Teach __hash_table how to handle unordered_map's __hash_value_type. This patch is fairly large and contains a number of changes. The main change is teaching '__hash_table' how to handle '__hash_value_type'. Unfortunately this change is a rampant layering violation, but it's required to make unordered_map conforming without re-writing all of __hash_table. After this change 'unordered_map' can delegate to '__hash_table' in almost all cases. The major changes found in this patch are: * Teach __hash_table to differentiate between the true container value type and the node value type by introducing the "__container_value_type" and "__node_value_type" typedefs. In the case of unordered_map '__container_value_type' is 'pair<const Key, Value>' and '__node_value_type' is '__hash_value_type'. * Switch almost all overloads in '__hash_table' previously taking 'value_type' (AKA '__node_value_type) to take '__container_value_type' instead. Previously 'pair<K, V>' would be implicitly converted to '__hash_value_type<K, V>' because of the function signature. * Add '__get_key', '__get_value', '__get_ptr', and '__move' static functions to '__key_value_types'. These functions allow '__hash_table' to unwrap '__node_value_type' objects into '__container_value_type' and its sub-parts. * Pass '__hash_value_type::__value_' to 'a.construct(p, ...)' instead of '__hash_value_type' itself. The C++14 standard requires that 'a.construct()' and 'a.destroy()' are only ever instantiated for the containers value type. * Remove '__hash_value_type's constructors and destructors. We should never construct an instance of this type. (TODO this is UB but we already do it in plenty of places). * Add a generic "try-emplace" function to '__hash_table' called '__emplace_unique_key_args(Key const&, Args...)'. The following changes were done as cleanup: * Introduce the '_LIBCPP_CXX03_LANG' macro to be used in place of '_LIBCPP_HAS_NO_VARIADICS' or '_LIBCPP_HAS_NO_RVALUE_REFERENCE'. * Cleanup C++11 only overloads that assume an incomplete C++11 implementation. For example this patch removes the __construct_node overloads that do manual pack expansion. * Forward 'unordered_map::emplace' to '__hash_table' and remove dead code resulting from the change. This includes almost all 'unordered_map::__construct_node' overloads. The following changes are planed for future revisions: * Fix LWG issue #2469 by delegating 'unordered_map::operator[]' to use '__emplace_unique_key_args'. * Rewrite 'unordered_map::try_emplace' in terms of '__emplace_unique_key_args'. * Optimize '__emplace_unique' to call '__emplace_unique_key_args' when possible. This prevent unneeded allocations when inserting duplicate entries. The additional follow up work needed after this patch: * Respect the lifetime rules for '__hash_value_type' by actually constructing it. * Make '__insert_multi' act similar to '__insert_unique' for objects of type 'T&' and 'T const &&' with 'T = __container_value_type'. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260513 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/unordered_map b/include/unordered_map index 89407b0..7e84f74 100644 --- a/include/unordered_map +++ b/include/unordered_map
@@ -583,8 +583,7 @@ } }; -#if __cplusplus >= 201103L - +#ifndef _LIBCPP_CXX03_LANG template <class _Key, class _Tp> union __hash_value_type { @@ -596,19 +595,6 @@ value_type __cc; __nc_value_type __nc; - template <class ..._Args> - _LIBCPP_INLINE_VISIBILITY - __hash_value_type(_Args&& ...__args) - : __cc(std::forward<_Args>(__args)...) {} - - _LIBCPP_INLINE_VISIBILITY - __hash_value_type(const __hash_value_type& __v) - : __cc(__v.__cc) {} - - _LIBCPP_INLINE_VISIBILITY - __hash_value_type(__hash_value_type&& __v) - : __nc(_VSTD::move(__v.__nc)) {} - _LIBCPP_INLINE_VISIBILITY __hash_value_type& operator=(const __hash_value_type& __v) {__nc = __v.__cc; return *this;} @@ -617,8 +603,23 @@ __hash_value_type& operator=(__hash_value_type&& __v) {__nc = _VSTD::move(__v.__nc); return *this;} + template <class _ValueTp, + class = typename enable_if< + __is_same_uncvref<_ValueTp, value_type>::value + >::type + > _LIBCPP_INLINE_VISIBILITY - ~__hash_value_type() {__cc.~value_type();} + __hash_value_type& operator=(_ValueTp&& __v) { + __nc = _VSTD::forward<_ValueTp>(__v); return *this; + } + +private: + __hash_value_type(const __hash_value_type& __v) = delete; + __hash_value_type(__hash_value_type&& __v) = delete; + template <class ..._Args> + explicit __hash_value_type(_Args&& ...