uuid: Fix typo in comment.
[guix.git] / build-aux / git-version-gen
blob079849d5e523cd8354cbfada84dc7e784f3debfc
1 #!/bin/sh
2 # Print a version string.
3 scriptversion=2017-01-09.19; # UTC
5 # Copyright (C) 2007-2017 Free Software Foundation, Inc.
7 # This program is free software: you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 3 of the License, or
10 # (at your option) any later version.
12 # This program is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with this program. If not, see <http://www.gnu.org/licenses/>.
20 # This script is derived from GIT-VERSION-GEN from GIT: http://git.or.cz/.
21 # It may be run two ways:
22 # - from a git repository in which the "git describe" command below
23 # produces useful output (thus requiring at least one signed tag)
24 # - from a non-git-repo directory containing a .tarball-version file, which
25 # presumes this script is invoked like "./git-version-gen .tarball-version".
27 # In order to use intra-version strings in your project, you will need two
28 # separate generated version string files:
30 # .tarball-version - present only in a distribution tarball, and not in
31 # a checked-out repository. Created with contents that were learned at
32 # the last time autoconf was run, and used by git-version-gen. Must not
33 # be present in either $(srcdir) or $(builddir) for git-version-gen to
34 # give accurate answers during normal development with a checked out tree,
35 # but must be present in a tarball when there is no version control system.
36 # Therefore, it cannot be used in any dependencies. GNUmakefile has
37 # hooks to force a reconfigure at distribution time to get the value
38 # correct, without penalizing normal development with extra reconfigures.
40 # .version - present in a checked-out repository and in a distribution
41 # tarball. Usable in dependencies, particularly for files that don't
42 # want to depend on config.h but do want to track version changes.
43 # Delete this file prior to any autoconf run where you want to rebuild
44 # files to pick up a version string change; and leave it stale to
45 # minimize rebuild time after unrelated changes to configure sources.
47 # As with any generated file in a VC'd directory, you should add
48 # /.version to .gitignore, so that you don't accidentally commit it.
49 # .tarball-version is never generated in a VC'd directory, so needn't
50 # be listed there.
52 # Use the following line in your configure.ac, so that $(VERSION) will
53 # automatically be up-to-date each time configure is run (and note that
54 # since configure.ac no longer includes a version string, Makefile rules
55 # should not depend on configure.ac for version updates).
57 # AC_INIT([GNU project],
58 # m4_esyscmd([build-aux/git-version-gen .tarball-version]),
59 # [bug-project@example])
61 # Then use the following lines in your Makefile.am, so that .version
62 # will be present for dependencies, and so that .version and
63 # .tarball-version will exist in distribution tarballs.
65 # EXTRA_DIST = $(top_srcdir)/.version
66 # BUILT_SOURCES = $(top_srcdir)/.version
67 # $(top_srcdir)/.version:
68 # echo $(VERSION) > $@-t && mv $@-t $@
69 # dist-hook:
70 # echo $(VERSION) > $(distdir)/.tarball-version
73 me=$0
75 version="git-version-gen $scriptversion
77 Copyright 2011 Free Software Foundation, Inc.
78 There is NO warranty. You may redistribute this software
79 under the terms of the GNU General Public License.
80 For more information about these matters, see the files named COPYING."
82 usage="\
83 Usage: $me [OPTION]... \$srcdir/.tarball-version [TAG-NORMALIZATION-SED-SCRIPT]
84 Print a version string.
86 Options:
88 --prefix PREFIX prefix of git tags (default 'v')
89 --fallback VERSION
90 fallback version to use if \"git --version\" fails
92 --help display this help and exit
93 --version output version information and exit
95 Running without arguments will suffice in most cases."
97 prefix=v
98 fallback=
100 while test $# -gt 0; do
101 case $1 in
102 --help) echo "$usage"; exit 0;;
103 --version) echo "$version"; exit 0;;
104 --prefix) shift; prefix=${1?};;
105 --fallback) shift; fallback=${1?};;
107 echo "$0: Unknown option '$1'." >&2
108 echo "$0: Try '--help' for more information." >&2
109 exit 1;;
111 if test "x$tarball_version_file" = x; then
112 tarball_version_file="$1"
113 elif test "x$tag_sed_script" = x; then
114 tag_sed_script="$1"
115 else
116 echo "$0: extra non-option argument '$1'." >&2
117 exit 1
118 fi;;
119 esac
120 shift
121 done
123 if test "x$tarball_version_file" = x; then
124 echo "$usage"
125 exit 1
128 tag_sed_script="${tag_sed_script:-s/x/x/}"
130 nl='
133 # Avoid meddling by environment variable of the same name.
