Re: Emacs macOS build warnings

[Alan Third]

On Wed, Feb 02, 2022 at 12:46:09PM +0100, Mattias Engdegård wrote:
> Dear Emacs NS maintainers,
> 
> Building Emacs on macOS 11.6.3 (Big Sur) with Apple clang 13.0.0, I
> get deprecation warnings from two uses of `vfork` and one of
> `CTGetCoreTextVersion`. I'd like to get rid of them but without
> causing trouble for other configurations.
> 
> Silencing the vfork warnings would be straightforward enough but the
> question is under what condition it should be done. Maybe it doesn't
> make any harm when it isn't needed?

On the latest macOS I believe vfork now does the same thing as fork,
so it might be easiest to detect the OS version and unset HAVE_VFORK,
although since we don't seem to actually check for that directly in
configure.ac I guess it's perhaps a standard test in autoconfig which
may make it hard to over-ride?

The alternative approach is to look at whether we should be using
posix_spawn here. I was under the impression that we had already
switched to using posix_spawn, at least on macOS, so I guess these
calls to vfork were missed.

> I treated CTGetCoreTextVersion warning by following the direction in
> the deprecation message and used NSProcesInfo instead, and it seems
> to work although it's a bit clumsy. Is there a better way?

I think your fix for this is good and probably the right thing to do.

-- 
Alan Third