1;;; vc-hooks.el --- resident support for version-control
2
3;; Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
4;;   2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author:     FSF (see vc.el for full credits)
7;; Maintainer: Andre Spiegel <spiegel@gnu.org>
8
9;; $Id$
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;; This is the always-loaded portion of VC.  It takes care of
31;; VC-related activities that are done when you visit a file, so that
32;; vc.el itself is loaded only when you use a VC command.  See the
33;; commentary of vc.el.
34
35;;; Code:
36
37(eval-when-compile
38  (require 'cl))
39
40;; Customization Variables (the rest is in vc.el)
41
42(defvar vc-ignore-vc-files nil)
43(make-obsolete-variable 'vc-ignore-vc-files
44                        "set `vc-handled-backends' to nil to disable VC.")
45
46(defvar vc-master-templates ())
47(make-obsolete-variable 'vc-master-templates
48 "to define master templates for a given BACKEND, use
49vc-BACKEND-master-templates.  To enable or disable VC for a given
50BACKEND, use `vc-handled-backends'.")
51
52(defvar vc-header-alist ())
53(make-obsolete-variable 'vc-header-alist 'vc-BACKEND-header)
54
55(defcustom vc-ignore-dir-regexp
56  ;; Stop SMB, automounter, AFS, and DFS host lookups.
57  "\\`\\(?:[\\/][\\/]\\|/\\(?:net\\|afs\\|\\.\\\.\\.\\)/\\)\\'"
58  "Regexp matching directory names that are not under VC's control.
59The default regexp prevents fruitless and time-consuming attempts
60to determine the VC status in directories in which filenames are
61interpreted as hostnames."
62  :type 'regexp
63  :group 'vc)
64
65(defcustom vc-handled-backends '(RCS CVS SVN SCCS Arch MCVS)
66  ;; Arch and MCVS come last because they are per-tree rather than per-dir.
67  "*List of version control backends for which VC will be used.
68Entries in this list will be tried in order to determine whether a
69file is under that sort of version control.
70Removing an entry from the list prevents VC from being activated
71when visiting a file managed by that backend.
72An empty list disables VC altogether."
73  :type '(repeat symbol)
74  :version "21.1"
75  :group 'vc)
76
77(defcustom vc-path
78  (if (file-directory-p "/usr/sccs")
79      '("/usr/sccs")
80    nil)
81  "*List of extra directories to search for version control commands."
82  :type '(repeat directory)
83  :group 'vc)
84
85(defcustom vc-make-backup-files nil
86  "*If non-nil, backups of registered files are made as with other files.
87If nil (the default), files covered by version control don't get backups."
88  :type 'boolean
89  :group 'vc
90  :group 'backup)
91
92(defcustom vc-follow-symlinks 'ask
93  "*What to do if visiting a symbolic link to a file under version control.
94Editing such a file through the link bypasses the version control system,
95which is dangerous and probably not what you want.
96
97If this variable is t, VC follows the link and visits the real file,
98telling you about it in the echo area.  If it is `ask', VC asks for
99confirmation whether it should follow the link.  If nil, the link is
100visited and a warning displayed."
101  :type '(choice (const :tag "Ask for confirmation" ask)
102		 (const :tag "Visit link and warn" nil)
103		 (const :tag "Follow link" t))
104  :group 'vc)
105
106(defcustom vc-display-status t
107  "*If non-nil, display revision number and lock status in modeline.
108Otherwise, not displayed."
109  :type 'boolean
110  :group 'vc)
111
112
113(defcustom vc-consult-headers t
114  "*If non-nil, identify work files by searching for version headers."
115  :type 'boolean
116  :group 'vc)
117
118(defcustom vc-keep-workfiles t
119  "*If non-nil, don't delete working files after registering changes.
120If the back-end is CVS, workfiles are always kept, regardless of the
121value of this flag."
122  :type 'boolean
123  :group 'vc)
124
125(defcustom vc-mistrust-permissions nil
126  "*If non-nil, don't assume permissions/ownership track version-control status.
127If nil, do rely on the permissions.
128See also variable `vc-consult-headers'."
129  :type 'boolean
130  :group 'vc)
131
132(defun vc-mistrust-permissions (file)
133  "Internal access function to variable `vc-mistrust-permissions' for FILE."
134  (or (eq vc-mistrust-permissions 't)
135      (and vc-mistrust-permissions
136	   (funcall vc-mistrust-permissions
137		    (vc-backend-subdirectory-name file)))))
138
139(defcustom vc-stay-local t
140  "*Non-nil means use local operations when possible for remote repositories.
141This avoids slow queries over the network and instead uses heuristics
142and past information to determine the current status of a file.
143
144The value can also be a regular expression or list of regular
145expressions to match against the host name of a repository; then VC
146only stays local for hosts that match it.  Alternatively, the value
147can be a list of regular expressions where the first element is the
148symbol `except'; then VC always stays local except for hosts matched
149by these regular expressions."
