1 //===-- Support/ilist - Intrusive Linked List Template ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines classes to implement an intrusive doubly linked list class
11 // (ie each node of the list must contain a next and previous field for the
14 // The ilist_traits trait class is used to gain access to the next and previous
15 // fields of the node type that the list is instantiated with. If it is not
16 // specialized, the list defaults to using the getPrev(), getNext() method calls
17 // to get the next and previous pointers.
19 // The ilist class itself, should be a plug in replacement for list, assuming
20 // that the nodes contain next/prev pointers. This list replacement does not
21 // provides a constant time size() method, so be careful to use empty() when you
22 // really want to know if it's empty.
24 // The ilist class is implemented by allocating a 'tail' node when the list is
25 // created (using ilist_traits<>::createEndMarker()). This tail node is
26 // absolutely required because the user must be able to compute end()-1. Because
27 // of this, users of the direct next/prev links will see an extra link on the
28 // end of the list, which should be ignored.
30 // Requirements for a user of this list:
32 // 1. The user must provide {g|s}et{Next|Prev} methods, or specialize
33 // ilist_traits to provide an alternate way of getting and setting next and
36 //===----------------------------------------------------------------------===//
41 #include <Support/iterator>
46 template<typename NodeTy, typename Traits> class iplist;
47 template<typename NodeTy> class ilist_iterator;
49 // Template traits for intrusive list. By specializing this template class, you
50 // can change what next/prev fields are used to store the links...
51 template<typename NodeTy>
53 static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); }
54 static NodeTy *getNext(NodeTy *N) { return N->getNext(); }
55 static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); }
56 static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); }
58 static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); }
59 static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); }
61 static NodeTy *createNode() { return new NodeTy(); }
62 static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
65 void addNodeToList(NodeTy *NTy) {}
66 void removeNodeFromList(NodeTy *NTy) {}
67 void transferNodesFromList(iplist<NodeTy, ilist_traits> &L2,
68 ilist_iterator<NodeTy> first,
69 ilist_iterator<NodeTy> last) {}
72 // Const traits are the same as nonconst traits...
74 struct ilist_traits<const Ty> : public ilist_traits<Ty> {};
77 //===----------------------------------------------------------------------===//
78 // ilist_iterator<Node> - Iterator for intrusive list.
80 template<typename NodeTy>
82 : public bidirectional_iterator<NodeTy, ptrdiff_t> {
83 typedef ilist_traits<NodeTy> Traits;
84 typedef bidirectional_iterator<NodeTy, ptrdiff_t> super;
87 typedef size_t size_type;
88 typedef typename super::pointer pointer;
89 typedef typename super::reference reference;
94 ilist_iterator(pointer NP) : NodePtr(NP) {}
95 ilist_iterator(reference NR) : NodePtr(&NR) {}
96 ilist_iterator() : NodePtr(0) {}
98 // This is templated so that we can allow constructing a const iterator from
99 // a nonconst iterator...
100 template<class node_ty>
101 ilist_iterator(const ilist_iterator<node_ty> &RHS)
102 : NodePtr(RHS.getNodePtrUnchecked()) {}
104 // This is templated so that we can allow assigning to a const iterator from
105 // a nonconst iterator...
106 template<class node_ty>
107 const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) {
108 NodePtr = RHS.getNodePtrUnchecked();
113 operator pointer() const {
114 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
118 reference operator*() const {
119 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
122 pointer operator->() { return &operator*(); }
123 const pointer operator->() const { return &operator*(); }
125 // Comparison operators
126 bool operator==(const ilist_iterator &RHS) const {
127 return NodePtr == RHS.NodePtr;
129 bool operator!=(const ilist_iterator &RHS) const {
130 return NodePtr != RHS.NodePtr;
133 // Increment and decrement operators...
134 ilist_iterator &operator--() { // predecrement - Back up
135 NodePtr = Traits::getPrev(NodePtr);
136 assert(NodePtr && "--'d off the beginning of an ilist!");
139 ilist_iterator &operator++() { // preincrement - Advance
140 NodePtr = Traits::getNext(NodePtr);
141 assert(NodePtr && "++'d off the end of an ilist!");
144 ilist_iterator operator--(int) { // postdecrement operators...
