qom/object.c

   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 #include "qom/object.h"
  14 #include "qemu-common.h"
  15 #include "qapi/visitor.h"
  16 #include "qapi/string-input-visitor.h"
  17 #include "qapi/string-output-visitor.h"
  18 #include "qapi/qmp/qerror.h"
  19 #include "trace.h"
  20
  21 /* TODO: replace QObject with a simpler visitor to avoid a dependency
  22  * of the QOM core on QObject?  */
  23 #include "qom/qom-qobject.h"
  24 #include "qapi/qmp/qobject.h"
  25 #include "qapi/qmp/qbool.h"
  26 #include "qapi/qmp/qint.h"
  27 #include "qapi/qmp/qstring.h"
  28
  29 #define MAX_INTERFACES 32
  30
  31 typedef struct InterfaceImpl InterfaceImpl;
  32 typedef struct TypeImpl TypeImpl;
  33
  34 struct InterfaceImpl
  35 {
  36     const char *typename;
  37 };
  38
  39 struct TypeImpl
  40 {
  41     const char *name;
  42
  43     size_t class_size;
  44
  45     size_t instance_size;
  46
  47     void (*class_init)(ObjectClass *klass, void *data);
  48     void (*class_base_init)(ObjectClass *klass, void *data);
  49     void (*class_finalize)(ObjectClass *klass, void *data);
  50
  51     void *class_data;
  52
  53     void (*instance_init)(Object *obj);
  54     void (*instance_post_init)(Object *obj);
  55     void (*instance_finalize)(Object *obj);
  56
  57     bool abstract;
  58
  59     const char *parent;
  60     TypeImpl *parent_type;
  61
  62     ObjectClass *class;
  63
  64     int num_interfaces;
  65     InterfaceImpl interfaces[MAX_INTERFACES];
  66 };
  67
  68 static Type type_interface;
  69
  70 static GHashTable *type_table_get(void)
  71 {
  72     static GHashTable *type_table;
  73
  74     if (type_table == NULL) {
  75         type_table = g_hash_table_new(g_str_hash, g_str_equal);
  76     }
  77
  78     return type_table;
  79 }
  80
  81 static void type_table_add(TypeImpl *ti)
  82 {
  83     g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
  84 }
  85
  86 static TypeImpl *type_table_lookup(const char *name)
  87 {
  88     return g_hash_table_lookup(type_table_get(), name);
  89 }
  90
  91 static TypeImpl *type_register_internal(const TypeInfo *info)
  92 {
  93     TypeImpl *ti = g_malloc0(sizeof(*ti));
  94     int i;
  95
  96     g_assert(info->name != NULL);
  97
  98     if (type_table_lookup(info->name) != NULL) {
  99         fprintf(stderr, "Registering `%s' which already exists\n", info->name);
 100         abort();
 101     }
 102
 103     ti->name = g_strdup(info->name);
 104     ti->parent = g_strdup(info->parent);
 105
 106     ti->class_size = info->class_size;
 107     ti->instance_size = info->instance_size;
 108
 109     ti->class_init = info->class_init;
 110     ti->class_base_init = info->class_base_init;
 111     ti->class_finalize = info->class_finalize;
 112     ti->class_data = info->class_data;
 113
 114     ti->instance_init = info->instance_init;
 115     ti->instance_post_init = info->instance_post_init;
 116     ti->instance_finalize = info->instance_finalize;
 117
 118     ti->abstract = info->abstract;
 119
 120     for (i = 0; info->interfaces && info->interfaces[i].type; i++) {
 121         ti->interfaces[i].typename = g_strdup(info->interfaces[i].type);
 122     }
 123     ti->num_interfaces = i;
 124
 125     type_table_add(ti);
 126
 127     return ti;
 128 }
 129
 130 TypeImpl *type_register(const TypeInfo *info)
 131 {
 132     assert(info->parent);
 133     return type_register_internal(info);
 134 }
 135
 136 TypeImpl *type_register_static(const TypeInfo *info)
 137 {
 138     return type_register(info);
 139 }
 140
 141 static TypeImpl *type_get_by_name(const char *name)
 142 {
 143     if (name == NULL) {
 144         return NULL;
 145     }
 146
 147     return type_table_lookup(name);
 148 }
 149
 150 static TypeImpl *type_get_parent(TypeImpl *type)
 151 {
 152     if (!type->parent_type && type->parent) {
 153         type->parent_type = type_get_by_name(type->parent);
 154         g_assert(type->parent_type != NULL);
 155     }
 156
 157     return type->parent_type;
 158 }
 159
 160 static bool type_has_parent(TypeImpl *type)
 161 {
 162     return (type->parent != NULL);
 163 }
 164
 165 static size_t type_class_get_size(TypeImpl *ti)
 166 {
 167     if (ti->class_size) {
 168         return ti->class_size;
 169     }
 170
 171     if (type_has_parent(ti)) {
 172         return type_class_get_size(type_get_parent(ti));
 173     }
 174
 175     return sizeof(ObjectClass);
 176 }
 177
 178 static size_t type_object_get_size(TypeImpl *ti)
 179 {
 180     if (ti->instance_size) {
 181         return ti->instance_size;
 182     }
 183
 184     if (type_has_parent(ti)) {
 185         return type_object_get_size(type_get_parent(ti));
 186     }
 187
 188     return 0;
 189 }
 190
 191 static bool type_is_ancestor(TypeImpl *type, TypeImpl *target_type)
 192 {
 193     assert(target_type);
 194
