xref: /qemu/include/qom/object.h (revision f0737158b483e7ec2b2512145aeab888b85cc1f7)
1 /*
2  * QEMU Object Model
3  *
4  * Copyright IBM, Corp. 2011
5  *
6  * Authors:
7  *  Anthony Liguori   <aliguori@us.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  *
12  */
13 
14 #ifndef QEMU_OBJECT_H
15 #define QEMU_OBJECT_H
16 
17 #include "qapi/qapi-builtin-types.h"
18 #include "qemu/module.h"
19 
20 struct TypeImpl;
21 typedef struct TypeImpl *Type;
22 
23 typedef struct TypeInfo TypeInfo;
24 
25 typedef struct InterfaceClass InterfaceClass;
26 typedef struct InterfaceInfo InterfaceInfo;
27 
28 #define TYPE_OBJECT "object"
29 #define TYPE_CONTAINER "container"
30 
31 typedef struct ObjectProperty ObjectProperty;
32 
33 /**
34  * typedef ObjectPropertyAccessor:
35  * @obj: the object that owns the property
36  * @v: the visitor that contains the property data
37  * @name: the name of the property
38  * @opaque: the object property opaque
39  * @errp: a pointer to an Error that is filled if getting/setting fails.
40  *
41  * Called when trying to get/set a property.
42  */
43 typedef void (ObjectPropertyAccessor)(Object *obj,
44                                       Visitor *v,
45                                       const char *name,
46                                       void *opaque,
47                                       Error **errp);
48 
49 /**
50  * typedef ObjectPropertyResolve:
51  * @obj: the object that owns the property
52  * @opaque: the opaque registered with the property
53  * @part: the name of the property
54  *
55  * Resolves the #Object corresponding to property @part.
56  *
57  * The returned object can also be used as a starting point
58  * to resolve a relative path starting with "@part".
59  *
60  * Returns: If @path is the path that led to @obj, the function
61  * returns the #Object corresponding to "@path/@part".
62  * If "@path/@part" is not a valid object path, it returns #NULL.
63  */
64 typedef Object *(ObjectPropertyResolve)(Object *obj,
65                                         void *opaque,
66                                         const char *part);
67 
68 /**
69  * typedef ObjectPropertyRelease:
70  * @obj: the object that owns the property
71  * @name: the name of the property
72  * @opaque: the opaque registered with the property
73  *
74  * Called when a property is removed from a object.
75  */
76 typedef void (ObjectPropertyRelease)(Object *obj,
77                                      const char *name,
78                                      void *opaque);
79 
80 /**
81  * typedef ObjectPropertyInit:
82  * @obj: the object that owns the property
83  * @prop: the property to set
84  *
85  * Called when a property is initialized.
86  */
87 typedef void (ObjectPropertyInit)(Object *obj, ObjectProperty *prop);
88 
89 struct ObjectProperty
90 {
91     char *name;
92     char *type;
93     char *description;
94     ObjectPropertyAccessor *get;
95     ObjectPropertyAccessor *set;
96     ObjectPropertyResolve *resolve;
97     ObjectPropertyRelease *release;
98     ObjectPropertyInit *init;
99     void *opaque;
100     QObject *defval;
101 };
102 
103 /**
104  * typedef ObjectUnparent:
105  * @obj: the object that is being removed from the composition tree
106  *
107  * Called when an object is being removed from the QOM composition tree.
108  * The function should remove any backlinks from children objects to @obj.
109  */
110 typedef void (ObjectUnparent)(Object *obj);
111 
112 /**
113  * typedef ObjectFree:
114  * @obj: the object being freed
115  *
116  * Called when an object's last reference is removed.
117  */
118 typedef void (ObjectFree)(void *obj);
119 
120 #define OBJECT_CLASS_CAST_CACHE 4
121 
122 /**
123  * struct ObjectClass:
124  *
125  * The base for all classes.  The only thing that #ObjectClass contains is an
126  * integer type handle.
127  */
128 struct ObjectClass
129 {
130     /* private: */
131     Type type;
132     GSList *interfaces;
133 
134     const char *object_cast_cache[OBJECT_CLASS_CAST_CACHE];
135     const char *class_cast_cache[OBJECT_CLASS_CAST_CACHE];
136 
137     ObjectUnparent *unparent;
138 
139     GHashTable *properties;
140 };
141 
142 /**
143  * struct Object:
144  *
145  * The base for all objects.  The first member of this object is a pointer to
146  * a #ObjectClass.  Since C guarantees that the first member of a structure
147  * always begins at byte 0 of that structure, as long as any sub-object places
148  * its parent as the first member, we can cast directly to a #Object.
149  *
150  * As a result, #Object contains a reference to the objects type as its
151  * first member.  This allows identification of the real type of the object at
152  * run time.
153  */
154 struct Object
155 {
156     /* private: */
157     ObjectClass *class;
158     ObjectFree *free;
159     GHashTable *properties;
160     uint32_t ref;
161     Object *parent;
162 };
163 
164 /**
165  * DECLARE_INSTANCE_CHECKER:
166  * @InstanceType: instance struct name
167  * @OBJ_NAME: the object name in uppercase with underscore separators
168  * @TYPENAME: type name
169  *
170  * Direct usage of this macro should be avoided, and the complete
171  * OBJECT_DECLARE_TYPE macro is recommended instead.
172  *
173  * This macro will provide the instance type cast functions for a
174  * QOM type.
175  */
176 #define DECLARE_INSTANCE_CHECKER(InstanceType, OBJ_NAME, TYPENAME) \
177     static inline G_GNUC_UNUSED InstanceType * \
178     OBJ_NAME(const void *obj) \
179     { return OBJECT_CHECK(InstanceType, obj, TYPENAME); }
180 
181 /**
182  * DECLARE_CLASS_CHECKERS:
183  * @ClassType: class struct name
184  * @OBJ_NAME: the object name in uppercase with underscore separators
185  * @TYPENAME: type name
186  *
187  * Direct usage of this macro should be avoided, and the complete
188  * OBJECT_DECLARE_TYPE macro is recommended instead.
189  *
190  * This macro will provide the class type cast functions for a
191  * QOM type.
192  */
193 #define DECLARE_CLASS_CHECKERS(ClassType, OBJ_NAME, TYPENAME) \
194     static inline G_GNUC_UNUSED ClassType * \
195     OBJ_NAME##_GET_CLASS(const void *obj) \
196     { return OBJECT_GET_CLASS(ClassType, obj, TYPENAME); } \
197     \
198     static inline G_GNUC_UNUSED ClassType * \
199     OBJ_NAME##_CLASS(const void *klass) \
200     { return OBJECT_CLASS_CHECK(ClassType, klass, TYPENAME); }
201 
202 /**
203  * DECLARE_OBJ_CHECKERS:
204  * @InstanceType: instance struct name
205  * @ClassType: class struct name
206  * @OBJ_NAME: the object name in uppercase with underscore separators
207  * @TYPENAME: type name
208  *
209  * Direct usage of this macro should be avoided, and the complete
210  * OBJECT_DECLARE_TYPE macro is recommended instead.
211  *
212  * This macro will provide the three standard type cast functions for a
213  * QOM type.
214  */
215 #define DECLARE_OBJ_CHECKERS(InstanceType, ClassType, OBJ_NAME, TYPENAME) \
216     DECLARE_INSTANCE_CHECKER(InstanceType, OBJ_NAME, TYPENAME) \
217     \
218     DECLARE_CLASS_CHECKERS(ClassType, OBJ_NAME, TYPENAME)
219 
220 /**
221  * OBJECT_DECLARE_TYPE:
222  * @InstanceType: instance struct name
223  * @ClassType: class struct name
224  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
225  *
226  * This macro is typically used in a header file, and will:
227  *
228  *   - create the typedefs for the object and class structs
229  *   - register the type for use with g_autoptr
230  *   - provide three standard type cast functions
231  *
232  * The object struct and class struct need to be declared manually.
233  */
234 #define OBJECT_DECLARE_TYPE(InstanceType, ClassType, MODULE_OBJ_NAME) \
235     typedef struct InstanceType InstanceType; \
236     typedef struct ClassType ClassType; \
237     \
238     G_DEFINE_AUTOPTR_CLEANUP_FUNC(InstanceType, object_unref) \
239     \
240     DECLARE_OBJ_CHECKERS(InstanceType, ClassType, \
241                          MODULE_OBJ_NAME, TYPE_##MODULE_OBJ_NAME)
242 
243 /**
244  * OBJECT_DECLARE_SIMPLE_TYPE:
245  * @InstanceType: instance struct name
246  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
247  *
248  * This does the same as OBJECT_DECLARE_TYPE(), but with no class struct
249  * declared.
250  *
251  * This macro should be used unless the class struct needs to have
252  * virtual methods declared.
253  */
254 #define OBJECT_DECLARE_SIMPLE_TYPE(InstanceType, MODULE_OBJ_NAME) \
255     typedef struct InstanceType InstanceType; \
256     \
257     G_DEFINE_AUTOPTR_CLEANUP_FUNC(InstanceType, object_unref) \
258     \
259     DECLARE_INSTANCE_CHECKER(InstanceType, MODULE_OBJ_NAME, TYPE_##MODULE_OBJ_NAME)
260 
261 
262 /**
263  * DO_OBJECT_DEFINE_TYPE_EXTENDED:
264  * @ModuleObjName: the object name with initial caps
265  * @module_obj_name: the object name in lowercase with underscore separators
266  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
267  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
268  *                          separators
269  * @ABSTRACT: boolean flag to indicate whether the object can be instantiated
270  * @CLASS_SIZE: size of the type's class
271  * @...: list of initializers for "InterfaceInfo" to declare implemented interfaces
272  *
273  * This is the base macro used to implement all the OBJECT_DEFINE_*
274  * macros. It should never be used directly in a source file.
275  */
276 #define DO_OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
277                                        MODULE_OBJ_NAME, \
278                                        PARENT_MODULE_OBJ_NAME, \
279                                        ABSTRACT, CLASS_SIZE, ...) \
280     static void \
281     module_obj_name##_finalize(Object *obj); \
282     static void \
283     module_obj_name##_class_init(ObjectClass *oc, const void *data); \
284     static void \
285     module_obj_name##_init(Object *obj); \
286     \
287     static const TypeInfo module_obj_name##_info = { \
288         .parent = TYPE_##PARENT_MODULE_OBJ_NAME, \
289         .name = TYPE_##MODULE_OBJ_NAME, \
290         .instance_size = sizeof(ModuleObjName), \
291         .instance_align = __alignof__(ModuleObjName), \
292         .instance_init = module_obj_name##_init, \
293         .instance_finalize = module_obj_name##_finalize, \
294         .class_size = CLASS_SIZE, \
295         .class_init = module_obj_name##_class_init, \
296         .abstract = ABSTRACT, \
297         .interfaces = (const InterfaceInfo[]) { __VA_ARGS__ } , \
298     }; \
299     \
300     static void \
301     module_obj_name##_register_types(void) \
302     { \
303         type_register_static(&module_obj_name##_info); \
304     } \
305     type_init(module_obj_name##_register_types);
306 
307 /**
308  * OBJECT_DEFINE_TYPE_EXTENDED:
309  * @ModuleObjName: the object name with initial caps
310  * @module_obj_name: the object name in lowercase with underscore separators
311  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
312  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
313  *                          separators
314  * @ABSTRACT: boolean flag to indicate whether the object can be instantiated
315  * @...: list of initializers for "InterfaceInfo" to declare implemented interfaces
316  *
317  * This macro is typically used in a source file, and will:
318  *
319  *   - declare prototypes for _finalize, _class_init and _init methods
320  *   - declare the TypeInfo struct instance
321  *   - provide the constructor to register the type
322  *
323  * After using this macro, implementations of the _finalize, _class_init,
324  * and _init methods need to be written. Any of these can be zero-line
325  * no-op impls if no special logic is required for a given type.
326  *
327  * This macro should rarely be used, instead one of the more specialized
328  * macros is usually a better choice.
329  */
330 #define OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
331                                     MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
332                                     ABSTRACT, ...) \
333     DO_OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
334                                    MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
335                                    ABSTRACT, sizeof(ModuleObjName##Class), \
336                                    __VA_ARGS__)
337 
338 /**
339  * OBJECT_DEFINE_TYPE:
340  * @ModuleObjName: the object name with initial caps
341  * @module_obj_name: the object name in lowercase with underscore separators
342  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
343  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
344  *                          separators
345  *
346  * This is a specialization of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable
347  * for the common case of a non-abstract type, without any interfaces.
348  */
349 #define OBJECT_DEFINE_TYPE(ModuleObjName, module_obj_name, MODULE_OBJ_NAME, \
350                            PARENT_MODULE_OBJ_NAME) \
351     OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
352                                 MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
353                                 false, { NULL })
354 
355 /**
356  * OBJECT_DEFINE_TYPE_WITH_INTERFACES:
357  * @ModuleObjName: the object name with initial caps
358  * @module_obj_name: the object name in lowercase with underscore separators
359  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
360  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
361  *                          separators
362  * @...: list of initializers for "InterfaceInfo" to declare implemented interfaces
363  *
364  * This is a specialization of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable
365  * for the common case of a non-abstract type, with one or more implemented
366  * interfaces.
367  *
368  * Note when passing the list of interfaces, be sure to include the final
369  * NULL entry, e.g.  { TYPE_USER_CREATABLE }, { NULL }
370  */
371 #define OBJECT_DEFINE_TYPE_WITH_INTERFACES(ModuleObjName, module_obj_name, \
372                                            MODULE_OBJ_NAME, \
373                                            PARENT_MODULE_OBJ_NAME, ...) \
374     OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
375                                 MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
376                                 false, __VA_ARGS__)
377 
378 /**
379  * OBJECT_DEFINE_ABSTRACT_TYPE:
380  * @ModuleObjName: the object name with initial caps
381  * @module_obj_name: the object name in lowercase with underscore separators
382  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
383  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
384  *                          separators
385  *
386  * This is a specialization of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable
387  * for defining an abstract type, without any interfaces.
388  */
389 #define OBJECT_DEFINE_ABSTRACT_TYPE(ModuleObjName, module_obj_name, \
390                                     MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME) \
391     OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
392                                 MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
393                                 true, { NULL })
394 
395 /**
396  * OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES:
397  * @ModuleObjName: the object name with initial caps
398  * @module_obj_name: the object name in lowercase with underscore separators
399  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
400  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
401  *                          separators
402  *
403  * This is a variant of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable for
404  * the case of a non-abstract type, with interfaces, and with no requirement
405  * for a class struct.
406  */
407 #define OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(ModuleObjName, \
408                                                   module_obj_name, \
409                                                   MODULE_OBJ_NAME, \
410                                                   PARENT_MODULE_OBJ_NAME, ...) \
411     DO_OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
412                                    MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
413                                    false, 0, __VA_ARGS__)
414 
415 /**
416  * OBJECT_DEFINE_SIMPLE_TYPE:
417  * @ModuleObjName: the object name with initial caps
418  * @module_obj_name: the object name in lowercase with underscore separators
419  * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
420  * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
421  *                          separators
422  *
423  * This is a variant of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable for
424  * the common case of a non-abstract type, without any interfaces, and with
425  * no requirement for a class struct. If you declared your type with
426  * OBJECT_DECLARE_SIMPLE_TYPE then this is probably the right choice for
427  * defining it.
428  */
429 #define OBJECT_DEFINE_SIMPLE_TYPE(ModuleObjName, module_obj_name, \
430                                   MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME) \
431     OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(ModuleObjName, module_obj_name, \
432         MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, { NULL })
433 
434 /**
435  * struct TypeInfo:
436  * @name: The name of the type.
437  * @parent: The name of the parent type.
438  * @instance_size: The size of the object (derivative of #Object).  If
439  *   @instance_size is 0, then the size of the object will be the size of the
440  *   parent object.
441  * @instance_align: The required alignment of the object.  If @instance_align
442  *   is 0, then normal malloc alignment is sufficient; if non-zero, then we
443  *   must use qemu_memalign for allocation.
444  * @instance_init: This function is called to initialize an object.  The parent
445  *   class will have already been initialized so the type is only responsible
446  *   for initializing its own members.
447  * @instance_post_init: This function is called to finish initialization of
448  *   an object, after all @instance_init functions were called, as well as
449  *   @instance_post_init functions for the parent classes.
450  * @instance_finalize: This function is called during object destruction.  This
451  *   is called before the parent @instance_finalize function has been called.
452  *   An object should only free the members that are unique to its type in this
453  *   function.
454  * @abstract: If this field is true, then the class is considered abstract and
455  *   cannot be directly instantiated.
456  * @class_size: The size of the class object (derivative of #ObjectClass)
457  *   for this object.  If @class_size is 0, then the size of the class will be
458  *   assumed to be the size of the parent class.  This allows a type to avoid
459  *   implementing an explicit class type if they are not adding additional
460  *   virtual functions.
461  * @class_init: This function is called after all parent class initialization
462  *   has occurred to allow a class to set its default virtual method pointers.
463  *   This is also the function to use to override virtual methods from a parent
464  *   class.
465  * @class_base_init: This function is called for all base classes after all
466  *   parent class initialization has occurred, but before the class itself
467  *   is initialized.  This is the function to use to undo the effects of
468  *   memcpy from the parent class to the descendants.
469  * @class_data: Data to pass to the @class_init,
470  *   @class_base_init. This can be useful when building dynamic
471  *   classes.
472  * @interfaces: The list of interfaces associated with this type.  This
473  *   should point to a static array that's terminated with a zero filled
474  *   element.
475  */
476 struct TypeInfo
477 {
478     const char *name;
479     const char *parent;
480 
481     size_t instance_size;
482     size_t instance_align;
483     void (*instance_init)(Object *obj);
484     void (*instance_post_init)(Object *obj);
485     void (*instance_finalize)(Object *obj);
486 
487     bool abstract;
488     size_t class_size;
489 
490     void (*class_init)(ObjectClass *klass, const void *data);
491     void (*class_base_init)(ObjectClass *klass, const void *data);
492     const void *class_data;
493 
494     const InterfaceInfo *interfaces;
495 };
496 
497 /**
498  * OBJECT:
499  * @obj: A derivative of #Object
500  *
501  * Converts an object to a #Object.  Since all objects are #Objects,
502  * this function will always succeed.
