PR libstdc++/87855 fix optional for types with non-trivial copy/move
When the contained value is not trivially copy (or move) constructible the union's copy (or move) constructor will be deleted, and so the _Optional_payload delegating constructors are invalid. G++ fails to diagnose this because it incorrectly performs copy elision in the delegating constructors. Clang does diagnose it (llvm.org/PR40245). The solution is to avoid performing any copy (or move) when the contained value's copy (or move) constructor isn't trivial. Instead the contained value can be constructed by calling _M_construct. This is OK, because the relevant constructor doesn't need to be constexpr when the contained value isn't trivially copy (or move) constructible. Additionally, this patch removes a lot of code duplication in the _Optional_payload partial specializations and the _Optional_base partial specialization, by hoisting it into common base classes. The Python pretty printer for std::optional needs to be adjusted to support the new layout. Retain support for the old layout, and add a test to verify that the support still works. PR libstdc++/87855 * include/std/optional (_Optional_payload_base): New class template for common code hoisted from _Optional_payload specializations. Use a template for the union, to allow a partial specialization for types with non-trivial destructors. Add constructors for in-place initialization to the union. (_Optional_payload(bool, const _Optional_payload&)): Use _M_construct to perform non-trivial copy construction, instead of relying on non-standard copy elision in a delegating constructor. (_Optional_payload(bool, _Optional_payload&&)): Likewise for non-trivial move construction. (_Optional_payload): Derive from _Optional_payload_base and use it for everything except the non-trivial assignment operators, which are defined as needed. (_Optional_payload<false, C, M>): Derive from the specialization _Optional_payload<true, false, false> and add a destructor. (_Optional_base_impl::_M_destruct, _Optional_base_impl::_M_reset): Forward to corresponding members of _Optional_payload. (_Optional_base_impl::_M_is_engaged, _Optional_base_impl::_M_get): Hoist common members from _Optional_base. (_Optional_base): Make all members and base class public. (_Optional_base::_M_get, _Optional_base::_M_is_engaged): Move to _Optional_base_impl. * python/libstdcxx/v6/printers.py (StdExpOptionalPrinter): Add support for new std::optional layout. * testsuite/libstdc++-prettyprinters/compat.cc: New test. From-SVN: r267742
This commit is contained in:
Jonathan Wakely
Jonathan Wakely
parent
96e768c3fe
commit
d942bc80e4
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@ -1,5 +1,32 @@
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2019-01-08 Jonathan Wakely <jwakely@redhat.com>
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PR libstdc++/87855
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* include/std/optional (_Optional_payload_base): New class template
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for common code hoisted from _Optional_payload specializations. Use
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a template for the union, to allow a partial specialization for
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types with non-trivial destructors. Add constructors for in-place
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initialization to the union.
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(_Optional_payload(bool, const _Optional_payload&)): Use _M_construct
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to perform non-trivial copy construction, instead of relying on
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non-standard copy elision in a delegating constructor.
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(_Optional_payload(bool, _Optional_payload&&)): Likewise for
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non-trivial move construction.
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(_Optional_payload): Derive from _Optional_payload_base and use it
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for everything except the non-trivial assignment operators, which are
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defined as needed.
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(_Optional_payload<false, C, M>): Derive from the specialization
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_Optional_payload<true, false, false> and add a destructor.
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(_Optional_base_impl::_M_destruct, _Optional_base_impl::_M_reset):
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Forward to corresponding members of _Optional_payload.
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(_Optional_base_impl::_M_is_engaged, _Optional_base_impl::_M_get):
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Hoist common members from _Optional_base.
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(_Optional_base): Make all members and base class public.
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(_Optional_base::_M_get, _Optional_base::_M_is_engaged): Move to
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_Optional_base_impl.
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* python/libstdcxx/v6/printers.py (StdExpOptionalPrinter): Add
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support for new std::optional layout.
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* testsuite/libstdc++-prettyprinters/compat.cc: New test.
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PR libstdc++/88066
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* include/bits/locale_conv.h: Use <> for includes not "".
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* include/ext/random: Likewise.
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@ -98,8 +98,155 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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__throw_bad_optional_access()
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{ _GLIBCXX_THROW_OR_ABORT(bad_optional_access()); }
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// This class template manages construction/destruction of
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// the contained value for a std::optional.
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template <typename _Tp>
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struct _Optional_payload_base
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{
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using _Stored_type = remove_const_t<_Tp>;
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// Payload for optionals with non-trivial destructor.
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_Optional_payload_base() = default;
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~_Optional_payload_base() = default;
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template<typename... _Args>
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constexpr
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_Optional_payload_base(in_place_t __tag, _Args&&... __args)
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: _M_payload(__tag, std::forward<_Args>(__args)...),
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_M_engaged(true)
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{ }
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template<typename _Up, typename... _Args>
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constexpr
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_Optional_payload_base(std::initializer_list<_Up> __il,
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_Args&&... __args)
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: _M_payload(__il, std::forward<_Args>(__args)...),
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_M_engaged(true)
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{ }
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// Constructor used by _Optional_base copy constructor when the
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// contained value is not trivially copy constructible.
