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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20F29C433FE for ; Thu, 13 Oct 2022 18:51:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231239AbiJMSvD (ORCPT ); Thu, 13 Oct 2022 14:51:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231767AbiJMSub (ORCPT ); Thu, 13 Oct 2022 14:50:31 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EC30E099E for ; Thu, 13 Oct 2022 11:48:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665686856; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Ji+NyK6PnYbavkYjDFsnOf76oGImlagiYlW5om5fOkg=; b=S8VPUNEyEuyv6Br8y1qKsT9pT9tSj0GPA2PcfHsxMTTPh/NPVTo4tp3TQA71ywlojPpUT4 tVGIAmPTPiyWv/B+q0YzypryFsOa5hEwhJiJ4Qx2HdSktolySroHsYLDBBIDsblo+7REHl i3WvHmQz6AGnzjN5lRRaKLMrAQngIiM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-640-pgkOP4lWMnq5PGbJSSkoLg-1; Thu, 13 Oct 2022 14:39:17 -0400 X-MC-Unique: pgkOP4lWMnq5PGbJSSkoLg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1466D185A7A8; Thu, 13 Oct 2022 18:39:17 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.2.16.73]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9E0AA40F16A; Thu, 13 Oct 2022 18:39:15 +0000 (UTC) From: Florian Weimer To: "Jason A. Donenfeld" Cc: Mark Brown , linux-toolchains@vger.kernel.org, Linux Kbuild mailing list , LKML Subject: Re: gcc 5 & 6 & others already out of date? References: Date: Thu, 13 Oct 2022 20:39:13 +0200 In-Reply-To: (Jason A. Donenfeld's message of "Thu, 13 Oct 2022 09:23:36 -0600") Message-ID: <87mt9zwotq.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org * Jason A. Donenfeld: > It's also easy, nearly trivial, to download toolchains. Arnd provides a > bunch with his crosstool. "Must use a toolchain from your distro" is a > requirement that affects nobody. But not everything will be built with the cross-compiler. For the kernel build tools and other userspace components, you'll need a native toolchain that can build programs that can actually run on the build host. At the very least, this means that the right search paths have to be baked into the tools, and I'm not sure this will happen automatically for popular distributions. (I only know that it wouldn't happen for glibc, but you can't really rebuild that.) This seems unexplored territory to me. The existence of working cross-tools doesn't tell us much how native builds and integration with installed native libraries will play out in practice. There's also going to be much greater variance of compilers people actually use if everyone just picks an upstream release branch snapshot at some point in time. None of this may be sufficient reason to support old toolchains. But if you require more recent versions, you really should tell people to upgrade to new distributions, or use newer toolchain versions specifically built for the distribution by their distribution vendor. And not to try to build their own toolchain. Thanks, Florian