// -*- C++ -*- //===----------------------------------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H #define _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H #include <__algorithm/copy.h> #include <__algorithm/move.h> #include <__algorithm/unwrap_iter.h> #include <__algorithm/unwrap_range.h> #include <__config> #include <__iterator/iterator_traits.h> #include <__iterator/reverse_iterator.h> #include <__memory/addressof.h> #include <__memory/allocator_traits.h> #include <__memory/construct_at.h> #include <__memory/pointer_traits.h> #include <__memory/voidify.h> #include <__type_traits/extent.h> #include <__type_traits/is_array.h> #include <__type_traits/is_constant_evaluated.h> #include <__type_traits/is_trivially_assignable.h> #include <__type_traits/is_trivially_constructible.h> #include <__type_traits/is_trivially_relocatable.h> #include <__type_traits/is_unbounded_array.h> #include <__type_traits/negation.h> #include <__type_traits/remove_const.h> #include <__type_traits/remove_extent.h> #include <__utility/exception_guard.h> #include <__utility/move.h> #include <__utility/pair.h> #include #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) # pragma GCC system_header #endif _LIBCPP_PUSH_MACROS #include <__undef_macros> _LIBCPP_BEGIN_NAMESPACE_STD struct __always_false { template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool operator()(_Args&&...) const _NOEXCEPT { return false; } }; // uninitialized_copy template inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_copy( _InputIterator __ifirst, _Sentinel1 __ilast, _ForwardIterator __ofirst, _EndPredicate __stop_copying) { _ForwardIterator __idx = __ofirst; #ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { #endif for (; __ifirst != __ilast && !__stop_copying(__idx); ++__ifirst, (void)++__idx) ::new (std::__voidify(*__idx)) _ValueType(*__ifirst); #ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__ofirst, __idx); throw; } #endif return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx)); } template _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_copy(_InputIterator __ifirst, _InputIterator __ilast, _ForwardIterator __ofirst) { typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType; auto __result = std::__uninitialized_copy<_ValueType>( std::move(__ifirst), std::move(__ilast), std::move(__ofirst), __always_false()); return std::move(__result.second); } // uninitialized_copy_n template inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst, _EndPredicate __stop_copying) { _ForwardIterator __idx = __ofirst; #ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { #endif for (; __n > 0 && !__stop_copying(__idx); ++__ifirst, (void)++__idx, (void)--__n) ::new (std::__voidify(*__idx)) _ValueType(*__ifirst); #ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__ofirst, __idx); throw; } #endif return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx)); } template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) { typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType; auto __result = std::__uninitialized_copy_n<_ValueType>(std::move(__ifirst), __n, std::move(__ofirst), __always_false()); return std::move(__result.second); } // uninitialized_fill template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_fill(_ForwardIterator __first, _Sentinel __last, const _Tp& __x) { _ForwardIterator __idx = __first; #ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { #endif for (; __idx != __last; ++__idx) ::new (std::__voidify(*__idx)) _ValueType(__x); #ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__first, __idx); throw; } #endif return __idx; } template inline _LIBCPP_HIDE_FROM_ABI void uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __x) { typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType; (void)std::__uninitialized_fill<_ValueType>(__first, __last, __x); } // uninitialized_fill_n template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) { _ForwardIterator __idx = __first; #ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { #endif for (; __n > 0; ++__idx, (void)--__n) ::new (std::__voidify(*__idx)) _ValueType(__x); #ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__first, __idx); throw; } #endif return __idx; } template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) { typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType; return std::__uninitialized_fill_n<_ValueType>(__first, __n, __x); } #if _LIBCPP_STD_VER >= 17 // uninitialized_default_construct template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_default_construct(_ForwardIterator __first, _Sentinel __last) { auto __idx = __first; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { # endif for (; __idx != __last; ++__idx) ::new (std::__voidify(*__idx)) _ValueType; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__first, __idx); throw; } # endif return __idx; } template inline _LIBCPP_HIDE_FROM_ABI void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) { using _ValueType = typename iterator_traits<_ForwardIterator>::value_type; (void)std::__uninitialized_default_construct<_ValueType>(std::move(__first), std::move(__last)); } // uninitialized_default_construct_n