Use eldoc-documentation-functions

* lisp/hexl.el (hexl-mode):
* lisp/ielm.el (inferior-emacs-lisp-mode):
* lisp/progmodes/cfengine.el (cfengine3-mode):
* lisp/progmodes/elisp-mode.el (emacs-lisp-mode):
* lisp/progmodes/octave.el (octave-mode, inferior-octave-mode):
* lisp/progmodes/python.el (python-mode):
* lisp/simple.el (read--expression): Add buffer-locally to hook
eldoc-documentation-functions.

1 files changed, 8 insertions, 6 deletions

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index ad69f8779e0..ba3cdfe17cd 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -5153,12 +5153,14 @@ returned as is."
                                                  (current-column))))
          (^ '(- (1+ (current-indentation))))))
 
-  (if (null eldoc-documentation-function)
-      ;; Emacs<25
-      (set (make-local-variable 'eldoc-documentation-function)
-           #'python-eldoc-function)
-    (add-function :before-until (local 'eldoc-documentation-function)
-                  #'python-eldoc-function))
+  (if (boundp 'eldoc-documentation-functions)
+      (add-hook 'eldoc-documentation-functions #'python-eldoc-function nil t)
+    (if (null eldoc-documentation-function)
+        ;; Emacs<25
+        (set (make-local-variable 'eldoc-documentation-function)
+             #'python-eldoc-function)
+      (add-function :before-until (local 'eldoc-documentation-function)
+                    #'python-eldoc-function)))
 
   (add-to-list
    'hs-special-modes-alist