diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index abf92948bb42..1d053411ebc2 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -1385,6 +1385,7 @@ public:
     return QualType();
   }
   void setCFConstantStringType(QualType T);
+  TagDecl *getCFConstantStringDecl() const;
 
   // This setter/getter represents the ObjC type for an NSConstantString.
   void setObjCConstantStringInterface(ObjCInterfaceDecl *Decl);
diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
index bd784c7c5c06..9e835d6d9f7a 100644
--- a/clang/include/clang/Serialization/ASTBitCodes.h
+++ b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -987,13 +987,16 @@ namespace clang {
 
       /// \brief The internal '__make_integer_seq' template.
       PREDEF_DECL_MAKE_INTEGER_SEQ_ID = 13,
+
+      /// \brief The internal '__NSConstantString' type.
+      PREDEF_DECL_CF_CONSTANT_STRING_ID = 14,
     };
 
     /// \brief The number of declaration IDs that are predefined.
     ///
     /// For more information about predefined declarations, see the
     /// \c PredefinedDeclIDs type and the PREDEF_DECL_*_ID constants.
-    const unsigned int NUM_PREDEF_DECL_IDS = 14;
+    const unsigned int NUM_PREDEF_DECL_IDS = 15;
 
     /// \brief Record code for a list of local redeclarations of a declaration.
     const unsigned int LOCAL_REDECLARATIONS = 50;
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 02b3e51d1de5..fc5ff8668e95 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 39b8cc9f0c63..3745cdd9a592 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 72fbea6e9a82..1fbff107ea5b 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 ec04cd6c1fa9..a590e188eca9 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
diff --git a/clang/test/CodeGenObjC/2010-02-01-utf16-with-null.m b/clang/test/CodeGenObjC/2010-02-01-utf16-with-null.m
index 46ce3b289fc1..856ac9ac97bd 100644
--- a/clang/test/CodeGenObjC/2010-02-01-utf16-with-null.m
+++ b/clang/test/CodeGenObjC/2010-02-01-utf16-with-null.m
@@ -2,6 +2,6 @@
 // rdar://7589850
 
 // CHECK: @.str = private unnamed_addr constant [9 x i16] [i16 103, i16 111, i16 111, i16 100, i16 0, i16 98, i16 121, i16 101, i16 0], section "__TEXT,__ustring", align 2
-// CHECK: @_unnamed_cfstring_ = private constant %struct.NSConstantString { i32* getelementptr inbounds ([0 x i32], [0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 2000, i8* bitcast ([9 x i16]* @.str to i8*), i32 8 }, section "__DATA,__cfstring"
-// CHECK: @P = global i8* bitcast (%struct.NSConstantString* @_unnamed_cfstring_ to i8*), align 4
+// CHECK: @_unnamed_cfstring_ = private constant %struct.__NSConstantString { i32* getelementptr inbounds ([0 x i32], [0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 2000, i8* bitcast ([9 x i16]* @.str to i8*), i32 8 }, section "__DATA,__cfstring"
+// CHECK: @P = global i8* bitcast (%struct.__NSConstantString* @_unnamed_cfstring_ to i8*), align 4
 void *P = @"good\0bye";
diff --git a/clang/test/CodeGenObjC/arc-no-arc-exceptions.m b/clang/test/CodeGenObjC/arc-no-arc-exceptions.m
index 82977b0a1751..30424e7fb361 100644
--- a/clang/test/CodeGenObjC/arc-no-arc-exceptions.m
+++ b/clang/test/CodeGenObjC/arc-no-arc-exceptions.m
@@ -34,7 +34,7 @@ void test1(id x) {
 void NSLog(id, ...);
 
 // CHECK-LABEL: define void @test2(
-// CHECK: invoke void (i8*, ...) @NSLog(i8* bitcast (%struct.NSConstantString* @_unnamed_cfstring_ to i8*), i32* %{{.*}})
+// CHECK: invoke void (i8*, ...) @NSLog(i8* bitcast (%struct.__NSConstantString* @_unnamed_cfstring_ to i8*), i32* %{{.*}})
 // CHECK:   to label %{{.*}} unwind label %{{.*}}, !clang.arc.no_objc_arc_exceptions !
 // NO-METADATA-LABEL: define void @test2(
 // NO-METADATA-NOT: !clang.arc.no_objc_arc_exceptions
diff --git a/clang/test/CodeGenObjC/tentative-cfconstantstring.m b/clang/test/CodeGenObjC/tentative-cfconstantstring.m
index 5b3c3bd92494..0c692c37c955 100644
--- a/clang/test/CodeGenObjC/tentative-cfconstantstring.m
+++ b/clang/test/CodeGenObjC/tentative-cfconstantstring.m
@@ -32,12 +32,12 @@ static inline void _inlineFunction() {
 @end
 