145 ilist_iterator tmp = *this;
149 ilist_iterator operator++(int) { // postincrement operators...
150 ilist_iterator tmp = *this;
155 // Internal interface, do not use...
156 pointer getNodePtrUnchecked() const { return NodePtr; }
159 //===----------------------------------------------------------------------===//
160 // ilist_compat_iterator<Node> - Compatibility iterator for intrusive list.
161 // This makes an ilist<X> act like an std::list<X*>, where you have to
162 // dereference stuff multiple times. This should only be used for temporary
163 // migration purposes. Because we don't support "changing the pointer", we only
164 // expose constant pointers.
166 template<typename NodeTy>
167 class ilist_compat_iterator
168 : public bidirectional_iterator<NodeTy* const, ptrdiff_t> {
169 typedef ilist_traits<NodeTy> Traits;
170 typedef bidirectional_iterator<NodeTy* const, ptrdiff_t> super;
173 typedef size_t size_type;
174 typedef typename super::pointer pointer;
175 typedef typename super::reference reference;
180 ilist_compat_iterator(NodeTy *NP) : NodePtr(NP) {}
181 ilist_compat_iterator() : NodePtr(0) {}
183 // This is templated so that we can allow constructing a const iterator from
184 // a nonconst iterator...
185 template<class node_ty>
186 ilist_compat_iterator(const ilist_compat_iterator<node_ty> &RHS)
187 : NodePtr(RHS.getNodePtrUnchecked()) {}
189 // This is templated so that we can allow assigning to a const iterator from
190 // a nonconst iterator...
191 template<class node_ty>
192 const ilist_compat_iterator &operator=(const
193 ilist_compat_iterator<node_ty> &RHS) {
194 NodePtr = RHS.getNodePtrUnchecked();
199 operator pointer() const {
200 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
204 reference operator*() const {
205 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
208 pointer operator->() { return &operator*(); }
209 const pointer operator->() const { return &operator*(); }
211 // Comparison operators
212 bool operator==(const ilist_compat_iterator &RHS) const {
213 return NodePtr == RHS.NodePtr;
215 bool operator!=(const ilist_compat_iterator &RHS) const {
216 return NodePtr != RHS.NodePtr;
219 // Increment and decrement operators...
220 ilist_compat_iterator &operator--() { // predecrement - Back up
221 NodePtr = Traits::getPrev(NodePtr);
222 assert(NodePtr && "--'d off the beginning of an ilist!");
225 ilist_compat_iterator &operator++() { // preincrement - Advance
226 NodePtr = Traits::getNext(NodePtr);
227 assert(NodePtr && "++'d off the end of an ilist!");
230 ilist_compat_iterator operator--(int) { // postdecrement operators...
231 ilist_compat_iterator tmp = *this;
235 ilist_compat_iterator operator++(int) { // postincrement operators...
236 ilist_compat_iterator tmp = *this;
241 // Internal interface, do not use...
242 pointer getNodePtrUnchecked() const { return NodePtr; }
246 // Allow ilist_iterators to convert into pointers to a node automatically when
247 // used by the dyn_cast, cast, isa mechanisms...
249 template<typename From> struct simplify_type;
251 template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
252 typedef NodeTy* SimpleType;
254 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
258 template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
259 typedef NodeTy* SimpleType;
261 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
267 //===----------------------------------------------------------------------===//
269 // iplist - The subset of list functionality that can safely be used on nodes of
270 // polymorphic types, ie a heterogeneus list with a common base class that holds
271 // the next/prev pointers...
273 template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
274 class iplist : public Traits {
277 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
278 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
280 typedef NodeTy *pointer;
281 typedef const NodeTy *const_pointer;
282 typedef NodeTy &reference;
283 typedef const NodeTy &const_reference;
284 typedef NodeTy value_type;
285 typedef ilist_iterator<NodeTy> iterator;
286 typedef ilist_iterator<const NodeTy> const_iterator;
287 typedef size_t size_type;
288 typedef ptrdiff_t difference_type;
289 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
290 typedef std::reverse_iterator<iterator> reverse_iterator;
292 iplist() : Head(this->createNode()), Tail(Head) {
296 ~iplist() { clear(); delete Tail; }
298 // Iterator creation methods.
