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-name (library)
 145   "Return the absolute file name of the Emacs Lisp source of LIBRARY.
 146 LIBRARY should be a string (the name of the library)."
 147   ;; If the library is byte-compiled, try to find a source library by
 148   ;; the same name.
 149   (if (string-match "\\.el\\(c\\(\\..*\\)?\\)\\'" library)
 150       (setq library (replace-match "" t t library)))
 151   (or
 152    (locate-file library
 153                 (or find-function-source-path load-path)
 154                 (find-library-suffixes))
 155    (locate-file library
 156                 (or find-function-source-path load-path)
 157                 load-file-rep-suffixes)
 158    (error "Can't find library %s" library)))
 159
 160 (defvar find-function-C-source-directory
 161   (let ((dir (expand-file-name "src" source-directory)))
 162     (when (and (file-directory-p dir) (file-readable-p dir))
 163       dir))
 164   "Directory where the C source files of Emacs can be found.
 165 If nil, do not try to find the source code of functions and variables
 166 defined in C.")
 167
 168 (declare-function ad-get-advice-info "advice" (function))
 169
 170 (defun find-function-advised-original (func)
 171   "Return the original function symbol of an advised function FUNC.
 172 If FUNC is not the symbol of an advised function, just returns FUNC."
 173   (or (and (symbolp func)
 174            (featurep 'advice)
 175            (let ((ofunc (cdr (assq 'origname (ad-get-advice-info func)))))
 176              (and (fboundp ofunc) ofunc)))
 177       func))
 178
 179 (defun find-function-C-source (fun-or-var file type)
 180   "Find the source location where FUN-OR-VAR is defined in FILE.
 181 TYPE should be nil to find a function, or `defvar' to find a variable."
 182   (unless find-function-C-source-directory
 183     (setq find-function-C-source-directory
 184           (read-directory-name "Emacs C source dir: " nil nil t)))
 185   (setq file (expand-file-name file find-function-C-source-directory))
 186   (unless (file-readable-p file)
 187     (error "The C source file %s is not available"
 188            (file-name-nondirectory file)))
 189   (unless type
 190     ;; Either or both an alias and its target might be advised.
 191     (setq fun-or-var (find-function-advised-original
 192                       (indirect-function
 193                        (find-function-advised-original fun-or-var)))))
 194   (with-current-buffer (find-file-noselect file)
 195     (goto-char (point-min))
 196     (unless (re-search-forward
 197              (if type
 198                  (concat "DEFVAR[A-Z_]*[ \t\n]*([ \t\n]*\""
 199                          (regexp-quote (symbol-name fun-or-var))
 200                          "\"")
 201                (concat "DEFUN[ \t\n]*([ \t\n]*\""
 202                        (regexp-quote (subr-name fun-or-var))
 203                        "\""))
 204              nil t)
 205       (error "Can't find source for %s" fun-or-var))
 206     (cons (current-buffer) (match-beginning 0))))
 207
 208 ;;;###autoload
 209 (defun find-library (library)
 210   "Find the Emacs Lisp source of LIBRARY.
 211 LIBRARY should be a string (the name of the library)."
 212   (interactive
 213    (let* ((dirs (or find-function-source-path load-path))
 214           (suffixes (find-library-suffixes))
 215           (table (apply-partially 'locate-file-completion-table
 216                                   dirs suffixes))
 217           (def (if (eq (function-called-at-point) 'require)
 218                    ;; `function-called-at-point' may return 'require
 219                    ;; with `point' anywhere on this line.  So wrap the
 220                    ;; `save-excursion' below in a `condition-case' to
 221                    ;; avoid reporting a scan-error here.
 222                    (condition-case nil
 223                        (save-excursion
 224                          (backward-up-list)
 225                          (forward-char)
 226                          (forward-sexp 2)
 227                          (thing-at-point 'symbol))
 228                      (error nil))
 229                  (thing-at-point 'symbol))))
 230      (when (and def (not (test-completion def table)))
 231        (setq def nil))
 232      (list
 233       (completing-read (if def (format "Library name (default %s): " def)
 234                          "Library name: ")
 235                        table nil nil nil nil def))))
 236   (let ((buf (find-file-noselect (find-library-name library))))
 237     (condition-case nil (switch-to-buffer buf) (error (pop-to-buffer buf)))))
 238
 239 ;;;###autoload
 240 (defun find-function-search-for-symbol (symbol type library)
 241   "Search for SYMBOL's definition of type TYPE in LIBRARY.
 242 Visit the library in a buffer, and return a cons cell (BUFFER . POSITION),
 243 or just (BUFFER . nil) if the definition can't be found in the file.
 244
 245 If TYPE is nil, look for a function definition.
 246 Otherwise, TYPE specifies the kind of definition,
 247 and it is interpreted via `find-function-regexp-alist'.
