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