private ReferenceRewriter(
SemanticModel semanticModel,
VariableDeclaratorSyntax variableDeclarator,
ExpressionSyntax expressionToInline,
CancellationToken cancellationToken)
{
_semanticModel = semanticModel;
_localSymbol = (ILocalSymbol)semanticModel.GetDeclaredSymbol(variableDeclarator, cancellationToken);
_variableDeclarator = variableDeclarator;
_expressionToInline = expressionToInline;
_cancellationToken = cancellationToken;
}
private static SyntaxNode CreateRootAddingDisposeToEndOfMethod(SyntaxNode root, ExpressionStatementSyntax statement, ILocalSymbol identitySymbol)
{
var method = statement.FirstAncestorOrSelf<MethodDeclarationSyntax>();
var newDispose = ImplementsDisposableExplicitly(identitySymbol.Type)
? SyntaxFactory.ExpressionStatement(SyntaxFactory.InvocationExpression(
SyntaxFactory.MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression,
SyntaxFactory.ParenthesizedExpression(SyntaxFactory.CastExpression(SyntaxFactory.ParseName("System.IDisposable").WithAdditionalAnnotations(Simplifier.Annotation), SyntaxFactory.IdentifierName(identitySymbol.Name))),
SyntaxFactory.IdentifierName("Dispose"))))
: SyntaxFactory.ParseStatement($"{identitySymbol.Name}.Dispose();");
newDispose = newDispose.WithAdditionalAnnotations(Formatter.Annotation);
var last = method.Body.Statements.Last();
var newRoot = root.InsertNodesAfter(method.Body.Statements.Last(), new[] { newDispose });
return newRoot;
}
private static bool IsDisposedOrAssigned(SemanticModel semanticModel, SyntaxNode node, ILocalSymbol identitySymbol)
{
var method = node.FirstAncestorOrSelf<MethodDeclarationSyntax>();
if (method == null) return false;
if (IsReturned(method, semanticModel, identitySymbol)) return true;
foreach (var statement in method.Body.DescendantNodes().OfType<StatementSyntax>())
{
if (statement.SpanStart > node.SpanStart
&& (IsCorrectDispose(statement as ExpressionStatementSyntax, semanticModel, identitySymbol)
|| IsAssignedToField(statement as ExpressionStatementSyntax, semanticModel, identitySymbol)))
return true;
}
return false;
}
/// <summary>
/// Creates a new LocalDefinition.
/// </summary>
/// <param name="symbolOpt">Local symbol, used by edit and continue only, null otherwise.</param>
/// <param name="nameOpt">Name associated with the slot.</param>
/// <param name="type">Type associated with the slot.</param>
/// <param name="slot">Slot position in the signature.</param>
/// <param name="synthesizedKind">Local kind.</param>
/// <param name="id">Local id.</param>
/// <param name="pdbAttributes">Value to emit in the attributes field in the PDB.</param>
/// <param name="constraints">Specifies whether slot type should have pinned modifier and whether slot should have byref constraint.</param>
/// <param name="dynamicTransformFlags">The synthesized dynamic attributes of the local.</param>
/// <param name="tupleElementNames">Tuple element names of the local.</param>
public LocalDefinition(
ILocalSymbol symbolOpt,
string nameOpt,
Cci.ITypeReference type,
int slot,
SynthesizedLocalKind synthesizedKind,
LocalDebugId id,
LocalVariableAttributes pdbAttributes,
LocalSlotConstraints constraints,
ImmutableArray<TypedConstant> dynamicTransformFlags,
ImmutableArray<TypedConstant> tupleElementNames)
{
_symbolOpt = symbolOpt;
_nameOpt = nameOpt;
_type = type;
_slot = slot;
_slotInfo = new LocalSlotDebugInfo(synthesizedKind, id);
_pdbAttributes = pdbAttributes;
_dynamicTransformFlags = dynamicTransformFlags.NullToEmpty();
_tupleElementNames = tupleElementNames.NullToEmpty();
_constraints = constraints;
}
/// <summary>
/// Creates a new LocalDefinition.