template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) { auto __idx = __first; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { # endif for (; __n > 0; ++__idx, (void)--__n) ::new (std::__voidify(*__idx)) _ValueType; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__first, __idx); throw; } # endif return __idx; } template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) { using _ValueType = typename iterator_traits<_ForwardIterator>::value_type; return std::__uninitialized_default_construct_n<_ValueType>(std::move(__first), __n); } // uninitialized_value_construct template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_value_construct(_ForwardIterator __first, _Sentinel __last) { auto __idx = __first; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { # endif for (; __idx != __last; ++__idx) ::new (std::__voidify(*__idx)) _ValueType(); # ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__first, __idx); throw; } # endif return __idx; } template inline _LIBCPP_HIDE_FROM_ABI void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) { using _ValueType = typename iterator_traits<_ForwardIterator>::value_type; (void)std::__uninitialized_value_construct<_ValueType>(std::move(__first), std::move(__last)); } // uninitialized_value_construct_n template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) { auto __idx = __first; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { # endif for (; __n > 0; ++__idx, (void)--__n) ::new (std::__voidify(*__idx)) _ValueType(); # ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__first, __idx); throw; } # endif return __idx; } template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) { using _ValueType = typename iterator_traits<_ForwardIterator>::value_type; return std::__uninitialized_value_construct_n<_ValueType>(std::move(__first), __n); } // uninitialized_move template inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_move( _InputIterator __ifirst, _Sentinel1 __ilast, _ForwardIterator __ofirst, _EndPredicate __stop_moving, _IterMove __iter_move) { auto __idx = __ofirst; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { # endif for (; __ifirst != __ilast && !__stop_moving(__idx); ++__idx, (void)++__ifirst) { ::new (std::__voidify(*__idx)) _ValueType(__iter_move(__ifirst)); } # ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__ofirst, __idx); throw; } # endif return {std::move(__ifirst), std::move(__idx)}; } template inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_move(_InputIterator __ifirst, _InputIterator __ilast, _ForwardIterator __ofirst) { using _ValueType = typename iterator_traits<_ForwardIterator>::value_type; auto __iter_move = [](auto&& __iter) -> decltype(auto) { return std::move(*__iter); }; auto __result = std::__uninitialized_move<_ValueType>( std::move(__ifirst), std::move(__ilast), std::move(__ofirst), __always_false(), __iter_move); return std::move(__result.second); } // uninitialized_move_n template inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_move_n( _InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst, _EndPredicate __stop_moving, _IterMove __iter_move) { auto __idx = __ofirst; # ifndef _LIBCPP_HAS_NO_EXCEPTIONS try { # endif for (; __n > 0 && !__stop_moving(__idx); ++__idx, (void)++__ifirst, --__n) ::new (std::__voidify(*__idx)) _ValueType(__iter_move(__ifirst)); # ifndef _LIBCPP_HAS_NO_EXCEPTIONS } catch (...) { std::__destroy(__ofirst, __idx); throw; } # endif return {std::move(__ifirst), std::move(__idx)}; } template inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> uninitialized_move_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) { using _ValueType = typename iterator_traits<_ForwardIterator>::value_type; auto __iter_move = [](auto&& __iter) -> decltype(auto) { return std::move(*__iter); }; return std::__uninitialized_move_n<_ValueType>( std::move(__ifirst), __n, std::move(__ofirst), __always_false(), __iter_move); } // TODO: Rewrite this to iterate left to right and use reverse_iterators when calling // Destroys every element in the range [first, last) FROM RIGHT TO LEFT using allocator // destruction. If elements are themselves C-style arrays, they are recursively destroyed // in the same manner. // // This function assumes that destructors do not throw, and that the allocator is bound to // the correct type. template ::value, int> = 0> _LIBCPP_HIDE_FROM_ABI constexpr void __allocator_destroy_multidimensional(_Alloc& __alloc, _BidirIter __first, _BidirIter __last) noexcept { using _ValueType = typename iterator_traits<_BidirIter>::value_type; static_assert(is_same_v::value_type, _ValueType>, "The allocator should already be rebound to the correct type"); if (__first == __last) return; if constexpr (is_array_v<_ValueType>) { static_assert(!