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c906108c | 1 | \input texinfo @c -*-texinfo-*- |
b6ba6518 | 2 | @c Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, |
1e698235 | 3 | @c 1999, 2000, 2001, 2002, 2003 |
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. |
96a2c332 SS |
41 | @dircategory Programming & development tools. |
42 | @direntry | |
c906108c | 43 | * Gdb: (gdb). The @sc{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,@* |
1e698235 | 55 | 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. |
c906108c | 56 | |
e9c75b65 EZ |
57 | Permission is granted to copy, distribute and/or modify this document |
58 | under the terms of the GNU Free Documentation License, Version 1.1 or | |
59 | any later version published by the Free Software Foundation; with the | |
959acfd1 EZ |
60 | Invariant Sections being ``Free Software'' and ``Free Software Needs |
61 | Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' | |
62 | and with the Back-Cover Texts as in (a) below. | |
c906108c | 63 | |
6826cf00 EZ |
64 | (a) The Free Software Foundation's Back-Cover Text is: ``You have |
65 | freedom to copy and modify this GNU Manual, like GNU software. Copies | |
66 | published by the Free Software Foundation raise funds for GNU | |
67 | development.'' | |
c906108c SS |
68 | @end ifinfo |
69 | ||
70 | @titlepage | |
71 | @title Debugging with @value{GDBN} | |
72 | @subtitle The @sc{gnu} Source-Level Debugger | |
c906108c | 73 | @sp 1 |
c906108c | 74 | @subtitle @value{EDITION} Edition, for @value{GDBN} version @value{GDBVN} |
9e9c5ae7 | 75 | @author Richard Stallman, Roland Pesch, Stan Shebs, et al. |
c906108c | 76 | @page |
c906108c SS |
77 | @tex |
78 | {\parskip=0pt | |
53a5351d | 79 | \hfill (Send bugs and comments on @value{GDBN} to bug-gdb\@gnu.org.)\par |
c906108c SS |
80 | \hfill {\it Debugging with @value{GDBN}}\par |
81 | \hfill \TeX{}info \texinfoversion\par | |
82 | } | |
83 | @end tex | |
53a5351d | 84 | |
c906108c | 85 | @vskip 0pt plus 1filll |
8a037dd7 | 86 | Copyright @copyright{} 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
1e698235 | 87 | 1996, 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. |
c906108c | 88 | @sp 2 |
c906108c SS |
89 | Published by the Free Software Foundation @* |
90 | 59 Temple Place - Suite 330, @* | |
91 | Boston, MA 02111-1307 USA @* | |
6d2ebf8b | 92 | ISBN 1-882114-77-9 @* |
e9c75b65 EZ |
93 | |
94 | Permission is granted to copy, distribute and/or modify this document | |
95 | under the terms of the GNU Free Documentation License, Version 1.1 or | |
96 | any later version published by the Free Software Foundation; with the | |
959acfd1 EZ |
97 | Invariant Sections being ``Free Software'' and ``Free Software Needs |
98 | Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' | |
99 | and with the Back-Cover Texts as in (a) below. | |
e9c75b65 | 100 | |
6826cf00 EZ |
101 | (a) The Free Software Foundation's Back-Cover Text is: ``You have |
102 | freedom to copy and modify this GNU Manual, like GNU software. Copies | |
103 | published by the Free Software Foundation raise funds for GNU | |
104 | development.'' | |
c906108c SS |
105 | @end titlepage |
106 | @page | |
107 | ||
6c0e9fb3 | 108 | @ifnottex |
6d2ebf8b SS |
109 | @node Top, Summary, (dir), (dir) |
110 | ||
c906108c SS |
111 | @top Debugging with @value{GDBN} |
112 | ||
113 | This file describes @value{GDBN}, the @sc{gnu} symbolic debugger. | |
114 | ||
9fe8321b | 115 | This is the @value{EDITION} Edition, for @value{GDBN} Version |
c906108c SS |
116 | @value{GDBVN}. |
117 | ||
1e698235 | 118 | Copyright (C) 1988-2003 Free Software Foundation, Inc. |
6d2ebf8b SS |
119 | |
120 | @menu | |
121 | * Summary:: Summary of @value{GDBN} | |
122 | * Sample Session:: A sample @value{GDBN} session | |
123 | ||
124 | * Invocation:: Getting in and out of @value{GDBN} | |
125 | * Commands:: @value{GDBN} commands | |
126 | * Running:: Running programs under @value{GDBN} | |
127 | * Stopping:: Stopping and continuing | |
128 | * Stack:: Examining the stack | |
129 | * Source:: Examining source files | |
130 | * Data:: Examining data | |
e2e0bcd1 | 131 | * Macros:: Preprocessor Macros |
b37052ae | 132 | * Tracepoints:: Debugging remote targets non-intrusively |
df0cd8c5 | 133 | * Overlays:: Debugging programs that use overlays |
6d2ebf8b SS |
134 | |
135 | * Languages:: Using @value{GDBN} with different languages | |
136 | ||
137 | * Symbols:: Examining the symbol table | |
138 | * Altering:: Altering execution | |
139 | * GDB Files:: @value{GDBN} files | |
140 | * Targets:: Specifying a debugging target | |
6b2f586d | 141 | * Remote Debugging:: Debugging remote programs |
6d2ebf8b SS |
142 | * Configurations:: Configuration-specific information |
143 | * Controlling GDB:: Controlling @value{GDBN} | |
144 | * Sequences:: Canned sequences of commands | |
c4555f82 | 145 | * TUI:: @value{GDBN} Text User Interface |
21c294e6 | 146 | * Interpreters:: Command Interpreters |
6d2ebf8b SS |
147 | * Emacs:: Using @value{GDBN} under @sc{gnu} Emacs |
148 | * Annotations:: @value{GDBN}'s annotation interface. | |
7162c0ca | 149 | * GDB/MI:: @value{GDBN}'s Machine Interface. |
6d2ebf8b SS |
150 | |
151 | * GDB Bugs:: Reporting bugs in @value{GDBN} | |
152 | * Formatting Documentation:: How to format and print @value{GDBN} documentation | |
153 | ||
154 | * Command Line Editing:: Command Line Editing | |
155 | * Using History Interactively:: Using History Interactively | |
156 | * Installing GDB:: Installing GDB | |
eb12ee30 | 157 | * Maintenance Commands:: Maintenance Commands |
e0ce93ac | 158 | * Remote Protocol:: GDB Remote Serial Protocol |
aab4e0ec AC |
159 | * Copying:: GNU General Public License says |
160 | how you can copy and share GDB | |
6826cf00 | 161 | * GNU Free Documentation License:: The license for this documentation |
6d2ebf8b SS |
162 | * Index:: Index |
163 | @end menu | |
164 | ||
6c0e9fb3 | 165 | @end ifnottex |
c906108c | 166 | |
449f3b6c | 167 | @contents |
449f3b6c | 168 | |
6d2ebf8b | 169 | @node Summary |
c906108c SS |
170 | @unnumbered Summary of @value{GDBN} |
171 | ||
172 | The purpose of a debugger such as @value{GDBN} is to allow you to see what is | |
173 | going on ``inside'' another program while it executes---or what another | |
174 | program was doing at the moment it crashed. | |
175 | ||
176 | @value{GDBN} can do four main kinds of things (plus other things in support of | |
177 | these) to help you catch bugs in the act: | |
178 | ||
179 | @itemize @bullet | |
180 | @item | |
181 | Start your program, specifying anything that might affect its behavior. | |
182 | ||
183 | @item | |
184 | Make your program stop on specified conditions. | |
185 | ||
186 | @item | |
187 | Examine what has happened, when your program has stopped. | |
188 | ||
189 | @item | |
190 | Change things in your program, so you can experiment with correcting the | |
191 | effects of one bug and go on to learn about another. | |
192 | @end itemize | |
193 | ||
cce74817 | 194 | You can use @value{GDBN} to debug programs written in C and C++. |
c906108c | 195 | For more information, see @ref{Support,,Supported languages}. |
c906108c SS |
196 | For more information, see @ref{C,,C and C++}. |
197 | ||
cce74817 | 198 | @cindex Modula-2 |
e632838e AC |
199 | Support for Modula-2 is partial. For information on Modula-2, see |
200 | @ref{Modula-2,,Modula-2}. | |
c906108c | 201 | |
cce74817 JM |
202 | @cindex Pascal |
203 | Debugging Pascal programs which use sets, subranges, file variables, or | |
204 | nested functions does not currently work. @value{GDBN} does not support | |
205 | entering expressions, printing values, or similar features using Pascal | |
206 | syntax. | |
c906108c | 207 | |
c906108c SS |
208 | @cindex Fortran |
209 | @value{GDBN} can be used to debug programs written in Fortran, although | |
53a5351d | 210 | it may be necessary to refer to some variables with a trailing |
cce74817 | 211 | underscore. |
c906108c | 212 | |
c906108c SS |
213 | @menu |
214 | * Free Software:: Freely redistributable software | |
215 | * Contributors:: Contributors to GDB | |
216 | @end menu | |
217 | ||
6d2ebf8b | 218 | @node Free Software |
c906108c SS |
219 | @unnumberedsec Free software |
220 | ||
5d161b24 | 221 | @value{GDBN} is @dfn{free software}, protected by the @sc{gnu} |
c906108c SS |
222 | General Public License |
223 | (GPL). The GPL gives you the freedom to copy or adapt a licensed | |
224 | program---but every person getting a copy also gets with it the | |
225 | freedom to modify that copy (which means that they must get access to | |
226 | the source code), and the freedom to distribute further copies. | |
227 | Typical software companies use copyrights to limit your freedoms; the | |
228 | Free Software Foundation uses the GPL to preserve these freedoms. | |
229 | ||
230 | Fundamentally, the General Public License is a license which says that | |
231 | you have these freedoms and that you cannot take these freedoms away | |
232 | from anyone else. | |
233 | ||
2666264b | 234 | @unnumberedsec Free Software Needs Free Documentation |
959acfd1 EZ |
235 | |
236 | The biggest deficiency in the free software community today is not in | |
237 | the software---it is the lack of good free documentation that we can | |
238 | include with the free software. Many of our most important | |
239 | programs do not come with free reference manuals and free introductory | |
240 | texts. Documentation is an essential part of any software package; | |
241 | when an important free software package does not come with a free | |
242 | manual and a free tutorial, that is a major gap. We have many such | |
243 | gaps today. | |
244 | ||
245 | Consider Perl, for instance. The tutorial manuals that people | |
246 | normally use are non-free. How did this come about? Because the | |
247 | authors of those manuals published them with restrictive terms---no | |
248 | copying, no modification, source files not available---which exclude | |
249 | them from the free software world. | |
250 | ||
251 | That wasn't the first time this sort of thing happened, and it was far | |
252 | from the last. Many times we have heard a GNU user eagerly describe a | |
253 | manual that he is writing, his intended contribution to the community, | |
254 | only to learn that he had ruined everything by signing a publication | |
255 | contract to make it non-free. | |
256 | ||
257 | Free documentation, like free software, is a matter of freedom, not | |
258 | price. The problem with the non-free manual is not that publishers | |
259 | charge a price for printed copies---that in itself is fine. (The Free | |
260 | Software Foundation sells printed copies of manuals, too.) The | |
261 | problem is the restrictions on the use of the manual. Free manuals | |
262 | are available in source code form, and give you permission to copy and | |
263 | modify. Non-free manuals do not allow this. | |
264 | ||
265 | The criteria of freedom for a free manual are roughly the same as for | |
266 | free software. Redistribution (including the normal kinds of | |
267 | commercial redistribution) must be permitted, so that the manual can | |
268 | accompany every copy of the program, both on-line and on paper. | |
269 | ||
270 | Permission for modification of the technical content is crucial too. | |
271 | When people modify the software, adding or changing features, if they | |
272 | are conscientious they will change the manual too---so they can | |
273 | provide accurate and clear documentation for the modified program. A | |
274 | manual that leaves you no choice but to write a new manual to document | |
275 | a changed version of the program is not really available to our | |
276 | community. | |
277 | ||
278 | Some kinds of limits on the way modification is handled are | |
279 | acceptable. For example, requirements to preserve the original | |
280 | author's copyright notice, the distribution terms, or the list of | |
281 | authors, are ok. It is also no problem to require modified versions | |
282 | to include notice that they were modified. Even entire sections that | |
283 | may not be deleted or changed are acceptable, as long as they deal | |
284 | with nontechnical topics (like this one). These kinds of restrictions | |
285 | are acceptable because they don't obstruct the community's normal use | |
286 | of the manual. | |
287 | ||
288 | However, it must be possible to modify all the @emph{technical} | |
289 | content of the manual, and then distribute the result in all the usual | |
290 | media, through all the usual channels. Otherwise, the restrictions | |
291 | obstruct the use of the manual, it is not free, and we need another | |
292 | manual to replace it. | |
293 | ||
294 | Please spread the word about this issue. Our community continues to | |
295 | lose manuals to proprietary publishing. If we spread the word that | |
296 | free software needs free reference manuals and free tutorials, perhaps | |
297 | the next person who wants to contribute by writing documentation will | |
298 | realize, before it is too late, that only free manuals contribute to | |
299 | the free software community. | |
300 | ||
301 | If you are writing documentation, please insist on publishing it under | |
302 | the GNU Free Documentation License or another free documentation | |
303 | license. Remember that this decision requires your approval---you | |
304 | don't have to let the publisher decide. Some commercial publishers | |
305 | will use a free license if you insist, but they will not propose the | |
306 | option; it is up to you to raise the issue and say firmly that this is | |
307 | what you want. If the publisher you are dealing with refuses, please | |
308 | try other publishers. If you're not sure whether a proposed license | |
42584a72 | 309 | is free, write to @email{licensing@@gnu.org}. |
959acfd1 EZ |
310 | |
311 | You can encourage commercial publishers to sell more free, copylefted | |
312 | manuals and tutorials by buying them, and particularly by buying | |
313 | copies from the publishers that paid for their writing or for major | |
314 | improvements. Meanwhile, try to avoid buying non-free documentation | |
315 | at all. Check the distribution terms of a manual before you buy it, | |
316 | and insist that whoever seeks your business must respect your freedom. | |
72c9928d EZ |
317 | Check the history of the book, and try to reward the publishers that |
318 | have paid or pay the authors to work on it. | |
959acfd1 EZ |
319 | |
320 | The Free Software Foundation maintains a list of free documentation | |
321 | published by other publishers, at | |
322 | @url{http://www.fsf.org/doc/other-free-books.html}. | |
323 | ||
6d2ebf8b | 324 | @node Contributors |
96a2c332 SS |
325 | @unnumberedsec Contributors to @value{GDBN} |
326 | ||
327 | Richard Stallman was the original author of @value{GDBN}, and of many | |
328 | other @sc{gnu} programs. Many others have contributed to its | |
329 | development. This section attempts to credit major contributors. One | |
330 | of the virtues of free software is that everyone is free to contribute | |
331 | to it; with regret, we cannot actually acknowledge everyone here. The | |
332 | file @file{ChangeLog} in the @value{GDBN} distribution approximates a | |
c906108c SS |
333 | blow-by-blow account. |
334 | ||
335 | Changes much prior to version 2.0 are lost in the mists of time. | |
336 | ||
337 | @quotation | |
338 | @emph{Plea:} Additions to this section are particularly welcome. If you | |
339 | or your friends (or enemies, to be evenhanded) have been unfairly | |
340 | omitted from this list, we would like to add your names! | |
341 | @end quotation | |
342 | ||
343 | So that they may not regard their many labors as thankless, we | |
344 | particularly thank those who shepherded @value{GDBN} through major | |
345 | releases: | |
299ffc64 | 346 | Andrew Cagney (releases 5.3, 5.2, 5.1 and 5.0); |
c906108c SS |
347 | Jim Blandy (release 4.18); |
348 | Jason Molenda (release 4.17); | |
349 | Stan Shebs (release 4.14); | |
350 | Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9); | |
351 | Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4); | |
352 | John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); | |
353 | Jim Kingdon (releases 3.5, 3.4, and 3.3); | |
354 | and Randy Smith (releases 3.2, 3.1, and 3.0). | |
355 | ||
356 | Richard Stallman, assisted at various times by Peter TerMaat, Chris | |
357 | Hanson, and Richard Mlynarik, handled releases through 2.8. | |
358 | ||
b37052ae EZ |
359 | Michael Tiemann is the author of most of the @sc{gnu} C@t{++} support |
360 | in @value{GDBN}, with significant additional contributions from Per | |
361 | Bothner and Daniel Berlin. James Clark wrote the @sc{gnu} C@t{++} | |
362 | demangler. Early work on C@t{++} was by Peter TerMaat (who also did | |
363 | much general update work leading to release 3.0). | |
c906108c | 364 | |
b37052ae | 365 | @value{GDBN} uses the BFD subroutine library to examine multiple |
c906108c SS |
366 | object-file formats; BFD was a joint project of David V. |
367 | Henkel-Wallace, Rich Pixley, Steve Chamberlain, and John Gilmore. | |
368 | ||
369 | David Johnson wrote the original COFF support; Pace Willison did | |
370 | the original support for encapsulated COFF. | |
371 | ||
0179ffac | 372 | Brent Benson of Harris Computer Systems contributed DWARF 2 support. |
c906108c SS |
373 | |
374 | Adam de Boor and Bradley Davis contributed the ISI Optimum V support. | |
375 | Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS | |
376 | support. | |
377 | Jean-Daniel Fekete contributed Sun 386i support. | |
378 | Chris Hanson improved the HP9000 support. | |
379 | Noboyuki Hikichi and Tomoyuki Hasei contributed Sony/News OS 3 support. | |
380 | David Johnson contributed Encore Umax support. | |
381 | Jyrki Kuoppala contributed Altos 3068 support. | |
382 | Jeff Law contributed HP PA and SOM support. | |
383 | Keith Packard contributed NS32K support. | |
384 | Doug Rabson contributed Acorn Risc Machine support. | |
385 | Bob Rusk contributed Harris Nighthawk CX-UX support. | |
386 | Chris Smith contributed Convex support (and Fortran debugging). | |
387 | Jonathan Stone contributed Pyramid support. | |
388 | Michael Tiemann contributed SPARC support. | |
389 | Tim Tucker contributed support for the Gould NP1 and Gould Powernode. | |
390 | Pace Willison contributed Intel 386 support. | |
391 | Jay Vosburgh contributed Symmetry support. | |
a37295f9 | 392 | Marko Mlinar contributed OpenRISC 1000 support. |
c906108c | 393 | |
1104b9e7 | 394 | Andreas Schwab contributed M68K @sc{gnu}/Linux support. |
c906108c SS |
395 | |
396 | Rich Schaefer and Peter Schauer helped with support of SunOS shared | |
397 | libraries. | |
398 | ||
399 | Jay Fenlason and Roland McGrath ensured that @value{GDBN} and GAS agree | |
400 | about several machine instruction sets. | |
401 | ||
402 | Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped develop | |
403 | remote debugging. Intel Corporation, Wind River Systems, AMD, and ARM | |
404 | contributed remote debugging modules for the i960, VxWorks, A29K UDI, | |
405 | and RDI targets, respectively. | |
406 | ||
407 | Brian Fox is the author of the readline libraries providing | |
408 | command-line editing and command history. | |
409 | ||
7a292a7a SS |
410 | Andrew Beers of SUNY Buffalo wrote the language-switching code, the |
411 | Modula-2 support, and contributed the Languages chapter of this manual. | |
c906108c | 412 | |
5d161b24 | 413 | Fred Fish wrote most of the support for Unix System Vr4. |
b37052ae | 414 | He also enhanced the command-completion support to cover C@t{++} overloaded |
c906108c | 415 | symbols. |
c906108c SS |
416 | |
417 | Hitachi America, Ltd. sponsored the support for H8/300, H8/500, and | |
418 | Super-H processors. | |
419 | ||
420 | NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx processors. | |
421 | ||
422 | Mitsubishi sponsored the support for D10V, D30V, and M32R/D processors. | |
423 | ||
424 | Toshiba sponsored the support for the TX39 Mips processor. | |
425 | ||
426 | Matsushita sponsored the support for the MN10200 and MN10300 processors. | |
427 | ||
96a2c332 | 428 | Fujitsu sponsored the support for SPARClite and FR30 processors. |
c906108c SS |
429 | |
430 | Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware | |
431 | watchpoints. | |
432 | ||
433 | Michael Snyder added support for tracepoints. | |
434 | ||
435 | Stu Grossman wrote gdbserver. | |
436 | ||
437 | Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made | |
96a2c332 | 438 | nearly innumerable bug fixes and cleanups throughout @value{GDBN}. |
c906108c SS |
439 | |
440 | The following people at the Hewlett-Packard Company contributed | |
441 | support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0 | |
b37052ae | 442 | (narrow mode), HP's implementation of kernel threads, HP's aC@t{++} |
c906108c SS |
443 | compiler, and the terminal user interface: Ben Krepp, Richard Title, |
444 | John Bishop, Susan Macchia, Kathy Mann, Satish Pai, India Paul, Steve | |
445 | Rehrauer, and Elena Zannoni. Kim Haase provided HP-specific | |
446 | information in this manual. | |
447 | ||
b37052ae EZ |
448 | DJ Delorie ported @value{GDBN} to MS-DOS, for the DJGPP project. |
449 | Robert Hoehne made significant contributions to the DJGPP port. | |
450 | ||
96a2c332 SS |
451 | Cygnus Solutions has sponsored @value{GDBN} maintenance and much of its |
452 | development since 1991. Cygnus engineers who have worked on @value{GDBN} | |
2df3850c JM |
453 | fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin |
454 | Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim | |
455 | Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler, | |
456 | Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek | |
457 | Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In | |
458 | addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton, | |
459 | JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug | |
460 | Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff | |
461 | Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner, | |
462 | Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin | |
463 | Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela | |
464 | Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David | |
465 | Zuhn have made contributions both large and small. | |
c906108c | 466 | |
e2e0bcd1 JB |
467 | Jim Blandy added support for preprocessor macros, while working for Red |
468 | Hat. | |
c906108c | 469 | |
6d2ebf8b | 470 | @node Sample Session |
c906108c SS |
471 | @chapter A Sample @value{GDBN} Session |
472 | ||
473 | You can use this manual at your leisure to read all about @value{GDBN}. | |
474 | However, a handful of commands are enough to get started using the | |
475 | debugger. This chapter illustrates those commands. | |
476 | ||
477 | @iftex | |
478 | In this sample session, we emphasize user input like this: @b{input}, | |
479 | to make it easier to pick out from the surrounding output. | |
480 | @end iftex | |
481 | ||
482 | @c FIXME: this example may not be appropriate for some configs, where | |
483 | @c FIXME...primary interest is in remote use. | |
484 | ||
485 | One of the preliminary versions of @sc{gnu} @code{m4} (a generic macro | |
486 | processor) exhibits the following bug: sometimes, when we change its | |
487 | quote strings from the default, the commands used to capture one macro | |
488 | definition within another stop working. In the following short @code{m4} | |
489 | session, we define a macro @code{foo} which expands to @code{0000}; we | |
490 | then use the @code{m4} built-in @code{defn} to define @code{bar} as the | |
491 | same thing. However, when we change the open quote string to | |
492 | @code{<QUOTE>} and the close quote string to @code{<UNQUOTE>}, the same | |
493 | procedure fails to define a new synonym @code{baz}: | |
494 | ||
495 | @smallexample | |
496 | $ @b{cd gnu/m4} | |
497 | $ @b{./m4} | |
498 | @b{define(foo,0000)} | |
499 | ||
500 | @b{foo} | |
501 | 0000 | |
502 | @b{define(bar,defn(`foo'))} | |
503 | ||
504 | @b{bar} | |
505 | 0000 | |
506 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
507 | ||
508 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
509 | @b{baz} | |
510 | @b{C-d} | |
511 | m4: End of input: 0: fatal error: EOF in string | |
512 | @end smallexample | |
513 | ||
514 | @noindent | |
515 | Let us use @value{GDBN} to try to see what is going on. | |
516 | ||
c906108c SS |
517 | @smallexample |
518 | $ @b{@value{GDBP} m4} | |
519 | @c FIXME: this falsifies the exact text played out, to permit smallbook | |
520 | @c FIXME... format to come out better. | |
521 | @value{GDBN} is free software and you are welcome to distribute copies | |
5d161b24 | 522 | of it under certain conditions; type "show copying" to see |
c906108c | 523 | the conditions. |
5d161b24 | 524 | There is absolutely no warranty for @value{GDBN}; type "show warranty" |
c906108c SS |
525 | for details. |
526 | ||
527 | @value{GDBN} @value{GDBVN}, Copyright 1999 Free Software Foundation, Inc... | |
528 | (@value{GDBP}) | |
529 | @end smallexample | |
c906108c SS |
530 | |
531 | @noindent | |
532 | @value{GDBN} reads only enough symbol data to know where to find the | |
533 | rest when needed; as a result, the first prompt comes up very quickly. | |
534 | We now tell @value{GDBN} to use a narrower display width than usual, so | |
535 | that examples fit in this manual. | |
536 | ||
537 | @smallexample | |
538 | (@value{GDBP}) @b{set width 70} | |
539 | @end smallexample | |
540 | ||
541 | @noindent | |
542 | We need to see how the @code{m4} built-in @code{changequote} works. | |
543 | Having looked at the source, we know the relevant subroutine is | |
544 | @code{m4_changequote}, so we set a breakpoint there with the @value{GDBN} | |
545 | @code{break} command. | |
546 | ||
547 | @smallexample | |
548 | (@value{GDBP}) @b{break m4_changequote} | |
549 | Breakpoint 1 at 0x62f4: file builtin.c, line 879. | |
550 | @end smallexample | |
551 | ||
552 | @noindent | |
553 | Using the @code{run} command, we start @code{m4} running under @value{GDBN} | |
554 | control; as long as control does not reach the @code{m4_changequote} | |
555 | subroutine, the program runs as usual: | |
556 | ||
557 | @smallexample | |
558 | (@value{GDBP}) @b{run} | |
559 | Starting program: /work/Editorial/gdb/gnu/m4/m4 | |
560 | @b{define(foo,0000)} | |
561 | ||
562 | @b{foo} | |
563 | 0000 | |
564 | @end smallexample | |
565 | ||
566 | @noindent | |
567 | To trigger the breakpoint, we call @code{changequote}. @value{GDBN} | |
568 | suspends execution of @code{m4}, displaying information about the | |
569 | context where it stops. | |
570 | ||
571 | @smallexample | |
572 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
573 | ||
5d161b24 | 574 | Breakpoint 1, m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
575 | at builtin.c:879 |
576 | 879 if (bad_argc(TOKEN_DATA_TEXT(argv[0]),argc,1,3)) | |
577 | @end smallexample | |
578 | ||
579 | @noindent | |
580 | Now we use the command @code{n} (@code{next}) to advance execution to | |
581 | the next line of the current function. | |
582 | ||
583 | @smallexample | |
584 | (@value{GDBP}) @b{n} | |
585 | 882 set_quotes((argc >= 2) ? TOKEN_DATA_TEXT(argv[1])\ | |
586 | : nil, | |
587 | @end smallexample | |
588 | ||
589 | @noindent | |
590 | @code{set_quotes} looks like a promising subroutine. We can go into it | |
591 | by using the command @code{s} (@code{step}) instead of @code{next}. | |
592 | @code{step} goes to the next line to be executed in @emph{any} | |
593 | subroutine, so it steps into @code{set_quotes}. | |
594 | ||
595 | @smallexample | |
596 | (@value{GDBP}) @b{s} | |
597 | set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
598 | at input.c:530 | |
599 | 530 if (lquote != def_lquote) | |
600 | @end smallexample | |
601 | ||
602 | @noindent | |
603 | The display that shows the subroutine where @code{m4} is now | |
604 | suspended (and its arguments) is called a stack frame display. It | |
605 | shows a summary of the stack. We can use the @code{backtrace} | |
606 | command (which can also be spelled @code{bt}), to see where we are | |
607 | in the stack as a whole: the @code{backtrace} command displays a | |
608 | stack frame for each active subroutine. | |
609 | ||
610 | @smallexample | |
611 | (@value{GDBP}) @b{bt} | |
612 | #0 set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
613 | at input.c:530 | |
5d161b24 | 614 | #1 0x6344 in m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
615 | at builtin.c:882 |
616 | #2 0x8174 in expand_macro (sym=0x33320) at macro.c:242 | |
617 | #3 0x7a88 in expand_token (obs=0x0, t=209696, td=0xf7fffa30) | |
618 | at macro.c:71 | |
619 | #4 0x79dc in expand_input () at macro.c:40 | |
620 | #5 0x2930 in main (argc=0, argv=0xf7fffb20) at m4.c:195 | |
621 | @end smallexample | |
622 | ||
623 | @noindent | |
624 | We step through a few more lines to see what happens. The first two | |
625 | times, we can use @samp{s}; the next two times we use @code{n} to avoid | |
626 | falling into the @code{xstrdup} subroutine. | |
627 | ||
628 | @smallexample | |
629 | (@value{GDBP}) @b{s} | |
630 | 0x3b5c 532 if (rquote != def_rquote) | |
631 | (@value{GDBP}) @b{s} | |
632 | 0x3b80 535 lquote = (lq == nil || *lq == '\0') ? \ | |
633 | def_lquote : xstrdup(lq); | |
634 | (@value{GDBP}) @b{n} | |
635 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
636 | : xstrdup(rq); | |
637 | (@value{GDBP}) @b{n} | |
638 | 538 len_lquote = strlen(rquote); | |
639 | @end smallexample | |
640 | ||
641 | @noindent | |
642 | The last line displayed looks a little odd; we can examine the variables | |
643 | @code{lquote} and @code{rquote} to see if they are in fact the new left | |
644 | and right quotes we specified. We use the command @code{p} | |
645 | (@code{print}) to see their values. | |
646 | ||
647 | @smallexample | |
648 | (@value{GDBP}) @b{p lquote} | |
649 | $1 = 0x35d40 "<QUOTE>" | |
650 | (@value{GDBP}) @b{p rquote} | |
651 | $2 = 0x35d50 "<UNQUOTE>" | |
652 | @end smallexample | |
653 | ||
654 | @noindent | |
655 | @code{lquote} and @code{rquote} are indeed the new left and right quotes. | |
656 | To look at some context, we can display ten lines of source | |
657 | surrounding the current line with the @code{l} (@code{list}) command. | |
658 | ||
659 | @smallexample | |
660 | (@value{GDBP}) @b{l} | |
661 | 533 xfree(rquote); | |
662 | 534 | |
663 | 535 lquote = (lq == nil || *lq == '\0') ? def_lquote\ | |
664 | : xstrdup (lq); | |
665 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
666 | : xstrdup (rq); | |
667 | 537 | |
668 | 538 len_lquote = strlen(rquote); | |
669 | 539 len_rquote = strlen(lquote); | |
670 | 540 @} | |
671 | 541 | |
672 | 542 void | |
673 | @end smallexample | |
674 | ||
675 | @noindent | |
676 | Let us step past the two lines that set @code{len_lquote} and | |
677 | @code{len_rquote}, and then examine the values of those variables. | |
678 | ||
679 | @smallexample | |
680 | (@value{GDBP}) @b{n} | |
681 | 539 len_rquote = strlen(lquote); | |
682 | (@value{GDBP}) @b{n} | |
683 | 540 @} | |
684 | (@value{GDBP}) @b{p len_lquote} | |
685 | $3 = 9 | |
686 | (@value{GDBP}) @b{p len_rquote} | |
687 | $4 = 7 | |
688 | @end smallexample | |
689 | ||
690 | @noindent | |
691 | That certainly looks wrong, assuming @code{len_lquote} and | |
692 | @code{len_rquote} are meant to be the lengths of @code{lquote} and | |
693 | @code{rquote} respectively. We can set them to better values using | |
694 | the @code{p} command, since it can print the value of | |
695 | any expression---and that expression can include subroutine calls and | |
696 | assignments. | |
697 | ||
698 | @smallexample | |
699 | (@value{GDBP}) @b{p len_lquote=strlen(lquote)} | |
700 | $5 = 7 | |
701 | (@value{GDBP}) @b{p len_rquote=strlen(rquote)} | |
702 | $6 = 9 | |
703 | @end smallexample | |
704 | ||
705 | @noindent | |
706 | Is that enough to fix the problem of using the new quotes with the | |
707 | @code{m4} built-in @code{defn}? We can allow @code{m4} to continue | |
708 | executing with the @code{c} (@code{continue}) command, and then try the | |
709 | example that caused trouble initially: | |
710 | ||
711 | @smallexample | |
712 | (@value{GDBP}) @b{c} | |
713 | Continuing. | |
714 | ||
715 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
716 | ||
717 | baz | |
718 | 0000 | |
719 | @end smallexample | |
720 | ||
721 | @noindent | |
722 | Success! The new quotes now work just as well as the default ones. The | |
723 | problem seems to have been just the two typos defining the wrong | |
724 | lengths. We allow @code{m4} exit by giving it an EOF as input: | |
725 | ||
726 | @smallexample | |
727 | @b{C-d} | |
728 | Program exited normally. | |
729 | @end smallexample | |
730 | ||
731 | @noindent | |
732 | The message @samp{Program exited normally.} is from @value{GDBN}; it | |
733 | indicates @code{m4} has finished executing. We can end our @value{GDBN} | |
734 | session with the @value{GDBN} @code{quit} command. | |
735 | ||
736 | @smallexample | |
737 | (@value{GDBP}) @b{quit} | |
738 | @end smallexample | |
c906108c | 739 | |
6d2ebf8b | 740 | @node Invocation |
c906108c SS |
741 | @chapter Getting In and Out of @value{GDBN} |
742 | ||
743 | This chapter discusses how to start @value{GDBN}, and how to get out of it. | |
5d161b24 | 744 | The essentials are: |
c906108c | 745 | @itemize @bullet |
5d161b24 | 746 | @item |
53a5351d | 747 | type @samp{@value{GDBP}} to start @value{GDBN}. |
5d161b24 | 748 | @item |
c906108c SS |
749 | type @kbd{quit} or @kbd{C-d} to exit. |
750 | @end itemize | |
751 | ||
752 | @menu | |
753 | * Invoking GDB:: How to start @value{GDBN} | |
754 | * Quitting GDB:: How to quit @value{GDBN} | |
755 | * Shell Commands:: How to use shell commands inside @value{GDBN} | |
756 | @end menu | |
757 | ||
6d2ebf8b | 758 | @node Invoking GDB |
c906108c SS |
759 | @section Invoking @value{GDBN} |
760 | ||
c906108c SS |
761 | Invoke @value{GDBN} by running the program @code{@value{GDBP}}. Once started, |
762 | @value{GDBN} reads commands from the terminal until you tell it to exit. | |
763 | ||
764 | You can also run @code{@value{GDBP}} with a variety of arguments and options, | |
765 | to specify more of your debugging environment at the outset. | |
766 | ||
c906108c SS |
767 | The command-line options described here are designed |
768 | to cover a variety of situations; in some environments, some of these | |
5d161b24 | 769 | options may effectively be unavailable. |
c906108c SS |
770 | |
771 | The most usual way to start @value{GDBN} is with one argument, | |
772 | specifying an executable program: | |
773 | ||
474c8240 | 774 | @smallexample |
c906108c | 775 | @value{GDBP} @var{program} |
474c8240 | 776 | @end smallexample |
c906108c | 777 | |
c906108c SS |
778 | @noindent |
779 | You can also start with both an executable program and a core file | |
780 | specified: | |
781 | ||
474c8240 | 782 | @smallexample |
c906108c | 783 | @value{GDBP} @var{program} @var{core} |
474c8240 | 784 | @end smallexample |
c906108c SS |
785 | |
786 | You can, instead, specify a process ID as a second argument, if you want | |
787 | to debug a running process: | |
788 | ||
474c8240 | 789 | @smallexample |
c906108c | 790 | @value{GDBP} @var{program} 1234 |
474c8240 | 791 | @end smallexample |
c906108c SS |
792 | |
793 | @noindent | |
794 | would attach @value{GDBN} to process @code{1234} (unless you also have a file | |
795 | named @file{1234}; @value{GDBN} does check for a core file first). | |
796 | ||
c906108c | 797 | Taking advantage of the second command-line argument requires a fairly |
2df3850c JM |
798 | complete operating system; when you use @value{GDBN} as a remote |
799 | debugger attached to a bare board, there may not be any notion of | |
800 | ``process'', and there is often no way to get a core dump. @value{GDBN} | |
801 | will warn you if it is unable to attach or to read core dumps. | |
c906108c | 802 | |
aa26fa3a TT |
803 | You can optionally have @code{@value{GDBP}} pass any arguments after the |
804 | executable file to the inferior using @code{--args}. This option stops | |
805 | option processing. | |
474c8240 | 806 | @smallexample |
aa26fa3a | 807 | gdb --args gcc -O2 -c foo.c |
474c8240 | 808 | @end smallexample |
aa26fa3a TT |
809 | This will cause @code{@value{GDBP}} to debug @code{gcc}, and to set |
810 | @code{gcc}'s command-line arguments (@pxref{Arguments}) to @samp{-O2 -c foo.c}. | |
811 | ||
96a2c332 | 812 | You can run @code{@value{GDBP}} without printing the front material, which describes |
c906108c SS |
813 | @value{GDBN}'s non-warranty, by specifying @code{-silent}: |
814 | ||
815 | @smallexample | |
816 | @value{GDBP} -silent | |
817 | @end smallexample | |
818 | ||
819 | @noindent | |
820 | You can further control how @value{GDBN} starts up by using command-line | |
821 | options. @value{GDBN} itself can remind you of the options available. | |
822 | ||
823 | @noindent | |
824 | Type | |
825 | ||
474c8240 | 826 | @smallexample |
c906108c | 827 | @value{GDBP} -help |
474c8240 | 828 | @end smallexample |
c906108c SS |
829 | |
830 | @noindent | |
831 | to display all available options and briefly describe their use | |
832 | (@samp{@value{GDBP} -h} is a shorter equivalent). | |
833 | ||
834 | All options and command line arguments you give are processed | |
835 | in sequential order. The order makes a difference when the | |
836 | @samp{-x} option is used. | |
837 | ||
838 | ||
839 | @menu | |
c906108c SS |
840 | * File Options:: Choosing files |
841 | * Mode Options:: Choosing modes | |
842 | @end menu | |
843 | ||
6d2ebf8b | 844 | @node File Options |
c906108c SS |
845 | @subsection Choosing files |
846 | ||
2df3850c | 847 | When @value{GDBN} starts, it reads any arguments other than options as |
c906108c SS |
848 | specifying an executable file and core file (or process ID). This is |
849 | the same as if the arguments were specified by the @samp{-se} and | |
19837790 MS |
850 | @samp{-c} (or @samp{-p} options respectively. (@value{GDBN} reads the |
851 | first argument that does not have an associated option flag as | |
852 | equivalent to the @samp{-se} option followed by that argument; and the | |
853 | second argument that does not have an associated option flag, if any, as | |
854 | equivalent to the @samp{-c}/@samp{-p} option followed by that argument.) | |
855 | If the second argument begins with a decimal digit, @value{GDBN} will | |
856 | first attempt to attach to it as a process, and if that fails, attempt | |
857 | to open it as a corefile. If you have a corefile whose name begins with | |
858 | a digit, you can prevent @value{GDBN} from treating it as a pid by | |
79f12247 | 859 | prefixing it with @file{./}, eg. @file{./12345}. |
7a292a7a SS |
860 | |
861 | If @value{GDBN} has not been configured to included core file support, | |
862 | such as for most embedded targets, then it will complain about a second | |
863 | argument and ignore it. | |
c906108c SS |
864 | |
865 | Many options have both long and short forms; both are shown in the | |
866 | following list. @value{GDBN} also recognizes the long forms if you truncate | |
867 | them, so long as enough of the option is present to be unambiguous. | |
868 | (If you prefer, you can flag option arguments with @samp{--} rather | |
869 | than @samp{-}, though we illustrate the more usual convention.) | |
870 | ||
d700128c EZ |
871 | @c NOTE: the @cindex entries here use double dashes ON PURPOSE. This |
872 | @c way, both those who look for -foo and --foo in the index, will find | |
873 | @c it. | |
874 | ||
c906108c SS |
875 | @table @code |
876 | @item -symbols @var{file} | |
877 | @itemx -s @var{file} | |
d700128c EZ |
878 | @cindex @code{--symbols} |
879 | @cindex @code{-s} | |
c906108c SS |
880 | Read symbol table from file @var{file}. |
881 | ||
882 | @item -exec @var{file} | |
883 | @itemx -e @var{file} | |
d700128c EZ |
884 | @cindex @code{--exec} |
885 | @cindex @code{-e} | |
7a292a7a SS |
886 | Use file @var{file} as the executable file to execute when appropriate, |
887 | and for examining pure data in conjunction with a core dump. | |
c906108c SS |
888 | |
889 | @item -se @var{file} | |
d700128c | 890 | @cindex @code{--se} |
c906108c SS |
891 | Read symbol table from file @var{file} and use it as the executable |
892 | file. | |
893 | ||
c906108c SS |
894 | @item -core @var{file} |
895 | @itemx -c @var{file} | |
d700128c EZ |
896 | @cindex @code{--core} |
897 | @cindex @code{-c} | |
19837790 | 898 | Use file @var{file} as a core dump to examine. |
c906108c SS |
899 | |
900 | @item -c @var{number} | |
19837790 MS |
901 | @item -pid @var{number} |
902 | @itemx -p @var{number} | |
903 | @cindex @code{--pid} | |
904 | @cindex @code{-p} | |
905 | Connect to process ID @var{number}, as with the @code{attach} command. | |
906 | If there is no such process, @value{GDBN} will attempt to open a core | |
907 | file named @var{number}. | |
c906108c SS |
908 | |
909 | @item -command @var{file} | |
910 | @itemx -x @var{file} | |
d700128c EZ |
911 | @cindex @code{--command} |
912 | @cindex @code{-x} | |
c906108c SS |
913 | Execute @value{GDBN} commands from file @var{file}. @xref{Command |
914 | Files,, Command files}. | |
915 | ||
916 | @item -directory @var{directory} | |
917 | @itemx -d @var{directory} | |
d700128c EZ |
918 | @cindex @code{--directory} |
919 | @cindex @code{-d} | |
c906108c SS |
920 | Add @var{directory} to the path to search for source files. |
921 | ||
c906108c SS |
922 | @item -m |
923 | @itemx -mapped | |
d700128c EZ |
924 | @cindex @code{--mapped} |
925 | @cindex @code{-m} | |
c906108c SS |
926 | @emph{Warning: this option depends on operating system facilities that are not |
927 | supported on all systems.}@* | |
928 | If memory-mapped files are available on your system through the @code{mmap} | |
5d161b24 | 929 | system call, you can use this option |
c906108c SS |
930 | to have @value{GDBN} write the symbols from your |
931 | program into a reusable file in the current directory. If the program you are debugging is | |
96a2c332 | 932 | called @file{/tmp/fred}, the mapped symbol file is @file{/tmp/fred.syms}. |
c906108c SS |
933 | Future @value{GDBN} debugging sessions notice the presence of this file, |
934 | and can quickly map in symbol information from it, rather than reading | |
935 | the symbol table from the executable program. | |
936 | ||
937 | The @file{.syms} file is specific to the host machine where @value{GDBN} | |
938 | is run. It holds an exact image of the internal @value{GDBN} symbol | |
939 | table. It cannot be shared across multiple host platforms. | |
c906108c | 940 | |
c906108c SS |
941 | @item -r |
942 | @itemx -readnow | |
d700128c EZ |
943 | @cindex @code{--readnow} |
944 | @cindex @code{-r} | |
c906108c SS |
945 | Read each symbol file's entire symbol table immediately, rather than |
946 | the default, which is to read it incrementally as it is needed. | |
947 | This makes startup slower, but makes future operations faster. | |
53a5351d | 948 | |
c906108c SS |
949 | @end table |
950 | ||
2df3850c | 951 | You typically combine the @code{-mapped} and @code{-readnow} options in |
c906108c | 952 | order to build a @file{.syms} file that contains complete symbol |
2df3850c JM |
953 | information. (@xref{Files,,Commands to specify files}, for information |
954 | on @file{.syms} files.) A simple @value{GDBN} invocation to do nothing | |
955 | but build a @file{.syms} file for future use is: | |
c906108c | 956 | |
474c8240 | 957 | @smallexample |
2df3850c | 958 | gdb -batch -nx -mapped -readnow programname |
474c8240 | 959 | @end smallexample |
c906108c | 960 | |
6d2ebf8b | 961 | @node Mode Options |
c906108c SS |
962 | @subsection Choosing modes |
963 | ||
964 | You can run @value{GDBN} in various alternative modes---for example, in | |
965 | batch mode or quiet mode. | |
966 | ||
967 | @table @code | |
968 | @item -nx | |
969 | @itemx -n | |
d700128c EZ |
970 | @cindex @code{--nx} |
971 | @cindex @code{-n} | |
96565e91 | 972 | Do not execute commands found in any initialization files. Normally, |
2df3850c JM |
973 | @value{GDBN} executes the commands in these files after all the command |
974 | options and arguments have been processed. @xref{Command Files,,Command | |
975 | files}. | |
c906108c SS |
976 | |
977 | @item -quiet | |
d700128c | 978 | @itemx -silent |
c906108c | 979 | @itemx -q |
d700128c EZ |
980 | @cindex @code{--quiet} |
981 | @cindex @code{--silent} | |
982 | @cindex @code{-q} | |
c906108c SS |
983 | ``Quiet''. Do not print the introductory and copyright messages. These |
984 | messages are also suppressed in batch mode. | |
985 | ||
986 | @item -batch | |
d700128c | 987 | @cindex @code{--batch} |
c906108c SS |
988 | Run in batch mode. Exit with status @code{0} after processing all the |
989 | command files specified with @samp{-x} (and all commands from | |
990 | initialization files, if not inhibited with @samp{-n}). Exit with | |
991 | nonzero status if an error occurs in executing the @value{GDBN} commands | |
992 | in the command files. | |
993 | ||
2df3850c JM |
994 | Batch mode may be useful for running @value{GDBN} as a filter, for |
995 | example to download and run a program on another computer; in order to | |
996 | make this more useful, the message | |
c906108c | 997 | |
474c8240 | 998 | @smallexample |
c906108c | 999 | Program exited normally. |
474c8240 | 1000 | @end smallexample |
c906108c SS |
1001 | |
1002 | @noindent | |
2df3850c JM |
1003 | (which is ordinarily issued whenever a program running under |
1004 | @value{GDBN} control terminates) is not issued when running in batch | |
1005 | mode. | |
1006 | ||
1007 | @item -nowindows | |
1008 | @itemx -nw | |
d700128c EZ |
1009 | @cindex @code{--nowindows} |
1010 | @cindex @code{-nw} | |
2df3850c | 1011 | ``No windows''. If @value{GDBN} comes with a graphical user interface |
96a2c332 | 1012 | (GUI) built in, then this option tells @value{GDBN} to only use the command-line |
2df3850c JM |
1013 | interface. If no GUI is available, this option has no effect. |
1014 | ||
1015 | @item -windows | |
1016 | @itemx -w | |
d700128c EZ |
1017 | @cindex @code{--windows} |
1018 | @cindex @code{-w} | |
2df3850c JM |
1019 | If @value{GDBN} includes a GUI, then this option requires it to be |
1020 | used if possible. | |
c906108c SS |
1021 | |
1022 | @item -cd @var{directory} | |
d700128c | 1023 | @cindex @code{--cd} |
c906108c SS |
1024 | Run @value{GDBN} using @var{directory} as its working directory, |
1025 | instead of the current directory. | |
1026 | ||
c906108c SS |
1027 | @item -fullname |
1028 | @itemx -f | |
d700128c EZ |
1029 | @cindex @code{--fullname} |
1030 | @cindex @code{-f} | |
7a292a7a SS |
1031 | @sc{gnu} Emacs sets this option when it runs @value{GDBN} as a |
1032 | subprocess. It tells @value{GDBN} to output the full file name and line | |
1033 | number in a standard, recognizable fashion each time a stack frame is | |
1034 | displayed (which includes each time your program stops). This | |
1035 | recognizable format looks like two @samp{\032} characters, followed by | |
1036 | the file name, line number and character position separated by colons, | |
1037 | and a newline. The Emacs-to-@value{GDBN} interface program uses the two | |
1038 | @samp{\032} characters as a signal to display the source code for the | |
1039 | frame. | |
c906108c | 1040 | |
d700128c EZ |
1041 | @item -epoch |
1042 | @cindex @code{--epoch} | |
1043 | The Epoch Emacs-@value{GDBN} interface sets this option when it runs | |
1044 | @value{GDBN} as a subprocess. It tells @value{GDBN} to modify its print | |
1045 | routines so as to allow Epoch to display values of expressions in a | |
1046 | separate window. | |
1047 | ||
1048 | @item -annotate @var{level} | |
1049 | @cindex @code{--annotate} | |
1050 | This option sets the @dfn{annotation level} inside @value{GDBN}. Its | |
1051 | effect is identical to using @samp{set annotate @var{level}} | |
1052 | (@pxref{Annotations}). | |
1053 | Annotation level controls how much information does @value{GDBN} print | |
1054 | together with its prompt, values of expressions, source lines, and other | |
1055 | types of output. Level 0 is the normal, level 1 is for use when | |
1056 | @value{GDBN} is run as a subprocess of @sc{gnu} Emacs, level 2 is the | |
1057 | maximum annotation suitable for programs that control @value{GDBN}. | |
1058 | ||
1059 | @item -async | |
1060 | @cindex @code{--async} | |
1061 | Use the asynchronous event loop for the command-line interface. | |
1062 | @value{GDBN} processes all events, such as user keyboard input, via a | |
1063 | special event loop. This allows @value{GDBN} to accept and process user | |
1064 | commands in parallel with the debugged process being | |
1065 | run@footnote{@value{GDBN} built with @sc{djgpp} tools for | |
1066 | MS-DOS/MS-Windows supports this mode of operation, but the event loop is | |
1067 | suspended when the debuggee runs.}, so you don't need to wait for | |
1068 | control to return to @value{GDBN} before you type the next command. | |
b37052ae | 1069 | (@emph{Note:} as of version 5.1, the target side of the asynchronous |
d700128c EZ |
1070 | operation is not yet in place, so @samp{-async} does not work fully |
1071 | yet.) | |
1072 | @c FIXME: when the target side of the event loop is done, the above NOTE | |
1073 | @c should be removed. | |
1074 | ||
1075 | When the standard input is connected to a terminal device, @value{GDBN} | |
1076 | uses the asynchronous event loop by default, unless disabled by the | |
1077 | @samp{-noasync} option. | |
1078 | ||
1079 | @item -noasync | |
1080 | @cindex @code{--noasync} | |
1081 | Disable the asynchronous event loop for the command-line interface. | |
1082 | ||
aa26fa3a TT |
1083 | @item --args |
1084 | @cindex @code{--args} | |
1085 | Change interpretation of command line so that arguments following the | |
1086 | executable file are passed as command line arguments to the inferior. | |
1087 | This option stops option processing. | |
1088 | ||
2df3850c JM |
1089 | @item -baud @var{bps} |
1090 | @itemx -b @var{bps} | |
d700128c EZ |
1091 | @cindex @code{--baud} |
1092 | @cindex @code{-b} | |
c906108c SS |
1093 | Set the line speed (baud rate or bits per second) of any serial |
1094 | interface used by @value{GDBN} for remote debugging. | |
c906108c SS |
1095 | |
1096 | @item -tty @var{device} | |
d700128c EZ |
1097 | @itemx -t @var{device} |
1098 | @cindex @code{--tty} | |
1099 | @cindex @code{-t} | |
c906108c SS |
1100 | Run using @var{device} for your program's standard input and output. |
1101 | @c FIXME: kingdon thinks there is more to -tty. Investigate. | |
c906108c | 1102 | |
53a5351d | 1103 | @c resolve the situation of these eventually |
c4555f82 SC |
1104 | @item -tui |
1105 | @cindex @code{--tui} | |
1106 | Activate the Terminal User Interface when starting. | |
1107 | The Terminal User Interface manages several text windows on the terminal, | |
1108 | showing source, assembly, registers and @value{GDBN} command outputs | |
1109 | (@pxref{TUI, ,@value{GDBN} Text User Interface}). | |
1110 | Do not use this option if you run @value{GDBN} from Emacs | |
1111 | (@pxref{Emacs, ,Using @value{GDBN} under @sc{gnu} Emacs}). | |
53a5351d JM |
1112 | |
1113 | @c @item -xdb | |
d700128c | 1114 | @c @cindex @code{--xdb} |
53a5351d JM |
1115 | @c Run in XDB compatibility mode, allowing the use of certain XDB commands. |
1116 | @c For information, see the file @file{xdb_trans.html}, which is usually | |
1117 | @c installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX | |
1118 | @c systems. | |
1119 | ||
d700128c EZ |
1120 | @item -interpreter @var{interp} |
1121 | @cindex @code{--interpreter} | |
1122 | Use the interpreter @var{interp} for interface with the controlling | |
1123 | program or device. This option is meant to be set by programs which | |
94bbb2c0 | 1124 | communicate with @value{GDBN} using it as a back end. |
21c294e6 | 1125 | @xref{Interpreters, , Command Interpreters}. |
94bbb2c0 | 1126 | |
da0f9dcd AC |
1127 | @samp{--interpreter=mi} (or @samp{--interpreter=mi2}) causes |
1128 | @value{GDBN} to use the current @dfn{@sc{gdb/mi} interface} | |
1129 | (@pxref{GDB/MI, , The @sc{gdb/mi} Interface}). The previous @sc{gdb/mi} | |
1130 | interface, included in @value{GDBN} version 5.3, can be selected with | |
1131 | @samp{--interpreter=mi1}. Earlier @sc{gdb/mi} interfaces | |
1132 | are not supported. | |
d700128c EZ |
1133 | |
1134 | @item -write | |
1135 | @cindex @code{--write} | |
1136 | Open the executable and core files for both reading and writing. This | |
1137 | is equivalent to the @samp{set write on} command inside @value{GDBN} | |
1138 | (@pxref{Patching}). | |
1139 | ||
1140 | @item -statistics | |
1141 | @cindex @code{--statistics} | |
1142 | This option causes @value{GDBN} to print statistics about time and | |
1143 | memory usage after it completes each command and returns to the prompt. | |
1144 | ||
1145 | @item -version | |
1146 | @cindex @code{--version} | |
1147 | This option causes @value{GDBN} to print its version number and | |
1148 | no-warranty blurb, and exit. | |
1149 | ||
c906108c SS |
1150 | @end table |
1151 | ||
6d2ebf8b | 1152 | @node Quitting GDB |
c906108c SS |
1153 | @section Quitting @value{GDBN} |
1154 | @cindex exiting @value{GDBN} | |
1155 | @cindex leaving @value{GDBN} | |
1156 | ||
1157 | @table @code | |
1158 | @kindex quit @r{[}@var{expression}@r{]} | |
41afff9a | 1159 | @kindex q @r{(@code{quit})} |
96a2c332 SS |
1160 | @item quit @r{[}@var{expression}@r{]} |
1161 | @itemx q | |
1162 | To exit @value{GDBN}, use the @code{quit} command (abbreviated | |
1163 | @code{q}), or type an end-of-file character (usually @kbd{C-d}). If you | |
1164 | do not supply @var{expression}, @value{GDBN} will terminate normally; | |
1165 | otherwise it will terminate using the result of @var{expression} as the | |
1166 | error code. | |
c906108c SS |
1167 | @end table |
1168 | ||
1169 | @cindex interrupt | |
1170 | An interrupt (often @kbd{C-c}) does not exit from @value{GDBN}, but rather | |
1171 | terminates the action of any @value{GDBN} command that is in progress and | |
1172 | returns to @value{GDBN} command level. It is safe to type the interrupt | |
1173 | character at any time because @value{GDBN} does not allow it to take effect | |
1174 | until a time when it is safe. | |
1175 | ||
c906108c SS |
1176 | If you have been using @value{GDBN} to control an attached process or |
1177 | device, you can release it with the @code{detach} command | |
1178 | (@pxref{Attach, ,Debugging an already-running process}). | |
c906108c | 1179 | |
6d2ebf8b | 1180 | @node Shell Commands |
c906108c SS |
1181 | @section Shell commands |
1182 | ||
1183 | If you need to execute occasional shell commands during your | |
1184 | debugging session, there is no need to leave or suspend @value{GDBN}; you can | |
1185 | just use the @code{shell} command. | |
1186 | ||
1187 | @table @code | |
1188 | @kindex shell | |
1189 | @cindex shell escape | |
1190 | @item shell @var{command string} | |
1191 | Invoke a standard shell to execute @var{command string}. | |
c906108c | 1192 | If it exists, the environment variable @code{SHELL} determines which |
d4f3574e SS |
1193 | shell to run. Otherwise @value{GDBN} uses the default shell |
1194 | (@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.). | |
c906108c SS |
1195 | @end table |
1196 | ||
1197 | The utility @code{make} is often needed in development environments. | |
1198 | You do not have to use the @code{shell} command for this purpose in | |
1199 | @value{GDBN}: | |
1200 | ||
1201 | @table @code | |
1202 | @kindex make | |
1203 | @cindex calling make | |
1204 | @item make @var{make-args} | |
1205 | Execute the @code{make} program with the specified | |
1206 | arguments. This is equivalent to @samp{shell make @var{make-args}}. | |
1207 | @end table | |
1208 | ||
6d2ebf8b | 1209 | @node Commands |
c906108c SS |
1210 | @chapter @value{GDBN} Commands |
1211 | ||
1212 | You can abbreviate a @value{GDBN} command to the first few letters of the command | |
1213 | name, if that abbreviation is unambiguous; and you can repeat certain | |
1214 | @value{GDBN} commands by typing just @key{RET}. You can also use the @key{TAB} | |
1215 | key to get @value{GDBN} to fill out the rest of a word in a command (or to | |
1216 | show you the alternatives available, if there is more than one possibility). | |
1217 | ||
1218 | @menu | |
1219 | * Command Syntax:: How to give commands to @value{GDBN} | |
1220 | * Completion:: Command completion | |
1221 | * Help:: How to ask @value{GDBN} for help | |
1222 | @end menu | |
1223 | ||
6d2ebf8b | 1224 | @node Command Syntax |
c906108c SS |
1225 | @section Command syntax |
1226 | ||
1227 | A @value{GDBN} command is a single line of input. There is no limit on | |
1228 | how long it can be. It starts with a command name, which is followed by | |
1229 | arguments whose meaning depends on the command name. For example, the | |
1230 | command @code{step} accepts an argument which is the number of times to | |
1231 | step, as in @samp{step 5}. You can also use the @code{step} command | |
96a2c332 | 1232 | with no arguments. Some commands do not allow any arguments. |
c906108c SS |
1233 | |
1234 | @cindex abbreviation | |
1235 | @value{GDBN} command names may always be truncated if that abbreviation is | |
1236 | unambiguous. Other possible command abbreviations are listed in the | |
1237 | documentation for individual commands. In some cases, even ambiguous | |
1238 | abbreviations are allowed; for example, @code{s} is specially defined as | |
1239 | equivalent to @code{step} even though there are other commands whose | |
1240 | names start with @code{s}. You can test abbreviations by using them as | |
1241 | arguments to the @code{help} command. | |
1242 | ||
1243 | @cindex repeating commands | |
41afff9a | 1244 | @kindex RET @r{(repeat last command)} |
c906108c | 1245 | A blank line as input to @value{GDBN} (typing just @key{RET}) means to |
96a2c332 | 1246 | repeat the previous command. Certain commands (for example, @code{run}) |
c906108c SS |
1247 | will not repeat this way; these are commands whose unintentional |
1248 | repetition might cause trouble and which you are unlikely to want to | |
1249 | repeat. | |
1250 | ||
1251 | The @code{list} and @code{x} commands, when you repeat them with | |
1252 | @key{RET}, construct new arguments rather than repeating | |
1253 | exactly as typed. This permits easy scanning of source or memory. | |
1254 | ||
1255 | @value{GDBN} can also use @key{RET} in another way: to partition lengthy | |
1256 | output, in a way similar to the common utility @code{more} | |
1257 | (@pxref{Screen Size,,Screen size}). Since it is easy to press one | |
1258 | @key{RET} too many in this situation, @value{GDBN} disables command | |
1259 | repetition after any command that generates this sort of display. | |
1260 | ||
41afff9a | 1261 | @kindex # @r{(a comment)} |
c906108c SS |
1262 | @cindex comment |
1263 | Any text from a @kbd{#} to the end of the line is a comment; it does | |
1264 | nothing. This is useful mainly in command files (@pxref{Command | |
1265 | Files,,Command files}). | |
1266 | ||
88118b3a TT |
1267 | @cindex repeating command sequences |
1268 | @kindex C-o @r{(operate-and-get-next)} | |
1269 | The @kbd{C-o} binding is useful for repeating a complex sequence of | |
1270 | commands. This command accepts the current line, like @kbd{RET}, and | |
1271 | then fetches the next line relative to the current line from the history | |
1272 | for editing. | |
1273 | ||
6d2ebf8b | 1274 | @node Completion |
c906108c SS |
1275 | @section Command completion |
1276 | ||
1277 | @cindex completion | |
1278 | @cindex word completion | |
1279 | @value{GDBN} can fill in the rest of a word in a command for you, if there is | |
1280 | only one possibility; it can also show you what the valid possibilities | |
1281 | are for the next word in a command, at any time. This works for @value{GDBN} | |
1282 | commands, @value{GDBN} subcommands, and the names of symbols in your program. | |
1283 | ||
1284 | Press the @key{TAB} key whenever you want @value{GDBN} to fill out the rest | |
1285 | of a word. If there is only one possibility, @value{GDBN} fills in the | |
1286 | word, and waits for you to finish the command (or press @key{RET} to | |
1287 | enter it). For example, if you type | |
1288 | ||
1289 | @c FIXME "@key" does not distinguish its argument sufficiently to permit | |
1290 | @c complete accuracy in these examples; space introduced for clarity. | |
1291 | @c If texinfo enhancements make it unnecessary, it would be nice to | |
1292 | @c replace " @key" by "@key" in the following... | |
474c8240 | 1293 | @smallexample |
c906108c | 1294 | (@value{GDBP}) info bre @key{TAB} |
474c8240 | 1295 | @end smallexample |
c906108c SS |
1296 | |
1297 | @noindent | |
1298 | @value{GDBN} fills in the rest of the word @samp{breakpoints}, since that is | |
1299 | the only @code{info} subcommand beginning with @samp{bre}: | |
1300 | ||
474c8240 | 1301 | @smallexample |
c906108c | 1302 | (@value{GDBP}) info breakpoints |
474c8240 | 1303 | @end smallexample |
c906108c SS |
1304 | |
1305 | @noindent | |
1306 | You can either press @key{RET} at this point, to run the @code{info | |
1307 | breakpoints} command, or backspace and enter something else, if | |
1308 | @samp{breakpoints} does not look like the command you expected. (If you | |
1309 | were sure you wanted @code{info breakpoints} in the first place, you | |
1310 | might as well just type @key{RET} immediately after @samp{info bre}, | |
1311 | to exploit command abbreviations rather than command completion). | |
1312 | ||
1313 | If there is more than one possibility for the next word when you press | |
1314 | @key{TAB}, @value{GDBN} sounds a bell. You can either supply more | |
1315 | characters and try again, or just press @key{TAB} a second time; | |
1316 | @value{GDBN} displays all the possible completions for that word. For | |
1317 | example, you might want to set a breakpoint on a subroutine whose name | |
1318 | begins with @samp{make_}, but when you type @kbd{b make_@key{TAB}} @value{GDBN} | |
1319 | just sounds the bell. Typing @key{TAB} again displays all the | |
1320 | function names in your program that begin with those characters, for | |
1321 | example: | |
1322 | ||
474c8240 | 1323 | @smallexample |
c906108c SS |
1324 | (@value{GDBP}) b make_ @key{TAB} |
1325 | @exdent @value{GDBN} sounds bell; press @key{TAB} again, to see: | |
5d161b24 DB |
1326 | make_a_section_from_file make_environ |
1327 | make_abs_section make_function_type | |
1328 | make_blockvector make_pointer_type | |
1329 | make_cleanup make_reference_type | |
c906108c SS |
1330 | make_command make_symbol_completion_list |
1331 | (@value{GDBP}) b make_ | |
474c8240 | 1332 | @end smallexample |
c906108c SS |
1333 | |
1334 | @noindent | |
1335 | After displaying the available possibilities, @value{GDBN} copies your | |
1336 | partial input (@samp{b make_} in the example) so you can finish the | |
1337 | command. | |
1338 | ||
1339 | If you just want to see the list of alternatives in the first place, you | |
b37052ae | 1340 | can press @kbd{M-?} rather than pressing @key{TAB} twice. @kbd{M-?} |
7a292a7a | 1341 | means @kbd{@key{META} ?}. You can type this either by holding down a |
c906108c | 1342 | key designated as the @key{META} shift on your keyboard (if there is |
7a292a7a | 1343 | one) while typing @kbd{?}, or as @key{ESC} followed by @kbd{?}. |
c906108c SS |
1344 | |
1345 | @cindex quotes in commands | |
1346 | @cindex completion of quoted strings | |
1347 | Sometimes the string you need, while logically a ``word'', may contain | |
7a292a7a SS |
1348 | parentheses or other characters that @value{GDBN} normally excludes from |
1349 | its notion of a word. To permit word completion to work in this | |
1350 | situation, you may enclose words in @code{'} (single quote marks) in | |
1351 | @value{GDBN} commands. | |
c906108c | 1352 | |
c906108c | 1353 | The most likely situation where you might need this is in typing the |
b37052ae EZ |
1354 | name of a C@t{++} function. This is because C@t{++} allows function |
1355 | overloading (multiple definitions of the same function, distinguished | |
1356 | by argument type). For example, when you want to set a breakpoint you | |
1357 | may need to distinguish whether you mean the version of @code{name} | |
1358 | that takes an @code{int} parameter, @code{name(int)}, or the version | |
1359 | that takes a @code{float} parameter, @code{name(float)}. To use the | |
1360 | word-completion facilities in this situation, type a single quote | |
1361 | @code{'} at the beginning of the function name. This alerts | |
1362 | @value{GDBN} that it may need to consider more information than usual | |
1363 | when you press @key{TAB} or @kbd{M-?} to request word completion: | |
c906108c | 1364 | |
474c8240 | 1365 | @smallexample |
96a2c332 | 1366 | (@value{GDBP}) b 'bubble( @kbd{M-?} |
c906108c SS |
1367 | bubble(double,double) bubble(int,int) |
1368 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1369 | @end smallexample |
c906108c SS |
1370 | |
1371 | In some cases, @value{GDBN} can tell that completing a name requires using | |
1372 | quotes. When this happens, @value{GDBN} inserts the quote for you (while | |
1373 | completing as much as it can) if you do not type the quote in the first | |
1374 | place: | |
1375 | ||
474c8240 | 1376 | @smallexample |
c906108c SS |
1377 | (@value{GDBP}) b bub @key{TAB} |
1378 | @exdent @value{GDBN} alters your input line to the following, and rings a bell: | |
1379 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1380 | @end smallexample |
c906108c SS |
1381 | |
1382 | @noindent | |
1383 | In general, @value{GDBN} can tell that a quote is needed (and inserts it) if | |
1384 | you have not yet started typing the argument list when you ask for | |
1385 | completion on an overloaded symbol. | |
1386 | ||
d4f3574e | 1387 | For more information about overloaded functions, see @ref{C plus plus |
b37052ae | 1388 | expressions, ,C@t{++} expressions}. You can use the command @code{set |
c906108c | 1389 | overload-resolution off} to disable overload resolution; |
b37052ae | 1390 | see @ref{Debugging C plus plus, ,@value{GDBN} features for C@t{++}}. |
c906108c SS |
1391 | |
1392 | ||
6d2ebf8b | 1393 | @node Help |
c906108c SS |
1394 | @section Getting help |
1395 | @cindex online documentation | |
1396 | @kindex help | |
1397 | ||
5d161b24 | 1398 | You can always ask @value{GDBN} itself for information on its commands, |
c906108c SS |
1399 | using the command @code{help}. |
1400 | ||
1401 | @table @code | |
41afff9a | 1402 | @kindex h @r{(@code{help})} |
c906108c SS |
1403 | @item help |
1404 | @itemx h | |
1405 | You can use @code{help} (abbreviated @code{h}) with no arguments to | |
1406 | display a short list of named classes of commands: | |
1407 | ||
1408 | @smallexample | |
1409 | (@value{GDBP}) help | |
1410 | List of classes of commands: | |
1411 | ||
2df3850c | 1412 | aliases -- Aliases of other commands |
c906108c | 1413 | breakpoints -- Making program stop at certain points |
2df3850c | 1414 | data -- Examining data |
c906108c | 1415 | files -- Specifying and examining files |
2df3850c JM |
1416 | internals -- Maintenance commands |
1417 | obscure -- Obscure features | |
1418 | running -- Running the program | |
1419 | stack -- Examining the stack | |
c906108c SS |
1420 | status -- Status inquiries |
1421 | support -- Support facilities | |
96a2c332 SS |
1422 | tracepoints -- Tracing of program execution without@* |
1423 | stopping the program | |
c906108c | 1424 | user-defined -- User-defined commands |
c906108c | 1425 | |
5d161b24 | 1426 | Type "help" followed by a class name for a list of |
c906108c | 1427 | commands in that class. |
5d161b24 | 1428 | Type "help" followed by command name for full |
c906108c SS |
1429 | documentation. |
1430 | Command name abbreviations are allowed if unambiguous. | |
1431 | (@value{GDBP}) | |
1432 | @end smallexample | |
96a2c332 | 1433 | @c the above line break eliminates huge line overfull... |
c906108c SS |
1434 | |
1435 | @item help @var{class} | |
1436 | Using one of the general help classes as an argument, you can get a | |
1437 | list of the individual commands in that class. For example, here is the | |
1438 | help display for the class @code{status}: | |
1439 | ||
1440 | @smallexample | |
1441 | (@value{GDBP}) help status | |
1442 | Status inquiries. | |
1443 | ||
1444 | List of commands: | |
1445 | ||
1446 | @c Line break in "show" line falsifies real output, but needed | |
1447 | @c to fit in smallbook page size. | |
2df3850c JM |
1448 | info -- Generic command for showing things |
1449 | about the program being debugged | |
1450 | show -- Generic command for showing things | |
1451 | about the debugger | |
c906108c | 1452 | |
5d161b24 | 1453 | Type "help" followed by command name for full |
c906108c SS |
1454 | documentation. |
1455 | Command name abbreviations are allowed if unambiguous. | |
1456 | (@value{GDBP}) | |
1457 | @end smallexample | |
1458 | ||
1459 | @item help @var{command} | |
1460 | With a command name as @code{help} argument, @value{GDBN} displays a | |
1461 | short paragraph on how to use that command. | |
1462 | ||
6837a0a2 DB |
1463 | @kindex apropos |
1464 | @item apropos @var{args} | |
1465 | The @code{apropos @var{args}} command searches through all of the @value{GDBN} | |
1466 | commands, and their documentation, for the regular expression specified in | |
1467 | @var{args}. It prints out all matches found. For example: | |
1468 | ||
1469 | @smallexample | |
1470 | apropos reload | |
1471 | @end smallexample | |
1472 | ||
b37052ae EZ |
1473 | @noindent |
1474 | results in: | |
6837a0a2 DB |
1475 | |
1476 | @smallexample | |
6d2ebf8b SS |
1477 | @c @group |
1478 | set symbol-reloading -- Set dynamic symbol table reloading | |
1479 | multiple times in one run | |
1480 | show symbol-reloading -- Show dynamic symbol table reloading | |
1481 | multiple times in one run | |
1482 | @c @end group | |
6837a0a2 DB |
1483 | @end smallexample |
1484 | ||
c906108c SS |
1485 | @kindex complete |
1486 | @item complete @var{args} | |
1487 | The @code{complete @var{args}} command lists all the possible completions | |
1488 | for the beginning of a command. Use @var{args} to specify the beginning of the | |
1489 | command you want completed. For example: | |
1490 | ||
1491 | @smallexample | |
1492 | complete i | |
1493 | @end smallexample | |
1494 | ||
1495 | @noindent results in: | |
1496 | ||
1497 | @smallexample | |
1498 | @group | |
2df3850c JM |
1499 | if |
1500 | ignore | |
c906108c SS |
1501 | info |
1502 | inspect | |
c906108c SS |
1503 | @end group |
1504 | @end smallexample | |
1505 | ||
1506 | @noindent This is intended for use by @sc{gnu} Emacs. | |
1507 | @end table | |
1508 | ||
1509 | In addition to @code{help}, you can use the @value{GDBN} commands @code{info} | |
1510 | and @code{show} to inquire about the state of your program, or the state | |
1511 | of @value{GDBN} itself. Each command supports many topics of inquiry; this | |
1512 | manual introduces each of them in the appropriate context. The listings | |
1513 | under @code{info} and under @code{show} in the Index point to | |
1514 | all the sub-commands. @xref{Index}. | |
1515 | ||
1516 | @c @group | |
1517 | @table @code | |
1518 | @kindex info | |
41afff9a | 1519 | @kindex i @r{(@code{info})} |
c906108c SS |
1520 | @item info |
1521 | This command (abbreviated @code{i}) is for describing the state of your | |
1522 | program. For example, you can list the arguments given to your program | |
1523 | with @code{info args}, list the registers currently in use with @code{info | |
1524 | registers}, or list the breakpoints you have set with @code{info breakpoints}. | |
1525 | You can get a complete list of the @code{info} sub-commands with | |
1526 | @w{@code{help info}}. | |
1527 | ||
1528 | @kindex set | |
1529 | @item set | |
5d161b24 | 1530 | You can assign the result of an expression to an environment variable with |
c906108c SS |
1531 | @code{set}. For example, you can set the @value{GDBN} prompt to a $-sign with |
1532 | @code{set prompt $}. | |
1533 | ||
1534 | @kindex show | |
1535 | @item show | |
5d161b24 | 1536 | In contrast to @code{info}, @code{show} is for describing the state of |
c906108c SS |
1537 | @value{GDBN} itself. |
1538 | You can change most of the things you can @code{show}, by using the | |
1539 | related command @code{set}; for example, you can control what number | |
1540 | system is used for displays with @code{set radix}, or simply inquire | |
1541 | which is currently in use with @code{show radix}. | |
1542 | ||
1543 | @kindex info set | |
1544 | To display all the settable parameters and their current | |
1545 | values, you can use @code{show} with no arguments; you may also use | |
1546 | @code{info set}. Both commands produce the same display. | |
1547 | @c FIXME: "info set" violates the rule that "info" is for state of | |
1548 | @c FIXME...program. Ck w/ GNU: "info set" to be called something else, | |
1549 | @c FIXME...or change desc of rule---eg "state of prog and debugging session"? | |
1550 | @end table | |
1551 | @c @end group | |
1552 | ||
1553 | Here are three miscellaneous @code{show} subcommands, all of which are | |
1554 | exceptional in lacking corresponding @code{set} commands: | |
1555 | ||
1556 | @table @code | |
1557 | @kindex show version | |
1558 | @cindex version number | |
1559 | @item show version | |
1560 | Show what version of @value{GDBN} is running. You should include this | |
2df3850c JM |
1561 | information in @value{GDBN} bug-reports. If multiple versions of |
1562 | @value{GDBN} are in use at your site, you may need to determine which | |
1563 | version of @value{GDBN} you are running; as @value{GDBN} evolves, new | |
1564 | commands are introduced, and old ones may wither away. Also, many | |
1565 | system vendors ship variant versions of @value{GDBN}, and there are | |
96a2c332 | 1566 | variant versions of @value{GDBN} in @sc{gnu}/Linux distributions as well. |
2df3850c JM |
1567 | The version number is the same as the one announced when you start |
1568 | @value{GDBN}. | |
c906108c SS |
1569 | |
1570 | @kindex show copying | |
1571 | @item show copying | |
1572 | Display information about permission for copying @value{GDBN}. | |
1573 | ||
1574 | @kindex show warranty | |
1575 | @item show warranty | |
2df3850c | 1576 | Display the @sc{gnu} ``NO WARRANTY'' statement, or a warranty, |
96a2c332 | 1577 | if your version of @value{GDBN} comes with one. |
2df3850c | 1578 | |
c906108c SS |
1579 | @end table |
1580 | ||
6d2ebf8b | 1581 | @node Running |
c906108c SS |
1582 | @chapter Running Programs Under @value{GDBN} |
1583 | ||
1584 | When you run a program under @value{GDBN}, you must first generate | |
1585 | debugging information when you compile it. | |
7a292a7a SS |
1586 | |
1587 | You may start @value{GDBN} with its arguments, if any, in an environment | |
1588 | of your choice. If you are doing native debugging, you may redirect | |
1589 | your program's input and output, debug an already running process, or | |
1590 | kill a child process. | |
c906108c SS |
1591 | |
1592 | @menu | |
1593 | * Compilation:: Compiling for debugging | |
1594 | * Starting:: Starting your program | |
c906108c SS |
1595 | * Arguments:: Your program's arguments |
1596 | * Environment:: Your program's environment | |
c906108c SS |
1597 | |
1598 | * Working Directory:: Your program's working directory | |
1599 | * Input/Output:: Your program's input and output | |
1600 | * Attach:: Debugging an already-running process | |
1601 | * Kill Process:: Killing the child process | |
c906108c SS |
1602 | |
1603 | * Threads:: Debugging programs with multiple threads | |
1604 | * Processes:: Debugging programs with multiple processes | |
1605 | @end menu | |
1606 | ||
6d2ebf8b | 1607 | @node Compilation |
c906108c SS |
1608 | @section Compiling for debugging |
1609 | ||
1610 | In order to debug a program effectively, you need to generate | |
1611 | debugging information when you compile it. This debugging information | |
1612 | is stored in the object file; it describes the data type of each | |
1613 | variable or function and the correspondence between source line numbers | |
1614 | and addresses in the executable code. | |
1615 | ||
1616 | To request debugging information, specify the @samp{-g} option when you run | |
1617 | the compiler. | |
1618 | ||
e2e0bcd1 JB |
1619 | Most compilers do not include information about preprocessor macros in |
1620 | the debugging information if you specify the @option{-g} flag alone, | |
1621 | because this information is rather large. Version 3.1 of @value{NGCC}, | |
1622 | the @sc{gnu} C compiler, provides macro information if you specify the | |
1623 | options @option{-gdwarf-2} and @option{-g3}; the former option requests | |
1624 | debugging information in the Dwarf 2 format, and the latter requests | |
1625 | ``extra information''. In the future, we hope to find more compact ways | |
1626 | to represent macro information, so that it can be included with | |
1627 | @option{-g} alone. | |
1628 | ||
c906108c SS |
1629 | Many C compilers are unable to handle the @samp{-g} and @samp{-O} |
1630 | options together. Using those compilers, you cannot generate optimized | |
1631 | executables containing debugging information. | |
1632 | ||
53a5351d JM |
1633 | @value{NGCC}, the @sc{gnu} C compiler, supports @samp{-g} with or |
1634 | without @samp{-O}, making it possible to debug optimized code. We | |
1635 | recommend that you @emph{always} use @samp{-g} whenever you compile a | |
1636 | program. You may think your program is correct, but there is no sense | |
1637 | in pushing your luck. | |
c906108c SS |
1638 | |
1639 | @cindex optimized code, debugging | |
1640 | @cindex debugging optimized code | |
1641 | When you debug a program compiled with @samp{-g -O}, remember that the | |
1642 | optimizer is rearranging your code; the debugger shows you what is | |
1643 | really there. Do not be too surprised when the execution path does not | |
1644 | exactly match your source file! An extreme example: if you define a | |
1645 | variable, but never use it, @value{GDBN} never sees that | |
1646 | variable---because the compiler optimizes it out of existence. | |
1647 | ||
1648 | Some things do not work as well with @samp{-g -O} as with just | |
1649 | @samp{-g}, particularly on machines with instruction scheduling. If in | |
1650 | doubt, recompile with @samp{-g} alone, and if this fixes the problem, | |
1651 | please report it to us as a bug (including a test case!). | |
1652 | ||
1653 | Older versions of the @sc{gnu} C compiler permitted a variant option | |
1654 | @w{@samp{-gg}} for debugging information. @value{GDBN} no longer supports this | |
1655 | format; if your @sc{gnu} C compiler has this option, do not use it. | |
1656 | ||
1657 | @need 2000 | |
6d2ebf8b | 1658 | @node Starting |
c906108c SS |
1659 | @section Starting your program |
1660 | @cindex starting | |
1661 | @cindex running | |
1662 | ||
1663 | @table @code | |
1664 | @kindex run | |
41afff9a | 1665 | @kindex r @r{(@code{run})} |
c906108c SS |
1666 | @item run |
1667 | @itemx r | |
7a292a7a SS |
1668 | Use the @code{run} command to start your program under @value{GDBN}. |
1669 | You must first specify the program name (except on VxWorks) with an | |
1670 | argument to @value{GDBN} (@pxref{Invocation, ,Getting In and Out of | |
1671 | @value{GDBN}}), or by using the @code{file} or @code{exec-file} command | |
1672 | (@pxref{Files, ,Commands to specify files}). | |
c906108c SS |
1673 | |
1674 | @end table | |
1675 | ||
c906108c SS |
1676 | If you are running your program in an execution environment that |
1677 | supports processes, @code{run} creates an inferior process and makes | |
1678 | that process run your program. (In environments without processes, | |
1679 | @code{run} jumps to the start of your program.) | |
1680 | ||
1681 | The execution of a program is affected by certain information it | |
1682 | receives from its superior. @value{GDBN} provides ways to specify this | |
1683 | information, which you must do @emph{before} starting your program. (You | |
1684 | can change it after starting your program, but such changes only affect | |
1685 | your program the next time you start it.) This information may be | |
1686 | divided into four categories: | |
1687 | ||
1688 | @table @asis | |
1689 | @item The @emph{arguments.} | |
1690 | Specify the arguments to give your program as the arguments of the | |
1691 | @code{run} command. If a shell is available on your target, the shell | |
1692 | is used to pass the arguments, so that you may use normal conventions | |
1693 | (such as wildcard expansion or variable substitution) in describing | |
1694 | the arguments. | |
1695 | In Unix systems, you can control which shell is used with the | |
1696 | @code{SHELL} environment variable. | |
1697 | @xref{Arguments, ,Your program's arguments}. | |
1698 | ||
1699 | @item The @emph{environment.} | |
1700 | Your program normally inherits its environment from @value{GDBN}, but you can | |
1701 | use the @value{GDBN} commands @code{set environment} and @code{unset | |
1702 | environment} to change parts of the environment that affect | |
1703 | your program. @xref{Environment, ,Your program's environment}. | |
1704 | ||
1705 | @item The @emph{working directory.} | |
1706 | Your program inherits its working directory from @value{GDBN}. You can set | |
1707 | the @value{GDBN} working directory with the @code{cd} command in @value{GDBN}. | |
1708 | @xref{Working Directory, ,Your program's working directory}. | |
1709 | ||
1710 | @item The @emph{standard input and output.} | |
1711 | Your program normally uses the same device for standard input and | |
1712 | standard output as @value{GDBN} is using. You can redirect input and output | |
1713 | in the @code{run} command line, or you can use the @code{tty} command to | |
1714 | set a different device for your program. | |
1715 | @xref{Input/Output, ,Your program's input and output}. | |
1716 | ||
1717 | @cindex pipes | |
1718 | @emph{Warning:} While input and output redirection work, you cannot use | |
1719 | pipes to pass the output of the program you are debugging to another | |
1720 | program; if you attempt this, @value{GDBN} is likely to wind up debugging the | |
1721 | wrong program. | |
1722 | @end table | |
c906108c SS |
1723 | |
1724 | When you issue the @code{run} command, your program begins to execute | |
1725 | immediately. @xref{Stopping, ,Stopping and continuing}, for discussion | |
1726 | of how to arrange for your program to stop. Once your program has | |
1727 | stopped, you may call functions in your program, using the @code{print} | |
1728 | or @code{call} commands. @xref{Data, ,Examining Data}. | |
1729 | ||
1730 | If the modification time of your symbol file has changed since the last | |
1731 | time @value{GDBN} read its symbols, @value{GDBN} discards its symbol | |
1732 | table, and reads it again. When it does this, @value{GDBN} tries to retain | |
1733 | your current breakpoints. | |
1734 | ||
6d2ebf8b | 1735 | @node Arguments |
c906108c SS |
1736 | @section Your program's arguments |
1737 | ||
1738 | @cindex arguments (to your program) | |
1739 | The arguments to your program can be specified by the arguments of the | |
5d161b24 | 1740 | @code{run} command. |
c906108c SS |
1741 | They are passed to a shell, which expands wildcard characters and |
1742 | performs redirection of I/O, and thence to your program. Your | |
1743 | @code{SHELL} environment variable (if it exists) specifies what shell | |
1744 | @value{GDBN} uses. If you do not define @code{SHELL}, @value{GDBN} uses | |
d4f3574e SS |
1745 | the default shell (@file{/bin/sh} on Unix). |
1746 | ||
1747 | On non-Unix systems, the program is usually invoked directly by | |
1748 | @value{GDBN}, which emulates I/O redirection via the appropriate system | |
1749 | calls, and the wildcard characters are expanded by the startup code of | |
1750 | the program, not by the shell. | |
c906108c SS |
1751 | |
1752 | @code{run} with no arguments uses the same arguments used by the previous | |
1753 | @code{run}, or those set by the @code{set args} command. | |
1754 | ||
c906108c | 1755 | @table @code |
41afff9a | 1756 | @kindex set args |
c906108c SS |
1757 | @item set args |
1758 | Specify the arguments to be used the next time your program is run. If | |
1759 | @code{set args} has no arguments, @code{run} executes your program | |
1760 | with no arguments. Once you have run your program with arguments, | |
1761 | using @code{set args} before the next @code{run} is the only way to run | |
1762 | it again without arguments. | |
1763 | ||
1764 | @kindex show args | |
1765 | @item show args | |
1766 | Show the arguments to give your program when it is started. | |
1767 | @end table | |
1768 | ||
6d2ebf8b | 1769 | @node Environment |
c906108c SS |
1770 | @section Your program's environment |
1771 | ||
1772 | @cindex environment (of your program) | |
1773 | The @dfn{environment} consists of a set of environment variables and | |
1774 | their values. Environment variables conventionally record such things as | |
1775 | your user name, your home directory, your terminal type, and your search | |
1776 | path for programs to run. Usually you set up environment variables with | |
1777 | the shell and they are inherited by all the other programs you run. When | |
1778 | debugging, it can be useful to try running your program with a modified | |
1779 | environment without having to start @value{GDBN} over again. | |
1780 | ||
1781 | @table @code | |
1782 | @kindex path | |
1783 | @item path @var{directory} | |
1784 | Add @var{directory} to the front of the @code{PATH} environment variable | |
17cc6a06 EZ |
1785 | (the search path for executables) that will be passed to your program. |
1786 | The value of @code{PATH} used by @value{GDBN} does not change. | |
d4f3574e SS |
1787 | You may specify several directory names, separated by whitespace or by a |
1788 | system-dependent separator character (@samp{:} on Unix, @samp{;} on | |
1789 | MS-DOS and MS-Windows). If @var{directory} is already in the path, it | |
1790 | is moved to the front, so it is searched sooner. | |
c906108c SS |
1791 | |
1792 | You can use the string @samp{$cwd} to refer to whatever is the current | |
1793 | working directory at the time @value{GDBN} searches the path. If you | |
1794 | use @samp{.} instead, it refers to the directory where you executed the | |
1795 | @code{path} command. @value{GDBN} replaces @samp{.} in the | |
1796 | @var{directory} argument (with the current path) before adding | |
1797 | @var{directory} to the search path. | |
1798 | @c 'path' is explicitly nonrepeatable, but RMS points out it is silly to | |
1799 | @c document that, since repeating it would be a no-op. | |
1800 | ||
1801 | @kindex show paths | |
1802 | @item show paths | |
1803 | Display the list of search paths for executables (the @code{PATH} | |
1804 | environment variable). | |
1805 | ||
1806 | @kindex show environment | |
1807 | @item show environment @r{[}@var{varname}@r{]} | |
1808 | Print the value of environment variable @var{varname} to be given to | |
1809 | your program when it starts. If you do not supply @var{varname}, | |
1810 | print the names and values of all environment variables to be given to | |
1811 | your program. You can abbreviate @code{environment} as @code{env}. | |
1812 | ||
1813 | @kindex set environment | |
53a5351d | 1814 | @item set environment @var{varname} @r{[}=@var{value}@r{]} |
c906108c SS |
1815 | Set environment variable @var{varname} to @var{value}. The value |
1816 | changes for your program only, not for @value{GDBN} itself. @var{value} may | |
1817 | be any string; the values of environment variables are just strings, and | |
1818 | any interpretation is supplied by your program itself. The @var{value} | |
1819 | parameter is optional; if it is eliminated, the variable is set to a | |
1820 | null value. | |
1821 | @c "any string" here does not include leading, trailing | |
1822 | @c blanks. Gnu asks: does anyone care? | |
1823 | ||
1824 | For example, this command: | |
1825 | ||
474c8240 | 1826 | @smallexample |
c906108c | 1827 | set env USER = foo |
474c8240 | 1828 | @end smallexample |
c906108c SS |
1829 | |
1830 | @noindent | |
d4f3574e | 1831 | tells the debugged program, when subsequently run, that its user is named |
c906108c SS |
1832 | @samp{foo}. (The spaces around @samp{=} are used for clarity here; they |
1833 | are not actually required.) | |
1834 | ||
1835 | @kindex unset environment | |
1836 | @item unset environment @var{varname} | |
1837 | Remove variable @var{varname} from the environment to be passed to your | |
1838 | program. This is different from @samp{set env @var{varname} =}; | |
1839 | @code{unset environment} removes the variable from the environment, | |
1840 | rather than assigning it an empty value. | |
1841 | @end table | |
1842 | ||
d4f3574e SS |
1843 | @emph{Warning:} On Unix systems, @value{GDBN} runs your program using |
1844 | the shell indicated | |
c906108c SS |
1845 | by your @code{SHELL} environment variable if it exists (or |
1846 | @code{/bin/sh} if not). If your @code{SHELL} variable names a shell | |
1847 | that runs an initialization file---such as @file{.cshrc} for C-shell, or | |
1848 | @file{.bashrc} for BASH---any variables you set in that file affect | |
1849 | your program. You may wish to move setting of environment variables to | |
1850 | files that are only run when you sign on, such as @file{.login} or | |
1851 | @file{.profile}. | |
1852 | ||
6d2ebf8b | 1853 | @node Working Directory |
c906108c SS |
1854 | @section Your program's working directory |
1855 | ||
1856 | @cindex working directory (of your program) | |
1857 | Each time you start your program with @code{run}, it inherits its | |
1858 | working directory from the current working directory of @value{GDBN}. | |
1859 | The @value{GDBN} working directory is initially whatever it inherited | |
1860 | from its parent process (typically the shell), but you can specify a new | |
1861 | working directory in @value{GDBN} with the @code{cd} command. | |
1862 | ||
1863 | The @value{GDBN} working directory also serves as a default for the commands | |
1864 | that specify files for @value{GDBN} to operate on. @xref{Files, ,Commands to | |
1865 | specify files}. | |
1866 | ||
1867 | @table @code | |
1868 | @kindex cd | |
1869 | @item cd @var{directory} | |
1870 | Set the @value{GDBN} working directory to @var{directory}. | |
1871 | ||
1872 | @kindex pwd | |
1873 | @item pwd | |
1874 | Print the @value{GDBN} working directory. | |
1875 | @end table | |
1876 | ||
6d2ebf8b | 1877 | @node Input/Output |
c906108c SS |
1878 | @section Your program's input and output |
1879 | ||
1880 | @cindex redirection | |
1881 | @cindex i/o | |
1882 | @cindex terminal | |
1883 | By default, the program you run under @value{GDBN} does input and output to | |
5d161b24 | 1884 | the same terminal that @value{GDBN} uses. @value{GDBN} switches the terminal |
c906108c SS |
1885 | to its own terminal modes to interact with you, but it records the terminal |
1886 | modes your program was using and switches back to them when you continue | |
1887 | running your program. | |
1888 | ||
1889 | @table @code | |
1890 | @kindex info terminal | |
1891 | @item info terminal | |
1892 | Displays information recorded by @value{GDBN} about the terminal modes your | |
1893 | program is using. | |
1894 | @end table | |
1895 | ||
1896 | You can redirect your program's input and/or output using shell | |
1897 | redirection with the @code{run} command. For example, | |
1898 | ||
474c8240 | 1899 | @smallexample |
c906108c | 1900 | run > outfile |
474c8240 | 1901 | @end smallexample |
c906108c SS |
1902 | |
1903 | @noindent | |
1904 | starts your program, diverting its output to the file @file{outfile}. | |
1905 | ||
1906 | @kindex tty | |
1907 | @cindex controlling terminal | |
1908 | Another way to specify where your program should do input and output is | |
1909 | with the @code{tty} command. This command accepts a file name as | |
1910 | argument, and causes this file to be the default for future @code{run} | |
1911 | commands. It also resets the controlling terminal for the child | |
1912 | process, for future @code{run} commands. For example, | |
1913 | ||
474c8240 | 1914 | @smallexample |
c906108c | 1915 | tty /dev/ttyb |
474c8240 | 1916 | @end smallexample |
c906108c SS |
1917 | |
1918 | @noindent | |
1919 | directs that processes started with subsequent @code{run} commands | |
1920 | default to do input and output on the terminal @file{/dev/ttyb} and have | |
1921 | that as their controlling terminal. | |
1922 | ||
1923 | An explicit redirection in @code{run} overrides the @code{tty} command's | |
1924 | effect on the input/output device, but not its effect on the controlling | |
1925 | terminal. | |
1926 | ||
1927 | When you use the @code{tty} command or redirect input in the @code{run} | |
1928 | command, only the input @emph{for your program} is affected. The input | |
1929 | for @value{GDBN} still comes from your terminal. | |
1930 | ||
6d2ebf8b | 1931 | @node Attach |
c906108c SS |
1932 | @section Debugging an already-running process |
1933 | @kindex attach | |
1934 | @cindex attach | |
1935 | ||
1936 | @table @code | |
1937 | @item attach @var{process-id} | |
1938 | This command attaches to a running process---one that was started | |
1939 | outside @value{GDBN}. (@code{info files} shows your active | |
1940 | targets.) The command takes as argument a process ID. The usual way to | |
1941 | find out the process-id of a Unix process is with the @code{ps} utility, | |
1942 | or with the @samp{jobs -l} shell command. | |
1943 | ||
1944 | @code{attach} does not repeat if you press @key{RET} a second time after | |
1945 | executing the command. | |
1946 | @end table | |
1947 | ||
1948 | To use @code{attach}, your program must be running in an environment | |
1949 | which supports processes; for example, @code{attach} does not work for | |
1950 | programs on bare-board targets that lack an operating system. You must | |
1951 | also have permission to send the process a signal. | |
1952 | ||
1953 | When you use @code{attach}, the debugger finds the program running in | |
1954 | the process first by looking in the current working directory, then (if | |
1955 | the program is not found) by using the source file search path | |
1956 | (@pxref{Source Path, ,Specifying source directories}). You can also use | |
1957 | the @code{file} command to load the program. @xref{Files, ,Commands to | |
1958 | Specify Files}. | |
1959 | ||
1960 | The first thing @value{GDBN} does after arranging to debug the specified | |
1961 | process is to stop it. You can examine and modify an attached process | |
53a5351d JM |
1962 | with all the @value{GDBN} commands that are ordinarily available when |
1963 | you start processes with @code{run}. You can insert breakpoints; you | |
1964 | can step and continue; you can modify storage. If you would rather the | |
1965 | process continue running, you may use the @code{continue} command after | |
c906108c SS |
1966 | attaching @value{GDBN} to the process. |
1967 | ||
1968 | @table @code | |
1969 | @kindex detach | |
1970 | @item detach | |
1971 | When you have finished debugging the attached process, you can use the | |
1972 | @code{detach} command to release it from @value{GDBN} control. Detaching | |
1973 | the process continues its execution. After the @code{detach} command, | |
1974 | that process and @value{GDBN} become completely independent once more, and you | |
1975 | are ready to @code{attach} another process or start one with @code{run}. | |
1976 | @code{detach} does not repeat if you press @key{RET} again after | |
1977 | executing the command. | |
1978 | @end table | |
1979 | ||
1980 | If you exit @value{GDBN} or use the @code{run} command while you have an | |
1981 | attached process, you kill that process. By default, @value{GDBN} asks | |
1982 | for confirmation if you try to do either of these things; you can | |
1983 | control whether or not you need to confirm by using the @code{set | |
1984 | confirm} command (@pxref{Messages/Warnings, ,Optional warnings and | |
1985 | messages}). | |
1986 | ||
6d2ebf8b | 1987 | @node Kill Process |
c906108c | 1988 | @section Killing the child process |
c906108c SS |
1989 | |
1990 | @table @code | |
1991 | @kindex kill | |
1992 | @item kill | |
1993 | Kill the child process in which your program is running under @value{GDBN}. | |
1994 | @end table | |
1995 | ||
1996 | This command is useful if you wish to debug a core dump instead of a | |
1997 | running process. @value{GDBN} ignores any core dump file while your program | |
1998 | is running. | |
1999 | ||
2000 | On some operating systems, a program cannot be executed outside @value{GDBN} | |
2001 | while you have breakpoints set on it inside @value{GDBN}. You can use the | |
2002 | @code{kill} command in this situation to permit running your program | |
2003 | outside the debugger. | |
2004 | ||
2005 | The @code{kill} command is also useful if you wish to recompile and | |
2006 | relink your program, since on many systems it is impossible to modify an | |
2007 | executable file while it is running in a process. In this case, when you | |
2008 | next type @code{run}, @value{GDBN} notices that the file has changed, and | |
2009 | reads the symbol table again (while trying to preserve your current | |
2010 | breakpoint settings). | |
2011 | ||
6d2ebf8b | 2012 | @node Threads |
c906108c | 2013 | @section Debugging programs with multiple threads |
c906108c SS |
2014 | |
2015 | @cindex threads of execution | |
2016 | @cindex multiple threads | |
2017 | @cindex switching threads | |
2018 | In some operating systems, such as HP-UX and Solaris, a single program | |
2019 | may have more than one @dfn{thread} of execution. The precise semantics | |
2020 | of threads differ from one operating system to another, but in general | |
2021 | the threads of a single program are akin to multiple processes---except | |
2022 | that they share one address space (that is, they can all examine and | |
2023 | modify the same variables). On the other hand, each thread has its own | |
2024 | registers and execution stack, and perhaps private memory. | |
2025 | ||
2026 | @value{GDBN} provides these facilities for debugging multi-thread | |
2027 | programs: | |
2028 | ||
2029 | @itemize @bullet | |
2030 | @item automatic notification of new threads | |
2031 | @item @samp{thread @var{threadno}}, a command to switch among threads | |
2032 | @item @samp{info threads}, a command to inquire about existing threads | |
5d161b24 | 2033 | @item @samp{thread apply [@var{threadno}] [@var{all}] @var{args}}, |
c906108c SS |
2034 | a command to apply a command to a list of threads |
2035 | @item thread-specific breakpoints | |
2036 | @end itemize | |
2037 | ||
c906108c SS |
2038 | @quotation |
2039 | @emph{Warning:} These facilities are not yet available on every | |
2040 | @value{GDBN} configuration where the operating system supports threads. | |
2041 | If your @value{GDBN} does not support threads, these commands have no | |
2042 | effect. For example, a system without thread support shows no output | |
2043 | from @samp{info threads}, and always rejects the @code{thread} command, | |
2044 | like this: | |
2045 | ||
2046 | @smallexample | |
2047 | (@value{GDBP}) info threads | |
2048 | (@value{GDBP}) thread 1 | |
2049 | Thread ID 1 not known. Use the "info threads" command to | |
2050 | see the IDs of currently known threads. | |
2051 | @end smallexample | |
2052 | @c FIXME to implementors: how hard would it be to say "sorry, this GDB | |
2053 | @c doesn't support threads"? | |
2054 | @end quotation | |
c906108c SS |
2055 | |
2056 | @cindex focus of debugging | |
2057 | @cindex current thread | |
2058 | The @value{GDBN} thread debugging facility allows you to observe all | |
2059 | threads while your program runs---but whenever @value{GDBN} takes | |
2060 | control, one thread in particular is always the focus of debugging. | |
2061 | This thread is called the @dfn{current thread}. Debugging commands show | |
2062 | program information from the perspective of the current thread. | |
2063 | ||
41afff9a | 2064 | @cindex @code{New} @var{systag} message |
c906108c SS |
2065 | @cindex thread identifier (system) |
2066 | @c FIXME-implementors!! It would be more helpful if the [New...] message | |
2067 | @c included GDB's numeric thread handle, so you could just go to that | |
2068 | @c thread without first checking `info threads'. | |
2069 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2070 | the target system's identification for the thread with a message in the | |
2071 | form @samp{[New @var{systag}]}. @var{systag} is a thread identifier | |
2072 | whose form varies depending on the particular system. For example, on | |
2073 | LynxOS, you might see | |
2074 | ||
474c8240 | 2075 | @smallexample |
c906108c | 2076 | [New process 35 thread 27] |
474c8240 | 2077 | @end smallexample |
c906108c SS |
2078 | |
2079 | @noindent | |
2080 | when @value{GDBN} notices a new thread. In contrast, on an SGI system, | |
2081 | the @var{systag} is simply something like @samp{process 368}, with no | |
2082 | further qualifier. | |
2083 | ||
2084 | @c FIXME!! (1) Does the [New...] message appear even for the very first | |
2085 | @c thread of a program, or does it only appear for the | |
6ca652b0 | 2086 | @c second---i.e.@: when it becomes obvious we have a multithread |
c906108c SS |
2087 | @c program? |
2088 | @c (2) *Is* there necessarily a first thread always? Or do some | |
2089 | @c multithread systems permit starting a program with multiple | |
5d161b24 | 2090 | @c threads ab initio? |
c906108c SS |
2091 | |
2092 | @cindex thread number | |
2093 | @cindex thread identifier (GDB) | |
2094 | For debugging purposes, @value{GDBN} associates its own thread | |
2095 | number---always a single integer---with each thread in your program. | |
2096 | ||
2097 | @table @code | |
2098 | @kindex info threads | |
2099 | @item info threads | |
2100 | Display a summary of all threads currently in your | |
2101 | program. @value{GDBN} displays for each thread (in this order): | |
2102 | ||
2103 | @enumerate | |
2104 | @item the thread number assigned by @value{GDBN} | |
2105 | ||
2106 | @item the target system's thread identifier (@var{systag}) | |
2107 | ||
2108 | @item the current stack frame summary for that thread | |
2109 | @end enumerate | |
2110 | ||
2111 | @noindent | |
2112 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
2113 | indicates the current thread. | |
2114 | ||
5d161b24 | 2115 | For example, |
c906108c SS |
2116 | @end table |
2117 | @c end table here to get a little more width for example | |
2118 | ||
2119 | @smallexample | |
2120 | (@value{GDBP}) info threads | |
2121 | 3 process 35 thread 27 0x34e5 in sigpause () | |
2122 | 2 process 35 thread 23 0x34e5 in sigpause () | |
2123 | * 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) | |
2124 | at threadtest.c:68 | |
2125 | @end smallexample | |
53a5351d JM |
2126 | |
2127 | On HP-UX systems: | |
c906108c SS |
2128 | |
2129 | @cindex thread number | |
2130 | @cindex thread identifier (GDB) | |
2131 | For debugging purposes, @value{GDBN} associates its own thread | |
2132 | number---a small integer assigned in thread-creation order---with each | |
2133 | thread in your program. | |
2134 | ||
41afff9a EZ |
2135 | @cindex @code{New} @var{systag} message, on HP-UX |
2136 | @cindex thread identifier (system), on HP-UX | |
c906108c SS |
2137 | @c FIXME-implementors!! It would be more helpful if the [New...] message |
2138 | @c included GDB's numeric thread handle, so you could just go to that | |
2139 | @c thread without first checking `info threads'. | |
2140 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2141 | both @value{GDBN}'s thread number and the target system's identification for the thread with a message in the | |
2142 | form @samp{[New @var{systag}]}. @var{systag} is a thread identifier | |
2143 | whose form varies depending on the particular system. For example, on | |
2144 | HP-UX, you see | |
2145 | ||
474c8240 | 2146 | @smallexample |
c906108c | 2147 | [New thread 2 (system thread 26594)] |
474c8240 | 2148 | @end smallexample |
c906108c SS |
2149 | |
2150 | @noindent | |
5d161b24 | 2151 | when @value{GDBN} notices a new thread. |
c906108c SS |
2152 | |
2153 | @table @code | |
2154 | @kindex info threads | |
2155 | @item info threads | |
2156 | Display a summary of all threads currently in your | |
2157 | program. @value{GDBN} displays for each thread (in this order): | |
2158 | ||
2159 | @enumerate | |
2160 | @item the thread number assigned by @value{GDBN} | |
2161 | ||
2162 | @item the target system's thread identifier (@var{systag}) | |
2163 | ||
2164 | @item the current stack frame summary for that thread | |
2165 | @end enumerate | |
2166 | ||
2167 | @noindent | |
2168 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
2169 | indicates the current thread. | |
2170 | ||
5d161b24 | 2171 | For example, |
c906108c SS |
2172 | @end table |
2173 | @c end table here to get a little more width for example | |
2174 | ||
474c8240 | 2175 | @smallexample |
c906108c | 2176 | (@value{GDBP}) info threads |
6d2ebf8b SS |
2177 | * 3 system thread 26607 worker (wptr=0x7b09c318 "@@") \@* |
2178 | at quicksort.c:137 | |
2179 | 2 system thread 26606 0x7b0030d8 in __ksleep () \@* | |
2180 | from /usr/lib/libc.2 | |
2181 | 1 system thread 27905 0x7b003498 in _brk () \@* | |
2182 | from /usr/lib/libc.2 | |
474c8240 | 2183 | @end smallexample |
c906108c SS |
2184 | |
2185 | @table @code | |
2186 | @kindex thread @var{threadno} | |
2187 | @item thread @var{threadno} | |
2188 | Make thread number @var{threadno} the current thread. The command | |
2189 | argument @var{threadno} is the internal @value{GDBN} thread number, as | |
2190 | shown in the first field of the @samp{info threads} display. | |
2191 | @value{GDBN} responds by displaying the system identifier of the thread | |
2192 | you selected, and its current stack frame summary: | |
2193 | ||
2194 | @smallexample | |
2195 | @c FIXME!! This example made up; find a @value{GDBN} w/threads and get real one | |
2196 | (@value{GDBP}) thread 2 | |
c906108c | 2197 | [Switching to process 35 thread 23] |
c906108c SS |
2198 | 0x34e5 in sigpause () |
2199 | @end smallexample | |
2200 | ||
2201 | @noindent | |
2202 | As with the @samp{[New @dots{}]} message, the form of the text after | |
2203 | @samp{Switching to} depends on your system's conventions for identifying | |
5d161b24 | 2204 | threads. |
c906108c SS |
2205 | |
2206 | @kindex thread apply | |
2207 | @item thread apply [@var{threadno}] [@var{all}] @var{args} | |
2208 | The @code{thread apply} command allows you to apply a command to one or | |
2209 | more threads. Specify the numbers of the threads that you want affected | |
2210 | with the command argument @var{threadno}. @var{threadno} is the internal | |
2211 | @value{GDBN} thread number, as shown in the first field of the @samp{info | |
5d161b24 DB |
2212 | threads} display. To apply a command to all threads, use |
2213 | @code{thread apply all} @var{args}. | |
c906108c SS |
2214 | @end table |
2215 | ||
2216 | @cindex automatic thread selection | |
2217 | @cindex switching threads automatically | |
2218 | @cindex threads, automatic switching | |
2219 | Whenever @value{GDBN} stops your program, due to a breakpoint or a | |
2220 | signal, it automatically selects the thread where that breakpoint or | |
2221 | signal happened. @value{GDBN} alerts you to the context switch with a | |
2222 | message of the form @samp{[Switching to @var{systag}]} to identify the | |
2223 | thread. | |
2224 | ||
2225 | @xref{Thread Stops,,Stopping and starting multi-thread programs}, for | |
2226 | more information about how @value{GDBN} behaves when you stop and start | |
2227 | programs with multiple threads. | |
2228 | ||
2229 | @xref{Set Watchpoints,,Setting watchpoints}, for information about | |
2230 | watchpoints in programs with multiple threads. | |
c906108c | 2231 | |
6d2ebf8b | 2232 | @node Processes |
c906108c SS |
2233 | @section Debugging programs with multiple processes |
2234 | ||
2235 | @cindex fork, debugging programs which call | |
2236 | @cindex multiple processes | |
2237 | @cindex processes, multiple | |
53a5351d JM |
2238 | On most systems, @value{GDBN} has no special support for debugging |
2239 | programs which create additional processes using the @code{fork} | |
2240 | function. When a program forks, @value{GDBN} will continue to debug the | |
2241 | parent process and the child process will run unimpeded. If you have | |
2242 | set a breakpoint in any code which the child then executes, the child | |
2243 | will get a @code{SIGTRAP} signal which (unless it catches the signal) | |
2244 | will cause it to terminate. | |
c906108c SS |
2245 | |
2246 | However, if you want to debug the child process there is a workaround | |
2247 | which isn't too painful. Put a call to @code{sleep} in the code which | |
2248 | the child process executes after the fork. It may be useful to sleep | |
2249 | only if a certain environment variable is set, or a certain file exists, | |
2250 | so that the delay need not occur when you don't want to run @value{GDBN} | |
2251 | on the child. While the child is sleeping, use the @code{ps} program to | |
2252 | get its process ID. Then tell @value{GDBN} (a new invocation of | |
2253 | @value{GDBN} if you are also debugging the parent process) to attach to | |
d4f3574e | 2254 | the child process (@pxref{Attach}). From that point on you can debug |
c906108c | 2255 | the child process just like any other process which you attached to. |
c906108c | 2256 | |
53a5351d JM |
2257 | On HP-UX (11.x and later only?), @value{GDBN} provides support for |
2258 | debugging programs that create additional processes using the | |
2259 | @code{fork} or @code{vfork} function. | |
c906108c SS |
2260 | |
2261 | By default, when a program forks, @value{GDBN} will continue to debug | |
2262 | the parent process and the child process will run unimpeded. | |
2263 | ||
2264 | If you want to follow the child process instead of the parent process, | |
2265 | use the command @w{@code{set follow-fork-mode}}. | |
2266 | ||
2267 | @table @code | |
2268 | @kindex set follow-fork-mode | |
2269 | @item set follow-fork-mode @var{mode} | |
2270 | Set the debugger response to a program call of @code{fork} or | |
2271 | @code{vfork}. A call to @code{fork} or @code{vfork} creates a new | |
2272 | process. The @var{mode} can be: | |
2273 | ||
2274 | @table @code | |
2275 | @item parent | |
2276 | The original process is debugged after a fork. The child process runs | |
2df3850c | 2277 | unimpeded. This is the default. |
c906108c SS |
2278 | |
2279 | @item child | |
2280 | The new process is debugged after a fork. The parent process runs | |
2281 | unimpeded. | |
2282 | ||
2283 | @item ask | |
2284 | The debugger will ask for one of the above choices. | |
2285 | @end table | |
2286 | ||
2287 | @item show follow-fork-mode | |
2df3850c | 2288 | Display the current debugger response to a @code{fork} or @code{vfork} call. |
c906108c SS |
2289 | @end table |
2290 | ||
2291 | If you ask to debug a child process and a @code{vfork} is followed by an | |
2292 | @code{exec}, @value{GDBN} executes the new target up to the first | |
2293 | breakpoint in the new target. If you have a breakpoint set on | |
2294 | @code{main} in your original program, the breakpoint will also be set on | |
2295 | the child process's @code{main}. | |
2296 | ||
2297 | When a child process is spawned by @code{vfork}, you cannot debug the | |
2298 | child or parent until an @code{exec} call completes. | |
2299 | ||
2300 | If you issue a @code{run} command to @value{GDBN} after an @code{exec} | |
2301 | call executes, the new target restarts. To restart the parent process, | |
2302 | use the @code{file} command with the parent executable name as its | |
2303 | argument. | |
2304 | ||
2305 | You can use the @code{catch} command to make @value{GDBN} stop whenever | |
2306 | a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set | |
2307 | Catchpoints, ,Setting catchpoints}. | |
c906108c | 2308 | |
6d2ebf8b | 2309 | @node Stopping |
c906108c SS |
2310 | @chapter Stopping and Continuing |
2311 | ||
2312 | The principal purposes of using a debugger are so that you can stop your | |
2313 | program before it terminates; or so that, if your program runs into | |
2314 | trouble, you can investigate and find out why. | |
2315 | ||
7a292a7a SS |
2316 | Inside @value{GDBN}, your program may stop for any of several reasons, |
2317 | such as a signal, a breakpoint, or reaching a new line after a | |
2318 | @value{GDBN} command such as @code{step}. You may then examine and | |
2319 | change variables, set new breakpoints or remove old ones, and then | |
2320 | continue execution. Usually, the messages shown by @value{GDBN} provide | |
2321 | ample explanation of the status of your program---but you can also | |
2322 | explicitly request this information at any time. | |
c906108c SS |
2323 | |
2324 | @table @code | |
2325 | @kindex info program | |
2326 | @item info program | |
2327 | Display information about the status of your program: whether it is | |
7a292a7a | 2328 | running or not, what process it is, and why it stopped. |
c906108c SS |
2329 | @end table |
2330 | ||
2331 | @menu | |
2332 | * Breakpoints:: Breakpoints, watchpoints, and catchpoints | |
2333 | * Continuing and Stepping:: Resuming execution | |
c906108c | 2334 | * Signals:: Signals |
c906108c | 2335 | * Thread Stops:: Stopping and starting multi-thread programs |
c906108c SS |
2336 | @end menu |
2337 | ||
6d2ebf8b | 2338 | @node Breakpoints |
c906108c SS |
2339 | @section Breakpoints, watchpoints, and catchpoints |
2340 | ||
2341 | @cindex breakpoints | |
2342 | A @dfn{breakpoint} makes your program stop whenever a certain point in | |
2343 | the program is reached. For each breakpoint, you can add conditions to | |
2344 | control in finer detail whether your program stops. You can set | |
2345 | breakpoints with the @code{break} command and its variants (@pxref{Set | |
2346 | Breaks, ,Setting breakpoints}), to specify the place where your program | |
2347 | should stop by line number, function name or exact address in the | |
2348 | program. | |
2349 | ||
2350 | In HP-UX, SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can set | |
2351 | breakpoints in shared libraries before the executable is run. There is | |
2352 | a minor limitation on HP-UX systems: you must wait until the executable | |
2353 | is run in order to set breakpoints in shared library routines that are | |
2354 | not called directly by the program (for example, routines that are | |
2355 | arguments in a @code{pthread_create} call). | |
2356 | ||
2357 | @cindex watchpoints | |
2358 | @cindex memory tracing | |
2359 | @cindex breakpoint on memory address | |
2360 | @cindex breakpoint on variable modification | |
2361 | A @dfn{watchpoint} is a special breakpoint that stops your program | |
2362 | when the value of an expression changes. You must use a different | |
2363 | command to set watchpoints (@pxref{Set Watchpoints, ,Setting | |
2364 | watchpoints}), but aside from that, you can manage a watchpoint like | |
2365 | any other breakpoint: you enable, disable, and delete both breakpoints | |
2366 | and watchpoints using the same commands. | |
2367 | ||
2368 | You can arrange to have values from your program displayed automatically | |
2369 | whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,, | |
2370 | Automatic display}. | |
2371 | ||
2372 | @cindex catchpoints | |
2373 | @cindex breakpoint on events | |
2374 | A @dfn{catchpoint} is another special breakpoint that stops your program | |
b37052ae | 2375 | when a certain kind of event occurs, such as the throwing of a C@t{++} |
c906108c SS |
2376 | exception or the loading of a library. As with watchpoints, you use a |
2377 | different command to set a catchpoint (@pxref{Set Catchpoints, ,Setting | |
2378 | catchpoints}), but aside from that, you can manage a catchpoint like any | |
2379 | other breakpoint. (To stop when your program receives a signal, use the | |
d4f3574e | 2380 | @code{handle} command; see @ref{Signals, ,Signals}.) |
c906108c SS |
2381 | |
2382 | @cindex breakpoint numbers | |
2383 | @cindex numbers for breakpoints | |
2384 | @value{GDBN} assigns a number to each breakpoint, watchpoint, or | |
2385 | catchpoint when you create it; these numbers are successive integers | |
2386 | starting with one. In many of the commands for controlling various | |
2387 | features of breakpoints you use the breakpoint number to say which | |
2388 | breakpoint you want to change. Each breakpoint may be @dfn{enabled} or | |
2389 | @dfn{disabled}; if disabled, it has no effect on your program until you | |
2390 | enable it again. | |
2391 | ||
c5394b80 JM |
2392 | @cindex breakpoint ranges |
2393 | @cindex ranges of breakpoints | |
2394 | Some @value{GDBN} commands accept a range of breakpoints on which to | |
2395 | operate. A breakpoint range is either a single breakpoint number, like | |
2396 | @samp{5}, or two such numbers, in increasing order, separated by a | |
2397 | hyphen, like @samp{5-7}. When a breakpoint range is given to a command, | |
2398 | all breakpoint in that range are operated on. | |
2399 | ||
c906108c SS |
2400 | @menu |
2401 | * Set Breaks:: Setting breakpoints | |
2402 | * Set Watchpoints:: Setting watchpoints | |
2403 | * Set Catchpoints:: Setting catchpoints | |
2404 | * Delete Breaks:: Deleting breakpoints | |
2405 | * Disabling:: Disabling breakpoints | |
2406 | * Conditions:: Break conditions | |
2407 | * Break Commands:: Breakpoint command lists | |
c906108c | 2408 | * Breakpoint Menus:: Breakpoint menus |
d4f3574e | 2409 | * Error in Breakpoints:: ``Cannot insert breakpoints'' |
c906108c SS |
2410 | @end menu |
2411 | ||
6d2ebf8b | 2412 | @node Set Breaks |
c906108c SS |
2413 | @subsection Setting breakpoints |
2414 | ||
5d161b24 | 2415 | @c FIXME LMB what does GDB do if no code on line of breakpt? |
c906108c SS |
2416 | @c consider in particular declaration with/without initialization. |
2417 | @c | |
2418 | @c FIXME 2 is there stuff on this already? break at fun start, already init? | |
2419 | ||
2420 | @kindex break | |
41afff9a EZ |
2421 | @kindex b @r{(@code{break})} |
2422 | @vindex $bpnum@r{, convenience variable} | |
c906108c SS |
2423 | @cindex latest breakpoint |
2424 | Breakpoints are set with the @code{break} command (abbreviated | |
5d161b24 | 2425 | @code{b}). The debugger convenience variable @samp{$bpnum} records the |
f3b28801 | 2426 | number of the breakpoint you've set most recently; see @ref{Convenience |
c906108c SS |
2427 | Vars,, Convenience variables}, for a discussion of what you can do with |
2428 | convenience variables. | |
2429 | ||
2430 | You have several ways to say where the breakpoint should go. | |
2431 | ||
2432 | @table @code | |
2433 | @item break @var{function} | |
5d161b24 | 2434 | Set a breakpoint at entry to function @var{function}. |
c906108c | 2435 | When using source languages that permit overloading of symbols, such as |
b37052ae | 2436 | C@t{++}, @var{function} may refer to more than one possible place to break. |
c906108c | 2437 | @xref{Breakpoint Menus,,Breakpoint menus}, for a discussion of that situation. |
c906108c SS |
2438 | |
2439 | @item break +@var{offset} | |
2440 | @itemx break -@var{offset} | |
2441 | Set a breakpoint some number of lines forward or back from the position | |
d4f3574e | 2442 | at which execution stopped in the currently selected @dfn{stack frame}. |
2df3850c | 2443 | (@xref{Frames, ,Frames}, for a description of stack frames.) |
c906108c SS |
2444 | |
2445 | @item break @var{linenum} | |
2446 | Set a breakpoint at line @var{linenum} in the current source file. | |
d4f3574e SS |
2447 | The current source file is the last file whose source text was printed. |
2448 | The breakpoint will stop your program just before it executes any of the | |
c906108c SS |
2449 | code on that line. |
2450 | ||
2451 | @item break @var{filename}:@var{linenum} | |
2452 | Set a breakpoint at line @var{linenum} in source file @var{filename}. | |
2453 | ||
2454 | @item break @var{filename}:@var{function} | |
2455 | Set a breakpoint at entry to function @var{function} found in file | |
2456 | @var{filename}. Specifying a file name as well as a function name is | |
2457 | superfluous except when multiple files contain similarly named | |
2458 | functions. | |
2459 | ||
2460 | @item break *@var{address} | |
2461 | Set a breakpoint at address @var{address}. You can use this to set | |
2462 | breakpoints in parts of your program which do not have debugging | |
2463 | information or source files. | |
2464 | ||
2465 | @item break | |
2466 | When called without any arguments, @code{break} sets a breakpoint at | |
2467 | the next instruction to be executed in the selected stack frame | |
2468 | (@pxref{Stack, ,Examining the Stack}). In any selected frame but the | |
2469 | innermost, this makes your program stop as soon as control | |
2470 | returns to that frame. This is similar to the effect of a | |
2471 | @code{finish} command in the frame inside the selected frame---except | |
2472 | that @code{finish} does not leave an active breakpoint. If you use | |
2473 | @code{break} without an argument in the innermost frame, @value{GDBN} stops | |
2474 | the next time it reaches the current location; this may be useful | |
2475 | inside loops. | |
2476 | ||
2477 | @value{GDBN} normally ignores breakpoints when it resumes execution, until at | |
2478 | least one instruction has been executed. If it did not do this, you | |
2479 | would be unable to proceed past a breakpoint without first disabling the | |
2480 | breakpoint. This rule applies whether or not the breakpoint already | |
2481 | existed when your program stopped. | |
2482 | ||
2483 | @item break @dots{} if @var{cond} | |
2484 | Set a breakpoint with condition @var{cond}; evaluate the expression | |
2485 | @var{cond} each time the breakpoint is reached, and stop only if the | |
2486 | value is nonzero---that is, if @var{cond} evaluates as true. | |
2487 | @samp{@dots{}} stands for one of the possible arguments described | |
2488 | above (or no argument) specifying where to break. @xref{Conditions, | |
2489 | ,Break conditions}, for more information on breakpoint conditions. | |
2490 | ||
2491 | @kindex tbreak | |
2492 | @item tbreak @var{args} | |
2493 | Set a breakpoint enabled only for one stop. @var{args} are the | |
2494 | same as for the @code{break} command, and the breakpoint is set in the same | |
2495 | way, but the breakpoint is automatically deleted after the first time your | |
