On Mon, Feb 28, 2022 at 12:13:36PM -0400, Jason Merrill wrote:
> On 2/25/22 17:59, Marek Polacek wrote:
> > [ Most likely a GCC 13 patch, but I'm posting it now so that I don't lose
> > it. ]
> >
> > When looking into the other PR I noticed that we fail to give a warning
> > for a deprecated enumerator when the enum is in a class template. This
> > only happens when the attribute doesn't have an argument. The reason is
> > that when we tsubst_enum, we create a new enumerator:
> >
> > build_enumerator (DECL_NAME (decl), value, newtag,
> > DECL_ATTRIBUTES (decl), DECL_SOURCE_LOCATION (decl));
> >
> > but DECL_ATTRIBUTES (decl) is null when the attribute was provided
> > without an argument -- in that case it simply melts into a tree flag.
> > handle_deprecated_attribute has:
> >
> > if (!args)
> > *no_add_attrs = true;
> >
> > so the attribute isn't retained and we lose it when tsubsting. Same
> > thing when the attribute is on the enum itself.
> >
> > Attribute unavailable is a similar case, but it's different in that
> > it can be a late attribute whereas "deprecated" can't:
>
> Iain, was this difference intentional?
FWIW, I'm in favor of treating deprecated/unavailable the same, that is,
adding unavailable...
> > is_late_template_attribute has
> >
> > /* But some attributes specifically apply to templates. */
> > && !is_attribute_p ("abi_tag", name)
> > && !is_attribute_p ("deprecated", name)
...here. But that really does seem like a GCC 13 change.
> > && !is_attribute_p ("visibility", name))
> > return true;
> > else
> > return false;
> >
> > which looks strange, but attr-unavailable-9.C tests that we don't error when
> > the attribute is applied on a template.
> >
> > Bootstrapped/regtested on x86_64-pc-linux-gnu.
>
> This looks extremely safe, so let's go ahead and apply it to trunk.
Will do, thanks.
Marek
