1;;; etags.el --- etags facility for Emacs
2
3;; Copyright (C) 1985, 1986, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1998,
4;;               2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
5;;	Free Software Foundation, Inc.
6
7;; Author: Roland McGrath <roland@gnu.org>
8;; Maintainer: FSF
9;; Keywords: tools
10
11;; This file is part of GNU Emacs.
12
13;; GNU Emacs is free software; you can redistribute it and/or modify
14;; it under the terms of the GNU General Public License as published by
15;; the Free Software Foundation; either version 2, or (at your option)
16;; any later version.
17
18;; GNU Emacs is distributed in the hope that it will be useful,
19;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21;; GNU General Public License for more details.
22
23;; You should have received a copy of the GNU General Public License
24;; along with GNU Emacs; see the file COPYING.  If not, write to the
25;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
26;; Boston, MA 02110-1301, USA.
27
28;;; Commentary:
29
30;;; Code:
31
32(require 'ring)
33(require 'button)
34
35;;;###autoload
36(defvar tags-file-name nil
37  "*File name of tags table.
38To switch to a new tags table, setting this variable is sufficient.
39If you set this variable, do not also set `tags-table-list'.
40Use the `etags' program to make a tags table file.")
41;; Make M-x set-variable tags-file-name like M-x visit-tags-table.
42;;;###autoload (put 'tags-file-name 'variable-interactive "fVisit tags table: ")
43
44(defgroup etags nil "Tags tables."
45  :group 'tools)
46
47;;;###autoload
48(defcustom tags-case-fold-search 'default
49  "*Whether tags operations should be case-sensitive.
50A value of t means case-insensitive, a value of nil means case-sensitive.
51Any other value means use the setting of `case-fold-search'."
52  :group 'etags
53  :type '(choice (const :tag "Case-sensitive" nil)
54		 (const :tag "Case-insensitive" t)
55		 (other :tag "Use default" default))
56  :version "21.1")
57
58;;;###autoload
59;; Use `visit-tags-table-buffer' to cycle through tags tables in this list.
60(defcustom tags-table-list nil
61  "*List of file names of tags tables to search.
62An element that is a directory means the file \"TAGS\" in that directory.
63To switch to a new list of tags tables, setting this variable is sufficient.
64If you set this variable, do not also set `tags-file-name'.
65Use the `etags' program to make a tags table file."
66  :group 'etags
67  :type '(repeat file))
68
69;;;###autoload
70(defcustom tags-compression-info-list '("" ".Z" ".bz2" ".gz" ".tgz")
71  "*List of extensions tried by etags when jka-compr is used.
72An empty string means search the non-compressed file.
73These extensions will be tried only if jka-compr was activated
74\(i.e. via customize of `auto-compression-mode' or by calling the function
75`auto-compression-mode')."
76  :type  '(repeat string)
77  :group 'etags)
78
79;; !!! tags-compression-info-list should probably be replaced by access
80;; to directory list and matching jka-compr-compression-info-list. Currently,
81;; this implementation forces each modification of
82;; jka-compr-compression-info-list to be reflected in this var.
83;; An alternative could be to say that introducing a special
84;; element in this list (e.g. t) means : try at this point
85;; using directory listing and regexp matching using
86;; jka-compr-compression-info-list.
87
88
89;;;###autoload
90(defcustom tags-add-tables 'ask-user
91  "*Control whether to add a new tags table to the current list.
92t means do; nil means don't (always start a new list).
93Any other value means ask the user whether to add a new tags table
94to the current list (as opposed to starting a new list)."
95  :group 'etags
96  :type '(choice (const :tag "Do" t)
97		 (const :tag "Don't" nil)
98		 (other :tag "Ask" ask-user)))
99
100(defcustom tags-revert-without-query nil
101  "*Non-nil means reread a TAGS table without querying, if it has changed."
102  :group 'etags
103  :type 'boolean)
104
105(defvar tags-table-computed-list nil
106  "List of tags tables to search, computed from `tags-table-list'.
107This includes tables implicitly included by other tables.  The list is not
108always complete: the included tables of a table are not known until that
109table is read into core.  An element that is t is a placeholder
110indicating that the preceding element is a table that has not been read
111into core and might contain included tables to search.
112See `tags-table-check-computed-list'.")
113
114(defvar tags-table-computed-list-for nil
115  "Value of `tags-table-list' that `tags-table-computed-list' corresponds to.
116If `tags-table-list' changes, `tags-table-computed-list' is thrown away and
117recomputed; see `tags-table-check-computed-list'.")
118
119(defvar tags-table-list-pointer nil
120  "Pointer into `tags-table-computed-list' for the current state of searching.
121Use `visit-tags-table-buffer' to cycle through tags tables in this list.")
122
123(defvar tags-table-list-started-at nil
124  "Pointer into `tags-table-computed-list', where the current search started.")
125
126(defvar tags-table-set-list nil
127  "List of sets of tags table which have been used together in the past.
128Each element is a list of strings which are file names.")
129
130;;;###autoload
131(defcustom find-tag-hook nil
132  "*Hook to be run by \\[find-tag] after finding a tag.  See `run-hooks'.
133The value in the buffer in which \\[find-tag] is done is used,
134not the value in the buffer \\[find-tag] goes to."
135  :group 'etags
136  :type 'hook)
137
138;;;###autoload
139(defcustom find-tag-default-function nil
140  "*A function of no arguments used by \\[find-tag] to pick a default tag.
141If nil, and the symbol that is the value of `major-mode'
142has a `find-tag-default-function' property (see `put'), that is used.
143Otherwise, `find-tag-default' is used."
144  :group 'etags
145  :type '(choice (const nil) function))
146
147(defcustom find-tag-marker-ring-length 16
148  "*Length of marker rings `find-tag-marker-ring' and `tags-location-ring'."
149  :group 'etags
150  :type 'integer
151  :version "20.3")
152
153(defcustom tags-tag-face 'default
154  "*Face for tags in the output of `tags-apropos'."
155  :group 'etags
156  :type 'face
157  :version "21.1")
158
159(defcustom tags-apropos-verbose nil
160  "If non-nil, print the name of the tags file in the *Tags List* buffer."
161  :group 'etags
162  :type 'boolean
163  :version "21.1")
164
165(defcustom tags-apropos-additional-actions nil
166  "Specify additional actions for `tags-apropos'.
167
168If non-nil, value should be a list of triples (TITLE FUNCTION
169TO-SEARCH).  For each triple, `tags-apropos' processes TO-SEARCH and
170lists tags from it.  TO-SEARCH should be an alist, obarray, or symbol.
171If it is a symbol, the symbol's value is used.
172TITLE, a string, is a title used to label the additional list of tags.
173FUNCTION is a function to call when a symbol is selected in the
174*Tags List* buffer.  It will be called with one argument SYMBOL which
175is the symbol being selected.
176
177Example value:
178
179  '((\"Emacs Lisp\" Info-goto-emacs-command-node obarray)
180    (\"Common Lisp\" common-lisp-hyperspec common-lisp-hyperspec-obarray)
181    (\"SCWM\" scwm-documentation scwm-obarray))"
182  :group 'etags
183  :type '(repeat (list (string :tag "Title")
184		       function
185		       (sexp :tag "Tags to search")))
186  :version "21.1")
187
188(defvar find-tag-marker-ring (make-ring find-tag-marker-ring-length)
189  "Ring of markers which are locations from which \\[find-tag] was invoked.")
190
191(defvar default-tags-table-function nil
192  "If non-nil, a function to choose a default tags file for a buffer.
193This function receives no arguments and should return the default
194tags table file to use for the current buffer.")
195
196(defvar tags-location-ring (make-ring find-tag-marker-ring-length)
197  "Ring of markers which are locations visited by \\[find-tag].
198Pop back to the last location with \\[negative-argument] \\[find-tag].")
199
200;; Tags table state.
201;; These variables are local in tags table buffers.
202
203(defvar tags-table-files nil
204  "List of file names covered by current tags table.
205nil means it has not yet been computed; use `tags-table-files' to do so.")
206
207(defvar tags-completion-table nil
208  "Obarray of tag names defined in current tags table.")
209
210(defvar tags-included-tables nil
211  "List of tags tables included by the current tags table.")
212
213(defvar next-file-list nil
214  "List of files for \\[next-file] to process.")
215
216;; Hooks for file formats.
217
218(defvar tags-table-format-functions '(etags-recognize-tags-table
219				      tags-recognize-empty-tags-table)
220  "Hook to be called in a tags table buffer to identify the type of tags table.
221The functions are called in order, with no arguments,
222until one returns non-nil.  The function should make buffer-local bindings
223of the format-parsing tags function variables if successful.")
224
225(defvar file-of-tag-function nil
226  "Function to do the work of `file-of-tag' (which see).
227One optional argument, a boolean specifying to return complete path (nil) or
228relative path (non-nil).")
229(defvar tags-table-files-function nil
230  "Function to do the work of `tags-table-files' (which see).")
231(defvar tags-completion-table-function nil
232  "Function to build the `tags-completion-table'.")
233(defvar snarf-tag-function nil
234  "Function to get info about a matched tag for `goto-tag-location-function'.
235One optional argument, specifying to use explicit tag (non-nil) or not (nil).
236The default is nil.")
237(defvar goto-tag-location-function nil
238  "Function of to go to the location in the buffer specified by a tag.
239One argument, the tag info returned by `snarf-tag-function'.")
240(defvar find-tag-regexp-search-function nil
241  "Search function passed to `find-tag-in-order' for finding a regexp tag.")
242(defvar find-tag-regexp-tag-order nil
243  "Tag order passed to `find-tag-in-order' for finding a regexp tag.")
244(defvar find-tag-regexp-next-line-after-failure-p nil
245  "Flag passed to `find-tag-in-order' for finding a regexp tag.")
246(defvar find-tag-search-function nil
247  "Search function passed to `find-tag-in-order' for finding a tag.")
248(defvar find-tag-tag-order nil
249  "Tag order passed to `find-tag-in-order' for finding a tag.")
250(defvar find-tag-next-line-after-failure-p nil
251  "Flag passed to `find-tag-in-order' for finding a tag.")
252(defvar list-tags-function nil
253  "Function to do the work of `list-tags' (which see).")
254(defvar tags-apropos-function nil
255  "Function to do the work of `tags-apropos' (which see).")
256(defvar tags-included-tables-function nil
257  "Function to do the work of `tags-included-tables' (which see).")
258(defvar verify-tags-table-function nil
259  "Function to return t iff current buffer contains valid tags file.")
260
261;; Initialize the tags table in the current buffer.
262;; Returns non-nil iff it is a valid tags table.  On
263;; non-nil return, the tags table state variable are
264;; made buffer-local and initialized to nil.
