[libcxx-commits] [libcxx] [libc++] Remove the allocator<const T> extension (PR #102655)
Nikolas Klauser via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Aug 9 11:16:24 PDT 2024
https://github.com/philnik777 created https://github.com/llvm/llvm-project/pull/102655
In LLVM 19 removed the extension with an opt-in macro. This finally removes that option too and removes a few `const_cast`s where I know that they exist only to support this extension.
>From ee58c9915bbb3e9bd77d3e0cf05114a278d05674 Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Fri, 9 Aug 2024 20:14:41 +0200
Subject: [PATCH] [libc++] Remove the allocator<const T> extension
---
libcxx/docs/ReleaseNotes/20.rst | 2 +-
libcxx/include/__memory/allocator.h | 95 -------------------
.../__memory/uninitialized_algorithms.h | 16 ++--
3 files changed, 7 insertions(+), 106 deletions(-)
diff --git a/libcxx/docs/ReleaseNotes/20.rst b/libcxx/docs/ReleaseNotes/20.rst
index b319067394099a..7bb3f7bddaa665 100644
--- a/libcxx/docs/ReleaseNotes/20.rst
+++ b/libcxx/docs/ReleaseNotes/20.rst
@@ -62,7 +62,7 @@ Deprecations and Removals
``_LIBCPP_ENABLE_REMOVED_WEEKDAY_RELATIONAL_OPERATORS`` macro that was used to re-enable this extension will be
ignored in LLVM 20.
-- TODO: The ``_LIBCPP_ENABLE_REMOVED_ALLOCATOR_CONST`` macro will no longer have an effect.
+- The ``_LIBCPP_ENABLE_REMOVED_ALLOCATOR_CONST`` macro will no longer have an effect.
Upcoming Deprecations and Removals
----------------------------------
diff --git a/libcxx/include/__memory/allocator.h b/libcxx/include/__memory/allocator.h
index ae1f549626ee49..0dbdc41d3c3d14 100644
--- a/libcxx/include/__memory/allocator.h
+++ b/libcxx/include/__memory/allocator.h
@@ -47,22 +47,6 @@ class _LIBCPP_TEMPLATE_VIS allocator<void> {
typedef allocator<_Up> other;
};
};
-
-// TODO(LLVM 20): Remove the escape hatch
-# ifdef _LIBCPP_ENABLE_REMOVED_ALLOCATOR_CONST
-template <>
-class _LIBCPP_TEMPLATE_VIS allocator<const void> {
-public:
- _LIBCPP_DEPRECATED_IN_CXX17 typedef const void* pointer;
- _LIBCPP_DEPRECATED_IN_CXX17 typedef const void* const_pointer;
- _LIBCPP_DEPRECATED_IN_CXX17 typedef const void value_type;
-
- template <class _Up>
- struct _LIBCPP_DEPRECATED_IN_CXX17 rebind {
- typedef allocator<_Up> other;
- };
-};
-# endif // _LIBCPP_ENABLE_REMOVED_ALLOCATOR_CONST
#endif // _LIBCPP_STD_VER <= 17
// This class provides a non-trivial default constructor to the class that derives from it
@@ -171,85 +155,6 @@ class _LIBCPP_TEMPLATE_VIS allocator : private __non_trivial_if<!is_void<_Tp>::v
#endif
};
-// TODO(LLVM 20): Remove the escape hatch
-#ifdef _LIBCPP_ENABLE_REMOVED_ALLOCATOR_CONST
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
- : private __non_trivial_if<!is_void<_Tp>::value, allocator<const _Tp> > {
- static_assert(!is_volatile<_Tp>::value, "std::allocator does not support volatile types");
-
-public:
- typedef size_t size_type;
- typedef ptrdiff_t difference_type;
- typedef const _Tp value_type;
- typedef true_type propagate_on_container_move_assignment;
-# if _LIBCPP_STD_VER <= 23 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_ALLOCATOR_MEMBERS)
- _LIBCPP_DEPRECATED_IN_CXX23 typedef true_type is_always_equal;
-# endif
-
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 allocator() _NOEXCEPT = default;
-
- template <class _Up>
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 allocator(const allocator<_Up>&) _NOEXCEPT {}
-
- _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const _Tp* allocate(size_t __n) {
- if (__n > allocator_traits<allocator>::max_size(*this))
- __throw_bad_array_new_length();
- if (__libcpp_is_constant_evaluated()) {
- return static_cast<const _Tp*>(::operator new(__n * sizeof(_Tp)));
