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Merged
merged 3 commits into from
Aug 9, 2022
Merged

<functional> should avoid including <memory> #2998

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bc00676
Replace <functional>'s usage of unique_ptr.
StephanTLavavej Aug 5, 2022
eb7a86d
Move _Ebco_base and align() from <memory> up to <xmemory>.
StephanTLavavej Aug 5, 2022
da81a41
Merge branch 'main' into functional-memory
StephanTLavavej Aug 9, 2022
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57 changes: 43 additions & 14 deletions stl/inc/functional
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,6 @@
#include <xmemory>
#include <xstddef>
#if _HAS_CXX17
#include <memory>
#include <unordered_map>
#endif // _HAS_CXX17
#ifdef __cpp_lib_concepts
Expand Down Expand Up @@ -2176,12 +2175,6 @@ _Ty* _Decode_aligned_block(void*& _Base, const size_t _Count) {
return static_cast<_Ty*>(_Decode_aligned_block(_Base, sizeof(_Ty) * _Count, alignof(_Ty)));
}

struct _Global_delete {
void operator()(void* const _Ptr) const {
::operator delete(_Ptr);
}
};

template <class _FwdItHaystack, class _FwdItPat, class _Pred_eq>
_CONSTEXPR20 pair<_FwdItHaystack, _FwdItHaystack> _Search_pair_unchecked(
_FwdItHaystack _First1, _FwdItHaystack _Last1, _FwdItPat _First2, _FwdItPat _Last2, _Pred_eq& _Eq) {
Expand Down Expand Up @@ -2325,6 +2318,41 @@ private:
_Diff _Table[_Limit];
};

// _Mini_ptr avoids needing to include <memory> which includes <atomic>.
// It doesn't attempt to provide all of unique_ptr's safety features; use carefully.
enum class _Deletion_kind { _Global_scalar, _Normal_array };

template <class _Ty, _Deletion_kind _Del>
class _Mini_ptr {
public:
explicit _Mini_ptr(_Ty* const _Ptr_) noexcept : _Ptr(_Ptr_) {}

~_Mini_ptr() noexcept {
if (_Ptr) {
if constexpr (_Del == _Deletion_kind::_Global_scalar) {
::operator delete(_Ptr);
} else if constexpr (_Del == _Deletion_kind::_Normal_array) {
delete[] _Ptr;
} else {
static_assert(_Always_false<_Ty>, "Unknown _Deletion_kind.");
}
}
}

_NODISCARD _Ty* _Get() const noexcept {
return _Ptr;
}

_NODISCARD _Ty* _Release() noexcept {
return _STD exchange(_Ptr, nullptr);
}

_Mini_ptr(const _Mini_ptr&) = delete;
_Mini_ptr& operator=(const _Mini_ptr&) = delete;

private:
_Ty* _Ptr;
};

template <class _RanItPat, class _Pred_eq>
void _Build_boyer_moore_delta_2_table(_Iter_diff_t<_RanItPat>* const _Shifts, const _RanItPat _Pat_first,
Expand All @@ -2345,7 +2373,8 @@ void _Build_boyer_moore_delta_2_table(_Iter_diff_t<_RanItPat>* const _Shifts, co

const auto _Mx = static_cast<size_t>(_Pat_size);

const unique_ptr<size_t[]> _Fx{new size_t[_Mx]};
const _Mini_ptr<size_t, _Deletion_kind::_Normal_array> _Fx_ptr{new size_t[_Mx]};
size_t* const _Fx = _Fx_ptr._Get();

for (size_t _Kx = 1; _Kx <= _Mx; ++_Kx) {
_Shifts[_Kx - 1] = static_cast<_Diff>(2 * _Mx - _Kx);
Expand Down Expand Up @@ -2496,8 +2525,8 @@ struct _Single_delta1_type_boyer_moore_traits {
_Add_alloc_size<_Diff>(_Buf_size, _Pat_size);
}

unique_ptr<void, _Global_delete> _Buf_bytes(::operator new(_Buf_size));
void* _Buf = _Buf_bytes.get();
_Mini_ptr<void, _Deletion_kind::_Global_scalar> _Buf_bytes(::operator new(_Buf_size));
void* _Buf = _Buf_bytes._Get();
*_Decode_aligned_block<_Atomic_counter_t>(_Buf) = 1;
void* const _Delta1 = _Decode_aligned_block<_Delta1_t>(_Buf);
if (_Build_delta2) {
Expand All @@ -2506,7 +2535,7 @@ struct _Single_delta1_type_boyer_moore_traits {
}

::new (_Delta1) _Delta1_t(_First, _UFirst, _Pat_size_raw, _STD move(_Hash_fn), _STD move(_Eq));
return _Buf_bytes.release();
return _Buf_bytes._Release();
}

template <class _RanItHaystack>
Expand Down Expand Up @@ -2590,8 +2619,8 @@ struct _Boyer_moore_traits_wchar_t_mode {
_Add_alloc_size<_Diff>(_Buf_size, _Pat_size);
}

unique_ptr<void, _Global_delete> _Buf_bytes(::operator new(_Buf_size));
void* _Buf = _Buf_bytes.get();
_Mini_ptr<void, _Deletion_kind::_Global_scalar> _Buf_bytes(::operator new(_Buf_size));
void* _Buf = _Buf_bytes._Get();
*_Decode_aligned_block<_Atomic_counter_t>(_Buf) = 1;
*_Decode_aligned_block<bool>(_Buf) = _Use_large_table;
if (_Use_large_table) {
Expand All @@ -2610,7 +2639,7 @@ struct _Boyer_moore_traits_wchar_t_mode {
_Decode_aligned_block<_Diff>(_Buf, _Pat_size), _UFirst, _Pat_size_raw, _Eq);
}

