qom/object.c

   1 /*
   2  * QEMU Object Model
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <[email protected]>
   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 #include "qom/object.h"
  14 #include "qemu-common.h"
  15 #include "qapi/visitor.h"
  16 #include "qapi-visit.h"
  17 #include "qapi/string-input-visitor.h"
  18 #include "qapi/string-output-visitor.h"
  19 #include "qapi/qmp/qerror.h"
  20 #include "trace.h"
  21
  22 /* TODO: replace QObject with a simpler visitor to avoid a dependency
  23  * of the QOM core on QObject?  */
  24 #include "qom/qom-qobject.h"
  25 #include "qapi/qmp/qobject.h"
  26 #include "qapi/qmp/qbool.h"
  27 #include "qapi/qmp/qint.h"
  28 #include "qapi/qmp/qstring.h"
  29
  30 #define MAX_INTERFACES 32
  31
  32 typedef struct InterfaceImpl InterfaceImpl;
  33 typedef struct TypeImpl TypeImpl;
  34
  35 struct InterfaceImpl
  36 {
  37     const char *typename;
  38 };
  39
  40 struct TypeImpl
  41 {
  42     const char *name;
  43
  44     size_t class_size;
  45
  46     size_t instance_size;
  47
  48     void (*class_init)(ObjectClass *klass, void *data);
  49     void (*class_base_init)(ObjectClass *klass, void *data);
  50     void (*class_finalize)(ObjectClass *klass, void *data);
  51
  52     void *class_data;
  53
  54     void (*instance_init)(Object *obj);
  55     void (*instance_post_init)(Object *obj);
  56     void (*instance_finalize)(Object *obj);
  57
  58     bool abstract;
  59
  60     const char *parent;
  61     TypeImpl *parent_type;
  62
  63     ObjectClass *class;
  64
  65     int num_interfaces;
  66     InterfaceImpl interfaces[MAX_INTERFACES];
  67 };
  68
  69 static Type type_interface;
  70
  71 static GHashTable *type_table_get(void)
  72 {
  73     static GHashTable *type_table;
  74
  75     if (type_table == NULL) {
  76         type_table = g_hash_table_new(g_str_hash, g_str_equal);
  77     }
  78
  79     return type_table;
  80 }
  81
  82 static bool enumerating_types;
  83
  84 static void type_table_add(TypeImpl *ti)
  85 {
  86     assert(!enumerating_types);
  87     g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
  88 }
  89
  90 static TypeImpl *type_table_lookup(const char *name)
  91 {
  92     return g_hash_table_lookup(type_table_get(), name);
  93 }
  94
  95 static TypeImpl *type_new(const TypeInfo *info)
  96 {
  97     TypeImpl *ti = g_malloc0(sizeof(*ti));
  98     int i;
  99
 100     g_assert(info->name != NULL);
 101
 102     if (type_table_lookup(info->name) != NULL) {
 103         fprintf(stderr, "Registering `%s' which already exists\n", info->name);
 104         abort();
 105     }
 106
 107     ti->name = g_strdup(info->name);
 108     ti->parent = g_strdup(info->parent);
 109
 110     ti->class_size = info->class_size;
 111     ti->instance_size = info->instance_size;
 112
 113     ti->class_init = info->class_init;
 114     ti->class_base_init = info->class_base_init;
 115     ti->class_finalize = info->class_finalize;
 116     ti->class_data = info->class_data;
 117
 118     ti->instance_init = info->instance_init;
 119     ti->instance_post_init = info->instance_post_init;
 120     ti->instance_finalize = info->instance_finalize;
 121
 122     ti->abstract = info->abstract;
 123
 124     for (i = 0; info->interfaces && info->interfaces[i].type; i++) {
 125         ti->interfaces[i].typename = g_strdup(info->interfaces[i].type);
 126     }
 127     ti->num_interfaces = i;
 128
 129     return ti;
 130 }
 131
 132 static TypeImpl *type_register_internal(const TypeInfo *info)
 133 {
 134     TypeImpl *ti;
 135     ti = type_new(info);
 136
 137     type_table_add(ti);
 138     return ti;
 139 }
 140
 141 TypeImpl *type_register(const TypeInfo *info)
 142 {
 143     assert(info->parent);
 144     return type_register_internal(info);
 145 }
 146
 147 TypeImpl *type_register_static(const TypeInfo *info)
 148 {
 149     return type_register(info);
 150 }
 151
 152 static TypeImpl *type_get_by_name(const char *name)
 153 {
 154     if (name == NULL) {
 155         return NULL;
 156     }
 157
 158     return type_table_lookup(name);
 159 }
 160
 161 static TypeImpl *type_get_parent(TypeImpl *type)
 162 {
 163     if (!type->parent_type && type->parent) {
 164         type->parent_type = type_get_by_name(type->parent);
 165         g_assert(type->parent_type != NULL);
 166     }
 167
 168     return type->parent_type;
 169 }
 170
 171 static bool type_has_parent(TypeImpl *type)
 172 {
 173     return (type->parent != NULL);
 174 }
 175
 176 static size_t type_class_get_size(TypeImpl *ti)
 177 {
 178     if (ti->class_size) {
 179         return ti->class_size;
 180     }
 181
 182     if (type_has_parent(ti)) {
 183         return type_class_get_size(type_get_parent(ti));
 184     }
 185
 186     return sizeof(ObjectClass);
 187 }
 188
 189 static size_t type_object_get_size(TypeImpl *ti)
 190 {
 191     if (ti->instance_size) {
 192         return ti->instance_size;
 193     }
 194
 195     if (type_has_parent(ti)) {
 196         return type_object_get_size(type_get_parent(ti));
 197     }
 198
 199     return 0;
 200 }
 201
 202 static bool type_is_ancestor(TypeImpl *type, TypeImpl *target_type)
 203 {
 204     assert(target_type);
 205
 206     /* Check if typename is a direct ancestor of type */
 207     while (type) {
 208         if (type == target_type) {
 209             return true;
 210         }
 211
 212         type = type_get_parent(type);
 213     }
 214
 215     return false;
 216 }
 217
 218 static void type_initialize(TypeImpl *ti);
 219
 220 static void type_initialize_interface(TypeImpl *ti, TypeImpl *interface_type,
 221                                       TypeImpl *parent_type)
 222 {
 223     InterfaceClass *new_iface;
 224     TypeInfo info = { };
 225     TypeImpl *iface_impl;
 226
 227     info.parent = parent_type->name;
 228     info.name = g_strdup_printf("%s::%s", ti->name, interface_type->name);
 229     info.abstract = true;
 230
 231     iface_impl = type_new(&info);
 232     iface_impl->parent_type = parent_type;
 233     type_initialize(iface_impl);
 234     g_free((char *)info.name);
 235
 236     new_iface = (InterfaceClass *)iface_impl->class;
 237     new_iface->concrete_class = ti->class;
 238     new_iface->interface_type = interface_type;
 239
 240     ti->class->interfaces = g_slist_append(ti->class->interfaces,
 241                                            iface_impl->class);
 242 }
 243
 244 static void type_initialize(TypeImpl *ti)
 245 {
 246     TypeImpl *parent;