/// </summary>
/// <param name="symbolOpt">Local symbol, used by edit and continue only, null otherwise.</param>
/// <param name="nameOpt">Name associated with the slot.</param>
/// <param name="type">Type associated with the slot.</param>
/// <param name="slot">Slot position in the signature.</param>
/// <param name="dynamicTransformFlags">Contains the synthesized dynamic attributes of the local</param>
/// <param name="synthesizedKind">Local kind.</param>
/// <param name="id">Local id.</param>
/// <param name="pdbAttributes">Value to emit in the attributes field in the PDB.</param>
/// <param name="constraints">Specifies whether slot type should have pinned modifier and whether slot should have byref constraint.</param>
/// <param name="isDynamic">Specifies if the type is Dynamic.</param>
public LocalDefinition(
ILocalSymbol symbolOpt,
string nameOpt,
Cci.ITypeReference type,
int slot,
SynthesizedLocalKind synthesizedKind,
LocalDebugId id,
uint pdbAttributes,
LocalSlotConstraints constraints,
bool isDynamic,
ImmutableArray<TypedConstant> dynamicTransformFlags)
{
_symbolOpt = symbolOpt;
_nameOpt = nameOpt;
_type = type;
_slot = slot;
_slotInfo = new LocalSlotDebugInfo(synthesizedKind, id);
_pdbAttributes = pdbAttributes;
_dynamicTransformFlags = dynamicTransformFlags;
_constraints = constraints;
_isDynamic = isDynamic;
}
public override void VisitLocal(ILocalSymbol symbol)
{
symbol.Type.Accept(this);
}
private static bool IsPassedAsArgument(StatementSyntax statement, SemanticModel semanticModel, ILocalSymbol identitySymbol)
{
if (statement == null) return false;
var args = statement.DescendantNodes().OfKind<ArgumentSyntax>(SyntaxKind.Argument);
foreach (var arg in args)
{
var argSymbol = semanticModel.GetSymbolInfo(arg.Expression).Symbol;
if (identitySymbol.Equals(argSymbol)) return true;
}
return false;
}
private bool LocalsAreEquivalent(ILocalSymbol x, ILocalSymbol y)
{
return(HaveSameLocation(x, y));
}
private static bool IsDisposableLocalSymbol(ILocalSymbol localSymbol)
{
return(localSymbol != null &&
DisposableMemberInNonDisposableClass.ImplementsIDisposable(localSymbol.Type as INamedTypeSymbol));
}
public static ExpressionSyntax Visit(ExpressionSyntax initializer, ILocalSymbol local, SemanticModel semanticModel)
{
var simplifier = new InitializerRewriter(initializer, local, semanticModel);
return (ExpressionSyntax)simplifier.Visit(initializer);
}
/// <summary> /// Gets the annotated type of an ILocalSymbol. /// This has not yet been exposed on the public API. /// </summary> public static AnnotatedTypeSymbol GetAnnotatedType(this ILocalSymbol symbol) => new AnnotatedTypeSymbol(symbol.Type, symbol.NullableAnnotation);
public override void VisitLocal(ILocalSymbol symbol)
{
base.VisitLocal(symbol);
}
protected abstract TLocalDeclarationStatementSyntax GetUpdatedLocalDeclarationStatement(SyntaxGenerator generator, TLocalDeclarationStatementSyntax localDeclarationStatement, ILocalSymbol symbol);
private int CombineHashCodes(ILocalSymbol x, int currentHash)
{
return(Hash.Combine(x.Locations.FirstOrDefault(), currentHash));
}
private static bool IsReturned(ILocalSymbol symbol, BlockSyntax block, SemanticModel semanticModel, CancellationToken cancellationToken)
{
using (var pooled = ReturnValueWalker.Create(block, Search.TopLevel, semanticModel, cancellationToken))
{
foreach (var value in pooled.Item)
{
var returnedSymbol = semanticModel.GetSymbolSafe(value, cancellationToken);
if (SymbolComparer.Equals(symbol, returnedSymbol))
{
return(true);
}
if (value is ObjectCreationExpressionSyntax objectCreation)
{
if (objectCreation.ArgumentList != null)
{
foreach (var argument in objectCreation.ArgumentList.Arguments)
{
var arg = semanticModel.GetSymbolSafe(argument.Expression, cancellationToken);
if (SymbolComparer.Equals(symbol, arg))
{
return(true);
}
}
}
if (objectCreation.Initializer != null)
{
foreach (var argument in objectCreation.Initializer.Expressions)
{
var arg = semanticModel.GetSymbolSafe(argument, cancellationToken);
if (SymbolComparer.Equals(symbol, arg))
{
return(true);
}
}
}
}
if (value is InvocationExpressionSyntax invocation)
{
if (returnedSymbol == KnownSymbol.RxDisposable.Create &&
invocation.ArgumentList != null &&
invocation.ArgumentList.Arguments.TryGetSingle(out ArgumentSyntax argument))
{
var body = (argument.Expression as ParenthesizedLambdaExpressionSyntax)?.Body;
using (var pooledInvocations = InvocationWalker.Create(body))
{
foreach (var candidate in pooledInvocations.Item.Invocations)
{
if (Disposable.IsDisposing(candidate, symbol, semanticModel, cancellationToken))
{
return(true);
}
}
}
}
}
}
}
return(false);
}
public static IVariableDeclaration CreateVariableDeclaration(ILocalSymbol variable, IVariableInitializer initializer, SemanticModel semanticModel, SyntaxNode syntax)
{
return(CreateVariableDeclaration(ImmutableArray.Create(variable), initializer, semanticModel, syntax));
