shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
llvm-project/clang/test/SemaTemplate/pack-deduction.cpp
Younan Zhang 5c55f9664f
[Clang] Don't assume unexpanded PackExpansions' size when expanding packs (#120380) 
CheckParameterPacksForExpansion() previously assumed that template
arguments don't include PackExpansion types when attempting another pack
expansion (i.e. when NumExpansions is present). However, this assumption
doesn't hold for type aliases, whose substitution might involve
unexpanded packs. This can lead to incorrect diagnostics during
substitution because the pack size is not yet determined.

To address this, this patch calculates the minimum pack size (ignoring
unexpanded PackExpansionTypes) and compares it to the previously
expanded size. If the minimum pack size is smaller, then there's still a
chance for future substitution to expand it to a correct size, so we
don't diagnose it too eagerly.

Fixes #61415
Fixes #32252
Fixes #17042
2024-12-19 13:12:01 +08:00

261 lines
10 KiB
C++
Raw Blame History

// RUN: %clang_cc1 -std=c++11 -verify %s
template<typename ...T> struct X {};
template<typename T, typename U> struct P {};
namespace Nested {
template<typename ...T> int f1(X<T, T...>... a); // expected-note +{{packs of different lengths for parameter 'T'}}
template<typename ...T> int f2(P<X<T...>, T> ...a); // expected-note +{{packs of different lengths for parameter 'T'}}
int a1 = f1(X<int, int, double>(), X<double, int, double>());
int a2 = f1(X<int, int>());
int a3 = f1(X<int>(), X<double>()); // expected-error {{no matching}}
int a4 = f1(X<int, int>(), X<int>()); // expected-error {{no matching}}
int a5 = f1(X<int>(), X<int, int>()); // expected-error {{no matching}}
int a6 = f1(X<int, int, int>(), X<int, int, int>(), X<int, int, int, int>()); // expected-error {{no matching}}
int b1 = f2(P<X<int, double>, int>(), P<X<int, double>, double>());
int b2 = f2(P<X<int, double>, int>(), P<X<int, double>, double>(), P<X<int, double>, char>()); // expected-error {{no matching}}
}
namespace PR14841 {
template<typename T, typename U> struct A {};
template<typename ...Ts> void f(A<Ts...>); // expected-note {{substitution failure [with Ts = <char, short, int>]: too many template arg}}
void g(A<char, short> a) {
f(a);
f<char>(a);
f<char, short>(a);
f<char, short, int>(a); // expected-error {{no matching function}}
}
}
namespace RetainExprPacks {
int f(int a, int b, int c);
template<typename ...Ts> struct X {};
template<typename ...Ts> int g(X<Ts...>, decltype(f(Ts()...)));
int n = g<int, int>(X<int, int, int>(), 0);
}
namespace PR14615 {
namespace comment0 {
template <class A, class...> struct X {};
template <class... B> struct X<int, B...> {
typedef int type;
struct valid {};
};
template <typename A, typename... B, typename T = X<A, B...>,
typename = typename T::valid>
typename T::type check(int);
int i = check<int, char>(1);
}
namespace comment2 {
template <class...> struct X;
template <typename... B, typename X<B...>::type I = 0>
char check(B...); // expected-note {{undefined template 'PR14615::comment2::X<char, int>'}}
void f() { check<char>(1, 2); } // expected-error {{no matching function}}
}
namespace comment3 {
template <class...> struct X;
template <typename... B, typename X<B...>::type I = (typename X<B...>::type)0>
char check(B...); // expected-note {{undefined template 'PR14615::comment3::X<char, int>'}}
void f() { check<char>(1, 2); } // expected-error {{no matching function}}
}
}
namespace fully_expanded_packs {
template<typename ...T> struct A {
template<T ...X> static constexpr int f() {
// expected-note@-1 1+{{deduced too few arguments for expanded pack 'X'}}
// expected-note@-2 1+{{too many template arguments}}
return (X + ... + 0); // expected-warning {{extension}}
}
template<T ...X, int Y> static constexpr int g() {
// expected-note@-1 1+{{deduced too few arguments for expanded pack 'X'}}
