cmake/Modules/LLVMCheckCompilerLinkerFlag.cmake

   1 include(CMakePushCheckState)
   2 include(CheckCompilerFlag)
   3
   4 function(llvm_check_compiler_linker_flag lang flag out_var)
   5   # If testing a flag with check_compiler_flag, it gets added to the compile
   6   # command only, but not to the linker command in that test. If the flag
   7   # is vital for linking to succeed, the test would fail even if it would
   8   # have succeeded if it was included on both commands.
   9   #
  10   # Therefore, try adding the flag to CMAKE_REQUIRED_FLAGS, which gets
  11   # added to both compiling and linking commands in the tests.
  12
  13   cmake_push_check_state()
  14   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${flag}")
  15   check_compiler_flag("${lang}" "" ${out_var})
  16   cmake_pop_check_state()
  17 endfunction()