object: add class property initializer

This callback is used to set default value in following patch "object:
add object_property_set_defaut_{bool,str,int,uint}()".

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/qom/object.h

@@ -309,6 +309,8 @@ typedef struct InterfaceInfo InterfaceInfo;
  */
 
 
+typedef struct ObjectProperty ObjectProperty;
+
 /**
  * ObjectPropertyAccessor:
  * @obj: the object that owns the property
@@ -356,7 +358,16 @@ typedef void (ObjectPropertyRelease)(Object *obj,
                                      const char *name,
                                      void *opaque);
 
-typedef struct ObjectProperty
+/**
+ * ObjectPropertyInit:
+ * @obj: the object that owns the property
+ * @prop: the property to set
+ *
+ * Called when a property is initialized.
+ */
+typedef void (ObjectPropertyInit)(Object *obj, ObjectProperty *prop);
+
+struct ObjectProperty
 {
     gchar *name;
     gchar *type;
@@ -365,8 +376,9 @@ typedef struct ObjectProperty
     ObjectPropertyAccessor *set;
     ObjectPropertyResolve *resolve;
     ObjectPropertyRelease *release;
+    ObjectPropertyInit *init;
     void *opaque;
-} ObjectProperty;
+};
 
 /**
  * ObjectUnparent:

qom/object.c

@@ -478,6 +478,19 @@ void object_apply_compat_props(Object *obj)
     }
 }
 
+static void object_class_property_init_all(Object *obj)
+{
+    ObjectPropertyIterator iter;
+    ObjectProperty *prop;
+
+    object_class_property_iter_init(&iter, object_get_class(obj));
+    while ((prop = object_property_iter_next(&iter))) {
+        if (prop->init) {
+            prop->init(obj, prop);
+        }
+    }
+}
+
 static void object_initialize_with_type(void *data, size_t size, TypeImpl *type)
 {
     Object *obj = data;
@@ -491,6 +504,7 @@ static void object_initialize_with_type(void *data, size_t size, TypeImpl *type)
     memset(obj, 0, type->instance_size);
     obj->class = type->class;
     object_ref(obj);
+    object_class_property_init_all(obj);
     obj->properties = g_hash_table_new_full(g_str_hash, g_str_equal,
                                             NULL, object_property_free);
     object_init_with_type(obj, type);