Tested powerp64le-linux. Pushed to trunk. -- >8 --
I accidentally used && in a fold-expression instead of || which meant that in C++17 the tuple(UElements&&...) constructor only failed its debug assertion if all tuple elements were dangling references. Some missing tests (noted as "TODO") meant this wasn't tested. This fixes the fold expression and adds the missing tests. libstdc++-v3/ChangeLog: PR libstdc++/108822 * include/std/tuple (__glibcxx_no_dangling_refs) [C++17]: Fix wrong fold-operator. * testsuite/20_util/tuple/dangling_ref.cc: Check tuples with one element and three elements. Check allocator-extended constructors. --- libstdc++-v3/include/std/tuple | 2 +- .../testsuite/20_util/tuple/dangling_ref.cc | 156 ++++++++++++------ 2 files changed, 110 insertions(+), 48 deletions(-) diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple index 7a045b3e6a1..be92f1eb973 100644 --- a/libstdc++-v3/include/std/tuple +++ b/libstdc++-v3/include/std/tuple @@ -1299,7 +1299,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // Error if construction from U... would create a dangling ref. # if __cpp_fold_expressions # define __glibcxx_dangling_refs(U) \ - (__reference_constructs_from_temporary(_Elements, U) && ...) + (__reference_constructs_from_temporary(_Elements, U) || ...) # else # define __glibcxx_dangling_refs(U) \ __or_<__bool_constant<__reference_constructs_from_temporary(_Elements, U) \ diff --git a/libstdc++-v3/testsuite/20_util/tuple/dangling_ref.cc b/libstdc++-v3/testsuite/20_util/tuple/dangling_ref.cc index 74fdc242349..b2dcf359438 100644 --- a/libstdc++-v3/testsuite/20_util/tuple/dangling_ref.cc +++ b/libstdc++-v3/testsuite/20_util/tuple/dangling_ref.cc @@ -7,6 +7,7 @@ #if __cplusplus >= 202002L // For C++20 and later, constructors are constrained to disallow dangling. +static_assert(!std::is_constructible_v<std::tuple<const int&>, long>); static_assert(!std::is_constructible_v<std::tuple<const int&, int>, long, int>); static_assert(!std::is_constructible_v<std::tuple<int, const int&>, int, long>); static_assert(!std::is_constructible_v<std::tuple<const int&, int>, @@ -30,76 +31,137 @@ static_assert(!std::is_constructible_v<std::tuple<int, const int&>, void test_ary_ctors() { - std::tuple<const int&, int> t1(1L, 2); - // { dg-error "here" "" { target { c++17_down && hosted } } 33 } - // { dg-error "use of deleted function" "" { target c++20 } 33 } + std::tuple<const int&> t1(1L); + // { dg-error "here" "" { target { c++17_down && hosted } } 34 } + // { dg-error "use of deleted function" "" { target c++20 } 34 } - std::tuple<int, const int&> t2(1, 2L); - // { dg-error "here" "" { target { c++17_down && hosted } } 37 } - // { dg-error "use of deleted function" "" { target c++20 } 37 } + std::tuple<const int&, int> t2(1L, 2); + // { dg-error "here" "" { target { c++17_down && hosted } } 38 } + // { dg-error "use of deleted function" "" { target c++20 } 38 } - std::tuple<const int&, const int&> t3(1L, 2L); - // { dg-error "here" "" { target { c++17_down && hosted } } 41 } - // { dg-error "use of deleted function" "" { target c++20 } 41 } + std::tuple<int, const int&> t3(1, 2L); + // { dg-error "here" "" { target { c++17_down && hosted } } 42 } + // { dg-error "use of deleted function" "" { target c++20 } 42 } - std::tuple<const int&, const int&> t4(std::pair<long, int>{}); - // { dg-error "here" "" { target { c++17_down && hosted } } 45 } - // { dg-error "use of deleted function" "" { target c++20 } 