bug#52157: CC Mode 5.35.1 (Profiler-Report); Objective C support extremely slow

Hello again, Po.

On Sun, Nov 28, 2021 at 16:11:15 +0800, Po Lu via CC-Mode-help wrote:
> Package: cc-mode

> Emacs  : GNU Emacs 29.0.50 (build 358, x86_64-pc-linux-gnu, GTK+ Version 3.24.30, cairo version 1.17.4)
>  of 2021-11-28
> Package: CC Mode 5.35.1 (Profiler-Report)
> Buffer Style: nil
> c-emacs-features: (pps-extended-state col-0-paren posix-char-classes gen-string-delim gen-comment-delim syntax-properties 1-bit)

> Open src/nsterm.m from Emacs master, and immediately go to line 603.

> Once you try to move around after going to line 603, Emacs will lock up
> and later become extremely slow.

I've committed a patch to the emacs-28 branch which I'm pretty sure has
fixed it.

The problem was in the code analysis, where a "struct foo {" wasn't
being properly recognised as a type.  A fight ensued between two bits of
code, one of which marked it as a type, the other then unmarking it, in
a fairly tight loop.

Anyhow, I'm closing the bug with this post.  If there're still problems
in the area, we can open it again.

[ .... ].

-- 
Alan Mackenzie (Nuremberg, Germany).