-void WXDLLEXPORT wxTrace(const wxChar *fmt ...);
-void WXDLLEXPORT wxTraceLevel(int level, const wxChar *fmt ...);
+void WXDLLEXPORT wxTrace(const wxChar *fmt ...) ATTRIBUTE_PRINTF_1;
+void WXDLLEXPORT wxTraceLevel(int level, const wxChar *fmt ...) ATTRIBUTE_PRINTF_2;