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1 | @c This is part of the Emacs manual. |
2 | @c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001, | |
3f548a7c | 3 | @c 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc. |
8cf51b2c GM |
4 | @c See file emacs.texi for copying conditions. |
5 | @node Building, Maintaining, Programs, Top | |
6 | @chapter Compiling and Testing Programs | |
7 | @cindex building programs | |
8 | @cindex program building | |
9 | @cindex running Lisp functions | |
10 | ||
11 | The previous chapter discusses the Emacs commands that are useful for | |
12 | making changes in programs. This chapter deals with commands that assist | |
13 | in the larger process of compiling and testing programs. | |
14 | ||
15 | @menu | |
16 | * Compilation:: Compiling programs in languages other | |
17 | than Lisp (C, Pascal, etc.). | |
18 | * Compilation Mode:: The mode for visiting compiler errors. | |
19 | * Compilation Shell:: Customizing your shell properly | |
20 | for use in the compilation buffer. | |
21 | * Grep Searching:: Searching with grep. | |
22 | * Flymake:: Finding syntax errors on the fly. | |
23 | * Debuggers:: Running symbolic debuggers for non-Lisp programs. | |
24 | * Executing Lisp:: Various modes for editing Lisp programs, | |
25 | with different facilities for running | |
26 | the Lisp programs. | |
27 | * Libraries: Lisp Libraries. Creating Lisp programs to run in Emacs. | |
28 | * Eval: Lisp Eval. Executing a single Lisp expression in Emacs. | |
29 | * Interaction: Lisp Interaction. Executing Lisp in an Emacs buffer. | |
30 | * External Lisp:: Communicating through Emacs with a separate Lisp. | |
31 | @end menu | |
32 | ||
33 | @node Compilation | |
34 | @section Running Compilations under Emacs | |
35 | @cindex inferior process | |
36 | @cindex make | |
37 | @cindex compilation errors | |
38 | @cindex error log | |
39 | ||
40 | Emacs can run compilers for noninteractive languages such as C and | |
41 | Fortran as inferior processes, feeding the error log into an Emacs buffer. | |
42 | It can also parse the error messages and show you the source lines where | |
43 | compilation errors occurred. | |
44 | ||
45 | @table @kbd | |
46 | @item M-x compile | |
47 | Run a compiler asynchronously under Emacs, with error messages going to | |
48 | the @samp{*compilation*} buffer. | |
49 | @item M-x recompile | |
50 | Invoke a compiler with the same command as in the last invocation of | |
51 | @kbd{M-x compile}. | |
52 | @item M-x kill-compilation | |
53 | Kill the running compilation subprocess. | |
54 | @end table | |
55 | ||
56 | @findex compile | |
57 | To run @code{make} or another compilation command, do @kbd{M-x | |
58 | compile}. This command reads a shell command line using the minibuffer, | |
59 | and then executes the command in an inferior shell, putting output in | |
60 | the buffer named @samp{*compilation*}. The current buffer's default | |
61 | directory is used as the working directory for the execution of the | |
62 | command; normally, therefore, the compilation happens in this | |
63 | directory. | |
64 | ||
65 | @vindex compile-command | |
66 | The default for the compilation command is normally @samp{make -k}, | |
67 | which is correct most of the time for nontrivial programs. | |
68 | (@xref{Top,, Make, make, GNU Make Manual}.) If you have done @kbd{M-x | |
69 | compile} before, the default each time is the command you used the | |
70 | previous time. @code{compile} stores this command in the variable | |
71 | @code{compile-command}, so setting that variable specifies the default | |
72 | for the next use of @kbd{M-x compile}. If a file specifies a file | |
73 | local value for @code{compile-command}, that provides the default when | |
74 | you type @kbd{M-x compile} in that file's buffer. @xref{File | |
75 | Variables}. | |
76 | ||
77 | Starting a compilation displays the buffer @samp{*compilation*} in | |
78 | another window but does not select it. The buffer's mode line tells | |
79 | you whether compilation is finished, with the word @samp{run}, | |
80 | @samp{signal} or @samp{exit} inside the parentheses. You do not have | |
81 | to keep this buffer visible; compilation continues in any case. While | |
82 | a compilation is going on, the string @samp{Compiling} appears in the | |
83 | mode lines of all windows. When this string disappears, the | |
84 | compilation is finished. | |
85 | ||
86 | If you want to watch the compilation transcript as it appears, switch | |
87 | to the @samp{*compilation*} buffer and move point to the end of the | |
88 | buffer. When point is at the end, new compilation output is inserted | |
89 | above point, which remains at the end. If point is not at the end of | |
90 | the buffer, it remains fixed while more compilation output is added at | |
91 | the end of the buffer. | |
92 | ||
93 | @cindex compilation buffer, keeping point at end | |
94 | @vindex compilation-scroll-output | |
95 | If you set the variable @code{compilation-scroll-output} to a | |
96 | non-@code{nil} value, then the compilation buffer always scrolls to | |
97 | follow output as it comes in. | |
98 | ||
99 | @findex recompile | |
100 | To rerun the last compilation with the same command, type @kbd{M-x | |
101 | recompile}. This automatically reuses the compilation command from | |
102 | the last invocation of @kbd{M-x compile}. It also reuses the | |
103 | @samp{*compilation*} buffer and starts the compilation in its default | |
104 | directory, which is the directory in which the previous compilation | |
105 | was started. | |
106 | ||
107 | When the compiler process terminates, for whatever reason, the mode | |
108 | line of the @samp{*compilation*} buffer changes to say @samp{exit} | |
109 | (followed by the exit code, @samp{[0]} for a normal exit), or | |
110 | @samp{signal} (if a signal terminated the process), instead of | |
111 | @samp{run}. | |
112 | ||
113 | @findex kill-compilation | |
114 | Starting a new compilation also kills any compilation already | |
115 | running in @samp{*compilation*}, as the buffer can only handle one | |
116 | compilation at any time. However, @kbd{M-x compile} asks for | |
117 | confirmation before actually killing a compilation that is running. | |
118 | You can also kill the compilation process with @kbd{M-x | |
119 | kill-compilation}. | |
120 | ||
121 | If you want to run two compilations at once, you should start the | |
122 | first one, then rename the @samp{*compilation*} buffer (perhaps using | |
123 | @code{rename-uniquely}; @pxref{Misc Buffer}), and start the other | |
124 | compilation. That will create a new @samp{*compilation*} buffer. | |
125 | ||
126 | Emacs does not expect a compiler process to launch asynchronous | |
127 | subprocesses; if it does, and they keep running after the main | |
128 | compiler process has terminated, Emacs may kill them or their output | |
129 | may not arrive in Emacs. To avoid this problem, make the main process | |
130 | wait for its subprocesses to finish. In a shell script, you can do this | |
131 | using @samp{$!} and @samp{wait}, like this: | |
132 | ||
133 | @example | |
134 | (sleep 10; echo 2nd)& pid=$! # @r{Record pid of subprocess} | |
135 | echo first message | |
136 | wait $pid # @r{Wait for subprocess} | |
137 | @end example | |
138 | ||
139 | If the background process does not output to the compilation buffer, | |
140 | so you only need to prevent it from being killed when the main | |
141 | compilation process terminates, this is sufficient: | |
142 | ||
143 | @example | |
144 | nohup @var{command}; sleep 1 | |
145 | @end example | |
146 | ||
147 | @vindex compilation-environment | |
148 | You can control the environment passed to the compilation command | |
149 | with the variable @code{compilation-environment}. Its value is a list | |
150 | of environment variable settings; each element should be a string of | |
151 | the form @code{"@var{envvarname}=@var{value}"}. These environment | |
152 | variable settings override the usual ones. | |
153 | ||
154 | @node Compilation Mode | |
155 | @section Compilation Mode | |
156 | ||
157 | @cindex Compilation mode | |
158 | @cindex mode, Compilation | |
159 | The @samp{*compilation*} buffer uses a special major mode, | |
160 | Compilation mode, whose main feature is to provide a convenient way to | |
161 | visit the source line corresponding to an error message. These | |
162 | commands are also available in other special buffers that list | |
163 | locations in files, including those made by @kbd{M-x grep} and | |
164 | @kbd{M-x occur}. | |
165 | ||
166 | @table @kbd | |
167 | @item M-g M-n | |
168 | @itemx M-g n | |
169 | @itemx C-x ` | |
170 | Visit the locus of the next error message or match. | |
171 | @item M-g M-p | |
172 | @itemx M-g p | |
173 | Visit the locus of the previous error message or match. | |
174 | @item @key{RET} | |
175 | Visit the locus of the error message that point is on. | |
176 | This command is used in the compilation buffer. | |
177 | @item Mouse-2 | |
178 | Visit the locus of the error message that you click on. | |
179 | @item M-n | |
180 | Find and highlight the locus of the next error message, without | |
181 | selecting the source buffer. | |
182 | @item M-p | |
183 | Find and highlight the locus of the previous error message, without | |
184 | selecting the source buffer. | |
185 | @item M-@} | |
186 | Move point to the next error for a different file than the current | |
187 | one. | |
188 | @item M-@{ | |
189 | Move point to the previous error for a different file than the current | |
190 | one. | |
191 | @item C-c C-f | |
192 | Toggle Next Error Follow minor mode, which makes cursor motion in the | |
193 | compilation buffer produce automatic source display. | |
194 | @end table | |
195 | ||
196 | @findex compile-goto-error | |
197 | You can visit the source for any particular error message by moving | |
198 | point in the @samp{*compilation*} buffer to that error message and | |
199 | typing @key{RET} (@code{compile-goto-error}). Alternatively, you can | |
200 | click @kbd{Mouse-2} on the error message; you need not switch to the | |
201 | @samp{*compilation*} buffer first. | |
202 | ||
203 | @kindex M-g M-n | |
204 | @kindex M-g n | |
205 | @kindex C-x ` | |
206 | @findex next-error | |
207 | @vindex next-error-highlight | |
208 | To parse the compiler error messages sequentially, type @kbd{C-x `} | |
209 | (@code{next-error}). The character following the @kbd{C-x} is the | |
210 | backquote or ``grave accent,'' not the single-quote. This command is | |
211 | available in all buffers, not just in @samp{*compilation*}; it | |
212 | displays the next error message at the top of one window and source | |
213 | location of the error in another window. It also temporarily | |
214 | highlights the relevant source line, for a period controlled by the | |
215 | variable @code{next-error-highlight}. | |
216 | ||
217 | The first time @w{@kbd{C-x `}} is used after the start of a compilation, | |
218 | it moves to the first error's location. Subsequent uses of @kbd{C-x | |
219 | `} advance down to subsequent errors. If you visit a specific error | |
220 | message with @key{RET} or @kbd{Mouse-2}, subsequent @w{@kbd{C-x `}} | |
221 | commands advance from there. When @w{@kbd{C-x `}} gets to the end of the | |
222 | buffer and finds no more error messages to visit, it fails and signals | |
223 | an Emacs error. @w{@kbd{C-u C-x `}} starts scanning from the beginning of | |
224 | the compilation buffer, and goes to the first error's location. | |
225 | ||
226 | @vindex compilation-skip-threshold | |
227 | By default, @w{@kbd{C-x `}} skips less important messages. The variable | |
228 | @code{compilation-skip-threshold} controls this. If its value is 2, | |
229 | @w{@kbd{C-x `}} skips anything less than error, 1 skips anything less | |
230 | than warning, and 0 doesn't skip any messages. The default is 1. | |
231 | ||
232 | When the window has a left fringe, an arrow in the fringe points to | |
233 | the current message in the compilation buffer. The variable | |
234 | @code{compilation-context-lines} controls the number of lines of | |
235 | leading context to display before the current message. Going to an | |
236 | error message location scrolls the @samp{*compilation*} buffer to put | |
237 | the message that far down from the top. The value @code{nil} is | |
238 | special: if there's a left fringe, the window doesn't scroll at all | |
239 | if the message is already visible. If there is no left fringe, | |
240 | @code{nil} means display the message at the top of the window. | |
241 | ||
242 | If you're not in the compilation buffer when you run | |
243 | @code{next-error}, Emacs will look for a buffer that contains error | |
244 | messages. First, it looks for one displayed in the selected frame, | |
245 | then for one that previously had @code{next-error} called on it, and | |
246 | then at the current buffer. Finally, Emacs looks at all the remaining | |
247 | buffers. @code{next-error} signals an error if it can't find any such | |
248 | buffer. | |
249 | ||
250 | @vindex compilation-error-regexp-alist | |
251 | @vindex grep-regexp-alist | |
252 | To parse messages from the compiler, Compilation mode uses the | |
253 | variable @code{compilation-error-regexp-alist} which lists various | |
254 | formats of error messages and tells Emacs how to extract the source file | |
255 | and the line number from the text of a message. If your compiler isn't | |
256 | supported, you can tailor Compilation mode to it by adding elements to | |
257 | that list. A similar variable @code{grep-regexp-alist} tells Emacs how | |
258 | to parse output of a @code{grep} command. | |
259 | ||
260 | @findex compilation-next-error | |
261 | @findex compilation-previous-error | |
262 | @findex compilation-next-file | |
263 | @findex compilation-previous-file | |
264 | Compilation mode also redefines the keys @key{SPC} and @key{DEL} to | |
265 | scroll by screenfuls, and @kbd{M-n} (@code{compilation-next-error}) | |
266 | and @kbd{M-p} (@code{compilation-previous-error}) to move to the next | |
267 | or previous error message. You can also use @kbd{M-@{} | |
268 | (@code{compilation-next-file} and @kbd{M-@}} | |
269 | (@code{compilation-previous-file}) to move up or down to an error | |
270 | message for a different source file. | |
271 | ||
272 | @cindex Next Error Follow mode | |
273 | @findex next-error-follow-minor-mode | |
274 | You can type @kbd{C-c C-f} to toggle Next Error Follow mode. In | |
275 | this minor mode, ordinary cursor motion in the compilation buffer | |
276 | automatically updates the source buffer. For instance, moving the | |
277 | cursor to the next error message causes the location of that error to | |
278 | be displayed immediately. | |
279 | ||
280 | The features of Compilation mode are also available in a minor mode | |
281 | called Compilation Minor mode. This lets you parse error messages in | |
282 | any buffer, not just a normal compilation output buffer. Type @kbd{M-x | |
283 | compilation-minor-mode} to enable the minor mode. This defines the keys | |
284 | @key{RET} and @kbd{Mouse-2}, as in the Compilation major mode. | |
285 | ||
286 | Compilation minor mode works in any buffer, as long as the contents | |
287 | are in a format that it understands. In an Rlogin buffer (@pxref{Remote | |
288 | Host}), Compilation minor mode automatically accesses remote source | |
289 | files by FTP (@pxref{File Names}). | |
290 | ||
291 | @node Compilation Shell | |
292 | @section Subshells for Compilation | |
293 | ||
294 | Emacs uses a shell to run the compilation command, but specifies the | |
295 | option for a noninteractive shell. This means, in particular, that | |
296 | the shell should start with no prompt. If you find your usual shell | |
297 | prompt making an unsightly appearance in the @samp{*compilation*} | |
298 | buffer, it means you have made a mistake in your shell's init file by | |
299 | setting the prompt unconditionally. (This init file's name may be | |
300 | @file{.bashrc}, @file{.profile}, @file{.cshrc}, @file{.shrc}, or | |
301 | various other things, depending on the shell you use.) The shell init | |
302 | file should set the prompt only if there already is a prompt. Here's | |
303 | how to do it in bash: | |
304 | ||
305 | @example | |
306 | if [ "$@{PS1+set@}" = set ] | |
307 | then PS1=@dots{} | |
308 | fi | |
309 | @end example | |
310 | ||
311 | @noindent | |
312 | And here's how to do it in csh: | |
313 | ||
314 | @example | |
315 | if ($?prompt) set prompt = @dots{} | |
316 | @end example | |
317 | ||
318 | There may well be other things that your shell's init file | |
319 | ought to do only for an interactive shell. You can use the same | |
320 | method to conditionalize them. | |
321 | ||
322 | The MS-DOS ``operating system'' does not support asynchronous | |
323 | subprocesses; to work around this lack, @kbd{M-x compile} runs the | |
324 | compilation command synchronously on MS-DOS. As a consequence, you must | |
325 | wait until the command finishes before you can do anything else in | |
326 | Emacs. | |
327 | @iftex | |
328 | @inforef{MS-DOS,,emacs-xtra}. | |
329 | @end iftex | |
330 | @ifnottex | |
331 | @xref{MS-DOS}. | |
332 | @end ifnottex | |
333 | ||
334 | @node Grep Searching | |
335 | @section Searching with Grep under Emacs | |
336 | ||
337 | Just as you can run a compiler from Emacs and then visit the lines | |
338 | with compilation errors, you can also run @code{grep} and then visit | |
339 | the lines on which matches were found. This works by treating the | |
340 | matches reported by @code{grep} as if they were ``errors.'' The | |
341 | buffer of matches uses Grep mode, which is a variant of Compilation | |
342 | mode (@pxref{Compilation Mode}). | |
343 | ||
344 | @table @kbd | |
345 | @item M-x grep | |
346 | @item M-x lgrep | |
347 | Run @code{grep} asynchronously under Emacs, with matching lines | |
348 | listed in the buffer named @samp{*grep*}. | |
349 | @item M-x grep-find | |
350 | @itemx M-x find-grep | |
351 | @itemx M-x rgrep | |
352 | Run @code{grep} via @code{find}, with user-specified arguments, and | |
353 | collect output in the buffer named @samp{*grep*}. | |
354 | @item M-x kill-grep | |
355 | Kill the running @code{grep} subprocess. | |
356 | @end table | |
357 | ||
358 | @findex grep | |
359 | To run @code{grep}, type @kbd{M-x grep}, then enter a command line | |
360 | that specifies how to run @code{grep}. Use the same arguments you | |
361 | would give @code{grep} when running it normally: a @code{grep}-style | |
362 | regexp (usually in single-quotes to quote the shell's special | |
363 | characters) followed by file names, which may use wildcards. If you | |
364 | specify a prefix argument for @kbd{M-x grep}, it finds the tag | |
365 | (@pxref{Tags}) in the buffer around point, and puts that into the | |
366 | default @code{grep} command. | |
367 | ||
