public Expression ResolveBinaryOperator(ResolveContext rc, BinaryOperatorType op, Expression lhs, Expression rhs)
{
// V# 4.0 spec: §7.3.4 Binary operator overload resolution
string overloadableOperatorName = ResolveContext.GetOverloadableOperatorName(op);
if (overloadableOperatorName == null)
{
// Handle logical and/or exactly as bitwise and/or:
// - If the user overloads a bitwise operator, that implicitly creates the corresponding logical operator.
// - If both inputs are compile-time constants, it doesn't matter that we don't short-circuit.
// - If inputs aren't compile-time constants, we don't evaluate anything, so again it doesn't matter that we don't short-circuit
if (op == BinaryOperatorType.LogicalAnd)
{
overloadableOperatorName = ResolveContext.GetOverloadableOperatorName(BinaryOperatorType.BitwiseAnd);
}
else if (op == BinaryOperatorType.LogicalOr)
{
overloadableOperatorName = ResolveContext.GetOverloadableOperatorName(BinaryOperatorType.BitwiseOr);
}
else if (op == BinaryOperatorType.NullCoalescing)
{
// null coalescing operator is not overloadable and needs to be handled separately
return(ResolveNullCoalescingOperator(rc, lhs, rhs));
}
else
{
return(ErrorExpression.UnknownError);
}
}
// If the type is nullable, get the underlying type:
bool isNullable = NullableType.IsNullable(lhs.Type) || NullableType.IsNullable(rhs.Type);
IType lhsType = NullableType.GetUnderlyingType(lhs.Type);
IType rhsType = NullableType.GetUnderlyingType(rhs.Type);
// the operator is overloadable:
OverloadResolution userDefinedOperatorOR = rc.CreateOverloadResolution(new[] { lhs, rhs });
HashSet <IParameterizedMember> userOperatorCandidates = new HashSet <IParameterizedMember>();
userOperatorCandidates.UnionWith(rc.GetUserDefinedOperatorCandidates(lhsType, overloadableOperatorName));
userOperatorCandidates.UnionWith(rc.GetUserDefinedOperatorCandidates(rhsType, overloadableOperatorName));
foreach (var candidate in userOperatorCandidates)
{
userDefinedOperatorOR.AddCandidate(candidate);
}
if (userDefinedOperatorOR.FoundApplicableCandidate)
{
return(SetUserDefinedOperationInformations(rc, userDefinedOperatorOR));
}
if (lhsType.Kind == TypeKind.Null && rhsType.IsReferenceType == false ||
lhsType.IsReferenceType == false && rhsType.Kind == TypeKind.Null)
{
isNullable = true;
}
if (op == BinaryOperatorType.LeftShift || op == BinaryOperatorType.RightShift)
{
// special case: the shift operators allow "var x = null << null", producing int?.
if (lhsType.Kind == TypeKind.Null && rhsType.Kind == TypeKind.Null)
{
isNullable = true;
}
// for shift operators, do unary promotion independently on both arguments
lhs = UnaryNumericPromotion(rc, UnaryOperatorType.UnaryPlus, ref lhsType, isNullable, lhs);
rhs = UnaryNumericPromotion(rc, UnaryOperatorType.UnaryPlus, ref rhsType, isNullable, rhs);
}
else
{
bool allowNullableConstants = op == BinaryOperatorType.Equality || op == BinaryOperatorType.Inequality;
if (!BinaryNumericPromotion(rc, isNullable, ref lhs, ref rhs, allowNullableConstants))
{
return(new ErrorExpression(lhs.Type));
}
}
// re-read underlying types after numeric promotion
lhsType = NullableType.GetUnderlyingType(lhs.Type);
rhsType = NullableType.GetUnderlyingType(rhs.Type);
IEnumerable <VSharpOperators.OperatorMethod> methodGroup;
VSharpOperators operators = VSharpOperators.Get(rc.compilation);
switch (op)
{
case BinaryOperatorType.Multiply:
methodGroup = operators.MultiplicationOperators;
break;
case BinaryOperatorType.Division:
methodGroup = operators.DivisionOperators;
break;
case BinaryOperatorType.Modulus:
methodGroup = operators.RemainderOperators;
break;
case BinaryOperatorType.Addition:
methodGroup = operators.AdditionOperators;
{
if (lhsType.Kind == TypeKind.Enum)
{
// E operator +(E x, U y);
IType underlyingType = MakeNullable(rc, ResolveContext.GetEnumUnderlyingType(lhsType), isNullable);
if (rc.TryConvertEnum(ref rhs, underlyingType, ref isNullable, ref lhs))
{
return(HandleEnumOperator(rc, isNullable, lhsType, op, lhs, rhs));
}
}
if (rhsType.Kind == TypeKind.Enum)
{
// E operator +(U x, E y);
