Wizard To Generate declare-function calls

emacspeak-wizards.el

(defun emacspeak-wizards-gen-fn-decl (f &optional ext)
  "Generate declare-function call for function `f'.
Optional interactive prefix arg ext says this comes from an
external package."
  (interactive "SFunction:")
  (cl-assert (functionp f) t "Not a valid function")
  (let ((file (symbol-file f 'defun))
        (arglist (help-function-arglist f 'preserve)))
    (cl-assert file t "Function definition not found")
    (setq file (file-name-base file))
    (insert
     (format
      "(declare-function %s \"%s\" %s)\n"
      f
      (if ext (format "ext:%s" file) file)
      arglist ))))