Files
clang-p2996/clang/test/SemaTemplate/instantiate-requires-expr.cpp
Matheus Izvekov d057811655 [clang] fix diagnostic printing of expressions ignoring LangOpts (#134693)
Currently when printing a template argument of expression type, the
expression is converted immediately into a string to be sent to the
diagnostic engine, unsing a fake LangOpts.

This makes the expression printing look incorrect for the current
language, besides being inneficient, as we don't actually need to print
the expression if the diagnostic would be ignored.

This fixes a nastiness with the TemplateArgument constructor for
expressions being implicit, and all current users just passing an
expression to a diagnostic were implicitly going through the template
argument path.

The expressions are also being printed unquoted. This will be fixed in a
subsequent patch, as the test churn is much larger.
2025-04-07 23:19:32 -03:00

271 lines
12 KiB
C++

// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify -Wno-unused-value
template<typename T, typename U>
constexpr bool is_same_v = false;
template<typename T>
constexpr bool is_same_v<T, T> = true;
// We use a hack in this file to make the compiler print out the requires
// expression after it has been instantiated - we put false_v<requires {...}> as
// the requires clause of a class template, then instantiate the template.
// The requirement will not be satisfied, and the explaining diagnostic will
// print out false_v<requires {...}> in its raw form (the false_v serves to
// prevent the diagnostic from elaborating on why the requires expr wasn't
// satisfied).
template<bool v>
constexpr bool false_v = false;
template<typename... Ts>
using void_t = void;
// Check that requires parameters are instantiated correctly.
template<typename T> requires
false_v<requires (T t) { requires is_same_v<decltype(t), int>; }>
// expected-note@-1 {{because 'false_v<requires (int t) { requires is_same_v<decltype(t), int>; }>' evaluated to false}}
// expected-note@-2 {{because 'false_v<requires (char t) { requires is_same_v<decltype(t), int>; }>' evaluated to false}}
struct r1 {};
using r1i1 = r1<int>; // expected-error {{constraints not satisfied for class template 'r1' [with T = int]}}
using r1i2 = r1<char>; // expected-error {{constraints not satisfied for class template 'r1' [with T = char]}}
// Check that parameter packs work.
template<typename... Ts> requires
false_v<requires (Ts... ts) {requires ((sizeof(ts) == 2) && ...);}>
// expected-note@-1 {{because 'false_v<requires (short ts, unsigned short ts) { requires (sizeof (ts) == 2) && (sizeof (ts) == 2); }>'}}
// expected-note@-2 {{because 'false_v<requires (short ts) { requires (sizeof (ts) == 2); }>' evaluated to false}}
struct r2 {};
using r2i1 = r2<short, unsigned short>; // expected-error {{constraints not satisfied for class template 'r2' [with Ts = <short, unsigned short>]}}
using r2i2 = r2<short>; // expected-error {{constraints not satisfied for class template 'r2' [with Ts = <short>]}}
template<typename... Ts> requires
false_v<(requires (Ts ts) {requires sizeof(ts) != 0;} && ...)>
// expected-note@-1 {{because 'false_v<requires (short ts) { requires sizeof (ts) != 0; } && requires (unsigned short ts) { requires sizeof (ts) != 0; }>' evaluated to false}}
// expected-note@-2 {{because 'false_v<requires (short ts) { requires sizeof (ts) != 0; }>' evaluated to false}}
struct r3 {};
using r3i1 = r3<short, unsigned short>; // expected-error {{constraints not satisfied for class template 'r3' [with Ts = <short, unsigned short>]}}
using r3i2 = r3<short>; // expected-error {{constraints not satisfied for class template 'r3' [with Ts = <short>]}}
template<typename T>
struct identity { using type = T; };
namespace type_requirement {
struct A {};
// check that nested name specifier is instantiated correctly.
template<typename T> requires false_v<requires { typename T::type; }> // expected-note{{because 'false_v<requires { typename identity<int>::type; }>' evaluated to false}}
struct r1 {};
using r1i = r1<identity<int>>; // expected-error{{constraints not satisfied for class template 'r1' [with T = identity<int>]}}
// check that template argument list is instantiated correctly.
template<typename T>
struct contains_template {
template<typename U> requires is_same_v<contains_template<T>, U>
using temp = int;
};
template<typename T> requires
false_v<requires { typename T::template temp<T>; }>
// expected-note@-1 {{because 'false_v<requires { typename contains_template<int>::template temp<type_requirement::contains_template<int>>; }>' evaluated to false}}
// expected-note@-2 {{because 'false_v<requires { typename contains_template<short>::template temp<type_requirement::contains_template<short>>; }>' evaluated to false}}
struct r2 {};
using r2i1 = r2<contains_template<int>>; // expected-error{{constraints not satisfied for class template 'r2' [with T = type_requirement::contains_template<int>]}}
using r2i2 = r2<contains_template<short>>; // expected-error{{constraints not satisfied for class template 'r2' [with T = type_requirement::contains_template<short>]}}
// substitution error occurs, then requires expr is instantiated again
template<typename T>
struct a {
template<typename U> requires (requires { typename T::a::a; }, false)
// expected-note@-1{{because 'requires { <<error-type>>; } , false' evaluated to false}}
struct r {};
};
using ari = a<int>::r<short>; // expected-error{{constraints not satisfied for class template 'r' [with U = short]}}
// Parameter pack inside expr
template<typename... Ts> requires
false_v<(requires { typename Ts::type; } && ...)>
// expected-note@-1 {{because 'false_v<requires { typename identity<short>::type; } && requires { typename identity<int>::type; } && requires { <<error-type>>; }>' evaluated to false}}
struct r5 {};
using r5i = r5<identity<short>, identity<int>, short>; // expected-error{{constraints not satisfied for class template 'r5' [with Ts = <identity<short>, identity<int>, short>]}}
template<typename... Ts> requires
false_v<(requires { typename void_t<Ts>; } && ...)> // expected-note{{because 'false_v<requires { typename void_t<int>; } && requires { typename void_t<short>; }>' evaluated to false}}
struct r6 {};
using r6i = r6<int, short>; // expected-error{{constraints not satisfied for class template 'r6' [with Ts = <int, short>]}}
template<typename... Ts> requires
false_v<(requires { typename Ts::template aaa<Ts>; } && ...)>
// expected-note@-1 {{because 'false_v<requires { <<error-type>>; } && requires { <<error-type>>; }>' evaluated to false}}
struct r7 {};
using r7i = r7<int, A>; // expected-error{{constraints not satisfied for class template 'r7' [with Ts = <int, type_requirement::A>]}}
}
namespace expr_requirement {
// check that compound/simple requirements are instantiated correctly.
template<typename T> requires false_v<requires { sizeof(T); { sizeof(T) }; }>
// expected-note@-1 {{because 'false_v<requires { sizeof(int); { sizeof(int) }; }>' evaluated to false}}
// expected-note@-2 {{because 'false_v<requires { <<error-expression>>; { sizeof(T) }; }>' evaluated to false}}
struct r1 {};
using r1i1 = r1<int>; // expected-error{{constraints not satisfied for class template 'r1' [with T = int]}}
using r1i2 = r1<void>; // expected-error{{constraints not satisfied for class template 'r1' [with T = void]}}
// substitution error occurs in expr, then expr is instantiated again.
template<typename T>
struct a {
template<typename U> requires (requires { sizeof(T::a); }, false) // expected-note{{because 'requires { <<error-expression>>; } , false' evaluated to false}}
struct r {};
};
using ari = a<int>::r<short>; // expected-error{{constraints not satisfied for class template 'r' [with U = short]}}
// check that the return-type-requirement is instantiated correctly.
template<typename T, typename U = int>
concept C1 = is_same_v<T, U>;
template<typename T> requires false_v<requires(T t) { { t } -> C1<T>; }>
// expected-note@-1 {{because 'false_v<requires (int t) { { t } -> C1<int>; }>' evaluated to false}}
// expected-note@-2 {{because 'false_v<requires (double t) { { t } -> C1<double>; }>' evaluated to false}}
struct r2 {};
using r2i1 = r2<int>; // expected-error{{constraints not satisfied for class template 'r2' [with T = int]}}
using r2i2 = r2<double>; // expected-error{{constraints not satisfied for class template 'r2' [with T = double]}}
