| blob | b81b2990502b88e0600c0e489763208d10407f7a |
1 ;;; vc.el --- drive a version-control system from within Emacs
3 ;; Copyright (C) 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
5 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
6 ;; Modified by:
7 ;; ttn@netcom.com
8 ;; Per Cederqvist <ceder@lysator.liu.edu>
9 ;; Andre Spiegel <spiegel@berlin.informatik.uni-stuttgart.de>
11 ;; This file is part of GNU Emacs.
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.
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.
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
25 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
27 ;;; Commentary:
29 ;; This mode is fully documented in the Emacs user's manual.
30 ;;
31 ;; This was designed and implemented by Eric Raymond <esr@snark.thyrsus.com>.
32 ;; Paul Eggert <eggert@twinsun.com>, Sebastian Kremer <sk@thp.uni-koeln.de>,
33 ;; and Richard Stallman contributed valuable criticism, support, and testing.
34 ;; CVS support was added by Per Cederqvist <ceder@lysator.liu.se>
35 ;; in Jan-Feb 1994.
36 ;;
37 ;; Supported version-control systems presently include SCCS, RCS, and CVS.
38 ;;
39 ;; Some features will not work with old RCS versions. Where
40 ;; appropriate, VC finds out which version you have, and allows or
41 ;; disallows those features (stealing locks, for example, works only
42 ;; from 5.6.2 onwards).
43 ;; Even initial checkins will fail if your RCS version is so old that ci
44 ;; doesn't understand -t-; this has been known to happen to people running
45 ;; NExTSTEP 3.0.
46 ;;
47 ;; You can support the RCS -x option by adding pairs to the
48 ;; vc-master-templates list.
49 ;;
50 ;; Proper function of the SCCS diff commands requires the shellscript vcdiff
51 ;; to be installed somewhere on Emacs's path for executables.
52 ;;
53 ;; If your site uses the ChangeLog convention supported by Emacs, the
54 ;; function vc-comment-to-change-log should prove a useful checkin hook.
55 ;;
56 ;; This code depends on call-process passing back the subprocess exit
57 ;; status. Thus, you need Emacs 18.58 or later to run it. For the
58 ;; vc-directory command to work properly as documented, you need 19.
59 ;; You also need Emacs 19's ring.el.
60 ;;
61 ;; The vc code maintains some internal state in order to reduce expensive
62 ;; version-control operations to a minimum. Some names are only computed
63 ;; once. If you perform version control operations with RCS/SCCS/CVS while
64 ;; vc's back is turned, or move/rename master files while vc is running,
65 ;; vc may get seriously confused. Don't do these things!
66 ;;
67 ;; Developer's notes on some concurrency issues are included at the end of
68 ;; the file.
70 ;;; Code:
79 minor-mode-alist)))
81 ;; To implement support for a new version-control system, add another
82 ;; branch to the vc-backend-dispatch macro and fill it in in each
83 ;; call. The variable vc-master-templates in vc-hooks.el will also
84 ;; have to change.
87 "Execute FORM1, FORM2 or FORM3 for SCCS, RCS or CVS respectively.
88 If FORM3 is `RCS', use FORM2 for CVS as well as RCS.
89 \(CVS shares some code with RCS)."
96 )))
98 ;; General customization
116 ;;; This is duplicated in diff.el.
120 ;;;###autoload
125 "*List of functions called when a buffer is made writable. See `run-hooks.'
126 This hook is only used when the version control system is CVS. It
127 might be useful for sites who uses locking with CVS, or who uses link
130 ;; Header-insertion hair
138 "*Associate static header string templates with file types. A \%s in the
139 template is replaced with the first string associated with the file's
144 "*Special comment delimiters to be used in generating vc headers only.
145 Add an entry in this list if you need to override the normal comment-start
146 and comment-end variables. This will only be necessary if the mode language
149 ;; Default is to be extra careful for super-user.
151 "*Non-nil means be extra-careful in checkout.
152 Verify that the file really is not locked
156 "*The release number of your RCS installation, as a string.
160 "*The release number of your SCCS installation, as a string.
164 "*The release number of your SCCS installation, as a string.
167 ;; Variables the user doesn't need to know about.
172 ;; In a log entry buffer, this is a local variable
173 ;; that points to the buffer for which it was made
174 ;; (either a file, or a VC dired buffer).
190 ;; Back-portability to Emacs 18
200 ; Conditionally rebind some things for Emacs 18 compatibility
206 ))
211 ;;; Find and compare backend releases
214 ;; Returns which backend release is installed on this system.
236 vc-sccs-release)))
239 ;; Compare release numbers, represented as strings.
240 ;; Release components are assumed cardinal numbers, not decimal
241 ;; fractions (5.10 is a higher release than 5.9). Omitted fields
242 ;; are considered lower (5.6.7 is earlier than 5.6.7.1).
243 ;; Comparison runs till the end of the string is found, or a
244 ;; non-numeric component shows up (5.6.7 is earlier than "5.6.7 beta",
245 ;; which is probably not what you want in some cases).
246 ;; This code is suitable for existing RCS release numbers.
247 ;; CVS releases are handled reasonably, too (1.3 < 1.4* < 1.5).
268 ;; Return t if we have RELEASE of BACKEND or better
275 ;;; functions that operate on RCS revision numbers
278 ;; return t if REV is a revision on the trunk
282 ;; return the branch part of a revision number REV
285 ;; File property caching
288 "Clear all cached file properties and the comment ring."
291 ;; Note: there is potential for minor lossage here if there is an open
292 ;; log buffer with a nonzero local value of vc-comment-ring-index.
296 ;; clear all properties of FILE that were retrieved
297 ;; from the master file
312 ;; Return the RCS head version of FILE
317 ;; Random helper functions
320 ;; return t iff the current workfile version of FILE is
321 ;; the latest on its branch.
323 ;; SCCS
325 ;; RCS
329 ;; Re-fetch the head version number. This is to make
330 ;; sure that no-one has checked in a new version behind
331 ;; our back.