 195     /* Check if typename is a direct ancestor of type */
 196     while (type) {
 197         if (type == target_type) {
 198             return true;
 199         }
 200
 201         type = type_get_parent(type);
 202     }
 203
 204     return false;
 205 }
 206
 207 static void type_initialize(TypeImpl *ti);
 208
 209 static void type_initialize_interface(TypeImpl *ti, const char *parent)
 210 {
 211     InterfaceClass *new_iface;
 212     TypeInfo info = { };
 213     TypeImpl *iface_impl;
 214
 215     info.parent = parent;
 216     info.name = g_strdup_printf("%s::%s", ti->name, info.parent);
 217     info.abstract = true;
 218
 219     iface_impl = type_register(&info);
 220     type_initialize(iface_impl);
 221     g_free((char *)info.name);
 222
 223     new_iface = (InterfaceClass *)iface_impl->class;
 224     new_iface->concrete_class = ti->class;
 225
 226     ti->class->interfaces = g_slist_append(ti->class->interfaces,
 227                                            iface_impl->class);
 228 }
 229
 230 static void type_initialize(TypeImpl *ti)
 231 {
 232     TypeImpl *parent;
 233
 234     if (ti->class) {
 235         return;
 236     }
 237
 238     ti->class_size = type_class_get_size(ti);
 239     ti->instance_size = type_object_get_size(ti);
 240
 241     ti->class = g_malloc0(ti->class_size);
 242
 243     parent = type_get_parent(ti);
 244     if (parent) {
 245         type_initialize(parent);
 246         GSList *e;
 247         int i;
 248
 249         g_assert(parent->class_size <= ti->class_size);
 250         memcpy(ti->class, parent->class, parent->class_size);
 251         ti->class->interfaces = NULL;
 252
 253         for (e = parent->class->interfaces; e; e = e->next) {
 254             ObjectClass *iface = e->data;
 255             type_initialize_interface(ti, object_class_get_name(iface));
 256         }
 257
 258         for (i = 0; i < ti->num_interfaces; i++) {
 259             TypeImpl *t = type_get_by_name(ti->interfaces[i].typename);
 260             for (e = ti->class->interfaces; e; e = e->next) {
 261                 TypeImpl *target_type = OBJECT_CLASS(e->data)->type;
 262
 263                 if (type_is_ancestor(target_type, t)) {
 264                     break;
 265                 }
 266             }
 267
 268             if (e) {
 269                 continue;
 270             }
 271
 272             type_initialize_interface(ti, ti->interfaces[i].typename);
 273         }
 274     }
 275
 276     ti->class->type = ti;
 277
 278     while (parent) {
 279         if (parent->class_base_init) {
 280             parent->class_base_init(ti->class, ti->class_data);
 281         }
 282         parent = type_get_parent(parent);
 283     }
 284
 285     if (ti->class_init) {
 286         ti->class_init(ti->class, ti->class_data);
 287     }
 288
 289
 290 }
 291
 292 static void object_init_with_type(Object *obj, TypeImpl *ti)
 293 {
 294     if (type_has_parent(ti)) {
 295         object_init_with_type(obj, type_get_parent(ti));
 296     }
 297
 298     if (ti->instance_init) {
 299         ti->instance_init(obj);
 300     }
 301 }
 302
 303 static void object_post_init_with_type(Object *obj, TypeImpl *ti)
 304 {
 305     if (ti->instance_post_init) {
 306         ti->instance_post_init(obj);
 307     }
 308
 309     if (type_has_parent(ti)) {
 310         object_post_init_with_type(obj, type_get_parent(ti));
 311     }
 312 }
 313
 314 void object_initialize_with_type(void *data, TypeImpl *type)
 315 {
 316     Object *obj = data;
 317
 318     g_assert(type != NULL);
 319     type_initialize(type);
 320
 321     g_assert(type->instance_size >= sizeof(Object));
 322     g_assert(type->abstract == false);
 323
 324     memset(obj, 0, type->instance_size);
 325     obj->class = type->class;
 326     object_ref(obj);
 327     QTAILQ_INIT(&obj->properties);
 328     object_init_with_type(obj, type);
 329     object_post_init_with_type(obj, type);
 330 }
 331
 332 void object_initialize(void *data, const char *typename)
 333 {
 334     TypeImpl *type = type_get_by_name(typename);
 335
 336     object_initialize_with_type(data, type);
 337 }
 338
 339 static inline bool object_property_is_child(ObjectProperty *prop)
 340 {
 341     return strstart(prop->type, "child<", NULL);
 342 }
 343
 344 static inline bool object_property_is_link(ObjectProperty *prop)
 345 {
 346     return strstart(prop->type, "link<", NULL);
 347 }
 348
 349 static void object_property_del_all(Object *obj)
 350 {
 351     while (!QTAILQ_EMPTY(&obj->properties)) {
 352         ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
 353
 354         QTAILQ_REMOVE(&obj->properties, prop, node);
 355
 356         if (prop->release) {
 357             prop->release(obj, prop->name, prop->opaque);
 358         }
 359
 360         g_free(prop->name);
 361         g_free(prop->type);
 362         g_free(prop);
 363     }
 364 }
 365