150  :type '(choice (const :tag "Always stay local" t)
151	  (const :tag "Don't stay local" nil)
152	  (list :format "\nExamine hostname and %v" :tag "Examine hostname ..."
153		(set :format "%v" :inline t (const :format "%t" :tag "don't" except))
154		(regexp :format " stay local,\n%t: %v" :tag "if it matches")
155		(repeat :format "%v%i\n" :inline t (regexp :tag "or"))))
156  :version "22.1"
157  :group 'vc)
158
159(defun vc-stay-local-p (file)
160  "Return non-nil if VC should stay local when handling FILE.
161This uses the `repository-hostname' backend operation."
162  (let* ((backend (vc-backend file))
163	 (sym (vc-make-backend-sym backend 'stay-local))
164	 (stay-local (if (boundp sym) (symbol-value sym) t)))
165    (if (eq stay-local t) (setq stay-local vc-stay-local))
166    (if (symbolp stay-local) stay-local
167      (let ((dirname (if (file-directory-p file)
168			 (directory-file-name file)
169		       (file-name-directory file))))
170	(eq 'yes
171	    (or (vc-file-getprop dirname 'vc-stay-local-p)
172		(vc-file-setprop
173		 dirname 'vc-stay-local-p
174		 (let ((hostname (vc-call-backend
175				  backend 'repository-hostname dirname)))
176		   (if (not hostname)
177		       'no
178		     (let ((default t))
179		       (if (eq (car-safe stay-local) 'except)
180			   (setq default nil stay-local (cdr stay-local)))
181		       (when (consp stay-local)
182			 (setq stay-local
183			       (mapconcat 'identity stay-local "\\|")))
184		       (if (if (string-match stay-local hostname)
185			       default (not default))
186			   'yes 'no)))))))))))
187
188;;; This is handled specially now.
189;; Tell Emacs about this new kind of minor mode
190;; (add-to-list 'minor-mode-alist '(vc-mode vc-mode))
191
192(make-variable-buffer-local 'vc-mode)
193(put 'vc-mode 'permanent-local t)
194
195(defun vc-mode (&optional arg)
196  ;; Dummy function for C-h m
197  "Version Control minor mode.
198This minor mode is automatically activated whenever you visit a file under
199control of one of the revision control systems in `vc-handled-backends'.
200VC commands are globally reachable under the prefix `\\[vc-prefix-map]':
201\\{vc-prefix-map}")
202
203(defmacro vc-error-occurred (&rest body)
204  `(condition-case nil (progn ,@body nil) (error t)))
205
206;; We need a notion of per-file properties because the version
207;; control state of a file is expensive to derive --- we compute
208;; them when the file is initially found, keep them up to date
209;; during any subsequent VC operations, and forget them when
210;; the buffer is killed.
211
212(defvar vc-file-prop-obarray (make-vector 17 0)
213  "Obarray for per-file properties.")
214
215(defvar vc-touched-properties nil)
216
217(defun vc-file-setprop (file property value)
218  "Set per-file VC PROPERTY for FILE to VALUE."
219  (if (and vc-touched-properties
220	   (not (memq property vc-touched-properties)))
221      (setq vc-touched-properties (append (list property)
222					  vc-touched-properties)))
223  (put (intern file vc-file-prop-obarray) property value))
224
225(defun vc-file-getprop (file property)
226  "Get per-file VC PROPERTY for FILE."
227  (get (intern file vc-file-prop-obarray) property))
228
229(defun vc-file-clearprops (file)
230  "Clear all VC properties of FILE."
231  (setplist (intern file vc-file-prop-obarray) nil))
232
233
234;; We keep properties on each symbol naming a backend as follows:
235;;  * `vc-functions': an alist mapping vc-FUNCTION to vc-BACKEND-FUNCTION.
236
237(defun vc-make-backend-sym (backend sym)
238  "Return BACKEND-specific version of VC symbol SYM."
239  (intern (concat "vc-" (downcase (symbol-name backend))
240		  "-" (symbol-name sym))))
241
242(defun vc-find-backend-function (backend fun)
243  "Return BACKEND-specific implementation of FUN.
244If there is no such implementation, return the default implementation;
245if that doesn't exist either, return nil."
246  (let ((f (vc-make-backend-sym backend fun)))
247    (if (fboundp f) f
248      ;; Load vc-BACKEND.el if needed.
249      (require (intern (concat "vc-" (downcase (symbol-name backend)))))
250      (if (fboundp f) f
251	(let ((def (vc-make-backend-sym 'default fun)))
252	  (if (fboundp def) (cons def backend) nil))))))
253
254(defun vc-call-backend (backend function-name &rest args)
255  "Call for BACKEND the implementation of FUNCTION-NAME with the given ARGS.
256Calls
257
258    (apply 'vc-BACKEND-FUN ARGS)
259
260if vc-BACKEND-FUN exists (after trying to find it in vc-BACKEND.el)
261and else calls
262
263    (apply 'vc-default-FUN BACKEND ARGS)
264
265It is usually called via the `vc-call' macro."
