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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 2407F3858C2D for ; Wed, 30 Mar 2022 14:08:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 2407F3858C2D Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-3-Va7ImQFWM9i04U-dzMMf7g-1; Wed, 30 Mar 2022 10:08:26 -0400 X-MC-Unique: Va7ImQFWM9i04U-dzMMf7g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B61A238035A5 for ; Wed, 30 Mar 2022 14:08:25 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.15]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 77E07400E11D for ; Wed, 30 Mar 2022 14:08:25 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.16.1/8.16.1) with ESMTPS id 22UE8NEd172837 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT) for ; Wed, 30 Mar 2022 16:08:23 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.16.1/8.16.1/Submit) id 22UE8MJY172836 for gcc-patches@gcc.gnu.org; Wed, 30 Mar 2022 16:08:22 +0200 Date: Wed, 30 Mar 2022 16:08:22 +0200 From: Jakub Jelinek To: gcc-patches@gcc.gnu.org Subject: [committed] testsuite: Change pr80334.C testcase to dg-do compile [PR102772] Message-ID: Reply-To: Jakub Jelinek MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: Wed, 30 Mar 2022 14:08:29 -0000 Hi! The testcase has UB at runtime, placement new shouldn't construct an object with certain alignment requirements into an unaligned buffer. Discussed on IRC, tested on x86_64-linux -m32/-m64, committed to trunk. 2022-03-30 Jakub Jelinek PR tree-optimization/80334 PR target/102772 * g++.dg/torture/pr80334.C: Change from dg-do run to dg-do compile. --- gcc/testsuite/g++.dg/torture/pr80334.C.jj 2020-01-12 11:54:37.268400509 +0100 +++ gcc/testsuite/g++.dg/torture/pr80334.C 2022-03-30 15:56:54.259507802 +0200 @@ -1,4 +1,8 @@ -// { dg-do run } +// This used to be dg-do run testcase, but it is invalid at runtime: +// trying to do a placement new of A which is 16-byte sized and aligned +// into a 16-byte buffer at offset 17 bytes from 16-byte aligned address +// is UB. +// { dg-do compile } struct A { alignas(16) char c; }; struct B { A unpacked; char d; } __attribute__((packed)); Jakub