cmake_minimum_required(VERSION 3.8) project(CheckIPOSupported-Fortran LANGUAGES Fortran) cmake_policy(SET CMP0069 NEW) include(CheckIPOSupported) check_ipo_supported(RESULT ipo_supported OUTPUT ipo_output) if(ipo_supported) set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE) elseif(CMake_TEST_IPO_WORKS_Fortran) string(REPLACE "\n" "\n " ipo_output "${ipo_output}") message(FATAL_ERROR "IPO expected to work, but the check failed:\n ${ipo_output}") endif() add_library(foo foo.f) add_executable(CheckIPOSupported-Fortran main.f) target_link_libraries(CheckIPOSupported-Fortran PUBLIC foo) enable_testing() add_test(NAME CheckIPOSupported-Fortran COMMAND CheckIPOSupported-Fortran)