clang/test/SemaCXX/aggregate-initialization.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++14 %s
   3 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++17 %s
   4 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++2a %s
   5
   6 // Verify that using an initializer list for a non-aggregate looks for
   7 // constructors..
   8 struct NonAggr1 { // expected-note 2 {{candidate constructor}}
   9   NonAggr1(int, int) { } // expected-note {{candidate constructor}}
  10
  11   int m;
  12 };
  13
  14 struct Base { };
  15 struct NonAggr2 : public Base { // expected-note 0-3 {{candidate constructor}}
  16   int m;
  17 };
  18
  19 class NonAggr3 { // expected-note 3 {{candidate constructor}}
  20   int m;
  21 };
  22
  23 struct NonAggr4 { // expected-note 3 {{candidate constructor}}
  24   int m;
  25   virtual void f();
  26 };
  27
  28 NonAggr1 na1 = { 17 }; // expected-error{{no matching constructor for initialization of 'NonAggr1'}}
  29 NonAggr2 na2 = { 17 };
  30 NonAggr3 na3 = { 17 }; // expected-error{{no matching constructor for initialization of 'NonAggr3'}}
  31 NonAggr4 na4 = { 17 }; // expected-error{{no matching constructor for initialization of 'NonAggr4'}}
  32 #if __cplusplus <= 201402L
  33 // expected-error@-4{{no matching constructor for initialization of 'NonAggr2'}}
  34 #else
  35 // expected-error@-6{{requires explicit braces}}
  36 NonAggr2 na2b = { {}, 17 }; // ok
  37 #endif
  38
  39 // PR5817
  40 typedef int type[][2];
  41 const type foo = {0};
  42
  43 // Vector initialization.
  44 typedef short __v4hi __attribute__ ((__vector_size__ (8)));
  45 __v4hi v1 = { (void *)1, 2, 3 }; // expected-error {{cannot initialize a vector element of type 'short' with an rvalue of type 'void *'}}
  46
  47 // Array initialization.
  48 int a[] = { (void *)1 }; // expected-error {{cannot initialize an array element of type 'int' with an rvalue of type 'void *'}}
  49
  50 // Struct initialization.
  51 struct S { int a; } s = { (void *)1 }; // expected-error {{cannot initialize a member subobject of type 'int' with an rvalue of type 'void *'}}
  52
  53 // Check that we're copy-initializing the structs.
  54 struct A {
  55   A();
  56   A(int);
  57   ~A();
  58
  59   A(const A&) = delete; // expected-note 0-2{{'A' has been explicitly marked deleted here}}
  60 };
  61
  62 struct B {
  63   A a;
  64 };
  65
  66 struct C {
  67   const A& a;
  68 };
  69
  70 void f() {
  71   A as1[1] = { };
  72   A as2[1] = { 1 };
  73 #if __cplusplus <= 201402L
  74   // expected-error@-2 {{copying array element of type 'A' invokes deleted constructor}}
  75 #endif
  76
  77   B b1 = { };
  78   B b2 = { 1 };
  79 #if __cplusplus <= 201402L
  80   // expected-error@-2 {{copying member subobject of type 'A' invokes deleted constructor}}
  81 #endif
  82
  83   C c1 = { 1 };
  84 }
  85
  86 class Agg {
  87 public:
  88   int i, j;
  89 };
  90
  91 class AggAgg {
  92 public:
  93   Agg agg1;
  94   Agg agg2;
  95 };
  96
  97 AggAgg aggagg = { 1, 2, 3, 4 };
  98
  99 namespace diff_cpp14_dcl_init_aggr_example {
 100   struct derived;
 101   struct base {
 102     friend struct derived;
 103   private:
 104     base();
 105   };
 106   struct derived : base {};
 107
 108   derived d1{};
 109 #if __cplusplus > 201402L
 110   // expected-error@-2 {{private}}
 111   // expected-note@-7 {{here}}
 112 #endif
 113   derived d2;
 114 }
 115
 116 namespace ProtectedBaseCtor {
 117   // FIXME: It's unclear whether f() and g() should be valid in C++1z. What is
 118   // the object expression in a constructor call -- the base class subobject or
 119   // the complete object?
