+/* This function is capable of finding the absolute path to a
+ source file, and opening it, provided you give it a FILENAME. Both the
+ DIRNAME and FULLNAME are only added suggestions on where to find the file.
+
+ FILENAME should be the filename to open.
+ DIRNAME is the compilation directory of a particular source file.
+ Only some debug formats provide this info.
+ FULLNAME can be the last known absolute path to the file in question.
+ Space for the path must have been malloc'd. If a path substitution
+ is applied we free the old value and set a new one.
+
+ On Success
+ A valid file descriptor is returned (the return value is positive).
+ FULLNAME is set to the absolute path to the file just opened.
+ The caller is responsible for freeing FULLNAME.
+
+ On Failure
+ An invalid file descriptor is returned (the return value is negative).
+ FULLNAME is set to NULL. */
+extern int find_and_open_source (const char *filename,
+ const char *dirname,
+ char **fullname);
+