1 files changed, 13 insertions, 0 deletions
diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 737a152650..6589f84c93 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -121,6 +121,13 @@ class Preprocessor : public RefCountedBase<Preprocessor> {
   /// DisableMacroExpansion - True if macro expansion is disabled.
   bool DisableMacroExpansion : 1;
 
+  /// MacroExpansionInDirectivesOverride - Temporarily disables
+  /// DisableMacroExpansion (i.e. enables expansion) when parsing preprocessor
+  /// directives.
+  bool MacroExpansionInDirectivesOverride : 1;
+
+  class ResetMacroExpansionHelper;
+
   /// \brief Whether we have already loaded macros from the external source.
   mutable bool ReadMacrosFromExternalSource : 1;
 
@@ -643,6 +650,12 @@ public:
     while (Result.getKind() == tok::comment);
   }
 
+  /// Disables macro expansion everywhere except for preprocessor directives.
+  void SetMacroExpansionOnlyInDirectives() {
+    DisableMacroExpansion = true;
+    MacroExpansionInDirectivesOverride = true;
+  }
+
   /// LookAhead - This peeks ahead N tokens and returns that token without
   /// consuming any tokens.  LookAhead(0) returns the next token that would be
   /// returned by Lex(), LookAhead(1) returns the token after it, etc.  This