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1 | ;;; debug.el --- debuggers and related commands for Emacs |
2 | ||
9750e079 ER |
3 | ;; Copyright (C) 1985, 1986 Free Software Foundation, Inc. |
4 | ||
e5167999 | 5 | ;; Maintainer: FSF |
fd7fa35a | 6 | ;; Keyword: lisp, tools |
e5167999 | 7 | |
0231f2dc JB |
8 | ;; This file is part of GNU Emacs. |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
e5167999 | 12 | ;; the Free Software Foundation; either version 2, or (at your option) |
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13 | ;; any later version. |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
22 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
23 | ||
e5167999 | 24 | ;;; Code: |
0231f2dc JB |
25 | |
26 | (defvar debug-function-list nil | |
27 | "List of functions currently set for debug on entry.") | |
28 | ||
29 | ;;;###autoload | |
30 | (setq debugger 'debug) | |
31 | ;;;###autoload | |
32 | (defun debug (&rest debugger-args) | |
33 | "Enter debugger. Returns if user says \"continue\". | |
34 | Arguments are mainly for use when this is called from the internals | |
35 | of the evaluator. | |
36 | ||
37 | You may call with no args, or you may pass nil as the first arg and | |
38 | any other args you like. In that case, the list of args after the | |
39 | first will be printed into the backtrace buffer." | |
40 | (message "Entering debugger...") | |
41 | (let (debugger-value | |
42 | (debugger-match-data (match-data)) | |
43 | (debug-on-error nil) | |
44 | (debug-on-quit nil) | |
45 | (debugger-buffer (let ((default-major-mode 'fundamental-mode)) | |
46 | (generate-new-buffer "*Backtrace*"))) | |
47 | (debugger-old-buffer (current-buffer)) | |
48 | (debugger-step-after-exit nil) | |
49 | ;; Don't keep reading from an executing kbd macro! | |
50 | (executing-macro nil) | |
51 | (cursor-in-echo-area nil)) | |
52 | (unwind-protect | |
53 | (save-excursion | |
54 | (save-window-excursion | |
55 | (pop-to-buffer debugger-buffer) | |
56 | (erase-buffer) | |
57 | (let ((standard-output (current-buffer)) | |
58 | (print-escape-newlines t) | |
59 | (print-length 50)) | |
60 | (backtrace)) | |
61 | (goto-char (point-min)) | |
62 | (debugger-mode) | |
63 | (delete-region (point) | |
64 | (progn | |
65 | (search-forward "\n debug(") | |
66 | (forward-line 1) | |
67 | (point))) | |
68 | (debugger-reenable) | |
69 | (cond ((memq (car debugger-args) '(lambda debug)) | |
70 | (insert "Entering:\n") | |
71 | (if (eq (car debugger-args) 'debug) | |
72 | (progn | |
73 | (backtrace-debug 4 t) | |
74 | (delete-char 1) | |
75 | (insert ?*) | |
76 | (beginning-of-line)))) | |
77 | ((eq (car debugger-args) 'exit) | |
78 | (insert "Return value: ") | |
79 | (setq debugger-value (nth 1 debugger-args)) | |
80 | (prin1 debugger-value (current-buffer)) | |
81 | (insert ?\n) | |
82 | (delete-char 1) | |
83 | (insert ? ) | |
84 | (beginning-of-line)) | |
85 | ((eq (car debugger-args) 'error) | |
86 | (insert "Signalling: ") | |
87 | (prin1 (nth 1 debugger-args) (current-buffer)) | |
88 | (insert ?\n)) | |
89 | ((eq (car debugger-args) t) | |
90 | (insert "Beginning evaluation of function call form:\n")) | |
91 | (t | |
92 | (prin1 (if (eq (car debugger-args) 'nil) | |
93 | (cdr debugger-args) debugger-args) | |
94 | (current-buffer)) | |
95 | (insert ?\n))) | |
96 | (message "") | |
97 | (let ((inhibit-trace t) | |
98 | (standard-output nil) | |
99 | (buffer-read-only t)) | |
100 | (message "") | |
101 | (recursive-edit)))) | |
102 | ;; So that users do not try to execute debugger commands | |
103 | ;; in an invalid context | |
104 | (kill-buffer debugger-buffer) | |
105 | (store-match-data debugger-match-data)) | |
