struct objectref * class_resolver_lookup_string(struct vm * vm,
                                                struct class_entry * class_entry,
                                                const int string_index)
{
  debugf("class_resolver_lookup_string: %d\n", string_index);
  if (class_entry->attribute_entry[string_index - 1].string_objectref != nullptr) {
    debugf("class_resolver_lookup_string: [cached]\n");
    return class_entry->attribute_entry[string_index - 1].string_objectref;
  }

  struct constant * string_constant = &class_entry->class_file->constant_pool[string_index - 1];
  assert(string_constant->tag == CONSTANT_String);

  struct constant * utf8_constant = &class_entry->class_file->constant_pool[string_constant->string.string_index - 1];
  assert(utf8_constant->tag == CONSTANT_Utf8);

  struct class_entry * string_class_entry = class_resolver_lookup_class(vm->class_hash_table.length,
                                                                        vm->class_hash_table.entry,
                                                                        (const uint8_t *)"java/lang/String",
                                                                        16);
  debugf("string class entry: %p\n", string_class_entry);

  int32_t count = utf8_constant->utf8.length;
  struct arrayref * arrayref = prim_array_allocate(vm, 1, count);
  assert(arrayref != nullptr);
  arrayref->class_entry = nullptr; // byte[]
  arrayref->length = utf8_constant->utf8.length;
  for (int i = 0; i < utf8_constant->utf8.length; i++) {
    arrayref->u8[i] = utf8_constant->utf8.bytes[i];
  }

  assert(string_class_entry != nullptr);
  int fields_count = string_class_entry->instance_fields_count;
  struct objectref * objectref = obj_allocate(vm, fields_count);
  assert(objectref != nullptr);
  objectref->class_entry = string_class_entry;
  for (int i = 0; i < fields_count; i++) {
    objectref->oref[i] = nullptr;
  }
  objectref->aref[0] = arrayref;

  // cache the result
  class_entry->attribute_entry[string_index - 1].string_objectref = objectref;

  return objectref;
}

static inline void class_entry_field_entry_from_constant_index(struct vm * vm,
                                                               int32_t index,
                                                               struct class_entry ** class_entry,
                                                               struct field_entry ** field_entry,
                                                               struct constant ** field_descriptor_constant)
{
  struct constant * fieldref_constant = &vm->current_frame->class_entry->class_file->constant_pool[index - 1];
  #ifdef DEBUG
  assert(fieldref_constant->tag == CONSTANT_Fieldref);
  #endif

  *class_entry = class_resolver_lookup_class_from_class_index(vm->class_hash_table.length,
                                                              vm->class_hash_table.entry,
                                                              vm->current_frame->class_entry,
                                                              fieldref_constant->fieldref.class_index);

  assert(*class_entry != nullptr);

  int fields_hash_table_length = (*class_entry)->fields.length;
  struct hash_table_entry * fields_hash_table = (*class_entry)->fields.entry;

  *field_entry = class_resolver_lookup_field_from_fieldref_index(fields_hash_table_length,
                                                                 fields_hash_table,
                                                                 vm->current_frame->class_entry,
                                                                 index);
  assert(*field_entry != nullptr);

  struct constant * nameandtype_constant = &vm->current_frame->class_entry->class_file->constant_pool[fieldref_constant->fieldref.name_and_type_index - 1];
  #ifdef DEBUG
  assert(nameandtype_constant->tag == CONSTANT_NameAndType);
  #endif
  *field_descriptor_constant = &vm->current_frame->class_entry->class_file->constant_pool[nameandtype_constant->nameandtype.descriptor_index - 1];
  #ifdef DEBUG
  assert((*field_descriptor_constant)->tag == CONSTANT_Utf8);
  #endif
}