From e7a0af84d68f50b65dffa1af462d10bd4bf03939 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Mon, 19 Oct 2020 22:11:39 +0100 Subject: [PATCH] libstdc++: Implement std::make_unique_for_overwrite This is the std::unique_ptr part of P1020R1 (as amended by P1973R1) for C++20. The std::shared_ptr part still needs to be done. libstdc++-v3/ChangeLog: * include/bits/unique_ptr.h (make_unique_for_overwrite): Define for C++20. * testsuite/20_util/unique_ptr/creation/array_neg.cc: Remove unused header. Adjust standard reference. * testsuite/20_util/unique_ptr/creation/for_overwrite.cc: New test. * testsuite/20_util/unique_ptr/creation/for_overwrite__neg.cc: New test. --- libstdc++-v3/include/bits/unique_ptr.h | 22 ++++++- .../20_util/unique_ptr/creation/array_neg.cc | 3 +- .../unique_ptr/creation/for_overwrite.cc | 65 +++++++++++++++++++ .../unique_ptr/creation/for_overwrite__neg.cc | 34 ++++++++++ 4 files changed, 121 insertions(+), 3 deletions(-) create mode 100644 libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite.cc create mode 100644 libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite__neg.cc diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h index d0e4cefadd7..252ea89917b 100644 --- a/libstdc++-v3/include/bits/unique_ptr.h +++ b/libstdc++-v3/include/bits/unique_ptr.h @@ -969,8 +969,28 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION /// Disable std::make_unique for arrays of known bound template - inline typename _MakeUniq<_Tp>::__invalid_type + typename _MakeUniq<_Tp>::__invalid_type make_unique(_Args&&...) = delete; + +#if __cplusplus > 201703L + /// std::make_unique_for_overwrite for single objects + template + inline typename _MakeUniq<_Tp>::__single_object + make_unique_for_overwrite() + { return unique_ptr<_Tp>(new _Tp); } + + /// std::make_unique_for_overwrite for arrays of unknown bound + template + inline typename _MakeUniq<_Tp>::__array + make_unique_for_overwrite(size_t __n) + { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__n]); } + + /// Disable std::make_unique_for_overwrite for arrays of known bound + template + typename _MakeUniq<_Tp>::__invalid_type + make_unique_for_overwrite(_Args&&...) = delete; +#endif // C++20 + // @} relates unique_ptr #endif // C++14 diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/creation/array_neg.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/creation/array_neg.cc index 928080d9161..a76cacb1031 100644 --- a/libstdc++-v3/testsuite/20_util/unique_ptr/creation/array_neg.cc +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/creation/array_neg.cc @@ -17,10 +17,9 @@ // with this library; see the file COPYING3. If not see // . -// 20.9.1.4 unique_ptr creation [unique.ptr.create] +// C++14 20.8.1.4 unique_ptr creation [unique.ptr.create] #include -#include struct A { }; diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite.cc new file mode 100644 index 00000000000..e7231c2ac95 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite.cc @@ -0,0 +1,65 @@ +// { dg-options "-std=gnu++20" } +// { dg-do run { target c++2a } } + +// 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 +// . + +// C++20 20.11.1.5 unique_ptr creation [unique.ptr.create] + +#include +#include +#include +#include + +void* operator new(std::size_t n) +{ + void* p = std::malloc(n); + std::memset(p, 0xaa, n); + return p; +} + +void operator delete(void* p) { std::free(p); } +void operator delete(void* p, std::size_t) { std::free(p); } + +void +test01() +{ + std::unique_ptr a = std::make_unique_for_overwrite(); + VERIFY( a != nullptr ); + unsigned char buf[sizeof(int)]; + std::memcpy(buf, a.get(), sizeof(buf)); + for (unsigned char c : buf) + VERIFY( c == 0xaa ); +} + +void +test02() +{ + std::unique_ptr a = std::make_unique_for_overwrite(3); + VERIFY( a != nullptr ); + unsigned char buf[3 * sizeof(int)]; + std::memcpy(buf, a.get(), sizeof(buf)); + for (unsigned char c : buf) + VERIFY( c == 0xaa ); +} + +int +main() +{ + test01(); + test02(); +} diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite__neg.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite__neg.cc new file mode 100644 index 00000000000..3571ae244a6 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/creation/for_overwrite__neg.cc @@ -0,0 +1,34 @@ +// { dg-options "-std=gnu++20" } +// { dg-do compile { target c++2a } } + +// 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 +// . + +// C++20 20.11.1.5 unique_ptr creation [unique.ptr.create] + +#include + +struct A { }; + +auto p1 = std::make_unique_for_overwrite(1); // { dg-error "no matching function" } +auto p1 = std::make_unique_for_overwrite(); // { dg-error "no matching function" } +auto p2 = std::make_unique_for_overwrite(1, 2); // { dg-error "no matching function" } +auto p3 = std::make_unique_for_overwrite(); // { dg-error "deleted" } +auto p4 = std::make_unique_for_overwrite(1);// { dg-error "deleted" } + +// { dg-prune-output "declared here" } +// { dg-prune-output "no type named" } -- 2.30.2