* lisp/progmodes/ruby-mode.el (ruby-font-lock-keywords): Highlight

regexp options.

Fixes: debbugs:16914

3 files changed, 19 insertions, 0 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d3419412ebe..d25f877a644 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-03-01  Dmitry Gutov  <dgutov@yandex.ru>
+
+        * progmodes/ruby-mode.el (ruby-font-lock-keywords): Highlight
+        regexp options.  (Bug#16914)
+
 2014-03-01  Martin Rudalics  <rudalics@gmx.at>
 
         * window.el (window--max-delta-1): Round down when calculating
diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index 5cd054a22a8..a5d8285c98e 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -2132,6 +2132,16 @@ See `font-lock-syntax-table'.")
     ;; Character literals.
     ;; FIXME: Support longer escape sequences.
     ("\\_<\\?\\\\?\\S " 0 font-lock-string-face)
+    ;; Regexp options.
+    ("\\(?:\\s|\\|/\\)\\([imxo]+\\)"
+     1 (when (save-excursion
+               (let ((state (syntax-ppss (match-beginning 0))))
+                 (and (nth 3 state)
+                      (or (eq (char-after) ?/)
+                          (progn
+                            (goto-char (nth 8 state))
+                            (looking-at "%r"))))))
+         font-lock-preprocessor-face))
     )
   "Additional expressions to highlight in Ruby mode.")
 
diff --git a/test/indent/ruby.rb b/test/indent/ruby.rb
index daec1c30c69..2ca0e482797 100644
--- a/test/indent/ruby.rb
+++ b/test/indent/ruby.rb
@@ -29,6 +29,10 @@ a = asub / aslb + bsub / bslb;
 # Highlight the regexp after "if".
 x = toto / foo if /do bar/ =~ "dobar"
 
+# Regexp options are highlighted.
+
+/foo/xi != %r{bar}mo.tee
+
 bar(class: XXX) do              # ruby-indent-keyword-label
   foo
 end