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 // do not implement. this is to catch errors when people try to use
160 // them as random access iterators
162 void operator-(int, ilist_iterator<T>);
164 void operator-(ilist_iterator<T>,int);
167 void operator+(int, ilist_iterator<T>);
169 void operator+(ilist_iterator<T>,int);
171 //===----------------------------------------------------------------------===//
172 // ilist_compat_iterator<Node> - Compatibility iterator for intrusive list.
173 // This makes an ilist<X> act like an std::list<X*>, where you have to
174 // dereference stuff multiple times. This should only be used for temporary
175 // migration purposes. Because we don't support "changing the pointer", we only
176 // expose constant pointers.
178 template<typename NodeTy>
179 class ilist_compat_iterator
180 : public bidirectional_iterator<NodeTy* const, ptrdiff_t> {
181 typedef ilist_traits<NodeTy> Traits;
182 typedef bidirectional_iterator<NodeTy* const, ptrdiff_t> super;
185 typedef size_t size_type;
186 typedef typename super::pointer pointer;
187 typedef typename super::reference reference;
192 ilist_compat_iterator(NodeTy *NP) : NodePtr(NP) {}
193 ilist_compat_iterator() : NodePtr(0) {}
195 // This is templated so that we can allow constructing a const iterator from
196 // a nonconst iterator...
197 template<class node_ty>
198 ilist_compat_iterator(const ilist_compat_iterator<node_ty> &RHS)
199 : NodePtr(RHS.getNodePtrUnchecked()) {}
201 // This is templated so that we can allow assigning to a const iterator from
202 // a nonconst iterator...
203 template<class node_ty>
204 const ilist_compat_iterator &operator=(const
205 ilist_compat_iterator<node_ty> &RHS) {
206 NodePtr = RHS.getNodePtrUnchecked();
211 operator pointer() const {
212 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
216 reference operator*() const {
217 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
220 pointer operator->() { return &operator*(); }
221 const pointer operator->() const { return &operator*(); }
223 // Comparison operators
224 bool operator==(const ilist_compat_iterator &RHS) const {
225 return NodePtr == RHS.NodePtr;
227 bool operator!=(const ilist_compat_iterator &RHS) const {
228 return NodePtr != RHS.NodePtr;
231 // Increment and decrement operators...
232 ilist_compat_iterator &operator--() { // predecrement - Back up
233 NodePtr = Traits::getPrev(NodePtr);
234 assert(NodePtr && "--'d off the beginning of an ilist!");
237 ilist_compat_iterator &operator++() { // preincrement - Advance
238 NodePtr = Traits::getNext(NodePtr);
239 assert(NodePtr && "++'d off the end of an ilist!");
242 ilist_compat_iterator operator--(int) { // postdecrement operators...
243 ilist_compat_iterator tmp = *this;
247 ilist_compat_iterator operator++(int) { // postincrement operators...
248 ilist_compat_iterator tmp = *this;
253 // Internal interface, do not use...
254 pointer getNodePtrUnchecked() const { return NodePtr; }
258 // Allow ilist_iterators to convert into pointers to a node automatically when
259 // used by the dyn_cast, cast, isa mechanisms...
261 template<typename From> struct simplify_type;
263 template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
264 typedef NodeTy* SimpleType;
266 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
270 template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
271 typedef NodeTy* SimpleType;
273 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
279 //===----------------------------------------------------------------------===//
281 // iplist - The subset of list functionality that can safely be used on nodes of
282 // polymorphic types, ie a heterogeneus list with a common base class that holds
283 // the next/prev pointers...
285 template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
286 class iplist : public Traits {
289 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
290 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
292 typedef NodeTy *pointer;
293 typedef const NodeTy *const_pointer;
294 typedef NodeTy &reference;
295 typedef const NodeTy &const_reference;
296 typedef NodeTy value_type;
297 typedef ilist_iterator<NodeTy> iterator;
298 typedef ilist_iterator<const NodeTy> const_iterator;
299 typedef size_t size_type;
300 typedef ptrdiff_t difference_type;
301 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
302 typedef std::reverse_iterator<iterator> reverse_iterator;
304 iplist() : Head(this->createNode()), Tail(Head) {
308 ~iplist() { clear(); delete Tail; }
310 // Iterator creation methods.