2496 | program stops there. @xref{Disabling, ,Disabling breakpoints}. | |
2497 | ||
c906108c SS |
2498 | @kindex hbreak |
2499 | @item hbreak @var{args} | |
d4f3574e SS |
2500 | Set a hardware-assisted breakpoint. @var{args} are the same as for the |
2501 | @code{break} command and the breakpoint is set in the same way, but the | |
c906108c SS |
2502 | breakpoint requires hardware support and some target hardware may not |
2503 | have this support. The main purpose of this is EPROM/ROM code | |
d4f3574e SS |
2504 | debugging, so you can set a breakpoint at an instruction without |
2505 | changing the instruction. This can be used with the new trap-generation | |
2506 | provided by SPARClite DSU and some x86-based targets. These targets | |
2507 | will generate traps when a program accesses some data or instruction | |
2508 | address that is assigned to the debug registers. However the hardware | |
2509 | breakpoint registers can take a limited number of breakpoints. For | |
2510 | example, on the DSU, only two data breakpoints can be set at a time, and | |
2511 | @value{GDBN} will reject this command if more than two are used. Delete | |
2512 | or disable unused hardware breakpoints before setting new ones | |
2513 | (@pxref{Disabling, ,Disabling}). @xref{Conditions, ,Break conditions}. | |
501eef12 AC |
2514 | @xref{set remote hardware-breakpoint-limit}. |
2515 | ||
c906108c SS |
2516 | |
2517 | @kindex thbreak | |
2518 | @item thbreak @var{args} | |
2519 | Set a hardware-assisted breakpoint enabled only for one stop. @var{args} | |
2520 | are the same as for the @code{hbreak} command and the breakpoint is set in | |
5d161b24 | 2521 | the same way. However, like the @code{tbreak} command, |
c906108c SS |
2522 | the breakpoint is automatically deleted after the |
2523 | first time your program stops there. Also, like the @code{hbreak} | |
5d161b24 DB |
2524 | command, the breakpoint requires hardware support and some target hardware |
2525 | may not have this support. @xref{Disabling, ,Disabling breakpoints}. | |
d4f3574e | 2526 | See also @ref{Conditions, ,Break conditions}. |
c906108c SS |
2527 | |
2528 | @kindex rbreak | |
2529 | @cindex regular expression | |
2530 | @item rbreak @var{regex} | |
c906108c | 2531 | Set breakpoints on all functions matching the regular expression |
11cf8741 JM |
2532 | @var{regex}. This command sets an unconditional breakpoint on all |
2533 | matches, printing a list of all breakpoints it set. Once these | |
2534 | breakpoints are set, they are treated just like the breakpoints set with | |
2535 | the @code{break} command. You can delete them, disable them, or make | |
2536 | them conditional the same way as any other breakpoint. | |
2537 | ||
2538 | The syntax of the regular expression is the standard one used with tools | |
2539 | like @file{grep}. Note that this is different from the syntax used by | |
2540 | shells, so for instance @code{foo*} matches all functions that include | |
2541 | an @code{fo} followed by zero or more @code{o}s. There is an implicit | |
2542 | @code{.*} leading and trailing the regular expression you supply, so to | |
2543 | match only functions that begin with @code{foo}, use @code{^foo}. | |
c906108c | 2544 | |
b37052ae | 2545 | When debugging C@t{++} programs, @code{rbreak} is useful for setting |
c906108c SS |
2546 | breakpoints on overloaded functions that are not members of any special |
2547 | classes. | |
c906108c SS |
2548 | |
2549 | @kindex info breakpoints | |
2550 | @cindex @code{$_} and @code{info breakpoints} | |
2551 | @item info breakpoints @r{[}@var{n}@r{]} | |
2552 | @itemx info break @r{[}@var{n}@r{]} | |
2553 | @itemx info watchpoints @r{[}@var{n}@r{]} | |
2554 | Print a table of all breakpoints, watchpoints, and catchpoints set and | |
2555 | not deleted, with the following columns for each breakpoint: | |
2556 | ||
2557 | @table @emph | |
2558 | @item Breakpoint Numbers | |
2559 | @item Type | |
2560 | Breakpoint, watchpoint, or catchpoint. | |
2561 | @item Disposition | |
2562 | Whether the breakpoint is marked to be disabled or deleted when hit. | |
2563 | @item Enabled or Disabled | |
2564 | Enabled breakpoints are marked with @samp{y}. @samp{n} marks breakpoints | |
2565 | that are not enabled. | |
2566 | @item Address | |
2df3850c | 2567 | Where the breakpoint is in your program, as a memory address. |
c906108c SS |
2568 | @item What |
2569 | Where the breakpoint is in the source for your program, as a file and | |
2570 | line number. | |
2571 | @end table | |
2572 | ||
2573 | @noindent | |
2574 | If a breakpoint is conditional, @code{info break} shows the condition on | |
2575 | the line following the affected breakpoint; breakpoint commands, if any, | |
2576 | are listed after that. | |
2577 | ||
2578 | @noindent | |
2579 | @code{info break} with a breakpoint | |
2580 | number @var{n} as argument lists only that breakpoint. The | |
2581 | convenience variable @code{$_} and the default examining-address for | |
2582 | the @code{x} command are set to the address of the last breakpoint | |
5d161b24 | 2583 | listed (@pxref{Memory, ,Examining memory}). |
c906108c SS |
2584 | |
2585 | @noindent | |
2586 | @code{info break} displays a count of the number of times the breakpoint | |
2587 | has been hit. This is especially useful in conjunction with the | |
2588 | @code{ignore} command. You can ignore a large number of breakpoint | |
2589 | hits, look at the breakpoint info to see how many times the breakpoint | |
2590 | was hit, and then run again, ignoring one less than that number. This | |
2591 | will get you quickly to the last hit of that breakpoint. | |
2592 | @end table | |
2593 | ||
2594 | @value{GDBN} allows you to set any number of breakpoints at the same place in | |
2595 | your program. There is nothing silly or meaningless about this. When | |
2596 | the breakpoints are conditional, this is even useful | |
2597 | (@pxref{Conditions, ,Break conditions}). | |
2598 | ||
2599 | @cindex negative breakpoint numbers | |
2600 | @cindex internal @value{GDBN} breakpoints | |
eb12ee30 AC |
2601 | @value{GDBN} itself sometimes sets breakpoints in your program for |
2602 | special purposes, such as proper handling of @code{longjmp} (in C | |
2603 | programs). These internal breakpoints are assigned negative numbers, | |
2604 | starting with @code{-1}; @samp{info breakpoints} does not display them. | |
c906108c | 2605 | You can see these breakpoints with the @value{GDBN} maintenance command |
eb12ee30 | 2606 | @samp{maint info breakpoints} (@pxref{maint info breakpoints}). |
c906108c SS |
2607 | |
2608 | ||
6d2ebf8b | 2609 | @node Set Watchpoints |
c906108c SS |
2610 | @subsection Setting watchpoints |
2611 | ||
2612 | @cindex setting watchpoints | |
2613 | @cindex software watchpoints | |
2614 | @cindex hardware watchpoints | |
2615 | You can use a watchpoint to stop execution whenever the value of an | |
2616 | expression changes, without having to predict a particular place where | |
2617 | this may happen. | |
2618 | ||
2619 | Depending on your system, watchpoints may be implemented in software or | |
2df3850c | 2620 | hardware. @value{GDBN} does software watchpointing by single-stepping your |
c906108c SS |
2621 | program and testing the variable's value each time, which is hundreds of |
2622 | times slower than normal execution. (But this may still be worth it, to | |
2623 | catch errors where you have no clue what part of your program is the | |
2624 | culprit.) | |
2625 | ||
1104b9e7 | 2626 | On some systems, such as HP-UX, @sc{gnu}/Linux and some other x86-based targets, |
2df3850c | 2627 | @value{GDBN} includes support for |
c906108c SS |
2628 | hardware watchpoints, which do not slow down the running of your |
2629 | program. | |
2630 | ||
2631 | @table @code | |
2632 | @kindex watch | |
2633 | @item watch @var{expr} | |
2634 | Set a watchpoint for an expression. @value{GDBN} will break when @var{expr} | |
2635 | is written into by the program and its value changes. | |
2636 | ||
2637 | @kindex rwatch | |
2638 | @item rwatch @var{expr} | |
2639 | Set a watchpoint that will break when watch @var{expr} is read by the program. | |
c906108c SS |
2640 | |
2641 | @kindex awatch | |
2642 | @item awatch @var{expr} | |
2df3850c | 2643 | Set a watchpoint that will break when @var{expr} is either read or written into |
7be570e7 | 2644 | by the program. |
c906108c SS |
2645 | |
2646 | @kindex info watchpoints | |
2647 | @item info watchpoints | |
2648 | This command prints a list of watchpoints, breakpoints, and catchpoints; | |
2649 | it is the same as @code{info break}. | |
2650 | @end table | |
2651 | ||
2652 | @value{GDBN} sets a @dfn{hardware watchpoint} if possible. Hardware | |
2653 | watchpoints execute very quickly, and the debugger reports a change in | |
2654 | value at the exact instruction where the change occurs. If @value{GDBN} | |
2655 | cannot set a hardware watchpoint, it sets a software watchpoint, which | |
2656 | executes more slowly and reports the change in value at the next | |
2657 | statement, not the instruction, after the change occurs. | |
2658 | ||
2659 | When you issue the @code{watch} command, @value{GDBN} reports | |
2660 | ||
474c8240 | 2661 | @smallexample |
c906108c | 2662 | Hardware watchpoint @var{num}: @var{expr} |
474c8240 | 2663 | @end smallexample |
c906108c SS |
2664 | |
2665 | @noindent | |
2666 | if it was able to set a hardware watchpoint. | |
2667 | ||
7be570e7 JM |
2668 | Currently, the @code{awatch} and @code{rwatch} commands can only set |
2669 | hardware watchpoints, because accesses to data that don't change the | |
2670 | value of the watched expression cannot be detected without examining | |
2671 | every instruction as it is being executed, and @value{GDBN} does not do | |
2672 | that currently. If @value{GDBN} finds that it is unable to set a | |
2673 | hardware breakpoint with the @code{awatch} or @code{rwatch} command, it | |
2674 | will print a message like this: | |
2675 | ||
2676 | @smallexample | |
2677 | Expression cannot be implemented with read/access watchpoint. | |
2678 | @end smallexample | |
2679 | ||
2680 | Sometimes, @value{GDBN} cannot set a hardware watchpoint because the | |
2681 | data type of the watched expression is wider than what a hardware | |
2682 | watchpoint on the target machine can handle. For example, some systems | |
2683 | can only watch regions that are up to 4 bytes wide; on such systems you | |
2684 | cannot set hardware watchpoints for an expression that yields a | |
2685 | double-precision floating-point number (which is typically 8 bytes | |
2686 | wide). As a work-around, it might be possible to break the large region | |
2687 | into a series of smaller ones and watch them with separate watchpoints. | |
2688 | ||
2689 | If you set too many hardware watchpoints, @value{GDBN} might be unable | |
2690 | to insert all of them when you resume the execution of your program. | |
2691 | Since the precise number of active watchpoints is unknown until such | |
2692 | time as the program is about to be resumed, @value{GDBN} might not be | |
2693 | able to warn you about this when you set the watchpoints, and the | |
2694 | warning will be printed only when the program is resumed: | |
2695 | ||
2696 | @smallexample | |
2697 | Hardware watchpoint @var{num}: Could not insert watchpoint | |
2698 | @end smallexample | |
2699 | ||
2700 | @noindent | |
2701 | If this happens, delete or disable some of the watchpoints. | |
2702 | ||
2703 | The SPARClite DSU will generate traps when a program accesses some data | |
2704 | or instruction address that is assigned to the debug registers. For the | |
2705 | data addresses, DSU facilitates the @code{watch} command. However the | |
2706 | hardware breakpoint registers can only take two data watchpoints, and | |
2707 | both watchpoints must be the same kind. For example, you can set two | |
2708 | watchpoints with @code{watch} commands, two with @code{rwatch} commands, | |
2709 | @strong{or} two with @code{awatch} commands, but you cannot set one | |
2710 | watchpoint with one command and the other with a different command. | |
c906108c SS |
2711 | @value{GDBN} will reject the command if you try to mix watchpoints. |
2712 | Delete or disable unused watchpoint commands before setting new ones. | |
2713 | ||
2714 | If you call a function interactively using @code{print} or @code{call}, | |
2df3850c | 2715 | any watchpoints you have set will be inactive until @value{GDBN} reaches another |
c906108c SS |
2716 | kind of breakpoint or the call completes. |
2717 | ||
7be570e7 JM |
2718 | @value{GDBN} automatically deletes watchpoints that watch local |
2719 | (automatic) variables, or expressions that involve such variables, when | |
2720 | they go out of scope, that is, when the execution leaves the block in | |
2721 | which these variables were defined. In particular, when the program | |
2722 | being debugged terminates, @emph{all} local variables go out of scope, | |
2723 | and so only watchpoints that watch global variables remain set. If you | |
2724 | rerun the program, you will need to set all such watchpoints again. One | |
2725 | way of doing that would be to set a code breakpoint at the entry to the | |
2726 | @code{main} function and when it breaks, set all the watchpoints. | |
2727 | ||
c906108c SS |
2728 | @quotation |
2729 | @cindex watchpoints and threads | |
2730 | @cindex threads and watchpoints | |
c906108c SS |
2731 | @emph{Warning:} In multi-thread programs, watchpoints have only limited |
2732 | usefulness. With the current watchpoint implementation, @value{GDBN} | |
2733 | can only watch the value of an expression @emph{in a single thread}. If | |
2734 | you are confident that the expression can only change due to the current | |
2735 | thread's activity (and if you are also confident that no other thread | |
2736 | can become current), then you can use watchpoints as usual. However, | |
2737 | @value{GDBN} may not notice when a non-current thread's activity changes | |
2738 | the expression. | |
53a5351d | 2739 | |
d4f3574e | 2740 | @c FIXME: this is almost identical to the previous paragraph. |
53a5351d JM |
2741 | @emph{HP-UX Warning:} In multi-thread programs, software watchpoints |
2742 | have only limited usefulness. If @value{GDBN} creates a software | |
2743 | watchpoint, it can only watch the value of an expression @emph{in a | |
2744 | single thread}. If you are confident that the expression can only | |
2745 | change due to the current thread's activity (and if you are also | |
2746 | confident that no other thread can become current), then you can use | |
2747 | software watchpoints as usual. However, @value{GDBN} may not notice | |
2748 | when a non-current thread's activity changes the expression. (Hardware | |
2749 | watchpoints, in contrast, watch an expression in all threads.) | |
c906108c | 2750 | @end quotation |
c906108c | 2751 | |
501eef12 AC |
2752 | @xref{set remote hardware-watchpoint-limit}. |
2753 | ||
6d2ebf8b | 2754 | @node Set Catchpoints |
c906108c | 2755 | @subsection Setting catchpoints |
d4f3574e | 2756 | @cindex catchpoints, setting |
c906108c SS |
2757 | @cindex exception handlers |
2758 | @cindex event handling | |
2759 | ||
2760 | You can use @dfn{catchpoints} to cause the debugger to stop for certain | |
b37052ae | 2761 | kinds of program events, such as C@t{++} exceptions or the loading of a |
c906108c SS |
2762 | shared library. Use the @code{catch} command to set a catchpoint. |
2763 | ||
2764 | @table @code | |
2765 | @kindex catch | |
2766 | @item catch @var{event} | |
2767 | Stop when @var{event} occurs. @var{event} can be any of the following: | |
2768 | @table @code | |
2769 | @item throw | |
2770 | @kindex catch throw | |
b37052ae | 2771 | The throwing of a C@t{++} exception. |
c906108c SS |
2772 | |
2773 | @item catch | |
2774 | @kindex catch catch | |
b37052ae | 2775 | The catching of a C@t{++} exception. |
c906108c SS |
2776 | |
2777 | @item exec | |
2778 | @kindex catch exec | |
2779 | A call to @code{exec}. This is currently only available for HP-UX. | |
2780 | ||
2781 | @item fork | |
2782 | @kindex catch fork | |
2783 | A call to @code{fork}. This is currently only available for HP-UX. | |
2784 | ||
2785 | @item vfork | |
2786 | @kindex catch vfork | |
2787 | A call to @code{vfork}. This is currently only available for HP-UX. | |
2788 | ||
2789 | @item load | |
2790 | @itemx load @var{libname} | |
2791 | @kindex catch load | |
2792 | The dynamic loading of any shared library, or the loading of the library | |
2793 | @var{libname}. This is currently only available for HP-UX. | |
2794 | ||
2795 | @item unload | |
2796 | @itemx unload @var{libname} | |
2797 | @kindex catch unload | |
2798 | The unloading of any dynamically loaded shared library, or the unloading | |
2799 | of the library @var{libname}. This is currently only available for HP-UX. | |
2800 | @end table | |
2801 | ||
2802 | @item tcatch @var{event} | |
2803 | Set a catchpoint that is enabled only for one stop. The catchpoint is | |
2804 | automatically deleted after the first time the event is caught. | |
2805 | ||
2806 | @end table | |
2807 | ||
2808 | Use the @code{info break} command to list the current catchpoints. | |
2809 | ||
b37052ae | 2810 | There are currently some limitations to C@t{++} exception handling |
c906108c SS |
2811 | (@code{catch throw} and @code{catch catch}) in @value{GDBN}: |
2812 | ||
2813 | @itemize @bullet | |
2814 | @item | |
2815 | If you call a function interactively, @value{GDBN} normally returns | |
2816 | control to you when the function has finished executing. If the call | |
2817 | raises an exception, however, the call may bypass the mechanism that | |
2818 | returns control to you and cause your program either to abort or to | |
2819 | simply continue running until it hits a breakpoint, catches a signal | |
2820 | that @value{GDBN} is listening for, or exits. This is the case even if | |
2821 | you set a catchpoint for the exception; catchpoints on exceptions are | |
2822 | disabled within interactive calls. | |
2823 | ||
2824 | @item | |
2825 | You cannot raise an exception interactively. | |
2826 | ||
2827 | @item | |
2828 | You cannot install an exception handler interactively. | |
2829 | @end itemize | |
2830 | ||
2831 | @cindex raise exceptions | |
2832 | Sometimes @code{catch} is not the best way to debug exception handling: | |
2833 | if you need to know exactly where an exception is raised, it is better to | |
2834 | stop @emph{before} the exception handler is called, since that way you | |
2835 | can see the stack before any unwinding takes place. If you set a | |
2836 | breakpoint in an exception handler instead, it may not be easy to find | |
2837 | out where the exception was raised. | |
2838 | ||
2839 | To stop just before an exception handler is called, you need some | |
b37052ae | 2840 | knowledge of the implementation. In the case of @sc{gnu} C@t{++}, exceptions are |
c906108c SS |
2841 | raised by calling a library function named @code{__raise_exception} |
2842 | which has the following ANSI C interface: | |
2843 | ||
474c8240 | 2844 | @smallexample |
c906108c | 2845 | /* @var{addr} is where the exception identifier is stored. |
d4f3574e SS |
2846 | @var{id} is the exception identifier. */ |
2847 | void __raise_exception (void **addr, void *id); | |
474c8240 | 2848 | @end smallexample |
c906108c SS |
2849 | |
2850 | @noindent | |
2851 | To make the debugger catch all exceptions before any stack | |
2852 | unwinding takes place, set a breakpoint on @code{__raise_exception} | |
2853 | (@pxref{Breakpoints, ,Breakpoints; watchpoints; and exceptions}). | |
2854 | ||
2855 | With a conditional breakpoint (@pxref{Conditions, ,Break conditions}) | |
2856 | that depends on the value of @var{id}, you can stop your program when | |
2857 | a specific exception is raised. You can use multiple conditional | |
2858 | breakpoints to stop your program when any of a number of exceptions are | |
2859 | raised. | |
2860 | ||
2861 | ||
6d2ebf8b | 2862 | @node Delete Breaks |
c906108c SS |
2863 | @subsection Deleting breakpoints |
2864 | ||
2865 | @cindex clearing breakpoints, watchpoints, catchpoints | |
2866 | @cindex deleting breakpoints, watchpoints, catchpoints | |
2867 | It is often necessary to eliminate a breakpoint, watchpoint, or | |
2868 | catchpoint once it has done its job and you no longer want your program | |
2869 | to stop there. This is called @dfn{deleting} the breakpoint. A | |
2870 | breakpoint that has been deleted no longer exists; it is forgotten. | |
2871 | ||
2872 | With the @code{clear} command you can delete breakpoints according to | |
2873 | where they are in your program. With the @code{delete} command you can | |
2874 | delete individual breakpoints, watchpoints, or catchpoints by specifying | |
2875 | their breakpoint numbers. | |
2876 | ||
2877 | It is not necessary to delete a breakpoint to proceed past it. @value{GDBN} | |
2878 | automatically ignores breakpoints on the first instruction to be executed | |
2879 | when you continue execution without changing the execution address. | |
2880 | ||
2881 | @table @code | |
2882 | @kindex clear | |
2883 | @item clear | |
2884 | Delete any breakpoints at the next instruction to be executed in the | |
2885 | selected stack frame (@pxref{Selection, ,Selecting a frame}). When | |
2886 | the innermost frame is selected, this is a good way to delete a | |
2887 | breakpoint where your program just stopped. | |
2888 | ||
2889 | @item clear @var{function} | |
2890 | @itemx clear @var{filename}:@var{function} | |
2891 | Delete any breakpoints set at entry to the function @var{function}. | |
2892 | ||
2893 | @item clear @var{linenum} | |
2894 | @itemx clear @var{filename}:@var{linenum} | |
2895 | Delete any breakpoints set at or within the code of the specified line. | |
2896 | ||
2897 | @cindex delete breakpoints | |
2898 | @kindex delete | |
41afff9a | 2899 | @kindex d @r{(@code{delete})} |
c5394b80 JM |
2900 | @item delete @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
2901 | Delete the breakpoints, watchpoints, or catchpoints of the breakpoint | |
2902 | ranges specified as arguments. If no argument is specified, delete all | |
c906108c SS |
2903 | breakpoints (@value{GDBN} asks confirmation, unless you have @code{set |
2904 | confirm off}). You can abbreviate this command as @code{d}. | |
2905 | @end table | |
2906 | ||
6d2ebf8b | 2907 | @node Disabling |
c906108c SS |
2908 | @subsection Disabling breakpoints |
2909 | ||
2910 | @kindex disable breakpoints | |
2911 | @kindex enable breakpoints | |
2912 | Rather than deleting a breakpoint, watchpoint, or catchpoint, you might | |
2913 | prefer to @dfn{disable} it. This makes the breakpoint inoperative as if | |
2914 | it had been deleted, but remembers the information on the breakpoint so | |
2915 | that you can @dfn{enable} it again later. | |
2916 | ||
2917 | You disable and enable breakpoints, watchpoints, and catchpoints with | |
2918 | the @code{enable} and @code{disable} commands, optionally specifying one | |
2919 | or more breakpoint numbers as arguments. Use @code{info break} or | |
2920 | @code{info watch} to print a list of breakpoints, watchpoints, and | |
2921 | catchpoints if you do not know which numbers to use. | |
2922 | ||
2923 | A breakpoint, watchpoint, or catchpoint can have any of four different | |
2924 | states of enablement: | |
2925 | ||
2926 | @itemize @bullet | |
2927 | @item | |
2928 | Enabled. The breakpoint stops your program. A breakpoint set | |
2929 | with the @code{break} command starts out in this state. | |
2930 | @item | |
2931 | Disabled. The breakpoint has no effect on your program. | |
2932 | @item | |
2933 | Enabled once. The breakpoint stops your program, but then becomes | |
d4f3574e | 2934 | disabled. |
c906108c SS |
2935 | @item |
2936 | Enabled for deletion. The breakpoint stops your program, but | |
d4f3574e SS |
2937 | immediately after it does so it is deleted permanently. A breakpoint |
2938 | set with the @code{tbreak} command starts out in this state. | |
c906108c SS |
2939 | @end itemize |
2940 | ||
2941 | You can use the following commands to enable or disable breakpoints, | |
2942 | watchpoints, and catchpoints: | |
2943 | ||
2944 | @table @code | |
2945 | @kindex disable breakpoints | |
2946 | @kindex disable | |
41afff9a | 2947 | @kindex dis @r{(@code{disable})} |
c5394b80 | 2948 | @item disable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
2949 | Disable the specified breakpoints---or all breakpoints, if none are |
2950 | listed. A disabled breakpoint has no effect but is not forgotten. All | |
2951 | options such as ignore-counts, conditions and commands are remembered in | |
2952 | case the breakpoint is enabled again later. You may abbreviate | |
2953 | @code{disable} as @code{dis}. | |
2954 | ||
2955 | @kindex enable breakpoints | |
2956 | @kindex enable | |
c5394b80 | 2957 | @item enable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
2958 | Enable the specified breakpoints (or all defined breakpoints). They |
2959 | become effective once again in stopping your program. | |
2960 | ||
c5394b80 | 2961 | @item enable @r{[}breakpoints@r{]} once @var{range}@dots{} |
c906108c SS |
2962 | Enable the specified breakpoints temporarily. @value{GDBN} disables any |
2963 | of these breakpoints immediately after stopping your program. | |
2964 | ||
c5394b80 | 2965 | @item enable @r{[}breakpoints@r{]} delete @var{range}@dots{} |
c906108c SS |
2966 | Enable the specified breakpoints to work once, then die. @value{GDBN} |
2967 | deletes any of these breakpoints as soon as your program stops there. | |
2968 | @end table | |
2969 | ||
d4f3574e SS |
2970 | @c FIXME: I think the following ``Except for [...] @code{tbreak}'' is |
2971 | @c confusing: tbreak is also initially enabled. | |
c906108c SS |
2972 | Except for a breakpoint set with @code{tbreak} (@pxref{Set Breaks, |
2973 | ,Setting breakpoints}), breakpoints that you set are initially enabled; | |
2974 | subsequently, they become disabled or enabled only when you use one of | |
2975 | the commands above. (The command @code{until} can set and delete a | |
2976 | breakpoint of its own, but it does not change the state of your other | |
2977 | breakpoints; see @ref{Continuing and Stepping, ,Continuing and | |
2978 | stepping}.) | |
2979 | ||
6d2ebf8b | 2980 | @node Conditions |
c906108c SS |
2981 | @subsection Break conditions |
2982 | @cindex conditional breakpoints | |
2983 | @cindex breakpoint conditions | |
2984 | ||
2985 | @c FIXME what is scope of break condition expr? Context where wanted? | |
5d161b24 | 2986 | @c in particular for a watchpoint? |
c906108c SS |
2987 | The simplest sort of breakpoint breaks every time your program reaches a |
2988 | specified place. You can also specify a @dfn{condition} for a | |
2989 | breakpoint. A condition is just a Boolean expression in your | |
2990 | programming language (@pxref{Expressions, ,Expressions}). A breakpoint with | |
2991 | a condition evaluates the expression each time your program reaches it, | |
2992 | and your program stops only if the condition is @emph{true}. | |
2993 | ||
2994 | This is the converse of using assertions for program validation; in that | |
2995 | situation, you want to stop when the assertion is violated---that is, | |
2996 | when the condition is false. In C, if you want to test an assertion expressed | |
2997 | by the condition @var{assert}, you should set the condition | |
2998 | @samp{! @var{assert}} on the appropriate breakpoint. | |
2999 | ||
3000 | Conditions are also accepted for watchpoints; you may not need them, | |
3001 | since a watchpoint is inspecting the value of an expression anyhow---but | |
3002 | it might be simpler, say, to just set a watchpoint on a variable name, | |
3003 | and specify a condition that tests whether the new value is an interesting | |
3004 | one. | |
3005 | ||
3006 | Break conditions can have side effects, and may even call functions in | |
3007 | your program. This can be useful, for example, to activate functions | |
3008 | that log program progress, or to use your own print functions to | |
3009 | format special data structures. The effects are completely predictable | |
3010 | unless there is another enabled breakpoint at the same address. (In | |
3011 | that case, @value{GDBN} might see the other breakpoint first and stop your | |
3012 | program without checking the condition of this one.) Note that | |
d4f3574e SS |
3013 | breakpoint commands are usually more convenient and flexible than break |
3014 | conditions for the | |
c906108c SS |
3015 | purpose of performing side effects when a breakpoint is reached |
3016 | (@pxref{Break Commands, ,Breakpoint command lists}). | |
3017 | ||
3018 | Break conditions can be specified when a breakpoint is set, by using | |
3019 | @samp{if} in the arguments to the @code{break} command. @xref{Set | |
3020 | Breaks, ,Setting breakpoints}. They can also be changed at any time | |
3021 | with the @code{condition} command. | |
53a5351d | 3022 | |
c906108c SS |
3023 | You can also use the @code{if} keyword with the @code{watch} command. |
3024 | The @code{catch} command does not recognize the @code{if} keyword; | |
3025 | @code{condition} is the only way to impose a further condition on a | |
3026 | catchpoint. | |
c906108c SS |
3027 | |
3028 | @table @code | |
3029 | @kindex condition | |
3030 | @item condition @var{bnum} @var{expression} | |
3031 | Specify @var{expression} as the break condition for breakpoint, | |
3032 | watchpoint, or catchpoint number @var{bnum}. After you set a condition, | |
3033 | breakpoint @var{bnum} stops your program only if the value of | |
3034 | @var{expression} is true (nonzero, in C). When you use | |
3035 | @code{condition}, @value{GDBN} checks @var{expression} immediately for | |
3036 | syntactic correctness, and to determine whether symbols in it have | |
d4f3574e SS |
3037 | referents in the context of your breakpoint. If @var{expression} uses |
3038 | symbols not referenced in the context of the breakpoint, @value{GDBN} | |
3039 | prints an error message: | |
3040 | ||
474c8240 | 3041 | @smallexample |
d4f3574e | 3042 | No symbol "foo" in current context. |
474c8240 | 3043 | @end smallexample |
d4f3574e SS |
3044 | |
3045 | @noindent | |
c906108c SS |
3046 | @value{GDBN} does |
3047 | not actually evaluate @var{expression} at the time the @code{condition} | |
d4f3574e SS |
3048 | command (or a command that sets a breakpoint with a condition, like |
3049 | @code{break if @dots{}}) is given, however. @xref{Expressions, ,Expressions}. | |
c906108c SS |
3050 | |
3051 | @item condition @var{bnum} | |
3052 | Remove the condition from breakpoint number @var{bnum}. It becomes | |
3053 | an ordinary unconditional breakpoint. | |
3054 | @end table | |
3055 | ||
3056 | @cindex ignore count (of breakpoint) | |
3057 | A special case of a breakpoint condition is to stop only when the | |
3058 | breakpoint has been reached a certain number of times. This is so | |
3059 | useful that there is a special way to do it, using the @dfn{ignore | |
3060 | count} of the breakpoint. Every breakpoint has an ignore count, which | |
3061 | is an integer. Most of the time, the ignore count is zero, and | |
3062 | therefore has no effect. But if your program reaches a breakpoint whose | |
3063 | ignore count is positive, then instead of stopping, it just decrements | |
3064 | the ignore count by one and continues. As a result, if the ignore count | |
3065 | value is @var{n}, the breakpoint does not stop the next @var{n} times | |
3066 | your program reaches it. | |
3067 | ||
3068 | @table @code | |
3069 | @kindex ignore | |
3070 | @item ignore @var{bnum} @var{count} | |
3071 | Set the ignore count of breakpoint number @var{bnum} to @var{count}. | |
3072 | The next @var{count} times the breakpoint is reached, your program's | |
3073 | execution does not stop; other than to decrement the ignore count, @value{GDBN} | |
3074 | takes no action. | |
3075 | ||
3076 | To make the breakpoint stop the next time it is reached, specify | |
3077 | a count of zero. | |
3078 | ||
3079 | When you use @code{continue} to resume execution of your program from a | |
3080 | breakpoint, you can specify an ignore count directly as an argument to | |
3081 | @code{continue}, rather than using @code{ignore}. @xref{Continuing and | |
3082 | Stepping,,Continuing and stepping}. | |
3083 | ||
3084 | If a breakpoint has a positive ignore count and a condition, the | |
3085 | condition is not checked. Once the ignore count reaches zero, | |
3086 | @value{GDBN} resumes checking the condition. | |
3087 | ||
3088 | You could achieve the effect of the ignore count with a condition such | |
3089 | as @w{@samp{$foo-- <= 0}} using a debugger convenience variable that | |
3090 | is decremented each time. @xref{Convenience Vars, ,Convenience | |
3091 | variables}. | |
3092 | @end table | |
3093 | ||
3094 | Ignore counts apply to breakpoints, watchpoints, and catchpoints. | |
3095 | ||
3096 | ||
6d2ebf8b | 3097 | @node Break Commands |
c906108c SS |
3098 | @subsection Breakpoint command lists |
3099 | ||
3100 | @cindex breakpoint commands | |
3101 | You can give any breakpoint (or watchpoint or catchpoint) a series of | |
3102 | commands to execute when your program stops due to that breakpoint. For | |
3103 | example, you might want to print the values of certain expressions, or | |
3104 | enable other breakpoints. | |
3105 | ||
3106 | @table @code | |
3107 | @kindex commands | |
3108 | @kindex end | |
3109 | @item commands @r{[}@var{bnum}@r{]} | |
3110 | @itemx @dots{} @var{command-list} @dots{} | |
3111 | @itemx end | |
3112 | Specify a list of commands for breakpoint number @var{bnum}. The commands | |
3113 | themselves appear on the following lines. Type a line containing just | |
3114 | @code{end} to terminate the commands. | |
3115 | ||
3116 | To remove all commands from a breakpoint, type @code{commands} and | |
3117 | follow it immediately with @code{end}; that is, give no commands. | |
3118 | ||
3119 | With no @var{bnum} argument, @code{commands} refers to the last | |
3120 | breakpoint, watchpoint, or catchpoint set (not to the breakpoint most | |
3121 | recently encountered). | |
3122 | @end table | |
3123 | ||
3124 | Pressing @key{RET} as a means of repeating the last @value{GDBN} command is | |
3125 | disabled within a @var{command-list}. | |
3126 | ||
3127 | You can use breakpoint commands to start your program up again. Simply | |
3128 | use the @code{continue} command, or @code{step}, or any other command | |
3129 | that resumes execution. | |
3130 | ||
3131 | Any other commands in the command list, after a command that resumes | |
3132 | execution, are ignored. This is because any time you resume execution | |
3133 | (even with a simple @code{next} or @code{step}), you may encounter | |
3134 | another breakpoint---which could have its own command list, leading to | |
3135 | ambiguities about which list to execute. | |
3136 | ||
3137 | @kindex silent | |
3138 | If the first command you specify in a command list is @code{silent}, the | |
3139 | usual message about stopping at a breakpoint is not printed. This may | |
3140 | be desirable for breakpoints that are to print a specific message and | |
3141 | then continue. If none of the remaining commands print anything, you | |
3142 | see no sign that the breakpoint was reached. @code{silent} is | |
3143 | meaningful only at the beginning of a breakpoint command list. | |
3144 | ||
3145 | The commands @code{echo}, @code{output}, and @code{printf} allow you to | |
3146 | print precisely controlled output, and are often useful in silent | |
3147 | breakpoints. @xref{Output, ,Commands for controlled output}. | |
3148 | ||
3149 | For example, here is how you could use breakpoint commands to print the | |
3150 | value of @code{x} at entry to @code{foo} whenever @code{x} is positive. | |
3151 | ||
474c8240 | 3152 | @smallexample |
c906108c SS |
3153 | break foo if x>0 |
3154 | commands | |
3155 | silent | |
3156 | printf "x is %d\n",x | |
3157 | cont | |
3158 | end | |
474c8240 | 3159 | @end smallexample |
c906108c SS |
3160 | |
3161 | One application for breakpoint commands is to compensate for one bug so | |
3162 | you can test for another. Put a breakpoint just after the erroneous line | |
3163 | of code, give it a condition to detect the case in which something | |
3164 | erroneous has been done, and give it commands to assign correct values | |
3165 | to any variables that need them. End with the @code{continue} command | |
3166 | so that your program does not stop, and start with the @code{silent} | |
3167 | command so that no output is produced. Here is an example: | |
3168 | ||
474c8240 | 3169 | @smallexample |
c906108c SS |
3170 | break 403 |
3171 | commands | |
3172 | silent | |
3173 | set x = y + 4 | |
3174 | cont | |
3175 | end | |
474c8240 | 3176 | @end smallexample |
c906108c | 3177 | |
6d2ebf8b | 3178 | @node Breakpoint Menus |
c906108c SS |
3179 | @subsection Breakpoint menus |
3180 | @cindex overloading | |
3181 | @cindex symbol overloading | |
3182 | ||
b37052ae | 3183 | Some programming languages (notably C@t{++}) permit a single function name |
c906108c SS |
3184 | to be defined several times, for application in different contexts. |
3185 | This is called @dfn{overloading}. When a function name is overloaded, | |
3186 | @samp{break @var{function}} is not enough to tell @value{GDBN} where you want | |
3187 | a breakpoint. If you realize this is a problem, you can use | |
3188 | something like @samp{break @var{function}(@var{types})} to specify which | |
3189 | particular version of the function you want. Otherwise, @value{GDBN} offers | |
3190 | you a menu of numbered choices for different possible breakpoints, and | |
3191 | waits for your selection with the prompt @samp{>}. The first two | |
3192 | options are always @samp{[0] cancel} and @samp{[1] all}. Typing @kbd{1} | |
3193 | sets a breakpoint at each definition of @var{function}, and typing | |
3194 | @kbd{0} aborts the @code{break} command without setting any new | |
3195 | breakpoints. | |
3196 | ||
3197 | For example, the following session excerpt shows an attempt to set a | |
3198 | breakpoint at the overloaded symbol @code{String::after}. | |
3199 | We choose three particular definitions of that function name: | |
3200 | ||
3201 | @c FIXME! This is likely to change to show arg type lists, at least | |
3202 | @smallexample | |
3203 | @group | |
3204 | (@value{GDBP}) b String::after | |
3205 | [0] cancel | |
3206 | [1] all | |
3207 | [2] file:String.cc; line number:867 | |
3208 | [3] file:String.cc; line number:860 | |
3209 | [4] file:String.cc; line number:875 | |
3210 | [5] file:String.cc; line number:853 | |
3211 | [6] file:String.cc; line number:846 | |
3212 | [7] file:String.cc; line number:735 | |
3213 | > 2 4 6 | |
3214 | Breakpoint 1 at 0xb26c: file String.cc, line 867. | |
3215 | Breakpoint 2 at 0xb344: file String.cc, line 875. | |
3216 | Breakpoint 3 at 0xafcc: file String.cc, line 846. | |
3217 | Multiple breakpoints were set. | |
3218 | Use the "delete" command to delete unwanted | |
3219 | breakpoints. | |
3220 | (@value{GDBP}) | |
3221 | @end group | |
3222 | @end smallexample | |
c906108c SS |
3223 | |
3224 | @c @ifclear BARETARGET | |
6d2ebf8b | 3225 | @node Error in Breakpoints |
d4f3574e | 3226 | @subsection ``Cannot insert breakpoints'' |
c906108c SS |
3227 | @c |
3228 | @c FIXME!! 14/6/95 Is there a real example of this? Let's use it. | |
3229 | @c | |
d4f3574e SS |
3230 | Under some operating systems, breakpoints cannot be used in a program if |
3231 | any other process is running that program. In this situation, | |
5d161b24 | 3232 | attempting to run or continue a program with a breakpoint causes |
d4f3574e SS |
3233 | @value{GDBN} to print an error message: |
3234 | ||
474c8240 | 3235 | @smallexample |
d4f3574e SS |
3236 | Cannot insert breakpoints. |
3237 | The same program may be running in another process. | |
474c8240 | 3238 | @end smallexample |
d4f3574e SS |
3239 | |
3240 | When this happens, you have three ways to proceed: | |
3241 | ||
3242 | @enumerate | |
3243 | @item | |
3244 | Remove or disable the breakpoints, then continue. | |
3245 | ||
3246 | @item | |
5d161b24 | 3247 | Suspend @value{GDBN}, and copy the file containing your program to a new |
d4f3574e | 3248 | name. Resume @value{GDBN} and use the @code{exec-file} command to specify |
5d161b24 | 3249 | that @value{GDBN} should run your program under that name. |
d4f3574e SS |
3250 | Then start your program again. |
3251 | ||
3252 | @item | |
3253 | Relink your program so that the text segment is nonsharable, using the | |
3254 | linker option @samp{-N}. The operating system limitation may not apply | |
3255 | to nonsharable executables. | |
3256 | @end enumerate | |
c906108c SS |
3257 | @c @end ifclear |
3258 | ||
d4f3574e SS |
3259 | A similar message can be printed if you request too many active |
3260 | hardware-assisted breakpoints and watchpoints: | |
3261 | ||
3262 | @c FIXME: the precise wording of this message may change; the relevant | |
3263 | @c source change is not committed yet (Sep 3, 1999). | |
3264 | @smallexample | |
3265 | Stopped; cannot insert breakpoints. | |
3266 | You may have requested too many hardware breakpoints and watchpoints. | |
3267 | @end smallexample | |
3268 | ||
3269 | @noindent | |
3270 | This message is printed when you attempt to resume the program, since | |
3271 | only then @value{GDBN} knows exactly how many hardware breakpoints and | |
3272 | watchpoints it needs to insert. | |
3273 | ||
3274 | When this message is printed, you need to disable or remove some of the | |
3275 | hardware-assisted breakpoints and watchpoints, and then continue. | |
3276 | ||
3277 | ||
6d2ebf8b | 3278 | @node Continuing and Stepping |
c906108c SS |
3279 | @section Continuing and stepping |
3280 | ||
3281 | @cindex stepping | |
3282 | @cindex continuing | |
3283 | @cindex resuming execution | |
3284 | @dfn{Continuing} means resuming program execution until your program | |
3285 | completes normally. In contrast, @dfn{stepping} means executing just | |
3286 | one more ``step'' of your program, where ``step'' may mean either one | |
3287 | line of source code, or one machine instruction (depending on what | |
7a292a7a SS |
3288 | particular command you use). Either when continuing or when stepping, |
3289 | your program may stop even sooner, due to a breakpoint or a signal. (If | |
d4f3574e SS |
3290 | it stops due to a signal, you may want to use @code{handle}, or use |
3291 | @samp{signal 0} to resume execution. @xref{Signals, ,Signals}.) | |
c906108c SS |
3292 | |
3293 | @table @code | |
3294 | @kindex continue | |
41afff9a EZ |
3295 | @kindex c @r{(@code{continue})} |
3296 | @kindex fg @r{(resume foreground execution)} | |
c906108c SS |
3297 | @item continue @r{[}@var{ignore-count}@r{]} |
3298 | @itemx c @r{[}@var{ignore-count}@r{]} | |
3299 | @itemx fg @r{[}@var{ignore-count}@r{]} | |
3300 | Resume program execution, at the address where your program last stopped; | |
3301 | any breakpoints set at that address are bypassed. The optional argument | |
3302 | @var{ignore-count} allows you to specify a further number of times to | |
3303 | ignore a breakpoint at this location; its effect is like that of | |
3304 | @code{ignore} (@pxref{Conditions, ,Break conditions}). | |
3305 | ||
3306 | The argument @var{ignore-count} is meaningful only when your program | |
3307 | stopped due to a breakpoint. At other times, the argument to | |
3308 | @code{continue} is ignored. | |
3309 | ||
d4f3574e SS |
3310 | The synonyms @code{c} and @code{fg} (for @dfn{foreground}, as the |
3311 | debugged program is deemed to be the foreground program) are provided | |
3312 | purely for convenience, and have exactly the same behavior as | |
3313 | @code{continue}. | |
c906108c SS |
3314 | @end table |
3315 | ||
3316 | To resume execution at a different place, you can use @code{return} | |
3317 | (@pxref{Returning, ,Returning from a function}) to go back to the | |
3318 | calling function; or @code{jump} (@pxref{Jumping, ,Continuing at a | |
3319 | different address}) to go to an arbitrary location in your program. | |
3320 | ||
3321 | A typical technique for using stepping is to set a breakpoint | |
3322 | (@pxref{Breakpoints, ,Breakpoints; watchpoints; and catchpoints}) at the | |
3323 | beginning of the function or the section of your program where a problem | |
3324 | is believed to lie, run your program until it stops at that breakpoint, | |
3325 | and then step through the suspect area, examining the variables that are | |
3326 | interesting, until you see the problem happen. | |
3327 | ||
3328 | @table @code | |
3329 | @kindex step | |
41afff9a | 3330 | @kindex s @r{(@code{step})} |
c906108c SS |
3331 | @item step |
3332 | Continue running your program until control reaches a different source | |
3333 | line, then stop it and return control to @value{GDBN}. This command is | |
3334 | abbreviated @code{s}. | |
3335 | ||
3336 | @quotation | |
3337 | @c "without debugging information" is imprecise; actually "without line | |
3338 | @c numbers in the debugging information". (gcc -g1 has debugging info but | |
3339 | @c not line numbers). But it seems complex to try to make that | |
3340 | @c distinction here. | |
3341 | @emph{Warning:} If you use the @code{step} command while control is | |
3342 | within a function that was compiled without debugging information, | |
3343 | execution proceeds until control reaches a function that does have | |
3344 | debugging information. Likewise, it will not step into a function which | |
3345 | is compiled without debugging information. To step through functions | |
3346 | without debugging information, use the @code{stepi} command, described | |
3347 | below. | |
3348 | @end quotation | |
3349 | ||
4a92d011 EZ |
3350 | The @code{step} command only stops at the first instruction of a source |
3351 | line. This prevents the multiple stops that could otherwise occur in | |
3352 | @code{switch} statements, @code{for} loops, etc. @code{step} continues | |
3353 | to stop if a function that has debugging information is called within | |
3354 | the line. In other words, @code{step} @emph{steps inside} any functions | |
3355 | called within the line. | |
c906108c | 3356 | |
d4f3574e SS |
3357 | Also, the @code{step} command only enters a function if there is line |
3358 | number information for the function. Otherwise it acts like the | |
5d161b24 | 3359 | @code{next} command. This avoids problems when using @code{cc -gl} |
c906108c | 3360 | on MIPS machines. Previously, @code{step} entered subroutines if there |
5d161b24 | 3361 | was any debugging information about the routine. |
c906108c SS |
3362 | |
3363 | @item step @var{count} | |
3364 | Continue running as in @code{step}, but do so @var{count} times. If a | |
7a292a7a SS |
3365 | breakpoint is reached, or a signal not related to stepping occurs before |
3366 | @var{count} steps, stepping stops right away. | |
c906108c SS |
3367 | |
3368 | @kindex next | |
41afff9a | 3369 | @kindex n @r{(@code{next})} |
c906108c SS |
3370 | @item next @r{[}@var{count}@r{]} |
3371 | Continue to the next source line in the current (innermost) stack frame. | |
7a292a7a SS |
3372 | This is similar to @code{step}, but function calls that appear within |
3373 | the line of code are executed without stopping. Execution stops when | |
3374 | control reaches a different line of code at the original stack level | |
3375 | that was executing when you gave the @code{next} command. This command | |
3376 | is abbreviated @code{n}. | |
c906108c SS |
3377 | |
3378 | An argument @var{count} is a repeat count, as for @code{step}. | |
3379 | ||
3380 | ||
3381 | @c FIX ME!! Do we delete this, or is there a way it fits in with | |
3382 | @c the following paragraph? --- Vctoria | |
3383 | @c | |
3384 | @c @code{next} within a function that lacks debugging information acts like | |
3385 | @c @code{step}, but any function calls appearing within the code of the | |
3386 | @c function are executed without stopping. | |
3387 | ||
d4f3574e SS |
3388 | The @code{next} command only stops at the first instruction of a |
3389 | source line. This prevents multiple stops that could otherwise occur in | |
4a92d011 | 3390 | @code{switch} statements, @code{for} loops, etc. |
c906108c | 3391 | |
b90a5f51 CF |
3392 | @kindex set step-mode |
3393 | @item set step-mode | |
3394 | @cindex functions without line info, and stepping | |
3395 | @cindex stepping into functions with no line info | |
3396 | @itemx set step-mode on | |
4a92d011 | 3397 | The @code{set step-mode on} command causes the @code{step} command to |
b90a5f51 CF |
3398 | stop at the first instruction of a function which contains no debug line |
3399 | information rather than stepping over it. | |
3400 | ||
4a92d011 EZ |
3401 | This is useful in cases where you may be interested in inspecting the |
3402 | machine instructions of a function which has no symbolic info and do not | |
3403 | want @value{GDBN} to automatically skip over this function. | |
b90a5f51 CF |
3404 | |
3405 | @item set step-mode off | |
4a92d011 | 3406 | Causes the @code{step} command to step over any functions which contains no |
b90a5f51 CF |
3407 | debug information. This is the default. |
3408 | ||
c906108c SS |
3409 | @kindex finish |
3410 | @item finish | |
3411 | Continue running until just after function in the selected stack frame | |
3412 | returns. Print the returned value (if any). | |
3413 | ||
3414 | Contrast this with the @code{return} command (@pxref{Returning, | |
3415 | ,Returning from a function}). | |
3416 | ||
3417 | @kindex until | |
41afff9a | 3418 | @kindex u @r{(@code{until})} |
c906108c SS |
3419 | @item until |
3420 | @itemx u | |
3421 | Continue running until a source line past the current line, in the | |
3422 | current stack frame, is reached. This command is used to avoid single | |
3423 | stepping through a loop more than once. It is like the @code{next} | |
3424 | command, except that when @code{until} encounters a jump, it | |
3425 | automatically continues execution until the program counter is greater | |
3426 | than the address of the jump. | |
3427 | ||
3428 | This means that when you reach the end of a loop after single stepping | |
3429 | though it, @code{until} makes your program continue execution until it | |
3430 | exits the loop. In contrast, a @code{next} command at the end of a loop | |
3431 | simply steps back to the beginning of the loop, which forces you to step | |
3432 | through the next iteration. | |
3433 | ||
3434 | @code{until} always stops your program if it attempts to exit the current | |
3435 | stack frame. | |
3436 | ||
3437 | @code{until} may produce somewhat counterintuitive results if the order | |
3438 | of machine code does not match the order of the source lines. For | |
3439 | example, in the following excerpt from a debugging session, the @code{f} | |
3440 | (@code{frame}) command shows that execution is stopped at line | |
3441 | @code{206}; yet when we use @code{until}, we get to line @code{195}: | |
3442 | ||
474c8240 | 3443 | @smallexample |
c906108c SS |
3444 | (@value{GDBP}) f |
3445 | #0 main (argc=4, argv=0xf7fffae8) at m4.c:206 | |
3446 | 206 expand_input(); | |
3447 | (@value{GDBP}) until | |
3448 | 195 for ( ; argc > 0; NEXTARG) @{ | |
474c8240 | 3449 | @end smallexample |
c906108c SS |
3450 | |
3451 | This happened because, for execution efficiency, the compiler had | |
3452 | generated code for the loop closure test at the end, rather than the | |
3453 | start, of the loop---even though the test in a C @code{for}-loop is | |
3454 | written before the body of the loop. The @code{until} command appeared | |
3455 | to step back to the beginning of the loop when it advanced to this | |
3456 | expression; however, it has not really gone to an earlier | |
3457 | statement---not in terms of the actual machine code. | |
3458 | ||
3459 | @code{until} with no argument works by means of single | |
3460 | instruction stepping, and hence is slower than @code{until} with an | |
3461 | argument. | |
3462 | ||
3463 | @item until @var{location} | |
3464 | @itemx u @var{location} | |
3465 | Continue running your program until either the specified location is | |
3466 | reached, or the current stack frame returns. @var{location} is any of | |
3467 | the forms of argument acceptable to @code{break} (@pxref{Set Breaks, | |
c60eb6f1 EZ |
3468 | ,Setting breakpoints}). This form of the command uses breakpoints, and |
3469 | hence is quicker than @code{until} without an argument. The specified | |
3470 | location is actually reached only if it is in the current frame. This | |
3471 | implies that @code{until} can be used to skip over recursive function | |
3472 | invocations. For instance in the code below, if the current location is | |
3473 | line @code{96}, issuing @code{until 99} will execute the program up to | |
3474 | line @code{99} in the same invocation of factorial, i.e. after the inner | |
3475 | invocations have returned. | |
3476 | ||
3477 | @smallexample | |
3478 | 94 int factorial (int value) | |
3479 | 95 @{ | |
3480 | 96 if (value > 1) @{ | |
3481 | 97 value *= factorial (value - 1); | |
3482 | 98 @} | |
3483 | 99 return (value); | |
3484 | 100 @} | |
3485 | @end smallexample | |
3486 | ||
3487 | ||
3488 | @kindex advance @var{location} | |
3489 | @itemx advance @var{location} | |
3490 | Continue running the program up to the given location. An argument is | |
3491 | required, anything of the same form as arguments for the @code{break} | |
3492 | command. Execution will also stop upon exit from the current stack | |
3493 | frame. This command is similar to @code{until}, but @code{advance} will | |
3494 | not skip over recursive function calls, and the target location doesn't | |
3495 | have to be in the same frame as the current one. | |
3496 | ||
c906108c SS |
3497 | |
3498 | @kindex stepi | |
41afff9a | 3499 | @kindex si @r{(@code{stepi})} |
c906108c | 3500 | @item stepi |
96a2c332 | 3501 | @itemx stepi @var{arg} |
c906108c SS |
3502 | @itemx si |
3503 | Execute one machine instruction, then stop and return to the debugger. | |
3504 | ||
3505 | It is often useful to do @samp{display/i $pc} when stepping by machine | |
3506 | instructions. This makes @value{GDBN} automatically display the next | |
3507 | instruction to be executed, each time your program stops. @xref{Auto | |
3508 | Display,, Automatic display}. | |
3509 | ||
3510 | An argument is a repeat count, as in @code{step}. | |
3511 | ||
3512 | @need 750 | |
3513 | @kindex nexti | |
41afff9a | 3514 | @kindex ni @r{(@code{nexti})} |
c906108c | 3515 | @item nexti |
96a2c332 | 3516 | @itemx nexti @var{arg} |
c906108c SS |
3517 | @itemx ni |
3518 | Execute one machine instruction, but if it is a function call, | |
3519 | proceed until the function returns. | |
3520 | ||
3521 | An argument is a repeat count, as in @code{next}. | |
3522 | @end table | |
3523 | ||
6d2ebf8b | 3524 | @node Signals |
c906108c SS |
3525 | @section Signals |
3526 | @cindex signals | |
3527 | ||
3528 | A signal is an asynchronous event that can happen in a program. The | |
3529 | operating system defines the possible kinds of signals, and gives each | |
3530 | kind a name and a number. For example, in Unix @code{SIGINT} is the | |
d4f3574e | 3531 | signal a program gets when you type an interrupt character (often @kbd{C-c}); |
c906108c SS |
3532 | @code{SIGSEGV} is the signal a program gets from referencing a place in |
3533 | memory far away from all the areas in use; @code{SIGALRM} occurs when | |
3534 | the alarm clock timer goes off (which happens only if your program has | |
3535 | requested an alarm). | |
3536 | ||
3537 | @cindex fatal signals | |
3538 | Some signals, including @code{SIGALRM}, are a normal part of the | |
3539 | functioning of your program. Others, such as @code{SIGSEGV}, indicate | |
d4f3574e | 3540 | errors; these signals are @dfn{fatal} (they kill your program immediately) if the |
c906108c SS |
3541 | program has not specified in advance some other way to handle the signal. |
3542 | @code{SIGINT} does not indicate an error in your program, but it is normally | |
3543 | fatal so it can carry out the purpose of the interrupt: to kill the program. | |
3544 | ||
3545 | @value{GDBN} has the ability to detect any occurrence of a signal in your | |
3546 | program. You can tell @value{GDBN} in advance what to do for each kind of | |
3547 | signal. | |
3548 | ||
3549 | @cindex handling signals | |
24f93129 EZ |
3550 | Normally, @value{GDBN} is set up to let the non-erroneous signals like |
3551 | @code{SIGALRM} be silently passed to your program | |
3552 | (so as not to interfere with their role in the program's functioning) | |
c906108c SS |
3553 | but to stop your program immediately whenever an error signal happens. |
3554 | You can change these settings with the @code{handle} command. | |
3555 | ||
3556 | @table @code | |
3557 | @kindex info signals | |
3558 | @item info signals | |
96a2c332 | 3559 | @itemx info handle |
c906108c SS |
3560 | Print a table of all the kinds of signals and how @value{GDBN} has been told to |
3561 | handle each one. You can use this to see the signal numbers of all | |
3562 | the defined types of signals. | |
3563 | ||
d4f3574e | 3564 | @code{info handle} is an alias for @code{info signals}. |
c906108c SS |
3565 | |
3566 | @kindex handle | |
3567 | @item handle @var{signal} @var{keywords}@dots{} | |
5ece1a18 EZ |
3568 | Change the way @value{GDBN} handles signal @var{signal}. @var{signal} |
3569 | can be the number of a signal or its name (with or without the | |
24f93129 | 3570 | @samp{SIG} at the beginning); a list of signal numbers of the form |
5ece1a18 EZ |
3571 | @samp{@var{low}-@var{high}}; or the word @samp{all}, meaning all the |
3572 | known signals. The @var{keywords} say what change to make. | |
c906108c SS |
3573 | @end table |
3574 | ||
3575 | @c @group | |
3576 | The keywords allowed by the @code{handle} command can be abbreviated. | |
3577 | Their full names are: | |
3578 | ||
3579 | @table @code | |
3580 | @item nostop | |
3581 | @value{GDBN} should not stop your program when this signal happens. It may | |
3582 | still print a message telling you that the signal has come in. | |
3583 | ||
3584 | @item stop | |
3585 | @value{GDBN} should stop your program when this signal happens. This implies | |
3586 | the @code{print} keyword as well. | |
3587 | ||
3588 | @item print | |
3589 | @value{GDBN} should print a message when this signal happens. | |
3590 | ||
3591 | @item noprint | |
3592 | @value{GDBN} should not mention the occurrence of the signal at all. This | |
3593 | implies the @code{nostop} keyword as well. | |
3594 | ||
3595 | @item pass | |
5ece1a18 | 3596 | @itemx noignore |
c906108c SS |
3597 | @value{GDBN} should allow your program to see this signal; your program |
3598 | can handle the signal, or else it may terminate if the signal is fatal | |
5ece1a18 | 3599 | and not handled. @code{pass} and @code{noignore} are synonyms. |
c906108c SS |
3600 | |
3601 | @item nopass | |
5ece1a18 | 3602 | @itemx ignore |
c906108c | 3603 | @value{GDBN} should not allow your program to see this signal. |
5ece1a18 | 3604 | @code{nopass} and @code{ignore} are synonyms. |
c906108c SS |
3605 | @end table |
3606 | @c @end group | |
3607 | ||
d4f3574e SS |
3608 | When a signal stops your program, the signal is not visible to the |
3609 | program until you | |
c906108c SS |
3610 | continue. Your program sees the signal then, if @code{pass} is in |
3611 | effect for the signal in question @emph{at that time}. In other words, | |
3612 | after @value{GDBN} reports a signal, you can use the @code{handle} | |
3613 | command with @code{pass} or @code{nopass} to control whether your | |
3614 | program sees that signal when you continue. | |
3615 | ||
24f93129 EZ |
3616 | The default is set to @code{nostop}, @code{noprint}, @code{pass} for |
3617 | non-erroneous signals such as @code{SIGALRM}, @code{SIGWINCH} and | |
3618 | @code{SIGCHLD}, and to @code{stop}, @code{print}, @code{pass} for the | |
3619 | erroneous signals. | |
3620 | ||
c906108c SS |
3621 | You can also use the @code{signal} command to prevent your program from |
3622 | seeing a signal, or cause it to see a signal it normally would not see, | |
3623 | or to give it any signal at any time. For example, if your program stopped | |
3624 | due to some sort of memory reference error, you might store correct | |
3625 | values into the erroneous variables and continue, hoping to see more | |
3626 | execution; but your program would probably terminate immediately as | |
3627 | a result of the fatal signal once it saw the signal. To prevent this, | |
3628 | you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your | |
5d161b24 | 3629 | program a signal}. |
c906108c | 3630 | |
6d2ebf8b | 3631 | @node Thread Stops |
c906108c SS |
3632 | @section Stopping and starting multi-thread programs |
3633 | ||
3634 | When your program has multiple threads (@pxref{Threads,, Debugging | |
3635 | programs with multiple threads}), you can choose whether to set | |
3636 | breakpoints on all threads, or on a particular thread. | |
3637 | ||
3638 | @table @code | |
3639 | @cindex breakpoints and threads | |
3640 | @cindex thread breakpoints | |
3641 | @kindex break @dots{} thread @var{threadno} | |
3642 | @item break @var{linespec} thread @var{threadno} | |
3643 | @itemx break @var{linespec} thread @var{threadno} if @dots{} | |
3644 | @var{linespec} specifies source lines; there are several ways of | |
3645 | writing them, but the effect is always to specify some source line. | |
3646 | ||
3647 | Use the qualifier @samp{thread @var{threadno}} with a breakpoint command | |
3648 | to specify that you only want @value{GDBN} to stop the program when a | |
3649 | particular thread reaches this breakpoint. @var{threadno} is one of the | |
3650 | numeric thread identifiers assigned by @value{GDBN}, shown in the first | |
3651 | column of the @samp{info threads} display. | |
3652 | ||
3653 | If you do not specify @samp{thread @var{threadno}} when you set a | |
3654 | breakpoint, the breakpoint applies to @emph{all} threads of your | |
3655 | program. | |
3656 | ||
3657 | You can use the @code{thread} qualifier on conditional breakpoints as | |
3658 | well; in this case, place @samp{thread @var{threadno}} before the | |
3659 | breakpoint condition, like this: | |
3660 | ||
3661 | @smallexample | |
2df3850c | 3662 | (@value{GDBP}) break frik.c:13 thread 28 if bartab > lim |
c906108c SS |
3663 | @end smallexample |
3664 | ||
3665 | @end table | |
3666 | ||
3667 | @cindex stopped threads | |
3668 | @cindex threads, stopped | |
3669 | Whenever your program stops under @value{GDBN} for any reason, | |
3670 | @emph{all} threads of execution stop, not just the current thread. This | |
3671 | allows you to examine the overall state of the program, including | |
3672 | switching between threads, without worrying that things may change | |
3673 | underfoot. | |
3674 | ||
3675 | @cindex continuing threads | |
3676 | @cindex threads, continuing | |
3677 | Conversely, whenever you restart the program, @emph{all} threads start | |
3678 | executing. @emph{This is true even when single-stepping} with commands | |
5d161b24 | 3679 | like @code{step} or @code{next}. |
c906108c SS |
3680 | |
3681 | In particular, @value{GDBN} cannot single-step all threads in lockstep. | |
3682 | Since thread scheduling is up to your debugging target's operating | |
3683 | system (not controlled by @value{GDBN}), other threads may | |
3684 | execute more than one statement while the current thread completes a | |
3685 | single step. Moreover, in general other threads stop in the middle of a | |
3686 | statement, rather than at a clean statement boundary, when the program | |
3687 | stops. | |
3688 | ||
3689 | You might even find your program stopped in another thread after | |
3690 | continuing or even single-stepping. This happens whenever some other | |
3691 | thread runs into a breakpoint, a signal, or an exception before the | |
3692 | first thread completes whatever you requested. | |
3693 | ||
3694 | On some OSes, you can lock the OS scheduler and thus allow only a single | |
3695 | thread to run. | |
3696 | ||
3697 | @table @code | |
3698 | @item set scheduler-locking @var{mode} | |
3699 | Set the scheduler locking mode. If it is @code{off}, then there is no | |
3700 | locking and any thread may run at any time. If @code{on}, then only the | |
3701 | current thread may run when the inferior is resumed. The @code{step} | |
3702 | mode optimizes for single-stepping. It stops other threads from | |
3703 | ``seizing the prompt'' by preempting the current thread while you are | |
3704 | stepping. Other threads will only rarely (or never) get a chance to run | |
d4f3574e | 3705 | when you step. They are more likely to run when you @samp{next} over a |
c906108c | 3706 | function call, and they are completely free to run when you use commands |
d4f3574e | 3707 | like @samp{continue}, @samp{until}, or @samp{finish}. However, unless another |
c906108c | 3708 | thread hits a breakpoint during its timeslice, they will never steal the |
2df3850c | 3709 | @value{GDBN} prompt away from the thread that you are debugging. |
c906108c SS |
3710 | |
3711 | @item show scheduler-locking | |
3712 | Display the current scheduler locking mode. | |
3713 | @end table | |
3714 | ||
c906108c | 3715 | |
6d2ebf8b | 3716 | @node Stack |
c906108c SS |
3717 | @chapter Examining the Stack |
3718 | ||
3719 | When your program has stopped, the first thing you need to know is where it | |
3720 | stopped and how it got there. | |
3721 | ||
3722 | @cindex call stack | |
5d161b24 DB |
3723 | Each time your program performs a function call, information about the call |
3724 | is generated. | |
3725 | That information includes the location of the call in your program, | |
3726 | the arguments of the call, | |
c906108c | 3727 | and the local variables of the function being called. |
5d161b24 | 3728 | The information is saved in a block of data called a @dfn{stack frame}. |
c906108c SS |
3729 | The stack frames are allocated in a region of memory called the @dfn{call |
3730 | stack}. | |
3731 | ||
3732 | When your program stops, the @value{GDBN} commands for examining the | |
3733 | stack allow you to see all of this information. | |
3734 | ||
3735 | @cindex selected frame | |
3736 | One of the stack frames is @dfn{selected} by @value{GDBN} and many | |
3737 | @value{GDBN} commands refer implicitly to the selected frame. In | |
3738 | particular, whenever you ask @value{GDBN} for the value of a variable in | |
3739 | your program, the value is found in the selected frame. There are | |
3740 | special @value{GDBN} commands to select whichever frame you are | |
3741 | interested in. @xref{Selection, ,Selecting a frame}. | |
3742 | ||
3743 | When your program stops, @value{GDBN} automatically selects the | |
5d161b24 | 3744 | currently executing frame and describes it briefly, similar to the |
c906108c SS |
3745 | @code{frame} command (@pxref{Frame Info, ,Information about a frame}). |
3746 | ||
3747 | @menu | |
3748 | * Frames:: Stack frames | |
3749 | * Backtrace:: Backtraces | |
3750 | * Selection:: Selecting a frame | |
3751 | * Frame Info:: Information on a frame | |
c906108c SS |
3752 | |
3753 | @end menu | |
3754 | ||
6d2ebf8b | 3755 | @node Frames |
c906108c SS |
3756 | @section Stack frames |
3757 | ||
d4f3574e | 3758 | @cindex frame, definition |
c906108c SS |
3759 | @cindex stack frame |
3760 | The call stack is divided up into contiguous pieces called @dfn{stack | |
3761 | frames}, or @dfn{frames} for short; each frame is the data associated | |
3762 | with one call to one function. The frame contains the arguments given | |
3763 | to the function, the function's local variables, and the address at | |
3764 | which the function is executing. | |
3765 | ||
3766 | @cindex initial frame | |
3767 | @cindex outermost frame | |
3768 | @cindex innermost frame | |
3769 | When your program is started, the stack has only one frame, that of the | |
3770 | function @code{main}. This is called the @dfn{initial} frame or the | |
3771 | @dfn{outermost} frame. Each time a function is called, a new frame is | |
3772 | made. Each time a function returns, the frame for that function invocation | |
3773 | is eliminated. If a function is recursive, there can be many frames for | |
3774 | the same function. The frame for the function in which execution is | |
3775 | actually occurring is called the @dfn{innermost} frame. This is the most | |
3776 | recently created of all the stack frames that still exist. | |
3777 | ||
3778 | @cindex frame pointer | |
3779 | Inside your program, stack frames are identified by their addresses. A | |
3780 | stack frame consists of many bytes, each of which has its own address; each | |
3781 | kind of computer has a convention for choosing one byte whose | |
3782 | address serves as the address of the frame. Usually this address is kept | |
3783 | in a register called the @dfn{frame pointer register} while execution is | |
3784 | going on in that frame. | |
3785 | ||
3786 | @cindex frame number | |
3787 | @value{GDBN} assigns numbers to all existing stack frames, starting with | |
3788 | zero for the innermost frame, one for the frame that called it, | |
3789 | and so on upward. These numbers do not really exist in your program; | |
3790 | they are assigned by @value{GDBN} to give you a way of designating stack | |
3791 | frames in @value{GDBN} commands. | |
3792 | ||
6d2ebf8b SS |
3793 | @c The -fomit-frame-pointer below perennially causes hbox overflow |
3794 | @c underflow problems. | |
c906108c SS |
3795 | @cindex frameless execution |
3796 | Some compilers provide a way to compile functions so that they operate | |
6d2ebf8b | 3797 | without stack frames. (For example, the @value{GCC} option |
474c8240 | 3798 | @smallexample |
6d2ebf8b | 3799 | @samp{-fomit-frame-pointer} |
474c8240 | 3800 | @end smallexample |
6d2ebf8b | 3801 | generates functions without a frame.) |
c906108c SS |
3802 | This is occasionally done with heavily used library functions to save |
3803 | the frame setup time. @value{GDBN} has limited facilities for dealing | |
3804 | with these function invocations. If the innermost function invocation | |
3805 | has no stack frame, @value{GDBN} nevertheless regards it as though | |
3806 | it had a separate frame, which is numbered zero as usual, allowing | |
3807 | correct tracing of the function call chain. However, @value{GDBN} has | |
3808 | no provision for frameless functions elsewhere in the stack. | |
3809 | ||
3810 | @table @code | |
d4f3574e | 3811 | @kindex frame@r{, command} |
41afff9a | 3812 | @cindex current stack frame |
c906108c | 3813 | @item frame @var{args} |
5d161b24 | 3814 | The @code{frame} command allows you to move from one stack frame to another, |
c906108c | 3815 | and to print the stack frame you select. @var{args} may be either the |
5d161b24 DB |
3816 | address of the frame or the stack frame number. Without an argument, |
3817 | @code{frame} prints the current stack frame. | |
c906108c SS |
3818 | |
3819 | @kindex select-frame | |
41afff9a | 3820 | @cindex selecting frame silently |
c906108c SS |
3821 | @item select-frame |
3822 | The @code{select-frame} command allows you to move from one stack frame | |
3823 | to another without printing the frame. This is the silent version of | |
3824 | @code{frame}. | |
3825 | @end table | |
3826 | ||
6d2ebf8b | 3827 | @node Backtrace |
c906108c SS |
3828 | @section Backtraces |
3829 | ||
3830 | @cindex backtraces | |
3831 | @cindex tracebacks | |
3832 | @cindex stack traces | |
3833 | A backtrace is a summary of how your program got where it is. It shows one | |
3834 | line per frame, for many frames, starting with the currently executing | |
3835 | frame (frame zero), followed by its caller (frame one), and on up the | |
3836 | stack. | |
3837 | ||
3838 | @table @code | |
3839 | @kindex backtrace | |
41afff9a | 3840 | @kindex bt @r{(@code{backtrace})} |
c906108c SS |
3841 | @item backtrace |
3842 | @itemx bt | |
3843 | Print a backtrace of the entire stack: one line per frame for all | |
3844 | frames in the stack. | |
3845 | ||
3846 | You can stop the backtrace at any time by typing the system interrupt | |
3847 | character, normally @kbd{C-c}. | |
3848 | ||
3849 | @item backtrace @var{n} | |
3850 | @itemx bt @var{n} | |
3851 | Similar, but print only the innermost @var{n} frames. | |
3852 | ||
3853 | @item backtrace -@var{n} | |
3854 | @itemx bt -@var{n} | |
3855 | Similar, but print only the outermost @var{n} frames. | |
3856 | @end table | |
3857 | ||
3858 | @kindex where | |
3859 | @kindex info stack | |
41afff9a | 3860 | @kindex info s @r{(@code{info stack})} |
c906108c SS |
3861 | The names @code{where} and @code{info stack} (abbreviated @code{info s}) |
3862 | are additional aliases for @code{backtrace}. | |
3863 | ||
3864 | Each line in the backtrace shows the frame number and the function name. | |
3865 | The program counter value is also shown---unless you use @code{set | |
3866 | print address off}. The backtrace also shows the source file name and | |
3867 | line number, as well as the arguments to the function. The program | |
3868 | counter value is omitted if it is at the beginning of the code for that | |
3869 | line number. | |
3870 | ||
3871 | Here is an example of a backtrace. It was made with the command | |
3872 | @samp{bt 3}, so it shows the innermost three frames. | |
3873 | ||
3874 | @smallexample | |
3875 | @group | |
5d161b24 | 3876 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) |
c906108c SS |
3877 | at builtin.c:993 |
3878 | #1 0x6e38 in expand_macro (sym=0x2b600) at macro.c:242 | |
3879 | #2 0x6840 in expand_token (obs=0x0, t=177664, td=0xf7fffb08) | |
3880 | at macro.c:71 | |
3881 | (More stack frames follow...) | |
3882 | @end group | |
3883 | @end smallexample | |
3884 | ||
3885 | @noindent | |
3886 | The display for frame zero does not begin with a program counter | |
3887 | value, indicating that your program has stopped at the beginning of the | |
3888 | code for line @code{993} of @code{builtin.c}. | |
3889 | ||
b4e9345d DJ |
3890 | @kindex set backtrace-below-main |
3891 | @kindex show backtrace-below-main | |
3892 | ||
95f90d25 DJ |
3893 | Most programs have a standard entry point---a place where system libraries |
3894 | and startup code transition into user code. For C this is @code{main}. | |
3895 | When @value{GDBN} finds the entry function in a backtrace it will terminate | |
3896 | the backtrace, to avoid tracing into highly system-specific (and generally | |
3897 | uninteresting) code. If you need to examine the startup code, then you can | |
3898 | change this behavior. | |
3899 | ||
3900 | @table @code | |
3901 | @item set backtrace-below-main off | |
3902 | Backtraces will stop when they encounter the user entry point. This is the | |
3903 | default. | |
3904 | ||
3905 | @item set backtrace-below-main | |
3906 | @itemx set backtrace-below-main on | |
3907 | Backtraces will continue past the user entry point to the top of the stack. | |
3908 | ||
3909 | @item show backtrace-below-main | |
3910 | Display the current backtrace policy. | |
3911 | @end table | |
3912 | ||
6d2ebf8b | 3913 | @node Selection |
c906108c SS |
3914 | @section Selecting a frame |
3915 | ||
3916 | Most commands for examining the stack and other data in your program work on | |
3917 | whichever stack frame is selected at the moment. Here are the commands for | |
3918 | selecting a stack frame; all of them finish by printing a brief description | |
3919 | of the stack frame just selected. | |
3920 | ||
3921 | @table @code | |
d4f3574e | 3922 | @kindex frame@r{, selecting} |
41afff9a | 3923 | @kindex f @r{(@code{frame})} |
c906108c SS |
3924 | @item frame @var{n} |
3925 | @itemx f @var{n} | |
3926 | Select frame number @var{n}. Recall that frame zero is the innermost | |
3927 | (currently executing) frame, frame one is the frame that called the | |
3928 | innermost one, and so on. The highest-numbered frame is the one for | |
3929 | @code{main}. | |
3930 | ||
3931 | @item frame @var{addr} | |
3932 | @itemx f @var{addr} | |
3933 | Select the frame at address @var{addr}. This is useful mainly if the | |
3934 | chaining of stack frames has been damaged by a bug, making it | |
3935 | impossible for @value{GDBN} to assign numbers properly to all frames. In | |
3936 | addition, this can be useful when your program has multiple stacks and | |
3937 | switches between them. | |
3938 | ||
c906108c SS |
3939 | On the SPARC architecture, @code{frame} needs two addresses to |
3940 | select an arbitrary frame: a frame pointer and a stack pointer. | |
3941 | ||
3942 | On the MIPS and Alpha architecture, it needs two addresses: a stack | |
3943 | pointer and a program counter. | |
3944 | ||
3945 | On the 29k architecture, it needs three addresses: a register stack | |
3946 | pointer, a program counter, and a memory stack pointer. | |
3947 | @c note to future updaters: this is conditioned on a flag | |
3948 | @c SETUP_ARBITRARY_FRAME in the tm-*.h files. The above is up to date | |
3949 | @c as of 27 Jan 1994. | |
c906108c SS |
3950 | |
3951 | @kindex up | |
3952 | @item up @var{n} | |
3953 | Move @var{n} frames up the stack. For positive numbers @var{n}, this | |
3954 | advances toward the outermost frame, to higher frame numbers, to frames | |
3955 | that have existed longer. @var{n} defaults to one. | |
3956 | ||
3957 | @kindex down | |
41afff9a | 3958 | @kindex do @r{(@code{down})} |
c906108c SS |
3959 | @item down @var{n} |
3960 | Move @var{n} frames down the stack. For positive numbers @var{n}, this | |
3961 | advances toward the innermost frame, to lower frame numbers, to frames | |
3962 | that were created more recently. @var{n} defaults to one. You may | |
3963 | abbreviate @code{down} as @code{do}. | |
3964 | @end table | |
3965 | ||
3966 | All of these commands end by printing two lines of output describing the | |
3967 | frame. The first line shows the frame number, the function name, the | |
3968 | arguments, and the source file and line number of execution in that | |
5d161b24 | 3969 | frame. The second line shows the text of that source line. |
c906108c SS |
3970 | |
3971 | @need 1000 | |
3972 | For example: | |
3973 | ||
3974 | @smallexample | |
3975 | @group | |
3976 | (@value{GDBP}) up | |
3977 | #1 0x22f0 in main (argc=1, argv=0xf7fffbf4, env=0xf7fffbfc) | |
3978 | at env.c:10 | |
3979 | 10 read_input_file (argv[i]); | |
3980 | @end group | |
3981 | @end smallexample | |
3982 | ||
3983 | After such a printout, the @code{list} command with no arguments | |
3984 | prints ten lines centered on the point of execution in the frame. | |
87885426 FN |
3985 | You can also edit the program at the point of execution with your favorite |
3986 | editing program by typing @code{edit}. | |
3987 | @xref{List, ,Printing source lines}, | |
3988 | for details. | |
c906108c SS |
3989 | |
3990 | @table @code | |
3991 | @kindex down-silently | |
3992 | @kindex up-silently | |
3993 | @item up-silently @var{n} | |
3994 | @itemx down-silently @var{n} | |
3995 | These two commands are variants of @code{up} and @code{down}, | |
3996 | respectively; they differ in that they do their work silently, without | |
3997 | causing display of the new frame. They are intended primarily for use | |
3998 | in @value{GDBN} command scripts, where the output might be unnecessary and | |
3999 | distracting. | |
4000 | @end table | |
4001 | ||
6d2ebf8b | 4002 | @node Frame Info |
c906108c SS |
4003 | @section Information about a frame |
4004 | ||
4005 | There are several other commands to print information about the selected | |
4006 | stack frame. | |
4007 | ||
4008 | @table @code | |
4009 | @item frame | |
4010 | @itemx f | |
4011 | When used without any argument, this command does not change which | |
4012 | frame is selected, but prints a brief description of the currently | |
4013 | selected stack frame. It can be abbreviated @code{f}. With an | |
4014 | argument, this command is used to select a stack frame. | |
4015 | @xref{Selection, ,Selecting a frame}. | |
4016 | ||
4017 | @kindex info frame | |
41afff9a | 4018 | @kindex info f @r{(@code{info frame})} |
c906108c SS |
4019 | @item info frame |
4020 | @itemx info f | |
4021 | This command prints a verbose description of the selected stack frame, | |
4022 | including: | |
4023 | ||
4024 | @itemize @bullet | |
5d161b24 DB |
4025 | @item |
4026 | the address of the frame | |
c906108c SS |
4027 | @item |
4028 | the address of the next frame down (called by this frame) | |
4029 | @item | |
4030 | the address of the next frame up (caller of this frame) | |
4031 | @item | |
4032 | the language in which the source code corresponding to this frame is written | |
4033 | @item | |
4034 | the address of the frame's arguments | |
4035 | @item | |
d4f3574e SS |
4036 | the address of the frame's local variables |
4037 | @item | |
c906108c SS |
4038 | the program counter saved in it (the address of execution in the caller frame) |
4039 | @item | |
4040 | which registers were saved in the frame | |
4041 | @end itemize | |
4042 | ||
4043 | @noindent The verbose description is useful when | |
4044 | something has gone wrong that has made the stack format fail to fit | |
4045 | the usual conventions. | |
4046 | ||
4047 | @item info frame @var{addr} | |
4048 | @itemx info f @var{addr} | |
4049 | Print a verbose description of the frame at address @var{addr}, without | |
4050 | selecting that frame. The selected frame remains unchanged by this | |
4051 | command. This requires the same kind of address (more than one for some | |
4052 | architectures) that you specify in the @code{frame} command. | |
4053 | @xref{Selection, ,Selecting a frame}. | |
4054 | ||
4055 | @kindex info args | |
4056 | @item info args | |
4057 | Print the arguments of the selected frame, each on a separate line. | |
4058 | ||
4059 | @item info locals | |
4060 | @kindex info locals | |
4061 | Print the local variables of the selected frame, each on a separate | |
4062 | line. These are all variables (declared either static or automatic) | |
4063 | accessible at the point of execution of the selected frame. | |
4064 | ||
c906108c | 4065 | @kindex info catch |
d4f3574e SS |
4066 | @cindex catch exceptions, list active handlers |
4067 | @cindex exception handlers, how to list | |
c906108c SS |
4068 | @item info catch |
4069 | Print a list of all the exception handlers that are active in the | |
4070 | current stack frame at the current point of execution. To see other | |
4071 | exception handlers, visit the associated frame (using the @code{up}, | |
4072 | @code{down}, or @code{frame} commands); then type @code{info catch}. | |
4073 | @xref{Set Catchpoints, , Setting catchpoints}. | |
53a5351d | 4074 | |
c906108c SS |
4075 | @end table |
4076 | ||
c906108c | 4077 | |
6d2ebf8b | 4078 | @node Source |
c906108c SS |
4079 | @chapter Examining Source Files |
4080 | ||
4081 | @value{GDBN} can print parts of your program's source, since the debugging | |
4082 | information recorded in the program tells @value{GDBN} what source files were | |
4083 | used to build it. When your program stops, @value{GDBN} spontaneously prints | |
4084 | the line where it stopped. Likewise, when you select a stack frame | |
4085 | (@pxref{Selection, ,Selecting a frame}), @value{GDBN} prints the line where | |
4086 | execution in that frame has stopped. You can print other portions of | |
4087 | source files by explicit command. | |
4088 | ||
7a292a7a | 4089 | If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may |
d4f3574e | 4090 | prefer to use Emacs facilities to view source; see @ref{Emacs, ,Using |
7a292a7a | 4091 | @value{GDBN} under @sc{gnu} Emacs}. |
c906108c SS |
4092 | |
4093 | @menu | |
4094 | * List:: Printing source lines | |
87885426 | 4095 | * Edit:: Editing source files |
c906108c | 4096 | * Search:: Searching source files |
c906108c SS |
4097 | * Source Path:: Specifying source directories |
4098 | * Machine Code:: Source and machine code | |
4099 | @end menu | |
4100 | ||
6d2ebf8b | 4101 | @node List |
c906108c SS |
4102 | @section Printing source lines |
4103 | ||
4104 | @kindex list | |
41afff9a | 4105 | @kindex l @r{(@code{list})} |
c906108c | 4106 | To print lines from a source file, use the @code{list} command |
5d161b24 | 4107 | (abbreviated @code{l}). By default, ten lines are printed. |
c906108c SS |
4108 | There are several ways to specify what part of the file you want to print. |
4109 | ||
4110 | Here are the forms of the @code{list} command most commonly used: | |
4111 | ||
4112 | @table @code | |
4113 | @item list @var{linenum} | |
4114 | Print lines centered around line number @var{linenum} in the | |
4115 | current source file. | |
4116 | ||
4117 | @item list @var{function} | |
4118 | Print lines centered around the beginning of function | |
4119 | @var{function}. | |
4120 | ||
4121 | @item list | |
4122 | Print more lines. If the last lines printed were printed with a | |
4123 | @code{list} command, this prints lines following the last lines | |
4124 | printed; however, if the last line printed was a solitary line printed | |
4125 | as part of displaying a stack frame (@pxref{Stack, ,Examining the | |
4126 | Stack}), this prints lines centered around that line. | |
4127 | ||
4128 | @item list - | |
4129 | Print lines just before the lines last printed. | |
4130 | @end table | |
4131 | ||
4132 | By default, @value{GDBN} prints ten source lines with any of these forms of | |
4133 | the @code{list} command. You can change this using @code{set listsize}: | |
4134 | ||
4135 | @table @code | |
4136 | @kindex set listsize | |
4137 | @item set listsize @var{count} | |
4138 | Make the @code{list} command display @var{count} source lines (unless | |
4139 | the @code{list} argument explicitly specifies some other number). | |
4140 | ||
4141 | @kindex show listsize | |
4142 | @item show listsize | |
4143 | Display the number of lines that @code{list} prints. | |
4144 | @end table | |
4145 | ||
4146 | Repeating a @code{list} command with @key{RET} discards the argument, | |
4147 | so it is equivalent to typing just @code{list}. This is more useful | |
4148 | than listing the same lines again. An exception is made for an | |
4149 | argument of @samp{-}; that argument is preserved in repetition so that | |
4150 | each repetition moves up in the source file. | |
4151 | ||
4152 | @cindex linespec | |
4153 | In general, the @code{list} command expects you to supply zero, one or two | |
4154 | @dfn{linespecs}. Linespecs specify source lines; there are several ways | |
d4f3574e | 4155 | of writing them, but the effect is always to specify some source line. |
c906108c SS |
4156 | Here is a complete description of the possible arguments for @code{list}: |
4157 | ||
4158 | @table @code | |
4159 | @item list @var{linespec} | |
4160 | Print lines centered around the line specified by @var{linespec}. | |
4161 | ||
4162 | @item list @var{first},@var{last} | |
4163 | Print lines from @var{first} to @var{last}. Both arguments are | |
4164 | linespecs. | |
4165 | ||
4166 | @item list ,@var{last} | |
4167 | Print lines ending with @var{last}. | |
4168 | ||
4169 | @item list @var{first}, | |
4170 | Print lines starting with @var{first}. | |
4171 | ||
4172 | @item list + | |
4173 | Print lines just after the lines last printed. | |
4174 | ||
4175 | @item list - | |
4176 | Print lines just before the lines last printed. | |
4177 | ||
4178 | @item list | |
4179 | As described in the preceding table. | |
4180 | @end table | |
4181 | ||
4182 | Here are the ways of specifying a single source line---all the | |
4183 | kinds of linespec. | |
4184 | ||
4185 | @table @code | |
4186 | @item @var{number} | |
4187 | Specifies line @var{number} of the current source file. | |
4188 | When a @code{list} command has two linespecs, this refers to | |
4189 | the same source file as the first linespec. | |
4190 | ||
4191 | @item +@var{offset} | |
4192 | Specifies the line @var{offset} lines after the last line printed. | |
4193 | When used as the second linespec in a @code{list} command that has | |
4194 | two, this specifies the line @var{offset} lines down from the | |
4195 | first linespec. | |
4196 | ||
4197 | @item -@var{offset} | |
4198 | Specifies the line @var{offset} lines before the last line printed. | |
4199 | ||
4200 | @item @var{filename}:@var{number} | |
4201 | Specifies line @var{number} in the source file @var{filename}. | |
4202 | ||
4203 | @item @var{function} | |
4204 | Specifies the line that begins the body of the function @var{function}. | |
4205 | For example: in C, this is the line with the open brace. | |
4206 | ||
4207 | @item @var{filename}:@var{function} | |
4208 | Specifies the line of the open-brace that begins the body of the | |
4209 | function @var{function} in the file @var{filename}. You only need the | |
4210 | file name with a function name to avoid ambiguity when there are | |
4211 | identically named functions in different source files. | |
4212 | ||
4213 | @item *@var{address} | |
4214 | Specifies the line containing the program address @var{address}. | |
4215 | @var{address} may be any expression. | |
4216 | @end table | |
4217 | ||
87885426 FN |
4218 | @node Edit |
4219 | @section Editing source files | |
4220 | @cindex editing source files | |
4221 | ||
4222 | @kindex edit | |
4223 | @kindex e @r{(@code{edit})} | |
4224 | To edit the lines in a source file, use the @code{edit} command. | |
4225 | The editing program of your choice | |
4226 | is invoked with the current line set to | |
4227 | the active line in the program. | |
4228 | Alternatively, there are several ways to specify what part of the file you | |
4229 | want to print if you want to see other parts of the program. | |
4230 | ||
4231 | Here are the forms of the @code{edit} command most commonly used: | |
4232 | ||
4233 | @table @code | |
4234 | @item edit | |
4235 | Edit the current source file at the active line number in the program. | |
4236 | ||
4237 | @item edit @var{number} | |
4238 | Edit the current source file with @var{number} as the active line number. | |
4239 | ||
4240 | @item edit @var{function} | |
4241 | Edit the file containing @var{function} at the beginning of its definition. | |
4242 | ||
4243 | @item edit @var{filename}:@var{number} | |
4244 | Specifies line @var{number} in the source file @var{filename}. | |
4245 | ||
4246 | @item edit @var{filename}:@var{function} | |
4247 | Specifies the line that begins the body of the | |
4248 | function @var{function} in the file @var{filename}. You only need the | |
4249 | file name with a function name to avoid ambiguity when there are | |
4250 | identically named functions in different source files. | |
4251 | ||
4252 | @item edit *@var{address} | |
4253 | Specifies the line containing the program address @var{address}. | |
4254 | @var{address} may be any expression. | |
4255 | @end table | |
4256 | ||
4257 | @subsection Choosing your editor | |
4258 | You can customize @value{GDBN} to use any editor you want | |
4259 | @footnote{ | |
4260 | The only restriction is that your editor (say @code{ex}), recognizes the | |
4261 | following command-line syntax: | |
10998722 | 4262 | @smallexample |
87885426 | 4263 | ex +@var{number} file |
10998722 AC |
4264 | @end smallexample |
4265 | The optional numeric value +@var{number} designates the active line in | |
4266 | the file.}. By default, it is @value{EDITOR}, but you can change this | |
4267 | by setting the environment variable @code{EDITOR} before using | |
4268 | @value{GDBN}. For example, to configure @value{GDBN} to use the | |
4269 | @code{vi} editor, you could use these commands with the @code{sh} shell: | |
4270 | @smallexample | |
87885426 FN |
4271 | EDITOR=/usr/bin/vi |
4272 | export EDITOR | |
4273 | gdb ... | |
10998722 | 4274 | @end smallexample |
87885426 | 4275 | or in the @code{csh} shell, |
10998722 | 4276 | @smallexample |
87885426 FN |
4277 | setenv EDITOR /usr/bin/vi |
4278 | gdb ... | |
10998722 | 4279 | @end smallexample |
87885426 | 4280 | |
6d2ebf8b | 4281 | @node Search |
c906108c SS |
4282 | @section Searching source files |
4283 | @cindex searching | |
4284 | @kindex reverse-search | |
4285 | ||
4286 | There are two commands for searching through the current source file for a | |
4287 | regular expression. | |
4288 | ||
4289 | @table @code | |
4290 | @kindex search | |
4291 | @kindex forward-search | |
4292 | @item forward-search @var{regexp} | |
4293 | @itemx search @var{regexp} | |
4294 | The command @samp{forward-search @var{regexp}} checks each line, | |
4295 | starting with the one following the last line listed, for a match for | |
5d161b24 | 4296 | @var{regexp}. It lists the line that is found. You can use the |
c906108c SS |
4297 | synonym @samp{search @var{regexp}} or abbreviate the command name as |
4298 | @code{fo}. | |
4299 | ||
4300 | @item reverse-search @var{regexp} | |
4301 | The command @samp{reverse-search @var{regexp}} checks each line, starting | |
4302 | with the one before the last line listed and going backward, for a match | |
4303 | for @var{regexp}. It lists the line that is found. You can abbreviate | |
4304 | this command as @code{rev}. | |
4305 | @end table | |
c906108c | 4306 | |
6d2ebf8b | 4307 | @node Source Path |
c906108c SS |
4308 | @section Specifying source directories |
4309 | ||
4310 | @cindex source path | |
4311 | @cindex directories for source files | |
4312 | Executable programs sometimes do not record the directories of the source | |
4313 | files from which they were compiled, just the names. Even when they do, | |
4314 | the directories could be moved between the compilation and your debugging | |
4315 | session. @value{GDBN} has a list of directories to search for source files; | |
4316 | this is called the @dfn{source path}. Each time @value{GDBN} wants a source file, | |
4317 | it tries all the directories in the list, in the order they are present | |
4318 | in the list, until it finds a file with the desired name. Note that | |
4319 | the executable search path is @emph{not} used for this purpose. Neither is | |
4320 | the current working directory, unless it happens to be in the source | |
4321 | path. | |
4322 | ||
4323 | If @value{GDBN} cannot find a source file in the source path, and the | |
4324 | object program records a directory, @value{GDBN} tries that directory | |
4325 | too. If the source path is empty, and there is no record of the | |
4326 | compilation directory, @value{GDBN} looks in the current directory as a | |
4327 | last resort. | |
4328 | ||
4329 | Whenever you reset or rearrange the source path, @value{GDBN} clears out | |
4330 | any information it has cached about where source files are found and where | |
4331 | each line is in the file. | |
4332 | ||
4333 | @kindex directory | |
4334 | @kindex dir | |
d4f3574e SS |
4335 | When you start @value{GDBN}, its source path includes only @samp{cdir} |
4336 | and @samp{cwd}, in that order. | |
c906108c SS |
4337 | To add other directories, use the @code{directory} command. |
4338 | ||
4339 | @table @code | |
4340 | @item directory @var{dirname} @dots{} | |
4341 | @item dir @var{dirname} @dots{} | |
4342 | Add directory @var{dirname} to the front of the source path. Several | |
d4f3574e SS |
4343 | directory names may be given to this command, separated by @samp{:} |
4344 | (@samp{;} on MS-DOS and MS-Windows, where @samp{:} usually appears as | |
4345 | part of absolute file names) or | |
c906108c SS |
4346 | whitespace. You may specify a directory that is already in the source |
4347 | path; this moves it forward, so @value{GDBN} searches it sooner. | |
4348 | ||
4349 | @kindex cdir | |
4350 | @kindex cwd | |
41afff9a EZ |
4351 | @vindex $cdir@r{, convenience variable} |
4352 | @vindex $cwdr@r{, convenience variable} | |
c906108c SS |
4353 | @cindex compilation directory |
4354 | @cindex current directory | |
4355 | @cindex working directory | |
4356 | @cindex directory, current | |
4357 | @cindex directory, compilation | |
4358 | You can use the string @samp{$cdir} to refer to the compilation | |
4359 | directory (if one is recorded), and @samp{$cwd} to refer to the current | |
4360 | working directory. @samp{$cwd} is not the same as @samp{.}---the former | |
4361 | tracks the current working directory as it changes during your @value{GDBN} | |
4362 | session, while the latter is immediately expanded to the current | |
4363 | directory at the time you add an entry to the source path. | |
4364 | ||
4365 | @item directory | |
4366 | Reset the source path to empty again. This requires confirmation. | |
4367 | ||
4368 | @c RET-repeat for @code{directory} is explicitly disabled, but since | |
4369 | @c repeating it would be a no-op we do not say that. (thanks to RMS) | |
4370 | ||
4371 | @item show directories | |
4372 | @kindex show directories | |
4373 | Print the source path: show which directories it contains. | |
4374 | @end table | |
4375 | ||
4376 | If your source path is cluttered with directories that are no longer of | |
4377 | interest, @value{GDBN} may sometimes cause confusion by finding the wrong | |
4378 | versions of source. You can correct the situation as follows: | |
4379 | ||
4380 | @enumerate | |
4381 | @item | |
4382 | Use @code{directory} with no argument to reset the source path to empty. | |
4383 | ||
4384 | @item | |
4385 | Use @code{directory} with suitable arguments to reinstall the | |
4386 | directories you want in the source path. You can add all the | |
4387 | directories in one command. | |
4388 | @end enumerate | |
4389 | ||
6d2ebf8b | 4390 | @node Machine Code |
c906108c SS |
4391 | @section Source and machine code |
4392 | ||
4393 | You can use the command @code{info line} to map source lines to program | |
4394 | addresses (and vice versa), and the command @code{disassemble} to display | |
4395 | a range of addresses as machine instructions. When run under @sc{gnu} Emacs | |
d4f3574e | 4396 | mode, the @code{info line} command causes the arrow to point to the |
5d161b24 | 4397 | line specified. Also, @code{info line} prints addresses in symbolic form as |
c906108c SS |
4398 | well as hex. |
4399 | ||
4400 | @table @code | |
4401 | @kindex info line | |
4402 | @item info line @var{linespec} | |
4403 | Print the starting and ending addresses of the compiled code for | |
4404 | source line @var{linespec}. You can specify source lines in any of | |
4405 | the ways understood by the @code{list} command (@pxref{List, ,Printing | |
4406 | source lines}). | |
4407 | @end table | |
4408 | ||
4409 | For example, we can use @code{info line} to discover the location of | |
4410 | the object code for the first line of function | |
4411 | @code{m4_changequote}: | |
4412 | ||
d4f3574e SS |
4413 | @c FIXME: I think this example should also show the addresses in |
4414 | @c symbolic form, as they usually would be displayed. | |
c906108c | 4415 | @smallexample |
96a2c332 | 4416 | (@value{GDBP}) info line m4_changequote |
c906108c SS |
4417 | Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350. |
4418 | @end smallexample | |
4419 | ||
4420 | @noindent | |
4421 | We can also inquire (using @code{*@var{addr}} as the form for | |
4422 | @var{linespec}) what source line covers a particular address: | |
4423 | @smallexample | |
4424 | (@value{GDBP}) info line *0x63ff | |
4425 | Line 926 of "builtin.c" starts at pc 0x63e4 and ends at 0x6404. | |
4426 | @end smallexample | |
4427 | ||
4428 | @cindex @code{$_} and @code{info line} | |
41afff9a | 4429 | @kindex x@r{(examine), and} info line |
c906108c SS |
4430 | After @code{info line}, the default address for the @code{x} command |
4431 | is changed to the starting address of the line, so that @samp{x/i} is | |
4432 | sufficient to begin examining the machine code (@pxref{Memory, | |
4433 | ,Examining memory}). Also, this address is saved as the value of the | |
4434 | convenience variable @code{$_} (@pxref{Convenience Vars, ,Convenience | |
4435 | variables}). | |
4436 | ||
4437 | @table @code | |
4438 | @kindex disassemble | |
4439 | @cindex assembly instructions | |
4440 | @cindex instructions, assembly | |
4441 | @cindex machine instructions | |
4442 | @cindex listing machine instructions | |
4443 | @item disassemble | |
4444 | This specialized command dumps a range of memory as machine | |
4445 | instructions. The default memory range is the function surrounding the | |
4446 | program counter of the selected frame. A single argument to this | |
4447 | command is a program counter value; @value{GDBN} dumps the function | |
4448 | surrounding this value. Two arguments specify a range of addresses | |
4449 | (first inclusive, second exclusive) to dump. | |
4450 | @end table | |
4451 | ||
c906108c SS |
4452 | The following example shows the disassembly of a range of addresses of |
4453 | HP PA-RISC 2.0 code: | |
4454 | ||
4455 | @smallexample | |
4456 | (@value{GDBP}) disas 0x32c4 0x32e4 | |
4457 | Dump of assembler code from 0x32c4 to 0x32e4: | |
4458 | 0x32c4 <main+204>: addil 0,dp | |
4459 | 0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26 | |
4460 | 0x32cc <main+212>: ldil 0x3000,r31 | |
4461 | 0x32d0 <main+216>: ble 0x3f8(sr4,r31) | |
4462 | 0x32d4 <main+220>: ldo 0(r31),rp | |
4463 | 0x32d8 <main+224>: addil -0x800,dp | |
4464 | 0x32dc <main+228>: ldo 0x588(r1),r26 | |
4465 | 0x32e0 <main+232>: ldil 0x3000,r31 | |
4466 | End of assembler dump. | |
4467 | @end smallexample | |
c906108c SS |
4468 | |
4469 | Some architectures have more than one commonly-used set of instruction | |
4470 | mnemonics or other syntax. | |
4471 | ||
4472 | @table @code | |
d4f3574e | 4473 | @kindex set disassembly-flavor |
c906108c SS |
4474 | @cindex assembly instructions |
4475 | @cindex instructions, assembly | |
4476 | @cindex machine instructions | |
4477 | @cindex listing machine instructions | |
d4f3574e SS |
4478 | @cindex Intel disassembly flavor |
4479 | @cindex AT&T disassembly flavor | |
4480 | @item set disassembly-flavor @var{instruction-set} | |
c906108c SS |
4481 | Select the instruction set to use when disassembling the |
4482 | program via the @code{disassemble} or @code{x/i} commands. | |
4483 | ||
4484 | Currently this command is only defined for the Intel x86 family. You | |
d4f3574e SS |
4485 | can set @var{instruction-set} to either @code{intel} or @code{att}. |
4486 | The default is @code{att}, the AT&T flavor used by default by Unix | |
4487 | assemblers for x86-based targets. | |
c906108c SS |
4488 | @end table |
4489 | ||
4490 | ||
6d2ebf8b | 4491 | @node Data |
c906108c SS |
4492 | @chapter Examining Data |
4493 | ||
4494 | @cindex printing data | |
4495 | @cindex examining data | |
4496 | @kindex print | |
4497 | @kindex inspect | |
4498 | @c "inspect" is not quite a synonym if you are using Epoch, which we do not | |
4499 | @c document because it is nonstandard... Under Epoch it displays in a | |
4500 | @c different window or something like that. | |
4501 | The usual way to examine data in your program is with the @code{print} | |
7a292a7a SS |
4502 | command (abbreviated @code{p}), or its synonym @code{inspect}. It |
4503 | evaluates and prints the value of an expression of the language your | |
4504 | program is written in (@pxref{Languages, ,Using @value{GDBN} with | |
4505 | Different Languages}). | |
c906108c SS |
4506 | |
4507 | @table @code | |
d4f3574e SS |
4508 | @item print @var{expr} |
4509 | @itemx print /@var{f} @var{expr} | |
4510 | @var{expr} is an expression (in the source language). By default the | |
4511 | value of @var{expr} is printed in a format appropriate to its data type; | |
c906108c | 4512 | you can choose a different format by specifying @samp{/@var{f}}, where |
d4f3574e | 4513 | @var{f} is a letter specifying the format; see @ref{Output Formats,,Output |
c906108c SS |
4514 | formats}. |
4515 | ||
4516 | @item print | |
4517 | @itemx print /@var{f} | |
d4f3574e | 4518 | If you omit @var{expr}, @value{GDBN} displays the last value again (from the |
c906108c SS |
4519 | @dfn{value history}; @pxref{Value History, ,Value history}). This allows you to |
4520 | conveniently inspect the same value in an alternative format. | |
4521 | @end table | |
4522 | ||
4523 | A more low-level way of examining data is with the @code{x} command. | |
4524 | It examines data in memory at a specified address and prints it in a | |
4525 | specified format. @xref{Memory, ,Examining memory}. | |
4526 | ||
7a292a7a | 4527 | If you are interested in information about types, or about how the |
d4f3574e SS |
4528 | fields of a struct or a class are declared, use the @code{ptype @var{exp}} |
4529 | command rather than @code{print}. @xref{Symbols, ,Examining the Symbol | |
7a292a7a | 4530 | Table}. |
c906108c SS |
4531 | |
4532 | @menu | |
4533 | * Expressions:: Expressions | |
4534 | * Variables:: Program variables | |
4535 | * Arrays:: Artificial arrays | |
4536 | * Output Formats:: Output formats | |
4537 | * Memory:: Examining memory | |
4538 | * Auto Display:: Automatic display | |
4539 | * Print Settings:: Print settings | |
4540 | * Value History:: Value history | |
4541 | * Convenience Vars:: Convenience variables | |
4542 | * Registers:: Registers | |
c906108c | 4543 | * Floating Point Hardware:: Floating point hardware |
53c69bd7 | 4544 | * Vector Unit:: Vector Unit |
29e57380 | 4545 | * Memory Region Attributes:: Memory region attributes |
16d9dec6 | 4546 | * Dump/Restore Files:: Copy between memory and a file |
a0eb71c5 KB |
4547 | * Character Sets:: Debugging programs that use a different |
4548 | character set than GDB does | |
c906108c SS |
4549 | @end menu |
4550 | ||
6d2ebf8b | 4551 | @node Expressions |
c906108c SS |
4552 | @section Expressions |
4553 | ||
4554 | @cindex expressions | |
4555 | @code{print} and many other @value{GDBN} commands accept an expression and | |
4556 | compute its value. Any kind of constant, variable or operator defined | |
4557 | by the programming language you are using is valid in an expression in | |
e2e0bcd1 JB |
4558 | @value{GDBN}. This includes conditional expressions, function calls, |
4559 | casts, and string constants. It also includes preprocessor macros, if | |
4560 | you compiled your program to include this information; see | |
4561 | @ref{Compilation}. | |
c906108c | 4562 | |
d4f3574e SS |
4563 | @value{GDBN} supports array constants in expressions input by |
4564 | the user. The syntax is @{@var{element}, @var{element}@dots{}@}. For example, | |
5d161b24 | 4565 | you can use the command @code{print @{1, 2, 3@}} to build up an array in |
d4f3574e | 4566 | memory that is @code{malloc}ed in the target program. |
c906108c | 4567 | |
c906108c SS |
4568 | Because C is so widespread, most of the expressions shown in examples in |
4569 | this manual are in C. @xref{Languages, , Using @value{GDBN} with Different | |
4570 | Languages}, for information on how to use expressions in other | |
4571 | languages. | |
4572 | ||
4573 | In this section, we discuss operators that you can use in @value{GDBN} | |
4574 | expressions regardless of your programming language. | |
4575 | ||
4576 | Casts are supported in all languages, not just in C, because it is so | |
4577 | useful to cast a number into a pointer in order to examine a structure | |
4578 | at that address in memory. | |
4579 | @c FIXME: casts supported---Mod2 true? | |
c906108c SS |
4580 | |
4581 | @value{GDBN} supports these operators, in addition to those common | |
4582 | to programming languages: | |
4583 | ||
4584 | @table @code | |
4585 | @item @@ | |
4586 | @samp{@@} is a binary operator for treating parts of memory as arrays. | |
4587 | @xref{Arrays, ,Artificial arrays}, for more information. | |
4588 | ||
4589 | @item :: | |
4590 | @samp{::} allows you to specify a variable in terms of the file or | |
4591 | function where it is defined. @xref{Variables, ,Program variables}. | |
4592 | ||
4593 | @cindex @{@var{type}@} | |
4594 | @cindex type casting memory | |
4595 | @cindex memory, viewing as typed object | |
4596 | @cindex casts, to view memory | |
4597 | @item @{@var{type}@} @var{addr} | |
4598 | Refers to an object of type @var{type} stored at address @var{addr} in | |
4599 | memory. @var{addr} may be any expression whose value is an integer or | |
4600 | pointer (but parentheses are required around binary operators, just as in | |
4601 | a cast). This construct is allowed regardless of what kind of data is | |
4602 | normally supposed to reside at @var{addr}. | |
4603 | @end table | |
4604 | ||
6d2ebf8b | 4605 | @node Variables |
c906108c SS |
4606 | @section Program variables |
4607 | ||
4608 | The most common kind of expression to use is the name of a variable | |
4609 | in your program. | |
4610 | ||
4611 | Variables in expressions are understood in the selected stack frame | |
4612 | (@pxref{Selection, ,Selecting a frame}); they must be either: | |
4613 | ||
4614 | @itemize @bullet | |
4615 | @item | |
4616 | global (or file-static) | |
4617 | @end itemize | |
4618 | ||
5d161b24 | 4619 | @noindent or |
c906108c SS |
4620 | |
4621 | @itemize @bullet | |
4622 | @item | |
4623 | visible according to the scope rules of the | |
4624 | programming language from the point of execution in that frame | |
5d161b24 | 4625 | @end itemize |
c906108c SS |
4626 | |
4627 | @noindent This means that in the function | |
4628 | ||
474c8240 | 4629 | @smallexample |
c906108c SS |
4630 | foo (a) |
4631 | int a; | |
4632 | @{ | |
4633 | bar (a); | |
4634 | @{ | |
4635 | int b = test (); | |
4636 | bar (b); | |
4637 | @} | |
4638 | @} | |
474c8240 | 4639 | @end smallexample |
c906108c SS |
4640 | |
4641 | @noindent | |
4642 | you can examine and use the variable @code{a} whenever your program is | |
4643 | executing within the function @code{foo}, but you can only use or | |
4644 | examine the variable @code{b} while your program is executing inside | |
4645 | the block where @code{b} is declared. | |
4646 | ||
4647 | @cindex variable name conflict | |
4648 | There is an exception: you can refer to a variable or function whose | |
4649 | scope is a single source file even if the current execution point is not | |
4650 | in this file. But it is possible to have more than one such variable or | |
4651 | function with the same name (in different source files). If that | |
4652 | happens, referring to that name has unpredictable effects. If you wish, | |
4653 | you can specify a static variable in a particular function or file, | |
4654 | using the colon-colon notation: | |
4655 | ||
d4f3574e | 4656 | @cindex colon-colon, context for variables/functions |
c906108c SS |
4657 | @iftex |
4658 | @c info cannot cope with a :: index entry, but why deprive hard copy readers? | |
41afff9a | 4659 | @cindex @code{::}, context for variables/functions |
c906108c | 4660 | @end iftex |
474c8240 | 4661 | @smallexample |
c906108c SS |
4662 | @var{file}::@var{variable} |
4663 | @var{function}::@var{variable} | |
474c8240 | 4664 | @end smallexample |
c906108c SS |
4665 | |
4666 | @noindent | |
4667 | Here @var{file} or @var{function} is the name of the context for the | |
4668 | static @var{variable}. In the case of file names, you can use quotes to | |
4669 | make sure @value{GDBN} parses the file name as a single word---for example, | |
4670 | to print a global value of @code{x} defined in @file{f2.c}: | |
4671 | ||
474c8240 | 4672 | @smallexample |
c906108c | 4673 | (@value{GDBP}) p 'f2.c'::x |
474c8240 | 4674 | @end smallexample |
c906108c | 4675 | |
b37052ae | 4676 | @cindex C@t{++} scope resolution |
c906108c | 4677 | This use of @samp{::} is very rarely in conflict with the very similar |
b37052ae | 4678 | use of the same notation in C@t{++}. @value{GDBN} also supports use of the C@t{++} |
c906108c SS |
4679 | scope resolution operator in @value{GDBN} expressions. |
4680 | @c FIXME: Um, so what happens in one of those rare cases where it's in | |
4681 | @c conflict?? --mew | |
c906108c SS |
4682 | |
4683 | @cindex wrong values | |
4684 | @cindex variable values, wrong | |
4685 | @quotation | |
4686 | @emph{Warning:} Occasionally, a local variable may appear to have the | |
4687 | wrong value at certain points in a function---just after entry to a new | |
4688 | scope, and just before exit. | |
4689 | @end quotation | |
4690 | You may see this problem when you are stepping by machine instructions. | |
4691 | This is because, on most machines, it takes more than one instruction to | |
4692 | set up a stack frame (including local variable definitions); if you are | |
4693 | stepping by machine instructions, variables may appear to have the wrong | |
4694 | values until the stack frame is completely built. On exit, it usually | |
4695 | also takes more than one machine instruction to destroy a stack frame; | |
4696 | after you begin stepping through that group of instructions, local | |
4697 | variable definitions may be gone. | |
4698 | ||
4699 | This may also happen when the compiler does significant optimizations. | |
4700 | To be sure of always seeing accurate values, turn off all optimization | |
4701 | when compiling. | |
4702 | ||
d4f3574e SS |
4703 | @cindex ``No symbol "foo" in current context'' |
4704 | Another possible effect of compiler optimizations is to optimize | |
4705 | unused variables out of existence, or assign variables to registers (as | |
4706 | opposed to memory addresses). Depending on the support for such cases | |
4707 | offered by the debug info format used by the compiler, @value{GDBN} | |
4708 | might not be able to display values for such local variables. If that | |
4709 | happens, @value{GDBN} will print a message like this: | |
4710 | ||
474c8240 | 4711 | @smallexample |
d4f3574e | 4712 | No symbol "foo" in current context. |
474c8240 | 4713 | @end smallexample |
d4f3574e SS |
4714 | |
4715 | To solve such problems, either recompile without optimizations, or use a | |
4716 | different debug info format, if the compiler supports several such | |
0179ffac DC |
4717 | formats. For example, @value{NGCC}, the @sc{gnu} C/C@t{++} compiler |
4718 | usually supports the @option{-gstabs+} option. @option{-gstabs+} | |
4719 | produces debug info in a format that is superior to formats such as | |
4720 | COFF. You may be able to use DWARF 2 (@option{-gdwarf-2}), which is also | |
4721 | an effective form for debug info. @xref{Debugging Options,,Options | |
4722 | for Debugging Your Program or @sc{gnu} CC, gcc.info, Using @sc{gnu} CC}. | |
d4f3574e SS |
4723 | |
4724 | ||
6d2ebf8b | 4725 | @node Arrays |
c906108c SS |
4726 | @section Artificial arrays |
4727 | ||
4728 | @cindex artificial array | |
41afff9a | 4729 | @kindex @@@r{, referencing memory as an array} |
c906108c SS |
4730 | It is often useful to print out several successive objects of the |
4731 | same type in memory; a section of an array, or an array of | |
4732 | dynamically determined size for which only a pointer exists in the | |
4733 | program. | |
4734 | ||
4735 | You can do this by referring to a contiguous span of memory as an | |
4736 | @dfn{artificial array}, using the binary operator @samp{@@}. The left | |
4737 | operand of @samp{@@} should be the first element of the desired array | |
4738 | and be an individual object. The right operand should be the desired length | |
4739 | of the array. The result is an array value whose elements are all of | |
4740 | the type of the left argument. The first element is actually the left | |
4741 | argument; the second element comes from bytes of memory immediately | |
4742 | following those that hold the first element, and so on. Here is an | |
4743 | example. If a program says | |
4744 | ||
474c8240 | 4745 | @smallexample |
c906108c | 4746 | int *array = (int *) malloc (len * sizeof (int)); |
474c8240 | 4747 | @end smallexample |
c906108c SS |
4748 | |
4749 | @noindent | |
4750 | you can print the contents of @code{array} with | |
4751 | ||
474c8240 | 4752 | @smallexample |
c906108c | 4753 | p *array@@len |
474c8240 | 4754 | @end smallexample |
c906108c SS |
4755 | |
4756 | The left operand of @samp{@@} must reside in memory. Array values made | |
4757 | with @samp{@@} in this way behave just like other arrays in terms of | |
4758 | subscripting, and are coerced to pointers when used in expressions. | |
4759 | Artificial arrays most often appear in expressions via the value history | |
4760 | (@pxref{Value History, ,Value history}), after printing one out. | |
4761 | ||
4762 | Another way to create an artificial array is to use a cast. | |
4763 | This re-interprets a value as if it were an array. | |
4764 | The value need not be in memory: | |
474c8240 | 4765 | @smallexample |
c906108c SS |
4766 | (@value{GDBP}) p/x (short[2])0x12345678 |
4767 | $1 = @{0x1234, 0x5678@} | |
474c8240 | 4768 | @end smallexample |
c906108c SS |
4769 | |
4770 | As a convenience, if you leave the array length out (as in | |
c3f6f71d | 4771 | @samp{(@var{type}[])@var{value}}) @value{GDBN} calculates the size to fill |
c906108c | 4772 | the value (as @samp{sizeof(@var{value})/sizeof(@var{type})}: |
474c8240 | 4773 | @smallexample |
c906108c SS |
4774 | (@value{GDBP}) p/x (short[])0x12345678 |
4775 | $2 = @{0x1234, 0x5678@} | |
474c8240 | 4776 | @end smallexample |
c906108c SS |
4777 | |
4778 | Sometimes the artificial array mechanism is not quite enough; in | |
4779 | moderately complex data structures, the elements of interest may not | |
4780 | actually be adjacent---for example, if you are interested in the values | |
4781 | of pointers in an array. One useful work-around in this situation is | |
4782 | to use a convenience variable (@pxref{Convenience Vars, ,Convenience | |
4783 | variables}) as a counter in an expression that prints the first | |
4784 | interesting value, and then repeat that expression via @key{RET}. For | |
4785 | instance, suppose you have an array @code{dtab} of pointers to | |
4786 | structures, and you are interested in the values of a field @code{fv} | |
4787 | in each structure. Here is an example of what you might type: | |
4788 | ||
474c8240 | 4789 | @smallexample |
c906108c SS |
4790 | set $i = 0 |
4791 | p dtab[$i++]->fv | |
4792 | @key{RET} | |
4793 | @key{RET} | |
4794 | @dots{} | |
474c8240 | 4795 | @end smallexample |
c906108c | 4796 | |
6d2ebf8b | 4797 | @node Output Formats |
c906108c SS |
4798 | @section Output formats |
4799 | ||
4800 | @cindex formatted output | |
4801 | @cindex output formats | |
4802 | By default, @value{GDBN} prints a value according to its data type. Sometimes | |
4803 | this is not what you want. For example, you might want to print a number | |
4804 | in hex, or a pointer in decimal. Or you might want to view data in memory | |
4805 | at a certain address as a character string or as an instruction. To do | |
4806 | these things, specify an @dfn{output format} when you print a value. | |
4807 | ||
4808 | The simplest use of output formats is to say how to print a value | |
4809 | already computed. This is done by starting the arguments of the | |
4810 | @code{print} command with a slash and a format letter. The format | |
4811 | letters supported are: | |
4812 | ||
4813 | @table @code | |
4814 | @item x | |
4815 | Regard the bits of the value as an integer, and print the integer in | |
4816 | hexadecimal. | |
4817 | ||
4818 | @item d | |
4819 | Print as integer in signed decimal. | |
4820 | ||
4821 | @item u | |
4822 | Print as integer in unsigned decimal. | |
4823 | ||
4824 | @item o | |
4825 | Print as integer in octal. | |
4826 | ||
4827 | @item t | |
4828 | Print as integer in binary. The letter @samp{t} stands for ``two''. | |
4829 | @footnote{@samp{b} cannot be used because these format letters are also | |
4830 | used with the @code{x} command, where @samp{b} stands for ``byte''; | |
d4f3574e | 4831 | see @ref{Memory,,Examining memory}.} |
c906108c SS |
4832 | |
4833 | @item a | |
4834 | @cindex unknown address, locating | |
3d67e040 | 4835 | @cindex locate address |
c906108c SS |
4836 | Print as an address, both absolute in hexadecimal and as an offset from |
4837 | the nearest preceding symbol. You can use this format used to discover | |
4838 | where (in what function) an unknown address is located: | |
4839 | ||
474c8240 | 4840 | @smallexample |
c906108c SS |
4841 | (@value{GDBP}) p/a 0x54320 |
4842 | $3 = 0x54320 <_initialize_vx+396> | |
474c8240 | 4843 | @end smallexample |
c906108c | 4844 | |
3d67e040 EZ |
4845 | @noindent |
4846 | The command @code{info symbol 0x54320} yields similar results. | |
4847 | @xref{Symbols, info symbol}. | |
4848 | ||
c906108c SS |
4849 | @item c |
4850 | Regard as an integer and print it as a character constant. | |
4851 | ||
4852 | @item f | |
4853 | Regard the bits of the value as a floating point number and print | |
4854 | using typical floating point syntax. | |
4855 | @end table | |
4856 | ||
4857 | For example, to print the program counter in hex (@pxref{Registers}), type | |
4858 | ||
474c8240 | 4859 | @smallexample |
c906108c | 4860 | p/x $pc |
474c8240 | 4861 | @end smallexample |
c906108c SS |
4862 | |
4863 | @noindent | |
4864 | Note that no space is required before the slash; this is because command | |
4865 | names in @value{GDBN} cannot contain a slash. | |
4866 | ||
4867 | To reprint the last value in the value history with a different format, | |
4868 | you can use the @code{print} command with just a format and no | |
4869 | expression. For example, @samp{p/x} reprints the last value in hex. | |
4870 | ||
6d2ebf8b | 4871 | @node Memory |
c906108c SS |
4872 | @section Examining memory |
4873 | ||
4874 | You can use the command @code{x} (for ``examine'') to examine memory in | |
4875 | any of several formats, independently of your program's data types. | |
4876 | ||
4877 | @cindex examining memory | |
4878 | @table @code | |
41afff9a | 4879 | @kindex x @r{(examine memory)} |
c906108c SS |
4880 | @item x/@var{nfu} @var{addr} |
4881 | @itemx x @var{addr} | |
4882 | @itemx x | |
4883 | Use the @code{x} command to examine memory. | |
4884 | @end table | |
4885 | ||
4886 | @var{n}, @var{f}, and @var{u} are all optional parameters that specify how | |
4887 | much memory to display and how to format it; @var{addr} is an | |
4888 | expression giving the address where you want to start displaying memory. | |
4889 | If you use defaults for @var{nfu}, you need not type the slash @samp{/}. | |
4890 | Several commands set convenient defaults for @var{addr}. | |
4891 | ||
4892 | @table @r | |
4893 | @item @var{n}, the repeat count | |
4894 | The repeat count is a decimal integer; the default is 1. It specifies | |
4895 | how much memory (counting by units @var{u}) to display. | |
4896 | @c This really is **decimal**; unaffected by 'set radix' as of GDB | |
4897 | @c 4.1.2. | |
4898 | ||
4899 | @item @var{f}, the display format | |
4900 | The display format is one of the formats used by @code{print}, | |
4901 | @samp{s} (null-terminated string), or @samp{i} (machine instruction). | |
4902 | The default is @samp{x} (hexadecimal) initially. | |
4903 | The default changes each time you use either @code{x} or @code{print}. | |
4904 | ||
4905 | @item @var{u}, the unit size | |
4906 | The unit size is any of | |
4907 | ||
4908 | @table @code | |
4909 | @item b | |
