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 F0BF13858D28 for ; Wed, 21 Jun 2023 12:22:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org F0BF13858D28 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1687350132; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=6Njyd71sUdLURPfgXM7/Rp0zGawy9CL6Uab5OOKT0s0=; b=Vlrg6yBCX32hF9YfxP5wC4m37beQOs9zVGTvzNBkC6Svg8JHsojNhaNzjUHlm8YZwXVAsT YVwvi3flTNrTIGK8xdDCfpZMIMWCiCHoErlnlLHIrvns+mqx4TgdzVj9rcttRqniNamyZf 6cHFJJTA0xzL0wM1Ct4Xn9tOz0D6+VU= 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-518-gNVMvJaIMnW6gBBvf5g_aA-1; Wed, 21 Jun 2023 08:22:11 -0400 X-MC-Unique: gNVMvJaIMnW6gBBvf5g_aA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B470410504B1; Wed, 21 Jun 2023 12:22:08 +0000 (UTC) Received: from localhost (unknown [10.42.28.211]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8255540D1A4; Wed, 21 Jun 2023 12:22:08 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Cc: Jason Merrill Subject: [committed] [gcc-12] libstdc++: avoid bogus -Wrestrict [PR105651] Date: Wed, 21 Jun 2023 13:22:07 +0100 Message-Id: <20230621122207.302494-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,KAM_SHORT,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,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 List-Id: I've pushed Jason's patch from https://gcc.gnu.org/PR105651#c17 to the gcc-12 branch, because Jakub's fix on gcc-13 isn't possible to backport. Tested x86_64-linux, pushed to gcc-12. -- >8 -- PR tree-optimization/105651 libstdc++-v3/ChangeLog: * include/bits/basic_string.tcc (_M_replace): Add an assert to avoid -Wrestrict false positive. --- libstdc++-v3/include/bits/basic_string.tcc | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc index 0696b96604c..48fa28e6466 100644 --- a/libstdc++-v3/include/bits/basic_string.tcc +++ b/libstdc++-v3/include/bits/basic_string.tcc @@ -529,6 +529,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { const size_type __nleft = (__p + __len1) - __s; this->_S_move(__p, __s, __nleft); + // Tell the middle-end that the copy can't overlap + // (PR105651). + if (__len2 < __nleft) + __builtin_unreachable(); this->_S_copy(__p + __nleft, __p + __len2, __len2 - __nleft); } -- 2.40.1