+#if defined(__GNUC__) || defined(__clang__)
+# define PRINTF_FUNCTION(A,B) __attribute__((format(printf,A,B)))
+# define ARG_UNUSED __attribute__((__unused__))
+# define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
+#else
+# define PRINTF_FUNCTION(A,B)
+# define ARG_UNUSED /**/
+# define WARN_UNUSED_RESULT /**/
+#endif
+
+#ifdef WANT_DEEPER_PRINTF_CHECKS
+# define ALMOST_PRINTF(A, B) PRINTF_FUNCTION(A, B)