4910 | Bytes. | |
4911 | @item h | |
4912 | Halfwords (two bytes). | |
4913 | @item w | |
4914 | Words (four bytes). This is the initial default. | |
4915 | @item g | |
4916 | Giant words (eight bytes). | |
4917 | @end table | |
4918 | ||
4919 | Each time you specify a unit size with @code{x}, that size becomes the | |
4920 | default unit the next time you use @code{x}. (For the @samp{s} and | |
4921 | @samp{i} formats, the unit size is ignored and is normally not written.) | |
4922 | ||
4923 | @item @var{addr}, starting display address | |
4924 | @var{addr} is the address where you want @value{GDBN} to begin displaying | |
4925 | memory. The expression need not have a pointer value (though it may); | |
4926 | it is always interpreted as an integer address of a byte of memory. | |
4927 | @xref{Expressions, ,Expressions}, for more information on expressions. The default for | |
4928 | @var{addr} is usually just after the last address examined---but several | |
4929 | other commands also set the default address: @code{info breakpoints} (to | |
4930 | the address of the last breakpoint listed), @code{info line} (to the | |
4931 | starting address of a line), and @code{print} (if you use it to display | |
4932 | a value from memory). | |
4933 | @end table | |
4934 | ||
4935 | For example, @samp{x/3uh 0x54320} is a request to display three halfwords | |
4936 | (@code{h}) of memory, formatted as unsigned decimal integers (@samp{u}), | |
4937 | starting at address @code{0x54320}. @samp{x/4xw $sp} prints the four | |
4938 | words (@samp{w}) of memory above the stack pointer (here, @samp{$sp}; | |
d4f3574e | 4939 | @pxref{Registers, ,Registers}) in hexadecimal (@samp{x}). |
c906108c SS |
4940 | |
4941 | Since the letters indicating unit sizes are all distinct from the | |
4942 | letters specifying output formats, you do not have to remember whether | |
4943 | unit size or format comes first; either order works. The output | |
4944 | specifications @samp{4xw} and @samp{4wx} mean exactly the same thing. | |
4945 | (However, the count @var{n} must come first; @samp{wx4} does not work.) | |
4946 | ||
4947 | Even though the unit size @var{u} is ignored for the formats @samp{s} | |
4948 | and @samp{i}, you might still want to use a count @var{n}; for example, | |
4949 | @samp{3i} specifies that you want to see three machine instructions, | |
4950 | including any operands. The command @code{disassemble} gives an | |
d4f3574e | 4951 | alternative way of inspecting machine instructions; see @ref{Machine |
c906108c SS |
4952 | Code,,Source and machine code}. |
4953 | ||
4954 | All the defaults for the arguments to @code{x} are designed to make it | |
4955 | easy to continue scanning memory with minimal specifications each time | |
4956 | you use @code{x}. For example, after you have inspected three machine | |
4957 | instructions with @samp{x/3i @var{addr}}, you can inspect the next seven | |
4958 | with just @samp{x/7}. If you use @key{RET} to repeat the @code{x} command, | |
4959 | the repeat count @var{n} is used again; the other arguments default as | |
4960 | for successive uses of @code{x}. | |
4961 | ||
4962 | @cindex @code{$_}, @code{$__}, and value history | |
4963 | The addresses and contents printed by the @code{x} command are not saved | |
4964 | in the value history because there is often too much of them and they | |
4965 | would get in the way. Instead, @value{GDBN} makes these values available for | |
4966 | subsequent use in expressions as values of the convenience variables | |
4967 | @code{$_} and @code{$__}. After an @code{x} command, the last address | |
4968 | examined is available for use in expressions in the convenience variable | |
4969 | @code{$_}. The contents of that address, as examined, are available in | |
4970 | the convenience variable @code{$__}. | |
4971 | ||
4972 | If the @code{x} command has a repeat count, the address and contents saved | |
4973 | are from the last memory unit printed; this is not the same as the last | |
4974 | address printed if several units were printed on the last line of output. | |
4975 | ||
6d2ebf8b | 4976 | @node Auto Display |
c906108c SS |
4977 | @section Automatic display |
4978 | @cindex automatic display | |
4979 | @cindex display of expressions | |
4980 | ||
4981 | If you find that you want to print the value of an expression frequently | |
4982 | (to see how it changes), you might want to add it to the @dfn{automatic | |
4983 | display list} so that @value{GDBN} prints its value each time your program stops. | |
4984 | Each expression added to the list is given a number to identify it; | |
4985 | to remove an expression from the list, you specify that number. | |
4986 | The automatic display looks like this: | |
4987 | ||
474c8240 | 4988 | @smallexample |
c906108c SS |
4989 | 2: foo = 38 |
4990 | 3: bar[5] = (struct hack *) 0x3804 | |
474c8240 | 4991 | @end smallexample |
c906108c SS |
4992 | |
4993 | @noindent | |
4994 | This display shows item numbers, expressions and their current values. As with | |
4995 | displays you request manually using @code{x} or @code{print}, you can | |
4996 | specify the output format you prefer; in fact, @code{display} decides | |
4997 | whether to use @code{print} or @code{x} depending on how elaborate your | |
4998 | format specification is---it uses @code{x} if you specify a unit size, | |
4999 | or one of the two formats (@samp{i} and @samp{s}) that are only | |
5000 | supported by @code{x}; otherwise it uses @code{print}. | |
5001 | ||
5002 | @table @code | |
5003 | @kindex display | |
d4f3574e SS |
5004 | @item display @var{expr} |
5005 | Add the expression @var{expr} to the list of expressions to display | |
c906108c SS |
5006 | each time your program stops. @xref{Expressions, ,Expressions}. |
5007 | ||
5008 | @code{display} does not repeat if you press @key{RET} again after using it. | |
5009 | ||
d4f3574e | 5010 | @item display/@var{fmt} @var{expr} |
c906108c | 5011 | For @var{fmt} specifying only a display format and not a size or |
d4f3574e | 5012 | count, add the expression @var{expr} to the auto-display list but |
c906108c SS |
5013 | arrange to display it each time in the specified format @var{fmt}. |
5014 | @xref{Output Formats,,Output formats}. | |
5015 | ||
5016 | @item display/@var{fmt} @var{addr} | |
5017 | For @var{fmt} @samp{i} or @samp{s}, or including a unit-size or a | |
5018 | number of units, add the expression @var{addr} as a memory address to | |
5019 | be examined each time your program stops. Examining means in effect | |
5020 | doing @samp{x/@var{fmt} @var{addr}}. @xref{Memory, ,Examining memory}. | |
5021 | @end table | |
5022 | ||
5023 | For example, @samp{display/i $pc} can be helpful, to see the machine | |
5024 | instruction about to be executed each time execution stops (@samp{$pc} | |
d4f3574e | 5025 | is a common name for the program counter; @pxref{Registers, ,Registers}). |
c906108c SS |
5026 | |
5027 | @table @code | |
5028 | @kindex delete display | |
5029 | @kindex undisplay | |
5030 | @item undisplay @var{dnums}@dots{} | |
5031 | @itemx delete display @var{dnums}@dots{} | |
5032 | Remove item numbers @var{dnums} from the list of expressions to display. | |
5033 | ||
5034 | @code{undisplay} does not repeat if you press @key{RET} after using it. | |
5035 | (Otherwise you would just get the error @samp{No display number @dots{}}.) | |
5036 | ||
5037 | @kindex disable display | |
5038 | @item disable display @var{dnums}@dots{} | |
5039 | Disable the display of item numbers @var{dnums}. A disabled display | |
5040 | item is not printed automatically, but is not forgotten. It may be | |
5041 | enabled again later. | |
5042 | ||
5043 | @kindex enable display | |
5044 | @item enable display @var{dnums}@dots{} | |
5045 | Enable display of item numbers @var{dnums}. It becomes effective once | |
5046 | again in auto display of its expression, until you specify otherwise. | |
5047 | ||
5048 | @item display | |
5049 | Display the current values of the expressions on the list, just as is | |
5050 | done when your program stops. | |
5051 | ||
5052 | @kindex info display | |
5053 | @item info display | |
5054 | Print the list of expressions previously set up to display | |
5055 | automatically, each one with its item number, but without showing the | |
5056 | values. This includes disabled expressions, which are marked as such. | |
5057 | It also includes expressions which would not be displayed right now | |
5058 | because they refer to automatic variables not currently available. | |
5059 | @end table | |
5060 | ||
5061 | If a display expression refers to local variables, then it does not make | |
5062 | sense outside the lexical context for which it was set up. Such an | |
5063 | expression is disabled when execution enters a context where one of its | |
5064 | variables is not defined. For example, if you give the command | |
5065 | @code{display last_char} while inside a function with an argument | |
5066 | @code{last_char}, @value{GDBN} displays this argument while your program | |
5067 | continues to stop inside that function. When it stops elsewhere---where | |
5068 | there is no variable @code{last_char}---the display is disabled | |
5069 | automatically. The next time your program stops where @code{last_char} | |
5070 | is meaningful, you can enable the display expression once again. | |
5071 | ||
6d2ebf8b | 5072 | @node Print Settings |
c906108c SS |
5073 | @section Print settings |
5074 | ||
5075 | @cindex format options | |
5076 | @cindex print settings | |
5077 | @value{GDBN} provides the following ways to control how arrays, structures, | |
5078 | and symbols are printed. | |
5079 | ||
5080 | @noindent | |
5081 | These settings are useful for debugging programs in any language: | |
5082 | ||
5083 | @table @code | |
5084 | @kindex set print address | |
5085 | @item set print address | |
5086 | @itemx set print address on | |
5087 | @value{GDBN} prints memory addresses showing the location of stack | |
5088 | traces, structure values, pointer values, breakpoints, and so forth, | |
5089 | even when it also displays the contents of those addresses. The default | |
5090 | is @code{on}. For example, this is what a stack frame display looks like with | |
5091 | @code{set print address on}: | |
5092 | ||
5093 | @smallexample | |
5094 | @group | |
5095 | (@value{GDBP}) f | |
5096 | #0 set_quotes (lq=0x34c78 "<<", rq=0x34c88 ">>") | |
5097 | at input.c:530 | |
5098 | 530 if (lquote != def_lquote) | |
5099 | @end group | |
5100 | @end smallexample | |
5101 | ||
5102 | @item set print address off | |
5103 | Do not print addresses when displaying their contents. For example, | |
5104 | this is the same stack frame displayed with @code{set print address off}: | |
5105 | ||
5106 | @smallexample | |
5107 | @group | |
5108 | (@value{GDBP}) set print addr off | |
5109 | (@value{GDBP}) f | |
5110 | #0 set_quotes (lq="<<", rq=">>") at input.c:530 | |
5111 | 530 if (lquote != def_lquote) | |
5112 | @end group | |
5113 | @end smallexample | |
5114 | ||
5115 | You can use @samp{set print address off} to eliminate all machine | |
5116 | dependent displays from the @value{GDBN} interface. For example, with | |
5117 | @code{print address off}, you should get the same text for backtraces on | |
5118 | all machines---whether or not they involve pointer arguments. | |
5119 | ||
5120 | @kindex show print address | |
5121 | @item show print address | |
5122 | Show whether or not addresses are to be printed. | |
5123 | @end table | |
5124 | ||
5125 | When @value{GDBN} prints a symbolic address, it normally prints the | |
5126 | closest earlier symbol plus an offset. If that symbol does not uniquely | |
5127 | identify the address (for example, it is a name whose scope is a single | |
5128 | source file), you may need to clarify. One way to do this is with | |
5129 | @code{info line}, for example @samp{info line *0x4537}. Alternately, | |
5130 | you can set @value{GDBN} to print the source file and line number when | |
5131 | it prints a symbolic address: | |
5132 | ||
5133 | @table @code | |
5134 | @kindex set print symbol-filename | |
5135 | @item set print symbol-filename on | |
5136 | Tell @value{GDBN} to print the source file name and line number of a | |
5137 | symbol in the symbolic form of an address. | |
5138 | ||
5139 | @item set print symbol-filename off | |
5140 | Do not print source file name and line number of a symbol. This is the | |
5141 | default. | |
5142 | ||
5143 | @kindex show print symbol-filename | |
5144 | @item show print symbol-filename | |
5145 | Show whether or not @value{GDBN} will print the source file name and | |
5146 | line number of a symbol in the symbolic form of an address. | |
5147 | @end table | |
5148 | ||
5149 | Another situation where it is helpful to show symbol filenames and line | |
5150 | numbers is when disassembling code; @value{GDBN} shows you the line | |
5151 | number and source file that corresponds to each instruction. | |
5152 | ||
5153 | Also, you may wish to see the symbolic form only if the address being | |
5154 | printed is reasonably close to the closest earlier symbol: | |
5155 | ||
5156 | @table @code | |
5157 | @kindex set print max-symbolic-offset | |
5158 | @item set print max-symbolic-offset @var{max-offset} | |
5159 | Tell @value{GDBN} to only display the symbolic form of an address if the | |
5160 | offset between the closest earlier symbol and the address is less than | |
5d161b24 | 5161 | @var{max-offset}. The default is 0, which tells @value{GDBN} |
c906108c SS |
5162 | to always print the symbolic form of an address if any symbol precedes it. |
5163 | ||
5164 | @kindex show print max-symbolic-offset | |
5165 | @item show print max-symbolic-offset | |
5166 | Ask how large the maximum offset is that @value{GDBN} prints in a | |
5167 | symbolic address. | |
5168 | @end table | |
5169 | ||
5170 | @cindex wild pointer, interpreting | |
5171 | @cindex pointer, finding referent | |
5172 | If you have a pointer and you are not sure where it points, try | |
5173 | @samp{set print symbol-filename on}. Then you can determine the name | |
5174 | and source file location of the variable where it points, using | |
5175 | @samp{p/a @var{pointer}}. This interprets the address in symbolic form. | |
5176 | For example, here @value{GDBN} shows that a variable @code{ptt} points | |
5177 | at another variable @code{t}, defined in @file{hi2.c}: | |
5178 | ||
474c8240 | 5179 | @smallexample |
c906108c SS |
5180 | (@value{GDBP}) set print symbol-filename on |
5181 | (@value{GDBP}) p/a ptt | |
5182 | $4 = 0xe008 <t in hi2.c> | |
474c8240 | 5183 | @end smallexample |
c906108c SS |
5184 | |
5185 | @quotation | |
5186 | @emph{Warning:} For pointers that point to a local variable, @samp{p/a} | |
5187 | does not show the symbol name and filename of the referent, even with | |
5188 | the appropriate @code{set print} options turned on. | |
5189 | @end quotation | |
5190 | ||
5191 | Other settings control how different kinds of objects are printed: | |
5192 | ||
5193 | @table @code | |
5194 | @kindex set print array | |
5195 | @item set print array | |
5196 | @itemx set print array on | |
5197 | Pretty print arrays. This format is more convenient to read, | |
5198 | but uses more space. The default is off. | |
5199 | ||
5200 | @item set print array off | |
5201 | Return to compressed format for arrays. | |
5202 | ||
5203 | @kindex show print array | |
5204 | @item show print array | |
5205 | Show whether compressed or pretty format is selected for displaying | |
5206 | arrays. | |
5207 | ||
5208 | @kindex set print elements | |
5209 | @item set print elements @var{number-of-elements} | |
5210 | Set a limit on how many elements of an array @value{GDBN} will print. | |
5211 | If @value{GDBN} is printing a large array, it stops printing after it has | |
5212 | printed the number of elements set by the @code{set print elements} command. | |
5213 | This limit also applies to the display of strings. | |
d4f3574e | 5214 | When @value{GDBN} starts, this limit is set to 200. |
c906108c SS |
5215 | Setting @var{number-of-elements} to zero means that the printing is unlimited. |
5216 | ||
5217 | @kindex show print elements | |
5218 | @item show print elements | |
5219 | Display the number of elements of a large array that @value{GDBN} will print. | |
5220 | If the number is 0, then the printing is unlimited. | |
5221 | ||
5222 | @kindex set print null-stop | |
5223 | @item set print null-stop | |
5224 | Cause @value{GDBN} to stop printing the characters of an array when the first | |
d4f3574e | 5225 | @sc{null} is encountered. This is useful when large arrays actually |
c906108c | 5226 | contain only short strings. |
d4f3574e | 5227 | The default is off. |
c906108c SS |
5228 | |
5229 | @kindex set print pretty | |
5230 | @item set print pretty on | |
5d161b24 | 5231 | Cause @value{GDBN} to print structures in an indented format with one member |
c906108c SS |
5232 | per line, like this: |
5233 | ||
5234 | @smallexample | |
5235 | @group | |
5236 | $1 = @{ | |
5237 | next = 0x0, | |
5238 | flags = @{ | |
5239 | sweet = 1, | |
5240 | sour = 1 | |
5241 | @}, | |
5242 | meat = 0x54 "Pork" | |
5243 | @} | |
5244 | @end group | |
5245 | @end smallexample | |
5246 | ||
5247 | @item set print pretty off | |
5248 | Cause @value{GDBN} to print structures in a compact format, like this: | |
5249 | ||
5250 | @smallexample | |
5251 | @group | |
5252 | $1 = @{next = 0x0, flags = @{sweet = 1, sour = 1@}, \ | |
5253 | meat = 0x54 "Pork"@} | |
5254 | @end group | |
5255 | @end smallexample | |
5256 | ||
5257 | @noindent | |
5258 | This is the default format. | |
5259 | ||
5260 | @kindex show print pretty | |
5261 | @item show print pretty | |
5262 | Show which format @value{GDBN} is using to print structures. | |
5263 | ||
5264 | @kindex set print sevenbit-strings | |
5265 | @item set print sevenbit-strings on | |
5266 | Print using only seven-bit characters; if this option is set, | |
5267 | @value{GDBN} displays any eight-bit characters (in strings or | |
5268 | character values) using the notation @code{\}@var{nnn}. This setting is | |
5269 | best if you are working in English (@sc{ascii}) and you use the | |
5270 | high-order bit of characters as a marker or ``meta'' bit. | |
5271 | ||
5272 | @item set print sevenbit-strings off | |
5273 | Print full eight-bit characters. This allows the use of more | |
5274 | international character sets, and is the default. | |
5275 | ||
5276 | @kindex show print sevenbit-strings | |
5277 | @item show print sevenbit-strings | |
5278 | Show whether or not @value{GDBN} is printing only seven-bit characters. | |
5279 | ||
5280 | @kindex set print union | |
5281 | @item set print union on | |
5d161b24 | 5282 | Tell @value{GDBN} to print unions which are contained in structures. This |
c906108c SS |
5283 | is the default setting. |
5284 | ||
5285 | @item set print union off | |
5286 | Tell @value{GDBN} not to print unions which are contained in structures. | |
5287 | ||
5288 | @kindex show print union | |
5289 | @item show print union | |
5290 | Ask @value{GDBN} whether or not it will print unions which are contained in | |
5291 | structures. | |
5292 | ||
5293 | For example, given the declarations | |
5294 | ||
5295 | @smallexample | |
5296 | typedef enum @{Tree, Bug@} Species; | |
5297 | typedef enum @{Big_tree, Acorn, Seedling@} Tree_forms; | |
5d161b24 | 5298 | typedef enum @{Caterpillar, Cocoon, Butterfly@} |
c906108c SS |
5299 | Bug_forms; |
5300 | ||
5301 | struct thing @{ | |
5302 | Species it; | |
5303 | union @{ | |
5304 | Tree_forms tree; | |
5305 | Bug_forms bug; | |
5306 | @} form; | |
5307 | @}; | |
5308 | ||
5309 | struct thing foo = @{Tree, @{Acorn@}@}; | |
5310 | @end smallexample | |
5311 | ||
5312 | @noindent | |
5313 | with @code{set print union on} in effect @samp{p foo} would print | |
5314 | ||
5315 | @smallexample | |
5316 | $1 = @{it = Tree, form = @{tree = Acorn, bug = Cocoon@}@} | |
5317 | @end smallexample | |
5318 | ||
5319 | @noindent | |
5320 | and with @code{set print union off} in effect it would print | |
5321 | ||
5322 | @smallexample | |
5323 | $1 = @{it = Tree, form = @{...@}@} | |
5324 | @end smallexample | |
5325 | @end table | |
5326 | ||
c906108c SS |
5327 | @need 1000 |
5328 | @noindent | |
b37052ae | 5329 | These settings are of interest when debugging C@t{++} programs: |
c906108c SS |
5330 | |
5331 | @table @code | |
5332 | @cindex demangling | |
5333 | @kindex set print demangle | |
5334 | @item set print demangle | |
5335 | @itemx set print demangle on | |
b37052ae | 5336 | Print C@t{++} names in their source form rather than in the encoded |
c906108c | 5337 | (``mangled'') form passed to the assembler and linker for type-safe |
d4f3574e | 5338 | linkage. The default is on. |
c906108c SS |
5339 | |
5340 | @kindex show print demangle | |
5341 | @item show print demangle | |
b37052ae | 5342 | Show whether C@t{++} names are printed in mangled or demangled form. |
c906108c SS |
5343 | |
5344 | @kindex set print asm-demangle | |
5345 | @item set print asm-demangle | |
5346 | @itemx set print asm-demangle on | |
b37052ae | 5347 | Print C@t{++} names in their source form rather than their mangled form, even |
c906108c SS |
5348 | in assembler code printouts such as instruction disassemblies. |
5349 | The default is off. | |
5350 | ||
5351 | @kindex show print asm-demangle | |
5352 | @item show print asm-demangle | |
b37052ae | 5353 | Show whether C@t{++} names in assembly listings are printed in mangled |
c906108c SS |
5354 | or demangled form. |
5355 | ||
5356 | @kindex set demangle-style | |
b37052ae EZ |
5357 | @cindex C@t{++} symbol decoding style |
5358 | @cindex symbol decoding style, C@t{++} | |
c906108c SS |
5359 | @item set demangle-style @var{style} |
5360 | Choose among several encoding schemes used by different compilers to | |
b37052ae | 5361 | represent C@t{++} names. The choices for @var{style} are currently: |
c906108c SS |
5362 | |
5363 | @table @code | |
5364 | @item auto | |
5365 | Allow @value{GDBN} to choose a decoding style by inspecting your program. | |
5366 | ||
5367 | @item gnu | |
b37052ae | 5368 | Decode based on the @sc{gnu} C@t{++} compiler (@code{g++}) encoding algorithm. |
c906108c | 5369 | This is the default. |
c906108c SS |
5370 | |
5371 | @item hp | |
b37052ae | 5372 | Decode based on the HP ANSI C@t{++} (@code{aCC}) encoding algorithm. |
c906108c SS |
5373 | |
5374 | @item lucid | |
b37052ae | 5375 | Decode based on the Lucid C@t{++} compiler (@code{lcc}) encoding algorithm. |
c906108c SS |
5376 | |
5377 | @item arm | |
b37052ae | 5378 | Decode using the algorithm in the @cite{C@t{++} Annotated Reference Manual}. |
c906108c SS |
5379 | @strong{Warning:} this setting alone is not sufficient to allow |
5380 | debugging @code{cfront}-generated executables. @value{GDBN} would | |
5381 | require further enhancement to permit that. | |
5382 | ||
5383 | @end table | |
5384 | If you omit @var{style}, you will see a list of possible formats. | |
5385 | ||
5386 | @kindex show demangle-style | |
5387 | @item show demangle-style | |
b37052ae | 5388 | Display the encoding style currently in use for decoding C@t{++} symbols. |
c906108c SS |
5389 | |
5390 | @kindex set print object | |
5391 | @item set print object | |
5392 | @itemx set print object on | |
5393 | When displaying a pointer to an object, identify the @emph{actual} | |
5394 | (derived) type of the object rather than the @emph{declared} type, using | |
5395 | the virtual function table. | |
5396 | ||
5397 | @item set print object off | |
5398 | Display only the declared type of objects, without reference to the | |
5399 | virtual function table. This is the default setting. | |
5400 | ||
5401 | @kindex show print object | |
5402 | @item show print object | |
5403 | Show whether actual, or declared, object types are displayed. | |
5404 | ||
5405 | @kindex set print static-members | |
5406 | @item set print static-members | |
5407 | @itemx set print static-members on | |
b37052ae | 5408 | Print static members when displaying a C@t{++} object. The default is on. |
c906108c SS |
5409 | |
5410 | @item set print static-members off | |
b37052ae | 5411 | Do not print static members when displaying a C@t{++} object. |
c906108c SS |
5412 | |
5413 | @kindex show print static-members | |
5414 | @item show print static-members | |
b37052ae | 5415 | Show whether C@t{++} static members are printed, or not. |
c906108c SS |
5416 | |
5417 | @c These don't work with HP ANSI C++ yet. | |
5418 | @kindex set print vtbl | |
5419 | @item set print vtbl | |
5420 | @itemx set print vtbl on | |
b37052ae | 5421 | Pretty print C@t{++} virtual function tables. The default is off. |
c906108c | 5422 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 5423 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
5424 | |
5425 | @item set print vtbl off | |
b37052ae | 5426 | Do not pretty print C@t{++} virtual function tables. |
c906108c SS |
5427 | |
5428 | @kindex show print vtbl | |
5429 | @item show print vtbl | |
b37052ae | 5430 | Show whether C@t{++} virtual function tables are pretty printed, or not. |
c906108c | 5431 | @end table |
c906108c | 5432 | |
6d2ebf8b | 5433 | @node Value History |
c906108c SS |
5434 | @section Value history |
5435 | ||
5436 | @cindex value history | |
5d161b24 DB |
5437 | Values printed by the @code{print} command are saved in the @value{GDBN} |
5438 | @dfn{value history}. This allows you to refer to them in other expressions. | |
5439 | Values are kept until the symbol table is re-read or discarded | |
5440 | (for example with the @code{file} or @code{symbol-file} commands). | |
5441 | When the symbol table changes, the value history is discarded, | |
5442 | since the values may contain pointers back to the types defined in the | |
c906108c SS |
5443 | symbol table. |
5444 | ||
5445 | @cindex @code{$} | |
5446 | @cindex @code{$$} | |
5447 | @cindex history number | |
5448 | The values printed are given @dfn{history numbers} by which you can | |
5449 | refer to them. These are successive integers starting with one. | |
5450 | @code{print} shows you the history number assigned to a value by | |
5451 | printing @samp{$@var{num} = } before the value; here @var{num} is the | |
5452 | history number. | |
5453 | ||
5454 | To refer to any previous value, use @samp{$} followed by the value's | |
5455 | history number. The way @code{print} labels its output is designed to | |
5456 | remind you of this. Just @code{$} refers to the most recent value in | |
5457 | the history, and @code{$$} refers to the value before that. | |
5458 | @code{$$@var{n}} refers to the @var{n}th value from the end; @code{$$2} | |
5459 | is the value just prior to @code{$$}, @code{$$1} is equivalent to | |
5460 | @code{$$}, and @code{$$0} is equivalent to @code{$}. | |
5461 | ||
5462 | For example, suppose you have just printed a pointer to a structure and | |
5463 | want to see the contents of the structure. It suffices to type | |
5464 | ||
474c8240 | 5465 | @smallexample |
c906108c | 5466 | p *$ |
474c8240 | 5467 | @end smallexample |
c906108c SS |
5468 | |
5469 | If you have a chain of structures where the component @code{next} points | |
5470 | to the next one, you can print the contents of the next one with this: | |
5471 | ||
474c8240 | 5472 | @smallexample |
c906108c | 5473 | p *$.next |
474c8240 | 5474 | @end smallexample |
c906108c SS |
5475 | |
5476 | @noindent | |
5477 | You can print successive links in the chain by repeating this | |
5478 | command---which you can do by just typing @key{RET}. | |
5479 | ||
5480 | Note that the history records values, not expressions. If the value of | |
5481 | @code{x} is 4 and you type these commands: | |
5482 | ||
474c8240 | 5483 | @smallexample |
c906108c SS |
5484 | print x |
5485 | set x=5 | |
474c8240 | 5486 | @end smallexample |
c906108c SS |
5487 | |
5488 | @noindent | |
5489 | then the value recorded in the value history by the @code{print} command | |
5490 | remains 4 even though the value of @code{x} has changed. | |
5491 | ||
5492 | @table @code | |
5493 | @kindex show values | |
5494 | @item show values | |
5495 | Print the last ten values in the value history, with their item numbers. | |
5496 | This is like @samp{p@ $$9} repeated ten times, except that @code{show | |
5497 | values} does not change the history. | |
5498 | ||
5499 | @item show values @var{n} | |
5500 | Print ten history values centered on history item number @var{n}. | |
5501 | ||
5502 | @item show values + | |
5503 | Print ten history values just after the values last printed. If no more | |
5504 | values are available, @code{show values +} produces no display. | |
5505 | @end table | |
5506 | ||
5507 | Pressing @key{RET} to repeat @code{show values @var{n}} has exactly the | |
5508 | same effect as @samp{show values +}. | |
5509 | ||
6d2ebf8b | 5510 | @node Convenience Vars |
c906108c SS |
5511 | @section Convenience variables |
5512 | ||
5513 | @cindex convenience variables | |
5514 | @value{GDBN} provides @dfn{convenience variables} that you can use within | |
5515 | @value{GDBN} to hold on to a value and refer to it later. These variables | |
5516 | exist entirely within @value{GDBN}; they are not part of your program, and | |
5517 | setting a convenience variable has no direct effect on further execution | |
5518 | of your program. That is why you can use them freely. | |
5519 | ||
5520 | Convenience variables are prefixed with @samp{$}. Any name preceded by | |
5521 | @samp{$} can be used for a convenience variable, unless it is one of | |
d4f3574e | 5522 | the predefined machine-specific register names (@pxref{Registers, ,Registers}). |
c906108c SS |
5523 | (Value history references, in contrast, are @emph{numbers} preceded |
5524 | by @samp{$}. @xref{Value History, ,Value history}.) | |
5525 | ||
5526 | You can save a value in a convenience variable with an assignment | |
5527 | expression, just as you would set a variable in your program. | |
5528 | For example: | |
5529 | ||
474c8240 | 5530 | @smallexample |
c906108c | 5531 | set $foo = *object_ptr |
474c8240 | 5532 | @end smallexample |
c906108c SS |
5533 | |
5534 | @noindent | |
5535 | would save in @code{$foo} the value contained in the object pointed to by | |
5536 | @code{object_ptr}. | |
5537 | ||
5538 | Using a convenience variable for the first time creates it, but its | |
5539 | value is @code{void} until you assign a new value. You can alter the | |
5540 | value with another assignment at any time. | |
5541 | ||
5542 | Convenience variables have no fixed types. You can assign a convenience | |
5543 | variable any type of value, including structures and arrays, even if | |
5544 | that variable already has a value of a different type. The convenience | |
5545 | variable, when used as an expression, has the type of its current value. | |
5546 | ||
5547 | @table @code | |
5548 | @kindex show convenience | |
5549 | @item show convenience | |
5550 | Print a list of convenience variables used so far, and their values. | |
d4f3574e | 5551 | Abbreviated @code{show conv}. |
c906108c SS |
5552 | @end table |
5553 | ||
5554 | One of the ways to use a convenience variable is as a counter to be | |
5555 | incremented or a pointer to be advanced. For example, to print | |
5556 | a field from successive elements of an array of structures: | |
5557 | ||
474c8240 | 5558 | @smallexample |
c906108c SS |
5559 | set $i = 0 |
5560 | print bar[$i++]->contents | |
474c8240 | 5561 | @end smallexample |
c906108c | 5562 | |
d4f3574e SS |
5563 | @noindent |
5564 | Repeat that command by typing @key{RET}. | |
c906108c SS |
5565 | |
5566 | Some convenience variables are created automatically by @value{GDBN} and given | |
5567 | values likely to be useful. | |
5568 | ||
5569 | @table @code | |
41afff9a | 5570 | @vindex $_@r{, convenience variable} |
c906108c SS |
5571 | @item $_ |
5572 | The variable @code{$_} is automatically set by the @code{x} command to | |
5573 | the last address examined (@pxref{Memory, ,Examining memory}). Other | |
5574 | commands which provide a default address for @code{x} to examine also | |
5575 | set @code{$_} to that address; these commands include @code{info line} | |
5576 | and @code{info breakpoint}. The type of @code{$_} is @code{void *} | |
5577 | except when set by the @code{x} command, in which case it is a pointer | |
5578 | to the type of @code{$__}. | |
5579 | ||
41afff9a | 5580 | @vindex $__@r{, convenience variable} |
c906108c SS |
5581 | @item $__ |
5582 | The variable @code{$__} is automatically set by the @code{x} command | |
5583 | to the value found in the last address examined. Its type is chosen | |
5584 | to match the format in which the data was printed. | |
5585 | ||
5586 | @item $_exitcode | |
41afff9a | 5587 | @vindex $_exitcode@r{, convenience variable} |
c906108c SS |
5588 | The variable @code{$_exitcode} is automatically set to the exit code when |
5589 | the program being debugged terminates. | |
5590 | @end table | |
5591 | ||
53a5351d JM |
5592 | On HP-UX systems, if you refer to a function or variable name that |
5593 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
5594 | name first, before it searches for a convenience variable. | |
c906108c | 5595 | |
6d2ebf8b | 5596 | @node Registers |
c906108c SS |
5597 | @section Registers |
5598 | ||
5599 | @cindex registers | |
5600 | You can refer to machine register contents, in expressions, as variables | |
5601 | with names starting with @samp{$}. The names of registers are different | |
5602 | for each machine; use @code{info registers} to see the names used on | |
5603 | your machine. | |
5604 | ||
5605 | @table @code | |
5606 | @kindex info registers | |
5607 | @item info registers | |
5608 | Print the names and values of all registers except floating-point | |
c85508ee | 5609 | and vector registers (in the selected stack frame). |
c906108c SS |
5610 | |
5611 | @kindex info all-registers | |
5612 | @cindex floating point registers | |
5613 | @item info all-registers | |
5614 | Print the names and values of all registers, including floating-point | |
c85508ee | 5615 | and vector registers (in the selected stack frame). |
c906108c SS |
5616 | |
5617 | @item info registers @var{regname} @dots{} | |
5618 | Print the @dfn{relativized} value of each specified register @var{regname}. | |
5d161b24 DB |
5619 | As discussed in detail below, register values are normally relative to |
5620 | the selected stack frame. @var{regname} may be any register name valid on | |
c906108c SS |
5621 | the machine you are using, with or without the initial @samp{$}. |
5622 | @end table | |
5623 | ||
5624 | @value{GDBN} has four ``standard'' register names that are available (in | |
5625 | expressions) on most machines---whenever they do not conflict with an | |
5626 | architecture's canonical mnemonics for registers. The register names | |
5627 | @code{$pc} and @code{$sp} are used for the program counter register and | |
5628 | the stack pointer. @code{$fp} is used for a register that contains a | |
5629 | pointer to the current stack frame, and @code{$ps} is used for a | |
5630 | register that contains the processor status. For example, | |
5631 | you could print the program counter in hex with | |
5632 | ||
474c8240 | 5633 | @smallexample |
c906108c | 5634 | p/x $pc |
474c8240 | 5635 | @end smallexample |
c906108c SS |
5636 | |
5637 | @noindent | |
5638 | or print the instruction to be executed next with | |
5639 | ||
474c8240 | 5640 | @smallexample |
c906108c | 5641 | x/i $pc |
474c8240 | 5642 | @end smallexample |
c906108c SS |
5643 | |
5644 | @noindent | |
5645 | or add four to the stack pointer@footnote{This is a way of removing | |
5646 | one word from the stack, on machines where stacks grow downward in | |
5647 | memory (most machines, nowadays). This assumes that the innermost | |
5648 | stack frame is selected; setting @code{$sp} is not allowed when other | |
5649 | stack frames are selected. To pop entire frames off the stack, | |
5650 | regardless of machine architecture, use @code{return}; | |
d4f3574e | 5651 | see @ref{Returning, ,Returning from a function}.} with |
c906108c | 5652 | |
474c8240 | 5653 | @smallexample |
c906108c | 5654 | set $sp += 4 |
474c8240 | 5655 | @end smallexample |
c906108c SS |
5656 | |
5657 | Whenever possible, these four standard register names are available on | |
5658 | your machine even though the machine has different canonical mnemonics, | |
5659 | so long as there is no conflict. The @code{info registers} command | |
5660 | shows the canonical names. For example, on the SPARC, @code{info | |
5661 | registers} displays the processor status register as @code{$psr} but you | |
d4f3574e SS |
5662 | can also refer to it as @code{$ps}; and on x86-based machines @code{$ps} |
5663 | is an alias for the @sc{eflags} register. | |
c906108c SS |
5664 | |
5665 | @value{GDBN} always considers the contents of an ordinary register as an | |
5666 | integer when the register is examined in this way. Some machines have | |
5667 | special registers which can hold nothing but floating point; these | |
5668 | registers are considered to have floating point values. There is no way | |
5669 | to refer to the contents of an ordinary register as floating point value | |
5670 | (although you can @emph{print} it as a floating point value with | |
5671 | @samp{print/f $@var{regname}}). | |
5672 | ||
5673 | Some registers have distinct ``raw'' and ``virtual'' data formats. This | |
5674 | means that the data format in which the register contents are saved by | |
5675 | the operating system is not the same one that your program normally | |
5676 | sees. For example, the registers of the 68881 floating point | |
5677 | coprocessor are always saved in ``extended'' (raw) format, but all C | |
5678 | programs expect to work with ``double'' (virtual) format. In such | |
5d161b24 | 5679 | cases, @value{GDBN} normally works with the virtual format only (the format |
c906108c SS |
5680 | that makes sense for your program), but the @code{info registers} command |
5681 | prints the data in both formats. | |
5682 | ||
5683 | Normally, register values are relative to the selected stack frame | |
5684 | (@pxref{Selection, ,Selecting a frame}). This means that you get the | |
5685 | value that the register would contain if all stack frames farther in | |
5686 | were exited and their saved registers restored. In order to see the | |
5687 | true contents of hardware registers, you must select the innermost | |
5688 | frame (with @samp{frame 0}). | |
5689 | ||
5690 | However, @value{GDBN} must deduce where registers are saved, from the machine | |
5691 | code generated by your compiler. If some registers are not saved, or if | |
5692 | @value{GDBN} is unable to locate the saved registers, the selected stack | |
5693 | frame makes no difference. | |
5694 | ||
6d2ebf8b | 5695 | @node Floating Point Hardware |
c906108c SS |
5696 | @section Floating point hardware |
5697 | @cindex floating point | |
5698 | ||
5699 | Depending on the configuration, @value{GDBN} may be able to give | |
5700 | you more information about the status of the floating point hardware. | |
5701 | ||
5702 | @table @code | |
5703 | @kindex info float | |
5704 | @item info float | |
5705 | Display hardware-dependent information about the floating | |
5706 | point unit. The exact contents and layout vary depending on the | |
5707 | floating point chip. Currently, @samp{info float} is supported on | |
5708 | the ARM and x86 machines. | |
5709 | @end table | |
c906108c | 5710 | |
e76f1f2e AC |
5711 | @node Vector Unit |
5712 | @section Vector Unit | |
5713 | @cindex vector unit | |
5714 | ||
5715 | Depending on the configuration, @value{GDBN} may be able to give you | |
5716 | more information about the status of the vector unit. | |
5717 | ||
5718 | @table @code | |
5719 | @kindex info vector | |
5720 | @item info vector | |
5721 | Display information about the vector unit. The exact contents and | |
5722 | layout vary depending on the hardware. | |
5723 | @end table | |
5724 | ||
29e57380 | 5725 | @node Memory Region Attributes |
16d9dec6 | 5726 | @section Memory region attributes |
29e57380 C |
5727 | @cindex memory region attributes |
5728 | ||
5729 | @dfn{Memory region attributes} allow you to describe special handling | |
5730 | required by regions of your target's memory. @value{GDBN} uses attributes | |
5731 | to determine whether to allow certain types of memory accesses; whether to | |
5732 | use specific width accesses; and whether to cache target memory. | |
5733 | ||
5734 | Defined memory regions can be individually enabled and disabled. When a | |
5735 | memory region is disabled, @value{GDBN} uses the default attributes when | |
5736 | accessing memory in that region. Similarly, if no memory regions have | |
5737 | been defined, @value{GDBN} uses the default attributes when accessing | |
5738 | all memory. | |
5739 | ||
5740 | When a memory region is defined, it is given a number to identify it; | |
5741 | to enable, disable, or remove a memory region, you specify that number. | |
5742 | ||
5743 | @table @code | |
5744 | @kindex mem | |
bfac230e DH |
5745 | @item mem @var{lower} @var{upper} @var{attributes}@dots{} |
5746 | Define memory region bounded by @var{lower} and @var{upper} with | |
5747 | attributes @var{attributes}@dots{}. Note that @var{upper} == 0 is a | |
5748 | special case: it is treated as the the target's maximum memory address. | |
5749 | (0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.) | |
29e57380 C |
5750 | |
5751 | @kindex delete mem | |
5752 | @item delete mem @var{nums}@dots{} | |
59649f2e | 5753 | Remove memory regions @var{nums}@dots{}. |
29e57380 C |
5754 | |
5755 | @kindex disable mem | |
5756 | @item disable mem @var{nums}@dots{} | |
59649f2e | 5757 | Disable memory regions @var{nums}@dots{}. |
29e57380 C |
5758 | A disabled memory region is not forgotten. |
5759 | It may be enabled again later. | |
5760 | ||
5761 | @kindex enable mem | |
5762 | @item enable mem @var{nums}@dots{} | |
59649f2e | 5763 | Enable memory regions @var{nums}@dots{}. |
29e57380 C |
5764 | |
5765 | @kindex info mem | |
5766 | @item info mem | |
5767 | Print a table of all defined memory regions, with the following columns | |
5768 | for each region. | |
5769 | ||
5770 | @table @emph | |
5771 | @item Memory Region Number | |
5772 | @item Enabled or Disabled. | |
5773 | Enabled memory regions are marked with @samp{y}. | |
5774 | Disabled memory regions are marked with @samp{n}. | |
5775 | ||
5776 | @item Lo Address | |
5777 | The address defining the inclusive lower bound of the memory region. | |
5778 | ||
5779 | @item Hi Address | |
5780 | The address defining the exclusive upper bound of the memory region. | |
5781 | ||
5782 | @item Attributes | |
5783 | The list of attributes set for this memory region. | |
5784 | @end table | |
5785 | @end table | |
5786 | ||
5787 | ||
5788 | @subsection Attributes | |
5789 | ||
5790 | @subsubsection Memory Access Mode | |
5791 | The access mode attributes set whether @value{GDBN} may make read or | |
5792 | write accesses to a memory region. | |
5793 | ||
5794 | While these attributes prevent @value{GDBN} from performing invalid | |
5795 | memory accesses, they do nothing to prevent the target system, I/O DMA, | |
5796 | etc. from accessing memory. | |
5797 | ||
5798 | @table @code | |
5799 | @item ro | |
5800 | Memory is read only. | |
5801 | @item wo | |
5802 | Memory is write only. | |
5803 | @item rw | |
6ca652b0 | 5804 | Memory is read/write. This is the default. |
29e57380 C |
5805 | @end table |
5806 | ||
5807 | @subsubsection Memory Access Size | |
5808 | The acccess size attributes tells @value{GDBN} to use specific sized | |
5809 | accesses in the memory region. Often memory mapped device registers | |
5810 | require specific sized accesses. If no access size attribute is | |
5811 | specified, @value{GDBN} may use accesses of any size. | |
5812 | ||
5813 | @table @code | |
5814 | @item 8 | |
5815 | Use 8 bit memory accesses. | |
5816 | @item 16 | |
5817 | Use 16 bit memory accesses. | |
5818 | @item 32 | |
5819 | Use 32 bit memory accesses. | |
5820 | @item 64 | |
5821 | Use 64 bit memory accesses. | |
5822 | @end table | |
5823 | ||
5824 | @c @subsubsection Hardware/Software Breakpoints | |
5825 | @c The hardware/software breakpoint attributes set whether @value{GDBN} | |
5826 | @c will use hardware or software breakpoints for the internal breakpoints | |
5827 | @c used by the step, next, finish, until, etc. commands. | |
5828 | @c | |
5829 | @c @table @code | |
5830 | @c @item hwbreak | |
5831 | @c Always use hardware breakpoints | |
5832 | @c @item swbreak (default) | |
5833 | @c @end table | |
5834 | ||
5835 | @subsubsection Data Cache | |
5836 | The data cache attributes set whether @value{GDBN} will cache target | |
5837 | memory. While this generally improves performance by reducing debug | |
5838 | protocol overhead, it can lead to incorrect results because @value{GDBN} | |
5839 | does not know about volatile variables or memory mapped device | |
5840 | registers. | |
5841 | ||
5842 | @table @code | |
5843 | @item cache | |
5844 | Enable @value{GDBN} to cache target memory. | |
6ca652b0 EZ |
5845 | @item nocache |
5846 | Disable @value{GDBN} from caching target memory. This is the default. | |
29e57380 C |
5847 | @end table |
5848 | ||
5849 | @c @subsubsection Memory Write Verification | |
5850 | @c The memory write verification attributes set whether @value{GDBN} | |
5851 | @c will re-reads data after each write to verify the write was successful. | |
5852 | @c | |
5853 | @c @table @code | |
5854 | @c @item verify | |
5855 | @c @item noverify (default) | |
5856 | @c @end table | |
5857 | ||
16d9dec6 MS |
5858 | @node Dump/Restore Files |
5859 | @section Copy between memory and a file | |
5860 | @cindex dump/restore files | |
5861 | @cindex append data to a file | |
5862 | @cindex dump data to a file | |
5863 | @cindex restore data from a file | |
5864 | @kindex dump | |
5865 | @kindex append | |
5866 | @kindex restore | |
5867 | ||
5868 | The commands @code{dump}, @code{append}, and @code{restore} are used | |
5869 | for copying data between target memory and a file. Data is written | |
5870 | into a file using @code{dump} or @code{append}, and restored from a | |
5871 | file into memory by using @code{restore}. Files may be binary, srec, | |
5872 | intel hex, or tekhex (but only binary files can be appended). | |
5873 | ||
5874 | @table @code | |
5875 | @kindex dump binary | |
5876 | @kindex append binary | |
5877 | @item dump binary memory @var{filename} @var{start_addr} @var{end_addr} | |
5878 | Dump contents of memory from @var{start_addr} to @var{end_addr} into | |
5879 | raw binary format file @var{filename}. | |
5880 | ||
5881 | @item append binary memory @var{filename} @var{start_addr} @var{end_addr} | |
5882 | Append contents of memory from @var{start_addr} to @var{end_addr} to | |
5883 | raw binary format file @var{filename}. | |
5884 | ||
5885 | @item dump binary value @var{filename} @var{expression} | |
5886 | Dump value of @var{expression} into raw binary format file @var{filename}. | |
5887 | ||
5888 | @item append binary memory @var{filename} @var{expression} | |
5889 | Append value of @var{expression} to raw binary format file @var{filename}. | |
5890 | ||
5891 | @kindex dump ihex | |
5892 | @item dump ihex memory @var{filename} @var{start_addr} @var{end_addr} | |
5893 | Dump contents of memory from @var{start_addr} to @var{end_addr} into | |
5894 | intel hex format file @var{filename}. | |
5895 | ||
5896 | @item dump ihex value @var{filename} @var{expression} | |
5897 | Dump value of @var{expression} into intel hex format file @var{filename}. | |
5898 | ||
5899 | @kindex dump srec | |
5900 | @item dump srec memory @var{filename} @var{start_addr} @var{end_addr} | |
5901 | Dump contents of memory from @var{start_addr} to @var{end_addr} into | |
5902 | srec format file @var{filename}. | |
5903 | ||
5904 | @item dump srec value @var{filename} @var{expression} | |
5905 | Dump value of @var{expression} into srec format file @var{filename}. | |
5906 | ||
5907 | @kindex dump tekhex | |
5908 | @item dump tekhex memory @var{filename} @var{start_addr} @var{end_addr} | |
5909 | Dump contents of memory from @var{start_addr} to @var{end_addr} into | |
5910 | tekhex format file @var{filename}. | |
5911 | ||
5912 | @item dump tekhex value @var{filename} @var{expression} | |
5913 | Dump value of @var{expression} into tekhex format file @var{filename}. | |
5914 | ||
42f9b0a5 | 5915 | @item restore @var{filename} [@var{binary}] @var{bias} @var{start} @var{end} |
16d9dec6 MS |
5916 | Restore the contents of file @var{filename} into memory. The @code{restore} |
5917 | command can automatically recognize any known bfd file format, except for | |
5918 | raw binary. To restore a raw binary file you must use the optional argument | |
5919 | @var{binary} after the filename. | |
5920 | ||
5921 | If @var{bias} is non-zero, its value will be added to the addresses | |
5922 | contained in the file. Binary files always start at address zero, so | |
5923 | they will be restored at address @var{bias}. Other bfd files have | |
5924 | a built-in location; they will be restored at offset @var{bias} | |
5925 | from that location. | |
5926 | ||
5927 | If @var{start} and/or @var{end} are non-zero, then only data between | |
5928 | file offset @var{start} and file offset @var{end} will be restored. | |
5929 | These offsets are relative to the addresses in the file, before | |
5930 | the @var{bias} argument is applied. | |
5931 | ||
5932 | @end table | |
5933 | ||
a0eb71c5 KB |
5934 | @node Character Sets |
5935 | @section Character Sets | |
5936 | @cindex character sets | |
5937 | @cindex charset | |
5938 | @cindex translating between character sets | |
5939 | @cindex host character set | |
5940 | @cindex target character set | |
5941 | ||
5942 | If the program you are debugging uses a different character set to | |
5943 | represent characters and strings than the one @value{GDBN} uses itself, | |
5944 | @value{GDBN} can automatically translate between the character sets for | |
5945 | you. The character set @value{GDBN} uses we call the @dfn{host | |
5946 | character set}; the one the inferior program uses we call the | |
5947 | @dfn{target character set}. | |
5948 | ||
5949 | For example, if you are running @value{GDBN} on a @sc{gnu}/Linux system, which | |
5950 | uses the ISO Latin 1 character set, but you are using @value{GDBN}'s | |
5951 | remote protocol (@pxref{Remote,Remote Debugging}) to debug a program | |
5952 | running on an IBM mainframe, which uses the @sc{ebcdic} character set, | |
5953 | then the host character set is Latin-1, and the target character set is | |
5954 | @sc{ebcdic}. If you give @value{GDBN} the command @code{set | |
5955 | target-charset ebcdic-us}, then @value{GDBN} translates between | |
5956 | @sc{ebcdic} and Latin 1 as you print character or string values, or use | |
5957 | character and string literals in expressions. | |
5958 | ||
5959 | @value{GDBN} has no way to automatically recognize which character set | |
5960 | the inferior program uses; you must tell it, using the @code{set | |
5961 | target-charset} command, described below. | |
5962 | ||
5963 | Here are the commands for controlling @value{GDBN}'s character set | |
5964 | support: | |
5965 | ||
5966 | @table @code | |
5967 | @item set target-charset @var{charset} | |
5968 | @kindex set target-charset | |
5969 | Set the current target character set to @var{charset}. We list the | |
5970 | character set names @value{GDBN} recognizes below, but if you invoke the | |
5971 | @code{set target-charset} command with no argument, @value{GDBN} lists | |
5972 | the character sets it supports. | |
5973 | @end table | |
5974 | ||
5975 | @table @code | |
5976 | @item set host-charset @var{charset} | |
5977 | @kindex set host-charset | |
5978 | Set the current host character set to @var{charset}. | |
5979 | ||
5980 | By default, @value{GDBN} uses a host character set appropriate to the | |
5981 | system it is running on; you can override that default using the | |
5982 | @code{set host-charset} command. | |
5983 | ||
5984 | @value{GDBN} can only use certain character sets as its host character | |
5985 | set. We list the character set names @value{GDBN} recognizes below, and | |
5986 | indicate which can be host character sets, but if you invoke the | |
5987 | @code{set host-charset} command with no argument, @value{GDBN} lists the | |
5988 | character sets it supports, placing an asterisk (@samp{*}) after those | |
5989 | it can use as a host character set. | |
5990 | ||
5991 | @item set charset @var{charset} | |
5992 | @kindex set charset | |
5993 | Set the current host and target character sets to @var{charset}. If you | |
5994 | invoke the @code{set charset} command with no argument, it lists the | |
5995 | character sets it supports. @value{GDBN} can only use certain character | |
5996 | sets as its host character set; it marks those in the list with an | |
5997 | asterisk (@samp{*}). | |
5998 | ||
5999 | @item show charset | |
6000 | @itemx show host-charset | |
6001 | @itemx show target-charset | |
6002 | @kindex show charset | |
6003 | @kindex show host-charset | |
6004 | @kindex show target-charset | |
6005 | Show the current host and target charsets. The @code{show host-charset} | |
6006 | and @code{show target-charset} commands are synonyms for @code{show | |
6007 | charset}. | |
6008 | ||
6009 | @end table | |
6010 | ||
6011 | @value{GDBN} currently includes support for the following character | |
6012 | sets: | |
6013 | ||
6014 | @table @code | |
6015 | ||
6016 | @item ASCII | |
6017 | @cindex ASCII character set | |
6018 | Seven-bit U.S. @sc{ascii}. @value{GDBN} can use this as its host | |
6019 | character set. | |
6020 | ||
6021 | @item ISO-8859-1 | |
6022 | @cindex ISO 8859-1 character set | |
6023 | @cindex ISO Latin 1 character set | |
6024 | The ISO Latin 1 character set. This extends ASCII with accented | |
6025 | characters needed for French, German, and Spanish. @value{GDBN} can use | |
6026 | this as its host character set. | |
6027 | ||
6028 | @item EBCDIC-US | |
6029 | @itemx IBM1047 | |
6030 | @cindex EBCDIC character set | |
6031 | @cindex IBM1047 character set | |
6032 | Variants of the @sc{ebcdic} character set, used on some of IBM's | |
6033 | mainframe operating systems. (@sc{gnu}/Linux on the S/390 uses U.S. @sc{ascii}.) | |
6034 | @value{GDBN} cannot use these as its host character set. | |
6035 | ||
6036 | @end table | |
6037 | ||
6038 | Note that these are all single-byte character sets. More work inside | |
6039 | GDB is needed to support multi-byte or variable-width character | |
6040 | encodings, like the UTF-8 and UCS-2 encodings of Unicode. | |
6041 | ||
6042 | Here is an example of @value{GDBN}'s character set support in action. | |
6043 | Assume that the following source code has been placed in the file | |
6044 | @file{charset-test.c}: | |
6045 | ||
6046 | @smallexample | |
6047 | #include <stdio.h> | |
6048 | ||
6049 | char ascii_hello[] | |
6050 | = @{72, 101, 108, 108, 111, 44, 32, 119, | |
6051 | 111, 114, 108, 100, 33, 10, 0@}; | |
6052 | char ibm1047_hello[] | |
6053 | = @{200, 133, 147, 147, 150, 107, 64, 166, | |
6054 | 150, 153, 147, 132, 90, 37, 0@}; | |
6055 | ||
6056 | main () | |
6057 | @{ | |
6058 | printf ("Hello, world!\n"); | |
6059 | @} | |
10998722 | 6060 | @end smallexample |
a0eb71c5 KB |
6061 | |
6062 | In this program, @code{ascii_hello} and @code{ibm1047_hello} are arrays | |
6063 | containing the string @samp{Hello, world!} followed by a newline, | |
6064 | encoded in the @sc{ascii} and @sc{ibm1047} character sets. | |
6065 | ||
6066 | We compile the program, and invoke the debugger on it: | |
6067 | ||
6068 | @smallexample | |
6069 | $ gcc -g charset-test.c -o charset-test | |
6070 | $ gdb -nw charset-test | |
6071 | GNU gdb 2001-12-19-cvs | |
6072 | Copyright 2001 Free Software Foundation, Inc. | |
6073 | @dots{} | |
6074 | (gdb) | |
10998722 | 6075 | @end smallexample |
a0eb71c5 KB |
6076 | |
6077 | We can use the @code{show charset} command to see what character sets | |
6078 | @value{GDBN} is currently using to interpret and display characters and | |
6079 | strings: | |
6080 | ||
6081 | @smallexample | |
6082 | (gdb) show charset | |
6083 | The current host and target character set is `iso-8859-1'. | |
6084 | (gdb) | |
10998722 | 6085 | @end smallexample |
a0eb71c5 KB |
6086 | |
6087 | For the sake of printing this manual, let's use @sc{ascii} as our | |
6088 | initial character set: | |
6089 | @smallexample | |
6090 | (gdb) set charset ascii | |
6091 | (gdb) show charset | |
6092 | The current host and target character set is `ascii'. | |
6093 | (gdb) | |
10998722 | 6094 | @end smallexample |
a0eb71c5 KB |
6095 | |
6096 | Let's assume that @sc{ascii} is indeed the correct character set for our | |
6097 | host system --- in other words, let's assume that if @value{GDBN} prints | |
6098 | characters using the @sc{ascii} character set, our terminal will display | |
6099 | them properly. Since our current target character set is also | |
6100 | @sc{ascii}, the contents of @code{ascii_hello} print legibly: | |
6101 | ||
6102 | @smallexample | |
6103 | (gdb) print ascii_hello | |
6104 | $1 = 0x401698 "Hello, world!\n" | |
6105 | (gdb) print ascii_hello[0] | |
6106 | $2 = 72 'H' | |
6107 | (gdb) | |
10998722 | 6108 | @end smallexample |
a0eb71c5 KB |
6109 | |
6110 | @value{GDBN} uses the target character set for character and string | |
6111 | literals you use in expressions: | |
6112 | ||
6113 | @smallexample | |
6114 | (gdb) print '+' | |
6115 | $3 = 43 '+' | |
6116 | (gdb) | |
10998722 | 6117 | @end smallexample |
a0eb71c5 KB |
6118 | |
6119 | The @sc{ascii} character set uses the number 43 to encode the @samp{+} | |
6120 | character. | |
6121 | ||
6122 | @value{GDBN} relies on the user to tell it which character set the | |
6123 | target program uses. If we print @code{ibm1047_hello} while our target | |
6124 | character set is still @sc{ascii}, we get jibberish: | |
6125 | ||
6126 | @smallexample | |
6127 | (gdb) print ibm1047_hello | |
6128 | $4 = 0x4016a8 "\310\205\223\223\226k@@\246\226\231\223\204Z%" | |
6129 | (gdb) print ibm1047_hello[0] | |
6130 | $5 = 200 '\310' | |
6131 | (gdb) | |
10998722 | 6132 | @end smallexample |
a0eb71c5 KB |
6133 | |
6134 | If we invoke the @code{set target-charset} command without an argument, | |
6135 | @value{GDBN} tells us the character sets it supports: | |
6136 | ||
6137 | @smallexample | |
6138 | (gdb) set target-charset | |
6139 | Valid character sets are: | |
6140 | ascii * | |
6141 | iso-8859-1 * | |
6142 | ebcdic-us | |
6143 | ibm1047 | |
6144 | * - can be used as a host character set | |
10998722 | 6145 | @end smallexample |
a0eb71c5 KB |
6146 | |
6147 | We can select @sc{ibm1047} as our target character set, and examine the | |
6148 | program's strings again. Now the @sc{ascii} string is wrong, but | |
6149 | @value{GDBN} translates the contents of @code{ibm1047_hello} from the | |
6150 | target character set, @sc{ibm1047}, to the host character set, | |
6151 | @sc{ascii}, and they display correctly: | |
6152 | ||
6153 | @smallexample | |
6154 | (gdb) set target-charset ibm1047 | |
6155 | (gdb) show charset | |
6156 | The current host character set is `ascii'. | |
6157 | The current target character set is `ibm1047'. | |
6158 | (gdb) print ascii_hello | |
6159 | $6 = 0x401698 "\110\145%%?\054\040\167?\162%\144\041\012" | |
6160 | (gdb) print ascii_hello[0] | |
6161 | $7 = 72 '\110' | |
6162 | (gdb) print ibm1047_hello | |
6163 | $8 = 0x4016a8 "Hello, world!\n" | |
6164 | (gdb) print ibm1047_hello[0] | |
6165 | $9 = 200 'H' | |
6166 | (gdb) | |
10998722 | 6167 | @end smallexample |
a0eb71c5 KB |
6168 | |
6169 | As above, @value{GDBN} uses the target character set for character and | |
6170 | string literals you use in expressions: | |
6171 | ||
6172 | @smallexample | |
6173 | (gdb) print '+' | |
6174 | $10 = 78 '+' | |
6175 | (gdb) | |
10998722 | 6176 | @end smallexample |
a0eb71c5 KB |
6177 | |
6178 | The IBM1047 character set uses the number 78 to encode the @samp{+} | |
6179 | character. | |
6180 | ||
6181 | ||
e2e0bcd1 JB |
6182 | @node Macros |
6183 | @chapter C Preprocessor Macros | |
6184 | ||
6185 | Some languages, such as C and C++, provide a way to define and invoke | |
6186 | ``preprocessor macros'' which expand into strings of tokens. | |
6187 | @value{GDBN} can evaluate expressions containing macro invocations, show | |
6188 | the result of macro expansion, and show a macro's definition, including | |
6189 | where it was defined. | |
6190 | ||
6191 | You may need to compile your program specially to provide @value{GDBN} | |
6192 | with information about preprocessor macros. Most compilers do not | |
6193 | include macros in their debugging information, even when you compile | |
6194 | with the @option{-g} flag. @xref{Compilation}. | |
6195 | ||
6196 | A program may define a macro at one point, remove that definition later, | |
6197 | and then provide a different definition after that. Thus, at different | |
6198 | points in the program, a macro may have different definitions, or have | |
6199 | no definition at all. If there is a current stack frame, @value{GDBN} | |
6200 | uses the macros in scope at that frame's source code line. Otherwise, | |
6201 | @value{GDBN} uses the macros in scope at the current listing location; | |
6202 | see @ref{List}. | |
6203 | ||
6204 | At the moment, @value{GDBN} does not support the @code{##} | |
6205 | token-splicing operator, the @code{#} stringification operator, or | |
6206 | variable-arity macros. | |
6207 | ||
6208 | Whenever @value{GDBN} evaluates an expression, it always expands any | |
6209 | macro invocations present in the expression. @value{GDBN} also provides | |
6210 | the following commands for working with macros explicitly. | |
6211 | ||
6212 | @table @code | |
6213 | ||
6214 | @kindex macro expand | |
6215 | @cindex macro expansion, showing the results of preprocessor | |
6216 | @cindex preprocessor macro expansion, showing the results of | |
6217 | @cindex expanding preprocessor macros | |
6218 | @item macro expand @var{expression} | |
6219 | @itemx macro exp @var{expression} | |
6220 | Show the results of expanding all preprocessor macro invocations in | |
6221 | @var{expression}. Since @value{GDBN} simply expands macros, but does | |
6222 | not parse the result, @var{expression} need not be a valid expression; | |
6223 | it can be any string of tokens. | |
6224 | ||
6225 | @kindex macro expand-once | |
6226 | @item macro expand-once @var{expression} | |
6227 | @itemx macro exp1 @var{expression} | |
6228 | @i{(This command is not yet implemented.)} Show the results of | |
6229 | expanding those preprocessor macro invocations that appear explicitly in | |
6230 | @var{expression}. Macro invocations appearing in that expansion are | |
6231 | left unchanged. This command allows you to see the effect of a | |
6232 | particular macro more clearly, without being confused by further | |
6233 | expansions. Since @value{GDBN} simply expands macros, but does not | |
6234 | parse the result, @var{expression} need not be a valid expression; it | |
6235 | can be any string of tokens. | |
6236 | ||
475b0867 | 6237 | @kindex info macro |
e2e0bcd1 JB |
6238 | @cindex macro definition, showing |
6239 | @cindex definition, showing a macro's | |
475b0867 | 6240 | @item info macro @var{macro} |
e2e0bcd1 JB |
6241 | Show the definition of the macro named @var{macro}, and describe the |
6242 | source location where that definition was established. | |
6243 | ||
6244 | @kindex macro define | |
6245 | @cindex user-defined macros | |
6246 | @cindex defining macros interactively | |
6247 | @cindex macros, user-defined | |
6248 | @item macro define @var{macro} @var{replacement-list} | |
6249 | @itemx macro define @var{macro}(@var{arglist}) @var{replacement-list} | |
6250 | @i{(This command is not yet implemented.)} Introduce a definition for a | |
6251 | preprocessor macro named @var{macro}, invocations of which are replaced | |
6252 | by the tokens given in @var{replacement-list}. The first form of this | |
6253 | command defines an ``object-like'' macro, which takes no arguments; the | |
6254 | second form defines a ``function-like'' macro, which takes the arguments | |
6255 | given in @var{arglist}. | |
6256 | ||
6257 | A definition introduced by this command is in scope in every expression | |
6258 | evaluated in @value{GDBN}, until it is removed with the @command{macro | |
6259 | undef} command, described below. The definition overrides all | |
6260 | definitions for @var{macro} present in the program being debugged, as | |
6261 | well as any previous user-supplied definition. | |
6262 | ||
6263 | @kindex macro undef | |
6264 | @item macro undef @var{macro} | |
6265 | @i{(This command is not yet implemented.)} Remove any user-supplied | |
6266 | definition for the macro named @var{macro}. This command only affects | |
6267 | definitions provided with the @command{macro define} command, described | |
6268 | above; it cannot remove definitions present in the program being | |
6269 | debugged. | |
6270 | ||
6271 | @end table | |
6272 | ||
6273 | @cindex macros, example of debugging with | |
6274 | Here is a transcript showing the above commands in action. First, we | |
6275 | show our source files: | |
6276 | ||
6277 | @smallexample | |
6278 | $ cat sample.c | |
6279 | #include <stdio.h> | |
6280 | #include "sample.h" | |
6281 | ||
6282 | #define M 42 | |
6283 | #define ADD(x) (M + x) | |
6284 | ||
6285 | main () | |
6286 | @{ | |
6287 | #define N 28 | |
6288 | printf ("Hello, world!\n"); | |
6289 | #undef N | |
6290 | printf ("We're so creative.\n"); | |
6291 | #define N 1729 | |
6292 | printf ("Goodbye, world!\n"); | |
6293 | @} | |
6294 | $ cat sample.h | |
6295 | #define Q < | |
6296 | $ | |
6297 | @end smallexample | |
6298 | ||
6299 | Now, we compile the program using the @sc{gnu} C compiler, @value{NGCC}. | |
6300 | We pass the @option{-gdwarf-2} and @option{-g3} flags to ensure the | |
6301 | compiler includes information about preprocessor macros in the debugging | |
6302 | information. | |
6303 | ||
6304 | @smallexample | |
6305 | $ gcc -gdwarf-2 -g3 sample.c -o sample | |
6306 | $ | |
6307 | @end smallexample | |
6308 | ||
6309 | Now, we start @value{GDBN} on our sample program: | |
6310 | ||
6311 | @smallexample | |
6312 | $ gdb -nw sample | |
6313 | GNU gdb 2002-05-06-cvs | |
6314 | Copyright 2002 Free Software Foundation, Inc. | |
6315 | GDB is free software, @dots{} | |
6316 | (gdb) | |
6317 | @end smallexample | |
6318 | ||
6319 | We can expand macros and examine their definitions, even when the | |
6320 | program is not running. @value{GDBN} uses the current listing position | |
6321 | to decide which macro definitions are in scope: | |
6322 | ||
6323 | @smallexample | |
6324 | (gdb) list main | |
6325 | 3 | |
6326 | 4 #define M 42 | |
6327 | 5 #define ADD(x) (M + x) | |
6328 | 6 | |
6329 | 7 main () | |
6330 | 8 @{ | |
6331 | 9 #define N 28 | |
6332 | 10 printf ("Hello, world!\n"); | |
6333 | 11 #undef N | |
6334 | 12 printf ("We're so creative.\n"); | |
475b0867 | 6335 | (gdb) info macro ADD |
e2e0bcd1 JB |
6336 | Defined at /home/jimb/gdb/macros/play/sample.c:5 |
6337 | #define ADD(x) (M + x) | |
475b0867 | 6338 | (gdb) info macro Q |
e2e0bcd1 JB |
6339 | Defined at /home/jimb/gdb/macros/play/sample.h:1 |
6340 | included at /home/jimb/gdb/macros/play/sample.c:2 | |
6341 | #define Q < | |
6342 | (gdb) macro expand ADD(1) | |
6343 | expands to: (42 + 1) | |
6344 | (gdb) macro expand-once ADD(1) | |
6345 | expands to: once (M + 1) | |
6346 | (gdb) | |
6347 | @end smallexample | |
6348 | ||
6349 | In the example above, note that @command{macro expand-once} expands only | |
6350 | the macro invocation explicit in the original text --- the invocation of | |
6351 | @code{ADD} --- but does not expand the invocation of the macro @code{M}, | |
6352 | which was introduced by @code{ADD}. | |
6353 | ||
6354 | Once the program is running, GDB uses the macro definitions in force at | |
6355 | the source line of the current stack frame: | |
6356 | ||
6357 | @smallexample | |
6358 | (gdb) break main | |
6359 | Breakpoint 1 at 0x8048370: file sample.c, line 10. | |
6360 | (gdb) run | |
6361 | Starting program: /home/jimb/gdb/macros/play/sample | |
6362 | ||
6363 | Breakpoint 1, main () at sample.c:10 | |
6364 | 10 printf ("Hello, world!\n"); | |
6365 | (gdb) | |
6366 | @end smallexample | |
6367 | ||
6368 | At line 10, the definition of the macro @code{N} at line 9 is in force: | |
6369 | ||
6370 | @smallexample | |
475b0867 | 6371 | (gdb) info macro N |
e2e0bcd1 JB |
6372 | Defined at /home/jimb/gdb/macros/play/sample.c:9 |
6373 | #define N 28 | |
6374 | (gdb) macro expand N Q M | |
6375 | expands to: 28 < 42 | |
6376 | (gdb) print N Q M | |
6377 | $1 = 1 | |
6378 | (gdb) | |
6379 | @end smallexample | |
6380 | ||
6381 | As we step over directives that remove @code{N}'s definition, and then | |
6382 | give it a new definition, @value{GDBN} finds the definition (or lack | |
6383 | thereof) in force at each point: | |
6384 | ||
6385 | @smallexample | |
6386 | (gdb) next | |
6387 | Hello, world! | |
6388 | 12 printf ("We're so creative.\n"); | |
475b0867 | 6389 | (gdb) info macro N |
e2e0bcd1 JB |
6390 | The symbol `N' has no definition as a C/C++ preprocessor macro |
6391 | at /home/jimb/gdb/macros/play/sample.c:12 | |
6392 | (gdb) next | |
6393 | We're so creative. | |
6394 | 14 printf ("Goodbye, world!\n"); | |
475b0867 | 6395 | (gdb) info macro N |
e2e0bcd1 JB |
6396 | Defined at /home/jimb/gdb/macros/play/sample.c:13 |
6397 | #define N 1729 | |
6398 | (gdb) macro expand N Q M | |
6399 | expands to: 1729 < 42 | |
6400 | (gdb) print N Q M | |
6401 | $2 = 0 | |
6402 | (gdb) | |
6403 | @end smallexample | |
6404 | ||
6405 | ||
b37052ae EZ |
6406 | @node Tracepoints |
6407 | @chapter Tracepoints | |
6408 | @c This chapter is based on the documentation written by Michael | |
6409 | @c Snyder, David Taylor, Jim Blandy, and Elena Zannoni. | |
6410 | ||
6411 | @cindex tracepoints | |
6412 | In some applications, it is not feasible for the debugger to interrupt | |
6413 | the program's execution long enough for the developer to learn | |
6414 | anything helpful about its behavior. If the program's correctness | |
6415 | depends on its real-time behavior, delays introduced by a debugger | |
6416 | might cause the program to change its behavior drastically, or perhaps | |
6417 | fail, even when the code itself is correct. It is useful to be able | |
6418 | to observe the program's behavior without interrupting it. | |
6419 | ||
6420 | Using @value{GDBN}'s @code{trace} and @code{collect} commands, you can | |
6421 | specify locations in the program, called @dfn{tracepoints}, and | |
6422 | arbitrary expressions to evaluate when those tracepoints are reached. | |
6423 | Later, using the @code{tfind} command, you can examine the values | |
6424 | those expressions had when the program hit the tracepoints. The | |
6425 | expressions may also denote objects in memory---structures or arrays, | |
6426 | for example---whose values @value{GDBN} should record; while visiting | |
6427 | a particular tracepoint, you may inspect those objects as if they were | |
6428 | in memory at that moment. However, because @value{GDBN} records these | |
6429 | values without interacting with you, it can do so quickly and | |
6430 | unobtrusively, hopefully not disturbing the program's behavior. | |
6431 | ||
6432 | The tracepoint facility is currently available only for remote | |
2c0069bb EZ |
6433 | targets. @xref{Targets}. In addition, your remote target must know how |
6434 | to collect trace data. This functionality is implemented in the remote | |
6435 | stub; however, none of the stubs distributed with @value{GDBN} support | |
6436 | tracepoints as of this writing. | |
b37052ae EZ |
6437 | |
6438 | This chapter describes the tracepoint commands and features. | |
6439 | ||
6440 | @menu | |
6441 | * Set Tracepoints:: | |
6442 | * Analyze Collected Data:: | |
6443 | * Tracepoint Variables:: | |
6444 | @end menu | |
6445 | ||
6446 | @node Set Tracepoints | |
6447 | @section Commands to Set Tracepoints | |
6448 | ||
6449 | Before running such a @dfn{trace experiment}, an arbitrary number of | |
6450 | tracepoints can be set. Like a breakpoint (@pxref{Set Breaks}), a | |
6451 | tracepoint has a number assigned to it by @value{GDBN}. Like with | |
6452 | breakpoints, tracepoint numbers are successive integers starting from | |
6453 | one. Many of the commands associated with tracepoints take the | |
6454 | tracepoint number as their argument, to identify which tracepoint to | |
6455 | work on. | |
6456 | ||
6457 | For each tracepoint, you can specify, in advance, some arbitrary set | |
6458 | of data that you want the target to collect in the trace buffer when | |
6459 | it hits that tracepoint. The collected data can include registers, | |
6460 | local variables, or global data. Later, you can use @value{GDBN} | |
6461 | commands to examine the values these data had at the time the | |
6462 | tracepoint was hit. | |
6463 | ||
6464 | This section describes commands to set tracepoints and associated | |
6465 | conditions and actions. | |
6466 | ||
6467 | @menu | |
6468 | * Create and Delete Tracepoints:: | |
6469 | * Enable and Disable Tracepoints:: | |
6470 | * Tracepoint Passcounts:: | |
6471 | * Tracepoint Actions:: | |
6472 | * Listing Tracepoints:: | |
6473 | * Starting and Stopping Trace Experiment:: | |
6474 | @end menu | |
6475 | ||
6476 | @node Create and Delete Tracepoints | |
6477 | @subsection Create and Delete Tracepoints | |
6478 | ||
6479 | @table @code | |
6480 | @cindex set tracepoint | |
6481 | @kindex trace | |
6482 | @item trace | |
6483 | The @code{trace} command is very similar to the @code{break} command. | |
6484 | Its argument can be a source line, a function name, or an address in | |
6485 | the target program. @xref{Set Breaks}. The @code{trace} command | |
6486 | defines a tracepoint, which is a point in the target program where the | |
6487 | debugger will briefly stop, collect some data, and then allow the | |
6488 | program to continue. Setting a tracepoint or changing its commands | |
6489 | doesn't take effect until the next @code{tstart} command; thus, you | |
6490 | cannot change the tracepoint attributes once a trace experiment is | |
6491 | running. | |
6492 | ||
6493 | Here are some examples of using the @code{trace} command: | |
6494 | ||
6495 | @smallexample | |
6496 | (@value{GDBP}) @b{trace foo.c:121} // a source file and line number | |
6497 | ||
6498 | (@value{GDBP}) @b{trace +2} // 2 lines forward | |
6499 | ||
6500 | (@value{GDBP}) @b{trace my_function} // first source line of function | |
6501 | ||
6502 | (@value{GDBP}) @b{trace *my_function} // EXACT start address of function | |
6503 | ||
6504 | (@value{GDBP}) @b{trace *0x2117c4} // an address | |
6505 | @end smallexample | |
6506 | ||
6507 | @noindent | |
6508 | You can abbreviate @code{trace} as @code{tr}. | |
6509 | ||
6510 | @vindex $tpnum | |
6511 | @cindex last tracepoint number | |
6512 | @cindex recent tracepoint number | |
6513 | @cindex tracepoint number | |
6514 | The convenience variable @code{$tpnum} records the tracepoint number | |
6515 | of the most recently set tracepoint. | |
6516 | ||
6517 | @kindex delete tracepoint | |
6518 | @cindex tracepoint deletion | |
6519 | @item delete tracepoint @r{[}@var{num}@r{]} | |
6520 | Permanently delete one or more tracepoints. With no argument, the | |
6521 | default is to delete all tracepoints. | |
6522 | ||
6523 | Examples: | |
6524 | ||
6525 | @smallexample | |
6526 | (@value{GDBP}) @b{delete trace 1 2 3} // remove three tracepoints | |
6527 | ||
6528 | (@value{GDBP}) @b{delete trace} // remove all tracepoints | |
6529 | @end smallexample | |
6530 | ||
6531 | @noindent | |
6532 | You can abbreviate this command as @code{del tr}. | |
6533 | @end table | |
6534 | ||
6535 | @node Enable and Disable Tracepoints | |
6536 | @subsection Enable and Disable Tracepoints | |
6537 | ||
6538 | @table @code | |
6539 | @kindex disable tracepoint | |
6540 | @item disable tracepoint @r{[}@var{num}@r{]} | |
6541 | Disable tracepoint @var{num}, or all tracepoints if no argument | |
6542 | @var{num} is given. A disabled tracepoint will have no effect during | |
6543 | the next trace experiment, but it is not forgotten. You can re-enable | |
6544 | a disabled tracepoint using the @code{enable tracepoint} command. | |
6545 | ||
6546 | @kindex enable tracepoint | |
6547 | @item enable tracepoint @r{[}@var{num}@r{]} | |
6548 | Enable tracepoint @var{num}, or all tracepoints. The enabled | |
6549 | tracepoints will become effective the next time a trace experiment is | |
6550 | run. | |
6551 | @end table | |
6552 | ||
6553 | @node Tracepoint Passcounts | |
6554 | @subsection Tracepoint Passcounts | |
6555 | ||
6556 | @table @code | |
6557 | @kindex passcount | |
6558 | @cindex tracepoint pass count | |
6559 | @item passcount @r{[}@var{n} @r{[}@var{num}@r{]]} | |
6560 | Set the @dfn{passcount} of a tracepoint. The passcount is a way to | |
6561 | automatically stop a trace experiment. If a tracepoint's passcount is | |
6562 | @var{n}, then the trace experiment will be automatically stopped on | |
6563 | the @var{n}'th time that tracepoint is hit. If the tracepoint number | |
6564 | @var{num} is not specified, the @code{passcount} command sets the | |
6565 | passcount of the most recently defined tracepoint. If no passcount is | |
6566 | given, the trace experiment will run until stopped explicitly by the | |
6567 | user. | |
6568 | ||
6569 | Examples: | |
6570 | ||
6571 | @smallexample | |
6826cf00 EZ |
6572 | (@value{GDBP}) @b{passcount 5 2} // Stop on the 5th execution of |
6573 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// tracepoint 2} | |
b37052ae EZ |
6574 | |
6575 | (@value{GDBP}) @b{passcount 12} // Stop on the 12th execution of the | |
6826cf00 | 6576 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// most recently defined tracepoint.} |
b37052ae EZ |
6577 | (@value{GDBP}) @b{trace foo} |
6578 | (@value{GDBP}) @b{pass 3} | |
6579 | (@value{GDBP}) @b{trace bar} | |
6580 | (@value{GDBP}) @b{pass 2} | |
6581 | (@value{GDBP}) @b{trace baz} | |
6582 | (@value{GDBP}) @b{pass 1} // Stop tracing when foo has been | |
6826cf00 EZ |
6583 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// executed 3 times OR when bar has} |
6584 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// been executed 2 times} | |
6585 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// OR when baz has been executed 1 time.} | |
b37052ae EZ |
6586 | @end smallexample |
6587 | @end table | |
6588 | ||
6589 | @node Tracepoint Actions | |
6590 | @subsection Tracepoint Action Lists | |
6591 | ||
6592 | @table @code | |
6593 | @kindex actions | |
6594 | @cindex tracepoint actions | |
6595 | @item actions @r{[}@var{num}@r{]} | |
6596 | This command will prompt for a list of actions to be taken when the | |
6597 | tracepoint is hit. If the tracepoint number @var{num} is not | |
6598 | specified, this command sets the actions for the one that was most | |
6599 | recently defined (so that you can define a tracepoint and then say | |
6600 | @code{actions} without bothering about its number). You specify the | |
6601 | actions themselves on the following lines, one action at a time, and | |
6602 | terminate the actions list with a line containing just @code{end}. So | |
6603 | far, the only defined actions are @code{collect} and | |
6604 | @code{while-stepping}. | |
6605 | ||
6606 | @cindex remove actions from a tracepoint | |
6607 | To remove all actions from a tracepoint, type @samp{actions @var{num}} | |
6608 | and follow it immediately with @samp{end}. | |
6609 | ||
6610 | @smallexample | |
6611 | (@value{GDBP}) @b{collect @var{data}} // collect some data | |
6612 | ||
6826cf00 | 6613 | (@value{GDBP}) @b{while-stepping 5} // single-step 5 times, collect data |
b37052ae | 6614 | |
6826cf00 | 6615 | (@value{GDBP}) @b{end} // signals the end of actions. |
b37052ae EZ |
6616 | @end smallexample |
6617 | ||
6618 | In the following example, the action list begins with @code{collect} | |
6619 | commands indicating the things to be collected when the tracepoint is | |
6620 | hit. Then, in order to single-step and collect additional data | |
6621 | following the tracepoint, a @code{while-stepping} command is used, | |
6622 | followed by the list of things to be collected while stepping. The | |
6623 | @code{while-stepping} command is terminated by its own separate | |
6624 | @code{end} command. Lastly, the action list is terminated by an | |
6625 | @code{end} command. | |
6626 | ||
6627 | @smallexample | |
6628 | (@value{GDBP}) @b{trace foo} | |
6629 | (@value{GDBP}) @b{actions} | |
6630 | Enter actions for tracepoint 1, one per line: | |
6631 | > collect bar,baz | |
6632 | > collect $regs | |
6633 | > while-stepping 12 | |
6634 | > collect $fp, $sp | |
6635 | > end | |
6636 | end | |
6637 | @end smallexample | |
6638 | ||
6639 | @kindex collect @r{(tracepoints)} | |
6640 | @item collect @var{expr1}, @var{expr2}, @dots{} | |
6641 | Collect values of the given expressions when the tracepoint is hit. | |
6642 | This command accepts a comma-separated list of any valid expressions. | |
6643 | In addition to global, static, or local variables, the following | |
6644 | special arguments are supported: | |
6645 | ||
6646 | @table @code | |
6647 | @item $regs | |
6648 | collect all registers | |
6649 | ||
6650 | @item $args | |
6651 | collect all function arguments | |
6652 | ||
6653 | @item $locals | |
6654 | collect all local variables. | |
6655 | @end table | |
6656 | ||
6657 | You can give several consecutive @code{collect} commands, each one | |
6658 | with a single argument, or one @code{collect} command with several | |
6659 | arguments separated by commas: the effect is the same. | |
6660 | ||
f5c37c66 EZ |
6661 | The command @code{info scope} (@pxref{Symbols, info scope}) is |
6662 | particularly useful for figuring out what data to collect. | |
6663 | ||
b37052ae EZ |
6664 | @kindex while-stepping @r{(tracepoints)} |
6665 | @item while-stepping @var{n} | |
6666 | Perform @var{n} single-step traces after the tracepoint, collecting | |
6667 | new data at each step. The @code{while-stepping} command is | |
6668 | followed by the list of what to collect while stepping (followed by | |
6669 | its own @code{end} command): | |
6670 | ||
6671 | @smallexample | |
6672 | > while-stepping 12 | |
6673 | > collect $regs, myglobal | |
6674 | > end | |
6675 | > | |
6676 | @end smallexample | |
6677 | ||
6678 | @noindent | |
6679 | You may abbreviate @code{while-stepping} as @code{ws} or | |
6680 | @code{stepping}. | |
6681 | @end table | |
6682 | ||
6683 | @node Listing Tracepoints | |
6684 | @subsection Listing Tracepoints | |
6685 | ||
6686 | @table @code | |
6687 | @kindex info tracepoints | |
6688 | @cindex information about tracepoints | |
6689 | @item info tracepoints @r{[}@var{num}@r{]} | |
8a037dd7 | 6690 | Display information about the tracepoint @var{num}. If you don't specify |
798c8bc6 | 6691 | a tracepoint number, displays information about all the tracepoints |
b37052ae EZ |
6692 | defined so far. For each tracepoint, the following information is |
6693 | shown: | |
6694 | ||
6695 | @itemize @bullet | |
6696 | @item | |
6697 | its number | |
6698 | @item | |
6699 | whether it is enabled or disabled | |
6700 | @item | |
6701 | its address | |
6702 | @item | |
6703 | its passcount as given by the @code{passcount @var{n}} command | |
6704 | @item | |
6705 | its step count as given by the @code{while-stepping @var{n}} command | |
6706 | @item | |
6707 | where in the source files is the tracepoint set | |
6708 | @item | |
6709 | its action list as given by the @code{actions} command | |
6710 | @end itemize | |
6711 | ||
6712 | @smallexample | |
6713 | (@value{GDBP}) @b{info trace} | |
6714 | Num Enb Address PassC StepC What | |
6715 | 1 y 0x002117c4 0 0 <gdb_asm> | |
6826cf00 EZ |
6716 | 2 y 0x0020dc64 0 0 in g_test at g_test.c:1375 |
6717 | 3 y 0x0020b1f4 0 0 in get_data at ../foo.c:41 | |
b37052ae EZ |
6718 | (@value{GDBP}) |
6719 | @end smallexample | |
6720 | ||
6721 | @noindent | |
6722 | This command can be abbreviated @code{info tp}. | |
6723 | @end table | |
6724 | ||
6725 | @node Starting and Stopping Trace Experiment | |
6726 | @subsection Starting and Stopping Trace Experiment | |
6727 | ||
6728 | @table @code | |
6729 | @kindex tstart | |
6730 | @cindex start a new trace experiment | |
6731 | @cindex collected data discarded | |
6732 | @item tstart | |
6733 | This command takes no arguments. It starts the trace experiment, and | |
6734 | begins collecting data. This has the side effect of discarding all | |
6735 | the data collected in the trace buffer during the previous trace | |
6736 | experiment. | |
6737 | ||
6738 | @kindex tstop | |
6739 | @cindex stop a running trace experiment | |
6740 | @item tstop | |
6741 | This command takes no arguments. It ends the trace experiment, and | |
6742 | stops collecting data. | |
6743 | ||
6744 | @strong{Note:} a trace experiment and data collection may stop | |
6745 | automatically if any tracepoint's passcount is reached | |
6746 | (@pxref{Tracepoint Passcounts}), or if the trace buffer becomes full. | |
6747 | ||
6748 | @kindex tstatus | |
6749 | @cindex status of trace data collection | |
6750 | @cindex trace experiment, status of | |
6751 | @item tstatus | |
6752 | This command displays the status of the current trace data | |
6753 | collection. | |
6754 | @end table | |
6755 | ||
6756 | Here is an example of the commands we described so far: | |
6757 | ||
6758 | @smallexample | |
6759 | (@value{GDBP}) @b{trace gdb_c_test} | |
6760 | (@value{GDBP}) @b{actions} | |
6761 | Enter actions for tracepoint #1, one per line. | |
6762 | > collect $regs,$locals,$args | |
6763 | > while-stepping 11 | |
6764 | > collect $regs | |
6765 | > end | |
6766 | > end | |
6767 | (@value{GDBP}) @b{tstart} | |
6768 | [time passes @dots{}] | |
6769 | (@value{GDBP}) @b{tstop} | |
6770 | @end smallexample | |
6771 | ||
6772 | ||
6773 | @node Analyze Collected Data | |
6774 | @section Using the collected data | |
6775 | ||
6776 | After the tracepoint experiment ends, you use @value{GDBN} commands | |
6777 | for examining the trace data. The basic idea is that each tracepoint | |
6778 | collects a trace @dfn{snapshot} every time it is hit and another | |
6779 | snapshot every time it single-steps. All these snapshots are | |
6780 | consecutively numbered from zero and go into a buffer, and you can | |
6781 | examine them later. The way you examine them is to @dfn{focus} on a | |
6782 | specific trace snapshot. When the remote stub is focused on a trace | |
6783 | snapshot, it will respond to all @value{GDBN} requests for memory and | |
6784 | registers by reading from the buffer which belongs to that snapshot, | |
6785 | rather than from @emph{real} memory or registers of the program being | |
6786 | debugged. This means that @strong{all} @value{GDBN} commands | |
6787 | (@code{print}, @code{info registers}, @code{backtrace}, etc.) will | |
6788 | behave as if we were currently debugging the program state as it was | |
6789 | when the tracepoint occurred. Any requests for data that are not in | |
6790 | the buffer will fail. | |
6791 | ||
6792 | @menu | |
6793 | * tfind:: How to select a trace snapshot | |
6794 | * tdump:: How to display all data for a snapshot | |
6795 | * save-tracepoints:: How to save tracepoints for a future run | |
6796 | @end menu | |
6797 | ||
6798 | @node tfind | |
6799 | @subsection @code{tfind @var{n}} | |
6800 | ||
6801 | @kindex tfind | |
6802 | @cindex select trace snapshot | |
6803 | @cindex find trace snapshot | |
6804 | The basic command for selecting a trace snapshot from the buffer is | |
6805 | @code{tfind @var{n}}, which finds trace snapshot number @var{n}, | |
6806 | counting from zero. If no argument @var{n} is given, the next | |
6807 | snapshot is selected. | |
6808 | ||
6809 | Here are the various forms of using the @code{tfind} command. | |
6810 | ||
6811 | @table @code | |
6812 | @item tfind start | |
6813 | Find the first snapshot in the buffer. This is a synonym for | |
6814 | @code{tfind 0} (since 0 is the number of the first snapshot). | |
6815 | ||
6816 | @item tfind none | |
6817 | Stop debugging trace snapshots, resume @emph{live} debugging. | |
6818 | ||
6819 | @item tfind end | |
6820 | Same as @samp{tfind none}. | |
6821 | ||
6822 | @item tfind | |
6823 | No argument means find the next trace snapshot. | |
6824 | ||
6825 | @item tfind - | |
6826 | Find the previous trace snapshot before the current one. This permits | |
6827 | retracing earlier steps. | |
6828 | ||
6829 | @item tfind tracepoint @var{num} | |
6830 | Find the next snapshot associated with tracepoint @var{num}. Search | |
6831 | proceeds forward from the last examined trace snapshot. If no | |
6832 | argument @var{num} is given, it means find the next snapshot collected | |
6833 | for the same tracepoint as the current snapshot. | |
6834 | ||
6835 | @item tfind pc @var{addr} | |
6836 | Find the next snapshot associated with the value @var{addr} of the | |
6837 | program counter. Search proceeds forward from the last examined trace | |
6838 | snapshot. If no argument @var{addr} is given, it means find the next | |
6839 | snapshot with the same value of PC as the current snapshot. | |
6840 | ||
6841 | @item tfind outside @var{addr1}, @var{addr2} | |
6842 | Find the next snapshot whose PC is outside the given range of | |
6843 | addresses. | |
6844 | ||
6845 | @item tfind range @var{addr1}, @var{addr2} | |
6846 | Find the next snapshot whose PC is between @var{addr1} and | |
6847 | @var{addr2}. @c FIXME: Is the range inclusive or exclusive? | |
6848 | ||
6849 | @item tfind line @r{[}@var{file}:@r{]}@var{n} | |
6850 | Find the next snapshot associated with the source line @var{n}. If | |
6851 | the optional argument @var{file} is given, refer to line @var{n} in | |
6852 | that source file. Search proceeds forward from the last examined | |
6853 | trace snapshot. If no argument @var{n} is given, it means find the | |
6854 | next line other than the one currently being examined; thus saying | |
6855 | @code{tfind line} repeatedly can appear to have the same effect as | |
6856 | stepping from line to line in a @emph{live} debugging session. | |
6857 | @end table | |
6858 | ||
6859 | The default arguments for the @code{tfind} commands are specifically | |
6860 | designed to make it easy to scan through the trace buffer. For | |
6861 | instance, @code{tfind} with no argument selects the next trace | |
6862 | snapshot, and @code{tfind -} with no argument selects the previous | |
6863 | trace snapshot. So, by giving one @code{tfind} command, and then | |
6864 | simply hitting @key{RET} repeatedly you can examine all the trace | |
6865 | snapshots in order. Or, by saying @code{tfind -} and then hitting | |
6866 | @key{RET} repeatedly you can examine the snapshots in reverse order. | |
6867 | The @code{tfind line} command with no argument selects the snapshot | |
6868 | for the next source line executed. The @code{tfind pc} command with | |
6869 | no argument selects the next snapshot with the same program counter | |
6870 | (PC) as the current frame. The @code{tfind tracepoint} command with | |
6871 | no argument selects the next trace snapshot collected by the same | |
6872 | tracepoint as the current one. | |
6873 | ||
6874 | In addition to letting you scan through the trace buffer manually, | |
6875 | these commands make it easy to construct @value{GDBN} scripts that | |
6876 | scan through the trace buffer and print out whatever collected data | |
6877 | you are interested in. Thus, if we want to examine the PC, FP, and SP | |
6878 | registers from each trace frame in the buffer, we can say this: | |
6879 | ||
6880 | @smallexample | |
6881 | (@value{GDBP}) @b{tfind start} | |
6882 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
6883 | > printf "Frame %d, PC = %08X, SP = %08X, FP = %08X\n", \ | |
6884 | $trace_frame, $pc, $sp, $fp | |
6885 | > tfind | |
6886 | > end | |
6887 | ||
6888 | Frame 0, PC = 0020DC64, SP = 0030BF3C, FP = 0030BF44 | |
6889 | Frame 1, PC = 0020DC6C, SP = 0030BF38, FP = 0030BF44 | |
6890 | Frame 2, PC = 0020DC70, SP = 0030BF34, FP = 0030BF44 | |
6891 | Frame 3, PC = 0020DC74, SP = 0030BF30, FP = 0030BF44 | |
6892 | Frame 4, PC = 0020DC78, SP = 0030BF2C, FP = 0030BF44 | |
6893 | Frame 5, PC = 0020DC7C, SP = 0030BF28, FP = 0030BF44 | |
6894 | Frame 6, PC = 0020DC80, SP = 0030BF24, FP = 0030BF44 | |
6895 | Frame 7, PC = 0020DC84, SP = 0030BF20, FP = 0030BF44 | |
6896 | Frame 8, PC = 0020DC88, SP = 0030BF1C, FP = 0030BF44 | |
6897 | Frame 9, PC = 0020DC8E, SP = 0030BF18, FP = 0030BF44 | |
6898 | Frame 10, PC = 00203F6C, SP = 0030BE3C, FP = 0030BF14 | |
6899 | @end smallexample | |
6900 | ||
6901 | Or, if we want to examine the variable @code{X} at each source line in | |
6902 | the buffer: | |
6903 | ||
6904 | @smallexample | |
6905 | (@value{GDBP}) @b{tfind start} | |
6906 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
6907 | > printf "Frame %d, X == %d\n", $trace_frame, X | |
6908 | > tfind line | |
6909 | > end | |
6910 | ||
6911 | Frame 0, X = 1 | |
6912 | Frame 7, X = 2 | |
6913 | Frame 13, X = 255 | |
6914 | @end smallexample | |
6915 | ||
6916 | @node tdump | |
6917 | @subsection @code{tdump} | |
6918 | @kindex tdump | |
6919 | @cindex dump all data collected at tracepoint | |
6920 | @cindex tracepoint data, display | |
6921 | ||
6922 | This command takes no arguments. It prints all the data collected at | |
6923 | the current trace snapshot. | |
6924 | ||
6925 | @smallexample | |
6926 | (@value{GDBP}) @b{trace 444} | |
6927 | (@value{GDBP}) @b{actions} | |
6928 | Enter actions for tracepoint #2, one per line: | |
6929 | > collect $regs, $locals, $args, gdb_long_test | |
6930 | > end | |
6931 | ||
6932 | (@value{GDBP}) @b{tstart} | |
6933 | ||
6934 | (@value{GDBP}) @b{tfind line 444} | |
6935 | #0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66) | |
6936 | at gdb_test.c:444 | |
6937 | 444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ) | |
6938 | ||
6939 | (@value{GDBP}) @b{tdump} | |
6940 | Data collected at tracepoint 2, trace frame 1: | |
6941 | d0 0xc4aa0085 -995491707 | |
6942 | d1 0x18 24 | |
6943 | d2 0x80 128 | |
6944 | d3 0x33 51 | |
6945 | d4 0x71aea3d 119204413 | |
6946 | d5 0x22 34 | |
6947 | d6 0xe0 224 | |
6948 | d7 0x380035 3670069 | |
6949 | a0 0x19e24a 1696330 | |
6950 | a1 0x3000668 50333288 | |
6951 | a2 0x100 256 | |
6952 | a3 0x322000 3284992 | |
6953 | a4 0x3000698 50333336 | |
6954 | a5 0x1ad3cc 1758156 | |
6955 | fp 0x30bf3c 0x30bf3c | |
6956 | sp 0x30bf34 0x30bf34 | |
6957 | ps 0x0 0 | |
6958 | pc 0x20b2c8 0x20b2c8 | |
6959 | fpcontrol 0x0 0 | |
6960 | fpstatus 0x0 0 | |
6961 | fpiaddr 0x0 0 | |
6962 | p = 0x20e5b4 "gdb-test" | |
6963 | p1 = (void *) 0x11 | |
6964 | p2 = (void *) 0x22 | |
6965 | p3 = (void *) 0x33 | |
6966 | p4 = (void *) 0x44 | |
6967 | p5 = (void *) 0x55 | |
6968 | p6 = (void *) 0x66 | |
6969 | gdb_long_test = 17 '\021' | |
6970 | ||
6971 | (@value{GDBP}) | |
6972 | @end smallexample | |
6973 | ||
6974 | @node save-tracepoints | |
6975 | @subsection @code{save-tracepoints @var{filename}} | |
6976 | @kindex save-tracepoints | |
6977 | @cindex save tracepoints for future sessions | |
6978 | ||
6979 | This command saves all current tracepoint definitions together with | |
6980 | their actions and passcounts, into a file @file{@var{filename}} | |
6981 | suitable for use in a later debugging session. To read the saved | |
6982 | tracepoint definitions, use the @code{source} command (@pxref{Command | |
6983 | Files}). | |
6984 | ||
6985 | @node Tracepoint Variables | |
6986 | @section Convenience Variables for Tracepoints | |
6987 | @cindex tracepoint variables | |
6988 | @cindex convenience variables for tracepoints | |
6989 | ||
6990 | @table @code | |
6991 | @vindex $trace_frame | |
6992 | @item (int) $trace_frame | |
6993 | The current trace snapshot (a.k.a.@: @dfn{frame}) number, or -1 if no | |
6994 | snapshot is selected. | |
6995 | ||
6996 | @vindex $tracepoint | |
6997 | @item (int) $tracepoint | |
6998 | The tracepoint for the current trace snapshot. | |
6999 | ||
7000 | @vindex $trace_line | |
7001 | @item (int) $trace_line | |
7002 | The line number for the current trace snapshot. | |
7003 | ||
7004 | @vindex $trace_file | |
7005 | @item (char []) $trace_file | |
7006 | The source file for the current trace snapshot. | |
7007 | ||
7008 | @vindex $trace_func | |
7009 | @item (char []) $trace_func | |
7010 | The name of the function containing @code{$tracepoint}. | |
7011 | @end table | |
7012 | ||
7013 | Note: @code{$trace_file} is not suitable for use in @code{printf}, | |
7014 | use @code{output} instead. | |
7015 | ||
7016 | Here's a simple example of using these convenience variables for | |
7017 | stepping through all the trace snapshots and printing some of their | |
7018 | data. | |
7019 | ||
7020 | @smallexample | |
7021 | (@value{GDBP}) @b{tfind start} | |
7022 | ||
7023 | (@value{GDBP}) @b{while $trace_frame != -1} | |
7024 | > output $trace_file | |
7025 | > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint | |
7026 | > tfind | |
7027 | > end | |
7028 | @end smallexample | |
7029 | ||
df0cd8c5 JB |
7030 | @node Overlays |
7031 | @chapter Debugging Programs That Use Overlays | |
7032 | @cindex overlays | |
7033 | ||
7034 | If your program is too large to fit completely in your target system's | |
7035 | memory, you can sometimes use @dfn{overlays} to work around this | |
7036 | problem. @value{GDBN} provides some support for debugging programs that | |
7037 | use overlays. | |
7038 | ||
7039 | @menu | |
7040 | * How Overlays Work:: A general explanation of overlays. | |
7041 | * Overlay Commands:: Managing overlays in @value{GDBN}. | |
7042 | * Automatic Overlay Debugging:: @value{GDBN} can find out which overlays are | |
7043 | mapped by asking the inferior. | |
7044 | * Overlay Sample Program:: A sample program using overlays. | |
7045 | @end menu | |
7046 | ||
7047 | @node How Overlays Work | |
7048 | @section How Overlays Work | |
7049 | @cindex mapped overlays | |
7050 | @cindex unmapped overlays | |
7051 | @cindex load address, overlay's | |
7052 | @cindex mapped address | |
7053 | @cindex overlay area | |
7054 | ||
7055 | Suppose you have a computer whose instruction address space is only 64 | |
7056 | kilobytes long, but which has much more memory which can be accessed by | |
7057 | other means: special instructions, segment registers, or memory | |
7058 | management hardware, for example. Suppose further that you want to | |
7059 | adapt a program which is larger than 64 kilobytes to run on this system. | |
7060 | ||
7061 | One solution is to identify modules of your program which are relatively | |
7062 | independent, and need not call each other directly; call these modules | |
7063 | @dfn{overlays}. Separate the overlays from the main program, and place | |
7064 | their machine code in the larger memory. Place your main program in | |
7065 | instruction memory, but leave at least enough space there to hold the | |
7066 | largest overlay as well. | |
7067 | ||
7068 | Now, to call a function located in an overlay, you must first copy that | |
7069 | overlay's machine code from the large memory into the space set aside | |
7070 | for it in the instruction memory, and then jump to its entry point | |
7071 | there. | |
7072 | ||
c928edc0 AC |
7073 | @c NB: In the below the mapped area's size is greater or equal to the |
7074 | @c size of all overlays. This is intentional to remind the developer | |
7075 | @c that overlays don't necessarily need to be the same size. | |
7076 | ||
474c8240 | 7077 | @smallexample |
df0cd8c5 | 7078 | @group |
c928edc0 AC |
7079 | Data Instruction Larger |
7080 | Address Space Address Space Address Space | |
7081 | +-----------+ +-----------+ +-----------+ | |
7082 | | | | | | | | |
7083 | +-----------+ +-----------+ +-----------+<-- overlay 1 | |
7084 | | program | | main | .----| overlay 1 | load address | |
7085 | | variables | | program | | +-----------+ | |
7086 | | and heap | | | | | | | |
7087 | +-----------+ | | | +-----------+<-- overlay 2 | |
7088 | | | +-----------+ | | | load address | |
7089 | +-----------+ | | | .-| overlay 2 | | |
7090 | | | | | | | | |
7091 | mapped --->+-----------+ | | +-----------+ | |
7092 | address | | | | | | | |
7093 | | overlay | <-' | | | | |
7094 | | area | <---' +-----------+<-- overlay 3 | |
7095 | | | <---. | | load address | |
7096 | +-----------+ `--| overlay 3 | | |
7097 | | | | | | |
7098 | +-----------+ | | | |
7099 | +-----------+ | |
7100 | | | | |
7101 | +-----------+ | |
7102 | ||
7103 | @anchor{A code overlay}A code overlay | |
df0cd8c5 | 7104 | @end group |
474c8240 | 7105 | @end smallexample |
df0cd8c5 | 7106 | |
c928edc0 AC |
7107 | The diagram (@pxref{A code overlay}) shows a system with separate data |
7108 | and instruction address spaces. To map an overlay, the program copies | |
7109 | its code from the larger address space to the instruction address space. | |
7110 | Since the overlays shown here all use the same mapped address, only one | |
7111 | may be mapped at a time. For a system with a single address space for | |
7112 | data and instructions, the diagram would be similar, except that the | |
7113 | program variables and heap would share an address space with the main | |
7114 | program and the overlay area. | |
df0cd8c5 JB |
7115 | |
7116 | An overlay loaded into instruction memory and ready for use is called a | |
7117 | @dfn{mapped} overlay; its @dfn{mapped address} is its address in the | |
7118 | instruction memory. An overlay not present (or only partially present) | |
7119 | in instruction memory is called @dfn{unmapped}; its @dfn{load address} | |
7120 | is its address in the larger memory. The mapped address is also called | |
7121 | the @dfn{virtual memory address}, or @dfn{VMA}; the load address is also | |
7122 | called the @dfn{load memory address}, or @dfn{LMA}. | |
7123 | ||
7124 | Unfortunately, overlays are not a completely transparent way to adapt a | |
7125 | program to limited instruction memory. They introduce a new set of | |
7126 | global constraints you must keep in mind as you design your program: | |
7127 | ||
7128 | @itemize @bullet | |
7129 | ||
7130 | @item | |
7131 | Before calling or returning to a function in an overlay, your program | |
7132 | must make sure that overlay is actually mapped. Otherwise, the call or | |
7133 | return will transfer control to the right address, but in the wrong | |
7134 | overlay, and your program will probably crash. | |
7135 | ||
7136 | @item | |
7137 | If the process of mapping an overlay is expensive on your system, you | |
7138 | will need to choose your overlays carefully to minimize their effect on | |
7139 | your program's performance. | |
7140 | ||
7141 | @item | |
7142 | The executable file you load onto your system must contain each | |
7143 | overlay's instructions, appearing at the overlay's load address, not its | |
7144 | mapped address. However, each overlay's instructions must be relocated | |
7145 | and its symbols defined as if the overlay were at its mapped address. | |
7146 | You can use GNU linker scripts to specify different load and relocation | |
7147 | addresses for pieces of your program; see @ref{Overlay Description,,, | |
7148 | ld.info, Using ld: the GNU linker}. | |
7149 | ||
7150 | @item | |
7151 | The procedure for loading executable files onto your system must be able | |
7152 | to load their contents into the larger address space as well as the | |
7153 | instruction and data spaces. | |
7154 | ||
7155 | @end itemize | |
7156 | ||
7157 | The overlay system described above is rather simple, and could be | |
7158 | improved in many ways: | |
7159 | ||
7160 | @itemize @bullet | |
7161 | ||
7162 | @item | |
7163 | If your system has suitable bank switch registers or memory management | |
7164 | hardware, you could use those facilities to make an overlay's load area | |
7165 | contents simply appear at their mapped address in instruction space. | |
7166 | This would probably be faster than copying the overlay to its mapped | |
7167 | area in the usual way. | |
7168 | ||
7169 | @item | |
7170 | If your overlays are small enough, you could set aside more than one | |
7171 | overlay area, and have more than one overlay mapped at a time. | |
7172 | ||
7173 | @item | |
7174 | You can use overlays to manage data, as well as instructions. In | |
7175 | general, data overlays are even less transparent to your design than | |
7176 | code overlays: whereas code overlays only require care when you call or | |
7177 | return to functions, data overlays require care every time you access | |
7178 | the data. Also, if you change the contents of a data overlay, you | |
7179 | must copy its contents back out to its load address before you can copy a | |
7180 | different data overlay into the same mapped area. | |
7181 | ||
7182 | @end itemize | |
7183 | ||
7184 | ||
7185 | @node Overlay Commands | |
7186 | @section Overlay Commands | |
7187 | ||
7188 | To use @value{GDBN}'s overlay support, each overlay in your program must | |
7189 | correspond to a separate section of the executable file. The section's | |
7190 | virtual memory address and load memory address must be the overlay's | |
7191 | mapped and load addresses. Identifying overlays with sections allows | |
7192 | @value{GDBN} to determine the appropriate address of a function or | |
7193 | variable, depending on whether the overlay is mapped or not. | |
7194 | ||
7195 | @value{GDBN}'s overlay commands all start with the word @code{overlay}; | |
7196 | you can abbreviate this as @code{ov} or @code{ovly}. The commands are: | |
7197 | ||
7198 | @table @code | |
7199 | @item overlay off | |
7200 | @kindex overlay off | |
7201 | Disable @value{GDBN}'s overlay support. When overlay support is | |
7202 | disabled, @value{GDBN} assumes that all functions and variables are | |
7203 | always present at their mapped addresses. By default, @value{GDBN}'s | |
7204 | overlay support is disabled. | |
7205 | ||
7206 | @item overlay manual | |
7207 | @kindex overlay manual | |
7208 | @cindex manual overlay debugging | |
7209 | Enable @dfn{manual} overlay debugging. In this mode, @value{GDBN} | |
7210 | relies on you to tell it which overlays are mapped, and which are not, | |
7211 | using the @code{overlay map-overlay} and @code{overlay unmap-overlay} | |
7212 | commands described below. | |
7213 | ||
7214 | @item overlay map-overlay @var{overlay} | |
7215 | @itemx overlay map @var{overlay} | |
7216 | @kindex overlay map-overlay | |
7217 | @cindex map an overlay | |
7218 | Tell @value{GDBN} that @var{overlay} is now mapped; @var{overlay} must | |
7219 | be the name of the object file section containing the overlay. When an | |
7220 | overlay is mapped, @value{GDBN} assumes it can find the overlay's | |
7221 | functions and variables at their mapped addresses. @value{GDBN} assumes | |
7222 | that any other overlays whose mapped ranges overlap that of | |
7223 | @var{overlay} are now unmapped. | |
7224 | ||
7225 | @item overlay unmap-overlay @var{overlay} | |
7226 | @itemx overlay unmap @var{overlay} | |
7227 | @kindex overlay unmap-overlay | |
7228 | @cindex unmap an overlay | |
7229 | Tell @value{GDBN} that @var{overlay} is no longer mapped; @var{overlay} | |
7230 | must be the name of the object file section containing the overlay. | |
7231 | When an overlay is unmapped, @value{GDBN} assumes it can find the | |
7232 | overlay's functions and variables at their load addresses. | |
7233 | ||
7234 | @item overlay auto | |
7235 | @kindex overlay auto | |
7236 | Enable @dfn{automatic} overlay debugging. In this mode, @value{GDBN} | |
7237 | consults a data structure the overlay manager maintains in the inferior | |
7238 | to see which overlays are mapped. For details, see @ref{Automatic | |
7239 | Overlay Debugging}. | |
7240 | ||
7241 | @item overlay load-target | |
7242 | @itemx overlay load | |
7243 | @kindex overlay load-target | |
7244 | @cindex reloading the overlay table | |
7245 | Re-read the overlay table from the inferior. Normally, @value{GDBN} | |
7246 | re-reads the table @value{GDBN} automatically each time the inferior | |
7247 | stops, so this command should only be necessary if you have changed the | |
7248 | overlay mapping yourself using @value{GDBN}. This command is only | |
7249 | useful when using automatic overlay debugging. | |
7250 | ||
7251 | @item overlay list-overlays | |
7252 | @itemx overlay list | |
7253 | @cindex listing mapped overlays | |
7254 | Display a list of the overlays currently mapped, along with their mapped | |
7255 | addresses, load addresses, and sizes. | |
7256 | ||
7257 | @end table | |
7258 | ||
7259 | Normally, when @value{GDBN} prints a code address, it includes the name | |
7260 | of the function the address falls in: | |
7261 | ||
474c8240 | 7262 | @smallexample |
df0cd8c5 JB |
7263 | (gdb) print main |
7264 | $3 = @{int ()@} 0x11a0 <main> | |
474c8240 | 7265 | @end smallexample |
df0cd8c5 JB |
7266 | @noindent |
7267 | When overlay debugging is enabled, @value{GDBN} recognizes code in | |
7268 | unmapped overlays, and prints the names of unmapped functions with | |
7269 | asterisks around them. For example, if @code{foo} is a function in an | |
7270 | unmapped overlay, @value{GDBN} prints it this way: | |
7271 | ||
474c8240 | 7272 | @smallexample |
df0cd8c5 JB |
7273 | (gdb) overlay list |
7274 | No sections are mapped. | |
7275 | (gdb) print foo | |
7276 | $5 = @{int (int)@} 0x100000 <*foo*> | |
474c8240 | 7277 | @end smallexample |
df0cd8c5 JB |
7278 | @noindent |
7279 | When @code{foo}'s overlay is mapped, @value{GDBN} prints the function's | |
7280 | name normally: | |
7281 | ||
474c8240 | 7282 | @smallexample |
df0cd8c5 JB |
7283 | (gdb) overlay list |
7284 | Section .ov.foo.text, loaded at 0x100000 - 0x100034, | |
7285 | mapped at 0x1016 - 0x104a | |
7286 | (gdb) print foo | |
7287 | $6 = @{int (int)@} 0x1016 <foo> | |
474c8240 | 7288 | @end smallexample |
df0cd8c5 JB |
7289 | |
7290 | When overlay debugging is enabled, @value{GDBN} can find the correct | |
7291 | address for functions and variables in an overlay, whether or not the | |
7292 | overlay is mapped. This allows most @value{GDBN} commands, like | |
7293 | @code{break} and @code{disassemble}, to work normally, even on unmapped | |
7294 | code. However, @value{GDBN}'s breakpoint support has some limitations: | |
7295 | ||
7296 | @itemize @bullet | |
7297 | @item | |
7298 | @cindex breakpoints in overlays | |
7299 | @cindex overlays, setting breakpoints in | |
7300 | You can set breakpoints in functions in unmapped overlays, as long as | |
7301 | @value{GDBN} can write to the overlay at its load address. | |
7302 | @item | |
7303 | @value{GDBN} can not set hardware or simulator-based breakpoints in | |
7304 | unmapped overlays. However, if you set a breakpoint at the end of your | |
7305 | overlay manager (and tell @value{GDBN} which overlays are now mapped, if | |
7306 | you are using manual overlay management), @value{GDBN} will re-set its | |
7307 | breakpoints properly. | |
7308 | @end itemize | |
7309 | ||
7310 | ||
7311 | @node Automatic Overlay Debugging | |
7312 | @section Automatic Overlay Debugging | |
7313 | @cindex automatic overlay debugging | |
7314 | ||
7315 | @value{GDBN} can automatically track which overlays are mapped and which | |
7316 | are not, given some simple co-operation from the overlay manager in the | |
7317 | inferior. If you enable automatic overlay debugging with the | |
7318 | @code{overlay auto} command (@pxref{Overlay Commands}), @value{GDBN} | |
7319 | looks in the inferior's memory for certain variables describing the | |
7320 | current state of the overlays. | |
7321 | ||
7322 | Here are the variables your overlay manager must define to support | |
7323 | @value{GDBN}'s automatic overlay debugging: | |
7324 | ||
7325 | @table @asis | |
7326 | ||
7327 | @item @code{_ovly_table}: | |
7328 | This variable must be an array of the following structures: | |
7329 | ||
474c8240 | 7330 | @smallexample |
df0cd8c5 JB |
7331 | struct |
7332 | @{ | |
7333 | /* The overlay's mapped address. */ | |
7334 | unsigned long vma; | |
7335 | ||
7336 | /* The size of the overlay, in bytes. */ | |
7337 | unsigned long size; | |
7338 | ||
7339 | /* The overlay's load address. */ | |
7340 | unsigned long lma; | |
7341 | ||
7342 | /* Non-zero if the overlay is currently mapped; | |
7343 | zero otherwise. */ | |
7344 | unsigned long mapped; | |
7345 | @} | |
474c8240 | 7346 | @end smallexample |
df0cd8c5 JB |
7347 | |
7348 | @item @code{_novlys}: | |
7349 | This variable must be a four-byte signed integer, holding the total | |
7350 | number of elements in @code{_ovly_table}. | |
7351 | ||
7352 | @end table | |
7353 | ||
7354 | To decide whether a particular overlay is mapped or not, @value{GDBN} | |
7355 | looks for an entry in @w{@code{_ovly_table}} whose @code{vma} and | |
7356 | @code{lma} members equal the VMA and LMA of the overlay's section in the | |
7357 | executable file. When @value{GDBN} finds a matching entry, it consults | |
7358 | the entry's @code{mapped} member to determine whether the overlay is | |
7359 | currently mapped. | |
7360 | ||
81d46470 | 7361 | In addition, your overlay manager may define a function called |
def71bfa | 7362 | @code{_ovly_debug_event}. If this function is defined, @value{GDBN} |
81d46470 MS |
7363 | will silently set a breakpoint there. If the overlay manager then |
7364 | calls this function whenever it has changed the overlay table, this | |
7365 | will enable @value{GDBN} to accurately keep track of which overlays | |
7366 | are in program memory, and update any breakpoints that may be set | |
7367 | in overlays. This will allow breakpoints to work even if the | |
7368 | overlays are kept in ROM or other non-writable memory while they | |
7369 | are not being executed. | |
df0cd8c5 JB |
7370 | |
7371 | @node Overlay Sample Program | |
7372 | @section Overlay Sample Program | |
7373 | @cindex overlay example program | |
7374 | ||
7375 | When linking a program which uses overlays, you must place the overlays | |
7376 | at their load addresses, while relocating them to run at their mapped | |
7377 | addresses. To do this, you must write a linker script (@pxref{Overlay | |
7378 | Description,,, ld.info, Using ld: the GNU linker}). Unfortunately, | |
7379 | since linker scripts are specific to a particular host system, target | |
7380 | architecture, and target memory layout, this manual cannot provide | |
7381 | portable sample code demonstrating @value{GDBN}'s overlay support. | |
7382 | ||
7383 | However, the @value{GDBN} source distribution does contain an overlaid | |
7384 | program, with linker scripts for a few systems, as part of its test | |
7385 | suite. The program consists of the following files from | |
7386 | @file{gdb/testsuite/gdb.base}: | |
7387 | ||
7388 | @table @file | |
7389 | @item overlays.c | |
7390 | The main program file. | |
7391 | @item ovlymgr.c | |
7392 | A simple overlay manager, used by @file{overlays.c}. | |
7393 | @item foo.c | |
7394 | @itemx bar.c | |
7395 | @itemx baz.c | |
7396 | @itemx grbx.c | |
7397 | Overlay modules, loaded and used by @file{overlays.c}. | |
7398 | @item d10v.ld | |
7399 | @itemx m32r.ld | |
7400 | Linker scripts for linking the test program on the @code{d10v-elf} | |
7401 | and @code{m32r-elf} targets. | |
7402 | @end table | |
7403 | ||
7404 | You can build the test program using the @code{d10v-elf} GCC | |
7405 | cross-compiler like this: | |
7406 | ||
474c8240 | 7407 | @smallexample |
df0cd8c5 JB |
7408 | $ d10v-elf-gcc -g -c overlays.c |
7409 | $ d10v-elf-gcc -g -c ovlymgr.c | |
7410 | $ d10v-elf-gcc -g -c foo.c | |
7411 | $ d10v-elf-gcc -g -c bar.c | |
7412 | $ d10v-elf-gcc -g -c baz.c | |
7413 | $ d10v-elf-gcc -g -c grbx.c | |
7414 | $ d10v-elf-gcc -g overlays.o ovlymgr.o foo.o bar.o \ | |
7415 | baz.o grbx.o -Wl,-Td10v.ld -o overlays | |
474c8240 | 7416 | @end smallexample |
df0cd8c5 JB |
7417 | |
7418 | The build process is identical for any other architecture, except that | |
7419 | you must substitute the appropriate compiler and linker script for the | |
7420 | target system for @code{d10v-elf-gcc} and @code{d10v.ld}. | |
7421 | ||
7422 | ||
6d2ebf8b | 7423 | @node Languages |
c906108c SS |
7424 | @chapter Using @value{GDBN} with Different Languages |
7425 | @cindex languages | |
7426 | ||
c906108c SS |
7427 | Although programming languages generally have common aspects, they are |
7428 | rarely expressed in the same manner. For instance, in ANSI C, | |
7429 | dereferencing a pointer @code{p} is accomplished by @code{*p}, but in | |
7430 | Modula-2, it is accomplished by @code{p^}. Values can also be | |
5d161b24 | 7431 | represented (and displayed) differently. Hex numbers in C appear as |
c906108c | 7432 | @samp{0x1ae}, while in Modula-2 they appear as @samp{1AEH}. |
c906108c SS |
7433 | |
7434 | @cindex working language | |
7435 | Language-specific information is built into @value{GDBN} for some languages, | |
7436 | allowing you to express operations like the above in your program's | |
7437 | native language, and allowing @value{GDBN} to output values in a manner | |
7438 | consistent with the syntax of your program's native language. The | |
7439 | language you use to build expressions is called the @dfn{working | |
7440 | language}. | |
7441 | ||
7442 | @menu | |
7443 | * Setting:: Switching between source languages | |
7444 | * Show:: Displaying the language | |
c906108c | 7445 | * Checks:: Type and range checks |
c906108c SS |
7446 | * Support:: Supported languages |
7447 | @end menu | |
7448 | ||
6d2ebf8b | 7449 | @node Setting |
c906108c SS |
7450 | @section Switching between source languages |
7451 | ||
7452 | There are two ways to control the working language---either have @value{GDBN} | |
7453 | set it automatically, or select it manually yourself. You can use the | |
7454 | @code{set language} command for either purpose. On startup, @value{GDBN} | |
7455 | defaults to setting the language automatically. The working language is | |
7456 | used to determine how expressions you type are interpreted, how values | |
7457 | are printed, etc. | |
7458 | ||
7459 | In addition to the working language, every source file that | |
7460 | @value{GDBN} knows about has its own working language. For some object | |
7461 | file formats, the compiler might indicate which language a particular | |
7462 | source file is in. However, most of the time @value{GDBN} infers the | |
7463 | language from the name of the file. The language of a source file | |
b37052ae | 7464 | controls whether C@t{++} names are demangled---this way @code{backtrace} can |
c906108c | 7465 | show each frame appropriately for its own language. There is no way to |
d4f3574e SS |
7466 | set the language of a source file from within @value{GDBN}, but you can |
7467 | set the language associated with a filename extension. @xref{Show, , | |
7468 | Displaying the language}. | |
c906108c SS |
7469 | |
7470 | This is most commonly a problem when you use a program, such | |
5d161b24 | 7471 | as @code{cfront} or @code{f2c}, that generates C but is written in |
c906108c SS |
7472 | another language. In that case, make the |
7473 | program use @code{#line} directives in its C output; that way | |
7474 | @value{GDBN} will know the correct language of the source code of the original | |
7475 | program, and will display that source code, not the generated C code. | |
7476 | ||
7477 | @menu | |
7478 | * Filenames:: Filename extensions and languages. | |
7479 | * Manually:: Setting the working language manually | |
7480 | * Automatically:: Having @value{GDBN} infer the source language | |
7481 | @end menu | |
7482 | ||
6d2ebf8b | 7483 | @node Filenames |
c906108c SS |
7484 | @subsection List of filename extensions and languages |
7485 | ||
7486 | If a source file name ends in one of the following extensions, then | |
7487 | @value{GDBN} infers that its language is the one indicated. | |
7488 | ||
7489 | @table @file | |
7490 | ||
7491 | @item .c | |
7492 | C source file | |
7493 | ||
7494 | @item .C | |
7495 | @itemx .cc | |
7496 | @itemx .cp | |
7497 | @itemx .cpp | |
7498 | @itemx .cxx | |
7499 | @itemx .c++ | |
b37052ae | 7500 | C@t{++} source file |
c906108c SS |
7501 | |
7502 | @item .f | |
7503 | @itemx .F | |
7504 | Fortran source file | |
7505 | ||
c906108c SS |
7506 | @item .mod |
7507 | Modula-2 source file | |
c906108c SS |
7508 | |
7509 | @item .s | |
7510 | @itemx .S | |
7511 | Assembler source file. This actually behaves almost like C, but | |
7512 | @value{GDBN} does not skip over function prologues when stepping. | |
7513 | @end table | |
7514 | ||
7515 | In addition, you may set the language associated with a filename | |
7516 | extension. @xref{Show, , Displaying the language}. | |
7517 | ||
6d2ebf8b | 7518 | @node Manually |
c906108c SS |
7519 | @subsection Setting the working language |
7520 | ||
7521 | If you allow @value{GDBN} to set the language automatically, | |
7522 | expressions are interpreted the same way in your debugging session and | |
7523 | your program. | |
7524 | ||
7525 | @kindex set language | |
7526 | If you wish, you may set the language manually. To do this, issue the | |
7527 | command @samp{set language @var{lang}}, where @var{lang} is the name of | |
5d161b24 | 7528 | a language, such as |
c906108c | 7529 | @code{c} or @code{modula-2}. |
c906108c SS |
7530 | For a list of the supported languages, type @samp{set language}. |
7531 | ||
c906108c SS |
7532 | Setting the language manually prevents @value{GDBN} from updating the working |
7533 | language automatically. This can lead to confusion if you try | |
7534 | to debug a program when the working language is not the same as the | |
7535 | source language, when an expression is acceptable to both | |
7536 | languages---but means different things. For instance, if the current | |
7537 | source file were written in C, and @value{GDBN} was parsing Modula-2, a | |
7538 | command such as: | |
7539 | ||
474c8240 | 7540 | @smallexample |
c906108c | 7541 | print a = b + c |
474c8240 | 7542 | @end smallexample |
c906108c SS |
7543 | |
7544 | @noindent | |
7545 | might not have the effect you intended. In C, this means to add | |
7546 | @code{b} and @code{c} and place the result in @code{a}. The result | |
7547 | printed would be the value of @code{a}. In Modula-2, this means to compare | |
7548 | @code{a} to the result of @code{b+c}, yielding a @code{BOOLEAN} value. | |
c906108c | 7549 | |
6d2ebf8b | 7550 | @node Automatically |
c906108c SS |
7551 | @subsection Having @value{GDBN} infer the source language |
7552 | ||
7553 | To have @value{GDBN} set the working language automatically, use | |
7554 | @samp{set language local} or @samp{set language auto}. @value{GDBN} | |
7555 | then infers the working language. That is, when your program stops in a | |
