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Add support for "fancy" pointers to shared_ptr. Fixes PR20616

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Summary:
This patch add support for "fancy pointers/allocators" as well as fixing support for shared_pointer and "minimal" allocators.

Fancy pointers are class types that meet the NullablePointer requirements. In our case they are created by fancy allocators. `support/min_allocator.h` is an archetype for these types.

There are three types of changes made in this patch:
1. `_Alloc::template rebind<T>::other` -> `__allocator_traits_rebind<_Alloc, T>::type`. This change was made because allocators don't need a rebind template. `__allocator_traits_rebind` is used instead of `allocator_traits::rebind` because use of `allocator_traits::rebind` requires a workaround for when template aliases are unavailable.
2. `a.deallocate(this, 1)` -> `a.deallocate(pointer_traits<self>::pointer_to(*this), 1)`. This change change is made because fancy pointers aren't always constructible from raw pointers. 
3. `p.get()` -> `addressof(*p.get())`. Fancy pointers aren't actually a pointer. When we need a "real" pointer we take the address of dereferencing the fancy pointer. This should give us the actual raw pointer.

Test Plan: Tests were added using `support/min_allocator.h` to each affected shared_ptr overload and creation function. These tests can only be executed in C++11 or greater since min_allocator is only available then. A extra test was added for the non-variadic versions of allocate_shared. 

Reviewers: danalbert, mclow.lists

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D4859

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@220469 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Fiselier
2014-10-23 04:12:28 +00:00
parent 9b82e151fe
commit 4e7d53664d
5 changed files with 251 additions and 25 deletions
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64
include/memory
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@@ -3677,9 +3677,13 @@ template <class _Tp, class _Dp, class _Alloc>
void
__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
{
typename _Alloc::template rebind<__shared_ptr_pointer>::other __a(__data_.second());
typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _A;
typedef allocator_traits<_A> _ATraits;
typedef pointer_traits<typename _ATraits::pointer> _PTraits;
_A __a(__data_.second());
__data_.second().~_Alloc();
__a.deallocate(this, 1);
__a.deallocate(_PTraits::pointer_to(*this), 1);
}
template <class _Tp, class _Alloc>
@@ -3742,9 +3746,12 @@ template <class _Tp, class _Alloc>
void
__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
{
typename _Alloc::template rebind<__shared_ptr_emplace>::other __a(__data_.first());
typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _A;
typedef allocator_traits<_A> _ATraits;
typedef pointer_traits<typename _ATraits::pointer> _PTraits;
_A __a(__data_.first());
__data_.first().~_Alloc();
__a.deallocate(this, 1);
__a.deallocate(_PTraits::pointer_to(*this), 1);
}
template<class _Tp> class _LIBCPP_TYPE_VIS_ONLY enable_shared_from_this;
@@ -4090,12 +4097,13 @@ shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
{
#endif // _LIBCPP_NO_EXCEPTIONS
typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
typedef typename _Alloc::template rebind<_CntrlBlk>::other _A2;
typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
typedef __allocator_destructor<_A2> _D2;
_A2 __a2(__a);
unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
::new(__hold2.get()) _CntrlBlk(__p, __d, __a);
__cntrl_ = __hold2.release();
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__p, __d, __a);
__cntrl_ = _VSTD::addressof(*__hold2.release());
__enable_weak_this(__p);
#ifndef _LIBCPP_NO_EXCEPTIONS
}
@@ -4117,12 +4125,13 @@ shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
{
#endif // _LIBCPP_NO_EXCEPTIONS
typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
typedef typename _Alloc::template rebind<_CntrlBlk>::other _A2;
typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
typedef __allocator_destructor<_A2> _D2;
_A2 __a2(__a);
unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
::new(__hold2.get()) _CntrlBlk(__p, __d, __a);
__cntrl_ = __hold2.release();
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__p, __d, __a);
__cntrl_ = _VSTD::addressof(*__hold2.release());
#ifndef _LIBCPP_NO_EXCEPTIONS
}
catch (...)
@@ -4282,14 +4291,15 @@ shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
{
typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
typedef typename _Alloc::template rebind<_CntrlBlk>::other _A2;
typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
typedef __allocator_destructor<_A2> _D2;
_A2 __a2(__a);
unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
::new(__hold2.get()) _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
__r.__enable_weak_this(__r.__ptr_);
return __r;
}
@@ -4373,14 +4383,15 @@ shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
{
typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
typedef typename _Alloc::template rebind<_CntrlBlk>::other _Alloc2;
typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
typedef __allocator_destructor<_Alloc2> _D2;
_Alloc2 __alloc2(__a);
unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
::new(__hold2.get()) _CntrlBlk(__a);
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__a);
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
__r.__enable_weak_this(__r.__ptr_);
return __r;
}
@@ -4391,14 +4402,15 @@ shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
{
typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
typedef typename _Alloc::template rebind<_CntrlBlk>::other _Alloc2;
typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
typedef __allocator_destructor<_Alloc2> _D2;
_Alloc2 __alloc2(__a);
unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
::new(__hold2.get()) _CntrlBlk(__a, __a0);
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__a, __a0);
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
__r.__enable_weak_this(__r.__ptr_);
return __r;
}
@@ -4409,14 +4421,15 @@ shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
{
typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
typedef typename _Alloc::template rebind<_CntrlBlk>::other _Alloc2;
typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
typedef __allocator_destructor<_Alloc2> _D2;
_Alloc2 __alloc2(__a);
unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
::new(__hold2.get()) _CntrlBlk(__a, __a0, __a1);
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__a, __a0, __a1);
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
__r.__enable_weak_this(__r.__ptr_);
return __r;
}
@@ -4427,14 +4440,15 @@ shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
{
typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
typedef typename _Alloc::template rebind<_CntrlBlk>::other _Alloc2;
typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
typedef __allocator_destructor<_Alloc2> _D2;
_Alloc2 __alloc2(__a);
unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
::new(__hold2.get()) _CntrlBlk(__a, __a0, __a1, __a2);
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__a, __a0, __a1, __a2);
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
__r.__enable_weak_this(__r.__ptr_);
return __r;
}