3 files changed, 13 insertions, 0 deletions
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp
index 50929158b24..7557f2e0fe0 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -51,9 +51,13 @@ void Preprocessor::setMacroInfo(IdentifierInfo *II, MacroInfo *MI) {
   if (MI) {
     Macros[II] = MI;
     II->setHasMacroDefinition(true);
+    if (II->isFromAST())
+      II->setChangedSinceDeserialization();
   } else if (II->hasMacroDefinition()) {
     Macros.erase(II);
     II->setHasMacroDefinition(false);
+    if (II->isFromAST())
+      II->setChangedSinceDeserialization();
   }
 }
 
diff --git a/clang/lib/Lex/Pragma.cpp b/clang/lib/Lex/Pragma.cpp
index f6532c2175a..cc612fff9ff 100644
--- a/clang/lib/Lex/Pragma.cpp
+++ b/clang/lib/Lex/Pragma.cpp
@@ -304,6 +304,8 @@ void Preprocessor::HandlePragmaPoison(Token &PoisonTok) {
 
     // Finally, poison it!
     II->setIsPoisoned();
+    if (II->isFromAST())
+      II->setChangedSinceDeserialization();
   }
 }
 
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 31662ad0c11..af0faca43b9 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -492,6 +492,13 @@ void Preprocessor::HandleIdentifier(Token &Identifier) {
 
   IdentifierInfo &II = *Identifier.getIdentifierInfo();
 
+  // If the information about this identifier is out of date, update it from
+  // the external source.
+  if (II.isOutOfDate()) {
+    ExternalSource->updateOutOfDateIdentifier(II);
+    Identifier.setKind(II.getTokenID());
+  }
+  
   // If this identifier was poisoned, and if it was not produced from a macro
   // expansion, emit an error.
   if (II.isPoisoned() && CurPPLexer) {