265(defun initialize-new-tags-table ()
266  (set (make-local-variable 'tags-table-files) nil)
267  (set (make-local-variable 'tags-completion-table) nil)
268  (set (make-local-variable 'tags-included-tables) nil)
269  ;; We used to initialize find-tag-marker-ring and tags-location-ring
270  ;; here, to new empty rings.  But that is wrong, because those
271  ;; are global.
272
273  ;; Value is t if we have found a valid tags table buffer.
274  (run-hook-with-args-until-success 'tags-table-format-functions))
275
276;;;###autoload
277(defun tags-table-mode ()
278  "Major mode for tags table file buffers."
279  (interactive)
280  (setq major-mode 'tags-table-mode)
281  (setq mode-name "Tags Table")
282  (initialize-new-tags-table))
283
284;;;###autoload
285(defun visit-tags-table (file &optional local)
286  "Tell tags commands to use tags table file FILE.
287FILE should be the name of a file created with the `etags' program.
288A directory name is ok too; it means file TAGS in that directory.
289
290Normally \\[visit-tags-table] sets the global value of `tags-file-name'.
291With a prefix arg, set the buffer-local value instead.
292When you find a tag with \\[find-tag], the buffer it finds the tag
293in is given a local value of this variable which is the name of the tags
294file the tag was in."
295  (interactive (list (read-file-name "Visit tags table (default TAGS): "
296				     default-directory
297				     (expand-file-name "TAGS"
298						       default-directory)
299				     t)
300		     current-prefix-arg))
301  (or (stringp file) (signal 'wrong-type-argument (list 'stringp file)))
302  ;; Bind tags-file-name so we can control below whether the local or
303  ;; global value gets set.  Calling visit-tags-table-buffer will
304  ;; initialize a buffer for the file and set tags-file-name to the
305  ;; Calling visit-tags-table-buffer with tags-file-name set to FILE will
306  ;; initialize a buffer for FILE and set tags-file-name to the
307  ;; fully-expanded name.
308  (let ((tags-file-name file))
309    (save-excursion
310      (or (visit-tags-table-buffer file)
311	  (signal 'file-error (list "Visiting tags table"
312				    "file does not exist"
313				    file)))
314      ;; Set FILE to the expanded name.
315      (setq file tags-file-name)))
316  (if local
317      ;; Set the local value of tags-file-name.
318      (set (make-local-variable 'tags-file-name) file)
319    ;; Set the global value of tags-file-name.
320    (setq-default tags-file-name file)))
321
322(defun tags-table-check-computed-list ()
323  "Compute `tags-table-computed-list' from `tags-table-list' if necessary."
324  (let ((expanded-list (mapcar 'tags-expand-table-name tags-table-list)))
325    (or (equal tags-table-computed-list-for expanded-list)
326	;; The list (or default-directory) has changed since last computed.
327	(let* ((compute-for (mapcar 'copy-sequence expanded-list))
328	       (tables (copy-sequence compute-for)) ;Mutated in the loop.
329	       (computed nil)
330	       table-buffer)
331
332	  (while tables
333	    (setq computed (cons (car tables) computed)
334		  table-buffer (get-file-buffer (car tables)))
335	    (if (and table-buffer
336		     ;; There is a buffer visiting the file.  Now make sure
337		     ;; it is initialized as a tag table buffer.
338		     (save-excursion
339		       (tags-verify-table (buffer-file-name table-buffer))))
340		(save-excursion
341		  (set-buffer table-buffer)
342		  (if (tags-included-tables)
343		      ;; Insert the included tables into the list we
344		      ;; are processing.
345		      (setcdr tables (nconc (mapcar 'tags-expand-table-name
346						    (tags-included-tables))
347					    (cdr tables)))))
348	      ;; This table is not in core yet.  Insert a placeholder
349	      ;; saying we must read it into core to check for included
350	      ;; tables before searching the next table in the list.
351	      (setq computed (cons t computed)))
352	    (setq tables (cdr tables)))
353
354	  ;; Record the tags-table-list value (and the context of the
355	  ;; current directory) we computed from.
356	  (setq tags-table-computed-list-for compute-for
357		tags-table-computed-list (nreverse computed))))))
358
359;; Extend `tags-table-computed-list' to remove the first `t' placeholder.
360;; An element of the list that is `t' is a placeholder indicating that the
361;; preceding element is a table that has not been read into core and might
362;; contain included tables to search.  On return, the first placeholder
363;; element will be gone and the element before it read into core and its
364;; included tables inserted into the list.
365(defun tags-table-extend-computed-list ()
366  (let ((list tags-table-computed-list))
367    (while (not (eq (nth 1 list) t))
368      (setq list (cdr list)))
369    (save-excursion
370      (if (tags-verify-table (car list))
371	  ;; We are now in the buffer visiting (car LIST).  Extract its
372	  ;; list of included tables and insert it into the computed list.
373	  (let ((tables (tags-included-tables))
374		(computed nil)
375		table-buffer)
376	    (while tables
377	      (setq computed (cons (car tables) computed)
378		    table-buffer (get-file-buffer (car tables)))
379	      (if table-buffer
380		  (save-excursion
381		    (set-buffer table-buffer)
382		    (if (tags-included-tables)
383			;; Insert the included tables into the list we
384			;; are processing.
385			(setcdr tables (append (tags-included-tables)
386					       tables))))
387		;; This table is not in core yet.  Insert a placeholder
388		;; saying we must read it into core to check for included
389		;; tables before searching the next table in the list.
390		(setq computed (cons t computed)))
391	      (setq tables (cdr tables)))
392	    (setq computed (nreverse computed))
393	    ;; COMPUTED now contains the list of included tables (and
394	    ;; tables included by them, etc.).  Now splice this into the
395	    ;; current list.
396	    (setcdr list (nconc computed (cdr (cdr list)))))
397	;; It was not a valid table, so just remove the following placeholder.
398	(setcdr list (cdr (cdr list)))))))
399
400;; Expand tags table name FILE into a complete file name.
401(defun tags-expand-table-name (file)
402  (setq file (expand-file-name file))
403  (if (file-directory-p file)
404      (expand-file-name "TAGS" file)
405    file))
406
407;; Like member, but comparison is done after tags-expand-table-name on both
408;; sides and elements of LIST that are t are skipped.
409(defun tags-table-list-member (file list)
410  (setq file (tags-expand-table-name file))
411  (while (and list
412	      (or (eq (car list) t)
413		  (not (string= file (tags-expand-table-name (car list))))))
414    (setq list (cdr list)))
415  list)
416
417(defun tags-verify-table (file)
418  "Read FILE into a buffer and verify that it is a valid tags table.
419Sets the current buffer to one visiting FILE (if it exists).
420Returns non-nil iff it is a valid table."
421  (if (get-file-buffer file)
422      ;; The file is already in a buffer.  Check for the visited file
423      ;; having changed since we last used it.
424      (let (win)
425	(set-buffer (get-file-buffer file))
426	(setq win (or verify-tags-table-function (tags-table-mode)))
427	(if (or (verify-visited-file-modtime (current-buffer))
428		;; Decide whether to revert the file.
429		;; revert-without-query can say to revert
430		;; or the user can say to revert.
431		(not (or (let ((tail revert-without-query)
432			       (found nil))
433			   (while tail
434			     (if (string-match (car tail) buffer-file-name)
435				 (setq found t))
436			     (setq tail (cdr tail)))
437			   found)
438			 tags-revert-without-query
439			 (yes-or-no-p
440			  (format "Tags file %s has changed, read new contents? "
441				  file)))))
442	    (and verify-tags-table-function
443		 (funcall verify-tags-table-function))
444	  (revert-buffer t t)
445	  (tags-table-mode)))
446    (and (file-exists-p file)
447	 (progn
448	   (set-buffer (find-file-noselect file))
449	   (or (string= file buffer-file-name)
450	       ;; find-file-noselect has changed the file name.
451	       ;; Propagate the change to tags-file-name and tags-table-list.
452	       (let ((tail (member file tags-table-list)))
453		 (if tail
454		     (setcar tail buffer-file-name))
455		 (if (eq file tags-file-name)
456		     (setq tags-file-name buffer-file-name))))
457	   (tags-table-mode)))))
458
459;; Subroutine of visit-tags-table-buffer.  Search the current tags tables
460;; for one that has tags for THIS-FILE (or that includes a table that
461;; does).  Return the name of the first table table listing THIS-FILE; if
462;; the table is one included by another table, it is the master table that
463;; we return.  If CORE-ONLY is non-nil, check only tags tables that are
464;; already in buffers--don't visit any new files.
465(defun tags-table-including (this-file core-only)
466  (let ((tables tags-table-computed-list)
467	(found nil))
468    ;; Loop over the list, looking for a table containing tags for THIS-FILE.
469    (while (and (not found)
470		tables)
471
472      (if core-only
473	  ;; Skip tables not in core.
474	  (while (eq (nth 1 tables) t)
475	    (setq tables (cdr (cdr tables))))
476	(if (eq (nth 1 tables) t)
477	    ;; This table has not been read into core yet.  Read it in now.
478	    (tags-table-extend-computed-list)))
479
480      (if tables
481	  ;; Select the tags table buffer and get the file list up to date.
482	  (let ((tags-file-name (car tables)))
483	    (visit-tags-table-buffer 'same)
484	    (if (member this-file (mapcar 'expand-file-name
485					  (tags-table-files)))
486		;; Found it.
487		(setq found tables))))
488      (setq tables (cdr tables)))
489    (if found
490	;; Now determine if the table we found was one included by another
491	;; table, not explicitly listed.  We do this by checking each
492	;; element of the computed list to see if it appears in the user's
493	;; explicit list; the last element we will check is FOUND itself.
494	;; Then we return the last one which did in fact appear in
495	;; tags-table-list.
496	(let ((could-be nil)
497	      (elt tags-table-computed-list))
498	  (while (not (eq elt (cdr found)))
499	    (if (tags-table-list-member (car elt) tags-table-list)
500		;; This table appears in the user's list, so it could be
501		;; the one which includes the table we found.
502		(setq could-be (car elt)))
503	    (setq elt (cdr elt))
504	    (if (eq t (car elt))
505		(setq elt (cdr elt))))
506	  ;; The last element we found in the computed list before FOUND
507	  ;; that appears in the user's list will be the table that
508	  ;; included the one we found.
509	  could-be))))
510
511;; Subroutine of visit-tags-table-buffer.  Move tags-table-list-pointer
512;; along and set tags-file-name.  Returns nil when out of tables.
513(defun tags-next-table ()
514  ;; If there is a placeholder element next, compute the list to replace it.
515  (while (eq (nth 1 tags-table-list-pointer) t)
516    (tags-table-extend-computed-list))
517
518  ;; Go to the next table in the list.
519  (setq tags-table-list-pointer (cdr tags-table-list-pointer))
520  (or tags-table-list-pointer
521      ;; Wrap around.
522      (setq tags-table-list-pointer tags-table-computed-list))
523
524  (if (eq tags-table-list-pointer tags-table-list-started-at)
525      ;; We have come full circle.  No more tables.
