From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757856AbYEXOqr (ORCPT ); Sat, 24 May 2008 10:46:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757282AbYEXOqg (ORCPT ); Sat, 24 May 2008 10:46:36 -0400 Received: from 1wt.eu ([62.212.114.60]:1046 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757204AbYEXOqd (ORCPT ); Sat, 24 May 2008 10:46:33 -0400 Date: Sat, 24 May 2008 16:46:27 +0200 From: Willy Tarreau To: Jeremy Fitzhardinge Cc: Sam Ravnborg , "H. Peter Anvin" , Steve French , lkml Subject: Re: kernel coding style for if ... else which cross #ifdef Message-ID: <20080524144627.GB4166@1wt.eu> References: <524f69650805231211r315be4e4u5890aa0f914bcb4f@mail.gmail.com> <48374D3F.1080502@zytor.com> <20080524054301.GA3773@uranus.ravnborg.org> <4837AAE2.9090102@zytor.com> <20080524064201.GA4133@uranus.ravnborg.org> <4837E89D.9040008@goop.org> <20080524112704.GA7292@uranus.ravnborg.org> <483827CE.9080200@goop.org> <20080524143950.GG6749@1wt.eu> <48382911.8090807@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48382911.8090807@goop.org> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 24, 2008 at 03:41:21PM +0100, Jeremy Fitzhardinge wrote: > Willy Tarreau wrote: > >You still have the possibility to use the "-0" trick : > > > > if (CFG_THINGY_LIMIT && x > (CONFIG_THINGY_LIMIT-0)) {...} > > > > Oh, that's cute in a vile way. I hadn't seen it before. I use it in some of my code (but moderately). It's particularly useful for limit checking such as above. It's useful too when you want to use the config value as an offset or a bit shift. Eg: p = malloc(buf_size << (CONFIG_SHIFT-0)); Willy