Work around a crash when checking access to injected class names

qua templates.  The current fix suppresses the access check entirely
in this case;  to do better, we'd need to be able to say that a
particular lookup result came from a particular injected class name,
which is not easy to do with the current representation of LookupResult.
This is on my known-problems list.

llvm-svn: 111009

clang/lib/Sema/SemaTemplate.cpp

@@ -88,8 +88,13 @@ static void FilterAcceptableTemplateNames(ASTContext &C, LookupResult &R) {
           filter.erase();
           continue;
         }
-          
-      filter.replace(Repl);
+
+      // FIXME: we promote access to public here as a workaround to
+      // the fact that LookupResult doesn't let us remember that we
+      // found this template through a particular injected class name,
+      // which means we end up doing nasty things to the invariants.
+      // Pretending that access is public is *much* safer.
+      filter.replace(Repl, AS_public);
     }
   }
   filter.done();

clang/test/CXX/class.access/p4.cpp

@@ -436,3 +436,17 @@ namespace test17 {
 
   A::Inner<int> s; // expected-error {{'Inner' is a private member of 'test17::A'}}
 }
+
+namespace test18 {
+  template <class T> class A {};
+  class B : A<int> {
+    A<int> member;
+  };
+
+  // FIXME: this access to A should be forbidden (because C++ is dumb),
+  // but LookupResult can't express the necessary information to do
+  // the check, so we aggressively suppress access control.
+  class C : B {
+    A<int> member;
+  };
+}