1// RUN: %clang_cc1 -std=c++98 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
2// RUN: %clang_cc1 -std=c++11 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
3// RUN: %clang_cc1 -std=c++1y %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
4
5#if __cplusplus < 201103L
6// expected-no-diagnostics
7#endif
8
9namespace dr1460 { // dr1460: 3.5
10#if __cplusplus >= 201103L
11  namespace DRExample {
12    union A {
13      union {};
14      union {};
15      constexpr A() {}
16    };
17    constexpr A a = A();
18
19    union B {
20      union {};
21      union {};
22      constexpr B() = default;
23    };
24    constexpr B b = B();
25
26    union C {
27      union {};
28      union {};
29    };
30    constexpr C c = C();
31#if __cplusplus > 201103L
32    constexpr void f() { C c; }
33    static_assert((f(), true), "");
34#endif
35  }
36
37  union A {};
38  union B { int n; }; // expected-note +{{here}}
39  union C { int n = 0; };
40  struct D { union {}; };
41  struct E { union { int n; }; }; // expected-note +{{here}}
42  struct F { union { int n = 0; }; };
43
44  struct X {
45    friend constexpr A::A() noexcept;
46    friend constexpr B::B() noexcept; // expected-error {{follows non-constexpr declaration}}
47    friend constexpr C::C() noexcept;
48    friend constexpr D::D() noexcept;
49    friend constexpr E::E() noexcept; // expected-error {{follows non-constexpr declaration}}
50    friend constexpr F::F() noexcept;
51  };
52
53  // These are OK, because value-initialization doesn't actually invoke the
54  // constructor.
55  constexpr A a = A();
56  constexpr B b = B();
57  constexpr C c = C();
58  constexpr D d = D();
59  constexpr E e = E();
60  constexpr F f = F();
61
62  namespace Defaulted {
63    union A { constexpr A() = default; };
64    union B { int n; constexpr B() = default; }; // expected-error {{not constexpr}}
65    union C { int n = 0; constexpr C() = default; };
66    struct D { union {}; constexpr D() = default; };
67    struct E { union { int n; }; constexpr E() = default; }; // expected-error {{not constexpr}}
68    struct F { union { int n = 0; }; constexpr F() = default; };
69
70    struct G { union { int n = 0; }; union { int m; }; constexpr G() = default; }; // expected-error {{not constexpr}}
71    struct H {
72      union {
73        int n = 0;
74      };
75      union { // expected-note 2{{member not initialized}}
76        int m;
77      };
78      constexpr H() {} // expected-error {{must initialize all members}}
79      constexpr H(bool) : m(1) {}
80      constexpr H(char) : n(1) {} // expected-error {{must initialize all members}}
81      constexpr H(double) : m(1), n(1) {}
82    };
83  }
84
85#if __cplusplus > 201103L
86  template<typename T> constexpr bool check() {
87    T t; // expected-note-re 2{{non-constexpr constructor '{{[BE]}}'}}
88    return true;
89  }
90  static_assert(check<A>(), "");
91  static_assert(check<B>(), ""); // expected-error {{constant}} expected-note {{in call}}
92  static_assert(check<C>(), "");
93  static_assert(check<D>(), "");
94  static_assert(check<E>(), ""); // expected-error {{constant}} expected-note {{in call}}
95  static_assert(check<F>(), "");
96#endif
97
98  union G {
99    int a = 0; // expected-note {{previous initialization is here}}
100    int b = 0; // expected-error {{initializing multiple members of union}}
101  };
102  union H {
103    union {
104      int a = 0; // expected-note {{previous initialization is here}}
105    };
106    union {
107      int b = 0; // expected-error {{initializing multiple members of union}}
108    };
109  };
110  struct I {
111    union {
112      int a = 0; // expected-note {{previous initialization is here}}
113      int b = 0; // expected-error {{initializing multiple members of union}}
114    };
115  };
116  struct J {
117    union { int a = 0; };
118    union { int b = 0; };
119  };
120
121  namespace Overriding {
122    struct A {
123      int a = 1, b, c = 3;
124      constexpr A() : b(2) {}
125    };
126    static_assert(A().a == 1 && A().b == 2 && A().c == 3, "");
127
128    union B {
129      int a, b = 2, c;
130      constexpr B() : a(1) {}
131      constexpr B(char) : b(4) {}
132      constexpr B(int) : c(3) {}
133      constexpr B(const char*) {}
134    };
135    static_assert(B().a == 1, "");
136    static_assert(B().b == 2, ""); // expected-error {{constant}} expected-note {{read of}}
137    static_assert(B('x').a == 0, ""); // expected-error {{constant}} expected-note {{read of}}
138    static_assert(B('x').b == 4, "");
139    static_assert(B(123).b == 2, ""); // expected-error {{constant}} expected-note {{read of}}
140    static_assert(B(123).c == 3, "");
141    static_assert(B("").a == 1, ""); // expected-error {{constant}} expected-note {{read of}}
142    static_assert(B("").b == 2, "");
143    static_assert(B("").c == 3, ""); // expected-error {{constant}} expected-note {{read of}}
144
145    struct C {
146      union { int a, b = 2, c; };
147      union { int d, e = 5, f; };
148      constexpr C() : a(1) {}
149      constexpr C(char) : c(3) {}
150      constexpr C(int) : d(4) {}
151      constexpr C(float) : f(6) {}
152      constexpr C(const char*) {}
153    };
154
155    static_assert(C().a == 1, "");
156    static_assert(C().b == 2, ""); // expected-error {{constant}} expected-note {{read of}}
157    static_assert(C().d == 4, ""); // expected-error {{constant}} expected-note {{read of}}
158    static_assert(C().e == 5, "");
159
160    static_assert(C('x').b == 2, ""); // expected-error {{constant}} expected-note {{read of}}
161    static_assert(C('x').c == 3, "");
162    static_assert(C('x').d == 4, ""); // expected-error {{constant}} expected-note {{read of}}
163    static_assert(C('x').e == 5, "");
164
165    static_assert(C(1).b == 2, "");
166    static_assert(C(1).c == 3, ""); // expected-error {{constant}} expected-note {{read of}}
167    static_assert(C(1).d == 4, "");
168    static_assert(C(1).e == 5, ""); // expected-error {{constant}} expected-note {{read of}}
169
170    static_assert(C(1.f).b == 2, "");
171    static_assert(C(1.f).c == 3, ""); // expected-error {{constant}} expected-note {{read of}}
172    static_assert(C(1.f).e == 5, ""); // expected-error {{constant}} expected-note {{read of}}
173    static_assert(C(1.f).f == 6, "");
174
175    static_assert(C("").a == 1, ""); // expected-error {{constant}} expected-note {{read of}}
176    static_assert(C("").b == 2, "");
177    static_assert(C("").c == 3, ""); // expected-error {{constant}} expected-note {{read of}}
178    static_assert(C("").d == 4, ""); // expected-error {{constant}} expected-note {{read of}}
179    static_assert(C("").e == 5, "");
180    static_assert(C("").f == 6, ""); // expected-error {{constant}} expected-note {{read of}}
181
182    struct D;
183    extern const D d;
184    struct D {
185      int a;
186      union {
187        int b = const_cast<D&>(d).a = 1; // not evaluated
188        int c;
189      };
190      constexpr D() : a(0), c(0) {}
191    };
192    constexpr D d {};
193    static_assert(d.a == 0, "");
194  }
195#endif
196}
197