Improve robustness for out-of-band copy in Tramp
[emacs.git] / lisp / version.el
blobdc228870d1ec8775dffb1530e93bdd0cd1f1a754
1 ;;; version.el --- record version number of Emacs
3 ;; Copyright (C) 1985, 1992, 1994-1995, 1999-2016 Free Software
4 ;; Foundation, Inc.
6 ;; Maintainer: emacs-devel@gnu.org
7 ;; Keywords: internal
8 ;; Package: emacs
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
25 ;;; Commentary:
27 ;;; Code:
29 (defconst emacs-major-version
30 (progn (string-match "^[0-9]+" emacs-version)
31 (string-to-number (match-string 0 emacs-version)))
32 "Major version number of this version of Emacs.
33 This variable first existed in version 19.23.")
35 (defconst emacs-minor-version
36 (progn (string-match "^[0-9]+\\.\\([0-9]+\\)" emacs-version)
37 (string-to-number (match-string 1 emacs-version)))
38 "Minor version number of this version of Emacs.
39 This variable first existed in version 19.23.")
41 (defconst emacs-build-system (system-name)
42 "Name of the system on which Emacs was built, or nil if not available.")
44 (defconst emacs-build-time (if emacs-build-system (current-time))
45 "Time at which Emacs was dumped out, or nil if not available.")
47 (defvar motif-version-string)
48 (defvar gtk-version-string)
49 (defvar ns-version-string)
50 (defvar cairo-version-string)
52 (defun emacs-version (&optional here)
53 "Return string describing the version of Emacs that is running.
54 If optional argument HERE is non-nil, insert string at point.
55 Don't use this function in programs to choose actions according
56 to the system configuration; look at `system-configuration' instead."
57 (interactive "P")
58 (let ((version-string
59 (format "GNU Emacs %s (%s%s%s%s)%s"
60 emacs-version
61 system-configuration
62 (cond ((featurep 'motif)
63 (concat ", " (substring motif-version-string 4)))
64 ((featurep 'gtk)
65 (concat ", GTK+ Version " gtk-version-string))
66 ((featurep 'x-toolkit) ", X toolkit")
67 ((featurep 'ns)
68 (format ", NS %s" ns-version-string))
69 (t ""))
70 (if (featurep 'cairo)
71 (format ", cairo version %s" cairo-version-string)
72 "")
73 (if (and (boundp 'x-toolkit-scroll-bars)
74 (memq x-toolkit-scroll-bars '(xaw xaw3d)))
75 (format ", %s scroll bars"
76 (capitalize (symbol-name x-toolkit-scroll-bars)))
77 "")
78 (if emacs-build-time
79 (format-time-string (concat
80 (if (called-interactively-p
81 'interactive)
82 "" "\n")
83 " of %Y-%m-%d")
84 emacs-build-time)
85 ""))))
86 (if here
87 (insert version-string)
88 (if (called-interactively-p 'interactive)
89 (message "%s" version-string)
90 version-string))))
92 ;; We hope that this alias is easier for people to find.
93 (defalias 'version 'emacs-version)
95 ;; Set during dumping, this is a defvar so that it can be setq'd.
96 (defvar emacs-repository-version nil
97 "String giving the repository revision from which this Emacs was built.
98 Value is nil if Emacs was not built from a repository checkout,
99 or if we could not determine the revision.")
101 (define-obsolete-variable-alias 'emacs-bzr-version
102 'emacs-repository-version "24.4")
104 (define-obsolete-function-alias 'emacs-bzr-get-version
105 'emacs-repository-get-version "24.4")
107 (defun emacs-repository-version-git (dir)
108 "Ask git itself for the version information for directory DIR."
109 (message "Waiting for git...")
110 (with-temp-buffer
111 (let ((default-directory (file-name-as-directory dir)))
112 (and (eq 0
113 (with-demoted-errors "Error running git rev-parse: %S"
114 (call-process "git" nil '(t nil) nil "rev-parse" "HEAD")))
115 (progn (goto-char (point-min))
116 (looking-at "[0-9a-fA-F]\\{40\\}"))
117 (match-string 0)))))
119 (defun emacs-repository--version-git-1 (file dir)
120 "Internal subroutine of `emacs-repository-get-version'."
121 (when (file-readable-p file)
122 (with-temp-buffer
123 (insert-file-contents file)
124 (cond ((looking-at "[0-9a-fA-F]\\{40\\}")
125 (match-string 0))
126 ((looking-at "ref: \\(.*\\)")
127 (emacs-repository--version-git-1
128 (expand-file-name (match-string 1) dir)
129 dir))))))
131 (defun emacs-repository-get-version (&optional dir external)
132 "Try to return as a string the repository revision of the Emacs sources.
133 The format of the returned string is dependent on the VCS in use.
134 Value is nil if the sources do not seem to be under version
135 control, or if we could not determine the revision. Note that
136 this reports on the current state of the sources, which may not
137 correspond to the running Emacs.
139 Optional argument DIR is a directory to use instead of `source-directory'.
140 Optional argument EXTERNAL non-nil means to just ask the VCS itself,
141 if the sources appear to be under version control. Otherwise only ask
142 the VCS if we cannot find any information ourselves."
143 (or dir (setq dir source-directory))
144 (let* ((base-dir (expand-file-name ".git" dir))
145 (in-main-worktree (file-directory-p base-dir))
146 (in-linked-worktree nil)
147 sub-dir)
148 ;; If the sources are in a linked worktree, .git is a file that points to
149 ;; the location of the main worktree and the repo's administrative files.
150 (when (and (not in-main-worktree)
151 (file-regular-p base-dir)
152 (file-readable-p base-dir))
153 (with-temp-buffer
154 (insert-file-contents base-dir)
155 (when (looking-at "gitdir: \\(.*\.git\\)\\(.*\\)$")
156 (setq base-dir (match-string 1)
157 sub-dir (concat base-dir (match-string 2))
158 in-linked-worktree t))))
159 ;; We've found a worktree, either main or linked.
160 (when (or in-main-worktree in-linked-worktree)
161 (if external
162 (emacs-repository-version-git dir)
163 (or (if in-linked-worktree
164 (emacs-repository--version-git-1
165 (expand-file-name "HEAD" sub-dir) base-dir)
166 (let ((files '("HEAD" "refs/heads/master"))
167 file rev)
168 (while (and (not rev)
169 (setq file (car files)))
170 (setq file (expand-file-name file base-dir)
171 files (cdr files)
172 rev (emacs-repository--version-git-1 file base-dir)))
173 rev))
174 ;; AFAICS this doesn't work during dumping (bug#20799).
175 (emacs-repository-version-git dir))))))
177 ;; We put version info into the executable in the form that `ident' uses.
178 (purecopy (concat "\n$Id: " (subst-char-in-string ?\n ?\s (emacs-version))
179 " $\n"))
181 ;;; version.el ends here