526      (setq tags-table-list-pointer nil)
527    ;; Set tags-file-name to the name from the list.  It is already expanded.
528    (setq tags-file-name (car tags-table-list-pointer))))
529
530;;;###autoload
531(defun visit-tags-table-buffer (&optional cont)
532  "Select the buffer containing the current tags table.
533If optional arg is a string, visit that file as a tags table.
534If optional arg is t, visit the next table in `tags-table-list'.
535If optional arg is the atom `same', don't look for a new table;
536 just select the buffer visiting `tags-file-name'.
537If arg is nil or absent, choose a first buffer from information in
538 `tags-file-name', `tags-table-list', `tags-table-list-pointer'.
539Returns t if it visits a tags table, or nil if there are no more in the list."
540
541  ;; Set tags-file-name to the tags table file we want to visit.
542  (cond ((eq cont 'same)
543	 ;; Use the ambient value of tags-file-name.
544	 (or tags-file-name
545	     (error "%s"
546		    (substitute-command-keys
547		     (concat "No tags table in use; "
548			     "use \\[visit-tags-table] to select one")))))
549
550	((eq t cont)
551	 ;; Find the next table.
552	 (if (tags-next-table)
553	     ;; Skip over nonexistent files.
554	     (while (and (not (or (get-file-buffer tags-file-name)
555				  (file-exists-p tags-file-name)))
556			 (tags-next-table)))))
557
558	(t
559	 ;; Pick a table out of our hat.
560	 (tags-table-check-computed-list) ;Get it up to date, we might use it.
561	 (setq tags-file-name
562	       (or
563		;; If passed a string, use that.
564		(if (stringp cont)
565		    (prog1 cont
566		      (setq cont nil)))
567		;; First, try a local variable.
568		(cdr (assq 'tags-file-name (buffer-local-variables)))
569		;; Second, try a user-specified function to guess.
570		(and default-tags-table-function
571		     (funcall default-tags-table-function))
572		;; Third, look for a tags table that contains tags for the
573		;; current buffer's file.  If one is found, the lists will
574		;; be frobnicated, and CONT will be set non-nil so we don't
575		;; do it below.
576		(and buffer-file-name
577		     (or
578		      ;; First check only tables already in buffers.
579		      (tags-table-including buffer-file-name t)
580		      ;; Since that didn't find any, now do the
581		      ;; expensive version: reading new files.
582		      (tags-table-including buffer-file-name nil)))
583		;; Fourth, use the user variable tags-file-name, if it is
584		;; not already in the current list.
585		(and tags-file-name
586		     (not (tags-table-list-member tags-file-name
587						  tags-table-computed-list))
588		     tags-file-name)
589		;; Fifth, use the user variable giving the table list.
590		;; Find the first element of the list that actually exists.
591		(let ((list tags-table-list)
592		      file)
593		  (while (and list
594			      (setq file (tags-expand-table-name (car list)))
595			      (not (get-file-buffer file))
596			      (not (file-exists-p file)))
597		    (setq list (cdr list)))
598		  (car list))
599		;; Finally, prompt the user for a file name.
600		(expand-file-name
601		 (read-file-name "Visit tags table (default TAGS): "
602				 default-directory
603				 "TAGS"
604				 t))))))
605
606  ;; Expand the table name into a full file name.
607  (setq tags-file-name (tags-expand-table-name tags-file-name))
608
609  (unless (and (eq cont t) (null tags-table-list-pointer))
610    ;; Verify that tags-file-name names a valid tags table.
611    ;; Bind another variable with the value of tags-file-name
612    ;; before we switch buffers, in case tags-file-name is buffer-local.
613    (let ((curbuf (current-buffer))
614	  (local-tags-file-name tags-file-name))
615      (if (tags-verify-table local-tags-file-name)
616
617	  ;; We have a valid tags table.
618	  (progn
619	    ;; Bury the tags table buffer so it
620	    ;; doesn't get in the user's way.
621	    (bury-buffer (current-buffer))
622
623	    ;; If this was a new table selection (CONT is nil), make
624	    ;; sure tags-table-list includes the chosen table, and
625	    ;; update the list pointer variables.
626	    (or cont
627		;; Look in the list for the table we chose.
628		(let ((found (tags-table-list-member
629			      local-tags-file-name
630			      tags-table-computed-list)))
631		  (if found
632		      ;; There it is.  Just switch to it.
633		      (setq tags-table-list-pointer found
634			    tags-table-list-started-at found)
635
636		    ;; The table is not in the current set.
637		    ;; Try to find it in another previously used set.
638		    (let ((sets tags-table-set-list))
639		      (while (and sets
640				  (not (tags-table-list-member
641					local-tags-file-name
642					(car sets))))
643			(setq sets (cdr sets)))
644		      (if sets
645			  ;; Found in some other set.  Switch to that set.
646			  (progn
647			    (or (memq tags-table-list tags-table-set-list)
648				;; Save the current list.
649				(setq tags-table-set-list
650				      (cons tags-table-list
651					    tags-table-set-list)))
652			    (setq tags-table-list (car sets)))
653
654			;; Not found in any existing set.
655			(if (and tags-table-list
656				 (or (eq t tags-add-tables)
657				     (and tags-add-tables
658					  (y-or-n-p
659					   (concat "Keep current list of "
660						   "tags tables also? ")))))
661			    ;; Add it to the current list.
662			    (setq tags-table-list (cons local-tags-file-name
663							tags-table-list))
664
665			  ;; Make a fresh list, and store the old one.
666			  (message "Starting a new list of tags tables")
667			  (or (null tags-table-list)
668			      (memq tags-table-list tags-table-set-list)
669			      (setq tags-table-set-list
670				    (cons tags-table-list
671					  tags-table-set-list)))
672			  ;; Clear out buffers holding old tables.
673			  (dolist (table tags-table-list)
674			    ;; The list can contain items `t'.
675			    (if (stringp table)
676				(let ((buffer (find-buffer-visiting table)))
677			      (if buffer
678				  (kill-buffer buffer)))))
679			  (setq tags-table-list (list local-tags-file-name))))
680
681		      ;; Recompute tags-table-computed-list.
682		      (tags-table-check-computed-list)
683		      ;; Set the tags table list state variables to start
684		      ;; over from tags-table-computed-list.
685		      (setq tags-table-list-started-at tags-table-computed-list
686			    tags-table-list-pointer
687			    tags-table-computed-list)))))
688
689	    ;; Return of t says the tags table is valid.
690	    t)
691
692	;; The buffer was not valid.  Don't use it again.
693	(set-buffer curbuf)
694	(kill-local-variable 'tags-file-name)
695	(if (eq local-tags-file-name tags-file-name)
696	    (setq tags-file-name nil))
697	(error "File %s is not a valid tags table" local-tags-file-name)))))
698
699(defun tags-reset-tags-tables ()
700  "Reset tags state to cancel effect of any previous \\[visit-tags-table] or \\[find-tag]."
701  (interactive)
702  ;; Clear out the markers we are throwing away.
703  (let ((i 0))
704    (while (< i find-tag-marker-ring-length)
705      (if (aref (cddr tags-location-ring) i)
706	  (set-marker (aref (cddr tags-location-ring) i) nil))
707      (if (aref (cddr find-tag-marker-ring) i)
708	  (set-marker (aref (cddr find-tag-marker-ring) i) nil))
709      (setq i (1+ i))))
710  (setq tags-file-name nil
711	tags-location-ring (make-ring find-tag-marker-ring-length)
712	find-tag-marker-ring (make-ring find-tag-marker-ring-length)
713	tags-table-list nil
714	tags-table-computed-list nil
715	tags-table-computed-list-for nil
716	tags-table-list-pointer nil
717	tags-table-list-started-at nil
718	tags-table-set-list nil))
719
720(defun file-of-tag (&optional relative)
721  "Return the file name of the file whose tags point is within.
722Assumes the tags table is the current buffer.
723If RELATIVE is non-nil, file name returned is relative to tags
724table file's directory. If RELATIVE is nil, file name returned
725is complete."
726  (funcall file-of-tag-function relative))
727
728;;;###autoload
729(defun tags-table-files ()
730  "Return a list of files in the current tags table.
731Assumes the tags table is the current buffer.  The file names are returned
732as they appeared in the `etags' command that created the table, usually
733without directory names."
734  (or tags-table-files
735      (setq tags-table-files
736	    (funcall tags-table-files-function))))
737
738(defun tags-included-tables ()
739  "Return a list of tags tables included by the current table.
740Assumes the tags table is the current buffer."
741  (or tags-included-tables
742      (setq tags-included-tables (funcall tags-included-tables-function))))
743
744;; Build tags-completion-table on demand.  The single current tags table
745;; and its included tags tables (and their included tables, etc.) have
746;; their tags included in the completion table.
747(defun tags-completion-table ()
748  (or tags-completion-table
749      ;; No cached value for this buffer.
750      (condition-case ()
751	  (let (current-table combined-table)
752	    (message "Making tags completion table for %s..." buffer-file-name)
753	    (save-excursion
754	      ;; Iterate over the current list of tags tables.
755	      (while (visit-tags-table-buffer (and combined-table t))
756		;; Find possible completions in this table.
757		(setq current-table (funcall tags-completion-table-function))
758		;; Merge this buffer's completions into the combined table.
759		(if combined-table
760		    (mapatoms
761		     (lambda (sym) (intern (symbol-name sym) combined-table))
762		     current-table)
763		  (setq combined-table current-table))))
764	    (message "Making tags completion table for %s...done"
765		     buffer-file-name)
766	    ;; Cache the result a buffer-local variable.
767	    (setq tags-completion-table combined-table))
768	(quit (message "Tags completion table construction aborted.")
769	      (setq tags-completion-table nil)))))
770
771;; Completion function for tags.  Does normal try-completion,
772;; but builds tags-completion-table on demand.
773(defun tags-complete-tag (string predicate what)
774  (save-excursion
775    ;; If we need to ask for the tag table, allow that.
776    (let ((enable-recursive-minibuffers t))
777      (visit-tags-table-buffer))
778    (if (eq what t)
779	(all-completions string (tags-completion-table) predicate)
780      (try-completion string (tags-completion-table) predicate))))
781
782;; Read a tag name from the minibuffer with defaulting and completion.
783(defun find-tag-tag (string)
784  (let* ((completion-ignore-case (if (memq tags-case-fold-search '(t nil))
785				     tags-case-fold-search
786				   case-fold-search))
787	 (default (funcall (or find-tag-default-function
788			       (get major-mode 'find-tag-default-function)
789			       'find-tag-default)))
790	 (spec (completing-read (if default
791				    (format "%s (default %s): "
792					    (substring string 0 (string-match "[ :]+\\'" string))
793					    default)
794				  string)
795				'tags-complete-tag
796				nil nil nil nil default)))
797    (if (equal spec "")
798	(or default (error "There is no default tag"))
799      spec)))
800
801(defvar last-tag nil
802  "Last tag found by \\[find-tag].")