7556 | frame (usually by encountering a breakpoint), @value{GDBN} sets the | |
7557 | working language to the language recorded for the function in that | |
7558 | frame. If the language for a frame is unknown (that is, if the function | |
7559 | or block corresponding to the frame was defined in a source file that | |
7560 | does not have a recognized extension), the current working language is | |
7561 | not changed, and @value{GDBN} issues a warning. | |
7562 | ||
7563 | This may not seem necessary for most programs, which are written | |
7564 | entirely in one source language. However, program modules and libraries | |
7565 | written in one source language can be used by a main program written in | |
7566 | a different source language. Using @samp{set language auto} in this | |
7567 | case frees you from having to set the working language manually. | |
7568 | ||
6d2ebf8b | 7569 | @node Show |
c906108c | 7570 | @section Displaying the language |
c906108c SS |
7571 | |
7572 | The following commands help you find out which language is the | |
7573 | working language, and also what language source files were written in. | |
7574 | ||
7575 | @kindex show language | |
d4f3574e SS |
7576 | @kindex info frame@r{, show the source language} |
7577 | @kindex info source@r{, show the source language} | |
c906108c SS |
7578 | @table @code |
7579 | @item show language | |
7580 | Display the current working language. This is the | |
7581 | language you can use with commands such as @code{print} to | |
7582 | build and compute expressions that may involve variables in your program. | |
7583 | ||
7584 | @item info frame | |
5d161b24 | 7585 | Display the source language for this frame. This language becomes the |
c906108c | 7586 | working language if you use an identifier from this frame. |
5d161b24 | 7587 | @xref{Frame Info, ,Information about a frame}, to identify the other |
c906108c SS |
7588 | information listed here. |
7589 | ||
7590 | @item info source | |
7591 | Display the source language of this source file. | |
5d161b24 | 7592 | @xref{Symbols, ,Examining the Symbol Table}, to identify the other |
c906108c SS |
7593 | information listed here. |
7594 | @end table | |
7595 | ||
7596 | In unusual circumstances, you may have source files with extensions | |
7597 | not in the standard list. You can then set the extension associated | |
7598 | with a language explicitly: | |
7599 | ||
7600 | @kindex set extension-language | |
7601 | @kindex info extensions | |
7602 | @table @code | |
7603 | @item set extension-language @var{.ext} @var{language} | |
7604 | Set source files with extension @var{.ext} to be assumed to be in | |
7605 | the source language @var{language}. | |
7606 | ||
7607 | @item info extensions | |
7608 | List all the filename extensions and the associated languages. | |
7609 | @end table | |
7610 | ||
6d2ebf8b | 7611 | @node Checks |
c906108c SS |
7612 | @section Type and range checking |
7613 | ||
7614 | @quotation | |
7615 | @emph{Warning:} In this release, the @value{GDBN} commands for type and range | |
7616 | checking are included, but they do not yet have any effect. This | |
7617 | section documents the intended facilities. | |
7618 | @end quotation | |
7619 | @c FIXME remove warning when type/range code added | |
7620 | ||
7621 | Some languages are designed to guard you against making seemingly common | |
7622 | errors through a series of compile- and run-time checks. These include | |
7623 | checking the type of arguments to functions and operators, and making | |
7624 | sure mathematical overflows are caught at run time. Checks such as | |
7625 | these help to ensure a program's correctness once it has been compiled | |
7626 | by eliminating type mismatches, and providing active checks for range | |
7627 | errors when your program is running. | |
7628 | ||
7629 | @value{GDBN} can check for conditions like the above if you wish. | |
7630 | Although @value{GDBN} does not check the statements in your program, it | |
7631 | can check expressions entered directly into @value{GDBN} for evaluation via | |
7632 | the @code{print} command, for example. As with the working language, | |
7633 | @value{GDBN} can also decide whether or not to check automatically based on | |
7634 | your program's source language. @xref{Support, ,Supported languages}, | |
7635 | for the default settings of supported languages. | |
7636 | ||
7637 | @menu | |
7638 | * Type Checking:: An overview of type checking | |
7639 | * Range Checking:: An overview of range checking | |
7640 | @end menu | |
7641 | ||
7642 | @cindex type checking | |
7643 | @cindex checks, type | |
6d2ebf8b | 7644 | @node Type Checking |
c906108c SS |
7645 | @subsection An overview of type checking |
7646 | ||
7647 | Some languages, such as Modula-2, are strongly typed, meaning that the | |
7648 | arguments to operators and functions have to be of the correct type, | |
7649 | otherwise an error occurs. These checks prevent type mismatch | |
7650 | errors from ever causing any run-time problems. For example, | |
7651 | ||
7652 | @smallexample | |
7653 | 1 + 2 @result{} 3 | |
7654 | @exdent but | |
7655 | @error{} 1 + 2.3 | |
7656 | @end smallexample | |
7657 | ||
7658 | The second example fails because the @code{CARDINAL} 1 is not | |
7659 | type-compatible with the @code{REAL} 2.3. | |
7660 | ||
5d161b24 DB |
7661 | For the expressions you use in @value{GDBN} commands, you can tell the |
7662 | @value{GDBN} type checker to skip checking; | |
7663 | to treat any mismatches as errors and abandon the expression; | |
7664 | or to only issue warnings when type mismatches occur, | |
c906108c SS |
7665 | but evaluate the expression anyway. When you choose the last of |
7666 | these, @value{GDBN} evaluates expressions like the second example above, but | |
7667 | also issues a warning. | |
7668 | ||
5d161b24 DB |
7669 | Even if you turn type checking off, there may be other reasons |
7670 | related to type that prevent @value{GDBN} from evaluating an expression. | |
7671 | For instance, @value{GDBN} does not know how to add an @code{int} and | |
7672 | a @code{struct foo}. These particular type errors have nothing to do | |
7673 | with the language in use, and usually arise from expressions, such as | |
c906108c SS |
7674 | the one described above, which make little sense to evaluate anyway. |
7675 | ||
7676 | Each language defines to what degree it is strict about type. For | |
7677 | instance, both Modula-2 and C require the arguments to arithmetical | |
7678 | operators to be numbers. In C, enumerated types and pointers can be | |
7679 | represented as numbers, so that they are valid arguments to mathematical | |
7680 | operators. @xref{Support, ,Supported languages}, for further | |
7681 | details on specific languages. | |
7682 | ||
7683 | @value{GDBN} provides some additional commands for controlling the type checker: | |
7684 | ||
d4f3574e | 7685 | @kindex set check@r{, type} |
c906108c SS |
7686 | @kindex set check type |
7687 | @kindex show check type | |
7688 | @table @code | |
7689 | @item set check type auto | |
7690 | Set type checking on or off based on the current working language. | |
7691 | @xref{Support, ,Supported languages}, for the default settings for | |
7692 | each language. | |
7693 | ||
7694 | @item set check type on | |
7695 | @itemx set check type off | |
7696 | Set type checking on or off, overriding the default setting for the | |
7697 | current working language. Issue a warning if the setting does not | |
7698 | match the language default. If any type mismatches occur in | |
d4f3574e | 7699 | evaluating an expression while type checking is on, @value{GDBN} prints a |
c906108c SS |
7700 | message and aborts evaluation of the expression. |
7701 | ||
7702 | @item set check type warn | |
7703 | Cause the type checker to issue warnings, but to always attempt to | |
7704 | evaluate the expression. Evaluating the expression may still | |
7705 | be impossible for other reasons. For example, @value{GDBN} cannot add | |
7706 | numbers and structures. | |
7707 | ||
7708 | @item show type | |
5d161b24 | 7709 | Show the current setting of the type checker, and whether or not @value{GDBN} |
c906108c SS |
7710 | is setting it automatically. |
7711 | @end table | |
7712 | ||
7713 | @cindex range checking | |
7714 | @cindex checks, range | |
6d2ebf8b | 7715 | @node Range Checking |
c906108c SS |
7716 | @subsection An overview of range checking |
7717 | ||
7718 | In some languages (such as Modula-2), it is an error to exceed the | |
7719 | bounds of a type; this is enforced with run-time checks. Such range | |
7720 | checking is meant to ensure program correctness by making sure | |
7721 | computations do not overflow, or indices on an array element access do | |
7722 | not exceed the bounds of the array. | |
7723 | ||
7724 | For expressions you use in @value{GDBN} commands, you can tell | |
7725 | @value{GDBN} to treat range errors in one of three ways: ignore them, | |
7726 | always treat them as errors and abandon the expression, or issue | |
7727 | warnings but evaluate the expression anyway. | |
7728 | ||
7729 | A range error can result from numerical overflow, from exceeding an | |
7730 | array index bound, or when you type a constant that is not a member | |
7731 | of any type. Some languages, however, do not treat overflows as an | |
7732 | error. In many implementations of C, mathematical overflow causes the | |
7733 | result to ``wrap around'' to lower values---for example, if @var{m} is | |
7734 | the largest integer value, and @var{s} is the smallest, then | |
7735 | ||
474c8240 | 7736 | @smallexample |
c906108c | 7737 | @var{m} + 1 @result{} @var{s} |
474c8240 | 7738 | @end smallexample |
c906108c SS |
7739 | |
7740 | This, too, is specific to individual languages, and in some cases | |
7741 | specific to individual compilers or machines. @xref{Support, , | |
7742 | Supported languages}, for further details on specific languages. | |
7743 | ||
7744 | @value{GDBN} provides some additional commands for controlling the range checker: | |
7745 | ||
d4f3574e | 7746 | @kindex set check@r{, range} |
c906108c SS |
7747 | @kindex set check range |
7748 | @kindex show check range | |
7749 | @table @code | |
7750 | @item set check range auto | |
7751 | Set range checking on or off based on the current working language. | |
7752 | @xref{Support, ,Supported languages}, for the default settings for | |
7753 | each language. | |
7754 | ||
7755 | @item set check range on | |
7756 | @itemx set check range off | |
7757 | Set range checking on or off, overriding the default setting for the | |
7758 | current working language. A warning is issued if the setting does not | |
c3f6f71d JM |
7759 | match the language default. If a range error occurs and range checking is on, |
7760 | then a message is printed and evaluation of the expression is aborted. | |
c906108c SS |
7761 | |
7762 | @item set check range warn | |
7763 | Output messages when the @value{GDBN} range checker detects a range error, | |
7764 | but attempt to evaluate the expression anyway. Evaluating the | |
7765 | expression may still be impossible for other reasons, such as accessing | |
7766 | memory that the process does not own (a typical example from many Unix | |
7767 | systems). | |
7768 | ||
7769 | @item show range | |
7770 | Show the current setting of the range checker, and whether or not it is | |
7771 | being set automatically by @value{GDBN}. | |
7772 | @end table | |
c906108c | 7773 | |
6d2ebf8b | 7774 | @node Support |
c906108c | 7775 | @section Supported languages |
c906108c | 7776 | |
e632838e | 7777 | @value{GDBN} supports C, C@t{++}, Fortran, Java, assembly, and Modula-2. |
cce74817 | 7778 | @c This is false ... |
c906108c SS |
7779 | Some @value{GDBN} features may be used in expressions regardless of the |
7780 | language you use: the @value{GDBN} @code{@@} and @code{::} operators, | |
7781 | and the @samp{@{type@}addr} construct (@pxref{Expressions, | |
7782 | ,Expressions}) can be used with the constructs of any supported | |
7783 | language. | |
7784 | ||
7785 | The following sections detail to what degree each source language is | |
7786 | supported by @value{GDBN}. These sections are not meant to be language | |
7787 | tutorials or references, but serve only as a reference guide to what the | |
7788 | @value{GDBN} expression parser accepts, and what input and output | |
7789 | formats should look like for different languages. There are many good | |
7790 | books written on each of these languages; please look to these for a | |
7791 | language reference or tutorial. | |
7792 | ||
c906108c | 7793 | @menu |
b37052ae | 7794 | * C:: C and C@t{++} |
cce74817 | 7795 | * Modula-2:: Modula-2 |
c906108c SS |
7796 | @end menu |
7797 | ||
6d2ebf8b | 7798 | @node C |
b37052ae | 7799 | @subsection C and C@t{++} |
7a292a7a | 7800 | |
b37052ae EZ |
7801 | @cindex C and C@t{++} |
7802 | @cindex expressions in C or C@t{++} | |
c906108c | 7803 | |
b37052ae | 7804 | Since C and C@t{++} are so closely related, many features of @value{GDBN} apply |
c906108c SS |
7805 | to both languages. Whenever this is the case, we discuss those languages |
7806 | together. | |
7807 | ||
41afff9a EZ |
7808 | @cindex C@t{++} |
7809 | @cindex @code{g++}, @sc{gnu} C@t{++} compiler | |
b37052ae EZ |
7810 | @cindex @sc{gnu} C@t{++} |
7811 | The C@t{++} debugging facilities are jointly implemented by the C@t{++} | |
7812 | compiler and @value{GDBN}. Therefore, to debug your C@t{++} code | |
7813 | effectively, you must compile your C@t{++} programs with a supported | |
7814 | C@t{++} compiler, such as @sc{gnu} @code{g++}, or the HP ANSI C@t{++} | |
c906108c SS |
7815 | compiler (@code{aCC}). |
7816 | ||
0179ffac DC |
7817 | For best results when using @sc{gnu} C@t{++}, use the DWARF 2 debugging |
7818 | format; if it doesn't work on your system, try the stabs+ debugging | |
7819 | format. You can select those formats explicitly with the @code{g++} | |
7820 | command-line options @option{-gdwarf-2} and @option{-gstabs+}. | |
7821 | @xref{Debugging Options,,Options for Debugging Your Program or @sc{gnu} | |
7822 | CC, gcc.info, Using @sc{gnu} CC}. | |
c906108c | 7823 | |
c906108c | 7824 | @menu |
b37052ae EZ |
7825 | * C Operators:: C and C@t{++} operators |
7826 | * C Constants:: C and C@t{++} constants | |
7827 | * C plus plus expressions:: C@t{++} expressions | |
7828 | * C Defaults:: Default settings for C and C@t{++} | |
7829 | * C Checks:: C and C@t{++} type and range checks | |
c906108c | 7830 | * Debugging C:: @value{GDBN} and C |
b37052ae | 7831 | * Debugging C plus plus:: @value{GDBN} features for C@t{++} |
c906108c | 7832 | @end menu |
c906108c | 7833 | |
6d2ebf8b | 7834 | @node C Operators |
b37052ae | 7835 | @subsubsection C and C@t{++} operators |
7a292a7a | 7836 | |
b37052ae | 7837 | @cindex C and C@t{++} operators |
c906108c SS |
7838 | |
7839 | Operators must be defined on values of specific types. For instance, | |
7840 | @code{+} is defined on numbers, but not on structures. Operators are | |
5d161b24 | 7841 | often defined on groups of types. |
c906108c | 7842 | |
b37052ae | 7843 | For the purposes of C and C@t{++}, the following definitions hold: |
c906108c SS |
7844 | |
7845 | @itemize @bullet | |
53a5351d | 7846 | |
c906108c | 7847 | @item |
c906108c | 7848 | @emph{Integral types} include @code{int} with any of its storage-class |
b37052ae | 7849 | specifiers; @code{char}; @code{enum}; and, for C@t{++}, @code{bool}. |
c906108c SS |
7850 | |
7851 | @item | |
d4f3574e SS |
7852 | @emph{Floating-point types} include @code{float}, @code{double}, and |
7853 | @code{long double} (if supported by the target platform). | |
c906108c SS |
7854 | |
7855 | @item | |
53a5351d | 7856 | @emph{Pointer types} include all types defined as @code{(@var{type} *)}. |
c906108c SS |
7857 | |
7858 | @item | |
7859 | @emph{Scalar types} include all of the above. | |
53a5351d | 7860 | |
c906108c SS |
7861 | @end itemize |
7862 | ||
7863 | @noindent | |
7864 | The following operators are supported. They are listed here | |
7865 | in order of increasing precedence: | |
7866 | ||
7867 | @table @code | |
7868 | @item , | |
7869 | The comma or sequencing operator. Expressions in a comma-separated list | |
7870 | are evaluated from left to right, with the result of the entire | |
7871 | expression being the last expression evaluated. | |
7872 | ||
7873 | @item = | |
7874 | Assignment. The value of an assignment expression is the value | |
7875 | assigned. Defined on scalar types. | |
7876 | ||
7877 | @item @var{op}= | |
7878 | Used in an expression of the form @w{@code{@var{a} @var{op}= @var{b}}}, | |
7879 | and translated to @w{@code{@var{a} = @var{a op b}}}. | |
d4f3574e | 7880 | @w{@code{@var{op}=}} and @code{=} have the same precedence. |
c906108c SS |
7881 | @var{op} is any one of the operators @code{|}, @code{^}, @code{&}, |
7882 | @code{<<}, @code{>>}, @code{+}, @code{-}, @code{*}, @code{/}, @code{%}. | |
7883 | ||
7884 | @item ?: | |
7885 | The ternary operator. @code{@var{a} ? @var{b} : @var{c}} can be thought | |
7886 | of as: if @var{a} then @var{b} else @var{c}. @var{a} should be of an | |
7887 | integral type. | |
7888 | ||
7889 | @item || | |
7890 | Logical @sc{or}. Defined on integral types. | |
7891 | ||
7892 | @item && | |
7893 | Logical @sc{and}. Defined on integral types. | |
7894 | ||
7895 | @item | | |
7896 | Bitwise @sc{or}. Defined on integral types. | |
7897 | ||
7898 | @item ^ | |
7899 | Bitwise exclusive-@sc{or}. Defined on integral types. | |
7900 | ||
7901 | @item & | |
7902 | Bitwise @sc{and}. Defined on integral types. | |
7903 | ||
7904 | @item ==@r{, }!= | |
7905 | Equality and inequality. Defined on scalar types. The value of these | |
7906 | expressions is 0 for false and non-zero for true. | |
7907 | ||
7908 | @item <@r{, }>@r{, }<=@r{, }>= | |
7909 | Less than, greater than, less than or equal, greater than or equal. | |
7910 | Defined on scalar types. The value of these expressions is 0 for false | |
7911 | and non-zero for true. | |
7912 | ||
7913 | @item <<@r{, }>> | |
7914 | left shift, and right shift. Defined on integral types. | |
7915 | ||
7916 | @item @@ | |
7917 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
7918 | ||
7919 | @item +@r{, }- | |
7920 | Addition and subtraction. Defined on integral types, floating-point types and | |
7921 | pointer types. | |
7922 | ||
7923 | @item *@r{, }/@r{, }% | |
7924 | Multiplication, division, and modulus. Multiplication and division are | |
7925 | defined on integral and floating-point types. Modulus is defined on | |
7926 | integral types. | |
7927 | ||
7928 | @item ++@r{, }-- | |
7929 | Increment and decrement. When appearing before a variable, the | |
7930 | operation is performed before the variable is used in an expression; | |
7931 | when appearing after it, the variable's value is used before the | |
7932 | operation takes place. | |
7933 | ||
7934 | @item * | |
7935 | Pointer dereferencing. Defined on pointer types. Same precedence as | |
7936 | @code{++}. | |
7937 | ||
7938 | @item & | |
7939 | Address operator. Defined on variables. Same precedence as @code{++}. | |
7940 | ||
b37052ae EZ |
7941 | For debugging C@t{++}, @value{GDBN} implements a use of @samp{&} beyond what is |
7942 | allowed in the C@t{++} language itself: you can use @samp{&(&@var{ref})} | |
c906108c | 7943 | (or, if you prefer, simply @samp{&&@var{ref}}) to examine the address |
b37052ae | 7944 | where a C@t{++} reference variable (declared with @samp{&@var{ref}}) is |
c906108c | 7945 | stored. |
c906108c SS |
7946 | |
7947 | @item - | |
7948 | Negative. Defined on integral and floating-point types. Same | |
7949 | precedence as @code{++}. | |
7950 | ||
7951 | @item ! | |
7952 | Logical negation. Defined on integral types. Same precedence as | |
7953 | @code{++}. | |
7954 | ||
7955 | @item ~ | |
7956 | Bitwise complement operator. Defined on integral types. Same precedence as | |
7957 | @code{++}. | |
7958 | ||
7959 | ||
7960 | @item .@r{, }-> | |
7961 | Structure member, and pointer-to-structure member. For convenience, | |
7962 | @value{GDBN} regards the two as equivalent, choosing whether to dereference a | |
7963 | pointer based on the stored type information. | |
7964 | Defined on @code{struct} and @code{union} data. | |
7965 | ||
c906108c SS |
7966 | @item .*@r{, }->* |
7967 | Dereferences of pointers to members. | |
c906108c SS |
7968 | |
7969 | @item [] | |
7970 | Array indexing. @code{@var{a}[@var{i}]} is defined as | |
7971 | @code{*(@var{a}+@var{i})}. Same precedence as @code{->}. | |
7972 | ||
7973 | @item () | |
7974 | Function parameter list. Same precedence as @code{->}. | |
7975 | ||
c906108c | 7976 | @item :: |
b37052ae | 7977 | C@t{++} scope resolution operator. Defined on @code{struct}, @code{union}, |
7a292a7a | 7978 | and @code{class} types. |
c906108c SS |
7979 | |
7980 | @item :: | |
7a292a7a SS |
7981 | Doubled colons also represent the @value{GDBN} scope operator |
7982 | (@pxref{Expressions, ,Expressions}). Same precedence as @code{::}, | |
7983 | above. | |
c906108c SS |
7984 | @end table |
7985 | ||
c906108c SS |
7986 | If an operator is redefined in the user code, @value{GDBN} usually |
7987 | attempts to invoke the redefined version instead of using the operator's | |
7988 | predefined meaning. | |
c906108c | 7989 | |
c906108c | 7990 | @menu |
5d161b24 | 7991 | * C Constants:: |
c906108c SS |
7992 | @end menu |
7993 | ||
6d2ebf8b | 7994 | @node C Constants |
b37052ae | 7995 | @subsubsection C and C@t{++} constants |
c906108c | 7996 | |
b37052ae | 7997 | @cindex C and C@t{++} constants |
c906108c | 7998 | |
b37052ae | 7999 | @value{GDBN} allows you to express the constants of C and C@t{++} in the |
c906108c | 8000 | following ways: |
c906108c SS |
8001 | |
8002 | @itemize @bullet | |
8003 | @item | |
8004 | Integer constants are a sequence of digits. Octal constants are | |
6ca652b0 EZ |
8005 | specified by a leading @samp{0} (i.e.@: zero), and hexadecimal constants |
8006 | by a leading @samp{0x} or @samp{0X}. Constants may also end with a letter | |
c906108c SS |
8007 | @samp{l}, specifying that the constant should be treated as a |
8008 | @code{long} value. | |
8009 | ||
8010 | @item | |
8011 | Floating point constants are a sequence of digits, followed by a decimal | |
8012 | point, followed by a sequence of digits, and optionally followed by an | |
8013 | exponent. An exponent is of the form: | |
8014 | @samp{@w{e@r{[[}+@r{]|}-@r{]}@var{nnn}}}, where @var{nnn} is another | |
8015 | sequence of digits. The @samp{+} is optional for positive exponents. | |
d4f3574e SS |
8016 | A floating-point constant may also end with a letter @samp{f} or |
8017 | @samp{F}, specifying that the constant should be treated as being of | |
8018 | the @code{float} (as opposed to the default @code{double}) type; or with | |
8019 | a letter @samp{l} or @samp{L}, which specifies a @code{long double} | |
8020 | constant. | |
c906108c SS |
8021 | |
8022 | @item | |
8023 | Enumerated constants consist of enumerated identifiers, or their | |
8024 | integral equivalents. | |
8025 | ||
8026 | @item | |
8027 | Character constants are a single character surrounded by single quotes | |
8028 | (@code{'}), or a number---the ordinal value of the corresponding character | |
d4f3574e | 8029 | (usually its @sc{ascii} value). Within quotes, the single character may |
c906108c SS |
8030 | be represented by a letter or by @dfn{escape sequences}, which are of |
8031 | the form @samp{\@var{nnn}}, where @var{nnn} is the octal representation | |
8032 | of the character's ordinal value; or of the form @samp{\@var{x}}, where | |
8033 | @samp{@var{x}} is a predefined special character---for example, | |
8034 | @samp{\n} for newline. | |
8035 | ||
8036 | @item | |
96a2c332 SS |
8037 | String constants are a sequence of character constants surrounded by |
8038 | double quotes (@code{"}). Any valid character constant (as described | |
8039 | above) may appear. Double quotes within the string must be preceded by | |
8040 | a backslash, so for instance @samp{"a\"b'c"} is a string of five | |
8041 | characters. | |
c906108c SS |
8042 | |
8043 | @item | |
8044 | Pointer constants are an integral value. You can also write pointers | |
8045 | to constants using the C operator @samp{&}. | |
8046 | ||
8047 | @item | |
8048 | Array constants are comma-separated lists surrounded by braces @samp{@{} | |
8049 | and @samp{@}}; for example, @samp{@{1,2,3@}} is a three-element array of | |
8050 | integers, @samp{@{@{1,2@}, @{3,4@}, @{5,6@}@}} is a three-by-two array, | |
8051 | and @samp{@{&"hi", &"there", &"fred"@}} is a three-element array of pointers. | |
8052 | @end itemize | |
8053 | ||
c906108c | 8054 | @menu |
5d161b24 DB |
8055 | * C plus plus expressions:: |
8056 | * C Defaults:: | |
8057 | * C Checks:: | |
c906108c | 8058 | |
5d161b24 | 8059 | * Debugging C:: |
c906108c SS |
8060 | @end menu |
8061 | ||
6d2ebf8b | 8062 | @node C plus plus expressions |
b37052ae EZ |
8063 | @subsubsection C@t{++} expressions |
8064 | ||
8065 | @cindex expressions in C@t{++} | |
8066 | @value{GDBN} expression handling can interpret most C@t{++} expressions. | |
8067 | ||
0179ffac DC |
8068 | @cindex debugging C@t{++} programs |
8069 | @cindex C@t{++} compilers | |
8070 | @cindex debug formats and C@t{++} | |
8071 | @cindex @value{NGCC} and C@t{++} | |
c906108c | 8072 | @quotation |
b37052ae | 8073 | @emph{Warning:} @value{GDBN} can only debug C@t{++} code if you use the |
0179ffac DC |
8074 | proper compiler and the proper debug format. Currently, @value{GDBN} |
8075 | works best when debugging C@t{++} code that is compiled with | |
8076 | @value{NGCC} 2.95.3 or with @value{NGCC} 3.1 or newer, using the options | |
8077 | @option{-gdwarf-2} or @option{-gstabs+}. DWARF 2 is preferred over | |
8078 | stabs+. Most configurations of @value{NGCC} emit either DWARF 2 or | |
8079 | stabs+ as their default debug format, so you usually don't need to | |
8080 | specify a debug format explicitly. Other compilers and/or debug formats | |
8081 | are likely to work badly or not at all when using @value{GDBN} to debug | |
8082 | C@t{++} code. | |
c906108c | 8083 | @end quotation |
c906108c SS |
8084 | |
8085 | @enumerate | |
8086 | ||
8087 | @cindex member functions | |
8088 | @item | |
8089 | Member function calls are allowed; you can use expressions like | |
8090 | ||
474c8240 | 8091 | @smallexample |
c906108c | 8092 | count = aml->GetOriginal(x, y) |
474c8240 | 8093 | @end smallexample |
c906108c | 8094 | |
41afff9a | 8095 | @vindex this@r{, inside C@t{++} member functions} |
b37052ae | 8096 | @cindex namespace in C@t{++} |
c906108c SS |
8097 | @item |
8098 | While a member function is active (in the selected stack frame), your | |
8099 | expressions have the same namespace available as the member function; | |
8100 | that is, @value{GDBN} allows implicit references to the class instance | |
b37052ae | 8101 | pointer @code{this} following the same rules as C@t{++}. |
c906108c | 8102 | |
c906108c | 8103 | @cindex call overloaded functions |
d4f3574e | 8104 | @cindex overloaded functions, calling |
b37052ae | 8105 | @cindex type conversions in C@t{++} |
c906108c SS |
8106 | @item |
8107 | You can call overloaded functions; @value{GDBN} resolves the function | |
d4f3574e | 8108 | call to the right definition, with some restrictions. @value{GDBN} does not |
c906108c SS |
8109 | perform overload resolution involving user-defined type conversions, |
8110 | calls to constructors, or instantiations of templates that do not exist | |
8111 | in the program. It also cannot handle ellipsis argument lists or | |
8112 | default arguments. | |
8113 | ||
8114 | It does perform integral conversions and promotions, floating-point | |
8115 | promotions, arithmetic conversions, pointer conversions, conversions of | |
8116 | class objects to base classes, and standard conversions such as those of | |
8117 | functions or arrays to pointers; it requires an exact match on the | |
8118 | number of function arguments. | |
8119 | ||
8120 | Overload resolution is always performed, unless you have specified | |
8121 | @code{set overload-resolution off}. @xref{Debugging C plus plus, | |
b37052ae | 8122 | ,@value{GDBN} features for C@t{++}}. |
c906108c | 8123 | |
d4f3574e | 8124 | You must specify @code{set overload-resolution off} in order to use an |
c906108c SS |
8125 | explicit function signature to call an overloaded function, as in |
8126 | @smallexample | |
8127 | p 'foo(char,int)'('x', 13) | |
8128 | @end smallexample | |
d4f3574e | 8129 | |
c906108c | 8130 | The @value{GDBN} command-completion facility can simplify this; |
d4f3574e | 8131 | see @ref{Completion, ,Command completion}. |
c906108c | 8132 | |
c906108c SS |
8133 | @cindex reference declarations |
8134 | @item | |
b37052ae EZ |
8135 | @value{GDBN} understands variables declared as C@t{++} references; you can use |
8136 | them in expressions just as you do in C@t{++} source---they are automatically | |
c906108c SS |
8137 | dereferenced. |
8138 | ||
8139 | In the parameter list shown when @value{GDBN} displays a frame, the values of | |
8140 | reference variables are not displayed (unlike other variables); this | |
8141 | avoids clutter, since references are often used for large structures. | |
8142 | The @emph{address} of a reference variable is always shown, unless | |
8143 | you have specified @samp{set print address off}. | |
8144 | ||
8145 | @item | |
b37052ae | 8146 | @value{GDBN} supports the C@t{++} name resolution operator @code{::}---your |
c906108c SS |
8147 | expressions can use it just as expressions in your program do. Since |
8148 | one scope may be defined in another, you can use @code{::} repeatedly if | |
8149 | necessary, for example in an expression like | |
8150 | @samp{@var{scope1}::@var{scope2}::@var{name}}. @value{GDBN} also allows | |
b37052ae | 8151 | resolving name scope by reference to source files, in both C and C@t{++} |
c906108c SS |
8152 | debugging (@pxref{Variables, ,Program variables}). |
8153 | @end enumerate | |
8154 | ||
b37052ae | 8155 | In addition, when used with HP's C@t{++} compiler, @value{GDBN} supports |
53a5351d JM |
8156 | calling virtual functions correctly, printing out virtual bases of |
8157 | objects, calling functions in a base subobject, casting objects, and | |
8158 | invoking user-defined operators. | |
c906108c | 8159 | |
6d2ebf8b | 8160 | @node C Defaults |
b37052ae | 8161 | @subsubsection C and C@t{++} defaults |
7a292a7a | 8162 | |
b37052ae | 8163 | @cindex C and C@t{++} defaults |
c906108c | 8164 | |
c906108c SS |
8165 | If you allow @value{GDBN} to set type and range checking automatically, they |
8166 | both default to @code{off} whenever the working language changes to | |
b37052ae | 8167 | C or C@t{++}. This happens regardless of whether you or @value{GDBN} |
c906108c | 8168 | selects the working language. |
c906108c SS |
8169 | |
8170 | If you allow @value{GDBN} to set the language automatically, it | |
8171 | recognizes source files whose names end with @file{.c}, @file{.C}, or | |
8172 | @file{.cc}, etc, and when @value{GDBN} enters code compiled from one of | |
b37052ae | 8173 | these files, it sets the working language to C or C@t{++}. |
c906108c SS |
8174 | @xref{Automatically, ,Having @value{GDBN} infer the source language}, |
8175 | for further details. | |
8176 | ||
c906108c SS |
8177 | @c Type checking is (a) primarily motivated by Modula-2, and (b) |
8178 | @c unimplemented. If (b) changes, it might make sense to let this node | |
8179 | @c appear even if Mod-2 does not, but meanwhile ignore it. roland 16jul93. | |
7a292a7a | 8180 | |
6d2ebf8b | 8181 | @node C Checks |
b37052ae | 8182 | @subsubsection C and C@t{++} type and range checks |
7a292a7a | 8183 | |
b37052ae | 8184 | @cindex C and C@t{++} checks |
c906108c | 8185 | |
b37052ae | 8186 | By default, when @value{GDBN} parses C or C@t{++} expressions, type checking |
c906108c SS |
8187 | is not used. However, if you turn type checking on, @value{GDBN} |
8188 | considers two variables type equivalent if: | |
8189 | ||
8190 | @itemize @bullet | |
8191 | @item | |
8192 | The two variables are structured and have the same structure, union, or | |
8193 | enumerated tag. | |
8194 | ||
8195 | @item | |
8196 | The two variables have the same type name, or types that have been | |
8197 | declared equivalent through @code{typedef}. | |
8198 | ||
8199 | @ignore | |
8200 | @c leaving this out because neither J Gilmore nor R Pesch understand it. | |
8201 | @c FIXME--beers? | |
8202 | @item | |
8203 | The two @code{struct}, @code{union}, or @code{enum} variables are | |
8204 | declared in the same declaration. (Note: this may not be true for all C | |
8205 | compilers.) | |
8206 | @end ignore | |
8207 | @end itemize | |
8208 | ||
8209 | Range checking, if turned on, is done on mathematical operations. Array | |
8210 | indices are not checked, since they are often used to index a pointer | |
8211 | that is not itself an array. | |
c906108c | 8212 | |
6d2ebf8b | 8213 | @node Debugging C |
c906108c | 8214 | @subsubsection @value{GDBN} and C |
c906108c SS |
8215 | |
8216 | The @code{set print union} and @code{show print union} commands apply to | |
8217 | the @code{union} type. When set to @samp{on}, any @code{union} that is | |
7a292a7a SS |
8218 | inside a @code{struct} or @code{class} is also printed. Otherwise, it |
8219 | appears as @samp{@{...@}}. | |
c906108c SS |
8220 | |
8221 | The @code{@@} operator aids in the debugging of dynamic arrays, formed | |
8222 | with pointers and a memory allocation function. @xref{Expressions, | |
8223 | ,Expressions}. | |
8224 | ||
c906108c | 8225 | @menu |
5d161b24 | 8226 | * Debugging C plus plus:: |
c906108c SS |
8227 | @end menu |
8228 | ||
6d2ebf8b | 8229 | @node Debugging C plus plus |
b37052ae | 8230 | @subsubsection @value{GDBN} features for C@t{++} |
c906108c | 8231 | |
b37052ae | 8232 | @cindex commands for C@t{++} |
7a292a7a | 8233 | |
b37052ae EZ |
8234 | Some @value{GDBN} commands are particularly useful with C@t{++}, and some are |
8235 | designed specifically for use with C@t{++}. Here is a summary: | |
c906108c SS |
8236 | |
8237 | @table @code | |
8238 | @cindex break in overloaded functions | |
8239 | @item @r{breakpoint menus} | |
8240 | When you want a breakpoint in a function whose name is overloaded, | |
8241 | @value{GDBN} breakpoint menus help you specify which function definition | |
8242 | you want. @xref{Breakpoint Menus,,Breakpoint menus}. | |
8243 | ||
b37052ae | 8244 | @cindex overloading in C@t{++} |
c906108c SS |
8245 | @item rbreak @var{regex} |
8246 | Setting breakpoints using regular expressions is helpful for setting | |
8247 | breakpoints on overloaded functions that are not members of any special | |
8248 | classes. | |
8249 | @xref{Set Breaks, ,Setting breakpoints}. | |
8250 | ||
b37052ae | 8251 | @cindex C@t{++} exception handling |
c906108c SS |
8252 | @item catch throw |
8253 | @itemx catch catch | |
b37052ae | 8254 | Debug C@t{++} exception handling using these commands. @xref{Set |
c906108c SS |
8255 | Catchpoints, , Setting catchpoints}. |
8256 | ||
8257 | @cindex inheritance | |
8258 | @item ptype @var{typename} | |
8259 | Print inheritance relationships as well as other information for type | |
8260 | @var{typename}. | |
8261 | @xref{Symbols, ,Examining the Symbol Table}. | |
8262 | ||
b37052ae | 8263 | @cindex C@t{++} symbol display |
c906108c SS |
8264 | @item set print demangle |
8265 | @itemx show print demangle | |
8266 | @itemx set print asm-demangle | |
8267 | @itemx show print asm-demangle | |
b37052ae EZ |
8268 | Control whether C@t{++} symbols display in their source form, both when |
8269 | displaying code as C@t{++} source and when displaying disassemblies. | |
c906108c SS |
8270 | @xref{Print Settings, ,Print settings}. |
8271 | ||
8272 | @item set print object | |
8273 | @itemx show print object | |
8274 | Choose whether to print derived (actual) or declared types of objects. | |
8275 | @xref{Print Settings, ,Print settings}. | |
8276 | ||
8277 | @item set print vtbl | |
8278 | @itemx show print vtbl | |
8279 | Control the format for printing virtual function tables. | |
8280 | @xref{Print Settings, ,Print settings}. | |
c906108c | 8281 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 8282 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
8283 | |
8284 | @kindex set overload-resolution | |
d4f3574e | 8285 | @cindex overloaded functions, overload resolution |
c906108c | 8286 | @item set overload-resolution on |
b37052ae | 8287 | Enable overload resolution for C@t{++} expression evaluation. The default |
c906108c SS |
8288 | is on. For overloaded functions, @value{GDBN} evaluates the arguments |
8289 | and searches for a function whose signature matches the argument types, | |
b37052ae | 8290 | using the standard C@t{++} conversion rules (see @ref{C plus plus expressions, ,C@t{++} |
d4f3574e | 8291 | expressions}, for details). If it cannot find a match, it emits a |
c906108c SS |
8292 | message. |
8293 | ||
8294 | @item set overload-resolution off | |
b37052ae | 8295 | Disable overload resolution for C@t{++} expression evaluation. For |
c906108c SS |
8296 | overloaded functions that are not class member functions, @value{GDBN} |
8297 | chooses the first function of the specified name that it finds in the | |
8298 | symbol table, whether or not its arguments are of the correct type. For | |
8299 | overloaded functions that are class member functions, @value{GDBN} | |
8300 | searches for a function whose signature @emph{exactly} matches the | |
8301 | argument types. | |
c906108c SS |
8302 | |
8303 | @item @r{Overloaded symbol names} | |
8304 | You can specify a particular definition of an overloaded symbol, using | |
b37052ae | 8305 | the same notation that is used to declare such symbols in C@t{++}: type |
c906108c SS |
8306 | @code{@var{symbol}(@var{types})} rather than just @var{symbol}. You can |
8307 | also use the @value{GDBN} command-line word completion facilities to list the | |
8308 | available choices, or to finish the type list for you. | |
8309 | @xref{Completion,, Command completion}, for details on how to do this. | |
8310 | @end table | |
c906108c | 8311 | |
6d2ebf8b | 8312 | @node Modula-2 |
c906108c | 8313 | @subsection Modula-2 |
7a292a7a | 8314 | |
d4f3574e | 8315 | @cindex Modula-2, @value{GDBN} support |
c906108c SS |
8316 | |
8317 | The extensions made to @value{GDBN} to support Modula-2 only support | |
8318 | output from the @sc{gnu} Modula-2 compiler (which is currently being | |
8319 | developed). Other Modula-2 compilers are not currently supported, and | |
8320 | attempting to debug executables produced by them is most likely | |
8321 | to give an error as @value{GDBN} reads in the executable's symbol | |
8322 | table. | |
8323 | ||
8324 | @cindex expressions in Modula-2 | |
8325 | @menu | |
8326 | * M2 Operators:: Built-in operators | |
8327 | * Built-In Func/Proc:: Built-in functions and procedures | |
8328 | * M2 Constants:: Modula-2 constants | |
8329 | * M2 Defaults:: Default settings for Modula-2 | |
8330 | * Deviations:: Deviations from standard Modula-2 | |
8331 | * M2 Checks:: Modula-2 type and range checks | |
8332 | * M2 Scope:: The scope operators @code{::} and @code{.} | |
8333 | * GDB/M2:: @value{GDBN} and Modula-2 | |
8334 | @end menu | |
8335 | ||
6d2ebf8b | 8336 | @node M2 Operators |
c906108c SS |
8337 | @subsubsection Operators |
8338 | @cindex Modula-2 operators | |
8339 | ||
8340 | Operators must be defined on values of specific types. For instance, | |
8341 | @code{+} is defined on numbers, but not on structures. Operators are | |
8342 | often defined on groups of types. For the purposes of Modula-2, the | |
8343 | following definitions hold: | |
8344 | ||
8345 | @itemize @bullet | |
8346 | ||
8347 | @item | |
8348 | @emph{Integral types} consist of @code{INTEGER}, @code{CARDINAL}, and | |
8349 | their subranges. | |
8350 | ||
8351 | @item | |
8352 | @emph{Character types} consist of @code{CHAR} and its subranges. | |
8353 | ||
8354 | @item | |
8355 | @emph{Floating-point types} consist of @code{REAL}. | |
8356 | ||
8357 | @item | |
8358 | @emph{Pointer types} consist of anything declared as @code{POINTER TO | |
8359 | @var{type}}. | |
8360 | ||
8361 | @item | |
8362 | @emph{Scalar types} consist of all of the above. | |
8363 | ||
8364 | @item | |
8365 | @emph{Set types} consist of @code{SET} and @code{BITSET} types. | |
8366 | ||
8367 | @item | |
8368 | @emph{Boolean types} consist of @code{BOOLEAN}. | |
8369 | @end itemize | |
8370 | ||
8371 | @noindent | |
8372 | The following operators are supported, and appear in order of | |
8373 | increasing precedence: | |
8374 | ||
8375 | @table @code | |
8376 | @item , | |
8377 | Function argument or array index separator. | |
8378 | ||
8379 | @item := | |
8380 | Assignment. The value of @var{var} @code{:=} @var{value} is | |
8381 | @var{value}. | |
8382 | ||
8383 | @item <@r{, }> | |
8384 | Less than, greater than on integral, floating-point, or enumerated | |
8385 | types. | |
8386 | ||
8387 | @item <=@r{, }>= | |
96a2c332 | 8388 | Less than or equal to, greater than or equal to |
c906108c SS |
8389 | on integral, floating-point and enumerated types, or set inclusion on |
8390 | set types. Same precedence as @code{<}. | |
8391 | ||
8392 | @item =@r{, }<>@r{, }# | |
8393 | Equality and two ways of expressing inequality, valid on scalar types. | |
8394 | Same precedence as @code{<}. In @value{GDBN} scripts, only @code{<>} is | |
8395 | available for inequality, since @code{#} conflicts with the script | |
8396 | comment character. | |
8397 | ||
8398 | @item IN | |
8399 | Set membership. Defined on set types and the types of their members. | |
8400 | Same precedence as @code{<}. | |
8401 | ||
8402 | @item OR | |
8403 | Boolean disjunction. Defined on boolean types. | |
8404 | ||
8405 | @item AND@r{, }& | |
d4f3574e | 8406 | Boolean conjunction. Defined on boolean types. |
c906108c SS |
8407 | |
8408 | @item @@ | |
8409 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
8410 | ||
8411 | @item +@r{, }- | |
8412 | Addition and subtraction on integral and floating-point types, or union | |
8413 | and difference on set types. | |
8414 | ||
8415 | @item * | |
8416 | Multiplication on integral and floating-point types, or set intersection | |
8417 | on set types. | |
8418 | ||
8419 | @item / | |
8420 | Division on floating-point types, or symmetric set difference on set | |
8421 | types. Same precedence as @code{*}. | |
8422 | ||
8423 | @item DIV@r{, }MOD | |
8424 | Integer division and remainder. Defined on integral types. Same | |
8425 | precedence as @code{*}. | |
8426 | ||
8427 | @item - | |
8428 | Negative. Defined on @code{INTEGER} and @code{REAL} data. | |
8429 | ||
8430 | @item ^ | |
8431 | Pointer dereferencing. Defined on pointer types. | |
8432 | ||
8433 | @item NOT | |
8434 | Boolean negation. Defined on boolean types. Same precedence as | |
8435 | @code{^}. | |
8436 | ||
8437 | @item . | |
8438 | @code{RECORD} field selector. Defined on @code{RECORD} data. Same | |
8439 | precedence as @code{^}. | |
8440 | ||
8441 | @item [] | |
8442 | Array indexing. Defined on @code{ARRAY} data. Same precedence as @code{^}. | |
8443 | ||
8444 | @item () | |
8445 | Procedure argument list. Defined on @code{PROCEDURE} objects. Same precedence | |
8446 | as @code{^}. | |
8447 | ||
8448 | @item ::@r{, }. | |
8449 | @value{GDBN} and Modula-2 scope operators. | |
8450 | @end table | |
8451 | ||
8452 | @quotation | |
8453 | @emph{Warning:} Sets and their operations are not yet supported, so @value{GDBN} | |
8454 | treats the use of the operator @code{IN}, or the use of operators | |
8455 | @code{+}, @code{-}, @code{*}, @code{/}, @code{=}, , @code{<>}, @code{#}, | |
8456 | @code{<=}, and @code{>=} on sets as an error. | |
8457 | @end quotation | |
8458 | ||
cb51c4e0 | 8459 | |
6d2ebf8b | 8460 | @node Built-In Func/Proc |
c906108c | 8461 | @subsubsection Built-in functions and procedures |
cb51c4e0 | 8462 | @cindex Modula-2 built-ins |
c906108c SS |
8463 | |
8464 | Modula-2 also makes available several built-in procedures and functions. | |
8465 | In describing these, the following metavariables are used: | |
8466 | ||
8467 | @table @var | |
8468 | ||
8469 | @item a | |
8470 | represents an @code{ARRAY} variable. | |
8471 | ||
8472 | @item c | |
8473 | represents a @code{CHAR} constant or variable. | |
8474 | ||
8475 | @item i | |
8476 | represents a variable or constant of integral type. | |
8477 | ||
8478 | @item m | |
8479 | represents an identifier that belongs to a set. Generally used in the | |
8480 | same function with the metavariable @var{s}. The type of @var{s} should | |
8481 | be @code{SET OF @var{mtype}} (where @var{mtype} is the type of @var{m}). | |
8482 | ||
8483 | @item n | |
8484 | represents a variable or constant of integral or floating-point type. | |
8485 | ||
8486 | @item r | |
8487 | represents a variable or constant of floating-point type. | |
8488 | ||
8489 | @item t | |
8490 | represents a type. | |
8491 | ||
8492 | @item v | |
8493 | represents a variable. | |
8494 | ||
8495 | @item x | |
8496 | represents a variable or constant of one of many types. See the | |
8497 | explanation of the function for details. | |
8498 | @end table | |
8499 | ||
8500 | All Modula-2 built-in procedures also return a result, described below. | |
8501 | ||
8502 | @table @code | |
8503 | @item ABS(@var{n}) | |
8504 | Returns the absolute value of @var{n}. | |
8505 | ||
8506 | @item CAP(@var{c}) | |
8507 | If @var{c} is a lower case letter, it returns its upper case | |
c3f6f71d | 8508 | equivalent, otherwise it returns its argument. |
c906108c SS |
8509 | |
8510 | @item CHR(@var{i}) | |
8511 | Returns the character whose ordinal value is @var{i}. | |
8512 | ||
8513 | @item DEC(@var{v}) | |
c3f6f71d | 8514 | Decrements the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
8515 | |
8516 | @item DEC(@var{v},@var{i}) | |
8517 | Decrements the value in the variable @var{v} by @var{i}. Returns the | |
8518 | new value. | |
8519 | ||
8520 | @item EXCL(@var{m},@var{s}) | |
8521 | Removes the element @var{m} from the set @var{s}. Returns the new | |
8522 | set. | |
8523 | ||
8524 | @item FLOAT(@var{i}) | |
8525 | Returns the floating point equivalent of the integer @var{i}. | |
8526 | ||
8527 | @item HIGH(@var{a}) | |
8528 | Returns the index of the last member of @var{a}. | |
8529 | ||
8530 | @item INC(@var{v}) | |
c3f6f71d | 8531 | Increments the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
8532 | |
8533 | @item INC(@var{v},@var{i}) | |
8534 | Increments the value in the variable @var{v} by @var{i}. Returns the | |
8535 | new value. | |
8536 | ||
8537 | @item INCL(@var{m},@var{s}) | |
8538 | Adds the element @var{m} to the set @var{s} if it is not already | |
8539 | there. Returns the new set. | |
8540 | ||
8541 | @item MAX(@var{t}) | |
8542 | Returns the maximum value of the type @var{t}. | |
8543 | ||
8544 | @item MIN(@var{t}) | |
8545 | Returns the minimum value of the type @var{t}. | |
8546 | ||
8547 | @item ODD(@var{i}) | |
8548 | Returns boolean TRUE if @var{i} is an odd number. | |
8549 | ||
8550 | @item ORD(@var{x}) | |
8551 | Returns the ordinal value of its argument. For example, the ordinal | |
c3f6f71d JM |
8552 | value of a character is its @sc{ascii} value (on machines supporting the |
8553 | @sc{ascii} character set). @var{x} must be of an ordered type, which include | |
c906108c SS |
8554 | integral, character and enumerated types. |
8555 | ||
8556 | @item SIZE(@var{x}) | |
8557 | Returns the size of its argument. @var{x} can be a variable or a type. | |
8558 | ||
8559 | @item TRUNC(@var{r}) | |
8560 | Returns the integral part of @var{r}. | |
8561 | ||
8562 | @item VAL(@var{t},@var{i}) | |
8563 | Returns the member of the type @var{t} whose ordinal value is @var{i}. | |
8564 | @end table | |
8565 | ||
8566 | @quotation | |
8567 | @emph{Warning:} Sets and their operations are not yet supported, so | |
8568 | @value{GDBN} treats the use of procedures @code{INCL} and @code{EXCL} as | |
8569 | an error. | |
8570 | @end quotation | |
8571 | ||
8572 | @cindex Modula-2 constants | |
6d2ebf8b | 8573 | @node M2 Constants |
c906108c SS |
8574 | @subsubsection Constants |
8575 | ||
8576 | @value{GDBN} allows you to express the constants of Modula-2 in the following | |
8577 | ways: | |
8578 | ||
8579 | @itemize @bullet | |
8580 | ||
8581 | @item | |
8582 | Integer constants are simply a sequence of digits. When used in an | |
8583 | expression, a constant is interpreted to be type-compatible with the | |
8584 | rest of the expression. Hexadecimal integers are specified by a | |
8585 | trailing @samp{H}, and octal integers by a trailing @samp{B}. | |
8586 | ||
8587 | @item | |
8588 | Floating point constants appear as a sequence of digits, followed by a | |
8589 | decimal point and another sequence of digits. An optional exponent can | |
8590 | then be specified, in the form @samp{E@r{[}+@r{|}-@r{]}@var{nnn}}, where | |
8591 | @samp{@r{[}+@r{|}-@r{]}@var{nnn}} is the desired exponent. All of the | |
8592 | digits of the floating point constant must be valid decimal (base 10) | |
8593 | digits. | |
8594 | ||
8595 | @item | |
8596 | Character constants consist of a single character enclosed by a pair of | |
8597 | like quotes, either single (@code{'}) or double (@code{"}). They may | |
c3f6f71d | 8598 | also be expressed by their ordinal value (their @sc{ascii} value, usually) |
c906108c SS |
8599 | followed by a @samp{C}. |
8600 | ||
8601 | @item | |
8602 | String constants consist of a sequence of characters enclosed by a | |
8603 | pair of like quotes, either single (@code{'}) or double (@code{"}). | |
8604 | Escape sequences in the style of C are also allowed. @xref{C | |
b37052ae | 8605 | Constants, ,C and C@t{++} constants}, for a brief explanation of escape |
c906108c SS |
8606 | sequences. |
8607 | ||
8608 | @item | |
8609 | Enumerated constants consist of an enumerated identifier. | |
8610 | ||
8611 | @item | |
8612 | Boolean constants consist of the identifiers @code{TRUE} and | |
8613 | @code{FALSE}. | |
8614 | ||
8615 | @item | |
8616 | Pointer constants consist of integral values only. | |
8617 | ||
8618 | @item | |
8619 | Set constants are not yet supported. | |
8620 | @end itemize | |
8621 | ||
6d2ebf8b | 8622 | @node M2 Defaults |
c906108c SS |
8623 | @subsubsection Modula-2 defaults |
8624 | @cindex Modula-2 defaults | |
8625 | ||
8626 | If type and range checking are set automatically by @value{GDBN}, they | |
8627 | both default to @code{on} whenever the working language changes to | |
d4f3574e | 8628 | Modula-2. This happens regardless of whether you or @value{GDBN} |
c906108c SS |
8629 | selected the working language. |
8630 | ||
8631 | If you allow @value{GDBN} to set the language automatically, then entering | |
8632 | code compiled from a file whose name ends with @file{.mod} sets the | |
d4f3574e | 8633 | working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} set |
c906108c SS |
8634 | the language automatically}, for further details. |
8635 | ||
6d2ebf8b | 8636 | @node Deviations |
c906108c SS |
8637 | @subsubsection Deviations from standard Modula-2 |
8638 | @cindex Modula-2, deviations from | |
8639 | ||
8640 | A few changes have been made to make Modula-2 programs easier to debug. | |
8641 | This is done primarily via loosening its type strictness: | |
8642 | ||
8643 | @itemize @bullet | |
8644 | @item | |
8645 | Unlike in standard Modula-2, pointer constants can be formed by | |
8646 | integers. This allows you to modify pointer variables during | |
8647 | debugging. (In standard Modula-2, the actual address contained in a | |
8648 | pointer variable is hidden from you; it can only be modified | |
8649 | through direct assignment to another pointer variable or expression that | |
8650 | returned a pointer.) | |
8651 | ||
8652 | @item | |
8653 | C escape sequences can be used in strings and characters to represent | |
8654 | non-printable characters. @value{GDBN} prints out strings with these | |
8655 | escape sequences embedded. Single non-printable characters are | |
8656 | printed using the @samp{CHR(@var{nnn})} format. | |
8657 | ||
8658 | @item | |
8659 | The assignment operator (@code{:=}) returns the value of its right-hand | |
8660 | argument. | |
8661 | ||
8662 | @item | |
8663 | All built-in procedures both modify @emph{and} return their argument. | |
8664 | @end itemize | |
8665 | ||
6d2ebf8b | 8666 | @node M2 Checks |
c906108c SS |
8667 | @subsubsection Modula-2 type and range checks |
8668 | @cindex Modula-2 checks | |
8669 | ||
8670 | @quotation | |
8671 | @emph{Warning:} in this release, @value{GDBN} does not yet perform type or | |
8672 | range checking. | |
8673 | @end quotation | |
8674 | @c FIXME remove warning when type/range checks added | |
8675 | ||
8676 | @value{GDBN} considers two Modula-2 variables type equivalent if: | |
8677 | ||
8678 | @itemize @bullet | |
8679 | @item | |
8680 | They are of types that have been declared equivalent via a @code{TYPE | |
8681 | @var{t1} = @var{t2}} statement | |
8682 | ||
8683 | @item | |
8684 | They have been declared on the same line. (Note: This is true of the | |
8685 | @sc{gnu} Modula-2 compiler, but it may not be true of other compilers.) | |
8686 | @end itemize | |
8687 | ||
8688 | As long as type checking is enabled, any attempt to combine variables | |
8689 | whose types are not equivalent is an error. | |
8690 | ||
8691 | Range checking is done on all mathematical operations, assignment, array | |
8692 | index bounds, and all built-in functions and procedures. | |
8693 | ||
6d2ebf8b | 8694 | @node M2 Scope |
c906108c SS |
8695 | @subsubsection The scope operators @code{::} and @code{.} |
8696 | @cindex scope | |
41afff9a | 8697 | @cindex @code{.}, Modula-2 scope operator |
c906108c SS |
8698 | @cindex colon, doubled as scope operator |
8699 | @ifinfo | |
41afff9a | 8700 | @vindex colon-colon@r{, in Modula-2} |
c906108c SS |
8701 | @c Info cannot handle :: but TeX can. |
8702 | @end ifinfo | |
8703 | @iftex | |
41afff9a | 8704 | @vindex ::@r{, in Modula-2} |
c906108c SS |
8705 | @end iftex |
8706 | ||
8707 | There are a few subtle differences between the Modula-2 scope operator | |
8708 | (@code{.}) and the @value{GDBN} scope operator (@code{::}). The two have | |
8709 | similar syntax: | |
8710 | ||
474c8240 | 8711 | @smallexample |
c906108c SS |
8712 | |
8713 | @var{module} . @var{id} | |
8714 | @var{scope} :: @var{id} | |
474c8240 | 8715 | @end smallexample |
c906108c SS |
8716 | |
8717 | @noindent | |
8718 | where @var{scope} is the name of a module or a procedure, | |
8719 | @var{module} the name of a module, and @var{id} is any declared | |
8720 | identifier within your program, except another module. | |
8721 | ||
8722 | Using the @code{::} operator makes @value{GDBN} search the scope | |
8723 | specified by @var{scope} for the identifier @var{id}. If it is not | |
8724 | found in the specified scope, then @value{GDBN} searches all scopes | |
8725 | enclosing the one specified by @var{scope}. | |
8726 | ||
8727 | Using the @code{.} operator makes @value{GDBN} search the current scope for | |
8728 | the identifier specified by @var{id} that was imported from the | |
8729 | definition module specified by @var{module}. With this operator, it is | |
8730 | an error if the identifier @var{id} was not imported from definition | |
8731 | module @var{module}, or if @var{id} is not an identifier in | |
8732 | @var{module}. | |
8733 | ||
6d2ebf8b | 8734 | @node GDB/M2 |
c906108c SS |
8735 | @subsubsection @value{GDBN} and Modula-2 |
8736 | ||
8737 | Some @value{GDBN} commands have little use when debugging Modula-2 programs. | |
8738 | Five subcommands of @code{set print} and @code{show print} apply | |
b37052ae | 8739 | specifically to C and C@t{++}: @samp{vtbl}, @samp{demangle}, |
c906108c | 8740 | @samp{asm-demangle}, @samp{object}, and @samp{union}. The first four |
b37052ae | 8741 | apply to C@t{++}, and the last to the C @code{union} type, which has no direct |
c906108c SS |
8742 | analogue in Modula-2. |
8743 | ||
8744 | The @code{@@} operator (@pxref{Expressions, ,Expressions}), while available | |
d4f3574e | 8745 | with any language, is not useful with Modula-2. Its |
c906108c | 8746 | intent is to aid the debugging of @dfn{dynamic arrays}, which cannot be |
b37052ae | 8747 | created in Modula-2 as they can in C or C@t{++}. However, because an |
c906108c | 8748 | address can be specified by an integral constant, the construct |
d4f3574e | 8749 | @samp{@{@var{type}@}@var{adrexp}} is still useful. |
c906108c SS |
8750 | |
8751 | @cindex @code{#} in Modula-2 | |
8752 | In @value{GDBN} scripts, the Modula-2 inequality operator @code{#} is | |
8753 | interpreted as the beginning of a comment. Use @code{<>} instead. | |
c906108c | 8754 | |
6d2ebf8b | 8755 | @node Symbols |
c906108c SS |
8756 | @chapter Examining the Symbol Table |
8757 | ||
d4f3574e | 8758 | The commands described in this chapter allow you to inquire about the |
c906108c SS |
8759 | symbols (names of variables, functions and types) defined in your |
8760 | program. This information is inherent in the text of your program and | |
8761 | does not change as your program executes. @value{GDBN} finds it in your | |
8762 | program's symbol table, in the file indicated when you started @value{GDBN} | |
8763 | (@pxref{File Options, ,Choosing files}), or by one of the | |
8764 | file-management commands (@pxref{Files, ,Commands to specify files}). | |
8765 | ||
8766 | @cindex symbol names | |
8767 | @cindex names of symbols | |
8768 | @cindex quoting names | |
8769 | Occasionally, you may need to refer to symbols that contain unusual | |
8770 | characters, which @value{GDBN} ordinarily treats as word delimiters. The | |
8771 | most frequent case is in referring to static variables in other | |
8772 | source files (@pxref{Variables,,Program variables}). File names | |
8773 | are recorded in object files as debugging symbols, but @value{GDBN} would | |
8774 | ordinarily parse a typical file name, like @file{foo.c}, as the three words | |
8775 | @samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize | |
8776 | @samp{foo.c} as a single symbol, enclose it in single quotes; for example, | |
8777 | ||
474c8240 | 8778 | @smallexample |
c906108c | 8779 | p 'foo.c'::x |
474c8240 | 8780 | @end smallexample |
c906108c SS |
8781 | |
8782 | @noindent | |
8783 | looks up the value of @code{x} in the scope of the file @file{foo.c}. | |
8784 | ||
8785 | @table @code | |
8786 | @kindex info address | |
b37052ae | 8787 | @cindex address of a symbol |
c906108c SS |
8788 | @item info address @var{symbol} |
8789 | Describe where the data for @var{symbol} is stored. For a register | |
8790 | variable, this says which register it is kept in. For a non-register | |
8791 | local variable, this prints the stack-frame offset at which the variable | |
8792 | is always stored. | |
8793 | ||
8794 | Note the contrast with @samp{print &@var{symbol}}, which does not work | |
8795 | at all for a register variable, and for a stack local variable prints | |
8796 | the exact address of the current instantiation of the variable. | |
8797 | ||
3d67e040 | 8798 | @kindex info symbol |
b37052ae | 8799 | @cindex symbol from address |
3d67e040 EZ |
8800 | @item info symbol @var{addr} |
8801 | Print the name of a symbol which is stored at the address @var{addr}. | |
8802 | If no symbol is stored exactly at @var{addr}, @value{GDBN} prints the | |
8803 | nearest symbol and an offset from it: | |
8804 | ||
474c8240 | 8805 | @smallexample |
3d67e040 EZ |
8806 | (@value{GDBP}) info symbol 0x54320 |
8807 | _initialize_vx + 396 in section .text | |
474c8240 | 8808 | @end smallexample |
3d67e040 EZ |
8809 | |
8810 | @noindent | |
8811 | This is the opposite of the @code{info address} command. You can use | |
8812 | it to find out the name of a variable or a function given its address. | |
8813 | ||
c906108c | 8814 | @kindex whatis |
d4f3574e SS |
8815 | @item whatis @var{expr} |
8816 | Print the data type of expression @var{expr}. @var{expr} is not | |
c906108c SS |
8817 | actually evaluated, and any side-effecting operations (such as |
8818 | assignments or function calls) inside it do not take place. | |
8819 | @xref{Expressions, ,Expressions}. | |
8820 | ||
8821 | @item whatis | |
8822 | Print the data type of @code{$}, the last value in the value history. | |
8823 | ||
8824 | @kindex ptype | |
8825 | @item ptype @var{typename} | |
8826 | Print a description of data type @var{typename}. @var{typename} may be | |
7a292a7a SS |
8827 | the name of a type, or for C code it may have the form @samp{class |
8828 | @var{class-name}}, @samp{struct @var{struct-tag}}, @samp{union | |
8829 | @var{union-tag}} or @samp{enum @var{enum-tag}}. | |
c906108c | 8830 | |
d4f3574e | 8831 | @item ptype @var{expr} |
c906108c | 8832 | @itemx ptype |
d4f3574e | 8833 | Print a description of the type of expression @var{expr}. @code{ptype} |
c906108c SS |
8834 | differs from @code{whatis} by printing a detailed description, instead |
8835 | of just the name of the type. | |
8836 | ||
8837 | For example, for this variable declaration: | |
8838 | ||
474c8240 | 8839 | @smallexample |
c906108c | 8840 | struct complex @{double real; double imag;@} v; |
474c8240 | 8841 | @end smallexample |
c906108c SS |
8842 | |
8843 | @noindent | |
8844 | the two commands give this output: | |
8845 | ||
474c8240 | 8846 | @smallexample |
c906108c SS |
8847 | @group |
8848 | (@value{GDBP}) whatis v | |
8849 | type = struct complex | |
8850 | (@value{GDBP}) ptype v | |
8851 | type = struct complex @{ | |
8852 | double real; | |
8853 | double imag; | |
8854 | @} | |
8855 | @end group | |
474c8240 | 8856 | @end smallexample |
c906108c SS |
8857 | |
8858 | @noindent | |
8859 | As with @code{whatis}, using @code{ptype} without an argument refers to | |
8860 | the type of @code{$}, the last value in the value history. | |
8861 | ||
8862 | @kindex info types | |
8863 | @item info types @var{regexp} | |
8864 | @itemx info types | |
d4f3574e | 8865 | Print a brief description of all types whose names match @var{regexp} |
c906108c SS |
8866 | (or all types in your program, if you supply no argument). Each |
8867 | complete typename is matched as though it were a complete line; thus, | |
8868 | @samp{i type value} gives information on all types in your program whose | |
d4f3574e | 8869 | names include the string @code{value}, but @samp{i type ^value$} gives |
c906108c SS |
8870 | information only on types whose complete name is @code{value}. |
8871 | ||
8872 | This command differs from @code{ptype} in two ways: first, like | |
8873 | @code{whatis}, it does not print a detailed description; second, it | |
8874 | lists all source files where a type is defined. | |
8875 | ||
b37052ae EZ |
8876 | @kindex info scope |
8877 | @cindex local variables | |
8878 | @item info scope @var{addr} | |
8879 | List all the variables local to a particular scope. This command | |
8880 | accepts a location---a function name, a source line, or an address | |
8881 | preceded by a @samp{*}, and prints all the variables local to the | |
8882 | scope defined by that location. For example: | |
8883 | ||
8884 | @smallexample | |
8885 | (@value{GDBP}) @b{info scope command_line_handler} | |
8886 | Scope for command_line_handler: | |
8887 | Symbol rl is an argument at stack/frame offset 8, length 4. | |
8888 | Symbol linebuffer is in static storage at address 0x150a18, length 4. | |
8889 | Symbol linelength is in static storage at address 0x150a1c, length 4. | |
8890 | Symbol p is a local variable in register $esi, length 4. | |
8891 | Symbol p1 is a local variable in register $ebx, length 4. | |
8892 | Symbol nline is a local variable in register $edx, length 4. | |
8893 | Symbol repeat is a local variable at frame offset -8, length 4. | |
8894 | @end smallexample | |
8895 | ||
f5c37c66 EZ |
8896 | @noindent |
8897 | This command is especially useful for determining what data to collect | |
8898 | during a @dfn{trace experiment}, see @ref{Tracepoint Actions, | |
8899 | collect}. | |
8900 | ||
c906108c SS |
8901 | @kindex info source |
8902 | @item info source | |
919d772c JB |
8903 | Show information about the current source file---that is, the source file for |
8904 | the function containing the current point of execution: | |
8905 | @itemize @bullet | |
8906 | @item | |
8907 | the name of the source file, and the directory containing it, | |
8908 | @item | |
8909 | the directory it was compiled in, | |
8910 | @item | |
8911 | its length, in lines, | |
8912 | @item | |
8913 | which programming language it is written in, | |
8914 | @item | |
8915 | whether the executable includes debugging information for that file, and | |
8916 | if so, what format the information is in (e.g., STABS, Dwarf 2, etc.), and | |
8917 | @item | |
8918 | whether the debugging information includes information about | |
8919 | preprocessor macros. | |
8920 | @end itemize | |
8921 | ||
c906108c SS |
8922 | |
8923 | @kindex info sources | |
8924 | @item info sources | |
8925 | Print the names of all source files in your program for which there is | |
8926 | debugging information, organized into two lists: files whose symbols | |
8927 | have already been read, and files whose symbols will be read when needed. | |
8928 | ||
8929 | @kindex info functions | |
8930 | @item info functions | |
8931 | Print the names and data types of all defined functions. | |
8932 | ||
8933 | @item info functions @var{regexp} | |
8934 | Print the names and data types of all defined functions | |
8935 | whose names contain a match for regular expression @var{regexp}. | |
8936 | Thus, @samp{info fun step} finds all functions whose names | |
8937 | include @code{step}; @samp{info fun ^step} finds those whose names | |
1c5dfdad MS |
8938 | start with @code{step}. If a function name contains characters |
8939 | that conflict with the regular expression language (eg. | |
8940 | @samp{operator*()}), they may be quoted with a backslash. | |
c906108c SS |
8941 | |
8942 | @kindex info variables | |
8943 | @item info variables | |
8944 | Print the names and data types of all variables that are declared | |
6ca652b0 | 8945 | outside of functions (i.e.@: excluding local variables). |
c906108c SS |
8946 | |
8947 | @item info variables @var{regexp} | |
8948 | Print the names and data types of all variables (except for local | |
8949 | variables) whose names contain a match for regular expression | |
8950 | @var{regexp}. | |
8951 | ||
8952 | @ignore | |
8953 | This was never implemented. | |
8954 | @kindex info methods | |
8955 | @item info methods | |
8956 | @itemx info methods @var{regexp} | |
8957 | The @code{info methods} command permits the user to examine all defined | |
b37052ae EZ |
8958 | methods within C@t{++} program, or (with the @var{regexp} argument) a |
8959 | specific set of methods found in the various C@t{++} classes. Many | |
8960 | C@t{++} classes provide a large number of methods. Thus, the output | |
c906108c SS |
8961 | from the @code{ptype} command can be overwhelming and hard to use. The |
8962 | @code{info-methods} command filters the methods, printing only those | |
8963 | which match the regular-expression @var{regexp}. | |
8964 | @end ignore | |
8965 | ||
c906108c SS |
8966 | @cindex reloading symbols |
8967 | Some systems allow individual object files that make up your program to | |
7a292a7a SS |
8968 | be replaced without stopping and restarting your program. For example, |
8969 | in VxWorks you can simply recompile a defective object file and keep on | |
8970 | running. If you are running on one of these systems, you can allow | |
8971 | @value{GDBN} to reload the symbols for automatically relinked modules: | |
c906108c SS |
8972 | |
8973 | @table @code | |
8974 | @kindex set symbol-reloading | |
8975 | @item set symbol-reloading on | |
8976 | Replace symbol definitions for the corresponding source file when an | |
8977 | object file with a particular name is seen again. | |
8978 | ||
8979 | @item set symbol-reloading off | |
6d2ebf8b SS |
8980 | Do not replace symbol definitions when encountering object files of the |
8981 | same name more than once. This is the default state; if you are not | |
8982 | running on a system that permits automatic relinking of modules, you | |
8983 | should leave @code{symbol-reloading} off, since otherwise @value{GDBN} | |
8984 | may discard symbols when linking large programs, that may contain | |
8985 | several modules (from different directories or libraries) with the same | |
8986 | name. | |
c906108c SS |
8987 | |
8988 | @kindex show symbol-reloading | |
8989 | @item show symbol-reloading | |
8990 | Show the current @code{on} or @code{off} setting. | |
8991 | @end table | |
c906108c | 8992 | |
c906108c SS |
8993 | @kindex set opaque-type-resolution |
8994 | @item set opaque-type-resolution on | |
8995 | Tell @value{GDBN} to resolve opaque types. An opaque type is a type | |
8996 | declared as a pointer to a @code{struct}, @code{class}, or | |
8997 | @code{union}---for example, @code{struct MyType *}---that is used in one | |
8998 | source file although the full declaration of @code{struct MyType} is in | |
8999 | another source file. The default is on. | |
9000 | ||
9001 | A change in the setting of this subcommand will not take effect until | |
9002 | the next time symbols for a file are loaded. | |
9003 | ||
9004 | @item set opaque-type-resolution off | |
9005 | Tell @value{GDBN} not to resolve opaque types. In this case, the type | |
9006 | is printed as follows: | |
9007 | @smallexample | |
9008 | @{<no data fields>@} | |
9009 | @end smallexample | |
9010 | ||
9011 | @kindex show opaque-type-resolution | |
9012 | @item show opaque-type-resolution | |
9013 | Show whether opaque types are resolved or not. | |
c906108c SS |
9014 | |
9015 | @kindex maint print symbols | |
9016 | @cindex symbol dump | |
9017 | @kindex maint print psymbols | |
9018 | @cindex partial symbol dump | |
9019 | @item maint print symbols @var{filename} | |
9020 | @itemx maint print psymbols @var{filename} | |
9021 | @itemx maint print msymbols @var{filename} | |
9022 | Write a dump of debugging symbol data into the file @var{filename}. | |
9023 | These commands are used to debug the @value{GDBN} symbol-reading code. Only | |
9024 | symbols with debugging data are included. If you use @samp{maint print | |
9025 | symbols}, @value{GDBN} includes all the symbols for which it has already | |
9026 | collected full details: that is, @var{filename} reflects symbols for | |
9027 | only those files whose symbols @value{GDBN} has read. You can use the | |
9028 | command @code{info sources} to find out which files these are. If you | |
9029 | use @samp{maint print psymbols} instead, the dump shows information about | |
9030 | symbols that @value{GDBN} only knows partially---that is, symbols defined in | |
9031 | files that @value{GDBN} has skimmed, but not yet read completely. Finally, | |
9032 | @samp{maint print msymbols} dumps just the minimal symbol information | |
9033 | required for each object file from which @value{GDBN} has read some symbols. | |
9034 | @xref{Files, ,Commands to specify files}, for a discussion of how | |
9035 | @value{GDBN} reads symbols (in the description of @code{symbol-file}). | |
9036 | @end table | |
9037 | ||
6d2ebf8b | 9038 | @node Altering |
c906108c SS |
9039 | @chapter Altering Execution |
9040 | ||
9041 | Once you think you have found an error in your program, you might want to | |
9042 | find out for certain whether correcting the apparent error would lead to | |
9043 | correct results in the rest of the run. You can find the answer by | |
9044 | experiment, using the @value{GDBN} features for altering execution of the | |
9045 | program. | |
9046 | ||
9047 | For example, you can store new values into variables or memory | |
7a292a7a SS |
9048 | locations, give your program a signal, restart it at a different |
9049 | address, or even return prematurely from a function. | |
c906108c SS |
9050 | |
9051 | @menu | |
9052 | * Assignment:: Assignment to variables | |
9053 | * Jumping:: Continuing at a different address | |
c906108c | 9054 | * Signaling:: Giving your program a signal |
c906108c SS |
9055 | * Returning:: Returning from a function |
9056 | * Calling:: Calling your program's functions | |
9057 | * Patching:: Patching your program | |
9058 | @end menu | |
9059 | ||
6d2ebf8b | 9060 | @node Assignment |
c906108c SS |
9061 | @section Assignment to variables |
9062 | ||
9063 | @cindex assignment | |
9064 | @cindex setting variables | |
9065 | To alter the value of a variable, evaluate an assignment expression. | |
9066 | @xref{Expressions, ,Expressions}. For example, | |
9067 | ||
474c8240 | 9068 | @smallexample |
c906108c | 9069 | print x=4 |
474c8240 | 9070 | @end smallexample |
c906108c SS |
9071 | |
9072 | @noindent | |
9073 | stores the value 4 into the variable @code{x}, and then prints the | |
5d161b24 | 9074 | value of the assignment expression (which is 4). |
c906108c SS |
9075 | @xref{Languages, ,Using @value{GDBN} with Different Languages}, for more |
9076 | information on operators in supported languages. | |
c906108c SS |
9077 | |
9078 | @kindex set variable | |
9079 | @cindex variables, setting | |
9080 | If you are not interested in seeing the value of the assignment, use the | |
9081 | @code{set} command instead of the @code{print} command. @code{set} is | |
9082 | really the same as @code{print} except that the expression's value is | |
9083 | not printed and is not put in the value history (@pxref{Value History, | |
9084 | ,Value history}). The expression is evaluated only for its effects. | |
9085 | ||
c906108c SS |
9086 | If the beginning of the argument string of the @code{set} command |
9087 | appears identical to a @code{set} subcommand, use the @code{set | |
9088 | variable} command instead of just @code{set}. This command is identical | |
9089 | to @code{set} except for its lack of subcommands. For example, if your | |
9090 | program has a variable @code{width}, you get an error if you try to set | |
9091 | a new value with just @samp{set width=13}, because @value{GDBN} has the | |
9092 | command @code{set width}: | |
9093 | ||
474c8240 | 9094 | @smallexample |
c906108c SS |
9095 | (@value{GDBP}) whatis width |
9096 | type = double | |
9097 | (@value{GDBP}) p width | |
9098 | $4 = 13 | |
9099 | (@value{GDBP}) set width=47 | |
9100 | Invalid syntax in expression. | |
474c8240 | 9101 | @end smallexample |
c906108c SS |
9102 | |
9103 | @noindent | |
9104 | The invalid expression, of course, is @samp{=47}. In | |
9105 | order to actually set the program's variable @code{width}, use | |
9106 | ||
474c8240 | 9107 | @smallexample |
c906108c | 9108 | (@value{GDBP}) set var width=47 |
474c8240 | 9109 | @end smallexample |
53a5351d | 9110 | |
c906108c SS |
9111 | Because the @code{set} command has many subcommands that can conflict |
9112 | with the names of program variables, it is a good idea to use the | |
9113 | @code{set variable} command instead of just @code{set}. For example, if | |
9114 | your program has a variable @code{g}, you run into problems if you try | |
9115 | to set a new value with just @samp{set g=4}, because @value{GDBN} has | |
9116 | the command @code{set gnutarget}, abbreviated @code{set g}: | |
9117 | ||
474c8240 | 9118 | @smallexample |
c906108c SS |
9119 | @group |
9120 | (@value{GDBP}) whatis g | |
9121 | type = double | |
9122 | (@value{GDBP}) p g | |
9123 | $1 = 1 | |
9124 | (@value{GDBP}) set g=4 | |
2df3850c | 9125 | (@value{GDBP}) p g |
c906108c SS |
9126 | $2 = 1 |
9127 | (@value{GDBP}) r | |
9128 | The program being debugged has been started already. | |
9129 | Start it from the beginning? (y or n) y | |
9130 | Starting program: /home/smith/cc_progs/a.out | |
6d2ebf8b SS |
9131 | "/home/smith/cc_progs/a.out": can't open to read symbols: |
9132 | Invalid bfd target. | |
c906108c SS |
9133 | (@value{GDBP}) show g |
9134 | The current BFD target is "=4". | |
9135 | @end group | |
474c8240 | 9136 | @end smallexample |
c906108c SS |
9137 | |
9138 | @noindent | |
9139 | The program variable @code{g} did not change, and you silently set the | |
9140 | @code{gnutarget} to an invalid value. In order to set the variable | |
9141 | @code{g}, use | |
9142 | ||
474c8240 | 9143 | @smallexample |
c906108c | 9144 | (@value{GDBP}) set var g=4 |
474c8240 | 9145 | @end smallexample |
c906108c SS |
9146 | |
9147 | @value{GDBN} allows more implicit conversions in assignments than C; you can | |
9148 | freely store an integer value into a pointer variable or vice versa, | |
9149 | and you can convert any structure to any other structure that is the | |
9150 | same length or shorter. | |
9151 | @comment FIXME: how do structs align/pad in these conversions? | |
9152 | @comment /doc@cygnus.com 18dec1990 | |
9153 | ||
9154 | To store values into arbitrary places in memory, use the @samp{@{@dots{}@}} | |
9155 | construct to generate a value of specified type at a specified address | |
9156 | (@pxref{Expressions, ,Expressions}). For example, @code{@{int@}0x83040} refers | |
9157 | to memory location @code{0x83040} as an integer (which implies a certain size | |
9158 | and representation in memory), and | |
9159 | ||
474c8240 | 9160 | @smallexample |
c906108c | 9161 | set @{int@}0x83040 = 4 |
474c8240 | 9162 | @end smallexample |
c906108c SS |
9163 | |
9164 | @noindent | |
9165 | stores the value 4 into that memory location. | |
9166 | ||
6d2ebf8b | 9167 | @node Jumping |
c906108c SS |
9168 | @section Continuing at a different address |
9169 | ||
9170 | Ordinarily, when you continue your program, you do so at the place where | |
9171 | it stopped, with the @code{continue} command. You can instead continue at | |
9172 | an address of your own choosing, with the following commands: | |
9173 | ||
9174 | @table @code | |
9175 | @kindex jump | |
9176 | @item jump @var{linespec} | |
9177 | Resume execution at line @var{linespec}. Execution stops again | |
9178 | immediately if there is a breakpoint there. @xref{List, ,Printing | |
9179 | source lines}, for a description of the different forms of | |
9180 | @var{linespec}. It is common practice to use the @code{tbreak} command | |
9181 | in conjunction with @code{jump}. @xref{Set Breaks, ,Setting | |
9182 | breakpoints}. | |
9183 | ||
9184 | The @code{jump} command does not change the current stack frame, or | |
9185 | the stack pointer, or the contents of any memory location or any | |
9186 | register other than the program counter. If line @var{linespec} is in | |
9187 | a different function from the one currently executing, the results may | |
9188 | be bizarre if the two functions expect different patterns of arguments or | |
9189 | of local variables. For this reason, the @code{jump} command requests | |
9190 | confirmation if the specified line is not in the function currently | |
9191 | executing. However, even bizarre results are predictable if you are | |
9192 | well acquainted with the machine-language code of your program. | |
9193 | ||
9194 | @item jump *@var{address} | |
9195 | Resume execution at the instruction at address @var{address}. | |
9196 | @end table | |
9197 | ||
c906108c | 9198 | @c Doesn't work on HP-UX; have to set $pcoqh and $pcoqt. |
53a5351d JM |
9199 | On many systems, you can get much the same effect as the @code{jump} |
9200 | command by storing a new value into the register @code{$pc}. The | |
9201 | difference is that this does not start your program running; it only | |
9202 | changes the address of where it @emph{will} run when you continue. For | |
9203 | example, | |
c906108c | 9204 | |
474c8240 | 9205 | @smallexample |
c906108c | 9206 | set $pc = 0x485 |
474c8240 | 9207 | @end smallexample |
c906108c SS |
9208 | |
9209 | @noindent | |
9210 | makes the next @code{continue} command or stepping command execute at | |
9211 | address @code{0x485}, rather than at the address where your program stopped. | |
9212 | @xref{Continuing and Stepping, ,Continuing and stepping}. | |
c906108c SS |
9213 | |
9214 | The most common occasion to use the @code{jump} command is to back | |
9215 | up---perhaps with more breakpoints set---over a portion of a program | |
9216 | that has already executed, in order to examine its execution in more | |
9217 | detail. | |
9218 | ||
c906108c | 9219 | @c @group |
6d2ebf8b | 9220 | @node Signaling |
c906108c SS |
9221 | @section Giving your program a signal |
9222 | ||
9223 | @table @code | |
9224 | @kindex signal | |
9225 | @item signal @var{signal} | |
9226 | Resume execution where your program stopped, but immediately give it the | |
9227 | signal @var{signal}. @var{signal} can be the name or the number of a | |
9228 | signal. For example, on many systems @code{signal 2} and @code{signal | |
9229 | SIGINT} are both ways of sending an interrupt signal. | |
9230 | ||
9231 | Alternatively, if @var{signal} is zero, continue execution without | |
9232 | giving a signal. This is useful when your program stopped on account of | |
9233 | a signal and would ordinary see the signal when resumed with the | |
9234 | @code{continue} command; @samp{signal 0} causes it to resume without a | |
9235 | signal. | |
9236 | ||
9237 | @code{signal} does not repeat when you press @key{RET} a second time | |
9238 | after executing the command. | |
9239 | @end table | |
9240 | @c @end group | |
9241 | ||
9242 | Invoking the @code{signal} command is not the same as invoking the | |
9243 | @code{kill} utility from the shell. Sending a signal with @code{kill} | |
9244 | causes @value{GDBN} to decide what to do with the signal depending on | |
9245 | the signal handling tables (@pxref{Signals}). The @code{signal} command | |
9246 | passes the signal directly to your program. | |
9247 | ||
c906108c | 9248 | |
6d2ebf8b | 9249 | @node Returning |
c906108c SS |
9250 | @section Returning from a function |
9251 | ||
9252 | @table @code | |
9253 | @cindex returning from a function | |
9254 | @kindex return | |
9255 | @item return | |
9256 | @itemx return @var{expression} | |
9257 | You can cancel execution of a function call with the @code{return} | |
9258 | command. If you give an | |
9259 | @var{expression} argument, its value is used as the function's return | |
9260 | value. | |
9261 | @end table | |
9262 | ||
9263 | When you use @code{return}, @value{GDBN} discards the selected stack frame | |
9264 | (and all frames within it). You can think of this as making the | |
9265 | discarded frame return prematurely. If you wish to specify a value to | |
9266 | be returned, give that value as the argument to @code{return}. | |
9267 | ||
9268 | This pops the selected stack frame (@pxref{Selection, ,Selecting a | |
9269 | frame}), and any other frames inside of it, leaving its caller as the | |
9270 | innermost remaining frame. That frame becomes selected. The | |
9271 | specified value is stored in the registers used for returning values | |
9272 | of functions. | |
9273 | ||
9274 | The @code{return} command does not resume execution; it leaves the | |
9275 | program stopped in the state that would exist if the function had just | |
9276 | returned. In contrast, the @code{finish} command (@pxref{Continuing | |
9277 | and Stepping, ,Continuing and stepping}) resumes execution until the | |
9278 | selected stack frame returns naturally. | |
9279 | ||
6d2ebf8b | 9280 | @node Calling |
c906108c SS |
9281 | @section Calling program functions |
9282 | ||
9283 | @cindex calling functions | |
9284 | @kindex call | |
9285 | @table @code | |
9286 | @item call @var{expr} | |
9287 | Evaluate the expression @var{expr} without displaying @code{void} | |
9288 | returned values. | |
9289 | @end table | |
9290 | ||
9291 | You can use this variant of the @code{print} command if you want to | |
9292 | execute a function from your program, but without cluttering the output | |
5d161b24 DB |
9293 | with @code{void} returned values. If the result is not void, it |
9294 | is printed and saved in the value history. | |
c906108c | 9295 | |
6d2ebf8b | 9296 | @node Patching |
c906108c | 9297 | @section Patching programs |
7a292a7a | 9298 | |
c906108c SS |
9299 | @cindex patching binaries |
9300 | @cindex writing into executables | |
c906108c | 9301 | @cindex writing into corefiles |
c906108c | 9302 | |
7a292a7a SS |
9303 | By default, @value{GDBN} opens the file containing your program's |
9304 | executable code (or the corefile) read-only. This prevents accidental | |
9305 | alterations to machine code; but it also prevents you from intentionally | |
9306 | patching your program's binary. | |
c906108c SS |
9307 | |
9308 | If you'd like to be able to patch the binary, you can specify that | |
9309 | explicitly with the @code{set write} command. For example, you might | |
9310 | want to turn on internal debugging flags, or even to make emergency | |
9311 | repairs. | |
9312 | ||
9313 | @table @code | |
9314 | @kindex set write | |
9315 | @item set write on | |
9316 | @itemx set write off | |
7a292a7a SS |
9317 | If you specify @samp{set write on}, @value{GDBN} opens executable and |
9318 | core files for both reading and writing; if you specify @samp{set write | |
c906108c SS |
9319 | off} (the default), @value{GDBN} opens them read-only. |
9320 | ||
9321 | If you have already loaded a file, you must load it again (using the | |
7a292a7a SS |
9322 | @code{exec-file} or @code{core-file} command) after changing @code{set |
9323 | write}, for your new setting to take effect. | |
c906108c SS |
9324 | |
9325 | @item show write | |
9326 | @kindex show write | |
7a292a7a SS |
9327 | Display whether executable files and core files are opened for writing |
9328 | as well as reading. | |
c906108c SS |
9329 | @end table |
9330 | ||
6d2ebf8b | 9331 | @node GDB Files |
c906108c SS |
9332 | @chapter @value{GDBN} Files |
9333 | ||
7a292a7a SS |
9334 | @value{GDBN} needs to know the file name of the program to be debugged, |
9335 | both in order to read its symbol table and in order to start your | |
9336 | program. To debug a core dump of a previous run, you must also tell | |
9337 | @value{GDBN} the name of the core dump file. | |
c906108c SS |
9338 | |
9339 | @menu | |
9340 | * Files:: Commands to specify files | |
5b5d99cf | 9341 | * Separate Debug Files:: Debugging information in separate files |
c906108c SS |
9342 | * Symbol Errors:: Errors reading symbol files |
9343 | @end menu | |
9344 | ||
6d2ebf8b | 9345 | @node Files |
c906108c | 9346 | @section Commands to specify files |
c906108c | 9347 | |
7a292a7a | 9348 | @cindex symbol table |
c906108c | 9349 | @cindex core dump file |
7a292a7a SS |
9350 | |
9351 | You may want to specify executable and core dump file names. The usual | |
9352 | way to do this is at start-up time, using the arguments to | |
9353 | @value{GDBN}'s start-up commands (@pxref{Invocation, , Getting In and | |
9354 | Out of @value{GDBN}}). | |
c906108c SS |
9355 | |
9356 | Occasionally it is necessary to change to a different file during a | |
9357 | @value{GDBN} session. Or you may run @value{GDBN} and forget to specify | |
9358 | a file you want to use. In these situations the @value{GDBN} commands | |
9359 | to specify new files are useful. | |
9360 | ||
9361 | @table @code | |
9362 | @cindex executable file | |
9363 | @kindex file | |
9364 | @item file @var{filename} | |
9365 | Use @var{filename} as the program to be debugged. It is read for its | |
9366 | symbols and for the contents of pure memory. It is also the program | |
9367 | executed when you use the @code{run} command. If you do not specify a | |
5d161b24 DB |
9368 | directory and the file is not found in the @value{GDBN} working directory, |
9369 | @value{GDBN} uses the environment variable @code{PATH} as a list of | |
9370 | directories to search, just as the shell does when looking for a program | |
9371 | to run. You can change the value of this variable, for both @value{GDBN} | |
c906108c SS |
9372 | and your program, using the @code{path} command. |
9373 | ||
6d2ebf8b | 9374 | On systems with memory-mapped files, an auxiliary file named |
c906108c SS |
9375 | @file{@var{filename}.syms} may hold symbol table information for |
9376 | @var{filename}. If so, @value{GDBN} maps in the symbol table from | |
9377 | @file{@var{filename}.syms}, starting up more quickly. See the | |
9378 | descriptions of the file options @samp{-mapped} and @samp{-readnow} | |
9379 | (available on the command line, and with the commands @code{file}, | |
5d161b24 | 9380 | @code{symbol-file}, or @code{add-symbol-file}, described below), |
c906108c | 9381 | for more information. |
c906108c SS |
9382 | |
9383 | @item file | |
9384 | @code{file} with no argument makes @value{GDBN} discard any information it | |
9385 | has on both executable file and the symbol table. | |
9386 | ||
9387 | @kindex exec-file | |
9388 | @item exec-file @r{[} @var{filename} @r{]} | |
9389 | Specify that the program to be run (but not the symbol table) is found | |
9390 | in @var{filename}. @value{GDBN} searches the environment variable @code{PATH} | |
9391 | if necessary to locate your program. Omitting @var{filename} means to | |
9392 | discard information on the executable file. | |
9393 | ||
9394 | @kindex symbol-file | |
9395 | @item symbol-file @r{[} @var{filename} @r{]} | |
9396 | Read symbol table information from file @var{filename}. @code{PATH} is | |
9397 | searched when necessary. Use the @code{file} command to get both symbol | |
9398 | table and program to run from the same file. | |
9399 | ||
9400 | @code{symbol-file} with no argument clears out @value{GDBN} information on your | |
9401 | program's symbol table. | |
9402 | ||
5d161b24 | 9403 | The @code{symbol-file} command causes @value{GDBN} to forget the contents |
c906108c SS |
9404 | of its convenience variables, the value history, and all breakpoints and |
9405 | auto-display expressions. This is because they may contain pointers to | |
9406 | the internal data recording symbols and data types, which are part of | |
9407 | the old symbol table data being discarded inside @value{GDBN}. | |
9408 | ||
9409 | @code{symbol-file} does not repeat if you press @key{RET} again after | |
9410 | executing it once. | |
9411 | ||
9412 | When @value{GDBN} is configured for a particular environment, it | |
9413 | understands debugging information in whatever format is the standard | |
9414 | generated for that environment; you may use either a @sc{gnu} compiler, or | |
9415 | other compilers that adhere to the local conventions. | |
c906108c SS |
9416 | Best results are usually obtained from @sc{gnu} compilers; for example, |
9417 | using @code{@value{GCC}} you can generate debugging information for | |
9418 | optimized code. | |
c906108c SS |
9419 | |
9420 | For most kinds of object files, with the exception of old SVR3 systems | |
9421 | using COFF, the @code{symbol-file} command does not normally read the | |
9422 | symbol table in full right away. Instead, it scans the symbol table | |
9423 | quickly to find which source files and which symbols are present. The | |
9424 | details are read later, one source file at a time, as they are needed. | |
9425 | ||
9426 | The purpose of this two-stage reading strategy is to make @value{GDBN} | |
9427 | start up faster. For the most part, it is invisible except for | |
9428 | occasional pauses while the symbol table details for a particular source | |
9429 | file are being read. (The @code{set verbose} command can turn these | |
9430 | pauses into messages if desired. @xref{Messages/Warnings, ,Optional | |
9431 | warnings and messages}.) | |
9432 | ||
c906108c SS |
9433 | We have not implemented the two-stage strategy for COFF yet. When the |
9434 | symbol table is stored in COFF format, @code{symbol-file} reads the | |
9435 | symbol table data in full right away. Note that ``stabs-in-COFF'' | |
9436 | still does the two-stage strategy, since the debug info is actually | |
9437 | in stabs format. | |
9438 | ||
9439 | @kindex readnow | |
9440 | @cindex reading symbols immediately | |
9441 | @cindex symbols, reading immediately | |
9442 | @kindex mapped | |
9443 | @cindex memory-mapped symbol file | |
9444 | @cindex saving symbol table | |
9445 | @item symbol-file @var{filename} @r{[} -readnow @r{]} @r{[} -mapped @r{]} | |
9446 | @itemx file @var{filename} @r{[} -readnow @r{]} @r{[} -mapped @r{]} | |
9447 | You can override the @value{GDBN} two-stage strategy for reading symbol | |
9448 | tables by using the @samp{-readnow} option with any of the commands that | |
9449 | load symbol table information, if you want to be sure @value{GDBN} has the | |
5d161b24 | 9450 | entire symbol table available. |
c906108c | 9451 | |
c906108c SS |
9452 | If memory-mapped files are available on your system through the |
9453 | @code{mmap} system call, you can use another option, @samp{-mapped}, to | |
9454 | cause @value{GDBN} to write the symbols for your program into a reusable | |
9455 | file. Future @value{GDBN} debugging sessions map in symbol information | |
9456 | from this auxiliary symbol file (if the program has not changed), rather | |
9457 | than spending time reading the symbol table from the executable | |
9458 | program. Using the @samp{-mapped} option has the same effect as | |
9459 | starting @value{GDBN} with the @samp{-mapped} command-line option. | |
9460 | ||
9461 | You can use both options together, to make sure the auxiliary symbol | |
9462 | file has all the symbol information for your program. | |
9463 | ||
9464 | The auxiliary symbol file for a program called @var{myprog} is called | |
9465 | @samp{@var{myprog}.syms}. Once this file exists (so long as it is newer | |
9466 | than the corresponding executable), @value{GDBN} always attempts to use | |
9467 | it when you debug @var{myprog}; no special options or commands are | |
9468 | needed. | |
9469 | ||
9470 | The @file{.syms} file is specific to the host machine where you run | |
9471 | @value{GDBN}. It holds an exact image of the internal @value{GDBN} | |
9472 | symbol table. It cannot be shared across multiple host platforms. | |
c906108c SS |
9473 | |
9474 | @c FIXME: for now no mention of directories, since this seems to be in | |
9475 | @c flux. 13mar1992 status is that in theory GDB would look either in | |
9476 | @c current dir or in same dir as myprog; but issues like competing | |
9477 | @c GDB's, or clutter in system dirs, mean that in practice right now | |
9478 | @c only current dir is used. FFish says maybe a special GDB hierarchy | |
9479 | @c (eg rooted in val of env var GDBSYMS) could exist for mappable symbol | |
9480 | @c files. | |
9481 | ||
9482 | @kindex core | |
9483 | @kindex core-file | |
9484 | @item core-file @r{[} @var{filename} @r{]} | |
9485 | Specify the whereabouts of a core dump file to be used as the ``contents | |
9486 | of memory''. Traditionally, core files contain only some parts of the | |
9487 | address space of the process that generated them; @value{GDBN} can access the | |
9488 | executable file itself for other parts. | |
9489 | ||
9490 | @code{core-file} with no argument specifies that no core file is | |
9491 | to be used. | |
9492 | ||
9493 | Note that the core file is ignored when your program is actually running | |
7a292a7a SS |
9494 | under @value{GDBN}. So, if you have been running your program and you |
9495 | wish to debug a core file instead, you must kill the subprocess in which | |
9496 | the program is running. To do this, use the @code{kill} command | |
c906108c | 9497 | (@pxref{Kill Process, ,Killing the child process}). |
c906108c | 9498 | |
c906108c SS |
9499 | @kindex add-symbol-file |
9500 | @cindex dynamic linking | |
9501 | @item add-symbol-file @var{filename} @var{address} | |
9502 | @itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]} @r{[} -mapped @r{]} | |
17d9d558 | 9503 | @itemx add-symbol-file @var{filename} @r{-s}@var{section} @var{address} @dots{} |
96a2c332 SS |
9504 | The @code{add-symbol-file} command reads additional symbol table |
9505 | information from the file @var{filename}. You would use this command | |
9506 | when @var{filename} has been dynamically loaded (by some other means) | |
9507 | into the program that is running. @var{address} should be the memory | |
9508 | address at which the file has been loaded; @value{GDBN} cannot figure | |
d167840f EZ |
9509 | this out for itself. You can additionally specify an arbitrary number |
9510 | of @samp{@r{-s}@var{section} @var{address}} pairs, to give an explicit | |
9511 | section name and base address for that section. You can specify any | |
9512 | @var{address} as an expression. | |
c906108c SS |
9513 | |
9514 | The symbol table of the file @var{filename} is added to the symbol table | |
9515 | originally read with the @code{symbol-file} command. You can use the | |
96a2c332 SS |
9516 | @code{add-symbol-file} command any number of times; the new symbol data |
9517 | thus read keeps adding to the old. To discard all old symbol data | |
9518 | instead, use the @code{symbol-file} command without any arguments. | |
c906108c | 9519 | |
17d9d558 JB |
9520 | @cindex relocatable object files, reading symbols from |
9521 | @cindex object files, relocatable, reading symbols from | |
9522 | @cindex reading symbols from relocatable object files | |
9523 | @cindex symbols, reading from relocatable object files | |
9524 | @cindex @file{.o} files, reading symbols from | |
9525 | Although @var{filename} is typically a shared library file, an | |
9526 | executable file, or some other object file which has been fully | |
9527 | relocated for loading into a process, you can also load symbolic | |
9528 | information from relocatable @file{.o} files, as long as: | |
9529 | ||
9530 | @itemize @bullet | |
9531 | @item | |
9532 | the file's symbolic information refers only to linker symbols defined in | |
9533 | that file, not to symbols defined by other object files, | |
9534 | @item | |
9535 | every section the file's symbolic information refers to has actually | |
9536 | been loaded into the inferior, as it appears in the file, and | |
9537 | @item | |
9538 | you can determine the address at which every section was loaded, and | |
9539 | provide these to the @code{add-symbol-file} command. | |
9540 | @end itemize | |
9541 | ||
9542 | @noindent | |
9543 | Some embedded operating systems, like Sun Chorus and VxWorks, can load | |
9544 | relocatable files into an already running program; such systems | |
9545 | typically make the requirements above easy to meet. However, it's | |
9546 | important to recognize that many native systems use complex link | |
9547 | procedures (@code{.linkonce} section factoring and C++ constructor table | |
9548 | assembly, for example) that make the requirements difficult to meet. In | |
9549 | general, one cannot assume that using @code{add-symbol-file} to read a | |
9550 | relocatable object file's symbolic information will have the same effect | |
9551 | as linking the relocatable object file into the program in the normal | |
9552 | way. | |
9553 | ||
c906108c SS |
9554 | @code{add-symbol-file} does not repeat if you press @key{RET} after using it. |
9555 | ||
9556 | You can use the @samp{-mapped} and @samp{-readnow} options just as with | |
9557 | the @code{symbol-file} command, to change how @value{GDBN} manages the symbol | |
9558 | table information for @var{filename}. | |
9559 | ||
9560 | @kindex add-shared-symbol-file | |
9561 | @item add-shared-symbol-file | |
9562 | The @code{add-shared-symbol-file} command can be used only under Harris' CXUX | |
5d161b24 DB |
9563 | operating system for the Motorola 88k. @value{GDBN} automatically looks for |
9564 | shared libraries, however if @value{GDBN} does not find yours, you can run | |
c906108c | 9565 | @code{add-shared-symbol-file}. It takes no arguments. |
c906108c | 9566 | |
c906108c SS |
9567 | @kindex section |
9568 | @item section | |
5d161b24 DB |
9569 | The @code{section} command changes the base address of section SECTION of |
9570 | the exec file to ADDR. This can be used if the exec file does not contain | |
9571 | section addresses, (such as in the a.out format), or when the addresses | |
9572 | specified in the file itself are wrong. Each section must be changed | |
d4f3574e SS |
9573 | separately. The @code{info files} command, described below, lists all |
9574 | the sections and their addresses. | |
c906108c SS |
9575 | |
9576 | @kindex info files | |
9577 | @kindex info target | |
9578 | @item info files | |
9579 | @itemx info target | |
7a292a7a SS |
9580 | @code{info files} and @code{info target} are synonymous; both print the |
9581 | current target (@pxref{Targets, ,Specifying a Debugging Target}), | |
9582 | including the names of the executable and core dump files currently in | |
9583 | use by @value{GDBN}, and the files from which symbols were loaded. The | |
9584 | command @code{help target} lists all possible targets rather than | |
9585 | current ones. | |
9586 | ||
fe95c787 MS |
9587 | @kindex maint info sections |
9588 | @item maint info sections | |
9589 | Another command that can give you extra information about program sections | |
9590 | is @code{maint info sections}. In addition to the section information | |
9591 | displayed by @code{info files}, this command displays the flags and file | |
9592 | offset of each section in the executable and core dump files. In addition, | |
9593 | @code{maint info sections} provides the following command options (which | |
9594 | may be arbitrarily combined): | |
9595 | ||
9596 | @table @code | |
9597 | @item ALLOBJ | |
9598 | Display sections for all loaded object files, including shared libraries. | |
9599 | @item @var{sections} | |
6600abed | 9600 | Display info only for named @var{sections}. |
fe95c787 MS |
9601 | @item @var{section-flags} |
9602 | Display info only for sections for which @var{section-flags} are true. | |
9603 | The section flags that @value{GDBN} currently knows about are: | |
9604 | @table @code | |
9605 | @item ALLOC | |
9606 | Section will have space allocated in the process when loaded. | |
9607 | Set for all sections except those containing debug information. | |
9608 | @item LOAD | |
9609 | Section will be loaded from the file into the child process memory. | |
9610 | Set for pre-initialized code and data, clear for @code{.bss} sections. | |
9611 | @item RELOC | |
9612 | Section needs to be relocated before loading. | |
9613 | @item READONLY | |
9614 | Section cannot be modified by the child process. | |
9615 | @item CODE | |
9616 | Section contains executable code only. | |
6600abed | 9617 | @item DATA |
fe95c787 MS |
9618 | Section contains data only (no executable code). |
9619 | @item ROM | |
9620 | Section will reside in ROM. | |
9621 | @item CONSTRUCTOR | |
9622 | Section contains data for constructor/destructor lists. | |
9623 | @item HAS_CONTENTS | |
9624 | Section is not empty. | |
9625 | @item NEVER_LOAD | |
9626 | An instruction to the linker to not output the section. | |
9627 | @item COFF_SHARED_LIBRARY | |
9628 | A notification to the linker that the section contains | |
9629 | COFF shared library information. | |
9630 | @item IS_COMMON | |
9631 | Section contains common symbols. | |
9632 | @end table | |
9633 | @end table | |
6763aef9 MS |
9634 | @kindex set trust-readonly-sections |
9635 | @item set trust-readonly-sections on | |
9636 | Tell @value{GDBN} that readonly sections in your object file | |
6ca652b0 | 9637 | really are read-only (i.e.@: that their contents will not change). |
6763aef9 MS |
9638 | In that case, @value{GDBN} can fetch values from these sections |
9639 | out of the object file, rather than from the target program. | |
9640 | For some targets (notably embedded ones), this can be a significant | |
9641 | enhancement to debugging performance. | |
9642 | ||
9643 | The default is off. | |
9644 | ||
9645 | @item set trust-readonly-sections off | |
15110bc3 | 9646 | Tell @value{GDBN} not to trust readonly sections. This means that |
6763aef9 MS |
9647 | the contents of the section might change while the program is running, |
9648 | and must therefore be fetched from the target when needed. | |
c906108c SS |
9649 | @end table |
9650 | ||
9651 | All file-specifying commands allow both absolute and relative file names | |
9652 | as arguments. @value{GDBN} always converts the file name to an absolute file | |
9653 | name and remembers it that way. | |
9654 | ||
c906108c | 9655 | @cindex shared libraries |
c906108c SS |
9656 | @value{GDBN} supports HP-UX, SunOS, SVr4, Irix 5, and IBM RS/6000 shared |
9657 | libraries. | |
53a5351d | 9658 | |
c906108c SS |
9659 | @value{GDBN} automatically loads symbol definitions from shared libraries |
9660 | when you use the @code{run} command, or when you examine a core file. | |
9661 | (Before you issue the @code{run} command, @value{GDBN} does not understand | |
9662 | references to a function in a shared library, however---unless you are | |
9663 | debugging a core file). | |
53a5351d JM |
9664 | |
9665 | On HP-UX, if the program loads a library explicitly, @value{GDBN} | |
9666 | automatically loads the symbols at the time of the @code{shl_load} call. | |
9667 | ||
c906108c SS |
9668 | @c FIXME: some @value{GDBN} release may permit some refs to undef |
9669 | @c FIXME...symbols---eg in a break cmd---assuming they are from a shared | |
9670 | @c FIXME...lib; check this from time to time when updating manual | |
9671 | ||
b7209cb4 FF |
9672 | There are times, however, when you may wish to not automatically load |
9673 | symbol definitions from shared libraries, such as when they are | |
9674 | particularly large or there are many of them. | |
9675 | ||
9676 | To control the automatic loading of shared library symbols, use the | |
9677 | commands: | |
9678 | ||
9679 | @table @code | |
9680 | @kindex set auto-solib-add | |
9681 | @item set auto-solib-add @var{mode} | |
9682 | If @var{mode} is @code{on}, symbols from all shared object libraries | |
9683 | will be loaded automatically when the inferior begins execution, you | |
9684 | attach to an independently started inferior, or when the dynamic linker | |
9685 | informs @value{GDBN} that a new library has been loaded. If @var{mode} | |
9686 | is @code{off}, symbols must be loaded manually, using the | |
9687 | @code{sharedlibrary} command. The default value is @code{on}. | |
9688 | ||
9689 | @kindex show auto-solib-add | |
9690 | @item show auto-solib-add | |
9691 | Display the current autoloading mode. | |
9692 | @end table | |
9693 | ||
9694 | To explicitly load shared library symbols, use the @code{sharedlibrary} | |
9695 | command: | |
9696 | ||
c906108c SS |
9697 | @table @code |
9698 | @kindex info sharedlibrary | |
9699 | @kindex info share | |
9700 | @item info share | |
9701 | @itemx info sharedlibrary | |
9702 | Print the names of the shared libraries which are currently loaded. | |
9703 | ||
9704 | @kindex sharedlibrary | |
9705 | @kindex share | |
9706 | @item sharedlibrary @var{regex} | |
9707 | @itemx share @var{regex} | |
c906108c SS |
9708 | Load shared object library symbols for files matching a |
9709 | Unix regular expression. | |
9710 | As with files loaded automatically, it only loads shared libraries | |
9711 | required by your program for a core file or after typing @code{run}. If | |
9712 | @var{regex} is omitted all shared libraries required by your program are | |
9713 | loaded. | |
9714 | @end table | |
9715 | ||
b7209cb4 FF |
9716 | On some systems, such as HP-UX systems, @value{GDBN} supports |
9717 | autoloading shared library symbols until a limiting threshold size is | |
9718 | reached. This provides the benefit of allowing autoloading to remain on | |
9719 | by default, but avoids autoloading excessively large shared libraries, | |
9720 | up to a threshold that is initially set, but which you can modify if you | |
9721 | wish. | |
c906108c SS |
9722 | |
9723 | Beyond that threshold, symbols from shared libraries must be explicitly | |
d4f3574e SS |
9724 | loaded. To load these symbols, use the command @code{sharedlibrary |
9725 | @var{filename}}. The base address of the shared library is determined | |
c906108c SS |
9726 | automatically by @value{GDBN} and need not be specified. |
9727 | ||
9728 | To display or set the threshold, use the commands: | |
9729 | ||
9730 | @table @code | |
b7209cb4 FF |
9731 | @kindex set auto-solib-limit |
9732 | @item set auto-solib-limit @var{threshold} | |
9733 | Set the autoloading size threshold, in an integral number of megabytes. | |
9734 | If @var{threshold} is nonzero and shared library autoloading is enabled, | |
9735 | symbols from all shared object libraries will be loaded until the total | |
9736 | size of the loaded shared library symbols exceeds this threshold. | |
c906108c | 9737 | Otherwise, symbols must be loaded manually, using the |
6ca652b0 | 9738 | @code{sharedlibrary} command. The default threshold is 100 (i.e.@: 100 |
b7209cb4 | 9739 | Mb). |
c906108c | 9740 | |
b7209cb4 FF |
9741 | @kindex show auto-solib-limit |
9742 | @item show auto-solib-limit | |
c906108c SS |
9743 | Display the current autoloading size threshold, in megabytes. |
9744 | @end table | |
c906108c | 9745 | |
f5ebfba0 DJ |
9746 | Shared libraries are also supported in many cross or remote debugging |
9747 | configurations. A copy of the target's libraries need to be present on the | |
9748 | host system; they need to be the same as the target libraries, although the | |
9749 | copies on the target can be stripped as long as the copies on the host are | |
9750 | not. | |
9751 | ||
9752 | You need to tell @value{GDBN} where the target libraries are, so that it can | |
9753 | load the correct copies---otherwise, it may try to load the host's libraries. | |
9754 | @value{GDBN} has two variables to specify the search directories for target | |
9755 | libraries. | |
9756 | ||
9757 | @table @code | |
9758 | @kindex set solib-absolute-prefix | |
9759 | @item set solib-absolute-prefix @var{path} | |
9760 | If this variable is set, @var{path} will be used as a prefix for any | |
9761 | absolute shared library paths; many runtime loaders store the absolute | |
9762 | paths to the shared library in the target program's memory. If you use | |
9763 | @samp{solib-absolute-prefix} to find shared libraries, they need to be laid | |
9764 | out in the same way that they are on the target, with e.g.@: a | |
9765 | @file{/usr/lib} hierarchy under @var{path}. | |
9766 | ||
9767 | You can set the default value of @samp{solib-absolute-prefix} by using the | |
9768 | configure-time @samp{--with-sysroot} option. | |
9769 | ||
9770 | @kindex show solib-absolute-prefix | |
9771 | @item show solib-absolute-prefix | |
9772 | Display the current shared library prefix. | |
9773 | ||
9774 | @kindex set solib-search-path | |
9775 | @item set solib-search-path @var{path} | |
9776 | If this variable is set, @var{path} is a colon-separated list of directories | |
9777 | to search for shared libraries. @samp{solib-search-path} is used after | |
9778 | @samp{solib-absolute-prefix} fails to locate the library, or if the path to | |
9779 | the library is relative instead of absolute. If you want to use | |
9780 | @samp{solib-search-path} instead of @samp{solib-absolute-prefix}, be sure to | |
9781 | set @samp{solib-absolute-prefix} to a nonexistant directory to prevent | |
9782 | @value{GDBN} from finding your host's libraries. | |
9783 | ||
9784 | @kindex show solib-search-path | |
9785 | @item show solib-search-path | |
9786 | Display the current shared library search path. | |
9787 | @end table | |
9788 | ||
5b5d99cf JB |
9789 | |
9790 | @node Separate Debug Files | |
9791 | @section Debugging Information in Separate Files | |
9792 | @cindex separate debugging information files | |
9793 | @cindex debugging information in separate files | |
9794 | @cindex @file{.debug} subdirectories | |
9795 | @cindex debugging information directory, global | |
9796 | @cindex global debugging information directory | |
9797 | ||
9798 | @value{GDBN} allows you to put a program's debugging information in a | |
9799 | file separate from the executable itself, in a way that allows | |
9800 | @value{GDBN} to find and load the debugging information automatically. | |
9801 | Since debugging information can be very large --- sometimes larger | |
9802 | than the executable code itself --- some systems distribute debugging | |
9803 | information for their executables in separate files, which users can | |
9804 | install only when they need to debug a problem. | |
9805 | ||
9806 | If an executable's debugging information has been extracted to a | |
9807 | separate file, the executable should contain a @dfn{debug link} giving | |
9808 | the name of the debugging information file (with no directory | |
9809 | components), and a checksum of its contents. (The exact form of a | |
9810 | debug link is described below.) If the full name of the directory | |
9811 | containing the executable is @var{execdir}, and the executable has a | |
9812 | debug link that specifies the name @var{debugfile}, then @value{GDBN} | |
9813 | will automatically search for the debugging information file in three | |
9814 | places: | |
9815 | ||
9816 | @itemize @bullet | |
9817 | @item | |
9818 | the directory containing the executable file (that is, it will look | |
9819 | for a file named @file{@var{execdir}/@var{debugfile}}, | |
9820 | @item | |
9821 | a subdirectory of that directory named @file{.debug} (that is, the | |
9822 | file @file{@var{execdir}/.debug/@var{debugfile}}, and | |
9823 | @item | |
9824 | a subdirectory of the global debug file directory that includes the | |
9825 | executable's full path, and the name from the link (that is, the file | |
9826 | @file{@var{globaldebugdir}/@var{execdir}/@var{debugfile}}, where | |
9827 | @var{globaldebugdir} is the global debug file directory, and | |
9828 | @var{execdir} has been turned into a relative path). | |
9829 | @end itemize | |
9830 | @noindent | |
9831 | @value{GDBN} checks under each of these names for a debugging | |
9832 | information file whose checksum matches that given in the link, and | |
9833 | reads the debugging information from the first one it finds. | |
9834 | ||
9835 | So, for example, if you ask @value{GDBN} to debug @file{/usr/bin/ls}, | |
9836 | which has a link containing the name @file{ls.debug}, and the global | |
9837 | debug directory is @file{/usr/lib/debug}, then @value{GDBN} will look | |
9838 | for debug information in @file{/usr/bin/ls.debug}, | |
9839 | @file{/usr/bin/.debug/ls.debug}, and | |
9840 | @file{/usr/lib/debug/usr/bin/ls.debug}. | |
9841 | ||
9842 | You can set the global debugging info directory's name, and view the | |
9843 | name @value{GDBN} is currently using. | |
9844 | ||
9845 | @table @code | |
9846 | ||
9847 | @kindex set debug-file-directory | |
9848 | @item set debug-file-directory @var{directory} | |
9849 | Set the directory which @value{GDBN} searches for separate debugging | |
9850 | information files to @var{directory}. | |
9851 | ||
9852 | @kindex show debug-file-directory | |
9853 | @item show debug-file-directory | |
9854 | Show the directory @value{GDBN} searches for separate debugging | |
9855 | information files. | |
9856 | ||
9857 | @end table | |
9858 | ||
9859 | @cindex @code{.gnu_debuglink} sections | |
9860 | @cindex debug links | |
9861 | A debug link is a special section of the executable file named | |
9862 | @code{.gnu_debuglink}. The section must contain: | |
9863 | ||
9864 | @itemize | |
9865 | @item | |
9866 | A filename, with any leading directory components removed, followed by | |
9867 | a zero byte, | |
9868 | @item | |
9869 | zero to three bytes of padding, as needed to reach the next four-byte | |
9870 | boundary within the section, and | |
9871 | @item | |
9872 | a four-byte CRC checksum, stored in the same endianness used for the | |
9873 | executable file itself. The checksum is computed on the debugging | |
9874 | information file's full contents by the function given below, passing | |
9875 | zero as the @var{crc} argument. | |
9876 | @end itemize | |
9877 | ||
9878 | Any executable file format can carry a debug link, as long as it can | |
9879 | contain a section named @code{.gnu_debuglink} with the contents | |
9880 | described above. | |
9881 | ||
9882 | The debugging information file itself should be an ordinary | |
9883 | executable, containing a full set of linker symbols, sections, and | |
9884 | debugging information. The sections of the debugging information file | |
9885 | should have the same names, addresses and sizes as the original file, | |
9886 | but they need not contain any data --- much like a @code{.bss} section | |
9887 | in an ordinary executable. | |
9888 | ||
9889 | As of December 2002, there is no standard GNU utility to produce | |
9890 | separated executable / debugging information file pairs. Ulrich | |
9891 | Drepper's @file{elfutils} package, starting with version 0.53, | |
9892 | contains a version of the @code{strip} command such that the command | |
9893 | @kbd{strip foo -f foo.debug} removes the debugging information from | |
9894 | the executable file @file{foo}, places it in the file | |
9895 | @file{foo.debug}, and leaves behind a debug link in @file{foo}. | |
9896 | ||
9897 | Since there are many different ways to compute CRC's (different | |
9898 | polynomials, reversals, byte ordering, etc.), the simplest way to | |
9899 | describe the CRC used in @code{.gnu_debuglink} sections is to give the | |
9900 | complete code for a function that computes it: | |
9901 | ||
9902 | @kindex @code{gnu_debuglink_crc32} | |
9903 | @smallexample | |
9904 | unsigned long | |
9905 | gnu_debuglink_crc32 (unsigned long crc, | |
9906 | unsigned char *buf, size_t len) | |
9907 | @{ | |
9908 | static const unsigned long crc32_table[256] = | |
9909 | @{ | |
9910 | 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, | |
9911 | 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, | |
9912 | 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, | |
9913 | 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, | |
9914 | 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, | |
9915 | 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, | |
9916 | 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, | |
9917 | 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, | |
9918 | 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, | |
9919 | 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, | |
9920 | 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, | |
9921 | 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, | |
9922 | 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, | |
9923 | 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, | |
9924 | 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, | |
9925 | 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, | |
9926 | 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, | |
9927 | 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, | |
9928 | 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, | |
9929 | 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, | |
9930 | 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, | |
9931 | 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, | |
9932 | 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, | |
9933 | 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, | |
9934 | 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, | |
9935 | 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, | |
9936 | 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, | |
9937 | 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, | |
9938 | 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, | |
9939 | 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, | |
9940 | 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, | |
9941 | 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, | |
9942 | 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, | |
9943 | 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, | |
9944 | 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, | |
9945 | 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, | |
9946 | 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, | |
9947 | 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, | |
9948 | 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, | |
9949 | 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, | |
9950 | 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, | |
9951 | 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, | |
9952 | 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, | |
9953 | 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, | |
9954 | 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, | |
9955 | 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, | |
9956 | 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, | |
9957 | 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, | |
9958 | 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, | |
9959 | 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, | |
9960 | 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, | |
9961 | 0x2d02ef8d | |
9962 | @}; | |
9963 | unsigned char *end; | |
9964 | ||
9965 | crc = ~crc & 0xffffffff; | |
9966 | for (end = buf + len; buf < end; ++buf) | |
9967 | crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); | |
9968 | return ~crc & 0xffffffff;; | |
9969 | @} | |
9970 | @end smallexample | |
9971 | ||
9972 | ||
6d2ebf8b | 9973 | @node Symbol Errors |
c906108c SS |
9974 | @section Errors reading symbol files |
9975 | ||
9976 | While reading a symbol file, @value{GDBN} occasionally encounters problems, | |
9977 | such as symbol types it does not recognize, or known bugs in compiler | |
9978 | output. By default, @value{GDBN} does not notify you of such problems, since | |
9979 | they are relatively common and primarily of interest to people | |
9980 | debugging compilers. If you are interested in seeing information | |
9981 | about ill-constructed symbol tables, you can either ask @value{GDBN} to print | |
9982 | only one message about each such type of problem, no matter how many | |
9983 | times the problem occurs; or you can ask @value{GDBN} to print more messages, | |
9984 | to see how many times the problems occur, with the @code{set | |
9985 | complaints} command (@pxref{Messages/Warnings, ,Optional warnings and | |
9986 | messages}). | |
9987 | ||
9988 | The messages currently printed, and their meanings, include: | |
9989 | ||
9990 | @table @code | |
9991 | @item inner block not inside outer block in @var{symbol} | |
9992 | ||
9993 | The symbol information shows where symbol scopes begin and end | |
9994 | (such as at the start of a function or a block of statements). This | |
9995 | error indicates that an inner scope block is not fully contained | |
9996 | in its outer scope blocks. | |
9997 | ||
9998 | @value{GDBN} circumvents the problem by treating the inner block as if it had | |
9999 | the same scope as the outer block. In the error message, @var{symbol} | |
10000 | may be shown as ``@code{(don't know)}'' if the outer block is not a | |
10001 | function. | |
10002 | ||
10003 | @item block at @var{address} out of order | |
10004 | ||
10005 | The symbol information for symbol scope blocks should occur in | |
