Re: [PATCH] Change module interface to no longer use GMP objects directly.

[Paul Eggert]

On 11/23/19 12:08 PM, Philipp Stephani wrote:

> stdio.h is part of the C implementation, but emacs-module.h is not.

> > > And developers do not expect /usr/include/stdio.h to be the same
> > > on all platforms; why would they expect /usr/include/emacs-module.h to
> > > be the same?
>
> Because stdio.h is part of the C implementation, but emacs-module.h is not.

What difference does that make to the module developer? emacs-module.h includes 
<stdint.h> and other files that are implementation-dependent. Because of this, 
from the developer's point of view "#include <emacs-module.h>" is just as 
implementation-dependent as "#include <stdio.h>" is, which means developers must 
be cognizant of platform dependencies anyway.

So I still don't why it's crucial that emacs-module.h is byte-for-byte identical 
on all platforms.

> - Documenting the restriction on the number of magnitude array elements.
> - Using a typedef emacs_limb_t for the magnitude array elements, with
> the guarantee that's is a stable unsigned integer type. I will make
> emacs_limb_t an alias of unsigned long long if ULONG_MAX <=
> 0xFFFFFFFF, and an alias of unsigned long otherwise.

Thanks, that'll be an improvement.