368 | Your command need not simply run @code{grep}; you can use any shell | |
369 | command that produces output in the same format. For instance, you | |
370 | can chain @code{grep} commands, like this: | |
371 | ||
372 | @example | |
373 | grep -nH -e foo *.el | grep bar | grep toto | |
374 | @end example | |
375 | ||
376 | The output from @code{grep} goes in the @samp{*grep*} buffer. You | |
377 | can find the corresponding lines in the original files using @w{@kbd{C-x | |
378 | `}}, @key{RET}, and so forth, just like compilation errors. | |
379 | ||
380 | Some grep programs accept a @samp{--color} option to output special | |
381 | markers around matches for the purpose of highlighting. You can make | |
382 | use of this feature by setting @code{grep-highlight-matches} to | |
383 | @code{t}. When displaying a match in the source buffer, the exact | |
384 | match will be highlighted, instead of the entire source line. | |
385 | ||
386 | @findex grep-find | |
387 | @findex find-grep | |
388 | The command @kbd{M-x grep-find} (also available as @kbd{M-x | |
389 | find-grep}) is similar to @kbd{M-x grep}, but it supplies a different | |
390 | initial default for the command---one that runs both @code{find} and | |
391 | @code{grep}, so as to search every file in a directory tree. See also | |
392 | the @code{find-grep-dired} command, in @ref{Dired and Find}. | |
393 | ||
394 | @findex lgrep | |
395 | @findex rgrep | |
396 | The commands @kbd{M-x lgrep} (local grep) and @kbd{M-x rgrep} | |
397 | (recursive grep) are more user-friendly versions of @code{grep} and | |
398 | @code{grep-find}, which prompt separately for the regular expression | |
399 | to match, the files to search, and the base directory for the search. | |
400 | Case sensitivity of the search is controlled by the | |
401 | current value of @code{case-fold-search}. | |
402 | ||
403 | These commands build the shell commands based on the variables | |
404 | @code{grep-template} (for @code{lgrep}) and @code{grep-find-template} | |
405 | (for @code{rgrep}). | |
406 | ||
407 | The files to search can use aliases defined in the variable | |
408 | @code{grep-files-aliases}. | |
409 | ||
410 | Subdirectories listed in the variable | |
411 | @code{grep-find-ignored-directories} such as those typically used by | |
412 | various version control systems, like CVS and arch, are automatically | |
413 | skipped by @code{rgrep}. | |
414 | ||
415 | @node Flymake | |
416 | @section Finding Syntax Errors On The Fly | |
417 | @cindex checking syntax | |
418 | ||
419 | Flymake mode is a minor mode that performs on-the-fly syntax | |
420 | checking for many programming and markup languages, including C, C++, | |
421 | Perl, HTML, and @TeX{}/La@TeX{}. It is somewhat analogous to Flyspell | |
422 | mode, which performs spell checking for ordinary human languages in a | |
423 | similar fashion (@pxref{Spelling}). As you edit a file, Flymake mode | |
424 | runs an appropriate syntax checking tool in the background, using a | |
425 | temporary copy of the buffer. It then parses the error and warning | |
426 | messages, and highlights the erroneous lines in the buffer. The | |
427 | syntax checking tool used depends on the language; for example, for | |
428 | C/C++ files this is usually the C compiler. Flymake can also use | |
429 | build tools such as @code{make} for checking complicated projects. | |
430 | ||
431 | To activate Flymake mode, type @kbd{M-x flymake-mode}. You can move | |
432 | to the errors spotted by Flymake mode with @kbd{M-x | |
433 | flymake-goto-next-error} and @kbd{M-x flymake-goto-prev-error}. To | |
434 | display any error messages associated with the current line, use | |
435 | @kbd{M-x flymake-display-err-menu-for-current-line}. | |
436 | ||
437 | For more details about using Flymake, see @ref{Top, Flymake, | |
438 | Flymake, flymake, The Flymake Manual}. | |
439 | ||
440 | @node Debuggers | |
441 | @section Running Debuggers Under Emacs | |
442 | @cindex debuggers | |
443 | @cindex GUD library | |
444 | @cindex GDB | |
445 | @cindex DBX | |
446 | @cindex SDB | |
447 | @cindex XDB | |
448 | @cindex Perldb | |
449 | @cindex JDB | |
450 | @cindex PDB | |
451 | ||
452 | @c Do you believe in GUD? | |
453 | The GUD (Grand Unified Debugger) library provides an interface to | |
454 | various symbolic debuggers from within Emacs. We recommend the | |
455 | debugger GDB, which is free software, but GUD can also run DBX, SDB or | |
456 | XDB. GUD can also serve as an interface to Perl's debugging mode, the | |
457 | Python debugger PDB, and to JDB, the Java Debugger. | |
458 | @xref{Debugging,, The Lisp Debugger, elisp, the Emacs Lisp Reference | |
459 | Manual}, for information on debugging Emacs Lisp programs. | |
460 | ||
461 | @menu | |
462 | * Starting GUD:: How to start a debugger subprocess. | |
463 | * Debugger Operation:: Connection between the debugger and source buffers. | |
464 | * Commands of GUD:: Key bindings for common commands. | |
465 | * GUD Customization:: Defining your own commands for GUD. | |
466 | * GDB Graphical Interface:: An enhanced mode that uses GDB features to | |
467 | implement a graphical debugging environment through | |
468 | Emacs. | |
469 | @end menu | |
470 | ||
471 | @node Starting GUD | |
472 | @subsection Starting GUD | |
473 | ||
474 | There are several commands for starting a debugger, each corresponding | |
475 | to a particular debugger program. | |
476 | ||
477 | @table @kbd | |
478 | @item M-x gdb @key{RET} @var{file} @key{RET} | |
479 | @findex gdb | |
480 | Run GDB as a subprocess of Emacs. By default, this uses an IDE-like | |
481 | graphical interface; see @ref{GDB Graphical Interface}. Only GDB | |
482 | works with the graphical interface. | |
483 | ||
484 | @item M-x dbx @key{RET} @var{file} @key{RET} | |
485 | @findex dbx | |
486 | Run DBX as a subprocess of Emacs. Since Emacs does not implement a | |
487 | graphical interface for DBX, communication with DBX works by typing | |
488 | commands in the GUD interaction buffer. The same is true for all | |
489 | the other supported debuggers. | |
490 | ||
491 | @item M-x xdb @key{RET} @var{file} @key{RET} | |
492 | @findex xdb | |
493 | @vindex gud-xdb-directories | |
494 | Similar, but run XDB. Use the variable | |
495 | @code{gud-xdb-directories} to specify directories to search for source | |
496 | files. | |
497 | ||
498 | @item M-x sdb @key{RET} @var{file} @key{RET} | |
499 | @findex sdb | |
500 | Similar, but run SDB. | |
501 | ||
502 | Some versions of SDB do not mention source file names in their | |
503 | messages. When you use them, you need to have a valid tags table | |
504 | (@pxref{Tags}) in order for GUD to find functions in the source code. | |
505 | If you have not visited a tags table or the tags table doesn't list one | |
506 | of the functions, you get a message saying @samp{The sdb support | |
507 | requires a valid tags table to work}. If this happens, generate a valid | |
508 | tags table in the working directory and try again. | |
509 | ||
510 | @item M-x perldb @key{RET} @var{file} @key{RET} | |
511 | @findex perldb | |
512 | Run the Perl interpreter in debug mode to debug @var{file}, a Perl program. | |
513 | ||
514 | @item M-x jdb @key{RET} @var{file} @key{RET} | |
515 | @findex jdb | |
516 | Run the Java debugger to debug @var{file}. | |
517 | ||
518 | @item M-x pdb @key{RET} @var{file} @key{RET} | |
519 | @findex pdb | |
520 | Run the Python debugger to debug @var{file}. | |
521 | @end table | |
522 | ||
523 | Each of these commands takes one argument: a command line to invoke | |
524 | the debugger. In the simplest case, specify just the name of the | |
525 | executable file you want to debug. You may also use options that the | |
526 | debugger supports. However, shell wildcards and variables are not | |
527 | allowed. GUD assumes that the first argument not starting with a | |
528 | @samp{-} is the executable file name. | |
529 | ||
4a3a621f | 530 | @c Running a debugger on a remote host |
8cf51b2c GM |
531 | Tramp provides a facility to debug programs on remote hosts. |
532 | @xref{Running a debugger on a remote host, Running a debugger on a remote host,, tramp, The Tramp Manual}. | |
4a3a621f NR |
533 | Both debugger and program are on the same remote host. |
534 | This should not confused with debugging remote programs | |
535 | where the program runs on diferent machine to the debugger, | |
536 | as can be done with GDB, for example. | |
537 | @xref{Remote Debugging,, Debugging Remote Programs, gdb, The GNU debugger}. | |
8cf51b2c GM |
538 | |
539 | @node Debugger Operation | |
540 | @subsection Debugger Operation | |
541 | ||
542 | @cindex fringes, and current execution line in GUD | |
543 | Generally when you run a debugger with GUD, the debugger uses an Emacs | |
544 | buffer for its ordinary input and output. This is called the GUD | |
545 | buffer. Input and output from the program you are debugging also use | |
546 | this buffer. We call this @dfn{text command mode}. The GDB Graphical | |
547 | Interface can use further buffers (@pxref{GDB Graphical Interface}). | |
548 | ||
549 | The debugger displays the source files of the program by visiting | |
550 | them in Emacs buffers. An arrow in the left fringe indicates the | |
551 | current execution line.@footnote{On a text-only terminal, the arrow | |
552 | appears as @samp{=>} and overlays the first two text columns.} Moving | |
553 | point in this buffer does not move the arrow. The arrow is not part | |