 366 static void object_property_del_child(Object *obj, Object *child, Error **errp)
 367 {
 368     ObjectProperty *prop;
 369
 370     QTAILQ_FOREACH(prop, &obj->properties, node) {
 371         if (object_property_is_child(prop) && prop->opaque == child) {
 372             object_property_del(obj, prop->name, errp);
 373             break;
 374         }
 375     }
 376 }
 377
 378 void object_unparent(Object *obj)
 379 {
 380     if (!obj->parent) {
 381         return;
 382     }
 383
 384     object_ref(obj);
 385     if (obj->class->unparent) {
 386         (obj->class->unparent)(obj);
 387     }
 388     if (obj->parent) {
 389         object_property_del_child(obj->parent, obj, NULL);
 390     }
 391     object_unref(obj);
 392 }
 393
 394 static void object_deinit(Object *obj, TypeImpl *type)
 395 {
 396     if (type->instance_finalize) {
 397         type->instance_finalize(obj);
 398     }
 399
 400     if (type_has_parent(type)) {
 401         object_deinit(obj, type_get_parent(type));
 402     }
 403 }
 404
 405 static void object_finalize(void *data)
 406 {
 407     Object *obj = data;
 408     TypeImpl *ti = obj->class->type;
 409
 410     object_deinit(obj, ti);
 411     object_property_del_all(obj);
 412
 413     g_assert(obj->ref == 0);
 414     if (obj->free) {
 415         obj->free(obj);
 416     }
 417 }
 418
 419 Object *object_new_with_type(Type type)
 420 {
 421     Object *obj;
 422
 423     g_assert(type != NULL);
 424     type_initialize(type);
 425
 426     obj = g_malloc(type->instance_size);
 427     object_initialize_with_type(obj, type);
 428     obj->free = g_free;
 429
 430     return obj;
 431 }
 432
 433 Object *object_new(const char *typename)
 434 {
 435     TypeImpl *ti = type_get_by_name(typename);
 436
 437     return object_new_with_type(ti);
 438 }
 439
 440 Object *object_dynamic_cast(Object *obj, const char *typename)
 441 {
 442     if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) {
 443         return obj;
 444     }
 445
 446     return NULL;
 447 }
 448
 449 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
 450                                    const char *file, int line, const char *func)
 451 {
 452     trace_object_dynamic_cast_assert(obj ? obj->class->type->name : "(null)",
 453                                      typename, file, line, func);
 454
 455 #ifdef CONFIG_QOM_CAST_DEBUG
 456     int i;
 457     Object *inst;
 458
 459     for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
 460         if (obj->class->cast_cache[i] == typename) {
 461             goto out;
 462         }
 463     }
 464
 465     inst = object_dynamic_cast(obj, typename);
 466
 467     if (!inst && obj) {
 468         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 469                 file, line, func, obj, typename);
 470         abort();
 471     }
 472
 473     assert(obj == inst);
 474
 475     if (obj && obj == inst) {
 476         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 477             obj->class->cast_cache[i - 1] = obj->class->cast_cache[i];
 478         }
 479         obj->class->cast_cache[i - 1] = typename;
 480     }
 481
 482 out:
 483 #endif
 484     return obj;
 485 }
 486
 487 ObjectClass *object_class_dynamic_cast(ObjectClass *class,
 488                                        const char *typename)
 489 {
 490     ObjectClass *ret = NULL;
 491     TypeImpl *target_type;
 492     TypeImpl *type;
 493
 494     if (!class) {
 495         return NULL;
 496     }
 497
 498     /* A simple fast path that can trigger a lot for leaf classes.  */
 499     type = class->type;
 500     if (type->name == typename) {
 501         return class;
 502     }
 503
 504     target_type = type_get_by_name(typename);
 505     if (!target_type) {
 506         /* target class type unknown, so fail the cast */
 507         return NULL;
 508     }
 509
 510     if (type->class->interfaces &&
 511             type_is_ancestor(target_type, type_interface)) {
 512         int found = 0;
 513         GSList *i;
 514
 515         for (i = class->interfaces; i; i = i->next) {
 516             ObjectClass *target_class = i->data;
 517
 518             if (type_is_ancestor(target_class->type, target_type)) {
 519                 ret = target_class;
 520                 found++;
 521             }
 522          }
 523
 524         /* The match was ambiguous, don't allow a cast */
 525         if (found > 1) {
 526             ret = NULL;
 527         }
 528     } else if (type_is_ancestor(type, target_type)) {
 529         ret = class;
 530     }
 531
 532     return ret;
 533 }
 534
 535 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
 536                                               const char *typename,
 537                                               const char *file, int line,
 538                                               const char *func)
 539 {
