diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index df0ea77..824fd4d 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -1518,10 +1518,16 @@
   // FIXME: Since method decls contain the selector, and most messages have a
   // prototype, consider devising a scheme for unifying SelName/MethodProto.
   ObjCMethodDecl *MethodProto;
-  
-  IdentifierInfo *ClassName; // optional - 0 for instance messages.
-  
+
   SourceLocation LBracloc, RBracloc;
+  
+  // constructor used during deserialization
+  ObjCMessageExpr(Selector selInfo, QualType retType,
+                  SourceLocation LBrac, SourceLocation RBrac,
+                  Expr **ArgExprs, unsigned nargs)
+  : Expr(ObjCMessageExprClass, retType), NumArgs(nargs), SelName(selInfo),
+    MethodProto(NULL), LBracloc(LBrac), RBracloc(RBrac) {}
+  
 public:
   // constructor for class messages. 
   // FIXME: clsName should be typed to ObjCInterfaceType
@@ -1534,6 +1540,7 @@
                   QualType retType, ObjCMethodDecl *methDecl,
                   SourceLocation LBrac, SourceLocation RBrac,
                   Expr **ArgExprs, unsigned NumArgs);
+  
   ~ObjCMessageExpr() {
     delete [] SubExprs;
   }
@@ -1541,8 +1548,13 @@
   /// getReceiver - Returns the receiver of the message expression.
   ///  This can be NULL if the message is for instance methods.  For
   ///  instance methods, use getClassName.
-  const Expr *getReceiver() const { return SubExprs[RECEIVER]; }
-  Expr *getReceiver() { return SubExprs[RECEIVER]; }
+  Expr *getReceiver() { 
+    uintptr_t x = (uintptr_t) SubExprs[RECEIVER];
+    return x & 0x1 ? NULL : (Expr*) x;
+  }  
+  const Expr *getReceiver() const {
+    return const_cast<ObjCMessageExpr*>(this)->getReceiver();
+  }
   
   Selector getSelector() const { return SelName; }
 
@@ -1551,8 +1563,13 @@
   
   /// getClassName - For instance methods, this returns the invoked class,
   ///  and returns NULL otherwise.  For regular methods, use getReceiver.  
-  const IdentifierInfo *getClassName() const { return ClassName; }
-  IdentifierInfo *getClassName() { return ClassName; }
+  IdentifierInfo *getClassName() {
+    uintptr_t x = (uintptr_t) SubExprs[RECEIVER];
+    return x & 0x1 ? (IdentifierInfo*) (x & ~0x1) : NULL;
+  }  
+  const IdentifierInfo *getClassName() const {
+    return const_cast<ObjCMessageExpr*>(this)->getClassName();
+  }
   
   /// getNumArgs - Return the number of actual arguments to this call.
   unsigned getNumArgs() const { return NumArgs; }
@@ -1591,7 +1608,11 @@
   arg_iterator arg_begin() { return &SubExprs[ARGS_START]; }
   arg_iterator arg_end()   { return arg_begin() + NumArgs; }
   const_arg_iterator arg_begin() const { return &SubExprs[ARGS_START]; }
-  const_arg_iterator arg_end() const { return arg_begin() + NumArgs; }  
+  const_arg_iterator arg_end() const { return arg_begin() + NumArgs; }
+  
+  // Serialization.
+  virtual void EmitImpl(llvm::Serializer& S) const;
+  static ObjCMessageExpr* CreateImpl(llvm::Deserializer& D, ASTContext& C);
 };
 
 }  // end namespace clang
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 67e39b6..479b651 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -1091,7 +1091,7 @@
                 SourceLocation LBrac, SourceLocation RBrac,
                 Expr **ArgExprs, unsigned nargs)
   : Expr(ObjCMessageExprClass, retType), SelName(selInfo), 
-    MethodProto(mproto), ClassName(0) {
+    MethodProto(mproto) {
   NumArgs = nargs;
   SubExprs = new Expr*[NumArgs+1];
   SubExprs[RECEIVER] = receiver;
@@ -1110,10 +1110,10 @@
                 SourceLocation LBrac, SourceLocation RBrac,
                 Expr **ArgExprs, unsigned nargs)
   : Expr(ObjCMessageExprClass, retType), SelName(selInfo), 
-    MethodProto(mproto), ClassName(clsName) {
+    MethodProto(mproto) {
   NumArgs = nargs;
   SubExprs = new Expr*[NumArgs+1];
-  SubExprs[RECEIVER] = 0;
+  SubExprs[RECEIVER] = (Expr*) ((uintptr_t) clsName | 0x1);
   if (NumArgs) {
     for (unsigned i = 0; i != NumArgs; ++i)
       SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
@@ -1122,7 +1122,6 @@
   RBracloc = RBrac;
 }
 
-
 bool ChooseExpr::isConditionTrue(ASTContext &C) const {
   llvm::APSInt CondVal(32);
   bool IsConst = getCond()->isIntegerConstantExpr(CondVal, C);
@@ -1397,8 +1396,8 @@
 }
 