334 workfile-version))
335 ;; If we are not on the trunk, we need to examine the
336 ;; whole current branch. (vc-master-workfile-version
337 ;; is not what we need.)
347 ;; CVS
348 t))
358 "Look for a command anywhere on the subprocess-command search path."
371 exec-path)
372 nil)))
375 "Execute a version-control command, notifying user and checking for errors.
376 Output from COMMAND goes to BUFFER, or *vc* if BUFFER is nil.
377 The command is successful if its exit status does not exceed OKSTATUS.
378 The last argument of the command is the master name of FILE if LAST is
379 `MASTER', or the workfile of FILE if LAST is `WORKFILE'; this is appended
380 to an optional list of FLAGS."
389 status)
400 flags)
411 ;; Add vc-path to PATH for the execution of this command.
414 path-separator
416 process-environment)))
429 status))
430 )
433 )
435 status)
436 )
438 ;;; Save a bit of the text around POSN in the current buffer, to help
439 ;;; us find the corresponding position again later. This works even
440 ;;; if all markers are destroyed or corrupted.
441 ;;; A lot of this was shamelessly lifted from Sebastian Kremer's rcs.el mode.
448 ;;; Return the position of CONTEXT in the current buffer, or nil if we
449 ;;; couldn't find it.
459 ;; Can't use search-backward since the match may continue
460 ;; after point.
462 ;; goto-char doesn't signal an error at
463 ;; beginning of buffer like backward-char would
465 ;; to beginning of OSTRING
469 ;; Return a list '(point-context mark-context reparse); from which
470 ;; vc-restore-buffer-context can later restore the context.
472 ;; Use mark-marker to avoid confusion in transient-mark-mode.
475 ;; Make the right thing happen in transient-mark-mode.
477 ;; We may want to reparse the compilation buffer after revert
480 ;; Construct a list; each elt is nil or a buffer
481 ;; iff that buffer is a compilation output buffer
482 ;; that contains markers into the current buffer.
488 compilation-old-error-list
489 compilation-error-list))
504 ;; Restore point/mark, and reparse any affected compilation buffers.
505 ;; CONTEXT is that which vc-buffer-context returns.
509 ;; Reparse affected compilation buffers.
515 ;; Record the position in the compilation buffer of
516 ;; the last error next-error went to.
519 ;; Reparse the error messages as far as they were parsed before.
521 ;; Move the pointer up to find the error we were at before
522 ;; reparsing. Now next-error should properly go to the next one.
528 ;; Restore point and mark
536 ;; Revert buffer, try to keep point and mark where user expects them in spite
537 ;; of changes because of expanded version-control key words.
538 ;; This is quite important since otherwise typeahead won't work as expected.
547 ;; Make sure the current buffer and its working file are in sync
548 ;; NOT-URGENT means it is ok to continue if the user says not to save.
554 nil
559 ;; Has the given workfile changed since last checkout?
566 ;; 0 stands for an unknown time; it can't match any mod time.
568 unchanged)))))
571 ;;; If comment is specified, it will be used as an admin or checkin comment.
574 owner version buffer)
577 ;; if there is no master file corresponding, create one
585 ;; CVS: changes to the master file need to be
586 ;; merged back into the working file
605 "Buffer %s modified; merge file on disc anyhow? "
609 ;; Overlaps detected - what now? Should use some
610 ;; fancy RCS conflict resolving package, or maybe
611 ;; emerge, but for now, simply warn the user with a
612 ;; message.
618 ;; if there is no lock on the file, assert one and get it
626 file))
637 )
653 )))
655 ;; a checked-out version exists, but the user may not own the lock
664 file
667 owner))
669 ;; OK, user owns the lock on the file
675 ;; give luser a chance to save before checking in.
678 ;; Revert if file is unchanged and buffer is too.
679 ;; If buffer is modified, that means the user just said no
680 ;; to saving it; in that case, don't revert,
681 ;; because the user might intend to save
682 ;; after finishing the log entry.
685 ;; DO NOT revert the file without asking the user!
691 ;; user may want to set nonstandard parameters
695 ;; OK, let's do the checkin
697 )))))
700 ;; Do a vc-next-action-on-file on all the marked files, possibly
701 ;; passing on the log comment we've just entered.
708 ;; Adjust the default directory so that checkouts
709 ;; go to the right place.
717 nil t)))
719 ;; Here's the major entry point.
721 ;;;###autoload
723 "Do the next logical checkin or checkout operation on the current file.
724 If you call this from within a VC dired buffer with no files marked,
725 it will operate on the file in the current line.
726 If you call this from within a VC dired buffer, and one or more
727 files are marked, it will accept a log message and then operate on
728 each one. The log message will be used as a comment for any register
729 or checkin operations, but ignored when doing checkouts. Attempted
730 lock steals will raise an error.
731 A prefix argument lets you specify the version number to use.
733 For RCS and SCCS files:
734 If the file is not already registered, this registers it for version
735 control and then retrieves a writable, locked copy for editing.
736 If the file is registered and not locked by anyone, this checks out
737 a writable and locked file ready for editing.
738 If the file is checked out and locked by the calling user, this
739 first checks to see if the file has changed since checkout. If not,
740 it performs a revert.
741 If the file has been changed, this pops up a buffer for entry
742 of a log message; when the message has been entered, it checks in the
743 resulting changes along with the log message as change commentary. If
744 the variable `vc-keep-workfiles' is non-nil (which is its default), a
745 read-only copy of the changed file is left in place afterwards.
746 If the file is registered and locked by someone else, you are given
747 the option to steal the lock.
749 For CVS files:
750 If the file is not already registered, this registers it for version
752 If the file is added but not committed, it is committed.
753 If your working file is changed, but the repository file is
754 unchanged, this pops up a buffer for entry of a log message; when the
755 message has been entered, it checks in the resulting changes along
756 with the logmessage as change commentary. A writable file is retained.
