private BoundExpression MakeIsOperator(
BoundIsOperator oldNode,
SyntaxNode 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(operandType is { } || rewrittenOperand.ConstantValue !.IsNull);
private BoundExpression MakeAsOperator(
BoundAsOperator oldNode,
SyntaxNode syntax,
BoundExpression rewrittenOperand,
BoundTypeExpression rewrittenTargetType,
Conversion conversion,
TypeSymbol rewrittenType)
{
// TODO: Handle dynamic operand type and target type
Debug.Assert(rewrittenTargetType.Type.Equals(rewrittenType));
// target type cannot be a non-nullable value type
Debug.Assert(!rewrittenType.IsValueType || rewrittenType.IsNullableType());
if (!_inExpressionLambda)
{
ConstantValue constantValue = Binder.GetAsOperatorConstantResult(rewrittenOperand.Type, rewrittenType, conversion.Kind, rewrittenOperand.ConstantValue);
if (constantValue != null)
{
Debug.Assert(constantValue.IsNull);
BoundExpression result = rewrittenType.IsNullableType() ? new BoundDefaultExpression(syntax, rewrittenType) : MakeLiteral(syntax, constantValue, rewrittenType);
if (rewrittenOperand.ConstantValue != null)
{
// No need to preserve any side-effects from the operand.
// We also can keep the "constant" notion of the result, which
// enables some optimizations down the road.
return(result);
}
return(new BoundSequence(
syntax: syntax,
locals: ImmutableArray <LocalSymbol> .Empty,
sideEffects: ImmutableArray.Create <BoundExpression>(rewrittenOperand),
value: result,
type: rewrittenType));
}
if (conversion.IsImplicit)
{
// Operand with bound implicit conversion to target type.
// We don't need a runtime check, generate a conversion for the operand instead.
return(MakeConversionNode(syntax, rewrittenOperand, conversion, rewrittenType, @checked: false));
}
}
return(oldNode.Update(rewrittenOperand, rewrittenTargetType, conversion, rewrittenType));
}
private BoundExpression MakeIsOperator(
BoundIsOperator oldNode,
SyntaxNode 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
return(MakeNullCheck(syntax, rewrittenOperand, BinaryOperatorKind.NotEqual));
}
}
return(oldNode.Update(rewrittenOperand, rewrittenTargetType, conversion, rewrittenType));
}
private BoundExpression MakeAsOperator(
BoundAsOperator oldNode,
CSharpSyntaxNode syntax,
BoundExpression rewrittenOperand,
BoundTypeExpression rewrittenTargetType,
Conversion conversion,
TypeSymbol rewrittenType)
{
// TODO: Handle dynamic operand type and target type
Debug.Assert(rewrittenTargetType.Type.Equals(rewrittenType));
// target type cannot be a non-nullable value type
Debug.Assert(!rewrittenType.IsValueType || rewrittenType.IsNullableType());
if (!_inExpressionLambda)
{
ConstantValue constantValue = Binder.GetAsOperatorConstantResult(rewrittenOperand.Type, rewrittenType, conversion.Kind, rewrittenOperand.ConstantValue);
if (constantValue != null)
{
Debug.Assert(constantValue.IsNull);
BoundExpression result = rewrittenType.IsNullableType() ? new BoundDefaultOperator(syntax, rewrittenType) : MakeLiteral(syntax, constantValue, rewrittenType);
if (rewrittenOperand.ConstantValue != null)
{
// No need to preserve any side-effects from the operand.
// We also can keep the "constant" notion of the result, which
// enables some optimizations down the road.
return result;
}
return new BoundSequence(
syntax: syntax,
locals: ImmutableArray<LocalSymbol>.Empty,
sideEffects: ImmutableArray.Create<BoundExpression>(rewrittenOperand),
value: result,
type: rewrittenType);
}
if (conversion.IsImplicit)
{
// Operand with bound implicit conversion to target type.
// We don't need a runtime check, generate a conversion for the operand instead.
return MakeConversionNode(syntax, rewrittenOperand, conversion, rewrittenType, @checked: false);
}
}
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));
}
private void XsInsertMissingOptionalArguments(SyntaxNode syntax,
ImmutableArray <ParameterSymbol> parameters,
BoundExpression[] arguments,
ArrayBuilder <RefKind> refKinds,
ArrayBuilder <LocalSymbol> temps,
ThreeState enableCallerInfo = ThreeState.Unknown
)
{
Debug.Assert(refKinds.Count == arguments.Length);
for (int p = 0; p < arguments.Length; ++p)
{
if (arguments[p] == null || arguments[p].Syntax.XIsMissingArgument)
{
ParameterSymbol parameter = parameters[p];
BoundExpression expr = GetDefaultParameterValue(syntax, parameter, enableCallerInfo);
if (expr is BoundDefaultExpression && parameter.Type == _compilation.UsualType())
{
var flds = _compilation.UsualType().GetMembers("_NIL");
var type = new BoundTypeExpression(syntax, null, _compilation.UsualType());
expr = _factory.Field(type, (FieldSymbol)flds[0]);
}
BoundAssignmentOperator boundAssignmentToTemp;
BoundLocal boundTemp = _factory.StoreToTemp(expr, out boundAssignmentToTemp);
expr = new BoundSequence(
syntax,
locals: ImmutableArray <LocalSymbol> .Empty,
sideEffects: ImmutableArray.Create <BoundExpression>(boundAssignmentToTemp),
value: boundTemp,
type: boundTemp.Type);
refKinds[p] = parameters[p].RefKind;
temps.Add(boundTemp.LocalSymbol);
arguments[p] = expr;
Debug.Assert(arguments[p].Type == parameter.Type);
if (parameters[p].RefKind == RefKind.In)
{
Debug.Assert(refKinds[p] == RefKind.None);
refKinds[p] = RefKind.In;
}
}
}
}
private BoundExpression MakeAsOperator(
BoundAsOperator oldNode,
CSharpSyntaxNode syntax,
BoundExpression rewrittenOperand,
BoundTypeExpression rewrittenTargetType,
Conversion conversion,
TypeSymbol rewrittenType)
{
// TODO: Handle dynamic operand type and target type
Debug.Assert(rewrittenTargetType.Type.Equals(rewrittenType));
// target type cannot be a non-nullable value type
Debug.Assert(!rewrittenType.IsValueType || rewrittenType.IsNullableType());
if (!inExpressionLambda)
{
ConstantValue constantValue = Binder.GetAsOperatorConstantResult(rewrittenOperand.Type, rewrittenType, conversion.Kind, rewrittenOperand.ConstantValue);
Debug.Assert(constantValue == null || constantValue.IsNull);
if (conversion.IsImplicit)
{
// Operand with bound implicit conversion to target type.
// We don't need a runtime check, generate a conversion for the operand instead.
return MakeConversion(syntax, rewrittenOperand, conversion, rewrittenType, @checked: false, constantValueOpt: constantValue);
}
else if (constantValue != null)
{
return new BoundSequence(
syntax: syntax,
locals: ImmutableArray<LocalSymbol>.Empty,
sideEffects: ImmutableArray.Create<BoundExpression>(rewrittenOperand),
value: MakeLiteral(syntax, constantValue, rewrittenType),
type: rewrittenType);
}
}
return oldNode.Update(rewrittenOperand, rewrittenTargetType, conversion, rewrittenType);
}
private BoundExpression MakeAsOperator(
BoundAsOperator oldNode,
CSharpSyntaxNode syntax,
BoundExpression rewrittenOperand,
BoundTypeExpression rewrittenTargetType,
Conversion conversion,
TypeSymbol rewrittenType)
{
// TODO: Handle dynamic operand type and target type
Debug.Assert(rewrittenTargetType.Type.Equals(rewrittenType));
// target type cannot be a non-nullable value type
Debug.Assert(!rewrittenType.IsValueType || rewrittenType.IsNullableType());
if (!inExpressionLambda)
{
ConstantValue constantValue = Binder.GetAsOperatorConstantResult(rewrittenOperand.Type, rewrittenType, conversion.Kind, rewrittenOperand.ConstantValue);
Debug.Assert(constantValue == null || constantValue.IsNull);
if (conversion.IsImplicit)
{
// Operand with bound implicit conversion to target type.
// We don't need a runtime check, generate a conversion for the operand instead.
return(MakeConversion(syntax, rewrittenOperand, conversion, rewrittenType, @checked: false, constantValueOpt: constantValue));
}
else if (constantValue != null)
{
return(new BoundSequence(
syntax: syntax,
locals: ImmutableArray <LocalSymbol> .Empty,
sideEffects: ImmutableArray.Create <BoundExpression>(rewrittenOperand),
value: MakeLiteral(syntax, constantValue, rewrittenType),
type: rewrittenType));
}
}
return(oldNode.Update(rewrittenOperand, rewrittenTargetType, conversion, rewrittenType));
}
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);
}
private BoundPattern BindDeclarationPattern(
DeclarationPatternSyntax node,
BoundExpression operand,
TypeSymbol operandType,
bool hasErrors,
DiagnosticBag diagnostics)
{
Debug.Assert(operand != null && operandType != (object)null);
var typeSyntax = node.Type;
bool isVar;
AliasSymbol aliasOpt;
TypeSymbol declType = BindType(typeSyntax, diagnostics, out isVar, out aliasOpt);
if (isVar)
{
declType = operandType;
}
if (declType == (object)null)
{
Debug.Assert(hasErrors);
declType = this.CreateErrorType("var");
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declType);
if (IsOperatorErrors(node, operandType, boundDeclType, diagnostics))
{
hasErrors = true;
}
else
{
hasErrors |= CheckValidPatternType(typeSyntax, operand, operandType, declType,
isVar: isVar, patternTypeWasInSource: true, diagnostics: diagnostics);
}
switch (node.Designation.Kind())
{
case SyntaxKind.SingleVariableDesignation:
break;
case SyntaxKind.DiscardedDesignation:
return new BoundDeclarationPattern(node, null, boundDeclType, isVar, hasErrors);
default:
throw ExceptionUtilities.UnexpectedValue(node.Designation.Kind());
}
var designation = (SingleVariableDesignationSyntax)node.Designation;
var identifier = designation.Identifier;
SourceLocalSymbol localSymbol = this.LookupLocal(identifier);
if (localSymbol != (object)null)
{
if (InConstructorInitializer || InFieldInitializer)
{
Error(diagnostics, ErrorCode.ERR_ExpressionVariableInConstructorOrFieldInitializer, node);
}
localSymbol.SetType(declType);
// Check for variable declaration errors.
hasErrors |= localSymbol.ScopeBinder.ValidateDeclarationNameConflictsInScope(localSymbol, diagnostics);
if (!hasErrors)
{
hasErrors = CheckRestrictedTypeInAsync(this.ContainingMemberOrLambda, declType, diagnostics, typeSyntax);
}
return new BoundDeclarationPattern(node, localSymbol, boundDeclType, isVar, hasErrors);
}
else
{
// We should have the right binder in the chain for a script or interactive, so we use the field for the pattern.