}
private static IEnumerable <int> GetAssignedIndexes(IEnumerable <StatementSyntax> statements, ILocalSymbol symbol, SemanticModel semanticModel)
{
foreach (var statement in statements)
{
var assignment = statement as AssignmentStatementSyntax;
if (assignment == null)
{
yield break;
}
var invocation = assignment.Left as InvocationExpressionSyntax;
if (invocation?.ArgumentList == null ||
invocation.ArgumentList.Arguments.Count != 1)
{
yield break;
}
var assignedSymbol = semanticModel.GetSymbolInfo(invocation.Expression).Symbol;
if (!symbol.Equals(assignedSymbol))
{
yield break;
}
var argument = invocation.ArgumentList.Arguments.First();
var index = GetConstantArgumentValue(argument, semanticModel);
if (!index.HasValue)
{
yield break;
}
yield return(index.Value);
}
}
public sealed override void VisitLocal(ILocalSymbol symbol)
{
Visit(symbol.Type);
Visit(symbol.ContainingSymbol);
}
private async Task<IEnumerable<SymbolDisplayPart>> GetLocalPartsAsync(ILocalSymbol symbol)
{
if (symbol.IsConst)
{
var initializerParts = await GetInitializerSourcePartsAsync(symbol).ConfigureAwait(false);
if (initializerParts != null)
{
var parts = ToMinimalDisplayParts(symbol, MinimallyQualifiedFormat).ToList();
parts.AddRange(Space());
parts.AddRange(Punctuation("="));
parts.AddRange(Space());
parts.AddRange(initializerParts);
return parts;
}
}
return ToMinimalDisplayParts(symbol, MinimallyQualifiedFormatWithConstants);
}
private static SyntaxNode CreateRootAddingDisposeToEndOfMethod(SyntaxNode root, ExpressionStatementSyntax statement, ILocalSymbol identitySymbol)
{
var method = statement.FirstAncestorOrSelf <MethodDeclarationSyntax>();
var newDispose = ImplementsDisposableExplicitly(identitySymbol.Type)
? SyntaxFactory.ExpressionStatement(SyntaxFactory.InvocationExpression(
SyntaxFactory.MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression,
SyntaxFactory.ParenthesizedExpression(SyntaxFactory.CastExpression(SyntaxFactory.ParseName("System.IDisposable").WithAdditionalAnnotations(Simplifier.Annotation), SyntaxFactory.IdentifierName(identitySymbol.Name))),
SyntaxFactory.IdentifierName("Dispose"))))
: SyntaxFactory.ParseStatement($"{identitySymbol.Name}.Dispose();");
newDispose = newDispose.WithAdditionalAnnotations(Formatter.Annotation);
var last = method.Body.Statements.Last();
var newRoot = root.InsertNodesAfter(method.Body.Statements.Last(), new[] { newDispose });
return(newRoot);
}
public override void VisitLocal(ILocalSymbol symbol)
{
VisitAttributes(symbol);
symbol.Type.Accept(this);
}
private static bool IsAssignedToField(ExpressionStatementSyntax expressionStatement, SemanticModel semanticModel, ILocalSymbol identitySymbol)
{
if (expressionStatement == null) return false;
if (!expressionStatement.Expression.IsKind(SyntaxKind.SimpleAssignmentExpression)) return false;
var assignment = (AssignmentExpressionSyntax)expressionStatement.Expression;
var assignmentTarget = semanticModel.GetSymbolInfo(assignment.Left).Symbol;
if (assignmentTarget?.Kind != SymbolKind.Field) return false;
var assignmentSource = semanticModel.GetSymbolInfo(assignment.Right).Symbol;
return (identitySymbol.Equals(assignmentSource));
}
private void AnalyzeSyntaxNode(SyntaxNodeAnalysisContext context)
{
if (GeneratedCodeAnalyzer?.IsGeneratedCode(context) == true)
{
return;
}
var catchClause = (CatchClauseSyntax)context.Node;
if (catchClause.Declaration == null || catchClause.Block == null)
{
return;
}
ILocalSymbol symbol = context
.SemanticModel
.GetDeclaredSymbol(catchClause.Declaration, context.CancellationToken);
if (symbol != null)
{
foreach (SyntaxNode node in catchClause.Block.DescendantNodes(f => !f.IsKind(SyntaxKind.CatchClause)))
{
if (node.IsKind(SyntaxKind.ThrowStatement))
{
var throwStatement = (ThrowStatementSyntax)node;
if (throwStatement.Expression != null)
{
ISymbol expressionSymbol = context
.SemanticModel
.GetSymbolInfo(throwStatement.Expression, context.CancellationToken)
.Symbol;
if (expressionSymbol != null &&
symbol.Equals(expressionSymbol))
{
context.ReportDiagnostic(
DiagnosticDescriptors.RemoveOriginalExceptionFromThrowStatement,
throwStatement.Expression.GetLocation());
}
}
}
}
}
if (catchClause.Declaration.Type != null &&
catchClause.Block.Statements.Count == 0)
{
ITypeSymbol typeSymbol = context
.SemanticModel
.GetTypeInfo(catchClause.Declaration.Type, context.CancellationToken)
.Type;
if (typeSymbol != null)
{
INamedTypeSymbol exceptionTypeSymbol = context.GetTypeByMetadataName("System.Exception");
if (typeSymbol.Equals(exceptionTypeSymbol))
{
context.ReportDiagnostic(
DiagnosticDescriptors.AvoidEmptyCatchClauseThatCatchesSystemException,
catchClause.CatchKeyword.GetLocation());
}
}
}
}
string GetLocalVariableMarkup (ILocalSymbol local)
{
if (local == null)
throw new ArgumentNullException ("local");
var result = new StringBuilder ();
if (local.IsConst)
