | *stopped,reason="breakpoint-hit",bkptno="1",frame=@{func="main", | |
76ff342d | 17956 | args=[],file="try.c",fullname="/home/foo/bar/devo/myproject/try.c",line="5"@} |
922fbb7b AC |
17957 | (@value{GDBP}) |
17958 | -data-list-changed-registers | |
17959 | ^done,changed-registers=["0","1","2","4","5","6","7","8","9", | |
17960 | "10","11","13","14","15","16","17","18","19","20","21","22","23", | |
17961 | "24","25","26","27","28","30","31","64","65","66","67","69"] | |
17962 | (@value{GDBP}) | |
17963 | @end smallexample | |
17964 | ||
17965 | ||
17966 | @subheading The @code{-data-list-register-names} Command | |
17967 | @findex -data-list-register-names | |
17968 | ||
17969 | @subsubheading Synopsis | |
17970 | ||
17971 | @smallexample | |
17972 | -data-list-register-names [ ( @var{regno} )+ ] | |
17973 | @end smallexample | |
17974 | ||
17975 | Show a list of register names for the current target. If no arguments | |
17976 | are given, it shows a list of the names of all the registers. If | |
17977 | integer numbers are given as arguments, it will print a list of the | |
17978 | names of the registers corresponding to the arguments. To ensure | |
17979 | consistency between a register name and its number, the output list may | |
17980 | include empty register names. | |
17981 | ||
17982 | @subsubheading @value{GDBN} Command | |
17983 | ||
17984 | @value{GDBN} does not have a command which corresponds to | |
17985 | @samp{-data-list-register-names}. In @code{gdbtk} there is a | |
17986 | corresponding command @samp{gdb_regnames}. | |
17987 | ||
17988 | @subsubheading Example | |
17989 | ||
17990 | For the PPC MBX board: | |
17991 | @smallexample | |
17992 | (@value{GDBP}) | |
17993 | -data-list-register-names | |
17994 | ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7", | |
17995 | "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18", | |
17996 | "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29", | |
17997 | "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9", | |
17998 | "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20", | |
17999 | "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31", | |
18000 | "", "pc","ps","cr","lr","ctr","xer"] | |
18001 | (@value{GDBP}) | |
18002 | -data-list-register-names 1 2 3 | |
18003 | ^done,register-names=["r1","r2","r3"] | |
18004 | (@value{GDBP}) | |
18005 | @end smallexample | |
18006 | ||
18007 | @subheading The @code{-data-list-register-values} Command | |
18008 | @findex -data-list-register-values | |
18009 | ||
18010 | @subsubheading Synopsis | |
18011 | ||
18012 | @smallexample | |
18013 | -data-list-register-values @var{fmt} [ ( @var{regno} )*] | |
18014 | @end smallexample | |
18015 | ||
18016 | Display the registers' contents. @var{fmt} is the format according to | |
18017 | which the registers' contents are to be returned, followed by an optional | |
18018 | list of numbers specifying the registers to display. A missing list of | |
18019 | numbers indicates that the contents of all the registers must be returned. | |
18020 | ||
18021 | Allowed formats for @var{fmt} are: | |
18022 | ||
18023 | @table @code | |
18024 | @item x | |
18025 | Hexadecimal | |
18026 | @item o | |
18027 | Octal | |
18028 | @item t | |
18029 | Binary | |
18030 | @item d | |
18031 | Decimal | |
18032 | @item r | |
18033 | Raw | |
18034 | @item N | |
18035 | Natural | |
18036 | @end table | |
18037 | ||
18038 | @subsubheading @value{GDBN} Command | |
18039 | ||
18040 | The corresponding @value{GDBN} commands are @samp{info reg}, @samp{info | |
18041 | all-reg}, and (in @code{gdbtk}) @samp{gdb_fetch_registers}. | |
18042 | ||
18043 | @subsubheading Example | |
18044 | ||
18045 | For a PPC MBX board (note: line breaks are for readability only, they | |
18046 | don't appear in the actual output): | |
18047 | ||
18048 | @smallexample | |
18049 | (@value{GDBP}) | |
18050 | -data-list-register-values r 64 65 | |
18051 | ^done,register-values=[@{number="64",value="0xfe00a300"@}, | |
18052 | @{number="65",value="0x00029002"@}] | |
18053 | (@value{GDBP}) | |
18054 | -data-list-register-values x | |
18055 | ^done,register-values=[@{number="0",value="0xfe0043c8"@}, | |
18056 | @{number="1",value="0x3fff88"@},@{number="2",value="0xfffffffe"@}, | |
18057 | @{number="3",value="0x0"@},@{number="4",value="0xa"@}, | |
18058 | @{number="5",value="0x3fff68"@},@{number="6",value="0x3fff58"@}, | |
18059 | @{number="7",value="0xfe011e98"@},@{number="8",value="0x2"@}, | |
18060 | @{number="9",value="0xfa202820"@},@{number="10",value="0xfa202808"@}, | |
18061 | @{number="11",value="0x1"@},@{number="12",value="0x0"@}, | |
18062 | @{number="13",value="0x4544"@},@{number="14",value="0xffdfffff"@}, | |
18063 | @{number="15",value="0xffffffff"@},@{number="16",value="0xfffffeff"@}, | |
18064 | @{number="17",value="0xefffffed"@},@{number="18",value="0xfffffffe"@}, | |
18065 | @{number="19",value="0xffffffff"@},@{number="20",value="0xffffffff"@}, | |
18066 | @{number="21",value="0xffffffff"@},@{number="22",value="0xfffffff7"@}, | |
18067 | @{number="23",value="0xffffffff"@},@{number="24",value="0xffffffff"@}, | |
18068 | @{number="25",value="0xffffffff"@},@{number="26",value="0xfffffffb"@}, | |
18069 | @{number="27",value="0xffffffff"@},@{number="28",value="0xf7bfffff"@}, | |
18070 | @{number="29",value="0x0"@},@{number="30",value="0xfe010000"@}, | |
18071 | @{number="31",value="0x0"@},@{number="32",value="0x0"@}, | |
18072 | @{number="33",value="0x0"@},@{number="34",value="0x0"@}, | |
18073 | @{number="35",value="0x0"@},@{number="36",value="0x0"@}, | |
18074 | @{number="37",value="0x0"@},@{number="38",value="0x0"@}, | |
18075 | @{number="39",value="0x0"@},@{number="40",value="0x0"@}, | |
18076 | @{number="41",value="0x0"@},@{number="42",value="0x0"@}, | |
18077 | @{number="43",value="0x0"@},@{number="44",value="0x0"@}, | |
18078 | @{number="45",value="0x0"@},@{number="46",value="0x0"@}, | |
18079 | @{number="47",value="0x0"@},@{number="48",value="0x0"@}, | |
18080 | @{number="49",value="0x0"@},@{number="50",value="0x0"@}, | |
18081 | @{number="51",value="0x0"@},@{number="52",value="0x0"@}, | |
18082 | @{number="53",value="0x0"@},@{number="54",value="0x0"@}, | |
18083 | @{number="55",value="0x0"@},@{number="56",value="0x0"@}, | |
18084 | @{number="57",value="0x0"@},@{number="58",value="0x0"@}, | |
18085 | @{number="59",value="0x0"@},@{number="60",value="0x0"@}, | |
18086 | @{number="61",value="0x0"@},@{number="62",value="0x0"@}, | |
18087 | @{number="63",value="0x0"@},@{number="64",value="0xfe00a300"@}, | |
18088 | @{number="65",value="0x29002"@},@{number="66",value="0x202f04b5"@}, | |
18089 | @{number="67",value="0xfe0043b0"@},@{number="68",value="0xfe00b3e4"@}, | |
18090 | @{number="69",value="0x20002b03"@}] | |
18091 | (@value{GDBP}) | |
18092 | @end smallexample | |
18093 | ||
18094 | ||
18095 | @subheading The @code{-data-read-memory} Command | |
18096 | @findex -data-read-memory | |
18097 | ||
18098 | @subsubheading Synopsis | |
18099 | ||
18100 | @smallexample | |
18101 | -data-read-memory [ -o @var{byte-offset} ] | |
18102 | @var{address} @var{word-format} @var{word-size} | |
18103 | @var{nr-rows} @var{nr-cols} [ @var{aschar} ] | |
18104 | @end smallexample | |
18105 | ||
18106 | @noindent | |
18107 | where: | |
18108 | ||
18109 | @table @samp | |
18110 | @item @var{address} | |
18111 | An expression specifying the address of the first memory word to be | |
18112 | read. Complex expressions containing embedded white space should be | |
18113 | quoted using the C convention. | |
18114 | ||
18115 | @item @var{word-format} | |
18116 | The format to be used to print the memory words. The notation is the | |
18117 | same as for @value{GDBN}'s @code{print} command (@pxref{Output Formats, | |
18118 | ,Output formats}). | |
18119 | ||
18120 | @item @var{word-size} | |
18121 | The size of each memory word in bytes. | |
18122 | ||
18123 | @item @var{nr-rows} | |
18124 | The number of rows in the output table. | |
18125 | ||
18126 | @item @var{nr-cols} | |
18127 | The number of columns in the output table. | |
18128 | ||
18129 | @item @var{aschar} | |
18130 | If present, indicates that each row should include an @sc{ascii} dump. The | |
18131 | value of @var{aschar} is used as a padding character when a byte is not a | |
18132 | member of the printable @sc{ascii} character set (printable @sc{ascii} | |
18133 | characters are those whose code is between 32 and 126, inclusively). | |
18134 | ||
18135 | @item @var{byte-offset} | |
18136 | An offset to add to the @var{address} before fetching memory. | |
18137 | @end table | |
18138 | ||
18139 | This command displays memory contents as a table of @var{nr-rows} by | |
18140 | @var{nr-cols} words, each word being @var{word-size} bytes. In total, | |
18141 | @code{@var{nr-rows} * @var{nr-cols} * @var{word-size}} bytes are read | |
18142 | (returned as @samp{total-bytes}). Should less than the requested number | |
18143 | of bytes be returned by the target, the missing words are identified | |
18144 | using @samp{N/A}. The number of bytes read from the target is returned | |
18145 | in @samp{nr-bytes} and the starting address used to read memory in | |
18146 | @samp{addr}. | |
18147 | ||
18148 | The address of the next/previous row or page is available in | |
18149 | @samp{next-row} and @samp{prev-row}, @samp{next-page} and | |
18150 | @samp{prev-page}. | |
18151 | ||
18152 | @subsubheading @value{GDBN} Command | |
18153 | ||
18154 | The corresponding @value{GDBN} command is @samp{x}. @code{gdbtk} has | |
18155 | @samp{gdb_get_mem} memory read command. | |
18156 | ||
18157 | @subsubheading Example | |
18158 | ||
18159 | Read six bytes of memory starting at @code{bytes+6} but then offset by | |
18160 | @code{-6} bytes. Format as three rows of two columns. One byte per | |
18161 | word. Display each word in hex. | |
18162 | ||
18163 | @smallexample | |
18164 | (@value{GDBP}) | |
18165 | 9-data-read-memory -o -6 -- bytes+6 x 1 3 2 | |
18166 | 9^done,addr="0x00001390",nr-bytes="6",total-bytes="6", | |
18167 | next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396", | |
18168 | prev-page="0x0000138a",memory=[ | |
18169 | @{addr="0x00001390",data=["0x00","0x01"]@}, | |
18170 | @{addr="0x00001392",data=["0x02","0x03"]@}, | |
18171 | @{addr="0x00001394",data=["0x04","0x05"]@}] | |
18172 | (@value{GDBP}) | |
18173 | @end smallexample | |
18174 | ||
18175 | Read two bytes of memory starting at address @code{shorts + 64} and | |
18176 | display as a single word formatted in decimal. | |
18177 | ||
18178 | @smallexample | |
18179 | (@value{GDBP}) | |
18180 | 5-data-read-memory shorts+64 d 2 1 1 | |
18181 | 5^done,addr="0x00001510",nr-bytes="2",total-bytes="2", | |
18182 | next-row="0x00001512",prev-row="0x0000150e", | |
18183 | next-page="0x00001512",prev-page="0x0000150e",memory=[ | |
18184 | @{addr="0x00001510",data=["128"]@}] | |
18185 | (@value{GDBP}) | |
18186 | @end smallexample | |
18187 | ||
18188 | Read thirty two bytes of memory starting at @code{bytes+16} and format | |
18189 | as eight rows of four columns. Include a string encoding with @samp{x} | |
18190 | used as the non-printable character. | |
18191 | ||
18192 | @smallexample | |
18193 | (@value{GDBP}) | |
18194 | 4-data-read-memory bytes+16 x 1 8 4 x | |
18195 | 4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32", | |
18196 | next-row="0x000013c0",prev-row="0x0000139c", | |
18197 | next-page="0x000013c0",prev-page="0x00001380",memory=[ | |
18198 | @{addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"@}, | |
18199 | @{addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"@}, | |
18200 | @{addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"@}, | |
18201 | @{addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"@}, | |
18202 | @{addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"@}, | |
18203 | @{addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"@}, | |
18204 | @{addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"@}, | |
18205 | @{addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"@}] | |
18206 | (@value{GDBP}) | |
18207 | @end smallexample | |
18208 | ||
18209 | @subheading The @code{-display-delete} Command | |
18210 | @findex -display-delete | |
18211 | ||
18212 | @subsubheading Synopsis | |
18213 | ||
18214 | @smallexample | |
18215 | -display-delete @var{number} | |
18216 | @end smallexample | |
18217 | ||
18218 | Delete the display @var{number}. | |
18219 | ||
18220 | @subsubheading @value{GDBN} Command | |
18221 | ||
18222 | The corresponding @value{GDBN} command is @samp{delete display}. | |
18223 | ||
18224 | @subsubheading Example | |
18225 | N.A. | |
18226 | ||
18227 | ||
18228 | @subheading The @code{-display-disable} Command | |
18229 | @findex -display-disable | |
18230 | ||
18231 | @subsubheading Synopsis | |
18232 | ||
18233 | @smallexample | |
18234 | -display-disable @var{number} | |
18235 | @end smallexample | |
18236 | ||
18237 | Disable display @var{number}. | |
18238 | ||
18239 | @subsubheading @value{GDBN} Command | |
18240 | ||
18241 | The corresponding @value{GDBN} command is @samp{disable display}. | |
18242 | ||
18243 | @subsubheading Example | |
18244 | N.A. | |
18245 | ||
18246 | ||
18247 | @subheading The @code{-display-enable} Command | |
18248 | @findex -display-enable | |
18249 | ||
18250 | @subsubheading Synopsis | |
18251 | ||
18252 | @smallexample | |
18253 | -display-enable @var{number} | |
18254 | @end smallexample | |
18255 | ||
18256 | Enable display @var{number}. | |
18257 | ||
18258 | @subsubheading @value{GDBN} Command | |
18259 | ||
18260 | The corresponding @value{GDBN} command is @samp{enable display}. | |
18261 | ||
18262 | @subsubheading Example | |
18263 | N.A. | |
18264 | ||
18265 | ||
18266 | @subheading The @code{-display-insert} Command | |
18267 | @findex -display-insert | |
18268 | ||
18269 | @subsubheading Synopsis | |
18270 | ||
18271 | @smallexample | |
18272 | -display-insert @var{expression} | |
18273 | @end smallexample | |
18274 | ||
18275 | Display @var{expression} every time the program stops. | |
18276 | ||
18277 | @subsubheading @value{GDBN} Command | |
18278 | ||
18279 | The corresponding @value{GDBN} command is @samp{display}. | |
18280 | ||
18281 | @subsubheading Example | |
18282 | N.A. | |
18283 | ||
18284 | ||
18285 | @subheading The @code{-display-list} Command | |
18286 | @findex -display-list | |
18287 | ||
18288 | @subsubheading Synopsis | |
18289 | ||
18290 | @smallexample | |
18291 | -display-list | |
18292 | @end smallexample | |
18293 | ||
18294 | List the displays. Do not show the current values. | |
18295 | ||
18296 | @subsubheading @value{GDBN} Command | |
18297 | ||
18298 | The corresponding @value{GDBN} command is @samp{info display}. | |
18299 | ||
18300 | @subsubheading Example | |
18301 | N.A. | |
18302 | ||
18303 | ||
18304 | @subheading The @code{-environment-cd} Command | |
18305 | @findex -environment-cd | |
18306 | ||
18307 | @subsubheading Synopsis | |
18308 | ||
18309 | @smallexample | |
18310 | -environment-cd @var{pathdir} | |
18311 | @end smallexample | |
18312 | ||
18313 | Set @value{GDBN}'s working directory. | |
18314 | ||
18315 | @subsubheading @value{GDBN} Command | |
18316 | ||
18317 | The corresponding @value{GDBN} command is @samp{cd}. | |
18318 | ||
18319 | @subsubheading Example | |
18320 | ||
18321 | @smallexample | |
18322 | (@value{GDBP}) | |
18323 | -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb | |
18324 | ^done | |
18325 | (@value{GDBP}) | |
18326 | @end smallexample | |
18327 | ||
18328 | ||
18329 | @subheading The @code{-environment-directory} Command | |
18330 | @findex -environment-directory | |
18331 | ||
18332 | @subsubheading Synopsis | |
18333 | ||
18334 | @smallexample | |
18335 | -environment-directory [ -r ] [ @var{pathdir} ]+ | |
18336 | @end smallexample | |
18337 | ||
18338 | Add directories @var{pathdir} to beginning of search path for source files. | |
18339 | If the @samp{-r} option is used, the search path is reset to the default | |
b383017d | 18340 | search path. If directories @var{pathdir} are supplied in addition to the |
922fbb7b AC |
18341 | @samp{-r} option, the search path is first reset and then addition |
18342 | occurs as normal. | |
b383017d | 18343 | Multiple directories may be specified, separated by blanks. Specifying |
922fbb7b AC |
18344 | multiple directories in a single command |
18345 | results in the directories added to the beginning of the | |
18346 | search path in the same order they were presented in the command. | |
18347 | If blanks are needed as | |
18348 | part of a directory name, double-quotes should be used around | |
18349 | the name. In the command output, the path will show up separated | |
b383017d | 18350 | by the system directory-separator character. The directory-seperator |
922fbb7b AC |
18351 | character must not be used |
18352 | in any directory name. | |
18353 | If no directories are specified, the current search path is displayed. | |
18354 | ||
18355 | @subsubheading @value{GDBN} Command | |
18356 | ||
18357 | The corresponding @value{GDBN} command is @samp{dir}. | |
18358 | ||
18359 | @subsubheading Example | |
18360 | ||
18361 | @smallexample | |
18362 | (@value{GDBP}) | |
18363 | -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb | |
18364 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
18365 | (@value{GDBP}) | |
18366 | -environment-directory "" | |
18367 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
18368 | (@value{GDBP}) | |
18369 | -environment-directory -r /home/jjohnstn/src/gdb /usr/src | |
18370 | ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd" | |
18371 | (@value{GDBP}) | |
18372 | -environment-directory -r | |
18373 | ^done,source-path="$cdir:$cwd" | |
18374 | (@value{GDBP}) | |
18375 | @end smallexample | |
18376 | ||
18377 | ||
18378 | @subheading The @code{-environment-path} Command | |
18379 | @findex -environment-path | |
18380 | ||
18381 | @subsubheading Synopsis | |
18382 | ||
18383 | @smallexample | |
18384 | -environment-path [ -r ] [ @var{pathdir} ]+ | |
18385 | @end smallexample | |
18386 | ||
18387 | Add directories @var{pathdir} to beginning of search path for object files. | |
18388 | If the @samp{-r} option is used, the search path is reset to the original | |
b383017d RM |
18389 | search path that existed at gdb start-up. If directories @var{pathdir} are |
18390 | supplied in addition to the | |
922fbb7b AC |
18391 | @samp{-r} option, the search path is first reset and then addition |
18392 | occurs as normal. | |
b383017d | 18393 | Multiple directories may be specified, separated by blanks. Specifying |
922fbb7b AC |
18394 | multiple directories in a single command |
18395 | results in the directories added to the beginning of the | |
18396 | search path in the same order they were presented in the command. | |
18397 | If blanks are needed as | |
18398 | part of a directory name, double-quotes should be used around | |
18399 | the name. In the command output, the path will show up separated | |
b383017d | 18400 | by the system directory-separator character. The directory-seperator |
922fbb7b AC |
18401 | character must not be used |
18402 | in any directory name. | |
18403 | If no directories are specified, the current path is displayed. | |
18404 | ||
18405 | ||
18406 | @subsubheading @value{GDBN} Command | |
18407 | ||
18408 | The corresponding @value{GDBN} command is @samp{path}. | |
18409 | ||
18410 | @subsubheading Example | |
18411 | ||
18412 | @smallexample | |
18413 | (@value{GDBP}) | |
b383017d | 18414 | -environment-path |
922fbb7b AC |
18415 | ^done,path="/usr/bin" |
18416 | (@value{GDBP}) | |
18417 | -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin | |
18418 | ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin" | |
18419 | (@value{GDBP}) | |
18420 | -environment-path -r /usr/local/bin | |
18421 | ^done,path="/usr/local/bin:/usr/bin" | |
18422 | (@value{GDBP}) | |
18423 | @end smallexample | |
18424 | ||
18425 | ||
18426 | @subheading The @code{-environment-pwd} Command | |
18427 | @findex -environment-pwd | |
18428 | ||
18429 | @subsubheading Synopsis | |
18430 | ||
18431 | @smallexample | |
18432 | -environment-pwd | |
18433 | @end smallexample | |
18434 | ||
18435 | Show the current working directory. | |
18436 | ||
18437 | @subsubheading @value{GDBN} command | |
18438 | ||
18439 | The corresponding @value{GDBN} command is @samp{pwd}. | |
18440 | ||
18441 | @subsubheading Example | |
18442 | ||
18443 | @smallexample | |
18444 | (@value{GDBP}) | |
18445 | -environment-pwd | |
18446 | ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb" | |
18447 | (@value{GDBP}) | |
18448 | @end smallexample | |
18449 | ||
18450 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
18451 | @node GDB/MI Program Control | |
18452 | @section @sc{gdb/mi} Program control | |
18453 | ||
18454 | @subsubheading Program termination | |
18455 | ||
18456 | As a result of execution, the inferior program can run to completion, if | |
18457 | it doesn't encounter any breakpoints. In this case the output will | |
18458 | include an exit code, if the program has exited exceptionally. | |
18459 | ||
18460 | @subsubheading Examples | |
18461 | ||
18462 | @noindent | |
18463 | Program exited normally: | |
18464 | ||
18465 | @smallexample | |
18466 | (@value{GDBP}) | |
18467 | -exec-run | |
18468 | ^running | |
18469 | (@value{GDBP}) | |
18470 | x = 55 | |
18471 | *stopped,reason="exited-normally" | |
18472 | (@value{GDBP}) | |
18473 | @end smallexample | |
18474 | ||
18475 | @noindent | |
18476 | Program exited exceptionally: | |
18477 | ||
18478 | @smallexample | |
18479 | (@value{GDBP}) | |
18480 | -exec-run | |
18481 | ^running | |
18482 | (@value{GDBP}) | |
18483 | x = 55 | |
18484 | *stopped,reason="exited",exit-code="01" | |
18485 | (@value{GDBP}) | |
18486 | @end smallexample | |
18487 | ||
18488 | Another way the program can terminate is if it receives a signal such as | |
18489 | @code{SIGINT}. In this case, @sc{gdb/mi} displays this: | |
18490 | ||
18491 | @smallexample | |
18492 | (@value{GDBP}) | |
18493 | *stopped,reason="exited-signalled",signal-name="SIGINT", | |
18494 | signal-meaning="Interrupt" | |
18495 | @end smallexample | |
18496 | ||
18497 | ||
18498 | @subheading The @code{-exec-abort} Command | |
18499 | @findex -exec-abort | |
18500 | ||
18501 | @subsubheading Synopsis | |
18502 | ||
18503 | @smallexample | |
18504 | -exec-abort | |
18505 | @end smallexample | |
18506 | ||
18507 | Kill the inferior running program. | |
18508 | ||
18509 | @subsubheading @value{GDBN} Command | |
18510 | ||
18511 | The corresponding @value{GDBN} command is @samp{kill}. | |
18512 | ||
18513 | @subsubheading Example | |
18514 | N.A. | |
18515 | ||
18516 | ||
18517 | @subheading The @code{-exec-arguments} Command | |
18518 | @findex -exec-arguments | |
18519 | ||
18520 | @subsubheading Synopsis | |
18521 | ||
18522 | @smallexample | |
18523 | -exec-arguments @var{args} | |
18524 | @end smallexample | |
18525 | ||
18526 | Set the inferior program arguments, to be used in the next | |
18527 | @samp{-exec-run}. | |
18528 | ||
18529 | @subsubheading @value{GDBN} Command | |
18530 | ||
18531 | The corresponding @value{GDBN} command is @samp{set args}. | |
18532 | ||
18533 | @subsubheading Example | |
18534 | ||
18535 | @c FIXME! | |
18536 | Don't have one around. | |
18537 | ||
18538 | ||
18539 | @subheading The @code{-exec-continue} Command | |
18540 | @findex -exec-continue | |
18541 | ||
18542 | @subsubheading Synopsis | |
18543 | ||
18544 | @smallexample | |
18545 | -exec-continue | |
18546 | @end smallexample | |
18547 | ||
18548 | Asynchronous command. Resumes the execution of the inferior program | |
18549 | until a breakpoint is encountered, or until the inferior exits. | |
18550 | ||
18551 | @subsubheading @value{GDBN} Command | |
18552 | ||
18553 | The corresponding @value{GDBN} corresponding is @samp{continue}. | |
18554 | ||
18555 | @subsubheading Example | |
18556 | ||
18557 | @smallexample | |
18558 | -exec-continue | |
18559 | ^running | |
18560 | (@value{GDBP}) | |
18561 | @@Hello world | |
18562 | *stopped,reason="breakpoint-hit",bkptno="2",frame=@{func="foo",args=[], | |
76ff342d | 18563 | file="hello.c",fullname="/home/foo/bar/devo/myproject/hello.c",line="13"@} |
922fbb7b AC |
18564 | (@value{GDBP}) |
18565 | @end smallexample | |
18566 | ||
18567 | ||
18568 | @subheading The @code{-exec-finish} Command | |
18569 | @findex -exec-finish | |
18570 | ||
18571 | @subsubheading Synopsis | |
18572 | ||
18573 | @smallexample | |
18574 | -exec-finish | |
18575 | @end smallexample | |
18576 | ||
18577 | Asynchronous command. Resumes the execution of the inferior program | |
18578 | until the current function is exited. Displays the results returned by | |
18579 | the function. | |
18580 | ||
18581 | @subsubheading @value{GDBN} Command | |
18582 | ||
18583 | The corresponding @value{GDBN} command is @samp{finish}. | |
18584 | ||
18585 | @subsubheading Example | |
18586 | ||
18587 | Function returning @code{void}. | |
18588 | ||
18589 | @smallexample | |
18590 | -exec-finish | |
18591 | ^running | |
18592 | (@value{GDBP}) | |
18593 | @@hello from foo | |
18594 | *stopped,reason="function-finished",frame=@{func="main",args=[], | |
76ff342d | 18595 | file="hello.c",fullname="/home/foo/bar/devo/myproject/hello.c",line="7"@} |
922fbb7b AC |
18596 | (@value{GDBP}) |
18597 | @end smallexample | |
18598 | ||
18599 | Function returning other than @code{void}. The name of the internal | |
18600 | @value{GDBN} variable storing the result is printed, together with the | |
18601 | value itself. | |
18602 | ||
18603 | @smallexample | |
18604 | -exec-finish | |
18605 | ^running | |
18606 | (@value{GDBP}) | |
18607 | *stopped,reason="function-finished",frame=@{addr="0x000107b0",func="foo", | |
18608 | args=[@{name="a",value="1"],@{name="b",value="9"@}@}, | |
76ff342d | 18609 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b AC |
18610 | gdb-result-var="$1",return-value="0" |
18611 | (@value{GDBP}) | |
18612 | @end smallexample | |
18613 | ||
18614 | ||
18615 | @subheading The @code{-exec-interrupt} Command | |
18616 | @findex -exec-interrupt | |
18617 | ||
18618 | @subsubheading Synopsis | |
18619 | ||
18620 | @smallexample | |
18621 | -exec-interrupt | |
18622 | @end smallexample | |
18623 | ||
18624 | Asynchronous command. Interrupts the background execution of the target. | |
18625 | Note how the token associated with the stop message is the one for the | |
18626 | execution command that has been interrupted. The token for the interrupt | |
18627 | itself only appears in the @samp{^done} output. If the user is trying to | |
18628 | interrupt a non-running program, an error message will be printed. | |
18629 | ||
18630 | @subsubheading @value{GDBN} Command | |
18631 | ||
18632 | The corresponding @value{GDBN} command is @samp{interrupt}. | |
18633 | ||
18634 | @subsubheading Example | |
18635 | ||
18636 | @smallexample | |
18637 | (@value{GDBP}) | |
18638 | 111-exec-continue | |
18639 | 111^running | |
18640 | ||
18641 | (@value{GDBP}) | |
18642 | 222-exec-interrupt | |
18643 | 222^done | |
18644 | (@value{GDBP}) | |
18645 | 111*stopped,signal-name="SIGINT",signal-meaning="Interrupt", | |
76ff342d DJ |
18646 | frame=@{addr="0x00010140",func="foo",args=[],file="try.c", |
18647 | fullname="/home/foo/bar/devo/myproject/try.c",line="13"@} | |
922fbb7b AC |
18648 | (@value{GDBP}) |
18649 | ||
18650 | (@value{GDBP}) | |
18651 | -exec-interrupt | |
18652 | ^error,msg="mi_cmd_exec_interrupt: Inferior not executing." | |
18653 | (@value{GDBP}) | |
18654 | @end smallexample | |
18655 | ||
18656 | ||
18657 | @subheading The @code{-exec-next} Command | |
18658 | @findex -exec-next | |
18659 | ||
18660 | @subsubheading Synopsis | |
18661 | ||
18662 | @smallexample | |
18663 | -exec-next | |
18664 | @end smallexample | |
18665 | ||
18666 | Asynchronous command. Resumes execution of the inferior program, stopping | |
18667 | when the beginning of the next source line is reached. | |
18668 | ||
18669 | @subsubheading @value{GDBN} Command | |
18670 | ||
18671 | The corresponding @value{GDBN} command is @samp{next}. | |
18672 | ||
18673 | @subsubheading Example | |
18674 | ||
18675 | @smallexample | |
18676 | -exec-next | |
18677 | ^running | |
18678 | (@value{GDBP}) | |
18679 | *stopped,reason="end-stepping-range",line="8",file="hello.c" | |
18680 | (@value{GDBP}) | |
18681 | @end smallexample | |
18682 | ||
18683 | ||
18684 | @subheading The @code{-exec-next-instruction} Command | |
18685 | @findex -exec-next-instruction | |
18686 | ||
18687 | @subsubheading Synopsis | |
18688 | ||
18689 | @smallexample | |
18690 | -exec-next-instruction | |
18691 | @end smallexample | |
18692 | ||
18693 | Asynchronous command. Executes one machine instruction. If the | |
18694 | instruction is a function call continues until the function returns. If | |
18695 | the program stops at an instruction in the middle of a source line, the | |
18696 | address will be printed as well. | |
18697 | ||
18698 | @subsubheading @value{GDBN} Command | |
18699 | ||
18700 | The corresponding @value{GDBN} command is @samp{nexti}. | |
18701 | ||
18702 | @subsubheading Example | |
18703 | ||
18704 | @smallexample | |
18705 | (@value{GDBP}) | |
18706 | -exec-next-instruction | |
18707 | ^running | |
18708 | ||
18709 | (@value{GDBP}) | |
18710 | *stopped,reason="end-stepping-range", | |
18711 | addr="0x000100d4",line="5",file="hello.c" | |
18712 | (@value{GDBP}) | |
18713 | @end smallexample | |
18714 | ||
18715 | ||
18716 | @subheading The @code{-exec-return} Command | |
18717 | @findex -exec-return | |
18718 | ||
18719 | @subsubheading Synopsis | |
18720 | ||
18721 | @smallexample | |
18722 | -exec-return | |
18723 | @end smallexample | |
18724 | ||
18725 | Makes current function return immediately. Doesn't execute the inferior. | |
18726 | Displays the new current frame. | |
18727 | ||
18728 | @subsubheading @value{GDBN} Command | |
18729 | ||
18730 | The corresponding @value{GDBN} command is @samp{return}. | |
18731 | ||
18732 | @subsubheading Example | |
18733 | ||
18734 | @smallexample | |
18735 | (@value{GDBP}) | |
18736 | 200-break-insert callee4 | |
18737 | 200^done,bkpt=@{number="1",addr="0x00010734", | |
18738 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
18739 | (@value{GDBP}) | |
18740 | 000-exec-run | |
18741 | 000^running | |
18742 | (@value{GDBP}) | |
18743 | 000*stopped,reason="breakpoint-hit",bkptno="1", | |
18744 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
18745 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
18746 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
922fbb7b AC |
18747 | (@value{GDBP}) |
18748 | 205-break-delete | |
18749 | 205^done | |
18750 | (@value{GDBP}) | |
18751 | 111-exec-return | |
18752 | 111^done,frame=@{level="0",func="callee3", | |
18753 | args=[@{name="strarg", | |
18754 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
18755 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
18756 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
922fbb7b AC |
18757 | (@value{GDBP}) |
18758 | @end smallexample | |
18759 | ||
18760 | ||
18761 | @subheading The @code{-exec-run} Command | |
18762 | @findex -exec-run | |
18763 | ||
18764 | @subsubheading Synopsis | |
18765 | ||
18766 | @smallexample | |
18767 | -exec-run | |
18768 | @end smallexample | |
18769 | ||
18770 | Asynchronous command. Starts execution of the inferior from the | |
18771 | beginning. The inferior executes until either a breakpoint is | |
18772 | encountered or the program exits. | |
18773 | ||
18774 | @subsubheading @value{GDBN} Command | |
18775 | ||
18776 | The corresponding @value{GDBN} command is @samp{run}. | |
18777 | ||
18778 | @subsubheading Example | |
18779 | ||
18780 | @smallexample | |
18781 | (@value{GDBP}) | |
18782 | -break-insert main | |
18783 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@} | |
18784 | (@value{GDBP}) | |
18785 | -exec-run | |
18786 | ^running | |
18787 | (@value{GDBP}) | |
18788 | *stopped,reason="breakpoint-hit",bkptno="1", | |
76ff342d DJ |
18789 | frame=@{func="main",args=[],file="recursive2.c", |
18790 | fullname="/home/foo/bar/devo/myproject/recursive2.c",line="4"@} | |
922fbb7b AC |
18791 | (@value{GDBP}) |
18792 | @end smallexample | |
18793 | ||
18794 | ||
18795 | @subheading The @code{-exec-show-arguments} Command | |
18796 | @findex -exec-show-arguments | |
18797 | ||
18798 | @subsubheading Synopsis | |
18799 | ||
18800 | @smallexample | |
18801 | -exec-show-arguments | |
18802 | @end smallexample | |
18803 | ||
18804 | Print the arguments of the program. | |
18805 | ||
18806 | @subsubheading @value{GDBN} Command | |
18807 | ||
18808 | The corresponding @value{GDBN} command is @samp{show args}. | |
18809 | ||
18810 | @subsubheading Example | |
18811 | N.A. | |
18812 | ||
18813 | @c @subheading -exec-signal | |
18814 | ||
18815 | @subheading The @code{-exec-step} Command | |
18816 | @findex -exec-step | |
18817 | ||
18818 | @subsubheading Synopsis | |
18819 | ||
18820 | @smallexample | |
18821 | -exec-step | |
18822 | @end smallexample | |
18823 | ||
18824 | Asynchronous command. Resumes execution of the inferior program, stopping | |
18825 | when the beginning of the next source line is reached, if the next | |
18826 | source line is not a function call. If it is, stop at the first | |
18827 | instruction of the called function. | |
18828 | ||
18829 | @subsubheading @value{GDBN} Command | |
18830 | ||
18831 | The corresponding @value{GDBN} command is @samp{step}. | |
18832 | ||
18833 | @subsubheading Example | |
18834 | ||
18835 | Stepping into a function: | |
18836 | ||
18837 | @smallexample | |
18838 | -exec-step | |
18839 | ^running | |
18840 | (@value{GDBP}) | |
18841 | *stopped,reason="end-stepping-range", | |
18842 | frame=@{func="foo",args=[@{name="a",value="10"@}, | |
76ff342d DJ |
18843 | @{name="b",value="0"@}],file="recursive2.c", |
18844 | fullname="/home/foo/bar/devo/myproject/recursive2.c",line="11"@} | |
922fbb7b AC |
18845 | (@value{GDBP}) |
18846 | @end smallexample | |
18847 | ||
18848 | Regular stepping: | |
18849 | ||
18850 | @smallexample | |
18851 | -exec-step | |
18852 | ^running | |
18853 | (@value{GDBP}) | |
18854 | *stopped,reason="end-stepping-range",line="14",file="recursive2.c" | |
18855 | (@value{GDBP}) | |
18856 | @end smallexample | |
18857 | ||
18858 | ||
18859 | @subheading The @code{-exec-step-instruction} Command | |
18860 | @findex -exec-step-instruction | |
18861 | ||
