MetaClass* MetaClass::attach(STATE, Object* obj, Class* sup) {
MetaClass *meta;
meta = state->om->new_object_enduring<MetaClass>(G(klass));
meta->set_class_id(state->shared.inc_class_count());
meta->attached_instance(state, obj);
meta->setup(state);
meta->set_type_info(obj->klass()->type_info());
meta->set_packed_size(obj->klass()->packed_size());
meta->packed_ivar_info(state, obj->klass()->packed_ivar_info());
/* The superclass hierarchy for metaclasses lives in parallel to that of classes.
* This code ensures that the superclasses of metaclasses are also metaclasses.
*/
if(MetaClass* already_meta = try_as<MetaClass>(obj)) {
/* If we are attaching a metaclass to something that is already a MetaClass,
* make the metaclass's superclass be the attachee's superclass.
* klass and superclass are both metaclasses in this case.
*/
meta->klass(state, meta);
meta->superclass(state, already_meta->true_superclass(state)->metaclass(state));
} else {
/* If we are attaching to anything but a MetaClass, the new
* metaclass's class is the same as its superclass.
* This is where the superclass chains for meta/non-meta classes diverge.
* If no superclass argument was provided, we use the klass we are replacing.
*/
if(!sup) { sup = obj->klass(); }
/* Tell the new MetaClass about the attachee's existing hierarchy */
Class* meta_klass = Class::real_class(state, sup)->klass();
meta->klass(state, meta_klass);
meta->superclass(state, sup);
}
meta->name(state, state->symbol("<metaclass>"));
/* Finally, attach the new MetaClass */
obj->klass(state, meta);
return meta;
}
MetaClass* MetaClass::attach(STATE, Object* obj, Object* sup) {
MetaClass *meta;
meta = (MetaClass*)state->new_object(G(metaclass));
if(!sup) { sup = obj->klass(); }
meta->IsMeta = TRUE;
meta->attached_instance(state, obj);
meta->setup(state);
meta->superclass(state, (Module*)sup);
obj->klass(state, meta);
meta->name(state, state->symbol("<metaclass>"));
/** @todo These fields from Class are not set. Need to? --rue
Fixnum* instance_fields_; // slot
Fixnum* instance_type_; // slot
*/
return meta;
}
MetaClass* MetaClass::attach(STATE, Object* obj, Object* sup) {
MetaClass *meta;
meta = state->om->new_object_enduring<MetaClass>(G(metaclass));
meta->set_class_id(state->shared.inc_class_count());
if(!sup) { sup = obj->klass(); }
meta->attached_instance(state, obj);
meta->setup(state);
meta->superclass(state, (Module*)sup);
meta->set_type_info(obj->klass()->type_info());
obj->klass(state, meta);
meta->name(state, state->symbol("<metaclass>"));
/** @todo These fields from Class are not set. Need to? --rue
Fixnum* instance_type_; // slot
*/
return meta;
}
