From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753920Ab3GJB0L (ORCPT ); Tue, 9 Jul 2013 21:26:11 -0400 Received: from intranet.asianux.com ([58.214.24.6]:43228 "EHLO intranet.asianux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751237Ab3GJB0K (ORCPT ); Tue, 9 Jul 2013 21:26:10 -0400 X-Spam-Score: -100.8 Message-ID: <51DCB336.5040405@asianux.com> Date: Wed, 10 Jul 2013 09:04:54 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: "linux-kernel@vger.kernel.org" Subject: [Information] gcc '-O2' may skip some of uninitialized variables warnings (exist almost 10 years). Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hell All: gcc '-O2' may skip some of uninitialized variables warnings which may be real bugs. This is gcc issue which keep existence almost 10 years, and now it seems can not be fixed in recent years. Please reference: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18501, for kernel special case, also can reference: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57856 If we want to see the warnings (for finding bugs), "EXTRA_CFLAGS=-W" seems not enough (it use '-O2'), I recommend also to try '-O0' (although it may also print many spurious warnings) Thanks. -- Chen Gang