private static void HandleDisposeMethod(SyntaxNodeAnalysisContext context)
{
if (context.IsExcludedFromAnalysis())
{
return;
}
if (context.ContainingSymbol is IMethodSymbol method &&
method.IsOverride &&
method.Name == "Dispose")
{
var overridden = method.OverriddenMethod;
if (overridden == null)
{
return;
}
using (var invocations = InvocationWalker.Create(context.Node))
{
foreach (var invocation in invocations.Item)
{
if (
SymbolComparer.Equals(
context.SemanticModel.GetSymbolSafe(invocation, context.CancellationToken), overridden))
{
return;
}
}
}
if (overridden.DeclaringSyntaxReferences.Length == 0)
{
context.ReportDiagnostic(Diagnostic.Create(Descriptor, context.Node.GetLocation()));
return;
}
using (
var disposeWalker = Disposable.DisposeWalker.Create(overridden, context.SemanticModel, context.CancellationToken))
{
foreach (var disposeCall in disposeWalker.Item)
{
if (Disposable.TryGetDisposedRootMember(disposeCall, context.SemanticModel, context.CancellationToken, out ExpressionSyntax disposed))
{
var member = context.SemanticModel.GetSymbolSafe(disposed, context.CancellationToken);
if (
!Disposable.IsMemberDisposed(member, method, context.SemanticModel, context.CancellationToken))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptor, context.Node.GetLocation()));
return;
}
}
}
}
}
}
private static void HandleProperty(SyntaxNodeAnalysisContext context)
{
if (context.IsExcludedFromAnalysis())
{
return;
}
var property = (IPropertySymbol)context.ContainingSymbol;
if (property.IsStatic ||
property.IsIndexer)
{
return;
}
var propertyDeclaration = (PropertyDeclarationSyntax)context.Node;
if (propertyDeclaration.ExpressionBody != null)
{
return;
}
if (propertyDeclaration.TryGetSetAccessorDeclaration(out AccessorDeclarationSyntax setter) &&
setter.Body != null)
{
// Handle the backing field
return;
}
if (Disposable.IsAssignedWithCreatedAndNotCachedOrInjected(property, context.SemanticModel, context.CancellationToken))
{
if (Disposable.IsMemberDisposed(property, context.Node.FirstAncestorOrSelf <TypeDeclarationSyntax>(), context.SemanticModel, context.CancellationToken)
.IsEither(Result.No, Result.Unknown))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptor, context.Node.GetLocation()));
}
}
}
private static void HandleField(SyntaxNodeAnalysisContext context)
{
if (context.IsExcludedFromAnalysis())
{
return;
}
var field = (IFieldSymbol)context.ContainingSymbol;
if (field.IsStatic)
{
return;
}
if (Disposable.IsAssignedWithCreatedAndNotCachedOrInjected(field, context.SemanticModel, context.CancellationToken))
{
if (Disposable.IsMemberDisposed(field, context.Node.FirstAncestorOrSelf <TypeDeclarationSyntax>(), context.SemanticModel, context.CancellationToken)
.IsEither(Result.No, Result.Unknown))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptor, context.Node.GetLocation()));
}
}
}
private static bool MustBeHandled(
ExpressionSyntax node,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
if (node.Parent is AnonymousFunctionExpressionSyntax ||
node.Parent is UsingStatementSyntax ||
node.Parent is EqualsValueClauseSyntax ||
node.Parent is ReturnStatementSyntax ||
node.Parent is ArrowExpressionClauseSyntax)
{
return(false);
}
if (Disposable.IsCreation(node, semanticModel, cancellationToken)
.IsEither(Result.No, Result.Unknown))
{
return(false);
}
if (node.Parent is StatementSyntax)
{
return(true);
}
if (node.Parent is ArgumentSyntax argument)
{
if (argument.Parent.Parent is InvocationExpressionSyntax invocation)
{
using (var returnWalker = ReturnValueWalker.Create(invocation, Search.Recursive, semanticModel, cancellationToken))
{
foreach (var returnValue in returnWalker.Item)
{
if (MustBeHandled(returnValue, semanticModel, cancellationToken))
{
return(true);
}
}
}
return(false);
}
if (argument.Parent.Parent is ObjectCreationExpressionSyntax)
{
if (TryGetAssignedFieldOrProperty(argument, semanticModel, cancellationToken, out ISymbol member, out IMethodSymbol ctor) &&
member != null)
{
var initializer = argument.FirstAncestorOrSelf <ConstructorInitializerSyntax>();
if (initializer != null)
{
if (semanticModel.GetDeclaredSymbolSafe(initializer.Parent, cancellationToken) is IMethodSymbol chainedCtor &&
chainedCtor.ContainingType != member.ContainingType)
{
if (Disposable.TryGetDisposeMethod(chainedCtor.ContainingType, Search.TopLevel, out IMethodSymbol disposeMethod))
{
return(!Disposable.IsMemberDisposed(member, disposeMethod, semanticModel, cancellationToken));
}
}
}
if (Disposable.IsMemberDisposed(member, ctor.ContainingType, semanticModel, cancellationToken)
.IsEither(Result.Yes, Result.Maybe))
{
return(false);
}
return(true);
}
return(ctor?.ContainingType != KnownSymbol.StreamReader &&
ctor?.ContainingType != KnownSymbol.CompositeDisposable);
}
}
return(false);
}
