-extern int font_parse_xlfd (char *name, Lisp_Object font);
-extern int font_unparse_xlfd (Lisp_Object font, int pixel_size,
- char *name, int bytes);
-extern int font_unparse_fcname (Lisp_Object font, int pixel_size,
- char *name, int bytes);
-extern void register_font_driver (struct font_driver *driver, FRAME_PTR f);
-extern void free_font_driver_list (FRAME_PTR f);
-extern Lisp_Object font_update_drivers (FRAME_PTR f, Lisp_Object list);
-extern Lisp_Object font_range (ptrdiff_t, ptrdiff_t *,
+extern int font_parse_xlfd (char *name, ptrdiff_t len, Lisp_Object font);
+extern ptrdiff_t font_unparse_xlfd (Lisp_Object font, int pixel_size,
+ char *name, int bytes);
+extern void register_font_driver (struct font_driver *driver, struct frame *f);
+extern void free_font_driver_list (struct frame *f);
+#ifdef ENABLE_CHECKING
+extern bool valid_font_driver (struct font_driver *);
+#else
+INLINE bool
+valid_font_driver (struct font_driver *d)
+{
+ return true;
+}
+#endif
+extern Lisp_Object font_update_drivers (struct frame *f, Lisp_Object list);
+extern Lisp_Object font_range (ptrdiff_t, ptrdiff_t, ptrdiff_t *,