Ok.
On Mon, Apr 6, 2020, 11:57 AM Marek Polacek <pola...@redhat.com> wrote:
> On Mon, Apr 06, 2020 at 10:47:49AM -0400, Jason Merrill via Gcc-patches
> wrote:
> > On 4/4/20 1:56 PM, Marek Polacek wrote:
> > > On Fri, Apr 03, 2020 at 10:39:49PM -0400, Jason Merrill via
> Gcc-patches wrote:
> > > > On 4/3/20 9:08 PM, Marek Polacek wrote:
> > > > > On Fri, Apr 03, 2020 at 03:01:37PM -0400, Jason Merrill via
> Gcc-patches wrote:
> > > > > > On 3/30/20 4:28 PM, Marek Polacek wrote:
> > > > > > > Here we crash in the gimplifier because
> gimplify_init_ctor_eval doesn't
> > > > > > > expect null indexes for a constructor:
> > > > > > >
> > > > > > > /* ??? Here's to hoping the front end fills in all of
> the indices,
> > > > > > > so we don't have to figure out what's missing
> ourselves. */
> > > > > > > gcc_assert (purpose);
> > > > > > >
> > > > > > > The indexes weren't filled because we never called
> reshape_init: for
> > > > > > > a constructor that represents parenthesized initialization of
> an
> > > > > > > aggregate we don't allow brace elision or designated
> initializers. So
> > > > > > > fill in the indexes manually, here we have an array, and we
> can simply
> > > > > > > assign indexes starting from 0.
> > > > > > >
> > > > > > > Bootstrapped/regtested on x86_64-linux, ok for trunk?
> > > > > >
> > > > > > Shouldn't digest_init fill in the indexes? In
> > > > > > process_init_constructor_array I see
> > > > > >
> > > > > > if (!ce->index)
> > > > > > ce->index = size_int (i);
> > > > >
> > > > > Yes, that works too. Thus:
> > > > >
> > > > > Bootstrapped/regtested on x86_64-linux, ok for trunk?
> > > > >
> > > > > -- >8 --
> > > > > Here we crash in the gimplifier because gimplify_init_ctor_eval
> doesn't
> > > > > expect null indexes for a constructor:
> > > > >
> > > > > /* ??? Here's to hoping the front end fills in all of the
> indices,
> > > > > so we don't have to figure out what's missing
> ourselves. */
> > > > > gcc_assert (purpose);
> > > > >
> > > > > The indexes weren't filled because we never called reshape_init:
> for
> > > > > a constructor that represents parenthesized initialization of an
> > > > > aggregate we don't allow brace elision or designated
> initializers. So
> > > > > call digest_init to fill in the indexes.
> > > > >
> > > > > Bootstrapped/regtested on x86_64-linux, ok for trunk?
> > > > >
> > > > > PR c++/94155 - crash in gimplifier with paren init of
> aggregates.
> > > > > * decl.c (check_initializer): Call digest_init.
> > > > >
> > > > > * g++.dg/cpp2a/paren-init22.C: New test.
> > > > > ---
> > > > > gcc/cp/decl.c | 5 +++++
> > > > > gcc/testsuite/g++.dg/cpp2a/paren-init22.C | 15 +++++++++++++++
> > > > > 2 files changed, 20 insertions(+)
> > > > > create mode 100644 gcc/testsuite/g++.dg/cpp2a/paren-init22.C
> > > > >
> > > > > diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
> > > > > index 69a238997b4..63e7bda09f5 100644
> > > > > --- a/gcc/cp/decl.c
> > > > > +++ b/gcc/cp/decl.c
> > > > > @@ -6754,6 +6754,11 @@ check_initializer (tree decl, tree init,
> int flags, vec<tree, va_gc> **cleanups)
> > > > > init = build_constructor_from_list
> (init_list_type_node, init);
> > > > > CONSTRUCTOR_IS_DIRECT_INIT (init) = true;
> > > > > CONSTRUCTOR_IS_PAREN_INIT (init) = true;
> > > > > + /* The gimplifier expects that the front end fills
> in all of the
> > > > > + indices. Normally, reshape_init_array fills
> these in, but we
> > > > > + don't call reshape_init because that does nothing
> when it gets
> > > > > + CONSTRUCTOR_IS_PAREN_INIT. */
> > > > > + init = digest_init (type, init, tf_warning_or_error);
> > > >
> > > > But why weren't we already calling digest_init in store_init_value?
