xref: /llvm-project/clang/test/SemaCXX/undefined-internal.cpp (revision e5945871cfb954d80cbeb9c99a26f02b41decae6)
1 // RUN: %clang_cc1 -fsyntax-only -verify -Wbind-to-temporary-copy %s
2 // RUN: %clang_cc1 -fsyntax-only -verify -Wbind-to-temporary-copy -std=c++98 %s
3 // RUN: %clang_cc1 -fsyntax-only -verify -Wbind-to-temporary-copy -std=c++11 %s
4 
5 // Make sure we don't produce invalid IR.
6 // RUN: %clang_cc1 -emit-llvm-only %s
7 // RUN: %clang_cc1 -emit-llvm-only -std=c++98 %s
8 // RUN: %clang_cc1 -emit-llvm-only -std=c++11 %s
9 
10 namespace test1 {
11   static void foo(); // expected-warning {{function 'test1::foo' has internal linkage but is not defined}}
12   template <class T> static void bar(); // expected-warning {{function 'test1::bar<int>' has internal linkage but is not defined}}
13 
14   void test() {
15     foo(); // expected-note {{used here}}
16     bar<int>(); // expected-note {{used here}}
17   }
18 }
19 
20 namespace test2 {
21   namespace {
22     void foo(); // expected-warning {{function 'test2::(anonymous namespace)::foo' has internal linkage but is not defined}}
23     extern int var; // expected-warning {{variable 'test2::(anonymous namespace)::var' has internal linkage but is not defined}}
24     template <class T> void bar(); // expected-warning {{function 'test2::(anonymous namespace)::bar<int>' has internal linkage but is not defined}}
25   }
26   void test() {
27     foo(); // expected-note {{used here}}
28     var = 0; // expected-note {{used here}}
29     bar<int>(); // expected-note {{used here}}
30   }
31 }
32 
33 namespace test3 {
34   namespace {
35     void foo();
36     extern int var;
37     template <class T> void bar();
38   }
39 
40   void test() {
41     foo();
42     var = 0;
43     bar<int>();
44   }
45 
46   namespace {
47     void foo() {}
48     int var = 0;
49     template <class T> void bar() {}
50   }
51 }
52 
53 namespace test4 {
54   namespace {
55     struct A {
56       A(); // expected-warning {{function 'test4::(anonymous namespace)::A::A' has internal linkage but is not defined}}
57       ~A();// expected-warning {{function 'test4::(anonymous namespace)::A::~A' has internal linkage but is not defined}}
58       virtual void foo(); // expected-warning {{function 'test4::(anonymous namespace)::A::foo' has internal linkage but is not defined}}
59       virtual void bar() = 0;
60       virtual void baz(); // expected-warning {{function 'test4::(anonymous namespace)::A::baz' has internal linkage but is not defined}}
61     };
62   }
63 
64   void test(A &a) {
65     a.foo(); // expected-note {{used here}}
66     a.bar();
67     a.baz(); // expected-note {{used here}}
68   }
69 
70   struct Test : A {
71     Test() {} // expected-note 2 {{used here}}
72   };
73 }
74 
75 // rdar://problem/9014651
76 namespace test5 {
77   namespace {
78     struct A {};
79   }
80 
81   template <class N> struct B {
82     static int var; // expected-warning {{variable 'test5::B<test5::(anonymous namespace)::A>::var' has internal linkage but is not defined}}
83     static void foo(); // expected-warning {{function 'test5::B<test5::(anonymous namespace)::A>::foo' has internal linkage but is not defined}}
84   };
85   extern template int B<A>::var;
86 
87   void test() {
88     B<A>::var = 0; // expected-note {{used here}}
89     B<A>::foo(); // expected-note {{used here}}
90   }
91 }
92 
93 namespace test6 {
94   template <class T> struct A {
95     static const int zero = 0;
96     static const int one = 1;
97     static const int two = 2;
98 
99     int value;
100 
101     A() : value(zero) {
102       value = one;
103     }
104   };
105 
106   namespace { struct Internal; }
107 
108   void test() {
109     A<Internal> a;
110     a.value = A<Internal>::two;
111   }
112 }
113 
114 // We support (as an extension) private, undefined copy constructors when
115 // a temporary is bound to a reference even in C++98. Similarly, we shouldn't
116 // warn about this copy constructor being used without a definition.
