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, size_t size, 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     g_assert(size >= type->instance_size);
 324
 325     memset(obj, 0, type->instance_size);
 326     obj->class = type->class;
 327     object_ref(obj);
 328     QTAILQ_INIT(&obj->properties);
 329     object_init_with_type(obj, type);
 330     object_post_init_with_type(obj, type);
 331 }
 332
 333 void object_initialize(void *data, size_t size, const char *typename)
 334 {
 335     TypeImpl *type = type_get_by_name(typename);
 336
 337     object_initialize_with_type(data, size, type);
 338 }
 339
 340 static inline bool object_property_is_child(ObjectProperty *prop)
 341 {
 342     return strstart(prop->type, "child<", NULL);
 343 }
 344
 345 static inline bool object_property_is_link(ObjectProperty *prop)
 346 {
 347     return strstart(prop->type, "link<", NULL);
 348 }
 349
 350 static void object_property_del_all(Object *obj)
 351 {
 352     while (!QTAILQ_EMPTY(&obj->properties)) {
 353         ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
 354
 355         QTAILQ_REMOVE(&obj->properties, prop, node);
 356
 357         if (prop->release) {
 358             prop->release(obj, prop->name, prop->opaque);
 359         }
 360
 361         g_free(prop->name);
 362         g_free(prop->type);
 363         g_free(prop);
 364     }
 365 }
 366
 367 static void object_property_del_child(Object *obj, Object *child, Error **errp)
 368 {
 369     ObjectProperty *prop;
 370
 371     QTAILQ_FOREACH(prop, &obj->properties, node) {
 372         if (object_property_is_child(prop) && prop->opaque == child) {
 373             object_property_del(obj, prop->name, errp);
 374             break;
 375         }
 376     }
 377 }
 378
 379 void object_unparent(Object *obj)
 380 {
 381     if (!obj->parent) {
 382         return;
 383     }
 384
 385     object_ref(obj);
 386     if (obj->class->unparent) {
 387         (obj->class->unparent)(obj);
 388     }
 389     if (obj->parent) {
 390         object_property_del_child(obj->parent, obj, NULL);
 391     }
 392     object_unref(obj);
 393 }
 394
 395 static void object_deinit(Object *obj, TypeImpl *type)
 396 {
 397     if (type->instance_finalize) {
 398         type->instance_finalize(obj);
 399     }
 400
 401     if (type_has_parent(type)) {
 402         object_deinit(obj, type_get_parent(type));
 403     }
 404 }
 405
 406 static void object_finalize(void *data)
 407 {
 408     Object *obj = data;
 409     TypeImpl *ti = obj->class->type;
 410
 411     object_deinit(obj, ti);
 412     object_property_del_all(obj);
 413
 414     g_assert(obj->ref == 0);
 415     if (obj->free) {
 416         obj->free(obj);
 417     }
 418 }
 419
 420 Object *object_new_with_type(Type type)
 421 {
 422     Object *obj;
 423
 424     g_assert(type != NULL);
 425     type_initialize(type);
 426
 427     obj = g_malloc(type->instance_size);
 428     object_initialize_with_type(obj, type->instance_size, type);
 429     obj->free = g_free;
 430
 431     return obj;
 432 }
 433
 434 Object *object_new(const char *typename)
 435 {
 436     TypeImpl *ti = type_get_by_name(typename);
 437
 438     return object_new_with_type(ti);
 439 }
 440
 441 Object *object_dynamic_cast(Object *obj, const char *typename)
 442 {
 443     if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) {
 444         return obj;
 445     }
 446
 447     return NULL;
 448 }
 449
 450 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
 451                                    const char *file, int line, const char *func)
 452 {
 453     trace_object_dynamic_cast_assert(obj ? obj->class->type->name : "(null)",
 454                                      typename, file, line, func);
 455
 456 #ifdef CONFIG_QOM_CAST_DEBUG
 457     int i;
 458     Object *inst;
 459
 460     for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
 461         if (obj->class->cast_cache[i] == typename) {
 462             goto out;
 463         }
 464     }
 465
 466     inst = object_dynamic_cast(obj, typename);
 467
 468     if (!inst && obj) {
