From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1NnINL-0007fa-W1
	for qemu-devel@nongnu.org; Thu, 04 Mar 2010 16:14:32 -0500
Received: from [199.232.76.173] (port=60853 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1NnINL-0007fQ-L0
	for qemu-devel@nongnu.org; Thu, 04 Mar 2010 16:14:31 -0500
Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim
	4.60) (envelope-from <lcapitulino@redhat.com>) id 1NnINK-0000wy-3m
	for qemu-devel@nongnu.org; Thu, 04 Mar 2010 16:14:31 -0500
Received: from mx1.redhat.com ([209.132.183.28]:5027)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <lcapitulino@redhat.com>) id 1NnINJ-0000wj-N1
	for qemu-devel@nongnu.org; Thu, 04 Mar 2010 16:14:29 -0500
Received: from int-mx05.intmail.prod.int.phx2.redhat.com
	(int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.18])
	by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o24LESpU014238
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK)
	for <qemu-devel@nongnu.org>; Thu, 4 Mar 2010 16:14:29 -0500
Date: Thu, 4 Mar 2010 18:14:22 -0300
From: Luiz Capitulino <lcapitulino@redhat.com>
Message-ID: <20100304181422.42bc23ce@redhat.com>
In-Reply-To: <m3pr3jn6e5.fsf@blackfin.pond.sub.org>
References: <1267718231-13303-1-git-send-email-armbru@redhat.com>
	<1267718231-13303-29-git-send-email-armbru@redhat.com>
	<20100304175020.67e8de5a@redhat.com>
	<m3pr3jn6e5.fsf@blackfin.pond.sub.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Subject: [Qemu-devel] Re: [PATCH 28/50] error: Let converted handlers print
 in human monitor
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: Markus Armbruster <armbru@redhat.com>
Cc: qemu-devel@nongnu.org

On Thu, 04 Mar 2010 22:06:42 +0100
Markus Armbruster <armbru@redhat.com> wrote:

> Luiz Capitulino <lcapitulino@redhat.com> writes:
> 
> > On Thu,  4 Mar 2010 16:56:49 +0100
> > Markus Armbruster <armbru@redhat.com> wrote:
> >
> >> While fully converted handlers are not supposed to print anything when
> >> running in a QMP monitor, they are free to print in a human monitor.
> >
> >  I disagree.
> >
> >  One of the key decisions behind the new Monitor design is that handlers
> > are part of common code. User printing is output-specific and should not
> > be done by handlers.
> >
> >  One of the problems with this layer violation is that the consumer of this
> > data might not be what you have assumed. For example, it has been suggested
> > that we could move the qemu shell out of qemu in the future. In this case,
> > this kind of information _could_ be useful.
> 
> How do you intend to solve the problem of printing help then?

 Doesn't a shallow conversion takes care of it for now?

> The perfect is the enemy of the good.
> 
> >  Another important problem is that free printing like this is error-prone
> > as it's not at all clear what could be printed and there's no way to catch
> > mistakes mechanically. Not to mention that this is for sure going to used
> > by those who want to ignore QMP completely.
> 
> This paragraph I don't get.

 If something that should be available under qmp is printed by using
monitor_printf(), we loose big time.