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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, 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 976EEC282C4 for ; Tue, 22 Jan 2019 23:39:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 648B421726 for ; Tue, 22 Jan 2019 23:39:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="R8sGZjXm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726964AbfAVXjO (ORCPT ); Tue, 22 Jan 2019 18:39:14 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:33225 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726934AbfAVXjL (ORCPT ); Tue, 22 Jan 2019 18:39:11 -0500 Received: by mail-it1-f196.google.com with SMTP id m8so10855044itk.0 for ; Tue, 22 Jan 2019 15:39:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=android.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=iNLqZdvEm5CxeKT6RdyYcEltmMyKybFyRQUZBsiBNFA=; b=R8sGZjXmfr0NKQLuiqdaFQyNglBl7T9PIc9fo4phgxtQj4LBR3SbSgchzkbSHR9hwG Mh3yGz/0T/cJ9q/LBab1VxKb48oPDsMBW7CVCho4/qBsbSKMoJWlJSURQx9sAO6n6wDN fZ4v9J+/zdsqe5UwdxPWnvprOA6ilaiVevTWWCwBhdbKHfBGODvNj+xW76yq/nd3Sqan QGu33VHwKYYlj9atubT10ceRmn5gww4KfdcNgFgP1heLXWoH1o+Os15aEkipiTtYI9A7 kX2EzMLLCjQmIkEBKanq5JfAL1r7JbqCwMK45MCMFHy0IPw5PtSP+5i8/y/KVMVHDhIA xEBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=iNLqZdvEm5CxeKT6RdyYcEltmMyKybFyRQUZBsiBNFA=; b=mbzKJcdwHuXCZdYbzVHH/j8osztIoNVPabZyarCnHsK/PhgGeTIvaOiqMD0c/k9TOL OFox/QXktZXECoaVQU3UPPn4uhUW8zlLsYB3ShSoMNyAA3xRPXtsQUKtz2ny9N3CMvUh bGzffmk1BQCPHitih2XJQpiNp9EDiK4fAHW0+cpLS4iZ1T0xvuazmOXw7ZDvIctErGxN xqLpKN+bWAjWLiq9uq2wvFCMJpixgR7LNYi1d9UPUXZaSbJJbbOQaz7DZ2FBEvVzikXq m5GJeS0iilmZM88wqZVf1uKGrV9BC2+6E87RYobdg2uA5jp+cnvl/ePAeyZHMuQA4LDr DUXA== X-Gm-Message-State: AHQUAubmwsDVQBj9w0z86qSfgJBiGRx2xcbLyp98Q7q+oUE6QFHlJttP 1j5HvDxrywrB2osqKyqYMBtPMQ== X-Google-Smtp-Source: AHgI3IbAi83tNb4xc7JVndkEmo1tPl98/gEs0c2kVZE8TlA6cwE3qDP54BIeqfQ1VKSH8sY3ngO35Q== X-Received: by 2002:a24:c456:: with SMTP id v83mr374543itf.44.1548200350277; Tue, 22 Jan 2019 15:39:10 -0800 (PST) Received: from trong0.mtv.corp.google.com ([2620:0:1000:1601:c43f:8c1b:f6ef:3dce]) by smtp.gmail.com with ESMTPSA id g186sm8058823ite.39.2019.01.22.15.39.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 Jan 2019 15:39:09 -0800 (PST) From: Tri Vo To: oberpar@linux.ibm.com Cc: ghackmann@android.com, ndesaulniers@google.com, linux-kernel@vger.kernel.org, kernel-team@android.com, yamada.masahiro@socionext.com, Tri Vo Subject: [PATCH v3 3/3] gcov: docs: add a note on GCC vs Clang differences Date: Tue, 22 Jan 2019 15:37:49 -0800 Message-Id: <20190122233749.42220-4-trong@android.com> X-Mailer: git-send-email 2.20.1.321.g9e740568ce-goog In-Reply-To: <20190122233749.42220-1-trong@android.com> References: <20190122233749.42220-1-trong@android.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Document some things of note to gcov users: 1. GCC gcov and Clang llvm-cov tools are not compatible. 2. The use of GCC vs Clang is transparent at build-time. Signed-off-by: Tri Vo --- Documentation/dev-tools/gcov.rst | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/Documentation/dev-tools/gcov.rst b/Documentation/dev-tools/gcov.rst index 69a7d90c320a..46aae52a41d0 100644 --- a/Documentation/dev-tools/gcov.rst +++ b/Documentation/dev-tools/gcov.rst @@ -34,10 +34,6 @@ Configure the kernel with:: CONFIG_DEBUG_FS=y CONFIG_GCOV_KERNEL=y -select the gcc's gcov format, default is autodetect based on gcc version:: - - CONFIG_GCOV_FORMAT_AUTODETECT=y - and to get coverage data for the entire kernel:: CONFIG_GCOV_PROFILE_ALL=y @@ -169,6 +165,20 @@ b) gcov is run on the BUILD machine [user@build] gcov -o /tmp/coverage/tmp/out/init main.c +Note on compilers +----------------- + +GCC and LLVM gcov tools are not necessarily compatible. Use gcov_ to work with +GCC-generated .gcno and .gcda files, and use llvm-cov_ for Clang. + +.. _gcov: http://gcc.gnu.org/onlinedocs/gcc/Gcov.html +.. _llvm-cov: https://llvm.org/docs/CommandGuide/llvm-cov.html + +Build differences between GCC and Clang gcov are handled by Kconfig. It +automatically selects the appropriate gcov format depending on the detected +toolchain. + + Troubleshooting --------------- -- 2.20.1.321.g9e740568ce-goog