On Sun, Jan 22, 2023 at 03:40:26PM -0500, Jason Merrill wrote:
> > 2023-01-21 Jakub Jelinek <ja...@redhat.com>
> >
> > PR c++/108474
> > * cp-gimplify.cc (cp_fold_r): Handle structured bindings
> > vars like anon union artificial vars.
> >
> > * g++.dg/cpp1z/decomp57.C: New test.
> > * g++.dg/cpp1z/decomp58.C: New test.
> >
> > --- gcc/cp/cp-gimplify.cc.jj 2023-01-19 23:27:27.998400866 +0100
> > +++ gcc/cp/cp-gimplify.cc 2023-01-20 11:00:06.093446737 +0100
> > @@ -1012,8 +1012,12 @@ cp_fold_r (tree *stmt_p, int *walk_subtr
> > case VAR_DECL:
> > /* In initializers replace anon union artificial VAR_DECLs
> > - with their DECL_VALUE_EXPRs, as nothing will do it later. */
> > - if (DECL_ANON_UNION_VAR_P (stmt) && !data->genericize)
> > + with their DECL_VALUE_EXPRs, as nothing will do it later.
> > + Ditto for structured bindings. */
> > + if (!data->genericize
> > + && DECL_HAS_VALUE_EXPR_P (stmt)
> > + && (DECL_ANON_UNION_VAR_P (stmt)
> > + || (DECL_DECOMPOSITION_P (stmt) && DECL_DECOMP_BASE (stmt))))
>
> Is there a reason not to do this for all cases of DECL_HAS_VALUE_EXPR_P,
> without the extra checks?
I was just trying to be careful, because unfortunately this spot
doesn't mean it really is only expanded in static var DECL_INITIAL,
it can make it into dynamic initializers, and most of DECL_VALUE_EXPRs
appear only in runtime code, otherwise we'd have much more of these issues.
But if you think it is ok, I'll test tonight a version just with
if (!data->genericize && DECL_HAS_VALUE_EXPR_P (stmt)
Jakub