266  (let ((f (assoc function-name (get backend 'vc-functions))))
267    (if f (setq f (cdr f))
268      (setq f (vc-find-backend-function backend function-name))
269      (push (cons function-name f) (get backend 'vc-functions)))
270    (cond
271     ((null f)
272      (error "Sorry, %s is not implemented for %s" function-name backend))
273     ((consp f)	(apply (car f) (cdr f) args))
274     (t		(apply f args)))))
275
276(defmacro vc-call (fun file &rest args)
277  ;; BEWARE!! `file' is evaluated twice!!
278  `(vc-call-backend (vc-backend ,file) ',fun ,file ,@args))
279
280(defsubst vc-parse-buffer (pattern i)
281  "Find PATTERN in the current buffer and return its Ith submatch."
282  (goto-char (point-min))
283  (if (re-search-forward pattern nil t)
284      (match-string i)))
285
286(defun vc-insert-file (file &optional limit blocksize)
287  "Insert the contents of FILE into the current buffer.
288
289Optional argument LIMIT is a regexp.  If present, the file is inserted
290in chunks of size BLOCKSIZE (default 8 kByte), until the first
291occurrence of LIMIT is found.  Anything from the start of that occurrence
292to the end of the buffer is then deleted.  The function returns
293non-nil if FILE exists and its contents were successfully inserted."
294  (erase-buffer)
295  (when (file-exists-p file)
296    (if (not limit)
297        (insert-file-contents file)
298      (if (not blocksize) (setq blocksize 8192))
299      (let ((filepos 0))
300        (while
301	    (and (< 0 (cadr (insert-file-contents
302			     file nil filepos (incf filepos blocksize))))
303		 (progn (beginning-of-line)
304                        (let ((pos (re-search-forward limit nil 'move)))
305                          (if pos (delete-region (match-beginning 0)
306                                                 (point-max)))
307                          (not pos)))))))
308    (set-buffer-modified-p nil)
309    t))
310
311(defun vc-find-root (file witness)
312  "Find the root of a checked out project.
313The function walks up the directory tree from FILE looking for WITNESS.
314If WITNESS if not found, return nil, otherwise return the root."
315  ;; Represent /home/luser/foo as ~/foo so that we don't try to look for
316  ;; witnesses in /home or in /.
317  (setq file (abbreviate-file-name file))
318  (let ((root nil)
319        (user (nth 2 (file-attributes file))))
320    (while (not (or root
321                   (equal file (setq file (file-name-directory file)))
322                   (null file)
323                   ;; As a heuristic, we stop looking up the hierarchy of
324                   ;; directories as soon as we find a directory belonging
325                   ;; to another user.  This should save us from looking in
326                   ;; things like /net and /afs.  This assumes that all the
327                   ;; files inside a project belong to the same user.
328                   (not (equal user (nth 2 (file-attributes file))))
329                   (string-match vc-ignore-dir-regexp file)))
330      (if (file-exists-p (expand-file-name witness file))
331         (setq root file)
332       (setq file (directory-file-name file))))
333    root))
334
335;; Access functions to file properties
336;; (Properties should be _set_ using vc-file-setprop, but
337;; _retrieved_ only through these functions, which decide
338;; if the property is already known or not. A property should
339;; only be retrieved by vc-file-getprop if there is no
340;; access function.)
341
342;; properties indicating the backend being used for FILE
343
344(defun vc-registered (file)
345  "Return non-nil if FILE is registered in a version control system.
346
347This function performs the check each time it is called.  To rely
348on the result of a previous call, use `vc-backend' instead.  If the
349file was previously registered under a certain backend, then that
350backend is tried first."
351  (let (handler)
352    (cond
353     ((string-match vc-ignore-dir-regexp (file-name-directory file)) nil)
354     ((and (boundp 'file-name-handler-alist)
355          (setq handler (find-file-name-handler file 'vc-registered)))
356      ;; handler should set vc-backend and return t if registered
357      (funcall handler 'vc-registered file))
358     (t
359      ;; There is no file name handler.
360      ;; Try vc-BACKEND-registered for each handled BACKEND.
361      (catch 'found
362	(let ((backend (vc-file-getprop file 'vc-backend)))
363	  (mapcar
364	   (lambda (b)
365	     (and (vc-call-backend b 'registered file)
366		  (vc-file-setprop file 'vc-backend b)
367		  (throw 'found t)))
368	   (if (or (not backend) (eq backend 'none))
369	       vc-handled-backends
370	     (cons backend vc-handled-backends))))
371        ;; File is not registered.
372        (vc-file-setprop file 'vc-backend 'none)
373        nil)))))
374
375(defun vc-backend (file)
376  "Return the version control type of FILE, nil if it is not registered."
377  ;; `file' can be nil in several places (typically due to the use of
378  ;; code like (vc-backend buffer-file-name)).
379  (when (stringp file)
380    (let ((property (vc-file-getprop file 'vc-backend)))
381      ;; Note that internally, Emacs remembers unregistered
382      ;; files by setting the property to `none'.
