1 // RUN: %clang_cc1 -fsyntax-only -triple %itanium_abi_triple -verify %s -std=c++11
2 // RUN: %clang_cc1 -fsyntax-only -triple %ms_abi_triple -verify %s -std=c++11
3 namespace T1 {
4 
5 class A {
6   virtual int f(); // expected-note{{overridden virtual function is here}}
7 };
8 
9 class B : A {
10   virtual void f(); // expected-error{{virtual function 'f' has a different return type ('void') than the function it overrides (which has return type 'int')}}
11 };
12 
13 }
14 
15 namespace T2 {
16 
17 struct a { };
18 struct b { };
19 
20 class A {
21   virtual a* f(); // expected-note{{overridden virtual function is here}}
22 };
23 
24 class B : A {
25   virtual b* f(); // expected-error{{return type of virtual function 'f' is not covariant with the return type of the function it overrides ('T2::b *' is not derived from 'T2::a *')}}
26 };
27 
28 }
29 
30 namespace T3 {
31 
32 struct a { };
33 struct b : private a { }; // expected-note{{declared private here}}
34 
35 class A {
36   virtual a* f(); // FIXME: desired-note{{overridden virtual function is here}}
37 };
38 
39 class B : A {
40   virtual b* f(); // expected-error{{invalid covariant return for virtual function: 'T3::a' is a private base class of 'T3::b'}}
41 };
42 
43 }
44 
45 namespace T4 {
46 
47 struct a { };
48 struct a1 : a { };
49 struct b : a, a1 { }; // expected-warning{{direct base 'T4::a' is inaccessible due to ambiguity:\n    struct T4::b -> struct T4::a\n    struct T4::b -> struct T4::a1 -> struct T4::a}}
50 
51 class A {
52   virtual a* f(); // expected-note{{overridden virtual function is here}}
53 };
54 
55 class B : A {
56   virtual b* f(); // expected-error{{return type of virtual function 'f' is not covariant with the return type of the function it overrides (ambiguous conversion from derived class 'T4::b' to base class 'T4::a':\n\
57     struct T4::b -> struct T4::a\n\
58     struct T4::b -> struct T4::a1 -> struct T4::a)}}
59 };
60 
61 }
62 
63 namespace T5 {
64 
65 struct a { };
66 
67 class A {
68   virtual a* const f();
69   virtual a* const g(); // expected-note{{overridden virtual function is here}}
70 };
71 
72 class B : A {
73   virtual a* const f();
74   virtual a* g(); // expected-error{{return type of virtual function 'g' is not covariant with the return type of the function it overrides ('T5::a *' has different qualifiers than 'T5::a *const')}}
75 };
76 
77 }
78 
79 namespace T6 {
80 
81 struct a { };
82 
83 class A {
84   virtual const a* f();
85   virtual a* g(); // expected-note{{overridden virtual function is here}}
86 };
87 
88 class B : A {
89   virtual a* f();
90   virtual const a* g(); // expected-error{{return type of virtual function 'g' is not covariant with the return type of the function it overrides (class type 'const T6::a *' is more qualified than class type 'T6::a *'}}
91 };
92 
93 }
94 
95 namespace T7 {
96   struct a { };
97   struct b { };
98 
99   class A {
100     a* f();
101   };
102 
103   class B : A {
104     virtual b* f();
105   };
106 }
107 
108 namespace T8 {
109   struct a { };
110   struct b; // expected-note {{forward declaration of 'T8::b'}}
111 
112   class A {
113     virtual a *f();
114   };
115 
116   class B : A {
117     b* f(); // expected-error {{return type of virtual function 'f' is not covariant with the return type of the function it overrides ('T8::b' is incomplete)}}
118   };
119 }
120 
121 namespace T9 {
122   struct a { };
123 
124   template<typename T> struct b : a {
125     int a[sizeof(T) ? -1 : -1]; // expected-error {{array with a negative size}}
126   };
127 
128   class A {
129     virtual a *f();
130   };
131 
132   class B : A {
133     virtual b<int> *f(); // expected-note {{in instantiation of template class 'T9::b<int>' requested here}}
134   };
135 }
136 
137 // PR5656
138 class X0 {
139   virtual void f0();
140 };
141 class X1 : public X0 {
142   void f0() = 0;
143 };
144 
145 template <typename Base>
146 struct Foo : Base {
147   void f(int) = 0; // expected-error{{not virtual and cannot be declared pure}}