result.Append (Highlight ("const ", colorStyle.KeywordModifiers));
result.Append (GetTypeReferenceString (local.Type));
if (BreakLineAfterReturnType) {
result.AppendLine ();
} else {
result.Append (" ");
}
result.Append (FilterEntityName (local.Name));
if (local.IsConst) {
if (options.GetOption (CSharpFormattingOptions.SpacingAroundBinaryOperator) == BinaryOperatorSpacingOptions.Single) {
result.Append (" = ");
} else {
result.Append ("=");
}
AppendConstant (result, local.Type, local.ConstantValue);
}
return result.ToString ();
}
private static bool IsEndingWithDispose(SemanticModel semanticModel, List <StatementSyntax> insideUsing, ILocalSymbol disposableLocal)
{
var lastInUsingAsCall = (((insideUsing.LastOrDefault() as ExpressionStatementSyntax)?.Expression as InvocationExpressionSyntax)?.Expression as MemberAccessExpressionSyntax);
if (lastInUsingAsCall == null)
{
return(false);
}
var targetSymbol = semanticModel.GetSymbolInfo(lastInUsingAsCall.Expression);
if (!disposableLocal.Equals(targetSymbol.Symbol))
{
return(false);
}
var dispose = semanticModel.Compilation.GetSpecialType(SpecialType.System_IDisposable).GetMembers("Dispose").Single();
var calledMethod = semanticModel.GetSymbolInfo(lastInUsingAsCall).Symbol;
if (!dispose.Equals(calledMethod))
{
return(false);
}
return(true);
}
private async Task AddDescriptionForLocalAsync(ILocalSymbol symbol)
{
var parts = await GetLocalPartsAsync(symbol).ConfigureAwait(false);
AddToGroup(SymbolDescriptionGroups.MainDescription,
symbol.IsConst
? Description(FeaturesResources.local_constant)
: Description(FeaturesResources.local_variable),
parts);
}
private static void ReduceUsingBlock(SemanticModel semanticModel, List <StatementSyntax> insideUsing, ILocalSymbol symbol)
{
for (int i = insideUsing.Count - 1; i >= 0; i--)
{
var flow = semanticModel.AnalyzeDataFlow(insideUsing[i]);
if (flow.ReadInside.Contains(symbol) || flow.WrittenInside.Contains(symbol))
{
break;
}
insideUsing.RemoveAt(i);
}
}
public sealed override void Initialize(AnalysisContext context)
{
context.RegisterOperationBlockStartAction(
(operationBlockContext) =>
{
if (operationBlockContext.OwningSymbol is IMethodSymbol containingMethod)
{
HashSet <ILocalSymbol> mightBecomeConstLocals = new HashSet <ILocalSymbol>();
HashSet <ILocalSymbol> assignedToLocals = new HashSet <ILocalSymbol>();
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
if (operationContext.Operation is IAssignmentOperation assignment)
{
AssignTo(assignment.Target, assignedToLocals, mightBecomeConstLocals);
}
else if (operationContext.Operation is IIncrementOrDecrementOperation increment)
{
AssignTo(increment.Target, assignedToLocals, mightBecomeConstLocals);
}
else
{
throw TestExceptionUtilities.UnexpectedValue(operationContext.Operation);
}
},
OperationKind.SimpleAssignment,
OperationKind.CompoundAssignment,
OperationKind.Increment);
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
IInvocationOperation invocation = (IInvocationOperation)operationContext.Operation;
foreach (IArgumentOperation argument in invocation.Arguments)
{
if (argument.Parameter.RefKind == RefKind.Out || argument.Parameter.RefKind == RefKind.Ref)
{
AssignTo(argument.Value, assignedToLocals, mightBecomeConstLocals);
}
}
},
OperationKind.Invocation);
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
IVariableDeclarationGroupOperation declaration = (IVariableDeclarationGroupOperation)operationContext.Operation;
foreach (IVariableDeclaratorOperation variable in declaration.Declarations.SelectMany(decl => decl.Declarators))
{
ILocalSymbol local = variable.Symbol;
if (!local.IsConst && !assignedToLocals.Contains(local))
{
var localType = local.Type;
if ((!localType.IsReferenceType || localType.SpecialType == SpecialType.System_String) && localType.SpecialType != SpecialType.None)
{
IVariableInitializerOperation initializer = variable.GetVariableInitializer();
if (initializer != null && initializer.Value.ConstantValue.HasValue)
{
mightBecomeConstLocals.Add(local);
}
}
}
}
},
OperationKind.VariableDeclarationGroup);
operationBlockContext.RegisterOperationBlockEndAction(
(operationBlockEndContext) =>
{
foreach (ILocalSymbol couldBeConstLocal in mightBecomeConstLocals)
{
Report(operationBlockEndContext, couldBeConstLocal, LocalCouldBeConstDescriptor);
}
});
}
});
}
public sealed override void Initialize(AnalysisContext context)
{
context.RegisterCompilationStartAction(
(compilationContext) =>
{
Dictionary <IFieldSymbol, HashSet <INamedTypeSymbol> > fieldsSourceTypes = new Dictionary <IFieldSymbol, HashSet <INamedTypeSymbol> >();
compilationContext.RegisterOperationBlockStartAction(
(operationBlockContext) =>
{
if (operationBlockContext.OwningSymbol is IMethodSymbol containingMethod)
{
Dictionary <ILocalSymbol, HashSet <INamedTypeSymbol> > localsSourceTypes = new Dictionary <ILocalSymbol, HashSet <INamedTypeSymbol> >();
// Track explicit assignments.
