From f002a15267f28b6f5db98cb3fcfa3b05b5881ea7 Mon Sep 17 00:00:00 2001
From: Ghislain MARY <ghislain.mary@belledonne-communications.com>
Date: Tue, 15 Dec 2015 10:51:13 +0100
Subject: [PATCH] Improve git version header generation with CMake.

---
 coreapi/CMakeLists.txt   |  2 +-
 coreapi/gitversion.cmake | 36 +++++++++++++++++++++++++++---------
 coreapi/gitversion.h.in  |  2 +-
 3 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/coreapi/CMakeLists.txt b/coreapi/CMakeLists.txt
index 2f2d59712..87001b186 100644
--- a/coreapi/CMakeLists.txt
+++ b/coreapi/CMakeLists.txt
@@ -125,7 +125,7 @@ endif()
 
 find_package(Git)
 add_custom_target(liblinphone-git-version
-	COMMAND ${CMAKE_COMMAND} -DGIT_EXECUTABLE=${GIT_EXECUTABLE} -DWORK_DIR=${CMAKE_CURRENT_SOURCE_DIR} -DOUTPUT_DIR=${CMAKE_CURRENT_BINARY_DIR} -P ${CMAKE_CURRENT_SOURCE_DIR}/gitversion.cmake
+	COMMAND ${CMAKE_COMMAND} -DGIT_EXECUTABLE=${GIT_EXECUTABLE} -DLINPHONE_VERSION=${LINPHONE_VERSION} -DWORK_DIR=${CMAKE_CURRENT_SOURCE_DIR} -DOUTPUT_DIR=${CMAKE_CURRENT_BINARY_DIR} -P ${CMAKE_CURRENT_SOURCE_DIR}/gitversion.cmake
 	BYPRODUCTS "${CMAKE_CURRENT_BINARY_DIR}/liblinphone_gitversion.h"
 )
 
diff --git a/coreapi/gitversion.cmake b/coreapi/gitversion.cmake
index eb0f99e3c..bb20ebae5 100644
--- a/coreapi/gitversion.cmake
+++ b/coreapi/gitversion.cmake
@@ -21,14 +21,32 @@
 ############################################################################
 
 if(GIT_EXECUTABLE)
-	execute_process(
-		COMMAND ${GIT_EXECUTABLE} describe --always
-		WORKING_DIRECTORY ${WORK_DIR}
-		OUTPUT_VARIABLE GIT_REVISION
-		OUTPUT_STRIP_TRAILING_WHITESPACE
-	)
-else()
-	set(GIT_REVISION "unknown")
+	macro(GIT_COMMAND OUTPUT_VAR)
+		set(GIT_ARGS ${ARGN})
+		execute_process(
+			COMMAND ${GIT_EXECUTABLE} ${ARGN}
+			WORKING_DIRECTORY ${WORK_DIR}
+			OUTPUT_VARIABLE ${OUTPUT_VAR}
+			OUTPUT_STRIP_TRAILING_WHITESPACE
+		)
+	endmacro()
+
+	GIT_COMMAND(GIT_DESCRIBE describe --always)
+	GIT_COMMAND(GIT_TAG describe --abbrev=0)
+	GIT_COMMAND(GIT_REVISION rev-parse HEAD)
 endif()
 
-configure_file("${WORK_DIR}/gitversion.h.in" "${OUTPUT_DIR}/liblinphone_gitversion.h" @ONLY)
+if(GIT_DESCRIBE)
+	if(NOT GIT_TAG STREQUAL LINPHONE_VERSION)
+		message(FATAL_ERROR "LINPHONE_VERSION and git tag differ. Please put them identical")
+	endif()
+	set(LIBLINPHONE_GIT_VERSION "${GIT_DESCRIBE}")
+	configure_file("${WORK_DIR}/gitversion.h.in" "${OUTPUT_DIR}/liblinphone_gitversion.h" @ONLY)
+elseif(GIT_REVISION)
+	set(LIBLINPHONE_GIT_VERSION "${LINPHONE_VERSION}_${GIT_REVISION}")
+	configure_file("${WORK_DIR}/gitversion.h.in" "${OUTPUT_DIR}/liblinphone_gitversion.h" @ONLY)
+else()
+	if(NOT EXISTS "${OUTPUT_DIR}/liblinphone_gitversion.h")
+		execute_process(COMMAND ${CMAKE_COMMAND} -E touch "${OUTPUT_DIR}/liblinphone_gitversion.h")
+	endif()
+endif()
diff --git a/coreapi/gitversion.h.in b/coreapi/gitversion.h.in
index 493b4bcb1..c4664950f 100644
--- a/coreapi/gitversion.h.in
+++ b/coreapi/gitversion.h.in
@@ -18,4 +18,4 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 
 
-#define LIBLINPHONE_GIT_VERSION "@GIT_REVISION@"
\ No newline at end of file
+#define LIBLINPHONE_GIT_VERSION "@LIBLINPHONE_GIT_VERSION@"
\ No newline at end of file