| blob | 081c232243a60ebe0d91f916c0221271158b53b1 |
1 ;;; vc.el --- drive a version-control system from within Emacs
3 ;; Copyright (C) 1992,93,94,95,96,97,98,2000 Free Software Foundation, Inc.
5 ;; Author: FSF (see below for full credits)
6 ;; Maintainer: Andre Spiegel <spiegel@gnu.org>
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
13 ;; any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
25 ;;; Credits:
27 ;; VC was initially designed and implemented by Eric S. Raymond
28 ;; <esr@snark.thyrsus.com>. Over the years, many people have
29 ;; contributed substantial amounts of work to VC. These include:
30 ;; Per Cederqvist <ceder@lysator.liu.se>
31 ;; Paul Eggert <eggert@twinsun.com>
32 ;; Sebastian Kremer <sk@thp.uni-koeln.de>
33 ;; Martin Lorentzson <martinl@gnu.org>
34 ;; Dave Love <d.love@gnu.org>
35 ;; Stefan Monnier <monnier@cs.yale.edu>
36 ;; Andre Spiegel <spiegel@gnu.org>
37 ;; Richard Stallman <rms@gnu.org>
38 ;; ttn@netcom.com
40 ;;; Commentary:
42 ;; This mode is fully documented in the Emacs user's manual.
43 ;;
44 ;; Supported version-control systems presently include SCCS, RCS, and CVS.
45 ;;
46 ;; Some features will not work with old RCS versions. Where
47 ;; appropriate, VC finds out which version you have, and allows or
48 ;; disallows those features (stealing locks, for example, works only
49 ;; from 5.6.2 onwards).
50 ;; Even initial checkins will fail if your RCS version is so old that ci
51 ;; doesn't understand -t-; this has been known to happen to people running
52 ;; NExTSTEP 3.0.
53 ;;
54 ;; You can support the RCS -x option by customizing vc-rcs-master-templates.
55 ;;
56 ;; Proper function of the SCCS diff commands requires the shellscript vcdiff
57 ;; to be installed somewhere on Emacs's path for executables.
58 ;;
59 ;; If your site uses the ChangeLog convention supported by Emacs, the
60 ;; function vc-comment-to-change-log should prove a useful checkin hook.
61 ;;
62 ;; The vc code maintains some internal state in order to reduce expensive
63 ;; version-control operations to a minimum. Some names are only computed
64 ;; once. If you perform version control operations with RCS/SCCS/CVS while
65 ;; vc's back is turned, or move/rename master files while vc is running,
66 ;; vc may get seriously confused. Don't do these things!
67 ;;
68 ;; Developer's notes on some concurrency issues are included at the end of
69 ;; the file.
71 ;;; Code:
73 ;;;;;;;;;;;;;;;;; Backend-specific functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
74 ;;
75 ;; for each operation FUN, the backend should provide a function vc-BACKEND-FUN.
76 ;; Operations marked with a `-' instead of a `*' have a sensible default
77 ;; behavior.
79 ;; * registered (file)
80 ;; * state (file)
81 ;; - state-heuristic (file)
82 ;; The default behavior delegates to `state'.
83 ;; - dir-state (dir)
84 ;; * checkout-model (file)
85 ;; - mode-line-string (file)
86 ;; * workfile-version (file)
87 ;; * revert (file)
88 ;; - merge-news (file)
89 ;; Only needed if state `needs-merge' is possible.
90 ;; - merge (file rev1 rev2)
91 ;; - steal-lock (file &optional version)
92 ;; Only required if files can be locked by somebody else.
93 ;; * register (file rev comment)
94 ;; - responsible-p (file)
95 ;; Should also work if FILE is a directory (ends with a slash).
96 ;; - could-register (file)
97 ;; * checkout (file writable &optional rev destfile)
98 ;; Checkout revision REV of FILE into DESTFILE.
99 ;; DESTFILE defaults to FILE.
100 ;; The file should be made writable if WRITABLE is non-nil.
101 ;; REV can be nil (BASE) or "" (HEAD) or any other revision.
102 ;; * checkin (file rev comment)
103 ;; - logentry-check ()
104 ;; * diff (file &optional rev1 rev2)
105 ;; Insert the diff for FILE into the current buffer.
106 ;; REV1 should default to workfile-version.
107 ;; REV2 should default to the current workfile
108 ;; Return a status of either 0 (i.e. no diff) or 1 (i.e. either non-empty
109 ;; diff or the diff is run asynchronously).
110 ;; - workfile-unchanged-p (file)
111 ;; Return non-nil if FILE is unchanged from its current workfile version.
112 ;; This function should do a brief comparison of FILE's contents
113 ;; with those of the master version. If the backend does not have
114 ;; such a brief-comparison feature, the default implementation of this
115 ;; function can be used, which delegates to a full vc-BACKEND-diff.
116 ;; - clear-headers ()
117 ;; * check-headers ()
118 ;; - dired-state-info (file)
119 ;; - create-snapshot (dir name branchp)
120 ;; Take a snapshot of the current state of files under DIR and name it NAME.
121 ;; This should make sure that files are up-to-date before proceeding
122 ;; with the action.
123 ;; DIR can also be a file and if BRANCHP is specified, NAME
124 ;; should be created as a branch and DIR should be checked out under
125 ;; this new branch. The default behavior does not support branches
126 ;; but does a sanity check, a tree traversal and for each file calls
127 ;; `assign-name'.
128 ;; * assign-name (file name)
129 ;; Give name NAME to the current version of FILE, assuming it is
130 ;; up-to-date. Only used by the default version of `create-snapshot'.
131 ;; - retrieve-snapshot (dir name update)
132 ;; Retrieve a named snapshot of all registered files at or below DIR.
133 ;; If UPDATE is non-nil, then update buffers of any files in the snapshot
134 ;; that are currently visited.
135 ;; * print-log (file)
136 ;; Insert the revision log of FILE into the current buffer.
137 ;; - show-log-entry (version)
138 ;; - update-changelog (files)
139 ;; Find changelog entries for FILES, or for all files at or below
140 ;; the default-directory if FILES is nil.
141 ;; * latest-on-branch-p (file)
142 ;; - cancel-version (file writable)
143 ;; - rename-file (old new)
144 ;; - annotate-command (file buf)
145 ;; - annotate-difference (pos)
146 ;; Only required if `annotate-command' is defined for the backend.
158 minor-mode-alist)))
160 ;; General customization
163 "Version-control system in Emacs."
167 "*If non-nil, treat user as expert; suppress yes-no prompts on some things."
172 "*If non-nil, delete the *VC-log* buffer and window after each logical action.
173 If nil, bury that buffer instead.
174 This is most useful if you have multiple windows on a frame and would like to
175 preserve the setting."
180 "*If non-nil, prompt for initial comment when a file is registered."
185 "*A string used as the default version number when a new file is registered.
192 "*If non-nil, display run messages from back-end commands."
197 "*A string or list of strings specifying extra switches for checkin.
203 string))
207 "*A string or list of strings specifying extra switches for checkout.
213 string))
217 "*A string or list of strings; extra switches for registering a file.
223 string))
227 "*Switches passed to `ls' for vc-dired. MUST contain the `l' option."
233 "*If non-nil, show directory trees recursively in VC Dired."
239 "*If non-nil, show only locked files in VC Dired."
245 "*List of directory names to be ignored while recursively walking file trees."
252 ;;; This is duplicated in diff.el.
256 ;;;###autoload
258 "*Normal hook (list of functions) run after a checkin is done.
259 See `run-hooks'."
264 ;;;###autoload
266 "*Normal hook (list of functions) run before a file gets checked in.
267 See `run-hooks'."
272 "*Normal hook run by `vc-backend-logentry-check'.
273 Use this to impose your own rules on the entry in addition to any the
274 version control backend imposes itself."
278 ;; Annotate customization
298 Ages are given in units of 2**-16 seconds.
299 Default is eighteen steps using a twenty day increment."
304 "*Color for lines older than CAR of last cons in `vc-annotate-color-map'."
310 Default color is used if nil."
315 "*Menu elements for the mode-specific menu of VC-Annotate mode.
316 List of factors, used to expand/compress the time scale. See `vc-annotate'."
320 ;; vc-annotate functionality (CVS only).
327 m)
333 ;; Header-insertion hair
338 "*Associate static header string templates with file types.
339 A \%s in the template is replaced with the first string associated with
340 the file's version control type in `vc-header-alist'."
348 "*Special comment delimiters to be used in generating vc headers only.
349 Add an entry in this list if you need to override the normal `comment-start'
350 and `comment-end' variables. This will only be necessary if the mode language
351 is sensitive to blank lines."
358 ;; Default is to be extra careful for super-user.
359 ;; TODO: This variable is no longer used; the corresponding checks
360 ;; are always done now. If that turns out to be fast enough,
361 ;; the variable can be obsoleted.
363 "*Non-nil means be extra-careful in checkout.
364 Verify that the file really is not locked
365 and that its contents match what the master file says."
369 \f
370 ;;; The main keymap
388 map))
391 ;; Initialization code, to be done just once at load-time
399 map))
400 ;; Compatibility with old name. Should we bother ?
403 \f
404 ;; Variables the user doesn't need to know about.
410 ;; In a log entry buffer, this is a local variable
411 ;; that points to the buffer for which it was made
412 ;; (either a file, or a VC dired buffer).
428 ;;; functions that operate on RCS revision numbers. This code should
429 ;;; also be moved into the backends. It stays for now, however, since
430 ;;; it is used in code below.
432 "Return t if REV is a revision on the trunk."
436 "Return t if REV is a branch revision."
440 "Return the branch part of a revision number REV."
444 "Return the minor version number of a revision number REV."
449 "Guess the version number immediately preceding REV."
453 ;; version does probably not start a branch or release
456 ;; we are at the beginning of the trunk --
457 ;; don't know anything to return here
458 ""
459 ;; we are at the beginning of a branch --
460 ;; return version of starting point
463 ;; File property caching
466 "Clear all cached file properties and the comment ring."
469 ;; Note: there is potential for minor lossage here if there is an open
470 ;; log buffer with a nonzero local value of vc-comment-ring-index.
474 "Execute FORM, then set per-file properties for FILE, but only those
475 that have not been set during the execution of FORM. SETTINGS is a list
476 of two-element lists, each of which has the form (PROPERTY VALUE)."
479 ,form
485 property value))))
488 ;; Random helper functions
495 ;;; Two macros for elisp programming
496 ;;;###autoload
498 "Check out a writable copy of FILE if necessary and execute the body.
499 Check in FILE with COMMENT (a string) after BODY has been executed.
500 FILE is passed through `expand-file-name'; BODY executed within
501 `save-excursion'. If FILE is not under version control, or locked by
502 somebody else, signal error."
514 ;;;###autoload
516 "Edit FILE under version control, executing body.
517 Checkin with COMMENT after executing BODY.
518 This macro uses `with-vc-file', passing args to it.
519 However, before executing BODY, find FILE, and after BODY, save buffer."
523 ,@body
527 "Make sure that the current buffer visits a version-controlled file."
544 "An alternative output filter for async process P.
545 The only difference with the default filter is to insert S after markers."
554 "Prepare BUF for executing a VC command and make it the current buffer.
569 "Eval CODE when the current buffer's process is done.
570 If the current buffer has no process, just evaluate CODE.
571 Else, add CODE to the process' sentinel."
574 ;; If there's no background process, just execute the code.
576 ;; If the background process has exited, reap it and try again
580 ;; If a process is running, add CODE to the sentinel
588 ; (goto-char...)'
590 sentinel))))))
593 nil)
596 "Hook run at the end of `vc-do-command'.
597 Each function is called inside the buffer in which the command was run
601 "Execute a version control command, notifying user and checking for errors.
602 Output from COMMAND goes to BUFFER, or *vc* if BUFFER is nil or the current
603 buffer (which is assumed to be properly setup) if BUFFER is t. The
604 command is considered successful if its exit status does not exceed
605 OKSTATUS (if OKSTATUS is nil, that means to ignore errors, if it is 'async,
606 that means not to wait for termination of the subprocess). FILE is
607 the name of the working file (may also be nil, to execute commands
608 that don't expect a file name). If an optional list of FLAGS is present,
609 that is inserted into the command line before the filename."
620 ;; FIXME: file-relative-name can return a bogus result because
621 ;; it doesn't look at the actual file-system to see if symlinks
622 ;; come into play.
625 ;; Add vc-path to PATH for the execution of this command.
628 path-separator
630 process-environment))
634 squeezed)))
636 ;;(set-process-sentinel proc (lambda (p msg) (delete-process p)))
651 status)))
654 "Save a bit of the text around POSN in the current buffer.
655 Used to help us find the corresponding position again later
656 if markers are destroyed or corrupted."
657 ;; A lot of this was shamelessly lifted from Sebastian Kremer's
658 ;; rcs.el mode.
665 "Return the position of CONTEXT in the current buffer, or nil if not found."
674 ;; Can't use search-backward since the match may continue
675 ;; after point.
677 ;; goto-char doesn't signal an error at
678 ;; beginning of buffer like backward-char would
680 ;; to beginning of OSTRING
684 "Return t if POSN matches CONTEXT, nil otherwise."
689 nil
693 "Return a list (POINT-CONTEXT MARK-CONTEXT REPARSE).
694 Used by `vc-restore-buffer-context' to later restore the context."
696 ;; Use mark-marker to avoid confusion in transient-mark-mode.
699 ;; Make the right thing happen in transient-mark-mode.
701 ;; We may want to reparse the compilation buffer after revert
704 ;; Construct a list; each elt is nil or a buffer
705 ;; iff that buffer is a compilation output buffer
706 ;; that contains markers into the current buffer.
711 compilation-old-error-list
712 compilation-error-list))
727 "Restore point/mark, and reparse any affected compilation buffers.
728 CONTEXT is that which `vc-buffer-context' returns."
732 ;; Reparse affected compilation buffers.
737 ;; Record the position in the compilation buffer of
738 ;; the last error next-error went to.
741 ;; Reparse the error messages as far as they were parsed before.
743 ;; Move the pointer up to find the error we were at before
744 ;; reparsing. Now next-error should properly go to the next one.
750 ;; if necessary, restore point and mark
755 mark-context
761 "Revert buffer, trying to keep point and mark where user expects them.
762 Tries to be clever in the face of changes due to expanded version control
763 key words. This is important for typeahead to work as expected.
764 ARG and NO-CONFIRM are passed on to `revert-buffer'."
768 ;; Use save-excursion here, because it may be able to restore point
769 ;; and mark properly even in cases where vc-restore-buffer-context
770 ;; would fail. However, save-excursion might also get it wrong --
771 ;; in this case, vc-restore-buffer-context gives it a second try.
773 ;; t means don't call normal-mode;
774 ;; that's to preserve various minor modes.
780 "Make sure the current buffer and its working file are in sync.
781 NOT-URGENT means it is ok to continue if the user says not to save."
790 "Has FILE changed since last checkout?"
797 unchanged))))
800 "Default check whether FILE is unchanged: diff against master version."
804 "Force a recomputation of the version control state of FILE.
805 The state is computed using the exact, and possibly expensive
806 function `vc-BACKEND-state', not the heuristic."
810 "Do The Right Thing for a given version-controlled FILE.
811 If COMMENT is specified, it will be used as an admin or checkin comment.
812 If VERBOSE is non-nil, query the user rather than using default parameters."
814 state version)
816 ;; Check relation of buffer and file, and make sure
817 ;; user knows what he's doing. First, finding the file
818 ;; will check whether the file on disk is newer.
