autoconf: Automatically derive version number from latest git tag

3 files changed, 26 insertions, 2 deletions

diff --git a/Makefile.am b/Makefile.am
index 4d21b65..84b196d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -11,7 +11,11 @@ SUBDIRS += fuzz
 endif
 
 EXTRA_DIST = \
-        README.md
+        README.md \
+        git-version-gen
+
+dist-hook:
+        echo $(VERSION) > $(distdir)/.tarball-version
 
 docs/html: $(top_builddir)/doxygen.cfg $(top_srcdir)/include/plist/*.h
         rm -rf docs/html
diff --git a/configure.ac b/configure.ac
index 0d13e04..d1b1f62 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ(2.68)
-AC_INIT([libplist], [2.2.1], [https://github.com/libimobiledevice/libplist/issues],, [https://libimobiledevice.org])
+AC_INIT([libplist], [m4_esyscmd(./git-version-gen $RELEASE_VERSION)], [https://github.com/libimobiledevice/libplist/issues],, [https://libimobiledevice.org])
 AM_INIT_AUTOMAKE([dist-bzip2 no-dist-gzip check-news])
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES])
 AC_CONFIG_SRCDIR([src/])
@@ -19,6 +19,11 @@ LIBPLIST_SO_VERSION=6:0:3
 
 AC_SUBST(LIBPLIST_SO_VERSION)
 
+# Check if we have a version defined
+if test -z $PACKAGE_VERSION; then
+  AC_MSG_ERROR([PACKAGE_VERSION is not defined. Make sure to configure a source tree checked out from git or that .tarball-version is present.])
+fi
+
 # Checks for programs.
 AC_PROG_CC
 AC_PROG_CXX
diff --git a/git-version-gen b/git-version-gen
new file mode 100755
index 0000000..6feac34
--- /dev/null
+++ b/git-version-gen
@@ -0,0 +1,15 @@
+#!/bin/sh
+SRCDIR=`dirname $0`
+if test -n "$1"; then
+  VER=$1
+else
+  if test -d "${SRCDIR}/.git" && test -x "`which git`" ; then
+    git update-index -q --refresh
+    VER=`git describe --tags --always --dirty=-dirty`
+  else
+    if test -f "${SRCDIR}/.tarball-version"; then
+      VER=`cat "${SRCDIR}/.tarball-version"`
+    fi
+  fi
+fi
+printf %s "$VER"