llvm-project/clang/test/SemaCXX/conditional-expr.cpp

184 lines
6.5 KiB
C++

// RUN: clang-cc -fsyntax-only -verify -faccess-control -std=c++0x %s
// C++ rules for ?: are a lot stricter than C rules, and have to take into
// account more conversion options.
// This test runs in C++0x mode for the contextual conversion of the condition.
struct ToBool { explicit operator bool(); };
struct B;
struct A { A(); A(const B&); };
struct B { operator A() const; };
struct I { operator int(); };
struct J { operator I(); };
struct K { operator double(); };
typedef void (*vfn)();
struct F { operator vfn(); };
struct G { operator vfn(); };
struct Base {
int trick();
A trick() const;
void fn1();
};
struct Derived : Base {
void fn2();
};
struct Convertible { operator Base&(); };
struct Priv : private Base {}; // expected-note 2 {{'private' inheritance specifier here}}
struct Mid : Base {};
struct Fin : Mid, Derived {};
typedef void (Derived::*DFnPtr)();
struct ToMemPtr { operator DFnPtr(); };
struct BadDerived;
struct BadBase { operator BadDerived&(); };
struct BadDerived : BadBase {};
struct Fields {
int i1, i2, b1 : 3, b2 : 3;
};
struct MixedFields {
int i;
volatile int vi;
const int ci;
const volatile int cvi;
};
struct MixedFieldsDerived : MixedFields {
};
enum Enum { EVal };
struct Ambig {
operator short();
operator signed char();
};
void test()
{
// This function tests C++0x 5.16
// p1 (contextually convert to bool)
int i1 = ToBool() ? 0 : 1;
// p2 (one or both void, and throwing)
i1 ? throw 0 : throw 1;
i1 ? test() : throw 1;
i1 ? throw 0 : test();
i1 ? test() : test();
i1 = i1 ? throw 0 : 0;
i1 = i1 ? 0 : throw 0;
i1 ? 0 : test(); // expected-error {{right operand to ? is void, but left operand is of type 'int'}}
i1 ? test() : 0; // expected-error {{left operand to ? is void, but right operand is of type 'int'}}
(i1 ? throw 0 : i1) = 0; // expected-error {{expression is not assignable}}
(i1 ? i1 : throw 0) = 0; // expected-error {{expression is not assignable}}
// p3 (one or both class type, convert to each other)
// b1 (lvalues)
Base base;
Derived derived;
Convertible conv;
Base &bar1 = i1 ? base : derived;
Base &bar2 = i1 ? derived : base;
Base &bar3 = i1 ? base : conv;
Base &bar4 = i1 ? conv : base;
// these are ambiguous
BadBase bb;
BadDerived bd;
(void)(i1 ? bb : bd); // expected-error {{conditional expression is ambiguous; 'struct BadBase' can be converted to 'struct BadDerived' and vice versa}}
(void)(i1 ? bd : bb); // expected-error {{conditional expression is ambiguous}}
// curiously enough (and a defect?), these are not
// for rvalues, hierarchy takes precedence over other conversions
(void)(i1 ? BadBase() : BadDerived());
(void)(i1 ? BadDerived() : BadBase());
// b2.1 (hierarchy stuff)
const Base constret();
const Derived constder();
// should use const overload
A a1((i1 ? constret() : Base()).trick());
A a2((i1 ? Base() : constret()).trick());
A a3((i1 ? constret() : Derived()).trick());
A a4((i1 ? Derived() : constret()).trick());
// should use non-const overload
i1 = (i1 ? Base() : Base()).trick();
i1 = (i1 ? Base() : Base()).trick();
i1 = (i1 ? Base() : Derived()).trick();
i1 = (i1 ? Derived() : Base()).trick();
// should fail: const lost
(void)(i1 ? Base() : constder()); // expected-error {{incompatible operand types ('struct Base' and 'struct Derived const')}}
(void)(i1 ? constder() : Base()); // expected-error {{incompatible operand types ('struct Derived const' and 'struct Base')}}
// FIXME: these are invalid hierarchy conversions
Priv priv;
Fin fin;
(void)(i1 ? Base() : Priv()); // xpected-error private base
(void)(i1 ? Priv() : Base()); // xpected-error private base
(void)(i1 ? Base() : Fin()); // xpected-error ambiguous base
(void)(i1 ? Fin() : Base()); // xpected-error ambiguous base
(void)(i1 ? base : priv); // expected-error {{conversion from 'struct Priv' to inaccessible base class 'struct Base'}}
(void)(i1 ? priv : base); // expected-error {{conversion from 'struct Priv' to inaccessible base class 'struct Base'}}
(void)(i1 ? base : fin); // expected-error {{ambiguous conversion from derived class 'struct Fin' to base class 'struct Base'}}
(void)(i1 ? fin : base); // expected-error {{ambiguous conversion from derived class 'struct Fin' to base class 'struct Base'}}
// b2.2 (non-hierarchy)
i1 = i1 ? I() : i1;
i1 = i1 ? i1 : I();
I i2(i1 ? I() : J());
I i3(i1 ? J() : I());
// "the type [it] woud have if E2 were converted to an rvalue"
vfn pfn = i1 ? F() : test;
pfn = i1 ? test : F();
// these are ambiguous - better messages would be nice
(void)(i1 ? A() : B()); // expected-error {{incompatible operand types}}
(void)(i1 ? B() : A()); // expected-error {{incompatible operand types}}
(void)(i1 ? 1 : Ambig()); // expected-error {{incompatible operand types}}
(void)(i1 ? Ambig() : 1); // expected-error {{incompatible operand types}}
// By the way, this isn't an lvalue:
&(i1 ? i1 : i2); // expected-error {{address expression must be an lvalue or a function designator}}
// p4 (lvalue, same type)
Fields flds;
int &ir1 = i1 ? flds.i1 : flds.i2;
(i1 ? flds.b1 : flds.i2) = 0;
(i1 ? flds.i1 : flds.b2) = 0;
(i1 ? flds.b1 : flds.b2) = 0;
// p5 (conversion to built-in types)
// GCC 4.3 fails these
double d1 = i1 ? I() : K();
pfn = i1 ? F() : G();
DFnPtr pfm;
pfm = i1 ? DFnPtr() : &Base::fn1;
pfm = i1 ? &Base::fn1 : DFnPtr();
// p6 (final conversions)
i1 = i1 ? i1 : ir1;
int *pi1 = i1 ? &i1 : 0;
pi1 = i1 ? 0 : &i1;
i1 = i1 ? i1 : EVal;
i1 = i1 ? EVal : i1;
d1 = i1 ? 'c' : 4.0;
d1 = i1 ? 4.0 : 'c';
Base *pb = i1 ? (Base*)0 : (Derived*)0;
pb = i1 ? (Derived*)0 : (Base*)0;
pfm = i1 ? &Base::fn1 : &Derived::fn2;
pfm = i1 ? &Derived::fn2 : &Base::fn1;
pfm = i1 ? &Derived::fn2 : 0;
pfm = i1 ? 0 : &Derived::fn2;
const int (MixedFieldsDerived::*mp1) =
i1 ? &MixedFields::ci : &MixedFieldsDerived::i;
const volatile int (MixedFields::*mp2) =
i1 ? &MixedFields::ci : &MixedFields::cvi;
(void)(i1 ? &MixedFields::ci : &MixedFields::vi);
// Conversion of primitives does not result in an lvalue.
&(i1 ? i1 : d1); // expected-error {{address expression must be an lvalue or a function designator}}
(void)&(i1 ? flds.b1 : flds.i1); // expected-error {{address of bit-field requested}}
(void)&(i1 ? flds.i1 : flds.b1); // expected-error {{address of bit-field requested}}
// Note the thing that this does not test: since DR446, various situations
// *must* create a separate temporary copy of class objects. This can only
// be properly tested at runtime, though.
}