Make struct font_drivers read-only

This simplifies the code a bit, and makes the structs more
shareable and less likely to become corrupt.
* src/alloc.c (cleanup_vector):
* src/font.c (valid_font_driver, font_prepare_cache)
(font_finish_cache, font_get_cache, font_clear_cache)
(register_font_driver, font_update_drivers):
* src/font.h (struct font, struct font_driver_list)
(valid_font_driver):
struct font_drivers are now const.
* src/font.c, src/ftcrfont.c, src/ftfont.c, src/nsfont.m, src/xfont.c:
Omit no-longer-necessary decls.
* src/ftcrfont.c (syms_of_ftcrfont):
* src/ftxfont.c (syms_of_ftxfont):
* src/xftfont.c (syms_of_xftfont):
Omit no-longer-necessary initialization code.
* src/ftcrfont.c (ftcrfont_driver):
* src/ftfont.c (ftfont_driver):
* src/ftxfont.c (ftxfont_driver):
* src/macfont.m (macfont_driver):
* src/nsfont.m (nsfont_driver):
* src/xfont.c (xfont_driver):
* src/xftfont.c (xftfont_driver):
Use C99-style initializer for ease of maintenance, and make it const.
* src/ftcrfont.c, src/ftxfont.c, src/xftfont.c:
Refer to functions like ftfont_text_extents directly.
* src/ftfont.c (ftfont_get_cache, ftfont_list, ftfont_list_family)
(ftfont_has_char, ftfont_encode_char, ftfont_text_extents)
(ftfont_get_bitmap, ftfont_anchor_point, ftfont_otf_capability)
(ftfont_variation_glyphs, ftfont_filter_properties)
(ftfont_combining_capability):
* src/xfont.c (xfont_get_cache):
Now extern, so that other modules’ struct font_drivers can use
them directly.
* src/macfont.m (macfont_descriptor_entity):
* src/nsfont.m (nsfont_open):
Use constant directly; this is clearer.

1 files changed, 17 insertions, 30 deletions

diff --git a/src/macfont.m b/src/macfont.m
index b3a2fb84205..b2f3dff3097 100644
--- a/src/macfont.m
+++ b/src/macfont.m
@@ -38,8 +38,6 @@ Original author: YAMAMOTO Mitsuharu
 
 #include <libkern/OSByteOrder.h>
 
-static struct font_driver macfont_driver;
-
 static double mac_font_get_advance_width_for_glyph (CTFontRef, CGGlyph);
 static CGRect mac_font_get_bounding_rect_for_glyph (CTFontRef, CGGlyph);
 static CFArrayRef mac_font_create_available_families (void);
@@ -893,7 +891,7 @@ macfont_descriptor_entity (CTFontDescriptorRef desc, Lisp_Object extra,
 
   entity = font_make_entity ();
 
-  ASET (entity, FONT_TYPE_INDEX, macfont_driver.type);
+  ASET (entity, FONT_TYPE_INDEX, Qmac_ct);
   ASET (entity, FONT_REGISTRY_INDEX, Qiso10646_1);
 
   macfont_store_descriptor_attributes (desc, entity);
@@ -1663,34 +1661,23 @@ static int macfont_variation_glyphs (struct font *, int c,
                                      unsigned variations[256]);
 static void macfont_filter_properties (Lisp_Object, Lisp_Object);
 
-static struct font_driver macfont_driver =
+static struct font_driver const macfont_driver =
   {
-    LISPSYM_INITIALLY (Qmac_ct),
-    0,                          /* case insensitive */
-    macfont_get_cache,
-    macfont_list,
-    macfont_match,
-    macfont_list_family,
-    macfont_free_entity,
-    macfont_open,
-    macfont_close,
-    NULL,                       /* prepare_face */
-    NULL,                       /* done_face */
-    macfont_has_char,
-    macfont_encode_char,
-    macfont_text_extents,
-    macfont_draw,
-    NULL,                       /* get_bitmap */
-    NULL,                       /* free_bitmap */
-    NULL,                       /* anchor_point */
-    NULL,                       /* otf_capability */
-    NULL,                       /* otf_drive */
-    NULL,                       /* start_for_frame */
-    NULL,                       /* end_for_frame */
-    macfont_shape,
-    NULL,                       /* check */
-    macfont_variation_glyphs,
-    macfont_filter_properties,
+  type: LISPSYM_INITIALLY (Qmac_ct),
+  get_cache: macfont_get_cache,
+  list: macfont_list,
+  match: macfont_match,
+  list_family: macfont_list_family,
+  free_entity: macfont_free_entity,
+  open: macfont_open,
+  close: macfont_close,
+  has_char: macfont_has_char,
+  encode_char: macfont_encode_char,
+  text_extents: macfont_text_extents,
+  draw: macfont_draw,
+  shape: macfont_shape,
+  get_variation_glyphs: macfont_variation_glyphs,
+  filter_properties: macfont_filter_properties,
   };
 
 static Lisp_Object