Function ( GitGetVersion GIT_ROOT OUT_MAJOR OUT_MINOR OUT_PATCH OUT_BUILD OUT_HASH )

    If ( NOT EXISTS "${GIT_ROOT}/.git" )
        Return ( )
    EndIf ( )

    Message ( "" )

    # Execute process to get git revisions
    Execute_Process ( COMMAND
                        bash -c "git -C ${GIT_ROOT} show-ref --tags | egrep 'refs\/tags\/v?[0-9]+\.[0-9]+(\.[0-9]+(\.[0-9]+))' | head -1"
                      RESULT_VARIABLE
                        GIT_RET
                      OUTPUT_VARIABLE
                        GIT_REV
                      ERROR_VARIABLE
                        GIT_ERR )
    If ( NOT ${GIT_RET} EQUAL 0 )
        Message ( FATAL_ERROR "Unable to get git revisions! ${GIT_RET}" )
    EndIf ( )
    If ( "${GIT_REV}" STREQUAL "" )
        Return ()
    EndIf ()

    # Split the git revision string
    String ( REPLACE " " ";" SPLIT ${GIT_REV} )
    List ( LENGTH SPLIT COUNT )
    If ( NOT ${COUNT} EQUAL 2 )
        Return ( )
    EndIf ( )
    List ( GET SPLIT 0 HASH )
    List ( GET SPLIT 1 VERSION )

    # Split the version
    String ( STRIP "${VERSION}" SPLIT )
    String ( REGEX REPLACE "refs?\/tags?\/v?" "" SPLIT ${SPLIT} )
    String ( REPLACE "." ";" SPLIT ${SPLIT} )
    List ( LENGTH SPLIT COUNT )
    If ( ${COUNT} LESS 2 )
        Message ( FATAL_ERROR "Unable to parse version string!" )
    EndIf ( )

    # major
    List ( GET SPLIT 0 TMP )
    Set ( ${OUT_MAJOR} ${TMP} PARENT_SCOPE )

    # minor
    List ( GET SPLIT 1 TMP )
    Set ( ${OUT_MINOR} ${TMP} PARENT_SCOPE )

    # patch
    If ( ${COUNT} GREATER 2 )
        List ( GET SPLIT 2 TMP )
        Set ( ${OUT_PATCH} ${TMP} PARENT_SCOPE )
    EndIf ( )

    # build
    If ( ${COUNT} GREATER 3 )
        List ( GET SPLIT 3 TMP )
        Set ( ${OUT_BUILD} ${TMP} PARENT_SCOPE )
    EndIf ( )

    # hash
    Set ( ${OUT_HASH} ${HASH} PARENT_SCOPE )

EndFunction ( )