private BoundTupleLiteral DeconstructVariablesAsTuple(SyntaxNode syntax, ArrayBuilder <DeconstructionVariable> variables)
{
int count = variables.Count;
var valuesBuilder = ArrayBuilder <BoundExpression> .GetInstance(count);
var typesBuilder = ArrayBuilder <TypeSymbol> .GetInstance(count);
var locationsBuilder = ArrayBuilder <Location> .GetInstance(count);
foreach (var variable in variables)
{
if (variable.HasNestedVariables)
{
var nestedTuple = DeconstructVariablesAsTuple(variable.Syntax, variable.NestedVariables);
valuesBuilder.Add(nestedTuple);
typesBuilder.Add(nestedTuple.Type);
}
else
{
var single = variable.Single;
valuesBuilder.Add(single);
typesBuilder.Add(single.Type);
}
locationsBuilder.Add(variable.Syntax.Location);
}
// MakeDeconstructionConstructionStep constructs the final tuple type and checks constraints already.
var type = TupleTypeSymbol.Create(syntax.Location,
typesBuilder.ToImmutableAndFree(), locationsBuilder.ToImmutableAndFree(),
elementNames: default(ImmutableArray <string>), compilation: this.Compilation, shouldCheckConstraints: false);
return(new BoundTupleLiteral(syntax: syntax, argumentNamesOpt: default(ImmutableArray <string>),
arguments: valuesBuilder.ToImmutableAndFree(), type: type));
}
private void AccessTupleFields(BoundDeconstructionAssignmentOperator node, BoundDeconstructionDeconstructStep deconstruction, ArrayBuilder <LocalSymbol> temps, ArrayBuilder <BoundExpression> stores, ArrayBuilder <BoundValuePlaceholderBase> placeholders)
{
var target = PlaceholderReplacement(deconstruction.InputPlaceholder);
var tupleType = target.Type.IsTupleType ? target.Type : TupleTypeSymbol.Create((NamedTypeSymbol)target.Type);
var tupleElementTypes = tupleType.TupleElementTypes;
var numElements = tupleElementTypes.Length;
SyntaxNode syntax = node.Syntax;
// save the target as we need to access it multiple times
BoundAssignmentOperator assignmentToTemp;
BoundLocal savedTuple = _factory.StoreToTemp(target, out assignmentToTemp);
stores.Add(assignmentToTemp);
temps.Add(savedTuple.LocalSymbol);
// list the tuple fields accessors
var fields = tupleType.TupleElements;
for (int i = 0; i < numElements; i++)
{
var field = fields[i];
DiagnosticInfo useSiteInfo = field.GetUseSiteDiagnostic();
if ((object)useSiteInfo != null && useSiteInfo.Severity == DiagnosticSeverity.Error)
{
Symbol.ReportUseSiteDiagnostic(useSiteInfo, _diagnostics, syntax.Location);
}
var fieldAccess = MakeTupleFieldAccess(syntax, field, savedTuple, null, LookupResultKind.Empty);
AddPlaceholderReplacement(deconstruction.OutputPlaceholders[i], fieldAccess);
placeholders.Add(deconstruction.OutputPlaceholders[i]);
}
}
private BoundTupleLiteral DeconstructionVariablesAsTuple(CSharpSyntaxNode syntax, ArrayBuilder <DeconstructionVariable> variables, DiagnosticBag diagnostics, bool hasErrors)
{
int count = variables.Count;
var valuesBuilder = ArrayBuilder <BoundExpression> .GetInstance(count);
var typesBuilder = ArrayBuilder <TypeSymbol> .GetInstance(count);
var locationsBuilder = ArrayBuilder <Location> .GetInstance(count);
foreach (var variable in variables)