// substitution error occurs in return type requirement, then requires expr is
// instantiated again.
template<typename T>
struct b {
template<typename U> requires (requires { { 0 } -> C1<typename T::a>; }, false) // expected-note{{because 'requires { { 0 } -> <<error-type>>; } , false' evaluated to false}}
struct r {};
};
using bri = b<int>::r<short>; // expected-error{{constraints not satisfied for class template 'r' [with U = short]}}
template<typename... Ts> requires
false_v<(requires { { 0 } noexcept -> C1<Ts>; } && ...)>
// expected-note@-1 {{because 'false_v<requires { { 0 } noexcept -> C1<int>; } && requires { { 0 } noexcept -> C1<unsigned int>; }>' evaluated to false}}
struct r3 {};
using r3i = r3<int, unsigned int>; // expected-error{{constraints not satisfied for class template 'r3' [with Ts = <int, unsigned int>]}}
template<typename T>
struct r4 {
constexpr int foo() {
if constexpr (requires { this->invalid(); })
return 1;
else
return 0;
}
constexpr void invalid() requires false { }
};
static_assert(r4<int>{}.foo() == 0);
}
namespace nested_requirement {
// check that constraint expression is instantiated correctly
template<typename T> requires false_v<requires { requires sizeof(T) == 2; }> // expected-note{{because 'false_v<requires { requires sizeof(int) == 2; }>' evaluated to false}}
struct r1 {};
using r1i = r1<int>; // expected-error{{constraints not satisfied for class template 'r1' [with T = int]}}
// substitution error occurs in expr, then expr is instantiated again.
template<typename T>
struct a {
template<typename U> requires
(requires { requires sizeof(T::a) == 0; }, false) // expected-note{{because 'requires { requires <<error-expression>>; } , false' evaluated to false}}
struct r {};
};
using ari = a<int>::r<short>; // expected-error{{constraints not satisfied for class template 'r' [with U = short]}}
// Parameter pack inside expr
template<typename... Ts> requires
false_v<(requires { requires sizeof(Ts) == 0; } && ...)>
// expected-note@-1 {{because 'false_v<requires { requires sizeof(int) == 0; } && requires { requires sizeof(short) == 0; }>' evaluated to false}}
struct r2 {};
using r2i = r2<int, short>; // expected-error{{constraints not satisfied for class template 'r2' [with Ts = <int, short>]}}
}
// Parameter pack inside multiple requirements
template<typename... Ts> requires
false_v<(requires { requires sizeof(Ts) == 0; sizeof(Ts); } && ...)>
// expected-note@-1 {{because 'false_v<requires { requires sizeof(int) == 0; sizeof(Ts); } && requires { requires sizeof(short) == 0; sizeof(Ts); }>' evaluated to false}}
struct r4 {};
using r4i = r4<int, short>; // expected-error{{constraints not satisfied for class template 'r4' [with Ts = <int, short>]}}
template<typename... Ts> requires
false_v<(requires(Ts t) { requires sizeof(t) == 0; t++; } && ...)>
// expected-note@-1 {{because 'false_v<requires (int t) { requires sizeof (t) == 0; t++; } && requires (short t) { requires sizeof (t) == 0; t++; }>' evaluated to false}}
struct r5 {};
using r5i = r5<int, short>; // expected-error{{constraints not satisfied for class template 'r5' [with Ts = <int, short>]}}
template<typename T> requires
false_v<(requires(T t) { T{t}; })> // T{t} creates an "UnevaluatedList" context.
// expected-note@-1 {{because 'false_v<(requires (int t) { int{t}; })>' evaluated to false}}
struct r6 {};
using r6i = r6<int>;
// expected-error@-1 {{constraints not satisfied for class template 'r6' [with T = int]}}
namespace GH73885 {
template <class> // expected-error {{extraneous}}
template <class T> requires(T{})
constexpr bool e_v = true;
static_assert(e_v<bool>);
} // namespace GH73885
namespace GH84020 {
struct B {
template <typename S> void foo();
void bar();
};
template <typename T, typename S> struct A : T {
void foo() {
static_assert(requires { T::template foo<S>(); });
static_assert(requires { T::bar(); });
}
};
template class A<B, double>;
} // namespace GH84020
namespace GH110785 {
struct Foo {
static void f(auto) requires(false) {}
void f(int) {}
static_assert([](auto v) {
return requires { f(v); };
} (0) == false);
};
} // namespace GH110785