Subject: bug#23476: Slowdown in C Mode fontification [Was: bug#23476: 25.0.93; Visiting C files on master signals an error]

From: Eli Zaretskii <[email-masked]>
Date: Tue, 10 May 2016 19:04:28 +0300

> Date: Tue, 10 May 2016 07:51:32 +0000
> Cc: [email-masked], Glenn Morris <[email-masked]>
> From: Alan Mackenzie <[email-masked]>
> 
> > Btw, I noticed that CC Mode is quite a bit slower on master than it is
> > on emacs-25 (try searching for "IF_LINT" in xdisp.c), is that related
> > to these changes in any way?
> 
> Whoops!  No, this slowdown is caused by commit
> 89d1776b81ab552192ee41f13ce84ff86bda4556 on 2016-04-25, a fix for bug
> #7918.  The bug was the spurious fontification of something like "for (;
> a * b;)".
> 
> I'll see if I can find a better fix; if not, it would probably be best to
> remove the commit and leave the bug unfixed.

Since this is only on master (right?), there's no rush to revert the
commit, perhaps you or someone else will come up with a solution that
doesn't bring back bug #7918.

Thanks.