 247
 248     if (ti->class) {
 249         return;
 250     }
 251
 252     ti->class_size = type_class_get_size(ti);
 253     ti->instance_size = type_object_get_size(ti);
 254
 255     ti->class = g_malloc0(ti->class_size);
 256
 257     parent = type_get_parent(ti);
 258     if (parent) {
 259         type_initialize(parent);
 260         GSList *e;
 261         int i;
 262
 263         g_assert(parent->class_size <= ti->class_size);
 264         memcpy(ti->class, parent->class, parent->class_size);
 265         ti->class->interfaces = NULL;
 266
 267         for (e = parent->class->interfaces; e; e = e->next) {
 268             InterfaceClass *iface = e->data;
 269             ObjectClass *klass = OBJECT_CLASS(iface);
 270
 271             type_initialize_interface(ti, iface->interface_type, klass->type);
 272         }
 273
 274         for (i = 0; i < ti->num_interfaces; i++) {
 275             TypeImpl *t = type_get_by_name(ti->interfaces[i].typename);
 276             for (e = ti->class->interfaces; e; e = e->next) {
 277                 TypeImpl *target_type = OBJECT_CLASS(e->data)->type;
 278
 279                 if (type_is_ancestor(target_type, t)) {
 280                     break;
 281                 }
 282             }
 283
 284             if (e) {
 285                 continue;
 286             }
 287
 288             type_initialize_interface(ti, t, t);
 289         }
 290     }
 291
 292     ti->class->type = ti;
 293
 294     while (parent) {
 295         if (parent->class_base_init) {
 296             parent->class_base_init(ti->class, ti->class_data);
 297         }
 298         parent = type_get_parent(parent);
 299     }
 300
 301     if (ti->class_init) {
 302         ti->class_init(ti->class, ti->class_data);
 303     }
 304 }
 305
 306 static void object_init_with_type(Object *obj, TypeImpl *ti)
 307 {
 308     if (type_has_parent(ti)) {
 309         object_init_with_type(obj, type_get_parent(ti));
 310     }
 311
 312     if (ti->instance_init) {
 313         ti->instance_init(obj);
 314     }
 315 }
 316
 317 static void object_post_init_with_type(Object *obj, TypeImpl *ti)
 318 {
 319     if (ti->instance_post_init) {
 320         ti->instance_post_init(obj);
 321     }
 322
 323     if (type_has_parent(ti)) {
 324         object_post_init_with_type(obj, type_get_parent(ti));
 325     }
 326 }
 327
 328 void object_initialize_with_type(void *data, size_t size, TypeImpl *type)
 329 {
 330     Object *obj = data;
 331
 332     g_assert(type != NULL);
 333     type_initialize(type);
 334
 335     g_assert(type->instance_size >= sizeof(Object));
 336     g_assert(type->abstract == false);
 337     g_assert(size >= type->instance_size);
 338
 339     memset(obj, 0, type->instance_size);
 340     obj->class = type->class;
 341     object_ref(obj);
 342     QTAILQ_INIT(&obj->properties);
 343     object_init_with_type(obj, type);
 344     object_post_init_with_type(obj, type);
 345 }
 346
 347 void object_initialize(void *data, size_t size, const char *typename)
 348 {
 349     TypeImpl *type = type_get_by_name(typename);
 350
 351     object_initialize_with_type(data, size, type);
 352 }
 353
 354 static inline bool object_property_is_child(ObjectProperty *prop)
 355 {
 356     return strstart(prop->type, "child<", NULL);
 357 }
 358
 359 static void object_property_del_all(Object *obj)
 360 {
 361     while (!QTAILQ_EMPTY(&obj->properties)) {
 362         ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
 363
 364         QTAILQ_REMOVE(&obj->properties, prop, node);
 365
 366         if (prop->release) {
 367             prop->release(obj, prop->name, prop->opaque);
 368         }
 369
 370         g_free(prop->name);
 371         g_free(prop->type);
 372         g_free(prop->description);
 373         g_free(prop);
 374     }
 375 }
 376
 377 static void object_property_del_child(Object *obj, Object *child, Error **errp)
 378 {
 379     ObjectProperty *prop;
 380
 381     QTAILQ_FOREACH(prop, &obj->properties, node) {
 382         if (object_property_is_child(prop) && prop->opaque == child) {
 383             object_property_del(obj, prop->name, errp);
 384             break;
 385         }
 386     }
 387 }
 388
 389 void object_unparent(Object *obj)
 390 {
 391     if (obj->parent) {
 392         object_property_del_child(obj->parent, obj, NULL);
 393     }
 394 }
 395
 396 static void object_deinit(Object *obj, TypeImpl *type)
 397 {
 398     if (type->instance_finalize) {
 399         type->instance_finalize(obj);
 400     }
 401
 402     if (type_has_parent(type)) {
 403         object_deinit(obj, type_get_parent(type));
 404     }
 405 }
 406
 407 static void object_finalize(void *data)
 408 {
 409     Object *obj = data;
 410     TypeImpl *ti = obj->class->type;
 411
 412     object_property_del_all(obj);
 413     object_deinit(obj, ti);
 414
 415     g_assert(obj->ref == 0);
 416     if (obj->free) {
 417         obj->free(obj);
 418     }
 419 }
 420
 421 Object *object_new_with_type(Type type)
 422 {
 423     Object *obj;
 424
 425     g_assert(type != NULL);
 426     type_initialize(type);
 427
 428     obj = g_malloc(type->instance_size);
 429     object_initialize_with_type(obj, type->instance_size, type);
 430     obj->free = g_free;
 431
 432     return obj;
 433 }
 434
 435 Object *object_new(const char *typename)
 436 {
 437     TypeImpl *ti = type_get_by_name(typename);
 438
 439     return object_new_with_type(ti);
 440 }
 441
 442 Object *object_dynamic_cast(Object *obj, const char *typename)
 443 {
 444     if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) {
 445         return obj;
 446     }
 447
 448     return NULL;
 449 }
 450
 451 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
 452                                    const char *file, int line, const char *func)
 453 {
 454     trace_object_dynamic_cast_assert(obj ? obj->class->type->name : "(null)",
 455                                      typename, file, line, func);
 456
 457 #ifdef CONFIG_QOM_CAST_DEBUG
 458     int i;
 459     Object *inst;
 460
 461     for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
 462         if (obj->class->object_cast_cache[i] == typename) {
 463             goto out;
 464         }
 465     }
 466
 467     inst = object_dynamic_cast(obj, typename);
 468
 469     if (!inst && obj) {
 470         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 471                 file, line, func, obj, typename);
 472         abort();
 473     }
 474
 475     assert(obj == inst);