826 ;; Now, check if we have unsaved changes.
832 ;; Do the right thing
838 ;; up-to-date
843 ;; go to a different version
847 ;; check the file out
850 ;; do nothing
853 ;; Abnormal: edited but read-only
855 ;; Make the file+buffer read-write. If the user really wanted to
856 ;; commit, he'll get a chance to do that next time around, anyway.
862 ;; edited
865 ;; For files with locking, if the file does not contain
866 ;; any changes, just let go of the lock, i.e. revert.
869 ;; If buffer is modified, that means the user just
870 ;; said no to saving it; in that case, don't revert,
871 ;; because the user might intend to save after
872 ;; finishing the log entry.
874 ;; DO NOT revert the file without asking the user!
882 ;; locked by somebody else
890 state))
892 ;; needs-patch
895 "%s is not up-to-date. Get latest version? "
903 ;; needs-merge
906 "%s is not up-to-date. Merge in changes now? "
911 ;; unlocked-changes
918 file))
923 ;; Must clear any headers here because they wouldn't
924 ;; show that the file is locked now.
936 "Call `vc-next-action-on-file' on all the marked files.
937 Ignores FILE and REV, but passes on COMMENT."
947 nil t))
950 ;; Here's the major entry point.
952 ;;;###autoload
954 "Do the next logical checkin or checkout operation on the current file.
956 If you call this from within a VC dired buffer with no files marked,
957 it will operate on the file in the current line.
959 If you call this from within a VC dired buffer, and one or more
960 files are marked, it will accept a log message and then operate on
961 each one. The log message will be used as a comment for any register
962 or checkin operations, but ignored when doing checkouts. Attempted
963 lock steals will raise an error.
965 A prefix argument lets you specify the version number to use.
967 For RCS and SCCS files:
968 If the file is not already registered, this registers it for version
969 control.
970 If the file is registered and not locked by anyone, this checks out
971 a writable and locked file ready for editing.
972 If the file is checked out and locked by the calling user, this
973 first checks to see if the file has changed since checkout. If not,
974 it performs a revert.
975 If the file has been changed, this pops up a buffer for entry
976 of a log message; when the message has been entered, it checks in the
977 resulting changes along with the log message as change commentary. If
978 the variable `vc-keep-workfiles' is non-nil (which is its default), a
979 read-only copy of the changed file is left in place afterwards.
980 If the file is registered and locked by someone else, you are given
981 the option to steal the lock.
983 For CVS files:
984 If the file is not already registered, this registers it for version
986 If the file is added but not committed, it is committed.
987 If your working file is changed, but the repository file is
988 unchanged, this pops up a buffer for entry of a log message; when the
989 message has been entered, it checks in the resulting changes along
990 with the logmessage as change commentary. A writable file is retained.
991 If the repository file is changed, you are asked if you want to
992 merge in the changes into your working copy."
1007 "Enter a change comment for the marked files."
1016 ;;; These functions help the vc-next-action entry point
1018 ;;;###autoload
1020 "Register the current file into a version control system.
1021 With prefix argument SET-VERSION, allow user to specify initial version
1022 level. If COMMENT is present, use that as an initial comment.
1024 The version control system to use is found by cycling through the list
1025 `vc-handled-backends'. The first backend in that list which declares
1026 itself responsible for the file (usually because other files in that
1027 directory are already registered under that backend) will be used to
1028 register the file. If no backend declares itself responsible, the
1029 first backend that could register the file is used."
1037 ;; Watch out for new buffers of size 0: the corresponding file
1038 ;; does not exist yet, even though buffer-modified-p is nil.
1049 ;; TODO: Use backend-specific init version.
1050 vc-default-init-version)
1052 "Enter initial comment."
1065 "Return the name of the backend system that is responsible for FILE.
1066 If no backend in variable `vc-handled-backends' declares itself
1067 responsible, the first backend in that list will be returned (if optional
1068 arg REGISTER is non-nil, return the first backend that could register the
1069 file).
1070 FILE can also be a directory name (ending with a slash)."
1078 vc-handled-backends)
1083 vc-handled-backends)
1087 "Indicate whether BACKEND is reponsible for FILE.
1088 The default is to return nil always."
1089 nil)
1092 "Return non-nil if BACKEND could be used to register FILE.
1093 The default implementation returns t for all files."
1094 t)
1097 "If FILE is in the current buffer, either revert or unvisit it.
1098 The choice between revert (to see expanded keywords) and unvisit depends on
1099 `vc-keep-workfiles'. NOQUERY if non-nil inhibits confirmation for
1100 reverting. NOQUERY should be t *only* if it is known the only
1101 difference between the buffer and the file is due to version control
1102 rather than user editing!"
1107 ;; TODO: Adjusting view mode might no longer be necessary
1108 ;; after RMS change to files.el of 1999-08-08. Investigate
1109 ;; this when we install the new VC.
1122 "If FILE is currently visited, resynch its buffer."
1132 "Accept a comment for an operation on FILE revision REV.
1133 If COMMENT is nil, pop up a VC-log buffer, emit MSG, and set the
1134 action on close to ACTION; otherwise, do action immediately. Remember
1135 the file's buffer in `vc-parent-buffer' (current one if no file).
1136 AFTER-HOOK specifies the local value for vc-log-operation-hook."
1166 "Retrieve a copy of the revision REV of FILE.
1167 If WRITABLE is non-nil, make sure the retrieved file is writable.
1168 REV defaults to the latest revision."
1170 file
1174 ;; Maybe the backend is not installed ;-(
1182 'up-to-date
1189 "Steal the lock on FILE."
1195 file-description owner)))
1198 nil nil nil nil
1209 ;; This is called when the notification has been sent.
1212 file
1219 "Check in FILE.
1220 The optional argument REV may be a string specifying the new version
1221 level (if nil increment the current level). COMMENT is a comment
1222 string; if omitted, a buffer is popped up to accept a comment.
1224 If `vc-keep-workfiles' is nil, FILE is deleted afterwards, provided
1225 that the version control system supports this mode of operation.
1227 Runs the normal hook `vc-checkin-hook'."
1229 file rev comment
1230 "Enter a change comment."
1233 ;; "This log message intentionally left almost blank".
1234 ;; RCS 5.7 gripes about white-space-only comments too.
1238 file
1239 ;; Change buffers to get local value of vc-checkin-switches.
1249 "Enter last VC comment into change log file for current buffer's file.
1250 Optional arg (interactive prefix) non-nil means prompt for user name and site.
1251 Second arg is file name of change log. \
1252 If nil, uses `change-log-default-name'.
1254 May be useful as a `vc-checkin-hook' to update change logs automatically."
1258 ;; Make sure the defvar for add-log-current-defun-function has been executed
1259 ;; before binding it.
1263 ;; Don't let add-change-log-entry insert a defun name.
1265 end)
1266 ;; Call add-log to do half the work.
1268 ;; Insert the VC comment, leaving point before it.
1271 ;; It starts with an open-paren, as in "(foo): Frobbed."
1272 ;; So remove the ": " add-log inserted.
1274 ;; Canonicalize the white space between the file name and comment.
1276 ;; Indent rest of the text the same way add-log indented the first line.
1283 ;; Fill the inserted text, preserving open-parens at bol.
1288 ;; Canonicalize the white space at the end of the entry so it is
1289 ;; separated from the next entry by a single blank line.
1296 "Complete the operation implied by the current log entry."
1298 ;; Check and record the comment, if any.
1300 ;; Comment too long?
1305 ;; Record the comment in the comment ring
1311 ;; Sync parent buffer in case the user modified it while editing the comment.
1312 ;; But not if it is a vc-dired buffer.
1316 ;; save the parameters held in buffer-local variables
1324 ;; OK, do it to it
1327 log-file
1328 log-version
1329 log-entry))
1330 ;; Remove checkin window (after the checkin so that if that fails
1331 ;; we don't zap the *VC-log* buffer and the typing therein).
