lisp/progmodes/etags.el

   1 ;; etags.el --- etags facility for Emacs
   2
   3 ;; Copyright (C) 1985, 1986, 1988, 1989, 1992, 1993
   4 ;;      Free Software Foundation, Inc.
   5
   6 ;; Author: Roland McGrath <roland@gnu.ai.mit.edu>
   7 ;; Keywords: tools
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;;; Code:
  26
  27 ;;;###autoload
  28 (defvar tags-file-name nil
  29   "*File name of tags table.
  30 To switch to a new tags table, setting this variable is sufficient.
  31 If you set this variable, do not also set `tags-table-list'.
  32 Use the `etags' program to make a tags table file.")
  33 ;; Make M-x set-variable tags-file-name like M-x visit-tags-table.
  34 ;;;###autoload (put 'tags-file-name 'variable-interactive "fVisit tags table: ")
  35
  36 ;;;###autoload
  37 ;; Use `visit-tags-table-buffer' to cycle through tags tables in this list.
  38 (defvar tags-table-list nil
  39   "*List of file names of tags tables to search.
  40 An element that is a directory means the file \"TAGS\" in that directory.
  41 To switch to a new list of tags tables, setting this variable is sufficient.
  42 If you set this variable, do not also set `tags-file-name'.
  43 Use the `etags' program to make a tags table file.")
  44
  45 (defvar tags-table-list-pointer nil
  46   "Pointer into `tags-table-list' where the current state of searching is.
  47 Might instead point into a list of included tags tables.
  48 Use `visit-tags-table-buffer' to cycle through tags tables in this list.")
  49
  50 (defvar tags-table-list-started-at nil
  51   "Pointer into `tags-table-list', where the current search started.")
  52
  53 (defvar tags-table-parent-pointer-list nil
  54   "Saved state of the tags table that included this one.
  55 Each element is (POINTER . STARTED-AT), giving the values of
  56  `tags-table-list-pointer' and `tags-table-list-started-at' from
  57  before we moved into the current table.")
  58
  59 (defvar tags-table-set-list nil
  60   "List of sets of tags table which have been used together in the past.
  61 Each element is a list of strings which are file names.")
  62
  63 ;;;###autoload
  64 (defvar find-tag-hook nil
  65   "*Hook to be run by \\[find-tag] after finding a tag.  See `run-hooks'.
  66 The value in the buffer in which \\[find-tag] is done is used,
  67 not the value in the buffer \\[find-tag] goes to.")
  68
  69 ;;;###autoload
  70 (defvar find-tag-default-function nil
  71   "*A function of no arguments used by \\[find-tag] to pick a default tag.
  72 If nil, and the symbol that is the value of `major-mode'
  73 has a `find-tag-default-function' property (see `put'), that is used.
  74 Otherwise, `find-tag-default' is used.")
  75
  76 ;;;###autoload
  77 (defvar default-tags-table-function nil
  78   "*If non-nil, a function of no arguments to choose a default tags file
  79 for a particular buffer.")
  80 \f
  81 ;; Tags table state.
  82 ;; These variables are local in tags table buffers.
  83
  84 (defvar tag-lines-already-matched nil
  85   "List of positions of beginnings of lines within the tags table
  86 that are already matched.")
  87
  88 (defvar tags-table-files nil
  89   "List of file names covered by current tags table.
  90 nil means it has not yet been computed; use `tags-table-files' to do so.")
  91
  92 (defvar tags-completion-table nil
  93   "Alist of tag names defined in current tags table.")
  94
  95 (defvar tags-included-tables nil
  96   "List of tags tables included by the current tags table.")
  97
  98 (defvar next-file-list nil
  99   "List of files for \\[next-file] to process.")
 100 \f
 101 ;; Hooks for file formats.
 102
 103 (defvar tags-table-format-hooks '(etags-recognize-tags-table
 104                                   recognize-empty-tags-table)
 105   "List of functions to be called in a tags table buffer to identify
 106 the type of tags table.  The functions are called in order, with no arguments,
 107 until one returns non-nil.  The function should make buffer-local bindings
 108 of the format-parsing tags function variables if successful.")
 109
 110 (defvar file-of-tag-function nil
 111   "Function to do the work of `file-of-tag' (which see).")
 112 (defvar tags-table-files-function nil
 113   "Function to do the work of `tags-table-files' (which see).")
 114 (defvar tags-completion-table-function nil
 115   "Function to build the tags-completion-table.")
 116 (defvar snarf-tag-function nil
 117   "Function to get info about a matched tag for `goto-tag-location-function'.")
 118 (defvar goto-tag-location-function nil
 119   "Function of to go to the location in the buffer specified by a tag.
 120 One argument, the tag info returned by `snarf-tag-function'.")
 121 (defvar find-tag-regexp-search-function nil
 122   "Search function passed to `find-tag-in-order' for finding a regexp tag.")
 123 (defvar find-tag-regexp-tag-order nil
 124   "Tag order passed to `find-tag-in-order' for finding a regexp tag.")
 125 (defvar find-tag-regexp-next-line-after-failure-p nil
 126   "Flag passed to `find-tag-in-order' for finding a regexp tag.")
 127 (defvar find-tag-search-function nil
 128   "Search function passed to `find-tag-in-order' for finding a tag.")
 129 (defvar find-tag-tag-order nil
 130   "Tag order passed to `find-tag-in-order' for finding a tag.")
 131 (defvar find-tag-next-line-after-failure-p nil
 132   "Flag passed to `find-tag-in-order' for finding a tag.")
 133 (defvar list-tags-function nil
 134   "Function to do the work of `list-tags' (which see).")
 135 (defvar tags-apropos-function nil
 136   "Function to do the work of `tags-apropos' (which see).")
 137 (defvar tags-included-tables-function nil
 138   "Function to do the work of `tags-included-tables' (which see).")
 139 (defvar verify-tags-table-function nil
 140   "Function to return t iff the current buffer vontains a valid
 141 \(already initialized\) tags file.")
 142 \f
 143 ;; Initialize the tags table in the current buffer.
 144 ;; Returns non-nil iff it is a valid tags table.  On
 145 ;; non-nil return, the tags table state variable are
 146 ;; made buffer-local and initialized to nil.
 147 (defun initialize-new-tags-table ()
 148   (set (make-local-variable 'tag-lines-already-matched) nil)
 149   (set (make-local-variable 'tags-table-files) nil)
 150   (set (make-local-variable 'tags-completion-table) nil)
 151   (set (make-local-variable 'tags-included-tables) nil)
 152   ;; Value is t if we have found a valid tags table buffer.
 153   (let ((hooks tags-table-format-hooks))
 154     (while (and hooks
 155                 (not (funcall (car hooks))))
 156       (setq hooks (cdr hooks)))
 157     hooks))
 158
 159 ;;;###autoload
 160 (defun visit-tags-table (file &optional local)
 161   "Tell tags commands to use tags table file FILE.
