98 lines
3.1 KiB
C++
98 lines
3.1 KiB
C++
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// RUN: %clang_cc1 -std=c++1z -verify %s
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struct A {
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A() {}
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A(int) : A() {} // ok
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virtual void f() = 0; // expected-note 1+{{unimplemented}}
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};
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template<typename> struct SecretlyAbstract {
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SecretlyAbstract();
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SecretlyAbstract(int);
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virtual void f() = 0; // expected-note 1+{{unimplemented}}
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};
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using B = SecretlyAbstract<int>;
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using C = SecretlyAbstract<float>;
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using D = SecretlyAbstract<char>[1];
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B b; // expected-error {{abstract class}}
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D d; // expected-error {{abstract class}}
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template<int> struct N;
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// Note: C is not instantiated anywhere in this file, so we never discover that
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// it is in fact abstract. The C++ standard suggests that we need to
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// instantiate in all cases where abstractness could affect the validity of a
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// program, but that breaks a *lot* of code, so we don't do that.
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//
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// FIXME: Once DR1640 is resolved, remove the check on forming an abstract
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// array type entirely. The only restriction we need is that you can't create
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// an object of abstract (most-derived) type.
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// An abstract class shall not be used
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// - as a parameter type
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void f(A&);
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void f(A); // expected-error {{abstract class}}
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void f(A[1]); // expected-error {{abstract class}}
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void f(B); // expected-error {{abstract class}}
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void f(B[1]); // expected-error {{abstract class}}
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void f(C);
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void f(C[1]);
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void f(D); // expected-error {{abstract class}}
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void f(D[1]); // expected-error {{abstract class}}
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// - as a function return type
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A &f(N<0>);
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A *f(N<1>);
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A f(N<2>); // expected-error {{abstract class}}
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A (&f(N<3>))[2]; // expected-error {{abstract class}}
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B f(N<4>); // expected-error {{abstract class}}
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B (&f(N<5>))[2]; // expected-error {{abstract class}}
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C f(N<6>);
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C (&f(N<7>))[2];
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// - as the type of an explicit conversion
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void g(A&&);
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void h() {
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A(); // expected-error {{abstract class}}
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A(0); // expected-error {{abstract class}}
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A{}; // expected-error {{abstract class}}
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A{0}; // expected-error {{abstract class}}
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(A)(0); // expected-error {{abstract class}}
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(A){}; // expected-error {{abstract class}}
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(A){0}; // expected-error {{abstract class}}
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D(); // expected-error {{array type}}
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D{}; // expected-error {{abstract class}}
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D{0}; // expected-error {{abstract class}}
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(D){}; // expected-error {{abstract class}}
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(D){0}; // expected-error {{abstract class}}
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}
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template<typename T> void t(T); // expected-note 2{{abstract class}}
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void i(A &a, B &b, C &c, D &d) {
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// FIXME: These should be handled consistently. We currently reject the first
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// two early because we (probably incorrectly, depending on dr1640) take
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// abstractness into account in forming implicit conversion sequences.
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t(a); // expected-error {{no matching function}}
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t(b); // expected-error {{no matching function}}
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t(c); // expected-error {{allocating an object of abstract class type}}
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t(d); // ok, decays to pointer
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}
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struct E : A {
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E() : A() {} // ok
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E(int n) : A( A(n) ) {} // expected-error {{abstract class}}
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};
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namespace std {
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template<typename T> struct initializer_list {
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const T *begin, *end;
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initializer_list();
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};
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}
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std::initializer_list<A> ila = {1, 2, 3, 4}; // expected-error {{abstract class}}
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