 540     ObjectClass *ret;
 541
 542     trace_object_class_dynamic_cast_assert(class ? class->type->name : "(null)",
 543                                            typename, file, line, func);
 544
 545 #ifdef CONFIG_QOM_CAST_DEBUG
 546     int i;
 547
 548     for (i = 0; class && i < OBJECT_CLASS_CAST_CACHE; i++) {
 549         if (class->cast_cache[i] == typename) {
 550             ret = class;
 551             goto out;
 552         }
 553     }
 554 #else
 555     if (!class || !class->interfaces) {
 556         return class;
 557     }
 558 #endif
 559
 560     ret = object_class_dynamic_cast(class, typename);
 561     if (!ret && class) {
 562         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 563                 file, line, func, class, typename);
 564         abort();
 565     }
 566
 567 #ifdef CONFIG_QOM_CAST_DEBUG
 568     if (class && ret == class) {
 569         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 570             class->cast_cache[i - 1] = class->cast_cache[i];
 571         }
 572         class->cast_cache[i - 1] = typename;
 573     }
 574 out:
 575 #endif
 576     return ret;
 577 }
 578
 579 const char *object_get_typename(Object *obj)
 580 {
 581     return obj->class->type->name;
 582 }
 583
 584 ObjectClass *object_get_class(Object *obj)
 585 {
 586     return obj->class;
 587 }
 588
 589 bool object_class_is_abstract(ObjectClass *klass)
 590 {
 591     return klass->type->abstract;
 592 }
 593
 594 const char *object_class_get_name(ObjectClass *klass)
 595 {
 596     return klass->type->name;
 597 }
 598
 599 ObjectClass *object_class_by_name(const char *typename)
 600 {
 601     TypeImpl *type = type_get_by_name(typename);
 602
 603     if (!type) {
 604         return NULL;
 605     }
 606
 607     type_initialize(type);
 608
 609     return type->class;
 610 }
 611
 612 ObjectClass *object_class_get_parent(ObjectClass *class)
 613 {
 614     TypeImpl *type = type_get_parent(class->type);
 615
 616     if (!type) {
 617         return NULL;
 618     }
 619
 620     type_initialize(type);
 621
 622     return type->class;
 623 }
 624
 625 typedef struct OCFData
 626 {
 627     void (*fn)(ObjectClass *klass, void *opaque);
 628     const char *implements_type;
 629     bool include_abstract;
 630     void *opaque;
 631 } OCFData;
 632
 633 static void object_class_foreach_tramp(gpointer key, gpointer value,
 634                                        gpointer opaque)
 635 {
 636     OCFData *data = opaque;
 637     TypeImpl *type = value;
 638     ObjectClass *k;
 639
 640     type_initialize(type);
 641     k = type->class;
 642
 643     if (!data->include_abstract && type->abstract) {
 644         return;
 645     }
 646
 647     if (data->implements_type &&
 648         !object_class_dynamic_cast(k, data->implements_type)) {
 649         return;
 650     }
 651
 652     data->fn(k, data->opaque);
 653 }
 654
 655 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 656                           const char *implements_type, bool include_abstract,
 657                           void *opaque)
 658 {
 659     OCFData data = { fn, implements_type, include_abstract, opaque };
 660
 661     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 662 }
 663
 664 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
 665                          void *opaque)
 666 {
 667     ObjectProperty *prop;
 668     int ret = 0;
 669
 670     QTAILQ_FOREACH(prop, &obj->properties, node) {
 671         if (object_property_is_child(prop)) {
 672             ret = fn(prop->opaque, opaque);
 673             if (ret != 0) {
 674                 break;
 675             }
 676         }
 677     }
 678     return ret;
 679 }
 680
 681 static void object_class_get_list_tramp(ObjectClass *klass, void *opaque)
 682 {
 683     GSList **list = opaque;
 684
 685     *list = g_slist_prepend(*list, klass);
 686 }
 687
 688 GSList *object_class_get_list(const char *implements_type,
 689                               bool include_abstract)
 690 {
 691     GSList *list = NULL;
 692
 693     object_class_foreach(object_class_get_list_tramp,
 694                          implements_type, include_abstract, &list);
 695     return list;
 696 }
 697
 698 void object_ref(Object *obj)
 699 {
 700      atomic_inc(&obj->ref);
 701 }
 702
 703 void object_unref(Object *obj)
 704 {
 705     g_assert(obj->ref > 0);
 706
 707     /* parent always holds a reference to its children */
 708     if (atomic_fetch_dec(&obj->ref) == 1) {
 709         object_finalize(obj);
 710     }
 711 }
 712
 713 void object_property_add(Object *obj, const char *name, const char *type,
 714                          ObjectPropertyAccessor *get,
 715                          ObjectPropertyAccessor *set,
 716                          ObjectPropertyRelease *release,
 717                          void *opaque, Error **errp)
 718 {
 719     ObjectProperty *prop;
