Re: Slow fontification in C mode buffers

[Alan Mackenzie]

Hi, Geoff

On Wed, Dec 21, 2011 at 09:33:09PM +0800, Geoff Gole wrote:
> 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.

Thanks for the report.

The problem here is that CC Mode normally steps back and forth through a
source code using brace positions as "ladder rungs".  A sequence of
#defines is, sadly, a "brace desert".

If you're running GNU Emacs, an optimisation was introduced in Emacs
23.3 which gave a considerable speed-up to such code.  This optimisation
found its way into the XEmacs CC Mode package in September.  I _hope_
your version of Emacs is prior to one of these, in which case upgrading
will give you this benefit.

Otherwise, I'll be asking you if you're prepared to give me some
timings.

Here's hoping.....

-- 
Alan Mackenzie (Nuremberg, Germany).