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73804d4b | 1 | @comment -*-texinfo-*- |
969fe9b5 | 2 | @c This is part of the GNU Emacs Lisp Reference Manual. |
c79ef4bb | 3 | @c Copyright (C) 1992, 1993, 1994, 1998, 1999, 2005 Free Software Foundation, Inc. |
969fe9b5 | 4 | @c See the file elisp.texi for copying conditions. |
73804d4b | 5 | |
177c0ea7 JB |
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 | ||
177c0ea7 | 38 | @item |
a9f0a989 | 39 | Automatically re-evaluate a list of expressions and |
73804d4b RS |
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. |
73804d4b | 101 | |
2634c6e4 | 102 | An arrow in the left fringe indicates the line where the function is |
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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 | |
8241495d RS |
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 | |
177c0ea7 | 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.). | |
b180eac2 | 127 | .(* n. .(fac .(1- n.).).). |
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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 | |
177c0ea7 | 145 | expression's value in the echo area. |
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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) | |
2634c6e4 RS |
161 | When you invoke command @kbd{C-M-x} (@code{eval-defun}) with a |
162 | prefix argument on a function definition, it instruments the | |
163 | definition before evaluating it. (This does not modify the source | |
164 | code itself.) If the variable @code{edebug-all-defs} is | |
165 | non-@code{nil}, that inverts the meaning of the prefix argument: in | |
166 | this case, @kbd{C-M-x} instruments the definition @emph{unless} it has | |
167 | a prefix argument. The default value of @code{edebug-all-defs} is | |
168 | @code{nil}. The command @kbd{M-x edebug-all-defs} toggles the value | |
169 | of the variable @code{edebug-all-defs}. | |
73804d4b | 170 | |
969fe9b5 RS |
171 | @findex eval-region @r{(Edebug)} |
172 | @findex eval-current-buffer @r{(Edebug)} | |
73804d4b RS |
173 | If @code{edebug-all-defs} is non-@code{nil}, then the commands |
174 | @code{eval-region}, @code{eval-current-buffer}, and @code{eval-buffer} | |
175 | also instrument any definitions they evaluate. Similarly, | |
176 | @code{edebug-all-forms} controls whether @code{eval-region} should | |
177 | instrument @emph{any} form, even non-defining forms. This doesn't apply | |
178 | to loading or evaluations in the minibuffer. The command @kbd{M-x | |
179 | edebug-all-forms} toggles this option. | |
180 | ||
181 | @findex edebug-eval-top-level-form | |
969fe9b5 | 182 | Another command, @kbd{M-x edebug-eval-top-level-form}, is available to |
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183 | instrument any top-level form regardless of the values of |
184 | @code{edebug-all-defs} and @code{edebug-all-forms}. | |
73804d4b | 185 | |
969fe9b5 | 186 | While Edebug is active, the command @kbd{I} |
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187 | (@code{edebug-instrument-callee}) instruments the definition of the |
188 | function or macro called by the list form after point, if is not already | |
189 | instrumented. This is possible only if Edebug knows where to find the | |
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190 | source for that function; for this reading, after loading Edebug, |
191 | @code{eval-region} records the position of every definition it | |
192 | evaluates, even if not instrumenting it. See also the @kbd{i} command | |
193 | (@pxref{Jumping}), which steps into the call after instrumenting the | |
194 | function. | |
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195 | |
196 | @cindex special forms (Edebug) | |
197 | @cindex interactive commands (Edebug) | |
198 | @cindex anonymous lambda expressions (Edebug) | |
199 | @cindex Common Lisp (Edebug) | |
969fe9b5 | 200 | @pindex cl.el @r{(Edebug)} |
73804d4b | 201 | @pindex cl-specs.el |
a9f0a989 RS |
202 | Edebug knows how to instrument all the standard special forms, |
203 | @code{interactive} forms with an expression argument, anonymous lambda | |
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204 | expressions, and other defining forms. However, Edebug cannot determine |
205 | on its own what a user-defined macro will do with the arguments of a | |
206 | macro call, so you must provide that information; see @ref{Instrumenting | |
207 | Macro Calls}, for details. | |
73804d4b | 208 | |
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209 | When Edebug is about to instrument code for the first time in a |
210 | session, it runs the hook @code{edebug-setup-hook}, then sets it to | |
8241495d | 211 | @code{nil}. You can use this to load Edebug specifications |
969fe9b5 | 212 | (@pxref{Instrumenting Macro Calls}) associated with a package you are |
8241495d | 213 | using, but only when you use Edebug. |
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214 | |
215 | @findex eval-expression @r{(Edebug)} | |
a9f0a989 | 216 | To remove instrumentation from a definition, simply re-evaluate its |
73804d4b | 217 | definition in a way that does not instrument. There are two ways of |
87b2d5ff | 218 | evaluating forms that never instrument them: from a file with |
73804d4b | 219 | @code{load}, and from the minibuffer with @code{eval-expression} |
bfe721d1 | 220 | (@kbd{M-:}). |
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221 | |
222 | If Edebug detects a syntax error while instrumenting, it leaves point | |
223 | at the erroneous code and signals an @code{invalid-read-syntax} error. | |
224 | ||
225 | @xref{Edebug Eval}, for other evaluation functions available | |
226 | inside of Edebug. | |
227 | ||
228 | @node Edebug Execution Modes | |
229 | @subsection Edebug Execution Modes | |
230 | ||
231 | @cindex Edebug execution modes | |
232 | Edebug supports several execution modes for running the program you are | |
233 | debugging. We call these alternatives @dfn{Edebug execution modes}; do | |
87b2d5ff | 234 | not confuse them with major or minor modes. The current Edebug execution mode |
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235 | determines how far Edebug continues execution before stopping---whether |
236 | it stops at each stop point, or continues to the next breakpoint, for | |
237 | example---and how much Edebug displays the progress of the evaluation | |
238 | before it stops. | |
239 | ||
240 | Normally, you specify the Edebug execution mode by typing a command to | |
241 | continue the program in a certain mode. Here is a table of these | |
8241495d | 242 | commands; all except for @kbd{S} resume execution of the program, at |
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243 | least for a certain distance. |
244 | ||
245 | @table @kbd | |
246 | @item S | |
8241495d | 247 | Stop: don't execute any more of the program, but wait for more |
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248 | Edebug commands (@code{edebug-stop}). |
249 | ||
250 | @item @key{SPC} | |
251 | Step: stop at the next stop point encountered (@code{edebug-step-mode}). | |
252 | ||
253 | @item n | |
254 | Next: stop at the next stop point encountered after an expression | |
255 | (@code{edebug-next-mode}). Also see @code{edebug-forward-sexp} in | |
256 | @ref{Edebug Misc}. | |
257 | ||
258 | @item t | |
89f6de49 RS |
259 | Trace: pause (normally one second) at each Edebug stop point |
260 | (@code{edebug-trace-mode}). | |
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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 | ||
2634c6e4 RS |
304 | When you enter a new Edebug level, the initial execution mode comes |
305 | from the value of the variable @code{edebug-initial-mode}. | |
306 | (@xref{Edebug Options}.) By default, this specifies step mode. Note | |
307 | that you may reenter the same Edebug level several times if, for | |
308 | example, an instrumented function is called several times from one | |
309 | command. | |
73804d4b | 310 | |
89f6de49 RS |
311 | @defopt edebug-sit-for-seconds |
312 | This option specifies how many seconds to wait between execution steps | |
313 | in trace mode. The default is 1 second. | |
b52a26fb | 314 | @end defopt |
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315 | |
316 | @node Jumping | |
317 | @subsection Jumping | |
318 | ||
319 | The commands described in this section execute until they reach a | |
320 | specified location. All except @kbd{i} make a temporary breakpoint to | |
321 | establish the place to stop, then switch to go mode. Any other | |
322 | breakpoint reached before the intended stop point will also stop | |
323 | execution. @xref{Breakpoints}, for the details on breakpoints. | |
324 | ||
325 | These commands may fail to work as expected in case of nonlocal exit, | |
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326 | as that can bypass the temporary breakpoint where you expected the |
327 | program to stop. | |
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328 | |
329 | @table @kbd | |
330 | @item h | |
