private void HandleGenericNameSyntax(SyntaxNodeAnalysisContext context)
{
GenericNameSyntax genericNameSyntax = context.Node as GenericNameSyntax;
if (genericNameSyntax == null)
{
return;
}
if (genericNameSyntax.Identifier.IsMissing || genericNameSyntax.Identifier.Text != "Nullable")
{
return;
}
// This covers the specific forms in an XML comment which cannot be simplified
if (genericNameSyntax.Parent is NameMemberCrefSyntax)
{
// cref="Nullable{T}"
return;
}
else if (genericNameSyntax.Parent is QualifiedCrefSyntax)
{
// cref="Nullable{T}.Value"
return;
}
else if (genericNameSyntax.Parent is QualifiedNameSyntax && genericNameSyntax.Parent.Parent is QualifiedCrefSyntax)
{
// cref="System.Nullable{T}.Value"
return;
}
// The shorthand syntax is not available in using directives (covers standard, alias, and static)
if (genericNameSyntax.FirstAncestorOrSelf <UsingDirectiveSyntax>() != null)
{
return;
}
// This covers special cases of static and instance member access through the type name. It also covers most
// special cases for the `nameof` expression.
if (genericNameSyntax.Parent is MemberAccessExpressionSyntax)
{
return;
}
// This covers the special case of `nameof(Nullable<int>)`
if (genericNameSyntax.Parent is ArgumentSyntax)
{
return;
}
SemanticModel semanticModel = context.SemanticModel;
INamedTypeSymbol symbol = semanticModel.GetSymbolInfo(genericNameSyntax, context.CancellationToken).Symbol as INamedTypeSymbol;
if (symbol?.OriginalDefinition?.SpecialType != SpecialType.System_Nullable_T)
{
return;
}
if (symbol.IsUnboundGenericType)
{
// There is never a shorthand syntax for the open generic Nullable<>
return;
}
SyntaxNode locationNode = genericNameSyntax;
if (genericNameSyntax.Parent is QualifiedNameSyntax)
{
locationNode = genericNameSyntax.Parent;
}
// Use shorthand for nullable types
context.ReportDiagnostic(Diagnostic.Create(Descriptor, locationNode.GetLocation()));
}
