diff --git a/clang/include/clang/Sema/Overload.h b/clang/include/clang/Sema/Overload.h
--- a/clang/include/clang/Sema/Overload.h
+++ b/clang/include/clang/Sema/Overload.h
@@ -821,7 +821,7 @@
     CallExpr::ADLCallKind IsADLCandidate : 1;
 
     /// Whether this is a rewritten candidate, and if so, of what kind?
-    OverloadCandidateRewriteKind RewriteKind : 2;
+    unsigned RewriteKind : 2;
 
     /// FailureKind - The reason why this candidate is not viable.
     /// Actually an OverloadFailureKind.
@@ -841,6 +841,12 @@
       StandardConversionSequence FinalConversion;
     };
 
+    /// Get RewriteKind value in OverloadCandidateRewriteKind type (This
+    /// function is to workaround the spurious GCC bitfield enum warning)
+    OverloadCandidateRewriteKind getRewriteKind() const {
+      return static_cast<OverloadCandidateRewriteKind>(RewriteKind);
+    }
+
     /// hasAmbiguousConversion - Returns whether this overload
     /// candidate requires an ambiguous conversion or not.
     bool hasAmbiguousConversion() const {
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -9935,7 +9935,7 @@
 
   std::string FnDesc;
   std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
-      ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, Cand->RewriteKind,
+      ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, Cand->getRewriteKind(),
                                 FnDesc);
 
   Expr *FromExpr = Conv.Bad.FromExpr;
@@ -10505,8 +10505,8 @@
 
   std::string FnDesc;
   std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
-      ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee, Cand->RewriteKind,
-                                FnDesc);
+      ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee,
+                                Cand->getRewriteKind(), FnDesc);
 
   S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
       << (unsigned)FnKindPair.first << (unsigned)ocs_non_template
@@ -10624,8 +10624,8 @@
     if (Fn->isDeleted()) {
       std::string FnDesc;
       std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
-          ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, Cand->RewriteKind,
-                                    FnDesc);
+          ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn,
+                                    Cand->getRewriteKind(), FnDesc);
 
       S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
           << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
@@ -10635,7 +10635,7 @@
     }
 
     // We don't really have anything else to say about viable candidates.
-    S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->RewriteKind);
+    S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
     return;
   }
 
@@ -10668,7 +10668,7 @@
   case ovl_fail_trivial_conversion:
   case ovl_fail_bad_final_conversion:
   case ovl_fail_final_conversion_not_exact:
-    return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->RewriteKind);
+    return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
 
   case ovl_fail_bad_conversion: {
     unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
@@ -10679,7 +10679,7 @@
     // FIXME: this currently happens when we're called from SemaInit
     // when user-conversion overload fails.  Figure out how to handle
     // those conditions and diagnose them well.
-    return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->RewriteKind);
+    return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
   }
 
   case ovl_fail_bad_target: