Re: master 37889523278: Add new `swap` macro and use it

[Gregory Heytings <gregory@heytings.org>]

>
> The errors in lisp.h are caused by your building Emacs with 4-byte 
> longs, hence "CPU".
>

This is almost becoming funny.  You did not even look at the file I 
attached to my previous post.  Of course, why would you do so, with a 
guiding principle that everyone is wrong?

Looking at that file would have saved yourself from throwing more nonsense 
in this discussion.  You would have seen that the error has nothing to do 
with 4-byte longs.  The error is that Sun C 5.8 does not recognize the 
"alignas" keyword, which is a C11 construct that was introduced 
unconditionally in Emacs by e32a579975 in July 2012.  It was made 
conditional only ten years later, by 1e2bc1bbf4 in December 2021 (to 
support builds with older version of TCC).

Given that there has been a grand total of zero bug reports from Sun C 5.8 
users about this, we can safely conclude that nobody compiled Emacs with 
Sun C 5.8 between July 2012 and December 2021, that is, Emacs 25 up to and 
including 28.

Both "alignas" and "typeof" are supported by Sun 5.9, released two years 
after Sun C 5.8, in 2007.

>
> cc: Sun C 5.8 2005/10/13
>
> that is 4 years out of date.  Install:
>
> cc: Sun C 5.8 Patch 121015-07 2009/04/22
>

These patches were released two years after Sun C 5.9, which was freely 
downloadable, at no charge.  IOW, in 2009, an up to date Solaris system 
would have provided Sun C 5.9 for already two years, or even Sun C 5.10, 
which was released that year.  In 2024, an up to date Solaris 10 system 
provides Sun C 5.11 or above.

Your claim has now narrowed down to the following: Sun C 5.8, but only 
with some patches, and only on 64-bit platforms, can produce a working 
Emacs 29 build.

I will not waste more of my time to check that claim in detail, but FTR I 
seriously doubt it is: my attempt at building Emacs 29 failed with 
'"alloc.c", line 692: type of struct member "__b" can not be derived from 
structure with flexible array member', for which the remedy is, according 
to a Google search, "upgrade your tools to Oracle Solaris Studio 
(previously Sun Studio) 12 [that is, Sun C 5.9] or something newer".

But, even assuming that your claim is true, given that no-one compiled 
Emacs 25-28 with Sun C 5.8 in more than ten years, no-one suddenly needs 
to compile Emacs 29 with that compiler in 2024.  Claiming the opposite is 
beyond absurd.

>
> The GCC build farm, Paul Eggert, and several other Emacs and Gnulib 
> developers have and routinely test on up-to-date Solaris 10 systems with 
> various versions of Sun Studio.  For example,
>
> https://lists.gnu.org/archive/html/bug-gnulib/2023-10/msg00021.html
>

That link is irrelevant: it's about Gnulib, which is a different project 
with different constraints and different goals.