 476
 477     if (obj && obj == inst) {
 478         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 479             obj->class->object_cast_cache[i - 1] =
 480                     obj->class->object_cast_cache[i];
 481         }
 482         obj->class->object_cast_cache[i - 1] = typename;
 483     }
 484
 485 out:
 486 #endif
 487     return obj;
 488 }
 489
 490 ObjectClass *object_class_dynamic_cast(ObjectClass *class,
 491                                        const char *typename)
 492 {
 493     ObjectClass *ret = NULL;
 494     TypeImpl *target_type;
 495     TypeImpl *type;
 496
 497     if (!class) {
 498         return NULL;
 499     }
 500
 501     /* A simple fast path that can trigger a lot for leaf classes.  */
 502     type = class->type;
 503     if (type->name == typename) {
 504         return class;
 505     }
 506
 507     target_type = type_get_by_name(typename);
 508     if (!target_type) {
 509         /* target class type unknown, so fail the cast */
 510         return NULL;
 511     }
 512
 513     if (type->class->interfaces &&
 514             type_is_ancestor(target_type, type_interface)) {
 515         int found = 0;
 516         GSList *i;
 517
 518         for (i = class->interfaces; i; i = i->next) {
 519             ObjectClass *target_class = i->data;
 520
 521             if (type_is_ancestor(target_class->type, target_type)) {
 522                 ret = target_class;
 523                 found++;
 524             }
 525          }
 526
 527         /* The match was ambiguous, don't allow a cast */
 528         if (found > 1) {
 529             ret = NULL;
 530         }
 531     } else if (type_is_ancestor(type, target_type)) {
 532         ret = class;
 533     }
 534
 535     return ret;
 536 }
 537
 538 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
 539                                               const char *typename,
 540                                               const char *file, int line,
 541                                               const char *func)
 542 {
 543     ObjectClass *ret;
 544
 545     trace_object_class_dynamic_cast_assert(class ? class->type->name : "(null)",
 546                                            typename, file, line, func);
 547
 548 #ifdef CONFIG_QOM_CAST_DEBUG
 549     int i;
 550
 551     for (i = 0; class && i < OBJECT_CLASS_CAST_CACHE; i++) {
 552         if (class->class_cast_cache[i] == typename) {
 553             ret = class;
 554             goto out;
 555         }
 556     }
 557 #else
 558     if (!class || !class->interfaces) {
 559         return class;
 560     }
 561 #endif
 562
 563     ret = object_class_dynamic_cast(class, typename);
 564     if (!ret && class) {
 565         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 566                 file, line, func, class, typename);
 567         abort();
 568     }
 569
 570 #ifdef CONFIG_QOM_CAST_DEBUG
 571     if (class && ret == class) {
 572         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 573             class->class_cast_cache[i - 1] = class->class_cast_cache[i];
 574         }
 575         class->class_cast_cache[i - 1] = typename;
 576     }
 577 out:
 578 #endif
 579     return ret;
 580 }
 581
 582 const char *object_get_typename(Object *obj)
 583 {
 584     return obj->class->type->name;
 585 }
 586
 587 ObjectClass *object_get_class(Object *obj)
 588 {
 589     return obj->class;
 590 }
 591
 592 bool object_class_is_abstract(ObjectClass *klass)
 593 {
 594     return klass->type->abstract;
 595 }
 596
 597 const char *object_class_get_name(ObjectClass *klass)
 598 {
 599     return klass->type->name;
 600 }
 601
 602 ObjectClass *object_class_by_name(const char *typename)
 603 {
 604     TypeImpl *type = type_get_by_name(typename);
 605
 606     if (!type) {
 607         return NULL;
 608     }
 609
 610     type_initialize(type);
 611
 612     return type->class;
 613 }
 614
 615 ObjectClass *object_class_get_parent(ObjectClass *class)
 616 {
 617     TypeImpl *type = type_get_parent(class->type);
 618
 619     if (!type) {
 620         return NULL;
 621     }
 622
 623     type_initialize(type);
 624
 625     return type->class;
 626 }
 627
 628 typedef struct OCFData
 629 {
 630     void (*fn)(ObjectClass *klass, void *opaque);
 631     const char *implements_type;
 632     bool include_abstract;
 633     void *opaque;
 634 } OCFData;
 635
 636 static void object_class_foreach_tramp(gpointer key, gpointer value,
 637                                        gpointer opaque)
 638 {
 639     OCFData *data = opaque;
 640     TypeImpl *type = value;
 641     ObjectClass *k;
 642
 643     type_initialize(type);
 644     k = type->class;
 645
 646     if (!data->include_abstract && type->abstract) {
 647         return;
 648     }
 649
 650     if (data->implements_type &&
 651         !object_class_dynamic_cast(k, data->implements_type)) {
 652         return;
 653     }
 654
 655     data->fn(k, data->opaque);
 656 }
 657
 658 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 659                           const char *implements_type, bool include_abstract,
 660                           void *opaque)
 661 {
 662     OCFData data = { fn, implements_type, include_abstract, opaque };
 663
 664     enumerating_types = true;
 665     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 666     enumerating_types = false;
 667 }
 668
 669 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
 670                          void *opaque)
 671 {
 672     ObjectProperty *prop, *next;
 673     int ret = 0;
 674
 675     QTAILQ_FOREACH_SAFE(prop, &obj->properties, node, next) {
 676         if (object_property_is_child(prop)) {
 677             ret = fn(prop->opaque, opaque);
 678             if (ret != 0) {
 679                 break;
 680             }
 681         }
 682     }
 683     return ret;
 684 }
 685
 686 static void object_class_get_list_tramp(ObjectClass *klass, void *opaque)
 687 {
 688     GSList **list = opaque;
 689
 690     *list = g_slist_prepend(*list, klass);
 691 }
 692
 693 GSList *object_class_get_list(const char *implements_type,
 694                               bool include_abstract)
 695 {
 696     GSList *list = NULL;
 697
 698     object_class_foreach(object_class_get_list_tramp,
 699                          implements_type, include_abstract, &list);
 700     return list;
 701 }
 702
 703 void object_ref(Object *obj)
 704 {
 705     if (!obj) {
 706         return;
 707     }
 708      atomic_inc(&obj->ref);
 709 }
