public TypeBinding resolveType(BlockScope scope) {
    // compute a new constant if the cast is effective

    this.constant = Constant.NotAConstant;
    this.implicitConversion = TypeIds.T_undefined;

    boolean exprContainCast = false;

    TypeBinding castType = this.resolvedType = this.type.resolveType(scope);
    if (scope.compilerOptions().sourceLevel >= ClassFileConstants.JDK1_8) {
      this.expression.setExpressionContext(CASTING_CONTEXT);
      if (this.expression instanceof FunctionalExpression) {
        this.expression.setExpectedType(this.resolvedType);
        this.bits |= ASTNode.DisableUnnecessaryCastCheck;
      }
    }
    if (this.expression instanceof CastExpression) {
      this.expression.bits |= ASTNode.DisableUnnecessaryCastCheck;
      exprContainCast = true;
    }
    TypeBinding expressionType = this.expression.resolveType(scope);
    if (this.expression instanceof MessageSend) {
      MessageSend messageSend = (MessageSend) this.expression;
      MethodBinding methodBinding = messageSend.binding;
      if (methodBinding != null && methodBinding.isPolymorphic()) {
        messageSend.binding =
            scope
                .environment()
                .updatePolymorphicMethodReturnType(
                    (PolymorphicMethodBinding) methodBinding, castType);
        if (TypeBinding.notEquals(expressionType, castType)) {
          expressionType = castType;
          this.bits |= ASTNode.DisableUnnecessaryCastCheck;
        }
      }
    }
    if (castType != null) {
      if (expressionType != null) {

        boolean nullAnnotationMismatch =
            scope.compilerOptions().isAnnotationBasedNullAnalysisEnabled
                && NullAnnotationMatching.analyse(castType, expressionType, -1).isAnyMismatch();

        boolean isLegal =
            checkCastTypesCompatibility(scope, castType, expressionType, this.expression);
        if (isLegal) {
          this.expression.computeConversion(scope, castType, expressionType);
          if ((this.bits & ASTNode.UnsafeCast) != 0) { // unsafe cast
            if (scope.compilerOptions().reportUnavoidableGenericTypeProblems
                || !(expressionType.isRawType()
                    && this.expression.forcedToBeRaw(scope.referenceContext()))) {
              scope.problemReporter().unsafeCast(this, scope);
            }
          } else if (nullAnnotationMismatch) {
            // report null annotation issue at medium priority
            scope.problemReporter().unsafeNullnessCast(this, scope);
          } else {
            if (castType.isRawType()
                && scope.compilerOptions().getSeverity(CompilerOptions.RawTypeReference)
                    != ProblemSeverities.Ignore) {
              scope.problemReporter().rawTypeReference(this.type, castType);
            }
            if ((this.bits & (ASTNode.UnnecessaryCast | ASTNode.DisableUnnecessaryCastCheck))
                == ASTNode.UnnecessaryCast) { // unnecessary cast
              if (!isIndirectlyUsed()) // used for generic type inference or boxing ?
              scope.problemReporter().unnecessaryCast(this);
            }
          }
        } else { // illegal cast
          if ((castType.tagBits & TagBits.HasMissingType) == 0) { // no complaint if secondary error
            scope.problemReporter().typeCastError(this, castType, expressionType);
          }
          this.bits |= ASTNode.DisableUnnecessaryCastCheck; // disable further secondary diagnosis
        }
      }
      this.resolvedType =
          castType.capture(
              scope,
              this.type.sourceStart,
              this.type.sourceEnd); // make it unique, a cast expression shares source end with the
      // expression.
      if (exprContainCast) {
        checkNeedForCastCast(scope, this);
      }
    }
    return this.resolvedType;
  }
  private static void checkAlternateBinding(
      BlockScope scope,
      Expression receiver,
      TypeBinding receiverType,
      MethodBinding binding,
      Expression[] arguments,
      TypeBinding[] originalArgumentTypes,
      TypeBinding[] alternateArgumentTypes,
      final InvocationSite invocationSite) {
    InvocationSite fakeInvocationSite =
        new InvocationSite() {
          public TypeBinding[] genericTypeArguments() {
            return null;
          }

          public boolean isSuperAccess() {
            return invocationSite.isSuperAccess();
          }

          public boolean isTypeAccess() {
            return invocationSite.isTypeAccess();
          }

          public void setActualReceiverType(ReferenceBinding actualReceiverType) {
            /* ignore */
          }

          public void setDepth(int depth) {
            /* ignore */
          }

          public void setFieldIndex(int depth) {
            /* ignore */
          }

          public int sourceStart() {
            return 0;
          }

          public int sourceEnd() {
            return 0;
          }

          public TypeBinding invocationTargetType() {
            return invocationSite.invocationTargetType();
          }

          public boolean receiverIsImplicitThis() {
            return invocationSite.receiverIsImplicitThis();
          }

          public InferenceContext18 freshInferenceContext(Scope someScope) {
            return invocationSite.freshInferenceContext(someScope);
          }

          public ExpressionContext getExpressionContext() {
            return invocationSite.getExpressionContext();
          }

          public boolean isQualifiedSuper() {
            return invocationSite.isQualifiedSuper();
          }

          public boolean checkingPotentialCompatibility() {
            return false;
          }

          public void acceptPotentiallyCompatibleMethods(MethodBinding[] methods) {
            /* ignore */
          }
        };
    MethodBinding bindingIfNoCast;
    if (binding.isConstructor()) {
      bindingIfNoCast =
          scope.getConstructor(
              (ReferenceBinding) receiverType, alternateArgumentTypes, fakeInvocationSite);
    } else {
      bindingIfNoCast =
          receiver.isImplicitThis()
              ? scope.getImplicitMethod(
                  binding.selector, alternateArgumentTypes, fakeInvocationSite)
              : scope.getMethod(
                  receiverType, binding.selector, alternateArgumentTypes, fakeInvocationSite);
    }
    if (bindingIfNoCast == binding) {
      int argumentLength = originalArgumentTypes.length;
      if (binding.isVarargs()) {
        int paramLength = binding.parameters.length;
        if (paramLength == argumentLength) {
          int varargsIndex = paramLength - 1;
          ArrayBinding varargsType = (ArrayBinding) binding.parameters[varargsIndex];
          TypeBinding lastArgType = alternateArgumentTypes[varargsIndex];
          // originalType may be compatible already, but cast mandated
          // to clarify between varargs/non-varargs call
          if (varargsType.dimensions != lastArgType.dimensions()) {
            return;
          }
          if (lastArgType.isCompatibleWith(varargsType.elementsType())
              && lastArgType.isCompatibleWith(varargsType)) {
            return;
          }
        }
      }
      for (int i = 0; i < argumentLength; i++) {
        if (TypeBinding.notEquals(originalArgumentTypes[i], alternateArgumentTypes[i])
        /*&& !originalArgumentTypes[i].needsUncheckedConversion(alternateArgumentTypes[i])*/ ) {
          scope.problemReporter().unnecessaryCast((CastExpression) arguments[i]);
        }
      }
    }
  }