qemu/qapi/qobject-output-visitor.c
Markus Armbruster 57df0dff1a qapi: Extend -compat to set policy for unstable interfaces
New option parameters unstable-input and unstable-output set policy
for unstable interfaces just like deprecated-input and
deprecated-output set policy for deprecated interfaces (see commit
6dd75472d5 "qemu-options: New -compat to set policy for deprecated
interfaces").  This is intended for testing users of the management
interfaces.  It is experimental.

For now, this covers only syntactic aspects of QMP, i.e. stuff tagged
with feature 'unstable'.  We may want to extend it to cover semantic
aspects, or the command line.

Note that there is no good way for management application to detect
presence of these new option parameters: they are not visible output
of query-qmp-schema or query-command-line-options.  Tolerable, because
it's meant for testing.  If running with -compat fails, skip the test.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Message-Id: <20211028102520.747396-10-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Doc comments fixed up]
2021-10-29 21:28:01 +02:00

281 lines
8.3 KiB
C

/*
* Core Definitions for QAPI/QMP Command Registry
*
* Copyright (C) 2012-2016 Red Hat, Inc.
* 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/compat-policy.h"
#include "qapi/qobject-output-visitor.h"
#include "qapi/visitor-impl.h"
#include "qemu/queue.h"
#include "qapi/qmp/qbool.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qlist.h"
#include "qapi/qmp/qnull.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qstring.h"
typedef struct QStackEntry {
QObject *value;
void *qapi; /* sanity check that caller uses same pointer */
QSLIST_ENTRY(QStackEntry) node;
} QStackEntry;
struct QObjectOutputVisitor {
Visitor visitor;
QSLIST_HEAD(, QStackEntry) stack; /* Stack of unfinished containers */
QObject *root; /* Root of the output visit */
QObject **result; /* User's storage location for result */
};
#define qobject_output_add(qov, name, value) \
qobject_output_add_obj(qov, name, QOBJECT(value))
#define qobject_output_push(qov, value, qapi) \
qobject_output_push_obj(qov, QOBJECT(value), qapi)
static QObjectOutputVisitor *to_qov(Visitor *v)
{
return container_of(v, QObjectOutputVisitor, visitor);
}
/* Push @value onto the stack of current QObjects being built */
static void qobject_output_push_obj(QObjectOutputVisitor *qov, QObject *value,
void *qapi)
{
QStackEntry *e = g_malloc0(sizeof(*e));
assert(qov->root);
assert(value);
e->value = value;
e->qapi = qapi;
QSLIST_INSERT_HEAD(&qov->stack, e, node);
}
/* Pop a value off the stack of QObjects being built, and return it. */
static QObject *qobject_output_pop(QObjectOutputVisitor *qov, void *qapi)
{
QStackEntry *e = QSLIST_FIRST(&qov->stack);
QObject *value;
assert(e);
assert(e->qapi == qapi);
QSLIST_REMOVE_HEAD(&qov->stack, node);
value = e->value;
assert(value);
g_free(e);
return value;
}
/* Add @value to the current QObject being built.
* If the stack is visiting a dictionary or list, @value is now owned
* by that container. Otherwise, @value is now the root. */
static void qobject_output_add_obj(QObjectOutputVisitor *qov, const char *name,
QObject *value)
{
QStackEntry *e = QSLIST_FIRST(&qov->stack);
QObject *cur = e ? e->value : NULL;
if (!cur) {
/* Don't allow reuse of visitor on more than one root */
assert(!qov->root);
qov->root = value;
} else {
switch (qobject_type(cur)) {
case QTYPE_QDICT:
assert(name);
qdict_put_obj(qobject_to(QDict, cur), name, value);
break;
case QTYPE_QLIST:
assert(!name);
qlist_append_obj(qobject_to(QList, cur), value);
break;
default:
g_assert_not_reached();
}
}
}
static bool qobject_output_start_struct(Visitor *v, const char *name,
void **obj, size_t unused, Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
QDict *dict = qdict_new();
qobject_output_add(qov, name, dict);
qobject_output_push(qov, dict, obj);
return true;
}
static void qobject_output_end_struct(Visitor *v, void **obj)
{
QObjectOutputVisitor *qov = to_qov(v);
QObject *value = qobject_output_pop(qov, obj);
assert(qobject_type(value) == QTYPE_QDICT);
