qom/object.c

   1 /*
   2  * QEMU Object Model
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #include "qom/object.h"
  14 #include "qemu-common.h"
  15 #include "qapi/visitor.h"
  16 #include "qapi/string-input-visitor.h"
  17 #include "qapi/string-output-visitor.h"
  18 #include "qapi/qmp/qerror.h"
  19 #include "trace.h"
  20
  21 /* TODO: replace QObject with a simpler visitor to avoid a dependency
  22  * of the QOM core on QObject?  */
  23 #include "qom/qom-qobject.h"
  24 #include "qapi/qmp/qobject.h"
  25 #include "qapi/qmp/qbool.h"
  26 #include "qapi/qmp/qint.h"
  27 #include "qapi/qmp/qstring.h"
  28
  29 #define MAX_INTERFACES 32
  30
  31 typedef struct InterfaceImpl InterfaceImpl;
  32 typedef struct TypeImpl TypeImpl;
  33
  34 struct InterfaceImpl
  35 {
  36     const char *typename;
  37 };
  38
  39 struct TypeImpl
  40 {
  41     const char *name;
  42
  43     size_t class_size;
  44
  45     size_t instance_size;
  46
  47     void (*class_init)(ObjectClass *klass, void *data);
  48     void (*class_base_init)(ObjectClass *klass, void *data);
  49     void (*class_finalize)(ObjectClass *klass, void *data);
  50
  51     void *class_data;
  52
  53     void (*instance_init)(Object *obj);
  54     void (*instance_post_init)(Object *obj);
  55     void (*instance_finalize)(Object *obj);
  56
  57     bool abstract;
  58
  59     const char *parent;
  60     TypeImpl *parent_type;
  61
  62     ObjectClass *class;
  63
  64     int num_interfaces;
  65     InterfaceImpl interfaces[MAX_INTERFACES];
  66 };
  67
  68 static Type type_interface;
  69
  70 static GHashTable *type_table_get(void)
  71 {
  72     static GHashTable *type_table;
  73
  74     if (type_table == NULL) {
  75         type_table = g_hash_table_new(g_str_hash, g_str_equal);
  76     }
  77
  78     return type_table;
  79 }
  80
  81 static bool enumerating_types;
  82
  83 static void type_table_add(TypeImpl *ti)
  84 {
  85     assert(!enumerating_types);
  86     g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
  87 }
  88
  89 static TypeImpl *type_table_lookup(const char *name)
  90 {
  91     return g_hash_table_lookup(type_table_get(), name);
  92 }
  93
  94 static TypeImpl *type_new(const TypeInfo *info)
  95 {
  96     TypeImpl *ti = g_malloc0(sizeof(*ti));
  97     int i;
  98
  99     g_assert(info->name != NULL);
 100
 101     if (type_table_lookup(info->name) != NULL) {
 102         fprintf(stderr, "Registering `%s' which already exists\n", info->name);
 103         abort();
 104     }
 105
 106     ti->name = g_strdup(info->name);
 107     ti->parent = g_strdup(info->parent);
 108
 109     ti->class_size = info->class_size;
 110     ti->instance_size = info->instance_size;
 111
 112     ti->class_init = info->class_init;
 113     ti->class_base_init = info->class_base_init;
 114     ti->class_finalize = info->class_finalize;
 115     ti->class_data = info->class_data;
 116
 117     ti->instance_init = info->instance_init;
 118     ti->instance_post_init = info->instance_post_init;
 119     ti->instance_finalize = info->instance_finalize;
 120
 121     ti->abstract = info->abstract;
 122
 123     for (i = 0; info->interfaces && info->interfaces[i].type; i++) {
 124         ti->interfaces[i].typename = g_strdup(info->interfaces[i].type);
 125     }
 126     ti->num_interfaces = i;
 127
 128     return ti;
 129 }
 130
 131 static TypeImpl *type_register_internal(const TypeInfo *info)
 132 {
 133     TypeImpl *ti;
 134     ti = type_new(info);
 135
 136     type_table_add(ti);
 137     return ti;
 138 }
 139
 140 TypeImpl *type_register(const TypeInfo *info)
 141 {
 142     assert(info->parent);
 143     return type_register_internal(info);
 144 }
 145
 146 TypeImpl *type_register_static(const TypeInfo *info)
 147 {
 148     return type_register(info);
 149 }
 150
 151 static TypeImpl *type_get_by_name(const char *name)
 152 {
 153     if (name == NULL) {
 154         return NULL;
 155     }
 156
 157     return type_table_lookup(name);
 158 }
 159
 160 static TypeImpl *type_get_parent(TypeImpl *type)
 161 {
 162     if (!type->parent_type && type->parent) {
 163         type->parent_type = type_get_by_name(type->parent);
 164         g_assert(type->parent_type != NULL);
 165     }
 166
 167     return type->parent_type;
 168 }
 169
 170 static bool type_has_parent(TypeImpl *type)
 171 {
 172     return (type->parent != NULL);
 173 }
 174
 175 static size_t type_class_get_size(TypeImpl *ti)
 176 {
 177     if (ti->class_size) {
 178         return ti->class_size;
 179     }
 180
 181     if (type_has_parent(ti)) {
 182         return type_class_get_size(type_get_parent(ti));
 183     }
 184
 185     return sizeof(ObjectClass);
 186 }
 187
 188 static size_t type_object_get_size(TypeImpl *ti)
 189 {
 190     if (ti->instance_size) {
 191         return ti->instance_size;
 192     }
 193
 194     if (type_has_parent(ti)) {
 195         return type_object_get_size(type_get_parent(ti));
 196     }
 197
 198     return 0;
 199 }
 200
 201 static bool type_is_ancestor(TypeImpl *type, TypeImpl *target_type)
 202 {
 203     assert(target_type);
 204
 205     /* Check if typename is a direct ancestor of type */
 206     while (type) {
 207         if (type == target_type) {
 208             return true;
 209         }
 210
 211         type = type_get_parent(type);
 212     }
 213
 214     return false;
 215 }
 216
 217 static void type_initialize(TypeImpl *ti);
 218
 219 static void type_initialize_interface(TypeImpl *ti, TypeImpl *interface_type,
 220                                       TypeImpl *parent_type)
 221 {
 222     InterfaceClass *new_iface;
 223     TypeInfo info = { };