 // ObjCMessageExpr
-Stmt::child_iterator ObjCMessageExpr::child_begin() {
-  return reinterpret_cast<Stmt**>(&SubExprs[0]);
+Stmt::child_iterator ObjCMessageExpr::child_begin() {  
+  return reinterpret_cast<Stmt**>(&SubExprs[ getReceiver() ? 0 : ARGS_START ]);
 }
 Stmt::child_iterator ObjCMessageExpr::child_end() {
   return reinterpret_cast<Stmt**>(&SubExprs[getNumArgs()+ARGS_START]);
diff --git a/lib/AST/StmtDumper.cpp b/lib/AST/StmtDumper.cpp
index 798ea84..77fbad5 100644
--- a/lib/AST/StmtDumper.cpp
+++ b/lib/AST/StmtDumper.cpp
@@ -428,6 +428,8 @@
 void StmtDumper::VisitObjCMessageExpr(ObjCMessageExpr* Node) {
   DumpExpr(Node);
   fprintf(F, " selector=%s", Node->getSelector().getName().c_str());
+  IdentifierInfo* clsName = Node->getClassName();
+  if (clsName) fprintf(F, " class=%s", clsName->getName());
 }
 
 void StmtDumper::VisitObjCEncodeExpr(ObjCEncodeExpr *Node) {
diff --git a/lib/AST/StmtSerialization.cpp b/lib/AST/StmtSerialization.cpp
index 3bec743..adaa559 100644
--- a/lib/AST/StmtSerialization.cpp
+++ b/lib/AST/StmtSerialization.cpp
@@ -181,6 +181,9 @@
     case ObjCIvarRefExprClass:
       return ObjCIvarRefExpr::CreateImpl(D, C);
       
+    case ObjCMessageExprClass:
+      return ObjCMessageExpr::CreateImpl(D, C);
+      
     case ObjCSelectorExprClass:
       return ObjCSelectorExpr::CreateImpl(D, C);
       
@@ -190,9 +193,9 @@
     //==--------------------------------------==//
     //    C++
     //==--------------------------------------==//
-    case CXXDefaultArgExprClass:
-      return CXXDefaultArgExpr::CreateImpl(D, C);
       
+    case CXXDefaultArgExprClass:
+      return CXXDefaultArgExpr::CreateImpl(D, C);      
   }
 }
 
@@ -327,7 +330,7 @@
   S.Emit(getType());
   S.Emit(RParenLoc);
   S.EmitInt(NumArgs);
-  S.BatchEmitOwnedPtrs(NumArgs+1,SubExprs);  
+  S.BatchEmitOwnedPtrs(NumArgs+1, SubExprs);  
 }
 
 CallExpr* CallExpr::CreateImpl(Deserializer& D, ASTContext& C) {
@@ -984,6 +987,58 @@
   return dr;
 }
 
+void ObjCMessageExpr::EmitImpl(Serializer& S) const {
+  S.EmitBool(getReceiver() ? true : false);
+  S.Emit(getType());
+  S.Emit(SelName);
+  S.Emit(LBracloc);
+  S.Emit(RBracloc);
+  S.EmitInt(NumArgs);  
+  S.EmitPtr(MethodProto);
+  
+  if (getReceiver())
+    S.BatchEmitOwnedPtrs(NumArgs+1, SubExprs);
+  else {    
+    S.EmitPtr(getClassName());
+    S.BatchEmitOwnedPtrs(NumArgs, &SubExprs[ARGS_START]);
+  }
+}
+
+ObjCMessageExpr* ObjCMessageExpr::CreateImpl(Deserializer& D, ASTContext& C) {
+  bool isReceiver = D.ReadBool();
+  QualType t = QualType::ReadVal(D);
+  Selector S = Selector::ReadVal(D);
+  SourceLocation L = SourceLocation::ReadVal(D);
+  SourceLocation R = SourceLocation::ReadVal(D);
+    
+  // Construct an array for the subexpressions.
+  unsigned NumArgs = D.ReadInt();
+  Expr** SubExprs = new Expr*[NumArgs+1];
+  
+  // Construct the ObjCMessageExpr object using the special ctor.
+  ObjCMessageExpr* ME = new ObjCMessageExpr(S, t, L, R, SubExprs, NumArgs);
+  
+  // Read in the MethodProto.  Read the instance variable directly
+  // allows it to be backpatched.
+  D.ReadPtr(ME->MethodProto);
+  
+  // Now read in the arguments.
+  
+  if (isReceiver)
+    D.BatchReadOwnedPtrs(NumArgs+1, SubExprs, C);
+  else {
+    // Read the pointer for ClassName.  The Deserializer will handle the
+    // bit-mangling automatically.
+    SubExprs[RECEIVER] = (Expr*) ((uintptr_t) 0x1);
+    D.ReadUIntPtr((uintptr_t&) SubExprs[RECEIVER]);
+    
+    // Read the arguments.
+    D.BatchReadOwnedPtrs(NumArgs, &SubExprs[ARGS_START], C);
+  }
+  
+  return ME;
+}
+
 void ObjCSelectorExpr::EmitImpl(Serializer& S) const {
   S.Emit(AtLoc);
   S.Emit(RParenLoc);