 710
 711 void object_unref(Object *obj)
 712 {
 713     if (!obj) {
 714         return;
 715     }
 716     g_assert(obj->ref > 0);
 717
 718     /* parent always holds a reference to its children */
 719     if (atomic_fetch_dec(&obj->ref) == 1) {
 720         object_finalize(obj);
 721     }
 722 }
 723
 724 ObjectProperty *
 725 object_property_add(Object *obj, const char *name, const char *type,
 726                     ObjectPropertyAccessor *get,
 727                     ObjectPropertyAccessor *set,
 728                     ObjectPropertyRelease *release,
 729                     void *opaque, Error **errp)
 730 {
 731     ObjectProperty *prop;
 732     size_t name_len = strlen(name);
 733
 734     if (name_len >= 3 && !memcmp(name + name_len - 3, "[*]", 4)) {
 735         int i;
 736         ObjectProperty *ret;
 737         char *name_no_array = g_strdup(name);
 738
 739         name_no_array[name_len - 3] = '\0';
 740         for (i = 0; ; ++i) {
 741             char *full_name = g_strdup_printf("%s[%d]", name_no_array, i);
 742
 743             ret = object_property_add(obj, full_name, type, get, set,
 744                                       release, opaque, NULL);
 745             g_free(full_name);
 746             if (ret) {
 747                 break;
 748             }
 749         }
 750         g_free(name_no_array);
 751         return ret;
 752     }
 753
 754     QTAILQ_FOREACH(prop, &obj->properties, node) {
 755         if (strcmp(prop->name, name) == 0) {
 756             error_setg(errp, "attempt to add duplicate property '%s'"
 757                        " to object (type '%s')", name,
 758                        object_get_typename(obj));
 759             return NULL;
 760         }
 761     }
 762
 763     prop = g_malloc0(sizeof(*prop));
 764
 765     prop->name = g_strdup(name);
 766     prop->type = g_strdup(type);
 767
 768     prop->get = get;
 769     prop->set = set;
 770     prop->release = release;
 771     prop->opaque = opaque;
 772
 773     QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
 774     return prop;
 775 }
 776
 777 ObjectProperty *object_property_find(Object *obj, const char *name,
 778                                      Error **errp)
 779 {
 780     ObjectProperty *prop;
 781
 782     QTAILQ_FOREACH(prop, &obj->properties, node) {
 783         if (strcmp(prop->name, name) == 0) {
 784             return prop;
 785         }
 786     }
 787
 788     error_setg(errp, "Property '.%s' not found", name);
 789     return NULL;
 790 }
 791
 792 void object_property_del(Object *obj, const char *name, Error **errp)
 793 {
 794     ObjectProperty *prop = object_property_find(obj, name, errp);
 795     if (prop == NULL) {
 796         return;
 797     }
 798
 799     if (prop->release) {
 800         prop->release(obj, name, prop->opaque);
 801     }
 802
 803     QTAILQ_REMOVE(&obj->properties, prop, node);
 804
 805     g_free(prop->name);
 806     g_free(prop->type);
 807     g_free(prop->description);
 808     g_free(prop);
 809 }
 810
 811 void object_property_get(Object *obj, Visitor *v, const char *name,
 812                          Error **errp)
 813 {
 814     ObjectProperty *prop = object_property_find(obj, name, errp);
 815     if (prop == NULL) {
 816         return;
 817     }
 818
 819     if (!prop->get) {
 820         error_set(errp, QERR_PERMISSION_DENIED);
 821     } else {
 822         prop->get(obj, v, prop->opaque, name, errp);
 823     }
 824 }
 825
 826 void object_property_set(Object *obj, Visitor *v, const char *name,
 827                          Error **errp)
 828 {
 829     ObjectProperty *prop = object_property_find(obj, name, errp);
 830     if (prop == NULL) {
 831         return;
 832     }
 833
 834     if (!prop->set) {
 835         error_set(errp, QERR_PERMISSION_DENIED);
 836     } else {
 837         prop->set(obj, v, prop->opaque, name, errp);
 838     }
 839 }
 840
 841 void object_property_set_str(Object *obj, const char *value,
 842                              const char *name, Error **errp)
 843 {
 844     QString *qstr = qstring_from_str(value);
 845     object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
 846
 847     QDECREF(qstr);
 848 }
 849
 850 char *object_property_get_str(Object *obj, const char *name,
 851                               Error **errp)
 852 {
 853     QObject *ret = object_property_get_qobject(obj, name, errp);
 854     QString *qstring;
 855     char *retval;
 856
 857     if (!ret) {
 858         return NULL;
 859     }
 860     qstring = qobject_to_qstring(ret);
 861     if (!qstring) {
 862         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
 863         retval = NULL;
 864     } else {
 865         retval = g_strdup(qstring_get_str(qstring));
 866     }
 867
 868     QDECREF(qstring);
 869     return retval;
 870 }
 871
 872 void object_property_set_link(Object *obj, Object *value,
 873                               const char *name, Error **errp)
 874 {
 875     gchar *path = object_get_canonical_path(value);
 876     object_property_set_str(obj, path, name, errp);
 877     g_free(path);
 878 }
 879
 880 Object *object_property_get_link(Object *obj, const char *name,
 881                                  Error **errp)
 882 {
 883     char *str = object_property_get_str(obj, name, errp);
 884     Object *target = NULL;
 885
 886     if (str && *str) {
 887         target = object_resolve_path(str, NULL);
 888         if (!target) {
 889             error_set(errp, QERR_DEVICE_NOT_FOUND, str);
 890         }
 891     }
 892
 893     g_free(str);
 894     return target;
 895 }
 896
 897 void object_property_set_bool(Object *obj, bool value,
 898                               const char *name, Error **errp)
 899 {
 900     QBool *qbool = qbool_from_int(value);
 901     object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
 902
 903     QDECREF(qbool);
 904 }
 905
 906 bool object_property_get_bool(Object *obj, const char *name,
 907                               Error **errp)
 908 {
 909     QObject *ret = object_property_get_qobject(obj, name, errp);
 910     QBool *qbool;
 911     bool retval;
 912
 913     if (!ret) {
 914         return false;
 915     }
 916     qbool = qobject_to_qbool(ret);
 917     if (!qbool) {
 918         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
 919         retval = false;
 920     } else {
 921         retval = qbool_get_int(qbool);
 922     }
 923
 924     QDECREF(qbool);
 925     return retval;
 926 }
 927
 928 void object_property_set_int(Object *obj, int64_t value,
 929                              const char *name, Error **errp)
 930 {
 931     QInt *qint = qint_from_int(value);
 932     object_property_set_qobject(obj, QOBJECT(qint), name, errp);
 933
 934     QDECREF(qint);
 935 }
 936
 937 int64_t object_property_get_int(Object *obj, const char *name,
 938                                 Error **errp)
 939 {
 940     QObject *ret = object_property_get_qobject(obj, name, errp);
 941     QInt *qint;
 942     int64_t retval;
 943
 944     if (!ret) {
 945         return -1;
 946     }
 947     qint = qobject_to_qint(ret);
 948     if (!qint) {
 949         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
 950         retval = -1;
 951     } else {
 952         retval = qint_get_int(qint);
 953     }
 954
 955     QDECREF(qint);
 956     return retval;
 957 }
 958
 959 int object_property_get_enum(Object *obj, const char *name,
 960                              const char *strings[], Error **errp)
 961 {
 962     StringOutputVisitor *sov;
 963     StringInputVisitor *siv;
 964     char *str;
 965     int ret;
 966
 967     sov = string_output_visitor_new(false);
 968     object_property_get(obj, string_output_get_visitor(sov), name, errp);
 969     str = string_output_get_string(sov);
 970     siv = string_input_visitor_new(str);
 971     string_output_visitor_cleanup(sov);
 972     visit_type_enum(string_input_get_visitor(siv),
 973                     &ret, strings, NULL, name, errp);
 974
 975     g_free(str);
 976     string_input_visitor_cleanup(siv);
 977
 978     return ret;
 979 }
 980
 981 void object_property_get_uint16List(Object *obj, const char *name,
 982                                     uint16List **list, Error **errp)
 983 {
 984     StringOutputVisitor *ov;
 985     StringInputVisitor *iv;
 986     char *str;
 987
 988     ov = string_output_visitor_new(false);
 989     object_property_get(obj, string_output_get_visitor(ov),
 990                         name, errp);
 991     str = string_output_get_string(ov);
 992     iv = string_input_visitor_new(str);
 993     visit_type_uint16List(string_input_get_visitor(iv),
 994                           list, NULL, errp);
 995
 996     g_free(str);
 997     string_output_visitor_cleanup(ov);
 998     string_input_visitor_cleanup(iv);
 999 }
1000
1001 void object_property_parse(Object *obj, const char *string,
1002                            const char *name, Error **errp)
1003 {
1004     StringInputVisitor *mi;
1005     mi = string_input_visitor_new(string);
1006     object_property_set(obj, string_input_get_visitor(mi), name, errp);
1007
1008     string_input_visitor_cleanup(mi);
1009 }
1010
1011 char *object_property_print(Object *obj, const char *name, bool human,
1012                             Error **errp)
1013 {
1014     StringOutputVisitor *mo;
1015     char *string = NULL;
1016     Error *local_err = NULL;
1017
1018     mo = string_output_visitor_new(human);
1019     object_property_get(obj, string_output_get_visitor(mo), name, &local_err);
1020     if (local_err) {
1021         error_propagate(errp, local_err);
1022         goto out;
1023     }
1024
1025     string = string_output_get_string(mo);
1026
1027 out:
1028     string_output_visitor_cleanup(mo);
1029     return string;
1030 }
1031
1032 const char *object_property_get_type(Object *obj, const char *name, Error **errp)
1033 {
1034     ObjectProperty *prop = object_property_find(obj, name, errp);
1035     if (prop == NULL) {
1036         return NULL;
1037     }
1038
1039     return prop->type;
1040 }
1041
1042 Object *object_get_root(void)
1043 {
1044     static Object *root;
1045
1046     if (!root) {
1047         root = object_new("container");
1048     }
1049
1050     return root;
1051 }
1052
1053 static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
1054                                       const char *name, Error **errp)
1055 {
1056     Object *child = opaque;
1057     gchar *path;
1058
1059     path = object_get_canonical_path(child);
1060     visit_type_str(v, &path, name, errp);
1061     g_free(path);
1062 }
1063
1064 static Object *object_resolve_child_property(Object *parent, void *opaque, const gchar *part)
1065 {
1066     return opaque;
1067 }
1068
1069 static void object_finalize_child_property(Object *obj, const char *name,
1070                                            void *opaque)
1071 {
1072     Object *child = opaque;
1073
1074     if (child->class->unparent) {
1075         (child->class->unparent)(child);
1076     }
1077     child->parent = NULL;
1078     object_unref(child);
1079 }
1080
1081 void object_property_add_child(Object *obj, const char *name,
1082                                Object *child, Error **errp)
1083 {
1084     Error *local_err = NULL;
1085     gchar *type;
1086     ObjectProperty *op;
1087
1088     type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
1089
1090     op = object_property_add(obj, name, type, object_get_child_property, NULL,
1091                              object_finalize_child_property, child, &local_err);
1092     if (local_err) {
1093         error_propagate(errp, local_err);
1094         goto out;
1095     }
1096
1097     op->resolve = object_resolve_child_property;
1098     object_ref(child);
1099     g_assert(child->parent == NULL);
1100     child->parent = obj;
1101
1102 out:
1103     g_free(type);
1104 }
1105
1106 void object_property_allow_set_link(Object *obj, const char *name,
1107                                     Object *val, Error **errp)
1108 {
1109     /* Allow the link to be set, always */
1110 }
1111
1112 typedef struct {
1113     Object **child;
1114     void (*check)(Object *, const char *, Object *, Error **);
1115     ObjectPropertyLinkFlags flags;
1116 } LinkProperty;
1117
1118 static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
1119                                      const char *name, Error **errp)
1120 {
1121     LinkProperty *lprop = opaque;
1122     Object **child = lprop->child;
1123     gchar *path;
1124
1125     if (*child) {
1126         path = object_get_canonical_path(*child);
1127         visit_type_str(v, &path, name, errp);
1128         g_free(path);
1129     } else {
1130         path = (gchar *)"";
1131         visit_type_str(v, &path, name, errp);
1132     }
1133 }
1134
1135 /*
1136  * object_resolve_link:
1137  *
1138  * Lookup an object and ensure its type matches the link property type.  This
1139  * is similar to object_resolve_path() except type verification against the
1140  * link property is performed.
