Commit 2c0ef9f4 authored by Eric Blake's avatar Eric Blake Committed by Markus Armbruster

qapi: Add new visit_free() function

Making each visitor provide its own (awkwardly-named) FOO_cleanup()
is unusual, when we can instead have a polymorphic visit_free()
interface.  Over the next few patches, we can use the polymorphic
functions to eliminate the need for a FOO_get_visitor() function
for accessing specific visitor functionality, once everything can
be accessed directly through the Visitor* interfaces.

The dealloc visitor is the first one converted to completely use
the new entry point, since qapi_dealloc_visitor_cleanup() was the
only reason that qapi_dealloc_get_visitor() existed, and only
generated and testsuite code was even using it.  With the new
visit_free() entry point in place, we no longer need to expose
the QapiDeallocVisitor subtype through qapi_dealloc_visitor_new(),
and can get by with less generated code, with diffs that look like:

| void qapi_free_ACPIOSTInfo(ACPIOSTInfo *obj)
| {
|-    QapiDeallocVisitor *qdv;
|     Visitor *v;
|
|     if (!obj) {
|         return;
|     }
|
|-    qdv = qapi_dealloc_visitor_new();
|-    v = qapi_dealloc_get_visitor(qdv);
|+    v = qapi_dealloc_visitor_new();
|     visit_type_ACPIOSTInfo(v, NULL, &obj, NULL);
|-    qapi_dealloc_visitor_cleanup(qdv);
|+    visit_free(v);
|}
Signed-off-by: 's avatarEric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-5-git-send-email-eblake@redhat.com>
Reviewed-by: 's avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: 's avatarMarkus Armbruster <armbru@redhat.com>
parent 1158bb2a
......@@ -802,32 +802,28 @@ Example:
void qapi_free_UserDefOne(UserDefOne *obj)
{
QapiDeallocVisitor *qdv;
Visitor *v;
if (!obj) {
return;
}
qdv = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(qdv);
v = qapi_dealloc_visitor_new();
visit_type_UserDefOne(v, NULL, &obj, NULL);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
}
void qapi_free_UserDefOneList(UserDefOneList *obj)
{
QapiDeallocVisitor *qdv;
Visitor *v;
if (!obj) {
return;
}
qdv = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(qdv);
v = qapi_dealloc_visitor_new();
visit_type_UserDefOneList(v, NULL, &obj, NULL);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
}
=== scripts/qapi-visit.py ===
......@@ -985,7 +981,6 @@ Example:
{
Error *err = NULL;
QmpOutputVisitor *qov = qmp_output_visitor_new();
QapiDeallocVisitor *qdv;
Visitor *v;
v = qmp_output_get_visitor(qov);
......@@ -997,11 +992,10 @@ Example:
out:
error_propagate(errp, err);
qmp_output_visitor_cleanup(qov);
qdv = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(qdv);
visit_free(v);
v = qapi_dealloc_visitor_new();
visit_type_UserDefOne(v, "unused", &ret_in, NULL);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
}
static void qmp_marshal_my_command(QDict *args, QObject **ret, Error **errp)
......@@ -1009,7 +1003,6 @@ Example:
Error *err = NULL;
UserDefOne *retval;
QmpInputVisitor *qiv = qmp_input_visitor_new(QOBJECT(args), true);
QapiDeallocVisitor *qdv;
Visitor *v;
UserDefOneList *arg1 = NULL;
......@@ -1036,13 +1029,12 @@ Example:
out:
error_propagate(errp, err);
qmp_input_visitor_cleanup(qiv);
qdv = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(qdv);
visit_free(v);
v = qapi_dealloc_visitor_new();
visit_start_struct(v, NULL, NULL, 0, NULL);
visit_type_UserDefOneList(v, "arg1", &arg1, NULL);
visit_end_struct(v, NULL);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
}
static void qmp_init_marshal(void)
......
......@@ -23,9 +23,6 @@ typedef struct QapiDeallocVisitor QapiDeallocVisitor;
* qapi_free_FOO() functions, and is the only visitor designed to work
* correctly in the face of a partially-constructed QAPI tree.
*/
QapiDeallocVisitor *qapi_dealloc_visitor_new(void);
void qapi_dealloc_visitor_cleanup(QapiDeallocVisitor *d);
Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v);
Visitor *qapi_dealloc_visitor_new(void);
#endif
......@@ -104,6 +104,9 @@ struct Visitor
/* Must be set */
VisitorType type;
/* Must be set */
void (*free)(Visitor *v);
};
#endif
......@@ -37,6 +37,24 @@
* implemented by each visitor, and docs/qapi-code-gen.txt for more
* about the QAPI code generator.