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constexpr
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_Optional_payload_base(bool __engaged,
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const _Optional_payload_base& __other)
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{
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if (__other._M_engaged)
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this->_M_construct(__other._M_get());
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}
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// Constructor used by _Optional_base move constructor when the
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// contained value is not trivially move constructible.
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constexpr
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_Optional_payload_base(bool __engaged,
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_Optional_payload_base&& __other)
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{
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if (__other._M_engaged)
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this->_M_construct(std::move(__other._M_get()));
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}
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// Copy constructor is only used to when the contained value is
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// trivially copy constructible.
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_Optional_payload_base(const _Optional_payload_base&) = default;
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// Move constructor is only used to when the contained value is
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// trivially copy constructible.
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_Optional_payload_base(_Optional_payload_base&&) = default;
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_Optional_payload_base&
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operator=(const _Optional_payload_base&) = default;
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_Optional_payload_base&
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operator=(_Optional_payload_base&&) = default;
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struct _Empty_byte { };
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template<typename _Up, bool = is_trivially_destructible_v<_Up>>
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union _Storage
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{
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constexpr _Storage() noexcept : _M_empty() { }
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template<typename... _Args>
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constexpr
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_Storage(in_place_t, _Args&&... __args)
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: _M_value(std::forward<_Args>(__args)...)
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{ }
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template<typename _Vp, typename... _Args>
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constexpr
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_Storage(std::initializer_list<_Vp> __il, _Args&&... __args)
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: _M_value(__il, std::forward<_Args>(__args)...)
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{ }
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_Empty_byte _M_empty;
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_Up _M_value;
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};
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template<typename _Up>
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union _Storage<_Up, false>
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{
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constexpr _Storage() noexcept : _M_empty() { }
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template<typename... _Args>
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constexpr
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_Storage(in_place_t, _Args&&... __args)
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: _M_value(std::forward<_Args>(__args)...)
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{ }
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template<typename _Vp, typename... _Args>
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constexpr
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_Storage(std::initializer_list<_Vp> __il, _Args&&... __args)
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: _M_value(__il, std::forward<_Args>(__args)...)
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{ }
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// User-provided destructor is needed when _Up has non-trivial dtor.
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~_Storage() { }
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_Empty_byte _M_empty;
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_Up _M_value;
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};
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_Storage<_Stored_type> _M_payload;
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bool _M_engaged = false;
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template<typename... _Args>
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void
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_M_construct(_Args&&... __args)
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noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
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{
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::new ((void *) std::__addressof(this->_M_payload))
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_Stored_type(std::forward<_Args>(__args)...);
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this->_M_engaged = true;
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}
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constexpr void
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_M_destroy() noexcept
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{
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_M_engaged = false;
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_M_payload._M_value.~_Stored_type();
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}
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// The _M_get() operations have _M_engaged as a precondition.
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// They exist to access the contained value with the appropriate
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// const-qualification, because _M_payload has had the const removed.
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constexpr _Tp&
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_M_get() noexcept
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{ return this->_M_payload._M_value; }
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constexpr const _Tp&
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_M_get() const noexcept
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{ return this->_M_payload._M_value; }
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// _M_reset is a 'safe' operation with no precondition.
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constexpr void
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_M_reset() noexcept
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{
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if (this->_M_engaged)
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_M_destroy();
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}
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};
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// Class template that manages the payload for optionals.
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template <typename _Tp,
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bool /*_HasTrivialDestructor*/ =
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is_trivially_destructible_v<_Tp>,
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@ -109,248 +256,32 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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bool /*_HasTrivialMove */ =
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is_trivially_move_assignable_v<_Tp>
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&& is_trivially_move_constructible_v<_Tp>>
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struct _Optional_payload
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{
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constexpr _Optional_payload() noexcept : _M_empty() { }
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struct _Optional_payload;
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template <typename... _Args>
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constexpr
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_Optional_payload(in_place_t, _Args&&... __args)
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: _M_payload(std::forward<_Args>(__args)...), _M_engaged(true) { }
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template<typename _Up, typename... _Args>
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constexpr
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_Optional_payload(std::initializer_list<_Up> __il,
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_Args&&... __args)
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: _M_payload(__il, std::forward<_Args>(__args)...),
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_M_engaged(true)
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{ }
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constexpr
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_Optional_payload(bool __engaged, const _Optional_payload& __other)
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: _Optional_payload(__other)
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{ }
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constexpr
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_Optional_payload(bool __engaged, _Optional_payload&& __other)
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: _Optional_payload(std::move(__other))
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{ }
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constexpr
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_Optional_payload(const _Optional_payload& __other)
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{
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if (__other._M_engaged)
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this->_M_construct(__other._M_payload);
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}
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constexpr
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_Optional_payload(_Optional_payload&& __other)
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{
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if (__other._M_engaged)
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this->_M_construct(std::move(__other._M_payload));
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}
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constexpr
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_Optional_payload&
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operator=(const _Optional_payload& __other)
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{
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if (this->_M_engaged && __other._M_engaged)
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this->_M_get() = __other._M_get();
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else
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{
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if (__other._M_engaged)