 720
 721     QTAILQ_FOREACH(prop, &obj->properties, node) {
 722         if (strcmp(prop->name, name) == 0) {
 723             error_setg(errp, "attempt to add duplicate property '%s'"
 724                        " to object (type '%s')", name,
 725                        object_get_typename(obj));
 726             return;
 727         }
 728     }
 729
 730     prop = g_malloc0(sizeof(*prop));
 731
 732     prop->name = g_strdup(name);
 733     prop->type = g_strdup(type);
 734
 735     prop->get = get;
 736     prop->set = set;
 737     prop->release = release;
 738     prop->opaque = opaque;
 739
 740     QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
 741 }
 742
 743 ObjectProperty *object_property_find(Object *obj, const char *name,
 744                                      Error **errp)
 745 {
 746     ObjectProperty *prop;
 747
 748     QTAILQ_FOREACH(prop, &obj->properties, node) {
 749         if (strcmp(prop->name, name) == 0) {
 750             return prop;
 751         }
 752     }
 753
 754     error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
 755     return NULL;
 756 }
 757
 758 void object_property_del(Object *obj, const char *name, Error **errp)
 759 {
 760     ObjectProperty *prop = object_property_find(obj, name, errp);
 761     if (prop == NULL) {
 762         return;
 763     }
 764
 765     if (prop->release) {
 766         prop->release(obj, name, prop->opaque);
 767     }
 768
 769     QTAILQ_REMOVE(&obj->properties, prop, node);
 770
 771     g_free(prop->name);
 772     g_free(prop->type);
 773     g_free(prop);
 774 }
 775
 776 void object_property_get(Object *obj, Visitor *v, const char *name,
 777                          Error **errp)
 778 {
 779     ObjectProperty *prop = object_property_find(obj, name, errp);
 780     if (prop == NULL) {
 781         return;
 782     }
 783
 784     if (!prop->get) {
 785         error_set(errp, QERR_PERMISSION_DENIED);
 786     } else {
 787         prop->get(obj, v, prop->opaque, name, errp);
 788     }
 789 }
 790
 791 void object_property_set(Object *obj, Visitor *v, const char *name,
 792                          Error **errp)
 793 {
 794     ObjectProperty *prop = object_property_find(obj, name, errp);
 795     if (prop == NULL) {
 796         return;
 797     }
 798
 799     if (!prop->set) {
 800         error_set(errp, QERR_PERMISSION_DENIED);
 801     } else {
 802         prop->set(obj, v, prop->opaque, name, errp);
 803     }
 804 }
 805
 806 void object_property_set_str(Object *obj, const char *value,
 807                              const char *name, Error **errp)
 808 {
 809     QString *qstr = qstring_from_str(value);
 810     object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
 811
 812     QDECREF(qstr);
 813 }
 814
 815 char *object_property_get_str(Object *obj, const char *name,
 816                               Error **errp)
 817 {
 818     QObject *ret = object_property_get_qobject(obj, name, errp);
 819     QString *qstring;
 820     char *retval;
 821
 822     if (!ret) {
 823         return NULL;
 824     }
 825     qstring = qobject_to_qstring(ret);
 826     if (!qstring) {
 827         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
 828         retval = NULL;
 829     } else {
 830         retval = g_strdup(qstring_get_str(qstring));
 831     }
 832
 833     QDECREF(qstring);
 834     return retval;
 835 }
 836
 837 void object_property_set_link(Object *obj, Object *value,
 838                               const char *name, Error **errp)
 839 {
 840     object_property_set_str(obj, object_get_canonical_path(value),
 841                             name, errp);
 842 }
 843
 844 Object *object_property_get_link(Object *obj, const char *name,
 845                                  Error **errp)
 846 {
 847     char *str = object_property_get_str(obj, name, errp);
 848     Object *target = NULL;
 849
 850     if (str && *str) {
 851         target = object_resolve_path(str, NULL);
 852         if (!target) {
 853             error_set(errp, QERR_DEVICE_NOT_FOUND, str);
 854         }
 855     }
 856
 857     g_free(str);
 858     return target;
 859 }
 860
 861 void object_property_set_bool(Object *obj, bool value,
 862                               const char *name, Error **errp)
 863 {
 864     QBool *qbool = qbool_from_int(value);
 865     object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
 866
 867     QDECREF(qbool);
 868 }
 869
 870 bool object_property_get_bool(Object *obj, const char *name,
 871                               Error **errp)
 872 {
 873     QObject *ret = object_property_get_qobject(obj, name, errp);
 874     QBool *qbool;
 875     bool retval;
 876
 877     if (!ret) {
 878         return false;
 879     }
 880     qbool = qobject_to_qbool(ret);
 881     if (!qbool) {
 882         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
 883         retval = false;
