Add version generation script, version stamp file

Use a single script to generate the version number from git. This script

  * strips the v from the start of the "git describe" output
  * changes all "-" occurences to "."
  * does NOT create a properly sortable version number from "2.1-rc2"
    type "git describe" output
  * does NOT generate a "proper" "1.2.3" type version number under any
    circumstances
  * will generate "2.1" in case the "git describe" output is "2.1"

These policy might need closer adaption to awesome's tagging habit
some time.

In dist tarballs, ship a "version-stamp" file with the package version
in it. If the "version-stamp" file is present (i.e. if it is a source
tree from a dist tarball), no git checks will be performed.

Concept from autoconf, but code written from scratch to match
awesome's requirements.

Signed-off-by: Julien Danjou <julien@danjou.info>

Makefile.am

@@ -146,9 +146,12 @@ endif
 dist-hook: git-version-check
 distcheck-hook: git-version-check
 
+# Note: We cannot run autogen.sh from here, because we would need some way to
+#       restart the whole dist process from the start and there is none.
+EXTRA_DIST += build-utils/package-version
 git-version-check:
-	git_ver=`{ test -d $(top_srcdir)/.git && git --git-dir=$(top_srcdir)/.git describe 2> /dev/null; } || echo devel`; \
-	if test "x$${git_ver}" = "x$(PACKAGE_VERSION)" -o "x$${git_ver}" = "xv${PACKAGE_VERSION}"; then :; else \
+	git_ver=`$(top_srcdir)/build-utils/package-version $(top_srcdir) version-stamp`; \
+	if test "x$${git_ver}" = "x$(PACKAGE_VERSION)"; then :; else \
 		echo "ERROR: The PACKAGE_VERSION and the 'git describe' version do not match:"; \
 		echo "         current git version:     $${git_ver}"; \
 		echo "         current package version: $(PACKAGE_VERSION)"; \
@@ -156,6 +159,12 @@ git-version-check:
 		exit 1; \
 	fi
 
+# Version stamp files can only exist in tarball source trees.
+#
+# So there is no need to generate them anywhere else or to clean them
+# up anywhere.
+dist-hook:
+	echo "$(PACKAGE_VERSION)" > "$(distdir)/version-stamp"
 
 EXTRA_DIST += awesome.doxygen.in
 

autogen.sh

@@ -7,13 +7,19 @@ srcdir=`dirname "$0"`
 # sed program
 SED=${SED-sed}
 
-# Check whether the version needs to be updated from git infos
+# Check whether the version needs to be updated from VCS/version-stamp
 if [ -d ".git" ] && [ -d "autom4te.cache" ]; then
-  git_describe=`git describe 2>/dev/null || echo devel`
+  git_describe=`./build-utils/package-version . version-stamp`
   for f in autom4te.cache/output.*; do
     [ -f "$f" ] || continue
     pkg_ver=`${SED} -n "s/^PACKAGE_VERSION='\(.*\)'\$/\1/p" "$f"`
-    [ "x$pkg_ver" = "x$git_describe" ] || rm -rf "autom4te.cache"
+    if [ "x$pkg_ver" = "x$git_describe" ]
+    then :
+    else
+      echo "Cleaning out autom4te.cache (${pkg_ver} -> ${git_describe})"
+      rm -rf "autom4te.cache"
+      break
+    fi
   done
 fi
 

build-utils/package-version

@@ -0,0 +1,22 @@
+#!/bin/sh
+# Syntax:
+#   $0 <path-to-top_srcdir> <version-stamp-file>
+#
+# <path-to-top_srcdir> may be relative
+# <version-stamp-file> is relative to src/build topdir
+
+top_srcdir="${1-.}"
+test -d "$top_srcdir" || { \
+	echo "Could not change to top_srcdir '$1'" >&2; \
+	exit 1; \
+}
+version_stamp="${2-version-stamp}"
+
+if test -f "$top_srcdir/$version_stamp"; then # dist source tree
+	cat "$top_srcdir/$version_stamp" | ${TR-tr} -d '\012'
+elif test -d "$top_srcdir/.git"; then # git source tree
+	git_describe=`${GIT-git} --git-dir="$top_srcdir/.git" describe 2>/dev/null || echo devel`
+	echo "$git_describe" | ${SED-sed} -e 's/^v//' -e 's/-/./g' | ${TR-tr} -d '\012'
+else # ???
+	echo "devel" | ${TR-tr} -d '\012'
+fi

configure.ac

@@ -5,7 +5,7 @@ AC_PREREQ(2.61)
 dnl Each time you want an updated version number for your build, you need to
 dnl (re-)run autoreconf.
 AC_INIT([awesome window manager],
-        [m4_esyscmd([{ git describe 2>/dev/null || echo devel; } | tr -d '\n'])],
+        [m4_esyscmd([./build-utils/package-version . version-stamp])],
         [http://awesome.naquadah.org/bugs/],
         [awesome])
 AC_CONFIG_AUX_DIR([auto-aux])
@@ -19,6 +19,12 @@ AM_INIT_AUTOMAKE([-Wall -Werror 1.10 dist-bzip2 foreign filename-length-max=99 f
 
 AC_DEFINE_UNQUOTED([RELEASE], ["Productivity Breaker"])
 
+AC_MSG_CHECKING([package version according to autoconf])
+AC_MSG_RESULT([${PACKAGE_VERSION}])
+AC_MSG_CHECKING([package version according to version script])
+version_script=`"${srcdir}/build-utils/package-version" "${srcdir}" version-stamp`
+AC_MSG_RESULT([${version_script}])
+
 # Checks for programs.
 AC_PROG_SED
 AC_PROG_CC