tests: add /qdev/free-properties test

Add a simple qdev test to check that allocated properties get freed with
the object. This test exhibited array leaks before the fixes.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Link: https://lore.kernel.org/r/20250429140306.190384-6-marcandre.lureau@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://lore.kernel.org/r/20260108230311.584141-6-csomani@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tests/unit/meson.build

@@ -156,6 +156,7 @@ if have_system
       'test-qdev-global-props': [qom, hwcore]
     }
   endif
+  tests += {'test-qdev': [qom, hwcore]}
 endif
 
 if have_ga and host_os == 'linux'

tests/unit/test-qdev.c

@@ -0,0 +1,96 @@
+#include "qemu/osdep.h"
+#include "hw/core/qdev-properties.h"
+#include "qom/object.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
+
+
+#define TYPE_MY_DEV "my-dev"
+typedef struct MyDev MyDev;
+DECLARE_INSTANCE_CHECKER(MyDev, STATIC_TYPE,
+                         TYPE_MY_DEV)
+
+struct MyDev {
+    DeviceState parent_obj;
+
+    uint32_t prop_u32;
+    char *prop_string;
+    uint32_t *prop_array_u32;
+    uint32_t prop_array_u32_nb;
+};
+
+static const Property my_dev_props[] = {
+    DEFINE_PROP_UINT32("u32", MyDev, prop_u32, 100),
+    DEFINE_PROP_STRING("string", MyDev, prop_string),
+    DEFINE_PROP_ARRAY("array-u32", MyDev, prop_array_u32_nb, prop_array_u32,
+                     qdev_prop_uint32, uint32_t),
+};
+
+static void my_dev_class_init(ObjectClass *oc, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = NULL;
+    device_class_set_props(dc, my_dev_props);
+}
+
+static const TypeInfo my_dev_type_info = {
+    .name = TYPE_MY_DEV,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(MyDev),
+    .class_init = my_dev_class_init,
+};
+
+/*
+ * Initialize a fake machine, being prepared for future tests.
+ *
+ * Realization of anonymous qdev (with no parent object) requires both
+ * the machine object and its "unattached" container to be at least present.
+ */
+static void test_init_machine(void)
+{
+    /* This is a fake machine - it doesn't need to be a machine object */
+    Object *machine = object_property_add_new_container(
+        object_get_root(), "machine");
+
+    /* This container must exist for anonymous qdevs to realize() */
+    object_property_add_new_container(machine, "unattached");
+}
+
+static void test_qdev_free_properties(void)
+{
+    MyDev *mt;
+
+    mt = STATIC_TYPE(object_new(TYPE_MY_DEV));
+    object_set_props(OBJECT(mt), &error_fatal,
+                     "string", "something",
+                     "array-u32", "12,13",
+                     NULL);
+    qdev_realize(DEVICE(mt), NULL, &error_fatal);
+
+    g_assert_cmpuint(mt->prop_u32, ==, 100);
+    g_assert_cmpstr(mt->prop_string, ==, "something");
+    g_assert_cmpuint(mt->prop_array_u32_nb, ==, 2);
+    g_assert_cmpuint(mt->prop_array_u32[0], ==, 12);
+    g_assert_cmpuint(mt->prop_array_u32[1], ==, 13);
+
+    object_unparent(OBJECT(mt));
+    object_unref(mt);
+}
+
+
+int main(int argc, char **argv)
+{
+    g_test_init(&argc, &argv, NULL);
+
+    module_call_init(MODULE_INIT_QOM);
+    type_register_static(&my_dev_type_info);
+    test_init_machine();
+
+    g_test_add_func("/qdev/free-properties",
+                    test_qdev_free_properties);
+
+    g_test_run();
+
+    return 0;
+}