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this->_M_construct(__other._M_get());
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else
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this->_M_reset();
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}
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return *this;
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}
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constexpr
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_Optional_payload&
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operator=(_Optional_payload&& __other)
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noexcept(__and_v<is_nothrow_move_constructible<_Tp>,
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is_nothrow_move_assignable<_Tp>>)
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{
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if (this->_M_engaged && __other._M_engaged)
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this->_M_get() = std::move(__other._M_get());
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else
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{
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if (__other._M_engaged)
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this->_M_construct(std::move(__other._M_get()));
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else
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this->_M_reset();
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}
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return *this;
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}
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using _Stored_type = remove_const_t<_Tp>;
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struct _Empty_byte { };
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union {
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_Empty_byte _M_empty;
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_Stored_type _M_payload;
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};
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bool _M_engaged = false;
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~_Optional_payload()
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{
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if (_M_engaged)
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_M_payload.~_Stored_type();
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}
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template<typename... _Args>
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void
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_M_construct(_Args&&... __args)
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noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
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{
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::new ((void *) std::__addressof(this->_M_payload))
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_Stored_type(std::forward<_Args>(__args)...);
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this->_M_engaged = true;
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}
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// The _M_get operations have _M_engaged as a precondition.
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constexpr _Tp&
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_M_get() noexcept
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{ return this->_M_payload; }
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constexpr const _Tp&
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_M_get() const noexcept
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{ return this->_M_payload; }
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// _M_reset is a 'safe' operation with no precondition.
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constexpr
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void
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_M_reset() noexcept
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{
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if (this->_M_engaged)
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{
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this->_M_engaged = false;
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this->_M_payload.~_Stored_type();
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}
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}
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};
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// Payload for potentially-constexpr optionals.
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// Payload for potentially-constexpr optionals (trivial copy/move/destroy).
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template <typename _Tp>
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struct _Optional_payload<_Tp, true, true, true>
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: _Optional_payload_base<_Tp>
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{
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constexpr _Optional_payload() noexcept
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: _M_empty(), _M_engaged(false) { }
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using _Optional_payload_base<_Tp>::_Optional_payload_base;
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template<typename... _Args>
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constexpr
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_Optional_payload(in_place_t, _Args&&... __args)
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: _M_payload(std::forward<_Args>(__args)...), _M_engaged(true)
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{ }
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template<typename _Up, typename... _Args>
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constexpr
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_Optional_payload(std::initializer_list<_Up> __il,
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_Args&&... __args)
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: _M_payload(__il, std::forward<_Args>(__args)...),
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_M_engaged(true)
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{ }
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template <class _Up> struct __ctor_tag {};
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constexpr
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_Optional_payload(__ctor_tag<bool>, const _Tp& __other)
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: _M_payload(__other), _M_engaged(true)
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{ }
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constexpr _Optional_payload(__ctor_tag<void>) noexcept
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: _M_empty(), _M_engaged(false)
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{ }
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constexpr _Optional_payload(__ctor_tag<bool>, _Tp&& __other)
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: _M_payload(std::move(__other)), _M_engaged(true)
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{ }
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constexpr
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_Optional_payload(bool __engaged, const _Optional_payload& __other)
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: _Optional_payload(__engaged ?
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_Optional_payload(__ctor_tag<bool>{},
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__other._M_payload) :
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_Optional_payload(__ctor_tag<void>{}))
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{ }
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constexpr
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_Optional_payload(bool __engaged, _Optional_payload&& __other)
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: _Optional_payload(__engaged
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? _Optional_payload(__ctor_tag<bool>{},
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std::move(__other._M_payload))
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: _Optional_payload(__ctor_tag<void>{}))
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{ }
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using _Stored_type = remove_const_t<_Tp>;
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struct _Empty_byte { };
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union {
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_Empty_byte _M_empty;
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_Stored_type _M_payload;
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};
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bool _M_engaged;
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_Optional_payload() = default;
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};
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// Payload for optionals with non-trivial copy assignment.
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// Payload for optionals with non-trivial copy construction/assignment.
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template <typename _Tp>
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struct _Optional_payload<_Tp, true, false, true>
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: _Optional_payload_base<_Tp>
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{
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constexpr _Optional_payload() noexcept
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: _M_empty(), _M_engaged(false) { }
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template<typename... _Args>
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constexpr
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_Optional_payload(in_place_t, _Args&&... __args)
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: _M_payload(std::forward<_Args>(__args)...), _M_engaged(true)
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{ }
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template<typename _Up, typename... _Args>
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constexpr
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_Optional_payload(std::initializer_list<_Up> __il,
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_Args&&... __args)
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: _M_payload(__il, std::forward<_Args>(__args)...),
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_M_engaged(true)
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{ }
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template <class _Up> struct __ctor_tag {};
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constexpr _Optional_payload(__ctor_tag<bool>, const _Tp& __other)
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: _M_payload(__other),
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_M_engaged(true)
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{ }
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constexpr _Optional_payload(__ctor_tag<void>) noexcept
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: _M_empty(), _M_engaged(false)
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{ }
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constexpr _Optional_payload(__ctor_tag<bool>, _Tp&& __other)
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: _M_payload(std::move(__other)),
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_M_engaged(true)
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{ }
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constexpr
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_Optional_payload(bool __engaged, const _Optional_payload& __other)
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: _Optional_payload(__engaged ?
