Re: master b99ec5d 3/3: Work around __has_attribute bug in clang 3.4

[Mattias Engdegård]

23 jan. 2021 kl. 20.42 skrev Paul Eggert <eggert@cs.ucla.edu>:

> As I understand things Apple's __nonnull keyword used to mean something else 
> but collided with GNU's __nonnull macro, so they renamed the keyword and put 
> in a backward-compatibility macro for old Applish code, but we don't need 
> that macro and can just use __nonnull for our own use.

That is fine as long as the Gnulib cdefs.h is not included in translation units 
also using Apple's framework headers, some of which do use __nonnull instead of 
_Nonnull. I suppose it's a later worry since it works for Emacs at the moment.

> I attempted to fix the problem by installing the attached patch into Gnulib, 
> and then merged Gnulib into Emacs master. Please give it a try, as I don't 
> use macOS and so did not check the patch directly.

Thank you! I can confirm that it works on macOS 10.14 (Mojave), Apple clang 
version 11.0.0 (clang-1100.0.33.17).