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