@@ -338,6 +338,17 @@ static void qmp_input_type_any(Visitor *v, const char *name, QObject **obj,
*obj = qobj;
}
+static void qmp_input_type_null(Visitor *v, const char *name, Error **errp)
+{
+ QmpInputVisitor *qiv = to_qiv(v);
+ QObject *qobj = qmp_input_get_object(qiv, name, true);
+
+ if (qobject_type(qobj) != QTYPE_QNULL) {
+ error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+ "null");
+ }
+}
+
static void qmp_input_optional(Visitor *v, const char *name, bool *present)
{
QmpInputVisitor *qiv = to_qiv(v);
@@ -381,6 +392,7 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj)
v->visitor.type_str = qmp_input_type_str;
v->visitor.type_number = qmp_input_type_number;
v->visitor.type_any = qmp_input_type_any;
+ v->visitor.type_null = qmp_input_type_null;
v->visitor.optional = qmp_input_optional;
qmp_input_push(v, obj, NULL, NULL);
@@ -196,6 +196,12 @@ static void qmp_output_type_any(Visitor *v, const char *name, QObject **obj,
qmp_output_add_obj(qov, name, *obj);
}
+static void qmp_output_type_null(Visitor *v, const char *name, Error **errp)
+{
+ QmpOutputVisitor *qov = to_qov(v);
+ qmp_output_add_obj(qov, name, qnull());
+}
+
/* Finish building, and return the root object. Will not be NULL. */
QObject *qmp_output_get_qobject(QmpOutputVisitor *qov)
{
@@ -246,6 +252,7 @@ QmpOutputVisitor *qmp_output_visitor_new(void)
v->visitor.type_str = qmp_output_type_str;
v->visitor.type_number = qmp_output_type_number;
v->visitor.type_any = qmp_output_type_any;
+ v->visitor.type_null = qmp_output_type_null;
QTAILQ_INIT(&v->stack);
@@ -11,6 +11,7 @@
#include "qapi/qmp/qobject.h"
#include "qemu-common.h"
+#include "qapi/qmp-input-visitor.h"
#include "qapi/qmp-output-visitor.h"
/*
@@ -37,15 +38,22 @@ static void qnull_visit_test(void)
{
QObject *obj;
QmpOutputVisitor *qov;
+ QmpInputVisitor *qiv;
g_assert(qnull_.refcnt == 1);
+ obj = qnull();
+ qiv = qmp_input_visitor_new(obj);
+ qobject_decref(obj);
+ visit_type_null(qmp_input_get_visitor(qiv), NULL, &error_abort);
+
qov = qmp_output_visitor_new();
- /* FIXME: Empty visits are ugly, we should have a visit_type_null(). */
+ visit_type_null(qmp_output_get_visitor(qov), NULL, &error_abort);
obj = qmp_output_get_qobject(qov);
g_assert(obj == &qnull_);
qobject_decref(obj);
qmp_output_visitor_cleanup(qov);
+ qmp_input_visitor_cleanup(qiv);
g_assert(qnull_.refcnt == 1);
}
@@ -278,6 +278,20 @@ static void test_visitor_in_any(TestInputVisitorData *data,
qobject_decref(res);
}
+static void test_visitor_in_null(TestInputVisitorData *data,
+ const void *unused)
+{
+ Visitor *v;
+
+ v = visitor_input_test_init(data, "null");
+ visit_type_null(v, NULL, &error_abort);
+
+ v = visitor_input_test_init(data, "{ 'a': null }");
+ visit_start_struct(v, NULL, NULL, 0, &error_abort);
+ visit_type_null(v, "a", &error_abort);
+ visit_end_struct(v, &error_abort);
+}
+
static void test_visitor_in_union_flat(TestInputVisitorData *data,
const void *unused)
{
@@ -828,6 +842,8 @@ int main(int argc, char **argv)
&in_visitor_data, test_visitor_in_list);
input_visitor_test_add("/visitor/input/any",
&in_visitor_data, test_visitor_in_any);
+ input_visitor_test_add("/visitor/input/null",
+ &in_visitor_data, test_visitor_in_null);
input_visitor_test_add("/visitor/input/union-flat",
&in_visitor_data, test_visitor_in_union_flat);
input_visitor_test_add("/visitor/input/alternate",
@@ -476,11 +476,12 @@ static void test_visitor_out_alternate(TestOutputVisitorData *data,
qobject_decref(arg);
}
-static void test_visitor_out_empty(TestOutputVisitorData *data,
- const void *unused)
+static void test_visitor_out_null(TestOutputVisitorData *data,
+ const void *unused)
{
QObject *arg;
+ visit_type_null(data->ov, NULL, &error_abort);
arg = qmp_output_get_qobject(data->qov);
g_assert(qobject_type(arg) == QTYPE_QNULL);
qobject_decref(arg);
@@ -836,8 +837,8 @@ int main(int argc, char **argv)
&out_visitor_data, test_visitor_out_union_flat);
output_visitor_test_add("/visitor/output/alternate",
&out_visitor_data, test_visitor_out_alternate);
- output_visitor_test_add("/visitor/output/empty",
- &out_visitor_data, test_visitor_out_empty);
+ output_visitor_test_add("/visitor/output/null",
+ &out_visitor_data, test_visitor_out_null);
output_visitor_test_add("/visitor/output/native_list/int",
&out_visitor_data,
test_visitor_out_native_list_int);
Implement the new type_null() callback for the qmp input and output visitors. While we don't yet have a use for this in QAPI input (the generator will need some tweaks first), one usage is already envisioned: when changing blockdev parameters, it would be nice to have a difference between leaving a tuning parameter unchanged (omit that parameter from the struct) and to explicitly reset the parameter to its default without having to know what the default value is (specify the parameter with an explicit null value, which will require us to allow a QAPI alternate that chooses between the normal value and an explicit null). Meanwhile, the output visitor could already output explicit null via type_any, but this gives us finer control. At any rate, it's easy to test that we can round-trip an explicit null through manual use of visit_type_null(). Repurpose the test_visitor_out_empty test, particularly since a future patch will tighten semantics to forbid immediate use of qmp_output_get_qobject() without at least one visit_type_*. Signed-off-by: Eric Blake <eblake@redhat.com> --- v13: no change v12: retitle and merge in output visitor support, move refcount tests to separate file [no v10, v11] v9: new patch --- qapi/qmp-input-visitor.c | 12 ++++++++++++ qapi/qmp-output-visitor.c | 7 +++++++ tests/check-qnull.c | 10 +++++++++- tests/test-qmp-input-visitor.c | 16 ++++++++++++++++ tests/test-qmp-output-visitor.c | 9 +++++---- 5 files changed, 49 insertions(+), 5 deletions(-)