Optimise font locking in long enum definitions.

4 files changed, 31 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 9e490a1e367..ab8572b7f93 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,12 @@
+2012-01-08  Alan Mackenzie  <acm@muc.de>
+
+        Optimise font locking in long enum definitions.
+
+        * progmodes/cc-fonts.el (c-font-lock-declarations): Add an extra
+        arm to a cond form to handle enums.
+        * progmodes/cc-langs.el (c-enums-contain-decls): New lang variable.
+        * progmodes/cc-mode.el (c-font-lock-fontify-region): Correct a typo.
+
 2012-01-07  Paul Eggert  <eggert@cs.ucla.edu>
 
         * files.el (move-file-to-trash): Preserve default file modes on error.
diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index ee5fb1bd086..f52864df809 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -1428,6 +1428,21 @@ casts and declarations are fontified.  Used on level 2 and higher."
               (c-fontify-recorded-types-and-refs)
               nil)
 
+             ((and (not c-enums-contain-decls)
+                   ;; An optimisation quickly to eliminate scans of long enum
+                   ;; declarations in the next cond arm.
+                   (let ((paren-state (c-parse-state)))
+                     (and
+                      (numberp (car paren-state))
+                      (save-excursion
+                        (goto-char (car paren-state))
+                        (c-backward-token-2)
+                        (or (looking-at c-brace-list-key)
+                            (progn
+                              (c-backward-token-2)
+                              (looking-at c-brace-list-key)))))))
+              t)
+
              (t
               ;; Are we at a declarator?  Try to go back to the declaration
               ;; to check this.  If we get there, check whether a "typedef"
diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index b565cf98b3c..fafbfb70552 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -2938,6 +2938,12 @@ expression is considered to be a type."
         (consp (c-lang-const c-<>-arglist-kwds))))
 (c-lang-defvar c-recognize-<>-arglists (c-lang-const c-recognize-<>-arglists))
 
+(c-lang-defconst c-enums-contain-decls
+  "Non-nil means that an enum structure can contain declarations."
+  t nil
+  java t)
+(c-lang-defvar c-enums-contain-decls (c-lang-const c-enums-contain-decls))
+
 (c-lang-defconst c-recognize-paren-inits
   "Non-nil means that parenthesis style initializers exist,
 i.e. constructs like
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index 600d4fc8b56..b74d878516d 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -1158,7 +1158,7 @@ Note that the style variables are always made local to the buffer."
   ;; Effectively advice around `font-lock-fontify-region' which extends the
   ;; region (BEG END), for example, to avoid context fontification chopping
   ;; off the start of the context.  Do not do anything if it's already been
-  ;; done (i.e. from and after-change fontification.  An example (C++) where
+  ;; done (i.e. from an after-change fontification.  An example (C++) where
   ;; this used to happen is this:
   ;;
   ;;     template <typename T>