45 } + std::tuple<const int&, const int&> t4(1L, 2L); + // { dg-error "here" "" { target { c++17_down && hosted } } 46 } + // { dg-error "use of deleted function" "" { target c++20 } 46 } - std::pair<int, long> p; - std::tuple<const int&, const int&> t5(p); + std::tuple<const int&, const int&> t5(std::pair<long, int>{}); // { dg-error "here" "" { target { c++17_down && hosted } } 50 } // { dg-error "use of deleted function" "" { target c++20 } 50 } + + std::pair<int, long> p; + std::tuple<const int&, const int&> t6(p); + // { dg-error "here" "" { target { c++17_down && hosted } } 55 } + // { dg-error "use of deleted function" "" { target c++20 } 55 } + + std::tuple<const int&, int, int> t7(1L, 2, 3); + // { dg-error "here" "" { target { c++17_down && hosted } } 59 } + // { dg-error "use of deleted function" "" { target c++20 } 59 } } void test_converting_ctors() { - std::tuple<long, long> t0; + std::tuple<long> t10; - std::tuple<const int&, int> t1(t0); - // { dg-error "here" "" { target { c++17_down && hosted } } 60 } - // { dg-error "use of deleted function" "" { target c++20 } 60 } + std::tuple<const int&> t11(t10); + // { dg-error "here" "" { target { c++17_down && hosted } } 69 } + // { dg-error "use of deleted function" "" { target c++20 } 69 } - std::tuple<int, const int&> t2(t0); - // { dg-error "here" "" { target { c++17_down && hosted } } 64 } - // { dg-error "use of deleted function" "" { target c++20 } 64 } + std::tuple<const int&> t12(std::move(t10)); + // { dg-error "here" "" { target { c++17_down && hosted } } 73 } + // { dg-error "use of deleted function" "" { target c++20 } 73 } - std::tuple<const int&, const int&> t3(t0); - // { dg-error "here" "" { target { c++17_down && hosted } } 68 } - // { dg-error "use of deleted function" "" { target c++20 } 68 } + std::tuple<long, long> t20; - std::tuple<const int&, int> t4(std::move(t0)); - // { dg-error "here" "" { target { c++17_down && hosted } } 72 } - // { dg-error "use of deleted function" "" { target c++20 } 72 } + std::tuple<const int&, int> t21(t20); + // { dg-error "here" "" { target { c++17_down && hosted } } 79 } + // { dg-error "use of deleted function" "" { target c++20 } 79 } - std::tuple<int, const int&> t5(std::move(t0)); - // { dg-error "here" "" { target { c++17_down && hosted } } 76 } - // { dg-error "use of deleted function" "" { target c++20 } 76 } + std::tuple<int, const int&> t22(t20); + // { dg-error "here" "" { target { c++17_down && hosted } } 83 } + // { dg-error "use of deleted function" "" { target c++20 } 83 } - std::tuple<const int&, const int&> t6(std::move(t0)); - // { dg-error "here" "" { target { c++17_down && hosted } } 80 } - // { dg-error "use of deleted function" "" { target c++20 } 80 } + std::tuple<const int&, const int&> t23(t20); + // { dg-error "here" "" { target { c++17_down && hosted } } 87 } + // { dg-error "use of deleted function" "" { target c++20 } 87 } + + std::tuple<const int&, int> t24(std::move(t20)); + // { dg-error "here" "" { target { c++17_down && hosted } } 91 } + // { dg-error "use of deleted function" "" { target c++20 } 91 } + + std::tuple<int, const int&> t25(std::move(t20)); + // { dg-error "here" "" { target { c++17_down && hosted } } 95 } + // { dg-error "use of deleted function" "" { target c++20 } 95 } + + std::tuple<const int&, const int&> t26(std::move(t20)); + // { dg-error "here" "" { target { c++17_down && hosted } } 99 } + // { dg-error "use of deleted function" "" { target c++20 } 99 } std::pair<long, long> p0; - std::tuple<const int&, int> t7(p0); - // { dg-error "here" "" { target { c++17_down && hosted } } 85 } - // { dg-error "use of deleted function" "" { target c++20 } 85 } + std::tuple<const int&, int> t27(p0); + // { dg-error "here" "" { target { c++17_down && hosted } } 104 } + // { dg-error "use of deleted function" "" { target c++20 } 104 } - std::tuple<int, const int&> t8(p0); - // { dg-error "here" "" { target { c++17_down && hosted } } 89 } - // { dg-error "use of deleted function" "" { target c++20 } 89 } + std::tuple<int, const int&> t28(p0); + // { dg-error "here" "" { target { c++17_down && hosted } } 108 } + // { dg-error "use of deleted function" "" { target c++20 } 108 } - std::tuple<const int&, int> t9(std::move(p0)); - // { dg-error "here" "" { target { c++17_down && hosted } } 93 } - // { dg-error "use of deleted function" "" { target c++20 } 93 } + std::tuple<const int&, int> t29(std::move(p0)); + // { dg-error "here" "" { target { c++17_down && hosted } } 112 } + // { dg-error "use of deleted function" "" { target c++20 } 112 } - std::tuple<int, const int&> t10(std::move(p0)); - // { dg-error "here" "" { target { c++17_down && hosted } } 97 } - // { dg-error "use of deleted function" "" { target c++20 } 97 } + std::tuple<int, const int&> t210(std::move(p0)); + // { dg-error "here" "" { target { c++17_down && hosted } } 116 } + // { dg-error "use of deleted function" "" { target c++20 } 116 } } -// TODO: test allocator-extended ctors -// TODO: test 1-tuple or 3-tuple, not just 2-tuple +#include <memory> + +void +test_allocator_extended_ctors() +{ + std::allocator<int> a; + + std::tuple<const int&> t1(std::allocator_arg, a, 1L); + // { dg-error "here" "" { target { c++17_down && hosted } } 128 } + // { dg-error "use of deleted function" "" { target c++20 } 128 } + + std::tuple<const int&, int> t2(std::allocator_arg, a, 1L, 2); + // { dg-error "here" "" { target { c++17_down && hosted } } 132 } + // { dg-error "use of deleted function" "" { target c++20 } 132 } + + std::tuple<long> tl; + + std::tuple<const int&> t3(std::allocator_arg, a, tl); + // { dg-error "here" "" { target { c++17_down && hosted } } 138 } + // { dg-error "use of deleted function" "" { target c++20 } 138 } + + std::tuple<const int&> t4(std::allocator_arg, a, std::move(tl)); + // { dg-error "here" "" { target { c++17_down && hosted } } 142 } + // { dg-error "use of deleted function" "" { target c++20 } 142 } + + std::tuple<long, long> tll; + + std::tuple<const int&, int> t5(std::allocator_arg, a, tll); + // { dg-error "here" "" { target { c++17_down && hosted } } 148 } + // { dg-error "use of deleted function" "" { target c++20 } 148 } + + std::tuple<const int&, int> t6(std::allocator_arg, a, std::move(tll)); + // { dg-error "here" "" { target { c++17_down && hosted } } 152 } + // { dg-error "use of deleted function" "" { target c++20 } 152 } + + std::pair<long, long> pll; + + std::tuple<const int&, int> t7(std::allocator_arg, a, pll); + // { dg-error "here" "" { target { c++17_down && hosted } } 158 } + // { dg-error "use of deleted function" "" { target c++20 } 158 } + + std::tuple<const int&, int> t8(std::allocator_arg, a, std::move(pll)); + // { dg-error "here" "" { target { c++17_down && hosted } } 162 } + // { dg-error "use of deleted function" "" { target c++20 } 162 } +} // { dg-error "static assert.* dangling reference" "" { target { c++17_down && hosted } } 0 } -- 2.43.0