554 | of the file's text; it appears only on the screen. | |
555 | ||
556 | You can start editing these source files at any time in the buffers | |
557 | that display them. If you do modify a source file, keep in mind that | |
558 | inserting or deleting lines will throw off the arrow's positioning; | |
559 | GUD has no way of figuring out which line corresponded before your | |
560 | changes to the line number in a debugger message. Also, you'll | |
561 | typically have to recompile and restart the program for your changes | |
562 | to be reflected in the debugger's tables. | |
563 | ||
564 | @cindex tooltips with GUD | |
565 | @vindex tooltip-gud-modes | |
566 | @vindex gud-tooltip-mode | |
567 | @vindex gud-tooltip-echo-area | |
568 | The Tooltip facility (@pxref{Tooltips}) provides support for GUD@. | |
569 | You activate this feature by turning on the minor mode | |
570 | @code{gud-tooltip-mode}. Then you can display a variable's value in a | |
571 | tooltip simply by pointing at it with the mouse. This operates in the | |
572 | GUD buffer and in source buffers with major modes in the list | |
573 | @code{gud-tooltip-modes}. If the variable @code{gud-tooltip-echo-area} | |
574 | is non-@code{nil} then the variable's value is displayed in the echo | |
575 | area. When debugging a C program using the GDB Graphical Interface, you | |
576 | can also display macro definitions associated with an identifier when | |
577 | the program is not executing. | |
578 | ||
579 | GUD tooltips are disabled when you use GDB in text command mode | |
580 | (@pxref{GDB Graphical Interface}), because displaying an expression's | |
581 | value in GDB can sometimes expand a macro and result in a side effect | |
582 | that interferes with the program's operation. The GDB graphical | |
583 | interface supports GUD tooltips and assures they will not cause side | |
584 | effects. | |
585 | ||
586 | @node Commands of GUD | |
587 | @subsection Commands of GUD | |
588 | ||
589 | The GUD interaction buffer uses a variant of Shell mode, so the | |
590 | Emacs commands of Shell mode are available (@pxref{Shell Mode}). All | |
591 | the usual commands for your debugger are available, and you can use | |
592 | the Shell mode history commands to repeat them. If you wish, you can | |
593 | control your debugger process entirely through this buffer. | |
594 | ||
595 | GUD mode also provides commands for setting and clearing | |
596 | breakpoints, for selecting stack frames, and for stepping through the | |
597 | program. These commands are available both in the GUD buffer and | |
598 | globally, but with different key bindings. It also has its own tool | |
599 | bar from which you can invoke the more common commands by clicking on | |
600 | the appropriate icon. This is particularly useful for repetitive | |
601 | commands like @code{gud-next} and @code{gud-step}, and allows you to | |
602 | keep the GUD buffer hidden. | |
603 | ||
604 | The breakpoint commands are normally used in source file buffers, | |
605 | because that is the easiest way to specify where to set or clear the | |
606 | breakpoint. Here's the global command to set a breakpoint: | |
607 | ||
608 | @table @kbd | |
609 | @item C-x @key{SPC} | |
610 | @kindex C-x SPC | |
611 | Set a breakpoint on the source line that point is on. | |
612 | @end table | |
613 | ||
614 | @kindex C-x C-a @r{(GUD)} | |
615 | Here are the other special commands provided by GUD@. The keys | |
616 | starting with @kbd{C-c} are available only in the GUD interaction | |
617 | buffer. The key bindings that start with @kbd{C-x C-a} are available | |
618 | in the GUD interaction buffer and also in source files. Some of these | |
619 | commands are not available to all the supported debuggers. | |
620 | ||
621 | @table @kbd | |
622 | @item C-c C-l | |
623 | @kindex C-c C-l @r{(GUD)} | |
624 | @itemx C-x C-a C-l | |
625 | @findex gud-refresh | |
626 | Display in another window the last line referred to in the GUD | |
627 | buffer (that is, the line indicated in the last location message). | |
628 | This runs the command @code{gud-refresh}. | |
629 | ||
630 | @item C-c C-s | |
631 | @kindex C-c C-s @r{(GUD)} | |
632 | @itemx C-x C-a C-s | |
633 | @findex gud-step | |
634 | Execute a single line of code (@code{gud-step}). If the line contains | |
635 | a function call, execution stops after entering the called function. | |
636 | ||
637 | @item C-c C-n | |
638 | @kindex C-c C-n @r{(GUD)} | |
639 | @itemx C-x C-a C-n | |
640 | @findex gud-next | |
641 | Execute a single line of code, stepping across entire function calls | |
642 | at full speed (@code{gud-next}). | |
643 | ||
644 | @item C-c C-i | |
645 | @kindex C-c C-i @r{(GUD)} | |
646 | @itemx C-x C-a C-i | |
647 | @findex gud-stepi | |
648 | Execute a single machine instruction (@code{gud-stepi}). | |
649 | ||
650 | @item C-c C-p | |
651 | @kindex C-c C-p @r{(GUD)} | |
652 | @itemx C-x C-a C-p | |
653 | @findex gud-print | |
654 | Evaluate the expression at point (@code{gud-print}). If Emacs | |
655 | does not print the exact expression that you want, mark it as a region | |
656 | first. | |
657 | ||
658 | @need 3000 | |
659 | @item C-c C-r | |
660 | @kindex C-c C-r @r{(GUD)} | |
661 | @itemx C-x C-a C-r | |
662 | @findex gud-cont | |
663 | Continue execution without specifying any stopping point. The program | |
664 | will run until it hits a breakpoint, terminates, or gets a signal that | |
665 | the debugger is checking for (@code{gud-cont}). | |
666 | ||
667 | @need 1000 | |
668 | @item C-c C-d | |
669 | @kindex C-c C-d @r{(GUD)} | |
670 | @itemx C-x C-a C-d | |
671 | @findex gud-remove | |
672 | Delete the breakpoint(s) on the current source line, if any | |
673 | (@code{gud-remove}). If you use this command in the GUD interaction | |
674 | buffer, it applies to the line where the program last stopped. | |
675 | ||
676 | @item C-c C-t | |
677 | @kindex C-c C-t @r{(GUD)} | |
678 | @itemx C-x C-a C-t | |
679 | @findex gud-tbreak | |
680 | Set a temporary breakpoint on the current source line, if any | |
681 | (@code{gud-tbreak}). If you use this command in the GUD interaction | |
682 | buffer, it applies to the line where the program last stopped. | |
683 | ||
684 | @item C-c < | |
685 | @kindex C-c < @r{(GUD)} | |
686 | @itemx C-x C-a < | |
687 | @findex gud-up | |
688 | Select the next enclosing stack frame (@code{gud-up}). This is | |
689 | equivalent to the GDB command @samp{up}. | |
690 | ||
691 | @item C-c > | |
692 | @kindex C-c > @r{(GUD)} | |
693 | @itemx C-x C-a > | |
694 | @findex gud-down | |
695 | Select the next inner stack frame (@code{gud-down}). This is | |
696 | equivalent to the GDB command @samp{down}. | |
697 | ||
698 | @item C-c C-u | |
699 | @kindex C-c C-u @r{(GUD)} | |
700 | @itemx C-x C-a C-u | |
701 | @findex gud-until | |
702 | Continue execution to the current line (@code{gud-until}). The | |
703 | program will run until it hits a breakpoint, terminates, gets a signal | |
704 | that the debugger is checking for, or reaches the line on which the | |
705 | cursor currently sits. | |
706 | ||
707 | @item C-c C-f | |
708 | @kindex C-c C-f @r{(GUD)} | |
709 | @itemx C-x C-a C-f | |
710 | @findex gud-finish | |
711 | Run the program until the selected stack frame returns or | |
712 | stops for some other reason (@code{gud-finish}). | |
713 | @end table | |
714 | ||
715 | If you are using GDB, these additional key bindings are available: | |
716 | ||
717 | @table @kbd | |
718 | @item C-x C-a C-j | |
719 | @kindex C-x C-a C-j @r{(GUD)} | |
720 | @findex gud-jump | |
721 | Only useful in a source buffer, @code{gud-jump} transfers the | |
722 | program's execution point to the current line. In other words, the | |
723 | next line that the program executes will be the one where you gave the | |
724 | command. If the new execution line is in a different function from | |
725 | the previously one, GDB prompts for confirmation since the results may | |
726 | be bizarre. See the GDB manual entry regarding @code{jump} for | |
727 | details. | |
728 | ||
729 | @item @key{TAB} | |
730 | @kindex TAB @r{(GUD)} | |
731 | @findex gud-gdb-complete-command | |
732 | With GDB, complete a symbol name (@code{gud-gdb-complete-command}). | |
733 | This key is available only in the GUD interaction buffer. | |
734 | @end table | |
735 | ||
736 | These commands interpret a numeric argument as a repeat count, when | |
737 | that makes sense. | |
738 | ||
739 | Because @key{TAB} serves as a completion command, you can't use it to | |
740 | enter a tab as input to the program you are debugging with GDB. | |
741 | Instead, type @kbd{C-q @key{TAB}} to enter a tab. | |
742 | ||
743 | @node GUD Customization | |
744 | @subsection GUD Customization | |
745 | ||
746 | @vindex gdb-mode-hook | |
747 | @vindex dbx-mode-hook | |
748 | @vindex sdb-mode-hook | |
749 | @vindex xdb-mode-hook | |
750 | @vindex perldb-mode-hook | |
751 | @vindex pdb-mode-hook | |
752 | @vindex jdb-mode-hook | |
753 | On startup, GUD runs one of the following hooks: @code{gdb-mode-hook}, | |
754 | if you are using GDB; @code{dbx-mode-hook}, if you are using DBX; | |
755 | @code{sdb-mode-hook}, if you are using SDB; @code{xdb-mode-hook}, if you | |
756 | are using XDB; @code{perldb-mode-hook}, for Perl debugging mode; | |
757 | @code{pdb-mode-hook}, for PDB; @code{jdb-mode-hook}, for JDB. You can | |
758 | use these hooks to define custom key bindings for the debugger | |
759 | interaction buffer. @xref{Hooks}. | |
760 | ||
761 | Here is a convenient way to define a command that sends a particular | |
762 | command string to the debugger, and set up a key binding for it in the | |
763 | debugger interaction buffer: | |
764 | ||
765 | @findex gud-def | |
766 | @example | |
767 | (gud-def @var{function} @var{cmdstring} @var{binding} @var{docstring}) | |
768 | @end example | |
769 | ||
770 | This defines a command named @var{function} which sends | |
771 | @var{cmdstring} to the debugger process, and gives it the documentation | |
772 | string @var{docstring}. You can then use the command @var{function} in any | |
773 | buffer. If @var{binding} is non-@code{nil}, @code{gud-def} also binds | |
774 | the command to @kbd{C-c @var{binding}} in the GUD buffer's mode and to | |
775 | @kbd{C-x C-a @var{binding}} generally. | |
776 | ||
777 | The command string @var{cmdstring} may contain certain | |
778 | @samp{%}-sequences that stand for data to be filled in at the time | |
779 | @var{function} is called: | |
780 | ||
781 | @table @samp | |
782 | @item %f | |
783 | The name of the current source file. If the current buffer is the GUD | |
784 | buffer, then the ``current source file'' is the file that the program | |
785 | stopped in. | |
786 | ||
787 | @item %l | |
788 | The number of the current source line. If the current buffer is the GUD | |
789 | buffer, then the ``current source line'' is the line that the program | |
790 | stopped in. | |
791 | ||
792 | @item %e | |
793 | In transient-mark-mode the text in the region, if it is active. | |
794 | Otherwise the text of the C lvalue or function-call expression at or | |
795 | adjacent to point. | |
796 | ||
797 | @item %a | |
798 | The text of the hexadecimal address at or adjacent to point. | |
799 | ||
800 | @item %p | |
801 | The numeric argument of the called function, as a decimal number. If | |
802 | the command is used without a numeric argument, @samp{%p} stands for the | |
803 | empty string. | |
804 | ||
805 | If you don't use @samp{%p} in the command string, the command you define | |
806 | ignores any numeric argument. | |
807 | ||
808 | @item %d | |
809 | The name of the directory of the current source file. | |
810 | ||
811 | @item %c | |
812 | Fully qualified class name derived from the expression surrounding point | |
813 | (jdb only). | |
814 | @end table | |
815 | ||
816 | @node GDB Graphical Interface | |
817 | @subsection GDB Graphical Interface | |
818 | ||
819 | By default, the command @code{gdb} starts GDB using a graphical | |
820 | interface, using Emacs windows for display program state information. | |
821 | In effect, this makes Emacs into an IDE (interactive development | |
822 | environment). With it, you do not need to use textual GDB commands; | |
823 | you can control the debugging session with the mouse. For example, | |
824 | you can click in the fringe of a source buffer to set a breakpoint | |
825 | there, or on a stack frame in the stack buffer to select that frame. | |
826 | ||
827 | This mode requires telling GDB that its ``screen size'' is | |
828 | unlimited, so it sets the height and width accordingly. For correct | |
829 | operation you must not change these values during the GDB session. | |
830 | ||
831 | @vindex gud-gdb-command-name | |
7af32ba0 NR |
832 | You can also run GDB in text command mode, like the other debuggers |
833 | in Emacs. To do this, replace the GDB @code{"--annotate=3"} option | |
834 | with @code{"--fullname"} either in the minibuffer for the current | |
835 | Emacs session, or the custom variable @code{gud-gdb-command-name} for | |
836 | all future sessions. You need to use text command mode to debug | |
837 | multiple programs within one Emacs session. You can also use | |
838 | @kbd{M-x gud-gdb} to invoke GDB in text command mode if you have | |
839 | problems before execution has started. | |
8cf51b2c GM |
840 | |
841 | @menu | |
842 | * GDB-UI Layout:: Control the number of displayed buffers. | |
843 | * Source Buffers:: Use the mouse in the fringe/margin to | |
844 | control your program. | |
845 | * Breakpoints Buffer:: A breakpoint control panel. | |
846 | * Stack Buffer:: Select a frame from the call stack. | |
847 | * Other GDB-UI Buffers:: Input/output, locals, registers, | |
848 | assembler, threads and memory buffers. | |
849 | * Watch Expressions:: Monitor variable values in the speedbar. | |
850 | @end menu | |
851 | ||
852 | @node GDB-UI Layout | |
853 | @subsubsection GDB User Interface Layout | |
854 | @cindex GDB User Interface layout | |
855 | ||
856 | @vindex gdb-many-windows | |
857 | If the variable @code{gdb-many-windows} is @code{nil} (the default | |
858 | value) then @kbd{M-x gdb} normally displays only the GUD buffer. | |
859 | However, if the variable @code{gdb-show-main} is also non-@code{nil}, | |
860 | it starts with two windows: one displaying the GUD buffer, and the | |
861 | other showing the source for the @code{main} function of the program | |
862 | you are debugging. | |
863 | ||
864 | If @code{gdb-many-windows} is non-@code{nil}, then @kbd{M-x gdb} | |
865 | displays the following frame layout: | |
866 | ||
867 | @smallexample | |
868 | @group | |
869 | +--------------------------------+--------------------------------+ | |
1a19cb6a | 870 | | GUD buffer (I/O of GDB) | Locals/Registers buffer | |
8cf51b2c GM |
871 | |--------------------------------+--------------------------------+ |
872 | | Primary Source buffer | I/O buffer for debugged pgm | | |
873 | |--------------------------------+--------------------------------+ | |
95dbaaea | 874 | | Stack buffer | Breakpoints/thread buffer | |
8cf51b2c GM |
875 | +--------------------------------+--------------------------------+ |
876 | @end group | |
877 | @end smallexample | |
878 | ||
879 | However, if @code{gdb-use-separate-io-buffer} is @code{nil}, the I/O | |
880 | buffer does not appear and the primary source buffer occupies the full | |
881 | width of the frame. | |
882 | ||
883 | @findex gdb-restore-windows | |
884 | If you change the window layout, for example, while editing and | |
885 | re-compiling your program, then you can restore this standard window | |
886 | layout with the command @code{gdb-restore-windows}. | |
887 | ||
888 | @findex gdb-many-windows | |
889 | To switch between this standard layout and a simple layout | |
890 | containing just the GUD buffer and a source file, type @kbd{M-x | |
891 | gdb-many-windows}. | |
892 | ||
893 | You may also specify additional GDB-related buffers to display, | |
894 | either in the same frame or a different one. Select the buffers you | |
895 | want with the @samp{GUD->GDB-windows} and @samp{GUD->GDB-Frames} | |
896 | sub-menus. If the menu-bar is unavailable, type @code{M-x | |
897 | gdb-display-@var{buffertype}-buffer} or @code{M-x | |
898 | gdb-frame-@var{buffertype}-buffer} respectively, where | |
899 | @var{buffertype} is the relevant buffer type, such as | |
900 | @samp{breakpoints}. Most of these buffers are read-only, and typing | |
901 | @kbd{q} in them kills them. | |
902 | ||
903 | When you finish debugging, kill the GUD buffer with @kbd{C-x k}, | |
904 | which will also kill all the buffers associated with the session. | |
905 | However you need not do this if, after editing and re-compiling your | |
906 | source code within Emacs, you wish continue debugging. When you | |
907 | restart execution, GDB will automatically find your new executable. | |
908 | Keeping the GUD buffer has the advantage of keeping the shell history | |
909 | as well as GDB's breakpoints. You do need to check that the | |
910 | breakpoints in recently edited source files are still in the right | |
911 | places. | |
912 | ||
913 | @node Source Buffers | |
914 | @subsubsection Source Buffers | |
915 | @cindex GDB commands in Fringe | |
916 | ||
917 | @c @findex gdb-mouse-set-clear-breakpoint | |
918 | @c @findex gdb-mouse-toggle-breakpoint | |
d9c4c999 | 919 | Many GDB commands can be entered using key bindings or the tool bar but |
8cf51b2c GM |
920 | sometimes it is quicker to use the fringe. These commands either |
921 | manipulate breakpoints or control program execution. When there is no | |
922 | fringe, you can use the margin but this is only present when the | |
923 | source file already has a breakpoint. | |
924 | ||
925 | You can click @kbd{Mouse-1} in the fringe or display margin of a | |
926 | source buffer to set a breakpoint there and, on a graphical display, a | |
927 | red bullet will appear on that line. If a breakpoint already exists | |
928 | on that line, the same click will remove it. You can also enable or | |
929 | disable a breakpoint by clicking @kbd{C-Mouse-1} on the bullet. | |
930 | ||
931 | A solid arrow in the left fringe of a source buffer indicates the line | |
932 | of the innermost frame where the debugged program has stopped. A | |
933 | hollow arrow indicates the current execution line of higher level | |
934 | frames. | |
935 | ||
936 | If you drag the arrow in the fringe with @kbd{Mouse-1} | |
937 | (@code{gdb-mouse-until}), execution will continue to the line where | |
938 | you release the button, provided it is still in the same frame. | |
939 | Alternatively, you can click @kbd{Mouse-3} at some point in the fringe | |
940 | of this buffer and execution will advance to there. A similar command | |
941 | (@code{gdb-mouse-jump}) allows you to jump to a source line without | |
942 | executing the intermediate lines by clicking @kbd{C-Mouse-3}. This | |
943 | command allows you to go backwards which can be useful for running | |
944 | through code that has already executed, in order to examine its | |
945 | execution in more detail. | |
946 | ||
947 | @table @kbd | |
948 | @item Mouse-1 | |
949 | Set or clear a breakpoint. | |
950 | ||
951 | @item C-Mouse-1 | |
952 | Enable or disable a breakpoint. | |
953 | ||
954 | @item Mouse-3 | |
955 | Continue execution to here. | |
956 | ||
957 | @item C-Mouse-3 | |
958 | Jump to here. | |
959 | @end table | |
960 | ||
961 | If the variable @code{gdb-find-source-frame} is non-@code{nil} and | |
962 | execution stops in a frame for which there is no source code e.g after | |
963 | an interrupt, then Emacs finds and displays the first frame further up | |
964 | stack for which there is source. If it is @code{nil} then the source | |
965 | buffer continues to display the last frame which maybe more useful, | |
966 | for example, when re-setting a breakpoint. | |
967 | ||
968 | @node Breakpoints Buffer | |
969 | @subsubsection Breakpoints Buffer | |
970 | ||
971 | The breakpoints buffer shows the existing breakpoints, watchpoints and | |
972 | catchpoints (@pxref{Breakpoints,,, gdb, The GNU debugger}). It has | |
973 | these special commands, which mostly apply to the @dfn{current | |
974 | breakpoint}, the breakpoint which point is on. | |
975 | ||
976 | @table @kbd | |
977 | @item @key{SPC} | |
978 | @kindex SPC @r{(GDB breakpoints buffer)} | |
979 | @findex gdb-toggle-breakpoint | |
980 | Enable/disable the current breakpoint (@code{gdb-toggle-breakpoint}). | |
981 | On a graphical display, this changes the color of a bullet in the | |
982 | margin of a source buffer at the relevant line. This is red when | |
983 | the breakpoint is enabled and grey when it is disabled. Text-only | |
984 | terminals correspondingly display a @samp{B} or @samp{b}. | |
985 | ||
986 | @item D | |
987 | @kindex D @r{(GDB breakpoints buffer)} | |
988 | @findex gdb-delete-breakpoint | |
989 | Delete the current breakpoint (@code{gdb-delete-breakpoint}). | |
990 | ||
991 | @item @key{RET} | |
992 | @kindex RET @r{(GDB breakpoints buffer)} | |
993 | @findex gdb-goto-breakpoint | |
994 | Visit the source line for the current breakpoint | |
995 | (@code{gdb-goto-breakpoint}). | |
996 | ||
997 | @item Mouse-2 | |
998 | @kindex Mouse-2 @r{(GDB breakpoints buffer)} | |
999 | Visit the source line for the breakpoint you click on. | |
1000 | @end table | |
1001 | ||
95dbaaea NR |
1002 | When @code{gdb-many-windows} is non-@code{nil}, the breakpoints buffer |
1003 | shares its window with the threads buffer. To switch from one to the | |
1004 | other click with @kbd{mouse-1} on the relevant button in the header | |
1005 | line. | |
1006 | ||
8cf51b2c GM |
1007 | @node Stack Buffer |
1008 | @subsubsection Stack Buffer | |
1009 | ||
1010 | The stack buffer displays a @dfn{call stack}, with one line for each | |
1011 | of the nested subroutine calls (@dfn{stack frames}) now active in the | |
1012 | program. @xref{Backtrace,, Backtraces, gdb, The GNU debugger}. | |
1013 | ||
1014 | @findex gdb-frames-select | |
1015 | An arrow in the fringe points to the selected frame or, if the fringe is | |
1016 | not present, the number of the selected frame is displayed in reverse | |
1017 | contrast. To select a frame in GDB, move point in the stack buffer to | |
1018 | that stack frame and type @key{RET} (@code{gdb-frames-select}), or click | |
1019 | @kbd{Mouse-2} on a stack frame. If the locals buffer is visible, | |
1020 | selecting a stack frame updates it to display the local variables of the | |
1021 | new frame. | |
1022 | ||
1023 | @node Other GDB-UI Buffers | |
1024 | @subsubsection Other Buffers | |
1025 | ||
1026 | @table @asis | |
1027 | @item Input/Output Buffer | |
1028 | @vindex gdb-use-separate-io-buffer | |
1029 | If the variable @code{gdb-use-separate-io-buffer} is non-@code{nil}, | |
1030 | the program being debugged takes its input and displays its output | |
1031 | here. Otherwise it uses the GUD buffer for that. To toggle whether | |
1032 | GUD mode uses this buffer, do @kbd{M-x gdb-use-separate-io-buffer}. | |
1033 | This takes effect when you next restart the program you are debugging. | |
1034 | ||
1035 | The history and replay commands from Shell mode are available here, | |
1036 | as are the commands to send signals to the debugged program. | |
1037 | @xref{Shell Mode}. | |
1038 | ||
1039 | @item Locals Buffer | |
1040 | The locals buffer displays the values of local variables of the | |
1041 | current frame for simple data types (@pxref{Frame Info, Frame Info, | |
1042 | Information on a frame, gdb, The GNU debugger}). Press @key{RET} or | |
1043 | click @kbd{Mouse-2} on the value if you want to edit it. | |
1044 | ||
1045 | Arrays and structures display their type only. With GDB 6.4 or later, | |
1046 | move point to their name and press @key{RET}, or alternatively click | |
1047 | @kbd{Mouse-2} there, to examine their values. With earlier versions | |
1048 | of GDB, use @kbd{Mouse-2} or @key{RET} on the type description | |
1049 | (@samp{[struct/union]} or @samp{[array]}). @xref{Watch Expressions}. | |
1050 | ||
1051 | @item Registers Buffer | |
1052 | @findex toggle-gdb-all-registers | |
1053 | The registers buffer displays the values held by the registers | |
1054 | (@pxref{Registers,,, gdb, The GNU debugger}). Press @key{RET} or | |
1055 | click @kbd{Mouse-2} on a register if you want to edit its value. | |
1056 | With GDB 6.4 or later, recently changed register values display with | |
1057 | @code{font-lock-warning-face}. With earlier versions of GDB, you can | |
1058 | press @key{SPC} to toggle the display of floating point registers | |
1059 | (@code{toggle-gdb-all-registers}). | |
1060 | ||
1061 | @item Assembler Buffer | |
1062 | The assembler buffer displays the current frame as machine code. An | |
1063 | arrow points to the current instruction, and you can set and remove | |
1064 | breakpoints as in a source buffer. Breakpoint icons also appear in | |
1065 | the fringe or margin. | |
1066 | ||
1067 | @item Threads Buffer | |
1068 | @findex gdb-threads-select | |
1069 | The threads buffer displays a summary of all threads currently in your | |
1070 | program (@pxref{Threads, Threads, Debugging programs with multiple | |
1071 | threads, gdb, The GNU debugger}). Move point to any thread in the | |
1072 | list and press @key{RET} to select it (@code{gdb-threads-select}) and | |
1073 | display the associated source in the primary source buffer. | |
1074 | Alternatively, click @kbd{Mouse-2} on a thread to select it. If the | |
1075 | locals buffer is visible, its contents update to display the variables | |
1076 | that are local in the new thread. | |
1077 | ||
95dbaaea | 1078 | When there is more than one main thread and the threads buffer is |
1a19cb6a NR |
1079 | present, Emacs displays the selected thread number in the mode line of |
1080 | many of the GDB-UI Buffers. | |
95dbaaea | 1081 | |
8cf51b2c GM |
1082 | @item Memory Buffer |
1083 | The memory buffer lets you examine sections of program memory | |
1084 | (@pxref{Memory, Memory, Examining memory, gdb, The GNU debugger}). | |
1085 | Click @kbd{Mouse-1} on the appropriate part of the header line to | |
1086 | change the starting address or number of data items that the buffer | |
4a3a621f NR |
1087 | displays. Alternatively, use @kbd{S} or @kbd{N} respectively. Click |
1088 | @kbd{Mouse-3} on the header line to select the display format or unit | |
1089 | size for these data items. | |
8cf51b2c GM |
1090 | @end table |
1091 | ||
1a19cb6a NR |
1092 | When @code{gdb-many-windows} is non-@code{nil}, the threads buffer |
1093 | shares its window with the breakpoints buffer, and the locals buffer | |
1094 | with the registers buffer. To switch from one to the other click with | |
1095 | @kbd{mouse-1} on the relevant button in the header line. | |
1096 | ||
8cf51b2c GM |
1097 | @node Watch Expressions |
1098 | @subsubsection Watch Expressions | |
1099 | @cindex Watching expressions in GDB | |
1100 | ||
1101 | @findex gud-watch | |
1102 | @kindex C-x C-a C-w @r{(GUD)} | |
1103 | If you want to see how a variable changes each time your program | |
1104 | stops, move point into the variable name and click on the watch icon | |
1105 | in the tool bar (@code{gud-watch}) or type @kbd{C-x C-a C-w}. If you | |
1106 | specify a prefix argument, you can enter the variable name in the | |
1107 | minibuffer. | |
1108 | ||
1109 | Each watch expression is displayed in the speedbar. Complex data | |
1110 | types, such as arrays, structures and unions are represented in a tree | |
1111 | format. Leaves and simple data types show the name of the expression | |
1112 | and its value and, when the speedbar frame is selected, display the | |
1113 | type as a tooltip. Higher levels show the name, type and address | |
1114 | value for pointers and just the name and type otherwise. Root expressions | |
1115 | also display the frame address as a tooltip to help identify the frame | |
1116 | in which they were defined. | |
1117 | ||
1118 | To expand or contract a complex data type, click @kbd{Mouse-2} or | |
1119 | press @key{SPC} on the tag to the left of the expression. Emacs asks | |
1120 | for confirmation before expanding the expression if its number of | |
1121 | immediate children exceeds the value of the variable | |
1122 | @code{gdb-max-children}. | |
1123 | ||
1124 | @kindex D @r{(GDB speedbar)} | |
1125 | @findex gdb-var-delete | |