18862 | @subsubheading Synopsis | |
18863 | ||
18864 | @smallexample | |
18865 | -exec-step-instruction | |
18866 | @end smallexample | |
18867 | ||
18868 | Asynchronous command. Resumes the inferior which executes one machine | |
18869 | instruction. The output, once @value{GDBN} has stopped, will vary depending on | |
18870 | whether we have stopped in the middle of a source line or not. In the | |
18871 | former case, the address at which the program stopped will be printed as | |
18872 | well. | |
18873 | ||
18874 | @subsubheading @value{GDBN} Command | |
18875 | ||
18876 | The corresponding @value{GDBN} command is @samp{stepi}. | |
18877 | ||
18878 | @subsubheading Example | |
18879 | ||
18880 | @smallexample | |
18881 | (@value{GDBP}) | |
18882 | -exec-step-instruction | |
18883 | ^running | |
18884 | ||
18885 | (@value{GDBP}) | |
18886 | *stopped,reason="end-stepping-range", | |
76ff342d DJ |
18887 | frame=@{func="foo",args=[],file="try.c", |
18888 | fullname="/home/foo/bar/devo/myproject/try.c",line="10"@} | |
922fbb7b AC |
18889 | (@value{GDBP}) |
18890 | -exec-step-instruction | |
18891 | ^running | |
18892 | ||
18893 | (@value{GDBP}) | |
18894 | *stopped,reason="end-stepping-range", | |
76ff342d DJ |
18895 | frame=@{addr="0x000100f4",func="foo",args=[],file="try.c", |
18896 | fullname="/home/foo/bar/devo/myproject/try.c",line="10"@} | |
922fbb7b AC |
18897 | (@value{GDBP}) |
18898 | @end smallexample | |
18899 | ||
18900 | ||
18901 | @subheading The @code{-exec-until} Command | |
18902 | @findex -exec-until | |
18903 | ||
18904 | @subsubheading Synopsis | |
18905 | ||
18906 | @smallexample | |
18907 | -exec-until [ @var{location} ] | |
18908 | @end smallexample | |
18909 | ||
18910 | Asynchronous command. Executes the inferior until the @var{location} | |
18911 | specified in the argument is reached. If there is no argument, the inferior | |
18912 | executes until a source line greater than the current one is reached. | |
18913 | The reason for stopping in this case will be @samp{location-reached}. | |
18914 | ||
18915 | @subsubheading @value{GDBN} Command | |
18916 | ||
18917 | The corresponding @value{GDBN} command is @samp{until}. | |
18918 | ||
18919 | @subsubheading Example | |
18920 | ||
18921 | @smallexample | |
18922 | (@value{GDBP}) | |
18923 | -exec-until recursive2.c:6 | |
18924 | ^running | |
18925 | (@value{GDBP}) | |
18926 | x = 55 | |
18927 | *stopped,reason="location-reached",frame=@{func="main",args=[], | |
76ff342d | 18928 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="6"@} |
922fbb7b AC |
18929 | (@value{GDBP}) |
18930 | @end smallexample | |
18931 | ||
18932 | @ignore | |
18933 | @subheading -file-clear | |
18934 | Is this going away???? | |
18935 | @end ignore | |
18936 | ||
18937 | ||
18938 | @subheading The @code{-file-exec-and-symbols} Command | |
18939 | @findex -file-exec-and-symbols | |
18940 | ||
18941 | @subsubheading Synopsis | |
18942 | ||
18943 | @smallexample | |
18944 | -file-exec-and-symbols @var{file} | |
18945 | @end smallexample | |
18946 | ||
18947 | Specify the executable file to be debugged. This file is the one from | |
18948 | which the symbol table is also read. If no file is specified, the | |
18949 | command clears the executable and symbol information. If breakpoints | |
18950 | are set when using this command with no arguments, @value{GDBN} will produce | |
18951 | error messages. Otherwise, no output is produced, except a completion | |
18952 | notification. | |
18953 | ||
18954 | @subsubheading @value{GDBN} Command | |
18955 | ||
18956 | The corresponding @value{GDBN} command is @samp{file}. | |
18957 | ||
18958 | @subsubheading Example | |
18959 | ||
18960 | @smallexample | |
18961 | (@value{GDBP}) | |
18962 | -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx | |
18963 | ^done | |
18964 | (@value{GDBP}) | |
18965 | @end smallexample | |
18966 | ||
18967 | ||
18968 | @subheading The @code{-file-exec-file} Command | |
18969 | @findex -file-exec-file | |
18970 | ||
18971 | @subsubheading Synopsis | |
18972 | ||
18973 | @smallexample | |
18974 | -file-exec-file @var{file} | |
18975 | @end smallexample | |
18976 | ||
18977 | Specify the executable file to be debugged. Unlike | |
18978 | @samp{-file-exec-and-symbols}, the symbol table is @emph{not} read | |
18979 | from this file. If used without argument, @value{GDBN} clears the information | |
18980 | about the executable file. No output is produced, except a completion | |
18981 | notification. | |
18982 | ||
18983 | @subsubheading @value{GDBN} Command | |
18984 | ||
18985 | The corresponding @value{GDBN} command is @samp{exec-file}. | |
18986 | ||
18987 | @subsubheading Example | |
18988 | ||
18989 | @smallexample | |
18990 | (@value{GDBP}) | |
18991 | -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx | |
18992 | ^done | |
18993 | (@value{GDBP}) | |
18994 | @end smallexample | |
18995 | ||
18996 | ||
18997 | @subheading The @code{-file-list-exec-sections} Command | |
18998 | @findex -file-list-exec-sections | |
18999 | ||
19000 | @subsubheading Synopsis | |
19001 | ||
19002 | @smallexample | |
19003 | -file-list-exec-sections | |
19004 | @end smallexample | |
19005 | ||
19006 | List the sections of the current executable file. | |
19007 | ||
19008 | @subsubheading @value{GDBN} Command | |
19009 | ||
19010 | The @value{GDBN} command @samp{info file} shows, among the rest, the same | |
19011 | information as this command. @code{gdbtk} has a corresponding command | |
19012 | @samp{gdb_load_info}. | |
19013 | ||
19014 | @subsubheading Example | |
19015 | N.A. | |
19016 | ||
19017 | ||
1abaf70c BR |
19018 | @subheading The @code{-file-list-exec-source-file} Command |
19019 | @findex -file-list-exec-source-file | |
19020 | ||
19021 | @subsubheading Synopsis | |
19022 | ||
19023 | @smallexample | |
19024 | -file-list-exec-source-file | |
19025 | @end smallexample | |
19026 | ||
b383017d | 19027 | List the line number, the current source file, and the absolute path |
1abaf70c BR |
19028 | to the current source file for the current executable. |
19029 | ||
19030 | @subsubheading @value{GDBN} Command | |
19031 | ||
19032 | There's no @value{GDBN} command which directly corresponds to this one. | |
19033 | ||
19034 | @subsubheading Example | |
19035 | ||
19036 | @smallexample | |
19037 | (@value{GDBP}) | |
19038 | 123-file-list-exec-source-file | |
19039 | 123^done,line="1",file="foo.c",fullname="/home/bar/foo.c" | |
19040 | (@value{GDBP}) | |
19041 | @end smallexample | |
19042 | ||
19043 | ||
922fbb7b AC |
19044 | @subheading The @code{-file-list-exec-source-files} Command |
19045 | @findex -file-list-exec-source-files | |
19046 | ||
19047 | @subsubheading Synopsis | |
19048 | ||
19049 | @smallexample | |
19050 | -file-list-exec-source-files | |
19051 | @end smallexample | |
19052 | ||
19053 | List the source files for the current executable. | |
19054 | ||
57c22c6c BR |
19055 | It will always output the filename, but only when GDB can find the absolute |
19056 | file name of a source file, will it output the fullname. | |
19057 | ||
922fbb7b AC |
19058 | @subsubheading @value{GDBN} Command |
19059 | ||
19060 | There's no @value{GDBN} command which directly corresponds to this one. | |
19061 | @code{gdbtk} has an analogous command @samp{gdb_listfiles}. | |
19062 | ||
19063 | @subsubheading Example | |
57c22c6c BR |
19064 | @smallexample |
19065 | (@value{GDBP}) | |
19066 | -file-list-exec-source-files | |
19067 | ^done,files=[ | |
19068 | @{file=foo.c,fullname=/home/foo.c@}, | |
19069 | @{file=/home/bar.c,fullname=/home/bar.c@}, | |
19070 | @{file=gdb_could_not_find_fullpath.c@}] | |
19071 | (@value{GDBP}) | |
19072 | @end smallexample | |
922fbb7b AC |
19073 | |
19074 | @subheading The @code{-file-list-shared-libraries} Command | |
19075 | @findex -file-list-shared-libraries | |
19076 | ||
19077 | @subsubheading Synopsis | |
19078 | ||
19079 | @smallexample | |
19080 | -file-list-shared-libraries | |
19081 | @end smallexample | |
19082 | ||
19083 | List the shared libraries in the program. | |
19084 | ||
19085 | @subsubheading @value{GDBN} Command | |
19086 | ||
19087 | The corresponding @value{GDBN} command is @samp{info shared}. | |
19088 | ||
19089 | @subsubheading Example | |
19090 | N.A. | |
19091 | ||
19092 | ||
19093 | @subheading The @code{-file-list-symbol-files} Command | |
19094 | @findex -file-list-symbol-files | |
19095 | ||
19096 | @subsubheading Synopsis | |
19097 | ||
19098 | @smallexample | |
19099 | -file-list-symbol-files | |
19100 | @end smallexample | |
19101 | ||
19102 | List symbol files. | |
19103 | ||
19104 | @subsubheading @value{GDBN} Command | |
19105 | ||
19106 | The corresponding @value{GDBN} command is @samp{info file} (part of it). | |
19107 | ||
19108 | @subsubheading Example | |
19109 | N.A. | |
19110 | ||
19111 | ||
19112 | @subheading The @code{-file-symbol-file} Command | |
19113 | @findex -file-symbol-file | |
19114 | ||
19115 | @subsubheading Synopsis | |
19116 | ||
19117 | @smallexample | |
19118 | -file-symbol-file @var{file} | |
19119 | @end smallexample | |
19120 | ||
19121 | Read symbol table info from the specified @var{file} argument. When | |
19122 | used without arguments, clears @value{GDBN}'s symbol table info. No output is | |
19123 | produced, except for a completion notification. | |
19124 | ||
19125 | @subsubheading @value{GDBN} Command | |
19126 | ||
19127 | The corresponding @value{GDBN} command is @samp{symbol-file}. | |
19128 | ||
19129 | @subsubheading Example | |
19130 | ||
19131 | @smallexample | |
19132 | (@value{GDBP}) | |
19133 | -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx | |
19134 | ^done | |
19135 | (@value{GDBP}) | |
19136 | @end smallexample | |
19137 | ||
19138 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
19139 | @node GDB/MI Miscellaneous Commands | |
19140 | @section Miscellaneous @value{GDBN} commands in @sc{gdb/mi} | |
19141 | ||
19142 | @c @subheading -gdb-complete | |
19143 | ||
19144 | @subheading The @code{-gdb-exit} Command | |
19145 | @findex -gdb-exit | |
19146 | ||
19147 | @subsubheading Synopsis | |
19148 | ||
19149 | @smallexample | |
19150 | -gdb-exit | |
19151 | @end smallexample | |
19152 | ||
19153 | Exit @value{GDBN} immediately. | |
19154 | ||
19155 | @subsubheading @value{GDBN} Command | |
19156 | ||
19157 | Approximately corresponds to @samp{quit}. | |
19158 | ||
19159 | @subsubheading Example | |
19160 | ||
19161 | @smallexample | |
19162 | (@value{GDBP}) | |
19163 | -gdb-exit | |
19164 | @end smallexample | |
19165 | ||
19166 | @subheading The @code{-gdb-set} Command | |
19167 | @findex -gdb-set | |
19168 | ||
19169 | @subsubheading Synopsis | |
19170 | ||
19171 | @smallexample | |
19172 | -gdb-set | |
19173 | @end smallexample | |
19174 | ||
19175 | Set an internal @value{GDBN} variable. | |
19176 | @c IS THIS A DOLLAR VARIABLE? OR SOMETHING LIKE ANNOTATE ????? | |
19177 | ||
19178 | @subsubheading @value{GDBN} Command | |
19179 | ||
19180 | The corresponding @value{GDBN} command is @samp{set}. | |
19181 | ||
19182 | @subsubheading Example | |
19183 | ||
19184 | @smallexample | |
19185 | (@value{GDBP}) | |
19186 | -gdb-set $foo=3 | |
19187 | ^done | |
19188 | (@value{GDBP}) | |
19189 | @end smallexample | |
19190 | ||
19191 | ||
19192 | @subheading The @code{-gdb-show} Command | |
19193 | @findex -gdb-show | |
19194 | ||
19195 | @subsubheading Synopsis | |
19196 | ||
19197 | @smallexample | |
19198 | -gdb-show | |
19199 | @end smallexample | |
19200 | ||
19201 | Show the current value of a @value{GDBN} variable. | |
19202 | ||
19203 | @subsubheading @value{GDBN} command | |
19204 | ||
19205 | The corresponding @value{GDBN} command is @samp{show}. | |
19206 | ||
19207 | @subsubheading Example | |
19208 | ||
19209 | @smallexample | |
19210 | (@value{GDBP}) | |
19211 | -gdb-show annotate | |
19212 | ^done,value="0" | |
19213 | (@value{GDBP}) | |
19214 | @end smallexample | |
19215 | ||
19216 | @c @subheading -gdb-source | |
19217 | ||
19218 | ||
19219 | @subheading The @code{-gdb-version} Command | |
19220 | @findex -gdb-version | |
19221 | ||
19222 | @subsubheading Synopsis | |
19223 | ||
19224 | @smallexample | |
19225 | -gdb-version | |
19226 | @end smallexample | |
19227 | ||
19228 | Show version information for @value{GDBN}. Used mostly in testing. | |
19229 | ||
19230 | @subsubheading @value{GDBN} Command | |
19231 | ||
19232 | There's no equivalent @value{GDBN} command. @value{GDBN} by default shows this | |
19233 | information when you start an interactive session. | |
19234 | ||
19235 | @subsubheading Example | |
19236 | ||
19237 | @c This example modifies the actual output from GDB to avoid overfull | |
19238 | @c box in TeX. | |
19239 | @smallexample | |
19240 | (@value{GDBP}) | |
19241 | -gdb-version | |
19242 | ~GNU gdb 5.2.1 | |
19243 | ~Copyright 2000 Free Software Foundation, Inc. | |
19244 | ~GDB is free software, covered by the GNU General Public License, and | |
19245 | ~you are welcome to change it and/or distribute copies of it under | |
19246 | ~ certain conditions. | |
19247 | ~Type "show copying" to see the conditions. | |
19248 | ~There is absolutely no warranty for GDB. Type "show warranty" for | |
19249 | ~ details. | |
b383017d | 19250 | ~This GDB was configured as |
922fbb7b AC |
19251 | "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi". |
19252 | ^done | |
19253 | (@value{GDBP}) | |
19254 | @end smallexample | |
19255 | ||
19256 | @subheading The @code{-interpreter-exec} Command | |
19257 | @findex -interpreter-exec | |
19258 | ||
19259 | @subheading Synopsis | |
19260 | ||
19261 | @smallexample | |
19262 | -interpreter-exec @var{interpreter} @var{command} | |
19263 | @end smallexample | |
19264 | ||
19265 | Execute the specified @var{command} in the given @var{interpreter}. | |
19266 | ||
19267 | @subheading @value{GDBN} Command | |
19268 | ||
19269 | The corresponding @value{GDBN} command is @samp{interpreter-exec}. | |
19270 | ||
19271 | @subheading Example | |
19272 | ||
19273 | @smallexample | |
19274 | (@value{GDBP}) | |
19275 | -interpreter-exec console "break main" | |
19276 | &"During symbol reading, couldn't parse type; debugger out of date?.\n" | |
19277 | &"During symbol reading, bad structure-type format.\n" | |
19278 | ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n" | |
19279 | ^done | |
19280 | (@value{GDBP}) | |
19281 | @end smallexample | |
19282 | ||
3cb3b8df BR |
19283 | @subheading The @code{-inferior-tty-set} Command |
19284 | @findex -inferior-tty-set | |
19285 | ||
19286 | @subheading Synopsis | |
19287 | ||
19288 | @smallexample | |
19289 | -inferior-tty-set /dev/pts/1 | |
19290 | @end smallexample | |
19291 | ||
19292 | Set terminal for future runs of the program being debugged. | |
19293 | ||
19294 | @subheading @value{GDBN} Command | |
19295 | ||
19296 | The corresponding @value{GDBN} command is @samp{set inferior-tty /dev/pts/1}. | |
19297 | ||
19298 | @subheading Example | |
19299 | ||
19300 | @smallexample | |
19301 | (@value{GDBP}) | |
19302 | -inferior-tty-set /dev/pts/1 | |
19303 | ^done | |
19304 | (@value{GDBP}) | |
19305 | @end smallexample | |
19306 | ||
19307 | @subheading The @code{-inferior-tty-show} Command | |
19308 | @findex -inferior-tty-show | |
19309 | ||
19310 | @subheading Synopsis | |
19311 | ||
19312 | @smallexample | |
19313 | -inferior-tty-show | |
19314 | @end smallexample | |
19315 | ||
19316 | Show terminal for future runs of program being debugged. | |
19317 | ||
19318 | @subheading @value{GDBN} Command | |
19319 | ||
38f1196a | 19320 | The corresponding @value{GDBN} command is @samp{show inferior-tty}. |
3cb3b8df BR |
19321 | |
19322 | @subheading Example | |
19323 | ||
19324 | @smallexample | |
19325 | (@value{GDBP}) | |
19326 | -inferior-tty-set /dev/pts/1 | |
19327 | ^done | |
19328 | (@value{GDBP}) | |
19329 | -inferior-tty-show | |
19330 | ^done,inferior_tty_terminal="/dev/pts/1" | |
19331 | (@value{GDBP}) | |
19332 | @end smallexample | |
19333 | ||
922fbb7b AC |
19334 | @ignore |
19335 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
19336 | @node GDB/MI Kod Commands | |
19337 | @section @sc{gdb/mi} Kod Commands | |
19338 | ||
19339 | The Kod commands are not implemented. | |
19340 | ||
19341 | @c @subheading -kod-info | |
19342 | ||
19343 | @c @subheading -kod-list | |
19344 | ||
19345 | @c @subheading -kod-list-object-types | |
19346 | ||
19347 | @c @subheading -kod-show | |
19348 | ||
19349 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
19350 | @node GDB/MI Memory Overlay Commands | |
19351 | @section @sc{gdb/mi} Memory Overlay Commands | |
19352 | ||
19353 | The memory overlay commands are not implemented. | |
19354 | ||
19355 | @c @subheading -overlay-auto | |
19356 | ||
19357 | @c @subheading -overlay-list-mapping-state | |
19358 | ||
19359 | @c @subheading -overlay-list-overlays | |
19360 | ||
19361 | @c @subheading -overlay-map | |
19362 | ||
19363 | @c @subheading -overlay-off | |
19364 | ||
19365 | @c @subheading -overlay-on | |
19366 | ||
19367 | @c @subheading -overlay-unmap | |
19368 | ||
19369 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
19370 | @node GDB/MI Signal Handling Commands | |
19371 | @section @sc{gdb/mi} Signal Handling Commands | |
19372 | ||
19373 | Signal handling commands are not implemented. | |
19374 | ||
19375 | @c @subheading -signal-handle | |
19376 | ||
19377 | @c @subheading -signal-list-handle-actions | |
19378 | ||
19379 | @c @subheading -signal-list-signal-types | |
19380 | @end ignore | |
19381 | ||
19382 | ||
19383 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
19384 | @node GDB/MI Stack Manipulation | |
19385 | @section @sc{gdb/mi} Stack Manipulation Commands | |
19386 | ||
dcaaae04 NR |
19387 | |
19388 | @subheading The @code{-stack-info-frame} Command | |
19389 | @findex -stack-info-frame | |
19390 | ||
19391 | @subsubheading Synopsis | |
19392 | ||
19393 | @smallexample | |
19394 | -stack-info-frame | |
19395 | @end smallexample | |
19396 | ||
19397 | Get info on the selected frame. | |
19398 | ||
19399 | @subsubheading @value{GDBN} Command | |
19400 | ||
19401 | The corresponding @value{GDBN} command is @samp{info frame} or @samp{frame} | |
19402 | (without arguments). | |
19403 | ||
19404 | @subsubheading Example | |
19405 | ||
19406 | @smallexample | |
19407 | (@value{GDBP}) | |
19408 | -stack-info-frame | |
19409 | ^done,frame=@{level="1",addr="0x0001076c",func="callee3", | |
19410 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
19411 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@} | |
19412 | (@value{GDBP}) | |
19413 | @end smallexample | |
19414 | ||
922fbb7b AC |
19415 | @subheading The @code{-stack-info-depth} Command |
19416 | @findex -stack-info-depth | |
19417 | ||
19418 | @subsubheading Synopsis | |
19419 | ||
19420 | @smallexample | |
19421 | -stack-info-depth [ @var{max-depth} ] | |
19422 | @end smallexample | |
19423 | ||
19424 | Return the depth of the stack. If the integer argument @var{max-depth} | |
19425 | is specified, do not count beyond @var{max-depth} frames. | |
19426 | ||
19427 | @subsubheading @value{GDBN} Command | |
19428 | ||
19429 | There's no equivalent @value{GDBN} command. | |
19430 | ||
19431 | @subsubheading Example | |
19432 | ||
19433 | For a stack with frame levels 0 through 11: | |
19434 | ||
19435 | @smallexample | |
19436 | (@value{GDBP}) | |
19437 | -stack-info-depth | |
19438 | ^done,depth="12" | |
19439 | (@value{GDBP}) | |
19440 | -stack-info-depth 4 | |
19441 | ^done,depth="4" | |
19442 | (@value{GDBP}) | |
19443 | -stack-info-depth 12 | |
19444 | ^done,depth="12" | |
19445 | (@value{GDBP}) | |
19446 | -stack-info-depth 11 | |
19447 | ^done,depth="11" | |
19448 | (@value{GDBP}) | |
19449 | -stack-info-depth 13 | |
19450 | ^done,depth="12" | |
19451 | (@value{GDBP}) | |
19452 | @end smallexample | |
19453 | ||
19454 | @subheading The @code{-stack-list-arguments} Command | |
19455 | @findex -stack-list-arguments | |
19456 | ||
19457 | @subsubheading Synopsis | |
19458 | ||
19459 | @smallexample | |
19460 | -stack-list-arguments @var{show-values} | |
19461 | [ @var{low-frame} @var{high-frame} ] | |
19462 | @end smallexample | |
19463 | ||
19464 | Display a list of the arguments for the frames between @var{low-frame} | |
19465 | and @var{high-frame} (inclusive). If @var{low-frame} and | |
19466 | @var{high-frame} are not provided, list the arguments for the whole call | |
19467 | stack. | |
19468 | ||
19469 | The @var{show-values} argument must have a value of 0 or 1. A value of | |
19470 | 0 means that only the names of the arguments are listed, a value of 1 | |
19471 | means that both names and values of the arguments are printed. | |
19472 | ||
19473 | @subsubheading @value{GDBN} Command | |
19474 | ||
19475 | @value{GDBN} does not have an equivalent command. @code{gdbtk} has a | |
19476 | @samp{gdb_get_args} command which partially overlaps with the | |
19477 | functionality of @samp{-stack-list-arguments}. | |
19478 | ||
19479 | @subsubheading Example | |
19480 | ||
19481 | @smallexample | |
19482 | (@value{GDBP}) | |
19483 | -stack-list-frames | |
19484 | ^done, | |
19485 | stack=[ | |
19486 | frame=@{level="0",addr="0x00010734",func="callee4", | |
76ff342d DJ |
19487 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
19488 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@}, | |
922fbb7b | 19489 | frame=@{level="1",addr="0x0001076c",func="callee3", |
76ff342d DJ |
19490 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
19491 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@}, | |
922fbb7b | 19492 | frame=@{level="2",addr="0x0001078c",func="callee2", |
76ff342d DJ |
19493 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
19494 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22"@}, | |
922fbb7b | 19495 | frame=@{level="3",addr="0x000107b4",func="callee1", |
76ff342d DJ |
19496 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
19497 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27"@}, | |
922fbb7b | 19498 | frame=@{level="4",addr="0x000107e0",func="main", |
76ff342d DJ |
19499 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
19500 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32"@}] | |
922fbb7b AC |
19501 | (@value{GDBP}) |
19502 | -stack-list-arguments 0 | |
19503 | ^done, | |
19504 | stack-args=[ | |
19505 | frame=@{level="0",args=[]@}, | |
19506 | frame=@{level="1",args=[name="strarg"]@}, | |
19507 | frame=@{level="2",args=[name="intarg",name="strarg"]@}, | |
19508 | frame=@{level="3",args=[name="intarg",name="strarg",name="fltarg"]@}, | |
19509 | frame=@{level="4",args=[]@}] | |
19510 | (@value{GDBP}) | |
19511 | -stack-list-arguments 1 | |
19512 | ^done, | |
19513 | stack-args=[ | |
19514 | frame=@{level="0",args=[]@}, | |
19515 | frame=@{level="1", | |
19516 | args=[@{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
19517 | frame=@{level="2",args=[ | |
19518 | @{name="intarg",value="2"@}, | |
19519 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
19520 | @{frame=@{level="3",args=[ | |
19521 | @{name="intarg",value="2"@}, | |
19522 | @{name="strarg",value="0x11940 \"A string argument.\""@}, | |
19523 | @{name="fltarg",value="3.5"@}]@}, | |
19524 | frame=@{level="4",args=[]@}] | |
19525 | (@value{GDBP}) | |
19526 | -stack-list-arguments 0 2 2 | |
19527 | ^done,stack-args=[frame=@{level="2",args=[name="intarg",name="strarg"]@}] | |
19528 | (@value{GDBP}) | |
19529 | -stack-list-arguments 1 2 2 | |
19530 | ^done,stack-args=[frame=@{level="2", | |
19531 | args=[@{name="intarg",value="2"@}, | |
19532 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}] | |
19533 | (@value{GDBP}) | |
19534 | @end smallexample | |
19535 | ||
19536 | @c @subheading -stack-list-exception-handlers | |
19537 | ||
19538 | ||
19539 | @subheading The @code{-stack-list-frames} Command | |
19540 | @findex -stack-list-frames | |
19541 | ||
19542 | @subsubheading Synopsis | |
19543 | ||
19544 | @smallexample | |
19545 | -stack-list-frames [ @var{low-frame} @var{high-frame} ] | |
19546 | @end smallexample | |
19547 | ||
19548 | List the frames currently on the stack. For each frame it displays the | |
19549 | following info: | |
19550 | ||
19551 | @table @samp | |
19552 | @item @var{level} | |
19553 | The frame number, 0 being the topmost frame, i.e. the innermost function. | |
19554 | @item @var{addr} | |
19555 | The @code{$pc} value for that frame. | |
19556 | @item @var{func} | |
19557 | Function name. | |
19558 | @item @var{file} | |
19559 | File name of the source file where the function lives. | |
19560 | @item @var{line} | |
19561 | Line number corresponding to the @code{$pc}. | |
19562 | @end table | |
19563 | ||
19564 | If invoked without arguments, this command prints a backtrace for the | |
19565 | whole stack. If given two integer arguments, it shows the frames whose | |
19566 | levels are between the two arguments (inclusive). If the two arguments | |
19567 | are equal, it shows the single frame at the corresponding level. | |
19568 | ||
19569 | @subsubheading @value{GDBN} Command | |
19570 | ||
19571 | The corresponding @value{GDBN} commands are @samp{backtrace} and @samp{where}. | |
19572 | ||
19573 | @subsubheading Example | |
19574 | ||
19575 | Full stack backtrace: | |
19576 | ||
19577 | @smallexample | |
19578 | (@value{GDBP}) | |
19579 | -stack-list-frames | |
19580 | ^done,stack= | |
19581 | [frame=@{level="0",addr="0x0001076c",func="foo", | |
76ff342d | 19582 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="11"@}, |
922fbb7b | 19583 | frame=@{level="1",addr="0x000107a4",func="foo", |
76ff342d | 19584 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19585 | frame=@{level="2",addr="0x000107a4",func="foo", |
76ff342d | 19586 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19587 | frame=@{level="3",addr="0x000107a4",func="foo", |
76ff342d | 19588 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19589 | frame=@{level="4",addr="0x000107a4",func="foo", |
76ff342d | 19590 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19591 | frame=@{level="5",addr="0x000107a4",func="foo", |
76ff342d | 19592 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19593 | frame=@{level="6",addr="0x000107a4",func="foo", |
76ff342d | 19594 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19595 | frame=@{level="7",addr="0x000107a4",func="foo", |
76ff342d | 19596 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19597 | frame=@{level="8",addr="0x000107a4",func="foo", |
76ff342d | 19598 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19599 | frame=@{level="9",addr="0x000107a4",func="foo", |
76ff342d | 19600 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19601 | frame=@{level="10",addr="0x000107a4",func="foo", |
76ff342d | 19602 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19603 | frame=@{level="11",addr="0x00010738",func="main", |
76ff342d | 19604 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="4"@}] |
922fbb7b AC |
19605 | (@value{GDBP}) |
19606 | @end smallexample | |
19607 | ||
19608 | Show frames between @var{low_frame} and @var{high_frame}: | |
19609 | ||
19610 | @smallexample | |
19611 | (@value{GDBP}) | |
19612 | -stack-list-frames 3 5 | |
19613 | ^done,stack= | |
19614 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
76ff342d | 19615 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19616 | frame=@{level="4",addr="0x000107a4",func="foo", |
76ff342d | 19617 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}, |
922fbb7b | 19618 | frame=@{level="5",addr="0x000107a4",func="foo", |
76ff342d | 19619 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}] |
922fbb7b AC |
19620 | (@value{GDBP}) |
19621 | @end smallexample | |
19622 | ||
19623 | Show a single frame: | |
19624 | ||
19625 | @smallexample | |
19626 | (@value{GDBP}) | |
19627 | -stack-list-frames 3 3 | |
19628 | ^done,stack= | |
19629 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
76ff342d | 19630 | file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}] |
922fbb7b AC |
19631 | (@value{GDBP}) |
19632 | @end smallexample | |
19633 | ||
19634 | ||
19635 | @subheading The @code{-stack-list-locals} Command | |
19636 | @findex -stack-list-locals | |
19637 | ||
19638 | @subsubheading Synopsis | |
19639 | ||
19640 | @smallexample | |
19641 | -stack-list-locals @var{print-values} | |
19642 | @end smallexample | |
19643 | ||
265eeb58 NR |
19644 | Display the local variable names for the selected frame. If |
19645 | @var{print-values} is 0 or @code{--no-values}, print only the names of | |
19646 | the variables; if it is 1 or @code{--all-values}, print also their | |
19647 | values; and if it is 2 or @code{--simple-values}, print the name, | |
19648 | type and value for simple data types and the name and type for arrays, | |
19649 | structures and unions. In this last case, a frontend can immediately | |
19650 | display the value of simple data types and create variable objects for | |
19651 | other data types when the the user wishes to explore their values in | |
bc8ced35 | 19652 | more detail. |
922fbb7b AC |
19653 | |
19654 | @subsubheading @value{GDBN} Command | |
19655 | ||
19656 | @samp{info locals} in @value{GDBN}, @samp{gdb_get_locals} in @code{gdbtk}. | |
19657 | ||
19658 | @subsubheading Example | |
19659 | ||
19660 | @smallexample | |
19661 | (@value{GDBP}) | |
19662 | -stack-list-locals 0 | |
19663 | ^done,locals=[name="A",name="B",name="C"] | |
19664 | (@value{GDBP}) | |
bc8ced35 | 19665 | -stack-list-locals --all-values |
922fbb7b | 19666 | ^done,locals=[@{name="A",value="1"@},@{name="B",value="2"@}, |
bc8ced35 NR |
19667 | @{name="C",value="@{1, 2, 3@}"@}] |
19668 | -stack-list-locals --simple-values | |
19669 | ^done,locals=[@{name="A",type="int",value="1"@}, | |
19670 | @{name="B",type="int",value="2"@},@{name="C",type="int [3]"@}] | |
922fbb7b AC |
19671 | (@value{GDBP}) |
19672 | @end smallexample | |
19673 | ||
19674 | ||
19675 | @subheading The @code{-stack-select-frame} Command | |
19676 | @findex -stack-select-frame | |
19677 | ||
19678 | @subsubheading Synopsis | |
19679 | ||
19680 | @smallexample | |
19681 | -stack-select-frame @var{framenum} | |
19682 | @end smallexample | |
19683 | ||
265eeb58 | 19684 | Change the selected frame. Select a different frame @var{framenum} on |
922fbb7b AC |
19685 | the stack. |
19686 | ||
19687 | @subsubheading @value{GDBN} Command | |
19688 | ||
19689 | The corresponding @value{GDBN} commands are @samp{frame}, @samp{up}, | |
19690 | @samp{down}, @samp{select-frame}, @samp{up-silent}, and @samp{down-silent}. | |
19691 | ||
19692 | @subsubheading Example | |
19693 | ||
19694 | @smallexample | |
19695 | (@value{GDBP}) | |
19696 | -stack-select-frame 2 | |
19697 | ^done | |
19698 | (@value{GDBP}) | |
19699 | @end smallexample | |
19700 | ||
19701 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
19702 | @node GDB/MI Symbol Query | |
19703 | @section @sc{gdb/mi} Symbol Query Commands | |
19704 | ||
19705 | ||
19706 | @subheading The @code{-symbol-info-address} Command | |
19707 | @findex -symbol-info-address | |
19708 | ||
19709 | @subsubheading Synopsis | |
19710 | ||
19711 | @smallexample | |
19712 | -symbol-info-address @var{symbol} | |
19713 | @end smallexample | |
19714 | ||
19715 | Describe where @var{symbol} is stored. | |
19716 | ||
19717 | @subsubheading @value{GDBN} Command | |
19718 | ||
19719 | The corresponding @value{GDBN} command is @samp{info address}. | |
19720 | ||
19721 | @subsubheading Example | |
19722 | N.A. | |
19723 | ||
19724 | ||
19725 | @subheading The @code{-symbol-info-file} Command | |
19726 | @findex -symbol-info-file | |
19727 | ||
19728 | @subsubheading Synopsis | |
19729 | ||
19730 | @smallexample | |
19731 | -symbol-info-file | |
19732 | @end smallexample | |
19733 | ||
19734 | Show the file for the symbol. | |
19735 | ||
19736 | @subsubheading @value{GDBN} Command | |
19737 | ||
19738 | There's no equivalent @value{GDBN} command. @code{gdbtk} has | |
19739 | @samp{gdb_find_file}. | |
19740 | ||
19741 | @subsubheading Example | |
19742 | N.A. | |
19743 | ||
19744 | ||
19745 | @subheading The @code{-symbol-info-function} Command | |
19746 | @findex -symbol-info-function | |
19747 | ||
19748 | @subsubheading Synopsis | |
19749 | ||
19750 | @smallexample | |
19751 | -symbol-info-function | |
19752 | @end smallexample | |
19753 | ||
19754 | Show which function the symbol lives in. | |
19755 | ||
19756 | @subsubheading @value{GDBN} Command | |
19757 | ||
19758 | @samp{gdb_get_function} in @code{gdbtk}. | |
19759 | ||
19760 | @subsubheading Example | |
19761 | N.A. | |
19762 | ||
19763 | ||
19764 | @subheading The @code{-symbol-info-line} Command | |
19765 | @findex -symbol-info-line | |
19766 | ||
19767 | @subsubheading Synopsis | |
19768 | ||
19769 | @smallexample | |
19770 | -symbol-info-line | |
19771 | @end smallexample | |
19772 | ||
19773 | Show the core addresses of the code for a source line. | |
19774 | ||
19775 | @subsubheading @value{GDBN} Command | |
19776 | ||
71952f4c | 19777 | The corresponding @value{GDBN} command is @samp{info line}. |
922fbb7b AC |
19778 | @code{gdbtk} has the @samp{gdb_get_line} and @samp{gdb_get_file} commands. |
19779 | ||
19780 | @subsubheading Example | |
19781 | N.A. | |
19782 | ||
19783 | ||
19784 | @subheading The @code{-symbol-info-symbol} Command | |
19785 | @findex -symbol-info-symbol | |
19786 | ||
19787 | @subsubheading Synopsis | |
19788 | ||
19789 | @smallexample | |
19790 | -symbol-info-symbol @var{addr} | |
19791 | @end smallexample | |
19792 | ||
19793 | Describe what symbol is at location @var{addr}. | |
19794 | ||
19795 | @subsubheading @value{GDBN} Command | |
19796 | ||
19797 | The corresponding @value{GDBN} command is @samp{info symbol}. | |
19798 | ||
19799 | @subsubheading Example | |
19800 | N.A. | |
19801 | ||
19802 | ||
19803 | @subheading The @code{-symbol-list-functions} Command | |
19804 | @findex -symbol-list-functions | |
19805 | ||
19806 | @subsubheading Synopsis | |
19807 | ||
19808 | @smallexample | |
19809 | -symbol-list-functions | |
19810 | @end smallexample | |
19811 | ||
19812 | List the functions in the executable. | |
19813 | ||
19814 | @subsubheading @value{GDBN} Command | |
19815 | ||
19816 | @samp{info functions} in @value{GDBN}, @samp{gdb_listfunc} and | |
19817 | @samp{gdb_search} in @code{gdbtk}. | |
19818 | ||
19819 | @subsubheading Example | |
19820 | N.A. | |
19821 | ||
19822 | ||
32e7087d JB |
19823 | @subheading The @code{-symbol-list-lines} Command |
19824 | @findex -symbol-list-lines | |
19825 | ||
19826 | @subsubheading Synopsis | |
19827 | ||
19828 | @smallexample | |
19829 | -symbol-list-lines @var{filename} | |
19830 | @end smallexample | |
19831 | ||
19832 | Print the list of lines that contain code and their associated program | |
19833 | addresses for the given source filename. The entries are sorted in | |
19834 | ascending PC order. | |
19835 | ||
19836 | @subsubheading @value{GDBN} Command | |
19837 | ||
19838 | There is no corresponding @value{GDBN} command. | |
19839 | ||
19840 | @subsubheading Example | |
19841 | @smallexample | |
19842 | (@value{GDBP}) | |
19843 | -symbol-list-lines basics.c | |
54ff5908 | 19844 | ^done,lines=[@{pc="0x08048554",line="7"@},@{pc="0x0804855a",line="8"@}] |
32e7087d JB |
19845 | (@value{GDBP}) |
19846 | @end smallexample | |
19847 | ||
19848 | ||
922fbb7b AC |
19849 | @subheading The @code{-symbol-list-types} Command |
19850 | @findex -symbol-list-types | |
19851 | ||
19852 | @subsubheading Synopsis | |
19853 | ||
19854 | @smallexample | |
19855 | -symbol-list-types | |
19856 | @end smallexample | |
19857 | ||
19858 | List all the type names. | |
19859 | ||
19860 | @subsubheading @value{GDBN} Command | |
19861 | ||
19862 | The corresponding commands are @samp{info types} in @value{GDBN}, | |
19863 | @samp{gdb_search} in @code{gdbtk}. | |
19864 | ||
19865 | @subsubheading Example | |
19866 | N.A. | |
19867 | ||
19868 | ||
19869 | @subheading The @code{-symbol-list-variables} Command | |
19870 | @findex -symbol-list-variables | |
19871 | ||
19872 | @subsubheading Synopsis | |
19873 | ||
19874 | @smallexample | |
19875 | -symbol-list-variables | |
19876 | @end smallexample | |
19877 | ||
19878 | List all the global and static variable names. | |
19879 | ||
19880 | @subsubheading @value{GDBN} Command | |
19881 | ||
19882 | @samp{info variables} in @value{GDBN}, @samp{gdb_search} in @code{gdbtk}. | |
19883 | ||
19884 | @subsubheading Example | |
19885 | N.A. | |
19886 | ||
19887 | ||
19888 | @subheading The @code{-symbol-locate} Command | |
19889 | @findex -symbol-locate | |
19890 | ||
19891 | @subsubheading Synopsis | |
19892 | ||
19893 | @smallexample | |
19894 | -symbol-locate | |
19895 | @end smallexample | |
19896 | ||
19897 | @subsubheading @value{GDBN} Command | |
19898 | ||
19899 | @samp{gdb_loc} in @code{gdbtk}. | |
19900 | ||
19901 | @subsubheading Example | |
19902 | N.A. | |
19903 | ||
19904 | ||
19905 | @subheading The @code{-symbol-type} Command | |
19906 | @findex -symbol-type | |
19907 | ||
19908 | @subsubheading Synopsis | |
19909 | ||
19910 | @smallexample | |
19911 | -symbol-type @var{variable} | |
19912 | @end smallexample | |
19913 | ||
19914 | Show type of @var{variable}. | |
19915 | ||
19916 | @subsubheading @value{GDBN} Command | |
19917 | ||
19918 | The corresponding @value{GDBN} command is @samp{ptype}, @code{gdbtk} has | |
19919 | @samp{gdb_obj_variable}. | |
19920 | ||
19921 | @subsubheading Example | |
19922 | N.A. | |
19923 | ||
19924 | ||
19925 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
19926 | @node GDB/MI Target Manipulation | |
19927 | @section @sc{gdb/mi} Target Manipulation Commands | |
19928 | ||
19929 | ||
19930 | @subheading The @code{-target-attach} Command | |
19931 | @findex -target-attach | |
19932 | ||
19933 | @subsubheading Synopsis | |
19934 | ||
19935 | @smallexample | |
19936 | -target-attach @var{pid} | @var{file} | |
19937 | @end smallexample | |
19938 | ||
19939 | Attach to a process @var{pid} or a file @var{file} outside of @value{GDBN}. | |
19940 | ||
19941 | @subsubheading @value{GDBN} command | |
19942 | ||
19943 | The corresponding @value{GDBN} command is @samp{attach}. | |
19944 | ||
19945 | @subsubheading Example | |
19946 | N.A. | |
19947 | ||
19948 | ||
19949 | @subheading The @code{-target-compare-sections} Command | |
19950 | @findex -target-compare-sections | |
19951 | ||
19952 | @subsubheading Synopsis | |
19953 | ||
19954 | @smallexample | |
19955 | -target-compare-sections [ @var{section} ] | |
19956 | @end smallexample | |
19957 | ||
19958 | Compare data of section @var{section} on target to the exec file. | |
19959 | Without the argument, all sections are compared. | |
19960 | ||
19961 | @subsubheading @value{GDBN} Command | |
19962 | ||
19963 | The @value{GDBN} equivalent is @samp{compare-sections}. | |
19964 | ||
19965 | @subsubheading Example | |
19966 | N.A. | |
19967 | ||
19968 | ||
19969 | @subheading The @code{-target-detach} Command | |
19970 | @findex -target-detach | |
19971 | ||
19972 | @subsubheading Synopsis | |
19973 | ||
19974 | @smallexample | |
19975 | -target-detach | |
19976 | @end smallexample | |
19977 | ||
19978 | Disconnect from the remote target. There's no output. | |
19979 | ||
19980 | @subsubheading @value{GDBN} command | |
19981 | ||
19982 | The corresponding @value{GDBN} command is @samp{detach}. | |
19983 | ||
19984 | @subsubheading Example | |
19985 | ||
19986 | @smallexample | |
19987 | (@value{GDBP}) | |
19988 | -target-detach | |
19989 | ^done | |
19990 | (@value{GDBP}) | |
19991 | @end smallexample | |
19992 | ||
19993 | ||
07f31aa6 DJ |
19994 | @subheading The @code{-target-disconnect} Command |
19995 | @findex -target-disconnect | |
19996 | ||
19997 | @subsubheading Synopsis | |
19998 | ||
19999 | @example | |
20000 | -target-disconnect | |
20001 | @end example | |
20002 | ||
20003 | Disconnect from the remote target. There's no output. | |
20004 | ||
20005 | @subsubheading @value{GDBN} command | |
20006 | ||
20007 | The corresponding @value{GDBN} command is @samp{disconnect}. | |
20008 | ||
20009 | @subsubheading Example | |
20010 | ||
20011 | @smallexample | |
20012 | (@value{GDBP}) | |
20013 | -target-disconnect | |
20014 | ^done | |
20015 | (@value{GDBP}) | |
20016 | @end smallexample | |
20017 | ||
20018 | ||
922fbb7b AC |
20019 | @subheading The @code{-target-download} Command |
20020 | @findex -target-download | |
20021 | ||
20022 | @subsubheading Synopsis | |
20023 | ||
20024 | @smallexample | |
20025 | -target-download | |
20026 | @end smallexample | |
20027 | ||
20028 | Loads the executable onto the remote target. | |
20029 | It prints out an update message every half second, which includes the fields: | |
20030 | ||
20031 | @table @samp | |
20032 | @item section | |
20033 | The name of the section. | |
20034 | @item section-sent | |
20035 | The size of what has been sent so far for that section. | |
20036 | @item section-size | |
20037 | The size of the section. | |
20038 | @item total-sent | |
20039 | The total size of what was sent so far (the current and the previous sections). | |
20040 | @item total-size | |
20041 | The size of the overall executable to download. | |
20042 | @end table | |
20043 | ||
20044 | @noindent | |
20045 | Each message is sent as status record (@pxref{GDB/MI Output Syntax, , | |
20046 | @sc{gdb/mi} Output Syntax}). | |
20047 | ||
20048 | In addition, it prints the name and size of the sections, as they are | |
20049 | downloaded. These messages include the following fields: | |
20050 | ||
20051 | @table @samp | |
20052 | @item section | |
20053 | The name of the section. | |
20054 | @item section-size | |
20055 | The size of the section. | |
20056 | @item total-size | |
20057 | The size of the overall executable to download. | |
20058 | @end table | |
20059 | ||
20060 | @noindent | |
20061 | At the end, a summary is printed. | |
20062 | ||
20063 | @subsubheading @value{GDBN} Command | |
20064 | ||
20065 | The corresponding @value{GDBN} command is @samp{load}. | |
20066 | ||
20067 | @subsubheading Example | |
20068 | ||
20069 | Note: each status message appears on a single line. Here the messages | |
20070 | have been broken down so that they can fit onto a page. | |
20071 | ||
20072 | @smallexample | |
20073 | (@value{GDBP}) | |
20074 | -target-download | |
20075 | +download,@{section=".text",section-size="6668",total-size="9880"@} | |
20076 | +download,@{section=".text",section-sent="512",section-size="6668", | |
20077 | total-sent="512",total-size="9880"@} | |
20078 | +download,@{section=".text",section-sent="1024",section-size="6668", | |
20079 | total-sent="1024",total-size="9880"@} | |
20080 | +download,@{section=".text",section-sent="1536",section-size="6668", | |
20081 | total-sent="1536",total-size="9880"@} | |
20082 | +download,@{section=".text",section-sent="2048",section-size="6668", | |
20083 | total-sent="2048",total-size="9880"@} | |
20084 | +download,@{section=".text",section-sent="2560",section-size="6668", | |
20085 | total-sent="2560",total-size="9880"@} | |
20086 | +download,@{section=".text",section-sent="3072",section-size="6668", | |
20087 | total-sent="3072",total-size="9880"@} | |
20088 | +download,@{section=".text",section-sent="3584",section-size="6668", | |
20089 | total-sent="3584",total-size="9880"@} | |
20090 | +download,@{section=".text",section-sent="4096",section-size="6668", | |
20091 | total-sent="4096",total-size="9880"@} | |
20092 | +download,@{section=".text",section-sent="4608",section-size="6668", | |
20093 | total-sent="4608",total-size="9880"@} | |
20094 | +download,@{section=".text",section-sent="5120",section-size="6668", | |
20095 | total-sent="5120",total-size="9880"@} | |
20096 | +download,@{section=".text",section-sent="5632",section-size="6668", | |
20097 | total-sent="5632",total-size="9880"@} | |
20098 | +download,@{section=".text",section-sent="6144",section-size="6668", | |
20099 | total-sent="6144",total-size="9880"@} | |
20100 | +download,@{section=".text",section-sent="6656",section-size="6668", | |
20101 | total-sent="6656",total-size="9880"@} | |
20102 | +download,@{section=".init",section-size="28",total-size="9880"@} | |
20103 | +download,@{section=".fini",section-size="28",total-size="9880"@} | |
20104 | +download,@{section=".data",section-size="3156",total-size="9880"@} | |
20105 | +download,@{section=".data",section-sent="512",section-size="3156", | |
20106 | total-sent="7236",total-size="9880"@} | |
20107 | +download,@{section=".data",section-sent="1024",section-size="3156", | |
20108 | total-sent="7748",total-size="9880"@} | |
20109 | +download,@{section=".data",section-sent="1536",section-size="3156", | |
20110 | total-sent="8260",total-size="9880"@} | |
20111 | +download,@{section=".data",section-sent="2048",section-size="3156", | |
20112 | total-sent="8772",total-size="9880"@} | |
20113 | +download,@{section=".data",section-sent="2560",section-size="3156", | |
20114 | total-sent="9284",total-size="9880"@} | |
20115 | +download,@{section=".data",section-sent="3072",section-size="3156", | |
20116 | total-sent="9796",total-size="9880"@} | |
20117 | ^done,address="0x10004",load-size="9880",transfer-rate="6586", | |
20118 | write-rate="429" | |
20119 | (@value{GDBP}) | |
20120 | @end smallexample | |
20121 | ||
20122 | ||
20123 | @subheading The @code{-target-exec-status} Command | |
20124 | @findex -target-exec-status | |
20125 | ||
20126 | @subsubheading Synopsis | |
20127 | ||
20128 | @smallexample | |
20129 | -target-exec-status | |
20130 | @end smallexample | |
20131 | ||
20132 | Provide information on the state of the target (whether it is running or | |
20133 | not, for instance). | |
20134 | ||
20135 | @subsubheading @value{GDBN} Command | |
20136 | ||
20137 | There's no equivalent @value{GDBN} command. | |
20138 | ||
20139 | @subsubheading Example | |
20140 | N.A. | |
20141 | ||
20142 | ||
20143 | @subheading The @code{-target-list-available-targets} Command | |
20144 | @findex -target-list-available-targets | |
20145 | ||
20146 | @subsubheading Synopsis | |
20147 | ||
20148 | @smallexample | |
20149 | -target-list-available-targets | |
20150 | @end smallexample | |
20151 | ||
20152 | List the possible targets to connect to. | |
20153 | ||
20154 | @subsubheading @value{GDBN} Command | |
20155 | ||
20156 | The corresponding @value{GDBN} command is @samp{help target}. | |
20157 | ||
20158 | @subsubheading Example | |
20159 | N.A. | |
20160 | ||
20161 | ||
20162 | @subheading The @code{-target-list-current-targets} Command | |
20163 | @findex -target-list-current-targets | |
20164 | ||
20165 | @subsubheading Synopsis | |
20166 | ||
20167 | @smallexample | |
20168 | -target-list-current-targets | |
20169 | @end smallexample | |
20170 | ||
20171 | Describe the current target. | |
20172 | ||
20173 | @subsubheading @value{GDBN} Command | |
20174 | ||
20175 | The corresponding information is printed by @samp{info file} (among | |
20176 | other things). | |
20177 | ||
20178 | @subsubheading Example | |
20179 | N.A. | |
20180 | ||
20181 | ||
20182 | @subheading The @code{-target-list-parameters} Command | |
20183 | @findex -target-list-parameters | |
20184 | ||
20185 | @subsubheading Synopsis | |
20186 | ||
20187 | @smallexample | |
20188 | -target-list-parameters | |
20189 | @end smallexample | |
20190 | ||
20191 | @c ???? | |
20192 | ||
20193 | @subsubheading @value{GDBN} Command | |
20194 | ||
20195 | No equivalent. | |
20196 | ||
20197 | @subsubheading Example | |
20198 | N.A. | |
20199 | ||
20200 | ||
20201 | @subheading The @code{-target-select} Command | |
20202 | @findex -target-select | |
20203 | ||
20204 | @subsubheading Synopsis | |
20205 | ||
20206 | @smallexample | |
20207 | -target-select @var{type} @var{parameters @dots{}} | |
20208 | @end smallexample | |
20209 | ||
20210 | Connect @value{GDBN} to the remote target. This command takes two args: | |
20211 | ||
20212 | @table @samp | |
20213 | @item @var{type} | |
20214 | The type of target, for instance @samp{async}, @samp{remote}, etc. | |
20215 | @item @var{parameters} | |
20216 | Device names, host names and the like. @xref{Target Commands, , | |
20217 | Commands for managing targets}, for more details. | |
20218 | @end table | |
20219 | ||
20220 | The output is a connection notification, followed by the address at | |
20221 | which the target program is, in the following form: | |
20222 | ||
20223 | @smallexample | |
20224 | ^connected,addr="@var{address}",func="@var{function name}", | |
20225 | args=[@var{arg list}] | |
20226 | @end smallexample | |
20227 | ||
20228 | @subsubheading @value{GDBN} Command | |
20229 | ||
20230 | The corresponding @value{GDBN} command is @samp{target}. | |
20231 | ||
20232 | @subsubheading Example | |
20233 | ||
20234 | @smallexample | |
20235 | (@value{GDBP}) | |
20236 | -target-select async /dev/ttya | |
20237 | ^connected,addr="0xfe00a300",func="??",args=[] | |
20238 | (@value{GDBP}) | |
20239 | @end smallexample | |
20240 | ||
20241 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
20242 | @node GDB/MI Thread Commands | |
20243 | @section @sc{gdb/mi} Thread Commands | |
20244 | ||
20245 | ||
20246 | @subheading The @code{-thread-info} Command | |
20247 | @findex -thread-info | |
20248 | ||
20249 | @subsubheading Synopsis | |
20250 | ||
20251 | @smallexample | |
20252 | -thread-info | |
20253 | @end smallexample | |
20254 | ||
20255 | @subsubheading @value{GDBN} command | |
20256 | ||
20257 | No equivalent. | |
20258 | ||
20259 | @subsubheading Example | |
20260 | N.A. | |
20261 | ||
20262 | ||
20263 | @subheading The @code{-thread-list-all-threads} Command | |
20264 | @findex -thread-list-all-threads | |
20265 | ||
20266 | @subsubheading Synopsis | |
20267 | ||
20268 | @smallexample | |
20269 | -thread-list-all-threads | |
20270 | @end smallexample | |
20271 | ||
20272 | @subsubheading @value{GDBN} Command | |
20273 | ||
20274 | The equivalent @value{GDBN} command is @samp{info threads}. | |
20275 | ||
20276 | @subsubheading Example | |
20277 | N.A. | |
20278 | ||
20279 | ||
20280 | @subheading The @code{-thread-list-ids} Command | |
20281 | @findex -thread-list-ids | |
20282 | ||
20283 | @subsubheading Synopsis | |
20284 | ||
20285 | @smallexample | |
20286 | -thread-list-ids | |
20287 | @end smallexample | |
20288 | ||
20289 | Produces a list of the currently known @value{GDBN} thread ids. At the | |
20290 | end of the list it also prints the total number of such threads. | |
20291 | ||
20292 | @subsubheading @value{GDBN} Command | |
20293 | ||
20294 | Part of @samp{info threads} supplies the same information. | |
20295 | ||
20296 | @subsubheading Example | |
20297 | ||
20298 | No threads present, besides the main process: | |
20299 | ||
20300 | @smallexample | |
20301 | (@value{GDBP}) | |
20302 | -thread-list-ids | |
20303 | ^done,thread-ids=@{@},number-of-threads="0" | |
20304 | (@value{GDBP}) | |
20305 | @end smallexample | |
20306 | ||
20307 | ||
20308 | Several threads: | |
20309 | ||
20310 | @smallexample | |
20311 | (@value{GDBP}) | |
20312 | -thread-list-ids | |
20313 | ^done,thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
20314 | number-of-threads="3" | |
20315 | (@value{GDBP}) | |
20316 | @end smallexample | |
20317 | ||
20318 | ||
20319 | @subheading The @code{-thread-select} Command | |
20320 | @findex -thread-select | |
20321 | ||
20322 | @subsubheading Synopsis | |
20323 | ||
20324 | @smallexample | |
20325 | -thread-select @var{threadnum} | |
20326 | @end smallexample | |
20327 | ||
20328 | Make @var{threadnum} the current thread. It prints the number of the new | |
20329 | current thread, and the topmost frame for that thread. | |
20330 | ||
20331 | @subsubheading @value{GDBN} Command | |
20332 | ||
20333 | The corresponding @value{GDBN} command is @samp{thread}. | |
20334 | ||
20335 | @subsubheading Example | |
20336 | ||
20337 | @smallexample | |
20338 | (@value{GDBP}) | |
20339 | -exec-next | |
20340 | ^running | |
20341 | (@value{GDBP}) | |
20342 | *stopped,reason="end-stepping-range",thread-id="2",line="187", | |
20343 | file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c" | |
20344 | (@value{GDBP}) | |
20345 | -thread-list-ids | |
20346 | ^done, | |
20347 | thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
20348 | number-of-threads="3" | |
20349 | (@value{GDBP}) | |
20350 | -thread-select 3 | |
20351 | ^done,new-thread-id="3", | |
20352 | frame=@{level="0",func="vprintf", | |
20353 | args=[@{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""@}, | |
20354 | @{name="arg",value="0x2"@}],file="vprintf.c",line="31"@} | |
20355 | (@value{GDBP}) | |
20356 | @end smallexample | |
20357 | ||
20358 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
20359 | @node GDB/MI Tracepoint Commands | |
20360 | @section @sc{gdb/mi} Tracepoint Commands | |
20361 | ||
20362 | The tracepoint commands are not yet implemented. | |
20363 | ||
20364 | @c @subheading -trace-actions | |
20365 | ||
20366 | @c @subheading -trace-delete | |
20367 | ||
20368 | @c @subheading -trace-disable | |
20369 | ||
20370 | @c @subheading -trace-dump | |
20371 | ||
20372 | @c @subheading -trace-enable | |
20373 | ||
20374 | @c @subheading -trace-exists | |
20375 | ||
20376 | @c @subheading -trace-find | |
20377 | ||
20378 | @c @subheading -trace-frame-number | |
20379 | ||
20380 | @c @subheading -trace-info | |
20381 | ||
20382 | @c @subheading -trace-insert | |
20383 | ||
20384 | @c @subheading -trace-list | |
20385 | ||
20386 | @c @subheading -trace-pass-count | |
20387 | ||
20388 | @c @subheading -trace-save | |
20389 | ||
20390 | @c @subheading -trace-start | |
20391 | ||
20392 | @c @subheading -trace-stop | |
20393 | ||
20394 | ||
20395 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
20396 | @node GDB/MI Variable Objects | |
20397 | @section @sc{gdb/mi} Variable Objects | |
20398 | ||
20399 | ||
20400 | @subheading Motivation for Variable Objects in @sc{gdb/mi} | |
20401 | ||
20402 | For the implementation of a variable debugger window (locals, watched | |
20403 | expressions, etc.), we are proposing the adaptation of the existing code | |
20404 | used by @code{Insight}. | |
20405 | ||
20406 | The two main reasons for that are: | |
20407 | ||
20408 | @enumerate 1 | |
20409 | @item | |
20410 | It has been proven in practice (it is already on its second generation). | |
20411 | ||
20412 | @item | |
20413 | It will shorten development time (needless to say how important it is | |
20414 | now). | |
20415 | @end enumerate | |
20416 | ||
20417 | The original interface was designed to be used by Tcl code, so it was | |
20418 | slightly changed so it could be used through @sc{gdb/mi}. This section | |
20419 | describes the @sc{gdb/mi} operations that will be available and gives some | |
20420 | hints about their use. | |
20421 | ||
20422 | @emph{Note}: In addition to the set of operations described here, we | |
20423 | expect the @sc{gui} implementation of a variable window to require, at | |
20424 | least, the following operations: | |
20425 | ||
20426 | @itemize @bullet | |
20427 | @item @code{-gdb-show} @code{output-radix} | |
20428 | @item @code{-stack-list-arguments} | |
20429 | @item @code{-stack-list-locals} | |
20430 | @item @code{-stack-select-frame} | |
20431 | @end itemize | |
20432 | ||
20433 | @subheading Introduction to Variable Objects in @sc{gdb/mi} | |
20434 | ||
20435 | @cindex variable objects in @sc{gdb/mi} | |
20436 | The basic idea behind variable objects is the creation of a named object | |
20437 | to represent a variable, an expression, a memory location or even a CPU | |
20438 | register. For each object created, a set of operations is available for | |
20439 | examining or changing its properties. | |
20440 | ||
20441 | Furthermore, complex data types, such as C structures, are represented | |
20442 | in a tree format. For instance, the @code{struct} type variable is the | |
20443 | root and the children will represent the struct members. If a child | |
20444 | is itself of a complex type, it will also have children of its own. | |
20445 | Appropriate language differences are handled for C, C@t{++} and Java. | |
20446 | ||
20447 | When returning the actual values of the objects, this facility allows | |
20448 | for the individual selection of the display format used in the result | |
20449 | creation. It can be chosen among: binary, decimal, hexadecimal, octal | |
20450 | and natural. Natural refers to a default format automatically | |
20451 | chosen based on the variable type (like decimal for an @code{int}, hex | |
20452 | for pointers, etc.). | |
20453 | ||
20454 | The following is the complete set of @sc{gdb/mi} operations defined to | |
20455 | access this functionality: | |
20456 | ||
20457 | @multitable @columnfractions .4 .6 | |
20458 | @item @strong{Operation} | |
20459 | @tab @strong{Description} | |
20460 | ||
20461 | @item @code{-var-create} | |
20462 | @tab create a variable object | |
20463 | @item @code{-var-delete} | |
20464 | @tab delete the variable object and its children | |
20465 | @item @code{-var-set-format} | |
20466 | @tab set the display format of this variable | |
20467 | @item @code{-var-show-format} | |
20468 | @tab show the display format of this variable | |
20469 | @item @code{-var-info-num-children} | |
20470 | @tab tells how many children this object has | |
20471 | @item @code{-var-list-children} | |
20472 | @tab return a list of the object's children | |
20473 | @item @code{-var-info-type} | |
20474 | @tab show the type of this variable object | |
20475 | @item @code{-var-info-expression} | |
20476 | @tab print what this variable object represents | |
20477 | @item @code{-var-show-attributes} | |
20478 | @tab is this variable editable? does it exist here? | |
20479 | @item @code{-var-evaluate-expression} | |
20480 | @tab get the value of this variable | |
20481 | @item @code{-var-assign} | |
20482 | @tab set the value of this variable | |
20483 | @item @code{-var-update} | |
20484 | @tab update the variable and its children | |
20485 | @end multitable | |
20486 | ||
20487 | In the next subsection we describe each operation in detail and suggest | |
20488 | how it can be used. | |
20489 | ||
20490 | @subheading Description And Use of Operations on Variable Objects | |
20491 | ||
20492 | @subheading The @code{-var-create} Command | |
20493 | @findex -var-create | |
20494 | ||
20495 | @subsubheading Synopsis | |
20496 | ||
20497 | @smallexample | |
20498 | -var-create @{@var{name} | "-"@} | |
20499 | @{@var{frame-addr} | "*"@} @var{expression} | |
20500 | @end smallexample | |
20501 | ||
20502 | This operation creates a variable object, which allows the monitoring of | |
20503 | a variable, the result of an expression, a memory cell or a CPU | |
20504 | register. | |
20505 | ||
20506 | The @var{name} parameter is the string by which the object can be | |
20507 | referenced. It must be unique. If @samp{-} is specified, the varobj | |
20508 | system will generate a string ``varNNNNNN'' automatically. It will be | |
20509 | unique provided that one does not specify @var{name} on that format. | |
20510 | The command fails if a duplicate name is found. | |
20511 | ||
20512 | The frame under which the expression should be evaluated can be | |
20513 | specified by @var{frame-addr}. A @samp{*} indicates that the current | |
20514 | frame should be used. | |
20515 | ||
20516 | @var{expression} is any expression valid on the current language set (must not | |
20517 | begin with a @samp{*}), or one of the following: | |
20518 | ||
20519 | @itemize @bullet | |
20520 | @item | |
20521 | @samp{*@var{addr}}, where @var{addr} is the address of a memory cell | |
20522 | ||
20523 | @item | |
20524 | @samp{*@var{addr}-@var{addr}} --- a memory address range (TBD) | |
20525 | ||
20526 | @item | |
20527 | @samp{$@var{regname}} --- a CPU register name | |
20528 | @end itemize | |
20529 | ||
20530 | @subsubheading Result | |
20531 | ||
20532 | This operation returns the name, number of children and the type of the | |
20533 | object created. Type is returned as a string as the ones generated by | |
20534 | the @value{GDBN} CLI: | |
20535 | ||
20536 | @smallexample | |
20537 | name="@var{name}",numchild="N",type="@var{type}" | |
20538 | @end smallexample | |
20539 | ||
20540 | ||
20541 | @subheading The @code{-var-delete} Command | |
20542 | @findex -var-delete | |
20543 | ||
20544 | @subsubheading Synopsis | |
20545 | ||
20546 | @smallexample | |
20547 | -var-delete @var{name} | |
20548 | @end smallexample | |
20549 | ||
20550 | Deletes a previously created variable object and all of its children. | |
20551 | ||
20552 | Returns an error if the object @var{name} is not found. | |
20553 | ||
20554 | ||
20555 | @subheading The @code{-var-set-format} Command | |
20556 | @findex -var-set-format | |
20557 | ||
20558 | @subsubheading Synopsis | |
20559 | ||
20560 | @smallexample | |
20561 | -var-set-format @var{name} @var{format-spec} | |
20562 | @end smallexample | |
20563 | ||
20564 | Sets the output format for the value of the object @var{name} to be | |
20565 | @var{format-spec}. | |
20566 | ||
20567 | The syntax for the @var{format-spec} is as follows: | |
20568 | ||
20569 | @smallexample | |
20570 | @var{format-spec} @expansion{} | |
20571 | @{binary | decimal | hexadecimal | octal | natural@} | |
20572 | @end smallexample | |
20573 | ||
20574 | ||
20575 | @subheading The @code{-var-show-format} Command | |
20576 | @findex -var-show-format | |
20577 | ||
20578 | @subsubheading Synopsis | |
20579 | ||
20580 | @smallexample | |
20581 | -var-show-format @var{name} | |
20582 | @end smallexample | |
20583 | ||
20584 | Returns the format used to display the value of the object @var{name}. | |
20585 | ||
20586 | @smallexample | |
20587 | @var{format} @expansion{} | |
20588 | @var{format-spec} | |
20589 | @end smallexample | |
20590 | ||
20591 | ||
20592 | @subheading The @code{-var-info-num-children} Command | |
20593 | @findex -var-info-num-children | |
20594 | ||
20595 | @subsubheading Synopsis | |
20596 | ||
20597 | @smallexample | |
20598 | -var-info-num-children @var{name} | |
20599 | @end smallexample | |
20600 | ||
20601 | Returns the number of children of a variable object @var{name}: | |
20602 | ||
20603 | @smallexample | |
20604 | numchild=@var{n} | |
20605 | @end smallexample | |
20606 | ||
20607 | ||
20608 | @subheading The @code{-var-list-children} Command | |
20609 | @findex -var-list-children | |
20610 | ||
20611 | @subsubheading Synopsis | |
20612 | ||
20613 | @smallexample | |
bc8ced35 | 20614 | -var-list-children [@var{print-values}] @var{name} |
922fbb7b | 20615 | @end smallexample |
265eeb58 | 20616 | @anchor{-var-list-children} |
922fbb7b | 20617 | |
265eeb58 NR |
20618 | Return a list of the children of the specified variable object and |
20619 | create variable objects for them, if they do not already exist. With | |
20620 | a single argument or if @var{print-values} has a value for of 0 or | |
20621 | @code{--no-values}, print only the names of the variables; if | |
20622 | @var{print-values} is 1 or @code{--all-values}, also print their | |
20623 | values; and if it is 2 or @code{--simple-values} print the name and | |
20624 | value for simple data types and just the name for arrays, structures | |
20625 | and unions. | |
bc8ced35 NR |
20626 | |
20627 | @subsubheading Example | |
922fbb7b AC |
20628 | |
20629 | @smallexample | |
bc8ced35 NR |
20630 | (@value{GDBP}) |
20631 | -var-list-children n | |
265eeb58 | 20632 | ^done,numchild=@var{n},children=[@{name=@var{name}, |
922fbb7b | 20633 | numchild=@var{n},type=@var{type}@},@r{(repeats N times)}] |
bc8ced35 NR |
20634 | (@value{GDBP}) |
20635 | -var-list-children --all-values n | |
265eeb58 | 20636 | ^done,numchild=@var{n},children=[@{name=@var{name}, |
bc8ced35 | 20637 | numchild=@var{n},value=@var{value},type=@var{type}@},@r{(repeats N times)}] |
922fbb7b AC |
20638 | @end smallexample |
20639 | ||
20640 | ||
20641 | @subheading The @code{-var-info-type} Command | |
20642 | @findex -var-info-type | |
20643 | ||
20644 | @subsubheading Synopsis | |
20645 | ||
20646 | @smallexample | |
20647 | -var-info-type @var{name} | |
20648 | @end smallexample | |
20649 | ||
20650 | Returns the type of the specified variable @var{name}. The type is | |
20651 | returned as a string in the same format as it is output by the | |
20652 | @value{GDBN} CLI: | |
20653 | ||
20654 | @smallexample | |
20655 | type=@var{typename} | |
20656 | @end smallexample | |
20657 | ||
20658 | ||
20659 | @subheading The @code{-var-info-expression} Command | |
20660 | @findex -var-info-expression | |
20661 | ||
20662 | @subsubheading Synopsis | |
20663 | ||
20664 | @smallexample | |
20665 | -var-info-expression @var{name} | |
20666 | @end smallexample | |
20667 | ||
20668 | Returns what is represented by the variable object @var{name}: | |
20669 | ||
20670 | @smallexample | |
20671 | lang=@var{lang-spec},exp=@var{expression} | |
20672 | @end smallexample | |
20673 | ||
20674 | @noindent | |
20675 | where @var{lang-spec} is @code{@{"C" | "C++" | "Java"@}}. | |
20676 | ||
20677 | @subheading The @code{-var-show-attributes} Command | |
20678 | @findex -var-show-attributes | |
20679 | ||
20680 | @subsubheading Synopsis | |
20681 | ||
20682 | @smallexample | |
20683 | -var-show-attributes @var{name} | |
20684 | @end smallexample | |
20685 | ||
20686 | List attributes of the specified variable object @var{name}: | |
20687 | ||
20688 | @smallexample | |
20689 | status=@var{attr} [ ( ,@var{attr} )* ] | |
20690 | @end smallexample | |
20691 | ||
20692 | @noindent | |
20693 | where @var{attr} is @code{@{ @{ editable | noneditable @} | TBD @}}. | |
20694 | ||
20695 | @subheading The @code{-var-evaluate-expression} Command | |
20696 | @findex -var-evaluate-expression | |
20697 | ||
20698 | @subsubheading Synopsis | |
20699 | ||
20700 | @smallexample | |
20701 | -var-evaluate-expression @var{name} | |
20702 | @end smallexample | |
20703 | ||
20704 | Evaluates the expression that is represented by the specified variable | |
20705 | object and returns its value as a string in the current format specified | |
20706 | for the object: | |
20707 | ||
20708 | @smallexample | |
20709 | value=@var{value} | |
20710 | @end smallexample | |
20711 | ||
20712 | Note that one must invoke @code{-var-list-children} for a variable | |
20713 | before the value of a child variable can be evaluated. | |
20714 | ||
20715 | @subheading The @code{-var-assign} Command | |
20716 | @findex -var-assign | |
20717 | ||
20718 | @subsubheading Synopsis | |
20719 | ||
20720 | @smallexample | |
20721 | -var-assign @var{name} @var{expression} | |
20722 | @end smallexample | |
20723 | ||
20724 | Assigns the value of @var{expression} to the variable object specified | |
20725 | by @var{name}. The object must be @samp{editable}. If the variable's | |
b383017d | 20726 | value is altered by the assign, the variable will show up in any |
922fbb7b AC |
20727 | subsequent @code{-var-update} list. |
20728 | ||
20729 | @subsubheading Example | |
20730 | ||
20731 | @smallexample | |
20732 | (@value{GDBP}) | |
20733 | -var-assign var1 3 | |
20734 | ^done,value="3" | |
20735 | (@value{GDBP}) | |
20736 | -var-update * | |
20737 | ^done,changelist=[@{name="var1",in_scope="true",type_changed="false"@}] | |
20738 | (@value{GDBP}) | |
20739 | @end smallexample | |
20740 | ||
20741 | @subheading The @code{-var-update} Command | |
20742 | @findex -var-update | |
20743 | ||
20744 | @subsubheading Synopsis | |
20745 | ||
20746 | @smallexample | |
265eeb58 | 20747 | -var-update [@var{print-values}] @{@var{name} | "*"@} |
922fbb7b AC |
20748 | @end smallexample |
20749 | ||
20750 | Update the value of the variable object @var{name} by evaluating its | |
20751 | expression after fetching all the new values from memory or registers. | |
265eeb58 | 20752 | A @samp{*} causes all existing variable objects to be updated. The |
656d5e12 EZ |
20753 | option @var{print-values} determines whether names both and values, or |
20754 | just names are printed in the manner described for | |
20755 | @code{-var-list-children} (@pxref{-var-list-children}). | |
265eeb58 NR |
20756 | |
20757 | @subsubheading Example | |
922fbb7b | 20758 | |
265eeb58 NR |
20759 | @smallexample |
20760 | (@value{GDBP}) | |
20761 | -var-assign var1 3 | |
20762 | ^done,value="3" | |
20763 | (@value{GDBP}) | |
20764 | -var-update --all-values var1 | |
20765 | ^done,changelist=[@{name="var1",value="3",in_scope="true", | |
20766 | type_changed="false"@}] | |
20767 | (@value{GDBP}) | |
20768 | @end smallexample | |
922fbb7b AC |
20769 | |
20770 | @node Annotations | |
20771 | @chapter @value{GDBN} Annotations | |
20772 | ||
086432e2 AC |
20773 | This chapter describes annotations in @value{GDBN}. Annotations were |
20774 | designed to interface @value{GDBN} to graphical user interfaces or other | |
20775 | similar programs which want to interact with @value{GDBN} at a | |
922fbb7b AC |
20776 | relatively high level. |
20777 | ||
086432e2 AC |
20778 | The annotation mechanism has largely been superseeded by @sc{gdb/mi} |
20779 | (@pxref{GDB/MI}). | |
20780 | ||
922fbb7b AC |
20781 | @ignore |
