bug#69952: [PATCH] Support pdumping compiled queries by dumping their source

[Yuan Fu <casouri@gmail.com>]

> On Apr 20, 2024, at 2:32 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Yuan Fu <casouri@gmail.com>
>> Date: Sat, 20 Apr 2024 01:08:15 -0700
>> Cc: dancol@dancol.org,
>> serg.foo@gmail.com,
>> 69952@debbugs.gnu.org
>> 
>> 
>> 
>>> On Apr 13, 2024, at 12:41 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>>>> 
>>>> And I have a question: what happens if the pdumper file dumped with
>>>> tree-sitter available is loaded by an Emacs session in which
>>>> tree-sitter is not available?  That can happen on Windows, for
>>>> example, if the tree-sitter library or the grammar library required
>>>> for recomputing the query is not available.  I think we need some code
>>>> to prevent Emacs from crashing on startup in that case.
>> 
>> Yeah, being able to dump queries is certainly nice. There will be problems if the Emacs session that later loads the query either have a different grammar version loaded, or a difference grammar library for the same language, or outright doesn’t have tree-sitter like Eli mentioned. I don’t know if they are big enough problems to give up dumping queries, though.
> 
> Giving up: no.  But I think the code which loads the queries from the
> pdumper file should be protected from crashing in those cases.  Can
> you suggest how to do that?

Would Emacs crash? If the dump file just contains the query (which is a string), then Emacs would just compile the query with treesit-query-compile, it could fail (due to the reasons I mentioned), but shouldn’t crash Emacs.

Yuan