*
* All of the visitors are created via:
*
* Type *subtype_visitor_new(parameters...);
*
* where Type is either directly 'Visitor *', or is a subtype that can
* be trivially upcast to Visitor * via another function:
*
* Visitor *subtype_get_visitor(SubtypeVisitor *);
*
* A visitor should be used for exactly one top-level visit_type_FOO()
* or virtual walk, then passed to visit_free() to clean up resources.
* It is okay to free the visitor without completing the visit, if
* some other error is detected in the meantime. Output visitors
* provide an additional function, for collecting the final results of
* a successful visit: string_output_get_string() and
* qmp_output_get_qobject(); this collection function should not be
* called if any errors were reported during the visit.
*
* All QAPI types have a corresponding function with a signature
* roughly compatible with this:
*
......@@ -222,6 +240,19 @@ typedef struct GenericAlternate {
char padding[];
} GenericAlternate;
/*** Visitor cleanup ***/
/*
* Free @v and any resources it has tied up.
*
* May be called whether or not the visit has been successfully
* completed, but should not be called until a top-level
* visit_type_FOO() or visit_start_ITEM() has been performed on the
* visitor. Safe if @v is NULL.
*/
void visit_free(Visitor *v);
/*** Visiting structures ***/
/*
......@@ -272,7 +303,7 @@ void visit_check_struct(Visitor *v, Error **errp);
* Must be called after any successful use of visit_start_struct(),
* even if intermediate processing was skipped due to errors, to allow
* the backend to release any resources. Destroying the visitor early
* behaves as if this was implicitly called.
* with visit_free() behaves as if this was implicitly called.
*/
void visit_end_struct(Visitor *v, void **obj);
......@@ -332,7 +363,7 @@ GenericList *visit_next_list(Visitor *v, GenericList *tail, size_t size);
* Must be called after any successful use of visit_start_list(), even
* if intermediate processing was skipped due to errors, to allow the
* backend to release any resources. Destroying the visitor early
* behaves as if this was implicitly called.
* with visit_free() behaves as if this was implicitly called.
*/
void visit_end_list(Visitor *v, void **list);
......@@ -368,7 +399,7 @@ void visit_start_alternate(Visitor *v, const char *name,
* Must be called after any successful use of visit_start_alternate(),
* even if intermediate processing was skipped due to errors, to allow
* the backend to release any resources. Destroying the visitor early
* behaves as if this was implicitly called.
* with visit_free() behaves as if this was implicitly called.
*
*/
void visit_end_alternate(Visitor *v, void **obj);
......
......@@ -513,6 +513,15 @@ opts_optional(Visitor *v, const char *name, bool *present)
}
static void
opts_free(Visitor *v)
{
OptsVisitor *ov = to_ov(v);
opts_visitor_cleanup(ov);
}
OptsVisitor *
opts_visitor_new(const QemuOpts *opts)
{
......@@ -540,6 +549,7 @@ opts_visitor_new(const QemuOpts *opts)
* skip some mandatory methods... */
ov->visitor.optional = &opts_optional;
ov->visitor.free = opts_free;
ov->opts_root = opts;
......
......@@ -107,17 +107,12 @@ static void qapi_dealloc_type_null(Visitor *v, const char *name, Error **errp)
{
}
Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v)
static void qapi_dealloc_free(Visitor *v)
{
return &v->visitor;
g_free(container_of(v, QapiDeallocVisitor, visitor));
}
void qapi_dealloc_visitor_cleanup(QapiDeallocVisitor *v)
{
g_free(v);
}
QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
Visitor *qapi_dealloc_visitor_new(void)
{
QapiDeallocVisitor *v;
......@@ -138,6 +133,7 @@ QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
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.free = qapi_dealloc_free;
return v;
return &v->visitor;
}
......@@ -20,6 +20,13 @@
#include "qapi/visitor.h"
#include "qapi/visitor-impl.h"
void visit_free(Visitor *v)
{
if (v) {
v->free(v);
}
}
void visit_start_struct(Visitor *v, const char *name, void **obj,
size_t size, Error **errp)
{
......
......@@ -378,6 +378,13 @@ Visitor *qmp_input_get_visitor(QmpInputVisitor *v)
return &v->visitor;
}
static void qmp_input_free(Visitor *v)
{
QmpInputVisitor *qiv = to_qiv(v);
qmp_input_visitor_cleanup(qiv);
}
void qmp_input_visitor_cleanup(QmpInputVisitor *v)
{
qobject_decref(v->root);
......@@ -406,6 +413,7 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj, bool strict)
v->visitor.type_any = qmp_input_type_any;
v->visitor.type_null = qmp_input_type_null;
v->visitor.optional = qmp_input_optional;
v->visitor.free = qmp_input_free;
v->strict = strict;
v->root = obj;
......
