getgit.cmake

# the git.cmake module is part of the standard distribution
find_package(Git)
if(NOT GIT_FOUND)
  MESSAGE(FATAL_ERROR "Git not found!.")
endif()

MACRO(Gitversion_GET_REVISION dir variable)
  EXECUTE_PROCESS(COMMAND ${GIT_EXECUTABLE} rev-list HEAD --count
    OUTPUT_VARIABLE ${variable}
    OUTPUT_STRIP_TRAILING_WHITESPACE)
ENDMACRO(Gitversion_GET_REVISION)

MACRO(Gitversion_GET_HASH dir variable)
  EXECUTE_PROCESS(COMMAND ${GIT_EXECUTABLE} rev-parse --short HEAD
    OUTPUT_VARIABLE ${variable}
    OUTPUT_STRIP_TRAILING_WHITESPACE)
ENDMACRO(Gitversion_GET_HASH)

MACRO(Gitversion_GET_DATE dir variable)
  EXECUTE_PROCESS(COMMAND ${GIT_EXECUTABLE} show -s --format=%ct
    OUTPUT_VARIABLE ${variable}
    OUTPUT_STRIP_TRAILING_WHITESPACE)
ENDMACRO(Gitversion_GET_DATE)

Gitversion_GET_REVISION(. ProjectRevision)
Gitversion_GET_HASH(. ProjectHash)
Gitversion_GET_DATE(. ProjectDate)

# write a file with the APPVERSION define
MATH(EXPR ProjectRevision "${ProjectRevision}+2107")
file(WRITE appversion.h.txt "#define APPVERSION ${ProjectRevision}\n#define APPHASH \"${ProjectHash}\"\n#define APPDATE ${ProjectDate}\n")
# copy the file to the final header only if the version changes
# reduces needless rebuilds

execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different
                        appversion.h.txt ${CMAKE_CURRENT_LIST_DIR}/appversion.h)