private void UnaryOperatorEasyOut(UnaryOperatorKind kind, BoundExpression operand, UnaryOperatorOverloadResolutionResult result)
{
var operandType = operand.Type;
if ((object)operandType == null)
{
return;
}
var easyOut = UnopEasyOut.OpKind(kind, operandType);
if (easyOut == UnaryOperatorKind.Error)
{
return;
}
UnaryOperatorSignature signature = this.Compilation.builtInOperators.GetSignature(easyOut);
Conversion?conversion = Conversions.FastClassifyConversion(operandType, signature.OperandType);
Debug.Assert(conversion.HasValue && conversion.Value.IsImplicit);
result.Results.Add(UnaryOperatorAnalysisResult.Applicable(signature, conversion.Value));
}
private static UnaryOperatorSignature?GetPointerOperation(UnaryOperatorKind kind, BoundExpression operand)
{
Debug.Assert(operand != null);
var pointerType = operand.Type as PointerTypeSymbol;
if ((object)pointerType == null)
{
return(null);
}
UnaryOperatorSignature?op = null;
switch (kind)
{
case UnaryOperatorKind.PostfixIncrement:
case UnaryOperatorKind.PostfixDecrement:
case UnaryOperatorKind.PrefixIncrement:
case UnaryOperatorKind.PrefixDecrement:
op = new UnaryOperatorSignature(kind | UnaryOperatorKind.Pointer, pointerType, pointerType);
break;
}
return(op);
}
public static UnaryOperatorAnalysisResult Inapplicable(UnaryOperatorSignature signature, Conversion conversion)
{
return(new UnaryOperatorAnalysisResult(OperatorAnalysisResultKind.Inapplicable, signature, conversion));
}
private UnaryOperatorAnalysisResult(OperatorAnalysisResultKind kind, UnaryOperatorSignature signature, Conversion conversion)
{
this.Kind = kind;
this.Signature = signature;
this.Conversion = conversion;
}
/// <summary>
/// If an element-wise binary operator returns a non-bool type, we will either:
/// - prepare a conversion to bool if one exists
/// - prepare a truth operator: op_false in the case of an equality (<c>a == b</c> will be lowered to <c>!((a == b).op_false)</c>) or op_true in the case of inequality,
/// with the conversion being used for its input.
/// </summary>
private void PrepareBoolConversionAndTruthOperator(TypeSymbol type, BinaryExpressionSyntax node, BinaryOperatorKind binaryOperator, DiagnosticBag diagnostics,
out Conversion conversionForBool, out UnaryOperatorSignature boolOperator)
{
// Is the operand implicitly convertible to bool?
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
TypeSymbol boolean = GetSpecialType(SpecialType.System_Boolean, diagnostics, node);
Conversion conversion = this.Conversions.ClassifyImplicitConversionFromType(type, boolean, ref useSiteDiagnostics);
diagnostics.Add(node, useSiteDiagnostics);
if (conversion.IsImplicit)
{
ReportDiagnosticsIfObsolete(diagnostics, conversion, node, hasBaseReceiver: false);
conversionForBool = conversion;
boolOperator = default;
return;
}
// It was not. Does it implement operator true (or false)?
UnaryOperatorKind boolOpKind;
switch (binaryOperator)
{
case BinaryOperatorKind.Equal:
boolOpKind = UnaryOperatorKind.False;
break;
case BinaryOperatorKind.NotEqual:
boolOpKind = UnaryOperatorKind.True;
break;
default:
throw ExceptionUtilities.UnexpectedValue(binaryOperator);
}
LookupResultKind resultKind;
ImmutableArray <MethodSymbol> originalUserDefinedOperators;
BoundExpression comparisonResult = new BoundTupleOperandPlaceholder(node, type);
UnaryOperatorAnalysisResult best = this.UnaryOperatorOverloadResolution(boolOpKind, comparisonResult, node, diagnostics, out resultKind, out originalUserDefinedOperators);
if (best.HasValue)
{
conversionForBool = best.Conversion;
boolOperator = best.Signature;
return;
}
// It did not. Give a "not convertible to bool" error.