117 namespace PR9323 {
118   namespace {
119     struct Uncopyable {
120       Uncopyable() {}
121     private:
122       Uncopyable(const Uncopyable&); // expected-note {{declared private here}}
123     };
124   }
125   void f(const Uncopyable&) {}
126   void test() {
127     f(Uncopyable());
128 #if __cplusplus <= 199711L // C++03 or earlier modes
129     // expected-warning@-2 {{C++98 requires an accessible copy constructor}}
130 #else
131     // expected-warning@-4 {{copying parameter of type 'PR9323::(anonymous namespace)::Uncopyable' when binding a reference to a temporary would invoke an inaccessible constructor in C++98}}
132 #endif
133   };
134 }
135 
136 
137 namespace std { class type_info; };
138 namespace cxx11_odr_rules {
139   // Note: the way this test is written isn't really ideal, but there really
140   // isn't any other way to check that the odr-used logic for constants
141   // is working without working implicit capture in lambda-expressions.
142   // (The more accurate used-but-not-defined warning is the only other visible
143   // effect of accurate odr-used computation.)
144   //
145   // Note that the warning in question can trigger in cases some people would
146   // consider false positives; hopefully that happens rarely in practice.
147   //
148   // FIXME: Suppressing this test while I figure out how to fix a bug in the
149   // odr-use marking code.
150 
151   namespace {
152     struct A {
153       static const int unused = 10;
154       static const int used1 = 20; // xpected-warning {{internal linkage}}
155       static const int used2 = 20; // xpected-warning {{internal linkage}}
156       virtual ~A() {}
157     };
158   }
159 
160   void a(int,int);
161   A& p(const int&) { static A a; return a; }
162 
163   // Check handling of default arguments
164   void b(int = A::unused);
165 
166   void tests() {
167     // Basic test
168     a(A::unused, A::unused);
169 
170     // Check that nesting an unevaluated or constant-evaluated context does
171     // the right thing.
172     a(A::unused, sizeof(int[10]));
173 
174     // Check that the checks work with unevaluated contexts
175     (void)sizeof(p(A::used1));
176     (void)typeid(p(A::used1)); // expected-warning {{expression with side effects will be evaluated despite being used as an operand to 'typeid'}} xpected-note {{used here}}
177 
178     // Misc other testing
179     a(A::unused, 1 ? A::used2 : A::used2); // xpected-note {{used here}}
180     b();
181   }
182 }
183 
184 
185 namespace OverloadUse {
186   namespace {
187     void f();
188     void f(int); // expected-warning {{function 'OverloadUse::(anonymous namespace)::f' has internal linkage but is not defined}}
189     void f(int, int); // expected-warning {{function 'OverloadUse::(anonymous namespace)::f' has internal linkage but is not defined}}
190   }
191   template<void x()> void t() { x(); }
192   template<void x(int)> void t(int*) { x(10); }
193   template<void x(int, int)> void t(int*, int*) {}
194   void g(int n) {
195     t<f>(&n); // expected-note {{used here}}
196     t<f>(&n, &n); // expected-note {{used here}}
197   }
198 }
199 
200 namespace test7 {
201   typedef struct {
202     void bar();
203     void foo() {
204       bar();
205     }
206   } A;
207 }
208 
209 namespace test8 {
210   typedef struct {
211     void bar(); // expected-warning {{function 'test8::(anonymous struct)::bar' has internal linkage but is not defined}}
212     void foo() {
213       bar(); // expected-note {{used here}}
214     }
215   } *A;
216 }
217 
218 namespace test9 {
219   namespace {
220     struct X {
221       virtual void notused() = 0;
222       virtual void used() = 0; // expected-warning {{function 'test9::(anonymous namespace)::X::used' has internal linkage but is not defined}}
223     };
224   }
225   void test(X &x) {
226     x.notused();
227     x.X::used(); // expected-note {{used here}}
228   }
229 }
230 
231 namespace test10 {
232   namespace {
233     struct X {
234       virtual void notused() = 0;