......@@ -214,6 +214,13 @@ Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)
return &v->visitor;
}
static void qmp_output_free(Visitor *v)
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_visitor_cleanup(qov);
}
void qmp_output_visitor_cleanup(QmpOutputVisitor *v)
{
QStackEntry *e, *tmp;
......@@ -246,6 +253,7 @@ QmpOutputVisitor *qmp_output_visitor_new(void)
v->visitor.type_number = qmp_output_type_number;
v->visitor.type_any = qmp_output_type_any;
v->visitor.type_null = qmp_output_type_null;
v->visitor.free = qmp_output_free;
QTAILQ_INIT(&v->stack);
......
......@@ -331,6 +331,13 @@ Visitor *string_input_get_visitor(StringInputVisitor *v)
return &v->visitor;
}
static void string_input_free(Visitor *v)
{
StringInputVisitor *siv = to_siv(v);
string_input_visitor_cleanup(siv);
}
void string_input_visitor_cleanup(StringInputVisitor *v)
{
g_list_foreach(v->ranges, free_range, NULL);
......@@ -355,6 +362,7 @@ StringInputVisitor *string_input_visitor_new(const char *str)
v->visitor.next_list = next_list;
v->visitor.end_list = end_list;
v->visitor.optional = parse_optional;
v->visitor.free = string_input_free;
v->string = str;
return v;
......
......@@ -322,6 +322,13 @@ static void free_range(void *range, void *dummy)
g_free(range);
}
static void string_output_free(Visitor *v)
{
StringOutputVisitor *sov = to_sov(v);
string_output_visitor_cleanup(sov);
}
void string_output_visitor_cleanup(StringOutputVisitor *sov)
{
if (sov->string) {
......@@ -351,6 +358,7 @@ StringOutputVisitor *string_output_visitor_new(bool human)
v->visitor.start_list = start_list;
v->visitor.next_list = next_list;
v->visitor.end_list = end_list;
v->visitor.free = string_output_free;
return v;
}
......@@ -62,7 +62,6 @@ static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out,
{
Error *err = NULL;
QmpOutputVisitor *qov = qmp_output_visitor_new();
QapiDeallocVisitor *qdv;
Visitor *v;
v = qmp_output_get_visitor(qov);
......@@ -74,11 +73,10 @@ static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out,
out:
error_propagate(errp, err);
qmp_output_visitor_cleanup(qov);
qdv = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(qdv);
visit_free(v);
v = qapi_dealloc_visitor_new();
visit_type_%(c_name)s(v, "unused", &ret_in, NULL);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
}
''',
c_type=ret_type.c_type(), c_name=ret_type.c_name())
......@@ -116,7 +114,6 @@ def gen_marshal(name, arg_type, ret_type):
if arg_type and arg_type.members:
ret += mcgen('''
QmpInputVisitor *qiv = qmp_input_visitor_new(QOBJECT(args), true);
QapiDeallocVisitor *qdv;
Visitor *v;
%(c_name)s arg = {0};
......@@ -155,13 +152,12 @@ out:
''')
if arg_type and arg_type.members:
ret += mcgen('''
qmp_input_visitor_cleanup(qiv);
qdv = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(qdv);
visit_free(v);
v = qapi_dealloc_visitor_new();
visit_start_struct(v, NULL, NULL, 0, NULL);
visit_type_%(c_name)s_members(v, &arg, NULL);
visit_end_struct(v, NULL);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
''',
c_name=arg_type.c_name())
......
......@@ -119,7 +119,7 @@ def gen_event_send(name, arg_type):
if arg_type and arg_type.members:
ret += mcgen('''
out:
qmp_output_visitor_cleanup(qov);
visit_free(v);
''')
ret += mcgen('''
error_propagate(errp, err);
......
......@@ -150,17 +150,15 @@ def gen_type_cleanup(name):
void qapi_free_%(c_name)s(%(c_name)s *obj)
{
QapiDeallocVisitor *qdv;
Visitor *v;
if (!obj) {
return;
}
qdv = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(qdv);
v = qapi_dealloc_visitor_new();
visit_type_%(c_name)s(v, NULL, &obj, NULL);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
}
''',
c_name=c_name(name))
......
......@@ -89,11 +89,11 @@ typedef void (*VisitorFunc)(Visitor *v, void **native, Error **errp);
static void dealloc_helper(void *native_in, VisitorFunc visit, Error **errp)
{
QapiDeallocVisitor *qdv = qapi_dealloc_visitor_new();
Visitor *v = qapi_dealloc_visitor_new();
visit(qapi_dealloc_get_visitor(qdv), &native_in, errp);
visit(v, &native_in, errp);
qapi_dealloc_visitor_cleanup(qdv);
visit_free(v);
}
static void visit_primitive_type(Visitor *v, void **native, Error **errp)
......
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