3 files changed, 17 insertions, 2 deletions
diff --git a/clang/lib/Frontend/PrintPreprocessedOutput.cpp b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
index 73bca9a6caa..e68fd583aa2 100644
--- a/clang/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -137,6 +137,9 @@ public:
   /// MacroDefined - This hook is called whenever a macro definition is seen.
   void MacroDefined(const IdentifierInfo *II, const MacroInfo *MI);
 
+  /// MacroUndefined - This hook is called whenever a macro #undef is seen.
+  void MacroUndefined(SourceLocation Loc, const IdentifierInfo *II,
+                      const MacroInfo *MI);
 };
 }  // end anonymous namespace
 
@@ -280,6 +283,16 @@ void PrintPPOutputPPCallbacks::MacroDefined(const IdentifierInfo *II,
   EmittedMacroOnThisLine = true;
 }
 
+void PrintPPOutputPPCallbacks::MacroUndefined(SourceLocation Loc,
+                                              const IdentifierInfo *II,
+                                              const MacroInfo *MI) {
+  // Only print out macro definitions in -dD mode.
+  if (!DumpDefines) return;
+
+  MoveToLine(Loc);
+  OS << "#undef " << II->getName();
+  EmittedMacroOnThisLine = true;
+}
 
 void PrintPPOutputPPCallbacks::PragmaComment(SourceLocation Loc,
                                              const IdentifierInfo *Kind,
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 15ab049d26c..53619f923a9 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1508,7 +1508,8 @@ void Preprocessor::HandleUndefDirective(Token &UndefTok) {
 
   // If the callbacks want to know, tell them about the macro #undef.
   if (Callbacks)
-    Callbacks->MacroUndefined(MacroNameTok.getIdentifierInfo(), MI);
+    Callbacks->MacroUndefined(MacroNameTok.getLocation(),
+                              MacroNameTok.getIdentifierInfo(), MI);
 
   // Free macro definition.
   ReleaseMacroInfo(MI);
diff --git a/clang/lib/Lex/PreprocessingRecord.cpp b/clang/lib/Lex/PreprocessingRecord.cpp
index 6966c38b23d..c446d96b452 100644
--- a/clang/lib/Lex/PreprocessingRecord.cpp
+++ b/clang/lib/Lex/PreprocessingRecord.cpp
@@ -118,7 +118,8 @@ void PreprocessingRecord::MacroDefined(const IdentifierInfo *II,
   PreprocessedEntities.push_back(Def);
 }
 
-void PreprocessingRecord::MacroUndefined(const IdentifierInfo *II, 
+void PreprocessingRecord::MacroUndefined(SourceLocation Loc,
+                                         const IdentifierInfo *II,
                                          const MacroInfo *MI) {
   llvm::DenseMap<const MacroInfo *, MacroDefinition *>::iterator Pos
     = MacroDefinitions.find(MI);