IType underlyingType = MakeNullable(rc, ResolveContext.GetEnumUnderlyingType(rhsType), isNullable);
if (rc.TryConvertEnum(ref lhs, underlyingType, ref isNullable, ref rhs))
{
return(HandleEnumOperator(rc, isNullable, rhsType, op, lhs, rhs));
}
}
if (lhsType.Kind == TypeKind.Delegate && rc.TryConvert(ref rhs, lhsType))
{
return(SetOperationInformations(rc, lhsType, lhs, op, rhs));
}
else if (rhsType.Kind == TypeKind.Delegate && rc.TryConvert(ref lhs, rhsType))
{
return(SetOperationInformations(rc, rhsType, lhs, op, rhs));
}
if (lhsType is PointerTypeSpec)
{
methodGroup = new[] {
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.Int32),
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.UInt32),
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.Int64),
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.UInt64)
};
}
else if (rhsType is PointerTypeSpec)
{
methodGroup = new[] {
PointerArithmeticOperator(rc, rhsType, KnownTypeCode.Int32, rhsType),
PointerArithmeticOperator(rc, rhsType, KnownTypeCode.UInt32, rhsType),
PointerArithmeticOperator(rc, rhsType, KnownTypeCode.Int64, rhsType),
PointerArithmeticOperator(rc, rhsType, KnownTypeCode.UInt64, rhsType)
};
}
if (lhsType.Kind == TypeKind.Null && rhsType.Kind == TypeKind.Null)
{
return(new ErrorExpression(SpecialTypeSpec.NullType));
}
}
break;
case BinaryOperatorType.Subtraction:
methodGroup = operators.SubtractionOperators;
{
if (lhsType.Kind == TypeKind.Enum)
{
// U operator –(E x, E y);
if (rc.TryConvertEnum(ref rhs, lhs.Type, ref isNullable, ref lhs, allowConversionFromConstantZero: false))
{
return(HandleEnumSubtraction(rc, isNullable, lhsType, lhs, rhs));
}
// E operator –(E x, U y);
IType underlyingType = MakeNullable(rc, ResolveContext.GetEnumUnderlyingType(lhsType), isNullable);
if (rc.TryConvertEnum(ref rhs, underlyingType, ref isNullable, ref lhs))
{
return(HandleEnumOperator(rc, isNullable, lhsType, op, lhs, rhs));
}
}
if (rhsType.Kind == TypeKind.Enum)
{
// U operator –(E x, E y);
if (rc.TryConvertEnum(ref lhs, rhs.Type, ref isNullable, ref rhs, allowConversionFromConstantZero: false))
{
return(HandleEnumSubtraction(rc, isNullable, rhsType, lhs, rhs));
}
// E operator -(U x, E y);
IType underlyingType = MakeNullable(rc, ResolveContext.GetEnumUnderlyingType(rhsType), isNullable);
if (rc.TryConvertEnum(ref lhs, underlyingType, ref isNullable, ref rhs))
{
return(HandleEnumOperator(rc, isNullable, rhsType, op, lhs, rhs));
}
}
if (lhsType.Kind == TypeKind.Delegate && rc.TryConvert(ref rhs, lhsType))
{
return(SetOperationInformations(rc, lhsType, lhs, op, rhs));
}
else if (rhsType.Kind == TypeKind.Delegate && rc.TryConvert(ref lhs, rhsType))
{
return(SetOperationInformations(rc, rhsType, lhs, op, rhs));
}
if (lhsType is PointerTypeSpec)
{
if (rhsType is PointerTypeSpec)
{
IType int64 = rc.compilation.FindType(KnownTypeCode.Int64);
if (lhsType.Equals(rhsType))
{
return(SetOperationInformations(rc, int64, lhs, op, rhs));
}
else
{
return(new ErrorExpression(int64));
}
}
methodGroup = new[] {
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.Int32),
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.UInt32),
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.Int64),
PointerArithmeticOperator(rc, lhsType, lhsType, KnownTypeCode.UInt64)
};
}
if (lhsType.Kind == TypeKind.Null && rhsType.Kind == TypeKind.Null)
{
return(new ErrorExpression(SpecialTypeSpec.NullType));
}
}
break;
case BinaryOperatorType.LeftShift:
methodGroup = operators.ShiftLeftOperators;
break;
case BinaryOperatorType.RightShift:
methodGroup = operators.ShiftRightOperators;
break;
case BinaryOperatorType.RotateRight:
methodGroup = operators.RotateRightOperators;
break;
case BinaryOperatorType.RotateLeft:
methodGroup = operators.RotateLeftOperators;
break;
case BinaryOperatorType.Equality:
case BinaryOperatorType.Inequality:
case BinaryOperatorType.LessThan:
case BinaryOperatorType.GreaterThan:
case BinaryOperatorType.LessThanOrEqual:
case BinaryOperatorType.GreaterThanOrEqual:
{
if (lhsType.Kind == TypeKind.Enum && rc.TryConvert(ref rhs, lhs.Type))
{
// bool operator op(E x, E y);
return(HandleEnumComparison(rc, op, lhsType, isNullable, lhs, rhs));
