Re: Merging MPS a.k.a. scratch/igc, yet again

[Pip Cet]

Gerd Möllmann <gerd.moellmann@gmail.com> writes:

> Pip Cet via "Emacs development discussions." <emacs-devel@gnu.org>
> writes:
>
>> Does anyone remember what our conclusion was wrt
>> -fno-omit-frame-pointer?  I seem to remember there was a patch to MPS to
>> avoid relying on setjmp() to save all registers, but I'd still be
>> happier if we enabled that for all MPS builds, since we don't know
>> whether our MPS has the patch.
>
> I'm using -fno-omit-frame-pointer, but I don't remember why. I think
> Helmut said something or so (in CC).

We tried not using it, it caused a bug, I spent too many hours tracking
that one down, so now I think we should make configure.ac always enable
it, even though it should be a no-op on some architectures (I think
macOS on aarch64 is one of them).

I'm not sure what the right thing to do here is, though: do we want
force CFLAGS to include -fno-omit-frame-pointer, or set it only when
CFLAGS isn't specified explicitly, or is looking at user-provided CFLAGS
and complaining about them the right thing to do?

Pip