1141  *
1142  * Returns: The matched object or NULL on path lookup failures.
1143  */
1144 static Object *object_resolve_link(Object *obj, const char *name,
1145                                    const char *path, Error **errp)
1146 {
1147     const char *type;
1148     gchar *target_type;
1149     bool ambiguous = false;
1150     Object *target;
1151
1152     /* Go from link<FOO> to FOO.  */
1153     type = object_property_get_type(obj, name, NULL);
1154     target_type = g_strndup(&type[5], strlen(type) - 6);
1155     target = object_resolve_path_type(path, target_type, &ambiguous);
1156
1157     if (ambiguous) {
1158         error_set(errp, ERROR_CLASS_GENERIC_ERROR,
1159                   "Path '%s' does not uniquely identify an object", path);
1160     } else if (!target) {
1161         target = object_resolve_path(path, &ambiguous);
1162         if (target || ambiguous) {
1163             error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
1164         } else {
1165             error_set(errp, QERR_DEVICE_NOT_FOUND, path);
1166         }
1167         target = NULL;
1168     }
1169     g_free(target_type);
1170
1171     return target;
1172 }
1173
1174 static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
1175                                      const char *name, Error **errp)
1176 {
1177     Error *local_err = NULL;
1178     LinkProperty *prop = opaque;
1179     Object **child = prop->child;
1180     Object *old_target = *child;
1181     Object *new_target = NULL;
1182     char *path = NULL;
1183
1184     visit_type_str(v, &path, name, &local_err);
1185
1186     if (!local_err && strcmp(path, "") != 0) {
1187         new_target = object_resolve_link(obj, name, path, &local_err);
1188     }
1189
1190     g_free(path);
1191     if (local_err) {
1192         error_propagate(errp, local_err);
1193         return;
1194     }
1195
1196     prop->check(obj, name, new_target, &local_err);
1197     if (local_err) {
1198         error_propagate(errp, local_err);
1199         return;
1200     }
1201
1202     object_ref(new_target);
1203     *child = new_target;
1204     object_unref(old_target);
1205 }
1206
1207 static Object *object_resolve_link_property(Object *parent, void *opaque, const gchar *part)
1208 {
1209     LinkProperty *lprop = opaque;
1210
1211     return *lprop->child;
1212 }
1213
1214 static void object_release_link_property(Object *obj, const char *name,
1215                                          void *opaque)
1216 {
1217     LinkProperty *prop = opaque;
1218
1219     if ((prop->flags & OBJ_PROP_LINK_UNREF_ON_RELEASE) && *prop->child) {
1220         object_unref(*prop->child);
1221     }
1222     g_free(prop);
1223 }
1224
1225 void object_property_add_link(Object *obj, const char *name,
1226                               const char *type, Object **child,
1227                               void (*check)(Object *, const char *,
1228                                             Object *, Error **),
1229                               ObjectPropertyLinkFlags flags,
1230                               Error **errp)
1231 {
1232     Error *local_err = NULL;
1233     LinkProperty *prop = g_malloc(sizeof(*prop));
1234     gchar *full_type;
1235     ObjectProperty *op;
1236
1237     prop->child = child;
1238     prop->check = check;
1239     prop->flags = flags;
1240
1241     full_type = g_strdup_printf("link<%s>", type);
1242
1243     op = object_property_add(obj, name, full_type,
1244                              object_get_link_property,
1245                              check ? object_set_link_property : NULL,
1246                              object_release_link_property,
1247                              prop,
1248                              &local_err);
1249     if (local_err) {
1250         error_propagate(errp, local_err);
1251         g_free(prop);
1252         goto out;
1253     }
1254
1255     op->resolve = object_resolve_link_property;
1256
1257 out:
1258     g_free(full_type);
1259 }
1260
1261 gchar *object_get_canonical_path_component(Object *obj)
1262 {
1263     ObjectProperty *prop = NULL;
1264
1265     g_assert(obj);
1266     g_assert(obj->parent != NULL);
1267
1268     QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
1269         if (!object_property_is_child(prop)) {
1270             continue;
1271         }
1272
1273         if (prop->opaque == obj) {
1274             return g_strdup(prop->name);
1275         }
1276     }
1277
1278     /* obj had a parent but was not a child, should never happen */
1279     g_assert_not_reached();
1280     return NULL;
1281 }
1282
1283 gchar *object_get_canonical_path(Object *obj)
1284 {
1285     Object *root = object_get_root();
1286     char *newpath, *path = NULL;
1287
1288     while (obj != root) {
1289         char *component = object_get_canonical_path_component(obj);
1290
1291         if (path) {
1292             newpath = g_strdup_printf("%s/%s", component, path);
1293             g_free(component);
1294             g_free(path);
1295             path = newpath;
1296         } else {
1297             path = component;
1298         }
1299
1300         obj = obj->parent;
1301     }
1302
1303     newpath = g_strdup_printf("/%s", path ? path : "");
1304     g_free(path);
1305
1306     return newpath;
1307 }
1308
1309 Object *object_resolve_path_component(Object *parent, const gchar *part)
1310 {
1311     ObjectProperty *prop = object_property_find(parent, part, NULL);
1312     if (prop == NULL) {
1313         return NULL;
1314     }
1315
1316     if (prop->resolve) {
1317         return prop->resolve(parent, prop->opaque, part);
1318     } else {
1319         return NULL;
1320     }
1321 }
1322
1323 static Object *object_resolve_abs_path(Object *parent,
1324                                           gchar **parts,
1325                                           const char *typename,
1326                                           int index)
1327 {
1328     Object *child;
1329
1330     if (parts[index] == NULL) {
1331         return object_dynamic_cast(parent, typename);
1332     }
1333
1334     if (strcmp(parts[index], "") == 0) {
1335         return object_resolve_abs_path(parent, parts, typename, index + 1);
1336     }
1337
1338     child = object_resolve_path_component(parent, parts[index]);
