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         obj->parent = NULL;
 406     }
 407     object_unref(obj);
 408 }
 409
 410 static void object_deinit(Object *obj, TypeImpl *type)
 411 {
 412     if (type->instance_finalize) {
 413         type->instance_finalize(obj);
 414     }
 415
 416     if (type_has_parent(type)) {
 417         object_deinit(obj, type_get_parent(type));
 418     }
 419 }
 420
 421 static void object_finalize(void *data)
 422 {
 423     Object *obj = data;
 424     TypeImpl *ti = obj->class->type;
 425
 426     object_deinit(obj, ti);
 427     object_property_del_all(obj);
 428
 429     g_assert(obj->ref == 0);
 430     if (obj->free) {
 431         obj->free(obj);
 432     }
 433 }
 434
 435 Object *object_new_with_type(Type type)
 436 {
 437     Object *obj;
 438
 439     g_assert(type != NULL);
 440     type_initialize(type);
 441
 442     obj = g_malloc(type->instance_size);
 443     object_initialize_with_type(obj, type->instance_size, type);
 444     obj->free = g_free;
 445
 446     return obj;
 447 }
 448
 449 Object *object_new(const char *typename)
 450 {
 451     TypeImpl *ti = type_get_by_name(typename);
 452
 453     return object_new_with_type(ti);
 454 }
 455
 456 Object *object_dynamic_cast(Object *obj, const char *typename)
 457 {
 458     if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) {
 459         return obj;
 460     }
 461
 462     return NULL;
 463 }
 464
 465 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
 466                                    const char *file, int line, const char *func)
 467 {
 468     trace_object_dynamic_cast_assert(obj ? obj->class->type->name : "(null)",
 469                                      typename, file, line, func);
 470
 471 #ifdef CONFIG_QOM_CAST_DEBUG
 472     int i;
 473     Object *inst;
 474
 475     for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
 476         if (obj->class->object_cast_cache[i] == typename) {
 477             goto out;
 478         }
 479     }
 480
 481     inst = object_dynamic_cast(obj, typename);
 482
 483     if (!inst && obj) {
 484         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 485                 file, line, func, obj, typename);
 486         abort();
 487     }
 488
 489     assert(obj == inst);
 490
 491     if (obj && obj == inst) {
 492         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 493             obj->class->object_cast_cache[i - 1] =
 494                     obj->class->object_cast_cache[i];
 495         }
 496         obj->class->object_cast_cache[i - 1] = typename;
 497     }
 498
 499 out:
 500 #endif
 501     return obj;
 502 }
 503
 504 ObjectClass *object_class_dynamic_cast(ObjectClass *class,
 505                                        const char *typename)
 506 {
 507     ObjectClass *ret = NULL;
 508     TypeImpl *target_type;
 509     TypeImpl *type;
 510
 511     if (!class) {
 512         return NULL;
 513     }
 514
 515     /* A simple fast path that can trigger a lot for leaf classes.  */
 516     type = class->type;
 517     if (type->name == typename) {
 518         return class;
 519     }
 520
 521     target_type = type_get_by_name(typename);
 522     if (!target_type) {
 523         /* target class type unknown, so fail the cast */
 524         return NULL;
 525     }
 526
 527     if (type->class->interfaces &&
 528             type_is_ancestor(target_type, type_interface)) {
 529         int found = 0;
 530         GSList *i;
 531
 532         for (i = class->interfaces; i; i = i->next) {
 533             ObjectClass *target_class = i->data;
 534
 535             if (type_is_ancestor(target_class->type, target_type)) {
 536                 ret = target_class;
 537                 found++;
 538             }
 539          }
 540
 541         /* The match was ambiguous, don't allow a cast */
 542         if (found > 1) {
 543             ret = NULL;
 544         }
 545     } else if (type_is_ancestor(type, target_type)) {
 546         ret = class;
 547     }
 548
 549     return ret;
 550 }
 551
 552 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
 553                                               const char *typename,
 554                                               const char *file, int line,
 555                                               const char *func)
 556 {
 557     ObjectClass *ret;
 558
 559     trace_object_class_dynamic_cast_assert(class ? class->type->name : "(null)",