10006 | order of increasing addresses. This error indicates that it does not | |
10007 | do so. | |
10008 | ||
10009 | @value{GDBN} does not circumvent this problem, and has trouble | |
10010 | locating symbols in the source file whose symbols it is reading. (You | |
10011 | can often determine what source file is affected by specifying | |
10012 | @code{set verbose on}. @xref{Messages/Warnings, ,Optional warnings and | |
10013 | messages}.) | |
10014 | ||
10015 | @item bad block start address patched | |
10016 | ||
10017 | The symbol information for a symbol scope block has a start address | |
10018 | smaller than the address of the preceding source line. This is known | |
10019 | to occur in the SunOS 4.1.1 (and earlier) C compiler. | |
10020 | ||
10021 | @value{GDBN} circumvents the problem by treating the symbol scope block as | |
10022 | starting on the previous source line. | |
10023 | ||
10024 | @item bad string table offset in symbol @var{n} | |
10025 | ||
10026 | @cindex foo | |
10027 | Symbol number @var{n} contains a pointer into the string table which is | |
10028 | larger than the size of the string table. | |
10029 | ||
10030 | @value{GDBN} circumvents the problem by considering the symbol to have the | |
10031 | name @code{foo}, which may cause other problems if many symbols end up | |
10032 | with this name. | |
10033 | ||
10034 | @item unknown symbol type @code{0x@var{nn}} | |
10035 | ||
7a292a7a SS |
10036 | The symbol information contains new data types that @value{GDBN} does |
10037 | not yet know how to read. @code{0x@var{nn}} is the symbol type of the | |
d4f3574e | 10038 | uncomprehended information, in hexadecimal. |
c906108c | 10039 | |
7a292a7a SS |
10040 | @value{GDBN} circumvents the error by ignoring this symbol information. |
10041 | This usually allows you to debug your program, though certain symbols | |
c906108c | 10042 | are not accessible. If you encounter such a problem and feel like |
7a292a7a SS |
10043 | debugging it, you can debug @code{@value{GDBP}} with itself, breakpoint |
10044 | on @code{complain}, then go up to the function @code{read_dbx_symtab} | |
10045 | and examine @code{*bufp} to see the symbol. | |
c906108c SS |
10046 | |
10047 | @item stub type has NULL name | |
c906108c | 10048 | |
7a292a7a | 10049 | @value{GDBN} could not find the full definition for a struct or class. |
c906108c | 10050 | |
7a292a7a | 10051 | @item const/volatile indicator missing (ok if using g++ v1.x), got@dots{} |
b37052ae | 10052 | The symbol information for a C@t{++} member function is missing some |
7a292a7a SS |
10053 | information that recent versions of the compiler should have output for |
10054 | it. | |
c906108c SS |
10055 | |
10056 | @item info mismatch between compiler and debugger | |
10057 | ||
10058 | @value{GDBN} could not parse a type specification output by the compiler. | |
7a292a7a | 10059 | |
c906108c SS |
10060 | @end table |
10061 | ||
6d2ebf8b | 10062 | @node Targets |
c906108c | 10063 | @chapter Specifying a Debugging Target |
7a292a7a | 10064 | |
c906108c SS |
10065 | @cindex debugging target |
10066 | @kindex target | |
10067 | ||
10068 | A @dfn{target} is the execution environment occupied by your program. | |
53a5351d JM |
10069 | |
10070 | Often, @value{GDBN} runs in the same host environment as your program; | |
10071 | in that case, the debugging target is specified as a side effect when | |
10072 | you use the @code{file} or @code{core} commands. When you need more | |
c906108c SS |
10073 | flexibility---for example, running @value{GDBN} on a physically separate |
10074 | host, or controlling a standalone system over a serial port or a | |
53a5351d JM |
10075 | realtime system over a TCP/IP connection---you can use the @code{target} |
10076 | command to specify one of the target types configured for @value{GDBN} | |
10077 | (@pxref{Target Commands, ,Commands for managing targets}). | |
c906108c SS |
10078 | |
10079 | @menu | |
10080 | * Active Targets:: Active targets | |
10081 | * Target Commands:: Commands for managing targets | |
c906108c SS |
10082 | * Byte Order:: Choosing target byte order |
10083 | * Remote:: Remote debugging | |
96baa820 | 10084 | * KOD:: Kernel Object Display |
c906108c SS |
10085 | |
10086 | @end menu | |
10087 | ||
6d2ebf8b | 10088 | @node Active Targets |
c906108c | 10089 | @section Active targets |
7a292a7a | 10090 | |
c906108c SS |
10091 | @cindex stacking targets |
10092 | @cindex active targets | |
10093 | @cindex multiple targets | |
10094 | ||
c906108c | 10095 | There are three classes of targets: processes, core files, and |
7a292a7a SS |
10096 | executable files. @value{GDBN} can work concurrently on up to three |
10097 | active targets, one in each class. This allows you to (for example) | |
10098 | start a process and inspect its activity without abandoning your work on | |
10099 | a core file. | |
c906108c SS |
10100 | |
10101 | For example, if you execute @samp{gdb a.out}, then the executable file | |
10102 | @code{a.out} is the only active target. If you designate a core file as | |
10103 | well---presumably from a prior run that crashed and coredumped---then | |
10104 | @value{GDBN} has two active targets and uses them in tandem, looking | |
10105 | first in the corefile target, then in the executable file, to satisfy | |
10106 | requests for memory addresses. (Typically, these two classes of target | |
10107 | are complementary, since core files contain only a program's | |
10108 | read-write memory---variables and so on---plus machine status, while | |
10109 | executable files contain only the program text and initialized data.) | |
c906108c SS |
10110 | |
10111 | When you type @code{run}, your executable file becomes an active process | |
7a292a7a SS |
10112 | target as well. When a process target is active, all @value{GDBN} |
10113 | commands requesting memory addresses refer to that target; addresses in | |
10114 | an active core file or executable file target are obscured while the | |
10115 | process target is active. | |
c906108c | 10116 | |
7a292a7a SS |
10117 | Use the @code{core-file} and @code{exec-file} commands to select a new |
10118 | core file or executable target (@pxref{Files, ,Commands to specify | |
c906108c | 10119 | files}). To specify as a target a process that is already running, use |
7a292a7a SS |
10120 | the @code{attach} command (@pxref{Attach, ,Debugging an already-running |
10121 | process}). | |
c906108c | 10122 | |
6d2ebf8b | 10123 | @node Target Commands |
c906108c SS |
10124 | @section Commands for managing targets |
10125 | ||
10126 | @table @code | |
10127 | @item target @var{type} @var{parameters} | |
7a292a7a SS |
10128 | Connects the @value{GDBN} host environment to a target machine or |
10129 | process. A target is typically a protocol for talking to debugging | |
10130 | facilities. You use the argument @var{type} to specify the type or | |
10131 | protocol of the target machine. | |
c906108c SS |
10132 | |
10133 | Further @var{parameters} are interpreted by the target protocol, but | |
10134 | typically include things like device names or host names to connect | |
10135 | with, process numbers, and baud rates. | |
c906108c SS |
10136 | |
10137 | The @code{target} command does not repeat if you press @key{RET} again | |
10138 | after executing the command. | |
10139 | ||
10140 | @kindex help target | |
10141 | @item help target | |
10142 | Displays the names of all targets available. To display targets | |
10143 | currently selected, use either @code{info target} or @code{info files} | |
10144 | (@pxref{Files, ,Commands to specify files}). | |
10145 | ||
10146 | @item help target @var{name} | |
10147 | Describe a particular target, including any parameters necessary to | |
10148 | select it. | |
10149 | ||
10150 | @kindex set gnutarget | |
10151 | @item set gnutarget @var{args} | |
5d161b24 | 10152 | @value{GDBN} uses its own library BFD to read your files. @value{GDBN} |
c906108c | 10153 | knows whether it is reading an @dfn{executable}, |
5d161b24 DB |
10154 | a @dfn{core}, or a @dfn{.o} file; however, you can specify the file format |
10155 | with the @code{set gnutarget} command. Unlike most @code{target} commands, | |
c906108c SS |
10156 | with @code{gnutarget} the @code{target} refers to a program, not a machine. |
10157 | ||
d4f3574e | 10158 | @quotation |
c906108c SS |
10159 | @emph{Warning:} To specify a file format with @code{set gnutarget}, |
10160 | you must know the actual BFD name. | |
d4f3574e | 10161 | @end quotation |
c906108c | 10162 | |
d4f3574e SS |
10163 | @noindent |
10164 | @xref{Files, , Commands to specify files}. | |
c906108c | 10165 | |
5d161b24 | 10166 | @kindex show gnutarget |
c906108c SS |
10167 | @item show gnutarget |
10168 | Use the @code{show gnutarget} command to display what file format | |
10169 | @code{gnutarget} is set to read. If you have not set @code{gnutarget}, | |
10170 | @value{GDBN} will determine the file format for each file automatically, | |
10171 | and @code{show gnutarget} displays @samp{The current BDF target is "auto"}. | |
10172 | @end table | |
10173 | ||
c906108c SS |
10174 | Here are some common targets (available, or not, depending on the GDB |
10175 | configuration): | |
c906108c SS |
10176 | |
10177 | @table @code | |
10178 | @kindex target exec | |
10179 | @item target exec @var{program} | |
10180 | An executable file. @samp{target exec @var{program}} is the same as | |
10181 | @samp{exec-file @var{program}}. | |
10182 | ||
c906108c SS |
10183 | @kindex target core |
10184 | @item target core @var{filename} | |
10185 | A core dump file. @samp{target core @var{filename}} is the same as | |
10186 | @samp{core-file @var{filename}}. | |
c906108c SS |
10187 | |
10188 | @kindex target remote | |
10189 | @item target remote @var{dev} | |
10190 | Remote serial target in GDB-specific protocol. The argument @var{dev} | |
10191 | specifies what serial device to use for the connection (e.g. | |
10192 | @file{/dev/ttya}). @xref{Remote, ,Remote debugging}. @code{target remote} | |
d4f3574e | 10193 | supports the @code{load} command. This is only useful if you have |
c906108c SS |
10194 | some other way of getting the stub to the target system, and you can put |
10195 | it somewhere in memory where it won't get clobbered by the download. | |
10196 | ||
c906108c SS |
10197 | @kindex target sim |
10198 | @item target sim | |
2df3850c | 10199 | Builtin CPU simulator. @value{GDBN} includes simulators for most architectures. |
104c1213 | 10200 | In general, |
474c8240 | 10201 | @smallexample |
104c1213 JM |
10202 | target sim |
10203 | load | |
10204 | run | |
474c8240 | 10205 | @end smallexample |
d4f3574e | 10206 | @noindent |
104c1213 | 10207 | works; however, you cannot assume that a specific memory map, device |
d4f3574e | 10208 | drivers, or even basic I/O is available, although some simulators do |
104c1213 JM |
10209 | provide these. For info about any processor-specific simulator details, |
10210 | see the appropriate section in @ref{Embedded Processors, ,Embedded | |
10211 | Processors}. | |
10212 | ||
c906108c SS |
10213 | @end table |
10214 | ||
104c1213 | 10215 | Some configurations may include these targets as well: |
c906108c SS |
10216 | |
10217 | @table @code | |
10218 | ||
c906108c SS |
10219 | @kindex target nrom |
10220 | @item target nrom @var{dev} | |
10221 | NetROM ROM emulator. This target only supports downloading. | |
10222 | ||
c906108c SS |
10223 | @end table |
10224 | ||
5d161b24 | 10225 | Different targets are available on different configurations of @value{GDBN}; |
c906108c | 10226 | your configuration may have more or fewer targets. |
c906108c SS |
10227 | |
10228 | Many remote targets require you to download the executable's code | |
10229 | once you've successfully established a connection. | |
10230 | ||
10231 | @table @code | |
10232 | ||
10233 | @kindex load @var{filename} | |
10234 | @item load @var{filename} | |
c906108c SS |
10235 | Depending on what remote debugging facilities are configured into |
10236 | @value{GDBN}, the @code{load} command may be available. Where it exists, it | |
10237 | is meant to make @var{filename} (an executable) available for debugging | |
10238 | on the remote system---by downloading, or dynamic linking, for example. | |
10239 | @code{load} also records the @var{filename} symbol table in @value{GDBN}, like | |
10240 | the @code{add-symbol-file} command. | |
10241 | ||
10242 | If your @value{GDBN} does not have a @code{load} command, attempting to | |
10243 | execute it gets the error message ``@code{You can't do that when your | |
10244 | target is @dots{}}'' | |
c906108c SS |
10245 | |
10246 | The file is loaded at whatever address is specified in the executable. | |
10247 | For some object file formats, you can specify the load address when you | |
10248 | link the program; for other formats, like a.out, the object file format | |
10249 | specifies a fixed address. | |
10250 | @c FIXME! This would be a good place for an xref to the GNU linker doc. | |
10251 | ||
c906108c SS |
10252 | @code{load} does not repeat if you press @key{RET} again after using it. |
10253 | @end table | |
10254 | ||
6d2ebf8b | 10255 | @node Byte Order |
c906108c | 10256 | @section Choosing target byte order |
7a292a7a | 10257 | |
c906108c SS |
10258 | @cindex choosing target byte order |
10259 | @cindex target byte order | |
c906108c SS |
10260 | |
10261 | Some types of processors, such as the MIPS, PowerPC, and Hitachi SH, | |
10262 | offer the ability to run either big-endian or little-endian byte | |
10263 | orders. Usually the executable or symbol will include a bit to | |
10264 | designate the endian-ness, and you will not need to worry about | |
10265 | which to use. However, you may still find it useful to adjust | |
d4f3574e | 10266 | @value{GDBN}'s idea of processor endian-ness manually. |
c906108c SS |
10267 | |
10268 | @table @code | |
10269 | @kindex set endian big | |
10270 | @item set endian big | |
10271 | Instruct @value{GDBN} to assume the target is big-endian. | |
10272 | ||
10273 | @kindex set endian little | |
10274 | @item set endian little | |
10275 | Instruct @value{GDBN} to assume the target is little-endian. | |
10276 | ||
10277 | @kindex set endian auto | |
10278 | @item set endian auto | |
10279 | Instruct @value{GDBN} to use the byte order associated with the | |
10280 | executable. | |
10281 | ||
10282 | @item show endian | |
10283 | Display @value{GDBN}'s current idea of the target byte order. | |
10284 | ||
10285 | @end table | |
10286 | ||
10287 | Note that these commands merely adjust interpretation of symbolic | |
10288 | data on the host, and that they have absolutely no effect on the | |
10289 | target system. | |
10290 | ||
6d2ebf8b | 10291 | @node Remote |
c906108c SS |
10292 | @section Remote debugging |
10293 | @cindex remote debugging | |
10294 | ||
10295 | If you are trying to debug a program running on a machine that cannot run | |
5d161b24 DB |
10296 | @value{GDBN} in the usual way, it is often useful to use remote debugging. |
10297 | For example, you might use remote debugging on an operating system kernel, | |
c906108c SS |
10298 | or on a small system which does not have a general purpose operating system |
10299 | powerful enough to run a full-featured debugger. | |
10300 | ||
10301 | Some configurations of @value{GDBN} have special serial or TCP/IP interfaces | |
10302 | to make this work with particular debugging targets. In addition, | |
5d161b24 | 10303 | @value{GDBN} comes with a generic serial protocol (specific to @value{GDBN}, |
c906108c SS |
10304 | but not specific to any particular target system) which you can use if you |
10305 | write the remote stubs---the code that runs on the remote system to | |
10306 | communicate with @value{GDBN}. | |
10307 | ||
10308 | Other remote targets may be available in your | |
10309 | configuration of @value{GDBN}; use @code{help target} to list them. | |
c906108c | 10310 | |
6f05cf9f AC |
10311 | @node KOD |
10312 | @section Kernel Object Display | |
10313 | ||
10314 | @cindex kernel object display | |
10315 | @cindex kernel object | |
10316 | @cindex KOD | |
10317 | ||
10318 | Some targets support kernel object display. Using this facility, | |
10319 | @value{GDBN} communicates specially with the underlying operating system | |
10320 | and can display information about operating system-level objects such as | |
10321 | mutexes and other synchronization objects. Exactly which objects can be | |
10322 | displayed is determined on a per-OS basis. | |
10323 | ||
10324 | Use the @code{set os} command to set the operating system. This tells | |
10325 | @value{GDBN} which kernel object display module to initialize: | |
10326 | ||
474c8240 | 10327 | @smallexample |
6f05cf9f | 10328 | (@value{GDBP}) set os cisco |
474c8240 | 10329 | @end smallexample |
6f05cf9f AC |
10330 | |
10331 | If @code{set os} succeeds, @value{GDBN} will display some information | |
10332 | about the operating system, and will create a new @code{info} command | |
10333 | which can be used to query the target. The @code{info} command is named | |
10334 | after the operating system: | |
c906108c | 10335 | |
474c8240 | 10336 | @smallexample |
6f05cf9f AC |
10337 | (@value{GDBP}) info cisco |
10338 | List of Cisco Kernel Objects | |
10339 | Object Description | |
10340 | any Any and all objects | |
474c8240 | 10341 | @end smallexample |
6f05cf9f AC |
10342 | |
10343 | Further subcommands can be used to query about particular objects known | |
10344 | by the kernel. | |
10345 | ||
10346 | There is currently no way to determine whether a given operating system | |
10347 | is supported other than to try it. | |
10348 | ||
10349 | ||
10350 | @node Remote Debugging | |
10351 | @chapter Debugging remote programs | |
10352 | ||
6b2f586d AC |
10353 | @menu |
10354 | * Server:: Using the gdbserver program | |
10355 | * NetWare:: Using the gdbserve.nlm program | |
501eef12 | 10356 | * Remote configuration:: Remote configuration |
6b2f586d | 10357 | * remote stub:: Implementing a remote stub |
6b2f586d AC |
10358 | @end menu |
10359 | ||
6f05cf9f AC |
10360 | @node Server |
10361 | @section Using the @code{gdbserver} program | |
10362 | ||
10363 | @kindex gdbserver | |
10364 | @cindex remote connection without stubs | |
10365 | @code{gdbserver} is a control program for Unix-like systems, which | |
10366 | allows you to connect your program with a remote @value{GDBN} via | |
10367 | @code{target remote}---but without linking in the usual debugging stub. | |
10368 | ||
10369 | @code{gdbserver} is not a complete replacement for the debugging stubs, | |
10370 | because it requires essentially the same operating-system facilities | |
10371 | that @value{GDBN} itself does. In fact, a system that can run | |
10372 | @code{gdbserver} to connect to a remote @value{GDBN} could also run | |
10373 | @value{GDBN} locally! @code{gdbserver} is sometimes useful nevertheless, | |
10374 | because it is a much smaller program than @value{GDBN} itself. It is | |
10375 | also easier to port than all of @value{GDBN}, so you may be able to get | |
10376 | started more quickly on a new system by using @code{gdbserver}. | |
10377 | Finally, if you develop code for real-time systems, you may find that | |
10378 | the tradeoffs involved in real-time operation make it more convenient to | |
10379 | do as much development work as possible on another system, for example | |
10380 | by cross-compiling. You can use @code{gdbserver} to make a similar | |
10381 | choice for debugging. | |
10382 | ||
10383 | @value{GDBN} and @code{gdbserver} communicate via either a serial line | |
10384 | or a TCP connection, using the standard @value{GDBN} remote serial | |
10385 | protocol. | |
10386 | ||
10387 | @table @emph | |
10388 | @item On the target machine, | |
10389 | you need to have a copy of the program you want to debug. | |
10390 | @code{gdbserver} does not need your program's symbol table, so you can | |
10391 | strip the program if necessary to save space. @value{GDBN} on the host | |
10392 | system does all the symbol handling. | |
10393 | ||
10394 | To use the server, you must tell it how to communicate with @value{GDBN}; | |
56460a61 | 10395 | the name of your program; and the arguments for your program. The usual |
6f05cf9f AC |
10396 | syntax is: |
10397 | ||
10398 | @smallexample | |
10399 | target> gdbserver @var{comm} @var{program} [ @var{args} @dots{} ] | |
10400 | @end smallexample | |
10401 | ||
10402 | @var{comm} is either a device name (to use a serial line) or a TCP | |
10403 | hostname and portnumber. For example, to debug Emacs with the argument | |
10404 | @samp{foo.txt} and communicate with @value{GDBN} over the serial port | |
10405 | @file{/dev/com1}: | |
10406 | ||
10407 | @smallexample | |
10408 | target> gdbserver /dev/com1 emacs foo.txt | |
10409 | @end smallexample | |
10410 | ||
10411 | @code{gdbserver} waits passively for the host @value{GDBN} to communicate | |
10412 | with it. | |
10413 | ||
10414 | To use a TCP connection instead of a serial line: | |
10415 | ||
10416 | @smallexample | |
10417 | target> gdbserver host:2345 emacs foo.txt | |
10418 | @end smallexample | |
10419 | ||
10420 | The only difference from the previous example is the first argument, | |
10421 | specifying that you are communicating with the host @value{GDBN} via | |
10422 | TCP. The @samp{host:2345} argument means that @code{gdbserver} is to | |
10423 | expect a TCP connection from machine @samp{host} to local TCP port 2345. | |
10424 | (Currently, the @samp{host} part is ignored.) You can choose any number | |
10425 | you want for the port number as long as it does not conflict with any | |
10426 | TCP ports already in use on the target system (for example, @code{23} is | |
10427 | reserved for @code{telnet}).@footnote{If you choose a port number that | |
10428 | conflicts with another service, @code{gdbserver} prints an error message | |
10429 | and exits.} You must use the same port number with the host @value{GDBN} | |
10430 | @code{target remote} command. | |
10431 | ||
56460a61 DJ |
10432 | On some targets, @code{gdbserver} can also attach to running programs. |
10433 | This is accomplished via the @code{--attach} argument. The syntax is: | |
10434 | ||
10435 | @smallexample | |
10436 | target> gdbserver @var{comm} --attach @var{pid} | |
10437 | @end smallexample | |
10438 | ||
10439 | @var{pid} is the process ID of a currently running process. It isn't necessary | |
10440 | to point @code{gdbserver} at a binary for the running process. | |
10441 | ||
6f05cf9f AC |
10442 | @item On the @value{GDBN} host machine, |
10443 | you need an unstripped copy of your program, since @value{GDBN} needs | |
10444 | symbols and debugging information. Start up @value{GDBN} as usual, | |
10445 | using the name of the local copy of your program as the first argument. | |
10446 | (You may also need the @w{@samp{--baud}} option if the serial line is | |
10447 | running at anything other than 9600@dmn{bps}.) After that, use @code{target | |
10448 | remote} to establish communications with @code{gdbserver}. Its argument | |
10449 | is either a device name (usually a serial device, like | |
10450 | @file{/dev/ttyb}), or a TCP port descriptor in the form | |
10451 | @code{@var{host}:@var{PORT}}. For example: | |
10452 | ||
10453 | @smallexample | |
10454 | (@value{GDBP}) target remote /dev/ttyb | |
10455 | @end smallexample | |
10456 | ||
10457 | @noindent | |
10458 | communicates with the server via serial line @file{/dev/ttyb}, and | |
10459 | ||
10460 | @smallexample | |
10461 | (@value{GDBP}) target remote the-target:2345 | |
10462 | @end smallexample | |
10463 | ||
10464 | @noindent | |
10465 | communicates via a TCP connection to port 2345 on host @w{@file{the-target}}. | |
10466 | For TCP connections, you must start up @code{gdbserver} prior to using | |
10467 | the @code{target remote} command. Otherwise you may get an error whose | |
10468 | text depends on the host system, but which usually looks something like | |
10469 | @samp{Connection refused}. | |
10470 | @end table | |
10471 | ||
10472 | @node NetWare | |
10473 | @section Using the @code{gdbserve.nlm} program | |
10474 | ||
10475 | @kindex gdbserve.nlm | |
10476 | @code{gdbserve.nlm} is a control program for NetWare systems, which | |
10477 | allows you to connect your program with a remote @value{GDBN} via | |
10478 | @code{target remote}. | |
10479 | ||
10480 | @value{GDBN} and @code{gdbserve.nlm} communicate via a serial line, | |
10481 | using the standard @value{GDBN} remote serial protocol. | |
10482 | ||
10483 | @table @emph | |
10484 | @item On the target machine, | |
10485 | you need to have a copy of the program you want to debug. | |
10486 | @code{gdbserve.nlm} does not need your program's symbol table, so you | |
10487 | can strip the program if necessary to save space. @value{GDBN} on the | |
10488 | host system does all the symbol handling. | |
10489 | ||
10490 | To use the server, you must tell it how to communicate with | |
10491 | @value{GDBN}; the name of your program; and the arguments for your | |
10492 | program. The syntax is: | |
10493 | ||
10494 | @smallexample | |
10495 | load gdbserve [ BOARD=@var{board} ] [ PORT=@var{port} ] | |
10496 | [ BAUD=@var{baud} ] @var{program} [ @var{args} @dots{} ] | |
10497 | @end smallexample | |
10498 | ||
10499 | @var{board} and @var{port} specify the serial line; @var{baud} specifies | |
10500 | the baud rate used by the connection. @var{port} and @var{node} default | |
10501 | to 0, @var{baud} defaults to 9600@dmn{bps}. | |
10502 | ||
10503 | For example, to debug Emacs with the argument @samp{foo.txt}and | |
10504 | communicate with @value{GDBN} over serial port number 2 or board 1 | |
10505 | using a 19200@dmn{bps} connection: | |
10506 | ||
10507 | @smallexample | |
10508 | load gdbserve BOARD=1 PORT=2 BAUD=19200 emacs foo.txt | |
10509 | @end smallexample | |
10510 | ||
10511 | @item On the @value{GDBN} host machine, | |
10512 | you need an unstripped copy of your program, since @value{GDBN} needs | |
10513 | symbols and debugging information. Start up @value{GDBN} as usual, | |
10514 | using the name of the local copy of your program as the first argument. | |
10515 | (You may also need the @w{@samp{--baud}} option if the serial line is | |
10516 | running at anything other than 9600@dmn{bps}. After that, use @code{target | |
10517 | remote} to establish communications with @code{gdbserve.nlm}. Its | |
10518 | argument is a device name (usually a serial device, like | |
10519 | @file{/dev/ttyb}). For example: | |
10520 | ||
10521 | @smallexample | |
10522 | (@value{GDBP}) target remote /dev/ttyb | |
10523 | @end smallexample | |
10524 | ||
10525 | @noindent | |
10526 | communications with the server via serial line @file{/dev/ttyb}. | |
10527 | @end table | |
10528 | ||
501eef12 AC |
10529 | @node Remote configuration |
10530 | @section Remote configuration | |
10531 | ||
10532 | The following configuration options are available when debugging remote | |
10533 | programs: | |
10534 | ||
10535 | @table @code | |
10536 | @kindex set remote hardware-watchpoint-limit | |
10537 | @kindex set remote hardware-breakpoint-limit | |
10538 | @anchor{set remote hardware-watchpoint-limit} | |
10539 | @anchor{set remote hardware-breakpoint-limit} | |
10540 | @item set remote hardware-watchpoint-limit @var{limit} | |
10541 | @itemx set remote hardware-breakpoint-limit @var{limit} | |
10542 | Restrict @value{GDBN} to using @var{limit} remote hardware breakpoint or | |
10543 | watchpoints. A limit of -1, the default, is treated as unlimited. | |
10544 | @end table | |
10545 | ||
6f05cf9f AC |
10546 | @node remote stub |
10547 | @section Implementing a remote stub | |
7a292a7a | 10548 | |
8e04817f AC |
10549 | @cindex debugging stub, example |
10550 | @cindex remote stub, example | |
10551 | @cindex stub example, remote debugging | |
10552 | The stub files provided with @value{GDBN} implement the target side of the | |
10553 | communication protocol, and the @value{GDBN} side is implemented in the | |
10554 | @value{GDBN} source file @file{remote.c}. Normally, you can simply allow | |
10555 | these subroutines to communicate, and ignore the details. (If you're | |
10556 | implementing your own stub file, you can still ignore the details: start | |
10557 | with one of the existing stub files. @file{sparc-stub.c} is the best | |
10558 | organized, and therefore the easiest to read.) | |
10559 | ||
104c1213 JM |
10560 | @cindex remote serial debugging, overview |
10561 | To debug a program running on another machine (the debugging | |
10562 | @dfn{target} machine), you must first arrange for all the usual | |
10563 | prerequisites for the program to run by itself. For example, for a C | |
10564 | program, you need: | |
c906108c | 10565 | |
104c1213 JM |
10566 | @enumerate |
10567 | @item | |
10568 | A startup routine to set up the C runtime environment; these usually | |
10569 | have a name like @file{crt0}. The startup routine may be supplied by | |
10570 | your hardware supplier, or you may have to write your own. | |
96baa820 | 10571 | |
5d161b24 | 10572 | @item |
d4f3574e | 10573 | A C subroutine library to support your program's |
104c1213 | 10574 | subroutine calls, notably managing input and output. |
96baa820 | 10575 | |
104c1213 JM |
10576 | @item |
10577 | A way of getting your program to the other machine---for example, a | |
10578 | download program. These are often supplied by the hardware | |
10579 | manufacturer, but you may have to write your own from hardware | |
10580 | documentation. | |
10581 | @end enumerate | |
96baa820 | 10582 | |
104c1213 JM |
10583 | The next step is to arrange for your program to use a serial port to |
10584 | communicate with the machine where @value{GDBN} is running (the @dfn{host} | |
10585 | machine). In general terms, the scheme looks like this: | |
96baa820 | 10586 | |
104c1213 JM |
10587 | @table @emph |
10588 | @item On the host, | |
10589 | @value{GDBN} already understands how to use this protocol; when everything | |
10590 | else is set up, you can simply use the @samp{target remote} command | |
10591 | (@pxref{Targets,,Specifying a Debugging Target}). | |
10592 | ||
10593 | @item On the target, | |
10594 | you must link with your program a few special-purpose subroutines that | |
10595 | implement the @value{GDBN} remote serial protocol. The file containing these | |
10596 | subroutines is called a @dfn{debugging stub}. | |
10597 | ||
10598 | On certain remote targets, you can use an auxiliary program | |
10599 | @code{gdbserver} instead of linking a stub into your program. | |
10600 | @xref{Server,,Using the @code{gdbserver} program}, for details. | |
10601 | @end table | |
96baa820 | 10602 | |
104c1213 JM |
10603 | The debugging stub is specific to the architecture of the remote |
10604 | machine; for example, use @file{sparc-stub.c} to debug programs on | |
10605 | @sc{sparc} boards. | |
96baa820 | 10606 | |
104c1213 JM |
10607 | @cindex remote serial stub list |
10608 | These working remote stubs are distributed with @value{GDBN}: | |
96baa820 | 10609 | |
104c1213 JM |
10610 | @table @code |
10611 | ||
10612 | @item i386-stub.c | |
41afff9a | 10613 | @cindex @file{i386-stub.c} |
104c1213 JM |
10614 | @cindex Intel |
10615 | @cindex i386 | |
10616 | For Intel 386 and compatible architectures. | |
10617 | ||
10618 | @item m68k-stub.c | |
41afff9a | 10619 | @cindex @file{m68k-stub.c} |
104c1213 JM |
10620 | @cindex Motorola 680x0 |
10621 | @cindex m680x0 | |
10622 | For Motorola 680x0 architectures. | |
10623 | ||
10624 | @item sh-stub.c | |
41afff9a | 10625 | @cindex @file{sh-stub.c} |
104c1213 JM |
10626 | @cindex Hitachi |
10627 | @cindex SH | |
10628 | For Hitachi SH architectures. | |
10629 | ||
10630 | @item sparc-stub.c | |
41afff9a | 10631 | @cindex @file{sparc-stub.c} |
104c1213 JM |
10632 | @cindex Sparc |
10633 | For @sc{sparc} architectures. | |
10634 | ||
10635 | @item sparcl-stub.c | |
41afff9a | 10636 | @cindex @file{sparcl-stub.c} |
104c1213 JM |
10637 | @cindex Fujitsu |
10638 | @cindex SparcLite | |
10639 | For Fujitsu @sc{sparclite} architectures. | |
10640 | ||
10641 | @end table | |
10642 | ||
10643 | The @file{README} file in the @value{GDBN} distribution may list other | |
10644 | recently added stubs. | |
10645 | ||
10646 | @menu | |
10647 | * Stub Contents:: What the stub can do for you | |
10648 | * Bootstrapping:: What you must do for the stub | |
10649 | * Debug Session:: Putting it all together | |
104c1213 JM |
10650 | @end menu |
10651 | ||
6d2ebf8b | 10652 | @node Stub Contents |
6f05cf9f | 10653 | @subsection What the stub can do for you |
104c1213 JM |
10654 | |
10655 | @cindex remote serial stub | |
10656 | The debugging stub for your architecture supplies these three | |
10657 | subroutines: | |
10658 | ||
10659 | @table @code | |
10660 | @item set_debug_traps | |
10661 | @kindex set_debug_traps | |
10662 | @cindex remote serial stub, initialization | |
10663 | This routine arranges for @code{handle_exception} to run when your | |
10664 | program stops. You must call this subroutine explicitly near the | |
10665 | beginning of your program. | |
10666 | ||
10667 | @item handle_exception | |
10668 | @kindex handle_exception | |
10669 | @cindex remote serial stub, main routine | |
10670 | This is the central workhorse, but your program never calls it | |
10671 | explicitly---the setup code arranges for @code{handle_exception} to | |
10672 | run when a trap is triggered. | |
10673 | ||
10674 | @code{handle_exception} takes control when your program stops during | |
10675 | execution (for example, on a breakpoint), and mediates communications | |
10676 | with @value{GDBN} on the host machine. This is where the communications | |
10677 | protocol is implemented; @code{handle_exception} acts as the @value{GDBN} | |
d4f3574e | 10678 | representative on the target machine. It begins by sending summary |
104c1213 JM |
10679 | information on the state of your program, then continues to execute, |
10680 | retrieving and transmitting any information @value{GDBN} needs, until you | |
10681 | execute a @value{GDBN} command that makes your program resume; at that point, | |
10682 | @code{handle_exception} returns control to your own code on the target | |
5d161b24 | 10683 | machine. |
104c1213 JM |
10684 | |
10685 | @item breakpoint | |
10686 | @cindex @code{breakpoint} subroutine, remote | |
10687 | Use this auxiliary subroutine to make your program contain a | |
10688 | breakpoint. Depending on the particular situation, this may be the only | |
10689 | way for @value{GDBN} to get control. For instance, if your target | |
10690 | machine has some sort of interrupt button, you won't need to call this; | |
10691 | pressing the interrupt button transfers control to | |
10692 | @code{handle_exception}---in effect, to @value{GDBN}. On some machines, | |
10693 | simply receiving characters on the serial port may also trigger a trap; | |
10694 | again, in that situation, you don't need to call @code{breakpoint} from | |
10695 | your own program---simply running @samp{target remote} from the host | |
5d161b24 | 10696 | @value{GDBN} session gets control. |
104c1213 JM |
10697 | |
10698 | Call @code{breakpoint} if none of these is true, or if you simply want | |
10699 | to make certain your program stops at a predetermined point for the | |
10700 | start of your debugging session. | |
10701 | @end table | |
10702 | ||
6d2ebf8b | 10703 | @node Bootstrapping |
6f05cf9f | 10704 | @subsection What you must do for the stub |
104c1213 JM |
10705 | |
10706 | @cindex remote stub, support routines | |
10707 | The debugging stubs that come with @value{GDBN} are set up for a particular | |
10708 | chip architecture, but they have no information about the rest of your | |
10709 | debugging target machine. | |
10710 | ||
10711 | First of all you need to tell the stub how to communicate with the | |
10712 | serial port. | |
10713 | ||
10714 | @table @code | |
10715 | @item int getDebugChar() | |
10716 | @kindex getDebugChar | |
10717 | Write this subroutine to read a single character from the serial port. | |
10718 | It may be identical to @code{getchar} for your target system; a | |
10719 | different name is used to allow you to distinguish the two if you wish. | |
10720 | ||
10721 | @item void putDebugChar(int) | |
10722 | @kindex putDebugChar | |
10723 | Write this subroutine to write a single character to the serial port. | |
5d161b24 | 10724 | It may be identical to @code{putchar} for your target system; a |
104c1213 JM |
10725 | different name is used to allow you to distinguish the two if you wish. |
10726 | @end table | |
10727 | ||
10728 | @cindex control C, and remote debugging | |
10729 | @cindex interrupting remote targets | |
10730 | If you want @value{GDBN} to be able to stop your program while it is | |
10731 | running, you need to use an interrupt-driven serial driver, and arrange | |
10732 | for it to stop when it receives a @code{^C} (@samp{\003}, the control-C | |
10733 | character). That is the character which @value{GDBN} uses to tell the | |
10734 | remote system to stop. | |
10735 | ||
10736 | Getting the debugging target to return the proper status to @value{GDBN} | |
10737 | probably requires changes to the standard stub; one quick and dirty way | |
10738 | is to just execute a breakpoint instruction (the ``dirty'' part is that | |
10739 | @value{GDBN} reports a @code{SIGTRAP} instead of a @code{SIGINT}). | |
10740 | ||
10741 | Other routines you need to supply are: | |
10742 | ||
10743 | @table @code | |
10744 | @item void exceptionHandler (int @var{exception_number}, void *@var{exception_address}) | |
10745 | @kindex exceptionHandler | |
10746 | Write this function to install @var{exception_address} in the exception | |
10747 | handling tables. You need to do this because the stub does not have any | |
10748 | way of knowing what the exception handling tables on your target system | |
10749 | are like (for example, the processor's table might be in @sc{rom}, | |
10750 | containing entries which point to a table in @sc{ram}). | |
10751 | @var{exception_number} is the exception number which should be changed; | |
10752 | its meaning is architecture-dependent (for example, different numbers | |
10753 | might represent divide by zero, misaligned access, etc). When this | |
10754 | exception occurs, control should be transferred directly to | |
10755 | @var{exception_address}, and the processor state (stack, registers, | |
10756 | and so on) should be just as it is when a processor exception occurs. So if | |
10757 | you want to use a jump instruction to reach @var{exception_address}, it | |
10758 | should be a simple jump, not a jump to subroutine. | |
10759 | ||
10760 | For the 386, @var{exception_address} should be installed as an interrupt | |
10761 | gate so that interrupts are masked while the handler runs. The gate | |
10762 | should be at privilege level 0 (the most privileged level). The | |
10763 | @sc{sparc} and 68k stubs are able to mask interrupts themselves without | |
10764 | help from @code{exceptionHandler}. | |
10765 | ||
10766 | @item void flush_i_cache() | |
10767 | @kindex flush_i_cache | |
d4f3574e | 10768 | On @sc{sparc} and @sc{sparclite} only, write this subroutine to flush the |
104c1213 JM |
10769 | instruction cache, if any, on your target machine. If there is no |
10770 | instruction cache, this subroutine may be a no-op. | |
10771 | ||
10772 | On target machines that have instruction caches, @value{GDBN} requires this | |
10773 | function to make certain that the state of your program is stable. | |
10774 | @end table | |
10775 | ||
10776 | @noindent | |
10777 | You must also make sure this library routine is available: | |
10778 | ||
10779 | @table @code | |
10780 | @item void *memset(void *, int, int) | |
10781 | @kindex memset | |
10782 | This is the standard library function @code{memset} that sets an area of | |
10783 | memory to a known value. If you have one of the free versions of | |
10784 | @code{libc.a}, @code{memset} can be found there; otherwise, you must | |
10785 | either obtain it from your hardware manufacturer, or write your own. | |
10786 | @end table | |
10787 | ||
10788 | If you do not use the GNU C compiler, you may need other standard | |
10789 | library subroutines as well; this varies from one stub to another, | |
10790 | but in general the stubs are likely to use any of the common library | |
d4f3574e | 10791 | subroutines which @code{@value{GCC}} generates as inline code. |
104c1213 JM |
10792 | |
10793 | ||
6d2ebf8b | 10794 | @node Debug Session |
6f05cf9f | 10795 | @subsection Putting it all together |
104c1213 JM |
10796 | |
10797 | @cindex remote serial debugging summary | |
10798 | In summary, when your program is ready to debug, you must follow these | |
10799 | steps. | |
10800 | ||
10801 | @enumerate | |
10802 | @item | |
6d2ebf8b | 10803 | Make sure you have defined the supporting low-level routines |
104c1213 JM |
10804 | (@pxref{Bootstrapping,,What you must do for the stub}): |
10805 | @display | |
10806 | @code{getDebugChar}, @code{putDebugChar}, | |
10807 | @code{flush_i_cache}, @code{memset}, @code{exceptionHandler}. | |
10808 | @end display | |
10809 | ||
10810 | @item | |
10811 | Insert these lines near the top of your program: | |
10812 | ||
474c8240 | 10813 | @smallexample |
104c1213 JM |
10814 | set_debug_traps(); |
10815 | breakpoint(); | |
474c8240 | 10816 | @end smallexample |
104c1213 JM |
10817 | |
10818 | @item | |
10819 | For the 680x0 stub only, you need to provide a variable called | |
10820 | @code{exceptionHook}. Normally you just use: | |
10821 | ||
474c8240 | 10822 | @smallexample |
104c1213 | 10823 | void (*exceptionHook)() = 0; |
474c8240 | 10824 | @end smallexample |
104c1213 | 10825 | |
d4f3574e | 10826 | @noindent |
104c1213 | 10827 | but if before calling @code{set_debug_traps}, you set it to point to a |
598ca718 | 10828 | function in your program, that function is called when |
104c1213 JM |
10829 | @code{@value{GDBN}} continues after stopping on a trap (for example, bus |
10830 | error). The function indicated by @code{exceptionHook} is called with | |
10831 | one parameter: an @code{int} which is the exception number. | |
10832 | ||
10833 | @item | |
10834 | Compile and link together: your program, the @value{GDBN} debugging stub for | |
10835 | your target architecture, and the supporting subroutines. | |
10836 | ||
10837 | @item | |
10838 | Make sure you have a serial connection between your target machine and | |
10839 | the @value{GDBN} host, and identify the serial port on the host. | |
10840 | ||
10841 | @item | |
10842 | @c The "remote" target now provides a `load' command, so we should | |
10843 | @c document that. FIXME. | |
10844 | Download your program to your target machine (or get it there by | |
10845 | whatever means the manufacturer provides), and start it. | |
10846 | ||
10847 | @item | |
10848 | To start remote debugging, run @value{GDBN} on the host machine, and specify | |
10849 | as an executable file the program that is running in the remote machine. | |
10850 | This tells @value{GDBN} how to find your program's symbols and the contents | |
10851 | of its pure text. | |
10852 | ||
d4f3574e | 10853 | @item |
104c1213 | 10854 | @cindex serial line, @code{target remote} |
d4f3574e | 10855 | Establish communication using the @code{target remote} command. |
104c1213 JM |
10856 | Its argument specifies how to communicate with the target |
10857 | machine---either via a devicename attached to a direct serial line, or a | |
9db8d71f | 10858 | TCP or UDP port (usually to a terminal server which in turn has a serial line |
104c1213 JM |
10859 | to the target). For example, to use a serial line connected to the |
10860 | device named @file{/dev/ttyb}: | |
10861 | ||
474c8240 | 10862 | @smallexample |
104c1213 | 10863 | target remote /dev/ttyb |
474c8240 | 10864 | @end smallexample |
104c1213 JM |
10865 | |
10866 | @cindex TCP port, @code{target remote} | |
10867 | To use a TCP connection, use an argument of the form | |
9db8d71f DJ |
10868 | @code{@var{host}:@var{port}} or @code{tcp:@var{host}:@var{port}}. |
10869 | For example, to connect to port 2828 on a | |
104c1213 JM |
10870 | terminal server named @code{manyfarms}: |
10871 | ||
474c8240 | 10872 | @smallexample |
104c1213 | 10873 | target remote manyfarms:2828 |
474c8240 | 10874 | @end smallexample |
a2bea4c3 CV |
10875 | |
10876 | If your remote target is actually running on the same machine as | |
10877 | your debugger session (e.g.@: a simulator of your target running on | |
10878 | the same host), you can omit the hostname. For example, to connect | |
10879 | to port 1234 on your local machine: | |
10880 | ||
474c8240 | 10881 | @smallexample |
a2bea4c3 | 10882 | target remote :1234 |
474c8240 | 10883 | @end smallexample |
a2bea4c3 CV |
10884 | @noindent |
10885 | ||
10886 | Note that the colon is still required here. | |
9db8d71f DJ |
10887 | |
10888 | @cindex UDP port, @code{target remote} | |
10889 | To use a UDP connection, use an argument of the form | |
10890 | @code{udp:@var{host}:@var{port}}. For example, to connect to UDP port 2828 | |
10891 | on a terminal server named @code{manyfarms}: | |
10892 | ||
10893 | @smallexample | |
10894 | target remote udp:manyfarms:2828 | |
10895 | @end smallexample | |
10896 | ||
10897 | When using a UDP connection for remote debugging, you should keep in mind | |
10898 | that the `U' stands for ``Unreliable''. UDP can silently drop packets on | |
10899 | busy or unreliable networks, which will cause havoc with your debugging | |
10900 | session. | |
10901 | ||
104c1213 JM |
10902 | @end enumerate |
10903 | ||
10904 | Now you can use all the usual commands to examine and change data and to | |
10905 | step and continue the remote program. | |
10906 | ||
10907 | To resume the remote program and stop debugging it, use the @code{detach} | |
10908 | command. | |
10909 | ||
10910 | @cindex interrupting remote programs | |
10911 | @cindex remote programs, interrupting | |
10912 | Whenever @value{GDBN} is waiting for the remote program, if you type the | |
10913 | interrupt character (often @key{C-C}), @value{GDBN} attempts to stop the | |
10914 | program. This may or may not succeed, depending in part on the hardware | |
10915 | and the serial drivers the remote system uses. If you type the | |
10916 | interrupt character once again, @value{GDBN} displays this prompt: | |
10917 | ||
474c8240 | 10918 | @smallexample |
104c1213 JM |
10919 | Interrupted while waiting for the program. |
10920 | Give up (and stop debugging it)? (y or n) | |
474c8240 | 10921 | @end smallexample |
104c1213 JM |
10922 | |
10923 | If you type @kbd{y}, @value{GDBN} abandons the remote debugging session. | |
10924 | (If you decide you want to try again later, you can use @samp{target | |
10925 | remote} again to connect once more.) If you type @kbd{n}, @value{GDBN} | |
10926 | goes back to waiting. | |
10927 | ||
104c1213 | 10928 | |
8e04817f AC |
10929 | @node Configurations |
10930 | @chapter Configuration-Specific Information | |
104c1213 | 10931 | |
8e04817f AC |
10932 | While nearly all @value{GDBN} commands are available for all native and |
10933 | cross versions of the debugger, there are some exceptions. This chapter | |
10934 | describes things that are only available in certain configurations. | |
104c1213 | 10935 | |
8e04817f AC |
10936 | There are three major categories of configurations: native |
10937 | configurations, where the host and target are the same, embedded | |
10938 | operating system configurations, which are usually the same for several | |
10939 | different processor architectures, and bare embedded processors, which | |
10940 | are quite different from each other. | |
104c1213 | 10941 | |
8e04817f AC |
10942 | @menu |
10943 | * Native:: | |
10944 | * Embedded OS:: | |
10945 | * Embedded Processors:: | |
10946 | * Architectures:: | |
10947 | @end menu | |
104c1213 | 10948 | |
8e04817f AC |
10949 | @node Native |
10950 | @section Native | |
104c1213 | 10951 | |
8e04817f AC |
10952 | This section describes details specific to particular native |
10953 | configurations. | |
6cf7e474 | 10954 | |
8e04817f AC |
10955 | @menu |
10956 | * HP-UX:: HP-UX | |
10957 | * SVR4 Process Information:: SVR4 process information | |
10958 | * DJGPP Native:: Features specific to the DJGPP port | |
78c47bea | 10959 | * Cygwin Native:: Features specific to the Cygwin port |
8e04817f | 10960 | @end menu |
6cf7e474 | 10961 | |
8e04817f AC |
10962 | @node HP-UX |
10963 | @subsection HP-UX | |
104c1213 | 10964 | |
8e04817f AC |
10965 | On HP-UX systems, if you refer to a function or variable name that |
10966 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
10967 | name first, before it searches for a convenience variable. | |
104c1213 | 10968 | |
8e04817f AC |
10969 | @node SVR4 Process Information |
10970 | @subsection SVR4 process information | |
104c1213 | 10971 | |
8e04817f AC |
10972 | @kindex /proc |
10973 | @cindex process image | |
104c1213 | 10974 | |
8e04817f AC |
10975 | Many versions of SVR4 provide a facility called @samp{/proc} that can be |
10976 | used to examine the image of a running process using file-system | |
10977 | subroutines. If @value{GDBN} is configured for an operating system with | |
10978 | this facility, the command @code{info proc} is available to report on | |
10979 | several kinds of information about the process running your program. | |
10980 | @code{info proc} works only on SVR4 systems that include the | |
10981 | @code{procfs} code. This includes OSF/1 (Digital Unix), Solaris, Irix, | |
1104b9e7 | 10982 | and Unixware, but not HP-UX or @sc{gnu}/Linux, for example. |
104c1213 | 10983 | |
8e04817f AC |
10984 | @table @code |
10985 | @kindex info proc | |
10986 | @item info proc | |
10987 | Summarize available information about the process. | |
6cf7e474 | 10988 | |
8e04817f AC |
10989 | @kindex info proc mappings |
10990 | @item info proc mappings | |
10991 | Report on the address ranges accessible in the program, with information | |
10992 | on whether your program may read, write, or execute each range. | |
10993 | @ignore | |
10994 | @comment These sub-options of 'info proc' were not included when | |
10995 | @comment procfs.c was re-written. Keep their descriptions around | |
10996 | @comment against the day when someone finds the time to put them back in. | |
10997 | @kindex info proc times | |
10998 | @item info proc times | |
10999 | Starting time, user CPU time, and system CPU time for your program and | |
11000 | its children. | |
6cf7e474 | 11001 | |
8e04817f AC |
11002 | @kindex info proc id |
11003 | @item info proc id | |
11004 | Report on the process IDs related to your program: its own process ID, | |
11005 | the ID of its parent, the process group ID, and the session ID. | |
104c1213 | 11006 | |
8e04817f AC |
11007 | @kindex info proc status |
11008 | @item info proc status | |
11009 | General information on the state of the process. If the process is | |
11010 | stopped, this report includes the reason for stopping, and any signal | |
11011 | received. | |
d4f3574e | 11012 | |
8e04817f AC |
11013 | @item info proc all |
11014 | Show all the above information about the process. | |
11015 | @end ignore | |
11016 | @end table | |
104c1213 | 11017 | |
8e04817f AC |
11018 | @node DJGPP Native |
11019 | @subsection Features for Debugging @sc{djgpp} Programs | |
11020 | @cindex @sc{djgpp} debugging | |
11021 | @cindex native @sc{djgpp} debugging | |
11022 | @cindex MS-DOS-specific commands | |
104c1213 | 11023 | |
8e04817f AC |
11024 | @sc{djgpp} is the port of @sc{gnu} development tools to MS-DOS and |
11025 | MS-Windows. @sc{djgpp} programs are 32-bit protected-mode programs | |
11026 | that use the @dfn{DPMI} (DOS Protected-Mode Interface) API to run on | |
11027 | top of real-mode DOS systems and their emulations. | |
104c1213 | 11028 | |
8e04817f AC |
11029 | @value{GDBN} supports native debugging of @sc{djgpp} programs, and |
11030 | defines a few commands specific to the @sc{djgpp} port. This | |
11031 | subsection describes those commands. | |
104c1213 | 11032 | |
8e04817f AC |
11033 | @table @code |
11034 | @kindex info dos | |
11035 | @item info dos | |
11036 | This is a prefix of @sc{djgpp}-specific commands which print | |
11037 | information about the target system and important OS structures. | |
f1251bdd | 11038 | |
8e04817f AC |
11039 | @kindex sysinfo |
11040 | @cindex MS-DOS system info | |
11041 | @cindex free memory information (MS-DOS) | |
11042 | @item info dos sysinfo | |
11043 | This command displays assorted information about the underlying | |
11044 | platform: the CPU type and features, the OS version and flavor, the | |
11045 | DPMI version, and the available conventional and DPMI memory. | |
104c1213 | 11046 | |
8e04817f AC |
11047 | @cindex GDT |
11048 | @cindex LDT | |
11049 | @cindex IDT | |
11050 | @cindex segment descriptor tables | |
11051 | @cindex descriptor tables display | |
11052 | @item info dos gdt | |
11053 | @itemx info dos ldt | |
11054 | @itemx info dos idt | |
11055 | These 3 commands display entries from, respectively, Global, Local, | |
11056 | and Interrupt Descriptor Tables (GDT, LDT, and IDT). The descriptor | |
11057 | tables are data structures which store a descriptor for each segment | |
11058 | that is currently in use. The segment's selector is an index into a | |
11059 | descriptor table; the table entry for that index holds the | |
11060 | descriptor's base address and limit, and its attributes and access | |
11061 | rights. | |
104c1213 | 11062 | |
8e04817f AC |
11063 | A typical @sc{djgpp} program uses 3 segments: a code segment, a data |
11064 | segment (used for both data and the stack), and a DOS segment (which | |
11065 | allows access to DOS/BIOS data structures and absolute addresses in | |
11066 | conventional memory). However, the DPMI host will usually define | |
11067 | additional segments in order to support the DPMI environment. | |
d4f3574e | 11068 | |
8e04817f AC |
11069 | @cindex garbled pointers |
11070 | These commands allow to display entries from the descriptor tables. | |
11071 | Without an argument, all entries from the specified table are | |
11072 | displayed. An argument, which should be an integer expression, means | |
11073 | display a single entry whose index is given by the argument. For | |
11074 | example, here's a convenient way to display information about the | |
11075 | debugged program's data segment: | |
104c1213 | 11076 | |
8e04817f AC |
11077 | @smallexample |
11078 | @exdent @code{(@value{GDBP}) info dos ldt $ds} | |
11079 | @exdent @code{0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up)} | |
11080 | @end smallexample | |
104c1213 | 11081 | |
8e04817f AC |
11082 | @noindent |
11083 | This comes in handy when you want to see whether a pointer is outside | |
11084 | the data segment's limit (i.e.@: @dfn{garbled}). | |
104c1213 | 11085 | |
8e04817f AC |
11086 | @cindex page tables display (MS-DOS) |
11087 | @item info dos pde | |
11088 | @itemx info dos pte | |
11089 | These two commands display entries from, respectively, the Page | |
11090 | Directory and the Page Tables. Page Directories and Page Tables are | |
11091 | data structures which control how virtual memory addresses are mapped | |
11092 | into physical addresses. A Page Table includes an entry for every | |
11093 | page of memory that is mapped into the program's address space; there | |
11094 | may be several Page Tables, each one holding up to 4096 entries. A | |
11095 | Page Directory has up to 4096 entries, one each for every Page Table | |
11096 | that is currently in use. | |
104c1213 | 11097 | |
8e04817f AC |
11098 | Without an argument, @kbd{info dos pde} displays the entire Page |
11099 | Directory, and @kbd{info dos pte} displays all the entries in all of | |
11100 | the Page Tables. An argument, an integer expression, given to the | |
11101 | @kbd{info dos pde} command means display only that entry from the Page | |
11102 | Directory table. An argument given to the @kbd{info dos pte} command | |
11103 | means display entries from a single Page Table, the one pointed to by | |
11104 | the specified entry in the Page Directory. | |
104c1213 | 11105 | |
8e04817f AC |
11106 | @cindex direct memory access (DMA) on MS-DOS |
11107 | These commands are useful when your program uses @dfn{DMA} (Direct | |
11108 | Memory Access), which needs physical addresses to program the DMA | |
11109 | controller. | |
104c1213 | 11110 | |
8e04817f | 11111 | These commands are supported only with some DPMI servers. |
104c1213 | 11112 | |
8e04817f AC |
11113 | @cindex physical address from linear address |
11114 | @item info dos address-pte @var{addr} | |
11115 | This command displays the Page Table entry for a specified linear | |
11116 | address. The argument linear address @var{addr} should already have the | |
11117 | appropriate segment's base address added to it, because this command | |
11118 | accepts addresses which may belong to @emph{any} segment. For | |
11119 | example, here's how to display the Page Table entry for the page where | |
11120 | the variable @code{i} is stored: | |
104c1213 | 11121 | |
8e04817f AC |
11122 | @smallexample |
11123 | @exdent @code{(@value{GDBP}) info dos address-pte __djgpp_base_address + (char *)&i} | |
11124 | @exdent @code{Page Table entry for address 0x11a00d30:} | |
11125 | @exdent @code{Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30} | |
11126 | @end smallexample | |
104c1213 | 11127 | |
8e04817f AC |
11128 | @noindent |
11129 | This says that @code{i} is stored at offset @code{0xd30} from the page | |
11130 | whose physical base address is @code{0x02698000}, and prints all the | |
11131 | attributes of that page. | |
104c1213 | 11132 | |
8e04817f AC |
11133 | Note that you must cast the addresses of variables to a @code{char *}, |
11134 | since otherwise the value of @code{__djgpp_base_address}, the base | |
11135 | address of all variables and functions in a @sc{djgpp} program, will | |
11136 | be added using the rules of C pointer arithmetics: if @code{i} is | |
11137 | declared an @code{int}, @value{GDBN} will add 4 times the value of | |
11138 | @code{__djgpp_base_address} to the address of @code{i}. | |
104c1213 | 11139 | |
8e04817f AC |
11140 | Here's another example, it displays the Page Table entry for the |
11141 | transfer buffer: | |
104c1213 | 11142 | |
8e04817f AC |
11143 | @smallexample |
11144 | @exdent @code{(@value{GDBP}) info dos address-pte *((unsigned *)&_go32_info_block + 3)} | |
11145 | @exdent @code{Page Table entry for address 0x29110:} | |
11146 | @exdent @code{Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110} | |
11147 | @end smallexample | |
104c1213 | 11148 | |
8e04817f AC |
11149 | @noindent |
11150 | (The @code{+ 3} offset is because the transfer buffer's address is the | |
11151 | 3rd member of the @code{_go32_info_block} structure.) The output of | |
11152 | this command clearly shows that addresses in conventional memory are | |
11153 | mapped 1:1, i.e.@: the physical and linear addresses are identical. | |
104c1213 | 11154 | |
8e04817f AC |
11155 | This command is supported only with some DPMI servers. |
11156 | @end table | |
104c1213 | 11157 | |
78c47bea PM |
11158 | @node Cygwin Native |
11159 | @subsection Features for Debugging MS Windows PE executables | |
11160 | @cindex MS Windows debugging | |
11161 | @cindex native Cygwin debugging | |
11162 | @cindex Cygwin-specific commands | |
11163 | ||
be448670 CF |
11164 | @value{GDBN} supports native debugging of MS Windows programs, including |
11165 | DLLs with and without symbolic debugging information. There are various | |
11166 | additional Cygwin-specific commands, described in this subsection. The | |
11167 | subsubsection @pxref{Non-debug DLL symbols} describes working with DLLs | |
11168 | that have no debugging symbols. | |
11169 | ||
78c47bea PM |
11170 | |
11171 | @table @code | |
11172 | @kindex info w32 | |
11173 | @item info w32 | |
11174 | This is a prefix of MS Windows specific commands which print | |
11175 | information about the target system and important OS structures. | |
11176 | ||
11177 | @item info w32 selector | |
11178 | This command displays information returned by | |
11179 | the Win32 API @code{GetThreadSelectorEntry} function. | |
11180 | It takes an optional argument that is evaluated to | |
11181 | a long value to give the information about this given selector. | |
11182 | Without argument, this command displays information | |
11183 | about the the six segment registers. | |
11184 | ||
11185 | @kindex info dll | |
11186 | @item info dll | |
11187 | This is a Cygwin specific alias of info shared. | |
11188 | ||
11189 | @kindex dll-symbols | |
11190 | @item dll-symbols | |
11191 | This command loads symbols from a dll similarly to | |
11192 | add-sym command but without the need to specify a base address. | |
11193 | ||
11194 | @kindex set new-console | |
11195 | @item set new-console @var{mode} | |
11196 | If @var{mode} is @code{on} the debuggee will | |
11197 | be started in a new console on next start. | |
11198 | If @var{mode} is @code{off}i, the debuggee will | |
11199 | be started in the same console as the debugger. | |
11200 | ||
11201 | @kindex show new-console | |
11202 | @item show new-console | |
11203 | Displays whether a new console is used | |
11204 | when the debuggee is started. | |
11205 | ||
11206 | @kindex set new-group | |
11207 | @item set new-group @var{mode} | |
11208 | This boolean value controls whether the debuggee should | |
11209 | start a new group or stay in the same group as the debugger. | |
11210 | This affects the way the Windows OS handles | |
11211 | Ctrl-C. | |
11212 | ||
11213 | @kindex show new-group | |
11214 | @item show new-group | |
11215 | Displays current value of new-group boolean. | |
11216 | ||
11217 | @kindex set debugevents | |
11218 | @item set debugevents | |
11219 | This boolean value adds debug output concerning events seen by the debugger. | |
11220 | ||
11221 | @kindex set debugexec | |
11222 | @item set debugexec | |
11223 | This boolean value adds debug output concerning execute events | |
11224 | seen by the debugger. | |
11225 | ||
11226 | @kindex set debugexceptions | |
11227 | @item set debugexceptions | |
11228 | This boolean value adds debug ouptut concerning exception events | |
11229 | seen by the debugger. | |
11230 | ||
11231 | @kindex set debugmemory | |
11232 | @item set debugmemory | |
11233 | This boolean value adds debug ouptut concerning memory events | |
11234 | seen by the debugger. | |
11235 | ||
11236 | @kindex set shell | |
11237 | @item set shell | |
11238 | This boolean values specifies whether the debuggee is called | |
11239 | via a shell or directly (default value is on). | |
11240 | ||
11241 | @kindex show shell | |
11242 | @item show shell | |
11243 | Displays if the debuggee will be started with a shell. | |
11244 | ||
11245 | @end table | |
11246 | ||
be448670 CF |
11247 | @menu |
11248 | * Non-debug DLL symbols:: Support for DLLs without debugging symbols | |
11249 | @end menu | |
11250 | ||
11251 | @node Non-debug DLL symbols | |
11252 | @subsubsection Support for DLLs without debugging symbols | |
11253 | @cindex DLLs with no debugging symbols | |
11254 | @cindex Minimal symbols and DLLs | |
11255 | ||
11256 | Very often on windows, some of the DLLs that your program relies on do | |
11257 | not include symbolic debugging information (for example, | |
11258 | @file{kernel32.dll}). When @value{GDBN} doesn't recognize any debugging | |
11259 | symbols in a DLL, it relies on the minimal amount of symbolic | |
11260 | information contained in the DLL's export table. This subsubsection | |
11261 | describes working with such symbols, known internally to @value{GDBN} as | |
11262 | ``minimal symbols''. | |
11263 | ||
11264 | Note that before the debugged program has started execution, no DLLs | |
11265 | will have been loaded. The easiest way around this problem is simply to | |
11266 | start the program --- either by setting a breakpoint or letting the | |
11267 | program run once to completion. It is also possible to force | |
11268 | @value{GDBN} to load a particular DLL before starting the executable --- | |
11269 | see the shared library information in @pxref{Files} or the | |
11270 | @code{dll-symbols} command in @pxref{Cygwin Native}. Currently, | |
11271 | explicitly loading symbols from a DLL with no debugging information will | |
11272 | cause the symbol names to be duplicated in @value{GDBN}'s lookup table, | |
11273 | which may adversely affect symbol lookup performance. | |
11274 | ||
11275 | @subsubsection DLL name prefixes | |
11276 | ||
11277 | In keeping with the naming conventions used by the Microsoft debugging | |
11278 | tools, DLL export symbols are made available with a prefix based on the | |
11279 | DLL name, for instance @code{KERNEL32!CreateFileA}. The plain name is | |
11280 | also entered into the symbol table, so @code{CreateFileA} is often | |
11281 | sufficient. In some cases there will be name clashes within a program | |
11282 | (particularly if the executable itself includes full debugging symbols) | |
11283 | necessitating the use of the fully qualified name when referring to the | |
11284 | contents of the DLL. Use single-quotes around the name to avoid the | |
11285 | exclamation mark (``!'') being interpreted as a language operator. | |
11286 | ||
11287 | Note that the internal name of the DLL may be all upper-case, even | |
11288 | though the file name of the DLL is lower-case, or vice-versa. Since | |
11289 | symbols within @value{GDBN} are @emph{case-sensitive} this may cause | |
11290 | some confusion. If in doubt, try the @code{info functions} and | |
11291 | @code{info variables} commands or even @code{maint print msymbols} (see | |
11292 | @pxref{Symbols}). Here's an example: | |
11293 | ||
11294 | @smallexample | |
11295 | (gdb) info function CreateFileA | |
11296 | All functions matching regular expression "CreateFileA": | |
11297 | ||
11298 | Non-debugging symbols: | |
11299 | 0x77e885f4 CreateFileA | |
11300 | 0x77e885f4 KERNEL32!CreateFileA | |
11301 | @end smallexample | |
11302 | ||
11303 | @smallexample | |
11304 | (gdb) info function ! | |
11305 | All functions matching regular expression "!": | |
11306 | ||
11307 | Non-debugging symbols: | |
11308 | 0x6100114c cygwin1!__assert | |
11309 | 0x61004034 cygwin1!_dll_crt0@@0 | |
11310 | 0x61004240 cygwin1!dll_crt0(per_process *) | |
11311 | [etc...] | |
11312 | @end smallexample | |
11313 | ||
11314 | @subsubsection Working with minimal symbols | |
11315 | ||
11316 | Symbols extracted from a DLL's export table do not contain very much | |
11317 | type information. All that @value{GDBN} can do is guess whether a symbol | |
11318 | refers to a function or variable depending on the linker section that | |
11319 | contains the symbol. Also note that the actual contents of the memory | |
11320 | contained in a DLL are not available unless the program is running. This | |
11321 | means that you cannot examine the contents of a variable or disassemble | |
11322 | a function within a DLL without a running program. | |
11323 | ||
11324 | Variables are generally treated as pointers and dereferenced | |
11325 | automatically. For this reason, it is often necessary to prefix a | |
11326 | variable name with the address-of operator (``&'') and provide explicit | |
11327 | type information in the command. Here's an example of the type of | |
11328 | problem: | |
11329 | ||
11330 | @smallexample | |
11331 | (gdb) print 'cygwin1!__argv' | |
11332 | $1 = 268572168 | |
11333 | @end smallexample | |
11334 | ||
11335 | @smallexample | |
11336 | (gdb) x 'cygwin1!__argv' | |
11337 | 0x10021610: "\230y\"" | |
11338 | @end smallexample | |
11339 | ||
11340 | And two possible solutions: | |
11341 | ||
11342 | @smallexample | |
11343 | (gdb) print ((char **)'cygwin1!__argv')[0] | |
11344 | $2 = 0x22fd98 "/cygdrive/c/mydirectory/myprogram" | |
11345 | @end smallexample | |
11346 | ||
11347 | @smallexample | |
11348 | (gdb) x/2x &'cygwin1!__argv' | |
11349 | 0x610c0aa8 <cygwin1!__argv>: 0x10021608 0x00000000 | |
11350 | (gdb) x/x 0x10021608 | |
11351 | 0x10021608: 0x0022fd98 | |
11352 | (gdb) x/s 0x0022fd98 | |
11353 | 0x22fd98: "/cygdrive/c/mydirectory/myprogram" | |
11354 | @end smallexample | |
11355 | ||
11356 | Setting a break point within a DLL is possible even before the program | |
11357 | starts execution. However, under these circumstances, @value{GDBN} can't | |
11358 | examine the initial instructions of the function in order to skip the | |
11359 | function's frame set-up code. You can work around this by using ``*&'' | |
11360 | to set the breakpoint at a raw memory address: | |
11361 | ||
11362 | @smallexample | |
11363 | (gdb) break *&'python22!PyOS_Readline' | |
11364 | Breakpoint 1 at 0x1e04eff0 | |
11365 | @end smallexample | |
11366 | ||
11367 | The author of these extensions is not entirely convinced that setting a | |
11368 | break point within a shared DLL like @file{kernel32.dll} is completely | |
11369 | safe. | |
11370 | ||
8e04817f AC |
11371 | @node Embedded OS |
11372 | @section Embedded Operating Systems | |
104c1213 | 11373 | |
8e04817f AC |
11374 | This section describes configurations involving the debugging of |
11375 | embedded operating systems that are available for several different | |
11376 | architectures. | |
d4f3574e | 11377 | |
8e04817f AC |
11378 | @menu |
11379 | * VxWorks:: Using @value{GDBN} with VxWorks | |
11380 | @end menu | |
104c1213 | 11381 | |
8e04817f AC |
11382 | @value{GDBN} includes the ability to debug programs running on |
11383 | various real-time operating systems. | |
104c1213 | 11384 | |
8e04817f AC |
11385 | @node VxWorks |
11386 | @subsection Using @value{GDBN} with VxWorks | |
104c1213 | 11387 | |
8e04817f | 11388 | @cindex VxWorks |
104c1213 | 11389 | |
8e04817f | 11390 | @table @code |
104c1213 | 11391 | |
8e04817f AC |
11392 | @kindex target vxworks |
11393 | @item target vxworks @var{machinename} | |
11394 | A VxWorks system, attached via TCP/IP. The argument @var{machinename} | |
11395 | is the target system's machine name or IP address. | |
104c1213 | 11396 | |
8e04817f | 11397 | @end table |
104c1213 | 11398 | |
8e04817f AC |
11399 | On VxWorks, @code{load} links @var{filename} dynamically on the |
11400 | current target system as well as adding its symbols in @value{GDBN}. | |
104c1213 | 11401 | |
8e04817f AC |
11402 | @value{GDBN} enables developers to spawn and debug tasks running on networked |
11403 | VxWorks targets from a Unix host. Already-running tasks spawned from | |
11404 | the VxWorks shell can also be debugged. @value{GDBN} uses code that runs on | |
11405 | both the Unix host and on the VxWorks target. The program | |
11406 | @code{@value{GDBP}} is installed and executed on the Unix host. (It may be | |
11407 | installed with the name @code{vxgdb}, to distinguish it from a | |
11408 | @value{GDBN} for debugging programs on the host itself.) | |
104c1213 | 11409 | |
8e04817f AC |
11410 | @table @code |
11411 | @item VxWorks-timeout @var{args} | |
11412 | @kindex vxworks-timeout | |
11413 | All VxWorks-based targets now support the option @code{vxworks-timeout}. | |
11414 | This option is set by the user, and @var{args} represents the number of | |
11415 | seconds @value{GDBN} waits for responses to rpc's. You might use this if | |
11416 | your VxWorks target is a slow software simulator or is on the far side | |
11417 | of a thin network line. | |
11418 | @end table | |
104c1213 | 11419 | |
8e04817f AC |
11420 | The following information on connecting to VxWorks was current when |
11421 | this manual was produced; newer releases of VxWorks may use revised | |
11422 | procedures. | |
104c1213 | 11423 | |
8e04817f AC |
11424 | @kindex INCLUDE_RDB |
11425 | To use @value{GDBN} with VxWorks, you must rebuild your VxWorks kernel | |
11426 | to include the remote debugging interface routines in the VxWorks | |
11427 | library @file{rdb.a}. To do this, define @code{INCLUDE_RDB} in the | |
11428 | VxWorks configuration file @file{configAll.h} and rebuild your VxWorks | |
11429 | kernel. The resulting kernel contains @file{rdb.a}, and spawns the | |
11430 | source debugging task @code{tRdbTask} when VxWorks is booted. For more | |
11431 | information on configuring and remaking VxWorks, see the manufacturer's | |
11432 | manual. | |
11433 | @c VxWorks, see the @cite{VxWorks Programmer's Guide}. | |
104c1213 | 11434 | |
8e04817f AC |
11435 | Once you have included @file{rdb.a} in your VxWorks system image and set |
11436 | your Unix execution search path to find @value{GDBN}, you are ready to | |
11437 | run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} (or | |
11438 | @code{vxgdb}, depending on your installation). | |
104c1213 | 11439 | |
8e04817f | 11440 | @value{GDBN} comes up showing the prompt: |
104c1213 | 11441 | |
474c8240 | 11442 | @smallexample |
8e04817f | 11443 | (vxgdb) |
474c8240 | 11444 | @end smallexample |
104c1213 | 11445 | |
8e04817f AC |
11446 | @menu |
11447 | * VxWorks Connection:: Connecting to VxWorks | |
11448 | * VxWorks Download:: VxWorks download | |
11449 | * VxWorks Attach:: Running tasks | |
11450 | @end menu | |
104c1213 | 11451 | |
8e04817f AC |
11452 | @node VxWorks Connection |
11453 | @subsubsection Connecting to VxWorks | |
104c1213 | 11454 | |
8e04817f AC |
11455 | The @value{GDBN} command @code{target} lets you connect to a VxWorks target on the |
11456 | network. To connect to a target whose host name is ``@code{tt}'', type: | |
104c1213 | 11457 | |
474c8240 | 11458 | @smallexample |
8e04817f | 11459 | (vxgdb) target vxworks tt |
474c8240 | 11460 | @end smallexample |
104c1213 | 11461 | |
8e04817f AC |
11462 | @need 750 |
11463 | @value{GDBN} displays messages like these: | |
104c1213 | 11464 | |
8e04817f AC |
11465 | @smallexample |
11466 | Attaching remote machine across net... | |
11467 | Connected to tt. | |
11468 | @end smallexample | |
104c1213 | 11469 | |
8e04817f AC |
11470 | @need 1000 |
11471 | @value{GDBN} then attempts to read the symbol tables of any object modules | |
11472 | loaded into the VxWorks target since it was last booted. @value{GDBN} locates | |
11473 | these files by searching the directories listed in the command search | |
11474 | path (@pxref{Environment, ,Your program's environment}); if it fails | |
11475 | to find an object file, it displays a message such as: | |
5d161b24 | 11476 | |
474c8240 | 11477 | @smallexample |
8e04817f | 11478 | prog.o: No such file or directory. |
474c8240 | 11479 | @end smallexample |
104c1213 | 11480 | |
8e04817f AC |
11481 | When this happens, add the appropriate directory to the search path with |
11482 | the @value{GDBN} command @code{path}, and execute the @code{target} | |
11483 | command again. | |
104c1213 | 11484 | |
8e04817f AC |
11485 | @node VxWorks Download |
11486 | @subsubsection VxWorks download | |
104c1213 | 11487 | |
8e04817f AC |
11488 | @cindex download to VxWorks |
11489 | If you have connected to the VxWorks target and you want to debug an | |
11490 | object that has not yet been loaded, you can use the @value{GDBN} | |
11491 | @code{load} command to download a file from Unix to VxWorks | |
11492 | incrementally. The object file given as an argument to the @code{load} | |
11493 | command is actually opened twice: first by the VxWorks target in order | |
11494 | to download the code, then by @value{GDBN} in order to read the symbol | |
11495 | table. This can lead to problems if the current working directories on | |
11496 | the two systems differ. If both systems have NFS mounted the same | |
11497 | filesystems, you can avoid these problems by using absolute paths. | |
11498 | Otherwise, it is simplest to set the working directory on both systems | |
11499 | to the directory in which the object file resides, and then to reference | |
11500 | the file by its name, without any path. For instance, a program | |
11501 | @file{prog.o} may reside in @file{@var{vxpath}/vw/demo/rdb} in VxWorks | |
11502 | and in @file{@var{hostpath}/vw/demo/rdb} on the host. To load this | |
11503 | program, type this on VxWorks: | |
104c1213 | 11504 | |
474c8240 | 11505 | @smallexample |
8e04817f | 11506 | -> cd "@var{vxpath}/vw/demo/rdb" |
474c8240 | 11507 | @end smallexample |
104c1213 | 11508 | |
8e04817f AC |
11509 | @noindent |
11510 | Then, in @value{GDBN}, type: | |
104c1213 | 11511 | |
474c8240 | 11512 | @smallexample |
8e04817f AC |
11513 | (vxgdb) cd @var{hostpath}/vw/demo/rdb |
11514 | (vxgdb) load prog.o | |
474c8240 | 11515 | @end smallexample |
104c1213 | 11516 | |
8e04817f | 11517 | @value{GDBN} displays a response similar to this: |
104c1213 | 11518 | |
8e04817f AC |
11519 | @smallexample |
11520 | Reading symbol data from wherever/vw/demo/rdb/prog.o... done. | |
11521 | @end smallexample | |
104c1213 | 11522 | |
8e04817f AC |
11523 | You can also use the @code{load} command to reload an object module |
11524 | after editing and recompiling the corresponding source file. Note that | |
11525 | this makes @value{GDBN} delete all currently-defined breakpoints, | |
11526 | auto-displays, and convenience variables, and to clear the value | |
11527 | history. (This is necessary in order to preserve the integrity of | |
11528 | debugger's data structures that reference the target system's symbol | |
11529 | table.) | |
104c1213 | 11530 | |
8e04817f AC |
11531 | @node VxWorks Attach |
11532 | @subsubsection Running tasks | |
104c1213 JM |
11533 | |
11534 | @cindex running VxWorks tasks | |
11535 | You can also attach to an existing task using the @code{attach} command as | |
11536 | follows: | |
11537 | ||
474c8240 | 11538 | @smallexample |
104c1213 | 11539 | (vxgdb) attach @var{task} |
474c8240 | 11540 | @end smallexample |
104c1213 JM |
11541 | |
11542 | @noindent | |
11543 | where @var{task} is the VxWorks hexadecimal task ID. The task can be running | |
11544 | or suspended when you attach to it. Running tasks are suspended at | |
11545 | the time of attachment. | |
11546 | ||
6d2ebf8b | 11547 | @node Embedded Processors |
104c1213 JM |
11548 | @section Embedded Processors |
11549 | ||
11550 | This section goes into details specific to particular embedded | |
11551 | configurations. | |
11552 | ||
7d86b5d5 | 11553 | |
104c1213 | 11554 | @menu |
104c1213 JM |
11555 | * ARM:: ARM |
11556 | * H8/300:: Hitachi H8/300 | |
11557 | * H8/500:: Hitachi H8/500 | |
104c1213 JM |
11558 | * M32R/D:: Mitsubishi M32R/D |
11559 | * M68K:: Motorola M68K | |
104c1213 | 11560 | * MIPS Embedded:: MIPS Embedded |
a37295f9 | 11561 | * OpenRISC 1000:: OpenRisc 1000 |
104c1213 JM |
11562 | * PA:: HP PA Embedded |
11563 | * PowerPC: PowerPC | |
11564 | * SH:: Hitachi SH | |
11565 | * Sparclet:: Tsqware Sparclet | |
11566 | * Sparclite:: Fujitsu Sparclite | |
11567 | * ST2000:: Tandem ST2000 | |
11568 | * Z8000:: Zilog Z8000 | |
11569 | @end menu | |
11570 | ||
6d2ebf8b | 11571 | @node ARM |
104c1213 JM |
11572 | @subsection ARM |
11573 | ||
11574 | @table @code | |
11575 | ||
8e04817f AC |
11576 | @kindex target rdi |
11577 | @item target rdi @var{dev} | |
11578 | ARM Angel monitor, via RDI library interface to ADP protocol. You may | |
11579 | use this target to communicate with both boards running the Angel | |
11580 | monitor, or with the EmbeddedICE JTAG debug device. | |
11581 | ||
11582 | @kindex target rdp | |
11583 | @item target rdp @var{dev} | |
11584 | ARM Demon monitor. | |
11585 | ||
11586 | @end table | |
11587 | ||
11588 | @node H8/300 | |
11589 | @subsection Hitachi H8/300 | |
11590 | ||
11591 | @table @code | |
11592 | ||
11593 | @kindex target hms@r{, with H8/300} | |
11594 | @item target hms @var{dev} | |
11595 | A Hitachi SH, H8/300, or H8/500 board, attached via serial line to your host. | |
11596 | Use special commands @code{device} and @code{speed} to control the serial | |
11597 | line and the communications speed used. | |
11598 | ||
11599 | @kindex target e7000@r{, with H8/300} | |
11600 | @item target e7000 @var{dev} | |
11601 | E7000 emulator for Hitachi H8 and SH. | |
11602 | ||
11603 | @kindex target sh3@r{, with H8/300} | |
11604 | @kindex target sh3e@r{, with H8/300} | |
11605 | @item target sh3 @var{dev} | |
11606 | @itemx target sh3e @var{dev} | |
11607 | Hitachi SH-3 and SH-3E target systems. | |
11608 | ||
11609 | @end table | |
11610 | ||
11611 | @cindex download to H8/300 or H8/500 | |
11612 | @cindex H8/300 or H8/500 download | |
11613 | @cindex download to Hitachi SH | |
11614 | @cindex Hitachi SH download | |
11615 | When you select remote debugging to a Hitachi SH, H8/300, or H8/500 | |
11616 | board, the @code{load} command downloads your program to the Hitachi | |
11617 | board and also opens it as the current executable target for | |
11618 | @value{GDBN} on your host (like the @code{file} command). | |
11619 | ||
11620 | @value{GDBN} needs to know these things to talk to your | |
11621 | Hitachi SH, H8/300, or H8/500: | |
11622 | ||
11623 | @enumerate | |
11624 | @item | |
11625 | that you want to use @samp{target hms}, the remote debugging interface | |
11626 | for Hitachi microprocessors, or @samp{target e7000}, the in-circuit | |
11627 | emulator for the Hitachi SH and the Hitachi 300H. (@samp{target hms} is | |
11628 | the default when @value{GDBN} is configured specifically for the Hitachi SH, | |
11629 | H8/300, or H8/500.) | |
11630 | ||
11631 | @item | |
11632 | what serial device connects your host to your Hitachi board (the first | |
11633 | serial device available on your host is the default). | |
11634 | ||
11635 | @item | |
11636 | what speed to use over the serial device. | |
11637 | @end enumerate | |
11638 | ||
11639 | @menu | |
11640 | * Hitachi Boards:: Connecting to Hitachi boards. | |
11641 | * Hitachi ICE:: Using the E7000 In-Circuit Emulator. | |
11642 | * Hitachi Special:: Special @value{GDBN} commands for Hitachi micros. | |
11643 | @end menu | |
11644 | ||
11645 | @node Hitachi Boards | |
11646 | @subsubsection Connecting to Hitachi boards | |
11647 | ||
11648 | @c only for Unix hosts | |
11649 | @kindex device | |
11650 | @cindex serial device, Hitachi micros | |
11651 | Use the special @code{@value{GDBN}} command @samp{device @var{port}} if you | |
11652 | need to explicitly set the serial device. The default @var{port} is the | |
11653 | first available port on your host. This is only necessary on Unix | |
11654 | hosts, where it is typically something like @file{/dev/ttya}. | |
11655 | ||
11656 | @kindex speed | |
11657 | @cindex serial line speed, Hitachi micros | |
11658 | @code{@value{GDBN}} has another special command to set the communications | |
11659 | speed: @samp{speed @var{bps}}. This command also is only used from Unix | |
11660 | hosts; on DOS hosts, set the line speed as usual from outside @value{GDBN} with | |
11661 | the DOS @code{mode} command (for instance, | |
11662 | @w{@kbd{mode com2:9600,n,8,1,p}} for a 9600@dmn{bps} connection). | |
11663 | ||
11664 | The @samp{device} and @samp{speed} commands are available only when you | |
11665 | use a Unix host to debug your Hitachi microprocessor programs. If you | |
11666 | use a DOS host, | |
11667 | @value{GDBN} depends on an auxiliary terminate-and-stay-resident program | |
11668 | called @code{asynctsr} to communicate with the development board | |
11669 | through a PC serial port. You must also use the DOS @code{mode} command | |
11670 | to set up the serial port on the DOS side. | |
11671 | ||
11672 | The following sample session illustrates the steps needed to start a | |
11673 | program under @value{GDBN} control on an H8/300. The example uses a | |
11674 | sample H8/300 program called @file{t.x}. The procedure is the same for | |
11675 | the Hitachi SH and the H8/500. | |
11676 | ||
11677 | First hook up your development board. In this example, we use a | |
11678 | board attached to serial port @code{COM2}; if you use a different serial | |
11679 | port, substitute its name in the argument of the @code{mode} command. | |
11680 | When you call @code{asynctsr}, the auxiliary comms program used by the | |
11681 | debugger, you give it just the numeric part of the serial port's name; | |
11682 | for example, @samp{asyncstr 2} below runs @code{asyncstr} on | |
11683 | @code{COM2}. | |
11684 | ||
474c8240 | 11685 | @smallexample |
8e04817f AC |
11686 | C:\H8300\TEST> asynctsr 2 |
11687 | C:\H8300\TEST> mode com2:9600,n,8,1,p | |
11688 | ||
11689 | Resident portion of MODE loaded | |
11690 | ||
11691 | COM2: 9600, n, 8, 1, p | |
11692 | ||
474c8240 | 11693 | @end smallexample |
8e04817f AC |
11694 | |
11695 | @quotation | |
11696 | @emph{Warning:} We have noticed a bug in PC-NFS that conflicts with | |
11697 | @code{asynctsr}. If you also run PC-NFS on your DOS host, you may need to | |
11698 | disable it, or even boot without it, to use @code{asynctsr} to control | |
11699 | your development board. | |
11700 | @end quotation | |
11701 | ||
11702 | @kindex target hms@r{, and serial protocol} | |
11703 | Now that serial communications are set up, and the development board is | |
11704 | connected, you can start up @value{GDBN}. Call @code{@value{GDBP}} with | |
11705 | the name of your program as the argument. @code{@value{GDBN}} prompts | |
11706 | you, as usual, with the prompt @samp{(@value{GDBP})}. Use two special | |
11707 | commands to begin your debugging session: @samp{target hms} to specify | |
11708 | cross-debugging to the Hitachi board, and the @code{load} command to | |
11709 | download your program to the board. @code{load} displays the names of | |
11710 | the program's sections, and a @samp{*} for each 2K of data downloaded. | |
11711 | (If you want to refresh @value{GDBN} data on symbols or on the | |
11712 | executable file without downloading, use the @value{GDBN} commands | |
11713 | @code{file} or @code{symbol-file}. These commands, and @code{load} | |
11714 | itself, are described in @ref{Files,,Commands to specify files}.) | |
11715 | ||
11716 | @smallexample | |
11717 | (eg-C:\H8300\TEST) @value{GDBP} t.x | |
11718 | @value{GDBN} is free software and you are welcome to distribute copies | |
11719 | of it under certain conditions; type "show copying" to see | |
11720 | the conditions. | |
11721 | There is absolutely no warranty for @value{GDBN}; type "show warranty" | |
11722 | for details. | |
11723 | @value{GDBN} @value{GDBVN}, Copyright 1992 Free Software Foundation, Inc... | |
11724 | (@value{GDBP}) target hms | |
11725 | Connected to remote H8/300 HMS system. | |
11726 | (@value{GDBP}) load t.x | |
11727 | .text : 0x8000 .. 0xabde *********** | |
11728 | .data : 0xabde .. 0xad30 * | |
11729 | .stack : 0xf000 .. 0xf014 * | |
11730 | @end smallexample | |
11731 | ||
11732 | At this point, you're ready to run or debug your program. From here on, | |
11733 | you can use all the usual @value{GDBN} commands. The @code{break} command | |
11734 | sets breakpoints; the @code{run} command starts your program; | |
11735 | @code{print} or @code{x} display data; the @code{continue} command | |
11736 | resumes execution after stopping at a breakpoint. You can use the | |
11737 | @code{help} command at any time to find out more about @value{GDBN} commands. | |
11738 | ||
11739 | Remember, however, that @emph{operating system} facilities aren't | |
11740 | available on your development board; for example, if your program hangs, | |
11741 | you can't send an interrupt---but you can press the @sc{reset} switch! | |
11742 | ||
11743 | Use the @sc{reset} button on the development board | |
11744 | @itemize @bullet | |
11745 | @item | |
11746 | to interrupt your program (don't use @kbd{ctl-C} on the DOS host---it has | |
11747 | no way to pass an interrupt signal to the development board); and | |
11748 | ||
11749 | @item | |
11750 | to return to the @value{GDBN} command prompt after your program finishes | |
11751 | normally. The communications protocol provides no other way for @value{GDBN} | |
11752 | to detect program completion. | |
11753 | @end itemize | |
11754 | ||
11755 | In either case, @value{GDBN} sees the effect of a @sc{reset} on the | |
11756 | development board as a ``normal exit'' of your program. | |
11757 | ||
11758 | @node Hitachi ICE | |
11759 | @subsubsection Using the E7000 in-circuit emulator | |
11760 | ||
11761 | @kindex target e7000@r{, with Hitachi ICE} | |
11762 | You can use the E7000 in-circuit emulator to develop code for either the | |
11763 | Hitachi SH or the H8/300H. Use one of these forms of the @samp{target | |
11764 | e7000} command to connect @value{GDBN} to your E7000: | |
11765 | ||
11766 | @table @code | |
11767 | @item target e7000 @var{port} @var{speed} | |
11768 | Use this form if your E7000 is connected to a serial port. The | |
11769 | @var{port} argument identifies what serial port to use (for example, | |
11770 | @samp{com2}). The third argument is the line speed in bits per second | |
11771 | (for example, @samp{9600}). | |
11772 | ||
11773 | @item target e7000 @var{hostname} | |
11774 | If your E7000 is installed as a host on a TCP/IP network, you can just | |
11775 | specify its hostname; @value{GDBN} uses @code{telnet} to connect. | |
11776 | @end table | |
11777 | ||
11778 | @node Hitachi Special | |
11779 | @subsubsection Special @value{GDBN} commands for Hitachi micros | |
11780 | ||
11781 | Some @value{GDBN} commands are available only for the H8/300: | |
11782 | ||
11783 | @table @code | |
11784 | ||
11785 | @kindex set machine | |
11786 | @kindex show machine | |
11787 | @item set machine h8300 | |
11788 | @itemx set machine h8300h | |
11789 | Condition @value{GDBN} for one of the two variants of the H8/300 | |
11790 | architecture with @samp{set machine}. You can use @samp{show machine} | |
11791 | to check which variant is currently in effect. | |
104c1213 JM |
11792 | |
11793 | @end table | |
11794 | ||
8e04817f AC |
11795 | @node H8/500 |
11796 | @subsection H8/500 | |
104c1213 JM |
11797 | |
11798 | @table @code | |
11799 | ||
8e04817f AC |
11800 | @kindex set memory @var{mod} |
11801 | @cindex memory models, H8/500 | |
11802 | @item set memory @var{mod} | |
11803 | @itemx show memory | |
11804 | Specify which H8/500 memory model (@var{mod}) you are using with | |
11805 | @samp{set memory}; check which memory model is in effect with @samp{show | |
11806 | memory}. The accepted values for @var{mod} are @code{small}, | |
11807 | @code{big}, @code{medium}, and @code{compact}. | |
104c1213 | 11808 | |
8e04817f | 11809 | @end table |
104c1213 | 11810 | |
8e04817f AC |
11811 | @node M32R/D |
11812 | @subsection Mitsubishi M32R/D | |
11813 | ||
11814 | @table @code | |
11815 | ||
11816 | @kindex target m32r | |
11817 | @item target m32r @var{dev} | |
11818 | Mitsubishi M32R/D ROM monitor. | |
11819 | ||
11820 | @end table | |
11821 | ||
11822 | @node M68K | |
11823 | @subsection M68k | |
11824 | ||
11825 | The Motorola m68k configuration includes ColdFire support, and | |
11826 | target command for the following ROM monitors. | |
11827 | ||
11828 | @table @code | |
11829 | ||
11830 | @kindex target abug | |
11831 | @item target abug @var{dev} | |
11832 | ABug ROM monitor for M68K. | |
11833 | ||
11834 | @kindex target cpu32bug | |
11835 | @item target cpu32bug @var{dev} | |
11836 | CPU32BUG monitor, running on a CPU32 (M68K) board. | |
11837 | ||
11838 | @kindex target dbug | |
11839 | @item target dbug @var{dev} | |
11840 | dBUG ROM monitor for Motorola ColdFire. | |
11841 | ||
11842 | @kindex target est | |
11843 | @item target est @var{dev} | |
11844 | EST-300 ICE monitor, running on a CPU32 (M68K) board. | |
11845 | ||
11846 | @kindex target rom68k | |
11847 | @item target rom68k @var{dev} | |
11848 | ROM 68K monitor, running on an M68K IDP board. | |
11849 | ||
11850 | @end table | |
11851 | ||
8e04817f AC |
11852 | @table @code |
11853 | ||
11854 | @kindex target rombug | |
11855 | @item target rombug @var{dev} | |
11856 | ROMBUG ROM monitor for OS/9000. | |
11857 | ||
11858 | @end table | |
11859 | ||
8e04817f AC |
11860 | @node MIPS Embedded |
11861 | @subsection MIPS Embedded | |
11862 | ||
11863 | @cindex MIPS boards | |
11864 | @value{GDBN} can use the MIPS remote debugging protocol to talk to a | |
11865 | MIPS board attached to a serial line. This is available when | |
11866 | you configure @value{GDBN} with @samp{--target=mips-idt-ecoff}. | |
104c1213 | 11867 | |
8e04817f AC |
11868 | @need 1000 |
11869 | Use these @value{GDBN} commands to specify the connection to your target board: | |
104c1213 | 11870 | |
8e04817f AC |
11871 | @table @code |
11872 | @item target mips @var{port} | |
11873 | @kindex target mips @var{port} | |
11874 | To run a program on the board, start up @code{@value{GDBP}} with the | |
11875 | name of your program as the argument. To connect to the board, use the | |
11876 | command @samp{target mips @var{port}}, where @var{port} is the name of | |
11877 | the serial port connected to the board. If the program has not already | |
11878 | been downloaded to the board, you may use the @code{load} command to | |
11879 | download it. You can then use all the usual @value{GDBN} commands. | |
104c1213 | 11880 | |
8e04817f AC |
11881 | For example, this sequence connects to the target board through a serial |
11882 | port, and loads and runs a program called @var{prog} through the | |
11883 | debugger: | |
104c1213 | 11884 | |
474c8240 | 11885 | @smallexample |
8e04817f AC |
11886 | host$ @value{GDBP} @var{prog} |
11887 | @value{GDBN} is free software and @dots{} | |
11888 | (@value{GDBP}) target mips /dev/ttyb | |
11889 | (@value{GDBP}) load @var{prog} | |
11890 | (@value{GDBP}) run | |
474c8240 | 11891 | @end smallexample |
104c1213 | 11892 | |
8e04817f AC |
11893 | @item target mips @var{hostname}:@var{portnumber} |
11894 | On some @value{GDBN} host configurations, you can specify a TCP | |
11895 | connection (for instance, to a serial line managed by a terminal | |
11896 | concentrator) instead of a serial port, using the syntax | |
11897 | @samp{@var{hostname}:@var{portnumber}}. | |
104c1213 | 11898 | |
8e04817f AC |
11899 | @item target pmon @var{port} |
11900 | @kindex target pmon @var{port} | |
11901 | PMON ROM monitor. | |
104c1213 | 11902 | |
8e04817f AC |
11903 | @item target ddb @var{port} |
11904 | @kindex target ddb @var{port} | |
11905 | NEC's DDB variant of PMON for Vr4300. | |
104c1213 | 11906 | |
8e04817f AC |
11907 | @item target lsi @var{port} |
11908 | @kindex target lsi @var{port} | |
11909 | LSI variant of PMON. | |
104c1213 | 11910 | |
8e04817f AC |
11911 | @kindex target r3900 |
11912 | @item target r3900 @var{dev} | |
11913 | Densan DVE-R3900 ROM monitor for Toshiba R3900 Mips. | |
104c1213 | 11914 | |
8e04817f AC |
11915 | @kindex target array |
11916 | @item target array @var{dev} | |
11917 | Array Tech LSI33K RAID controller board. | |
104c1213 | 11918 | |
8e04817f | 11919 | @end table |
104c1213 | 11920 | |
104c1213 | 11921 | |
8e04817f AC |
11922 | @noindent |
11923 | @value{GDBN} also supports these special commands for MIPS targets: | |
104c1213 | 11924 | |
8e04817f AC |
11925 | @table @code |
11926 | @item set processor @var{args} | |
11927 | @itemx show processor | |
11928 | @kindex set processor @var{args} | |
11929 | @kindex show processor | |
11930 | Use the @code{set processor} command to set the type of MIPS | |
11931 | processor when you want to access processor-type-specific registers. | |
11932 | For example, @code{set processor @var{r3041}} tells @value{GDBN} | |
11933 | to use the CPU registers appropriate for the 3041 chip. | |
11934 | Use the @code{show processor} command to see what MIPS processor @value{GDBN} | |
11935 | is using. Use the @code{info reg} command to see what registers | |
11936 | @value{GDBN} is using. | |
104c1213 | 11937 | |
8e04817f AC |
11938 | @item set mipsfpu double |
11939 | @itemx set mipsfpu single | |
11940 | @itemx set mipsfpu none | |
11941 | @itemx show mipsfpu | |
11942 | @kindex set mipsfpu | |
11943 | @kindex show mipsfpu | |
11944 | @cindex MIPS remote floating point | |
11945 | @cindex floating point, MIPS remote | |
11946 | If your target board does not support the MIPS floating point | |
11947 | coprocessor, you should use the command @samp{set mipsfpu none} (if you | |
11948 | need this, you may wish to put the command in your @value{GDBN} init | |
11949 | file). This tells @value{GDBN} how to find the return value of | |
11950 | functions which return floating point values. It also allows | |
11951 | @value{GDBN} to avoid saving the floating point registers when calling | |
11952 | functions on the board. If you are using a floating point coprocessor | |
11953 | with only single precision floating point support, as on the @sc{r4650} | |
11954 | processor, use the command @samp{set mipsfpu single}. The default | |
11955 | double precision floating point coprocessor may be selected using | |
11956 | @samp{set mipsfpu double}. | |
104c1213 | 11957 | |
8e04817f AC |
11958 | In previous versions the only choices were double precision or no |
11959 | floating point, so @samp{set mipsfpu on} will select double precision | |
11960 | and @samp{set mipsfpu off} will select no floating point. | |
104c1213 | 11961 | |
8e04817f AC |
11962 | As usual, you can inquire about the @code{mipsfpu} variable with |
11963 | @samp{show mipsfpu}. | |
104c1213 | 11964 | |
8e04817f AC |
11965 | @item set remotedebug @var{n} |
11966 | @itemx show remotedebug | |
11967 | @kindex set remotedebug@r{, MIPS protocol} | |
11968 | @kindex show remotedebug@r{, MIPS protocol} | |
11969 | @cindex @code{remotedebug}, MIPS protocol | |
11970 | @cindex MIPS @code{remotedebug} protocol | |
11971 | @c FIXME! For this to be useful, you must know something about the MIPS | |
11972 | @c FIXME...protocol. Where is it described? | |
11973 | You can see some debugging information about communications with the board | |
11974 | by setting the @code{remotedebug} variable. If you set it to @code{1} using | |
11975 | @samp{set remotedebug 1}, every packet is displayed. If you set it | |
11976 | to @code{2}, every character is displayed. You can check the current value | |
11977 | at any time with the command @samp{show remotedebug}. | |
104c1213 | 11978 | |
8e04817f AC |
11979 | @item set timeout @var{seconds} |
11980 | @itemx set retransmit-timeout @var{seconds} | |
11981 | @itemx show timeout | |
11982 | @itemx show retransmit-timeout | |
11983 | @cindex @code{timeout}, MIPS protocol | |
11984 | @cindex @code{retransmit-timeout}, MIPS protocol | |
11985 | @kindex set timeout | |
11986 | @kindex show timeout | |
11987 | @kindex set retransmit-timeout | |
11988 | @kindex show retransmit-timeout | |
11989 | You can control the timeout used while waiting for a packet, in the MIPS | |
11990 | remote protocol, with the @code{set timeout @var{seconds}} command. The | |
11991 | default is 5 seconds. Similarly, you can control the timeout used while | |
11992 | waiting for an acknowledgement of a packet with the @code{set | |
11993 | retransmit-timeout @var{seconds}} command. The default is 3 seconds. | |
11994 | You can inspect both values with @code{show timeout} and @code{show | |
11995 | retransmit-timeout}. (These commands are @emph{only} available when | |
11996 | @value{GDBN} is configured for @samp{--target=mips-idt-ecoff}.) | |
104c1213 | 11997 | |
8e04817f AC |
11998 | The timeout set by @code{set timeout} does not apply when @value{GDBN} |
11999 | is waiting for your program to stop. In that case, @value{GDBN} waits | |
12000 | forever because it has no way of knowing how long the program is going | |
12001 | to run before stopping. | |
12002 | @end table | |
104c1213 | 12003 | |
a37295f9 MM |
12004 | @node OpenRISC 1000 |
12005 | @subsection OpenRISC 1000 | |
12006 | @cindex OpenRISC 1000 | |
12007 | ||
12008 | @cindex or1k boards | |
12009 | See OR1k Architecture document (@uref{www.opencores.org}) for more information | |
12010 | about platform and commands. | |
12011 | ||
12012 | @table @code | |
12013 | ||
12014 | @kindex target jtag | |
12015 | @item target jtag jtag://@var{host}:@var{port} | |
12016 | ||
12017 | Connects to remote JTAG server. | |
12018 | JTAG remote server can be either an or1ksim or JTAG server, | |
12019 | connected via parallel port to the board. | |
12020 | ||
12021 | Example: @code{target jtag jtag://localhost:9999} | |
12022 | ||
12023 | @kindex or1ksim | |
12024 | @item or1ksim @var{command} | |
12025 | If connected to @code{or1ksim} OpenRISC 1000 Architectural | |
12026 | Simulator, proprietary commands can be executed. | |
12027 | ||
12028 | @kindex info or1k spr | |
12029 | @item info or1k spr | |
12030 | Displays spr groups. | |
12031 | ||
12032 | @item info or1k spr @var{group} | |
12033 | @itemx info or1k spr @var{groupno} | |
12034 | Displays register names in selected group. | |
12035 | ||
12036 | @item info or1k spr @var{group} @var{register} | |
12037 | @itemx info or1k spr @var{register} | |
12038 | @itemx info or1k spr @var{groupno} @var{registerno} | |
12039 | @itemx info or1k spr @var{registerno} | |
12040 | Shows information about specified spr register. | |
12041 | ||
12042 | @kindex spr | |
12043 | @item spr @var{group} @var{register} @var{value} | |
12044 | @itemx spr @var{register @var{value}} | |
12045 | @itemx spr @var{groupno} @var{registerno @var{value}} | |
12046 | @itemx spr @var{registerno @var{value}} | |
12047 | Writes @var{value} to specified spr register. | |
12048 | @end table | |
12049 | ||
12050 | Some implementations of OpenRISC 1000 Architecture also have hardware trace. | |
12051 | It is very similar to @value{GDBN} trace, except it does not interfere with normal | |
12052 | program execution and is thus much faster. Hardware breakpoints/watchpoint | |
12053 | triggers can be set using: | |
12054 | @table @code | |
12055 | @item $LEA/$LDATA | |
12056 | Load effective address/data | |
12057 | @item $SEA/$SDATA | |
12058 | Store effective address/data | |
12059 | @item $AEA/$ADATA | |
12060 | Access effective address ($SEA or $LEA) or data ($SDATA/$LDATA) | |
12061 | @item $FETCH | |
12062 | Fetch data | |
12063 | @end table | |
12064 | ||
12065 | When triggered, it can capture low level data, like: @code{PC}, @code{LSEA}, | |
12066 | @code{LDATA}, @code{SDATA}, @code{READSPR}, @code{WRITESPR}, @code{INSTR}. | |
12067 | ||
12068 | @code{htrace} commands: | |
12069 | @cindex OpenRISC 1000 htrace | |
12070 | @table @code | |
12071 | @kindex hwatch | |
12072 | @item hwatch @var{conditional} | |
12073 | Set hardware watchpoint on combination of Load/Store Effecive Address(es) | |
12074 | or Data. For example: | |
12075 | ||
12076 | @code{hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) && ($SDATA >= 50)} | |
12077 | ||
12078 | @code{hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) && ($SDATA >= 50)} | |
12079 | ||
12080 | @kindex htrace info | |
12081 | @item htrace info | |
12082 | Display information about current HW trace configuration. | |
12083 | ||
12084 | @kindex htrace trigger | |
12085 | @item htrace trigger @var{conditional} | |
12086 | Set starting criteria for HW trace. | |
12087 | ||
12088 | @kindex htrace qualifier | |
12089 | @item htrace qualifier @var{conditional} | |
12090 | Set acquisition qualifier for HW trace. | |
12091 | ||
12092 | @kindex htrace stop | |
12093 | @item htrace stop @var{conditional} | |
12094 | Set HW trace stopping criteria. | |
12095 | ||
12096 | @kindex htrace record | |
f153cc92 | 12097 | @item htrace record [@var{data}]* |
a37295f9 MM |
12098 | Selects the data to be recorded, when qualifier is met and HW trace was |
12099 | triggered. | |
12100 | ||
12101 | @kindex htrace enable | |
12102 | @item htrace enable | |
12103 | @kindex htrace disable | |
12104 | @itemx htrace disable | |
12105 | Enables/disables the HW trace. | |
12106 | ||
12107 | @kindex htrace rewind | |
f153cc92 | 12108 | @item htrace rewind [@var{filename}] |
a37295f9 MM |
12109 | Clears currently recorded trace data. |
12110 | ||
12111 | If filename is specified, new trace file is made and any newly collected data | |
12112 | will be written there. | |
12113 | ||
12114 | @kindex htrace print | |
f153cc92 | 12115 | @item htrace print [@var{start} [@var{len}]] |
a37295f9 MM |
12116 | Prints trace buffer, using current record configuration. |
12117 | ||
12118 | @kindex htrace mode continuous | |
12119 | @item htrace mode continuous | |
12120 | Set continuous trace mode. | |
12121 | ||
12122 | @kindex htrace mode suspend | |
12123 | @item htrace mode suspend | |
12124 | Set suspend trace mode. | |
12125 | ||
12126 | @end table | |
12127 | ||
8e04817f AC |
12128 | @node PowerPC |
12129 | @subsection PowerPC | |
104c1213 JM |
12130 | |
12131 | @table @code | |
104c1213 | 12132 | |
8e04817f AC |
12133 | @kindex target dink32 |
12134 | @item target dink32 @var{dev} | |
12135 | DINK32 ROM monitor. | |
104c1213 | 12136 | |
8e04817f AC |
12137 | @kindex target ppcbug |
12138 | @item target ppcbug @var{dev} | |
12139 | @kindex target ppcbug1 | |
12140 | @item target ppcbug1 @var{dev} | |
12141 | PPCBUG ROM monitor for PowerPC. | |
104c1213 | 12142 | |
8e04817f AC |
12143 | @kindex target sds |
12144 | @item target sds @var{dev} | |
12145 | SDS monitor, running on a PowerPC board (such as Motorola's ADS). | |
12146 | ||
12147 | @end table | |
12148 | ||
12149 | @node PA | |
12150 | @subsection HP PA Embedded | |
104c1213 JM |
12151 | |
12152 | @table @code | |
12153 | ||
8e04817f AC |
12154 | @kindex target op50n |
12155 | @item target op50n @var{dev} | |
12156 | OP50N monitor, running on an OKI HPPA board. | |
12157 | ||
12158 | @kindex target w89k | |
12159 | @item target w89k @var{dev} | |
12160 | W89K monitor, running on a Winbond HPPA board. | |
104c1213 JM |
12161 | |
12162 | @end table | |
12163 | ||
8e04817f AC |
12164 | @node SH |
12165 | @subsection Hitachi SH | |
104c1213 JM |
12166 | |
12167 | @table @code | |
12168 | ||
8e04817f AC |
12169 | @kindex target hms@r{, with Hitachi SH} |
12170 | @item target hms @var{dev} | |
12171 | A Hitachi SH board attached via serial line to your host. Use special | |
12172 | commands @code{device} and @code{speed} to control the serial line and | |
12173 | the communications speed used. | |
104c1213 | 12174 | |
8e04817f AC |
12175 | @kindex target e7000@r{, with Hitachi SH} |
12176 | @item target e7000 @var{dev} | |
12177 | E7000 emulator for Hitachi SH. | |
104c1213 | 12178 | |
8e04817f AC |
12179 | @kindex target sh3@r{, with SH} |
12180 | @kindex target sh3e@r{, with SH} | |
12181 | @item target sh3 @var{dev} | |
12182 | @item target sh3e @var{dev} | |
12183 | Hitachi SH-3 and SH-3E target systems. | |
104c1213 | 12184 | |
8e04817f | 12185 | @end table |
104c1213 | 12186 | |
8e04817f AC |
12187 | @node Sparclet |
12188 | @subsection Tsqware Sparclet | |
104c1213 | 12189 | |
8e04817f AC |
12190 | @cindex Sparclet |
12191 | ||
12192 | @value{GDBN} enables developers to debug tasks running on | |
12193 | Sparclet targets from a Unix host. | |
12194 | @value{GDBN} uses code that runs on | |
12195 | both the Unix host and on the Sparclet target. The program | |
12196 | @code{@value{GDBP}} is installed and executed on the Unix host. | |
104c1213 | 12197 | |
8e04817f AC |
12198 | @table @code |
12199 | @item remotetimeout @var{args} | |
12200 | @kindex remotetimeout | |
12201 | @value{GDBN} supports the option @code{remotetimeout}. | |
12202 | This option is set by the user, and @var{args} represents the number of | |
12203 | seconds @value{GDBN} waits for responses. | |
104c1213 JM |
12204 | @end table |
12205 | ||
8e04817f AC |
12206 | @cindex compiling, on Sparclet |
12207 | When compiling for debugging, include the options @samp{-g} to get debug | |
12208 | information and @samp{-Ttext} to relocate the program to where you wish to | |
12209 | load it on the target. You may also want to add the options @samp{-n} or | |
12210 | @samp{-N} in order to reduce the size of the sections. Example: | |
104c1213 | 12211 | |
474c8240 | 12212 | @smallexample |
8e04817f | 12213 | sparclet-aout-gcc prog.c -Ttext 0x12010000 -g -o prog -N |
474c8240 | 12214 | @end smallexample |
104c1213 | 12215 | |
8e04817f | 12216 | You can use @code{objdump} to verify that the addresses are what you intended: |
104c1213 | 12217 | |
474c8240 | 12218 | @smallexample |
8e04817f | 12219 | sparclet-aout-objdump --headers --syms prog |
474c8240 | 12220 | @end smallexample |
104c1213 | 12221 | |
8e04817f AC |
12222 | @cindex running, on Sparclet |
12223 | Once you have set | |
12224 | your Unix execution search path to find @value{GDBN}, you are ready to | |
12225 | run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} | |
12226 | (or @code{sparclet-aout-gdb}, depending on your installation). | |
104c1213 | 12227 | |
8e04817f AC |
12228 | @value{GDBN} comes up showing the prompt: |
12229 | ||
474c8240 | 12230 | @smallexample |
8e04817f | 12231 | (gdbslet) |
474c8240 | 12232 | @end smallexample |
104c1213 JM |
12233 | |
12234 | @menu | |
8e04817f AC |
12235 | * Sparclet File:: Setting the file to debug |
12236 | * Sparclet Connection:: Connecting to Sparclet | |
12237 | * Sparclet Download:: Sparclet download | |
12238 | * Sparclet Execution:: Running and debugging | |
104c1213 JM |
12239 | @end menu |
12240 | ||
8e04817f AC |
12241 | @node Sparclet File |
12242 | @subsubsection Setting file to debug | |
104c1213 | 12243 | |
8e04817f | 12244 | The @value{GDBN} command @code{file} lets you choose with program to debug. |
104c1213 | 12245 | |
474c8240 | 12246 | @smallexample |
8e04817f | 12247 | (gdbslet) file prog |
474c8240 | 12248 | @end smallexample |
104c1213 | 12249 | |
8e04817f AC |
12250 | @need 1000 |
12251 | @value{GDBN} then attempts to read the symbol table of @file{prog}. | |
12252 | @value{GDBN} locates | |
12253 | the file by searching the directories listed in the command search | |
12254 | path. | |
12255 | If the file was compiled with debug information (option "-g"), source | |
12256 | files will be searched as well. | |
12257 | @value{GDBN} locates | |
12258 | the source files by searching the directories listed in the directory search | |
12259 | path (@pxref{Environment, ,Your program's environment}). | |
12260 | If it fails | |
12261 | to find a file, it displays a message such as: | |
104c1213 | 12262 | |
474c8240 | 12263 | @smallexample |
8e04817f | 12264 | prog: No such file or directory. |
474c8240 | 12265 | @end smallexample |
104c1213 | 12266 | |
8e04817f AC |
12267 | When this happens, add the appropriate directories to the search paths with |
12268 | the @value{GDBN} commands @code{path} and @code{dir}, and execute the | |
12269 | @code{target} command again. | |
104c1213 | 12270 | |
8e04817f AC |
12271 | @node Sparclet Connection |
12272 | @subsubsection Connecting to Sparclet | |
104c1213 | 12273 | |
8e04817f AC |
12274 | The @value{GDBN} command @code{target} lets you connect to a Sparclet target. |
12275 | To connect to a target on serial port ``@code{ttya}'', type: | |
104c1213 | 12276 | |
474c8240 | 12277 | @smallexample |
8e04817f AC |
12278 | (gdbslet) target sparclet /dev/ttya |
12279 | Remote target sparclet connected to /dev/ttya | |
12280 | main () at ../prog.c:3 | |
474c8240 | 12281 | @end smallexample |
104c1213 | 12282 | |
8e04817f AC |
12283 | @need 750 |
12284 | @value{GDBN} displays messages like these: | |
104c1213 | 12285 | |
474c8240 | 12286 | @smallexample |
8e04817f | 12287 | Connected to ttya. |
474c8240 | 12288 | @end smallexample |
104c1213 | 12289 | |
8e04817f AC |
12290 | @node Sparclet Download |
12291 | @subsubsection Sparclet download | |
104c1213 | 12292 | |
8e04817f AC |
12293 | @cindex download to Sparclet |
12294 | Once connected to the Sparclet target, | |
12295 | you can use the @value{GDBN} | |
12296 | @code{load} command to download the file from the host to the target. | |
12297 | The file name and load offset should be given as arguments to the @code{load} | |
12298 | command. | |
12299 | Since the file format is aout, the program must be loaded to the starting | |
12300 | address. You can use @code{objdump} to find out what this value is. The load | |
12301 | offset is an offset which is added to the VMA (virtual memory address) | |
12302 | of each of the file's sections. | |
12303 | For instance, if the program | |
12304 | @file{prog} was linked to text address 0x1201000, with data at 0x12010160 | |
12305 | and bss at 0x12010170, in @value{GDBN}, type: | |
104c1213 | 12306 | |
474c8240 | 12307 | @smallexample |
8e04817f AC |
12308 | (gdbslet) load prog 0x12010000 |
12309 | Loading section .text, size 0xdb0 vma 0x12010000 | |
474c8240 | 12310 | @end smallexample |
104c1213 | 12311 | |
8e04817f AC |
12312 | If the code is loaded at a different address then what the program was linked |
12313 | to, you may need to use the @code{section} and @code{add-symbol-file} commands | |
12314 | to tell @value{GDBN} where to map the symbol table. | |
12315 | ||
12316 | @node Sparclet Execution | |
12317 | @subsubsection Running and debugging | |
12318 | ||
12319 | @cindex running and debugging Sparclet programs | |
12320 | You can now begin debugging the task using @value{GDBN}'s execution control | |
12321 | commands, @code{b}, @code{step}, @code{run}, etc. See the @value{GDBN} | |
12322 | manual for the list of commands. | |
12323 | ||
474c8240 | 12324 | @smallexample |
8e04817f AC |
12325 | (gdbslet) b main |
12326 | Breakpoint 1 at 0x12010000: file prog.c, line 3. | |
12327 | (gdbslet) run | |
12328 | Starting program: prog | |
12329 | Breakpoint 1, main (argc=1, argv=0xeffff21c) at prog.c:3 | |
12330 | 3 char *symarg = 0; | |
12331 | (gdbslet) step | |
12332 | 4 char *execarg = "hello!"; | |
12333 | (gdbslet) | |
474c8240 | 12334 | @end smallexample |
8e04817f AC |
12335 | |
12336 | @node Sparclite | |
12337 | @subsection Fujitsu Sparclite | |
104c1213 JM |
12338 | |
12339 | @table @code | |
12340 | ||
8e04817f AC |
12341 | @kindex target sparclite |
12342 | @item target sparclite @var{dev} | |
12343 | Fujitsu sparclite boards, used only for the purpose of loading. | |
12344 | You must use an additional command to debug the program. | |
12345 | For example: target remote @var{dev} using @value{GDBN} standard | |
12346 | remote protocol. | |
104c1213 JM |
12347 | |
12348 | @end table | |
12349 | ||
8e04817f AC |
12350 | @node ST2000 |
12351 | @subsection Tandem ST2000 | |
104c1213 | 12352 | |
8e04817f AC |
12353 | @value{GDBN} may be used with a Tandem ST2000 phone switch, running Tandem's |
12354 | STDBUG protocol. | |
104c1213 | 12355 | |
8e04817f AC |
12356 | To connect your ST2000 to the host system, see the manufacturer's |
12357 | manual. Once the ST2000 is physically attached, you can run: | |
104c1213 | 12358 | |
474c8240 | 12359 | @smallexample |
8e04817f | 12360 | target st2000 @var{dev} @var{speed} |
474c8240 | 12361 | @end smallexample |
104c1213 | 12362 | |
8e04817f AC |
12363 | @noindent |
12364 | to establish it as your debugging environment. @var{dev} is normally | |
12365 | the name of a serial device, such as @file{/dev/ttya}, connected to the | |
12366 | ST2000 via a serial line. You can instead specify @var{dev} as a TCP | |
12367 | connection (for example, to a serial line attached via a terminal | |
12368 | concentrator) using the syntax @code{@var{hostname}:@var{portnumber}}. | |
104c1213 | 12369 | |
8e04817f AC |
12370 | The @code{load} and @code{attach} commands are @emph{not} defined for |
12371 | this target; you must load your program into the ST2000 as you normally | |
12372 | would for standalone operation. @value{GDBN} reads debugging information | |
12373 | (such as symbols) from a separate, debugging version of the program | |
12374 | available on your host computer. | |
12375 | @c FIXME!! This is terribly vague; what little content is here is | |
12376 | @c basically hearsay. | |
104c1213 | 12377 | |
8e04817f AC |
12378 | @cindex ST2000 auxiliary commands |
12379 | These auxiliary @value{GDBN} commands are available to help you with the ST2000 | |
12380 | environment: | |
104c1213 | 12381 | |
8e04817f AC |
12382 | @table @code |
12383 | @item st2000 @var{command} | |
12384 | @kindex st2000 @var{cmd} | |
12385 | @cindex STDBUG commands (ST2000) | |
12386 | @cindex commands to STDBUG (ST2000) | |
12387 | Send a @var{command} to the STDBUG monitor. See the manufacturer's | |
12388 | manual for available commands. | |
104c1213 | 12389 | |
8e04817f AC |
12390 | @item connect |
12391 | @cindex connect (to STDBUG) | |
12392 | Connect the controlling terminal to the STDBUG command monitor. When | |
12393 | you are done interacting with STDBUG, typing either of two character | |
12394 | sequences gets you back to the @value{GDBN} command prompt: | |
12395 | @kbd{@key{RET}~.} (Return, followed by tilde and period) or | |
12396 | @kbd{@key{RET}~@key{C-d}} (Return, followed by tilde and control-D). | |
104c1213 JM |
12397 | @end table |
12398 | ||
8e04817f AC |
12399 | @node Z8000 |
12400 | @subsection Zilog Z8000 | |
104c1213 | 12401 | |
8e04817f AC |
12402 | @cindex Z8000 |
12403 | @cindex simulator, Z8000 | |
12404 | @cindex Zilog Z8000 simulator | |
104c1213 | 12405 | |
8e04817f AC |
12406 | When configured for debugging Zilog Z8000 targets, @value{GDBN} includes |
12407 | a Z8000 simulator. | |
12408 | ||
12409 | For the Z8000 family, @samp{target sim} simulates either the Z8002 (the | |
12410 | unsegmented variant of the Z8000 architecture) or the Z8001 (the | |
12411 | segmented variant). The simulator recognizes which architecture is | |
12412 | appropriate by inspecting the object code. | |
104c1213 | 12413 | |
8e04817f AC |
12414 | @table @code |
12415 | @item target sim @var{args} | |
12416 | @kindex sim | |
12417 | @kindex target sim@r{, with Z8000} | |
12418 | Debug programs on a simulated CPU. If the simulator supports setup | |
12419 | options, specify them via @var{args}. | |
104c1213 JM |
12420 | @end table |
12421 | ||
8e04817f AC |
12422 | @noindent |
12423 | After specifying this target, you can debug programs for the simulated | |
12424 | CPU in the same style as programs for your host computer; use the | |
12425 | @code{file} command to load a new program image, the @code{run} command | |
12426 | to run your program, and so on. | |
12427 | ||
12428 | As well as making available all the usual machine registers | |
12429 | (@pxref{Registers, ,Registers}), the Z8000 simulator provides three | |
12430 | additional items of information as specially named registers: | |
104c1213 JM |
12431 | |
12432 | @table @code | |
12433 | ||
8e04817f AC |
12434 | @item cycles |
12435 | Counts clock-ticks in the simulator. | |
104c1213 | 12436 | |
8e04817f AC |
12437 | @item insts |
12438 | Counts instructions run in the simulator. | |
104c1213 | 12439 | |
8e04817f AC |
12440 | @item time |
12441 | Execution time in 60ths of a second. | |
104c1213 | 12442 | |
8e04817f | 12443 | @end table |
104c1213 | 12444 | |
8e04817f AC |
12445 | You can refer to these values in @value{GDBN} expressions with the usual |
12446 | conventions; for example, @w{@samp{b fputc if $cycles>5000}} sets a | |
12447 | conditional breakpoint that suspends only after at least 5000 | |
12448 | simulated clock ticks. | |
104c1213 | 12449 | |
8e04817f AC |
12450 | @node Architectures |
12451 | @section Architectures | |
104c1213 | 12452 | |
8e04817f AC |
12453 | This section describes characteristics of architectures that affect |
12454 | all uses of @value{GDBN} with the architecture, both native and cross. | |
104c1213 | 12455 | |
8e04817f AC |
12456 | @menu |
12457 | * A29K:: | |
12458 | * Alpha:: | |
12459 | * MIPS:: | |
12460 | @end menu | |
104c1213 | 12461 | |
8e04817f AC |
12462 | @node A29K |
12463 | @subsection A29K | |
104c1213 JM |
12464 | |
12465 | @table @code | |
104c1213 | 12466 | |
8e04817f AC |
12467 | @kindex set rstack_high_address |
12468 | @cindex AMD 29K register stack | |
12469 | @cindex register stack, AMD29K | |
12470 | @item set rstack_high_address @var{address} | |
12471 | On AMD 29000 family processors, registers are saved in a separate | |
12472 | @dfn{register stack}. There is no way for @value{GDBN} to determine the | |
12473 | extent of this stack. Normally, @value{GDBN} just assumes that the | |
12474 | stack is ``large enough''. This may result in @value{GDBN} referencing | |
12475 | memory locations that do not exist. If necessary, you can get around | |
12476 | this problem by specifying the ending address of the register stack with | |
12477 | the @code{set rstack_high_address} command. The argument should be an | |
12478 | address, which you probably want to precede with @samp{0x} to specify in | |
12479 | hexadecimal. | |
104c1213 | 12480 | |
8e04817f AC |
12481 | @kindex show rstack_high_address |
12482 | @item show rstack_high_address | |
12483 | Display the current limit of the register stack, on AMD 29000 family | |
12484 | processors. | |
104c1213 | 12485 | |
8e04817f | 12486 | @end table |
104c1213 | 12487 | |
8e04817f AC |
12488 | @node Alpha |
12489 | @subsection Alpha | |
104c1213 | 12490 | |
8e04817f | 12491 | See the following section. |
104c1213 | 12492 | |
8e04817f AC |
12493 | @node MIPS |
12494 | @subsection MIPS | |
104c1213 | 12495 | |
8e04817f AC |
12496 | @cindex stack on Alpha |
12497 | @cindex stack on MIPS | |
12498 | @cindex Alpha stack | |
12499 | @cindex MIPS stack | |
12500 | Alpha- and MIPS-based computers use an unusual stack frame, which | |
12501 | sometimes requires @value{GDBN} to search backward in the object code to | |
12502 | find the beginning of a function. | |
104c1213 | 12503 | |
8e04817f AC |
12504 | @cindex response time, MIPS debugging |
12505 | To improve response time (especially for embedded applications, where | |
12506 | @value{GDBN} may be restricted to a slow serial line for this search) | |
12507 | you may want to limit the size of this search, using one of these | |
12508 | commands: | |
104c1213 | 12509 | |
8e04817f AC |
12510 | @table @code |
12511 | @cindex @code{heuristic-fence-post} (Alpha, MIPS) | |
12512 | @item set heuristic-fence-post @var{limit} | |
12513 | Restrict @value{GDBN} to examining at most @var{limit} bytes in its | |
12514 | search for the beginning of a function. A value of @var{0} (the | |
12515 | default) means there is no limit. However, except for @var{0}, the | |
12516 | larger the limit the more bytes @code{heuristic-fence-post} must search | |
12517 | and therefore the longer it takes to run. | |
104c1213 | 12518 | |
8e04817f AC |
12519 | @item show heuristic-fence-post |
12520 | Display the current limit. | |
12521 | @end table | |
104c1213 JM |
12522 | |
12523 | @noindent | |
8e04817f AC |
12524 | These commands are available @emph{only} when @value{GDBN} is configured |
12525 | for debugging programs on Alpha or MIPS processors. | |
104c1213 | 12526 | |
104c1213 | 12527 | |
8e04817f AC |
12528 | @node Controlling GDB |
12529 | @chapter Controlling @value{GDBN} | |
12530 | ||
12531 | You can alter the way @value{GDBN} interacts with you by using the | |
12532 | @code{set} command. For commands controlling how @value{GDBN} displays | |
12533 | data, see @ref{Print Settings, ,Print settings}. Other settings are | |
12534 | described here. | |
12535 | ||
12536 | @menu | |
