llvm-project/clang/test/SemaCXX/cxx2a-consteval.cpp

666 lines
20 KiB
C++

// RUN: %clang_cc1 -std=c++2a -emit-llvm-only -Wno-unused-value %s -verify
typedef __SIZE_TYPE__ size_t;
namespace basic_sema {
consteval int f1(int i) {
return i;
}
consteval constexpr int f2(int i) {
//expected-error@-1 {{cannot combine}}
return i;
}
constexpr auto l_eval = [](int i) consteval {
// expected-note@-1+ {{declared here}}
return i;
};
constexpr consteval int f3(int i) {
//expected-error@-1 {{cannot combine}}
return i;
}
struct A {
consteval int f1(int i) const {
// expected-note@-1 {{declared here}}
return i;
}
consteval A(int i);
consteval A() = default;
consteval ~A() = default; // expected-error {{destructor cannot be declared consteval}}
};
consteval struct B {}; // expected-error {{struct cannot be marked consteval}}
consteval typedef B b; // expected-error {{typedef cannot be consteval}}
consteval int redecl() {return 0;} // expected-note {{previous declaration is here}}
constexpr int redecl() {return 0;} // expected-error {{constexpr declaration of 'redecl' follows consteval declaration}}
consteval int i = 0; // expected-error {{consteval can only be used in function declarations}}
consteval int; // expected-error {{consteval can only be used in function declarations}}
consteval int f1() {} // expected-error {{no return statement in consteval function}}
struct C {
C() {}
~C() {}
};
struct D {
C c;
consteval D() = default; // expected-error {{cannot be consteval}}
consteval ~D() = default; // expected-error {{destructor cannot be declared consteval}}
};
struct E : C {
consteval ~E() {} // expected-error {{cannot be declared consteval}}
};
}
consteval int main() { // expected-error {{'main' is not allowed to be declared consteval}}
return 0;
}
consteval int f_eval(int i) {
// expected-note@-1+ {{declared here}}
return i;
}
namespace taking_address {
using func_type = int(int);
func_type* p1 = (&f_eval);
// expected-error@-1 {{take address}}
func_type* p7 = __builtin_addressof(f_eval);
// expected-error@-1 {{take address}}
auto p = f_eval;
// expected-error@-1 {{take address}}
auto m1 = &basic_sema::A::f1;
// expected-error@-1 {{take address}}
auto l1 = &decltype(basic_sema::l_eval)::operator();
// expected-error@-1 {{take address}}
consteval int f(int i) {
// expected-note@-1+ {{declared here}}
return i;
}
auto ptr = &f;
// expected-error@-1 {{take address}}
auto f1() {
return &f;
// expected-error@-1 {{take address}}
}
}
namespace invalid_function {
struct A {
consteval void *operator new(size_t count);
// expected-error@-1 {{'operator new' cannot be declared consteval}}
consteval void *operator new[](size_t count);
// expected-error@-1 {{'operator new[]' cannot be declared consteval}}
consteval void operator delete(void* ptr);
// expected-error@-1 {{'operator delete' cannot be declared consteval}}
consteval void operator delete[](void* ptr);
// expected-error@-1 {{'operator delete[]' cannot be declared consteval}}
consteval ~A() {}
// expected-error@-1 {{destructor cannot be declared consteval}}
};
}
namespace nested {
consteval int f() {
return 0;
}
consteval int f1(...) {
return 1;
}
enum E {};
using T = int(&)();
consteval auto operator+ (E, int(*a)()) {
return 0;
}
void d() {
auto i = f1(E() + &f);
}
auto l0 = [](auto) consteval {
return 0;
};
int i0 = l0(&f1);
int i1 = f1(l0(4));
int i2 = f1(&f1, &f1, &f1, &f1, &f1, &f1, &f1);
int i3 = f1(f1(f1(&f1, &f1), f1(&f1, &f1), f1(f1(&f1, &f1), &f1)));
}
namespace user_defined_literal {
consteval int operator"" _test(unsigned long long i) {
// expected-note@-1+ {{declared here}}
return 0;
}
int i = 0_test;
auto ptr = &operator"" _test;
// expected-error@-1 {{take address}}
consteval auto operator"" _test1(unsigned long long i) {
return &f_eval;
}
auto i1 = 0_test1; // expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}}
}
namespace return_address {
consteval int f() {
// expected-note@-1 {{declared here}}
return 0;
}
consteval int(*ret1(int i))() {
return &f;
}
auto ptr = ret1(0);
// expected-error@-1 {{is not a constant expression}}
// expected-note@-2 {{pointer to a consteval}}
struct A {
consteval int f(int) {
// expected-note@-1+ {{declared here}}
return 0;
}
};
using mem_ptr_type = int (A::*)(int);
template<mem_ptr_type ptr>
struct C {};
C<&A::f> c;
// expected-error@-1 {{is not a constant expression}}
// expected-note@-2 {{pointer to a consteval}}
consteval mem_ptr_type ret2() {
return &A::f;
}
C<ret2()> c1;
// expected-error@-1 {{is not a constant expression}}
// expected-note@-2 {{pointer to a consteval}}
