-void warning PVPROTO ((const char *format, ...)) ATTRIBUTE_PRINTF_1;
-void error PVPROTO ((const char *format, ...)) ATTRIBUTE_PRINTF_1;
-void fatal PVPROTO ((const char *format, ...))
- ATTRIBUTE_PRINTF_1 ATTRIBUTE_NORETURN;
+#ifndef GCC_ERRORS_H
+#define GCC_ERRORS_H
+
+extern void warning (const char *, ...) ATTRIBUTE_PRINTF_1 ATTRIBUTE_COLD;
+extern void error (const char *, ...) ATTRIBUTE_PRINTF_1 ATTRIBUTE_COLD;
+extern void fatal (const char *, ...) ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_1 ATTRIBUTE_COLD;
+extern void internal_error (const char *, ...) ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_1 ATTRIBUTE_COLD;
+extern const char *trim_filename (const char *);