Is there a way to verify an Antlr input file without running it?

Question

I have the following code taking the input of my input file:

var inputStream = new AntlrInputStream(File.ReadAllText(fileName));
var lexer = new LegitusLexer(inputStream);
var commonTokenStream = new CommonTokenStream(lexer);
var parser = new LegitusParser(commonTokenStream);
parser.AddErrorListener(this);

var context = parser.program();
var visitor = new LegitusVisitor(_io.GetDefaultMethods(), _io.GetDefaultVariables())
{
    Logger = _logger
};
visitor.Visit(context);

But when I call parser.program(), my program runs as it should. However, I need a way to validate that the input file is syntactically correct, so that users can verify without having to run the scripts (which run against a special machine).

Does Antlr4csharp support this easily?

Answer 1

The Antlr tool can be used to lint the source.

The only difference from a 'standard' tool run is that no output files are generated -- the warnings/errors will be the same.

For example (Java; string source content w/manually applied file 'name'):

    Tool tool = new Tool();
    tool.removeListeners();
    tool.addListener(new YourLintErrorReporter());

    ANTLRStringStream in = new ANTLRStringStream(content);
    GrammarRootAST ast = tool.parse(name, in);
    Grammar g = tool.createGrammar(ast);
    g.fileName = name; // to ensure all err msgs identify the file by name
    tool.process(g, false); // false -> lint: don't gencode

The CS implementation is equivalent.