On Wed, Apr 24, 2024 at 06:39:33PM -0400, Jason Merrill wrote:
> > --- gcc/cp/decl2.cc.jj 2024-04-23 14:49:41.933186265 +0200
> > +++ gcc/cp/decl2.cc 2024-04-24 15:17:09.043625729 +0200
> > @@ -3314,7 +3314,16 @@ tentative_decl_linkage (tree decl)
> > to mark the functions at this point. */
> > if (DECL_DECLARED_INLINE_P (decl)
> > && (!DECL_IMPLICIT_INSTANTIATION (decl)
> > - || DECL_DEFAULTED_FN (decl)))
> > + || DECL_DEFAULTED_FN (decl)
> > + /* For implicit instantiations of cdtors,
> > + if import_export_decl would use comdat linkage,
> > + make sure to use it right away, so that maybe_clone_body
> > + can use aliases. See PR113208. */
> > + || (DECL_MAYBE_IN_CHARGE_CDTOR_P (decl)
> > + && (flag_implicit_templates
> > + || flag_implicit_inline_templates)
> > + && flag_weak
> > + && TARGET_SUPPORTS_ALIASES)))
>
> It seems wrong to set DECL_INTERFACE_KNOWN for cdtors that might get an
> explicit instantiation later, and likewise for comdat_linkage when
> !flag_weak; instead of adding this condition to the if, how about adding an
> else like
>
> > else if (DECL_MAYBE_IN_CHARGE_CDTOR_P (decl))
> > /* For implicit instantiations of cdtors,
> > if import_export_decl would use comdat linkage,
> > make sure to use it right away, so that maybe_clone_body
> > can use aliases. See PR113208. */
> > maybe_make_one_only (decl);
>
> ?
Then can_alias_cdtor would return false, because it ends with:
/* Don't use aliases for weak/linkonce definitions unless we can put both
symbols in the same COMDAT group. */
return (DECL_INTERFACE_KNOWN (fn)
&& (SUPPORTS_ONE_ONLY || !DECL_WEAK (fn))
&& (!DECL_ONE_ONLY (fn)
|| (HAVE_COMDAT_GROUP && DECL_WEAK (fn))));
Should we change that DECL_INTERFACE_KNOWN (fn) in there to
(DECL_INTERFACE_KNOWN (fn) || something) then and what that
something should be? HAVE_COMDAT_GROUP && DECL_ONE_ONLY (fn)?
Jakub