GenerateImplicitConversionError(diagnostics, node, conversion, comparisonResult, boolean);
conversionForBool = Conversion.NoConversion;
boolOperator = default;
return;
}
private BetterResult BetterOperator(
UnaryOperatorSignature op1,
UnaryOperatorSignature op2,
BoundExpression operand,
ref CompoundUseSiteInfo <AssemblySymbol> useSiteInfo
)
{
// First we see if the conversion from the operand to one operand type is better than
// the conversion to the other.
BetterResult better = BetterConversionFromExpression(
operand,
op1.OperandType,
op2.OperandType,
ref useSiteInfo
);
if (better == BetterResult.Left || better == BetterResult.Right)
{
return(better);
}
// There was no better member on the basis of conversions. Go to the tiebreaking round.
// SPEC: In case the parameter type sequences P1, P2 and Q1, Q2 are equivalent -- that is, every Pi
// SPEC: has an identity conversion to the corresponding Qi -- the following tie-breaking rules
// SPEC: are applied:
if (Conversions.HasIdentityConversion(op1.OperandType, op2.OperandType))
{
// SPEC: If Mp has more specific parameter types than Mq then Mp is better than Mq.
// Under what circumstances can two unary operators with identical signatures be "more specific"
// than another? With a binary operator you could have C<T>.op+(C<T>, T) and C<T>.op+(C<T>, int).
// When doing overload resolution on C<int> + int, the latter is more specific. But with a unary
// operator, the sole operand *must* be the containing type or its nullable type. Therefore
// if there is an identity conversion, then the parameters really were identical. We therefore
// skip checking for specificity.
// SPEC: If one member is a non-lifted operator and the other is a lifted operator,
// SPEC: the non-lifted one is better.
bool lifted1 = op1.Kind.IsLifted();
bool lifted2 = op2.Kind.IsLifted();
if (lifted1 && !lifted2)
{
return(BetterResult.Right);
}
else if (!lifted1 && lifted2)
{
return(BetterResult.Left);
}
}
// Always prefer operators with val parameters over operators with in parameters:
if (op1.RefKind == RefKind.None && op2.RefKind == RefKind.In)
{
return(BetterResult.Left);
}
else if (op2.RefKind == RefKind.None && op1.RefKind == RefKind.In)
{
return(BetterResult.Right);
}
return(BetterResult.Neither);
}
private static UnaryOperatorSignature? GetPointerOperation(UnaryOperatorKind kind, BoundExpression operand)
{
Debug.Assert(operand != null);
var pointerType = operand.Type as PointerTypeSymbol;
if ((object)pointerType == null)
{
return null;
}
UnaryOperatorSignature? op = null;
switch (kind)
{
case UnaryOperatorKind.PostfixIncrement:
case UnaryOperatorKind.PostfixDecrement:
case UnaryOperatorKind.PrefixIncrement:
case UnaryOperatorKind.PrefixDecrement:
op = new UnaryOperatorSignature(kind | UnaryOperatorKind.Pointer, pointerType, pointerType);
break;
}
return op;
}
private BetterResult BetterOperator(UnaryOperatorSignature op1, UnaryOperatorSignature op2, BoundExpression operand, ref HashSet<DiagnosticInfo> useSiteDiagnostics)
{
// First we see if the conversion from the operand to one operand type is better than
// the conversion to the other.
BetterResult better = BetterConversionFromExpression(operand, op1.OperandType, op2.OperandType, ref useSiteDiagnostics);
if (better == BetterResult.Left || better == BetterResult.Right)
{
return better;
}
// There was no better member on the basis of conversions. Go to the tiebreaking round.