106 | (setq debug-on-next-call debugger-step-after-exit) | |
107 | debugger-value)) | |
108 | \f | |
109 | (defun debugger-step-through () | |
110 | "Proceed, stepping through subexpressions of this expression. | |
111 | Enter another debugger on next entry to eval, apply or funcall." | |
112 | (interactive) | |
113 | (setq debugger-step-after-exit t) | |
114 | (message "Proceeding, will debug on next eval or call.") | |
115 | (exit-recursive-edit)) | |
116 | ||
117 | (defun debugger-continue () | |
118 | "Continue, evaluating this expression without stopping." | |
119 | (interactive) | |
120 | (message "Continuing.") | |
121 | (exit-recursive-edit)) | |
122 | ||
123 | (defun debugger-return-value (val) | |
124 | "Continue, specifying value to return. | |
125 | This is only useful when the value returned from the debugger | |
126 | will be used, such as in a debug on exit from a frame." | |
127 | (interactive "XReturn value (evaluated): ") | |
128 | (setq debugger-value val) | |
129 | (princ "Returning " t) | |
130 | (prin1 debugger-value) | |
131 | (exit-recursive-edit)) | |
132 | ||
133 | (defun debugger-jump () | |
134 | "Continue to exit from this frame, with all debug-on-entry suspended." | |
135 | (interactive) | |
136 | ;; Compensate for the two extra stack frames for debugger-jump. | |
137 | (let ((debugger-frame-offset (+ debugger-frame-offset 2))) | |
138 | (debugger-frame)) | |
139 | ;; Turn off all debug-on-entry functions | |
140 | ;; but leave them in the list. | |
141 | (let ((list debug-function-list)) | |
142 | (while list | |
143 | (fset (car list) | |
144 | (debug-on-entry-1 (car list) (symbol-function (car list)) nil)) | |
145 | (setq list (cdr list)))) | |
146 | (message "Continuing through this frame") | |
147 | (exit-recursive-edit)) | |
148 | ||
149 | (defun debugger-reenable () | |
150 | "Turn all debug-on-entry functions back on." | |
151 | (let ((list debug-function-list)) | |
152 | (while list | |
153 | (or (consp (symbol-function (car list))) | |
154 | (debug-convert-byte-code (car list))) | |
155 | (fset (car list) | |
156 | (debug-on-entry-1 (car list) (symbol-function (car list)) t)) | |
157 | (setq list (cdr list))))) | |
158 | ||
159 | (defun debugger-frame-number () | |
160 | "Return number of frames in backtrace before the one point points at." | |
161 | (save-excursion | |
162 | (beginning-of-line) | |
163 | (let ((opoint (point)) | |
164 | (count 0)) | |
165 | (goto-char (point-min)) | |
166 | (if (or (equal (buffer-substring (point) (+ (point) 6)) | |
167 | "Signal") | |
168 | (equal (buffer-substring (point) (+ (point) 6)) | |
169 | "Return")) | |
170 | (progn | |
171 | (search-forward ":") | |
172 | (forward-sexp 1))) | |
173 | (forward-line 1) | |
174 | (while (progn | |
175 | (forward-char 2) | |
176 | (if (= (following-char) ?\() | |
177 | (forward-sexp 1) | |
178 | (forward-sexp 2)) | |
179 | (forward-line 1) | |
180 | (<= (point) opoint)) | |
181 | (setq count (1+ count))) | |
182 | count))) | |
183 | ||
184 | ;; Chosen empirically to account for all the frames | |
185 | ;; that will exist when debugger-frame is called | |
186 | ;; within the first one that appears in the backtrace buffer. | |
187 | ;; Assumes debugger-frame is called from a key; | |
188 | ;; will be wrong if it is called with Meta-x. | |
189 | (defconst debugger-frame-offset 8 "") | |
190 | ||
191 | (defun debugger-frame () | |
192 | "Request entry to debugger when this frame exits. | |
193 | Applies to the frame whose line point is on in the backtrace." | |
194 | (interactive) | |
195 | (beginning-of-line) | |
196 | (let ((level (debugger-frame-number))) | |
197 | (backtrace-debug (+ level debugger-frame-offset) t)) | |
