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73804d4b | 1 | @comment -*-texinfo-*- |
969fe9b5 | 2 | @c This is part of the GNU Emacs Lisp Reference Manual. |
fd897522 | 3 | @c Copyright (C) 1992, 1993, 1994, 1998, 1999 Free Software Foundation, Inc. |
969fe9b5 | 4 | @c See the file elisp.texi for copying conditions. |
73804d4b | 5 | |
969fe9b5 RS |
6 | @c This file can also be used by an independent Edebug User |
7 | @c Manual in which case the Edebug node below should be used | |
73804d4b RS |
8 | @c with the following links to the Bugs section and to the top level: |
9 | ||
10 | @c , Bugs and Todo List, Top, Top | |
11 | ||
1911e6e5 | 12 | @node Edebug, Syntax Errors, Debugger, Debugging |
73804d4b RS |
13 | @section Edebug |
14 | @cindex Edebug mode | |
15 | ||
16 | @cindex Edebug | |
17 | Edebug is a source-level debugger for Emacs Lisp programs with which | |
18 | you can: | |
19 | ||
20 | @itemize @bullet | |
21 | @item | |
22 | Step through evaluation, stopping before and after each expression. | |
23 | ||
24 | @item | |
25 | Set conditional or unconditional breakpoints. | |
26 | ||
27 | @item | |
28 | Stop when a specified condition is true (the global break event). | |
29 | ||
30 | @item | |
31 | Trace slow or fast, stopping briefly at each stop point, or | |
32 | at each breakpoint. | |
33 | ||
34 | @item | |
35 | Display expression results and evaluate expressions as if outside of | |
36 | Edebug. | |
37 | ||
38 | @item | |
a9f0a989 | 39 | Automatically re-evaluate a list of expressions and |
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40 | display their results each time Edebug updates the display. |
41 | ||
42 | @item | |
43 | Output trace info on function enter and exit. | |
44 | ||
45 | @item | |
46 | Stop when an error occurs. | |
47 | ||
48 | @item | |
49 | Display a backtrace, omitting Edebug's own frames. | |
50 | ||
51 | @item | |
52 | Specify argument evaluation for macros and defining forms. | |
53 | ||
54 | @item | |
55 | Obtain rudimentary coverage testing and frequency counts. | |
56 | @end itemize | |
57 | ||
58 | The first three sections below should tell you enough about Edebug to | |
59 | enable you to use it. | |
60 | ||
61 | @menu | |
62 | * Using Edebug:: Introduction to use of Edebug. | |
63 | * Instrumenting:: You must instrument your code | |
64 | in order to debug it with Edebug. | |
65 | * Modes: Edebug Execution Modes. Execution modes, stopping more or less often. | |
66 | * Jumping:: Commands to jump to a specified place. | |
67 | * Misc: Edebug Misc. Miscellaneous commands. | |
68 | * Breakpoints:: Setting breakpoints to make the program stop. | |
8241495d | 69 | * Trapping Errors:: Trapping errors with Edebug. |
73804d4b | 70 | * Views: Edebug Views. Views inside and outside of Edebug. |
8241495d | 71 | * Eval: Edebug Eval. Evaluating expressions within Edebug. |
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72 | * Eval List:: Expressions whose values are displayed |
73 | each time you enter Edebug. | |
74 | * Printing in Edebug:: Customization of printing. | |
75 | * Trace Buffer:: How to produce trace output in a buffer. | |
76 | * Coverage Testing:: How to test evaluation coverage. | |
77 | * The Outside Context:: Data that Edebug saves and restores. | |
78 | * Instrumenting Macro Calls:: Specifying how to handle macro calls. | |
79 | * Options: Edebug Options. Option variables for customizing Edebug. | |
80 | @end menu | |
81 | ||
82 | @node Using Edebug | |
83 | @subsection Using Edebug | |
84 | ||
85 | To debug a Lisp program with Edebug, you must first @dfn{instrument} | |
86 | the Lisp code that you want to debug. A simple way to do this is to | |
87 | first move point into the definition of a function or macro and then do | |
88 | @kbd{C-u C-M-x} (@code{eval-defun} with a prefix argument). See | |
89 | @ref{Instrumenting}, for alternative ways to instrument code. | |
90 | ||
91 | Once a function is instrumented, any call to the function activates | |
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92 | Edebug. Depending on which Edebug execution mode you have selected, |
93 | activating Edebug may stop execution and let you step through the | |
94 | function, or it may update the display and continue execution while | |
95 | checking for debugging commands. The default execution mode is step, | |
96 | which stops execution. @xref{Edebug Execution Modes}. | |
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97 | |
98 | Within Edebug, you normally view an Emacs buffer showing the source of | |
99 | the Lisp code you are debugging. This is referred to as the @dfn{source | |
2bdedac1 | 100 | code buffer}, and it is temporarily read-only. |
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101 | |
102 | An arrow at the left margin indicates the line where the function is | |
103 | executing. Point initially shows where within the line the function is | |
104 | executing, but this ceases to be true if you move point yourself. | |
105 | ||
106 | If you instrument the definition of @code{fac} (shown below) and then | |
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107 | execute @code{(fac 3)}, here is what you would normally see. Point is |
108 | at the open-parenthesis before @code{if}. | |
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109 | |
110 | @example | |
111 | (defun fac (n) | |
112 | =>@point{}(if (< 0 n) | |
113 | (* n (fac (1- n))) | |
114 | 1)) | |
115 | @end example | |
116 | ||
117 | @cindex stop points | |
118 | The places within a function where Edebug can stop execution are called | |
119 | @dfn{stop points}. These occur both before and after each subexpression | |
120 | that is a list, and also after each variable reference. | |
8241495d | 121 | Here we use periods to show the stop points in the function |
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122 | @code{fac}: |
123 | ||
124 | @example | |
125 | (defun fac (n) | |
126 | .(if .(< 0 n.). | |
127 | .(* n. .(fac (1- n.).).). | |
128 | 1).) | |
129 | @end example | |
130 | ||
131 | The special commands of Edebug are available in the source code buffer | |
132 | in addition to the commands of Emacs Lisp mode. For example, you can | |
133 | type the Edebug command @key{SPC} to execute until the next stop point. | |
134 | If you type @key{SPC} once after entry to @code{fac}, here is the | |
135 | display you will see: | |
136 | ||
137 | @example | |
138 | (defun fac (n) | |
139 | =>(if @point{}(< 0 n) | |
140 | (* n (fac (1- n))) | |
141 | 1)) | |
142 | @end example | |
143 | ||
144 | When Edebug stops execution after an expression, it displays the | |
145 | expression's value in the echo area. | |
146 | ||
147 | Other frequently used commands are @kbd{b} to set a breakpoint at a stop | |
148 | point, @kbd{g} to execute until a breakpoint is reached, and @kbd{q} to | |
149 | exit Edebug and return to the top-level command loop. Type @kbd{?} to | |
150 | display a list of all Edebug commands. | |
151 | ||
152 | @node Instrumenting | |
153 | @subsection Instrumenting for Edebug | |
154 | ||
155 | In order to use Edebug to debug Lisp code, you must first | |
156 | @dfn{instrument} the code. Instrumenting code inserts additional code | |
87b2d5ff | 157 | into it, to invoke Edebug at the proper places. |
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158 | |
159 | @kindex C-M-x | |
160 | @findex eval-defun (Edebug) | |
161 | Once you have loaded Edebug, the command @kbd{C-M-x} | |
162 | (@code{eval-defun}) is redefined so that when invoked with a prefix | |
163 | argument on a definition, it instruments the definition before | |
164 | evaluating it. (The source code itself is not modified.) If the | |
165 | variable @code{edebug-all-defs} is non-@code{nil}, that inverts the | |
8241495d | 166 | meaning of the prefix argument: in this case, @kbd{C-M-x} instruments the |
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167 | definition @emph{unless} it has a prefix argument. The default value of |
168 | @code{edebug-all-defs} is @code{nil}. The command @kbd{M-x | |
169 | edebug-all-defs} toggles the value of the variable | |
170 | @code{edebug-all-defs}. | |
171 | ||
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172 | @findex eval-region @r{(Edebug)} |
173 | @findex eval-current-buffer @r{(Edebug)} | |
73804d4b RS |
174 | If @code{edebug-all-defs} is non-@code{nil}, then the commands |
175 | @code{eval-region}, @code{eval-current-buffer}, and @code{eval-buffer} | |
176 | also instrument any definitions they evaluate. Similarly, | |
177 | @code{edebug-all-forms} controls whether @code{eval-region} should | |
178 | instrument @emph{any} form, even non-defining forms. This doesn't apply | |
179 | to loading or evaluations in the minibuffer. The command @kbd{M-x | |
180 | edebug-all-forms} toggles this option. | |
181 | ||
182 | @findex edebug-eval-top-level-form | |
969fe9b5 | 183 | Another command, @kbd{M-x edebug-eval-top-level-form}, is available to |
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184 | instrument any top-level form regardless of the values of |
185 | @code{edebug-all-defs} and @code{edebug-all-forms}. | |
73804d4b | 186 | |
969fe9b5 | 187 | While Edebug is active, the command @kbd{I} |
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188 | (@code{edebug-instrument-callee}) instruments the definition of the |
189 | function or macro called by the list form after point, if is not already | |
190 | instrumented. This is possible only if Edebug knows where to find the | |
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191 | source for that function; for this reading, after loading Edebug, |
192 | @code{eval-region} records the position of every definition it | |
193 | evaluates, even if not instrumenting it. See also the @kbd{i} command | |
194 | (@pxref{Jumping}), which steps into the call after instrumenting the | |
195 | function. | |
