+/* GNU C allows the programmer to declare that certain functions take
+ printf-like arguments, never return, etc. Conditionalize these
+ declarations on whether gcc is in use. */
+#if __GNUC__ > 1
+#define ATTRIBUTE(X) __attribute__ (X)
+#else
+#define ATTRIBUTE(X)
+#endif
+
+/* Marks a function argument as possibly not used. */
+#define UNUSED ATTRIBUTE ((unused))
+
+/* Marks a function that will never return. */
+#define NO_RETURN ATTRIBUTE ((noreturn))
+
+/* Mark a function as taking a printf- or scanf-like format
+ string as its FMT'th argument and that the FIRST'th argument
+ is the first one to be checked against the format string. */
+#define PRINTF_FORMAT(FMT, FIRST) ATTRIBUTE ((format (__printf__, FMT, FIRST)))
+