unicorn/qemu/qapi/qapi-dealloc-visitor.c
Eric Blake 37ae4dfdfd
qapi: Add parameter to visit_end_*
Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*. The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL. The dealloc visitor is then greatly simplified.

All three visit_end_*() functions intentionally take a void**,
even though the visit_start_*() functions differ between void**,
GenericList**, and GenericAlternate**. This is done for several
reasons: when doing a virtual walk, passing NULL doesn't care
what the type is, but when doing a generated walk, we already
have to cast the caller's specific FOO* to call visit_start,
while using void** lets us use visit_end without a cast. Also,
an upcoming patch will add a clone visitor that wants to use
the same implementation for all three visit_end callbacks,
which is made easier if all three share the same signature.

For visitors with already track per-object state (the QMP visitors
via a stack, and the string visitors which do not allow nesting),
add an assertion that the caller is indeed passing the same
pointer to paired calls.

Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 00:57:54 -05:00

150 lines
3.8 KiB
C

/*
* Dealloc Visitor
*
* 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/error.h"
#include "qapi/dealloc-visitor.h"
#include "qemu/queue.h"
#include "qemu-common.h"
#include "qapi/qmp/types.h"
#include "qapi/visitor-impl.h"
struct QapiDeallocVisitor
{
Visitor visitor;
bool is_list_head;
};
static void qapi_dealloc_start_struct(Visitor *v, const char *name, void **obj,
size_t unused, Error **errp)
{
}
static void qapi_dealloc_end_struct(Visitor *v, void **obj)
{
if (obj) {
g_free(*obj);
}
}
static void qapi_dealloc_start_alternate(Visitor *v, const char *name,
GenericAlternate **obj, size_t size,
bool promote_int, Error **errp)
{
}
static void qapi_dealloc_end_alternate(Visitor *v, void **obj)
{
if (obj) {
g_free(*obj);
}
}
static void qapi_dealloc_start_list(Visitor *v, const char *name,
GenericList **list, size_t size,
Error **errp)
{
}
static GenericList *qapi_dealloc_next_list(Visitor *v, GenericList *tail,
size_t size)
{
GenericList *next = tail->next;
g_free(tail);
return next;
}
static void qapi_dealloc_end_list(Visitor *v, void **obj)
{
}
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_size(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
}
static void qapi_dealloc_type_null(Visitor *v, const char *name, Error **errp)
{
}
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.type = VISITOR_DEALLOC;
v->visitor.start_struct = qapi_dealloc_start_struct;
v->visitor.end_struct = qapi_dealloc_end_struct;
v->visitor.start_alternate = qapi_dealloc_start_alternate;
v->visitor.end_alternate = qapi_dealloc_end_alternate;
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_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.type_null = qapi_dealloc_type_null;
v->visitor.type_size = qapi_dealloc_type_size;
return v;
}