enable_language(C) include(CheckCompilerFlag) # Confirm we can check the conflicting flag directly. This should pass with # or without the workaround. check_compiler_flag(C "-fembed-bitcode" result1) if(NOT result1) message(FATAL_ERROR "False negative when -fembed-bitcode tested directly") endif() # Check conflicting flag set by user or project won't cause a false negative # when testing a valid flag. This only passes with the workaround. set(CMAKE_C_FLAGS -fembed-bitcode) check_compiler_flag(C "-O" result2) if(NOT result2) message(FATAL_ERROR "False negative when -fembed-bitcode set in CMAKE_C_FLAGS") endif()