20782 | This is Edition @value{EDITION}, @value{DATE}. | |
20783 | @end ignore | |
20784 | ||
20785 | @menu | |
20786 | * Annotations Overview:: What annotations are; the general syntax. | |
922fbb7b AC |
20787 | * Prompting:: Annotations marking @value{GDBN}'s need for input. |
20788 | * Errors:: Annotations for error messages. | |
922fbb7b AC |
20789 | * Invalidation:: Some annotations describe things now invalid. |
20790 | * Annotations for Running:: | |
20791 | Whether the program is running, how it stopped, etc. | |
20792 | * Source Annotations:: Annotations describing source code. | |
922fbb7b AC |
20793 | @end menu |
20794 | ||
20795 | @node Annotations Overview | |
20796 | @section What is an Annotation? | |
20797 | @cindex annotations | |
20798 | ||
922fbb7b AC |
20799 | Annotations start with a newline character, two @samp{control-z} |
20800 | characters, and the name of the annotation. If there is no additional | |
20801 | information associated with this annotation, the name of the annotation | |
20802 | is followed immediately by a newline. If there is additional | |
20803 | information, the name of the annotation is followed by a space, the | |
20804 | additional information, and a newline. The additional information | |
20805 | cannot contain newline characters. | |
20806 | ||
20807 | Any output not beginning with a newline and two @samp{control-z} | |
20808 | characters denotes literal output from @value{GDBN}. Currently there is | |
20809 | no need for @value{GDBN} to output a newline followed by two | |
20810 | @samp{control-z} characters, but if there was such a need, the | |
20811 | annotations could be extended with an @samp{escape} annotation which | |
20812 | means those three characters as output. | |
20813 | ||
086432e2 AC |
20814 | The annotation @var{level}, which is specified using the |
20815 | @option{--annotate} command line option (@pxref{Mode Options}), controls | |
20816 | how much information @value{GDBN} prints together with its prompt, | |
20817 | values of expressions, source lines, and other types of output. Level 0 | |
20818 | is for no anntations, level 1 is for use when @value{GDBN} is run as a | |
20819 | subprocess of @sc{gnu} Emacs, level 3 is the maximum annotation suitable | |
20820 | for programs that control @value{GDBN}, and level 2 annotations have | |
20821 | been made obsolete (@pxref{Limitations, , Limitations of the Annotation | |
09d4efe1 EZ |
20822 | Interface, annotate, GDB's Obsolete Annotations}). |
20823 | ||
20824 | @table @code | |
20825 | @kindex set annotate | |
20826 | @item set annotate @var{level} | |
e09f16f9 | 20827 | The @value{GDBN} command @code{set annotate} sets the level of |
09d4efe1 | 20828 | annotations to the specified @var{level}. |
9c16f35a EZ |
20829 | |
20830 | @item show annotate | |
20831 | @kindex show annotate | |
20832 | Show the current annotation level. | |
09d4efe1 EZ |
20833 | @end table |
20834 | ||
20835 | This chapter describes level 3 annotations. | |
086432e2 | 20836 | |
922fbb7b AC |
20837 | A simple example of starting up @value{GDBN} with annotations is: |
20838 | ||
20839 | @smallexample | |
086432e2 AC |
20840 | $ @kbd{gdb --annotate=3} |
20841 | GNU gdb 6.0 | |
20842 | Copyright 2003 Free Software Foundation, Inc. | |
922fbb7b AC |
20843 | GDB is free software, covered by the GNU General Public License, |
20844 | and you are welcome to change it and/or distribute copies of it | |
20845 | under certain conditions. | |
20846 | Type "show copying" to see the conditions. | |
20847 | There is absolutely no warranty for GDB. Type "show warranty" | |
20848 | for details. | |
086432e2 | 20849 | This GDB was configured as "i386-pc-linux-gnu" |
922fbb7b AC |
20850 | |
20851 | ^Z^Zpre-prompt | |
f7dc1244 | 20852 | (@value{GDBP}) |
922fbb7b | 20853 | ^Z^Zprompt |
086432e2 | 20854 | @kbd{quit} |
922fbb7b AC |
20855 | |
20856 | ^Z^Zpost-prompt | |
b383017d | 20857 | $ |
922fbb7b AC |
20858 | @end smallexample |
20859 | ||
20860 | Here @samp{quit} is input to @value{GDBN}; the rest is output from | |
20861 | @value{GDBN}. The three lines beginning @samp{^Z^Z} (where @samp{^Z} | |
20862 | denotes a @samp{control-z} character) are annotations; the rest is | |
20863 | output from @value{GDBN}. | |
20864 | ||
922fbb7b AC |
20865 | @node Prompting |
20866 | @section Annotation for @value{GDBN} Input | |
20867 | ||
20868 | @cindex annotations for prompts | |
20869 | When @value{GDBN} prompts for input, it annotates this fact so it is possible | |
20870 | to know when to send output, when the output from a given command is | |
20871 | over, etc. | |
20872 | ||
20873 | Different kinds of input each have a different @dfn{input type}. Each | |
20874 | input type has three annotations: a @code{pre-} annotation, which | |
20875 | denotes the beginning of any prompt which is being output, a plain | |
20876 | annotation, which denotes the end of the prompt, and then a @code{post-} | |
20877 | annotation which denotes the end of any echo which may (or may not) be | |
20878 | associated with the input. For example, the @code{prompt} input type | |
20879 | features the following annotations: | |
20880 | ||
20881 | @smallexample | |
20882 | ^Z^Zpre-prompt | |
20883 | ^Z^Zprompt | |
20884 | ^Z^Zpost-prompt | |
20885 | @end smallexample | |
20886 | ||
20887 | The input types are | |
20888 | ||
20889 | @table @code | |
20890 | @findex pre-prompt | |
20891 | @findex prompt | |
20892 | @findex post-prompt | |
20893 | @item prompt | |
20894 | When @value{GDBN} is prompting for a command (the main @value{GDBN} prompt). | |
20895 | ||
20896 | @findex pre-commands | |
20897 | @findex commands | |
20898 | @findex post-commands | |
20899 | @item commands | |
20900 | When @value{GDBN} prompts for a set of commands, like in the @code{commands} | |
20901 | command. The annotations are repeated for each command which is input. | |
20902 | ||
20903 | @findex pre-overload-choice | |
20904 | @findex overload-choice | |
20905 | @findex post-overload-choice | |
20906 | @item overload-choice | |
20907 | When @value{GDBN} wants the user to select between various overloaded functions. | |
20908 | ||
20909 | @findex pre-query | |
20910 | @findex query | |
20911 | @findex post-query | |
20912 | @item query | |
20913 | When @value{GDBN} wants the user to confirm a potentially dangerous operation. | |
20914 | ||
20915 | @findex pre-prompt-for-continue | |
20916 | @findex prompt-for-continue | |
20917 | @findex post-prompt-for-continue | |
20918 | @item prompt-for-continue | |
20919 | When @value{GDBN} is asking the user to press return to continue. Note: Don't | |
20920 | expect this to work well; instead use @code{set height 0} to disable | |
20921 | prompting. This is because the counting of lines is buggy in the | |
20922 | presence of annotations. | |
20923 | @end table | |
20924 | ||
20925 | @node Errors | |
20926 | @section Errors | |
20927 | @cindex annotations for errors, warnings and interrupts | |
20928 | ||
20929 | @findex quit | |
20930 | @smallexample | |
20931 | ^Z^Zquit | |
20932 | @end smallexample | |
20933 | ||
20934 | This annotation occurs right before @value{GDBN} responds to an interrupt. | |
20935 | ||
20936 | @findex error | |
20937 | @smallexample | |
20938 | ^Z^Zerror | |
20939 | @end smallexample | |
20940 | ||
20941 | This annotation occurs right before @value{GDBN} responds to an error. | |
20942 | ||
20943 | Quit and error annotations indicate that any annotations which @value{GDBN} was | |
20944 | in the middle of may end abruptly. For example, if a | |
20945 | @code{value-history-begin} annotation is followed by a @code{error}, one | |
20946 | cannot expect to receive the matching @code{value-history-end}. One | |
20947 | cannot expect not to receive it either, however; an error annotation | |
20948 | does not necessarily mean that @value{GDBN} is immediately returning all the way | |
20949 | to the top level. | |
20950 | ||
20951 | @findex error-begin | |
20952 | A quit or error annotation may be preceded by | |
20953 | ||
20954 | @smallexample | |
20955 | ^Z^Zerror-begin | |
20956 | @end smallexample | |
20957 | ||
20958 | Any output between that and the quit or error annotation is the error | |
20959 | message. | |
20960 | ||
20961 | Warning messages are not yet annotated. | |
20962 | @c If we want to change that, need to fix warning(), type_error(), | |
20963 | @c range_error(), and possibly other places. | |
20964 | ||
922fbb7b AC |
20965 | @node Invalidation |
20966 | @section Invalidation Notices | |
20967 | ||
20968 | @cindex annotations for invalidation messages | |
20969 | The following annotations say that certain pieces of state may have | |
20970 | changed. | |
20971 | ||
20972 | @table @code | |
20973 | @findex frames-invalid | |
20974 | @item ^Z^Zframes-invalid | |
20975 | ||
20976 | The frames (for example, output from the @code{backtrace} command) may | |
20977 | have changed. | |
20978 | ||
20979 | @findex breakpoints-invalid | |
20980 | @item ^Z^Zbreakpoints-invalid | |
20981 | ||
20982 | The breakpoints may have changed. For example, the user just added or | |
20983 | deleted a breakpoint. | |
20984 | @end table | |
20985 | ||
20986 | @node Annotations for Running | |
20987 | @section Running the Program | |
20988 | @cindex annotations for running programs | |
20989 | ||
20990 | @findex starting | |
20991 | @findex stopping | |
20992 | When the program starts executing due to a @value{GDBN} command such as | |
b383017d | 20993 | @code{step} or @code{continue}, |
922fbb7b AC |
20994 | |
20995 | @smallexample | |
20996 | ^Z^Zstarting | |
20997 | @end smallexample | |
20998 | ||
b383017d | 20999 | is output. When the program stops, |
922fbb7b AC |
21000 | |
21001 | @smallexample | |
21002 | ^Z^Zstopped | |
21003 | @end smallexample | |
21004 | ||
21005 | is output. Before the @code{stopped} annotation, a variety of | |
21006 | annotations describe how the program stopped. | |
21007 | ||
21008 | @table @code | |
21009 | @findex exited | |
21010 | @item ^Z^Zexited @var{exit-status} | |
21011 | The program exited, and @var{exit-status} is the exit status (zero for | |
21012 | successful exit, otherwise nonzero). | |
21013 | ||
21014 | @findex signalled | |
21015 | @findex signal-name | |
21016 | @findex signal-name-end | |
21017 | @findex signal-string | |
21018 | @findex signal-string-end | |
21019 | @item ^Z^Zsignalled | |
21020 | The program exited with a signal. After the @code{^Z^Zsignalled}, the | |
21021 | annotation continues: | |
21022 | ||
21023 | @smallexample | |
21024 | @var{intro-text} | |
21025 | ^Z^Zsignal-name | |
21026 | @var{name} | |
21027 | ^Z^Zsignal-name-end | |
21028 | @var{middle-text} | |
21029 | ^Z^Zsignal-string | |
21030 | @var{string} | |
21031 | ^Z^Zsignal-string-end | |
21032 | @var{end-text} | |
21033 | @end smallexample | |
21034 | ||
21035 | @noindent | |
21036 | where @var{name} is the name of the signal, such as @code{SIGILL} or | |
21037 | @code{SIGSEGV}, and @var{string} is the explanation of the signal, such | |
21038 | as @code{Illegal Instruction} or @code{Segmentation fault}. | |
21039 | @var{intro-text}, @var{middle-text}, and @var{end-text} are for the | |
21040 | user's benefit and have no particular format. | |
21041 | ||
21042 | @findex signal | |
21043 | @item ^Z^Zsignal | |
21044 | The syntax of this annotation is just like @code{signalled}, but @value{GDBN} is | |
21045 | just saying that the program received the signal, not that it was | |
21046 | terminated with it. | |
21047 | ||
21048 | @findex breakpoint | |
21049 | @item ^Z^Zbreakpoint @var{number} | |
21050 | The program hit breakpoint number @var{number}. | |
21051 | ||
21052 | @findex watchpoint | |
21053 | @item ^Z^Zwatchpoint @var{number} | |
21054 | The program hit watchpoint number @var{number}. | |
21055 | @end table | |
21056 | ||
21057 | @node Source Annotations | |
21058 | @section Displaying Source | |
21059 | @cindex annotations for source display | |
21060 | ||
21061 | @findex source | |
21062 | The following annotation is used instead of displaying source code: | |
21063 | ||
21064 | @smallexample | |
21065 | ^Z^Zsource @var{filename}:@var{line}:@var{character}:@var{middle}:@var{addr} | |
21066 | @end smallexample | |
21067 | ||
21068 | where @var{filename} is an absolute file name indicating which source | |
21069 | file, @var{line} is the line number within that file (where 1 is the | |
21070 | first line in the file), @var{character} is the character position | |
21071 | within the file (where 0 is the first character in the file) (for most | |
21072 | debug formats this will necessarily point to the beginning of a line), | |
21073 | @var{middle} is @samp{middle} if @var{addr} is in the middle of the | |
21074 | line, or @samp{beg} if @var{addr} is at the beginning of the line, and | |
21075 | @var{addr} is the address in the target program associated with the | |
21076 | source which is being displayed. @var{addr} is in the form @samp{0x} | |
21077 | followed by one or more lowercase hex digits (note that this does not | |
21078 | depend on the language). | |
21079 | ||
8e04817f AC |
21080 | @node GDB Bugs |
21081 | @chapter Reporting Bugs in @value{GDBN} | |
21082 | @cindex bugs in @value{GDBN} | |
21083 | @cindex reporting bugs in @value{GDBN} | |
c906108c | 21084 | |
8e04817f | 21085 | Your bug reports play an essential role in making @value{GDBN} reliable. |
c906108c | 21086 | |
8e04817f AC |
21087 | Reporting a bug may help you by bringing a solution to your problem, or it |
21088 | may not. But in any case the principal function of a bug report is to help | |
21089 | the entire community by making the next version of @value{GDBN} work better. Bug | |
21090 | reports are your contribution to the maintenance of @value{GDBN}. | |
c906108c | 21091 | |
8e04817f AC |
21092 | In order for a bug report to serve its purpose, you must include the |
21093 | information that enables us to fix the bug. | |
c4555f82 SC |
21094 | |
21095 | @menu | |
8e04817f AC |
21096 | * Bug Criteria:: Have you found a bug? |
21097 | * Bug Reporting:: How to report bugs | |
c4555f82 SC |
21098 | @end menu |
21099 | ||
8e04817f AC |
21100 | @node Bug Criteria |
21101 | @section Have you found a bug? | |
21102 | @cindex bug criteria | |
c4555f82 | 21103 | |
8e04817f | 21104 | If you are not sure whether you have found a bug, here are some guidelines: |
c4555f82 SC |
21105 | |
21106 | @itemize @bullet | |
8e04817f AC |
21107 | @cindex fatal signal |
21108 | @cindex debugger crash | |
21109 | @cindex crash of debugger | |
c4555f82 | 21110 | @item |
8e04817f AC |
21111 | If the debugger gets a fatal signal, for any input whatever, that is a |
21112 | @value{GDBN} bug. Reliable debuggers never crash. | |
21113 | ||
21114 | @cindex error on valid input | |
21115 | @item | |
21116 | If @value{GDBN} produces an error message for valid input, that is a | |
21117 | bug. (Note that if you're cross debugging, the problem may also be | |
21118 | somewhere in the connection to the target.) | |
c4555f82 | 21119 | |
8e04817f | 21120 | @cindex invalid input |
c4555f82 | 21121 | @item |
8e04817f AC |
21122 | If @value{GDBN} does not produce an error message for invalid input, |
21123 | that is a bug. However, you should note that your idea of | |
21124 | ``invalid input'' might be our idea of ``an extension'' or ``support | |
21125 | for traditional practice''. | |
21126 | ||
21127 | @item | |
21128 | If you are an experienced user of debugging tools, your suggestions | |
21129 | for improvement of @value{GDBN} are welcome in any case. | |
c4555f82 SC |
21130 | @end itemize |
21131 | ||
8e04817f AC |
21132 | @node Bug Reporting |
21133 | @section How to report bugs | |
21134 | @cindex bug reports | |
21135 | @cindex @value{GDBN} bugs, reporting | |
21136 | ||
21137 | A number of companies and individuals offer support for @sc{gnu} products. | |
21138 | If you obtained @value{GDBN} from a support organization, we recommend you | |
21139 | contact that organization first. | |
21140 | ||
21141 | You can find contact information for many support companies and | |
21142 | individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs | |
21143 | distribution. | |
21144 | @c should add a web page ref... | |
21145 | ||
129188f6 AC |
21146 | In any event, we also recommend that you submit bug reports for |
21147 | @value{GDBN}. The prefered method is to submit them directly using | |
21148 | @uref{http://www.gnu.org/software/gdb/bugs/, @value{GDBN}'s Bugs web | |
21149 | page}. Alternatively, the @email{bug-gdb@@gnu.org, e-mail gateway} can | |
21150 | be used. | |
8e04817f AC |
21151 | |
21152 | @strong{Do not send bug reports to @samp{info-gdb}, or to | |
21153 | @samp{help-gdb}, or to any newsgroups.} Most users of @value{GDBN} do | |
21154 | not want to receive bug reports. Those that do have arranged to receive | |
21155 | @samp{bug-gdb}. | |
21156 | ||
21157 | The mailing list @samp{bug-gdb} has a newsgroup @samp{gnu.gdb.bug} which | |
21158 | serves as a repeater. The mailing list and the newsgroup carry exactly | |
21159 | the same messages. Often people think of posting bug reports to the | |
21160 | newsgroup instead of mailing them. This appears to work, but it has one | |
21161 | problem which can be crucial: a newsgroup posting often lacks a mail | |
21162 | path back to the sender. Thus, if we need to ask for more information, | |
21163 | we may be unable to reach you. For this reason, it is better to send | |
21164 | bug reports to the mailing list. | |
c4555f82 | 21165 | |
8e04817f AC |
21166 | The fundamental principle of reporting bugs usefully is this: |
21167 | @strong{report all the facts}. If you are not sure whether to state a | |
21168 | fact or leave it out, state it! | |
c4555f82 | 21169 | |
8e04817f AC |
21170 | Often people omit facts because they think they know what causes the |
21171 | problem and assume that some details do not matter. Thus, you might | |
21172 | assume that the name of the variable you use in an example does not matter. | |
21173 | Well, probably it does not, but one cannot be sure. Perhaps the bug is a | |
21174 | stray memory reference which happens to fetch from the location where that | |
21175 | name is stored in memory; perhaps, if the name were different, the contents | |
21176 | of that location would fool the debugger into doing the right thing despite | |
21177 | the bug. Play it safe and give a specific, complete example. That is the | |
21178 | easiest thing for you to do, and the most helpful. | |
c4555f82 | 21179 | |
8e04817f AC |
21180 | Keep in mind that the purpose of a bug report is to enable us to fix the |
21181 | bug. It may be that the bug has been reported previously, but neither | |
21182 | you nor we can know that unless your bug report is complete and | |
21183 | self-contained. | |
c4555f82 | 21184 | |
8e04817f AC |
21185 | Sometimes people give a few sketchy facts and ask, ``Does this ring a |
21186 | bell?'' Those bug reports are useless, and we urge everyone to | |
21187 | @emph{refuse to respond to them} except to chide the sender to report | |
21188 | bugs properly. | |
21189 | ||
21190 | To enable us to fix the bug, you should include all these things: | |
c4555f82 SC |
21191 | |
21192 | @itemize @bullet | |
21193 | @item | |
8e04817f AC |
21194 | The version of @value{GDBN}. @value{GDBN} announces it if you start |
21195 | with no arguments; you can also print it at any time using @code{show | |
21196 | version}. | |
c4555f82 | 21197 | |
8e04817f AC |
21198 | Without this, we will not know whether there is any point in looking for |
21199 | the bug in the current version of @value{GDBN}. | |
c4555f82 SC |
21200 | |
21201 | @item | |
8e04817f AC |
21202 | The type of machine you are using, and the operating system name and |
21203 | version number. | |
c4555f82 SC |
21204 | |
21205 | @item | |
8e04817f AC |
21206 | What compiler (and its version) was used to compile @value{GDBN}---e.g. |
21207 | ``@value{GCC}--2.8.1''. | |
c4555f82 SC |
21208 | |
21209 | @item | |
8e04817f AC |
21210 | What compiler (and its version) was used to compile the program you are |
21211 | debugging---e.g. ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP | |
21212 | C Compiler''. For GCC, you can say @code{gcc --version} to get this | |
21213 | information; for other compilers, see the documentation for those | |
21214 | compilers. | |
c4555f82 | 21215 | |
8e04817f AC |
21216 | @item |
21217 | The command arguments you gave the compiler to compile your example and | |
21218 | observe the bug. For example, did you use @samp{-O}? To guarantee | |
21219 | you will not omit something important, list them all. A copy of the | |
21220 | Makefile (or the output from make) is sufficient. | |
c4555f82 | 21221 | |
8e04817f AC |
21222 | If we were to try to guess the arguments, we would probably guess wrong |
21223 | and then we might not encounter the bug. | |
c4555f82 | 21224 | |
8e04817f AC |
21225 | @item |
21226 | A complete input script, and all necessary source files, that will | |
21227 | reproduce the bug. | |
c4555f82 | 21228 | |
8e04817f AC |
21229 | @item |
21230 | A description of what behavior you observe that you believe is | |
21231 | incorrect. For example, ``It gets a fatal signal.'' | |
c4555f82 | 21232 | |
8e04817f AC |
21233 | Of course, if the bug is that @value{GDBN} gets a fatal signal, then we |
21234 | will certainly notice it. But if the bug is incorrect output, we might | |
21235 | not notice unless it is glaringly wrong. You might as well not give us | |
21236 | a chance to make a mistake. | |
c4555f82 | 21237 | |
8e04817f AC |
21238 | Even if the problem you experience is a fatal signal, you should still |
21239 | say so explicitly. Suppose something strange is going on, such as, your | |
21240 | copy of @value{GDBN} is out of synch, or you have encountered a bug in | |
21241 | the C library on your system. (This has happened!) Your copy might | |
21242 | crash and ours would not. If you told us to expect a crash, then when | |
21243 | ours fails to crash, we would know that the bug was not happening for | |
21244 | us. If you had not told us to expect a crash, then we would not be able | |
21245 | to draw any conclusion from our observations. | |
c4555f82 | 21246 | |
e0c07bf0 MC |
21247 | @pindex script |
21248 | @cindex recording a session script | |
21249 | To collect all this information, you can use a session recording program | |
21250 | such as @command{script}, which is available on many Unix systems. | |
21251 | Just run your @value{GDBN} session inside @command{script} and then | |
21252 | include the @file{typescript} file with your bug report. | |
21253 | ||
21254 | Another way to record a @value{GDBN} session is to run @value{GDBN} | |
21255 | inside Emacs and then save the entire buffer to a file. | |
21256 | ||
8e04817f AC |
21257 | @item |
21258 | If you wish to suggest changes to the @value{GDBN} source, send us context | |
21259 | diffs. If you even discuss something in the @value{GDBN} source, refer to | |
21260 | it by context, not by line number. | |
c4555f82 | 21261 | |
8e04817f AC |
21262 | The line numbers in our development sources will not match those in your |
21263 | sources. Your line numbers would convey no useful information to us. | |
c4555f82 | 21264 | |
8e04817f | 21265 | @end itemize |
c4555f82 | 21266 | |
8e04817f | 21267 | Here are some things that are not necessary: |
c4555f82 | 21268 | |
8e04817f AC |
21269 | @itemize @bullet |
21270 | @item | |
21271 | A description of the envelope of the bug. | |
c4555f82 | 21272 | |
8e04817f AC |
21273 | Often people who encounter a bug spend a lot of time investigating |
21274 | which changes to the input file will make the bug go away and which | |
21275 | changes will not affect it. | |
c4555f82 | 21276 | |
8e04817f AC |
21277 | This is often time consuming and not very useful, because the way we |
21278 | will find the bug is by running a single example under the debugger | |
21279 | with breakpoints, not by pure deduction from a series of examples. | |
21280 | We recommend that you save your time for something else. | |
c4555f82 | 21281 | |
8e04817f AC |
21282 | Of course, if you can find a simpler example to report @emph{instead} |
21283 | of the original one, that is a convenience for us. Errors in the | |
21284 | output will be easier to spot, running under the debugger will take | |
21285 | less time, and so on. | |
c4555f82 | 21286 | |
8e04817f AC |
21287 | However, simplification is not vital; if you do not want to do this, |
21288 | report the bug anyway and send us the entire test case you used. | |
c4555f82 | 21289 | |
8e04817f AC |
21290 | @item |
21291 | A patch for the bug. | |
c4555f82 | 21292 | |
8e04817f AC |
21293 | A patch for the bug does help us if it is a good one. But do not omit |
21294 | the necessary information, such as the test case, on the assumption that | |
21295 | a patch is all we need. We might see problems with your patch and decide | |
21296 | to fix the problem another way, or we might not understand it at all. | |
c4555f82 | 21297 | |
8e04817f AC |
21298 | Sometimes with a program as complicated as @value{GDBN} it is very hard to |
21299 | construct an example that will make the program follow a certain path | |
21300 | through the code. If you do not send us the example, we will not be able | |
21301 | to construct one, so we will not be able to verify that the bug is fixed. | |
c4555f82 | 21302 | |
8e04817f AC |
21303 | And if we cannot understand what bug you are trying to fix, or why your |
21304 | patch should be an improvement, we will not install it. A test case will | |
21305 | help us to understand. | |
c4555f82 | 21306 | |
8e04817f AC |
21307 | @item |
21308 | A guess about what the bug is or what it depends on. | |
c4555f82 | 21309 | |
8e04817f AC |
21310 | Such guesses are usually wrong. Even we cannot guess right about such |
21311 | things without first using the debugger to find the facts. | |
21312 | @end itemize | |
c4555f82 | 21313 | |
8e04817f AC |
21314 | @c The readline documentation is distributed with the readline code |
21315 | @c and consists of the two following files: | |
21316 | @c rluser.texinfo | |
21317 | @c inc-hist.texinfo | |
21318 | @c Use -I with makeinfo to point to the appropriate directory, | |
21319 | @c environment var TEXINPUTS with TeX. | |
21320 | @include rluser.texinfo | |
21321 | @include inc-hist.texinfo | |
c4555f82 | 21322 | |
c4555f82 | 21323 | |
8e04817f AC |
21324 | @node Formatting Documentation |
21325 | @appendix Formatting Documentation | |
c4555f82 | 21326 | |
8e04817f AC |
21327 | @cindex @value{GDBN} reference card |
21328 | @cindex reference card | |
21329 | The @value{GDBN} 4 release includes an already-formatted reference card, ready | |
21330 | for printing with PostScript or Ghostscript, in the @file{gdb} | |
21331 | subdirectory of the main source directory@footnote{In | |
21332 | @file{gdb-@value{GDBVN}/gdb/refcard.ps} of the version @value{GDBVN} | |
21333 | release.}. If you can use PostScript or Ghostscript with your printer, | |
21334 | you can print the reference card immediately with @file{refcard.ps}. | |
c4555f82 | 21335 | |
8e04817f AC |
21336 | The release also includes the source for the reference card. You |
21337 | can format it, using @TeX{}, by typing: | |
c4555f82 | 21338 | |
474c8240 | 21339 | @smallexample |
8e04817f | 21340 | make refcard.dvi |
474c8240 | 21341 | @end smallexample |
c4555f82 | 21342 | |
8e04817f AC |
21343 | The @value{GDBN} reference card is designed to print in @dfn{landscape} |
21344 | mode on US ``letter'' size paper; | |
21345 | that is, on a sheet 11 inches wide by 8.5 inches | |
21346 | high. You will need to specify this form of printing as an option to | |
21347 | your @sc{dvi} output program. | |
c4555f82 | 21348 | |
8e04817f | 21349 | @cindex documentation |
c4555f82 | 21350 | |
8e04817f AC |
21351 | All the documentation for @value{GDBN} comes as part of the machine-readable |
21352 | distribution. The documentation is written in Texinfo format, which is | |
21353 | a documentation system that uses a single source file to produce both | |
21354 | on-line information and a printed manual. You can use one of the Info | |
21355 | formatting commands to create the on-line version of the documentation | |
21356 | and @TeX{} (or @code{texi2roff}) to typeset the printed version. | |
c4555f82 | 21357 | |
8e04817f AC |
21358 | @value{GDBN} includes an already formatted copy of the on-line Info |
21359 | version of this manual in the @file{gdb} subdirectory. The main Info | |
21360 | file is @file{gdb-@value{GDBVN}/gdb/gdb.info}, and it refers to | |
21361 | subordinate files matching @samp{gdb.info*} in the same directory. If | |
21362 | necessary, you can print out these files, or read them with any editor; | |
21363 | but they are easier to read using the @code{info} subsystem in @sc{gnu} | |
21364 | Emacs or the standalone @code{info} program, available as part of the | |
21365 | @sc{gnu} Texinfo distribution. | |
c4555f82 | 21366 | |
8e04817f AC |
21367 | If you want to format these Info files yourself, you need one of the |
21368 | Info formatting programs, such as @code{texinfo-format-buffer} or | |
21369 | @code{makeinfo}. | |
c4555f82 | 21370 | |
8e04817f AC |
21371 | If you have @code{makeinfo} installed, and are in the top level |
21372 | @value{GDBN} source directory (@file{gdb-@value{GDBVN}}, in the case of | |
21373 | version @value{GDBVN}), you can make the Info file by typing: | |
c4555f82 | 21374 | |
474c8240 | 21375 | @smallexample |
8e04817f AC |
21376 | cd gdb |
21377 | make gdb.info | |
474c8240 | 21378 | @end smallexample |
c4555f82 | 21379 | |
8e04817f AC |
21380 | If you want to typeset and print copies of this manual, you need @TeX{}, |
21381 | a program to print its @sc{dvi} output files, and @file{texinfo.tex}, the | |
21382 | Texinfo definitions file. | |
c4555f82 | 21383 | |
8e04817f AC |
21384 | @TeX{} is a typesetting program; it does not print files directly, but |
21385 | produces output files called @sc{dvi} files. To print a typeset | |
21386 | document, you need a program to print @sc{dvi} files. If your system | |
21387 | has @TeX{} installed, chances are it has such a program. The precise | |
21388 | command to use depends on your system; @kbd{lpr -d} is common; another | |
21389 | (for PostScript devices) is @kbd{dvips}. The @sc{dvi} print command may | |
21390 | require a file name without any extension or a @samp{.dvi} extension. | |
c4555f82 | 21391 | |
8e04817f AC |
21392 | @TeX{} also requires a macro definitions file called |
21393 | @file{texinfo.tex}. This file tells @TeX{} how to typeset a document | |
21394 | written in Texinfo format. On its own, @TeX{} cannot either read or | |
21395 | typeset a Texinfo file. @file{texinfo.tex} is distributed with GDB | |
21396 | and is located in the @file{gdb-@var{version-number}/texinfo} | |
21397 | directory. | |
c4555f82 | 21398 | |
8e04817f AC |
21399 | If you have @TeX{} and a @sc{dvi} printer program installed, you can |
21400 | typeset and print this manual. First switch to the the @file{gdb} | |
21401 | subdirectory of the main source directory (for example, to | |
21402 | @file{gdb-@value{GDBVN}/gdb}) and type: | |
c4555f82 | 21403 | |
474c8240 | 21404 | @smallexample |
8e04817f | 21405 | make gdb.dvi |
474c8240 | 21406 | @end smallexample |
c4555f82 | 21407 | |
8e04817f | 21408 | Then give @file{gdb.dvi} to your @sc{dvi} printing program. |
c4555f82 | 21409 | |
8e04817f AC |
21410 | @node Installing GDB |
21411 | @appendix Installing @value{GDBN} | |
21412 | @cindex configuring @value{GDBN} | |
21413 | @cindex installation | |
94e91d6d | 21414 | @cindex configuring @value{GDBN}, and source tree subdirectories |
c4555f82 | 21415 | |
8e04817f AC |
21416 | @value{GDBN} comes with a @code{configure} script that automates the process |
21417 | of preparing @value{GDBN} for installation; you can then use @code{make} to | |
21418 | build the @code{gdb} program. | |
21419 | @iftex | |
21420 | @c irrelevant in info file; it's as current as the code it lives with. | |
21421 | @footnote{If you have a more recent version of @value{GDBN} than @value{GDBVN}, | |
21422 | look at the @file{README} file in the sources; we may have improved the | |
21423 | installation procedures since publishing this manual.} | |
21424 | @end iftex | |
c4555f82 | 21425 | |
8e04817f AC |
21426 | The @value{GDBN} distribution includes all the source code you need for |
21427 | @value{GDBN} in a single directory, whose name is usually composed by | |
21428 | appending the version number to @samp{gdb}. | |
c4555f82 | 21429 | |
8e04817f AC |
21430 | For example, the @value{GDBN} version @value{GDBVN} distribution is in the |
21431 | @file{gdb-@value{GDBVN}} directory. That directory contains: | |
c4555f82 | 21432 | |
8e04817f AC |
21433 | @table @code |
21434 | @item gdb-@value{GDBVN}/configure @r{(and supporting files)} | |
21435 | script for configuring @value{GDBN} and all its supporting libraries | |
c4555f82 | 21436 | |
8e04817f AC |
21437 | @item gdb-@value{GDBVN}/gdb |
21438 | the source specific to @value{GDBN} itself | |
c4555f82 | 21439 | |
8e04817f AC |
21440 | @item gdb-@value{GDBVN}/bfd |
21441 | source for the Binary File Descriptor library | |
c906108c | 21442 | |
8e04817f AC |
21443 | @item gdb-@value{GDBVN}/include |
21444 | @sc{gnu} include files | |
c906108c | 21445 | |
8e04817f AC |
21446 | @item gdb-@value{GDBVN}/libiberty |
21447 | source for the @samp{-liberty} free software library | |
c906108c | 21448 | |
8e04817f AC |
21449 | @item gdb-@value{GDBVN}/opcodes |
21450 | source for the library of opcode tables and disassemblers | |
c906108c | 21451 | |
8e04817f AC |
21452 | @item gdb-@value{GDBVN}/readline |
21453 | source for the @sc{gnu} command-line interface | |
c906108c | 21454 | |
8e04817f AC |
21455 | @item gdb-@value{GDBVN}/glob |
21456 | source for the @sc{gnu} filename pattern-matching subroutine | |
c906108c | 21457 | |
8e04817f AC |
21458 | @item gdb-@value{GDBVN}/mmalloc |
21459 | source for the @sc{gnu} memory-mapped malloc package | |
21460 | @end table | |
c906108c | 21461 | |
8e04817f AC |
21462 | The simplest way to configure and build @value{GDBN} is to run @code{configure} |
21463 | from the @file{gdb-@var{version-number}} source directory, which in | |
21464 | this example is the @file{gdb-@value{GDBVN}} directory. | |
c906108c | 21465 | |
8e04817f AC |
21466 | First switch to the @file{gdb-@var{version-number}} source directory |