Debug.Assert(node.SyntaxTree.Options.Kind != SourceCodeKind.Regular);
GlobalExpressionVariable expressionVariableField = LookupDeclaredField(designation);
DiagnosticBag tempDiagnostics = DiagnosticBag.GetInstance();
expressionVariableField.SetType(declType, tempDiagnostics);
tempDiagnostics.Free();
BoundExpression receiver = SynthesizeReceiver(node, expressionVariableField, diagnostics);
var variableAccess = new BoundFieldAccess(node, receiver, expressionVariableField, null, hasErrors);
return new BoundDeclarationPattern(node, expressionVariableField, variableAccess, boundDeclType, isVar, hasErrors);
}
}
/// <summary>
/// Lower a foreach loop that will enumerate a collection using an enumerator.
///
/// E e = ((C)(x)).GetEnumerator()
/// try {
/// while (e.MoveNext()) {
/// V v = (V)(T)e.Current;
/// // body
/// }
/// }
/// finally {
/// // clean up e
/// }
/// </summary>
private BoundStatement RewriteEnumeratorForEachStatement(BoundForEachStatement node)
{
ForEachStatementSyntax forEachSyntax = (ForEachStatementSyntax)node.Syntax;
ForEachEnumeratorInfo enumeratorInfo = node.EnumeratorInfoOpt;
Debug.Assert(enumeratorInfo != null);
BoundExpression collectionExpression = GetUnconvertedCollectionExpression(node);
BoundExpression rewrittenExpression = (BoundExpression)Visit(collectionExpression);
BoundStatement rewrittenBody = (BoundStatement)Visit(node.Body);
TypeSymbol enumeratorType = enumeratorInfo.GetEnumeratorMethod.ReturnType;
TypeSymbol elementType = enumeratorInfo.ElementType;
// E e
LocalSymbol enumeratorVar = _factory.SynthesizedLocal(enumeratorType, syntax: forEachSyntax, kind: SynthesizedLocalKind.ForEachEnumerator);
// Reference to e.
BoundLocal boundEnumeratorVar = MakeBoundLocal(forEachSyntax, enumeratorVar, enumeratorType);
// ((C)(x)).GetEnumerator() or (x).GetEnumerator();
BoundExpression enumeratorVarInitValue = SynthesizeCall(forEachSyntax, rewrittenExpression, enumeratorInfo.GetEnumeratorMethod, enumeratorInfo.CollectionConversion, enumeratorInfo.CollectionType);
// E e = ((C)(x)).GetEnumerator();
BoundStatement enumeratorVarDecl = MakeLocalDeclaration(forEachSyntax, enumeratorVar, enumeratorVarInitValue);
AddForEachExpressionSequencePoint(forEachSyntax, ref enumeratorVarDecl);
// V v
LocalSymbol iterationVar = node.IterationVariable;
//(V)(T)e.Current
BoundExpression iterationVarAssignValue = MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.CurrentPropertyGetter),
conversion: enumeratorInfo.CurrentConversion,
rewrittenType: elementType,
@checked: node.Checked),
conversion: node.ElementConversion,
rewrittenType: iterationVar.Type,
@checked: node.Checked);
// V v = (V)(T)e.Current;
BoundStatement iterationVarDecl = MakeLocalDeclaration(forEachSyntax, iterationVar, iterationVarAssignValue);
AddForEachIterationVariableSequencePoint(forEachSyntax, ref iterationVarDecl);
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* node.Body */
// }
var rewrittenBodyBlock = CreateBlockDeclaringIterationVariable(iterationVar, iterationVarDecl, rewrittenBody, forEachSyntax);
BoundStatement whileLoop = RewriteWhileStatement(
syntax: forEachSyntax,
rewrittenCondition: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.MoveNextMethod),
conditionSequencePointSpan: forEachSyntax.InKeyword.Span,
rewrittenBody: rewrittenBodyBlock,
breakLabel: node.BreakLabel,
continueLabel: node.ContinueLabel,
hasErrors: false);
BoundStatement result;
MethodSymbol disposeMethod;
if (enumeratorInfo.NeedsDisposeMethod && Binder.TryGetSpecialTypeMember(_compilation, SpecialMember.System_IDisposable__Dispose, forEachSyntax, _diagnostics, out disposeMethod))
{
Binder.ReportDiagnosticsIfObsolete(_diagnostics, disposeMethod, forEachSyntax,
hasBaseReceiver: false,
containingMember: _factory.CurrentMethod,
containingType: _factory.CurrentType,
location: enumeratorInfo.Location);
BoundBlock finallyBlockOpt;
var idisposableTypeSymbol = disposeMethod.ContainingType;
var conversions = new TypeConversions(_factory.CurrentMethod.ContainingAssembly.CorLibrary);
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
var isImplicit = conversions.ClassifyImplicitConversion(enumeratorType, idisposableTypeSymbol, ref useSiteDiagnostics).IsImplicit;
_diagnostics.Add(forEachSyntax, useSiteDiagnostics);
if (isImplicit)
{
Debug.Assert(enumeratorInfo.NeedsDisposeMethod);
Conversion receiverConversion = enumeratorType.IsStructType() ?
Conversion.Boxing :
Conversion.ImplicitReference;
// ((IDisposable)e).Dispose(); or e.Dispose();
BoundStatement disposeCall = new BoundExpressionStatement(forEachSyntax,
expression: SynthesizeCall(forEachSyntax, boundEnumeratorVar, disposeMethod, receiverConversion, idisposableTypeSymbol));
BoundStatement disposeStmt;
if (enumeratorType.IsValueType)
{
// No way for the struct to be nullable and disposable.
Debug.Assert(((TypeSymbol)enumeratorType.OriginalDefinition).SpecialType != SpecialType.System_Nullable_T);
// For non-nullable structs, no null check is required.
disposeStmt = disposeCall;
}
else
{
// NB: cast to object missing from spec. Needed to ignore user-defined operators and box type parameters.
// if ((object)e != null) ((IDisposable)e).Dispose();
disposeStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual,
left: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: boundEnumeratorVar,
conversion: enumeratorInfo.EnumeratorConversion,
rewrittenType: _compilation.GetSpecialType(SpecialType.System_Object),
@checked: false),
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: disposeCall,
rewrittenAlternativeOpt: null,
hasErrors: false);
}
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray <LocalSymbol> .Empty,
localFunctions: ImmutableArray <LocalFunctionSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(disposeStmt));
}
else
{
Debug.Assert(!enumeratorType.IsSealed);
// IDisposable d
LocalSymbol disposableVar = _factory.SynthesizedLocal(idisposableTypeSymbol);
// Reference to d.
BoundLocal boundDisposableVar = MakeBoundLocal(forEachSyntax, disposableVar, idisposableTypeSymbol);
BoundTypeExpression boundIDisposableTypeExpr = new BoundTypeExpression(forEachSyntax,
aliasOpt: null,
type: idisposableTypeSymbol);
// e as IDisposable
BoundExpression disposableVarInitValue = new BoundAsOperator(forEachSyntax,
operand: boundEnumeratorVar,
targetType: boundIDisposableTypeExpr,
conversion: Conversion.ExplicitReference, // Explicit so the emitter won't optimize it away.
type: idisposableTypeSymbol);
// IDisposable d = e as IDisposable;
BoundStatement disposableVarDecl = MakeLocalDeclaration(forEachSyntax, disposableVar, disposableVarInitValue);
// if (d != null) d.Dispose();
BoundStatement ifStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual, // reference equality
left: boundDisposableVar,
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: new BoundExpressionStatement(forEachSyntax,
expression: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundDisposableVar,
method: disposeMethod)),
rewrittenAlternativeOpt: null,
hasErrors: false);
// IDisposable d = e as IDisposable;
// if (d != null) d.Dispose();
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray.Create <LocalSymbol>(disposableVar),
localFunctions: ImmutableArray <LocalFunctionSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(disposableVarDecl, ifStmt));
}
// try {
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
// }
// finally {
// /* dispose of e */
// }
BoundStatement tryFinally = new BoundTryStatement(forEachSyntax,
tryBlock: new BoundBlock(forEachSyntax,
locals: ImmutableArray <LocalSymbol> .Empty,
localFunctions: ImmutableArray <LocalFunctionSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(whileLoop)),
catchBlocks: ImmutableArray <BoundCatchBlock> .Empty,
finallyBlockOpt: finallyBlockOpt);
// E e = ((C)(x)).GetEnumerator();
// try {
// /* as above */
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
localFunctions: ImmutableArray <LocalFunctionSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(enumeratorVarDecl, tryFinally));
}
else
{
// E e = ((C)(x)).GetEnumerator();
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
localFunctions: ImmutableArray <LocalFunctionSymbol> .Empty,
statements: ImmutableArray.Create <BoundStatement>(enumeratorVarDecl, whileLoop));
}
AddForEachKeywordSequencePoint(forEachSyntax, ref result);
return(result);
}
public BoundExpression VisitDynamicInvocation(BoundDynamicInvocation node, bool resultDiscarded)
{
var loweredArguments = VisitList(node.Arguments);
bool hasImplicitReceiver;
BoundExpression loweredReceiver;
ImmutableArray<TypeSymbol> typeArguments;
string name;
switch (node.Expression.Kind)
{
case BoundKind.MethodGroup:
// method invocation
BoundMethodGroup methodGroup = (BoundMethodGroup)node.Expression;
typeArguments = methodGroup.TypeArgumentsOpt;
name = methodGroup.Name;
hasImplicitReceiver = (methodGroup.Flags & BoundMethodGroupFlags.HasImplicitReceiver) != 0;
// Should have been eliminated during binding of dynamic invocation:
Debug.Assert(methodGroup.ReceiverOpt == null || methodGroup.ReceiverOpt.Kind != BoundKind.TypeOrValueExpression);
if (methodGroup.ReceiverOpt == null)
{
// Calling a static method defined on an outer class via its simple name.
NamedTypeSymbol firstContainer = node.ApplicableMethods.First().ContainingType;
Debug.Assert(node.ApplicableMethods.All(m => m.IsStatic && m.ContainingType == firstContainer));
loweredReceiver = new BoundTypeExpression(node.Syntax, null, firstContainer);
}
else if (hasImplicitReceiver && _factory.TopLevelMethod.IsStatic)
{
// Calling a static method defined on the current class via its simple name.
loweredReceiver = new BoundTypeExpression(node.Syntax, null, _factory.CurrentType);
}
else
{
loweredReceiver = VisitExpression(methodGroup.ReceiverOpt);
}
// If we are calling a method on a NoPIA type, we need to embed all methods/properties
// with the matching name of this dynamic invocation.
