private void InferBaseType(
TService service,
SemanticDocument document,
CancellationToken cancellationToken)
{
// See if we can find a possible base type for the type being generated.
// NOTE(cyrusn): I currently limit this to when we have an object creation node.
// That's because that's when we would have an expression that could be converted to
// something else. i.e. if the user writes "IList<int> list = new Goo()" then we can
// infer a base interface for 'Goo'. However, if they write "IList<int> list = Goo"
// then we don't really want to infer a base type for 'Goo'.
// However, there are a few other cases were we can infer a base type.
var syntaxFacts = document.Project.LanguageServices.GetService <ISyntaxFactsService>();
if (service.IsInCatchDeclaration(this.NameOrMemberAccessExpression))
{
this.BaseTypeOrInterfaceOpt = document.SemanticModel.Compilation.ExceptionType();
}
else if (syntaxFacts.IsAttributeName(this.NameOrMemberAccessExpression))
{
this.BaseTypeOrInterfaceOpt = document.SemanticModel.Compilation.AttributeType();
}
else if (
service.IsArrayElementType(this.NameOrMemberAccessExpression) ||
service.IsInVariableTypeContext(this.NameOrMemberAccessExpression) ||
this.ObjectCreationExpressionOpt != null)
{
var expr = this.ObjectCreationExpressionOpt ?? this.NameOrMemberAccessExpression;
var typeInference = document.Project.LanguageServices.GetService <ITypeInferenceService>();
var baseType = typeInference.InferType(document.SemanticModel, expr, objectAsDefault: true, cancellationToken: cancellationToken) as INamedTypeSymbol;
SetBaseType(baseType);
}
}