}
static bool qobject_output_start_list(Visitor *v, const char *name,
GenericList **listp, size_t size,
Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
QList *list = qlist_new();
qobject_output_add(qov, name, list);
qobject_output_push(qov, list, listp);
return true;
}
static GenericList *qobject_output_next_list(Visitor *v, GenericList *tail,
size_t size)
{
return tail->next;
}
static void qobject_output_end_list(Visitor *v, void **obj)
{
QObjectOutputVisitor *qov = to_qov(v);
QObject *value = qobject_output_pop(qov, obj);
assert(qobject_type(value) == QTYPE_QLIST);
}
static bool qobject_output_type_int64(Visitor *v, const char *name,
int64_t *obj, Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
qobject_output_add(qov, name, qnum_from_int(*obj));
return true;
}
static bool qobject_output_type_uint64(Visitor *v, const char *name,
uint64_t *obj, Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
qobject_output_add(qov, name, qnum_from_uint(*obj));
return true;
}
static bool qobject_output_type_bool(Visitor *v, const char *name, bool *obj,
Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
qobject_output_add(qov, name, qbool_from_bool(*obj));
return true;
}
static bool qobject_output_type_str(Visitor *v, const char *name, char **obj,
Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
if (*obj) {
qobject_output_add(qov, name, qstring_from_str(*obj));
} else {
qobject_output_add(qov, name, qstring_from_str(""));
}
return true;
}
static bool qobject_output_type_number(Visitor *v, const char *name,
double *obj, Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
qobject_output_add(qov, name, qnum_from_double(*obj));
return true;
}
static bool qobject_output_type_any(Visitor *v, const char *name,
QObject **obj, Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
qobject_output_add_obj(qov, name, qobject_ref(*obj));
return true;
}
static bool qobject_output_type_null(Visitor *v, const char *name,
QNull **obj, Error **errp)
{
QObjectOutputVisitor *qov = to_qov(v);
qobject_output_add(qov, name, qnull());
return true;
}
static bool qobject_output_policy_skip(Visitor *v, const char *name,
unsigned special_features)
{
CompatPolicy *pol = &v->compat_policy;
return ((special_features & 1u << QAPI_DEPRECATED)
&& pol->deprecated_output == COMPAT_POLICY_OUTPUT_HIDE)
|| ((special_features & 1u << QAPI_UNSTABLE)
&& pol->unstable_output == COMPAT_POLICY_OUTPUT_HIDE);
}
/* Finish building, and return the root object.
* The root object is never null. The caller becomes the object's
* owner, and should use qobject_unref() when done with it. */
static void qobject_output_complete(Visitor *v, void *opaque)
{
QObjectOutputVisitor *qov = to_qov(v);
/* A visit must have occurred, with each start paired with end. */
assert(qov->root && QSLIST_EMPTY(&qov->stack));
assert(opaque == qov->result);
*qov->result = qobject_ref(qov->root);
qov->result = NULL;
}
static void qobject_output_free(Visitor *v)
{
QObjectOutputVisitor *qov = to_qov(v);
QStackEntry *e;
while (!QSLIST_EMPTY(&qov->stack)) {
e = QSLIST_FIRST(&qov->stack);
QSLIST_REMOVE_HEAD(&qov->stack, node);
g_free(e);
}
qobject_unref(qov->root);
g_free(qov);
}
Visitor *qobject_output_visitor_new(QObject **result)
{
QObjectOutputVisitor *v;
v = g_malloc0(sizeof(*v));
v->visitor.type = VISITOR_OUTPUT;
v->visitor.start_struct = qobject_output_start_struct;
v->visitor.end_struct = qobject_output_end_struct;
v->visitor.start_list = qobject_output_start_list;
v->visitor.next_list = qobject_output_next_list;
v->visitor.end_list = qobject_output_end_list;
v->visitor.type_int64 = qobject_output_type_int64;
v->visitor.type_uint64 = qobject_output_type_uint64;
v->visitor.type_bool = qobject_output_type_bool;
v->visitor.type_str = qobject_output_type_str;
v->visitor.type_number = qobject_output_type_number;
v->visitor.type_any = qobject_output_type_any;
v->visitor.type_null = qobject_output_type_null;
v->visitor.policy_skip = qobject_output_policy_skip;
v->visitor.complete = qobject_output_complete;
v->visitor.free = qobject_output_free;
*result = NULL;
v->result = result;
return &v->visitor;
}