383      (cond ((eq property 'none) nil)
384	    (property)
385	    ;; vc-registered sets the vc-backend property
386	    (t (if (vc-registered file)
387		   (vc-file-getprop file 'vc-backend)
388		 nil))))))
389
390(defun vc-backend-subdirectory-name (file)
391  "Return where the master and lock FILEs for the current directory are kept."
392  (symbol-name (vc-backend file)))
393
394(defun vc-name (file)
395  "Return the master name of FILE.
396If the file is not registered, or the master name is not known, return nil."
397  ;; TODO: This should ultimately become obsolete, at least up here
398  ;; in vc-hooks.
399  (or (vc-file-getprop file 'vc-name)
400      ;; force computation of the property by calling
401      ;; vc-BACKEND-registered explicitly
402      (if (and (vc-backend file)
403	       (vc-call-backend (vc-backend file) 'registered file))
404	  (vc-file-getprop file 'vc-name))))
405
406(defun vc-checkout-model (file)
407  "Indicate how FILE is checked out.
408
409If FILE is not registered, this function always returns nil.
410For registered files, the possible values are:
411
412  'implicit   FILE is always writeable, and checked out `implicitly'
413              when the user saves the first changes to the file.
414
415  'locking    FILE is read-only if up-to-date; user must type
416              \\[vc-next-action] before editing.  Strict locking
417              is assumed.
418
419  'announce   FILE is read-only if up-to-date; user must type
420              \\[vc-next-action] before editing.  But other users
421              may be editing at the same time."
422  (or (vc-file-getprop file 'vc-checkout-model)
423      (if (vc-backend file)
424          (vc-file-setprop file 'vc-checkout-model
425                           (vc-call checkout-model file)))))
426
427(defun vc-user-login-name (file)
428  "Return the name under which the user accesses the given FILE."
429  (or (and (eq (string-match tramp-file-name-regexp file) 0)
430           ;; tramp case: execute "whoami" via tramp
431           (let ((default-directory (file-name-directory file)))
432             (with-temp-buffer
433               (if (not (zerop (process-file "whoami" nil t)))
434                   ;; fall through if "whoami" didn't work
435                   nil
436                 ;; remove trailing newline
437                 (delete-region (1- (point-max)) (point-max))
438                 (buffer-string)))))
439      ;; normal case
440      (user-login-name)
441      ;; if user-login-name is nil, return the UID as a string
442      (number-to-string (user-uid))))
443
444(defun vc-state (file)
445  "Return the version control state of FILE.
446
447If FILE is not registered, this function always returns nil.
448For registered files, the value returned is one of:
449
450  'up-to-date        The working file is unmodified with respect to the
451                     latest version on the current branch, and not locked.
452
453  'edited            The working file has been edited by the user.  If
454                     locking is used for the file, this state means that
455                     the current version is locked by the calling user.
456
457  USER               The current version of the working file is locked by
458                     some other USER (a string).
459
460  'needs-patch       The file has not been edited by the user, but there is
461                     a more recent version on the current branch stored
462                     in the master file.
463
464  'needs-merge       The file has been edited by the user, and there is also
465                     a more recent version on the current branch stored in
466                     the master file.  This state can only occur if locking
467                     is not used for the file.
468
469  'unlocked-changes  The current version of the working file is not locked,
470                     but the working file has been changed with respect
471                     to that version.  This state can only occur for files
472                     with locking; it represents an erroneous condition that
473                     should be resolved by the user (vc-next-action will
474                     prompt the user to do it)."
475  ;; FIXME: New (sub)states needed (?):
476  ;; - `added' (i.e. `edited' but with no base version yet,
477  ;;            typically represented by vc-workfile-version = "0")
478  ;; - `conflict' (i.e. `edited' with conflict markers)
479  ;; - `removed'
480  ;; - `copied' and `moved' (might be handled by `removed' and `added')
481  (or (vc-file-getprop file 'vc-state)
482      (if (vc-backend file)
483          (vc-file-setprop file 'vc-state
484                           (vc-call state-heuristic file)))))
485
486(defun vc-recompute-state (file)
487  "Recompute the version control state of FILE, and return it.
488This calls the possibly expensive function vc-BACKEND-state,
489rather than the heuristic."
490  (vc-file-setprop file 'vc-state (vc-call state file)))
491
492(defsubst vc-up-to-date-p (file)
493  "Convenience function that checks whether `vc-state' of FILE is `up-to-date'."
494  (eq (vc-state file) 'up-to-date))
495
496(defun vc-default-state-heuristic (backend file)
497  "Default implementation of vc-state-heuristic.
498It simply calls the real state computation function `vc-BACKEND-state'
499and does not employ any heuristic at all."
500   (vc-call-backend backend 'state file))
501
502(defun vc-workfile-unchanged-p (file)
503  "Return non-nil if FILE has not changed since the last checkout."
