[libcxx] r273835 - Fix PR27115 - enable_shared_from_this does not work as a virtual base class.
Eric Fiselier via cfe-commits
cfe-commits at lists.llvm.org
Sun Jun 26 16:56:32 PDT 2016
Author: ericwf
Date: Sun Jun 26 18:56:32 2016
New Revision: 273835
URL: http://llvm.org/viewvc/llvm-project?rev=273835&view=rev
Log:
Fix PR27115 - enable_shared_from_this does not work as a virtual base class.
See https://llvm.org/bugs/show_bug.cgi?id=27115
The problem was that the conversion from
'const enable_shared_from_this<T>*' to 'const T*' didn't work if
T inherited enable_shared_from_this as a virtual base class. The fix
is to take the original pointer passed to shared_ptr's constructor in the
__enable_weak_this method and perform an upcast to 'const T*' instead of
performing a downcast from the enable_shared_from_this base.
Modified:
libcxx/trunk/include/memory
libcxx/trunk/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
Modified: libcxx/trunk/include/memory
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/memory?rev=273835&r1=273834&r2=273835&view=diff
==============================================================================
--- libcxx/trunk/include/memory (original)
+++ libcxx/trunk/include/memory Sun Jun 26 18:56:32 2016
@@ -4115,23 +4115,22 @@ public:
private:
- template <class _Yp>
+ template <class _Yp, class _OrigPtr>
_LIBCPP_INLINE_VISIBILITY
void
- __enable_weak_this(const enable_shared_from_this<_Yp>* __e) _NOEXCEPT
+ __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
+ _OrigPtr* __ptr) _NOEXCEPT
{
+ typedef typename remove_cv<_Yp>::type _RawYp;
if (__e && __e->__weak_this_.expired())
{
- weak_ptr<_Yp> __tmp;
- __tmp.__ptr_ = const_cast<_Yp*>(static_cast<const _Yp*>(__e));
- __tmp.__cntrl_ = __cntrl_;
- __cntrl_->__add_weak();
- __e->__weak_this_.swap(__tmp);
+ __e->__weak_this_ = shared_ptr<_RawYp>(*this,
+ const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
}
}
_LIBCPP_INLINE_VISIBILITY
- void __enable_weak_this(const volatile void*) _NOEXCEPT {}
+ void __enable_weak_this(const volatile void*, const volatile void*) _NOEXCEPT {}
template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY shared_ptr;
template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY weak_ptr;
@@ -4165,7 +4164,7 @@ shared_ptr<_Tp>::shared_ptr(_Yp* __p,
typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
__cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), allocator<_Yp>());
__hold.release();
- __enable_weak_this(__p);
+ __enable_weak_this(__p, __p);
}
template<class _Tp>
@@ -4180,7 +4179,7 @@ shared_ptr<_Tp>::shared_ptr(_Yp* __p, _D
#endif // _LIBCPP_NO_EXCEPTIONS
typedef __shared_ptr_pointer<_Yp*, _Dp, allocator<_Yp> > _CntrlBlk;
__cntrl_ = new _CntrlBlk(__p, __d, allocator<_Yp>());
- __enable_weak_this(__p);
+ __enable_weak_this(__p, __p);
#ifndef _LIBCPP_NO_EXCEPTIONS
}
catch (...)
@@ -4230,7 +4229,7 @@ shared_ptr<_Tp>::shared_ptr(_Yp* __p, _D
::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
_CntrlBlk(__p, __d, __a);
__cntrl_ = _VSTD::addressof(*__hold2.release());
- __enable_weak_this(__p);
+ __enable_weak_this(__p, __p);
#ifndef _LIBCPP_NO_EXCEPTIONS
}
catch (...)
@@ -4341,7 +4340,7 @@ shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp
{
typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
__cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
- __enable_weak_this(__r.get());
+ __enable_weak_this(__r.get(), __r.get());
__r.release();
}
@@ -4369,7 +4368,7 @@ shared_ptr<_Tp>::shared_ptr(unique_ptr<_
{
typedef __shared_ptr_pointer<_Yp*, _Dp, allocator<_Yp> > _CntrlBlk;
__cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), allocator<_Yp>());
- __enable_weak_this(__r.get());
+ __enable_weak_this(__r.get(), __r.get());
}
__r.release();
}
@@ -4400,7 +4399,7 @@ shared_ptr<_Tp>::shared_ptr(unique_ptr<_
reference_wrapper<typename remove_reference<_Dp>::type>,
allocator<_Yp> > _CntrlBlk;
__cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), allocator<_Yp>());
- __enable_weak_this(__r.get());
+ __enable_weak_this(__r.get(), __r.get());
}
__r.release();
}
@@ -4421,7 +4420,7 @@ shared_ptr<_Tp>::make_shared(_Args&& ...
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4440,7 +4439,7 @@ shared_ptr<_Tp>::allocate_shared(const _
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4459,7 +4458,7 @@ shared_ptr<_Tp>::make_shared()
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4477,7 +4476,7 @@ shared_ptr<_Tp>::make_shared(_A0& __a0)
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4495,7 +4494,7 @@ shared_ptr<_Tp>::make_shared(_A0& __a0,
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4513,7 +4512,7 @@ shared_ptr<_Tp>::make_shared(_A0& __a0,
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = __hold2.release();
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4532,7 +4531,7 @@ shared_ptr<_Tp>::allocate_shared(const _
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4551,7 +4550,7 @@ shared_ptr<_Tp>::allocate_shared(const _
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4570,7 +4569,7 @@ shared_ptr<_Tp>::allocate_shared(const _
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
@@ -4589,7 +4588,7 @@ shared_ptr<_Tp>::allocate_shared(const _
shared_ptr<_Tp> __r;
__r.__ptr_ = __hold2.get()->get();
__r.__cntrl_ = _VSTD::addressof(*__hold2.release());
- __r.__enable_weak_this(__r.__ptr_);
+ __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
return __r;
}
Modified: libcxx/trunk/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp?rev=273835&r1=273834&r2=273835&view=diff
==============================================================================
--- libcxx/trunk/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp (original)
+++ libcxx/trunk/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp Sun Jun 26 18:56:32 2016
@@ -39,12 +39,28 @@ struct Z : Y {};
void nullDeleter(void*) {}
+struct Foo : virtual public std::enable_shared_from_this<Foo>
+{
+ virtual ~Foo() {}
+};
+
+struct Bar : public Foo {
+ Bar(int) {}
+};
+
+
int main()
{
{ // https://llvm.org/bugs/show_bug.cgi?id=18843
std::shared_ptr<T const> t1(new T);
std::shared_ptr<T const> t2(std::make_shared<T>());
}
+ { // https://llvm.org/bugs/show_bug.cgi?id=27115
+ std::shared_ptr<Bar> t1(new Bar(42));
+ assert(t1->shared_from_this() == t1);
+ std::shared_ptr<Bar> t2(std::make_shared<Bar>(42));
+ assert(t2->shared_from_this() == t2);
+ }
{
std::shared_ptr<Y> p(new Z);
std::shared_ptr<T> q = p->shared_from_this();
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