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1 ;;; find-func.el --- find the definition of the Emacs Lisp function near point
3 ;; Copyright (C) 1997, 1999, 2001-2013 Free Software Foundation, Inc.
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
10 ;; This file is part of GNU Emacs.
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.
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.
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/>.
25 ;;; Commentary:
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)
32 ;; or just:
34 ;; (load "find-func")
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.
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").
44 ;;; Code:
46 ;;; User variables:
48 (defgroup find-function nil
49 "Finds the definition of the Emacs Lisp symbol near point."
50 ;; :prefix "find-function"
51 :group 'lisp)
53 (defconst find-function-space-re "\\(?:\\s-\\|\n\\|;.*\n\\)+")
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'.
71 Please send improvements and fixes to the maintainer."
72 :type 'regexp
73 :group 'find-function
74 :version "21.1")
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-\\|$\\)")
82 "The regexp used by `find-variable' to search for a variable definition.
83 Note it must contain a `%s' at the place where `format'
84 should insert the variable name. The default value
85 avoids `defun', `defmacro', `defalias', `defadvice', `defgroup', `defface'.
87 Please send improvements and fixes to the maintainer."
88 :type 'regexp
89 :group 'find-function
90 :version "21.1")
92 (defcustom find-face-regexp
93 (concat"^\\s-*(defface" find-function-space-re "%s\\(\\s-\\|$\\)")
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.
98 Please send improvements and fixes to the maintainer."
99 :type 'regexp
100 :group 'find-function
101 :version "22.1")
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)
112 (defcustom find-function-source-path nil
113 "The default list of directories where `find-function' searches.
115 If this variable is nil then `find-function' searches `load-path' by
116 default."
117 :type '(repeat directory)
118 :group 'find-function)
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")
129 (defcustom find-function-after-hook nil
130 "Hook run after finding symbol definition.
132 See the functions `find-function' and `find-variable'."
133 :type 'hook
134 :group 'find-function
135 :version "20.3")
137 ;;; Functions:
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)))))
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)))
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)))
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
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)))
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.")
187 (declare-function ad-get-advice-info "advice" (function))
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))
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 (let ((dir (or find-function-C-source-directory
202 (read-directory-name "Emacs C source dir: " nil nil t))))
203 (setq file (expand-file-name file dir))
204 (if (file-readable-p file)
205 (if (null find-function-C-source-directory)
206 (setq find-function-C-source-directory dir))
207 (error "The C source file %s is not available"
208 (file-name-nondirectory file))))
209 (unless type
210 ;; Either or both an alias and its target might be advised.
211 (setq fun-or-var (find-function-advised-original
212 (indirect-function
213 (find-function-advised-original fun-or-var)))))
214 (with-current-buffer (find-file-noselect file)
215 (goto-char (point-min))
216 (unless (re-search-forward
217 (if type
218 (concat "DEFVAR[A-Z_]*[ \t\n]*([ \t\n]*\""
219 (regexp-quote (symbol-name fun-or-var))
220 "\"")
221 (concat "DEFUN[ \t\n]*([ \t\n]*\""
222 (regexp-quote (subr-name fun-or-var))
223 "\""))
224 nil t)
225 (error "Can't find source for %s" fun-or-var))
226 (cons (current-buffer) (match-beginning 0))))
228 ;;;###autoload
229 (defun find-library (library)
230 "Find the Emacs Lisp source of LIBRARY.
231 LIBRARY should be a string (the name of the library)."
232 (interactive
233 (let* ((dirs (or find-function-source-path load-path))
234 (suffixes (find-library-suffixes))
235 (table (apply-partially 'locate-file-completion-table
236 dirs suffixes))
237 (def (if (eq (function-called-at-point) 'require)
238 ;; `function-called-at-point' may return 'require
239 ;; with `point' anywhere on this line. So wrap the
240 ;; `save-excursion' below in a `condition-case' to
241 ;; avoid reporting a scan-error here.
242 (condition-case nil
243 (save-excursion
244 (backward-up-list)
245 (forward-char)
246 (forward-sexp 2)
247 (thing-at-point 'symbol))
248 (error nil))
249 (thing-at-point 'symbol))))
250 (when (and def (not (test-completion def table)))
251 (setq def nil))
252 (list
253 (completing-read (if def (format "Library name (default %s): " def)
254 "Library name: ")
255 table nil nil nil nil def))))
256 (let ((buf (find-file-noselect (find-library-name library))))
257 (condition-case nil (switch-to-buffer buf) (error (pop-to-buffer buf)))))
259 ;;;###autoload
260 (defun find-function-search-for-symbol (symbol type library)
261 "Search for SYMBOL's definition of type TYPE in LIBRARY.
