bug#63390: 29.0.90; c-ts-mode fails to recognize functions in xterm.c

[Yuan Fu <casouri@gmail.com>]

> On May 17, 2023, at 11:56 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Yuan Fu <casouri@gmail.com>
>> Date: Wed, 17 May 2023 23:19:22 -0700
>> Cc: 63390@debbugs.gnu.org
>> 
>>>> Ok, so that’s because there are ifdef’s inside the function, which cuts the function into pieces and tree-sitter can’t make out a function_definition, which is what we use to fontify the function name. A function_declarator alone can be used in many places, like in an argument list for function pointers, I think?
>>> 
>>> Does this mean that on master movement by defuns will be broken around
>>> those functions?
>> 
>> Yeah, unfortunately, I’ll try accommodate for it. 
>> 
>>> 
>>>> I can fix this by fontifying top-level function_declaration, I think a top-level function_declaration should always be a function definition?
>>> 
>>> Yes, I think this would be better.
>>> 
>>>>>> Btw, function declarations in a header file are recognized as such,
>>>>>> but the names of the functions there are still correctly fontified.
>>>> 
>>>> They are fine because there’s a semicolon in the end, so the function_decalration is wrapped in a declaration node, which we (the fontification rules) recognize.
>>> 
>>> Thanks for explaining this.
>> 
>> Should I fix this on emacs-29 or master? Sorry for the delay, I was having some distractions lately ;-)
> 
> No need to apologize.  We all have our lives, with their "disasters".
> 
> If the fix is relatively simple and safe, I'd prefer this to be fixed
> on emacs-29.  But if not, we can fix it later; after all, on emacs-29
> this is a relatively rare issue, since we don't use tree-sitter for
> movement by defuns there.
> 
> Thanks.

I pushed a fix for it to emacs-29.

Yuan