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
if (operationContext.Operation is IAssignmentOperation assignment)
{
AssignTo(assignment.Target, localsSourceTypes, fieldsSourceTypes, assignment.Value);
}
else if (operationContext.Operation is IIncrementOrDecrementOperation increment)
{
SyntaxNode syntax = increment.Syntax;
ITypeSymbol type = increment.Type;
Optional <object> constantValue = new Optional <object>(1);
bool isImplicit = increment.IsImplicit;
var value = new LiteralOperation(operationContext.Compilation.GetSemanticModel(syntax.SyntaxTree), syntax, type, constantValue, isImplicit);
AssignTo(increment.Target, localsSourceTypes, fieldsSourceTypes, value);
}
else
{
throw TestExceptionUtilities.UnexpectedValue(operationContext.Operation);
}
},
OperationKind.SimpleAssignment,
OperationKind.CompoundAssignment,
OperationKind.Increment);
// Track arguments that match out or ref parameters.
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
IInvocationOperation invocation = (IInvocationOperation)operationContext.Operation;
foreach (IArgumentOperation argument in invocation.Arguments)
{
if (argument.Parameter.RefKind == RefKind.Out || argument.Parameter.RefKind == RefKind.Ref)
{
AssignTo(argument.Value, localsSourceTypes, fieldsSourceTypes, argument.Parameter.Type);
}
}
},
OperationKind.Invocation);
// Track local variable initializations.
operationBlockContext.RegisterOperationAction(
(operationContext) =>
{
IVariableInitializerOperation initializer = (IVariableInitializerOperation)operationContext.Operation;
// If the parent is a single variable declaration, just process that one variable. If it's a multi variable
// declaration, process all variables being assigned
if (initializer.Parent is IVariableDeclaratorOperation singleVariableDeclaration)
{
ILocalSymbol local = singleVariableDeclaration.Symbol;
AssignTo(local, local.Type, localsSourceTypes, initializer.Value);
}
else if (initializer.Parent is IVariableDeclarationOperation multiVariableDeclaration)
{
foreach (ILocalSymbol local in multiVariableDeclaration.GetDeclaredVariables())
{
AssignTo(local, local.Type, localsSourceTypes, initializer.Value);
}
}
},
OperationKind.VariableInitializer);
// Report locals that could have more specific types.
operationBlockContext.RegisterOperationBlockEndAction(
(operationBlockEndContext) =>
{
foreach (ILocalSymbol local in localsSourceTypes.Keys)
{
if (HasMoreSpecificSourceType(local, local.Type, localsSourceTypes, out var mostSpecificSourceType))
{
Report(operationBlockEndContext, local, mostSpecificSourceType, LocalCouldHaveMoreSpecificTypeDescriptor);
}
}
});
}
});
// Track field initializations.
compilationContext.RegisterOperationAction(
(operationContext) =>
{
IFieldInitializerOperation initializer = (IFieldInitializerOperation)operationContext.Operation;
foreach (IFieldSymbol initializedField in initializer.InitializedFields)
{
AssignTo(initializedField, initializedField.Type, fieldsSourceTypes, initializer.Value);
}
},
OperationKind.FieldInitializer);
// Report fields that could have more specific types.
compilationContext.RegisterCompilationEndAction(
(compilationEndContext) =>
{
foreach (IFieldSymbol field in fieldsSourceTypes.Keys)
{
if (HasMoreSpecificSourceType(field, field.Type, fieldsSourceTypes, out var mostSpecificSourceType))
{
Report(compilationEndContext, field, mostSpecificSourceType, FieldCouldHaveMoreSpecificTypeDescriptor);
}
}
});
});
}
/// <summary>
/// Retrieve a local slot by its symbol.
/// </summary>
internal LocalDefinition GetLocal(ILocalSymbol symbol)
{
return(LocalMap[symbol]);
}
public VariableDeclaration(ILocalSymbol variable, IExpression initialValue, SyntaxNode syntax)
{
Variable = variable;
InitialValue = initialValue;
Syntax = syntax;
}
public virtual void VisitLocal(ILocalSymbol symbol)
{
DefaultVisit(symbol);
}
private static string GetClassificationForLocal(ILocalSymbol localSymbol)
{
return(localSymbol.IsConst
? ClassificationTypeNames.ConstantName
: ClassificationTypeNames.LocalName);
}
public VariableDeclaration(ILocalSymbol variable, IExpression initialValue, SyntaxNode syntax)
{
Variable = variable;
InitialValue = initialValue;
Syntax = syntax;
}
private static bool TryAnalyze(
SemanticModel semanticModel,
ILocalSymbol local,
TypeSyntax typeNode,
SyntaxToken identifier,
Conversion conversion,
SyntaxNode searchScope,
[NotNullWhen(true)] out INamedTypeSymbol?tupleType,
out ImmutableArray <MemberAccessExpressionSyntax> memberAccessExpressions,
CancellationToken cancellationToken)
{
tupleType = null;
memberAccessExpressions = default;
if (identifier.IsMissing)
{
return(false);
}
if (!IsViableTupleTypeSyntax(typeNode))
{
return(false);
}
if (conversion.Exists &&
!conversion.IsIdentity &&
!conversion.IsTupleConversion &&
!conversion.IsTupleLiteralConversion)
{
// If there is any other conversion, we bail out because the source type might not be a tuple
// or it is a tuple but only thanks to target type inference, which won't occur in a deconstruction.
// Interesting case that illustrates this is initialization with a default literal:
// (int a, int b) t = default;
// This is classified as conversion.IsNullLiteral.
return(false);
}
var type = semanticModel.GetTypeInfo(typeNode, cancellationToken).Type;
if (type == null || !type.IsTupleType)
{
return(false);
}
tupleType = (INamedTypeSymbol)type;
if (tupleType.TupleElements.Length < 2)
{
return(false);
}
// All tuple elements must have been explicitly provided by the user.
foreach (var element in tupleType.TupleElements)
{
if (element.IsImplicitlyDeclared)
{
return(false);
}
}
using var _ = ArrayBuilder <MemberAccessExpressionSyntax> .GetInstance(out var references);
// If the user actually uses the tuple local for anything other than accessing
// fields off of it, then we can't deconstruct this tuple into locals.
if (!OnlyUsedToAccessTupleFields(
semanticModel, searchScope, local, references, cancellationToken))
{
return(false);
}
// Can only deconstruct the tuple if the names we introduce won't collide
// with anything else in scope (either outside, or inside the method).
if (AnyTupleFieldNamesCollideWithExistingNames(
semanticModel, tupleType, searchScope, cancellationToken))
{
return(false);
}
memberAccessExpressions = references.ToImmutable();
return(true);
}
public override void VisitLocal(ILocalSymbol symbol)
{
if (format.LocalOptions.IncludesOption(SymbolDisplayLocalOptions.IncludeType))
{
symbol.Type.Accept(this);
AddSpace();
}
builder.Add(CreatePart(SymbolDisplayPartKind.LocalName, symbol, symbol.Name));
if (symbol.IsConst &&
symbol.HasConstantValue &&
format.LocalOptions.IncludesOption(SymbolDisplayLocalOptions.IncludeConstantValue) &&
CanAddConstant(symbol.Type, symbol.ConstantValue))
{
AddSpace();
AddPunctuation(SyntaxKind.EqualsToken);
AddSpace();
AddConstantValue(symbol.Type, symbol.ConstantValue);
}
}
protected override bool CanMoveToBlock(ILocalSymbol localSymbol, SyntaxNode currentBlock, SyntaxNode destinationBlock) => localSymbol.CanSafelyMoveLocalToBlock(currentBlock, destinationBlock);
private void Report(OperationBlockAnalysisContext context, ILocalSymbol local, DiagnosticDescriptor descriptor)
{
context.ReportDiagnostic(Diagnostic.Create(descriptor, local.Locations.FirstOrDefault()));
}
public virtual void VisitLocal(ILocalSymbol symbol)
{
DefaultVisit(symbol);
}
private bool LocalsAreEquivalent(ILocalSymbol x, ILocalSymbol y)
{
return HaveSameLocation(x, y);
}
public override void VisitLocal(ILocalSymbol symbol)
{
symbol.Type.Accept(this);
}
private static IEnumerable<int> GetAssignedIndexes(IEnumerable<StatementSyntax> statements, ILocalSymbol symbol, SemanticModel semanticModel)
{
foreach (var statement in statements)
{
var assignment = statement as AssignmentStatementSyntax;
if (assignment == null)
{
yield break;
}
var invocation = assignment.Left as InvocationExpressionSyntax;
if (invocation?.ArgumentList == null ||
invocation.ArgumentList.Arguments.Count != 1)
{
yield break;
}
var assignedSymbol = semanticModel.GetSymbolInfo(invocation.Expression).Symbol;
if (!symbol.Equals(assignedSymbol))
{
yield break;
}
var argument = invocation.ArgumentList.Arguments.First();
var index = GetConstantArgumentValue(argument, semanticModel);
if (!index.HasValue)
{
yield break;
}
yield return index.Value;
}
}
private LoopDeclarationVerifier(ForStatementSyntax forStatement, SemanticModel semanticModel, ILocalSymbol loopIndex)
{
_forStatement = forStatement;
_semanticModel = semanticModel;
_loopIndex = loopIndex;
}
private static bool IsReturned(MethodDeclarationSyntax method, StatementSyntax statement, SemanticModel semanticModel, ILocalSymbol identitySymbol)
{
var anonymousFunction = statement.FirstAncestorOfKind(SyntaxKind.ParenthesizedLambdaExpression,
SyntaxKind.SimpleLambdaExpression, SyntaxKind.AnonymousMethodExpression) as AnonymousFunctionExpressionSyntax;
IMethodSymbol methodSymbol;
BlockSyntax body;
if (anonymousFunction != null)
{
methodSymbol = semanticModel.GetSymbolInfo(anonymousFunction).Symbol as IMethodSymbol;
body = anonymousFunction.Body as BlockSyntax;
}
else
{
methodSymbol = semanticModel.GetDeclaredSymbol(method);
body = method.Body;
}
if (body == null) return true;
var returnExpressions = body.DescendantNodes().OfType<ReturnStatementSyntax>().Select(r => r.Expression);