1339     if (!child) {
1340         return NULL;
1341     }
1342
1343     return object_resolve_abs_path(child, parts, typename, index + 1);
1344 }
1345
1346 static Object *object_resolve_partial_path(Object *parent,
1347                                               gchar **parts,
1348                                               const char *typename,
1349                                               bool *ambiguous)
1350 {
1351     Object *obj;
1352     ObjectProperty *prop;
1353
1354     obj = object_resolve_abs_path(parent, parts, typename, 0);
1355
1356     QTAILQ_FOREACH(prop, &parent->properties, node) {
1357         Object *found;
1358
1359         if (!object_property_is_child(prop)) {
1360             continue;
1361         }
1362
1363         found = object_resolve_partial_path(prop->opaque, parts,
1364                                             typename, ambiguous);
1365         if (found) {
1366             if (obj) {
1367                 if (ambiguous) {
1368                     *ambiguous = true;
1369                 }
1370                 return NULL;
1371             }
1372             obj = found;
1373         }
1374
1375         if (ambiguous && *ambiguous) {
1376             return NULL;
1377         }
1378     }
1379
1380     return obj;
1381 }
1382
1383 Object *object_resolve_path_type(const char *path, const char *typename,
1384                                  bool *ambiguous)
1385 {
1386     Object *obj;
1387     gchar **parts;
1388
1389     parts = g_strsplit(path, "/", 0);
1390     assert(parts);
1391
1392     if (parts[0] == NULL || strcmp(parts[0], "") != 0) {
1393         if (ambiguous) {
1394             *ambiguous = false;
1395         }
1396         obj = object_resolve_partial_path(object_get_root(), parts,
1397                                           typename, ambiguous);
1398     } else {
1399         obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
1400     }
1401
1402     g_strfreev(parts);
1403
1404     return obj;
1405 }
1406
1407 Object *object_resolve_path(const char *path, bool *ambiguous)
1408 {
1409     return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
1410 }
1411
1412 typedef struct StringProperty
1413 {
1414     char *(*get)(Object *, Error **);
1415     void (*set)(Object *, const char *, Error **);
1416 } StringProperty;
1417
1418 static void property_get_str(Object *obj, Visitor *v, void *opaque,
1419                              const char *name, Error **errp)
1420 {
1421     StringProperty *prop = opaque;
1422     char *value;
1423
1424     value = prop->get(obj, errp);
1425     if (value) {
1426         visit_type_str(v, &value, name, errp);
1427         g_free(value);
1428     }
1429 }
1430
1431 static void property_set_str(Object *obj, Visitor *v, void *opaque,
1432                              const char *name, Error **errp)
1433 {
1434     StringProperty *prop = opaque;
1435     char *value;
1436     Error *local_err = NULL;
1437
1438     visit_type_str(v, &value, name, &local_err);
1439     if (local_err) {
1440         error_propagate(errp, local_err);
1441         return;
1442     }
1443
1444     prop->set(obj, value, errp);
1445     g_free(value);
1446 }
1447
1448 static void property_release_str(Object *obj, const char *name,
1449                                  void *opaque)
1450 {
1451     StringProperty *prop = opaque;
1452     g_free(prop);
1453 }
1454
1455 void object_property_add_str(Object *obj, const char *name,
1456                            char *(*get)(Object *, Error **),
1457                            void (*set)(Object *, const char *, Error **),
1458                            Error **errp)
1459 {
1460     Error *local_err = NULL;
1461     StringProperty *prop = g_malloc0(sizeof(*prop));
1462
1463     prop->get = get;
1464     prop->set = set;
1465
1466     object_property_add(obj, name, "string",
1467                         get ? property_get_str : NULL,
1468                         set ? property_set_str : NULL,
1469                         property_release_str,
1470                         prop, &local_err);
1471     if (local_err) {
1472         error_propagate(errp, local_err);
1473         g_free(prop);
1474     }
1475 }
1476
1477 typedef struct BoolProperty
1478 {
1479     bool (*get)(Object *, Error **);
1480     void (*set)(Object *, bool, Error **);
1481 } BoolProperty;
1482
1483 static void property_get_bool(Object *obj, Visitor *v, void *opaque,
1484                               const char *name, Error **errp)
1485 {
1486     BoolProperty *prop = opaque;
1487     bool value;
1488
1489     value = prop->get(obj, errp);
1490     visit_type_bool(v, &value, name, errp);
1491 }
1492
1493 static void property_set_bool(Object *obj, Visitor *v, void *opaque,
1494                               const char *name, Error **errp)
1495 {
1496     BoolProperty *prop = opaque;
1497     bool value;
1498     Error *local_err = NULL;
1499
1500     visit_type_bool(v, &value, name, &local_err);
1501     if (local_err) {
1502         error_propagate(errp, local_err);
1503         return;
1504     }
1505
1506     prop->set(obj, value, errp);
1507 }
1508
1509 static void property_release_bool(Object *obj, const char *name,
1510                                   void *opaque)
1511 {
1512     BoolProperty *prop = opaque;
1513     g_free(prop);
1514 }
1515
1516 void object_property_add_bool(Object *obj, const char *name,
1517                               bool (*get)(Object *, Error **),
1518                               void (*set)(Object *, bool, Error **),
1519                               Error **errp)
1520 {
1521     Error *local_err = NULL;
1522     BoolProperty *prop = g_malloc0(sizeof(*prop));
1523
1524     prop->get = get;
1525     prop->set = set;
1526
1527     object_property_add(obj, name, "bool",
1528                         get ? property_get_bool : NULL,
1529                         set ? property_set_bool : NULL,
1530                         property_release_bool,
1531                         prop, &local_err);
1532     if (local_err) {
1533         error_propagate(errp, local_err);
1534         g_free(prop);
1535     }
1536 }
1537
1538 static char *qdev_get_type(Object *obj, Error **errp)
1539 {
1540     return g_strdup(object_get_typename(obj));
1541 }
1542