803
804;; Get interactive args for find-tag{-noselect,-other-window,-regexp}.
805(defun find-tag-interactive (prompt &optional no-default)
806  (if (and current-prefix-arg last-tag)
807      (list nil (if (< (prefix-numeric-value current-prefix-arg) 0)
808		    '-
809		  t))
810    (list (if no-default
811	      (read-string prompt)
812	    (find-tag-tag prompt)))))
813
814(defvar find-tag-history nil)
815
816;; Dynamic bondage:
817(eval-when-compile
818  (defvar etags-case-fold-search)
819  (defvar etags-syntax-table))
820
821;;;###autoload
822(defun find-tag-noselect (tagname &optional next-p regexp-p)
823  "Find tag (in current tags table) whose name contains TAGNAME.
824Returns the buffer containing the tag's definition and moves its point there,
825but does not select the buffer.
826The default for TAGNAME is the expression in the buffer near point.
827
828If second arg NEXT-P is t (interactively, with prefix arg), search for
829another tag that matches the last tagname or regexp used.  When there are
830multiple matches for a tag, more exact matches are found first.  If NEXT-P
831is the atom `-' (interactively, with prefix arg that is a negative number
832or just \\[negative-argument]), pop back to the previous tag gone to.
833
834If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
835
836A marker representing the point when this command is invoked is pushed
837onto a ring and may be popped back to with \\[pop-tag-mark].
838Contrast this with the ring of marks gone to by the command.
839
840See documentation of variable `tags-file-name'."
841  (interactive (find-tag-interactive "Find tag: "))
842
843  (setq find-tag-history (cons tagname find-tag-history))
844  ;; Save the current buffer's value of `find-tag-hook' before
845  ;; selecting the tags table buffer.  For the same reason, save value
846  ;; of `tags-file-name' in case it has a buffer-local value.
847  (let ((local-find-tag-hook find-tag-hook))
848    (if (eq '- next-p)
849	;; Pop back to a previous location.
850	(if (ring-empty-p tags-location-ring)
851	    (error "No previous tag locations")
852	  (let ((marker (ring-remove tags-location-ring 0)))
853	    (prog1
854		;; Move to the saved location.
855		(set-buffer (or (marker-buffer marker)
856                                (error "The marked buffer has been deleted")))
857	      (goto-char (marker-position marker))
858	      ;; Kill that marker so it doesn't slow down editing.
859	      (set-marker marker nil nil)
860	      ;; Run the user's hook.  Do we really want to do this for pop?
861	      (run-hooks 'local-find-tag-hook))))
862      ;; Record whence we came.
863      (ring-insert find-tag-marker-ring (point-marker))
864      (if (and next-p last-tag)
865	  ;; Find the same table we last used.
866	  (visit-tags-table-buffer 'same)
867	;; Pick a table to use.
868	(visit-tags-table-buffer)
869	;; Record TAGNAME for a future call with NEXT-P non-nil.
870	(setq last-tag tagname))
871      ;; Record the location so we can pop back to it later.
872      (let ((marker (make-marker)))
873	(save-excursion
874	  (set-buffer
875	   ;; find-tag-in-order does the real work.
876	   (find-tag-in-order
877	    (if (and next-p last-tag) last-tag tagname)
878	    (if regexp-p
879		find-tag-regexp-search-function
880	      find-tag-search-function)
881	    (if regexp-p
882		find-tag-regexp-tag-order
883	      find-tag-tag-order)
884	    (if regexp-p
885		find-tag-regexp-next-line-after-failure-p
886	      find-tag-next-line-after-failure-p)
887	    (if regexp-p "matching" "containing")
888	    (or (not next-p) (not last-tag))))
889	  (set-marker marker (point))
890	  (run-hooks 'local-find-tag-hook)
891	  (ring-insert tags-location-ring marker)
892	  (current-buffer))))))
893
894;;;###autoload
895(defun find-tag (tagname &optional next-p regexp-p)
896  "Find tag (in current tags table) whose name contains TAGNAME.
897Select the buffer containing the tag's definition, and move point there.
898The default for TAGNAME is the expression in the buffer around or before point.
899
900If second arg NEXT-P is t (interactively, with prefix arg), search for
901another tag that matches the last tagname or regexp used.  When there are
902multiple matches for a tag, more exact matches are found first.  If NEXT-P
903is the atom `-' (interactively, with prefix arg that is a negative number
904or just \\[negative-argument]), pop back to the previous tag gone to.
905
906If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
907
908A marker representing the point when this command is invoked is pushed
909onto a ring and may be popped back to with \\[pop-tag-mark].
910Contrast this with the ring of marks gone to by the command.
911
912See documentation of variable `tags-file-name'."
913  (interactive (find-tag-interactive "Find tag: "))
914  (let* ((buf (find-tag-noselect tagname next-p regexp-p))
915	 (pos (with-current-buffer buf (point))))
916    (condition-case nil
917	(switch-to-buffer buf)
918      (error (pop-to-buffer buf)))
919    (goto-char pos)))
920;;;###autoload (define-key esc-map "." 'find-tag)
921
922;;;###autoload
923(defun find-tag-other-window (tagname &optional next-p regexp-p)
924  "Find tag (in current tags table) whose name contains TAGNAME.
925Select the buffer containing the tag's definition in another window, and
926move point there.  The default for TAGNAME is the expression in the buffer
927around or before point.
928
929If second arg NEXT-P is t (interactively, with prefix arg), search for
930another tag that matches the last tagname or regexp used.  When there are
931multiple matches for a tag, more exact matches are found first.  If NEXT-P
932is negative (interactively, with prefix arg that is a negative number or
933just \\[negative-argument]), pop back to the previous tag gone to.
934
935If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
936
937A marker representing the point when this command is invoked is pushed
938onto a ring and may be popped back to with \\[pop-tag-mark].
939Contrast this with the ring of marks gone to by the command.
940
941See documentation of variable `tags-file-name'."
942  (interactive (find-tag-interactive "Find tag other window: "))
943
944  ;; This hair is to deal with the case where the tag is found in the
945  ;; selected window's buffer; without the hair, point is moved in both
946  ;; windows.  To prevent this, we save the selected window's point before
947  ;; doing find-tag-noselect, and restore it after.
948  (let* ((window-point (window-point (selected-window)))
949	 (tagbuf (find-tag-noselect tagname next-p regexp-p))
950	 (tagpoint (progn (set-buffer tagbuf) (point))))
951    (set-window-point (prog1
952			  (selected-window)
953			(switch-to-buffer-other-window tagbuf)
954			;; We have to set this new window's point; it
955			;; might already have been displaying a
956			;; different portion of tagbuf, in which case
957			;; switch-to-buffer-other-window doesn't set
958			;; the window's point from the buffer.
959			(set-window-point (selected-window) tagpoint))
960		      window-point)))
961;;;###autoload (define-key ctl-x-4-map "." 'find-tag-other-window)
962
963;;;###autoload
964(defun find-tag-other-frame (tagname &optional next-p)
965  "Find tag (in current tags table) whose name contains TAGNAME.
966Select the buffer containing the tag's definition in another frame, and
967move point there.  The default for TAGNAME is the expression in the buffer
968around or before point.
969
970If second arg NEXT-P is t (interactively, with prefix arg), search for
971another tag that matches the last tagname or regexp used.  When there are
972multiple matches for a tag, more exact matches are found first.  If NEXT-P
973is negative (interactively, with prefix arg that is a negative number or
974just \\[negative-argument]), pop back to the previous tag gone to.
975
976If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
977
978A marker representing the point when this command is invoked is pushed
979onto a ring and may be popped back to with \\[pop-tag-mark].
980Contrast this with the ring of marks gone to by the command.
981
982See documentation of variable `tags-file-name'."
983  (interactive (find-tag-interactive "Find tag other frame: "))
984  (let ((pop-up-frames t))
985    (find-tag-other-window tagname next-p)))
986;;;###autoload (define-key ctl-x-5-map "." 'find-tag-other-frame)
987
988;;;###autoload
989(defun find-tag-regexp (regexp &optional next-p other-window)
990  "Find tag (in current tags table) whose name matches REGEXP.
991Select the buffer containing the tag's definition and move point there.
992
993If second arg NEXT-P is t (interactively, with prefix arg), search for
994another tag that matches the last tagname or regexp used.  When there are
995multiple matches for a tag, more exact matches are found first.  If NEXT-P
996is negative (interactively, with prefix arg that is a negative number or
997just \\[negative-argument]), pop back to the previous tag gone to.
998
999If third arg OTHER-WINDOW is non-nil, select the buffer in another window.
1000
1001A marker representing the point when this command is invoked is pushed
1002onto a ring and may be popped back to with \\[pop-tag-mark].
1003Contrast this with the ring of marks gone to by the command.
1004
1005See documentation of variable `tags-file-name'."
1006  (interactive (find-tag-interactive "Find tag regexp: " t))
1007  ;; We go through find-tag-other-window to do all the display hair there.
1008  (funcall (if other-window 'find-tag-other-window 'find-tag)
1009	   regexp next-p t))
1010;;;###autoload (define-key esc-map [?\C-.] 'find-tag-regexp)
1011
1012;;;###autoload (define-key esc-map "*" 'pop-tag-mark)
1013
1014;;;###autoload
1015(defun pop-tag-mark ()
1016  "Pop back to where \\[find-tag] was last invoked.
1017
1018This is distinct from invoking \\[find-tag] with a negative argument
1019since that pops a stack of markers at which tags were found, not from
1020where they were found."
1021  (interactive)
1022  (if (ring-empty-p find-tag-marker-ring)
1023      (error "No previous locations for find-tag invocation"))
1024  (let ((marker (ring-remove find-tag-marker-ring 0)))
1025    (switch-to-buffer (or (marker-buffer marker)
1026                          (error "The marked buffer has been deleted")))
1027    (goto-char (marker-position marker))
1028    (set-marker marker nil nil)))
1029
1030;; Internal tag finding function.
1031
1032;; PATTERN is a string to pass to second arg SEARCH-FORWARD-FUNC, and to
1033;; any member of the function list ORDER (third arg).  If ORDER is nil,
1034;; use saved state to continue a previous search.
1035
1036;; Fourth arg NEXT-LINE-AFTER-FAILURE-P is non-nil if after a failed match,
1037;; point should be moved to the next line.
1038
1039;; Fifth arg MATCHING is a string, an English '-ing' word, to be used in
1040;; an error message.
1041
1042;; Algorithm is as follows.  For each qualifier-func in ORDER, go to
1043;; beginning of tags file, and perform inner loop: for each naive match for
1044;; PATTERN found using SEARCH-FORWARD-FUNC, qualify the naive match using
1045;; qualifier-func.  If it qualifies, go to the specified line in the
1046;; specified source file and return.  Qualified matches are remembered to
1047;; avoid repetition.  State is saved so that the loop can be continued.
