Re: heads up RE autoconf C23 vs legacy code

[Greg Troxel <gdt%lexort.com@localhost>]

Tobias Nygren <tnn%NetBSD.org@localhost> writes:

> The recent autoconf upgrade broke devel/scmcvs. It is now injecting
> -std=gnu23 on the command line after having regenerated the configure
> script. Apparently this is by design since autoconf 2.73 but it's not
> mentioned anywhere in the commit message.
>
> There are legacy prototypes in scmcvs that don't compile with C23.
> FORCE_C_STD=gnu99 seems to undo autoconf's assumptions so I guess
> that's the fix we should use? Probably there are other packages that
> are broken. I found macports PRs related to PHP 8.2, 8.3, 8.4 ...

I have committed the diff to use autoconf269, which solves the immediate
problem and does not preclude harder solutions.  I don't mean to have
concluded the discussion - just that I don't see a reason to leave it
broken.

My impression is that my suggestion to make --std=c23 cause a compiler
error (in wrappers) if c23 is not in USE_CC_FEATURES has received
favorable comments and no objections.  I will see if that's reasonable
to code and try it locally.