757 If the repository file is changed, you are asked if you want to
758 merge in the changes into your working copy."
775 "Enter a change comment for the marked files."
784 ;;; These functions help the vc-next-action entry point
787 "Retrieve a writable copy of the latest version of the current buffer's file."
789 )
791 ;;;###autoload
793 "Register the current file into your version-control system."
803 ;; Watch out for new buffers of size 0: the corresponding file
804 ;; does not exist yet, even though buffer-modified-p is nil.
811 ;; inhibit backup for this buffer
815 buffer-file-name
819 )
822 ;; If the given file is in the current buffer,
823 ;; either revert on it so we see expanded keyworks,
824 ;; or unvisit it (depending on vc-keep-workfiles)
825 ;; NOQUERY if non-nil inhibits confirmation for reverting.
826 ;; NOQUERY should be t *only* if it is known the only difference
827 ;; between the buffer and the file is due to RCS rather than user editing!
831 ;; temporarily remove vc-find-file-hook, so that
832 ;; we don't lose the properties
840 ;; if FILE is currently visited, resynch its buffer
848 ;; Accept a comment for an operation on FILE revision REV. If COMMENT
849 ;; is nil, pop up a VC-log buffer, emit MSG, and set the
850 ;; action on close to ACTION; otherwise, do action immediately.
851 ;; Remember the file's buffer in vc-parent-buffer (current one if no file).
852 ;; AFTER-HOOK specifies the local value for vc-log-operation-hook.
878 "Check a file into your version-control system.
879 FILE is the unmodified name of the file. REV should be the base version
880 level to check it in under. COMMENT, if specified, is the checkin comment."
884 nil))
887 "Retrieve a copy of the latest version of the given file."
888 ;; If ftp is on this system and the name matches the ange-ftp format
889 ;; for a remote file, the user is trying something that won't work.
896 "Steal the lock on the current workfile."
904 file-description owner)))
920 ;; This is called when the notification has been sent.
929 "Check in the file specified by FILE.
930 The optional argument REV may be a string specifying the new version level
931 \(if nil increment the current level). The file is either retained with write
932 permissions zeroed, or deleted (according to the value of `vc-keep-workfiles').
933 If the back-end is CVS, a writable workfile is always kept.
934 COMMENT is a comment string; if omitted, a buffer is
935 popped up to accept a comment."
940 ;;; Here is a checkin hook that may prove useful to sites using the
941 ;;; ChangeLog facility supported by Emacs.
943 "Enter last VC comment into change log file for current buffer's file.
944 Optional arg (interactive prefix) non-nil means prompt for user name and site.
945 Second arg is file name of change log. \
946 If nil, uses `change-log-default-name'."
950 ;; Make sure the defvar for add-log-current-defun-function has been executed
951 ;; before binding it.
955 ;; Don't let add-change-log-entry insert a defun name.
957 end)
958 ;; Call add-log to do half the work.
960 ;; Insert the VC comment, leaving point before it.
963 ;; It starts with an open-paren, as in "(foo): Frobbed."
964 ;; So remove the ": " add-log inserted.
966 ;; Canonicalize the white space between the file name and comment.
968 ;; Indent rest of the text the same way add-log indented the first line.
975 ;; Fill the inserted text, preserving open-parens at bol.
980 ;; Canonicalize the white space at the end of the entry so it is
981 ;; separated from the next entry by a single blank line.
989 "Complete the operation implied by the current log entry."
991 ;; Check and record the comment, if any.
997 ;; Comment too long?
999 ;; Record the comment in the comment ring
1003 ))
1004 ;; Sync parent buffer in case the user modified it while editing the comment.
1005 ;; But not if it is a vc-dired buffer.
1011 ;; save the parameters held in buffer-local variables
1017 ;; Return to "parent" buffer of this checkin and remove checkin window
1022 ;; OK, do it to it
1025 log-file
1026 log-version
1027 log-entry))
1028 ;; Now make sure we see the expanded headers
1033 ;; Code for access to the comment ring
1036 "Cycle backwards through comment history."
1044 ;; Initialize the index on the first use of this command
1045 ;; so that the first M-p gets index 0, and the first M-n gets
1046 ;; index -1.
1057 "Cycle forwards through comment history."
1062 "Searches backwards through comment history for substring match."
1079 "Searches forwards through comment history for substring match."
1095 ;; Additional entry points for examining version histories
1097 ;;;###autoload
1099 "Display diffs between file versions.
1100 Normally this compares the current file and buffer with the most recent
1101 checked in version of that file. This uses no arguments.
1102 With a prefix argument, it reads the file name to use
1103 and two version designators specifying which versions to compare."
1115 unchanged)
1123 ;; Ideally, we'd like at this point to parse the diff so that
1124 ;; the buffer effectively goes into compilation mode and we
1125 ;; can visit the old and new change locations via next-error.
1126 ;; Unfortunately, this is just too painful to do. The basic
1127 ;; problem is that the `old' file doesn't exist to be
1128 ;; visited. This plays hell with numerous assumptions in
1129 ;; the diff.el and compile.el machinery.
1141 "For FILE, report diffs between two stored versions REL1 and REL2 of it.
1142 If FILE is a directory, generate diffs between versions for all registered
1143 files in or below it."
1156 " and "
1162 default-directory
1170 )))
1175 )
1180 ;;;###autoload
1182 "Visit version REV of the current buffer in another window.
1183 If the current buffer is named `F', the version is named `F.~REV~'.
1184 If `F.~REV~' already exists, it is used instead of being re-created."
1193 rev))
1200 ;; Header-insertion code
1202 ;;;###autoload
1204 "Insert headers in a file for use with your version-control system.
1205 Headers desired are inserted at the start of the buffer, and are pulled from
1206 the variable `vc-header-alist'."
1225 hdstrings)
1230 vc-static-header-alist))
1231 )
1232 )))))
1235 ;; Clear all version headers in the current buffer, i.e. reset them
1236 ;; to the nonexpanded form. Only implemented for RCS, yet.
