PR40329: [adl] Fix determination of associated classes when searching a

member enum and then its enclosing class.

There are situations where ADL will collect a class but not the complete
set of associated classes / namespaces of that class. When that
happened, and we later tried to collect those associated classes /
namespaces, we would previously short-circuit the lookup and not find
them. Eg, for:

  struct A : B { enum E; };

if we first looked for associated classes/namespaces of A::E, we'd find
only A. But if we then tried to also collect associated
classes/namespaces of A (which should include the base class B), we
would not add B because we had already visited A.

This also fixes a minor issue where we would fail to collect associated
classes from an overloaded class member access expression naming a
static member function.

llvm-svn: 351382

2 files changed, 50 insertions, 0 deletions

diff --git a/clang/test/CXX/drs/dr0xx.cpp b/clang/test/CXX/drs/dr0xx.cpp
index 048187814db..911aab17474 100644
--- a/clang/test/CXX/drs/dr0xx.cpp
+++ b/clang/test/CXX/drs/dr0xx.cpp
@@ -413,6 +413,36 @@ namespace dr33 { // dr33: yes
   void g(X::S);
   template<typename Z> Z g(Y::T);
   void h() { f(&g); } // expected-error {{ambiguous}}
+
+  template<typename T> void t(X::S);
+  template<typename T, typename U = void> void u(X::S); // expected-error 0-1{{default template argument}}
+  void templ() { f(t<int>); f(u<int>); }
+
+  // Even though v<int> cannot select the first overload, ADL considers it
+  // and adds namespace Z to the set of associated namespaces, and then picks
+  // Z::f even though that function has nothing to do with any associated type.
+  namespace Z { struct Q; void f(void(*)()); }
+  template<int> Z::Q v();
+  template<typename> void v();
+  void unrelated_templ() { f(v<int>); }
+
+  namespace dependent {
+    struct X {};
+    template<class T> struct Y {
+      friend int operator+(X, void(*)(Y)) {}
+    };
+
+    template<typename T> void f(Y<T>);
+    int use = X() + f<int>; // expected-error {{invalid operands}}
+  }
+
+  namespace member {
+    struct Q {};
+    struct Y { friend int operator+(Q, Y (*)()); };
+    struct X { template<typename> static Y f(); };
+    int m = Q() + X().f<int>; // ok
+    int n = Q() + (&(X().f<int>)); // ok
+  }
 }
 
 // dr34: na
diff --git a/clang/test/SemaCXX/adl.cpp b/clang/test/SemaCXX/adl.cpp
new file mode 100644
index 00000000000..392ddddcb4e
--- /dev/null
+++ b/clang/test/SemaCXX/adl.cpp
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -std=c++11 -verify %s
+
+namespace PR40329 {
+  struct A {
+    A(int);
+    friend int operator->*(A, A);
+  };
+  struct B : A {
+    B();
+    enum E { e };
+  };
+  // Associated classes for B are {B, A}
+  // Associated classes for B::E are {B} (non-transitive in this case)
+  //
+  // If we search B::E first, we must not mark B "visited" and shortcircuit
+  // visiting it later, or we won't find the associated class A.
+  int k0 = B::e ->* B::e; // expected-error {{non-pointer-to-member type}}
+  int k1 = B::e ->* B();
+  int k2 = B() ->* B::e;
+}