include/qom/object.h: New OBJECT_DEFINE_SIMPLE_TYPE{, _WITH_INTERFACES} macros

We have an OBJECT_DEFINE_TYPE_EXTENDED macro, plus several variations
on it, which emits the boilerplate for the TypeInfo and ensures it is
registered with the type system.  However, all the existing macros
insist that the type being defined has its own FooClass struct, so
they aren't useful for the common case of a simple leaf class which
doesn't have any new methods or any other need for its own class
struct (that is, for the kind of type that OBJECT_DECLARE_SIMPLE_TYPE
declares).

Pull the actual implementation of OBJECT_DEFINE_TYPE_EXTENDED out
into a new DO_OBJECT_DEFINE_TYPE_EXTENDED which parameterizes the
value we use for the class_size field.  This lets us add a new
OBJECT_DEFINE_SIMPLE_TYPE which does the same job as the various
existing OBJECT_DEFINE_*_TYPE_* family macros for this kind of simple
type, and the variant OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES for
when the type will implement some interfaces.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240220160622.114437-5-peter.maydell@linaro.org
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

1 files changed, 79 insertions, 17 deletions

diff --git a/include/qom/object.h b/include/qom/object.h
index e9ed9550f0..13d3a655dd 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -259,31 +259,23 @@ struct Object
 
 
 /**
- * OBJECT_DEFINE_TYPE_EXTENDED:
+ * DO_OBJECT_DEFINE_TYPE_EXTENDED:
  * @ModuleObjName: the object name with initial caps
  * @module_obj_name: the object name in lowercase with underscore separators
  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
  *                          separators
  * @ABSTRACT: boolean flag to indicate whether the object can be instantiated
+ * @CLASS_SIZE: size of the type's class
  * @...: list of initializers for "InterfaceInfo" to declare implemented interfaces
  *
- * This macro is typically used in a source file, and will:
- *
- *   - declare prototypes for _finalize, _class_init and _init methods
- *   - declare the TypeInfo struct instance
- *   - provide the constructor to register the type
- *
- * After using this macro, implementations of the _finalize, _class_init,
- * and _init methods need to be written. Any of these can be zero-line
- * no-op impls if no special logic is required for a given type.
- *
- * This macro should rarely be used, instead one of the more specialized
- * macros is usually a better choice.
+ * This is the base macro used to implement all the OBJECT_DEFINE_*
+ * macros. It should never be used directly in a source file.
  */
-#define OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
-                                    MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
-                                    ABSTRACT, ...) \
+#define DO_OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                       MODULE_OBJ_NAME, \
+                                       PARENT_MODULE_OBJ_NAME, \
+                                       ABSTRACT, CLASS_SIZE, ...) \
     static void \
     module_obj_name##_finalize(Object *obj); \
     static void \
@@ -298,7 +290,7 @@ struct Object
         .instance_align = __alignof__(ModuleObjName), \
         .instance_init = module_obj_name##_init, \
         .instance_finalize = module_obj_name##_finalize, \
-        .class_size = sizeof(ModuleObjName##Class), \
+        .class_size = CLASS_SIZE, \
         .class_init = module_obj_name##_class_init, \
         .abstract = ABSTRACT, \
         .interfaces = (InterfaceInfo[]) { __VA_ARGS__ } , \
@@ -312,6 +304,37 @@ struct Object
     type_init(module_obj_name##_register_types);
 
 /**
+ * OBJECT_DEFINE_TYPE_EXTENDED:
+ * @ModuleObjName: the object name with initial caps
+ * @module_obj_name: the object name in lowercase with underscore separators
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
+ *                          separators
+ * @ABSTRACT: boolean flag to indicate whether the object can be instantiated
+ * @...: list of initializers for "InterfaceInfo" to declare implemented interfaces
+ *
+ * This macro is typically used in a source file, and will:
+ *
+ *   - declare prototypes for _finalize, _class_init and _init methods
+ *   - declare the TypeInfo struct instance
+ *   - provide the constructor to register the type
+ *
+ * After using this macro, implementations of the _finalize, _class_init,
+ * and _init methods need to be written. Any of these can be zero-line
+ * no-op impls if no special logic is required for a given type.
+ *
+ * This macro should rarely be used, instead one of the more specialized
+ * macros is usually a better choice.
+ */
+#define OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                    MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
+                                    ABSTRACT, ...) \
+    DO_OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                   MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
+                                   ABSTRACT, sizeof(ModuleObjName##Class), \
+                                   __VA_ARGS__)
+
+/**
  * OBJECT_DEFINE_TYPE:
  * @ModuleObjName: the object name with initial caps
  * @module_obj_name: the object name in lowercase with underscore separators
@@ -369,6 +392,45 @@ struct Object
                                 true, { NULL })
 
 /**
+ * OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES:
+ * @ModuleObjName: the object name with initial caps
+ * @module_obj_name: the object name in lowercase with underscore separators
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
+ *                          separators
+ *
+ * This is a variant of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable for
+ * the case of a non-abstract type, with interfaces, and with no requirement
+ * for a class struct.
+ */
+#define OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(ModuleObjName, \
+                                                  module_obj_name, \
+                                                  MODULE_OBJ_NAME, \
+                                                  PARENT_MODULE_OBJ_NAME, ...) \
+    DO_OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                   MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
+                                   false, 0, __VA_ARGS__)
+
+/**
+ * OBJECT_DEFINE_SIMPLE_TYPE:
+ * @ModuleObjName: the object name with initial caps
+ * @module_obj_name: the object name in lowercase with underscore separators
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
+ *                          separators
+ *
+ * This is a variant of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable for
+ * the common case of a non-abstract type, without any interfaces, and with
+ * no requirement for a class struct. If you declared your type with
+ * OBJECT_DECLARE_SIMPLE_TYPE then this is probably the right choice for
+ * defining it.
+ */
+#define OBJECT_DEFINE_SIMPLE_TYPE(ModuleObjName, module_obj_name, \
+                                  MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME) \
+    OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(ModuleObjName, module_obj_name, \
+        MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, { NULL })
+
+/**
  * struct TypeInfo:
  * @name: The name of the type.
  * @parent: The name of the parent type.