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      1 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -fsyntax-only -verify -std=c++11 -Wsign-conversion %s
      2 
      3 // C++ rules for ?: are a lot stricter than C rules, and have to take into
      4 // account more conversion options.
      5 // This test runs in C++11 mode for the contextual conversion of the condition.
      6 
      7 struct ToBool { explicit operator bool(); };
      8 
      9 struct B;
     10 struct A {
     11   A();
     12   A(const B&); // expected-note 2 {{candidate constructor}}
     13 };
     14 struct B { operator A() const; }; // expected-note 2 {{candidate function}}
     15 struct I { operator int(); };
     16 struct J { operator I(); };
     17 struct K { operator double(); };
     18 typedef void (*vfn)();
     19 struct F { operator vfn(); };
     20 struct G { operator vfn(); };
     21 
     22 struct Base {
     23   int trick();
     24   A trick() const;
     25   void fn1();
     26 };
     27 struct Derived : Base {
     28   void fn2();
     29 };
     30 struct Convertible { operator Base&(); };
     31 struct Priv : private Base {}; // expected-note 4 {{declared private here}}
     32 struct Mid : Base {};
     33 struct Fin : Mid, Derived {};
     34 typedef void (Derived::*DFnPtr)();
     35 struct ToMemPtr { operator DFnPtr(); };
     36 
     37 struct BadDerived;
     38 struct BadBase { operator BadDerived&(); };
     39 struct BadDerived : BadBase {};
     40 
     41 struct Fields {
     42   int i1, i2, b1 : 3, b2 : 3;
     43 };
     44 struct MixedFields {
     45   int i;
     46   volatile int vi;
     47   const int ci;
     48   const volatile int cvi;
     49 };
     50 struct MixedFieldsDerived : MixedFields {
     51 };
     52 
     53 enum Enum { EVal };
     54 
     55 struct Ambig {
     56   operator short(); // expected-note 2 {{candidate function}}
     57   operator signed char(); // expected-note 2 {{candidate function}}
     58 };
     59 
     60 struct Abstract {
     61   virtual ~Abstract() = 0; // expected-note {{unimplemented pure virtual method '~Abstract' in 'Abstract'}}
     62 };
     63 
     64 struct Derived1: Abstract {
     65 };
     66 
     67 struct Derived2: Abstract {
     68 };
     69 
     70 void test()
     71 {
     72   // This function tests C++0x 5.16
     73 
     74   // p1 (contextually convert to bool)
     75   int i1 = ToBool() ? 0 : 1;
     76 
     77   // p2 (one or both void, and throwing)
     78   Fields flds;
     79   i1 ? throw 0 : throw 1;
     80   i1 ? test() : throw 1;
     81   i1 ? throw 0 : test();
     82   i1 ? test() : test();
     83   i1 = i1 ? throw 0 : 0;
     84   i1 = i1 ? 0 : throw 0;
     85   i1 = i1 ? (throw 0) : 0;
     86   i1 = i1 ? 0 : (throw 0);
     87   i1 ? 0 : test(); // expected-error {{right operand to ? is void, but left operand is of type 'int'}}
     88   i1 ? test() : 0; // expected-error {{left operand to ? is void, but right operand is of type 'int'}}
     89   (i1 ? throw 0 : i1) = 0;
     90   (i1 ? i1 : throw 0) = 0;
     91   (i1 ? (throw 0) : i1) = 0;
     92   (i1 ? i1 : (throw 0)) = 0;
     93   (i1 ? (void)(throw 0) : i1) = 0; // expected-error {{left operand to ? is void, but right operand is of type 'int'}}
     94   (i1 ? i1 : (void)(throw 0)) = 0; // expected-error {{right operand to ? is void, but left operand is of type 'int'}}
     95   int &throwRef1 = (i1 ? flds.i1 : throw 0);
     96   int &throwRef2 = (i1 ? throw 0 : flds.i1);
     97   int &throwRef3 = (i1 ? flds.b1 : throw 0); // expected-error {{non-const reference cannot bind to bit-field}}
     98   int &throwRef4 = (i1 ? throw 0 : flds.b1); // expected-error {{non-const reference cannot bind to bit-field}}
     99 
    100   // p3 (one or both class type, convert to each other)
    101   // b1 (lvalues)
    102   Base base;
    103   Derived derived;
    104   Convertible conv;
    105   Base &bar1 = i1 ? base : derived;
    106   Base &bar2 = i1 ? derived : base;
    107   Base &bar3 = i1 ? base : conv;
    108   Base &bar4 = i1 ? conv : base;
    109   // these are ambiguous
    110   BadBase bb;
    111   BadDerived bd;
    112   (void)(i1 ? bb : bd); // expected-error {{conditional expression is ambiguous; 'BadBase' can be converted to 'BadDerived' and vice versa}}
    113   (void)(i1 ? bd : bb); // expected-error {{conditional expression is ambiguous}}
    114   // curiously enough (and a defect?), these are not
    115   // for rvalues, hierarchy takes precedence over other conversions
    116   (void)(i1 ? BadBase() : BadDerived());
    117   (void)(i1 ? BadDerived() : BadBase());
    118 
    119   // b2.1 (hierarchy stuff)
    120   extern const Base constret();
    121   extern const Derived constder();
    122   // should use const overload
    123   A a1((i1 ? constret() : Base()).trick());
    124   A a2((i1 ? Base() : constret()).trick());
    125   A a3((i1 ? constret() : Derived()).trick());
    126   A a4((i1 ? Derived() : constret()).trick());
    127   // should use non-const overload
    128   i1 = (i1 ? Base() : Base()).trick();
    129   i1 = (i1 ? Base() : Base()).trick();
    130   i1 = (i1 ? Base() : Derived()).trick();
    131   i1 = (i1 ? Derived() : Base()).trick();
    132   // should fail: const lost
    133   (void)(i1 ? Base() : constder()); // expected-error {{incompatible operand types ('Base' and 'const Derived')}}
    134   (void)(i1 ? constder() : Base()); // expected-error {{incompatible operand types ('const Derived' and 'Base')}}
    135 
    136   Priv priv;
    137   Fin fin;
    138   (void)(i1 ? Base() : Priv()); // expected-error{{private base class}}
    139   (void)(i1 ? Priv() : Base()); // expected-error{{private base class}}
    140   (void)(i1 ? Base() : Fin()); // expected-error{{ambiguous conversion from derived class 'Fin' to base class 'Base':}}
    141   (void)(i1 ? Fin() : Base()); // expected-error{{ambiguous conversion from derived class 'Fin' to base class 'Base':}}
    142   (void)(i1 ? base : priv); // expected-error {{private base class}}
    143   (void)(i1 ? priv : base); // expected-error {{private base class}}
    144   (void)(i1 ? base : fin); // expected-error {{ambiguous conversion from derived class 'Fin' to base class 'Base':}}
    145   (void)(i1 ? fin : base); // expected-error {{ambiguous conversion from derived class 'Fin' to base class 'Base':}}
    146 
    147   // b2.2 (non-hierarchy)
    148   i1 = i1 ? I() : i1;
    149   i1 = i1 ? i1 : I();
    150   I i2(i1 ? I() : J());
    151   I i3(i1 ? J() : I());
    152   // "the type [it] woud have if E2 were converted to an rvalue"
    153   vfn pfn = i1 ? F() : test;
    154   pfn = i1 ? test : F();
    155   (void)(i1 ? A() : B()); // expected-error {{conversion from 'B' to 'A' is ambiguous}}
    156   (void)(i1 ? B() : A()); // expected-error {{conversion from 'B' to 'A' is ambiguous}}
    157   (void)(i1 ? 1 : Ambig()); // expected-error {{conversion from 'Ambig' to 'int' is ambiguous}}
    158   (void)(i1 ? Ambig() : 1); // expected-error {{conversion from 'Ambig' to 'int' is ambiguous}}
    159   // By the way, this isn't an lvalue:
    160   &(i1 ? i1 : i2); // expected-error {{cannot take the address of an rvalue}}
    161 
    162   // p4 (lvalue, same type)
    163   int &ir1 = i1 ? flds.i1 : flds.i2;
    164   (i1 ? flds.b1 : flds.i2) = 0;
    165   (i1 ? flds.i1 : flds.b2) = 0;
    166   (i1 ? flds.b1 : flds.b2) = 0;
    167 
    168   // p5 (conversion to built-in types)
    169   // GCC 4.3 fails these
    170   double d1 = i1 ? I() : K();
    171   pfn = i1 ? F() : G();
    172   DFnPtr pfm;
    173   pfm = i1 ? DFnPtr() : &Base::fn1;
    174   pfm = i1 ? &Base::fn1 : DFnPtr();
    175 
    176   // p6 (final conversions)
    177   i1 = i1 ? i1 : ir1;
    178   int *pi1 = i1 ? &i1 : 0;
    179   pi1 = i1 ? 0 : &i1;
    180   i1 = i1 ? i1 : EVal;
    181   i1 = i1 ? EVal : i1;
    182   d1 = i1 ? 'c' : 4.0;
    183   d1 = i1 ? 4.0 : 'c';
    184   Base *pb = i1 ? (Base*)0 : (Derived*)0;
    185   pb = i1 ? (Derived*)0 : (Base*)0;
    186   pfm = i1 ? &Base::fn1 : &Derived::fn2;
    187   pfm = i1 ? &Derived::fn2 : &Base::fn1;
    188   pfm = i1 ? &Derived::fn2 : 0;
    189   pfm = i1 ? 0 : &Derived::fn2;
    190   const int (MixedFieldsDerived::*mp1) =
    191     i1 ? &MixedFields::ci : &MixedFieldsDerived::i;
    192   const volatile int (MixedFields::*mp2) =
    193     i1 ? &MixedFields::ci : &MixedFields::cvi;
    194   (void)(i1 ? &MixedFields::ci : &MixedFields::vi);
    195   // Conversion of primitives does not result in an lvalue.
    196   &(i1 ? i1 : d1); // expected-error {{cannot take the address of an rvalue}}
    197 
    198   (void)&(i1 ? flds.b1 : flds.i1); // expected-error {{address of bit-field requested}}
    199   (void)&(i1 ? flds.i1 : flds.b1); // expected-error {{address of bit-field requested}}
    200 
    201 
    202   unsigned long test0 = 5;
    203   test0 = test0 ? (long) test0 : test0; // expected-warning {{operand of ? changes signedness: 'long' to 'unsigned long'}}
    204   test0 = test0 ? (int) test0 : test0; // expected-warning {{operand of ? changes signedness: 'int' to 'unsigned long'}}
    205   test0 = test0 ? (short) test0 : test0; // expected-warning {{operand of ? changes signedness: 'short' to 'unsigned long'}}
    206   test0 = test0 ? test0 : (long) test0; // expected-warning {{operand of ? changes signedness: 'long' to 'unsigned long'}}
    207   test0 = test0 ? test0 : (int) test0; // expected-warning {{operand of ? changes signedness: 'int' to 'unsigned long'}}
    208   test0 = test0 ? test0 : (short) test0; // expected-warning {{operand of ? changes signedness: 'short' to 'unsigned long'}}
    209   test0 = test0 ? test0 : (long) 10;
    210   test0 = test0 ? test0 : (int) 10;
    211   test0 = test0 ? test0 : (short) 10;
    212   test0 = test0 ? (long) 10 : test0;
    213   test0 = test0 ? (int) 10 : test0;
    214   test0 = test0 ? (short) 10 : test0;
    215 
    216   int test1;
    217   test0 = test0 ? EVal : test0;
    218   test1 = test0 ? EVal : (int) test0;
    219 
    220   test0 = test0 ? EVal : test1; // expected-warning {{operand of ? changes signedness: 'int' to 'unsigned long'}}
    221   test0 = test0 ? test1 : EVal; // expected-warning {{operand of ? changes signedness: 'int' to 'unsigned long'}}
    222 
    223   test1 = test0 ? EVal : (int) test0;
    224   test1 = test0 ? (int) test0 : EVal;
    225 
    226   // Note the thing that this does not test: since DR446, various situations
    227   // *must* create a separate temporary copy of class objects. This can only
    228   // be properly tested at runtime, though.
    229 
    230   const Abstract &abstract1 = true ? static_cast<const Abstract&>(Derived1()) : Derived2(); // expected-error {{allocating an object of abstract class type 'const Abstract'}}
    231   const Abstract &abstract2 = true ? static_cast<const Abstract&>(Derived1()) : throw 3; // ok
    232 }
    233 
    234 namespace PR6595 {
    235   struct OtherString {
    236     OtherString();
    237     OtherString(const char*);
    238   };
    239 
    240   struct String {
    241     String(const char *);
    242     String(const OtherString&);
    243     operator const char*() const;
    244   };
    245 
    246   void f(bool Cond, String S, OtherString OS) {
    247     (void)(Cond? S : "");
    248     (void)(Cond? "" : S);
    249     const char a[1] = {'a'};
    250     (void)(Cond? S : a);
    251     (void)(Cond? a : S);
    252     (void)(Cond? OS : S);
    253   }
    254 }
    255 
    256 namespace PR6757 {
    257   struct Foo1 {
    258     Foo1();
    259     Foo1(const Foo1&);
    260   };
    261 
    262   struct Foo2 { };
    263 
    264   struct Foo3 {
    265     Foo3();
    266     Foo3(Foo3&); // expected-note{{would lose const qualifier}}
    267   };
    268 
    269   struct Bar {
    270     operator const Foo1&() const;
    271     operator const Foo2&() const;
    272     operator const Foo3&() const;
    273   };
    274 
    275   void f() {
    276     (void)(true ? Bar() : Foo1()); // okay
    277     (void)(true ? Bar() : Foo2()); // okay
    278     (void)(true ? Bar() : Foo3()); // expected-error{{no viable constructor copying temporary}}
    279   }
    280 }
    281 
    282 // Reduced from selfhost.
    283 namespace test1 {
    284   struct A {
    285     enum Foo {
    286       fa, fb, fc, fd, fe, ff
    287     };
    288 
    289     Foo x();
    290   };
    291 
    292   void foo(int);
    293 
    294   void test(A *a) {
    295     foo(a ? a->x() : 0);
    296   }
    297 }
    298 
    299 namespace rdar7998817 {
    300   class X {
    301     X(X&); // expected-note{{declared private here}}
    302 
    303     struct ref { };
    304 
    305   public:
    306     X();
    307     X(ref);
    308 
    309     operator ref();
    310   };
    311 
    312   void f(bool B) {
    313     X x;
    314     (void)(B? x // expected-error{{calling a private constructor of class 'rdar7998817::X'}}
    315            : X());
    316   }
    317 }
    318 
    319 namespace PR7598 {
    320   enum Enum {
    321     v = 1,
    322   };
    323 
    324   const Enum g() {
    325     return v;
    326   }
    327 
    328   const volatile Enum g2() {
    329     return v;
    330   }
    331 
    332   void f() {
    333     const Enum v2 = v;
    334     Enum e = false ? g() : v;
    335     Enum e2 = false ? v2 : v;
    336     Enum e3 = false ? g2() : v;
    337   }
    338 
    339 }
    340 
    341 namespace PR9236 {
    342 #define NULL 0L
    343   void f() {
    344     int i;
    345     (void)(true ? A() : NULL); // expected-error{{non-pointer operand type 'A' incompatible with NULL}}
    346     (void)(true ? NULL : A()); // expected-error{{non-pointer operand type 'A' incompatible with NULL}}
    347     (void)(true ? 0 : A()); // expected-error{{incompatible operand types}}
    348     (void)(true ? nullptr : A()); // expected-error{{non-pointer operand type 'A' incompatible with nullptr}}
    349     (void)(true ? nullptr : i); // expected-error{{non-pointer operand type 'int' incompatible with nullptr}}
    350     (void)(true ? __null : A()); // expected-error{{non-pointer operand type 'A' incompatible with NULL}}
    351     (void)(true ? (void*)0 : A()); // expected-error{{incompatible operand types}}
    352   }
    353 }
    354 
    355 namespace DR587 {
    356   template<typename T>
    357   const T *f(bool b) {
    358     static T t1 = T();
    359     static const T t2 = T();
    360     return &(b ? t1 : t2);
    361   }
    362   struct S {};
    363   template const int *f(bool);
    364   template const S *f(bool);
    365 
    366   extern bool b;
    367   int i = 0;
    368   const int ci = 0;
    369   volatile int vi = 0;
    370   const volatile int cvi = 0;
    371 
    372   const int &cir = b ? i : ci;
    373   volatile int &vir = b ? vi : i;
    374   const volatile int &cvir1 = b ? ci : cvi;
    375   const volatile int &cvir2 = b ? cvi : vi;
    376   const volatile int &cvir3 = b ? ci : vi; // expected-error{{volatile lvalue reference to type 'const volatile int' cannot bind to a temporary of type 'int'}}
    377 }
    378 
    379 namespace PR17052 {
    380   struct X {
    381     int i_;
    382     bool b_;
    383 
    384     int &test() { return b_ ? i_ : throw 1; }
    385   };
    386 }
    387 
    388 namespace PR26448 {
    389 struct Base {};
    390 struct Derived : Base {};
    391 Base b;
    392 Derived d;
    393 typedef decltype(true ? static_cast<Base&&>(b) : static_cast<Derived&&>(d)) x;
    394 typedef Base &&x;
    395 }
    396