21467 | if you are not already in it; then run @code{configure}. Pass the | |
21468 | identifier for the platform on which @value{GDBN} will run as an | |
21469 | argument. | |
c906108c | 21470 | |
8e04817f | 21471 | For example: |
c906108c | 21472 | |
474c8240 | 21473 | @smallexample |
8e04817f AC |
21474 | cd gdb-@value{GDBVN} |
21475 | ./configure @var{host} | |
21476 | make | |
474c8240 | 21477 | @end smallexample |
c906108c | 21478 | |
8e04817f AC |
21479 | @noindent |
21480 | where @var{host} is an identifier such as @samp{sun4} or | |
21481 | @samp{decstation}, that identifies the platform where @value{GDBN} will run. | |
21482 | (You can often leave off @var{host}; @code{configure} tries to guess the | |
21483 | correct value by examining your system.) | |
c906108c | 21484 | |
8e04817f AC |
21485 | Running @samp{configure @var{host}} and then running @code{make} builds the |
21486 | @file{bfd}, @file{readline}, @file{mmalloc}, and @file{libiberty} | |
21487 | libraries, then @code{gdb} itself. The configured source files, and the | |
21488 | binaries, are left in the corresponding source directories. | |
c906108c | 21489 | |
8e04817f AC |
21490 | @need 750 |
21491 | @code{configure} is a Bourne-shell (@code{/bin/sh}) script; if your | |
21492 | system does not recognize this automatically when you run a different | |
21493 | shell, you may need to run @code{sh} on it explicitly: | |
c906108c | 21494 | |
474c8240 | 21495 | @smallexample |
8e04817f | 21496 | sh configure @var{host} |
474c8240 | 21497 | @end smallexample |
c906108c | 21498 | |
8e04817f AC |
21499 | If you run @code{configure} from a directory that contains source |
21500 | directories for multiple libraries or programs, such as the | |
21501 | @file{gdb-@value{GDBVN}} source directory for version @value{GDBVN}, @code{configure} | |
21502 | creates configuration files for every directory level underneath (unless | |
21503 | you tell it not to, with the @samp{--norecursion} option). | |
21504 | ||
94e91d6d MC |
21505 | You should run the @code{configure} script from the top directory in the |
21506 | source tree, the @file{gdb-@var{version-number}} directory. If you run | |
21507 | @code{configure} from one of the subdirectories, you will configure only | |
21508 | that subdirectory. That is usually not what you want. In particular, | |
21509 | if you run the first @code{configure} from the @file{gdb} subdirectory | |
21510 | of the @file{gdb-@var{version-number}} directory, you will omit the | |
21511 | configuration of @file{bfd}, @file{readline}, and other sibling | |
21512 | directories of the @file{gdb} subdirectory. This leads to build errors | |
21513 | about missing include files such as @file{bfd/bfd.h}. | |
c906108c | 21514 | |
8e04817f AC |
21515 | You can install @code{@value{GDBP}} anywhere; it has no hardwired paths. |
21516 | However, you should make sure that the shell on your path (named by | |
21517 | the @samp{SHELL} environment variable) is publicly readable. Remember | |
21518 | that @value{GDBN} uses the shell to start your program---some systems refuse to | |
21519 | let @value{GDBN} debug child processes whose programs are not readable. | |
c906108c | 21520 | |
8e04817f AC |
21521 | @menu |
21522 | * Separate Objdir:: Compiling @value{GDBN} in another directory | |
21523 | * Config Names:: Specifying names for hosts and targets | |
21524 | * Configure Options:: Summary of options for configure | |
21525 | @end menu | |
c906108c | 21526 | |
8e04817f AC |
21527 | @node Separate Objdir |
21528 | @section Compiling @value{GDBN} in another directory | |
c906108c | 21529 | |
8e04817f AC |
21530 | If you want to run @value{GDBN} versions for several host or target machines, |
21531 | you need a different @code{gdb} compiled for each combination of | |
21532 | host and target. @code{configure} is designed to make this easy by | |
21533 | allowing you to generate each configuration in a separate subdirectory, | |
21534 | rather than in the source directory. If your @code{make} program | |
21535 | handles the @samp{VPATH} feature (@sc{gnu} @code{make} does), running | |
21536 | @code{make} in each of these directories builds the @code{gdb} | |
21537 | program specified there. | |
c906108c | 21538 | |
8e04817f AC |
21539 | To build @code{gdb} in a separate directory, run @code{configure} |
21540 | with the @samp{--srcdir} option to specify where to find the source. | |
21541 | (You also need to specify a path to find @code{configure} | |
21542 | itself from your working directory. If the path to @code{configure} | |
21543 | would be the same as the argument to @samp{--srcdir}, you can leave out | |
21544 | the @samp{--srcdir} option; it is assumed.) | |
c906108c | 21545 | |
8e04817f AC |
21546 | For example, with version @value{GDBVN}, you can build @value{GDBN} in a |
21547 | separate directory for a Sun 4 like this: | |
c906108c | 21548 | |
474c8240 | 21549 | @smallexample |
8e04817f AC |
21550 | @group |
21551 | cd gdb-@value{GDBVN} | |
21552 | mkdir ../gdb-sun4 | |
21553 | cd ../gdb-sun4 | |
21554 | ../gdb-@value{GDBVN}/configure sun4 | |
21555 | make | |
21556 | @end group | |
474c8240 | 21557 | @end smallexample |
c906108c | 21558 | |
8e04817f AC |
21559 | When @code{configure} builds a configuration using a remote source |
21560 | directory, it creates a tree for the binaries with the same structure | |
21561 | (and using the same names) as the tree under the source directory. In | |
21562 | the example, you'd find the Sun 4 library @file{libiberty.a} in the | |
21563 | directory @file{gdb-sun4/libiberty}, and @value{GDBN} itself in | |
21564 | @file{gdb-sun4/gdb}. | |
c906108c | 21565 | |
94e91d6d MC |
21566 | Make sure that your path to the @file{configure} script has just one |
21567 | instance of @file{gdb} in it. If your path to @file{configure} looks | |
21568 | like @file{../gdb-@value{GDBVN}/gdb/configure}, you are configuring only | |
21569 | one subdirectory of @value{GDBN}, not the whole package. This leads to | |
21570 | build errors about missing include files such as @file{bfd/bfd.h}. | |
21571 | ||
8e04817f AC |
21572 | One popular reason to build several @value{GDBN} configurations in separate |
21573 | directories is to configure @value{GDBN} for cross-compiling (where | |
21574 | @value{GDBN} runs on one machine---the @dfn{host}---while debugging | |
21575 | programs that run on another machine---the @dfn{target}). | |
21576 | You specify a cross-debugging target by | |
21577 | giving the @samp{--target=@var{target}} option to @code{configure}. | |
c906108c | 21578 | |
8e04817f AC |
21579 | When you run @code{make} to build a program or library, you must run |
21580 | it in a configured directory---whatever directory you were in when you | |
21581 | called @code{configure} (or one of its subdirectories). | |
c906108c | 21582 | |
8e04817f AC |
21583 | The @code{Makefile} that @code{configure} generates in each source |
21584 | directory also runs recursively. If you type @code{make} in a source | |
21585 | directory such as @file{gdb-@value{GDBVN}} (or in a separate configured | |
21586 | directory configured with @samp{--srcdir=@var{dirname}/gdb-@value{GDBVN}}), you | |
21587 | will build all the required libraries, and then build GDB. | |
c906108c | 21588 | |
8e04817f AC |
21589 | When you have multiple hosts or targets configured in separate |
21590 | directories, you can run @code{make} on them in parallel (for example, | |
21591 | if they are NFS-mounted on each of the hosts); they will not interfere | |
21592 | with each other. | |
c906108c | 21593 | |
8e04817f AC |
21594 | @node Config Names |
21595 | @section Specifying names for hosts and targets | |
c906108c | 21596 | |
8e04817f AC |
21597 | The specifications used for hosts and targets in the @code{configure} |
21598 | script are based on a three-part naming scheme, but some short predefined | |
21599 | aliases are also supported. The full naming scheme encodes three pieces | |
21600 | of information in the following pattern: | |
c906108c | 21601 | |
474c8240 | 21602 | @smallexample |
8e04817f | 21603 | @var{architecture}-@var{vendor}-@var{os} |
474c8240 | 21604 | @end smallexample |
c906108c | 21605 | |
8e04817f AC |
21606 | For example, you can use the alias @code{sun4} as a @var{host} argument, |
21607 | or as the value for @var{target} in a @code{--target=@var{target}} | |
21608 | option. The equivalent full name is @samp{sparc-sun-sunos4}. | |
c906108c | 21609 | |
8e04817f AC |
21610 | The @code{configure} script accompanying @value{GDBN} does not provide |
21611 | any query facility to list all supported host and target names or | |
21612 | aliases. @code{configure} calls the Bourne shell script | |
21613 | @code{config.sub} to map abbreviations to full names; you can read the | |
21614 | script, if you wish, or you can use it to test your guesses on | |
21615 | abbreviations---for example: | |
c906108c | 21616 | |
8e04817f AC |
21617 | @smallexample |
21618 | % sh config.sub i386-linux | |
21619 | i386-pc-linux-gnu | |
21620 | % sh config.sub alpha-linux | |
21621 | alpha-unknown-linux-gnu | |
21622 | % sh config.sub hp9k700 | |
21623 | hppa1.1-hp-hpux | |
21624 | % sh config.sub sun4 | |
21625 | sparc-sun-sunos4.1.1 | |
21626 | % sh config.sub sun3 | |
21627 | m68k-sun-sunos4.1.1 | |
21628 | % sh config.sub i986v | |
21629 | Invalid configuration `i986v': machine `i986v' not recognized | |
21630 | @end smallexample | |
c906108c | 21631 | |
8e04817f AC |
21632 | @noindent |
21633 | @code{config.sub} is also distributed in the @value{GDBN} source | |
21634 | directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}). | |
d700128c | 21635 | |
8e04817f AC |
21636 | @node Configure Options |
21637 | @section @code{configure} options | |
c906108c | 21638 | |
8e04817f AC |
21639 | Here is a summary of the @code{configure} options and arguments that |
21640 | are most often useful for building @value{GDBN}. @code{configure} also has | |
21641 | several other options not listed here. @inforef{What Configure | |
21642 | Does,,configure.info}, for a full explanation of @code{configure}. | |
c906108c | 21643 | |
474c8240 | 21644 | @smallexample |
8e04817f AC |
21645 | configure @r{[}--help@r{]} |
21646 | @r{[}--prefix=@var{dir}@r{]} | |
21647 | @r{[}--exec-prefix=@var{dir}@r{]} | |
21648 | @r{[}--srcdir=@var{dirname}@r{]} | |
21649 | @r{[}--norecursion@r{]} @r{[}--rm@r{]} | |
21650 | @r{[}--target=@var{target}@r{]} | |
21651 | @var{host} | |
474c8240 | 21652 | @end smallexample |
c906108c | 21653 | |
8e04817f AC |
21654 | @noindent |
21655 | You may introduce options with a single @samp{-} rather than | |
21656 | @samp{--} if you prefer; but you may abbreviate option names if you use | |
21657 | @samp{--}. | |
c906108c | 21658 | |
8e04817f AC |
21659 | @table @code |
21660 | @item --help | |
21661 | Display a quick summary of how to invoke @code{configure}. | |
c906108c | 21662 | |
8e04817f AC |
21663 | @item --prefix=@var{dir} |
21664 | Configure the source to install programs and files under directory | |
21665 | @file{@var{dir}}. | |
c906108c | 21666 | |
8e04817f AC |
21667 | @item --exec-prefix=@var{dir} |
21668 | Configure the source to install programs under directory | |
21669 | @file{@var{dir}}. | |
c906108c | 21670 | |
8e04817f AC |
21671 | @c avoid splitting the warning from the explanation: |
21672 | @need 2000 | |
21673 | @item --srcdir=@var{dirname} | |
21674 | @strong{Warning: using this option requires @sc{gnu} @code{make}, or another | |
21675 | @code{make} that implements the @code{VPATH} feature.}@* | |
21676 | Use this option to make configurations in directories separate from the | |
21677 | @value{GDBN} source directories. Among other things, you can use this to | |
21678 | build (or maintain) several configurations simultaneously, in separate | |
21679 | directories. @code{configure} writes configuration specific files in | |
21680 | the current directory, but arranges for them to use the source in the | |
21681 | directory @var{dirname}. @code{configure} creates directories under | |
21682 | the working directory in parallel to the source directories below | |
21683 | @var{dirname}. | |
c906108c | 21684 | |
8e04817f AC |
21685 | @item --norecursion |
21686 | Configure only the directory level where @code{configure} is executed; do not | |
21687 | propagate configuration to subdirectories. | |
c906108c | 21688 | |
8e04817f AC |
21689 | @item --target=@var{target} |
21690 | Configure @value{GDBN} for cross-debugging programs running on the specified | |
21691 | @var{target}. Without this option, @value{GDBN} is configured to debug | |
21692 | programs that run on the same machine (@var{host}) as @value{GDBN} itself. | |
c906108c | 21693 | |
8e04817f | 21694 | There is no convenient way to generate a list of all available targets. |
c906108c | 21695 | |
8e04817f AC |
21696 | @item @var{host} @dots{} |
21697 | Configure @value{GDBN} to run on the specified @var{host}. | |
c906108c | 21698 | |
8e04817f AC |
21699 | There is no convenient way to generate a list of all available hosts. |
21700 | @end table | |
c906108c | 21701 | |
8e04817f AC |
21702 | There are many other options available as well, but they are generally |
21703 | needed for special purposes only. | |
c906108c | 21704 | |
8e04817f AC |
21705 | @node Maintenance Commands |
21706 | @appendix Maintenance Commands | |
21707 | @cindex maintenance commands | |
21708 | @cindex internal commands | |
c906108c | 21709 | |
8e04817f | 21710 | In addition to commands intended for @value{GDBN} users, @value{GDBN} |
09d4efe1 EZ |
21711 | includes a number of commands intended for @value{GDBN} developers, |
21712 | that are not documented elsewhere in this manual. These commands are | |
da316a69 EZ |
21713 | provided here for reference. (For commands that turn on debugging |
21714 | messages, see @ref{Debugging Output}.) | |
c906108c | 21715 | |
8e04817f | 21716 | @table @code |
09d4efe1 EZ |
21717 | @kindex maint agent |
21718 | @item maint agent @var{expression} | |
21719 | Translate the given @var{expression} into remote agent bytecodes. | |
21720 | This command is useful for debugging the Agent Expression mechanism | |
21721 | (@pxref{Agent Expressions}). | |
21722 | ||
8e04817f AC |
21723 | @kindex maint info breakpoints |
21724 | @item @anchor{maint info breakpoints}maint info breakpoints | |
21725 | Using the same format as @samp{info breakpoints}, display both the | |
21726 | breakpoints you've set explicitly, and those @value{GDBN} is using for | |
21727 | internal purposes. Internal breakpoints are shown with negative | |
21728 | breakpoint numbers. The type column identifies what kind of breakpoint | |
21729 | is shown: | |
c906108c | 21730 | |
8e04817f AC |
21731 | @table @code |
21732 | @item breakpoint | |
21733 | Normal, explicitly set breakpoint. | |
c906108c | 21734 | |
8e04817f AC |
21735 | @item watchpoint |
21736 | Normal, explicitly set watchpoint. | |
c906108c | 21737 | |
8e04817f AC |
21738 | @item longjmp |
21739 | Internal breakpoint, used to handle correctly stepping through | |
21740 | @code{longjmp} calls. | |
c906108c | 21741 | |
8e04817f AC |
21742 | @item longjmp resume |
21743 | Internal breakpoint at the target of a @code{longjmp}. | |
c906108c | 21744 | |
8e04817f AC |
21745 | @item until |
21746 | Temporary internal breakpoint used by the @value{GDBN} @code{until} command. | |
c906108c | 21747 | |
8e04817f AC |
21748 | @item finish |
21749 | Temporary internal breakpoint used by the @value{GDBN} @code{finish} command. | |
c906108c | 21750 | |
8e04817f AC |
21751 | @item shlib events |
21752 | Shared library events. | |
c906108c | 21753 | |
8e04817f | 21754 | @end table |
c906108c | 21755 | |
09d4efe1 EZ |
21756 | @kindex maint check-symtabs |
21757 | @item maint check-symtabs | |
21758 | Check the consistency of psymtabs and symtabs. | |
21759 | ||
21760 | @kindex maint cplus first_component | |
21761 | @item maint cplus first_component @var{name} | |
21762 | Print the first C@t{++} class/namespace component of @var{name}. | |
21763 | ||
21764 | @kindex maint cplus namespace | |
21765 | @item maint cplus namespace | |
21766 | Print the list of possible C@t{++} namespaces. | |
21767 | ||
21768 | @kindex maint demangle | |
21769 | @item maint demangle @var{name} | |
21770 | Demangle a C@t{++} or Objective-C manled @var{name}. | |
21771 | ||
21772 | @kindex maint deprecate | |
21773 | @kindex maint undeprecate | |
21774 | @cindex deprecated commands | |
21775 | @item maint deprecate @var{command} @r{[}@var{replacement}@r{]} | |
21776 | @itemx maint undeprecate @var{command} | |
21777 | Deprecate or undeprecate the named @var{command}. Deprecated commands | |
21778 | cause @value{GDBN} to issue a warning when you use them. The optional | |
21779 | argument @var{replacement} says which newer command should be used in | |
21780 | favor of the deprecated one; if it is given, @value{GDBN} will mention | |
21781 | the replacement as part of the warning. | |
21782 | ||
21783 | @kindex maint dump-me | |
21784 | @item maint dump-me | |
721c2651 | 21785 | @cindex @code{SIGQUIT} signal, dump core of @value{GDBN} |
09d4efe1 | 21786 | Cause a fatal signal in the debugger and force it to dump its core. |
721c2651 EZ |
21787 | This is supported only on systems which support aborting a program |
21788 | with the @code{SIGQUIT} signal. | |
09d4efe1 | 21789 | |
8d30a00d AC |
21790 | @kindex maint internal-error |
21791 | @kindex maint internal-warning | |
09d4efe1 EZ |
21792 | @item maint internal-error @r{[}@var{message-text}@r{]} |
21793 | @itemx maint internal-warning @r{[}@var{message-text}@r{]} | |
8d30a00d AC |
21794 | Cause @value{GDBN} to call the internal function @code{internal_error} |
21795 | or @code{internal_warning} and hence behave as though an internal error | |
21796 | or internal warning has been detected. In addition to reporting the | |
21797 | internal problem, these functions give the user the opportunity to | |
21798 | either quit @value{GDBN} or create a core file of the current | |
21799 | @value{GDBN} session. | |
21800 | ||
09d4efe1 EZ |
21801 | These commands take an optional parameter @var{message-text} that is |
21802 | used as the text of the error or warning message. | |
21803 | ||
21804 | Here's an example of using @code{indernal-error}: | |
21805 | ||
8d30a00d | 21806 | @smallexample |
f7dc1244 | 21807 | (@value{GDBP}) @kbd{maint internal-error testing, 1, 2} |
8d30a00d AC |
21808 | @dots{}/maint.c:121: internal-error: testing, 1, 2 |
21809 | A problem internal to GDB has been detected. Further | |
21810 | debugging may prove unreliable. | |
21811 | Quit this debugging session? (y or n) @kbd{n} | |
21812 | Create a core file? (y or n) @kbd{n} | |
f7dc1244 | 21813 | (@value{GDBP}) |
8d30a00d AC |
21814 | @end smallexample |
21815 | ||
09d4efe1 EZ |
21816 | @kindex maint packet |
21817 | @item maint packet @var{text} | |
21818 | If @value{GDBN} is talking to an inferior via the serial protocol, | |
21819 | then this command sends the string @var{text} to the inferior, and | |
21820 | displays the response packet. @value{GDBN} supplies the initial | |
21821 | @samp{$} character, the terminating @samp{#} character, and the | |
21822 | checksum. | |
21823 | ||
21824 | @kindex maint print architecture | |
21825 | @item maint print architecture @r{[}@var{file}@r{]} | |
21826 | Print the entire architecture configuration. The optional argument | |
21827 | @var{file} names the file where the output goes. | |
8d30a00d | 21828 | |
00905d52 AC |
21829 | @kindex maint print dummy-frames |
21830 | @item maint print dummy-frames | |
00905d52 AC |
21831 | Prints the contents of @value{GDBN}'s internal dummy-frame stack. |
21832 | ||
21833 | @smallexample | |
f7dc1244 | 21834 | (@value{GDBP}) @kbd{b add} |
00905d52 | 21835 | @dots{} |
f7dc1244 | 21836 | (@value{GDBP}) @kbd{print add(2,3)} |
00905d52 AC |
21837 | Breakpoint 2, add (a=2, b=3) at @dots{} |
21838 | 58 return (a + b); | |
21839 | The program being debugged stopped while in a function called from GDB. | |
21840 | @dots{} | |
f7dc1244 | 21841 | (@value{GDBP}) @kbd{maint print dummy-frames} |
00905d52 AC |
21842 | 0x1a57c80: pc=0x01014068 fp=0x0200bddc sp=0x0200bdd6 |
21843 | top=0x0200bdd4 id=@{stack=0x200bddc,code=0x101405c@} | |
21844 | call_lo=0x01014000 call_hi=0x01014001 | |
f7dc1244 | 21845 | (@value{GDBP}) |
00905d52 AC |
21846 | @end smallexample |
21847 | ||
21848 | Takes an optional file parameter. | |
21849 | ||
0680b120 AC |
21850 | @kindex maint print registers |
21851 | @kindex maint print raw-registers | |
21852 | @kindex maint print cooked-registers | |
617073a9 | 21853 | @kindex maint print register-groups |
09d4efe1 EZ |
21854 | @item maint print registers @r{[}@var{file}@r{]} |
21855 | @itemx maint print raw-registers @r{[}@var{file}@r{]} | |
21856 | @itemx maint print cooked-registers @r{[}@var{file}@r{]} | |
21857 | @itemx maint print register-groups @r{[}@var{file}@r{]} | |
0680b120 AC |
21858 | Print @value{GDBN}'s internal register data structures. |
21859 | ||
617073a9 AC |
21860 | The command @code{maint print raw-registers} includes the contents of |
21861 | the raw register cache; the command @code{maint print cooked-registers} | |
21862 | includes the (cooked) value of all registers; and the command | |
21863 | @code{maint print register-groups} includes the groups that each | |
21864 | register is a member of. @xref{Registers,, Registers, gdbint, | |
21865 | @value{GDBN} Internals}. | |
0680b120 | 21866 | |
09d4efe1 EZ |
21867 | These commands take an optional parameter, a file name to which to |
21868 | write the information. | |
0680b120 | 21869 | |
617073a9 | 21870 | @kindex maint print reggroups |
09d4efe1 EZ |
21871 | @item maint print reggroups @r{[}@var{file}@r{]} |
21872 | Print @value{GDBN}'s internal register group data structures. The | |
21873 | optional argument @var{file} tells to what file to write the | |
21874 | information. | |
617073a9 | 21875 | |
09d4efe1 | 21876 | The register groups info looks like this: |
617073a9 AC |
21877 | |
21878 | @smallexample | |
f7dc1244 | 21879 | (@value{GDBP}) @kbd{maint print reggroups} |
b383017d RM |
21880 | Group Type |
21881 | general user | |
21882 | float user | |
21883 | all user | |
21884 | vector user | |
21885 | system user | |
21886 | save internal | |
21887 | restore internal | |
617073a9 AC |
21888 | @end smallexample |
21889 | ||
09d4efe1 EZ |
21890 | @kindex flushregs |
21891 | @item flushregs | |
21892 | This command forces @value{GDBN} to flush its internal register cache. | |
21893 | ||
21894 | @kindex maint print objfiles | |
21895 | @cindex info for known object files | |
21896 | @item maint print objfiles | |
21897 | Print a dump of all known object files. For each object file, this | |
21898 | command prints its name, address in memory, and all of its psymtabs | |
21899 | and symtabs. | |
21900 | ||
21901 | @kindex maint print statistics | |
21902 | @cindex bcache statistics | |
21903 | @item maint print statistics | |
21904 | This command prints, for each object file in the program, various data | |
21905 | about that object file followed by the byte cache (@dfn{bcache}) | |
21906 | statistics for the object file. The objfile data includes the number | |
21907 | of minimal, partical, full, and stabs symbols, the number of types | |
21908 | defined by the objfile, the number of as yet unexpanded psym tables, | |
21909 | the number of line tables and string tables, and the amount of memory | |
21910 | used by the various tables. The bcache statistics include the counts, | |
21911 | sizes, and counts of duplicates of all and unique objects, max, | |
21912 | average, and median entry size, total memory used and its overhead and | |
21913 | savings, and various measures of the hash table size and chain | |
21914 | lengths. | |
21915 | ||
21916 | @kindex maint print type | |
21917 | @cindex type chain of a data type | |
21918 | @item maint print type @var{expr} | |
21919 | Print the type chain for a type specified by @var{expr}. The argument | |
21920 | can be either a type name or a symbol. If it is a symbol, the type of | |
21921 | that symbol is described. The type chain produced by this command is | |
21922 | a recursive definition of the data type as stored in @value{GDBN}'s | |
21923 | data structures, including its flags and contained types. | |
21924 | ||
21925 | @kindex maint set dwarf2 max-cache-age | |
21926 | @kindex maint show dwarf2 max-cache-age | |
21927 | @item maint set dwarf2 max-cache-age | |
21928 | @itemx maint show dwarf2 max-cache-age | |
21929 | Control the DWARF 2 compilation unit cache. | |
21930 | ||
21931 | @cindex DWARF 2 compilation units cache | |
21932 | In object files with inter-compilation-unit references, such as those | |
21933 | produced by the GCC option @samp{-feliminate-dwarf2-dups}, the DWARF 2 | |
21934 | reader needs to frequently refer to previously read compilation units. | |
21935 | This setting controls how long a compilation unit will remain in the | |
21936 | cache if it is not referenced. A higher limit means that cached | |
21937 | compilation units will be stored in memory longer, and more total | |
21938 | memory will be used. Setting it to zero disables caching, which will | |
21939 | slow down @value{GDBN} startup, but reduce memory consumption. | |
21940 | ||
e7ba9c65 DJ |
21941 | @kindex maint set profile |
21942 | @kindex maint show profile | |
21943 | @cindex profiling GDB | |
21944 | @item maint set profile | |
21945 | @itemx maint show profile | |
21946 | Control profiling of @value{GDBN}. | |
21947 | ||
21948 | Profiling will be disabled until you use the @samp{maint set profile} | |
21949 | command to enable it. When you enable profiling, the system will begin | |
21950 | collecting timing and execution count data; when you disable profiling or | |
21951 | exit @value{GDBN}, the results will be written to a log file. Remember that | |
21952 | if you use profiling, @value{GDBN} will overwrite the profiling log file | |
21953 | (often called @file{gmon.out}). If you have a record of important profiling | |
21954 | data in a @file{gmon.out} file, be sure to move it to a safe location. | |
21955 | ||
21956 | Configuring with @samp{--enable-profiling} arranges for @value{GDBN} to be | |
b383017d | 21957 | compiled with the @samp{-pg} compiler option. |
e7ba9c65 | 21958 | |
09d4efe1 EZ |
21959 | @kindex maint show-debug-regs |
21960 | @cindex x86 hardware debug registers | |
21961 | @item maint show-debug-regs | |
21962 | Control whether to show variables that mirror the x86 hardware debug | |
21963 | registers. Use @code{ON} to enable, @code{OFF} to disable. If | |
21964 | enabled, the debug registers values are shown when GDB inserts or | |
21965 | removes a hardware breakpoint or watchpoint, and when the inferior | |
21966 | triggers a hardware-assisted breakpoint or watchpoint. | |
21967 | ||
21968 | @kindex maint space | |
21969 | @cindex memory used by commands | |
21970 | @item maint space | |
21971 | Control whether to display memory usage for each command. If set to a | |
21972 | nonzero value, @value{GDBN} will display how much memory each command | |
21973 | took, following the command's own output. This can also be requested | |
21974 | by invoking @value{GDBN} with the @option{--statistics} command-line | |
21975 | switch (@pxref{Mode Options}). | |
21976 | ||
21977 | @kindex maint time | |
21978 | @cindex time of command execution | |
21979 | @item maint time | |
21980 | Control whether to display the execution time for each command. If | |
21981 | set to a nonzero value, @value{GDBN} will display how much time it | |
21982 | took to execute each command, following the command's own output. | |
21983 | This can also be requested by invoking @value{GDBN} with the | |
21984 | @option{--statistics} command-line switch (@pxref{Mode Options}). | |
21985 | ||
21986 | @kindex maint translate-address | |
21987 | @item maint translate-address @r{[}@var{section}@r{]} @var{addr} | |
21988 | Find the symbol stored at the location specified by the address | |
21989 | @var{addr} and an optional section name @var{section}. If found, | |
21990 | @value{GDBN} prints the name of the closest symbol and an offset from | |
21991 | the symbol's location to the specified address. This is similar to | |
21992 | the @code{info address} command (@pxref{Symbols}), except that this | |
21993 | command also allows to find symbols in other sections. | |
ae038cb0 | 21994 | |
8e04817f | 21995 | @end table |
c906108c | 21996 | |
9c16f35a EZ |
21997 | The following command is useful for non-interactive invocations of |
21998 | @value{GDBN}, such as in the test suite. | |
21999 | ||
22000 | @table @code | |
22001 | @item set watchdog @var{nsec} | |
22002 | @kindex set watchdog | |
22003 | @cindex watchdog timer | |
22004 | @cindex timeout for commands | |
22005 | Set the maximum number of seconds @value{GDBN} will wait for the | |
22006 | target operation to finish. If this time expires, @value{GDBN} | |
22007 | reports and error and the command is aborted. | |
22008 | ||
22009 | @item show watchdog | |
22010 | Show the current setting of the target wait timeout. | |
22011 | @end table | |
c906108c | 22012 | |
e0ce93ac | 22013 | @node Remote Protocol |
8e04817f | 22014 | @appendix @value{GDBN} Remote Serial Protocol |
c906108c | 22015 | |
ee2d5c50 AC |
22016 | @menu |
22017 | * Overview:: | |
22018 | * Packets:: | |
22019 | * Stop Reply Packets:: | |
22020 | * General Query Packets:: | |
22021 | * Register Packet Format:: | |
9d29849a | 22022 | * Tracepoint Packets:: |
9a6253be | 22023 | * Interrupts:: |
ee2d5c50 | 22024 | * Examples:: |
0ce1b118 | 22025 | * File-I/O remote protocol extension:: |
ee2d5c50 AC |
22026 | @end menu |
22027 | ||
22028 | @node Overview | |
22029 | @section Overview | |
22030 | ||
8e04817f AC |
22031 | There may be occasions when you need to know something about the |
22032 | protocol---for example, if there is only one serial port to your target | |
22033 | machine, you might want your program to do something special if it | |
22034 | recognizes a packet meant for @value{GDBN}. | |
c906108c | 22035 | |
d2c6833e | 22036 | In the examples below, @samp{->} and @samp{<-} are used to indicate |
8e04817f | 22037 | transmitted and received data respectfully. |
c906108c | 22038 | |
8e04817f AC |
22039 | @cindex protocol, @value{GDBN} remote serial |
22040 | @cindex serial protocol, @value{GDBN} remote | |
22041 | @cindex remote serial protocol | |
22042 | All @value{GDBN} commands and responses (other than acknowledgments) are | |
22043 | sent as a @var{packet}. A @var{packet} is introduced with the character | |
22044 | @samp{$}, the actual @var{packet-data}, and the terminating character | |
22045 | @samp{#} followed by a two-digit @var{checksum}: | |
c906108c | 22046 | |
474c8240 | 22047 | @smallexample |
8e04817f | 22048 | @code{$}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 22049 | @end smallexample |
8e04817f | 22050 | @noindent |
c906108c | 22051 | |
8e04817f AC |
22052 | @cindex checksum, for @value{GDBN} remote |
22053 | @noindent | |
22054 | The two-digit @var{checksum} is computed as the modulo 256 sum of all | |
22055 | characters between the leading @samp{$} and the trailing @samp{#} (an | |
22056 | eight bit unsigned checksum). | |
c906108c | 22057 | |
8e04817f AC |
22058 | Implementors should note that prior to @value{GDBN} 5.0 the protocol |
22059 | specification also included an optional two-digit @var{sequence-id}: | |
c906108c | 22060 | |
474c8240 | 22061 | @smallexample |
8e04817f | 22062 | @code{$}@var{sequence-id}@code{:}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 22063 | @end smallexample |
c906108c | 22064 | |
8e04817f AC |
22065 | @cindex sequence-id, for @value{GDBN} remote |
22066 | @noindent | |
22067 | That @var{sequence-id} was appended to the acknowledgment. @value{GDBN} | |
22068 | has never output @var{sequence-id}s. Stubs that handle packets added | |
22069 | since @value{GDBN} 5.0 must not accept @var{sequence-id}. | |
c906108c | 22070 | |
8e04817f AC |
22071 | @cindex acknowledgment, for @value{GDBN} remote |
22072 | When either the host or the target machine receives a packet, the first | |
22073 | response expected is an acknowledgment: either @samp{+} (to indicate | |
22074 | the package was received correctly) or @samp{-} (to request | |
22075 | retransmission): | |
c906108c | 22076 | |
474c8240 | 22077 | @smallexample |
d2c6833e AC |
22078 | -> @code{$}@var{packet-data}@code{#}@var{checksum} |
22079 | <- @code{+} | |
474c8240 | 22080 | @end smallexample |
8e04817f | 22081 | @noindent |
53a5351d | 22082 | |
8e04817f AC |
22083 | The host (@value{GDBN}) sends @var{command}s, and the target (the |
22084 | debugging stub incorporated in your program) sends a @var{response}. In | |
22085 | the case of step and continue @var{command}s, the response is only sent | |
22086 | when the operation has completed (the target has again stopped). | |
c906108c | 22087 | |
8e04817f AC |
22088 | @var{packet-data} consists of a sequence of characters with the |
22089 | exception of @samp{#} and @samp{$} (see @samp{X} packet for additional | |
22090 | exceptions). | |
c906108c | 22091 | |
8e04817f | 22092 | Fields within the packet should be separated using @samp{,} @samp{;} or |
ee2d5c50 | 22093 | @cindex remote protocol, field separator |
8e04817f | 22094 | @samp{:}. Except where otherwise noted all numbers are represented in |
ee2d5c50 | 22095 | @sc{hex} with leading zeros suppressed. |
c906108c | 22096 | |
8e04817f AC |
22097 | Implementors should note that prior to @value{GDBN} 5.0, the character |
22098 | @samp{:} could not appear as the third character in a packet (as it | |
22099 | would potentially conflict with the @var{sequence-id}). | |
c906108c | 22100 | |
8e04817f AC |
22101 | Response @var{data} can be run-length encoded to save space. A @samp{*} |
22102 | means that the next character is an @sc{ascii} encoding giving a repeat count | |
22103 | which stands for that many repetitions of the character preceding the | |
22104 | @samp{*}. The encoding is @code{n+29}, yielding a printable character | |
22105 | where @code{n >=3} (which is where rle starts to win). The printable | |
22106 | characters @samp{$}, @samp{#}, @samp{+} and @samp{-} or with a numeric | |
22107 | value greater than 126 should not be used. | |
c906108c | 22108 | |
8e04817f | 22109 | So: |
474c8240 | 22110 | @smallexample |
