From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1L2qEg-00079U-2E
	for qemu-devel@nongnu.org; Wed, 19 Nov 2008 11:49:02 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1L2qEe-00078c-4F
	for qemu-devel@nongnu.org; Wed, 19 Nov 2008 11:49:01 -0500
Received: from [199.232.76.173] (port=57877 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1L2qEe-00078V-0O
	for qemu-devel@nongnu.org; Wed, 19 Nov 2008 11:49:00 -0500
Received: from gv-out-0910.google.com ([216.239.58.186]:52249)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <anthony@codemonkey.ws>) id 1L2qEd-00074m-MI
	for qemu-devel@nongnu.org; Wed, 19 Nov 2008 11:48:59 -0500
Received: by gv-out-0910.google.com with SMTP id n8so25605gve.36
	for <qemu-devel@nongnu.org>; Wed, 19 Nov 2008 08:48:58 -0800 (PST)
Message-ID: <49244376.7020009@codemonkey.ws>
Date: Wed, 19 Nov 2008 10:48:54 -0600
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] Re: [PATCH 1/2] Add TAILQ_FOREACH_SAFE
References: <20081119134857.26075.2417.stgit@mchn012c.ww002.siemens.net>	<20081119134857.26075.9428.stgit@mchn012c.ww002.siemens.net>	<492429F3.3010202@codemonkey.ws>
	<492435B9.3010106@siemens.com>
In-Reply-To: <492435B9.3010106@siemens.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org

Jan Kiszka wrote:
> Won't fly, next_var can become NULL and would be dereferenced without a
> prior check. Unless I'm totally blind now, there is no
> TAILQ_FOREACH_SAFE without "GCC-ism"

Wouldn't:

(var) ? ({ (next_var) = ((var)->field.tqe_next); 1;}) :0;

Be equivalent to:

(var) ? ((next_var = ((var)->field.tqe_next), var) : var

Regards,

Anthony Liguori