 560                                            typename, file, line, func);
 561
 562 #ifdef CONFIG_QOM_CAST_DEBUG
 563     int i;
 564
 565     for (i = 0; class && i < OBJECT_CLASS_CAST_CACHE; i++) {
 566         if (class->class_cast_cache[i] == typename) {
 567             ret = class;
 568             goto out;
 569         }
 570     }
 571 #else
 572     if (!class || !class->interfaces) {
 573         return class;
 574     }
 575 #endif
 576
 577     ret = object_class_dynamic_cast(class, typename);
 578     if (!ret && class) {
 579         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 580                 file, line, func, class, typename);
 581         abort();
 582     }
 583
 584 #ifdef CONFIG_QOM_CAST_DEBUG
 585     if (class && ret == class) {
 586         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 587             class->class_cast_cache[i - 1] = class->class_cast_cache[i];
 588         }
 589         class->class_cast_cache[i - 1] = typename;
 590     }
 591 out:
 592 #endif
 593     return ret;
 594 }
 595
 596 const char *object_get_typename(Object *obj)
 597 {
 598     return obj->class->type->name;
 599 }
 600
 601 ObjectClass *object_get_class(Object *obj)
 602 {
 603     return obj->class;
 604 }
 605
 606 bool object_class_is_abstract(ObjectClass *klass)
 607 {
 608     return klass->type->abstract;
 609 }
 610
 611 const char *object_class_get_name(ObjectClass *klass)
 612 {
 613     return klass->type->name;
 614 }
 615
 616 ObjectClass *object_class_by_name(const char *typename)
 617 {
 618     TypeImpl *type = type_get_by_name(typename);
 619
 620     if (!type) {
 621         return NULL;
 622     }
 623
 624     type_initialize(type);
 625
 626     return type->class;
 627 }
 628
 629 ObjectClass *object_class_get_parent(ObjectClass *class)
 630 {
 631     TypeImpl *type = type_get_parent(class->type);
 632
 633     if (!type) {
 634         return NULL;
 635     }
 636
 637     type_initialize(type);
 638
 639     return type->class;
 640 }
 641
 642 typedef struct OCFData
 643 {
 644     void (*fn)(ObjectClass *klass, void *opaque);
 645     const char *implements_type;
 646     bool include_abstract;
 647     void *opaque;
 648 } OCFData;
 649
 650 static void object_class_foreach_tramp(gpointer key, gpointer value,
 651                                        gpointer opaque)
 652 {
 653     OCFData *data = opaque;
 654     TypeImpl *type = value;
 655     ObjectClass *k;
 656
 657     type_initialize(type);
 658     k = type->class;
 659
 660     if (!data->include_abstract && type->abstract) {
 661         return;
 662     }
 663
 664     if (data->implements_type &&
 665         !object_class_dynamic_cast(k, data->implements_type)) {
 666         return;
 667     }
 668
 669     data->fn(k, data->opaque);
 670 }
 671
 672 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 673                           const char *implements_type, bool include_abstract,
 674                           void *opaque)
 675 {
 676     OCFData data = { fn, implements_type, include_abstract, opaque };
 677
 678     enumerating_types = true;
 679     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 680     enumerating_types = false;
 681 }
 682
 683 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
 684                          void *opaque)
 685 {
 686     ObjectProperty *prop;
 687     int ret = 0;
 688
 689     QTAILQ_FOREACH(prop, &obj->properties, node) {
 690         if (object_property_is_child(prop)) {
 691             ret = fn(prop->opaque, opaque);
 692             if (ret != 0) {
 693                 break;
 694             }
 695         }
 696     }
 697     return ret;
 698 }
 699
 700 static void object_class_get_list_tramp(ObjectClass *klass, void *opaque)
 701 {
 702     GSList **list = opaque;
 703
 704     *list = g_slist_prepend(*list, klass);
 705 }
 706
 707 GSList *object_class_get_list(const char *implements_type,
 708                               bool include_abstract)
 709 {
 710     GSList *list = NULL;
 711
 712     object_class_foreach(object_class_get_list_tramp,
 713                          implements_type, include_abstract, &list);
 714     return list;
 715 }
 716
 717 void object_ref(Object *obj)
 718 {
 719      atomic_inc(&obj->ref);
 720 }
 721
 722 void object_unref(Object *obj)
 723 {
 724     g_assert(obj->ref > 0);
 725
 726     /* parent always holds a reference to its children */
 727     if (atomic_fetch_dec(&obj->ref) == 1) {
 728         object_finalize(obj);
 729     }
 730 }
 731
 732 void object_property_add(Object *obj, const char *name, const char *type,
 733                          ObjectPropertyAccessor *get,
 734                          ObjectPropertyAccessor *set,
 735                          ObjectPropertyRelease *release,
 736                          void *opaque, Error **errp)
 737 {
 738     ObjectProperty *prop;
 739
 740     QTAILQ_FOREACH(prop, &obj->properties, node) {
 741         if (strcmp(prop->name, name) == 0) {
 742             error_setg(errp, "attempt to add duplicate property '%s'"
 743                        " to object (type '%s')", name,
 744                        object_get_typename(obj));
 745             return;
 746         }
 747     }
 748
 749     prop = g_malloc0(sizeof(*prop));
 750
 751     prop->name = g_strdup(name);
 752     prop->type = g_strdup(type);
 753
 754     prop->get = get;
 755     prop->set = set;
 756     prop->release = release;
 757     prop->opaque = opaque;
 758
 759     QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
 760 }
 761
 762 ObjectProperty *object_property_find(Object *obj, const char *name,
 763                                      Error **errp)
 764 {
 765     ObjectProperty *prop;
 766
 767     QTAILQ_FOREACH(prop, &obj->properties, node) {
 768         if (strcmp(prop->name, name) == 0) {
 769             return prop;
 770         }
 771     }
 772
 773     error_setg(errp, "Property '.%s' not found", name);
 774     return NULL;
 775 }
 776
 777 void object_property_del(Object *obj, const char *name, Error **errp)
 778 {
 779     ObjectProperty *prop = object_property_find(obj, name, errp);
 780     if (prop == NULL) {
 781         return;
 782     }
 783
 784     if (prop->release) {
 785         prop->release(obj, name, prop->opaque);
 786     }
 787
 788     QTAILQ_REMOVE(&obj->properties, prop, node);
 789
 790     g_free(prop->name);
 791     g_free(prop->type);
 792     g_free(prop);
 793 }
 794
 795 void object_property_get(Object *obj, Visitor *v, const char *name,
 796                          Error **errp)
 797 {
 798     ObjectProperty *prop = object_property_find(obj, name, errp);
 799     if (prop == NULL) {
 800         return;
 801     }
 802
 803     if (!prop->get) {
 804         error_set(errp, QERR_PERMISSION_DENIED);
 805     } else {
 806         prop->get(obj, v, prop->opaque, name, errp);
 807     }
 808 }
 809
 810 void object_property_set(Object *obj, Visitor *v, const char *name,
 811                          Error **errp)
 812 {
 813     ObjectProperty *prop = object_property_find(obj, name, errp);
 814     if (prop == NULL) {
 815         return;
 816     }
 817
 818     if (!prop->set) {
 819         error_set(errp, QERR_PERMISSION_DENIED);
 820     } else {
 821         prop->set(obj, v, prop->opaque, name, errp);
 822     }
 823 }
 824
 825 void object_property_set_str(Object *obj, const char *value,
 826                              const char *name, Error **errp)
 827 {
 828     QString *qstr = qstring_from_str(value);
 829     object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
 830
 831     QDECREF(qstr);
 832 }
 833
 834 char *object_property_get_str(Object *obj, const char *name,
 835                               Error **errp)
 836 {
 837     QObject *ret = object_property_get_qobject(obj, name, errp);
 838     QString *qstring;
 839     char *retval;
 840
 841     if (!ret) {
 842         return NULL;
 843     }
 844     qstring = qobject_to_qstring(ret);
 845     if (!qstring) {
 846         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
 847         retval = NULL;
 848     } else {
 849         retval = g_strdup(qstring_get_str(qstring));
 850     }
 851
 852     QDECREF(qstring);
 853     return retval;
 854 }
 855
 856 void object_property_set_link(Object *obj, Object *value,
 857                               const char *name, Error **errp)
 858 {
 859     gchar *path = object_get_canonical_path(value);
 860     object_property_set_str(obj, path, name, errp);
 861     g_free(path);
 862 }
 863
 864 Object *object_property_get_link(Object *obj, const char *name,
 865                                  Error **errp)
 866 {
 867     char *str = object_property_get_str(obj, name, errp);
 868     Object *target = NULL;
 869
 870     if (str && *str) {
 871         target = object_resolve_path(str, NULL);
 872         if (!target) {
 873             error_set(errp, QERR_DEVICE_NOT_FOUND, str);
 874         }
