3 files changed, 26 insertions, 1 deletions
diff --git a/lib/Serialization/ASTCommon.h b/lib/Serialization/ASTCommon.h
index d4166998d1..904f8ed6ae 100644
--- a/lib/Serialization/ASTCommon.h
+++ b/lib/Serialization/ASTCommon.h
@@ -23,7 +23,8 @@ namespace serialization {
 enum DeclUpdateKind {
   UPD_CXX_SET_DEFINITIONDATA,
   UPD_CXX_ADDED_IMPLICIT_MEMBER,
-  UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION
+  UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
+  UPD_CXX_ADDED_ANONYMOUS_NAMESPACE
 };
 
 TypeIdx TypeIdxFromBuiltin(const BuiltinType *BT);
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 4d2da8decb..3d4e4cdd00 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1737,6 +1737,16 @@ void ASTDeclReader::UpdateDecl(Decl *D, const RecordData &Record) {
     case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
       // It will be added to the template's specializations set when loaded.
       Reader.GetDecl(Record[Idx++]);
+      break;
+
+    case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE: {
+      NamespaceDecl *Anon = cast<NamespaceDecl>(Reader.GetDecl(Record[Idx++]));
+      if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(D))
+        TU->setAnonymousNamespace(Anon);
+      else
+        cast<NamespaceDecl>(D)->OrigOrAnonNamespace.setPointer(Anon);
+      break;
+    }
     }
   }
 }
diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index b3b55f584a..db72be3f58 100644
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Serialization/ASTWriter.h"
+#include "ASTCommon.h"
 #include "clang/AST/DeclVisitor.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclTemplate.h"
@@ -21,6 +22,7 @@
 #include "llvm/Bitcode/BitstreamWriter.h"
 #include "llvm/Support/ErrorHandling.h"
 using namespace clang;
+using namespace serialization;
 
 //===----------------------------------------------------------------------===//
 // Declaration serialization
@@ -705,6 +707,18 @@ void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
       }
     }
   }
+
+  if (Writer.hasChain() && D->isOriginalNamespace() &&
+      D->isAnonymousNamespace()) {
+    // This is an original anonymous namespace. If its parent is in a previous
+    // PCH (or is the TU), mark that parent for update.
+    Decl *Parent = cast<Decl>(D->getParent()->getPrimaryContext());
+    if (Parent->getPCHLevel() > 0) {
+      ASTWriter::UpdateRecord &Record = Writer.DeclUpdates[Parent];
+      Record.push_back(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE);
+      Writer.AddDeclRef(D, Record);
+    }
+  }
 }
 
 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {