public override SyntaxNode?VisitInvocationExpression(InvocationExpressionSyntax node)
{
var nullableArguments = node.ArgumentList.Arguments
.Select((arg, index) => (Argument: arg, Index: index))
.Where(indexedArg => NullUtilities.CanBeNull(indexedArg.Argument.Expression, _semanticModel))
.ToList();
if (nullableArguments.Count == 0)
{
return(node);
}
var methodDeclaration = _semanticModel.GetSymbolInfo(node);
var methodSyntax = (MethodDeclarationSyntax?)methodDeclaration.Symbol?.DeclaringSyntaxReferences
.FirstOrDefault()?
.GetSyntaxAsync()?.GetAwaiter().GetResult();
if (methodSyntax == null)
{
return(node);
}
foreach (var indexedArg in nullableArguments)
{
var nullableParameter = methodSyntax.ParameterList.Parameters[indexedArg.Index];
_parameterCallback(nullableParameter);
}
return(node);
}
private bool IsInitializedToNull(VariableDeclaratorSyntax variableDeclarator)
{
if (variableDeclarator.Initializer != null)
{
return(NullUtilities.CanBeNull(variableDeclarator.Initializer.Value, _semanticModel));
}
return(false);
}
public override SyntaxNode?VisitCastExpression(CastExpressionSyntax node)
{
var type = node.Type;
if (type is NullableTypeSyntax)
{
return(node);
}
return(NullUtilities.CanBeNull(node.Expression, _semanticModel)
? node.WithType(NullUtilities.ToNullable(type))
: node);
}
private bool GetterReturnsNull(PropertyDeclarationSyntax node)
{
var propertySymbol = _semanticModel.GetDeclaredSymbol(node);
if (propertySymbol.GetMethod == null)
{
return(false);
}
var getter = propertySymbol.GetMethod;
var getterSyntax = getter.DeclaringSyntaxReferences.FirstOrDefault()?.GetSyntax() as AccessorDeclarationSyntax;
if (getterSyntax?.Body != null)
{
return(NullUtilities.ReturnsNull(getterSyntax.Body.Statements, _semanticModel));
}
if (getterSyntax?.ExpressionBody != null)
{
return(NullUtilities.CanBeNull(getterSyntax.ExpressionBody.Expression, _semanticModel));
}
return(false);
}
private bool IsNotNullInitialized(PropertyDeclarationSyntax node)
{
return(node.Initializer != null &&
!NullUtilities.CanBeNull(node.Initializer.Value, _semanticModel));
}
