Merge from trunk.
[bpt/emacs.git] / lisp / emacs-lisp / find-func.el
1 ;;; find-func.el --- find the definition of the Emacs Lisp function near point
2
3 ;; Copyright (C) 1997, 1999, 2001-2011 Free Software Foundation, Inc.
4
5 ;; Author: Jens Petersen <petersen@kurims.kyoto-u.ac.jp>
6 ;; Maintainer: petersen@kurims.kyoto-u.ac.jp
7 ;; Keywords: emacs-lisp, functions, variables
8 ;; Created: 97/07/25
9
10 ;; This file is part of GNU Emacs.
11
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
16
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
21
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
24
25 ;;; Commentary:
26 ;;
27 ;; The funniest thing about this is that I can't imagine why a package
28 ;; so obviously useful as this hasn't been written before!!
29 ;; ;;; find-func
30 ;; (find-function-setup-keys)
31 ;;
32 ;; or just:
33 ;;
34 ;; (load "find-func")
35 ;;
36 ;; if you don't like the given keybindings and away you go! It does
37 ;; pretty much what you would expect, putting the cursor at the
38 ;; definition of the function or variable at point.
39 ;;
40 ;; The code started out from `describe-function', `describe-key'
41 ;; ("help.el") and `fff-find-loaded-emacs-lisp-function' (Noah Friedman's
42 ;; "fff.el").
43
44 ;;; Code:
45
46 ;;; User variables:
47
48 (defgroup find-function nil
49 "Finds the definition of the Emacs Lisp symbol near point."
50 ;; :prefix "find-function"
51 :group 'lisp)
52
53 (defconst find-function-space-re "\\(?:\\s-\\|\n\\|;.*\n\\)+")
54
55 (defcustom find-function-regexp
56 ;; Match things like (defun foo ...), (defmacro foo ...),
57 ;; (define-skeleton foo ...), (define-generic-mode 'foo ...),
58 ;; (define-derived-mode foo ...), (define-minor-mode foo)
59 (concat
60 "^\\s-*(\\(def\\(ine-skeleton\\|ine-generic-mode\\|ine-derived-mode\\|\
61 ine\\(?:-global\\)?-minor-mode\\|ine-compilation-mode\\|un-cvs-mode\\|\
62 foo\\|[^icfgv]\\(\\w\\|\\s_\\)+\\*?\\)\\|easy-mmode-define-[a-z-]+\\|easy-menu-define\\|\
63 menu-bar-make-toggle\\)"
64 find-function-space-re
65 "\\('\\|\(quote \\)?%s\\(\\s-\\|$\\|\(\\|\)\\)")
66 "The regexp used by `find-function' to search for a function definition.
67 Note it must contain a `%s' at the place where `format'
68 should insert the function name. The default value avoids `defconst',
69 `defgroup', `defvar', `defface'.
70
71 Please send improvements and fixes to the maintainer."
72 :type 'regexp
73 :group 'find-function
74 :version "21.1")
75
76 (defcustom find-variable-regexp
77 (concat
78 "^\\s-*(\\(def[^fumag]\\(\\w\\|\\s_\\)+\\*?\\|\
79 easy-mmode-def\\(map\\|syntax\\)\\|easy-menu-define\\)"
80 find-function-space-re
81 "%s\\(\\s-\\|$\\)")
82 "The regexp used by `find-variable' to search for a variable definition.
83 Note it must contain a `%s' at the place where `format'
84 should insert the variable name. The default value
85 avoids `defun', `defmacro', `defalias', `defadvice', `defgroup', `defface'.
86
87 Please send improvements and fixes to the maintainer."
88 :type 'regexp
89 :group 'find-function
90 :version "21.1")
91
92 (defcustom find-face-regexp
93 (concat"^\\s-*(defface" find-function-space-re "%s\\(\\s-\\|$\\)")
94 "The regexp used by `find-face' to search for a face definition.
95 Note it must contain a `%s' at the place where `format'
96 should insert the face name.
97
98 Please send improvements and fixes to the maintainer."
99 :type 'regexp
100 :group 'find-function
101 :version "22.1")
102
103 (defvar find-function-regexp-alist
104 '((nil . find-function-regexp)
105 (defvar . find-variable-regexp)
106 (defface . find-face-regexp))
107 "Alist mapping definition types into regexp variables.
108 Each regexp variable's value should actually be a format string
109 to be used to substitute the desired symbol name into the regexp.")
110 (put 'find-function-regexp-alist 'risky-local-variable t)
111
112 (defcustom find-function-source-path nil
113 "The default list of directories where `find-function' searches.
114
115 If this variable is nil then `find-function' searches `load-path' by
116 default."
117 :type '(repeat directory)
118 :group 'find-function)
119
120 (defcustom find-function-recenter-line 1
121 "The window line-number from which to start displaying a symbol definition.
122 A value of nil implies center the beginning of the definition.
123 See `find-function' and `find-variable'."
124 :type '(choice (const :tag "Center" nil)
125 integer)
126 :group 'find-function
127 :version "20.3")
128
129 (defcustom find-function-after-hook nil
130 "Hook run after finding symbol definition.
131
132 See the functions `find-function' and `find-variable'."
133 :type 'hook
134 :group 'find-function
135 :version "20.3")
136
137 ;;; Functions:
138
139 (defun find-library-suffixes ()
140 (let ((suffixes nil))
141 (dolist (suffix (get-load-suffixes) (nreverse suffixes))
142 (unless (string-match "elc" suffix) (push suffix suffixes)))))
143
144 (defun find-library--load-name (library)
145 (let ((name library))
146 (dolist (dir load-path)
147 (let ((rel (file-relative-name library dir)))
148 (if (and (not (string-match "\\`\\.\\./" rel))
149 (< (length rel) (length name)))
150 (setq name rel))))
151 (unless (equal name library) name)))
152
153 (defun find-library-name (library)
154 "Return the absolute file name of the Emacs Lisp source of LIBRARY.
155 LIBRARY should be a string (the name of the library)."
156 ;; If the library is byte-compiled, try to find a source library by
157 ;; the same name.
158 (if (string-match "\\.el\\(c\\(\\..*\\)?\\)\\'" library)
159 (setq library (replace-match "" t t library)))
160 (or
161 (locate-file library
162 (or find-function-source-path load-path)
163 (find-library-suffixes))
164 (locate-file library
165 (or find-function-source-path load-path)
166 load-file-rep-suffixes)
167 (when (file-name-absolute-p library)
168 (let ((rel (find-library--load-name library)))
169 (when rel
170 (or
171 (locate-file rel
172 (or find-function-source-path load-path)
173 (find-library-suffixes))
174 (locate-file rel
175 (or find-function-source-path load-path)
176 load-file-rep-suffixes)))))
177 (error "Can't find library %s" library)))
178
179 (defvar find-function-C-source-directory
180 (let ((dir (expand-file-name "src" source-directory)))
181 (when (and (file-directory-p dir) (file-readable-p dir))
182 dir))
183 "Directory where the C source files of Emacs can be found.
184 If nil, do not try to find the source code of functions and variables
185 defined in C.")
186
187 (declare-function ad-get-advice-info "advice" (function))
188
189 (defun find-function-advised-original (func)
190 "Return the original function symbol of an advised function FUNC.
191 If FUNC is not the symbol of an advised function, just returns FUNC."
192 (or (and (symbolp func)
193 (featurep 'advice)
194 (let ((ofunc (cdr (assq 'origname (ad-get-advice-info func)))))
195 (and (fboundp ofunc) ofunc)))
196 func))
197
198 (defun find-function-C-source (fun-or-var file type)
199 "Find the source location where FUN-OR-VAR is defined in FILE.
200 TYPE should be nil to find a function, or `defvar' to find a variable."
201 (unless find-function-C-source-directory
202 (setq find-function-C-source-directory
203 (read-directory-name "Emacs C source dir: " nil nil t)))
204 (setq file (expand-file-name file find-function-C-source-directory))
205 (unless (file-readable-p file)
206 (error "The C source file %s is not available"
207 (file-name-nondirectory file)))
208 (unless type
209 ;; Either or both an alias and its target might be advised.
