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