check_c_source_compiles(
        "
            #include <sys/mman.h>
            int main(void)
            {
                mmap((void *)0, 0, PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
                return 0;
            }
        "
        HAVE_MMAP_MAP_ANONYMOUS
    )

elseif(NOT HAVE_MMAP_MAP_ANON AND NOT HAVE_MMAP_MAP_ANONYMOUS)