8e04817f | 22111 | "@code{0* }" |
474c8240 | 22112 | @end smallexample |
8e04817f AC |
22113 | @noindent |
22114 | means the same as "0000". | |
c906108c | 22115 | |
8e04817f AC |
22116 | The error response returned for some packets includes a two character |
22117 | error number. That number is not well defined. | |
c906108c | 22118 | |
8e04817f AC |
22119 | For any @var{command} not supported by the stub, an empty response |
22120 | (@samp{$#00}) should be returned. That way it is possible to extend the | |
22121 | protocol. A newer @value{GDBN} can tell if a packet is supported based | |
22122 | on that response. | |
c906108c | 22123 | |
b383017d RM |
22124 | A stub is required to support the @samp{g}, @samp{G}, @samp{m}, @samp{M}, |
22125 | @samp{c}, and @samp{s} @var{command}s. All other @var{command}s are | |
8e04817f | 22126 | optional. |
c906108c | 22127 | |
ee2d5c50 AC |
22128 | @node Packets |
22129 | @section Packets | |
22130 | ||
22131 | The following table provides a complete list of all currently defined | |
22132 | @var{command}s and their corresponding response @var{data}. | |
9c16f35a EZ |
22133 | @xref{File-I/O remote protocol extension}, for details about the File |
22134 | I/O extension of the remote protocol. | |
ee2d5c50 | 22135 | |
b8ff78ce JB |
22136 | Each packet's description has a template showing the packet's overall |
22137 | syntax, followed by an explanation of the packet's meaning. We | |
22138 | include spaces in some of the templates for clarity; these are not | |
22139 | part of the packet's syntax. No @value{GDBN} packet uses spaces to | |
22140 | separate its components. For example, a template like @samp{foo | |
22141 | @var{bar} @var{baz}} describes a packet beginning with the three ASCII | |
22142 | bytes @samp{foo}, followed by a @var{bar}, followed directly by a | |
22143 | @var{baz}. GDB does not transmit a space character between the | |
22144 | @samp{foo} and the @var{bar}, or between the @var{bar} and the | |
22145 | @var{baz}. | |
22146 | ||
8ffe2530 JB |
22147 | Note that all packet forms beginning with an upper- or lower-case |
22148 | letter, other than those described here, are reserved for future use. | |
22149 | ||
b8ff78ce | 22150 | Here are the packet descriptions. |
ee2d5c50 | 22151 | |
b8ff78ce | 22152 | @table @samp |
ee2d5c50 | 22153 | |
b8ff78ce JB |
22154 | @item ! |
22155 | @cindex @samp{!} packet | |
8e04817f AC |
22156 | Enable extended mode. In extended mode, the remote server is made |
22157 | persistent. The @samp{R} packet is used to restart the program being | |
22158 | debugged. | |
ee2d5c50 AC |
22159 | |
22160 | Reply: | |
22161 | @table @samp | |
22162 | @item OK | |
8e04817f | 22163 | The remote target both supports and has enabled extended mode. |
ee2d5c50 | 22164 | @end table |
c906108c | 22165 | |
b8ff78ce JB |
22166 | @item ? |
22167 | @cindex @samp{?} packet | |
ee2d5c50 AC |
22168 | Indicate the reason the target halted. The reply is the same as for |
22169 | step and continue. | |
c906108c | 22170 | |
ee2d5c50 AC |
22171 | Reply: |
22172 | @xref{Stop Reply Packets}, for the reply specifications. | |
22173 | ||
b8ff78ce JB |
22174 | @item A @var{arglen},@var{argnum},@var{arg},@dots{} |
22175 | @cindex @samp{A} packet | |
22176 | Initialized @code{argv[]} array passed into program. @var{arglen} | |
22177 | specifies the number of bytes in the hex encoded byte stream | |
22178 | @var{arg}. See @code{gdbserver} for more details. | |
ee2d5c50 AC |
22179 | |
22180 | Reply: | |
22181 | @table @samp | |
22182 | @item OK | |
b8ff78ce JB |
22183 | The arguments were set. |
22184 | @item E @var{NN} | |
22185 | An error occurred. | |
ee2d5c50 AC |
22186 | @end table |
22187 | ||
b8ff78ce JB |
22188 | @item b @var{baud} |
22189 | @cindex @samp{b} packet | |
22190 | (Don't use this packet; its behavior is not well-defined.) | |
ee2d5c50 AC |
22191 | Change the serial line speed to @var{baud}. |
22192 | ||
22193 | JTC: @emph{When does the transport layer state change? When it's | |
22194 | received, or after the ACK is transmitted. In either case, there are | |
22195 | problems if the command or the acknowledgment packet is dropped.} | |
22196 | ||
22197 | Stan: @emph{If people really wanted to add something like this, and get | |
22198 | it working for the first time, they ought to modify ser-unix.c to send | |
22199 | some kind of out-of-band message to a specially-setup stub and have the | |
22200 | switch happen "in between" packets, so that from remote protocol's point | |
22201 | of view, nothing actually happened.} | |
22202 | ||
b8ff78ce JB |
22203 | @item B @var{addr},@var{mode} |
22204 | @cindex @samp{B} packet | |
8e04817f | 22205 | Set (@var{mode} is @samp{S}) or clear (@var{mode} is @samp{C}) a |
2f870471 AC |
22206 | breakpoint at @var{addr}. |
22207 | ||
b8ff78ce | 22208 | Don't use this packet. Use the @samp{Z} and @samp{z} packets instead |
2f870471 | 22209 | (@pxref{insert breakpoint or watchpoint packet}). |
c906108c | 22210 | |
b8ff78ce JB |
22211 | @item c @var{addr} |
22212 | @cindex @samp{c} packet | |
22213 | Continue. @var{addr} is address to resume. If @var{addr} is omitted, | |
22214 | resume at current address. | |
c906108c | 22215 | |
ee2d5c50 AC |
22216 | Reply: |
22217 | @xref{Stop Reply Packets}, for the reply specifications. | |
22218 | ||
b8ff78ce JB |
22219 | @item C @var{sig};@var{addr} |
22220 | @cindex @samp{C} packet | |
8e04817f | 22221 | Continue with signal @var{sig} (hex signal number). If |
b8ff78ce | 22222 | @samp{;@var{addr}} is omitted, resume at same address. |
c906108c | 22223 | |
ee2d5c50 AC |
22224 | Reply: |
22225 | @xref{Stop Reply Packets}, for the reply specifications. | |
c906108c | 22226 | |
b8ff78ce JB |
22227 | @item d |
22228 | @cindex @samp{d} packet | |
ee2d5c50 AC |
22229 | Toggle debug flag. |
22230 | ||
b8ff78ce JB |
22231 | Don't use this packet; instead, define a general set packet |
22232 | (@pxref{General Query Packets}). | |
ee2d5c50 | 22233 | |
b8ff78ce JB |
22234 | @item D |
22235 | @cindex @samp{D} packet | |
ee2d5c50 | 22236 | Detach @value{GDBN} from the remote system. Sent to the remote target |
07f31aa6 | 22237 | before @value{GDBN} disconnects via the @code{detach} command. |
ee2d5c50 AC |
22238 | |
22239 | Reply: | |
22240 | @table @samp | |
10fac096 NW |
22241 | @item OK |
22242 | for success | |
b8ff78ce | 22243 | @item E @var{NN} |
10fac096 | 22244 | for an error |
ee2d5c50 | 22245 | @end table |
c906108c | 22246 | |
b8ff78ce JB |
22247 | @item F @var{RC},@var{EE},@var{CF};@var{XX} |
22248 | @cindex @samp{F} packet | |
22249 | A reply from @value{GDBN} to an @samp{F} packet sent by the target. | |
22250 | This is part of the File-I/O protocol extension. @xref{File-I/O | |
22251 | remote protocol extension}, for the specification. | |
ee2d5c50 | 22252 | |
b8ff78ce | 22253 | @item g |
ee2d5c50 | 22254 | @anchor{read registers packet} |
b8ff78ce | 22255 | @cindex @samp{g} packet |
ee2d5c50 AC |
22256 | Read general registers. |
22257 | ||
22258 | Reply: | |
22259 | @table @samp | |
22260 | @item @var{XX@dots{}} | |
8e04817f AC |
22261 | Each byte of register data is described by two hex digits. The bytes |
22262 | with the register are transmitted in target byte order. The size of | |
b8ff78ce | 22263 | each register and their position within the @samp{g} packet are |
12c266ea | 22264 | determined by the @value{GDBN} internal macros |
b8ff78ce JB |
22265 | @code{DEPRECATED_REGISTER_RAW_SIZE} and @code{REGISTER_NAME} macros. The |
22266 | specification of several standard @samp{g} packets is specified below. | |
22267 | @item E @var{NN} | |
ee2d5c50 AC |
22268 | for an error. |
22269 | @end table | |
c906108c | 22270 | |
b8ff78ce JB |
22271 | @item G @var{XX@dots{}} |
22272 | @cindex @samp{G} packet | |
22273 | Write general registers. @xref{read registers packet}, for a | |
22274 | description of the @var{XX@dots{}} data. | |
ee2d5c50 AC |
22275 | |
22276 | Reply: | |
22277 | @table @samp | |
22278 | @item OK | |
22279 | for success | |
b8ff78ce | 22280 | @item E @var{NN} |
ee2d5c50 AC |
22281 | for an error |
22282 | @end table | |
22283 | ||
b8ff78ce JB |
22284 | @item H @var{c} @var{t} |
22285 | @cindex @samp{H} packet | |
8e04817f | 22286 | Set thread for subsequent operations (@samp{m}, @samp{M}, @samp{g}, |
ee2d5c50 AC |
22287 | @samp{G}, et.al.). @var{c} depends on the operation to be performed: it |
22288 | should be @samp{c} for step and continue operations, @samp{g} for other | |
b8ff78ce JB |
22289 | operations. The thread designator @var{t} may be @samp{-1}, meaning all |
22290 | the threads, a thread number, or @samp{0} which means pick any thread. | |
ee2d5c50 AC |
22291 | |
22292 | Reply: | |
22293 | @table @samp | |
22294 | @item OK | |
22295 | for success | |
b8ff78ce | 22296 | @item E @var{NN} |
ee2d5c50 AC |
22297 | for an error |
22298 | @end table | |
c906108c | 22299 | |
8e04817f AC |
22300 | @c FIXME: JTC: |
22301 | @c 'H': How restrictive (or permissive) is the thread model. If a | |
22302 | @c thread is selected and stopped, are other threads allowed | |
22303 | @c to continue to execute? As I mentioned above, I think the | |
22304 | @c semantics of each command when a thread is selected must be | |
22305 | @c described. For example: | |
22306 | @c | |
22307 | @c 'g': If the stub supports threads and a specific thread is | |
22308 | @c selected, returns the register block from that thread; | |
22309 | @c otherwise returns current registers. | |
22310 | @c | |
22311 | @c 'G' If the stub supports threads and a specific thread is | |
22312 | @c selected, sets the registers of the register block of | |
22313 | @c that thread; otherwise sets current registers. | |
c906108c | 22314 | |
b8ff78ce | 22315 | @item i @r{[}@var{addr}@r{[},@var{nnn}@r{]]} |
ee2d5c50 | 22316 | @anchor{cycle step packet} |
b8ff78ce JB |
22317 | @cindex @samp{i} packet |
22318 | Step the remote target by a single clock cycle. If @samp{,@var{nnn}} is | |
8e04817f AC |
22319 | present, cycle step @var{nnn} cycles. If @var{addr} is present, cycle |
22320 | step starting at that address. | |
c906108c | 22321 | |
b8ff78ce JB |
22322 | @item I |
22323 | @cindex @samp{I} packet | |
22324 | Signal, then cycle step. @xref{step with signal packet}. @xref{cycle | |
22325 | step packet}. | |
ee2d5c50 | 22326 | |
b8ff78ce JB |
22327 | @item k |
22328 | @cindex @samp{k} packet | |
22329 | Kill request. | |
c906108c | 22330 | |
ac282366 | 22331 | FIXME: @emph{There is no description of how to operate when a specific |
ee2d5c50 AC |
22332 | thread context has been selected (i.e.@: does 'k' kill only that |
22333 | thread?)}. | |
c906108c | 22334 | |
b8ff78ce JB |
22335 | @item m @var{addr},@var{length} |
22336 | @cindex @samp{m} packet | |
8e04817f | 22337 | Read @var{length} bytes of memory starting at address @var{addr}. |
fb031cdf JB |
22338 | Note that @var{addr} may not be aligned to any particular boundary. |
22339 | ||
22340 | The stub need not use any particular size or alignment when gathering | |
22341 | data from memory for the response; even if @var{addr} is word-aligned | |
22342 | and @var{length} is a multiple of the word size, the stub is free to | |
22343 | use byte accesses, or not. For this reason, this packet may not be | |
22344 | suitable for accessing memory-mapped I/O devices. | |
c43c5473 JB |
22345 | @cindex alignment of remote memory accesses |
22346 | @cindex size of remote memory accesses | |
22347 | @cindex memory, alignment and size of remote accesses | |
c906108c | 22348 | |
ee2d5c50 AC |
22349 | Reply: |
22350 | @table @samp | |
22351 | @item @var{XX@dots{}} | |
b8ff78ce JB |
22352 | Memory contents; each byte is transmitted as a two-digit hexidecimal |
22353 | number. The reply may contain fewer bytes than requested if the | |
22354 | server was able to read only part of the region of memory. | |
22355 | @item E @var{NN} | |
ee2d5c50 AC |
22356 | @var{NN} is errno |
22357 | @end table | |
22358 | ||
b8ff78ce JB |
22359 | @item M @var{addr},@var{length}:@var{XX@dots{}} |
22360 | @cindex @samp{M} packet | |
8e04817f | 22361 | Write @var{length} bytes of memory starting at address @var{addr}. |
b8ff78ce JB |
22362 | @var{XX@dots{}} is the data; each byte is transmitted as a two-digit |
22363 | hexidecimal number. | |
ee2d5c50 AC |
22364 | |
22365 | Reply: | |
22366 | @table @samp | |
22367 | @item OK | |
22368 | for success | |
b8ff78ce | 22369 | @item E @var{NN} |
8e04817f AC |
22370 | for an error (this includes the case where only part of the data was |
22371 | written). | |
ee2d5c50 | 22372 | @end table |
c906108c | 22373 | |
b8ff78ce JB |
22374 | @item p @var{n} |
22375 | @cindex @samp{p} packet | |
22376 | Read the value of register @var{n}; @var{n} is in hex. | |
2e868123 AC |
22377 | @xref{read registers packet}, for a description of how the returned |
22378 | register value is encoded. | |
ee2d5c50 AC |
22379 | |
22380 | Reply: | |
22381 | @table @samp | |
2e868123 AC |
22382 | @item @var{XX@dots{}} |
22383 | the register's value | |
b8ff78ce | 22384 | @item E @var{NN} |
2e868123 AC |
22385 | for an error |
22386 | @item | |
22387 | Indicating an unrecognized @var{query}. | |
ee2d5c50 AC |
22388 | @end table |
22389 | ||
b8ff78ce | 22390 | @item P @var{n@dots{}}=@var{r@dots{}} |
ee2d5c50 | 22391 | @anchor{write register packet} |
b8ff78ce JB |
22392 | @cindex @samp{P} packet |
22393 | Write register @var{n@dots{}} with value @var{r@dots{}}. The register | |
22394 | number @var{n} is in hexidecimal, and @var{r@dots{}} contains two hex | |
8e04817f | 22395 | digits for each byte in the register (target byte order). |
c906108c | 22396 | |
ee2d5c50 AC |
22397 | Reply: |
22398 | @table @samp | |
22399 | @item OK | |
22400 | for success | |
b8ff78ce | 22401 | @item E @var{NN} |
ee2d5c50 AC |
22402 | for an error |
22403 | @end table | |
22404 | ||
5f3bebba JB |
22405 | @item q @var{name} @var{params}@dots{} |
22406 | @itemx Q @var{name} @var{params}@dots{} | |
b8ff78ce | 22407 | @cindex @samp{q} packet |
b8ff78ce | 22408 | @cindex @samp{Q} packet |
5f3bebba JB |
22409 | General query (@samp{q}) and set (@samp{Q}). These packets are |
22410 | described fully in @ref{General Query Packets}. | |
c906108c | 22411 | |
b8ff78ce JB |
22412 | @item r |
22413 | @cindex @samp{r} packet | |
8e04817f | 22414 | Reset the entire system. |
c906108c | 22415 | |
b8ff78ce | 22416 | Don't use this packet; use the @samp{R} packet instead. |
ee2d5c50 | 22417 | |
b8ff78ce JB |
22418 | @item R @var{XX} |
22419 | @cindex @samp{R} packet | |
8e04817f AC |
22420 | Restart the program being debugged. @var{XX}, while needed, is ignored. |
22421 | This packet is only available in extended mode. | |
ee2d5c50 | 22422 | |
8e04817f | 22423 | The @samp{R} packet has no reply. |
ee2d5c50 | 22424 | |
b8ff78ce JB |
22425 | @item s @var{addr} |
22426 | @cindex @samp{s} packet | |
22427 | Single step. @var{addr} is the address at which to resume. If | |
22428 | @var{addr} is omitted, resume at same address. | |
c906108c | 22429 | |
ee2d5c50 AC |
22430 | Reply: |
22431 | @xref{Stop Reply Packets}, for the reply specifications. | |
22432 | ||
b8ff78ce | 22433 | @item S @var{sig};@var{addr} |
ee2d5c50 | 22434 | @anchor{step with signal packet} |
b8ff78ce JB |
22435 | @cindex @samp{S} packet |
22436 | Step with signal. This is analogous to the @samp{C} packet, but | |
22437 | requests a single-step, rather than a normal resumption of execution. | |
c906108c | 22438 | |
ee2d5c50 AC |
22439 | Reply: |
22440 | @xref{Stop Reply Packets}, for the reply specifications. | |
22441 | ||
b8ff78ce JB |
22442 | @item t @var{addr}:@var{PP},@var{MM} |
22443 | @cindex @samp{t} packet | |
8e04817f | 22444 | Search backwards starting at address @var{addr} for a match with pattern |
ee2d5c50 AC |
22445 | @var{PP} and mask @var{MM}. @var{PP} and @var{MM} are 4 bytes. |
22446 | @var{addr} must be at least 3 digits. | |
c906108c | 22447 | |
b8ff78ce JB |
22448 | @item T @var{XX} |
22449 | @cindex @samp{T} packet | |
ee2d5c50 | 22450 | Find out if the thread XX is alive. |
c906108c | 22451 | |
ee2d5c50 AC |
22452 | Reply: |
22453 | @table @samp | |
22454 | @item OK | |
22455 | thread is still alive | |
b8ff78ce | 22456 | @item E @var{NN} |
ee2d5c50 AC |
22457 | thread is dead |
22458 | @end table | |
22459 | ||
b8ff78ce JB |
22460 | @item v |
22461 | Packets starting with @samp{v} are identified by a multi-letter name, | |
22462 | up to the first @samp{;} or @samp{?} (or the end of the packet). | |
86d30acc | 22463 | |
b8ff78ce JB |
22464 | @item vCont@r{[};@var{action}@r{[}:@var{tid}@r{]]}@dots{} |
22465 | @cindex @samp{vCont} packet | |
22466 | Resume the inferior, specifying different actions for each thread. | |
86d30acc DJ |
22467 | If an action is specified with no @var{tid}, then it is applied to any |
22468 | threads that don't have a specific action specified; if no default action is | |
22469 | specified then other threads should remain stopped. Specifying multiple | |
22470 | default actions is an error; specifying no actions is also an error. | |
22471 | Thread IDs are specified in hexadecimal. Currently supported actions are: | |
22472 | ||
b8ff78ce | 22473 | @table @samp |
86d30acc DJ |
22474 | @item c |
22475 | Continue. | |
b8ff78ce | 22476 | @item C @var{sig} |
86d30acc DJ |
22477 | Continue with signal @var{sig}. @var{sig} should be two hex digits. |
22478 | @item s | |
22479 | Step. | |
b8ff78ce | 22480 | @item S @var{sig} |
86d30acc DJ |
22481 | Step with signal @var{sig}. @var{sig} should be two hex digits. |
22482 | @end table | |
22483 | ||
22484 | The optional @var{addr} argument normally associated with these packets is | |
b8ff78ce | 22485 | not supported in @samp{vCont}. |
86d30acc DJ |
22486 | |
22487 | Reply: | |
22488 | @xref{Stop Reply Packets}, for the reply specifications. | |
22489 | ||
b8ff78ce JB |
22490 | @item vCont? |
22491 | @cindex @samp{vCont?} packet | |
22492 | Request a list of actions supporetd by the @samp{vCont} packet. | |
86d30acc DJ |
22493 | |
22494 | Reply: | |
22495 | @table @samp | |
b8ff78ce JB |
22496 | @item vCont@r{[};@var{action}@dots{}@r{]} |
22497 | The @samp{vCont} packet is supported. Each @var{action} is a supported | |
22498 | command in the @samp{vCont} packet. | |
86d30acc | 22499 | @item |
b8ff78ce | 22500 | The @samp{vCont} packet is not supported. |
86d30acc | 22501 | @end table |
ee2d5c50 | 22502 | |
b8ff78ce | 22503 | @item X @var{addr},@var{length}:@var{XX@dots{}} |
9a6253be | 22504 | @anchor{X packet} |
b8ff78ce JB |
22505 | @cindex @samp{X} packet |
22506 | Write data to memory, where the data is transmitted in binary. | |
22507 | @var{addr} is address, @var{length} is number of bytes, | |
22508 | @samp{@var{XX}@dots{}} is binary data. The bytes @code{0x23} | |
22509 | (@sc{ascii} @samp{#}), @code{0x24} (@sc{ascii} @samp{$}), and | |
22510 | @code{0x7d} (@sc{ascii} @samp{@}}) are escaped using @code{0x7d} | |
22511 | (@sc{ascii} @samp{@}}), and then XORed with @code{0x20}. For example, | |
22512 | the byte @code{0x7d} would be transmitted as the two bytes @code{0x7d | |
22513 | 0x5d}. | |
c906108c | 22514 | |
ee2d5c50 AC |
22515 | Reply: |
22516 | @table @samp | |
22517 | @item OK | |
22518 | for success | |
b8ff78ce | 22519 | @item E @var{NN} |
ee2d5c50 AC |
22520 | for an error |
22521 | @end table | |
22522 | ||
b8ff78ce JB |
22523 | @item z @var{type},@var{addr},@var{length} |
22524 | @itemx Z @var{type},@var{addr},@var{length} | |
2f870471 | 22525 | @anchor{insert breakpoint or watchpoint packet} |
b8ff78ce JB |
22526 | @cindex @samp{z} packet |
22527 | @cindex @samp{Z} packets | |
22528 | Insert (@samp{Z}) or remove (@samp{z}) a @var{type} breakpoint or | |
2f870471 AC |
22529 | watchpoint starting at address @var{address} and covering the next |
22530 | @var{length} bytes. | |
ee2d5c50 | 22531 | |
2f870471 AC |
22532 | Each breakpoint and watchpoint packet @var{type} is documented |
22533 | separately. | |
22534 | ||
512217c7 AC |
22535 | @emph{Implementation notes: A remote target shall return an empty string |
22536 | for an unrecognized breakpoint or watchpoint packet @var{type}. A | |
22537 | remote target shall support either both or neither of a given | |
b8ff78ce | 22538 | @samp{Z@var{type}@dots{}} and @samp{z@var{type}@dots{}} packet pair. To |
2f870471 AC |
22539 | avoid potential problems with duplicate packets, the operations should |
22540 | be implemented in an idempotent way.} | |
22541 | ||
b8ff78ce JB |
22542 | @item z0,@var{addr},@var{length} |
22543 | @itemx Z0,@var{addr},@var{length} | |
22544 | @cindex @samp{z0} packet | |
22545 | @cindex @samp{Z0} packet | |
22546 | Insert (@samp{Z0}) or remove (@samp{z0}) a memory breakpoint at address | |
22547 | @var{addr} of size @var{length}. | |
2f870471 AC |
22548 | |
22549 | A memory breakpoint is implemented by replacing the instruction at | |
22550 | @var{addr} with a software breakpoint or trap instruction. The | |
b8ff78ce | 22551 | @var{length} is used by targets that indicates the size of the |
2f870471 AC |
22552 | breakpoint (in bytes) that should be inserted (e.g., the @sc{arm} and |
22553 | @sc{mips} can insert either a 2 or 4 byte breakpoint). | |
c906108c | 22554 | |
2f870471 AC |
22555 | @emph{Implementation note: It is possible for a target to copy or move |
22556 | code that contains memory breakpoints (e.g., when implementing | |
22557 | overlays). The behavior of this packet, in the presence of such a | |
22558 | target, is not defined.} | |
c906108c | 22559 | |
ee2d5c50 AC |
22560 | Reply: |
22561 | @table @samp | |
2f870471 AC |
22562 | @item OK |
22563 | success | |
22564 | @item | |
22565 | not supported | |
b8ff78ce | 22566 | @item E @var{NN} |
ee2d5c50 | 22567 | for an error |
2f870471 AC |
22568 | @end table |
22569 | ||
b8ff78ce JB |
22570 | @item z1,@var{addr},@var{length} |
22571 | @itemx Z1,@var{addr},@var{length} | |
22572 | @cindex @samp{z1} packet | |
22573 | @cindex @samp{Z1} packet | |
22574 | Insert (@samp{Z1}) or remove (@samp{z1}) a hardware breakpoint at | |
22575 | address @var{addr} of size @var{length}. | |
2f870471 AC |
22576 | |
22577 | A hardware breakpoint is implemented using a mechanism that is not | |
22578 | dependant on being able to modify the target's memory. | |
22579 | ||
22580 | @emph{Implementation note: A hardware breakpoint is not affected by code | |
22581 | movement.} | |
22582 | ||
22583 | Reply: | |
22584 | @table @samp | |
ee2d5c50 | 22585 | @item OK |
2f870471 AC |
22586 | success |
22587 | @item | |
22588 | not supported | |
b8ff78ce | 22589 | @item E @var{NN} |
2f870471 AC |
22590 | for an error |
22591 | @end table | |
22592 | ||
b8ff78ce JB |
22593 | @item z2,@var{addr},@var{length} |
22594 | @itemx Z2,@var{addr},@var{length} | |
22595 | @cindex @samp{z2} packet | |
22596 | @cindex @samp{Z2} packet | |
22597 | Insert (@samp{Z2}) or remove (@samp{z2}) a write watchpoint. | |
2f870471 AC |
22598 | |
22599 | Reply: | |
22600 | @table @samp | |
22601 | @item OK | |
22602 | success | |
22603 | @item | |
22604 | not supported | |
b8ff78ce | 22605 | @item E @var{NN} |
2f870471 AC |
22606 | for an error |
22607 | @end table | |
22608 | ||
b8ff78ce JB |
22609 | @item z3,@var{addr},@var{length} |
22610 | @itemx Z3,@var{addr},@var{length} | |
22611 | @cindex @samp{z3} packet | |
22612 | @cindex @samp{Z3} packet | |
22613 | Insert (@samp{Z3}) or remove (@samp{z3}) a read watchpoint. | |
2f870471 AC |
22614 | |
22615 | Reply: | |
22616 | @table @samp | |
22617 | @item OK | |
22618 | success | |
22619 | @item | |
22620 | not supported | |
b8ff78ce | 22621 | @item E @var{NN} |
2f870471 AC |
22622 | for an error |
22623 | @end table | |
22624 | ||
b8ff78ce JB |
22625 | @item z4,@var{addr},@var{length} |
22626 | @itemx Z4,@var{addr},@var{length} | |
22627 | @cindex @samp{z4} packet | |
22628 | @cindex @samp{Z4} packet | |
22629 | Insert (@samp{Z4}) or remove (@samp{z4}) an access watchpoint. | |
2f870471 AC |
22630 | |
22631 | Reply: | |
22632 | @table @samp | |
22633 | @item OK | |
22634 | success | |
22635 | @item | |
22636 | not supported | |
b8ff78ce | 22637 | @item E @var{NN} |
2f870471 | 22638 | for an error |
ee2d5c50 AC |
22639 | @end table |
22640 | ||
22641 | @end table | |
c906108c | 22642 | |
ee2d5c50 AC |
22643 | @node Stop Reply Packets |
22644 | @section Stop Reply Packets | |
22645 | @cindex stop reply packets | |
c906108c | 22646 | |
8e04817f AC |
22647 | The @samp{C}, @samp{c}, @samp{S}, @samp{s} and @samp{?} packets can |
22648 | receive any of the below as a reply. In the case of the @samp{C}, | |
22649 | @samp{c}, @samp{S} and @samp{s} packets, that reply is only returned | |
b8ff78ce JB |
22650 | when the target halts. In the below the exact meaning of @dfn{signal |
22651 | number} is poorly defined. In general one of the UNIX signal | |
22652 | numbering conventions is used. | |
c906108c | 22653 | |
b8ff78ce JB |
22654 | As in the description of request packets, we include spaces in the |
22655 | reply templates for clarity; these are not part of the reply packet's | |
22656 | syntax. No @value{GDBN} stop reply packet uses spaces to separate its | |
22657 | components. | |
c906108c | 22658 | |
b8ff78ce | 22659 | @table @samp |
ee2d5c50 | 22660 | |
b8ff78ce JB |
22661 | @item S @var{AA} |
22662 | The program received signal number @var{AA} (a two-digit hexidecimal | |
22663 | number). | |
c906108c | 22664 | |
b8ff78ce JB |
22665 | @item T @var{AA} @var{n1}:@var{r1};@var{n2}:@var{r2};@dots{} |
22666 | @cindex @samp{T} packet reply | |
22667 | The program received signal number @var{AA} (a two-digit hexidecimal | |
22668 | number). Single-step and breakpoint traps are reported this way. The | |
22669 | @samp{@var{n}:@var{r}} pairs give the values of important registers or | |
22670 | other information: | |
22671 | @enumerate | |
22672 | @item | |
22673 | If @var{n} is a hexidecimal number, it is a register number, and the | |
22674 | corresponding @var{r} gives that register's value. @var{r} is a | |
22675 | series of bytes in target byte order, with each byte given by a | |
22676 | two-digit hex number. | |
22677 | @item | |
22678 | If @var{n} is @samp{thread}, then @var{r} is the thread process ID, in | |
22679 | hex. | |
22680 | @item | |
22681 | If @var{n} is @samp{watch}, @samp{rwatch}, or @samp{awatch}, then the | |
22682 | packet indicates a watchpoint hit, and @var{r} is the data address, in | |
22683 | hex. | |
22684 | @item | |
22685 | Otherwise, @value{GDBN} should ignore this @samp{@var{n}:@var{r}} pair | |
22686 | and go on to the next; this allows us to extend the protocol in the | |
22687 | future. | |
22688 | @end enumerate | |
ee2d5c50 | 22689 | |
b8ff78ce | 22690 | @item W @var{AA} |
8e04817f | 22691 | The process exited, and @var{AA} is the exit status. This is only |
ee2d5c50 AC |
22692 | applicable to certain targets. |
22693 | ||
b8ff78ce | 22694 | @item X @var{AA} |
8e04817f | 22695 | The process terminated with signal @var{AA}. |
c906108c | 22696 | |
b8ff78ce JB |
22697 | @item O @var{XX}@dots{} |
22698 | @samp{@var{XX}@dots{}} is hex encoding of @sc{ascii} data, to be | |
22699 | written as the program's console output. This can happen at any time | |
22700 | while the program is running and the debugger should continue to wait | |
22701 | for @samp{W}, @samp{T}, etc. | |
0ce1b118 | 22702 | |
b8ff78ce | 22703 | @item F @var{call-id},@var{parameter}@dots{} |
0ce1b118 CV |
22704 | @var{call-id} is the identifier which says which host system call should |
22705 | be called. This is just the name of the function. Translation into the | |
22706 | correct system call is only applicable as it's defined in @value{GDBN}. | |
22707 | @xref{File-I/O remote protocol extension}, for a list of implemented | |
22708 | system calls. | |
22709 | ||
b8ff78ce JB |
22710 | @samp{@var{parameter}@dots{}} is a list of parameters as defined for |
22711 | this very system call. | |
0ce1b118 | 22712 | |
b8ff78ce JB |
22713 | The target replies with this packet when it expects @value{GDBN} to |
22714 | call a host system call on behalf of the target. @value{GDBN} replies | |
22715 | with an appropriate @samp{F} packet and keeps up waiting for the next | |
22716 | reply packet from the target. The latest @samp{C}, @samp{c}, @samp{S} | |
22717 | or @samp{s} action is expected to be continued. @xref{File-I/O remote | |
22718 | protocol extension}, for more details. | |
0ce1b118 | 22719 | |
ee2d5c50 AC |
22720 | @end table |
22721 | ||
22722 | @node General Query Packets | |
22723 | @section General Query Packets | |
9c16f35a | 22724 | @cindex remote query requests |
c906108c | 22725 | |
5f3bebba JB |
22726 | Packets starting with @samp{q} are @dfn{general query packets}; |
22727 | packets starting with @samp{Q} are @dfn{general set packets}. General | |
22728 | query and set packets are a semi-unified form for retrieving and | |
22729 | sending information to and from the stub. | |
22730 | ||
22731 | The initial letter of a query or set packet is followed by a name | |
22732 | indicating what sort of thing the packet applies to. For example, | |
22733 | @value{GDBN} may use a @samp{qSymbol} packet to exchange symbol | |
22734 | definitions with the stub. These packet names follow some | |
22735 | conventions: | |
22736 | ||
22737 | @itemize @bullet | |
22738 | @item | |
22739 | The name must not contain commas, colons or semicolons. | |
22740 | @item | |
22741 | Most @value{GDBN} query and set packets have a leading upper case | |
22742 | letter. | |
22743 | @item | |
22744 | The names of custom vendor packets should use a company prefix, in | |
22745 | lower case, followed by a period. For example, packets designed at | |
22746 | the Acme Corporation might begin with @samp{qacme.foo} (for querying | |
22747 | foos) or @samp{Qacme.bar} (for setting bars). | |
22748 | @end itemize | |
22749 | ||
22750 | A query or set packet may optionally be followed by a @samp{,} or | |
22751 | @samp{;} separated list. Stubs must be careful to match the full | |
22752 | packet name, in case packet names have common prefixes. | |
c906108c | 22753 | |
b8ff78ce JB |
22754 | Like the descriptions of the other packets, each description here |
22755 | has a template showing the packet's overall syntax, followed by an | |
22756 | explanation of the packet's meaning. We include spaces in some of the | |
22757 | templates for clarity; these are not part of the packet's syntax. No | |
22758 | @value{GDBN} packet uses spaces to separate its components. | |
22759 | ||
5f3bebba JB |
22760 | Here are the currently defined query and set packets: |
22761 | ||
b8ff78ce | 22762 | @table @samp |
c906108c | 22763 | |
b8ff78ce | 22764 | @item qC |
9c16f35a | 22765 | @cindex current thread, remote request |
b8ff78ce | 22766 | @cindex @samp{qC} packet |
ee2d5c50 AC |
22767 | Return the current thread id. |
22768 | ||
22769 | Reply: | |
22770 | @table @samp | |
b8ff78ce | 22771 | @item QC @var{pid} |
e1aac25b | 22772 | Where @var{pid} is an unsigned hexidecimal process id. |
b8ff78ce | 22773 | @item @r{(anything else)} |
ee2d5c50 AC |
22774 | Any other reply implies the old pid. |
22775 | @end table | |
22776 | ||
b8ff78ce | 22777 | @item qCRC:@var{addr},@var{length} |
ff2587ec | 22778 | @cindex CRC of memory block, remote request |
b8ff78ce JB |
22779 | @cindex @samp{qCRC} packet |
22780 | Compute the CRC checksum of a block of memory. | |
ff2587ec WZ |
22781 | Reply: |
22782 | @table @samp | |
b8ff78ce | 22783 | @item E @var{NN} |
ff2587ec | 22784 | An error (such as memory fault) |
b8ff78ce JB |
22785 | @item C @var{crc32} |
22786 | The specified memory region's checksum is @var{crc32}. | |
ff2587ec WZ |
22787 | @end table |
22788 | ||
b8ff78ce JB |
22789 | @item qfThreadInfo |
22790 | @itemx qsThreadInfo | |
9c16f35a | 22791 | @cindex list active threads, remote request |
b8ff78ce JB |
22792 | @cindex @samp{qfThreadInfo} packet |
22793 | @cindex @samp{qsThreadInfo} packet | |
22794 | Obtain a list of all active thread ids from the target (OS). Since there | |
8e04817f AC |
22795 | may be too many active threads to fit into one reply packet, this query |
22796 | works iteratively: it may require more than one query/reply sequence to | |
22797 | obtain the entire list of threads. The first query of the sequence will | |
b8ff78ce JB |
22798 | be the @samp{qfThreadInfo} query; subsequent queries in the |
22799 | sequence will be the @samp{qsThreadInfo} query. | |
ee2d5c50 | 22800 | |
b8ff78ce | 22801 | NOTE: This packet replaces the @samp{qL} query (see below). |
ee2d5c50 AC |
22802 | |
22803 | Reply: | |
22804 | @table @samp | |
b8ff78ce | 22805 | @item m @var{id} |
ee2d5c50 | 22806 | A single thread id |
b8ff78ce | 22807 | @item m @var{id},@var{id}@dots{} |
ee2d5c50 | 22808 | a comma-separated list of thread ids |
b8ff78ce JB |
22809 | @item l |
22810 | (lower case letter @samp{L}) denotes end of list. | |
ee2d5c50 AC |
22811 | @end table |
22812 | ||
22813 | In response to each query, the target will reply with a list of one or | |
e1aac25b JB |
22814 | more thread ids, in big-endian unsigned hex, separated by commas. |
22815 | @value{GDBN} will respond to each reply with a request for more thread | |
b8ff78ce JB |
22816 | ids (using the @samp{qs} form of the query), until the target responds |
22817 | with @samp{l} (lower-case el, for @dfn{last}). | |
c906108c | 22818 | |
b8ff78ce | 22819 | @item qGetTLSAddr:@var{thread-id},@var{offset},@var{lm} |
ff2587ec | 22820 | @cindex get thread-local storage address, remote request |
b8ff78ce | 22821 | @cindex @samp{qGetTLSAddr} packet |
ff2587ec WZ |
22822 | Fetch the address associated with thread local storage specified |
22823 | by @var{thread-id}, @var{offset}, and @var{lm}. | |
22824 | ||
22825 | @var{thread-id} is the (big endian, hex encoded) thread id associated with the | |
22826 | thread for which to fetch the TLS address. | |
22827 | ||
22828 | @var{offset} is the (big endian, hex encoded) offset associated with the | |
22829 | thread local variable. (This offset is obtained from the debug | |
22830 | information associated with the variable.) | |
22831 | ||
22832 | @var{lm} is the (big endian, hex encoded) OS/ABI specific encoding of the | |
22833 | the load module associated with the thread local storage. For example, | |
22834 | a @sc{gnu}/Linux system will pass the link map address of the shared | |
22835 | object associated with the thread local storage under consideration. | |
22836 | Other operating environments may choose to represent the load module | |
22837 | differently, so the precise meaning of this parameter will vary. | |
ee2d5c50 AC |