 224     TypeImpl *iface_impl;
 225
 226     info.parent = parent_type->name;
 227     info.name = g_strdup_printf("%s::%s", ti->name, interface_type->name);
 228     info.abstract = true;
 229
 230     iface_impl = type_new(&info);
 231     iface_impl->parent_type = parent_type;
 232     type_initialize(iface_impl);
 233     g_free((char *)info.name);
 234
 235     new_iface = (InterfaceClass *)iface_impl->class;
 236     new_iface->concrete_class = ti->class;
 237     new_iface->interface_type = interface_type;
 238
 239     ti->class->interfaces = g_slist_append(ti->class->interfaces,
 240                                            iface_impl->class);
 241 }
 242
 243 static void type_initialize(TypeImpl *ti)
 244 {
 245     TypeImpl *parent;
 246
 247     if (ti->class) {
 248         return;
 249     }
 250
 251     ti->class_size = type_class_get_size(ti);
 252     ti->instance_size = type_object_get_size(ti);
 253
 254     ti->class = g_malloc0(ti->class_size);
 255
 256     parent = type_get_parent(ti);
 257     if (parent) {
 258         type_initialize(parent);
 259         GSList *e;
 260         int i;
 261
 262         g_assert(parent->class_size <= ti->class_size);
 263         memcpy(ti->class, parent->class, parent->class_size);
 264         ti->class->interfaces = NULL;
 265
 266         for (e = parent->class->interfaces; e; e = e->next) {
 267             InterfaceClass *iface = e->data;
 268             ObjectClass *klass = OBJECT_CLASS(iface);
 269
 270             type_initialize_interface(ti, iface->interface_type, klass->type);
 271         }
 272
 273         for (i = 0; i < ti->num_interfaces; i++) {
 274             TypeImpl *t = type_get_by_name(ti->interfaces[i].typename);
 275             for (e = ti->class->interfaces; e; e = e->next) {
 276                 TypeImpl *target_type = OBJECT_CLASS(e->data)->type;
 277
 278                 if (type_is_ancestor(target_type, t)) {
 279                     break;
 280                 }
 281             }
 282
 283             if (e) {
 284                 continue;
 285             }
 286
 287             type_initialize_interface(ti, t, t);
 288         }
 289     }
 290
 291     ti->class->type = ti;
 292
 293     while (parent) {
 294         if (parent->class_base_init) {
 295             parent->class_base_init(ti->class, ti->class_data);
 296         }
 297         parent = type_get_parent(parent);
 298     }
 299
 300     if (ti->class_init) {
 301         ti->class_init(ti->class, ti->class_data);
 302     }
 303 }
 304
 305 static void object_init_with_type(Object *obj, TypeImpl *ti)
 306 {
 307     if (type_has_parent(ti)) {
 308         object_init_with_type(obj, type_get_parent(ti));
 309     }
 310
 311     if (ti->instance_init) {
 312         ti->instance_init(obj);
 313     }
 314 }
 315
 316 static void object_post_init_with_type(Object *obj, TypeImpl *ti)
 317 {
 318     if (ti->instance_post_init) {
 319         ti->instance_post_init(obj);
 320     }
 321
 322     if (type_has_parent(ti)) {
 323         object_post_init_with_type(obj, type_get_parent(ti));
 324     }
 325 }
 326
 327 void object_initialize_with_type(void *data, size_t size, TypeImpl *type)
 328 {
 329     Object *obj = data;
 330
 331     g_assert(type != NULL);
 332     type_initialize(type);
 333
 334     g_assert(type->instance_size >= sizeof(Object));
 335     g_assert(type->abstract == false);
 336     g_assert(size >= type->instance_size);
 337
 338     memset(obj, 0, type->instance_size);
 339     obj->class = type->class;
 340     object_ref(obj);
 341     QTAILQ_INIT(&obj->properties);
 342     object_init_with_type(obj, type);
 343     object_post_init_with_type(obj, type);
 344 }
 345
 346 void object_initialize(void *data, size_t size, const char *typename)
 347 {
 348     TypeImpl *type = type_get_by_name(typename);
 349
 350     object_initialize_with_type(data, size, type);
 351 }
 352
 353 static inline bool object_property_is_child(ObjectProperty *prop)
 354 {
 355     return strstart(prop->type, "child<", NULL);
 356 }
 357
 358 static inline bool object_property_is_link(ObjectProperty *prop)
 359 {
 360     return strstart(prop->type, "link<", NULL);
 361 }
 362
 363 static void object_property_del_all(Object *obj)
 364 {
 365     while (!QTAILQ_EMPTY(&obj->properties)) {
 366         ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
 367
 368         QTAILQ_REMOVE(&obj->properties, prop, node);
 369
 370         if (prop->release) {
 371             prop->release(obj, prop->name, prop->opaque);
 372         }
 373
 374         g_free(prop->name);
 375         g_free(prop->type);
 376         g_free(prop);
 377     }
 378 }
 379
 380 static void object_property_del_child(Object *obj, Object *child, Error **errp)
 381 {
 382     ObjectProperty *prop;
 383
 384     QTAILQ_FOREACH(prop, &obj->properties, node) {
 385         if (object_property_is_child(prop) && prop->opaque == child) {
 386             object_property_del(obj, prop->name, errp);
 387             break;
 388         }
 389     }
 390 }
 391
 392 void object_unparent(Object *obj)
 393 {
 394     if (!obj->parent) {
 395         return;
 396     }
 397
 398     object_ref(obj);
 399     if (obj->class->unparent) {
 400         (obj->class->unparent)(obj);
 401     }
 402     if (obj->parent) {
 403         object_property_del_child(obj->parent, obj, NULL);
 404     }
 405     object_unref(obj);
 406 }
 407
 408 static void object_deinit(Object *obj, TypeImpl *type)
 409 {
 410     if (type->instance_finalize) {
 411         type->instance_finalize(obj);
 412     }
 413
 414     if (type_has_parent(type)) {
 415         object_deinit(obj, type_get_parent(type));
