From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 43E003858297 for ; Tue, 28 Jun 2022 16:43:37 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 43E003858297 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-402-z6mntk9rNl6F9SQp6Kpxjg-1; Tue, 28 Jun 2022 12:43:34 -0400 X-MC-Unique: z6mntk9rNl6F9SQp6Kpxjg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8863F89B841; Tue, 28 Jun 2022 16:43:34 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.30]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 442E62166B29; Tue, 28 Jun 2022 16:43:34 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 25SGhV3U3981601 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 28 Jun 2022 18:43:31 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 25SGhUFr3981600; Tue, 28 Jun 2022 18:43:30 +0200 Date: Tue, 28 Jun 2022 18:43:30 +0200 From: Jakub Jelinek To: Qing Zhao Cc: gcc-patches Paul A Clarke via , kees Cook , Martin Sebor Subject: Re: [GCC 13][PATCH] PR101836: Add a new option -fstrict-flex-array[=n] and use it in __builtin_object_size Message-ID: Reply-To: Jakub Jelinek References: <45936DE9-4099-4ED2-8B2B-6956A2FB493D@oracle.com> <5281C7CE-2677-4FE3-8ED3-C5B378685DCB@oracle.com> <2DDA999B-58B1-4390-9E2E-C4D68C0FD913@oracle.com> MIME-Version: 1.0 In-Reply-To: <2DDA999B-58B1-4390-9E2E-C4D68C0FD913@oracle.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-3.8 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org 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: Tue, 28 Jun 2022 16:43:38 -0000 On Tue, Jun 28, 2022 at 03:59:22PM +0000, Qing Zhao via Gcc-patches wrote: > > On Jun 28, 2022, at 11:08 AM, Jakub Jelinek wrote: > > > > On Tue, Jun 28, 2022 at 03:03:12PM +0000, Qing Zhao wrote: > >> 2. Then replace all “array_at_struct_end_p” with using DECL_NOT_FLEXARRAY in GCC, adding new testing cases > > > > No, IMHO array_at_struct_end_p should stay as is, just test this extra flag > > too. > > Could you please explain why we still need “array_at_struct_end_p” after we have the DECL_NOT_FLEXARRAY flag in FIELD_DECL? Because the flag just tells whether some array shouldn't be treated as (poor man's) flexible array member. We still need to find out if some FIELD_DECL is to be treated like a flexible array member, which is a minority of COMPONENT_REFs. struct S { int a; char b[0]; int c; } s; struct T { int d; char e[]; }; struct U { int f; struct T g; int h; } u; Neither s.b nor u.g.e is to be treated like flexible array member, no matter what -fstrict-flex-array= option is used. Jakub