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196 | |
197 | @cindex special forms (Edebug) | |
198 | @cindex interactive commands (Edebug) | |
199 | @cindex anonymous lambda expressions (Edebug) | |
200 | @cindex Common Lisp (Edebug) | |
969fe9b5 | 201 | @pindex cl.el @r{(Edebug)} |
73804d4b | 202 | @pindex cl-specs.el |
a9f0a989 RS |
203 | Edebug knows how to instrument all the standard special forms, |
204 | @code{interactive} forms with an expression argument, anonymous lambda | |
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205 | expressions, and other defining forms. However, Edebug cannot determine |
206 | on its own what a user-defined macro will do with the arguments of a | |
207 | macro call, so you must provide that information; see @ref{Instrumenting | |
208 | Macro Calls}, for details. | |
73804d4b | 209 | |
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210 | When Edebug is about to instrument code for the first time in a |
211 | session, it runs the hook @code{edebug-setup-hook}, then sets it to | |
8241495d | 212 | @code{nil}. You can use this to load Edebug specifications |
969fe9b5 | 213 | (@pxref{Instrumenting Macro Calls}) associated with a package you are |
8241495d | 214 | using, but only when you use Edebug. |
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215 | |
216 | @findex eval-expression @r{(Edebug)} | |
a9f0a989 | 217 | To remove instrumentation from a definition, simply re-evaluate its |
73804d4b | 218 | definition in a way that does not instrument. There are two ways of |
87b2d5ff | 219 | evaluating forms that never instrument them: from a file with |
73804d4b | 220 | @code{load}, and from the minibuffer with @code{eval-expression} |
bfe721d1 | 221 | (@kbd{M-:}). |
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222 | |
223 | If Edebug detects a syntax error while instrumenting, it leaves point | |
224 | at the erroneous code and signals an @code{invalid-read-syntax} error. | |
225 | ||
226 | @xref{Edebug Eval}, for other evaluation functions available | |
227 | inside of Edebug. | |
228 | ||
229 | @node Edebug Execution Modes | |
230 | @subsection Edebug Execution Modes | |
231 | ||
232 | @cindex Edebug execution modes | |
233 | Edebug supports several execution modes for running the program you are | |
234 | debugging. We call these alternatives @dfn{Edebug execution modes}; do | |
87b2d5ff | 235 | not confuse them with major or minor modes. The current Edebug execution mode |
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236 | determines how far Edebug continues execution before stopping---whether |
237 | it stops at each stop point, or continues to the next breakpoint, for | |
238 | example---and how much Edebug displays the progress of the evaluation | |
239 | before it stops. | |
240 | ||
241 | Normally, you specify the Edebug execution mode by typing a command to | |
242 | continue the program in a certain mode. Here is a table of these | |
8241495d | 243 | commands; all except for @kbd{S} resume execution of the program, at |
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244 | least for a certain distance. |
245 | ||
246 | @table @kbd | |
247 | @item S | |
8241495d | 248 | Stop: don't execute any more of the program, but wait for more |
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249 | Edebug commands (@code{edebug-stop}). |
250 | ||
251 | @item @key{SPC} | |
252 | Step: stop at the next stop point encountered (@code{edebug-step-mode}). | |
253 | ||
254 | @item n | |
255 | Next: stop at the next stop point encountered after an expression | |
256 | (@code{edebug-next-mode}). Also see @code{edebug-forward-sexp} in | |
257 | @ref{Edebug Misc}. | |
258 | ||
259 | @item t | |
260 | Trace: pause one second at each Edebug stop point (@code{edebug-trace-mode}). | |
261 | ||
262 | @item T | |
263 | Rapid trace: update the display at each stop point, but don't actually | |
264 | pause (@code{edebug-Trace-fast-mode}). | |
265 | ||
266 | @item g | |
267 | Go: run until the next breakpoint (@code{edebug-go-mode}). @xref{Breakpoints}. | |
268 | ||
269 | @item c | |
270 | Continue: pause one second at each breakpoint, and then continue | |
271 | (@code{edebug-continue-mode}). | |
272 | ||
273 | @item C | |
274 | Rapid continue: move point to each breakpoint, but don't pause | |
275 | (@code{edebug-Continue-fast-mode}). | |
276 | ||
277 | @item G | |
278 | Go non-stop: ignore breakpoints (@code{edebug-Go-nonstop-mode}). You | |
279 | can still stop the program by typing @kbd{S}, or any editing command. | |
280 | @end table | |
281 | ||
282 | In general, the execution modes earlier in the above list run the | |
87b2d5ff | 283 | program more slowly or stop sooner than the modes later in the list. |
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284 | |
285 | While executing or tracing, you can interrupt the execution by typing | |
286 | any Edebug command. Edebug stops the program at the next stop point and | |
87b2d5ff RS |
287 | then executes the command you typed. For example, typing @kbd{t} during |
288 | execution switches to trace mode at the next stop point. You can use | |
289 | @kbd{S} to stop execution without doing anything else. | |
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290 | |
291 | If your function happens to read input, a character you type intending | |
292 | to interrupt execution may be read by the function instead. You can | |
293 | avoid such unintended results by paying attention to when your program | |
294 | wants input. | |
295 | ||
296 | @cindex keyboard macros (Edebug) | |
297 | Keyboard macros containing the commands in this section do not | |
298 | completely work: exiting from Edebug, to resume the program, loses track | |
299 | of the keyboard macro. This is not easy to fix. Also, defining or | |
300 | executing a keyboard macro outside of Edebug does not affect commands | |
8241495d | 301 | inside Edebug. This is usually an advantage. See also the |
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302 | @code{edebug-continue-kbd-macro} option (@pxref{Edebug Options}). |
303 | ||
304 | When you enter a new Edebug level, the initial execution mode comes from | |
305 | the value of the variable @code{edebug-initial-mode}. By default, this | |
306 | specifies step mode. Note that you may reenter the same Edebug level | |
307 | several times if, for example, an instrumented function is called | |
308 | several times from one command. | |
309 | ||
310 | ||
311 | @node Jumping | |
312 | @subsection Jumping | |
313 | ||
314 | The commands described in this section execute until they reach a | |
315 | specified location. All except @kbd{i} make a temporary breakpoint to | |
316 | establish the place to stop, then switch to go mode. Any other | |
317 | breakpoint reached before the intended stop point will also stop | |
318 | execution. @xref{Breakpoints}, for the details on breakpoints. | |
319 | ||
320 | These commands may fail to work as expected in case of nonlocal exit, | |
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321 | as that can bypass the temporary breakpoint where you expected the |
322 | program to stop. | |
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323 | |
324 | @table @kbd | |
325 | @item h | |
326 | Proceed to the stop point near where point is (@code{edebug-goto-here}). | |
327 | ||
328 | @item f | |
329 | Run the program forward over one expression | |
330 | (@code{edebug-forward-sexp}). | |
331 | ||
332 | @item o | |
333 | Run the program until the end of the containing sexp. | |
334 | ||
335 | @item i | |
336 | Step into the function or macro called by the form after point. | |
337 | @end table | |
338 | ||
339 | The @kbd{h} command proceeds to the stop point near the current location | |
a9f0a989 RS |
340 | of point, using a temporary breakpoint. See @ref{Breakpoints}, for more |
341 | information about breakpoints. | |
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342 | |
343 | The @kbd{f} command runs the program forward over one expression. More | |
344 | precisely, it sets a temporary breakpoint at the position that | |
345 | @kbd{C-M-f} would reach, then executes in go mode so that the program | |
346 | will stop at breakpoints. | |
347 | ||
348 | With a prefix argument @var{n}, the temporary breakpoint is placed | |
349 | @var{n} sexps beyond point. If the containing list ends before @var{n} | |
350 | more elements, then the place to stop is after the containing | |
351 | expression. | |
352 | ||
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353 | You must check that the position @kbd{C-M-f} finds is a place that the |
354 | program will really get to. In @code{cond}, for example, this may not | |
355 | be true. | |
73804d4b | 356 | |
8241495d RS |
357 | For flexibility, the @kbd{f} command does @code{forward-sexp} starting |
358 | at point, rather than at the stop point. If you want to execute one | |
359 | expression @emph{from the current stop point}, first type @kbd{w}, to | |
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360 | move point there, and then type @kbd{f}. |
361 | ||
362 | The @kbd{o} command continues ``out of'' an expression. It places a | |
363 | temporary breakpoint at the end of the sexp containing point. If the | |
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364 | containing sexp is a function definition itself, @kbd{o} continues until |
365 | just before the last sexp in the definition. If that is where you are | |
366 | now, it returns from the function and then stops. In other words, this | |
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367 | command does not exit the currently executing function unless you are |
368 | positioned after the last sexp. | |
369 | ||
370 | The @kbd{i} command steps into the function or macro called by the list | |
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371 | form after point, and stops at its first stop point. Note that the form |
