[
 (program) {
  (stmt_list) {
   (stmt_list) {
    (stmt_or_defined_macro) {
     (stmt) {
      (switch_stmt) {
       switch
       (
       a
       )
       {
       }
      }
     }
    }
   }
   (stmt_or_defined_macro) {
    (stmt) {
     ;
    }
   }
  }
 }
]