Make Emacs 20 compat code in derived.el obsolete

* lisp/emacs-lisp/derived.el (derived-mode-setup-function-name):
Declare obsolete.  This was for compatibility with Emacs 20 or older.

diff --git a/lisp/emacs-lisp/derived.el b/lisp/emacs-lisp/derived.el
index 3eafad177dda3e7991be6c7500379f05ec48e1fc..6a11f1c394938856ec64baba25efa85f1d2328de 100644 (file)
--- a/lisp/emacs-lisp/derived.el
+++ b/lisp/emacs-lisp/derived.el
@@ -364,6 +364,7 @@ which more-or-less shadow%s %s's corresponding table%s."
 
 (defsubst derived-mode-setup-function-name (mode)
   "Construct a setup-function name based on a MODE name."
+  (declare (obsolete nil "28.1"))
   (intern (concat (symbol-name mode) "-setup")))
 
 \f