Tweak Flymake autoloads and dependencies

* lisp/progmodes/elisp-mode.el (emacs-lisp-mode): Add to
flymake-diagnostic-functions here.

* lisp/progmodes/flymake-elisp.el[top]: Don't add to
emacs-lisp-mode-hook.  Don't call flymake-elisp-setup-backends in
every buffer.  (flymake-elisp-checkdoc) (flymake-elisp-byte-compile):
Autoload.  (flymake-elisp-setup-backends): Remove.

* lisp/progmodes/flymake.el: Add some top-level comments.
(flymake-make-diagnostic)
(flymake-mode, flymake-mode-on, flymake-mode-off): Add autoloads

Where to fixup this shit?

lisp/progmodes/elisp-mode.el

@@ -243,7 +243,9 @@ Blank lines separate paragraphs.  Semicolons start comments.
   (add-hook 'xref-backend-functions #'elisp--xref-backend nil t)
   (setq-local project-vc-external-roots-function #'elisp-load-path-roots)
   (add-hook 'completion-at-point-functions
-            #'elisp-completion-at-point nil 'local))
+            #'elisp-completion-at-point nil 'local)
+  (add-hook 'flymake-diagnostic-functions #'flymake-elisp-checkdoc nil t)
+  (add-hook 'flymake-diagnostic-functions #'flymake-elisp-byte-compile nil t))
 
 ;; Font-locking support.
 

lisp/progmodes/flymake-elisp.el

@@ -20,7 +20,8 @@
 
 ;;; Commentary:
 
-;; Flymake backends for elisp work.
+;; Flymake backends for elisp work, `flymake-elisp-checkdoc' and
+;; `flymake-elisp-byte-compile'.
 
 ;;; Code:
 (require 'flymake)
@@ -45,6 +46,7 @@
           (kill-buffer buf))))
     collected))
 
+;;;###autoload
 (defun flymake-elisp-checkdoc (report-fn)
   "A Flymake backend for `checkdoc'.
 Calls REPORT-FN directly."
@@ -98,6 +100,7 @@ Calls REPORT-FN directly."
 (defvar-local flymake-elisp--byte-compile-process nil
   "Buffer-local process started for byte-compiling the buffer.")
 
+;;;###autoload
 (defun flymake-elisp-byte-compile (report-fn)
   "A Flymake backend for elisp byte compilation.
 Spawn an Emacs process that byte-compiles a file representing the
@@ -177,18 +180,5 @@ Runs in a batch-mode Emacs.  Interactively use variable
     (terpri)
     (pp collected)))
 
-(defun flymake-elisp-setup-backends ()
-  "Setup Flymake for elisp work."
-  (add-hook 'flymake-diagnostic-functions 'flymake-elisp-checkdoc t t)
-  (add-hook 'flymake-diagnostic-functions 'flymake-elisp-byte-compile t t))
-
-(add-hook 'emacs-lisp-mode-hook
-          'flymake-elisp-setup-backends)
-
-(dolist (buffer (buffer-list))
-  (with-current-buffer buffer
-    (when (derived-mode-p 'emacs-lisp-mode)
-      (flymake-elisp-setup-backends))))
-
 (provide 'flymake-elisp)
 ;;; flymake-elisp.el ends here

lisp/progmodes/flymake.el

@@ -26,9 +26,21 @@
 ;;
 ;; Flymake is a minor Emacs mode performing on-the-fly syntax checks.
 ;;
+;; Flymake collects diagnostic information for multiple sources,
+;; called backends, and visually annotates the relevant portions in
+;; the buffer.
+;;
 ;; This file contains the UI for displaying and interacting with the
-;; results of such checks, as well as entry points for backends to
-;; hook on to. Backends are sources of diagnostic info.
+;; results produced by these backends, as well as entry points for
+;; backends to hook on to.
+;;
+;; The main entry points are `flymake-mode' and `flymake-start'
+;;
+;; The docstrings of these variabless are relevant to understanding how
+;; Flymake works for both the user and the backend programmer:
+;;
+;; * `flymake-diagnostic-functions'
+;; * `flymake-diagnostic-types-alist'
 ;;
 ;;; Code:
 
@@ -195,6 +207,7 @@ generated it."
                (:constructor flymake--diag-make))
   buffer beg end type text backend)
 
+;;;###autoload
 (defun flymake-make-diagnostic (buffer
                                 beg
                                 end
@@ -681,9 +694,8 @@ Interactively, with a prefix arg, FORCE is t."
       (start))))
 
 (defvar flymake-mode-map
-  (let ((map (make-sparse-keymap)))
-    map)
-  "Keymap for `flymake-mode'.")
+  (let ((map (make-sparse-keymap))) map)
+  "Keymap for `flymake-mode'")
 
 ;;;###autoload
 (define-minor-mode flymake-mode nil
@@ -770,7 +782,6 @@ Do it only if `flymake-no-changes-timeout' is non-nil."
     (cancel-timer flymake-timer)
     (setq flymake-timer nil)))
 
-;;;###autoload
 (defun flymake-find-file-hook ()
   (unless (or flymake-mode
               (null flymake-diagnostic-functions))
@@ -956,11 +967,8 @@ applied."
                         '(:propertize " "))
              (:propertize "]")))))))
 
-
-
-
 (provide 'flymake)
 
 (require 'flymake-proc)
-(require 'flymake-elisp)
+
 ;;; flymake.el ends here