From patchwork Wed Mar 16 14:41:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 8601231 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 820179FD4C for ; Wed, 16 Mar 2016 14:41:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C3A5320251 for ; Wed, 16 Mar 2016 14:41:55 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EAD6C20304 for ; Wed, 16 Mar 2016 14:41:48 +0000 (UTC) Received: from localhost ([::1]:56763 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agCdw-000477-5q for patchwork-qemu-devel@patchwork.kernel.org; Wed, 16 Mar 2016 10:41:48 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48162) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agCdc-0003z2-AO for qemu-devel@nongnu.org; Wed, 16 Mar 2016 10:41:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1agCdZ-0004Yz-42 for qemu-devel@nongnu.org; Wed, 16 Mar 2016 10:41:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37057) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agCdY-0004Yl-SP for qemu-devel@nongnu.org; Wed, 16 Mar 2016 10:41:25 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 47B068051A; Wed, 16 Mar 2016 14:41:24 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-49.ams2.redhat.com [10.36.116.49]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2GEfMam005628 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 16 Mar 2016 10:41:23 -0400 Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id A0B90303F90D; Wed, 16 Mar 2016 15:41:21 +0100 (CET) From: Markus Armbruster To: Eric Blake References: <1457571335-10938-1-git-send-email-eblake@redhat.com> <1457571335-10938-7-git-send-email-eblake@redhat.com> Date: Wed, 16 Mar 2016 15:41:21 +0100 In-Reply-To: <1457571335-10938-7-git-send-email-eblake@redhat.com> (Eric Blake's message of "Wed, 9 Mar 2016 17:55:27 -0700") Message-ID: <871t7ascxa.fsf@blackfin.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: qemu-devel@nongnu.org, Michael Roth Subject: Re: [Qemu-devel] [PATCH v5 06/14] qapi-event: Slightly shrink generated code X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Eric Blake writes: > Slightly rearrange the code in gen_event_send() for less generated > output, by initializing 'emit' sooner, deferring an assertion > to qdict_put_obj, and dropping a now-unused 'obj' local variable. > > While at it, document a FIXME related to the potential for a > compiler naming collision - if the user ever creates a QAPI event > whose name matches 'errp' or one of our local variables (like > 'emit'), we'll have to revisit how we generate functions to > avoid the problem. I think this should go into the next patch, where we actually fix the same collision in command marshallers. > |@@ -25,16 +25,13 @@ void qapi_event_send_acpi_device_ost(ACP > | { > | QDict *qmp; > | Error *err = NULL; > |- QMPEventFuncEmit emit; > |+ QMPEventFuncEmit emit = qmp_event_get_func_emit(); > | QmpOutputVisitor *qov; > | Visitor *v; > |- QObject *obj; > | > |- emit = qmp_event_get_func_emit(); > | if (!emit) { > | return; > | } > |- > | qmp = qmp_event_build_dict("ACPI_DEVICE_OST"); > | > | qov = qmp_output_visitor_new(); > |@@ -53,11 +50,7 @@ out_obj: > | if (err) { > | goto out; > | } > |- > |- obj = qmp_output_get_qobject(qov); > |- g_assert(obj); > |- > |- qdict_put_obj(qmp, "data", obj); > |+ qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov)); > | emit(QAPI_EVENT_ACPI_DEVICE_OST, qmp, &err); > | > | out: This is actually two separate simplifications. One is initializing emit instead of assigning to it: > |@@ -25,16 +25,13 @@ void qapi_event_send_acpi_device_ost(ACP > | { > | QDict *qmp; > | Error *err = NULL; > |- QMPEventFuncEmit emit; > |+ QMPEventFuncEmit emit = qmp_event_get_func_emit(); > | QmpOutputVisitor *qov; > | Visitor *v; > | QObject *obj; > | > |- emit = qmp_event_get_func_emit(); > | if (!emit) { > | return; > | } > |- > | qmp = qmp_event_build_dict("ACPI_DEVICE_OST"); > | > | qov = qmp_output_visitor_new(); I'm afraid I don't like it, because it separates qmp_event_get_func_emit() from its check. A more likable simplification would be dropping the indirection outright: emit is always monitor_qapi_event_queue(), except in test-qmp-event. That's a rather weak excuse for complicating things with an indirection. Let's not upset this series with it, though. The other simplification is burying the dead check of qmp_output_get_qobject()'s value: > |@@ -25,16 +25,13 @@ void qapi_event_send_acpi_device_ost(ACP > | { > | QDict *qmp; > | Error *err = NULL; > | QMPEventFuncEmit emit; > | QmpOutputVisitor *qov; > | Visitor *v; > |- QObject *obj; > | > | emit = qmp_event_get_func_emit(); > |@@ -53,11 +50,7 @@ out_obj: > | if (err) { > | goto out; > | } > |- > |- obj = qmp_output_get_qobject(qov); > |- g_assert(obj); > |- > |- qdict_put_obj(qmp, "data", obj); > |+ qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov)); > | emit(QAPI_EVENT_ACPI_DEVICE_OST, qmp, &err); > | > | out: Yes, please. Patch shrinks to just this: From bfaa962b04f5365289c46dadb0c078a13d52eae8 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 9 Mar 2016 17:55:27 -0700 Subject: [PATCH 06/14] qapi-event: Drop qmp_output_get_qobject() null check qmp_output_get_qobject() was changed never to return null some time ago, but the qapi_event_send_FOO() functions still check. Clean that up: |@@ -28,7 +28,6 @@ void qapi_event_send_acpi_device_ost(ACP | QMPEventFuncEmit emit; | QmpOutputVisitor *qov; | Visitor *v; |- QObject *obj; | | emit = qmp_event_get_func_emit(); | if (!emit) { |@@ -54,10 +53,7 @@ out_obj: | goto out; | } | |- obj = qmp_output_get_qobject(qov); |- g_assert(obj); |- |- qdict_put_obj(qmp, "data", obj); |+ qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov)); | emit(QAPI_EVENT_ACPI_DEVICE_OST, qmp, &err); | | out: Signed-off-by: Eric Blake --- scripts/qapi-event.py | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py index c03cb78..27af206 100644 --- a/scripts/qapi-event.py +++ b/scripts/qapi-event.py @@ -43,7 +43,6 @@ def gen_event_send(name, arg_type): ret += mcgen(''' QmpOutputVisitor *qov; Visitor *v; - QObject *obj; ''') @@ -77,10 +76,7 @@ out_obj: goto out; } - obj = qmp_output_get_qobject(qov); - g_assert(obj); - - qdict_put_obj(qmp, "data", obj); + qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov)); ''') ret += mcgen('''