 416     }
 417 }
 418
 419 static void object_finalize(void *data)
 420 {
 421     Object *obj = data;
 422     TypeImpl *ti = obj->class->type;
 423
 424     object_deinit(obj, ti);
 425     object_property_del_all(obj);
 426
 427     g_assert(obj->ref == 0);
 428     if (obj->free) {
 429         obj->free(obj);
 430     }
 431 }
 432
 433 Object *object_new_with_type(Type type)
 434 {
 435     Object *obj;
 436
 437     g_assert(type != NULL);
 438     type_initialize(type);
 439
 440     obj = g_malloc(type->instance_size);
 441     object_initialize_with_type(obj, type->instance_size, type);
 442     obj->free = g_free;
 443
 444     return obj;
 445 }
 446
 447 Object *object_new(const char *typename)
 448 {
 449     TypeImpl *ti = type_get_by_name(typename);
 450
 451     return object_new_with_type(ti);
 452 }
 453
 454 Object *object_dynamic_cast(Object *obj, const char *typename)
 455 {
 456     if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) {
 457         return obj;
 458     }
 459
 460     return NULL;
 461 }
 462
 463 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
 464                                    const char *file, int line, const char *func)
 465 {
 466     trace_object_dynamic_cast_assert(obj ? obj->class->type->name : "(null)",
 467                                      typename, file, line, func);
 468
 469 #ifdef CONFIG_QOM_CAST_DEBUG
 470     int i;
 471     Object *inst;
 472
 473     for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
 474         if (obj->class->object_cast_cache[i] == typename) {
 475             goto out;
 476         }
 477     }
 478
 479     inst = object_dynamic_cast(obj, typename);
 480
 481     if (!inst && obj) {
 482         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 483                 file, line, func, obj, typename);
 484         abort();
 485     }
 486
 487     assert(obj == inst);
 488
 489     if (obj && obj == inst) {
 490         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 491             obj->class->object_cast_cache[i - 1] =
 492                     obj->class->object_cast_cache[i];
 493         }
 494         obj->class->object_cast_cache[i - 1] = typename;
 495     }
 496
 497 out:
 498 #endif
 499     return obj;
 500 }
 501
 502 ObjectClass *object_class_dynamic_cast(ObjectClass *class,
 503                                        const char *typename)
 504 {
 505     ObjectClass *ret = NULL;
 506     TypeImpl *target_type;
 507     TypeImpl *type;
 508
 509     if (!class) {
 510         return NULL;
 511     }
 512
 513     /* A simple fast path that can trigger a lot for leaf classes.  */
 514     type = class->type;
 515     if (type->name == typename) {
 516         return class;
 517     }
 518
 519     target_type = type_get_by_name(typename);
 520     if (!target_type) {
 521         /* target class type unknown, so fail the cast */
 522         return NULL;
 523     }
 524
 525     if (type->class->interfaces &&
 526             type_is_ancestor(target_type, type_interface)) {
 527         int found = 0;
 528         GSList *i;
 529
 530         for (i = class->interfaces; i; i = i->next) {
 531             ObjectClass *target_class = i->data;
 532
 533             if (type_is_ancestor(target_class->type, target_type)) {
 534                 ret = target_class;
 535                 found++;
 536             }
 537          }
 538
 539         /* The match was ambiguous, don't allow a cast */
 540         if (found > 1) {
 541             ret = NULL;
 542         }
 543     } else if (type_is_ancestor(type, target_type)) {
 544         ret = class;
 545     }
 546
 547     return ret;
 548 }
 549
 550 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
 551                                               const char *typename,
 552                                               const char *file, int line,
 553                                               const char *func)
 554 {
 555     ObjectClass *ret;
 556
 557     trace_object_class_dynamic_cast_assert(class ? class->type->name : "(null)",
 558                                            typename, file, line, func);
 559
 560 #ifdef CONFIG_QOM_CAST_DEBUG
 561     int i;
 562
 563     for (i = 0; class && i < OBJECT_CLASS_CAST_CACHE; i++) {
 564         if (class->class_cast_cache[i] == typename) {
 565             ret = class;
 566             goto out;
 567         }
 568     }
 569 #else
 570     if (!class || !class->interfaces) {
 571         return class;
 572     }
 573 #endif
 574
 575     ret = object_class_dynamic_cast(class, typename);
 576     if (!ret && class) {
 577         fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n",
 578                 file, line, func, class, typename);
 579         abort();
 580     }
 581
 582 #ifdef CONFIG_QOM_CAST_DEBUG
 583     if (class && ret == class) {
 584         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
 585             class->class_cast_cache[i - 1] = class->class_cast_cache[i];
 586         }
 587         class->class_cast_cache[i - 1] = typename;
 588     }
 589 out:
 590 #endif
 591     return ret;
 592 }
 593
 594 const char *object_get_typename(Object *obj)
 595 {
 596     return obj->class->type->name;
 597 }
 598
 599 ObjectClass *object_get_class(Object *obj)
 600 {
 601     return obj->class;
 602 }
 603
 604 bool object_class_is_abstract(ObjectClass *klass)
 605 {
 606     return klass->type->abstract;
 607 }
 608
 609 const char *object_class_get_name(ObjectClass *klass)
 610 {
 611     return klass->type->name;
 612 }
 613
 614 ObjectClass *object_class_by_name(const char *typename)
 615 {
 616     TypeImpl *type = type_get_by_name(typename);
 617
 618     if (!type) {
 619         return NULL;
 620     }
 621
 622     type_initialize(type);
 623
 624     return type->class;
 625 }
 626
 627 ObjectClass *object_class_get_parent(ObjectClass *class)
 628 {
 629     TypeImpl *type = type_get_parent(class->type);
 630
 631     if (!type) {
 632         return NULL;
 633     }
 634
 635     type_initialize(type);
 636
 637     return type->class;
 638 }
 639
 640 typedef struct OCFData
 641 {
 642     void (*fn)(ObjectClass *klass, void *opaque);
 643     const char *implements_type;
 644     bool include_abstract;
 645     void *opaque;
 646 } OCFData;
 647
 648 static void object_class_foreach_tramp(gpointer key, gpointer value,
 649                                        gpointer opaque)
 650 {
 651     OCFData *data = opaque;
 652     TypeImpl *type = value;
 653     ObjectClass *k;
 654
 655     type_initialize(type);
 656     k = type->class;
 657
 658     if (!data->include_abstract && type->abstract) {
 659         return;
 660     }
 661
 662     if (data->implements_type &&
 663         !object_class_dynamic_cast(k, data->implements_type)) {
 664         return;
 665     }
 666
 667     data->fn(k, data->opaque);
 668 }
 669
 670 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 671                           const char *implements_type, bool include_abstract,
 672                           void *opaque)
 673 {
 674     OCFData data = { fn, implements_type, include_abstract, opaque };
 675
 676     enumerating_types = true;
 677     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 678     enumerating_types = false;
 679 }
 680
 681 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
 682                          void *opaque)
 683 {
 684     ObjectProperty *prop;
 685     int ret = 0;
 686
 687     QTAILQ_FOREACH(prop, &obj->properties, node) {
 688         if (object_property_is_child(prop)) {
 689             ret = fn(prop->opaque, opaque);
 690             if (ret != 0) {
 691                 break;
 692             }
 693         }
 694     }
 695     return ret;
 696 }
 697
 698 static void object_class_get_list_tramp(ObjectClass *klass, void *opaque)
 699 {
 700     GSList **list = opaque;
 701
 702     *list = g_slist_prepend(*list, klass);
 703 }
 704
 705 GSList *object_class_get_list(const char *implements_type,
 706                               bool include_abstract)
 707 {
 708     GSList *list = NULL;
 709
 710     object_class_foreach(object_class_get_list_tramp,
 711                          implements_type, include_abstract, &list);
 712     return list;
 713 }
 714
 715 void object_ref(Object *obj)
 716 {
 717      atomic_inc(&obj->ref);
 718 }
 719
 720 void object_unref(Object *obj)
 721 {
 722     g_assert(obj->ref > 0);
 723
 724     /* parent always holds a reference to its children */
 725     if (atomic_fetch_dec(&obj->ref) == 1) {
 726         object_finalize(obj);
 727     }
 728 }
 729
 730 void object_property_add(Object *obj, const char *name, const char *type,
 731                          ObjectPropertyAccessor *get,
 732                          ObjectPropertyAccessor *set,
 733                          ObjectPropertyRelease *release,
 734                          void *opaque, Error **errp)
 735 {
 736     ObjectProperty *prop;
 737
 738     QTAILQ_FOREACH(prop, &obj->properties, node) {
 739         if (strcmp(prop->name, name) == 0) {
 740             error_setg(errp, "attempt to add duplicate property '%s'"
 741                        " to object (type '%s')", name,
 742                        object_get_typename(obj));
 743             return;
 744         }
 745     }
 746
 747     prop = g_malloc0(sizeof(*prop));
 748
 749     prop->name = g_strdup(name);
 750     prop->type = g_strdup(type);
 751
 752     prop->get = get;
 753     prop->set = set;
 754     prop->release = release;
 755     prop->opaque = opaque;
 756
 757     QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
 758 }
 759
 760 ObjectProperty *object_property_find(Object *obj, const char *name,
 761                                      Error **errp)
 762 {
 763     ObjectProperty *prop;
 764
 765     QTAILQ_FOREACH(prop, &obj->properties, node) {
 766         if (strcmp(prop->name, name) == 0) {
 767             return prop;
 768         }
 769     }
 770
 771     error_setg(errp, "Property '.%s' not found", name);
 772     return NULL;
 773 }
 774
 775 void object_property_del(Object *obj, const char *name, Error **errp)
 776 {
 777     ObjectProperty *prop = object_property_find(obj, name, errp);
 778     if (prop == NULL) {
 779         return;
 780     }
 781
 782     if (prop->release) {
 783         prop->release(obj, name, prop->opaque);
 784     }
 785
 786     QTAILQ_REMOVE(&obj->properties, prop, node);
 787
 788     g_free(prop->name);
 789     g_free(prop->type);
 790     g_free(prop);
 791 }
 792
 793 void object_property_get(Object *obj, Visitor *v, const char *name,
 794                          Error **errp)
 795 {
 796     ObjectProperty *prop = object_property_find(obj, name, errp);
 797     if (prop == NULL) {
 798         return;
 799     }
 800
 801     if (!prop->get) {
 802         error_set(errp, QERR_PERMISSION_DENIED);
 803     } else {
 804         prop->get(obj, v, prop->opaque, name, errp);
 805     }
 806 }
 807
 808 void object_property_set(Object *obj, Visitor *v, const char *name,
 809                          Error **errp)
 810 {
 811     ObjectProperty *prop = object_property_find(obj, name, errp);
 812     if (prop == NULL) {
 813         return;
 814     }
 815
 816     if (!prop->set) {
 817         error_set(errp, QERR_PERMISSION_DENIED);
 818     } else {
 819         prop->set(obj, v, prop->opaque, name, errp);
 820     }
 821 }
 822
 823 void object_property_set_str(Object *obj, const char *value,
 824                              const char *name, Error **errp)
 825 {
 826     QString *qstr = qstring_from_str(value);
 827     object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
 828
 829     QDECREF(qstr);
 830 }
 831
 832 char *object_property_get_str(Object *obj, const char *name,
 833                               Error **errp)
 834 {
 835     QObject *ret = object_property_get_qobject(obj, name, errp);
 836     QString *qstring;
 837     char *retval;
 838
 839     if (!ret) {
 840         return NULL;
 841     }
 842     qstring = qobject_to_qstring(ret);
 843     if (!qstring) {
 844         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
 845         retval = NULL;
 846     } else {
 847         retval = g_strdup(qstring_get_str(qstring));
 848     }
 849
 850     QDECREF(qstring);
 851     return retval;
 852 }
 853
 854 void object_property_set_link(Object *obj, Object *value,
 855                               const char *name, Error **errp)
 856 {
 857     gchar *path = object_get_canonical_path(value);
 858     object_property_set_str(obj, path, name, errp);
 859     g_free(path);
 860 }
 861
 862 Object *object_property_get_link(Object *obj, const char *name,
 863                                  Error **errp)
 864 {
 865     char *str = object_property_get_str(obj, name, errp);
 866     Object *target = NULL;
 867
 868     if (str && *str) {
 869         target = object_resolve_path(str, NULL);
 870         if (!target) {
 871             error_set(errp, QERR_DEVICE_NOT_FOUND, str);
 872         }
 873     }
 874
 875     g_free(str);
 876     return target;
 877 }
 878
 879 void object_property_set_bool(Object *obj, bool value,
 880                               const char *name, Error **errp)
 881 {
 882     QBool *qbool = qbool_from_int(value);
 883     object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
 884
 885     QDECREF(qbool);
 886 }
 887
 888 bool object_property_get_bool(Object *obj, const char *name,
 889                               Error **errp)
 890 {
 891     QObject *ret = object_property_get_qobject(obj, name, errp);
 892     QBool *qbool;
 893     bool retval;
 894
 895     if (!ret) {
 896         return false;
 897     }
 898     qbool = qobject_to_qbool(ret);
 899     if (!qbool) {
 900         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
 901         retval = false;
 902     } else {
 903         retval = qbool_get_int(qbool);
 904     }
 905
 906     QDECREF(qbool);
 907     return retval;
 908 }
 909
 910 void object_property_set_int(Object *obj, int64_t value,
 911                              const char *name, Error **errp)
 912 {
 913     QInt *qint = qint_from_int(value);
 914     object_property_set_qobject(obj, QOBJECT(qint), name, errp);
 915
 916     QDECREF(qint);
 917 }
 918
 919 int64_t object_property_get_int(Object *obj, const char *name,
 920                                 Error **errp)
 921 {
 922     QObject *ret = object_property_get_qobject(obj, name, errp);
 923     QInt *qint;
 924     int64_t retval;
 925
 926     if (!ret) {
 927         return -1;
 928     }
 929     qint = qobject_to_qint(ret);
 930     if (!qint) {
 931         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
 932         retval = -1;
 933     } else {
 934         retval = qint_get_int(qint);
 935     }
 936
 937     QDECREF(qint);
 938     return retval;
 939 }
 940
 941 void object_property_parse(Object *obj, const char *string,
 942                            const char *name, Error **errp)
 943 {
 944     StringInputVisitor *mi;
 945     mi = string_input_visitor_new(string);
 946     object_property_set(obj, string_input_get_visitor(mi), name, errp);
 947
 948     string_input_visitor_cleanup(mi);
 949 }
 950
 951 char *object_property_print(Object *obj, const char *name, bool human,
 952                             Error **errp)
 953 {
 954     StringOutputVisitor *mo;
 955     char *string;
 956
 957     mo = string_output_visitor_new(human);
 958     object_property_get(obj, string_output_get_visitor(mo), name, errp);
 959     string = string_output_get_string(mo);
 960     string_output_visitor_cleanup(mo);
 961     return string;
 962 }
 963
 964 const char *object_property_get_type(Object *obj, const char *name, Error **errp)
 965 {
 966     ObjectProperty *prop = object_property_find(obj, name, errp);
 967     if (prop == NULL) {
 968         return NULL;
 969     }
 970
 971     return prop->type;
 972 }
 973
 974 Object *object_get_root(void)
 975 {
 976     static Object *root;
 977
 978     if (!root) {
 979         root = object_new("container");
 980     }
 981
 982     return root;
 983 }
 984
 985 static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
 986                                       const char *name, Error **errp)
 987 {
 988     Object *child = opaque;
 989     gchar *path;
 990
 991     path = object_get_canonical_path(child);
 992     visit_type_str(v, &path, name, errp);
 993     g_free(path);
 994 }
 995
 996 static void object_finalize_child_property(Object *obj, const char *name,
 997                                            void *opaque)
 998 {
 999     Object *child = opaque;
1000
1001     object_unref(child);
1002 }
1003
1004 void object_property_add_child(Object *obj, const char *name,
1005                                Object *child, Error **errp)
1006 {
1007     Error *local_err = NULL;
1008     gchar *type;
1009
1010     type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
1011
1012     object_property_add(obj, name, type, object_get_child_property, NULL,
1013                         object_finalize_child_property, child, &local_err);
1014     if (local_err) {
1015         error_propagate(errp, local_err);
1016         goto out;
1017     }
1018     object_ref(child);
1019     g_assert(child->parent == NULL);
1020     child->parent = obj;
1021
1022 out:
1023     g_free(type);
1024 }
1025
1026 void object_property_allow_set_link(Object *obj, const char *name,
1027                                     Object *val, Error **errp)
1028 {
1029     /* Allow the link to be set, always */
1030 }
1031
1032 typedef struct {
1033     Object **child;
1034     void (*check)(Object *, const char *, Object *, Error **);
1035     ObjectPropertyLinkFlags flags;
1036 } LinkProperty;
1037
1038 static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
1039                                      const char *name, Error **errp)
1040 {
1041     LinkProperty *lprop = opaque;
1042     Object **child = lprop->child;
1043     gchar *path;
1044
1045     if (*child) {
1046         path = object_get_canonical_path(*child);
1047         visit_type_str(v, &path, name, errp);
1048         g_free(path);
1049     } else {
1050         path = (gchar *)"";
1051         visit_type_str(v, &path, name, errp);
1052     }
1053 }
1054
1055 /*
1056  * object_resolve_link:
1057  *
1058  * Lookup an object and ensure its type matches the link property type.  This
1059  * is similar to object_resolve_path() except type verification against the
1060  * link property is performed.
1061  *
1062  * Returns: The matched object or NULL on path lookup failures.
1063  */
1064 static Object *object_resolve_link(Object *obj, const char *name,
1065                                    const char *path, Error **errp)
1066 {
1067     const char *type;
1068     gchar *target_type;
1069     bool ambiguous = false;
1070     Object *target;
1071
1072     /* Go from link<FOO> to FOO.  */
1073     type = object_property_get_type(obj, name, NULL);
1074     target_type = g_strndup(&type[5], strlen(type) - 6);
1075     target = object_resolve_path_type(path, target_type, &ambiguous);
1076
1077     if (ambiguous) {
1078         error_set(errp, ERROR_CLASS_GENERIC_ERROR,
1079                   "Path '%s' does not uniquely identify an object", path);
1080     } else if (!target) {
1081         target = object_resolve_path(path, &ambiguous);
1082         if (target || ambiguous) {
1083             error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
1084         } else {
1085             error_set(errp, QERR_DEVICE_NOT_FOUND, path);
1086         }
1087         target = NULL;
1088     }
1089     g_free(target_type);
1090
1091     return target;
1092 }
1093
1094 static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
1095                                      const char *name, Error **errp)
1096 {
1097     Error *local_err = NULL;
1098     LinkProperty *prop = opaque;
1099     Object **child = prop->child;
1100     Object *old_target = *child;
1101     Object *new_target = NULL;
1102     char *path = NULL;
1103
1104     visit_type_str(v, &path, name, &local_err);
1105
1106     if (!local_err && strcmp(path, "") != 0) {
1107         new_target = object_resolve_link(obj, name, path, &local_err);
1108     }
1109
1110     g_free(path);
1111     if (local_err) {
1112         error_propagate(errp, local_err);
1113         return;
1114     }
1115
1116     prop->check(obj, name, new_target, &local_err);
1117     if (local_err) {
1118         error_propagate(errp, local_err);
1119         return;
1120     }
1121
1122     if (new_target) {
1123         object_ref(new_target);
1124     }
1125     *child = new_target;
1126     if (old_target != NULL) {
1127         object_unref(old_target);
1128     }
1129 }
1130
1131 static void object_release_link_property(Object *obj, const char *name,
1132                                          void *opaque)
1133 {
1134     LinkProperty *prop = opaque;
1135
1136     if ((prop->flags & OBJ_PROP_LINK_UNREF_ON_RELEASE) && *prop->child) {
1137         object_unref(*prop->child);
1138     }
1139     g_free(prop);
1140 }
1141
1142 void object_property_add_link(Object *obj, const char *name,
1143                               const char *type, Object **child,
1144                               void (*check)(Object *, const char *,
1145                                             Object *, Error **),
1146                               ObjectPropertyLinkFlags flags,
1147                               Error **errp)
1148 {
1149     Error *local_err = NULL;
1150     LinkProperty *prop = g_malloc(sizeof(*prop));
1151     gchar *full_type;
1152
1153     prop->child = child;
1154     prop->check = check;
1155     prop->flags = flags;
1156
1157     full_type = g_strdup_printf("link<%s>", type);
1158
1159     object_property_add(obj, name, full_type,
1160                         object_get_link_property,
1161                         check ? object_set_link_property : NULL,
1162                         object_release_link_property,
1163                         prop,
1164                         &local_err);
1165     if (local_err) {
1166         error_propagate(errp, local_err);
1167         g_free(prop);
1168     }
1169
1170     g_free(full_type);
1171 }
1172
1173 gchar *object_get_canonical_path_component(Object *obj)
1174 {
1175     ObjectProperty *prop = NULL;
1176
1177     g_assert(obj);
1178     g_assert(obj->parent != NULL);
1179
1180     QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
1181         if (!object_property_is_child(prop)) {
1182             continue;
1183         }
1184
1185         if (prop->opaque == obj) {
1186             return g_strdup(prop->name);
1187         }
1188     }