311 iterator begin() { return iterator(Head); }
312 const_iterator begin() const { return const_iterator(Head); }
313 iterator end() { return iterator(Tail); }
314 const_iterator end() const { return const_iterator(Tail); }
316 // reverse iterator creation methods.
317 reverse_iterator rbegin() { return reverse_iterator(end()); }
318 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
319 reverse_iterator rend() { return reverse_iterator(begin()); }
320 const_reverse_iterator rend() const {return const_reverse_iterator(begin());}
323 // "compatibility" iterator creation methods.
324 typedef ilist_compat_iterator<NodeTy> compat_iterator;
325 compat_iterator compat_begin() const { return compat_iterator(Head); }
326 compat_iterator compat_end() const { return compat_iterator(Tail); }
328 // Miscellaneous inspection routines.
329 size_type max_size() const { return size_type(-1); }
330 bool empty() const { return Head == Tail; }
332 // Front and back accessor functions...
334 assert(!empty() && "Called front() on empty list!");
337 const_reference front() const {
338 assert(!empty() && "Called front() on empty list!");
342 assert(!empty() && "Called back() on empty list!");
343 return *getPrev(Tail);
345 const_reference back() const {
346 assert(!empty() && "Called back() on empty list!");
347 return *getPrev(Tail);
350 void swap(iplist &RHS) {
351 abort(); // Swap does not use list traits callback correctly yet!
352 std::swap(Head, RHS.Head);
353 std::swap(Tail, RHS.Tail);
356 iterator insert(iterator where, NodeTy *New) {
357 NodeTy *CurNode = where.getNodePtrUnchecked(), *PrevNode = getPrev(CurNode);
358 setNext(New, CurNode);
359 setPrev(New, PrevNode);
362 setNext(PrevNode, New);
365 setPrev(CurNode, New);
367 addNodeToList(New); // Notify traits that we added a node...
371 NodeTy *remove(iterator &IT) {
372 assert(IT != end() && "Cannot remove end of list!");
374 NodeTy *NextNode = getNext(Node);
375 NodeTy *PrevNode = getPrev(Node);
378 setNext(PrevNode, NextNode);
381 setPrev(NextNode, PrevNode);
383 removeNodeFromList(Node); // Notify traits that we removed a node...
387 NodeTy *remove(const iterator &IT) {
389 return remove(MutIt);
392 // erase - remove a node from the controlled sequence... and delete it.
393 iterator erase(iterator where) {
394 delete remove(where);
400 // transfer - The heart of the splice function. Move linked list nodes from
401 // [first, last) into position.
403 void transfer(iterator position, iplist &L2, iterator first, iterator last) {
404 assert(first != last && "Should be checked by callers");
405 if (position != last) {
406 // Remove [first, last) from its old position.
407 NodeTy *First = &*first, *Prev = getPrev(First);
408 NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
415 // Splice [first, last) into its new position.
416 NodeTy *PosNext = position.getNodePtrUnchecked();
417 NodeTy *PosPrev = getPrev(PosNext);
419 // Fix head of list...
421 setNext(PosPrev, First);
424 setPrev(First, PosPrev);
426 // Fix end of list...
427 setNext(Last, PosNext);
428 setPrev(PosNext, Last);
430 transferNodesFromList(L2, First, PosNext);
436 //===----------------------------------------------------------------------===
437 // Functionality derived from other functions defined above...
440 size_type size() const {
442 size_type Result = std::distance(begin(), end());
444 size_type Result = 0;
445 std::distance(begin(), end(), Result);
450 iterator erase(iterator first, iterator last) {
451 while (first != last)
452 first = erase(first);
456 void clear() { erase(begin(), end()); }
458 // Front and back inserters...
459 void push_front(NodeTy *val) { insert(begin(), val); }
460 void push_back(NodeTy *val) { insert(end(), val); }
462 assert(!empty() && "pop_front() on empty list!");
466 assert(!empty() && "pop_back() on empty list!");
467 iterator t = end(); erase(--t);
470 // Special forms of insert...