1048
1049(defvar tag-lines-already-matched nil)	;matches remembered here between calls
1050
1051(defun find-tag-in-order (pattern
1052			  search-forward-func
1053			  order
1054			  next-line-after-failure-p
1055			  matching
1056			  first-search)
1057  (let (file				;name of file containing tag
1058	tag-info			;where to find the tag in FILE
1059	(first-table t)
1060	(tag-order order)
1061	(match-marker (make-marker))
1062	goto-func
1063	(case-fold-search (if (memq tags-case-fold-search '(nil t))
1064			      tags-case-fold-search
1065			    case-fold-search))
1066	)
1067    (save-excursion
1068
1069      (if first-search
1070	  ;; This is the start of a search for a fresh tag.
1071	  ;; Clear the list of tags matched by the previous search.
1072	  ;; find-tag-noselect has already put us in the first tags table
1073	  ;; buffer before we got called.
1074	  (setq tag-lines-already-matched nil)
1075	;; Continuing to search for the tag specified last time.
1076	;; tag-lines-already-matched lists locations matched in previous
1077	;; calls so we don't visit the same tag twice if it matches twice
1078	;; during two passes with different qualification predicates.
1079	;; Switch to the current tags table buffer.
1080	(visit-tags-table-buffer 'same))
1081
1082      ;; Get a qualified match.
1083      (catch 'qualified-match-found
1084
1085	;; Iterate over the list of tags tables.
1086	(while (or first-table
1087		   (visit-tags-table-buffer t))
1088
1089	  (and first-search first-table
1090	       ;; Start at beginning of tags file.
1091	       (goto-char (point-min)))
1092
1093	  (setq first-table nil)
1094
1095	  ;; Iterate over the list of ordering predicates.
1096	  (while order
1097	    (while (funcall search-forward-func pattern nil t)
1098	      ;; Naive match found.  Qualify the match.
1099	      (and (funcall (car order) pattern)
1100		   ;; Make sure it is not a previous qualified match.
1101		   (not (member (set-marker match-marker (save-excursion
1102							   (beginning-of-line)
1103							   (point)))
1104				tag-lines-already-matched))
1105		   (throw 'qualified-match-found nil))
1106	      (if next-line-after-failure-p
1107		  (forward-line 1)))
1108	    ;; Try the next flavor of match.
1109	    (setq order (cdr order))
1110	    (goto-char (point-min)))
1111	  (setq order tag-order))
1112	;; We throw out on match, so only get here if there were no matches.
1113	;; Clear out the markers we use to avoid duplicate matches so they
1114	;; don't slow down editting and are immediately available for GC.
1115	(while tag-lines-already-matched
1116	  (set-marker (car tag-lines-already-matched) nil nil)
1117	  (setq tag-lines-already-matched (cdr tag-lines-already-matched)))
1118	(set-marker match-marker nil nil)
1119	(error "No %stags %s %s" (if first-search "" "more ")
1120	       matching pattern))
1121
1122      ;; Found a tag; extract location info.
1123      (beginning-of-line)
1124      (setq tag-lines-already-matched (cons match-marker
1125					    tag-lines-already-matched))
1126      ;; Expand the filename, using the tags table buffer's default-directory.
1127      ;; We should be able to search for file-name backwards in file-of-tag:
1128      ;; the beginning-of-line is ok except when positioned on a "file-name" tag.
1129      (setq file (expand-file-name
1130		  (if (memq (car order) '(tag-exact-file-name-match-p
1131					  tag-file-name-match-p
1132					  tag-partial-file-name-match-p))
1133                      (save-excursion (next-line 1)
1134                                      (file-of-tag))
1135                    (file-of-tag)))
1136	    tag-info (funcall snarf-tag-function))
1137
1138      ;; Get the local value in the tags table buffer before switching buffers.
1139      (setq goto-func goto-tag-location-function)
1140      (tag-find-file-of-tag-noselect file)
1141      (widen)
1142      (push-mark)
1143      (funcall goto-func tag-info)
1144
1145      ;; Return the buffer where the tag was found.
1146      (current-buffer))))
1147
1148(defun tag-find-file-of-tag-noselect (file)
1149  ;; Find the right line in the specified file.
1150  ;; If we are interested in compressed-files,
1151  ;; we search files with extensions.
1152  ;; otherwise only the real file.
1153  (let* ((buffer-search-extensions (if (featurep 'jka-compr)
1154				       tags-compression-info-list
1155				     '("")))
1156	 the-buffer
1157	 (file-search-extensions buffer-search-extensions))
1158    ;; search a buffer visiting the file with each possible extension
1159    ;; Note: there is a small inefficiency in find-buffer-visiting :
1160    ;;   truename is computed even if not needed. Not too sure about this
1161    ;;   but I suspect truename computation accesses the disk.
1162    ;;   It is maybe a good idea to optimise this find-buffer-visiting.
1163    ;; An alternative would be to use only get-file-buffer
1164    ;; but this looks less "sure" to find the buffer for the file.
1165    (while (and (not the-buffer) buffer-search-extensions)
1166      (setq the-buffer (find-buffer-visiting (concat file (car buffer-search-extensions))))
1167      (setq buffer-search-extensions (cdr buffer-search-extensions)))
1168    ;; if found a buffer but file modified, ensure we re-read !
1169    (if (and the-buffer (not (verify-visited-file-modtime the-buffer)))
1170	(find-file-noselect (buffer-file-name the-buffer)))
1171    ;; if no buffer found, search for files with possible extensions on disk
1172    (while (and (not the-buffer) file-search-extensions)
1173      (if (not (file-exists-p (concat file (car file-search-extensions))))
1174	  (setq file-search-extensions (cdr file-search-extensions))
1175	(setq the-buffer (find-file-noselect (concat file (car file-search-extensions))))))
1176    (if (not the-buffer)
1177	(if (featurep 'jka-compr)
1178	    (error "File %s (with or without extensions %s) not found" file tags-compression-info-list)
1179	  (error "File %s not found" file))
1180      (set-buffer the-buffer))))
1181
1182(defun tag-find-file-of-tag (file)
1183  (let ((buf (tag-find-file-of-tag-noselect file)))
1184    (condition-case nil
1185	(switch-to-buffer buf)
1186      (error (pop-to-buffer buf)))))
1187
1188;; `etags' TAGS file format support.
1189
1190;; If the current buffer is a valid etags TAGS file, give it local values of
1191;; the tags table format variables, and return non-nil.
1192(defun etags-recognize-tags-table ()
1193  (and (etags-verify-tags-table)
1194       ;; It is annoying to flash messages on the screen briefly,
1195       ;; and this message is not useful.  -- rms
1196       ;; (message "%s is an `etags' TAGS file" buffer-file-name)
1197       (mapc (lambda (elt) (set (make-local-variable (car elt)) (cdr elt)))
1198	     '((file-of-tag-function . etags-file-of-tag)
1199	       (tags-table-files-function . etags-tags-table-files)
1200	       (tags-completion-table-function . etags-tags-completion-table)
1201	       (snarf-tag-function . etags-snarf-tag)
1202	       (goto-tag-location-function . etags-goto-tag-location)
1203	       (find-tag-regexp-search-function . re-search-forward)
1204	       (find-tag-regexp-tag-order . (tag-re-match-p))
1205	       (find-tag-regexp-next-line-after-failure-p . t)
1206	       (find-tag-search-function . search-forward)
1207	       (find-tag-tag-order . (tag-exact-file-name-match-p
1208                                      tag-file-name-match-p
1209				      tag-exact-match-p
1210				      tag-implicit-name-match-p
1211				      tag-symbol-match-p
1212				      tag-word-match-p
1213				      tag-partial-file-name-match-p
1214				      tag-any-match-p))
1215	       (find-tag-next-line-after-failure-p . nil)
1216	       (list-tags-function . etags-list-tags)
1217	       (tags-apropos-function . etags-tags-apropos)
1218	       (tags-included-tables-function . etags-tags-included-tables)
1219	       (verify-tags-table-function . etags-verify-tags-table)
1220	       ))))
1221
1222;; Return non-nil iff the current buffer is a valid etags TAGS file.
1223(defun etags-verify-tags-table ()
1224  ;; Use eq instead of = in case char-after returns nil.
1225  (eq (char-after (point-min)) ?\f))
1226
1227(defun etags-file-of-tag (&optional relative)
1228  (save-excursion
1229    (re-search-backward "\f\n\\([^\n]+\\),[0-9]*\n")
1230    (let ((str (buffer-substring (match-beginning 1) (match-end 1))))
1231      (if relative
1232	  str
1233	(expand-file-name str
1234			  (file-truename default-directory))))))
1235
1236
1237(defun etags-tags-completion-table ()
1238  (let ((table (make-vector 511 0))
1239	(progress-reporter
1240	 (make-progress-reporter
1241	  (format "Making tags completion table for %s..." buffer-file-name)
1242	  (point-min) (point-max))))
1243    (save-excursion
1244      (goto-char (point-min))
1245      ;; This monster regexp matches an etags tag line.
1246      ;;   \1 is the string to match;
1247      ;;   \2 is not interesting;
1248      ;;   \3 is the guessed tag name; XXX guess should be better eg DEFUN
1249      ;;   \4 is not interesting;
1250      ;;   \5 is the explicitly-specified tag name.
1251      ;;   \6 is the line to start searching at;
1252      ;;   \7 is the char to start searching at.
1253      (while (re-search-forward
1254	      "^\\(\\([^\177]+[^-a-zA-Z0-9_+*$:\177]+\\)?\
1255\\([-a-zA-Z0-9_+*$?:]+\\)[^-a-zA-Z0-9_+*$?:\177]*\\)\177\
1256\\(\\([^\n\001]+\\)\001\\)?\\([0-9]+\\)?,\\([0-9]+\\)?\n"
1257	      nil t)
1258	(intern	(prog1 (if (match-beginning 5)
1259			   ;; There is an explicit tag name.
1260			   (buffer-substring (match-beginning 5) (match-end 5))
1261			 ;; No explicit tag name.  Best guess.
1262			 (buffer-substring (match-beginning 3) (match-end 3)))
1263		  (progress-reporter-update progress-reporter (point)))
1264		table)))
1265    table))
1266
1267(defun etags-snarf-tag (&optional use-explicit)
1268  (let (tag-text line startpos explicit-start)
1269    (if (save-excursion
1270	  (forward-line -1)
1271	  (looking-at "\f\n"))
1272	;; The match was for a source file name, not any tag within a file.
1273	;; Give text of t, meaning to go exactly to the location we specify,
1274	;; the beginning of the file.
1275	(setq tag-text t
1276	      line nil
1277	      startpos (point-min))
1278
1279      ;; Find the end of the tag and record the whole tag text.
