unicorn/qemu/qobject/qlist.c
Markus Armbruster d25b8420d0
qlist: Make conversion from QObject * accept null
qobject_to_qlist() crashes on null, which is a trap for the unwary.
Return null instead.

Backports commit 2d6421a90047a83f6722832405fe09571040ea5b from qemu
2018-02-17 15:24:12 -05:00

169 lines
3.2 KiB
C

/*
* QList Module
*
* Copyright (C) 2009 Red Hat Inc.
*
* Authors:
* Luiz Capitulino <lcapitulino@redhat.com>
*
* 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 "qapi/qmp/qlist.h"
#include "qapi/qmp/qobject.h"
#include "qemu/queue.h"
#include "qemu-common.h"
static void qlist_destroy_obj(QObject *obj);
static const QType qlist_type = {
QTYPE_QLIST,
qlist_destroy_obj,
};
/**
* qlist_new(): Create a new QList
*
* Return strong reference.
*/
QList *qlist_new(void)
{
QList *qlist;
qlist = g_malloc(sizeof(*qlist));
QTAILQ_INIT(&qlist->head);
QOBJECT_INIT(qlist, &qlist_type);
return qlist;
}
static void qlist_copy_elem(QObject *obj, void *opaque)
{
QList *dst = opaque;
qobject_incref(obj);
qlist_append_obj(dst, obj);
}
QList *qlist_copy(QList *src)
{
QList *dst = qlist_new();
qlist_iter(src, qlist_copy_elem, dst);
return dst;
}
/**
* qlist_append_obj(): Append an QObject into QList
*
* NOTE: ownership of 'value' is transferred to the QList
*/
void qlist_append_obj(QList *qlist, QObject *value)
{
QListEntry *entry;
entry = g_malloc(sizeof(*entry));
entry->value = value;
QTAILQ_INSERT_TAIL(&qlist->head, entry, next);
}
/**
* qlist_iter(): Iterate over all the list's stored values.
*
* This function allows the user to provide an iterator, which will be
* called for each stored value in the list.
*/
void qlist_iter(const QList *qlist,
void (*iter)(QObject *obj, void *opaque), void *opaque)
{
QListEntry *entry;
QTAILQ_FOREACH(entry, &qlist->head, next)
iter(entry->value, opaque);
}
QObject *qlist_pop(QList *qlist)
{
QListEntry *entry;
QObject *ret;
if (qlist == NULL || QTAILQ_EMPTY(&qlist->head)) {
return NULL;
}
entry = QTAILQ_FIRST(&qlist->head);
QTAILQ_REMOVE(&qlist->head, entry, next);
ret = entry->value;
g_free(entry);
return ret;
}
QObject *qlist_peek(QList *qlist)
{
QListEntry *entry;
QObject *ret;
if (qlist == NULL || QTAILQ_EMPTY(&qlist->head)) {
return NULL;
}
entry = QTAILQ_FIRST(&qlist->head);
ret = entry->value;
return ret;
}
int qlist_empty(const QList *qlist)
{
return QTAILQ_EMPTY(&qlist->head);
}
static void qlist_size_iter(QObject *obj, void *opaque)
{
size_t *count = opaque;
(*count)++;
}
size_t qlist_size(const QList *qlist)
{
size_t count = 0;
qlist_iter(qlist, qlist_size_iter, &count);
return count;
}
/**
* qobject_to_qlist(): Convert a QObject into a QList
*/
QList *qobject_to_qlist(const QObject *obj)
{
if (!obj || qobject_type(obj) != QTYPE_QLIST) {
return NULL;
}
return container_of(obj, QList, base);
}
/**
* qlist_destroy_obj(): Free all the memory allocated by a QList
*/
static void qlist_destroy_obj(QObject *obj)
{
QList *qlist;
QListEntry *entry, *next_entry;
assert(obj != NULL);
qlist = qobject_to_qlist(obj);
QTAILQ_FOREACH_SAFE(entry, &qlist->head, next, next_entry) {
QTAILQ_REMOVE(&qlist->head, entry, next);
qobject_decref(entry->value);
g_free(entry);
}
g_free(qlist);
}