On Thu, Sep 26, 2024 at 05:27:23PM -0400, Jason Merrill wrote:
> On 9/26/24 1:29 AM, Nathaniel Shead wrote:
> > On Tue, Sep 24, 2024 at 09:47:17AM +1000, Nathaniel Shead wrote:
> > > Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk?
> > >
> > > -- >8 --
> > >
> > > [module.import] p6 says "A header unit shall not contain a definition of
> > > a non-inline function or variable whose name has external linkage."
> > >
> > > This patch implements this requirement, and cleans up some issues in the
> > > testsuite where this was already violated. To handle deduction guides
> > > we mark them as inline, since although we give them a definition for
> > > implementation by the standard they have no definition, and so should
> > > not error in this case.
> > >
> > > One remaining question is the behaviour of code like:
> > >
> > > struct S { static const int x = 123; };
> > >
> > > 'S::x' is not 'inline' here, but this is legal code as long as there is
> > > exactly one definition elsewhere if 'x' is ever odr-used, as specified
> > > by [class.static.data] p4. However, since it's not 'inline' then the
> > > exemption for [module.import] does not apply, and so it appears uses of
> > > this in header units should error.
>
> But that isn't a definition, only a declaration. So it's well-formed in a
> header unit.
>
> https://eel.is/c++draft/class.static#data-3
>
> Jason
>
Ah right, thanks, completely missed that. I'll update this in the next
version of this patch series I'll be sending out shortly.
Nathaniel