{
if (variable.HasNestedVariables)
{
var nestedTuple = DeconstructionVariablesAsTuple(variable.Syntax, variable.NestedVariables, diagnostics, hasErrors);
valuesBuilder.Add(nestedTuple);
typesBuilder.Add(nestedTuple.Type);
}
else
{
var single = variable.Single;
valuesBuilder.Add(single);
typesBuilder.Add(single.Type);
}
locationsBuilder.Add(variable.Syntax.Location);
}
var type = TupleTypeSymbol.Create(syntax.Location,
typesBuilder.ToImmutableAndFree(), locationsBuilder.ToImmutableAndFree(),
elementNames: default(ImmutableArray <string>), compilation: this.Compilation,
shouldCheckConstraints: !hasErrors, syntax: syntax, diagnostics: hasErrors ? null : diagnostics);
return(new BoundTupleLiteral(syntax: syntax, argumentNamesOpt: default(ImmutableArray <string>),
arguments: valuesBuilder.ToImmutableAndFree(), type: type));
}
private NamedTypeSymbol DecodeNamedType(NamedTypeSymbol type)
{
// First decode the type arguments
var typeArgs = type.TypeArgumentsNoUseSiteDiagnostics;
var decodedArgs = DecodeTypeArguments(typeArgs);
NamedTypeSymbol decodedType = type;
// Now check the container
NamedTypeSymbol containingType = type.ContainingType;
NamedTypeSymbol decodedContainingType;
if ((object)containingType != null && containingType.IsGenericType)
{
decodedContainingType = DecodeNamedType(containingType);
Debug.Assert(decodedContainingType.IsGenericType);
}
else
{
decodedContainingType = containingType;
}
// Replace the type if necessary
var containerChanged = !ReferenceEquals(decodedContainingType, containingType);
var typeArgsChanged = typeArgs != decodedArgs;
if (typeArgsChanged || containerChanged)
{
var newTypeArgs = type.HasTypeArgumentsCustomModifiers
? decodedArgs.SelectAsArray((t, i, m) => new TypeWithModifiers(t, m.GetTypeArgumentCustomModifiers(i)), type)
: decodedArgs.SelectAsArray(TypeMap.TypeSymbolAsTypeWithModifiers);
if (containerChanged)
{
decodedType = decodedType.OriginalDefinition.AsMember(decodedContainingType);
// If the type is nested, e.g. Outer<T>.Inner<V>, then Inner is definitely
// not a tuple, since we know all tuple-compatible types (System.ValueTuple)
// are not nested types. Thus, it is safe to return without checking if
// Inner is a tuple.
return(decodedType.ConstructIfGeneric(newTypeArgs));
}
decodedType = type.ConstructedFrom.Construct(newTypeArgs, unbound: false);
}
// Now decode into a tuple, if it is one
int tupleCardinality;
if (decodedType.IsTupleCompatible(out tupleCardinality))
{
var elementNames = EatElementNamesIfAvailable(tupleCardinality);
Debug.Assert(elementNames.IsDefault || elementNames.Length == tupleCardinality);
decodedType = TupleTypeSymbol.Create(decodedType, elementNames);
}
return(decodedType);
}
/// <summary>
/// For cases where the RHS of a deconstruction-declaration is a tuple literal, we merge type information from both the LHS and RHS.
/// For cases where the RHS of a deconstruction-assignment is a tuple literal, the type information from the LHS determines the merged type, since all variables have a type.
/// Returns null if a merged tuple type could not be fabricated.