 248 The search is done in the source for library LIBRARY."
 249   (if (null library)
 250       (error "Don't know where `%s' is defined" symbol))
 251   ;; Some functions are defined as part of the construct
 252   ;; that defines something else.
 253   (while (and (symbolp symbol) (get symbol 'definition-name))
 254     (setq symbol (get symbol 'definition-name)))
 255   (if (string-match "\\`src/\\(.*\\.\\(c\\|m\\)\\)\\'" library)
 256       (find-function-C-source symbol (match-string 1 library) type)
 257     (when (string-match "\\.el\\(c\\)\\'" library)
 258       (setq library (substring library 0 (match-beginning 1))))
 259     ;; Strip extension from .emacs.el to make sure symbol is searched in
 260     ;; .emacs too.
 261     (when (string-match "\\.emacs\\(.el\\)" library)
 262       (setq library (substring library 0 (match-beginning 1))))
 263     (let* ((filename (find-library-name library))
 264            (regexp-symbol (cdr (assq type find-function-regexp-alist))))
 265       (with-current-buffer (find-file-noselect filename)
 266         (let ((regexp (format (symbol-value regexp-symbol)
 267                               ;; Entry for ` (backquote) macro in loaddefs.el,
 268                               ;; (defalias (quote \`)..., has a \ but
 269                               ;; (symbol-name symbol) doesn't.  Add an
 270                               ;; optional \ to catch this.
 271                               (concat "\\\\?"
 272                                       (regexp-quote (symbol-name symbol)))))
 273               (case-fold-search))
 274           (with-syntax-table emacs-lisp-mode-syntax-table
 275             (goto-char (point-min))
 276             (if (or (re-search-forward regexp nil t)
 277                     ;; `regexp' matches definitions using known forms like
 278                     ;; `defun', or `defvar'.  But some functions/variables
 279                     ;; are defined using special macros (or functions), so
 280                     ;; if `regexp' can't find the definition, we look for
 281                     ;; something of the form "(SOMETHING <symbol> ...)".
 282                     ;; This fails to distinguish function definitions from
 283                     ;; variable declarations (or even uses thereof), but is
 284                     ;; a good pragmatic fallback.
 285                     (re-search-forward
 286                      (concat "^([^ ]+" find-function-space-re "['(]?"
 287                              (regexp-quote (symbol-name symbol))
 288                              "\\_>")
 289                      nil t))
 290                 (progn
 291                   (beginning-of-line)
 292                   (cons (current-buffer) (point)))
 293               (cons (current-buffer) nil))))))))
 294
 295 ;;;###autoload
 296 (defun find-function-noselect (function)
 297   "Return a pair (BUFFER . POINT) pointing to the definition of FUNCTION.
 298
 299 Finds the source file containing the definition of FUNCTION
 300 in a buffer and the point of the definition.  The buffer is
 301 not selected.  If the function definition can't be found in
 302 the buffer, returns (BUFFER).
 303
 304 If the file where FUNCTION is defined is not known, then it is
 305 searched for in `find-function-source-path' if non-nil, otherwise
 306 in `load-path'."
 307   (if (not function)
 308     (error "You didn't specify a function"))
 309   (let ((def (symbol-function (find-function-advised-original function)))
 310         aliases)
 311     ;; FIXME for completeness, it might be nice to print something like:
 312     ;; foo (which is advised), which is an alias for bar (which is advised).
 313     (while (symbolp def)
 314       (or (eq def function)
 315           (if aliases
 316               (setq aliases (concat aliases
 317                                     (format ", which is an alias for `%s'"
 318                                             (symbol-name def))))
 319             (setq aliases (format "`%s' is an alias for `%s'"
 320                                   function (symbol-name def)))))
 321       (setq function (symbol-function (find-function-advised-original function))
 322             def (symbol-function (find-function-advised-original function))))
 323     (if aliases
 324         (message "%s" aliases))
 325     (let ((library
 326            (cond ((eq (car-safe def) 'autoload)
 327                   (nth 1 def))
 328                  ((subrp def)
 329                   (help-C-file-name def 'subr))
 330                  ((symbol-file function 'defun)))))
 331       (find-function-search-for-symbol function nil library))))
 332
 333 (defun find-function-read (&optional type)
 334   "Read and return an interned symbol, defaulting to the one near point.
 335
 336 If TYPE is nil, insist on a symbol with a function definition.
 337 Otherwise TYPE should be `defvar' or `defface'.
 338 If TYPE is nil, defaults using `function-called-at-point',
 339 otherwise uses `variable-at-point'."