 469         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 470                 file, line, func, obj, typename);
 471         abort();
 472     }
 473
 474     assert(obj == inst);
 475
 476     if (obj && obj == inst) {
 477         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 478             obj->class->cast_cache[i - 1] = obj->class->cast_cache[i];
 479         }
 480         obj->class->cast_cache[i - 1] = typename;
 481     }
 482
 483 out:
 484 #endif
 485     return obj;
 486 }
 487
 488 ObjectClass *object_class_dynamic_cast(ObjectClass *class,
 489                                        const char *typename)
 490 {
 491     ObjectClass *ret = NULL;
 492     TypeImpl *target_type;
 493     TypeImpl *type;
 494
 495     if (!class) {
 496         return NULL;
 497     }
 498
 499     /* A simple fast path that can trigger a lot for leaf classes.  */
 500     type = class->type;
 501     if (type->name == typename) {
 502         return class;
 503     }
 504
 505     target_type = type_get_by_name(typename);
 506     if (!target_type) {
 507         /* target class type unknown, so fail the cast */
 508         return NULL;
 509     }
 510
 511     if (type->class->interfaces &&
 512             type_is_ancestor(target_type, type_interface)) {
 513         int found = 0;
 514         GSList *i;
 515
 516         for (i = class->interfaces; i; i = i->next) {
 517             ObjectClass *target_class = i->data;
 518
 519             if (type_is_ancestor(target_class->type, target_type)) {
 520                 ret = target_class;
 521                 found++;
 522             }
 523          }
 524
 525         /* The match was ambiguous, don't allow a cast */
 526         if (found > 1) {
 527             ret = NULL;
 528         }
 529     } else if (type_is_ancestor(type, target_type)) {
 530         ret = class;
 531     }
 532
 533     return ret;
 534 }
 535
 536 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
 537                                               const char *typename,
 538                                               const char *file, int line,
 539                                               const char *func)
 540 {
 541     ObjectClass *ret;
 542
 543     trace_object_class_dynamic_cast_assert(class ? class->type->name : "(null)",
 544                                            typename, file, line, func);
 545
 546 #ifdef CONFIG_QOM_CAST_DEBUG
 547     int i;
 548
 549     for (i = 0; class && i < OBJECT_CLASS_CAST_CACHE; i++) {
 550         if (class->cast_cache[i] == typename) {
 551             ret = class;
 552             goto out;
 553         }
 554     }
 555 #else
 556     if (!class || !class->interfaces) {
 557         return class;
 558     }
 559 #endif
 560
 561     ret = object_class_dynamic_cast(class, typename);
 562     if (!ret && class) {
 563         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 564                 file, line, func, class, typename);
 565         abort();
 566     }
 567
 568 #ifdef CONFIG_QOM_CAST_DEBUG
 569     if (class && ret == class) {
 570         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 571             class->cast_cache[i - 1] = class->cast_cache[i];
 572         }
 573         class->cast_cache[i - 1] = typename;
 574     }
 575 out:
 576 #endif
 577     return ret;
 578 }
 579
 580 const char *object_get_typename(Object *obj)
 581 {
 582     return obj->class->type->name;
 583 }
 584
 585 ObjectClass *object_get_class(Object *obj)
 586 {
 587     return obj->class;
 588 }
 589
 590 bool object_class_is_abstract(ObjectClass *klass)
 591 {
 592     return klass->type->abstract;
 593 }
 594
 595 const char *object_class_get_name(ObjectClass *klass)
 596 {
 597     return klass->type->name;
 598 }
 599
 600 ObjectClass *object_class_by_name(const char *typename)
 601 {
 602     TypeImpl *type = type_get_by_name(typename);
 603
 604     if (!type) {
 605         return NULL;
 606     }
 607
 608     type_initialize(type);
 609
 610     return type->class;
 611 }
 612
 613 ObjectClass *object_class_get_parent(ObjectClass *class)
 614 {
 615     TypeImpl *type = type_get_parent(class->type);
 616
 617     if (!type) {
 618         return NULL;
 619     }
 620
 621     type_initialize(type);
 622
 623     return type->class;
 624 }
 625
 626 typedef struct OCFData
 627 {
 628     void (*fn)(ObjectClass *klass, void *opaque);
 629     const char *implements_type;
 630     bool include_abstract;
 631     void *opaque;
 632 } OCFData;
 633
 634 static void object_class_foreach_tramp(gpointer key, gpointer value,
 635                                        gpointer opaque)
 636 {
 637     OCFData *data = opaque;
 638     TypeImpl *type = value;
 639     ObjectClass *k;
 640
 641     type_initialize(type);
 642     k = type->class;
 643
 644     if (!data->include_abstract && type->abstract) {
 645         return;
 646     }
 647
 648     if (data->implements_type &&
 649         !object_class_dynamic_cast(k, data->implements_type)) {
 650         return;
 651     }
 652
 653     data->fn(k, data->opaque);
 654 }
 655
 656 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 657                           const char *implements_type, bool include_abstract,
 658                           void *opaque)
 659 {
 660     OCFData data = { fn, implements_type, include_abstract, opaque };
 661
 662     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 663 }
 664
 665 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
 666                          void *opaque)
 667 {
 668     ObjectProperty *prop;
 669     int ret = 0;
 670
 671     QTAILQ_FOREACH(prop, &obj->properties, node) {
 672         if (object_property_is_child(prop)) {
 673             ret = fn(prop->opaque, opaque);
 674             if (ret != 0) {
 675                 break;
 676             }
 677         }
 678     }
 679     return ret;
 680 }
 681
 682 static void object_class_get_list_tramp(ObjectClass *klass, void *opaque)
 683 {
 684     GSList **list = opaque;
 685
 686     *list = g_slist_prepend(*list, klass);
 687 }
 688
 689 GSList *object_class_get_list(const char *implements_type,
 690                               bool include_abstract)
 691 {
 692     GSList *list = NULL;
 693
 694     object_class_foreach(object_class_get_list_tramp,
 695                          implements_type, include_abstract, &list);
 696     return list;
 697 }
 698
 699 void object_ref(Object *obj)
 700 {
 701      atomic_inc(&obj->ref);
 702 }
 703
 704 void object_unref(Object *obj)
 705 {
 706     g_assert(obj->ref > 0);
 707
 708     /* parent always holds a reference to its children */
 709     if (atomic_fetch_dec(&obj->ref) == 1) {
 710         object_finalize(obj);
 711     }
 712 }
 713
 714 void object_property_add(Object *obj, const char *name, const char *type,
 715                          ObjectPropertyAccessor *get,
 716                          ObjectPropertyAccessor *set,
 717                          ObjectPropertyRelease *release,
 718                          void *opaque, Error **errp)
 719 {
 720     ObjectProperty *prop;
 721
 722     QTAILQ_FOREACH(prop, &obj->properties, node) {
 723         if (strcmp(prop->name, name) == 0) {
 724             error_setg(errp, "attempt to add duplicate property '%s'"
 725                        " to object (type '%s')", name,
 726                        object_get_typename(obj));
 727             return;
 728         }
 729     }
 730
 731     prop = g_malloc0(sizeof(*prop));
 732
 733     prop->name = g_strdup(name);
 734     prop->type = g_strdup(type);
 735
 736     prop->get = get;
 737     prop->set = set;
 738     prop->release = release;
 739     prop->opaque = opaque;
 740
 741     QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
 742 }
 743
 744 ObjectProperty *object_property_find(Object *obj, const char *name,
 745                                      Error **errp)
 746 {
 747     ObjectProperty *prop;
 748
 749     QTAILQ_FOREACH(prop, &obj->properties, node) {
 750         if (strcmp(prop->name, name) == 0) {
 751             return prop;
 752         }
 753     }
 754
 755     error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
 756     return NULL;
 757 }
 758
 759 void object_property_del(Object *obj, const char *name, Error **errp)
 760 {
 761     ObjectProperty *prop = object_property_find(obj, name, errp);
 762     if (prop == NULL) {
 763         return;
 764     }
 765
 766     if (prop->release) {
 767         prop->release(obj, name, prop->opaque);
 768     }
 769
 770     QTAILQ_REMOVE(&obj->properties, prop, node);
 771
 772     g_free(prop->name);
 773     g_free(prop->type);
 774     g_free(prop);
 775 }
 776
 777 void object_property_get(Object *obj, Visitor *v, const char *name,
 778                          Error **errp)
 779 {
 780     ObjectProperty *prop = object_property_find(obj, name, errp);
 781     if (prop == NULL) {
 782         return;
 783     }
 784
 785     if (!prop->get) {
 786         error_set(errp, QERR_PERMISSION_DENIED);
 787     } else {
 788         prop->get(obj, v, prop->opaque, name, errp);
 789     }
 790 }
 791
 792 void object_property_set(Object *obj, Visitor *v, const char *name,
 793                          Error **errp)
 794 {
 795     ObjectProperty *prop = object_property_find(obj, name, errp);
 796     if (prop == NULL) {
 797         return;
 798     }
 799
 800     if (!prop->set) {
 801         error_set(errp, QERR_PERMISSION_DENIED);
 802     } else {
 803         prop->set(obj, v, prop->opaque, name, errp);
 804     }
 805 }
 806
 807 void object_property_set_str(Object *obj, const char *value,
 808                              const char *name, Error **errp)
 809 {
 810     QString *qstr = qstring_from_str(value);
 811     object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
 812
 813     QDECREF(qstr);
 814 }
 815
 816 char *object_property_get_str(Object *obj, const char *name,
 817                               Error **errp)
 818 {
 819     QObject *ret = object_property_get_qobject(obj, name, errp);
 820     QString *qstring;
 821     char *retval;
 822
 823     if (!ret) {
 824         return NULL;
 825     }
 826     qstring = qobject_to_qstring(ret);
 827     if (!qstring) {
 828         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
 829         retval = NULL;
 830     } else {
 831         retval = g_strdup(qstring_get_str(qstring));
 832     }
 833
 834     QDECREF(qstring);
 835     return retval;
 836 }
 837
 838 void object_property_set_link(Object *obj, Object *value,
 839                               const char *name, Error **errp)
 840 {
 841     gchar *path = object_get_canonical_path(value);
 842     object_property_set_str(obj, path, name, errp);
 843     g_free(path);
 844 }
 845
 846 Object *object_property_get_link(Object *obj, const char *name,
 847                                  Error **errp)
 848 {
 849     char *str = object_property_get_str(obj, name, errp);
 850     Object *target = NULL;
 851
 852     if (str && *str) {
 853         target = object_resolve_path(str, NULL);
 854         if (!target) {
 855             error_set(errp, QERR_DEVICE_NOT_FOUND, str);
 856         }
 857     }
 858
 859     g_free(str);
 860     return target;
 861 }
 862
 863 void object_property_set_bool(Object *obj, bool value,
 864                               const char *name, Error **errp)
 865 {
 866     QBool *qbool = qbool_from_int(value);
 867     object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
 868
 869     QDECREF(qbool);
 870 }
 871
 872 bool object_property_get_bool(Object *obj, const char *name,
 873                               Error **errp)
 874 {
 875     QObject *ret = object_property_get_qobject(obj, name, errp);
 876     QBool *qbool;
 877     bool retval;
 878
 879     if (!ret) {
 880         return false;
 881     }
 882     qbool = qobject_to_qbool(ret);
 883     if (!qbool) {
 884         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
 885         retval = false;
 886     } else {
 887         retval = qbool_get_int(qbool);
 888     }
 889
 890     QDECREF(qbool);
 891     return retval;
 892 }
 893
 894 void object_property_set_int(Object *obj, int64_t value,
 895                              const char *name, Error **errp)
 896 {
 897     QInt *qint = qint_from_int(value);
 898     object_property_set_qobject(obj, QOBJECT(qint), name, errp);
 899
 900     QDECREF(qint);
 901 }
 902
 903 int64_t object_property_get_int(Object *obj, const char *name,
 904                                 Error **errp)
 905 {
 906     QObject *ret = object_property_get_qobject(obj, name, errp);
 907     QInt *qint;
 908     int64_t retval;
 909
 910     if (!ret) {
 911         return -1;
 912     }
 913     qint = qobject_to_qint(ret);
 914     if (!qint) {
 915         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
 916         retval = -1;
 917     } else {
 918         retval = qint_get_int(qint);
 919     }
 920
 921     QDECREF(qint);
 922     return retval;
 923 }
 924
 925 void object_property_parse(Object *obj, const char *string,
 926                            const char *name, Error **errp)
 927 {
 928     StringInputVisitor *mi;
 929     mi = string_input_visitor_new(string);
 930     object_property_set(obj, string_input_get_visitor(mi), name, errp);
 931
 932     string_input_visitor_cleanup(mi);
 933 }
 934
 935 char *object_property_print(Object *obj, const char *name,
 936                             Error **errp)
 937 {
 938     StringOutputVisitor *mo;
 939     char *string;
 940
 941     mo = string_output_visitor_new();
 942     object_property_get(obj, string_output_get_visitor(mo), name, errp);
 943     string = string_output_get_string(mo);
 944     string_output_visitor_cleanup(mo);
 945     return string;
 946 }
 947
 948 const char *object_property_get_type(Object *obj, const char *name, Error **errp)
 949 {
 950     ObjectProperty *prop = object_property_find(obj, name, errp);
 951     if (prop == NULL) {
 952         return NULL;
 953     }
 954
 955     return prop->type;
 956 }
 957
 958 Object *object_get_root(void)
 959 {
 960     static Object *root;
 961
 962     if (!root) {
 963         root = object_new("container");
 964     }
 965
 966     return root;
 967 }
 968
 969 static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
 970                                       const char *name, Error **errp)
 971 {
 972     Object *child = opaque;
 973     gchar *path;
 974
 975     path = object_get_canonical_path(child);
 976     visit_type_str(v, &path, name, errp);
 977     g_free(path);
 978 }
 979
 980 static void object_finalize_child_property(Object *obj, const char *name,
 981                                            void *opaque)
 982 {
 983     Object *child = opaque;
 984
 985     object_unref(child);
 986 }
 987
 988 void object_property_add_child(Object *obj, const char *name,
 989                                Object *child, Error **errp)
 990 {
 991     gchar *type;
 992
 993     type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
 994
 995     object_property_add(obj, name, type, object_get_child_property,
 996                         NULL, object_finalize_child_property, child, errp);
 997
 998     object_ref(child);
 999     g_assert(child->parent == NULL);
1000     child->parent = obj;
1001
1002     g_free(type);
1003 }
1004
1005 static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
1006                                      const char *name, Error **errp)
1007 {
1008     Object **child = opaque;
1009     gchar *path;
1010
1011     if (*child) {
1012         path = object_get_canonical_path(*child);
1013         visit_type_str(v, &path, name, errp);
1014         g_free(path);
1015     } else {
1016         path = (gchar *)"";
1017         visit_type_str(v, &path, name, errp);
1018     }
1019 }
1020
1021 static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
1022                                      const char *name, Error **errp)
1023 {
1024     Object **child = opaque;
1025     Object *old_target;
1026     bool ambiguous = false;
1027     const char *type;
1028     char *path;
1029     gchar *target_type;
1030
1031     type = object_property_get_type(obj, name, NULL);
1032
1033     visit_type_str(v, &path, name, errp);
1034
1035     old_target = *child;
1036     *child = NULL;
1037
1038     if (strcmp(path, "") != 0) {
1039         Object *target;
1040
1041         /* Go from link<FOO> to FOO.  */
1042         target_type = g_strndup(&type[5], strlen(type) - 6);
1043         target = object_resolve_path_type(path, target_type, &ambiguous);
1044
1045         if (ambiguous) {
1046             error_set(errp, QERR_AMBIGUOUS_PATH, path);
1047         } else if (target) {
1048             object_ref(target);
1049             *child = target;
1050         } else {
1051             target = object_resolve_path(path, &ambiguous);
1052             if (target || ambiguous) {
1053                 error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
1054             } else {
1055                 error_set(errp, QERR_DEVICE_NOT_FOUND, path);
1056             }
1057         }
1058         g_free(target_type);
1059     }
1060
1061     g_free(path);
1062
1063     if (old_target != NULL) {
1064         object_unref(old_target);
1065     }
1066 }
1067
1068 void object_property_add_link(Object *obj, const char *name,
1069                               const char *type, Object **child,
1070                               Error **errp)
1071 {
1072     gchar *full_type;
1073
1074     full_type = g_strdup_printf("link<%s>", type);
1075
1076     object_property_add(obj, name, full_type,
1077                         object_get_link_property,
1078                         object_set_link_property,
1079                         NULL, child, errp);
1080
1081     g_free(full_type);
1082 }
1083
1084 gchar *object_get_canonical_path(Object *obj)
1085 {
1086     Object *root = object_get_root();
1087     char *newpath = NULL, *path = NULL;
1088
1089     while (obj != root) {
1090         ObjectProperty *prop = NULL;
1091
1092         g_assert(obj->parent != NULL);
1093
1094         QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
1095             if (!object_property_is_child(prop)) {
1096                 continue;
1097             }
1098
1099             if (prop->opaque == obj) {
1100                 if (path) {
1101                     newpath = g_strdup_printf("%s/%s", prop->name, path);
1102                     g_free(path);
1103                     path = newpath;
1104                 } else {
1105                     path = g_strdup(prop->name);
1106                 }
1107                 break;
1108             }
1109         }
1110
1111         g_assert(prop != NULL);
1112
1113         obj = obj->parent;
1114     }
1115
1116     newpath = g_strdup_printf("/%s", path);
1117     g_free(path);
1118
1119     return newpath;
1120 }
1121
1122 Object *object_resolve_path_component(Object *parent, const gchar *part)
1123 {
1124     ObjectProperty *prop = object_property_find(parent, part, NULL);
1125     if (prop == NULL) {
1126         return NULL;
1127     }
1128
1129     if (object_property_is_link(prop)) {
1130         return *(Object **)prop->opaque;
1131     } else if (object_property_is_child(prop)) {
1132         return prop->opaque;
1133     } else {
1134         return NULL;
1135     }
1136 }
1137
1138 static Object *object_resolve_abs_path(Object *parent,
1139                                           gchar **parts,
1140                                           const char *typename,
1141                                           int index)
1142 {
1143     Object *child;
1144
1145     if (parts[index] == NULL) {
1146         return object_dynamic_cast(parent, typename);
1147     }
1148
1149     if (strcmp(parts[index], "") == 0) {
1150         return object_resolve_abs_path(parent, parts, typename, index + 1);
1151     }
1152
1153     child = object_resolve_path_component(parent, parts[index]);
1154     if (!child) {
1155         return NULL;
1156     }
1157
1158     return object_resolve_abs_path(child, parts, typename, index + 1);
1159 }
1160
1161 static Object *object_resolve_partial_path(Object *parent,
1162                                               gchar **parts,
1163                                               const char *typename,
1164                                               bool *ambiguous)
1165 {
1166     Object *obj;
1167     ObjectProperty *prop;
1168
1169     obj = object_resolve_abs_path(parent, parts, typename, 0);
1170
1171     QTAILQ_FOREACH(prop, &parent->properties, node) {
1172         Object *found;
1173
1174         if (!object_property_is_child(prop)) {
1175             continue;
1176         }
1177
1178         found = object_resolve_partial_path(prop->opaque, parts,
