Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932593AbWHAJj2 (ORCPT ); Tue, 1 Aug 2006 05:39:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932597AbWHAJj2 (ORCPT ); Tue, 1 Aug 2006 05:39:28 -0400 Received: from amsfep17-int.chello.nl ([213.46.243.15]:61454 "EHLO amsfep14-int.chello.nl") by vger.kernel.org with ESMTP id S932593AbWHAJj1 (ORCPT ); Tue, 1 Aug 2006 05:39:27 -0400 Subject: RE: do { } while (0) question From: Peter Zijlstra To: Hua Zhong Cc: "'Jiri Slaby'" , "'Heiko Carstens'" , "'Andrew Morton'" , linux-kernel@vger.kernel.org, "'Martin Schwidefsky'" In-Reply-To: <008e01c6b549$59e52f70$493d010a@nuitysystems.com> References: <008e01c6b549$59e52f70$493d010a@nuitysystems.com> Content-Type: text/plain Date: Tue, 01 Aug 2006 11:39:31 +0200 Message-Id: <1154425171.32739.2.camel@taijtu> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 (2.6.2-1.fc5.5) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 712 Lines: 28 On Tue, 2006-08-01 at 02:03 -0700, Hua Zhong wrote: > > #if KILLER == 1 > > #define MACRO > > #else > > #define MACRO do { } while (0) > > #endif > > > > { > > if (some_condition) > > MACRO > > > > if_this_is_not_called_you_loose_your_data(); > > } > > > > How do you want to define KILLER, 0 or 1? I personally choose 0. > > Really? Does it compile? No, and that is the whole point. The empty 'do {} while (0)' makes the missing semicolon a syntax error. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/