-extern guint32 GetLastError(void);
-extern void SetLastError(guint32 code);
-extern guint32 errno_to_WSA (guint32 code, const char *function_name);
+G_BEGIN_DECLS
+
+guint32 GetLastError (void);
+void SetLastError (guint32 code);
+guint32 errno_to_WSA (guint32 code, const char *function_name);
+gint _wapi_get_win32_file_error (gint err);
+void _wapi_error_cleanup (void);
+
+G_END_DECLS