Re: bug-reference-prog-mode slows down CC Mode's scrolling by ~7%

[Eli Zaretskii]

> Date: Thu, 2 Sep 2021 19:24:51 +0000
> From: Alan Mackenzie <acm@muc.de>
> Cc: emacs-devel@gnu.org
> 
> In words (;-), only the first function on jit-lock-functions should be
> able to expand the region which gets `fontified' text properties.  This
> expanded region will then be supplied to the subsequent functions.
> 
> Given how little used the `jit-lock-bounds' mechanism is (there is one
> function in Emacs, font-lock-default-fontify-region, which uses it, and
> a web search revealed only a single other instance, in lsp-mode on
> git-hub), this shouldn't cause problems.  In fact, I'm not sure the
> lsp-mode use of it is even correct.

Bother: this is not future-proof, and certainly isn't scalable.  If we
are changing the protocol, can we instead come up with a more scalable
change, so that functions won't "fight" in the future who gets to be
"the first"?