}
namespace context {
int g_i;
// expected-note@-1 {{declared here}}
consteval int f(int) {
return 0;
}
constexpr int c_i = 0;
int t1 = f(g_i);
// expected-error@-1 {{is not a constant expression}}
// expected-note@-2 {{read of non-const variable}}
int t3 = f(c_i);
constexpr int f_c(int i) {
// expected-note@-1 {{declared here}}
int t = f(i);
// expected-error@-1 {{is not a constant expression}}
// expected-note@-2 {{function parameter}}
return f(0);
}
consteval int f_eval(int i) {
return f(i);
}
auto l0 = [](int i) consteval {
return f(i);
};
auto l1 = [](int i) constexpr {
// expected-note@-1 {{declared here}}
int t = f(i);
// expected-error@-1 {{is not a constant expression}}
// expected-note@-2 {{function parameter}}
return f(0);
};
}
namespace std {
template <typename T> struct remove_reference { using type = T; };
template <typename T> struct remove_reference<T &> { using type = T; };
template <typename T> struct remove_reference<T &&> { using type = T; };
template <typename T>
constexpr typename std::remove_reference<T>::type&& move(T &&t) noexcept {
return static_cast<typename std::remove_reference<T>::type &&>(t);
}
}
namespace temporaries {
struct A {
consteval int ret_i() const { return 0; }
consteval A ret_a() const { return A{}; }
constexpr ~A() { }
};
consteval int by_value_a(A a) { return a.ret_i(); }
consteval int const_a_ref(const A &a) {
return a.ret_i();
}
consteval int rvalue_ref(const A &&a) {
return a.ret_i();
}
consteval const A &to_lvalue_ref(const A &&a) {
return a;
}
void test() {
constexpr A a {};
{ int k = A().ret_i(); }
{ A k = A().ret_a(); }
{ A k = to_lvalue_ref(A()); }// expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}} expected-note@-1 {{temporary created here}}
{ A k = to_lvalue_ref(A().ret_a()); } // expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}} expected-note@-1 {{temporary created here}}
{ int k = A().ret_a().ret_i(); }
{ int k = by_value_a(A()); }
{ int k = const_a_ref(A()); }
{ int k = const_a_ref(a); }
{ int k = rvalue_ref(A()); }
{ int k = rvalue_ref(std::move(a)); }
{ int k = const_a_ref(A().ret_a()); }
{ int k = const_a_ref(to_lvalue_ref(A().ret_a())); }
{ int k = const_a_ref(to_lvalue_ref(std::move(a))); }
{ int k = by_value_a(A().ret_a()); }
{ int k = by_value_a(to_lvalue_ref(std::move(a))); }
{ int k = (A().ret_a(), A().ret_i()); }
{ int k = (const_a_ref(A().ret_a()), A().ret_i()); }//
}
}
namespace alloc {
consteval int f() {
int *A = new int(0);
// expected-note@-1+ {{allocation performed here was not deallocated}}
return *A;
}
int i1 = f(); // expected-error {{is not a constant expression}}
struct A {
int* p = new int(42);
// expected-note@-1+ {{heap allocation performed here}}
consteval int ret_i() const { return p ? *p : 0; }
consteval A ret_a() const { return A{}; }
constexpr ~A() { delete p; }
};
consteval int by_value_a(A a) { return a.ret_i(); }
consteval int const_a_ref(const A &a) {
return a.ret_i();
}
consteval int rvalue_ref(const A &&a) {
return a.ret_i();
}
consteval const A &to_lvalue_ref(const A &&a) {
return a;
}
void test() {
constexpr A a{ nullptr };
{ int k = A().ret_i(); }
{ A k = A().ret_a(); } // expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}}
{ A k = to_lvalue_ref(A()); } // expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}} expected-note@-1 {{temporary created here}}
{ A k = to_lvalue_ref(A().ret_a()); } // expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}} expected-note@-1 {{temporary created here}}
{ int k = A().ret_a().ret_i(); }
{ int k = by_value_a(A()); }
{ int k = const_a_ref(A()); }
{ int k = const_a_ref(a); }
{ int k = rvalue_ref(A()); }
{ int k = rvalue_ref(std::move(a)); }
{ int k = const_a_ref(A().ret_a()); }
{ int k = const_a_ref(to_lvalue_ref(A().ret_a())); }
{ int k = const_a_ref(to_lvalue_ref(std::move(a))); }
{ int k = by_value_a(A().ret_a()); }
{ int k = by_value_a(to_lvalue_ref(static_cast<const A&&>(a))); }
{ int k = (A().ret_a(), A().ret_i()); }// expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}}
{ int k = (const_a_ref(A().ret_a()), A().ret_i()); }
}
}
namespace self_referencing {
struct S {
S* ptr = nullptr;
constexpr S(int i) : ptr(this) {
if (this == ptr && i)
ptr = nullptr;
}
constexpr ~S() {}
};
consteval S f(int i) {
return S(i);
}
void test() {
S s(1);
s = f(1);
s = f(0); // expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}} expected-note@-1 {{temporary created here}}
}
struct S1 {
S1* ptr = nullptr;
consteval S1(int i) : ptr(this) {
if (this == ptr && i)
ptr = nullptr;
}
constexpr ~S1() {}
};
void test1() {
S1 s(1);
s = S1(1);
s = S1(0); // expected-error {{is not a constant expression}}
// expected-note@-1 {{is not a constant expression}} expected-note@-1 {{temporary created here}}
}
}
namespace ctor {
consteval int f_eval() { // expected-note+ {{declared here}}
return 0;
}
namespace std {
struct strong_ordering {
int n;
static const strong_ordering less, equal, greater;
};
constexpr strong_ordering strong_ordering::less = {-1};
constexpr strong_ordering strong_ordering::equal = {0};
constexpr strong_ordering strong_ordering::greater = {1};
constexpr bool operator!=(strong_ordering, int);
}
namespace override {
struct A {
virtual consteval void f(); // expected-note {{overridden}}
virtual void g(); // expected-note {{overridden}}
};
struct B : A {
consteval void f();
void g();
};
struct C : A {
void f(); // expected-error {{non-consteval function 'f' cannot override a consteval function}}
consteval void g(); // expected-error {{consteval function 'g' cannot override a non-consteval function}}
};
namespace implicit_equals_1 {
struct Y;
struct X {
std::strong_ordering operator<=>(const X&) const;
constexpr bool operator==(const X&) const;
virtual consteval bool operator==(const Y&) const; // expected-note {{here}}
};
struct Y : X {
std::strong_ordering operator<=>(const Y&) const = default;
// expected-error@-1 {{non-consteval function 'operator==' cannot override a consteval function}}
};
}
namespace implicit_equals_2 {
struct Y;
struct X {
constexpr std::strong_ordering operator<=>(const X&) const;
constexpr bool operator==(const X&) const;
virtual bool operator==(const Y&) const; // expected-note {{here}}
};
struct Y : X {
consteval std::strong_ordering operator<=>(const Y&) const = default;
// expected-error@-1 {{consteval function 'operator==' cannot override a non-consteval function}}
};
}
}
namespace operator_rewrite {
struct A {
friend consteval int operator<=>(const A&, const A&) { return 0; }
};
const bool k = A() < A();
static_assert(!k);
A a;
bool k2 = A() < a; // OK, does not access 'a'.
struct B {
friend consteval int operator<=>(const B &l, const B &r) { return r.n - l.n; } // expected-note {{read of }}
int n;
};
static_assert(B() >= B());
B b; // expected-note {{here}}
bool k3 = B() < b; // expected-error-re {{call to consteval function '{{.*}}::operator<=>' is not a constant expression}} expected-note {{in call}}
}
struct A {
int(*ptr)();
consteval A(int(*p)() = nullptr) : ptr(p) {}
};
struct B {
int(*ptr)();
B() : ptr(nullptr) {}
consteval B(int(*p)(), int) : ptr(p) {}
};
void test() {
{ A a; }
{ A a(&f_eval); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B b(nullptr, 0); }
{ B b(&f_eval, 0); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ A a{}; }
{ A a{&f_eval}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B b{nullptr, 0}; }
{ B b{&f_eval, 0}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ A a = A(); }
{ A a = A(&f_eval); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B b = B(nullptr, 0); }
{ B b = B(&f_eval, 0); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ A a = A{}; }
{ A a = A{&f_eval}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B b = B{nullptr, 0}; }
{ B b = B{&f_eval, 0}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ A a; a = A(); }
{ A a; a = A(&f_eval); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B b; b = B(nullptr, 0); }
{ B b; b = B(&f_eval, 0); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ A a; a = A{}; }
{ A a; a = A{&f_eval}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B b; b = B{nullptr, 0}; }
{ B b; b = B{&f_eval, 0}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ A* a; a = new A(); }
{ A* a; a = new A(&f_eval); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B* b; b = new B(nullptr, 0); }
{ B* b; b = new B(&f_eval, 0); } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ A* a; a = new A{}; }
{ A* a; a = new A{&f_eval}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ B* b; b = new B{nullptr, 0}; }
{ B* b; b = new B{&f_eval, 0}; } // expected-error {{is not a constant expression}} expected-note {{to a consteval}}
}
}
namespace copy_ctor {
consteval int f_eval() { // expected-note+ {{declared here}}
return 0;
}
struct Copy {
int(*ptr)();
constexpr Copy(int(*p)() = nullptr) : ptr(p) {}
consteval Copy(const Copy&) = default;
};
constexpr const Copy &to_lvalue_ref(const Copy &&a) {
return a;
}
void test() {
constexpr const Copy C;
// there is no the copy constructor call when its argument is a prvalue because of garanteed copy elision.
// so we need to test with both prvalue and xvalues.
{ Copy c(C); }
{ Copy c((Copy(&f_eval))); }// expected-error {{cannot take address of consteval}}
{ Copy c(std::move(C)); }
{ Copy c(std::move(Copy(&f_eval))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c(to_lvalue_ref((Copy(&f_eval)))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c(to_lvalue_ref(std::move(C))); }
{ Copy c(to_lvalue_ref(std::move(Copy(&f_eval)))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c = Copy(C); }
{ Copy c = Copy(Copy(&f_eval)); }// expected-error {{cannot take address of consteval}}
{ Copy c = Copy(std::move(C)); }
{ Copy c = Copy(std::move(Copy(&f_eval))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c = Copy(to_lvalue_ref(Copy(&f_eval))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c = Copy(to_lvalue_ref(std::move(C))); }
{ Copy c = Copy(to_lvalue_ref(std::move(Copy(&f_eval)))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c; c = Copy(C); }
{ Copy c; c = Copy(Copy(&f_eval)); }// expected-error {{cannot take address of consteval}}
{ Copy c; c = Copy(std::move(C)); }
{ Copy c; c = Copy(std::move(Copy(&f_eval))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c; c = Copy(to_lvalue_ref(Copy(&f_eval))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy c; c = Copy(to_lvalue_ref(std::move(C))); }
{ Copy c; c = Copy(to_lvalue_ref(std::move(Copy(&f_eval)))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy* c; c = new Copy(C); }
{ Copy* c; c = new Copy(Copy(&f_eval)); }// expected-error {{cannot take address of consteval}}
{ Copy* c; c = new Copy(std::move(C)); }
{ Copy* c; c = new Copy(std::move(Copy(&f_eval))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy* c; c = new Copy(to_lvalue_ref(Copy(&f_eval))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
{ Copy* c; c = new Copy(to_lvalue_ref(std::move(C))); }
{ Copy* c; c = new Copy(to_lvalue_ref(std::move(Copy(&f_eval)))); }// expected-error {{is not a constant expression}} expected-note {{to a consteval}}
}
} // namespace special_ctor
namespace unevaluated {
template <typename T, typename U> struct is_same { static const bool value = false; };
template <typename T> struct is_same<T, T> { static const bool value = true; };
long f(); // expected-note {{declared here}}
auto consteval g(auto a) {
return a;
}
auto e = g(f()); // expected-error {{is not a constant expression}}
// expected-note@-1 {{non-constexpr function 'f' cannot be used in a constant expression}}
using T = decltype(g(f()));
static_assert(is_same<long, T>::value);
} // namespace unevaluated
namespace PR50779 {
struct derp {
int b = 0;
};
constexpr derp d;
struct test {
consteval int operator[](int i) const { return {}; }
consteval const derp * operator->() const { return &d; }
consteval int f() const { return 12; } // expected-note 2{{declared here}}
};
constexpr test a;
// We previously rejected both of these overloaded operators as taking the
// address of a consteval function outside of an immediate context, but we
// accepted direct calls to the overloaded operator. Now we show that we accept
// both forms.
constexpr int s = a.operator[](1);
constexpr int t = a[1];
constexpr int u = a.operator->()->b;
constexpr int v = a->b;
// FIXME: I believe this case should work, but we currently reject.
constexpr int w = (a.*&test::f)(); // expected-error {{cannot take address of consteval function 'f' outside of an immediate invocation}}
constexpr int x = a.f();
// Show that we reject when not in an immediate context.
int w2 = (a.*&test::f)(); // expected-error {{cannot take address of consteval function 'f' outside of an immediate invocation}}
}
namespace PR48235 {
consteval int d() {
return 1;
}
struct A {
consteval int a() const { return 1; }
void b() {
this->a() + d(); // expected-error {{call to consteval function 'PR48235::A::a' is not a constant expression}} \
// expected-note {{use of 'this' pointer is only allowed within the evaluation of a call to a 'constexpr' member function}}
}
void c() {
a() + d(); // expected-error {{call to consteval function 'PR48235::A::a' is not a constant expression}} \
// expected-note {{use of 'this' pointer is only allowed within the evaluation of a call to a 'constexpr' member function}}
}
};
} // PR48235