Received: by 2002:a05:6a10:2785:0:0:0:0 with SMTP id ia5csp206884pxb; Thu, 14 Jan 2021 04:00:43 -0800 (PST) X-Google-Smtp-Source: ABdhPJzXVD8cWEjiG4JGgZJC3BbLzlXWbjWcg+ymiMW06e1qXzT+2QKnnaYZtO2OI3wcQEXATzSM X-Received: by 2002:a50:8a90:: with SMTP id j16mr5285839edj.334.1610625642880; Thu, 14 Jan 2021 04:00:42 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1610625642; cv=none; d=google.com; s=arc-20160816; b=zYZ4k6b4VHv964Z20ciIlUabmRvBN2cQnbUvvKBlLcrwRXwyTmykuuVs+UhOrDIO1O cF8R38aJ7aWRSKuxURdGR5RZyCzPdlwSY54owJxzVMOhDNyOsgrIVrKRTOcUEpRD8wdu hwPLK81GtkSRJc6hBsM0XqwnAcsMPtjYUnpUOV9ZKLIAHD10rkhkCy5FYZMCIywDXukt 1ot/Ri2TEN/BGqkEn10aRHrIb/WWHr9/z8JaUW0OyJnaFCrCgVopaPicUDYD7DjMlzmI Tz+ZckfMiAC68GwelPQEQ7lKAri8eLzVsqqDoZZR7u9SK5HwZ2ROJQkPwX2W4FOrV/7Y eRJw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:date:cc:to:from:subject :message-id; bh=9ARjyfSUIQmG+7P3dZm5G/YlNM+1YtXMGrA/PAlsxl0=; b=dIE1NM9egW0gr9jvUMEbCozA41LMu/O+vnG46pGpyavE9Sc6amTejt1rLhPWjDMpSz vu1Q5GhhapCiqvBnZjCYLBt0vugIJcP+svDxsOMUwLj6f6F7ojq0vXsyDJHN8KHcvXRF cSN+wIyLWqwUqB3lAnPK2T1CBaqumhWYYBcLNgtrSz2m/CTqQRV4rbIi+JeoSFJQsxRD wQf4thOSO2eMmzBKvcQdPBocsG8Try0w2Tn48LjVXBZJ2LJ0kpeTjAOn9aFBG/MqeicM qdhExig36NCWl5ZcOI3rcUdSHnK2O4Y6rkoGgD+MNSoU9B+ZQ+uLdEDdFxVX4EDVscZc UNzA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id x27si2466648ejb.485.2021.01.14.04.00.18; Thu, 14 Jan 2021 04:00:42 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728266AbhANL5H (ORCPT + 99 others); Thu, 14 Jan 2021 06:57:07 -0500 Received: from esgaroth.petrovitsch.at ([78.47.184.11]:4031 "EHLO esgaroth.tuxoid.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726376AbhANL5E (ORCPT ); Thu, 14 Jan 2021 06:57:04 -0500 Received: from thorin.petrovitsch.priv.at (80-110-120-15.cgn.dynamic.surfer.at [80.110.120.15]) (authenticated bits=0) by esgaroth.tuxoid.at (8.15.2/8.15.2) with ESMTPSA id 10EBtQms024298 (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO); Thu, 14 Jan 2021 12:55:27 +0100 Message-ID: <53fccf6d59938e94f71a823d704e26903b98fb7d.camel@petrovitsch.priv.at> Subject: Re: Toolchain-dependent config options From: Bernd Petrovitsch To: Masahiro Yamada , Josh Poimboeuf Cc: Linux Kbuild mailing list , Linux Kernel Mailing List Date: Thu, 14 Jan 2021 12:55:26 +0100 In-Reply-To: References: <20210113222112.ej4rrd5xw2pwegvw@treble> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-DCC--Metrics: esgaroth.tuxoid.at 1481; Body=4 Fuz1=4 Fuz2=4 X-Virus-Scanned: clamav-milter 0.97 at esgaroth.tuxoid.at X-Virus-Status: Clean X-Spam-Status: No, score=-0.7 required=5.0 tests=AWL,BAYES_05, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Report: * -0.5 BAYES_05 BODY: Bayes spam probability is 1 to 5% * [score: 0.0319] * 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines * -0.2 AWL AWL: Adjusted score from AWL reputation of From: address X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on esgaroth.tuxoid.at Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all! On Thu, 2021-01-14 at 13:56 +0900, Masahiro Yamada wrote: > On Thu, Jan 14, 2021 at 7:21 AM Josh Poimboeuf wrote: [...] > > If I copy a config with CONFIG_GCC_PLUGINS to another system which > > doesn't have the gcc-plugin-devel package, it gets silently disabled by > > "make olddefconfig". > > > > I've seen multiple cases lately where this is causing confusion. I > > suspect the problem is getting worse with recent added support for a > > variety of toolchains and toolchain-dependent features. > > > > Would it be possible to have an error (or at least a warning) in this > > case? > > > > For example, a "depends-error" which triggers an error if its failure > > would disable a feature? [...] > We disable any feature that is unsupported by the compiler in use. > > Conventionally, we did that in the top Makefile > by using $(call cc-option, ) macro or by running some scripts. > > Recently, we are moving such compiler tests to the Kconfig stage. > > Anyway, we disable unsupported features so any combination > of CONFIG options builds successfully. > This will ease randconfg and allmodconfig tests. For options of $CC, that makes sense since there are different compilers and lots of versions of them out there. > A lot of people and CI systems are running allmodconfig tests > for various architectures and toolchains. Isn't some kind of defying (or more killing) the usefulness of regression compile runs if one does `make allmodconfig` and some (lots?) of stuff gets automatically configured out just because some -dev(|el) package is missing? Aren't there some kernel-build meta packages for various distributions out there that pull all necessary in? > Introducing the build breakage is annoying. Yes, update/install the necessary package to fix it. MfG, Bernd -- Bernd Petrovitsch Email : bernd@petrovitsch.priv.at There is no cloud, just other people computers. - FSFE LUGA : http://www.luga.at