lisp/progmodes/etags.el

   1 ;; etags.el --- etags facility for Emacs
   2
   3 ;; Copyright (C) 1985, 1986, 1988, 1989, 1992 Free Software Foundation, Inc.
   4
   5 ;; Author: Roland McGrath <roland@gnu.ai.mit.edu>
   6 ;; Keywords: tools
   7
   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
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  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
  24 ;;; Code:
  25
  26 ;;;###autoload
  27 (defvar tags-file-name nil "\
  28 *File name of tags table.
  29 To switch to a new tags table, setting this variable is sufficient.
  30 Use the `etags' program to make a tags table file.")
  31 ;;;###autoload (put 'tags-file-name 'variable-interactive "fVisit tags table: ")
  32
  33 ;;;###autoload
  34 (defvar tags-table-list nil
  35   "*List of names of tags table files which are currently being searched.
  36 An element of nil means to look for a file \"TAGS\" in the current directory.
  37 Use `visit-tags-table-buffer' to cycle through tags tables in this list.")
  38
  39 (defvar tags-table-list-pointer nil
  40   "Pointer into `tags-table-list', or into a list of included tags tables,
  41 where the current state of searching is.  Use `visit-tags-table-buffer' to
  42 cycle through tags tables in this list.")
  43
  44 (defvar tags-table-parent-pointer-list nil
  45   "List of values to restore into `tags-table-list-pointer' when it hits nil.")
  46
  47 (defvar tags-table-set-list nil
  48   "List of sets of tags table which have been used together in the past.
  49 Each element is a list of strings which are file names.")
  50
  51 ;;;###autoload
  52 (defvar find-tag-hook nil
  53   "*Hook to be run by \\[find-tag] after finding a tag.  See `run-hooks'.
  54 The value in the buffer in which \\[find-tag] is done is used,
  55 not the value in the buffer \\[find-tag] goes to.")
  56
  57 ;;;###autoload
  58 (defvar find-tag-default-function nil
  59   "*If non-nil, a function of no arguments used by \\[find-tag] to pick a
  60 default tag.  If nil, and the symbol that is the value of `major-mode'
  61 has a `find-tag-default-function' property (see `put'), that is used.
  62 Otherwise, `find-tag-default' is used.")
  63
  64 ;;;###autoload
  65 (defvar default-tags-table-function nil
  66   "*If non-nil, a function of no arguments to choose a default tags file
  67 for a particular buffer.")
  68 \f
  69 ;; Tags table state.
  70 ;; These variables are local in tags table buffers.
  71
  72 (defvar tag-lines-already-matched nil
  73   "List of positions of beginnings of lines within the tags table
  74 that are already matched.")
  75
  76 (defvar tags-table-files nil
  77   "List of file names covered by current tags table.
  78 nil means it has not yet been computed; use `tags-table-files' to do so.")
  79
  80 (defvar tags-completion-table nil
  81   "Alist of tag names defined in current tags table.")
  82
  83 (defvar tags-included-tables nil
  84   "List of tags tables included by the current tags table.")
  85
  86 (defvar next-file-list nil
  87   "List of files for \\[next-file] to process.")
  88 \f
  89 ;; Hooks for file formats.
  90
  91 (defvar tags-table-format-hooks '(etags-recognize-tags-table
  92                                   recognize-empty-tags-table)
  93   "List of functions to be called in a tags table buffer to identify
  94 the type of tags table.  The functions are called in order, with no arguments,
  95 until one returns non-nil.  The function should make buffer-local bindings
  96 of the format-parsing tags function variables if successful.")
  97
  98 (defvar file-of-tag-function nil
  99   "Function to do the work of `file-of-tag' (which see).")
 100 (defvar tags-table-files-function nil
 101   "Function to do the work of `tags-table-files' (which see).")
 102 (defvar tags-completion-table-function nil
 103   "Function to build the tags-completion-table.")
 104 (defvar snarf-tag-function nil
 105   "Function to get info about a matched tag for `goto-tag-location-function'.")
 106 (defvar goto-tag-location-function nil
 107   "Function of to go to the location in the buffer specified by a tag.
 108 One argument, the tag info returned by `snarf-tag-function'.")
 109 (defvar find-tag-regexp-search-function nil
 110   "Search function passed to `find-tag-in-order' for finding a regexp tag.")
 111 (defvar find-tag-regexp-tag-order nil
 112   "Tag order passed to `find-tag-in-order' for finding a regexp tag.")
 113 (defvar find-tag-regexp-next-line-after-failure-p nil
 114   "Flag passed to `find-tag-in-order' for finding a regexp tag.")
 115 (defvar find-tag-search-function nil
 116   "Search function passed to `find-tag-in-order' for finding a tag.")
 117 (defvar find-tag-tag-order nil
 118   "Tag order passed to `find-tag-in-order' for finding a tag.")
 119 (defvar find-tag-next-line-after-failure-p nil
 120   "Flag passed to `find-tag-in-order' for finding a tag.")
 121 (defvar list-tags-function nil
 122   "Function to do the work of `list-tags' (which see).")
 123 (defvar tags-apropos-function nil
 124   "Function to do the work of `tags-apropos' (which see).")
 125 (defvar tags-included-tables-function nil
 126   "Function to do the work of `tags-included-tables' (which see).")
 127 (defvar verify-tags-table-function nil
 128   "Function to return t iff the current buffer vontains a valid
 129 \(already initialized\) tags file.")
 130 \f
 131 (defun initialize-new-tags-table ()
 132   "Initialize the tags table in the current buffer.
 133 Returns non-nil iff it is a valid tags table."
 134   (make-local-variable 'tag-lines-already-matched)
 135   (make-local-variable 'tags-table-files)
 136   (make-local-variable 'tags-completion-table)
 137   (make-local-variable 'tags-included-tables)
 138   (setq tags-table-files nil
 139         tag-lines-already-matched nil
 140         tags-completion-table nil
 141         tags-included-tables nil)
 142   ;; Value is t if we have found a valid tags table buffer.
