+#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later. */
+# if ! defined __GNUC__ || __GNUC__ < 2 || \
+(__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
+# define __attribute__(Spec) /* empty */
+# endif
+#endif
+
+#ifndef ATTRIBUTE_UNUSED
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#endif
+