1 //==-- llvm/ADT/ilist.h - Intrusive Linked List Template ---------*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines classes to implement an intrusive doubly linked list class
11 // (i.e. each node of the list must contain a next and previous field for the
14 // The ilist class itself should be a plug in replacement for list. This list
15 // replacement does not provide a constant time size() method, so be careful to
16 // use empty() when you really want to know if it's empty.
18 // The ilist class is implemented as a circular list. The list itself contains
19 // a sentinel node, whose Next points at begin() and whose Prev points at
20 // rbegin(). The sentinel node itself serves as end() and rend().
22 //===----------------------------------------------------------------------===//
24 #ifndef LLVM_ADT_ILIST_H
25 #define LLVM_ADT_ILIST_H
27 #include "llvm/ADT/simple_ilist.h"
34 /// Use delete by default for iplist and ilist.
36 /// Specialize this to get different behaviour for ownership-related API. (If
37 /// you really want ownership semantics, consider using std::list or building
38 /// something like \a BumpPtrList.)
40 /// \see ilist_noalloc_traits
41 template <typename NodeTy> struct ilist_alloc_traits {
42 static void deleteNode(NodeTy *V) { delete V; }
45 /// Custom traits to do nothing on deletion.
47 /// Specialize ilist_alloc_traits to inherit from this to disable the
48 /// non-intrusive deletion in iplist (which implies ownership).
50 /// If you want purely intrusive semantics with no callbacks, consider using \a
51 /// simple_ilist instead.
55 /// struct ilist_alloc_traits<MyType> : ilist_noalloc_traits<MyType> {};
57 template <typename NodeTy> struct ilist_noalloc_traits {
58 static void deleteNode(NodeTy *V) {}
61 /// Callbacks do nothing by default in iplist and ilist.
63 /// Specialize this for to use callbacks for when nodes change their list
65 template <typename NodeTy> struct ilist_callback_traits {
66 void addNodeToList(NodeTy *) {}
67 void removeNodeFromList(NodeTy *) {}
69 /// Callback before transferring nodes to this list.
71 /// \pre \c this!=&OldList
72 template <class Iterator>
73 void transferNodesFromList(ilist_callback_traits &OldList, Iterator /*first*/,
79 /// A fragment for template traits for intrusive list that provides default
80 /// node related operations.
82 /// TODO: Remove this layer of indirection. It's not necessary.
83 template <typename NodeTy>
84 struct ilist_node_traits : ilist_alloc_traits<NodeTy>,
85 ilist_callback_traits<NodeTy> {};
87 /// Default template traits for intrusive list.
89 /// By inheriting from this, you can easily use default implementations for all
90 /// common operations.
92 /// TODO: Remove this customization point. Specializing ilist_traits is
93 /// already fully general.
94 template <typename NodeTy>
95 struct ilist_default_traits : public ilist_node_traits<NodeTy> {};
97 /// Template traits for intrusive list.
99 /// Customize callbacks and allocation semantics.
100 template <typename NodeTy>
101 struct ilist_traits : public ilist_default_traits<NodeTy> {};
103 /// Const traits should never be instantiated.
104 template <typename Ty> struct ilist_traits<const Ty> {};
106 namespace ilist_detail {
108 template <class T> T &make();
110 /// Type trait to check for a traits class that has a getNext member (as a
111 /// canary for any of the ilist_nextprev_traits API).
112 template <class TraitsT, class NodeT> struct HasGetNext {
115 template <size_t N> struct SFINAE {};
118 static Yes &test(U *I, decltype(I->getNext(&make<NodeT>())) * = 0);
119 template <class> static No &test(...);
122 static const bool value = sizeof(test<TraitsT>(nullptr)) == sizeof(Yes);
125 /// Type trait to check for a traits class that has a createSentinel member (as
126 /// a canary for any of the ilist_sentinel_traits API).
127 template <class TraitsT> struct HasCreateSentinel {
132 static Yes &test(U *I, decltype(I->createSentinel()) * = 0);
133 template <class> static No &test(...);
136 static const bool value = sizeof(test<TraitsT>(nullptr)) == sizeof(Yes);
139 /// Type trait to check for a traits class that has a createNode member.
140 /// Allocation should be managed in a wrapper class, instead of in
142 template <class TraitsT, class NodeT> struct HasCreateNode {
145 template <size_t N> struct SFINAE {};
148 static Yes &test(U *I, decltype(I->createNode(make<NodeT>())) * = 0);
149 template <class> static No &test(...);
152 static const bool value = sizeof(test<TraitsT>(nullptr)) == sizeof(Yes);
155 template <class TraitsT, class NodeT> struct HasObsoleteCustomization {
156 static const bool value = HasGetNext<TraitsT, NodeT>::value ||
157 HasCreateSentinel<TraitsT>::value ||
158 HasCreateNode<TraitsT, NodeT>::value;
161 } // end namespace ilist_detail
163 //===----------------------------------------------------------------------===//
165 /// A wrapper around an intrusive list with callbacks and non-intrusive
168 /// This wraps a purely intrusive list (like simple_ilist) with a configurable
169 /// traits class. The traits can implement callbacks and customize the
170 /// ownership semantics.
172 /// This is a subset of ilist functionality that can safely be used on nodes of
173 /// polymorphic types, i.e. a heterogeneous list with a common base class that
174 /// holds the next/prev pointers. The only state of the list itself is an
175 /// ilist_sentinel, which holds pointers to the first and last nodes in the
177 template <class IntrusiveListT, class TraitsT>
178 class iplist_impl : public TraitsT, IntrusiveListT {
179 typedef IntrusiveListT base_list_type;
182 typedef iplist_impl iplist_impl_type;
185 typedef typename base_list_type::pointer pointer;
186 typedef typename base_list_type::const_pointer const_pointer;
187 typedef typename base_list_type::reference reference;
188 typedef typename base_list_type::const_reference const_reference;
189 typedef typename base_list_type::value_type value_type;
190 typedef typename base_list_type::size_type size_type;
191 typedef typename base_list_type::difference_type difference_type;
192 typedef typename base_list_type::iterator iterator;
193 typedef typename base_list_type::const_iterator const_iterator;
194 typedef typename base_list_type::reverse_iterator reverse_iterator;
196 typename base_list_type::const_reverse_iterator const_reverse_iterator;
199 // TODO: Drop this assertion and the transitive type traits anytime after
200 // v4.0 is branched (i.e,. keep them for one release to help out-of-tree code
203 !ilist_detail::HasObsoleteCustomization<TraitsT, value_type>::value,
204 "ilist customization points have changed!");
206 static bool op_less(const_reference L, const_reference R) { return L < R; }
207 static bool op_equal(const_reference L, const_reference R) { return L == R; }
210 iplist_impl() = default;
212 iplist_impl(const iplist_impl &) = delete;
213 iplist_impl &operator=(const iplist_impl &) = delete;
215 iplist_impl(iplist_impl &&X)
216 : TraitsT(std::move(X)), IntrusiveListT(std::move(X)) {}
217 iplist_impl &operator=(iplist_impl &&X) {
218 *static_cast<TraitsT *>(this) = std::move(X);
219 *static_cast<IntrusiveListT *>(this) = std::move(X);
223 ~iplist_impl() { clear(); }
225 // Miscellaneous inspection routines.
226 size_type max_size() const { return size_type(-1); }
228 using base_list_type::begin;
229 using base_list_type::end;
230 using base_list_type::rbegin;
231 using base_list_type::rend;
232 using base_list_type::empty;
233 using base_list_type::front;
234 using base_list_type::back;
236 void swap(iplist_impl &RHS) {
237 assert(0 && "Swap does not use list traits callback correctly yet!");
238 base_list_type::swap(RHS);
241 iterator insert(iterator where, pointer New) {
242 this->addNodeToList(New); // Notify traits that we added a node...
243 return base_list_type::insert(where, *New);
246 iterator insert(iterator where, const_reference New) {
247 return this->insert(where, new value_type(New));
250 iterator insertAfter(iterator where, pointer New) {
252 return insert(begin(), New);
254 return insert(++where, New);
257 /// Clone another list.
258 template <class Cloner> void cloneFrom(const iplist_impl &L2, Cloner clone) {
260 for (const_reference V : L2)
264 pointer remove(iterator &IT) {
265 pointer Node = &*IT++;
266 this->removeNodeFromList(Node); // Notify traits that we removed a node...
267 base_list_type::remove(*Node);
271 pointer remove(const iterator &IT) {
273 return remove(MutIt);
276 pointer remove(pointer IT) { return remove(iterator(IT)); }
277 pointer remove(reference IT) { return remove(iterator(IT)); }
279 // erase - remove a node from the controlled sequence... and delete it.
