+ ((eq (car-safe def) 'closure) (nth 2 def))
+ ((or (and (byte-code-function-p def) (integerp (aref def 0)))
+ (subrp def))
+ (or (when preserve-names
+ (let* ((doc (condition-case nil (documentation def) (error nil)))
+ (docargs (if doc (car (help-split-fundoc doc nil))))
+ (arglist (if docargs
+ (cdar (read-from-string (downcase docargs)))))
+ (valid t))
+ ;; Check validity.
+ (dolist (arg arglist)
+ (unless (and (symbolp arg)
+ (let ((name (symbol-name arg)))
+ (if (eq (aref name 0) ?&)
+ (memq arg '(&rest &optional))
+ (not (string-match "\\." name)))))
+ (setq valid nil)))
+ (when valid arglist)))
+ (let* ((args-desc (if (not (subrp def))
+ (aref def 0)
+ (let ((a (subr-arity def)))
+ (logior (car a)
+ (if (numberp (cdr a))
+ (lsh (cdr a) 8)
+ (lsh 1 7))))))
+ (max (lsh args-desc -8))
+ (min (logand args-desc 127))
+ (rest (logand args-desc 128))
+ (arglist ()))
+ (dotimes (i min)
+ (push (intern (concat "arg" (number-to-string (1+ i)))) arglist))
+ (when (> max min)
+ (push '&optional arglist)
+ (dotimes (i (- max min))
+ (push (intern (concat "arg" (number-to-string (+ 1 i min))))
+ arglist)))
+ (unless (zerop rest) (push '&rest arglist) (push 'rest arglist))
+ (nreverse arglist))))