 340   (let ((symb (if (null type)
 341                   (function-called-at-point)
 342                 (if (eq type 'defvar)
 343                     (variable-at-point)
 344                   (variable-at-point t))))
 345         (predicate (cdr (assq type '((nil . fboundp) (defvar . boundp)
 346                                      (defface . facep)))))
 347         (prompt (cdr (assq type '((nil . "function") (defvar . "variable")
 348                                   (defface . "face")))))
 349         (enable-recursive-minibuffers t)
 350         val)
 351     (if (equal symb 0)
 352         (setq symb nil))
 353     (setq val (completing-read
 354                (concat "Find "
 355                        prompt
 356                        (if symb
 357                            (format " (default %s)" symb))
 358                        ": ")
 359                obarray predicate t nil))
 360     (list (if (equal val "")
 361               symb
 362             (intern val)))))
 363
 364 (defun find-function-do-it (symbol type switch-fn)
 365   "Find Emacs Lisp SYMBOL in a buffer and display it.
 366 TYPE is nil to search for a function definition,
 367 or else `defvar' or `defface'.
 368
 369 The variable `find-function-recenter-line' controls how
 370 to recenter the display.  SWITCH-FN is the function to call
 371 to display and select the buffer.
 372 See also `find-function-after-hook'.
 373
 374 Set mark before moving, if the buffer already existed."
 375   (let* ((orig-point (point))
 376         (orig-buf (window-buffer))
 377         (orig-buffers (buffer-list))
 378         (buffer-point (save-excursion
 379                         (find-definition-noselect symbol type)))
 380         (new-buf (car buffer-point))
 381         (new-point (cdr buffer-point)))
 382     (when buffer-point
 383       (when (memq new-buf orig-buffers)
 384         (push-mark orig-point))
 385       (funcall switch-fn new-buf)
 386       (when new-point (goto-char new-point))
 387       (recenter find-function-recenter-line)
 388       (run-hooks 'find-function-after-hook))))
 389
 390 ;;;###autoload
 391 (defun find-function (function)
 392   "Find the definition of the FUNCTION near point.
 393
 394 Finds the source file containing the definition of the function
 395 near point (selected by `function-called-at-point') in a buffer and
 396 places point before the definition.
 397 Set mark before moving, if the buffer already existed.
 398
 399 The library where FUNCTION is defined is searched for in
 400 `find-function-source-path', if non-nil, otherwise in `load-path'.
 401 See also `find-function-recenter-line' and `find-function-after-hook'."
 402   (interactive (find-function-read))
 403   (find-function-do-it function nil 'switch-to-buffer))
 404
 405 ;;;###autoload
 406 (defun find-function-other-window (function)
 407   "Find, in another window, the definition of FUNCTION near point.
 408
 409 See `find-function' for more details."
 410   (interactive (find-function-read))
 411   (find-function-do-it function nil 'switch-to-buffer-other-window))
 412
 413 ;;;###autoload
 414 (defun find-function-other-frame (function)
 415   "Find, in another frame, the definition of FUNCTION near point.
 416
 417 See `find-function' for more details."
 418   (interactive (find-function-read))
 419   (find-function-do-it function nil 'switch-to-buffer-other-frame))
 420
 421 ;;;###autoload
 422 (defun find-variable-noselect (variable &optional file)
 423   "Return a pair `(BUFFER . POINT)' pointing to the definition of VARIABLE.
 424
 425 Finds the library containing the definition of VARIABLE in a buffer and
 426 the point of the definition.  The buffer is not selected.
 427 If the variable's definition can't be found in the buffer, return (BUFFER).
 428
 429 The library where VARIABLE is defined is searched for in FILE or
 430 `find-function-source-path', if non-nil, otherwise in `load-path'."
 431   (if (not variable)
 432       (error "You didn't specify a variable")
 433     (let ((library (or file
 434                        (symbol-file variable 'defvar)
 435                        (help-C-file-name variable 'var))))
 436       (find-function-search-for-symbol variable 'defvar library))))
 437
 438 ;;;###autoload
 439 (defun find-variable (variable)
 440   "Find the definition of the VARIABLE at or before point.
 441
 442 Finds the library containing the definition of the variable
 443 near point (selected by `variable-at-point') in a buffer and
 444 places point before the definition.
 445
 446 Set mark before moving, if the buffer already existed.
 447
 448 The library where VARIABLE is defined is searched for in
 449 `find-function-source-path', if non-nil, otherwise in `load-path'.
 450 See also `find-function-recenter-line' and `find-function-after-hook'."
 451   (interactive (find-function-read 'defvar))
 452   (find-function-do-it variable 'defvar 'switch-to-buffer))
 453
 454 ;;;###autoload
 455 (defun find-variable-other-window (variable)
 456   "Find, in another window, the definition of VARIABLE near point.