12537 | * Prompt:: Prompt | |
12538 | * Editing:: Command editing | |
12539 | * History:: Command history | |
12540 | * Screen Size:: Screen size | |
12541 | * Numbers:: Numbers | |
1e698235 | 12542 | * ABI:: Configuring the current ABI |
8e04817f AC |
12543 | * Messages/Warnings:: Optional warnings and messages |
12544 | * Debugging Output:: Optional messages about internal happenings | |
12545 | @end menu | |
12546 | ||
12547 | @node Prompt | |
12548 | @section Prompt | |
104c1213 | 12549 | |
8e04817f | 12550 | @cindex prompt |
104c1213 | 12551 | |
8e04817f AC |
12552 | @value{GDBN} indicates its readiness to read a command by printing a string |
12553 | called the @dfn{prompt}. This string is normally @samp{(@value{GDBP})}. You | |
12554 | can change the prompt string with the @code{set prompt} command. For | |
12555 | instance, when debugging @value{GDBN} with @value{GDBN}, it is useful to change | |
12556 | the prompt in one of the @value{GDBN} sessions so that you can always tell | |
12557 | which one you are talking to. | |
104c1213 | 12558 | |
8e04817f AC |
12559 | @emph{Note:} @code{set prompt} does not add a space for you after the |
12560 | prompt you set. This allows you to set a prompt which ends in a space | |
12561 | or a prompt that does not. | |
104c1213 | 12562 | |
8e04817f AC |
12563 | @table @code |
12564 | @kindex set prompt | |
12565 | @item set prompt @var{newprompt} | |
12566 | Directs @value{GDBN} to use @var{newprompt} as its prompt string henceforth. | |
104c1213 | 12567 | |
8e04817f AC |
12568 | @kindex show prompt |
12569 | @item show prompt | |
12570 | Prints a line of the form: @samp{Gdb's prompt is: @var{your-prompt}} | |
104c1213 JM |
12571 | @end table |
12572 | ||
8e04817f AC |
12573 | @node Editing |
12574 | @section Command editing | |
12575 | @cindex readline | |
12576 | @cindex command line editing | |
104c1213 | 12577 | |
8e04817f AC |
12578 | @value{GDBN} reads its input commands via the @dfn{readline} interface. This |
12579 | @sc{gnu} library provides consistent behavior for programs which provide a | |
12580 | command line interface to the user. Advantages are @sc{gnu} Emacs-style | |
12581 | or @dfn{vi}-style inline editing of commands, @code{csh}-like history | |
12582 | substitution, and a storage and recall of command history across | |
12583 | debugging sessions. | |
104c1213 | 12584 | |
8e04817f AC |
12585 | You may control the behavior of command line editing in @value{GDBN} with the |
12586 | command @code{set}. | |
104c1213 | 12587 | |
8e04817f AC |
12588 | @table @code |
12589 | @kindex set editing | |
12590 | @cindex editing | |
12591 | @item set editing | |
12592 | @itemx set editing on | |
12593 | Enable command line editing (enabled by default). | |
104c1213 | 12594 | |
8e04817f AC |
12595 | @item set editing off |
12596 | Disable command line editing. | |
104c1213 | 12597 | |
8e04817f AC |
12598 | @kindex show editing |
12599 | @item show editing | |
12600 | Show whether command line editing is enabled. | |
104c1213 JM |
12601 | @end table |
12602 | ||
8e04817f AC |
12603 | @node History |
12604 | @section Command history | |
12605 | ||
12606 | @value{GDBN} can keep track of the commands you type during your | |
12607 | debugging sessions, so that you can be certain of precisely what | |
12608 | happened. Use these commands to manage the @value{GDBN} command | |
12609 | history facility. | |
104c1213 JM |
12610 | |
12611 | @table @code | |
8e04817f AC |
12612 | @cindex history substitution |
12613 | @cindex history file | |
12614 | @kindex set history filename | |
12615 | @kindex GDBHISTFILE | |
12616 | @item set history filename @var{fname} | |
12617 | Set the name of the @value{GDBN} command history file to @var{fname}. | |
12618 | This is the file where @value{GDBN} reads an initial command history | |
12619 | list, and where it writes the command history from this session when it | |
12620 | exits. You can access this list through history expansion or through | |
12621 | the history command editing characters listed below. This file defaults | |
12622 | to the value of the environment variable @code{GDBHISTFILE}, or to | |
12623 | @file{./.gdb_history} (@file{./_gdb_history} on MS-DOS) if this variable | |
12624 | is not set. | |
104c1213 | 12625 | |
8e04817f AC |
12626 | @cindex history save |
12627 | @kindex set history save | |
12628 | @item set history save | |
12629 | @itemx set history save on | |
12630 | Record command history in a file, whose name may be specified with the | |
12631 | @code{set history filename} command. By default, this option is disabled. | |
104c1213 | 12632 | |
8e04817f AC |
12633 | @item set history save off |
12634 | Stop recording command history in a file. | |
104c1213 | 12635 | |
8e04817f AC |
12636 | @cindex history size |
12637 | @kindex set history size | |
12638 | @item set history size @var{size} | |
12639 | Set the number of commands which @value{GDBN} keeps in its history list. | |
12640 | This defaults to the value of the environment variable | |
12641 | @code{HISTSIZE}, or to 256 if this variable is not set. | |
104c1213 JM |
12642 | @end table |
12643 | ||
8e04817f AC |
12644 | @cindex history expansion |
12645 | History expansion assigns special meaning to the character @kbd{!}. | |
12646 | @ifset have-readline-appendices | |
12647 | @xref{Event Designators}. | |
12648 | @end ifset | |
12649 | ||
12650 | Since @kbd{!} is also the logical not operator in C, history expansion | |
12651 | is off by default. If you decide to enable history expansion with the | |
12652 | @code{set history expansion on} command, you may sometimes need to | |
12653 | follow @kbd{!} (when it is used as logical not, in an expression) with | |
12654 | a space or a tab to prevent it from being expanded. The readline | |
12655 | history facilities do not attempt substitution on the strings | |
12656 | @kbd{!=} and @kbd{!(}, even when history expansion is enabled. | |
12657 | ||
12658 | The commands to control history expansion are: | |
104c1213 JM |
12659 | |
12660 | @table @code | |
8e04817f AC |
12661 | @kindex set history expansion |
12662 | @item set history expansion on | |
12663 | @itemx set history expansion | |
12664 | Enable history expansion. History expansion is off by default. | |
104c1213 | 12665 | |
8e04817f AC |
12666 | @item set history expansion off |
12667 | Disable history expansion. | |
104c1213 | 12668 | |
8e04817f AC |
12669 | The readline code comes with more complete documentation of |
12670 | editing and history expansion features. Users unfamiliar with @sc{gnu} Emacs | |
12671 | or @code{vi} may wish to read it. | |
12672 | @ifset have-readline-appendices | |
12673 | @xref{Command Line Editing}. | |
12674 | @end ifset | |
104c1213 | 12675 | |
8e04817f AC |
12676 | @c @group |
12677 | @kindex show history | |
12678 | @item show history | |
12679 | @itemx show history filename | |
12680 | @itemx show history save | |
12681 | @itemx show history size | |
12682 | @itemx show history expansion | |
12683 | These commands display the state of the @value{GDBN} history parameters. | |
12684 | @code{show history} by itself displays all four states. | |
12685 | @c @end group | |
12686 | @end table | |
12687 | ||
12688 | @table @code | |
12689 | @kindex shows | |
12690 | @item show commands | |
12691 | Display the last ten commands in the command history. | |
104c1213 | 12692 | |
8e04817f AC |
12693 | @item show commands @var{n} |
12694 | Print ten commands centered on command number @var{n}. | |
12695 | ||
12696 | @item show commands + | |
12697 | Print ten commands just after the commands last printed. | |
104c1213 JM |
12698 | @end table |
12699 | ||
8e04817f AC |
12700 | @node Screen Size |
12701 | @section Screen size | |
12702 | @cindex size of screen | |
12703 | @cindex pauses in output | |
104c1213 | 12704 | |
8e04817f AC |
12705 | Certain commands to @value{GDBN} may produce large amounts of |
12706 | information output to the screen. To help you read all of it, | |
12707 | @value{GDBN} pauses and asks you for input at the end of each page of | |
12708 | output. Type @key{RET} when you want to continue the output, or @kbd{q} | |
12709 | to discard the remaining output. Also, the screen width setting | |
12710 | determines when to wrap lines of output. Depending on what is being | |
12711 | printed, @value{GDBN} tries to break the line at a readable place, | |
12712 | rather than simply letting it overflow onto the following line. | |
12713 | ||
12714 | Normally @value{GDBN} knows the size of the screen from the terminal | |
12715 | driver software. For example, on Unix @value{GDBN} uses the termcap data base | |
12716 | together with the value of the @code{TERM} environment variable and the | |
12717 | @code{stty rows} and @code{stty cols} settings. If this is not correct, | |
12718 | you can override it with the @code{set height} and @code{set | |
12719 | width} commands: | |
12720 | ||
12721 | @table @code | |
12722 | @kindex set height | |
12723 | @kindex set width | |
12724 | @kindex show width | |
12725 | @kindex show height | |
12726 | @item set height @var{lpp} | |
12727 | @itemx show height | |
12728 | @itemx set width @var{cpl} | |
12729 | @itemx show width | |
12730 | These @code{set} commands specify a screen height of @var{lpp} lines and | |
12731 | a screen width of @var{cpl} characters. The associated @code{show} | |
12732 | commands display the current settings. | |
104c1213 | 12733 | |
8e04817f AC |
12734 | If you specify a height of zero lines, @value{GDBN} does not pause during |
12735 | output no matter how long the output is. This is useful if output is to a | |
12736 | file or to an editor buffer. | |
104c1213 | 12737 | |
8e04817f AC |
12738 | Likewise, you can specify @samp{set width 0} to prevent @value{GDBN} |
12739 | from wrapping its output. | |
104c1213 JM |
12740 | @end table |
12741 | ||
8e04817f AC |
12742 | @node Numbers |
12743 | @section Numbers | |
12744 | @cindex number representation | |
12745 | @cindex entering numbers | |
104c1213 | 12746 | |
8e04817f AC |
12747 | You can always enter numbers in octal, decimal, or hexadecimal in |
12748 | @value{GDBN} by the usual conventions: octal numbers begin with | |
12749 | @samp{0}, decimal numbers end with @samp{.}, and hexadecimal numbers | |
12750 | begin with @samp{0x}. Numbers that begin with none of these are, by | |
12751 | default, entered in base 10; likewise, the default display for | |
12752 | numbers---when no particular format is specified---is base 10. You can | |
12753 | change the default base for both input and output with the @code{set | |
12754 | radix} command. | |
104c1213 | 12755 | |
8e04817f AC |
12756 | @table @code |
12757 | @kindex set input-radix | |
12758 | @item set input-radix @var{base} | |
12759 | Set the default base for numeric input. Supported choices | |
12760 | for @var{base} are decimal 8, 10, or 16. @var{base} must itself be | |
12761 | specified either unambiguously or using the current default radix; for | |
12762 | example, any of | |
104c1213 | 12763 | |
8e04817f AC |
12764 | @smallexample |
12765 | set radix 012 | |
12766 | set radix 10. | |
12767 | set radix 0xa | |
12768 | @end smallexample | |
104c1213 | 12769 | |
8e04817f AC |
12770 | @noindent |
12771 | sets the base to decimal. On the other hand, @samp{set radix 10} | |
12772 | leaves the radix unchanged no matter what it was. | |
104c1213 | 12773 | |
8e04817f AC |
12774 | @kindex set output-radix |
12775 | @item set output-radix @var{base} | |
12776 | Set the default base for numeric display. Supported choices | |
12777 | for @var{base} are decimal 8, 10, or 16. @var{base} must itself be | |
12778 | specified either unambiguously or using the current default radix. | |
104c1213 | 12779 | |
8e04817f AC |
12780 | @kindex show input-radix |
12781 | @item show input-radix | |
12782 | Display the current default base for numeric input. | |
104c1213 | 12783 | |
8e04817f AC |
12784 | @kindex show output-radix |
12785 | @item show output-radix | |
12786 | Display the current default base for numeric display. | |
12787 | @end table | |
104c1213 | 12788 | |
1e698235 DJ |
12789 | @node ABI |
12790 | @section Configuring the current ABI | |
12791 | ||
12792 | @value{GDBN} can determine the @dfn{ABI} (Application Binary Interface) of your | |
12793 | application automatically. However, sometimes you need to override its | |
12794 | conclusions. Use these commands to manage @value{GDBN}'s view of the | |
12795 | current ABI. | |
12796 | ||
98b45e30 DJ |
12797 | @cindex OS ABI |
12798 | @kindex set osabi | |
b4e9345d | 12799 | @kindex show osabi |
98b45e30 DJ |
12800 | |
12801 | One @value{GDBN} configuration can debug binaries for multiple operating | |
12802 | system targets, either via remote debugging or native emulation. | |
12803 | @value{GDBN} will autodetect the @dfn{OS ABI} (Operating System ABI) in use, | |
12804 | but you can override its conclusion using the @code{set osabi} command. | |
12805 | One example where this is useful is in debugging of binaries which use | |
12806 | an alternate C library (e.g.@: @sc{uClibc} for @sc{gnu}/Linux) which does | |
12807 | not have the same identifying marks that the standard C library for your | |
12808 | platform provides. | |
12809 | ||
12810 | @table @code | |
12811 | @item show osabi | |
12812 | Show the OS ABI currently in use. | |
12813 | ||
12814 | @item set osabi | |
12815 | With no argument, show the list of registered available OS ABI's. | |
12816 | ||
12817 | @item set osabi @var{abi} | |
12818 | Set the current OS ABI to @var{abi}. | |
12819 | @end table | |
12820 | ||
1e698235 DJ |
12821 | @cindex float promotion |
12822 | @kindex set coerce-float-to-double | |
12823 | ||
12824 | Generally, the way that an argument of type @code{float} is passed to a | |
12825 | function depends on whether the function is prototyped. For a prototyped | |
12826 | (i.e.@: ANSI/ISO style) function, @code{float} arguments are passed unchanged, | |
12827 | according to the architecture's convention for @code{float}. For unprototyped | |
12828 | (i.e.@: K&R style) functions, @code{float} arguments are first promoted to type | |
12829 | @code{double} and then passed. | |
12830 | ||
12831 | Unfortunately, some forms of debug information do not reliably indicate whether | |
12832 | a function is prototyped. If @value{GDBN} calls a function that is not marked | |
12833 | as prototyped, it consults @kbd{set coerce-float-to-double}. | |
12834 | ||
12835 | @table @code | |
12836 | @item set coerce-float-to-double | |
12837 | @itemx set coerce-float-to-double on | |
12838 | Arguments of type @code{float} will be promoted to @code{double} when passed | |
12839 | to an unprototyped function. This is the default setting. | |
12840 | ||
12841 | @item set coerce-float-to-double off | |
12842 | Arguments of type @code{float} will be passed directly to unprototyped | |
12843 | functions. | |
12844 | @end table | |
12845 | ||
f1212245 DJ |
12846 | @kindex set cp-abi |
12847 | @kindex show cp-abi | |
12848 | @value{GDBN} needs to know the ABI used for your program's C@t{++} | |
12849 | objects. The correct C@t{++} ABI depends on which C@t{++} compiler was | |
12850 | used to build your application. @value{GDBN} only fully supports | |
12851 | programs with a single C@t{++} ABI; if your program contains code using | |
12852 | multiple C@t{++} ABI's or if @value{GDBN} can not identify your | |
12853 | program's ABI correctly, you can tell @value{GDBN} which ABI to use. | |
12854 | Currently supported ABI's include ``gnu-v2'', for @code{g++} versions | |
12855 | before 3.0, ``gnu-v3'', for @code{g++} versions 3.0 and later, and | |
12856 | ``hpaCC'' for the HP ANSI C@t{++} compiler. Other C@t{++} compilers may | |
12857 | use the ``gnu-v2'' or ``gnu-v3'' ABI's as well. The default setting is | |
12858 | ``auto''. | |
12859 | ||
12860 | @table @code | |
12861 | @item show cp-abi | |
12862 | Show the C@t{++} ABI currently in use. | |
12863 | ||
12864 | @item set cp-abi | |
12865 | With no argument, show the list of supported C@t{++} ABI's. | |
12866 | ||
12867 | @item set cp-abi @var{abi} | |
12868 | @itemx set cp-abi auto | |
12869 | Set the current C@t{++} ABI to @var{abi}, or return to automatic detection. | |
12870 | @end table | |
12871 | ||
8e04817f AC |
12872 | @node Messages/Warnings |
12873 | @section Optional warnings and messages | |
104c1213 | 12874 | |
8e04817f AC |
12875 | By default, @value{GDBN} is silent about its inner workings. If you are |
12876 | running on a slow machine, you may want to use the @code{set verbose} | |
12877 | command. This makes @value{GDBN} tell you when it does a lengthy | |
12878 | internal operation, so you will not think it has crashed. | |
104c1213 | 12879 | |
8e04817f AC |
12880 | Currently, the messages controlled by @code{set verbose} are those |
12881 | which announce that the symbol table for a source file is being read; | |
12882 | see @code{symbol-file} in @ref{Files, ,Commands to specify files}. | |
104c1213 | 12883 | |
8e04817f AC |
12884 | @table @code |
12885 | @kindex set verbose | |
12886 | @item set verbose on | |
12887 | Enables @value{GDBN} output of certain informational messages. | |
104c1213 | 12888 | |
8e04817f AC |
12889 | @item set verbose off |
12890 | Disables @value{GDBN} output of certain informational messages. | |
104c1213 | 12891 | |
8e04817f AC |
12892 | @kindex show verbose |
12893 | @item show verbose | |
12894 | Displays whether @code{set verbose} is on or off. | |
12895 | @end table | |
104c1213 | 12896 | |
8e04817f AC |
12897 | By default, if @value{GDBN} encounters bugs in the symbol table of an |
12898 | object file, it is silent; but if you are debugging a compiler, you may | |
12899 | find this information useful (@pxref{Symbol Errors, ,Errors reading | |
12900 | symbol files}). | |
104c1213 | 12901 | |
8e04817f | 12902 | @table @code |
104c1213 | 12903 | |
8e04817f AC |
12904 | @kindex set complaints |
12905 | @item set complaints @var{limit} | |
12906 | Permits @value{GDBN} to output @var{limit} complaints about each type of | |
12907 | unusual symbols before becoming silent about the problem. Set | |
12908 | @var{limit} to zero to suppress all complaints; set it to a large number | |
12909 | to prevent complaints from being suppressed. | |
104c1213 | 12910 | |
8e04817f AC |
12911 | @kindex show complaints |
12912 | @item show complaints | |
12913 | Displays how many symbol complaints @value{GDBN} is permitted to produce. | |
104c1213 | 12914 | |
8e04817f | 12915 | @end table |
104c1213 | 12916 | |
8e04817f AC |
12917 | By default, @value{GDBN} is cautious, and asks what sometimes seems to be a |
12918 | lot of stupid questions to confirm certain commands. For example, if | |
12919 | you try to run a program which is already running: | |
104c1213 | 12920 | |
474c8240 | 12921 | @smallexample |
8e04817f AC |
12922 | (@value{GDBP}) run |
12923 | The program being debugged has been started already. | |
12924 | Start it from the beginning? (y or n) | |
474c8240 | 12925 | @end smallexample |
104c1213 | 12926 | |
8e04817f AC |
12927 | If you are willing to unflinchingly face the consequences of your own |
12928 | commands, you can disable this ``feature'': | |
104c1213 | 12929 | |
8e04817f | 12930 | @table @code |
104c1213 | 12931 | |
8e04817f AC |
12932 | @kindex set confirm |
12933 | @cindex flinching | |
12934 | @cindex confirmation | |
12935 | @cindex stupid questions | |
12936 | @item set confirm off | |
12937 | Disables confirmation requests. | |
104c1213 | 12938 | |
8e04817f AC |
12939 | @item set confirm on |
12940 | Enables confirmation requests (the default). | |
104c1213 | 12941 | |
8e04817f AC |
12942 | @kindex show confirm |
12943 | @item show confirm | |
12944 | Displays state of confirmation requests. | |
12945 | ||
12946 | @end table | |
104c1213 | 12947 | |
8e04817f AC |
12948 | @node Debugging Output |
12949 | @section Optional messages about internal happenings | |
104c1213 | 12950 | @table @code |
8e04817f AC |
12951 | @kindex set debug arch |
12952 | @item set debug arch | |
12953 | Turns on or off display of gdbarch debugging info. The default is off | |
12954 | @kindex show debug arch | |
12955 | @item show debug arch | |
12956 | Displays the current state of displaying gdbarch debugging info. | |
12957 | @kindex set debug event | |
12958 | @item set debug event | |
12959 | Turns on or off display of @value{GDBN} event debugging info. The | |
12960 | default is off. | |
12961 | @kindex show debug event | |
12962 | @item show debug event | |
12963 | Displays the current state of displaying @value{GDBN} event debugging | |
12964 | info. | |
12965 | @kindex set debug expression | |
12966 | @item set debug expression | |
12967 | Turns on or off display of @value{GDBN} expression debugging info. The | |
12968 | default is off. | |
12969 | @kindex show debug expression | |
12970 | @item show debug expression | |
12971 | Displays the current state of displaying @value{GDBN} expression | |
12972 | debugging info. | |
7453dc06 AC |
12973 | @kindex set debug frame |
12974 | @item set debug frame | |
12975 | Turns on or off display of @value{GDBN} frame debugging info. The | |
12976 | default is off. | |
12977 | @kindex show debug frame | |
12978 | @item show debug frame | |
12979 | Displays the current state of displaying @value{GDBN} frame debugging | |
12980 | info. | |
8e04817f AC |
12981 | @kindex set debug overload |
12982 | @item set debug overload | |
12983 | Turns on or off display of @value{GDBN} C@t{++} overload debugging | |
12984 | info. This includes info such as ranking of functions, etc. The default | |
12985 | is off. | |
12986 | @kindex show debug overload | |
12987 | @item show debug overload | |
12988 | Displays the current state of displaying @value{GDBN} C@t{++} overload | |
12989 | debugging info. | |
12990 | @kindex set debug remote | |
12991 | @cindex packets, reporting on stdout | |
12992 | @cindex serial connections, debugging | |
12993 | @item set debug remote | |
12994 | Turns on or off display of reports on all packets sent back and forth across | |
12995 | the serial line to the remote machine. The info is printed on the | |
12996 | @value{GDBN} standard output stream. The default is off. | |
12997 | @kindex show debug remote | |
12998 | @item show debug remote | |
12999 | Displays the state of display of remote packets. | |
13000 | @kindex set debug serial | |
13001 | @item set debug serial | |
13002 | Turns on or off display of @value{GDBN} serial debugging info. The | |
13003 | default is off. | |
13004 | @kindex show debug serial | |
13005 | @item show debug serial | |
13006 | Displays the current state of displaying @value{GDBN} serial debugging | |
13007 | info. | |
13008 | @kindex set debug target | |
13009 | @item set debug target | |
13010 | Turns on or off display of @value{GDBN} target debugging info. This info | |
13011 | includes what is going on at the target level of GDB, as it happens. The | |
13012 | default is off. | |
13013 | @kindex show debug target | |
13014 | @item show debug target | |
13015 | Displays the current state of displaying @value{GDBN} target debugging | |
13016 | info. | |
13017 | @kindex set debug varobj | |
13018 | @item set debug varobj | |
13019 | Turns on or off display of @value{GDBN} variable object debugging | |
13020 | info. The default is off. | |
13021 | @kindex show debug varobj | |
13022 | @item show debug varobj | |
13023 | Displays the current state of displaying @value{GDBN} variable object | |
13024 | debugging info. | |
13025 | @end table | |
104c1213 | 13026 | |
8e04817f AC |
13027 | @node Sequences |
13028 | @chapter Canned Sequences of Commands | |
104c1213 | 13029 | |
8e04817f AC |
13030 | Aside from breakpoint commands (@pxref{Break Commands, ,Breakpoint |
13031 | command lists}), @value{GDBN} provides two ways to store sequences of | |
13032 | commands for execution as a unit: user-defined commands and command | |
13033 | files. | |
104c1213 | 13034 | |
8e04817f AC |
13035 | @menu |
13036 | * Define:: User-defined commands | |
13037 | * Hooks:: User-defined command hooks | |
13038 | * Command Files:: Command files | |
13039 | * Output:: Commands for controlled output | |
13040 | @end menu | |
104c1213 | 13041 | |
8e04817f AC |
13042 | @node Define |
13043 | @section User-defined commands | |
104c1213 | 13044 | |
8e04817f AC |
13045 | @cindex user-defined command |
13046 | A @dfn{user-defined command} is a sequence of @value{GDBN} commands to | |
13047 | which you assign a new name as a command. This is done with the | |
13048 | @code{define} command. User commands may accept up to 10 arguments | |
13049 | separated by whitespace. Arguments are accessed within the user command | |
13050 | via @var{$arg0@dots{}$arg9}. A trivial example: | |
104c1213 | 13051 | |
8e04817f AC |
13052 | @smallexample |
13053 | define adder | |
13054 | print $arg0 + $arg1 + $arg2 | |
13055 | @end smallexample | |
104c1213 JM |
13056 | |
13057 | @noindent | |
8e04817f | 13058 | To execute the command use: |
104c1213 | 13059 | |
8e04817f AC |
13060 | @smallexample |
13061 | adder 1 2 3 | |
13062 | @end smallexample | |
104c1213 | 13063 | |
8e04817f AC |
13064 | @noindent |
13065 | This defines the command @code{adder}, which prints the sum of | |
13066 | its three arguments. Note the arguments are text substitutions, so they may | |
13067 | reference variables, use complex expressions, or even perform inferior | |
13068 | functions calls. | |
104c1213 JM |
13069 | |
13070 | @table @code | |
104c1213 | 13071 | |
8e04817f AC |
13072 | @kindex define |
13073 | @item define @var{commandname} | |
13074 | Define a command named @var{commandname}. If there is already a command | |
13075 | by that name, you are asked to confirm that you want to redefine it. | |
104c1213 | 13076 | |
8e04817f AC |
13077 | The definition of the command is made up of other @value{GDBN} command lines, |
13078 | which are given following the @code{define} command. The end of these | |
13079 | commands is marked by a line containing @code{end}. | |
104c1213 | 13080 | |
8e04817f AC |
13081 | @kindex if |
13082 | @kindex else | |
13083 | @item if | |
13084 | Takes a single argument, which is an expression to evaluate. | |
13085 | It is followed by a series of commands that are executed | |
13086 | only if the expression is true (nonzero). | |
13087 | There can then optionally be a line @code{else}, followed | |
13088 | by a series of commands that are only executed if the expression | |
13089 | was false. The end of the list is marked by a line containing @code{end}. | |
104c1213 | 13090 | |
8e04817f AC |
13091 | @kindex while |
13092 | @item while | |
13093 | The syntax is similar to @code{if}: the command takes a single argument, | |
13094 | which is an expression to evaluate, and must be followed by the commands to | |
13095 | execute, one per line, terminated by an @code{end}. | |
13096 | The commands are executed repeatedly as long as the expression | |
13097 | evaluates to true. | |
104c1213 | 13098 | |
8e04817f AC |
13099 | @kindex document |
13100 | @item document @var{commandname} | |
13101 | Document the user-defined command @var{commandname}, so that it can be | |
13102 | accessed by @code{help}. The command @var{commandname} must already be | |
13103 | defined. This command reads lines of documentation just as @code{define} | |
13104 | reads the lines of the command definition, ending with @code{end}. | |
13105 | After the @code{document} command is finished, @code{help} on command | |
13106 | @var{commandname} displays the documentation you have written. | |
104c1213 | 13107 | |
8e04817f AC |
13108 | You may use the @code{document} command again to change the |
13109 | documentation of a command. Redefining the command with @code{define} | |
13110 | does not change the documentation. | |
104c1213 | 13111 | |
8e04817f AC |
13112 | @kindex help user-defined |
13113 | @item help user-defined | |
13114 | List all user-defined commands, with the first line of the documentation | |
13115 | (if any) for each. | |
104c1213 | 13116 | |
8e04817f AC |
13117 | @kindex show user |
13118 | @item show user | |
13119 | @itemx show user @var{commandname} | |
13120 | Display the @value{GDBN} commands used to define @var{commandname} (but | |
13121 | not its documentation). If no @var{commandname} is given, display the | |
13122 | definitions for all user-defined commands. | |
104c1213 | 13123 | |
20f01a46 DH |
13124 | @kindex show max-user-call-depth |
13125 | @kindex set max-user-call-depth | |
13126 | @item show max-user-call-depth | |
5ca0cb28 DH |
13127 | @itemx set max-user-call-depth |
13128 | The value of @code{max-user-call-depth} controls how many recursion | |
13129 | levels are allowed in user-defined commands before GDB suspects an | |
13130 | infinite recursion and aborts the command. | |
20f01a46 | 13131 | |
104c1213 JM |
13132 | @end table |
13133 | ||
8e04817f AC |
13134 | When user-defined commands are executed, the |
13135 | commands of the definition are not printed. An error in any command | |
13136 | stops execution of the user-defined command. | |
104c1213 | 13137 | |
8e04817f AC |
13138 | If used interactively, commands that would ask for confirmation proceed |
13139 | without asking when used inside a user-defined command. Many @value{GDBN} | |
13140 | commands that normally print messages to say what they are doing omit the | |
13141 | messages when used in a user-defined command. | |
104c1213 | 13142 | |
8e04817f AC |
13143 | @node Hooks |
13144 | @section User-defined command hooks | |
13145 | @cindex command hooks | |
13146 | @cindex hooks, for commands | |
13147 | @cindex hooks, pre-command | |
104c1213 | 13148 | |
8e04817f AC |
13149 | @kindex hook |
13150 | @kindex hook- | |
13151 | You may define @dfn{hooks}, which are a special kind of user-defined | |
13152 | command. Whenever you run the command @samp{foo}, if the user-defined | |
13153 | command @samp{hook-foo} exists, it is executed (with no arguments) | |
13154 | before that command. | |
104c1213 | 13155 | |
8e04817f AC |
13156 | @cindex hooks, post-command |
13157 | @kindex hookpost | |
13158 | @kindex hookpost- | |
13159 | A hook may also be defined which is run after the command you executed. | |
13160 | Whenever you run the command @samp{foo}, if the user-defined command | |
13161 | @samp{hookpost-foo} exists, it is executed (with no arguments) after | |
13162 | that command. Post-execution hooks may exist simultaneously with | |
13163 | pre-execution hooks, for the same command. | |
104c1213 | 13164 | |
8e04817f AC |
13165 | It is valid for a hook to call the command which it hooks. If this |
13166 | occurs, the hook is not re-executed, thereby avoiding infinte recursion. | |
104c1213 | 13167 | |
8e04817f AC |
13168 | @c It would be nice if hookpost could be passed a parameter indicating |
13169 | @c if the command it hooks executed properly or not. FIXME! | |
104c1213 | 13170 | |
8e04817f AC |
13171 | @kindex stop@r{, a pseudo-command} |
13172 | In addition, a pseudo-command, @samp{stop} exists. Defining | |
13173 | (@samp{hook-stop}) makes the associated commands execute every time | |
13174 | execution stops in your program: before breakpoint commands are run, | |
13175 | displays are printed, or the stack frame is printed. | |
104c1213 | 13176 | |
8e04817f AC |
13177 | For example, to ignore @code{SIGALRM} signals while |
13178 | single-stepping, but treat them normally during normal execution, | |
13179 | you could define: | |
104c1213 | 13180 | |
474c8240 | 13181 | @smallexample |
8e04817f AC |
13182 | define hook-stop |
13183 | handle SIGALRM nopass | |
13184 | end | |
104c1213 | 13185 | |
8e04817f AC |
13186 | define hook-run |
13187 | handle SIGALRM pass | |
13188 | end | |
104c1213 | 13189 | |
8e04817f AC |
13190 | define hook-continue |
13191 | handle SIGLARM pass | |
13192 | end | |
474c8240 | 13193 | @end smallexample |
104c1213 | 13194 | |
8e04817f AC |
13195 | As a further example, to hook at the begining and end of the @code{echo} |
13196 | command, and to add extra text to the beginning and end of the message, | |
13197 | you could define: | |
104c1213 | 13198 | |
474c8240 | 13199 | @smallexample |
8e04817f AC |
13200 | define hook-echo |
13201 | echo <<<--- | |
13202 | end | |
104c1213 | 13203 | |
8e04817f AC |
13204 | define hookpost-echo |
13205 | echo --->>>\n | |
13206 | end | |
104c1213 | 13207 | |
8e04817f AC |
13208 | (@value{GDBP}) echo Hello World |
13209 | <<<---Hello World--->>> | |
13210 | (@value{GDBP}) | |
104c1213 | 13211 | |
474c8240 | 13212 | @end smallexample |
104c1213 | 13213 | |
8e04817f AC |
13214 | You can define a hook for any single-word command in @value{GDBN}, but |
13215 | not for command aliases; you should define a hook for the basic command | |
13216 | name, e.g. @code{backtrace} rather than @code{bt}. | |
13217 | @c FIXME! So how does Joe User discover whether a command is an alias | |
13218 | @c or not? | |
13219 | If an error occurs during the execution of your hook, execution of | |
13220 | @value{GDBN} commands stops and @value{GDBN} issues a prompt | |
13221 | (before the command that you actually typed had a chance to run). | |
104c1213 | 13222 | |
8e04817f AC |
13223 | If you try to define a hook which does not match any known command, you |
13224 | get a warning from the @code{define} command. | |
c906108c | 13225 | |
8e04817f AC |
13226 | @node Command Files |
13227 | @section Command files | |
c906108c | 13228 | |
8e04817f AC |
13229 | @cindex command files |
13230 | A command file for @value{GDBN} is a file of lines that are @value{GDBN} | |
13231 | commands. Comments (lines starting with @kbd{#}) may also be included. | |
13232 | An empty line in a command file does nothing; it does not mean to repeat | |
13233 | the last command, as it would from the terminal. | |
c906108c | 13234 | |
8e04817f AC |
13235 | @cindex init file |
13236 | @cindex @file{.gdbinit} | |
13237 | @cindex @file{gdb.ini} | |
13238 | When you start @value{GDBN}, it automatically executes commands from its | |
13239 | @dfn{init files}, normally called @file{.gdbinit}@footnote{The DJGPP | |
13240 | port of @value{GDBN} uses the name @file{gdb.ini} instead, due to the | |
13241 | limitations of file names imposed by DOS filesystems.}. | |
13242 | During startup, @value{GDBN} does the following: | |
c906108c | 13243 | |
8e04817f AC |
13244 | @enumerate |
13245 | @item | |
13246 | Reads the init file (if any) in your home directory@footnote{On | |
13247 | DOS/Windows systems, the home directory is the one pointed to by the | |
13248 | @code{HOME} environment variable.}. | |
c906108c | 13249 | |
8e04817f AC |
13250 | @item |
13251 | Processes command line options and operands. | |
c906108c | 13252 | |
8e04817f AC |
13253 | @item |
13254 | Reads the init file (if any) in the current working directory. | |
c906108c | 13255 | |
8e04817f AC |
13256 | @item |
13257 | Reads command files specified by the @samp{-x} option. | |
13258 | @end enumerate | |
c906108c | 13259 | |
8e04817f AC |
13260 | The init file in your home directory can set options (such as @samp{set |
13261 | complaints}) that affect subsequent processing of command line options | |
13262 | and operands. Init files are not executed if you use the @samp{-nx} | |
13263 | option (@pxref{Mode Options, ,Choosing modes}). | |
c906108c | 13264 | |
8e04817f AC |
13265 | @cindex init file name |
13266 | On some configurations of @value{GDBN}, the init file is known by a | |
13267 | different name (these are typically environments where a specialized | |
13268 | form of @value{GDBN} may need to coexist with other forms, hence a | |
13269 | different name for the specialized version's init file). These are the | |
13270 | environments with special init file names: | |
c906108c | 13271 | |
8e04817f AC |
13272 | @cindex @file{.vxgdbinit} |
13273 | @itemize @bullet | |
13274 | @item | |
13275 | VxWorks (Wind River Systems real-time OS): @file{.vxgdbinit} | |
c906108c | 13276 | |
8e04817f AC |
13277 | @cindex @file{.os68gdbinit} |
13278 | @item | |
13279 | OS68K (Enea Data Systems real-time OS): @file{.os68gdbinit} | |
c906108c | 13280 | |
8e04817f AC |
13281 | @cindex @file{.esgdbinit} |
13282 | @item | |
13283 | ES-1800 (Ericsson Telecom AB M68000 emulator): @file{.esgdbinit} | |
13284 | @end itemize | |
c906108c | 13285 | |
8e04817f AC |
13286 | You can also request the execution of a command file with the |
13287 | @code{source} command: | |
c906108c | 13288 | |
8e04817f AC |
13289 | @table @code |
13290 | @kindex source | |
13291 | @item source @var{filename} | |
13292 | Execute the command file @var{filename}. | |
c906108c SS |
13293 | @end table |
13294 | ||
8e04817f | 13295 | The lines in a command file are executed sequentially. They are not |
a71ec265 DH |
13296 | printed as they are executed. An error in any command terminates |
13297 | execution of the command file and control is returned to the console. | |
c906108c | 13298 | |
8e04817f AC |
13299 | Commands that would ask for confirmation if used interactively proceed |
13300 | without asking when used in a command file. Many @value{GDBN} commands that | |
13301 | normally print messages to say what they are doing omit the messages | |
13302 | when called from command files. | |
c906108c | 13303 | |
8e04817f AC |
13304 | @value{GDBN} also accepts command input from standard input. In this |
13305 | mode, normal output goes to standard output and error output goes to | |
13306 | standard error. Errors in a command file supplied on standard input do | |
13307 | not terminate execution of the command file --- execution continues with | |
13308 | the next command. | |
c906108c | 13309 | |
474c8240 | 13310 | @smallexample |
8e04817f | 13311 | gdb < cmds > log 2>&1 |
474c8240 | 13312 | @end smallexample |
c906108c | 13313 | |
8e04817f AC |
13314 | (The syntax above will vary depending on the shell used.) This example |
13315 | will execute commands from the file @file{cmds}. All output and errors | |
13316 | would be directed to @file{log}. | |
c906108c | 13317 | |
8e04817f AC |
13318 | @node Output |
13319 | @section Commands for controlled output | |
c906108c | 13320 | |
8e04817f AC |
13321 | During the execution of a command file or a user-defined command, normal |
13322 | @value{GDBN} output is suppressed; the only output that appears is what is | |
13323 | explicitly printed by the commands in the definition. This section | |
13324 | describes three commands useful for generating exactly the output you | |
13325 | want. | |
c906108c SS |
13326 | |
13327 | @table @code | |
8e04817f AC |
13328 | @kindex echo |
13329 | @item echo @var{text} | |
13330 | @c I do not consider backslash-space a standard C escape sequence | |
13331 | @c because it is not in ANSI. | |
13332 | Print @var{text}. Nonprinting characters can be included in | |
13333 | @var{text} using C escape sequences, such as @samp{\n} to print a | |
13334 | newline. @strong{No newline is printed unless you specify one.} | |
13335 | In addition to the standard C escape sequences, a backslash followed | |
13336 | by a space stands for a space. This is useful for displaying a | |
13337 | string with spaces at the beginning or the end, since leading and | |
13338 | trailing spaces are otherwise trimmed from all arguments. | |
13339 | To print @samp{@w{ }and foo =@w{ }}, use the command | |
13340 | @samp{echo \@w{ }and foo = \@w{ }}. | |
c906108c | 13341 | |
8e04817f AC |
13342 | A backslash at the end of @var{text} can be used, as in C, to continue |
13343 | the command onto subsequent lines. For example, | |
c906108c | 13344 | |
474c8240 | 13345 | @smallexample |
8e04817f AC |
13346 | echo This is some text\n\ |
13347 | which is continued\n\ | |
13348 | onto several lines.\n | |
474c8240 | 13349 | @end smallexample |
c906108c | 13350 | |
8e04817f | 13351 | produces the same output as |
c906108c | 13352 | |
474c8240 | 13353 | @smallexample |
8e04817f AC |
13354 | echo This is some text\n |
13355 | echo which is continued\n | |
13356 | echo onto several lines.\n | |
474c8240 | 13357 | @end smallexample |
c906108c | 13358 | |
8e04817f AC |
13359 | @kindex output |
13360 | @item output @var{expression} | |
13361 | Print the value of @var{expression} and nothing but that value: no | |
13362 | newlines, no @samp{$@var{nn} = }. The value is not entered in the | |
13363 | value history either. @xref{Expressions, ,Expressions}, for more information | |
13364 | on expressions. | |
c906108c | 13365 | |
8e04817f AC |
13366 | @item output/@var{fmt} @var{expression} |
13367 | Print the value of @var{expression} in format @var{fmt}. You can use | |
13368 | the same formats as for @code{print}. @xref{Output Formats,,Output | |
13369 | formats}, for more information. | |
c906108c | 13370 | |
8e04817f AC |
13371 | @kindex printf |
13372 | @item printf @var{string}, @var{expressions}@dots{} | |
13373 | Print the values of the @var{expressions} under the control of | |
13374 | @var{string}. The @var{expressions} are separated by commas and may be | |
13375 | either numbers or pointers. Their values are printed as specified by | |
13376 | @var{string}, exactly as if your program were to execute the C | |
13377 | subroutine | |
13378 | @c FIXME: the above implies that at least all ANSI C formats are | |
13379 | @c supported, but it isn't true: %E and %G don't work (or so it seems). | |
13380 | @c Either this is a bug, or the manual should document what formats are | |
13381 | @c supported. | |
c906108c | 13382 | |
474c8240 | 13383 | @smallexample |
8e04817f | 13384 | printf (@var{string}, @var{expressions}@dots{}); |
474c8240 | 13385 | @end smallexample |
c906108c | 13386 | |
8e04817f | 13387 | For example, you can print two values in hex like this: |
c906108c | 13388 | |
8e04817f AC |
13389 | @smallexample |
13390 | printf "foo, bar-foo = 0x%x, 0x%x\n", foo, bar-foo | |
13391 | @end smallexample | |
c906108c | 13392 | |
8e04817f AC |
13393 | The only backslash-escape sequences that you can use in the format |
13394 | string are the simple ones that consist of backslash followed by a | |
13395 | letter. | |
c906108c SS |
13396 | @end table |
13397 | ||
21c294e6 AC |
13398 | @node Interpreters |
13399 | @chapter Command Interpreters | |
13400 | @cindex command interpreters | |
13401 | ||
13402 | @value{GDBN} supports multiple command interpreters, and some command | |
13403 | infrastructure to allow users or user interface writers to switch | |
13404 | between interpreters or run commands in other interpreters. | |
13405 | ||
13406 | @value{GDBN} currently supports two command interpreters, the console | |
13407 | interpreter (sometimes called the command-line interpreter or @sc{cli}) | |
13408 | and the machine interface interpreter (or @sc{gdb/mi}). This manual | |
13409 | describes both of these interfaces in great detail. | |
13410 | ||
13411 | By default, @value{GDBN} will start with the console interpreter. | |
13412 | However, the user may choose to start @value{GDBN} with another | |
13413 | interpreter by specifying the @option{-i} or @option{--interpreter} | |
13414 | startup options. Defined interpreters include: | |
13415 | ||
13416 | @table @code | |
13417 | @item console | |
13418 | @cindex console interpreter | |
13419 | The traditional console or command-line interpreter. This is the most often | |
13420 | used interpreter with @value{GDBN}. With no interpreter specified at runtime, | |
13421 | @value{GDBN} will use this interpreter. | |
13422 | ||
13423 | @item mi | |
13424 | @cindex mi interpreter | |
13425 | The newest @sc{gdb/mi} interface (currently @code{mi2}). Used primarily | |
13426 | by programs wishing to use @value{GDBN} as a backend for a debugger GUI | |
13427 | or an IDE. For more information, see @ref{GDB/MI, ,The @sc{gdb/mi} | |
13428 | Interface}. | |
13429 | ||
13430 | @item mi2 | |
13431 | @cindex mi2 interpreter | |
13432 | The current @sc{gdb/mi} interface. | |
13433 | ||
13434 | @item mi1 | |
13435 | @cindex mi1 interpreter | |
13436 | The @sc{gdb/mi} interface included in @value{GDBN} 5.1, 5.2, and 5.3. | |
13437 | ||
13438 | @end table | |
13439 | ||
13440 | @cindex invoke another interpreter | |
13441 | The interpreter being used by @value{GDBN} may not be dynamically | |
13442 | switched at runtime. Although possible, this could lead to a very | |
13443 | precarious situation. Consider an IDE using @sc{gdb/mi}. If a user | |
13444 | enters the command "interpreter-set console" in a console view, | |
13445 | @value{GDBN} would switch to using the console interpreter, rendering | |
13446 | the IDE inoperable! | |
13447 | ||
13448 | @kindex interpreter-exec | |
13449 | Although you may only choose a single interpreter at startup, you may execute | |
13450 | commands in any interpreter from the current interpreter using the appropriate | |
13451 | command. If you are running the console interpreter, simply use the | |
13452 | @code{interpreter-exec} command: | |
13453 | ||
13454 | @smallexample | |
13455 | interpreter-exec mi "-data-list-register-names" | |
13456 | @end smallexample | |
13457 | ||
13458 | @sc{gdb/mi} has a similar command, although it is only available in versions of | |
13459 | @value{GDBN} which support @sc{gdb/mi} version 2 (or greater). | |
13460 | ||
8e04817f AC |
13461 | @node TUI |
13462 | @chapter @value{GDBN} Text User Interface | |
13463 | @cindex TUI | |
c906108c | 13464 | |
8e04817f AC |
13465 | @menu |
13466 | * TUI Overview:: TUI overview | |
13467 | * TUI Keys:: TUI key bindings | |
7cf36c78 | 13468 | * TUI Single Key Mode:: TUI single key mode |
8e04817f AC |
13469 | * TUI Commands:: TUI specific commands |
13470 | * TUI Configuration:: TUI configuration variables | |
13471 | @end menu | |
c906108c | 13472 | |
8e04817f AC |
13473 | The @value{GDBN} Text User Interface, TUI in short, |
13474 | is a terminal interface which uses the @code{curses} library | |
13475 | to show the source file, the assembly output, the program registers | |
13476 | and @value{GDBN} commands in separate text windows. | |
13477 | The TUI is available only when @value{GDBN} is configured | |
13478 | with the @code{--enable-tui} configure option (@pxref{Configure Options}). | |
c906108c | 13479 | |
8e04817f AC |
13480 | @node TUI Overview |
13481 | @section TUI overview | |
c906108c | 13482 | |
8e04817f AC |
13483 | The TUI has two display modes that can be switched while |
13484 | @value{GDBN} runs: | |
c906108c | 13485 | |
8e04817f AC |
13486 | @itemize @bullet |
13487 | @item | |
13488 | A curses (or TUI) mode in which it displays several text | |
13489 | windows on the terminal. | |
c906108c | 13490 | |
8e04817f AC |
13491 | @item |
13492 | A standard mode which corresponds to the @value{GDBN} configured without | |
13493 | the TUI. | |
13494 | @end itemize | |
c906108c | 13495 | |
8e04817f AC |
13496 | In the TUI mode, @value{GDBN} can display several text window |
13497 | on the terminal: | |
c906108c | 13498 | |
8e04817f AC |
13499 | @table @emph |
13500 | @item command | |
13501 | This window is the @value{GDBN} command window with the @value{GDBN} | |
13502 | prompt and the @value{GDBN} outputs. The @value{GDBN} input is still | |
13503 | managed using readline but through the TUI. The @emph{command} | |
13504 | window is always visible. | |
c906108c | 13505 | |
8e04817f AC |
13506 | @item source |
13507 | The source window shows the source file of the program. The current | |
13508 | line as well as active breakpoints are displayed in this window. | |
c906108c | 13509 | |
8e04817f AC |
13510 | @item assembly |
13511 | The assembly window shows the disassembly output of the program. | |
c906108c | 13512 | |
8e04817f AC |
13513 | @item register |
13514 | This window shows the processor registers. It detects when | |
13515 | a register is changed and when this is the case, registers that have | |
13516 | changed are highlighted. | |
c906108c | 13517 | |
c906108c SS |
13518 | @end table |
13519 | ||
269c21fe SC |
13520 | The source and assembly windows show the current program position |
13521 | by highlighting the current line and marking them with the @samp{>} marker. | |
13522 | Breakpoints are also indicated with two markers. A first one | |
13523 | indicates the breakpoint type: | |
13524 | ||
13525 | @table @code | |
13526 | @item B | |
13527 | Breakpoint which was hit at least once. | |
13528 | ||
13529 | @item b | |
13530 | Breakpoint which was never hit. | |
13531 | ||
13532 | @item H | |
13533 | Hardware breakpoint which was hit at least once. | |
13534 | ||
13535 | @item h | |
13536 | Hardware breakpoint which was never hit. | |
13537 | ||
13538 | @end table | |
13539 | ||
13540 | The second marker indicates whether the breakpoint is enabled or not: | |
13541 | ||
13542 | @table @code | |
13543 | @item + | |
13544 | Breakpoint is enabled. | |
13545 | ||
13546 | @item - | |
13547 | Breakpoint is disabled. | |
13548 | ||
13549 | @end table | |
13550 | ||
8e04817f AC |
13551 | The source, assembly and register windows are attached to the thread |
13552 | and the frame position. They are updated when the current thread | |
13553 | changes, when the frame changes or when the program counter changes. | |
13554 | These three windows are arranged by the TUI according to several | |
13555 | layouts. The layout defines which of these three windows are visible. | |
13556 | The following layouts are available: | |
c906108c | 13557 | |
8e04817f AC |
13558 | @itemize @bullet |
13559 | @item | |
13560 | source | |
2df3850c | 13561 | |
8e04817f AC |
13562 | @item |
13563 | assembly | |
13564 | ||
13565 | @item | |
13566 | source and assembly | |
13567 | ||
13568 | @item | |
13569 | source and registers | |
c906108c | 13570 | |
8e04817f AC |
13571 | @item |
13572 | assembly and registers | |
2df3850c | 13573 | |
8e04817f | 13574 | @end itemize |
c906108c | 13575 | |
b7bb15bc SC |
13576 | On top of the command window a status line gives various information |
13577 | concerning the current process begin debugged. The status line is | |
13578 | updated when the information it shows changes. The following fields | |
13579 | are displayed: | |
13580 | ||
13581 | @table @emph | |
13582 | @item target | |
13583 | Indicates the current gdb target | |
13584 | (@pxref{Targets, ,Specifying a Debugging Target}). | |
13585 | ||
13586 | @item process | |
13587 | Gives information about the current process or thread number. | |
13588 | When no process is being debugged, this field is set to @code{No process}. | |
13589 | ||
13590 | @item function | |
13591 | Gives the current function name for the selected frame. | |
13592 | The name is demangled if demangling is turned on (@pxref{Print Settings}). | |
13593 | When there is no symbol corresponding to the current program counter | |
13594 | the string @code{??} is displayed. | |
13595 | ||
13596 | @item line | |
13597 | Indicates the current line number for the selected frame. | |
13598 | When the current line number is not known the string @code{??} is displayed. | |
13599 | ||
13600 | @item pc | |
13601 | Indicates the current program counter address. | |
13602 | ||
13603 | @end table | |
13604 | ||
8e04817f AC |
13605 | @node TUI Keys |
13606 | @section TUI Key Bindings | |
13607 | @cindex TUI key bindings | |
c906108c | 13608 | |
8e04817f AC |
13609 | The TUI installs several key bindings in the readline keymaps |
13610 | (@pxref{Command Line Editing}). | |
13611 | They allow to leave or enter in the TUI mode or they operate | |
7cf36c78 SC |
13612 | directly on the TUI layout and windows. The TUI also provides |
13613 | a @emph{SingleKey} keymap which binds several keys directly to | |
13614 | @value{GDBN} commands. The following key bindings | |
8e04817f | 13615 | are installed for both TUI mode and the @value{GDBN} standard mode. |
c906108c | 13616 | |
8e04817f AC |
13617 | @table @kbd |
13618 | @kindex C-x C-a | |
13619 | @item C-x C-a | |
13620 | @kindex C-x a | |
13621 | @itemx C-x a | |
13622 | @kindex C-x A | |
13623 | @itemx C-x A | |
13624 | Enter or leave the TUI mode. When the TUI mode is left, | |
13625 | the curses window management is left and @value{GDBN} operates using | |
13626 | its standard mode writing on the terminal directly. When the TUI | |
13627 | mode is entered, the control is given back to the curses windows. | |
13628 | The screen is then refreshed. | |
c906108c | 13629 | |
8e04817f AC |
13630 | @kindex C-x 1 |
13631 | @item C-x 1 | |
13632 | Use a TUI layout with only one window. The layout will | |
13633 | either be @samp{source} or @samp{assembly}. When the TUI mode | |
13634 | is not active, it will switch to the TUI mode. | |
2df3850c | 13635 | |
8e04817f | 13636 | Think of this key binding as the Emacs @kbd{C-x 1} binding. |
c906108c | 13637 | |
8e04817f AC |
13638 | @kindex C-x 2 |
13639 | @item C-x 2 | |
13640 | Use a TUI layout with at least two windows. When the current | |
13641 | layout shows already two windows, a next layout with two windows is used. | |
13642 | When a new layout is chosen, one window will always be common to the | |
13643 | previous layout and the new one. | |
c906108c | 13644 | |
8e04817f | 13645 | Think of it as the Emacs @kbd{C-x 2} binding. |
2df3850c | 13646 | |
7cf36c78 SC |
13647 | @kindex C-x s |
13648 | @item C-x s | |
13649 | Use the TUI @emph{SingleKey} keymap that binds single key to gdb commands | |
13650 | (@pxref{TUI Single Key Mode}). | |
13651 | ||
c906108c SS |
13652 | @end table |
13653 | ||
8e04817f | 13654 | The following key bindings are handled only by the TUI mode: |
5d161b24 | 13655 | |
8e04817f AC |
13656 | @table @key |
13657 | @kindex PgUp | |
13658 | @item PgUp | |
13659 | Scroll the active window one page up. | |
c906108c | 13660 | |
8e04817f AC |
13661 | @kindex PgDn |
13662 | @item PgDn | |
13663 | Scroll the active window one page down. | |
c906108c | 13664 | |
8e04817f AC |
13665 | @kindex Up |
13666 | @item Up | |
13667 | Scroll the active window one line up. | |
c906108c | 13668 | |
8e04817f AC |
13669 | @kindex Down |
13670 | @item Down | |
13671 | Scroll the active window one line down. | |
c906108c | 13672 | |
8e04817f AC |
13673 | @kindex Left |
13674 | @item Left | |
13675 | Scroll the active window one column left. | |
c906108c | 13676 | |
8e04817f AC |
13677 | @kindex Right |
13678 | @item Right | |
13679 | Scroll the active window one column right. | |
c906108c | 13680 | |
8e04817f AC |
13681 | @kindex C-L |
13682 | @item C-L | |
13683 | Refresh the screen. | |
c906108c | 13684 | |
8e04817f | 13685 | @end table |
c906108c | 13686 | |
8e04817f AC |
13687 | In the TUI mode, the arrow keys are used by the active window |
13688 | for scrolling. This means they are not available for readline. It is | |
13689 | necessary to use other readline key bindings such as @key{C-p}, @key{C-n}, | |
13690 | @key{C-b} and @key{C-f}. | |
13691 | ||
7cf36c78 SC |
13692 | @node TUI Single Key Mode |
13693 | @section TUI Single Key Mode | |
13694 | @cindex TUI single key mode | |
13695 | ||
13696 | The TUI provides a @emph{SingleKey} mode in which it installs a particular | |
13697 | key binding in the readline keymaps to connect single keys to | |
13698 | some gdb commands. | |
13699 | ||
13700 | @table @kbd | |
13701 | @kindex c @r{(SingleKey TUI key)} | |
13702 | @item c | |
13703 | continue | |
13704 | ||
13705 | @kindex d @r{(SingleKey TUI key)} | |
13706 | @item d | |
13707 | down | |
13708 | ||
13709 | @kindex f @r{(SingleKey TUI key)} | |
13710 | @item f | |
13711 | finish | |
13712 | ||
13713 | @kindex n @r{(SingleKey TUI key)} | |
13714 | @item n | |
13715 | next | |
13716 | ||
13717 | @kindex q @r{(SingleKey TUI key)} | |
13718 | @item q | |
13719 | exit the @emph{SingleKey} mode. | |
13720 | ||
13721 | @kindex r @r{(SingleKey TUI key)} | |
13722 | @item r | |
13723 | run | |
13724 | ||
13725 | @kindex s @r{(SingleKey TUI key)} | |
13726 | @item s | |
13727 | step | |
13728 | ||
13729 | @kindex u @r{(SingleKey TUI key)} | |
13730 | @item u | |
13731 | up | |
13732 | ||
13733 | @kindex v @r{(SingleKey TUI key)} | |
13734 | @item v | |
13735 | info locals | |
13736 | ||
13737 | @kindex w @r{(SingleKey TUI key)} | |
13738 | @item w | |
13739 | where | |
13740 | ||
13741 | @end table | |
13742 | ||
13743 | Other keys temporarily switch to the @value{GDBN} command prompt. | |
13744 | The key that was pressed is inserted in the editing buffer so that | |
13745 | it is possible to type most @value{GDBN} commands without interaction | |
13746 | with the TUI @emph{SingleKey} mode. Once the command is entered the TUI | |
13747 | @emph{SingleKey} mode is restored. The only way to permanently leave | |
13748 | this mode is by hitting @key{q} or @samp{@key{C-x} @key{s}}. | |
13749 | ||
13750 | ||
8e04817f AC |
13751 | @node TUI Commands |
13752 | @section TUI specific commands | |
13753 | @cindex TUI commands | |
13754 | ||
13755 | The TUI has specific commands to control the text windows. | |
13756 | These commands are always available, that is they do not depend on | |
13757 | the current terminal mode in which @value{GDBN} runs. When @value{GDBN} | |
13758 | is in the standard mode, using these commands will automatically switch | |
13759 | in the TUI mode. | |
c906108c SS |
13760 | |
13761 | @table @code | |
3d757584 SC |
13762 | @item info win |
13763 | @kindex info win | |
13764 | List and give the size of all displayed windows. | |
13765 | ||
8e04817f AC |
13766 | @item layout next |
13767 | @kindex layout next | |
13768 | Display the next layout. | |
2df3850c | 13769 | |
8e04817f AC |
13770 | @item layout prev |
13771 | @kindex layout prev | |
13772 | Display the previous layout. | |
c906108c | 13773 | |
8e04817f AC |
13774 | @item layout src |
13775 | @kindex layout src | |
13776 | Display the source window only. | |
c906108c | 13777 | |
8e04817f AC |
13778 | @item layout asm |
13779 | @kindex layout asm | |
13780 | Display the assembly window only. | |
c906108c | 13781 | |
8e04817f AC |
13782 | @item layout split |
13783 | @kindex layout split | |
13784 | Display the source and assembly window. | |
c906108c | 13785 | |
8e04817f AC |
13786 | @item layout regs |
13787 | @kindex layout regs | |
13788 | Display the register window together with the source or assembly window. | |
13789 | ||
13790 | @item focus next | prev | src | asm | regs | split | |
13791 | @kindex focus | |
13792 | Set the focus to the named window. | |
13793 | This command allows to change the active window so that scrolling keys | |
13794 | can be affected to another window. | |
c906108c | 13795 | |
8e04817f AC |
13796 | @item refresh |
13797 | @kindex refresh | |
13798 | Refresh the screen. This is similar to using @key{C-L} key. | |
c906108c | 13799 | |
8e04817f AC |
13800 | @item update |
13801 | @kindex update | |
13802 | Update the source window and the current execution point. | |
c906108c | 13803 | |
8e04817f AC |
13804 | @item winheight @var{name} +@var{count} |
13805 | @itemx winheight @var{name} -@var{count} | |
13806 | @kindex winheight | |
13807 | Change the height of the window @var{name} by @var{count} | |
13808 | lines. Positive counts increase the height, while negative counts | |
13809 | decrease it. | |
2df3850c | 13810 | |
c906108c SS |
13811 | @end table |
13812 | ||
8e04817f AC |
13813 | @node TUI Configuration |
13814 | @section TUI configuration variables | |
13815 | @cindex TUI configuration variables | |
c906108c | 13816 | |
8e04817f AC |
13817 | The TUI has several configuration variables that control the |
13818 | appearance of windows on the terminal. | |
c906108c | 13819 | |
8e04817f AC |
13820 | @table @code |
13821 | @item set tui border-kind @var{kind} | |
13822 | @kindex set tui border-kind | |
13823 | Select the border appearance for the source, assembly and register windows. | |
13824 | The possible values are the following: | |
13825 | @table @code | |
13826 | @item space | |
13827 | Use a space character to draw the border. | |
c906108c | 13828 | |
8e04817f AC |
13829 | @item ascii |
13830 | Use ascii characters + - and | to draw the border. | |
c906108c | 13831 | |
8e04817f AC |
13832 | @item acs |
13833 | Use the Alternate Character Set to draw the border. The border is | |
13834 | drawn using character line graphics if the terminal supports them. | |
c78b4128 | 13835 | |
8e04817f | 13836 | @end table |
c78b4128 | 13837 | |
8e04817f AC |
13838 | @item set tui active-border-mode @var{mode} |
13839 | @kindex set tui active-border-mode | |
13840 | Select the attributes to display the border of the active window. | |
13841 | The possible values are @code{normal}, @code{standout}, @code{reverse}, | |
13842 | @code{half}, @code{half-standout}, @code{bold} and @code{bold-standout}. | |
c78b4128 | 13843 | |
8e04817f AC |
13844 | @item set tui border-mode @var{mode} |
13845 | @kindex set tui border-mode | |
13846 | Select the attributes to display the border of other windows. | |
13847 | The @var{mode} can be one of the following: | |
13848 | @table @code | |
13849 | @item normal | |
13850 | Use normal attributes to display the border. | |
c906108c | 13851 | |
8e04817f AC |
13852 | @item standout |
13853 | Use standout mode. | |
c906108c | 13854 | |
8e04817f AC |
13855 | @item reverse |
13856 | Use reverse video mode. | |
c906108c | 13857 | |
8e04817f AC |
13858 | @item half |
13859 | Use half bright mode. | |
c906108c | 13860 | |
8e04817f AC |
13861 | @item half-standout |
13862 | Use half bright and standout mode. | |
c906108c | 13863 | |
8e04817f AC |
13864 | @item bold |
13865 | Use extra bright or bold mode. | |
c78b4128 | 13866 | |
8e04817f AC |
13867 | @item bold-standout |
13868 | Use extra bright or bold and standout mode. | |
c78b4128 | 13869 | |
8e04817f | 13870 | @end table |
c78b4128 | 13871 | |
8e04817f | 13872 | @end table |
c78b4128 | 13873 | |
8e04817f AC |
13874 | @node Emacs |
13875 | @chapter Using @value{GDBN} under @sc{gnu} Emacs | |
c78b4128 | 13876 | |
8e04817f AC |
13877 | @cindex Emacs |
13878 | @cindex @sc{gnu} Emacs | |
13879 | A special interface allows you to use @sc{gnu} Emacs to view (and | |
13880 | edit) the source files for the program you are debugging with | |
13881 | @value{GDBN}. | |
c906108c | 13882 | |
8e04817f AC |
13883 | To use this interface, use the command @kbd{M-x gdb} in Emacs. Give the |
13884 | executable file you want to debug as an argument. This command starts | |
13885 | @value{GDBN} as a subprocess of Emacs, with input and output through a newly | |
13886 | created Emacs buffer. | |
13887 | @c (Do not use the @code{-tui} option to run @value{GDBN} from Emacs.) | |
c906108c | 13888 | |
8e04817f AC |
13889 | Using @value{GDBN} under Emacs is just like using @value{GDBN} normally except for two |
13890 | things: | |
c906108c | 13891 | |
8e04817f AC |
13892 | @itemize @bullet |
13893 | @item | |
13894 | All ``terminal'' input and output goes through the Emacs buffer. | |
13895 | @end itemize | |
c906108c | 13896 | |
8e04817f AC |
13897 | This applies both to @value{GDBN} commands and their output, and to the input |
13898 | and output done by the program you are debugging. | |
bf0184be | 13899 | |
8e04817f AC |
13900 | This is useful because it means that you can copy the text of previous |
13901 | commands and input them again; you can even use parts of the output | |
13902 | in this way. | |
bf0184be | 13903 | |
8e04817f AC |
13904 | All the facilities of Emacs' Shell mode are available for interacting |
13905 | with your program. In particular, you can send signals the usual | |
13906 | way---for example, @kbd{C-c C-c} for an interrupt, @kbd{C-c C-z} for a | |
13907 | stop. | |
bf0184be | 13908 | |
8e04817f | 13909 | @itemize @bullet |
bf0184be | 13910 | @item |
8e04817f AC |
13911 | @value{GDBN} displays source code through Emacs. |
13912 | @end itemize | |
bf0184be | 13913 | |
8e04817f AC |
13914 | Each time @value{GDBN} displays a stack frame, Emacs automatically finds the |
13915 | source file for that frame and puts an arrow (@samp{=>}) at the | |
13916 | left margin of the current line. Emacs uses a separate buffer for | |
13917 | source display, and splits the screen to show both your @value{GDBN} session | |
13918 | and the source. | |
bf0184be | 13919 | |
8e04817f AC |
13920 | Explicit @value{GDBN} @code{list} or search commands still produce output as |
13921 | usual, but you probably have no reason to use them from Emacs. | |
c906108c | 13922 | |
8e04817f AC |
13923 | @quotation |
13924 | @emph{Warning:} If the directory where your program resides is not your | |
13925 | current directory, it can be easy to confuse Emacs about the location of | |
13926 | the source files, in which case the auxiliary display buffer does not | |
13927 | appear to show your source. @value{GDBN} can find programs by searching your | |
13928 | environment's @code{PATH} variable, so the @value{GDBN} input and output | |
13929 | session proceeds normally; but Emacs does not get enough information | |
13930 | back from @value{GDBN} to locate the source files in this situation. To | |
13931 | avoid this problem, either start @value{GDBN} mode from the directory where | |
13932 | your program resides, or specify an absolute file name when prompted for the | |
13933 | @kbd{M-x gdb} argument. | |
c906108c | 13934 | |
8e04817f AC |
13935 | A similar confusion can result if you use the @value{GDBN} @code{file} command to |
13936 | switch to debugging a program in some other location, from an existing | |
13937 | @value{GDBN} buffer in Emacs. | |
13938 | @end quotation | |
13939 | ||
13940 | By default, @kbd{M-x gdb} calls the program called @file{gdb}. If | |
13941 | you need to call @value{GDBN} by a different name (for example, if you keep | |
13942 | several configurations around, with different names) you can set the | |
13943 | Emacs variable @code{gdb-command-name}; for example, | |
13944 | ||
474c8240 | 13945 | @smallexample |
8e04817f | 13946 | (setq gdb-command-name "mygdb") |
474c8240 | 13947 | @end smallexample |
8e04817f AC |
13948 | |
13949 | @noindent | |
13950 | (preceded by @kbd{M-:} or @kbd{ESC :}, or typed in the @code{*scratch*} buffer, or | |
13951 | in your @file{.emacs} file) makes Emacs call the program named | |
13952 | ``@code{mygdb}'' instead. | |
13953 | ||
13954 | In the @value{GDBN} I/O buffer, you can use these special Emacs commands in | |
13955 | addition to the standard Shell mode commands: | |
c906108c | 13956 | |
8e04817f AC |
13957 | @table @kbd |
13958 | @item C-h m | |
13959 | Describe the features of Emacs' @value{GDBN} Mode. | |
c906108c | 13960 | |
8e04817f AC |
13961 | @item M-s |
13962 | Execute to another source line, like the @value{GDBN} @code{step} command; also | |
13963 | update the display window to show the current file and location. | |
c906108c | 13964 | |
8e04817f AC |
13965 | @item M-n |
13966 | Execute to next source line in this function, skipping all function | |
13967 | calls, like the @value{GDBN} @code{next} command. Then update the display window | |
13968 | to show the current file and location. | |
c906108c | 13969 | |
8e04817f AC |
13970 | @item M-i |
13971 | Execute one instruction, like the @value{GDBN} @code{stepi} command; update | |
13972 | display window accordingly. | |
c906108c | 13973 | |
8e04817f AC |
13974 | @item M-x gdb-nexti |
13975 | Execute to next instruction, using the @value{GDBN} @code{nexti} command; update | |
13976 | display window accordingly. | |
c906108c | 13977 | |
8e04817f AC |
13978 | @item C-c C-f |
13979 | Execute until exit from the selected stack frame, like the @value{GDBN} | |
13980 | @code{finish} command. | |
c906108c | 13981 | |
8e04817f AC |
13982 | @item M-c |
13983 | Continue execution of your program, like the @value{GDBN} @code{continue} | |
13984 | command. | |
b433d00b | 13985 | |
8e04817f | 13986 | @emph{Warning:} In Emacs v19, this command is @kbd{C-c C-p}. |
b433d00b | 13987 | |
8e04817f AC |
13988 | @item M-u |
13989 | Go up the number of frames indicated by the numeric argument | |
13990 | (@pxref{Arguments, , Numeric Arguments, Emacs, The @sc{gnu} Emacs Manual}), | |
13991 | like the @value{GDBN} @code{up} command. | |
b433d00b | 13992 | |
8e04817f | 13993 | @emph{Warning:} In Emacs v19, this command is @kbd{C-c C-u}. |
c906108c | 13994 | |
8e04817f AC |
13995 | @item M-d |
13996 | Go down the number of frames indicated by the numeric argument, like the | |
13997 | @value{GDBN} @code{down} command. | |
c906108c | 13998 | |
8e04817f | 13999 | @emph{Warning:} In Emacs v19, this command is @kbd{C-c C-d}. |
c906108c | 14000 | |
8e04817f AC |
14001 | @item C-x & |
14002 | Read the number where the cursor is positioned, and insert it at the end | |
14003 | of the @value{GDBN} I/O buffer. For example, if you wish to disassemble code | |
14004 | around an address that was displayed earlier, type @kbd{disassemble}; | |
14005 | then move the cursor to the address display, and pick up the | |
14006 | argument for @code{disassemble} by typing @kbd{C-x &}. | |
c906108c | 14007 | |
8e04817f AC |
14008 | You can customize this further by defining elements of the list |
14009 | @code{gdb-print-command}; once it is defined, you can format or | |
14010 | otherwise process numbers picked up by @kbd{C-x &} before they are | |
14011 | inserted. A numeric argument to @kbd{C-x &} indicates that you | |
14012 | wish special formatting, and also acts as an index to pick an element of the | |
14013 | list. If the list element is a string, the number to be inserted is | |
14014 | formatted using the Emacs function @code{format}; otherwise the number | |
14015 | is passed as an argument to the corresponding list element. | |
14016 | @end table | |
c906108c | 14017 | |
8e04817f AC |
14018 | In any source file, the Emacs command @kbd{C-x SPC} (@code{gdb-break}) |
14019 | tells @value{GDBN} to set a breakpoint on the source line point is on. | |
c906108c | 14020 | |
8e04817f AC |
14021 | If you accidentally delete the source-display buffer, an easy way to get |
14022 | it back is to type the command @code{f} in the @value{GDBN} buffer, to | |
14023 | request a frame display; when you run under Emacs, this recreates | |
14024 | the source buffer if necessary to show you the context of the current | |
14025 | frame. | |
c906108c | 14026 | |
8e04817f AC |
14027 | The source files displayed in Emacs are in ordinary Emacs buffers |
14028 | which are visiting the source files in the usual way. You can edit | |
14029 | the files with these buffers if you wish; but keep in mind that @value{GDBN} | |
14030 | communicates with Emacs in terms of line numbers. If you add or | |
14031 | delete lines from the text, the line numbers that @value{GDBN} knows cease | |
14032 | to correspond properly with the code. | |
c906108c | 14033 | |
8e04817f AC |
14034 | @c The following dropped because Epoch is nonstandard. Reactivate |
14035 | @c if/when v19 does something similar. ---doc@cygnus.com 19dec1990 | |
14036 | @ignore | |
14037 | @kindex Emacs Epoch environment | |
14038 | @kindex Epoch | |
14039 | @kindex inspect | |
c906108c | 14040 | |
8e04817f AC |
14041 | Version 18 of @sc{gnu} Emacs has a built-in window system |
14042 | called the @code{epoch} | |
14043 | environment. Users of this environment can use a new command, | |
14044 | @code{inspect} which performs identically to @code{print} except that | |
14045 | each value is printed in its own window. | |
14046 | @end ignore | |
c906108c | 14047 | |
922fbb7b AC |
14048 | |
14049 | @node GDB/MI | |
14050 | @chapter The @sc{gdb/mi} Interface | |
14051 | ||
14052 | @unnumberedsec Function and Purpose | |
14053 | ||
14054 | @cindex @sc{gdb/mi}, its purpose | |
14055 | @sc{gdb/mi} is a line based machine oriented text interface to @value{GDBN}. It is | |
14056 | specifically intended to support the development of systems which use | |
14057 | the debugger as just one small component of a larger system. | |
14058 | ||
14059 | This chapter is a specification of the @sc{gdb/mi} interface. It is written | |
14060 | in the form of a reference manual. | |
14061 | ||
14062 | Note that @sc{gdb/mi} is still under construction, so some of the | |
14063 | features described below are incomplete and subject to change. | |
14064 | ||
14065 | @unnumberedsec Notation and Terminology | |
14066 | ||
14067 | @cindex notational conventions, for @sc{gdb/mi} | |
14068 | This chapter uses the following notation: | |
14069 | ||
14070 | @itemize @bullet | |
14071 | @item | |
14072 | @code{|} separates two alternatives. | |
14073 | ||
14074 | @item | |
14075 | @code{[ @var{something} ]} indicates that @var{something} is optional: | |
14076 | it may or may not be given. | |
14077 | ||
14078 | @item | |
14079 | @code{( @var{group} )*} means that @var{group} inside the parentheses | |
14080 | may repeat zero or more times. | |
14081 | ||
14082 | @item | |
14083 | @code{( @var{group} )+} means that @var{group} inside the parentheses | |
14084 | may repeat one or more times. | |
14085 | ||
14086 | @item | |
14087 | @code{"@var{string}"} means a literal @var{string}. | |
14088 | @end itemize | |
14089 | ||
14090 | @ignore | |
14091 | @heading Dependencies | |
14092 | @end ignore | |
14093 | ||
14094 | @heading Acknowledgments | |
14095 | ||
14096 | In alphabetic order: Andrew Cagney, Fernando Nasser, Stan Shebs and | |
14097 | Elena Zannoni. | |
14098 | ||
14099 | @menu | |
14100 | * GDB/MI Command Syntax:: | |
14101 | * GDB/MI Compatibility with CLI:: | |
14102 | * GDB/MI Output Records:: | |
14103 | * GDB/MI Command Description Format:: | |
14104 | * GDB/MI Breakpoint Table Commands:: | |
14105 | * GDB/MI Data Manipulation:: | |
14106 | * GDB/MI Program Control:: | |
14107 | * GDB/MI Miscellaneous Commands:: | |
14108 | @ignore | |
14109 | * GDB/MI Kod Commands:: | |
14110 | * GDB/MI Memory Overlay Commands:: | |
14111 | * GDB/MI Signal Handling Commands:: | |
14112 | @end ignore | |
14113 | * GDB/MI Stack Manipulation:: | |
14114 | * GDB/MI Symbol Query:: | |
14115 | * GDB/MI Target Manipulation:: | |
14116 | * GDB/MI Thread Commands:: | |
14117 | * GDB/MI Tracepoint Commands:: | |
14118 | * GDB/MI Variable Objects:: | |
14119 | @end menu | |
14120 | ||
14121 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
14122 | @node GDB/MI Command Syntax | |
14123 | @section @sc{gdb/mi} Command Syntax | |
14124 | ||
14125 | @menu | |
14126 | * GDB/MI Input Syntax:: | |
14127 | * GDB/MI Output Syntax:: | |
14128 | * GDB/MI Simple Examples:: | |
14129 | @end menu | |
14130 | ||
14131 | @node GDB/MI Input Syntax | |
14132 | @subsection @sc{gdb/mi} Input Syntax | |
14133 | ||
14134 | @cindex input syntax for @sc{gdb/mi} | |
14135 | @cindex @sc{gdb/mi}, input syntax | |
14136 | @table @code | |
14137 | @item @var{command} @expansion{} | |
14138 | @code{@var{cli-command} | @var{mi-command}} | |
14139 | ||
14140 | @item @var{cli-command} @expansion{} | |
14141 | @code{[ @var{token} ] @var{cli-command} @var{nl}}, where | |
14142 | @var{cli-command} is any existing @value{GDBN} CLI command. | |
14143 | ||
14144 | @item @var{mi-command} @expansion{} | |
14145 | @code{[ @var{token} ] "-" @var{operation} ( " " @var{option} )* | |
14146 | @code{[} " --" @code{]} ( " " @var{parameter} )* @var{nl}} | |
14147 | ||
14148 | @item @var{token} @expansion{} | |
14149 | "any sequence of digits" | |
14150 | ||
14151 | @item @var{option} @expansion{} | |
14152 | @code{"-" @var{parameter} [ " " @var{parameter} ]} | |
14153 | ||
14154 | @item @var{parameter} @expansion{} | |
14155 | @code{@var{non-blank-sequence} | @var{c-string}} | |
14156 | ||
14157 | @item @var{operation} @expansion{} | |
14158 | @emph{any of the operations described in this chapter} | |
14159 | ||
14160 | @item @var{non-blank-sequence} @expansion{} | |
14161 | @emph{anything, provided it doesn't contain special characters such as | |
14162 | "-", @var{nl}, """ and of course " "} | |
14163 | ||
14164 | @item @var{c-string} @expansion{} | |
14165 | @code{""" @var{seven-bit-iso-c-string-content} """} | |
14166 | ||
14167 | @item @var{nl} @expansion{} | |
14168 | @code{CR | CR-LF} | |
14169 | @end table | |
14170 | ||
14171 | @noindent | |
14172 | Notes: | |
14173 | ||
14174 | @itemize @bullet | |
14175 | @item | |
14176 | The CLI commands are still handled by the @sc{mi} interpreter; their | |
14177 | output is described below. | |
14178 | ||
14179 | @item | |
14180 | The @code{@var{token}}, when present, is passed back when the command | |
14181 | finishes. | |
14182 | ||
14183 | @item | |
14184 | Some @sc{mi} commands accept optional arguments as part of the parameter | |
14185 | list. Each option is identified by a leading @samp{-} (dash) and may be | |
14186 | followed by an optional argument parameter. Options occur first in the | |
14187 | parameter list and can be delimited from normal parameters using | |
14188 | @samp{--} (this is useful when some parameters begin with a dash). | |
14189 | @end itemize | |
14190 | ||
14191 | Pragmatics: | |
14192 | ||
14193 | @itemize @bullet | |
14194 | @item | |
14195 | We want easy access to the existing CLI syntax (for debugging). | |
14196 | ||
14197 | @item | |
14198 | We want it to be easy to spot a @sc{mi} operation. | |
14199 | @end itemize | |
14200 | ||
14201 | @node GDB/MI Output Syntax | |
14202 | @subsection @sc{gdb/mi} Output Syntax | |
14203 | ||
14204 | @cindex output syntax of @sc{gdb/mi} | |
14205 | @cindex @sc{gdb/mi}, output syntax | |
14206 | The output from @sc{gdb/mi} consists of zero or more out-of-band records | |
14207 | followed, optionally, by a single result record. This result record | |
14208 | is for the most recent command. The sequence of output records is | |
14209 | terminated by @samp{(@value{GDBP})}. | |
14210 | ||
14211 | If an input command was prefixed with a @code{@var{token}} then the | |
14212 | corresponding output for that command will also be prefixed by that same | |
14213 | @var{token}. | |
14214 | ||
14215 | @table @code | |
14216 | @item @var{output} @expansion{} | |
14217 | @code{( @var{out-of-band-record} )* [ @var{result-record} ] "(gdb)" @var{nl}} | |
14218 | ||
14219 | @item @var{result-record} @expansion{} | |
14220 | @code{ [ @var{token} ] "^" @var{result-class} ( "," @var{result} )* @var{nl}} | |
14221 | ||
14222 | @item @var{out-of-band-record} @expansion{} | |
14223 | @code{@var{async-record} | @var{stream-record}} | |
14224 | ||
14225 | @item @var{async-record} @expansion{} | |
14226 | @code{@var{exec-async-output} | @var{status-async-output} | @var{notify-async-output}} | |
14227 | ||
14228 | @item @var{exec-async-output} @expansion{} | |
14229 | @code{[ @var{token} ] "*" @var{async-output}} | |
14230 | ||
14231 | @item @var{status-async-output} @expansion{} | |
14232 | @code{[ @var{token} ] "+" @var{async-output}} | |
14233 | ||
14234 | @item @var{notify-async-output} @expansion{} | |
14235 | @code{[ @var{token} ] "=" @var{async-output}} | |
14236 | ||
14237 | @item @var{async-output} @expansion{} | |
14238 | @code{@var{async-class} ( "," @var{result} )* @var{nl}} | |
14239 | ||
14240 | @item @var{result-class} @expansion{} | |
14241 | @code{"done" | "running" | "connected" | "error" | "exit"} | |
14242 | ||
14243 | @item @var{async-class} @expansion{} | |
14244 | @code{"stopped" | @var{others}} (where @var{others} will be added | |
14245 | depending on the needs---this is still in development). | |
14246 | ||
14247 | @item @var{result} @expansion{} | |
14248 | @code{ @var{variable} "=" @var{value}} | |
14249 | ||
14250 | @item @var{variable} @expansion{} | |
14251 | @code{ @var{string} } | |
14252 | ||
14253 | @item @var{value} @expansion{} | |
14254 | @code{ @var{const} | @var{tuple} | @var{list} } | |
14255 | ||
14256 | @item @var{const} @expansion{} | |
14257 | @code{@var{c-string}} | |
14258 | ||
14259 | @item @var{tuple} @expansion{} | |
14260 | @code{ "@{@}" | "@{" @var{result} ( "," @var{result} )* "@}" } | |
14261 | ||
14262 | @item @var{list} @expansion{} | |
14263 | @code{ "[]" | "[" @var{value} ( "," @var{value} )* "]" | "[" | |
14264 | @var{result} ( "," @var{result} )* "]" } | |
14265 | ||
14266 | @item @var{stream-record} @expansion{} | |
14267 | @code{@var{console-stream-output} | @var{target-stream-output} | @var{log-stream-output}} | |
14268 | ||
14269 | @item @var{console-stream-output} @expansion{} | |
14270 | @code{"~" @var{c-string}} | |
14271 | ||
14272 | @item @var{target-stream-output} @expansion{} | |
14273 | @code{"@@" @var{c-string}} | |
14274 | ||
14275 | @item @var{log-stream-output} @expansion{} | |
14276 | @code{"&" @var{c-string}} | |
14277 | ||
14278 | @item @var{nl} @expansion{} | |
14279 | @code{CR | CR-LF} | |
14280 | ||
14281 | @item @var{token} @expansion{} | |
14282 | @emph{any sequence of digits}. | |
14283 | @end table | |
14284 | ||
14285 | @noindent | |
14286 | Notes: | |
14287 | ||
14288 | @itemize @bullet | |
14289 | @item | |
14290 | All output sequences end in a single line containing a period. | |
14291 | ||
14292 | @item | |
14293 | The @code{@var{token}} is from the corresponding request. If an execution | |
14294 | command is interrupted by the @samp{-exec-interrupt} command, the | |
14295 | @var{token} associated with the @samp{*stopped} message is the one of the | |
14296 | original execution command, not the one of the interrupt command. | |
14297 | ||
14298 | @item | |
14299 | @cindex status output in @sc{gdb/mi} | |
14300 | @var{status-async-output} contains on-going status information about the | |
14301 | progress of a slow operation. It can be discarded. All status output is | |
14302 | prefixed by @samp{+}. | |
14303 | ||
14304 | @item | |
14305 | @cindex async output in @sc{gdb/mi} | |
14306 | @var{exec-async-output} contains asynchronous state change on the target | |
14307 | (stopped, started, disappeared). All async output is prefixed by | |
14308 | @samp{*}. | |
14309 | ||
14310 | @item | |
14311 | @cindex notify output in @sc{gdb/mi} | |
14312 | @var{notify-async-output} contains supplementary information that the | |
14313 | client should handle (e.g., a new breakpoint information). All notify | |
14314 | output is prefixed by @samp{=}. | |
14315 | ||
14316 | @item | |
14317 | @cindex console output in @sc{gdb/mi} | |
14318 | @var{console-stream-output} is output that should be displayed as is in the | |
14319 | console. It is the textual response to a CLI command. All the console | |
14320 | output is prefixed by @samp{~}. | |
14321 | ||
14322 | @item | |
14323 | @cindex target output in @sc{gdb/mi} | |
14324 | @var{target-stream-output} is the output produced by the target program. | |
14325 | All the target output is prefixed by @samp{@@}. | |
14326 | ||
14327 | @item | |
14328 | @cindex log output in @sc{gdb/mi} | |
14329 | @var{log-stream-output} is output text coming from @value{GDBN}'s internals, for | |
14330 | instance messages that should be displayed as part of an error log. All | |
14331 | the log output is prefixed by @samp{&}. | |
14332 | ||
14333 | @item | |
14334 | @cindex list output in @sc{gdb/mi} | |
14335 | New @sc{gdb/mi} commands should only output @var{lists} containing | |
14336 | @var{values}. | |
14337 | ||
14338 | ||
14339 | @end itemize | |
14340 | ||
14341 | @xref{GDB/MI Stream Records, , @sc{gdb/mi} Stream Records}, for more | |
14342 | details about the various output records. | |
14343 | ||
14344 | @node GDB/MI Simple Examples | |
14345 | @subsection Simple Examples of @sc{gdb/mi} Interaction | |
14346 | @cindex @sc{gdb/mi}, simple examples | |
14347 | ||
14348 | This subsection presents several simple examples of interaction using | |
14349 | the @sc{gdb/mi} interface. In these examples, @samp{->} means that the | |
14350 | following line is passed to @sc{gdb/mi} as input, while @samp{<-} means | |
14351 | the output received from @sc{gdb/mi}. | |
14352 | ||
14353 | @subsubheading Target Stop | |
14354 | @c Ummm... There is no "-stop" command. This assumes async, no? | |
14355 | Here's an example of stopping the inferior process: | |
14356 | ||
14357 | @smallexample | |
14358 | -> -stop | |
14359 | <- (@value{GDBP}) | |
14360 | @end smallexample | |
14361 | ||
14362 | @noindent | |
14363 | and later: | |
14364 | ||
14365 | @smallexample | |
14366 | <- *stop,reason="stop",address="0x123",source="a.c:123" | |
14367 | <- (@value{GDBP}) | |
14368 | @end smallexample | |
14369 | ||
14370 | @subsubheading Simple CLI Command | |
14371 | ||
14372 | Here's an example of a simple CLI command being passed through | |
14373 | @sc{gdb/mi} and on to the CLI. | |
14374 | ||
14375 | @smallexample | |
14376 | -> print 1+2 | |
14377 | <- &"print 1+2\n" | |
14378 | <- ~"$1 = 3\n" | |
14379 | <- ^done | |
14380 | <- (@value{GDBP}) | |
14381 | @end smallexample | |
14382 | ||
14383 | @subsubheading Command With Side Effects | |
14384 | ||
14385 | @smallexample | |
14386 | -> -symbol-file xyz.exe | |
14387 | <- *breakpoint,nr="3",address="0x123",source="a.c:123" | |
14388 | <- (@value{GDBP}) | |
14389 | @end smallexample | |
14390 | ||
14391 | @subsubheading A Bad Command | |
14392 | ||
14393 | Here's what happens if you pass a non-existent command: | |
14394 | ||
14395 | @smallexample | |
14396 | -> -rubbish | |
14397 | <- ^error,msg="Undefined MI command: rubbish" | |
14398 | <- (@value{GDBP}) | |
14399 | @end smallexample | |
14400 | ||
14401 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
14402 | @node GDB/MI Compatibility with CLI | |
14403 | @section @sc{gdb/mi} Compatibility with CLI | |
14404 | ||
14405 | @cindex compatibility, @sc{gdb/mi} and CLI | |
14406 | @cindex @sc{gdb/mi}, compatibility with CLI | |
14407 | To help users familiar with @value{GDBN}'s existing CLI interface, @sc{gdb/mi} | |
14408 | accepts existing CLI commands. As specified by the syntax, such | |
14409 | commands can be directly entered into the @sc{gdb/mi} interface and @value{GDBN} will | |
14410 | respond. | |
14411 | ||
14412 | This mechanism is provided as an aid to developers of @sc{gdb/mi} | |
14413 | clients and not as a reliable interface into the CLI. Since the command | |
14414 | is being interpreteted in an environment that assumes @sc{gdb/mi} | |
14415 | behaviour, the exact output of such commands is likely to end up being | |
14416 | an un-supported hybrid of @sc{gdb/mi} and CLI output. | |
14417 | ||
14418 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
14419 | @node GDB/MI Output Records | |
14420 | @section @sc{gdb/mi} Output Records | |
14421 | ||
14422 | @menu | |
14423 | * GDB/MI Result Records:: | |
14424 | * GDB/MI Stream Records:: | |
14425 | * GDB/MI Out-of-band Records:: | |
14426 | @end menu | |
14427 | ||
14428 | @node GDB/MI Result Records | |
14429 | @subsection @sc{gdb/mi} Result Records | |
14430 | ||
14431 | @cindex result records in @sc{gdb/mi} | |
14432 | @cindex @sc{gdb/mi}, result records | |
14433 | In addition to a number of out-of-band notifications, the response to a | |
14434 | @sc{gdb/mi} command includes one of the following result indications: | |
14435 | ||
14436 | @table @code | |
14437 | @findex ^done | |
14438 | @item "^done" [ "," @var{results} ] | |
14439 | The synchronous operation was successful, @code{@var{results}} are the return | |
14440 | values. | |
14441 | ||
14442 | @item "^running" | |
14443 | @findex ^running | |
14444 | @c Is this one correct? Should it be an out-of-band notification? | |
14445 | The asynchronous operation was successfully started. The target is | |
14446 | running. | |
14447 | ||
14448 | @item "^error" "," @var{c-string} | |
14449 | @findex ^error | |
14450 | The operation failed. The @code{@var{c-string}} contains the corresponding | |
14451 | error message. | |
14452 | @end table | |
14453 | ||
14454 | @node GDB/MI Stream Records | |
14455 | @subsection @sc{gdb/mi} Stream Records | |
14456 | ||
14457 | @cindex @sc{gdb/mi}, stream records | |
14458 | @cindex stream records in @sc{gdb/mi} | |
14459 | @value{GDBN} internally maintains a number of output streams: the console, the | |
14460 | target, and the log. The output intended for each of these streams is | |
14461 | funneled through the @sc{gdb/mi} interface using @dfn{stream records}. | |
14462 | ||
14463 | Each stream record begins with a unique @dfn{prefix character} which | |
14464 | identifies its stream (@pxref{GDB/MI Output Syntax, , @sc{gdb/mi} Output | |
14465 | Syntax}). In addition to the prefix, each stream record contains a | |
14466 | @code{@var{string-output}}. This is either raw text (with an implicit new | |
14467 | line) or a quoted C string (which does not contain an implicit newline). | |
14468 | ||
14469 | @table @code | |
14470 | @item "~" @var{string-output} | |
14471 | The console output stream contains text that should be displayed in the | |
14472 | CLI console window. It contains the textual responses to CLI commands. | |
14473 | ||
14474 | @item "@@" @var{string-output} | |
14475 | The target output stream contains any textual output from the running | |
14476 | target. | |
14477 | ||
14478 | @item "&" @var{string-output} | |
14479 | The log stream contains debugging messages being produced by @value{GDBN}'s | |
14480 | internals. | |
14481 | @end table | |
14482 | ||
14483 | @node GDB/MI Out-of-band Records | |
14484 | @subsection @sc{gdb/mi} Out-of-band Records | |
14485 | ||
14486 | @cindex out-of-band records in @sc{gdb/mi} | |
14487 | @cindex @sc{gdb/mi}, out-of-band records | |
14488 | @dfn{Out-of-band} records are used to notify the @sc{gdb/mi} client of | |
14489 | additional changes that have occurred. Those changes can either be a | |
14490 | consequence of @sc{gdb/mi} (e.g., a breakpoint modified) or a result of | |
14491 | target activity (e.g., target stopped). | |
14492 | ||
14493 | The following is a preliminary list of possible out-of-band records. | |
14494 | ||
14495 | @table @code | |
14496 | @item "*" "stop" | |
14497 | @end table | |
14498 | ||
14499 | ||
14500 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
14501 | @node GDB/MI Command Description Format | |
14502 | @section @sc{gdb/mi} Command Description Format | |
14503 | ||
14504 | The remaining sections describe blocks of commands. Each block of | |
14505 | commands is laid out in a fashion similar to this section. | |
14506 | ||
14507 | Note the the line breaks shown in the examples are here only for | |
14508 | readability. They don't appear in the real output. | |
14509 | Also note that the commands with a non-available example (N.A.@:) are | |
14510 | not yet implemented. | |
14511 | ||
14512 | @subheading Motivation | |
14513 | ||
14514 | The motivation for this collection of commands. | |
14515 | ||
14516 | @subheading Introduction | |
14517 | ||
14518 | A brief introduction to this collection of commands as a whole. | |
14519 | ||
14520 | @subheading Commands | |
14521 | ||
14522 | For each command in the block, the following is described: | |
14523 | ||
14524 | @subsubheading Synopsis | |
14525 | ||
14526 | @smallexample | |
14527 | -command @var{args}@dots{} | |
14528 | @end smallexample | |
14529 | ||
14530 | @subsubheading @value{GDBN} Command | |
14531 | ||
14532 | The corresponding @value{GDBN} CLI command. | |
14533 | ||
14534 | @subsubheading Result | |
14535 | ||
14536 | @subsubheading Out-of-band | |
14537 | ||
14538 | @subsubheading Notes | |
14539 | ||
14540 | @subsubheading Example | |
14541 | ||
14542 | ||
14543 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
14544 | @node GDB/MI Breakpoint Table Commands | |
14545 | @section @sc{gdb/mi} Breakpoint table commands | |
14546 | ||
14547 | @cindex breakpoint commands for @sc{gdb/mi} | |
14548 | @cindex @sc{gdb/mi}, breakpoint commands | |
14549 | This section documents @sc{gdb/mi} commands for manipulating | |
14550 | breakpoints. | |
14551 | ||
14552 | @subheading The @code{-break-after} Command | |
14553 | @findex -break-after | |
14554 | ||
14555 | @subsubheading Synopsis | |
14556 | ||
14557 | @smallexample | |
14558 | -break-after @var{number} @var{count} | |
14559 | @end smallexample | |
14560 | ||
14561 | The breakpoint number @var{number} is not in effect until it has been | |
14562 | hit @var{count} times. To see how this is reflected in the output of | |
14563 | the @samp{-break-list} command, see the description of the | |
14564 | @samp{-break-list} command below. | |
14565 | ||
14566 | @subsubheading @value{GDBN} Command | |
14567 | ||
14568 | The corresponding @value{GDBN} command is @samp{ignore}. | |
14569 | ||
14570 | @subsubheading Example | |
14571 | ||
14572 | @smallexample | |
14573 | (@value{GDBP}) | |
14574 | -break-insert main | |
14575 | ^done,bkpt=@{number="1",addr="0x000100d0",file="hello.c",line="5"@} | |
14576 | (@value{GDBP}) | |
14577 | -break-after 1 3 | |
14578 | ~ | |
14579 | ^done | |
14580 | (@value{GDBP}) | |
14581 | -break-list | |
14582 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
14583 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14584 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14585 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14586 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14587 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14588 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14589 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
14590 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0", | |
14591 | ignore="3"@}]@} | |
14592 | (@value{GDBP}) | |
14593 | @end smallexample | |
14594 | ||
14595 | @ignore | |
14596 | @subheading The @code{-break-catch} Command | |
14597 | @findex -break-catch | |
14598 | ||
14599 | @subheading The @code{-break-commands} Command | |
14600 | @findex -break-commands | |
14601 | @end ignore | |
14602 | ||
14603 | ||
14604 | @subheading The @code{-break-condition} Command | |
14605 | @findex -break-condition | |
14606 | ||
14607 | @subsubheading Synopsis | |
14608 | ||
14609 | @smallexample | |
14610 | -break-condition @var{number} @var{expr} | |
14611 | @end smallexample | |
14612 | ||
14613 | Breakpoint @var{number} will stop the program only if the condition in | |
14614 | @var{expr} is true. The condition becomes part of the | |
14615 | @samp{-break-list} output (see the description of the @samp{-break-list} | |
14616 | command below). | |
14617 | ||
14618 | @subsubheading @value{GDBN} Command | |
14619 | ||
14620 | The corresponding @value{GDBN} command is @samp{condition}. | |
14621 | ||
14622 | @subsubheading Example | |
14623 | ||
14624 | @smallexample | |
14625 | (@value{GDBP}) | |
14626 | -break-condition 1 1 | |
14627 | ^done | |
14628 | (@value{GDBP}) | |
14629 | -break-list | |
14630 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
14631 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14632 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14633 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14634 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14635 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14636 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14637 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
14638 | addr="0x000100d0",func="main",file="hello.c",line="5",cond="1", | |
14639 | times="0",ignore="3"@}]@} | |
14640 | (@value{GDBP}) | |
14641 | @end smallexample | |
14642 | ||
14643 | @subheading The @code{-break-delete} Command | |
14644 | @findex -break-delete | |
14645 | ||
14646 | @subsubheading Synopsis | |
14647 | ||
14648 | @smallexample | |
14649 | -break-delete ( @var{breakpoint} )+ | |
14650 | @end smallexample | |
14651 | ||
14652 | Delete the breakpoint(s) whose number(s) are specified in the argument | |
14653 | list. This is obviously reflected in the breakpoint list. | |
14654 | ||
14655 | @subsubheading @value{GDBN} command | |
14656 | ||
14657 | The corresponding @value{GDBN} command is @samp{delete}. | |
14658 | ||
14659 | @subsubheading Example | |
14660 | ||
14661 | @smallexample | |
14662 | (@value{GDBP}) | |
14663 | -break-delete 1 | |
14664 | ^done | |
14665 | (@value{GDBP}) | |
14666 | -break-list | |
14667 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
14668 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14669 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14670 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14671 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14672 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14673 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14674 | body=[]@} | |
14675 | (@value{GDBP}) | |
14676 | @end smallexample | |
14677 | ||
14678 | @subheading The @code{-break-disable} Command | |
14679 | @findex -break-disable | |
14680 | ||
14681 | @subsubheading Synopsis | |
14682 | ||
14683 | @smallexample | |
14684 | -break-disable ( @var{breakpoint} )+ | |
14685 | @end smallexample | |
14686 | ||
14687 | Disable the named @var{breakpoint}(s). The field @samp{enabled} in the | |
14688 | break list is now set to @samp{n} for the named @var{breakpoint}(s). | |
14689 | ||
14690 | @subsubheading @value{GDBN} Command | |
14691 | ||
14692 | The corresponding @value{GDBN} command is @samp{disable}. | |
14693 | ||
14694 | @subsubheading Example | |
14695 | ||
14696 | @smallexample | |
14697 | (@value{GDBP}) | |
14698 | -break-disable 2 | |
14699 | ^done | |
14700 | (@value{GDBP}) | |
14701 | -break-list | |
14702 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
14703 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14704 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14705 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14706 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14707 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14708 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14709 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="n", | |
14710 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}]@} | |
14711 | (@value{GDBP}) | |
14712 | @end smallexample | |
14713 | ||
14714 | @subheading The @code{-break-enable} Command | |
14715 | @findex -break-enable | |
14716 | ||
14717 | @subsubheading Synopsis | |
14718 | ||
14719 | @smallexample | |
14720 | -break-enable ( @var{breakpoint} )+ | |
14721 | @end smallexample | |
14722 | ||
14723 | Enable (previously disabled) @var{breakpoint}(s). | |
14724 | ||
14725 | @subsubheading @value{GDBN} Command | |
14726 | ||
14727 | The corresponding @value{GDBN} command is @samp{enable}. | |
14728 | ||
14729 | @subsubheading Example | |
14730 | ||
14731 | @smallexample | |
14732 | (@value{GDBP}) | |
14733 | -break-enable 2 | |
14734 | ^done | |
14735 | (@value{GDBP}) | |
14736 | -break-list | |
14737 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
14738 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14739 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14740 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14741 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14742 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14743 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14744 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
14745 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}]@} | |
14746 | (@value{GDBP}) | |
14747 | @end smallexample | |
14748 | ||
14749 | @subheading The @code{-break-info} Command | |
14750 | @findex -break-info | |
14751 | ||
14752 | @subsubheading Synopsis | |
14753 | ||
14754 | @smallexample | |
14755 | -break-info @var{breakpoint} | |
14756 | @end smallexample | |
14757 | ||
14758 | @c REDUNDANT??? | |
14759 | Get information about a single breakpoint. | |
14760 | ||
14761 | @subsubheading @value{GDBN} command | |
14762 | ||
14763 | The corresponding @value{GDBN} command is @samp{info break @var{breakpoint}}. | |
14764 | ||
14765 | @subsubheading Example | |
14766 | N.A. | |
14767 | ||
14768 | @subheading The @code{-break-insert} Command | |
14769 | @findex -break-insert | |
14770 | ||
14771 | @subsubheading Synopsis | |
14772 | ||
14773 | @smallexample | |
14774 | -break-insert [ -t ] [ -h ] [ -r ] | |
14775 | [ -c @var{condition} ] [ -i @var{ignore-count} ] | |
14776 | [ -p @var{thread} ] [ @var{line} | @var{addr} ] | |
14777 | @end smallexample | |
14778 | ||
14779 | @noindent | |
14780 | If specified, @var{line}, can be one of: | |
14781 | ||
14782 | @itemize @bullet | |
14783 | @item function | |
14784 | @c @item +offset | |
14785 | @c @item -offset | |
14786 | @c @item linenum | |
14787 | @item filename:linenum | |
14788 | @item filename:function | |
14789 | @item *address | |
14790 | @end itemize | |
14791 | ||
14792 | The possible optional parameters of this command are: | |
14793 | ||
14794 | @table @samp | |
14795 | @item -t | |
14796 | Insert a tempoary breakpoint. | |
14797 | @item -h | |
14798 | Insert a hardware breakpoint. | |
14799 | @item -c @var{condition} | |
14800 | Make the breakpoint conditional on @var{condition}. | |
14801 | @item -i @var{ignore-count} | |
14802 | Initialize the @var{ignore-count}. | |
14803 | @item -r | |
14804 | Insert a regular breakpoint in all the functions whose names match the | |
14805 | given regular expression. Other flags are not applicable to regular | |
14806 | expresson. | |
14807 | @end table | |
14808 | ||
14809 | @subsubheading Result | |
14810 | ||
14811 | The result is in the form: | |
14812 | ||
14813 | @smallexample | |
14814 | ^done,bkptno="@var{number}",func="@var{funcname}", | |
14815 | file="@var{filename}",line="@var{lineno}" | |
14816 | @end smallexample | |
14817 | ||
14818 | @noindent | |
14819 | where @var{number} is the @value{GDBN} number for this breakpoint, @var{funcname} | |
14820 | is the name of the function where the breakpoint was inserted, | |
14821 | @var{filename} is the name of the source file which contains this | |
14822 | function, and @var{lineno} is the source line number within that file. | |
14823 | ||
14824 | Note: this format is open to change. | |
14825 | @c An out-of-band breakpoint instead of part of the result? | |
14826 | ||
14827 | @subsubheading @value{GDBN} Command | |
14828 | ||
14829 | The corresponding @value{GDBN} commands are @samp{break}, @samp{tbreak}, | |
14830 | @samp{hbreak}, @samp{thbreak}, and @samp{rbreak}. | |
14831 | ||
14832 | @subsubheading Example | |
14833 | ||
14834 | @smallexample | |
14835 | (@value{GDBP}) | |
14836 | -break-insert main | |
14837 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@} | |
14838 | (@value{GDBP}) | |
14839 | -break-insert -t foo | |
14840 | ^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c",line="11"@} | |
14841 | (@value{GDBP}) | |
14842 | -break-list | |
14843 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
14844 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14845 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14846 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14847 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14848 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14849 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14850 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
14851 | addr="0x0001072c", func="main",file="recursive2.c",line="4",times="0"@}, | |
14852 | bkpt=@{number="2",type="breakpoint",disp="del",enabled="y", | |
14853 | addr="0x00010774",func="foo",file="recursive2.c",line="11",times="0"@}]@} | |
14854 | (@value{GDBP}) | |
14855 | -break-insert -r foo.* | |
14856 | ~int foo(int, int); | |
14857 | ^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c",line="11"@} | |
14858 | (@value{GDBP}) | |
14859 | @end smallexample | |
14860 | ||
14861 | @subheading The @code{-break-list} Command | |
14862 | @findex -break-list | |
14863 | ||
14864 | @subsubheading Synopsis | |
14865 | ||
14866 | @smallexample | |
14867 | -break-list | |
14868 | @end smallexample | |
14869 | ||
14870 | Displays the list of inserted breakpoints, showing the following fields: | |
14871 | ||
14872 | @table @samp | |
14873 | @item Number | |
14874 | number of the breakpoint | |
14875 | @item Type | |
14876 | type of the breakpoint: @samp{breakpoint} or @samp{watchpoint} | |
14877 | @item Disposition | |
14878 | should the breakpoint be deleted or disabled when it is hit: @samp{keep} | |
14879 | or @samp{nokeep} | |
14880 | @item Enabled | |
14881 | is the breakpoint enabled or no: @samp{y} or @samp{n} | |
14882 | @item Address | |
14883 | memory location at which the breakpoint is set | |
14884 | @item What | |
14885 | logical location of the breakpoint, expressed by function name, file | |
14886 | name, line number | |
14887 | @item Times | |
14888 | number of times the breakpoint has been hit | |
14889 | @end table | |
14890 | ||
14891 | If there are no breakpoints or watchpoints, the @code{BreakpointTable} | |
14892 | @code{body} field is an empty list. | |
14893 | ||
14894 | @subsubheading @value{GDBN} Command | |
14895 | ||
14896 | The corresponding @value{GDBN} command is @samp{info break}. | |
14897 | ||
14898 | @subsubheading Example | |
14899 | ||
14900 | @smallexample | |
14901 | (@value{GDBP}) | |
14902 | -break-list | |
14903 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
14904 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14905 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14906 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14907 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14908 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14909 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14910 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
14911 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}, | |
14912 | bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
14913 | addr="0x00010114",func="foo",file="hello.c",line="13",times="0"@}]@} | |
14914 | (@value{GDBP}) | |
14915 | @end smallexample | |
14916 | ||
14917 | Here's an example of the result when there are no breakpoints: | |
14918 | ||
14919 | @smallexample | |
14920 | (@value{GDBP}) | |
14921 | -break-list | |
14922 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
14923 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
14924 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
14925 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
14926 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
14927 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
14928 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
14929 | body=[]@} | |
14930 | (@value{GDBP}) | |
14931 | @end smallexample | |
14932 | ||
14933 | @subheading The @code{-break-watch} Command | |
14934 | @findex -break-watch | |
14935 | ||
14936 | @subsubheading Synopsis | |
14937 | ||
14938 | @smallexample | |
14939 | -break-watch [ -a | -r ] | |
14940 | @end smallexample | |
14941 | ||
14942 | Create a watchpoint. With the @samp{-a} option it will create an | |
14943 | @dfn{access} watchpoint, i.e. a watchpoint that triggers either on a | |
14944 | read from or on a write to the memory location. With the @samp{-r} | |
14945 | option, the watchpoint created is a @dfn{read} watchpoint, i.e. it will | |
14946 | trigger only when the memory location is accessed for reading. Without | |
14947 | either of the options, the watchpoint created is a regular watchpoint, | |
14948 | i.e. it will trigger when the memory location is accessed for writing. | |
14949 | @xref{Set Watchpoints, , Setting watchpoints}. | |
14950 | ||
14951 | Note that @samp{-break-list} will report a single list of watchpoints and | |
14952 | breakpoints inserted. | |
14953 | ||
14954 | @subsubheading @value{GDBN} Command | |
14955 | ||
14956 | The corresponding @value{GDBN} commands are @samp{watch}, @samp{awatch}, and | |
14957 | @samp{rwatch}. | |
14958 | ||
14959 | @subsubheading Example | |
14960 | ||
14961 | Setting a watchpoint on a variable in the @code{main} function: | |
14962 | ||
14963 | @smallexample | |
14964 | (@value{GDBP}) | |
14965 | -break-watch x | |
14966 | ^done,wpt=@{number="2",exp="x"@} | |
14967 | (@value{GDBP}) | |
14968 | -exec-continue | |
14969 | ^running | |
14970 | ^done,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@}, | |
14971 | value=@{old="-268439212",new="55"@}, | |
14972 | frame=@{func="main",args=[],file="recursive2.c",line="5"@} | |
14973 | (@value{GDBP}) | |
14974 | @end smallexample | |
14975 | ||
14976 | Setting a watchpoint on a variable local to a function. @value{GDBN} will stop | |
14977 | the program execution twice: first for the variable changing value, then | |
14978 | for the watchpoint going out of scope. | |
14979 | ||
14980 | @smallexample | |
14981 | (@value{GDBP}) | |
14982 | -break-watch C | |
14983 | ^done,wpt=@{number="5",exp="C"@} | |
14984 | (@value{GDBP}) | |
14985 | -exec-continue | |
14986 | ^running | |
14987 | ^done,reason="watchpoint-trigger", | |
14988 | wpt=@{number="5",exp="C"@},value=@{old="-276895068",new="3"@}, | |
14989 | frame=@{func="callee4",args=[], | |
14990 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
14991 | (@value{GDBP}) | |
14992 | -exec-continue | |
14993 | ^running | |
14994 | ^done,reason="watchpoint-scope",wpnum="5", | |
14995 | frame=@{func="callee3",args=[@{name="strarg", | |
14996 | value="0x11940 \"A string argument.\""@}], | |
14997 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
14998 | (@value{GDBP}) | |
14999 | @end smallexample | |
15000 | ||
15001 | Listing breakpoints and watchpoints, at different points in the program | |
15002 | execution. Note that once the watchpoint goes out of scope, it is | |
15003 | deleted. | |
15004 | ||
15005 | @smallexample | |
15006 | (@value{GDBP}) | |
15007 | -break-watch C | |
15008 | ^done,wpt=@{number="2",exp="C"@} | |
15009 | (@value{GDBP}) | |
15010 | -break-list | |
15011 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
15012 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
15013 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
15014 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
15015 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
15016 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
15017 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
15018 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
15019 | addr="0x00010734",func="callee4", | |
15020 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}, | |
15021 | bkpt=@{number="2",type="watchpoint",disp="keep", | |
15022 | enabled="y",addr="",what="C",times="0"@}]@} | |
15023 | (@value{GDBP}) | |
15024 | -exec-continue | |
15025 | ^running | |
15026 | ^done,reason="watchpoint-trigger",wpt=@{number="2",exp="C"@}, | |
15027 | value=@{old="-276895068",new="3"@}, | |
15028 | frame=@{func="callee4",args=[], | |
15029 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
15030 | (@value{GDBP}) | |
15031 | -break-list | |
15032 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
15033 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
15034 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
15035 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
15036 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
15037 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
15038 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
15039 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
15040 | addr="0x00010734",func="callee4", | |
15041 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}, | |
15042 | bkpt=@{number="2",type="watchpoint",disp="keep", | |
15043 | enabled="y",addr="",what="C",times="-5"@}]@} | |
15044 | (@value{GDBP}) | |
15045 | -exec-continue | |
15046 | ^running | |
15047 | ^done,reason="watchpoint-scope",wpnum="2", | |
15048 | frame=@{func="callee3",args=[@{name="strarg", | |
15049 | value="0x11940 \"A string argument.\""@}], | |
15050 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
15051 | (@value{GDBP}) | |
15052 | -break-list | |
15053 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
15054 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
15055 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
15056 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
15057 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
15058 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
15059 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
15060 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
15061 | addr="0x00010734",func="callee4", | |
15062 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}]@} | |
15063 | (@value{GDBP}) | |
15064 | @end smallexample | |
15065 | ||
15066 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
15067 | @node GDB/MI Data Manipulation | |
15068 | @section @sc{gdb/mi} Data Manipulation | |
15069 | ||
15070 | @cindex data manipulation, in @sc{gdb/mi} | |
15071 | @cindex @sc{gdb/mi}, data manipulation | |
15072 | This section describes the @sc{gdb/mi} commands that manipulate data: | |
15073 | examine memory and registers, evaluate expressions, etc. | |
15074 | ||
15075 | @c REMOVED FROM THE INTERFACE. | |
15076 | @c @subheading -data-assign | |
15077 | @c Change the value of a program variable. Plenty of side effects. | |
15078 | @c @subsubheading GDB command | |
15079 | @c set variable | |
15080 | @c @subsubheading Example | |
15081 | @c N.A. | |
15082 | ||
15083 | @subheading The @code{-data-disassemble} Command | |
15084 | @findex -data-disassemble | |
15085 | ||
15086 | @subsubheading Synopsis | |
15087 | ||
15088 | @smallexample | |
15089 | -data-disassemble | |
15090 | [ -s @var{start-addr} -e @var{end-addr} ] | |
15091 | | [ -f @var{filename} -l @var{linenum} [ -n @var{lines} ] ] | |
15092 | -- @var{mode} | |
15093 | @end smallexample | |
15094 | ||
15095 | @noindent | |
15096 | Where: | |
15097 | ||
15098 | @table @samp | |
15099 | @item @var{start-addr} | |
15100 | is the beginning address (or @code{$pc}) | |
15101 | @item @var{end-addr} | |
15102 | is the end address | |
15103 | @item @var{filename} | |
15104 | is the name of the file to disassemble | |
15105 | @item @var{linenum} | |
15106 | is the line number to disassemble around | |
15107 | @item @var{lines} | |
15108 | is the the number of disassembly lines to be produced. If it is -1, | |
15109 | the whole function will be disassembled, in case no @var{end-addr} is | |
15110 | specified. If @var{end-addr} is specified as a non-zero value, and | |
15111 | @var{lines} is lower than the number of disassembly lines between | |
15112 | @var{start-addr} and @var{end-addr}, only @var{lines} lines are | |
15113 | displayed; if @var{lines} is higher than the number of lines between | |
15114 | @var{start-addr} and @var{end-addr}, only the lines up to @var{end-addr} | |
15115 | are displayed. | |
15116 | @item @var{mode} | |
15117 | is either 0 (meaning only disassembly) or 1 (meaning mixed source and | |
15118 | disassembly). | |
15119 | @end table | |
15120 | ||
15121 | @subsubheading Result | |
15122 | ||
15123 | The output for each instruction is composed of four fields: | |
15124 | ||
15125 | @itemize @bullet | |
15126 | @item Address | |
15127 | @item Func-name | |
15128 | @item Offset | |
15129 | @item Instruction | |
15130 | @end itemize | |
15131 | ||
15132 | Note that whatever included in the instruction field, is not manipulated | |
15133 | directely by @sc{gdb/mi}, i.e. it is not possible to adjust its format. | |
15134 | ||
15135 | @subsubheading @value{GDBN} Command | |
15136 | ||
15137 | There's no direct mapping from this command to the CLI. | |
15138 | ||
15139 | @subsubheading Example | |
15140 | ||
15141 | Disassemble from the current value of @code{$pc} to @code{$pc + 20}: | |
15142 | ||
15143 | @smallexample | |
15144 | (@value{GDBP}) | |
15145 | -data-disassemble -s $pc -e "$pc + 20" -- 0 | |
15146 | ^done, | |
15147 | asm_insns=[ | |
15148 | @{address="0x000107c0",func-name="main",offset="4", | |
15149 | inst="mov 2, %o0"@}, | |
15150 | @{address="0x000107c4",func-name="main",offset="8", | |
15151 | inst="sethi %hi(0x11800), %o2"@}, | |
15152 | @{address="0x000107c8",func-name="main",offset="12", | |
15153 | inst="or %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"@}, | |
15154 | @{address="0x000107cc",func-name="main",offset="16", | |
15155 | inst="sethi %hi(0x11800), %o2"@}, | |
15156 | @{address="0x000107d0",func-name="main",offset="20", | |
15157 | inst="or %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"@}] | |
15158 | (@value{GDBP}) | |
15159 | @end smallexample | |
15160 | ||
15161 | Disassemble the whole @code{main} function. Line 32 is part of | |
15162 | @code{main}. | |
15163 | ||
15164 | @smallexample | |
15165 | -data-disassemble -f basics.c -l 32 -- 0 | |
15166 | ^done,asm_insns=[ | |
15167 | @{address="0x000107bc",func-name="main",offset="0", | |
15168 | inst="save %sp, -112, %sp"@}, | |
15169 | @{address="0x000107c0",func-name="main",offset="4", | |
15170 | inst="mov 2, %o0"@}, | |
15171 | @{address="0x000107c4",func-name="main",offset="8", | |
15172 | inst="sethi %hi(0x11800), %o2"@}, | |
15173 | [@dots{}] | |
15174 | @{address="0x0001081c",func-name="main",offset="96",inst="ret "@}, | |
15175 | @{address="0x00010820",func-name="main",offset="100",inst="restore "@}] | |
15176 | (@value{GDBP}) | |
15177 | @end smallexample | |
15178 | ||
15179 | Disassemble 3 instructions from the start of @code{main}: | |
15180 | ||
15181 | @smallexample | |
15182 | (@value{GDBP}) | |
15183 | -data-disassemble -f basics.c -l 32 -n 3 -- 0 | |
15184 | ^done,asm_insns=[ | |
15185 | @{address="0x000107bc",func-name="main",offset="0", | |
15186 | inst="save %sp, -112, %sp"@}, | |
15187 | @{address="0x000107c0",func-name="main",offset="4", | |
15188 | inst="mov 2, %o0"@}, | |
15189 | @{address="0x000107c4",func-name="main",offset="8", | |
15190 | inst="sethi %hi(0x11800), %o2"@}] | |
15191 | (@value{GDBP}) | |
15192 | @end smallexample | |
15193 | ||
15194 | Disassemble 3 instructions from the start of @code{main} in mixed mode: | |
15195 | ||
15196 | @smallexample | |
15197 | (@value{GDBP}) | |
15198 | -data-disassemble -f basics.c -l 32 -n 3 -- 1 | |
15199 | ^done,asm_insns=[ | |
15200 | src_and_asm_line=@{line="31", | |
15201 | file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \ | |
15202 | testsuite/gdb.mi/basics.c",line_asm_insn=[ | |
15203 | @{address="0x000107bc",func-name="main",offset="0", | |
15204 | inst="save %sp, -112, %sp"@}]@}, | |
15205 | src_and_asm_line=@{line="32", | |
15206 | file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \ | |
15207 | testsuite/gdb.mi/basics.c",line_asm_insn=[ | |
15208 | @{address="0x000107c0",func-name="main",offset="4", | |
15209 | inst="mov 2, %o0"@}, | |
15210 | @{address="0x000107c4",func-name="main",offset="8", | |
15211 | inst="sethi %hi(0x11800), %o2"@}]@}] | |
15212 | (@value{GDBP}) | |
15213 | @end smallexample | |
15214 | ||
15215 | ||
15216 | @subheading The @code{-data-evaluate-expression} Command | |
15217 | @findex -data-evaluate-expression | |
15218 | ||
15219 | @subsubheading Synopsis | |
15220 | ||
15221 | @smallexample | |
15222 | -data-evaluate-expression @var{expr} | |
15223 | @end smallexample | |
15224 | ||
15225 | Evaluate @var{expr} as an expression. The expression could contain an | |
15226 | inferior function call. The function call will execute synchronously. | |
15227 | If the expression contains spaces, it must be enclosed in double quotes. | |
15228 | ||
15229 | @subsubheading @value{GDBN} Command | |
15230 | ||
15231 | The corresponding @value{GDBN} commands are @samp{print}, @samp{output}, and | |
15232 | @samp{call}. In @code{gdbtk} only, there's a corresponding | |
15233 | @samp{gdb_eval} command. | |
15234 | ||
15235 | @subsubheading Example | |
15236 | ||
15237 | In the following example, the numbers that precede the commands are the | |
15238 | @dfn{tokens} described in @ref{GDB/MI Command Syntax, ,@sc{gdb/mi} | |
15239 | Command Syntax}. Notice how @sc{gdb/mi} returns the same tokens in its | |
15240 | output. | |
15241 | ||
15242 | @smallexample | |
15243 | 211-data-evaluate-expression A | |
15244 | 211^done,value="1" | |
15245 | (@value{GDBP}) | |
15246 | 311-data-evaluate-expression &A | |
15247 | 311^done,value="0xefffeb7c" | |
15248 | (@value{GDBP}) | |
15249 | 411-data-evaluate-expression A+3 | |
15250 | 411^done,value="4" | |
15251 | (@value{GDBP}) | |
15252 | 511-data-evaluate-expression "A + 3" | |
15253 | 511^done,value="4" | |
15254 | (@value{GDBP}) | |
15255 | @end smallexample | |
15256 | ||
15257 | ||
15258 | @subheading The @code{-data-list-changed-registers} Command | |
15259 | @findex -data-list-changed-registers | |
15260 | ||
15261 | @subsubheading Synopsis | |
15262 | ||
15263 | @smallexample | |
15264 | -data-list-changed-registers | |
15265 | @end smallexample | |
15266 | ||
15267 | Display a list of the registers that have changed. | |
15268 | ||
15269 | @subsubheading @value{GDBN} Command | |
15270 | ||
15271 | @value{GDBN} doesn't have a direct analog for this command; @code{gdbtk} | |
15272 | has the corresponding command @samp{gdb_changed_register_list}. | |
15273 | ||
15274 | @subsubheading Example | |
15275 | ||
15276 | On a PPC MBX board: | |
15277 | ||
15278 | @smallexample | |
15279 | (@value{GDBP}) | |
15280 | -exec-continue | |
15281 | ^running | |
15282 | ||
15283 | (@value{GDBP}) | |
15284 | *stopped,reason="breakpoint-hit",bkptno="1",frame=@{func="main", | |
15285 | args=[],file="try.c",line="5"@} | |
15286 | (@value{GDBP}) | |
15287 | -data-list-changed-registers | |
15288 | ^done,changed-registers=["0","1","2","4","5","6","7","8","9", | |
15289 | "10","11","13","14","15","16","17","18","19","20","21","22","23", | |
15290 | "24","25","26","27","28","30","31","64","65","66","67","69"] | |
15291 | (@value{GDBP}) | |
15292 | @end smallexample | |
15293 | ||
15294 | ||
15295 | @subheading The @code{-data-list-register-names} Command | |
15296 | @findex -data-list-register-names | |
15297 | ||
15298 | @subsubheading Synopsis | |
15299 | ||
15300 | @smallexample | |
15301 | -data-list-register-names [ ( @var{regno} )+ ] | |
15302 | @end smallexample | |
15303 | ||
15304 | Show a list of register names for the current target. If no arguments | |
15305 | are given, it shows a list of the names of all the registers. If | |
15306 | integer numbers are given as arguments, it will print a list of the | |
15307 | names of the registers corresponding to the arguments. To ensure | |
15308 | consistency between a register name and its number, the output list may | |
15309 | include empty register names. | |
15310 | ||
15311 | @subsubheading @value{GDBN} Command | |
15312 | ||
15313 | @value{GDBN} does not have a command which corresponds to | |
15314 | @samp{-data-list-register-names}. In @code{gdbtk} there is a | |
15315 | corresponding command @samp{gdb_regnames}. | |
15316 | ||
15317 | @subsubheading Example | |
15318 | ||
15319 | For the PPC MBX board: | |
15320 | @smallexample | |
15321 | (@value{GDBP}) | |
15322 | -data-list-register-names | |
15323 | ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7", | |
15324 | "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18", | |
15325 | "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29", | |
15326 | "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9", | |
15327 | "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20", | |
15328 | "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31", | |
15329 | "", "pc","ps","cr","lr","ctr","xer"] | |
15330 | (@value{GDBP}) | |
15331 | -data-list-register-names 1 2 3 | |
15332 | ^done,register-names=["r1","r2","r3"] | |
15333 | (@value{GDBP}) | |
15334 | @end smallexample | |
15335 | ||
15336 | @subheading The @code{-data-list-register-values} Command | |
15337 | @findex -data-list-register-values | |
15338 | ||
15339 | @subsubheading Synopsis | |
15340 | ||
15341 | @smallexample | |
