internal override Task <Document> GetUpdatedDocumentAsync(Document document, SemanticModel model, SyntaxNode root, SyntaxNode nodeToFix, Diagnostic diagnostic, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
var charSetType = WellKnownTypes.CharSet(model.Compilation);
var dllImportType = WellKnownTypes.DllImportAttribute(model.Compilation);
var marshalAsType = WellKnownTypes.MarshalAsAttribute(model.Compilation);
var unmanagedType = WellKnownTypes.UnmanagedType(model.Compilation);
if (charSetType == null || dllImportType == null || marshalAsType == null || unmanagedType == null)
{
return(Task.FromResult(document));
}
var syntaxFactoryService = document.Project.LanguageServices.GetService <SyntaxGenerator>();
// return the unchanged root if no fix is available
var newRoot = root;
if (nodeToFix.Kind() == SyntaxKind.Attribute)
{
// could be either a [DllImport] or [MarshalAs] attribute
var attribute = (AttributeSyntax)nodeToFix;
var attributeType = model.GetSymbolInfo(attribute).Symbol;
var arguments = attribute.ArgumentList.Arguments;
if (dllImportType.Equals(attributeType.ContainingType))
{
// [DllImport] attribute, add or replace CharSet named parameter
var argumentValue = CreateCharSetArgument(syntaxFactoryService, charSetType).WithAdditionalAnnotations(Formatter.Annotation);
var namedParameter = arguments.FirstOrDefault(arg => arg.NameEquals != null && arg.NameEquals.Name.Identifier.Text == CharSetText);
if (namedParameter == null)
{
// add the parameter
namedParameter = SyntaxFactory.AttributeArgument(SyntaxFactory.NameEquals(CharSetText), null, (ExpressionSyntax)argumentValue)
.WithAdditionalAnnotations(Formatter.Annotation);
var newArguments = arguments.Add(namedParameter);
var newArgumentList = attribute.ArgumentList.WithArguments(newArguments);
newRoot = root.ReplaceNode(attribute.ArgumentList, newArgumentList);
}
else
{
// replace the parameter
var newNamedParameter = namedParameter.WithExpression((ExpressionSyntax)argumentValue);
newRoot = root.ReplaceNode(namedParameter, newNamedParameter);
}
}
else if (marshalAsType.Equals(attributeType.ContainingType) && arguments.Count == 1)
{
// [MarshalAs] attribute, replace the only argument
var newExpression = CreateMarshalAsArgument(syntaxFactoryService, unmanagedType)
.WithLeadingTrivia(arguments[0].GetLeadingTrivia())
.WithTrailingTrivia(arguments[0].GetTrailingTrivia());
var newArgument = arguments[0].WithExpression((ExpressionSyntax)newExpression);
newRoot = root.ReplaceNode(arguments[0], newArgument);
}
}
return(Task.FromResult(document.WithSyntaxRoot(newRoot)));
}
