private void addSetRCols(ASTNode node, Set<String> setRCols) {

    // See if this node is a TOK_TABLE_OR_COL.  If so, find the value and put it in the list.  If
    // not, recurse on any children
    if (node.getToken().getType() == HiveParser.TOK_TABLE_OR_COL) {
      ASTNode colName = (ASTNode)node.getChildren().get(0);
      if (colName.getToken().getType() == HiveParser.TOK_DEFAULT_VALUE) {
        return;
      }

      assert colName.getToken().getType() == HiveParser.Identifier :
          "Expected column name";
      setRCols.add(normalizeColName(colName.getText()));
    } else if (node.getChildren() != null) {
      for (Node n : node.getChildren()) {
        addSetRCols((ASTNode)n, setRCols);
      }
    }
  }
Check that {@code readEntity} is also being written.
ql/src/java/org/apache/hadoop/hive/ql/parse/RewriteSemanticAnalyzer.java