From nobody Wed Nov 5 10:44:11 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1533730498444495.9461518805283; Wed, 8 Aug 2018 05:14:58 -0700 (PDT) Received: from localhost ([::1]:43212 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fnNMf-0007o2-6Q for importer@patchew.org; Wed, 08 Aug 2018 08:14:57 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52453) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fnNBn-0006ga-4n for qemu-devel@nongnu.org; Wed, 08 Aug 2018 08:03:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fnNBj-0008TZ-A3 for qemu-devel@nongnu.org; Wed, 08 Aug 2018 08:03:43 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:51068 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fnNBj-0008Rk-28 for qemu-devel@nongnu.org; Wed, 08 Aug 2018 08:03:39 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7CB004023461; Wed, 8 Aug 2018 12:03:38 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-117-62.ams2.redhat.com [10.36.117.62]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5331320180F5; Wed, 8 Aug 2018 12:03:38 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 6A23A11386C1; Wed, 8 Aug 2018 14:03:34 +0200 (CEST) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Wed, 8 Aug 2018 14:03:00 +0200 Message-Id: <20180808120334.10970-23-armbru@redhat.com> In-Reply-To: <20180808120334.10970-1-armbru@redhat.com> References: <20180808120334.10970-1-armbru@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 08 Aug 2018 12:03:38 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 08 Aug 2018 12:03:38 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'armbru@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH 22/56] json: Report first rather than last parse error X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: marcandre.lureau@redhat.com, mdroth@linux.vnet.ibm.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Quiz time! When a parser reports multiple errors, but the user gets to see just one, which one is (on average) the least useful one? Yes, you're right, it's the last one! You're clearly familiar with compilers. Which one does QEMU report? Right again, the last one! You're clearly familiar with QEMU. Reproducer: feeding {"abc\xC2ijk": 1}\n to QMP produces {"error": {"class": "GenericError", "desc": "JSON parse error, key is n= ot a string in object"}} Report the first error instead. The reproducer now produces {"error": {"class": "GenericError", "desc": "JSON parse error, invalid = UTF-8 sequence in string"}} Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake --- qobject/json-parser.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/qobject/json-parser.c b/qobject/json-parser.c index 6b60b07e09..b3a95be3c8 100644 --- a/qobject/json-parser.c +++ b/qobject/json-parser.c @@ -54,13 +54,13 @@ static void GCC_FMT_ATTR(3, 4) parse_error(JSONParserCo= ntext *ctxt, { va_list ap; char message[1024]; + + if (ctxt->err) { + return; + } va_start(ap, msg); vsnprintf(message, sizeof(message), msg, ap); va_end(ap); - if (ctxt->err) { - error_free(ctxt->err); - ctxt->err =3D NULL; - } error_setg(&ctxt->err, "JSON parse error, %s", message); } =20 --=20 2.17.1