git-version-gen: use (...) rather than sh -c '...'

[gnulib.git] / build-aux / git-version-gen

diff --git a/build-aux/git-version-gen b/build-aux/git-version-gen
index be85b6d..694ba46 100755 (executable)
--- a/build-aux/git-version-gen
+++ b/build-aux/git-version-gen
@@ -1,8 +1,8 @@
 #!/bin/sh
 # Print a version string.
-scriptversion=2010-04-26.15; # UTC
+scriptversion=2011-01-03.20; # UTC
 
-# Copyright (C) 2007-2010 Free Software Foundation, Inc.
+# Copyright (C) 2007-2011 Free Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -67,37 +67,47 @@ scriptversion=2010-04-26.15; # UTC
 #      echo $(VERSION) > $(distdir)/.tarball-version
 
 case $# in
-    1) ;;
-    *) echo 1>&2 "Usage: $0 \$srcdir/.tarball-version"; exit 1;;
+    1|2) ;;
+    *) echo 1>&2 "Usage: $0 \$srcdir/.tarball-version" \
+         '[TAG-NORMALIZATION-SED-SCRIPT]'
+       exit 1;;
 esac
 
 tarball_version_file=$1
+tag_sed_script="${2:-s/x/x/}"
 nl='
 '
 
+# Avoid meddling by environment variable of the same name.
+v=
+
 # First see if there is a tarball-only version file.
 # then try "git describe", then default.
 if test -f $tarball_version_file
 then
-    v=`cat $tarball_version_file` || exit 1
+    v=`cat $tarball_version_file` || v=
     case $v in
-       *$nl*) v= ;; # reject multi-line output
-       [0-9]*) ;;
-       *) v= ;;
+        *$nl*) v= ;; # reject multi-line output
+        [0-9]*) ;;
+        *) v= ;;
     esac
     test -z "$v" \
-       && echo "$0: WARNING: $tarball_version_file seems to be damaged" 1>&2
+        && echo "$0: WARNING: $tarball_version_file is missing or damaged" 1>&2
 fi
 
 if test -n "$v"
 then
     : # use $v
-elif test -d .git \
+# Otherwise, if there is at least one git commit involving the working
+# directory, and "git describe" output looks sensible, use that to
+# derive a version string.
+elif test "`git log -1 --pretty=format:x . 2>&1`" = x \
     && v=`git describe --abbrev=4 --match='v*' HEAD 2>/dev/null \
-         || git describe --abbrev=4 HEAD 2>/dev/null` \
+          || git describe --abbrev=4 HEAD 2>/dev/null` \
+    && v=`printf '%s\n' "$v" | sed "$tag_sed_script"` \
     && case $v in
-        v[0-9]*) ;;
-        *) (exit 1) ;;
+         v[0-9]*) ;;
+         *) (exit 1) ;;
        esac
 then
     # Is this a new git that lists number of commits since the last
@@ -105,16 +115,20 @@ then
     #   Newer: v6.10-77-g0f8faeb
     #   Older: v6.10-g0f8faeb
     case $v in
-       *-*-*) : git describe is okay three part flavor ;;
-       *-*)
-           : git describe is older two part flavor
-           # Recreate the number of commits and rewrite such that the
-           # result is the same as if we were using the newer version
-           # of git describe.
-           vtag=`echo "$v" | sed 's/-.*//'`
-           numcommits=`git rev-list "$vtag"..HEAD | wc -l`
-           v=`echo "$v" | sed "s/\(.*\)-\(.*\)/\1-$numcommits-\2/"`;
-           ;;
+        *-*-*) : git describe is okay three part flavor ;;
+        *-*)
+            : git describe is older two part flavor
+            # Recreate the number of commits and rewrite such that the
+            # result is the same as if we were using the newer version
+            # of git describe.
+            vtag=`echo "$v" | sed 's/-.*//'`
+            commit_list=`git rev-list "$vtag"..HEAD 2>/dev/null` \
+                || { commit_list=failed;
+                     echo "$0: WARNING: git rev-list failed" 1>&2; }
+            numcommits=`echo "$commit_list" | wc -l`
+            v=`echo "$v" | sed "s/\(.*\)-\(.*\)/\1-$numcommits-\2/"`;
+            test "$commit_list" = failed && v=UNKNOWN
+            ;;
     esac
 
     # Change the first '-' to a '.', so version-comparing tools work properly.
@@ -129,19 +143,18 @@ v=`echo "$v" |sed 's/^v//'`
 # Don't declare a version "dirty" merely because a time stamp has changed.
 git update-index --refresh > /dev/null 2>&1
 
-dirty=`sh -c 'git diff-index --name-only HEAD' 2>/dev/null` || dirty=
+dirty=`(git diff-index --name-only HEAD) 2>/dev/null` || dirty=
 case "$dirty" in
     '') ;;
     *) # Append the suffix only if there isn't one already.
-       case $v in
-         *-dirty) ;;
-         *) v="$v-dirty" ;;
-       esac ;;
+        case $v in
+          *-dirty) ;;
+          *) v="$v-dirty" ;;
+        esac ;;
 esac
 
 # Omit the trailing newline, so that m4_esyscmd can use the result directly.
-echo "$v" | tr -d '
-'
+echo "$v" | tr -d "$nl"
 
 # Local variables:
 # eval: (add-hook 'write-file-hooks 'time-stamp)