 875     }
 876
 877     g_free(str);
 878     return target;
 879 }
 880
 881 void object_property_set_bool(Object *obj, bool value,
 882                               const char *name, Error **errp)
 883 {
 884     QBool *qbool = qbool_from_int(value);
 885     object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
 886
 887     QDECREF(qbool);
 888 }
 889
 890 bool object_property_get_bool(Object *obj, const char *name,
 891                               Error **errp)
 892 {
 893     QObject *ret = object_property_get_qobject(obj, name, errp);
 894     QBool *qbool;
 895     bool retval;
 896
 897     if (!ret) {
 898         return false;
 899     }
 900     qbool = qobject_to_qbool(ret);
 901     if (!qbool) {
 902         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
 903         retval = false;
 904     } else {
 905         retval = qbool_get_int(qbool);
 906     }
 907
 908     QDECREF(qbool);
 909     return retval;
 910 }
 911
 912 void object_property_set_int(Object *obj, int64_t value,
 913                              const char *name, Error **errp)
 914 {
 915     QInt *qint = qint_from_int(value);
 916     object_property_set_qobject(obj, QOBJECT(qint), name, errp);
 917
 918     QDECREF(qint);
 919 }
 920
 921 int64_t object_property_get_int(Object *obj, const char *name,
 922                                 Error **errp)
 923 {
 924     QObject *ret = object_property_get_qobject(obj, name, errp);
 925     QInt *qint;
 926     int64_t retval;
 927
 928     if (!ret) {
 929         return -1;
 930     }
 931     qint = qobject_to_qint(ret);
 932     if (!qint) {
 933         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
 934         retval = -1;
 935     } else {
 936         retval = qint_get_int(qint);
 937     }
 938
 939     QDECREF(qint);
 940     return retval;
 941 }
 942
 943 int object_property_get_enum(Object *obj, const char *name,
 944                              const char *strings[], Error **errp)
 945 {
 946     StringOutputVisitor *sov;
 947     StringInputVisitor *siv;
 948     int ret;
 949
 950     sov = string_output_visitor_new(false);
 951     object_property_get(obj, string_output_get_visitor(sov), name, errp);
 952     siv = string_input_visitor_new(string_output_get_string(sov));
 953     string_output_visitor_cleanup(sov);
 954     visit_type_enum(string_input_get_visitor(siv),
 955                     &ret, strings, NULL, name, errp);
 956     string_input_visitor_cleanup(siv);
 957
 958     return ret;
 959 }
 960
 961 void object_property_get_uint16List(Object *obj, const char *name,
 962                                     uint16List **list, Error **errp)
 963 {
 964     StringOutputVisitor *ov;
 965     StringInputVisitor *iv;
 966
 967     ov = string_output_visitor_new(false);
 968     object_property_get(obj, string_output_get_visitor(ov),
 969                         name, errp);
 970     iv = string_input_visitor_new(string_output_get_string(ov));
 971     visit_type_uint16List(string_input_get_visitor(iv),
 972                           list, NULL, errp);
 973     string_output_visitor_cleanup(ov);
 974     string_input_visitor_cleanup(iv);
 975 }
 976
 977 void object_property_parse(Object *obj, const char *string,
 978                            const char *name, Error **errp)
 979 {
 980     StringInputVisitor *mi;
 981     mi = string_input_visitor_new(string);
 982     object_property_set(obj, string_input_get_visitor(mi), name, errp);
 983
 984     string_input_visitor_cleanup(mi);
 985 }
 986
 987 char *object_property_print(Object *obj, const char *name, bool human,
 988                             Error **errp)
 989 {
 990     StringOutputVisitor *mo;
 991     char *string;
 992
 993     mo = string_output_visitor_new(human);
 994     object_property_get(obj, string_output_get_visitor(mo), name, errp);
 995     string = string_output_get_string(mo);
 996     string_output_visitor_cleanup(mo);
 997     return string;
 998 }
 999
1000 const char *object_property_get_type(Object *obj, const char *name, Error **errp)
1001 {
1002     ObjectProperty *prop = object_property_find(obj, name, errp);
1003     if (prop == NULL) {
1004         return NULL;
1005     }
1006
1007     return prop->type;
1008 }
1009
1010 Object *object_get_root(void)
1011 {
1012     static Object *root;
1013
1014     if (!root) {
1015         root = object_new("container");
1016     }
1017
1018     return root;
1019 }
1020
1021 static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
1022                                       const char *name, Error **errp)
1023 {
1024     Object *child = opaque;
1025     gchar *path;
1026
1027     path = object_get_canonical_path(child);
1028     visit_type_str(v, &path, name, errp);
1029     g_free(path);
1030 }
1031
1032 static void object_finalize_child_property(Object *obj, const char *name,
1033                                            void *opaque)
1034 {
1035     Object *child = opaque;
1036
1037     object_unref(child);
1038 }
1039
1040 void object_property_add_child(Object *obj, const char *name,
1041                                Object *child, Error **errp)
1042 {
1043     Error *local_err = NULL;
1044     gchar *type;
1045
1046     type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
1047
1048     object_property_add(obj, name, type, object_get_child_property, NULL,
1049                         object_finalize_child_property, child, &local_err);
1050     if (local_err) {
1051         error_propagate(errp, local_err);
1052         goto out;
1053     }
1054     object_ref(child);
1055     g_assert(child->parent == NULL);
1056     child->parent = obj;
1057
1058 out:
1059     g_free(type);
1060 }
1061
1062 void object_property_allow_set_link(Object *obj, const char *name,
1063                                     Object *val, Error **errp)
1064 {
1065     /* Allow the link to be set, always */
1066 }
1067
1068 typedef struct {
1069     Object **child;
1070     void (*check)(Object *, const char *, Object *, Error **);
1071     ObjectPropertyLinkFlags flags;
1072 } LinkProperty;
1073
1074 static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
1075                                      const char *name, Error **errp)
1076 {
1077     LinkProperty *lprop = opaque;
1078     Object **child = lprop->child;
1079     gchar *path;
1080
1081     if (*child) {
1082         path = object_get_canonical_path(*child);
1083         visit_type_str(v, &path, name, errp);
1084         g_free(path);
1085     } else {
1086         path = (gchar *)"";
1087         visit_type_str(v, &path, name, errp);
1088     }
1089 }
1090
1091 /*
1092  * object_resolve_link:
1093  *
1094  * Lookup an object and ensure its type matches the link property type.  This
1095  * is similar to object_resolve_path() except type verification against the
1096  * link property is performed.
1097  *
1098  * Returns: The matched object or NULL on path lookup failures.
1099  */
1100 static Object *object_resolve_link(Object *obj, const char *name,
1101                                    const char *path, Error **errp)
1102 {
1103     const char *type;
1104     gchar *target_type;
1105     bool ambiguous = false;
1106     Object *target;
1107
1108     /* Go from link<FOO> to FOO.  */
1109     type = object_property_get_type(obj, name, NULL);
1110     target_type = g_strndup(&type[5], strlen(type) - 6);
1111     target = object_resolve_path_type(path, target_type, &ambiguous);
1112
1113     if (ambiguous) {
1114         error_set(errp, ERROR_CLASS_GENERIC_ERROR,
1115                   "Path '%s' does not uniquely identify an object", path);
1116     } else if (!target) {
1117         target = object_resolve_path(path, &ambiguous);
1118         if (target || ambiguous) {
1119             error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
1120         } else {
1121             error_set(errp, QERR_DEVICE_NOT_FOUND, path);
1122         }
1123         target = NULL;
1124     }
1125     g_free(target_type);
1126
1127     return target;
1128 }
1129
1130 static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
1131                                      const char *name, Error **errp)
1132 {
1133     Error *local_err = NULL;
1134     LinkProperty *prop = opaque;
1135     Object **child = prop->child;
1136     Object *old_target = *child;
1137     Object *new_target = NULL;
1138     char *path = NULL;
1139
1140     visit_type_str(v, &path, name, &local_err);
1141
1142     if (!local_err && strcmp(path, "") != 0) {
1143         new_target = object_resolve_link(obj, name, path, &local_err);
1144     }
1145
1146     g_free(path);
1147     if (local_err) {
1148         error_propagate(errp, local_err);
1149         return;
1150     }
1151
1152     prop->check(obj, name, new_target, &local_err);
1153     if (local_err) {
1154         error_propagate(errp, local_err);
1155         return;
1156     }
1157
1158     if (new_target) {
1159         object_ref(new_target);
1160     }
1161     *child = new_target;
1162     if (old_target != NULL) {
1163         object_unref(old_target);
1164     }
1165 }
1166
1167 static void object_release_link_property(Object *obj, const char *name,
1168                                          void *opaque)
1169 {
1170     LinkProperty *prop = opaque;
1171
1172     if ((prop->flags & OBJ_PROP_LINK_UNREF_ON_RELEASE) && *prop->child) {
1173         object_unref(*prop->child);
1174     }
1175     g_free(prop);
1176 }
1177
1178 void object_property_add_link(Object *obj, const char *name,
1179                               const char *type, Object **child,
1180                               void (*check)(Object *, const char *,
1181                                             Object *, Error **),
1182                               ObjectPropertyLinkFlags flags,
1183                               Error **errp)
1184 {
1185     Error *local_err = NULL;
1186     LinkProperty *prop = g_malloc(sizeof(*prop));
1187     gchar *full_type;
1188
1189     prop->child = child;
1190     prop->check = check;
1191     prop->flags = flags;
1192
1193     full_type = g_strdup_printf("link<%s>", type);
1194
1195     object_property_add(obj, name, full_type,
1196                         object_get_link_property,
1197                         check ? object_set_link_property : NULL,
1198                         object_release_link_property,
1199                         prop,
1200                         &local_err);
1201     if (local_err) {
1202         error_propagate(errp, local_err);
1203         g_free(prop);
1204     }
1205
1206     g_free(full_type);
1207 }
1208
1209 gchar *object_get_canonical_path_component(Object *obj)
1210 {
1211     ObjectProperty *prop = NULL;
1212
1213     g_assert(obj);
1214     g_assert(obj->parent != NULL);
1215
1216     QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
1217         if (!object_property_is_child(prop)) {
1218             continue;
1219         }
1220
1221         if (prop->opaque == obj) {
1222             return g_strdup(prop->name);
1223         }
1224     }
1225
1226     /* obj had a parent but was not a child, should never happen */
1227     g_assert_not_reached();
1228     return NULL;
1229 }
1230
1231 gchar *object_get_canonical_path(Object *obj)
1232 {
1233     Object *root = object_get_root();
1234     char *newpath, *path = NULL;
1235
1236     while (obj != root) {
1237         char *component = object_get_canonical_path_component(obj);
1238
1239         if (path) {
1240             newpath = g_strdup_printf("%s/%s", component, path);
1241             g_free(component);
1242             g_free(path);
1243             path = newpath;
1244         } else {
1245             path = component;
1246         }
1247
1248         obj = obj->parent;
1249     }
1250
1251     newpath = g_strdup_printf("/%s", path ? path : "");
1252     g_free(path);
1253
1254     return newpath;
1255 }
1256
1257 Object *object_resolve_path_component(Object *parent, const gchar *part)
1258 {
1259     ObjectProperty *prop = object_property_find(parent, part, NULL);
1260     if (prop == NULL) {
1261         return NULL;
1262     }
1263
1264     if (object_property_is_link(prop)) {
1265         LinkProperty *lprop = prop->opaque;
1266         return *lprop->child;
1267     } else if (object_property_is_child(prop)) {
1268         return prop->opaque;
1269     } else {
1270         return NULL;
1271     }
1272 }
1273
1274 static Object *object_resolve_abs_path(Object *parent,
1275                                           gchar **parts,
1276                                           const char *typename,
1277                                           int index)
1278 {
1279     Object *child;
1280
1281     if (parts[index] == NULL) {
1282         return object_dynamic_cast(parent, typename);
1283     }
1284
1285     if (strcmp(parts[index], "") == 0) {
1286         return object_resolve_abs_path(parent, parts, typename, index + 1);
1287     }
1288
1289     child = object_resolve_path_component(parent, parts[index]);
1290     if (!child) {
1291         return NULL;
1292     }
1293
1294     return object_resolve_abs_path(child, parts, typename, index + 1);
1295 }
1296
1297 static Object *object_resolve_partial_path(Object *parent,
1298                                               gchar **parts,
1299                                               const char *typename,
1300                                               bool *ambiguous)
1301 {
1302     Object *obj;
1303     ObjectProperty *prop;
1304
1305     obj = object_resolve_abs_path(parent, parts, typename, 0);
1306
1307     QTAILQ_FOREACH(prop, &parent->properties, node) {
1308         Object *found;
1309
1310         if (!object_property_is_child(prop)) {
1311             continue;
1312         }
1313
1314         found = object_resolve_partial_path(prop->opaque, parts,
1315                                             typename, ambiguous);
1316         if (found) {
1317             if (obj) {
1318                 if (ambiguous) {
1319                     *ambiguous = true;
1320                 }
1321                 return NULL;
1322             }
1323             obj = found;
1324         }
1325
1326         if (ambiguous && *ambiguous) {
1327             return NULL;
1328         }
1329     }
1330
1331     return obj;
1332 }
1333
1334 Object *object_resolve_path_type(const char *path, const char *typename,
1335                                  bool *ambiguous)
1336 {
1337     Object *obj;
1338     gchar **parts;
1339
1340     parts = g_strsplit(path, "/", 0);
1341     assert(parts);
1342
1343     if (parts[0] == NULL || strcmp(parts[0], "") != 0) {
1344         if (ambiguous) {
1345             *ambiguous = false;
1346         }
1347         obj = object_resolve_partial_path(object_get_root(), parts,
1348                                           typename, ambiguous);
1349     } else {
1350         obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
1351     }
1352
1353     g_strfreev(parts);
1354
1355     return obj;
1356 }
1357
1358 Object *object_resolve_path(const char *path, bool *ambiguous)
1359 {
1360     return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
1361 }
1362
1363 typedef struct StringProperty
1364 {
1365     char *(*get)(Object *, Error **);
1366     void (*set)(Object *, const char *, Error **);
1367 } StringProperty;
1368
1369 static void property_get_str(Object *obj, Visitor *v, void *opaque,
1370                              const char *name, Error **errp)
1371 {
1372     StringProperty *prop = opaque;
1373     char *value;
1374
1375     value = prop->get(obj, errp);
1376     if (value) {
1377         visit_type_str(v, &value, name, errp);
1378         g_free(value);
1379     }
1380 }
1381
1382 static void property_set_str(Object *obj, Visitor *v, void *opaque,
1383                              const char *name, Error **errp)
1384 {
1385     StringProperty *prop = opaque;
1386     char *value;
1387     Error *local_err = NULL;
1388
1389     visit_type_str(v, &value, name, &local_err);
1390     if (local_err) {
1391         error_propagate(errp, local_err);
1392         return;
1393     }
1394
1395     prop->set(obj, value, errp);
1396     g_free(value);
1397 }
1398
1399 static void property_release_str(Object *obj, const char *name,
1400                                  void *opaque)
1401 {
1402     StringProperty *prop = opaque;
1403     g_free(prop);
1404 }
1405
1406 void object_property_add_str(Object *obj, const char *name,
1407                            char *(*get)(Object *, Error **),
1408                            void (*set)(Object *, const char *, Error **),
1409                            Error **errp)
1410 {
1411     Error *local_err = NULL;
1412     StringProperty *prop = g_malloc0(sizeof(*prop));
1413
1414     prop->get = get;
1415     prop->set = set;
1416
1417     object_property_add(obj, name, "string",
1418                         get ? property_get_str : NULL,
1419                         set ? property_set_str : NULL,
1420                         property_release_str,
1421                         prop, &local_err);
1422     if (local_err) {
1423         error_propagate(errp, local_err);
1424         g_free(prop);
1425     }
1426 }
1427
1428 typedef struct BoolProperty
1429 {
1430     bool (*get)(Object *, Error **);
1431     void (*set)(Object *, bool, Error **);
1432 } BoolProperty;
1433
1434 static void property_get_bool(Object *obj, Visitor *v, void *opaque,
1435                               const char *name, Error **errp)
1436 {
1437     BoolProperty *prop = opaque;
1438     bool value;
1439
1440     value = prop->get(obj, errp);
1441     visit_type_bool(v, &value, name, errp);
1442 }
1443
1444 static void property_set_bool(Object *obj, Visitor *v, void *opaque,
1445                               const char *name, Error **errp)
1446 {
1447     BoolProperty *prop = opaque;
1448     bool value;
1449     Error *local_err = NULL;
1450