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_Optional_payload(__ctor_tag<bool>{},
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__other._M_payload) :
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_Optional_payload(__ctor_tag<void>{}))
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{ }
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constexpr
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_Optional_payload(bool __engaged, _Optional_payload&& __other)
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: _Optional_payload(__engaged
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? _Optional_payload(__ctor_tag<bool>{},
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std::move(__other._M_payload))
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: _Optional_payload(__ctor_tag<void>{}))
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{ }
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using _Optional_payload_base<_Tp>::_Optional_payload_base;
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_Optional_payload() = default;
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~_Optional_payload() = default;
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_Optional_payload(const _Optional_payload&) = default;
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_Optional_payload(_Optional_payload&&) = default;
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_Optional_payload& operator=(_Optional_payload&&) = default;
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// Non-trivial copy assignment.
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constexpr
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_Optional_payload&
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operator=(const _Optional_payload& __other)
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||||
|
|
@ -366,113 +297,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
}
|
||||
return *this;
|
||||
}
|
||||
|
||||
_Optional_payload&
|
||||
operator=(_Optional_payload&& __other) = default;
|
||||
|
||||
using _Stored_type = remove_const_t<_Tp>;
|
||||
|
||||
struct _Empty_byte { };
|
||||
|
||||
union {
|
||||
_Empty_byte _M_empty;
|
||||
_Stored_type _M_payload;
|
||||
};
|
||||
bool _M_engaged;
|
||||
|
||||
template<typename... _Args>
|
||||
void
|
||||
_M_construct(_Args&&... __args)
|
||||
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
|
||||
{
|
||||
::new ((void *) std::__addressof(this->_M_payload))
|
||||
_Stored_type(std::forward<_Args>(__args)...);
|
||||
this->_M_engaged = true;
|
||||
}
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{ return this->_M_payload; }
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{ return this->_M_payload; }
|
||||
|
||||
// _M_reset is a 'safe' operation with no precondition.
|
||||
constexpr
|
||||
void
|
||||
_M_reset() noexcept
|
||||
{
|
||||
if (this->_M_engaged)
|
||||
{
|
||||
this->_M_engaged = false;
|
||||
this->_M_payload.~_Stored_type();
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
// Payload for optionals with non-trivial move assignment.
|
||||
// Payload for optionals with non-trivial move construction/assignment.
|
||||
template <typename _Tp>
|
||||
struct _Optional_payload<_Tp, true, true, false>
|
||||
: _Optional_payload_base<_Tp>
|
||||
{
|
||||
constexpr _Optional_payload() noexcept
|
||||
: _M_empty(), _M_engaged(false) { }
|
||||
|
||||
template<typename... _Args>
|
||||
constexpr
|
||||
_Optional_payload(in_place_t, _Args&&... __args)
|
||||
: _M_payload(std::forward<_Args>(__args)...),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
template<typename _Up, typename... _Args>
|
||||
constexpr
|
||||
_Optional_payload(std::initializer_list<_Up> __il,
|
||||
_Args&&... __args)
|
||||
: _M_payload(__il, std::forward<_Args>(__args)...),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
template <class _Up> struct __ctor_tag {};
|
||||
|
||||
constexpr
|
||||
_Optional_payload(__ctor_tag<bool>, const _Tp& __other)
|
||||
: _M_payload(__other),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
constexpr _Optional_payload(__ctor_tag<void>) noexcept
|
||||
: _M_empty(), _M_engaged(false)
|
||||
{ }
|
||||
|
||||
constexpr _Optional_payload(__ctor_tag<bool>, _Tp&& __other)
|
||||
: _M_payload(std::move(__other)),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
constexpr
|
||||
_Optional_payload(bool __engaged, const _Optional_payload& __other)
|
||||
: _Optional_payload(__engaged ?
|
||||
_Optional_payload(__ctor_tag<bool>{},
|
||||
__other._M_payload) :
|
||||
_Optional_payload(__ctor_tag<void>{}))
|
||||
{ }
|
||||
|
||||
constexpr
|
||||
_Optional_payload(bool __engaged, _Optional_payload&& __other)
|
||||
: _Optional_payload(__engaged
|
||||
? _Optional_payload(__ctor_tag<bool>{},
|
||||
std::move(__other._M_payload))
|
||||
: _Optional_payload(__ctor_tag<void>{}))
|
||||
{ }
|
||||
using _Optional_payload_base<_Tp>::_Optional_payload_base;
|
||||
|
||||
_Optional_payload() = default;
|
||||
~_Optional_payload() = default;
|
||||
_Optional_payload(const _Optional_payload&) = default;
|
||||
_Optional_payload(_Optional_payload&&) = default;
|
||||
_Optional_payload& operator=(const _Optional_payload&) = default;
|
||||
|
||||
_Optional_payload&
|
||||
operator=(const _Optional_payload& __other) = default;
|
||||
|
||||
// Non-trivial move assignment.
