clang/test/CXX/dcl.dcl/basic.namespace/namespace.def/namespace.memdef/p3.cpp

   1 // RUN: %clang_cc1 -fsyntax-only %s -verify
   2
   3 // C++'0x [namespace.memdef] p3:
   4 //   Every name first declared in a namespace is a member of that namespace. If
   5 //   a friend declaration in a non-local class first declares a class or
   6 //   function the friend class or function is a member of the innermost
   7 //   enclosing namespace.
   8
   9 namespace N {
  10   struct S0 {
  11     friend struct F0;
  12     friend void f0(int);
  13     struct F0 member_func();
  14   };
  15   struct F0 { };
  16   F0 f0() { return S0().member_func(); }
  17 }
  18 N::F0 f0_var = N::f0();
  19
  20 // Ensure we can handle attaching friend declarations to an enclosing namespace
  21 // with multiple contexts.
  22 namespace N { struct S1 { struct IS1; }; }
  23 namespace N {
  24   struct S1::IS1 {
  25     friend struct F1;
  26     friend void f1(int);
  27     struct F1 member_func();
  28   };
  29   struct F1 { };
  30   F1 f1() { return S1::IS1().member_func(); }
  31 }
  32 N::F1 f1_var = N::f1();
  33
  34 //   The name of the friend is not found by unqualified lookup (3.4.1) or by
  35 //   qualified lookup (3.4.3) until a matching declaration is provided in that
  36 //   namespace scope (either before or after the class definition granting
  37 //   friendship). If a friend function is called, its name may be found by the
  38 //   name lookup that considers functions from namespaces and classes
  39 //   associated with the types of the function arguments (3.4.2). If the name
  40 //   in a friend declaration is neither qualified nor a template-id and the
  41 //   declaration is a function or an elaborated-type-specifier, the lookup to
  42 //   determine whether the entity has been previously declared shall not
  43 //   consider any scopes outside the innermost enclosing namespace.
  44
  45 template<typename T> struct X0 { };
  46 struct X1 { };
  47
  48 struct Y {
  49   template<typename T> union X0;
  50   template<typename T> friend union X0;
  51
  52   union X1;
  53   friend union X1;
  54 };
  55
  56 namespace N {
  57   namespace M {
  58     template<typename T> class X;
  59   }
  60 }
  61
  62 namespace N3 {
  63   class Y {
  64     template<typename T> friend class N::M::X;
  65   };
  66 }
  67
  68 // FIXME: Woefully inadequate for testing
  69
  70 // Friends declared as template-ids aren't subject to the restriction
  71 // on innermost namespaces.
  72 namespace test5 {
  73   template <class T> void f(T);
  74   namespace ns {
  75     class A {
  76       friend void f<int>(int);
  77       static void foo(); // expected-note 2 {{declared private here}}
  78     };
  79
  80     // Note that this happens without instantiation.
  81     template <class T> void f(T) {
  82       A::foo(); // expected-error {{'foo' is a private member of 'test5::ns::A'}}
  83     }
  84   }
  85
  86   template <class T> void f(T) {
  87     ns::A::foo(); // expected-error {{'foo' is a private member of 'test5::ns::A'}}
  88   }
  89
  90   template void f<int>(int);
  91   template void f<long>(long); //expected-note {{instantiation}}
  92 }
  93
  94 namespace test6 {
  95   class A;
  96   namespace ns {
  97     class B {
  98       static void foo(); // expected-note {{implicitly declared private here}}
  99       friend union A;
 100     };
 101
 102     union A {
 103       void test() {
 104         B::foo();
 105       }
 106     };
 107   }
 108
 109   class A {
 110     void test() {
 111       ns::B::foo(); // expected-error {{'foo' is a private member of 'test6::ns::B'}}
 112     }
 113   };
 114 }
 115
 116 // We seem to be following a correct interpretation with these, but
 117 // the standard could probably be a bit clearer.
 118 namespace test7a {
 119   namespace ns {
 120     class A;
 121   }
 122
 123   using namespace ns;
 124   class B {
 125     static void foo();
 126     friend class A;
 127   };
 128
 129   class ns::A {
 130     void test() {
 131       B::foo();
 132     }
 133   };
 134 }
 135 namespace test7b {
 136   namespace ns {
 137     class A;
 138   }
 139
 140   using ns::A;
 141   class B {
 142     static void foo();
 143     friend class A;
 144   };
 145
 146   class ns::A {
 147     void test() {
 148       B::foo();
 149     }
 150   };
 151 }
 152 namespace test7c {
 153   namespace ns1 {
 154     class A;
 155   }
 156
 157   namespace ns2 {
 158     // ns1::A appears as if declared in test7c according to [namespace.udir]p2.
 159     // I think that means we aren't supposed to find it.
 160     using namespace ns1;
 161     class B {
 162       static void foo(); // expected-note {{implicitly declared private here}}
 163       friend class A;
 164     };
 165   }
 166
 167   class ns1::A {
 168     void test() {
 169       ns2::B::foo(); // expected-error {{'foo' is a private member of 'test7c::ns2::B'}}
 170     }
 171   };
 172 }
 173 namespace test7d {
 174   namespace ns1 {
 175     class A;
 176   }
 177
 178   namespace ns2 {
 179     // Honor the lexical context of a using-declaration, though.
 180     using ns1::A;
 181     class B {
 182       static void foo();
 183       friend class A;
 184     };
 185   }
 186
 187   class ns1::A {
 188     void test() {
 189       ns2::B::foo();
 190     }
 191   };
 192 }