504  (let ((checkout-time (vc-file-getprop file 'vc-checkout-time))
505        (lastmod (nth 5 (file-attributes file))))
506    (if (and checkout-time
507             ;; Tramp and Ange-FTP return this when they don't know the time.
508             (not (equal lastmod '(0 0))))
509        (equal checkout-time lastmod)
510      (let ((unchanged (vc-call workfile-unchanged-p file)))
511        (vc-file-setprop file 'vc-checkout-time (if unchanged lastmod 0))
512        unchanged))))
513
514(defun vc-default-workfile-unchanged-p (backend file)
515  "Check if FILE is unchanged by diffing against the master version.
516Return non-nil if FILE is unchanged."
517  (zerop (condition-case err
518             ;; If the implementation supports it, let the output
519             ;; go to *vc*, not *vc-diff*, since this is an internal call.
520             (vc-call diff file nil nil "*vc*")
521           (wrong-number-of-arguments
522            ;; If this error came from the above call to vc-BACKEND-diff,
523            ;; try again without the optional buffer argument (for
524            ;; backward compatibility).  Otherwise, resignal.
525            (if (or (not (eq (cadr err)
526                             (indirect-function
527                              (vc-find-backend-function (vc-backend file)
528                                                        'diff))))
529                    (not (eq (caddr err) 4)))
530                (signal (car err) (cdr err))
531              (vc-call diff file))))))
532
533(defun vc-workfile-version (file)
534  "Return the version level of the current workfile FILE.
535If FILE is not registered, this function always returns nil."
536  (or (vc-file-getprop file 'vc-workfile-version)
537      (if (vc-backend file)
538          (vc-file-setprop file 'vc-workfile-version
539                           (vc-call workfile-version file)))))
540
541(defun vc-default-registered (backend file)
542  "Check if FILE is registered in BACKEND using vc-BACKEND-master-templates."
543  (let ((sym (vc-make-backend-sym backend 'master-templates)))
544    (unless (get backend 'vc-templates-grabbed)
545      (put backend 'vc-templates-grabbed t)
546      (set sym (append (delq nil
547			     (mapcar
548			      (lambda (template)
549				(and (consp template)
550				     (eq (cdr template) backend)
551				     (car template)))
552                              (with-no-warnings
553                               vc-master-templates)))
554		       (symbol-value sym))))
555    (let ((result (vc-check-master-templates file (symbol-value sym))))
556      (if (stringp result)
557	  (vc-file-setprop file 'vc-name result)
558	nil))))				; Not registered
559
560(defun vc-possible-master (s dirname basename)
561  (cond
562   ((stringp s) (format s dirname basename))
563   ((functionp s)
564    ;; The template is a function to invoke.  If the
565    ;; function returns non-nil, that means it has found a
566    ;; master.  For backward compatibility, we also handle
567    ;; the case that the function throws a 'found atom
568    ;; and a pair (cons MASTER-FILE BACKEND).
569    (let ((result (catch 'found (funcall s dirname basename))))
570      (if (consp result) (car result) result)))))
571
572(defun vc-check-master-templates (file templates)
573  "Return non-nil if there is a master corresponding to FILE.
574
575TEMPLATES is a list of strings or functions.  If an element is a
576string, it must be a control string as required by `format', with two
577string placeholders, such as \"%sRCS/%s,v\".  The directory part of
578FILE is substituted for the first placeholder, the basename of FILE
579for the second.  If a file with the resulting name exists, it is taken
580as the master of FILE, and returned.
581
582If an element of TEMPLATES is a function, it is called with the
583directory part and the basename of FILE as arguments.  It should
584return non-nil if it finds a master; that value is then returned by
585this function."
586  (let ((dirname (or (file-name-directory file) ""))
587        (basename (file-name-nondirectory file)))
588    (catch 'found
589      (mapcar
590       (lambda (s)
591	 (let ((trial (vc-possible-master s dirname basename)))
592	   (if (and trial (file-exists-p trial)
593		    ;; Make sure the file we found with name
594		    ;; TRIAL is not the source file itself.
595		    ;; That can happen with RCS-style names if
596		    ;; the file name is truncated (e.g. to 14
597		    ;; chars).  See if either directory or
598		    ;; attributes differ.
599		    (or (not (string= dirname
600				      (file-name-directory trial)))
601			(not (equal (file-attributes file)
602				    (file-attributes trial)))))
603	       (throw 'found trial))))
604       templates))))
605
606(defun vc-toggle-read-only (&optional verbose)
607  "Change read-only status of current buffer, perhaps via version control.
608
609If the buffer is visiting a file registered with version control,
610then check the file in or out.  Otherwise, just change the read-only flag
611of the buffer.
612With prefix argument, ask for version number to check in or check out.
613Check-out of a specified version number does not lock the file;
614to do that, use this command a second time with no argument.
615
616If you bind this function to \\[toggle-read-only], then Emacs checks files
617in or out whenever you toggle the read-only flag."
618  (interactive "P")
619  (if (or (and (boundp 'vc-dired-mode) vc-dired-mode)
620	  ;; use boundp because vc.el might not be loaded
621	  (vc-backend buffer-file-name))
622      (vc-next-action verbose)
623    (toggle-read-only)))
624
625(defun vc-default-make-version-backups-p (backend file)
626  "Return non-nil if unmodified versions should be backed up locally.
627The default is to switch off this feature."
628  nil)
629
630(defun vc-version-backup-file-name (file &optional rev manual regexp)
631  "Return a backup file name for REV or the current version of FILE.
632If MANUAL is non-nil it means that a name for backups created by
633the user should be returned; if REGEXP is non-nil that means to return
634a regexp for matching all such backup files, regardless of the version."
635  (if regexp
636      (concat (regexp-quote (file-name-nondirectory file))
637              "\\.~.+" (unless manual "\\.") "~")
638    (expand-file-name (concat (file-name-nondirectory file)
639                              ".~" (subst-char-in-string
640                                    ?/ ?_ (or rev (vc-workfile-version file)))
641                              (unless manual ".") "~")
642                      (file-name-directory file))))
643
644(defun vc-delete-automatic-version-backups (file)
645  "Delete all existing automatic version backups for FILE."
646  (condition-case nil
647      (mapcar
648       'delete-file
649       (directory-files (or (file-name-directory file) default-directory) t
650			(vc-version-backup-file-name file nil nil t)))
651    ;; Don't fail when the directory doesn't exist.
652    (file-error nil)))
653
654(defun vc-make-version-backup (file)
655  "Make a backup copy of FILE, which is assumed in sync with the repository.
656Before doing that, check if there are any old backups and get rid of them."
657  (unless (and (fboundp 'msdos-long-file-names)
658               (not (with-no-warnings (msdos-long-file-names))))
659    (vc-delete-automatic-version-backups file)
660    (condition-case nil
661        (copy-file file (vc-version-backup-file-name file)
662                   nil 'keep-date)
663      ;; It's ok if it doesn't work (e.g. directory not writable),
664      ;; since this is just for efficiency.
665      (file-error
666       (message
667        (concat "Warning: Cannot make version backup; "
668                "diff/revert therefore not local"))))))
669
670(defun vc-before-save ()
671  "Function to be called by `basic-save-buffer' (in files.el)."
672  ;; If the file on disk is still in sync with the repository,
673  ;; and version backups should be made, copy the file to
674  ;; another name.  This enables local diffs and local reverting.
675  (let ((file buffer-file-name))
676    (and (vc-backend file)
677	 (vc-up-to-date-p file)
678	 (eq (vc-checkout-model file) 'implicit)
679	 (vc-call make-version-backups-p file)
680         (vc-make-version-backup file))))
681
682(defun vc-after-save ()
683  "Function to be called by `basic-save-buffer' (in files.el)."
684  ;; If the file in the current buffer is under version control,
685  ;; up-to-date, and locking is not used for the file, set
686  ;; the state to 'edited and redisplay the mode line.
687  (let ((file buffer-file-name))
688    (and (vc-backend file)
689	 (or (and (equal (vc-file-getprop file 'vc-checkout-time)
690			 (nth 5 (file-attributes file)))
691		  ;; File has been saved in the same second in which
692		  ;; it was checked out.  Clear the checkout-time
693		  ;; to avoid confusion.
694		  (vc-file-setprop file 'vc-checkout-time nil))
695	     t)
696         (vc-up-to-date-p file)
697         (eq (vc-checkout-model file) 'implicit)
698         (vc-file-setprop file 'vc-state 'edited)
699	 (vc-mode-line file)
700	 (if (featurep 'vc)
701	     ;; If VC is not loaded, then there can't be
702	     ;; any VC Dired buffer to synchronize.
703	     (vc-dired-resynch-file file)))))
704
705(defun vc-mode-line (file)
706  "Set `vc-mode' to display type of version control for FILE.
707The value is set in the current buffer, which should be the buffer
708visiting FILE."
709  (interactive (list buffer-file-name))
710  (let ((backend (vc-backend file)))
711    (if (not backend)
712	(setq vc-mode nil)
713      (setq vc-mode (concat " " (if vc-display-status
714				    (vc-call mode-line-string file)
715				  (symbol-name backend))))
716      ;; If the file is locked by some other user, make
717      ;; the buffer read-only.  Like this, even root
718      ;; cannot modify a file that someone else has locked.
719      (and (equal file buffer-file-name)
720	   (stringp (vc-state file))
721	   (setq buffer-read-only t))
722      ;; If the user is root, and the file is not owner-writable,
723      ;; then pretend that we can't write it
724      ;; even though we can (because root can write anything).
725    ;; This way, even root cannot modify a file that isn't locked.
726    (and (equal file buffer-file-name)
727	 (not buffer-read-only)
728	   (zerop (user-real-uid))
729	   (zerop (logand (file-modes buffer-file-name) 128))
730	   (setq buffer-read-only t)))
731    (force-mode-line-update)
732    backend))
733
734(defun vc-default-mode-line-string (backend file)
735  "Return string for placement in modeline by `vc-mode-line' for FILE.