// SPEC: In case the parameter type sequences P1, P2 and Q1, Q2 are equivalent -- that is, every Pi
// SPEC: has an identity conversion to the corresponding Qi -- the following tie-breaking rules
// SPEC: are applied:
if (Conversions.HasIdentityConversion(op1.OperandType, op2.OperandType))
{
// SPEC: If Mp has more specific parameter types than Mq then Mp is better than Mq.
// Under what circumstances can two unary operators with identical signatures be "more specific"
// than another? With a binary operator you could have C<T>.op+(C<T>, T) and C<T>.op+(C<T>, int).
// When doing overload resolution on C<int> + int, the latter is more specific. But with a unary
// operator, the sole operand *must* be the containing type or its nullable type. Therefore
// if there is an identity conversion, then the parameters really were identical. We therefore
// skip checking for specificity.
// SPEC: If one member is a non-lifted operator and the other is a lifted operator,
// SPEC: the non-lifted one is better.
bool lifted1 = op1.Kind.IsLifted();
bool lifted2 = op2.Kind.IsLifted();
if (lifted1 && !lifted2)
{
return BetterResult.Right;
}
else if (!lifted1 && lifted2)
{
return BetterResult.Left;
}
}
return BetterResult.Neither;
}
private void PrepareBoolConversionAndTruthOperator(TypeSymbol type, BinaryExpressionSyntax node, BinaryOperatorKind binaryOperator, BindingDiagnosticBag diagnostics,
out BoundExpression conversionForBool, out BoundValuePlaceholder conversionForBoolPlaceholder, out UnaryOperatorSignature boolOperator)
{
// Is the operand implicitly convertible to bool?
CompoundUseSiteInfo <AssemblySymbol> useSiteInfo = GetNewCompoundUseSiteInfo(diagnostics);
TypeSymbol boolean = GetSpecialType(SpecialType.System_Boolean, diagnostics, node);
Conversion conversion = this.Conversions.ClassifyImplicitConversionFromType(type, boolean, ref useSiteInfo);
diagnostics.Add(node, useSiteInfo);
if (conversion.IsImplicit)
{
conversionForBoolPlaceholder = new BoundValuePlaceholder(node, type).MakeCompilerGenerated();
conversionForBool = CreateConversion(node, conversionForBoolPlaceholder, conversion, isCast: false, conversionGroupOpt: null, boolean, diagnostics);
boolOperator = default;
return;
}
// It was not. Does it implement operator true (or false)?
UnaryOperatorKind boolOpKind;
switch (binaryOperator)
{
case BinaryOperatorKind.Equal:
boolOpKind = UnaryOperatorKind.False;
break;
case BinaryOperatorKind.NotEqual:
boolOpKind = UnaryOperatorKind.True;
break;
default:
throw ExceptionUtilities.UnexpectedValue(binaryOperator);
}
LookupResultKind resultKind;
ImmutableArray <MethodSymbol> originalUserDefinedOperators;
BoundExpression comparisonResult = new BoundTupleOperandPlaceholder(node, type);
UnaryOperatorAnalysisResult best = this.UnaryOperatorOverloadResolution(boolOpKind, comparisonResult, node, diagnostics, out resultKind, out originalUserDefinedOperators);
if (best.HasValue)
{
conversionForBoolPlaceholder = new BoundValuePlaceholder(node, type).MakeCompilerGenerated();
conversionForBool = CreateConversion(node, conversionForBoolPlaceholder, best.Conversion, isCast: false, conversionGroupOpt: null, best.Signature.OperandType, diagnostics);
boolOperator = best.Signature;
return;
}
// It did not. Give a "not convertible to bool" error.
GenerateImplicitConversionError(diagnostics, node, conversion, comparisonResult, boolean);
conversionForBoolPlaceholder = null;
conversionForBool = null;
boolOperator = default;
return;
}
/// <summary>
/// Produce an element-wise comparison and logic to ensure the result is a bool type.
