Fix handling of redeclaration lookup for using declarations, where the prior

declaration is not visible. Previously we didn't find hidden friend names in
this redeclaration lookup, because we forgot to treat it as a redeclaration
lookup. Conversely, we did find some local extern names, but those don't
actually conflict with a namespace-scope using declaration, because the only
conflicts we can get are scope conflicts, not conflicts due to the entities
being members of the same namespace.

llvm-svn: 206011

1 files changed, 34 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/using-decl-1.cpp b/clang/test/SemaCXX/using-decl-1.cpp
index 24d92f175c3..21aa107e219 100644
--- a/clang/test/SemaCXX/using-decl-1.cpp
+++ b/clang/test/SemaCXX/using-decl-1.cpp
@@ -160,3 +160,37 @@ namespace M { }
 }
 using N::M::FFF; // expected-error {{no member named 'FFF' in namespace 'using_suggestion_val_dropped_nested_specifier::N::M'; did you mean 'N::FFF'?}}
 }
+
+namespace UsingDeclVsHiddenName {
+  namespace A {
+    enum HiddenTag1 {}; // expected-note {{previous use is here}}
+    enum HiddenTag2 {}; // expected-note {{target}}
+    int HiddenFn1; // expected-note {{target}}
+    int HiddenFn2; // expected-note {{target}}
+    int HiddenLocalExtern1;
+    int HiddenLocalExtern2;
+  }
+
+  namespace B {
+    using A::HiddenTag1;
+    using A::HiddenFn1; // expected-note {{using declaration}}
+    using A::HiddenLocalExtern1;
+
+    struct S {
+      friend struct HiddenTag1; // expected-error {{tag type that does not match previous}}
+      friend struct HiddenTag2; // expected-note {{conflicting declaration}}
+      friend void HiddenFn1(); // expected-error {{cannot befriend target of using declaration}}
+      friend void HiddenFn2(); // expected-note {{conflicting declaration}}
+      void f() {
+        // OK, these are not in the scope of namespace B, even though they're
+        // members of the namespace.
+        void HiddenLocalExtern1();
+        void HiddenLocalExtern2();
+      }
+    };
+
+    using A::HiddenTag2; // expected-error {{conflicts with declaration already in scope}}
+    using A::HiddenFn2; // expected-error {{conflicts with declaration already in scope}}
+    using A::HiddenLocalExtern2;
+  }
+}