diff --git a/clang/Parse/ParseExpr.cpp b/clang/Parse/ParseExpr.cpp
index bb05c3546472..46bcd67f3f2c 100644
--- a/clang/Parse/ParseExpr.cpp
+++ b/clang/Parse/ParseExpr.cpp
@@ -412,6 +412,7 @@ Parser::ParseRHSOfBinaryExpression(ExprResult LHS, unsigned MinPrec) {
 /// [OBC]   '@selector' '(' objc-selector-arg ')'      [TODO]
 /// [OBC]   '@protocol' '(' identifier ')'             [TODO]
 /// [OBC]   '@encode' '(' type-name ')'                [TODO]
+/// [OBC]   objc-string-literal
 /// [C++]   'const_cast' '<' type-name '>' '(' expression ')'       [C++ 5.2p1]
 /// [C++]   'dynamic_cast' '<' type-name '>' '(' expression ')'     [C++ 5.2p1]
 /// [C++]   'reinterpret_cast' '<' type-name '>' '(' expression ')' [C++ 5.2p1]