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