// expected-note@-2 1+{{couldn't infer template argument 'Y'}}
// expected-note@-3 1+{{too many template arguments}}
return (X + ... + (1000 * Y)); // expected-warning {{extension}}
}
template<T ...X, int Y, T ...Z> static constexpr int h() {
// expected-note@-1 1+{{deduced too few arguments for expanded pack 'X'}}
// expected-note@-2 1+{{couldn't infer template argument 'Y'}}
// expected-note@-3 1+{{deduced too few arguments for expanded pack 'Z'}}
// expected-note@-4 1+{{too many template arguments}}
return (X + ... + (1000 * Y)) + 1000000 * (Z + ... + 0); // expected-warning 2{{extension}}
}
template<T ...X, int ...Z> static constexpr int i() {
return (X + ... + 0) + 1000 * (Z + ... + 0); // expected-warning 2{{extension}}
}
template<T ...X, int Y, int ...Z> static constexpr int j() {
return (X + ... + (1000 * Y)) + 1000000 * (Z + ... + 0); // expected-warning 2{{extension}}
}
};
void check_invalid_calls() {
A<int, int>::f(); // expected-error {{no matching function}}
A<int, int>::f<>(); // expected-error {{no matching function}}
A<int, int>::f<0>(); // expected-error {{no matching function}}
A<int, int>::g(); // expected-error {{no matching function}}
A<int, int>::g<>(); // expected-error {{no matching function}}
A<int, int>::g<0>(); // expected-error {{no matching function}}
A<int, int>::g<0, 0>(); // expected-error {{no matching function}}
A<>::f<0>(); // expected-error {{no matching function}}
A<>::g(); // expected-error {{no matching function}}
A<>::g<>(); // expected-error {{no matching function}}
A<>::g<0, 0>(); // expected-error {{no matching function}}
A<>::h<>(); // expected-error {{no matching function}}
A<int>::h<>(); // expected-error {{no matching function}}
A<int>::h<0, 0>(); // expected-error {{no matching function}}
A<>::h<0, 0>(); // expected-error {{no matching function}}
}
static_assert(A<>::f() == 0, "");
static_assert(A<int>::f<1>() == 1, "");
static_assert(A<>::g<1>() == 1000, "");
static_assert(A<int>::g<1, 2>() == 2001, "");
static_assert(A<>::h<1>() == 1000, "");
static_assert(A<int>::h<1, 2, 3>() == 3002001, "");
static_assert(A<int, int>::h<1, 20, 3, 4, 50>() == 54003021, "");
static_assert(A<>::i<1>() == 1000, "");
static_assert(A<int>::i<1>() == 1, "");
static_assert(A<>::j<1, 2, 30>() == 32001000, "");
static_assert(A<int>::j<1, 2, 3, 40>() == 43002001, "");
}
namespace partial_full_mix {
template<typename T, typename U> struct pair {};
template<typename ...T> struct tuple {};
template<typename ...T> struct A {
template<typename ...U> static pair<tuple<T...>, tuple<U...>> f(pair<T, U> ...p);
// expected-note@-1 {{[with U = <char, double, long>]: pack expansion contains parameter pack 'U' that has a different length (2 vs. 3) from outer parameter packs}}
// expected-note@-2 {{[with U = <char, double, void>]: pack expansion contains parameter pack 'U' that has a different length (at least 3 vs. 2) from outer parameter packs}}
template<typename ...U> static pair<tuple<T...>, tuple<U...>> g(pair<T, U> ...p, ...);
// expected-note@-1 {{[with U = <char, double, long>]: pack expansion contains parameter pack 'U' that has a different length (2 vs. 3) from outer parameter packs}}
template<typename ...U> static tuple<U...> h(tuple<pair<T, U>..., pair<int, int>>);
// expected-note@-1 {{[with U = <int[2]>]: pack expansion contains parameter pack 'U' that has a different length (2 vs. 1) from outer parameter packs}}
};
pair<tuple<int, float>, tuple<char, double>> k1 = A<int, float>().f<char>(pair<int, char>(), pair<float, double>());
pair<tuple<int, float>, tuple<char, double>> k2 = A<int, float>().f<char>(pair<int, char>(), pair<float, double>(), pair<void, long>()); // expected-error {{no match}}
pair<tuple<int, float>, tuple<char, double>> k3 = A<int, float>().f<char, double, void>(pair<int, char>(), pair<float, double>()); // expected-error {{no match}}
// FIXME: We should accept this by treating the pack 'p' as having a fixed length of 2 here.
pair<tuple<int, float>, tuple<char, double>> k4 = A<int, float>().g<char>(pair<int, char>(), pair<float, double>(), pair<void, long>()); // expected-error {{no match}}
// FIXME: We should accept this by treating the pack of pairs as having a fixed length of 2 here.
tuple<int[2], int[4]> k5 = A<int[1], int[3]>::h<int[2]>(tuple<pair<int[1], int[2]>, pair<int[3], int[4]>, pair<int, int>>()); // expected-error {{no match}}
}
namespace substitution_vs_function_deduction {
template <typename... T> struct A {
template <typename... U> void f(void(*...)(T, U)); // expected-warning {{ISO C++11 requires a parenthesized pack declaration to have a name}}
template <typename... U> void g(void...(T, U)); // expected-note {{could not match 'void (T, U)' against 'void (*)(int, int)'}}
};
void f(int, int) {
A<int>().f(f);
// FIXME: We fail to decay the parameter to a pointer type.
A<int>().g(f); // expected-error {{no match}}
}
}
namespace Nested_Explicit_Specialization {
template <typename>
struct Outer {
template <int>
struct Inner;
template <>
struct Inner<0> {
template <typename... Args>
void Test(Args...) {}
};
};
void Run() {
Outer<void>::Inner<0>().Test(1,1);
}
}
namespace GH107560 {
int bar(...);
template <int> struct Int {};
template <class ...T>
constexpr auto foo(T... x) -> decltype(bar(T(x)...)) { return 10; }
template <class ...T>
constexpr auto baz(Int<foo<T>(T())>... x) -> int { return 1; }
static_assert(baz<Int<1>, Int<2>, Int<3>>(Int<10>(), Int<10>(), Int<10>()) == 1, "");
}
namespace GH17042 {
template <class... Ts> struct X {
template <class... Us> using Y = X<void(Ts, Us)...>; // #GH17042_Y
};
template <class... T>
using any_pairs_list = X<int, int>::Y<T...>; // #any_pairs_list
template <class... T>
using any_pairs_list_2 = X<int, int>::Y<>;
// expected-error@#GH17042_Y {{different length (2 vs. 0)}} \
// expected-note@-1 {{requested here}}
template <class A, class B, class... P>
using any_pairs_list_3 = X<int, int>::Y<A, B, P...>; // #any_pairs_list_3
template <class A, class B, class C, class... P>
using any_pairs_list_4 = X<int, int>::Y<A, B, C, P...>;
// expected-error@#GH17042_Y {{different length (2 vs. at least 3)}} \
// expected-note@-1 {{requested here}}
static_assert(__is_same(any_pairs_list<char, char>, X<void(int, char), void(int, char)>), "");
static_assert(!__is_same(any_pairs_list<char, char, char>, X<void(int, char), void(int, char)>), "");
// expected-error@#GH17042_Y {{different length (2 vs. 3)}} \
// expected-note@#any_pairs_list {{requested here}} \
// expected-note@-1 {{requested here}}
static_assert(__is_same(any_pairs_list_3<char, char>, X<void(int, char), void(int, char)>), "");
static_assert(!__is_same(any_pairs_list_3<char, char, float>, X<void(int, char), void(int, char)>), "");
// expected-error@#GH17042_Y {{different length (2 vs. 3)}} \
// expected-note@#any_pairs_list_3 {{requested here}} \
// expected-note@-1 {{requested here}}
namespace TemplateTemplateParameters {
template <class... T> struct C {};
template <class T, template <class> class... Args1> struct Ttp {
template <template <class> class... Args2>
using B = C<void(Args1<T>, Args2<T>)...>;
};
template <class> struct D {};
template <template <class> class... Args>
using Alias = Ttp<int, D, D>::B<Args...>;
}
namespace NTTP {
template <int... Args1> struct Nttp {
template <int... Args2> using B = Nttp<(Args1 + Args2)...>;
};
template <int... Args> using Alias = Nttp<1, 2, 3>::B<Args...>;
}
}
Reference in New Issue View Git Blame Copy Permalink