///
/// If an element-wise comparison doesn't return bool, then:
/// - if it is dynamic, we'll do `!(comparisonResult.false)` or `comparisonResult.true`
/// - if it implicitly converts to bool, we'll just do the conversion
/// - otherwise, we'll do `!(comparisonResult.false)` or `comparisonResult.true` (as we'd do for `if` or `while`)
/// </summary>
private BoundExpression RewriteTupleSingleOperator(TupleBinaryOperatorInfo.Single single,
BoundExpression left, BoundExpression right, TypeSymbol boolType, BinaryOperatorKind operatorKind)
{
if (single.Kind.IsDynamic())
{
// Produce
// !((left == right).op_false)
// (left != right).op_true
BoundExpression dynamicResult = _dynamicFactory.MakeDynamicBinaryOperator(single.Kind, left, right, isCompoundAssignment: false, _compilation.DynamicType).ToExpression();
if (operatorKind == BinaryOperatorKind.Equal)
{
return(_factory.Not(MakeUnaryOperator(UnaryOperatorKind.DynamicFalse, left.Syntax, method: null, dynamicResult, boolType)));
}
else
{
return(MakeUnaryOperator(UnaryOperatorKind.DynamicTrue, left.Syntax, method: null, dynamicResult, boolType));
}
}
if (left.IsLiteralNull() && right.IsLiteralNull())
{
// For `null == null` this is special-cased during initial binding
return(new BoundLiteral(left.Syntax, ConstantValue.Create(operatorKind == BinaryOperatorKind.Equal), boolType));
}
// We leave both operands in nullable-null conversions unconverted, MakeBinaryOperator has special for null-literal
bool isNullableNullConversion = single.Kind.OperandTypes() == BinaryOperatorKind.NullableNull;
BoundExpression convertedLeft = isNullableNullConversion
? left
: MakeConversionNode(left.Syntax, left, single.LeftConversion, single.LeftConvertedTypeOpt, @checked: false);
BoundExpression convertedRight = isNullableNullConversion
? right
: MakeConversionNode(right.Syntax, right, single.RightConversion, single.RightConvertedTypeOpt, @checked: false);
BoundExpression binary = MakeBinaryOperator(_factory.Syntax, single.Kind, convertedLeft, convertedRight, single.MethodSymbolOpt?.ReturnType ?? boolType, single.MethodSymbolOpt);
UnaryOperatorSignature boolOperator = single.BoolOperator;
Conversion boolConversion = single.ConversionForBool;
BoundExpression result;
if (boolOperator.Kind != UnaryOperatorKind.Error)
{
// Produce
// !((left == right).op_false)
// (left != right).op_true
BoundExpression convertedBinary = MakeConversionNode(_factory.Syntax, binary, boolConversion, boolOperator.OperandType, @checked: false);
Debug.Assert(boolOperator.ReturnType.SpecialType == SpecialType.System_Boolean);
result = MakeUnaryOperator(boolOperator.Kind, binary.Syntax, boolOperator.Method, convertedBinary, boolType);
if (operatorKind == BinaryOperatorKind.Equal)
{
result = _factory.Not(result);
}
}
else if (!boolConversion.IsIdentity)
{
// Produce
// (bool)(left == right)
// (bool)(left != right)
result = MakeConversionNode(_factory.Syntax, binary, boolConversion, boolType, @checked: false);
}
else
{
result = binary;
}
return(result);
}
public static UnaryOperatorAnalysisResult Inapplicable(UnaryOperatorSignature signature, Conversion conversion)
{
return new UnaryOperatorAnalysisResult(OperatorAnalysisResultKind.Inapplicable, signature, conversion);
}
private UnaryOperatorAnalysisResult(OperatorAnalysisResultKind kind, UnaryOperatorSignature signature, Conversion conversion)
{
this.Kind = kind;
this.Signature = signature;
this.Conversion = conversion;
}