736Format:
737
738  \"BACKEND-REV\"        if the file is up-to-date
739  \"BACKEND:REV\"        if the file is edited (or locked by the calling user)
740  \"BACKEND:LOCKER:REV\" if the file is locked by somebody else
741
742This function assumes that the file is registered."
743  (setq backend (symbol-name backend))
744  (let ((state   (vc-state file))
745	(rev     (vc-workfile-version file)))
746    (cond ((or (eq state 'up-to-date)
747	       (eq state 'needs-patch))
748	   (concat backend "-" rev))
749          ((stringp state)
750	   (concat backend ":" state ":" rev))
751          (t
752           ;; Not just for the 'edited state, but also a fallback
753           ;; for all other states.  Think about different symbols
754           ;; for 'needs-patch and 'needs-merge.
755           (concat backend ":" rev)))))
756
757(defun vc-follow-link ()
758  "If current buffer visits a symbolic link, visit the real file.
759If the real file is already visited in another buffer, make that buffer
760current, and kill the buffer that visits the link."
761  (let* ((truename (abbreviate-file-name (file-chase-links buffer-file-name)))
762         (true-buffer (find-buffer-visiting truename))
763	 (this-buffer (current-buffer)))
764    (if (eq true-buffer this-buffer)
765	(progn
766	  (kill-buffer this-buffer)
767	  ;; In principle, we could do something like set-visited-file-name.
768	  ;; However, it can't be exactly the same as set-visited-file-name.
769	  ;; I'm not going to work out the details right now. -- rms.
770	  (set-buffer (find-file-noselect truename)))
771      (set-buffer true-buffer)
772      (kill-buffer this-buffer))))
773
774(defun vc-default-find-file-hook (backend)
775  nil)
776
777(defun vc-find-file-hook ()
778  "Function for `find-file-hook' activating VC mode if appropriate."
779  ;; Recompute whether file is version controlled,
780  ;; if user has killed the buffer and revisited.
781  (if vc-mode
782      (setq vc-mode nil))
783  (when buffer-file-name
784    (vc-file-clearprops buffer-file-name)
785    (cond
786     ((vc-backend buffer-file-name)
787      ;; Compute the state and put it in the modeline.
788      (vc-mode-line buffer-file-name)
789      (unless vc-make-backup-files
790	;; Use this variable, not make-backup-files,
791	;; because this is for things that depend on the file name.
792	(set (make-local-variable 'backup-inhibited) t))
793      ;; Let the backend setup any buffer-local things he needs.
794      (vc-call-backend (vc-backend buffer-file-name) 'find-file-hook))
795     ((let ((link-type (and (file-symlink-p buffer-file-name)
796			    (vc-backend (file-chase-links buffer-file-name)))))
797	(cond ((not link-type) nil)	;Nothing to do.
798	      ((eq vc-follow-symlinks nil)
799	       (message
800        "Warning: symbolic link to %s-controlled source file" link-type))
801	      ((or (not (eq vc-follow-symlinks 'ask))
802		   ;; If we already visited this file by following
803		   ;; the link, don't ask again if we try to visit
804		   ;; it again.  GUD does that, and repeated questions
805		   ;; are painful.
806		   (get-file-buffer
807		    (abbreviate-file-name
808		     (file-chase-links buffer-file-name))))
809
810	       (vc-follow-link)
811	       (message "Followed link to %s" buffer-file-name)
812	       (vc-find-file-hook))
813	      (t
814	       (if (yes-or-no-p (format
815        "Symbolic link to %s-controlled source file; follow link? " link-type))
816		   (progn (vc-follow-link)
817			  (message "Followed link to %s" buffer-file-name)
818			  (vc-find-file-hook))
819		 (message
820        "Warning: editing through the link bypasses version control")
821		 ))))))))
822
823(add-hook 'find-file-hook 'vc-find-file-hook)
824
825;; more hooks, this time for file-not-found
826(defun vc-file-not-found-hook ()
827  "When file is not found, try to check it out from version control.
828Returns t if checkout was successful, nil otherwise.
829Used in `find-file-not-found-functions'."
830  ;; When a file does not exist, ignore cached info about it
831  ;; from a previous visit.
832  (vc-file-clearprops buffer-file-name)
833  (let ((backend (vc-backend buffer-file-name)))
834    (if backend (vc-call-backend backend 'find-file-not-found-hook))))
835
836(defun vc-default-find-file-not-found-hook (backend)
837  (if (yes-or-no-p
838       (format "File %s was lost; check out from version control? "
839	       (file-name-nondirectory buffer-file-name)))
840      (save-excursion
841	(require 'vc)
842	(setq default-directory (file-name-directory buffer-file-name))
843	(not (vc-error-occurred (vc-checkout buffer-file-name))))))
844
845(add-hook 'find-file-not-found-functions 'vc-file-not-found-hook)
846
847(defun vc-kill-buffer-hook ()
848  "Discard VC info about a file when we kill its buffer."