EmbedIfNeedTo(loweredReceiver, methodGroup.Methods, node.Syntax);
break;
case BoundKind.DynamicMemberAccess:
// method invocation
var memberAccess = (BoundDynamicMemberAccess)node.Expression;
name = memberAccess.Name;
typeArguments = memberAccess.TypeArgumentsOpt;
loweredReceiver = VisitExpression(memberAccess.Receiver);
hasImplicitReceiver = false;
break;
default:
// delegate invocation
var loweredExpression = VisitExpression(node.Expression);
return _dynamicFactory.MakeDynamicInvocation(loweredExpression, loweredArguments, node.ArgumentNamesOpt, node.ArgumentRefKindsOpt, resultDiscarded).ToExpression();
}
Debug.Assert(loweredReceiver != null);
return _dynamicFactory.MakeDynamicMemberInvocation(
name,
loweredReceiver,
typeArguments,
loweredArguments,
node.ArgumentNamesOpt,
node.ArgumentRefKindsOpt,
hasImplicitReceiver,
resultDiscarded).ToExpression();
}
private BoundPattern BindDeclarationPattern(
DeclarationPatternSyntax node,
TypeSymbol operandType,
bool hasErrors,
DiagnosticBag diagnostics)
{
Debug.Assert(operandType != (object)null);
var typeSyntax = node.Type;
bool isVar;
AliasSymbol aliasOpt;
TypeSymbol declType = BindTypeOrVarKeyword(typeSyntax, diagnostics, out isVar, out aliasOpt);
if (isVar)
{
declType = operandType;
}
if (declType == (object)null)
{
Debug.Assert(hasErrors);
declType = this.CreateErrorType("var");
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declType);
if (IsOperatorErrors(node, operandType, boundDeclType, diagnostics))
{
hasErrors = true;
}
else
{
hasErrors |= CheckValidPatternType(typeSyntax, operandType, declType,
isVar: isVar, patternTypeWasInSource: true, diagnostics: diagnostics);
}
switch (node.Designation.Kind())
{
case SyntaxKind.SingleVariableDesignation:
break;
case SyntaxKind.DiscardDesignation:
return(new BoundDeclarationPattern(node, null, boundDeclType, isVar, hasErrors));
default:
throw ExceptionUtilities.UnexpectedValue(node.Designation.Kind());
}
var designation = (SingleVariableDesignationSyntax)node.Designation;
var identifier = designation.Identifier;
SourceLocalSymbol localSymbol = this.LookupLocal(identifier);
if (localSymbol != (object)null)
{
if ((InConstructorInitializer || InFieldInitializer) && ContainingMemberOrLambda.ContainingSymbol.Kind == SymbolKind.NamedType)
{
CheckFeatureAvailability(node, MessageID.IDS_FeatureExpressionVariablesInQueriesAndInitializers, diagnostics);
}
localSymbol.SetType(declType);
// Check for variable declaration errors.
hasErrors |= localSymbol.ScopeBinder.ValidateDeclarationNameConflictsInScope(localSymbol, diagnostics);
if (!hasErrors)
{
hasErrors = CheckRestrictedTypeInAsync(this.ContainingMemberOrLambda, declType, diagnostics, typeSyntax);
}
return(new BoundDeclarationPattern(node, localSymbol, boundDeclType, isVar, hasErrors));
}
else
{
// We should have the right binder in the chain for a script or interactive, so we use the field for the pattern.
Debug.Assert(node.SyntaxTree.Options.Kind != SourceCodeKind.Regular);
GlobalExpressionVariable expressionVariableField = LookupDeclaredField(designation);
DiagnosticBag tempDiagnostics = DiagnosticBag.GetInstance();
expressionVariableField.SetType(declType, tempDiagnostics);
tempDiagnostics.Free();
BoundExpression receiver = SynthesizeReceiver(node, expressionVariableField, diagnostics);
var variableAccess = new BoundFieldAccess(node, receiver, expressionVariableField, null, hasErrors);
return(new BoundDeclarationPattern(node, expressionVariableField, variableAccess, boundDeclType, isVar, hasErrors));
}
}
public override BoundNode VisitTypeExpression(BoundTypeExpression node)
{
var result = base.VisitTypeExpression(node);
Debug.Assert(result is { });
/// <summary>
/// Lower a foreach loop that will enumerate a collection using an enumerator.
///
/// E e = ((C)(x)).GetEnumerator()
/// try {
/// while (e.MoveNext()) {
/// V v = (V)(T)e.Current;
/// // body
/// }
/// }
/// finally {
/// // clean up e
/// }
/// </summary>
private BoundStatement RewriteEnumeratorForEachStatement(BoundForEachStatement node)
{
ForEachStatementSyntax forEachSyntax = (ForEachStatementSyntax)node.Syntax;
ForEachEnumeratorInfo enumeratorInfo = node.EnumeratorInfoOpt;
Debug.Assert(enumeratorInfo != null);
BoundExpression collectionExpression = GetUnconvertedCollectionExpression(node);
BoundExpression rewrittenExpression = (BoundExpression)Visit(collectionExpression);
BoundStatement rewrittenBody = (BoundStatement)Visit(node.Body);
TypeSymbol enumeratorType = enumeratorInfo.GetEnumeratorMethod.ReturnType;
TypeSymbol elementType = enumeratorInfo.ElementType;
// E e
LocalSymbol enumeratorVar = _factory.SynthesizedLocal(enumeratorType, syntax: forEachSyntax, kind: SynthesizedLocalKind.ForEachEnumerator);
// Reference to e.
BoundLocal boundEnumeratorVar = MakeBoundLocal(forEachSyntax, enumeratorVar, enumeratorType);
// ((C)(x)).GetEnumerator() or (x).GetEnumerator();
BoundExpression enumeratorVarInitValue = SynthesizeCall(forEachSyntax, rewrittenExpression, enumeratorInfo.GetEnumeratorMethod, enumeratorInfo.CollectionConversion, enumeratorInfo.CollectionType);
// E e = ((C)(x)).GetEnumerator();
BoundStatement enumeratorVarDecl = MakeLocalDeclaration(forEachSyntax, enumeratorVar, enumeratorVarInitValue);
AddForEachExpressionSequencePoint(forEachSyntax, ref enumeratorVarDecl);
// V v
LocalSymbol iterationVar = node.IterationVariable;
//(V)(T)e.Current
BoundExpression iterationVarAssignValue = MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.CurrentPropertyGetter),
conversion: enumeratorInfo.CurrentConversion,
rewrittenType: elementType,
@checked: node.Checked),
conversion: node.ElementConversion,
rewrittenType: iterationVar.Type,
@checked: node.Checked);
// V v = (V)(T)e.Current;
BoundStatement iterationVarDecl = MakeLocalDeclaration(forEachSyntax, iterationVar, iterationVarAssignValue);
AddForEachIterationVariableSequencePoint(forEachSyntax, ref iterationVarDecl);
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* node.Body */
// }
var rewrittenBodyBlock = CreateBlockDeclaringIterationVariable(iterationVar, iterationVarDecl, rewrittenBody, forEachSyntax);
BoundStatement whileLoop = RewriteWhileStatement(
syntax: forEachSyntax,
rewrittenCondition: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundEnumeratorVar,
method: enumeratorInfo.MoveNextMethod),
conditionSequencePointSpan: forEachSyntax.InKeyword.Span,
rewrittenBody: rewrittenBodyBlock,
breakLabel: node.BreakLabel,
continueLabel: node.ContinueLabel,
hasErrors: false);
BoundStatement result;
MethodSymbol disposeMethod;
if (enumeratorInfo.NeedsDisposeMethod && Binder.TryGetSpecialTypeMember(_compilation, SpecialMember.System_IDisposable__Dispose, forEachSyntax, _diagnostics, out disposeMethod))
{
Binder.ReportDiagnosticsIfObsolete(_diagnostics, disposeMethod, forEachSyntax,
hasBaseReceiver: false,
containingMember: _factory.CurrentMethod,
containingType: _factory.CurrentType,
location: enumeratorInfo.Location);
BoundBlock finallyBlockOpt;
var idisposableTypeSymbol = disposeMethod.ContainingType;
var conversions = new TypeConversions(_factory.CurrentMethod.ContainingAssembly.CorLibrary);
HashSet<DiagnosticInfo> useSiteDiagnostics = null;
var isImplicit = conversions.ClassifyImplicitConversion(enumeratorType, idisposableTypeSymbol, ref useSiteDiagnostics).IsImplicit;
_diagnostics.Add(forEachSyntax, useSiteDiagnostics);
if (isImplicit)
{
Debug.Assert(enumeratorInfo.NeedsDisposeMethod);
Conversion receiverConversion = enumeratorType.IsStructType() ?
Conversion.Boxing :
Conversion.ImplicitReference;
// ((IDisposable)e).Dispose(); or e.Dispose();
BoundStatement disposeCall = new BoundExpressionStatement(forEachSyntax,
expression: SynthesizeCall(forEachSyntax, boundEnumeratorVar, disposeMethod, receiverConversion, idisposableTypeSymbol));
BoundStatement disposeStmt;
if (enumeratorType.IsValueType)
{
// No way for the struct to be nullable and disposable.
Debug.Assert(((TypeSymbol)enumeratorType.OriginalDefinition).SpecialType != SpecialType.System_Nullable_T);
// For non-nullable structs, no null check is required.
disposeStmt = disposeCall;
}
else
{
// NB: cast to object missing from spec. Needed to ignore user-defined operators and box type parameters.
// if ((object)e != null) ((IDisposable)e).Dispose();
disposeStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual,
left: MakeConversion(
syntax: forEachSyntax,
rewrittenOperand: boundEnumeratorVar,
conversion: enumeratorInfo.EnumeratorConversion,
rewrittenType: _compilation.GetSpecialType(SpecialType.System_Object),
@checked: false),
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: disposeCall,
rewrittenAlternativeOpt: null,
hasErrors: false);
}
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray<LocalSymbol>.Empty,
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(disposeStmt));
}
else
{
Debug.Assert(!enumeratorType.IsSealed);
// IDisposable d
LocalSymbol disposableVar = _factory.SynthesizedLocal(idisposableTypeSymbol);
// Reference to d.
