build: Untangle the package version from the soversion

Add a new script to generate the package version from git. Use that for
the pkg-config file and the tarball name.

Makefile

@@ -1,3 +1,5 @@
+VERSION := $(shell ./get-version)
+
 LIB_NAME := libbsd
 LIB_VERSION_MAJOR := 0
 LIB_VERSION_MINOR := 1
@@ -10,7 +12,7 @@ LIB_SHARED_SO := $(LIB_NAME).so
 LIB_SONAME := $(LIB_SHARED_SO).$(LIB_VERSION_MAJOR)
 LIB_SHARED := $(LIB_SONAME).$(LIB_VERSION_MINOR).$(LIB_VERSION_MICRO)
 
-TAR_NAME := $(LIB_NAME)-$(LIB_VERSION)
+TAR_NAME := $(LIB_NAME)-$(VERSION)
 TAR_FILE := $(TAR_NAME).tar.gz
 
 LIB_DIST := \
@@ -120,7 +122,7 @@ src/hash/md5hl.c: src/hash/helper.c
 	sed -e 's:hashinc:bsd/md5.h:g' -e 's:HASH:MD5:g' $< > $@
 
 $(LIB_PKGCONFIG): $(LIB_PKGCONFIG).in
-	sed -e 's:@VERSION@:$(LIB_VERSION):' \
+	sed -e 's:@VERSION@:$(VERSION):' \
 	    -e 's:@prefix@:$(value prefix):' \
 	    -e 's:@exec_prefix@:$(value exec_prefix):' \
 	    -e 's:@libdir@:$(value usrlibdir):' \
@@ -149,6 +151,7 @@ ChangeLog:
 .PHONY: dist
 dist: $(LIB_DIST)
 	mkdir $(TAR_NAME)
+	echo $(VERSION) >$(TAR_NAME)/.dist-version
 	cp -a --parents $(LIB_DIST) `git ls-files` $(TAR_NAME)
 	tar czf $(TAR_FILE) --exclude=.gitignore $(TAR_NAME)
 	rm -rf $(TAR_NAME)

get-version

@@ -0,0 +1,48 @@
+#!/bin/sh
+#
+# get-version
+#
+# Copyright © 2009 Guillem Jover <guillem@hadrons.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. The name of the author may not be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+# THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+if [ -f .dist-version ]; then
+  # Get the version from the file distributed in the tarball.
+  version=$(cat .dist-version)
+elif [ -d .git ]; then
+  # Ger the version from the git repository.
+  version=$(git describe --abbrev=4 HEAD 2>/dev/null)
+
+  # Check if we are on a dirty checkout.
+  git update-index --refresh -q >/dev/null
+  dirty=$(git diff-index --name-only HEAD 2>/dev/null)
+  if [ -n "$dirty" ]; then
+    version="$version-dirty"
+  fi
+else
+  echo "error: cannot get project version." 1>&2
+  exit 1
+fi
+
+echo "$version"
+