|
||||
constexpr
|
||||
_Optional_payload&
|
||||
operator=(_Optional_payload&& __other)
|
||||
|
|
@ -490,106 +330,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
}
|
||||
return *this;
|
||||
}
|
||||
|
||||
using _Stored_type = remove_const_t<_Tp>;
|
||||
|
||||
struct _Empty_byte { };
|
||||
|
||||
union {
|
||||
_Empty_byte _M_empty;
|
||||
_Stored_type _M_payload;
|
||||
};
|
||||
bool _M_engaged;
|
||||
|
||||
template<typename... _Args>
|
||||
void
|
||||
_M_construct(_Args&&... __args)
|
||||
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
|
||||
{
|
||||
::new ((void *) std::__addressof(this->_M_payload))
|
||||
_Stored_type(std::forward<_Args>(__args)...);
|
||||
this->_M_engaged = true;
|
||||
}
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{ return this->_M_payload; }
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{ return this->_M_payload; }
|
||||
|
||||
// _M_reset is a 'safe' operation with no precondition.
|
||||
constexpr
|
||||
void
|
||||
_M_reset() noexcept
|
||||
{
|
||||
if (this->_M_engaged)
|
||||
{
|
||||
this->_M_engaged = false;
|
||||
this->_M_payload.~_Stored_type();
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
// Payload for optionals with non-trivial copy and move assignment.
|
||||
template <typename _Tp>
|
||||
struct _Optional_payload<_Tp, true, false, false>
|
||||
: _Optional_payload_base<_Tp>
|
||||
{
|
||||
constexpr _Optional_payload() noexcept
|
||||
: _M_empty(), _M_engaged(false) {}
|
||||
|
||||
template<typename... _Args>
|
||||
constexpr
|
||||
_Optional_payload(in_place_t, _Args&&... __args)
|
||||
: _M_payload(std::forward<_Args>(__args)...),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
template<typename _Up, typename... _Args>
|
||||
constexpr
|
||||
_Optional_payload(std::initializer_list<_Up> __il,
|
||||
_Args&&... __args)
|
||||
: _M_payload(__il, std::forward<_Args>(__args)...),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
template <class _Up> struct __ctor_tag {};
|
||||
|
||||
constexpr _Optional_payload(__ctor_tag<bool>, const _Tp& __other)
|
||||
: _M_payload(__other),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
constexpr _Optional_payload(__ctor_tag<void>) noexcept
|
||||
: _M_empty(), _M_engaged(false)
|
||||
{ }
|
||||
|
||||
constexpr _Optional_payload(__ctor_tag<bool>, _Tp&& __other)
|
||||
: _M_payload(std::move(__other)),
|
||||
_M_engaged(true)
|
||||
{ }
|
||||
|
||||
constexpr
|
||||
_Optional_payload(bool __engaged, const _Optional_payload& __other)
|
||||
: _Optional_payload(__engaged ?
|
||||
_Optional_payload(__ctor_tag<bool>{},
|
||||
__other._M_payload) :
|
||||
_Optional_payload(__ctor_tag<void>{}))
|
||||
{ }
|
||||
|
||||
constexpr
|
||||
_Optional_payload(bool __engaged, _Optional_payload&& __other)
|
||||
: _Optional_payload(__engaged
|
||||
? _Optional_payload(__ctor_tag<bool>{},
|
||||
std::move(__other._M_payload))
|
||||
: _Optional_payload(__ctor_tag<void>{}))
|
||||
{ }
|
||||
using _Optional_payload_base<_Tp>::_Optional_payload_base;
|
||||
|
||||
_Optional_payload() = default;
|
||||
~_Optional_payload() = default;
|
||||
_Optional_payload(const _Optional_payload&) = default;
|
||||
_Optional_payload(_Optional_payload&&) = default;
|
||||
|
||||
// Non-trivial copy
|
||||
constexpr
|
||||
_Optional_payload&
|
||||
operator=(const _Optional_payload& __other)
|
||||
|
|
@ -606,6 +361,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
return *this;
|
||||
}
|
||||
|
||||
// Non-trivial move assignment.