15342 | -data-list-register-values @var{fmt} [ ( @var{regno} )*] | |
15343 | @end smallexample | |
15344 | ||
15345 | Display the registers' contents. @var{fmt} is the format according to | |
15346 | which the registers' contents are to be returned, followed by an optional | |
15347 | list of numbers specifying the registers to display. A missing list of | |
15348 | numbers indicates that the contents of all the registers must be returned. | |
15349 | ||
15350 | Allowed formats for @var{fmt} are: | |
15351 | ||
15352 | @table @code | |
15353 | @item x | |
15354 | Hexadecimal | |
15355 | @item o | |
15356 | Octal | |
15357 | @item t | |
15358 | Binary | |
15359 | @item d | |
15360 | Decimal | |
15361 | @item r | |
15362 | Raw | |
15363 | @item N | |
15364 | Natural | |
15365 | @end table | |
15366 | ||
15367 | @subsubheading @value{GDBN} Command | |
15368 | ||
15369 | The corresponding @value{GDBN} commands are @samp{info reg}, @samp{info | |
15370 | all-reg}, and (in @code{gdbtk}) @samp{gdb_fetch_registers}. | |
15371 | ||
15372 | @subsubheading Example | |
15373 | ||
15374 | For a PPC MBX board (note: line breaks are for readability only, they | |
15375 | don't appear in the actual output): | |
15376 | ||
15377 | @smallexample | |
15378 | (@value{GDBP}) | |
15379 | -data-list-register-values r 64 65 | |
15380 | ^done,register-values=[@{number="64",value="0xfe00a300"@}, | |
15381 | @{number="65",value="0x00029002"@}] | |
15382 | (@value{GDBP}) | |
15383 | -data-list-register-values x | |
15384 | ^done,register-values=[@{number="0",value="0xfe0043c8"@}, | |
15385 | @{number="1",value="0x3fff88"@},@{number="2",value="0xfffffffe"@}, | |
15386 | @{number="3",value="0x0"@},@{number="4",value="0xa"@}, | |
15387 | @{number="5",value="0x3fff68"@},@{number="6",value="0x3fff58"@}, | |
15388 | @{number="7",value="0xfe011e98"@},@{number="8",value="0x2"@}, | |
15389 | @{number="9",value="0xfa202820"@},@{number="10",value="0xfa202808"@}, | |
15390 | @{number="11",value="0x1"@},@{number="12",value="0x0"@}, | |
15391 | @{number="13",value="0x4544"@},@{number="14",value="0xffdfffff"@}, | |
15392 | @{number="15",value="0xffffffff"@},@{number="16",value="0xfffffeff"@}, | |
15393 | @{number="17",value="0xefffffed"@},@{number="18",value="0xfffffffe"@}, | |
15394 | @{number="19",value="0xffffffff"@},@{number="20",value="0xffffffff"@}, | |
15395 | @{number="21",value="0xffffffff"@},@{number="22",value="0xfffffff7"@}, | |
15396 | @{number="23",value="0xffffffff"@},@{number="24",value="0xffffffff"@}, | |
15397 | @{number="25",value="0xffffffff"@},@{number="26",value="0xfffffffb"@}, | |
15398 | @{number="27",value="0xffffffff"@},@{number="28",value="0xf7bfffff"@}, | |
15399 | @{number="29",value="0x0"@},@{number="30",value="0xfe010000"@}, | |
15400 | @{number="31",value="0x0"@},@{number="32",value="0x0"@}, | |
15401 | @{number="33",value="0x0"@},@{number="34",value="0x0"@}, | |
15402 | @{number="35",value="0x0"@},@{number="36",value="0x0"@}, | |
15403 | @{number="37",value="0x0"@},@{number="38",value="0x0"@}, | |
15404 | @{number="39",value="0x0"@},@{number="40",value="0x0"@}, | |
15405 | @{number="41",value="0x0"@},@{number="42",value="0x0"@}, | |
15406 | @{number="43",value="0x0"@},@{number="44",value="0x0"@}, | |
15407 | @{number="45",value="0x0"@},@{number="46",value="0x0"@}, | |
15408 | @{number="47",value="0x0"@},@{number="48",value="0x0"@}, | |
15409 | @{number="49",value="0x0"@},@{number="50",value="0x0"@}, | |
15410 | @{number="51",value="0x0"@},@{number="52",value="0x0"@}, | |
15411 | @{number="53",value="0x0"@},@{number="54",value="0x0"@}, | |
15412 | @{number="55",value="0x0"@},@{number="56",value="0x0"@}, | |
15413 | @{number="57",value="0x0"@},@{number="58",value="0x0"@}, | |
15414 | @{number="59",value="0x0"@},@{number="60",value="0x0"@}, | |
15415 | @{number="61",value="0x0"@},@{number="62",value="0x0"@}, | |
15416 | @{number="63",value="0x0"@},@{number="64",value="0xfe00a300"@}, | |
15417 | @{number="65",value="0x29002"@},@{number="66",value="0x202f04b5"@}, | |
15418 | @{number="67",value="0xfe0043b0"@},@{number="68",value="0xfe00b3e4"@}, | |
15419 | @{number="69",value="0x20002b03"@}] | |
15420 | (@value{GDBP}) | |
15421 | @end smallexample | |
15422 | ||
15423 | ||
15424 | @subheading The @code{-data-read-memory} Command | |
15425 | @findex -data-read-memory | |
15426 | ||
15427 | @subsubheading Synopsis | |
15428 | ||
15429 | @smallexample | |
15430 | -data-read-memory [ -o @var{byte-offset} ] | |
15431 | @var{address} @var{word-format} @var{word-size} | |
15432 | @var{nr-rows} @var{nr-cols} [ @var{aschar} ] | |
15433 | @end smallexample | |
15434 | ||
15435 | @noindent | |
15436 | where: | |
15437 | ||
15438 | @table @samp | |
15439 | @item @var{address} | |
15440 | An expression specifying the address of the first memory word to be | |
15441 | read. Complex expressions containing embedded white space should be | |
15442 | quoted using the C convention. | |
15443 | ||
15444 | @item @var{word-format} | |
15445 | The format to be used to print the memory words. The notation is the | |
15446 | same as for @value{GDBN}'s @code{print} command (@pxref{Output Formats, | |
15447 | ,Output formats}). | |
15448 | ||
15449 | @item @var{word-size} | |
15450 | The size of each memory word in bytes. | |
15451 | ||
15452 | @item @var{nr-rows} | |
15453 | The number of rows in the output table. | |
15454 | ||
15455 | @item @var{nr-cols} | |
15456 | The number of columns in the output table. | |
15457 | ||
15458 | @item @var{aschar} | |
15459 | If present, indicates that each row should include an @sc{ascii} dump. The | |
15460 | value of @var{aschar} is used as a padding character when a byte is not a | |
15461 | member of the printable @sc{ascii} character set (printable @sc{ascii} | |
15462 | characters are those whose code is between 32 and 126, inclusively). | |
15463 | ||
15464 | @item @var{byte-offset} | |
15465 | An offset to add to the @var{address} before fetching memory. | |
15466 | @end table | |
15467 | ||
15468 | This command displays memory contents as a table of @var{nr-rows} by | |
15469 | @var{nr-cols} words, each word being @var{word-size} bytes. In total, | |
15470 | @code{@var{nr-rows} * @var{nr-cols} * @var{word-size}} bytes are read | |
15471 | (returned as @samp{total-bytes}). Should less than the requested number | |
15472 | of bytes be returned by the target, the missing words are identified | |
15473 | using @samp{N/A}. The number of bytes read from the target is returned | |
15474 | in @samp{nr-bytes} and the starting address used to read memory in | |
15475 | @samp{addr}. | |
15476 | ||
15477 | The address of the next/previous row or page is available in | |
15478 | @samp{next-row} and @samp{prev-row}, @samp{next-page} and | |
15479 | @samp{prev-page}. | |
15480 | ||
15481 | @subsubheading @value{GDBN} Command | |
15482 | ||
15483 | The corresponding @value{GDBN} command is @samp{x}. @code{gdbtk} has | |
15484 | @samp{gdb_get_mem} memory read command. | |
15485 | ||
15486 | @subsubheading Example | |
15487 | ||
15488 | Read six bytes of memory starting at @code{bytes+6} but then offset by | |
15489 | @code{-6} bytes. Format as three rows of two columns. One byte per | |
15490 | word. Display each word in hex. | |
15491 | ||
15492 | @smallexample | |
15493 | (@value{GDBP}) | |
15494 | 9-data-read-memory -o -6 -- bytes+6 x 1 3 2 | |
15495 | 9^done,addr="0x00001390",nr-bytes="6",total-bytes="6", | |
15496 | next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396", | |
15497 | prev-page="0x0000138a",memory=[ | |
15498 | @{addr="0x00001390",data=["0x00","0x01"]@}, | |
15499 | @{addr="0x00001392",data=["0x02","0x03"]@}, | |
15500 | @{addr="0x00001394",data=["0x04","0x05"]@}] | |
15501 | (@value{GDBP}) | |
15502 | @end smallexample | |
15503 | ||
15504 | Read two bytes of memory starting at address @code{shorts + 64} and | |
15505 | display as a single word formatted in decimal. | |
15506 | ||
15507 | @smallexample | |
15508 | (@value{GDBP}) | |
15509 | 5-data-read-memory shorts+64 d 2 1 1 | |
15510 | 5^done,addr="0x00001510",nr-bytes="2",total-bytes="2", | |
15511 | next-row="0x00001512",prev-row="0x0000150e", | |
15512 | next-page="0x00001512",prev-page="0x0000150e",memory=[ | |
15513 | @{addr="0x00001510",data=["128"]@}] | |
15514 | (@value{GDBP}) | |
15515 | @end smallexample | |
15516 | ||
15517 | Read thirty two bytes of memory starting at @code{bytes+16} and format | |
15518 | as eight rows of four columns. Include a string encoding with @samp{x} | |
15519 | used as the non-printable character. | |
15520 | ||
15521 | @smallexample | |
15522 | (@value{GDBP}) | |
15523 | 4-data-read-memory bytes+16 x 1 8 4 x | |
15524 | 4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32", | |
15525 | next-row="0x000013c0",prev-row="0x0000139c", | |
15526 | next-page="0x000013c0",prev-page="0x00001380",memory=[ | |
15527 | @{addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"@}, | |
15528 | @{addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"@}, | |
15529 | @{addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"@}, | |
15530 | @{addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"@}, | |
15531 | @{addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"@}, | |
15532 | @{addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"@}, | |
15533 | @{addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"@}, | |
15534 | @{addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"@}] | |
15535 | (@value{GDBP}) | |
15536 | @end smallexample | |
15537 | ||
15538 | @subheading The @code{-display-delete} Command | |
15539 | @findex -display-delete | |
15540 | ||
15541 | @subsubheading Synopsis | |
15542 | ||
15543 | @smallexample | |
15544 | -display-delete @var{number} | |
15545 | @end smallexample | |
15546 | ||
15547 | Delete the display @var{number}. | |
15548 | ||
15549 | @subsubheading @value{GDBN} Command | |
15550 | ||
15551 | The corresponding @value{GDBN} command is @samp{delete display}. | |
15552 | ||
15553 | @subsubheading Example | |
15554 | N.A. | |
15555 | ||
15556 | ||
15557 | @subheading The @code{-display-disable} Command | |
15558 | @findex -display-disable | |
15559 | ||
15560 | @subsubheading Synopsis | |
15561 | ||
15562 | @smallexample | |
15563 | -display-disable @var{number} | |
15564 | @end smallexample | |
15565 | ||
15566 | Disable display @var{number}. | |
15567 | ||
15568 | @subsubheading @value{GDBN} Command | |
15569 | ||
15570 | The corresponding @value{GDBN} command is @samp{disable display}. | |
15571 | ||
15572 | @subsubheading Example | |
15573 | N.A. | |
15574 | ||
15575 | ||
15576 | @subheading The @code{-display-enable} Command | |
15577 | @findex -display-enable | |
15578 | ||
15579 | @subsubheading Synopsis | |
15580 | ||
15581 | @smallexample | |
15582 | -display-enable @var{number} | |
15583 | @end smallexample | |
15584 | ||
15585 | Enable display @var{number}. | |
15586 | ||
15587 | @subsubheading @value{GDBN} Command | |
15588 | ||
15589 | The corresponding @value{GDBN} command is @samp{enable display}. | |
15590 | ||
15591 | @subsubheading Example | |
15592 | N.A. | |
15593 | ||
15594 | ||
15595 | @subheading The @code{-display-insert} Command | |
15596 | @findex -display-insert | |
15597 | ||
15598 | @subsubheading Synopsis | |
15599 | ||
15600 | @smallexample | |
15601 | -display-insert @var{expression} | |
15602 | @end smallexample | |
15603 | ||
15604 | Display @var{expression} every time the program stops. | |
15605 | ||
15606 | @subsubheading @value{GDBN} Command | |
15607 | ||
15608 | The corresponding @value{GDBN} command is @samp{display}. | |
15609 | ||
15610 | @subsubheading Example | |
15611 | N.A. | |
15612 | ||
15613 | ||
15614 | @subheading The @code{-display-list} Command | |
15615 | @findex -display-list | |
15616 | ||
15617 | @subsubheading Synopsis | |
15618 | ||
15619 | @smallexample | |
15620 | -display-list | |
15621 | @end smallexample | |
15622 | ||
15623 | List the displays. Do not show the current values. | |
15624 | ||
15625 | @subsubheading @value{GDBN} Command | |
15626 | ||
15627 | The corresponding @value{GDBN} command is @samp{info display}. | |
15628 | ||
15629 | @subsubheading Example | |
15630 | N.A. | |
15631 | ||
15632 | ||
15633 | @subheading The @code{-environment-cd} Command | |
15634 | @findex -environment-cd | |
15635 | ||
15636 | @subsubheading Synopsis | |
15637 | ||
15638 | @smallexample | |
15639 | -environment-cd @var{pathdir} | |
15640 | @end smallexample | |
15641 | ||
15642 | Set @value{GDBN}'s working directory. | |
15643 | ||
15644 | @subsubheading @value{GDBN} Command | |
15645 | ||
15646 | The corresponding @value{GDBN} command is @samp{cd}. | |
15647 | ||
15648 | @subsubheading Example | |
15649 | ||
15650 | @smallexample | |
15651 | (@value{GDBP}) | |
15652 | -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb | |
15653 | ^done | |
15654 | (@value{GDBP}) | |
15655 | @end smallexample | |
15656 | ||
15657 | ||
15658 | @subheading The @code{-environment-directory} Command | |
15659 | @findex -environment-directory | |
15660 | ||
15661 | @subsubheading Synopsis | |
15662 | ||
15663 | @smallexample | |
15664 | -environment-directory [ -r ] [ @var{pathdir} ]+ | |
15665 | @end smallexample | |
15666 | ||
15667 | Add directories @var{pathdir} to beginning of search path for source files. | |
15668 | If the @samp{-r} option is used, the search path is reset to the default | |
15669 | search path. If directories @var{pathdir} are supplied in addition to the | |
15670 | @samp{-r} option, the search path is first reset and then addition | |
15671 | occurs as normal. | |
15672 | Multiple directories may be specified, separated by blanks. Specifying | |
15673 | multiple directories in a single command | |
15674 | results in the directories added to the beginning of the | |
15675 | search path in the same order they were presented in the command. | |
15676 | If blanks are needed as | |
15677 | part of a directory name, double-quotes should be used around | |
15678 | the name. In the command output, the path will show up separated | |
15679 | by the system directory-separator character. The directory-seperator | |
15680 | character must not be used | |
15681 | in any directory name. | |
15682 | If no directories are specified, the current search path is displayed. | |
15683 | ||
15684 | @subsubheading @value{GDBN} Command | |
15685 | ||
15686 | The corresponding @value{GDBN} command is @samp{dir}. | |
15687 | ||
15688 | @subsubheading Example | |
15689 | ||
15690 | @smallexample | |
15691 | (@value{GDBP}) | |
15692 | -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb | |
15693 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
15694 | (@value{GDBP}) | |
15695 | -environment-directory "" | |
15696 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
15697 | (@value{GDBP}) | |
15698 | -environment-directory -r /home/jjohnstn/src/gdb /usr/src | |
15699 | ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd" | |
15700 | (@value{GDBP}) | |
15701 | -environment-directory -r | |
15702 | ^done,source-path="$cdir:$cwd" | |
15703 | (@value{GDBP}) | |
15704 | @end smallexample | |
15705 | ||
15706 | ||
15707 | @subheading The @code{-environment-path} Command | |
15708 | @findex -environment-path | |
15709 | ||
15710 | @subsubheading Synopsis | |
15711 | ||
15712 | @smallexample | |
15713 | -environment-path [ -r ] [ @var{pathdir} ]+ | |
15714 | @end smallexample | |
15715 | ||
15716 | Add directories @var{pathdir} to beginning of search path for object files. | |
15717 | If the @samp{-r} option is used, the search path is reset to the original | |
15718 | search path that existed at gdb start-up. If directories @var{pathdir} are | |
15719 | supplied in addition to the | |
15720 | @samp{-r} option, the search path is first reset and then addition | |
15721 | occurs as normal. | |
15722 | Multiple directories may be specified, separated by blanks. Specifying | |
15723 | multiple directories in a single command | |
15724 | results in the directories added to the beginning of the | |
15725 | search path in the same order they were presented in the command. | |
15726 | If blanks are needed as | |
15727 | part of a directory name, double-quotes should be used around | |
15728 | the name. In the command output, the path will show up separated | |
15729 | by the system directory-separator character. The directory-seperator | |
15730 | character must not be used | |
15731 | in any directory name. | |
15732 | If no directories are specified, the current path is displayed. | |
15733 | ||
15734 | ||
15735 | @subsubheading @value{GDBN} Command | |
15736 | ||
15737 | The corresponding @value{GDBN} command is @samp{path}. | |
15738 | ||
15739 | @subsubheading Example | |
15740 | ||
15741 | @smallexample | |
15742 | (@value{GDBP}) | |
15743 | -environment-path | |
15744 | ^done,path="/usr/bin" | |
15745 | (@value{GDBP}) | |
15746 | -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin | |
15747 | ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin" | |
15748 | (@value{GDBP}) | |
15749 | -environment-path -r /usr/local/bin | |
15750 | ^done,path="/usr/local/bin:/usr/bin" | |
15751 | (@value{GDBP}) | |
15752 | @end smallexample | |
15753 | ||
15754 | ||
15755 | @subheading The @code{-environment-pwd} Command | |
15756 | @findex -environment-pwd | |
15757 | ||
15758 | @subsubheading Synopsis | |
15759 | ||
15760 | @smallexample | |
15761 | -environment-pwd | |
15762 | @end smallexample | |
15763 | ||
15764 | Show the current working directory. | |
15765 | ||
15766 | @subsubheading @value{GDBN} command | |
15767 | ||
15768 | The corresponding @value{GDBN} command is @samp{pwd}. | |
15769 | ||
15770 | @subsubheading Example | |
15771 | ||
15772 | @smallexample | |
15773 | (@value{GDBP}) | |
15774 | -environment-pwd | |
15775 | ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb" | |
15776 | (@value{GDBP}) | |
15777 | @end smallexample | |
15778 | ||
15779 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
15780 | @node GDB/MI Program Control | |
15781 | @section @sc{gdb/mi} Program control | |
15782 | ||
15783 | @subsubheading Program termination | |
15784 | ||
15785 | As a result of execution, the inferior program can run to completion, if | |
15786 | it doesn't encounter any breakpoints. In this case the output will | |
15787 | include an exit code, if the program has exited exceptionally. | |
15788 | ||
15789 | @subsubheading Examples | |
15790 | ||
15791 | @noindent | |
15792 | Program exited normally: | |
15793 | ||
15794 | @smallexample | |
15795 | (@value{GDBP}) | |
15796 | -exec-run | |
15797 | ^running | |
15798 | (@value{GDBP}) | |
15799 | x = 55 | |
15800 | *stopped,reason="exited-normally" | |
15801 | (@value{GDBP}) | |
15802 | @end smallexample | |
15803 | ||
15804 | @noindent | |
15805 | Program exited exceptionally: | |
15806 | ||
15807 | @smallexample | |
15808 | (@value{GDBP}) | |
15809 | -exec-run | |
15810 | ^running | |
15811 | (@value{GDBP}) | |
15812 | x = 55 | |
15813 | *stopped,reason="exited",exit-code="01" | |
15814 | (@value{GDBP}) | |
15815 | @end smallexample | |
15816 | ||
15817 | Another way the program can terminate is if it receives a signal such as | |
15818 | @code{SIGINT}. In this case, @sc{gdb/mi} displays this: | |
15819 | ||
15820 | @smallexample | |
15821 | (@value{GDBP}) | |
15822 | *stopped,reason="exited-signalled",signal-name="SIGINT", | |
15823 | signal-meaning="Interrupt" | |
15824 | @end smallexample | |
15825 | ||
15826 | ||
15827 | @subheading The @code{-exec-abort} Command | |
15828 | @findex -exec-abort | |
15829 | ||
15830 | @subsubheading Synopsis | |
15831 | ||
15832 | @smallexample | |
15833 | -exec-abort | |
15834 | @end smallexample | |
15835 | ||
15836 | Kill the inferior running program. | |
15837 | ||
15838 | @subsubheading @value{GDBN} Command | |
15839 | ||
15840 | The corresponding @value{GDBN} command is @samp{kill}. | |
15841 | ||
15842 | @subsubheading Example | |
15843 | N.A. | |
15844 | ||
15845 | ||
15846 | @subheading The @code{-exec-arguments} Command | |
15847 | @findex -exec-arguments | |
15848 | ||
15849 | @subsubheading Synopsis | |
15850 | ||
15851 | @smallexample | |
15852 | -exec-arguments @var{args} | |
15853 | @end smallexample | |
15854 | ||
15855 | Set the inferior program arguments, to be used in the next | |
15856 | @samp{-exec-run}. | |
15857 | ||
15858 | @subsubheading @value{GDBN} Command | |
15859 | ||
15860 | The corresponding @value{GDBN} command is @samp{set args}. | |
15861 | ||
15862 | @subsubheading Example | |
15863 | ||
15864 | @c FIXME! | |
15865 | Don't have one around. | |
15866 | ||
15867 | ||
15868 | @subheading The @code{-exec-continue} Command | |
15869 | @findex -exec-continue | |
15870 | ||
15871 | @subsubheading Synopsis | |
15872 | ||
15873 | @smallexample | |
15874 | -exec-continue | |
15875 | @end smallexample | |
15876 | ||
15877 | Asynchronous command. Resumes the execution of the inferior program | |
15878 | until a breakpoint is encountered, or until the inferior exits. | |
15879 | ||
15880 | @subsubheading @value{GDBN} Command | |
15881 | ||
15882 | The corresponding @value{GDBN} corresponding is @samp{continue}. | |
15883 | ||
15884 | @subsubheading Example | |
15885 | ||
15886 | @smallexample | |
15887 | -exec-continue | |
15888 | ^running | |
15889 | (@value{GDBP}) | |
15890 | @@Hello world | |
15891 | *stopped,reason="breakpoint-hit",bkptno="2",frame=@{func="foo",args=[], | |
15892 | file="hello.c",line="13"@} | |
15893 | (@value{GDBP}) | |
15894 | @end smallexample | |
15895 | ||
15896 | ||
15897 | @subheading The @code{-exec-finish} Command | |
15898 | @findex -exec-finish | |
15899 | ||
15900 | @subsubheading Synopsis | |
15901 | ||
15902 | @smallexample | |
15903 | -exec-finish | |
15904 | @end smallexample | |
15905 | ||
15906 | Asynchronous command. Resumes the execution of the inferior program | |
15907 | until the current function is exited. Displays the results returned by | |
15908 | the function. | |
15909 | ||
15910 | @subsubheading @value{GDBN} Command | |
15911 | ||
15912 | The corresponding @value{GDBN} command is @samp{finish}. | |
15913 | ||
15914 | @subsubheading Example | |
15915 | ||
15916 | Function returning @code{void}. | |
15917 | ||
15918 | @smallexample | |
15919 | -exec-finish | |
15920 | ^running | |
15921 | (@value{GDBP}) | |
15922 | @@hello from foo | |
15923 | *stopped,reason="function-finished",frame=@{func="main",args=[], | |
15924 | file="hello.c",line="7"@} | |
15925 | (@value{GDBP}) | |
15926 | @end smallexample | |
15927 | ||
15928 | Function returning other than @code{void}. The name of the internal | |
15929 | @value{GDBN} variable storing the result is printed, together with the | |
15930 | value itself. | |
15931 | ||
15932 | @smallexample | |
15933 | -exec-finish | |
15934 | ^running | |
15935 | (@value{GDBP}) | |
15936 | *stopped,reason="function-finished",frame=@{addr="0x000107b0",func="foo", | |
15937 | args=[@{name="a",value="1"],@{name="b",value="9"@}@}, | |
15938 | file="recursive2.c",line="14"@}, | |
15939 | gdb-result-var="$1",return-value="0" | |
15940 | (@value{GDBP}) | |
15941 | @end smallexample | |
15942 | ||
15943 | ||
15944 | @subheading The @code{-exec-interrupt} Command | |
15945 | @findex -exec-interrupt | |
15946 | ||
15947 | @subsubheading Synopsis | |
15948 | ||
15949 | @smallexample | |
15950 | -exec-interrupt | |
15951 | @end smallexample | |
15952 | ||
15953 | Asynchronous command. Interrupts the background execution of the target. | |
15954 | Note how the token associated with the stop message is the one for the | |
15955 | execution command that has been interrupted. The token for the interrupt | |
15956 | itself only appears in the @samp{^done} output. If the user is trying to | |
15957 | interrupt a non-running program, an error message will be printed. | |
15958 | ||
15959 | @subsubheading @value{GDBN} Command | |
15960 | ||
15961 | The corresponding @value{GDBN} command is @samp{interrupt}. | |
15962 | ||
15963 | @subsubheading Example | |
15964 | ||
15965 | @smallexample | |
15966 | (@value{GDBP}) | |
15967 | 111-exec-continue | |
15968 | 111^running | |
15969 | ||
15970 | (@value{GDBP}) | |
15971 | 222-exec-interrupt | |
15972 | 222^done | |
15973 | (@value{GDBP}) | |
15974 | 111*stopped,signal-name="SIGINT",signal-meaning="Interrupt", | |
15975 | frame=@{addr="0x00010140",func="foo",args=[],file="try.c",line="13"@} | |
15976 | (@value{GDBP}) | |
15977 | ||
15978 | (@value{GDBP}) | |
15979 | -exec-interrupt | |
15980 | ^error,msg="mi_cmd_exec_interrupt: Inferior not executing." | |
15981 | (@value{GDBP}) | |
15982 | @end smallexample | |
15983 | ||
15984 | ||
15985 | @subheading The @code{-exec-next} Command | |
15986 | @findex -exec-next | |
15987 | ||
15988 | @subsubheading Synopsis | |
15989 | ||
15990 | @smallexample | |
15991 | -exec-next | |
15992 | @end smallexample | |
15993 | ||
15994 | Asynchronous command. Resumes execution of the inferior program, stopping | |
15995 | when the beginning of the next source line is reached. | |
15996 | ||
15997 | @subsubheading @value{GDBN} Command | |
15998 | ||
15999 | The corresponding @value{GDBN} command is @samp{next}. | |
16000 | ||
16001 | @subsubheading Example | |
16002 | ||
16003 | @smallexample | |
16004 | -exec-next | |
16005 | ^running | |
16006 | (@value{GDBP}) | |
16007 | *stopped,reason="end-stepping-range",line="8",file="hello.c" | |
16008 | (@value{GDBP}) | |
16009 | @end smallexample | |
16010 | ||
16011 | ||
16012 | @subheading The @code{-exec-next-instruction} Command | |
16013 | @findex -exec-next-instruction | |
16014 | ||
16015 | @subsubheading Synopsis | |
16016 | ||
16017 | @smallexample | |
16018 | -exec-next-instruction | |
16019 | @end smallexample | |
16020 | ||
16021 | Asynchronous command. Executes one machine instruction. If the | |
16022 | instruction is a function call continues until the function returns. If | |
16023 | the program stops at an instruction in the middle of a source line, the | |
16024 | address will be printed as well. | |
16025 | ||
16026 | @subsubheading @value{GDBN} Command | |
16027 | ||
16028 | The corresponding @value{GDBN} command is @samp{nexti}. | |
16029 | ||
16030 | @subsubheading Example | |
16031 | ||
16032 | @smallexample | |
16033 | (@value{GDBP}) | |
16034 | -exec-next-instruction | |
16035 | ^running | |
16036 | ||
16037 | (@value{GDBP}) | |
16038 | *stopped,reason="end-stepping-range", | |
16039 | addr="0x000100d4",line="5",file="hello.c" | |
16040 | (@value{GDBP}) | |
16041 | @end smallexample | |
16042 | ||
16043 | ||
16044 | @subheading The @code{-exec-return} Command | |
16045 | @findex -exec-return | |
16046 | ||
16047 | @subsubheading Synopsis | |
16048 | ||
16049 | @smallexample | |
16050 | -exec-return | |
16051 | @end smallexample | |
16052 | ||
16053 | Makes current function return immediately. Doesn't execute the inferior. | |
16054 | Displays the new current frame. | |
16055 | ||
16056 | @subsubheading @value{GDBN} Command | |
16057 | ||
16058 | The corresponding @value{GDBN} command is @samp{return}. | |
16059 | ||
16060 | @subsubheading Example | |
16061 | ||
16062 | @smallexample | |
16063 | (@value{GDBP}) | |
16064 | 200-break-insert callee4 | |
16065 | 200^done,bkpt=@{number="1",addr="0x00010734", | |
16066 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
16067 | (@value{GDBP}) | |
16068 | 000-exec-run | |
16069 | 000^running | |
16070 | (@value{GDBP}) | |
16071 | 000*stopped,reason="breakpoint-hit",bkptno="1", | |
16072 | frame=@{func="callee4",args=[], | |
16073 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
16074 | (@value{GDBP}) | |
16075 | 205-break-delete | |
16076 | 205^done | |
16077 | (@value{GDBP}) | |
16078 | 111-exec-return | |
16079 | 111^done,frame=@{level="0",func="callee3", | |
16080 | args=[@{name="strarg", | |
16081 | value="0x11940 \"A string argument.\""@}], | |
16082 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
16083 | (@value{GDBP}) | |
16084 | @end smallexample | |
16085 | ||
16086 | ||
16087 | @subheading The @code{-exec-run} Command | |
16088 | @findex -exec-run | |
16089 | ||
16090 | @subsubheading Synopsis | |
16091 | ||
16092 | @smallexample | |
16093 | -exec-run | |
16094 | @end smallexample | |
16095 | ||
16096 | Asynchronous command. Starts execution of the inferior from the | |
16097 | beginning. The inferior executes until either a breakpoint is | |
16098 | encountered or the program exits. | |
16099 | ||
16100 | @subsubheading @value{GDBN} Command | |
16101 | ||
16102 | The corresponding @value{GDBN} command is @samp{run}. | |
16103 | ||
16104 | @subsubheading Example | |
16105 | ||
16106 | @smallexample | |
16107 | (@value{GDBP}) | |
16108 | -break-insert main | |
16109 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@} | |
16110 | (@value{GDBP}) | |
16111 | -exec-run | |
16112 | ^running | |
16113 | (@value{GDBP}) | |
16114 | *stopped,reason="breakpoint-hit",bkptno="1", | |
16115 | frame=@{func="main",args=[],file="recursive2.c",line="4"@} | |
16116 | (@value{GDBP}) | |
16117 | @end smallexample | |
16118 | ||
16119 | ||
16120 | @subheading The @code{-exec-show-arguments} Command | |
16121 | @findex -exec-show-arguments | |
16122 | ||
16123 | @subsubheading Synopsis | |
16124 | ||
16125 | @smallexample | |
16126 | -exec-show-arguments | |
16127 | @end smallexample | |
16128 | ||
16129 | Print the arguments of the program. | |
16130 | ||
16131 | @subsubheading @value{GDBN} Command | |
16132 | ||
16133 | The corresponding @value{GDBN} command is @samp{show args}. | |
16134 | ||
16135 | @subsubheading Example | |
16136 | N.A. | |
16137 | ||
16138 | @c @subheading -exec-signal | |
16139 | ||
16140 | @subheading The @code{-exec-step} Command | |
16141 | @findex -exec-step | |
16142 | ||
16143 | @subsubheading Synopsis | |
16144 | ||
16145 | @smallexample | |
16146 | -exec-step | |
16147 | @end smallexample | |
16148 | ||
16149 | Asynchronous command. Resumes execution of the inferior program, stopping | |
16150 | when the beginning of the next source line is reached, if the next | |
16151 | source line is not a function call. If it is, stop at the first | |
16152 | instruction of the called function. | |
16153 | ||
16154 | @subsubheading @value{GDBN} Command | |
16155 | ||
16156 | The corresponding @value{GDBN} command is @samp{step}. | |
16157 | ||
16158 | @subsubheading Example | |
16159 | ||
16160 | Stepping into a function: | |
16161 | ||
16162 | @smallexample | |
16163 | -exec-step | |
16164 | ^running | |
16165 | (@value{GDBP}) | |
16166 | *stopped,reason="end-stepping-range", | |
16167 | frame=@{func="foo",args=[@{name="a",value="10"@}, | |
16168 | @{name="b",value="0"@}],file="recursive2.c",line="11"@} | |
16169 | (@value{GDBP}) | |
16170 | @end smallexample | |
16171 | ||
16172 | Regular stepping: | |
16173 | ||
16174 | @smallexample | |
16175 | -exec-step | |
16176 | ^running | |
16177 | (@value{GDBP}) | |
16178 | *stopped,reason="end-stepping-range",line="14",file="recursive2.c" | |
16179 | (@value{GDBP}) | |
16180 | @end smallexample | |
16181 | ||
16182 | ||
16183 | @subheading The @code{-exec-step-instruction} Command | |
16184 | @findex -exec-step-instruction | |
16185 | ||
16186 | @subsubheading Synopsis | |
16187 | ||
16188 | @smallexample | |
16189 | -exec-step-instruction | |
16190 | @end smallexample | |
16191 | ||
16192 | Asynchronous command. Resumes the inferior which executes one machine | |
16193 | instruction. The output, once @value{GDBN} has stopped, will vary depending on | |
16194 | whether we have stopped in the middle of a source line or not. In the | |
16195 | former case, the address at which the program stopped will be printed as | |
16196 | well. | |
16197 | ||
16198 | @subsubheading @value{GDBN} Command | |
16199 | ||
16200 | The corresponding @value{GDBN} command is @samp{stepi}. | |
16201 | ||
16202 | @subsubheading Example | |
16203 | ||
16204 | @smallexample | |
16205 | (@value{GDBP}) | |
16206 | -exec-step-instruction | |
16207 | ^running | |
16208 | ||
16209 | (@value{GDBP}) | |
16210 | *stopped,reason="end-stepping-range", | |
16211 | frame=@{func="foo",args=[],file="try.c",line="10"@} | |
16212 | (@value{GDBP}) | |
16213 | -exec-step-instruction | |
16214 | ^running | |
16215 | ||
16216 | (@value{GDBP}) | |
16217 | *stopped,reason="end-stepping-range", | |
16218 | frame=@{addr="0x000100f4",func="foo",args=[],file="try.c",line="10"@} | |
16219 | (@value{GDBP}) | |
16220 | @end smallexample | |
16221 | ||
16222 | ||
16223 | @subheading The @code{-exec-until} Command | |
16224 | @findex -exec-until | |
16225 | ||
16226 | @subsubheading Synopsis | |
16227 | ||
16228 | @smallexample | |
16229 | -exec-until [ @var{location} ] | |
16230 | @end smallexample | |
16231 | ||
16232 | Asynchronous command. Executes the inferior until the @var{location} | |
16233 | specified in the argument is reached. If there is no argument, the inferior | |
16234 | executes until a source line greater than the current one is reached. | |
16235 | The reason for stopping in this case will be @samp{location-reached}. | |
16236 | ||
16237 | @subsubheading @value{GDBN} Command | |
16238 | ||
16239 | The corresponding @value{GDBN} command is @samp{until}. | |
16240 | ||
16241 | @subsubheading Example | |
16242 | ||
16243 | @smallexample | |
16244 | (@value{GDBP}) | |
16245 | -exec-until recursive2.c:6 | |
16246 | ^running | |
16247 | (@value{GDBP}) | |
16248 | x = 55 | |
16249 | *stopped,reason="location-reached",frame=@{func="main",args=[], | |
16250 | file="recursive2.c",line="6"@} | |
16251 | (@value{GDBP}) | |
16252 | @end smallexample | |
16253 | ||
16254 | @ignore | |
16255 | @subheading -file-clear | |
16256 | Is this going away???? | |
16257 | @end ignore | |
16258 | ||
16259 | ||
16260 | @subheading The @code{-file-exec-and-symbols} Command | |
16261 | @findex -file-exec-and-symbols | |
16262 | ||
16263 | @subsubheading Synopsis | |
16264 | ||
16265 | @smallexample | |
16266 | -file-exec-and-symbols @var{file} | |
16267 | @end smallexample | |
16268 | ||
16269 | Specify the executable file to be debugged. This file is the one from | |
16270 | which the symbol table is also read. If no file is specified, the | |
16271 | command clears the executable and symbol information. If breakpoints | |
16272 | are set when using this command with no arguments, @value{GDBN} will produce | |
16273 | error messages. Otherwise, no output is produced, except a completion | |
16274 | notification. | |
16275 | ||
16276 | @subsubheading @value{GDBN} Command | |
16277 | ||
16278 | The corresponding @value{GDBN} command is @samp{file}. | |
16279 | ||
16280 | @subsubheading Example | |
16281 | ||
16282 | @smallexample | |
16283 | (@value{GDBP}) | |
16284 | -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx | |
16285 | ^done | |
16286 | (@value{GDBP}) | |
16287 | @end smallexample | |
16288 | ||
16289 | ||
16290 | @subheading The @code{-file-exec-file} Command | |
16291 | @findex -file-exec-file | |
16292 | ||
16293 | @subsubheading Synopsis | |
16294 | ||
16295 | @smallexample | |
16296 | -file-exec-file @var{file} | |
16297 | @end smallexample | |
16298 | ||
16299 | Specify the executable file to be debugged. Unlike | |
16300 | @samp{-file-exec-and-symbols}, the symbol table is @emph{not} read | |
16301 | from this file. If used without argument, @value{GDBN} clears the information | |
16302 | about the executable file. No output is produced, except a completion | |
16303 | notification. | |
16304 | ||
16305 | @subsubheading @value{GDBN} Command | |
16306 | ||
16307 | The corresponding @value{GDBN} command is @samp{exec-file}. | |
16308 | ||
16309 | @subsubheading Example | |
16310 | ||
16311 | @smallexample | |
16312 | (@value{GDBP}) | |
16313 | -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx | |
16314 | ^done | |
16315 | (@value{GDBP}) | |
16316 | @end smallexample | |
16317 | ||
16318 | ||
16319 | @subheading The @code{-file-list-exec-sections} Command | |
16320 | @findex -file-list-exec-sections | |
16321 | ||
16322 | @subsubheading Synopsis | |
16323 | ||
16324 | @smallexample | |
16325 | -file-list-exec-sections | |
16326 | @end smallexample | |
16327 | ||
16328 | List the sections of the current executable file. | |
16329 | ||
16330 | @subsubheading @value{GDBN} Command | |
16331 | ||
16332 | The @value{GDBN} command @samp{info file} shows, among the rest, the same | |
16333 | information as this command. @code{gdbtk} has a corresponding command | |
16334 | @samp{gdb_load_info}. | |
16335 | ||
16336 | @subsubheading Example | |
16337 | N.A. | |
16338 | ||
16339 | ||
16340 | @subheading The @code{-file-list-exec-source-files} Command | |
16341 | @findex -file-list-exec-source-files | |
16342 | ||
16343 | @subsubheading Synopsis | |
16344 | ||
16345 | @smallexample | |
16346 | -file-list-exec-source-files | |
16347 | @end smallexample | |
16348 | ||
16349 | List the source files for the current executable. | |
16350 | ||
16351 | @subsubheading @value{GDBN} Command | |
16352 | ||
16353 | There's no @value{GDBN} command which directly corresponds to this one. | |
16354 | @code{gdbtk} has an analogous command @samp{gdb_listfiles}. | |
16355 | ||
16356 | @subsubheading Example | |
16357 | N.A. | |
16358 | ||
16359 | ||
16360 | @subheading The @code{-file-list-shared-libraries} Command | |
16361 | @findex -file-list-shared-libraries | |
16362 | ||
16363 | @subsubheading Synopsis | |
16364 | ||
16365 | @smallexample | |
16366 | -file-list-shared-libraries | |
16367 | @end smallexample | |
16368 | ||
16369 | List the shared libraries in the program. | |
16370 | ||
16371 | @subsubheading @value{GDBN} Command | |
16372 | ||
16373 | The corresponding @value{GDBN} command is @samp{info shared}. | |
16374 | ||
16375 | @subsubheading Example | |
16376 | N.A. | |
16377 | ||
16378 | ||
16379 | @subheading The @code{-file-list-symbol-files} Command | |
16380 | @findex -file-list-symbol-files | |
16381 | ||
16382 | @subsubheading Synopsis | |
16383 | ||
16384 | @smallexample | |
16385 | -file-list-symbol-files | |
16386 | @end smallexample | |
16387 | ||
16388 | List symbol files. | |
16389 | ||
16390 | @subsubheading @value{GDBN} Command | |
16391 | ||
16392 | The corresponding @value{GDBN} command is @samp{info file} (part of it). | |
16393 | ||
16394 | @subsubheading Example | |
16395 | N.A. | |
16396 | ||
16397 | ||
16398 | @subheading The @code{-file-symbol-file} Command | |
16399 | @findex -file-symbol-file | |
16400 | ||
16401 | @subsubheading Synopsis | |
16402 | ||
16403 | @smallexample | |
16404 | -file-symbol-file @var{file} | |
16405 | @end smallexample | |
16406 | ||
16407 | Read symbol table info from the specified @var{file} argument. When | |
16408 | used without arguments, clears @value{GDBN}'s symbol table info. No output is | |
16409 | produced, except for a completion notification. | |
16410 | ||
16411 | @subsubheading @value{GDBN} Command | |
16412 | ||
16413 | The corresponding @value{GDBN} command is @samp{symbol-file}. | |
16414 | ||
16415 | @subsubheading Example | |
16416 | ||
16417 | @smallexample | |
16418 | (@value{GDBP}) | |
16419 | -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx | |
16420 | ^done | |
16421 | (@value{GDBP}) | |
16422 | @end smallexample | |
16423 | ||
16424 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
16425 | @node GDB/MI Miscellaneous Commands | |
16426 | @section Miscellaneous @value{GDBN} commands in @sc{gdb/mi} | |
16427 | ||
16428 | @c @subheading -gdb-complete | |
16429 | ||
16430 | @subheading The @code{-gdb-exit} Command | |
16431 | @findex -gdb-exit | |
16432 | ||
16433 | @subsubheading Synopsis | |
16434 | ||
16435 | @smallexample | |
16436 | -gdb-exit | |
16437 | @end smallexample | |
16438 | ||
16439 | Exit @value{GDBN} immediately. | |
16440 | ||
16441 | @subsubheading @value{GDBN} Command | |
16442 | ||
16443 | Approximately corresponds to @samp{quit}. | |
16444 | ||
16445 | @subsubheading Example | |
16446 | ||
16447 | @smallexample | |
16448 | (@value{GDBP}) | |
16449 | -gdb-exit | |
16450 | @end smallexample | |
16451 | ||
16452 | @subheading The @code{-gdb-set} Command | |
16453 | @findex -gdb-set | |
16454 | ||
16455 | @subsubheading Synopsis | |
16456 | ||
16457 | @smallexample | |
16458 | -gdb-set | |
16459 | @end smallexample | |
16460 | ||
16461 | Set an internal @value{GDBN} variable. | |
16462 | @c IS THIS A DOLLAR VARIABLE? OR SOMETHING LIKE ANNOTATE ????? | |
16463 | ||
16464 | @subsubheading @value{GDBN} Command | |
16465 | ||
16466 | The corresponding @value{GDBN} command is @samp{set}. | |
16467 | ||
16468 | @subsubheading Example | |
16469 | ||
16470 | @smallexample | |
16471 | (@value{GDBP}) | |
16472 | -gdb-set $foo=3 | |
16473 | ^done | |
16474 | (@value{GDBP}) | |
16475 | @end smallexample | |
16476 | ||
16477 | ||
16478 | @subheading The @code{-gdb-show} Command | |
16479 | @findex -gdb-show | |
16480 | ||
16481 | @subsubheading Synopsis | |
16482 | ||
16483 | @smallexample | |
16484 | -gdb-show | |
16485 | @end smallexample | |
16486 | ||
16487 | Show the current value of a @value{GDBN} variable. | |
16488 | ||
16489 | @subsubheading @value{GDBN} command | |
16490 | ||
16491 | The corresponding @value{GDBN} command is @samp{show}. | |
16492 | ||
16493 | @subsubheading Example | |
16494 | ||
16495 | @smallexample | |
16496 | (@value{GDBP}) | |
16497 | -gdb-show annotate | |
16498 | ^done,value="0" | |
16499 | (@value{GDBP}) | |
16500 | @end smallexample | |
16501 | ||
16502 | @c @subheading -gdb-source | |
16503 | ||
16504 | ||
16505 | @subheading The @code{-gdb-version} Command | |
16506 | @findex -gdb-version | |
16507 | ||
16508 | @subsubheading Synopsis | |
16509 | ||
16510 | @smallexample | |
16511 | -gdb-version | |
16512 | @end smallexample | |
16513 | ||
16514 | Show version information for @value{GDBN}. Used mostly in testing. | |
16515 | ||
16516 | @subsubheading @value{GDBN} Command | |
16517 | ||
16518 | There's no equivalent @value{GDBN} command. @value{GDBN} by default shows this | |
16519 | information when you start an interactive session. | |
16520 | ||
16521 | @subsubheading Example | |
16522 | ||
16523 | @c This example modifies the actual output from GDB to avoid overfull | |
16524 | @c box in TeX. | |
16525 | @smallexample | |
16526 | (@value{GDBP}) | |
16527 | -gdb-version | |
16528 | ~GNU gdb 5.2.1 | |
16529 | ~Copyright 2000 Free Software Foundation, Inc. | |
16530 | ~GDB is free software, covered by the GNU General Public License, and | |
16531 | ~you are welcome to change it and/or distribute copies of it under | |
16532 | ~ certain conditions. | |
16533 | ~Type "show copying" to see the conditions. | |
16534 | ~There is absolutely no warranty for GDB. Type "show warranty" for | |
16535 | ~ details. | |
16536 | ~This GDB was configured as | |
16537 | "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi". | |
16538 | ^done | |
16539 | (@value{GDBP}) | |
16540 | @end smallexample | |
16541 | ||
16542 | @subheading The @code{-interpreter-exec} Command | |
16543 | @findex -interpreter-exec | |
16544 | ||
16545 | @subheading Synopsis | |
16546 | ||
16547 | @smallexample | |
16548 | -interpreter-exec @var{interpreter} @var{command} | |
16549 | @end smallexample | |
16550 | ||
16551 | Execute the specified @var{command} in the given @var{interpreter}. | |
16552 | ||
16553 | @subheading @value{GDBN} Command | |
16554 | ||
16555 | The corresponding @value{GDBN} command is @samp{interpreter-exec}. | |
16556 | ||
16557 | @subheading Example | |
16558 | ||
16559 | @smallexample | |
16560 | (@value{GDBP}) | |
16561 | -interpreter-exec console "break main" | |
16562 | &"During symbol reading, couldn't parse type; debugger out of date?.\n" | |
16563 | &"During symbol reading, bad structure-type format.\n" | |
16564 | ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n" | |
16565 | ^done | |
16566 | (@value{GDBP}) | |
16567 | @end smallexample | |
16568 | ||
16569 | @ignore | |
16570 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
16571 | @node GDB/MI Kod Commands | |
16572 | @section @sc{gdb/mi} Kod Commands | |
16573 | ||
16574 | The Kod commands are not implemented. | |
16575 | ||
16576 | @c @subheading -kod-info | |
16577 | ||
16578 | @c @subheading -kod-list | |
16579 | ||
16580 | @c @subheading -kod-list-object-types | |
16581 | ||
16582 | @c @subheading -kod-show | |
16583 | ||
16584 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
16585 | @node GDB/MI Memory Overlay Commands | |
16586 | @section @sc{gdb/mi} Memory Overlay Commands | |
16587 | ||
16588 | The memory overlay commands are not implemented. | |
16589 | ||
16590 | @c @subheading -overlay-auto | |
16591 | ||
16592 | @c @subheading -overlay-list-mapping-state | |
16593 | ||
16594 | @c @subheading -overlay-list-overlays | |
16595 | ||
16596 | @c @subheading -overlay-map | |
16597 | ||
16598 | @c @subheading -overlay-off | |
16599 | ||
16600 | @c @subheading -overlay-on | |
16601 | ||
16602 | @c @subheading -overlay-unmap | |
16603 | ||
16604 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
16605 | @node GDB/MI Signal Handling Commands | |
16606 | @section @sc{gdb/mi} Signal Handling Commands | |
16607 | ||
16608 | Signal handling commands are not implemented. | |
16609 | ||
16610 | @c @subheading -signal-handle | |
16611 | ||
16612 | @c @subheading -signal-list-handle-actions | |
16613 | ||
16614 | @c @subheading -signal-list-signal-types | |
16615 | @end ignore | |
16616 | ||
16617 | ||
16618 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
16619 | @node GDB/MI Stack Manipulation | |
16620 | @section @sc{gdb/mi} Stack Manipulation Commands | |
16621 | ||
16622 | ||
16623 | @subheading The @code{-stack-info-frame} Command | |
16624 | @findex -stack-info-frame | |
16625 | ||
16626 | @subsubheading Synopsis | |
16627 | ||
16628 | @smallexample | |
16629 | -stack-info-frame | |
16630 | @end smallexample | |
16631 | ||
16632 | Get info on the current frame. | |
16633 | ||
16634 | @subsubheading @value{GDBN} Command | |
16635 | ||
16636 | The corresponding @value{GDBN} command is @samp{info frame} or @samp{frame} | |
16637 | (without arguments). | |
16638 | ||
16639 | @subsubheading Example | |
16640 | N.A. | |
16641 | ||
16642 | @subheading The @code{-stack-info-depth} Command | |
16643 | @findex -stack-info-depth | |
16644 | ||
16645 | @subsubheading Synopsis | |
16646 | ||
16647 | @smallexample | |
16648 | -stack-info-depth [ @var{max-depth} ] | |
16649 | @end smallexample | |
16650 | ||
16651 | Return the depth of the stack. If the integer argument @var{max-depth} | |
16652 | is specified, do not count beyond @var{max-depth} frames. | |
16653 | ||
16654 | @subsubheading @value{GDBN} Command | |
16655 | ||
16656 | There's no equivalent @value{GDBN} command. | |
16657 | ||
16658 | @subsubheading Example | |
16659 | ||
16660 | For a stack with frame levels 0 through 11: | |
16661 | ||
16662 | @smallexample | |
16663 | (@value{GDBP}) | |
16664 | -stack-info-depth | |
16665 | ^done,depth="12" | |
16666 | (@value{GDBP}) | |
16667 | -stack-info-depth 4 | |
16668 | ^done,depth="4" | |
16669 | (@value{GDBP}) | |
16670 | -stack-info-depth 12 | |
16671 | ^done,depth="12" | |
16672 | (@value{GDBP}) | |
16673 | -stack-info-depth 11 | |
16674 | ^done,depth="11" | |
16675 | (@value{GDBP}) | |
16676 | -stack-info-depth 13 | |
16677 | ^done,depth="12" | |
16678 | (@value{GDBP}) | |
16679 | @end smallexample | |
16680 | ||
16681 | @subheading The @code{-stack-list-arguments} Command | |
16682 | @findex -stack-list-arguments | |
16683 | ||
16684 | @subsubheading Synopsis | |
16685 | ||
16686 | @smallexample | |
16687 | -stack-list-arguments @var{show-values} | |
16688 | [ @var{low-frame} @var{high-frame} ] | |
16689 | @end smallexample | |
16690 | ||
16691 | Display a list of the arguments for the frames between @var{low-frame} | |
16692 | and @var{high-frame} (inclusive). If @var{low-frame} and | |
16693 | @var{high-frame} are not provided, list the arguments for the whole call | |
16694 | stack. | |
16695 | ||
16696 | The @var{show-values} argument must have a value of 0 or 1. A value of | |
16697 | 0 means that only the names of the arguments are listed, a value of 1 | |
16698 | means that both names and values of the arguments are printed. | |
16699 | ||
16700 | @subsubheading @value{GDBN} Command | |
16701 | ||
16702 | @value{GDBN} does not have an equivalent command. @code{gdbtk} has a | |
16703 | @samp{gdb_get_args} command which partially overlaps with the | |
16704 | functionality of @samp{-stack-list-arguments}. | |
16705 | ||
16706 | @subsubheading Example | |
16707 | ||
16708 | @smallexample | |
16709 | (@value{GDBP}) | |
16710 | -stack-list-frames | |
16711 | ^done, | |
16712 | stack=[ | |
16713 | frame=@{level="0",addr="0x00010734",func="callee4", | |
16714 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@}, | |
16715 | frame=@{level="1",addr="0x0001076c",func="callee3", | |
16716 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="17"@}, | |
16717 | frame=@{level="2",addr="0x0001078c",func="callee2", | |
16718 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="22"@}, | |
16719 | frame=@{level="3",addr="0x000107b4",func="callee1", | |
16720 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="27"@}, | |
16721 | frame=@{level="4",addr="0x000107e0",func="main", | |
16722 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="32"@}] | |
16723 | (@value{GDBP}) | |
16724 | -stack-list-arguments 0 | |
16725 | ^done, | |
16726 | stack-args=[ | |
16727 | frame=@{level="0",args=[]@}, | |
16728 | frame=@{level="1",args=[name="strarg"]@}, | |
16729 | frame=@{level="2",args=[name="intarg",name="strarg"]@}, | |
16730 | frame=@{level="3",args=[name="intarg",name="strarg",name="fltarg"]@}, | |
16731 | frame=@{level="4",args=[]@}] | |
16732 | (@value{GDBP}) | |
16733 | -stack-list-arguments 1 | |
16734 | ^done, | |
16735 | stack-args=[ | |
16736 | frame=@{level="0",args=[]@}, | |
16737 | frame=@{level="1", | |
16738 | args=[@{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
16739 | frame=@{level="2",args=[ | |
16740 | @{name="intarg",value="2"@}, | |
16741 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
16742 | @{frame=@{level="3",args=[ | |
16743 | @{name="intarg",value="2"@}, | |
16744 | @{name="strarg",value="0x11940 \"A string argument.\""@}, | |
16745 | @{name="fltarg",value="3.5"@}]@}, | |
16746 | frame=@{level="4",args=[]@}] | |
16747 | (@value{GDBP}) | |
16748 | -stack-list-arguments 0 2 2 | |
16749 | ^done,stack-args=[frame=@{level="2",args=[name="intarg",name="strarg"]@}] | |
16750 | (@value{GDBP}) | |
16751 | -stack-list-arguments 1 2 2 | |
16752 | ^done,stack-args=[frame=@{level="2", | |
16753 | args=[@{name="intarg",value="2"@}, | |
16754 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}] | |
16755 | (@value{GDBP}) | |
16756 | @end smallexample | |
16757 | ||
16758 | @c @subheading -stack-list-exception-handlers | |
16759 | ||
16760 | ||
16761 | @subheading The @code{-stack-list-frames} Command | |
16762 | @findex -stack-list-frames | |
16763 | ||
16764 | @subsubheading Synopsis | |
16765 | ||
16766 | @smallexample | |
16767 | -stack-list-frames [ @var{low-frame} @var{high-frame} ] | |
16768 | @end smallexample | |
16769 | ||
16770 | List the frames currently on the stack. For each frame it displays the | |
16771 | following info: | |
16772 | ||
16773 | @table @samp | |
16774 | @item @var{level} | |
16775 | The frame number, 0 being the topmost frame, i.e. the innermost function. | |
16776 | @item @var{addr} | |
16777 | The @code{$pc} value for that frame. | |
16778 | @item @var{func} | |
16779 | Function name. | |
16780 | @item @var{file} | |
16781 | File name of the source file where the function lives. | |
16782 | @item @var{line} | |
16783 | Line number corresponding to the @code{$pc}. | |
16784 | @end table | |
16785 | ||
16786 | If invoked without arguments, this command prints a backtrace for the | |
16787 | whole stack. If given two integer arguments, it shows the frames whose | |
16788 | levels are between the two arguments (inclusive). If the two arguments | |
16789 | are equal, it shows the single frame at the corresponding level. | |
16790 | ||
16791 | @subsubheading @value{GDBN} Command | |
16792 | ||
16793 | The corresponding @value{GDBN} commands are @samp{backtrace} and @samp{where}. | |
16794 | ||
16795 | @subsubheading Example | |
16796 | ||
16797 | Full stack backtrace: | |
16798 | ||
16799 | @smallexample | |
16800 | (@value{GDBP}) | |
16801 | -stack-list-frames | |
16802 | ^done,stack= | |
16803 | [frame=@{level="0",addr="0x0001076c",func="foo", | |
16804 | file="recursive2.c",line="11"@}, | |
16805 | frame=@{level="1",addr="0x000107a4",func="foo", | |
16806 | file="recursive2.c",line="14"@}, | |
16807 | frame=@{level="2",addr="0x000107a4",func="foo", | |
16808 | file="recursive2.c",line="14"@}, | |
16809 | frame=@{level="3",addr="0x000107a4",func="foo", | |
16810 | file="recursive2.c",line="14"@}, | |
16811 | frame=@{level="4",addr="0x000107a4",func="foo", | |
16812 | file="recursive2.c",line="14"@}, | |
16813 | frame=@{level="5",addr="0x000107a4",func="foo", | |
16814 | file="recursive2.c",line="14"@}, | |
16815 | frame=@{level="6",addr="0x000107a4",func="foo", | |
16816 | file="recursive2.c",line="14"@}, | |
16817 | frame=@{level="7",addr="0x000107a4",func="foo", | |
16818 | file="recursive2.c",line="14"@}, | |
16819 | frame=@{level="8",addr="0x000107a4",func="foo", | |
16820 | file="recursive2.c",line="14"@}, | |
16821 | frame=@{level="9",addr="0x000107a4",func="foo", | |
16822 | file="recursive2.c",line="14"@}, | |
16823 | frame=@{level="10",addr="0x000107a4",func="foo", | |
16824 | file="recursive2.c",line="14"@}, | |
16825 | frame=@{level="11",addr="0x00010738",func="main", | |
16826 | file="recursive2.c",line="4"@}] | |
16827 | (@value{GDBP}) | |
16828 | @end smallexample | |
16829 | ||
16830 | Show frames between @var{low_frame} and @var{high_frame}: | |
16831 | ||
16832 | @smallexample | |
16833 | (@value{GDBP}) | |
16834 | -stack-list-frames 3 5 | |
16835 | ^done,stack= | |
16836 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
16837 | file="recursive2.c",line="14"@}, | |
16838 | frame=@{level="4",addr="0x000107a4",func="foo", | |
16839 | file="recursive2.c",line="14"@}, | |
16840 | frame=@{level="5",addr="0x000107a4",func="foo", | |
16841 | file="recursive2.c",line="14"@}] | |
16842 | (@value{GDBP}) | |
16843 | @end smallexample | |
16844 | ||
16845 | Show a single frame: | |
16846 | ||
16847 | @smallexample | |
16848 | (@value{GDBP}) | |
16849 | -stack-list-frames 3 3 | |
16850 | ^done,stack= | |
16851 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
16852 | file="recursive2.c",line="14"@}] | |
16853 | (@value{GDBP}) | |
16854 | @end smallexample | |
16855 | ||
16856 | ||
16857 | @subheading The @code{-stack-list-locals} Command | |
16858 | @findex -stack-list-locals | |
16859 | ||
16860 | @subsubheading Synopsis | |
16861 | ||
16862 | @smallexample | |
16863 | -stack-list-locals @var{print-values} | |
16864 | @end smallexample | |
16865 | ||
16866 | Display the local variable names for the current frame. With an | |
16867 | argument of 0 prints only the names of the variables, with argument of 1 | |
16868 | prints also their values. | |
16869 | ||
16870 | @subsubheading @value{GDBN} Command | |
16871 | ||
16872 | @samp{info locals} in @value{GDBN}, @samp{gdb_get_locals} in @code{gdbtk}. | |
16873 | ||
16874 | @subsubheading Example | |
16875 | ||
16876 | @smallexample | |
16877 | (@value{GDBP}) | |
16878 | -stack-list-locals 0 | |
16879 | ^done,locals=[name="A",name="B",name="C"] | |
16880 | (@value{GDBP}) | |
16881 | -stack-list-locals 1 | |
16882 | ^done,locals=[@{name="A",value="1"@},@{name="B",value="2"@}, | |
16883 | @{name="C",value="3"@}] | |
16884 | (@value{GDBP}) | |
16885 | @end smallexample | |
16886 | ||
16887 | ||
16888 | @subheading The @code{-stack-select-frame} Command | |
16889 | @findex -stack-select-frame | |
16890 | ||
16891 | @subsubheading Synopsis | |
16892 | ||
16893 | @smallexample | |
16894 | -stack-select-frame @var{framenum} | |
16895 | @end smallexample | |
16896 | ||
16897 | Change the current frame. Select a different frame @var{framenum} on | |
16898 | the stack. | |
16899 | ||
16900 | @subsubheading @value{GDBN} Command | |
16901 | ||
16902 | The corresponding @value{GDBN} commands are @samp{frame}, @samp{up}, | |
16903 | @samp{down}, @samp{select-frame}, @samp{up-silent}, and @samp{down-silent}. | |
16904 | ||
16905 | @subsubheading Example | |
16906 | ||
16907 | @smallexample | |
16908 | (@value{GDBP}) | |
16909 | -stack-select-frame 2 | |
16910 | ^done | |
16911 | (@value{GDBP}) | |
16912 | @end smallexample | |
16913 | ||
16914 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
16915 | @node GDB/MI Symbol Query | |
16916 | @section @sc{gdb/mi} Symbol Query Commands | |
16917 | ||
16918 | ||
16919 | @subheading The @code{-symbol-info-address} Command | |
16920 | @findex -symbol-info-address | |
16921 | ||
16922 | @subsubheading Synopsis | |
16923 | ||
16924 | @smallexample | |
16925 | -symbol-info-address @var{symbol} | |
16926 | @end smallexample | |
16927 | ||
16928 | Describe where @var{symbol} is stored. | |
16929 | ||
16930 | @subsubheading @value{GDBN} Command | |
16931 | ||
16932 | The corresponding @value{GDBN} command is @samp{info address}. | |
16933 | ||
16934 | @subsubheading Example | |
16935 | N.A. | |
16936 | ||
16937 | ||
16938 | @subheading The @code{-symbol-info-file} Command | |
16939 | @findex -symbol-info-file | |
16940 | ||
16941 | @subsubheading Synopsis | |
16942 | ||
16943 | @smallexample | |
16944 | -symbol-info-file | |
16945 | @end smallexample | |
16946 | ||
16947 | Show the file for the symbol. | |
16948 | ||
16949 | @subsubheading @value{GDBN} Command | |
16950 | ||
16951 | There's no equivalent @value{GDBN} command. @code{gdbtk} has | |
16952 | @samp{gdb_find_file}. | |
16953 | ||
16954 | @subsubheading Example | |
16955 | N.A. | |
16956 | ||
16957 | ||
16958 | @subheading The @code{-symbol-info-function} Command | |
16959 | @findex -symbol-info-function | |
16960 | ||
16961 | @subsubheading Synopsis | |
16962 | ||
16963 | @smallexample | |
16964 | -symbol-info-function | |
16965 | @end smallexample | |
16966 | ||
16967 | Show which function the symbol lives in. | |
16968 | ||
16969 | @subsubheading @value{GDBN} Command | |
16970 | ||
16971 | @samp{gdb_get_function} in @code{gdbtk}. | |
16972 | ||
16973 | @subsubheading Example | |
16974 | N.A. | |
16975 | ||
16976 | ||
16977 | @subheading The @code{-symbol-info-line} Command | |
16978 | @findex -symbol-info-line | |
16979 | ||
16980 | @subsubheading Synopsis | |
16981 | ||
16982 | @smallexample | |
16983 | -symbol-info-line | |
16984 | @end smallexample | |
16985 | ||
16986 | Show the core addresses of the code for a source line. | |
16987 | ||
16988 | @subsubheading @value{GDBN} Command | |
16989 | ||
16990 | The corresponding @value{GDBN} comamnd is @samp{info line}. | |
16991 | @code{gdbtk} has the @samp{gdb_get_line} and @samp{gdb_get_file} commands. | |
16992 | ||
16993 | @subsubheading Example | |
16994 | N.A. | |
16995 | ||
16996 | ||
16997 | @subheading The @code{-symbol-info-symbol} Command | |
16998 | @findex -symbol-info-symbol | |
16999 | ||
17000 | @subsubheading Synopsis | |
17001 | ||
17002 | @smallexample | |
17003 | -symbol-info-symbol @var{addr} | |
17004 | @end smallexample | |
17005 | ||
17006 | Describe what symbol is at location @var{addr}. | |
17007 | ||
17008 | @subsubheading @value{GDBN} Command | |
17009 | ||
17010 | The corresponding @value{GDBN} command is @samp{info symbol}. | |
17011 | ||
17012 | @subsubheading Example | |
17013 | N.A. | |
17014 | ||
17015 | ||
17016 | @subheading The @code{-symbol-list-functions} Command | |
17017 | @findex -symbol-list-functions | |
17018 | ||
17019 | @subsubheading Synopsis | |
17020 | ||
17021 | @smallexample | |
17022 | -symbol-list-functions | |
17023 | @end smallexample | |
17024 | ||
17025 | List the functions in the executable. | |
17026 | ||
17027 | @subsubheading @value{GDBN} Command | |
17028 | ||
17029 | @samp{info functions} in @value{GDBN}, @samp{gdb_listfunc} and | |
17030 | @samp{gdb_search} in @code{gdbtk}. | |
17031 | ||
17032 | @subsubheading Example | |
17033 | N.A. | |
17034 | ||
17035 | ||
17036 | @subheading The @code{-symbol-list-types} Command | |
17037 | @findex -symbol-list-types | |
17038 | ||
17039 | @subsubheading Synopsis | |
17040 | ||
17041 | @smallexample | |
17042 | -symbol-list-types | |
17043 | @end smallexample | |
17044 | ||
17045 | List all the type names. | |
17046 | ||
17047 | @subsubheading @value{GDBN} Command | |
17048 | ||
17049 | The corresponding commands are @samp{info types} in @value{GDBN}, | |
17050 | @samp{gdb_search} in @code{gdbtk}. | |
17051 | ||
17052 | @subsubheading Example | |
17053 | N.A. | |
17054 | ||
17055 | ||
17056 | @subheading The @code{-symbol-list-variables} Command | |
17057 | @findex -symbol-list-variables | |
17058 | ||
17059 | @subsubheading Synopsis | |
17060 | ||
17061 | @smallexample | |
17062 | -symbol-list-variables | |
17063 | @end smallexample | |
17064 | ||
17065 | List all the global and static variable names. | |
17066 | ||
17067 | @subsubheading @value{GDBN} Command | |
17068 | ||
17069 | @samp{info variables} in @value{GDBN}, @samp{gdb_search} in @code{gdbtk}. | |
17070 | ||
17071 | @subsubheading Example | |
17072 | N.A. | |
17073 | ||
17074 | ||
17075 | @subheading The @code{-symbol-locate} Command | |
17076 | @findex -symbol-locate | |
17077 | ||
17078 | @subsubheading Synopsis | |
17079 | ||
17080 | @smallexample | |
17081 | -symbol-locate | |
17082 | @end smallexample | |
17083 | ||
17084 | @subsubheading @value{GDBN} Command | |
17085 | ||
17086 | @samp{gdb_loc} in @code{gdbtk}. | |
17087 | ||
17088 | @subsubheading Example | |
17089 | N.A. | |
17090 | ||
17091 | ||
17092 | @subheading The @code{-symbol-type} Command | |
17093 | @findex -symbol-type | |
17094 | ||
17095 | @subsubheading Synopsis | |
17096 | ||
17097 | @smallexample | |
17098 | -symbol-type @var{variable} | |
17099 | @end smallexample | |
17100 | ||
17101 | Show type of @var{variable}. | |
17102 | ||
17103 | @subsubheading @value{GDBN} Command | |
17104 | ||
17105 | The corresponding @value{GDBN} command is @samp{ptype}, @code{gdbtk} has | |
17106 | @samp{gdb_obj_variable}. | |
17107 | ||
17108 | @subsubheading Example | |
17109 | N.A. | |
17110 | ||
17111 | ||
17112 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17113 | @node GDB/MI Target Manipulation | |
17114 | @section @sc{gdb/mi} Target Manipulation Commands | |
17115 | ||
17116 | ||
17117 | @subheading The @code{-target-attach} Command | |
17118 | @findex -target-attach | |
17119 | ||
17120 | @subsubheading Synopsis | |
17121 | ||
17122 | @smallexample | |
17123 | -target-attach @var{pid} | @var{file} | |
17124 | @end smallexample | |
17125 | ||
17126 | Attach to a process @var{pid} or a file @var{file} outside of @value{GDBN}. | |
17127 | ||
17128 | @subsubheading @value{GDBN} command | |
17129 | ||
17130 | The corresponding @value{GDBN} command is @samp{attach}. | |
17131 | ||
17132 | @subsubheading Example | |
17133 | N.A. | |
17134 | ||
17135 | ||
17136 | @subheading The @code{-target-compare-sections} Command | |
17137 | @findex -target-compare-sections | |
17138 | ||
17139 | @subsubheading Synopsis | |
17140 | ||
17141 | @smallexample | |
17142 | -target-compare-sections [ @var{section} ] | |
17143 | @end smallexample | |
17144 | ||
17145 | Compare data of section @var{section} on target to the exec file. | |
17146 | Without the argument, all sections are compared. | |
17147 | ||
17148 | @subsubheading @value{GDBN} Command | |
17149 | ||
17150 | The @value{GDBN} equivalent is @samp{compare-sections}. | |
17151 | ||
17152 | @subsubheading Example | |
17153 | N.A. | |
17154 | ||
17155 | ||
17156 | @subheading The @code{-target-detach} Command | |
17157 | @findex -target-detach | |
17158 | ||
17159 | @subsubheading Synopsis | |
17160 | ||
17161 | @smallexample | |
17162 | -target-detach | |
17163 | @end smallexample | |
17164 | ||
17165 | Disconnect from the remote target. There's no output. | |
17166 | ||
17167 | @subsubheading @value{GDBN} command | |
17168 | ||
17169 | The corresponding @value{GDBN} command is @samp{detach}. | |
17170 | ||
17171 | @subsubheading Example | |
17172 | ||
17173 | @smallexample | |
17174 | (@value{GDBP}) | |
17175 | -target-detach | |
17176 | ^done | |
17177 | (@value{GDBP}) | |
17178 | @end smallexample | |
17179 | ||
17180 | ||
17181 | @subheading The @code{-target-download} Command | |
17182 | @findex -target-download | |
17183 | ||
17184 | @subsubheading Synopsis | |
17185 | ||
17186 | @smallexample | |
17187 | -target-download | |
17188 | @end smallexample | |
17189 | ||
17190 | Loads the executable onto the remote target. | |
17191 | It prints out an update message every half second, which includes the fields: | |
17192 | ||
17193 | @table @samp | |
17194 | @item section | |
17195 | The name of the section. | |
17196 | @item section-sent | |
17197 | The size of what has been sent so far for that section. | |
17198 | @item section-size | |
17199 | The size of the section. | |
17200 | @item total-sent | |
17201 | The total size of what was sent so far (the current and the previous sections). | |
17202 | @item total-size | |
17203 | The size of the overall executable to download. | |
17204 | @end table | |
17205 | ||
17206 | @noindent | |
17207 | Each message is sent as status record (@pxref{GDB/MI Output Syntax, , | |
17208 | @sc{gdb/mi} Output Syntax}). | |
17209 | ||
17210 | In addition, it prints the name and size of the sections, as they are | |
17211 | downloaded. These messages include the following fields: | |
17212 | ||
17213 | @table @samp | |
17214 | @item section | |
17215 | The name of the section. | |
17216 | @item section-size | |
17217 | The size of the section. | |
17218 | @item total-size | |
17219 | The size of the overall executable to download. | |
17220 | @end table | |
17221 | ||
17222 | @noindent | |
17223 | At the end, a summary is printed. | |
17224 | ||
17225 | @subsubheading @value{GDBN} Command | |
17226 | ||
17227 | The corresponding @value{GDBN} command is @samp{load}. | |
17228 | ||
17229 | @subsubheading Example | |
17230 | ||
17231 | Note: each status message appears on a single line. Here the messages | |
17232 | have been broken down so that they can fit onto a page. | |
17233 | ||
17234 | @smallexample | |
17235 | (@value{GDBP}) | |
17236 | -target-download | |
17237 | +download,@{section=".text",section-size="6668",total-size="9880"@} | |
17238 | +download,@{section=".text",section-sent="512",section-size="6668", | |
17239 | total-sent="512",total-size="9880"@} | |
17240 | +download,@{section=".text",section-sent="1024",section-size="6668", | |
17241 | total-sent="1024",total-size="9880"@} | |
17242 | +download,@{section=".text",section-sent="1536",section-size="6668", | |
17243 | total-sent="1536",total-size="9880"@} | |
17244 | +download,@{section=".text",section-sent="2048",section-size="6668", | |
17245 | total-sent="2048",total-size="9880"@} | |
17246 | +download,@{section=".text",section-sent="2560",section-size="6668", | |
17247 | total-sent="2560",total-size="9880"@} | |
17248 | +download,@{section=".text",section-sent="3072",section-size="6668", | |
17249 | total-sent="3072",total-size="9880"@} | |
17250 | +download,@{section=".text",section-sent="3584",section-size="6668", | |
17251 | total-sent="3584",total-size="9880"@} | |
17252 | +download,@{section=".text",section-sent="4096",section-size="6668", | |
17253 | total-sent="4096",total-size="9880"@} | |
17254 | +download,@{section=".text",section-sent="4608",section-size="6668", | |
17255 | total-sent="4608",total-size="9880"@} | |
17256 | +download,@{section=".text",section-sent="5120",section-size="6668", | |
17257 | total-sent="5120",total-size="9880"@} | |
17258 | +download,@{section=".text",section-sent="5632",section-size="6668", | |
17259 | total-sent="5632",total-size="9880"@} | |
17260 | +download,@{section=".text",section-sent="6144",section-size="6668", | |
17261 | total-sent="6144",total-size="9880"@} | |
17262 | +download,@{section=".text",section-sent="6656",section-size="6668", | |
17263 | total-sent="6656",total-size="9880"@} | |
17264 | +download,@{section=".init",section-size="28",total-size="9880"@} | |
17265 | +download,@{section=".fini",section-size="28",total-size="9880"@} | |
17266 | +download,@{section=".data",section-size="3156",total-size="9880"@} | |
17267 | +download,@{section=".data",section-sent="512",section-size="3156", | |
17268 | total-sent="7236",total-size="9880"@} | |
17269 | +download,@{section=".data",section-sent="1024",section-size="3156", | |
17270 | total-sent="7748",total-size="9880"@} | |
17271 | +download,@{section=".data",section-sent="1536",section-size="3156", | |
17272 | total-sent="8260",total-size="9880"@} | |
17273 | +download,@{section=".data",section-sent="2048",section-size="3156", | |
17274 | total-sent="8772",total-size="9880"@} | |
17275 | +download,@{section=".data",section-sent="2560",section-size="3156", | |
17276 | total-sent="9284",total-size="9880"@} | |
17277 | +download,@{section=".data",section-sent="3072",section-size="3156", | |
17278 | total-sent="9796",total-size="9880"@} | |
17279 | ^done,address="0x10004",load-size="9880",transfer-rate="6586", | |
17280 | write-rate="429" | |
17281 | (@value{GDBP}) | |
17282 | @end smallexample | |
17283 | ||
17284 | ||
17285 | @subheading The @code{-target-exec-status} Command | |
17286 | @findex -target-exec-status | |
17287 | ||
17288 | @subsubheading Synopsis | |
17289 | ||
17290 | @smallexample | |
17291 | -target-exec-status | |
17292 | @end smallexample | |
17293 | ||
17294 | Provide information on the state of the target (whether it is running or | |
17295 | not, for instance). | |
17296 | ||
17297 | @subsubheading @value{GDBN} Command | |
17298 | ||
17299 | There's no equivalent @value{GDBN} command. | |
17300 | ||
17301 | @subsubheading Example | |
17302 | N.A. | |
17303 | ||
17304 | ||
17305 | @subheading The @code{-target-list-available-targets} Command | |
17306 | @findex -target-list-available-targets | |
17307 | ||
17308 | @subsubheading Synopsis | |
17309 | ||
17310 | @smallexample | |
17311 | -target-list-available-targets | |
17312 | @end smallexample | |
17313 | ||
17314 | List the possible targets to connect to. | |
17315 | ||
17316 | @subsubheading @value{GDBN} Command | |
17317 | ||
17318 | The corresponding @value{GDBN} command is @samp{help target}. | |
17319 | ||
17320 | @subsubheading Example | |
17321 | N.A. | |
17322 | ||
17323 | ||
17324 | @subheading The @code{-target-list-current-targets} Command | |
17325 | @findex -target-list-current-targets | |
17326 | ||
17327 | @subsubheading Synopsis | |
17328 | ||
17329 | @smallexample | |
17330 | -target-list-current-targets | |
17331 | @end smallexample | |
17332 | ||
17333 | Describe the current target. | |
17334 | ||
17335 | @subsubheading @value{GDBN} Command | |
17336 | ||
17337 | The corresponding information is printed by @samp{info file} (among | |
17338 | other things). | |
17339 | ||
17340 | @subsubheading Example | |
17341 | N.A. | |
17342 | ||
17343 | ||
17344 | @subheading The @code{-target-list-parameters} Command | |
17345 | @findex -target-list-parameters | |
17346 | ||
17347 | @subsubheading Synopsis | |
17348 | ||
17349 | @smallexample | |
17350 | -target-list-parameters | |
17351 | @end smallexample | |
17352 | ||
17353 | @c ???? | |
17354 | ||
17355 | @subsubheading @value{GDBN} Command | |
17356 | ||
17357 | No equivalent. | |
17358 | ||
17359 | @subsubheading Example | |
17360 | N.A. | |
17361 | ||
17362 | ||
17363 | @subheading The @code{-target-select} Command | |
17364 | @findex -target-select | |
17365 | ||
17366 | @subsubheading Synopsis | |
17367 | ||
17368 | @smallexample | |
17369 | -target-select @var{type} @var{parameters @dots{}} | |
17370 | @end smallexample | |
17371 | ||
17372 | Connect @value{GDBN} to the remote target. This command takes two args: | |
17373 | ||
17374 | @table @samp | |
17375 | @item @var{type} | |
17376 | The type of target, for instance @samp{async}, @samp{remote}, etc. | |
17377 | @item @var{parameters} | |
17378 | Device names, host names and the like. @xref{Target Commands, , | |
17379 | Commands for managing targets}, for more details. | |
17380 | @end table | |
17381 | ||
17382 | The output is a connection notification, followed by the address at | |
17383 | which the target program is, in the following form: | |
17384 | ||
17385 | @smallexample | |
17386 | ^connected,addr="@var{address}",func="@var{function name}", | |
17387 | args=[@var{arg list}] | |
17388 | @end smallexample | |
17389 | ||
17390 | @subsubheading @value{GDBN} Command | |
17391 | ||
17392 | The corresponding @value{GDBN} command is @samp{target}. | |
17393 | ||
17394 | @subsubheading Example | |
17395 | ||
17396 | @smallexample | |
17397 | (@value{GDBP}) | |
17398 | -target-select async /dev/ttya | |
17399 | ^connected,addr="0xfe00a300",func="??",args=[] | |
17400 | (@value{GDBP}) | |
17401 | @end smallexample | |
17402 | ||
17403 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17404 | @node GDB/MI Thread Commands | |
17405 | @section @sc{gdb/mi} Thread Commands | |
17406 | ||
17407 | ||
17408 | @subheading The @code{-thread-info} Command | |
17409 | @findex -thread-info | |
17410 | ||
17411 | @subsubheading Synopsis | |
17412 | ||
17413 | @smallexample | |
17414 | -thread-info | |
17415 | @end smallexample | |
17416 | ||
17417 | @subsubheading @value{GDBN} command | |
17418 | ||
17419 | No equivalent. | |
17420 | ||
17421 | @subsubheading Example | |
17422 | N.A. | |
17423 | ||
17424 | ||
17425 | @subheading The @code{-thread-list-all-threads} Command | |
17426 | @findex -thread-list-all-threads | |
17427 | ||
17428 | @subsubheading Synopsis | |
17429 | ||
17430 | @smallexample | |
17431 | -thread-list-all-threads | |
17432 | @end smallexample | |
17433 | ||
17434 | @subsubheading @value{GDBN} Command | |
17435 | ||
17436 | The equivalent @value{GDBN} command is @samp{info threads}. | |
17437 | ||
17438 | @subsubheading Example | |
17439 | N.A. | |
17440 | ||
17441 | ||
17442 | @subheading The @code{-thread-list-ids} Command | |
17443 | @findex -thread-list-ids | |
17444 | ||
17445 | @subsubheading Synopsis | |
17446 | ||
17447 | @smallexample | |
17448 | -thread-list-ids | |
17449 | @end smallexample | |
17450 | ||
17451 | Produces a list of the currently known @value{GDBN} thread ids. At the | |
17452 | end of the list it also prints the total number of such threads. | |
17453 | ||
17454 | @subsubheading @value{GDBN} Command | |
17455 | ||
17456 | Part of @samp{info threads} supplies the same information. | |
17457 | ||
17458 | @subsubheading Example | |
17459 | ||
17460 | No threads present, besides the main process: | |
17461 | ||
17462 | @smallexample | |
17463 | (@value{GDBP}) | |
17464 | -thread-list-ids | |
17465 | ^done,thread-ids=@{@},number-of-threads="0" | |
17466 | (@value{GDBP}) | |
17467 | @end smallexample | |
17468 | ||
17469 | ||
17470 | Several threads: | |
17471 | ||
17472 | @smallexample | |
17473 | (@value{GDBP}) | |
17474 | -thread-list-ids | |
17475 | ^done,thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
17476 | number-of-threads="3" | |
17477 | (@value{GDBP}) | |
17478 | @end smallexample | |
17479 | ||
17480 | ||
17481 | @subheading The @code{-thread-select} Command | |
17482 | @findex -thread-select | |
17483 | ||
17484 | @subsubheading Synopsis | |
17485 | ||
17486 | @smallexample | |
17487 | -thread-select @var{threadnum} | |
17488 | @end smallexample | |
17489 | ||
17490 | Make @var{threadnum} the current thread. It prints the number of the new | |
17491 | current thread, and the topmost frame for that thread. | |
17492 | ||
17493 | @subsubheading @value{GDBN} Command | |
17494 | ||
17495 | The corresponding @value{GDBN} command is @samp{thread}. | |
17496 | ||
17497 | @subsubheading Example | |
17498 | ||
17499 | @smallexample | |
17500 | (@value{GDBP}) | |
17501 | -exec-next | |
17502 | ^running | |
17503 | (@value{GDBP}) | |
17504 | *stopped,reason="end-stepping-range",thread-id="2",line="187", | |
17505 | file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c" | |
17506 | (@value{GDBP}) | |
17507 | -thread-list-ids | |
17508 | ^done, | |
17509 | thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
17510 | number-of-threads="3" | |
17511 | (@value{GDBP}) | |
17512 | -thread-select 3 | |
17513 | ^done,new-thread-id="3", | |
17514 | frame=@{level="0",func="vprintf", | |
17515 | args=[@{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""@}, | |
17516 | @{name="arg",value="0x2"@}],file="vprintf.c",line="31"@} | |
17517 | (@value{GDBP}) | |
17518 | @end smallexample | |
17519 | ||
17520 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17521 | @node GDB/MI Tracepoint Commands | |
17522 | @section @sc{gdb/mi} Tracepoint Commands | |
17523 | ||
17524 | The tracepoint commands are not yet implemented. | |
17525 | ||
17526 | @c @subheading -trace-actions | |
17527 | ||
17528 | @c @subheading -trace-delete | |
17529 | ||
17530 | @c @subheading -trace-disable | |
17531 | ||
17532 | @c @subheading -trace-dump | |
17533 | ||
17534 | @c @subheading -trace-enable | |
17535 | ||
17536 | @c @subheading -trace-exists | |
17537 | ||
17538 | @c @subheading -trace-find | |
17539 | ||
17540 | @c @subheading -trace-frame-number | |
17541 | ||
17542 | @c @subheading -trace-info | |
17543 | ||
17544 | @c @subheading -trace-insert | |
17545 | ||
17546 | @c @subheading -trace-list | |
17547 | ||
17548 | @c @subheading -trace-pass-count | |
17549 | ||
17550 | @c @subheading -trace-save | |
17551 | ||
17552 | @c @subheading -trace-start | |
17553 | ||
17554 | @c @subheading -trace-stop | |
17555 | ||
17556 | ||
17557 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
17558 | @node GDB/MI Variable Objects | |
17559 | @section @sc{gdb/mi} Variable Objects | |
17560 | ||
17561 | ||
17562 | @subheading Motivation for Variable Objects in @sc{gdb/mi} | |
17563 | ||
17564 | For the implementation of a variable debugger window (locals, watched | |
17565 | expressions, etc.), we are proposing the adaptation of the existing code | |
17566 | used by @code{Insight}. | |
17567 | ||
17568 | The two main reasons for that are: | |
17569 | ||
17570 | @enumerate 1 | |
17571 | @item | |
17572 | It has been proven in practice (it is already on its second generation). | |
17573 | ||
17574 | @item | |
17575 | It will shorten development time (needless to say how important it is | |
17576 | now). | |
17577 | @end enumerate | |
17578 | ||
17579 | The original interface was designed to be used by Tcl code, so it was | |
17580 | slightly changed so it could be used through @sc{gdb/mi}. This section | |
17581 | describes the @sc{gdb/mi} operations that will be available and gives some | |
17582 | hints about their use. | |
17583 | ||
17584 | @emph{Note}: In addition to the set of operations described here, we | |
17585 | expect the @sc{gui} implementation of a variable window to require, at | |
17586 | least, the following operations: | |
17587 | ||
17588 | @itemize @bullet | |
17589 | @item @code{-gdb-show} @code{output-radix} | |
17590 | @item @code{-stack-list-arguments} | |
17591 | @item @code{-stack-list-locals} | |
17592 | @item @code{-stack-select-frame} | |
17593 | @end itemize | |
17594 | ||
17595 | @subheading Introduction to Variable Objects in @sc{gdb/mi} | |
17596 | ||
17597 | @cindex variable objects in @sc{gdb/mi} | |
17598 | The basic idea behind variable objects is the creation of a named object | |
17599 | to represent a variable, an expression, a memory location or even a CPU | |
17600 | register. For each object created, a set of operations is available for | |
17601 | examining or changing its properties. | |
17602 | ||
17603 | Furthermore, complex data types, such as C structures, are represented | |
17604 | in a tree format. For instance, the @code{struct} type variable is the | |
17605 | root and the children will represent the struct members. If a child | |
17606 | is itself of a complex type, it will also have children of its own. | |
17607 | Appropriate language differences are handled for C, C@t{++} and Java. | |
17608 | ||
17609 | When returning the actual values of the objects, this facility allows | |
17610 | for the individual selection of the display format used in the result | |
17611 | creation. It can be chosen among: binary, decimal, hexadecimal, octal | |
17612 | and natural. Natural refers to a default format automatically | |
17613 | chosen based on the variable type (like decimal for an @code{int}, hex | |
17614 | for pointers, etc.). | |
17615 | ||
17616 | The following is the complete set of @sc{gdb/mi} operations defined to | |
17617 | access this functionality: | |
17618 | ||
17619 | @multitable @columnfractions .4 .6 | |
17620 | @item @strong{Operation} | |
17621 | @tab @strong{Description} | |
17622 | ||
17623 | @item @code{-var-create} | |
17624 | @tab create a variable object | |
17625 | @item @code{-var-delete} | |
17626 | @tab delete the variable object and its children | |
17627 | @item @code{-var-set-format} | |
17628 | @tab set the display format of this variable | |
17629 | @item @code{-var-show-format} | |
17630 | @tab show the display format of this variable | |
17631 | @item @code{-var-info-num-children} | |
17632 | @tab tells how many children this object has | |
17633 | @item @code{-var-list-children} | |
17634 | @tab return a list of the object's children | |
17635 | @item @code{-var-info-type} | |
17636 | @tab show the type of this variable object | |
17637 | @item @code{-var-info-expression} | |
17638 | @tab print what this variable object represents | |
17639 | @item @code{-var-show-attributes} | |
17640 | @tab is this variable editable? does it exist here? | |
17641 | @item @code{-var-evaluate-expression} | |
17642 | @tab get the value of this variable | |
17643 | @item @code{-var-assign} | |
17644 | @tab set the value of this variable | |
17645 | @item @code{-var-update} | |
17646 | @tab update the variable and its children | |
17647 | @end multitable | |
17648 | ||
17649 | In the next subsection we describe each operation in detail and suggest | |
17650 | how it can be used. | |
17651 | ||
17652 | @subheading Description And Use of Operations on Variable Objects | |
17653 | ||
17654 | @subheading The @code{-var-create} Command | |
17655 | @findex -var-create | |
17656 | ||
17657 | @subsubheading Synopsis | |
17658 | ||
17659 | @smallexample | |
17660 | -var-create @{@var{name} | "-"@} | |
17661 | @{@var{frame-addr} | "*"@} @var{expression} | |
17662 | @end smallexample | |
17663 | ||
17664 | This operation creates a variable object, which allows the monitoring of | |
17665 | a variable, the result of an expression, a memory cell or a CPU | |
17666 | register. | |
17667 | ||
17668 | The @var{name} parameter is the string by which the object can be | |
17669 | referenced. It must be unique. If @samp{-} is specified, the varobj | |
17670 | system will generate a string ``varNNNNNN'' automatically. It will be | |
17671 | unique provided that one does not specify @var{name} on that format. | |
17672 | The command fails if a duplicate name is found. | |
17673 | ||
17674 | The frame under which the expression should be evaluated can be | |
17675 | specified by @var{frame-addr}. A @samp{*} indicates that the current | |
17676 | frame should be used. | |
17677 | ||
17678 | @var{expression} is any expression valid on the current language set (must not | |
17679 | begin with a @samp{*}), or one of the following: | |
17680 | ||
17681 | @itemize @bullet | |
17682 | @item | |
17683 | @samp{*@var{addr}}, where @var{addr} is the address of a memory cell | |
17684 | ||
17685 | @item | |
17686 | @samp{*@var{addr}-@var{addr}} --- a memory address range (TBD) | |
17687 | ||
17688 | @item | |
17689 | @samp{$@var{regname}} --- a CPU register name | |
17690 | @end itemize | |
17691 | ||
17692 | @subsubheading Result | |
17693 | ||
17694 | This operation returns the name, number of children and the type of the | |
17695 | object created. Type is returned as a string as the ones generated by | |
17696 | the @value{GDBN} CLI: | |
17697 | ||
17698 | @smallexample | |
17699 | name="@var{name}",numchild="N",type="@var{type}" | |
17700 | @end smallexample | |
17701 | ||
17702 | ||
17703 | @subheading The @code{-var-delete} Command | |
17704 | @findex -var-delete | |
17705 | ||
17706 | @subsubheading Synopsis | |
17707 | ||
17708 | @smallexample | |
17709 | -var-delete @var{name} | |
17710 | @end smallexample | |
17711 | ||
17712 | Deletes a previously created variable object and all of its children. | |
17713 | ||
17714 | Returns an error if the object @var{name} is not found. | |
17715 | ||
17716 | ||
17717 | @subheading The @code{-var-set-format} Command | |
17718 | @findex -var-set-format | |
17719 | ||
17720 | @subsubheading Synopsis | |
17721 | ||
17722 | @smallexample | |
17723 | -var-set-format @var{name} @var{format-spec} | |
17724 | @end smallexample | |
17725 | ||
17726 | Sets the output format for the value of the object @var{name} to be | |
17727 | @var{format-spec}. | |
17728 | ||
17729 | The syntax for the @var{format-spec} is as follows: | |
17730 | ||
17731 | @smallexample | |
17732 | @var{format-spec} @expansion{} | |
17733 | @{binary | decimal | hexadecimal | octal | natural@} | |
17734 | @end smallexample | |
17735 | ||
17736 | ||
17737 | @subheading The @code{-var-show-format} Command | |
17738 | @findex -var-show-format | |
17739 | ||
17740 | @subsubheading Synopsis | |
17741 | ||
17742 | @smallexample | |
17743 | -var-show-format @var{name} | |
17744 | @end smallexample | |
17745 | ||
17746 | Returns the format used to display the value of the object @var{name}. | |
17747 | ||
17748 | @smallexample | |
17749 | @var{format} @expansion{} | |
17750 | @var{format-spec} | |
17751 | @end smallexample | |
17752 | ||
17753 | ||
17754 | @subheading The @code{-var-info-num-children} Command | |
17755 | @findex -var-info-num-children | |
17756 | ||
17757 | @subsubheading Synopsis | |
17758 | ||
17759 | @smallexample | |
17760 | -var-info-num-children @var{name} | |
17761 | @end smallexample | |
17762 | ||
17763 | Returns the number of children of a variable object @var{name}: | |
17764 | ||
17765 | @smallexample | |
17766 | numchild=@var{n} | |
17767 | @end smallexample | |
17768 | ||
17769 | ||
17770 | @subheading The @code{-var-list-children} Command | |
17771 | @findex -var-list-children | |
17772 | ||
17773 | @subsubheading Synopsis | |
17774 | ||
17775 | @smallexample | |
17776 | -var-list-children @var{name} | |
17777 | @end smallexample | |
17778 | ||
17779 | Returns a list of the children of the specified variable object: | |
17780 | ||
17781 | @smallexample | |
17782 | numchild=@var{n},children=[@{name=@var{name}, | |
17783 | numchild=@var{n},type=@var{type}@},@r{(repeats N times)}] | |
17784 | @end smallexample | |
17785 | ||
17786 | ||
17787 | @subheading The @code{-var-info-type} Command | |
17788 | @findex -var-info-type | |
17789 | ||
17790 | @subsubheading Synopsis | |
17791 | ||
17792 | @smallexample | |
17793 | -var-info-type @var{name} | |
17794 | @end smallexample | |
17795 | ||
17796 | Returns the type of the specified variable @var{name}. The type is | |
17797 | returned as a string in the same format as it is output by the | |
17798 | @value{GDBN} CLI: | |
17799 | ||
17800 | @smallexample | |
17801 | type=@var{typename} | |
17802 | @end smallexample | |
17803 | ||
17804 | ||
17805 | @subheading The @code{-var-info-expression} Command | |
17806 | @findex -var-info-expression | |
17807 | ||
17808 | @subsubheading Synopsis | |
17809 | ||
17810 | @smallexample | |
17811 | -var-info-expression @var{name} | |
17812 | @end smallexample | |
17813 | ||
17814 | Returns what is represented by the variable object @var{name}: | |
17815 | ||
17816 | @smallexample | |
17817 | lang=@var{lang-spec},exp=@var{expression} | |
17818 | @end smallexample | |
17819 | ||
17820 | @noindent | |
17821 | where @var{lang-spec} is @code{@{"C" | "C++" | "Java"@}}. | |
17822 | ||
17823 | @subheading The @code{-var-show-attributes} Command | |
17824 | @findex -var-show-attributes | |
17825 | ||
17826 | @subsubheading Synopsis | |
17827 | ||
17828 | @smallexample | |
17829 | -var-show-attributes @var{name} | |
17830 | @end smallexample | |
17831 | ||
17832 | List attributes of the specified variable object @var{name}: | |
17833 | ||
17834 | @smallexample | |
17835 | status=@var{attr} [ ( ,@var{attr} )* ] | |
17836 | @end smallexample | |
17837 | ||
17838 | @noindent | |
17839 | where @var{attr} is @code{@{ @{ editable | noneditable @} | TBD @}}. | |
17840 | ||
17841 | @subheading The @code{-var-evaluate-expression} Command | |
17842 | @findex -var-evaluate-expression | |
17843 | ||
17844 | @subsubheading Synopsis | |
17845 | ||
17846 | @smallexample | |
17847 | -var-evaluate-expression @var{name} | |
17848 | @end smallexample | |
17849 | ||
17850 | Evaluates the expression that is represented by the specified variable | |
17851 | object and returns its value as a string in the current format specified | |
17852 | for the object: | |
17853 | ||
17854 | @smallexample | |
17855 | value=@var{value} | |
17856 | @end smallexample | |
17857 | ||
17858 | Note that one must invoke @code{-var-list-children} for a variable | |
17859 | before the value of a child variable can be evaluated. | |
17860 | ||
17861 | @subheading The @code{-var-assign} Command | |
17862 | @findex -var-assign | |
17863 | ||
17864 | @subsubheading Synopsis | |
17865 | ||
17866 | @smallexample | |
17867 | -var-assign @var{name} @var{expression} | |
17868 | @end smallexample | |
17869 | ||
17870 | Assigns the value of @var{expression} to the variable object specified | |
17871 | by @var{name}. The object must be @samp{editable}. If the variable's | |
17872 | value is altered by the assign, the variable will show up in any | |
17873 | subsequent @code{-var-update} list. | |
17874 | ||
17875 | @subsubheading Example | |
17876 | ||
17877 | @smallexample | |
17878 | (@value{GDBP}) | |
17879 | -var-assign var1 3 | |
17880 | ^done,value="3" | |
17881 | (@value{GDBP}) | |
17882 | -var-update * | |
17883 | ^done,changelist=[@{name="var1",in_scope="true",type_changed="false"@}] | |
17884 | (@value{GDBP}) | |
17885 | @end smallexample | |
17886 | ||
17887 | @subheading The @code{-var-update} Command | |
17888 | @findex -var-update | |
17889 | ||
17890 | @subsubheading Synopsis | |
17891 | ||
17892 | @smallexample | |
17893 | -var-update @{@var{name} | "*"@} | |
17894 | @end smallexample | |
17895 | ||
17896 | Update the value of the variable object @var{name} by evaluating its | |
17897 | expression after fetching all the new values from memory or registers. | |
17898 | A @samp{*} causes all existing variable objects to be updated. | |
17899 | ||
17900 | ||
17901 | @node Annotations | |
17902 | @chapter @value{GDBN} Annotations | |
17903 | ||
17904 | This chapter describes annotations in @value{GDBN}. Annotations are | |
17905 | designed to interface @value{GDBN} to graphical user interfaces or | |
17906 | other similar programs which want to interact with @value{GDBN} at a | |
17907 | relatively high level. | |
17908 | ||
17909 | @ignore | |
17910 | This is Edition @value{EDITION}, @value{DATE}. | |
17911 | @end ignore | |
17912 | ||
17913 | @menu | |
17914 | * Annotations Overview:: What annotations are; the general syntax. | |
17915 | * Server Prefix:: Issuing a command without affecting user state. | |
17916 | * Value Annotations:: Values are marked as such. | |
17917 | * Frame Annotations:: Stack frames are annotated. | |
17918 | * Displays:: @value{GDBN} can be told to display something periodically. | |
17919 | * Prompting:: Annotations marking @value{GDBN}'s need for input. | |
17920 | * Errors:: Annotations for error messages. | |
17921 | * Breakpoint Info:: Information on breakpoints. | |
17922 | * Invalidation:: Some annotations describe things now invalid. | |
17923 | * Annotations for Running:: | |
17924 | Whether the program is running, how it stopped, etc. | |
17925 | * Source Annotations:: Annotations describing source code. | |
17926 | * TODO:: Annotations which might be added in the future. | |
17927 | @end menu | |
17928 | ||
17929 | @node Annotations Overview | |
17930 | @section What is an Annotation? | |
17931 | @cindex annotations | |
17932 | ||
17933 | To produce annotations, start @value{GDBN} with the @code{--annotate=2} option. | |
17934 | ||
17935 | Annotations start with a newline character, two @samp{control-z} | |
17936 | characters, and the name of the annotation. If there is no additional | |
17937 | information associated with this annotation, the name of the annotation | |
17938 | is followed immediately by a newline. If there is additional | |
17939 | information, the name of the annotation is followed by a space, the | |
17940 | additional information, and a newline. The additional information | |
17941 | cannot contain newline characters. | |
17942 | ||
17943 | Any output not beginning with a newline and two @samp{control-z} | |
17944 | characters denotes literal output from @value{GDBN}. Currently there is | |
17945 | no need for @value{GDBN} to output a newline followed by two | |
17946 | @samp{control-z} characters, but if there was such a need, the | |
17947 | annotations could be extended with an @samp{escape} annotation which | |
17948 | means those three characters as output. | |
17949 | ||
17950 | A simple example of starting up @value{GDBN} with annotations is: | |
17951 | ||
17952 | @smallexample | |
17953 | $ gdb --annotate=2 | |
17954 | GNU GDB 5.0 | |
17955 | Copyright 2000 Free Software Foundation, Inc. | |
17956 | GDB is free software, covered by the GNU General Public License, | |
17957 | and you are welcome to change it and/or distribute copies of it | |
17958 | under certain conditions. | |
17959 | Type "show copying" to see the conditions. | |
17960 | There is absolutely no warranty for GDB. Type "show warranty" | |
17961 | for details. | |
17962 | This GDB was configured as "sparc-sun-sunos4.1.3" | |
17963 | ||
17964 | ^Z^Zpre-prompt | |
17965 | (gdb) | |
17966 | ^Z^Zprompt | |
17967 | quit | |
17968 | ||
17969 | ^Z^Zpost-prompt | |
17970 | $ | |
17971 | @end smallexample | |
17972 | ||
17973 | Here @samp{quit} is input to @value{GDBN}; the rest is output from | |
17974 | @value{GDBN}. The three lines beginning @samp{^Z^Z} (where @samp{^Z} | |
17975 | denotes a @samp{control-z} character) are annotations; the rest is | |
17976 | output from @value{GDBN}. | |
17977 | ||
17978 | @node Server Prefix | |
17979 | @section The Server Prefix | |
17980 | @cindex server prefix for annotations | |
17981 | ||
17982 | To issue a command to @value{GDBN} without affecting certain aspects of | |
17983 | the state which is seen by users, prefix it with @samp{server }. This | |
17984 | means that this command will not affect the command history, nor will it | |
17985 | affect @value{GDBN}'s notion of which command to repeat if @key{RET} is | |
17986 | pressed on a line by itself. | |
17987 | ||
17988 | The server prefix does not affect the recording of values into the value | |
17989 | history; to print a value without recording it into the value history, | |
17990 | use the @code{output} command instead of the @code{print} command. | |
17991 | ||
17992 | @node Value Annotations | |
17993 | @section Values | |
17994 | ||
17995 | @cindex annotations for values | |
17996 | When a value is printed in various contexts, @value{GDBN} uses | |
17997 | annotations to delimit the value from the surrounding text. | |
17998 | ||
17999 | @findex value-history-begin | |
18000 | @findex value-history-value | |
18001 | @findex value-history-end | |
18002 | If a value is printed using @code{print} and added to the value history, | |
18003 | the annotation looks like | |
18004 | ||
18005 | @smallexample | |
18006 | ^Z^Zvalue-history-begin @var{history-number} @var{value-flags} | |
18007 | @var{history-string} | |
18008 | ^Z^Zvalue-history-value | |
18009 | @var{the-value} | |
18010 | ^Z^Zvalue-history-end | |
18011 | @end smallexample | |
18012 | ||
18013 | @noindent | |
18014 | where @var{history-number} is the number it is getting in the value | |
18015 | history, @var{history-string} is a string, such as @samp{$5 = }, which | |
18016 | introduces the value to the user, @var{the-value} is the output | |
18017 | corresponding to the value itself, and @var{value-flags} is @samp{*} for | |
18018 | a value which can be dereferenced and @samp{-} for a value which cannot. | |
18019 | ||
18020 | @findex value-begin | |
18021 | @findex value-end | |
18022 | If the value is not added to the value history (it is an invalid float | |
18023 | or it is printed with the @code{output} command), the annotation is similar: | |
18024 | ||
18025 | @smallexample | |
18026 | ^Z^Zvalue-begin @var{value-flags} | |
18027 | @var{the-value} | |
18028 | ^Z^Zvalue-end | |
18029 | @end smallexample | |
18030 | ||
18031 | @findex arg-begin | |
18032 | @findex arg-name-end | |
18033 | @findex arg-value | |
18034 | @findex arg-end | |
18035 | When @value{GDBN} prints an argument to a function (for example, in the output | |
18036 | from the @code{backtrace} command), it annotates it as follows: | |
18037 | ||
18038 | @smallexample | |
18039 | ^Z^Zarg-begin | |
18040 | @var{argument-name} | |
18041 | ^Z^Zarg-name-end | |
18042 | @var{separator-string} | |
18043 | ^Z^Zarg-value @var{value-flags} | |
18044 | @var{the-value} | |
18045 | ^Z^Zarg-end | |
18046 | @end smallexample | |
18047 | ||
18048 | @noindent | |
18049 | where @var{argument-name} is the name of the argument, | |
18050 | @var{separator-string} is text which separates the name from the value | |
18051 | for the user's benefit (such as @samp{=}), and @var{value-flags} and | |
18052 | @var{the-value} have the same meanings as in a | |
18053 | @code{value-history-begin} annotation. | |
18054 | ||
18055 | @findex field-begin | |
18056 | @findex field-name-end | |
18057 | @findex field-value | |
18058 | @findex field-end | |
18059 | When printing a structure, @value{GDBN} annotates it as follows: | |
18060 | ||
18061 | @smallexample | |
18062 | ^Z^Zfield-begin @var{value-flags} | |
18063 | @var{field-name} | |
18064 | ^Z^Zfield-name-end | |
18065 | @var{separator-string} | |
18066 | ^Z^Zfield-value | |
18067 | @var{the-value} | |
18068 | ^Z^Zfield-end | |
18069 | @end smallexample | |
18070 | ||
18071 | @noindent | |
18072 | where @var{field-name} is the name of the field, @var{separator-string} | |
18073 | is text which separates the name from the value for the user's benefit | |
18074 | (such as @samp{=}), and @var{value-flags} and @var{the-value} have the | |
18075 | same meanings as in a @code{value-history-begin} annotation. | |
18076 | ||
18077 | When printing an array, @value{GDBN} annotates it as follows: | |
18078 | ||
18079 | @smallexample | |
18080 | ^Z^Zarray-section-begin @var{array-index} @var{value-flags} | |
18081 | @end smallexample | |
18082 | ||
18083 | @noindent | |
18084 | where @var{array-index} is the index of the first element being | |
18085 | annotated and @var{value-flags} has the same meaning as in a | |
18086 | @code{value-history-begin} annotation. This is followed by any number | |
18087 | of elements, where is element can be either a single element: | |
18088 | ||
18089 | @findex elt | |
18090 | @smallexample | |
18091 | @samp{,} @var{whitespace} ; @r{omitted for the first element} | |
18092 | @var{the-value} | |
18093 | ^Z^Zelt | |
18094 | @end smallexample | |
18095 | ||
18096 | or a repeated element | |
18097 | ||
18098 | @findex elt-rep | |
18099 | @findex elt-rep-end | |
18100 | @smallexample | |
18101 | @samp{,} @var{whitespace} ; @r{omitted for the first element} | |
18102 | @var{the-value} | |
18103 | ^Z^Zelt-rep @var{number-of-repetitions} | |
18104 | @var{repetition-string} | |
18105 | ^Z^Zelt-rep-end | |
18106 | @end smallexample | |
18107 | ||
18108 | In both cases, @var{the-value} is the output for the value of the | |
18109 | element and @var{whitespace} can contain spaces, tabs, and newlines. In | |
18110 | the repeated case, @var{number-of-repetitions} is the number of | |
18111 | consecutive array elements which contain that value, and | |
18112 | @var{repetition-string} is a string which is designed to convey to the | |
18113 | user that repetition is being depicted. | |
18114 | ||
18115 | @findex array-section-end | |
18116 | Once all the array elements have been output, the array annotation is | |
18117 | ended with | |
18118 | ||
18119 | @smallexample | |
18120 | ^Z^Zarray-section-end | |
18121 | @end smallexample | |
18122 | ||
18123 | @node Frame Annotations | |
18124 | @section Frames | |
18125 | ||
18126 | @cindex annotations for frames | |
18127 | Whenever @value{GDBN} prints a frame, it annotates it. For example, this applies | |
18128 | to frames printed when @value{GDBN} stops, output from commands such as | |
18129 | @code{backtrace} or @code{up}, etc. | |
18130 | ||
18131 | @findex frame-begin | |
18132 | The frame annotation begins with | |
18133 | ||
18134 | @smallexample | |
18135 | ^Z^Zframe-begin @var{level} @var{address} | |
18136 | @var{level-string} | |
18137 | @end smallexample | |
18138 | ||
18139 | @noindent | |
18140 | where @var{level} is the number of the frame (0 is the innermost frame, | |
18141 | and other frames have positive numbers), @var{address} is the address of | |
18142 | the code executing in that frame, and @var{level-string} is a string | |
18143 | designed to convey the level to the user. @var{address} is in the form | |
18144 | @samp{0x} followed by one or more lowercase hex digits (note that this | |
18145 | does not depend on the language). The frame ends with | |
18146 | ||
18147 | @findex frame-end | |
18148 | @smallexample | |
18149 | ^Z^Zframe-end | |
18150 | @end smallexample | |
18151 | ||
18152 | Between these annotations is the main body of the frame, which can | |
18153 | consist of | |
18154 | ||
18155 | @itemize @bullet | |
18156 | @item | |
18157 | @findex function-call | |
18158 | @smallexample | |
18159 | ^Z^Zfunction-call | |
18160 | @var{function-call-string} | |
18161 | @end smallexample | |
18162 | ||
18163 | where @var{function-call-string} is text designed to convey to the user | |
18164 | that this frame is associated with a function call made by @value{GDBN} to a | |
18165 | function in the program being debugged. | |
18166 | ||
18167 | @item | |
18168 | @findex signal-handler-caller | |
18169 | @smallexample | |
18170 | ^Z^Zsignal-handler-caller | |
18171 | @var{signal-handler-caller-string} | |
18172 | @end smallexample | |
18173 | ||
18174 | where @var{signal-handler-caller-string} is text designed to convey to | |
18175 | the user that this frame is associated with whatever mechanism is used | |
18176 | by this operating system to call a signal handler (it is the frame which | |
18177 | calls the signal handler, not the frame for the signal handler itself). | |
18178 | ||
18179 | @item | |
18180 | A normal frame. | |
18181 | ||
18182 | @findex frame-address | |
18183 | @findex frame-address-end | |
18184 | This can optionally (depending on whether this is thought of as | |
18185 | interesting information for the user to see) begin with | |
18186 | ||
18187 | @smallexample | |
18188 | ^Z^Zframe-address | |
18189 | @var{address} | |
18190 | ^Z^Zframe-address-end | |
18191 | @var{separator-string} | |
18192 | @end smallexample | |
18193 | ||
18194 | where @var{address} is the address executing in the frame (the same | |
18195 | address as in the @code{frame-begin} annotation, but printed in a form | |
18196 | which is intended for user consumption---in particular, the syntax varies | |
18197 | depending on the language), and @var{separator-string} is a string | |
18198 | intended to separate this address from what follows for the user's | |
18199 | benefit. | |
18200 | ||
18201 | @findex frame-function-name | |
18202 | @findex frame-args | |
18203 | Then comes | |
18204 | ||
18205 | @smallexample | |
18206 | ^Z^Zframe-function-name | |
18207 | @var{function-name} | |
18208 | ^Z^Zframe-args | |
18209 | @var{arguments} | |
18210 | @end smallexample | |
18211 | ||
18212 | where @var{function-name} is the name of the function executing in the | |
18213 | frame, or @samp{??} if not known, and @var{arguments} are the arguments | |
18214 | to the frame, with parentheses around them (each argument is annotated | |
18215 | individually as well, @pxref{Value Annotations}). | |
18216 | ||
18217 | @findex frame-source-begin | |
18218 | @findex frame-source-file | |
18219 | @findex frame-source-file-end | |
18220 | @findex frame-source-line | |
18221 | @findex frame-source-end | |
18222 | If source information is available, a reference to it is then printed: | |
18223 | ||
18224 | @smallexample | |
18225 | ^Z^Zframe-source-begin | |
18226 | @var{source-intro-string} | |
18227 | ^Z^Zframe-source-file | |
18228 | @var{filename} | |
18229 | ^Z^Zframe-source-file-end | |
18230 | : | |
18231 | ^Z^Zframe-source-line | |
18232 | @var{line-number} | |
18233 | ^Z^Zframe-source-end | |
18234 | @end smallexample | |
18235 | ||
18236 | where @var{source-intro-string} separates for the user's benefit the | |
18237 | reference from the text which precedes it, @var{filename} is the name of | |
18238 | the source file, and @var{line-number} is the line number within that | |
18239 | file (the first line is line 1). | |
18240 | ||
18241 | @findex frame-where | |
18242 | If @value{GDBN} prints some information about where the frame is from (which | |
18243 | library, which load segment, etc.; currently only done on the RS/6000), | |
18244 | it is annotated with | |
18245 | ||
18246 | @smallexample | |
18247 | ^Z^Zframe-where | |
18248 | @var{information} | |
18249 | @end smallexample | |
18250 | ||
18251 | Then, if source is to actually be displayed for this frame (for example, | |
18252 | this is not true for output from the @code{backtrace} command), then a | |
18253 | @code{source} annotation (@pxref{Source Annotations}) is displayed. Unlike | |
18254 | most annotations, this is output instead of the normal text which would be | |
18255 | output, not in addition. | |
18256 | @end itemize | |
18257 | ||
18258 | @node Displays | |
18259 | @section Displays | |
18260 | ||
18261 | @findex display-begin | |
18262 | @findex display-number-end | |
18263 | @findex display-format | |
18264 | @findex display-expression | |
18265 | @findex display-expression-end | |
18266 | @findex display-value | |
18267 | @findex display-end | |
18268 | @cindex annotations for display | |
18269 | When @value{GDBN} is told to display something using the @code{display} command, | |
18270 | the results of the display are annotated: | |
18271 | ||
18272 | @smallexample | |
18273 | ^Z^Zdisplay-begin | |
18274 | @var{number} | |
18275 | ^Z^Zdisplay-number-end | |
18276 | @var{number-separator} | |
18277 | ^Z^Zdisplay-format | |
18278 | @var{format} | |
18279 | ^Z^Zdisplay-expression | |
18280 | @var{expression} | |
18281 | ^Z^Zdisplay-expression-end | |
18282 | @var{expression-separator} | |
18283 | ^Z^Zdisplay-value | |
18284 | @var{value} | |
18285 | ^Z^Zdisplay-end | |
18286 | @end smallexample | |
18287 | ||
18288 | @noindent | |
18289 | where @var{number} is the number of the display, @var{number-separator} | |
18290 | is intended to separate the number from what follows for the user, | |
18291 | @var{format} includes information such as the size, format, or other | |
18292 | information about how the value is being displayed, @var{expression} is | |
18293 | the expression being displayed, @var{expression-separator} is intended | |
18294 | to separate the expression from the text that follows for the user, | |
18295 | and @var{value} is the actual value being displayed. | |
18296 | ||
18297 | @node Prompting | |
18298 | @section Annotation for @value{GDBN} Input | |
18299 | ||
18300 | @cindex annotations for prompts | |
18301 | When @value{GDBN} prompts for input, it annotates this fact so it is possible | |
18302 | to know when to send output, when the output from a given command is | |
18303 | over, etc. | |
18304 | ||
18305 | Different kinds of input each have a different @dfn{input type}. Each | |
18306 | input type has three annotations: a @code{pre-} annotation, which | |
18307 | denotes the beginning of any prompt which is being output, a plain | |
18308 | annotation, which denotes the end of the prompt, and then a @code{post-} | |
18309 | annotation which denotes the end of any echo which may (or may not) be | |
18310 | associated with the input. For example, the @code{prompt} input type | |
18311 | features the following annotations: | |
18312 | ||
18313 | @smallexample | |
18314 | ^Z^Zpre-prompt | |
18315 | ^Z^Zprompt | |
18316 | ^Z^Zpost-prompt | |
18317 | @end smallexample | |
18318 | ||
18319 | The input types are | |
18320 | ||
18321 | @table @code | |
18322 | @findex pre-prompt | |
18323 | @findex prompt | |
18324 | @findex post-prompt | |
18325 | @item prompt | |
18326 | When @value{GDBN} is prompting for a command (the main @value{GDBN} prompt). | |
18327 | ||
18328 | @findex pre-commands | |
18329 | @findex commands | |
18330 | @findex post-commands | |
18331 | @item commands | |
18332 | When @value{GDBN} prompts for a set of commands, like in the @code{commands} | |
18333 | command. The annotations are repeated for each command which is input. | |
18334 | ||
18335 | @findex pre-overload-choice | |
18336 | @findex overload-choice | |
18337 | @findex post-overload-choice | |
18338 | @item overload-choice | |
18339 | When @value{GDBN} wants the user to select between various overloaded functions. | |
18340 | ||
18341 | @findex pre-query | |
18342 | @findex query | |
18343 | @findex post-query | |
18344 | @item query | |
18345 | When @value{GDBN} wants the user to confirm a potentially dangerous operation. | |
18346 | ||
18347 | @findex pre-prompt-for-continue | |
18348 | @findex prompt-for-continue | |
18349 | @findex post-prompt-for-continue | |
18350 | @item prompt-for-continue | |
18351 | When @value{GDBN} is asking the user to press return to continue. Note: Don't | |
18352 | expect this to work well; instead use @code{set height 0} to disable | |
18353 | prompting. This is because the counting of lines is buggy in the | |
18354 | presence of annotations. | |
18355 | @end table | |
18356 | ||
18357 | @node Errors | |
18358 | @section Errors | |
18359 | @cindex annotations for errors, warnings and interrupts | |
18360 | ||
18361 | @findex quit | |
18362 | @smallexample | |
18363 | ^Z^Zquit | |
18364 | @end smallexample | |
18365 | ||
18366 | This annotation occurs right before @value{GDBN} responds to an interrupt. | |
18367 | ||
18368 | @findex error | |
18369 | @smallexample | |
18370 | ^Z^Zerror | |
18371 | @end smallexample | |
18372 | ||
18373 | This annotation occurs right before @value{GDBN} responds to an error. | |
18374 | ||
18375 | Quit and error annotations indicate that any annotations which @value{GDBN} was | |
18376 | in the middle of may end abruptly. For example, if a | |
18377 | @code{value-history-begin} annotation is followed by a @code{error}, one | |
18378 | cannot expect to receive the matching @code{value-history-end}. One | |
18379 | cannot expect not to receive it either, however; an error annotation | |
18380 | does not necessarily mean that @value{GDBN} is immediately returning all the way | |
18381 | to the top level. | |
18382 | ||
18383 | @findex error-begin | |
18384 | A quit or error annotation may be preceded by | |
18385 | ||
18386 | @smallexample | |
18387 | ^Z^Zerror-begin | |
18388 | @end smallexample | |
18389 | ||
18390 | Any output between that and the quit or error annotation is the error | |
18391 | message. | |
18392 | ||
18393 | Warning messages are not yet annotated. | |
18394 | @c If we want to change that, need to fix warning(), type_error(), | |
18395 | @c range_error(), and possibly other places. | |
18396 | ||
18397 | @node Breakpoint Info | |
18398 | @section Information on Breakpoints | |
18399 | ||
18400 | @cindex annotations for breakpoints | |
18401 | The output from the @code{info breakpoints} command is annotated as follows: | |
18402 | ||
18403 | @findex breakpoints-headers | |
18404 | @findex breakpoints-table | |
18405 | @smallexample | |
18406 | ^Z^Zbreakpoints-headers | |
18407 | @var{header-entry} | |
18408 | ^Z^Zbreakpoints-table | |
18409 | @end smallexample | |
18410 | ||
18411 | @noindent | |
18412 | where @var{header-entry} has the same syntax as an entry (see below) but | |
18413 | instead of containing data, it contains strings which are intended to | |
18414 | convey the meaning of each field to the user. This is followed by any | |
18415 | number of entries. If a field does not apply for this entry, it is | |
18416 | omitted. Fields may contain trailing whitespace. Each entry consists | |
18417 | of: | |
18418 | ||
18419 | @findex record | |
18420 | @findex field | |
18421 | @smallexample | |
18422 | ^Z^Zrecord | |
18423 | ^Z^Zfield 0 | |
18424 | @var{number} | |
18425 | ^Z^Zfield 1 | |
18426 | @var{type} | |
18427 | ^Z^Zfield 2 | |
18428 | @var{disposition} | |
18429 | ^Z^Zfield 3 | |
18430 | @var{enable} | |
18431 | ^Z^Zfield 4 | |
18432 | @var{address} | |
18433 | ^Z^Zfield 5 | |
18434 | @var{what} | |
18435 | ^Z^Zfield 6 | |
18436 | @var{frame} | |
18437 | ^Z^Zfield 7 | |
18438 | @var{condition} | |
18439 | ^Z^Zfield 8 | |
18440 | @var{ignore-count} | |
18441 | ^Z^Zfield 9 | |
18442 | @var{commands} | |
18443 | @end smallexample | |
18444 | ||
18445 | Note that @var{address} is intended for user consumption---the syntax | |
18446 | varies depending on the language. | |
18447 | ||
18448 | The output ends with | |
18449 | ||
18450 | @findex breakpoints-table-end | |
18451 | @smallexample | |
18452 | ^Z^Zbreakpoints-table-end | |
18453 | @end smallexample | |
18454 | ||
18455 | @node Invalidation | |
18456 | @section Invalidation Notices | |
18457 | ||
18458 | @cindex annotations for invalidation messages | |
18459 | The following annotations say that certain pieces of state may have | |
18460 | changed. | |
18461 | ||
18462 | @table @code | |
18463 | @findex frames-invalid | |
18464 | @item ^Z^Zframes-invalid | |
18465 | ||
18466 | The frames (for example, output from the @code{backtrace} command) may | |
18467 | have changed. | |
18468 | ||
18469 | @findex breakpoints-invalid | |
18470 | @item ^Z^Zbreakpoints-invalid | |
18471 | ||
18472 | The breakpoints may have changed. For example, the user just added or | |
18473 | deleted a breakpoint. | |
18474 | @end table | |
18475 | ||
18476 | @node Annotations for Running | |
18477 | @section Running the Program | |
18478 | @cindex annotations for running programs | |
18479 | ||
18480 | @findex starting | |
18481 | @findex stopping | |
18482 | When the program starts executing due to a @value{GDBN} command such as | |
18483 | @code{step} or @code{continue}, | |
18484 | ||
18485 | @smallexample | |
18486 | ^Z^Zstarting | |
18487 | @end smallexample | |
18488 | ||
18489 | is output. When the program stops, | |
18490 | ||
18491 | @smallexample | |
18492 | ^Z^Zstopped | |
18493 | @end smallexample | |
18494 | ||
18495 | is output. Before the @code{stopped} annotation, a variety of | |
18496 | annotations describe how the program stopped. | |
18497 | ||
18498 | @table @code | |
18499 | @findex exited | |
18500 | @item ^Z^Zexited @var{exit-status} | |
18501 | The program exited, and @var{exit-status} is the exit status (zero for | |
18502 | successful exit, otherwise nonzero). | |
18503 | ||
18504 | @findex signalled | |
18505 | @findex signal-name | |
18506 | @findex signal-name-end | |
18507 | @findex signal-string | |
18508 | @findex signal-string-end | |
18509 | @item ^Z^Zsignalled | |
18510 | The program exited with a signal. After the @code{^Z^Zsignalled}, the | |
18511 | annotation continues: | |
18512 | ||
18513 | @smallexample | |
18514 | @var{intro-text} | |
18515 | ^Z^Zsignal-name | |
18516 | @var{name} | |
18517 | ^Z^Zsignal-name-end | |
18518 | @var{middle-text} | |
18519 | ^Z^Zsignal-string | |
18520 | @var{string} | |
18521 | ^Z^Zsignal-string-end | |
18522 | @var{end-text} | |
18523 | @end smallexample | |
18524 | ||
18525 | @noindent | |
18526 | where @var{name} is the name of the signal, such as @code{SIGILL} or | |
18527 | @code{SIGSEGV}, and @var{string} is the explanation of the signal, such | |
18528 | as @code{Illegal Instruction} or @code{Segmentation fault}. | |
18529 | @var{intro-text}, @var{middle-text}, and @var{end-text} are for the | |
18530 | user's benefit and have no particular format. | |
18531 | ||
18532 | @findex signal | |
18533 | @item ^Z^Zsignal | |
18534 | The syntax of this annotation is just like @code{signalled}, but @value{GDBN} is | |
18535 | just saying that the program received the signal, not that it was | |
18536 | terminated with it. | |
18537 | ||
18538 | @findex breakpoint | |
18539 | @item ^Z^Zbreakpoint @var{number} | |
18540 | The program hit breakpoint number @var{number}. | |
18541 | ||
18542 | @findex watchpoint | |
18543 | @item ^Z^Zwatchpoint @var{number} | |
18544 | The program hit watchpoint number @var{number}. | |
18545 | @end table | |
18546 | ||
18547 | @node Source Annotations | |
18548 | @section Displaying Source | |
18549 | @cindex annotations for source display | |
18550 | ||
18551 | @findex source | |
18552 | The following annotation is used instead of displaying source code: | |
18553 | ||
18554 | @smallexample | |
18555 | ^Z^Zsource @var{filename}:@var{line}:@var{character}:@var{middle}:@var{addr} | |
18556 | @end smallexample | |
18557 | ||
18558 | where @var{filename} is an absolute file name indicating which source | |
18559 | file, @var{line} is the line number within that file (where 1 is the | |
18560 | first line in the file), @var{character} is the character position | |
18561 | within the file (where 0 is the first character in the file) (for most | |
18562 | debug formats this will necessarily point to the beginning of a line), | |
18563 | @var{middle} is @samp{middle} if @var{addr} is in the middle of the | |
18564 | line, or @samp{beg} if @var{addr} is at the beginning of the line, and | |
18565 | @var{addr} is the address in the target program associated with the | |
18566 | source which is being displayed. @var{addr} is in the form @samp{0x} | |
18567 | followed by one or more lowercase hex digits (note that this does not | |
18568 | depend on the language). | |
18569 | ||
18570 | @node TODO | |
18571 | @section Annotations We Might Want in the Future | |
18572 | ||
18573 | @format | |
18574 | - target-invalid | |
18575 | the target might have changed (registers, heap contents, or | |
18576 | execution status). For performance, we might eventually want | |
18577 | to hit `registers-invalid' and `all-registers-invalid' with | |
18578 | greater precision | |
18579 | ||
18580 | - systematic annotation for set/show parameters (including | |
18581 | invalidation notices). | |
18582 | ||
18583 | - similarly, `info' returns a list of candidates for invalidation | |
18584 | notices. | |
18585 | @end format | |
c906108c | 18586 | |
8e04817f AC |
18587 | @node GDB Bugs |
18588 | @chapter Reporting Bugs in @value{GDBN} | |
18589 | @cindex bugs in @value{GDBN} | |
18590 | @cindex reporting bugs in @value{GDBN} | |
c906108c | 18591 | |
8e04817f | 18592 | Your bug reports play an essential role in making @value{GDBN} reliable. |
c906108c | 18593 | |
8e04817f AC |
18594 | Reporting a bug may help you by bringing a solution to your problem, or it |
18595 | may not. But in any case the principal function of a bug report is to help | |
18596 | the entire community by making the next version of @value{GDBN} work better. Bug | |
18597 | reports are your contribution to the maintenance of @value{GDBN}. | |
c906108c | 18598 | |
8e04817f AC |
18599 | In order for a bug report to serve its purpose, you must include the |
18600 | information that enables us to fix the bug. | |
c4555f82 SC |
18601 | |
18602 | @menu | |
8e04817f AC |
18603 | * Bug Criteria:: Have you found a bug? |
18604 | * Bug Reporting:: How to report bugs | |
c4555f82 SC |
18605 | @end menu |
18606 | ||
8e04817f AC |
18607 | @node Bug Criteria |
18608 | @section Have you found a bug? | |
18609 | @cindex bug criteria | |
c4555f82 | 18610 | |
8e04817f | 18611 | If you are not sure whether you have found a bug, here are some guidelines: |
c4555f82 SC |
18612 | |
18613 | @itemize @bullet | |
8e04817f AC |
18614 | @cindex fatal signal |
18615 | @cindex debugger crash | |
18616 | @cindex crash of debugger | |
c4555f82 | 18617 | @item |
8e04817f AC |
18618 | If the debugger gets a fatal signal, for any input whatever, that is a |
18619 | @value{GDBN} bug. Reliable debuggers never crash. | |
18620 | ||
18621 | @cindex error on valid input | |
18622 | @item | |
18623 | If @value{GDBN} produces an error message for valid input, that is a | |
18624 | bug. (Note that if you're cross debugging, the problem may also be | |
18625 | somewhere in the connection to the target.) | |
c4555f82 | 18626 | |
8e04817f | 18627 | @cindex invalid input |
c4555f82 | 18628 | @item |
8e04817f AC |
18629 | If @value{GDBN} does not produce an error message for invalid input, |
18630 | that is a bug. However, you should note that your idea of | |
18631 | ``invalid input'' might be our idea of ``an extension'' or ``support | |
18632 | for traditional practice''. | |
18633 | ||
18634 | @item | |
18635 | If you are an experienced user of debugging tools, your suggestions | |
18636 | for improvement of @value{GDBN} are welcome in any case. | |
c4555f82 SC |
18637 | @end itemize |
18638 | ||
8e04817f AC |
18639 | @node Bug Reporting |
18640 | @section How to report bugs | |
18641 | @cindex bug reports | |
18642 | @cindex @value{GDBN} bugs, reporting | |
18643 | ||
18644 | A number of companies and individuals offer support for @sc{gnu} products. | |
18645 | If you obtained @value{GDBN} from a support organization, we recommend you | |
18646 | contact that organization first. | |
18647 | ||
18648 | You can find contact information for many support companies and | |
18649 | individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs | |
18650 | distribution. | |
18651 | @c should add a web page ref... | |
18652 | ||
129188f6 AC |
18653 | In any event, we also recommend that you submit bug reports for |
18654 | @value{GDBN}. The prefered method is to submit them directly using | |
18655 | @uref{http://www.gnu.org/software/gdb/bugs/, @value{GDBN}'s Bugs web | |
18656 | page}. Alternatively, the @email{bug-gdb@@gnu.org, e-mail gateway} can | |
18657 | be used. | |
8e04817f AC |
18658 | |
18659 | @strong{Do not send bug reports to @samp{info-gdb}, or to | |
18660 | @samp{help-gdb}, or to any newsgroups.} Most users of @value{GDBN} do | |
18661 | not want to receive bug reports. Those that do have arranged to receive | |
18662 | @samp{bug-gdb}. | |
18663 | ||
18664 | The mailing list @samp{bug-gdb} has a newsgroup @samp{gnu.gdb.bug} which | |
18665 | serves as a repeater. The mailing list and the newsgroup carry exactly | |
18666 | the same messages. Often people think of posting bug reports to the | |
18667 | newsgroup instead of mailing them. This appears to work, but it has one | |