1237 ;; Don't lose point and mark during this.
1244 ;; The VC directory major mode. Coopt Dired for this.
1245 ;; All VC commands get mapped into logical equivalents.
1248 "The major mode used in VC directory buffers. It is derived from Dired.
1249 All Dired commands operate normally. Users currently locking listed files
1250 are listed in place of the file's owner and group.
1251 Keystrokes bound to VC commands will execute as though they had been called
1252 on a buffer attached to the file named in the current Dired buffer line."
1260 ;; Return the string that indicates the version control status
1261 ;; on a VC dired line.
1274 ;; Hack a directory-listing line, plugging in locking-user info in
1275 ;; place of the user and group info. Should have the beneficial
1276 ;; side-effect of shortening the listing line. Each call starts with
1277 ;; point immediately following the dired mark area on the line to be
1278 ;; hacked.
1279 ;;
1280 ;; Simplest possible one:
1281 ;; (insert (concat x "\t")))
1282 ;;
1283 ;; This code, like dired, assumes UNIX -l format.
1292 limit t)
1295 limit t))
1301 limit t)
1310 ;; Update the vc-dired listing line of file -- it is assumed
1311 ;; that point is already on this line. Don't use dired-do-redisplay
1312 ;; for this, because it cannot handle the way vc-dired deals with
1313 ;; subdirectories.
1332 ;;; Note in Emacs 18 the following defun gets overridden
1333 ;;; with the symbol 'vc-directory-18. See below.
1334 ;;;###autoload
1336 "Show version-control status of the current directory and subdirectories.
1337 Normally it creates a Dired buffer that lists only the locked files
1338 in all these directories. With a prefix argument, it lists all files."
1342 ;; force a trailing slash
1349 dired-buf
1350 dired-buf-mod-count)
1352 dirname
1362 ;; This uses a semi-documented feature of dired; giving a switch
1363 ;; argument forces the buffer to refresh each time.
1370 ;; Make a few modifications to the header
1380 ;; Plug the version information into the individual lines
1391 )
1397 ))
1399 ;; Emacs 18 version
1401 "Show version-control status of all files under the current directory."
1409 default-directory
1426 )
1431 ;; Named-configuration support for SCCS
1436 vc-name-assoc-file
1444 ))
1450 vc-name-assoc-file
1455 ;; (replace-regexp (concat ":" (regexp-quote file) "$") (concat ":" newname))
1460 ))
1463 ;; Return the numeric version corresponding to a named snapshot of file
1464 ;; If name is nil or a version number string it's just passed through
1468 name)
1474 vc-name-assoc-file
1482 ))
1484 ;; Named-configuration entry points
1487 ;; Scan the tree below the current directory.
1488 ;; If any files are locked, return the name of the first such file.
1489 ;; (This means, neither snapshot creation nor retrieval is allowed.)
1490 ;; If one or more of the files are currently visited, return `visited'.
1491 ;; Otherwise, return nil.
1495 default-directory
1500 status)))
1502 ;;;###autoload
1504 "Make a snapshot called NAME.
1505 The snapshot is made from all registered files at or below the current
1506 directory. For each file, the version level of its latest
1507 version becomes part of the named configuration."
1513 default-directory
1517 )))
1519 ;;;###autoload
1521 "Retrieve the snapshot called NAME.
1522 This function fails if any files are locked at or below the current directory
1523 Otherwise, all registered files are checked out (unlocked) at their version
1524 levels in the snapshot."
1533 default-directory
1539 )))
1541 ;; Miscellaneous other entry points
1543 ;;;###autoload
1545 "List the change log of the current buffer in a window."
1563 )
1565 )
1566 )
1568 ;;;###autoload
1570 "Revert the current buffer's file back to the latest checked-in version.
1571 This asks for confirmation if the buffer contents are not identical
1572 to that version.
1573 If the back-end is CVS, this will give you the most recent revision of
1574 the file on the branch you are editing."
1581 ;; This operation should always ask for confirmation.
1599 )
1600 )
1602 ;;;###autoload
1604 "Get rid of most recently checked in version of this file.
1605 A prefix argument means do not revert the buffer afterwards."
1620 nil
1626 ;; If norevert, lock the most recent remaining version,
1627 ;; and mark the buffer modified.
1635 )))
1637 ;;;###autoload
1639 "Rename file OLD to NEW, and rename its master file likewise."
1641 ;; There are several ways of renaming files under CVS 1.3, but they all
1642 ;; have serious disadvantages. See the FAQ (available from think.com in
1643 ;; pub/cvs/). I'd rather send the user an error, than do something he might
1644 ;; consider to be wrong. When the famous, long-awaited rename database is
1645 ;; implemented things might change for the better. This is unlikely to occur
1646 ;; until CVS 2.0 is released. --ceder 1994-01-23 21:27:51
1662 ;; This had FILE, I changed it to OLD. -- rms.
1666 oldmaster
1680 vc-master-templates)
1684 ; ?? Renaming a file might change its contents due to keyword expansion.
1685 ; We should really check out a new copy if the old copy was precisely equal
1686 ; to some checked in version. However, testing for this is tricky....
1692 ;; This had FILE, I changed it to OLD. -- rms.
1695 nil ;RCS
1696 nil ;CVS
1697 )
1698 )
1700 ;;;###autoload
1702 "Find change log file and add entries from recent RCS logs.
1703 The mark is left at the end of the text prepended to the change log.
1704 With prefix arg of C-u, only find log entries for the current buffer's file.
1705 With any numeric prefix arg, find log entries for all files currently visited.
1706 Otherwise, find log entries for all registered files in the default directory.
1707 From a program, any arguments are passed to the `rcs2log' script."
1714 file)
1720 files))
1728 f)))
1741 "-u"
1746 user-mail-address)
1751 f
1753 args))))
1756 ;; Collect back-end-dependent stuff here
1759 ;; Register a file into the version-control system
1760 ;; Automatically retrieves a read-only version of the file with
1761 ;; keywords expanded if vc-keep-workfiles is non-nil, otherwise
1762 ;; it deletes the workfile.