372 | need not be the one about to be evaluated. But if the form is a | |
373 | function call about to be evaluated, remember to use this command before | |
374 | any of the arguments are evaluated, since otherwise it will be too late. | |
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375 | |
376 | The @kbd{i} command instruments the function or macro it's supposed to | |
377 | step into, if it isn't instrumented already. This is convenient, but keep | |
378 | in mind that the function or macro remains instrumented unless you explicitly | |
379 | arrange to deinstrument it. | |
380 | ||
381 | @node Edebug Misc | |
382 | @subsection Miscellaneous Edebug Commands | |
383 | ||
384 | Some miscellaneous Edebug commands are described here. | |
385 | ||
386 | @table @kbd | |
387 | @item ? | |
388 | Display the help message for Edebug (@code{edebug-help}). | |
389 | ||
390 | @item C-] | |
391 | Abort one level back to the previous command level | |
392 | (@code{abort-recursive-edit}). | |
393 | ||
394 | @item q | |
395 | Return to the top level editor command loop (@code{top-level}). This | |
396 | exits all recursive editing levels, including all levels of Edebug | |
397 | activity. However, instrumented code protected with | |
398 | @code{unwind-protect} or @code{condition-case} forms may resume | |
399 | debugging. | |
400 | ||
401 | @item Q | |
8241495d | 402 | Like @kbd{q}, but don't stop even for protected code |
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403 | (@code{top-level-nonstop}). |
404 | ||
405 | @item r | |
406 | Redisplay the most recently known expression result in the echo area | |
407 | (@code{edebug-previous-result}). | |
408 | ||
409 | @item d | |
410 | Display a backtrace, excluding Edebug's own functions for clarity | |
411 | (@code{edebug-backtrace}). | |
412 | ||
413 | You cannot use debugger commands in the backtrace buffer in Edebug as | |
414 | you would in the standard debugger. | |
415 | ||
416 | The backtrace buffer is killed automatically when you continue | |
417 | execution. | |
418 | @end table | |
419 | ||
8241495d RS |
420 | You can invoke commands from Edebug that activate Edebug again |
421 | recursively. Whenever Edebug is active, you can quit to the top level | |
422 | with @kbd{q} or abort one recursive edit level with @kbd{C-]}. You can | |
423 | display a backtrace of all the pending evaluations with @kbd{d}. | |
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424 | |
425 | @node Breakpoints | |
426 | @subsection Breakpoints | |
427 | ||
428 | @cindex breakpoints | |
8241495d | 429 | Edebug's step mode stops execution when the next stop point is reached. |
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430 | There are three other ways to stop Edebug execution once it has started: |
431 | breakpoints, the global break condition, and source breakpoints. | |
432 | ||
433 | While using Edebug, you can specify @dfn{breakpoints} in the program you | |
8241495d | 434 | are testing: these are places where execution should stop. You can set a |
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435 | breakpoint at any stop point, as defined in @ref{Using Edebug}. For |
436 | setting and unsetting breakpoints, the stop point that is affected is | |
437 | the first one at or after point in the source code buffer. Here are the | |
438 | Edebug commands for breakpoints: | |
439 | ||
440 | @table @kbd | |
441 | @item b | |
442 | Set a breakpoint at the stop point at or after point | |
443 | (@code{edebug-set-breakpoint}). If you use a prefix argument, the | |
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444 | breakpoint is temporary---it turns off the first time it stops the |
445 | program. | |
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446 | |
447 | @item u | |
448 | Unset the breakpoint (if any) at the stop point at or after | |
449 | point (@code{edebug-unset-breakpoint}). | |
450 | ||
451 | @item x @var{condition} @key{RET} | |
452 | Set a conditional breakpoint which stops the program only if | |
453 | @var{condition} evaluates to a non-@code{nil} value | |
454 | (@code{edebug-set-conditional-breakpoint}). With a prefix argument, the | |
455 | breakpoint is temporary. | |
456 | ||
457 | @item B | |
9e2b495b | 458 | Move point to the next breakpoint in the current definition |
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459 | (@code{edebug-next-breakpoint}). |
460 | @end table | |
461 | ||
462 | While in Edebug, you can set a breakpoint with @kbd{b} and unset one | |
463 | with @kbd{u}. First move point to the Edebug stop point of your choice, | |
464 | then type @kbd{b} or @kbd{u} to set or unset a breakpoint there. | |
465 | Unsetting a breakpoint where none has been set has no effect. | |
466 | ||
8241495d RS |
467 | Re-evaluating or reinstrumenting a definition removes all of its |
468 | previous breakpoints. | |
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469 | |
470 | A @dfn{conditional breakpoint} tests a condition each time the program | |
471 | gets there. Any errors that occur as a result of evaluating the | |
472 | condition are ignored, as if the result were @code{nil}. To set a | |
473 | conditional breakpoint, use @kbd{x}, and specify the condition | |
474 | expression in the minibuffer. Setting a conditional breakpoint at a | |
475 | stop point that has a previously established conditional breakpoint puts | |
476 | the previous condition expression in the minibuffer so you can edit it. | |
477 | ||
478 | You can make a conditional or unconditional breakpoint | |
969fe9b5 | 479 | @dfn{temporary} by using a prefix argument with the command to set the |
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480 | breakpoint. When a temporary breakpoint stops the program, it is |
481 | automatically unset. | |
482 | ||
8241495d | 483 | Edebug always stops or pauses at a breakpoint, except when the Edebug |
73804d4b RS |
484 | mode is Go-nonstop. In that mode, it ignores breakpoints entirely. |
485 | ||
486 | To find out where your breakpoints are, use the @kbd{B} command, which | |
87b2d5ff RS |
487 | moves point to the next breakpoint following point, within the same |
488 | function, or to the first breakpoint if there are no following | |
489 | breakpoints. This command does not continue execution---it just moves | |
490 | point in the buffer. | |
73804d4b RS |
491 | |
492 | @menu | |
493 | * Global Break Condition:: Breaking on an event. | |
494 | * Source Breakpoints:: Embedding breakpoints in source code. | |
495 | @end menu | |
496 | ||
497 | ||
498 | @node Global Break Condition | |
499 | @subsubsection Global Break Condition | |
500 | ||
501 | @cindex stopping on events | |
502 | @cindex global break condition | |
503 | A @dfn{global break condition} stops execution when a specified | |
504 | condition is satisfied, no matter where that may occur. Edebug | |
8241495d | 505 | evaluates the global break condition at every stop point; if it |
73804d4b RS |
506 | evaluates to a non-@code{nil} value, then execution stops or pauses |
507 | depending on the execution mode, as if a breakpoint had been hit. If | |
508 | evaluating the condition gets an error, execution does not stop. | |
509 | ||
510 | @findex edebug-set-global-break-condition | |
9e2b495b RS |
511 | The condition expression is stored in |
512 | @code{edebug-global-break-condition}. You can specify a new expression | |
513 | using the @kbd{X} command (@code{edebug-set-global-break-condition}). | |
73804d4b RS |
514 | |
515 | The global break condition is the simplest way to find where in your | |
516 | code some event occurs, but it makes code run much more slowly. So you | |
517 | should reset the condition to @code{nil} when not using it. | |
518 | ||
519 | @node Source Breakpoints | |
520 | @subsubsection Source Breakpoints | |
521 | ||
522 | @findex edebug | |
523 | @cindex source breakpoints | |
524 | All breakpoints in a definition are forgotten each time you | |
8241495d RS |
525 | reinstrument it. If you wish to make a breakpoint that won't be |
526 | forgotten, you can write a @dfn{source breakpoint}, which is simply a | |
527 | call to the function @code{edebug} in your source code. You can, of | |
528 | course, make such a call conditional. For example, in the @code{fac} | |
529 | function, you can insert the first line as shown below, to stop when the | |
530 | argument reaches zero: | |
73804d4b RS |
531 | |
532 | @example | |
533 | (defun fac (n) | |
534 | (if (= n 0) (edebug)) | |
535 | (if (< 0 n) | |
536 | (* n (fac (1- n))) | |
537 | 1)) | |
538 | @end example | |
539 | ||
969fe9b5 | 540 | When the @code{fac} definition is instrumented and the function is |
73804d4b RS |
541 | called, the call to @code{edebug} acts as a breakpoint. Depending on |
542 | the execution mode, Edebug stops or pauses there. | |
543 | ||
969fe9b5 | 544 | If no instrumented code is being executed when @code{edebug} is called, |
73804d4b RS |
545 | that function calls @code{debug}. |
546 | @c This may not be a good idea anymore. | |
547 | ||
548 | @node Trapping Errors | |
549 | @subsection Trapping Errors | |
550 | ||
969fe9b5 RS |
551 | Emacs normally displays an error message when an error is signaled and |
552 | not handled with @code{condition-case}. While Edebug is active and | |
553 | executing instrumented code, it normally responds to all unhandled | |
554 | errors. You can customize this with the options @code{edebug-on-error} | |
555 | and @code{edebug-on-quit}; see @ref{Edebug Options}. | |
73804d4b | 556 | |
969fe9b5 | 557 | When Edebug responds to an error, it shows the last stop point |
73804d4b | 558 | encountered before the error. This may be the location of a call to a |
8241495d | 559 | function which was not instrumented, and within which the error actually |
73804d4b RS |
560 | occurred. For an unbound variable error, the last known stop point |
561 | might be quite distant from the offending variable reference. In that | |
8241495d | 562 | case, you might want to display a full backtrace (@pxref{Edebug Misc}). |
73804d4b | 563 | |
87b2d5ff | 564 | @c Edebug should be changed for the following: -- dan |
969fe9b5 | 565 | If you change @code{debug-on-error} or @code{debug-on-quit} while |
73804d4b RS |
566 | Edebug is active, these changes will be forgotten when Edebug becomes |
567 | inactive. Furthermore, during Edebug's recursive edit, these variables | |
568 | are bound to the values they had outside of Edebug. | |
569 | ||
73804d4b RS |
570 | @node Edebug Views |
571 | @subsection Edebug Views | |
572 | ||
969fe9b5 | 573 | These Edebug commands let you view aspects of the buffer and window |
a9f0a989 | 574 | status as they were before entry to Edebug. The outside window |
87b2d5ff RS |
575 | configuration is the collection of windows and contents that were in |
576 | effect outside of Edebug. | |
73804d4b RS |
577 | |
578 | @table @kbd | |
579 | @item v | |
87b2d5ff RS |
580 | Temporarily view the outside window configuration |
581 | (@code{edebug-view-outside}). | |
73804d4b RS |
582 | |
583 | @item p | |
584 | Temporarily display the outside current buffer with point at its outside | |
585 | position (@code{edebug-bounce-point}). With a prefix argument @var{n}, | |
586 | pause for @var{n} seconds instead. | |
587 | ||
588 | @item w | |
1911e6e5 RS |
589 | Move point back to the current stop point in the source code buffer |
590 | (@code{edebug-where}). | |
591 | ||
592 | If you use this command in a different window displaying the same | |
593 | buffer, that window will be used instead to display the current | |
594 | definition in the future. | |
73804d4b RS |
595 | |
596 | @item W | |
87b2d5ff RS |
597 | @c Its function is not simply to forget the saved configuration -- dan |
598 | Toggle whether Edebug saves and restores the outside window | |
599 | configuration (@code{edebug-toggle-save-windows}). | |
600 | ||
601 | With a prefix argument, @code{W} only toggles saving and restoring of | |
602 | the selected window. To specify a window that is not displaying the | |
603 | source code buffer, you must use @kbd{C-x X W} from the global keymap. | |
73804d4b RS |
604 | @end table |
605 | ||
969fe9b5 | 606 | You can view the outside window configuration with @kbd{v} or just |
73804d4b RS |
607 | bounce to the point in the current buffer with @kbd{p}, even if |
608 | it is not normally displayed. After moving point, you may wish to jump | |
609 | back to the stop point with @kbd{w} from a source code buffer. | |
610 | ||
969fe9b5 | 611 | Each time you use @kbd{W} to turn saving @emph{off}, Edebug forgets the |
87b2d5ff RS |
612 | saved outside window configuration---so that even if you turn saving |
613 | back @emph{on}, the current window configuration remains unchanged when | |
614 | you next exit Edebug (by continuing the program). However, the | |
615 | automatic redisplay of @samp{*edebug*} and @samp{*edebug-trace*} may | |
616 | conflict with the buffers you wish to see unless you have enough windows | |
617 | open. | |
73804d4b RS |
618 | |
619 | @node Edebug Eval | |
620 | @subsection Evaluation | |
621 | ||
8241495d RS |
622 | While within Edebug, you can evaluate expressions ``as if'' Edebug |
623 | were not running. Edebug tries to be invisible to the expression's | |
73804d4b | 624 | evaluation and printing. Evaluation of expressions that cause side |
8241495d RS |
625 | effects will work as expected, except for changes to data that Edebug |
626 | explicitly saves and restores. @xref{The Outside Context}, for details | |
627 | on this process. | |
73804d4b RS |
628 | |
629 | @table @kbd | |
630 | @item e @var{exp} @key{RET} | |
631 | Evaluate expression @var{exp} in the context outside of Edebug | |
632 | (@code{edebug-eval-expression}). That is, Edebug tries to minimize its | |
633 | interference with the evaluation. | |
634 | ||
bfe721d1 | 635 | @item M-: @var{exp} @key{RET} |
73804d4b RS |
636 | Evaluate expression @var{exp} in the context of Edebug itself. |
637 | ||
638 | @item C-x C-e | |
639 | Evaluate the expression before point, in the context outside of Edebug | |
640 | (@code{edebug-eval-last-sexp}). | |
641 | @end table | |
642 | ||
643 | @cindex lexical binding (Edebug) | |
969fe9b5 | 644 | Edebug supports evaluation of expressions containing references to |
73804d4b RS |
645 | lexically bound symbols created by the following constructs in |
646 | @file{cl.el} (version 2.03 or later): @code{lexical-let}, | |
647 | @code{macrolet}, and @code{symbol-macrolet}. | |
648 | ||
73804d4b RS |
649 | @node Eval List |
650 | @subsection Evaluation List Buffer | |
651 | ||
969fe9b5 | 652 | You can use the @dfn{evaluation list buffer}, called @samp{*edebug*}, to |
73804d4b RS |
653 | evaluate expressions interactively. You can also set up the |
654 | @dfn{evaluation list} of expressions to be evaluated automatically each | |
655 | time Edebug updates the display. | |
656 | ||
657 | @table @kbd | |
658 | @item E | |
659 | Switch to the evaluation list buffer @samp{*edebug*} | |
660 | (@code{edebug-visit-eval-list}). | |
661 | @end table | |
662 | ||
969fe9b5 | 663 | In the @samp{*edebug*} buffer you can use the commands of Lisp |
73804d4b RS |
664 | Interaction mode (@pxref{Lisp Interaction,,, emacs, The GNU Emacs |
665 | Manual}) as well as these special commands: | |
666 | ||
667 | @table @kbd | |
969fe9b5 | 668 | @item C-j |
73804d4b RS |
669 | Evaluate the expression before point, in the outside context, and insert |
670 | the value in the buffer (@code{edebug-eval-print-last-sexp}). | |
671 | ||
672 | @item C-x C-e | |
673 | Evaluate the expression before point, in the context outside of Edebug | |
674 | (@code{edebug-eval-last-sexp}). | |
675 | ||
676 | @item C-c C-u | |
87b2d5ff | 677 | Build a new evaluation list from the contents of the buffer |
73804d4b RS |
678 | (@code{edebug-update-eval-list}). |
679 | ||
680 | @item C-c C-d | |
681 | Delete the evaluation list group that point is in | |
682 | (@code{edebug-delete-eval-item}). | |
683 | ||
684 | @item C-c C-w | |
685 | Switch back to the source code buffer at the current stop point | |
686 | (@code{edebug-where}). | |
687 | @end table | |
688 | ||
969fe9b5 RS |
689 | You can evaluate expressions in the evaluation list window with |
690 | @kbd{C-j} or @kbd{C-x C-e}, just as you would in @samp{*scratch*}; | |
73804d4b RS |
691 | but they are evaluated in the context outside of Edebug. |
692 | ||
969fe9b5 | 693 | The expressions you enter interactively (and their results) are lost |
73804d4b RS |
694 | when you continue execution; but you can set up an @dfn{evaluation list} |
695 | consisting of expressions to be evaluated each time execution stops. | |
696 | ||
697 | @cindex evaluation list group | |
969fe9b5 | 698 | To do this, write one or more @dfn{evaluation list groups} in the |
73804d4b RS |
699 | evaluation list buffer. An evaluation list group consists of one or |
700 | more Lisp expressions. Groups are separated by comment lines. | |
701 | ||
969fe9b5 | 702 | The command @kbd{C-c C-u} (@code{edebug-update-eval-list}) rebuilds the |
73804d4b | 703 | evaluation list, scanning the buffer and using the first expression of |
87b2d5ff RS |
704 | each group. (The idea is that the second expression of the group is the |
705 | value previously computed and displayed.) | |
73804d4b | 706 | |
969fe9b5 | 707 | Each entry to Edebug redisplays the evaluation list by inserting each |
87b2d5ff RS |
708 | expression in the buffer, followed by its current value. It also |
709 | inserts comment lines so that each expression becomes its own group. | |
710 | Thus, if you type @kbd{C-c C-u} again without changing the buffer text, | |
711 | the evaluation list is effectively unchanged. | |
73804d4b | 712 | |
969fe9b5 | 713 | If an error occurs during an evaluation from the evaluation list, the |
73804d4b RS |
714 | error message is displayed in a string as if it were the result. |
715 | Therefore, expressions that use variables not currently valid do not | |
716 | interrupt your debugging. | |
717 | ||
969fe9b5 | 718 | Here is an example of what the evaluation list window looks like after |
73804d4b RS |
719 | several expressions have been added to it: |
720 | ||
721 | @smallexample | |
722 | (current-buffer) | |
723 | #<buffer *scratch*> | |
724 | ;--------------------------------------------------------------- | |
725 | (selected-window) | |
726 | #<window 16 on *scratch*> | |
727 | ;--------------------------------------------------------------- | |
728 | (point) | |
729 | 196 | |
730 | ;--------------------------------------------------------------- | |
731 | bad-var | |
732 | "Symbol's value as variable is void: bad-var" | |
733 | ;--------------------------------------------------------------- | |
734 | (recursion-depth) | |
735 | 0 | |
736 | ;--------------------------------------------------------------- | |
737 | this-command | |
738 | eval-last-sexp | |
739 | ;--------------------------------------------------------------- | |
740 | @end smallexample | |
741 | ||
742 | To delete a group, move point into it and type @kbd{C-c C-d}, or simply | |
743 | delete the text for the group and update the evaluation list with | |
744 | @kbd{C-c C-u}. To add a new expression to the evaluation list, insert | |
8241495d RS |
745 | the expression at a suitable place, insert a new comment line, then type |
746 | @kbd{C-c C-u}. You need not insert dashes in the comment line---its | |
747 | contents don't matter. | |
73804d4b RS |
748 | |
749 | After selecting @samp{*edebug*}, you can return to the source code | |
750 | buffer with @kbd{C-c C-w}. The @samp{*edebug*} buffer is killed when | |
751 | you continue execution, and recreated next time it is needed. | |
752 | ||
73804d4b RS |
753 | @node Printing in Edebug |
754 | @subsection Printing in Edebug | |
755 | ||
756 | @cindex printing (Edebug) | |
757 | @cindex printing circular structures | |
758 | @pindex cust-print | |
759 | If an expression in your program produces a value containing circular | |
760 | list structure, you may get an error when Edebug attempts to print it. | |
761 | ||
73804d4b RS |
762 | One way to cope with circular structure is to set @code{print-length} |
763 | or @code{print-level} to truncate the printing. Edebug does this for | |
764 | you; it binds @code{print-length} and @code{print-level} to 50 if they | |
765 | were @code{nil}. (Actually, the variables @code{edebug-print-length} | |
766 | and @code{edebug-print-level} specify the values to use within Edebug.) | |
767 | @xref{Output Variables}. | |
768 | ||
969fe9b5 | 769 | @defopt edebug-print-length |
8241495d RS |
770 | If non-@code{nil}, Edebug binds @code{print-length} to this value while |
771 | printing results. The default value is @code{50}. | |
969fe9b5 RS |
772 | @end defopt |
773 | ||
774 | @defopt edebug-print-level | |
8241495d RS |
775 | If non-@code{nil}, Edebug binds @code{print-level} to this value while |
776 | printing results. The default value is @code{50}. | |
969fe9b5 RS |
777 | @end defopt |
778 | ||
73804d4b | 779 | You can also print circular structures and structures that share |
8241495d RS |
780 | elements more informatively by binding @code{print-circle} |
781 | to a non-@code{nil} value. | |
73804d4b RS |
782 | |
783 | Here is an example of code that creates a circular structure: | |
784 | ||
785 | @example | |
786 | (setq a '(x y)) | |
a9f0a989 | 787 | (setcar a a) |
73804d4b RS |
788 | @end example |
789 | ||
790 | @noindent | |
791 | Custom printing prints this as @samp{Result: #1=(#1# y)}. The | |
792 | @samp{#1=} notation labels the structure that follows it with the label | |
a9f0a989 | 793 | @samp{1}, and the @samp{#1#} notation references the previously labeled |
73804d4b RS |
794 | structure. This notation is used for any shared elements of lists or |
795 | vectors. | |
796 | ||
969fe9b5 | 797 | @defopt edebug-print-circle |
8241495d RS |
798 | If non-@code{nil}, Edebug binds @code{print-circle} to this value while |
799 | printing results. The default value is @code{nil}. | |
969fe9b5 RS |
800 | @end defopt |
801 | ||
73804d4b RS |
802 | Other programs can also use custom printing; see @file{cust-print.el} |
803 | for details. | |
804 | ||
805 | @node Trace Buffer | |
806 | @subsection Trace Buffer | |
807 | @cindex trace buffer | |
808 | ||
87b2d5ff | 809 | Edebug can record an execution trace, storing it in a buffer named |
73804d4b RS |
810 | @samp{*edebug-trace*}. This is a log of function calls and returns, |
811 | showing the function names and their arguments and values. To enable | |
812 | trace recording, set @code{edebug-trace} to a non-@code{nil} value. | |
813 | ||
814 | Making a trace buffer is not the same thing as using trace execution | |
815 | mode (@pxref{Edebug Execution Modes}). | |
816 | ||
817 | When trace recording is enabled, each function entry and exit adds | |
8241495d RS |
818 | lines to the trace buffer. A function entry record consists of |
819 | @samp{::::@{}, followed by the function name and argument values. A | |
820 | function exit record consists of @samp{::::@}}, followed by the function | |
73804d4b RS |
821 | name and result of the function. |
822 | ||
823 | The number of @samp{:}s in an entry shows its recursion depth. You | |
824 | can use the braces in the trace buffer to find the matching beginning or | |
825 | end of function calls. | |
826 | ||
827 | @findex edebug-print-trace-before | |
828 | @findex edebug-print-trace-after | |
829 | You can customize trace recording for function entry and exit by | |
830 | redefining the functions @code{edebug-print-trace-before} and | |
831 | @code{edebug-print-trace-after}. | |
832 | ||
833 | @defmac edebug-tracing string body@dots{} | |
834 | This macro requests additional trace information around the execution | |
835 | of the @var{body} forms. The argument @var{string} specifies text | |
8241495d | 836 | to put in the trace buffer. All the arguments are evaluated, and |
73804d4b RS |
837 | @code{edebug-tracing} returns the value of the last form in @var{body}. |
838 | @end defmac | |
839 | ||
840 | @defun edebug-trace format-string &rest format-args | |
841 | This function inserts text in the trace buffer. It computes the text | |
842 | with @code{(apply 'format @var{format-string} @var{format-args})}. | |
87b2d5ff | 843 | It also appends a newline to separate entries. |
73804d4b RS |
844 | @end defun |
845 | ||
1911e6e5 RS |
846 | @code{edebug-tracing} and @code{edebug-trace} insert lines in the |
847 | trace buffer whenever they are called, even if Edebug is not active. | |
848 | Adding text to the trace buffer also scrolls its window to show the last | |
849 | lines inserted. | |
73804d4b | 850 | |
73804d4b RS |
851 | @node Coverage Testing |
852 | @subsection Coverage Testing | |
853 | ||
854 | @cindex coverage testing | |
855 | @cindex frequency counts | |
856 | @cindex performance analysis | |
857 | Edebug provides rudimentary coverage testing and display of execution | |
1911e6e5 RS |
858 | frequency. |
859 | ||
860 | Coverage testing works by comparing the result of each expression with | |
861 | the previous result; each form in the program is considered ``covered'' | |
862 | if it has returned two different values since you began testing coverage | |
863 | in the current Emacs session. Thus, to do coverage testing on your | |
864 | program, execute it under various conditions and note whether it behaves | |
865 | correctly; Edebug will tell you when you have tried enough different | |
866 | conditions that each form has returned two different values. | |
867 | ||
868 | Coverage testing makes execution slower, so it is only done if | |
ebc6903b RS |
869 | @code{edebug-test-coverage} is non-@code{nil}. Frequency counting is |
870 | performed for all execution of an instrumented function, even if the | |
871 | execution mode is Go-nonstop, and regardless of whether coverage testing | |
872 | is enabled. | |
1911e6e5 RS |
873 | |
874 | Use @kbd{M-x edebug-display-freq-count} to display both the | |
a9f0a989 | 875 | coverage information and the frequency counts for a definition. |
73804d4b RS |
876 | |
877 | @deffn Command edebug-display-freq-count | |
878 | This command displays the frequency count data for each line of the | |
879 | current definition. | |
880 | ||
969fe9b5 RS |
881 | The frequency counts appear as comment lines after each line of code, |
882 | and you can undo all insertions with one @code{undo} command. The | |
883 | counts appear under the @samp{(} before an expression or the @samp{)} | |
a9f0a989 RS |
884 | after an expression, or on the last character of a variable. To |
885 | simplify the display, a count is not shown if it is equal to the | |
886 | count of an earlier expression on the same line. | |
73804d4b RS |
887 | |
888 | The character @samp{=} following the count for an expression says that | |
a9f0a989 | 889 | the expression has returned the same value each time it was evaluated. |
1911e6e5 | 890 | In other words, it is not yet ``covered'' for coverage testing purposes. |
73804d4b RS |
891 | |
892 | To clear the frequency count and coverage data for a definition, | |
a9f0a989 | 893 | simply reinstrument it with @code{eval-defun}. |
73804d4b RS |
894 | @end deffn |
895 | ||
896 | For example, after evaluating @code{(fac 5)} with a source | |
897 | breakpoint, and setting @code{edebug-test-coverage} to @code{t}, when | |
898 | the breakpoint is reached, the frequency data looks like this: | |
899 | ||
900 | @example | |
901 | (defun fac (n) | |
902 | (if (= n 0) (edebug)) | |
903 | ;#6 1 0 =5 | |
904 | (if (< 0 n) | |
905 | ;#5 = | |
906 | (* n (fac (1- n))) | |
907 | ;# 5 0 | |
908 | 1)) | |
909 | ;# 0 | |
910 | @end example | |
911 | ||
87b2d5ff RS |
912 | The comment lines show that @code{fac} was called 6 times. The |
913 | first @code{if} statement returned 5 times with the same result each | |
73804d4b | 914 | time; the same is true of the condition on the second @code{if}. |
87b2d5ff | 915 | The recursive call of @code{fac} did not return at all. |
73804d4b RS |
916 | |
917 | ||
918 | @node The Outside Context | |
919 | @subsection The Outside Context | |
920 | ||
921 | Edebug tries to be transparent to the program you are debugging, but it | |
922 | does not succeed completely. Edebug also tries to be transparent when | |
923 | you evaluate expressions with @kbd{e} or with the evaluation list | |
924 | buffer, by temporarily restoring the outside context. This section | |
925 | explains precisely what context Edebug restores, and how Edebug fails to | |
926 | be completely transparent. | |
927 | ||
73804d4b RS |
928 | @menu |
929 | * Checking Whether to Stop:: When Edebug decides what to do. | |
930 | * Edebug Display Update:: When Edebug updates the display. | |
931 | * Edebug Recursive Edit:: When Edebug stops execution. | |
932 | @end menu | |
933 | ||
934 | @node Checking Whether to Stop | |
935 | @subsubsection Checking Whether to Stop | |
936 | ||
87b2d5ff RS |
937 | Whenever Edebug is entered, it needs to save and restore certain data |
938 | before even deciding whether to make trace information or stop the | |
939 | program. | |
73804d4b RS |
940 | |
941 | @itemize @bullet | |
942 | @item | |
943 | @code{max-lisp-eval-depth} and @code{max-specpdl-size} are both | |
a9f0a989 RS |
944 | incremented once to reduce Edebug's impact on the stack. You could, |
945 | however, still run out of stack space when using Edebug. | |
73804d4b RS |
946 | |
947 | @item | |
948 | The state of keyboard macro execution is saved and restored. While | |
949 | Edebug is active, @code{executing-macro} is bound to | |
950 | @code{edebug-continue-kbd-macro}. | |
951 | ||
952 | @end itemize | |
953 | ||
954 | ||
955 | @node Edebug Display Update | |
956 | @subsubsection Edebug Display Update | |
957 | ||
87b2d5ff RS |
958 | @c This paragraph is not filled, because LaLiberte's conversion script |
959 | @c needs an xref to be on just one line. | |
73804d4b | 960 | When Edebug needs to display something (e.g., in trace mode), it saves |
87b2d5ff RS |
961 | the current window configuration from ``outside'' Edebug |
962 | (@pxref{Window Configurations}). When you exit Edebug (by continuing | |
963 | the program), it restores the previous window configuration. | |
73804d4b RS |
964 | |
965 | Emacs redisplays only when it pauses. Usually, when you continue | |
8241495d RS |
966 | execution, the program re-enters Edebug at a breakpoint or after |
967 | stepping, without pausing or reading input in between. In such cases, | |
73804d4b | 968 | Emacs never gets a chance to redisplay the ``outside'' configuration. |
8241495d RS |
969 | Consequently, what you see is the same window configuration as the last |
970 | time Edebug was active, with no interruption. | |
73804d4b RS |
971 | |
972 | Entry to Edebug for displaying something also saves and restores the | |
8241495d RS |
973 | following data (though some of them are deliberately not restored if an |
974 | error or quit signal occurs). | |
73804d4b RS |
975 | |
976 | @itemize @bullet | |
977 | @item | |
978 | @cindex current buffer point and mark (Edebug) | |
979 | Which buffer is current, and the positions of point and the mark in the | |
980 | current buffer, are saved and restored. | |
981 | ||
982 | @item | |
983 | @cindex window configuration (Edebug) | |
984 | The outside window configuration is saved and restored if | |
985 | @code{edebug-save-windows} is non-@code{nil} (@pxref{Edebug Display Update}). | |
986 | ||
987 | The window configuration is not restored on error or quit, but the | |
988 | outside selected window @emph{is} reselected even on error or quit in | |
989 | case a @code{save-excursion} is active. If the value of | |
990 | @code{edebug-save-windows} is a list, only the listed windows are saved | |
991 | and restored. | |
992 | ||
993 | The window start and horizontal scrolling of the source code buffer are | |
994 | not restored, however, so that the display remains coherent within Edebug. | |
995 | ||
996 | @item | |
73804d4b RS |
997 | The value of point in each displayed buffer is saved and restored if |
998 | @code{edebug-save-displayed-buffer-points} is non-@code{nil}. | |
999 | ||
1000 | @item | |
1001 | The variables @code{overlay-arrow-position} and | |
1002 | @code{overlay-arrow-string} are saved and restored. So you can safely | |
1003 | invoke Edebug from the recursive edit elsewhere in the same buffer. | |
1004 | ||
1005 | @item | |
1006 | @code{cursor-in-echo-area} is locally bound to @code{nil} so that | |
1007 | the cursor shows up in the window. | |
1008 | @end itemize | |
1009 | ||
1010 | @node Edebug Recursive Edit | |
1011 | @subsubsection Edebug Recursive Edit | |
1012 | ||
1013 | When Edebug is entered and actually reads commands from the user, it | |
1014 | saves (and later restores) these additional data: | |
1015 | ||
1016 | @itemize @bullet | |
1017 | @item | |
1018 | The current match data. @xref{Match Data}. | |
1019 | ||
1020 | @item | |
1021 | @code{last-command}, @code{this-command}, @code{last-command-char}, | |
1022 | @code{last-input-char}, @code{last-input-event}, | |
1023 | @code{last-command-event}, @code{last-event-frame}, | |
1024 | @code{last-nonmenu-event}, and @code{track-mouse}. Commands used within | |
1025 | Edebug do not affect these variables outside of Edebug. | |
1026 | ||
1027 | The key sequence returned by @code{this-command-keys} is changed by | |
1028 | executing commands within Edebug and there is no way to reset | |
1029 | the key sequence from Lisp. | |
1030 | ||
87b2d5ff RS |
1031 | Edebug cannot save and restore the value of |
1032 | @code{unread-command-events}. Entering Edebug while this variable has a | |
1033 | nontrivial value can interfere with execution of the program you are | |
1034 | debugging. | |
1035 | ||
73804d4b RS |
1036 | @item |
1037 | Complex commands executed while in Edebug are added to the variable | |
1038 | @code{command-history}. In rare cases this can alter execution. | |
1039 | ||
1040 | @item | |
1041 | Within Edebug, the recursion depth appears one deeper than the recursion | |
1042 | depth outside Edebug. This is not true of the automatically updated | |
1043 | evaluation list window. | |
1044 | ||
1045 | @item | |
1046 | @code{standard-output} and @code{standard-input} are bound to @code{nil} | |
1047 | by the @code{recursive-edit}, but Edebug temporarily restores them during | |
1048 | evaluations. | |
1049 | ||
1050 | @item | |
1051 | The state of keyboard macro definition is saved and restored. While | |
1052 | Edebug is active, @code{defining-kbd-macro} is bound to | |
1053 | @code{edebug-continue-kbd-macro}. | |
1054 | @end itemize | |
1055 | ||
1056 | @node Instrumenting Macro Calls | |
1057 | @subsection Instrumenting Macro Calls | |
1058 | ||
969fe9b5 RS |
1059 | When Edebug instruments an expression that calls a Lisp macro, it needs |
1060 | additional information about the macro to do the job properly. This is | |
1061 | because there is no a-priori way to tell which subexpressions of the | |
1062 | macro call are forms to be evaluated. (Evaluation may occur explicitly | |
1063 | in the macro body, or when the resulting expansion is evaluated, or any | |
1064 | time later.) | |
1065 | ||
1066 | Therefore, you must define an Edebug specification for each macro that | |
1067 | Edebug will encounter, to explain the format of calls to that macro. To | |
1068 | do this, use @code{def-edebug-spec}. | |
73804d4b RS |
1069 | |
1070 | @deffn Macro def-edebug-spec macro specification | |
1071 | Specify which expressions of a call to macro @var{macro} are forms to be | |
1072 | evaluated. For simple macros, the @var{specification} often looks very | |
1073 | similar to the formal argument list of the macro definition, but | |
1074 | specifications are much more general than macro arguments. | |
1075 | ||
969fe9b5 | 1076 | The @var{macro} argument can actually be any symbol, not just a macro |
73804d4b RS |
1077 | name. |
1078 | @end deffn | |
1079 | ||
1080 | Here is a simple example that defines the specification for the | |
1911e6e5 | 1081 | @code{for} example macro (@pxref{Argument Evaluation}), followed by an |
a9f0a989 | 1082 | alternative, equivalent specification. |
73804d4b RS |
1083 | |
1084 | @example | |
1085 | (def-edebug-spec for | |
1086 | (symbolp "from" form "to" form "do" &rest form)) | |
1087 | ||
1088 | (def-edebug-spec for | |
1089 | (symbolp ['from form] ['to form] ['do body])) | |
1090 | @end example | |
1091 | ||
1092 | Here is a table of the possibilities for @var{specification} and how each | |
1093 | directs processing of arguments. | |
1094 | ||
ec221d13 | 1095 | @table @asis |
73804d4b RS |
1096 | @item @code{t} |
1097 | All arguments are instrumented for evaluation. | |
1098 | ||
1099 | @item @code{0} | |
1100 | None of the arguments is instrumented. | |
1101 | ||
1102 | @item a symbol | |
1103 | The symbol must have an Edebug specification which is used instead. | |
1104 | This indirection is repeated until another kind of specification is | |
a9f0a989 | 1105 | found. This allows you to inherit the specification from another macro. |
73804d4b RS |
1106 | |
1107 | @item a list | |
1108 | The elements of the list describe the types of the arguments of a | |
1109 | calling form. The possible elements of a specification list are | |
1110 | described in the following sections. | |
1111 | @end table | |
1112 | ||
1113 | @menu | |
1114 | * Specification List:: How to specify complex patterns of evaluation. | |
1115 | * Backtracking:: What Edebug does when matching fails. | |
73804d4b RS |
1116 | * Specification Examples:: To help understand specifications. |
1117 | @end menu | |
1118 | ||
1119 | ||
1120 | @node Specification List | |
1121 | @subsubsection Specification List | |
1122 | ||
1123 | @cindex Edebug specification list | |
1124 | A @dfn{specification list} is required for an Edebug specification if | |
1125 | some arguments of a macro call are evaluated while others are not. Some | |
1126 | elements in a specification list match one or more arguments, but others | |
1127 | modify the processing of all following elements. The latter, called | |
1128 | @dfn{specification keywords}, are symbols beginning with @samp{&} (such | |
1129 | as @code{&optional}). | |
1130 | ||
1131 | A specification list may contain sublists which match arguments that are | |
1132 | themselves lists, or it may contain vectors used for grouping. Sublists | |
1133 | and groups thus subdivide the specification list into a hierarchy of | |
969fe9b5 | 1134 | levels. Specification keywords apply only to the remainder of the |
73804d4b RS |
1135 | sublist or group they are contained in. |
1136 | ||
1137 | When a specification list involves alternatives or repetition, matching | |
1138 | it against an actual macro call may require backtracking. | |
1139 | @xref{Backtracking}, for more details. | |
1140 | ||
1141 | Edebug specifications provide the power of regular expression matching, | |
1142 | plus some context-free grammar constructs: the matching of sublists with | |
1143 | balanced parentheses, recursive processing of forms, and recursion via | |
1144 | indirect specifications. | |
1145 | ||
1146 | Here's a table of the possible elements of a specification list, with | |
1147 | their meanings: | |
1148 | ||
1149 | @table @code | |
1150 | @item sexp | |
1911e6e5 | 1151 | A single unevaluated Lisp object, which is not instrumented. |
a9f0a989 | 1152 | @c an "expression" is not necessarily intended for evaluation. |
73804d4b RS |
1153 | |
1154 | @item form | |