BoundLocal boundDisposableVar = MakeBoundLocal(forEachSyntax, disposableVar, idisposableTypeSymbol);
BoundTypeExpression boundIDisposableTypeExpr = new BoundTypeExpression(forEachSyntax,
aliasOpt: null,
type: idisposableTypeSymbol);
// e as IDisposable
BoundExpression disposableVarInitValue = new BoundAsOperator(forEachSyntax,
operand: boundEnumeratorVar,
targetType: boundIDisposableTypeExpr,
conversion: Conversion.ExplicitReference, // Explicit so the emitter won't optimize it away.
type: idisposableTypeSymbol);
// IDisposable d = e as IDisposable;
BoundStatement disposableVarDecl = MakeLocalDeclaration(forEachSyntax, disposableVar, disposableVarInitValue);
// if (d != null) d.Dispose();
BoundStatement ifStmt = RewriteIfStatement(
syntax: forEachSyntax,
rewrittenCondition: new BoundBinaryOperator(forEachSyntax,
operatorKind: BinaryOperatorKind.NotEqual, // reference equality
left: boundDisposableVar,
right: MakeLiteral(forEachSyntax,
constantValue: ConstantValue.Null,
type: null),
constantValueOpt: null,
methodOpt: null,
resultKind: LookupResultKind.Viable,
type: _compilation.GetSpecialType(SpecialType.System_Boolean)),
rewrittenConsequence: new BoundExpressionStatement(forEachSyntax,
expression: BoundCall.Synthesized(
syntax: forEachSyntax,
receiverOpt: boundDisposableVar,
method: disposeMethod)),
rewrittenAlternativeOpt: null,
hasErrors: false);
// IDisposable d = e as IDisposable;
// if (d != null) d.Dispose();
finallyBlockOpt = new BoundBlock(forEachSyntax,
locals: ImmutableArray.Create<LocalSymbol>(disposableVar),
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(disposableVarDecl, ifStmt));
}
// try {
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
// }
// finally {
// /* dispose of e */
// }
BoundStatement tryFinally = new BoundTryStatement(forEachSyntax,
tryBlock: new BoundBlock(forEachSyntax,
locals: ImmutableArray<LocalSymbol>.Empty,
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(whileLoop)),
catchBlocks: ImmutableArray<BoundCatchBlock>.Empty,
finallyBlockOpt: finallyBlockOpt);
// E e = ((C)(x)).GetEnumerator();
// try {
// /* as above */
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(enumeratorVarDecl, tryFinally));
}
else
{
// E e = ((C)(x)).GetEnumerator();
// while (e.MoveNext()) {
// V v = (V)(T)e.Current;
// /* loop body */
// }
result = new BoundBlock(
syntax: forEachSyntax,
locals: ImmutableArray.Create(enumeratorVar),
localFunctions: ImmutableArray<LocalFunctionSymbol>.Empty,
statements: ImmutableArray.Create<BoundStatement>(enumeratorVarDecl, whileLoop));
}
AddForEachKeywordSequencePoint(forEachSyntax, ref result);
return result;
}
public BoundDeclarationPattern(SyntaxNode syntax, LocalSymbol localSymbol, BoundTypeExpression declaredType, bool isVar, bool hasErrors = false)
: this(syntax, localSymbol, localSymbol == null ? new BoundDiscardExpression(syntax, declaredType.Type) : (BoundExpression) new BoundLocal(syntax, localSymbol, null, declaredType.Type), declaredType, isVar, hasErrors)
{
}
public BoundTypeExpression(SyntaxNode syntax, AliasSymbol aliasOpt, BoundTypeExpression boundContainingTypeOpt, ImmutableArray <BoundExpression> boundDimensionsOpt, TypeWithAnnotations typeWithAnnotations, bool hasErrors = false)
: this(syntax, aliasOpt, boundContainingTypeOpt, boundDimensionsOpt, typeWithAnnotations, typeWithAnnotations.Type, hasErrors)
{
Debug.Assert((object)typeWithAnnotations.Type != null, "Field 'type' cannot be null");
}
private BoundForEachStatement BindForEachPartsWorker(DiagnosticBag diagnostics)
{
BoundExpression collectionExpr = this.Next.BindValue(syntax.Expression, diagnostics, BindValueKind.RValue); //bind with next to avoid seeing iteration variable
ForEachEnumeratorInfo.Builder builder = new ForEachEnumeratorInfo.Builder();
TypeSymbol inferredType;
bool hasErrors = !GetEnumeratorInfoAndInferCollectionElementType(ref builder, ref collectionExpr, diagnostics, out inferredType);
// These should only occur when special types are missing or malformed.
hasErrors = hasErrors ||
(object)builder.GetEnumeratorMethod == null ||
(object)builder.MoveNextMethod == null ||
(object)builder.CurrentPropertyGetter == null;
// Check for local variable conflicts in the *enclosing* binder; obviously the *current*
// binder has a local that matches!
hasErrors |= this.ValidateDeclarationNameConflictsInScope(IterationVariable, diagnostics);
// If the type in syntax is "var", then the type should be set explicitly so that the
// Type property doesn't fail.
TypeSyntax typeSyntax = this.syntax.Type;
bool isVar;
AliasSymbol alias;
TypeSymbol declType = BindType(typeSyntax, diagnostics, out isVar, out alias);
TypeSymbol iterationVariableType;
if (isVar)
{
iterationVariableType = inferredType ?? CreateErrorType("var");
}
else
{
Debug.Assert((object)declType != null);
iterationVariableType = declType;
}
BoundTypeExpression boundIterationVariableType = new BoundTypeExpression(typeSyntax, alias, iterationVariableType);
this.IterationVariable.SetTypeSymbol(iterationVariableType);
BoundStatement body = BindPossibleEmbeddedStatement(syntax.Statement, diagnostics);
hasErrors = hasErrors || iterationVariableType.IsErrorType();
// Skip the conversion checks and array/enumerator differentiation if we know we have an error.
if (hasErrors)
{
return(new BoundForEachStatement(
syntax,
ImmutableArray <LocalSymbol> .Empty,
null, // can't be sure that it's complete
default(Conversion),
boundIterationVariableType,
this.IterationVariable,
collectionExpr,
body,
CheckOverflowAtRuntime,
this.BreakLabel,
this.ContinueLabel,
hasErrors));
}
var foreachKeyword = syntax.ForEachKeyword;
ReportDiagnosticsIfObsolete(diagnostics, builder.GetEnumeratorMethod, foreachKeyword, hasBaseReceiver: false);
ReportDiagnosticsIfObsolete(diagnostics, builder.MoveNextMethod, foreachKeyword, hasBaseReceiver: false);
ReportDiagnosticsIfObsolete(diagnostics, builder.CurrentPropertyGetter, foreachKeyword, hasBaseReceiver: false);
ReportDiagnosticsIfObsolete(diagnostics, builder.CurrentPropertyGetter.AssociatedSymbol, foreachKeyword, hasBaseReceiver: false);
// We want to convert from inferredType in the array/string case and builder.ElementType in the enumerator case,
// but it turns out that these are equivalent (when both are available).
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
Conversion elementConversion = this.Conversions.ClassifyConversionForCast(inferredType, iterationVariableType, ref useSiteDiagnostics);
if (!elementConversion.IsValid)
{
ImmutableArray <MethodSymbol> originalUserDefinedConversions = elementConversion.OriginalUserDefinedConversions;
if (originalUserDefinedConversions.Length > 1)
{
diagnostics.Add(ErrorCode.ERR_AmbigUDConv, syntax.ForEachKeyword.GetLocation(), originalUserDefinedConversions[0], originalUserDefinedConversions[1], inferredType, iterationVariableType);
}
else
{
SymbolDistinguisher distinguisher = new SymbolDistinguisher(this.Compilation, inferredType, iterationVariableType);
diagnostics.Add(ErrorCode.ERR_NoExplicitConv, syntax.ForEachKeyword.GetLocation(), distinguisher.First, distinguisher.Second);
}
hasErrors = true;
}
else
{
ReportDiagnosticsIfObsolete(diagnostics, elementConversion, syntax.ForEachKeyword, hasBaseReceiver: false);
}
// Spec (§8.8.4):
// If the type X of expression is dynamic then there is an implicit conversion from >>expression<< (not the type of the expression)
// to the System.Collections.IEnumerable interface (§6.1.8).
builder.CollectionConversion = this.Conversions.ClassifyConversionFromExpression(collectionExpr, builder.CollectionType, ref useSiteDiagnostics);
builder.CurrentConversion = this.Conversions.ClassifyConversion(builder.CurrentPropertyGetter.ReturnType, builder.ElementType, ref useSiteDiagnostics);
builder.EnumeratorConversion = this.Conversions.ClassifyConversion(builder.GetEnumeratorMethod.ReturnType, GetSpecialType(SpecialType.System_Object, diagnostics, this.syntax), ref useSiteDiagnostics);
diagnostics.Add(syntax.ForEachKeyword.GetLocation(), useSiteDiagnostics);
// Due to the way we extracted the various types, these conversions should always be possible.
// CAVEAT: if we're iterating over an array of pointers, the current conversion will fail since we
// can't convert from object to a pointer type. Similarly, if we're iterating over an array of
// Nullable<Error>, the current conversion will fail because we don't know if an ErrorType is a
// value type. This doesn't matter in practice, since we won't actually use the enumerator pattern
// when we lower the loop.
Debug.Assert(builder.CollectionConversion.IsValid);
Debug.Assert(builder.CurrentConversion.IsValid ||
(builder.ElementType.IsPointerType() && collectionExpr.Type.IsArray()) ||
(builder.ElementType.IsNullableType() && builder.ElementType.GetMemberTypeArgumentsNoUseSiteDiagnostics().Single().IsErrorType() && collectionExpr.Type.IsArray()));
Debug.Assert(builder.EnumeratorConversion.IsValid ||
this.Compilation.GetSpecialType(SpecialType.System_Object).TypeKind == TypeKind.Error,
"Conversions to object succeed unless there's a problem with the object type");
// If user-defined conversions could occur here, we would need to check for ObsoleteAttribute.
Debug.Assert((object)builder.CollectionConversion.Method == null,
"Conversion from collection expression to collection type should not be user-defined");
Debug.Assert((object)builder.CurrentConversion.Method == null,
"Conversion from Current property type to element type should not be user-defined");
Debug.Assert((object)builder.EnumeratorConversion.Method == null,
"Conversion from GetEnumerator return type to System.Object should not be user-defined");
// We're wrapping the collection expression in a (non-synthesized) conversion so that its converted
// type (i.e. builder.CollectionType) will be available in the binding API.
BoundConversion convertedCollectionExpression = new BoundConversion(
collectionExpr.Syntax,
collectionExpr,
builder.CollectionConversion,
CheckOverflowAtRuntime,
false,
ConstantValue.NotAvailable,
builder.CollectionType);
return(new BoundForEachStatement(
syntax,
ImmutableArray <LocalSymbol> .Empty,
builder.Build(this.Flags),
elementConversion,
boundIterationVariableType,
this.IterationVariable,
convertedCollectionExpression,
body,
CheckOverflowAtRuntime,
this.BreakLabel,
this.ContinueLabel,
hasErrors));
}
private BoundExpression BindIsOperator(BinaryExpressionSyntax node, DiagnosticBag diagnostics)
{
var resultType = (TypeSymbol)GetSpecialType(SpecialType.System_Boolean, diagnostics, node);
var operand = BindValue(node.Left, diagnostics, BindValueKind.RValue);
AliasSymbol alias;
TypeSymbol targetType;
{
// try binding as a type, but back off to binding as an expression if that does not work.
var tempBag = DiagnosticBag.GetInstance();
targetType = BindType(node.Right, tempBag, out alias);
if (targetType?.IsErrorType() == true && tempBag.HasAnyResolvedErrors() &&
((CSharpParseOptions)node.SyntaxTree.Options).IsFeatureEnabled(MessageID.IDS_FeaturePatternMatching))
{
// it did not bind as a type; try binding as a constant expression pattern
bool wasExpression;
var tempBag2 = DiagnosticBag.GetInstance();
var boundConstantPattern = BindConstantPattern(
node, operand, operand.Type, node.Right, node.Right.HasErrors, tempBag2, out wasExpression, wasSwitchCase: false);
if (wasExpression)
{
tempBag.Free();
diagnostics.AddRangeAndFree(tempBag2);
return new BoundIsPatternExpression(node, operand, boundConstantPattern, resultType);
}
tempBag2.Free();
}
diagnostics.AddRangeAndFree(tempBag);
}
var typeExpression = new BoundTypeExpression(node.Right, alias, targetType);
var targetTypeKind = targetType.TypeKind;
if (IsOperandErrors(node, operand, diagnostics) || IsOperatorErrors(node, operand.Type, typeExpression, diagnostics))
{
return new BoundIsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
// Is and As operator should have null ConstantValue as they are not constant expressions.