__libcpp_is_unbounded_array<_ValueType>::value, "arrays of unbounded arrays don't exist, but if they did we would mess up here"); using _Element = remove_extent_t<_ValueType>; __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc); do { --__last; decltype(auto) __array = *__last; std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + extent_v<_ValueType>); } while (__last != __first); } else { do { --__last; allocator_traits<_Alloc>::destroy(__alloc, std::addressof(*__last)); } while (__last != __first); } } // Constructs the object at the given location using the allocator's construct method. // // If the object being constructed is an array, each element of the array is allocator-constructed, // recursively. If an exception is thrown during the construction of an array, the initialized // elements are destroyed in reverse order of initialization using allocator destruction. // // This function assumes that the allocator is bound to the correct type. template _LIBCPP_HIDE_FROM_ABI constexpr void __allocator_construct_at_multidimensional(_Alloc& __alloc, _Tp* __loc) { static_assert(is_same_v::value_type, _Tp>, "The allocator should already be rebound to the correct type"); if constexpr (is_array_v<_Tp>) { using _Element = remove_extent_t<_Tp>; __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc); size_t __i = 0; _Tp& __array = *__loc; // If an exception is thrown, destroy what we have constructed so far in reverse order. auto __guard = std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i); }); for (; __i != extent_v<_Tp>; ++__i) { std::__allocator_construct_at_multidimensional(__elem_alloc, std::addressof(__array[__i])); } __guard.__complete(); } else { allocator_traits<_Alloc>::construct(__alloc, __loc); } } // Constructs the object at the given location using the allocator's construct method, passing along // the provided argument. // // If the object being constructed is an array, the argument is also assumed to be an array. Each // each element of the array being constructed is allocator-constructed from the corresponding // element of the argument array. If an exception is thrown during the construction of an array, // the initialized elements are destroyed in reverse order of initialization using allocator // destruction. // // This function assumes that the allocator is bound to the correct type. template _LIBCPP_HIDE_FROM_ABI constexpr void __allocator_construct_at_multidimensional(_Alloc& __alloc, _Tp* __loc, _Arg const& __arg) { static_assert(is_same_v::value_type, _Tp>, "The allocator should already be rebound to the correct type"); if constexpr (is_array_v<_Tp>) { static_assert(is_array_v<_Arg>, "Provided non-array initialization argument to __allocator_construct_at_multidimensional when " "trying to construct an array."); using _Element = remove_extent_t<_Tp>; __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc); size_t __i = 0; _Tp& __array = *__loc; // If an exception is thrown, destroy what we have constructed so far in reverse order. auto __guard = std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i); }); for (; __i != extent_v<_Tp>; ++__i) { std::__allocator_construct_at_multidimensional(__elem_alloc, std::addressof(__array[__i]), __arg[__i]); } __guard.__complete(); } else { allocator_traits<_Alloc>::construct(__alloc, __loc, __arg); } } // Given a range starting at it and containing n elements, initializes each element in the // range from left to right using the construct method of the allocator (rebound to the // correct type). // // If an exception is thrown, the initialized elements are destroyed in reverse order of // initialization using allocator_traits destruction. If the elements in the range are C-style // arrays, they are initialized element-wise using allocator construction, and recursively so. template ::difference_type> _LIBCPP_HIDE_FROM_ABI constexpr void __uninitialized_allocator_fill_n_multidimensional(_Alloc& __alloc, _BidirIter __it, _Size __n, _Tp const& __value) { using _ValueType = typename iterator_traits<_BidirIter>::value_type; __allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc); _BidirIter __begin = __it; // If an exception is thrown, destroy what we have constructed so far in reverse order. auto __guard = std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); }); for (; __n != 0; --__n, ++__it) { std::__allocator_construct_at_multidimensional(__value_alloc, std::addressof(*__it), __value); } __guard.__complete(); } // Same as __uninitialized_allocator_fill_n_multidimensional, but doesn't pass any initialization argument // to the allocator's construct method, which results in value initialization. template ::difference_type> _LIBCPP_HIDE_FROM_ABI constexpr void __uninitialized_allocator_value_construct_n_multidimensional(_Alloc& __alloc, _BidirIter __it, _Size __n) { using _ValueType = typename iterator_traits<_BidirIter>::value_type; __allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc); _BidirIter __begin = __it; // If an exception is thrown, destroy what we have constructed so far in reverse order. auto __guard = std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); }); for (; __n != 0; --__n, ++__it) { std::__allocator_construct_at_multidimensional(__value_alloc, std::addressof(*__it)); } __guard.