 143   (let ((hooks tags-table-format-hooks))
 144     (while (and hooks
 145                 (not (funcall (car hooks))))
 146       (setq hooks (cdr hooks)))
 147     hooks))
 148
 149 ;;;###autoload
 150 (defun visit-tags-table (file &optional local)
 151   "Tell tags commands to use tags table file FILE.
 152 FILE should be the name of a file created with the `etags' program.
 153 A directory name is ok too; it means file TAGS in that directory.
 154
 155 Normally \\[visit-tags-table] sets the global value of `tags-file-name'.
 156 With a prefix arg, set the buffer-local value instead.
 157 When you find a tag with \\[find-tag], the buffer it finds the tag
 158 in is given a local value of this variable which is the name of the tags
 159 file the tag was in."
 160   (interactive (list (read-file-name "Visit tags table: (default TAGS) "
 161                                      default-directory
 162                                      (expand-file-name "TAGS"
 163                                                        default-directory)
 164                                      t)
 165                      current-prefix-arg))
 166   (let ((tags-file-name file))
 167     (save-excursion
 168       (or (visit-tags-file t)
 169           (signal 'file-error (list "Visiting tags table"
 170                                     "file does not exist"
 171                                     file)))
 172       (setq file tags-file-name)))
 173   (if local
 174       (setq tags-file-name file)
 175     (kill-local-variable 'tags-file-name)
 176     (setq-default tags-file-name file)))
 177
 178 ;; Move tags-table-list-pointer along and set tags-file-name.
 179 ;; Returns nil when out of tables.
 180 (defun tags-next-table ()
 181   (if (tags-included-tables)
 182       (progn
 183         ;; Move into the included tags tables.
 184         (if tags-table-list-pointer
 185             (setq tags-table-parent-pointer-list
 186                   (cons tags-table-list-pointer
 187                         tags-table-parent-pointer-list)))
 188         (setq tags-table-list-pointer tags-included-tables))
 189
 190     (if tags-table-list-pointer
 191         ;; Go to the next table in the list.
 192         (setq tags-table-list-pointer
 193               (cdr tags-table-list-pointer))
 194
 195       ;; Pop back to the tags table which includes this one.
 196       (setq tags-table-list-pointer
 197             (car tags-table-parent-pointer-list)
 198             tags-table-parent-pointer-list
 199             (cdr tags-table-parent-pointer-list))))
 200
 201   (and tags-table-list-pointer
 202       (setq tags-file-name
 203             (or (car tags-table-list-pointer)
 204                 ;; nil means look for TAGS in current directory.
 205                 (expand-file-name "TAGS" default-directory)))))
 206
 207 (defun visit-tags-table-buffer (&optional cont)
 208   "Select the buffer containing the current tags table.
 209 If optional arg is t, visit the next table in `tags-table-list'.
 210 If optional arg is the atom `reset', reset to the head of `tags-table-list'.
 211 If optional arg is the atom `same', don't look for a new table;
 212  just select the buffer.
 213 If arg is nil or absent, choose a buffer from information in
 214 `tags-file-name', `tags-table-list', `tags-table-list-pointer'.
 215 Returns t if it visits a tags table, or nil if there are no more in the list."
 216   (cond ((eq cont 'same)
 217          (let ((tags-file-name (car tags-table-list-pointer)))
 218            (and tags-file-name
 219                 (visit-tags-file nil)))
 220
 221          (cont
 222           (if (eq cont 'reset)
 223               (setq tags-table-list-pointer tags-table-list)
 224             (tags-next-table))
 225
 226           (while (and (not (visit-tags-file nil)) ;Skip over nonexistent files.
 227                       (tags-next-table)))
 228           (not (null tags-table-list-pointer)))
 229
 230          (t
 231           (setq tags-file-name
 232                 (or (cdr (assq 'tags-file-name (buffer-local-variables)))
 233                     (and default-tags-table-function
 234                          (funcall default-tags-table-function))
 235                     ;; Look for a tags table that contains
 236                     ;; tags for the current buffer's file.
 237                     (let ((tables tags-table-list)
 238                           (this-file (buffer-file-name))
 239                           (found nil))
 240                       (save-excursion
 241                         (while tables
 242                           (let ((tags-file-name (car tables)))
 243                             (if (and (file-exists-p tags-file-name)
 244                                      (progn
 245                                        (visit-tags-file nil)
 246                                        (or tags-table-files
 247                                            (setq tags-table-files
 248                                                  (funcall
 249                                                   tags-table-files-function)))
 250                                        (assoc this-file tags-file-files)))
 251                                 (setq found (car tables)
 252                                       tables nil)
 253                               (setq tables (cdr tables))))))
 254                       found)
 255                     (car tags-table-list-pointer)
 256                     tags-file-name
 257                     (expand-file-name
 258                      (read-file-name "Visit tags table: (default TAGS) "
 259                                      default-directory
 260                                      (expand-file-name "TAGS"
 261                                                        default-directory)
 262                                      t))))
 263           (visit-tags-file t)))))
 264
 265 ;; Visit tags-file-name and check that it's a valid tags table.  Returns
 266 ;; nil and does nothing if tags-file-name does not exist.  Otherwise, on
 267 ;; return tags-table-list and tags-table-list-pointer point to
 268 ;; tags-file-name.
 269 (defun visit-tags-file (put-in-list)
 270   (let ((file tags-file-name))
 271     (if (file-directory-p file)
 272         (setq file (expand-file-name "TAGS" file)))
 273     (if (or (get-file-buffer file)
 274             (file-exists-p file))
 275         (if (if (get-file-buffer file)
 276                 (let (win)
 277                   (set-buffer (get-file-buffer file))
 278                   (setq win (or verify-tags-table-function
 279                                 (initialize-new-tags-table)))
 280                   (if (or (verify-visited-file-modtime (current-buffer))
 281                           (not (yes-or-no-p
 282                                 "Tags file has changed, read new contents? ")))
 283                       (and win (funcall verify-tags-table-function))
 284                     (revert-buffer t t)
 285                     (initialize-new-tags-table)))
 286               (set-buffer (find-file-noselect file))
 287               (or (string= file buffer-file-name)
 288                   ;; find-file-noselect has changed the file name.
