From: Jonathan Wakely Date: Fri, 10 May 2019 21:41:16 +0000 (+0100) Subject: PR libstdc++/90388 fix std::hash> bugs X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7fb65a875956bac7095c17c545f2bfa131209f50;p=gcc.git PR libstdc++/90388 fix std::hash> bugs A disabled specialization should not be callable, so move the function call operator into a new base class which correctly implements the disabled hash semantics. For the versioned namespace configuration do not derive from __poison_hash in the enabled case, as the empty base class serves no purpose but potentially increases the object size. For the default configuration that base class must be kept, to preserve layout. An enabled specialization should not be unconditionally noexcept, because the underlying hash object might throw. PR libstdc++/90388 * include/bits/unique_ptr.h (default_delete, default_delete): Use _Require for constraints. (operator>(nullptr_t, const unique_ptr&)): Implement exactly as per the standard. (__uniq_ptr_hash): New base class with conditionally-disabled call operator. (hash>): Derive from __uniq_ptr_hash. * testsuite/20_util/default_delete/48631_neg.cc: Adjust dg-error line. * testsuite/20_util/unique_ptr/hash/90388.cc: New test. From-SVN: r271078 --- diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 77a83d273af..c37cab49396 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,16 @@ 2019-05-10 Jonathan Wakely + PR libstdc++/90388 + * include/bits/unique_ptr.h (default_delete, default_delete): + Use _Require for constraints. + (operator>(nullptr_t, const unique_ptr&)): Implement exactly as + per the standard. + (__uniq_ptr_hash): New base class with conditionally-disabled call + operator. + (hash>): Derive from __uniq_ptr_hash. + * testsuite/20_util/default_delete/48631_neg.cc: Adjust dg-error line. + * testsuite/20_util/unique_ptr/hash/90388.cc: New test. + * include/bits/shared_ptr.h: Improve docs. * include/bits/shared_ptr_base.h: Likewise. * include/bits/stl_uninitialized.h: Likewise. diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h index 6a23669f119..a9e74725dfd 100644 --- a/libstdc++-v3/include/bits/unique_ptr.h +++ b/libstdc++-v3/include/bits/unique_ptr.h @@ -66,8 +66,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION * Allows conversion from a deleter for objects of another type, `_Up`, * only if `_Up*` is convertible to `_Tp*`. */ - template::value>::type> + template>> default_delete(const default_delete<_Up>&) noexcept { } /// Calls `delete __ptr` @@ -102,19 +102,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION * it is undefined to `delete[]` an array of derived types through a * pointer to the base type. */ - template::value>::type> + template>> default_delete(const default_delete<_Up[]>&) noexcept { } /// Calls `delete[] __ptr` template - typename enable_if::value>::type + typename enable_if::value>::type operator()(_Up* __ptr) const - { - static_assert(sizeof(_Tp)>0, - "can't delete pointer to incomplete type"); - delete [] __ptr; - } + { + static_assert(sizeof(_Tp)>0, + "can't delete pointer to incomplete type"); + delete [] __ptr; + } }; /// @cond undocumented @@ -712,7 +712,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION unique_ptr<_Tp, _Dp>&) = delete; #endif - /// Equality operator for unique_ptr objects, compares the owned pointers. + /// Equality operator for unique_ptr objects, compares the owned pointers template _GLIBCXX_NODISCARD inline bool @@ -848,23 +848,37 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _GLIBCXX_NODISCARD inline bool operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) { return !(nullptr < __x); } + // @} relates unique_ptr + + /// @cond undocumented + template::__enable_hash_call> + struct __uniq_ptr_hash +#if ! _GLIBCXX_INLINE_VERSION + : private __poison_hash<_Ptr> +#endif + { + size_t + operator()(const _Up& __u) const + noexcept(noexcept(std::declval>()(std::declval<_Ptr>()))) + { return hash<_Ptr>()(__u.get()); } + }; + + template + struct __uniq_ptr_hash<_Up, _Ptr, false> + : private __poison_hash<_Ptr> + { }; + /// @endcond /// std::hash specialization for unique_ptr. template struct hash> : public __hash_base>, - private __poison_hash::pointer> - { - size_t - operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept - { - typedef unique_ptr<_Tp, _Dp> _UP; - return std::hash()(__u.get()); - } - }; + public __uniq_ptr_hash> + { }; #if __cplusplus > 201103L - + /// @relates unique_ptr @{ #define __cpp_lib_make_unique 201304 /// @cond undocumented @@ -899,9 +913,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template inline typename _MakeUniq<_Tp>::__invalid_type make_unique(_Args&&...) = delete; + // @} relates unique_ptr #endif - // @} relates unique_ptr // @} group pointer_abstractions #if __cplusplus >= 201703L diff --git a/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc b/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc index bd81913c651..111a42434db 100644 --- a/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc +++ b/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc @@ -26,4 +26,4 @@ struct D : B { }; D d; std::default_delete db; typedef decltype(db(&d)) type; // { dg-error "no match" } -// { dg-error "no type" "" { target *-*-* } 111 } +// { dg-error "no type" "" { target *-*-* } 112 } diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/hash/90388.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/hash/90388.cc new file mode 100644 index 00000000000..0f3b7857797 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/unique_ptr/hash/90388.cc @@ -0,0 +1,90 @@ +// Copyright (C) 2019 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-do run { target c++11 } } + +#include + +template + struct is_callable + : std::false_type + { }; + +template + struct is_callable()(std::declval())))> + : std::true_type + { }; + +void +test01() +{ + struct D { + struct pointer { }; + void operator()(pointer) const noexcept { } + }; + static_assert( !is_callable&, D::pointer>::value ); + + using UP = std::unique_ptr; + // [unord.hash] + // Disabled specializations of hash are not function object types + static_assert( !is_callable&, UP>::value ); + static_assert( !is_callable&, UP&>::value ); + static_assert( !is_callable&, const UP&>::value ); +} + +struct D { + struct pointer { }; + void operator()(pointer) const noexcept { } +}; + +bool operator==(D::pointer, std::nullptr_t) { return false; } +bool operator!=(D::pointer, std::nullptr_t) { return true; } + +namespace std { + template<> struct hash { + size_t operator()(D::pointer) const { throw 1; } + }; +} + +void +test02() +{ + using UP = std::unique_ptr; + UP p; + std::hash h; + try { + // [util.smartptr.hash] + // The member functions are not guaranteed to be noexcept. + h(p); + throw "should not reach here"; + } catch (int) { + // Should catch exception here, rather than terminating. + } + + // Should still be noexcept if the underlying hash object is: + using UP2 = std::unique_ptr; + UP2 p2; + std::hash h2; + static_assert( noexcept(h2(p2)), "operator() is noexcept" ); +} + +int +main() +{ + test02(); +}