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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id CC7CEE732D0 for ; Thu, 28 Sep 2023 14:07:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qlrf9-0003eQ-DP; Thu, 28 Sep 2023 10:06:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qlrf5-0003cc-P7 for qemu-devel@nongnu.org; Thu, 28 Sep 2023 10:06:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qlrez-0002cE-7H for qemu-devel@nongnu.org; Thu, 28 Sep 2023 10:06:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695909992; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=9C/+oS5CuncPrWl41i7hc4i1uFeOeN+qLl55hB00wck=; b=MHd2CEGh4TBQpDGh2uTYXNvIf6ufkgz7PPgKR3Uo09GYb2e208/ZyFgF4MNNEeAAigT2LT kCWYmGLvFTqg3jFCzelMzOvgpTlzFeA7G4o3Ol3a8EAG6g4IuAsqagSQSaueSM6TXmsVmA wVMcoXYS9QE/z6CYpJuhgX8lsA8xImQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-141-g2dM5xNNNT-bgHWaAow4-w-1; Thu, 28 Sep 2023 10:06:30 -0400 X-MC-Unique: g2dM5xNNNT-bgHWaAow4-w-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1B477185A78E for ; Thu, 28 Sep 2023 14:06:30 +0000 (UTC) Received: from redhat.com (unknown [10.39.194.58]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B749614171B6; Thu, 28 Sep 2023 14:06:28 +0000 (UTC) Date: Thu, 28 Sep 2023 15:06:23 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Victor Toso Cc: qemu-devel@nongnu.org, Markus Armbruster , John Snow Subject: Re: [PATCH v1 3/9] qapi: golang: Generate qapi's struct types in Go Message-ID: References: <20230927112544.85011-1-victortoso@redhat.com> <20230927112544.85011-4-victortoso@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230927112544.85011-4-victortoso@redhat.com> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Sep 27, 2023 at 01:25:38PM +0200, Victor Toso wrote: > This patch handles QAPI struct types and generates the equivalent > types in Go. The following patch adds extra logic when a member of the > struct has a Type that can take JSON Null value (e.g: StrOrNull in > QEMU) > > The highlights of this implementation are: > > 1. Generating an Go struct that requires a @base type, the @base type > fields are copied over to the Go struct. The advantage of this > approach is to not have embed structs in any of the QAPI types. > Note that embedding a @base type is recursive, that is, if the > @base type has a @base, all of those fields will be copied over. > > 2. About the Go struct's fields: > > i) They can be either by Value or Reference. > > ii) Every field that is marked as optional in the QAPI specification > are translated to Reference fields in its Go structure. This > design decision is the most straightforward way to check if a > given field was set or not. Exception only for types that can > take JSON Null value. > > iii) Mandatory fields are always by Value with the exception of QAPI > arrays, which are handled by Reference (to a block of memory) by > Go. > > iv) All the fields are named with Uppercase due Golang's export > convention. > > v) In order to avoid any kind of issues when encoding or decoding, > to or from JSON, we mark all fields with its @name and, when it is > optional, member, with @omitempty > > Example: > > qapi: > | { 'struct': 'BlockdevCreateOptionsFile', > | 'data': { 'filename': 'str', > | 'size': 'size', > | '*preallocation': 'PreallocMode', > | '*nocow': 'bool', > | '*extent-size-hint': 'size'} } > > go: > | type BlockdevCreateOptionsFile struct { > | Filename string `json:"filename"` > | Size uint64 `json:"size"` > | Preallocation *PreallocMode `json:"preallocation,omitempty"` > | Nocow *bool `json:"nocow,omitempty"` > | ExtentSizeHint *uint64 `json:"extent-size-hint,omitempty"` > | } Note, 'omitempty' shouldn't be used on pointer fields, only scalar fields. The pointer fields are always omitted when nil. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|