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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH, URIBL_BLOCKED,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 D17A2C04AB5 for ; Thu, 6 Jun 2019 20:30:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3A662083E for ; Thu, 6 Jun 2019 20:30:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="LNCjE7Zr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727349AbfFFUaN (ORCPT ); Thu, 6 Jun 2019 16:30:13 -0400 Received: from mail-it1-f193.google.com ([209.85.166.193]:51858 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727110AbfFFUaN (ORCPT ); Thu, 6 Jun 2019 16:30:13 -0400 Received: by mail-it1-f193.google.com with SMTP id m3so2135158itl.1 for ; Thu, 06 Jun 2019 13:30:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=CMffxpzzNeHPnyHxq1DkhRwOhkIOW8SKyDW+whl/MBM=; b=LNCjE7ZroqyYbWBkBxyLftTFqv8ooPNexUhuVqcbnGoXeZEiuGJCy2CHT+FaQUdCC0 dguO9W4gajtKWHjb+/8VUG+FCuzfUNrp9Tui6irD9ewHiMbldRFGJ6YhQESbPw1ioV0P 2iecLE6raDsvrflU0W8WA1tJ+W1+nokkS0N4M= 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:mime-version :content-transfer-encoding; bh=CMffxpzzNeHPnyHxq1DkhRwOhkIOW8SKyDW+whl/MBM=; b=pUBpnFQ6jcXEKpliast2dufDuFaY9jDkguhsazDquQ230CAr4vaTGeMKn5nRq/VdLK GhN37PSH2WHHc8a1yapkKIHjaiHE3uxJFnAUFmpXjGpSDsuoQwJ7DF4gHokoyL8Eb7NL tBVB+LVyLV1lh8+YesW75RhotFxbggP7edpkv9xus1LMkoIzMXKOy492FXrcLpyLgngS uxh5bPiCCHWVSm//HRc5Z4LicwK16emBTpec7HKqZNJCB+TNKoz+LAbmzFa1/zRk02rK iBBzoTr40ebMijaWccDguUkTBbe6BmwYB7xNBOlhLryIb/vNio8WDOQocuYfOKknTi2r wi1A== X-Gm-Message-State: APjAAAUWdbYEvqXKmgVrLbHpC/puzVWwrAP4hyaWJNTEyJ0cyOGxnOYF xEg4+VHiTX5eaQtsu0mt6xO4VQ== X-Google-Smtp-Source: APXvYqwLM54vHHQKeM7hNiAZxdj6iSn3l/ZcdXxvNkqtY7eYrBYhgAUkxItdVGznXuRPoCHUUgeEVA== X-Received: by 2002:a24:5710:: with SMTP id u16mr1536035ita.67.1559853012190; Thu, 06 Jun 2019 13:30:12 -0700 (PDT) Received: from localhost ([2620:15c:183:0:20b8:dee7:5447:d05]) by smtp.gmail.com with ESMTPSA id j23sm1039331ioo.6.2019.06.06.13.30.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Jun 2019 13:30:11 -0700 (PDT) From: Raul E Rangel To: yamada.masahiro@socionext.com Cc: mka@chromium.org, ndesaulniers@google.com, zwisler@chromium.org, Raul E Rangel , Joe Lawrence , Kees Cook , linux-kbuild@vger.kernel.org, Petr Mladek , linux-kernel@vger.kernel.org, Michal Marek , Andy Shevchenko , Changbin Du , Tetsuo Handa , Sri Krishna chowdary , Matthew Wilcox , Mikulas Patocka , Andrew Morton Subject: [RFC PATCH] kbuild: Add option to generate a Compilation Database Date: Thu, 6 Jun 2019 14:30:03 -0600 Message-Id: <20190606203003.112040-1-rrangel@chromium.org> X-Mailer: git-send-email 2.22.0.rc1.311.g5d7573a151-goog 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 Clang tooling requires a compilation database to figure out the build options for each file. This enables tools like clang-tidy and clang-check. See https://clang.llvm.org/docs/HowToSetupToolingForLLVM.html for more information. Normally cmake is used to generate the compilation database, but the linux kernel uses make. Another option is using [BEAR](https://github.com/rizsotto/Bear) which instruments exec to find clang invocations and generate the database that way. Clang 4.0.0 added the -MJ option to generate the json for each compilation unit. https://reviews.llvm.org/D27140 This patch takes advantage of the -MJ option. So it only works for Clang. Signed-off-by: Raul E Rangel --- I have a couple TODOs in the code that I would like some feedback on. Specifically why extra-y doesn't seem to work in the root Makefile. Also, is there a way to add the correct list of prerequisites to the compile_commands.json target? Thanks, Raul Makefile | 20 ++++++++++++++++++++ lib/Kconfig.debug | 7 +++++++ scripts/Makefile.build | 9 ++++++++- 3 files changed, 35 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index a61a95b6b38f7..06067ee18ff64 100644 --- a/Makefile +++ b/Makefile @@ -1663,6 +1663,26 @@ quiet_cmd_tags = GEN $@ tags TAGS cscope gtags: FORCE $(call cmd,tags) +# Compilation Database +# --------------------------------------------------------------------------- +# Generates a compilation database that can be used with the LLVM tools +ifdef CONFIG_COMPILATION_DATABASE + +quiet_cmd_compilation_db = GEN $@ +cmd_compilation_db = (echo '['; \ + find "$(@D)" -mindepth 2 -iname '*.json' -print0 | xargs -0 cat; \ + echo ']') > "$(@D)/$(@F)" + +# Make sure the database is built when calling `make` without a target. +# TODO: Using extra-y doesn't seem to work. +_all: $(obj)/compile_commands.json + +# TODO: Is there a variable that contains all the object files created by +# cmd_cc_o_c? Depending on `all` is kind of a hack +$(obj)/compile_commands.json: all FORCE + $(call if_changed,compilation_db) +endif + # Scripts to check various things for consistency # --------------------------------------------------------------------------- diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index eae43952902eb..46fceb1fff3d9 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -238,6 +238,13 @@ config GDB_SCRIPTS instance. See Documentation/dev-tools/gdb-kernel-debugging.rst for further details. +config COMPILATION_DATABASE + bool "Generate a compilation database" + depends on CLANG_VERSION >= 40000 + help + This creates a JSON Compilation Database (compile_commands.json) + that is used by the clang tooling (clang-tidy, clang-check, etc). + config ENABLE_MUST_CHECK bool "Enable __must_check logic" default y diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ae9cf740633e1..0017bf397292d 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -145,8 +145,15 @@ $(obj)/%.ll: $(src)/%.c FORCE # The C file is compiled and updated dependency information is generated. # (See cmd_cc_o_c + relevant part of rule_cc_o_c) +ifdef CONFIG_COMPILATION_DATABASE +# TODO: Should we store the json in a temp variable and only copy it to the +# final name when the content is different? In theory we could avoid having to +# generate the compilation db if the json did not change. +compdb_flags = -MJ $(@D)/.$(@F).json +endif + quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ - cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< + cmd_cc_o_c = $(CC) $(c_flags) $(compdb_flags) -c -o $@ $< ifdef CONFIG_MODVERSIONS # When module versioning is enabled the following steps are executed: -- 2.22.0.rc1.311.g5d7573a151-goog