331 | Proceed to the stop point near where point is (@code{edebug-goto-here}). | |
332 | ||
333 | @item f | |
334 | Run the program forward over one expression | |
335 | (@code{edebug-forward-sexp}). | |
336 | ||
337 | @item o | |
338 | Run the program until the end of the containing sexp. | |
339 | ||
340 | @item i | |
341 | Step into the function or macro called by the form after point. | |
342 | @end table | |
343 | ||
344 | The @kbd{h} command proceeds to the stop point near the current location | |
a9f0a989 RS |
345 | of point, using a temporary breakpoint. See @ref{Breakpoints}, for more |
346 | information about breakpoints. | |
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347 | |
348 | The @kbd{f} command runs the program forward over one expression. More | |
349 | precisely, it sets a temporary breakpoint at the position that | |
350 | @kbd{C-M-f} would reach, then executes in go mode so that the program | |
351 | will stop at breakpoints. | |
352 | ||
353 | With a prefix argument @var{n}, the temporary breakpoint is placed | |
354 | @var{n} sexps beyond point. If the containing list ends before @var{n} | |
355 | more elements, then the place to stop is after the containing | |
356 | expression. | |
357 | ||
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358 | You must check that the position @kbd{C-M-f} finds is a place that the |
359 | program will really get to. In @code{cond}, for example, this may not | |
360 | be true. | |
73804d4b | 361 | |
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362 | For flexibility, the @kbd{f} command does @code{forward-sexp} starting |
363 | at point, rather than at the stop point. If you want to execute one | |
364 | expression @emph{from the current stop point}, first type @kbd{w}, to | |
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365 | move point there, and then type @kbd{f}. |
366 | ||
367 | The @kbd{o} command continues ``out of'' an expression. It places a | |
368 | temporary breakpoint at the end of the sexp containing point. If the | |
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369 | containing sexp is a function definition itself, @kbd{o} continues until |
370 | just before the last sexp in the definition. If that is where you are | |
371 | now, it returns from the function and then stops. In other words, this | |
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372 | command does not exit the currently executing function unless you are |
373 | positioned after the last sexp. | |
374 | ||
375 | The @kbd{i} command steps into the function or macro called by the list | |
87b2d5ff RS |
376 | form after point, and stops at its first stop point. Note that the form |
377 | need not be the one about to be evaluated. But if the form is a | |
378 | function call about to be evaluated, remember to use this command before | |
379 | any of the arguments are evaluated, since otherwise it will be too late. | |
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380 | |
381 | The @kbd{i} command instruments the function or macro it's supposed to | |
382 | step into, if it isn't instrumented already. This is convenient, but keep | |
383 | in mind that the function or macro remains instrumented unless you explicitly | |
384 | arrange to deinstrument it. | |
385 | ||
386 | @node Edebug Misc | |
387 | @subsection Miscellaneous Edebug Commands | |
388 | ||
389 | Some miscellaneous Edebug commands are described here. | |
390 | ||
391 | @table @kbd | |
392 | @item ? | |
393 | Display the help message for Edebug (@code{edebug-help}). | |
394 | ||
395 | @item C-] | |
396 | Abort one level back to the previous command level | |
397 | (@code{abort-recursive-edit}). | |
398 | ||
399 | @item q | |
400 | Return to the top level editor command loop (@code{top-level}). This | |
401 | exits all recursive editing levels, including all levels of Edebug | |
402 | activity. However, instrumented code protected with | |
403 | @code{unwind-protect} or @code{condition-case} forms may resume | |
404 | debugging. | |
405 | ||
406 | @item Q | |
8241495d | 407 | Like @kbd{q}, but don't stop even for protected code |
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408 | (@code{top-level-nonstop}). |
409 | ||
410 | @item r | |
411 | Redisplay the most recently known expression result in the echo area | |
412 | (@code{edebug-previous-result}). | |
413 | ||
414 | @item d | |
415 | Display a backtrace, excluding Edebug's own functions for clarity | |
416 | (@code{edebug-backtrace}). | |
417 | ||
418 | You cannot use debugger commands in the backtrace buffer in Edebug as | |
419 | you would in the standard debugger. | |
420 | ||
421 | The backtrace buffer is killed automatically when you continue | |
422 | execution. | |
423 | @end table | |
424 | ||
8241495d RS |
425 | You can invoke commands from Edebug that activate Edebug again |
426 | recursively. Whenever Edebug is active, you can quit to the top level | |
427 | with @kbd{q} or abort one recursive edit level with @kbd{C-]}. You can | |
428 | display a backtrace of all the pending evaluations with @kbd{d}. | |
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429 | |
430 | @node Breakpoints | |
431 | @subsection Breakpoints | |
432 | ||
433 | @cindex breakpoints | |
8241495d | 434 | Edebug's step mode stops execution when the next stop point is reached. |
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435 | There are three other ways to stop Edebug execution once it has started: |
436 | breakpoints, the global break condition, and source breakpoints. | |
437 | ||
438 | While using Edebug, you can specify @dfn{breakpoints} in the program you | |
8241495d | 439 | are testing: these are places where execution should stop. You can set a |
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440 | breakpoint at any stop point, as defined in @ref{Using Edebug}. For |
441 | setting and unsetting breakpoints, the stop point that is affected is | |
442 | the first one at or after point in the source code buffer. Here are the | |
443 | Edebug commands for breakpoints: | |
444 | ||
445 | @table @kbd | |
446 | @item b | |
447 | Set a breakpoint at the stop point at or after point | |
448 | (@code{edebug-set-breakpoint}). If you use a prefix argument, the | |
8241495d RS |
449 | breakpoint is temporary---it turns off the first time it stops the |
450 | program. | |
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451 | |
452 | @item u | |
177c0ea7 | 453 | Unset the breakpoint (if any) at the stop point at or after |
73804d4b RS |
454 | point (@code{edebug-unset-breakpoint}). |
455 | ||
456 | @item x @var{condition} @key{RET} | |
457 | Set a conditional breakpoint which stops the program only if | |
458 | @var{condition} evaluates to a non-@code{nil} value | |
459 | (@code{edebug-set-conditional-breakpoint}). With a prefix argument, the | |
460 | breakpoint is temporary. | |
461 | ||
462 | @item B | |
9e2b495b | 463 | Move point to the next breakpoint in the current definition |
73804d4b RS |
464 | (@code{edebug-next-breakpoint}). |
465 | @end table | |
466 | ||
467 | While in Edebug, you can set a breakpoint with @kbd{b} and unset one | |
468 | with @kbd{u}. First move point to the Edebug stop point of your choice, | |
469 | then type @kbd{b} or @kbd{u} to set or unset a breakpoint there. | |
470 | Unsetting a breakpoint where none has been set has no effect. | |
471 | ||
8241495d RS |
472 | Re-evaluating or reinstrumenting a definition removes all of its |
473 | previous breakpoints. | |
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474 | |
475 | A @dfn{conditional breakpoint} tests a condition each time the program | |
476 | gets there. Any errors that occur as a result of evaluating the | |
477 | condition are ignored, as if the result were @code{nil}. To set a | |
478 | conditional breakpoint, use @kbd{x}, and specify the condition | |
479 | expression in the minibuffer. Setting a conditional breakpoint at a | |
480 | stop point that has a previously established conditional breakpoint puts | |
481 | the previous condition expression in the minibuffer so you can edit it. | |
482 | ||
483 | You can make a conditional or unconditional breakpoint | |
969fe9b5 | 484 | @dfn{temporary} by using a prefix argument with the command to set the |
73804d4b RS |
485 | breakpoint. When a temporary breakpoint stops the program, it is |
486 | automatically unset. | |
487 | ||
8241495d | 488 | Edebug always stops or pauses at a breakpoint, except when the Edebug |
73804d4b RS |
489 | mode is Go-nonstop. In that mode, it ignores breakpoints entirely. |
490 | ||
491 | To find out where your breakpoints are, use the @kbd{B} command, which | |
87b2d5ff RS |
492 | moves point to the next breakpoint following point, within the same |
493 | function, or to the first breakpoint if there are no following | |
494 | breakpoints. This command does not continue execution---it just moves | |
495 | point in the buffer. | |
73804d4b RS |
496 | |
497 | @menu | |
177c0ea7 | 498 | * Global Break Condition:: Breaking on an event. |
73804d4b RS |
499 | * Source Breakpoints:: Embedding breakpoints in source code. |
