clang/test/CXX/class/class.union/p1.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 %s
   2
   3 void abort() __attribute__((noreturn));
   4
   5 class Okay {
   6   int a_;
   7 };
   8
   9 class Virtual {
  10   virtual void foo() { abort(); } // expected-note 4 {{because type 'Virtual' has a virtual member function}}
  11 };
  12
  13 class VirtualBase : virtual Okay { // expected-note 4 {{because type 'VirtualBase' has a virtual base class}}
  14 };
  15
  16 class Ctor {
  17   Ctor() { abort(); } // expected-note 2{{because type 'Ctor' has a user-provided default constructor}} expected-note 2{{here}}
  18 };
  19 class Ctor2 {
  20   Ctor2(); // expected-note {{because type 'Ctor2' has a user-provided default constructor}} expected-note 2{{here}}
  21 };
  22 class CtorTmpl { // expected-note {{because type 'CtorTmpl' has no default constructor}}
  23   template<typename T> CtorTmpl(); // expected-note {{implicit default constructor suppressed by user-declared constructor}}
  24 };
  25
  26 class CopyCtor { // expected-note 2{{because no constructor can be used to copy an object of type 'const CopyCtor'}}
  27   CopyCtor(CopyCtor &cc) { abort(); }
  28 };
  29
  30 class CopyAssign { // expected-note 2 {{because no assignment operator can be used to copy an object of type 'const CopyAssign'}}
  31   CopyAssign& operator=(CopyAssign& CA) { abort(); }
  32 };
  33
  34 class Dtor {
  35   ~Dtor() { abort(); } // expected-note 2 {{because type 'Dtor' has a user-provided destructor}} expected-note 2{{here}}
  36 };
  37
  38 union U1 {
  39   Virtual v; // expected-error {{union member 'v' has a non-trivial copy constructor}}
  40   VirtualBase vbase; // expected-error {{union member 'vbase' has a non-trivial copy constructor}}
  41   Ctor ctor; // expected-error {{union member 'ctor' has a non-trivial default constructor}}
  42   Ctor2 ctor2; // expected-error {{union member 'ctor2' has a non-trivial default constructor}}
  43   CtorTmpl ctortmpl; // expected-error {{union member 'ctortmpl' has a non-trivial default constructor}}
  44   CopyCtor copyctor; // expected-error {{union member 'copyctor' has a non-trivial copy constructor}}
  45   CopyAssign copyassign; // expected-error {{union member 'copyassign' has a non-trivial copy assignment operator}}
  46   Dtor dtor; // expected-error {{union member 'dtor' has a non-trivial destructor}}
  47   Okay okay;
  48 };
  49
  50 union U2 {
  51   struct {
  52     Virtual v; // expected-note {{because the function selected to copy field of type 'Virtual' is not trivial}}
  53   } m1; // expected-error {{union member 'm1' has a non-trivial copy constructor}}
  54   struct {
  55     VirtualBase vbase; // expected-note {{because the function selected to copy field of type 'VirtualBase' is not trivial}}
  56   } m2; // expected-error {{union member 'm2' has a non-trivial copy constructor}}
  57   struct {
  58     Ctor ctor; // expected-note {{because field of type 'Ctor' has a user-provided default constructor}}
  59   } m3; // expected-error {{union member 'm3' has a non-trivial default constructor}}
  60   struct {
  61     Ctor2 ctor2; // expected-note {{because field of type 'Ctor2' has a user-provided default constructor}}
  62   } m3a; // expected-error {{union member 'm3a' has a non-trivial default constructor}}
  63   struct { // expected-note {{no constructor can be used to copy an object of type 'const}}
  64     CopyCtor copyctor;
  65   } m4; // expected-error {{union member 'm4' has a non-trivial copy constructor}}
  66   struct { // expected-note {{no assignment operator can be used to copy an object of type 'const}}
  67     CopyAssign copyassign;
  68   } m5; // expected-error {{union member 'm5' has a non-trivial copy assignment operator}}
  69   struct {
  70     Dtor dtor; // expected-note {{because field of type 'Dtor' has a user-provided destructor}}
  71   } m6; // expected-error {{union member 'm6' has a non-trivial destructor}}
  72   struct {
  73     Okay okay;
  74   } m7;
  75 };
  76
  77 union U3 {
  78   struct s1 : Virtual { // expected-note {{because the function selected to copy base class of type 'Virtual' is not trivial}}
  79   } m1; // expected-error {{union member 'm1' has a non-trivial copy constructor}}
  80   struct s2 : VirtualBase { // expected-note {{because the function selected to copy base class of type 'VirtualBase' is not trivial}}
  81   } m2; // expected-error {{union member 'm2' has a non-trivial copy constructor}}
  82   struct s3 : Ctor { // expected-note {{because base class of type 'Ctor' has a user-provided default constructor}}
  83   } m3; // expected-error {{union member 'm3' has a non-trivial default constructor}}
  84   struct s3a : Ctor2 { // expected-note {{because base class of type 'Ctor2' has a user-provided default constructor}}
  85   } m3a; // expected-error {{union member 'm3a' has a non-trivial default constructor}}
  86   struct s4 : CopyCtor { // expected-note {{because no constructor can be used to copy an object of type 'const U3::s4'}}
  87   } m4; // expected-error {{union member 'm4' has a non-trivial copy constructor}}
  88   struct s5 : CopyAssign { // expected-note {{because no assignment operator can be used to copy an object of type 'const U3::s5'}}
  89   } m5; // expected-error {{union member 'm5' has a non-trivial copy assignment operator}}
  90   struct s6 : Dtor { // expected-note {{because base class of type 'Dtor' has a user-provided destructor}}
  91   } m6; // expected-error {{union member 'm6' has a non-trivial destructor}}
  92   struct s7 : Okay {
  93   } m7;
  94   struct s8 {
  95     s8(...) = delete; // expected-note {{because it is a variadic function}} expected-warning {{C++11}}
  96   } m8; // expected-error {{union member 'm8' has a non-trivial default constructor}}
  97 };
  98
  99 union U4 {
 100   static int i1; // expected-warning {{static data member 'i1' in union is a C++11 extension}}
 101 };
 102 int U4::i1 = 10;
 103
 104 union U5 {
 105   int& i1; // expected-error {{union member 'i1' has reference type 'int &'}}
 106 };
 107
 108 union U6 {
 109   struct S {
 110     int &i;
 111   } s; // ok
 112 };
 113
 114 template <class A, class B> struct Either {
 115   bool tag;
 116   union { // expected-note 6 {{in instantiation of member class}}
 117     A a;
 118     B b; // expected-error 6 {{non-trivial}}
 119   };
 120
 121   Either(const A& a) : tag(true), a(a) {}
 122   Either(const B& b) : tag(false), b(b) {}
 123 };
 124
 125 void fred() {
 126   Either<int,Virtual> virt(0); // expected-note {{in instantiation of template}}
 127   Either<int,VirtualBase> vbase(0); // expected-note {{in instantiation of template}}
 128   Either<int,Ctor> ctor(0); // expected-note {{in instantiation of template}}
 129   Either<int,CopyCtor> copyctor(0); // expected-note {{in instantiation of template}}
 130   Either<int,CopyAssign> copyassign(0); // expected-note {{in instantiation of template}}
 131   Either<int,Dtor> dtor(0); // expected-note {{in instantiation of template}}
 132   Either<int,Okay> okay(0);
 133 }