+/* The file name as given on the command line.
+ Not named "input_file" because Flex uses this name for an argument,
+ and therefore GCC warns about a name clash. */
+extern uniqstr grammar_file;
+
+/* The current file name. Might change with %include, or with #line. */
+extern uniqstr current_file;
+
+/* The computed base for output file names. */
+extern char *all_but_ext;