1280      (search-forward "\177")
1281      (setq tag-text (buffer-substring (1- (point))
1282				       (save-excursion (beginning-of-line)
1283						       (point))))
1284      ;; If use-explicit is non nil and explicit tag is present, use it as part of
1285      ;; return value. Else just skip it.
1286      (setq explicit-start (point))
1287      (when (and (search-forward "\001" (save-excursion (forward-line 1) (point)) t)
1288		 use-explicit)
1289	(setq tag-text (buffer-substring explicit-start (1- (point)))))
1290
1291
1292      (if (looking-at "[0-9]")
1293	  (setq line (string-to-number (buffer-substring
1294                                        (point)
1295                                        (progn (skip-chars-forward "0-9")
1296                                               (point))))))
1297      (search-forward ",")
1298      (if (looking-at "[0-9]")
1299	  (setq startpos (string-to-number (buffer-substring
1300                                            (point)
1301                                            (progn (skip-chars-forward "0-9")
1302                                                   (point)))))))
1303    ;; Leave point on the next line of the tags file.
1304    (forward-line 1)
1305    (cons tag-text (cons line startpos))))
1306
1307;; TAG-INFO is a cons (TEXT LINE . POSITION) where TEXT is the initial part
1308;; of a line containing the tag and POSITION is the character position of
1309;; TEXT within the file (starting from 1); LINE is the line number.  If
1310;; TEXT is t, it means the tag refers to exactly LINE or POSITION
1311;; (whichever is present, LINE having preference, no searching.  Either
1312;; LINE or POSITION may be nil; POSITION is used if present.  If the tag
1313;; isn't exactly at the given position then look around that position using
1314;; a search window which expands until it hits the start of file.
1315(defun etags-goto-tag-location (tag-info)
1316  (let ((startpos (cdr (cdr tag-info)))
1317	(line (car (cdr tag-info)))
1318	offset found pat)
1319    (if (eq (car tag-info) t)
1320	;; Direct file tag.
1321	(cond (line (goto-line line))
1322	      (startpos (goto-char startpos))
1323	      (t (error "etags.el BUG: bogus direct file tag")))
1324      ;; This constant is 1/2 the initial search window.
1325      ;; There is no sense in making it too small,
1326      ;; since just going around the loop once probably
1327      ;; costs about as much as searching 2000 chars.
1328      (setq offset 1000
1329	    found nil
1330	    pat (concat (if (eq selective-display t)
1331			    "\\(^\\|\^m\\)" "^")
1332			(regexp-quote (car tag-info))))
1333      ;; The character position in the tags table is 0-origin.
1334      ;; Convert it to a 1-origin Emacs character position.
1335      (if startpos (setq startpos (1+ startpos)))
1336      ;; If no char pos was given, try the given line number.
1337      (or startpos
1338	  (if line
1339	      (setq startpos (progn (goto-line line)
1340				    (point)))))
1341      (or startpos
1342	  (setq startpos (point-min)))
1343      ;; First see if the tag is right at the specified location.
1344      (goto-char startpos)
1345      (setq found (looking-at pat))
1346      (while (and (not found)
1347		  (progn
1348		    (goto-char (- startpos offset))
1349		    (not (bobp))))
1350	(setq found
1351	      (re-search-forward pat (+ startpos offset) t)
1352	      offset (* 3 offset)))	; expand search window
1353      (or found
1354	  (re-search-forward pat nil t)
1355	  (error "Rerun etags: `%s' not found in %s"
1356		 pat buffer-file-name)))
1357    ;; Position point at the right place
1358    ;; if the search string matched an extra Ctrl-m at the beginning.
1359    (and (eq selective-display t)
1360	 (looking-at "\^m")
1361	 (forward-char 1))
1362    (beginning-of-line)))
1363
1364(defun etags-list-tags (file)
1365  (goto-char (point-min))
1366  (when (re-search-forward (concat "\f\n" "\\(" file "\\)" ",") nil t)
1367    (let ((path (save-excursion (forward-line 1) (file-of-tag)))
1368	  ;; Get the local value in the tags table
1369	  ;; buffer before switching buffers.
1370	  (goto-func goto-tag-location-function)
1371	  tag tag-info pt)
1372    (forward-line 1)
1373    (while (not (or (eobp) (looking-at "\f")))
1374      (setq tag-info (save-excursion (funcall snarf-tag-function t))
1375	    tag (car tag-info)
1376	    pt (with-current-buffer standard-output (point)))
1377      (princ tag)
1378      (when (= (aref tag 0) ?\() (princ " ...)"))
1379      (with-current-buffer standard-output
1380	(make-text-button pt (point)
1381			  'tag-info tag-info
1382			  'file-path path
1383			  'goto-func goto-func
1384			  'action (lambda (button)
1385				    (let ((tag-info (button-get button 'tag-info))
1386					  (goto-func (button-get button 'goto-func)))
1387				      (tag-find-file-of-tag (button-get button 'file-path))
1388				      (widen)
1389				      (funcall goto-func tag-info)))
1390			  'face 'tags-tag-face
1391			  'type 'button))
1392      (terpri)
1393      (forward-line 1))
1394    t)))
1395
1396(defmacro tags-with-face (face &rest body)
1397  "Execute BODY, give output to `standard-output' face FACE."
1398  (let ((pp (make-symbol "start")))
1399    `(let ((,pp (with-current-buffer standard-output (point))))
1400       ,@body
1401       (put-text-property ,pp (with-current-buffer standard-output (point))
1402			  'face ,face standard-output))))
1403
1404(defun etags-tags-apropos-additional (regexp)
1405  "Display tags matching REGEXP from `tags-apropos-additional-actions'."
1406  (with-current-buffer standard-output
1407    (dolist (oba tags-apropos-additional-actions)
1408      (princ "\n\n")
1409      (tags-with-face 'highlight (princ (car oba)))
1410      (princ":\n\n")
1411      (let* ((beg (point))
1412	     (symbs (car (cddr oba)))
1413             (ins-symb (lambda (sy)
1414                         (let ((sn (symbol-name sy)))
1415                           (when (string-match regexp sn)
1416                             (make-text-button (point)
1417					  (progn (princ sy) (point))
1418					  'action-internal(cadr oba)
1419					  'action (lambda (button) (funcall
1420								    (button-get button 'action-internal)
1421								    (button-get button 'item)))
1422					  'item sn
1423					  'face tags-tag-face
1424					  'type 'button)
1425                             (terpri))))))
1426        (when (symbolp symbs)
1427          (if (boundp symbs)
1428	      (setq symbs (symbol-value symbs))
1429	    (insert "symbol `" (symbol-name symbs) "' has no value\n")
1430	    (setq symbs nil)))
1431        (if (vectorp symbs)
1432	    (mapatoms ins-symb symbs)
1433	  (dolist (sy symbs)
1434	    (funcall ins-symb (car sy))))
1435        (sort-lines nil beg (point))))))
1436
1437(defun etags-tags-apropos (string)
1438  (when tags-apropos-verbose
1439    (princ "Tags in file `")
1440    (tags-with-face 'highlight (princ buffer-file-name))
1441    (princ "':\n\n"))
1442  (goto-char (point-min))
1443  (let ((progress-reporter (make-progress-reporter
1444			    (format "Making tags apropos buffer for `%s'..."
1445				    string)
1446			    (point-min) (point-max))))
1447    (while (re-search-forward string nil t)
1448      (progress-reporter-update progress-reporter (point))
1449      (beginning-of-line)
1450
1451      (let* ( ;; Get the local value in the tags table
1452	     ;; buffer before switching buffers.
1453	     (goto-func goto-tag-location-function)
1454	     (tag-info (save-excursion (funcall snarf-tag-function)))
1455	     (tag (if (eq t (car tag-info)) nil (car tag-info)))
1456	     (file-path (save-excursion (if tag (file-of-tag)
1457					  (save-excursion (next-line 1)
1458							  (file-of-tag)))))
1459	     (file-label (if tag (file-of-tag t)
1460			   (save-excursion (next-line 1)
1461					   (file-of-tag t))))
1462	     (pt (with-current-buffer standard-output (point))))
1463	(if tag
1464	    (progn
1465	      (princ (format "[%s]: " file-label))
1466	      (princ tag)
1467	      (when (= (aref tag 0) ?\() (princ " ...)"))
1468	      (with-current-buffer standard-output
1469		(make-text-button pt (point)
1470				  'tag-info tag-info
1471				  'file-path file-path
1472				  'goto-func goto-func
1473				  'action (lambda (button)
1474					    (let ((tag-info (button-get button 'tag-info))
1475						  (goto-func (button-get button 'goto-func)))
1476					      (tag-find-file-of-tag (button-get button 'file-path))
1477					      (widen)
1478					      (funcall goto-func tag-info)))
1479				  'face 'tags-tag-face
1480				  'type 'button)))
1481	  (princ (format "- %s" file-label))
1482	  (with-current-buffer standard-output
1483	    (make-text-button pt (point)
1484			      'file-path file-path
1485			      'action (lambda (button)
1486					(tag-find-file-of-tag (button-get button 'file-path))
1487					;; Get the local value in the tags table
1488					;; buffer before switching buffers.
1489					(goto-char (point-min)))
1490			      'face 'tags-tag-face
1491			      'type 'button))
1492	  ))
1493      (terpri)
1494      (forward-line 1))
1495    (message nil))
1496  (when tags-apropos-verbose (princ "\n")))
1497
1498(defun etags-tags-table-files ()
1499  (let ((files nil)
1500	beg)
1501    (goto-char (point-min))
1502    (while (search-forward "\f\n" nil t)
1503      (setq beg (point))
1504      (end-of-line)
1505      (skip-chars-backward "^," beg)
1506      (or (looking-at "include$")
1507	  (setq files (cons (buffer-substring beg (1- (point))) files))))
1508    (nreverse files)))
1509
1510(defun etags-tags-included-tables ()
1511  (let ((files nil)
1512	beg)
1513    (goto-char (point-min))
1514    (while (search-forward "\f\n" nil t)
1515      (setq beg (point))
1516      (end-of-line)
1517      (skip-chars-backward "^," beg)
1518      (if (looking-at "include$")
1519	  ;; Expand in the default-directory of the tags table buffer.
1520	  (setq files (cons (expand-file-name (buffer-substring beg (1- (point))))
1521			    files))))
1522    (nreverse files)))
1523
1524;; Empty tags file support.
1525
1526;; Recognize an empty file and give it local values of the tags table format
1527;; variables which do nothing.
1528(defun tags-recognize-empty-tags-table ()
1529  (and (zerop (buffer-size))
1530       (mapc (lambda (sym) (set (make-local-variable sym) 'ignore))
1531	     '(tags-table-files-function
1532	       tags-completion-table-function
1533	       find-tag-regexp-search-function
1534	       find-tag-search-function
1535	       tags-apropos-function
1536	       tags-included-tables-function))
1537       (set (make-local-variable 'verify-tags-table-function)
1538            (lambda () (zerop (buffer-size))))))
1539
1540;; Match qualifier functions for tagnames.