 162 FILE should be the name of a file created with the `etags' program.
 163 A directory name is ok too; it means file TAGS in that directory.
 164
 165 Normally \\[visit-tags-table] sets the global value of `tags-file-name'.
 166 With a prefix arg, set the buffer-local value instead.
 167 When you find a tag with \\[find-tag], the buffer it finds the tag
 168 in is given a local value of this variable which is the name of the tags
 169 file the tag was in."
 170   (interactive (list (read-file-name "Visit tags table: (default TAGS) "
 171                                      default-directory
 172                                      (expand-file-name "TAGS"
 173                                                        default-directory)
 174                                      t)
 175                      current-prefix-arg))
 176   ;; Calling visit-tags-table-buffer with tags-file-name set to FILE will
 177   ;; initialize a buffer for FILE and set tags-file-name to the
 178   ;; fully-expanded name.
 179   (let ((tags-file-name file))
 180     (save-excursion
 181       (or (visit-tags-table-buffer 'same)
 182           (signal 'file-error (list "Visiting tags table"
 183                                     "file does not exist"
 184                                     file)))
 185       ;; Set FILE to the expanded name.
 186       (setq file tags-file-name)))
 187   (if local
 188       ;; Set the local value of tags-file-name.
 189       (set (make-local-variable 'tags-file-name) file)
 190     ;; Set the global value of tags-file-name.
 191     (setq-default tags-file-name file)))
 192
 193 ;; Move tags-table-list-pointer along and set tags-file-name.
 194 ;; If NO-INCLUDES is non-nil, ignore included tags tables.
 195 ;; Returns nil when out of tables.
 196 (defun tags-next-table (&optional no-includes)
 197   ;; Do we have any included tables?
 198   (if (and (not no-includes)
 199            (visit-tags-table-buffer 'same)
 200            (tags-included-tables))
 201
 202       ;; Move into the included tags tables.
 203       (setq tags-table-parent-pointer-list
 204             ;; Save the current state of what table we are in.
 205             (cons (cons tags-table-list-pointer tags-table-list-started-at)
 206                   tags-table-parent-pointer-list)
 207             ;; Start the pointer in the list of included tables.
 208             tags-table-list-pointer tags-included-tables
 209             tags-table-list-started-at tags-included-tables)
 210
 211     ;; No included tables.  Go to the next table in the list.
 212     (setq tags-table-list-pointer
 213           (cdr tags-table-list-pointer))
 214     (or tags-table-list-pointer
 215         ;; Wrap around.
 216         (setq tags-table-list-pointer tags-table-list))
 217
 218     (if (eq tags-table-list-pointer tags-table-list-started-at)
 219         ;; We have come full circle.  No more tables.
 220         (if tags-table-parent-pointer-list
 221             ;; Pop back to the tags table which includes this one.
 222             (progn
 223               ;; Restore the state variables.
 224               (setq tags-table-list-pointer
 225                     (car (car tags-table-parent-pointer-list))
 226                     tags-table-list-started-at
 227                     (cdr (car tags-table-parent-pointer-list))
 228                     tags-table-parent-pointer-list
 229                     (cdr tags-table-parent-pointer-list))
 230               ;; Recurse to skip to the next table after the parent.
 231               (tags-next-table t))
 232           ;; All out of tags tables.
 233           (setq tags-table-list-pointer nil))))
 234
 235   (and tags-table-list-pointer
 236        ;; Set tags-file-name to the fully-expanded name.
 237        (setq tags-file-name
 238              (tags-expand-table-name (car tags-table-list-pointer)))))
 239
 240 ;; Expand tags table name FILE into a complete file name.
 241 (defun tags-expand-table-name (file)
 242   (setq file (expand-file-name file))
 243   (if (file-directory-p file)
 244       (expand-file-name "TAGS" file)
 245     file))
 246
 247 ;; Return the cdr of LIST (default: tags-table-list) whose car
 248 ;; is equal to FILE after tags-expand-table-name on both sides.
 249 (defun tags-table-list-member (file &optional list)
 250   (or list
 251       (setq list tags-table-list))
 252   (setq file (tags-expand-table-name file))
 253   (while (and list
 254               (not (string= file (tags-expand-table-name (car list)))))
 255     (setq list (cdr list)))
 256   list)
 257
 258 ;; Subroutine of visit-tags-table-buffer.  Frobs its local vars.
 259 ;; Search TABLES for one that has tags for THIS-FILE.  Recurses
 260 ;; on included tables.  Returns the tail of TABLES (or of an
 261 ;; inner included list) whose car is a table listing THIS-FILE.
 262 (defun tags-table-including (this-file tables &optional recursing)
 263   (let ((found nil))
 264     ;; Loop over TABLES, looking for one containing tags for THIS-FILE.
 265     (while (and (not found)
 266                 tables)
 267       (let ((tags-file-name (tags-expand-table-name (car tables))))
 268         (if (or (get-file-buffer tags-file-name)
 269                 (file-exists-p tags-file-name)) ;XXX check all in core first.
 270             (progn
 271               ;; Select the tags table buffer and get the file list up to date.
 272               (visit-tags-table-buffer 'same)
 273               (or tags-table-files
 274                   (setq tags-table-files
 275                         (funcall tags-table-files-function)))
 276
 277               (cond ((member this-file tags-table-files)
 278                      ;; Found it.
 279                      (setq found tables))
 280
 281                     ((tags-included-tables)
 282                      ;; This table has included tables.  Check them.
 283                      (let ((old tags-table-parent-pointer-list))
 284                        (unwind-protect
 285                            (progn
 286                              (or recursing
 287                                  ;; At top level (not in an included tags
 288                                  ;; table), set the list to nil so we can
 289                                  ;; collect just the elts from this run.
 290                                  (setq tags-table-parent-pointer-list nil))
 291                              (setq found
 292                                    ;; Recurse on the list of included tables.
 293                                    (tags-table-including this-file
 294                                                          tags-included-tables
 295                                                          t))
 296                              (if found
 297                                  ;; One of them lists THIS-FILE.
 298                                  ;; Set the table list state variables to move
 299                                  ;; us inside the list of included tables.
 300                                  (setq tags-table-parent-pointer-list
 301                                        (cons
 302                                         (cons tags-table-list-pointer
 303                                               tags-table-list-started-at)
 304                                         tags-table-parent-pointer-list)
 305                                        tags-table-list-pointer found
 306                                        tags-table-list-started-at found
 307                                        ;; CONT is a local variable of
 308                                        ;; our caller, visit-tags-table-buffer.
 309                                        ;; Set it so we won't frob lists later.
 310                                        cont 'included)))
 311                          (or recursing
 312                              ;; tags-table-parent-pointer-list now describes
 313                              ;; the path of included tables taken by recursive
 314                              ;; invocations of this function.  The recursive
 315                              ;; calls have consed onto the front of the list,
 316                              ;; so it is now outermost first.  We want it
 317                              ;; innermost first, so reverse it.  Then append
 318                              ;; the old list (from before we were called the
 319                              ;; outermost time), to get the complete current
 320                              ;; state of included tables.