/// </summary>
private static TypeSymbol MakeMergedTupleType(ArrayBuilder <DeconstructionVariable> lhsVariables, BoundTupleLiteral rhsLiteral, CSharpSyntaxNode syntax, CSharpCompilation compilation, DiagnosticBag diagnostics)
{
int leftLength = lhsVariables.Count;
int rightLength = rhsLiteral.Arguments.Length;
var typesBuilder = ArrayBuilder <TypeSymbol> .GetInstance(leftLength);
for (int i = 0; i < rightLength; i++)
{
BoundExpression element = rhsLiteral.Arguments[i];
TypeSymbol mergedType = element.Type;
if (i < leftLength)
{
var variable = lhsVariables[i];
if (variable.HasNestedVariables)
{
if (element.Kind == BoundKind.TupleLiteral)
{
// (variables) on the left and (elements) on the right
mergedType = MakeMergedTupleType(variable.NestedVariables, (BoundTupleLiteral)element, syntax, compilation, diagnostics);
}
else if ((object)mergedType == null)
{
// (variables) on the left and null on the right
Error(diagnostics, ErrorCode.ERR_DeconstructRequiresExpression, element.Syntax);
}
}
else
{
if ((object)variable.Single.Type != null)
{
// typed-variable on the left
mergedType = variable.Single.Type;
}
}
}
else
{
if ((object)mergedType == null)
{
// a typeless element on the right, matching no variable on the left
Error(diagnostics, ErrorCode.ERR_DeconstructRequiresExpression, element.Syntax);
}
}
typesBuilder.Add(mergedType);
}
if (typesBuilder.Any(t => t == null))
{
typesBuilder.Free();
return(null);
}
return(TupleTypeSymbol.Create(locationOpt: null, elementTypes: typesBuilder.ToImmutableAndFree(), elementLocations: default(ImmutableArray <Location>),
elementNames: default(ImmutableArray <string>), compilation: compilation, diagnostics: diagnostics));
}
private NamedTypeSymbol TransformTupleType(NamedTypeSymbol tupleType, bool isContaining)
{
Debug.Assert(tupleType.IsTupleType);
var underlying = tupleType.TupleUnderlyingType;
var transformedUnderlying = TransformNamedType(underlying, isContaining);
return(TupleTypeSymbol.Create(transformedUnderlying, tupleType.TupleElementNames));
}
private BoundTupleLiteral DeconstructionVariablesAsTuple(CSharpSyntaxNode syntax, ArrayBuilder <DeconstructionVariable> variables, DiagnosticBag diagnostics, bool hasErrors)
{
int count = variables.Count;
var valuesBuilder = ArrayBuilder <BoundExpression> .GetInstance(count);
var typesBuilder = ArrayBuilder <TypeSymbol> .GetInstance(count);
var locationsBuilder = ArrayBuilder <Location> .GetInstance(count);
var namesBuilder = ArrayBuilder <string> .GetInstance(count);
foreach (var variable in variables)
{
if (variable.HasNestedVariables)
{
var nestedTuple = DeconstructionVariablesAsTuple(variable.Syntax, variable.NestedVariables, diagnostics, hasErrors);
valuesBuilder.Add(nestedTuple);
typesBuilder.Add(nestedTuple.Type);
namesBuilder.Add(null);
}
else
{
var single = variable.Single;
valuesBuilder.Add(single);
typesBuilder.Add(single.Type);
namesBuilder.Add(ExtractDeconstructResultElementName(single));
}
locationsBuilder.Add(variable.Syntax.Location);
}
var uniqueFieldNames = PooledHashSet <string> .GetInstance();
RemoveDuplicateInferredTupleNames(namesBuilder, uniqueFieldNames);
uniqueFieldNames.Free();
ImmutableArray <string> tupleNames = namesBuilder.ToImmutableAndFree();
bool disallowInferredNames = this.Compilation.LanguageVersion.DisallowInferredTupleElementNames();
var inferredPositions = tupleNames.SelectAsArray(n => n != null);
var type = TupleTypeSymbol.Create(syntax.Location,
typesBuilder.ToImmutableAndFree(), locationsBuilder.ToImmutableAndFree(),
tupleNames, this.Compilation,
shouldCheckConstraints: !hasErrors,
errorPositions: disallowInferredNames ? inferredPositions : default(ImmutableArray <bool>),
syntax: syntax, diagnostics: hasErrors ? null : diagnostics);
// Always track the inferred positions in the bound node, so that conversions don't produce a warning
// for "dropped names" on tuple literal when the name was inferred.
return(new BoundTupleLiteral(syntax, tupleNames, inferredPositions, arguments: valuesBuilder.ToImmutableAndFree(), type: type));
}
/// <summary>
/// This method recurses through leftTargets, right and conversion at the same time.