500 | @end menu | |
501 | ||
502 | ||
503 | @node Global Break Condition | |
504 | @subsubsection Global Break Condition | |
505 | ||
506 | @cindex stopping on events | |
507 | @cindex global break condition | |
508 | A @dfn{global break condition} stops execution when a specified | |
509 | condition is satisfied, no matter where that may occur. Edebug | |
8241495d | 510 | evaluates the global break condition at every stop point; if it |
73804d4b RS |
511 | evaluates to a non-@code{nil} value, then execution stops or pauses |
512 | depending on the execution mode, as if a breakpoint had been hit. If | |
513 | evaluating the condition gets an error, execution does not stop. | |
514 | ||
515 | @findex edebug-set-global-break-condition | |
9e2b495b RS |
516 | The condition expression is stored in |
517 | @code{edebug-global-break-condition}. You can specify a new expression | |
518 | using the @kbd{X} command (@code{edebug-set-global-break-condition}). | |
73804d4b RS |
519 | |
520 | The global break condition is the simplest way to find where in your | |
521 | code some event occurs, but it makes code run much more slowly. So you | |
522 | should reset the condition to @code{nil} when not using it. | |
523 | ||
524 | @node Source Breakpoints | |
525 | @subsubsection Source Breakpoints | |
526 | ||
527 | @findex edebug | |
528 | @cindex source breakpoints | |
529 | All breakpoints in a definition are forgotten each time you | |
8241495d RS |
530 | reinstrument it. If you wish to make a breakpoint that won't be |
531 | forgotten, you can write a @dfn{source breakpoint}, which is simply a | |
532 | call to the function @code{edebug} in your source code. You can, of | |
533 | course, make such a call conditional. For example, in the @code{fac} | |
534 | function, you can insert the first line as shown below, to stop when the | |
535 | argument reaches zero: | |
73804d4b RS |
536 | |
537 | @example | |
538 | (defun fac (n) | |
539 | (if (= n 0) (edebug)) | |
540 | (if (< 0 n) | |
541 | (* n (fac (1- n))) | |
542 | 1)) | |
543 | @end example | |
544 | ||
969fe9b5 | 545 | When the @code{fac} definition is instrumented and the function is |
73804d4b RS |
546 | called, the call to @code{edebug} acts as a breakpoint. Depending on |
547 | the execution mode, Edebug stops or pauses there. | |
548 | ||
969fe9b5 | 549 | If no instrumented code is being executed when @code{edebug} is called, |
73804d4b RS |
550 | that function calls @code{debug}. |
551 | @c This may not be a good idea anymore. | |
552 | ||
553 | @node Trapping Errors | |
554 | @subsection Trapping Errors | |
555 | ||
969fe9b5 RS |
556 | Emacs normally displays an error message when an error is signaled and |
557 | not handled with @code{condition-case}. While Edebug is active and | |
558 | executing instrumented code, it normally responds to all unhandled | |
559 | errors. You can customize this with the options @code{edebug-on-error} | |
560 | and @code{edebug-on-quit}; see @ref{Edebug Options}. | |
73804d4b | 561 | |
969fe9b5 | 562 | When Edebug responds to an error, it shows the last stop point |
73804d4b | 563 | encountered before the error. This may be the location of a call to a |
8241495d | 564 | function which was not instrumented, and within which the error actually |
73804d4b RS |
565 | occurred. For an unbound variable error, the last known stop point |
566 | might be quite distant from the offending variable reference. In that | |
8241495d | 567 | case, you might want to display a full backtrace (@pxref{Edebug Misc}). |
73804d4b | 568 | |
87b2d5ff | 569 | @c Edebug should be changed for the following: -- dan |
969fe9b5 | 570 | If you change @code{debug-on-error} or @code{debug-on-quit} while |
73804d4b RS |
571 | Edebug is active, these changes will be forgotten when Edebug becomes |
572 | inactive. Furthermore, during Edebug's recursive edit, these variables | |
573 | are bound to the values they had outside of Edebug. | |
574 | ||
73804d4b RS |
575 | @node Edebug Views |
576 | @subsection Edebug Views | |
577 | ||
969fe9b5 | 578 | These Edebug commands let you view aspects of the buffer and window |
a9f0a989 | 579 | status as they were before entry to Edebug. The outside window |
87b2d5ff RS |
580 | configuration is the collection of windows and contents that were in |
581 | effect outside of Edebug. | |
73804d4b RS |
582 | |
583 | @table @kbd | |
584 | @item v | |
87b2d5ff RS |
585 | Temporarily view the outside window configuration |
586 | (@code{edebug-view-outside}). | |
73804d4b RS |
587 | |
588 | @item p | |
589 | Temporarily display the outside current buffer with point at its outside | |
590 | position (@code{edebug-bounce-point}). With a prefix argument @var{n}, | |
591 | pause for @var{n} seconds instead. | |
592 | ||
593 | @item w | |
1911e6e5 RS |
594 | Move point back to the current stop point in the source code buffer |
595 | (@code{edebug-where}). | |
596 | ||
597 | If you use this command in a different window displaying the same | |
598 | buffer, that window will be used instead to display the current | |
599 | definition in the future. | |
73804d4b RS |
600 | |
601 | @item W | |
87b2d5ff RS |
602 | @c Its function is not simply to forget the saved configuration -- dan |
603 | Toggle whether Edebug saves and restores the outside window | |
604 | configuration (@code{edebug-toggle-save-windows}). | |
605 | ||
606 | With a prefix argument, @code{W} only toggles saving and restoring of | |
607 | the selected window. To specify a window that is not displaying the | |
608 | source code buffer, you must use @kbd{C-x X W} from the global keymap. | |
73804d4b RS |
609 | @end table |
610 | ||
969fe9b5 | 611 | You can view the outside window configuration with @kbd{v} or just |
73804d4b RS |
612 | bounce to the point in the current buffer with @kbd{p}, even if |
613 | it is not normally displayed. After moving point, you may wish to jump | |
614 | back to the stop point with @kbd{w} from a source code buffer. | |
615 | ||
969fe9b5 | 616 | Each time you use @kbd{W} to turn saving @emph{off}, Edebug forgets the |
87b2d5ff RS |
617 | saved outside window configuration---so that even if you turn saving |
618 | back @emph{on}, the current window configuration remains unchanged when | |
619 | you next exit Edebug (by continuing the program). However, the | |
620 | automatic redisplay of @samp{*edebug*} and @samp{*edebug-trace*} may | |
621 | conflict with the buffers you wish to see unless you have enough windows | |
622 | open. | |
73804d4b RS |
623 | |
624 | @node Edebug Eval | |
625 | @subsection Evaluation | |
626 | ||
8241495d RS |
627 | While within Edebug, you can evaluate expressions ``as if'' Edebug |
628 | were not running. Edebug tries to be invisible to the expression's | |
73804d4b | 629 | evaluation and printing. Evaluation of expressions that cause side |
8241495d RS |
630 | effects will work as expected, except for changes to data that Edebug |
631 | explicitly saves and restores. @xref{The Outside Context}, for details | |
632 | on this process. | |
73804d4b RS |
633 | |
634 | @table @kbd | |
635 | @item e @var{exp} @key{RET} | |
636 | Evaluate expression @var{exp} in the context outside of Edebug | |
637 | (@code{edebug-eval-expression}). That is, Edebug tries to minimize its | |
638 | interference with the evaluation. | |
639 | ||
bfe721d1 | 640 | @item M-: @var{exp} @key{RET} |
73804d4b RS |
641 | Evaluate expression @var{exp} in the context of Edebug itself. |
642 | ||
643 | @item C-x C-e | |
644 | Evaluate the expression before point, in the context outside of Edebug | |
645 | (@code{edebug-eval-last-sexp}). | |
646 | @end table | |
647 | ||
648 | @cindex lexical binding (Edebug) | |
969fe9b5 | 649 | Edebug supports evaluation of expressions containing references to |
73804d4b RS |
650 | lexically bound symbols created by the following constructs in |
651 | @file{cl.el} (version 2.03 or later): @code{lexical-let}, | |
652 | @code{macrolet}, and @code{symbol-macrolet}. | |
653 | ||
73804d4b RS |
654 | @node Eval List |
655 | @subsection Evaluation List Buffer | |
656 | ||
969fe9b5 | 657 | You can use the @dfn{evaluation list buffer}, called @samp{*edebug*}, to |
73804d4b RS |
658 | evaluate expressions interactively. You can also set up the |
659 | @dfn{evaluation list} of expressions to be evaluated automatically each | |
660 | time Edebug updates the display. | |
661 | ||
662 | @table @kbd | |
663 | @item E | |
664 | Switch to the evaluation list buffer @samp{*edebug*} | |
665 | (@code{edebug-visit-eval-list}). | |
666 | @end table | |
667 | ||
969fe9b5 | 668 | In the @samp{*edebug*} buffer you can use the commands of Lisp |
73804d4b RS |
669 | Interaction mode (@pxref{Lisp Interaction,,, emacs, The GNU Emacs |
670 | Manual}) as well as these special commands: | |
671 | ||
672 | @table @kbd | |
969fe9b5 | 673 | @item C-j |
73804d4b RS |
674 | Evaluate the expression before point, in the outside context, and insert |
675 | the value in the buffer (@code{edebug-eval-print-last-sexp}). | |
676 | ||
677 | @item C-x C-e | |
678 | Evaluate the expression before point, in the context outside of Edebug | |