849  (if buffer-file-name
850      (vc-file-clearprops buffer-file-name)))
851
852(add-hook 'kill-buffer-hook 'vc-kill-buffer-hook)
853
854;; Now arrange for (autoloaded) bindings of the main package.
855;; Bindings for this have to go in the global map, as we'll often
856;; want to call them from random buffers.
857
858;; Autoloading works fine, but it prevents shortcuts from appearing
859;; in the menu because they don't exist yet when the menu is built.
860;; (autoload 'vc-prefix-map "vc" nil nil 'keymap)
861(defvar vc-prefix-map
862  (let ((map (make-sparse-keymap)))
863    (define-key map "a" 'vc-update-change-log)
864    (define-key map "b" 'vc-switch-backend)
865    (define-key map "c" 'vc-cancel-version)
866    (define-key map "d" 'vc-directory)
867    (define-key map "g" 'vc-annotate)
868    (define-key map "h" 'vc-insert-headers)
869    (define-key map "i" 'vc-register)
870    (define-key map "l" 'vc-print-log)
871    (define-key map "m" 'vc-merge)
872    (define-key map "r" 'vc-retrieve-snapshot)
873    (define-key map "s" 'vc-create-snapshot)
874    (define-key map "u" 'vc-revert-buffer)
875    (define-key map "v" 'vc-next-action)
876    (define-key map "=" 'vc-diff)
877    (define-key map "~" 'vc-version-other-window)
878    map))
879(fset 'vc-prefix-map vc-prefix-map)
880(define-key global-map "\C-xv" 'vc-prefix-map)
881
882(if (not (boundp 'vc-menu-map))
883    ;; Don't do the menu bindings if menu-bar.el wasn't loaded to defvar
884    ;; vc-menu-map.
885    ()
886  ;;(define-key vc-menu-map [show-files]
887  ;;  '("Show Files under VC" . (vc-directory t)))
888  (define-key vc-menu-map [vc-retrieve-snapshot]
889    '("Retrieve Snapshot" . vc-retrieve-snapshot))
890  (define-key vc-menu-map [vc-create-snapshot]
891    '("Create Snapshot" . vc-create-snapshot))
892  (define-key vc-menu-map [vc-directory] '("VC Directory Listing" . vc-directory))
893  (define-key vc-menu-map [separator1] '("----"))
894  (define-key vc-menu-map [vc-annotate] '("Annotate" . vc-annotate))
895  (define-key vc-menu-map [vc-rename-file] '("Rename File" . vc-rename-file))
896  (define-key vc-menu-map [vc-version-other-window]
897    '("Show Other Version" . vc-version-other-window))
898  (define-key vc-menu-map [vc-diff] '("Compare with Base Version" . vc-diff))
899  (define-key vc-menu-map [vc-update-change-log]
900    '("Update ChangeLog" . vc-update-change-log))
901  (define-key vc-menu-map [vc-print-log] '("Show History" . vc-print-log))
902  (define-key vc-menu-map [separator2] '("----"))
903  (define-key vc-menu-map [vc-insert-header]
904    '("Insert Header" . vc-insert-headers))
905  (define-key vc-menu-map [undo] '("Undo Last Check-In" . vc-cancel-version))
906  (define-key vc-menu-map [vc-revert-buffer]
907    '("Revert to Base Version" . vc-revert-buffer))
908  (define-key vc-menu-map [vc-update]
909    '("Update to Latest Version" . vc-update))
910  (define-key vc-menu-map [vc-next-action] '("Check In/Out" . vc-next-action))
911  (define-key vc-menu-map [vc-register] '("Register" . vc-register)))
912
913;; These are not correct and it's not currently clear how doing it
914;; better (with more complicated expressions) might slow things down
915;; on older systems.
916
917;;(put 'vc-rename-file 'menu-enable 'vc-mode)
918;;(put 'vc-annotate 'menu-enable '(eq (vc-buffer-backend) 'CVS))
919;;(put 'vc-version-other-window 'menu-enable 'vc-mode)
920;;(put 'vc-diff 'menu-enable 'vc-mode)
921;;(put 'vc-update-change-log 'menu-enable
922;;     '(member (vc-buffer-backend) '(RCS CVS)))
923;;(put 'vc-print-log 'menu-enable 'vc-mode)
924;;(put 'vc-cancel-version 'menu-enable 'vc-mode)
925;;(put 'vc-revert-buffer 'menu-enable 'vc-mode)
926;;(put 'vc-insert-headers 'menu-enable 'vc-mode)
927;;(put 'vc-next-action 'menu-enable 'vc-mode)
928;;(put 'vc-register 'menu-enable '(and buffer-file-name (not vc-mode)))
929
930(provide 'vc-hooks)
931
932;; arch-tag: 2e5a6fa7-1d30-48e2-8bd0-e3d335f04f32
933;;; vc-hooks.el ends here
934