1335 ;; Kill buffer and delete any other dedicated windows/frames.
1340 ;; Now make sure we see the expanded headers
1347 ;; Code for access to the comment ring
1352 ;; Initialize the index on the first use of this command
1353 ;; so that the first M-p gets index 0, and the first M-n gets
1354 ;; index -1.
1357 len))
1360 "Cycle backwards through comment history."
1371 "Cycle forwards through comment history."
1376 "Searches backwards through comment history for substring match."
1377 ;; Why substring rather than regexp ? -sm
1394 "Searches forwards through comment history for substring match."
1399 ;; Additional entry points for examining version histories
1401 ;;;###autoload
1403 "Display diffs between file versions.
1404 Normally this compares the current file and buffer with the most recent
1405 checked in version of that file. This uses no arguments.
1406 With a prefix argument, it reads the file name to use
1407 and two version designators specifying which versions to compare."
1419 "For FILE, report diffs between two stored versions REL1 and REL2 of it.
1420 If FILE is a directory, generate diffs between versions for all registered
1421 files in or below it."
1425 "File or dir to diff: (default visited file) "
1427 default-directory buffer-file-name t)))
1429 ;; compute default versions based on the file state
1431 ;; if it's a directory, don't supply any version default
1433 nil)
1434 ;; if the file is not up-to-date, use current version as older version
1437 ;; if the file is not locked, use last and previous version as default
1442 ;; construct argument list
1448 nil nil rel1-default)
1453 nil nil rel2-default))))
1461 " and "
1465 ;; FIXME: this should do a single exec in CVS.
1467 default-directory
1486 nil)
1488 ;; Gnus-5.8.5 sets up an autoload for diff-mode, even if it's
1489 ;; not available. Work around that.
1493 t))
1495 ;;;###autoload
1497 "Visit version REV of the current buffer in another window.
1498 If the current buffer is named `F', the version is named `F.~REV~'.
1499 If `F.~REV~' already exists, it is used instead of being re-created."
1504 rev))
1510 ;; Header-insertion code
1512 ;;;###autoload
1514 "Insert headers in a file for use with your version control system.
1515 Headers desired are inserted at point, and are pulled from
1516 the variable `vc-BACKEND-header'."
1534 hdstrings)
1539 vc-static-header-alist))
1540 )
1541 )))))
1544 "Clear all version headers in the current buffer (or FILE).
1545 I.e. reset them to the non-expanded form."
1552 ;; save-excursion may be able to relocate point and mark
1553 ;; properly. If it fails, vc-restore-buffer-context
1554 ;; will give it a second try.
1562 ;;;###autoload
1564 "Merge changes between two versions into the current buffer's file.
1565 This asks for two versions to merge from in the minibuffer. If the
1566 first version is a branch number, then merge all changes from that
1567 branch. If the first version is empty, merge news, i.e. recent changes
1568 from the current branch.
1570 See Info node `Merging'."
1577 first-version second-version status)
1599 ;; We want to merge an entire branch. Set versions
1600 ;; accordingly, so that vc-BACKEND-merge understands us.
1602 ;; first-version must be the starting point of the branch
1624 ;;;###autoload
1626 "Invoke ediff to resolve conflicts in the current buffer.
1627 The conflicts must be marked with rcsmerge conflict markers."
1676 ;; Fire up ediff.
1680 ;; Ediff is now set up, and we are in the control buffer.
1681 ;; Do a few further adjustments and take precautions for exit.
1705 nil))))
1707 ;; The VC directory major mode. Coopt Dired for this.
1708 ;; All VC commands get mapped into logical equivalents.
1717 ;; Emacs-20 has a lousy keymap inheritance that won't work here.
1718 ;; Emacs-21's is still lousy but just better enough that it'd work. -sm
1719 ;; (set-keymap-parent vmap vc-prefix-map)
1723 map))
1726 "The major mode used in VC directory buffers.
1728 It works like Dired, but lists only files under version control, with
1729 the current VC state of each file being indicated in the place of the
1730 file's link count, owner, group and size. Subdirectories are also
1731 listed, and you may insert them into the buffer as desired, like in
1732 Dired.
1734 All Dired commands operate normally, with the exception of `v', which
1735 is redefined as the version control prefix, so that you can type
1736 `vl', `v=' etc. to invoke `vc-print-log', `vc-diff', and the like on
1737 the file named in the current Dired buffer line. `vv' invokes
1738 `vc-next-action' on this file, or on all files currently marked.
1739 There is a special command, `*l', to mark all files currently locked."
1740 ;; define-derived-mode does it for us in Emacs-21, but not in Emacs-20.
1741 ;; We do it here because dired might not be loaded yet
1742 ;; when vc-dired-mode-map is initialized.
1746 ;; The following is slightly modified from dired.el,
1747 ;; because file lines look a bit different in vc-dired-mode.
1751 ;; In some locales, month abbreviations are as short as 2 letters,
1752 ;; and they can be padded on the right with spaces.
1754 ;; Recognize any non-ASCII character.
1755 ;; The purpose is to match a Kanji character.
1757 ;; (k "[^\x00-\x7f\x80-\xff]")
1766 ;; the .* below ensures that we find the last match on a line
1769 vc-dired-switches
1771 vc-dired-switches))
1776 "Toggle terse display in VC Dired."
1779 nil
1786 "Mark all files currently locked."
1806 "Reformat a directory-listing line.
1807 Replace various columns with version control information.
1808 This code, like dired, assumes UNIX -l format."
1818 limit t)
1821 limit t)
1824 limit t))
1831 "Reformat the listing according to version control.
1832 Called by dired after any portion of a vc-dired buffer has been read in."
1838 ;; subdir header line
1840 ;; if the backend supports it, get the state
1841 ;; of all files in this directory at once
1846 ;; erase (but don't remove) the "total" line
1850 ;; file line
1853 ;; subdir
1857 vc-directory-exclusion-list)
1863 ;; Don't show directories in terse mode. Don't use
1864 ;; dired-kill-line to remove it, because in recursive listings,
1865 ;; that would remove the directory contents as well.
1873 ;; ordinary file
1881 ;; any other line
1892 "Remove empty subdirs."
1903 ;; We cannot remove the top level directory.
1904 ;; Just make it look a little nicer.
1912 "Return a list of all vc-dired buffers that currently display DIR."
1914 ;; Check whether dired is loaded.
1921 result))
1924 "Update the entries for FILE in any VC Dired buffers that list it."
1930 ;; bind vc-dired-terse-mode to nil so that
1931 ;; files won't vanish when they are checked in
1934 buffers))))
1936 ;;;###autoload
1938 "Create a buffer in VC Dired Mode for directory DIR.
1940 See Info node `VC Dired Mode'.
1942 With prefix arg READ-SWITCHES, specify a value to override
1943 `dired-listing-switches' when generating the listing."
1950 vc-dired-switches)))
1955 vc-dired-switches
1959 ;; Named-configuration entry points
1962 "Scan the tree below DIR, looking for non-uptodate files.
1963 If any file is not up-to-date, return the name of the first such file.
1964 \(This means, neither snapshot creation nor retrieval is allowed.\)
1965 If one or more of the files are currently visited, return `visited'.
1966 Otherwise, return nil."
1970 dir
1974 status)))
1976 ;;;###autoload
1978 "Descending recursively from DIR, make a snapshot called NAME.
1979 For each registered file, the version level of its latest version
1980 becomes part of the named configuration. If the prefix argument
1981 BRANCHP is given, the snapshot is made as a new branch and the files
1982 are checked out in that new branch."
1986 current-prefix-arg))
2000 dir
2004 ;;;###autoload
2006 "Descending recursively from DIR, retrieve the snapshot called NAME.