// However we perform analysis of is/as expressions at bind time to detect if the expression
// will always evaluate to a constant to generate warnings (always true/false/null).
// We also need this analysis result during rewrite to optimize away redundant isinst instructions.
// We store the conversion from expression's operand type to target type to enable these
// optimizations during is/as operator rewrite.
HashSet<DiagnosticInfo> useSiteDiagnostics = null;
if (operand.ConstantValue == ConstantValue.Null ||
operand.Kind == BoundKind.MethodGroup ||
operand.Type.SpecialType == SpecialType.System_Void)
{
// warning for cases where the result is always false:
// (a) "null is TYPE" OR operand evaluates to null
// (b) operand is a MethodGroup
// (c) operand is of void type
// NOTE: Dev10 violates the SPEC for case (c) above and generates
// NOTE: an error ERR_NoExplicitBuiltinConv if the target type
// NOTE: is an open type. According to the specification, the result
// NOTE: is always false, but no compile time error occurs.
// NOTE: We follow the specification and generate WRN_IsAlwaysFalse
// NOTE: instead of an error.
// NOTE: See Test SyntaxBinderTests.TestIsOperatorWithTypeParameter
Error(diagnostics, ErrorCode.WRN_IsAlwaysFalse, node, targetType);
Conversion conv = Conversions.ClassifyConversionFromExpression(operand, targetType, ref useSiteDiagnostics);
diagnostics.Add(node, useSiteDiagnostics);
return new BoundIsOperator(node, operand, typeExpression, conv, resultType);
}
if (targetTypeKind == TypeKind.Dynamic)
{
// warning for dynamic target type
Error(diagnostics, ErrorCode.WRN_IsDynamicIsConfusing,
node, node.OperatorToken.Text, targetType.Name,
GetSpecialType(SpecialType.System_Object, diagnostics, node).Name // a pretty way of getting the string "Object"
);
}
var operandType = operand.Type;
Debug.Assert((object)operandType != null);
if (operandType.TypeKind == TypeKind.Dynamic)
{
// if operand has a dynamic type, we do the same thing as though it were an object
operandType = GetSpecialType(SpecialType.System_Object, diagnostics, node);
}
Conversion conversion = Conversions.ClassifyConversion(operandType, targetType, ref useSiteDiagnostics);
diagnostics.Add(node, useSiteDiagnostics);
ReportIsOperatorConstantWarnings(node, diagnostics, operandType, targetType, conversion.Kind, operand.ConstantValue);
return new BoundIsOperator(node, operand, typeExpression, conversion, resultType);
}
private BoundPattern BindDeclarationPattern(
DeclarationPatternSyntax node,
BoundExpression operand,
TypeSymbol operandType,
bool hasErrors,
DiagnosticBag diagnostics)
{
Debug.Assert(operand != null || operandType != (object)null);
var typeSyntax = node.Type;
var identifier = node.Identifier;
bool isVar;
AliasSymbol aliasOpt;
TypeSymbol declType = BindType(typeSyntax, diagnostics, out isVar, out aliasOpt);
if (isVar && operandType != (object)null)
{
declType = operandType;
}
if (declType == (object)null)
{
Debug.Assert(hasErrors);
declType = this.CreateErrorType();
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declType);
if (IsOperatorErrors(node, operandType, boundDeclType, diagnostics))
{
hasErrors = true;
}
else
{
hasErrors |= CheckValidPatternType(typeSyntax, operand, operandType, declType,
isVar: isVar, patternTypeWasInSource: true, diagnostics: diagnostics);
}
SourceLocalSymbol localSymbol = this.LookupLocal(identifier);
// In error scenarios with misplaced code, it is possible we can't bind the local declaration.
// This occurs through the semantic model. In that case concoct a plausible result.
if (localSymbol == (object)null)
{
localSymbol = SourceLocalSymbol.MakeLocal(
ContainingMemberOrLambda,
this,
RefKind.None,
typeSyntax,
identifier,
LocalDeclarationKind.PatternVariable);
}
if (isVar)
{
localSymbol.SetTypeSymbol(operandType);
}
// Check for variable declaration errors.
hasErrors |= this.ValidateDeclarationNameConflictsInScope(localSymbol, diagnostics);
if (this.ContainingMemberOrLambda.Kind == SymbolKind.Method
&& ((MethodSymbol)this.ContainingMemberOrLambda).IsAsync
&& declType.IsRestrictedType()
&& !hasErrors)
{
Error(diagnostics, ErrorCode.ERR_BadSpecialByRefLocal, typeSyntax, declType);
hasErrors = true;
}
DeclareLocalVariable(localSymbol, identifier, declType);
return new BoundDeclarationPattern(node, localSymbol, boundDeclType, isVar, hasErrors);
}
public BoundTypeExpression(SyntaxNode syntax, AliasSymbol aliasOpt, BoundTypeExpression boundContainingTypeOpt, TypeWithAnnotations typeWithAnnotations, bool hasErrors = false)
: this(syntax, aliasOpt, boundContainingTypeOpt, ImmutableArray <BoundExpression> .Empty, typeWithAnnotations, hasErrors)
{
}
protected BoundLocalDeclaration BindVariableDeclaration(
LocalDeclarationKind kind,
bool isVar,
VariableDeclaratorSyntax declarator,
TypeSyntax typeSyntax,
TypeSymbol declTypeOpt,
AliasSymbol aliasOpt,
DiagnosticBag diagnostics,
CSharpSyntaxNode associatedSyntaxNode = null)
{
Debug.Assert(declarator != null);
Debug.Assert((object)declTypeOpt != null || isVar);
Debug.Assert(typeSyntax != null);
// if we are not given desired syntax, we use declarator
associatedSyntaxNode = associatedSyntaxNode ?? declarator;
bool hasErrors = false;
BoundExpression initializerOpt;
SourceLocalSymbol localSymbol = this.LookupLocal(declarator.Identifier);
// In error scenarios with misplaced code, it is possible we can't bind the local declaration.
// This occurs through the semantic model. In that case concoct a plausible result.
if ((object)localSymbol == null)
{
localSymbol = SourceLocalSymbol.MakeLocal(
ContainingMemberOrLambda as MethodSymbol, this, typeSyntax,
declarator.Identifier, declarator.Initializer, LocalDeclarationKind.Variable);
}
// Check for variable declaration errors.
hasErrors |= this.EnsureDeclarationInvariantMeaningInScope(localSymbol, diagnostics);
EqualsValueClauseSyntax equalsValueClauseSyntax = declarator.Initializer;
if (isVar)
{
aliasOpt = null;
var binder = new ImplicitlyTypedLocalBinder(this, localSymbol);
initializerOpt = binder.BindInferredVariableInitializer(diagnostics, equalsValueClauseSyntax, declarator);
// If we got a good result then swap the inferred type for the "var"
if (initializerOpt != null && (object)initializerOpt.Type != null)
{
declTypeOpt = initializerOpt.Type;
if (declTypeOpt.SpecialType == SpecialType.System_Void)
{
Error(diagnostics, ErrorCode.ERR_ImplicitlyTypedVariableAssignedBadValue, declarator, declTypeOpt);
declTypeOpt = CreateErrorType("var");
hasErrors = true;
}
if (!declTypeOpt.IsErrorType())
{
if (declTypeOpt.IsStatic)
{
Error(diagnostics, ErrorCode.ERR_VarDeclIsStaticClass, typeSyntax, initializerOpt.Type);
hasErrors = true;
}
}
}
else
{
declTypeOpt = CreateErrorType("var");
hasErrors = true;
}
}
else
{
if (ReferenceEquals(equalsValueClauseSyntax, null))
{
initializerOpt = null;
}
else
{
// Basically inlined BindVariableInitializer, but with conversion optional.
initializerOpt = BindPossibleArrayInitializer(equalsValueClauseSyntax.Value, declTypeOpt, diagnostics);
if (kind != LocalDeclarationKind.Fixed)
{
// If this is for a fixed statement, we'll do our own conversion since there are some special cases.
initializerOpt = GenerateConversionForAssignment(declTypeOpt, initializerOpt, diagnostics);
}
}
}
Debug.Assert((object)declTypeOpt != null);
if (kind == LocalDeclarationKind.Fixed)
{
// NOTE: this is an error, but it won't prevent further binding.
if (isVar)
{
if (!hasErrors)
{
Error(diagnostics, ErrorCode.ERR_ImplicitlyTypedLocalCannotBeFixed, declarator);
hasErrors = true;
}
}
if (!declTypeOpt.IsPointerType())
{
if (!hasErrors)
{
Error(diagnostics, ErrorCode.ERR_BadFixedInitType, declarator);
hasErrors = true;
}
}
else if (!IsValidFixedVariableInitializer(declTypeOpt, localSymbol, ref initializerOpt, diagnostics))
{
hasErrors = true;
}
}
if (this.ContainingMemberOrLambda.Kind == SymbolKind.Method
&& ((MethodSymbol)this.ContainingMemberOrLambda).IsAsync
&& declTypeOpt.IsRestrictedType())
{
Error(diagnostics, ErrorCode.ERR_BadSpecialByRefLocal, typeSyntax, declTypeOpt);
hasErrors = true;
}
DeclareLocalVariable(
localSymbol,
declarator.Identifier,
declTypeOpt);
Debug.Assert((object)localSymbol != null);
// It is possible that we have a bracketed argument list, like "int x[];" or "int x[123];"
// in a non-fixed-size-array declaration . This is a common error made by C++ programmers.
