Complain when an unnamed enumeration has no enumerations (in

C++). Fixes PR7466.

llvm-svn: 108231

clang/lib/Sema/SemaDecl.cpp

@@ -1539,6 +1539,14 @@ Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
       return DeclPtrTy::make(Tag);
   }
   
+  if (getLangOptions().CPlusPlus && 
+      DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
+    if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Tag))
+      if (Enum->enumerator_begin() == Enum->enumerator_end() &&
+          !Enum->getIdentifier() && !Enum->isInvalidDecl())
+        Diag(Enum->getLocation(), diag::ext_no_declarators)
+          << DS.getSourceRange();
+      
   if (!DS.isMissingDeclaratorOk() &&
       DS.getTypeSpecType() != DeclSpec::TST_error) {
     // Warn about typedefs of enums without names, since this is an

clang/test/Parser/cxx-class.cpp

@@ -7,7 +7,7 @@ protected:
   static int sf(), u;
 
   struct S {};
-  enum {};
+  enum {}; // expected-warning{{declaration does not declare anything}}
   int; // expected-warning {{declaration does not declare anything}}
   int : 1, : 2;
 

clang/test/SemaCXX/enum.cpp

@@ -81,3 +81,7 @@ namespace PR7051 {
     e |= 1; // expected-error{{assigning to 'PR7051::E' from incompatible type 'int'}}
   }
 }
+
+// PR7466
+enum { }; // expected-warning{{declaration does not declare anything}}
+typedef enum { }; // expected-warning{{typedef requires a name}}