503  */
504 #define OBJECT(obj) \
505     ((Object *)(obj))
506 
507 /**
508  * OBJECT_CLASS:
509  * @class: A derivative of #ObjectClass.
510  *
511  * Converts a class to an #ObjectClass.  Since all objects are #Objects,
512  * this function will always succeed.
513  */
514 #define OBJECT_CLASS(class) \
515     ((ObjectClass *)(class))
516 
517 /**
518  * OBJECT_CHECK:
519  * @type: The C type to use for the return value.
520  * @obj: A derivative of @type to cast.
521  * @name: The QOM typename of @type
522  *
523  * A type safe version of @object_dynamic_cast_assert.  Typically each class
524  * will define a macro based on this type to perform type safe dynamic_casts to
525  * this object type.
526  *
527  * If an invalid object is passed to this function, a run time assert will be
528  * generated.
529  */
530 #define OBJECT_CHECK(type, obj, name) \
531     ((type *)object_dynamic_cast_assert(OBJECT(obj), (name), \
532                                         __FILE__, __LINE__, __func__))
533 
534 /**
535  * OBJECT_CLASS_CHECK:
536  * @class_type: The C type to use for the return value.
537  * @class: A derivative class of @class_type to cast.
538  * @name: the QOM typename of @class_type.
539  *
540  * A type safe version of @object_class_dynamic_cast_assert.  This macro is
541  * typically wrapped by each type to perform type safe casts of a class to a
542  * specific class type.
543  */
544 #define OBJECT_CLASS_CHECK(class_type, class, name) \
545     ((class_type *)object_class_dynamic_cast_assert(OBJECT_CLASS(class), (name), \
546                                                __FILE__, __LINE__, __func__))
547 
548 /**
549  * OBJECT_GET_CLASS:
550  * @class: The C type to use for the return value.
551  * @obj: The object to obtain the class for.
552  * @name: The QOM typename of @obj.
553  *
554  * This function will return a specific class for a given object.  Its generally
555  * used by each type to provide a type safe macro to get a specific class type
556  * from an object.
557  */
558 #define OBJECT_GET_CLASS(class, obj, name) \
559     OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
560 
561 /**
562  * struct InterfaceInfo:
563  * @type: The name of the interface.
564  *
565  * The information associated with an interface.
566  */
567 struct InterfaceInfo {
568     const char *type;
569 };
570 
571 /**
572  * struct InterfaceClass:
573  * @parent_class: the base class
574  *
575  * The class for all interfaces.  Subclasses of this class should only add
576  * virtual methods.
577  *
578  * Note that most of the fields of ObjectClass are unused (all except
579  * "type", in fact).  They are only present in InterfaceClass to allow
580  * @object_class_dynamic_cast to work with both regular classes and interfaces.
581  */
582 struct InterfaceClass
583 {
584     ObjectClass parent_class;
585     /* private: */
586     Type interface_type;
587 };
588 
589 #define TYPE_INTERFACE "interface"
590 
591 /**
592  * INTERFACE_CLASS:
593  * @klass: class to cast from
594  * Returns: An #InterfaceClass or raise an error if cast is invalid
595  */
596 #define INTERFACE_CLASS(klass) \
597     OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
598 
599 /**
600  * INTERFACE_CHECK:
601  * @interface: the type to return
602  * @obj: the object to convert to an interface
603  * @name: the interface type name
604  *
605  * Returns: @obj casted to @interface if cast is valid, otherwise raise error.
606  */
607 #define INTERFACE_CHECK(interface, obj, name) \
608     ((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name), \
609                                              __FILE__, __LINE__, __func__))
610 
611 /**
612  * object_new_with_class:
613  * @klass: The class to instantiate.
614  *
615  * This function will initialize a new object using heap allocated memory.
616  * The returned object has a reference count of 1, and will be freed when
617  * the last reference is dropped.
618  *
619  * Returns: The newly allocated and instantiated object.
620  */
621 Object *object_new_with_class(ObjectClass *klass);
622 
623 /**
624  * object_new:
625  * @typename: The name of the type of the object to instantiate.
626  *
627  * This function will initialize a new object using heap allocated memory.
628  * The returned object has a reference count of 1, and will be freed when
629  * the last reference is dropped.
630  *
631  * Returns: The newly allocated and instantiated object.
632  */
633 Object *object_new(const char *typename);
634 
635 /**
636  * object_new_with_props:
637  * @typename:  The name of the type of the object to instantiate.
638  * @parent: the parent object
639  * @id: The unique ID of the object
640  * @errp: pointer to error object
641  * @...: list of property names and values
642  *
643  * This function will initialize a new object using heap allocated memory.
644  * The returned object has a reference count of 1, and will be freed when
645  * the last reference is dropped.
646  *
647  * The @id parameter will be used when registering the object as a
648  * child of @parent in the composition tree.
649  *
650  * The variadic parameters are a list of pairs of (propname, propvalue)
651  * strings. The propname of %NULL indicates the end of the property
652  * list. If the object implements the user creatable interface, the
653  * object will be marked complete once all the properties have been
654  * processed.
655  *
656  * .. code-block:: c
657  *    :caption: Creating an object with properties
658  *
659  *      Error *err = NULL;
660  *      Object *obj;
661  *
662  *      obj = object_new_with_props(TYPE_MEMORY_BACKEND_FILE,
663  *                                  object_get_objects_root(),
664  *                                  "hostmem0",
665  *                                  &err,
666  *                                  "share", "yes",
667  *                                  "mem-path", "/dev/shm/somefile",
668  *                                  "prealloc", "yes",
669  *                                  "size", "1048576",
670  *                                  NULL);
671  *
672  *      if (!obj) {
673  *        error_reportf_err(err, "Cannot create memory backend: ");
674  *      }
675  *
676  * The returned object will have one stable reference maintained
677  * for as long as it is present in the object hierarchy.
678  *
679  * Returns: The newly allocated, instantiated & initialized object.
680  */
681 Object *object_new_with_props(const char *typename,
682                               Object *parent,
683                               const char *id,
684                               Error **errp,
685                               ...) G_GNUC_NULL_TERMINATED;
686 
687 /**
688  * object_new_with_propv:
689  * @typename:  The name of the type of the object to instantiate.
690  * @parent: the parent object
691  * @id: The unique ID of the object
692  * @errp: pointer to error object
693  * @vargs: list of property names and values
694  *
695  * See object_new_with_props() for documentation.
696  */
697 Object *object_new_with_propv(const char *typename,
698                               Object *parent,
699                               const char *id,
700                               Error **errp,
701                               va_list vargs);
702 
703 bool object_apply_global_props(Object *obj, const GPtrArray *props,
704                                Error **errp);
705 void object_set_machine_compat_props(GPtrArray *compat_props);
706 void object_set_accelerator_compat_props(GPtrArray *compat_props);
707 void object_register_sugar_prop(const char *driver, const char *prop,
708                                 const char *value, bool optional);
709 void object_apply_compat_props(Object *obj);
710 
711 /**
712  * object_set_props:
713  * @obj: the object instance to set properties on
714  * @errp: pointer to error object
715  * @...: list of property names and values
716  *
717  * This function will set a list of properties on an existing object
718  * instance.
719  *
720  * The variadic parameters are a list of pairs of (propname, propvalue)
721  * strings. The propname of %NULL indicates the end of the property
722  * list.
723  *
724  * .. code-block:: c
725  *    :caption: Update an object's properties
726  *
727  *      Error *err = NULL;
728  *      Object *obj = ...get / create object...;
729  *
730  *      if (!object_set_props(obj,
731  *                            &err,
732  *                            "share", "yes",
733  *                            "mem-path", "/dev/shm/somefile",
734  *                            "prealloc", "yes",
735  *                            "size", "1048576",
736  *                            NULL)) {
737  *        error_reportf_err(err, "Cannot set properties: ");
738  *      }
739  *
740  * The returned object will have one stable reference maintained
741  * for as long as it is present in the object hierarchy.
742  *
743  * Returns: %true on success, %false on error.
744  */
745 bool object_set_props(Object *obj, Error **errp, ...) G_GNUC_NULL_TERMINATED;
746 
747 /**
748  * object_set_propv:
749  * @obj: the object instance to set properties on
750  * @errp: pointer to error object
751  * @vargs: list of property names and values
752  *
753  * See object_set_props() for documentation.
754  *
755  * Returns: %true on success, %false on error.
756  */
757 bool object_set_propv(Object *obj, Error **errp, va_list vargs);
758 
759 /**
760  * object_initialize:
761  * @obj: A pointer to the memory to be used for the object.
762  * @size: The maximum size available at @obj for the object.
763  * @typename: The name of the type of the object to instantiate.
764  *
765  * This function will initialize an object.  The memory for the object should
766  * have already been allocated.  The returned object has a reference count of 1,
767  * and will be finalized when the last reference is dropped.
768  */
769 void object_initialize(void *obj, size_t size, const char *typename);
770 
771 /**
772  * object_initialize_child_with_props:
773  * @parentobj: The parent object to add a property to
774  * @propname: The name of the property
775  * @childobj: A pointer to the memory to be used for the object.
776  * @size: The maximum size available at @childobj for the object.
777  * @type: The name of the type of the object to instantiate.
778  * @errp: If an error occurs, a pointer to an area to store the error
779  * @...: list of property names and values
780  *
781  * This function will initialize an object. The memory for the object should
782  * have already been allocated. The object will then be added as child property
783  * to a parent with object_property_add_child() function. The returned object
784  * has a reference count of 1 (for the "child<...>" property from the parent),
785  * so the object will be finalized automatically when the parent gets removed.
786  *
787  * The variadic parameters are a list of pairs of (propname, propvalue)
788  * strings. The propname of %NULL indicates the end of the property list.
789  * If the object implements the user creatable interface, the object will
790  * be marked complete once all the properties have been processed.
791  *
792  * Returns: %true on success, %false on failure.
793  */
794 bool object_initialize_child_with_props(Object *parentobj,
795                              const char *propname,
796                              void *childobj, size_t size, const char *type,
797                              Error **errp, ...) G_GNUC_NULL_TERMINATED;
798 
799 /**
800  * object_initialize_child_with_propsv:
801  * @parentobj: The parent object to add a property to
802  * @propname: The name of the property
803  * @childobj: A pointer to the memory to be used for the object.
804  * @size: The maximum size available at @childobj for the object.
805  * @type: The name of the type of the object to instantiate.
806  * @errp: If an error occurs, a pointer to an area to store the error
807  * @vargs: list of property names and values
808  *
809  * See object_initialize_child() for documentation.
810  *
811  * Returns: %true on success, %false on failure.
812  */
813 bool object_initialize_child_with_propsv(Object *parentobj,
814                               const char *propname,
815                               void *childobj, size_t size, const char *type,
816                               Error **errp, va_list vargs);
817 
818 /**
819  * object_initialize_child:
820  * @parent: The parent object to add a property to
821  * @propname: The name of the property
822  * @child: A precisely typed pointer to the memory to be used for the
823  * object.
824  * @type: The name of the type of the object to instantiate.
825  *
826  * This is like::
827  *
828  *   object_initialize_child_with_props(parent, propname,
829  *                                      child, sizeof(*child), type,
830  *                                      &error_abort, NULL)
831  */
832 #define object_initialize_child(parent, propname, child, type)          \
833     object_initialize_child_internal((parent), (propname),              \
834                                      (child), sizeof(*(child)), (type))
835 void object_initialize_child_internal(Object *parent, const char *propname,
836                                       void *child, size_t size,
837                                       const char *type);
838 
839 /**
840  * object_dynamic_cast:
841  * @obj: The object to cast.
842  * @typename: The @typename to cast to.
843  *
844  * This function will determine if @obj is-a @typename.  @obj can refer to an
845  * object or an interface associated with an object.
846  *
847  * Returns: This function returns @obj on success or #NULL on failure.
848  */
849 Object *object_dynamic_cast(Object *obj, const char *typename);
850 
851 /**
852  * object_dynamic_cast_assert:
853  * @obj: The object to cast.
854  * @typename: The @typename to cast to.
855  * @file: Source code file where function was called
856  * @line: Source code line where function was called
857  * @func: Name of function where this function was called
858  *
859  * See object_dynamic_cast() for a description of the parameters of this
860  * function.  The only difference in behavior is that this function asserts
861  * instead of returning #NULL on failure if QOM cast debugging is enabled.
862  * This function is not meant to be called directly, but only through
863  * the wrapper macro OBJECT_CHECK.
864  */
865 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
866                                    const char *file, int line, const char *func);
867 
868 /**
869  * object_get_class:
870  * @obj: A derivative of #Object
871  *
872  * Returns: The #ObjectClass of the type associated with @obj.
873  */
874 ObjectClass *object_get_class(Object *obj);
875 
876 /**
877  * object_get_typename:
878  * @obj: A derivative of #Object.
879  *
880  * Returns: The QOM typename of @obj.
881  */
882 const char *object_get_typename(const Object *obj);
883 
884 /**
885  * type_register_static:
886  * @info: The #TypeInfo of the new type.
887  *
888  * Returns: the new #Type.
889  */
890 Type type_register_static(const TypeInfo *info);
891 
892 /**
893  * type_register_static_array:
894  * @infos: The array of the new type #TypeInfo structures.
895  * @nr_infos: number of entries in @infos
896  *
897  * @infos and all of the strings it points to should exist for the life time
898  * that the type is registered.
899  */
900 void type_register_static_array(const TypeInfo *infos, int nr_infos);
901 
902 /**
903  * DEFINE_TYPES:
904  * @type_array: The array containing #TypeInfo structures to register
905  *
906  * @type_array should be static constant that exists for the life time
907  * that the type is registered.
908  */
909 #define DEFINE_TYPES(type_array)                                            \
910 static void do_qemu_init_ ## type_array(void)                               \
911 {                                                                           \
912     type_register_static_array(type_array, ARRAY_SIZE(type_array));         \
913 }                                                                           \
914 type_init(do_qemu_init_ ## type_array)
915 
916 /**
917  * type_print_class_properties:
918  * @type: a QOM class name
919  *
920  * Print the object's class properties to stdout or the monitor.
921  * Return whether an object was found.
922  */
923 bool type_print_class_properties(const char *type);
924 
925 /**
926  * object_set_properties_from_keyval:
927  * @obj: a QOM object
928  * @qdict: a dictionary with the properties to be set
929  * @from_json: true if leaf values of @qdict are typed, false if they
930  * are strings
931  * @errp: pointer to error object
932  *
933  * For each key in the dictionary, parse the value string if needed,
934  * then set the corresponding property in @obj.
935  */
936 void object_set_properties_from_keyval(Object *obj, const QDict *qdict,
937                                        bool from_json, Error **errp);
938 
939 /**
940  * object_class_dynamic_cast_assert:
941  * @klass: The #ObjectClass to attempt to cast.
942  * @typename: The QOM typename of the class to cast to.
943  * @file: Source code file where function was called
944  * @line: Source code line where function was called
945  * @func: Name of function where this function was called
946  *
947  * See object_class_dynamic_cast() for a description of the parameters
948  * of this function.  The only difference in behavior is that this function
949  * asserts instead of returning #NULL on failure if QOM cast debugging is
950  * enabled.  This function is not meant to be called directly, but only through
951  * the wrapper macro OBJECT_CLASS_CHECK.
952  */
953 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass,
954                                               const char *typename,
955                                               const char *file, int line,
956                                               const char *func);
957 
958 /**
959  * object_class_dynamic_cast:
960  * @klass: The #ObjectClass to attempt to cast.
961  * @typename: The QOM typename of the class to cast to.
962  *
963  * Returns: If @typename is a class, this function returns @klass if
964  * @typename is a subtype of @klass, else returns #NULL.
965  *
966  * If @typename is an interface, this function returns the interface
967  * definition for @klass if @klass implements it unambiguously; #NULL
968  * is returned if @klass does not implement the interface or if multiple
969  * classes or interfaces on the hierarchy leading to @klass implement
970  * it.  (FIXME: perhaps this can be detected at type definition time?)
971  */
972 ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
973                                        const char *typename);
974 
975 /**
976  * object_class_get_parent:
977  * @klass: The class to obtain the parent for.
978  *
979  * Returns: The parent for @klass or %NULL if none.
980  */
981 ObjectClass *object_class_get_parent(ObjectClass *klass);
982 
983 /**
984  * object_class_get_name:
985  * @klass: The class to obtain the QOM typename for.
986  *
987  * Returns: The QOM typename for @klass.
988  */
989 const char *object_class_get_name(ObjectClass *klass);
990 
991 /**
992  * object_class_is_abstract:
993  * @klass: The class to obtain the abstractness for.
994  *
995  * Returns: %true if @klass is abstract, %false otherwise.
996  */
997 bool object_class_is_abstract(ObjectClass *klass);
998 
999 /**
1000  * object_class_by_name:
1001  * @typename: The QOM typename to obtain the class for.
1002  *
1003  * Returns: The class for @typename or %NULL if not found.
1004  */
1005 ObjectClass *object_class_by_name(const char *typename);
1006 
1007 /**
1008  * module_object_class_by_name:
1009  * @typename: The QOM typename to obtain the class for.
1010  *
1011  * For objects which might be provided by a module.  Behaves like
1012  * object_class_by_name, but additionally tries to load the module
1013  * needed in case the class is not available.
1014  *
1015  * Returns: The class for @typename or %NULL if not found.
1016  */
1017 ObjectClass *module_object_class_by_name(const char *typename);
1018 
1019 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
1020                           const char *implements_type, bool include_abstract,
1021                           void *opaque);
1022 
1023 /**
1024  * object_class_get_list:
1025  * @implements_type: The type to filter for, including its derivatives.
1026  * @include_abstract: Whether to include abstract classes.
1027  *
1028  * Returns: A singly-linked list of the classes in reverse hashtable order.
1029  */
1030 GSList *object_class_get_list(const char *implements_type,
1031                               bool include_abstract);
1032 
1033 /**
1034  * object_class_get_list_sorted:
1035  * @implements_type: The type to filter for, including its derivatives.
