qom/object.c

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