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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 8BF42C4363A for ; Tue, 20 Oct 2020 18:27:46 +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 D90A82085B for ; Tue, 20 Oct 2020 18:27:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="g/t8cUa3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D90A82085B 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]:40736 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kUwMK-0007cb-S1 for qemu-devel@archiver.kernel.org; Tue, 20 Oct 2020 14:27:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51396) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kUwLC-0006RF-FY for qemu-devel@nongnu.org; Tue, 20 Oct 2020 14:26:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33897) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kUwL9-00082i-SH for qemu-devel@nongnu.org; Tue, 20 Oct 2020 14:26:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603218389; 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=LF73k65ov8x4+X5zOZr74OODwusf/PEsFSrUJbZcy+I=; b=g/t8cUa3sjB/1MmwPjMJYeie/tA6Os7z9S4baz+ACN52xIFUEVL1eKNa9y30IIbAowATIp x6XcrNCagzbgeaXSAhsoUr21hBmsBc8Jcv5iynH44DWAA1H0OQtJ0lL8KByJcMmU8BhUa6 JmOO5A58lD0CRX4dYl5Uv+nygPaMOi8= 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-557-ECmK8S0xNNuF9_bspyQ4aA-1; Tue, 20 Oct 2020 14:26:24 -0400 X-MC-Unique: ECmK8S0xNNuF9_bspyQ4aA-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 860CE805723; Tue, 20 Oct 2020 18:26:23 +0000 (UTC) Received: from [10.3.113.90] (ovpn-113-90.phx2.redhat.com [10.3.113.90]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CCEE460C0F; Tue, 20 Oct 2020 18:26:19 +0000 (UTC) Subject: Re: [PATCH v4 4/7] nbd: Update qapi to support exporting multiple bitmaps To: Markus Armbruster References: <20201009215533.1194742-1-eblake@redhat.com> <20201009215533.1194742-5-eblake@redhat.com> <6ee3ac4f-65c3-fdfd-9adb-9bea5f5739e3@virtuozzo.com> <56b413b5-2213-1b4e-5cac-865d8f0e0689@redhat.com> <87lfg1gu06.fsf@dusky.pond.sub.org> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <4d7d4c9b-3b32-0c13-9ec1-b326e49ca7ae@redhat.com> Date: Tue, 20 Oct 2020 13:26:19 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <87lfg1gu06.fsf@dusky.pond.sub.org> 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=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/20 01:16:16 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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, Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org, rjones@redhat.com, stefanha@redhat.com, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 10/20/20 3:51 AM, Markus Armbruster wrote: >> #define QAPI_LIST_ADD(list, element) do { \ >> typeof(list) _tmp = g_new(typeof(*(list)), 1); \ >> _tmp->value = (element); \ >> _tmp->next = (list); \ >> (list) = _tmp; \ >> } while (0) >> >> >> Markus, thoughts on if we should publish this macro, > > If it's widely useful. > > "git-grep -- '->value ='" matches ~200 times. A patch converting these > to the macro where possible would make a strong case for having the > macro. > >> and if so, which >> header would be best? > > The macro is generic: @list's type may be any of the struct TYPEList we > generate for the QAPI type ['TYPE']. > > We don't want to generate this macro next to each of these struct > definitions. A non-generic macro would go there, but let's not generate > almost a hundred non-generic macros where a single generic one can do > the job. Agreed. > > The closest we have to a common base is GenericList. It's in in > visitor.h because it's only used by visitors so far. Adding the macro > next it is not so smart, because we don't want non-visitor code to > include visitor.h just for this macro. Also agreed. > > Perhaps the macro should go into qapi/util.h, and perhaps GenericList > and GenericAlternate should move there, too. GenericList is easy, but GenericAlternate is harder: it would introduce a cyclic declaration dependency (generated qapi-builtin-types.h includes qapi/util.h for the definition of QEnumLookup, but qapi/util.h declaring GenericAlternate would depend on including qapi-builtin-types.h for the definition of QType). -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org