Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td
+++ include/clang/Basic/DiagnosticGroups.td
@@ -457,7 +457,6 @@
 def : DiagGroup<"sign-promo">;
 def SignCompare : DiagGroup<"sign-compare">;
 def : DiagGroup<"stack-protector">;
-def : DiagGroup<"switch-default">;
 def : DiagGroup<"synth">;
 def SizeofArrayArgument : DiagGroup<"sizeof-array-argument">;
 def SizeofArrayDecay : DiagGroup<"sizeof-array-decay">;
@@ -536,6 +535,7 @@
 def ObjCCStringFormat : DiagGroup<"cstring-format-directive">;
 def CoveredSwitchDefault : DiagGroup<"covered-switch-default">;
 def SwitchBool     : DiagGroup<"switch-bool">;
+def SwitchDefault  : DiagGroup<"switch-default">;
 def SwitchEnum     : DiagGroup<"switch-enum">;
 def Switch         : DiagGroup<"switch">;
 def EnumCompareSwitch : DiagGroup<"enum-compare-switch">;
Index: include/clang/Basic/DiagnosticIDs.h
===================================================================
--- include/clang/Basic/DiagnosticIDs.h
+++ include/clang/Basic/DiagnosticIDs.h
@@ -36,7 +36,7 @@
       DIAG_SIZE_AST           =  150,
       DIAG_SIZE_COMMENT       =  100,
       DIAG_SIZE_CROSSTU       =  100,
-      DIAG_SIZE_SEMA          = 3500,
+      DIAG_SIZE_SEMA          = 3600,
       DIAG_SIZE_ANALYSIS      =  100,
       DIAG_SIZE_REFACTORING   = 1000,
     };
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -8175,6 +8175,9 @@
 def warn_unreachable_default : Warning<
   "default label in switch which covers all enumeration values">,
   InGroup<CoveredSwitchDefault>, DefaultIgnore;
+def warn_missing_default_label : Warning<
+  "missing default label in switch">,
+  InGroup<SwitchDefault>, DefaultIgnore;
 def warn_not_in_enum : Warning<"case value not in enumerated type %0">,
   InGroup<Switch>;
 def warn_not_in_enum_assignment : Warning<"integer constant not in range "
Index: lib/Sema/SemaStmt.cpp
===================================================================
--- lib/Sema/SemaStmt.cpp
+++ lib/Sema/SemaStmt.cpp
@@ -920,6 +920,9 @@
     }
   }
 
+  if (!TheDefaultStmt)
+    Diag(SS->getSwitchLoc(), diag::warn_missing_default_label);
+
   if (!HasDependentValue) {
     // If we don't have a default statement, check whether the
     // condition is constant.
Index: test/Sema/switch-default.c
===================================================================
--- test/Sema/switch-default.c
+++ test/Sema/switch-default.c
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wswitch-default %s
+
+enum E { case1, case2 };
+
+void warn(int x, enum E e) {
+  switch (x) { // expected-warning {{missing default label in switch}}
+  case 0:
+    break;
+  }
+
+  switch (e) { // expected-warning {{missing default label in switch}}
+  case case1:
+    break;
+  case case2:
+    break;
+  }
+}
+
+void no_warn(int x, enum E e) {
+  switch (x) {
+  case 0:
+    break;
+  default:
+    break;
+  }
+
+  switch (e) {
+  case case1:
+    break;
+  case case2:
+    break;
+  default:
+    break;
+  }
+}
Index: test/SemaCXX/switch-default.cpp
===================================================================
--- test/SemaCXX/switch-default.cpp
+++ test/SemaCXX/switch-default.cpp
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wswitch-default %s
+
+enum E { case1, case2 };
+
+void warn(int x, enum E e) {
+  switch (x) { // expected-warning {{missing default label in switch}}
+  case 0:
+    break;
+  }
+
+  switch (e) { // expected-warning {{missing default label in switch}}
+  case case1:
+    break;
+  case case2:
+    break;
+  }
+}
+
+void no_warn(int x, enum E e) {
+  switch (x) {
+  case 0:
+    break;
+  default:
+    break;
+  }
+
+  switch (e) {
+  case case1:
+    break;
+  case case2:
+    break;
+  default:
+    break;
+  }
+}