Look through sugar when determining whether a type is a scoped enumeration

type. Patch by Stephan Bergmann!

llvm-svn: 225889

clang/lib/Sema/SemaExpr.cpp

@@ -7546,7 +7546,7 @@ QualType Sema::CheckSubtractionOperands(ExprResult &LHS, ExprResult &RHS,
 }
 
 static bool isScopedEnumerationType(QualType T) {
-  if (const EnumType *ET = dyn_cast<EnumType>(T))
+  if (const EnumType *ET = T->getAs<EnumType>())
     return ET->getDecl()->isScoped();
   return false;
 }

clang/test/SemaCXX/enum-scoped.cpp

@@ -301,3 +301,11 @@ namespace PR18044 {
   using E::a; // ok!
   E b = a;
 }
+
+namespace test11 {
+  enum class E { a };
+  typedef E E2;
+  E2 f1() { return E::a; }
+
+  bool f() { return !f1(); } // expected-error {{invalid argument type 'E2' (aka 'test11::E') to unary expression}}
+}