1126 | To delete a complex watch expression, move point to the root | |
1127 | expression in the speedbar and type @kbd{D} (@code{gdb-var-delete}). | |
1128 | ||
1129 | @kindex RET @r{(GDB speedbar)} | |
1130 | @findex gdb-edit-value | |
1131 | To edit a variable with a simple data type, or a simple element of a | |
1132 | complex data type, move point there in the speedbar and type @key{RET} | |
1133 | (@code{gdb-edit-value}). Or you can click @kbd{Mouse-2} on a value to | |
1134 | edit it. Either way, this reads the new value using the minibuffer. | |
1135 | ||
1136 | @vindex gdb-show-changed-values | |
1137 | If you set the variable @code{gdb-show-changed-values} to | |
1138 | non-@code{nil} (the default value), Emacs uses | |
1139 | @code{font-lock-warning-face} to highlight values that have recently | |
1140 | changed and @code{shadow} face to make variables which have gone out of | |
1141 | scope less noticeable. When a variable goes out of scope you can't | |
1142 | edit its value. | |
1143 | ||
975900f9 | 1144 | @vindex gdb-delete-out-of-scope |
32ef39ff NR |
1145 | If the variable @code{gdb-delete-out-of-scope} is non-@code{nil} |
1146 | (the default value), Emacs automatically deletes watch expressions | |
1147 | which go out of scope. Sometimes, when re-entering the same function, | |
975900f9 NR |
1148 | it may be useful to set this value to nil so that you don't need to |
1149 | recreate the watch expression. | |
1150 | ||
8cf51b2c GM |
1151 | @vindex gdb-use-colon-colon-notation |
1152 | If the variable @code{gdb-use-colon-colon-notation} is | |
1153 | non-@code{nil}, Emacs uses the @samp{@var{function}::@var{variable}} | |
1154 | format. This allows the user to display watch expressions which share | |
1155 | the same variable name. The default value is @code{nil}. | |
1156 | ||
1157 | @vindex gdb-speedbar-auto-raise | |
1158 | To automatically raise the speedbar every time the display of watch | |
1159 | expressions updates, set @code{gdb-speedbar-auto-raise} to | |
1160 | non-@code{nil}. This can be useful if you are debugging with a full | |
1161 | screen Emacs frame. | |
1162 | ||
1163 | @node Executing Lisp | |
1164 | @section Executing Lisp Expressions | |
1165 | ||
1166 | Emacs has several different major modes for Lisp and Scheme. They are | |
1167 | the same in terms of editing commands, but differ in the commands for | |
1168 | executing Lisp expressions. Each mode has its own purpose. | |
1169 | ||
1170 | @table @asis | |
1171 | @item Emacs-Lisp mode | |
1172 | The mode for editing source files of programs to run in Emacs Lisp. | |
1173 | This mode defines @kbd{C-M-x} to evaluate the current defun. | |
1174 | @xref{Lisp Libraries}. | |
1175 | @item Lisp Interaction mode | |
1176 | The mode for an interactive session with Emacs Lisp. It defines | |
1177 | @kbd{C-j} to evaluate the sexp before point and insert its value in the | |
1178 | buffer. @xref{Lisp Interaction}. | |
1179 | @item Lisp mode | |
1180 | The mode for editing source files of programs that run in Lisps other | |
1181 | than Emacs Lisp. This mode defines @kbd{C-M-x} to send the current defun | |
1182 | to an inferior Lisp process. @xref{External Lisp}. | |
1183 | @item Inferior Lisp mode | |
1184 | The mode for an interactive session with an inferior Lisp process. | |
1185 | This mode combines the special features of Lisp mode and Shell mode | |
1186 | (@pxref{Shell Mode}). | |
1187 | @item Scheme mode | |
1188 | Like Lisp mode but for Scheme programs. | |
1189 | @item Inferior Scheme mode | |
1190 | The mode for an interactive session with an inferior Scheme process. | |
1191 | @end table | |
1192 | ||
1193 | Most editing commands for working with Lisp programs are in fact | |
1194 | available globally. @xref{Programs}. | |
1195 | ||
1196 | @node Lisp Libraries | |
1197 | @section Libraries of Lisp Code for Emacs | |
1198 | @cindex libraries | |
1199 | @cindex loading Lisp code | |
1200 | ||
1201 | Lisp code for Emacs editing commands is stored in files whose names | |
1202 | conventionally end in @file{.el}. This ending tells Emacs to edit them in | |
1203 | Emacs-Lisp mode (@pxref{Executing Lisp}). | |
1204 | ||
1205 | @cindex byte code | |
1206 | Emacs Lisp code can be compiled into byte-code, which loads faster, | |
1207 | takes up less space, and executes faster. @xref{Byte Compilation,, | |
1208 | Byte Compilation, elisp, the Emacs Lisp Reference Manual}. By | |
1209 | convention, the compiled code for a library goes in a separate file | |
1210 | whose name ends in @samp{.elc}. Thus, the compiled code for | |
1211 | @file{foo.el} goes in @file{foo.elc}. | |
1212 | ||
1213 | @findex load-file | |
1214 | To execute a file of Emacs Lisp code, use @kbd{M-x load-file}. This | |
1215 | command reads a file name using the minibuffer and then executes the | |
1216 | contents of that file as Lisp code. It is not necessary to visit the | |
1217 | file first; in any case, this command reads the file as found on disk, | |
1218 | not text in an Emacs buffer. | |
1219 | ||
1220 | @findex load | |
1221 | @findex load-library | |
1222 | Once a file of Lisp code is installed in the Emacs Lisp library | |
1223 | directories, users can load it using @kbd{M-x load-library}. Programs | |
1224 | can load it by calling @code{load}, a more primitive function that is | |
1225 | similar but accepts some additional arguments. | |
1226 | ||
1227 | @kbd{M-x load-library} differs from @kbd{M-x load-file} in that it | |
1228 | searches a sequence of directories and tries three file names in each | |
1229 | directory. Suppose your argument is @var{lib}; the three names are | |
1230 | @file{@var{lib}.elc}, @file{@var{lib}.el}, and lastly just | |
1231 | @file{@var{lib}}. If @file{@var{lib}.elc} exists, it is by convention | |
1232 | the result of compiling @file{@var{lib}.el}; it is better to load the | |
1233 | compiled file, since it will load and run faster. | |
1234 | ||
1235 | If @code{load-library} finds that @file{@var{lib}.el} is newer than | |
1236 | @file{@var{lib}.elc} file, it issues a warning, because it's likely | |
1237 | that somebody made changes to the @file{.el} file and forgot to | |
1238 | recompile it. Nonetheless, it loads @file{@var{lib}.elc}. This is | |
1239 | because people often leave unfinished edits the source file, and don't | |
1240 | recompile it until they think it is ready to use. | |
1241 | ||
1242 | Because the argument to @code{load-library} is usually not in itself | |
1243 | a valid file name, file name completion is not available. Indeed, when | |
1244 | using this command, you usually do not know exactly what file name | |
1245 | will be used. | |
1246 | ||
1247 | @vindex load-path | |
1248 | The sequence of directories searched by @kbd{M-x load-library} is | |
1249 | specified by the variable @code{load-path}, a list of strings that are | |
1250 | directory names. The default value of the list contains the directories where | |
1251 | the Lisp code for Emacs itself is stored. If you have libraries of | |
1252 | your own, put them in a single directory and add that directory | |
1253 | to @code{load-path}. @code{nil} in this list stands for the current default | |
1254 | directory, but it is probably not a good idea to put @code{nil} in the | |
1255 | list. If you find yourself wishing that @code{nil} were in the list, | |
1256 | most likely what you really want to do is use @kbd{M-x load-file} | |
1257 | this once. | |
1258 | ||
1259 | @cindex autoload | |
1260 | Often you do not have to give any command to load a library, because | |
1261 | the commands defined in the library are set up to @dfn{autoload} that | |
1262 | library. Trying to run any of those commands calls @code{load} to load | |
1263 | the library; this replaces the autoload definitions with the real ones | |
1264 | from the library. | |
1265 | ||
1266 | @vindex load-dangerous-libraries | |
1267 | @cindex Lisp files byte-compiled by XEmacs | |
1268 | By default, Emacs refuses to load compiled Lisp files which were | |
1269 | compiled with XEmacs, a modified versions of Emacs---they can cause | |
1270 | Emacs to crash. Set the variable @code{load-dangerous-libraries} to | |
1271 | @code{t} if you want to try loading them. | |
1272 | ||
1273 | @node Lisp Eval | |
1274 | @section Evaluating Emacs Lisp Expressions | |
1275 | @cindex Emacs-Lisp mode | |
1276 | @cindex mode, Emacs-Lisp | |
1277 | ||
1278 | @findex emacs-lisp-mode | |
1279 | Lisp programs intended to be run in Emacs should be edited in | |
1280 | Emacs-Lisp mode; this happens automatically for file names ending in | |
1281 | @file{.el}. By contrast, Lisp mode itself is used for editing Lisp | |
1282 | programs intended for other Lisp systems. To switch to Emacs-Lisp mode | |
1283 | explicitly, use the command @kbd{M-x emacs-lisp-mode}. | |
1284 | ||
1285 | For testing of Lisp programs to run in Emacs, it is often useful to | |
1286 | evaluate part of the program as it is found in the Emacs buffer. For | |
1287 | example, after changing the text of a Lisp function definition, | |
1288 | evaluating the definition installs the change for future calls to the | |
1289 | function. Evaluation of Lisp expressions is also useful in any kind of | |
1290 | editing, for invoking noninteractive functions (functions that are | |
1291 | not commands). | |
1292 | ||
1293 | @table @kbd | |
1294 | @item M-: | |
1295 | Read a single Lisp expression in the minibuffer, evaluate it, and print | |
1296 | the value in the echo area (@code{eval-expression}). | |
