execute_process(
    COMMAND git rev-parse --short HEAD
    WORKING_DIRECTORY ${SOURCE_DIR}
    OUTPUT_VARIABLE GIT_HASH_SHORT
    OUTPUT_STRIP_TRAILING_WHITESPACE
)

execute_process(
    COMMAND git rev-parse HEAD
    WORKING_DIRECTORY ${SOURCE_DIR}
    OUTPUT_VARIABLE GIT_HASH_LONG
    OUTPUT_STRIP_TRAILING_WHITESPACE
)

# Check for uncommitted changes
execute_process(
    COMMAND git diff-index --quiet HEAD --
    WORKING_DIRECTORY ${SOURCE_DIR}
    RESULT_VARIABLE GIT_DIRTY
)

# If GIT_DIRTY is non-zero, there are local modifications
if(NOT GIT_DIRTY EQUAL 0)
    set(GIT_HASH_SHORT "${GIT_HASH_SHORT}+")
    set(GIT_HASH_LONG "${GIT_HASH_LONG}+")
endif()

file(WRITE ${OUTPUT_FILE}
"#ifndef GIT_VERSION_H
#define GIT_VERSION_H
#define GIT_COMMIT_HASH_SHORT \"${GIT_HASH_SHORT}\"
#define GIT_COMMIT_HASH_LONG \"${GIT_HASH_LONG}\"
#endif
")