APIs in New POSIX Edition

Corinna Vinschen vinschen@redhat.com
Thu Apr 8 12:07:22 GMT 2021

On Apr  8 13:56, Corinna Vinschen wrote:
> On Apr  8 13:49, Corinna Vinschen wrote:
> > On Apr  8 06:38, Joel Sherrill wrote:
> > > What feature guard should these be behind? Will it change for the ones
> > > already in place?
> > 
> > There will be a matching POSIX.1-2021 or so, given by date/month,
> > with guards along the lines of _POSIX_C_SOURCE >= 202107L.
> > 
> > APIS we already have should keep their current guard or'ed with
> > the above _POSIX_C_SOURCE test.
> > 
> > APIs we already have but have no guard should get _DEFAULT_SOURCE
> > or'ed with the above _POSIX_C_SOURCE test.
> There are also APIs which already exist per an older POSIX version,
> but which are not guarded.  I. e., the sem_xxx functions manipulating
> POSIX semaphores.  Those don't need aguard, because they have been
> introduced in conjunction with their own header, i. e., semaphore.h.
> In these cases, the already existing ones still don't need a guard,
> just APIs added to the header will get the new _POSIX_C_SOURCE test.
> I think...


and _DEFAULT_SOURCE is probably not required at all, given it's
just current POSIX anyway.  We just have to tweka the definition
of _DEFAULT_SOURCE to include the latest POSIX.

Another one: APIs from this draft already in GlibC and newlib are
guarded with __GNU_VISIBLE in newlib (e. g. memmem).  We have to change
__GNU_VISIBLE to imply the new _POSIX_C_SOURCE setting anyway, so these
symbols can be simply guarded with the new __POSIX_VISIBLE guard.

I'm sure I still forgot some situation...


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