From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754653AbXHAU2a (ORCPT ); Wed, 1 Aug 2007 16:28:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751347AbXHAU2W (ORCPT ); Wed, 1 Aug 2007 16:28:22 -0400 Received: from waste.org ([66.93.16.53]:44789 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751167AbXHAU2V (ORCPT ); Wed, 1 Aug 2007 16:28:21 -0400 Date: Wed, 1 Aug 2007 15:28:15 -0500 From: Matt Mackall To: Richard Knutsson Cc: Mike Frysinger , Robin Getz , Yoann Padioleau , David Howells , kernel-janitors@vger.kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 06/68] 0 -> NULL, for arch/frv Message-ID: <20070801202815.GL11166@waste.org> References: <200707270944.LAA17167@ifs.emn.fr> <22618.1185531297@redhat.com> <87lkd29mk9.fsf@wanadoo.fr> <200707272138.23323.rgetz@blackfin.uclinux.org> <8bd0f97a0707271837q5d5f31d9pe342e72ebf9368c1@mail.gmail.com> <46AF255A.4050106@student.ltu.se> <8bd0f97a0708010303j7f443b06lf9d77f6d36816237@mail.gmail.com> <46B062AF.1040907@student.ltu.se> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46B062AF.1040907@student.ltu.se> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 01, 2007 at 12:38:39PM +0200, Richard Knutsson wrote: > Mike Frysinger wrote: > >On 7/31/07, Richard Knutsson wrote: > > > >>Mike Frysinger wrote: > >> > >>>On 7/27/07, Robin Getz wrote: > >>> > >>>>If there is a definite style or semantic preference that everyone > >>>>should live > >>>>with - does it make sense to put checks in checkpatch.pl to enforce it? > >>>> > >>>checkpatch.pl does not have enough semantic knowledge to know if the > >>>thing being tested is a pointer ... dont know if the sparse utility > >>>would be able to pick it out as i'm not familiar with what level that > >>>thing runs at > >>> > >>Didn't he mean "x == NULL" > "!x"? > >> > > > >i'm sure i understand your meaning of ">" ... are you saying that "x > >== NULL" is greater (preferred) to "!x" or are you saying that "x == > >NULL" should be changed to "!x" ? > > > If I understood Robin correctly, he suggested that checkpatch.pl would > tell to convert "x == NULL" to "!x", if that would be the preferred way. > >i dont think the former case can be checked by checkpatch.pl, but the > >latter certainly can ... but i'd be very skeptical you could get the > >wider LKML audience to sign off one way or the other wrt to "x == > >NULL" vs "!x". you can certainly get people to sign off on "x == 0" > >being wrong when x is a pointer. > > > I agree! > BTW, too bad checkpatch.pl does not know the types, since it otherwise > could check for the "x [=!]= 0"-thing. About the only place that if (x != 0) is preferred to if (x) is cases where the 0 value doesn't semantically correspond to false/off/disabled. And that's basically thing that return 0 for success and negative errors. -- Mathematics is the supreme nostalgia of our time.