198 | (if (= (following-char) ? ) | |
199 | (let ((buffer-read-only nil)) | |
200 | (delete-char 1) | |
201 | (insert ?*))) | |
202 | (beginning-of-line)) | |
203 | ||
204 | (defun debugger-frame-clear () | |
205 | "Do not enter to debugger when this frame exits. | |
206 | Applies to the frame whose line point is on in the backtrace." | |
207 | (interactive) | |
208 | (beginning-of-line) | |
209 | (let ((level (debugger-frame-number))) | |
210 | (backtrace-debug (+ level debugger-frame-offset) nil)) | |
211 | (if (= (following-char) ?*) | |
212 | (let ((buffer-read-only nil)) | |
213 | (delete-char 1) | |
214 | (insert ? ))) | |
215 | (beginning-of-line)) | |
216 | ||
217 | (defun debugger-eval-expression (exp) | |
218 | (interactive "xEval: ") | |
219 | (save-excursion | |
220 | (if (null (buffer-name debugger-old-buffer)) | |
221 | ;; old buffer deleted | |
222 | (setq debugger-old-buffer (current-buffer))) | |
223 | (set-buffer debugger-old-buffer) | |
224 | (eval-expression exp))) | |
225 | \f | |
226 | (defvar debugger-mode-map nil) | |
227 | (if debugger-mode-map | |
228 | nil | |
229 | (let ((loop ? )) | |
230 | (setq debugger-mode-map (make-keymap)) | |
231 | (suppress-keymap debugger-mode-map) | |
232 | (define-key debugger-mode-map "-" 'negative-argument) | |
233 | (define-key debugger-mode-map "b" 'debugger-frame) | |
234 | (define-key debugger-mode-map "c" 'debugger-continue) | |
235 | (define-key debugger-mode-map "j" 'debugger-jump) | |
236 | (define-key debugger-mode-map "r" 'debugger-return-value) | |
237 | (define-key debugger-mode-map "u" 'debugger-frame-clear) | |
238 | (define-key debugger-mode-map "d" 'debugger-step-through) | |
239 | (define-key debugger-mode-map "l" 'debugger-list-functions) | |
240 | (define-key debugger-mode-map "h" 'describe-mode) | |
241 | (define-key debugger-mode-map "q" 'top-level) | |
242 | (define-key debugger-mode-map "e" 'debugger-eval-expression) | |
243 | (define-key debugger-mode-map " " 'next-line))) | |
244 | ||
245 | (put 'debugger-mode 'mode-class 'special) | |
246 | ||
247 | (defun debugger-mode () | |
248 | "Mode for backtrace buffers, selected in debugger. | |
249 | \\<debugger-mode-map> | |
250 | A line starts with `*' if exiting that frame will call the debugger. | |
251 | Type \\[debugger-frame] or \\[debugger-frame-clear] to set or remove the `*'. | |
252 | ||
253 | When in debugger due to frame being exited, | |
254 | use the \\[debugger-return-value] command to override the value | |
255 | being returned from that frame. | |
256 | ||
257 | Use \\[debug-on-entry] and \\[cancel-debug-on-entry] to control | |
258 | which functions will enter the debugger when called. | |
259 | ||
260 | Complete list of commands: | |
261 | \\{debugger-mode-map}" | |
262 | (kill-all-local-variables) | |
263 | (setq major-mode 'debugger-mode) | |
264 | (setq mode-name "Debugger") | |
265 | (setq truncate-lines t) | |
266 | (set-syntax-table emacs-lisp-mode-syntax-table) | |
267 | (use-local-map debugger-mode-map)) | |
268 | \f | |
269 | ;;;###autoload | |
270 | (defun debug-on-entry (function) | |
271 | "Request FUNCTION to invoke debugger each time it is called. | |
272 | If the user continues, FUNCTION's execution proceeds. | |
273 | Works by modifying the definition of FUNCTION, | |
274 | which must be written in Lisp, not predefined. | |
275 | Use \\[cancel-debug-on-entry] to cancel the effect of this command. | |
276 | Redefining FUNCTION also does that." | |
277 | (interactive "aDebug on entry (to function): ") | |
278 | (debugger-reenable) | |
279 | (if (subrp (symbol-function function)) | |
280 | (error "Function %s is a primitive" function)) | |