299 iterator begin() { return iterator(Head); }
300 const_iterator begin() const { return const_iterator(Head); }
301 iterator end() { return iterator(Tail); }
302 const_iterator end() const { return const_iterator(Tail); }
304 // reverse iterator creation methods.
305 reverse_iterator rbegin() { return reverse_iterator(end()); }
306 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
307 reverse_iterator rend() { return reverse_iterator(begin()); }
308 const_reverse_iterator rend() const {return const_reverse_iterator(begin());}
311 // "compatibility" iterator creation methods.
312 typedef ilist_compat_iterator<NodeTy> compat_iterator;
313 compat_iterator compat_begin() const { return compat_iterator(Head); }
314 compat_iterator compat_end() const { return compat_iterator(Tail); }
316 // Miscellaneous inspection routines.
317 size_type max_size() const { return size_type(-1); }
318 bool empty() const { return Head == Tail; }
320 // Front and back accessor functions...
322 assert(!empty() && "Called front() on empty list!");
325 const_reference front() const {
326 assert(!empty() && "Called front() on empty list!");
330 assert(!empty() && "Called back() on empty list!");
331 return *getPrev(Tail);
333 const_reference back() const {
334 assert(!empty() && "Called back() on empty list!");
335 return *getPrev(Tail);
338 void swap(iplist &RHS) {
339 abort(); // Swap does not use list traits callback correctly yet!
340 std::swap(Head, RHS.Head);
341 std::swap(Tail, RHS.Tail);
344 iterator insert(iterator where, NodeTy *New) {
345 NodeTy *CurNode = where.getNodePtrUnchecked(), *PrevNode = getPrev(CurNode);
346 setNext(New, CurNode);
347 setPrev(New, PrevNode);
350 setNext(PrevNode, New);
353 setPrev(CurNode, New);
355 addNodeToList(New); // Notify traits that we added a node...
359 NodeTy *remove(iterator &IT) {
360 assert(IT != end() && "Cannot remove end of list!");
362 NodeTy *NextNode = getNext(Node);
363 NodeTy *PrevNode = getPrev(Node);
366 setNext(PrevNode, NextNode);
369 setPrev(NextNode, PrevNode);
371 removeNodeFromList(Node); // Notify traits that we removed a node...
375 NodeTy *remove(const iterator &IT) {
377 return remove(MutIt);
380 // erase - remove a node from the controlled sequence... and delete it.
381 iterator erase(iterator where) {
382 delete remove(where);
388 // transfer - The heart of the splice function. Move linked list nodes from
389 // [first, last) into position.
391 void transfer(iterator position, iplist &L2, iterator first, iterator last) {
392 assert(first != last && "Should be checked by callers");
393 if (position != last) {
394 // Remove [first, last) from its old position.
395 NodeTy *First = &*first, *Prev = getPrev(First);
396 NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
403 // Splice [first, last) into its new position.
404 NodeTy *PosNext = position.getNodePtrUnchecked();
405 NodeTy *PosPrev = getPrev(PosNext);
407 // Fix head of list...
409 setNext(PosPrev, First);
412 setPrev(First, PosPrev);
414 // Fix end of list...
415 setNext(Last, PosNext);
416 setPrev(PosNext, Last);
418 transferNodesFromList(L2, First, PosNext);
424 //===----------------------------------------------------------------------===
425 // Functionality derived from other functions defined above...
428 size_type size() const {
430 size_type Result = std::distance(begin(), end());
432 size_type Result = 0;
433 std::distance(begin(), end(), Result);
438 iterator erase(iterator first, iterator last) {
439 while (first != last)
440 first = erase(first);
444 void clear() { erase(begin(), end()); }
446 // Front and back inserters...
447 void push_front(NodeTy *val) { insert(begin(), val); }
448 void push_back(NodeTy *val) { insert(end(), val); }
450 assert(!empty() && "pop_front() on empty list!");
454 assert(!empty() && "pop_back() on empty list!");
455 iterator t = end(); erase(--t);
458 // Special forms of insert...
