Dedicated compile hook on compilation finish

Question

I use the compilation-finish-functions hook to perform some actions once compilation finishes. However, unexpectedly to me the hook is also triggered when rgrep completes.

I can't seem to find a more appropriate hook for what I'm after, namely a hook that is triggered only when compile's compilation completes.

Is there such a hook or must I take this into consideration in my hooked functions?

This is how I hook my function (Emacs 25.1.1):

(defun display-piped-output (buffer msg)
  (unless (string-match "^finished" msg)
    (switch-to-buffer "test.log")))

(define-minor-mode moscow-compilation-mode
  "Expect compilation output piped to file"
  :global t
  (if moscow-compilation-mode
      (add-hook 'compilation-finish-functions 'display-piped-output)
    (remove-hook 'compilation-finish-functions 'display-piped-output)))

Answer 1

rgrep and similar use compile, this is why hooks in compilation-finish-functions are triggered. When rgrep successfully completes its message is "finished\n".

You must take this into consideration in your hook by checking buffer:

(defun display-piped-output (buffer msg)
  (unless (and
           (string-match "^finished" msg))
           (not (string= (buffer-name buffer) "*grep*"))
    (switch-to-buffer "test.log")))