 321                              (setq tags-table-parent-pointer-list
 322                                    (nconc (nreverse
 323                                            tags-table-parent-pointer-list)
 324                                           old))))))))))
 325       (setq tables (cdr tables)))
 326     found))
 327
 328 (defun visit-tags-table-buffer (&optional cont)
 329   "Select the buffer containing the current tags table.
 330 If optional arg is t, visit the next table in `tags-table-list'.
 331 If optional arg is the atom `same', don't look for a new table;
 332  just select the buffer visiting `tags-file-name'.
 333 If arg is nil or absent, choose a first buffer from information in
 334  `tags-file-name', `tags-table-list', `tags-table-list-pointer'.
 335 Returns t if it visits a tags table, or nil if there are no more in the list."
 336
 337   ;; Set tags-file-name to the tags table file we want to visit.
 338   (cond ((eq cont 'same)
 339          ;; Use the ambient value of tags-file-name.
 340          (or tags-file-name
 341              (error (substitute-command-keys
 342                      (concat "No tags table in use!  "
 343                              "Use \\[visit-tags-table] to select one."))))
 344          ;; Set CONT to nil so the code below will make sure tags-file-name
 345          ;; is in tags-table-list.
 346          (setq cont nil))
 347
 348         (cont
 349          ;; Find the next table.
 350          (if (tags-next-table)
 351              ;; Skip over nonexistent files.
 352              (while (and (let ((file (tags-expand-table-name tags-file-name)))
 353                            (not (or (get-file-buffer file)
 354                                     (file-exists-p file))))
 355                          (tags-next-table)))))
 356
 357         (t
 358          ;; Pick a table out of our hat.
 359          (setq tags-file-name
 360                (or
 361                 ;; First, try a local variable.
 362                 (cdr (assq 'tags-file-name (buffer-local-variables)))
 363                 ;; Second, try a user-specified function to guess.
 364                 (and default-tags-table-function
 365                      (funcall default-tags-table-function))
 366                 ;; Third, look for a tags table that contains
 367                 ;; tags for the current buffer's file.
 368                 ;; If one is found, the lists will be frobnicated,
 369                 ;; and CONT will be set non-nil so we don't do it below.
 370                 (car (save-excursion (tags-table-including buffer-file-name
 371                                                            tags-table-list)))
 372                 ;; Fourth, use the user variable tags-file-name, if it is not
 373                 ;; already in tags-table-list.
 374                 (and tags-file-name
 375                      (not (tags-table-list-member tags-file-name))
 376                      tags-file-name)
 377                 ;; Fifth, use the user variable giving the table list.
 378                 ;; Find the first element of the list that actually exists.
 379                 (let ((list tags-table-list)
 380                       file)
 381                   (while (and list
 382                               (setq file (tags-expand-table-name (car list)))
 383                               (not (get-file-buffer file))
 384                               (not (file-exists-p file)))
 385                     (setq list (cdr list)))
 386                   (car list))
 387                 ;; Finally, prompt the user for a file name.
 388                 (expand-file-name
 389                  (read-file-name "Visit tags table: (default TAGS) "
 390                                  default-directory
 391                                  "TAGS"
 392                                  t))))))
 393
 394   ;; Expand the table name into a full file name.
 395   (setq tags-file-name (tags-expand-table-name tags-file-name))
 396
 397   (if (and (eq cont t) (null tags-table-list-pointer))
 398       ;; All out of tables.
 399       nil
 400
 401     ;; Verify that tags-file-name is a valid tags table.
 402     (if (if (get-file-buffer tags-file-name)
 403             ;; The file is already in a buffer.  Check for the visited file
 404             ;; having changed since we last used it.
 405             (let (win)
 406               (set-buffer (get-file-buffer tags-file-name))
 407               (setq win (or verify-tags-table-function
 408                             (initialize-new-tags-table)))
 409               (if (or (verify-visited-file-modtime (current-buffer))
 410                       (not (yes-or-no-p
 411                             "Tags file has changed, read new contents? ")))
 412                   (and win (funcall verify-tags-table-function))
 413                 (revert-buffer t t)
 414                 (initialize-new-tags-table)))
 415           (set-buffer (find-file-noselect tags-file-name))
 416           (or (string= tags-file-name buffer-file-name)
 417               ;; find-file-noselect has changed the file name.
 418               ;; Propagate the change to tags-file-name and tags-table-list.
 419               (let ((tail (member tags-file-name tags-table-list)))
 420                 (if tail
 421                     (setcar tail buffer-file-name))
 422                 (setq tags-file-name buffer-file-name)))
 423           (initialize-new-tags-table))
 424
 425         ;; We have a valid tags table.
 426         (progn
 427           ;; Bury the tags table buffer so it
 428           ;; doesn't get in the user's way.
 429           (bury-buffer (current-buffer))
 430
 431           (if cont
 432               ;; No list frobbing required.
 433               nil
 434
 435             ;; Look in the list for the table we chose.
 436             (let ((elt (tags-table-list-member tags-file-name)))
 437               (or elt
 438                   ;; The table is not in the current set.
 439                   ;; Try to find it in another previously used set.
 440                   (let ((sets tags-table-set-list))
 441                     (while (and sets
 442                                 (not (setq elt (tags-table-list-member
 443                                                 tags-file-name (car sets)))))
 444                       (setq sets (cdr sets)))
 445                     (if sets
 446                         ;; Found in some other set.  Switch to that set.
 447                         (progn
 448                           (or (memq tags-table-list tags-table-set-list)
 449                               ;; Save the current list.
 450                               (setq tags-table-set-list
 451                                     (cons tags-table-list
 452                                           tags-table-set-list)))
 453                           (setq tags-table-list (car sets)))
 454
 455                       ;; Not found in any existing set.
 456                       (if (and tags-table-list
 457                                (y-or-n-p (concat "Add " tags-file-name
 458                                                  " to current list"
 459                                                  " of tags tables? ")))
 460                           ;; Add it to the current list.
 461                           (setq tags-table-list (cons tags-file-name
 462                                                       tags-table-list))
 463                         ;; Make a fresh list, and store the old one.
 464                         (or (memq tags-table-list tags-table-set-list)
 465                             (setq tags-table-set-list
 466                                   (cons tags-table-list tags-table-set-list)))
 467                         (setq tags-table-list (list tags-file-name)))
 468                       (setq elt tags-table-list))))
 469
 470               ;; Set the tags table list state variables to point at the table
 471               ;; we want to use first.
 472               (setq tags-table-list-started-at elt
 473                     tags-table-list-pointer elt)))
 474
 475           ;; Return of t says the tags table is valid.
 476           t)
 477
 478       ;; The buffer was not valid.  Don't use it again.
 479       (let ((file tags-file-name))
 480         (kill-local-variable 'tags-file-name)
 481         (if (eq file tags-file-name)
 482             (setq tags-file-name nil)))
 483       (error "File %s is not a valid tags table" buffer-file-name))))
 484 \f
 485 (defun file-of-tag ()
 486   "Return the file name of the file whose tags point is within.
 487 Assumes the tags table is the current buffer.
 488 File name returned is relative to tags table file's directory."
 489   (funcall file-of-tag-function))
 490
 491 ;;;###autoload
 492 (defun tags-table-files ()
 493   "Return a list of files in the current tags table.
 494 Assumes the tags table is the current buffer.
 495 File names returned are absolute."
 496   (or tags-table-files
 497       (setq tags-table-files
 498             (funcall tags-table-files-function))))
 499
 500 (defun tags-included-tables ()
 501   "Return a list of tags tables included by the current table.
 502 Assumes the tags table is the current buffer."
 503   (or tags-included-tables
 504       (setq tags-included-tables (funcall tags-included-tables-function))))
 505 \f
 506 ;; Build tags-completion-table on demand.  The single current tags table
 507 ;; and its included tags tables (and their included tables, etc.) have
 508 ;; their tags included in the completion table.
 509 (defun tags-completion-table ()
 510   (or tags-completion-table
 511       (condition-case ()
 512           (prog2
 513            (message "Making tags completion table for %s..." buffer-file-name)
 514            (let ((included (tags-included-tables))
 515                  (table (funcall tags-completion-table-function)))
 516              (save-excursion
 517                ;; Iterate over the list of included tables, and combine each
 518                ;; included table's completion obarray to the parent obarray.
 519                (while included
 520                  ;; Visit the buffer.
 521                  (let ((tags-file-name (car included)))
 522                    (visit-tags-table-buffer 'same))
 523                  ;; Recurse in that buffer to compute its completion table.
 524                  (if (tags-completion-table)
 525                      ;; Combine the tables.
 526                      (mapatoms (function
 527                                 (lambda (sym)
 528                                   (intern (symbol-name sym) table)))
 529                                tags-completion-table))
 530                  (setq included (cdr included))))
 531              (setq tags-completion-table table))
 532            (message "Making tags completion table for %s...done"
 533                     buffer-file-name))
 534         (quit (message "Tags completion table construction aborted.")
 535               (setq tags-completion-table nil)))))
 536
 537 ;; Completion function for tags.  Does normal try-completion,
 538 ;; but builds tags-completion-table on demand.
 539 (defun tags-complete-tag (string predicate what)
 540   (save-excursion
 541     (visit-tags-table-buffer)
 542     (if (eq what t)
 543         (all-completions string (tags-completion-table) predicate)
 544       (try-completion string (tags-completion-table) predicate))))
 545 \f
 546 ;; Return a default tag to search for, based on the text at point.
 547 (defun find-tag-default ()
 548   (save-excursion
 549     (while (looking-at "\\sw\\|\\s_")
 550       (forward-char 1))
 551     (if (or (re-search-backward "\\sw\\|\\s_"
 552                                 (save-excursion (beginning-of-line) (point))
 553                                 t)
 554             (re-search-forward "\\(\\sw\\|\\s_\\)+"
 555                                (save-excursion (end-of-line) (point))
 556                                t))
 557         (progn (goto-char (match-end 0))
 558                (buffer-substring (point)
 559                                  (progn (forward-sexp -1)
 560                                         (while (looking-at "\\s'")
 561                                           (forward-char 1))
 562                                         (point))))
 563       nil)))
 564
 565 ;; Read a tag name from the minibuffer with defaulting and completion.
 566 (defun find-tag-tag (string)
 567   (let* ((default (funcall (or find-tag-default-function
 568                                (get major-mode 'find-tag-default-function)
 569                                'find-tag-default)))
 570          (spec (completing-read (if default
 571                                     (format "%s(default %s) " string default)
 572                                   string)
 573                                 'tags-complete-tag)))
 574     (if (equal spec "")
 575         (or default (error "There is no default tag"))
 576       spec)))
 577
 578 (defvar last-tag nil
 579   "Last tag found by \\[find-tag].")
 580
 581 ;;;###autoload
 582 (defun find-tag-noselect (tagname &optional next-p regexp-p)
 583   "Find tag (in current tags table) whose name contains TAGNAME.
 584 Returns the buffer containing the tag's definition and moves its point there,
 585 but does not select the buffer.
 586 The default for TAGNAME is the expression in the buffer near point.
 587
 588 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 589 for another tag that matches the last tagname or regexp used.  When there
 590 are multiple matches for a tag, more exact matches are found first.
 591
 592 If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
 593
 594 See documentation of variable `tags-file-name'."
 595   (interactive (if current-prefix-arg
 596                    '(nil t)
 597                  (list (find-tag-tag "Find tag: "))))
 598   ;; Save the current buffer's value of `find-tag-hook' before selecting the
 599   ;; tags table buffer.
 600   (let ((local-find-tag-hook find-tag-hook))
 601     (if next-p
 602         ;; Find the same table we last used.
 603         (visit-tags-table-buffer 'same)
 604       ;; Pick a table to use.
 605       (visit-tags-table-buffer)
 606       ;; Record TAGNAME for a future call with NEXT-P non-nil.
 607       (setq last-tag tagname))
 608     (prog1
 609         ;; find-tag-in-order does the real work.
 610         (find-tag-in-order (if next-p last-tag tagname)
 611                            (if regexp-p
 612                                find-tag-regexp-search-function
 613                              find-tag-search-function)
 614                            (if regexp-p
 615                                find-tag-regexp-tag-order
 616                              find-tag-tag-order)
 617                            (if regexp-p
 618                                find-tag-regexp-next-line-after-failure-p
 619                              find-tag-next-line-after-failure-p)
 620                            (if regexp-p "matching" "containing")
 621                            (not next-p))
 622       (run-hooks 'local-find-tag-hook))))
 623
 624 ;;;###autoload
 625 (defun find-tag (tagname &optional next-p)
 626   "Find tag (in current tags table) whose name contains TAGNAME.
 627 Select the buffer containing the tag's definition, and move point there.
 628 The default for TAGNAME is the expression in the buffer around or before point.
 629
 630 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 631 for another tag that matches the last tagname used.  When there are
 632 multiple matches, more exact matches are found first.
 633
 634 See documentation of variable `tags-file-name'."
 635   (interactive (if current-prefix-arg
 636                    '(nil t)
 637                  (list (find-tag-tag "Find tag: "))))
 638   (switch-to-buffer (find-tag-noselect tagname next-p)))
 639 ;;;###autoload (define-key esc-map "." 'find-tag)
 640
 641 ;;;###autoload
 642 (defun find-tag-other-window (tagname &optional next-p)
 643   "Find tag (in current tags table) whose name contains TAGNAME.
 644 Select the buffer containing the tag's definition
 645 in another window, and move point there.
 646 The default for TAGNAME is the expression in the buffer around or before point.
 647
 648 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 649 for another tag that matches the last tagname used.  When there are
 650 multiple matches, more exact matches are found first.
 651
 652 See documentation of variable `tags-file-name'."
 653   (interactive (if current-prefix-arg
 654                    '(nil t)
 655                  (list (find-tag-tag "Find tag other window: "))))
 656   ;; This hair is to deal with the case where the tag is found in the
 657   ;; selected window's buffer; without the hair, point is moved in both
 658   ;; windows.  To prevent this, we save the selected window's point before
 659   ;; doing find-tag-noselect, and restore it after.
 660   (let* ((window-point (window-point (selected-window)))
 661          (tagbuf (find-tag-noselect tagname next-p)))
 662     (set-window-point (prog1
 663                           (selected-window)
 664                         (switch-to-buffer-other-window tagbuf))
 665                       window-point)))
 666 ;;;###autoload (define-key ctl-x-4-map "." 'find-tag-other-window)
 667
 668 ;;;###autoload
 669 (defun find-tag-other-frame (tagname &optional next-p)
 670   "Find tag (in current tag table) whose name contains TAGNAME.
 671  Selects the buffer that the tag is contained in in another frame
 672 and puts point at its definition.
 673  If TAGNAME is a null string, the expression in the buffer
 674 around or before point is used as the tag name.
 675  If second arg NEXT-P is non-nil (interactively, with prefix arg),
 676 searches for the next tag in the tag table
 677 that matches the tagname used in the previous find-tag.
 678
 679 See documentation of variable `tags-file-name'."
 680   (interactive (if current-prefix-arg
 681                    '(nil t)
 682                  (list (find-tag-tag "Find tag other window: "))))
 683   (let ((pop-up-frames t))
 684     (find-tag-other-window tagname next-p)))
 685 ;;;###autoload (define-key ctl-x-5-map "." 'find-tag-other-frame)
 686
 687 ;;;###autoload
 688 (defun find-tag-regexp (regexp &optional next-p other-window)
 689   "Find tag (in current tags table) whose name matches REGEXP.
 690 Select the buffer containing the tag's definition and move point there.
 691
 692 If second arg NEXT-P is non-nil (interactively, with prefix arg), search
 693 for another tag that matches the last tagname used.
 694
 695 If third arg OTHER-WINDOW is non-nil, select the buffer in another window.
 696
 697 See documentation of variable `tags-file-name'."
 698   (interactive (if current-prefix-arg
 699                    '(nil t)
 700                  (list (read-string "Find tag regexp: "))))
 701   (funcall (if other-window 'switch-to-buffer-other-window 'switch-to-buffer)
 702            (find-tag-noselect regexp next-p t)))
 703 \f
 704 ;; Internal tag finding function.
 705
 706 ;; PATTERN is a string to pass to second arg SEARCH-FORWARD-FUNC, and to
 707 ;; any member of the function list ORDER (third arg).  If ORDER is nil,
 708 ;; use saved state to continue a previous search.
 709
 710 ;; Fourth arg MATCHING is a string, an English '-ing' word, to be used in
 711 ;; an error message.
 712
 713 ;; Fifth arg NEXT-LINE-AFTER-FAILURE-P is non-nil if after a failed match,
 714 ;; point should be moved to the next line.
 715
 716 ;; Algorithm is as follows.  For each qualifier-func in ORDER, go to
 717 ;; beginning of tags file, and perform inner loop: for each naive match for
 718 ;; PATTERN found using SEARCH-FORWARD-FUNC, qualify the naive match using
 719 ;; qualifier-func.  If it qualifies, go to the specified line in the
 720 ;; specified source file and return.  Qualified matches are remembered to
 721 ;; avoid repetition.  State is saved so that the loop can be continued.
 722
 723 (defun find-tag-in-order (pattern
 724                           search-forward-func
 725                           order
 726                           next-line-after-failure-p
 727                           matching
 728                           first-search)
 729   (let (file                            ;name of file containing tag
 730         tag-info                        ;where to find the tag in FILE
 731         tags-table-file                 ;name of tags file
 732         (first-table t)
 733         (tag-order order)
 734         goto-func
 735         )
 736     (save-excursion
 737       (or first-search                  ;find-tag-noselect has already done it.
 738           (visit-tags-table-buffer 'same))
 739
 740       ;; Get a qualified match.
 741       (catch 'qualified-match-found
 742
 743         ;; Iterate over the list of tags tables.
 744         (while (or first-table
 745                    (visit-tags-table-buffer t))
 746
 747           (if first-search
 748               (setq tag-lines-already-matched nil))
 749
 750           (and first-search first-table
 751                ;; Start at beginning of tags file.
 752                (goto-char (point-min)))
 753           (setq first-table nil)
 754
 755           (setq tags-table-file buffer-file-name)
 756           ;; Iterate over the list of ordering predicates.
 757           (while order
 758             (while (funcall search-forward-func pattern nil t)
 759               ;; Naive match found.  Qualify the match.
 760               (and (funcall (car order) pattern)
 761                    ;; Make sure it is not a previous qualified match.
 762                    ;; Use of `memq' depends on numbers being eq.
 763                    (not (memq (save-excursion (beginning-of-line) (point))
 764                               tag-lines-already-matched))
 765                    (throw 'qualified-match-found nil))
 766               (if next-line-after-failure-p
 767                   (forward-line 1)))
 768             ;; Try the next flavor of match.
 769             (setq order (cdr order))
 770             (goto-char (point-min)))
 771           (setq order tag-order))
 772         ;; We throw out on match, so only get here if there were no matches.
 773         (error "No %stags %s %s" (if first-search "" "more ")
 774                matching pattern))
 775
 776       ;; Found a tag; extract location info.
 777       (beginning-of-line)
 778       (setq tag-lines-already-matched (cons (point)
 779                                             tag-lines-already-matched))
 780       ;; Expand the filename, using the tags table buffer's default-directory.
 781       (setq file (expand-file-name (file-of-tag))
 782             tag-info (funcall snarf-tag-function))
 783
 784       ;; Get the local value in the tags table buffer before switching buffers.
 785       (setq goto-func goto-tag-location-function)
 786
 787       ;; Find the right line in the specified file.
 788       (set-buffer (find-file-noselect file))
 789       (widen)
 790       (push-mark)
 791       (funcall goto-func tag-info)
 792
 793       ;; Give this buffer a local value of tags-file-name.
 794       ;; The next time visit-tags-table-buffer is called,
 795       ;; it will use the same tags table that found a match in this buffer.
 796       (make-local-variable 'tags-file-name)
 797       (setq tags-file-name tags-table-file)
 798
 799       ;; Return the buffer where the tag was found.
 800       (current-buffer))))
 801 \f
 802 ;; `etags' TAGS file format support.
 803
 804 ;; If the current buffer is a valid etags TAGS file, give it local values of
 805 ;; the tags table format variables, and return non-nil.