1189
1190     /* obj had a parent but was not a child, should never happen */
1191     g_assert_not_reached();
1192     return NULL;
1193 }
1194
1195 gchar *object_get_canonical_path(Object *obj)
1196 {
1197     Object *root = object_get_root();
1198     char *newpath, *path = NULL;
1199
1200     while (obj != root) {
1201         char *component = object_get_canonical_path_component(obj);
1202
1203         if (path) {
1204             newpath = g_strdup_printf("%s/%s", component, path);
1205             g_free(component);
1206             g_free(path);
1207             path = newpath;
1208         } else {
1209             path = component;
1210         }
1211
1212         obj = obj->parent;
1213     }
1214
1215     newpath = g_strdup_printf("/%s", path ? path : "");
1216     g_free(path);
1217
1218     return newpath;
1219 }
1220
1221 Object *object_resolve_path_component(Object *parent, const gchar *part)
1222 {
1223     ObjectProperty *prop = object_property_find(parent, part, NULL);
1224     if (prop == NULL) {
1225         return NULL;
1226     }
1227
1228     if (object_property_is_link(prop)) {
1229         LinkProperty *lprop = prop->opaque;
1230         return *lprop->child;
1231     } else if (object_property_is_child(prop)) {
1232         return prop->opaque;
1233     } else {
1234         return NULL;
1235     }
1236 }
1237
1238 static Object *object_resolve_abs_path(Object *parent,
1239                                           gchar **parts,
1240                                           const char *typename,
1241                                           int index)
1242 {
1243     Object *child;
1244
1245     if (parts[index] == NULL) {
1246         return object_dynamic_cast(parent, typename);
1247     }
1248
1249     if (strcmp(parts[index], "") == 0) {
1250         return object_resolve_abs_path(parent, parts, typename, index + 1);
1251     }
1252
1253     child = object_resolve_path_component(parent, parts[index]);
1254     if (!child) {
1255         return NULL;
1256     }
1257
1258     return object_resolve_abs_path(child, parts, typename, index + 1);
1259 }
1260
1261 static Object *object_resolve_partial_path(Object *parent,
1262                                               gchar **parts,
1263                                               const char *typename,
1264                                               bool *ambiguous)
1265 {
1266     Object *obj;
1267     ObjectProperty *prop;
1268
1269     obj = object_resolve_abs_path(parent, parts, typename, 0);
1270
1271     QTAILQ_FOREACH(prop, &parent->properties, node) {
1272         Object *found;
1273
1274         if (!object_property_is_child(prop)) {
1275             continue;
1276         }
1277
1278         found = object_resolve_partial_path(prop->opaque, parts,
1279                                             typename, ambiguous);
1280         if (found) {
1281             if (obj) {
1282                 if (ambiguous) {
1283                     *ambiguous = true;
1284                 }
1285                 return NULL;
1286             }
1287             obj = found;
1288         }
1289
1290         if (ambiguous && *ambiguous) {
1291             return NULL;
1292         }
1293     }
1294
1295     return obj;
1296 }
1297
1298 Object *object_resolve_path_type(const char *path, const char *typename,
1299                                  bool *ambiguous)
1300 {
1301     Object *obj;
1302     gchar **parts;
1303
1304     parts = g_strsplit(path, "/", 0);
1305     assert(parts);
1306
1307     if (parts[0] == NULL || strcmp(parts[0], "") != 0) {
1308         if (ambiguous) {
1309             *ambiguous = false;
1310         }
1311         obj = object_resolve_partial_path(object_get_root(), parts,
1312                                           typename, ambiguous);
1313     } else {
1314         obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
1315     }
1316
1317     g_strfreev(parts);
1318
1319     return obj;
1320 }
1321
1322 Object *object_resolve_path(const char *path, bool *ambiguous)
1323 {
1324     return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
1325 }
1326
1327 typedef struct StringProperty
1328 {
1329     char *(*get)(Object *, Error **);
1330     void (*set)(Object *, const char *, Error **);
1331 } StringProperty;
1332
1333 static void property_get_str(Object *obj, Visitor *v, void *opaque,
1334                              const char *name, Error **errp)
1335 {
1336     StringProperty *prop = opaque;
1337     char *value;
1338
1339     value = prop->get(obj, errp);
1340     if (value) {
1341         visit_type_str(v, &value, name, errp);
1342         g_free(value);
1343     }
1344 }
1345
1346 static void property_set_str(Object *obj, Visitor *v, void *opaque,
1347                              const char *name, Error **errp)
1348 {
1349     StringProperty *prop = opaque;
1350     char *value;
1351     Error *local_err = NULL;
1352
1353     visit_type_str(v, &value, name, &local_err);
1354     if (local_err) {
1355         error_propagate(errp, local_err);
1356         return;
1357     }
1358
1359     prop->set(obj, value, errp);
1360     g_free(value);
1361 }
1362
1363 static void property_release_str(Object *obj, const char *name,
1364                                  void *opaque)
1365 {
1366     StringProperty *prop = opaque;
1367     g_free(prop);
1368 }
1369
1370 void object_property_add_str(Object *obj, const char *name,
1371                            char *(*get)(Object *, Error **),
1372                            void (*set)(Object *, const char *, Error **),
1373                            Error **errp)
1374 {
1375     Error *local_err = NULL;
1376     StringProperty *prop = g_malloc0(sizeof(*prop));