__args) = delete; + + ~__hash_value_type() = delete; }; #else @@ -632,18 +633,8 @@ value_type __cc; - _LIBCPP_INLINE_VISIBILITY - __hash_value_type() {} - - template <class _A0> - _LIBCPP_INLINE_VISIBILITY - __hash_value_type(const _A0& __a0) - : __cc(__a0) {} - - template <class _A0, class _A1> - _LIBCPP_INLINE_VISIBILITY - __hash_value_type(const _A0& __a0, const _A1& __a1) - : __cc(__a0, __a1) {} +private: + ~__hash_value_type(); }; #endif @@ -780,6 +771,7 @@ __table __table_; + typedef typename __table::_NodeTypes _NodeTypes; typedef typename __table::__node_pointer __node_pointer; typedef typename __table::__node_const_pointer __node_const_pointer; typedef typename __table::__node_traits __node_traits; @@ -788,6 +780,9 @@ typedef __hash_map_node_destructor<__node_allocator> _Dp; typedef unique_ptr<__node, _Dp> __node_holder; typedef allocator_traits<allocator_type> __alloc_traits; + + static_assert((is_same<typename __table::__container_value_type, value_type>::value), ""); + static_assert((is_same<typename __table::__node_value_type, __value_type>::value), ""); public: typedef typename __alloc_traits::pointer pointer; typedef typename __alloc_traits::const_pointer const_pointer; @@ -913,28 +908,26 @@ _LIBCPP_INLINE_VISIBILITY const_iterator cend() const _NOEXCEPT {return __table_.end();} -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES -#ifndef _LIBCPP_HAS_NO_VARIADICS +#ifndef _LIBCPP_CXX03_LANG + template <class... _Args> + _LIBCPP_INLINE_VISIBILITY + pair<iterator, bool> emplace(_Args&&... __args) { + return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...); + } template <class... _Args> - pair<iterator, bool> emplace(_Args&&... __args); - - template <class... _Args> - _LIBCPP_INLINE_VISIBILITY + _LIBCPP_INLINE_VISIBILITY + iterator emplace_hint(const_iterator __p, _Args&&... __args) { #if _LIBCPP_DEBUG_LEVEL >= 2 - iterator emplace_hint(const_iterator __p, _Args&&... __args) - { - _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this, - "unordered_map::emplace_hint(const_iterator, args...) called with an iterator not" - " referring to this unordered_map"); - return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first; - } -#else - iterator emplace_hint(const_iterator, _Args&&... __args) - {return emplace(_VSTD::forward<_Args>(__args)...).first;} + _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this, + "unordered_map::emplace_hint(const_iterator, args...) called with an iterator not" + " referring to this unordered_map"); #endif -#endif // _LIBCPP_HAS_NO_VARIADICS -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES + return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first; + } + +#endif // _LIBCPP_CXX03_LANG + _LIBCPP_INLINE_VISIBILITY pair<iterator, bool> insert(const value_type& __x) {return __table_.__insert_unique(__x);} @@ -1191,17 +1184,9 @@ #endif // _LIBCPP_DEBUG_LEVEL >= 2 private: -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES - __node_holder __construct_node(); - template <class _A0> - __node_holder - __construct_node(_A0&& __a0); +#ifndef _LIBCPP_CXX03_LANG __node_holder __construct_node_with_key(key_type&& __k); -#ifndef _LIBCPP_HAS_NO_VARIADICS - template <class _A0, class _A1, class ..._Args> - __node_holder __construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args); -#endif // _LIBCPP_HAS_NO_VARIADICS -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES +#endif // _LIBCPP_CXX03_LANG __node_holder __construct_node_with_key(const key_type& __k); }; @@ -1328,10 +1313,10 @@ if (__a != __u.get_allocator()) { iterator __i = __u.begin(); - while (__u.size() != 0) - __table_.__insert_unique( - _VSTD::move(__u.__table_.remove((__i++).__i_)->__value_) - ); + while (__u.size() != 0) { + __table_.__emplace_unique(_VSTD::move( + __u.__table_.remove((__i++).__i_)->__value_.__nc)); + } } #if _LIBCPP_DEBUG_LEVEL >= 2 else @@ -1409,33 +1394,7 @@ #endif // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder -unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node() -{ - __node_allocator& __na = __table_.__node_alloc(); - __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); - __node_traits::construct(__na, _VSTD::addressof(__h->__value_)); - __h.get_deleter().__first_constructed = true; - __h.get_deleter().__second_constructed = true; - return __h; -} - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -template <class _A0> -typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder -unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(_A0&& __a0) -{ - __node_allocator& __na = __table_.__node_alloc(); - __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); - __node_traits::construct(__na, _VSTD::addressof(__h->__value_), - _VSTD::forward<_A0>(__a0)); - __h.get_deleter().__first_constructed = true; - __h.get_deleter().__second_constructed = true; - return __h; -} +#ifndef _LIBCPP_CXX03_LANG template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder @@ -1450,39 +1409,7 @@ return __h; } -#ifndef _LIBCPP_HAS_NO_VARIADICS - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -template <class _A0, class _A1, class ..._Args> -typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder -unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(_A0&& __a0, - _A1&& __a1, - _Args&&... __args) -{ - __node_allocator& __na = __table_.__node_alloc(); - __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); - __node_traits::construct(__na, _VSTD::addressof(__h->__value_), - _VSTD::forward<_A0>(__a0), _VSTD::forward<_A1>(__a1), - _VSTD::forward<_Args>(__args)...); - __h.get_deleter().__first_constructed = true; - __h.get_deleter().