679 | (@code{edebug-eval-last-sexp}). | |
680 | ||
681 | @item C-c C-u | |
87b2d5ff | 682 | Build a new evaluation list from the contents of the buffer |
73804d4b RS |
683 | (@code{edebug-update-eval-list}). |
684 | ||
685 | @item C-c C-d | |
686 | Delete the evaluation list group that point is in | |
687 | (@code{edebug-delete-eval-item}). | |
688 | ||
689 | @item C-c C-w | |
690 | Switch back to the source code buffer at the current stop point | |
691 | (@code{edebug-where}). | |
692 | @end table | |
693 | ||
969fe9b5 RS |
694 | You can evaluate expressions in the evaluation list window with |
695 | @kbd{C-j} or @kbd{C-x C-e}, just as you would in @samp{*scratch*}; | |
73804d4b RS |
696 | but they are evaluated in the context outside of Edebug. |
697 | ||
969fe9b5 | 698 | The expressions you enter interactively (and their results) are lost |
73804d4b | 699 | when you continue execution; but you can set up an @dfn{evaluation list} |
177c0ea7 | 700 | consisting of expressions to be evaluated each time execution stops. |
73804d4b RS |
701 | |
702 | @cindex evaluation list group | |
969fe9b5 | 703 | To do this, write one or more @dfn{evaluation list groups} in the |
73804d4b RS |
704 | evaluation list buffer. An evaluation list group consists of one or |
705 | more Lisp expressions. Groups are separated by comment lines. | |
706 | ||
969fe9b5 | 707 | The command @kbd{C-c C-u} (@code{edebug-update-eval-list}) rebuilds the |
73804d4b | 708 | evaluation list, scanning the buffer and using the first expression of |
87b2d5ff RS |
709 | each group. (The idea is that the second expression of the group is the |
710 | value previously computed and displayed.) | |
73804d4b | 711 | |
969fe9b5 | 712 | Each entry to Edebug redisplays the evaluation list by inserting each |
87b2d5ff RS |
713 | expression in the buffer, followed by its current value. It also |
714 | inserts comment lines so that each expression becomes its own group. | |
715 | Thus, if you type @kbd{C-c C-u} again without changing the buffer text, | |
716 | the evaluation list is effectively unchanged. | |
73804d4b | 717 | |
969fe9b5 | 718 | If an error occurs during an evaluation from the evaluation list, the |
73804d4b RS |
719 | error message is displayed in a string as if it were the result. |
720 | Therefore, expressions that use variables not currently valid do not | |
721 | interrupt your debugging. | |
722 | ||
969fe9b5 | 723 | Here is an example of what the evaluation list window looks like after |
73804d4b RS |
724 | several expressions have been added to it: |
725 | ||
726 | @smallexample | |
727 | (current-buffer) | |
728 | #<buffer *scratch*> | |
729 | ;--------------------------------------------------------------- | |
730 | (selected-window) | |
731 | #<window 16 on *scratch*> | |
732 | ;--------------------------------------------------------------- | |
733 | (point) | |
734 | 196 | |
735 | ;--------------------------------------------------------------- | |
736 | bad-var | |
737 | "Symbol's value as variable is void: bad-var" | |
738 | ;--------------------------------------------------------------- | |
739 | (recursion-depth) | |
740 | 0 | |
741 | ;--------------------------------------------------------------- | |
742 | this-command | |
743 | eval-last-sexp | |
744 | ;--------------------------------------------------------------- | |
745 | @end smallexample | |
746 | ||
747 | To delete a group, move point into it and type @kbd{C-c C-d}, or simply | |
748 | delete the text for the group and update the evaluation list with | |
749 | @kbd{C-c C-u}. To add a new expression to the evaluation list, insert | |
8241495d RS |
750 | the expression at a suitable place, insert a new comment line, then type |
751 | @kbd{C-c C-u}. You need not insert dashes in the comment line---its | |
752 | contents don't matter. | |
73804d4b RS |
753 | |
754 | After selecting @samp{*edebug*}, you can return to the source code | |
755 | buffer with @kbd{C-c C-w}. The @samp{*edebug*} buffer is killed when | |
756 | you continue execution, and recreated next time it is needed. | |
757 | ||
73804d4b RS |
758 | @node Printing in Edebug |
759 | @subsection Printing in Edebug | |
760 | ||
761 | @cindex printing (Edebug) | |
762 | @cindex printing circular structures | |
763 | @pindex cust-print | |
764 | If an expression in your program produces a value containing circular | |
765 | list structure, you may get an error when Edebug attempts to print it. | |
766 | ||
73804d4b RS |
767 | One way to cope with circular structure is to set @code{print-length} |
768 | or @code{print-level} to truncate the printing. Edebug does this for | |
769 | you; it binds @code{print-length} and @code{print-level} to 50 if they | |
770 | were @code{nil}. (Actually, the variables @code{edebug-print-length} | |
771 | and @code{edebug-print-level} specify the values to use within Edebug.) | |
772 | @xref{Output Variables}. | |
773 | ||
969fe9b5 | 774 | @defopt edebug-print-length |
8241495d RS |
775 | If non-@code{nil}, Edebug binds @code{print-length} to this value while |
776 | printing results. The default value is @code{50}. | |
969fe9b5 RS |
777 | @end defopt |
778 | ||
177c0ea7 | 779 | @defopt edebug-print-level |
8241495d RS |
780 | If non-@code{nil}, Edebug binds @code{print-level} to this value while |
781 | printing results. The default value is @code{50}. | |
969fe9b5 RS |
782 | @end defopt |
783 | ||
73804d4b | 784 | You can also print circular structures and structures that share |
8241495d RS |
785 | elements more informatively by binding @code{print-circle} |
786 | to a non-@code{nil} value. | |
73804d4b RS |
787 | |
788 | Here is an example of code that creates a circular structure: | |
789 | ||
790 | @example | |
791 | (setq a '(x y)) | |
a9f0a989 | 792 | (setcar a a) |
73804d4b RS |
793 | @end example |
794 | ||
795 | @noindent | |
796 | Custom printing prints this as @samp{Result: #1=(#1# y)}. The | |
797 | @samp{#1=} notation labels the structure that follows it with the label | |
a9f0a989 | 798 | @samp{1}, and the @samp{#1#} notation references the previously labeled |
73804d4b RS |
799 | structure. This notation is used for any shared elements of lists or |
800 | vectors. | |
801 | ||
177c0ea7 | 802 | @defopt edebug-print-circle |
8241495d | 803 | If non-@code{nil}, Edebug binds @code{print-circle} to this value while |
011caae1 | 804 | printing results. The default value is @code{t}. |
969fe9b5 RS |
805 | @end defopt |
806 | ||
73804d4b RS |
807 | Other programs can also use custom printing; see @file{cust-print.el} |
808 | for details. | |
809 | ||
810 | @node Trace Buffer | |
811 | @subsection Trace Buffer | |
812 | @cindex trace buffer | |
813 | ||
87b2d5ff | 814 | Edebug can record an execution trace, storing it in a buffer named |
73804d4b RS |
815 | @samp{*edebug-trace*}. This is a log of function calls and returns, |
816 | showing the function names and their arguments and values. To enable | |
817 | trace recording, set @code{edebug-trace} to a non-@code{nil} value. | |
818 | ||
819 | Making a trace buffer is not the same thing as using trace execution | |
820 | mode (@pxref{Edebug Execution Modes}). | |
821 | ||
822 | When trace recording is enabled, each function entry and exit adds | |
8241495d RS |
823 | lines to the trace buffer. A function entry record consists of |
824 | @samp{::::@{}, followed by the function name and argument values. A | |
825 | function exit record consists of @samp{::::@}}, followed by the function | |
73804d4b RS |
826 | name and result of the function. |
827 | ||
828 | The number of @samp{:}s in an entry shows its recursion depth. You | |
829 | can use the braces in the trace buffer to find the matching beginning or | |
830 | end of function calls. | |
831 | ||
832 | @findex edebug-print-trace-before | |
833 | @findex edebug-print-trace-after | |
834 | You can customize trace recording for function entry and exit by | |
835 | redefining the functions @code{edebug-print-trace-before} and | |
836 | @code{edebug-print-trace-after}. | |
837 | ||
838 | @defmac edebug-tracing string body@dots{} | |
839 | This macro requests additional trace information around the execution | |
840 | of the @var{body} forms. The argument @var{string} specifies text | |
8241495d | 841 | to put in the trace buffer. All the arguments are evaluated, and |
73804d4b RS |
842 | @code{edebug-tracing} returns the value of the last form in @var{body}. |
843 | @end defmac | |
844 | ||
845 | @defun edebug-trace format-string &rest format-args | |
846 | This function inserts text in the trace buffer. It computes the text | |
847 | with @code{(apply 'format @var{format-string} @var{format-args})}. | |
87b2d5ff | 848 | It also appends a newline to separate entries. |
73804d4b RS |
849 | @end defun |
850 | ||
1911e6e5 RS |
851 | @code{edebug-tracing} and @code{edebug-trace} insert lines in the |
852 | trace buffer whenever they are called, even if Edebug is not active. | |
853 | Adding text to the trace buffer also scrolls its window to show the last | |
854 | lines inserted. | |
73804d4b | 855 | |
