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 X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7457C2D0E4 for ; Thu, 12 Nov 2020 18:36:13 +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 48BBA22227 for ; Thu, 12 Nov 2020 18:36:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WzVL1ue1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 48BBA22227 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35666 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kdHS8-0008Ss-4l for qemu-devel@archiver.kernel.org; Thu, 12 Nov 2020 13:36:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47564) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kdHQU-0006aT-WF for qemu-devel@nongnu.org; Thu, 12 Nov 2020 13:34:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:48350) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kdHQP-0004wY-MB for qemu-devel@nongnu.org; Thu, 12 Nov 2020 13:34:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605206063; 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=5AUUXLKYqRyZ5SWmURW/hhF3LKFrydNZvRSAuYLFBac=; b=WzVL1ue16JPESJdjDU0VHumibQFLw18PYMcNLH5ueX6dCdZBrTnNOQ0CZrC1lJpk0yJcXv ypPYYROdGo3or7WQGEIuX85GGupUtXwn3bt5dU0DnECFabQwbN+xmlA3HOwEAtz/dV9mQ2 Zr14IdiX1wEhZy1B7TJpJtbFGK/GOHs= 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-366-QCqRdEqWPtGOF-K0vqXlLA-1; Thu, 12 Nov 2020 13:34:21 -0500 X-MC-Unique: QCqRdEqWPtGOF-K0vqXlLA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DE1978BE487 for ; Thu, 12 Nov 2020 18:34:20 +0000 (UTC) Received: from [10.3.113.51] (ovpn-113-51.phx2.redhat.com [10.3.113.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8D23960C0F; Thu, 12 Nov 2020 18:34:20 +0000 (UTC) Subject: Re: [PATCH 5/6] qapi: Add support for aliases To: Kevin Wolf , qemu-devel@nongnu.org References: <20201112172850.401925-1-kwolf@redhat.com> <20201112172850.401925-6-kwolf@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <7864bd70-5567-134f-9238-bbed8a5fbfdb@redhat.com> Date: Thu, 12 Nov 2020 12:34:19 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201112172850.401925-6-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/12 00:52:29 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=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: jsnow@redhat.com, armbru@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 11/12/20 11:28 AM, Kevin Wolf wrote: > Introduce alias definitions for object types (structs and unions). This > allows using the same QAPI type and visitor for many syntax variations > that exist in the external representation, like between QMP and the > command line. It also provides a new tool for evolving the schema while > maintaining backwards compatibility during a deprecation period. Cool! Obvious followup patch series: deprecate all QAPI members spelled with _ by making them aliases of new members spelled with -, so that we can finally have consistent spellings. > +=== Aliases === > + > +Object types, including structs and unions, can contain alias > +definitions. > + > +Aliases define alternative member names that may be used in the > +external representation to provide a value for a member in the same > +object or in a nested object. > + > +Syntax: > + ALIAS = { '*alias': STRING, > + 'source': [ STRING, ... ] } > + > +'source' is a list of member names representing the path to an object > +member, starting from the type where the alias definition is > +specified. It may refer to another alias name. It is allowed to use > +a path that doesn't necessarily match an existing member in every > +variant or even at all; in this case, the alias remains unused. > + > +If 'alias' is present, then the single member referred to by 'source' > +is made accessible with the name given in 'alias' in the type where > +the alias definition is specified. > + > +If 'alias' is not present, then all members in the object referred to > +by 'source' are made accessible in the type where the alias definition > +is specified with the same name as they have in 'source'. Is it worth an example of how to use this? -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org