Recognize GNU attributes after 'enum class'. Fixes the libc++ build.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159089 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Parse/ParseDecl.cpp

@@ -2976,15 +2976,22 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
   SourceLocation ScopedEnumKWLoc;
   bool IsScopedUsingClassTag = false;
 
+  // In C++11, recognize 'enum class' and 'enum struct'.
   if (getLangOpts().CPlusPlus0x &&
       (Tok.is(tok::kw_class) || Tok.is(tok::kw_struct))) {
     Diag(Tok, diag::warn_cxx98_compat_scoped_enum);
     IsScopedUsingClassTag = Tok.is(tok::kw_class);
     ScopedEnumKWLoc = ConsumeToken();
     
+    // Attributes are not allowed between these keywords.  Diagnose,
+    // but then just treat them like they appeared in the right place.
     ProhibitAttributes(attrs);
-    // Recovery: assume that the attributes came after the tag.
+
+    // They are allowed afterwards, though.
+    MaybeParseGNUAttributes(attrs);
     MaybeParseCXX0XAttributes(attrs);
+    while (Tok.is(tok::kw___declspec))
+      ParseMicrosoftDeclSpec(attrs);
   }
 
   // C++11 [temp.explicit]p12:

test/Parser/cxx0x-attributes.cpp

@@ -207,3 +207,8 @@ void baz () {
   for ([[]] int n : { 1, 2, 3 }) {
   }
 }
+
+enum class __attribute__((visibility("hidden"))) SecretKeepers {
+  one, /* rest are deprecated */ two, three
+};
+enum class [[]] EvenMoreSecrets {};