73804d4b RS |
856 | @node Coverage Testing |
857 | @subsection Coverage Testing | |
858 | ||
859 | @cindex coverage testing | |
860 | @cindex frequency counts | |
861 | @cindex performance analysis | |
862 | Edebug provides rudimentary coverage testing and display of execution | |
1911e6e5 RS |
863 | frequency. |
864 | ||
865 | Coverage testing works by comparing the result of each expression with | |
866 | the previous result; each form in the program is considered ``covered'' | |
867 | if it has returned two different values since you began testing coverage | |
868 | in the current Emacs session. Thus, to do coverage testing on your | |
869 | program, execute it under various conditions and note whether it behaves | |
870 | correctly; Edebug will tell you when you have tried enough different | |
871 | conditions that each form has returned two different values. | |
872 | ||
873 | Coverage testing makes execution slower, so it is only done if | |
ebc6903b RS |
874 | @code{edebug-test-coverage} is non-@code{nil}. Frequency counting is |
875 | performed for all execution of an instrumented function, even if the | |
876 | execution mode is Go-nonstop, and regardless of whether coverage testing | |
877 | is enabled. | |
1911e6e5 | 878 | |
89f6de49 RS |
879 | @kindex C-x X = |
880 | @findex edebug-temp-display-freq-count | |
881 | Use @kbd{C-x X =} (@code{edebug-display-freq-count}) to display both | |
882 | the coverage information and the frequency counts for a definition. | |
883 | Just @kbd{=} (@code{edebug-temp-display-freq-count}) displays the same | |
884 | information temporarily, only until you type another key. | |
73804d4b RS |
885 | |
886 | @deffn Command edebug-display-freq-count | |
887 | This command displays the frequency count data for each line of the | |
888 | current definition. | |
889 | ||
969fe9b5 RS |
890 | The frequency counts appear as comment lines after each line of code, |
891 | and you can undo all insertions with one @code{undo} command. The | |
892 | counts appear under the @samp{(} before an expression or the @samp{)} | |
a9f0a989 RS |
893 | after an expression, or on the last character of a variable. To |
894 | simplify the display, a count is not shown if it is equal to the | |
895 | count of an earlier expression on the same line. | |
73804d4b RS |
896 | |
897 | The character @samp{=} following the count for an expression says that | |
a9f0a989 | 898 | the expression has returned the same value each time it was evaluated. |
1911e6e5 | 899 | In other words, it is not yet ``covered'' for coverage testing purposes. |
73804d4b RS |
900 | |
901 | To clear the frequency count and coverage data for a definition, | |
a9f0a989 | 902 | simply reinstrument it with @code{eval-defun}. |
73804d4b RS |
903 | @end deffn |
904 | ||
905 | For example, after evaluating @code{(fac 5)} with a source | |
906 | breakpoint, and setting @code{edebug-test-coverage} to @code{t}, when | |
907 | the breakpoint is reached, the frequency data looks like this: | |
908 | ||
909 | @example | |
910 | (defun fac (n) | |
911 | (if (= n 0) (edebug)) | |
011caae1 | 912 | ;#6 1 = =5 |
73804d4b | 913 | (if (< 0 n) |
177c0ea7 | 914 | ;#5 = |
73804d4b | 915 | (* n (fac (1- n))) |
177c0ea7 | 916 | ;# 5 0 |
73804d4b | 917 | 1)) |
177c0ea7 | 918 | ;# 0 |
73804d4b RS |
919 | @end example |
920 | ||
87b2d5ff RS |
921 | The comment lines show that @code{fac} was called 6 times. The |
922 | first @code{if} statement returned 5 times with the same result each | |
73804d4b | 923 | time; the same is true of the condition on the second @code{if}. |
87b2d5ff | 924 | The recursive call of @code{fac} did not return at all. |
73804d4b RS |
925 | |
926 | ||
927 | @node The Outside Context | |
928 | @subsection The Outside Context | |
929 | ||
930 | Edebug tries to be transparent to the program you are debugging, but it | |
931 | does not succeed completely. Edebug also tries to be transparent when | |
932 | you evaluate expressions with @kbd{e} or with the evaluation list | |
933 | buffer, by temporarily restoring the outside context. This section | |
934 | explains precisely what context Edebug restores, and how Edebug fails to | |
935 | be completely transparent. | |
936 | ||
73804d4b RS |
937 | @menu |
938 | * Checking Whether to Stop:: When Edebug decides what to do. | |
939 | * Edebug Display Update:: When Edebug updates the display. | |
940 | * Edebug Recursive Edit:: When Edebug stops execution. | |
941 | @end menu | |
942 | ||
943 | @node Checking Whether to Stop | |
944 | @subsubsection Checking Whether to Stop | |
945 | ||
87b2d5ff RS |
946 | Whenever Edebug is entered, it needs to save and restore certain data |
947 | before even deciding whether to make trace information or stop the | |
948 | program. | |
73804d4b RS |
949 | |
950 | @itemize @bullet | |
177c0ea7 | 951 | @item |
73804d4b | 952 | @code{max-lisp-eval-depth} and @code{max-specpdl-size} are both |
a9f0a989 RS |
953 | incremented once to reduce Edebug's impact on the stack. You could, |
954 | however, still run out of stack space when using Edebug. | |
73804d4b | 955 | |
177c0ea7 | 956 | @item |
73804d4b RS |
957 | The state of keyboard macro execution is saved and restored. While |
958 | Edebug is active, @code{executing-macro} is bound to | |
959 | @code{edebug-continue-kbd-macro}. | |
960 | ||
961 | @end itemize | |
962 | ||
963 | ||
964 | @node Edebug Display Update | |
965 | @subsubsection Edebug Display Update | |
966 | ||
87b2d5ff RS |
967 | @c This paragraph is not filled, because LaLiberte's conversion script |
968 | @c needs an xref to be on just one line. | |
73804d4b | 969 | When Edebug needs to display something (e.g., in trace mode), it saves |
177c0ea7 | 970 | the current window configuration from ``outside'' Edebug |
87b2d5ff RS |
971 | (@pxref{Window Configurations}). When you exit Edebug (by continuing |
972 | the program), it restores the previous window configuration. | |
73804d4b RS |
973 | |
974 | Emacs redisplays only when it pauses. Usually, when you continue | |
8241495d RS |
975 | execution, the program re-enters Edebug at a breakpoint or after |
976 | stepping, without pausing or reading input in between. In such cases, | |
73804d4b | 977 | Emacs never gets a chance to redisplay the ``outside'' configuration. |
8241495d RS |
978 | Consequently, what you see is the same window configuration as the last |
979 | time Edebug was active, with no interruption. | |
73804d4b RS |
980 | |
981 | Entry to Edebug for displaying something also saves and restores the | |
8241495d RS |
982 | following data (though some of them are deliberately not restored if an |
983 | error or quit signal occurs). | |
73804d4b RS |
984 | |
985 | @itemize @bullet | |
177c0ea7 | 986 | @item |
73804d4b RS |
987 | @cindex current buffer point and mark (Edebug) |
988 | Which buffer is current, and the positions of point and the mark in the | |
989 | current buffer, are saved and restored. | |
990 | ||
177c0ea7 | 991 | @item |
73804d4b RS |
992 | @cindex window configuration (Edebug) |
993 | The outside window configuration is saved and restored if | |
994 | @code{edebug-save-windows} is non-@code{nil} (@pxref{Edebug Display Update}). | |
995 | ||
996 | The window configuration is not restored on error or quit, but the | |
997 | outside selected window @emph{is} reselected even on error or quit in | |
998 | case a @code{save-excursion} is active. If the value of | |
999 | @code{edebug-save-windows} is a list, only the listed windows are saved | |
1000 | and restored. | |
1001 | ||
1002 | The window start and horizontal scrolling of the source code buffer are | |
1003 | not restored, however, so that the display remains coherent within Edebug. | |
1004 | ||
1005 | @item | |
73804d4b RS |
1006 | The value of point in each displayed buffer is saved and restored if |
1007 | @code{edebug-save-displayed-buffer-points} is non-@code{nil}. | |
1008 | ||
1009 | @item | |
1010 | The variables @code{overlay-arrow-position} and | |
1011 | @code{overlay-arrow-string} are saved and restored. So you can safely | |
1012 | invoke Edebug from the recursive edit elsewhere in the same buffer. | |
1013 | ||
177c0ea7 | 1014 | @item |
73804d4b RS |
1015 | @code{cursor-in-echo-area} is locally bound to @code{nil} so that |
1016 | the cursor shows up in the window. | |
1017 | @end itemize | |
1018 | ||
1019 | @node Edebug Recursive Edit | |
1020 | @subsubsection Edebug Recursive Edit | |
1021 | ||
1022 | When Edebug is entered and actually reads commands from the user, it | |
1023 | saves (and later restores) these additional data: | |
1024 | ||
1025 | @itemize @bullet | |
1026 | @item | |
1027 | The current match data. @xref{Match Data}. | |
1028 | ||
1029 | @item | |
1030 | @code{last-command}, @code{this-command}, @code{last-command-char}, | |
1031 | @code{last-input-char}, @code{last-input-event}, | |
1032 | @code{last-command-event}, @code{last-event-frame}, | |
1033 | @code{last-nonmenu-event}, and @code{track-mouse}. Commands used within | |
1034 | Edebug do not affect these variables outside of Edebug. | |
1035 | ||
