(defmacro defalias-tmp (aliases &rest body )
  (let (defs pre post)
    (loop for (from to) in aliases
          do
          (if (fboundp from)
              (let ((tmp (gensym "original-")))
                (push `(defalias ',tmp ',from) pre)
                (push `(defalias ',from ',tmp) post)
                (push `(fmakunbound ',tmp) post))
            (push `(fmakunbound ',from) post))
          collect `(defalias ',from ,to) into defs
          finally
          (return
           `(progn
              ,@pre
              ,@defs
              (prog1 (progn ,@body)
                ,@(reverse post)))))))