From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDE8BC282DA for ; Tue, 5 Feb 2019 15:07:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AF362184B for ; Tue, 5 Feb 2019 15:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549379251; bh=i0PF0J7D9errSUQ3SotWziEdPhuNmTaxA2UKA9QPTog=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UR7JJTYSGoehK6HBloLBvJKfnWCXldU5YKQrFIrnYHpaRjjiAw5J3RuuXaOvzBNEu 9pmTlqMsJ4f/KpP1zkEczf6B5f7JZRprIj+fcz2qcFZf0ghAhw/rJGS/fC2wXH+0E3 J37OAY3Bjmc/89EZp0CKeNCbJZVKKD8gcQ80i+KE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729692AbfBEPHa (ORCPT ); Tue, 5 Feb 2019 10:07:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:42290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726646AbfBEPH2 (ORCPT ); Tue, 5 Feb 2019 10:07:28 -0500 Received: from quaco.ghostprotocols.net (unknown [190.15.121.82]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D5E922184D; Tue, 5 Feb 2019 15:07:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549379247; bh=i0PF0J7D9errSUQ3SotWziEdPhuNmTaxA2UKA9QPTog=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AXbTdH/qwQnMhOGXIV2D8L0MwgbesQSGBjYaBlL6NoFnV4hsBed9MzoXIa/ORrayt N+1bIXmHONhm/ecVjDk04u/GbsoIHC9SX6zX40eAdy4AA+AjZMNAjPMlv0uhU/Be8/ 0Wg+prHxaLXGqQihpJJRSOEtIo2MFA0L9TzG8tSM= From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Jiri Olsa , =?UTF-8?q?Luis=20Cl=C3=A1udio=20Gon=C3=A7alves?= , Namhyung Kim , Wang Nan Subject: [PATCH 3/8] perf clang: Do not use 'return std::move(something)' Date: Tue, 5 Feb 2019 12:07:03 -0300 Message-Id: <20190205150708.9012-4-acme@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190205150708.9012-1-acme@kernel.org> References: <20190205150708.9012-1-acme@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo It prevents copy elision, generating this warning when building with fedora:rawhide's clang: clang version 7.0.1 (Fedora 7.0.1-2.fc30) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /usr/bin Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/9 Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/9 Selected GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/9 Candidate multilib: .;@m64 Candidate multilib: 32;@m32 Selected multilib: .;@m64 $ make -C tools/perf CC=clang LIBCLANGLLVM=1 util/c++/clang.cpp: In function 'std::unique_ptr > perf::getBPFObjectFromModule(llvm::Module*)': util/c++/clang.cpp:163:18: error: moving a local object in a return statement prevents copy elision [-Werror=pessimizing-move] 163 | return std::move(Buffer); | ~~~~~~~~~^~~~~~~~ util/c++/clang.cpp:163:18: note: remove 'std::move' call cc1plus: all warnings being treated as errors References: http://www.cplusplus.com/forum/general/186411/#msg908572 https://en.cppreference.com/w/cpp/language/return#Notes https://en.cppreference.com/w/cpp/language/copy_elision Cc: Adrian Hunter Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-lehqf5x5q96l0o8myhb6blz6@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/c++/clang.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp index 89512504551b..39c0004f2886 100644 --- a/tools/perf/util/c++/clang.cpp +++ b/tools/perf/util/c++/clang.cpp @@ -160,7 +160,7 @@ getBPFObjectFromModule(llvm::Module *Module) } PM.run(*Module); - return std::move(Buffer); + return Buffer; } } -- 2.20.1