1036 | The key sequence returned by @code{this-command-keys} is changed by | |
1037 | executing commands within Edebug and there is no way to reset | |
1038 | the key sequence from Lisp. | |
1039 | ||
87b2d5ff RS |
1040 | Edebug cannot save and restore the value of |
1041 | @code{unread-command-events}. Entering Edebug while this variable has a | |
1042 | nontrivial value can interfere with execution of the program you are | |
1043 | debugging. | |
1044 | ||
73804d4b RS |
1045 | @item |
1046 | Complex commands executed while in Edebug are added to the variable | |
1047 | @code{command-history}. In rare cases this can alter execution. | |
1048 | ||
1049 | @item | |
1050 | Within Edebug, the recursion depth appears one deeper than the recursion | |
1051 | depth outside Edebug. This is not true of the automatically updated | |
1052 | evaluation list window. | |
1053 | ||
1054 | @item | |
1055 | @code{standard-output} and @code{standard-input} are bound to @code{nil} | |
1056 | by the @code{recursive-edit}, but Edebug temporarily restores them during | |
1057 | evaluations. | |
1058 | ||
177c0ea7 | 1059 | @item |
73804d4b RS |
1060 | The state of keyboard macro definition is saved and restored. While |
1061 | Edebug is active, @code{defining-kbd-macro} is bound to | |
1062 | @code{edebug-continue-kbd-macro}. | |
1063 | @end itemize | |
1064 | ||
1065 | @node Instrumenting Macro Calls | |
1066 | @subsection Instrumenting Macro Calls | |
1067 | ||
969fe9b5 RS |
1068 | When Edebug instruments an expression that calls a Lisp macro, it needs |
1069 | additional information about the macro to do the job properly. This is | |
1070 | because there is no a-priori way to tell which subexpressions of the | |
1071 | macro call are forms to be evaluated. (Evaluation may occur explicitly | |
1072 | in the macro body, or when the resulting expansion is evaluated, or any | |
1073 | time later.) | |
1074 | ||
f9350c5c RS |
1075 | Therefore, you must define an Edebug specification for each macro |
1076 | that Edebug will encounter, to explain the format of calls to that | |
a7679889 | 1077 | macro. To do this, add a @code{debug} declaration to the macro |
f9350c5c RS |
1078 | definition. Here is a simple example that shows the specification for |
1079 | the @code{for} example macro (@pxref{Argument Evaluation}). | |
1080 | ||
1081 | @example | |
1082 | (defmacro for (var from init to final do &rest body) | |
1083 | "Execute a simple \"for\" loop. | |
1084 | For example, (for i from 1 to 10 do (print i))." | |
af5a6df7 | 1085 | (declare (debug (symbolp "from" form "to" form "do" &rest form))) |
f9350c5c RS |
1086 | ...) |
1087 | @end example | |
1088 | ||
89f6de49 | 1089 | The Edebug specification says which parts of a call to the macro are |
a756468d RS |
1090 | forms to be evaluated. For simple macros, the @var{specification} |
1091 | often looks very similar to the formal argument list of the macro | |
1092 | definition, but specifications are much more general than macro | |
1093 | arguments. @xref{Defining Macros}, for more explanation of | |
40d2bb40 | 1094 | the @code{declare} form. |
a756468d RS |
1095 | |
1096 | You can also define an edebug specification for a macro separately | |
f9350c5c | 1097 | from the macro definition with @code{def-edebug-spec}. Adding |
a7679889 LK |
1098 | @code{debug} declarations is preferred, and more convenient, for macro |
1099 | definitions in Lisp, but @code{def-edebug-spec} makes it possible to | |
1100 | define Edebug specifications for special forms implemented in C. | |
73804d4b RS |
1101 | |
1102 | @deffn Macro def-edebug-spec macro specification | |
1103 | Specify which expressions of a call to macro @var{macro} are forms to be | |
f9350c5c RS |
1104 | evaluated. @var{specification} should be the edebug specification. |
1105 | It is not evaluated. | |
73804d4b | 1106 | |
969fe9b5 | 1107 | The @var{macro} argument can actually be any symbol, not just a macro |
73804d4b RS |
1108 | name. |
1109 | @end deffn | |
1110 | ||
73804d4b RS |
1111 | Here is a table of the possibilities for @var{specification} and how each |
1112 | directs processing of arguments. | |
1113 | ||
ec221d13 | 1114 | @table @asis |
73804d4b RS |
1115 | @item @code{t} |
1116 | All arguments are instrumented for evaluation. | |
1117 | ||
1118 | @item @code{0} | |
1119 | None of the arguments is instrumented. | |
1120 | ||
1121 | @item a symbol | |
1122 | The symbol must have an Edebug specification which is used instead. | |
1123 | This indirection is repeated until another kind of specification is | |
a9f0a989 | 1124 | found. This allows you to inherit the specification from another macro. |
73804d4b RS |
1125 | |
1126 | @item a list | |
1127 | The elements of the list describe the types of the arguments of a | |
1128 | calling form. The possible elements of a specification list are | |
1129 | described in the following sections. | |
1130 | @end table | |
1131 | ||
1132 | @menu | |
1133 | * Specification List:: How to specify complex patterns of evaluation. | |
1134 | * Backtracking:: What Edebug does when matching fails. | |
73804d4b RS |
1135 | * Specification Examples:: To help understand specifications. |
1136 | @end menu | |
1137 | ||
1138 | ||
1139 | @node Specification List | |
1140 | @subsubsection Specification List | |
1141 | ||
1142 | @cindex Edebug specification list | |
1143 | A @dfn{specification list} is required for an Edebug specification if | |
1144 | some arguments of a macro call are evaluated while others are not. Some | |
1145 | elements in a specification list match one or more arguments, but others | |
1146 | modify the processing of all following elements. The latter, called | |
1147 | @dfn{specification keywords}, are symbols beginning with @samp{&} (such | |
1148 | as @code{&optional}). | |
1149 | ||
1150 | A specification list may contain sublists which match arguments that are | |
1151 | themselves lists, or it may contain vectors used for grouping. Sublists | |
1152 | and groups thus subdivide the specification list into a hierarchy of | |
969fe9b5 | 1153 | levels. Specification keywords apply only to the remainder of the |
73804d4b RS |
1154 | sublist or group they are contained in. |
1155 | ||
1156 | When a specification list involves alternatives or repetition, matching | |
1157 | it against an actual macro call may require backtracking. | |
1158 | @xref{Backtracking}, for more details. | |
1159 | ||
1160 | Edebug specifications provide the power of regular expression matching, | |
1161 | plus some context-free grammar constructs: the matching of sublists with | |
1162 | balanced parentheses, recursive processing of forms, and recursion via | |
1163 | indirect specifications. | |
1164 | ||
1165 | Here's a table of the possible elements of a specification list, with | |
1166 | their meanings: | |
1167 | ||
1168 | @table @code | |
1169 | @item sexp | |
1911e6e5 | 1170 | A single unevaluated Lisp object, which is not instrumented. |
a9f0a989 | 1171 | @c an "expression" is not necessarily intended for evaluation. |
73804d4b RS |
1172 | |
1173 | @item form | |
1174 | A single evaluated expression, which is instrumented. | |
1175 | ||
1176 | @item place | |
1177 | @findex edebug-unwrap | |
1178 | A place to store a value, as in the Common Lisp @code{setf} construct. | |
1179 | ||
1180 | @item body | |
1181 | Short for @code{&rest form}. See @code{&rest} below. | |
1182 | ||
1183 | @item function-form | |
1184 | A function form: either a quoted function symbol, a quoted lambda | |
1185 | expression, or a form (that should evaluate to a function symbol or | |
1186 | lambda expression). This is useful when an argument that's a lambda | |
1187 | expression might be quoted with @code{quote} rather than | |
1188 | @code{function}, since it instruments the body of the lambda expression | |
1189 | either way. | |
1190 | ||
1191 | @item lambda-expr | |
1192 | A lambda expression with no quoting. | |
1193 | ||
1194 | @item &optional | |
89f6de49 | 1195 | @c @kindex &optional @r{(Edebug)} |
73804d4b | 1196 | All following elements in the specification list are optional; as soon |
177c0ea7 | 1197 | as one does not match, Edebug stops matching at this level. |
73804d4b RS |
1198 | |
1199 | To make just a few elements optional followed by non-optional elements, | |
1200 | use @code{[&optional @var{specs}@dots{}]}. To specify that several | |
1201 | elements must all match or none, use @code{&optional | |
1202 | [@var{specs}@dots{}]}. See the @code{defun} example below. | |
1203 | ||
1204 | @item &rest | |
89f6de49 | 1205 | @c @kindex &rest @r{(Edebug)} |
73804d4b | 1206 | All following elements in the specification list are repeated zero or |
ebc6903b RS |
1207 | more times. In the last repetition, however, it is not a problem if the |
1208 | expression runs out before matching all of the elements of the | |
1209 | specification list. | |
73804d4b RS |
1210 | |
1211 | To repeat only a few elements, use @code{[&rest @var{specs}@dots{}]}. | |
1212 | To specify several elements that must all match on every repetition, use | |
1213 | @code{&rest [@var{specs}@dots{}]}. | |
1214 | ||
1215 | @item &or | |