2007 If NAME is empty, it refers to the latest versions.
2008 If locking is used for the files in DIR, then there must not be any
2009 locked files at or below DIR (but if NAME is empty, locked files are
2010 allowed and simply skipped)."
2028 dir
2039 dir
2045 ;; Miscellaneous other entry points
2047 ;;;###autoload
2049 "List the change log of the current buffer in a window."
2068 ;; move point to the log entry for the current version
2073 'show-log-entry
2076 ;;;###autoload
2078 "Revert the current buffer's file back to the version it was based on.
2079 This asks for confirmation if the buffer contents are not identical
2080 to that version. Note that for RCS and CVS, this function does not
2081 automatically pick up newer changes found in the master file;
2086 ;; This operation should always ask for confirmation.
2100 ;; Do the reverting
2103 file
2110 ;;;###autoload
2112 "Get rid of most recently checked in version of this file.
2113 A prefix argument NOREVERT means do not revert the buffer afterwards."
2126 (error (substitute-command-keys "File is not up to date; use \\[vc-revert-buffer] to discard changes"))))
2134 file
2138 0
2147 ;; inhibit backup for this buffer
2159 "Rename OLDMASTER to be the master file for NEWFILE based on TEMPLATES."
2164 ;; List of potential master files for `newfile'
2167 templates)))
2172 oldmaster
2174 ;; If possible, keep the master file in the same directory.
2177 dir))
2179 masters)
2180 ;; If not, just use the first possible place.
2186 masters)
2189 ;;;###autoload
2191 "Rename file OLD to NEW, and rename its master file likewise."
2193 ;; There are several ways of renaming files under CVS 1.3, but they all
2194 ;; have serious disadvantages. See the FAQ (available from think.com in
2195 ;; pub/cvs/). I'd rather send the user an error, than do something he might
2196 ;; consider to be wrong. When the famous, long-awaited rename database is
2197 ;; implemented things might change for the better. This is unlikely to occur
2198 ;; until CVS 2.0 is released. --ceder 1994-01-23 21:27:51
2213 ;; Move the actual file (unless the backend did it already)
2216 ;; ?? Renaming a file might change its contents due to keyword expansion.
2217 ;; We should really check out a new copy if the old copy was precisely equal
2218 ;; to some checked in version. However, testing for this is tricky....
2227 ;; Only defined in very recent Emacsen
2230 ;;;###autoload
2232 "Find change log file and add entries from recent version control logs.
2233 Normally, find log entries for all registered files in the default
2234 directory.
2236 With prefix arg of \\[universal-argument], only find log entries for the current buffer's file.
2238 With any numeric prefix arg, find log entries for all currently visited
2239 files that are under version control. This puts all the entries in the
2240 log for the default directory, which may not be appropriate.
2242 From a program, any ARGS are assumed to be filenames for which
2243 log entries should be gathered."
2250 file)
2256 files))
2258 ;; Don't supply any filenames to backend; this means
2259 ;; it should find all relevant files relative to
2260 ;; the default-directory.
2261 nil)))
2266 "Default implementation of update-changelog.
2267 Uses `rcs2log' which only works for RCS and CVS."
2268 ;; FIXME: We (c|sh)ould add support for cvs2cl
2271 ;; Presumably not portable to non-Unixy systems, along with rcs2log:
2276 temporary-file-directory))))
2282 user-mail-address)))
2296 exec-directory)
2298 "-c" changelog
2306 f
2308 files)))
2309 "done"
2318 ;;; Annotate functionality
2320 ;; Declare globally instead of additional parameter to
2321 ;; temp-buffer-show-function (not possible to pass more than one
2322 ;; parameter).
2328 Return NIL if no match made. Associations are made based on
2329 `vc-annotate-buffers'."
2333 "Major mode for buffers displaying output from the `annotate' command.
2335 You can use the mode-specific menu to alter the time-span of the used
2336 colors. See variable `vc-annotate-menu-elements' for customizing the
2337 menu items."
2341 "Use the default color spectrum for VC Annotate mode."
2345 nil
2350 "Add the menu 'Annotate' to the menu bar in VC-Annotate mode."
2355 '("Default" . vc-annotate-display-default))
2356 (let ((menu-elements vc-annotate-menu-elements))
2357 (while menu-elements
2358 (let* ((element (car menu-elements))
2359 (days (round (* element
2360 (vc-annotate-car-last-cons vc-annotate-color-map)
2361 0.7585))))
2362 (setq menu-elements (cdr menu-elements))
2363 (define-key vc-annotate-mode-menu
2364 (vector days)
2365 (cons (format "Span %d days"
2366 days)
2367 `(lambda ()
2368 ,(format "Use colors spanning %d days" days)
2369 (interactive)
2370 (message "Redisplaying annotation...")
2371 (vc-annotate-display
2372 (get-buffer (buffer-name))
2373 (vc-annotate-time-span vc-annotate-color-map ,element)
2374 (vc-annotate-get-backend (current-buffer)))
2375 (message "Redisplaying annotation...done"))))))))
2378 ;;;; (defun vc-BACKEND-annotate-command (file buffer) ...)
2379 ;;;; Execute "annotate" on FILE by using `call-process' and insert
2380 ;;;; the contents in BUFFER.
2382 ;;;###autoload
2383 (defun vc-annotate (ratio)
2386 are displayed in red, old in blue. A prefix argument specifies a
2387 factor for stretching the time scale.
2389 `vc-annotate-menu-elements' customizes the menu elements of the
2390 mode-specific menu. `vc-annotate-color-map' and
2391 `vc-annotate-very-old-color' defines the mapping of time to
2392 colors. `vc-annotate-background' specifies the background color."
2393 (interactive "p")
2394 (vc-ensure-vc-buffer)
2395 (message "Annotating...")
2396 (let ((temp-buffer-name (concat "*Annotate " (buffer-name) "*"))
2397 (temp-buffer-show-function 'vc-annotate-display)
2398 (vc-annotate-ratio ratio)
2399 (vc-annotate-backend (vc-backend (buffer-file-name))))
2400 (if (not (vc-find-backend-function vc-annotate-backend 'annotate-command))
2401 (error "Sorry, annotating is not implemented for %s"
2402 vc-annotate-backend))
2403 (with-output-to-temp-buffer temp-buffer-name
2404 (vc-call-backend vc-annotate-backend 'annotate-command
2405 (file-name-nondirectory (buffer-file-name))
2406 (get-buffer temp-buffer-name)))
2407 ;; Don't use the temp-buffer-name until the buffer is created
2408 ;; (only after `with-output-to-temp-buffer'.)
2409 (setq vc-annotate-buffers
2410 (append vc-annotate-buffers
2411 (list (cons (get-buffer temp-buffer-name) vc-annotate-backend)))))
2412 (message "Annotating... done"))
2415 (defun vc-annotate-car-last-cons (a-list)
2416 "Return car of last cons in association list A-LIST."
2417 (if (not (eq nil (cdr a-list)))
2418 (vc-annotate-car-last-cons (cdr a-list))
2419 (car (car a-list))))
2421 (defun vc-annotate-time-span (a-list span &optional quantize)
2422 "Apply factor SPAN to the time-span of association list A-LIST.
2423 Return the new alist.
2424 Optionally quantize to the factor of QUANTIZE."
2425 ;; Apply span to each car of every cons
2426 (if (not (eq nil a-list))
2427 (append (list (cons (* (car (car a-list)) span)
2428 (cdr (car a-list))))
2429 (vc-annotate-time-span (nthcdr (or quantize ; optional
2430 1) ; Default to cdr
2431 a-list) span quantize))))
2433 (defun vc-annotate-compcar (threshold a-list)
2434 "Test successive cons cells of association list A-LIST against THRESHOLD.