// We have already given a good error at parse time telling the user to either make it "fixed"
// or to move the brackets to the type. However, we should still do semantic analysis of
// the arguments, so that errors in them are discovered, hovering over them in the IDE
// gives good results, and so on.
var arguments = default(ImmutableArray<BoundExpression>);
if (declarator.ArgumentList != null)
{
var builder = ArrayBuilder<BoundExpression>.GetInstance();
foreach (var argument in declarator.ArgumentList.Arguments)
{
var boundArgument = BindValue(argument.Expression, diagnostics, BindValueKind.RValue);
builder.Add(boundArgument);
}
arguments = builder.ToImmutableAndFree();
}
if (kind == LocalDeclarationKind.Fixed || kind == LocalDeclarationKind.Using)
{
// CONSIDER: The error message is "you must provide an initializer in a fixed
// CONSIDER: or using declaration". The error message could be targetted to
// CONSIDER: the actual situation. "you must provide an initializer in a
// CONSIDER: 'fixed' declaration."
if (initializerOpt == null)
{
Error(diagnostics, ErrorCode.ERR_FixedMustInit, declarator);
hasErrors = true;
}
}
else if (kind == LocalDeclarationKind.Constant && initializerOpt != null)
{
foreach (var diagnostic in localSymbol.GetConstantValueDiagnostics(initializerOpt))
{
diagnostics.Add(diagnostic);
hasErrors = true;
}
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declTypeOpt);
return new BoundLocalDeclaration(associatedSyntaxNode, localSymbol, boundDeclType, initializerOpt, arguments, hasErrors);
}
private BoundPattern BindDeclarationPattern(
DeclarationPatternSyntax node,
BoundExpression operand,
TypeSymbol operandType,
bool hasErrors,
DiagnosticBag diagnostics)
{
Debug.Assert(operand != null && operandType != (object)null);
var typeSyntax = node.Type;
var identifier = node.Identifier;
bool isVar;
AliasSymbol aliasOpt;
TypeSymbol declType = BindType(typeSyntax, diagnostics, out isVar, out aliasOpt);
if (isVar)
{
declType = operandType;
}
if (declType == (object)null)
{
Debug.Assert(hasErrors);
declType = this.CreateErrorType("var");
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declType);
if (IsOperatorErrors(node, operandType, boundDeclType, diagnostics))
{
hasErrors = true;
}
else
{
hasErrors |= CheckValidPatternType(typeSyntax, operand, operandType, declType,
isVar: isVar, patternTypeWasInSource: true, diagnostics: diagnostics);
}
SourceLocalSymbol localSymbol = this.LookupLocal(identifier);
if (localSymbol != (object)null)
{
if (InConstructorInitializer || InFieldInitializer)
{
Error(diagnostics, ErrorCode.ERR_ExpressionVariableInConstructorOrFieldInitializer, node);
}
localSymbol.SetType(declType);
// Check for variable declaration errors.
hasErrors |= localSymbol.ScopeBinder.ValidateDeclarationNameConflictsInScope(localSymbol, diagnostics);
if (!hasErrors)
{
hasErrors = CheckRestrictedTypeInAsync(this.ContainingMemberOrLambda, declType, diagnostics, typeSyntax);
}
return(new BoundDeclarationPattern(node, localSymbol, boundDeclType, isVar, hasErrors));
}
else
{
// We should have the right binder in the chain for a script or interactive, so we use the field for the pattern.
Debug.Assert(node.SyntaxTree.Options.Kind != SourceCodeKind.Regular);
GlobalExpressionVariable expressionVariableField = LookupDeclaredField(node);
DiagnosticBag tempDiagnostics = DiagnosticBag.GetInstance();
expressionVariableField.SetType(declType, tempDiagnostics);
tempDiagnostics.Free();
BoundExpression receiver = SynthesizeReceiver(node, expressionVariableField, diagnostics);
var variableAccess = new BoundFieldAccess(node, receiver, expressionVariableField, null, hasErrors);
return(new BoundDeclarationPattern(node, expressionVariableField, variableAccess, boundDeclType, isVar, hasErrors));
}
}
private BoundPattern BindDeclarationPattern(
DeclarationPatternSyntax node,
BoundExpression operand,
TypeSymbol operandType,
bool hasErrors,
DiagnosticBag diagnostics)
{
Debug.Assert(operand != null || operandType != (object)null);
if (InConstructorInitializer || InFieldInitializer)
{
Error(diagnostics, ErrorCode.ERR_ExpressionVariableInConstructorOrFieldInitializer, node);
}
var typeSyntax = node.Type;
var identifier = node.Identifier;
bool isVar;
AliasSymbol aliasOpt;
TypeSymbol declType = BindType(typeSyntax, diagnostics, out isVar, out aliasOpt);
if (isVar && operandType != (object)null)
{
declType = operandType;
}
if (declType == (object)null)
{
Debug.Assert(hasErrors);
declType = this.CreateErrorType("var");
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declType);
if (IsOperatorErrors(node, operandType, boundDeclType, diagnostics))
{
hasErrors = true;
}
else
{
hasErrors |= CheckValidPatternType(typeSyntax, operand, operandType, declType,
isVar: isVar, patternTypeWasInSource: true, diagnostics: diagnostics);
}
SourceLocalSymbol localSymbol = this.LookupLocal(identifier);
// In error scenarios with misplaced code, it is possible we can't bind the local declaration.
// This occurs through the semantic model. In that case concoct a plausible result.
if (localSymbol == (object)null)
{
localSymbol = SourceLocalSymbol.MakeLocal(
ContainingMemberOrLambda,
this,
false, // do not allow ref
typeSyntax,
identifier,
LocalDeclarationKind.PatternVariable);
}
localSymbol.SetType(declType);
// Check for variable declaration errors.
hasErrors |= localSymbol.ScopeBinder.ValidateDeclarationNameConflictsInScope(localSymbol, diagnostics);
if (this.ContainingMemberOrLambda.Kind == SymbolKind.Method &&
((MethodSymbol)this.ContainingMemberOrLambda).IsAsync &&
declType.IsRestrictedType() &&
!hasErrors)
{
Error(diagnostics, ErrorCode.ERR_BadSpecialByRefLocal, typeSyntax, declType);
hasErrors = true;
}
return(new BoundDeclarationPattern(node, localSymbol, boundDeclType, isVar, hasErrors));
}
protected BoundLocalDeclaration BindVariableDeclaration(
SourceLocalSymbol localSymbol,
LocalDeclarationKind kind,
bool isVar,
VariableDeclaratorSyntax declarator,
TypeSyntax typeSyntax,
TypeSymbol declTypeOpt,
AliasSymbol aliasOpt,
DiagnosticBag diagnostics,
CSharpSyntaxNode associatedSyntaxNode = null)
{
Debug.Assert(declarator != null);
Debug.Assert((object)declTypeOpt != null || isVar);
Debug.Assert(typeSyntax != null);
var localDiagnostics = DiagnosticBag.GetInstance();
// if we are not given desired syntax, we use declarator
associatedSyntaxNode = associatedSyntaxNode ?? declarator;
bool hasErrors = false;
BoundExpression initializerOpt;
// Check for variable declaration errors.
hasErrors |= this.ValidateDeclarationNameConflictsInScope(localSymbol, localDiagnostics);
EqualsValueClauseSyntax equalsValueClauseSyntax = declarator.Initializer;
if (isVar)
{
aliasOpt = null;
var binder = new ImplicitlyTypedLocalBinder(this, localSymbol);
initializerOpt = binder.BindInferredVariableInitializer(localDiagnostics, equalsValueClauseSyntax, declarator);
// If we got a good result then swap the inferred type for the "var"
if ((object)initializerOpt?.Type != null)
{
declTypeOpt = initializerOpt.Type;
if (declTypeOpt.SpecialType == SpecialType.System_Void)
{
Error(localDiagnostics, ErrorCode.ERR_ImplicitlyTypedVariableAssignedBadValue, declarator, declTypeOpt);
declTypeOpt = CreateErrorType("var");
hasErrors = true;
}
if (!declTypeOpt.IsErrorType())
{
if (declTypeOpt.IsStatic)
{
Error(localDiagnostics, ErrorCode.ERR_VarDeclIsStaticClass, typeSyntax, initializerOpt.Type);
hasErrors = true;
}
}
}
else
{
declTypeOpt = CreateErrorType("var");
hasErrors = true;
}
}
else
{
if (ReferenceEquals(equalsValueClauseSyntax, null))
{
initializerOpt = null;
}
else
{
// Basically inlined BindVariableInitializer, but with conversion optional.
initializerOpt = BindPossibleArrayInitializer(equalsValueClauseSyntax.Value, declTypeOpt, localDiagnostics);
if (kind != LocalDeclarationKind.FixedVariable)
{
// If this is for a fixed statement, we'll do our own conversion since there are some special cases.
initializerOpt = GenerateConversionForAssignment(declTypeOpt, initializerOpt, localDiagnostics);
}
}
}
Debug.Assert((object)declTypeOpt != null);
if (kind == LocalDeclarationKind.FixedVariable)
{
// NOTE: this is an error, but it won't prevent further binding.
if (isVar)
{
if (!hasErrors)
{
Error(localDiagnostics, ErrorCode.ERR_ImplicitlyTypedLocalCannotBeFixed, declarator);
hasErrors = true;
}
}
if (!declTypeOpt.IsPointerType())
{
if (!hasErrors)
{
Error(localDiagnostics, ErrorCode.ERR_BadFixedInitType, declarator);
hasErrors = true;
}
}
else if (!IsValidFixedVariableInitializer(declTypeOpt, localSymbol, ref initializerOpt, localDiagnostics))
{
hasErrors = true;
}
}
if (this.ContainingMemberOrLambda.Kind == SymbolKind.Method
&& ((MethodSymbol)this.ContainingMemberOrLambda).IsAsync
&& declTypeOpt.IsRestrictedType())
{
Error(localDiagnostics, ErrorCode.ERR_BadSpecialByRefLocal, typeSyntax, declTypeOpt);
hasErrors = true;
}
DeclareLocalVariable(
localSymbol,
declarator.Identifier,
declTypeOpt);
Debug.Assert((object)localSymbol != null);
ImmutableArray<BoundExpression> arguments = BindDeclaratorArguments(declarator, localDiagnostics);
if (kind == LocalDeclarationKind.FixedVariable || kind == LocalDeclarationKind.UsingVariable)
{
// CONSIDER: The error message is "you must provide an initializer in a fixed
// CONSIDER: or using declaration". The error message could be targetted to
// CONSIDER: the actual situation. "you must provide an initializer in a
// CONSIDER: 'fixed' declaration."
if (initializerOpt == null)
{
Error(localDiagnostics, ErrorCode.ERR_FixedMustInit, declarator);
hasErrors = true;
}
}
else if (kind == LocalDeclarationKind.Constant && initializerOpt != null && !localDiagnostics.HasAnyResolvedErrors())
{
var constantValueDiagnostics = localSymbol.GetConstantValueDiagnostics(initializerOpt);
foreach (var diagnostic in constantValueDiagnostics)
{
diagnostics.Add(diagnostic);
hasErrors = true;
}
}
diagnostics.AddRangeAndFree(localDiagnostics);
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declTypeOpt);
return new BoundLocalDeclaration(associatedSyntaxNode, localSymbol, boundDeclType, initializerOpt, arguments, hasErrors);
}
private BoundForEachStatement BindForEachPartsWorker(DiagnosticBag diagnostics, Binder originalBinder)
{
// Use the right binder to avoid seeing iteration variable
BoundExpression collectionExpr = originalBinder.GetBinder(_syntax.Expression).BindValue(_syntax.Expression, diagnostics, BindValueKind.RValue);
ForEachEnumeratorInfo.Builder builder = new ForEachEnumeratorInfo.Builder();
TypeSymbol inferredType;
bool hasErrors = !GetEnumeratorInfoAndInferCollectionElementType(ref builder, ref collectionExpr, diagnostics, out inferredType);
// These should only occur when special types are missing or malformed.
hasErrors = hasErrors ||
(object)builder.GetEnumeratorMethod == null ||
(object)builder.MoveNextMethod == null ||
(object)builder.CurrentPropertyGetter == null;
// Check for local variable conflicts in the *enclosing* binder; obviously the *current*
// binder has a local that matches!
var hasNameConflicts = originalBinder.ValidateDeclarationNameConflictsInScope(IterationVariable, diagnostics);
// If the type in syntax is "var", then the type should be set explicitly so that the
// Type property doesn't fail.
