From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59559) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e09hE-0000Fm-Gi for qemu-devel@nongnu.org; Thu, 05 Oct 2017 13:12:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e09go-0001JR-88 for qemu-devel@nongnu.org; Thu, 05 Oct 2017 13:12:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60720) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e09gn-0001I0-Uj for qemu-devel@nongnu.org; Thu, 05 Oct 2017 13:12:02 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D0B65780CE for ; Thu, 5 Oct 2017 17:12:00 +0000 (UTC) Date: Thu, 5 Oct 2017 14:11:59 -0300 From: Eduardo Habkost Message-ID: <20171005171159.GG4015@localhost.localdomain> References: <1507206738-816-1-git-send-email-thuth@redhat.com> <1507206738-816-2-git-send-email-thuth@redhat.com> <20171005155912.5871c4d7@nial.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171005155912.5871c4d7@nial.brq.redhat.com> Subject: Re: [Qemu-devel] [PATCH 1/2] qdev_monitor: Simplify error handling in qdev_device_add() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: Thomas Huth , qemu-devel@nongnu.org, Markus Armbruster , "Dr. David Alan Gilbert" , Paolo Bonzini On Thu, Oct 05, 2017 at 03:59:12PM +0200, Igor Mammedov wrote: > On Thu, 5 Oct 2017 14:32:17 +0200 > Thomas Huth wrote: > > > Instead of doing the clean-ups on errors multiple times, introduce > > a jump label at the end of the function that can be used by all > > error paths that need this cleanup. > > > > Suggested-by: Igor Mammedov > > Signed-off-by: Thomas Huth > > --- > > qdev-monitor.c | 21 ++++++++++----------- > > 1 file changed, 10 insertions(+), 11 deletions(-) > > > > diff --git a/qdev-monitor.c b/qdev-monitor.c > > index 8fd6df9..cb2b109 100644 > > --- a/qdev-monitor.c > > +++ b/qdev-monitor.c > > @@ -620,22 +620,21 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) > > > > /* set properties */ > > if (qemu_opt_foreach(opts, set_property, dev, &err)) { > > - error_propagate(errp, err); > > - object_unparent(OBJECT(dev)); > > - object_unref(OBJECT(dev)); > > - return NULL; > > + goto err_del_dev; > > } > > > > dev->opts = opts; > > object_property_set_bool(OBJECT(dev), true, "realized", &err); > > - if (err != NULL) { > > - error_propagate(errp, err); > > - dev->opts = NULL; > > - object_unparent(OBJECT(dev)); > > - object_unref(OBJECT(dev)); > > - return NULL; > > + if (!err) { > > + return dev; > > } > typically the same error check pattern is used through out the function > so I'd not do inversion here. i.e. keep normal flow non-branched and jump on error > > if (err != NULL) { > goto err_del_dev; > } > return dev; > > err_del_dev: > dev->opts = NULL; I prefer this pattern also. It makes the success/error paths very easy to spot. -- Eduardo