cmake: update git version every build

CMakeLists.txt

@@ -119,6 +119,19 @@ ADD_CUSTOM_TARGET(generated_headers
 ADD_DEPENDENCIES(${PROJECT_AWE_NAME} generated_headers)
 # }}}
 
+# {{{ version stamp
+IF(BUILD_FROM_GIT)
+    ADD_CUSTOM_TARGET(version_stamp ALL
+                      COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/build-utils/git-version-stamp.sh
+                              ${VERSION_STAMP_FILE}
+                              ${CMAKE_CURRENT_BINARY_DIR}/awesome-version-internal.h
+                      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+
+    ADD_DEPENDENCIES(${PROJECT_AWE_NAME} version_stamp)
+    ADD_DEPENDENCIES(${PROJECT_AWECLIENT_NAME} version_stamp)
+ENDIF()
+# }}}
+
 # {{{ Manpages.
 IF(GENERATE_MANPAGES)
 

awesomeConfig.cmake

@@ -58,16 +58,23 @@ IF(GENERATE_MANPAGES)
 ENDIF()
 # }}}
 
+# {{{ git version stamp
 # If this is a git repository...
 IF(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git/HEAD)
-    # ...update version
     IF(GIT_EXECUTABLE)
+        # get current version
         EXECUTE_PROCESS(COMMAND ${GIT_EXECUTABLE} describe
                         WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
                         OUTPUT_VARIABLE VERSION
                         OUTPUT_STRIP_TRAILING_WHITESPACE)
+        # file the git-version-stamp.sh script will look into
+        SET(VERSION_STAMP_FILE ${CMAKE_CURRENT_BINARY_DIR}/.version_stamp)
+        FILE(WRITE ${VERSION_STAMP_FILE} ${VERSION})
+        # create a version_stamp target later
+        SET(BUILD_FROM_GIT TRUE)
     ENDIF()
 ENDIF()
+# }}}
 
 # {{{ Required libraries
 #

build-utils/git-version-stamp.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+#
+# $1 file containing the last git-describe output
+# $2 the file in which to update the version string
+#
+# TODO: proper error handling
+
+die() {
+	echo "$0: WARNING: version stamp update failed."
+	#exit 1 # not important enough to stop the build.
+	exit 0
+}
+
+STAMP=`cat "$1" 2> /dev/null`
+CURRENT=`git-describe 2>/dev/null`
+
+if [[ -z "$STAMP" || -z "$CURRENT" ]]; then
+	die
+fi
+
+if [ "$STAMP" != "$CURRENT" ]; then
+	echo "git version changed: $STAMP -> $CURRENT"
+	sed -e s/$STAMP/$CURRENT/g "$2" 1> "$2.new" || die
+	mv "$2.new" "$2"
+	echo -n "$CURRENT" > "$1"
+fi