| Message ID | 20181023131029.GA4754@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | PR libstdc++/87704 fix unique_ptr(nullptr_t) constructors | expand |
On 23/10/18 14:10 +0100, Jonathan Wakely wrote: >Using a delegating constructor to implement these constructors means >that they instantiate the destructor, which requires the element_type to >be complete. In C++11 and C++14 they were specified to be delegating, >but that was changed as part of LWG 2801 so in C++17 they don't require >a complete type (as was intended all along). > > PR libstdc++/87704 > * include/bits/unique_ptr.h (unique_ptr::unique_ptr(nullptr_t)): Do > not delegate to default constructor. > (unique_ptr<T[], D>::unique_ptr(nullptr_t)): Likewise. > * testsuite/20_util/unique_ptr/cons/incomplete.cc: New test. > >Tested powerpc64le-linux, committed to trunk. Backports to follow. This is the backport for gcc-6-branch. It's slightly different, because on that branch we make null deleters ill-formed via static_assert, instead of disabling the constructor via SFINAE. If the unique_ptr(nullptr_t) constructors don't delegate to the default constructor they need to duplicate the assertion from the default constructor. Tested x86_64-linux. commit c1a59bedb89bde9f7e45b187409186b2f9763637 Author: redi <redi@138bc75d-0d04-0410-961f-82ee72b054a4> Date: Tue Oct 23 15:55:05 2018 +0000 PR libstdc++/87704 fix unique_ptr(nullptr_t) constructors Using a delegating constructor to implement these constructors means that they instantiate the destructor, which requires the element_type to be complete. In C++11 and C++14 they were specified to be delegating, but that was changed as part of LWG 2801 so in C++17 they don't require a complete type (as was intended all along). Backport from mainline 2018-10-23 Jonathan Wakely <jwakely@redhat.com> PR libstdc++/87704 * include/bits/unique_ptr.h (unique_ptr::unique_ptr(nullptr_t)): Do not delegate to default constructor. (unique_ptr<T[], D>::unique_ptr(nullptr_t)): Likewise. * testsuite/20_util/unique_ptr/cons/incomplete.cc: New test. diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h index 8e302877f78..93c579788b6 100644 --- a/libstdc++-v3/include/bits/unique_ptr.h +++ b/libstdc++-v3/include/bits/unique_ptr.h @@ -201,7 +201,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION "rvalue deleter bound to reference"); } /// Creates a unique_ptr that owns nothing. - constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { } + constexpr unique_ptr(nullptr_t) noexcept : _M_t() + { static_assert(!is_pointer<deleter_type>::value, + "constructed with null function pointer deleter"); } // Move constructors. @@ -491,7 +493,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } /// Creates a unique_ptr that owns nothing. - constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { } + constexpr unique_ptr(nullptr_t) noexcept : _M_t() + { static_assert(!is_pointer<deleter_type>::value, + "constructed with null function pointer deleter"); } template<typename _Up, typename _Ep, typename = _Require<__safe_conversion_up<_Up, _Ep>>> diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/assign/48635_neg.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/assign/48635_neg.cc index 785f9ad4cfd..e64b4535345 100644 --- a/libstdc++-v3/testsuite/20_util/unique_ptr/assign/48635_neg.cc +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/assign/48635_neg.cc @@ -43,10 +43,10 @@ void f() std::unique_ptr<int, D&> ud(nullptr, d); ub = std::move(ud); // { dg-error "no match" } ub2 = ud; // { dg-error "no match" } -// { dg-error "no type" "" { target *-*-* } 272 } +// { dg-error "no type" "" { target *-*-* } 274 } std::unique_ptr<int[], B&> uba(nullptr, b); std::unique_ptr<int[], D&> uda(nullptr, d); uba = std::move(uda); // { dg-error "no match" } -// { dg-error "no type" "" { target *-*-* } 540 } +// { dg-error "no type" "" { target *-*-* } 544 } } diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/cons/cv_qual_neg.