r289055 - [Sema] Avoid "case value not in enumerated type" warning for C++11 opaque enums

[Alex Lorenz via cfe-commits]

Author: arphaman
Date: Thu Dec  8 08:46:05 2016
New Revision: 289055

URL: http://llvm.org/viewvc/llvm-project?rev=289055&view=rev
Log:
[Sema] Avoid "case value not in enumerated type" warning for C++11 opaque enums

This commit ensures that the switch warning "case value not in enumerated type"
isn't shown for opaque enums. We don't know the actual list of values in opaque
enums, so that warning is incorrect.

rdar://29230764

Differential Revision: https://reviews.llvm.org/D27299

Modified:
    cfe/trunk/lib/Sema/SemaStmt.cpp
    cfe/trunk/test/SemaCXX/switch.cpp

Modified: cfe/trunk/lib/Sema/SemaStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=289055&r1=289054&r2=289055&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaStmt.cpp (original)
+++ cfe/trunk/lib/Sema/SemaStmt.cpp Thu Dec  8 08:46:05 2016
@@ -1070,7 +1070,8 @@ Sema::ActOnFinishSwitchStmt(SourceLocati
     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;
 

Modified: cfe/trunk/test/SemaCXX/switch.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/switch.cpp?rev=289055&r1=289054&r2=289055&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/switch.cpp (original)
+++ cfe/trunk/test/SemaCXX/switch.cpp Thu Dec  8 08:46:05 2016
@@ -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;
+  }
+}
+
+}