1451     visit_type_bool(v, &value, name, &local_err);
1452     if (local_err) {
1453         error_propagate(errp, local_err);
1454         return;
1455     }
1456
1457     prop->set(obj, value, errp);
1458 }
1459
1460 static void property_release_bool(Object *obj, const char *name,
1461                                   void *opaque)
1462 {
1463     BoolProperty *prop = opaque;
1464     g_free(prop);
1465 }
1466
1467 void object_property_add_bool(Object *obj, const char *name,
1468                               bool (*get)(Object *, Error **),
1469                               void (*set)(Object *, bool, Error **),
1470                               Error **errp)
1471 {
1472     Error *local_err = NULL;
1473     BoolProperty *prop = g_malloc0(sizeof(*prop));
1474
1475     prop->get = get;
1476     prop->set = set;
1477
1478     object_property_add(obj, name, "bool",
1479                         get ? property_get_bool : NULL,
1480                         set ? property_set_bool : NULL,
1481                         property_release_bool,
1482                         prop, &local_err);
1483     if (local_err) {
1484         error_propagate(errp, local_err);
1485         g_free(prop);
1486     }
1487 }
1488
1489 static char *qdev_get_type(Object *obj, Error **errp)
1490 {
1491     return g_strdup(object_get_typename(obj));
1492 }
1493
1494 static void property_get_uint8_ptr(Object *obj, Visitor *v,
1495                                    void *opaque, const char *name,
1496                                    Error **errp)
1497 {
1498     uint8_t value = *(uint8_t *)opaque;
1499     visit_type_uint8(v, &value, name, errp);
1500 }
1501
1502 static void property_get_uint16_ptr(Object *obj, Visitor *v,
1503                                    void *opaque, const char *name,
1504                                    Error **errp)
1505 {
1506     uint16_t value = *(uint16_t *)opaque;
1507     visit_type_uint16(v, &value, name, errp);
1508 }
1509
1510 static void property_get_uint32_ptr(Object *obj, Visitor *v,
1511                                    void *opaque, const char *name,
1512                                    Error **errp)
1513 {
1514     uint32_t value = *(uint32_t *)opaque;
1515     visit_type_uint32(v, &value, name, errp);
1516 }
1517
1518 static void property_get_uint64_ptr(Object *obj, Visitor *v,
1519                                    void *opaque, const char *name,
1520                                    Error **errp)
1521 {
1522     uint64_t value = *(uint64_t *)opaque;
1523     visit_type_uint64(v, &value, name, errp);
1524 }
1525
1526 void object_property_add_uint8_ptr(Object *obj, const char *name,
1527                                    const uint8_t *v, Error **errp)
1528 {
1529     object_property_add(obj, name, "uint8", property_get_uint8_ptr,
1530                         NULL, NULL, (void *)v, errp);
1531 }
1532
1533 void object_property_add_uint16_ptr(Object *obj, const char *name,
1534                                     const uint16_t *v, Error **errp)
1535 {
1536     object_property_add(obj, name, "uint16", property_get_uint16_ptr,
1537                         NULL, NULL, (void *)v, errp);
1538 }
1539
1540 void object_property_add_uint32_ptr(Object *obj, const char *name,
1541                                     const uint32_t *v, Error **errp)
1542 {
1543     object_property_add(obj, name, "uint32", property_get_uint32_ptr,
1544                         NULL, NULL, (void *)v, errp);
1545 }
1546
1547 void object_property_add_uint64_ptr(Object *obj, const char *name,
1548                                     const uint64_t *v, Error **errp)
1549 {
1550     object_property_add(obj, name, "uint64", property_get_uint64_ptr,
1551                         NULL, NULL, (void *)v, errp);
1552 }
1553
1554 static void object_instance_init(Object *obj)
1555 {
1556     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
1557 }
1558
1559 static void register_types(void)
1560 {
1561     static TypeInfo interface_info = {
1562         .name = TYPE_INTERFACE,
1563         .class_size = sizeof(InterfaceClass),
1564         .abstract = true,
1565     };
1566
1567     static TypeInfo object_info = {
1568         .name = TYPE_OBJECT,
1569         .instance_size = sizeof(Object),
1570         .instance_init = object_instance_init,
1571         .abstract = true,
1572     };
1573
1574     type_interface = type_register_internal(&interface_info);
1575     type_register_internal(&object_info);
1576 }
1577
1578 type_init(register_types)