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/cv_qual_neg.cc index 285a0b994c9..9b8cba45a57 100644 --- a/libstdc++-v3/testsuite/20_util/unique_ptr/cons/cv_qual_neg.cc +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/cv_qual_neg.cc @@ -40,7 +40,7 @@ test07() std::unique_ptr<const A[]> cA3(p); // { dg-error "no matching function" } std::unique_ptr<volatile A[]> vA3(p); // { dg-error "no matching function" } std::unique_ptr<const volatile A[]> cvA3(p); // { dg-error "no matching function" } - // { dg-error "no type" "" { target *-*-* } 448 } + // { dg-error "no type" "" { target *-*-* } 450 } } template<typename T> diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc new file mode 100644 index 00000000000..1a8f28838a1 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc @@ -0,0 +1,32 @@ +// Copyright (C) 2018 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 +// <http://www.gnu.org/licenses/>. + +// { dg-do compile { target c++11 } } + +#include <memory> + +struct Incomplete; + +void f(void** p) +{ + ::new (p[0]) std::unique_ptr<Incomplete>(); + ::new (p[1]) std::unique_ptr<Incomplete[]>(); + + // PR libstdc++/87704 + ::new (p[2]) std::unique_ptr<Incomplete>(nullptr); + ::new (p[3]) std::unique_ptr<Incomplete[]>(nullptr); +}
diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h index 0717c1e2728..dcb866d37bc 100644 --- a/libstdc++-v3/include/bits/unique_ptr.h +++ b/libstdc++-v3/include/bits/unique_ptr.h @@ -195,7 +195,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> constexpr unique_ptr() noexcept : _M_t() - { } + { } /** Takes ownership of a pointer. * @@ -244,7 +244,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION /// Creates a unique_ptr that owns nothing. template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> - constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { } + constexpr unique_ptr(nullptr_t) noexcept + : _M_t() + { } // Move constructors. @@ -472,7 +474,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> constexpr unique_ptr() noexcept : _M_t() - { } + { } /** Takes ownership of a pointer. * @@ -535,7 +537,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION /// Creates a unique_ptr that owns nothing. template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> - constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { } + constexpr unique_ptr(nullptr_t) noexcept + : _M_t() + { } template<typename _Up, typename _Ep, typename = _Require<__safe_conversion_up<_Up, _Ep>>> diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc new file mode 100644 index 00000000000..1a8f28838a1 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc @@ -0,0 +1,32 @@ +// Copyright (C) 2018 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 +// <http://www.gnu.org/licenses/>. + +// { dg-do compile { target c++11 } } + +#include <memory> + +struct Incomplete; + +void f(void** p) +{ + ::new (p[0]) std::unique_ptr<Incomplete>(); + ::new (p[1]) std::unique_ptr<Incomplete[]>(); + + // PR libstdc++/87704 + ::new (p[2]) std::unique_ptr<Incomplete>(nullptr); + ::new (p[3]) std::unique_ptr<Incomplete[]>(nullptr); +}
Using a delegating constructor to implement these constructors means that they instantiate the destructor, which requires the element_type to be complete. In C++11 and C++14 they were specified to be delegating, but that was changed as part of LWG 2801 so in C++17 they don't require a complete type (as was intended all along). PR libstdc++/87704 * include/bits/unique_ptr.h (unique_ptr::unique_ptr(nullptr_t)): Do not delegate to default constructor. (unique_ptr<T[], D>::unique_ptr(nullptr_t)): Likewise. * testsuite/20_util/unique_ptr/cons/incomplete.cc: New test. Tested powerpc64le-linux, committed to trunk. Backports to follow. commit 072315d496bd19a7227213b945652c984ddc4162 Author: Jonathan Wakely <jwakely@redhat.com> Date: Tue Oct 23 12:40:03 2018 +0100 PR libstdc++/87704 fix unique_ptr(nullptr_t) constructors Using a delegating constructor to implement these constructors means that they instantiate the destructor, which requires the element_type to be complete. In C++11 and C++14 they were specified to be delegating, but that was changed as part of LWG 2801 so in C++17 they don't require a complete type (as was intended all along). PR libstdc++/87704 * include/bits/unique_ptr.h (unique_ptr::unique_ptr(nullptr_t)): Do not delegate to default constructor. (unique_ptr<T[], D>::unique_ptr(nullptr_t)): Likewise. * testsuite/20_util/unique_ptr/cons/incomplete.cc: New test.