private static bool IsDisposedBefore(ISymbol symbol, ExpressionSyntax assignment, SemanticModel semanticModel, CancellationToken cancellationToken)
{
using (var pooled = InvocationWalker.Create(assignment.FirstAncestorOrSelf <MemberDeclarationSyntax>()))
{
foreach (var invocation in pooled.Item.Invocations)
{
if (invocation.IsBeforeInScope(assignment) != Result.Yes)
{
continue;
}
var invokedSymbol = semanticModel.GetSymbolSafe(invocation, cancellationToken);
if (invokedSymbol?.Name != "Dispose")
{
continue;
}
var statement = invocation.FirstAncestorOrSelf <StatementSyntax>();
if (statement != null)
{
using (var pooledNames = IdentifierNameWalker.Create(statement))
{
foreach (var identifierName in pooledNames.Item.IdentifierNames)
{
var otherSymbol = semanticModel.GetSymbolSafe(identifierName, cancellationToken);
if (symbol.Equals(otherSymbol))
{
return(true);
}
}
}
}
}
}
return(false);
}
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);
}