1777 "-fb"
1789 ;; if available, use the secure registering option
1793 file))
1796 "add"
1799 )))
1801 )
1804 ;; Retrieve a copy of a saved version into a workfile
1810 ;; Change buffers to get local value of vc-checkin-switches.
1812 ;; Adjust the default-directory so that the check-out creates
1813 ;; the file in the right place. The old value is restored below.
1817 ;; Some SCCS implementations allow checking out directly to a
1818 ;; file using the -G option, but then some don't so use the
1819 ;; least common denominator approach and use the -p option
1820 ;; ala RCS.
1828 ;; Some shells make the "" dummy argument into $0
1829 ;; while others use the shell's name as $0 and
1830 ;; use the "" as $1. The if-statement
1831 ;; converts the latter case to the former.
1838 filename
1842 vc-checkout-switches)
1848 vc-checkout-switches)
1851 ;; RCS doesn't let us check out into arbitrary file names directly.
1852 ;; Use `co -p' and make stdout point to the correct file.
1860 ;; See the SCCS case, above, regarding the
1861 ;; if-statement.
1868 filename
1871 vc-checkout-switches)
1875 ;; if we should go to the head of the trunk,
1876 ;; clear the default branch first
1879 ;; now do the checkout
1882 ;; If locking is not strict, force to overwrite
1883 ;; the writable workfile.
1887 ;; if no explicit revision was specified,
1888 ;; check out that of the working file
1891 nil)))
1892 vc-checkout-switches)
1893 ;; determine the new workfile version
1901 ;; if necessary, adjust the default branch
1907 new-version))))))
1909 ;; CVS is much like RCS
1917 workfile
1919 "-p"
1920 vc-checkout-switches)
1923 ;; default for verbose checkout: clear the sticky tag
1924 ;; so that the actual update will get the head of the trunk
1927 ;; If a revision was specified, check that out.
1931 "update"
1934 vc-checkout-switches)
1935 ;; If no revision was specified, simply make the file writable.
1958 nil ;; RCS
1960 )
1963 ;; Register changes to FILE as level REV with explanatory COMMENT.
1964 ;; Automatically retrieves a read-only version of the file with
1965 ;; keywords expanded if vc-keep-workfiles is non-nil, otherwise
1966 ;; it deletes the workfile.
1967 ;; Adaption for RCS branch support: if this is an explicit checkin,
1968 ;; or if the checkin creates a new branch, set the master file branch
1969 ;; accordingly.
1971 ;; "This log message intentionally left almost blank".
1972 ;; RCS 5.7 gripes about white-space-only comments too.
1976 ;; Change buffers to get local value of vc-checkin-switches.
1978 ;; Clear the master-properties. Do that here, not at the
1979 ;; end, because if the check-in fails we want them to get
1980 ;; re-computed before the next try.
1983 ;; SCCS
1988 vc-checkin-switches)
1993 )
1994 ;; RCS
1997 ;; if available, use the secure check-in option
2001 vc-checkin-switches)
2005 ;; determine the new workfile version
2016 ;; if we got to a different branch, adjust the default
2017 ;; branch accordingly
2025 ;; If this is an old RCS release, we might have
2026 ;; to remove a remaining lock.
2028 ;; exit status of 1 is also accepted.
2029 ;; It means that the lock was removed before.
2032 ;; CVS
2034 ;; explicit check-in to the trunk requires a
2035 ;; double check-in (first unexplicit) (CVS-1.3)
2041 vc-checkin-switches))
2045 vc-checkin-switches))
2047 ;; The CVS output will be on top of this message.
2050 ;; determine and store the new workfile version
2059 ;; if this was an explicit check-in, remove the sticky tag
2068 ;; Revert file to latest checked-in version.
2069 ;; (for RCS, to workfile version)
2073 file
2074 ;; SCCS
2078 ;; RCS
2081 ;; CVS
2088 )
2091 ;; Steal the lock on the current workfile. Needs RCS 5.6.2 or later for -M.
2097 )
2101 )
2104 )
2107 ;; Undo the latest checkin.
2112 nil ;; this is never reached under CVS
2113 )
2115 )
2118 ;; Get change log associated with FILE.
2120 file
2126 ;; Assign to a FILE's latest version a given NAME.
2131 )
2132 )
2135 ;; Get a difference report between two versions of FILE.
2136 ;; Get only a brief comparison report if CMP, a difference report otherwise.
2144 ;; If we know that --brief is not supported, don't try it.
2146 ;; SCCS and RCS shares a lot of code.
2152 "-q"
2157 diff-switches
2160 command file mode options)))
2161 ;; If --brief didn't work, do a double-take and remember it
2162 ;; for the future.
2168 ;; If --brief DID work, remember that, too.
2171 status)))
2172 ;; CVS is different.
2175 ;; This file is added but not yet committed; there is no master file.
2179 ;; we regard this as "changed".
2180 ;; diff it against /dev/null.
2184 diff-switches
2186 ;; cmp is not yet implemented -- we always do a full diff.
2192 diff-switches
2198 ;; Merge in any new changes made to FILE.
2202 file
2210 ;; CVS doesn't return an error code if conflicts are detected.
2211 ;; Since we want to warn the user about it (and possibly start
2212 ;; emerge later), scan the output and see if this occurred.
2218 )))
2222 "Check if the current file has any headers in it."
2228 (re-search-forward "\\$[A-Za-z\300-\326\330-\366\370-\377]+\\(: [\t -#%-\176\240-\377]*\\)?\\$" nil t) ;; RCS
2230 )
2231 ))
2233 ;; Back-end-dependent stuff ends here.
2235 ;; Set up key bindings for use while editing log messages
2238 "Minor mode for driving version-control tools.
2239 These bindings are added to the global keymap when you enter this mode:
2252 While you are entering a change log message for a version, the following
2253 additional bindings will be in effect.