- } else {
- return static_cast<const _Tp*>(std::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
- }
- }
-
-# if _LIBCPP_STD_VER >= 23
- [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr allocation_result<const _Tp*> allocate_at_least(size_t __n) {
- return {allocate(__n), __n};
- }
-# endif
-
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void deallocate(const _Tp* __p, size_t __n) {
- if (__libcpp_is_constant_evaluated()) {
- ::operator delete(const_cast<_Tp*>(__p));
- } else {
- std::__libcpp_deallocate((void*)const_cast<_Tp*>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
- }
- }
-
- // C++20 Removed members
-# if _LIBCPP_STD_VER <= 17
- _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* pointer;
- _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* const_pointer;
- _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& reference;
- _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& const_reference;
-
- template <class _Up>
- struct _LIBCPP_DEPRECATED_IN_CXX17 rebind {
- typedef allocator<_Up> other;
- };
-
- _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_HIDE_FROM_ABI const_pointer address(const_reference __x) const _NOEXCEPT {
- return std::addressof(__x);
- }
-
- _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_DEPRECATED_IN_CXX17 const _Tp* allocate(size_t __n, const void*) {
- return allocate(__n);
- }
-
- _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT {
- return size_type(~0) / sizeof(_Tp);
- }
-
- template <class _Up, class... _Args>
- _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_HIDE_FROM_ABI void construct(_Up* __p, _Args&&... __args) {
- ::new ((void*)__p) _Up(std::forward<_Args>(__args)...);
- }
-
- _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_HIDE_FROM_ABI void destroy(pointer __p) { __p->~_Tp(); }
-# endif
-};
-#endif // _LIBCPP_ENABLE_REMOVED_ALLOCATOR_CONST
-
template <class _Tp, class _Up>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {
diff --git a/libcxx/include/__memory/uninitialized_algorithms.h b/libcxx/include/__memory/uninitialized_algorithms.h
index 7475ef5cf85def..72db3a266fdd4d 100644
--- a/libcxx/include/__memory/uninitialized_algorithms.h
+++ b/libcxx/include/__memory/uninitialized_algorithms.h
@@ -562,17 +562,13 @@ struct __allocator_has_trivial_copy_construct<allocator<_Type>, _Type> : true_ty
template <class _Alloc,
class _In,
- class _RawTypeIn = __remove_const_t<_In>,
class _Out,
- __enable_if_t<
- // using _RawTypeIn because of the allocator<T const> 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>
+ __enable_if_t<is_trivially_copy_constructible<_In>::value && is_trivially_copy_assignable<_In>::value &&
+ is_same<__remove_const_t<_In>, __remove_const_t<_Out> >::value &&
+ __allocator_has_trivial_copy_construct<_Alloc, _In>::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<T const>
if (__libcpp_is_constant_evaluated()) {
while (__first1 != __last1) {
std::__construct_at(std::__to_address(__first2), *__first1);
@@ -581,7 +577,7 @@ __uninitialized_allocator_copy_impl(_Alloc&, _In* __first1, _In* __last1, _Out*
}
return __first2;
} else {
- return std::copy(__first1, __last1, const_cast<_RawTypeIn*>(__first2));
+ return std::copy(__first1, __last1, __first2);
}
}
@@ -642,7 +638,7 @@ __uninitialized_allocator_relocate(_Alloc& __alloc, _Tp* __first, _Tp* __last, _
__guard.__complete();
std::__allocator_destroy(__alloc, __first, __last);
} else {
- __builtin_memcpy(const_cast<__remove_const_t<_Tp>*>(__result), __first, sizeof(_Tp) * (__last - __first));
+ __builtin_memcpy(__result, __first, sizeof(_Tp) * (__last - __first));
}
}
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