280 iterator erase(iterator where) {
281 this->deleteNode(remove(where));
285 iterator erase(pointer IT) { return erase(iterator(IT)); }
286 iterator erase(reference IT) { return erase(iterator(IT)); }
288 /// Remove all nodes from the list like clear(), but do not call
289 /// removeNodeFromList() or deleteNode().
291 /// This should only be used immediately before freeing nodes in bulk to
292 /// avoid traversing the list and bringing all the nodes into cache.
293 void clearAndLeakNodesUnsafely() { base_list_type::clear(); }
296 // transfer - The heart of the splice function. Move linked list nodes from
297 // [first, last) into position.
299 void transfer(iterator position, iplist_impl &L2, iterator first, iterator last) {
300 if (position == last)
303 if (this != &L2) // Notify traits we moved the nodes...
304 this->transferNodesFromList(L2, first, last);
306 base_list_type::splice(position, L2, first, last);
310 //===----------------------------------------------------------------------===
311 // Functionality derived from other functions defined above...
314 using base_list_type::size;
316 iterator erase(iterator first, iterator last) {
317 while (first != last)
318 first = erase(first);
322 void clear() { erase(begin(), end()); }
324 // Front and back inserters...
325 void push_front(pointer val) { insert(begin(), val); }
326 void push_back(pointer val) { insert(end(), val); }
328 assert(!empty() && "pop_front() on empty list!");
332 assert(!empty() && "pop_back() on empty list!");
333 iterator t = end(); erase(--t);
336 // Special forms of insert...
337 template<class InIt> void insert(iterator where, InIt first, InIt last) {
338 for (; first != last; ++first) insert(where, *first);
341 // Splice members - defined in terms of transfer...
342 void splice(iterator where, iplist_impl &L2) {
344 transfer(where, L2, L2.begin(), L2.end());
346 void splice(iterator where, iplist_impl &L2, iterator first) {
347 iterator last = first; ++last;
348 if (where == first || where == last) return; // No change
349 transfer(where, L2, first, last);
351 void splice(iterator where, iplist_impl &L2, iterator first, iterator last) {
352 if (first != last) transfer(where, L2, first, last);
354 void splice(iterator where, iplist_impl &L2, reference N) {
355 splice(where, L2, iterator(N));
357 void splice(iterator where, iplist_impl &L2, pointer N) {
358 splice(where, L2, iterator(N));
361 template <class Compare>
362 void merge(iplist_impl &Right, Compare comp) {
365 this->transferNodesFromList(Right, Right.begin(), Right.end());
366 base_list_type::merge(Right, comp);
368 void merge(iplist_impl &Right) { return merge(Right, op_less); }
370 using base_list_type::sort;
372 /// \brief Get the previous node, or \c nullptr for the list head.
373 pointer getPrevNode(reference N) const {
374 auto I = N.getIterator();
377 return &*std::prev(I);
379 /// \brief Get the previous node, or \c nullptr for the list head.
380 const_pointer getPrevNode(const_reference N) const {
381 return getPrevNode(const_cast<reference >(N));
384 /// \brief Get the next node, or \c nullptr for the list tail.
385 pointer getNextNode(reference N) const {
386 auto Next = std::next(N.getIterator());
391 /// \brief Get the next node, or \c nullptr for the list tail.
392 const_pointer getNextNode(const_reference N) const {
393 return getNextNode(const_cast<reference >(N));
397 /// An intrusive list with ownership and callbacks specified/controlled by
398 /// ilist_traits, only with API safe for polymorphic types.
400 /// The \p Options parameters are the same as those for \a simple_ilist. See
401 /// there for a description of what's available.
402 template <class T, class... Options>
404 : public iplist_impl<simple_ilist<T, Options...>, ilist_traits<T>> {
405 typedef typename iplist::iplist_impl_type iplist_impl_type;
410 iplist(const iplist &X) = delete;
411 iplist &operator=(const iplist &X) = delete;
413 iplist(iplist &&X) : iplist_impl_type(std::move(X)) {}
414 iplist &operator=(iplist &&X) {
415 *static_cast<iplist_impl_type *>(this) = std::move(X);
420 template <class T, class... Options> using ilist = iplist<T, Options...>;
422 } // end namespace llvm
426 // Ensure that swap uses the fast list swap...
428 void swap(llvm::iplist<Ty> &Left, llvm::iplist<Ty> &Right) {
432 } // end namespace std
434 #endif // LLVM_ADT_ILIST_H