Add CMake script to determine project version based on git describe

Author: jimmysoda

CMakeLists.txt

@@ -20,10 +20,10 @@ set(CMAKE_INSTALL_PREFIX "${CMAKE_BINARY_DIR}" CACHE STRING "CMake install prefi
 # Do not use a suffix for RelWithDebInfo
 set(CMAKE_DEBUG_POSTFIX "d" CACHE STRING "CMake debug suffix")
 set(CMAKE_RELWITHDEBINFO_POSTFIX "" CACHE STRING "CMake RelWithDebInfo suffix")
-
 set(PDALC_ENABLE_CODE_COVERAGE ON CACHE BOOL "Enable code coverage calculation")
 set(PDALC_GCC_PARAM_GGC_MIN_HEAPSIZE "131072" CACHE STRING "GCC garbage collection minimum heap size")
 
+include(ObtainProjectVersion)
 include_directories("${CMAKE_SOURCE_DIR}/source")
 
 if(CMAKE_COMPILER_IS_GNUCXX)

cmake/ObtainProjectVersion.cmake

@@ -0,0 +1,44 @@
+# CMake script to derive project version from repository info
+
+find_package(Git)
+
+# Use `git describe` to derive patch and build info
+if(GIT_FOUND)
+	execute_process(COMMAND "${GIT_EXECUTABLE}" "describe" "--tags" "--long"
+		OUTPUT_STRIP_TRAILING_WHITESPACE OUTPUT_VARIABLE GIT_DESCRIBE_OUTPUT
+		ERROR_STRIP_TRAILING_WHITESPACE ERROR_VARIABLE GIT_DESCRIBE_ERROR)
+
+	# We use tags with the three version numbers
+	# Use the remainder of the `git describe` output for the build ID
+	if(GIT_DESCRIBE_OUTPUT MATCHES "^([0-9]+)\\.([0-9]+)\\.([0-9]+)-([0-9]+)-g([a-f0-9]+)$")
+		string(REGEX REPLACE "([0-9]+).*" "\\1" MAJOR_VERSION ${GIT_DESCRIBE_OUTPUT})
+		string(REGEX REPLACE "([0-9]+)\\.([0-9]+).*" "\\2" MINOR_VERSION ${GIT_DESCRIBE_OUTPUT})
+		string(REGEX REPLACE "([0-9]+)\\.([0-9]+)\\.([0-9]+).*" "\\3" PATCH_VERSION ${GIT_DESCRIBE_OUTPUT})
+		string(REGEX REPLACE ".*-(.*)-.*" "\\1" COMMIT_COUNT ${GIT_DESCRIBE_OUTPUT})
+		string(REGEX REPLACE ".*-g(.*)" "\\1" COMMIT_ID ${GIT_DESCRIBE_OUTPUT})
+		set(BUILD_ID "build ${COMMIT_COUNT} (${COMMIT_ID})")
+	else()
+	message(WARNING "Could not derive version and build ID: 'git describe' command output was \"${GIT_DESCRIBE_OUTPUT}\" - ${GIT_DESCRIBE_ERROR}")
+	endif()
+
+	# Suffix BUILD_ID with " (with uncommitted changes)" if `git status --porcelain` does not return an empty string
+	execute_process(COMMAND "${GIT_EXECUTABLE}" "status" "--porcelain"
+		OUTPUT_STRIP_TRAILING_WHITESPACE OUTPUT_VARIABLE GIT_STATUS_OUTPUT)
+
+	if(NOT "${GIT_STATUS_OUTPUT}" STREQUAL "")
+		string(APPEND BUILD_ID " with uncommitted changes")
+	endif()
+else()
+	message(WARNING "Could not derive version and build ID: Git not found")
+endif()
+
+set(${PROJECT_NAME}_VERSION_MAJOR ${MAJOR_VERSION})
+set(${PROJECT_NAME}_VERSION_MINOR ${MINOR_VERSION})
+set(${PROJECT_NAME}_VERSION_PATCH ${PATCH_VERSION})
+set(${PROJECT_NAME}_VERSION "${MAJOR_VERSION}.${MINOR_VERSION}.${PATCH_VERSION}")
+
+string (TOUPPER "${PROJECT_NAME}" PROJECT_NAME_UPPERCASE)
+set(${PROJECT_NAME_UPPERCASE}_VERSION_MAJOR ${${PROJECT_NAME}_VERSION_MAJOR})
+set(${PROJECT_NAME_UPPERCASE}_VERSION_MINOR ${${PROJECT_NAME}_VERSION_MINOR})
+set(${PROJECT_NAME_UPPERCASE}_VERSION_PATCH ${${PROJECT_NAME}_VERSION_PATCH})
+set(${PROJECT_NAME_UPPERCASE}_VERSION ${${PROJECT_NAME}_VERSION})