2435 Return the first cons cell which car is not less than THRESHOLD,
2436 nil otherwise"
2437 (let ((i 1)
2438 (tmp-cons (car a-list)))
2439 (while (and tmp-cons (< (car tmp-cons) threshold))
2440 (setq tmp-cons (car (nthcdr i a-list)))
2441 (setq i (+ i 1)))
2442 tmp-cons)) ; Return the appropriate value
2445 ;;;; (defun vc-BACKEND-annotate-difference (point) ...)
2446 ;;;;
2447 ;;;; Return the difference between the age of the line at point and
2448 ;;;; the current time. Return NIL if there is no more comparison to
2449 ;;;; be made in the buffer. Return value as defined for
2450 ;;;; `current-time'. You can safely assume that point is placed at
2451 ;;;; the beginning of each line, starting at `point-min'. The buffer
2452 ;;;; that point is placed in is the Annotate output, as defined by
2453 ;;;; the relevant backend.
2455 (defun vc-annotate-display (buffer &optional color-map backend)
2456 "Do the VC-Annotate display in BUFFER using COLOR-MAP.
2457 The original annotating file is supposed to be handled by BACKEND.
2458 If BACKEND is NIL, variable VC-ANNOTATE-BACKEND is used instead.
2459 This function is destructive on VC-ANNOTATE-BACKEND when BACKEND is non-nil."
2461 ;; Handle the case of the global variable vc-annotate-ratio being
2462 ;; set. This variable is used to pass information from function
2463 ;; vc-annotate since it is not possible to use another parameter
2464 ;; (see temp-buffer-show-function).
2465 (if (and (not color-map) vc-annotate-ratio)
2466 ;; This will only be true if called from vc-annotate with ratio
2467 ;; being non-nil.
2468 (setq color-map (vc-annotate-time-span vc-annotate-color-map
2469 vc-annotate-ratio)))
2470 (set-buffer buffer)
2471 (display-buffer buffer)
2472 (if (not vc-annotate-mode) ; Turn on vc-annotate-mode if not done
2473 (vc-annotate-mode))
2474 (goto-char (point-min)) ; Position at the top of the buffer.
2475 ;; Delete old overlays
2476 (mapcar
2477 (lambda (overlay)
2478 (if (overlay-get overlay 'vc-annotation)
2479 (delete-overlay overlay)))
2480 (overlays-in (point-min) (point-max)))
2481 (goto-char (point-min)) ; Position at the top of the buffer.
2483 (if backend (setq vc-annotate-backend backend)) ; Destructive on `vc-annotate-backend'
2485 (let ((difference (vc-call-backend vc-annotate-backend 'annotate-difference (point))))
2486 (while difference
2487 (let*
2488 ((color (or (vc-annotate-compcar
2489 difference (or color-map vc-annotate-color-map))
2490 (cons nil vc-annotate-very-old-color)))
2491 ;; substring from index 1 to remove any leading `#' in the name
2492 (face-name (concat "vc-annotate-face-" (substring (cdr color) 1)))
2493 ;; Make the face if not done.
2494 (face (or (intern-soft face-name)
2495 (let ((tmp-face (make-face (intern face-name))))
2496 (set-face-foreground tmp-face (cdr color))
2497 (if vc-annotate-background
2498 (set-face-background tmp-face vc-annotate-background))
2499 tmp-face))) ; Return the face
2500 (point (point))
2501 overlay)
2502 (forward-line 1)
2503 (setq overlay (make-overlay point (point)))
2504 (overlay-put overlay 'face face)
2505 (overlay-put overlay 'vc-annotation t))
2506 (setq difference (vc-call-backend vc-annotate-backend 'annotate-difference (point))))))
2508 \f
2509 ;; Collect back-end-dependent stuff here
2511 (defalias 'vc-default-logentry-check 'ignore)
2513 (defun vc-check-headers ()
2514 "Check if the current file has any headers in it."
2515 (interactive)
2516 (vc-call-backend (vc-backend buffer-file-name) 'check-headers))
2518 ;; Back-end-dependent stuff ends here.
2520 ;; Set up key bindings for use while editing log messages
2522 (define-derived-mode vc-log-mode text-mode "VC-Log"
2523 "Major mode for editing VC log entries.
2524 These bindings are added to the global keymap when you enter this mode:
2538 While you are entering a change log message for a version, the following
2539 additional bindings will be in effect.
2543 Whenever you do a checkin, your log comment is added to a ring of
2544 saved comments. These can be recalled as follows:
2551 Entry to the change-log submode calls the value of `text-mode-hook', then
2552 the value of `vc-log-mode-hook'.
2554 Global user options:
2555 `vc-initial-comment' If non-nil, require user to enter a change
2556 comment upon first checkin of the file.
2558 `vc-keep-workfiles' Non-nil value prevents workfiles from being
2559 deleted when changes are checked in
2561 `vc-suppress-confirm' Suppresses some confirmation prompts,
2562 notably for reversions.
2564 vc-BACKEND-header Which keywords to insert when adding headers
2567 RCS and CVS.
2569 `vc-static-header-alist' By default, version headers inserted in C files
2570 get stuffed in a static string area so that
2571 ident(RCS/CVS) or what(SCCS) can see them in
2572 the compiled object code. You can override
2573 this by setting this variable to nil, or change
2574 the header template by changing it.
2576 `vc-command-messages' if non-nil, display run messages from the
2577 actual version-control utilities (this is
2578 intended primarily for people hacking vc
2579 itself)."
2580 (make-local-variable 'vc-comment-ring-index))
2582 (defun vc-log-edit (file)
2583 "Set up `log-edit' for use with VC on FILE.
2584 If `log-edit' is not available, resort to `vc-log-mode'."
2585 (setq default-directory
2586 (if file (file-name-directory file)
2587 (with-current-buffer vc-parent-buffer default-directory)))
2588 (if (fboundp 'log-edit)
2589 (log-edit 'vc-finish-logentry nil
2590 (if file `(lambda () ',(list (file-name-nondirectory file)))
2591 ;; If FILE is nil, we were called from vc-dired.
2592 (lambda ()
2593 (with-current-buffer vc-parent-buffer
2594 (dired-get-marked-files t)))))
2595 (vc-log-mode))
2596 (set (make-local-variable 'vc-log-file) file)
2597 (make-local-variable 'vc-log-version)
2598 (set-buffer-modified-p nil)
2599 (setq buffer-file-name nil))
2601 ;;; These things should probably be generally available
2603 (defun vc-file-tree-walk (dirname func &rest args)
2604 "Walk recursively through DIRNAME.
2605 Invoke FUNC f ARGS on each VC-managed file f underneath it."
2606 (vc-file-tree-walk-internal (expand-file-name dirname) func args)
2607 (message "Traversing directory %s...done" dirname))
2609 (defun vc-file-tree-walk-internal (file func args)
2610 (if (not (file-directory-p file))
2611 (if (vc-backend file) (apply func file args))
2612 (message "Traversing directory %s..." (abbreviate-file-name file))
2613 (let ((dir (file-name-as-directory file)))
2614 (mapcar
2615 (lambda (f) (or
2616 (string-equal f ".")
2617 (string-equal f "..")
2618 (member f vc-directory-exclusion-list)
2619 (let ((dirf (expand-file-name f dir)))
2620 (or
2621 (file-symlink-p dirf);; Avoid possible loops
2622 (vc-file-tree-walk-internal dirf func args)))))
2623 (directory-files dir)))))
2625 (provide 'vc)
2627 ;;; DEVELOPER'S NOTES ON CONCURRENCY PROBLEMS IN THIS CODE
2628 ;;;
2629 ;;; These may be useful to anyone who has to debug or extend the package.
2630 ;;; (Note that this information corresponds to versions 5.x. Some of it
2631 ;;; might have been invalidated by the additions to support branching
2632 ;;; and RCS keyword lookup. AS, 1995/03/24)
2633 ;;;
2634 ;;; A fundamental problem in VC is that there are time windows between
2635 ;;; vc-next-action's computations of the file's version-control state and
2636 ;;; the actions that change it. This is a window open to lossage in a
2637 ;;; multi-user environment; someone else could nip in and change the state
2638 ;;; of the master during it.
