From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51555) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aB3xH-0007Cf-BI for qemu-devel@nongnu.org; Mon, 21 Dec 2015 12:09:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aB3xF-0006eS-Vn for qemu-devel@nongnu.org; Mon, 21 Dec 2015 12:09:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56153) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aB3xF-0006eC-Nk for qemu-devel@nongnu.org; Mon, 21 Dec 2015 12:09:01 -0500 From: Eric Blake Date: Mon, 21 Dec 2015 10:08:33 -0700 Message-Id: <1450717720-9627-29-git-send-email-eblake@redhat.com> In-Reply-To: <1450717720-9627-1-git-send-email-eblake@redhat.com> References: <1450717720-9627-1-git-send-email-eblake@redhat.com> Subject: [Qemu-devel] [PATCH v8 28/35] qapi: Eliminate empty visit_type_FOO_fields List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: armbru@redhat.com, Michael Roth 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, const char *name, Abort **obj, 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 --- v8: rebase to earlier changes 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 573bb81..6537a20 100644 --- a/scripts/qapi-visit.py +++ b/scripts/qapi-visit.py @@ -35,22 +35,22 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, 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, const char *name, %(c_name)s **obj, 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, const char *name, %(c_name)s **obj, 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); ''', -- 2.4.3