1036  * @include_abstract: Whether to include abstract classes.
1037  *
1038  * Returns: A singly-linked list of the classes in alphabetical
1039  * case-insensitive order.
1040  */
1041 GSList *object_class_get_list_sorted(const char *implements_type,
1042                               bool include_abstract);
1043 
1044 /**
1045  * object_ref:
1046  * @obj: the object
1047  *
1048  * Increase the reference count of a object.  A object cannot be freed as long
1049  * as its reference count is greater than zero.
1050  * Returns: @obj
1051  */
1052 Object *object_ref(void *obj);
1053 
1054 /**
1055  * object_unref:
1056  * @obj: the object
1057  *
1058  * Decrease the reference count of a object.  A object cannot be freed as long
1059  * as its reference count is greater than zero.
1060  */
1061 void object_unref(void *obj);
1062 
1063 /**
1064  * object_property_try_add:
1065  * @obj: the object to add a property to
1066  * @name: the name of the property.  This can contain any character except for
1067  *  a forward slash.  In general, you should use hyphens '-' instead of
1068  *  underscores '_' when naming properties.
1069  * @type: the type name of the property.  This namespace is pretty loosely
1070  *   defined.  Sub namespaces are constructed by using a prefix and then
1071  *   to angle brackets.  For instance, the type 'virtio-net-pci' in the
1072  *   'link' namespace would be 'link<virtio-net-pci>'.
1073  * @get: The getter to be called to read a property.  If this is NULL, then
1074  *   the property cannot be read.
1075  * @set: the setter to be called to write a property.  If this is NULL,
1076  *   then the property cannot be written.
1077  * @release: called when the property is removed from the object.  This is
1078  *   meant to allow a property to free its opaque upon object
1079  *   destruction.  This may be NULL.
1080  * @opaque: an opaque pointer to pass to the callbacks for the property
1081  * @errp: pointer to error object
1082  *
1083  * Returns: The #ObjectProperty; this can be used to set the @resolve
1084  * callback for child and link properties.
1085  */
1086 ObjectProperty *object_property_try_add(Object *obj, const char *name,
1087                                         const char *type,
1088                                         ObjectPropertyAccessor *get,
1089                                         ObjectPropertyAccessor *set,
1090                                         ObjectPropertyRelease *release,
1091                                         void *opaque, Error **errp);
1092 
1093 /**
1094  * object_property_add:
1095  * Same as object_property_try_add() with @errp hardcoded to
1096  * &error_abort.
1097  *
1098  * @obj: the object to add a property to
1099  * @name: the name of the property.  This can contain any character except for
1100  *  a forward slash.  In general, you should use hyphens '-' instead of
1101  *  underscores '_' when naming properties.
1102  * @type: the type name of the property.  This namespace is pretty loosely
1103  *   defined.  Sub namespaces are constructed by using a prefix and then
1104  *   to angle brackets.  For instance, the type 'virtio-net-pci' in the
1105  *   'link' namespace would be 'link<virtio-net-pci>'.
1106  * @get: The getter to be called to read a property.  If this is NULL, then
1107  *   the property cannot be read.
1108  * @set: the setter to be called to write a property.  If this is NULL,
1109  *   then the property cannot be written.
1110  * @release: called when the property is removed from the object.  This is
1111  *   meant to allow a property to free its opaque upon object
1112  *   destruction.  This may be NULL.
1113  * @opaque: an opaque pointer to pass to the callbacks for the property
1114  */
1115 ObjectProperty *object_property_add(Object *obj, const char *name,
1116                                     const char *type,
1117                                     ObjectPropertyAccessor *get,
1118                                     ObjectPropertyAccessor *set,
1119                                     ObjectPropertyRelease *release,
1120                                     void *opaque);
1121 
1122 void object_property_del(Object *obj, const char *name);
1123 
1124 ObjectProperty *object_class_property_add(ObjectClass *klass, const char *name,
1125                                           const char *type,
1126                                           ObjectPropertyAccessor *get,
1127                                           ObjectPropertyAccessor *set,
1128                                           ObjectPropertyRelease *release,
1129                                           void *opaque);
1130 
1131 /**
1132  * object_property_set_default_bool:
1133  * @prop: the property to set
1134  * @value: the value to be written to the property
1135  *
1136  * Set the property default value.
1137  */
1138 void object_property_set_default_bool(ObjectProperty *prop, bool value);
1139 
1140 /**
1141  * object_property_set_default_str:
1142  * @prop: the property to set
1143  * @value: the value to be written to the property
1144  *
1145  * Set the property default value.
1146  */
1147 void object_property_set_default_str(ObjectProperty *prop, const char *value);
1148 
1149 /**
1150  * object_property_set_default_list:
1151  * @prop: the property to set
1152  *
1153  * Set the property default value to be an empty list.
1154  */
1155 void object_property_set_default_list(ObjectProperty *prop);
1156 
1157 /**
1158  * object_property_set_default_int:
1159  * @prop: the property to set
1160  * @value: the value to be written to the property
1161  *
1162  * Set the property default value.
1163  */
1164 void object_property_set_default_int(ObjectProperty *prop, int64_t value);
1165 
1166 /**
1167  * object_property_set_default_uint:
1168  * @prop: the property to set
1169  * @value: the value to be written to the property
1170  *
1171  * Set the property default value.
1172  */
1173 void object_property_set_default_uint(ObjectProperty *prop, uint64_t value);
1174 
1175 /**
1176  * object_property_find:
1177  * @obj: the object
1178  * @name: the name of the property
1179  *
1180  * Look up a property for an object.
1181  *
1182  * Return its #ObjectProperty if found, or NULL.
1183  */
1184 ObjectProperty *object_property_find(Object *obj, const char *name);
1185 
1186 /**
1187  * object_property_find_err:
1188  * @obj: the object
1189  * @name: the name of the property
1190  * @errp: returns an error if this function fails
1191  *
1192  * Look up a property for an object.
1193  *
1194  * Return its #ObjectProperty if found, or NULL.
1195  */
1196 ObjectProperty *object_property_find_err(Object *obj,
1197                                          const char *name,
1198                                          Error **errp);
1199 
1200 /**
1201  * object_class_property_find:
1202  * @klass: the object class
1203  * @name: the name of the property
1204  *
1205  * Look up a property for an object class.
1206  *
1207  * Return its #ObjectProperty if found, or NULL.
1208  */
1209 ObjectProperty *object_class_property_find(ObjectClass *klass,
1210                                            const char *name);
1211 
1212 /**
1213  * object_class_property_find_err:
1214  * @klass: the object class
1215  * @name: the name of the property
1216  * @errp: returns an error if this function fails
1217  *
1218  * Look up a property for an object class.
1219  *
1220  * Return its #ObjectProperty if found, or NULL.
1221  */
1222 ObjectProperty *object_class_property_find_err(ObjectClass *klass,
1223                                                const char *name,
1224                                                Error **errp);
1225 
1226 typedef struct ObjectPropertyIterator {
1227     ObjectClass *nextclass;
1228     GHashTableIter iter;
1229 } ObjectPropertyIterator;
1230 
1231 /**
1232  * object_property_iter_init:
1233  * @iter: the iterator instance
1234  * @obj: the object
1235  *
1236  * Initializes an iterator for traversing all properties
1237  * registered against an object instance, its class and all parent classes.
1238  *
1239  * It is forbidden to modify the property list while iterating,
1240  * whether removing or adding properties.
1241  *
1242  * Typical usage pattern would be
1243  *
1244  * .. code-block:: c
1245  *    :caption: Using object property iterators
1246  *
1247  *      ObjectProperty *prop;
1248  *      ObjectPropertyIterator iter;
1249  *
1250  *      object_property_iter_init(&iter, obj);
1251  *      while ((prop = object_property_iter_next(&iter))) {
1252  *        ... do something with prop ...
1253  *      }
1254  */
1255 void object_property_iter_init(ObjectPropertyIterator *iter,
1256                                Object *obj);
1257 
1258 /**
1259  * object_class_property_iter_init:
1260  * @iter: the iterator instance
1261  * @klass: the class
1262  *
1263  * Initializes an iterator for traversing all properties
1264  * registered against an object class and all parent classes.
1265  *
1266  * It is forbidden to modify the property list while iterating,
1267  * whether removing or adding properties.
1268  *
1269  * This can be used on abstract classes as it does not create a temporary
1270  * instance.
1271  */
1272 void object_class_property_iter_init(ObjectPropertyIterator *iter,
1273                                      ObjectClass *klass);
1274 
1275 /**
1276  * object_property_iter_next:
1277  * @iter: the iterator instance
1278  *
1279  * Return the next available property. If no further properties
1280  * are available, a %NULL value will be returned and the @iter
1281  * pointer should not be used again after this point without
1282  * re-initializing it.
1283  *
1284  * Returns: the next property, or %NULL when all properties
1285  * have been traversed.
1286  */
1287 ObjectProperty *object_property_iter_next(ObjectPropertyIterator *iter);
1288 
1289 void object_unparent(Object *obj);
1290 
1291 /**
1292  * object_property_get:
1293  * @obj: the object
1294  * @name: the name of the property
1295  * @v: the visitor that will receive the property value.  This should be an
1296  *   Output visitor and the data will be written with @name as the name.