2639 ;;;
2640 ;;; The performance problem is that rlog/prs calls are very expensive; we want
2641 ;;; to avoid them as much as possible.
2642 ;;;
2643 ;;; ANALYSIS:
2644 ;;;
2645 ;;; The performance problem, it turns out, simplifies in practice to the
2646 ;;; problem of making vc-state fast. The two other functions that call
2647 ;;; prs/rlog will not be so commonly used that the slowdown is a problem; one
2648 ;;; makes snapshots, the other deletes the calling user's last change in the
2649 ;;; master.
2650 ;;;
2651 ;;; The race condition implies that we have to either (a) lock the master
2652 ;;; during the entire execution of vc-next-action, or (b) detect and
2653 ;;; recover from errors resulting from dispatch on an out-of-date state.
2654 ;;;
2655 ;;; Alternative (a) appears to be infeasible. The problem is that we can't
2656 ;;; guarantee that the lock will ever be removed. Suppose a user starts a
2657 ;;; checkin, the change message buffer pops up, and the user, having wandered
2658 ;;; off to do something else, simply forgets about it?
2659 ;;;
2660 ;;; Alternative (b), on the other hand, works well with a cheap way to speed up
2661 ;;; vc-state. Usually, if a file is registered, we can read its locked/
2662 ;;; unlocked state and its current owner from its permissions.
2663 ;;;
2664 ;;; This shortcut will fail if someone has manually changed the workfile's
2665 ;;; permissions; also if developers are munging the workfile in several
2666 ;;; directories, with symlinks to a master (in this latter case, the
2667 ;;; permissions shortcut will fail to detect a lock asserted from another
2668 ;;; directory).
2669 ;;;
2670 ;;; Note that these cases correspond exactly to the errors which could happen
2671 ;;; because of a competing checkin/checkout race in between two instances of
2672 ;;; vc-next-action.
2673 ;;;
2674 ;;; For VC's purposes, a workfile/master pair may have the following states:
2675 ;;;
2676 ;;; A. Unregistered. There is a workfile, there is no master.
2677 ;;;
2678 ;;; B. Registered and not locked by anyone.
2679 ;;;
2680 ;;; C. Locked by calling user and unchanged.
2681 ;;;
2682 ;;; D. Locked by the calling user and changed.
2683 ;;;
2684 ;;; E. Locked by someone other than the calling user.
2685 ;;;
2686 ;;; This makes for 25 states and 20 error conditions. Here's the matrix:
2687 ;;;
2688 ;;; VC's idea of state
2689 ;;; |
2690 ;;; V Actual state RCS action SCCS action Effect
2691 ;;; A B C D E
2692 ;;; A . 1 2 3 4 ci -u -t- admin -fb -i<file> initial admin
2693 ;;; B 5 . 6 7 8 co -l get -e checkout
2694 ;;; C 9 10 . 11 12 co -u unget; get revert
2695 ;;; D 13 14 15 . 16 ci -u -m<comment> delta -y<comment>; get checkin
2696 ;;; E 17 18 19 20 . rcs -u -M -l unget -n ; get -g steal lock
2697 ;;;
2698 ;;; All commands take the master file name as a last argument (not shown).
2699 ;;;
2700 ;;; In the discussion below, a "self-race" is a pathological situation in
2701 ;;; which VC operations are being attempted simultaneously by two or more
2702 ;;; Emacsen running under the same username.
2703 ;;;
2704 ;;; The vc-next-action code has the following windows:
2705 ;;;
2706 ;;; Window P:
2707 ;;; Between the check for existence of a master file and the call to
2708 ;;; admin/checkin in vc-buffer-admin (apparent state A). This window may
2709 ;;; never close if the initial-comment feature is on.
2710 ;;;
2711 ;;; Window Q:
2712 ;;; Between the call to vc-workfile-unchanged-p in and the immediately
2713 ;;; following revert (apparent state C).
2714 ;;;
2715 ;;; Window R:
2716 ;;; Between the call to vc-workfile-unchanged-p in and the following
2717 ;;; checkin (apparent state D). This window may never close.
2718 ;;;
2719 ;;; Window S:
2720 ;;; Between the unlock and the immediately following checkout during a
2721 ;;; revert operation (apparent state C). Included in window Q.
2722 ;;;
2723 ;;; Window T:
2724 ;;; Between vc-state and the following checkout (apparent state B).
2725 ;;;
2726 ;;; Window U:
2727 ;;; Between vc-state and the following revert (apparent state C).
2728 ;;; Includes windows Q and S.
2729 ;;;
2730 ;;; Window V:
2731 ;;; Between vc-state and the following checkin (apparent state
2732 ;;; D). This window may never be closed if the user fails to complete the
2733 ;;; checkin message. Includes window R.
2734 ;;;
2735 ;;; Window W:
2736 ;;; Between vc-state and the following steal-lock (apparent
2737 ;;; state E). This window may never close if the user fails to complete
2738 ;;; the steal-lock message. Includes window X.
2739 ;;;
2740 ;;; Window X:
2741 ;;; Between the unlock and the immediately following re-lock during a
2742 ;;; steal-lock operation (apparent state E). This window may never close
2743 ;;; if the user fails to complete the steal-lock message.
2744 ;;;
2745 ;;; Errors:
2746 ;;;
2747 ;;; Apparent state A ---
2748 ;;;
2749 ;;; 1. File looked unregistered but is actually registered and not locked.
2750 ;;;
2751 ;;; Potential cause: someone else's admin during window P, with
2752 ;;; caller's admin happening before their checkout.
2753 ;;;
2754 ;;; RCS: Prior to version 5.6.4, ci fails with message
2755 ;;; "no lock set by <user>". From 5.6.4 onwards, VC uses the new
2756 ;;; ci -i option and the message is "<file>,v: already exists".
2757 ;;; SCCS: admin will fail with error (ad19).
2758 ;;;
2759 ;;; We can let these errors be passed up to the user.
2760 ;;;
2761 ;;; 2. File looked unregistered but is actually locked by caller, unchanged.
2762 ;;;
2763 ;;; Potential cause: self-race during window P.
2764 ;;;
2765 ;;; RCS: Prior to version 5.6.4, reverts the file to the last saved
2766 ;;; version and unlocks it. From 5.6.4 onwards, VC uses the new
2767 ;;; ci -i option, failing with message "<file>,v: already exists".
2768 ;;; SCCS: will fail with error (ad19).
2769 ;;;
2770 ;;; Either of these consequences is acceptable.
2771 ;;;
2772 ;;; 3. File looked unregistered but is actually locked by caller, changed.
2773 ;;;
2774 ;;; Potential cause: self-race during window P.
2775 ;;;
2776 ;;; RCS: Prior to version 5.6.4, VC registers the caller's workfile as
2777 ;;; a delta with a null change comment (the -t- switch will be
2778 ;;; ignored). From 5.6.4 onwards, VC uses the new ci -i option,
2779 ;;; failing with message "<file>,v: already exists".
2780 ;;; SCCS: will fail with error (ad19).
2781 ;;;
2782 ;;; 4. File looked unregistered but is locked by someone else.
2783 ;;;
2784 ;;; Potential cause: someone else's admin during window P, with
2785 ;;; caller's admin happening *after* their checkout.
2786 ;;;
2787 ;;; RCS: Prior to version 5.6.4, ci fails with a
2788 ;;; "no lock set by <user>" message. From 5.6.4 onwards,
2789 ;;; VC uses the new ci -i option, failing with message
2790 ;;; "<file>,v: already exists".
2791 ;;; SCCS: will fail with error (ad19).
2792 ;;;
2793 ;;; We can let these errors be passed up to the user.
2794 ;;;
2795 ;;; Apparent state B ---
2796 ;;;
2797 ;;; 5. File looked registered and not locked, but is actually unregistered.