210 (setq fun-or-var (find-function-advised-original
211 (indirect-function
212 (find-function-advised-original fun-or-var)))))
213 (with-current-buffer (find-file-noselect file)
214 (goto-char (point-min))
215 (unless (re-search-forward
216 (if type
217 (concat "DEFVAR[A-Z_]*[ \t\n]*([ \t\n]*\""
218 (regexp-quote (symbol-name fun-or-var))
219 "\"")
220 (concat "DEFUN[ \t\n]*([ \t\n]*\""
221 (regexp-quote (subr-name fun-or-var))
222 "\""))
223 nil t)
224 (error "Can't find source for %s" fun-or-var))
225 (cons (current-buffer) (match-beginning 0))))
226
227 ;;;###autoload
228 (defun find-library (library)
229 "Find the Emacs Lisp source of LIBRARY.
230 LIBRARY should be a string (the name of the library)."
231 (interactive
232 (let* ((dirs (or find-function-source-path load-path))
233 (suffixes (find-library-suffixes))
234 (table (apply-partially 'locate-file-completion-table
235 dirs suffixes))
236 (def (if (eq (function-called-at-point) 'require)
237 ;; `function-called-at-point' may return 'require
238 ;; with `point' anywhere on this line. So wrap the
239 ;; `save-excursion' below in a `condition-case' to
240 ;; avoid reporting a scan-error here.
241 (condition-case nil
242 (save-excursion
243 (backward-up-list)
244 (forward-char)
245 (forward-sexp 2)
246 (thing-at-point 'symbol))
247 (error nil))
248 (thing-at-point 'symbol))))
249 (when (and def (not (test-completion def table)))
250 (setq def nil))
251 (list
252 (completing-read (if def (format "Library name (default %s): " def)
253 "Library name: ")
254 table nil nil nil nil def))))
255 (let ((buf (find-file-noselect (find-library-name library))))
256 (condition-case nil (switch-to-buffer buf) (error (pop-to-buffer buf)))))
257
258 ;;;###autoload
259 (defun find-function-search-for-symbol (symbol type library)
260 "Search for SYMBOL's definition of type TYPE in LIBRARY.
261 Visit the library in a buffer, and return a cons cell (BUFFER . POSITION),
262 or just (BUFFER . nil) if the definition can't be found in the file.
263
264 If TYPE is nil, look for a function definition.
265 Otherwise, TYPE specifies the kind of definition,
266 and it is interpreted via `find-function-regexp-alist'.
267 The search is done in the source for library LIBRARY."
268 (if (null library)
269 (error "Don't know where `%s' is defined" symbol))
270 ;; Some functions are defined as part of the construct
271 ;; that defines something else.
272 (while (and (symbolp symbol) (get symbol 'definition-name))
273 (setq symbol (get symbol 'definition-name)))
274 (if (string-match "\\`src/\\(.*\\.\\(c\\|m\\)\\)\\'" library)
275 (find-function-C-source symbol (match-string 1 library) type)
276 (when (string-match "\\.el\\(c\\)\\'" library)
277 (setq library (substring library 0 (match-beginning 1))))
278 ;; Strip extension from .emacs.el to make sure symbol is searched in
279 ;; .emacs too.
280 (when (string-match "\\.emacs\\(.el\\)" library)
281 (setq library (substring library 0 (match-beginning 1))))
282 (let* ((filename (find-library-name library))
283 (regexp-symbol (cdr (assq type find-function-regexp-alist))))
284 (with-current-buffer (find-file-noselect filename)
285 (let ((regexp (format (symbol-value regexp-symbol)
286 ;; Entry for ` (backquote) macro in loaddefs.el,
287 ;; (defalias (quote \`)..., has a \ but
288 ;; (symbol-name symbol) doesn't. Add an
289 ;; optional \ to catch this.
290 (concat "\\\\?"
