diff --git a/clang/include/clang/CodeGen/CodeGenABITypes.h b/clang/include/clang/CodeGen/CodeGenABITypes.h
--- a/clang/include/clang/CodeGen/CodeGenABITypes.h
+++ b/clang/include/clang/CodeGen/CodeGenABITypes.h
@@ -28,11 +28,12 @@
 #include "clang/CodeGen/CGFunctionInfo.h"
 
 namespace llvm {
-  class DataLayout;
-  class Module;
-  class Function;
-  class FunctionType;
-  class Type;
+class Constant;
+class DataLayout;
+class Module;
+class Function;
+class FunctionType;
+class Type;
 }
 
 namespace clang {
@@ -44,6 +45,7 @@
 class DiagnosticsEngine;
 class HeaderSearchOptions;
 class ObjCMethodDecl;
+class ObjCProtocolDecl;
 class PreprocessorOptions;
 
 namespace CodeGen {
@@ -137,6 +139,13 @@
                                                CharUnits DstAlignment,
                                                bool IsVolatile, QualType QT);
 
+/// Get a pointer to a protocol object for the given declaration, emitting it if
+/// it hasn't already been emitted in this translation unit. Note that the ABI
+/// for emitting a protocol reference in code (e.g. for a protocol expression)
+/// in most runtimes is not as simple as just materializing a pointer to this
+/// object.
+llvm::Constant *emitObjCProtocolObject(CodeGenModule &CGM,
+                                       const ObjCProtocolDecl *p);
 }  // end namespace CodeGen
 }  // end namespace clang
 
diff --git a/clang/lib/CodeGen/CGObjCGNU.cpp b/clang/lib/CodeGen/CGObjCGNU.cpp
--- a/clang/lib/CodeGen/CGObjCGNU.cpp
+++ b/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -617,6 +617,11 @@
   llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
                                    const ObjCProtocolDecl *PD) override;
   void GenerateProtocol(const ObjCProtocolDecl *PD) override;
+
+  llvm::Constant *GetOrEmitProtocol(const ObjCProtocolDecl *PD) override {
+    llvm_unreachable("not implemented");
+  }
+
   llvm::Function *ModuleInitFunction() override;
   llvm::FunctionCallee GetPropertyGetFunction() override;
   llvm::FunctionCallee GetPropertySetFunction() override;
diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -1107,11 +1107,6 @@
 
   void GenerateProtocol(const ObjCProtocolDecl *PD) override;
 
-  /// GetOrEmitProtocol - Get the protocol object for the given
-  /// declaration, emitting it if necessary. The return value has type
-  /// ProtocolPtrTy.
-  virtual llvm::Constant *GetOrEmitProtocol(const ObjCProtocolDecl *PD)=0;
-
   /// GetOrEmitProtocolRef - Get a forward reference to the protocol
   /// object for the given declaration, emitting it if needed. These
   /// forward references will be filled in with empty bodies if no
diff --git a/clang/lib/CodeGen/CGObjCRuntime.h b/clang/lib/CodeGen/CGObjCRuntime.h
--- a/clang/lib/CodeGen/CGObjCRuntime.h
+++ b/clang/lib/CodeGen/CGObjCRuntime.h
@@ -211,6 +211,11 @@
   /// implementations.
   virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0;
 
+  /// GetOrEmitProtocol - Get the protocol object for the given
+  /// declaration, emitting it if necessary. The return value has type
+  /// ProtocolPtrTy.
+  virtual llvm::Constant *GetOrEmitProtocol(const ObjCProtocolDecl *PD) = 0;
+
   /// Generate a function preamble for a method with the specified
   /// types.
 
diff --git a/clang/lib/CodeGen/CGObjCRuntime.cpp b/clang/lib/CodeGen/CGObjCRuntime.cpp
--- a/clang/lib/CodeGen/CGObjCRuntime.cpp
+++ b/clang/lib/CodeGen/CGObjCRuntime.cpp
@@ -13,14 +13,15 @@
 //===----------------------------------------------------------------------===//
 
 #include "CGObjCRuntime.h"
-#include "CGCleanup.h"
 #include "CGCXXABI.h"
+#include "CGCleanup.h"
 #include "CGRecordLayout.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/AST/StmtObjC.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
+#include "clang/CodeGen/CodeGenABITypes.h"
 #include "llvm/Support/SaveAndRestore.h"
 
 using namespace clang;
@@ -383,3 +384,9 @@
     CGM.getTypes().GetFunctionType(argsInfo)->getPointerTo();
   return MessageSendInfo(argsInfo, signatureType);
 }
+
+llvm::Constant *
+clang::CodeGen::emitObjCProtocolObject(CodeGenModule &CGM,
+                                       const ObjCProtocolDecl *protocol) {
+  return CGM.getObjCRuntime().GetOrEmitProtocol(protocol);
+}