enable_language(Swift) include(CheckSourceCompiles) set(Swift 1) # test that this is tolerated check_source_compiles(Swift "baz()" SHOULD_FAIL) if(SHOULD_FAIL) message(SEND_ERROR "invalid Swift source didn't fail.") endif() check_source_compiles(Swift "print(\"Hello, CMake\")" SHOULD_BUILD) if(NOT SHOULD_BUILD) message(SEND_ERROR "Test failed for valid Swift source.") endif()