unicorn/qemu/qapi/qmp-output-visitor.c
Eric Blake 3aba81d5aa
qapi: Drop unused error argument for list and implicit struct
No backend was setting an error when ending the visit of a list or
implicit struct, or when moving to the next list node. Make the
callers a bit easier to follow by making this a part of the contract,
and removing the errp argument - callers can then unconditionally end
an object as part of cleanup without having to think about whether a
second error is dominated by a first, because there is no second
error.

A later patch will then tackle the larger task of splitting
visit_end_struct(), which can indeed set an error.

Backports commit 08f9541dec51700abef0c37994213164ca4e4fc9 from qemu
2018-02-19 12:59:54 -05:00

251 lines
6.2 KiB
C

/*
* Core Definitions for QAPI/QMP Command Registry
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.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/qmp-output-visitor.h"
#include "qapi/visitor-impl.h"
#include "qemu/queue.h"
#include "qemu-common.h"
#include "qapi/qmp/types.h"
#include "qapi/qmp/qerror.h"
typedef struct QStackEntry
{
QObject *value;
bool is_list_head;
QTAILQ_ENTRY(QStackEntry) node;
} QStackEntry;
typedef QTAILQ_HEAD(QStack, QStackEntry) QStack;
struct QmpOutputVisitor
{
Visitor visitor;
QStack stack;
};
#define qmp_output_add(qov, name, value) \
qmp_output_add_obj(qov, name, QOBJECT(value))
#define qmp_output_push(qov, value) qmp_output_push_obj(qov, QOBJECT(value))
static QmpOutputVisitor *to_qov(Visitor *v)
{
return container_of(v, QmpOutputVisitor, visitor);
}
static void qmp_output_push_obj(QmpOutputVisitor *qov, QObject *value)
{
QStackEntry *e = g_malloc0(sizeof(*e));
e->value = value;
if (qobject_type(e->value) == QTYPE_QLIST) {
e->is_list_head = true;
}
QTAILQ_INSERT_HEAD(&qov->stack, e, node);
}
static QObject *qmp_output_pop(QmpOutputVisitor *qov)
{
QStackEntry *e = QTAILQ_FIRST(&qov->stack);
QObject *value;
QTAILQ_REMOVE(&qov->stack, e, node);
value = e->value;
g_free(e);
return value;
}
static QObject *qmp_output_first(QmpOutputVisitor *qov)
{
QStackEntry *e = QTAILQ_LAST(&qov->stack, QStack);
/* FIXME - find a better way to deal with NULL values */
if (!e) {
return NULL;
}
return e->value;
}
static QObject *qmp_output_last(QmpOutputVisitor *qov)
{
QStackEntry *e = QTAILQ_FIRST(&qov->stack);
return e->value;
}
static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name,
QObject *value)
{
QObject *cur;
if (QTAILQ_EMPTY(&qov->stack)) {
qmp_output_push_obj(qov, value);
return;
}
cur = qmp_output_last(qov);
switch (qobject_type(cur)) {
case QTYPE_QDICT:
qdict_put_obj(qobject_to_qdict(cur), name, value);
break;
case QTYPE_QLIST:
qlist_append_obj(qobject_to_qlist(cur), value);
break;
default:
qobject_decref(qmp_output_pop(qov));
qmp_output_push_obj(qov, value);
break;
}
}
static void qmp_output_start_struct(Visitor *v, void **obj, const char *kind,
const char *name, size_t unused,
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
QDict *dict = qdict_new();
qmp_output_add(qov, name, dict);
qmp_output_push(qov, dict);
}
static void qmp_output_end_struct(Visitor *v, Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_pop(qov);
}
static void qmp_output_start_list(Visitor *v, const char *name, Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
QList *list = qlist_new();
qmp_output_add(qov, name, list);
qmp_output_push(qov, list);
}
static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp)
{
GenericList *list = *listp;
QmpOutputVisitor *qov = to_qov(v);
QStackEntry *e = QTAILQ_FIRST(&qov->stack);
assert(e);
if (e->is_list_head) {
e->is_list_head = false;
return list;
}
return list ? list->next : NULL;
}
static void qmp_output_end_list(Visitor *v)
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_pop(qov);
}
static void qmp_output_type_int64(Visitor *v, int64_t *obj, const char *name,
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add(qov, name, qint_from_int(*obj));
}
static void qmp_output_type_uint64(Visitor *v, uint64_t *obj, const char *name,
Error **errp)
{
/* FIXME: QMP outputs values larger than INT64_MAX as negative */
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add(qov, name, qint_from_int(*obj));
}
static void qmp_output_type_bool(Visitor *v, bool *obj, const char *name,
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add(qov, name, qbool_from_bool(*obj));
}
static void qmp_output_type_str(Visitor *v, char **obj, const char *name,
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
if (*obj) {
qmp_output_add(qov, name, qstring_from_str(*obj));
} else {
qmp_output_add(qov, name, qstring_from_str(""));
}
}
static void qmp_output_type_number(Visitor *v, double *obj, const char *name,
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add(qov, name, qfloat_from_double(*obj));
}
QObject *qmp_output_get_qobject(QmpOutputVisitor *qov)
{
QObject *obj = qmp_output_first(qov);
if (obj) {
qobject_incref(obj);
}
return obj;
}
Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)
{
return &v->visitor;
}
void qmp_output_visitor_cleanup(QmpOutputVisitor *v)
{
QStackEntry *e, *tmp;
/* The bottom QStackEntry, if any, owns the root QObject. See the
* qmp_output_push_obj() invocations in qmp_output_add_obj(). */
QObject *root = QTAILQ_EMPTY(&v->stack) ? NULL : qmp_output_first(v);
QTAILQ_FOREACH_SAFE(e, &v->stack, node, tmp) {
QTAILQ_REMOVE(&v->stack, e, node);
g_free(e);
}
qobject_decref(root);
g_free(v);
}
QmpOutputVisitor *qmp_output_visitor_new(void)
{
QmpOutputVisitor *v;
v = g_malloc0(sizeof(*v));
v->visitor.start_struct = qmp_output_start_struct;
v->visitor.end_struct = qmp_output_end_struct;
v->visitor.start_list = qmp_output_start_list;
v->visitor.next_list = qmp_output_next_list;
v->visitor.end_list = qmp_output_end_list;
v->visitor.type_enum = output_type_enum;
v->visitor.type_int64 = qmp_output_type_int64;
v->visitor.type_uint64 = qmp_output_type_uint64;
v->visitor.type_bool = qmp_output_type_bool;
v->visitor.type_str = qmp_output_type_str;
v->visitor.type_number = qmp_output_type_number;
QTAILQ_INIT(&v->stack);
return v;
}