235       virtual void used() = 0; // expected-warning {{function 'test10::(anonymous namespace)::X::used' has internal linkage but is not defined}}
236 
237       void test() {
238         notused();
239         (void)&X::notused;
240         (this->*&X::notused)();
241         X::used();  // expected-note {{used here}}
242       }
243     };
244     struct Y : X {
245       using X::notused;
246     };
247   }
248 }
249 
250 namespace test11 {
251   namespace {
252     struct A {
253       virtual bool operator()() const = 0;
254       virtual void operator!() const = 0;
255       virtual bool operator+(const A&) const = 0;
256       virtual int operator[](int) const = 0;
257       virtual const A* operator->() const = 0;
258       int member;
259     };
260 
261     struct B {
262       bool operator()() const;  // expected-warning {{function 'test11::(anonymous namespace)::B::operator()' has internal linkage but is not defined}}
263       void operator!() const;  // expected-warning {{function 'test11::(anonymous namespace)::B::operator!' has internal linkage but is not defined}}
264       bool operator+(const B&) const;  // expected-warning {{function 'test11::(anonymous namespace)::B::operator+' has internal linkage but is not defined}}
265       int operator[](int) const;  // expected-warning {{function 'test11::(anonymous namespace)::B::operator[]' has internal linkage but is not defined}}
266       const B* operator->() const;  // expected-warning {{function 'test11::(anonymous namespace)::B::operator->' has internal linkage but is not defined}}
267       int member;
268     };
269   }
270 
271   void test1(A &a1, A &a2) {
272     a1();
273     !a1;
274     a1 + a2;
275     a1[0];
276     (void)a1->member;
277   }
278 
279   void test2(B &b1, B &b2) {
280     b1();  // expected-note {{used here}}
281     !b1;  // expected-note {{used here}}
282     b1 + b2;  // expected-note {{used here}}
283     b1[0];  // expected-note {{used here}}
284     (void)b1->member;  // expected-note {{used here}}
285   }
286 }
287 
288 namespace test12 {
289   class T1 {}; class T2 {}; class T3 {}; class T4 {}; class T5 {}; class T6 {};
290   class T7 {};
291 
292   namespace {
293     struct Cls {
294       virtual void f(int) = 0;
295       virtual void f(int, double) = 0;
296       void g(int);  // expected-warning {{function 'test12::(anonymous namespace)::Cls::g' has internal linkage but is not defined}}
297       void g(int, double);
298       virtual operator T1() = 0;
299       virtual operator T2() = 0;
300       virtual operator T3&() = 0;
301       operator T4();  // expected-warning {{function 'test12::(anonymous namespace)::Cls::operator T4' has internal linkage but is not defined}}
302       operator T5();  // expected-warning {{function 'test12::(anonymous namespace)::Cls::operator T5' has internal linkage but is not defined}}
303       operator T6&();  // expected-warning {{function 'test12::(anonymous namespace)::Cls::operator test12::T6 &' has internal linkage but is not defined}}
304     };
305 
306     struct Cls2 {
307       Cls2(T7);  // expected-warning {{function 'test12::(anonymous namespace)::Cls2::Cls2' has internal linkage but is not defined}}
308     };
309   }
310 
311   void test(Cls &c) {
312     c.f(7);
313     c.g(7);  // expected-note {{used here}}
314     (void)static_cast<T1>(c);
315     T2 t2 = c;
316     T3 &t3 = c;
317     (void)static_cast<T4>(c); // expected-note {{used here}}
318     T5 t5 = c;  // expected-note {{used here}}
319     T6 &t6 = c;  // expected-note {{used here}}
320 
321     Cls2 obj1((T7()));  // expected-note {{used here}}
322   }
323 }
324 
325 namespace test13 {
326   namespace {
327     struct X {
328       virtual void f() { }
329     };
330 
331     struct Y : public X {
332       virtual void f() = 0;
333 
334       virtual void g() {
335         X::f();
336       }
337     };
338   }
339 }
340 
341 namespace test14 {
342   extern "C" const int foo;
343 
344   int f() {
345     return foo;
346   }
347 }
348