advice after fontify region with c-mode

advice after fontify region with c-mode

[Filippo Argiolas]

Hi,

with [1] I'd like to run a function after fontification is completed.

At the moment I'm doing something like this:
         (add-function :after (local 'font-lock-fontify-region-function)
                       #'my-fontify-region-function))

This runs in a hook for eglot-managed-hook.

While this works pretty well with c-ts-mode I'm having some issues
with c-mode because they have a custom fontification function that
extends the region to fontify before funcalling the default fontify
region function.

Relevant code in cc-mode.el is:
- at init
  (make-local-variable 'font-lock-fontify-region-function)
  (setq font-lock-fontify-region-function 'c-font-lock-fontify-region)

- at the end of c-font-lock-fontify-region
     (funcall (default-value 'font-lock-fontify-region-function)
          new-beg new-end verbose)

Problem is my function gets called after c-font-lock-fontify (as I
wanted) but with the original beg end values instead of the extended
new-beg and new-end values.

What am I missing? Any suggestions?

Thanks,
Filippo


1. https://github.com/fargiolas/clangd-inactive-regions

Re: advice after fontify region with c-mode

[Filippo Argiolas]

On Thu, Sep 14, 2023 at 10:30 PM Filippo Argiolas
<filippo.argiolas@gmail.com> wrote:
> At the moment I'm doing something like this:
>          (add-function :after (local 'font-lock-fontify-region-function)
>                        #'my-fontify-region-function))

Apparently using local here ends up calling my function after
c-fontify-region-function while I want it to be called after default
fontify region.
This:
         (add-function :after (default-value 'font-lock-fontify-region-function)
                       #'clangd-inactive-regions--fontify))

Seems to do the trick and my function gets properly chained to the
major mode one with the new extended region.
Still open to feedback and suggestions if anyone wants to chime in!

Filippo