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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 34D45C4338F for ; Fri, 30 Jul 2021 21:55:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B8FD6024A for ; Fri, 30 Jul 2021 21:55:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231321AbhG3VzC (ORCPT ); Fri, 30 Jul 2021 17:55:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230385AbhG3Vyx (ORCPT ); Fri, 30 Jul 2021 17:54:53 -0400 Received: from mail-lj1-x22b.google.com (mail-lj1-x22b.google.com [IPv6:2a00:1450:4864:20::22b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC3C0C061765 for ; Fri, 30 Jul 2021 14:54:46 -0700 (PDT) Received: by mail-lj1-x22b.google.com with SMTP id r23so14349053lji.3 for ; Fri, 30 Jul 2021 14:54:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7aKMKn982p52Fvo+RafbN4nbzmOZcaHi43o8L8qnY+4=; b=e3gD2omhgrGKs5t8W/r7K60LV5VhuqUli3ecVKeHtZwHM7LBwgxR5XeOkr9ewdjd2c xj7a/kTRU7IGkPLriaWTtOL1eBK9al/wjxGWkB8yqh2majJgR9YYX+ywzrfrf/V9JOXZ zWJXESZp+8E/VgCG4qnblM8fAdGwsxYdb03HI= 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=7aKMKn982p52Fvo+RafbN4nbzmOZcaHi43o8L8qnY+4=; b=gwggE/BV0jix+7UATmKQMZH/4Wioyn+y3P8G2CAsh4NWXH8x9OcC1k1MUyHN7MAdu2 tdvBD4rWWtcgMbW+fwtXd0EGPnLErL9rzZBPLUuncxfUQYQEpAmiX/QibyvC79PeG0AF HG1bR1sQDTHTPM3bKdfTfyrJor1GVh1b3qcIej9cOW0bgZgrw8Dfxmxb9lTDe6kkRSRC zZJwrEJ64ZzeQdNZve+BjjPsssNEzHcQrm1z4g8S0lbyeqJiJ8cCwG9wUgZF6OA6OKFv WELRRX0ZM1hOoa/sUxL0TfFK+WO0oKOLV2j90UlOxkOMrs6mopFagWDwFDsjC6oH5zay aAKQ== X-Gm-Message-State: AOAM530qPGs30uO+k6tgEabxDoECN7svTg/IWkeX6UzSMYEJKvP9X/up nInq9RNbbNUAkSKC5cC0YLfddsIzhPMu8Wwd X-Google-Smtp-Source: ABdhPJw7MelbxpsB6pKPkaTn9dtVGPrpxjLjn8um8cMhNtRZ+frqRg2Ssnc8SXjYT/XAMvXPk8nbVw== X-Received: by 2002:a2e:9599:: with SMTP id w25mr3162160ljh.271.1627682084629; Fri, 30 Jul 2021 14:54:44 -0700 (PDT) Received: from mail-lf1-f52.google.com (mail-lf1-f52.google.com. [209.85.167.52]) by smtp.gmail.com with ESMTPSA id e21sm269900lfq.240.2021.07.30.14.54.42 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 30 Jul 2021 14:54:43 -0700 (PDT) Received: by mail-lf1-f52.google.com with SMTP id m13so20600852lfg.13 for ; Fri, 30 Jul 2021 14:54:42 -0700 (PDT) X-Received: by 2002:a19:c3c1:: with SMTP id t184mr3428280lff.41.1627682071251; Fri, 30 Jul 2021 14:54:31 -0700 (PDT) MIME-Version: 1.0 References: <20210730201701.3146910-1-ndesaulniers@google.com> <20210730201701.3146910-2-ndesaulniers@google.com> In-Reply-To: <20210730201701.3146910-2-ndesaulniers@google.com> From: Linus Torvalds Date: Fri, 30 Jul 2021 14:54:15 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v4 1/2] Makefile: infer --target from ARCH for CC=clang To: Nick Desaulniers Cc: Masahiro Yamada , Miguel Ojeda , Fangrui Song , Michal Marek , Arnd Bergmann , Linux Kernel Mailing List , Linux Kbuild mailing list , clang-built-linux , Geert Uytterhoeven , Christoph Hellwig , Nathan Chancellor 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: > > +ifeq ($(SRCARCH),arm) > +CLANG_FLAGS += --target=arm-linux-gnueabi ..,. Ugh. A wise man once said: "All problems in computer science can be solved with another level of indirection". Just do it like this: CLANG_TARGET_FLAGS_arm = arm-linux-gnueabi CLANG_TARGET_FLAGS_hexagon = hexagon-linux-gnu .. CLANG_TARGET_FLAGS = $(CLANG_TARGET_FLAGS_$(ARCH)) Which is a lot denser and simpler. And then the only if-statement can be something along the lines of ifeq ($(CLANG_TARGET_FLAGS),) $(error Specify clang target flags) else CLANG_FLAGS += --target=$(CLANG_TARGET_FLAGS) endif Plus add *random handwaving* about all the details for CROSS_COMPILE and friends. Linus