}
else if (rhsType.Kind == TypeKind.Enum && rc.TryConvert(ref lhs, rhs.Type))
{
// bool operator op(E x, E y);
return(HandleEnumComparison(rc, op, rhsType, isNullable, lhs, rhs));
}
else if (lhsType is PointerTypeSpec && rhsType is PointerTypeSpec)
{
return(SetOperationInformations(rc, rc.compilation.FindType(KnownTypeCode.Boolean), lhs, op, rhs));
}
if (op == BinaryOperatorType.Equality || op == BinaryOperatorType.Inequality)
{
if (lhsType.IsReferenceType == true && rhsType.IsReferenceType == true)
{
// If it's a reference comparison
if (op == BinaryOperatorType.Equality)
{
methodGroup = operators.ReferenceEqualityOperators;
}
else
{
methodGroup = operators.ReferenceInequalityOperators;
}
break;
}
else if (lhsType.Kind == TypeKind.Null && IsNullableTypeOrNonValueType(rhs.Type) ||
IsNullableTypeOrNonValueType(lhs.Type) && rhsType.Kind == TypeKind.Null)
{
// compare type parameter or nullable type with the null literal
return(SetOperationInformations(rc, rc.compilation.FindType(KnownTypeCode.Boolean), lhs, op, rhs));
}
}
switch (op)
{
case BinaryOperatorType.Equality:
methodGroup = operators.ValueEqualityOperators;
break;
case BinaryOperatorType.Inequality:
methodGroup = operators.ValueInequalityOperators;
break;
case BinaryOperatorType.LessThan:
methodGroup = operators.LessThanOperators;
break;
case BinaryOperatorType.GreaterThan:
methodGroup = operators.GreaterThanOperators;
break;
case BinaryOperatorType.LessThanOrEqual:
methodGroup = operators.LessThanOrEqualOperators;
break;
case BinaryOperatorType.GreaterThanOrEqual:
methodGroup = operators.GreaterThanOrEqualOperators;
break;
default:
throw new InvalidOperationException();
}
}
break;
case BinaryOperatorType.BitwiseAnd:
case BinaryOperatorType.BitwiseOr:
case BinaryOperatorType.ExclusiveOr:
{
if (lhsType.Kind == TypeKind.Enum)
{
// bool operator op(E x, E y);
if (rc.TryConvertEnum(ref rhs, lhs.Type, ref isNullable, ref lhs))
{
return(HandleEnumOperator(rc, isNullable, lhsType, op, lhs, rhs));
}
}
if (rhsType.Kind == TypeKind.Enum)
{
// bool operator op(E x, E y);
if (rc.TryConvertEnum(ref lhs, rhs.Type, ref isNullable, ref rhs))
{
return(HandleEnumOperator(rc, isNullable, rhsType, op, lhs, rhs));
}
}
switch (op)
{
case BinaryOperatorType.BitwiseAnd:
methodGroup = operators.BitwiseAndOperators;
break;
case BinaryOperatorType.BitwiseOr:
methodGroup = operators.BitwiseOrOperators;
break;
case BinaryOperatorType.ExclusiveOr:
methodGroup = operators.BitwiseXorOperators;
break;
default:
throw new InvalidOperationException();
}
}
break;
case BinaryOperatorType.LogicalAnd:
methodGroup = operators.LogicalAndOperators;
break;
case BinaryOperatorType.LogicalOr:
methodGroup = operators.LogicalOrOperators;
break;
default:
throw new InvalidOperationException();
}
OverloadResolution builtinOperatorOR = rc.CreateOverloadResolution(new[] { lhs, rhs });
foreach (var candidate in methodGroup)
{
builtinOperatorOR.AddCandidate(candidate);
}
VSharpOperators.BinaryOperatorMethod m = (VSharpOperators.BinaryOperatorMethod)builtinOperatorOR.BestCandidate;
IType resultType = m.ReturnType;
if (builtinOperatorOR.BestCandidateErrors != OverloadResolutionErrors.None)
{
// If there are any user-defined operators, prefer those over the built-in operators.
// It'll be a more informative error.
if (userDefinedOperatorOR.BestCandidate != null)
{
return(SetUserDefinedOperationInformations(rc, userDefinedOperatorOR));
}
else
{
return(new ErrorExpression(resultType));
}
}
else if (lhs.IsCompileTimeConstant && rhs.IsCompileTimeConstant && m.CanEvaluateAtCompileTime)
{
object val;
try
{
val = m.Invoke(rc, lhs.ConstantValue, rhs.ConstantValue);
}
catch (ArithmeticException)
{
return(new ErrorExpression(resultType));
}
return(Constant.CreateConstantFromValue(rc, resultType, val, loc));
}
else
{
lhs = rc.Convert(lhs, m.Parameters[0].Type, builtinOperatorOR.ArgumentConversions[0]);
rhs = rc.Convert(rhs, m.Parameters[1].Type, builtinOperatorOR.ArgumentConversions[1]);
return(SetOperationInformations(rc, resultType, lhs, op, rhs,
builtinOperatorOR.BestCandidate is OverloadResolution.ILiftedOperator));
}
}