1297  * @errp: returns an error if this function fails
1298  *
1299  * Reads a property from a object.
1300  *
1301  * Returns: %true on success, %false on failure.
1302  */
1303 bool object_property_get(Object *obj, const char *name, Visitor *v,
1304                          Error **errp);
1305 
1306 /**
1307  * object_property_set_str:
1308  * @obj: the object
1309  * @name: the name of the property
1310  * @value: the value to be written to the property
1311  * @errp: returns an error if this function fails
1312  *
1313  * Writes a string value to a property.
1314  *
1315  * Returns: %true on success, %false on failure.
1316  */
1317 bool object_property_set_str(Object *obj, const char *name,
1318                              const char *value, Error **errp);
1319 
1320 /**
1321  * object_property_get_str:
1322  * @obj: the object
1323  * @name: the name of the property
1324  * @errp: returns an error if this function fails
1325  *
1326  * Returns: the value of the property, converted to a C string, or NULL if
1327  * an error occurs (including when the property value is not a string).
1328  * The caller should free the string.
1329  */
1330 char *object_property_get_str(Object *obj, const char *name,
1331                               Error **errp);
1332 
1333 /**
1334  * object_property_set_link:
1335  * @obj: the object
1336  * @name: the name of the property
1337  * @value: the value to be written to the property
1338  * @errp: returns an error if this function fails
1339  *
1340  * Writes an object's canonical path to a property.
1341  *
1342  * If the link property was created with
1343  * %OBJ_PROP_LINK_STRONG bit, the old target object is
1344  * unreferenced, and a reference is added to the new target object.
1345  *
1346  * Returns: %true on success, %false on failure.
1347  */
1348 bool object_property_set_link(Object *obj, const char *name,
1349                               Object *value, Error **errp);
1350 
1351 /**
1352  * object_property_get_link:
1353  * @obj: the object
1354  * @name: the name of the property
1355  * @errp: returns an error if this function fails
1356  *
1357  * Returns: the value of the property, resolved from a path to an Object,
1358  * or NULL if an error occurs (including when the property value is not a
1359  * string or not a valid object path).
1360  */
1361 Object *object_property_get_link(Object *obj, const char *name,
1362                                  Error **errp);
1363 
1364 /**
1365  * object_property_set_bool:
1366  * @obj: the object
1367  * @name: the name of the property
1368  * @value: the value to be written to the property
1369  * @errp: returns an error if this function fails
1370  *
1371  * Writes a bool value to a property.
1372  *
1373  * Returns: %true on success, %false on failure.
1374  */
1375 bool object_property_set_bool(Object *obj, const char *name,
1376                               bool value, Error **errp);
1377 
1378 /**
1379  * object_property_get_bool:
1380  * @obj: the object
1381  * @name: the name of the property
1382  * @errp: returns an error if this function fails
1383  *
1384  * Returns: the value of the property, converted to a boolean, or false if
1385  * an error occurs (including when the property value is not a bool).
1386  */
1387 bool object_property_get_bool(Object *obj, const char *name,
1388                               Error **errp);
1389 
1390 /**
1391  * object_property_set_int:
1392  * @obj: the object
1393  * @name: the name of the property
1394  * @value: the value to be written to the property
1395  * @errp: returns an error if this function fails
1396  *
1397  * Writes an integer value to a property.
1398  *
1399  * Returns: %true on success, %false on failure.
1400  */
1401 bool object_property_set_int(Object *obj, const char *name,
1402                              int64_t value, Error **errp);
1403 
1404 /**
1405  * object_property_get_int:
1406  * @obj: the object
1407  * @name: the name of the property
1408  * @errp: returns an error if this function fails
1409  *
1410  * Returns: the value of the property, converted to an integer, or -1 if
1411  * an error occurs (including when the property value is not an integer).
1412  */
1413 int64_t object_property_get_int(Object *obj, const char *name,
1414                                 Error **errp);
1415 
1416 /**
1417  * object_property_set_uint:
1418  * @obj: the object
1419  * @name: the name of the property
1420  * @value: the value to be written to the property
1421  * @errp: returns an error if this function fails
1422  *
1423  * Writes an unsigned integer value to a property.
1424  *
1425  * Returns: %true on success, %false on failure.
1426  */
1427 bool object_property_set_uint(Object *obj, const char *name,
1428                               uint64_t value, Error **errp);
1429 
1430 /**
1431  * object_property_get_uint:
1432  * @obj: the object
1433  * @name: the name of the property
1434  * @errp: returns an error if this function fails
1435  *
1436  * Returns: the value of the property, converted to an unsigned integer, or 0
1437  * an error occurs (including when the property value is not an integer).
1438  */
1439 uint64_t object_property_get_uint(Object *obj, const char *name,
1440                                   Error **errp);
1441 
1442 /**
1443  * object_property_get_enum:
1444  * @obj: the object
1445  * @name: the name of the property
1446  * @typename: the name of the enum data type
1447  * @errp: returns an error if this function fails
1448  *
1449  * Returns: the value of the property, converted to an integer (which
1450  * can't be negative), or -1 on error (including when the property
1451  * value is not an enum).
1452  */
1453 int object_property_get_enum(Object *obj, const char *name,
1454                              const char *typename, Error **errp);
1455 
1456 /**
1457  * object_property_set:
1458  * @obj: the object
1459  * @name: the name of the property
1460  * @v: the visitor that will be used to write the property value.  This should
1461  *   be an Input visitor and the data will be first read with @name as the
1462  *   name and then written as the property value.
1463  * @errp: returns an error if this function fails
1464  *
1465  * Writes a property to a object.
1466  *
1467  * Returns: %true on success, %false on failure.
1468  */
1469 bool object_property_set(Object *obj, const char *name, Visitor *v,
1470                          Error **errp);
1471 
1472 /**
1473  * object_property_parse:
1474  * @obj: the object
1475  * @name: the name of the property
1476  * @string: the string that will be used to parse the property value.
1477  * @errp: returns an error if this function fails
1478  *
1479  * Parses a string and writes the result into a property of an object.
1480  *
1481  * Returns: %true on success, %false on failure.
1482  */
1483 bool object_property_parse(Object *obj, const char *name,
1484                            const char *string, Error **errp);
1485 
1486 /**
1487  * object_property_print:
1488  * @obj: the object
1489  * @name: the name of the property
1490  * @human: if true, print for human consumption
1491  * @errp: returns an error if this function fails
1492  *
1493  * Returns a string representation of the value of the property.  The
1494  * caller shall free the string.
1495  */
1496 char *object_property_print(Object *obj, const char *name, bool human,
1497                             Error **errp);
1498 
1499 /**
1500  * object_property_get_type:
1501  * @obj: the object
1502  * @name: the name of the property
1503  * @errp: returns an error if this function fails
1504  *
1505  * Returns:  The type name of the property.
1506  */
1507 const char *object_property_get_type(Object *obj, const char *name,
1508                                      Error **errp);
1509 
1510 /**
1511  * object_get_root:
1512  *
1513  * Returns: the root object of the composition tree
1514  */
1515 Object *object_get_root(void);
1516 
1517 /**
1518  * object_get_container:
1519  * @name: the name of container to lookup
1520  *
1521  * Lookup a root level container.
1522  *
1523  * Returns: the container with @name.
1524  */
1525 Object *object_get_container(const char *name);
1526 
1527 
1528 /**
1529  * object_get_objects_root:
1530  *
1531  * Get the container object that holds user created
1532  * object instances. This is the object at path
1533  * "/objects"
1534  *
1535  * Returns: the user object container
1536  */
1537 Object *object_get_objects_root(void);
1538 
1539 /**
1540  * object_get_internal_root:
1541  *
1542  * Get the container object that holds internally used object
1543  * instances.  Any object which is put into this container must not be
1544  * user visible, and it will not be exposed in the QOM tree.
1545  *
1546  * Returns: the internal object container
1547  */
1548 Object *object_get_internal_root(void);
1549 
1550 /**
1551  * object_get_canonical_path_component:
1552  * @obj: the object
1553  *
1554  * Returns: The final component in the object's canonical path.  The canonical
1555  * path is the path within the composition tree starting from the root.
1556  * %NULL if the object doesn't have a parent (and thus a canonical path).
1557  */
1558 const char *object_get_canonical_path_component(const Object *obj);
1559 
1560 /**
1561  * object_get_canonical_path:
1562  * @obj: the object
1563  *
1564  * Returns: The canonical path for a object, newly allocated.  This is
1565  * the path within the composition tree starting from the root.  Use
1566  * g_free() to free it.
1567  */
1568 char *object_get_canonical_path(const Object *obj);
1569 
1570 /**
1571  * object_resolve_path:
1572  * @path: the path to resolve
1573  * @ambiguous: (out) (optional): location to store whether the lookup failed
1574  *   because it was ambiguous, or %NULL. Set to %false on success.
1575  *
1576  * There are two types of supported paths--absolute paths and partial paths.
1577  *
1578  * Absolute paths are derived from the root object and can follow child<> or
1579  * link<> properties.  Since they can follow link<> properties, they can be
1580  * arbitrarily long.  Absolute paths look like absolute filenames and are
1581  * prefixed with a leading slash.