22838 | |
22839 | Reply: | |
b8ff78ce JB |
22840 | @table @samp |
22841 | @item @var{XX}@dots{} | |
ff2587ec WZ |
22842 | Hex encoded (big endian) bytes representing the address of the thread |
22843 | local storage requested. | |
22844 | ||
b8ff78ce JB |
22845 | @item E @var{nn} |
22846 | An error occurred. @var{nn} are hex digits. | |
ff2587ec | 22847 | |
b8ff78ce JB |
22848 | @item |
22849 | An empty reply indicates that @samp{qGetTLSAddr} is not supported by the stub. | |
ee2d5c50 AC |
22850 | @end table |
22851 | ||
ff2587ec WZ |
22852 | Use of this request packet is controlled by the @code{set remote |
22853 | get-thread-local-storage-address} command (@pxref{Remote | |
22854 | configuration, set remote get-thread-local-storage-address}). | |
22855 | ||
b8ff78ce | 22856 | @item qL @var{startflag} @var{threadcount} @var{nextthread} |
8e04817f AC |
22857 | Obtain thread information from RTOS. Where: @var{startflag} (one hex |
22858 | digit) is one to indicate the first query and zero to indicate a | |
22859 | subsequent query; @var{threadcount} (two hex digits) is the maximum | |
22860 | number of threads the response packet can contain; and @var{nextthread} | |
22861 | (eight hex digits), for subsequent queries (@var{startflag} is zero), is | |
22862 | returned in the response as @var{argthread}. | |
ee2d5c50 | 22863 | |
b8ff78ce | 22864 | Don't use this packet; use the @samp{qfThreadInfo} query instead (see above). |
ee2d5c50 AC |
22865 | |
22866 | Reply: | |
22867 | @table @samp | |
b8ff78ce | 22868 | @item qM @var{count} @var{done} @var{argthread} @var{thread}@dots{} |
8e04817f AC |
22869 | Where: @var{count} (two hex digits) is the number of threads being |
22870 | returned; @var{done} (one hex digit) is zero to indicate more threads | |
22871 | and one indicates no further threads; @var{argthreadid} (eight hex | |
b8ff78ce | 22872 | digits) is @var{nextthread} from the request packet; @var{thread}@dots{} |
ee2d5c50 | 22873 | is a sequence of thread IDs from the target. @var{threadid} (eight hex |
8e04817f | 22874 | digits). See @code{remote.c:parse_threadlist_response()}. |
ee2d5c50 | 22875 | @end table |
c906108c | 22876 | |
b8ff78ce | 22877 | @item qOffsets |
9c16f35a | 22878 | @cindex section offsets, remote request |
b8ff78ce | 22879 | @cindex @samp{qOffsets} packet |
8e04817f AC |
22880 | Get section offsets that the target used when re-locating the downloaded |
22881 | image. @emph{Note: while a @code{Bss} offset is included in the | |
22882 | response, @value{GDBN} ignores this and instead applies the @code{Data} | |
22883 | offset to the @code{Bss} section.} | |
c906108c | 22884 | |
ee2d5c50 AC |
22885 | Reply: |
22886 | @table @samp | |
b8ff78ce | 22887 | @item Text=@var{xxx};Data=@var{yyy};Bss=@var{zzz} |
ee2d5c50 AC |
22888 | @end table |
22889 | ||
b8ff78ce | 22890 | @item qP @var{mode} @var{threadid} |
9c16f35a | 22891 | @cindex thread information, remote request |
b8ff78ce | 22892 | @cindex @samp{qP} packet |
8e04817f AC |
22893 | Returns information on @var{threadid}. Where: @var{mode} is a hex |
22894 | encoded 32 bit mode; @var{threadid} is a hex encoded 64 bit thread ID. | |
ee2d5c50 | 22895 | |
b8ff78ce | 22896 | Reply: see @code{remote.c:remote_unpack_thread_info_response()}. |
c906108c | 22897 | |
b8ff78ce | 22898 | @item qPart:@var{object}:read:@var{annex}:@var{offset},@var{length} |
9c16f35a | 22899 | @cindex read special object, remote request |
b8ff78ce | 22900 | @cindex @samp{qPart} packet |
649e03f6 | 22901 | Read uninterpreted bytes from the target's special data area |
b8ff78ce JB |
22902 | identified by the keyword @var{object}. Request @var{length} bytes |
22903 | starting at @var{offset} bytes into the data. The content and | |
22904 | encoding of @var{annex} is specific to the object; it can supply | |
22905 | additional details about what data to access. | |
649e03f6 | 22906 | |
b8ff78ce JB |
22907 | Here are the specific requests of this form defined so far. All |
22908 | @samp{qPart:@var{object}:read:@dots{}} requests use the same reply | |
22909 | formats, listed below. | |
649e03f6 | 22910 | |
b8ff78ce JB |
22911 | @table @samp |
22912 | @item qPart:auxv:read::@var{offset},@var{length} | |
721c2651 EZ |
22913 | Access the target's @dfn{auxiliary vector}. @xref{OS Information, |
22914 | auxiliary vector}, and see @ref{Remote configuration, | |
22915 | read-aux-vector-packet}. Note @var{annex} must be empty. | |
649e03f6 RM |
22916 | @end table |
22917 | ||
22918 | Reply: | |
b8ff78ce JB |
22919 | @table @samp |
22920 | @item OK | |
649e03f6 RM |
22921 | The @var{offset} in the request is at the end of the data. |
22922 | There is no more data to be read. | |
22923 | ||
b8ff78ce | 22924 | @item @var{XX}@dots{} |
649e03f6 RM |
22925 | Hex encoded data bytes read. |
22926 | This may be fewer bytes than the @var{length} in the request. | |
22927 | ||
b8ff78ce | 22928 | @item E00 |
649e03f6 RM |
22929 | The request was malformed, or @var{annex} was invalid. |
22930 | ||
b8ff78ce | 22931 | @item E @var{nn} |
649e03f6 RM |
22932 | The offset was invalid, or there was an error encountered reading the data. |
22933 | @var{nn} is a hex-encoded @code{errno} value. | |
22934 | ||
b8ff78ce | 22935 | @item |
649e03f6 RM |
22936 | An empty reply indicates the @var{object} or @var{annex} string was not |
22937 | recognized by the stub. | |
22938 | @end table | |
22939 | ||
b8ff78ce | 22940 | @item qPart:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{} |
9c16f35a | 22941 | @cindex write data into object, remote request |
649e03f6 | 22942 | Write uninterpreted bytes into the target's special data area |
b8ff78ce JB |
22943 | identified by the keyword @var{object}, starting at @var{offset} bytes |
22944 | into the data. @samp{@var{data}@dots{}} is the hex-encoded data to be | |
22945 | written. The content and encoding of @var{annex} is specific to the | |
22946 | object; it can supply additional details about what data to access. | |
649e03f6 RM |
22947 | |
22948 | No requests of this form are presently in use. This specification | |
22949 | serves as a placeholder to document the common format that new | |
22950 | specific request specifications ought to use. | |
22951 | ||
22952 | Reply: | |
b8ff78ce | 22953 | @table @samp |
649e03f6 RM |
22954 | @item @var{nn} |
22955 | @var{nn} (hex encoded) is the number of bytes written. | |
22956 | This may be fewer bytes than supplied in the request. | |
22957 | ||
b8ff78ce | 22958 | @item E00 |
649e03f6 RM |
22959 | The request was malformed, or @var{annex} was invalid. |
22960 | ||
b8ff78ce | 22961 | @item E @var{nn} |
649e03f6 RM |
22962 | The offset was invalid, or there was an error encountered writing the data. |
22963 | @var{nn} is a hex-encoded @code{errno} value. | |
22964 | ||
b8ff78ce | 22965 | @item |
649e03f6 RM |
22966 | An empty reply indicates the @var{object} or @var{annex} string was not |
22967 | recognized by the stub, or that the object does not support writing. | |
22968 | @end table | |
22969 | ||
b8ff78ce | 22970 | @item qPart:@var{object}:@var{operation}:@dots{} |
649e03f6 RM |
22971 | Requests of this form may be added in the future. When a stub does |
22972 | not recognize the @var{object} keyword, or its support for | |
b8ff78ce JB |
22973 | @var{object} does not recognize the @var{operation} keyword, the stub |
22974 | must respond with an empty packet. | |
83761cbd | 22975 | |
b8ff78ce | 22976 | @item qRcmd,@var{command} |
ff2587ec | 22977 | @cindex execute remote command, remote request |
b8ff78ce | 22978 | @cindex @samp{qRcmd} packet |
ff2587ec | 22979 | @var{command} (hex encoded) is passed to the local interpreter for |
b8ff78ce JB |
22980 | execution. Invalid commands should be reported using the output |
22981 | string. Before the final result packet, the target may also respond | |
22982 | with a number of intermediate @samp{O@var{output}} console output | |
22983 | packets. @emph{Implementors should note that providing access to a | |
22984 | stubs's interpreter may have security implications}. | |
fa93a9d8 | 22985 | |
ff2587ec WZ |
22986 | Reply: |
22987 | @table @samp | |
22988 | @item OK | |
22989 | A command response with no output. | |
22990 | @item @var{OUTPUT} | |
22991 | A command response with the hex encoded output string @var{OUTPUT}. | |
b8ff78ce | 22992 | @item E @var{NN} |
ff2587ec | 22993 | Indicate a badly formed request. |
b8ff78ce JB |
22994 | @item |
22995 | An empty reply indicates that @samp{qRcmd} is not recognized. | |
ff2587ec | 22996 | @end table |
fa93a9d8 | 22997 | |
b8ff78ce | 22998 | @item qSymbol:: |
ff2587ec | 22999 | @cindex symbol lookup, remote request |
b8ff78ce | 23000 | @cindex @samp{qSymbol} packet |
ff2587ec WZ |
23001 | Notify the target that @value{GDBN} is prepared to serve symbol lookup |
23002 | requests. Accept requests from the target for the values of symbols. | |
fa93a9d8 JB |
23003 | |
23004 | Reply: | |
ff2587ec | 23005 | @table @samp |
b8ff78ce | 23006 | @item OK |
ff2587ec | 23007 | The target does not need to look up any (more) symbols. |
b8ff78ce | 23008 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
23009 | The target requests the value of symbol @var{sym_name} (hex encoded). |
23010 | @value{GDBN} may provide the value by using the | |
b8ff78ce JB |
23011 | @samp{qSymbol:@var{sym_value}:@var{sym_name}} message, described |
23012 | below. | |
ff2587ec | 23013 | @end table |
83761cbd | 23014 | |
b8ff78ce | 23015 | @item qSymbol:@var{sym_value}:@var{sym_name} |
ff2587ec WZ |
23016 | Set the value of @var{sym_name} to @var{sym_value}. |
23017 | ||
23018 | @var{sym_name} (hex encoded) is the name of a symbol whose value the | |
23019 | target has previously requested. | |
23020 | ||
23021 | @var{sym_value} (hex) is the value for symbol @var{sym_name}. If | |
23022 | @value{GDBN} cannot supply a value for @var{sym_name}, then this field | |
23023 | will be empty. | |
23024 | ||
23025 | Reply: | |
23026 | @table @samp | |
b8ff78ce | 23027 | @item OK |
ff2587ec | 23028 | The target does not need to look up any (more) symbols. |
b8ff78ce | 23029 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
23030 | The target requests the value of a new symbol @var{sym_name} (hex |
23031 | encoded). @value{GDBN} will continue to supply the values of symbols | |
23032 | (if available), until the target ceases to request them. | |
fa93a9d8 | 23033 | @end table |
0abb7bc7 | 23034 | |
9d29849a JB |
23035 | @item QTDP |
23036 | @itemx QTFrame | |
23037 | @xref{Tracepoint Packets}. | |
23038 | ||
b8ff78ce | 23039 | @item qThreadExtraInfo,@var{id} |
ff2587ec | 23040 | @cindex thread attributes info, remote request |
b8ff78ce JB |
23041 | @cindex @samp{qThreadExtraInfo} packet |
23042 | Obtain a printable string description of a thread's attributes from | |
23043 | the target OS. @var{id} is a thread-id in big-endian hex. This | |
23044 | string may contain anything that the target OS thinks is interesting | |
23045 | for @value{GDBN} to tell the user about the thread. The string is | |
23046 | displayed in @value{GDBN}'s @code{info threads} display. Some | |
23047 | examples of possible thread extra info strings are @samp{Runnable}, or | |
23048 | @samp{Blocked on Mutex}. | |
ff2587ec WZ |
23049 | |
23050 | Reply: | |
23051 | @table @samp | |
b8ff78ce JB |
23052 | @item @var{XX}@dots{} |
23053 | Where @samp{@var{XX}@dots{}} is a hex encoding of @sc{ascii} data, | |
23054 | comprising the printable string containing the extra information about | |
23055 | the thread's attributes. | |
ff2587ec | 23056 | @end table |
814e32d7 | 23057 | |
9d29849a JB |
23058 | @item QTStart |
23059 | @itemx QTStop | |
23060 | @itemx QTinit | |
23061 | @itemx QTro | |
23062 | @itemx qTStatus | |
23063 | @xref{Tracepoint Packets}. | |
23064 | ||
ee2d5c50 AC |
23065 | @end table |
23066 | ||
23067 | @node Register Packet Format | |
23068 | @section Register Packet Format | |
eb12ee30 | 23069 | |
b8ff78ce | 23070 | The following @code{g}/@code{G} packets have previously been defined. |
ee2d5c50 AC |
23071 | In the below, some thirty-two bit registers are transferred as |
23072 | sixty-four bits. Those registers should be zero/sign extended (which?) | |
23073 | to fill the space allocated. Register bytes are transfered in target | |
23074 | byte order. The two nibbles within a register byte are transfered | |
23075 | most-significant - least-significant. | |
eb12ee30 | 23076 | |
ee2d5c50 | 23077 | @table @r |
eb12ee30 | 23078 | |
8e04817f | 23079 | @item MIPS32 |
ee2d5c50 | 23080 | |
8e04817f AC |
23081 | All registers are transfered as thirty-two bit quantities in the order: |
23082 | 32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point | |
23083 | registers; fsr; fir; fp. | |
eb12ee30 | 23084 | |
8e04817f | 23085 | @item MIPS64 |
ee2d5c50 | 23086 | |
8e04817f AC |
23087 | All registers are transfered as sixty-four bit quantities (including |
23088 | thirty-two bit registers such as @code{sr}). The ordering is the same | |
23089 | as @code{MIPS32}. | |
eb12ee30 | 23090 | |
ee2d5c50 AC |
23091 | @end table |
23092 | ||
9d29849a JB |
23093 | @node Tracepoint Packets |
23094 | @section Tracepoint Packets | |
23095 | @cindex tracepoint packets | |
23096 | @cindex packets, tracepoint | |
23097 | ||
23098 | Here we describe the packets @value{GDBN} uses to implement | |
23099 | tracepoints (@pxref{Tracepoints}). | |
23100 | ||
23101 | @table @samp | |
23102 | ||
23103 | @item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}@r{[}-@r{]} | |
23104 | Create a new tracepoint, number @var{n}, at @var{addr}. If @var{ena} | |
23105 | is @samp{E}, then the tracepoint is enabled; if it is @samp{D}, then | |
23106 | the tracepoint is disabled. @var{step} is the tracepoint's step | |
23107 | count, and @var{pass} is its pass count. If the trailing @samp{-} is | |
23108 | present, further @samp{QTDP} packets will follow to specify this | |
23109 | tracepoint's actions. | |
23110 | ||
23111 | Replies: | |
23112 | @table @samp | |
23113 | @item OK | |
23114 | The packet was understood and carried out. | |
23115 | @item | |
23116 | The packet was not recognized. | |
23117 | @end table | |
23118 | ||
23119 | @item QTDP:-@var{n}:@var{addr}:@r{[}S@r{]}@var{action}@dots{}@r{[}-@r{]} | |
23120 | Define actions to be taken when a tracepoint is hit. @var{n} and | |
23121 | @var{addr} must be the same as in the initial @samp{QTDP} packet for | |
23122 | this tracepoint. This packet may only be sent immediately after | |
23123 | another @samp{QTDP} packet that ended with a @samp{-}. If the | |
23124 | trailing @samp{-} is present, further @samp{QTDP} packets will follow, | |
23125 | specifying more actions for this tracepoint. | |
23126 | ||
23127 | In the series of action packets for a given tracepoint, at most one | |
23128 | can have an @samp{S} before its first @var{action}. If such a packet | |
23129 | is sent, it and the following packets define ``while-stepping'' | |
23130 | actions. Any prior packets define ordinary actions --- that is, those | |
23131 | taken when the tracepoint is first hit. If no action packet has an | |
23132 | @samp{S}, then all the packets in the series specify ordinary | |
23133 | tracepoint actions. | |
23134 | ||
23135 | The @samp{@var{action}@dots{}} portion of the packet is a series of | |
23136 | actions, concatenated without separators. Each action has one of the | |
23137 | following forms: | |
23138 | ||
23139 | @table @samp | |
23140 | ||
23141 | @item R @var{mask} | |
23142 | Collect the registers whose bits are set in @var{mask}. @var{mask} is | |
23143 | a hexidecimal number whose @var{i}'th bit is set if register number | |
23144 | @var{i} should be collected. (The least significant bit is numbered | |
23145 | zero.) Note that @var{mask} may be any number of digits long; it may | |
23146 | not fit in a 32-bit word. | |
23147 | ||
23148 | @item M @var{basereg},@var{offset},@var{len} | |
23149 | Collect @var{len} bytes of memory starting at the address in register | |
23150 | number @var{basereg}, plus @var{offset}. If @var{basereg} is | |
23151 | @samp{-1}, then the range has a fixed address: @var{offset} is the | |
23152 | address of the lowest byte to collect. The @var{basereg}, | |
23153 | @var{offset}, and @var{len} parameters are all unsigned hexidecimal | |
23154 | values (the @samp{-1} value for @var{basereg} is a special case). | |
23155 | ||
23156 | @item X @var{len},@var{expr} | |
23157 | Evaluate @var{expr}, whose length is @var{len}, and collect memory as | |
23158 | it directs. @var{expr} is an agent expression, as described in | |
23159 | @ref{Agent Expressions}. Each byte of the expression is encoded as a | |
23160 | two-digit hex number in the packet; @var{len} is the number of bytes | |
23161 | in the expression (and thus one-half the number of hex digits in the | |
23162 | packet). | |
23163 | ||
23164 | @end table | |
23165 | ||
23166 | Any number of actions may be packed together in a single @samp{QTDP} | |
23167 | packet, as long as the packet does not exceed the maximum packet | |
23168 | length (400 bytes, for many stubs). | |
23169 | ||
23170 | Replies: | |
23171 | @table @samp | |
23172 | @item OK | |
23173 | The packet was understood and carried out. | |
23174 | @item | |
23175 | The packet was not recognized. | |
23176 | @end table | |
23177 | ||
23178 | @item QTFrame:@var{n} | |
23179 | Select the @var{n}'th tracepoint frame from the buffer, and use the | |
23180 | register and memory contents recorded there to answer subsequent | |
23181 | request packets from @value{GDBN}. | |
23182 | ||
23183 | A successful reply from the stub indicates that the stub has found the | |
23184 | requested frame. The response is a series of parts, concatenated | |
23185 | without separators, describing the frame we selected. Each part has | |
23186 | one of the following forms: | |
23187 | ||
23188 | @table @samp | |
23189 | @item F @var{f} | |
23190 | The selected frame is number @var{n} in the trace frame buffer; | |
23191 | @var{f} is a hexidecimal number. If @var{f} is @samp{-1}, then there | |
23192 | was no frame matching the criteria in the request packet. | |
23193 | ||
23194 | @item T @var{t} | |
23195 | The selected trace frame records a hit of tracepoint number @var{t}; | |
23196 | @var{t} is a hexidecimal number. | |
23197 | ||
23198 | @end table | |
23199 | ||
23200 | @item QTFrame:pc:@var{addr} | |
23201 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
23202 | currently selected frame whose PC is @var{addr}; | |
23203 | @var{addr} is a hexidecimal number. | |
23204 | ||
23205 | @item QTFrame:tdp:@var{t} | |
23206 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
23207 | currently selected frame that is a hit of tracepoint @var{t}; @var{t} | |
23208 | is a hexidecimal number. | |
23209 | ||
23210 | @item QTFrame:range:@var{start}:@var{end} | |
23211 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
23212 | currently selected frame whose PC is between @var{start} (inclusive) | |
23213 | and @var{end} (exclusive); @var{start} and @var{end} are hexidecimal | |
23214 | numbers. | |
23215 | ||
23216 | @item QTFrame:outside:@var{start}:@var{end} | |
23217 | Like @samp{QTFrame:range:@var{start}:@var{end}}, but select the first | |
23218 | frame @emph{outside} the given range of addresses. | |
23219 | ||
23220 | @item QTStart | |
23221 | Begin the tracepoint experiment. Begin collecting data from tracepoint | |
23222 | hits in the trace frame buffer. | |
23223 | ||
23224 | @item QTStop | |
23225 | End the tracepoint experiment. Stop collecting trace frames. | |
23226 | ||
23227 | @item QTinit | |
23228 | Clear the table of tracepoints, and empty the trace frame buffer. | |
23229 | ||
23230 | @item QTro:@var{start1},@var{end1}:@var{start2},@var{end2}:@dots{} | |
23231 | Establish the given ranges of memory as ``transparent''. The stub | |
23232 | will answer requests for these ranges from memory's current contents, | |
23233 | if they were not collected as part of the tracepoint hit. | |
23234 | ||
23235 | @value{GDBN} uses this to mark read-only regions of memory, like those | |
23236 | containing program code. Since these areas never change, they should | |
23237 | still have the same contents they did when the tracepoint was hit, so | |
23238 | there's no reason for the stub to refuse to provide their contents. | |
23239 | ||
23240 | @item qTStatus | |
23241 | Ask the stub if there is a trace experiment running right now. | |
23242 | ||
23243 | Replies: | |
23244 | @table @samp | |
23245 | @item T0 | |
23246 | There is no trace experiment running. | |
23247 | @item T1 | |
23248 | There is a trace experiment running. | |
23249 | @end table | |
23250 | ||
23251 | @end table | |
23252 | ||
23253 | ||
9a6253be KB |
23254 | @node Interrupts |
23255 | @section Interrupts | |
23256 | @cindex interrupts (remote protocol) | |
23257 | ||
23258 | When a program on the remote target is running, @value{GDBN} may | |
23259 | attempt to interrupt it by sending a @samp{Ctrl-C} or a @code{BREAK}, | |
23260 | control of which is specified via @value{GDBN}'s @samp{remotebreak} | |
23261 | setting (@pxref{set remotebreak}). | |
23262 | ||
23263 | The precise meaning of @code{BREAK} is defined by the transport | |
23264 | mechanism and may, in fact, be undefined. @value{GDBN} does | |
23265 | not currently define a @code{BREAK} mechanism for any of the network | |
23266 | interfaces. | |
23267 | ||
23268 | @samp{Ctrl-C}, on the other hand, is defined and implemented for all | |
23269 | transport mechanisms. It is represented by sending the single byte | |
23270 | @code{0x03} without any of the usual packet overhead described in | |
23271 | the Overview section (@pxref{Overview}). When a @code{0x03} byte is | |
23272 | transmitted as part of a packet, it is considered to be packet data | |
23273 | and does @emph{not} represent an interrupt. E.g., an @samp{X} packet | |
23274 | (@pxref{X packet}, used for binary downloads, may include an unescaped | |
23275 | @code{0x03} as part of its packet. | |
23276 | ||
23277 | Stubs are not required to recognize these interrupt mechanisms and the | |
23278 | precise meaning associated with receipt of the interrupt is | |
23279 | implementation defined. If the stub is successful at interrupting the | |
23280 | running program, it is expected that it will send one of the Stop | |
23281 | Reply Packets (@pxref{Stop Reply Packets}) to @value{GDBN} as a result | |
23282 | of successfully stopping the program. Interrupts received while the | |
23283 | program is stopped will be discarded. | |
23284 | ||
ee2d5c50 AC |
23285 | @node Examples |
23286 | @section Examples | |
eb12ee30 | 23287 | |
8e04817f AC |
23288 | Example sequence of a target being re-started. Notice how the restart |
23289 | does not get any direct output: | |
eb12ee30 | 23290 | |
474c8240 | 23291 | @smallexample |
d2c6833e AC |
23292 | -> @code{R00} |
23293 | <- @code{+} | |
8e04817f | 23294 | @emph{target restarts} |
d2c6833e | 23295 | -> @code{?} |
8e04817f | 23296 | <- @code{+} |
d2c6833e AC |
23297 | <- @code{T001:1234123412341234} |
23298 | -> @code{+} | |
474c8240 | 23299 | @end smallexample |
eb12ee30 | 23300 | |
8e04817f | 23301 | Example sequence of a target being stepped by a single instruction: |
eb12ee30 | 23302 | |
474c8240 | 23303 | @smallexample |
d2c6833e | 23304 | -> @code{G1445@dots{}} |
8e04817f | 23305 | <- @code{+} |
d2c6833e AC |
23306 | -> @code{s} |
23307 | <- @code{+} | |
23308 | @emph{time passes} | |
23309 | <- @code{T001:1234123412341234} | |
8e04817f | 23310 | -> @code{+} |
d2c6833e | 23311 | -> @code{g} |
8e04817f | 23312 | <- @code{+} |
d2c6833e AC |
23313 | <- @code{1455@dots{}} |
23314 | -> @code{+} | |
474c8240 | 23315 | @end smallexample |
eb12ee30 | 23316 | |
0ce1b118 CV |
23317 | @node File-I/O remote protocol extension |
23318 | @section File-I/O remote protocol extension | |
23319 | @cindex File-I/O remote protocol extension | |
23320 | ||
23321 | @menu | |
23322 | * File-I/O Overview:: | |
23323 | * Protocol basics:: | |
1d8b2f28 JB |
23324 | * The F request packet:: |
23325 | * The F reply packet:: | |
0ce1b118 CV |
23326 | * Memory transfer:: |
23327 | * The Ctrl-C message:: | |
23328 | * Console I/O:: | |
23329 | * The isatty call:: | |
23330 | * The system call:: | |
23331 | * List of supported calls:: | |
23332 | * Protocol specific representation of datatypes:: | |
23333 | * Constants:: | |
23334 | * File-I/O Examples:: | |
23335 | @end menu | |
23336 | ||
23337 | @node File-I/O Overview | |
23338 | @subsection File-I/O Overview | |
23339 | @cindex file-i/o overview | |
23340 | ||
9c16f35a EZ |
23341 | The @dfn{File I/O remote protocol extension} (short: File-I/O) allows the |
23342 | target to use the host's file system and console I/O when calling various | |
0ce1b118 CV |
23343 | system calls. System calls on the target system are translated into a |
23344 | remote protocol packet to the host system which then performs the needed | |
23345 | actions and returns with an adequate response packet to the target system. | |
23346 | This simulates file system operations even on targets that lack file systems. | |
23347 | ||
23348 | The protocol is defined host- and target-system independent. It uses | |
9c16f35a | 23349 | its own independent representation of datatypes and values. Both, |
0ce1b118 CV |
23350 | @value{GDBN} and the target's @value{GDBN} stub are responsible for |
23351 | translating the system dependent values into the unified protocol values | |
23352 | when data is transmitted. | |
23353 | ||
23354 | The communication is synchronous. A system call is possible only | |
23355 | when GDB is waiting for the @samp{C}, @samp{c}, @samp{S} or @samp{s} | |
23356 | packets. While @value{GDBN} handles the request for a system call, | |
23357 | the target is stopped to allow deterministic access to the target's | |
23358 | memory. Therefore File-I/O is not interuptible by target signals. It | |
23359 | is possible to interrupt File-I/O by a user interrupt (Ctrl-C), though. | |
23360 | ||
23361 | The target's request to perform a host system call does not finish | |
23362 | the latest @samp{C}, @samp{c}, @samp{S} or @samp{s} action. That means, | |
23363 | after finishing the system call, the target returns to continuing the | |
23364 | previous activity (continue, step). No additional continue or step | |
23365 | request from @value{GDBN} is required. | |
23366 | ||
23367 | @smallexample | |
f7dc1244 | 23368 | (@value{GDBP}) continue |
0ce1b118 CV |
23369 | <- target requests 'system call X' |
23370 | target is stopped, @value{GDBN} executes system call | |
23371 | -> GDB returns result | |
23372 | ... target continues, GDB returns to wait for the target | |
23373 | <- target hits breakpoint and sends a Txx packet | |
23374 | @end smallexample | |
23375 | ||
23376 | The protocol is only used for files on the host file system and | |
23377 | for I/O on the console. Character or block special devices, pipes, | |
23378 | named pipes or sockets or any other communication method on the host | |
23379 | system are not supported by this protocol. | |
23380 | ||
23381 | @node Protocol basics | |
23382 | @subsection Protocol basics | |
23383 | @cindex protocol basics, file-i/o | |
23384 | ||
23385 | The File-I/O protocol uses the @code{F} packet, as request as well | |
23386 | as as reply packet. Since a File-I/O system call can only occur when | |
b383017d | 23387 | @value{GDBN} is waiting for the continuing or stepping target, the |
0ce1b118 CV |
23388 | File-I/O request is a reply that @value{GDBN} has to expect as a result |
23389 | of a former @samp{C}, @samp{c}, @samp{S} or @samp{s} packet. | |
23390 | This @code{F} packet contains all information needed to allow @value{GDBN} | |
23391 | to call the appropriate host system call: | |
23392 | ||
23393 | @itemize @bullet | |
b383017d | 23394 | @item |
0ce1b118 CV |
23395 | A unique identifier for the requested system call. |
23396 | ||
23397 | @item | |
23398 | All parameters to the system call. Pointers are given as addresses | |
23399 | in the target memory address space. Pointers to strings are given as | |
b383017d | 23400 | pointer/length pair. Numerical values are given as they are. |
0ce1b118 CV |
23401 | Numerical control values are given in a protocol specific representation. |
23402 | ||
23403 | @end itemize | |
23404 | ||
23405 | At that point @value{GDBN} has to perform the following actions. | |
23406 | ||
23407 | @itemize @bullet | |
b383017d | 23408 | @item |
0ce1b118 CV |
23409 | If parameter pointer values are given, which point to data needed as input |
23410 | to a system call, @value{GDBN} requests this data from the target with a | |
23411 | standard @code{m} packet request. This additional communication has to be | |
23412 | expected by the target implementation and is handled as any other @code{m} | |
23413 | packet. | |
23414 | ||
23415 | @item | |
23416 | @value{GDBN} translates all value from protocol representation to host | |
23417 | representation as needed. Datatypes are coerced into the host types. | |
23418 | ||
23419 | @item | |
23420 | @value{GDBN} calls the system call | |
23421 | ||
23422 | @item | |
23423 | It then coerces datatypes back to protocol representation. | |
23424 | ||
23425 | @item | |
23426 | If pointer parameters in the request packet point to buffer space in which | |
23427 | a system call is expected to copy data to, the data is transmitted to the | |
23428 | target using a @code{M} or @code{X} packet. This packet has to be expected | |
23429 | by the target implementation and is handled as any other @code{M} or @code{X} | |
23430 | packet. | |
23431 | ||
23432 | @end itemize | |
23433 | ||
23434 | Eventually @value{GDBN} replies with another @code{F} packet which contains all | |
23435 | necessary information for the target to continue. This at least contains | |
23436 | ||
23437 | @itemize @bullet | |
23438 | @item | |
23439 | Return value. | |
23440 | ||
23441 | @item | |
23442 | @code{errno}, if has been changed by the system call. | |
23443 | ||
23444 | @item | |
23445 | ``Ctrl-C'' flag. | |
23446 | ||
23447 | @end itemize | |
23448 | ||
23449 | After having done the needed type and value coercion, the target continues | |
23450 | the latest continue or step action. | |
23451 | ||
1d8b2f28 | 23452 | @node The F request packet |
0ce1b118 CV |
23453 | @subsection The @code{F} request packet |
23454 | @cindex file-i/o request packet | |
23455 | @cindex @code{F} request packet | |
23456 | ||
23457 | The @code{F} request packet has the following format: | |
23458 | ||
23459 | @table @samp | |
23460 | ||
23461 | @smallexample | |
23462 | @code{F}@var{call-id}@code{,}@var{parameter@dots{}} | |
23463 | @end smallexample | |
23464 | ||
23465 | @var{call-id} is the identifier to indicate the host system call to be called. | |
23466 | This is just the name of the function. | |
23467 | ||
23468 | @var{parameter@dots{}} are the parameters to the system call. | |
23469 | ||
b383017d | 23470 | @end table |
0ce1b118 CV |
23471 | |
23472 | Parameters are hexadecimal integer values, either the real values in case | |
23473 | of scalar datatypes, as pointers to target buffer space in case of compound | |
23474 | datatypes and unspecified memory areas or as pointer/length pairs in case | |
23475 | of string parameters. These are appended to the call-id, each separated | |
23476 | from its predecessor by a comma. All values are transmitted in ASCII | |
23477 | string representation, pointer/length pairs separated by a slash. | |
23478 | ||
1d8b2f28 | 23479 | @node The F reply packet |
0ce1b118 CV |
23480 | @subsection The @code{F} reply packet |
23481 | @cindex file-i/o reply packet | |
23482 | @cindex @code{F} reply packet | |
23483 | ||
23484 | The @code{F} reply packet has the following format: | |
23485 | ||
23486 | @table @samp | |
23487 | ||
23488 | @smallexample | |
23489 | @code{F}@var{retcode}@code{,}@var{errno}@code{,}@var{Ctrl-C flag}@code{;}@var{call specific attachment} | |
23490 | @end smallexample | |
23491 | ||
23492 | @var{retcode} is the return code of the system call as hexadecimal value. | |
23493 | ||
23494 | @var{errno} is the errno set by the call, in protocol specific representation. | |
23495 | This parameter can be omitted if the call was successful. | |
23496 | ||
23497 | @var{Ctrl-C flag} is only send if the user requested a break. In this | |
23498 | case, @var{errno} must be send as well, even if the call was successful. | |
23499 | The @var{Ctrl-C flag} itself consists of the character 'C': | |
23500 | ||
23501 | @smallexample | |
23502 | F0,0,C | |
23503 | @end smallexample | |
23504 | ||
23505 | @noindent | |
23506 | or, if the call was interupted before the host call has been performed: | |
23507 | ||
23508 | @smallexample | |
23509 | F-1,4,C | |
23510 | @end smallexample | |
23511 | ||
23512 | @noindent | |
23513 | assuming 4 is the protocol specific representation of @code{EINTR}. | |
23514 | ||
23515 | @end table | |
23516 | ||
23517 | @node Memory transfer | |
23518 | @subsection Memory transfer | |
23519 | @cindex memory transfer, in file-i/o protocol | |
23520 | ||
23521 | Structured data which is transferred using a memory read or write as e.g.@: | |
23522 | a @code{struct stat} is expected to be in a protocol specific format with | |
23523 | all scalar multibyte datatypes being big endian. This should be done by | |
23524 | the target before the @code{F} packet is sent resp.@: by @value{GDBN} before | |
23525 | it transfers memory to the target. Transferred pointers to structured | |
23526 | data should point to the already coerced data at any time. | |
23527 | ||
23528 | @node The Ctrl-C message | |
23529 | @subsection The Ctrl-C message | |
23530 | @cindex ctrl-c message, in file-i/o protocol | |
23531 | ||
23532 | A special case is, if the @var{Ctrl-C flag} is set in the @value{GDBN} | |
23533 | reply packet. In this case the target should behave, as if it had | |
23534 | gotten a break message. The meaning for the target is ``system call | |
23535 | interupted by @code{SIGINT}''. Consequentially, the target should actually stop | |
23536 | (as with a break message) and return to @value{GDBN} with a @code{T02} | |
b383017d | 23537 | packet. In this case, it's important for the target to know, in which |
0ce1b118 CV |
23538 | state the system call was interrupted. Since this action is by design |
23539 | not an atomic operation, we have to differ between two cases: | |
23540 | ||
23541 | @itemize @bullet | |
23542 | @item | |