|
||||
constexpr
|
||||
_Optional_payload&
|
||||
operator=(_Optional_payload&& __other)
|
||||
|
|
@ -623,50 +379,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
}
|
||||
return *this;
|
||||
}
|
||||
|
||||
using _Stored_type = remove_const_t<_Tp>;
|
||||
|
||||
struct _Empty_byte { };
|
||||
|
||||
union {
|
||||
_Empty_byte _M_empty;
|
||||
_Stored_type _M_payload;
|
||||
};
|
||||
bool _M_engaged;
|
||||
|
||||
template<typename... _Args>
|
||||
constexpr
|
||||
void
|
||||
_M_construct(_Args&&... __args)
|
||||
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
|
||||
{
|
||||
::new ((void *) std::__addressof(this->_M_payload))
|
||||
_Stored_type(std::forward<_Args>(__args)...);
|
||||
this->_M_engaged = true;
|
||||
}
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{ return this->_M_payload; }
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{ return this->_M_payload; }
|
||||
|
||||
// _M_reset is a 'safe' operation with no precondition.
|
||||
constexpr
|
||||
void
|
||||
_M_reset() noexcept
|
||||
{
|
||||
if (this->_M_engaged)
|
||||
{
|
||||
this->_M_engaged = false;
|
||||
this->_M_payload.~_Stored_type();
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
// Payload for optionals with non-trivial destructors.
|
||||
template <typename _Tp, bool _Copy, bool _Move>
|
||||
struct _Optional_payload<_Tp, false, _Copy, _Move>
|
||||
: _Optional_payload<_Tp, true, false, false>
|
||||
{
|
||||
// Base class implements all the constructors and assignment operators:
|
||||
using _Optional_payload<_Tp, true, false, false>::_Optional_payload;
|
||||
_Optional_payload() = default;
|
||||
_Optional_payload(const _Optional_payload&) = default;
|
||||
_Optional_payload(_Optional_payload&&) = default;
|
||||
_Optional_payload& operator=(const _Optional_payload&) = default;
|
||||
_Optional_payload& operator=(_Optional_payload&&) = default;
|
||||
|
||||
// Destructor needs to destroy the contained value:
|
||||
~_Optional_payload() { this->_M_reset(); }
|
||||
};
|
||||
|
||||
// Common base class for _Optional_base<T> to avoid repeating these
|
||||
// member functions in each specialization.
|
||||
template<typename _Tp, typename _Dp>
|
||||
class _Optional_base_impl
|
||||
{
|
||||
|
|
@ -688,39 +421,56 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
|
||||
void
|
||||
_M_destruct() noexcept
|
||||
{
|
||||
static_cast<_Dp*>(this)->_M_payload._M_engaged = false;
|
||||
static_cast<_Dp*>(this)->_M_payload._M_payload.~_Stored_type();
|
||||
}
|
||||
{ static_cast<_Dp*>(this)->_M_payload._M_destroy(); }
|
||||
|
||||
// _M_reset is a 'safe' operation with no precondition.
|
||||
constexpr
|
||||
void
|
||||
constexpr void
|
||||
_M_reset() noexcept
|
||||
{ static_cast<_Dp*>(this)->_M_payload._M_reset(); }
|
||||
|
||||
constexpr bool _M_is_engaged() const noexcept
|
||||
{ return static_cast<const _Dp*>(this)->_M_payload._M_engaged; }
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{
|
||||
if (static_cast<_Dp*>(this)->_M_payload._M_engaged)
|
||||
static_cast<_Dp*>(this)->_M_destruct();
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return static_cast<_Dp*>(this)->_M_payload._M_get();
|
||||
}
|
||||
};
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return static_cast<const _Dp*>(this)->_M_payload._M_get();
|
||||
}
|
||||
};
|
||||
|
||||
/**
|
||||
* @brief Class template that takes care of copy/move constructors
|
||||
of optional
|
||||
* @brief Class template that provides copy/move constructors of optional.
|
||||
*
|
||||
* Such a separate base class template is necessary in order to
|
||||
* conditionally make copy/move constructors trivial.
|
||||
*
|
||||
* When the contained value is trivally copy/move constructible,
|
||||
* the copy/move constructors of _Optional_base will invoke the
|
||||
* trivial copy/move constructor of _Optional_payload. Otherwise,
|
||||
* they will invoke _Optional_payload(bool, const _Optional_payload&)
|
||||
* or _Optional_payload(bool, _Optional_payload&&) to initialize
|
||||
* the contained value, if copying/moving an engaged optional.
|
||||
*
|
||||
* Whether the other special members are trivial is determined by the
|
||||
* _Optional_payload<_Tp> specialization used for the _M_payload member.
|
||||
*
|
||||
* @see optional, _Enable_special_members
|
||||
*/
|
||||
template<typename _Tp,
|
||||
bool = is_trivially_copy_constructible_v<_Tp>,
|
||||
bool = is_trivially_move_constructible_v<_Tp>>
|
||||
class _Optional_base
|
||||
// protected inheritance because optional needs to reach that base too
|
||||
: protected _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
struct _Optional_base
|
||||
: _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
{
|
||||
friend class _Optional_base_impl<_Tp, _Optional_base<_Tp>>;
|
||||
|
||||
public:
|
||||
// Constructors for disengaged optionals.
