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[2620:52:3:1:0:246e:9693:128c]) by mx.google.com with ESMTPS id ef5-20020a05640228c500b0043579ad55f1si16542036edb.94.2022.07.13.11.25.05 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Jul 2022 11:25:06 -0700 (PDT) Received-SPF: pass (google.com: domain of gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org designates 2620:52:3:1:0:246e:9693:128c as permitted sender) client-ip=2620:52:3:1:0:246e:9693:128c; Authentication-Results: mx.google.com; dkim=pass header.i=@gcc.gnu.org header.s=default header.b=inJLMU1D; spf=pass (google.com: domain of gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org designates 2620:52:3:1:0:246e:9693:128c as permitted sender) smtp.mailfrom="gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gnu.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id D1F1B388552E for ; Wed, 13 Jul 2022 18:25:04 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D1F1B388552E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1657736704; bh=TWVWxEh5VWb8ywul+QwAxBbnML1uU7H8YCOfjkVOpUU=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=inJLMU1Dap0GB3b5D3nHhyjU4NG+kEdAktga4+I7pmppTniSq3geLv3l+qUYGgJlJ HBammSe3j4h3F0fowiXiIv+IbAEwY5RN9C+ITkJwHJCc673T20gsH0gbE0SHN8GXBW sNoinaEdZYakNIHVQW+rRkQKa1VEQYh5oD10VVDU= 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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id AC3ED3850204 for ; Wed, 13 Jul 2022 18:24:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AC3ED3850204 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-35-dfn_rNz5NVejqwuIJvzwuA-1; Wed, 13 Jul 2022 14:24:19 -0400 X-MC-Unique: dfn_rNz5NVejqwuIJvzwuA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E1F8D1C06EDA for ; Wed, 13 Jul 2022 18:24:18 +0000 (UTC) Received: from pdp-11.hsd1.ma.comcast.net (unknown [10.22.9.75]) by smtp.corp.redhat.com (Postfix) with ESMTP id CC18B1415117 for ; Wed, 13 Jul 2022 18:24:18 +0000 (UTC) To: GCC Patches Subject: [pushed] libcpp: Avoid pessimizing std::move [PR106272] Date: Wed, 13 Jul 2022 14:24:14 -0400 Message-Id: <20220713182414.58583-1-polacek@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-13.3 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_LOW, 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-Patchwork-Original-From: Marek Polacek via Gcc-patches From: Marek Polacek Reply-To: Marek Polacek Errors-To: gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org Sender: "Gcc-patches" X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1738262923848607556?= X-GMAIL-MSGID: =?utf-8?q?1738262923848607556?= std::move in a return statement can prevent the NRVO: PR106272 reports that we have two such cases in class label_text's member functions. We have -Wpessimizing-move that's supposed to detect problematic std::move uses, but in this case it didn't trigger. I've filed PR106276 to track that. Tested x86_64-pc-linux-gnu, applying to trunk. PR preprocessor/106272 libcpp/ChangeLog: * include/line-map.h (class label_text): Don't std::move in a return statement. --- libcpp/include/line-map.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) base-commit: f70c18524221dcefa6cd26cee7b55503181bd912 diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h index c6379ce25b8..c434a246b13 100644 --- a/libcpp/include/line-map.h +++ b/libcpp/include/line-map.h @@ -1873,13 +1873,13 @@ public: longer-lived owner. */ static label_text borrow (const char *buffer) { - return std::move (label_text (const_cast (buffer), false)); + return label_text (const_cast (buffer), false); } /* Create a label_text instance that takes ownership of BUFFER. */ static label_text take (char *buffer) { - return std::move (label_text (buffer, true)); + return label_text (buffer, true); } /* Take ownership of the buffer, copying if necessary. */