459 template<class InIt> void insert(iterator where, InIt first, InIt last) {
460 for (; first != last; ++first) insert(where, *first);
463 // Splice members - defined in terms of transfer...
464 void splice(iterator where, iplist &L2) {
466 transfer(where, L2, L2.begin(), L2.end());
468 void splice(iterator where, iplist &L2, iterator first) {
469 iterator last = first; ++last;
470 if (where == first || where == last) return; // No change
471 transfer(where, L2, first, last);
473 void splice(iterator where, iplist &L2, iterator first, iterator last) {
474 if (first != last) transfer(where, L2, first, last);
479 //===----------------------------------------------------------------------===
480 // High-Level Functionality that shouldn't really be here, but is part of list
483 // These two functions are actually called remove/remove_if in list<>, but
484 // they actually do the job of erase, rename them accordingly.
486 void erase(const NodeTy &val) {
487 for (iterator I = begin(), E = end(); I != E; ) {
488 iterator next = I; ++next;
489 if (*I == val) erase(I);
493 template<class Pr1> void erase_if(Pr1 pred) {
494 for (iterator I = begin(), E = end(); I != E; ) {
495 iterator next = I; ++next;
496 if (pred(*I)) erase(I);
501 template<class Pr2> void unique(Pr2 pred) {
503 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
511 void unique() { unique(op_equal); }
513 template<class Pr3> void merge(iplist &right, Pr3 pred) {
514 iterator first1 = begin(), last1 = end();
515 iterator first2 = right.begin(), last2 = right.end();
516 while (first1 != last1 && first2 != last2)
517 if (pred(*first2, *first1)) {
518 iterator next = first2;
519 transfer(first1, right, first2, ++next);
524 if (first2 != last2) transfer(last1, right, first2, last2);
526 void merge(iplist &right) { return merge(right, op_less); }
528 template<class Pr3> void sort(Pr3 pred);
529 void sort() { sort(op_less); }
534 template<typename NodeTy>
535 struct ilist : public iplist<NodeTy> {
536 typedef typename iplist<NodeTy>::size_type size_type;
537 typedef typename iplist<NodeTy>::iterator iterator;
540 ilist(const ilist &right) {
541 insert(this->begin(), right.begin(), right.end());
543 explicit ilist(size_type count) {
544 insert(this->begin(), count, NodeTy());
546 ilist(size_type count, const NodeTy &val) {
547 insert(this->begin(), count, val);
549 template<class InIt> ilist(InIt first, InIt last) {
550 insert(this->begin(), first, last);
554 // Forwarding functions: A workaround for GCC 2.95 which does not correctly
555 // support 'using' declarations to bring a hidden member into scope.
557 iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
558 void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
559 void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
562 // Main implementation here - Insert for a node passed by value...
563 iterator insert(iterator where, const NodeTy &val) {
564 return insert(where, createNode(val));
568 // Front and back inserters...
569 void push_front(const NodeTy &val) { insert(this->begin(), val); }
570 void push_back(const NodeTy &val) { insert(this->end(), val); }
572 // Special forms of insert...
573 template<class InIt> void insert(iterator where, InIt first, InIt last) {
574 for (; first != last; ++first) insert(where, *first);
576 void insert(iterator where, size_type count, const NodeTy &val) {
577 for (; count != 0; --count) insert(where, val);
580 // Assign special forms...
581 void assign(size_type count, const NodeTy &val) {
582 iterator I = this->begin();
583 for (; I != this->end() && count != 0; ++I, --count)
586 insert(this->end(), val, val);
588 erase(I, this->end());
590 template<class InIt> void assign(InIt first1, InIt last1) {
591 iterator first2 = this->begin(), last2 = this->end();
592 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
595 erase(first1, last1);
597 insert(last1, first2, last2);
602 void resize(size_type newsize, NodeTy val) {
603 iterator i = this->begin();
605 for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ;
608 erase(i, this->end());
610 insert(this->end(), newsize - len, val);
612 void resize(size_type newsize) { resize(newsize, NodeTy()); }
615 } // End llvm namespace
618 // Ensure that swap uses the fast list swap...
620 void swap(llvm::iplist<Ty> &Left, llvm::iplist<Ty> &Right) {
623 } // End 'std' extensions...