+[
+AC_CHECK_HEADER([sys/mman.h],
+ [libffi_header_sys_mman_h=yes], [libffi_header_sys_mman_h=no])
+AC_CHECK_FUNC([mmap], [libffi_func_mmap=yes], [libffi_func_mmap=no])
+if test "$libffi_header_sys_mman_h" != yes \
+ || test "$libffi_func_mmap" != yes; then