__second_constructed = true; - return __h; -} - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -template <class... _Args> -pair<typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator, bool> -unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::emplace(_Args&&... __args) -{ - __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); - pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get()); - if (__r.second) - __h.release(); - return __r; -} - -#endif // _LIBCPP_HAS_NO_VARIADICS -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES +#endif template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder @@ -1630,6 +1557,7 @@ __table __table_; + typedef typename __table::_NodeTypes _NodeTypes; typedef typename __table::__node_traits __node_traits; typedef typename __table::__node_allocator __node_allocator; typedef typename __table::__node __node; @@ -1765,16 +1693,18 @@ _LIBCPP_INLINE_VISIBILITY const_iterator cend() const _NOEXCEPT {return __table_.end();} -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES -#ifndef _LIBCPP_HAS_NO_VARIADICS +#ifndef _LIBCPP_CXX03_LANG + template <class... _Args> + iterator emplace(_Args&&... __args) { + return __table_.__emplace_multi(_VSTD::forward<_Args>(__args)...); + } template <class... _Args> - iterator emplace(_Args&&... __args); + iterator emplace_hint(const_iterator __p, _Args&&... __args) { + return __table_.__emplace_hint_multi(__p.__i_, _VSTD::forward<_Args>(__args)...); + } +#endif // _LIBCPP_CXX03_LANG - template <class... _Args> - iterator emplace_hint(const_iterator __p, _Args&&... __args); -#endif // _LIBCPP_HAS_NO_VARIADICS -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES _LIBCPP_INLINE_VISIBILITY iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);} #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES @@ -1888,17 +1818,7 @@ #endif // _LIBCPP_DEBUG_LEVEL >= 2 -private: -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES - __node_holder __construct_node(); - template <class _A0> - __node_holder - __construct_node(_A0&& __a0); -#ifndef _LIBCPP_HAS_NO_VARIADICS - template <class _A0, class _A1, class ..._Args> - __node_holder __construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args); -#endif // _LIBCPP_HAS_NO_VARIADICS -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES + }; template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> @@ -2027,7 +1947,7 @@ while (__u.size() != 0) { __table_.__insert_multi( - _VSTD::move(__u.__table_.remove((__i++).__i_)->__value_) + _VSTD::move(__u.__table_.remove((__i++).__i_)->__value_.__nc) ); } } @@ -2107,77 +2027,7 @@ #endif // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder -unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node() -{ - __node_allocator& __na = __table_.__node_alloc(); - __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); - __node_traits::construct(__na, _VSTD::addressof(__h->__value_)); - __h.get_deleter().__first_constructed = true; - __h.get_deleter().__second_constructed = true; - return __h; -} - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -template <class _A0> -typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder -unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(_A0&& __a0) -{ - __node_allocator& __na = __table_.__node_alloc(); - __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); - __node_traits::construct(__na, _VSTD::addressof(__h->__value_), - _VSTD::forward<_A0>(__a0)); - __h.get_deleter().__first_constructed = true; - __h.get_deleter().__second_constructed = true; - return __h; -} - -#ifndef _LIBCPP_HAS_NO_VARIADICS - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -template <class _A0, class _A1, class ..._Args> -typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder -unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node( - _A0&& __a0, _A1&& __a1, _Args&&... __args) -{ - __node_allocator& __na = __table_.__node_alloc(); - __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); - __node_traits::construct(__na, _VSTD::addressof(__h->__value_), - _VSTD::forward<_A0>(__a0), _VSTD::forward<_A1>(__a1), - _VSTD::forward<_Args>(__args)...); - __h.get_deleter().__first_constructed = true; - __h.get_deleter().__second_constructed = true; - return __h; -} - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -template <class... _Args> -typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator -unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::emplace(_Args&&... __args) -{ - __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); - iterator __r = __table_.__node_insert_multi(__h.get()); - __h.release(); - return __r; -} - -template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> -template <class... _Args> -typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator -unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::emplace_hint( - const_iterator __p, _Args&&... __args) -{ - __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); - iterator __r = __table_.__node_insert_multi(__p.__i_, __h.get()); - __h.release(); - return __r; -} - -#endif // _LIBCPP_HAS_NO_VARIADICS -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> template <class _InputIterator> 