From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756116AbaFPVOM (ORCPT ); Mon, 16 Jun 2014 17:14:12 -0400 Received: from asavdk4.altibox.net ([109.247.116.15]:57106 "EHLO asavdk4.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755567AbaFPVOL (ORCPT ); Mon, 16 Jun 2014 17:14:11 -0400 Date: Mon, 16 Jun 2014 23:14:05 +0200 From: Sam Ravnborg To: Borislav Petkov Cc: lkml , Michael Matz , linux-kbuild@vger.kernel.org, x86-ml Subject: Re: [RFC] Turn off -Wmaybe-uninitialized completely and move it to W=1 Message-ID: <20140616211405.GA7914@ravnborg.org> References: <20140616132045.GE8170@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140616132045.GE8170@pd.tnic> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 16, 2014 at 03:20:45PM +0200, Borislav Petkov wrote: > Hi, > > so 3.16-rc1 adds this false positive from gcc, see below (triggers on > 4.9 and 4.8.2). Now, it is firing wrong and gcc people tell me there's > no way for the compiler to know that the "from" and "to" values will NOT > be used in the error case, i.e. thus the "maybe" aspect. > > So, we've disabled it for -Os already: > > e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building with -Os") > > maybe we want to disable it by default on all and move it to W=1. This > way people can still have it fire but not by default. And from what I've > seen so far, it is mostly firing wrong and it is becoming annoying. > > So what do people think, any reasons for keeping it enabled by default? Agreed. The noise ratio is too high - so move it to W=1. Sam