From patchwork Tue Dec 8 03:55:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 553770 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 1693C1402C9 for ; Tue, 8 Dec 2015 15:05:09 +1100 (AEDT) Received: from localhost ([::1]:57740 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a69WU-0004Mk-KB for incoming@patchwork.ozlabs.org; Mon, 07 Dec 2015 23:05:06 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48295) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a69NO-0004a3-MS for qemu-devel@nongnu.org; Mon, 07 Dec 2015 22:55:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a69NN-0003eZ-FY for qemu-devel@nongnu.org; Mon, 07 Dec 2015 22:55:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45676) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a69NN-0003eG-7k for qemu-devel@nongnu.org; Mon, 07 Dec 2015 22:55:41 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id BA5DD461C4; Tue, 8 Dec 2015 03:55:40 +0000 (UTC) Received: from red.redhat.com (ovpn-113-183.phx2.redhat.com [10.3.113.183]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tB83tOMD007883; Mon, 7 Dec 2015 22:55:40 -0500 From: Eric Blake To: qemu-devel@nongnu.org Date: Mon, 7 Dec 2015 20:55:14 -0700 Message-Id: <1449546921-6378-25-git-send-email-eblake@redhat.com> In-Reply-To: <1449546921-6378-1-git-send-email-eblake@redhat.com> References: <1449546921-6378-1-git-send-email-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: armbru@redhat.com, Michael Roth Subject: [Qemu-devel] [PATCH v7 24/31] qapi: Eliminate empty visit_type_FOO_fields 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org For empty structs, such as the 'Abort' helper type used as part of the 'transaction' command, we were emitting a no-op visit_type_FOO_fields(). Optimize things to instead omit calls for empty structs. Generated code changes resemble: |-static void visit_type_Abort_fields(Visitor *v, Abort **obj, Error **errp) |-{ |- Error *err = NULL; |- |- error_propagate(errp, err); |-} |- | void visit_type_Abort(Visitor *v, Abort **obj, const char *name, Error **errp) | { | Error *err = NULL; |@@ -112,7 +105,6 @@ void visit_type_Abort(Visitor *v, Abort | if (!*obj) { | goto out_obj; | } |- visit_type_Abort_fields(v, obj, &err); | out_obj: | error_propagate(errp, err); Another reason for doing this optimization is that it gets us closer to merging the code for visiting structs and unions: since flat unions have no local members, they do not need to have a visit_type_UNION_fields() emitted, even when they start sharing the code used to visit structs. Signed-off-by: Eric Blake --- v7: rebase to earlier changes v6: new patch --- scripts/qapi-visit.py | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-) diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py index acb237b..4ec0d22 100644 --- a/scripts/qapi-visit.py +++ b/scripts/qapi-visit.py @@ -35,22 +35,22 @@ void visit_type_%(c_name)s(Visitor *v, %(c_type)sobj, const char *name, Error ** def gen_visit_fields_decl(typ): - ret = '' - if typ.name not in struct_fields_seen: - ret += mcgen(''' + if typ.is_empty() or typ.name in struct_fields_seen: + return '' + + struct_fields_seen.add(typ.name) + return mcgen(''' static void visit_type_%(c_type)s_fields(Visitor *v, %(c_type)s **obj, Error **errp); ''', - c_type=typ.c_name()) - struct_fields_seen.add(typ.name) - return ret + c_type=typ.c_name()) def gen_visit_implicit_struct(typ): - if typ in implicit_structs_seen: + if typ.is_empty() or typ in implicit_structs_seen: return '' + implicit_structs_seen.add(typ) - ret = gen_visit_fields_decl(typ) ret += mcgen(''' @@ -74,7 +74,10 @@ static void visit_type_implicit_%(c_type)s(Visitor *v, %(c_type)s **obj, Error * def gen_visit_struct_fields(name, base, members): ret = '' - if base: + if (not base or base.is_empty()) and not members: + return ret + + if base and not base.is_empty(): ret += gen_visit_fields_decl(base) struct_fields_seen.add(name) @@ -87,7 +90,7 @@ static void visit_type_%(c_name)s_fields(Visitor *v, %(c_name)s **obj, Error **e ''', c_name=c_name(name)) - if base: + if base and not base.is_empty(): ret += mcgen(''' visit_type_%(c_type)s_fields(v, (%(c_type)s **)obj, &err); ''', @@ -96,13 +99,9 @@ static void visit_type_%(c_name)s_fields(Visitor *v, %(c_name)s **obj, Error **e ret += gen_visit_fields(members, prefix='(*obj)->') - # 'goto out' produced for base, and by gen_visit_fields() for each member - if base or members: - ret += mcgen(''' + ret += mcgen(''' out: -''') - ret += mcgen(''' error_propagate(errp, err); } ''') @@ -129,7 +128,14 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error if (!*obj) { goto out_obj; } +''', + name=name, c_name=c_name(name)) + if (base and not base.is_empty()) or members: + ret += mcgen(''' visit_type_%(c_name)s_fields(v, obj, &err); +''', + c_name=c_name(name)) + ret += mcgen(''' out_obj: error_propagate(errp, err); err = NULL; @@ -137,8 +143,7 @@ out_obj: out: error_propagate(errp, err); } -''', - c_name=c_name(name)) +''') return ret @@ -300,7 +305,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error ''', c_type=simple_union_type.c_name(), c_name=c_name(var.name)) - else: + elif not var.type.is_empty(): ret += mcgen(''' visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err); ''',