Enhance `c-file-style' in file/directory local variables.

cc-mode.el (c-count-cfss): New function.
(c-before-hack-hook): Call `c-set-style' differently according to whether
c-file-style was set in file or directory local variables.

2 files changed, 28 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 7d071d06e6b..c8acb06aba1 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2010-07-18  Alan Mackenzie  <acm@muc.de>
+
+        Enhance `c-file-style' in file/directory local variables.
+        * cc-mode.el (c-count-cfss): New function.
+        (c-before-hack-hook): Call `c-set-style' differently according to
+        whether c-file-style was set in file or directory local
+        variables.
+
 2010-07-18  Michael R. Mauger  <mmaug@yahoo.com>
 
         * progmodes/sql.el: Version 2.2.
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index ed769158a50..070d044c199 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -662,6 +662,17 @@ compatible with old code; callers should always specify it."
       (and (cdr rfn)
            (setq require-final-newline mode-require-final-newline)))))
 
+(defun c-count-cfss (lv-alist)
+  ;; LV-ALIST is an alist like `file-local-variables-alist'.  Count how many
+  ;; elements with the key `c-file-style' there are in it.
+  (let ((elt-ptr lv-alist) elt (cownt 0))
+    (while elt-ptr
+      (setq elt (car elt-ptr)
+            elt-ptr (cdr elt-ptr))
+      (when (eq (car elt) 'c-file-style)
+        (setq cownt (1+ cownt))))
+    cownt))
+                                                          
 (defun c-before-hack-hook ()
   "Set the CC Mode style and \"offsets\" when in the buffer's local variables.
 They are set only when, respectively, the pseudo variables
@@ -678,7 +689,15 @@ This function is called from the hook `before-hack-local-variables-hook'."
               (delq mode-cons file-local-variables-alist)))
       (when stile
         (or (stringp stile) (error "c-file-style is not a string"))
-        (c-set-style stile))
+        (if (boundp 'dir-local-variables-alist)
+            ;; Determine whether `c-file-style' was set in the file's local
+            ;; variables or in a .dir-locals.el (a directory setting).
+            (let ((cfs-in-file-and-dir-count
+                   (c-count-cfss file-local-variables-alist))
+                  (cfs-in-dir-count (c-count-cfss dir-local-variables-alist)))
+              (c-set-style stile
+                           (= cfs-in-file-and-dir-count cfs-in-dir-count)))
+          (c-set-style stile)))
       (when offsets
         (mapc
          (lambda (langentry)