Index: docs/LanguageExtensions.rst
===================================================================
--- docs/LanguageExtensions.rst	(revision 195153)
+++ docs/LanguageExtensions.rst	(working copy)
@@ -1843,6 +1843,19 @@
     r();
   }
 
+The ``clang::optnone`` attribute
+--------------------------------
+
+The ``clang::optnone`` attribute suppresses essentially all optimizations
+on a function or method, regardless of the optimization level applied to
+the compilation unit as a whole.  This is particularly useful when you
+need to debug a particular function, but it is infeasible to build the
+entire application without optimization.  Avoiding optimization on the
+specified function can improve the quality of the debugging information
+for that function.
+
+This attribute is incompatible with the ``always_inline`` attribute.
+
 ``gnu::`` attributes
 --------------------