public override BoundNode VisitIsOperator(BoundIsOperator node)
{
BoundExpression rewrittenOperand = VisitExpression(node.Operand);
var rewrittenTargetType = (BoundTypeExpression)VisitTypeExpression(node.TargetType);
TypeSymbol rewrittenType = VisitType(node.Type);
return MakeIsOperator(node, node.Syntax, rewrittenOperand, rewrittenTargetType, node.Conversion, rewrittenType);
}
private BoundExpression VisitIsOperator(BoundIsOperator node)
{
var operand = node.Operand;
if ((object)operand.Type == null && operand.ConstantValue != null && operand.ConstantValue.IsNull)
{
operand = _bound.Null(_objectType);
}
return ExprFactory("TypeIs", Visit(operand), _bound.Typeof(node.TargetType.Type));
}
public override BoundNode VisitIsOperator(BoundIsOperator node)
{
BoundSpillSequence2 ss = null;
var operand = VisitExpression(ref ss, node.Operand);
return UpdateExpression(ss, node.Update(operand, node.TargetType, node.Conversion, node.Type));
}
private BoundExpression MakeIsOperator(
BoundIsOperator oldNode,
CSharpSyntaxNode syntax,
BoundExpression rewrittenOperand,
BoundTypeExpression rewrittenTargetType,
Conversion conversion,
TypeSymbol rewrittenType)
{
if (rewrittenOperand.Kind == BoundKind.MethodGroup)
{
var methodGroup = (BoundMethodGroup)rewrittenOperand;
BoundExpression receiver = methodGroup.ReceiverOpt;
if (receiver != null && receiver.Kind != BoundKind.ThisReference)
{
// possible side-effect
return RewriteConstantIsOperator(receiver.Syntax, receiver, ConstantValue.False, rewrittenType);
}
else
{
return MakeLiteral(syntax, ConstantValue.False, rewrittenType);
}
}
var operandType = rewrittenOperand.Type;
var targetType = rewrittenTargetType.Type;
Debug.Assert((object)operandType != null || rewrittenOperand.ConstantValue.IsNull);
Debug.Assert((object)targetType != null);
// TODO: Handle dynamic operand type and target type
if (!inExpressionLambda)
{
ConstantValue constantValue = Binder.GetIsOperatorConstantResult(operandType, targetType, conversion.Kind, rewrittenOperand.ConstantValue);
if (constantValue != null)
{
return RewriteConstantIsOperator(syntax, rewrittenOperand, constantValue, rewrittenType);
}
else if (conversion.IsImplicit)
{
// operand is a reference type with bound identity or implicit conversion
// We can replace the "is" instruction with a null check
Debug.Assert((object)operandType != null);
if (operandType.TypeKind == TypeKind.TypeParameter)
{
// We need to box the type parameter even if it is a known
// reference type to ensure there are no verifier errors
rewrittenOperand = MakeConversion(
syntax: rewrittenOperand.Syntax,
rewrittenOperand: rewrittenOperand,
conversionKind: ConversionKind.Boxing,
rewrittenType: compilation.GetSpecialType(SpecialType.System_Object),
@checked: false);
}
return MakeNullCheck(syntax, rewrittenOperand, BinaryOperatorKind.NotEqual);
}
}
return oldNode.Update(rewrittenOperand, rewrittenTargetType, conversion, rewrittenType);
}
public override BoundNode VisitIsOperator(BoundIsOperator node)
{
BoundExpression operand = (BoundExpression)this.Visit(node.Operand);
BoundTypeExpression targetType = (BoundTypeExpression)this.Visit(node.TargetType);
TypeSymbol type = this.VisitType(node.Type);
if (operand.Kind != BoundKind.SpillSequence)
{
return node.Update(operand, targetType, node.Conversion, type);
}
var spill = (BoundSpillSequence)operand;
var newIsOperator = node.Update(spill.Value, targetType, node.Conversion, type);
return RewriteSpillSequence(spill, newIsOperator);
}
