extern Lisp_Object Vgutter_size[4];
extern Lisp_Object Vgutter_border_width[4];
void update_frame_gutters (struct frame *f);
+void mark_gutters (struct frame* f);
void init_frame_gutters (struct frame *f);
void init_device_gutters (struct device *d);
void init_global_gutters (struct device *d);