 884     } else {
 885         retval = qbool_get_int(qbool);
 886     }
 887
 888     QDECREF(qbool);
 889     return retval;
 890 }
 891
 892 void object_property_set_int(Object *obj, int64_t value,
 893                              const char *name, Error **errp)
 894 {
 895     QInt *qint = qint_from_int(value);
 896     object_property_set_qobject(obj, QOBJECT(qint), name, errp);
 897
 898     QDECREF(qint);
 899 }
 900
 901 int64_t object_property_get_int(Object *obj, const char *name,
 902                                 Error **errp)
 903 {
 904     QObject *ret = object_property_get_qobject(obj, name, errp);
 905     QInt *qint;
 906     int64_t retval;
 907
 908     if (!ret) {
 909         return -1;
 910     }
 911     qint = qobject_to_qint(ret);
 912     if (!qint) {
 913         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
 914         retval = -1;
 915     } else {
 916         retval = qint_get_int(qint);
 917     }
 918
 919     QDECREF(qint);
 920     return retval;
 921 }
 922
 923 void object_property_parse(Object *obj, const char *string,
 924                            const char *name, Error **errp)
 925 {
 926     StringInputVisitor *mi;
 927     mi = string_input_visitor_new(string);
 928     object_property_set(obj, string_input_get_visitor(mi), name, errp);
 929
 930     string_input_visitor_cleanup(mi);
 931 }
 932
 933 char *object_property_print(Object *obj, const char *name,
 934                             Error **errp)
 935 {
 936     StringOutputVisitor *mo;
 937     char *string;
 938
 939     mo = string_output_visitor_new();
 940     object_property_get(obj, string_output_get_visitor(mo), name, errp);
 941     string = string_output_get_string(mo);
 942     string_output_visitor_cleanup(mo);
 943     return string;
 944 }
 945
 946 const char *object_property_get_type(Object *obj, const char *name, Error **errp)
 947 {
 948     ObjectProperty *prop = object_property_find(obj, name, errp);
 949     if (prop == NULL) {
 950         return NULL;
 951     }
 952
 953     return prop->type;
 954 }
 955
 956 Object *object_get_root(void)
 957 {
 958     static Object *root;
 959
 960     if (!root) {
 961         root = object_new("container");
 962     }
 963
 964     return root;
 965 }
 966
 967 static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
 968                                       const char *name, Error **errp)
 969 {
 970     Object *child = opaque;
 971     gchar *path;
 972
 973     path = object_get_canonical_path(child);
 974     visit_type_str(v, &path, name, errp);
 975     g_free(path);
 976 }
 977
 978 static void object_finalize_child_property(Object *obj, const char *name,
 979                                            void *opaque)
 980 {
 981     Object *child = opaque;
 982
 983     object_unref(child);
 984 }
 985
 986 void object_property_add_child(Object *obj, const char *name,
 987                                Object *child, Error **errp)
 988 {
 989     gchar *type;
 990
 991     type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
 992
 993     object_property_add(obj, name, type, object_get_child_property,
 994                         NULL, object_finalize_child_property, child, errp);
 995
 996     object_ref(child);
 997     g_assert(child->parent == NULL);
 998     child->parent = obj;
 999
1000     g_free(type);
1001 }
1002
1003 static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
1004                                      const char *name, Error **errp)
1005 {
1006     Object **child = opaque;
1007     gchar *path;
1008
1009     if (*child) {
1010         path = object_get_canonical_path(*child);
1011         visit_type_str(v, &path, name, errp);
1012         g_free(path);
1013     } else {
1014         path = (gchar *)"";
1015         visit_type_str(v, &path, name, errp);
1016     }
1017 }
1018
1019 static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
1020                                      const char *name, Error **errp)
1021 {
1022     Object **child = opaque;
1023     Object *old_target;
1024     bool ambiguous = false;
1025     const char *type;
1026     char *path;
1027     gchar *target_type;
1028
1029     type = object_property_get_type(obj, name, NULL);
1030
1031     visit_type_str(v, &path, name, errp);
1032
1033     old_target = *child;
1034     *child = NULL;
1035
1036     if (strcmp(path, "") != 0) {
1037         Object *target;
1038
1039         /* Go from link<FOO> to FOO.  */
1040         target_type = g_strndup(&type[5], strlen(type) - 6);
1041         target = object_resolve_path_type(path, target_type, &ambiguous);
1042
1043         if (ambiguous) {
1044             error_set(errp, QERR_AMBIGUOUS_PATH, path);
1045         } else if (target) {
1046             object_ref(target);
1047             *child = target;
1048         } else {
1049             target = object_resolve_path(path, &ambiguous);
