RegressionTestRig.java 文件源码

/**
 * Load the parser as requested by the command line arguments, and then setup
 * the parser for the 'diagnostics', 'printTree' or 'SLL' options.
 * <p>
 * The {@link #parser} and {@link #treePrinter} variables my be null if no 
 * parser was requested (that is, if the start rule name is the 
 * LEXER_START_RULE_NAME), or if the requested parser could not be loaded or
 * instantiated.
 * <p>
 * The {@link #treePrinter} variable may also be null if the printTree option 
 * has not been requested.
 * <p>
 * @throws various exceptions while loading the parser class and instantiating
 *                 a parser instance.
 */
protected void loadParser() throws ClassNotFoundException, NoSuchMethodException, 
 InstantiationException, IllegalAccessException, InvocationTargetException {

ClassLoader cl = Thread.currentThread().getContextClassLoader();
if ( !startRuleName.equals(LEXER_START_RULE_NAME) ) {
    String parserName = grammarName+"Parser";
    parserClass = null;
    try {
      parserClass = cl.loadClass(parserName).asSubclass(Parser.class);
    }   catch (ClassNotFoundException cnfe) {
      System.err.println("ERROR: Can't load "+parserName+" as a parser");
      throw cnfe;
    }

    try {
      Constructor<? extends Parser> parserCtor = parserClass.getConstructor(TokenStream.class);
      parser = parserCtor.newInstance((TokenStream)null);
    } catch (Exception anException) {
      System.err.println("ERROR: Could not create a parser for "+parserName);
      throw anException;
    }

        if ( diagnostics ) {
        parser.getInterpreter().setPredictionMode(PredictionMode.LL_EXACT_AMBIG_DETECTION);
    }

    if ( printTree ) {
        parser.setBuildParseTree(true);
            treePrinter = new TreePrinter(primaryIndentStr,
                                          secondaryIndentStr,
                                          indentCyclePeriod,
                                          parser);
    }

    if ( trace ) {
      traceListener = new PrintStreamTraceListener(parser);
      parser.addParseListener(traceListener);
    }             

    if ( SLL ) { // overrides diagnostics
        parser.getInterpreter().setPredictionMode(PredictionMode.SLL);
    }
}
}