/* Only enable __attribute__() for compilers known to support it. */
#if !defined(__clang__) && !defined(__GNUC__)
-# define __attribute__(x) /**/
+# if !defined(__attribute__)
+# define __attribute__(x) /**/
+# endif
#endif
#if defined(COLLECT_DEBUG) && COLLECT_DEBUG && defined(__GNUC__) && __GNUC__