Review

7

com/google/javascript/jscomp/SourceMap2.java

addMapping(Node, Position, Position)

class SourceMap2 {
  /**
   * Adds a mapping for the given node.  Mappings must be added in order.
   *
   * @param node The node that the new mapping represents.
   * @param startPosition The position on the starting line
   * @param endPosition The position on the ending line.
   */
  public void addMapping(Node node, Position startPosition, Position endPosition) {
    String sourceFile = (String)node.getProp(Node.SOURCENAME_PROP);

    // If the node does not have an associated source file or
    // its line number is -1, then the node does not have sufficient
    // information for a mapping to be useful.
    if (sourceFile == null || node.getLineno() < 0) {
      return;
    }

    if (sourceFile != lastSourceFile) {
      lastSourceFile = sourceFile;
      Integer index = source_file_map.get(sourceFile);
      if (index != null) {
        lastSourceFileIndex = index;
      } else {
        lastSourceFileIndex = source_file_map.size();
        source_file_map.put(sourceFile, lastSourceFileIndex);
      }
    }

    // Create the new mapping.
    Mapping mapping = new Mapping();
    mapping.sourceFile = lastSourceFileIndex;
    mapping.originalPosition = new Position(node.getLineno(), node.getCharno());

    String originalName = (String)node.getProp(Node.ORIGINALNAME_PROP);
    if (originalName != null) {
      mapping.originalName = originalName;
    }

    if (offsetPosition.getLineNumber() == 0
        && offsetPosition.getCharacterIndex() == 0) {
      mapping.startPosition = startPosition;
      mapping.endPosition = endPosition;
    } else {
      // If the mapping is found on the first line, we need to offset
      // its character position by the number of characters found on
      // the *last* line of the source file to which the code is
      // being generated.
      int offsetLine = offsetPosition.getLineNumber();
      int startOffsetPosition = offsetPosition.getCharacterIndex();
      int endOffsetPosition = offsetPosition.getCharacterIndex();

      if (startPosition.getLineNumber() > 0) {
        startOffsetPosition = 0;
      }

      if (endPosition.getLineNumber() > 0) {
        endOffsetPosition = 0;
      }

      mapping.startPosition =
          new Position(startPosition.getLineNumber() + offsetLine,
                       startPosition.getCharacterIndex() + startOffsetPosition);

      mapping.endPosition =
          new Position(endPosition.getLineNumber() + offsetLine,
                       endPosition.getCharacterIndex() + endOffsetPosition);
    }

    // Validate the mappings are in a proper order.
    if (lastMapping != null) {
      int lastLine = lastMapping.startPosition.getLineNumber();
      int lastColumn = lastMapping.startPosition.getCharacterIndex();
      int nextLine = mapping.startPosition.getLineNumber();
      int nextColumn = mapping.startPosition.getCharacterIndex();
      Preconditions.checkState(nextLine > lastLine
          || (nextLine == lastLine && nextColumn >= lastColumn),
          "Incorrect source mappings order, previous : (%s,%s)\n"
          + "new : (%s,%s)\nnode : %s",
          lastLine, lastColumn, nextLine, nextColumn, node);
    }

    lastMapping = mapping;
    mappings.add(mapping);
  }

}