message: CMake: added CLANG_FORMAT_EXECUTABLE internal cache variable
diff: cmake_minimum_required (VERSION 3.3)
  add_subdirectory(File2Include)
  +
  +if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
  + set(CLANG_FORMAT_EXECUTABLE "${CMAKE_CURRENT_SOURCE_DIR}/FormatValidation/clang-format_10.0.0.exe" CACHE INTERNAL "clang-format executable path")
  +elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux")
  + set(CLANG_FORMAT_EXECUTABLE "${CMAKE_CURRENT_SOURCE_DIR}/FormatValidation/clang-format_linux_10.0.0" CACHE INTERNAL "clang-format executable path")
  +elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin")
  + set(CLANG_FORMAT_EXECUTABLE "${CMAKE_CURRENT_SOURCE_DIR}/FormatValidation/clang-format_mac_10.0.0" CACHE INTERNAL "clang-format executable path")
  +endif()
  