Function signatures in extern "C".

[Jonathan Wakely]

On Mon, 7 Sep 2020, 10:34 Jakub Jelinek, <jakub@redhat.com> wrote:

> On Mon, Sep 07, 2020 at 10:27:13AM +0100, Jonathan Wakely via Gcc wrote:
> > On Mon, 7 Sep 2020 at 09:18, Iain Sandoe wrote:
> > >
> > > Perhaps the PR should be reopened with “accepts invalid”?
> >
> > My impression from the PR is that the reporter was using a different
> > ABI, where the name isn't reserved. Maybe the testcase should only be
> > accepted with -fno-threadsafe-statics or -ffreestanding or something
> > to say "I'm doing things differently".
> >
> > Or we could just say that G++ reserves the Itanium ABI names
> > unconditionally, even if it doesn't need to use them, in which case it
> > would be accepts-invalid.
>
> All identifiers starting with two underscores are reserved for the
> implementation already.
>

Doh, of course. So they'd have to be using some other unsupported ABI which
uses that name for a different meaning, which seems like a badly designed
ABI given that the "__cxa_" prefix is already claimed by the Itanium ABI.

So we shouldn't ICE but any other outcome for that testcase would be ok,
including rejecting it.