|
||||
constexpr _Optional_base() = default;
|
||||
|
||||
|
|
@ -758,37 +508,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
_Optional_base& operator=(const _Optional_base&) = default;
|
||||
_Optional_base& operator=(_Optional_base&&) = default;
|
||||
|
||||
protected:
|
||||
|
||||
constexpr bool _M_is_engaged() const noexcept
|
||||
{ return this->_M_payload._M_engaged; }
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
private:
|
||||
_Optional_payload<_Tp> _M_payload;
|
||||
};
|
||||
|
||||
template<typename _Tp>
|
||||
class _Optional_base<_Tp, false, true>
|
||||
: protected _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
struct _Optional_base<_Tp, false, true>
|
||||
: _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
{
|
||||
friend class _Optional_base_impl<_Tp, _Optional_base<_Tp>>;
|
||||
public:
|
||||
|
||||
// Constructors for disengaged optionals.
|
||||
constexpr _Optional_base() = default;
|
||||
|
||||
|
|
@ -822,37 +548,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
_Optional_base& operator=(const _Optional_base&) = default;
|
||||
_Optional_base& operator=(_Optional_base&&) = default;
|
||||
|
||||
protected:
|
||||
|
||||
constexpr bool _M_is_engaged() const noexcept
|
||||
{ return this->_M_payload._M_engaged; }
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
private:
|
||||
_Optional_payload<_Tp> _M_payload;
|
||||
};
|
||||
|
||||
template<typename _Tp>
|
||||
class _Optional_base<_Tp, true, false>
|
||||
: protected _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
struct _Optional_base<_Tp, true, false>
|
||||
: _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
{
|
||||
friend class _Optional_base_impl<_Tp, _Optional_base<_Tp>>;
|
||||
public:
|
||||
|
||||
// Constructors for disengaged optionals.
|
||||
constexpr _Optional_base() = default;
|
||||
|
||||
|
|
@ -887,37 +589,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
_Optional_base& operator=(const _Optional_base&) = default;
|
||||
_Optional_base& operator=(_Optional_base&&) = default;
|
||||
|
||||
protected:
|
||||
|
||||
constexpr bool _M_is_engaged() const noexcept
|
||||
{ return this->_M_payload._M_engaged; }
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
private:
|
||||
_Optional_payload<_Tp> _M_payload;
|
||||
};
|
||||
|
||||
template<typename _Tp>
|
||||
class _Optional_base<_Tp, true, true>
|
||||
: protected _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
struct _Optional_base<_Tp, true, true>
|
||||
: _Optional_base_impl<_Tp, _Optional_base<_Tp>>
|
||||
{
|
||||
friend class _Optional_base_impl<_Tp, _Optional_base<_Tp>>;
|
||||
public:
|
||||
|
||||
// Constructors for disengaged optionals.
|
||||
constexpr _Optional_base() = default;
|
||||
|
||||
|
|
@ -947,27 +625,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
_Optional_base& operator=(const _Optional_base&) = default;
|
||||
_Optional_base& operator=(_Optional_base&&) = default;
|
||||
|
||||
protected:
|
||||
|
||||
constexpr bool _M_is_engaged() const noexcept
|
||||
{ return this->_M_payload._M_engaged; }
|
||||
|
||||
// The _M_get operations have _M_engaged as a precondition.
|
||||
constexpr _Tp&
|
||||
_M_get() noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
constexpr const _Tp&
|
||||
_M_get() const noexcept
|
||||
{
|
||||
__glibcxx_assert(this->_M_is_engaged());
|
||||
return this->_M_payload._M_payload;
|
||||
}
|
||||
|
||||
private:
|
||||
_Optional_payload<_Tp> _M_payload;
|
||||
};
|
||||
|
||||
|
|
@ -1262,36 +919,32 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
value() const&
|
||||
{
|
||||
return this->_M_is_engaged()
|
||||
? this->_M_get()
|
||||
: (__throw_bad_optional_access(),
|
||||
this->_M_get());
|
||||
? this->_M_get()
|
||||
: (__throw_bad_optional_access(), this->_M_get());
|
||||
}
|
||||
|
||||
constexpr _Tp&
|
||||
value()&
|
||||
{
|
||||
return this->_M_is_engaged()
|
||||
? this->_M_get()
|
||||
: (__throw_bad_optional_access(),
|
||||
this->_M_get());
|
||||
? this->_M_get()
|
||||
: (__throw_bad_optional_access(), this->_M_get());
|
||||
}
|
||||
|
||||
constexpr _Tp&&
|
||||
value()&&
|
||||
{
|
||||
return this->_M_is_engaged()
|
||||
? std::move(this->_M_get())
