From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by sourceware.org (Postfix) with ESMTP id 05976385E01F for ; Mon, 6 Apr 2020 16:36:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 05976385E01F Received: from mail-io1-f72.google.com (mail-io1-f72.google.com [209.85.166.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-426-9VxgHbbjNhOUbl5thRSiBQ-1; Mon, 06 Apr 2020 12:36:14 -0400 X-MC-Unique: 9VxgHbbjNhOUbl5thRSiBQ-1 Received: by mail-io1-f72.google.com with SMTP id a16so298808ios.9 for ; Mon, 06 Apr 2020 09:36:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ErojW4w4S0RDG5O8zfqdWQkoUC12oZIt+B+lxohM+uk=; b=sK/Uz9Qa631pITv7rvSx6fJ2r5u2bjBDhsRZQt1s7bVW61Eu5H/cYGNbKKJZidUUio cIbEF5jb72PWxe3NlN6w1QePt1ul44SN1In9cmScSiUEHsHA9BasdrbAObHplNrezhX4 //X/hG7jTXqyAI+U2leTVV0pJ55Z96YibtHWsOQ4uGQvlmlMEJ3WWAfKCBv5nTsf45s2 uZyI6wDiNYa+y5zZrZstsv6/H8NhyBkLEnMuiQdofi1mENgvIJx39hYYkRhlTY5s4/iQ J0sCM3WgTuwDjhqTjbaOWaGqrB/GrCnCQVmnR6geukcaa+4ftJd2ysB68BbVfiMlmgGo dXWg== X-Gm-Message-State: AGi0PuayGsnjnQA62i6aTBE3Ws2o/zOfMLUyYgc/jRrrHxXYr+5hngQb SzPJfceITeWJfYzdC6xLkXa6qttOylKy9d+cQ4XUFOi2bUZZNFLiXsRSpuUma16Pg/HSlojF6TR xGRQWJ2SdNcMQPStKNnzwPTsP+oLLpxiVwg== X-Received: by 2002:a92:4858:: with SMTP id v85mr173352ila.100.1586190974044; Mon, 06 Apr 2020 09:36:14 -0700 (PDT) X-Google-Smtp-Source: APiQypKzLREI0WjykBQWQARgNIM/PPuFGROkShEC59Tg9Kho50OEZpLb2hozdMu8d/4XMZ/ZKbopJAk5riWlRevR3p4= X-Received: by 2002:a92:4858:: with SMTP id v85mr173322ila.100.1586190973740; Mon, 06 Apr 2020 09:36:13 -0700 (PDT) MIME-Version: 1.0 References: <20200330202823.428754-1-polacek@redhat.com> <20200404010813.GV2929@redhat.com> <79f201f2-3932-b10c-7f78-afda837c93e4@redhat.com> <20200404175638.GA633012@redhat.com> <6d6371fa-429a-e061-337c-16235e1a94af@redhat.com> <20200406155715.GC633012@redhat.com> In-Reply-To: <20200406155715.GC633012@redhat.com> From: Jason Merrill Date: Mon, 6 Apr 2020 12:35:59 -0400 Message-ID: Subject: Re: [PATCH v3] c++: Fix crash in gimplifier with paren init of aggregates [PR94155] To: Marek Polacek Cc: GCC Patches X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-24.0 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, HTML_MESSAGE, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Apr 2020 16:36:20 -0000 Ok. On Mon, Apr 6, 2020, 11:57 AM Marek Polacek 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 o= f > 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 =3D 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 **cleanups) > > > > > init =3D build_constructor_from_list > (init_list_type_node, init); > > > > > CONSTRUCTOR_IS_DIRECT_INIT (init) =3D true; > > > > > CONSTRUCTOR_IS_PAREN_INIT (init) =3D 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 nothin= g > when it gets > > > > > + CONSTRUCTOR_IS_PAREN_INIT. */ > > > > > + init =3D digest_init (type, init, tf_warning_or_err= or); > > > > > > > > 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 |=3D 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 CONSTRUCTO= R > > 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 =3D true; > > if (try_const) > > { > > + if (!field) > > + field =3D size_int (idx); > > tree e =3D 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 =3D true; > if (try_const) > { > + if (!field) > + field =3D size_int (idx); > tree e =3D 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 =E2=80=A2 Red Hat, Inc. =E2=80=A2 300 A St, Boston, MA > >