From patchwork Fri Jan 22 01:39:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiezhu Yang X-Patchwork-Id: 12038129 X-Patchwork-Delegate: bpf@iogearbox.net 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=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 B927CC433DB for ; Fri, 22 Jan 2021 01:41:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B17F22B43 for ; Fri, 22 Jan 2021 01:41:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726456AbhAVBlP (ORCPT ); Thu, 21 Jan 2021 20:41:15 -0500 Received: from mail.loongson.cn ([114.242.206.163]:38040 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725775AbhAVBlI (ORCPT ); Thu, 21 Jan 2021 20:41:08 -0500 Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9DxS+TgLApgnQAJAA--.14315S2; Fri, 22 Jan 2021 09:39:46 +0800 (CST) From: Tiezhu Yang To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Nathan Chancellor , Nick Desaulniers Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org, Xuefeng Li , Fangrui Song Subject: [PATCH bpf-next v4] samples/bpf: Update build procedure for manually compiling LLVM and Clang Date: Fri, 22 Jan 2021 09:39:44 +0800 Message-Id: <1611279584-26047-1-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 X-CM-TRANSID: AQAAf9DxS+TgLApgnQAJAA--.14315S2 X-Coremail-Antispam: 1UD129KBjvJXoWxKrWfZFyUAFyktw4xAr4Dtwb_yoW7uryDpw 13ta4SgrZ7tryfXFyxGF48XF4fZr4kXa4UCa4xJrykAF1qvwn7Kr43trWrKFW7Jr92kr45 Cw1rKay5uF1UXaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9Y14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AKxV W8Jr0_Cr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xf McIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7 v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF 7I0E8cxan2IY04v7MxkIecxEwVAFwVWkMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4 AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE 17CEb7AF67AKxVW8ZVWrXwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMI IF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_WFyUJVCq 3wCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCT nIWIevJa73UjIFyTuYvjfUOMKZDUUUU X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The current LLVM and Clang build procedure in samples/bpf/README.rst is out of date. See below that the links are not accessible any more. $ git clone http://llvm.org/git/llvm.git Cloning into 'llvm'... fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed $ git clone --depth 1 http://llvm.org/git/clang.git Cloning into 'clang'... fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed The LLVM community has adopted new ways to build the compiler. There are different ways to build LLVM and Clang, the Clang Getting Started page [1] has one way. As Yonghong said, it is better to copy the build procedure in Documentation/bpf/bpf_devel_QA.rst to keep consistent. I verified the procedure and it is proved to be feasible, so we should update README.rst to reflect the reality. At the same time, update the related comment in Makefile. Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change Documentation/bpf/bpf_devel_QA.rst together. At last, we recommend that developers who want the fastest incremental builds use the Ninja build system [1], you can find it in your system's package manager, usually the package is ninja or ninja-build [3], so add ninja to build dependencies suggested by Nathan. [1] https://clang.llvm.org/get_started.html [2] https://www.llvm.org/docs/CMake.html [3] https://github.com/ninja-build/ninja/wiki/Pre-built-Ninja-packages Signed-off-by: Tiezhu Yang Acked-by: Yonghong Song Reviewed-by: Nathan Chancellor --- v2: Update the commit message suggested by Yonghong, thank you very much. v3: Remove the default option BUILD_SHARED_LIBS=OFF and just mkdir llvm-project/llvm/build suggested by Fangrui. v4: Add some description about ninja suggested by Nathan. Documentation/bpf/bpf_devel_QA.rst | 11 +++++++---- samples/bpf/Makefile | 2 +- samples/bpf/README.rst | 22 ++++++++++++++-------- 3 files changed, 22 insertions(+), 13 deletions(-) diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst index 5b613d2..2ed89ab 100644 --- a/Documentation/bpf/bpf_devel_QA.rst +++ b/Documentation/bpf/bpf_devel_QA.rst @@ -501,16 +501,19 @@ All LLVM releases can be found at: http://releases.llvm.org/ Q: Got it, so how do I build LLVM manually anyway? -------------------------------------------------- -A: You need cmake and gcc-c++ as build requisites for LLVM. Once you have -that set up, proceed with building the latest LLVM and clang version +A: We recommend that developers who want the fastest incremental builds +use the Ninja build system, you can find it in your system's package +manager, usually the package is ninja or ninja-build. + +You need ninja, cmake and gcc-c++ as build requisites for LLVM. Once you +have that set up, proceed with building the latest LLVM and clang version from the git repositories:: $ git clone https://github.com/llvm/llvm-project.git - $ mkdir -p llvm-project/llvm/build/install + $ mkdir -p llvm-project/llvm/build $ cd llvm-project/llvm/build $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \ -DLLVM_ENABLE_PROJECTS="clang" \ - -DBUILD_SHARED_LIBS=OFF \ -DCMAKE_BUILD_TYPE=Release \ -DLLVM_BUILD_RUNTIME=OFF $ ninja diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 26fc96c..d061446 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock += -pthread -lcap TPROGLDLIBS_xsk_fwd += -pthread # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: -# make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang LLC ?= llc CLANG ?= clang OPT ?= opt diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst index dd34b2d..60c6494 100644 --- a/samples/bpf/README.rst +++ b/samples/bpf/README.rst @@ -62,20 +62,26 @@ To generate a smaller llc binary one can use:: -DLLVM_TARGETS_TO_BUILD="BPF" +We recommend that developers who want the fastest incremental builds +use the Ninja build system, you can find it in your system's package +manager, usually the package is ninja or ninja-build. + Quick sniplet for manually compiling LLVM and clang -(build dependencies are cmake and gcc-c++):: +(build dependencies are ninja, cmake and gcc-c++):: - $ git clone http://llvm.org/git/llvm.git - $ cd llvm/tools - $ git clone --depth 1 http://llvm.org/git/clang.git - $ cd ..; mkdir build; cd build - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86" - $ make -j $(getconf _NPROCESSORS_ONLN) + $ git clone https://github.com/llvm/llvm-project.git + $ mkdir -p llvm-project/llvm/build + $ cd llvm-project/llvm/build + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \ + -DLLVM_ENABLE_PROJECTS="clang" \ + -DCMAKE_BUILD_TYPE=Release \ + -DLLVM_BUILD_RUNTIME=OFF + $ ninja It is also possible to point make to the newly compiled 'llc' or 'clang' command via redefining LLC or CLANG on the make command line:: - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang Cross compiling samples -----------------------