var returnTypeSymbol = methodSymbol?.ReturnType;
if (returnTypeSymbol == null) return false;
if (returnTypeSymbol.SpecialType == SpecialType.System_Void) return false;
var isReturning = returnExpressions.Any(returnExpression =>
{
var returnSymbol = semanticModel.GetSymbolInfo(returnExpression).Symbol;
if (returnSymbol == null) return false;
return returnSymbol.Equals(identitySymbol);
});
return isReturning;
}
public override bool VisitLocal(ILocalSymbol symbol)
{
return(Visit(symbol.Type));
}
private static bool IsCorrectDispose(ExpressionStatementSyntax expressionStatement, SemanticModel semanticModel, ILocalSymbol identitySymbol)
{
if (expressionStatement == null) return false;
var invocation = expressionStatement.Expression as InvocationExpressionSyntax;
if (invocation?.ArgumentList.Arguments.Any() ?? true) return false;
var memberAccess = invocation.Expression as MemberAccessExpressionSyntax;
if (memberAccess == null) return false;
ISymbol memberSymbol;
if (memberAccess.Expression.IsKind(SyntaxKind.IdentifierName))
{
memberSymbol = semanticModel.GetSymbolInfo(memberAccess.Expression).Symbol;
}
else if (memberAccess.Expression.IsKind(SyntaxKind.ParenthesizedExpression))
{
var parenthesizedExpression = (ParenthesizedExpressionSyntax)memberAccess.Expression;
var cast = parenthesizedExpression.Expression as CastExpressionSyntax;
if (cast == null) return false;
var catTypeSymbol = semanticModel.GetTypeInfo(cast.Type).Type;
if (catTypeSymbol.SpecialType != SpecialType.System_IDisposable) return false;
memberSymbol = semanticModel.GetSymbolInfo(cast.Expression).Symbol;
}
else return false;
if (memberSymbol == null || !memberSymbol.Equals(identitySymbol)) return false;
var memberAccessed = memberAccess.Name as IdentifierNameSyntax;
if (memberAccessed == null) return false;
if (memberAccessed.Identifier.Text != "Dispose" || memberAccessed.Arity != 0) return false;
var methodSymbol = semanticModel.GetSymbolInfo(memberAccessed).Symbol as IMethodSymbol;
if (methodSymbol == null) return false;
if (methodSymbol.ToString() == "System.IDisposable.Dispose()") return true;
var disposeMethod = (IMethodSymbol)semanticModel.Compilation.GetSpecialType(SpecialType.System_IDisposable).GetMembers("Dispose").Single();
var isDispose = methodSymbol.Equals(methodSymbol.ContainingType.FindImplementationForInterfaceMember(disposeMethod));
return isDispose;
}
private static void GetInterfaceInfo(
SemanticModel model,
ILocalSymbol foreachVariable,
IOperation foreachCollection,
out ITypeSymbol explicitCastInterface,
out string collectionNameSuggestion,
out string countName
)
{
explicitCastInterface = null;
collectionNameSuggestion = null;
countName = null;
// go through list of types and interfaces to find out right set;
var foreachType = foreachVariable.Type;
if (IsNullOrErrorType(foreachType))
{
return;
}
var collectionType = foreachCollection.Type;
if (IsNullOrErrorType(collectionType))
{
return;
}
// go through explicit types first.
// check array case
if (collectionType is IArrayTypeSymbol array)
{
if (array.Rank != 1)
{
// array type supports IList and other interfaces, but implementation
// only supports Rank == 1 case. other case, it will throw on runtime
// even if there is no error on compile time.
// we explicitly mark that we only support Rank == 1 case
return;
}
if (!IsExchangable(array.ElementType, foreachType, model.Compilation))
{
return;
}
collectionNameSuggestion = "array";
explicitCastInterface = null;
countName = Length;
return;
}
// check string case
if (collectionType.SpecialType == SpecialType.System_String)
{
var charType = model.Compilation.GetSpecialType(SpecialType.System_Char);
if (!IsExchangable(charType, foreachType, model.Compilation))
{
return;
}
collectionNameSuggestion = "str";
explicitCastInterface = null;
countName = Length;
return;
}
// check ImmutableArray case
if (
collectionType.OriginalDefinition.Equals(
model.Compilation.GetTypeByMetadataName(typeof(ImmutableArray <>).FullName)
)
)
{
var indexer = GetInterfaceMember(collectionType, get_Item);
if (indexer != null)
{
if (!IsExchangable(indexer.ReturnType, foreachType, model.Compilation))
{
return;
}
collectionNameSuggestion = "array";
explicitCastInterface = null;
countName = Length;
return;
}
}
// go through all known interfaces we support next.
