C11/POSIX-2024 Questions

[brian.inglis@systematicsw.ab.ca]

On 2024-06-28 08:37, Joel Sherrill wrote:
> Hi
> 
> I am finishing up reviewing the additions from POSIX Issue 8 which was released 
> recently. I noticed a few things and have questions on the right approach.
> 
> + I only have the final draft for POSIX-2024. It says "_POSIX_VERSION to the value
> 20yymmL." It isn't on the web yet for the HTML version. Anyone know the value 
> this has in the final version?

The Austin Group minutes say in:

	https://www.mail-archive.com/austin-group-l@opengroup.org/msg12711.html

"The IEEE and The Open Group pdf edition was published on Friday June 14th."

so I would expect POSIX-1.2004/IEEE Std. 1003-1(2024) to have 202406L date.

Another email states it could take another month for the HTML ~July 21.

> + sys/features.h appears to need this new POSIX version added at least to the 
> comment block. I don't think it necessarily changes any logic below that.

The latest draft normative references include ISO/IEC 10646:2020 (6th edition) 
so Unicode should be at least 13 dated 2020-03-06 and __STDC_ISO_10646__ at 
least 202003L.
This was amended by ISO/IEC 10646:2020/Amd1:2023 2023-07-17 so Unicode could be 
up to 15.0 dated 2022-09-09 with __STDC_ISO_10646__ 202209L.
There were no amendments for Unicode 14 2021-09-10 or 15.1 2023-08-28.
Future considerations expect Unicode 16 in Amendment 2:2025.

ISO/IEC JTC 1/SC2 WG2 is no longer at http://std.dkuug.dk/jtc1/sc2/wg2 
(NXDOMAIN) so old working documents are no longer available but has moved to 
https://www.unicode.org/wg2/ where more recent working documents are available, 
and hopes are that ISO/IEC standards can be stabilized with normative references 
to Unicode specs like UTS Unicode Technical Standards and UAX Unicode Standard 
Annexes.

> + memmem is in string.h under the __GNU_VISIBLE guard. Does it now need to be 
> under a __POSIX_VISIBLE > 2024mmdd and __GNU_VISIBLE?
> 
> + aligned_alloc in stdlib.h is only guarded by C > 2011. Does that need to be an 
> || POSIX >= 2024 also?
> 
> + C11 and POSIX-2024 add these complex methods.
> 
> double complex CMPLX(double x, double y);
> float complex CMPLXF(float x, float y);
> long double complex CMPLXL(long double x, long double y);
> 
> FreeBSD has a macro implementation 
> (https://github.com/lattera/freebsd/blob/master/include/complex.h#L49 
> <https://github.com/lattera/freebsd/blob/master/include/complex.h#L49>). If I 
> add that to complex.h, does it also need a __ISO_C_VISIBLE >= 2011 || 
> __POSIX_VISIBLE > 2024mmdd guard?

The same minutes linked above says:

	"The ISO/IEC [POSIX] ballot closes on June 28."

Also note that ISO/IEC 9899:2024 C is targeted for July 12, and JTC 1/SC 22/WG 
14 hope to get that passed by some picky ISO editors in time, or it will be 
cancelled for this year.

So look for ISO C >= 2024 and add changes, including docs and compiler options, 
and note 202X is becoming ambiguous so groups are using 202Y.

> + Should I continue to look for guards on things that are newly added in POSIX 
> 2024 and already in newlib?
> 
> That's it so far. Just picky stuff that I plan to address given some advice.

I am also waiting to see if this will be issued as SUSv5?

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer     but when there is no more to cut
                                 -- Antoine de Saint-Exupéry