3d3eacaecc
By moving the base fields to a QObjectBase_, QObject can be a type which also has a 'base' field. This allows writing a generic QOBJECT() macro that will work with any QObject type, including QObject itself. The container_of() macro ensures that the object to cast has a QObjectBase_ base field, giving some type safety guarantees. QObject must have no members but QObjectBase_ base, or else QOBJECT() breaks. QObjectBase_ is not a typedef and uses a trailing underscore to make it obvious it is not for normal use and to avoid potential abuse. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180419150145.24795-3-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/*
|
|
* QObject
|
|
*
|
|
* Copyright (C) 2015 Red Hat, Inc.
|
|
*
|
|
* This work is licensed under the terms of the GNU LGPL, version 2.1
|
|
* or later. See the COPYING.LIB file in the top-level directory.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "qemu-common.h"
|
|
#include "qapi/qmp/qbool.h"
|
|
#include "qapi/qmp/qnull.h"
|
|
#include "qapi/qmp/qnum.h"
|
|
#include "qapi/qmp/qdict.h"
|
|
#include "qapi/qmp/qlist.h"
|
|
#include "qapi/qmp/qstring.h"
|
|
|
|
QEMU_BUILD_BUG_MSG(
|
|
offsetof(QNull, base) != 0 ||
|
|
offsetof(QNum, base) != 0 ||
|
|
offsetof(QString, base) != 0 ||
|
|
offsetof(QDict, base) != 0 ||
|
|
offsetof(QList, base) != 0 ||
|
|
offsetof(QBool, base) != 0,
|
|
"base qobject must be at offset 0");
|
|
|
|
static void (*qdestroy[QTYPE__MAX])(QObject *) = {
|
|
[QTYPE_NONE] = NULL, /* No such object exists */
|
|
[QTYPE_QNULL] = NULL, /* qnull_ is indestructible */
|
|
[QTYPE_QNUM] = qnum_destroy_obj,
|
|
[QTYPE_QSTRING] = qstring_destroy_obj,
|
|
[QTYPE_QDICT] = qdict_destroy_obj,
|
|
[QTYPE_QLIST] = qlist_destroy_obj,
|
|
[QTYPE_QBOOL] = qbool_destroy_obj,
|
|
};
|
|
|
|
void qobject_destroy(QObject *obj)
|
|
{
|
|
assert(!obj->base.refcnt);
|
|
assert(QTYPE_QNULL < obj->base.type && obj->base.type < QTYPE__MAX);
|
|
qdestroy[obj->base.type](obj);
|
|
}
|
|
|
|
|
|
static bool (*qis_equal[QTYPE__MAX])(const QObject *, const QObject *) = {
|
|
[QTYPE_NONE] = NULL, /* No such object exists */
|
|
[QTYPE_QNULL] = qnull_is_equal,
|
|
[QTYPE_QNUM] = qnum_is_equal,
|
|
[QTYPE_QSTRING] = qstring_is_equal,
|
|
[QTYPE_QDICT] = qdict_is_equal,
|
|
[QTYPE_QLIST] = qlist_is_equal,
|
|
[QTYPE_QBOOL] = qbool_is_equal,
|
|
};
|
|
|
|
bool qobject_is_equal(const QObject *x, const QObject *y)
|
|
{
|
|
/* We cannot test x == y because an object does not need to be
|
|
* equal to itself (e.g. NaN floats are not). */
|
|
|
|
if (!x && !y) {
|
|
return true;
|
|
}
|
|
|
|
if (!x || !y || x->base.type != y->base.type) {
|
|
return false;
|
|
}
|
|
|
|
assert(QTYPE_NONE < x->base.type && x->base.type < QTYPE__MAX);
|
|
|
|
return qis_equal[x->base.type](x, y);
|
|
}
|