1582  *
1583  * Partial paths look like relative filenames.  They do not begin with a
1584  * prefix.  The matching rules for partial paths are subtle but designed to make
1585  * specifying objects easy.  At each level of the composition tree, the partial
1586  * path is matched as an absolute path.  The first match is not returned.  At
1587  * least two matches are searched for.  A successful result is only returned if
1588  * only one match is found.  If more than one match is found, a flag is
1589  * returned to indicate that the match was ambiguous.
1590  *
1591  * Returns: The matched object or %NULL on path lookup failure.
1592  */
1593 Object *object_resolve_path(const char *path, bool *ambiguous);
1594 
1595 /**
1596  * object_resolve_path_type:
1597  * @path: the path to resolve
1598  * @typename: the type to look for.
1599  * @ambiguous: (out) (optional): location to store whether the lookup failed
1600  *   because it was ambiguous, or %NULL. Set to %false on success.
1601  *
1602  * This is similar to object_resolve_path().  However, when looking for a
1603  * partial path only matches that implement the given type are considered.
1604  * This restricts the search and avoids spuriously flagging matches as
1605  * ambiguous.
1606  *
1607  * For both partial and absolute paths, the return value goes through
1608  * a dynamic cast to @typename.  This is important if either the link,
1609  * or the typename itself are of interface types.
1610  *
1611  * Returns: The matched object or NULL on path lookup failure.
1612  */
1613 Object *object_resolve_path_type(const char *path, const char *typename,
1614                                  bool *ambiguous);
1615 
1616 /**
1617  * object_resolve_type_unambiguous:
1618  * @typename: the type to look for
1619  * @errp: pointer to error object
1620  *
1621  * Return the only object in the QOM tree of type @typename.
1622  * If no match or more than one match is found, an error is
1623  * returned.
1624  *
1625  * Returns: The matched object or NULL on path lookup failure.
1626  */
1627 Object *object_resolve_type_unambiguous(const char *typename, Error **errp);
1628 
1629 /**
1630  * object_resolve_path_at:
1631  * @parent: the object in which to resolve the path
1632  * @path: the path to resolve
1633  *
1634  * This is like object_resolve_path(), except paths not starting with
1635  * a slash are relative to @parent.
1636  *
1637  * Returns: The resolved object or NULL on path lookup failure.
1638  */
1639 Object *object_resolve_path_at(Object *parent, const char *path);
1640 
1641 /**
1642  * object_resolve_path_component:
1643  * @parent: the object in which to resolve the path
1644  * @part: the component to resolve.
1645  *
1646  * This is similar to object_resolve_path with an absolute path, but it
1647  * only resolves one element (@part) and takes the others from @parent.
1648  *
1649  * Returns: The resolved object or NULL on path lookup failure.
1650  */
1651 Object *object_resolve_path_component(Object *parent, const char *part);
1652 
1653 /**
1654  * object_property_try_add_child:
1655  * @obj: the object to add a property to
1656  * @name: the name of the property
1657  * @child: the child object
1658  * @errp: pointer to error object
1659  *
1660  * Child properties form the composition tree.  All objects need to be a child
1661  * of another object.  Objects can only be a child of one object.
1662  *
1663  * There is no way for a child to determine what its parent is.  It is not
1664  * a bidirectional relationship.  This is by design.
1665  *
1666  * The value of a child property as a C string will be the child object's
1667  * canonical path. It can be retrieved using object_property_get_str().
1668  * The child object itself can be retrieved using object_property_get_link().
1669  *
1670  * Returns: The newly added property on success, or %NULL on failure.
1671  */
1672 ObjectProperty *object_property_try_add_child(Object *obj, const char *name,
1673                                               Object *child, Error **errp);
1674 
1675 /**
1676  * object_property_add_child:
1677  * @obj: the object to add a property to
1678  * @name: the name of the property
1679  * @child: the child object
1680  *
1681  * Same as object_property_try_add_child() with @errp hardcoded to
1682  * &error_abort
1683  */
1684 ObjectProperty *object_property_add_child(Object *obj, const char *name,
1685                                           Object *child);
1686 
1687 typedef enum {
1688     /* Unref the link pointer when the property is deleted */
1689     OBJ_PROP_LINK_STRONG = 0x1,
1690 
1691     /* private */
1692     OBJ_PROP_LINK_DIRECT = 0x2,
1693     OBJ_PROP_LINK_CLASS = 0x4,
1694 } ObjectPropertyLinkFlags;
1695 
1696 /**
1697  * object_property_allow_set_link:
1698  * @obj: the object to add a property to
1699  * @name: the name of the property
1700  * @child: the child object
1701  * @errp: pointer to error object
1702  *
1703  * The default implementation of the object_property_add_link() check()
1704  * callback function.  It allows the link property to be set and never returns
1705  * an error.
1706  */
1707 void object_property_allow_set_link(const Object *obj, const char *name,
1708                                     Object *child, Error **errp);
1709 
1710 /**
1711  * object_property_add_link:
1712  * @obj: the object to add a property to
1713  * @name: the name of the property
1714  * @type: the qobj type of the link
1715  * @targetp: a pointer to where the link object reference is stored
1716  * @check: callback to veto setting or NULL if the property is read-only
1717  * @flags: additional options for the link
1718  *
1719  * Links establish relationships between objects.  Links are unidirectional
1720  * although two links can be combined to form a bidirectional relationship
1721  * between objects.
1722  *
1723  * Links form the graph in the object model.
1724  *
1725  * The @check() callback is invoked when
1726  * object_property_set_link() is called and can raise an error to prevent the
1727  * link being set.  If @check is NULL, the property is read-only
1728  * and cannot be set.
1729  *
1730  * Ownership of the pointer that @child points to is transferred to the
1731  * link property.  The reference count for *@child is
1732  * managed by the property from after the function returns till the
1733  * property is deleted with object_property_del().  If the
1734  * @flags %OBJ_PROP_LINK_STRONG bit is set,
1735  * the reference count is decremented when the property is deleted or
1736  * modified.
1737  *
1738  * Returns: The newly added property on success, or %NULL on failure.
1739  */
1740 ObjectProperty *object_property_add_link(Object *obj, const char *name,
1741                               const char *type, Object **targetp,
1742                               void (*check)(const Object *obj, const char *name,
1743                                             Object *val, Error **errp),
1744                               ObjectPropertyLinkFlags flags);
1745 
1746 ObjectProperty *object_class_property_add_link(ObjectClass *oc,
1747                               const char *name,
1748                               const char *type, ptrdiff_t offset,
1749                               void (*check)(const Object *obj, const char *name,
1750                                             Object *val, Error **errp),
1751                               ObjectPropertyLinkFlags flags);
1752 
1753 /**
1754  * object_property_add_str:
1755  * @obj: the object to add a property to
1756  * @name: the name of the property
1757  * @get: the getter or NULL if the property is write-only.  This function must
1758  *   return a string to be freed by g_free().
1759  * @set: the setter or NULL if the property is read-only
1760  *
1761  * Add a string property using getters/setters.  This function will add a
1762  * property of type 'string'.
1763  *
1764  * Returns: The newly added property on success, or %NULL on failure.
1765  */
1766 ObjectProperty *object_property_add_str(Object *obj, const char *name,
1767                              char *(*get)(Object *, Error **),
1768                              void (*set)(Object *, const char *, Error **));
1769 
1770 ObjectProperty *object_class_property_add_str(ObjectClass *klass,
1771                                    const char *name,
1772                                    char *(*get)(Object *, Error **),
1773                                    void (*set)(Object *, const char *,
1774                                                Error **));
1775 
1776 /**
1777  * object_property_add_bool:
1778  * @obj: the object to add a property to
1779  * @name: the name of the property
1780  * @get: the getter or NULL if the property is write-only.
1781  * @set: the setter or NULL if the property is read-only
1782  *
1783  * Add a bool property using getters/setters.  This function will add a
1784  * property of type 'bool'.
1785  *
1786  * Returns: The newly added property on success, or %NULL on failure.
1787  */
1788 ObjectProperty *object_property_add_bool(Object *obj, const char *name,
1789                               bool (*get)(Object *, Error **),
1790                               void (*set)(Object *, bool, Error **));
1791 
1792 ObjectProperty *object_class_property_add_bool(ObjectClass *klass,
1793                                     const char *name,
1794                                     bool (*get)(Object *, Error **),
1795                                     void (*set)(Object *, bool, Error **));
1796 
1797 /**
1798  * object_property_add_enum:
1799  * @obj: the object to add a property to
1800  * @name: the name of the property
1801  * @typename: the name of the enum data type
1802  * @lookup: enum value namelookup table
1803  * @get: the getter or %NULL if the property is write-only.
1804  * @set: the setter or %NULL if the property is read-only
1805  *
1806  * Add an enum property using getters/setters.  This function will add a
1807  * property of type '@typename'.
1808  *
1809  * Returns: The newly added property on success, or %NULL on failure.