1155 | A single evaluated expression, which is instrumented. | |
1156 | ||
1157 | @item place | |
1158 | @findex edebug-unwrap | |
1159 | A place to store a value, as in the Common Lisp @code{setf} construct. | |
1160 | ||
1161 | @item body | |
1162 | Short for @code{&rest form}. See @code{&rest} below. | |
1163 | ||
1164 | @item function-form | |
1165 | A function form: either a quoted function symbol, a quoted lambda | |
1166 | expression, or a form (that should evaluate to a function symbol or | |
1167 | lambda expression). This is useful when an argument that's a lambda | |
1168 | expression might be quoted with @code{quote} rather than | |
1169 | @code{function}, since it instruments the body of the lambda expression | |
1170 | either way. | |
1171 | ||
1172 | @item lambda-expr | |
1173 | A lambda expression with no quoting. | |
1174 | ||
1175 | @item &optional | |
1176 | @kindex &optional @r{(Edebug)} | |
1177 | All following elements in the specification list are optional; as soon | |
1178 | as one does not match, Edebug stops matching at this level. | |
1179 | ||
1180 | To make just a few elements optional followed by non-optional elements, | |
1181 | use @code{[&optional @var{specs}@dots{}]}. To specify that several | |
1182 | elements must all match or none, use @code{&optional | |
1183 | [@var{specs}@dots{}]}. See the @code{defun} example below. | |
1184 | ||
1185 | @item &rest | |
1186 | @kindex &rest @r{(Edebug)} | |
1187 | All following elements in the specification list are repeated zero or | |
ebc6903b RS |
1188 | more times. In the last repetition, however, it is not a problem if the |
1189 | expression runs out before matching all of the elements of the | |
1190 | specification list. | |
73804d4b RS |
1191 | |
1192 | To repeat only a few elements, use @code{[&rest @var{specs}@dots{}]}. | |
1193 | To specify several elements that must all match on every repetition, use | |
1194 | @code{&rest [@var{specs}@dots{}]}. | |
1195 | ||
1196 | @item &or | |
1197 | @kindex &or @r{(Edebug)} | |
1198 | Each of the following elements in the specification list is an | |
1199 | alternative. One of the alternatives must match, or the @code{&or} | |
1200 | specification fails. | |
1201 | ||
1202 | Each list element following @code{&or} is a single alternative. To | |
1203 | group two or more list elements as a single alternative, enclose them in | |
1204 | @code{[@dots{}]}. | |
1205 | ||
1206 | @item ¬ | |
1207 | @kindex ¬ @r{(Edebug)} | |
1208 | Each of the following elements is matched as alternatives as if by using | |
1209 | @code{&or}, but if any of them match, the specification fails. If none | |
1210 | of them match, nothing is matched, but the @code{¬} specification | |
1211 | succeeds. | |
1212 | ||
1213 | @item &define | |
1214 | @kindex &define @r{(Edebug)} | |
1215 | Indicates that the specification is for a defining form. The defining | |
a9f0a989 | 1216 | form itself is not instrumented (that is, Edebug does not stop before and |
73804d4b RS |
1217 | after the defining form), but forms inside it typically will be |
1218 | instrumented. The @code{&define} keyword should be the first element in | |
1219 | a list specification. | |
1220 | ||
1221 | @item nil | |
1222 | This is successful when there are no more arguments to match at the | |
1223 | current argument list level; otherwise it fails. See sublist | |
1224 | specifications and the backquote example below. | |
1225 | ||
1226 | @item gate | |
1227 | @cindex preventing backtracking | |
1228 | No argument is matched but backtracking through the gate is disabled | |
1229 | while matching the remainder of the specifications at this level. This | |
1230 | is primarily used to generate more specific syntax error messages. See | |
1231 | @ref{Backtracking}, for more details. Also see the @code{let} example | |
1232 | below. | |
1233 | ||
1234 | @item @var{other-symbol} | |
1235 | @cindex indirect specifications | |
1236 | Any other symbol in a specification list may be a predicate or an | |
1237 | indirect specification. | |
1238 | ||
1239 | If the symbol has an Edebug specification, this @dfn{indirect | |
1240 | specification} should be either a list specification that is used in | |
1241 | place of the symbol, or a function that is called to process the | |
1242 | arguments. The specification may be defined with @code{def-edebug-spec} | |
1243 | just as for macros. See the @code{defun} example below. | |
1244 | ||
1245 | Otherwise, the symbol should be a predicate. The predicate is called | |
1246 | with the argument and the specification fails if the predicate returns | |
1247 | @code{nil}. In either case, that argument is not instrumented. | |
1248 | ||
73804d4b RS |
1249 | Some suitable predicates include @code{symbolp}, @code{integerp}, |
1250 | @code{stringp}, @code{vectorp}, and @code{atom}. | |
73804d4b RS |
1251 | |
1252 | @item [@var{elements}@dots{}] | |
1253 | @cindex [@dots{}] (Edebug) | |
1254 | A vector of elements groups the elements into a single @dfn{group | |
1255 | specification}. Its meaning has nothing to do with vectors. | |
1256 | ||
1257 | @item "@var{string}" | |
1258 | The argument should be a symbol named @var{string}. This specification | |
1259 | is equivalent to the quoted symbol, @code{'@var{symbol}}, where the name | |
1260 | of @var{symbol} is the @var{string}, but the string form is preferred. | |
1261 | ||
73804d4b RS |
1262 | @item (vector @var{elements}@dots{}) |
1263 | The argument should be a vector whose elements must match the | |
1264 | @var{elements} in the specification. See the backquote example below. | |
1265 | ||
1266 | @item (@var{elements}@dots{}) | |
1267 | Any other list is a @dfn{sublist specification} and the argument must be | |
1268 | a list whose elements match the specification @var{elements}. | |
1269 | ||
1270 | @cindex dotted lists (Edebug) | |
1271 | A sublist specification may be a dotted list and the corresponding list | |
1272 | argument may then be a dotted list. Alternatively, the last @sc{cdr} of a | |
1273 | dotted list specification may be another sublist specification (via a | |
a9f0a989 | 1274 | grouping or an indirect specification, e.g., @code{(spec . [(more |
73804d4b RS |
1275 | specs@dots{})])}) whose elements match the non-dotted list arguments. |
1276 | This is useful in recursive specifications such as in the backquote | |
1277 | example below. Also see the description of a @code{nil} specification | |
1278 | above for terminating such recursion. | |
1279 | ||
87b2d5ff RS |
1280 | Note that a sublist specification written as @code{(specs . nil)} |
1281 | is equivalent to @code{(specs)}, and @code{(specs . | |
1282 | (sublist-elements@dots{}))} is equivalent to @code{(specs | |
73804d4b RS |
1283 | sublist-elements@dots{})}. |
1284 | @end table | |
1285 | ||
1286 | @c Need to document extensions with &symbol and :symbol | |
1287 | ||
969fe9b5 | 1288 | Here is a list of additional specifications that may appear only after |
73804d4b RS |
1289 | @code{&define}. See the @code{defun} example below. |
1290 | ||
1291 | @table @code | |
1292 | @item name | |
1293 | The argument, a symbol, is the name of the defining form. | |
1294 | ||
1295 | A defining form is not required to have a name field; and it may have | |
1296 | multiple name fields. | |
1297 | ||
1298 | @item :name | |
1299 | This construct does not actually match an argument. The element | |
1300 | following @code{:name} should be a symbol; it is used as an additional | |
1301 | name component for the definition. You can use this to add a unique, | |
1302 | static component to the name of the definition. It may be used more | |
1303 | than once. | |
1304 | ||
1305 | @item arg | |
1306 | The argument, a symbol, is the name of an argument of the defining form. | |
a9f0a989 | 1307 | However, lambda-list keywords (symbols starting with @samp{&}) |
87b2d5ff | 1308 | are not allowed. |
73804d4b RS |
1309 | |
1310 | @item lambda-list | |
1311 | @cindex lambda-list (Edebug) | |
1312 | This matches a lambda list---the argument list of a lambda expression. | |
73804d4b RS |
1313 | |
1314 | @item def-body | |
1315 | The argument is the body of code in a definition. This is like | |
1316 | @code{body}, described above, but a definition body must be instrumented | |
1317 | with a different Edebug call that looks up information associated with | |
1318 | the definition. Use @code{def-body} for the highest level list of forms | |
1319 | within the definition. | |
1320 | ||
1321 | @item def-form | |
1322 | The argument is a single, highest-level form in a definition. This is | |
1323 | like @code{def-body}, except use this to match a single form rather than | |
1324 | a list of forms. As a special case, @code{def-form} also means that | |
1325 | tracing information is not output when the form is executed. See the | |
1326 | @code{interactive} example below. | |
1327 | @end table | |
1328 | ||
1329 | @node Backtracking | |
969fe9b5 | 1330 | @subsubsection Backtracking in Specifications |
73804d4b RS |
1331 | |
1332 | @cindex backtracking | |
1333 | @cindex syntax error (Edebug) | |
1334 | If a specification fails to match at some point, this does not | |
1335 | necessarily mean a syntax error will be signaled; instead, | |
1336 | @dfn{backtracking} will take place until all alternatives have been | |
1337 | exhausted. Eventually every element of the argument list must be | |
1338 | matched by some element in the specification, and every required element | |
1339 | in the specification must match some argument. | |
a9f0a989 RS |
1340 | |
1341 | When a syntax error is detected, it might not be reported until much | |
1342 | later after higher-level alternatives have been exhausted, and with the | |
1343 | point positioned further from the real error. But if backtracking is | |
1344 | disabled when an error occurs, it can be reported immediately. Note | |
