Re: Rewriting make-docfile.c in Lisp?

[Eli Zaretskii <eliz@gnu.org>]

> From: Spencer Baugh <sbaugh@catern.com>
> Cc: Alan Mackenzie <acm@muc.de>, Eli Zaretskii <eliz@gnu.org>,
>  emacs-devel@gnu.org
> Date: Wed, 05 May 2021 17:11:08 -0400
> 
> Perhaps foolishly, I (experimentally) switched some existing uses of
> DEFVAR_PER_BUFFER to a new variant with a new name, and then noticed
> some test failures.  I tried to grep for "DEFVAR_PER_BUFFER" (and other
> variations) to find what might be depending on the name of the macro but
> didn't find anything, since make-docfile.c parses DEFVAR_PER_BUFFER one
> character at a time with getc and so doesn't actually include the string
> "DEFVAR_PER_BUFFER" anywhere.

We could improve discoverability of this by adding appropriate
comments to the source code there.

> Eventually I figured out that it was make-docfile that wasn't
> picking up the new name for the DEFVAR_PER_BUFFER macro.  So then I
> dug through scan_c_stream in make-docfile.c to see what would be
> required to add support for the DEFVAR_PER_BUFFER variant, but
> eventually gave up on understanding the best way to inject my new
> macro name into the manually-unrolled tree of getc-based parsing.

It's just a series of if/else if tests that examine the characters one
by one, so adding a new macro would mean some more tests like that.
Or am I missing something?