ExpressionPtr ClassConstantExpression::preOptimize(AnalysisResultPtr ar) {
  if (ar->getPhase() < AnalysisResult::FirstPreOptimize) {
    return ExpressionPtr();
  }
  if (m_redeclared) return ExpressionPtr();
  ClassScopePtr cls = ar->resolveClass(m_className);
  if (!cls || cls->isRedeclaring()) return ExpressionPtr();
  ConstantTablePtr constants = cls->getConstants();
  if (constants->isExplicitlyDeclared(m_varName)) {
    ConstructPtr decl = constants->getValue(m_varName);
    if (decl) {
      ExpressionPtr value = dynamic_pointer_cast<Expression>(decl);
      if (!m_visited) {
        m_visited = true;
        ar->pushScope(cls);
        ExpressionPtr optExp = value->preOptimize(ar);
        ar->popScope();
        m_visited = false;
        if (optExp) value = optExp;
      }
      if (value->isScalar()) {
        // inline the value
        if (value->is(Expression::KindOfScalarExpression)) {
          ScalarExpressionPtr exp =
            dynamic_pointer_cast<ScalarExpression>(Clone(value));
          exp->setComment(getText());
          return exp;
        } else if (value->is(Expression::KindOfConstantExpression)) {
          // inline the value
          ConstantExpressionPtr exp =
            dynamic_pointer_cast<ConstantExpression>(Clone(value));
          exp->setComment(getText());
          return exp;
        }
      }
    }
  }
  return ExpressionPtr();
}