135 v_from_git=
137 # First see if there is a tarball-only version file.
138 # then try "git describe", then default.
139 if test -f $tarball_version_file
140 then
141 v=`cat $tarball_version_file` || v=
142 case $v in
143 *$nl*) v= ;; # reject multi-line output
144 [0-9]*) ;;
145 *) v= ;;
146 esac
147 test "x$v" = x \
148 && echo "$0: WARNING: $tarball_version_file is missing or damaged" 1>&2
151 if test "x$v" != x
152 then
153 : # use $v
154 # Otherwise, if there is at least one git commit involving the working
155 # directory, and "git describe" output looks sensible, use that to
156 # derive a version string.
157 elif test "`git log -1 --pretty=format:x . 2>&1`" = x \
158 && v=`git describe --abbrev=4 --match="$prefix*" HEAD 2>/dev/null \
159 || git describe --abbrev=4 HEAD 2>/dev/null` \
160 && v=`printf '%s\n' "$v" | sed "$tag_sed_script"` \
161 && case $v in
162 $prefix[0-9]*) ;;
163 *) (exit 1) ;;
164 esac
165 then
166 # Is this a new git that lists number of commits since the last
167 # tag or the previous older version that did not?
168 # Newer: v6.10-77-g0f8faeb
169 # Older: v6.10-g0f8faeb
170 case $v in
171 *-*-*) : git describe is okay three part flavor ;;
172 *-*)
173 : git describe is older two part flavor
174 # Recreate the number of commits and rewrite such that the
175 # result is the same as if we were using the newer version
176 # of git describe.
177 vtag=`echo "$v" | sed 's/-.*//'`
178 commit_list=`git rev-list "$vtag"..HEAD 2>/dev/null` \
179 || { commit_list=failed;
180 echo "$0: WARNING: git rev-list failed" 1>&2; }
181 numcommits=`echo "$commit_list" | wc -l`
182 v=`echo "$v" | sed "s/\(.*\)-\(.*\)/\1-$numcommits-\2/"`;
183 test "$commit_list" = failed && v=UNKNOWN
185 esac
187 # Change the first '-' to a '.', so version-comparing tools work properly.
188 # Remove the "g" in git describe's output string, to save a byte.
189 v=`echo "$v" | sed 's/-/./;s/\(.*\)-g/\1-/'`;
190 v_from_git=1
191 elif test "x$fallback" = x || git --version >/dev/null 2>&1; then
192 v=UNKNOWN
193 else
194 v=$fallback
197 v=`echo "$v" |sed "s/^$prefix//"`
199 # Test whether to append the "-dirty" suffix only if the version
200 # string we're using came from git. I.e., skip the test if it's "UNKNOWN"
201 # or if it came from .tarball-version.
202 if test "x$v_from_git" != x; then
203 # Don't declare a version "dirty" merely because a timestamp has changed.
204 git update-index --refresh > /dev/null 2>&1
206 dirty=`exec 2>/dev/null;git diff-index --name-only HEAD` || dirty=
207 case "$dirty" in
208 '') ;;
209 *) # Append the suffix only if there isn't one already.
210 case $v in
211 *-dirty) ;;
212 *) v="$v-dirty" ;;
213 esac ;;
214 esac
217 # Omit the trailing newline, so that m4_esyscmd can use the result directly.
218 printf %s "$v"
220 # Local variables:
221 # eval: (add-hook 'write-file-hooks 'time-stamp)
222 # time-stamp-start: "scriptversion="
223 # time-stamp-format: "%:y-%02m-%02d.%02H"
224 # time-stamp-time-zone: "UTC0"
225 # time-stamp-end: "; # UTC"
226 # End: