cmake_policy(PUSH)
cmake_policy(SET CMP0053 NEW) # IN_LIST operator

set(ARG_PREFIX "${PREFIX}")
set(GIT_REV "N/A")
set(GIT_DIFF "")
set(GIT_TAG "N/A")
set(GIT_BRANCH "N/A")

find_package(Git QUIET)

if(GIT_EXECUTABLE)
  execute_process(COMMAND ${GIT_EXECUTABLE} log --pretty=format:'%h' -n 1 OUTPUT_VARIABLE GIT_REV ERROR_QUIET)

  # Check whether we got any revision (which isn't always the case,
  # e.g. when someone downloaded a zip file from Github instead of a checkout)
  if(NOT "${GIT_REV}" STREQUAL "")
    execute_process(COMMAND bash -c "${GIT_EXECUTABLE} diff --quiet --exit-code || echo +" OUTPUT_VARIABLE GIT_DIFF)
    execute_process(COMMAND ${GIT_EXECUTABLE} describe --exact-match --tags OUTPUT_VARIABLE GIT_TAG ERROR_QUIET)
    execute_process(COMMAND ${GIT_EXECUTABLE} rev-parse --abbrev-ref HEAD OUTPUT_VARIABLE GIT_BRANCH)

    string(STRIP "${GIT_REV}" GIT_REV)
    string(SUBSTRING "${GIT_REV}" 1 7 GIT_REV)
    string(STRIP "${GIT_DIFF}" GIT_DIFF)
    string(STRIP "${GIT_TAG}" GIT_TAG)
    string(STRIP "${GIT_BRANCH}" GIT_BRANCH)
  endif()
endif()

configure_file("GitInfo.hpp.in" "${GIT_INFO_FILE}")

cmake_policy(POP)