From e817c23f6806a6b9201a0a1f77b51cb863af51e9 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Thu, 20 Feb 2020 13:20:44 +0000 Subject: [PATCH] libstdc++: Issues with range access CPOs (P2091R0) This changes how arrays of unknown bound and/or incomplete element type are handled. * include/bits/range_access.h (ranges::begin): Reject array of incomplete type. (ranges::end, ranges::size): Require arrays to be bounded. (ranges::data): Require lvalue or borrowed_range. (ranges::iterator_t): Remove constraint. * testsuite/std/ranges/access/begin.cc: Do not check array of incomplete type. * testsuite/std/ranges/access/begin_neg.cc: New test. * testsuite/std/ranges/access/end_neg.cc: Adjust expected error. * testsuite/std/ranges/access/size_neg.cc: Adjust expected error. * testsuite/std/ranges/access/ssize.cc: Do not check array of incomplete type. --- libstdc++-v3/ChangeLog | 13 +++++++ libstdc++-v3/include/bits/range_access.h | 42 ++++++++++++---------- libstdc++-v3/testsuite/std/ranges/access/begin.cc | 6 ++-- .../testsuite/std/ranges/access/begin_neg.cc | 39 ++++++++++++++++++++ .../testsuite/std/ranges/access/end_neg.cc | 5 +-- .../testsuite/std/ranges/access/size_neg.cc | 3 +- libstdc++-v3/testsuite/std/ranges/access/ssize.cc | 5 --- 7 files changed, 80 insertions(+), 33 deletions(-) create mode 100644 libstdc++-v3/testsuite/std/ranges/access/begin_neg.cc diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index b4b95df..30cf706 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,18 @@ 2020-02-20 Jonathan Wakely + * include/bits/range_access.h (ranges::begin): Reject array of + incomplete type. + (ranges::end, ranges::size): Require arrays to be bounded. + (ranges::data): Require lvalue or borrowed_range. + (ranges::iterator_t): Remove constraint. + * testsuite/std/ranges/access/begin.cc: Do not check array of + incomplete type. + * testsuite/std/ranges/access/begin_neg.cc: New test. + * testsuite/std/ranges/access/end_neg.cc: Adjust expected error. + * testsuite/std/ranges/access/size_neg.cc: Adjust expected error. + * testsuite/std/ranges/access/ssize.cc: Do not check array of + incomplete type. + * include/std/system_error (error_category::operator<=>) (operator<=>(const error_code&, const error_code&)) (operator<=>(const error_condition&, const error_condition&)): Define diff --git a/libstdc++-v3/include/bits/range_access.h b/libstdc++-v3/include/bits/range_access.h index e7a1930..eb91ade 100644 --- a/libstdc++-v3/include/bits/range_access.h +++ b/libstdc++-v3/include/bits/range_access.h @@ -382,8 +382,8 @@ namespace ranges { __decay_copy(__t.begin()) } -> input_or_output_iterator; }; - template void begin(_Tp&&) = delete; - template void begin(initializer_list<_Tp>&&) = delete; + void begin(auto&) = delete; + void begin(const auto&) = delete; template concept __adl_begin = __class_or_enum> @@ -417,7 +417,9 @@ namespace ranges if constexpr (is_array_v>) { static_assert(is_lvalue_reference_v<_Tp>); - return __t; + using _Up = remove_all_extents_t>; + static_assert(sizeof(_Up) != 0, "not array of incomplete type"); + return __t + 0; } else if constexpr (__member_begin<_Tp>) return __t.begin(); @@ -433,8 +435,8 @@ namespace ranges -> sentinel_for(__t)))>; }; - template void end(_Tp&&) = delete; - template void end(initializer_list<_Tp>&&) = delete; + void end(auto&) = delete; + void end(const auto&) = delete; template concept __adl_end = __class_or_enum> @@ -451,7 +453,7 @@ namespace ranges static constexpr bool _S_noexcept() { - if constexpr (is_array_v>) + if constexpr (is_bounded_array_v>) return true; else if constexpr (__member_end<_Tp>) return noexcept(__decay_copy(std::declval<_Tp&>().end())); @@ -461,15 +463,14 @@ namespace ranges public: template<__maybe_borrowed_range _Tp> - requires is_array_v> || __member_end<_Tp> + requires is_bounded_array_v> || __member_end<_Tp> || __adl_end<_Tp> constexpr auto operator()(_Tp&& __t) const noexcept(_S_noexcept<_Tp>()) { - if constexpr (is_array_v>) + if constexpr (is_bounded_array_v>) { static_assert(is_lvalue_reference_v<_Tp>); - static_assert(is_bounded_array_v>); return __t + extent_v>; } else if constexpr (__member_end<_Tp>) @@ -519,7 +520,8 @@ namespace ranges { __decay_copy(__t.rbegin()) } -> input_or_output_iterator; }; - template void rbegin(_Tp&&) = delete; + void rbegin(auto&) = delete; + void rbegin(const auto&) = delete; template concept __adl_rbegin = __class_or_enum> @@ -582,7 +584,8 @@ namespace ranges -> sentinel_for; }; - template void rend(_Tp&&) = delete; + void rend(auto&) = delete; + void rend(const auto&) = delete; template concept __adl_rend = __class_or_enum> @@ -664,7 +667,8 @@ namespace ranges -> __detail::__is_integer_like; }; - template void size(_Tp&&) = delete; + void size(auto&) = delete; + void size(const auto&) = delete; template concept __adl_size = __class_or_enum> @@ -691,7 +695,7 @@ namespace ranges static constexpr bool _S_noexcept() { - if constexpr (is_array_v>) + if constexpr (is_bounded_array_v>) return true; else if constexpr (__member_size<_Tp>) return noexcept(__decay_copy(std::declval<_Tp>().size())); @@ -704,14 +708,13 @@ namespace ranges public: template - requires is_array_v> + requires is_bounded_array_v> || __member_size<_Tp> || __adl_size<_Tp> || __sentinel_size<_Tp> constexpr auto operator()(_Tp&& __e) const noexcept(_S_noexcept<_Tp>()) { - if constexpr (is_array_v>) + if constexpr (is_bounded_array_v>) { - static_assert(is_bounded_array_v>); return extent_v>; } else if constexpr (__member_size<_Tp>) @@ -826,7 +829,8 @@ namespace ranges } public: - template requires __member_data<_Tp> || __begin_data<_Tp> + template<__maybe_borrowed_range _Tp> + requires __member_data<_Tp> || __begin_data<_Tp> constexpr auto operator()(_Tp&& __e) const noexcept(_S_noexcept<_Tp>()) { @@ -881,8 +885,8 @@ namespace ranges concept borrowed_range = range<_Tp> && __detail::__maybe_borrowed_range<_Tp>; - template - using iterator_t = decltype(ranges::begin(std::declval<_Range&>())); + template + using iterator_t = decltype(ranges::begin(std::declval<_Tp&>())); template using sentinel_t = decltype(ranges::end(std::declval<_Range&>())); diff --git a/libstdc++-v3/testsuite/std/ranges/access/begin.cc b/libstdc++-v3/testsuite/std/ranges/access/begin.cc index b680155..9cbdfe2 100644 --- a/libstdc++-v3/testsuite/std/ranges/access/begin.cc +++ b/libstdc++-v3/testsuite/std/ranges/access/begin.cc @@ -36,10 +36,10 @@ test01() constexpr long b[2] = { }; static_assert( std::ranges::begin(b) == (b + 0) ); - struct Incomplete; - using A = Incomplete[]; // unbounded array of incomplete type + struct X { }; + using A = X[]; // unbounded array extern A& f(); - static_assert( same_as ); + static_assert( same_as ); } void diff --git a/libstdc++-v3/testsuite/std/ranges/access/begin_neg.cc b/libstdc++-v3/testsuite/std/ranges/access/begin_neg.cc new file mode 100644 index 0000000..f314285 --- /dev/null +++ b/libstdc++-v3/testsuite/std/ranges/access/begin_neg.cc @@ -0,0 +1,39 @@ +// Copyright (C) 2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-options "-std=gnu++2a" } +// { dg-do compile { target c++2a } } + +#include + +auto +test01() +{ + using A = int[2]; + extern A&& f(); // rvalue of type that doesn't satisfy borrowed_range + return std::ranges::begin(f()); // { dg-error "no match" } +} + +struct incomplete; +extern incomplete array[2]; + +auto +test02() +{ + return std::ranges::begin(array); // { dg-error "here" } +} +// { dg-error "incomplete type" "" { target *-*-* } 0 } diff --git a/libstdc++-v3/testsuite/std/ranges/access/end_neg.cc b/libstdc++-v3/testsuite/std/ranges/access/end_neg.cc index 3f690faa..e16f684 100644 --- a/libstdc++-v3/testsuite/std/ranges/access/end_neg.cc +++ b/libstdc++-v3/testsuite/std/ranges/access/end_neg.cc @@ -25,9 +25,8 @@ extern int unbounded[]; auto test01() { - return std::ranges::end(unbounded); // { dg-error "here" } + return std::ranges::end(unbounded); // { dg-error "no match" } } -// { dg-error "static assertion failed" "" { target *-*-* } 0 } struct incomplete; extern incomplete array[2]; @@ -38,5 +37,3 @@ test02() return std::ranges::end(array); // { dg-error "here" } } // { dg-error "incomplete type" "" { target *-*-* } 0 } - - diff --git a/libstdc++-v3/testsuite/std/ranges/access/size_neg.cc b/libstdc++-v3/testsuite/std/ranges/access/size_neg.cc index 6ff8c1f..10d9b14 100644 --- a/libstdc++-v3/testsuite/std/ranges/access/size_neg.cc +++ b/libstdc++-v3/testsuite/std/ranges/access/size_neg.cc @@ -25,6 +25,5 @@ extern int unbounded[]; auto test01() { - return std::ranges::size(unbounded); // { dg-error "here" } + return std::ranges::size(unbounded); // { dg-error "no match" } } -// { dg-error "static assertion failed" "" { target *-*-* } 0 } diff --git a/libstdc++-v3/testsuite/std/ranges/access/ssize.cc b/libstdc++-v3/testsuite/std/ranges/access/ssize.cc index 5aa05be..6f5478e 100644 --- a/libstdc++-v3/testsuite/std/ranges/access/ssize.cc +++ b/libstdc++-v3/testsuite/std/ranges/access/ssize.cc @@ -36,11 +36,6 @@ test01() static_assert( std::same_as ); VERIFY( std::ranges::ssize(a2) == 2); static_assert( noexcept(std::ranges::ssize(a2)) ); - - struct Incomplete; - using A = Incomplete[2]; // bounded array of incomplete type - extern A& f(); - static_assert( std::same_as ); } void -- 2.7.4