+(defcustom grep-save-buffers 'ask
+ "If non-nil, save buffers before running the grep commands.
+If `ask', ask before saving. If a function, call it with no arguments
+with each buffer current, as a predicate to determine whether that
+buffer should be saved or not. E.g., one can set this to
+ (lambda ()
+ (string-prefix-p my-grep-root (file-truename (buffer-file-name))))
+to limit saving to files located under `my-grep-root'."
+ :version "25.2"
+ :type '(choice
+ (const :tag "Ask before saving" ask)
+ (const :tag "Don't save buffers" nil)
+ function
+ (other :tag "Save all buffers" t))
+ :group 'grep)
+