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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 E0675C433E0 for ; Tue, 23 Feb 2021 09:08:13 +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 7F38164E21 for ; Tue, 23 Feb 2021 09:08:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F38164E21 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]:53100 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lETfw-000767-Fs for qemu-devel@archiver.kernel.org; Tue, 23 Feb 2021 04:08:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:44424) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lETeW-0006FN-Hw for qemu-devel@nongnu.org; Tue, 23 Feb 2021 04:06:44 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:44036) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lETeR-0000hW-Ip for qemu-devel@nongnu.org; Tue, 23 Feb 2021 04:06:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614071198; 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=TiofZtwhpE3W9O9kmNL48Ob0Lhr/MrTgLe4VNez7Ef8=; b=HG/JiuUwECVfnojtaOv+lVDKx7L7xBOC/S5A2QF3Z57x1sdfO/MGPm3cUaOjMFj2IM/nX8 6w4t053z/GY3gYE5ibzqfdDBWIcOu5QoFzW91rKLYw0X3myf1tOK2/RCUP27xu0QpNUjNI eYQddCxfbxKKN8E5KYjdrmtxRTf87Cw= 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-575-Zu-AqlAuNNmzyO-xxBu1xw-1; Tue, 23 Feb 2021 04:06:36 -0500 X-MC-Unique: Zu-AqlAuNNmzyO-xxBu1xw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E5C5B18B6142; Tue, 23 Feb 2021 09:06:35 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-115-79.ams2.redhat.com [10.36.115.79]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AF3BC1001281; Tue, 23 Feb 2021 09:06:32 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 3A3CA113860F; Tue, 23 Feb 2021 10:06:31 +0100 (CET) From: Markus Armbruster To: Paolo Bonzini Subject: Re: A brief look at deprecating our JSON extensions over RFC 8259 References: <875z2knoa5.fsf@dusky.pond.sub.org> Date: Tue, 23 Feb 2021 10:06:30 +0100 In-Reply-To: (Paolo Bonzini's message of "Mon, 22 Feb 2021 18:47:30 +0100") Message-ID: <87y2fff90p.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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_H3=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: Peter Maydell , "Daniel P. =?utf-8?Q?Berrang=C3=A9?=" , libvir-list@redhat.com, Markus Armbruster , qemu-devel@nongnu.org, John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Paolo Bonzini writes: > On 22/02/21 16:24, Daniel P. Berrang=C3=A9 wrote: >> This problem isn't unique to QEMU. Any app using JSON from the >> shell will have the tedium of quote escaping. JSON is incredibly >> widespread and no other apps felt it neccessary to introduce single >> quoting support, because the benefit doesn't outweigh the interop >> problem it introduces. > > The quotes were introduced for C code (and especially qtest), not for > the shell. We have something like > > response =3D qmp("{ 'execute': 'qom-get', 'arguments': { 'path': %s, = " > "'property': 'temperature' } }", id); > > These are sent to QEMU as double-quoted strings (the single-quoted > JSON is parsed to get interpolation and printed back; commit > 563890c7c7, "libqtest: escape strings in QMP commands, fix leak", > 2014-07-01). However, doing the interpolation requires a parser that > recognizes the single-quoted strings. Doing interpolation requires a parser that recognizes %-sequences. Single quote support isn't *required*, but quite desirable to let us avoid leaning toothpick syndrome (LTS). Example: compare the above to response =3D qmp("{ \"execute\": \"qom-get\", \"arguments\": { \"path= \": %s, " "\"property\": \"temperature\" } }", id); We kept the interpolation extension out of the external interfaces, but not the single quotes. > Markus, did you rebuild the qtests after disabling single-quoted > strings? "make check-qtest-x86_64" would have rebuilt them, but I'm=20 > confused by the results. I ran "make check" and looked at the failures: * check-qjson.c - escaped_string() covers \'. Naturally, this fails. - escaped_string() and utf8_string() try every string twice, first in double quotes, then in single quotes. Naturally, the latter fails. - string_with_quotes() tests unquoted single quote in double-quoted string, and unquoted double quote in single-quoted string. Naturally, the latter fails. - large_dict() and simple_whitespace() use single quotes to avoid LTS. This is the test my "The unit test testing the JSON parser is of course excused" referred to. * test-qobject-input-visitor.c * qtest/qmp-test.c More LTS avoidance. This is "The remaining qtest and the unit test could perhaps be dismissed as atypical use of QEMU from C." * tests/qemu-iotests/ Unlike the tests above, these use *external* interfaces. In shell, we need to use double quotes to get parameter expansion. We then use single quotes to avoid LTS. The Python code has less excuse, I think. Still confused?