Author: ericwf Date: Sun Jan 3 21:27:52 2016 New Revision: 256727 URL: http://llvm.org/viewvc/llvm-project?rev=256727&view=rev Log: Remove unsafe "__as_link()" cast member function.
"__as_link()" can only be used safely on "__list_node" objects. This patch moves the "__as_link()" member function from "__list_node_base" to "__list_node" so it cannot be used incorrectly. Unsafe downcasts now use a non-member function so we don't defer the type-punned pointer. Modified: libcxx/trunk/include/list Modified: libcxx/trunk/include/list URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/list?rev=256727&r1=256726&r2=256727&view=diff ============================================================================== --- libcxx/trunk/include/list (original) +++ libcxx/trunk/include/list Sun Jan 3 21:27:52 2016 @@ -207,6 +207,22 @@ struct __list_node_pointer_traits { >::type __link_pointer; #endif + typedef typename conditional< + is_same<__link_pointer, __node_pointer>::value, + __base_pointer, + __node_pointer + >::type __non_link_pointer; + + static _LIBCPP_INLINE_VISIBILITY + __link_pointer __unsafe_link_pointer_cast(__link_pointer __p) { + return __p; + } + + static _LIBCPP_INLINE_VISIBILITY + __link_pointer __unsafe_link_pointer_cast(__non_link_pointer __p) { + return static_cast<__link_pointer>(static_cast<_VoidPtr>(__p)); + } + }; template <class _Tp, class _VoidPtr> @@ -221,22 +237,17 @@ struct __list_node_base __link_pointer __next_; _LIBCPP_INLINE_VISIBILITY - __list_node_base() : __prev_(__as_link()), __next_(__as_link()) {} + __list_node_base() : __prev_(_NodeTraits::__unsafe_link_pointer_cast(__self())), + __next_(_NodeTraits::__unsafe_link_pointer_cast(__self())) {} _LIBCPP_INLINE_VISIBILITY - __base_pointer __as_base() { + __base_pointer __self() { return pointer_traits<__base_pointer>::pointer_to(*this); } _LIBCPP_INLINE_VISIBILITY - __link_pointer __as_link() { - return static_cast<__link_pointer>(static_cast<_VoidPtr>( - __as_base())); - } - - _LIBCPP_INLINE_VISIBILITY __node_pointer __as_node() { - return static_cast<__node_pointer>(__as_base()); + return static_cast<__node_pointer>(__self()); } }; @@ -245,6 +256,14 @@ struct __list_node : public __list_node_base<_Tp, _VoidPtr> { _Tp __value_; + + typedef __list_node_base<_Tp, _VoidPtr> __base; + typedef typename __base::__link_pointer __link_pointer; + + _LIBCPP_INLINE_VISIBILITY + __link_pointer __as_link() { + return static_cast<__link_pointer>(__base::__self()); + } }; template <class _Tp, class _Alloc = allocator<_Tp> > class _LIBCPP_TYPE_VIS_ONLY list; @@ -520,7 +539,8 @@ protected: typedef allocator_traits<__node_allocator> __node_alloc_traits; typedef typename __node_alloc_traits::pointer __node_pointer; typedef typename __node_alloc_traits::pointer __node_const_pointer; - typedef typename __list_node_pointer_traits<value_type, __void_pointer>::__link_pointer __link_pointer; + typedef __list_node_pointer_traits<value_type, __void_pointer> __node_pointer_traits; + typedef typename __node_pointer_traits::__link_pointer __link_pointer; typedef __link_pointer __link_const_pointer; typedef typename __alloc_traits::pointer pointer; typedef typename __alloc_traits::const_pointer const_pointer; @@ -533,6 +553,12 @@ protected: __compressed_pair<size_type, __node_allocator> __size_alloc_; _LIBCPP_INLINE_VISIBILITY + __link_pointer __end_as_link() const _NOEXCEPT { + return __node_pointer_traits::__unsafe_link_pointer_cast( + const_cast<__node_base&>(__end_).__self()); + } + + _LIBCPP_INLINE_VISIBILITY size_type& __sz() _NOEXCEPT {return __size_alloc_.first();} _LIBCPP_INLINE_VISIBILITY const size_type& __sz() const _NOEXCEPT @@ -576,18 +602,18 @@ protected: iterator end() _NOEXCEPT { #if _LIBCPP_DEBUG_LEVEL >= 2 - return iterator(__end_.