262 Visit the library in a buffer, and return a cons cell (BUFFER . POSITION),
263 or just (BUFFER . nil) if the definition can't be found in the file.
265 If TYPE is nil, look for a function definition.
266 Otherwise, TYPE specifies the kind of definition,
267 and it is interpreted via `find-function-regexp-alist'.
268 The search is done in the source for library LIBRARY."
269 (if (null library)
270 (error "Don't know where `%s' is defined" symbol))
271 ;; Some functions are defined as part of the construct
272 ;; that defines something else.
273 (while (and (symbolp symbol) (get symbol 'definition-name))
274 (setq symbol (get symbol 'definition-name)))
275 (if (string-match "\\`src/\\(.*\\.\\(c\\|m\\)\\)\\'" library)
276 (find-function-C-source symbol (match-string 1 library) type)
277 (when (string-match "\\.el\\(c\\)\\'" library)
278 (setq library (substring library 0 (match-beginning 1))))
279 ;; Strip extension from .emacs.el to make sure symbol is searched in
280 ;; .emacs too.
281 (when (string-match "\\.emacs\\(.el\\)" library)
282 (setq library (substring library 0 (match-beginning 1))))
283 (let* ((filename (find-library-name library))
284 (regexp-symbol (cdr (assq type find-function-regexp-alist))))
285 (with-current-buffer (find-file-noselect filename)
286 (let ((regexp (format (symbol-value regexp-symbol)
287 ;; Entry for ` (backquote) macro in loaddefs.el,
288 ;; (defalias (quote \`)..., has a \ but
289 ;; (symbol-name symbol) doesn't. Add an
290 ;; optional \ to catch this.
291 (concat "\\\\?"
292 (regexp-quote (symbol-name symbol)))))
293 (case-fold-search))
294 (with-syntax-table emacs-lisp-mode-syntax-table
295 (goto-char (point-min))
296 (if (or (re-search-forward regexp nil t)
297 ;; `regexp' matches definitions using known forms like
298 ;; `defun', or `defvar'. But some functions/variables
299 ;; are defined using special macros (or functions), so
300 ;; if `regexp' can't find the definition, we look for
301 ;; something of the form "(SOMETHING <symbol> ...)".
302 ;; This fails to distinguish function definitions from
303 ;; variable declarations (or even uses thereof), but is
304 ;; a good pragmatic fallback.
305 (re-search-forward
306 (concat "^([^ ]+" find-function-space-re "['(]?"
307 (regexp-quote (symbol-name symbol))
308 "\\_>")
309 nil t))
310 (progn
311 (beginning-of-line)
312 (cons (current-buffer) (point)))
313 (cons (current-buffer) nil))))))))
315 ;;;###autoload
316 (defun find-function-noselect (function &optional lisp-only)
317 "Return a pair (BUFFER . POINT) pointing to the definition of FUNCTION.
319 Finds the source file containing the definition of FUNCTION
320 in a buffer and the point of the definition. The buffer is
321 not selected. If the function definition can't be found in
322 the buffer, returns (BUFFER).
324 If FUNCTION is a built-in function, this function normally
325 attempts to find it in the Emacs C sources; however, if LISP-ONLY
326 is non-nil, signal an error instead.
328 If the file where FUNCTION is defined is not known, then it is
329 searched for in `find-function-source-path' if non-nil, otherwise
330 in `load-path'."
331 (if (not function)
332 (error "You didn't specify a function"))
333 (let ((def (symbol-function (find-function-advised-original function)))
334 aliases)
335 ;; FIXME for completeness, it might be nice to print something like:
336 ;; foo (which is advised), which is an alias for bar (which is advised).
337 (while (symbolp def)
338 (or (eq def function)
339 (if aliases
340 (setq aliases (concat aliases
341 (format ", which is an alias for `%s'"
342 (symbol-name def))))
343 (setq aliases (format "`%s' is an alias for `%s'"
344 function (symbol-name def)))))
345 (setq function (symbol-function (find-function-advised-original function))
346 def (symbol-function (find-function-advised-original function))))
347 (if aliases
348 (message "%s" aliases))
349 (let ((library
350 (cond ((autoloadp def) (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))))
358 (defun find-function-read (&optional type)
359 "Read and return an interned symbol, defaulting to the one near point.
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* ((symb1 (cond ((null type) (function-called-at-point))
366 ((eq type 'defvar) (variable-at-point))
367 (t (variable-at-point t))))
368 (symb (unless (eq symb1 0) symb1))
369 (predicate (cdr (assq type '((nil . fboundp)
370 (defvar . boundp)
371 (defface . facep)))))
372 (prompt-type (cdr (assq type '((nil . "function")
373 (defvar . "variable")
374 (defface . "face")))))
375 (prompt (concat "Find " prompt-type
376 (and symb (format " (default %s)" symb))
377 ": "))
378 (enable-recursive-minibuffers t))
379 (list (intern (completing-read
380 prompt obarray predicate
381 t nil nil (and symb (symbol-name symb)))))))
383 (defun find-function-do-it (symbol type switch-fn)
384 "Find Emacs Lisp SYMBOL in a buffer and display it.
385 TYPE is nil to search for a function definition,
386 or else `defvar' or `defface'.
388 The variable `find-function-recenter-line' controls how
389 to recenter the display. SWITCH-FN is the function to call
390 to display and select the buffer.
391 See also `find-function-after-hook'.
393 Set mark before moving, if the buffer already existed."
394 (let* ((orig-point (point))
395 (orig-buf (window-buffer))
396 (orig-buffers (buffer-list))
397 (buffer-point (save-excursion
398 (find-definition-noselect symbol type)))
399 (new-buf (car buffer-point))
400 (new-point (cdr buffer-point)))
401 (when buffer-point
402 (when (memq new-buf orig-buffers)
403 (push-mark orig-point))
404 (funcall switch-fn new-buf)
405 (when new-point (goto-char new-point))
406 (recenter find-function-recenter-line)
407 (run-hooks 'find-function-after-hook))))
409 ;;;###autoload
410 (defun find-function (function)
411 "Find the definition of the FUNCTION near point.
413 Finds the source file containing the definition of the function
414 near point (selected by `function-called-at-point') in a buffer and
415 places point before the definition.
416 Set mark before moving, if the buffer already existed.
418 The library where FUNCTION is defined is searched for in
419 `find-function-source-path', if non-nil, otherwise in `load-path'.
420 See also `find-function-recenter-line' and `find-function-after-hook'."
421 (interactive (find-function-read))
422 (find-function-do-it function nil 'switch-to-buffer))
424 ;;;###autoload
425 (defun find-function-other-window (function)
426 "Find, in another window, the definition of FUNCTION near point.
428 See `find-function' for more details."
429 (interactive (find-function-read))
430 (find-function-do-it function nil 'switch-to-buffer-other-window))
432 ;;;###autoload
433 (defun find-function-other-frame (function)
434 "Find, in another frame, the definition of FUNCTION near point.
436 See `find-function' for more details."
437 (interactive (find-function-read))
438 (find-function-do-it function nil 'switch-to-buffer-other-frame))
440 ;;;###autoload
441 (defun find-variable-noselect (variable &optional file)
442 "Return a pair `(BUFFER . POINT)' pointing to the definition of VARIABLE.
444 Finds the library containing the definition of VARIABLE in a buffer and
445 the point of the definition. The buffer is not selected.
446 If the variable's definition can't be found in the buffer, return (BUFFER).
448 The library where VARIABLE is defined is searched for in FILE or
449 `find-function-source-path', if non-nil, otherwise in `load-path'."
450 (if (not variable)
451 (error "You didn't specify a variable")
452 (let ((library (or file
453 (symbol-file variable 'defvar)
454 (help-C-file-name variable 'var))))
455 (find-function-search-for-symbol variable 'defvar library))))
457 ;;;###autoload
458 (defun find-variable (variable)
459 "Find the definition of the VARIABLE at or before point.
461 Finds the library containing the definition of the variable
462 near point (selected by `variable-at-point') in a buffer and
463 places point before the definition.
465 Set mark before moving, if the buffer already existed.
467 The library where VARIABLE is defined is searched for in
468 `find-function-source-path', if non-nil, otherwise in `load-path'.
469 See also `find-function-recenter-line' and `find-function-after-hook'."
470 (interactive (find-function-read 'defvar))
471 (find-function-do-it variable 'defvar 'switch-to-buffer))
473 ;;;###autoload
474 (defun find-variable-other-window (variable)
475 "Find, in another window, the definition of VARIABLE near point.
477 See `find-variable' for more details."
478 (interactive (find-function-read 'defvar))
479 (find-function-do-it variable 'defvar 'switch-to-buffer-other-window))
481 ;;;###autoload
482 (defun find-variable-other-frame (variable)
483 "Find, in another frame, the definition of VARIABLE near point.
485 See `find-variable' for more details."
486 (interactive (find-function-read 'defvar))
487 (find-function-do-it variable 'defvar 'switch-to-buffer-other-frame))
489 ;;;###autoload
490 (defun find-definition-noselect (symbol type &optional file)
491 "Return a pair `(BUFFER . POINT)' pointing to the definition of SYMBOL.
492 If the definition can't be found in the buffer, return (BUFFER).
493 TYPE says what type of definition: nil for a function, `defvar' for a
494 variable, `defface' for a face. This function does not switch to the
495 buffer nor display it.
497 The library where SYMBOL is defined is searched for in FILE or
498 `find-function-source-path', if non-nil, otherwise in `load-path'."
499 (cond
500 ((not symbol)
501 (error "You didn't specify a symbol"))
502 ((null type)
503 (find-function-noselect symbol))
504 ((eq type 'defvar)
505 (find-variable-noselect symbol file))
507 (let ((library (or file (symbol-file symbol type))))
508 (find-function-search-for-symbol symbol type library)))))
510 ;; For symmetry, this should be called find-face; but some programs
511 ;; assume that, if that name is defined, it means something else.
512 ;;;###autoload
513 (defun find-face-definition (face)
514 "Find the definition of FACE. FACE defaults to the name near point.
516 Finds the Emacs Lisp library containing the definition of the face
517 near point (selected by `variable-at-point') in a buffer and
518 places point before the definition.
520 Set mark before moving, if the buffer already existed.
522 The library where FACE is defined is searched for in
523 `find-function-source-path', if non-nil, otherwise in `load-path'.
524 See also `find-function-recenter-line' and `find-function-after-hook'."
525 (interactive (find-function-read 'defface))
526 (find-function-do-it face 'defface 'switch-to-buffer))
528 ;;;###autoload
529 (defun find-function-on-key (key)
530 "Find the function that KEY invokes. KEY is a string.
531 Set mark before moving, if the buffer already existed."
532 (interactive "kFind function on key: ")
533 (let (defn)
534 (save-excursion
535 (let* ((event (and (eventp key) (aref key 0))) ; Null event OK below.
536 (start (event-start event))
537 (modifiers (event-modifiers event))
538 (window (and (or (memq 'click modifiers) (memq 'down modifiers)
539 (memq 'drag modifiers))
540 (posn-window start))))
541 ;; For a mouse button event, go to the button it applies to
542 ;; to get the right key bindings. And go to the right place
543 ;; in case the keymap depends on where you clicked.
544 (when (windowp window)
545 (set-buffer (window-buffer window))
546 (goto-char (posn-point start)))
547 (setq defn (key-binding key))))
548 (let ((key-desc (key-description key)))
549 (if (or (null defn) (integerp defn))
550 (message "%s is unbound" key-desc)
551 (if (consp defn)
552 (message "%s runs %s" key-desc (prin1-to-string defn))
553 (find-function-other-window defn))))))
555 ;;;###autoload
556 (defun find-function-at-point ()
557 "Find directly the function at point in the other window."
558 (interactive)
559 (let ((symb (function-called-at-point)))
560 (when symb
561 (find-function-other-window symb))))
563 ;;;###autoload
564 (defun find-variable-at-point ()
565 "Find directly the variable at point in the other window."
566 (interactive)
567 (let ((symb (variable-at-point)))
568 (when (and symb (not (equal symb 0)))
569 (find-variable-other-window symb))))
571 ;;;###autoload
572 (defun find-function-setup-keys ()
573 "Define some key bindings for the find-function family of functions."
574 (define-key ctl-x-map "F" 'find-function)
575 (define-key ctl-x-4-map "F" 'find-function-other-window)
576 (define-key ctl-x-5-map "F" 'find-function-other-frame)
577 (define-key ctl-x-map "K" 'find-function-on-key)
578 (define-key ctl-x-map "V" 'find-variable)
579 (define-key ctl-x-4-map "V" 'find-variable-other-window)
580 (define-key ctl-x-5-map "V" 'find-variable-other-frame))
582 (provide 'find-func)
584 ;;; find-func.el ends here