Subject: Re: bug#30367: 26.0.91; CC-Mode: Major slowdown when isearching big C++ file.

From: Alan Mackenzie <[email-masked]>
Date: Tue, 20 Mar 2018 18:49:47 +0000

Hello, Bastian.

On Fri, Feb 09, 2018 at 10:16:53 +0100, Bastian Beischer wrote:
> Hello Alan,

> Alan Mackenzie <[email-masked]> writes:

[ .... ]

> > Would you please try out the following patch on real code, and either
> > confirm to me that it fixes the bug, or tell me what it breaks.  Thanks!

> > diff -r e8b2c6141f97 cc-engine.el
> > --- a/cc-engine.el	Fri Feb 02 20:34:15 2018 +0000
> > +++ b/cc-engine.el	Thu Feb 08 18:39:40 2018 +0000
> > @@ -10547,13 +10547,6 @@
> >  		      (looking-at c-return-key))
> >  		 (setq braceassignp t)
> >  		 nil)
> > -		((and c-has-compound-literals
> > -		      (eq (char-after) ?,))
> > -		 (save-excursion
> > -		   (when (and (c-go-up-list-backward nil lim)
> > -			      (eq (char-after) ?\())
> > -		     (setq braceassignp t)
> > -		     nil)))
> >  		((eq (char-after) ?=)
> >  		 ;; We've seen a =, but must check earlier tokens so
> >  		 ;; that it isn't something that should be ignored.

> > [ .... ]

> Yes, this patch fixes the slowdown. But since I don't understand what
> the original commit which introduced the slowdown tried to fix I cannot
> comment on whether or not its the right thing to do within the context
> of that commit.

Thanks for the prompt, positive reply.  I'm afraid I can't remember
either, what the original patch was for.

> I will run emacs with the patch included for a while and will let you
> know in case I find any problems!

Nothing heard from you in the meantime.  Good!

> Thanks for tackling this so quickly!

Sorry I've not maintained this speed in committing it.  I have now
committed the fix, in revision 16559146f9db1b36d5e8b6c92edb5bb36fafdb85,
and I'm closing the bug.

> >> > Cheers
> >> > Bastian

-- 
Alan Mackenzie (Nuremberg, Germany).