From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C110C433F5 for ; Thu, 21 Oct 2021 10:29:08 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B57606112D for ; Thu, 21 Oct 2021 10:29:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B57606112D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:55864 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mdVJq-0003XP-To for qemu-devel@archiver.kernel.org; Thu, 21 Oct 2021 06:29:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59388) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mdVBy-00039O-2J for qemu-devel@nongnu.org; Thu, 21 Oct 2021 06:20:58 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38453) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mdVBs-0002eZ-6B for qemu-devel@nongnu.org; Thu, 21 Oct 2021 06:20:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634811650; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TZP6NgMdeef/0HC5IsTFCrbdKpBXASKvnSPRcCeD2lE=; b=aFINhvCOobwyW0hhr+VCvPhoIKCT+nDBBUTZnPZ8ViP4sGhyXjR6SHAYCdtJP4PrH53A7Q PtZJVkB9zl/UH3pTLd4/MWkERGnXm5XUxvSQPcrRejY/f4bMRSBELXakDN5u/ANM6/SSbN 8Dubnox9AOf6gkJz7KNWhHbARoRT5TI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-365-gln-qFGkMrySKnrfTn0iLA-1; Thu, 21 Oct 2021 06:20:31 -0400 X-MC-Unique: gln-qFGkMrySKnrfTn0iLA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0605E10A8E03; Thu, 21 Oct 2021 10:20:30 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-7.ams2.redhat.com [10.36.112.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EE81579447; Thu, 21 Oct 2021 10:20:02 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 59B8911380AA; Thu, 21 Oct 2021 12:20:01 +0200 (CEST) From: Markus Armbruster To: qemu-devel@nongnu.org Subject: [PATCH v3 1/5] qapi: Enable enum member introspection to show more than name Date: Thu, 21 Oct 2021 12:19:57 +0200 Message-Id: <20211021102001.803780-2-armbru@redhat.com> In-Reply-To: <20211021102001.803780-1-armbru@redhat.com> References: <20211021102001.803780-1-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, berrange@redhat.com, libvir-list@redhat.com, eblake@redhat.com, mdroth@linux.vnet.ibm.com, pkrempa@redhat.com, marcandre.lureau@redhat.com, jsnow@redhat.com, libguestfs@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The next commit will add feature flags to enum members. There's a problem, though: query-qmp-schema shows an enum type's members as an array of member names (SchemaInfoEnum member @values). If it showed an array of objects with a name member, we could simply add more members to these objects. Since it's just strings, we can't. I can see three ways to correct this design mistake: 1. Do it the way we should have done it, plus compatibility goo. We want a ['SchemaInfoEnumMember'] member in SchemaInfoEnum. Since changing @values would be a compatibility break, add a new member @members instead. @values is now redundant. In my testing, output of qemu-system-x86_64's query-qmp-schema grows by 11% (18.5KiB). We can deprecate @values now and drop it later. This will break outmoded clients. Well-behaved clients such as libvirt are expected to break cleanly. 2. Like 1, but omit "boring" elements of @member, and empty @member. @values does not become redundant. @members augments it. Somewhat cumbersome, but output of query-qmp-schema grows only as we make enum members non-boring. There is nothing to deprecate here. 3. Versioned query-qmp-schema. query-qmp-schema provides either @values or @members. The QMP client can select which version it wants. There is no redundant output. We can deprecate old versions and eventually drop them. This will break outmoded clients. Breaking cleanly is easier than for 1. While 1 and 2 operate within the common rules for compatible evolution apply (section "Compatibility considerations" in docs/devel/qapi-code-gen.rst), 3 bypasses them. Attractive when operating within the rules is just too awkward. Not the case here. This commit implements 1. Libvirt developers prefer it. Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Tested-by: Peter Krempa Acked-by: Peter Krempa --- docs/devel/qapi-code-gen.rst | 15 +++++++++++---- qapi/introspect.json | 21 +++++++++++++++++++-- scripts/qapi/introspect.py | 18 ++++++++++++++---- 3 files changed, 44 insertions(+), 10 deletions(-) diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst index b2569de486..d267889d2c 100644 --- a/docs/devel/qapi-code-gen.rst +++ b/docs/devel/qapi-code-gen.rst @@ -1231,14 +1231,21 @@ Example: the SchemaInfo for ['str'] :: "element-type": "str" } The SchemaInfo for an enumeration type has meta-type "enum" and -variant member "values". The values are listed in no particular -order; clients must search the entire enum when learning whether a -particular value is supported. +variant member "members". + +"members" is a JSON array describing the enumeration values. Each +element is a JSON object with member "name" (the member's name). The +"members" array is in no particular order; clients must search the +entire array when learning whether a particular value is supported. Example: the SchemaInfo for MyEnum from section `Enumeration types`_ :: { "name": "MyEnum", "meta-type": "enum", - "values": [ "value1", "value2", "value3" ] } + "members": [ + { "name": "value1" }, + { "name": "value2" }, + { "name": "value3" } + ] } The SchemaInfo for a built-in type has the same name as the type in the QAPI schema (see section `Built-in Types`_), with one exception diff --git a/qapi/introspect.json b/qapi/introspect.json index 39bd303778..f806bd7281 100644 --- a/qapi/introspect.json +++ b/qapi/introspect.json @@ -142,14 +142,31 @@ # # Additional SchemaInfo members for meta-type 'enum'. # -# @values: the enumeration type's values, in no particular order. +# @members: the enum type's members, in no particular order +# (since 6.2). +# +# @values: the enumeration type's member names, in no particular order. +# Redundant with @members. Just for backward compatibility. # # Values of this type are JSON string on the wire. # # Since: 2.5 ## { 'struct': 'SchemaInfoEnum', - 'data': { 'values': ['str'] } } + 'data': { 'members': [ 'SchemaInfoEnumMember' ], + 'values': ['str'] } } + +## +# @SchemaInfoEnumMember: +# +# An object member. +# +# @name: the member's name, as defined in the QAPI schema. +# +# Since: 6.2 +## +{ 'struct': 'SchemaInfoEnumMember', + 'data': { 'name': 'str' } } ## # @SchemaInfoArray: diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py index 4c079ee627..6334546363 100644 --- a/scripts/qapi/introspect.py +++ b/scripts/qapi/introspect.py @@ -68,6 +68,7 @@ # TypedDict constructs, so they are broadly typed here as simple # Python Dicts. SchemaInfo = Dict[str, object] +SchemaInfoEnumMember = Dict[str, object] SchemaInfoObject = Dict[str, object] SchemaInfoObjectVariant = Dict[str, object] SchemaInfoObjectMember = Dict[str, object] @@ -274,8 +275,16 @@ def _gen_tree(self, name: str, mtype: str, obj: Dict[str, object], obj['features'] = self._gen_features(features) self._trees.append(Annotated(obj, ifcond, comment)) - def _gen_member(self, member: QAPISchemaObjectTypeMember - ) -> Annotated[SchemaInfoObjectMember]: + @staticmethod + def _gen_enum_member(member: QAPISchemaEnumMember + ) -> Annotated[SchemaInfoEnumMember]: + obj: SchemaInfoEnumMember = { + 'name': member.name, + } + return Annotated(obj, member.ifcond) + + def _gen_object_member(self, member: QAPISchemaObjectTypeMember + ) -> Annotated[SchemaInfoObjectMember]: obj: SchemaInfoObjectMember = { 'name': member.name, 'type': self._use_type(member.type) @@ -305,7 +314,8 @@ def visit_enum_type(self, name: str, info: Optional[QAPISourceInfo], prefix: Optional[str]) -> None: self._gen_tree( name, 'enum', - {'values': [Annotated(m.name, m.ifcond) for m in members]}, + {'members': [self._gen_enum_member(m) for m in members], + 'values': [Annotated(m.name, m.ifcond) for m in members]}, ifcond, features ) @@ -322,7 +332,7 @@ def visit_object_type_flat(self, name: str, info: Optional[QAPISourceInfo], members: List[QAPISchemaObjectTypeMember], variants: Optional[QAPISchemaVariants]) -> None: obj: SchemaInfoObject = { - 'members': [self._gen_member(m) for m in members] + 'members': [self._gen_object_member(m) for m in members] } if variants: obj['tag'] = variants.tag_member.name -- 2.31.1