cmake_minimum_required(VERSION 2.8.12) project(CheckOBJCCompilerFlag) include(CheckOBJCCompilerFlag) if(CMAKE_COMPILER_IS_GNUOBJC) set(COMPILER_FLAG -fobjc-direct-dispatch) else() set(COMPILER_FLAG -fobjc-gc) endif() CHECK_OBJC_COMPILER_FLAGS(${COMPILER_FLAG} HAS_COMPILER_FLAG) if(NOT HAS_COMPILER_FLAG) message(SEND_ERROR "Test fail: HAS_COMPILER_FLAG: ${COMPILER_FLAG}") endif