BatfishLexerErrorListener.java

package org.batfish.grammar;

import java.util.Arrays;
import java.util.List;

import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.batfish.common.DebugBatfishException;

public class BatfishLexerErrorListener extends BatfishGrammarErrorListener {

   public BatfishLexerErrorListener(String grammarName,
         BatfishCombinedParser<?, ?> parser) {
      super(grammarName, parser);
   }

   @Override
   public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol,
         int line, int charPositionInLine, String msg, RecognitionException e) {
      if (_syntaxErrorHandler != null && _syntaxErrorHandler.handle(recognizer,
            offendingSymbol, line, charPositionInLine, msg, e)) {
         return;
      }
      StringBuilder sb = new StringBuilder();
      BatfishParser parser = _combinedParser.getParser();
      BatfishLexer lexer = _combinedParser.getLexer();
      List<String> ruleNames = Arrays.asList(parser.getRuleNames());
      ParserRuleContext ctx = parser.getContext();
      String ruleStack = ctx.toString(ruleNames);
      sb.append("lexer: " + _grammarName + ": line " + line + ":"
            + charPositionInLine + ": " + msg + "\n");
      sb.append("Current rule stack: '" + ruleStack + "'.\n");
      if (ctx.getStart() != null) {
         sb.append("Current rule starts at: line: " + ctx.getStart().getLine()
               + ", col " + ctx.getStart().getCharPositionInLine() + "\n");
      }
      sb.append("Parse tree for current rule:\n");
      sb.append(ParseTreePrettyPrinter.print(ctx, _combinedParser) + "\n");
      sb.append("Lexer mode: " + lexer.getMode() + "\n");
      sb.append("Lexer state variables:\n");
      sb.append(lexer.printStateVariables());

      // collect context from text
      String text = _combinedParser.getInput();
      String[] lines = text.split("\n", -1);
      int errorLineIndex = line - 1;
      int errorContextStartLine = Math
            .max(errorLineIndex - _settings.getMaxParserContextLines(), 0);
      int errorContextEndLine = Math.min(
            errorLineIndex + _settings.getMaxParserContextLines(),
            lines.length);
      sb.append("Error context lines:\n");
      for (int i = errorContextStartLine; i < errorLineIndex; i++) {
         sb.append(String.format("%-11s%s\n", "   " + (i + 1) + ":", lines[i]));
      }
      sb.append(String.format("%-11s%s\n", ">>>" + (errorLineIndex + 1) + ":",
            lines[errorLineIndex]));
      for (int i = errorLineIndex + 1; i <= errorContextEndLine
            && i < lines.length; i++) {
         sb.append(String.format("%-11s%s\n", "   " + (i + 1) + ":", lines[i]));
      }

      String error = sb.toString();
      if (_settings.getThrowOnLexerError()) {
         throw new DebugBatfishException("\n" + error);
      }
      else {
         _combinedParser.getErrors().add(error);
      }
   }

}