From patchwork Wed Mar 22 23:27:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Wakely X-Patchwork-Id: 66776 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 7FD7E385B506 for ; Wed, 22 Mar 2023 23:27:42 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7FD7E385B506 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1679527662; bh=qbnIjj8jn98mQhnyfEYLBwhVs3r/j5PixMV/9VzB+f8=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=spmK9/elhVzzZ/EP7E0QRsVSccIQM69sLVMKBZYN2ckl+tl99wmmXc/yLW2FRMqXY AWSYvUcSZo9J4g3RPD9GEWdPxciT/baAFk+mod4L6Psvnm39Zsqyxn2HGlAtVq+6WX jxQCoURrDFOF6CoSQUKM7OeGiJuShp5xTn7+anwE= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org 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 AA6BC3858436 for ; Wed, 22 Mar 2023 23:27:13 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org AA6BC3858436 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-240-37dXYQryOGSvYxyNvfO5bQ-1; Wed, 22 Mar 2023 19:27:11 -0400 X-MC-Unique: 37dXYQryOGSvYxyNvfO5bQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 820471C02C9B; Wed, 22 Mar 2023 23:27:11 +0000 (UTC) Received: from localhost (unknown [10.33.36.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id 491A1202701E; Wed, 22 Mar 2023 23:27:10 +0000 (UTC) To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Fix assigning nullptr to std::atomic> (LWG 3893) Date: Wed, 22 Mar 2023 23:27:09 +0000 Message-Id: <20230322232709.457972-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.1 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP 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-Patchwork-Original-From: Jonathan Wakely via Gcc-patches From: Jonathan Wakely Reply-To: Jonathan Wakely Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Tested powerpc64le-linux. Pushed to trunk. -- >8 -- LWG voted this to Tentatively Ready recently. libstdc++-v3/ChangeLog: * include/bits/shared_ptr_atomic.h (atomic::operator=(nullptr_t)): Add overload, as per LWG 3893. * testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc: Check assignment from nullptr. --- libstdc++-v3/include/bits/shared_ptr_atomic.h | 6 ++++++ .../20_util/shared_ptr/atomic/atomic_shared_ptr.cc | 9 +++++++++ 2 files changed, 15 insertions(+) diff --git a/libstdc++-v3/include/bits/shared_ptr_atomic.h b/libstdc++-v3/include/bits/shared_ptr_atomic.h index d142616f485..2295b48e732 100644 --- a/libstdc++-v3/include/bits/shared_ptr_atomic.h +++ b/libstdc++-v3/include/bits/shared_ptr_atomic.h @@ -650,6 +650,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION operator=(shared_ptr<_Tp> __desired) noexcept { _M_impl.swap(__desired, memory_order_seq_cst); } + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3893. LWG 3661 broke atomic> a; a = nullptr; + void + operator=(nullptr_t) noexcept + { store(nullptr); } + shared_ptr<_Tp> exchange(shared_ptr<_Tp> __desired, memory_order __o = memory_order_seq_cst) noexcept diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc index a1902745a3e..54cf2621ea1 100644 --- a/libstdc++-v3/testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc +++ b/libstdc++-v3/testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc @@ -145,6 +145,14 @@ test_counting() VERIFY( counter == 2 ); } +void +test_lwg3893() +{ + // LWG 3893. LWG 3661 broke atomic> a; a = nullptr; + std::atomic> a; + a = nullptr; +} + int main() { @@ -152,4 +160,5 @@ main() test_atomic_shared_ptr(); test_wait_notify(); test_counting(); + test_lwg3893(); }