Subject: Re: bug#25706: 26.0.50; Slow C file fontification

From: Lars Ingebrigtsen <[email-masked]>
Date: Mon, 30 Nov 2020 12:26:18 +0100

Sujith <[email-masked]> writes:

> On a machine that is not very high-powered, opening some C files
> and trying to edit/view them is very slow.
>
> For example:
> https://raw.githubusercontent.com/qca/qcamain_open_hal_public/master/hal/ar9300/osprey_reg_map_macro.h
>
> This is a large file and filled with macros.
> Is there any way to view this without disabling font-lock entirely ?

(This bug report unfortunately got no response at the time.)

I tried reproducing this on a pretty new laptop, and opening the file in
question (with your settings) took less than a second with Emacs 28.

You say "very slow", but not what kind of time scale you mean -- one
second or one minute or something.

Are you still seeing this issue in more recent versions of Emacs?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no