23543 | The system call hasn't been performed on the host yet. | |
23544 | ||
23545 | @item | |
23546 | The system call on the host has been finished. | |
23547 | ||
23548 | @end itemize | |
23549 | ||
23550 | These two states can be distinguished by the target by the value of the | |
23551 | returned @code{errno}. If it's the protocol representation of @code{EINTR}, the system | |
23552 | call hasn't been performed. This is equivalent to the @code{EINTR} handling | |
23553 | on POSIX systems. In any other case, the target may presume that the | |
23554 | system call has been finished --- successful or not --- and should behave | |
23555 | as if the break message arrived right after the system call. | |
23556 | ||
23557 | @value{GDBN} must behave reliable. If the system call has not been called | |
23558 | yet, @value{GDBN} may send the @code{F} reply immediately, setting @code{EINTR} as | |
23559 | @code{errno} in the packet. If the system call on the host has been finished | |
23560 | before the user requests a break, the full action must be finshed by | |
23561 | @value{GDBN}. This requires sending @code{M} or @code{X} packets as they fit. | |
23562 | The @code{F} packet may only be send when either nothing has happened | |
23563 | or the full action has been completed. | |
23564 | ||
23565 | @node Console I/O | |
23566 | @subsection Console I/O | |
23567 | @cindex console i/o as part of file-i/o | |
23568 | ||
23569 | By default and if not explicitely closed by the target system, the file | |
23570 | descriptors 0, 1 and 2 are connected to the @value{GDBN} console. Output | |
23571 | on the @value{GDBN} console is handled as any other file output operation | |
23572 | (@code{write(1, @dots{})} or @code{write(2, @dots{})}). Console input is handled | |
23573 | by @value{GDBN} so that after the target read request from file descriptor | |
23574 | 0 all following typing is buffered until either one of the following | |
23575 | conditions is met: | |
23576 | ||
23577 | @itemize @bullet | |
23578 | @item | |
23579 | The user presses @kbd{Ctrl-C}. The behaviour is as explained above, the | |
23580 | @code{read} | |
23581 | system call is treated as finished. | |
23582 | ||
23583 | @item | |
23584 | The user presses @kbd{Enter}. This is treated as end of input with a trailing | |
23585 | line feed. | |
23586 | ||
23587 | @item | |
23588 | The user presses @kbd{Ctrl-D}. This is treated as end of input. No trailing | |
23589 | character, especially no Ctrl-D is appended to the input. | |
23590 | ||
23591 | @end itemize | |
23592 | ||
23593 | If the user has typed more characters as fit in the buffer given to | |
23594 | the read call, the trailing characters are buffered in @value{GDBN} until | |
23595 | either another @code{read(0, @dots{})} is requested by the target or debugging | |
23596 | is stopped on users request. | |
23597 | ||
23598 | @node The isatty call | |
2eecc4ab | 23599 | @subsection The @samp{isatty} function call |
0ce1b118 CV |
23600 | @cindex isatty call, file-i/o protocol |
23601 | ||
23602 | A special case in this protocol is the library call @code{isatty} which | |
9c16f35a | 23603 | is implemented as its own call inside of this protocol. It returns |
0ce1b118 CV |
23604 | 1 to the target if the file descriptor given as parameter is attached |
23605 | to the @value{GDBN} console, 0 otherwise. Implementing through system calls | |
23606 | would require implementing @code{ioctl} and would be more complex than | |
23607 | needed. | |
23608 | ||
23609 | @node The system call | |
2eecc4ab | 23610 | @subsection The @samp{system} function call |
0ce1b118 CV |
23611 | @cindex system call, file-i/o protocol |
23612 | ||
23613 | The other special case in this protocol is the @code{system} call which | |
9c16f35a | 23614 | is implemented as its own call, too. @value{GDBN} is taking over the full |
0ce1b118 CV |
23615 | task of calling the necessary host calls to perform the @code{system} |
23616 | call. The return value of @code{system} is simplified before it's returned | |
23617 | to the target. Basically, the only signal transmitted back is @code{EINTR} | |
23618 | in case the user pressed @kbd{Ctrl-C}. Otherwise the return value consists | |
23619 | entirely of the exit status of the called command. | |
23620 | ||
9c16f35a EZ |
23621 | Due to security concerns, the @code{system} call is by default refused |
23622 | by @value{GDBN}. The user has to allow this call explicitly with the | |
23623 | @kbd{set remote system-call-allowed 1} command. | |
0ce1b118 | 23624 | |
9c16f35a EZ |
23625 | @table @code |
23626 | @item set remote system-call-allowed | |
23627 | @kindex set remote system-call-allowed | |
23628 | Control whether to allow the @code{system} calls in the File I/O | |
23629 | protocol for the remote target. The default is zero (disabled). | |
0ce1b118 | 23630 | |
9c16f35a | 23631 | @item show remote system-call-allowed |
0ce1b118 | 23632 | @kindex show remote system-call-allowed |
9c16f35a EZ |
23633 | Show the current setting of system calls for the remote File I/O |
23634 | protocol. | |
0ce1b118 CV |
23635 | @end table |
23636 | ||
23637 | @node List of supported calls | |
23638 | @subsection List of supported calls | |
23639 | @cindex list of supported file-i/o calls | |
23640 | ||
23641 | @menu | |
23642 | * open:: | |
23643 | * close:: | |
23644 | * read:: | |
23645 | * write:: | |
23646 | * lseek:: | |
23647 | * rename:: | |
23648 | * unlink:: | |
23649 | * stat/fstat:: | |
23650 | * gettimeofday:: | |
23651 | * isatty:: | |
23652 | * system:: | |
23653 | @end menu | |
23654 | ||
23655 | @node open | |
23656 | @unnumberedsubsubsec open | |
23657 | @cindex open, file-i/o system call | |
23658 | ||
23659 | @smallexample | |
23660 | @exdent Synopsis: | |
23661 | int open(const char *pathname, int flags); | |
23662 | int open(const char *pathname, int flags, mode_t mode); | |
23663 | ||
b383017d | 23664 | @exdent Request: |
0ce1b118 CV |
23665 | Fopen,pathptr/len,flags,mode |
23666 | @end smallexample | |
23667 | ||
23668 | @noindent | |
23669 | @code{flags} is the bitwise or of the following values: | |
23670 | ||
23671 | @table @code | |
b383017d | 23672 | @item O_CREAT |
0ce1b118 CV |
23673 | If the file does not exist it will be created. The host |
23674 | rules apply as far as file ownership and time stamps | |
23675 | are concerned. | |
23676 | ||
b383017d | 23677 | @item O_EXCL |
0ce1b118 CV |
23678 | When used with O_CREAT, if the file already exists it is |
23679 | an error and open() fails. | |
23680 | ||
b383017d | 23681 | @item O_TRUNC |
0ce1b118 CV |
23682 | If the file already exists and the open mode allows |
23683 | writing (O_RDWR or O_WRONLY is given) it will be | |
23684 | truncated to length 0. | |
23685 | ||
b383017d | 23686 | @item O_APPEND |
0ce1b118 CV |
23687 | The file is opened in append mode. |
23688 | ||
b383017d | 23689 | @item O_RDONLY |
0ce1b118 CV |
23690 | The file is opened for reading only. |
23691 | ||
b383017d | 23692 | @item O_WRONLY |
0ce1b118 CV |
23693 | The file is opened for writing only. |
23694 | ||
b383017d | 23695 | @item O_RDWR |
0ce1b118 CV |
23696 | The file is opened for reading and writing. |
23697 | ||
23698 | @noindent | |
23699 | Each other bit is silently ignored. | |
23700 | ||
23701 | @end table | |
23702 | ||
23703 | @noindent | |
23704 | @code{mode} is the bitwise or of the following values: | |
23705 | ||
23706 | @table @code | |
b383017d | 23707 | @item S_IRUSR |
0ce1b118 CV |
23708 | User has read permission. |
23709 | ||
b383017d | 23710 | @item S_IWUSR |
0ce1b118 CV |
23711 | User has write permission. |
23712 | ||
b383017d | 23713 | @item S_IRGRP |
0ce1b118 CV |
23714 | Group has read permission. |
23715 | ||
b383017d | 23716 | @item S_IWGRP |
0ce1b118 CV |
23717 | Group has write permission. |
23718 | ||
b383017d | 23719 | @item S_IROTH |
0ce1b118 CV |
23720 | Others have read permission. |
23721 | ||
b383017d | 23722 | @item S_IWOTH |
0ce1b118 CV |
23723 | Others have write permission. |
23724 | ||
23725 | @noindent | |
23726 | Each other bit is silently ignored. | |
23727 | ||
23728 | @end table | |
23729 | ||
23730 | @smallexample | |
23731 | @exdent Return value: | |
23732 | open returns the new file descriptor or -1 if an error | |
23733 | occured. | |
23734 | ||
23735 | @exdent Errors: | |
23736 | @end smallexample | |
23737 | ||
23738 | @table @code | |
b383017d | 23739 | @item EEXIST |
0ce1b118 CV |
23740 | pathname already exists and O_CREAT and O_EXCL were used. |
23741 | ||
b383017d | 23742 | @item EISDIR |
0ce1b118 CV |
23743 | pathname refers to a directory. |
23744 | ||
b383017d | 23745 | @item EACCES |
0ce1b118 CV |
23746 | The requested access is not allowed. |
23747 | ||
23748 | @item ENAMETOOLONG | |
23749 | pathname was too long. | |
23750 | ||
b383017d | 23751 | @item ENOENT |
0ce1b118 CV |
23752 | A directory component in pathname does not exist. |
23753 | ||
b383017d | 23754 | @item ENODEV |
0ce1b118 CV |
23755 | pathname refers to a device, pipe, named pipe or socket. |
23756 | ||
b383017d | 23757 | @item EROFS |
0ce1b118 CV |
23758 | pathname refers to a file on a read-only filesystem and |
23759 | write access was requested. | |
23760 | ||
b383017d | 23761 | @item EFAULT |
0ce1b118 CV |
23762 | pathname is an invalid pointer value. |
23763 | ||
b383017d | 23764 | @item ENOSPC |
0ce1b118 CV |
23765 | No space on device to create the file. |
23766 | ||
b383017d | 23767 | @item EMFILE |
0ce1b118 CV |
23768 | The process already has the maximum number of files open. |
23769 | ||
b383017d | 23770 | @item ENFILE |
0ce1b118 CV |
23771 | The limit on the total number of files open on the system |
23772 | has been reached. | |
23773 | ||
b383017d | 23774 | @item EINTR |
0ce1b118 CV |
23775 | The call was interrupted by the user. |
23776 | @end table | |
23777 | ||
23778 | @node close | |
23779 | @unnumberedsubsubsec close | |
23780 | @cindex close, file-i/o system call | |
23781 | ||
23782 | @smallexample | |
b383017d | 23783 | @exdent Synopsis: |
0ce1b118 CV |
23784 | int close(int fd); |
23785 | ||
b383017d | 23786 | @exdent Request: |
0ce1b118 CV |
23787 | Fclose,fd |
23788 | ||
23789 | @exdent Return value: | |
23790 | close returns zero on success, or -1 if an error occurred. | |
23791 | ||
23792 | @exdent Errors: | |
23793 | @end smallexample | |
23794 | ||
23795 | @table @code | |
b383017d | 23796 | @item EBADF |
0ce1b118 CV |
23797 | fd isn't a valid open file descriptor. |
23798 | ||
b383017d | 23799 | @item EINTR |
0ce1b118 CV |
23800 | The call was interrupted by the user. |
23801 | @end table | |
23802 | ||
23803 | @node read | |
23804 | @unnumberedsubsubsec read | |
23805 | @cindex read, file-i/o system call | |
23806 | ||
23807 | @smallexample | |
b383017d | 23808 | @exdent Synopsis: |
0ce1b118 CV |
23809 | int read(int fd, void *buf, unsigned int count); |
23810 | ||
b383017d | 23811 | @exdent Request: |
0ce1b118 CV |
23812 | Fread,fd,bufptr,count |
23813 | ||
23814 | @exdent Return value: | |
23815 | On success, the number of bytes read is returned. | |
23816 | Zero indicates end of file. If count is zero, read | |
b383017d | 23817 | returns zero as well. On error, -1 is returned. |
0ce1b118 CV |
23818 | |
23819 | @exdent Errors: | |
23820 | @end smallexample | |
23821 | ||
23822 | @table @code | |
b383017d | 23823 | @item EBADF |
0ce1b118 CV |
23824 | fd is not a valid file descriptor or is not open for |
23825 | reading. | |
23826 | ||
b383017d | 23827 | @item EFAULT |
0ce1b118 CV |
23828 | buf is an invalid pointer value. |
23829 | ||
b383017d | 23830 | @item EINTR |
0ce1b118 CV |
23831 | The call was interrupted by the user. |
23832 | @end table | |
23833 | ||
23834 | @node write | |
23835 | @unnumberedsubsubsec write | |
23836 | @cindex write, file-i/o system call | |
23837 | ||
23838 | @smallexample | |
b383017d | 23839 | @exdent Synopsis: |
0ce1b118 CV |
23840 | int write(int fd, const void *buf, unsigned int count); |
23841 | ||
b383017d | 23842 | @exdent Request: |
0ce1b118 CV |
23843 | Fwrite,fd,bufptr,count |
23844 | ||
23845 | @exdent Return value: | |
23846 | On success, the number of bytes written are returned. | |
23847 | Zero indicates nothing was written. On error, -1 | |
23848 | is returned. | |
23849 | ||
23850 | @exdent Errors: | |
23851 | @end smallexample | |
23852 | ||
23853 | @table @code | |
b383017d | 23854 | @item EBADF |
0ce1b118 CV |
23855 | fd is not a valid file descriptor or is not open for |
23856 | writing. | |
23857 | ||
b383017d | 23858 | @item EFAULT |
0ce1b118 CV |
23859 | buf is an invalid pointer value. |
23860 | ||
b383017d | 23861 | @item EFBIG |
0ce1b118 CV |
23862 | An attempt was made to write a file that exceeds the |
23863 | host specific maximum file size allowed. | |
23864 | ||
b383017d | 23865 | @item ENOSPC |
0ce1b118 CV |
23866 | No space on device to write the data. |
23867 | ||
b383017d | 23868 | @item EINTR |
0ce1b118 CV |
23869 | The call was interrupted by the user. |
23870 | @end table | |
23871 | ||
23872 | @node lseek | |
23873 | @unnumberedsubsubsec lseek | |
23874 | @cindex lseek, file-i/o system call | |
23875 | ||
23876 | @smallexample | |
b383017d | 23877 | @exdent Synopsis: |
0ce1b118 CV |
23878 | long lseek (int fd, long offset, int flag); |
23879 | ||
b383017d | 23880 | @exdent Request: |
0ce1b118 CV |
23881 | Flseek,fd,offset,flag |
23882 | @end smallexample | |
23883 | ||
23884 | @code{flag} is one of: | |
23885 | ||
23886 | @table @code | |
b383017d | 23887 | @item SEEK_SET |
0ce1b118 CV |
23888 | The offset is set to offset bytes. |
23889 | ||
b383017d | 23890 | @item SEEK_CUR |
0ce1b118 CV |
23891 | The offset is set to its current location plus offset |
23892 | bytes. | |
23893 | ||
b383017d | 23894 | @item SEEK_END |
0ce1b118 CV |
23895 | The offset is set to the size of the file plus offset |
23896 | bytes. | |
23897 | @end table | |
23898 | ||
23899 | @smallexample | |
23900 | @exdent Return value: | |
23901 | On success, the resulting unsigned offset in bytes from | |
23902 | the beginning of the file is returned. Otherwise, a | |
23903 | value of -1 is returned. | |
23904 | ||
23905 | @exdent Errors: | |
23906 | @end smallexample | |
23907 | ||
23908 | @table @code | |
b383017d | 23909 | @item EBADF |
0ce1b118 CV |
23910 | fd is not a valid open file descriptor. |
23911 | ||
b383017d | 23912 | @item ESPIPE |
0ce1b118 CV |
23913 | fd is associated with the @value{GDBN} console. |
23914 | ||
b383017d | 23915 | @item EINVAL |
0ce1b118 CV |
23916 | flag is not a proper value. |
23917 | ||
b383017d | 23918 | @item EINTR |
0ce1b118 CV |
23919 | The call was interrupted by the user. |
23920 | @end table | |
23921 | ||
23922 | @node rename | |
23923 | @unnumberedsubsubsec rename | |
23924 | @cindex rename, file-i/o system call | |
23925 | ||
23926 | @smallexample | |
b383017d | 23927 | @exdent Synopsis: |
0ce1b118 CV |
23928 | int rename(const char *oldpath, const char *newpath); |
23929 | ||
b383017d | 23930 | @exdent Request: |
0ce1b118 CV |
23931 | Frename,oldpathptr/len,newpathptr/len |
23932 | ||
23933 | @exdent Return value: | |
23934 | On success, zero is returned. On error, -1 is returned. | |
23935 | ||
23936 | @exdent Errors: | |
23937 | @end smallexample | |
23938 | ||
23939 | @table @code | |
b383017d | 23940 | @item EISDIR |
0ce1b118 CV |
23941 | newpath is an existing directory, but oldpath is not a |
23942 | directory. | |
23943 | ||
b383017d | 23944 | @item EEXIST |
0ce1b118 CV |
23945 | newpath is a non-empty directory. |
23946 | ||
b383017d | 23947 | @item EBUSY |
0ce1b118 CV |
23948 | oldpath or newpath is a directory that is in use by some |
23949 | process. | |
23950 | ||
b383017d | 23951 | @item EINVAL |
0ce1b118 CV |
23952 | An attempt was made to make a directory a subdirectory |
23953 | of itself. | |
23954 | ||
b383017d | 23955 | @item ENOTDIR |
0ce1b118 CV |
23956 | A component used as a directory in oldpath or new |
23957 | path is not a directory. Or oldpath is a directory | |
23958 | and newpath exists but is not a directory. | |
23959 | ||
b383017d | 23960 | @item EFAULT |
0ce1b118 CV |
23961 | oldpathptr or newpathptr are invalid pointer values. |
23962 | ||
b383017d | 23963 | @item EACCES |
0ce1b118 CV |
23964 | No access to the file or the path of the file. |
23965 | ||
23966 | @item ENAMETOOLONG | |
b383017d | 23967 | |
0ce1b118 CV |
23968 | oldpath or newpath was too long. |
23969 | ||
b383017d | 23970 | @item ENOENT |
0ce1b118 CV |
23971 | A directory component in oldpath or newpath does not exist. |
23972 | ||
b383017d | 23973 | @item EROFS |
0ce1b118 CV |
23974 | The file is on a read-only filesystem. |
23975 | ||
b383017d | 23976 | @item ENOSPC |
0ce1b118 CV |
23977 | The device containing the file has no room for the new |
23978 | directory entry. | |
23979 | ||
b383017d | 23980 | @item EINTR |
0ce1b118 CV |
23981 | The call was interrupted by the user. |
23982 | @end table | |
23983 | ||
23984 | @node unlink | |
23985 | @unnumberedsubsubsec unlink | |
23986 | @cindex unlink, file-i/o system call | |
23987 | ||
23988 | @smallexample | |
b383017d | 23989 | @exdent Synopsis: |
0ce1b118 CV |
23990 | int unlink(const char *pathname); |
23991 | ||
b383017d | 23992 | @exdent Request: |
0ce1b118 CV |
23993 | Funlink,pathnameptr/len |
23994 | ||
23995 | @exdent Return value: | |
23996 | On success, zero is returned. On error, -1 is returned. | |
23997 | ||
23998 | @exdent Errors: | |
23999 | @end smallexample | |
24000 | ||
24001 | @table @code | |
b383017d | 24002 | @item EACCES |
0ce1b118 CV |
24003 | No access to the file or the path of the file. |
24004 | ||
b383017d | 24005 | @item EPERM |
0ce1b118 CV |
24006 | The system does not allow unlinking of directories. |
24007 | ||
b383017d | 24008 | @item EBUSY |
0ce1b118 CV |
24009 | The file pathname cannot be unlinked because it's |
24010 | being used by another process. | |
24011 | ||
b383017d | 24012 | @item EFAULT |
0ce1b118 CV |
24013 | pathnameptr is an invalid pointer value. |
24014 | ||
24015 | @item ENAMETOOLONG | |
24016 | pathname was too long. | |
24017 | ||
b383017d | 24018 | @item ENOENT |
0ce1b118 CV |
24019 | A directory component in pathname does not exist. |
24020 | ||
b383017d | 24021 | @item ENOTDIR |
0ce1b118 CV |
24022 | A component of the path is not a directory. |
24023 | ||
b383017d | 24024 | @item EROFS |
0ce1b118 CV |
24025 | The file is on a read-only filesystem. |
24026 | ||
b383017d | 24027 | @item EINTR |
0ce1b118 CV |
24028 | The call was interrupted by the user. |
24029 | @end table | |
24030 | ||
24031 | @node stat/fstat | |
24032 | @unnumberedsubsubsec stat/fstat | |
24033 | @cindex fstat, file-i/o system call | |
24034 | @cindex stat, file-i/o system call | |
24035 | ||
24036 | @smallexample | |
b383017d | 24037 | @exdent Synopsis: |
0ce1b118 CV |
24038 | int stat(const char *pathname, struct stat *buf); |
24039 | int fstat(int fd, struct stat *buf); | |
24040 | ||
b383017d | 24041 | @exdent Request: |
0ce1b118 CV |
24042 | Fstat,pathnameptr/len,bufptr |
24043 | Ffstat,fd,bufptr | |
24044 | ||
24045 | @exdent Return value: | |
24046 | On success, zero is returned. On error, -1 is returned. | |
24047 | ||
24048 | @exdent Errors: | |
24049 | @end smallexample | |
24050 | ||
24051 | @table @code | |
b383017d | 24052 | @item EBADF |
0ce1b118 CV |
24053 | fd is not a valid open file. |
24054 | ||
b383017d | 24055 | @item ENOENT |
0ce1b118 CV |
24056 | A directory component in pathname does not exist or the |
24057 | path is an empty string. | |
24058 | ||
b383017d | 24059 | @item ENOTDIR |
0ce1b118 CV |
24060 | A component of the path is not a directory. |
24061 | ||
b383017d | 24062 | @item EFAULT |
0ce1b118 CV |
24063 | pathnameptr is an invalid pointer value. |
24064 | ||
b383017d | 24065 | @item EACCES |
0ce1b118 CV |
24066 | No access to the file or the path of the file. |
24067 | ||
24068 | @item ENAMETOOLONG | |
24069 | pathname was too long. | |
24070 | ||
b383017d | 24071 | @item EINTR |
0ce1b118 CV |
24072 | The call was interrupted by the user. |
24073 | @end table | |
24074 | ||
24075 | @node gettimeofday | |
24076 | @unnumberedsubsubsec gettimeofday | |
24077 | @cindex gettimeofday, file-i/o system call | |
24078 | ||
24079 | @smallexample | |
b383017d | 24080 | @exdent Synopsis: |
0ce1b118 CV |
24081 | int gettimeofday(struct timeval *tv, void *tz); |
24082 | ||
b383017d | 24083 | @exdent Request: |
0ce1b118 CV |
24084 | Fgettimeofday,tvptr,tzptr |
24085 | ||
24086 | @exdent Return value: | |
24087 | On success, 0 is returned, -1 otherwise. | |
24088 | ||
24089 | @exdent Errors: | |
24090 | @end smallexample | |
24091 | ||
24092 | @table @code | |
b383017d | 24093 | @item EINVAL |
0ce1b118 CV |
24094 | tz is a non-NULL pointer. |
24095 | ||
b383017d | 24096 | @item EFAULT |
0ce1b118 CV |
24097 | tvptr and/or tzptr is an invalid pointer value. |
24098 | @end table | |
24099 | ||
24100 | @node isatty | |
24101 | @unnumberedsubsubsec isatty | |
24102 | @cindex isatty, file-i/o system call | |
24103 | ||
24104 | @smallexample | |
b383017d | 24105 | @exdent Synopsis: |
0ce1b118 CV |
24106 | int isatty(int fd); |
24107 | ||
b383017d | 24108 | @exdent Request: |
0ce1b118 CV |
24109 | Fisatty,fd |
24110 | ||
24111 | @exdent Return value: | |
24112 | Returns 1 if fd refers to the @value{GDBN} console, 0 otherwise. | |
24113 | ||
24114 | @exdent Errors: | |
24115 | @end smallexample | |
24116 | ||
24117 | @table @code | |
b383017d | 24118 | @item EINTR |
0ce1b118 CV |
24119 | The call was interrupted by the user. |
24120 | @end table | |
24121 | ||
24122 | @node system | |
24123 | @unnumberedsubsubsec system | |
24124 | @cindex system, file-i/o system call | |
24125 | ||
24126 | @smallexample | |
b383017d | 24127 | @exdent Synopsis: |
0ce1b118 CV |
24128 | int system(const char *command); |
24129 | ||
b383017d | 24130 | @exdent Request: |
0ce1b118 CV |
24131 | Fsystem,commandptr/len |
24132 | ||
24133 | @exdent Return value: | |
24134 | The value returned is -1 on error and the return status | |
24135 | of the command otherwise. Only the exit status of the | |
24136 | command is returned, which is extracted from the hosts | |
24137 | system return value by calling WEXITSTATUS(retval). | |
24138 | In case /bin/sh could not be executed, 127 is returned. | |
24139 | ||
24140 | @exdent Errors: | |
24141 | @end smallexample | |
24142 | ||
24143 | @table @code | |
b383017d | 24144 | @item EINTR |
0ce1b118 CV |
24145 | The call was interrupted by the user. |
24146 | @end table | |
24147 | ||
24148 | @node Protocol specific representation of datatypes | |
24149 | @subsection Protocol specific representation of datatypes | |
24150 | @cindex protocol specific representation of datatypes, in file-i/o protocol | |
24151 | ||
24152 | @menu | |
24153 | * Integral datatypes:: | |
24154 | * Pointer values:: | |
24155 | * struct stat:: | |
24156 | * struct timeval:: | |
24157 | @end menu | |
24158 | ||
24159 | @node Integral datatypes | |
24160 | @unnumberedsubsubsec Integral datatypes | |
24161 | @cindex integral datatypes, in file-i/o protocol | |
24162 | ||
24163 | The integral datatypes used in the system calls are | |
24164 | ||
24165 | @smallexample | |
24166 | int@r{,} unsigned int@r{,} long@r{,} unsigned long@r{,} mode_t @r{and} time_t | |
24167 | @end smallexample | |
24168 | ||
24169 | @code{Int}, @code{unsigned int}, @code{mode_t} and @code{time_t} are | |
24170 | implemented as 32 bit values in this protocol. | |
24171 | ||
b383017d RM |
24172 | @code{Long} and @code{unsigned long} are implemented as 64 bit types. |
24173 | ||
0ce1b118 CV |
24174 | @xref{Limits}, for corresponding MIN and MAX values (similar to those |
24175 | in @file{limits.h}) to allow range checking on host and target. | |
24176 | ||
24177 | @code{time_t} datatypes are defined as seconds since the Epoch. | |
24178 | ||
24179 | All integral datatypes transferred as part of a memory read or write of a | |
24180 | structured datatype e.g.@: a @code{struct stat} have to be given in big endian | |
24181 | byte order. | |
24182 | ||
24183 | @node Pointer values | |
24184 | @unnumberedsubsubsec Pointer values | |
24185 | @cindex pointer values, in file-i/o protocol | |
24186 | ||
24187 | Pointers to target data are transmitted as they are. An exception | |
24188 | is made for pointers to buffers for which the length isn't | |
24189 | transmitted as part of the function call, namely strings. Strings | |
24190 | are transmitted as a pointer/length pair, both as hex values, e.g.@: | |
24191 | ||
24192 | @smallexample | |
24193 | @code{1aaf/12} | |
24194 | @end smallexample | |
24195 | ||
24196 | @noindent | |
24197 | which is a pointer to data of length 18 bytes at position 0x1aaf. | |
24198 | The length is defined as the full string length in bytes, including | |
24199 | the trailing null byte. Example: | |
24200 | ||
24201 | @smallexample | |
24202 | ``hello, world'' at address 0x123456 | |
24203 | @end smallexample | |
24204 | ||
24205 | @noindent | |
24206 | is transmitted as | |
24207 | ||
24208 | @smallexample | |
24209 | @code{123456/d} | |
24210 | @end smallexample | |
24211 | ||
24212 | @node struct stat | |
24213 | @unnumberedsubsubsec struct stat | |
24214 | @cindex struct stat, in file-i/o protocol | |
24215 | ||
24216 | The buffer of type struct stat used by the target and @value{GDBN} is defined | |
24217 | as follows: | |
24218 | ||
24219 | @smallexample | |
24220 | struct stat @{ | |
24221 | unsigned int st_dev; /* device */ | |
24222 | unsigned int st_ino; /* inode */ | |
24223 | mode_t st_mode; /* protection */ | |
24224 | unsigned int st_nlink; /* number of hard links */ | |
24225 | unsigned int st_uid; /* user ID of owner */ | |
24226 | unsigned int st_gid; /* group ID of owner */ | |
24227 | unsigned int st_rdev; /* device type (if inode device) */ | |
24228 | unsigned long st_size; /* total size, in bytes */ | |
24229 | unsigned long st_blksize; /* blocksize for filesystem I/O */ | |
24230 | unsigned long st_blocks; /* number of blocks allocated */ | |
24231 | time_t st_atime; /* time of last access */ | |
24232 | time_t st_mtime; /* time of last modification */ | |
24233 | time_t st_ctime; /* time of last change */ | |
24234 | @}; | |
24235 | @end smallexample | |
24236 | ||
24237 | The integral datatypes are conforming to the definitions given in the | |
24238 | approriate section (see @ref{Integral datatypes}, for details) so this | |
24239 | structure is of size 64 bytes. | |
24240 | ||
24241 | The values of several fields have a restricted meaning and/or | |
24242 | range of values. | |
24243 | ||
24244 | @smallexample | |
24245 | st_dev: 0 file | |
24246 | 1 console | |
24247 | ||
24248 | st_ino: No valid meaning for the target. Transmitted unchanged. | |
24249 | ||
24250 | st_mode: Valid mode bits are described in Appendix C. Any other | |
24251 | bits have currently no meaning for the target. | |
24252 | ||
24253 | st_uid: No valid meaning for the target. Transmitted unchanged. | |
24254 | ||
24255 | st_gid: No valid meaning for the target. Transmitted unchanged. | |
24256 | ||
24257 | st_rdev: No valid meaning for the target. Transmitted unchanged. | |
24258 | ||
24259 | st_atime, st_mtime, st_ctime: | |
24260 | These values have a host and file system dependent | |
24261 | accuracy. Especially on Windows hosts the file systems | |
24262 | don't support exact timing values. | |
24263 | @end smallexample | |
24264 | ||
24265 | The target gets a struct stat of the above representation and is | |
24266 | responsible to coerce it to the target representation before | |
24267 | continuing. | |
24268 | ||
24269 | Note that due to size differences between the host and target | |
24270 | representation of stat members, these members could eventually | |
24271 | get truncated on the target. | |
24272 | ||
24273 | @node struct timeval | |
24274 | @unnumberedsubsubsec struct timeval | |
24275 | @cindex struct timeval, in file-i/o protocol | |
24276 | ||
24277 | The buffer of type struct timeval used by the target and @value{GDBN} | |
24278 | is defined as follows: | |
24279 | ||
24280 | @smallexample | |
b383017d | 24281 | struct timeval @{ |
0ce1b118 CV |
24282 | time_t tv_sec; /* second */ |
24283 | long tv_usec; /* microsecond */ | |
24284 | @}; | |
24285 | @end smallexample | |
24286 | ||
24287 | The integral datatypes are conforming to the definitions given in the | |
24288 | approriate section (see @ref{Integral datatypes}, for details) so this | |
24289 | structure is of size 8 bytes. | |
24290 | ||
24291 | @node Constants | |
24292 | @subsection Constants | |
24293 | @cindex constants, in file-i/o protocol | |
24294 | ||
24295 | The following values are used for the constants inside of the | |
24296 | protocol. @value{GDBN} and target are resposible to translate these | |
24297 | values before and after the call as needed. | |
24298 | ||
24299 | @menu | |
24300 | * Open flags:: | |
24301 | * mode_t values:: | |
24302 | * Errno values:: | |
24303 | * Lseek flags:: | |
24304 | * Limits:: | |
24305 | @end menu | |
24306 | ||
24307 | @node Open flags | |
24308 | @unnumberedsubsubsec Open flags | |
24309 | @cindex open flags, in file-i/o protocol | |
24310 | ||
24311 | All values are given in hexadecimal representation. | |
24312 | ||
24313 | @smallexample | |
24314 | O_RDONLY 0x0 | |
24315 | O_WRONLY 0x1 | |
24316 | O_RDWR 0x2 | |
24317 | O_APPEND 0x8 | |
24318 | O_CREAT 0x200 | |
24319 | O_TRUNC 0x400 | |
24320 | O_EXCL 0x800 | |
24321 | @end smallexample | |
24322 | ||
24323 | @node mode_t values | |
24324 | @unnumberedsubsubsec mode_t values | |
24325 | @cindex mode_t values, in file-i/o protocol | |
24326 | ||
24327 | All values are given in octal representation. | |
24328 | ||
24329 | @smallexample | |
24330 | S_IFREG 0100000 | |
24331 | S_IFDIR 040000 | |
24332 | S_IRUSR 0400 | |
24333 | S_IWUSR 0200 | |
24334 | S_IXUSR 0100 | |
24335 | S_IRGRP 040 | |
24336 | S_IWGRP 020 | |
24337 | S_IXGRP 010 | |
24338 | S_IROTH 04 | |
24339 | S_IWOTH 02 | |
24340 | S_IXOTH 01 | |
24341 | @end smallexample | |
24342 | ||
24343 | @node Errno values | |
24344 | @unnumberedsubsubsec Errno values | |
24345 | @cindex errno values, in file-i/o protocol | |
24346 | ||
24347 | All values are given in decimal representation. | |
24348 | ||
24349 | @smallexample | |
24350 | EPERM 1 | |
24351 | ENOENT 2 | |
24352 | EINTR 4 | |
24353 | EBADF 9 | |
24354 | EACCES 13 | |
24355 | EFAULT 14 | |
24356 | EBUSY 16 | |
24357 | EEXIST 17 | |
24358 | ENODEV 19 | |
24359 | ENOTDIR 20 | |
24360 | EISDIR 21 | |
24361 | EINVAL 22 | |
24362 | ENFILE 23 | |
24363 | EMFILE 24 | |
24364 | EFBIG 27 | |
24365 | ENOSPC 28 | |
24366 | ESPIPE 29 | |
24367 | EROFS 30 | |
24368 | ENAMETOOLONG 91 | |
24369 | EUNKNOWN 9999 | |
24370 | @end smallexample | |
24371 | ||
24372 | EUNKNOWN is used as a fallback error value if a host system returns | |
24373 | any error value not in the list of supported error numbers. | |
24374 | ||
24375 | @node Lseek flags | |
24376 | @unnumberedsubsubsec Lseek flags | |
24377 | @cindex lseek flags, in file-i/o protocol | |
24378 | ||
24379 | @smallexample | |
24380 | SEEK_SET 0 | |
24381 | SEEK_CUR 1 | |
24382 | SEEK_END 2 | |
24383 | @end smallexample | |
24384 | ||
24385 | @node Limits | |
24386 | @unnumberedsubsubsec Limits | |
24387 | @cindex limits, in file-i/o protocol | |
24388 | ||
24389 | All values are given in decimal representation. | |
24390 | ||
24391 | @smallexample | |
24392 | INT_MIN -2147483648 | |
24393 | INT_MAX 2147483647 | |
24394 | UINT_MAX 4294967295 | |
24395 | LONG_MIN -9223372036854775808 | |
24396 | LONG_MAX 9223372036854775807 | |
24397 | ULONG_MAX 18446744073709551615 | |
24398 | @end smallexample | |
24399 | ||
24400 | @node File-I/O Examples | |
24401 | @subsection File-I/O Examples | |
24402 | @cindex file-i/o examples | |
24403 | ||
24404 | Example sequence of a write call, file descriptor 3, buffer is at target | |
24405 | address 0x1234, 6 bytes should be written: | |
24406 | ||
24407 | @smallexample | |
24408 | <- @code{Fwrite,3,1234,6} | |
24409 | @emph{request memory read from target} | |
24410 | -> @code{m1234,6} | |
24411 | <- XXXXXX | |
24412 | @emph{return "6 bytes written"} | |
24413 | -> @code{F6} | |
24414 | @end smallexample | |
24415 | ||
24416 | Example sequence of a read call, file descriptor 3, buffer is at target | |
24417 | address 0x1234, 6 bytes should be read: | |
24418 | ||
24419 | @smallexample | |
24420 | <- @code{Fread,3,1234,6} | |
24421 | @emph{request memory write to target} | |
24422 | -> @code{X1234,6:XXXXXX} | |
24423 | @emph{return "6 bytes read"} | |
24424 | -> @code{F6} | |
24425 | @end smallexample | |
24426 | ||
24427 | Example sequence of a read call, call fails on the host due to invalid | |
24428 | file descriptor (EBADF): | |
24429 | ||
24430 | @smallexample | |
24431 | <- @code{Fread,3,1234,6} | |
24432 | -> @code{F-1,9} | |
24433 | @end smallexample | |
24434 | ||
24435 | Example sequence of a read call, user presses Ctrl-C before syscall on | |
24436 | host is called: | |
24437 | ||
24438 | @smallexample | |
24439 | <- @code{Fread,3,1234,6} | |
24440 | -> @code{F-1,4,C} | |
24441 | <- @code{T02} | |
24442 | @end smallexample | |
24443 | ||
24444 | Example sequence of a read call, user presses Ctrl-C after syscall on | |
24445 | host is called: | |
24446 | ||
24447 | @smallexample | |
24448 | <- @code{Fread,3,1234,6} | |
24449 | -> @code{X1234,6:XXXXXX} | |
24450 | <- @code{T02} | |
24451 | @end smallexample | |
24452 | ||
f418dd93 DJ |
24453 | @include agentexpr.texi |
24454 | ||
aab4e0ec | 24455 | @include gpl.texi |
eb12ee30 | 24456 | |
2154891a | 24457 | @raisesections |
6826cf00 | 24458 | @include fdl.texi |
2154891a | 24459 | @lowersections |
6826cf00 | 24460 | |
6d2ebf8b | 24461 | @node Index |
c906108c SS |
24462 | @unnumbered Index |
24463 | ||
24464 | @printindex cp | |
24465 | ||
24466 | @tex | |
24467 | % I think something like @colophon should be in texinfo. In the | |
24468 | % meantime: | |
24469 | \long\def\colophon{\hbox to0pt{}\vfill | |
24470 | \centerline{The body of this manual is set in} | |
24471 | \centerline{\fontname\tenrm,} | |
24472 | \centerline{with headings in {\bf\fontname\tenbf}} | |
24473 | \centerline{and examples in {\tt\fontname\tentt}.} | |
24474 | \centerline{{\it\fontname\tenit\/},} | |
24475 | \centerline{{\bf\fontname\tenbf}, and} | |
24476 | \centerline{{\sl\fontname\tensl\/}} | |
24477 | \centerline{are used for emphasis.}\vfill} | |
24478 | \page\colophon | |
24479 | % Blame: doc@cygnus.com, 1991. | |
24480 | @end tex | |
24481 | ||
c906108c | 24482 | @bye |