471 template<class InIt> void insert(iterator where, InIt first, InIt last) {
472 for (; first != last; ++first) insert(where, *first);
475 // Splice members - defined in terms of transfer...
476 void splice(iterator where, iplist &L2) {
478 transfer(where, L2, L2.begin(), L2.end());
480 void splice(iterator where, iplist &L2, iterator first) {
481 iterator last = first; ++last;
482 if (where == first || where == last) return; // No change
483 transfer(where, L2, first, last);
485 void splice(iterator where, iplist &L2, iterator first, iterator last) {
486 if (first != last) transfer(where, L2, first, last);
491 //===----------------------------------------------------------------------===
492 // High-Level Functionality that shouldn't really be here, but is part of list
495 // These two functions are actually called remove/remove_if in list<>, but
496 // they actually do the job of erase, rename them accordingly.
498 void erase(const NodeTy &val) {
499 for (iterator I = begin(), E = end(); I != E; ) {
500 iterator next = I; ++next;
501 if (*I == val) erase(I);
505 template<class Pr1> void erase_if(Pr1 pred) {
506 for (iterator I = begin(), E = end(); I != E; ) {
507 iterator next = I; ++next;
508 if (pred(*I)) erase(I);
513 template<class Pr2> void unique(Pr2 pred) {
515 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
523 void unique() { unique(op_equal); }
525 template<class Pr3> void merge(iplist &right, Pr3 pred) {
526 iterator first1 = begin(), last1 = end();
527 iterator first2 = right.begin(), last2 = right.end();
528 while (first1 != last1 && first2 != last2)
529 if (pred(*first2, *first1)) {
530 iterator next = first2;
531 transfer(first1, right, first2, ++next);
536 if (first2 != last2) transfer(last1, right, first2, last2);
538 void merge(iplist &right) { return merge(right, op_less); }
540 template<class Pr3> void sort(Pr3 pred);
541 void sort() { sort(op_less); }
546 template<typename NodeTy>
547 struct ilist : public iplist<NodeTy> {
548 typedef typename iplist<NodeTy>::size_type size_type;
549 typedef typename iplist<NodeTy>::iterator iterator;
552 ilist(const ilist &right) {
553 insert(this->begin(), right.begin(), right.end());
555 explicit ilist(size_type count) {
556 insert(this->begin(), count, NodeTy());
558 ilist(size_type count, const NodeTy &val) {
559 insert(this->begin(), count, val);
561 template<class InIt> ilist(InIt first, InIt last) {
562 insert(this->begin(), first, last);
566 // Forwarding functions: A workaround for GCC 2.95 which does not correctly
567 // support 'using' declarations to bring a hidden member into scope.
569 iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
570 void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
571 void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
574 // Main implementation here - Insert for a node passed by value...
575 iterator insert(iterator where, const NodeTy &val) {
576 return insert(where, createNode(val));
580 // Front and back inserters...
581 void push_front(const NodeTy &val) { insert(this->begin(), val); }
582 void push_back(const NodeTy &val) { insert(this->end(), val); }
584 // Special forms of insert...
585 template<class InIt> void insert(iterator where, InIt first, InIt last) {
586 for (; first != last; ++first) insert(where, *first);
588 void insert(iterator where, size_type count, const NodeTy &val) {
589 for (; count != 0; --count) insert(where, val);
592 // Assign special forms...
593 void assign(size_type count, const NodeTy &val) {
594 iterator I = this->begin();
595 for (; I != this->end() && count != 0; ++I, --count)
598 insert(this->end(), val, val);
600 erase(I, this->end());
602 template<class InIt> void assign(InIt first1, InIt last1) {
603 iterator first2 = this->begin(), last2 = this->end();
604 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
607 erase(first1, last1);
609 insert(last1, first2, last2);
614 void resize(size_type newsize, NodeTy val) {
615 iterator i = this->begin();
617 for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ;
620 erase(i, this->end());
622 insert(this->end(), newsize - len, val);
624 void resize(size_type newsize) { resize(newsize, NodeTy()); }
627 } // End llvm namespace
630 // Ensure that swap uses the fast list swap...
632 void swap(llvm::iplist<Ty> &Left, llvm::iplist<Ty> &Right) {
635 } // End 'std' extensions...