var knownCollectionInterfaces = s_KnownInterfaceNames
.Select(s => model.Compilation.GetTypeByMetadataName(s))
.Where(t => !IsNullOrErrorType(t));
// for all interfaces, we suggest collection name as "list"
collectionNameSuggestion = "list";
// check type itself is interface case
if (
collectionType.TypeKind == TypeKind.Interface &&
knownCollectionInterfaces.Contains(collectionType.OriginalDefinition)
)
{
var indexer = GetInterfaceMember(collectionType, get_Item);
if (
indexer != null &&
IsExchangable(indexer.ReturnType, foreachType, model.Compilation)
)
{
explicitCastInterface = null;
countName = Count;
return;
}
}
// check regular cases (implicitly implemented)
ITypeSymbol explicitInterface = null;
foreach (var current in collectionType.AllInterfaces)
{
if (!knownCollectionInterfaces.Contains(current.OriginalDefinition))
{
continue;
}
// see how the type implements the interface
var countSymbol = GetInterfaceMember(current, get_Count);
var indexerSymbol = GetInterfaceMember(current, get_Item);
if (countSymbol == null || indexerSymbol == null)
{
continue;
}
if (
!(
collectionType.FindImplementationForInterfaceMember(countSymbol)
is IMethodSymbol countImpl
) ||
!(
collectionType.FindImplementationForInterfaceMember(indexerSymbol)
is IMethodSymbol indexerImpl
)
)
{
continue;
}
if (!IsExchangable(indexerImpl.ReturnType, foreachType, model.Compilation))
{
continue;
}
// implicitly implemented!
if (
countImpl.ExplicitInterfaceImplementations.IsEmpty &&
indexerImpl.ExplicitInterfaceImplementations.IsEmpty
)
{
explicitCastInterface = null;
countName = Count;
return;
}
if (explicitInterface == null)
{
explicitInterface = current;
}
}
// okay, we don't have implicitly implemented one, but we do have explicitly implemented one
if (explicitInterface != null)
{
explicitCastInterface = explicitInterface;
countName = Count;
}
}
private static bool IsReturned(MethodDeclarationSyntax method, SemanticModel semanticModel, ILocalSymbol identitySymbol)
{
var returnTypeSymbol = semanticModel.GetTypeInfo(method.ReturnType).Type;
if (returnTypeSymbol == null) return false;
if (returnTypeSymbol.SpecialType == SpecialType.System_Void || !returnTypeSymbol.Equals(identitySymbol.Type)) return false;
var returns = method.Body.DescendantNodes().OfType<ReturnStatementSyntax>();
var isReturning = returns.Any(r =>
{
var returnSymbol = semanticModel.GetSymbolInfo(r.Expression).Symbol;
if (returnSymbol == null) return false;
return returnSymbol.Equals(identitySymbol);
});
return isReturning;
}
protected abstract bool IsSupported(
ILocalSymbol foreachVariable,
IForEachLoopOperation forEachOperation,
TForEachStatement foreachStatement
);
private InitializerRewriter(ExpressionSyntax initializer, ILocalSymbol localSymbol, SemanticModel semanticModel)
{
_semanticModel = semanticModel;
_localSymbol = localSymbol;
_initializer = initializer;
}
private async Task <ImmutableArray <SymbolDisplayPart> > GetLocalPartsAsync(ILocalSymbol symbol)
{
if (symbol.IsConst)
{
var initializerParts = await GetInitializerSourcePartsAsync(symbol).ConfigureAwait(false);
if (initializerParts != null)
{
var parts = ArrayBuilder <SymbolDisplayPart> .GetInstance();
parts.AddRange(ToMinimalDisplayParts(symbol, MinimallyQualifiedFormat));
parts.AddRange(Space());
parts.AddRange(Punctuation("="));
parts.AddRange(Space());
parts.AddRange(initializerParts);
return(parts.ToImmutableAndFree());
}
}
return(ToMinimalDisplayParts(symbol, MinimallyQualifiedFormatWithConstants));
}
public override object VisitLocal(ILocalSymbol localSymbol)
{
WriteType(SymbolKeyType.BodyLevel);
BodyLevelSymbolKey.Create(localSymbol, this);
return(null);
}
private void Report(OperationBlockAnalysisContext context, ILocalSymbol local, DiagnosticDescriptor descriptor)
{
context.ReportDiagnostic(Diagnostic.Create(descriptor, local.Locations.FirstOrDefault()));
}
private async Task<ImmutableArray<SymbolDisplayPart>> GetLocalPartsAsync(ILocalSymbol symbol)
{
if (symbol.IsConst)
{
var initializerParts = await GetInitializerSourcePartsAsync(symbol).ConfigureAwait(false);
if (initializerParts != null)
{
var parts = ArrayBuilder<SymbolDisplayPart>.GetInstance();
parts.AddRange(ToMinimalDisplayParts(symbol, MinimallyQualifiedFormat));
parts.AddRange(Space());
parts.AddRange(Punctuation("="));
parts.AddRange(Space());
parts.AddRange(initializerParts);
return parts.ToImmutableAndFree();
}
}
return ToMinimalDisplayParts(symbol, MinimallyQualifiedFormatWithConstants);
}
public RecursiveIsNewlyCreatedObjectState Add(ILocalSymbol variable) => new RecursiveIsNewlyCreatedObjectState(VariablesUnderTest.Add(variable));