1050             if (target || ambiguous) {
1051                 error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
1052             } else {
1053                 error_set(errp, QERR_DEVICE_NOT_FOUND, path);
1054             }
1055         }
1056         g_free(target_type);
1057     }
1058
1059     g_free(path);
1060
1061     if (old_target != NULL) {
1062         object_unref(old_target);
1063     }
1064 }
1065
1066 void object_property_add_link(Object *obj, const char *name,
1067                               const char *type, Object **child,
1068                               Error **errp)
1069 {
1070     gchar *full_type;
1071
1072     full_type = g_strdup_printf("link<%s>", type);
1073
1074     object_property_add(obj, name, full_type,
1075                         object_get_link_property,
1076                         object_set_link_property,
1077                         NULL, child, errp);
1078
1079     g_free(full_type);
1080 }
1081
1082 gchar *object_get_canonical_path(Object *obj)
1083 {
1084     Object *root = object_get_root();
1085     char *newpath = NULL, *path = NULL;
1086
1087     while (obj != root) {
1088         ObjectProperty *prop = NULL;
1089
1090         g_assert(obj->parent != NULL);
1091
1092         QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
1093             if (!object_property_is_child(prop)) {
1094                 continue;
1095             }
1096
1097             if (prop->opaque == obj) {
1098                 if (path) {
1099                     newpath = g_strdup_printf("%s/%s", prop->name, path);
1100                     g_free(path);
1101                     path = newpath;
1102                 } else {
1103                     path = g_strdup(prop->name);
1104                 }
1105                 break;
1106             }
1107         }
1108
1109         g_assert(prop != NULL);
1110
1111         obj = obj->parent;
1112     }
1113
1114     newpath = g_strdup_printf("/%s", path);
1115     g_free(path);
1116
1117     return newpath;
1118 }
1119
1120 Object *object_resolve_path_component(Object *parent, const gchar *part)
1121 {
1122     ObjectProperty *prop = object_property_find(parent, part, NULL);
1123     if (prop == NULL) {
1124         return NULL;
1125     }
1126
1127     if (object_property_is_link(prop)) {
1128         return *(Object **)prop->opaque;
1129     } else if (object_property_is_child(prop)) {
1130         return prop->opaque;
1131     } else {
1132         return NULL;
1133     }
1134 }
1135
1136 static Object *object_resolve_abs_path(Object *parent,
1137                                           gchar **parts,
1138                                           const char *typename,
1139                                           int index)
1140 {
1141     Object *child;
1142
1143     if (parts[index] == NULL) {
1144         return object_dynamic_cast(parent, typename);
1145     }
1146
1147     if (strcmp(parts[index], "") == 0) {
1148         return object_resolve_abs_path(parent, parts, typename, index + 1);
1149     }
1150
1151     child = object_resolve_path_component(parent, parts[index]);
1152     if (!child) {
1153         return NULL;
1154     }
1155
1156     return object_resolve_abs_path(child, parts, typename, index + 1);
1157 }
1158
1159 static Object *object_resolve_partial_path(Object *parent,
1160                                               gchar **parts,
1161                                               const char *typename,
1162                                               bool *ambiguous)
1163 {
1164     Object *obj;
1165     ObjectProperty *prop;
1166
1167     obj = object_resolve_abs_path(parent, parts, typename, 0);
1168
1169     QTAILQ_FOREACH(prop, &parent->properties, node) {
1170         Object *found;
1171
1172         if (!object_property_is_child(prop)) {
1173             continue;
1174         }
1175
1176         found = object_resolve_partial_path(prop->opaque, parts,
1177                                             typename, ambiguous);
1178         if (found) {
1179             if (obj) {
1180                 if (ambiguous) {
1181                     *ambiguous = true;
1182                 }
1183                 return NULL;
1184             }
1185             obj = found;
1186         }
1187
1188         if (ambiguous && *ambiguous) {
1189             return NULL;
1190         }
1191     }
1192
1193     return obj;
1194 }
1195
1196 Object *object_resolve_path_type(const char *path, const char *typename,
1197                                  bool *ambiguous)
1198 {
1199     Object *obj;
1200     gchar **parts;
1201
1202     parts = g_strsplit(path, "/", 0);
1203     assert(parts);
1204
1205     if (parts[0] == NULL || strcmp(parts[0], "") != 0) {
1206         if (ambiguous) {
1207             *ambiguous = false;
1208         }
1209         obj = object_resolve_partial_path(object_get_root(), parts,
