/* If gcc is being used to compile Exim, we can use its facility for checking
the arguments of printf-like functions. This is done by a macro. */
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__clang__)
#define PRINTF_FUNCTION(A,B) __attribute__((format(printf,A,B)))
#else
#define PRINTF_FUNCTION(A,B)