On Wed, Jul 19, 2023 at 02:32:15PM -0400, Patrick Palka wrote:
> On Wed, 19 Jul 2023, Marek Polacek wrote:
>
> > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>
> LGTM. It might be preferable to check COMPLETE_TYPE_P in the caller
> instead, so that we avoid inspecting CLASSTYPE_NON_AGGREGATE on an
> incomplete class type, and so that the caller doesn't "commit" to
> building an aggregate conversion.
Perhaps. I wanted to avoid the call to build_user_type_conversion_1.
I could add an early return to implicit_conversion_1 but I'd have to
move some code around not to check COMPLETE_TYPE_P before complete_type.
> >
> > -- >8 --
> >
> > r13-1227 added an assert checking that the index in a CONSTRUCTOR
> > is a FIELD_DECL. That's a reasonable assumption but in this case
> > we never called reshape_init due to the type being incomplete, and
> > so the index remained an identifier node: get_class_binding never
> > got around to looking up the FIELD_DECL.
> >
> > We can avoid the crash by returning early in build_aggr_conv; we'd
> > return NULL anyway due to:
> >
> > if (i < CONSTRUCTOR_NELTS (ctor))
> > return NULL;
> >
> > PR c++/110114
> >
> > gcc/cp/ChangeLog:
> >
> > * call.cc (build_aggr_conv): Return early if the type isn't
> > complete.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/cpp2a/desig28.C: New test.
> > * g++.dg/cpp2a/desig29.C: New test.
> > ---
> > gcc/cp/call.cc | 5 +++++
> > gcc/testsuite/g++.dg/cpp2a/desig28.C | 17 +++++++++++++++++
> > gcc/testsuite/g++.dg/cpp2a/desig29.C | 10 ++++++++++
> > 3 files changed, 32 insertions(+)
> > create mode 100644 gcc/testsuite/g++.dg/cpp2a/desig28.C
> > create mode 100644 gcc/testsuite/g++.dg/cpp2a/desig29.C
> >
> > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
> > index b55230d98aa..0af20a81717 100644
> > --- a/gcc/cp/call.cc
> > +++ b/gcc/cp/call.cc
> > @@ -986,6 +986,11 @@ build_aggr_conv (tree type, tree ctor, int flags,
> > tsubst_flags_t complain)
> > tree empty_ctor = NULL_TREE;
> > hash_set<tree, true> pset;
> >
> > + /* We've called complete_type on TYPE before calling this function, but
> > + perhaps it wasn't successful. */
> > + if (!COMPLETE_TYPE_P (type))
> > + return nullptr;
> > +
> > /* We already called reshape_init in implicit_conversion, but it might
> > not
> > have done anything in the case of parenthesized aggr init. */
> >
> > diff --git a/gcc/testsuite/g++.dg/cpp2a/desig28.C
> > b/gcc/testsuite/g++.dg/cpp2a/desig28.C
> > new file mode 100644
> > index 00000000000..b63265fea51
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/cpp2a/desig28.C
> > @@ -0,0 +1,17 @@
> > +// PR c++/110114
> > +// { dg-do compile { target c++20 } }
> > +
> > +struct A {
> > + int a,b;
> > +};
> > +
> > +struct B;
> > +
> > +void foo(const A &) {}
> > +void foo(const B &) {}
> > +
> > +int
> > +main ()
> > +{
> > + foo({.a=0});
> > +}
> > diff --git a/gcc/testsuite/g++.dg/cpp2a/desig29.C
> > b/gcc/testsuite/g++.dg/cpp2a/desig29.C
> > new file mode 100644
> > index 00000000000..bd1a82b041d
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/cpp2a/desig29.C
> > @@ -0,0 +1,10 @@
> > +// PR c++/110114
> > +// { dg-do compile { target c++20 } }
> > +
> > +struct B;
> > +
> > +void foo(const B &) {}
> > +
> > +int main() {
> > + foo({.a=0}); // { dg-error "invalid" }
> > +}
> >
> > base-commit: 2971ff7b1d564ac04b537d907c70e6093af70832
> > --
> > 2.41.0
> >
> >
>
Marek
