From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-2.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 0736320A28 for ; Wed, 20 Sep 2017 17:31:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751605AbdITRbj (ORCPT ); Wed, 20 Sep 2017 13:31:39 -0400 Received: from mail-pg0-f44.google.com ([74.125.83.44]:47050 "EHLO mail-pg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751589AbdITRbi (ORCPT ); Wed, 20 Sep 2017 13:31:38 -0400 Received: by mail-pg0-f44.google.com with SMTP id i130so2062129pgc.3 for ; Wed, 20 Sep 2017 10:31:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=DQ93ir3piaa1jCiVLXHu6Fg+VP5bJMluWdtGMrtghV8=; b=cuywLlCIAjdsdR8p1NVvW59WFj5jojX2dF98wEYVoXqitrAz7r5lzEPKEOdZDyNxLY kZXj3xraJLBu2tmbDk1Pvry9JEGO7XE5D57KhwEJP1OIwJjmOdE11UDz9ZPJIwi3KjJd UeJgLZEzbI3e3iXtY+23UPgoyyJBzBuxJBh5uw/Pns+GnjR0jQtPFk10Fmf3QMEOWm6t Ydwh4q7t4hEgiQu5NXQ2et7eQ673RbrOMP54Iv0CJDlVCoLFKNqjBFTKJGjniOxq8O4z 1ERZsQeEoQK28trUDhMUwC4Uh2ZY0byT1Ta7b3/IzPCWN2rShHAuZyLzFC+82ZWiDG3c SoEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=DQ93ir3piaa1jCiVLXHu6Fg+VP5bJMluWdtGMrtghV8=; b=eqmiTk1P3VzPgeIVq7cN7rtIfZVPHDNjpEbWEYTRAnu1Xl69MVfZGiPw/X1WkGfQaA TDSpfuAD8jz5D0dtpMebO3h/GwpsxiXpp6Q59QgeyQyCnSBdJ435QAVdPonskcdkgdav OUFjHaCxgOM0l5llgBwKknR5fHMGyzMbcV/9F+8sfjonv5Z9Y9vhqa0g9cXw4oW/FVpR e833nEK6J86MrznsaGYjENwQFUKhYUEmRfdSm145xMwZQxXnmZCYl5jV81j587bcgh6q LYWti4FniPd8yz2ahINTRFFsn8Wz5Q/QwyhdHR28m16SIRjayV7yHqo/Pv+7khz37aON JbRA== X-Gm-Message-State: AHPjjUgZCa5t2oXLTpffCWPhLCJEnLP3Wrt95eOoFn6uUb1ZlXzSdojv hmbj8VXq0kakf+sKT1z8WaVF0DMV X-Google-Smtp-Source: AOwi7QBlLhSy6ZplXdVK1hXTj5q1hC84O7G+bX+J9bQGJiuDwWL+zKQRJytFT0XTXDrM8sa6IXjENA== X-Received: by 10.84.176.65 with SMTP id u59mr2835902plb.278.1505928698046; Wed, 20 Sep 2017 10:31:38 -0700 (PDT) Received: from aiede.mtv.corp.google.com ([2620:0:100e:422:da9:ac38:cdcf:de91]) by smtp.gmail.com with ESMTPSA id r90sm9537384pfb.183.2017.09.20.10.31.36 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Wed, 20 Sep 2017 10:31:36 -0700 (PDT) Date: Wed, 20 Sep 2017 10:31:34 -0700 From: Jonathan Nieder To: Andreas Schwab Cc: Junio C Hamano , Kaartic Sivaraam , Michael Haggerty , Alex Riesen , git@vger.kernel.org Subject: Re: [PATCH v2] for_each_string_list_item: avoid undefined behavior for empty list Message-ID: <20170920173134.GZ27425@aiede.mtv.corp.google.com> References: <20170915184323.GU27425@aiede.mtv.corp.google.com> <20170920023008.GB126984@aiede.mtv.corp.google.com> <20170920052705.GC126984@aiede.mtv.corp.google.com> <87vakd2v22.fsf@linux-m68k.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87vakd2v22.fsf@linux-m68k.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Andreas Schwab wrote: > On Sep 19 2017, Jonathan Nieder wrote: >> B. #define for_each_string_list_item(item, list) \ >> if (list->items) \ >> for (item = ...; ...; ... ) >> >> This breaks a caller like >> if (foo) >> for_each_string_list_item(item, list) >> ... >> else >> ... >> >> making it a non-starter. > > That can be fixed with a dangling else. I believe the fix you're referring to is option C, from the same email you are replying to. If not, please correct me. Thanks, Jonathan