1345 | that backtracking is also reenabled automatically in several situations; | |
1346 | it is reenabled when a new alternative is established by | |
1347 | @code{&optional}, @code{&rest}, or @code{&or}, or at the start of | |
1348 | processing a sublist, group, or indirect specification. The effect of | |
1349 | enabling or disabling backtracking is limited to the remainder of the | |
1350 | level currently being processed and lower levels. | |
1351 | ||
1352 | Backtracking is disabled while matching any of the | |
1353 | form specifications (that is, @code{form}, @code{body}, @code{def-form}, and | |
73804d4b RS |
1354 | @code{def-body}). These specifications will match any form so any error |
1355 | must be in the form itself rather than at a higher level. | |
1356 | ||
a9f0a989 | 1357 | Backtracking is also disabled after successfully matching a quoted |
73804d4b | 1358 | symbol or string specification, since this usually indicates a |
a9f0a989 | 1359 | recognized construct. But if you have a set of alternative constructs that |
73804d4b RS |
1360 | all begin with the same symbol, you can usually work around this |
1361 | constraint by factoring the symbol out of the alternatives, e.g., | |
1362 | @code{["foo" &or [first case] [second case] ...]}. | |
1363 | ||
a9f0a989 RS |
1364 | Most needs are satisfied by these two ways that bactracking is |
1365 | automatically disabled, but occasionally it is useful to explicitly | |
1366 | disable backtracking by using the @code{gate} specification. This is | |
1367 | useful when you know that no higher alternatives could apply. See the | |
1368 | example of the @code{let} specification. | |
73804d4b | 1369 | |
73804d4b RS |
1370 | @node Specification Examples |
1371 | @subsubsection Specification Examples | |
1372 | ||
1373 | It may be easier to understand Edebug specifications by studying | |
1374 | the examples provided here. | |
1375 | ||
1376 | A @code{let} special form has a sequence of bindings and a body. Each | |
1377 | of the bindings is either a symbol or a sublist with a symbol and | |
a9f0a989 | 1378 | optional expression. In the specification below, notice the @code{gate} |
73804d4b RS |
1379 | inside of the sublist to prevent backtracking once a sublist is found. |
1380 | ||
1381 | @example | |
1382 | (def-edebug-spec let | |
1383 | ((&rest | |
1384 | &or symbolp (gate symbolp &optional form)) | |
1385 | body)) | |
1386 | @end example | |
1387 | ||
1388 | Edebug uses the following specifications for @code{defun} and | |
1389 | @code{defmacro} and the associated argument list and @code{interactive} | |
1390 | specifications. It is necessary to handle interactive forms specially | |
1391 | since an expression argument it is actually evaluated outside of the | |
1392 | function body. | |
1393 | ||
87b2d5ff RS |
1394 | @smallexample |
1395 | (def-edebug-spec defmacro defun) ; @r{Indirect ref to @code{defun} spec.} | |
73804d4b RS |
1396 | (def-edebug-spec defun |
1397 | (&define name lambda-list | |
87b2d5ff | 1398 | [&optional stringp] ; @r{Match the doc string, if present.} |
73804d4b RS |
1399 | [&optional ("interactive" interactive)] |
1400 | def-body)) | |
1401 | ||
1402 | (def-edebug-spec lambda-list | |
1403 | (([&rest arg] | |
1404 | [&optional ["&optional" arg &rest arg]] | |
1405 | &optional ["&rest" arg] | |
1406 | ))) | |
1407 | ||
1408 | (def-edebug-spec interactive | |
1409 | (&optional &or stringp def-form)) ; @r{Notice: @code{def-form}} | |
87b2d5ff | 1410 | @end smallexample |
73804d4b RS |
1411 | |
1412 | The specification for backquote below illustrates how to match | |
1413 | dotted lists and use @code{nil} to terminate recursion. It also | |
1414 | illustrates how components of a vector may be matched. (The actual | |
1415 | specification defined by Edebug does not support dotted lists because | |
1416 | doing so causes very deep recursion that could fail.) | |
1417 | ||
87b2d5ff RS |
1418 | @smallexample |
1419 | (def-edebug-spec ` (backquote-form)) ; @r{Alias just for clarity.} | |
73804d4b RS |
1420 | |
1421 | (def-edebug-spec backquote-form | |
1422 | (&or ([&or "," ",@@"] &or ("quote" backquote-form) form) | |
1423 | (backquote-form . [&or nil backquote-form]) | |
1424 | (vector &rest backquote-form) | |
1425 | sexp)) | |
87b2d5ff | 1426 | @end smallexample |
73804d4b RS |
1427 | |
1428 | ||
1429 | @node Edebug Options | |
1430 | @subsection Edebug Options | |
1431 | ||
1432 | These options affect the behavior of Edebug: | |
1433 | ||
1434 | @defopt edebug-setup-hook | |
1435 | Functions to call before Edebug is used. Each time it is set to a new | |
1436 | value, Edebug will call those functions once and then | |
1437 | @code{edebug-setup-hook} is reset to @code{nil}. You could use this to | |
1438 | load up Edebug specifications associated with a package you are using | |
1439 | but only when you also use Edebug. | |
1440 | @xref{Instrumenting}. | |
1441 | @end defopt | |
1442 | ||
1443 | @defopt edebug-all-defs | |
1444 | If this is non-@code{nil}, normal evaluation of defining forms such as | |
1445 | @code{defun} and @code{defmacro} instruments them for Edebug. This | |
87b2d5ff RS |
1446 | applies to @code{eval-defun}, @code{eval-region}, @code{eval-buffer}, |
1447 | and @code{eval-current-buffer}. | |
1448 | ||
1449 | Use the command @kbd{M-x edebug-all-defs} to toggle the value of this | |
1450 | option. @xref{Instrumenting}. | |
73804d4b RS |
1451 | @end defopt |
1452 | ||
1453 | @defopt edebug-all-forms | |
87b2d5ff RS |
1454 | If this is non-@code{nil}, the commands @code{eval-defun}, |
1455 | @code{eval-region}, @code{eval-buffer}, and @code{eval-current-buffer} | |
1456 | instrument all forms, even those that don't define anything. | |
1457 | This doesn't apply to loading or evaluations in the minibuffer. | |
73804d4b RS |
1458 | |
1459 | Use the command @kbd{M-x edebug-all-forms} to toggle the value of this | |
87b2d5ff | 1460 | option. @xref{Instrumenting}. |
73804d4b RS |
1461 | @end defopt |
1462 | ||
1463 | @defopt edebug-save-windows | |
1464 | If this is non-@code{nil}, Edebug saves and restores the window | |
1465 | configuration. That takes some time, so if your program does not care | |
1466 | what happens to the window configurations, it is better to set this | |
1467 | variable to @code{nil}. | |
1468 | ||
1469 | If the value is a list, only the listed windows are saved and | |
1470 | restored. | |
1471 | ||
1472 | You can use the @kbd{W} command in Edebug to change this variable | |
1473 | interactively. @xref{Edebug Display Update}. | |
1474 | @end defopt | |
1475 | ||
1476 | @defopt edebug-save-displayed-buffer-points | |
87b2d5ff RS |
1477 | If this is non-@code{nil}, Edebug saves and restores point in all |
1478 | displayed buffers. | |
73804d4b RS |
1479 | |
1480 | Saving and restoring point in other buffers is necessary if you are | |
1481 | debugging code that changes the point of a buffer which is displayed in | |
1482 | a non-selected window. If Edebug or the user then selects the window, | |
87b2d5ff | 1483 | point in that buffer will move to the window's value of point. |
73804d4b RS |
1484 | |
1485 | Saving and restoring point in all buffers is expensive, since it | |
1486 | requires selecting each window twice, so enable this only if you need | |
1487 | it. @xref{Edebug Display Update}. | |
1488 | @end defopt | |
1489 | ||
1490 | @defopt edebug-initial-mode | |
1491 | If this variable is non-@code{nil}, it specifies the initial execution | |
1492 | mode for Edebug when it is first activated. Possible values are | |
1493 | @code{step}, @code{next}, @code{go}, @code{Go-nonstop}, @code{trace}, | |
1494 | @code{Trace-fast}, @code{continue}, and @code{Continue-fast}. | |
1495 | ||
1496 | The default value is @code{step}. | |
1497 | @xref{Edebug Execution Modes}. | |
1498 | @end defopt | |
1499 | ||
1500 | @defopt edebug-trace | |
73804d4b RS |
1501 | Non-@code{nil} means display a trace of function entry and exit. |
1502 | Tracing output is displayed in a buffer named @samp{*edebug-trace*}, one | |
1503 | function entry or exit per line, indented by the recursion level. | |
1504 | ||
1505 | The default value is @code{nil}. | |
1506 | ||
a9f0a989 | 1507 | Also see @code{edebug-tracing}, in @ref{Trace Buffer}. |
73804d4b RS |
1508 | @end defopt |
1509 | ||
1510 | @defopt edebug-test-coverage | |
1511 | If non-@code{nil}, Edebug tests coverage of all expressions debugged. | |
73804d4b RS |
1512 | @xref{Coverage Testing}. |
1513 | @end defopt | |
1514 | ||
1515 | @defopt edebug-continue-kbd-macro | |
1516 | If non-@code{nil}, continue defining or executing any keyboard macro | |
1517 | that is executing outside of Edebug. Use this with caution since it is not | |
1518 | debugged. | |
1519 | @xref{Edebug Execution Modes}. | |
1520 | @end defopt | |
1521 | ||
73804d4b RS |
1522 | @defopt edebug-on-error |
1523 | Edebug binds @code{debug-on-error} to this value, if | |
1524 | @code{debug-on-error} was previously @code{nil}. @xref{Trapping | |
1525 | Errors}. | |
1526 | @end defopt | |
1527 | ||
1528 | @defopt edebug-on-quit | |
1529 | Edebug binds @code{debug-on-quit} to this value, if | |
1530 | @code{debug-on-quit} was previously @code{nil}. @xref{Trapping | |
1531 | Errors}. | |
1532 | @end defopt | |
1533 | ||
1534 | If you change the values of @code{edebug-on-error} or | |
1535 | @code{edebug-on-quit} while Edebug is active, their values won't be used | |
87b2d5ff RS |
1536 | until the @emph{next} time Edebug is invoked via a new command. |
1537 | @c Not necessarily a deeper command level. | |
1538 | @c A new command is not precisely true, but that is close enough -- dan | |
73804d4b RS |
1539 | |
1540 | @defopt edebug-global-break-condition | |
1541 | If non-@code{nil}, an expression to test for at every stop point. | |
1542 | If the result is non-nil, then break. Errors are ignored. | |
1543 | @xref{Global Break Condition}. | |
1544 | @end defopt |