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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 A6E08C4338F for ; Fri, 30 Jul 2021 21:55:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91E1B60F94 for ; Fri, 30 Jul 2021 21:55:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232715AbhG3VzR (ORCPT ); Fri, 30 Jul 2021 17:55:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232376AbhG3VzD (ORCPT ); Fri, 30 Jul 2021 17:55:03 -0400 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15A3EC0613C1 for ; Fri, 30 Jul 2021 14:54:58 -0700 (PDT) Received: by mail-lf1-x12a.google.com with SMTP id h2so20666725lfu.4 for ; Fri, 30 Jul 2021 14:54:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=faoOQY/6RWuADuNoVKpvGyxjDEO3XlGf6d50QEfJC7g=; b=ZQTRYuq1mRX8347xP8HSAXAa4cJLeXraaLaLYL6GLXd30yRuEBjaeqrsy85g43yYk5 qLCsVgwyL8FkDBESZHruuTsLAyBTkQnuT3Vdy2mjdnlfsgpDmGzMKFBRpwV2ygbNxOTf +CPnpcZehxcxeSZrCHIO7fHrA+bst+Q0S8ecOHsXa0Cek5/yA/tOB8OYSPZ4EybqyMBa 8sVkfE+a6tPRFTb8Hhhn2z2Jwy7OuAQbIEre9GIbU2hh63V1UL0vvgeD57HAwbWobnHw ubnVRE8Yv7iQKp1rsRr4Owh7MlmsZHB0rd5yx6kr2++tj+LitwuPlmMR2YlKO78RnkkQ 67AQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=faoOQY/6RWuADuNoVKpvGyxjDEO3XlGf6d50QEfJC7g=; b=nbZOfWFnjpDDoqtrJbOGscwIpEVNHfurZjPDgU2UsieRamBp6II9g9z0VhgebN724g xvhMlE2si9PDp1urp8e4Vtd3a9A1giS7rS3fJria07bZL2bD+XlURjCUkEQH3WdbmmZn 1XopawReh9ko2fhNPcFLKK8mymWtZ4V4szMaACC4YK2mMpT2vWHxl4neOhqYfBZOB0xL NPa/tu1ltZTOb+X4E6W3+/XPBeanJ6cNwYDZ+fhNPECZ5WNOERJ86pYCv1PmXcOmBhJv n/f4etiMlk+BZOrBmmGdO+6p3KRqQ1ivOxfnqg5ptJMYEkHb1piXQiqJSf3P6AYFqng6 jRSg== X-Gm-Message-State: AOAM5329viRD9vw4060K21DuZXUUrwKGBIuM9Rhp7+gAD+YJOpa52ssk yphfFu+leyQs5+CwQQ1b628Uu2XOdvuBjRuunyrYMw== X-Google-Smtp-Source: ABdhPJwNZcILhR4pmttwbOSL1t8zmWVjqLvvRkn0ZAkRoCwb18QBN4ePQhIpGSSwCZaexTshyitcDN707vjVtpzE27Q= X-Received: by 2002:ac2:59c4:: with SMTP id x4mr2916374lfn.547.1627682096028; Fri, 30 Jul 2021 14:54:56 -0700 (PDT) MIME-Version: 1.0 References: <20210730201701.3146910-1-ndesaulniers@google.com> In-Reply-To: <20210730201701.3146910-1-ndesaulniers@google.com> From: Nick Desaulniers Date: Fri, 30 Jul 2021 14:54:45 -0700 Message-ID: Subject: Re: [PATCH v4 0/2] infer --target from SRCARCH for CC=clang To: Masahiro Yamada Cc: Miguel Ojeda , Fangrui Song , Michal Marek , Arnd Bergmann , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com, Geert Uytterhoeven , Christoph Hellwig , Linus Torvalds Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 30, 2021 at 1:17 PM Nick Desaulniers wrote: > > We get constant feedback that the command line invocation of make is too > long. CROSS_COMPILE is helpful when a toolchain has a prefix of the > target triple, or is an absolute path outside of $PATH, but it's mostly > redundant for a given ARCH. > > Instead, let's infer it from SRCARCH, and move some flag handling into a > new file included from the top level Makefile. > > Changes v3 -> v4: > * Remove the requirement that LLVM_IAS=1 be set, as per Masahiro. > * Remove the Documentation/ change from patch 2, as per Masahiro and > Nathan. > * Add Documentation/ change as patch 3, from Masahiro. > * Reword commit message of patch 2, as per Nathan. > * Change patch 2 oneline to refer to --target and CC=clang (not > CROSS_COMPILE). > * Carry Arnd's and Nathan's AB/RB/TB tags, confirmed ok on IRC+discord. > > Changes v2 -> v3: > * Remove requirement that LLVM=1 be set. Instead, if building with just > CC=clang LLVM_IAS=1 instead of LLVM=1 LLVM_IAS=1, you should use > LD=ld.lld explicitly, or LD=aarch64-linux-gnu-ld. (As per Masahiro) > Example: > > $ ARCH=arm64 make CC=clang LLVM_IAS=1 LD=ld.lld OBJCOPY=llvm-objcopy \ > STRIP=llvm-strip -j72 defconfig all > > (It's still preferable to use LLVM=1 IMO, but this is maximally > flexible.) > * Change oneliner from LLVM=1 to CC=clang. > * Update Docs slightly. > > Changes v1 -> v2: > * patch 1/2 untouched. > * Fix typos in commit message as per Geert and Masahiro. > * Use SRCARCH instead of ARCH, simplifying x86 handling, as per > Masahiro. Add his sugguested by tag. > * change commit oneline from 'drop' to 'infer.' > * Add detail about explicit host --target and relationship of ARCH to > SRCARCH, as per Masahiro. > > *** BLURB HERE *** Err, sorry, it looks like I did: $ git format-patch HEAD~2 ... when I meant to do HEAD~3 ..., will resend. > > Nick Desaulniers (2): > Makefile: infer --target from ARCH for CC=clang > Documentation/llvm: update CROSS_COMPILE inferencing > > Documentation/kbuild/llvm.rst | 17 +++++++++++++++++ > scripts/Makefile.clang | 30 ++++++++++++++++++++++++++++-- > 2 files changed, 45 insertions(+), 2 deletions(-) > > > base-commit: 27932b6a2088eac7a5afa5471963b926cfbb4de7 > prerequisite-patch-id: 0d3072ecb5fd06ff6fd6ea81fe601f6c54c23910 > -- > 2.32.0.554.ge1b32706d8-goog > -- Thanks, ~Nick Desaulniers