 806 (defun etags-recognize-tags-table ()
 807   (and (etags-verify-tags-table)
 808        ;; It is annoying to flash messages on the screen briefly,
 809        ;; and this message is not useful.  -- rms
 810        ;; (message "%s is an `etags' TAGS file" buffer-file-name)
 811        (mapcar (function (lambda (elt)
 812                            (set (make-local-variable (car elt)) (cdr elt))))
 813                '((file-of-tag-function . etags-file-of-tag)
 814                  (tags-table-files-function . etags-tags-table-files)
 815                  (tags-completion-table-function . etags-tags-completion-table)
 816                  (snarf-tag-function . etags-snarf-tag)
 817                  (goto-tag-location-function . etags-goto-tag-location)
 818                  (find-tag-regexp-search-function . re-search-forward)
 819                  (find-tag-regexp-tag-order . (tag-re-match-p))
 820                  (find-tag-regexp-next-line-after-failuire-p . t)
 821                  (find-tag-search-function . search-forward)
 822                  (find-tag-tag-order . (tag-exact-match-p tag-word-match-p
 823                                                           tag-any-match-p))
 824                  (find-tag-next-line-after-failure-p . nil)
 825                  (list-tags-function . etags-list-tags)
 826                  (tags-apropos-function . etags-tags-apropos)
 827                  (tags-included-tables-function . etags-tags-included-tables)
 828                  (verify-tags-table-function . etags-verify-tags-table)
 829                  ))))
 830
 831 ;; Return non-nil iff the current buffer is a valid etags TAGS file.
 832 (defun etags-verify-tags-table ()
 833   ;; Use eq instead of = in case char-after returns nil.
 834   (eq (char-after 1) ?\f))
 835
 836 (defun etags-file-of-tag ()
 837   (save-excursion
 838     (search-backward "\f\n")
 839     (forward-char 2)
 840     (buffer-substring (point)
 841                       (progn (skip-chars-forward "^,") (point)))))
 842
 843 (defun etags-tags-completion-table ()
 844   (let ((table (make-vector 511 0)))
 845     (save-excursion
 846       (goto-char (point-min))
 847       (while (search-forward "\177" nil t)
 848         ;; Handle multiple \177's on a line.
 849         (save-excursion
 850           (skip-chars-backward "^-A-Za-z0-9_$\n") ;sym syntax? XXX
 851           (or (bolp)
 852               (intern (buffer-substring
 853                        (point)
 854                        (progn
 855                          (skip-chars-backward "-A-Za-z0-9_$")
 856                          ;; ??? New
 857                          ;; `::' in the middle of a C++ tag.
 858                          (and (= (preceding-char) ?:)
 859                               (= (char-after (- (point) 2)) ?:)
 860                               (progn
 861                                 (backward-char 2)
 862                                 (skip-chars-backward
 863                                  "-A-Za-z0-9_$")))
 864                          (point)))
 865                       table)))))
 866     table))
 867
 868 (defun etags-snarf-tag ()
 869   (let (tag-text startpos)
 870     (search-forward "\177")
 871     (setq tag-text (buffer-substring (1- (point))
 872                                      (save-excursion (beginning-of-line)
 873                                                      (point))))
 874     (search-forward ",")
 875     (setq startpos (string-to-int (buffer-substring
 876                                    (point)
 877                                    (progn (skip-chars-forward "0-9")
 878                                           (point)))))
 879     ;; Leave point on the next line of the tags file.
 880     (forward-line 1)
 881     (cons tag-text startpos)))
 882
 883 (defun etags-goto-tag-location (tag-info)
 884   (let ((startpos (cdr tag-info))
 885         ;; This constant is 1/2 the initial search window.
 886         ;; There is no sense in making it too small,
 887         ;; since just going around the loop once probably
 888         ;; costs about as much as searching 2000 chars.
 889         (offset 1000)
 890         (found nil)
 891         (pat (concat "^" (regexp-quote (car tag-info)))))
 892     (or startpos
 893         (setq startpos (point-min)))
 894     (while (and (not found)
 895                 (progn
 896                   (goto-char (- startpos offset))
 897                   (not (bobp))))
 898       (setq found
 899             (re-search-forward pat (+ startpos offset) t)
 900             offset (* 3 offset)))       ; expand search window
 901     (or found
 902         (re-search-forward pat nil t)
 903         (error "`%s' not found in %s; time to rerun etags"
 904                pat buffer-file-name)))
 905   (beginning-of-line))
 906
 907 (defun etags-list-tags (file)
 908   (goto-char 1)
 909   (if (not (search-forward (concat "\f\n" file ",") nil t))
 910       nil
 911     (forward-line 1)
 912     (while (not (or (eobp) (looking-at "\f")))
 913       (princ (buffer-substring (point)
 914                                (progn (skip-chars-forward "^\177")
 915                                       (point))))
 916       (terpri)
 917       (forward-line 1))))
 918
 919 (defun etags-tags-apropos (string)
 920   (goto-char 1)
 921   (while (re-search-forward string nil t)
 922     (beginning-of-line)
 923     (princ (buffer-substring (point)
 924                              (progn (skip-chars-forward "^\177")
 925                                     (point))))
 926     (terpri)
 927     (forward-line 1)))
 928
 929 (defun etags-tags-table-files ()
 930   (let ((files nil)
 931         beg)
 932     (goto-char (point-min))
 933     (while (search-forward "\f\n" nil t)
 934       (setq beg (point))
 935       (skip-chars-forward "^,\n")
 936       (or (looking-at ",include$")
 937           ;; Expand in the default-directory of the tags table buffer.
 938           (setq files (cons (expand-file-name (buffer-substring beg (point)))
 939                             files))))
 940     (nreverse files)))
 941
 942 (defun etags-tags-included-tables ()
 943   (let ((files nil)
 944         beg)
 945     (goto-char (point-min))
 946     (while (search-forward "\f\n" nil t)
 947       (setq beg (point))
 948       (skip-chars-forward "^,\n")
 949       (if (looking-at ",include$")
 950           ;; Expand in the default-directory of the tags table buffer.
 951           (setq files (cons (expand-file-name (buffer-substring beg (point)))
 952                             files))))
 953     (nreverse files)))
 954 \f
 955 ;; Empty tags file support.
 956
 957 ;; Recognize an empty file and give it local values of the tags table format
 958 ;; variables which do nothing.
 959 (defun recognize-empty-tags-table ()
 960   (and (zerop (buffer-size))
 961        (mapcar (function (lambda (sym)
 962                            (set (make-local-variable sym) 'ignore)))
 963                '(tags-table-files-function
 964                  tags-completion-table-function
 965                  find-tag-regexp-search-function
 966                  find-tag-search-function
 967                  tags-apropos-function
 968                  tags-included-tables-function))
 969        (set (make-local-variable 'verify-tags-table-function)
 970             (function (lambda ()
 971                         (zerop (buffer-size)))))))
 972 \f
 973 ;;; Match qualifier functions for tagnames.
 974 ;;; XXX these functions assume etags file format.
 975
 976 ;; This might be a neat idea, but it's too hairy at the moment.