291 (regexp-quote (symbol-name symbol)))))
292 (case-fold-search))
293 (with-syntax-table emacs-lisp-mode-syntax-table
294 (goto-char (point-min))
295 (if (or (re-search-forward regexp nil t)
296 ;; `regexp' matches definitions using known forms like
297 ;; `defun', or `defvar'. But some functions/variables
298 ;; are defined using special macros (or functions), so
299 ;; if `regexp' can't find the definition, we look for
300 ;; something of the form "(SOMETHING <symbol> ...)".
301 ;; This fails to distinguish function definitions from
302 ;; variable declarations (or even uses thereof), but is
303 ;; a good pragmatic fallback.
304 (re-search-forward
305 (concat "^([^ ]+" find-function-space-re "['(]?"
306 (regexp-quote (symbol-name symbol))
307 "\\_>")
308 nil t))
309 (progn
310 (beginning-of-line)
311 (cons (current-buffer) (point)))
312 (cons (current-buffer) nil))))))))
313
314 ;;;###autoload
315 (defun find-function-noselect (function &optional lisp-only)
316 "Return a pair (BUFFER . POINT) pointing to the definition of FUNCTION.
317
318 Finds the source file containing the definition of FUNCTION
319 in a buffer and the point of the definition. The buffer is
320 not selected. If the function definition can't be found in
321 the buffer, returns (BUFFER).
322
323 If FUNCTION is a built-in function, this function normally
324 attempts to find it in the Emacs C sources; however, if LISP-ONLY
325 is non-nil, signal an error instead.
326
327 If the file where FUNCTION is defined is not known, then it is
328 searched for in `find-function-source-path' if non-nil, otherwise
329 in `load-path'."
330 (if (not function)
331 (error "You didn't specify a function"))
332 (let ((def (symbol-function (find-function-advised-original function)))
333 aliases)
334 ;; FIXME for completeness, it might be nice to print something like:
335 ;; foo (which is advised), which is an alias for bar (which is advised).
336 (while (symbolp def)
337 (or (eq def function)
338 (if aliases
339 (setq aliases (concat aliases
340 (format ", which is an alias for `%s'"
341 (symbol-name def))))
342 (setq aliases (format "`%s' is an alias for `%s'"
343 function (symbol-name def)))))
344 (setq function (symbol-function (find-function-advised-original function))
345 def (symbol-function (find-function-advised-original function))))
346 (if aliases
347 (message "%s" aliases))
348 (let ((library
349 (cond ((eq (car-safe def) 'autoload)
350 (nth 1 def))
351 ((subrp def)
352 (if lisp-only
353 (error "%s is a built-in function" function))
354 (help-C-file-name def 'subr))
355 ((symbol-file function 'defun)))))
356 (find-function-search-for-symbol function nil library))))
357
358 (defun find-function-read (&optional type)
359 "Read and return an interned symbol, defaulting to the one near point.
360
361 If TYPE is nil, insist on a symbol with a function definition.
362 Otherwise TYPE should be `defvar' or `defface'.
363 If TYPE is nil, defaults using `function-called-at-point',
364 otherwise uses `variable-at-point'."
365 (let ((symb (if (null type)
366 (function-called-at-point)
367 (if (eq type 'defvar)
368 (variable-at-point)
369 (variable-at-point t))))
370 (predicate (cdr (assq type '((nil . fboundp) (defvar . boundp)
371 (defface . facep)))))
372 (prompt (cdr (assq type '((nil . "function") (defvar . "variable")
373 (defface . "face")))))
374 (enable-recursive-minibuffers t)
375 val)
376 (if (equal symb 0)
377 (setq symb nil))
378 (setq val (completing-read
379 (concat "Find "
380 prompt
381 (if symb
382 (format " (default %s)" symb))
383 ": ")
384 obarray predicate t nil))
385 (list (if (equal val "")
386 symb
387 (intern val)))))
388
389 (defun find-function-do-it (symbol type switch-fn)
390 "Find Emacs Lisp SYMBOL in a buffer and display it.
