xref: /llvm-project/clang/test/CXX/dcl.dcl/basic.namespace/namespace.def/namespace.memdef/p3.cpp (revision 0f1c1be1968076d6f96f8a7bcc4a15cf195ecd97)
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 { };
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 { };
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.
f(T)81     template <class T> void f(T) {
82       A::foo(); // expected-error {{'foo' is a private member of 'test5::ns::A'}}
83     }
84   }
85 
f(T)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 {
test()103       void test() {
104         B::foo();
105       }
106     };
107   }
108 
109   class A {
test()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 {
test()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 {
test()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 {
test()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 {
test()188     void test() {
189       ns2::B::foo();
190     }
191   };
192 }
193