From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753069AbaIZAsg (ORCPT ); Thu, 25 Sep 2014 20:48:36 -0400 Received: from mail-pa0-f47.google.com ([209.85.220.47]:56191 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752525AbaIZAsf (ORCPT ); Thu, 25 Sep 2014 20:48:35 -0400 Message-ID: <5424B7DF.4040006@converseincode.com> Date: Thu, 25 Sep 2014 17:48:31 -0700 From: Behan Webster User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Michal Marek CC: ak@linux.intel.com, yamada.m@jp.panasonic.com, hpa@linux.intel.com, linux-kernel@vger.kernel.org, sam@ravnborg.org, Mark Charlebois Subject: Re: [PATCH] kbuild, LLVMLinux: Add -Werror to cc-option to support clang References: <1411500522-11480-1-git-send-email-behanw@converseincode.com> <5422B3EF.4000800@suse.cz> <5423128D.8070708@converseincode.com> <542419CB.3090902@suse.cz> In-Reply-To: <542419CB.3090902@suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/25/14 06:34, Michal Marek wrote: > On 2014-09-24 20:50, Behan Webster wrote: >> Getting clang to error on unused flags wasn't trivial (this change broke >> a lot of builds apparently). Fortunately we weren't the only ones who >> wanted it to behave like gcc in this case. I think it's going to be >> *much* harder to do the same for warnings. The argument given by >> supporters of the current situation is that if a warning isn't >> supported, why break the build? *sigh* > I guess the reason to accept unknown warnings opentions is compatibility > with Makefiles with hardcoded gcc-isms. BTW, GCC at some point started > to ignore unknown -Wno-* options, for everyone's good of course. That's > why we ended up with the cc-disable-warning function. If -W* options for > clang need special care, then it might be a good idea to introduce > cc-warning with the conditional -Werror for clang. There are not that > many places where we add warnings, so the patch would be still short. > That way, the possible silent failure is limited only to warning options > with clang, which is not such a big deal. I'll try this approach. Thanks, Behan -- Behan Webster behanw@converseincode.com