 120   struct A {
 121   protected:
 122     A();
 123   };
 124
 125   struct B : public A {
 126     friend B f();
 127     friend B g();
 128     friend B h();
 129   };
 130
 131   B f() { return {}; }
 132 #if __cplusplus > 201402L
 133   // expected-error@-2 {{protected default constructor}}
 134   // expected-note@-12 {{here}}
 135 #endif
 136
 137   B g() { return {{}}; }
 138 #if __cplusplus <= 201402L
 139   // expected-error@-2 {{no matching constructor}}
 140   // expected-note@-15 3{{candidate}}
 141 #else
 142   // expected-error@-5 {{protected default constructor}}
 143   // expected-note@-21 {{here}}
 144 #endif
 145
 146   B h() { return {A{}}; }
 147 #if __cplusplus <= 201402L
 148   // expected-error@-2 {{no matching constructor}}
 149   // expected-note@-24 3{{candidate}}
 150 #endif
 151   // expected-error@-5 {{protected constructor}}
 152   // expected-note@-30 {{here}}
 153 }
 154
 155 namespace IdiomaticStdArrayInitDoesNotWarn {
 156 #pragma clang diagnostic push
 157 #pragma clang diagnostic warning "-Wmissing-braces"
 158   template<typename T, int N> struct StdArray {
 159     T contents[N];
 160   };
 161   StdArray<int, 3> x = {1, 2, 3};
 162
 163   template<typename T, int N> struct ArrayAndSomethingElse {
 164     T contents[N];
 165     int something_else;
 166   };
 167   ArrayAndSomethingElse<int, 3> y = {1, 2, 3}; // expected-warning {{suggest braces}}
 168
 169 #if __cplusplus >= 201703L
 170   template<typename T, int N> struct ArrayAndBaseClass : StdArray<int, 3> {
 171     T contents[N];
 172   };
 173   ArrayAndBaseClass<int, 3> z = {1, 2, 3}; // expected-warning {{suggest braces}}
 174
 175   // This pattern is used for tagged aggregates and must not warn
 176   template<typename T, int N> struct JustABaseClass : StdArray<T, N> {};
 177   JustABaseClass<int, 3> w = {1, 2, 3};
 178   // but this should be also ok
 179   JustABaseClass<int, 3> v = {{1, 2, 3}};
 180
 181   template <typename T, int N> struct OnionBaseClass : JustABaseClass<T, N> {};
 182   OnionBaseClass<int, 3> u = {1, 2, 3};
 183   OnionBaseClass<int, 3> t = {{{1, 2, 3}}};
 184
 185   struct EmptyBase {};
 186
 187   template <typename T, int N> struct AggregateAndEmpty : StdArray<T, N>, EmptyBase {};
 188   AggregateAndEmpty<int, 3> p = {1, 2, 3}; // expected-warning {{suggest braces}}
 189 #endif
 190
 191 #pragma clang diagnostic pop
 192 }
 193
 194 namespace HugeArraysUseArrayFiller {
 195   // All we're checking here is that initialization completes in a reasonable
 196   // amount of time.
 197   struct A { int n; int arr[1000 * 1000 * 1000]; } a = {1, {2}};
 198 }
 199
 200 namespace ElementDestructor {
 201   // The destructor for each element of class type is potentially invoked
 202   // (15.4 [class.dtor]) from the context where the aggregate initialization
 203   // occurs. Produce a diagnostic if an element's destructor isn't accessible.
 204
 205   class X { int f; ~X(); }; // expected-note {{implicitly declared private here}}
 206   struct Y { X x; };
 207
 208   void test0() {
 209     auto *y = new Y {}; // expected-error {{temporary of type 'X' has private destructor}}
 210   }
 211
 212   struct S0 { int f; ~S0() = delete; }; // expected-note 3 {{'~S0' has been explicitly marked deleted here}}
 213   struct S1 { S0 s0; int f; };
 214
 215   S1 test1() {
 216     auto *t = new S1 { .f = 1 }; // expected-error {{attempt to use a deleted function}}
 217     return {2}; // expected-error {{attempt to use a deleted function}}
 218   }
 219
 220   // Check if the type of an array element has a destructor.
 221   struct S2 { S0 a[4]; };
 222
 223   void test2() {
 224     auto *t = new S2 {1,2,3,4}; // expected-error {{attempt to use a deleted function}}
 225   }
 226
 227 #if __cplusplus >= 201703L
 228   namespace BaseDestructor {
 229      struct S0 { int f; ~S0() = delete; }; // expected-note {{'~S0' has been explicitly marked deleted here}}
 230
 231     // Check destructor of base class.
 232     struct S3 : S0 {};
 233
 234     void test3() {
 235       S3 s3 = {1}; // expected-error {{attempt to use a deleted function}}
 236     }
 237   }
 238 #endif
 239
 240   // A's destructor doesn't have to be accessible from the context of C's
 241   // initialization.
 242   struct A { friend struct B; private: ~A(); };
 243   struct B { B(); A a; };
 244   struct C { B b; };
 245   C c = { B() };
 246 }