// Checks error conditions:
//   JVMTI_ERROR_INVALID_SLOT
//   JVMTI_ERROR_TYPE_MISMATCH
// Returns: 'true' - everything is Ok, 'false' - error code

bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {

  {- -------------------------------------------
  (1) (変数宣言など)
      ---------------------------------------- -}

      methodOop method_oop = jvf->method();

  {- -------------------------------------------
  (1) 
      ---------------------------------------- -}

      if (!method_oop->has_localvariable_table()) {
        // Just to check index boundaries
        jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
        if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
          _result = JVMTI_ERROR_INVALID_SLOT;
          return false;
        }
        return true;
      }

  {- -------------------------------------------
  (1) もし局所変数が1つもなければ, false をリターン.
      ---------------------------------------- -}

      jint num_entries = method_oop->localvariable_table_length();
      if (num_entries == 0) {
        _result = JVMTI_ERROR_INVALID_SLOT;
        return false;       // There are no slots
      }

  {- -------------------------------------------
  (1) 
      ---------------------------------------- -}

      int signature_idx = -1;
      int vf_bci = jvf->bci();
      LocalVariableTableElement* table = method_oop->localvariable_table_start();
      for (int i = 0; i < num_entries; i++) {
        int start_bci = table[i].start_bci;
        int end_bci = start_bci + table[i].length;

        // Here we assume that locations of LVT entries
        // with the same slot number cannot be overlapped
        if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
          signature_idx = (int) table[i].descriptor_cp_index;
          break;
        }
      }
      if (signature_idx == -1) {
        _result = JVMTI_ERROR_INVALID_SLOT;
        return false;       // Incorrect slot index
      }
      Symbol*   sign_sym  = method_oop->constants()->symbol_at(signature_idx);
      const char* signature = (const char *) sign_sym->as_utf8();
      BasicType slot_type = char2type(signature[0]);

      switch (slot_type) {
      case T_BYTE:
      case T_SHORT:
      case T_CHAR:
      case T_BOOLEAN:
        slot_type = T_INT;
        break;
      case T_ARRAY:
        slot_type = T_OBJECT;
        break;
      };
      if (_type != slot_type) {
        _result = JVMTI_ERROR_TYPE_MISMATCH;
        return false;
      }

      jobject jobj = _value.l;
      if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
        // Check that the jobject class matches the return type signature.
        JavaThread* cur_thread = JavaThread::current();
        HandleMark hm(cur_thread);

        Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
        NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
        KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
        NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));

        if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) {
          _result = JVMTI_ERROR_TYPE_MISMATCH;
          return false;
        }
      }
      return true;
    }