check_library_exists(c clock_get_time "mach/time.h" HAVE_CLOCK_GET_TIME)
if(NOT HAVE_CLOCK_GET_TIME)
message(FATAL_ERROR "Didn't find clock_gettime() or clock_get_time!")
endif()
check_library_exists(c clock_get_time "mach/time.h" HAVE_CLOCK_GET_TIME)
if(NOT HAVE_CLOCK_GET_TIME)
message(FATAL_ERROR "Didn't find clock_gettime() or clock_get_time!")
endif()