1541;; These functions assume the etags file format defined in etc/ETAGS.EBNF.
1542
1543;; This might be a neat idea, but it's too hairy at the moment.
1544;;(defmacro tags-with-syntax (&rest body)
1545;;   `(let ((current (current-buffer))
1546;;	   (otable (syntax-table))
1547;;	   (buffer (find-file-noselect (file-of-tag)))
1548;;	   table)
1549;;       (unwind-protect
1550;;	   (progn
1551;;	     (set-buffer buffer)
1552;;	     (setq table (syntax-table))
1553;;	     (set-buffer current)
1554;;	     (set-syntax-table table)
1555;;            ,@body)
1556;;       (set-syntax-table otable))))
1557;;(put 'tags-with-syntax 'edebug-form-spec '(&rest form))
1558
1559;; exact file name match, i.e. searched tag must match complete file
1560;; name including directories parts if there are some.
1561(defun tag-exact-file-name-match-p (tag)
1562  (and (looking-at ",[0-9\n]")
1563       (save-excursion (backward-char (+ 2 (length tag)))
1564		       (looking-at "\f\n"))))
1565;; file name match as above, but searched tag must match the file
1566;; name not including the directories if there are some.
1567(defun tag-file-name-match-p (tag)
1568  (and (looking-at ",[0-9\n]")
1569       (save-excursion (backward-char (1+ (length tag)))
1570		       (looking-at "/"))))
1571;; this / to detect we are after a directory separator is ok for unix,
1572;; is there a variable that contains the regexp for directory separator
1573;; on whatever operating system ?
1574;; Looks like ms-win will lose here :).
1575
1576;; t if point is at a tag line that matches TAG exactly.
1577;; point should be just after a string that matches TAG.
1578(defun tag-exact-match-p (tag)
1579  ;; The match is really exact if there is an explicit tag name.
1580  (or (and (eq (char-after (point)) ?\001)
1581	   (eq (char-after (- (point) (length tag) 1)) ?\177))
1582      ;; We are not on the explicit tag name, but perhaps it follows.
1583      (looking-at (concat "[^\177\n]*\177" (regexp-quote tag) "\001"))))
1584
1585;; t if point is at a tag line that has an implicit name.
1586;; point should be just after a string that matches TAG.
1587(defun tag-implicit-name-match-p (tag)
1588  ;; Look at the comment of the make_tag function in lib-src/etags.c for
1589  ;; a textual description of the four rules.
1590  (and (string-match "^[^ \t()=,;]+$" tag) ;rule #1
1591       (looking-at "[ \t()=,;]?\177")	;rules #2 and #4
1592       (save-excursion
1593	 (backward-char (1+ (length tag)))
1594	 (looking-at "[\n \t()=,;]"))))	;rule #3
1595
1596;; t if point is at a tag line that matches TAG as a symbol.
1597;; point should be just after a string that matches TAG.
1598(defun tag-symbol-match-p (tag)
1599  (and (looking-at "\\Sw.*\177") (looking-at "\\S_.*\177")
1600       (save-excursion
1601	 (backward-char (1+ (length tag)))
1602	 (and (looking-at "\\Sw") (looking-at "\\S_")))))
1603
1604;; t if point is at a tag line that matches TAG as a word.
1605;; point should be just after a string that matches TAG.
1606(defun tag-word-match-p (tag)
1607  (and (looking-at "\\b.*\177")
1608       (save-excursion (backward-char (length tag))
1609		       (looking-at "\\b"))))
1610
1611;; partial file name match, i.e. searched tag must match a substring
1612;; of the file name (potentially including a directory separator).
1613(defun tag-partial-file-name-match-p (tag)
1614  (and (looking-at ".*,[0-9\n]")
1615       (save-excursion (beginning-of-line)
1616                       (backward-char 2)
1617  		       (looking-at "\f\n"))))
1618
1619;; t if point is in a tag line with a tag containing TAG as a substring.
1620(defun tag-any-match-p (tag)
1621  (looking-at ".*\177"))
1622
1623;; t if point is at a tag line that matches RE as a regexp.
1624(defun tag-re-match-p (re)
1625  (save-excursion
1626    (beginning-of-line)
1627    (let ((bol (point)))
1628      (and (search-forward "\177" (save-excursion (end-of-line) (point)) t)
1629	   (re-search-backward re bol t)))))
1630
1631(defcustom tags-loop-revert-buffers nil
1632  "*Non-nil means tags-scanning loops should offer to reread changed files.
1633These loops normally read each file into Emacs, but when a file
1634is already visited, they use the existing buffer.
1635When this flag is non-nil, they offer to revert the existing buffer
1636in the case where the file has changed since you visited it."
1637  :type 'boolean
1638  :group 'etags)
1639
1640;;;###autoload
1641(defun next-file (&optional initialize novisit)
1642  "Select next file among files in current tags table.
1643
1644A first argument of t (prefix arg, if interactive) initializes to the
1645beginning of the list of files in the tags table.  If the argument is
1646neither nil nor t, it is evalled to initialize the list of files.
1647
1648Non-nil second argument NOVISIT means use a temporary buffer
1649 to save time and avoid uninteresting warnings.
1650
1651Value is nil if the file was already visited;
1652if the file was newly read in, the value is the filename."
1653  ;; Make the interactive arg t if there was any prefix arg.
1654  (interactive (list (if current-prefix-arg t)))
1655  (cond ((not initialize)
1656	 ;; Not the first run.
1657	 )
1658	((eq initialize t)
1659	 ;; Initialize the list from the tags table.
1660	 (save-excursion
1661	   ;; Visit the tags table buffer to get its list of files.
1662	   (visit-tags-table-buffer)
1663	   ;; Copy the list so we can setcdr below, and expand the file
1664	   ;; names while we are at it, in this buffer's default directory.
1665	   (setq next-file-list (mapcar 'expand-file-name (tags-table-files)))
1666	   ;; Iterate over all the tags table files, collecting
1667	   ;; a complete list of referenced file names.
1668	   (while (visit-tags-table-buffer t)
1669	     ;; Find the tail of the working list and chain on the new
1670	     ;; sublist for this tags table.
1671	     (let ((tail next-file-list))
1672	       (while (cdr tail)
1673		 (setq tail (cdr tail)))
1674	       ;; Use a copy so the next loop iteration will not modify the
1675	       ;; list later returned by (tags-table-files).
1676	       (if tail
1677		   (setcdr tail (mapcar 'expand-file-name (tags-table-files)))
1678		 (setq next-file-list (mapcar 'expand-file-name
1679					      (tags-table-files))))))))
1680	(t
1681	 ;; Initialize the list by evalling the argument.
1682	 (setq next-file-list (eval initialize))))
1683  (unless next-file-list
1684    (and novisit
1685	 (get-buffer " *next-file*")
1686	 (kill-buffer " *next-file*"))
1687    (error "All files processed"))
1688  (let* ((next (car next-file-list))
1689	 (buffer (get-file-buffer next))
1690	 (new (not buffer)))
1691    ;; Advance the list before trying to find the file.
1692    ;; If we get an error finding the file, don't get stuck on it.
1693    (setq next-file-list (cdr next-file-list))
1694    ;; Optionally offer to revert buffers
1695    ;; if the files have changed on disk.
1696    (and buffer tags-loop-revert-buffers
1697	 (not (verify-visited-file-modtime buffer))
1698	 (with-current-buffer buffer
1699	   (revert-buffer t)))
1700    (if (not (and new novisit))
1701	(set-buffer (find-file-noselect next novisit))
1702      ;; Like find-file, but avoids random warning messages.
1703      (set-buffer (get-buffer-create " *next-file*"))
1704      (kill-all-local-variables)
1705      (erase-buffer)
1706      (setq new next)
1707      (insert-file-contents new nil))
1708    new))
1709
1710(defvar tags-loop-operate nil
1711  "Form for `tags-loop-continue' to eval to change one file.")
1712
1713(defvar tags-loop-scan
1714  '(error "%s"
1715	  (substitute-command-keys
1716	   "No \\[tags-search] or \\[tags-query-replace] in progress"))
1717  "Form for `tags-loop-continue' to eval to scan one file.
1718If it returns non-nil, this file needs processing by evalling
1719\`tags-loop-operate'.  Otherwise, move on to the next file.")
1720
1721(defun tags-loop-eval (form)
1722  "Evaluate FORM and return its result.
1723Bind `case-fold-search' during the evaluation, depending on the value of
1724`tags-case-fold-search'."
1725  (let ((case-fold-search (if (memq tags-case-fold-search '(t nil))
1726			      tags-case-fold-search
1727			    case-fold-search)))
1728    (eval form)))
1729
1730
1731;;;###autoload
1732(defun tags-loop-continue (&optional first-time)
1733  "Continue last \\[tags-search] or \\[tags-query-replace] command.
1734Used noninteractively with non-nil argument to begin such a command (the
1735argument is passed to `next-file', which see).
1736
1737Two variables control the processing we do on each file: the value of
1738`tags-loop-scan' is a form to be executed on each file to see if it is
1739interesting (it returns non-nil if so) and `tags-loop-operate' is a form to
1740evaluate to operate on an interesting file.  If the latter evaluates to
1741nil, we exit; otherwise we scan the next file."
1742  (interactive)
1743  (let (new
1744	;; Non-nil means we have finished one file
1745	;; and should not scan it again.
1746	file-finished
1747	original-point
1748	(messaged nil))
1749    (while
1750	(progn
1751	  ;; Scan files quickly for the first or next interesting one.
1752	  ;; This starts at point in the current buffer.
1753	  (while (or first-time file-finished
1754		     (save-restriction
1755		       (widen)
1756		       (not (tags-loop-eval tags-loop-scan))))
1757	    ;; If nothing was found in the previous file, and
1758	    ;; that file isn't in a temp buffer, restore point to
1759	    ;; where it was.
1760	    (when original-point
1761	      (goto-char original-point))
1762
1763	    (setq file-finished nil)
1764	    (setq new (next-file first-time t))
1765
1766	    ;; If NEW is non-nil, we got a temp buffer,
1767	    ;; and NEW is the file name.
1768	    (when (or messaged
1769		      (and (not first-time)
1770			   (> baud-rate search-slow-speed)
1771			   (setq messaged t)))
1772	      (message "Scanning file %s..." (or new buffer-file-name)))
1773
1774	    (setq first-time nil)
1775	    (setq original-point (if new nil (point)))
1776	    (goto-char (point-min)))
1777
1778	  ;; If we visited it in a temp buffer, visit it now for real.
1779	  (if new
1780	      (let ((pos (point)))
1781		(erase-buffer)
1782		(set-buffer (find-file-noselect new))
1783		(setq new nil)		;No longer in a temp buffer.
1784		(widen)
1785		(goto-char pos))
1786	    (push-mark original-point t))
1787
1788	  (switch-to-buffer (current-buffer))
1789
1790	  ;; Now operate on the file.
