(defmacro save-variables (syms &body body)
  (let* ((l (length syms))
         (gs (loop :repeat l
                   :collect (gensym)))
         (saves (loop :for g :in gs
                      :for s :in syms
                      :collect `(,g ,s)))
         (restores (loop :for g :in gs
                         :for s :in syms
                         :collect `(setf ,s ,g))))
    `(let ,saves
       ,@body
       ,@restores)))