Review

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/home/eko/MUBench/MUBench/checkouts/closure/319/original-src/com/google/javascript/jscomp/ExpressionDecomposer.java

rewriteCallExpression(Node, DecompositionState)

class ExpressionDecomposer {
  /**
   * Rewrite the call so "this" is preserved.
   *   a.b(c);
   * becomes:
   *   var temp1 = a;
   *   var temp0 = temp1.b;
   *   temp0.call(temp1,c);
   *
   * @return The replacement node.
   */
  private Node rewriteCallExpression(Node call, DecompositionState state) {
    Preconditions.checkArgument(call.getType() == Token.CALL);
    Node first = call.getFirstChild();
    Preconditions.checkArgument(NodeUtil.isGet(first));

    // Extracts the expression representing the function to call. For example:
    //   "a['b'].c" from "a['b'].c()"
    Node getVarNode = extractExpression(
        first, state.extractBeforeStatement);
    state.extractBeforeStatement = getVarNode;

    // Extracts the object reference to be used as "this". For example:
    //   "a['b']" from "a['b'].c"
    Node getExprNode = getVarNode.getFirstChild().getFirstChild();
    Preconditions.checkArgument(NodeUtil.isGet(getExprNode));
    Node thisVarNode = extractExpression(
        getExprNode.getFirstChild(), state.extractBeforeStatement);
    state.extractBeforeStatement = thisVarNode;

    // Rewrite the CALL expression.
    Node thisNameNode = thisVarNode.getFirstChild();
    Node functionNameNode = getVarNode.getFirstChild();

    // CALL
    //   GETPROP
    //     functionName
    //     "call"
    //   thisName
    //   original-parameter1
    //   original-parameter2
    //   ...
    Node newCall = new Node(Token.CALL,
        new Node(Token.GETPROP,
            functionNameNode.cloneNode(),
            Node.newString("call")),
        thisNameNode.cloneNode(), call.getLineno(), call.getCharno());

    // Throw away the call name
    call.removeFirstChild();
    if (call.hasChildren()) {
      // Add the call parameters to the new call.
      newCall.addChildrenToBack(call.removeChildren());
    }

    // Replace the call.
    Node callParent = call.getParent();
    callParent.replaceChild(call, newCall);

    return newCall;
  }

}