1210                                           typename, ambiguous);
1211     } else {
1212         obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
1213     }
1214
1215     g_strfreev(parts);
1216
1217     return obj;
1218 }
1219
1220 Object *object_resolve_path(const char *path, bool *ambiguous)
1221 {
1222     return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
1223 }
1224
1225 typedef struct StringProperty
1226 {
1227     char *(*get)(Object *, Error **);
1228     void (*set)(Object *, const char *, Error **);
1229 } StringProperty;
1230
1231 static void property_get_str(Object *obj, Visitor *v, void *opaque,
1232                              const char *name, Error **errp)
1233 {
1234     StringProperty *prop = opaque;
1235     char *value;
1236
1237     value = prop->get(obj, errp);
1238     if (value) {
1239         visit_type_str(v, &value, name, errp);
1240         g_free(value);
1241     }
1242 }
1243
1244 static void property_set_str(Object *obj, Visitor *v, void *opaque,
1245                              const char *name, Error **errp)
1246 {
1247     StringProperty *prop = opaque;
1248     char *value;
1249     Error *local_err = NULL;
1250
1251     visit_type_str(v, &value, name, &local_err);
1252     if (local_err) {
1253         error_propagate(errp, local_err);
1254         return;
1255     }
1256
1257     prop->set(obj, value, errp);
1258     g_free(value);
1259 }
1260
1261 static void property_release_str(Object *obj, const char *name,
1262                                  void *opaque)
1263 {
1264     StringProperty *prop = opaque;
1265     g_free(prop);
1266 }
1267
1268 void object_property_add_str(Object *obj, const char *name,
1269                            char *(*get)(Object *, Error **),
1270                            void (*set)(Object *, const char *, Error **),
1271                            Error **errp)
1272 {
1273     StringProperty *prop = g_malloc0(sizeof(*prop));
1274
1275     prop->get = get;
1276     prop->set = set;
1277
1278     object_property_add(obj, name, "string",
1279                         get ? property_get_str : NULL,
1280                         set ? property_set_str : NULL,
1281                         property_release_str,
1282                         prop, errp);
1283 }
1284
1285 typedef struct BoolProperty
1286 {
1287     bool (*get)(Object *, Error **);
1288     void (*set)(Object *, bool, Error **);
1289 } BoolProperty;
1290
1291 static void property_get_bool(Object *obj, Visitor *v, void *opaque,
1292                               const char *name, Error **errp)
1293 {
1294     BoolProperty *prop = opaque;
1295     bool value;
1296
1297     value = prop->get(obj, errp);
1298     visit_type_bool(v, &value, name, errp);
1299 }
1300
1301 static void property_set_bool(Object *obj, Visitor *v, void *opaque,
1302                               const char *name, Error **errp)
1303 {
1304     BoolProperty *prop = opaque;
1305     bool value;
1306     Error *local_err = NULL;
1307
1308     visit_type_bool(v, &value, name, &local_err);
1309     if (local_err) {
1310         error_propagate(errp, local_err);
1311         return;
1312     }
1313
1314     prop->set(obj, value, errp);
1315 }
1316
1317 static void property_release_bool(Object *obj, const char *name,
1318                                   void *opaque)
1319 {
1320     BoolProperty *prop = opaque;
1321     g_free(prop);
1322 }
1323
1324 void object_property_add_bool(Object *obj, const char *name,
1325                               bool (*get)(Object *, Error **),
1326                               void (*set)(Object *, bool, Error **),
1327                               Error **errp)
1328 {
1329     BoolProperty *prop = g_malloc0(sizeof(*prop));
1330
1331     prop->get = get;
1332     prop->set = set;
1333
1334     object_property_add(obj, name, "bool",
1335                         get ? property_get_bool : NULL,
1336                         set ? property_set_bool : NULL,
1337                         property_release_bool,
1338                         prop, errp);
1339 }
1340
1341 static char *qdev_get_type(Object *obj, Error **errp)
1342 {
1343     return g_strdup(object_get_typename(obj));
1344 }
1345
1346 static void object_instance_init(Object *obj)
1347 {
1348     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
1349 }
1350
1351 static void register_types(void)
1352 {
1353     static TypeInfo interface_info = {
1354         .name = TYPE_INTERFACE,
1355         .class_size = sizeof(InterfaceClass),
1356         .abstract = true,
1357     };
1358
1359     static TypeInfo object_info = {
1360         .name = TYPE_OBJECT,
1361         .instance_size = sizeof(Object),
1362         .instance_init = object_instance_init,
1363         .abstract = true,
1364     };
1365
1366     type_interface = type_register_internal(&interface_info);
1367     type_register_internal(&object_info);
1368 }
1369
1370 type_init(register_types)