On 4/18/22 18:24, Keith David Bershatsky wrote:
>    CC       nsterm.o
> In file included from nsterm.m:46:
> lisp.h:2156: warning: declaration does not declare anything
>    CC       nsfns.o
> In file included from nsfns.m:36:
> lisp.h:2156: warning: declaration does not declare anything
> nsfns.m:1099: warning: braces around scalar initializer

These come from Emacs 28's use of an anonymous union, a feature that is 
in C11 but not C99. The feature is used only in one place and it is easy 
to avoid using it, so I installed a patch to master to do that (see 
attached).

I noticed another place where Emacs used a feature not supported by C99, 
namely an enum out of int range, and installed a patch to master to fix 
that too (also attached).

Although I've been admonished to not install into emacs-28, I think you 
can use these patches there. They should work though you may need to 
move their line numbers a bit.