281 | (or (consp (symbol-function function)) | |
282 | (debug-convert-byte-code function)) | |
283 | (or (consp (symbol-function function)) | |
284 | (error "Definition of %s is not a list" function)) | |
285 | (fset function (debug-on-entry-1 function (symbol-function function) t)) | |
286 | (or (memq function debug-function-list) | |
287 | (setq debug-function-list (cons function debug-function-list))) | |
288 | function) | |
289 | ||
290 | ;;;###autoload | |
291 | (defun cancel-debug-on-entry (&optional function) | |
292 | "Undo effect of \\[debug-on-entry] on FUNCTION. | |
293 | If argument is nil or an empty string, cancel for all functions." | |
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294 | (interactive |
295 | (list (let ((name | |
296 | (completing-read "Cancel debug on entry (to function): " | |
297 | ;; Make an "alist" of the functions | |
298 | ;; that now have debug on entry. | |
299 | (mapcar 'list | |
300 | (mapcar 'symbol-name | |
301 | debug-function-list)) | |
302 | nil t nil))) | |
303 | (if name (intern name))))) | |
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304 | (debugger-reenable) |
305 | (if (and function (not (string= function ""))) | |
306 | (progn | |
307 | (fset function | |
308 | (debug-on-entry-1 function (symbol-function function) nil)) | |
309 | (setq debug-function-list (delq function debug-function-list)) | |
310 | function) | |
311 | (message "Cancelling debug-on-entry for all functions") | |
312 | (mapcar 'cancel-debug-on-entry debug-function-list))) | |
313 | ||
314 | (defun debug-convert-byte-code (function) | |
315 | (let ((defn (symbol-function function))) | |
316 | (if (not (consp defn)) | |
317 | ;; Assume a compiled code object. | |
318 | (let* ((contents (append defn nil)) | |
319 | (body | |
320 | (list (list 'byte-code (nth 1 contents) | |
321 | (nth 2 contents) (nth 3 contents))))) | |
322 | (if (nthcdr 5 contents) | |
323 | (setq body (cons (list 'interactive (nth 5 contents)) body))) | |
324 | (if (nth 4 contents) | |
325 | (setq body (cons (nth 4 contents) body))) | |
326 | (fset function (cons 'lambda (cons (car contents) body))))))) | |
327 | ||
328 | (defun debug-on-entry-1 (function defn flag) | |
329 | (if (subrp defn) | |
330 | (error "%s is a built-in function" function) | |
331 | (if (eq (car defn) 'macro) | |
332 | (debug-on-entry-1 function (cdr defn) flag) | |
333 | (or (eq (car defn) 'lambda) | |
334 | (error "%s not user-defined Lisp function" function)) | |
335 | (let (tail prec) | |
336 | (if (stringp (car (nthcdr 2 defn))) | |
337 | (setq tail (nthcdr 3 defn) | |
338 | prec (list (car defn) (car (cdr defn)) | |
339 | (car (cdr (cdr defn))))) | |
340 | (setq tail (nthcdr 2 defn) | |
341 | prec (list (car defn) (car (cdr defn))))) | |
342 | (if (eq flag (equal (car tail) '(debug 'debug))) | |
343 | defn | |
344 | (if flag | |
345 | (nconc prec (cons '(debug 'debug) tail)) | |
346 | (nconc prec (cdr tail)))))))) | |
347 | ||
348 | (defun debugger-list-functions () | |
349 | "Display a list of all the functions now set to debug on entry." | |
350 | (interactive) | |
351 | (with-output-to-temp-buffer "*Help*" | |
352 | (if (null debug-function-list) | |
353 | (princ "No debug-on-entry functions now\n") | |
354 | (princ "Functions set to debug on entry:\n\n") | |
355 | (let ((list debug-function-list)) | |
356 | (while list | |
357 | (prin1 (car list)) | |
358 | (terpri) | |
359 | (setq list (cdr list)))) | |
360 | (princ "Note: if you have redefined a function, then it may no longer\n") | |
361 | (princ "be set to debug on entry, even if it is in the list.")))) | |
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362 | |
363 | ;;; debug.el ends here |