(defun sym (&rest things)
  (intern
   (string-upcase
    (with-output-to-string (s)
      (dolist (th things)
        (princ th s))))))

(defmacro define-maker (name)
  (let* ((macro-name (sym "make-" name)))
    `(defmacro ,macro-name (args &body body)
       `(make-instance ',',name
                       :fun (lambda ,args ,@body)))))

(defun generate-maker (name)
  (let* ((class-name (etypecase name
                       (symbol name)
                       (class (class-name name))))
         (macro-name (sym "make-" class-name)))
    (defmacro macro-name (args &body body)
      `(make-instance ',class-name
                      :fun (lambda ,args ,@body)))))

(defclass some-class () ((fun :initarg :fun)))

(define-maker some-class)
(generate-maker 'some-class)
(generate-maker (class-of (make-instance 'some-class)))