__complete(); } #endif // _LIBCPP_STD_VER >= 17 // Destroy all elements in [__first, __last) from left to right using allocator destruction. template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __allocator_destroy(_Alloc& __alloc, _Iter __first, _Sent __last) { for (; __first != __last; ++__first) allocator_traits<_Alloc>::destroy(__alloc, std::__to_address(__first)); } template class _AllocatorDestroyRangeReverse { public: _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _AllocatorDestroyRangeReverse(_Alloc& __alloc, _Iter& __first, _Iter& __last) : __alloc_(__alloc), __first_(__first), __last_(__last) {} _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void operator()() const { std::__allocator_destroy(__alloc_, std::reverse_iterator<_Iter>(__last_), std::reverse_iterator<_Iter>(__first_)); } private: _Alloc& __alloc_; _Iter& __first_; _Iter& __last_; }; // Copy-construct [__first1, __last1) in [__first2, __first2 + N), where N is distance(__first1, __last1). // // The caller has to ensure that __first2 can hold at least N uninitialized elements. If an exception is thrown the // already copied elements are destroyed in reverse order of their construction. template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2 __uninitialized_allocator_copy_impl(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) { auto __destruct_first = __first2; auto __guard = std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Iter2>(__alloc, __destruct_first, __first2)); while (__first1 != __last1) { allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), *__first1); ++__first1; ++__first2; } __guard.__complete(); return __first2; } template struct __allocator_has_trivial_copy_construct : _Not<__has_construct<_Alloc, _Type*, const _Type&> > {}; template struct __allocator_has_trivial_copy_construct, _Type> : true_type {}; template , class _Out, __enable_if_t< // using _RawTypeIn because of the allocator extension is_trivially_copy_constructible<_RawTypeIn>::value && is_trivially_copy_assignable<_RawTypeIn>::value && is_same<__remove_const_t<_In>, __remove_const_t<_Out> >::value && __allocator_has_trivial_copy_construct<_Alloc, _RawTypeIn>::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Out* __uninitialized_allocator_copy_impl(_Alloc&, _In* __first1, _In* __last1, _Out* __first2) { // TODO: Remove the const_cast once we drop support for std::allocator if (__libcpp_is_constant_evaluated()) { while (__first1 != __last1) { std::__construct_at(std::__to_address(__first2), *__first1); ++__first1; ++__first2; } return __first2; } else { return std::copy(__first1, __last1, const_cast<_RawTypeIn*>(__first2)); } } template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2 __uninitialized_allocator_copy(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) { auto __unwrapped_range = std::__unwrap_range(__first1, __last1); auto __result = std::__uninitialized_allocator_copy_impl( __alloc, __unwrapped_range.first, __unwrapped_range.second, std::__unwrap_iter(__first2)); return std::__rewrap_iter(__first2, __result); } template struct __allocator_has_trivial_move_construct : _Not<__has_construct<_Alloc, _Type*, _Type&&> > {}; template struct __allocator_has_trivial_move_construct, _Type> : true_type {}; template struct __allocator_has_trivial_destroy : _Not<__has_destroy<_Alloc, _Tp*> > {}; template struct __allocator_has_trivial_destroy, _Up> : true_type {}; // __uninitialized_allocator_relocate relocates the objects in [__first, __last) into __result. // Relocation means that the objects in [__first, __last) are placed into __result as-if by move-construct and destroy, // except that the move constructor and destructor may never be called if they are known to be equivalent to a memcpy. // // Preconditions: __result doesn't contain any objects and [__first, __last) contains objects // Postconditions: __result contains the objects from [__first, __last) and // [__first, __last) doesn't contain any objects // // The strong exception guarantee is provided if any of the following are true: // - is_nothrow_move_constructible<_Tp> // - is_copy_constructible<_Tp> // - __libcpp_is_trivially_relocatable<_Tp> template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void __uninitialized_allocator_relocate(_Alloc& __alloc, _Tp* __first, _Tp* __last, _Tp* __result) { static_assert(__is_cpp17_move_insertable<_Alloc>::value, "The specified type does not meet the requirements of Cpp17MoveInsertable"); if (__libcpp_is_constant_evaluated() || !__libcpp_is_trivially_relocatable<_Tp>::value || !__allocator_has_trivial_move_construct<_Alloc, _Tp>::value || !__allocator_has_trivial_destroy<_Alloc, _Tp>::value) { auto __destruct_first = __result; auto __guard = std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Tp*>(__alloc, __destruct_first, __result)); auto __iter = __first; while (__iter != __last) { #ifndef _LIBCPP_HAS_NO_EXCEPTIONS allocator_traits<_Alloc>::construct(__alloc, __result, std::move_if_noexcept(*__iter)); #else allocator_traits<_Alloc>::construct(__alloc, __result, std::move(*__iter)); #endif ++__iter; ++__result; } __guard.__complete(); std::__allocator_destroy(__alloc, __first, __last); } else { __builtin_memcpy(const_cast<__remove_const_t<_Tp>*>(__result), __first, sizeof(_Tp) * (__last - __first)); } } _LIBCPP_END_NAMESPACE_STD _LIBCPP_POP_MACROS #endif // _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H