1179                                             typename, ambiguous);
1180         if (found) {
1181             if (obj) {
1182                 if (ambiguous) {
1183                     *ambiguous = true;
1184                 }
1185                 return NULL;
1186             }
1187             obj = found;
1188         }
1189
1190         if (ambiguous && *ambiguous) {
1191             return NULL;
1192         }
1193     }
1194
1195     return obj;
1196 }
1197
1198 Object *object_resolve_path_type(const char *path, const char *typename,
1199                                  bool *ambiguous)
1200 {
1201     Object *obj;
1202     gchar **parts;
1203
1204     parts = g_strsplit(path, "/", 0);
1205     assert(parts);
1206
1207     if (parts[0] == NULL || strcmp(parts[0], "") != 0) {
1208         if (ambiguous) {
1209             *ambiguous = false;
1210         }
1211         obj = object_resolve_partial_path(object_get_root(), parts,
1212                                           typename, ambiguous);
1213     } else {
1214         obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
1215     }
1216
1217     g_strfreev(parts);
1218
1219     return obj;
1220 }
1221
1222 Object *object_resolve_path(const char *path, bool *ambiguous)
1223 {
1224     return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
1225 }
1226
1227 typedef struct StringProperty
1228 {
1229     char *(*get)(Object *, Error **);
1230     void (*set)(Object *, const char *, Error **);
1231 } StringProperty;
1232
1233 static void property_get_str(Object *obj, Visitor *v, void *opaque,
1234                              const char *name, Error **errp)
1235 {
1236     StringProperty *prop = opaque;
1237     char *value;
1238
1239     value = prop->get(obj, errp);
1240     if (value) {
1241         visit_type_str(v, &value, name, errp);
1242         g_free(value);
1243     }
1244 }
1245
1246 static void property_set_str(Object *obj, Visitor *v, void *opaque,
1247                              const char *name, Error **errp)
1248 {
1249     StringProperty *prop = opaque;
1250     char *value;
1251     Error *local_err = NULL;
1252
1253     visit_type_str(v, &value, name, &local_err);
1254     if (local_err) {
1255         error_propagate(errp, local_err);
1256         return;
1257     }
1258
1259     prop->set(obj, value, errp);
1260     g_free(value);
1261 }
1262
1263 static void property_release_str(Object *obj, const char *name,
1264                                  void *opaque)
1265 {
1266     StringProperty *prop = opaque;
1267     g_free(prop);
1268 }
1269
1270 void object_property_add_str(Object *obj, const char *name,
1271                            char *(*get)(Object *, Error **),
1272                            void (*set)(Object *, const char *, Error **),
1273                            Error **errp)
1274 {
1275     StringProperty *prop = g_malloc0(sizeof(*prop));
1276
1277     prop->get = get;
1278     prop->set = set;
1279
1280     object_property_add(obj, name, "string",
1281                         get ? property_get_str : NULL,
1282                         set ? property_set_str : NULL,
1283                         property_release_str,
1284                         prop, errp);
1285 }
1286
1287 typedef struct BoolProperty
1288 {
1289     bool (*get)(Object *, Error **);
1290     void (*set)(Object *, bool, Error **);
1291 } BoolProperty;
1292
1293 static void property_get_bool(Object *obj, Visitor *v, void *opaque,
1294                               const char *name, Error **errp)
1295 {
1296     BoolProperty *prop = opaque;
1297     bool value;
1298
1299     value = prop->get(obj, errp);
1300     visit_type_bool(v, &value, name, errp);
1301 }
1302
1303 static void property_set_bool(Object *obj, Visitor *v, void *opaque,
1304                               const char *name, Error **errp)
1305 {
1306     BoolProperty *prop = opaque;
1307     bool value;
1308     Error *local_err = NULL;
1309
1310     visit_type_bool(v, &value, name, &local_err);
1311     if (local_err) {
1312         error_propagate(errp, local_err);
1313         return;
1314     }
1315
1316     prop->set(obj, value, errp);