1297 | @item C-x C-e | |
1298 | Evaluate the Lisp expression before point, and print the value in the | |
1299 | echo area (@code{eval-last-sexp}). | |
1300 | @item C-M-x | |
1301 | Evaluate the defun containing or after point, and print the value in | |
1302 | the echo area (@code{eval-defun}). | |
1303 | @item M-x eval-region | |
1304 | Evaluate all the Lisp expressions in the region. | |
1305 | @item M-x eval-buffer | |
1306 | Evaluate all the Lisp expressions in the buffer. | |
1307 | @end table | |
1308 | ||
1309 | @ifinfo | |
1310 | @c This uses ``colon'' instead of a literal `:' because Info cannot | |
1311 | @c cope with a `:' in a menu | |
1312 | @kindex M-@key{colon} | |
1313 | @end ifinfo | |
1314 | @ifnotinfo | |
1315 | @kindex M-: | |
1316 | @end ifnotinfo | |
1317 | @findex eval-expression | |
1318 | @kbd{M-:} (@code{eval-expression}) is the most basic command for evaluating | |
1319 | a Lisp expression interactively. It reads the expression using the | |
1320 | minibuffer, so you can execute any expression on a buffer regardless of | |
1321 | what the buffer contains. When the expression is evaluated, the current | |
1322 | buffer is once again the buffer that was current when @kbd{M-:} was | |
1323 | typed. | |
1324 | ||
1325 | @kindex C-M-x @r{(Emacs-Lisp mode)} | |
1326 | @findex eval-defun | |
1327 | In Emacs-Lisp mode, the key @kbd{C-M-x} is bound to the command | |
1328 | @code{eval-defun}, which parses the defun containing or following point | |
1329 | as a Lisp expression and evaluates it. The value is printed in the echo | |
1330 | area. This command is convenient for installing in the Lisp environment | |
1331 | changes that you have just made in the text of a function definition. | |
1332 | ||
1333 | @kbd{C-M-x} treats @code{defvar} expressions specially. Normally, | |
1334 | evaluating a @code{defvar} expression does nothing if the variable it | |
1335 | defines already has a value. But @kbd{C-M-x} unconditionally resets the | |
1336 | variable to the initial value specified in the @code{defvar} expression. | |
1337 | @code{defcustom} expressions are treated similarly. | |
1338 | This special feature is convenient for debugging Lisp programs. | |
1339 | Typing @kbd{C-M-x} on a @code{defface} expression reinitializes | |
1340 | the face according to the @code{defface} specification. | |
1341 | ||
1342 | @kindex C-x C-e | |
1343 | @findex eval-last-sexp | |
1344 | The command @kbd{C-x C-e} (@code{eval-last-sexp}) evaluates the Lisp | |
1345 | expression preceding point in the buffer, and displays the value in the | |
1346 | echo area. It is available in all major modes, not just Emacs-Lisp | |
1347 | mode. It does not treat @code{defvar} specially. | |
1348 | ||
1349 | When the result of an evaluation is an integer, you can type | |
1350 | @kbd{C-x C-e} a second time to display the value of the integer result | |
1351 | in additional formats (octal, hexadecimal, and character). | |
1352 | ||
1353 | If @kbd{C-x C-e}, or @kbd{M-:} is given a numeric argument, it | |
1354 | inserts the value into the current buffer at point, rather than | |
1355 | displaying it in the echo area. The argument's value does not matter. | |
1356 | @kbd{C-M-x} with a numeric argument instruments the function | |
1357 | definition for Edebug (@pxref{Instrumenting, Instrumenting for Edebug,, elisp, the Emacs Lisp Reference Manual}). | |
1358 | ||
1359 | @findex eval-region | |
1360 | @findex eval-buffer | |
1361 | The most general command for evaluating Lisp expressions from a buffer | |
1362 | is @code{eval-region}. @kbd{M-x eval-region} parses the text of the | |
1363 | region as one or more Lisp expressions, evaluating them one by one. | |
1364 | @kbd{M-x eval-buffer} is similar but evaluates the entire | |
1365 | buffer. This is a reasonable way to install the contents of a file of | |
1366 | Lisp code that you are ready to test. Later, as you find bugs and | |
1367 | change individual functions, use @kbd{C-M-x} on each function that you | |
1368 | change. This keeps the Lisp world in step with the source file. | |
1369 | ||
1370 | @vindex eval-expression-print-level | |
1371 | @vindex eval-expression-print-length | |
1372 | @vindex eval-expression-debug-on-error | |
1373 | The two customizable variables @code{eval-expression-print-level} and | |
1374 | @code{eval-expression-print-length} control the maximum depth and length | |
1375 | of lists to print in the result of the evaluation commands before | |
1376 | abbreviating them. @code{eval-expression-debug-on-error} controls | |
1377 | whether evaluation errors invoke the debugger when these commands are | |
1378 | used; its default is @code{t}. | |
1379 | ||
1380 | @node Lisp Interaction | |
1381 | @section Lisp Interaction Buffers | |
1382 | ||
1383 | The buffer @samp{*scratch*} which is selected when Emacs starts up is | |
1384 | provided for evaluating Lisp expressions interactively inside Emacs. | |
1385 | ||
1386 | The simplest way to use the @samp{*scratch*} buffer is to insert Lisp | |
1387 | expressions and type @kbd{C-j} after each expression. This command | |
1388 | reads the Lisp expression before point, evaluates it, and inserts the | |
1389 | value in printed representation before point. The result is a complete | |
1390 | typescript of the expressions you have evaluated and their values. | |
1391 | ||
1392 | The @samp{*scratch*} buffer's major mode is Lisp Interaction mode, which | |
1393 | is the same as Emacs-Lisp mode except for the binding of @kbd{C-j}. | |
1394 | ||
1395 | @findex lisp-interaction-mode | |
1396 | The rationale for this feature is that Emacs must have a buffer when | |
1397 | it starts up, but that buffer is not useful for editing files since a | |
1398 | new buffer is made for every file that you visit. The Lisp interpreter | |
1399 | typescript is the most useful thing I can think of for the initial | |
1400 | buffer to do. Type @kbd{M-x lisp-interaction-mode} to put the current | |
1401 | buffer in Lisp Interaction mode. | |
1402 | ||
1403 | @findex ielm | |
1404 | An alternative way of evaluating Emacs Lisp expressions interactively | |
1405 | is to use Inferior Emacs-Lisp mode, which provides an interface rather | |
1406 | like Shell mode (@pxref{Shell Mode}) for evaluating Emacs Lisp | |
1407 | expressions. Type @kbd{M-x ielm} to create an @samp{*ielm*} buffer | |
1408 | which uses this mode. For more information see that command's | |
1409 | documentation. | |
1410 | ||
1411 | @node External Lisp | |
1412 | @section Running an External Lisp | |
1413 | ||
1414 | Emacs has facilities for running programs in other Lisp systems. You can | |
1415 | run a Lisp process as an inferior of Emacs, and pass expressions to it to | |
1416 | be evaluated. You can also pass changed function definitions directly from | |
1417 | the Emacs buffers in which you edit the Lisp programs to the inferior Lisp | |
1418 | process. | |
1419 | ||
1420 | @findex run-lisp | |
1421 | @vindex inferior-lisp-program | |
1422 | @kindex C-x C-z | |
1423 | To run an inferior Lisp process, type @kbd{M-x run-lisp}. This runs | |
1424 | the program named @code{lisp}, the same program you would run by typing | |
1425 | @code{lisp} as a shell command, with both input and output going through | |
1426 | an Emacs buffer named @samp{*lisp*}. That is to say, any ``terminal | |
1427 | output'' from Lisp will go into the buffer, advancing point, and any | |
1428 | ``terminal input'' for Lisp comes from text in the buffer. (You can | |
1429 | change the name of the Lisp executable file by setting the variable | |
1430 | @code{inferior-lisp-program}.) | |
1431 | ||
1432 | To give input to Lisp, go to the end of the buffer and type the input, | |
1433 | terminated by @key{RET}. The @samp{*lisp*} buffer is in Inferior Lisp | |
1434 | mode, which combines the special characteristics of Lisp mode with most | |
1435 | of the features of Shell mode (@pxref{Shell Mode}). The definition of | |
1436 | @key{RET} to send a line to a subprocess is one of the features of Shell | |
1437 | mode. | |
1438 | ||
1439 | @findex lisp-mode | |
1440 | For the source files of programs to run in external Lisps, use Lisp | |
1441 | mode. You can switch to this mode with @kbd{M-x lisp-mode}, and it is | |
1442 | used automatically for files whose names end in @file{.l}, | |
1443 | @file{.lsp}, or @file{.lisp}. | |
1444 | ||
1445 | @kindex C-M-x @r{(Lisp mode)} | |
1446 | @findex lisp-eval-defun | |
1447 | When you edit a function in a Lisp program you are running, the easiest | |
1448 | way to send the changed definition to the inferior Lisp process is the key | |
1449 | @kbd{C-M-x}. In Lisp mode, this runs the function @code{lisp-eval-defun}, | |
1450 | which finds the defun around or following point and sends it as input to | |
1451 | the Lisp process. (Emacs can send input to any inferior process regardless | |
1452 | of what buffer is current.) | |
1453 | ||
1454 | Contrast the meanings of @kbd{C-M-x} in Lisp mode (for editing | |
1455 | programs to be run in another Lisp system) and Emacs-Lisp mode (for | |
1456 | editing Lisp programs to be run in Emacs; see @pxref{Lisp Eval}): in | |
1457 | both modes it has the effect of installing the function definition | |
1458 | that point is in, but the way of doing so is different according to | |
1459 | where the relevant Lisp environment is found. | |
1460 | ||
1461 | ||
1462 | @ignore | |
1463 | arch-tag: 9c3c2f71-b332-4144-8500-3ff9945a50ed | |
1464 | @end ignore |