18668 | problem which can be crucial: a newsgroup posting often lacks a mail | |
18669 | path back to the sender. Thus, if we need to ask for more information, | |
18670 | we may be unable to reach you. For this reason, it is better to send | |
18671 | bug reports to the mailing list. | |
c4555f82 | 18672 | |
8e04817f AC |
18673 | The fundamental principle of reporting bugs usefully is this: |
18674 | @strong{report all the facts}. If you are not sure whether to state a | |
18675 | fact or leave it out, state it! | |
c4555f82 | 18676 | |
8e04817f AC |
18677 | Often people omit facts because they think they know what causes the |
18678 | problem and assume that some details do not matter. Thus, you might | |
18679 | assume that the name of the variable you use in an example does not matter. | |
18680 | Well, probably it does not, but one cannot be sure. Perhaps the bug is a | |
18681 | stray memory reference which happens to fetch from the location where that | |
18682 | name is stored in memory; perhaps, if the name were different, the contents | |
18683 | of that location would fool the debugger into doing the right thing despite | |
18684 | the bug. Play it safe and give a specific, complete example. That is the | |
18685 | easiest thing for you to do, and the most helpful. | |
c4555f82 | 18686 | |
8e04817f AC |
18687 | Keep in mind that the purpose of a bug report is to enable us to fix the |
18688 | bug. It may be that the bug has been reported previously, but neither | |
18689 | you nor we can know that unless your bug report is complete and | |
18690 | self-contained. | |
c4555f82 | 18691 | |
8e04817f AC |
18692 | Sometimes people give a few sketchy facts and ask, ``Does this ring a |
18693 | bell?'' Those bug reports are useless, and we urge everyone to | |
18694 | @emph{refuse to respond to them} except to chide the sender to report | |
18695 | bugs properly. | |
18696 | ||
18697 | To enable us to fix the bug, you should include all these things: | |
c4555f82 SC |
18698 | |
18699 | @itemize @bullet | |
18700 | @item | |
8e04817f AC |
18701 | The version of @value{GDBN}. @value{GDBN} announces it if you start |
18702 | with no arguments; you can also print it at any time using @code{show | |
18703 | version}. | |
c4555f82 | 18704 | |
8e04817f AC |
18705 | Without this, we will not know whether there is any point in looking for |
18706 | the bug in the current version of @value{GDBN}. | |
c4555f82 SC |
18707 | |
18708 | @item | |
8e04817f AC |
18709 | The type of machine you are using, and the operating system name and |
18710 | version number. | |
c4555f82 SC |
18711 | |
18712 | @item | |
8e04817f AC |
18713 | What compiler (and its version) was used to compile @value{GDBN}---e.g. |
18714 | ``@value{GCC}--2.8.1''. | |
c4555f82 SC |
18715 | |
18716 | @item | |
8e04817f AC |
18717 | What compiler (and its version) was used to compile the program you are |
18718 | debugging---e.g. ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP | |
18719 | C Compiler''. For GCC, you can say @code{gcc --version} to get this | |
18720 | information; for other compilers, see the documentation for those | |
18721 | compilers. | |
c4555f82 | 18722 | |
8e04817f AC |
18723 | @item |
18724 | The command arguments you gave the compiler to compile your example and | |
18725 | observe the bug. For example, did you use @samp{-O}? To guarantee | |
18726 | you will not omit something important, list them all. A copy of the | |
18727 | Makefile (or the output from make) is sufficient. | |
c4555f82 | 18728 | |
8e04817f AC |
18729 | If we were to try to guess the arguments, we would probably guess wrong |
18730 | and then we might not encounter the bug. | |
c4555f82 | 18731 | |
8e04817f AC |
18732 | @item |
18733 | A complete input script, and all necessary source files, that will | |
18734 | reproduce the bug. | |
c4555f82 | 18735 | |
8e04817f AC |
18736 | @item |
18737 | A description of what behavior you observe that you believe is | |
18738 | incorrect. For example, ``It gets a fatal signal.'' | |
c4555f82 | 18739 | |
8e04817f AC |
18740 | Of course, if the bug is that @value{GDBN} gets a fatal signal, then we |
18741 | will certainly notice it. But if the bug is incorrect output, we might | |
18742 | not notice unless it is glaringly wrong. You might as well not give us | |
18743 | a chance to make a mistake. | |
c4555f82 | 18744 | |
8e04817f AC |
18745 | Even if the problem you experience is a fatal signal, you should still |
18746 | say so explicitly. Suppose something strange is going on, such as, your | |
18747 | copy of @value{GDBN} is out of synch, or you have encountered a bug in | |
18748 | the C library on your system. (This has happened!) Your copy might | |
18749 | crash and ours would not. If you told us to expect a crash, then when | |
18750 | ours fails to crash, we would know that the bug was not happening for | |
18751 | us. If you had not told us to expect a crash, then we would not be able | |
18752 | to draw any conclusion from our observations. | |
c4555f82 | 18753 | |
8e04817f AC |
18754 | @item |
18755 | If you wish to suggest changes to the @value{GDBN} source, send us context | |
18756 | diffs. If you even discuss something in the @value{GDBN} source, refer to | |
18757 | it by context, not by line number. | |
c4555f82 | 18758 | |
8e04817f AC |
18759 | The line numbers in our development sources will not match those in your |
18760 | sources. Your line numbers would convey no useful information to us. | |
c4555f82 | 18761 | |
8e04817f | 18762 | @end itemize |
c4555f82 | 18763 | |
8e04817f | 18764 | Here are some things that are not necessary: |
c4555f82 | 18765 | |
8e04817f AC |
18766 | @itemize @bullet |
18767 | @item | |
18768 | A description of the envelope of the bug. | |
c4555f82 | 18769 | |
8e04817f AC |
18770 | Often people who encounter a bug spend a lot of time investigating |
18771 | which changes to the input file will make the bug go away and which | |
18772 | changes will not affect it. | |
c4555f82 | 18773 | |
8e04817f AC |
18774 | This is often time consuming and not very useful, because the way we |
18775 | will find the bug is by running a single example under the debugger | |
18776 | with breakpoints, not by pure deduction from a series of examples. | |
18777 | We recommend that you save your time for something else. | |
c4555f82 | 18778 | |
8e04817f AC |
18779 | Of course, if you can find a simpler example to report @emph{instead} |
18780 | of the original one, that is a convenience for us. Errors in the | |
18781 | output will be easier to spot, running under the debugger will take | |
18782 | less time, and so on. | |
c4555f82 | 18783 | |
8e04817f AC |
18784 | However, simplification is not vital; if you do not want to do this, |
18785 | report the bug anyway and send us the entire test case you used. | |
c4555f82 | 18786 | |
8e04817f AC |
18787 | @item |
18788 | A patch for the bug. | |
c4555f82 | 18789 | |
8e04817f AC |
18790 | A patch for the bug does help us if it is a good one. But do not omit |
18791 | the necessary information, such as the test case, on the assumption that | |
18792 | a patch is all we need. We might see problems with your patch and decide | |
18793 | to fix the problem another way, or we might not understand it at all. | |
c4555f82 | 18794 | |
8e04817f AC |
18795 | Sometimes with a program as complicated as @value{GDBN} it is very hard to |
18796 | construct an example that will make the program follow a certain path | |
18797 | through the code. If you do not send us the example, we will not be able | |
18798 | to construct one, so we will not be able to verify that the bug is fixed. | |
c4555f82 | 18799 | |
8e04817f AC |
18800 | And if we cannot understand what bug you are trying to fix, or why your |
18801 | patch should be an improvement, we will not install it. A test case will | |
18802 | help us to understand. | |
c4555f82 | 18803 | |
8e04817f AC |
18804 | @item |
18805 | A guess about what the bug is or what it depends on. | |
c4555f82 | 18806 | |
8e04817f AC |
18807 | Such guesses are usually wrong. Even we cannot guess right about such |
18808 | things without first using the debugger to find the facts. | |
18809 | @end itemize | |
c4555f82 | 18810 | |
8e04817f AC |
18811 | @c The readline documentation is distributed with the readline code |
18812 | @c and consists of the two following files: | |
18813 | @c rluser.texinfo | |
18814 | @c inc-hist.texinfo | |
18815 | @c Use -I with makeinfo to point to the appropriate directory, | |
18816 | @c environment var TEXINPUTS with TeX. | |
18817 | @include rluser.texinfo | |
18818 | @include inc-hist.texinfo | |
c4555f82 | 18819 | |
c4555f82 | 18820 | |
8e04817f AC |
18821 | @node Formatting Documentation |
18822 | @appendix Formatting Documentation | |
c4555f82 | 18823 | |
8e04817f AC |
18824 | @cindex @value{GDBN} reference card |
18825 | @cindex reference card | |
18826 | The @value{GDBN} 4 release includes an already-formatted reference card, ready | |
18827 | for printing with PostScript or Ghostscript, in the @file{gdb} | |
18828 | subdirectory of the main source directory@footnote{In | |
18829 | @file{gdb-@value{GDBVN}/gdb/refcard.ps} of the version @value{GDBVN} | |
18830 | release.}. If you can use PostScript or Ghostscript with your printer, | |
18831 | you can print the reference card immediately with @file{refcard.ps}. | |
c4555f82 | 18832 | |
8e04817f AC |
18833 | The release also includes the source for the reference card. You |
18834 | can format it, using @TeX{}, by typing: | |
c4555f82 | 18835 | |
474c8240 | 18836 | @smallexample |
8e04817f | 18837 | make refcard.dvi |
474c8240 | 18838 | @end smallexample |
c4555f82 | 18839 | |
8e04817f AC |
18840 | The @value{GDBN} reference card is designed to print in @dfn{landscape} |
18841 | mode on US ``letter'' size paper; | |
18842 | that is, on a sheet 11 inches wide by 8.5 inches | |
18843 | high. You will need to specify this form of printing as an option to | |
18844 | your @sc{dvi} output program. | |
c4555f82 | 18845 | |
8e04817f | 18846 | @cindex documentation |
c4555f82 | 18847 | |
8e04817f AC |
18848 | All the documentation for @value{GDBN} comes as part of the machine-readable |
18849 | distribution. The documentation is written in Texinfo format, which is | |
18850 | a documentation system that uses a single source file to produce both | |
18851 | on-line information and a printed manual. You can use one of the Info | |
18852 | formatting commands to create the on-line version of the documentation | |
18853 | and @TeX{} (or @code{texi2roff}) to typeset the printed version. | |
c4555f82 | 18854 | |
8e04817f AC |
18855 | @value{GDBN} includes an already formatted copy of the on-line Info |
18856 | version of this manual in the @file{gdb} subdirectory. The main Info | |
18857 | file is @file{gdb-@value{GDBVN}/gdb/gdb.info}, and it refers to | |
18858 | subordinate files matching @samp{gdb.info*} in the same directory. If | |
18859 | necessary, you can print out these files, or read them with any editor; | |
18860 | but they are easier to read using the @code{info} subsystem in @sc{gnu} | |
18861 | Emacs or the standalone @code{info} program, available as part of the | |
18862 | @sc{gnu} Texinfo distribution. | |
c4555f82 | 18863 | |
8e04817f AC |
18864 | If you want to format these Info files yourself, you need one of the |
18865 | Info formatting programs, such as @code{texinfo-format-buffer} or | |
18866 | @code{makeinfo}. | |
c4555f82 | 18867 | |
8e04817f AC |
18868 | If you have @code{makeinfo} installed, and are in the top level |
18869 | @value{GDBN} source directory (@file{gdb-@value{GDBVN}}, in the case of | |
18870 | version @value{GDBVN}), you can make the Info file by typing: | |
c4555f82 | 18871 | |
474c8240 | 18872 | @smallexample |
8e04817f AC |
18873 | cd gdb |
18874 | make gdb.info | |
474c8240 | 18875 | @end smallexample |
c4555f82 | 18876 | |
8e04817f AC |
18877 | If you want to typeset and print copies of this manual, you need @TeX{}, |
18878 | a program to print its @sc{dvi} output files, and @file{texinfo.tex}, the | |
18879 | Texinfo definitions file. | |
c4555f82 | 18880 | |
8e04817f AC |
18881 | @TeX{} is a typesetting program; it does not print files directly, but |
18882 | produces output files called @sc{dvi} files. To print a typeset | |
18883 | document, you need a program to print @sc{dvi} files. If your system | |
18884 | has @TeX{} installed, chances are it has such a program. The precise | |
18885 | command to use depends on your system; @kbd{lpr -d} is common; another | |
18886 | (for PostScript devices) is @kbd{dvips}. The @sc{dvi} print command may | |
18887 | require a file name without any extension or a @samp{.dvi} extension. | |
c4555f82 | 18888 | |
8e04817f AC |
18889 | @TeX{} also requires a macro definitions file called |
18890 | @file{texinfo.tex}. This file tells @TeX{} how to typeset a document | |
18891 | written in Texinfo format. On its own, @TeX{} cannot either read or | |
18892 | typeset a Texinfo file. @file{texinfo.tex} is distributed with GDB | |
18893 | and is located in the @file{gdb-@var{version-number}/texinfo} | |
18894 | directory. | |
c4555f82 | 18895 | |
8e04817f AC |
18896 | If you have @TeX{} and a @sc{dvi} printer program installed, you can |
18897 | typeset and print this manual. First switch to the the @file{gdb} | |
18898 | subdirectory of the main source directory (for example, to | |
18899 | @file{gdb-@value{GDBVN}/gdb}) and type: | |
c4555f82 | 18900 | |
474c8240 | 18901 | @smallexample |
8e04817f | 18902 | make gdb.dvi |
474c8240 | 18903 | @end smallexample |
c4555f82 | 18904 | |
8e04817f | 18905 | Then give @file{gdb.dvi} to your @sc{dvi} printing program. |
c4555f82 | 18906 | |
8e04817f AC |
18907 | @node Installing GDB |
18908 | @appendix Installing @value{GDBN} | |
18909 | @cindex configuring @value{GDBN} | |
18910 | @cindex installation | |
94e91d6d | 18911 | @cindex configuring @value{GDBN}, and source tree subdirectories |
c4555f82 | 18912 | |
8e04817f AC |
18913 | @value{GDBN} comes with a @code{configure} script that automates the process |
18914 | of preparing @value{GDBN} for installation; you can then use @code{make} to | |
18915 | build the @code{gdb} program. | |
18916 | @iftex | |
18917 | @c irrelevant in info file; it's as current as the code it lives with. | |
18918 | @footnote{If you have a more recent version of @value{GDBN} than @value{GDBVN}, | |
18919 | look at the @file{README} file in the sources; we may have improved the | |
18920 | installation procedures since publishing this manual.} | |
18921 | @end iftex | |
c4555f82 | 18922 | |
8e04817f AC |
18923 | The @value{GDBN} distribution includes all the source code you need for |
18924 | @value{GDBN} in a single directory, whose name is usually composed by | |
18925 | appending the version number to @samp{gdb}. | |
c4555f82 | 18926 | |
8e04817f AC |
18927 | For example, the @value{GDBN} version @value{GDBVN} distribution is in the |
18928 | @file{gdb-@value{GDBVN}} directory. That directory contains: | |
c4555f82 | 18929 | |
8e04817f AC |
18930 | @table @code |
18931 | @item gdb-@value{GDBVN}/configure @r{(and supporting files)} | |
18932 | script for configuring @value{GDBN} and all its supporting libraries | |
c4555f82 | 18933 | |
8e04817f AC |
18934 | @item gdb-@value{GDBVN}/gdb |
18935 | the source specific to @value{GDBN} itself | |
c4555f82 | 18936 | |
8e04817f AC |
18937 | @item gdb-@value{GDBVN}/bfd |
18938 | source for the Binary File Descriptor library | |
c906108c | 18939 | |
8e04817f AC |
18940 | @item gdb-@value{GDBVN}/include |
18941 | @sc{gnu} include files | |
c906108c | 18942 | |
8e04817f AC |
18943 | @item gdb-@value{GDBVN}/libiberty |
18944 | source for the @samp{-liberty} free software library | |
c906108c | 18945 | |
8e04817f AC |
18946 | @item gdb-@value{GDBVN}/opcodes |
18947 | source for the library of opcode tables and disassemblers | |
c906108c | 18948 | |
8e04817f AC |
18949 | @item gdb-@value{GDBVN}/readline |
18950 | source for the @sc{gnu} command-line interface | |
c906108c | 18951 | |
8e04817f AC |
18952 | @item gdb-@value{GDBVN}/glob |
18953 | source for the @sc{gnu} filename pattern-matching subroutine | |
c906108c | 18954 | |
8e04817f AC |
18955 | @item gdb-@value{GDBVN}/mmalloc |
18956 | source for the @sc{gnu} memory-mapped malloc package | |
18957 | @end table | |
c906108c | 18958 | |
8e04817f AC |
18959 | The simplest way to configure and build @value{GDBN} is to run @code{configure} |
18960 | from the @file{gdb-@var{version-number}} source directory, which in | |
18961 | this example is the @file{gdb-@value{GDBVN}} directory. | |
c906108c | 18962 | |
8e04817f AC |
18963 | First switch to the @file{gdb-@var{version-number}} source directory |
18964 | if you are not already in it; then run @code{configure}. Pass the | |
18965 | identifier for the platform on which @value{GDBN} will run as an | |
18966 | argument. | |
c906108c | 18967 | |
8e04817f | 18968 | For example: |
c906108c | 18969 | |
474c8240 | 18970 | @smallexample |
8e04817f AC |
18971 | cd gdb-@value{GDBVN} |
18972 | ./configure @var{host} | |
18973 | make | |
474c8240 | 18974 | @end smallexample |
c906108c | 18975 | |
8e04817f AC |
18976 | @noindent |
18977 | where @var{host} is an identifier such as @samp{sun4} or | |
18978 | @samp{decstation}, that identifies the platform where @value{GDBN} will run. | |
18979 | (You can often leave off @var{host}; @code{configure} tries to guess the | |
18980 | correct value by examining your system.) | |
c906108c | 18981 | |
8e04817f AC |
18982 | Running @samp{configure @var{host}} and then running @code{make} builds the |
18983 | @file{bfd}, @file{readline}, @file{mmalloc}, and @file{libiberty} | |
18984 | libraries, then @code{gdb} itself. The configured source files, and the | |
18985 | binaries, are left in the corresponding source directories. | |
c906108c | 18986 | |
8e04817f AC |
18987 | @need 750 |
18988 | @code{configure} is a Bourne-shell (@code{/bin/sh}) script; if your | |
18989 | system does not recognize this automatically when you run a different | |
18990 | shell, you may need to run @code{sh} on it explicitly: | |
c906108c | 18991 | |
474c8240 | 18992 | @smallexample |
8e04817f | 18993 | sh configure @var{host} |
474c8240 | 18994 | @end smallexample |
c906108c | 18995 | |
8e04817f AC |
18996 | If you run @code{configure} from a directory that contains source |
18997 | directories for multiple libraries or programs, such as the | |
18998 | @file{gdb-@value{GDBVN}} source directory for version @value{GDBVN}, @code{configure} | |
18999 | creates configuration files for every directory level underneath (unless | |
19000 | you tell it not to, with the @samp{--norecursion} option). | |
19001 | ||
94e91d6d MC |
19002 | You should run the @code{configure} script from the top directory in the |
19003 | source tree, the @file{gdb-@var{version-number}} directory. If you run | |
19004 | @code{configure} from one of the subdirectories, you will configure only | |
19005 | that subdirectory. That is usually not what you want. In particular, | |
19006 | if you run the first @code{configure} from the @file{gdb} subdirectory | |
19007 | of the @file{gdb-@var{version-number}} directory, you will omit the | |
19008 | configuration of @file{bfd}, @file{readline}, and other sibling | |
19009 | directories of the @file{gdb} subdirectory. This leads to build errors | |
19010 | about missing include files such as @file{bfd/bfd.h}. | |
c906108c | 19011 | |
8e04817f AC |
19012 | You can install @code{@value{GDBP}} anywhere; it has no hardwired paths. |
19013 | However, you should make sure that the shell on your path (named by | |
19014 | the @samp{SHELL} environment variable) is publicly readable. Remember | |
19015 | that @value{GDBN} uses the shell to start your program---some systems refuse to | |
19016 | let @value{GDBN} debug child processes whose programs are not readable. | |
c906108c | 19017 | |
8e04817f AC |
19018 | @menu |
19019 | * Separate Objdir:: Compiling @value{GDBN} in another directory | |
19020 | * Config Names:: Specifying names for hosts and targets | |
19021 | * Configure Options:: Summary of options for configure | |
19022 | @end menu | |
c906108c | 19023 | |
8e04817f AC |
19024 | @node Separate Objdir |
19025 | @section Compiling @value{GDBN} in another directory | |
c906108c | 19026 | |
8e04817f AC |
19027 | If you want to run @value{GDBN} versions for several host or target machines, |
19028 | you need a different @code{gdb} compiled for each combination of | |
19029 | host and target. @code{configure} is designed to make this easy by | |
19030 | allowing you to generate each configuration in a separate subdirectory, | |
19031 | rather than in the source directory. If your @code{make} program | |
19032 | handles the @samp{VPATH} feature (@sc{gnu} @code{make} does), running | |
19033 | @code{make} in each of these directories builds the @code{gdb} | |
19034 | program specified there. | |
c906108c | 19035 | |
8e04817f AC |
19036 | To build @code{gdb} in a separate directory, run @code{configure} |
19037 | with the @samp{--srcdir} option to specify where to find the source. | |
19038 | (You also need to specify a path to find @code{configure} | |
19039 | itself from your working directory. If the path to @code{configure} | |
19040 | would be the same as the argument to @samp{--srcdir}, you can leave out | |
19041 | the @samp{--srcdir} option; it is assumed.) | |
c906108c | 19042 | |
8e04817f AC |
19043 | For example, with version @value{GDBVN}, you can build @value{GDBN} in a |
19044 | separate directory for a Sun 4 like this: | |
c906108c | 19045 | |
474c8240 | 19046 | @smallexample |
8e04817f AC |
19047 | @group |
19048 | cd gdb-@value{GDBVN} | |
19049 | mkdir ../gdb-sun4 | |
19050 | cd ../gdb-sun4 | |
19051 | ../gdb-@value{GDBVN}/configure sun4 | |
19052 | make | |
19053 | @end group | |
474c8240 | 19054 | @end smallexample |
c906108c | 19055 | |
8e04817f AC |
19056 | When @code{configure} builds a configuration using a remote source |
19057 | directory, it creates a tree for the binaries with the same structure | |
19058 | (and using the same names) as the tree under the source directory. In | |
19059 | the example, you'd find the Sun 4 library @file{libiberty.a} in the | |
19060 | directory @file{gdb-sun4/libiberty}, and @value{GDBN} itself in | |
19061 | @file{gdb-sun4/gdb}. | |
c906108c | 19062 | |
94e91d6d MC |
19063 | Make sure that your path to the @file{configure} script has just one |
19064 | instance of @file{gdb} in it. If your path to @file{configure} looks | |
19065 | like @file{../gdb-@value{GDBVN}/gdb/configure}, you are configuring only | |
19066 | one subdirectory of @value{GDBN}, not the whole package. This leads to | |
19067 | build errors about missing include files such as @file{bfd/bfd.h}. | |
19068 | ||
8e04817f AC |
19069 | One popular reason to build several @value{GDBN} configurations in separate |
19070 | directories is to configure @value{GDBN} for cross-compiling (where | |
19071 | @value{GDBN} runs on one machine---the @dfn{host}---while debugging | |
19072 | programs that run on another machine---the @dfn{target}). | |
19073 | You specify a cross-debugging target by | |
19074 | giving the @samp{--target=@var{target}} option to @code{configure}. | |
c906108c | 19075 | |
8e04817f AC |
19076 | When you run @code{make} to build a program or library, you must run |
19077 | it in a configured directory---whatever directory you were in when you | |
19078 | called @code{configure} (or one of its subdirectories). | |
c906108c | 19079 | |
8e04817f AC |
19080 | The @code{Makefile} that @code{configure} generates in each source |
19081 | directory also runs recursively. If you type @code{make} in a source | |
19082 | directory such as @file{gdb-@value{GDBVN}} (or in a separate configured | |
19083 | directory configured with @samp{--srcdir=@var{dirname}/gdb-@value{GDBVN}}), you | |
19084 | will build all the required libraries, and then build GDB. | |
c906108c | 19085 | |
8e04817f AC |
19086 | When you have multiple hosts or targets configured in separate |
19087 | directories, you can run @code{make} on them in parallel (for example, | |
19088 | if they are NFS-mounted on each of the hosts); they will not interfere | |
19089 | with each other. | |
c906108c | 19090 | |
8e04817f AC |
19091 | @node Config Names |
19092 | @section Specifying names for hosts and targets | |
c906108c | 19093 | |
8e04817f AC |
19094 | The specifications used for hosts and targets in the @code{configure} |
19095 | script are based on a three-part naming scheme, but some short predefined | |
19096 | aliases are also supported. The full naming scheme encodes three pieces | |
19097 | of information in the following pattern: | |
c906108c | 19098 | |
474c8240 | 19099 | @smallexample |
8e04817f | 19100 | @var{architecture}-@var{vendor}-@var{os} |
474c8240 | 19101 | @end smallexample |
c906108c | 19102 | |
8e04817f AC |
19103 | For example, you can use the alias @code{sun4} as a @var{host} argument, |
19104 | or as the value for @var{target} in a @code{--target=@var{target}} | |
19105 | option. The equivalent full name is @samp{sparc-sun-sunos4}. | |
c906108c | 19106 | |
8e04817f AC |
19107 | The @code{configure} script accompanying @value{GDBN} does not provide |
19108 | any query facility to list all supported host and target names or | |
19109 | aliases. @code{configure} calls the Bourne shell script | |
19110 | @code{config.sub} to map abbreviations to full names; you can read the | |
19111 | script, if you wish, or you can use it to test your guesses on | |
19112 | abbreviations---for example: | |
c906108c | 19113 | |
8e04817f AC |
19114 | @smallexample |
19115 | % sh config.sub i386-linux | |
19116 | i386-pc-linux-gnu | |
19117 | % sh config.sub alpha-linux | |
19118 | alpha-unknown-linux-gnu | |
19119 | % sh config.sub hp9k700 | |
19120 | hppa1.1-hp-hpux | |
19121 | % sh config.sub sun4 | |
19122 | sparc-sun-sunos4.1.1 | |
19123 | % sh config.sub sun3 | |
19124 | m68k-sun-sunos4.1.1 | |
19125 | % sh config.sub i986v | |
19126 | Invalid configuration `i986v': machine `i986v' not recognized | |
19127 | @end smallexample | |
c906108c | 19128 | |
8e04817f AC |
19129 | @noindent |
19130 | @code{config.sub} is also distributed in the @value{GDBN} source | |
19131 | directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}). | |
d700128c | 19132 | |
8e04817f AC |
19133 | @node Configure Options |
19134 | @section @code{configure} options | |
c906108c | 19135 | |
8e04817f AC |
19136 | Here is a summary of the @code{configure} options and arguments that |
19137 | are most often useful for building @value{GDBN}. @code{configure} also has | |
19138 | several other options not listed here. @inforef{What Configure | |
19139 | Does,,configure.info}, for a full explanation of @code{configure}. | |
c906108c | 19140 | |
474c8240 | 19141 | @smallexample |
8e04817f AC |
19142 | configure @r{[}--help@r{]} |
19143 | @r{[}--prefix=@var{dir}@r{]} | |
19144 | @r{[}--exec-prefix=@var{dir}@r{]} | |
19145 | @r{[}--srcdir=@var{dirname}@r{]} | |
19146 | @r{[}--norecursion@r{]} @r{[}--rm@r{]} | |
19147 | @r{[}--target=@var{target}@r{]} | |
19148 | @var{host} | |
474c8240 | 19149 | @end smallexample |
c906108c | 19150 | |
8e04817f AC |
19151 | @noindent |
19152 | You may introduce options with a single @samp{-} rather than | |
19153 | @samp{--} if you prefer; but you may abbreviate option names if you use | |
19154 | @samp{--}. | |
c906108c | 19155 | |
8e04817f AC |
19156 | @table @code |
19157 | @item --help | |
19158 | Display a quick summary of how to invoke @code{configure}. | |
c906108c | 19159 | |
8e04817f AC |
19160 | @item --prefix=@var{dir} |
19161 | Configure the source to install programs and files under directory | |
19162 | @file{@var{dir}}. | |
c906108c | 19163 | |
8e04817f AC |
19164 | @item --exec-prefix=@var{dir} |
19165 | Configure the source to install programs under directory | |
19166 | @file{@var{dir}}. | |
c906108c | 19167 | |
8e04817f AC |
19168 | @c avoid splitting the warning from the explanation: |
19169 | @need 2000 | |
19170 | @item --srcdir=@var{dirname} | |
19171 | @strong{Warning: using this option requires @sc{gnu} @code{make}, or another | |
19172 | @code{make} that implements the @code{VPATH} feature.}@* | |
19173 | Use this option to make configurations in directories separate from the | |
19174 | @value{GDBN} source directories. Among other things, you can use this to | |
19175 | build (or maintain) several configurations simultaneously, in separate | |
19176 | directories. @code{configure} writes configuration specific files in | |
19177 | the current directory, but arranges for them to use the source in the | |
19178 | directory @var{dirname}. @code{configure} creates directories under | |
19179 | the working directory in parallel to the source directories below | |
19180 | @var{dirname}. | |
c906108c | 19181 | |
8e04817f AC |
19182 | @item --norecursion |
19183 | Configure only the directory level where @code{configure} is executed; do not | |
19184 | propagate configuration to subdirectories. | |
c906108c | 19185 | |
8e04817f AC |
19186 | @item --target=@var{target} |
19187 | Configure @value{GDBN} for cross-debugging programs running on the specified | |
19188 | @var{target}. Without this option, @value{GDBN} is configured to debug | |
19189 | programs that run on the same machine (@var{host}) as @value{GDBN} itself. | |
c906108c | 19190 | |
8e04817f | 19191 | There is no convenient way to generate a list of all available targets. |
c906108c | 19192 | |
8e04817f AC |
19193 | @item @var{host} @dots{} |
19194 | Configure @value{GDBN} to run on the specified @var{host}. | |
c906108c | 19195 | |
8e04817f AC |
19196 | There is no convenient way to generate a list of all available hosts. |
19197 | @end table | |
c906108c | 19198 | |
8e04817f AC |
19199 | There are many other options available as well, but they are generally |
19200 | needed for special purposes only. | |
c906108c | 19201 | |
8e04817f AC |
19202 | @node Maintenance Commands |
19203 | @appendix Maintenance Commands | |
19204 | @cindex maintenance commands | |
19205 | @cindex internal commands | |
c906108c | 19206 | |
8e04817f AC |
19207 | In addition to commands intended for @value{GDBN} users, @value{GDBN} |
19208 | includes a number of commands intended for @value{GDBN} developers. | |
19209 | These commands are provided here for reference. | |
c906108c | 19210 | |
8e04817f AC |
19211 | @table @code |
19212 | @kindex maint info breakpoints | |
19213 | @item @anchor{maint info breakpoints}maint info breakpoints | |
19214 | Using the same format as @samp{info breakpoints}, display both the | |
19215 | breakpoints you've set explicitly, and those @value{GDBN} is using for | |
19216 | internal purposes. Internal breakpoints are shown with negative | |
19217 | breakpoint numbers. The type column identifies what kind of breakpoint | |
19218 | is shown: | |
c906108c | 19219 | |
8e04817f AC |
19220 | @table @code |
19221 | @item breakpoint | |
19222 | Normal, explicitly set breakpoint. | |
c906108c | 19223 | |
8e04817f AC |
19224 | @item watchpoint |
19225 | Normal, explicitly set watchpoint. | |
c906108c | 19226 | |
8e04817f AC |
19227 | @item longjmp |
19228 | Internal breakpoint, used to handle correctly stepping through | |
19229 | @code{longjmp} calls. | |
c906108c | 19230 | |
8e04817f AC |
19231 | @item longjmp resume |
19232 | Internal breakpoint at the target of a @code{longjmp}. | |
c906108c | 19233 | |
8e04817f AC |
19234 | @item until |
19235 | Temporary internal breakpoint used by the @value{GDBN} @code{until} command. | |
c906108c | 19236 | |
8e04817f AC |
19237 | @item finish |
19238 | Temporary internal breakpoint used by the @value{GDBN} @code{finish} command. | |
c906108c | 19239 | |
8e04817f AC |
19240 | @item shlib events |
19241 | Shared library events. | |
c906108c | 19242 | |
8e04817f | 19243 | @end table |
c906108c | 19244 | |
8d30a00d AC |
19245 | @kindex maint internal-error |
19246 | @kindex maint internal-warning | |
19247 | @item maint internal-error | |
19248 | @itemx maint internal-warning | |
19249 | Cause @value{GDBN} to call the internal function @code{internal_error} | |
19250 | or @code{internal_warning} and hence behave as though an internal error | |
19251 | or internal warning has been detected. In addition to reporting the | |
19252 | internal problem, these functions give the user the opportunity to | |
19253 | either quit @value{GDBN} or create a core file of the current | |
19254 | @value{GDBN} session. | |
19255 | ||
19256 | @smallexample | |
19257 | (gdb) @kbd{maint internal-error testing, 1, 2} | |
19258 | @dots{}/maint.c:121: internal-error: testing, 1, 2 | |
19259 | A problem internal to GDB has been detected. Further | |
19260 | debugging may prove unreliable. | |
19261 | Quit this debugging session? (y or n) @kbd{n} | |
19262 | Create a core file? (y or n) @kbd{n} | |
19263 | (gdb) | |
19264 | @end smallexample | |
19265 | ||
19266 | Takes an optional parameter that is used as the text of the error or | |
19267 | warning message. | |
19268 | ||
0680b120 AC |
19269 | @kindex maint print registers |
19270 | @kindex maint print raw-registers | |
19271 | @kindex maint print cooked-registers | |
617073a9 | 19272 | @kindex maint print register-groups |
0680b120 AC |
19273 | @item maint print registers |
19274 | @itemx maint print raw-registers | |
19275 | @itemx maint print cooked-registers | |
617073a9 | 19276 | @itemx maint print register-groups |
0680b120 AC |
19277 | Print @value{GDBN}'s internal register data structures. |
19278 | ||
617073a9 AC |
19279 | The command @code{maint print raw-registers} includes the contents of |
19280 | the raw register cache; the command @code{maint print cooked-registers} | |
19281 | includes the (cooked) value of all registers; and the command | |
19282 | @code{maint print register-groups} includes the groups that each | |
19283 | register is a member of. @xref{Registers,, Registers, gdbint, | |
19284 | @value{GDBN} Internals}. | |
0680b120 AC |
19285 | |
19286 | Takes an optional file parameter. | |
19287 | ||
617073a9 AC |
19288 | @kindex maint print reggroups |
19289 | @item maint print reggroups | |
19290 | Print @value{GDBN}'s internal register group data structures. | |
19291 | ||
19292 | Takes an optional file parameter. | |
19293 | ||
19294 | @smallexample | |
19295 | (gdb) @kbd{maint print reggroups} | |
19296 | Group Type | |
19297 | general user | |
19298 | float user | |
19299 | all user | |
19300 | vector user | |
19301 | system user | |
19302 | save internal | |
19303 | restore internal | |
19304 | @end smallexample | |
19305 | ||
e7ba9c65 DJ |
19306 | @kindex maint set profile |
19307 | @kindex maint show profile | |
19308 | @cindex profiling GDB | |
19309 | @item maint set profile | |
19310 | @itemx maint show profile | |
19311 | Control profiling of @value{GDBN}. | |
19312 | ||
19313 | Profiling will be disabled until you use the @samp{maint set profile} | |
19314 | command to enable it. When you enable profiling, the system will begin | |
19315 | collecting timing and execution count data; when you disable profiling or | |
19316 | exit @value{GDBN}, the results will be written to a log file. Remember that | |
19317 | if you use profiling, @value{GDBN} will overwrite the profiling log file | |
19318 | (often called @file{gmon.out}). If you have a record of important profiling | |
19319 | data in a @file{gmon.out} file, be sure to move it to a safe location. | |
19320 | ||
19321 | Configuring with @samp{--enable-profiling} arranges for @value{GDBN} to be | |
19322 | compiled with the @samp{-pg} compiler option. | |
19323 | ||
8e04817f | 19324 | @end table |
c906108c | 19325 | |
c906108c | 19326 | |
e0ce93ac | 19327 | @node Remote Protocol |
8e04817f | 19328 | @appendix @value{GDBN} Remote Serial Protocol |
c906108c | 19329 | |
ee2d5c50 AC |
19330 | @menu |
19331 | * Overview:: | |
19332 | * Packets:: | |
19333 | * Stop Reply Packets:: | |
19334 | * General Query Packets:: | |
19335 | * Register Packet Format:: | |
19336 | * Examples:: | |
0ce1b118 | 19337 | * File-I/O remote protocol extension:: |
ee2d5c50 AC |
19338 | @end menu |
19339 | ||
19340 | @node Overview | |
19341 | @section Overview | |
19342 | ||
8e04817f AC |
19343 | There may be occasions when you need to know something about the |
19344 | protocol---for example, if there is only one serial port to your target | |
19345 | machine, you might want your program to do something special if it | |
19346 | recognizes a packet meant for @value{GDBN}. | |
c906108c | 19347 | |
d2c6833e | 19348 | In the examples below, @samp{->} and @samp{<-} are used to indicate |
8e04817f | 19349 | transmitted and received data respectfully. |
c906108c | 19350 | |
8e04817f AC |
19351 | @cindex protocol, @value{GDBN} remote serial |
19352 | @cindex serial protocol, @value{GDBN} remote | |
19353 | @cindex remote serial protocol | |
19354 | All @value{GDBN} commands and responses (other than acknowledgments) are | |
19355 | sent as a @var{packet}. A @var{packet} is introduced with the character | |
19356 | @samp{$}, the actual @var{packet-data}, and the terminating character | |
19357 | @samp{#} followed by a two-digit @var{checksum}: | |
c906108c | 19358 | |
474c8240 | 19359 | @smallexample |
8e04817f | 19360 | @code{$}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 19361 | @end smallexample |
8e04817f | 19362 | @noindent |
c906108c | 19363 | |
8e04817f AC |
19364 | @cindex checksum, for @value{GDBN} remote |
19365 | @noindent | |
19366 | The two-digit @var{checksum} is computed as the modulo 256 sum of all | |
19367 | characters between the leading @samp{$} and the trailing @samp{#} (an | |
19368 | eight bit unsigned checksum). | |
c906108c | 19369 | |
8e04817f AC |
19370 | Implementors should note that prior to @value{GDBN} 5.0 the protocol |
19371 | specification also included an optional two-digit @var{sequence-id}: | |
c906108c | 19372 | |
474c8240 | 19373 | @smallexample |
8e04817f | 19374 | @code{$}@var{sequence-id}@code{:}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 19375 | @end smallexample |
c906108c | 19376 | |
8e04817f AC |
19377 | @cindex sequence-id, for @value{GDBN} remote |
19378 | @noindent | |
19379 | That @var{sequence-id} was appended to the acknowledgment. @value{GDBN} | |
19380 | has never output @var{sequence-id}s. Stubs that handle packets added | |
19381 | since @value{GDBN} 5.0 must not accept @var{sequence-id}. | |
c906108c | 19382 | |
8e04817f AC |
19383 | @cindex acknowledgment, for @value{GDBN} remote |
19384 | When either the host or the target machine receives a packet, the first | |
19385 | response expected is an acknowledgment: either @samp{+} (to indicate | |
19386 | the package was received correctly) or @samp{-} (to request | |
19387 | retransmission): | |
c906108c | 19388 | |
474c8240 | 19389 | @smallexample |
d2c6833e AC |
19390 | -> @code{$}@var{packet-data}@code{#}@var{checksum} |
19391 | <- @code{+} | |
474c8240 | 19392 | @end smallexample |
8e04817f | 19393 | @noindent |
53a5351d | 19394 | |
8e04817f AC |
19395 | The host (@value{GDBN}) sends @var{command}s, and the target (the |
19396 | debugging stub incorporated in your program) sends a @var{response}. In | |
19397 | the case of step and continue @var{command}s, the response is only sent | |
19398 | when the operation has completed (the target has again stopped). | |
c906108c | 19399 | |
8e04817f AC |
19400 | @var{packet-data} consists of a sequence of characters with the |
19401 | exception of @samp{#} and @samp{$} (see @samp{X} packet for additional | |
19402 | exceptions). | |
c906108c | 19403 | |
8e04817f | 19404 | Fields within the packet should be separated using @samp{,} @samp{;} or |
ee2d5c50 | 19405 | @cindex remote protocol, field separator |
8e04817f | 19406 | @samp{:}. Except where otherwise noted all numbers are represented in |
ee2d5c50 | 19407 | @sc{hex} with leading zeros suppressed. |
c906108c | 19408 | |
8e04817f AC |
19409 | Implementors should note that prior to @value{GDBN} 5.0, the character |
19410 | @samp{:} could not appear as the third character in a packet (as it | |
19411 | would potentially conflict with the @var{sequence-id}). | |
c906108c | 19412 | |
8e04817f AC |
19413 | Response @var{data} can be run-length encoded to save space. A @samp{*} |
19414 | means that the next character is an @sc{ascii} encoding giving a repeat count | |
19415 | which stands for that many repetitions of the character preceding the | |
19416 | @samp{*}. The encoding is @code{n+29}, yielding a printable character | |
19417 | where @code{n >=3} (which is where rle starts to win). The printable | |
19418 | characters @samp{$}, @samp{#}, @samp{+} and @samp{-} or with a numeric | |
19419 | value greater than 126 should not be used. | |
c906108c | 19420 | |
8e04817f AC |
19421 | Some remote systems have used a different run-length encoding mechanism |
19422 | loosely refered to as the cisco encoding. Following the @samp{*} | |
19423 | character are two hex digits that indicate the size of the packet. | |
c906108c | 19424 | |
8e04817f | 19425 | So: |
474c8240 | 19426 | @smallexample |
8e04817f | 19427 | "@code{0* }" |
474c8240 | 19428 | @end smallexample |
8e04817f AC |
19429 | @noindent |
19430 | means the same as "0000". | |
c906108c | 19431 | |
8e04817f AC |
19432 | The error response returned for some packets includes a two character |
19433 | error number. That number is not well defined. | |
c906108c | 19434 | |
8e04817f AC |
19435 | For any @var{command} not supported by the stub, an empty response |
19436 | (@samp{$#00}) should be returned. That way it is possible to extend the | |
19437 | protocol. A newer @value{GDBN} can tell if a packet is supported based | |
19438 | on that response. | |
c906108c | 19439 | |
8e04817f AC |
19440 | A stub is required to support the @samp{g}, @samp{G}, @samp{m}, @samp{M}, |
19441 | @samp{c}, and @samp{s} @var{command}s. All other @var{command}s are | |
19442 | optional. | |
c906108c | 19443 | |
ee2d5c50 AC |
19444 | @node Packets |
19445 | @section Packets | |
19446 | ||
19447 | The following table provides a complete list of all currently defined | |
19448 | @var{command}s and their corresponding response @var{data}. | |
19449 | ||
19450 | @table @r | |
19451 | ||
19452 | @item @code{!} --- extended mode | |
19453 | @cindex @code{!} packet | |
19454 | ||
8e04817f AC |
19455 | Enable extended mode. In extended mode, the remote server is made |
19456 | persistent. The @samp{R} packet is used to restart the program being | |
19457 | debugged. | |
ee2d5c50 AC |
19458 | |
19459 | Reply: | |
19460 | @table @samp | |
19461 | @item OK | |
8e04817f | 19462 | The remote target both supports and has enabled extended mode. |
ee2d5c50 | 19463 | @end table |
c906108c | 19464 | |
ee2d5c50 AC |
19465 | @item @code{?} --- last signal |
19466 | @cindex @code{?} packet | |
c906108c | 19467 | |
ee2d5c50 AC |
19468 | Indicate the reason the target halted. The reply is the same as for |
19469 | step and continue. | |
c906108c | 19470 | |
ee2d5c50 AC |
19471 | Reply: |
19472 | @xref{Stop Reply Packets}, for the reply specifications. | |
19473 | ||
19474 | @item @code{a} --- reserved | |
19475 | ||
19476 | Reserved for future use. | |
19477 | ||
19478 | @item @code{A}@var{arglen}@code{,}@var{argnum}@code{,}@var{arg}@code{,@dots{}} --- set program arguments @strong{(reserved)} | |
19479 | @cindex @code{A} packet | |
c906108c | 19480 | |
8e04817f AC |
19481 | Initialized @samp{argv[]} array passed into program. @var{arglen} |
19482 | specifies the number of bytes in the hex encoded byte stream @var{arg}. | |
ee2d5c50 AC |
19483 | See @code{gdbserver} for more details. |
19484 | ||
19485 | Reply: | |
19486 | @table @samp | |
19487 | @item OK | |
19488 | @item E@var{NN} | |
19489 | @end table | |
19490 | ||
19491 | @item @code{b}@var{baud} --- set baud @strong{(deprecated)} | |
19492 | @cindex @code{b} packet | |
19493 | ||
19494 | Change the serial line speed to @var{baud}. | |
19495 | ||
19496 | JTC: @emph{When does the transport layer state change? When it's | |
19497 | received, or after the ACK is transmitted. In either case, there are | |
19498 | problems if the command or the acknowledgment packet is dropped.} | |
19499 | ||
19500 | Stan: @emph{If people really wanted to add something like this, and get | |
19501 | it working for the first time, they ought to modify ser-unix.c to send | |
19502 | some kind of out-of-band message to a specially-setup stub and have the | |
19503 | switch happen "in between" packets, so that from remote protocol's point | |
19504 | of view, nothing actually happened.} | |
19505 | ||
19506 | @item @code{B}@var{addr},@var{mode} --- set breakpoint @strong{(deprecated)} | |
19507 | @cindex @code{B} packet | |
19508 | ||
8e04817f | 19509 | Set (@var{mode} is @samp{S}) or clear (@var{mode} is @samp{C}) a |
2f870471 AC |
19510 | breakpoint at @var{addr}. |
19511 | ||
19512 | This packet has been replaced by the @samp{Z} and @samp{z} packets | |
19513 | (@pxref{insert breakpoint or watchpoint packet}). | |
c906108c | 19514 | |
ee2d5c50 AC |
19515 | @item @code{c}@var{addr} --- continue |
19516 | @cindex @code{c} packet | |
19517 | ||
19518 | @var{addr} is address to resume. If @var{addr} is omitted, resume at | |
8e04817f | 19519 | current address. |
c906108c | 19520 | |
ee2d5c50 AC |
19521 | Reply: |
19522 | @xref{Stop Reply Packets}, for the reply specifications. | |
19523 | ||
19524 | @item @code{C}@var{sig}@code{;}@var{addr} --- continue with signal | |
19525 | @cindex @code{C} packet | |
19526 | ||
8e04817f AC |
19527 | Continue with signal @var{sig} (hex signal number). If |
19528 | @code{;}@var{addr} is omitted, resume at same address. | |
c906108c | 19529 | |
ee2d5c50 AC |
19530 | Reply: |
19531 | @xref{Stop Reply Packets}, for the reply specifications. | |
c906108c | 19532 | |
ee2d5c50 AC |
19533 | @item @code{d} --- toggle debug @strong{(deprecated)} |
19534 | @cindex @code{d} packet | |
19535 | ||
19536 | Toggle debug flag. | |
19537 | ||
19538 | @item @code{D} --- detach | |
19539 | @cindex @code{D} packet | |
19540 | ||
19541 | Detach @value{GDBN} from the remote system. Sent to the remote target | |
19542 | before @value{GDBN} disconnects. | |
19543 | ||
19544 | Reply: | |
19545 | @table @samp | |
19546 | @item @emph{no response} | |
8e04817f | 19547 | @value{GDBN} does not check for any response after sending this packet. |
ee2d5c50 | 19548 | @end table |
c906108c | 19549 | |
ee2d5c50 | 19550 | @item @code{e} --- reserved |
c906108c | 19551 | |
ee2d5c50 | 19552 | Reserved for future use. |
c906108c | 19553 | |
ee2d5c50 | 19554 | @item @code{E} --- reserved |
c906108c | 19555 | |
ee2d5c50 | 19556 | Reserved for future use. |
c906108c | 19557 | |
ee2d5c50 AC |
19558 | @item @code{f} --- reserved |
19559 | ||
19560 | Reserved for future use. | |
19561 | ||
0ce1b118 CV |
19562 | @item @code{F}@var{RC}@code{,}@var{EE}@code{,}@var{CF}@code{;}@var{XX} --- Reply to target's F packet. |
19563 | @cindex @code{F} packet | |
ee2d5c50 | 19564 | |
0ce1b118 CV |
19565 | This packet is send by @value{GDBN} as reply to a @code{F} request packet |
19566 | sent by the target. This is part of the File-I/O protocol extension. | |
19567 | @xref{File-I/O remote protocol extension}, for the specification. | |
ee2d5c50 AC |
19568 | |
19569 | @item @code{g} --- read registers | |
19570 | @anchor{read registers packet} | |
19571 | @cindex @code{g} packet | |
19572 | ||
19573 | Read general registers. | |
19574 | ||
19575 | Reply: | |
19576 | @table @samp | |
19577 | @item @var{XX@dots{}} | |
8e04817f AC |
19578 | Each byte of register data is described by two hex digits. The bytes |
19579 | with the register are transmitted in target byte order. The size of | |
19580 | each register and their position within the @samp{g} @var{packet} are | |
ee2d5c50 AC |
19581 | determined by the @value{GDBN} internal macros @var{REGISTER_RAW_SIZE} |
19582 | and @var{REGISTER_NAME} macros. The specification of several standard | |
8e04817f | 19583 | @code{g} packets is specified below. |
ee2d5c50 AC |
19584 | @item E@var{NN} |
19585 | for an error. | |
19586 | @end table | |
c906108c | 19587 | |
ee2d5c50 AC |
19588 | @item @code{G}@var{XX@dots{}} --- write regs |
19589 | @cindex @code{G} packet | |
c906108c | 19590 | |
ee2d5c50 AC |
19591 | @xref{read registers packet}, for a description of the @var{XX@dots{}} |
19592 | data. | |
19593 | ||
19594 | Reply: | |
19595 | @table @samp | |
19596 | @item OK | |
19597 | for success | |
19598 | @item E@var{NN} | |
19599 | for an error | |
19600 | @end table | |
19601 | ||
19602 | @item @code{h} --- reserved | |
19603 | ||
19604 | Reserved for future use. | |
19605 | ||
19606 | @item @code{H}@var{c}@var{t@dots{}} --- set thread | |
19607 | @cindex @code{H} packet | |
c906108c | 19608 | |
8e04817f | 19609 | Set thread for subsequent operations (@samp{m}, @samp{M}, @samp{g}, |
ee2d5c50 AC |
19610 | @samp{G}, et.al.). @var{c} depends on the operation to be performed: it |
19611 | should be @samp{c} for step and continue operations, @samp{g} for other | |
19612 | operations. The thread designator @var{t@dots{}} may be -1, meaning all | |
19613 | the threads, a thread number, or zero which means pick any thread. | |
19614 | ||
19615 | Reply: | |
19616 | @table @samp | |
19617 | @item OK | |
19618 | for success | |
19619 | @item E@var{NN} | |
19620 | for an error | |
19621 | @end table | |
c906108c | 19622 | |
8e04817f AC |
19623 | @c FIXME: JTC: |
19624 | @c 'H': How restrictive (or permissive) is the thread model. If a | |
19625 | @c thread is selected and stopped, are other threads allowed | |
19626 | @c to continue to execute? As I mentioned above, I think the | |
19627 | @c semantics of each command when a thread is selected must be | |
19628 | @c described. For example: | |
19629 | @c | |
19630 | @c 'g': If the stub supports threads and a specific thread is | |
19631 | @c selected, returns the register block from that thread; | |
19632 | @c otherwise returns current registers. | |
19633 | @c | |
19634 | @c 'G' If the stub supports threads and a specific thread is | |
19635 | @c selected, sets the registers of the register block of | |
19636 | @c that thread; otherwise sets current registers. | |
c906108c | 19637 | |
ee2d5c50 AC |
19638 | @item @code{i}@var{addr}@code{,}@var{nnn} --- cycle step @strong{(draft)} |
19639 | @anchor{cycle step packet} | |
19640 | @cindex @code{i} packet | |
19641 | ||
8e04817f AC |
19642 | Step the remote target by a single clock cycle. If @code{,}@var{nnn} is |
19643 | present, cycle step @var{nnn} cycles. If @var{addr} is present, cycle | |
19644 | step starting at that address. | |
c906108c | 19645 | |
ee2d5c50 AC |
19646 | @item @code{I} --- signal then cycle step @strong{(reserved)} |
19647 | @cindex @code{I} packet | |
19648 | ||
19649 | @xref{step with signal packet}. @xref{cycle step packet}. | |
19650 | ||
19651 | @item @code{j} --- reserved | |
19652 | ||
19653 | Reserved for future use. | |
19654 | ||
19655 | @item @code{J} --- reserved | |
c906108c | 19656 | |
ee2d5c50 | 19657 | Reserved for future use. |
c906108c | 19658 | |
ee2d5c50 AC |
19659 | @item @code{k} --- kill request |
19660 | @cindex @code{k} packet | |
c906108c | 19661 | |
ac282366 | 19662 | FIXME: @emph{There is no description of how to operate when a specific |
ee2d5c50 AC |
19663 | thread context has been selected (i.e.@: does 'k' kill only that |
19664 | thread?)}. | |
c906108c | 19665 | |
ee2d5c50 | 19666 | @item @code{K} --- reserved |
c906108c | 19667 | |
ee2d5c50 AC |
19668 | Reserved for future use. |
19669 | ||
19670 | @item @code{l} --- reserved | |
19671 | ||
19672 | Reserved for future use. | |
19673 | ||
19674 | @item @code{L} --- reserved | |
19675 | ||
19676 | Reserved for future use. | |
19677 | ||
19678 | @item @code{m}@var{addr}@code{,}@var{length} --- read memory | |
19679 | @cindex @code{m} packet | |
c906108c | 19680 | |
8e04817f | 19681 | Read @var{length} bytes of memory starting at address @var{addr}. |
ee2d5c50 | 19682 | Neither @value{GDBN} nor the stub assume that sized memory transfers are |
2e834e49 | 19683 | assumed using word aligned accesses. FIXME: @emph{A word aligned memory |
8e04817f | 19684 | transfer mechanism is needed.} |
c906108c | 19685 | |
ee2d5c50 AC |
19686 | Reply: |
19687 | @table @samp | |
19688 | @item @var{XX@dots{}} | |
19689 | @var{XX@dots{}} is mem contents. Can be fewer bytes than requested if able | |
19690 | to read only part of the data. Neither @value{GDBN} nor the stub assume | |
2e834e49 | 19691 | that sized memory transfers are assumed using word aligned |
ee2d5c50 AC |
19692 | accesses. FIXME: @emph{A word aligned memory transfer mechanism is |
19693 | needed.} | |
19694 | @item E@var{NN} | |
19695 | @var{NN} is errno | |
19696 | @end table | |
19697 | ||
19698 | @item @code{M}@var{addr},@var{length}@code{:}@var{XX@dots{}} --- write mem | |
19699 | @cindex @code{M} packet | |
19700 | ||
8e04817f | 19701 | Write @var{length} bytes of memory starting at address @var{addr}. |
ee2d5c50 AC |
19702 | @var{XX@dots{}} is the data. |
19703 | ||
19704 | Reply: | |
19705 | @table @samp | |
19706 | @item OK | |
19707 | for success | |
19708 | @item E@var{NN} | |
8e04817f AC |
19709 | for an error (this includes the case where only part of the data was |
19710 | written). | |
ee2d5c50 | 19711 | @end table |
c906108c | 19712 | |
ee2d5c50 | 19713 | @item @code{n} --- reserved |
c906108c | 19714 | |
ee2d5c50 | 19715 | Reserved for future use. |
c906108c | 19716 | |
ee2d5c50 | 19717 | @item @code{N} --- reserved |
c906108c | 19718 | |
ee2d5c50 | 19719 | Reserved for future use. |
c906108c | 19720 | |
ee2d5c50 AC |
19721 | @item @code{o} --- reserved |
19722 | ||
19723 | Reserved for future use. | |
19724 | ||
19725 | @item @code{O} --- reserved | |
19726 | ||
19727 | Reserved for future use. | |
c906108c | 19728 | |
ee2d5c50 AC |
19729 | @item @code{p}@var{n@dots{}} --- read reg @strong{(reserved)} |
19730 | @cindex @code{p} packet | |
19731 | ||
19732 | @xref{write register packet}. | |
19733 | ||
19734 | Reply: | |
19735 | @table @samp | |
19736 | @item @var{r@dots{}.} | |
19737 | The hex encoded value of the register in target byte order. | |
19738 | @end table | |
19739 | ||
19740 | @item @code{P}@var{n@dots{}}@code{=}@var{r@dots{}} --- write register | |
19741 | @anchor{write register packet} | |
19742 | @cindex @code{P} packet | |
19743 | ||
19744 | Write register @var{n@dots{}} with value @var{r@dots{}}, which contains two hex | |
8e04817f | 19745 | digits for each byte in the register (target byte order). |
c906108c | 19746 | |
ee2d5c50 AC |
19747 | Reply: |
19748 | @table @samp | |
19749 | @item OK | |
19750 | for success | |
19751 | @item E@var{NN} | |
19752 | for an error | |
19753 | @end table | |
19754 | ||
19755 | @item @code{q}@var{query} --- general query | |
19756 | @anchor{general query packet} | |
19757 | @cindex @code{q} packet | |
19758 | ||
19759 | Request info about @var{query}. In general @value{GDBN} queries have a | |
19760 | leading upper case letter. Custom vendor queries should use a company | |
19761 | prefix (in lower case) ex: @samp{qfsf.var}. @var{query} may optionally | |
19762 | be followed by a @samp{,} or @samp{;} separated list. Stubs must ensure | |
19763 | that they match the full @var{query} name. | |
19764 | ||
19765 | Reply: | |
19766 | @table @samp | |
19767 | @item @var{XX@dots{}} | |
19768 | Hex encoded data from query. The reply can not be empty. | |
19769 | @item E@var{NN} | |
19770 | error reply | |
8e04817f | 19771 | @item |
ee2d5c50 AC |
19772 | Indicating an unrecognized @var{query}. |
19773 | @end table | |
19774 | ||
19775 | @item @code{Q}@var{var}@code{=}@var{val} --- general set | |
19776 | @cindex @code{Q} packet | |
19777 | ||
19778 | Set value of @var{var} to @var{val}. | |
19779 | ||
19780 | @xref{general query packet}, for a discussion of naming conventions. | |
c906108c | 19781 | |
ee2d5c50 AC |
19782 | @item @code{r} --- reset @strong{(deprecated)} |
19783 | @cindex @code{r} packet | |
c906108c | 19784 | |
8e04817f | 19785 | Reset the entire system. |
c906108c | 19786 | |
ee2d5c50 AC |
19787 | @item @code{R}@var{XX} --- remote restart |
19788 | @cindex @code{R} packet | |
19789 | ||
8e04817f AC |
19790 | Restart the program being debugged. @var{XX}, while needed, is ignored. |
19791 | This packet is only available in extended mode. | |
ee2d5c50 AC |
19792 | |
19793 | Reply: | |
19794 | @table @samp | |
19795 | @item @emph{no reply} | |
8e04817f | 19796 | The @samp{R} packet has no reply. |
ee2d5c50 AC |
19797 | @end table |
19798 | ||
19799 | @item @code{s}@var{addr} --- step | |
19800 | @cindex @code{s} packet | |
c906108c | 19801 | |
8e04817f AC |
19802 | @var{addr} is address to resume. If @var{addr} is omitted, resume at |
19803 | same address. | |
c906108c | 19804 | |
ee2d5c50 AC |
19805 | Reply: |
19806 | @xref{Stop Reply Packets}, for the reply specifications. | |
19807 | ||
19808 | @item @code{S}@var{sig}@code{;}@var{addr} --- step with signal | |
19809 | @anchor{step with signal packet} | |
19810 | @cindex @code{S} packet | |
19811 | ||
8e04817f | 19812 | Like @samp{C} but step not continue. |
c906108c | 19813 | |
ee2d5c50 AC |
19814 | Reply: |
19815 | @xref{Stop Reply Packets}, for the reply specifications. | |
19816 | ||
19817 | @item @code{t}@var{addr}@code{:}@var{PP}@code{,}@var{MM} --- search | |
19818 | @cindex @code{t} packet | |
19819 | ||
8e04817f | 19820 | Search backwards starting at address @var{addr} for a match with pattern |
ee2d5c50 AC |
19821 | @var{PP} and mask @var{MM}. @var{PP} and @var{MM} are 4 bytes. |
19822 | @var{addr} must be at least 3 digits. | |
c906108c | 19823 | |
ee2d5c50 AC |
19824 | @item @code{T}@var{XX} --- thread alive |
19825 | @cindex @code{T} packet | |
c906108c | 19826 | |
ee2d5c50 | 19827 | Find out if the thread XX is alive. |
c906108c | 19828 | |
ee2d5c50 AC |
19829 | Reply: |
19830 | @table @samp | |
19831 | @item OK | |
19832 | thread is still alive | |
19833 | @item E@var{NN} | |
19834 | thread is dead | |
19835 | @end table | |
19836 | ||
19837 | @item @code{u} --- reserved | |
19838 | ||
19839 | Reserved for future use. | |
19840 | ||
19841 | @item @code{U} --- reserved | |
19842 | ||
19843 | Reserved for future use. | |
19844 | ||
19845 | @item @code{v} --- reserved | |
19846 | ||
19847 | Reserved for future use. | |
19848 | ||
19849 | @item @code{V} --- reserved | |
c906108c | 19850 | |
ee2d5c50 | 19851 | Reserved for future use. |
c906108c | 19852 | |
ee2d5c50 | 19853 | @item @code{w} --- reserved |
c906108c | 19854 | |
ee2d5c50 | 19855 | Reserved for future use. |
c906108c | 19856 | |
ee2d5c50 | 19857 | @item @code{W} --- reserved |
c906108c | 19858 | |
ee2d5c50 | 19859 | Reserved for future use. |
c906108c | 19860 | |
ee2d5c50 AC |
19861 | @item @code{x} --- reserved |
19862 | ||
19863 | Reserved for future use. | |
19864 | ||
19865 | @item @code{X}@var{addr}@code{,}@var{length}@var{:}@var{XX@dots{}} --- write mem (binary) | |
19866 | @cindex @code{X} packet | |
19867 | ||
19868 | @var{addr} is address, @var{length} is number of bytes, @var{XX@dots{}} | |
19869 | is binary data. The characters @code{$}, @code{#}, and @code{0x7d} are | |
8e04817f | 19870 | escaped using @code{0x7d}. |
c906108c | 19871 | |
ee2d5c50 AC |
19872 | Reply: |
19873 | @table @samp | |
19874 | @item OK | |
19875 | for success | |
19876 | @item E@var{NN} | |
19877 | for an error | |
19878 | @end table | |
19879 | ||
19880 | @item @code{y} --- reserved | |
c906108c | 19881 | |
ee2d5c50 | 19882 | Reserved for future use. |
c906108c | 19883 | |
ee2d5c50 AC |
19884 | @item @code{Y} reserved |
19885 | ||
19886 | Reserved for future use. | |
19887 | ||
2f870471 AC |
19888 | @item @code{z}@var{type}@code{,}@var{addr}@code{,}@var{length} --- remove breakpoint or watchpoint @strong{(draft)} |
19889 | @itemx @code{Z}@var{type}@code{,}@var{addr}@code{,}@var{length} --- insert breakpoint or watchpoint @strong{(draft)} | |
19890 | @anchor{insert breakpoint or watchpoint packet} | |
ee2d5c50 | 19891 | @cindex @code{z} packet |
2f870471 | 19892 | @cindex @code{Z} packets |
ee2d5c50 | 19893 | |
2f870471 AC |
19894 | Insert (@code{Z}) or remove (@code{z}) a @var{type} breakpoint or |
19895 | watchpoint starting at address @var{address} and covering the next | |
19896 | @var{length} bytes. | |
ee2d5c50 | 19897 | |
2f870471 AC |
19898 | Each breakpoint and watchpoint packet @var{type} is documented |
19899 | separately. | |
19900 | ||
512217c7 AC |
19901 | @emph{Implementation notes: A remote target shall return an empty string |
19902 | for an unrecognized breakpoint or watchpoint packet @var{type}. A | |
19903 | remote target shall support either both or neither of a given | |
2f870471 AC |
19904 | @code{Z}@var{type}@dots{} and @code{z}@var{type}@dots{} packet pair. To |
19905 | avoid potential problems with duplicate packets, the operations should | |
19906 | be implemented in an idempotent way.} | |
19907 | ||
19908 | @item @code{z}@code{0}@code{,}@var{addr}@code{,}@var{length} --- remove memory breakpoint @strong{(draft)} | |
19909 | @item @code{Z}@code{0}@code{,}@var{addr}@code{,}@var{length} --- insert memory breakpoint @strong{(draft)} | |
19910 | @cindex @code{z0} packet | |
19911 | @cindex @code{Z0} packet | |
19912 | ||
19913 | Insert (@code{Z0}) or remove (@code{z0}) a memory breakpoint at address | |
19914 | @code{addr} of size @code{length}. | |
19915 | ||
19916 | A memory breakpoint is implemented by replacing the instruction at | |
19917 | @var{addr} with a software breakpoint or trap instruction. The | |
19918 | @code{length} is used by targets that indicates the size of the | |
19919 | breakpoint (in bytes) that should be inserted (e.g., the @sc{arm} and | |
19920 | @sc{mips} can insert either a 2 or 4 byte breakpoint). | |
c906108c | 19921 | |
2f870471 AC |
19922 | @emph{Implementation note: It is possible for a target to copy or move |
19923 | code that contains memory breakpoints (e.g., when implementing | |
19924 | overlays). The behavior of this packet, in the presence of such a | |
19925 | target, is not defined.} | |
c906108c | 19926 | |
ee2d5c50 AC |
19927 | Reply: |
19928 | @table @samp | |
2f870471 AC |
19929 | @item OK |
19930 | success | |
19931 | @item | |
19932 | not supported | |
ee2d5c50 AC |
19933 | @item E@var{NN} |
19934 | for an error | |
2f870471 AC |
19935 | @end table |
19936 | ||
19937 | @item @code{z}@code{1}@code{,}@var{addr}@code{,}@var{length} --- remove hardware breakpoint @strong{(draft)} | |
19938 | @item @code{Z}@code{1}@code{,}@var{addr}@code{,}@var{length} --- insert hardware breakpoint @strong{(draft)} | |
19939 | @cindex @code{z1} packet | |
19940 | @cindex @code{Z1} packet | |
19941 | ||
19942 | Insert (@code{Z1}) or remove (@code{z1}) a hardware breakpoint at | |
19943 | address @code{addr} of size @code{length}. | |
19944 | ||
19945 | A hardware breakpoint is implemented using a mechanism that is not | |
19946 | dependant on being able to modify the target's memory. | |
19947 | ||
19948 | @emph{Implementation note: A hardware breakpoint is not affected by code | |
19949 | movement.} | |
19950 | ||
19951 | Reply: | |
19952 | @table @samp | |
ee2d5c50 | 19953 | @item OK |
2f870471 AC |
19954 | success |
19955 | @item | |
19956 | not supported | |
19957 | @item E@var{NN} | |
19958 | for an error | |
19959 | @end table | |
19960 | ||
19961 | @item @code{z}@code{2}@code{,}@var{addr}@code{,}@var{length} --- remove write watchpoint @strong{(draft)} | |
19962 | @item @code{Z}@code{2}@code{,}@var{addr}@code{,}@var{length} --- insert write watchpoint @strong{(draft)} | |
19963 | @cindex @code{z2} packet | |
19964 | @cindex @code{Z2} packet | |
19965 | ||
19966 | Insert (@code{Z2}) or remove (@code{z2}) a write watchpoint. | |
19967 | ||
19968 | Reply: | |
19969 | @table @samp | |
19970 | @item OK | |
19971 | success | |
19972 | @item | |
19973 | not supported | |
19974 | @item E@var{NN} | |
19975 | for an error | |
19976 | @end table | |
19977 | ||
19978 | @item @code{z}@code{3}@code{,}@var{addr}@code{,}@var{length} --- remove read watchpoint @strong{(draft)} | |
19979 | @item @code{Z}@code{3}@code{,}@var{addr}@code{,}@var{length} --- insert read watchpoint @strong{(draft)} | |
19980 | @cindex @code{z3} packet | |
19981 | @cindex @code{Z3} packet | |
19982 | ||
2e834e49 | 19983 | Insert (@code{Z3}) or remove (@code{z3}) a read watchpoint. |
2f870471 AC |
19984 | |
19985 | Reply: | |
19986 | @table @samp | |
19987 | @item OK | |
19988 | success | |
19989 | @item | |
19990 | not supported | |
19991 | @item E@var{NN} | |
19992 | for an error | |
19993 | @end table | |
19994 | ||
2e834e49 HPN |
19995 | @item @code{z}@code{4}@code{,}@var{addr}@code{,}@var{length} --- remove access watchpoint @strong{(draft)} |
19996 | @item @code{Z}@code{4}@code{,}@var{addr}@code{,}@var{length} --- insert access watchpoint @strong{(draft)} | |
2f870471 AC |
19997 | @cindex @code{z4} packet |
19998 | @cindex @code{Z4} packet | |
19999 | ||
20000 | Insert (@code{Z4}) or remove (@code{z4}) an access watchpoint. | |
20001 | ||
20002 | Reply: | |
20003 | @table @samp | |
20004 | @item OK | |
20005 | success | |
20006 | @item | |
20007 | not supported | |
20008 | @item E@var{NN} | |
20009 | for an error | |
ee2d5c50 AC |
20010 | @end table |
20011 | ||
20012 | @end table | |
c906108c | 20013 | |
ee2d5c50 AC |
20014 | @node Stop Reply Packets |
20015 | @section Stop Reply Packets | |
20016 | @cindex stop reply packets | |
c906108c | 20017 | |
8e04817f AC |
20018 | The @samp{C}, @samp{c}, @samp{S}, @samp{s} and @samp{?} packets can |
20019 | receive any of the below as a reply. In the case of the @samp{C}, | |
20020 | @samp{c}, @samp{S} and @samp{s} packets, that reply is only returned | |
20021 | when the target halts. In the below the exact meaning of @samp{signal | |
20022 | number} is poorly defined. In general one of the UNIX signal numbering | |
20023 | conventions is used. | |
c906108c | 20024 | |
ee2d5c50 | 20025 | @table @samp |
c906108c | 20026 | |
ee2d5c50 AC |
20027 | @item S@var{AA} |
20028 | @var{AA} is the signal number | |
c906108c | 20029 | |
8e04817f | 20030 | @item @code{T}@var{AA}@var{n...}@code{:}@var{r...}@code{;}@var{n...}@code{:}@var{r...}@code{;}@var{n...}@code{:}@var{r...}@code{;} |
ee2d5c50 AC |
20031 | @cindex @code{T} packet reply |
20032 | ||
8e04817f AC |
20033 | @var{AA} = two hex digit signal number; @var{n...} = register number |
20034 | (hex), @var{r...} = target byte ordered register contents, size defined | |
20035 | by @code{REGISTER_RAW_SIZE}; @var{n...} = @samp{thread}, @var{r...} = | |
3c3bea1c GS |
20036 | thread process ID, this is a hex integer; @var{n...} = (@samp{watch} | |
20037 | @samp{rwatch} | @samp{awatch}, @var{r...} = data address, this is a hex | |
20038 | integer; @var{n...} = other string not starting with valid hex digit. | |
20039 | @value{GDBN} should ignore this @var{n...}, @var{r...} pair and go on | |
20040 | to the next. This way we can extend the protocol. | |
c906108c | 20041 | |
ee2d5c50 AC |
20042 | @item W@var{AA} |
20043 | ||
8e04817f | 20044 | The process exited, and @var{AA} is the exit status. This is only |
ee2d5c50 AC |
20045 | applicable to certain targets. |
20046 | ||
20047 | @item X@var{AA} | |
c906108c | 20048 | |
8e04817f | 20049 | The process terminated with signal @var{AA}. |
c906108c | 20050 | |
ee2d5c50 AC |
20051 | @item N@var{AA};@var{t@dots{}};@var{d@dots{}};@var{b@dots{}} @strong{(obsolete)} |
20052 | ||
20053 | @var{AA} = signal number; @var{t@dots{}} = address of symbol | |
20054 | @code{_start}; @var{d@dots{}} = base of data section; @var{b@dots{}} = | |
20055 | base of bss section. @emph{Note: only used by Cisco Systems targets. | |
20056 | The difference between this reply and the @samp{qOffsets} query is that | |
20057 | the @samp{N} packet may arrive spontaneously whereas the @samp{qOffsets} | |
20058 | is a query initiated by the host debugger.} | |
c906108c | 20059 | |
ee2d5c50 | 20060 | @item O@var{XX@dots{}} |
c906108c | 20061 | |
ee2d5c50 AC |
20062 | @var{XX@dots{}} is hex encoding of @sc{ascii} data. This can happen at |
20063 | any time while the program is running and the debugger should continue | |
20064 | to wait for @samp{W}, @samp{T}, etc. | |
20065 | ||
0ce1b118 CV |
20066 | @item F@var{call-id}@code{,}@var{parameter@dots{}} |
20067 | ||
20068 | @var{call-id} is the identifier which says which host system call should | |
20069 | be called. This is just the name of the function. Translation into the | |
20070 | correct system call is only applicable as it's defined in @value{GDBN}. | |
20071 | @xref{File-I/O remote protocol extension}, for a list of implemented | |
20072 | system calls. | |
20073 | ||
20074 | @var{parameter@dots{}} is a list of parameters as defined for this very | |
20075 | system call. | |
20076 | ||
20077 | The target replies with this packet when it expects @value{GDBN} to call | |
20078 | a host system call on behalf of the target. @value{GDBN} replies with | |
20079 | an appropriate @code{F} packet and keeps up waiting for the next reply | |
20080 | packet from the target. The latest @samp{C}, @samp{c}, @samp{S} or | |
20081 | @samp{s} action is expected to be continued. | |
20082 | @xref{File-I/O remote protocol extension}, for more details. | |
20083 | ||
ee2d5c50 AC |
20084 | @end table |
20085 | ||
20086 | @node General Query Packets | |
20087 | @section General Query Packets | |
c906108c | 20088 | |
8e04817f | 20089 | The following set and query packets have already been defined. |
c906108c | 20090 | |
ee2d5c50 | 20091 | @table @r |
c906108c | 20092 | |
ee2d5c50 AC |
20093 | @item @code{q}@code{C} --- current thread |
20094 | ||
20095 | Return the current thread id. | |
20096 | ||
20097 | Reply: | |
20098 | @table @samp | |
20099 | @item @code{QC}@var{pid} | |
8e04817f | 20100 | Where @var{pid} is a HEX encoded 16 bit process id. |
ee2d5c50 AC |
20101 | @item * |
20102 | Any other reply implies the old pid. | |
20103 | @end table | |
20104 | ||
20105 | @item @code{q}@code{fThreadInfo} -- all thread ids | |
20106 | ||
20107 | @code{q}@code{sThreadInfo} | |
c906108c | 20108 | |
8e04817f AC |
20109 | Obtain a list of active thread ids from the target (OS). Since there |
20110 | may be too many active threads to fit into one reply packet, this query | |
20111 | works iteratively: it may require more than one query/reply sequence to | |
20112 | obtain the entire list of threads. The first query of the sequence will | |
20113 | be the @code{qf}@code{ThreadInfo} query; subsequent queries in the | |
20114 | sequence will be the @code{qs}@code{ThreadInfo} query. | |
ee2d5c50 AC |
20115 | |
20116 | NOTE: replaces the @code{qL} query (see below). | |
20117 | ||
20118 | Reply: | |
20119 | @table @samp | |
20120 | @item @code{m}@var{id} | |
20121 | A single thread id | |
20122 | @item @code{m}@var{id},@var{id}@dots{} | |
20123 | a comma-separated list of thread ids | |
20124 | @item @code{l} | |
20125 | (lower case 'el') denotes end of list. | |
20126 | @end table | |
20127 | ||
20128 | In response to each query, the target will reply with a list of one or | |
20129 | more thread ids, in big-endian hex, separated by commas. @value{GDBN} | |
20130 | will respond to each reply with a request for more thread ids (using the | |
8e04817f AC |
20131 | @code{qs} form of the query), until the target responds with @code{l} |
20132 | (lower-case el, for @code{'last'}). | |
c906108c | 20133 | |
ee2d5c50 AC |
20134 | @item @code{q}@code{ThreadExtraInfo}@code{,}@var{id} --- extra thread info |
20135 | ||
20136 | Where @var{id} is a thread-id in big-endian hex. Obtain a printable | |
20137 | string description of a thread's attributes from the target OS. This | |
20138 | string may contain anything that the target OS thinks is interesting for | |
20139 | @value{GDBN} to tell the user about the thread. The string is displayed | |
20140 | in @value{GDBN}'s @samp{info threads} display. Some examples of | |
20141 | possible thread extra info strings are ``Runnable'', or ``Blocked on | |
20142 | Mutex''. | |
20143 | ||
20144 | Reply: | |
20145 | @table @samp | |
20146 | @item @var{XX@dots{}} | |
20147 | Where @var{XX@dots{}} is a hex encoding of @sc{ascii} data, comprising | |
20148 | the printable string containing the extra information about the thread's | |
8e04817f | 20149 | attributes. |
ee2d5c50 AC |
20150 | @end table |
20151 | ||
20152 | @item @code{q}@code{L}@var{startflag}@var{threadcount}@var{nextthread} --- query @var{LIST} or @var{threadLIST} @strong{(deprecated)} | |
c906108c | 20153 | |
8e04817f AC |
20154 | Obtain thread information from RTOS. Where: @var{startflag} (one hex |
20155 | digit) is one to indicate the first query and zero to indicate a | |
20156 | subsequent query; @var{threadcount} (two hex digits) is the maximum | |
20157 | number of threads the response packet can contain; and @var{nextthread} | |
20158 | (eight hex digits), for subsequent queries (@var{startflag} is zero), is | |
20159 | returned in the response as @var{argthread}. | |
ee2d5c50 AC |
20160 | |
20161 | NOTE: this query is replaced by the @code{q}@code{fThreadInfo} query | |
20162 | (see above). | |
20163 | ||
20164 | Reply: | |
20165 | @table @samp | |
20166 | @item @code{q}@code{M}@var{count}@var{done}@var{argthread}@var{thread@dots{}} | |
8e04817f AC |
20167 | Where: @var{count} (two hex digits) is the number of threads being |
20168 | returned; @var{done} (one hex digit) is zero to indicate more threads | |
20169 | and one indicates no further threads; @var{argthreadid} (eight hex | |
ee2d5c50 AC |
20170 | digits) is @var{nextthread} from the request packet; @var{thread@dots{}} |
20171 | is a sequence of thread IDs from the target. @var{threadid} (eight hex | |
8e04817f | 20172 | digits). See @code{remote.c:parse_threadlist_response()}. |
ee2d5c50 | 20173 | @end table |
c906108c | 20174 | |
ee2d5c50 AC |
20175 | @item @code{q}@code{CRC:}@var{addr}@code{,}@var{length} --- compute CRC of memory block |
20176 | ||
20177 | Reply: | |
20178 | @table @samp | |
20179 | @item @code{E}@var{NN} | |
20180 | An error (such as memory fault) | |
20181 | @item @code{C}@var{CRC32} | |
20182 | A 32 bit cyclic redundancy check of the specified memory region. | |
20183 | @end table | |
20184 | ||
20185 | @item @code{q}@code{Offsets} --- query sect offs | |
c906108c | 20186 | |
8e04817f AC |
20187 | Get section offsets that the target used when re-locating the downloaded |
20188 | image. @emph{Note: while a @code{Bss} offset is included in the | |
20189 | response, @value{GDBN} ignores this and instead applies the @code{Data} | |
20190 | offset to the @code{Bss} section.} | |
c906108c | 20191 | |
ee2d5c50 AC |
20192 | Reply: |
20193 | @table @samp | |
20194 | @item @code{Text=}@var{xxx}@code{;Data=}@var{yyy}@code{;Bss=}@var{zzz} | |
20195 | @end table | |
20196 | ||
20197 | @item @code{q}@code{P}@var{mode}@var{threadid} --- thread info request | |
20198 | ||
8e04817f AC |
20199 | Returns information on @var{threadid}. Where: @var{mode} is a hex |
20200 | encoded 32 bit mode; @var{threadid} is a hex encoded 64 bit thread ID. | |
ee2d5c50 AC |
20201 | |
20202 | Reply: | |
20203 | @table @samp | |
20204 | @item * | |
20205 | @end table | |
20206 | ||
8e04817f | 20207 | See @code{remote.c:remote_unpack_thread_info_response()}. |
c906108c | 20208 | |
ee2d5c50 AC |
20209 | @item @code{q}@code{Rcmd,}@var{command} --- remote command |
20210 | ||
20211 | @var{command} (hex encoded) is passed to the local interpreter for | |
8e04817f AC |
20212 | execution. Invalid commands should be reported using the output string. |
20213 | Before the final result packet, the target may also respond with a | |
ee2d5c50 AC |
20214 | number of intermediate @code{O}@var{output} console output packets. |
20215 | @emph{Implementors should note that providing access to a stubs's | |
20216 | interpreter may have security implications}. | |
20217 | ||
20218 | Reply: | |
20219 | @table @samp | |
20220 | @item OK | |
8e04817f | 20221 | A command response with no output. |
ee2d5c50 | 20222 | @item @var{OUTPUT} |
8e04817f | 20223 | A command response with the hex encoded output string @var{OUTPUT}. |
ee2d5c50 | 20224 | @item @code{E}@var{NN} |
8e04817f | 20225 | Indicate a badly formed request. |
ee2d5c50 | 20226 | @item @samp{} |
8e04817f | 20227 | When @samp{q}@samp{Rcmd} is not recognized. |
ee2d5c50 AC |
20228 | @end table |
20229 | ||
20230 | @item @code{qSymbol::} --- symbol lookup | |
c906108c | 20231 | |
8e04817f AC |
20232 | Notify the target that @value{GDBN} is prepared to serve symbol lookup |
20233 | requests. Accept requests from the target for the values of symbols. | |
ee2d5c50 AC |
20234 | |
20235 | Reply: | |
20236 | @table @samp | |
20237 | @item @code{OK} | |
8e04817f | 20238 | The target does not need to look up any (more) symbols. |
ee2d5c50 AC |
20239 | @item @code{qSymbol:}@var{sym_name} |
20240 | The target requests the value of symbol @var{sym_name} (hex encoded). | |
20241 | @value{GDBN} may provide the value by using the | |
20242 | @code{qSymbol:}@var{sym_value}:@var{sym_name} message, described below. | |
20243 | @end table | |
20244 | ||
20245 | @item @code{qSymbol:}@var{sym_value}:@var{sym_name} --- symbol value | |
20246 | ||
20247 | Set the value of @var{sym_name} to @var{sym_value}. | |
20248 | ||
20249 | @var{sym_name} (hex encoded) is the name of a symbol whose value the | |
20250 | target has previously requested. | |
20251 | ||
20252 | @var{sym_value} (hex) is the value for symbol @var{sym_name}. If | |
20253 | @value{GDBN} cannot supply a value for @var{sym_name}, then this field | |
20254 | will be empty. | |
20255 | ||
20256 | Reply: | |
20257 | @table @samp | |
20258 | @item @code{OK} | |
8e04817f | 20259 | The target does not need to look up any (more) symbols. |
ee2d5c50 AC |
20260 | @item @code{qSymbol:}@var{sym_name} |
20261 | The target requests the value of a new symbol @var{sym_name} (hex | |
20262 | encoded). @value{GDBN} will continue to supply the values of symbols | |
20263 | (if available), until the target ceases to request them. | |
20264 | @end table | |
eb12ee30 | 20265 | |
ee2d5c50 AC |
20266 | @end table |
20267 | ||
20268 | @node Register Packet Format | |
20269 | @section Register Packet Format | |
eb12ee30 | 20270 | |
8e04817f | 20271 | The following @samp{g}/@samp{G} packets have previously been defined. |
ee2d5c50 AC |
20272 | In the below, some thirty-two bit registers are transferred as |
20273 | sixty-four bits. Those registers should be zero/sign extended (which?) | |
20274 | to fill the space allocated. Register bytes are transfered in target | |
20275 | byte order. The two nibbles within a register byte are transfered | |
20276 | most-significant - least-significant. | |
eb12ee30 | 20277 | |
ee2d5c50 | 20278 | @table @r |
eb12ee30 | 20279 | |
8e04817f | 20280 | @item MIPS32 |
ee2d5c50 | 20281 | |
8e04817f AC |
20282 | All registers are transfered as thirty-two bit quantities in the order: |
20283 | 32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point | |
20284 | registers; fsr; fir; fp. | |
eb12ee30 | 20285 | |
8e04817f | 20286 | @item MIPS64 |
ee2d5c50 | 20287 | |
8e04817f AC |
20288 | All registers are transfered as sixty-four bit quantities (including |
20289 | thirty-two bit registers such as @code{sr}). The ordering is the same | |
20290 | as @code{MIPS32}. | |
eb12ee30 | 20291 | |
ee2d5c50 AC |
20292 | @end table |
20293 | ||
20294 | @node Examples | |
20295 | @section Examples | |
eb12ee30 | 20296 | |
8e04817f AC |
20297 | Example sequence of a target being re-started. Notice how the restart |
20298 | does not get any direct output: | |
eb12ee30 | 20299 | |
474c8240 | 20300 | @smallexample |
d2c6833e AC |
20301 | -> @code{R00} |
20302 | <- @code{+} | |
8e04817f | 20303 | @emph{target restarts} |
d2c6833e | 20304 | -> @code{?} |
8e04817f | 20305 | <- @code{+} |
d2c6833e AC |
20306 | <- @code{T001:1234123412341234} |
20307 | -> @code{+} | |
474c8240 | 20308 | @end smallexample |
eb12ee30 | 20309 | |
8e04817f | 20310 | Example sequence of a target being stepped by a single instruction: |
eb12ee30 | 20311 | |
474c8240 | 20312 | @smallexample |
d2c6833e | 20313 | -> @code{G1445@dots{}} |
8e04817f | 20314 | <- @code{+} |
d2c6833e AC |
20315 | -> @code{s} |
20316 | <- @code{+} | |
20317 | @emph{time passes} | |
20318 | <- @code{T001:1234123412341234} | |
8e04817f | 20319 | -> @code{+} |
d2c6833e | 20320 | -> @code{g} |
8e04817f | 20321 | <- @code{+} |
d2c6833e AC |
20322 | <- @code{1455@dots{}} |
20323 | -> @code{+} | |
474c8240 | 20324 | @end smallexample |
eb12ee30 | 20325 | |
0ce1b118 CV |
20326 | @node File-I/O remote protocol extension |
20327 | @section File-I/O remote protocol extension | |
20328 | @cindex File-I/O remote protocol extension | |
20329 | ||
20330 | @menu | |
20331 | * File-I/O Overview:: | |
20332 | * Protocol basics:: | |
20333 | * The `F' request packet:: | |
20334 | * The `F' reply packet:: | |
20335 | * Memory transfer:: | |
20336 | * The Ctrl-C message:: | |
20337 | * Console I/O:: | |
20338 | * The isatty call:: | |
20339 | * The system call:: | |
20340 | * List of supported calls:: | |
20341 | * Protocol specific representation of datatypes:: | |
20342 | * Constants:: | |
20343 | * File-I/O Examples:: | |
20344 | @end menu | |
20345 | ||
20346 | @node File-I/O Overview | |
20347 | @subsection File-I/O Overview | |
20348 | @cindex file-i/o overview | |
20349 | ||
20350 | The File I/O remote protocol extension (short: File-I/O) allows the | |
20351 | target to use the hosts file system and console I/O when calling various | |
20352 | system calls. System calls on the target system are translated into a | |
20353 | remote protocol packet to the host system which then performs the needed | |
20354 | actions and returns with an adequate response packet to the target system. | |
20355 | This simulates file system operations even on targets that lack file systems. | |
20356 | ||
20357 | The protocol is defined host- and target-system independent. It uses | |
20358 | it's own independent representation of datatypes and values. Both, | |
20359 | @value{GDBN} and the target's @value{GDBN} stub are responsible for | |
20360 | translating the system dependent values into the unified protocol values | |
20361 | when data is transmitted. | |
20362 | ||
20363 | The communication is synchronous. A system call is possible only | |
20364 | when GDB is waiting for the @samp{C}, @samp{c}, @samp{S} or @samp{s} | |
20365 | packets. While @value{GDBN} handles the request for a system call, | |
20366 | the target is stopped to allow deterministic access to the target's | |
20367 | memory. Therefore File-I/O is not interuptible by target signals. It | |
20368 | is possible to interrupt File-I/O by a user interrupt (Ctrl-C), though. | |
20369 | ||
20370 | The target's request to perform a host system call does not finish | |
20371 | the latest @samp{C}, @samp{c}, @samp{S} or @samp{s} action. That means, | |
20372 | after finishing the system call, the target returns to continuing the | |
20373 | previous activity (continue, step). No additional continue or step | |
20374 | request from @value{GDBN} is required. | |
20375 | ||
20376 | @smallexample | |
20377 | (gdb) continue | |
20378 | <- target requests 'system call X' | |
20379 | target is stopped, @value{GDBN} executes system call | |
20380 | -> GDB returns result | |
20381 | ... target continues, GDB returns to wait for the target | |
20382 | <- target hits breakpoint and sends a Txx packet | |
20383 | @end smallexample | |
20384 | ||
20385 | The protocol is only used for files on the host file system and | |
20386 | for I/O on the console. Character or block special devices, pipes, | |
20387 | named pipes or sockets or any other communication method on the host | |
20388 | system are not supported by this protocol. | |
20389 | ||
20390 | @node Protocol basics | |
20391 | @subsection Protocol basics | |
20392 | @cindex protocol basics, file-i/o | |
20393 | ||
20394 | The File-I/O protocol uses the @code{F} packet, as request as well | |
20395 | as as reply packet. Since a File-I/O system call can only occur when | |
20396 | @value{GDBN} is waiting for the continuing or stepping target, the | |
20397 | File-I/O request is a reply that @value{GDBN} has to expect as a result | |
20398 | of a former @samp{C}, @samp{c}, @samp{S} or @samp{s} packet. | |
20399 | This @code{F} packet contains all information needed to allow @value{GDBN} | |
20400 | to call the appropriate host system call: | |
20401 | ||
20402 | @itemize @bullet | |
20403 | @item | |
20404 | A unique identifier for the requested system call. | |
20405 | ||
20406 | @item | |
20407 | All parameters to the system call. Pointers are given as addresses | |
20408 | in the target memory address space. Pointers to strings are given as | |
20409 | pointer/length pair. Numerical values are given as they are. | |
20410 | Numerical control values are given in a protocol specific representation. | |
20411 | ||
20412 | @end itemize | |
20413 | ||
20414 | At that point @value{GDBN} has to perform the following actions. | |
20415 | ||
20416 | @itemize @bullet | |
20417 | @item | |
20418 | If parameter pointer values are given, which point to data needed as input | |
20419 | to a system call, @value{GDBN} requests this data from the target with a | |
20420 | standard @code{m} packet request. This additional communication has to be | |
20421 | expected by the target implementation and is handled as any other @code{m} | |
20422 | packet. | |
20423 | ||
20424 | @item | |
20425 | @value{GDBN} translates all value from protocol representation to host | |
20426 | representation as needed. Datatypes are coerced into the host types. | |
20427 | ||
20428 | @item | |
20429 | @value{GDBN} calls the system call | |
20430 | ||
20431 | @item | |
20432 | It then coerces datatypes back to protocol representation. | |
20433 | ||
20434 | @item | |
20435 | If pointer parameters in the request packet point to buffer space in which | |
20436 | a system call is expected to copy data to, the data is transmitted to the | |
20437 | target using a @code{M} or @code{X} packet. This packet has to be expected | |
20438 | by the target implementation and is handled as any other @code{M} or @code{X} | |
20439 | packet. | |
20440 | ||
20441 | @end itemize | |
20442 | ||
20443 | Eventually @value{GDBN} replies with another @code{F} packet which contains all | |
20444 | necessary information for the target to continue. This at least contains | |
20445 | ||
20446 | @itemize @bullet | |
20447 | @item | |
20448 | Return value. | |
20449 | ||
20450 | @item | |
20451 | @code{errno}, if has been changed by the system call. | |
20452 | ||
20453 | @item | |
20454 | ``Ctrl-C'' flag. | |
20455 | ||
20456 | @end itemize | |
20457 | ||
20458 | After having done the needed type and value coercion, the target continues | |
20459 | the latest continue or step action. | |
20460 | ||
20461 | @node The `F' request packet | |
20462 | @subsection The @code{F} request packet | |
20463 | @cindex file-i/o request packet | |
20464 | @cindex @code{F} request packet | |
20465 | ||
20466 | The @code{F} request packet has the following format: | |
20467 | ||
20468 | @table @samp | |
20469 | ||
20470 | @smallexample | |
20471 | @code{F}@var{call-id}@code{,}@var{parameter@dots{}} | |
20472 | @end smallexample | |
20473 | ||
20474 | @var{call-id} is the identifier to indicate the host system call to be called. | |
20475 | This is just the name of the function. | |
20476 | ||
20477 | @var{parameter@dots{}} are the parameters to the system call. | |
20478 | ||
20479 | @end table | |
20480 | ||
20481 | Parameters are hexadecimal integer values, either the real values in case | |
20482 | of scalar datatypes, as pointers to target buffer space in case of compound | |
20483 | datatypes and unspecified memory areas or as pointer/length pairs in case | |
20484 | of string parameters. These are appended to the call-id, each separated | |
20485 | from its predecessor by a comma. All values are transmitted in ASCII | |
20486 | string representation, pointer/length pairs separated by a slash. | |
20487 | ||
20488 | @node The `F' reply packet | |
20489 | @subsection The @code{F} reply packet | |
20490 | @cindex file-i/o reply packet | |
20491 | @cindex @code{F} reply packet | |
20492 | ||
20493 | The @code{F} reply packet has the following format: | |
20494 | ||
20495 | @table @samp | |
20496 | ||
20497 | @smallexample | |
20498 | @code{F}@var{retcode}@code{,}@var{errno}@code{,}@var{Ctrl-C flag}@code{;}@var{call specific attachment} | |
20499 | @end smallexample | |
20500 | ||
20501 | @var{retcode} is the return code of the system call as hexadecimal value. | |
20502 | ||
20503 | @var{errno} is the errno set by the call, in protocol specific representation. | |
20504 | This parameter can be omitted if the call was successful. | |
20505 | ||
20506 | @var{Ctrl-C flag} is only send if the user requested a break. In this | |
20507 | case, @var{errno} must be send as well, even if the call was successful. | |
20508 | The @var{Ctrl-C flag} itself consists of the character 'C': | |
20509 | ||
20510 | @smallexample | |
20511 | F0,0,C | |
20512 | @end smallexample | |
20513 | ||
20514 | @noindent | |
20515 | or, if the call was interupted before the host call has been performed: | |
20516 | ||
20517 | @smallexample | |
20518 | F-1,4,C | |
20519 | @end smallexample | |
20520 | ||
20521 | @noindent | |
20522 | assuming 4 is the protocol specific representation of @code{EINTR}. | |
20523 | ||
20524 | @end table | |
20525 | ||
20526 | @node Memory transfer | |
20527 | @subsection Memory transfer | |
20528 | @cindex memory transfer, in file-i/o protocol | |
20529 | ||
20530 | Structured data which is transferred using a memory read or write as e.g.@: | |
20531 | a @code{struct stat} is expected to be in a protocol specific format with | |
20532 | all scalar multibyte datatypes being big endian. This should be done by | |
20533 | the target before the @code{F} packet is sent resp.@: by @value{GDBN} before | |
20534 | it transfers memory to the target. Transferred pointers to structured | |
20535 | data should point to the already coerced data at any time. | |
20536 | ||
20537 | @node The Ctrl-C message | |
20538 | @subsection The Ctrl-C message | |
20539 | @cindex ctrl-c message, in file-i/o protocol | |
20540 | ||
20541 | A special case is, if the @var{Ctrl-C flag} is set in the @value{GDBN} | |
20542 | reply packet. In this case the target should behave, as if it had | |
20543 | gotten a break message. The meaning for the target is ``system call | |
20544 | interupted by @code{SIGINT}''. Consequentially, the target should actually stop | |
20545 | (as with a break message) and return to @value{GDBN} with a @code{T02} | |
20546 | packet. In this case, it's important for the target to know, in which | |
20547 | state the system call was interrupted. Since this action is by design | |
20548 | not an atomic operation, we have to differ between two cases: | |
20549 | ||
20550 | @itemize @bullet | |
20551 | @item | |
20552 | The system call hasn't been performed on the host yet. | |
20553 | ||
20554 | @item | |
20555 | The system call on the host has been finished. | |
20556 | ||
20557 | @end itemize | |
20558 | ||
20559 | These two states can be distinguished by the target by the value of the | |
20560 | returned @code{errno}. If it's the protocol representation of @code{EINTR}, the system | |
20561 | call hasn't been performed. This is equivalent to the @code{EINTR} handling | |
20562 | on POSIX systems. In any other case, the target may presume that the | |
20563 | system call has been finished --- successful or not --- and should behave | |
20564 | as if the break message arrived right after the system call. | |
20565 | ||
20566 | @value{GDBN} must behave reliable. If the system call has not been called | |
20567 | yet, @value{GDBN} may send the @code{F} reply immediately, setting @code{EINTR} as | |
20568 | @code{errno} in the packet. If the system call on the host has been finished | |
20569 | before the user requests a break, the full action must be finshed by | |
20570 | @value{GDBN}. This requires sending @code{M} or @code{X} packets as they fit. | |
20571 | The @code{F} packet may only be send when either nothing has happened | |
20572 | or the full action has been completed. | |
20573 | ||
20574 | @node Console I/O | |
20575 | @subsection Console I/O | |
20576 | @cindex console i/o as part of file-i/o | |
20577 | ||
20578 | By default and if not explicitely closed by the target system, the file | |
20579 | descriptors 0, 1 and 2 are connected to the @value{GDBN} console. Output | |
20580 | on the @value{GDBN} console is handled as any other file output operation | |
20581 | (@code{write(1, @dots{})} or @code{write(2, @dots{})}). Console input is handled | |
20582 | by @value{GDBN} so that after the target read request from file descriptor | |
20583 | 0 all following typing is buffered until either one of the following | |
20584 | conditions is met: | |
20585 | ||
20586 | @itemize @bullet | |
20587 | @item | |
20588 | The user presses @kbd{Ctrl-C}. The behaviour is as explained above, the | |
20589 | @code{read} | |
20590 | system call is treated as finished. | |
20591 | ||
20592 | @item | |
20593 | The user presses @kbd{Enter}. This is treated as end of input with a trailing | |
20594 | line feed. | |
20595 | ||
20596 | @item | |
20597 | The user presses @kbd{Ctrl-D}. This is treated as end of input. No trailing | |
20598 | character, especially no Ctrl-D is appended to the input. | |
20599 | ||
20600 | @end itemize | |
20601 | ||
20602 | If the user has typed more characters as fit in the buffer given to | |
20603 | the read call, the trailing characters are buffered in @value{GDBN} until | |
20604 | either another @code{read(0, @dots{})} is requested by the target or debugging | |
20605 | is stopped on users request. | |
20606 | ||
20607 | @node The isatty call | |
20608 | @subsection The isatty(3) call | |
20609 | @cindex isatty call, file-i/o protocol | |
20610 | ||
20611 | A special case in this protocol is the library call @code{isatty} which | |
20612 | is implemented as it's own call inside of this protocol. It returns | |
20613 | 1 to the target if the file descriptor given as parameter is attached | |
20614 | to the @value{GDBN} console, 0 otherwise. Implementing through system calls | |
20615 | would require implementing @code{ioctl} and would be more complex than | |
20616 | needed. | |
20617 | ||
20618 | @node The system call | |
20619 | @subsection The system(3) call | |
20620 | @cindex system call, file-i/o protocol | |
20621 | ||
20622 | The other special case in this protocol is the @code{system} call which | |
20623 | is implemented as it's own call, too. @value{GDBN} is taking over the full | |
20624 | task of calling the necessary host calls to perform the @code{system} | |
20625 | call. The return value of @code{system} is simplified before it's returned | |
20626 | to the target. Basically, the only signal transmitted back is @code{EINTR} | |
20627 | in case the user pressed @kbd{Ctrl-C}. Otherwise the return value consists | |
20628 | entirely of the exit status of the called command. | |
20629 | ||
20630 | Due to security concerns, the @code{system} call is refused to be called | |
20631 | by @value{GDBN} by default. The user has to allow this call explicitly by | |
20632 | entering | |
20633 | ||
20634 | @table @samp | |
20635 | @kindex set remote system-call-allowed 1 | |
20636 | @item @code{set remote system-call-allowed 1} | |
20637 | @end table | |
20638 | ||
20639 | Disabling the @code{system} call is done by | |
20640 | ||
20641 | @table @samp | |
20642 | @kindex set remote system-call-allowed 0 | |
20643 | @item @code{set remote system-call-allowed 0} | |
20644 | @end table | |
20645 | ||
20646 | The current setting is shown by typing | |
20647 | ||
20648 | @table @samp | |
20649 | @kindex show remote system-call-allowed | |
20650 | @item @code{show remote system-call-allowed} | |
20651 | @end table | |
20652 | ||
20653 | @node List of supported calls | |
20654 | @subsection List of supported calls | |
20655 | @cindex list of supported file-i/o calls | |
20656 | ||
20657 | @menu | |
20658 | * open:: | |
20659 | * close:: | |
20660 | * read:: | |
20661 | * write:: | |
20662 | * lseek:: | |
20663 | * rename:: | |
20664 | * unlink:: | |
20665 | * stat/fstat:: | |
20666 | * gettimeofday:: | |
20667 | * isatty:: | |
20668 | * system:: | |
20669 | @end menu | |
20670 | ||
20671 | @node open | |
20672 | @unnumberedsubsubsec open | |
20673 | @cindex open, file-i/o system call | |
20674 | ||
20675 | @smallexample | |
20676 | @exdent Synopsis: | |
20677 | int open(const char *pathname, int flags); | |
20678 | int open(const char *pathname, int flags, mode_t mode); | |
20679 | ||
20680 | @exdent Request: | |
20681 | Fopen,pathptr/len,flags,mode | |
20682 | @end smallexample | |
20683 | ||
20684 | @noindent | |
20685 | @code{flags} is the bitwise or of the following values: | |
20686 | ||
20687 | @table @code | |
20688 | @item O_CREAT | |
20689 | If the file does not exist it will be created. The host | |
20690 | rules apply as far as file ownership and time stamps | |
20691 | are concerned. | |
20692 | ||
20693 | @item O_EXCL | |
20694 | When used with O_CREAT, if the file already exists it is | |
20695 | an error and open() fails. | |
20696 | ||
20697 | @item O_TRUNC | |
20698 | If the file already exists and the open mode allows | |
20699 | writing (O_RDWR or O_WRONLY is given) it will be | |
20700 | truncated to length 0. | |
20701 | ||
20702 | @item O_APPEND | |
20703 | The file is opened in append mode. | |
20704 | ||
20705 | @item O_RDONLY | |
20706 | The file is opened for reading only. | |
20707 | ||
20708 | @item O_WRONLY | |
20709 | The file is opened for writing only. | |
20710 | ||
20711 | @item O_RDWR | |
20712 | The file is opened for reading and writing. | |
20713 | ||
20714 | @noindent | |
20715 | Each other bit is silently ignored. | |
20716 | ||
20717 | @end table | |
20718 | ||
20719 | @noindent | |
20720 | @code{mode} is the bitwise or of the following values: | |
20721 | ||
20722 | @table @code | |
20723 | @item S_IRUSR | |
20724 | User has read permission. | |
20725 | ||
20726 | @item S_IWUSR | |
20727 | User has write permission. | |
20728 | ||
20729 | @item S_IRGRP | |
20730 | Group has read permission. | |
20731 | ||
20732 | @item S_IWGRP | |
20733 | Group has write permission. | |
20734 | ||
20735 | @item S_IROTH | |
20736 | Others have read permission. | |
20737 | ||
20738 | @item S_IWOTH | |
20739 | Others have write permission. | |
20740 | ||
20741 | @noindent | |
20742 | Each other bit is silently ignored. | |
20743 | ||
20744 | @end table | |
20745 | ||
20746 | @smallexample | |
20747 | @exdent Return value: | |
20748 | open returns the new file descriptor or -1 if an error | |
20749 | occured. | |
20750 | ||
20751 | @exdent Errors: | |
20752 | @end smallexample | |
20753 | ||
20754 | @table @code | |
20755 | @item EEXIST | |
20756 | pathname already exists and O_CREAT and O_EXCL were used. | |
20757 | ||
20758 | @item EISDIR | |
20759 | pathname refers to a directory. | |
20760 | ||
20761 | @item EACCES | |
20762 | The requested access is not allowed. | |
20763 | ||
20764 | @item ENAMETOOLONG | |
20765 | pathname was too long. | |
20766 | ||
20767 | @item ENOENT | |
20768 | A directory component in pathname does not exist. | |
20769 | ||
20770 | @item ENODEV | |
20771 | pathname refers to a device, pipe, named pipe or socket. | |
20772 | ||
20773 | @item EROFS | |
20774 | pathname refers to a file on a read-only filesystem and | |
20775 | write access was requested. | |
20776 | ||
20777 | @item EFAULT | |
20778 | pathname is an invalid pointer value. | |
20779 | ||
20780 | @item ENOSPC | |
20781 | No space on device to create the file. | |
20782 | ||
20783 | @item EMFILE | |
20784 | The process already has the maximum number of files open. | |
20785 | ||
20786 | @item ENFILE | |
20787 | The limit on the total number of files open on the system | |
20788 | has been reached. | |
20789 | ||
20790 | @item EINTR | |
20791 | The call was interrupted by the user. | |
20792 | @end table | |
20793 | ||
20794 | @node close | |
20795 | @unnumberedsubsubsec close | |
20796 | @cindex close, file-i/o system call | |
20797 | ||
20798 | @smallexample | |
20799 | @exdent Synopsis: | |
20800 | int close(int fd); | |
20801 | ||
20802 | @exdent Request: | |
20803 | Fclose,fd | |
20804 | ||
20805 | @exdent Return value: | |
20806 | close returns zero on success, or -1 if an error occurred. | |
20807 | ||
20808 | @exdent Errors: | |
20809 | @end smallexample | |
20810 | ||
20811 | @table @code | |
20812 | @item EBADF | |
20813 | fd isn't a valid open file descriptor. | |
20814 | ||
20815 | @item EINTR | |
20816 | The call was interrupted by the user. | |
20817 | @end table | |
20818 | ||
20819 | @node read | |
20820 | @unnumberedsubsubsec read | |
20821 | @cindex read, file-i/o system call | |
20822 | ||
20823 | @smallexample | |
20824 | @exdent Synopsis: | |
20825 | int read(int fd, void *buf, unsigned int count); | |
20826 | ||
20827 | @exdent Request: | |
20828 | Fread,fd,bufptr,count | |
20829 | ||
20830 | @exdent Return value: | |
20831 | On success, the number of bytes read is returned. | |
20832 | Zero indicates end of file. If count is zero, read | |
20833 | returns zero as well. On error, -1 is returned. | |
20834 | ||
20835 | @exdent Errors: | |
20836 | @end smallexample | |
20837 | ||
20838 | @table @code | |
20839 | @item EBADF | |
20840 | fd is not a valid file descriptor or is not open for | |
20841 | reading. | |
20842 | ||
20843 | @item EFAULT | |
20844 | buf is an invalid pointer value. | |
20845 | ||
20846 | @item EINTR | |
20847 | The call was interrupted by the user. | |
20848 | @end table | |
20849 | ||
20850 | @node write | |
20851 | @unnumberedsubsubsec write | |
20852 | @cindex write, file-i/o system call | |
20853 | ||
20854 | @smallexample | |
20855 | @exdent Synopsis: | |
20856 | int write(int fd, const void *buf, unsigned int count); | |
20857 | ||
20858 | @exdent Request: | |
20859 | Fwrite,fd,bufptr,count | |
20860 | ||
20861 | @exdent Return value: | |
20862 | On success, the number of bytes written are returned. | |
20863 | Zero indicates nothing was written. On error, -1 | |
20864 | is returned. | |
20865 | ||
20866 | @exdent Errors: | |
20867 | @end smallexample | |
20868 | ||
20869 | @table @code | |
20870 | @item EBADF | |
20871 | fd is not a valid file descriptor or is not open for | |
20872 | writing. | |
20873 | ||
20874 | @item EFAULT | |
20875 | buf is an invalid pointer value. | |
20876 | ||
20877 | @item EFBIG | |
20878 | An attempt was made to write a file that exceeds the | |
20879 | host specific maximum file size allowed. | |
20880 | ||
20881 | @item ENOSPC | |
20882 | No space on device to write the data. | |
20883 | ||
20884 | @item EINTR | |
20885 | The call was interrupted by the user. | |
20886 | @end table | |
20887 | ||
20888 | @node lseek | |
20889 | @unnumberedsubsubsec lseek | |
20890 | @cindex lseek, file-i/o system call | |
20891 | ||
20892 | @smallexample | |
20893 | @exdent Synopsis: | |
20894 | long lseek (int fd, long offset, int flag); | |
20895 | ||
20896 | @exdent Request: | |
20897 | Flseek,fd,offset,flag | |
20898 | @end smallexample | |
20899 | ||
20900 | @code{flag} is one of: | |
20901 | ||
20902 | @table @code | |
20903 | @item SEEK_SET | |
20904 | The offset is set to offset bytes. | |
20905 | ||
20906 | @item SEEK_CUR | |
20907 | The offset is set to its current location plus offset | |
20908 | bytes. | |
20909 | ||
20910 | @item SEEK_END | |
20911 | The offset is set to the size of the file plus offset | |
20912 | bytes. | |
20913 | @end table | |
20914 | ||
20915 | @smallexample | |
20916 | @exdent Return value: | |
20917 | On success, the resulting unsigned offset in bytes from | |
20918 | the beginning of the file is returned. Otherwise, a | |
20919 | value of -1 is returned. | |
20920 | ||
20921 | @exdent Errors: | |
20922 | @end smallexample | |
20923 | ||
20924 | @table @code | |
20925 | @item EBADF | |
20926 | fd is not a valid open file descriptor. | |
20927 | ||
20928 | @item ESPIPE | |
20929 | fd is associated with the @value{GDBN} console. | |
20930 | ||
20931 | @item EINVAL | |
20932 | flag is not a proper value. | |
20933 | ||
20934 | @item EINTR | |
20935 | The call was interrupted by the user. | |
20936 | @end table | |
20937 | ||
20938 | @node rename | |
20939 | @unnumberedsubsubsec rename | |
20940 | @cindex rename, file-i/o system call | |
20941 | ||
20942 | @smallexample | |
20943 | @exdent Synopsis: | |
20944 | int rename(const char *oldpath, const char *newpath); | |
20945 | ||
20946 | @exdent Request: | |
20947 | Frename,oldpathptr/len,newpathptr/len | |
20948 | ||
20949 | @exdent Return value: | |
20950 | On success, zero is returned. On error, -1 is returned. | |
20951 | ||
20952 | @exdent Errors: | |
20953 | @end smallexample | |
20954 | ||
20955 | @table @code | |
20956 | @item EISDIR | |
20957 | newpath is an existing directory, but oldpath is not a | |
20958 | directory. | |
20959 | ||
20960 | @item EEXIST | |
20961 | newpath is a non-empty directory. | |
20962 | ||
20963 | @item EBUSY | |
20964 | oldpath or newpath is a directory that is in use by some | |
20965 | process. | |
20966 | ||
20967 | @item EINVAL | |
20968 | An attempt was made to make a directory a subdirectory | |
20969 | of itself. | |
20970 | ||
20971 | @item ENOTDIR | |
20972 | A component used as a directory in oldpath or new | |
20973 | path is not a directory. Or oldpath is a directory | |
20974 | and newpath exists but is not a directory. | |
20975 | ||
20976 | @item EFAULT | |
20977 | oldpathptr or newpathptr are invalid pointer values. | |
20978 | ||
20979 | @item EACCES | |
20980 | No access to the file or the path of the file. | |
20981 | ||
20982 | @item ENAMETOOLONG | |
20983 | ||
20984 | oldpath or newpath was too long. | |
20985 | ||
20986 | @item ENOENT | |
20987 | A directory component in oldpath or newpath does not exist. | |
20988 | ||
20989 | @item EROFS | |
20990 | The file is on a read-only filesystem. | |
20991 | ||
20992 | @item ENOSPC | |
20993 | The device containing the file has no room for the new | |
20994 | directory entry. | |
20995 | ||
20996 | @item EINTR | |
20997 | The call was interrupted by the user. | |
20998 | @end table | |
20999 | ||
21000 | @node unlink | |
21001 | @unnumberedsubsubsec unlink | |
21002 | @cindex unlink, file-i/o system call | |
21003 | ||
21004 | @smallexample | |
21005 | @exdent Synopsis: | |
21006 | int unlink(const char *pathname); | |
21007 | ||
21008 | @exdent Request: | |
21009 | Funlink,pathnameptr/len | |
21010 | ||
21011 | @exdent Return value: | |
21012 | On success, zero is returned. On error, -1 is returned. | |
21013 | ||
21014 | @exdent Errors: | |
21015 | @end smallexample | |
21016 | ||
21017 | @table @code | |
21018 | @item EACCES | |
21019 | No access to the file or the path of the file. | |
21020 | ||
21021 | @item EPERM | |
21022 | The system does not allow unlinking of directories. | |
21023 | ||
21024 | @item EBUSY | |
21025 | The file pathname cannot be unlinked because it's | |
21026 | being used by another process. | |
21027 | ||
21028 | @item EFAULT | |
21029 | pathnameptr is an invalid pointer value. | |
21030 | ||
21031 | @item ENAMETOOLONG | |
21032 | pathname was too long. | |
21033 | ||
21034 | @item ENOENT | |
21035 | A directory component in pathname does not exist. | |
21036 | ||
21037 | @item ENOTDIR | |
21038 | A component of the path is not a directory. | |
21039 | ||
21040 | @item EROFS | |
21041 | The file is on a read-only filesystem. | |
21042 | ||
21043 | @item EINTR | |
21044 | The call was interrupted by the user. | |
21045 | @end table | |
21046 | ||
21047 | @node stat/fstat | |
21048 | @unnumberedsubsubsec stat/fstat | |
21049 | @cindex fstat, file-i/o system call | |
21050 | @cindex stat, file-i/o system call | |
21051 | ||
21052 | @smallexample | |
21053 | @exdent Synopsis: | |
21054 | int stat(const char *pathname, struct stat *buf); | |
21055 | int fstat(int fd, struct stat *buf); | |
21056 | ||
21057 | @exdent Request: | |
21058 | Fstat,pathnameptr/len,bufptr | |
21059 | Ffstat,fd,bufptr | |
21060 | ||
21061 | @exdent Return value: | |
21062 | On success, zero is returned. On error, -1 is returned. | |
21063 | ||
21064 | @exdent Errors: | |
21065 | @end smallexample | |
21066 | ||
21067 | @table @code | |
21068 | @item EBADF | |
21069 | fd is not a valid open file. | |
21070 | ||
21071 | @item ENOENT | |
21072 | A directory component in pathname does not exist or the | |
21073 | path is an empty string. | |
21074 | ||
21075 | @item ENOTDIR | |
21076 | A component of the path is not a directory. | |
21077 | ||
21078 | @item EFAULT | |
21079 | pathnameptr is an invalid pointer value. | |
21080 | ||
21081 | @item EACCES | |
21082 | No access to the file or the path of the file. | |
21083 | ||
21084 | @item ENAMETOOLONG | |
21085 | pathname was too long. | |
21086 | ||
21087 | @item EINTR | |
21088 | The call was interrupted by the user. | |
21089 | @end table | |
21090 | ||
21091 | @node gettimeofday | |
21092 | @unnumberedsubsubsec gettimeofday | |
21093 | @cindex gettimeofday, file-i/o system call | |
21094 | ||
21095 | @smallexample | |
21096 | @exdent Synopsis: | |
21097 | int gettimeofday(struct timeval *tv, void *tz); | |
21098 | ||
21099 | @exdent Request: | |
21100 | Fgettimeofday,tvptr,tzptr | |
21101 | ||
21102 | @exdent Return value: | |
21103 | On success, 0 is returned, -1 otherwise. | |
21104 | ||
21105 | @exdent Errors: | |
21106 | @end smallexample | |
21107 | ||
21108 | @table @code | |
21109 | @item EINVAL | |
21110 | tz is a non-NULL pointer. | |
21111 | ||
21112 | @item EFAULT | |
21113 | tvptr and/or tzptr is an invalid pointer value. | |
21114 | @end table | |
21115 | ||
21116 | @node isatty | |
21117 | @unnumberedsubsubsec isatty | |
21118 | @cindex isatty, file-i/o system call | |
21119 | ||
21120 | @smallexample | |
21121 | @exdent Synopsis: | |
21122 | int isatty(int fd); | |
21123 | ||
21124 | @exdent Request: | |
21125 | Fisatty,fd | |
21126 | ||
21127 | @exdent Return value: | |
21128 | Returns 1 if fd refers to the @value{GDBN} console, 0 otherwise. | |
21129 | ||
21130 | @exdent Errors: | |
21131 | @end smallexample | |
21132 | ||
21133 | @table @code | |
21134 | @item EINTR | |
21135 | The call was interrupted by the user. | |
21136 | @end table | |
21137 | ||
21138 | @node system | |
21139 | @unnumberedsubsubsec system | |
21140 | @cindex system, file-i/o system call | |
21141 | ||
21142 | @smallexample | |
21143 | @exdent Synopsis: | |
21144 | int system(const char *command); | |
21145 | ||
21146 | @exdent Request: | |
21147 | Fsystem,commandptr/len | |
21148 | ||
21149 | @exdent Return value: | |
21150 | The value returned is -1 on error and the return status | |
21151 | of the command otherwise. Only the exit status of the | |
21152 | command is returned, which is extracted from the hosts | |
21153 | system return value by calling WEXITSTATUS(retval). | |
21154 | In case /bin/sh could not be executed, 127 is returned. | |
21155 | ||
21156 | @exdent Errors: | |
21157 | @end smallexample | |
21158 | ||
21159 | @table @code | |
21160 | @item EINTR | |
21161 | The call was interrupted by the user. | |
21162 | @end table | |
21163 | ||
21164 | @node Protocol specific representation of datatypes | |
21165 | @subsection Protocol specific representation of datatypes | |
21166 | @cindex protocol specific representation of datatypes, in file-i/o protocol | |
21167 | ||
21168 | @menu | |
21169 | * Integral datatypes:: | |
21170 | * Pointer values:: | |
21171 | * struct stat:: | |
21172 | * struct timeval:: | |
21173 | @end menu | |
21174 | ||
21175 | @node Integral datatypes | |
21176 | @unnumberedsubsubsec Integral datatypes | |
21177 | @cindex integral datatypes, in file-i/o protocol | |
21178 | ||
21179 | The integral datatypes used in the system calls are | |
21180 | ||
21181 | @smallexample | |
21182 | int@r{,} unsigned int@r{,} long@r{,} unsigned long@r{,} mode_t @r{and} time_t | |
21183 | @end smallexample | |
21184 | ||
21185 | @code{Int}, @code{unsigned int}, @code{mode_t} and @code{time_t} are | |
21186 | implemented as 32 bit values in this protocol. | |
21187 | ||
21188 | @code{Long} and @code{unsigned long} are implemented as 64 bit types. | |
21189 | ||
21190 | @xref{Limits}, for corresponding MIN and MAX values (similar to those | |
21191 | in @file{limits.h}) to allow range checking on host and target. | |
21192 | ||
21193 | @code{time_t} datatypes are defined as seconds since the Epoch. | |
21194 | ||
21195 | All integral datatypes transferred as part of a memory read or write of a | |
21196 | structured datatype e.g.@: a @code{struct stat} have to be given in big endian | |
21197 | byte order. | |
21198 | ||
21199 | @node Pointer values | |
21200 | @unnumberedsubsubsec Pointer values | |
21201 | @cindex pointer values, in file-i/o protocol | |
21202 | ||
21203 | Pointers to target data are transmitted as they are. An exception | |
21204 | is made for pointers to buffers for which the length isn't | |
21205 | transmitted as part of the function call, namely strings. Strings | |
21206 | are transmitted as a pointer/length pair, both as hex values, e.g.@: | |
21207 | ||
21208 | @smallexample | |
21209 | @code{1aaf/12} | |
21210 | @end smallexample | |
21211 | ||
21212 | @noindent | |
21213 | which is a pointer to data of length 18 bytes at position 0x1aaf. | |
21214 | The length is defined as the full string length in bytes, including | |
21215 | the trailing null byte. Example: | |
21216 | ||
21217 | @smallexample | |
21218 | ``hello, world'' at address 0x123456 | |
21219 | @end smallexample | |
21220 | ||
21221 | @noindent | |
21222 | is transmitted as | |
21223 | ||
21224 | @smallexample | |
21225 | @code{123456/d} | |
21226 | @end smallexample | |
21227 | ||
21228 | @node struct stat | |
21229 | @unnumberedsubsubsec struct stat | |
21230 | @cindex struct stat, in file-i/o protocol | |
21231 | ||
21232 | The buffer of type struct stat used by the target and @value{GDBN} is defined | |
21233 | as follows: | |
21234 | ||
21235 | @smallexample | |
21236 | struct stat @{ | |
21237 | unsigned int st_dev; /* device */ | |
21238 | unsigned int st_ino; /* inode */ | |
21239 | mode_t st_mode; /* protection */ | |
21240 | unsigned int st_nlink; /* number of hard links */ | |
21241 | unsigned int st_uid; /* user ID of owner */ | |
21242 | unsigned int st_gid; /* group ID of owner */ | |
21243 | unsigned int st_rdev; /* device type (if inode device) */ | |
21244 | unsigned long st_size; /* total size, in bytes */ | |
21245 | unsigned long st_blksize; /* blocksize for filesystem I/O */ | |
21246 | unsigned long st_blocks; /* number of blocks allocated */ | |
21247 | time_t st_atime; /* time of last access */ | |
21248 | time_t st_mtime; /* time of last modification */ | |
21249 | time_t st_ctime; /* time of last change */ | |
21250 | @}; | |
21251 | @end smallexample | |
21252 | ||
21253 | The integral datatypes are conforming to the definitions given in the | |
21254 | approriate section (see @ref{Integral datatypes}, for details) so this | |
21255 | structure is of size 64 bytes. | |
21256 | ||
21257 | The values of several fields have a restricted meaning and/or | |
21258 | range of values. | |
21259 | ||
21260 | @smallexample | |
21261 | st_dev: 0 file | |
21262 | 1 console | |
21263 | ||
21264 | st_ino: No valid meaning for the target. Transmitted unchanged. | |
21265 | ||
21266 | st_mode: Valid mode bits are described in Appendix C. Any other | |
21267 | bits have currently no meaning for the target. | |
21268 | ||
21269 | st_uid: No valid meaning for the target. Transmitted unchanged. | |
21270 | ||
21271 | st_gid: No valid meaning for the target. Transmitted unchanged. | |
21272 | ||
21273 | st_rdev: No valid meaning for the target. Transmitted unchanged. | |
21274 | ||
21275 | st_atime, st_mtime, st_ctime: | |
21276 | These values have a host and file system dependent | |
21277 | accuracy. Especially on Windows hosts the file systems | |
21278 | don't support exact timing values. | |
21279 | @end smallexample | |
21280 | ||
21281 | The target gets a struct stat of the above representation and is | |
21282 | responsible to coerce it to the target representation before | |
21283 | continuing. | |
21284 | ||
21285 | Note that due to size differences between the host and target | |
21286 | representation of stat members, these members could eventually | |
21287 | get truncated on the target. | |
21288 | ||
21289 | @node struct timeval | |
21290 | @unnumberedsubsubsec struct timeval | |
21291 | @cindex struct timeval, in file-i/o protocol | |
21292 | ||
21293 | The buffer of type struct timeval used by the target and @value{GDBN} | |
21294 | is defined as follows: | |
21295 | ||
21296 | @smallexample | |
21297 | struct timeval @{ | |
21298 | time_t tv_sec; /* second */ | |
21299 | long tv_usec; /* microsecond */ | |
21300 | @}; | |
21301 | @end smallexample | |
21302 | ||
21303 | The integral datatypes are conforming to the definitions given in the | |
21304 | approriate section (see @ref{Integral datatypes}, for details) so this | |
21305 | structure is of size 8 bytes. | |
21306 | ||
21307 | @node Constants | |
21308 | @subsection Constants | |
21309 | @cindex constants, in file-i/o protocol | |
21310 | ||
21311 | The following values are used for the constants inside of the | |
21312 | protocol. @value{GDBN} and target are resposible to translate these | |
21313 | values before and after the call as needed. | |
21314 | ||
21315 | @menu | |
21316 | * Open flags:: | |
21317 | * mode_t values:: | |
21318 | * Errno values:: | |
21319 | * Lseek flags:: | |
21320 | * Limits:: | |
21321 | @end menu | |
21322 | ||
21323 | @node Open flags | |
21324 | @unnumberedsubsubsec Open flags | |
21325 | @cindex open flags, in file-i/o protocol | |
21326 | ||
21327 | All values are given in hexadecimal representation. | |
21328 | ||
21329 | @smallexample | |
21330 | O_RDONLY 0x0 | |
21331 | O_WRONLY 0x1 | |
21332 | O_RDWR 0x2 | |
21333 | O_APPEND 0x8 | |
21334 | O_CREAT 0x200 | |
21335 | O_TRUNC 0x400 | |
21336 | O_EXCL 0x800 | |
21337 | @end smallexample | |
21338 | ||
21339 | @node mode_t values | |
21340 | @unnumberedsubsubsec mode_t values | |
21341 | @cindex mode_t values, in file-i/o protocol | |
21342 | ||
21343 | All values are given in octal representation. | |
21344 | ||
21345 | @smallexample | |
21346 | S_IFREG 0100000 | |
21347 | S_IFDIR 040000 | |
21348 | S_IRUSR 0400 | |
21349 | S_IWUSR 0200 | |
21350 | S_IXUSR 0100 | |
21351 | S_IRGRP 040 | |
21352 | S_IWGRP 020 | |
21353 | S_IXGRP 010 | |
21354 | S_IROTH 04 | |
21355 | S_IWOTH 02 | |
21356 | S_IXOTH 01 | |
21357 | @end smallexample | |
21358 | ||
21359 | @node Errno values | |
21360 | @unnumberedsubsubsec Errno values | |
21361 | @cindex errno values, in file-i/o protocol | |
21362 | ||
21363 | All values are given in decimal representation. | |
21364 | ||
21365 | @smallexample | |
21366 | EPERM 1 | |
21367 | ENOENT 2 | |
21368 | EINTR 4 | |
21369 | EBADF 9 | |
21370 | EACCES 13 | |
21371 | EFAULT 14 | |
21372 | EBUSY 16 | |
21373 | EEXIST 17 | |
21374 | ENODEV 19 | |
21375 | ENOTDIR 20 | |
21376 | EISDIR 21 | |
21377 | EINVAL 22 | |
21378 | ENFILE 23 | |
21379 | EMFILE 24 | |
21380 | EFBIG 27 | |
21381 | ENOSPC 28 | |
21382 | ESPIPE 29 | |
21383 | EROFS 30 | |
21384 | ENAMETOOLONG 91 | |
21385 | EUNKNOWN 9999 | |
21386 | @end smallexample | |
21387 | ||
21388 | EUNKNOWN is used as a fallback error value if a host system returns | |
21389 | any error value not in the list of supported error numbers. | |
21390 | ||
21391 | @node Lseek flags | |
21392 | @unnumberedsubsubsec Lseek flags | |
21393 | @cindex lseek flags, in file-i/o protocol | |
21394 | ||
21395 | @smallexample | |
21396 | SEEK_SET 0 | |
21397 | SEEK_CUR 1 | |
21398 | SEEK_END 2 | |
21399 | @end smallexample | |
21400 | ||
21401 | @node Limits | |
21402 | @unnumberedsubsubsec Limits | |
21403 | @cindex limits, in file-i/o protocol | |
21404 | ||
21405 | All values are given in decimal representation. | |
21406 | ||
21407 | @smallexample | |
21408 | INT_MIN -2147483648 | |
21409 | INT_MAX 2147483647 | |
21410 | UINT_MAX 4294967295 | |
21411 | LONG_MIN -9223372036854775808 | |
21412 | LONG_MAX 9223372036854775807 | |
21413 | ULONG_MAX 18446744073709551615 | |
21414 | @end smallexample | |
21415 | ||
21416 | @node File-I/O Examples | |
21417 | @subsection File-I/O Examples | |
21418 | @cindex file-i/o examples | |
21419 | ||
21420 | Example sequence of a write call, file descriptor 3, buffer is at target | |
21421 | address 0x1234, 6 bytes should be written: | |
21422 | ||
21423 | @smallexample | |
21424 | <- @code{Fwrite,3,1234,6} | |
21425 | @emph{request memory read from target} | |
21426 | -> @code{m1234,6} | |
21427 | <- XXXXXX | |
21428 | @emph{return "6 bytes written"} | |
21429 | -> @code{F6} | |
21430 | @end smallexample | |
21431 | ||
21432 | Example sequence of a read call, file descriptor 3, buffer is at target | |
21433 | address 0x1234, 6 bytes should be read: | |
21434 | ||
21435 | @smallexample | |
21436 | <- @code{Fread,3,1234,6} | |
21437 | @emph{request memory write to target} | |
21438 | -> @code{X1234,6:XXXXXX} | |
21439 | @emph{return "6 bytes read"} | |
21440 | -> @code{F6} | |
21441 | @end smallexample | |
21442 | ||
21443 | Example sequence of a read call, call fails on the host due to invalid | |
21444 | file descriptor (EBADF): | |
21445 | ||
21446 | @smallexample | |
21447 | <- @code{Fread,3,1234,6} | |
21448 | -> @code{F-1,9} | |
21449 | @end smallexample | |
21450 | ||
21451 | Example sequence of a read call, user presses Ctrl-C before syscall on | |
21452 | host is called: | |
21453 | ||
21454 | @smallexample | |
21455 | <- @code{Fread,3,1234,6} | |
21456 | -> @code{F-1,4,C} | |
21457 | <- @code{T02} | |
21458 | @end smallexample | |
21459 | ||
21460 | Example sequence of a read call, user presses Ctrl-C after syscall on | |
21461 | host is called: | |
21462 | ||
21463 | @smallexample | |
21464 | <- @code{Fread,3,1234,6} | |
21465 | -> @code{X1234,6:XXXXXX} | |
21466 | <- @code{T02} | |
21467 | @end smallexample | |
21468 | ||
aab4e0ec | 21469 | @include gpl.texi |
eb12ee30 | 21470 | |
6826cf00 EZ |
21471 | @include fdl.texi |
21472 | ||
6d2ebf8b | 21473 | @node Index |
c906108c SS |
21474 | @unnumbered Index |
21475 | ||
21476 | @printindex cp | |
21477 | ||
21478 | @tex | |
21479 | % I think something like @colophon should be in texinfo. In the | |
21480 | % meantime: | |
21481 | \long\def\colophon{\hbox to0pt{}\vfill | |
21482 | \centerline{The body of this manual is set in} | |
21483 | \centerline{\fontname\tenrm,} | |
21484 | \centerline{with headings in {\bf\fontname\tenbf}} | |
21485 | \centerline{and examples in {\tt\fontname\tentt}.} | |
21486 | \centerline{{\it\fontname\tenit\/},} | |
21487 | \centerline{{\bf\fontname\tenbf}, and} | |
21488 | \centerline{{\sl\fontname\tensl\/}} | |
21489 | \centerline{are used for emphasis.}\vfill} | |
21490 | \page\colophon | |
21491 | % Blame: doc@cygnus.com, 1991. | |
21492 | @end tex | |
21493 | ||
c906108c | 21494 | @bye |