89f6de49 | 1216 | @c @kindex &or @r{(Edebug)} |
73804d4b RS |
1217 | Each of the following elements in the specification list is an |
1218 | alternative. One of the alternatives must match, or the @code{&or} | |
1219 | specification fails. | |
1220 | ||
1221 | Each list element following @code{&or} is a single alternative. To | |
1222 | group two or more list elements as a single alternative, enclose them in | |
1223 | @code{[@dots{}]}. | |
1224 | ||
1225 | @item ¬ | |
89f6de49 | 1226 | @c @kindex ¬ @r{(Edebug)} |
73804d4b RS |
1227 | Each of the following elements is matched as alternatives as if by using |
1228 | @code{&or}, but if any of them match, the specification fails. If none | |
1229 | of them match, nothing is matched, but the @code{¬} specification | |
1230 | succeeds. | |
1231 | ||
177c0ea7 | 1232 | @item &define |
89f6de49 | 1233 | @c @kindex &define @r{(Edebug)} |
73804d4b | 1234 | Indicates that the specification is for a defining form. The defining |
a9f0a989 | 1235 | form itself is not instrumented (that is, Edebug does not stop before and |
73804d4b RS |
1236 | after the defining form), but forms inside it typically will be |
1237 | instrumented. The @code{&define} keyword should be the first element in | |
1238 | a list specification. | |
1239 | ||
1240 | @item nil | |
1241 | This is successful when there are no more arguments to match at the | |
1242 | current argument list level; otherwise it fails. See sublist | |
1243 | specifications and the backquote example below. | |
1244 | ||
1245 | @item gate | |
1246 | @cindex preventing backtracking | |
1247 | No argument is matched but backtracking through the gate is disabled | |
1248 | while matching the remainder of the specifications at this level. This | |
1249 | is primarily used to generate more specific syntax error messages. See | |
1250 | @ref{Backtracking}, for more details. Also see the @code{let} example | |
1251 | below. | |
1252 | ||
1253 | @item @var{other-symbol} | |
1254 | @cindex indirect specifications | |
1255 | Any other symbol in a specification list may be a predicate or an | |
1256 | indirect specification. | |
1257 | ||
1258 | If the symbol has an Edebug specification, this @dfn{indirect | |
1259 | specification} should be either a list specification that is used in | |
1260 | place of the symbol, or a function that is called to process the | |
1261 | arguments. The specification may be defined with @code{def-edebug-spec} | |
1262 | just as for macros. See the @code{defun} example below. | |
1263 | ||
1264 | Otherwise, the symbol should be a predicate. The predicate is called | |
1265 | with the argument and the specification fails if the predicate returns | |
1266 | @code{nil}. In either case, that argument is not instrumented. | |
1267 | ||
73804d4b RS |
1268 | Some suitable predicates include @code{symbolp}, @code{integerp}, |
1269 | @code{stringp}, @code{vectorp}, and @code{atom}. | |
73804d4b RS |
1270 | |
1271 | @item [@var{elements}@dots{}] | |
1272 | @cindex [@dots{}] (Edebug) | |
1273 | A vector of elements groups the elements into a single @dfn{group | |
1274 | specification}. Its meaning has nothing to do with vectors. | |
1275 | ||
1276 | @item "@var{string}" | |
1277 | The argument should be a symbol named @var{string}. This specification | |
1278 | is equivalent to the quoted symbol, @code{'@var{symbol}}, where the name | |
1279 | of @var{symbol} is the @var{string}, but the string form is preferred. | |
1280 | ||
73804d4b RS |
1281 | @item (vector @var{elements}@dots{}) |
1282 | The argument should be a vector whose elements must match the | |
1283 | @var{elements} in the specification. See the backquote example below. | |
1284 | ||
1285 | @item (@var{elements}@dots{}) | |
1286 | Any other list is a @dfn{sublist specification} and the argument must be | |
1287 | a list whose elements match the specification @var{elements}. | |
1288 | ||
1289 | @cindex dotted lists (Edebug) | |
1290 | A sublist specification may be a dotted list and the corresponding list | |
1291 | argument may then be a dotted list. Alternatively, the last @sc{cdr} of a | |
1292 | dotted list specification may be another sublist specification (via a | |
a9f0a989 | 1293 | grouping or an indirect specification, e.g., @code{(spec . [(more |
73804d4b RS |
1294 | specs@dots{})])}) whose elements match the non-dotted list arguments. |
1295 | This is useful in recursive specifications such as in the backquote | |
1296 | example below. Also see the description of a @code{nil} specification | |
1297 | above for terminating such recursion. | |
1298 | ||
87b2d5ff RS |
1299 | Note that a sublist specification written as @code{(specs . nil)} |
1300 | is equivalent to @code{(specs)}, and @code{(specs . | |
1301 | (sublist-elements@dots{}))} is equivalent to @code{(specs | |
73804d4b RS |
1302 | sublist-elements@dots{})}. |
1303 | @end table | |
1304 | ||
1305 | @c Need to document extensions with &symbol and :symbol | |
1306 | ||
969fe9b5 | 1307 | Here is a list of additional specifications that may appear only after |
73804d4b RS |
1308 | @code{&define}. See the @code{defun} example below. |
1309 | ||
1310 | @table @code | |
1311 | @item name | |
177c0ea7 | 1312 | The argument, a symbol, is the name of the defining form. |
73804d4b RS |
1313 | |
1314 | A defining form is not required to have a name field; and it may have | |
1315 | multiple name fields. | |
1316 | ||
1317 | @item :name | |
1318 | This construct does not actually match an argument. The element | |
1319 | following @code{:name} should be a symbol; it is used as an additional | |
1320 | name component for the definition. You can use this to add a unique, | |
1321 | static component to the name of the definition. It may be used more | |
1322 | than once. | |
1323 | ||
1324 | @item arg | |
1325 | The argument, a symbol, is the name of an argument of the defining form. | |
a9f0a989 | 1326 | However, lambda-list keywords (symbols starting with @samp{&}) |
87b2d5ff | 1327 | are not allowed. |
73804d4b RS |
1328 | |
1329 | @item lambda-list | |
1330 | @cindex lambda-list (Edebug) | |
1331 | This matches a lambda list---the argument list of a lambda expression. | |
73804d4b RS |
1332 | |
1333 | @item def-body | |
1334 | The argument is the body of code in a definition. This is like | |
1335 | @code{body}, described above, but a definition body must be instrumented | |
1336 | with a different Edebug call that looks up information associated with | |
1337 | the definition. Use @code{def-body} for the highest level list of forms | |
1338 | within the definition. | |
1339 | ||
1340 | @item def-form | |
1341 | The argument is a single, highest-level form in a definition. This is | |
1342 | like @code{def-body}, except use this to match a single form rather than | |
1343 | a list of forms. As a special case, @code{def-form} also means that | |
1344 | tracing information is not output when the form is executed. See the | |
1345 | @code{interactive} example below. | |
1346 | @end table | |
1347 | ||
1348 | @node Backtracking | |
969fe9b5 | 1349 | @subsubsection Backtracking in Specifications |
73804d4b RS |
1350 | |
1351 | @cindex backtracking | |
1352 | @cindex syntax error (Edebug) | |
1353 | If a specification fails to match at some point, this does not | |
1354 | necessarily mean a syntax error will be signaled; instead, | |
1355 | @dfn{backtracking} will take place until all alternatives have been | |
1356 | exhausted. Eventually every element of the argument list must be | |
1357 | matched by some element in the specification, and every required element | |
1358 | in the specification must match some argument. | |
177c0ea7 | 1359 | |
a9f0a989 RS |
1360 | When a syntax error is detected, it might not be reported until much |
1361 | later after higher-level alternatives have been exhausted, and with the | |
1362 | point positioned further from the real error. But if backtracking is | |
1363 | disabled when an error occurs, it can be reported immediately. Note | |
1364 | that backtracking is also reenabled automatically in several situations; | |
1365 | it is reenabled when a new alternative is established by | |
1366 | @code{&optional}, @code{&rest}, or @code{&or}, or at the start of | |
1367 | processing a sublist, group, or indirect specification. The effect of | |
1368 | enabling or disabling backtracking is limited to the remainder of the | |
1369 | level currently being processed and lower levels. | |
1370 | ||
1371 | Backtracking is disabled while matching any of the | |
1372 | form specifications (that is, @code{form}, @code{body}, @code{def-form}, and | |
73804d4b RS |
1373 | @code{def-body}). These specifications will match any form so any error |
1374 | must be in the form itself rather than at a higher level. | |
1375 | ||
a9f0a989 | 1376 | Backtracking is also disabled after successfully matching a quoted |
73804d4b | 1377 | symbol or string specification, since this usually indicates a |
a9f0a989 | 1378 | recognized construct. But if you have a set of alternative constructs that |
73804d4b RS |