__as_link(), this); + return iterator(__end_as_link(), this); #else - return iterator(__end_.__as_link()); + return iterator(__end_as_link()); #endif } _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT { #if _LIBCPP_DEBUG_LEVEL >= 2 - return const_iterator(const_cast<__node_base&>(__end_).__as_link(), this); + return const_iterator(__end_as_link(), this); #else - return const_iterator(const_cast<__node_base&>(__end_).__as_link()); + return const_iterator(__end_as_link()); #endif } @@ -681,7 +707,7 @@ __list_imp<_Tp, _Alloc>::clear() _NOEXCE { __node_allocator& __na = __node_alloc(); __link_pointer __f = __end_.__next_; - __link_pointer __l = __end_.__as_link(); + __link_pointer __l = __end_as_link(); __unlink_nodes(__f, __l->__prev_); __sz() = 0; while (__f != __l) @@ -728,13 +754,13 @@ __list_imp<_Tp, _Alloc>::swap(__list_imp swap(__sz(), __c.__sz()); swap(__end_, __c.__end_); if (__sz() == 0) - __end_.__next_ = __end_.__prev_ = __end_.__as_link(); + __end_.__next_ = __end_.__prev_ = __end_as_link(); else - __end_.__prev_->__next_ = __end_.__next_->__prev_ = __end_.__as_link(); + __end_.__prev_->__next_ = __end_.__next_->__prev_ = __end_as_link(); if (__c.__sz() == 0) - __c.__end_.__next_ = __c.__end_.__prev_ = __c.__end_.__as_link(); + __c.__end_.__next_ = __c.__end_.__prev_ = __c.__end_as_link(); else - __c.__end_.__prev_->__next_ = __c.__end_.__next_->__prev_ = __c.__end_.__as_link(); + __c.__end_.__prev_->__next_ = __c.__end_.__next_->__prev_ = __c.__end_as_link(); #if _LIBCPP_DEBUG_LEVEL >= 2 __libcpp_db* __db = __get_db(); @@ -747,7 +773,7 @@ __list_imp<_Tp, _Alloc>::swap(__list_imp { --__p; const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_); - if (__i->__ptr_ == __c.__end_.__as_link()) + if (__i->__ptr_ == __c.__end_as_link()) { __cn2->__add(*__p); if (--__cn1->end_ != __p) @@ -760,7 +786,7 @@ __list_imp<_Tp, _Alloc>::swap(__list_imp { --__p; const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_); - if (__i->__ptr_ == __end_.__as_link()) + if (__i->__ptr_ == __end_as_link()) { __cn1->__add(*__p); if (--__cn2->end_ != __p) @@ -1061,7 +1087,7 @@ inline _LIBCPP_INLINE_VISIBILITY void list<_Tp, _Alloc>::__link_nodes_at_front(__link_pointer __f, __link_pointer __l) { - __f->__prev_ = base::__end_.__as_link(); + __f->__prev_ = base::__end_as_link(); __l->__next_ = base::__end_.__next_; __l->__next_->__prev_ = __l; base::__end_.__next_ = __f; @@ -1073,7 +1099,7 @@ inline _LIBCPP_INLINE_VISIBILITY void list<_Tp, _Alloc>::__link_nodes_at_back(__link_pointer __f, __link_pointer __l) { - __l->__next_ = base::__end_.__as_link(); + __l->__next_ = base::__end_as_link(); __f->__prev_ = base::__end_.__prev_; __f->__prev_->__next_ = __f; base::__end_.__prev_ = __l; @@ -1892,7 +1918,7 @@ list<_Tp, _Alloc>::resize(size_type __n, throw; } #endif // _LIBCPP_NO_EXCEPTIONS - __link_nodes(base::__end_.__as_link(), __r.__ptr_, __e.__ptr_); + __link_nodes(base::__end_as_link(), __r.__ptr_, __e.__ptr_); base::__sz() += __ds; } } @@ -1924,7 +1950,7 @@ list<_Tp, _Alloc>::splice(const_iterator { --__p; iterator* __i = static_cast<iterator*>((*__p)->__i_); - if (__i->__ptr_ != __c.__end_.__as_link()) + if (__i->__ptr_ != __c.__end_as_link()) { __cn1->__add(*__p); (*__p)->__c_ = __cn1; @@ -2153,7 +2179,7 @@ list<_Tp, _Alloc>::merge(list& __c, _Com { --__p; iterator* __i = static_cast<iterator*>((*__p)->__i_); - if (__i->__ptr_ != __c.__end_.__as_link()) + if (__i->__ptr_ != __c.__end_as_link()) { __cn1->__add(*__p); (*__p)->__c_ = __cn1; @@ -2275,7 +2301,7 @@ template <class _Tp, class _Alloc> bool list<_Tp, _Alloc>::__dereferenceable(const const_iterator* __i) const { - return __i->__ptr_ != const_cast<__node_base&>(this->__end_).__as_link(); + return __i->__ptr_ != this->__end_as_link(); } template <class _Tp, class _Alloc> _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits