DebugMessages

Sometimes you want to find out where a particular error, warning or just plain annoying message in Messages is coming from.

This piece of advice allows you to see the function call sequence that resulted in each message in the Messages buffer:

  (defadvice message (before who-said-that activate)
    "Find out who said that thing. and say so."
    (let ((trace nil) (n 1) (frame nil))
      (while (setq frame (backtrace-frame n))
        (setq n     (1+ n) 
              trace (cons (cadr frame) trace)) )
      (ad-set-arg 0 (concat "<<%S>>:\n" (ad-get-arg 0)))
      (ad-set-args 1 (cons trace (ad-get-args 1))) ))

To deactivate this, call

   (ad-disable-advice 'message 'before 'who-said-that)
   (ad-update 'message)

Similarly, to get timestamps:

  (defadvice message (before when-was-that activate)
    "Add timestamps to `message' output."
    (ad-set-arg 0 (concat (format-time-string "[%Y-%m-%d %T %Z] ") 
                          (ad-get-arg 0)) ))

And to deactivate this, call

    (ad-disable-advice 'message 'before 'when-was-that)
    (ad-update 'message)

prin1

message requires a string, but you can use prin1 to print a string representation of an object. See http://www.gnu.org/software/emacs/manual/html_node/elisp/Output-Functions.html


CategoryDebug