qemu-e2k/qapi/qapi-dealloc-visitor.c

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/*
* Dealloc Visitor
*
* Copyright (C) 2012-2016 Red Hat, Inc.
* Copyright IBM, Corp. 2011
*
* Authors:
* Michael Roth <mdroth@linux.vnet.ibm.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 "qemu/osdep.h"
#include "qapi/dealloc-visitor.h"
#include "qemu/queue.h"
#include "qemu-common.h"
#include "qapi/qmp/types.h"
#include "qapi/visitor-impl.h"
typedef struct StackEntry
{
void *value;
bool is_list_head;
QTAILQ_ENTRY(StackEntry) node;
} StackEntry;
struct QapiDeallocVisitor
{
Visitor visitor;
QTAILQ_HEAD(, StackEntry) stack;
};
static QapiDeallocVisitor *to_qov(Visitor *v)
{
return container_of(v, QapiDeallocVisitor, visitor);
}
static void qapi_dealloc_push(QapiDeallocVisitor *qov, void *value)
{
StackEntry *e = g_malloc0(sizeof(*e));
e->value = value;
/* see if we're just pushing a list head tracker */
if (value == NULL) {
e->is_list_head = true;
}
QTAILQ_INSERT_HEAD(&qov->stack, e, node);
}
static void *qapi_dealloc_pop(QapiDeallocVisitor *qov)
{
StackEntry *e = QTAILQ_FIRST(&qov->stack);
QObject *value;
QTAILQ_REMOVE(&qov->stack, e, node);
value = e->value;
g_free(e);
return value;
}
static void qapi_dealloc_start_struct(Visitor *v, const char *name, void **obj,
size_t unused, Error **errp)
{
QapiDeallocVisitor *qov = to_qov(v);
qapi_dealloc_push(qov, obj);
}
static void qapi_dealloc_end_struct(Visitor *v, Error **errp)
{
QapiDeallocVisitor *qov = to_qov(v);
void **obj = qapi_dealloc_pop(qov);
if (obj) {
g_free(*obj);
}
}
static void qapi_dealloc_start_implicit_struct(Visitor *v,
void **obj,
size_t size,
Error **errp)
{
QapiDeallocVisitor *qov = to_qov(v);
qapi_dealloc_push(qov, obj);
}
static void qapi_dealloc_end_implicit_struct(Visitor *v)
{
QapiDeallocVisitor *qov = to_qov(v);
void **obj = qapi_dealloc_pop(qov);
if (obj) {
g_free(*obj);
}
}
static void qapi_dealloc_start_list(Visitor *v, const char *name, Error **errp)
{
QapiDeallocVisitor *qov = to_qov(v);
qapi_dealloc_push(qov, NULL);
}
static GenericList *qapi_dealloc_next_list(Visitor *v, GenericList **listp)
{
GenericList *list = *listp;
QapiDeallocVisitor *qov = to_qov(v);
StackEntry *e = QTAILQ_FIRST(&qov->stack);
if (e && e->is_list_head) {
e->is_list_head = false;
return list;
}
if (list) {
list = list->next;
g_free(*listp);
return list;
}
return NULL;
}
static void qapi_dealloc_end_list(Visitor *v)
{
QapiDeallocVisitor *qov = to_qov(v);
void *obj = qapi_dealloc_pop(qov);
assert(obj == NULL); /* should've been list head tracker with no payload */
}
static void qapi_dealloc_type_str(Visitor *v, const char *name, char **obj,
Error **errp)
{
if (obj) {
g_free(*obj);
}
}
static void qapi_dealloc_type_int64(Visitor *v, const char *name, int64_t *obj,
Error **errp)
{
}
static void qapi_dealloc_type_uint64(Visitor *v, const char *name,
uint64_t *obj, Error **errp)
{
}
static void qapi_dealloc_type_bool(Visitor *v, const char *name, bool *obj,
Error **errp)
{
}
static void qapi_dealloc_type_number(Visitor *v, const char *name, double *obj,
Error **errp)
{
}
static void qapi_dealloc_type_anything(Visitor *v, const char *name,
QObject **obj, Error **errp)
{
if (obj) {
qobject_decref(*obj);
}
}
static void qapi_dealloc_type_enum(Visitor *v, const char *name, int *obj,
const char * const strings[], Error **errp)
{
}
/* If there's no data present, the dealloc visitor has nothing to free.
* Thus, indicate to visitor code that the subsequent union fields can
* be skipped. This is not an error condition, since the cleanup of the
* rest of an object can continue unhindered, so leave errp unset in
* these cases.
*
* NOTE: In cases where we're attempting to deallocate an object that
* may have missing fields, the field indicating the union type may
* be missing. In such a case, it's possible we don't have enough
* information to differentiate data_present == false from a case where
* data *is* present but happens to be a scalar with a value of 0.
* This is okay, since in the case of the dealloc visitor there's no
* work that needs to done in either situation.
*
* The current inability in QAPI code to more thoroughly verify a union
* type in such cases will likely need to be addressed if we wish to
* implement this interface for other types of visitors in the future,
* however.
*/
static bool qapi_dealloc_start_union(Visitor *v, bool data_present,
Error **errp)
{
return data_present;
}
Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v)
{
return &v->visitor;
}
void qapi_dealloc_visitor_cleanup(QapiDeallocVisitor *v)
{
g_free(v);
}
QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
{
QapiDeallocVisitor *v;
v = g_malloc0(sizeof(*v));
v->visitor.start_struct = qapi_dealloc_start_struct;
v->visitor.end_struct = qapi_dealloc_end_struct;
v->visitor.start_implicit_struct = qapi_dealloc_start_implicit_struct;
v->visitor.end_implicit_struct = qapi_dealloc_end_implicit_struct;
v->visitor.start_list = qapi_dealloc_start_list;
v->visitor.next_list = qapi_dealloc_next_list;
v->visitor.end_list = qapi_dealloc_end_list;
v->visitor.type_enum = qapi_dealloc_type_enum;
v->visitor.type_int64 = qapi_dealloc_type_int64;
v->visitor.type_uint64 = qapi_dealloc_type_uint64;
v->visitor.type_bool = qapi_dealloc_type_bool;
v->visitor.type_str = qapi_dealloc_type_str;
v->visitor.type_number = qapi_dealloc_type_number;
v->visitor.type_any = qapi_dealloc_type_anything;
v->visitor.start_union = qapi_dealloc_start_union;
QTAILQ_INIT(&v->stack);
return v;
}