> Was the
> > > > CONSTRUCTOR making it all the way to gimplification still having
> > > > init_list_type_node?
> > >
> > > It's because we set LOOKUP_ALREADY_DIGESTED a few lines below:
> > > 6813 /* Don't call digest_init; it's unnecessary and
> will complain
> > > 6814 about aggregate initialization of
> non-aggregate classes. */
> > > 6815 flags |= LOOKUP_ALREADY_DIGESTED;
> > > and so store_init_value doesn't digest. Given the comment I'd be
> nervous about
> > > not setting that flag here.
> >
> > OK, then why isn't it called by build_aggr_init? How is the CONSTRUCTOR
> > getting a type without this being fixed up?
> >
> > ...
> >
> > Ah, because build_vec_init builds up a new CONSTRUCTOR and gives it a
> type
> > without setting the indexes like process_init_constructor_array does:
> >
> > Jason
>
> > diff --git a/gcc/cp/init.c b/gcc/cp/init.c
> > index 27623cf4db1..ea95a3bc910 100644
> > --- a/gcc/cp/init.c
> > +++ b/gcc/cp/init.c
> > @@ -4438,6 +4438,8 @@ build_vec_init (tree base, tree maxindex, tree
> init,
> > errors = true;
> > if (try_const)
> > {
> > + if (!field)
> > + field = size_int (idx);
> > tree e = maybe_constant_init (one_init);
> > if (reduced_constant_expression_p (e))
> > {
>
> That works, thanks for figuring that out.
>
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>
> -- >8 --
> Here we crash in the gimplifier because gimplify_init_ctor_eval doesn't
> expect null indexes for a constructor:
>
> /* ??? Here's to hoping the front end fills in all of the indices,
> so we don't have to figure out what's missing ourselves. */
> gcc_assert (purpose);
>
> The indexes weren't filled because we never called reshape_init: for
> a constructor that represents parenthesized initialization of an
> aggregate we don't allow brace elision or designated initializers.
>
> PR c++/94155 - crash in gimplifier with paren init of aggregates.
> * init.c (build_vec_init): Fill in indexes.
>
> * g++.dg/cpp2a/paren-init22.C: New test.
> ---
> gcc/cp/init.c | 2 ++
> gcc/testsuite/g++.dg/cpp2a/paren-init22.C | 15 +++++++++++++++
> 2 files changed, 17 insertions(+)
> create mode 100644 gcc/testsuite/g++.dg/cpp2a/paren-init22.C
>
> diff --git a/gcc/cp/init.c b/gcc/cp/init.c
> index 27623cf4db1..ea95a3bc910 100644
> --- a/gcc/cp/init.c
> +++ b/gcc/cp/init.c
> @@ -4438,6 +4438,8 @@ build_vec_init (tree base, tree maxindex, tree init,
> errors = true;
> if (try_const)
> {
> + if (!field)
> + field = size_int (idx);
> tree e = maybe_constant_init (one_init);
> if (reduced_constant_expression_p (e))
> {
> diff --git a/gcc/testsuite/g++.dg/cpp2a/paren-init22.C
> b/gcc/testsuite/g++.dg/cpp2a/paren-init22.C
> new file mode 100644
> index 00000000000..1b2959e7731
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/paren-init22.C
> @@ -0,0 +1,15 @@
> +// PR c++/94155 - crash in gimplifier with paren init of aggregates.
> +// { dg-do compile { target c++2a } }
> +
> +struct S { int i, j; };
> +
> +struct A {
> + S s;
> + constexpr A(S e) : s(e) {}
> +};
> +
> +void
> +f()
> +{
> + A g[1]({{1, 1}});
> +}
>
> base-commit: c72a1b6f8b26de37d1a922a8af143af009747498
> --
> Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA
>
>
