GNU bug report logs - #43631
28.0.50; CC Mode multiline strings grinds performance to a halt

Previous Next

Package: emacs;

Reported by: Theodor Thornhill <theo <at> thornhill.no>

Date: Sat, 26 Sep 2020 11:18:01 UTC

Severity: normal

Found in version 28.0.50

Done: Alan Mackenzie <acm <at> muc.de>

Bug is archived. No further changes may be made.

Full log

View this message in rfc822 format

From: Dmitry Gutov <dgutov <at> yandex.ru>
To: Eli Zaretskii <eliz <at> gnu.org>, Theodor Thornhill <theo <at> thornhill.no>
Cc: 43631 <at> debbugs.gnu.org
Subject: bug#43631: 28.0.50; CC Mode multiline strings grinds performance to a halt
Date: Sat, 26 Sep 2020 22:43:05 +0300

On 26.09.2020 19:17, Eli Zaretskii wrote:
> But I'm confused why the "fast" profile starts with
> font-lock-fontify-region, whereas the "slow" profile doesn't have
> font-lock-fontify-region anywhere...

Because CC Mode doesn't use syntax-propertize-function (most major modes 
do, so we're used to seeing "slow" syntax analysis being done inside 
font-lock-fontify-region because it calls s-p-f).

CC Mode applies syntax properties inside before/after-change-functions, 
and the "slow" profile reflects that: c-before-change is featured 
prominently.
This bug report was last modified 1 year and 282 days ago.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.