From nobody Sun Oct 26 00:03:05 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 1521639731501960.9376082120499; Wed, 21 Mar 2018 06:42:11 -0700 (PDT) Received: from localhost ([::1]:55188 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eye0G-0000Rk-Tq for importer@patchew.org; Wed, 21 Mar 2018 09:42:08 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50767) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eydyR-0007pz-K2 for qemu-devel@nongnu.org; Wed, 21 Mar 2018 09:40:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eydyQ-0000Jn-Dd for qemu-devel@nongnu.org; Wed, 21 Mar 2018 09:40:15 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:49828 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 1eydyQ-0000JO-8f for qemu-devel@nongnu.org; Wed, 21 Mar 2018 09:40:14 -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 CDFC8A27E3 for ; Wed, 21 Mar 2018 13:40:13 +0000 (UTC) Received: from localhost (ovpn-112-73.ams2.redhat.com [10.36.112.73]) by smtp.corp.redhat.com (Postfix) with ESMTP id 71B63202322F; Wed, 21 Mar 2018 13:40:13 +0000 (UTC) From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: qemu-devel@nongnu.org Date: Wed, 21 Mar 2018 14:40:04 +0100 Message-Id: <20180321134005.8822-3-marcandre.lureau@redhat.com> In-Reply-To: <20180321134005.8822-1-marcandre.lureau@redhat.com> References: <20180321134005.8822-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 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 [10.11.55.2]); Wed, 21 Mar 2018 13:40:13 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 21 Mar 2018 13:40:13 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'marcandre.lureau@redhat.com' RCPT:'' Content-Transfer-Encoding: quoted-printable 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 2/3] qobject: assume base of a qobject is at offset 0 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: armbru@redhat.com, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , pbonzini@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" Simplify casting to QObject by not requiring the definition of the type and assuming base QObject is at offset 0. Add a static check for this. Use the QEMU_GENERIC macro for keeping type safety check and error when given an unknown type. Signed-off-by: Marc-Andr=C3=A9 Lureau --- include/qapi/qmp/qobject.h | 36 ++++++++++++++++++++++++++++++++++-- qobject/qobject.c | 9 +++++++++ 2 files changed, 43 insertions(+), 2 deletions(-) diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h index e022707578..d0aead35ec 100644 --- a/include/qapi/qmp/qobject.h +++ b/include/qapi/qmp/qobject.h @@ -39,8 +39,40 @@ struct QObject { size_t refcnt; }; =20 -/* Get the 'base' part of an object */ -#define QOBJECT(obj) (&(obj)->base) +/* This function gives an error if an invalid pointer type is passed + * to QOBJECT. For optimized builds, we can rely on dead-code + * elimination from the compiler, and give the errors already at link + * time. + */ +#if defined(__OPTIMIZE__) && !defined(__SANITIZE_ADDRESS__) +const void * qobject_unknown_type(const void *); +#else +static inline const void * +qobject_unknown_type(const void *unused) +{ + abort(); + return NULL; +} +#endif + +/* A typecast, checking for the type of arguments */ +/* QObject is at offset 0, for all QObject-derived types */ +#define QOBJECT(x) QEMU_GENERIC(x, \ + (QNull *, (QObject *) x), \ + (const QNull *, (const QObject *) x), \ + (QNum *, (QObject *) x), \ + (const QNum *, (const QObject *) x), \ + (QString *, (QObject *) x), \ + (const QString *, (const QObject *) x), \ + (QDict *, (QObject *) x), \ + (const QDict *, (const QObject *) x), \ + (QList *, (QObject *) x), \ + (const QList *, (const QObject *) x), \ + (QBool *, (QObject *) x), \ + (const QBool *, (const QObject *) x), \ + (QObject *, x), \ + (const QObject *, x), \ + qobject_unknown_type(x)) =20 /* High-level interface for qobject_incref() */ #define QINCREF(obj) \ diff --git a/qobject/qobject.c b/qobject/qobject.c index 23600aa1c1..87649c5be5 100644 --- a/qobject/qobject.c +++ b/qobject/qobject.c @@ -16,6 +16,15 @@ #include "qapi/qmp/qlist.h" #include "qapi/qmp/qstring.h" =20 +QEMU_BUILD_BUG_MSG( + offsetof(QNull, base) !=3D 0 || + offsetof(QNum, base) !=3D 0 || + offsetof(QString, base) !=3D 0 || + offsetof(QDict, base) !=3D 0 || + offsetof(QList, base) !=3D 0 || + offsetof(QBool, base) !=3D 0, + "base qobject must be at offset 0"); + static void (*qdestroy[QTYPE__MAX])(QObject *) =3D { [QTYPE_NONE] =3D NULL, /* No such object exists */ [QTYPE_QNULL] =3D NULL, /* qnull_ is indestructible */ --=20 2.16.2.521.g9aa15f885a