I think it would be beneficial to have different syntax/spelling for
features still in development. That way we, as a committee, can tweak
it as we please, while mitigating effect on early adopters.
If what ends in final document is exactly the same as in early phrases,
then great, all users are left to do is simple find and replace.
Warning about using an experimental feature that is prone to changes
is obviously useful, but it disappears after upgrade to latest
standard. If there were diverges between early and final versions,
it would be nice to have warnings about that too.
~ J.Ł.
On 2024-10-07 19:35 CEST, Joseph Myers <josmy...@redhat.com> wrote:
Patches 1, 2 and 3 are logically nothing to do with this feature. I'll
wait for them to be reviewed so that we only have a single-patch series,
before doing final review of the main patch.
Since the feature was accepted as _Lengthof, that's the form that should
be added to GCC; no __lengthof__ variant needed. In general in GCC,
although not strictly required by the standard in this case, we use
pedwarn_c23 (pass OPT_Wpedantic as the option) to diagnose the use of a
new C2Y feature that's not in C23 (if -pedantic with a pre-C2Y standard,
or -Wc23-c2y-compat even in C2Y mode), with appropriate testcases to
verify this (error with -std=c23 -pedantic-errors, warning with -std=c23
-pedantic, no diagnostic with -std=c23 -pedantic-errors
-Wno-c23-c2y-compat, no diagnostic with -std=c2y -pedantic-errors, warning
with -std=c2y -pedantic-errors -Wc23-c2y-compat). (pedwarn_c23 handles
that logic, you just need the pedwarn_c23 call and the tests for those
various cases.)