TypeSyntax typeSyntax = _syntax.Type;
bool isVar;
AliasSymbol alias;
TypeSymbol declType = BindType(typeSyntax, diagnostics, out isVar, out alias);
TypeSymbol iterationVariableType;
if (isVar)
{
iterationVariableType = inferredType ?? CreateErrorType("var");
}
else
{
Debug.Assert((object)declType != null);
iterationVariableType = declType;
}
BoundTypeExpression boundIterationVariableType = new BoundTypeExpression(typeSyntax, alias, iterationVariableType);
this.IterationVariable.SetTypeSymbol(iterationVariableType);
BoundStatement body = originalBinder.BindPossibleEmbeddedStatement(_syntax.Statement, diagnostics);
hasErrors = hasErrors || iterationVariableType.IsErrorType();
// Skip the conversion checks and array/enumerator differentiation if we know we have an error (except local name conflicts).
if (hasErrors)
{
return new BoundForEachStatement(
_syntax,
null, // can't be sure that it's complete
default(Conversion),
boundIterationVariableType,
this.IterationVariable,
collectionExpr,
body,
CheckOverflowAtRuntime,
this.BreakLabel,
this.ContinueLabel,
hasErrors);
}
hasErrors |= hasNameConflicts;
var foreachKeyword = _syntax.ForEachKeyword;
ReportDiagnosticsIfObsolete(diagnostics, builder.GetEnumeratorMethod, foreachKeyword, hasBaseReceiver: false);
ReportDiagnosticsIfObsolete(diagnostics, builder.MoveNextMethod, foreachKeyword, hasBaseReceiver: false);
ReportDiagnosticsIfObsolete(diagnostics, builder.CurrentPropertyGetter, foreachKeyword, hasBaseReceiver: false);
ReportDiagnosticsIfObsolete(diagnostics, builder.CurrentPropertyGetter.AssociatedSymbol, foreachKeyword, hasBaseReceiver: false);
// We want to convert from inferredType in the array/string case and builder.ElementType in the enumerator case,
// but it turns out that these are equivalent (when both are available).
HashSet<DiagnosticInfo> useSiteDiagnostics = null;
Conversion elementConversion = this.Conversions.ClassifyConversionForCast(inferredType, iterationVariableType, ref useSiteDiagnostics);
if (!elementConversion.IsValid)
{
ImmutableArray<MethodSymbol> originalUserDefinedConversions = elementConversion.OriginalUserDefinedConversions;
if (originalUserDefinedConversions.Length > 1)
{
diagnostics.Add(ErrorCode.ERR_AmbigUDConv, _syntax.ForEachKeyword.GetLocation(), originalUserDefinedConversions[0], originalUserDefinedConversions[1], inferredType, iterationVariableType);
}
else
{
SymbolDistinguisher distinguisher = new SymbolDistinguisher(this.Compilation, inferredType, iterationVariableType);
diagnostics.Add(ErrorCode.ERR_NoExplicitConv, _syntax.ForEachKeyword.GetLocation(), distinguisher.First, distinguisher.Second);
}
hasErrors = true;
}
else
{
ReportDiagnosticsIfObsolete(diagnostics, elementConversion, _syntax.ForEachKeyword, hasBaseReceiver: false);
}
// Spec (§8.8.4):
// If the type X of expression is dynamic then there is an implicit conversion from >>expression<< (not the type of the expression)
// to the System.Collections.IEnumerable interface (§6.1.8).
builder.CollectionConversion = this.Conversions.ClassifyConversionFromExpression(collectionExpr, builder.CollectionType, ref useSiteDiagnostics);
builder.CurrentConversion = this.Conversions.ClassifyConversion(builder.CurrentPropertyGetter.ReturnType, builder.ElementType, ref useSiteDiagnostics);
builder.EnumeratorConversion = this.Conversions.ClassifyConversion(builder.GetEnumeratorMethod.ReturnType, GetSpecialType(SpecialType.System_Object, diagnostics, _syntax), ref useSiteDiagnostics);
diagnostics.Add(_syntax.ForEachKeyword.GetLocation(), useSiteDiagnostics);
// Due to the way we extracted the various types, these conversions should always be possible.
// CAVEAT: if we're iterating over an array of pointers, the current conversion will fail since we
// can't convert from object to a pointer type. Similarly, if we're iterating over an array of
// Nullable<Error>, the current conversion will fail because we don't know if an ErrorType is a
// value type. This doesn't matter in practice, since we won't actually use the enumerator pattern
// when we lower the loop.
Debug.Assert(builder.CollectionConversion.IsValid);
Debug.Assert(builder.CurrentConversion.IsValid ||
(builder.ElementType.IsPointerType() && collectionExpr.Type.IsArray()) ||
(builder.ElementType.IsNullableType() && builder.ElementType.GetMemberTypeArgumentsNoUseSiteDiagnostics().Single().IsErrorType() && collectionExpr.Type.IsArray()));
Debug.Assert(builder.EnumeratorConversion.IsValid ||
this.Compilation.GetSpecialType(SpecialType.System_Object).TypeKind == TypeKind.Error ||
!useSiteDiagnostics.IsNullOrEmpty(),
"Conversions to object succeed unless there's a problem with the object type or the source type");
// If user-defined conversions could occur here, we would need to check for ObsoleteAttribute.
Debug.Assert((object)builder.CollectionConversion.Method == null,
"Conversion from collection expression to collection type should not be user-defined");
Debug.Assert((object)builder.CurrentConversion.Method == null,
"Conversion from Current property type to element type should not be user-defined");
Debug.Assert((object)builder.EnumeratorConversion.Method == null,
"Conversion from GetEnumerator return type to System.Object should not be user-defined");
// We're wrapping the collection expression in a (non-synthesized) conversion so that its converted
// type (i.e. builder.CollectionType) will be available in the binding API.
BoundConversion convertedCollectionExpression = new BoundConversion(
collectionExpr.Syntax,
collectionExpr,
builder.CollectionConversion,
CheckOverflowAtRuntime,
false,
ConstantValue.NotAvailable,
builder.CollectionType);
return new BoundForEachStatement(
_syntax,
builder.Build(this.Flags),
elementConversion,
boundIterationVariableType,
this.IterationVariable,
convertedCollectionExpression,
body,
CheckOverflowAtRuntime,
this.BreakLabel,
this.ContinueLabel,
hasErrors);
}
private bool IsOperatorErrors(CSharpSyntaxNode node, TypeSymbol operandType, BoundTypeExpression typeExpression, DiagnosticBag diagnostics)
{
var targetType = typeExpression.Type;
var targetTypeKind = targetType.TypeKind;
// The native compiler allows "x is C" where C is a static class. This
// is strictly illegal according to the specification (see the section
// called "Referencing Static Class Types".) To retain compatibility we
// allow it, but when /feature:strict is enabled we break with the native
// compiler and turn this into an error, as it should be.
if (targetType.IsStatic && Compilation.FeatureStrictEnabled)
{
Error(diagnostics, ErrorCode.ERR_StaticInAsOrIs, node, targetType);
return true;
}
if ((object)operandType != null && operandType.TypeKind == TypeKind.Pointer || targetTypeKind == TypeKind.Pointer)
{
// operand for an is or as expression cannot be of pointer type
Error(diagnostics, ErrorCode.ERR_PointerInAsOrIs, node);
return true;
}
return targetTypeKind == TypeKind.Error;
}
private BoundExpression MakeIsOperator(
BoundIsOperator oldNode,
SyntaxNode 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 = MakeConversionNode(
syntax: rewrittenOperand.Syntax,
rewrittenOperand: rewrittenOperand,
conversion: Conversion.Boxing,
rewrittenType: _compilation.GetSpecialType(SpecialType.System_Object),
@checked: false);
}
return(MakeNullCheck(syntax, rewrittenOperand, BinaryOperatorKind.NotEqual));
}
}
return(oldNode.Update(rewrittenOperand, rewrittenTargetType, conversion, rewrittenType));
}
private BoundExpression BindAsOperator(BinaryExpressionSyntax node, DiagnosticBag diagnostics)
{
var operand = BindValue(node.Left, diagnostics, BindValueKind.RValue);
AliasSymbol alias;
var targetType = BindType(node.Right, diagnostics, out alias);
var typeExpression = new BoundTypeExpression(node.Right, alias, targetType);
var targetTypeKind = targetType.TypeKind;
var resultType = targetType;
// Is and As operator should have null ConstantValue as they are not constant expressions.
// However we perform analysis of is/as expressions at bind time to detect if the expression
// will always evaluate to a constant to generate warnings (always true/false/null).
// We also need this analysis result during rewrite to optimize away redundant isinst instructions.
// We store the conversion kind from expression's operand type to target type to enable these
// optimizations during is/as operator rewrite.
switch (operand.Kind)
{
case BoundKind.UnboundLambda:
case BoundKind.Lambda:
case BoundKind.MethodGroup: // New in Roslyn - see DevDiv #864740.
// operand for an is or as expression cannot be a lambda expression or method group
if (!operand.HasAnyErrors)
{
Error(diagnostics, ErrorCode.ERR_LambdaInIsAs, node);
}
return new BoundAsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
if (operand.HasAnyErrors || targetTypeKind == TypeKind.Error)
{
// If either operand is bad or target type has errors, bail out preventing more cascading errors.
return new BoundAsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
// SPEC: In an operation of the form E as T, E must be an expression and T must be a
// SPEC: reference type, a type parameter known to be a reference type, or a nullable type.
if (!targetType.IsReferenceType && !targetType.IsNullableType())
{
// target type for an as expression cannot be a non-nullable value type.
