1 // RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11
2
3 struct DefaultedDefCtor1 {};
4 struct DefaultedDefCtor2 { DefaultedDefCtor2() = default; };
5 struct DeletedDefCtor { DeletedDefCtor() = delete; DeletedDefCtor(int); }; // expected-note {{explicitly marked deleted here}}
6 class PrivateDefCtor { PrivateDefCtor() = default; public: PrivateDefCtor(int); };
7 struct DeletedDtor { ~DeletedDtor() = delete; }; // expected-note 4{{explicitly marked deleted here}}
8 class PrivateDtor { ~PrivateDtor() = default; };
9 class Friend {
10 Friend() = default; ~Friend() = default;
11 friend struct NotDeleted6c;
12 friend struct NotDeleted7i;
13 friend struct NotDeleted7j;
14 friend struct NotDeleted7k;
15 };
UserProvidedDefCtorUserProvidedDefCtor16 struct UserProvidedDefCtor { UserProvidedDefCtor() {} };
17 int n;
18
19
20 // A defaulted default constructor for a class X is defined as deleted if:
21
22 // - X is a union-like class that has a variant member with a non-trivial
23 // default constructor,
24 union Deleted1a { UserProvidedDefCtor u; }; // expected-note {{default constructor of 'Deleted1a' is implicitly deleted because variant field 'u' has a non-trivial default constructor}}
25 Deleted1a d1a; // expected-error {{implicitly-deleted default constructor}}
26 union NotDeleted1a { DefaultedDefCtor1 nu; };
27 NotDeleted1a nd1a;
28 union NotDeleted1b { DefaultedDefCtor2 nu; };
29 NotDeleted1b nd1b;
30
31 // - any non-static data member with no brace-or-equal-initializer is of
32 // reference type,
33 class Deleted2a {
34 Deleted2a() = default; // expected-note 4{{implicitly deleted here}}
35 int &a; // expected-note 4{{because field 'a' of reference type 'int &' would not be initialized}}
36 };
37 Deleted2a d2a; // expected-error {{implicitly-deleted default constructor}}
38 struct Deleted2b {
39 int &&b; // expected-note {{default constructor of 'Deleted2b' is implicitly deleted because field 'b' of reference type 'int &&' would not be initialized}}
40 };
41 Deleted2b d2b; // expected-error {{deleted default constructor}}
42 class NotDeleted2a { int &a = n; };
43 NotDeleted2a nd2a;
44 class NotDeleted2b { int &a = error; }; // expected-error {{undeclared identifier}}
45 NotDeleted2b nd2b;
46 class NotDeleted2c { int &&a = 0; }; // expected-warning {{binding reference member 'a' to a temporary}} expected-note {{here}}
47 NotDeleted2c nd2c;
48
49 // - any non-variant non-static data member of const qualified type (or array
50 // thereof) with no brace-or-equal-initializer does not have a user-provided
51 // default constructor,
52 class Deleted3a { const int a; }; // expected-note {{because field 'a' of const-qualified type 'const int' would not be initialized}} \
53 expected-warning {{does not declare any constructor}} \
54 expected-note {{will never be initialized}}
55 Deleted3a d3a; // expected-error {{implicitly-deleted default constructor}}
56 class Deleted3b { const DefaultedDefCtor1 a[42]; }; // expected-note {{because field 'a' of const-qualified type 'const DefaultedDefCtor1 [42]' would not be initialized}}
57 Deleted3b d3b; // expected-error {{implicitly-deleted default constructor}}
58 class Deleted3c { const DefaultedDefCtor2 a; }; // expected-note {{because field 'a' of const-qualified type 'const DefaultedDefCtor2' would not be initialized}}
59 Deleted3c d3c; // expected-error {{implicitly-deleted default constructor}}
60 class NotDeleted3a { const int a = 0; };
61 NotDeleted3a nd3a;
62 class NotDeleted3b { const DefaultedDefCtor1 a[42] = {}; };
63 NotDeleted3b nd3b;
64 class NotDeleted3c { const DefaultedDefCtor2 a = DefaultedDefCtor2(); };
65 NotDeleted3c nd3c;
66 union NotDeleted3d { const int a; int b; };
67 NotDeleted3d nd3d;
68 union NotDeleted3e { const DefaultedDefCtor1 a[42]; int b; };
69 NotDeleted3e nd3e;
70 union NotDeleted3f { const DefaultedDefCtor2 a; int b; };
71 NotDeleted3f nd3f;
72 struct NotDeleted3g { union { const int a; int b; }; };
73 NotDeleted3g nd3g;
74
75 // - X is a union and all of its variant members are of const-qualified type (or
76 // array thereof),
77 union Deleted4a {
78 const int a;
79 const int b;
80 const UserProvidedDefCtor c; // expected-note {{because variant field 'c' has a non-trivial default constructor}}
81 };
82 Deleted4a d4a; // expected-error {{implicitly-deleted default constructor}}
83 union NotDeleted4a { const int a; int b; };
84 NotDeleted4a nd4a;
85
86 // - X is a non-union class and all members of any anonymous union member are of
87 // const-qualified type (or array thereof),
88 struct Deleted5a {
89 union { const int a; }; // expected-note {{because all data members of an anonymous union member are const-qualified}}
90 union { int b; };
91 };
92 Deleted5a d5a; // expected-error {{implicitly-deleted default constructor}}
93 struct NotDeleted5a { union { const int a; int b; }; union { const int c; int d; }; };
94 NotDeleted5a nd5a;
95
96 // - any direct or virtual base class, or non-static data member with no
97 // brace-or-equal-initializer, has class type M (or array thereof) and either
98 // M has no default constructor or overload resolution as applied to M's default
99 // constructor results in an ambiguity or in a function that is deleted or
100 // inaccessible from the defaulted default constructor, or
101 struct Deleted6a : Deleted2a {}; // expected-note {{because base class 'Deleted2a' has a deleted default constructor}}
102 Deleted6a d6a; // expected-error {{implicitly-deleted default constructor}}
103 struct Deleted6b : virtual Deleted2a {}; // expected-note {{because base class 'Deleted2a' has a deleted default constructor}}
104 Deleted6b d6b; // expected-error {{implicitly-deleted default constructor}}
105 struct Deleted6c { Deleted2a a; }; // expected-note {{because field 'a' has a deleted default constructor}}
106 Deleted6c d6c; // expected-error {{implicitly-deleted default constructor}}
107 struct Deleted6d { DeletedDefCtor a; }; // expected-note {{because field 'a' has a deleted default constructor}}
108 Deleted6d d6d; // expected-error {{implicitly-deleted default constructor}}
109 struct NotDeleted6a { DeletedDefCtor a = 0; };
110 NotDeleted6a nd6a;
111 struct Deleted6e { PrivateDefCtor a; }; // expected-note {{because field 'a' has an inaccessible default constructor}}
112 Deleted6e d6e; // expected-error {{implicitly-deleted default constructor}}
113 struct NotDeleted6b { PrivateDefCtor a = 0; };
114 NotDeleted6b nd6b;
115 struct NotDeleted6c { Friend a; };
116 NotDeleted6c nd6c;
117
118 // - any direct or virtual base class or non-static data member has a type with
119 // a destructor that is deleted or inaccessible from the defaulted default
120 // constructor.