148 };
149 
150 struct Base1 { virtual void f(int); };
151 struct Base2 { };
152 
test()153 void test() {
154   (void)sizeof(Foo<Base1>);
155   (void)sizeof(Foo<Base2>); // expected-note{{instantiation}}
156 }
157 
158 template<typename Base>
159 struct Foo2 : Base {
160   template<typename T> int f(T);
161 };
162 
test2()163 void test2() {
164   Foo2<Base1> f1;
165   Foo2<Base2> f2;
166   f1.f(17);
167   f2.f(17);
168 };
169 
170 struct Foo3 {
171   virtual void f(int) = 0; // expected-note{{unimplemented pure virtual method}}
172 };
173 
174 template<typename T>
175 struct Bar3 : Foo3 {
176   void f(T);
177 };
178 
test3()179 void test3() {
180   Bar3<int> b3i; // okay
181   Bar3<float> b3f; // expected-error{{is an abstract class}}
182 }
183 
184 // 5920
185 namespace PR5920 {
186   class Base {};
187 
188   template <typename T>
189   class Derived : public Base {};
190 
191   class Foo {
192    public:
193     virtual Base* Method();
194   };
195 
196   class Bar : public Foo {
197    public:
198     virtual Derived<int>* Method();
199   };
200 }
201 
202 // Look through template types and typedefs to see whether return types are
203 // pointers or references.
204 namespace PR6110 {
205   class Base {};
206   class Derived : public Base {};
207 
208   typedef Base* BaseP;
209   typedef Derived* DerivedP;
210 
211   class X { virtual BaseP f(); };
212   class X1 : public X { virtual DerivedP f(); };
213 
214   template <typename T> class Y { virtual T f(); };
215   template <typename T1, typename T> class Y1 : public Y<T> { virtual T1 f(); };
216   Y1<Derived*, Base*> y;
217 }
218 
219 // Defer checking for covariance if either return type is dependent.
220 namespace type_dependent_covariance {
221   struct B {};
222   template <int N> struct TD : public B {};
223   template <> struct TD<1> {};
224 
225   template <int N> struct TB {};
226   struct D : public TB<0> {};
227 
228   template <int N> struct X {
229     virtual B* f1(); // expected-note{{overridden virtual function is here}}
230     virtual TB<N>* f2(); // expected-note{{overridden virtual function is here}}
231   };
232   template <int N, int M> struct X1 : X<N> {
233     virtual TD<M>* f1(); // expected-error{{return type of virtual function 'f1' is not covariant with the return type of the function it overrides ('TD<1> *'}}
234     virtual D* f2(); // expected-error{{return type of virtual function 'f2' is not covariant with the return type of the function it overrides ('type_dependent_covariance::D *' is not derived from 'TB<1> *')}}
235   };
236 
237   X1<0, 0> good;
238   X1<0, 1> bad_derived; // expected-note{{instantiation}}
239   X1<1, 0> bad_base; // expected-note{{instantiation}}
240 }
241 
242 namespace T10 {
243   struct A { };
244   struct B : A { };
245 
246   struct C {
247     virtual A&& f();
248   };
249 
250   struct D : C {
251     virtual B&& f();
252   };
253 };
254 
255 namespace T11 {
256   struct A { };
257   struct B : A { };
258 
259   struct C {
260     virtual A& f(); // expected-note {{overridden virtual function is here}}
261   };
262 
263   struct D : C {
264     virtual B&& f(); // expected-error {{virtual function 'f' has a different return type ('T11::B &&') than the function it overrides (which has return type 'T11::A &')}}
265   };
266 };
267 
268 namespace T12 {
269   struct A { };
270   struct B : A { };
271 
272   struct C {
273     virtual A&& f(); // expected-note {{overridden virtual function is here}}
274   };
275 
276   struct D : C {
277     virtual B& f(); // expected-error {{virtual function 'f' has a different return type ('T12::B &') than the function it overrides (which has return type 'T12::A &&')}}
278   };
279 };
280 
281 namespace PR8168 {
282   class A {
283   public:
foo()284     virtual void foo() {} // expected-note{{overridden virtual function is here}}
285   };
286 
287   class B : public A {
288   public:
foo()289     static void foo() {} // expected-error{{'static' member function 'foo' overrides a virtual function}}
290   };
291 }
292