/// <summary>
/// Check if any path returns a created IDisposable
/// </summary>
internal static Result IsAssignedWithCreated(ExpressionSyntax disposable, SemanticModel semanticModel, CancellationToken cancellationToken, out ISymbol assignedSymbol)
{
if (!IsPotentiallyAssignableTo(disposable, semanticModel, cancellationToken))
{
assignedSymbol = null;
return(Result.No);
}
if (semanticModel.GetSymbolSafe(disposable, cancellationToken) is IPropertySymbol property &&
property.TryGetSetter(cancellationToken, out var setter))
{
using (var pooledSet = PooledHashSet <ISymbol> .Borrow())
{
using (var pooledAssigned = AssignmentWalker.Borrow(setter, Search.Recursive, semanticModel, cancellationToken))
{
foreach (var assigned in pooledAssigned.Assignments)
{
var symbol = semanticModel.GetSymbolSafe(assigned.Left, cancellationToken);
if (IsPotentiallyAssignableTo(assigned.Left, semanticModel, cancellationToken) &&
(symbol is IFieldSymbol ||
symbol is IPropertySymbol))
{
pooledSet.Add(symbol).IgnoreReturnValue();
}
}
}
assignedSymbol = null;
var result = Result.No;
foreach (var symbol in pooledSet)
{
switch (IsAssignedWithCreated(symbol, disposable, semanticModel, cancellationToken))
{
case Result.Unknown:
if (result == Result.No)
{
assignedSymbol = symbol;
result = Result.Unknown;
}
break;
case Result.Yes:
assignedSymbol = symbol;
return(Result.Yes);
case Result.AssumeYes:
assignedSymbol = symbol;
result = Result.AssumeYes;
break;
case Result.No:
case Result.AssumeNo:
break;
default:
throw new ArgumentOutOfRangeException();
}
}
return(result);
}
}
using (var assignedValues = AssignedValueWalker.Borrow(disposable, semanticModel, cancellationToken))
{
assignedSymbol = assignedValues.CurrentSymbol;
if (assignedValues.Count == 1 &&
disposable.Parent is AssignmentExpressionSyntax assignment &&
assignment.Parent is ParenthesizedExpressionSyntax parenthesizedExpression &&
parenthesizedExpression.Parent is BinaryExpressionSyntax binary &&
binary.IsKind(SyntaxKind.CoalesceExpression))
{
return(Result.No);
}
using (var recursive = RecursiveValues.Create(assignedValues, semanticModel, cancellationToken))
{
return(IsAnyCreation(recursive, semanticModel, cancellationToken));
}
}
}
internal static Result IsArgumentDisposedByReturnValue(ArgumentSyntax argument, SemanticModel semanticModel, CancellationToken cancellationToken, PooledHashSet <SyntaxNode> visited = null)
{
if (argument?.Parent is ArgumentListSyntax argumentList)
{
if (argumentList.Parent is InvocationExpressionSyntax invocation &&
semanticModel.GetSymbolSafe(invocation, cancellationToken) is IMethodSymbol method)
{
if (method.ContainingType.DeclaringSyntaxReferences.Length == 0)
{
if (method == KnownSymbol.CompositeDisposable.Add)
{
return(Result.Yes);
}
return(method.ReturnsVoid ||
!IsAssignableTo(method.ReturnType)
? Result.No
: Result.AssumeYes);
}
if (invocation.TryGetMatchingParameter(argument, semanticModel, cancellationToken, out var parameter))
{
return(CheckReturnValues(parameter, invocation, semanticModel, cancellationToken, visited));
}
return(Result.Unknown);
}
if (argumentList.Parent is ObjectCreationExpressionSyntax ||
argumentList.Parent is ConstructorInitializerSyntax)
{
if (TryGetAssignedFieldOrProperty(argument, semanticModel, cancellationToken, out var member, out var 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 (TryGetDelRefMethod(chainedCtor.ContainingType, Search.TopLevel, out var disposeMethod))
{
return(IsMemberDisposed(member, disposeMethod, semanticModel, cancellationToken)
? Result.Yes
: Result.No);
}
}
}
return(IsMemberDisposed(member, ctor.ContainingType, semanticModel, cancellationToken));
}
if (ctor == null)
{
return(Result.AssumeYes);
}
if (ctor.ContainingType.DeclaringSyntaxReferences.Length == 0)
{
return(IsAssignableTo(ctor.ContainingType) ? Result.AssumeYes : Result.No);
}
return(Result.No);
}
}
return(Result.Unknown);
}
internal static Result IsArgumentDisposedByInvocationReturnValue(MemberAccessExpressionSyntax memberAccess, SemanticModel semanticModel, CancellationToken cancellationToken, PooledHashSet <SyntaxNode> visited = null)
{
var symbol = semanticModel.GetSymbolSafe(memberAccess, cancellationToken);
if (symbol is IMethodSymbol method)
{
if (method.ReturnType.Name == "ConfiguredTaskAwaitable")
{
return(Result.Yes);
}
if (method.ContainingType.DeclaringSyntaxReferences.Length == 0)
{
return(method.ReturnsVoid ||
!IsAssignableTo(method.ReturnType)
? Result.No
: Result.AssumeYes);
}
if (method.IsExtensionMethod &&
method.ReducedFrom is IMethodSymbol reducedFrom)
{
var parameter = reducedFrom.Parameters[0];
return(CheckReturnValues(parameter, memberAccess, semanticModel, cancellationToken, visited));
}
}
if (symbol.IsEither <IFieldSymbol, IPropertySymbol>())
{
return(Result.No);
}
return(Result.Unknown);
}
private static Result CheckReturnValues(IParameterSymbol parameter, SyntaxNode memberAccess, SemanticModel semanticModel, CancellationToken cancellationToken, PooledHashSet <SyntaxNode> visited)
{
Result CheckReturnValue(ExpressionSyntax returnValue)
{
if (returnValue is ObjectCreationExpressionSyntax nestedObjectCreation)
{
if (nestedObjectCreation.TryGetMatchingArgument(parameter, out var nestedArgument))
{
return(IsArgumentDisposedByReturnValue(nestedArgument, semanticModel, cancellationToken, visited));
}
return(Result.No);
}
if (returnValue is InvocationExpressionSyntax nestedInvocation)
{
if (nestedInvocation.TryGetMatchingArgument(parameter, out var nestedArgument))
{
return(IsArgumentDisposedByReturnValue(nestedArgument, semanticModel, cancellationToken, visited));
}
return(Result.No);
}
if (returnValue is MemberAccessExpressionSyntax nestedMemberAccess)
{
return(IsArgumentDisposedByInvocationReturnValue(nestedMemberAccess, semanticModel, cancellationToken, visited));
}
return(Result.Unknown);
}
var result = Result.No;
using (var returnWalker = ReturnValueWalker.Borrow(memberAccess, Search.Recursive, semanticModel, cancellationToken))
{
using (visited = PooledHashSet <SyntaxNode> .BorrowOrIncrementUsage(visited))
{
if (!visited.Add(memberAccess))
{
return(Result.Unknown);
}
foreach (var returnValue in returnWalker)
{
switch (CheckReturnValue(returnValue))
{
case Result.Unknown:
return(Result.Unknown);
case Result.Yes:
if (result == Result.No)
{
result = Result.Yes;
}
break;
case Result.AssumeYes:
result = Result.AssumeYes;
break;
case Result.No:
return(Result.No);
case Result.AssumeNo:
return(Result.AssumeNo);
default:
throw new ArgumentOutOfRangeException();
}
}
}
}
return(result);
}