// generate appropriate error
if (targetTypeKind == TypeKind.TypeParameter)
{
Error(diagnostics, ErrorCode.ERR_AsWithTypeVar, node, targetType);
}
else if (targetTypeKind == TypeKind.Pointer)
{
Error(diagnostics, ErrorCode.ERR_PointerInAsOrIs, node);
}
else
{
Error(diagnostics, ErrorCode.ERR_AsMustHaveReferenceType, node, targetType);
}
return new BoundAsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
// The C# specification states in the section called
// "Referencing Static Class Types" that it is always
// illegal to use "as" with a static type. The
// native compiler actually allows "null as C" for
// a static type C to be an expression of type C.
// It also allows "someObject as C" if "someObject"
// is of type object. To retain compatibility we
// allow it, but when /feature:strict is enabled we break with the native
// compiler and turn this into an error, as it should be.
if (targetType.IsStatic && Compilation.FeatureStrictEnabled)
{
Error(diagnostics, ErrorCode.ERR_StaticInAsOrIs, node, targetType);
return new BoundAsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
if (operand.IsLiteralNull())
{
// We do not want to warn for the case "null as TYPE" where the null
// is a literal, because the user might be saying it to cause overload resolution
// to pick a particular method
return new BoundAsOperator(node, operand, typeExpression, Conversion.NullLiteral, resultType);
}
if (operand.Kind == BoundKind.MethodGroup)
{
Error(diagnostics, ErrorCode.ERR_NoExplicitBuiltinConv, node, MessageID.IDS_MethodGroup.Localize(), targetType);
return new BoundAsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
var operandType = operand.Type;
Debug.Assert((object)operandType != null);
var operandTypeKind = operandType.TypeKind;
Debug.Assert(targetTypeKind != TypeKind.Pointer, "Should have been caught above");
if (operandTypeKind == TypeKind.Pointer)
{
// operand for an is or as expression cannot be of pointer type
Error(diagnostics, ErrorCode.ERR_PointerInAsOrIs, node);
return new BoundAsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
if (operandTypeKind == TypeKind.Dynamic)
{
// if operand has a dynamic type, we do the same thing as though it were an object
operandType = GetSpecialType(SpecialType.System_Object, diagnostics, node);
operandTypeKind = operandType.TypeKind;
}
if (targetTypeKind == TypeKind.Dynamic)
{
// for "as dynamic", we do the same thing as though it were an "as object"
targetType = GetSpecialType(SpecialType.System_Object, diagnostics, node);
targetTypeKind = targetType.TypeKind;
}
HashSet<DiagnosticInfo> useSiteDiagnostics = null;
Conversion conversion = Conversions.ClassifyConversion(operandType, targetType, ref useSiteDiagnostics, builtinOnly: true);
diagnostics.Add(node, useSiteDiagnostics);
bool hasErrors = ReportAsOperatorConversionDiagnostics(node, diagnostics, this.Compilation, operandType, targetType, conversion.Kind, operand.ConstantValue);
return new BoundAsOperator(node, operand, typeExpression, conversion, resultType, hasErrors);
}
private BoundExpression BindIsOperator(BinaryExpressionSyntax node, DiagnosticBag diagnostics)
{
var operand = BindValue(node.Left, diagnostics, BindValueKind.RValue);
AliasSymbol alias;
TypeSymbol targetType = BindType(node.Right, diagnostics, out alias);
var typeExpression = new BoundTypeExpression(node.Right, alias, targetType);
var targetTypeKind = targetType.TypeKind;
var resultType = (TypeSymbol)GetSpecialType(SpecialType.System_Boolean, diagnostics, node);
// Is and As operator should have null ConstantValue as they are not constant expressions.
// However we perform analysis of is/as expressions at bind time to detect if the expression
// will always evaluate to a constant to generate warnings (always true/false/null).
// We also need this analysis result during rewrite to optimize away redundant isinst instructions.
// We store the conversion from expression's operand type to target type to enable these
// optimizations during is/as operator rewrite.
switch (operand.Kind)
{
case BoundKind.UnboundLambda:
case BoundKind.Lambda:
case BoundKind.MethodGroup: // New in Roslyn - see DevDiv #864740.
// operand for an is or as expression cannot be a lambda expression or method group
Error(diagnostics, ErrorCode.ERR_LambdaInIsAs, node);
return new BoundIsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
if (operand.HasAnyErrors || targetTypeKind == TypeKind.Error)
{
// If either operand is bad or target type has errors, bail out preventing more cascading errors.
return new BoundIsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
// The native compiler allows "x is C" where C is a static class. This
// is strictly illegal according to the specification (see the section
// called "Referencing Static Class Types".) To retain compatibility we
// allow it, but when /feature:strict is enabled we break with the native
// compiler and turn this into an error, as it should be.
if (targetType.IsStatic && Compilation.FeatureStrictEnabled)
{
Error(diagnostics, ErrorCode.ERR_StaticInAsOrIs, node, targetType);
return new BoundIsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
var operandType = operand.Type;
if ((object)operandType != null && operandType.TypeKind == TypeKind.Pointer || targetTypeKind == TypeKind.Pointer)
{
// operand for an is or as expression cannot be of pointer type
Error(diagnostics, ErrorCode.ERR_PointerInAsOrIs, node);
return new BoundIsOperator(node, operand, typeExpression, Conversion.NoConversion, resultType, hasErrors: true);
}
HashSet<DiagnosticInfo> useSiteDiagnostics = null;
if (operand.ConstantValue == ConstantValue.Null ||
operand.Kind == BoundKind.MethodGroup ||
operandType.SpecialType == SpecialType.System_Void)
{
// warning for cases where the result is always false:
// (a) "null is TYPE" OR operand evaluates to null
// (b) operand is a MethodGroup
// (c) operand is of void type
// NOTE: Dev10 violates the SPEC for case (c) above and generates
// NOTE: an error ERR_NoExplicitBuiltinConv if the target type
// NOTE: is an open type. According to the specification, the result
// NOTE: is always false, but no compile time error occurs.
// NOTE: We follow the specification and generate WRN_IsAlwaysFalse
// NOTE: instead of an error.
// NOTE: See Test SyntaxBinderTests.TestIsOperatorWithTypeParameter
Error(diagnostics, ErrorCode.WRN_IsAlwaysFalse, node, targetType);
Conversion conv = Conversions.ClassifyConversionFromExpression(operand, targetType, ref useSiteDiagnostics);
diagnostics.Add(node, useSiteDiagnostics);
return new BoundIsOperator(node, operand, typeExpression, conv, resultType);
}
if (targetTypeKind == TypeKind.Dynamic)
{
// warning for dynamic target type
Error(diagnostics, ErrorCode.WRN_IsDynamicIsConfusing,
node, node.OperatorToken.Text, targetType.Name,
GetSpecialType(SpecialType.System_Object, diagnostics, node).Name // a pretty way of getting the string "Object"
);
}
Debug.Assert((object)operandType != null);
if (operandType.TypeKind == TypeKind.Dynamic)
{
// if operand has a dynamic type, we do the same thing as though it were an object
operandType = GetSpecialType(SpecialType.System_Object, diagnostics, node);
}
Conversion conversion = Conversions.ClassifyConversion(operandType, targetType, ref useSiteDiagnostics);
diagnostics.Add(node, useSiteDiagnostics);
ReportIsOperatorConstantWarnings(node, diagnostics, operandType, targetType, conversion.Kind, operand.ConstantValue);
return new BoundIsOperator(node, operand, typeExpression, conversion, resultType);
}
public BoundForEachStatement(SyntaxNode syntax, ForEachEnumeratorInfo enumeratorInfoOpt, Conversion elementConversion, BoundTypeExpression iterationVariableType, ImmutableArray <LocalSymbol> iterationVariables, BoundExpression expression, BoundForEachDeconstructStep deconstructionOpt, BoundStatement body, bool @checked, GeneratedLabelSymbol breakLabel, GeneratedLabelSymbol continueLabel, bool hasErrors = false) :
this(syntax, enumeratorInfoOpt, elementConversion, iterationVariableType, iterationVariables, iterationErrorExpressionOpt : null, expression, deconstructionOpt, body, @checked, breakLabel, continueLabel, hasErrors)
{
}
public BoundExpression VisitDynamicInvocation(BoundDynamicInvocation node, bool resultDiscarded)
{
var loweredArguments = VisitList(node.Arguments);
bool hasImplicitReceiver;
BoundExpression loweredReceiver;
ImmutableArray <TypeSymbol> typeArguments;
string name;
switch (node.Expression.Kind)
{
case BoundKind.MethodGroup:
// method invocation
BoundMethodGroup methodGroup = (BoundMethodGroup)node.Expression;
typeArguments = methodGroup.TypeArgumentsOpt;
name = methodGroup.Name;
hasImplicitReceiver = (methodGroup.Flags & BoundMethodGroupFlags.HasImplicitReceiver) != 0;
// Should have been eliminated during binding of dynamic invocation:
Debug.Assert(methodGroup.ReceiverOpt == null || methodGroup.ReceiverOpt.Kind != BoundKind.TypeOrValueExpression);
if (methodGroup.ReceiverOpt == null)
{
// Calling a static method defined on an outer class via its simple name.
NamedTypeSymbol firstContainer = node.ApplicableMethods.First().ContainingType;
Debug.Assert(node.ApplicableMethods.All(m => m.IsStatic && m.ContainingType == firstContainer));
loweredReceiver = new BoundTypeExpression(node.Syntax, null, firstContainer);
}
else if (hasImplicitReceiver && factory.TopLevelMethod.IsStatic)
{
// Calling a static method defined on the current class via its simple name.
loweredReceiver = new BoundTypeExpression(node.Syntax, null, factory.CurrentClass);
}
else
{
loweredReceiver = VisitExpression(methodGroup.ReceiverOpt);
}
// If we are calling a method on a NoPIA type, we need to embed all methods/properties
// with the matching name of this dynamic invocation.
EmbedIfNeedTo(loweredReceiver, methodGroup.Methods, node.Syntax);
break;
case BoundKind.DynamicMemberAccess:
// method invocation
var memberAccess = (BoundDynamicMemberAccess)node.Expression;
name = memberAccess.Name;
typeArguments = memberAccess.TypeArgumentsOpt;
loweredReceiver = VisitExpression(memberAccess.Receiver);
hasImplicitReceiver = false;
break;
default:
// delegate invocation
var loweredExpression = VisitExpression(node.Expression);
return(dynamicFactory.MakeDynamicInvocation(loweredExpression, loweredArguments, node.ArgumentNamesOpt, node.ArgumentRefKindsOpt, resultDiscarded).ToExpression());
}
Debug.Assert(loweredReceiver != null);
return(dynamicFactory.MakeDynamicMemberInvocation(
name,
loweredReceiver,
typeArguments,
loweredArguments,
node.ArgumentNamesOpt,
node.ArgumentRefKindsOpt,
hasImplicitReceiver,
resultDiscarded).ToExpression());
}