1377
1378     prop->get = get;
1379     prop->set = set;
1380
1381     object_property_add(obj, name, "string",
1382                         get ? property_get_str : NULL,
1383                         set ? property_set_str : NULL,
1384                         property_release_str,
1385                         prop, &local_err);
1386     if (local_err) {
1387         error_propagate(errp, local_err);
1388         g_free(prop);
1389     }
1390 }
1391
1392 typedef struct BoolProperty
1393 {
1394     bool (*get)(Object *, Error **);
1395     void (*set)(Object *, bool, Error **);
1396 } BoolProperty;
1397
1398 static void property_get_bool(Object *obj, Visitor *v, void *opaque,
1399                               const char *name, Error **errp)
1400 {
1401     BoolProperty *prop = opaque;
1402     bool value;
1403
1404     value = prop->get(obj, errp);
1405     visit_type_bool(v, &value, name, errp);
1406 }
1407
1408 static void property_set_bool(Object *obj, Visitor *v, void *opaque,
1409                               const char *name, Error **errp)
1410 {
1411     BoolProperty *prop = opaque;
1412     bool value;
1413     Error *local_err = NULL;
1414
1415     visit_type_bool(v, &value, name, &local_err);
1416     if (local_err) {
1417         error_propagate(errp, local_err);
1418         return;
1419     }
1420
1421     prop->set(obj, value, errp);
1422 }
1423
1424 static void property_release_bool(Object *obj, const char *name,
1425                                   void *opaque)
1426 {
1427     BoolProperty *prop = opaque;
1428     g_free(prop);
1429 }
1430
1431 void object_property_add_bool(Object *obj, const char *name,
1432                               bool (*get)(Object *, Error **),
1433                               void (*set)(Object *, bool, Error **),
1434                               Error **errp)
1435 {
1436     Error *local_err = NULL;
1437     BoolProperty *prop = g_malloc0(sizeof(*prop));
1438
1439     prop->get = get;
1440     prop->set = set;
1441
1442     object_property_add(obj, name, "bool",
1443                         get ? property_get_bool : NULL,
1444                         set ? property_set_bool : NULL,
1445                         property_release_bool,
1446                         prop, &local_err);
1447     if (local_err) {
1448         error_propagate(errp, local_err);
1449         g_free(prop);
1450     }
1451 }
1452
1453 static char *qdev_get_type(Object *obj, Error **errp)
1454 {
1455     return g_strdup(object_get_typename(obj));
1456 }
1457
1458 static void property_get_uint8_ptr(Object *obj, Visitor *v,
1459                                    void *opaque, const char *name,
1460                                    Error **errp)
1461 {
1462     uint8_t value = *(uint8_t *)opaque;
1463     visit_type_uint8(v, &value, name, errp);
1464 }
1465
1466 static void property_get_uint16_ptr(Object *obj, Visitor *v,
1467                                    void *opaque, const char *name,
1468                                    Error **errp)
1469 {
1470     uint16_t value = *(uint16_t *)opaque;
1471     visit_type_uint16(v, &value, name, errp);
1472 }
1473
1474 static void property_get_uint32_ptr(Object *obj, Visitor *v,
1475                                    void *opaque, const char *name,
1476                                    Error **errp)
1477 {
1478     uint32_t value = *(uint32_t *)opaque;
1479     visit_type_uint32(v, &value, name, errp);
1480 }
1481
1482 static void property_get_uint64_ptr(Object *obj, Visitor *v,
1483                                    void *opaque, const char *name,
1484                                    Error **errp)
1485 {
1486     uint64_t value = *(uint64_t *)opaque;
1487     visit_type_uint64(v, &value, name, errp);
1488 }
1489
1490 void object_property_add_uint8_ptr(Object *obj, const char *name,
1491                                    const uint8_t *v, Error **errp)
1492 {
1493     object_property_add(obj, name, "uint8", property_get_uint8_ptr,
1494                         NULL, NULL, (void *)v, errp);
1495 }
1496
1497 void object_property_add_uint16_ptr(Object *obj, const char *name,
1498                                     const uint16_t *v, Error **errp)
1499 {
1500     object_property_add(obj, name, "uint16", property_get_uint16_ptr,
1501                         NULL, NULL, (void *)v, errp);
1502 }
1503
1504 void object_property_add_uint32_ptr(Object *obj, const char *name,
1505                                     const uint32_t *v, Error **errp)
1506 {
1507     object_property_add(obj, name, "uint32", property_get_uint32_ptr,
1508                         NULL, NULL, (void *)v, errp);
1509 }
1510
1511 void object_property_add_uint64_ptr(Object *obj, const char *name,
1512                                     const uint64_t *v, Error **errp)
1513 {
1514     object_property_add(obj, name, "uint64", property_get_uint64_ptr,
1515                         NULL, NULL, (void *)v, errp);
1516 }
1517
1518 static void object_instance_init(Object *obj)
1519 {
1520     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
1521 }
1522
1523 static void register_types(void)
1524 {
1525     static TypeInfo interface_info = {
1526         .name = TYPE_INTERFACE,
1527         .class_size = sizeof(InterfaceClass),
1528         .abstract = true,
1529     };
1530
1531     static TypeInfo object_info = {
1532         .name = TYPE_OBJECT,
1533         .instance_size = sizeof(Object),
1534         .instance_init = object_instance_init,
1535         .abstract = true,
1536     };
1537
1538     type_interface = type_register_internal(&interface_info);
1539     type_register_internal(&object_info);
1540 }
1541
1542 type_init(register_types)