1810  */
1811 ObjectProperty *object_property_add_enum(Object *obj, const char *name,
1812                               const char *typename,
1813                               const QEnumLookup *lookup,
1814                               int (*get)(Object *, Error **),
1815                               void (*set)(Object *, int, Error **));
1816 
1817 ObjectProperty *object_class_property_add_enum(ObjectClass *klass,
1818                                     const char *name,
1819                                     const char *typename,
1820                                     const QEnumLookup *lookup,
1821                                     int (*get)(Object *, Error **),
1822                                     void (*set)(Object *, int, Error **));
1823 
1824 /**
1825  * object_property_add_tm:
1826  * @obj: the object to add a property to
1827  * @name: the name of the property
1828  * @get: the getter or NULL if the property is write-only.
1829  *
1830  * Add a read-only struct tm valued property using a getter function.
1831  * This function will add a property of type 'struct tm'.
1832  *
1833  * Returns: The newly added property on success, or %NULL on failure.
1834  */
1835 ObjectProperty *object_property_add_tm(Object *obj, const char *name,
1836                             void (*get)(Object *, struct tm *, Error **));
1837 
1838 ObjectProperty *object_class_property_add_tm(ObjectClass *klass,
1839                             const char *name,
1840                             void (*get)(Object *, struct tm *, Error **));
1841 
1842 typedef enum {
1843     /* Automatically add a getter to the property */
1844     OBJ_PROP_FLAG_READ = 1 << 0,
1845     /* Automatically add a setter to the property */
1846     OBJ_PROP_FLAG_WRITE = 1 << 1,
1847     /* Automatically add a getter and a setter to the property */
1848     OBJ_PROP_FLAG_READWRITE = (OBJ_PROP_FLAG_READ | OBJ_PROP_FLAG_WRITE),
1849 } ObjectPropertyFlags;
1850 
1851 /**
1852  * object_property_add_uint8_ptr:
1853  * @obj: the object to add a property to
1854  * @name: the name of the property
1855  * @v: pointer to value
1856  * @flags: bitwise-or'd ObjectPropertyFlags
1857  *
1858  * Add an integer property in memory.  This function will add a
1859  * property of type 'uint8'.
1860  *
1861  * Returns: The newly added property on success, or %NULL on failure.
1862  */
1863 ObjectProperty *object_property_add_uint8_ptr(Object *obj, const char *name,
1864                                               const uint8_t *v,
1865                                               ObjectPropertyFlags flags);
1866 
1867 ObjectProperty *object_class_property_add_uint8_ptr(ObjectClass *klass,
1868                                          const char *name,
1869                                          const uint8_t *v,
1870                                          ObjectPropertyFlags flags);
1871 
1872 /**
1873  * object_property_add_uint16_ptr:
1874  * @obj: the object to add a property to
1875  * @name: the name of the property
1876  * @v: pointer to value
1877  * @flags: bitwise-or'd ObjectPropertyFlags
1878  *
1879  * Add an integer property in memory.  This function will add a
1880  * property of type 'uint16'.
1881  *
1882  * Returns: The newly added property on success, or %NULL on failure.
1883  */
1884 ObjectProperty *object_property_add_uint16_ptr(Object *obj, const char *name,
1885                                     const uint16_t *v,
1886                                     ObjectPropertyFlags flags);
1887 
1888 ObjectProperty *object_class_property_add_uint16_ptr(ObjectClass *klass,
1889                                           const char *name,
1890                                           const uint16_t *v,
1891                                           ObjectPropertyFlags flags);
1892 
1893 /**
1894  * object_property_add_uint32_ptr:
1895  * @obj: the object to add a property to
1896  * @name: the name of the property
1897  * @v: pointer to value
1898  * @flags: bitwise-or'd ObjectPropertyFlags
1899  *
1900  * Add an integer property in memory.  This function will add a
1901  * property of type 'uint32'.
1902  *
1903  * Returns: The newly added property on success, or %NULL on failure.
1904  */
1905 ObjectProperty *object_property_add_uint32_ptr(Object *obj, const char *name,
1906                                     const uint32_t *v,
1907                                     ObjectPropertyFlags flags);
1908 
1909 ObjectProperty *object_class_property_add_uint32_ptr(ObjectClass *klass,
1910                                           const char *name,
1911                                           const uint32_t *v,
1912                                           ObjectPropertyFlags flags);
1913 
1914 /**
1915  * object_property_add_uint64_ptr:
1916  * @obj: the object to add a property to
1917  * @name: the name of the property
1918  * @v: pointer to value
1919  * @flags: bitwise-or'd ObjectPropertyFlags
1920  *
1921  * Add an integer property in memory.  This function will add a
1922  * property of type 'uint64'.
1923  *
1924  * Returns: The newly added property on success, or %NULL on failure.
1925  */
1926 ObjectProperty *object_property_add_uint64_ptr(Object *obj, const char *name,
1927                                     const uint64_t *v,
1928                                     ObjectPropertyFlags flags);
1929 
1930 ObjectProperty *object_class_property_add_uint64_ptr(ObjectClass *klass,
1931                                           const char *name,
1932                                           const uint64_t *v,
1933                                           ObjectPropertyFlags flags);
1934 
1935 /**
1936  * object_property_add_alias:
1937  * @obj: the object to add a property to
1938  * @name: the name of the property
1939  * @target_obj: the object to forward property access to
1940  * @target_name: the name of the property on the forwarded object
1941  *
1942  * Add an alias for a property on an object.  This function will add a property
1943  * of the same type as the forwarded property.
1944  *
1945  * The caller must ensure that @target_obj stays alive as long as
1946  * this property exists.  In the case of a child object or an alias on the same
1947  * object this will be the case.  For aliases to other objects the caller is
1948  * responsible for taking a reference.
1949  *
1950  * Returns: The newly added property on success, or %NULL on failure.
1951  */
1952 ObjectProperty *object_property_add_alias(Object *obj, const char *name,
1953                                Object *target_obj, const char *target_name);
1954 
1955 /**
1956  * object_property_add_const_link:
1957  * @obj: the object to add a property to
1958  * @name: the name of the property
1959  * @target: the object to be referred by the link
1960  *
1961  * Add an unmodifiable link for a property on an object.  This function will
1962  * add a property of type link<TYPE> where TYPE is the type of @target.
1963  *
1964  * The caller must ensure that @target stays alive as long as
1965  * this property exists.  In the case @target is a child of @obj,
1966  * this will be the case.  Otherwise, the caller is responsible for
1967  * taking a reference.
1968  *
1969  * Returns: The newly added property on success, or %NULL on failure.
1970  */
1971 ObjectProperty *object_property_add_const_link(Object *obj, const char *name,
1972                                                Object *target);
1973 
1974 /**
1975  * object_property_set_description:
1976  * @obj: the object owning the property
1977  * @name: the name of the property
1978  * @description: the description of the property on the object
1979  *
1980  * Set an object property's description.
1981  *
1982  * Returns: %true on success, %false on failure.
1983  */
1984 void object_property_set_description(Object *obj, const char *name,
1985                                      const char *description);
1986 void object_class_property_set_description(ObjectClass *klass, const char *name,
1987                                            const char *description);
1988 
1989 /**
1990  * object_child_foreach:
1991  * @obj: the object whose children will be navigated
1992  * @fn: the iterator function to be called
1993  * @opaque: an opaque value that will be passed to the iterator
1994  *
1995  * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1996  * non-zero.
1997  *
1998  * It is forbidden to add or remove children from @obj from the @fn
1999  * callback.
2000  *
2001  * Returns: The last value returned by @fn, or 0 if there is no child.
2002  */
2003 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
2004                          void *opaque);
2005 
2006 /**
2007  * object_child_foreach_recursive:
2008  * @obj: the object whose children will be navigated
2009  * @fn: the iterator function to be called
2010  * @opaque: an opaque value that will be passed to the iterator
2011  *
2012  * Call @fn passing each child of @obj and @opaque to it, until @fn returns
2013  * non-zero. Calls recursively, all child nodes of @obj will also be passed
2014  * all the way down to the leaf nodes of the tree. Depth first ordering.
2015  *
2016  * It is forbidden to add or remove children from @obj (or its
2017  * child nodes) from the @fn callback.
2018  *
2019  * Returns: The last value returned by @fn, or 0 if there is no child.
2020  */
2021 int object_child_foreach_recursive(Object *obj,
2022                                    int (*fn)(Object *child, void *opaque),
2023                                    void *opaque);
2024 
2025 /**
2026  * object_property_add_new_container:
2027  * @obj: the parent object
2028  * @name: the name of the parent object's property to add
2029  *
2030  * Add a newly created container object to a parent object.
2031  *
2032  * Returns: the newly created container object.  Its reference count is 1,
2033  * and the reference is owned by the parent object.
2034  */
2035 Object *object_property_add_new_container(Object *obj, const char *name);
2036 
2037 /**
2038  * object_property_help:
2039  * @name: the name of the property
2040  * @type: the type of the property
2041  * @defval: the default value
2042  * @description: description of the property
2043  *
2044  * Returns: a user-friendly formatted string describing the property
2045  * for help purposes.
2046  */
2047 char *object_property_help(const char *name, const char *type,
2048                            QObject *defval, const char *description);
2049 
2050 G_DEFINE_AUTOPTR_CLEANUP_FUNC(Object, object_unref)
2051 
2052 #endif
2053