2 files changed, 30 insertions, 0 deletions
diff --git a/clang/include/clang/Parse/Action.h b/clang/include/clang/Parse/Action.h
index ba480c5b7c4..47583993bc2 100644
--- a/clang/include/clang/Parse/Action.h
+++ b/clang/include/clang/Parse/Action.h
@@ -637,6 +637,18 @@ public:
   // Expression Parsing Callbacks.
   //===--------------------------------------------------------------------===//
 
+  /// \brief Notifies the action when the parser is processing an unevaluated
+  /// operand.
+  ///
+  /// \param UnevaluatedOperand true to indicate that the parser is processing
+  /// an unevaluated operand, or false otherwise.
+  ///
+  /// \returns whether the the action module was previously in an unevaluated
+  /// operand.
+  virtual bool setUnevaluatedOperand(bool UnevaluatedOperand) { 
+    return false;
+  }
+  
   // Primary Expressions.
 
   /// \brief Retrieve the source range that corresponds to the given
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index d613ae13293..75458d821e8 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -105,6 +105,24 @@ class Parser {
     }
   };
 
+  /// \brief RAII object that enters an unevaluated operand.
+  class EnterUnevaluatedOperand {    
+    /// \brief The action object.
+    Action &Actions;
+    
+    /// \brief Whether we were previously within an unevaluated operand.
+    bool PreviouslyInUnevaluatedOperand;
+    
+  public:
+    explicit EnterUnevaluatedOperand(Action &Actions) : Actions(Actions) { 
+      PreviouslyInUnevaluatedOperand = Actions.setUnevaluatedOperand(true);
+    }
+    
+    ~EnterUnevaluatedOperand() {
+      Actions.setUnevaluatedOperand(PreviouslyInUnevaluatedOperand);
+    }
+  };
+  
 public:
   Parser(Preprocessor &PP, Action &Actions);
   ~Parser();