2257 Whenever you do a checkin, your log comment is added to a ring of
2258 saved comments. These can be recalled as follows:
2265 Entry to the change-log submode calls the value of text-mode-hook, then
2266 the value of vc-log-mode-hook.
2268 Global user options:
2269 vc-initial-comment If non-nil, require user to enter a change
2270 comment upon first checkin of the file.
2272 vc-keep-workfiles Non-nil value prevents workfiles from being
2273 deleted when changes are checked in
2275 vc-suppress-confirm Suppresses some confirmation prompts,
2276 notably for reversions.
2278 vc-header-alist Which keywords to insert when adding headers
2281 RCS and CVS.
2283 vc-static-header-alist By default, version headers inserted in C files
2284 get stuffed in a static string area so that
2285 ident(RCS/CVS) or what(SCCS) can see them in
2286 the compiled object code. You can override
2287 this by setting this variable to nil, or change
2288 the header template by changing it.
2290 vc-command-messages if non-nil, display run messages from the
2291 actual version-control utilities (this is
2292 intended primarily for people hacking vc
2293 itself).
2294 "
2307 )
2309 ;; Initialization code, to be done just once at load-time
2311 nil
2318 )
2320 ;;; These things should probably be generally available
2323 "Walk recursively through DIRNAME.
2324 Invoke FUNC f ARGS on each non-directory file f underneath it."
2347 ;;; DEVELOPER'S NOTES ON CONCURRENCY PROBLEMS IN THIS CODE
2348 ;;;
2349 ;;; These may be useful to anyone who has to debug or extend the package.
2350 ;;; (Note that this information corresponds to versions 5.x. Some of it
2351 ;;; might have been invalidated by the additions to support branching
2352 ;;; and RCS keyword lookup. AS, 1995/03/24)
2353 ;;;
2354 ;;; A fundamental problem in VC is that there are time windows between
2355 ;;; vc-next-action's computations of the file's version-control state and
2356 ;;; the actions that change it. This is a window open to lossage in a
2357 ;;; multi-user environment; someone else could nip in and change the state
2358 ;;; of the master during it.
2359 ;;;
2360 ;;; The performance problem is that rlog/prs calls are very expensive; we want
2361 ;;; to avoid them as much as possible.
2362 ;;;
2363 ;;; ANALYSIS:
2364 ;;;
2365 ;;; The performance problem, it turns out, simplifies in practice to the
2366 ;;; problem of making vc-locking-user fast. The two other functions that call
2367 ;;; prs/rlog will not be so commonly used that the slowdown is a problem; one
2368 ;;; makes snapshots, the other deletes the calling user's last change in the
2369 ;;; master.
2370 ;;;
2371 ;;; The race condition implies that we have to either (a) lock the master
2372 ;;; during the entire execution of vc-next-action, or (b) detect and
2373 ;;; recover from errors resulting from dispatch on an out-of-date state.
2374 ;;;
2375 ;;; Alternative (a) appears to be unfeasible. The problem is that we can't
2376 ;;; guarantee that the lock will ever be removed. Suppose a user starts a
2377 ;;; checkin, the change message buffer pops up, and the user, having wandered
2378 ;;; off to do something else, simply forgets about it?
2379 ;;;
2380 ;;; Alternative (b), on the other hand, works well with a cheap way to speed up
2381 ;;; vc-locking-user. Usually, if a file is registered, we can read its locked/
2382 ;;; unlocked state and its current owner from its permissions.
2383 ;;;
2384 ;;; This shortcut will fail if someone has manually changed the workfile's
2385 ;;; permissions; also if developers are munging the workfile in several
2386 ;;; directories, with symlinks to a master (in this latter case, the
2387 ;;; permissions shortcut will fail to detect a lock asserted from another
2388 ;;; directory).
2389 ;;;
2390 ;;; Note that these cases correspond exactly to the errors which could happen
2391 ;;; because of a competing checkin/checkout race in between two instances of
2392 ;;; vc-next-action.
2393 ;;;
2394 ;;; For VC's purposes, a workfile/master pair may have the following states:
2395 ;;;
2396 ;;; A. Unregistered. There is a workfile, there is no master.
2397 ;;;
2398 ;;; B. Registered and not locked by anyone.
2399 ;;;
2400 ;;; C. Locked by calling user and unchanged.
2401 ;;;
2402 ;;; D. Locked by the calling user and changed.
2403 ;;;
2404 ;;; E. Locked by someone other than the calling user.
2405 ;;;
2406 ;;; This makes for 25 states and 20 error conditions. Here's the matrix:
2407 ;;;
2408 ;;; VC's idea of state
2409 ;;; |
2410 ;;; V Actual state RCS action SCCS action Effect
2411 ;;; A B C D E
2412 ;;; A . 1 2 3 4 ci -u -t- admin -fb -i<file> initial admin
2413 ;;; B 5 . 6 7 8 co -l get -e checkout
2414 ;;; C 9 10 . 11 12 co -u unget; get revert
2415 ;;; D 13 14 15 . 16 ci -u -m<comment> delta -y<comment>; get checkin
2416 ;;; E 17 18 19 20 . rcs -u -M -l unget -n ; get -g steal lock
2417 ;;;
2418 ;;; All commands take the master file name as a last argument (not shown).
2419 ;;;
2420 ;;; In the discussion below, a "self-race" is a pathological situation in
2421 ;;; which VC operations are being attempted simultaneously by two or more
2422 ;;; Emacsen running under the same username.
2423 ;;;
2424 ;;; The vc-next-action code has the following windows:
2425 ;;;
2426 ;;; Window P:
2427 ;;; Between the check for existence of a master file and the call to
2428 ;;; admin/checkin in vc-buffer-admin (apparent state A). This window may
2429 ;;; never close if the initial-comment feature is on.
2430 ;;;
2431 ;;; Window Q:
2432 ;;; Between the call to vc-workfile-unchanged-p in and the immediately
2433 ;;; following revert (apparent state C).