2798 ;;;
2799 ;;; Potential cause: master file got nuked during window P.
2800 ;;;
2801 ;;; RCS: will fail with "RCS/<file>: No such file or directory"
2802 ;;; SCCS: will fail with error ut4.
2803 ;;;
2804 ;;; We can let these errors be passed up to the user.
2805 ;;;
2806 ;;; 6. File looked registered and not locked, but is actually locked by the
2807 ;;; calling user and unchanged.
2808 ;;;
2809 ;;; Potential cause: self-race during window T.
2810 ;;;
2811 ;;; RCS: in the same directory as the previous workfile, co -l will fail
2812 ;;; with "co error: writable foo exists; checkout aborted". In any other
2813 ;;; directory, checkout will succeed.
2814 ;;; SCCS: will fail with ge17.
2815 ;;;
2816 ;;; Either of these consequences is acceptable.
2817 ;;;
2818 ;;; 7. File looked registered and not locked, but is actually locked by the
2819 ;;; calling user and changed.
2820 ;;;
2821 ;;; As case 6.
2822 ;;;
2823 ;;; 8. File looked registered and not locked, but is actually locked by another
2824 ;;; user.
2825 ;;;
2826 ;;; Potential cause: someone else checks it out during window T.
2827 ;;;
2828 ;;; RCS: co error: revision 1.3 already locked by <user>
2829 ;;; SCCS: fails with ge4 (in directory) or ut7 (outside it).
2830 ;;;
2831 ;;; We can let these errors be passed up to the user.
2832 ;;;
2833 ;;; Apparent state C ---
2834 ;;;
2835 ;;; 9. File looks locked by calling user and unchanged, but is unregistered.
2836 ;;;
2837 ;;; As case 5.
2838 ;;;
2839 ;;; 10. File looks locked by calling user and unchanged, but is actually not
2840 ;;; locked.
2841 ;;;
2842 ;;; Potential cause: a self-race in window U, or by the revert's
2843 ;;; landing during window X of some other user's steal-lock or window S
2844 ;;; of another user's revert.
2845 ;;;
2846 ;;; RCS: succeeds, refreshing the file from the identical version in
2847 ;;; the master.
2848 ;;; SCCS: fails with error ut4 (p file nonexistent).
2849 ;;;
2850 ;;; Either of these consequences is acceptable.
2851 ;;;
2852 ;;; 11. File is locked by calling user. It looks unchanged, but is actually
2853 ;;; changed.
2854 ;;;
2855 ;;; Potential cause: the file would have to be touched by a self-race
2856 ;;; during window Q.
2857 ;;;
2858 ;;; The revert will succeed, removing whatever changes came with
2859 ;;; the touch. It is theoretically possible that work could be lost.
2860 ;;;
2861 ;;; 12. File looks like it's locked by the calling user and unchanged, but
2862 ;;; it's actually locked by someone else.
2863 ;;;
2864 ;;; Potential cause: a steal-lock in window V.
2865 ;;;
2866 ;;; RCS: co error: revision <rev> locked by <user>; use co -r or rcs -u
2867 ;;; SCCS: fails with error un2
2868 ;;;
2869 ;;; We can pass these errors up to the user.
2870 ;;;
2871 ;;; Apparent state D ---
2872 ;;;
2873 ;;; 13. File looks like it's locked by the calling user and changed, but it's
2874 ;;; actually unregistered.
2875 ;;;
2876 ;;; Potential cause: master file got nuked during window P.
2877 ;;;
2878 ;;; RCS: Prior to version 5.6.4, checks in the user's version as an
2879 ;;; initial delta. From 5.6.4 onwards, VC uses the new ci -j
2880 ;;; option, failing with message "no such file or directory".
2881 ;;; SCCS: will fail with error ut4.
2882 ;;;
2883 ;;; This case is kind of nasty. Under RCS prior to version 5.6.4,
2884 ;;; VC may fail to detect the loss of previous version information.
2885 ;;;
2886 ;;; 14. File looks like it's locked by the calling user and changed, but it's
2887 ;;; actually unlocked.
2888 ;;;
2889 ;;; Potential cause: self-race in window V, or the checkin happening
2890 ;;; during the window X of someone else's steal-lock or window S of
2891 ;;; someone else's revert.
2892 ;;;
2893 ;;; RCS: ci will fail with "no lock set by <user>".
2894 ;;; SCCS: delta will fail with error ut4.
2895 ;;;
2896 ;;; 15. File looks like it's locked by the calling user and changed, but it's
2897 ;;; actually locked by the calling user and unchanged.
2898 ;;;
2899 ;;; Potential cause: another self-race --- a whole checkin/checkout
2900 ;;; sequence by the calling user would have to land in window R.
2901 ;;;
2902 ;;; SCCS: checks in a redundant delta and leaves the file unlocked as usual.
2903 ;;; RCS: reverts to the file state as of the second user's checkin, leaving
2904 ;;; the file unlocked.
2905 ;;;
2906 ;;; It is theoretically possible that work could be lost under RCS.
2907 ;;;
2908 ;;; 16. File looks like it's locked by the calling user and changed, but it's
2909 ;;; actually locked by a different user.
2910 ;;;
2911 ;;; RCS: ci error: no lock set by <user>
2912 ;;; SCCS: unget will fail with error un2
2913 ;;;
2914 ;;; We can pass these errors up to the user.
2915 ;;;
2916 ;;; Apparent state E ---
2917 ;;;
2918 ;;; 17. File looks like it's locked by some other user, but it's actually
2919 ;;; unregistered.
2920 ;;;
2921 ;;; As case 13.
2922 ;;;
2923 ;;; 18. File looks like it's locked by some other user, but it's actually
2924 ;;; unlocked.
2925 ;;;
2926 ;;; Potential cause: someone released a lock during window W.
2927 ;;;
2928 ;;; RCS: The calling user will get the lock on the file.
2929 ;;; SCCS: unget -n will fail with cm4.
2930 ;;;
2931 ;;; Either of these consequences will be OK.
2932 ;;;
2933 ;;; 19. File looks like it's locked by some other user, but it's actually
2934 ;;; locked by the calling user and unchanged.
2935 ;;;
2936 ;;; Potential cause: the other user relinquishing a lock followed by
2937 ;;; a self-race, both in window W.
2938 ;;;
2939 ;;; Under both RCS and SCCS, both unlock and lock will succeed, making
2940 ;;; the sequence a no-op.
2941 ;;;
2942 ;;; 20. File looks like it's locked by some other user, but it's actually
2943 ;;; locked by the calling user and changed.
2944 ;;;
2945 ;;; As case 19.
2946 ;;;
2947 ;;; PROBLEM CASES:
2948 ;;;
2949 ;;; In order of decreasing severity:
2950 ;;;
2951 ;;; Cases 11 and 15 are the only ones that potentially lose work.
2952 ;;; They would require a self-race for this to happen.
2953 ;;;
2954 ;;; Case 13 in RCS loses information about previous deltas, retaining
2955 ;;; only the information in the current workfile. This can only happen
2956 ;;; if the master file gets nuked in window P.
2957 ;;;
2958 ;;; Case 3 in RCS and case 15 under SCCS insert a redundant delta with
2959 ;;; no change comment in the master. This would require a self-race in
2960 ;;; window P or R respectively.
2961 ;;;
2962 ;;; Cases 2, 10, 19 and 20 do extra work, but make no changes.
2963 ;;;
2964 ;;; Unfortunately, it appears to me that no recovery is possible in these
2965 ;;; cases. They don't yield error messages, so there's no way to tell that
2966 ;;; a race condition has occurred.
2967 ;;;
2968 ;;; All other cases don't change either the workfile or the master, and
2969 ;;; trigger command errors which the user will see.
2970 ;;;
2971 ;;; Thus, there is no explicit recovery code.
2973 ;;; vc.el ends here