From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1NkLz1-0004iQ-LO
	for qemu-devel@nongnu.org; Wed, 24 Feb 2010 13:29:15 -0500
Received: from [199.232.76.173] (port=57214 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1NkLz0-0004h6-U1
	for qemu-devel@nongnu.org; Wed, 24 Feb 2010 13:29:14 -0500
Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim
	4.60) (envelope-from <weil@mail.berlios.de>) id 1NkLyx-0003Xx-Q1
	for qemu-devel@nongnu.org; Wed, 24 Feb 2010 13:29:14 -0500
Received: from moutng.kundenserver.de ([212.227.17.9]:53866)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <weil@mail.berlios.de>) id 1NkLyx-0003Xi-7U
	for qemu-devel@nongnu.org; Wed, 24 Feb 2010 13:29:11 -0500
Message-ID: <4B856FF2.3050703@mail.berlios.de>
Date: Wed, 24 Feb 2010 19:29:06 +0100
From: Stefan Weil <weil@mail.berlios.de>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [RFC] Don't send local debug output to stdout
References: <1262745591-28697-1-git-send-email-yamahata@valinux.co.jp>
	<20100106235113.GE29412@valinux.co.jp>
	<4B53363C.8060906@mail.berlios.de>
	<201002240228.31814.paul@codesourcery.com>
In-Reply-To: <201002240228.31814.paul@codesourcery.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
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: Paul Brook <paul@codesourcery.com>
Cc: qemu-devel@nongnu.org, Isaku Yamahata <yamahata@valinux.co.jp>

Paul Brook schrieb:
>> I suggest these steps:
>>
>> 1. Debug output to stdout is no longer accepted for new / modified code.
>>
>> 2. New or modified debug messages should go to stderr.
>
> I don't see this as a real improvement. Arguably these aren't errors, so
> stdout is where they should be going.
>
> If we're going to do anything sensible with debug output then we
> should figure
> out how to do it properly and consistently. Also remember that this isn't
> supposed to be user friendly, it's for internal developer use only.
>
> Paul

stdout is already used by curses or serial console output
when QEMU is called with appropriate command line switches.

If debugging output also goes to stdout, program output and
debugging output are mixed which can make both completely
unreadable.

Just consider debug output from the serial driver (or any other
device which works parallel to the normal program output).
I was already confronted with this problem.

My proposal is easy to implement and sufficient for internal
developer use. It is not new: parts of QEMU already use
stderr for debugging output. Of course better solutions exist,
but they also need more efforts.

Stefan