1317 }
1318
1319 static void property_release_bool(Object *obj, const char *name,
1320                                   void *opaque)
1321 {
1322     BoolProperty *prop = opaque;
1323     g_free(prop);
1324 }
1325
1326 void object_property_add_bool(Object *obj, const char *name,
1327                               bool (*get)(Object *, Error **),
1328                               void (*set)(Object *, bool, Error **),
1329                               Error **errp)
1330 {
1331     BoolProperty *prop = g_malloc0(sizeof(*prop));
1332
1333     prop->get = get;
1334     prop->set = set;
1335
1336     object_property_add(obj, name, "bool",
1337                         get ? property_get_bool : NULL,
1338                         set ? property_set_bool : NULL,
1339                         property_release_bool,
1340                         prop, errp);
1341 }
1342
1343 static char *qdev_get_type(Object *obj, Error **errp)
1344 {
1345     return g_strdup(object_get_typename(obj));
1346 }
1347
1348 static void property_get_uint8_ptr(Object *obj, Visitor *v,
1349                                    void *opaque, const char *name,
1350                                    Error **errp)
1351 {
1352     uint8_t value = *(uint8_t *)opaque;
1353     visit_type_uint8(v, &value, name, errp);
1354 }
1355
1356 static void property_get_uint16_ptr(Object *obj, Visitor *v,
1357                                    void *opaque, const char *name,
1358                                    Error **errp)
1359 {
1360     uint16_t value = *(uint16_t *)opaque;
1361     visit_type_uint16(v, &value, name, errp);
1362 }
1363
1364 static void property_get_uint32_ptr(Object *obj, Visitor *v,
1365                                    void *opaque, const char *name,
1366                                    Error **errp)
1367 {
1368     uint32_t value = *(uint32_t *)opaque;
1369     visit_type_uint32(v, &value, name, errp);
1370 }
1371
1372 static void property_get_uint64_ptr(Object *obj, Visitor *v,
1373                                    void *opaque, const char *name,
1374                                    Error **errp)
1375 {
1376     uint64_t value = *(uint64_t *)opaque;
1377     visit_type_uint64(v, &value, name, errp);
1378 }
1379
1380 void object_property_add_uint8_ptr(Object *obj, const char *name,
1381                                    const uint8_t *v, Error **errp)
1382 {
1383     object_property_add(obj, name, "uint8", property_get_uint8_ptr,
1384                         NULL, NULL, (void *)v, errp);
1385 }
1386
1387 void object_property_add_uint16_ptr(Object *obj, const char *name,
1388                                     const uint16_t *v, Error **errp)
1389 {
1390     object_property_add(obj, name, "uint16", property_get_uint16_ptr,
1391                         NULL, NULL, (void *)v, errp);
1392 }
1393
1394 void object_property_add_uint32_ptr(Object *obj, const char *name,
1395                                     const uint32_t *v, Error **errp)
1396 {
1397     object_property_add(obj, name, "uint32", property_get_uint32_ptr,
1398                         NULL, NULL, (void *)v, errp);
1399 }
1400
1401 void object_property_add_uint64_ptr(Object *obj, const char *name,
1402                                     const uint64_t *v, Error **errp)
1403 {
1404     object_property_add(obj, name, "uint64", property_get_uint64_ptr,
1405                         NULL, NULL, (void *)v, errp);
1406 }
1407
1408 static void object_instance_init(Object *obj)
1409 {
1410     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
1411 }
1412
1413 static void register_types(void)
1414 {
1415     static TypeInfo interface_info = {
1416         .name = TYPE_INTERFACE,
1417         .class_size = sizeof(InterfaceClass),
1418         .abstract = true,
1419     };
1420
1421     static TypeInfo object_info = {
1422         .name = TYPE_OBJECT,
1423         .instance_size = sizeof(Object),
1424         .instance_init = object_instance_init,
1425         .abstract = true,
1426     };
1427
1428     type_interface = type_register_internal(&interface_info);
1429     type_register_internal(&object_info);
1430 }
1431
1432 type_init(register_types)