return _Buf_bytes.release();
return _Buf_bytes._Release();
}

template <class _RanItHaystack>
Expand Down
56 changes: 0 additions & 56 deletions stl/inc/memory
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Original file line number Diff line number Diff line change
Expand Up @@ -2396,45 +2396,6 @@ private:
};
#endif // _HAS_CXX20

template <class _Ty,
bool = is_empty_v<_Ty> && !is_final_v<_Ty>>
class _Ebco_base : private _Ty { // Empty Base Class Optimization, active
private:
using _Mybase = _Ty; // for visualization

protected:
template <class _Other, enable_if_t<!is_same_v<_Remove_cvref_t<_Other>, _Ebco_base>, int> = 0>
constexpr explicit _Ebco_base(_Other&& _Val) noexcept(is_nothrow_constructible_v<_Ty, _Other>)
: _Ty(_STD forward<_Other>(_Val)) {}

constexpr _Ty& _Get_val() noexcept {
return *this;
}

constexpr const _Ty& _Get_val() const noexcept {
return *this;
}
};

template <class _Ty>
class _Ebco_base<_Ty, false> { // Empty Base Class Optimization, inactive
private:
_Ty _Myval;

protected:
template <class _Other, enable_if_t<!is_same_v<_Remove_cvref_t<_Other>, _Ebco_base>, int> = 0>
constexpr explicit _Ebco_base(_Other&& _Val) noexcept(is_nothrow_constructible_v<_Ty, _Other>)
: _Myval(_STD forward<_Other>(_Val)) {}

constexpr _Ty& _Get_val() noexcept {
return _Myval;
}

constexpr const _Ty& _Get_val() const noexcept {
return _Myval;
}
};

template <class _Ty, class _Alloc>
class _Ref_count_obj_alloc3 : public _Ebco_base<_Rebind_alloc_t<_Alloc, _Ty>>, public _Ref_count_base {
// handle reference counting for object in control block, allocator
Expand Down Expand Up @@ -3710,23 +3671,6 @@ struct hash<shared_ptr<_Ty>> {
}
};

inline void* align(size_t _Bound, size_t _Size, void*& _Ptr, size_t& _Space) noexcept /* strengthened */ {
// try to carve out _Size bytes on boundary _Bound
size_t _Off = static_cast<size_t>(reinterpret_cast<uintptr_t>(_Ptr) & (_Bound - 1));
if (_Off != 0) {
_Off = _Bound - _Off; // number of bytes to skip
}

if (_Space < _Off || _Space - _Off < _Size) {
return nullptr;
}

// enough room, update
_Ptr = static_cast<char*>(_Ptr) + _Off;
_Space -= _Off;
return _Ptr;
}

#if _HAS_CXX20
template <size_t _Nx, class _Ty>
_NODISCARD constexpr _Ty* assume_aligned(_Ty* const _Ptr) noexcept /* strengthened */ {
Expand Down
56 changes: 56 additions & 0 deletions stl/inc/xmemory
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Original file line number Diff line number Diff line change
Expand Up @@ -2337,6 +2337,62 @@ template <_RANGES input_range _Rng>
using _Range_to_alloc_type =
pair<const typename _RANGES range_value_t<_Rng>::first_type, typename _RANGES range_value_t<_Rng>::second_type>;
#endif // __cpp_lib_containers_ranges

template <class _Ty,
bool = is_empty_v<_Ty> && !is_final_v<_Ty>>
class _Ebco_base : private _Ty { // Empty Base Class Optimization, active
private:
using _Mybase = _Ty; // for visualization

protected:
template <class _Other, enable_if_t<!is_same_v<_Remove_cvref_t<_Other>, _Ebco_base>, int> = 0>
constexpr explicit _Ebco_base(_Other&& _Val) noexcept(is_nothrow_constructible_v<_Ty, _Other>)
: _Ty(_STD forward<_Other>(_Val)) {}

constexpr _Ty& _Get_val() noexcept {
return *this;
}

constexpr const _Ty& _Get_val() const noexcept {
return *this;
}
};

template <class _Ty>
class _Ebco_base<_Ty, false> { // Empty Base Class Optimization, inactive
private:
_Ty _Myval;

protected:
template <class _Other, enable_if_t<!is_same_v<_Remove_cvref_t<_Other>, _Ebco_base>, int> = 0>
constexpr explicit _Ebco_base(_Other&& _Val) noexcept(is_nothrow_constructible_v<_Ty, _Other>)
: _Myval(_STD forward<_Other>(_Val)) {}

constexpr _Ty& _Get_val() noexcept {
return _Myval;
}

constexpr const _Ty& _Get_val() const noexcept {
return _Myval;
}
};

inline void* align(size_t _Bound, size_t _Size, void*& _Ptr, size_t& _Space) noexcept /* strengthened */ {
// try to carve out _Size bytes on boundary _Bound
size_t _Off = static_cast<size_t>(reinterpret_cast<uintptr_t>(_Ptr) & (_Bound - 1));
if (_Off != 0) {
_Off = _Bound - _Off; // number of bytes to skip
}

if (_Space < _Off || _Space - _Off < _Size) {
return nullptr;
}

// enough room, update
_Ptr = static_cast<char*>(_Ptr) + _Off;
_Space -= _Off;
return _Ptr;
}
_STD_END

#pragma pop_macro("new")
Expand Down