1543 static void property_get_uint8_ptr(Object *obj, Visitor *v,
1544                                    void *opaque, const char *name,
1545                                    Error **errp)
1546 {
1547     uint8_t value = *(uint8_t *)opaque;
1548     visit_type_uint8(v, &value, name, errp);
1549 }
1550
1551 static void property_get_uint16_ptr(Object *obj, Visitor *v,
1552                                    void *opaque, const char *name,
1553                                    Error **errp)
1554 {
1555     uint16_t value = *(uint16_t *)opaque;
1556     visit_type_uint16(v, &value, name, errp);
1557 }
1558
1559 static void property_get_uint32_ptr(Object *obj, Visitor *v,
1560                                    void *opaque, const char *name,
1561                                    Error **errp)
1562 {
1563     uint32_t value = *(uint32_t *)opaque;
1564     visit_type_uint32(v, &value, name, errp);
1565 }
1566
1567 static void property_get_uint64_ptr(Object *obj, Visitor *v,
1568                                    void *opaque, const char *name,
1569                                    Error **errp)
1570 {
1571     uint64_t value = *(uint64_t *)opaque;
1572     visit_type_uint64(v, &value, name, errp);
1573 }
1574
1575 void object_property_add_uint8_ptr(Object *obj, const char *name,
1576                                    const uint8_t *v, Error **errp)
1577 {
1578     object_property_add(obj, name, "uint8", property_get_uint8_ptr,
1579                         NULL, NULL, (void *)v, errp);
1580 }
1581
1582 void object_property_add_uint16_ptr(Object *obj, const char *name,
1583                                     const uint16_t *v, Error **errp)
1584 {
1585     object_property_add(obj, name, "uint16", property_get_uint16_ptr,
1586                         NULL, NULL, (void *)v, errp);
1587 }
1588
1589 void object_property_add_uint32_ptr(Object *obj, const char *name,
1590                                     const uint32_t *v, Error **errp)
1591 {
1592     object_property_add(obj, name, "uint32", property_get_uint32_ptr,
1593                         NULL, NULL, (void *)v, errp);
1594 }
1595
1596 void object_property_add_uint64_ptr(Object *obj, const char *name,
1597                                     const uint64_t *v, Error **errp)
1598 {
1599     object_property_add(obj, name, "uint64", property_get_uint64_ptr,
1600                         NULL, NULL, (void *)v, errp);
1601 }
1602
1603 typedef struct {
1604     Object *target_obj;
1605     const char *target_name;
1606 } AliasProperty;
1607
1608 static void property_get_alias(Object *obj, struct Visitor *v, void *opaque,
1609                                const char *name, Error **errp)
1610 {
1611     AliasProperty *prop = opaque;
1612
1613     object_property_get(prop->target_obj, v, prop->target_name, errp);
1614 }
1615
1616 static void property_set_alias(Object *obj, struct Visitor *v, void *opaque,
1617                                const char *name, Error **errp)
1618 {
1619     AliasProperty *prop = opaque;
1620
1621     object_property_set(prop->target_obj, v, prop->target_name, errp);
1622 }
1623
1624 static Object *property_resolve_alias(Object *obj, void *opaque,
1625                                       const gchar *part)
1626 {
1627     AliasProperty *prop = opaque;
1628
1629     return object_resolve_path_component(prop->target_obj, prop->target_name);
1630 }
1631
1632 static void property_release_alias(Object *obj, const char *name, void *opaque)
1633 {
1634     AliasProperty *prop = opaque;
1635
1636     g_free(prop);
1637 }
1638
1639 void object_property_add_alias(Object *obj, const char *name,
1640                                Object *target_obj, const char *target_name,
1641                                Error **errp)
1642 {
1643     AliasProperty *prop;
1644     ObjectProperty *op;
1645     ObjectProperty *target_prop;
1646     gchar *prop_type;
1647     Error *local_err = NULL;
1648
1649     target_prop = object_property_find(target_obj, target_name, errp);
1650     if (!target_prop) {
1651         return;
1652     }
1653
1654     if (object_property_is_child(target_prop)) {
1655         prop_type = g_strdup_printf("link%s",
1656                                     target_prop->type + strlen("child"));
1657     } else {
1658         prop_type = g_strdup(target_prop->type);
1659     }
1660
1661     prop = g_malloc(sizeof(*prop));
1662     prop->target_obj = target_obj;
1663     prop->target_name = target_name;
1664
1665     op = object_property_add(obj, name, prop_type,
1666                              property_get_alias,
1667                              property_set_alias,
1668                              property_release_alias,
1669                              prop, &local_err);
1670     if (local_err) {
1671         error_propagate(errp, local_err);
1672         g_free(prop);
1673         goto out;
1674     }
1675     op->resolve = property_resolve_alias;
1676
1677     object_property_set_description(obj, name,
1678                                     target_prop->description,
1679                                     &error_abort);
1680
1681 out:
1682     g_free(prop_type);
1683 }
1684
1685 void object_property_set_description(Object *obj, const char *name,
1686                                      const char *description, Error **errp)
1687 {
1688     ObjectProperty *op;
1689
1690     op = object_property_find(obj, name, errp);
1691     if (!op) {
1692         return;
1693     }
1694
1695     g_free(op->description);
1696     op->description = g_strdup(description);
1697 }
1698
1699 static void object_instance_init(Object *obj)
1700 {
1701     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
1702 }
1703
1704 static void register_types(void)
1705 {
1706     static TypeInfo interface_info = {
1707         .name = TYPE_INTERFACE,
1708         .class_size = sizeof(InterfaceClass),
1709         .abstract = true,
1710     };
1711
1712     static TypeInfo object_info = {
1713         .name = TYPE_OBJECT,
1714         .instance_size = sizeof(Object),
1715         .instance_init = object_instance_init,
1716         .abstract = true,
1717     };
1718
1719     type_interface = type_register_internal(&interface_info);
1720     type_register_internal(&object_info);
1721 }
1722
1723 type_init(register_types)