4 files changed, 19 insertions, 4 deletions
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 02b3e51d1de..fc5ff8668e9 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4868,10 +4868,11 @@ int ASTContext::getIntegerTypeOrder(QualType LHS, QualType RHS) const {
   return 1;
 }
 
-// getCFConstantStringType - Return the type used for constant CFStrings.
-QualType ASTContext::getCFConstantStringType() const {
+TagDecl *ASTContext::getCFConstantStringDecl() const {
   if (!CFConstantStringTypeDecl) {
-    CFConstantStringTypeDecl = buildImplicitRecord("NSConstantString");
+    // This type is designed to be compatible with NSConstantString, but cannot
+    // use the same name, since NSConstantString is an interface.
+    CFConstantStringTypeDecl = buildImplicitRecord("__NSConstantString");
     CFConstantStringTypeDecl->startDefinition();
 
     QualType FieldTypes[4];
@@ -4901,7 +4902,12 @@ QualType ASTContext::getCFConstantStringType() const {
     CFConstantStringTypeDecl->completeDefinition();
   }
 
-  return getTagDeclType(CFConstantStringTypeDecl);
+  return CFConstantStringTypeDecl;
+}
+
+// getCFConstantStringType - Return the type used for constant CFStrings.
+QualType ASTContext::getCFConstantStringType() const {
+  return getTagDeclType(getCFConstantStringDecl());
 }
 
 QualType ASTContext::getObjCSuperType() const {
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 39b8cc9f0c6..3745cdd9a59 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -189,6 +189,10 @@ void Sema::Initialize() {
     DeclarationName Protocol = &Context.Idents.get("Protocol");
     if (IdResolver.begin(Protocol) == IdResolver.end())
       PushOnScopeChains(Context.getObjCProtocolDecl(), TUScope);
+
+    DeclarationName ConstantString = &Context.Idents.get("NSConstantString");
+    if (IdResolver.begin(ConstantString) == IdResolver.end())
+      PushOnScopeChains(Context.getCFConstantStringDecl(), TUScope);
   }
 
   // Initialize Microsoft "predefined C++ types".
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 72fbea6e9a8..1fbff107ea5 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -6444,6 +6444,9 @@ static Decl *getPredefinedDecl(ASTContext &Context, PredefinedDeclIDs ID) {
 
   case PREDEF_DECL_MAKE_INTEGER_SEQ_ID:
     return Context.getMakeIntegerSeqDecl();
+
+  case PREDEF_DECL_CF_CONSTANT_STRING_ID:
+    return Context.getCFConstantStringDecl();
   }
   llvm_unreachable("PredefinedDeclIDs unknown enum value");
 }
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index ec04cd6c1fa..a590e188eca 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4152,6 +4152,8 @@ uint64_t ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
   RegisterPredefDecl(Context.ExternCContext, PREDEF_DECL_EXTERN_C_CONTEXT_ID);
   RegisterPredefDecl(Context.MakeIntegerSeqDecl,
                      PREDEF_DECL_MAKE_INTEGER_SEQ_ID);
+  RegisterPredefDecl(Context.CFConstantStringTypeDecl,
+                     PREDEF_DECL_CF_CONSTANT_STRING_ID);
 
   // Build a record containing all of the tentative definitions in this file, in
   // TentativeDefinitions order.  Generally, this record will be empty for