391 TYPE is nil to search for a function definition,
392 or else `defvar' or `defface'.
393
394 The variable `find-function-recenter-line' controls how
395 to recenter the display. SWITCH-FN is the function to call
396 to display and select the buffer.
397 See also `find-function-after-hook'.
398
399 Set mark before moving, if the buffer already existed."
400 (let* ((orig-point (point))
401 (orig-buf (window-buffer))
402 (orig-buffers (buffer-list))
403 (buffer-point (save-excursion
404 (find-definition-noselect symbol type)))
405 (new-buf (car buffer-point))
406 (new-point (cdr buffer-point)))
407 (when buffer-point
408 (when (memq new-buf orig-buffers)
409 (push-mark orig-point))
410 (funcall switch-fn new-buf)
411 (when new-point (goto-char new-point))
412 (recenter find-function-recenter-line)
413 (run-hooks 'find-function-after-hook))))
414
415 ;;;###autoload
416 (defun find-function (function)
417 "Find the definition of the FUNCTION near point.
418
419 Finds the source file containing the definition of the function
420 near point (selected by `function-called-at-point') in a buffer and
421 places point before the definition.
422 Set mark before moving, if the buffer already existed.
423
424 The library where FUNCTION is defined is searched for in
425 `find-function-source-path', if non-nil, otherwise in `load-path'.
426 See also `find-function-recenter-line' and `find-function-after-hook'."
427 (interactive (find-function-read))
428 (find-function-do-it function nil 'switch-to-buffer))
429
430 ;;;###autoload
431 (defun find-function-other-window (function)
432 "Find, in another window, the definition of FUNCTION near point.
433
434 See `find-function' for more details."
435 (interactive (find-function-read))
436 (find-function-do-it function nil 'switch-to-buffer-other-window))
437
438 ;;;###autoload
439 (defun find-function-other-frame (function)
440 "Find, in another frame, the definition of FUNCTION near point.
441
442 See `find-function' for more details."
443 (interactive (find-function-read))
444 (find-function-do-it function nil 'switch-to-buffer-other-frame))
445
446 ;;;###autoload
447 (defun find-variable-noselect (variable &optional file)
448 "Return a pair `(BUFFER . POINT)' pointing to the definition of VARIABLE.
449
450 Finds the library containing the definition of VARIABLE in a buffer and
451 the point of the definition. The buffer is not selected.
452 If the variable's definition can't be found in the buffer, return (BUFFER).
453
454 The library where VARIABLE is defined is searched for in FILE or
455 `find-function-source-path', if non-nil, otherwise in `load-path'."
456 (if (not variable)
457 (error "You didn't specify a variable")
458 (let ((library (or file
459 (symbol-file variable 'defvar)
460 (help-C-file-name variable 'var))))
461 (find-function-search-for-symbol variable 'defvar library))))
462
463 ;;;###autoload
464 (defun find-variable (variable)
465 "Find the definition of the VARIABLE at or before point.
466
467 Finds the library containing the definition of the variable
468 near point (selected by `variable-at-point') in a buffer and
469 places point before the definition.
470
471 Set mark before moving, if the buffer already existed.
472
473 The library where VARIABLE is defined is searched for in
474 `find-function-source-path', if non-nil, otherwise in `load-path'.
475 See also `find-function-recenter-line' and `find-function-after-hook'."
476 (interactive (find-function-read 'defvar))
477 (find-function-do-it variable 'defvar 'switch-to-buffer))
478
479 ;;;###autoload
480 (defun find-variable-other-window (variable)
481 "Find, in another window, the definition of VARIABLE near point.
482
483 See `find-variable' for more details."
484 (interactive (find-function-read 'defvar))
485 (find-function-do-it variable 'defvar 'switch-to-buffer-other-window))
486
487 ;;;###autoload
488 (defun find-variable-other-frame (variable)
489 "Find, in another frame, the definition of VARIABLE near point.
490
491 See `find-variable' for more details."
492 (interactive (find-function-read 'defvar))
493 (find-function-do-it variable 'defvar 'switch-to-buffer-other-frame))
494
495 ;;;###autoload
496 (defun find-definition-noselect (symbol type &optional file)
497 "Return a pair `(BUFFER . POINT)' pointing to the definition of SYMBOL.
498 If the definition can't be found in the buffer, return (BUFFER).
499 TYPE says what type of definition: nil for a function, `defvar' for a
500 variable, `defface' for a face. This function does not switch to the
501 buffer nor display it.
502
503 The library where SYMBOL is defined is searched for in FILE or
504 `find-function-source-path', if non-nil, otherwise in `load-path'."
505 (cond
506 ((not symbol)
507 (error "You didn't specify a symbol"))
508 ((null type)
509 (find-function-noselect symbol))
510 ((eq type 'defvar)
511 (find-variable-noselect symbol file))
512 (t
513 (let ((library (or file (symbol-file symbol type))))
514 (find-function-search-for-symbol symbol type library)))))
515
516 ;; For symmetry, this should be called find-face; but some programs
517 ;; assume that, if that name is defined, it means something else.
518 ;;;###autoload
519 (defun find-face-definition (face)
520 "Find the definition of FACE. FACE defaults to the name near point.
521
522 Finds the Emacs Lisp library containing the definition of the face
523 near point (selected by `variable-at-point') in a buffer and
524 places point before the definition.
525
526 Set mark before moving, if the buffer already existed.
527
528 The library where FACE is defined is searched for in
529 `find-function-source-path', if non-nil, otherwise in `load-path'.
530 See also `find-function-recenter-line' and `find-function-after-hook'."
531 (interactive (find-function-read 'defface))
532 (find-function-do-it face 'defface 'switch-to-buffer))
533
534 ;;;###autoload
535 (defun find-function-on-key (key)
536 "Find the function that KEY invokes. KEY is a string.
537 Set mark before moving, if the buffer already existed."
538 (interactive "kFind function on key: ")
539 (let (defn)
540 (save-excursion
541 (let* ((event (and (eventp key) (aref key 0))) ; Null event OK below.
542 (start (event-start event))
543 (modifiers (event-modifiers event))
544 (window (and (or (memq 'click modifiers) (memq 'down modifiers)
545 (memq 'drag modifiers))
546 (posn-window start))))
547 ;; For a mouse button event, go to the button it applies to
548 ;; to get the right key bindings. And go to the right place
549 ;; in case the keymap depends on where you clicked.
550 (when (windowp window)
551 (set-buffer (window-buffer window))
552 (goto-char (posn-point start)))
553 (setq defn (key-binding key))))
554 (let ((key-desc (key-description key)))
555 (if (or (null defn) (integerp defn))
556 (message "%s is unbound" key-desc)
557 (if (consp defn)
558 (message "%s runs %s" key-desc (prin1-to-string defn))
559 (find-function-other-window defn))))))
560
561 ;;;###autoload
562 (defun find-function-at-point ()
563 "Find directly the function at point in the other window."
564 (interactive)
565 (let ((symb (function-called-at-point)))
566 (when symb
567 (find-function-other-window symb))))
568
569 ;;;###autoload
570 (defun find-variable-at-point ()
571 "Find directly the variable at point in the other window."
572 (interactive)
573 (let ((symb (variable-at-point)))
574 (when (and symb (not (equal symb 0)))
575 (find-variable-other-window symb))))
576
577 ;;;###autoload
578 (defun find-function-setup-keys ()
579 "Define some key bindings for the find-function family of functions."
580 (define-key ctl-x-map "F" 'find-function)
581 (define-key ctl-x-4-map "F" 'find-function-other-window)
582 (define-key ctl-x-5-map "F" 'find-function-other-frame)
583 (define-key ctl-x-map "K" 'find-function-on-key)
584 (define-key ctl-x-map "V" 'find-variable)
585 (define-key ctl-x-4-map "V" 'find-variable-other-window)
586 (define-key ctl-x-5-map "V" 'find-variable-other-frame))
587
588 (provide 'find-func)
589
590 ;;; find-func.el ends here