diff --git a/lib/Sema/SemaCast.cpp b/lib/Sema/SemaCast.cpp
index d6c378e..eb11a57 100644
--- a/lib/Sema/SemaCast.cpp
+++ b/lib/Sema/SemaCast.cpp
@@ -1452,7 +1452,7 @@
   DestType = Self.Context.getCanonicalType(DestType);
   QualType SrcType = SrcExpr->getType();
   if (const ReferenceType *DestTypeTmp =DestType->getAs<ReferenceType>()) {
-    if (DestTypeTmp->isLValueReferenceType() && !SrcExpr->isLValue()) {
+    if (isa<LValueReferenceType>(DestTypeTmp) && !SrcExpr->isLValue()) {
       // Cannot const_cast non-lvalue to lvalue reference type. But if this
       // is C-style, static_cast might find a way, so we simply suggest a
       // message and tell the parent to keep searching.
@@ -1460,6 +1460,16 @@
       return TC_NotApplicable;
     }
 
+    // It's not completely clear under the standard whether we can
+    // const_cast bit-field gl-values.  Doing so would not be
+    // intrinsically complicated, but for now, we say no for
+    // consistency with other compilers and await the word of the
+    // committee.
+    if (SrcExpr->refersToBitField()) {
+      msg = diag::err_bad_cxx_cast_bitfield;
+      return TC_NotApplicable;
+    }
+
     // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
     //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
     DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index e14635e..a0998a4 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -4311,7 +4311,7 @@
     IntRange::forValueOfType(C, E->getType());
   }
 
-  if (FieldDecl *BitField = E->getBitField())
+  if (FieldDecl *BitField = E->getSourceBitField())
     return IntRange(BitField->getBitWidthValue(C),
                     BitField->getType()->isUnsignedIntegerOrEnumerationType());
 
@@ -4688,7 +4688,7 @@
 
   // We want to recurse on the RHS as normal unless we're assigning to
   // a bitfield.
-  if (FieldDecl *Bitfield = E->getLHS()->getBitField()) {
+  if (FieldDecl *Bitfield = E->getLHS()->getSourceBitField()) {
     if (AnalyzeBitFieldAssignment(S, Bitfield, E->getRHS(),
                                   E->getOperatorLoc())) {
       // Recurse, ignoring any implicit conversions on the RHS.
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 0c10658..dd05b82 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -3383,7 +3383,7 @@
     isInvalid = CheckAlignOfExpr(*this, E);
   } else if (ExprKind == UETT_VecStep) {
     isInvalid = CheckVecStepExpr(E);
-  } else if (E->getBitField()) {  // C99 6.5.3.4p1.
+  } else if (E->refersToBitField()) {  // C99 6.5.3.4p1.
     Diag(E->getExprLoc(), diag::err_sizeof_alignof_bitfield) << 0;
     isInvalid = true;
   } else {
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index de93adb..9e8936e 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -3440,7 +3440,7 @@
                                          Qualifiers T1Quals,
                                          Qualifiers T2Quals,
                                          bool IsLValueRef) {
-  bool IsNonAddressableType = Initializer->getBitField() ||
+  bool IsNonAddressableType = Initializer->refersToBitField() ||
                               Initializer->refersToVectorElement();
 
   if (IsNonAddressableType) {
@@ -5225,13 +5225,18 @@
     }
 
     case SK_BindReference:
-      if (FieldDecl *BitField = CurInit.get()->getBitField()) {
-        // References cannot bind to bit fields (C++ [dcl.init.ref]p5).
+      // References cannot bind to bit-fields (C++ [dcl.init.ref]p5).
+      if (CurInit.get()->refersToBitField()) {
+        // We don't necessarily have an unambiguous source bit-field.
+        FieldDecl *BitField = CurInit.get()->getSourceBitField();
         S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
           << Entity.getType().isVolatileQualified()
-          << BitField->getDeclName()
+          << (BitField ? BitField->getDeclName() : DeclarationName())
+          << (BitField != NULL)
           << CurInit.get()->getSourceRange();
-        S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
+        if (BitField)
+          S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
+
         return ExprError();
       }
 
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index c11a075..529ba12 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -1837,7 +1837,7 @@
   // conversion.
   using llvm::APSInt;
   if (From)
-    if (FieldDecl *MemberDecl = From->getBitField()) {
+    if (FieldDecl *MemberDecl = From->getSourceBitField()) {
       APSInt BitWidth;
       if (FromType->isIntegralType(Context) &&
           MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {