private static (IParseTree parseTree, TokenStreamRewriter rewriter) ParseInternal(ParserMode mode, VBAParser parser, CommonTokenStream tokenStream, ParserStartRule startRule)
{
if (mode == ParserMode.Ll)
{
parser.Interpreter.PredictionMode = PredictionMode.Ll;
}
else
{
parser.Interpreter.PredictionMode = PredictionMode.Sll;
}
var tree = startRule.Invoke(parser);
return(tree, new TokenStreamRewriter(tokenStream));
}
/// <summary>
/// Parses the supplied code.
/// </summary>
/// <param name="code">The code to parse.</param>
/// <param name="startRule">The parser rule to begin the process with.</param>
/// <param name="mode">(Optional) The parser mode to run.</param>
public static (IParseTree parseTree, TokenStreamRewriter rewriter) Parse(string code, ParserStartRule startRule, ParserMode mode = ParserMode.Default)
{
var tokenStreamProvider = new SimpleVBAModuleTokenStreamProvider();
var tokenStream = tokenStreamProvider.Tokens(code ?? string.Empty);
var parser = new VBAParser(tokenStream);
try
{
return(ParseInternal(ParserMode.Sll, parser, tokenStream, startRule));
}
catch (ParsePassSyntaxErrorException exception)
{
var actualMode = parser.Interpreter.PredictionMode.ToString().ToUpperInvariant();
System.Diagnostics.Debug.Assert(actualMode == ParserMode.Sll.ToString().ToUpperInvariant());
var message = $"{actualMode} mode failed while parsing the code at symbol {exception.OffendingSymbol.Text} at L{exception.LineNumber}C{exception.Position}. Retrying using LL.";
LogAndReset(message, exception, parser, tokenStream);
if (parser.Interpreter.PredictionMode == PredictionMode.Sll)
{
return(ParseInternal(ParserMode.Ll, parser, tokenStream, startRule));
}
}
catch (Exception exception)
{
var actualMode = parser.Interpreter.PredictionMode.ToString().ToUpperInvariant();
System.Diagnostics.Debug.Assert(actualMode == ParserMode.Sll.ToString().ToUpperInvariant());
var message = $"{actualMode} mode threw an exception. Retrying LL mode.";
LogAndReset(message, exception, parser, tokenStream);
if (parser.Interpreter.PredictionMode == PredictionMode.Sll)
{
return(ParseInternal(ParserMode.Ll, parser, tokenStream, startRule));
}
}
return(null, null);
}
