[flang] Provide an emacs style for editing Flang C++ sources

Original-commit: flang-compiler/f18@e9922dda1d
Reviewed-on: https://github.com/flang-compiler/f18/pull/24
Tree-same-pre-rewrite: false

flang/documentation/flang-c-style.el

@@ -0,0 +1,31 @@
+
+;; Define a cc-mode style for editing C++ codes in Flang.
+;;
+;; Inspired from LLVM style in
+;;    https://github.com/llvm-mirror/llvm/blob/master/utils/emacs/emacs.el
+;;
+
+(c-add-style "flang"
+             '("gnu"
+	       (fill-column . 80)
+	       (c++-indent-level . 2)
+	       (c-basic-offset . 2)
+	       (indent-tabs-mode . nil)
+	       (c-offsets-alist .
+                   ((arglist-intro . ++) 
+                    (innamespace . 0)
+                    (member-init-intro . ++)
+                    ))
+               ))
+
+
+;;
+;; Use the following to make it the default.  
+;;
+
+(defun flang-c-mode-hook ()
+  (c-set-style "flang")
+  )
+
+(add-hook 'c-mode-hook   'flang-c-mode-hook)
+(add-hook 'c++-mode-hook 'flang-c-mode-hook)