121 struct Deleted7a : DeletedDtor {}; // expected-note {{because base class 'DeletedDtor' has a deleted destructor}}
122 Deleted7a d7a; // expected-error {{implicitly-deleted default constructor}}
123 struct Deleted7b : virtual DeletedDtor {}; // expected-note {{because base class 'DeletedDtor' has a deleted destructor}}
124 Deleted7b d7b; // expected-error {{implicitly-deleted default constructor}}
125 struct Deleted7c { DeletedDtor a; }; // expected-note {{because field 'a' has a deleted destructor}}
126 Deleted7c d7c; // expected-error {{implicitly-deleted default constructor}}
127 struct Deleted7d { DeletedDtor a = {}; }; // expected-note {{because field 'a' has a deleted destructor}}
128 Deleted7d d7d; // expected-error {{implicitly-deleted default constructor}}
129 struct Deleted7e : PrivateDtor {}; // expected-note {{base class 'PrivateDtor' has an inaccessible destructor}}
130 Deleted7e d7e; // expected-error {{implicitly-deleted default constructor}}
131 struct Deleted7f : virtual PrivateDtor {}; // expected-note {{base class 'PrivateDtor' has an inaccessible destructor}}
132 Deleted7f d7f; // expected-error {{implicitly-deleted default constructor}}
133 struct Deleted7g { PrivateDtor a; }; // expected-note {{field 'a' has an inaccessible destructor}}
134 Deleted7g d7g; // expected-error {{implicitly-deleted default constructor}}
135 struct Deleted7h { PrivateDtor a = {}; }; // expected-note {{field 'a' has an inaccessible destructor}}
136 Deleted7h d7h; // expected-error {{implicitly-deleted default constructor}}
137 struct NotDeleted7i : Friend {};
138 NotDeleted7i d7i;
139 struct NotDeleted7j : virtual Friend {};
140 NotDeleted7j d7j;
141 struct NotDeleted7k { Friend a; };
142 NotDeleted7k d7k;
143
144
145 class Trivial { static const int n = 42; };
146 static_assert(__has_trivial_constructor(Trivial), "Trivial is nontrivial");
147
148 // A default constructor is trivial if it is not user-provided and if:
149 class NonTrivialDefCtor1 { NonTrivialDefCtor1(); };
150 static_assert(!__has_trivial_constructor(NonTrivialDefCtor1), "NonTrivialDefCtor1 is trivial");
151
152 #define ASSERT_NONTRIVIAL_IMPL(Class, Bases, Body) \
153 class Class Bases { Body }; \
154 static_assert(!__has_trivial_constructor(Class), "");
155 #define ASSERT_NONTRIVIAL(Class, Bases, Body) \
156 ASSERT_NONTRIVIAL_IMPL(Class, Bases, Body) \
157 ASSERT_NONTRIVIAL_IMPL(Def ## Class, Bases, Def ## Class() = default; Body) \
158 ASSERT_NONTRIVIAL_IMPL(Del ## Class, Bases, Del ## Class() = delete; Body)
159
160 // - its class has no virtual functions (10.3) and no virtual base classes (10.1), and
161 ASSERT_NONTRIVIAL(NonTrivialDefCtor2, , virtual void f();)
162 ASSERT_NONTRIVIAL(NonTrivialDefCtor3, : virtual Trivial, )
163
164 // - no non-static data member of its class has a brace-or-equal-initializer, and
165 ASSERT_NONTRIVIAL(NonTrivialDefCtor4, , int m = 52;)
166
167 // - all the direct base classes of its class have trivial default constructors, and
168 ASSERT_NONTRIVIAL(NonTrivialDefCtor5, : NonTrivialDefCtor1, )
169
170 // - for all the non-static data members of its class that are of class type (or array thereof), each such class
171 // has a trivial default constructor.
172 ASSERT_NONTRIVIAL(NonTrivialDefCtor6, , NonTrivialDefCtor1 t;)
173
174 // FIXME: No core issue number yet.
175 // - its parameter-declaration-clause is equivalent to that of an implicit declaration.
176 struct NonTrivialDefCtor7 {
177 NonTrivialDefCtor7(...) = delete;
178 };
179 static_assert(!__has_trivial_constructor(NonTrivialDefCtor7), "");
180 struct NonTrivialDefCtor8 {
181 NonTrivialDefCtor8(int = 0) = delete;
182 };
183 static_assert(!__has_trivial_constructor(NonTrivialDefCtor8), "");
184
185 // Otherwise, the default constructor is non-trivial.
186
187 class Trivial2 { Trivial2() = delete; };
188 static_assert(__has_trivial_constructor(Trivial2), "Trivial2 is trivial");
189
190 class Trivial3 { Trivial3() = default; };
191 static_assert(__has_trivial_constructor(Trivial3), "Trivial3 is trivial");
192
193 template<typename T> class Trivial4 { Trivial4() = default; };
194 static_assert(__has_trivial_constructor(Trivial4<int>), "Trivial4 is trivial");
195
196 template<typename T> class Trivial5 { Trivial5() = delete; };
197 static_assert(__has_trivial_constructor(Trivial5<int>), "Trivial5 is trivial");
198
199 namespace PR14558 {
200 // Ensure we determine whether an explicitly-defaulted or deleted special
201 // member is trivial before we return to parsing the containing class.
202 struct A {
203 struct B { B() = default; } b;
204 struct C { C() = delete; } c;
205 };
206
207 static_assert(__has_trivial_constructor(A), "");
208 static_assert(__has_trivial_constructor(A::B), "");
209 }
210