 457
 458 See `find-variable' for more details."
 459   (interactive (find-function-read 'defvar))
 460   (find-function-do-it variable 'defvar 'switch-to-buffer-other-window))
 461
 462 ;;;###autoload
 463 (defun find-variable-other-frame (variable)
 464   "Find, in another frame, the definition of VARIABLE near point.
 465
 466 See `find-variable' for more details."
 467   (interactive (find-function-read 'defvar))
 468   (find-function-do-it variable 'defvar 'switch-to-buffer-other-frame))
 469
 470 ;;;###autoload
 471 (defun find-definition-noselect (symbol type &optional file)
 472   "Return a pair `(BUFFER . POINT)' pointing to the definition of SYMBOL.
 473 If the definition can't be found in the buffer, return (BUFFER).
 474 TYPE says what type of definition: nil for a function, `defvar' for a
 475 variable, `defface' for a face.  This function does not switch to the
 476 buffer nor display it.
 477
 478 The library where SYMBOL is defined is searched for in FILE or
 479 `find-function-source-path', if non-nil, otherwise in `load-path'."
 480   (cond
 481    ((not symbol)
 482     (error "You didn't specify a symbol"))
 483    ((null type)
 484     (find-function-noselect symbol))
 485    ((eq type 'defvar)
 486     (find-variable-noselect symbol file))
 487    (t
 488     (let ((library (or file (symbol-file symbol type))))
 489       (find-function-search-for-symbol symbol type library)))))
 490
 491 ;; For symmetry, this should be called find-face; but some programs
 492 ;; assume that, if that name is defined, it means something else.
 493 ;;;###autoload
 494 (defun find-face-definition (face)
 495   "Find the definition of FACE.  FACE defaults to the name near point.
 496
 497 Finds the Emacs Lisp library containing the definition of the face
 498 near point (selected by `variable-at-point') in a buffer and
 499 places point before the definition.
 500
 501 Set mark before moving, if the buffer already existed.
 502
 503 The library where FACE is defined is searched for in
 504 `find-function-source-path', if non-nil, otherwise in `load-path'.
 505 See also `find-function-recenter-line' and `find-function-after-hook'."
 506   (interactive (find-function-read 'defface))
 507   (find-function-do-it face 'defface 'switch-to-buffer))
 508
 509 ;;;###autoload
 510 (defun find-function-on-key (key)
 511   "Find the function that KEY invokes.  KEY is a string.
 512 Set mark before moving, if the buffer already existed."
 513   (interactive "kFind function on key: ")
 514   (let (defn)
 515     (save-excursion
 516       (let* ((event (and (eventp key) (aref key 0))) ; Null event OK below.
 517              (start (event-start event))
 518              (modifiers (event-modifiers event))
 519              (window (and (or (memq 'click modifiers) (memq 'down modifiers)
 520                               (memq 'drag modifiers))
 521                           (posn-window start))))
 522         ;; For a mouse button event, go to the button it applies to
 523         ;; to get the right key bindings.  And go to the right place
 524         ;; in case the keymap depends on where you clicked.
 525         (when (windowp window)
 526           (set-buffer (window-buffer window))
 527           (goto-char (posn-point start)))
 528         (setq defn (key-binding key))))
 529     (let ((key-desc (key-description key)))
 530       (if (or (null defn) (integerp defn))
 531           (message "%s is unbound" key-desc)
 532         (if (consp defn)
 533             (message "%s runs %s" key-desc (prin1-to-string defn))
 534           (find-function-other-window defn))))))
 535
 536 ;;;###autoload
 537 (defun find-function-at-point ()
 538   "Find directly the function at point in the other window."
 539   (interactive)
 540   (let ((symb (function-called-at-point)))
 541     (when symb
 542       (find-function-other-window symb))))
 543
 544 ;;;###autoload
 545 (defun find-variable-at-point ()
 546   "Find directly the variable at point in the other window."
 547   (interactive)
 548   (let ((symb (variable-at-point)))
 549     (when (and symb (not (equal symb 0)))
 550       (find-variable-other-window symb))))
 551
 552 ;;;###autoload
 553 (defun find-function-setup-keys ()
 554   "Define some key bindings for the find-function family of functions."
 555   (define-key ctl-x-map "F" 'find-function)
 556   (define-key ctl-x-4-map "F" 'find-function-other-window)
 557   (define-key ctl-x-5-map "F" 'find-function-other-frame)
 558   (define-key ctl-x-map "K" 'find-function-on-key)
 559   (define-key ctl-x-map "V" 'find-variable)
 560   (define-key ctl-x-4-map "V" 'find-variable-other-window)
 561   (define-key ctl-x-5-map "V" 'find-variable-other-frame))
 562
 563 (provide 'find-func)
 564
 565 ;;; find-func.el ends here