/// As it does, it collects side-effects into the proper buckets (init, deconstructions, conversions, assignments).
///
/// The side-effects from the right initially go into the init bucket. But once we started drilling into a Deconstruct
/// invocation, subsequent side-effects from the right go into the deconstructions bucket (otherwise they would
/// be evaluated out of order).
/// </summary>
private BoundTupleLiteral ApplyDeconstructionConversion(ArrayBuilder <Binder.DeconstructionVariable> leftTargets,
BoundExpression right, Conversion conversion, ArrayBuilder <LocalSymbol> temps, DeconstructionSideEffects effects,
bool inInit)
{
Debug.Assert(conversion.Kind == ConversionKind.Deconstruction);
ImmutableArray <BoundExpression> rightParts = GetRightParts(right, conversion, ref temps, effects, ref inInit);
ImmutableArray <Conversion> underlyingConversions = conversion.UnderlyingConversions;
Debug.Assert(!underlyingConversions.IsDefault);
Debug.Assert(leftTargets.Count == rightParts.Length && leftTargets.Count == conversion.UnderlyingConversions.Length);
var builder = ArrayBuilder <BoundExpression> .GetInstance(leftTargets.Count);
for (int i = 0; i < leftTargets.Count; i++)
{
BoundExpression resultPart;
if (leftTargets[i].HasNestedVariables)
{
resultPart = ApplyDeconstructionConversion(leftTargets[i].NestedVariables, rightParts[i],
underlyingConversions[i], temps, effects, inInit);
}
else
{
var rightPart = rightParts[i];
if (inInit)
{
rightPart = EvaluateSideEffectingArgumentToTemp(VisitExpression(rightPart), inInit ? effects.init : effects.deconstructions, ref temps);
}
BoundExpression leftTarget = leftTargets[i].Single;
resultPart = EvaluateConversionToTemp(rightPart, underlyingConversions[i], leftTarget.Type, temps,
effects.conversions);
if (leftTarget.Kind != BoundKind.DiscardExpression)
{
effects.assignments.Add(MakeAssignmentOperator(resultPart.Syntax, leftTarget, resultPart, leftTarget.Type,
used: true, isChecked: false, isCompoundAssignment: false));
}
}
builder.Add(resultPart);
}
var tupleType = TupleTypeSymbol.Create(locationOpt: null, elementTypes: builder.SelectAsArray(e => e.Type),
elementLocations: default(ImmutableArray <Location>), elementNames: default(ImmutableArray <string>),
compilation: _compilation, shouldCheckConstraints: false);
return(new BoundTupleLiteral(right.Syntax, default(ImmutableArray <string>), builder.ToImmutableAndFree(), tupleType));
}
private NamedTypeSymbol TransformTupleType(NamedTypeSymbol tupleType, bool isContaining)
{
Debug.Assert(tupleType.IsTupleType);
var underlying = tupleType.TupleUnderlyingType;
var transformedUnderlying = TransformNamedType(underlying, isContaining);
if ((object)transformedUnderlying == null)
{
// Bail, something is wrong with the flags.
// the dynamic transformation should be ignored.
return(null);
}
return(TupleTypeSymbol.Create(transformedUnderlying, tupleType.TupleElementNames));
}
private BoundTupleLiteral DeconstructionVariablesAsTuple(CSharpSyntaxNode syntax, ArrayBuilder <DeconstructionVariable> variables,
DiagnosticBag diagnostics, bool ignoreDiagnosticsFromTuple)
{
int count = variables.Count;
var valuesBuilder = ArrayBuilder <BoundExpression> .GetInstance(count);
var typesBuilder = ArrayBuilder <TypeSymbol> .GetInstance(count);
var locationsBuilder = ArrayBuilder <Location> .GetInstance(count);
var namesBuilder = ArrayBuilder <string> .GetInstance(count);
foreach (var variable in variables)
{
if (variable.HasNestedVariables)
{
var nestedTuple = DeconstructionVariablesAsTuple(variable.Syntax, variable.NestedVariables, diagnostics, ignoreDiagnosticsFromTuple);
valuesBuilder.Add(nestedTuple);
typesBuilder.Add(nestedTuple.Type);
namesBuilder.Add(null);
}
else
{
var single = variable.Single;
valuesBuilder.Add(single);
typesBuilder.Add(single.Type);
namesBuilder.Add(ExtractDeconstructResultElementName(single));
}
locationsBuilder.Add(variable.Syntax.Location);
}
var uniqueFieldNames = PooledHashSet <string> .GetInstance();
RemoveDuplicateInferredTupleNames(namesBuilder, uniqueFieldNames);
uniqueFieldNames.Free();
ImmutableArray <string> tupleNames = namesBuilder.ToImmutableAndFree();
bool disallowInferredNames = this.Compilation.LanguageVersion.DisallowInferredTupleElementNames();
var inferredPositions = tupleNames.SelectAsArray(n => n != null);
var type = TupleTypeSymbol.Create(syntax.Location,
typesBuilder.ToImmutableAndFree(), locationsBuilder.ToImmutableAndFree(),
tupleNames, this.Compilation,
shouldCheckConstraints: !ignoreDiagnosticsFromTuple,
errorPositions: disallowInferredNames ? inferredPositions : default,
private BoundDeconstructionConstructionStep MakeDeconstructionConstructionStep(CSharpSyntaxNode node, DiagnosticBag diagnostics,
ImmutableArray <BoundDeconstructValuePlaceholder> constructionInputs)
{
var tuple = TupleTypeSymbol.Create(locationOpt: null,
elementTypes: constructionInputs.SelectAsArray(e => e.Type),
elementLocations: default(ImmutableArray <Location>),
elementNames: default(ImmutableArray <string>),
compilation: Compilation,
diagnostics: diagnostics,
syntax: node);
var outputPlaceholder = new BoundDeconstructValuePlaceholder(node, tuple)
{
WasCompilerGenerated = true
};
BoundExpression construction = new BoundTupleLiteral(node, default(ImmutableArray <string>), constructionInputs.CastArray <BoundExpression>(), tuple);
return(new BoundDeconstructionConstructionStep(node, construction, outputPlaceholder));
}
/// <summary>
/// For cases where the RHS of a deconstruction-declaration is a tuple literal, we merge type information from both the LHS and RHS.
/// For cases where the RHS of a deconstruction-assignment is a tuple literal, the type information from the LHS determines the merged type, since all variables have a type.
/// Returns null if a merged tuple type could not be fabricated.
/// </summary>
private static TypeSymbol MakeMergedTupleType(ArrayBuilder <DeconstructionVariable> lhsVariables, BoundTupleLiteral rhsLiteral, CSharpSyntaxNode syntax, CSharpCompilation compilation, DiagnosticBag diagnostics)
{
int leftLength = lhsVariables.Count;
int rightLength = rhsLiteral.Arguments.Length;
var typesBuilder = ArrayBuilder <TypeSymbol> .GetInstance(leftLength);
var locationsBuilder = ArrayBuilder <Location> .GetInstance(leftLength);
for (int i = 0; i < rightLength; i++)
{
BoundExpression element = rhsLiteral.Arguments[i];
TypeSymbol mergedType = element.Type;
if (i < leftLength)
{
var variable = lhsVariables[i];
if (variable.HasNestedVariables)
{
if (element.Kind == BoundKind.TupleLiteral)
{
// (variables) on the left and (elements) on the right
mergedType = MakeMergedTupleType(variable.NestedVariables, (BoundTupleLiteral)element, syntax, compilation, diagnostics);
}
else if ((object)mergedType == null)
{
// (variables) on the left and null on the right
Error(diagnostics, ErrorCode.ERR_DeconstructRequiresExpression, element.Syntax);
}
}
else
{
if ((object)variable.Single.Type != null)
{
// typed-variable on the left
mergedType = variable.Single.Type;
}
}
}
else
{
if ((object)mergedType == null)
{
// a typeless element on the right, matching no variable on the left
Error(diagnostics, ErrorCode.ERR_DeconstructRequiresExpression, element.Syntax);
}
}
typesBuilder.Add(mergedType);
locationsBuilder.Add(element.Syntax.Location);
}
if (typesBuilder.Any(t => t == null))
{
typesBuilder.Free();
locationsBuilder.Free();
return(null);
}
// The tuple created here is not identical to the one created by
// DeconstructionVariablesAsTuple. It represents a smaller
// tree of types used for figuring out natural types in tuple literal.