 977 ;;(defmacro tags-with-syntax (&rest body)
 978 ;;  (` (let ((current (current-buffer))
 979 ;;         (otable (syntax-table))
 980 ;;         (buffer (find-file-noselect (file-of-tag)))
 981 ;;         table)
 982 ;;       (unwind-protect
 983 ;;         (progn
 984 ;;           (set-buffer buffer)
 985 ;;           (setq table (syntax-table))
 986 ;;           (set-buffer current)
 987 ;;           (set-syntax-table table)
 988 ;;           (,@ body))
 989 ;;       (set-syntax-table otable)))))
 990 ;;(put 'tags-with-syntax 'edebug-form-spec '(&rest form))
 991
 992 ;; t if point is at a tag line that matches TAG "exactly".
 993 ;; point should be just after a string that matches TAG.
 994 (defun tag-exact-match-p (tag)
 995   (and (looking-at "\\Sw.*\177") (looking-at "\\S_.*\177") ;not a symbol char
 996        (save-excursion
 997          (backward-char (1+ (length tag)))
 998          (and (looking-at "\\Sw") (looking-at "\\S_")))))
 999
1000 ;; t if point is at a tag line that matches TAG as a word.
1001 ;; point should be just after a string that matches TAG.
1002 (defun tag-word-match-p (tag)
1003   (and (looking-at "\\b.*\177")
1004        (save-excursion (backward-char (1+ (length tag)))
1005                        (looking-at "\\b"))))
1006
1007 ;; t if point is in a tag line with a tag containing TAG as a substring.
1008 (defun tag-any-match-p (tag)
1009   (looking-at ".*\177"))
1010
1011 ;; t if point is at a tag line that matches RE as a regexp.
1012 (defun tag-re-match-p (re)
1013   (save-excursion
1014     (beginning-of-line)
1015     (let ((bol (point)))
1016       (and (search-forward "\177" (save-excursion (end-of-line) (point)) t)
1017            (re-search-backward re bol t)))))
1018 \f
1019 ;;;###autoload
1020 (defun next-file (&optional initialize novisit)
1021   "Select next file among files in current tags table.
1022 Non-nil first argument (prefix arg, if interactive)
1023 initializes to the beginning of the list of files in the tags table.
1024
1025 Non-nil second argument NOVISIT means use a temporary buffer
1026  to save time and avoid uninteresting warnings.
1027
1028 Value is nil if the file was already visited;
1029 if the file was newly read in, the value is the filename."
1030   (interactive "P")
1031   (and initialize
1032        (save-excursion
1033          ;; Visit the tags table buffer to get its list of files.
1034          (visit-tags-table-buffer)
1035          (setq next-file-list (tags-table-files))))
1036   (or next-file-list
1037       (save-excursion
1038         ;; Get the files from the next tags table.
1039         ;; When doing (visit-tags-table-buffer t),
1040         ;; the tags table buffer must be current.
1041         (if (and (visit-tags-table-buffer 'same)
1042                  (visit-tags-table-buffer t))
1043             (setq next-file-list (tags-table-files))
1044           (and novisit
1045                (get-buffer " *next-file*")
1046                (kill-buffer " *next-file*"))
1047           (error "All files processed."))))
1048   (let ((new (not (get-file-buffer (car next-file-list)))))
1049     (if (not (and new novisit))
1050         (set-buffer (find-file-noselect (car next-file-list) novisit))
1051       ;; Like find-file, but avoids random warning messages.
1052       (set-buffer (get-buffer-create " *next-file*"))
1053       (kill-all-local-variables)
1054       (erase-buffer)
1055       (setq new (car next-file-list))
1056       (insert-file-contents new nil))
1057     (setq next-file-list (cdr next-file-list))
1058     new))
1059
1060 (defvar tags-loop-operate nil
1061   "Form for `tags-loop-continue' to eval to change one file.")
1062
1063 (defvar tags-loop-scan nil
1064   "Form for `tags-loop-continue' to eval to scan one file.
1065 If it returns non-nil, this file needs processing by evalling
1066 \`tags-loop-operate'.  Otherwise, move on to the next file.")
1067
1068 ;;;###autoload
1069 (defun tags-loop-continue (&optional first-time)
1070   "Continue last \\[tags-search] or \\[tags-query-replace] command.
1071 Used noninteractively with non-nil argument to begin such a command.
1072 Two variables control the processing we do on each file:
1073 the value of `tags-loop-scan' is a form to be executed on each file
1074 to see if it is interesting (it returns non-nil if so)
1075 and `tags-loop-operate' is a form to execute to operate on an interesting file
1076 If the latter returns non-nil, we exit; otherwise we scan the next file."
1077   (interactive)
1078   (let (new
1079         (messaged nil))
1080     (while
1081         (progn
1082           ;; Scan files quickly for the first or next interesting one.
1083           (while (or first-time
1084                      (save-restriction
1085                        (widen)
1086                        (not (eval tags-loop-scan))))
1087             (setq new (next-file first-time t))
1088             ;; If NEW is non-nil, we got a temp buffer,
1089             ;; and NEW is the file name.
1090             (if (or messaged
1091                     (and (not first-time)
1092                          (> baud-rate search-slow-speed)
1093                          (setq messaged t)))
1094                 (message "Scanning file %s..." (or new buffer-file-name)))
1095             (setq first-time nil)
1096             (goto-char (point-min)))
1097
1098           ;; If we visited it in a temp buffer, visit it now for real.
1099           (if new
1100               (let ((pos (point)))
1101                 (erase-buffer)
1102                 (set-buffer (find-file-noselect new))
1103                 (widen)
1104                 (goto-char pos)))
1105
1106           (switch-to-buffer (current-buffer))
1107
1108           ;; Now operate on the file.
1109           ;; If value is non-nil, continue to scan the next file.
1110           (eval tags-loop-operate)))
1111     (and messaged
1112          (null tags-loop-operate)
1113          (message "Scanning file %s...found" buffer-file-name))))
1114 ;;;###autoload (define-key esc-map "," 'tags-loop-continue)
1115
1116 ;;;###autoload
1117 (defun tags-search (regexp)
1118   "Search through all files listed in tags table for match for REGEXP.
1119 Stops when a match is found.
1120 To continue searching for next match, use command \\[tags-loop-continue].
1121
1122 See documentation of variable `tags-file-name'."
1123   (interactive "sTags search (regexp): ")
1124   (if (and (equal regexp "")
1125            (eq (car tags-loop-scan) 're-search-forward)
1126            (null tags-loop-operate))
1127       ;; Continue last tags-search as if by M-,.
1128       (tags-loop-continue nil)
1129     (setq tags-loop-scan
1130           (list 're-search-forward regexp nil t)
1131           tags-loop-operate nil)
1132     (tags-loop-continue t)))
1133
1134 ;;;###autoload
1135 (defun tags-query-replace (from to &optional delimited)
1136   "Query-replace-regexp FROM with TO through all files listed in tags table.
