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 D1704C433EF for ; Wed, 27 Oct 2021 16:28:28 +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 466CC60E73 for ; Wed, 27 Oct 2021 16:28:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 466CC60E73 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]:38444 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mflmt-0002vG-6v for qemu-devel@archiver.kernel.org; Wed, 27 Oct 2021 12:28:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36996) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mfl6E-0004hA-Sj for qemu-devel@nongnu.org; Wed, 27 Oct 2021 11:44:23 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:53998) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mfl6C-00041v-1n for qemu-devel@nongnu.org; Wed, 27 Oct 2021 11:44:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635349459; 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=5oFdOC3ZalCz3veMVdcJnzMZp0Zut3uOShm0YnMrNv0=; b=WWvVHz3xBFuRn5tHRLfEovRgE9m8QfLOwqX7lF8cvD+JsCqE2OypdXMvst//5/cIGA2IP1 7Fb+f1aqlGhV81R0F3pAhGrX6B32ukZWpsPYVvF7a3Sria6h7CtuIiXyONE4L/yAne7exz DwbVfaeXQCogV74uqJY45SiorMo00BA= 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-106-LVgQf6FANfiAtb3s8joV2A-1; Wed, 27 Oct 2021 11:44:16 -0400 X-MC-Unique: LVgQf6FANfiAtb3s8joV2A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 52792802B61; Wed, 27 Oct 2021 15:44:15 +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 82705196FA; Wed, 27 Oct 2021 15:44:08 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1DAC211380B8; Wed, 27 Oct 2021 17:44:07 +0200 (CEST) From: Markus Armbruster To: qemu-devel@nongnu.org Subject: [PULL 2/5] qapi: Enable enum member introspection to show more than name Date: Wed, 27 Oct 2021 17:44:04 +0200 Message-Id: <20211027154407.214122-3-armbru@redhat.com> In-Reply-To: <20211027154407.214122-1-armbru@redhat.com> References: <20211027154407.214122-1-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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=170.10.133.124; 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: John Snow , Eric Blake , Peter Krempa , richard.henderson@linaro.org 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. Deprecate @values in favour of @members. Since query-qmp-schema compatibility is pretty fundamental for management applications, an extended grace period is advised. Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Tested-by: Peter Krempa Acked-by: Peter Krempa Message-Id: <20211025042405.3762351-2-armbru@redhat.com> Reviewed-by: John Snow --- docs/about/deprecated.rst | 6 ++++++ docs/devel/qapi-code-gen.rst | 15 +++++++++++---- qapi/introspect.json | 25 +++++++++++++++++++++++-- scripts/qapi/introspect.py | 18 ++++++++++++++---- 4 files changed, 54 insertions(+), 10 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 0bed6ecb1d..be19317470 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -228,6 +228,12 @@ Use the more generic commands ``block-export-add`` and ``block-export-del`` instead. As part of this deprecation, where ``nbd-server-add`` used a single ``bitmap``, the new ``block-export-add`` uses a list of ``bitmaps``. +``query-qmp-schema`` return value member ``values`` (since 6.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +Member ``values`` in return value elements with meta-type ``enum`` is +deprecated. Use ``members`` instead. + System accelerators ------------------- 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..9683e884f8 100644 --- a/qapi/introspect.json +++ b/qapi/introspect.json @@ -142,14 +142,35 @@ # # 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. +# +# Features: +# @deprecated: Member @values is deprecated. Use @members instead. # # Values of this type are JSON string on the wire. # # Since: 2.5 ## { 'struct': 'SchemaInfoEnum', - 'data': { 'values': ['str'] } } + 'data': { 'members': [ 'SchemaInfoEnumMember' ], + 'values': { 'type': [ 'str' ], + 'features': [ 'deprecated' ] } } } + +## +# @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