1379 | all begin with the same symbol, you can usually work around this |
1380 | constraint by factoring the symbol out of the alternatives, e.g., | |
1381 | @code{["foo" &or [first case] [second case] ...]}. | |
1382 | ||
3e7274ae | 1383 | Most needs are satisfied by these two ways that backtracking is |
a9f0a989 RS |
1384 | automatically disabled, but occasionally it is useful to explicitly |
1385 | disable backtracking by using the @code{gate} specification. This is | |
1386 | useful when you know that no higher alternatives could apply. See the | |
1387 | example of the @code{let} specification. | |
73804d4b | 1388 | |
73804d4b RS |
1389 | @node Specification Examples |
1390 | @subsubsection Specification Examples | |
1391 | ||
1392 | It may be easier to understand Edebug specifications by studying | |
1393 | the examples provided here. | |
1394 | ||
1395 | A @code{let} special form has a sequence of bindings and a body. Each | |
1396 | of the bindings is either a symbol or a sublist with a symbol and | |
a9f0a989 | 1397 | optional expression. In the specification below, notice the @code{gate} |
73804d4b RS |
1398 | inside of the sublist to prevent backtracking once a sublist is found. |
1399 | ||
1400 | @example | |
1401 | (def-edebug-spec let | |
1402 | ((&rest | |
1403 | &or symbolp (gate symbolp &optional form)) | |
1404 | body)) | |
1405 | @end example | |
1406 | ||
1407 | Edebug uses the following specifications for @code{defun} and | |
1408 | @code{defmacro} and the associated argument list and @code{interactive} | |
1409 | specifications. It is necessary to handle interactive forms specially | |
1410 | since an expression argument it is actually evaluated outside of the | |
1411 | function body. | |
1412 | ||
87b2d5ff RS |
1413 | @smallexample |
1414 | (def-edebug-spec defmacro defun) ; @r{Indirect ref to @code{defun} spec.} | |
177c0ea7 JB |
1415 | (def-edebug-spec defun |
1416 | (&define name lambda-list | |
87b2d5ff | 1417 | [&optional stringp] ; @r{Match the doc string, if present.} |
73804d4b RS |
1418 | [&optional ("interactive" interactive)] |
1419 | def-body)) | |
1420 | ||
1421 | (def-edebug-spec lambda-list | |
1422 | (([&rest arg] | |
1423 | [&optional ["&optional" arg &rest arg]] | |
1424 | &optional ["&rest" arg] | |
1425 | ))) | |
1426 | ||
1427 | (def-edebug-spec interactive | |
1428 | (&optional &or stringp def-form)) ; @r{Notice: @code{def-form}} | |
87b2d5ff | 1429 | @end smallexample |
73804d4b RS |
1430 | |
1431 | The specification for backquote below illustrates how to match | |
1432 | dotted lists and use @code{nil} to terminate recursion. It also | |
1433 | illustrates how components of a vector may be matched. (The actual | |
1434 | specification defined by Edebug does not support dotted lists because | |
1435 | doing so causes very deep recursion that could fail.) | |
1436 | ||
87b2d5ff RS |
1437 | @smallexample |
1438 | (def-edebug-spec ` (backquote-form)) ; @r{Alias just for clarity.} | |
73804d4b RS |
1439 | |
1440 | (def-edebug-spec backquote-form | |
1441 | (&or ([&or "," ",@@"] &or ("quote" backquote-form) form) | |
1442 | (backquote-form . [&or nil backquote-form]) | |
1443 | (vector &rest backquote-form) | |
1444 | sexp)) | |
87b2d5ff | 1445 | @end smallexample |
73804d4b RS |
1446 | |
1447 | ||
1448 | @node Edebug Options | |
1449 | @subsection Edebug Options | |
1450 | ||
1451 | These options affect the behavior of Edebug: | |
1452 | ||
1453 | @defopt edebug-setup-hook | |
1454 | Functions to call before Edebug is used. Each time it is set to a new | |
1455 | value, Edebug will call those functions once and then | |
1456 | @code{edebug-setup-hook} is reset to @code{nil}. You could use this to | |
1457 | load up Edebug specifications associated with a package you are using | |
1458 | but only when you also use Edebug. | |
1459 | @xref{Instrumenting}. | |
1460 | @end defopt | |
1461 | ||
1462 | @defopt edebug-all-defs | |
1463 | If this is non-@code{nil}, normal evaluation of defining forms such as | |
1464 | @code{defun} and @code{defmacro} instruments them for Edebug. This | |
87b2d5ff RS |
1465 | applies to @code{eval-defun}, @code{eval-region}, @code{eval-buffer}, |
1466 | and @code{eval-current-buffer}. | |
1467 | ||
1468 | Use the command @kbd{M-x edebug-all-defs} to toggle the value of this | |
1469 | option. @xref{Instrumenting}. | |
73804d4b RS |
1470 | @end defopt |
1471 | ||
1472 | @defopt edebug-all-forms | |
87b2d5ff RS |
1473 | If this is non-@code{nil}, the commands @code{eval-defun}, |
1474 | @code{eval-region}, @code{eval-buffer}, and @code{eval-current-buffer} | |
1475 | instrument all forms, even those that don't define anything. | |
1476 | This doesn't apply to loading or evaluations in the minibuffer. | |
73804d4b RS |
1477 | |
1478 | Use the command @kbd{M-x edebug-all-forms} to toggle the value of this | |
87b2d5ff | 1479 | option. @xref{Instrumenting}. |
73804d4b RS |
1480 | @end defopt |
1481 | ||
1482 | @defopt edebug-save-windows | |
1483 | If this is non-@code{nil}, Edebug saves and restores the window | |
1484 | configuration. That takes some time, so if your program does not care | |
1485 | what happens to the window configurations, it is better to set this | |
1486 | variable to @code{nil}. | |
1487 | ||
1488 | If the value is a list, only the listed windows are saved and | |
177c0ea7 | 1489 | restored. |
73804d4b RS |
1490 | |
1491 | You can use the @kbd{W} command in Edebug to change this variable | |
1492 | interactively. @xref{Edebug Display Update}. | |
1493 | @end defopt | |
1494 | ||
1495 | @defopt edebug-save-displayed-buffer-points | |
87b2d5ff RS |
1496 | If this is non-@code{nil}, Edebug saves and restores point in all |
1497 | displayed buffers. | |
73804d4b RS |
1498 | |
1499 | Saving and restoring point in other buffers is necessary if you are | |
1500 | debugging code that changes the point of a buffer which is displayed in | |
1501 | a non-selected window. If Edebug or the user then selects the window, | |
87b2d5ff | 1502 | point in that buffer will move to the window's value of point. |
73804d4b RS |
1503 | |
1504 | Saving and restoring point in all buffers is expensive, since it | |
1505 | requires selecting each window twice, so enable this only if you need | |
1506 | it. @xref{Edebug Display Update}. | |
1507 | @end defopt | |
1508 | ||
1509 | @defopt edebug-initial-mode | |
1510 | If this variable is non-@code{nil}, it specifies the initial execution | |
1511 | mode for Edebug when it is first activated. Possible values are | |
1512 | @code{step}, @code{next}, @code{go}, @code{Go-nonstop}, @code{trace}, | |
1513 | @code{Trace-fast}, @code{continue}, and @code{Continue-fast}. | |
1514 | ||
177c0ea7 | 1515 | The default value is @code{step}. |
73804d4b RS |
1516 | @xref{Edebug Execution Modes}. |
1517 | @end defopt | |
1518 | ||
1519 | @defopt edebug-trace | |
73804d4b RS |
1520 | Non-@code{nil} means display a trace of function entry and exit. |
1521 | Tracing output is displayed in a buffer named @samp{*edebug-trace*}, one | |
177c0ea7 | 1522 | function entry or exit per line, indented by the recursion level. |
73804d4b | 1523 | |
177c0ea7 | 1524 | The default value is @code{nil}. |
73804d4b | 1525 | |
a9f0a989 | 1526 | Also see @code{edebug-tracing}, in @ref{Trace Buffer}. |
73804d4b RS |
1527 | @end defopt |
1528 | ||
177c0ea7 | 1529 | @defopt edebug-test-coverage |
73804d4b | 1530 | If non-@code{nil}, Edebug tests coverage of all expressions debugged. |
73804d4b RS |
1531 | @xref{Coverage Testing}. |
1532 | @end defopt | |
1533 | ||
177c0ea7 | 1534 | @defopt edebug-continue-kbd-macro |
73804d4b RS |
1535 | If non-@code{nil}, continue defining or executing any keyboard macro |
1536 | that is executing outside of Edebug. Use this with caution since it is not | |
1537 | debugged. | |
1538 | @xref{Edebug Execution Modes}. | |
1539 | @end defopt | |
1540 | ||
73804d4b RS |
1541 | @defopt edebug-on-error |
1542 | Edebug binds @code{debug-on-error} to this value, if | |
1543 | @code{debug-on-error} was previously @code{nil}. @xref{Trapping | |
1544 | Errors}. | |
1545 | @end defopt | |
1546 | ||
1547 | @defopt edebug-on-quit | |
1548 | Edebug binds @code{debug-on-quit} to this value, if | |
1549 | @code{debug-on-quit} was previously @code{nil}. @xref{Trapping | |
1550 | Errors}. | |
1551 | @end defopt | |
1552 | ||
1553 | If you change the values of @code{edebug-on-error} or | |
1554 | @code{edebug-on-quit} while Edebug is active, their values won't be used | |
87b2d5ff RS |
1555 | until the @emph{next} time Edebug is invoked via a new command. |
1556 | @c Not necessarily a deeper command level. | |
1557 | @c A new command is not precisely true, but that is close enough -- dan | |
73804d4b RS |
1558 | |
1559 | @defopt edebug-global-break-condition | |
9a8dc0d3 RS |
1560 | If non-@code{nil}, an expression to test for at every stop point. If |
1561 | the result is non-@code{nil}, then break. Errors are ignored. | |
73804d4b RS |
1562 | @xref{Global Break Condition}. |
1563 | @end defopt | |
ab5796a9 MB |
1564 | |
1565 | @ignore | |
1566 | arch-tag: 74842db8-019f-4818-b5a4-b2de878e57fd | |
1567 | @end ignore |