Re: Slow fontification in C mode buffers

[Alan Mackenzie]

Hello, Kentaro.

On Fri, Dec 23, 2011 at 10:56:15AM +0900, Kentaro NAKAZAWA wrote:
> Hello. (sorry for my poor english ;)

> Other pattern attached.
> The file is very heavy at edit and undo.


> Geoff Gole <address@hidden> writes:

> > If another data point will help, I've also noticed *very* slow c-mode
> > fontification in a script generated header,
> > /usr/include/GL/gl_mangle.h. In case you don't have this header, a
> > copy is attached.

> > The file is basically several thousand #defines.


> // -*- mode: c++ -*-

> namespace NameSpace1 {
>   namespace NameSpace2 {

>     enum {
>       kFooBarBazType_Attribute0000    = 0x0000,       // Comment0000
>       kFooBarBazType_Attribute0001    = 0x0001,       // Comment0001
>       kFooBarBazType_Attribute0002    = 0x0002,       // Comment0002
>       kFooBarBazType_Attribute0003    = 0x0003,       // Comment0003
>
> [....]
>
>       kFooBarBazType_Attribute0220    = 0x00dc,       // Comment0220
>       kFooBarBazType_Attribute0221    = 0x00dd,       // Comment0221
>       kFooBarBazType_Attribute0222    = 0x00de,       // Comment0222
>     };

>   } // namespace Namespace2
> } // namespace Namespace1

Would you try this patch and let me know how it goes, please.


*** orig/cc-fonts.el    2012-01-06 12:27:14.000000000 +0000
--- cc-fonts.el 2012-01-06 21:48:54.000000000 +0000
***************
*** 1394,1399 ****
--- 1394,1414 ----
              (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"
*** orig/cc-langs.el    2012-01-06 12:27:14.000000000 +0000
--- cc-langs.el 2012-01-06 12:54:00.000000000 +0000
***************
*** 2930,2935 ****
--- 2930,2941 ----
                    ; generics is not yet coded in CC Mode.
  (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



> -- 
> Kentaro Nakazawa

-- 
Alan Mackenzie (Nuremberg, Germany).