1791	  ;; If value is non-nil, continue to scan the next file.
1792	  (tags-loop-eval tags-loop-operate))
1793      (setq file-finished t))
1794    (and messaged
1795	 (null tags-loop-operate)
1796	 (message "Scanning file %s...found" buffer-file-name))))
1797;;;###autoload (define-key esc-map "," 'tags-loop-continue)
1798
1799;;;###autoload
1800(defun tags-search (regexp &optional file-list-form)
1801  "Search through all files listed in tags table for match for REGEXP.
1802Stops when a match is found.
1803To continue searching for next match, use command \\[tags-loop-continue].
1804
1805See documentation of variable `tags-file-name'."
1806  (interactive "sTags search (regexp): ")
1807  (if (and (equal regexp "")
1808	   (eq (car tags-loop-scan) 're-search-forward)
1809	   (null tags-loop-operate))
1810      ;; Continue last tags-search as if by M-,.
1811      (tags-loop-continue nil)
1812    (setq tags-loop-scan `(re-search-forward ',regexp nil t)
1813	  tags-loop-operate nil)
1814    (tags-loop-continue (or file-list-form t))))
1815
1816;;;###autoload
1817(defun tags-query-replace (from to &optional delimited file-list-form start end)
1818  "Do `query-replace-regexp' of FROM with TO on all files listed in tags table.
1819Third arg DELIMITED (prefix arg) means replace only word-delimited matches.
1820If you exit (\\[keyboard-quit], RET or q), you can resume the query replace
1821with the command \\[tags-loop-continue].
1822
1823See documentation of variable `tags-file-name'."
1824  (interactive (query-replace-read-args "Tags query replace (regexp)" t t))
1825  (setq tags-loop-scan `(let ,(unless (equal from (downcase from))
1826				'((case-fold-search nil)))
1827			  (if (re-search-forward ',from nil t)
1828			      ;; When we find a match, move back
1829			      ;; to the beginning of it so perform-replace
1830			      ;; will see it.
1831			      (goto-char (match-beginning 0))))
1832	tags-loop-operate `(perform-replace ',from ',to t t ',delimited))
1833  (tags-loop-continue (or file-list-form t)))
1834
1835(defun tags-complete-tags-table-file (string predicate what)
1836  (save-excursion
1837    ;; If we need to ask for the tag table, allow that.
1838    (let ((enable-recursive-minibuffers t))
1839      (visit-tags-table-buffer))
1840    (if (eq what t)
1841	(all-completions string (tags-table-files) predicate)
1842      (try-completion string (tags-table-files) predicate))))
1843
1844;;;###autoload
1845(defun list-tags (file &optional next-match)
1846  "Display list of tags in file FILE.
1847This searches only the first table in the list, and no included tables.
1848FILE should be as it appeared in the `etags' command, usually without a
1849directory specification."
1850  (interactive (list (completing-read "List tags in file: "
1851				      'tags-complete-tags-table-file
1852				      nil t nil)))
1853  (with-output-to-temp-buffer "*Tags List*"
1854    (princ "Tags in file `")
1855    (tags-with-face 'highlight (princ file))
1856    (princ "':\n\n")
1857    (save-excursion
1858      (let ((first-time t)
1859	    (gotany nil))
1860	(while (visit-tags-table-buffer (not first-time))
1861	  (setq first-time nil)
1862	  (if (funcall list-tags-function file)
1863	      (setq gotany t)))
1864	(or gotany
1865	    (error "File %s not in current tags tables" file)))))
1866  (with-current-buffer "*Tags List*"
1867    (require 'apropos)
1868    (with-no-warnings
1869      (apropos-mode))
1870    (setq buffer-read-only t)))
1871
1872;;;###autoload
1873(defun tags-apropos (regexp)
1874  "Display list of all tags in tags table REGEXP matches."
1875  (interactive "sTags apropos (regexp): ")
1876  (with-output-to-temp-buffer "*Tags List*"
1877    (princ "Click mouse-2 to follow tags.\n\nTags matching regexp `")
1878    (tags-with-face 'highlight (princ regexp))
1879    (princ "':\n\n")
1880    (save-excursion
1881      (let ((first-time t))
1882	(while (visit-tags-table-buffer (not first-time))
1883	  (setq first-time nil)
1884	  (funcall tags-apropos-function regexp))))
1885    (etags-tags-apropos-additional regexp))
1886  (with-current-buffer "*Tags List*"
1887    (require 'apropos)
1888    (apropos-mode)
1889    ;; apropos-mode is derived from fundamental-mode and it kills
1890    ;; all local variables.
1891    (setq buffer-read-only t)))
1892
1893;; XXX Kludge interface.
1894
1895(define-button-type 'tags-select-tags-table
1896  'action 'select-tags-table-select
1897  'help-echo "RET, t or mouse-2: select tags table")
1898
1899;; XXX If a file is in multiple tables, selection may get the wrong one.
1900;;;###autoload
1901(defun select-tags-table ()
1902  "Select a tags table file from a menu of those you have already used.
1903The list of tags tables to select from is stored in `tags-table-set-list';
1904see the doc of that variable if you want to add names to the list."
1905  (interactive)
1906  (pop-to-buffer "*Tags Table List*")
1907  (setq buffer-read-only nil)
1908  (erase-buffer)
1909  (let ((set-list tags-table-set-list)
1910	(desired-point nil)
1911	b)
1912    (when tags-table-list
1913      (setq desired-point (point-marker))
1914      (setq b (point))
1915      (princ (mapcar 'abbreviate-file-name tags-table-list) (current-buffer))
1916      (make-text-button b (point) 'type 'tags-select-tags-table
1917                        'etags-table (car tags-table-list))
1918      (insert "\n"))
1919    (while set-list
1920      (unless (eq (car set-list) tags-table-list)
1921	(setq b (point))
1922	(princ (mapcar 'abbreviate-file-name (car set-list)) (current-buffer))
1923	(make-text-button b (point) 'type 'tags-select-tags-table
1924                          'etags-table (car (car set-list)))
1925	(insert "\n"))
1926      (setq set-list (cdr set-list)))
1927    (when tags-file-name
1928      (or desired-point
1929          (setq desired-point (point-marker)))
1930      (setq b (point))
1931      (insert (abbreviate-file-name tags-file-name))
1932      (make-text-button b (point) 'type 'tags-select-tags-table
1933                        'etags-table tags-file-name)
1934      (insert "\n"))
1935    (setq set-list (delete tags-file-name
1936			   (apply 'nconc (cons (copy-sequence tags-table-list)
1937					       (mapcar 'copy-sequence
1938						       tags-table-set-list)))))
1939    (while set-list
1940      (setq b (point))
1941      (insert (abbreviate-file-name (car set-list)))
1942      (make-text-button b (point) 'type 'tags-select-tags-table
1943                          'etags-table (car set-list))
1944      (insert "\n")
1945      (setq set-list (delete (car set-list) set-list)))
1946    (goto-char (point-min))
1947    (insert-before-markers
1948     "Type `t' to select a tags table or set of tags tables:\n\n")
1949    (if desired-point
1950	(goto-char desired-point))
1951    (set-window-start (selected-window) 1 t))
1952  (set-buffer-modified-p nil)
1953  (select-tags-table-mode))
1954
1955(defvar select-tags-table-mode-map
1956  (let ((map (make-sparse-keymap)))
1957    (set-keymap-parent map button-buffer-map)
1958    (define-key map "t" 'push-button)
1959    (define-key map " " 'next-line)
1960    (define-key map "\^?" 'previous-line)
1961    (define-key map "n" 'next-line)
1962    (define-key map "p" 'previous-line)
1963    (define-key map "q" 'select-tags-table-quit)
1964    map))
1965
1966(define-derived-mode select-tags-table-mode fundamental-mode "Select Tags Table"
1967  "Major mode for choosing a current tags table among those already loaded.
1968
1969\\{select-tags-table-mode-map}"
1970  (setq buffer-read-only t))
1971
1972(defun select-tags-table-select (button)
1973  "Select the tags table named on this line."
1974  (interactive (list (or (button-at (line-beginning-position))
1975                         (error "No tags table on current line"))))
1976  (let ((name (button-get button 'etags-table)))
1977    (visit-tags-table name)
1978    (select-tags-table-quit)
1979    (message "Tags table now %s" name)))
1980
1981(defun select-tags-table-quit ()
1982  "Kill the buffer and delete the selected window."
1983  (interactive)
1984  (quit-window t (selected-window)))
1985
1986;; Note, there is another definition of this function in bindings.el.
1987;;;###autoload
1988(defun complete-tag ()
1989  "Perform tags completion on the text around point.
1990Completes to the set of names listed in the current tags table.
1991The string to complete is chosen in the same way as the default
1992for \\[find-tag] (which see)."
1993  (interactive)
1994  (or tags-table-list
1995      tags-file-name
1996      (error "%s"
1997	     (substitute-command-keys
1998	      "No tags table loaded; try \\[visit-tags-table]")))
1999  (let ((completion-ignore-case (if (memq tags-case-fold-search '(t nil))
2000				    tags-case-fold-search
2001				  case-fold-search))
2002	(pattern (funcall (or find-tag-default-function
2003			      (get major-mode 'find-tag-default-function)
2004			      'find-tag-default)))
2005	beg
2006	completion)
2007    (or pattern
2008	(error "Nothing to complete"))
2009    (search-backward pattern)
2010    (setq beg (point))
2011    (forward-char (length pattern))
2012    (setq completion (tags-complete-tag pattern nil nil))
2013    (cond ((eq completion t))
2014	  ((null completion)
2015	   (message "Can't find completion for \"%s\"" pattern)
2016	   (ding))
2017	  ((not (string= pattern completion))
2018	   (delete-region beg (point))
2019	   (insert completion))
2020	  (t
2021	   (message "Making completion list...")
2022	   (with-output-to-temp-buffer "*Completions*"
2023	     (display-completion-list
2024	      (all-completions pattern 'tags-complete-tag nil)
2025	      pattern))
2026	   (message "Making completion list...%s" "done")))))
2027
2028(dolist (x '("^No tags table in use; use .* to select one$"
2029	     "^There is no default tag$"
2030	     "^No previous tag locations$"
2031	     "^File .* is not a valid tags table$"
2032	     "^No \\(more \\|\\)tags \\(matching\\|containing\\) "
2033	     "^Rerun etags: `.*' not found in "
2034	     "^All files processed$"
2035	     "^No .* or .* in progress$"
2036	     "^File .* not in current tags tables$"
2037	     "^No tags table loaded"
2038	     "^Nothing to complete$"))
2039	(add-to-list 'debug-ignored-errors x))
2040
2041(provide 'etags)
2042
2043;; arch-tag: b897c2b5-08f3-4837-b2d3-0e7d6db1b63e
2044;;; etags.el ends here
2045