private async Task <Document> FixAttributeArgumentsAsync(Document document, SyntaxNode attributeDeclaration,
INamedTypeSymbol charSetType, INamedTypeSymbol dllImportType, INamedTypeSymbol marshalAsType, INamedTypeSymbol unmanagedType, CancellationToken cancellationToken)
{
DocumentEditor editor = await DocumentEditor.CreateAsync(document, cancellationToken).ConfigureAwait(false);
SyntaxGenerator generator = editor.Generator;
SemanticModel model = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
// could be either a [DllImport] or [MarshalAs] attribute
ISymbol attributeType = model.GetSymbolInfo(attributeDeclaration, cancellationToken).Symbol;
IReadOnlyList <SyntaxNode> arguments = generator.GetAttributeArguments(attributeDeclaration);
if (dllImportType.Equals(attributeType.ContainingType))
{
// [DllImport] attribute, add or replace CharSet named parameter
SyntaxNode argumentValue = generator.MemberAccessExpression(
generator.TypeExpression(charSetType),
generator.IdentifierName(UnicodeText));
SyntaxNode newCharSetArgument = generator.AttributeArgument(CharSetText, argumentValue);
SyntaxNode charSetArgument = FindNamedArgument(arguments, CharSetText);
if (charSetArgument == null)
{
// add the parameter
editor.AddAttributeArgument(attributeDeclaration, newCharSetArgument);
}
else
{
// replace the parameter
editor.ReplaceNode(charSetArgument, newCharSetArgument);
}
}
else if (marshalAsType.Equals(attributeType.ContainingType) && arguments.Count == 1)
{
// [MarshalAs] attribute, replace the only argument
SyntaxNode newArgument = generator.AttributeArgument(
generator.MemberAccessExpression(
generator.TypeExpression(unmanagedType),
generator.IdentifierName(LPWStrText)));
editor.ReplaceNode(arguments[0], newArgument);
}
return(editor.GetChangedDocument());
}