 // CHECK: @__CFConstantStringClassReference = common global [24 x i32] zeroinitializer, align 16
-// CHECK: @_unnamed_cfstring_{{.*}} = private constant %struct.NSConstantString { i32* getelementptr inbounds ([24 x i32], [24 x i32]* @__CFConstantStringClassReference, i32 0, i32 0)
+// CHECK: @_unnamed_cfstring_{{.*}} = private constant %struct.__NSConstantString { i32* getelementptr inbounds ([24 x i32], [24 x i32]* @__CFConstantStringClassReference, i32 0, i32 0)
 
 // CHECK-LABEL: define internal void @_inlineFunction()
 // CHECK:  [[ZERO:%.*]] = load %struct._class_t*, %struct._class_t** @"OBJC_CLASSLIST_REFERENCES_
 // CHECK-NEXT:   [[ONE:%.*]] = load i8*, i8** @OBJC_SELECTOR_REFERENCES_
 // CHECK-NEXT:   [[TWO:%.*]] = bitcast %struct._class_t* [[ZERO]] to i8*
-// CHECK-NEXT:   call void (i8*, i8*, [[T:%.*]]*, ...) bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*, [[T:%.*]]*, ...)*)(i8* [[TWO]], i8* [[ONE]], [[T:%.*]]* bitcast (%struct.NSConstantString* @_unnamed_cfstring_{{.*}} to [[T:%.*]]*))
+// CHECK-NEXT:   call void (i8*, i8*, [[T:%.*]]*, ...) bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*, [[T:%.*]]*, ...)*)(i8* [[TWO]], i8* [[ONE]], [[T:%.*]]* bitcast (%struct.__NSConstantString* @_unnamed_cfstring_{{.*}} to [[T:%.*]]*))
 // CHECK-NEXT:   ret void
 
diff --git a/clang/test/Modules/Inputs/builtin.h b/clang/test/Modules/Inputs/builtin.h
index 7be90177d194..d87794523420 100644
--- a/clang/test/Modules/Inputs/builtin.h
+++ b/clang/test/Modules/Inputs/builtin.h
@@ -1,3 +1,10 @@
 int i;
 int *p = &i;
 
+#ifdef __OBJC__
+void use_constant_string_builtins(void) {
+  (void)__builtin___CFStringMakeConstantString("");
+  (void)__builtin___NSStringMakeConstantString("");
+}
+#endif
+
diff --git a/clang/test/Modules/builtins.m b/clang/test/Modules/builtins.m
index 33d23979ce79..a835039cc60b 100644
--- a/clang/test/Modules/builtins.m
+++ b/clang/test/Modules/builtins.m
@@ -1,3 +1,17 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules-cache-path=%t -fmodules -fimplicit-module-maps -I %S/Inputs %s -verify
+
+// RUN: rm -rf %t.pch.cache
+// RUN: %clang_cc1 -fmodules-cache-path=%t.pch.cache -fmodules -fimplicit-module-maps -I %S/Inputs -emit-pch -o %t.pch -x objective-c-header %S/Inputs/use-builtin.h
+// RUN: %clang_cc1 -fmodules-cache-path=%t.pch.cache -fmodules -fimplicit-module-maps -I %S/Inputs %s -include-pch %t.pch %s -verify
+
+// expected-no-diagnostics
+
+void use_constant_string_builtins1(void) {
+  (void)__builtin___CFStringMakeConstantString("");
+  (void)__builtin___NSStringMakeConstantString("");
+}
+
 @import builtin;
 
 int foo() {
@@ -14,11 +28,7 @@ int baz() {
   return IS_CONST(0);
 }
 
-// RUN: rm -rf %t
-// RUN: %clang_cc1 -fmodules-cache-path=%t -fmodules -fimplicit-module-maps -I %S/Inputs %s -verify
-
-// RUN: rm -rf %t.pch.cache
-// RUN: %clang_cc1 -fmodules-cache-path=%t.pch.cache -fmodules -fimplicit-module-maps -I %S/Inputs -emit-pch -o %t.pch -x objective-c-header %S/Inputs/use-builtin.h
-// RUN: %clang_cc1 -fmodules-cache-path=%t.pch.cache -fmodules -fimplicit-module-maps -I %S/Inputs %s -include-pch %t.pch %s -verify
-
-// expected-no-diagnostics
+void use_constant_string_builtins2(void) {
+  (void)__builtin___CFStringMakeConstantString("");
+  (void)__builtin___NSStringMakeConstantString("");
+}