public override SyntaxNode?VisitFieldDeclaration(FieldDeclarationSyntax node)
{
if (_uninitializedVariables.Contains(node))
{
return(node.WithDeclaration(
node.Declaration.WithType(NullUtilities.ToNullable(node.Declaration.Type))));
}
return(node);
}
public override SyntaxNode?VisitPropertyDeclaration(PropertyDeclarationSyntax node)
{
if (HasCanBeNullAttribute(node) ||
IsInClassOrStruct(node) &&
(GetterReturnsNull(node) ||
IsUninitialized(node)))
{
return(node.WithType(NullUtilities.ToNullable(node.Type)));
}
return(node);
}
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);
}
public override SyntaxNode?VisitMethodDeclaration(MethodDeclarationSyntax node)
{
if (_nullableInterfaces.TryGetValue(node, out var parameterNames))
{
if (parameterNames.Contains("#return"))
{
node = node.WithReturnType(NullUtilities.ToNullable(node.ReturnType));
}
var newParameterList = parameterNames.Aggregate(node.ParameterList, ToNullableParameter);
return(node.WithParameterList(newParameterList));
}
return(base.VisitMethodDeclaration(node));
}
public override SyntaxNode?VisitLocalDeclarationStatement(LocalDeclarationStatementSyntax node)
{
if (node.Declaration.Type.IsVar)
{
return(node);
}
if (node.Declaration.Type is NullableTypeSyntax)
{
return(node);
}
var type = node.Declaration.Type;
var isNullable = node.Declaration.Variables
.Where(variable => variable.Initializer != null)
.Any(variable => NullUtilities.CanBeNull(variable.Initializer !.Value, _semanticModel));
return(isNullable
? node.WithDeclaration(node.Declaration.WithType(NullUtilities.ToNullable(type)))
: node);
}
public override SyntaxNode?VisitMethodDeclaration(MethodDeclarationSyntax node)
{
var newParameters = node.ParameterList.Parameters;
foreach (var parameter in node.ParameterList.Parameters)
{
if (IsNullableParameter(parameter))
{
if (parameter.Type == null)
{
continue;
}
var toReplace = newParameters.SingleOrDefault(param => param.Identifier.ToString() == parameter.Identifier.ToString());
if (toReplace.Type != null)
{
newParameters = newParameters.Replace(toReplace, toReplace.WithType(NullUtilities.ToNullable(toReplace.Type)));
}
}
}
return(node.WithParameterList(node.ParameterList.WithParameters(newParameters)));
}
