Variable: kill-emacs-query-functions
kill-emacs-query-functions is a customizable variable defined in
files.el.gz.
Value
(org-clock-kill-emacs-query
timeclock-query-out)
Documentation
Functions to call with no arguments to query about killing Emacs.
If any of these functions returns nil, killing Emacs is canceled.
save-buffers-kill-emacs calls these functions, but kill-emacs,
the low level primitive, does not. See also kill-emacs-hook.
This variable was added, or its default value changed, in Emacs 26.1.
Probably introduced at or before Emacs version 19.23.
Source Code
;; Defined in /usr/src/emacs/lisp/files.el.gz
(defcustom kill-emacs-query-functions nil
"Functions to call with no arguments to query about killing Emacs.
If any of these functions returns nil, killing Emacs is canceled.
`save-buffers-kill-emacs' calls these functions, but `kill-emacs',
the low level primitive, does not. See also `kill-emacs-hook'."
:type 'hook
:version "26.1"
:group 'convenience)