return(TupleTypeSymbol.Create(
locationOpt: null,
elementTypes: typesBuilder.ToImmutableAndFree(),
elementLocations: locationsBuilder.ToImmutableAndFree(),
elementNames: default(ImmutableArray <string>),
compilation: compilation,
diagnostics: diagnostics,
shouldCheckConstraints: true,
errorPositions: default(ImmutableArray <bool>),
syntax: syntax));
}
public override Symbol VisitNamedType(NamedTypeSymbol sourceType)
{
var originalDef = sourceType.OriginalDefinition;
if ((object)originalDef != (object)sourceType)
{
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
var typeArguments = sourceType.GetAllTypeArguments(ref useSiteDiagnostics);
var otherDef = (NamedTypeSymbol)this.Visit(originalDef);
if ((object)otherDef == null)
{
return(null);
}
var otherTypeParameters = otherDef.GetAllTypeParameters();
bool translationFailed = false;
var otherTypeArguments = typeArguments.SelectAsArray((t, v) =>
{
var newType = (TypeSymbol)v.Visit(t.Type);
if ((object)newType == null)
{
// For a newly added type, there is no match in the previous generation, so it could be null.
translationFailed = true;
newType = t.Type;
}
return(new TypeWithModifiers(newType, v.VisitCustomModifiers(t.CustomModifiers)));
}, this);
if (translationFailed)
{
// For a newly added type, there is no match in the previous generation, so it could be null.
return(null);
}
// TODO: LambdaFrame has alpha renamed type parameters, should we rather fix that?
var typeMap = new TypeMap(otherTypeParameters, otherTypeArguments, allowAlpha: true);
return(typeMap.SubstituteNamedType(otherDef));
}
else if (sourceType.IsTupleType)
{
var otherDef = (NamedTypeSymbol)this.Visit(sourceType.TupleUnderlyingType);
if ((object)otherDef == null || !otherDef.IsTupleOrCompatibleWithTupleOfCardinality(sourceType.TupleElementTypes.Length))
{
return(null);
}
return(TupleTypeSymbol.Create(otherDef, sourceType.TupleElementNames));
}
Debug.Assert(sourceType.IsDefinition);
var otherContainer = this.Visit(sourceType.ContainingSymbol);
// Containing type will be missing from other assembly
// if the type was added in the (newer) source assembly.
if ((object)otherContainer == null)
{
return(null);
}
switch (otherContainer.Kind)
{
case SymbolKind.Namespace:
if (AnonymousTypeManager.IsAnonymousTypeTemplate(sourceType))
{
Debug.Assert((object)otherContainer == (object)_otherAssembly.GlobalNamespace);
AnonymousTypeValue value;
this.TryFindAnonymousType(sourceType, out value);
return((NamedTypeSymbol)value.Type);
}
else if (sourceType.IsAnonymousType)
{
return(this.Visit(AnonymousTypeManager.TranslateAnonymousTypeSymbol(sourceType)));
}
else
{
return(FindMatchingNamespaceMember((NamespaceSymbol)otherContainer, sourceType, AreNamedTypesEqual));
}
case SymbolKind.NamedType:
return(FindMatchingNamedTypeMember((NamedTypeSymbol)otherContainer, sourceType, AreNamedTypesEqual));
default:
throw ExceptionUtilities.UnexpectedValue(otherContainer.Kind);
}
}
