Someone

;; Tell me if a line goes over 80 columns:

(defun is-source-buffer ()
  (or (equal mode-name "C++")
      (equal mode-name "C")
      (equal mode-name "Java")
      (equal mode-name "JavaScript")
      (equal mode-name "JDE") ; another name for java
      (equal mode-name "Python")
      (equal mode-name "Text")
      (equal mode-name "Makefile")))

(make-face 'long-line-face)
(set-face-background 'long-line-face "red")
(defvar long-line-face 'long-line-face)

(defun bmcs-font-lock-setup ()
 (let ((long-line-regexp (concat "\\(^" (make-string 80 ?.)
"\\(.*\\)\\)")))
  (if (is-source-buffer)
      (setq font-lock-keywords
            (append
             `(("TODO" (0 font-lock-warning-face t nil))
               ("FIXME" (0 font-lock-warning-face t nil))
               (,long-line-regexp (2 long-line-face prepend t)))
             (cdr font-lock-keywords))))))
(add-hook 'font-lock-mode-hook 'bmcs-font-lock-setup)

(put 'set-goal-column 'disabled nil)