2434 ;;;
2435 ;;; Window R:
2436 ;;; Between the call to vc-workfile-unchanged-p in and the following
2437 ;;; checkin (apparent state D). This window may never close.
2438 ;;;
2439 ;;; Window S:
2440 ;;; Between the unlock and the immediately following checkout during a
2441 ;;; revert operation (apparent state C). Included in window Q.
2442 ;;;
2443 ;;; Window T:
2444 ;;; Between vc-locking-user and the following checkout (apparent state B).
2445 ;;;
2446 ;;; Window U:
2447 ;;; Between vc-locking-user and the following revert (apparent state C).
2448 ;;; Includes windows Q and S.
2449 ;;;
2450 ;;; Window V:
2451 ;;; Between vc-locking-user and the following checkin (apparent state
2452 ;;; D). This window may never be closed if the user fails to complete the
2453 ;;; checkin message. Includes window R.
2454 ;;;
2455 ;;; Window W:
2456 ;;; Between vc-locking-user and the following steal-lock (apparent
2457 ;;; state E). This window may never close if the user fails to complete
2458 ;;; the steal-lock message. Includes window X.
2459 ;;;
2460 ;;; Window X:
2461 ;;; Between the unlock and the immediately following re-lock during a
2462 ;;; steal-lock operation (apparent state E). This window may never cloce
2463 ;;; if the user fails to complete the steal-lock message.
2464 ;;;
2465 ;;; Errors:
2466 ;;;
2467 ;;; Apparent state A ---
2468 ;;;
2469 ;;; 1. File looked unregistered but is actually registered and not locked.
2470 ;;;
2471 ;;; Potential cause: someone else's admin during window P, with
2472 ;;; caller's admin happening before their checkout.
2473 ;;;
2474 ;;; RCS: Prior to version 5.6.4, ci fails with message
2475 ;;; "no lock set by <user>". From 5.6.4 onwards, VC uses the new
2476 ;;; ci -i option and the message is "<file>,v: already exists".
2477 ;;; SCCS: admin will fail with error (ad19).
2478 ;;;
2479 ;;; We can let these errors be passed up to the user.
2480 ;;;
2481 ;;; 2. File looked unregistered but is actually locked by caller, unchanged.
2482 ;;;
2483 ;;; Potential cause: self-race during window P.
2484 ;;;
2485 ;;; RCS: Prior to version 5.6.4, reverts the file to the last saved
2486 ;;; version and unlocks it. From 5.6.4 onwards, VC uses the new
2487 ;;; ci -i option, failing with message "<file>,v: already exists".
2488 ;;; SCCS: will fail with error (ad19).
2489 ;;;
2490 ;;; Either of these consequences is acceptable.
2491 ;;;
2492 ;;; 3. File looked unregistered but is actually locked by caller, changed.
2493 ;;;
2494 ;;; Potential cause: self-race during window P.
2495 ;;;
2496 ;;; RCS: Prior to version 5.6.4, VC registers the caller's workfile as
2497 ;;; a delta with a null change comment (the -t- switch will be
2498 ;;; ignored). From 5.6.4 onwards, VC uses the new ci -i option,
2499 ;;; failing with message "<file>,v: already exists".
2500 ;;; SCCS: will fail with error (ad19).
2501 ;;;
2502 ;;; 4. File looked unregistered but is locked by someone else.
2503 ;;;
2504 ;;; Potential cause: someone else's admin during window P, with
2505 ;;; caller's admin happening *after* their checkout.
2506 ;;;
2507 ;;; RCS: Prior to version 5.6.4, ci fails with a
2508 ;;; "no lock set by <user>" message. From 5.6.4 onwards,
2509 ;;; VC uses the new ci -i option, failing with message
2510 ;;; "<file>,v: already exists".
2511 ;;; SCCS: will fail with error (ad19).
2512 ;;;
2513 ;;; We can let these errors be passed up to the user.
2514 ;;;
2515 ;;; Apparent state B ---
2516 ;;;
2517 ;;; 5. File looked registered and not locked, but is actually unregistered.
2518 ;;;
2519 ;;; Potential cause: master file got nuked during window P.
2520 ;;;
2521 ;;; RCS: will fail with "RCS/<file>: No such file or directory"
2522 ;;; SCCS: will fail with error ut4.
2523 ;;;
2524 ;;; We can let these errors be passed up to the user.
2525 ;;;
2526 ;;; 6. File looked registered and not locked, but is actually locked by the
2527 ;;; calling user and unchanged.
2528 ;;;
2529 ;;; Potential cause: self-race during window T.
2530 ;;;
2531 ;;; RCS: in the same directory as the previous workfile, co -l will fail
2532 ;;; with "co error: writable foo exists; checkout aborted". In any other
2533 ;;; directory, checkout will succeed.
2534 ;;; SCCS: will fail with ge17.
2535 ;;;
2536 ;;; Either of these consequences is acceptable.
2537 ;;;
2538 ;;; 7. File looked registered and not locked, but is actually locked by the
2539 ;;; calling user and changed.
2540 ;;;
2541 ;;; As case 6.
2542 ;;;
2543 ;;; 8. File looked registered and not locked, but is actually locked by another
2544 ;;; user.
2545 ;;;
2546 ;;; Potential cause: someone else checks it out during window T.
2547 ;;;
2548 ;;; RCS: co error: revision 1.3 already locked by <user>
2549 ;;; SCCS: fails with ge4 (in directory) or ut7 (outside it).
2550 ;;;
2551 ;;; We can let these errors be passed up to the user.
2552 ;;;
2553 ;;; Apparent state C ---
2554 ;;;
2555 ;;; 9. File looks locked by calling user and unchanged, but is unregistered.
2556 ;;;
2557 ;;; As case 5.
2558 ;;;
2559 ;;; 10. File looks locked by calling user and unchanged, but is actually not
2560 ;;; locked.