 289                   ;; Propagate change to tags-file-name and tags-table-list.
 290                   (let ((tail (assoc file tags-table-list)))
 291                     (if tail
 292                         (setcar tail buffer-file-name))
 293                     (setq tags-file-name buffer-file-name)))
 294               (initialize-new-tags-table))
 295
 296             (if (and put-in-list
 297                      (not (equal file (car tags-table-list-pointer))))
 298                 (let (elt)
 299                   ;; Bury the tags table buffer so it
 300                   ;; doesn't get in the user's way.
 301                   (bury-buffer (current-buffer))
 302                   ;; Look for this file in the current list of tags files.
 303                   (if (setq elt (member file tags-table-list))
 304                       (if (eq elt tags-table-list)
 305                           ;; Already at the head of the list.
 306                           ()
 307                         ;; Rotate this element to the head of the search list.
 308                         (setq tags-table-list-pointer
 309                               (nconc elt tags-table-list))
 310                         (while (not (eq (cdr tags-table-list) elt))
 311                           (setq tags-table-list (cdr tags-table-list)))
 312                         (setcdr tags-table-list nil)
 313                         (setq tags-table-list tags-table-list-pointer))
 314                     ;; The table is not in the current set.
 315                     ;; Try to find it in another previously used set.
 316                     (let ((sets tags-table-set-list))
 317                       (while (and sets
 318                                   (not (setq elt (member file
 319                                                          (car sets)))))
 320                         (setq sets (cdr sets)))
 321                       (if sets
 322                           (progn
 323                             ;; Found in some other set.  Switch to that
 324                             ;; set, making the selected tags table the head
 325                             ;; of the search list.
 326                             (or (memq tags-table-list tags-table-set-list)
 327                                 ;; Save the current list.
 328                                 (setq tags-table-set-list
 329                                       (cons tags-table-list
 330                                             tags-table-set-list)))
 331                             (setq tags-table-list (car sets))
 332                             (if (eq elt tags-table-list)
 333                                 ;; Already at the head of the list
 334                                 ()
 335                               ;; Rotate this element to the head of the list.
 336                               (setq tags-table-list-pointer
 337                                     (nconc elt tags-table-list))
 338                               (while (not (eq (cdr tags-table-list) elt))
 339                                 (setq tags-table-list (cdr tags-table-list)))
 340                               (setcdr tags-table-list nil)
 341                               (setq tags-table-list tags-table-list-pointer)
 342                               (setcar sets tags-table-list)))
 343                         ;; Not found in any current set.
 344                         (if (and tags-table-list
 345                                  (y-or-n-p
 346                                   (concat "Add " file " to current list"
 347                                           " of tags tables? ")))
 348                             ;; Add it to the current list.
 349                             (setq tags-table-list
 350                                   (cons file tags-table-list))
 351                           ;; Make a fresh list, and store the old one.
 352                           (or (memq tags-table-list tags-table-set-list)
 353                               (setq tags-table-set-list
 354                                     (cons tags-table-list
 355                                           tags-table-set-list)))
 356                           (setq tags-table-list (cons file nil)))
 357                         (setq tags-table-list-pointer tags-table-list))))
 358                   t)
 359               t)
 360
 361           ;; The buffer was not valid.  Don't use it again.
 362           (kill-local-variable 'tags-file-name)
 363           (setq tags-file-name nil)
 364           (error "File %s is not a valid tags table" buffer-file-name)))))
 365
 366 (defun file-of-tag ()
 367   "Return the file name of the file whose tags point is within.
 368 Assumes the tags table is the current buffer.
 369 File name returned is relative to tags table file's directory."
 370   (funcall file-of-tag-function))
 371
 372 ;;;###autoload
 373 (defun tags-table-files ()
 374   "Return a list of files in the current tags table.
 375 File names returned are absolute."
 376   (save-excursion
 377     (visit-tags-table-buffer)
 378     (or tags-table-files
 379         (setq tags-table-files
 380               (funcall tags-table-files-function)))))
 381
 382 (defun tags-included-tables ()
 383   "Return a list of tags tables included by the current table."
 384   (or tags-included-tables
 385       (setq tags-included-tables (funcall tags-included-tables-function))))
 386 \f
 387 ;; Build tags-completion-table on demand.  The single current tags table
 388 ;; and its included tags tables (and their included tables, etc.) have
 389 ;; their tags included in the completion table.
 390 (defun tags-completion-table ()
 391   (or tags-completion-table
 392       (condition-case ()
 393           (prog2
 394            (message "Making tags completion table for %s..." buffer-file-name)
 395            (let ((included (tags-included-tables))
 396                  (table (funcall tags-completion-table-function)))
 397              (save-excursion
 398                (while included
 399                  (let ((tags-file-name (car included)))
 400                    (visit-tags-file nil))
 401                  (if (tags-completion-table)
 402                      (mapatoms (function
 403                                 (lambda (sym)
 404                                   (intern (symbol-name sym) table)))
 405                                tags-completion-table))
 406                  (setq included (cdr included))))
 407              (setq tags-completion-table table))
 408            (message "Making tags completion table for %s...done"
 409                     buffer-file-name))
 410         (quit (message "Tags completion table construction aborted.")
 411               (setq tags-completion-table nil)))))
 412
 413 ;; Completion function for tags.  Does normal try-completion,
 414 ;; but builds tags-completion-table on demand.
 415 (defun tags-complete-tag (string predicate what)
 416   (save-excursion
 417     (visit-tags-table-buffer)
 418     (if (eq what t)
 419         (all-completions string (tags-completion-table) predicate)
 420       (try-completion string (tags-completion-table) predicate))))
 421
 422 ;; Return a default tag to search for, based on the text at point.
 423 (defun find-tag-default ()
 424   (save-excursion
 425     (while (looking-at "\\sw\\|\\s_")
 426       (forward-char 1))
 427     (if (or (re-search-backward "\\sw\\|\\s_"
 428                                 (save-excursion (beginning-of-line) (point))
 429                                 t)
 430             (re-search-forward "\\(\\sw\\|\\s_\\)+"
 431                                (save-excursion (end-of-line) (point))
 432                                t))
 433         (progn (goto-char (match-end 0))
 434                (buffer-substring (point)
 435                                  (progn (forward-sexp -1)
 436                                         (while (looking-at "\\s'")
 437                                           (forward-char 1))
 438                                         (point))))
 439       nil)))
 440
 441 ;; Read a tag name from the minibuffer with defaulting and completion.
 442 (defun find-tag-tag (string)
 443   (let* ((default (funcall (or find-tag-default-function
 444                                (get major-mode 'find-tag-default-function)
 445                                'find-tag-default)))
 446          (spec (completing-read (if default
 447                                     (format "%s(default %s) " string default)
 448                                   string)
 449                                 'tags-complete-tag)))
 450     (list (if (equal spec "")
 451               (or default (error "There is no default tag"))
 452             spec))))
 453
 454 (defvar last-tag nil
 455   "Last tag found by \\[find-tag].")
 456
 457 ;;;###autoload
 458 (defun find-tag-noselect (tagname &optional next-p regexp-p)
 459   "Find tag (in current tags table) whose name contains TAGNAME.
 460 Returns the buffer containing the tag's definition moves its point there,
 461 but does not select the buffer.
 462 The default for TAGNAME is the expression in the buffer near point.
 463
 464 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 465 for another tag that matches the last tagname or regexp used.  When there
 466 are multiple matches for a tag, more exact matches are found first.
 467
 468 If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
 469
 470 See documentation of variable `tags-file-name'."
 471   (interactive (if current-prefix-arg
 472                    '(nil t)
 473                  (find-tag-tag "Find tag: ")))
 474   (let ((local-find-tag-hook find-tag-hook))
 475     (if next-p
 476         (visit-tags-table-buffer 'same)
 477       (setq last-tag tagname)
 478       (visit-tags-table-buffer 'reset))
 479     (prog1
 480         (find-tag-in-order (if next-p last-tag tagname)
 481                            (if regexp-p
 482                                find-tag-regexp-search-function
 483                              find-tag-search-function)
 484                            (if regexp-p
 485                                find-tag-regexp-tag-order
 486                              find-tag-tag-order)
 487                            (if regexp-p
 488                                find-tag-regexp-next-line-after-failure-p
 489                              find-tag-next-line-after-failure-p)
 490                            (if regexp-p "matching" "containing")
 491                            (not next-p))
 492       (run-hooks 'local-find-tag-hook))))
 493
 494 ;;;###autoload
 495 (defun find-tag (tagname &optional next-p)
 496   "Find tag (in current tags table) whose name contains TAGNAME.
 497 Select the buffer containing the tag's definition, and move point there.
 498 The default for TAGNAME is the expression in the buffer around or before point.
 499
 500 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 501 for another tag that matches the last tagname used.  When there are
 502 multiple matches, more exact matches are found first.
 503
 504 See documentation of variable `tags-file-name'."
 505   (interactive (if current-prefix-arg
 506                    '(nil t)
 507                  (find-tag-tag "Find tag: ")))
 508   (switch-to-buffer (find-tag-noselect tagname next-p)))
 509 ;;;###autoload (define-key esc-map "." 'find-tag)
 510
 511 ;;;###autoload
 512 (defun find-tag-other-window (tagname &optional next-p)
 513   "Find tag (in current tags table) whose name contains TAGNAME.
 514 Select the buffer containing the tag's definition
 515 in another window, and move point there.
 516 The default for TAGNAME is the expression in the buffer around or before point.
 517
 518 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 519 for another tag that matches the last tagname used.  When there are
 520 multiple matches, more exact matches are found first.
 521
 522 See documentation of variable `tags-file-name'."
 523   (interactive (if current-prefix-arg
 524                    '(nil t)
 525                  (find-tag-tag "Find tag other window: ")))
 526   (switch-to-buffer-other-window (find-tag-noselect tagname next-p)))
 527 ;;;###autoload (define-key ctl-x-4-map "." 'find-tag-other-window)
 528
 529 ;;;###autoload
 530 (defun find-tag-other-frame (tagname &optional next-p)
 531   "Find tag (in current tag table) whose name contains TAGNAME.
 532  Selects the buffer that the tag is contained in in another frame
 533 and puts point at its definition.
 534  If TAGNAME is a null string, the expression in the buffer
 535 around or before point is used as the tag name.
 536  If second arg NEXT-P is non-nil (interactively, with prefix arg),
 537 searches for the next tag in the tag table
 538 that matches the tagname used in the previous find-tag.
 539
 540 See documentation of variable `tags-file-name'."
 541   (interactive (if current-prefix-arg
 542                    '(nil t)
 543                    (find-tag-tag "Find tag other window: ")))
 544   (let ((pop-up-frames t))
 545     (find-tag-other-window tagname next-p)))
 546 ;;;###autoload (define-key ctl-x-5-map "." 'find-tag-other-frame)
 547
 548 ;;;###autoload
 549 (defun find-tag-regexp (regexp &optional next-p other-window)
 550   "Find tag (in current tags table) whose name matches REGEXP.
 551 Select the buffer containing the tag's definition and move point there.
 552
 553 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 554 for another tag that matches the last tagname used.
 555
 556 If third arg OTHER-WINDOW is non-nil, select the buffer in another window.
 557
 558 See documentation of variable `tags-file-name'."
 559   (interactive (if current-prefix-arg
 560                    '(nil t)
 561                  (read-string "Find tag regexp: ")))
 562   (funcall (if other-window 'switch-to-buffer-other-window 'switch-to-buffer)
 563            (find-tag-noselect regexp next-p t)))
 564 \f
 565 ;; Internal tag finding function.
 566
 567 ;; PATTERN is a string to pass to second arg SEARCH-FORWARD-FUNC, and to
 568 ;; any member of the function list ORDER (third arg).  If ORDER is nil,
 569 ;; use saved state to continue a previous search.
 570
 571 ;; Fourth arg MATCHING is a string, an English '-ing' word, to be used in
 572 ;; an error message.
 573
 574 ;; Fifth arg NEXT-LINE-AFTER-FAILURE-P is non-nil if after a failed match,
 575 ;; point should be moved to the next line.
 576
 577 ;; Algorithm is as follows.  For each qualifier-func in ORDER, go to
 578 ;; beginning of tags file, and perform inner loop: for each naive match for
 579 ;; PATTERN found using SEARCH-FORWARD-FUNC, qualify the naive match using
 580 ;; qualifier-func.  If it qualifies, go to the specified line in the
 581 ;; specified source file and return.  Qualified matches are remembered to
 582 ;; avoid repetition.  State is saved so that the loop can be continued.
 583
 584 (defun find-tag-in-order (pattern search-forward-func order
 585                                   next-line-after-failure-p matching
 586                                   first-search)
 587   (let (file                            ;name of file containing tag
 588         tag-info                        ;where to find the tag in FILE
 589         tags-table-file                 ;name of tags file
 590         (first-table t)
 591         (tag-order order)
 592         goto-func
 593         )
 594     (save-excursion
 595       (or first-search
 596           (visit-tags-table-buffer))
 597       ;; Get a qualified match.
 598       (catch 'qualified-match-found
 599         (while (or first-table
 600                    (visit-tags-table-buffer t))
 601
 602           (if first-search
 603               (setq tag-lines-already-matched nil))
 604
 605           (and first-search first-table
 606                ;; Start at beginning of tags file.
 607                (goto-char (point-min)))
 608           (setq first-table nil)
 609
 610           (setq tags-table-file buffer-file-name)
 611           (while order
 612             (while (funcall search-forward-func pattern nil t)
 613               ;; Naive match found.  Qualify the match.
 614               (and (funcall (car order) pattern)
 615                    ;; Make sure it is not a previous qualified match.
 616                    ;; Use of `memq' depends on numbers being eq.
 617                    (not (memq (save-excursion (beginning-of-line) (point))
 618                               tag-lines-already-matched))
 619                    (throw 'qualified-match-found nil))
 620               (if next-line-after-failure-p
 621                   (forward-line 1)))
 622             ;; Try the next flavor of match.
 623             (setq order (cdr order))
 624             (goto-char (point-min)))
 625           (setq order tag-order))
 626         ;; We throw out on match, so only get here if there were no matches.
 627         (error "No %stags %s %s" (if first-search "" "more ")
 628                matching pattern))
 629
 630       ;; Found a tag; extract location info.
 631       (beginning-of-line)
 632       (setq tag-lines-already-matched (cons (point)
 633                                             tag-lines-already-matched))
 634       ;; Expand the filename, using the tags table buffer's default-directory.
 635       (setq file (expand-file-name (file-of-tag))
 636             tag-info (funcall snarf-tag-function))
 637
 638       ;; Get the local value in the tags table buffer.
 639       (setq goto-func goto-tag-location-function)
 640
 641       ;; Find the right line in the specified file.
 642       (set-buffer (find-file-noselect file))
 643       (widen)
 644       (push-mark)
 645       (funcall goto-func tag-info)
 646
 647       ;; Give this buffer a local value of tags-file-name.
 648       ;; The next time visit-tags-table-buffer is called,
 649       ;; it will use the same tags table that found a match in this buffer.
 650       (make-local-variable 'tags-file-name)
 651       (setq tags-file-name tags-table-file)
 652
 653       ;; Return the buffer where the tag was found.
 654       (current-buffer))))
 655 \f
 656 ;; `etags' TAGS file format support.
 657
 658 (defun etags-recognize-tags-table ()
 659   (and (eq (char-after 1) ?\f)
 660        ;; It is annoying to flash messages on the screen briefly,
 661        ;; and this message is not useful.  -- rms
 662        ;; (message "%s is an `etags' TAGS file" buffer-file-name)
 663        (mapcar (function (lambda (elt)
 664                            (make-local-variable (car elt))
 665                            (set (car elt) (cdr elt))))
 666                '((file-of-tag-function . etags-file-of-tag)
 667                  (tags-table-files-function . etags-tags-table-files)
 668                  (tags-completion-table-function . etags-tags-completion-table)
 669                  (snarf-tag-function . etags-snarf-tag)
 670                  (goto-tag-location-function . etags-goto-tag-location)
 671                  (find-tag-regexp-search-function . re-search-forward)
 672                  (find-tag-regexp-tag-order . (tag-re-match-p))
 673                  (find-tag-regexp-next-line-after-failuire-p . t)
 674                  (find-tag-search-function . search-forward)
 675                  (find-tag-tag-order . (tag-exact-match-p tag-word-match-p
 676                                                           tag-any-match-p))
 677                  (find-tag-next-line-after-failure-p . nil)
 678                  (list-tags-function . etags-list-tags)
 679                  (tags-apropos-function . etags-tags-apropos)
 680                  (tags-included-tables-function . etags-tags-included-tables)
 681                  (verify-tags-table-function . etags-verify-tags-table)
 682                  ))))
 683
 684 (defun etags-verify-tags-table ()
 685   (= (char-after 1) ?\f))
 686
 687 (defun etags-file-of-tag ()
 688   (save-excursion
 689     (search-backward "\f\n")
 690     (forward-char 2)
 691     (buffer-substring (point)
 692                       (progn (skip-chars-forward "^,") (point)))))
 693
 694 (defun etags-tags-completion-table ()
 695   (let ((table (make-vector 511 0)))
 696     (save-excursion
 697       (goto-char (point-min))
 698       (while (search-forward "\177" nil t)
 699         ;; Handle multiple \177's on a line.
 700         (save-excursion
 701           (skip-chars-backward "^-A-Za-z0-9_$\n") ;sym syntax? XXX
 702           (or (bolp)
 703               (intern (buffer-substring
 704                        (point)
 705                        (progn
 706                          (skip-chars-backward "-A-Za-z0-9_$")
 707                          ;; ??? New
 708                          ;; `::' in the middle of a C++ tag.
 709                          (and (= (preceding-char) ?:)
 710                               (= (char-after (- (point) 2)) ?:)
 711                               (progn
 712                                 (backward-char 2)
 713                                 (skip-chars-backward
 714                                  "-A-Za-z0-9_$")))
 715                          (point)))
 716                       table)))))
 717     table))
 718
 719 (defun etags-snarf-tag ()
 720   (let (tag-text startpos)
 721     (search-forward "\177")
 722     (setq tag-text (buffer-substring (1- (point))
 723                                      (save-excursion (beginning-of-line)
 724                                                      (point))))
 725     (search-forward ",")
 726     (setq startpos (string-to-int (buffer-substring
 727                                    (point)
 728                                    (progn (skip-chars-forward "0-9")
 729                                           (point)))))
 730     ;; Leave point on the next line of the tags file.
 731     (forward-line 1)
 732     (cons tag-text startpos)))
 733
 734 (defun etags-goto-tag-location (tag-info)
 735   (let ((startpos (cdr tag-info))
 736         ;; This constant is 1/2 the initial search window.
 737         ;; There is no sense in making it too small,
 738         ;; since just going around the loop once probably
 739         ;; costs about as much as searching 2000 chars.
 740         (offset 1000)
 741         (found nil)
 742         (pat (concat "^" (regexp-quote (car tag-info)))))
 743     (or startpos
 744         (setq startpos (point-min)))
 745     (while (and (not found)
 746                 (progn
 747                   (goto-char (- startpos offset))
 748                   (not (bobp))))
 749       (setq found
 750             (re-search-forward pat (+ startpos offset) t)
 751             offset (* 3 offset)))       ; expand search window
 752     (or found
 753         (re-search-forward pat nil t)
 754         (error "`%s' not found in %s; time to rerun etags"
 755                pat buffer-file-name)))
 756   (beginning-of-line))
 757
 758 (defun etags-list-tags (file)
 759   (goto-char 1)
 760   (if (not (search-forward (concat "\f\n" file ",") nil t))
 761       nil
 762     (forward-line 1)
 763     (while (not (or (eobp) (looking-at "\f")))
 764       (princ (buffer-substring (point)
 765                                (progn (skip-chars-forward "^\177")
 766                                       (point))))
 767       (terpri)
 768       (forward-line 1))))
 769
 770 (defun etags-tags-apropos (string)
 771   (goto-char 1)
 772   (while (re-search-forward string nil t)
 773     (beginning-of-line)
 774     (princ (buffer-substring (point)
 775                              (progn (skip-chars-forward "^\177")
 776                                     (point))))
 777     (terpri)
 778     (forward-line 1)))
 779
 780 (defun etags-tags-table-files ()
 781   (let ((files nil)
 782         beg)
 783     (goto-char (point-min))
 784     (while (search-forward "\f\n" nil t)
 785       (setq beg (point))
 786       (skip-chars-forward "^,\n")
 787       (or (looking-at ",include$")
 788           ;; Expand in the default-directory of the tags table buffer.
 789           (setq files (cons (expand-file-name (buffer-substring beg (point)))
 790                             files))))
 791     (nreverse files)))
 792
 793 (defun etags-tags-included-tables ()
 794   (let ((files nil)
 795         beg)
 796     (goto-char (point-min))
 797     (while (search-forward "\f\n" nil t)
 798       (setq beg (point))
 799       (skip-chars-forward "^,\n")
 800       (if (looking-at ",include$")
 801           ;; Expand in the default-directory of the tags table buffer.
 802           (setq files (cons (expand-file-name (buffer-substring beg (point)))
 803                             files))))
 804     (nreverse files)))
 805 \f
 806 ;; Empty tags file support.
 807
 808 (defun recognize-empty-tags-table ()
 809   (and (zerop (buffer-size))
 810        (mapcar (function (lambda (sym)
 811                            (make-local-variable sym)
 812                            (set sym 'ignore)))
 813                '(tags-table-files-function
 814                  tags-completion-table-function
 815                  find-tag-regexp-search-function
 816                  find-tag-search-function
 817                  tags-apropos-function
 818                  tags-included-tables-function))
 819        (set (make-local-variable 'verify-tags-table-function)
 820             (function (lambda ()
 821                         (zerop (buffer-size)))))))
 822 \f
 823 ;;; Match qualifier functions for tagnames.
 824
 825 ;; This might be a neat idea, but it's too hairy at the moment.
 826 ;;(defmacro tags-with-syntax (&rest body)
 827 ;;  (` (let ((current (current-buffer))
 828 ;;         (otable (syntax-table))
 829 ;;         (buffer (find-file-noselect (file-of-tag)))
 830 ;;         table)
 831 ;;       (unwind-protect
 832 ;;         (progn
 833 ;;           (set-buffer buffer)
 834 ;;           (setq table (syntax-table))
 835 ;;           (set-buffer current)
 836 ;;           (set-syntax-table table)
 837 ;;           (,@ body))
 838 ;;       (set-syntax-table otable)))))
 839 ;;(put 'tags-with-syntax 'edebug-form-spec '(&rest form))
 840
 841 ;; t if point is at a tag line that matches TAG "exactly".
 842 ;; point should be just after a string that matches TAG.
 843 (defun tag-exact-match-p (tag)
 844   (and (looking-at "\\Sw.*\177") (looking-at "\\S_.*\177") ;not a symbol char
 845        (save-excursion
 846          (backward-char (1+ (length tag)))
 847          (and (looking-at "\\Sw") (looking-at "\\S_")))))
 848
 849 ;; t if point is at a tag line that matches TAG as a word.
 850 ;; point should be just after a string that matches TAG.
 851 (defun tag-word-match-p (tag)
 852   (and (looking-at "\\b.*\177")
 853        (save-excursion (backward-char (1+ (length tag)))
 854                        (looking-at "\\b"))))
 855
 856 ;; t if point is in a tag line with a tag containing TAG as a substring.
 857 (defun tag-any-match-p (tag)
 858   (looking-at ".*\177"))
 859
 860 ;; t if point is at a tag line that matches RE as a regexp.
 861 (defun tag-re-match-p (re)
 862   (save-excursion
 863     (beginning-of-line)
 864     (let ((bol (point)))
 865       (and (search-forward "\177" (save-excursion (end-of-line) (point)) t)
 866            (re-search-backward re bol t)))))
 867 \f
 868 ;;;###autoload
 869 (defun next-file (&optional initialize novisit)
 870   "Select next file among files in current tags table.
 871 Non-nil first argument (prefix arg, if interactive)
 872 initializes to the beginning of the list of files in the tags table.
 873
 874 Non-nil second argument NOVISIT means use a temporary buffer
 875  to save time and avoid uninteresting warnings.
 876
 877 Value is nil if the file was already visited;
 878 if the file was newly read in, the value is the filename."
 879   (interactive "P")
 880   (and initialize
 881        (save-excursion
 882          (visit-tags-table-buffer 'reset)
 883          (setq next-file-list (tags-table-files))))
 884   (or next-file-list
 885       (save-excursion
 886         ;; When doing (visit-tag-table-buffer t),
 887         ;; the tags table buffer must be current.
 888         (if (and (visit-tags-table-buffer 'same)
 889                  (visit-tags-table-buffer t))
 890             (setq next-file-list (tags-table-files))
 891           (and novisit
 892                (get-buffer " *next-file*")
 893                (kill-buffer " *next-file*"))
 894           (error "All files processed."))))
 895   (let ((new (not (get-file-buffer (car next-file-list)))))
 896     (if (not (and new novisit))
 897         (set-buffer (find-file-noselect (car next-file-list) novisit))
 898       ;; Like find-file, but avoids random warning messages.
 899       (set-buffer (get-buffer-create " *next-file*"))
 900       (kill-all-local-variables)
 901       (erase-buffer)
 902       (setq new (car next-file-list))
 903       (insert-file-contents new nil))
 904     (setq next-file-list (cdr next-file-list))
 905     new))
 906
 907 (defvar tags-loop-operate nil
 908   "Form for `tags-loop-continue' to eval to change one file.")
 909
 910 (defvar tags-loop-scan nil
 911   "Form for `tags-loop-continue' to eval to scan one file.
 912 If it returns non-nil, this file needs processing by evalling
 913 \`tags-loop-operate'.  Otherwise, move on to the next file.")
 914
 915 ;;;###autoload
 916 (defun tags-loop-continue (&optional first-time)
 917   "Continue last \\[tags-search] or \\[tags-query-replace] command.
 918 Used noninteractively with non-nil argument to begin such a command.
 919 Two variables control the processing we do on each file:
 920 the value of `tags-loop-scan' is a form to be executed on each file
 921 to see if it is interesting (it returns non-nil if so)
 922 and `tags-loop-operate' is a form to execute to operate on an interesting file
 923 If the latter returns non-nil, we exit; otherwise we scan the next file."
 924   (interactive)
 925   (let (new
 926         (messaged nil))
 927     (while
 928         (progn
 929           ;; Scan files quickly for the first or next interesting one.
 930           (while (or first-time
 931                      (save-restriction
 932                        (widen)
 933                        (not (eval tags-loop-scan))))
 934             (setq new (next-file first-time t))
 935             ;; If NEW is non-nil, we got a temp buffer,
 936             ;; and NEW is the file name.
 937             (if (or messaged
 938                     (and (not first-time)
 939                          (> baud-rate search-slow-speed)
 940                          (setq messaged t)))
 941                 (message "Scanning file %s..." (or new buffer-file-name)))
 942             (setq first-time nil)
 943             (goto-char (point-min)))
 944
 945           ;; If we visited it in a temp buffer, visit it now for real.
 946           (if new
 947               (let ((pos (point)))
 948                 (erase-buffer)
 949                 (set-buffer (find-file-noselect new))
 950                 (widen)
 951                 (goto-char pos)))
 952
 953           (switch-to-buffer (current-buffer))
 954
 955           ;; Now operate on the file.
 956           ;; If value is non-nil, continue to scan the next file.
 957           (eval tags-loop-operate)))
 958     (and messaged
 959          (null tags-loop-operate)
 960          (message "Scanning file %s...found" buffer-file-name))))
 961
 962 ;;;###autoload (define-key esc-map "," 'tags-loop-continue)
 963
 964 ;;;###autoload
 965 (defun tags-search (regexp)
 966   "Search through all files listed in tags table for match for REGEXP.
 967 Stops when a match is found.
 968 To continue searching for next match, use command \\[tags-loop-continue].
 969
 970 See documentation of variable `tags-file-name'."
 971   (interactive "sTags search (regexp): ")
 972   (if (and (equal regexp "")
 973            (eq (car tags-loop-scan) 're-search-forward)
 974            (eq tags-loop-operate t))
 975       ;; Continue last tags-search as if by M-,.
 976       (tags-loop-continue nil)
 977     (setq tags-loop-scan
 978           (list 're-search-forward regexp nil t)
 979           tags-loop-operate nil)
 980     (tags-loop-continue t)))
 981
 982 ;;;###autoload
 983 (defun tags-query-replace (from to &optional delimited)
 984   "Query-replace-regexp FROM with TO through all files listed in tags table.
 985 Third arg DELIMITED (prefix arg) means replace only word-delimited matches.
 986 If you exit (\\[keyboard-quit] or ESC), you can resume the query-replace
 987 with the command \\[tags-loop-continue].
 988
 989 See documentation of variable `tags-file-name'."
 990   (interactive
 991    "sTags query replace (regexp): \nsTags query replace %s by: \nP")
 992   (setq tags-loop-scan (list 'prog1
 993                              (list 'if (list 're-search-forward form nil t)
 994                                    ;; When we find a match, move back
 995                                    ;; to the beginning of it so perform-replace
 996                                    ;; will see it.
 997                                    '(goto-char (match-beginning 0))))
 998         tags-loop-operate (list 'perform-replace from to t t delimited))
 999   (tags-loop-continue t))
1000 \f
1001 ;;;###autoload
1002 (defun list-tags (file)
1003   "Display list of tags in file FILE.
