Update cc-mode

bundle/bundle--package.el

@@ -73,11 +73,21 @@
          ("\\.cl$" . lisp-mode)))
 
 (use-package cc-mode
+  ;; https://www.gnu.org/prep/standards/html_node/Writing-C.html
   :ensure nil
   ;;  :hook (c-mode . eglot-ensure)
+  :hook (c-mode-common . c-toggle-auto-newline)
   :custom
-  (c-basic-offset 2)
-  (c-default-style '((c-mode . "gnu"))))
+  (fill-column 79)                      ; according to gnu style guide
+  (c-basic-offset 2)                    ; ""
+  :config
+  (defun my-c-mode-hook ()
+    (c-set-style
+     (if (and (buffer-file-name)
+              (string-match "/usr/src/linux" (buffer-file-name)))
+         "linux"
+       "gnu")))
+  (add-hook 'c-mode-hook 'my-c-mode-hook))
 
 (use-package js-mode
   :ensure nil