2561 ;;;
2562 ;;; Potential cause: a self-race in window U, or by the revert's
2563 ;;; landing during window X of some other user's steal-lock or window S
2564 ;;; of another user's revert.
2565 ;;;
2566 ;;; RCS: succeeds, refreshing the file from the identical version in
2567 ;;; the master.
2568 ;;; SCCS: fails with error ut4 (p file nonexistent).
2569 ;;;
2570 ;;; Either of these consequences is acceptable.
2571 ;;;
2572 ;;; 11. File is locked by calling user. It looks unchanged, but is actually
2573 ;;; changed.
2574 ;;;
2575 ;;; Potential cause: the file would have to be touched by a self-race
2576 ;;; during window Q.
2577 ;;;
2578 ;;; The revert will succeed, removing whatever changes came with
2579 ;;; the touch. It is theoretically possible that work could be lost.
2580 ;;;
2581 ;;; 12. File looks like it's locked by the calling user and unchanged, but
2582 ;;; it's actually locked by someone else.
2583 ;;;
2584 ;;; Potential cause: a steal-lock in window V.
2585 ;;;
2586 ;;; RCS: co error: revision <rev> locked by <user>; use co -r or rcs -u
2587 ;;; SCCS: fails with error un2
2588 ;;;
2589 ;;; We can pass these errors up to the user.
2590 ;;;
2591 ;;; Apparent state D ---
2592 ;;;
2593 ;;; 13. File looks like it's locked by the calling user and changed, but it's
2594 ;;; actually unregistered.
2595 ;;;
2596 ;;; Potential cause: master file got nuked during window P.
2597 ;;;
2598 ;;; RCS: Prior to version 5.6.4, checks in the user's version as an
2599 ;;; initial delta. From 5.6.4 onwards, VC uses the new ci -j
2600 ;;; option, failing with message "no such file or directory".
2601 ;;; SCCS: will fail with error ut4.
2602 ;;;
2603 ;;; This case is kind of nasty. Under RCS prior to version 5.6.4,
2604 ;;; VC may fail to detect the loss of previous version information.
2605 ;;;
2606 ;;; 14. File looks like it's locked by the calling user and changed, but it's
2607 ;;; actually unlocked.
2608 ;;;
2609 ;;; Potential cause: self-race in window V, or the checkin happening
2610 ;;; during the window X of someone else's steal-lock or window S of
2611 ;;; someone else's revert.
2612 ;;;
2613 ;;; RCS: ci will fail with "no lock set by <user>".
2614 ;;; SCCS: delta will fail with error ut4.
2615 ;;;
2616 ;;; 15. File looks like it's locked by the calling user and changed, but it's
2617 ;;; actually locked by the calling user and unchanged.
2618 ;;;
2619 ;;; Potential cause: another self-race --- a whole checkin/checkout
2620 ;;; sequence by the calling user would have to land in window R.
2621 ;;;
2622 ;;; SCCS: checks in a redundant delta and leaves the file unlocked as usual.
2623 ;;; RCS: reverts to the file state as of the second user's checkin, leaving
2624 ;;; the file unlocked.
2625 ;;;
2626 ;;; It is theoretically possible that work could be lost under RCS.
2627 ;;;
2628 ;;; 16. File looks like it's locked by the calling user and changed, but it's
2629 ;;; actually locked by a different user.
2630 ;;;
2631 ;;; RCS: ci error: no lock set by <user>
2632 ;;; SCCS: unget will fail with error un2
2633 ;;;
2634 ;;; We can pass these errors up to the user.
2635 ;;;
2636 ;;; Apparent state E ---
2637 ;;;
2638 ;;; 17. File looks like it's locked by some other user, but it's actually
2639 ;;; unregistered.
2640 ;;;
2641 ;;; As case 13.
2642 ;;;
2643 ;;; 18. File looks like it's locked by some other user, but it's actually
2644 ;;; unlocked.
2645 ;;;
2646 ;;; Potential cause: someone released a lock during window W.
2647 ;;;
2648 ;;; RCS: The calling user will get the lock on the file.
2649 ;;; SCCS: unget -n will fail with cm4.
2650 ;;;
2651 ;;; Either of these consequences will be OK.
2652 ;;;
2653 ;;; 19. File looks like it's locked by some other user, but it's actually
2654 ;;; locked by the calling user and unchanged.
2655 ;;;
2656 ;;; Potential cause: the other user relinquishing a lock followed by
2657 ;;; a self-race, both in window W.
2658 ;;;
2659 ;;; Under both RCS and SCCS, both unlock and lock will succeed, making
2660 ;;; the sequence a no-op.
2661 ;;;
2662 ;;; 20. File looks like it's locked by some other user, but it's actually
2663 ;;; locked by the calling user and changed.
2664 ;;;
2665 ;;; As case 19.
2666 ;;;
2667 ;;; PROBLEM CASES:
2668 ;;;
2669 ;;; In order of decreasing severity:
2670 ;;;
2671 ;;; Cases 11 and 15 are the only ones that potentially lose work.
2672 ;;; They would require a self-race for this to happen.
2673 ;;;
2674 ;;; Case 13 in RCS loses information about previous deltas, retaining
2675 ;;; only the information in the current workfile. This can only happen
2676 ;;; if the master file gets nuked in window P.
2677 ;;;
2678 ;;; Case 3 in RCS and case 15 under SCCS insert a redundant delta with
2679 ;;; no change comment in the master. This would require a self-race in
2680 ;;; window P or R respectively.
2681 ;;;
2682 ;;; Cases 2, 10, 19 and 20 do extra work, but make no changes.
2683 ;;;
2684 ;;; Unfortunately, it appears to me that no recovery is possible in these
2685 ;;; cases. They don't yield error messages, so there's no way to tell that
2686 ;;; a race condition has occurred.
2687 ;;;
2688 ;;; All other cases don't change either the workfile or the master, and
2689 ;;; trigger command errors which the user will see.
2690 ;;;
2691 ;;; Thus, there is no explicit recovery code.
2693 ;;; vc.el ends here