1137 Third arg DELIMITED (prefix arg) means replace only word-delimited matches.
1138 If you exit (\\[keyboard-quit] or ESC), you can resume the query-replace
1139 with the command \\[tags-loop-continue].
1140
1141 See documentation of variable `tags-file-name'."
1142   (interactive
1143    "sTags query replace (regexp): \nsTags query replace %s by: \nP")
1144   (setq tags-loop-scan (list 'prog1
1145                              (list 'if (list 're-search-forward form nil t)
1146                                    ;; When we find a match, move back
1147                                    ;; to the beginning of it so perform-replace
1148                                    ;; will see it.
1149                                    '(goto-char (match-beginning 0))))
1150         tags-loop-operate (list 'perform-replace from to t t delimited))
1151   (tags-loop-continue t))
1152 \f
1153 ;;;###autoload
1154 (defun list-tags (file)
1155   "Display list of tags in file FILE.
1156 FILE should not contain a directory specification
1157 unless it has one in the tags table."
1158   (interactive (list (completing-read "List tags in file: " nil
1159                                       'tags-table-files t nil)))
1160   (with-output-to-temp-buffer "*Tags List*"
1161     (princ "Tags in file ")
1162     (princ file)
1163     (terpri)
1164     (save-excursion
1165       (let ((first-time t)
1166             (gotany nil))
1167         (while (visit-tags-table-buffer (not first-time))
1168           (if (funcall list-tags-function file)
1169               (setq gotany t)))
1170         (or gotany
1171             (error "File %s not in current tags tables"))))))
1172
1173 ;;;###autoload
1174 (defun tags-apropos (regexp)
1175   "Display list of all tags in tags table REGEXP matches."
1176   (interactive "sTags apropos (regexp): ")
1177   (with-output-to-temp-buffer "*Tags List*"
1178     (princ "Tags matching regexp ")
1179     (prin1 regexp)
1180     (terpri)
1181     (save-excursion
1182       (let ((first-time t))
1183         (while (visit-tags-table-buffer (not first-time))
1184           (setq first-time nil)
1185           (funcall tags-apropos-function regexp))))))
1186 \f
1187 ;;; XXX Kludge interface.
1188
1189 ;; XXX If a file is in multiple tables, selection may get the wrong one.
1190 ;;;###autoload
1191 (defun select-tags-table ()
1192   "Select a tags table file from a menu of those you have already used.
1193 The list of tags tables to select from is stored in `tags-table-file-list';
1194 see the doc of that variable if you want to add names to the list."
1195   (interactive)
1196   (pop-to-buffer "*Tags Table List*")
1197   (setq buffer-read-only nil)
1198   (erase-buffer)
1199   (setq selective-display t
1200         selective-display-ellipses nil)
1201   (let ((set-list tags-table-set-list)
1202         (desired-point nil))
1203     (if tags-table-list
1204         (progn
1205           (setq desired-point (point-marker))
1206           (princ tags-table-list (current-buffer))
1207           (insert "\C-m")
1208           (prin1 (car tags-table-list) (current-buffer)) ;invisible
1209           (insert "\n")))
1210     (while set-list
1211       (if (eq (car set-list) tags-table-list)
1212           ;; Already printed it.
1213           ()
1214         (princ (car set-list) (current-buffer))
1215         (insert "\C-m")
1216         (prin1 (car (car set-list)) (current-buffer)) ;invisible
1217         (insert "\n"))
1218       (setq set-list (cdr set-list)))
1219     (if tags-file-name
1220         (progn
1221           (or desired-point
1222               (setq desired-point (point-marker)))
1223           (insert tags-file-name "\C-m")
1224           (prin1 tags-file-name (current-buffer)) ;invisible
1225           (insert "\n")))
1226     (setq set-list (delete tags-file-name
1227                            (apply 'nconc (cons tags-table-list
1228                                                (mapcar 'copy-sequence
1229                                                        tags-table-set-list)))))
1230     (while set-list
1231       (insert (car set-list) "\C-m")
1232       (prin1 (car set-list) (current-buffer)) ;invisible
1233       (insert "\n")
1234       (setq set-list (delete (car set-list) set-list)))
1235     (goto-char 1)
1236     (insert-before-markers
1237      "Type `t' to select a tags table or set of tags tables:\n\n")
1238     (if desired-point
1239         (goto-char desired-point))
1240     (set-window-start (selected-window) 1 t))
1241   (set-buffer-modified-p nil)
1242   (setq buffer-read-only t
1243         mode-name "Select Tags Table")
1244   (let ((map (make-sparse-keymap)))
1245     (define-key map "t" 'select-tags-table-select)
1246     (define-key map " " 'next-line)
1247     (define-key map "\^?" 'previous-line)
1248     (define-key map "n" 'next-line)
1249     (define-key map "p" 'previous-line)
1250     (define-key map "q" 'select-tags-table-quit)
1251     (use-local-map map)))
1252
1253 (defun select-tags-table-select ()
1254   "Select the tags table named on this line."
1255   (interactive)
1256   (search-forward "\C-m")
1257   (let ((name (read (current-buffer))))
1258     (visit-tags-table name)
1259     (select-tags-table-quit)
1260     (message "Tags table now %s" name)))
1261
1262 (defun select-tags-table-quit ()
1263   "Kill the buffer and delete the selected window."
1264   (interactive)
1265   (kill-buffer (current-buffer))
1266   (or (one-window-p)
1267       (delete-window)))
1268 \f
1269 ;;;###autoload
1270 (defun complete-tag ()
1271   "Perform tags completion on the text around point.
1272 Completes to the set of names listed in the current tags table.
1273 The string to complete is chosen in the same way as the default
1274 for \\[find-tag] (which see)."
1275   (interactive)
1276   (or tags-table-list
1277       tags-file-name
1278       (error (substitute-command-keys
1279               "No tags table loaded.  Try \\[visit-tags-table].")))
1280   (let ((pattern (funcall (or find-tag-default-function
1281                               (get major-mode 'find-tag-default-function)
1282                               'find-tag-default)))
1283         beg
1284         completion)
1285     (or pattern
1286         (error "Nothing to complete"))
1287     (search-backward pattern)
1288     (setq beg (point))
1289     (forward-char (length pattern))
1290     (setq completion (try-completion pattern 'tags-complete-tag nil))
1291     (cond ((eq completion t))
1292           ((null completion)
1293            (message "Can't find completion for \"%s\"" pattern)
1294            (ding))
1295           ((not (string= pattern completion))
1296            (delete-region beg (point))
1297            (insert completion))
1298           (t
1299            (message "Making completion list...")
1300            (with-output-to-temp-buffer " *Completions*"
1301              (display-completion-list
1302               (all-completions pattern 'tags-complete-tag nil)))
1303            (message "Making completion list...%s" "done")))))
1304
1305 ;;;###autoload (define-key esc-map "\t" 'complete-tag)
1306 \f
1307 (provide 'etags)
1308
1309 ;;; etags.el ends here