2 files changed, 32 insertions, 1 deletions
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 89c82c9805a..50f0a22ff02 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -1070,7 +1070,8 @@ Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
     const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>();
 
     // If switch has default case, then ignore it.
-    if (!CaseListIsErroneous  && !HasConstantCond && ET) {
+    if (!CaseListIsErroneous && !HasConstantCond && ET &&
+        ET->getDecl()->isCompleteDefinition()) {
       const EnumDecl *ED = ET->getDecl();
       EnumValsTy EnumVals;
 
diff --git a/clang/test/SemaCXX/switch.cpp b/clang/test/SemaCXX/switch.cpp
index 392dcd86980..0c60ce02097 100644
--- a/clang/test/SemaCXX/switch.cpp
+++ b/clang/test/SemaCXX/switch.cpp
@@ -100,3 +100,33 @@ namespace Conversion {
   }
   template void f(S); // expected-note {{instantiation of}}
 }
+
+// rdar://29230764
+namespace OpaqueEnumWarnings {
+
+enum Opaque : int;
+enum class OpaqueClass : int;
+
+enum class Defined : int;
+enum class Defined : int { a };
+
+void test(Opaque o, OpaqueClass oc, Defined d) {
+  // Don't warn that case value is not present in opaque enums.
+  switch (o) {
+  case (Opaque)1:
+    break;
+  }
+  switch (oc) {
+  case (OpaqueClass)1:
+    break;
+  }
+
+  switch (d) {
+  case Defined::a:
+    break;
+  case (Defined)2: // expected-warning {{case value not in enumerated type 'OpaqueEnumWarnings::Defined'}}
+    break;
+  }
+}
+
+}