|
||||
: (__throw_bad_optional_access(),
|
||||
std::move(this->_M_get()));
|
||||
? std::move(this->_M_get())
|
||||
: (__throw_bad_optional_access(), std::move(this->_M_get()));
|
||||
}
|
||||
|
||||
constexpr const _Tp&&
|
||||
value() const&&
|
||||
{
|
||||
return this->_M_is_engaged()
|
||||
? std::move(this->_M_get())
|
||||
: (__throw_bad_optional_access(),
|
||||
std::move(this->_M_get()));
|
||||
? std::move(this->_M_get())
|
||||
: (__throw_bad_optional_access(), std::move(this->_M_get()));
|
||||
}
|
||||
|
||||
template<typename _Up>
|
||||
|
|
@ -1302,8 +955,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
static_assert(is_convertible_v<_Up&&, _Tp>);
|
||||
|
||||
return this->_M_is_engaged()
|
||||
? this->_M_get()
|
||||
: static_cast<_Tp>(std::forward<_Up>(__u));
|
||||
? this->_M_get() : static_cast<_Tp>(std::forward<_Up>(__u));
|
||||
}
|
||||
|
||||
template<typename _Up>
|
||||
|
|
|
|||
|
|
@ -1093,13 +1093,23 @@ class StdExpOptionalPrinter(SingleObjContainerPrinter):
|
|||
|
||||
def __init__ (self, typename, val):
|
||||
valtype = self._recognize (val.type.template_argument(0))
|
||||
self.typename = strip_versioned_namespace(typename)
|
||||
self.typename = re.sub('^std::(experimental::|)(fundamentals_v\d::|)(.*)', r'std::\1\3<%s>' % valtype, self.typename, 1)
|
||||
if not self.typename.startswith('std::experimental'):
|
||||
val = val['_M_payload']
|
||||
self.val = val
|
||||
contained_value = val['_M_payload'] if self.val['_M_engaged'] else None
|
||||
visualizer = gdb.default_visualizer (val['_M_payload'])
|
||||
typename = strip_versioned_namespace(typename)
|
||||
self.typename = re.sub('^std::(experimental::|)(fundamentals_v\d::|)(.*)', r'std::\1\3<%s>' % valtype, typename, 1)
|
||||
payload = val['_M_payload']
|
||||
if self.typename.startswith('std::experimental'):
|
||||
engaged = val['_M_engaged']
|
||||
contained_value = payload
|
||||
else:
|
||||
engaged = payload['_M_engaged']
|
||||
contained_value = payload['_M_payload']
|
||||
try:
|
||||
# Since GCC 9
|
||||
contained_value = contained_value['_M_value']
|
||||
except:
|
||||
pass
|
||||
visualizer = gdb.default_visualizer (contained_value)
|
||||
if not engaged:
|
||||
contained_value = None
|
||||
super (StdExpOptionalPrinter, self).__init__ (contained_value, visualizer)
|
||||
|
||||
def to_string (self):
|
||||
|
|
|
|||
|
|
@ -0,0 +1,76 @@
|
|||
// { dg-options "-g -O0" }
|
||||
// { dg-do run }
|
||||
// { dg-skip-if "" { *-*-* } { "-D_GLIBCXX_PROFILE" } }
|
||||
|
||||
// Copyright (C) 2014-2019 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
|
||||
// <http://www.gnu.org/licenses/>.
|
||||
|
||||
// Test that current printers still support old definitions of types.
|
||||
|
||||
namespace std
|
||||
{
|
||||
// Old representation of std::optional, before GCC 9
|
||||
template<typename T>
|
||||
struct _Optional_payload
|
||||
{
|
||||
_Optional_payload() : _M_empty(), _M_engaged(false) { }
|
||||
struct _Empty_byte { };
|
||||
union {
|
||||
_Empty_byte _M_empty;
|
||||
T _M_payload;
|
||||
};
|
||||
bool _M_engaged;
|
||||
};
|
||||
|
||||
template<typename T>
|
||||
struct _Optional_base
|
||||
{
|
||||
_Optional_payload<T> _M_payload;
|
||||
};
|
||||
|
||||
template<typename T>
|
||||
struct optional : _Optional_base<T>
|
||||
{
|
||||
optional() { }
|
||||
|
||||
optional(T t)
|
||||
{
|
||||
this->_M_payload._M_payload = t;
|
||||
this->_M_payload._M_engaged = true;
|
||||
}
|
||||
};
|
||||
} // namespace std
|
||||
|
||||
int
|
||||
main()
|
||||
{
|
||||
using std::optional;
|
||||
|
||||
optional<int> o;
|
||||
// { dg-final { note-test o {std::optional<int> [no contained value]} } }
|
||||
optional<bool> ob{false};
|
||||
// { dg-final { note-test ob {std::optional<bool> = {[contained value] = false}} } }
|
||||
optional<int> oi{5};
|
||||
// { dg-final { note-test oi {std::optional<int> = {[contained value] = 5}} } }
|
||||
optional<void*> op{nullptr};
|
||||
// { dg-final { note-test op {std::optional<void *> = {[contained value] = 0x0}} } }
|
||||
|
||||
__builtin_puts("");
|
||||
return 0; // Mark SPOT
|
||||
}
|
||||
|
||||
// { dg-final { gdb-test SPOT } }
|
||||
Loading…
Reference in New Issue