1004 FILE should not contain a directory specification
1005 unless it has one in the tags table."
1006   (interactive (list (completing-read "List tags in file: " nil
1007                                       'tags-table-files t nil)))
1008   (with-output-to-temp-buffer "*Tags List*"
1009     (princ "Tags in file ")
1010     (princ file)
1011     (terpri)
1012     (save-excursion
1013       (let ((first-time t)
1014             (gotany nil))
1015         (while (visit-tags-table-buffer (if first-time 'reset t))
1016           (if (funcall list-tags-function file)
1017               (setq gotany t)))
1018         (or gotany
1019             (error "File %s not in current tags tables"))))))
1020
1021 ;;;###autoload
1022 (defun tags-apropos (regexp)
1023   "Display list of all tags in tags table REGEXP matches."
1024   (interactive "sTags apropos (regexp): ")
1025   (with-output-to-temp-buffer "*Tags List*"
1026     (princ "Tags matching regexp ")
1027     (prin1 regexp)
1028     (terpri)
1029     (save-excursion
1030       (let ((first-time nil))
1031         (while (visit-tags-table-buffer (if first-time 'reset t))
1032           (funcall tags-apropos-function))))))
1033 \f
1034 ;;; XXX Kludge interface.
1035
1036 ;; XXX If a file is in multiple tables, selection may get the wrong one.
1037 ;;;###autoload
1038 (defun select-tags-table ()
1039   "Select a tags table file from a menu of those you have already used.
1040 The list of tags tables to select from is stored in `tags-table-file-list';
1041 see the doc of that variable if you want to add names to the list."
1042   (interactive)
1043   (pop-to-buffer "*Tags Table List*")
1044   (setq buffer-read-only nil)
1045   (erase-buffer)
1046   (setq selective-display t
1047         selective-display-ellipses nil)
1048   (let ((set-list tags-table-set-list)
1049         (desired-point nil))
1050     (if tags-table-list
1051         (progn
1052           (setq desired-point (point-marker))
1053           (princ tags-table-list (current-buffer))
1054           (insert "\C-m")
1055           (prin1 (car tags-table-list) (current-buffer)) ;invisible
1056           (insert "\n")))
1057     (while set-list
1058       (if (eq (car set-list) tags-table-list)
1059           ;; Already printed it.
1060           ()
1061         (princ (car set-list) (current-buffer))
1062         (insert "\C-m")
1063         (prin1 (car (car set-list)) (current-buffer)) ;invisible
1064         (insert "\n"))
1065       (setq set-list (cdr set-list)))
1066     (if tags-file-name
1067         (progn
1068           (or desired-point
1069               (setq desired-point (point-marker)))
1070           (insert tags-file-name "\C-m")
1071           (prin1 tags-file-name (current-buffer)) ;invisible
1072           (insert "\n")))
1073     (setq set-list (delete tags-file-name
1074                            (apply 'nconc (cons tags-table-list
1075                                                (mapcar 'copy-sequence
1076                                                        tags-table-set-list)))))
1077     (while set-list
1078       (insert (car set-list) "\C-m")
1079       (prin1 (car set-list) (current-buffer)) ;invisible
1080       (insert "\n")
1081       (setq set-list (delete (car set-list) set-list)))
1082     (goto-char 1)
1083     (insert-before-markers
1084      "Type `t' to select a tags table or set of tags tables:\n\n")
1085     (if desired-point
1086         (goto-char desired-point))
1087     (set-window-start (selected-window) 1 t))
1088   (set-buffer-modified-p nil)
1089   (setq buffer-read-only t
1090         mode-name "Select Tags Table")
1091   (let ((map (make-sparse-keymap)))
1092     (define-key map "t" 'select-tags-table-select)
1093     (define-key map " " 'next-line)
1094     (define-key map "\^?" 'previous-line)
1095     (define-key map "n" 'next-line)
1096     (define-key map "p" 'previous-line)
1097     (define-key map "q" 'select-tags-table-quit)
1098     (use-local-map map)))
1099
1100 (defun select-tags-table-select ()
1101   "Select the tags table named on this line."
1102   (interactive)
1103   (search-forward "\C-m")
1104   (let ((name (read (current-buffer))))
1105     (visit-tags-table name)
1106     (select-tags-table-quit)
1107     (message "Tags table now %s" name)))
1108
1109 (defun select-tags-table-quit ()
1110   "Kill the buffer and delete the selected window."
1111   (interactive)
1112   (kill-buffer (current-buffer))
1113   (or (one-window-p)
1114       (delete-window)))
1115 \f
1116 ;;;###autoload
1117 (defun complete-tag ()
1118   "Perform tags completion on the text around point.
1119 Completes to the set of names listed in the current tags table.
1120 The string to complete is chosen in the same way as the default
1121 for \\[find-tag] (which see)."
1122   (interactive)
1123   (or tags-table-list
1124       tags-file-name
1125       (error (substitute-command-keys
1126               "No tags table loaded.  Try \\[visit-tags-table].")))
1127   (let ((pattern (funcall (or find-tag-default-function
1128                               (get major-mode 'find-tag-default-function)
1129                               'find-tag-default)))
1130         beg
1131         completion)
1132     (or pattern
1133         (error "Nothing to complete"))
1134     (search-backward pattern)
1135     (setq beg (point))
1136     (forward-char (length pattern))
1137     (setq completion (try-completion pattern 'tags-complete-tag nil))
1138     (cond ((eq completion t))
1139           ((null completion)
1140            (message "Can't find completion for \"%s\"" pattern)
1141            (ding))
1142           ((not (string= pattern completion))
1143            (delete-region beg (point))
1144            (insert completion))
1145           (t
1146            (message "Making completion list...")
1147            (with-output-to-temp-buffer " *Completions*"
1148              (display-completion-list
1149               (all-completions pattern 'tags-complete-tag nil)))
1150            (message "Making completion list...%s" "done")))))
1151
1152 ;;;###autoload (define-key esc-map "\t" 'complete-tag)
1153 \f
1154 (provide 'etags)
1155
1156 ;;; etags.el ends here