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//==-- llvm/ADT/ilist.h - Intrusive Linked List Template ---------*- C++ -*-==//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file defines classes to implement an intrusive doubly linked list class
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// (i.e. each node of the list must contain a next and previous field for the
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// The ilist_traits trait class is used to gain access to the next and previous
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// fields of the node type that the list is instantiated with. If it is not
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// specialized, the list defaults to using the getPrev(), getNext() method calls
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// to get the next and previous pointers.
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// The ilist class itself, should be a plug in replacement for list, assuming
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// that the nodes contain next/prev pointers. This list replacement does not
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// provide a constant time size() method, so be careful to use empty() when you
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// really want to know if it's empty.
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// The ilist class is implemented by allocating a 'tail' node when the list is
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// created (using ilist_traits<>::createSentinel()). This tail node is
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// absolutely required because the user must be able to compute end()-1. Because
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// of this, users of the direct next/prev links will see an extra link on the
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// end of the list, which should be ignored.
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// Requirements for a user of this list:
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// 1. The user must provide {g|s}et{Next|Prev} methods, or specialize
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// ilist_traits to provide an alternate way of getting and setting next and
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ADT_ILIST_H
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#define LLVM_ADT_ILIST_H
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template<typename NodeTy, typename Traits> class iplist;
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template<typename NodeTy> class ilist_iterator;
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/// ilist_nextprev_traits - A fragment for template traits for intrusive list
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/// that provides default next/prev implementations for common operations.
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template<typename NodeTy>
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struct ilist_nextprev_traits {
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static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); }
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static NodeTy *getNext(NodeTy *N) { return N->getNext(); }
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static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); }
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static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); }
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static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); }
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static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); }
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template<typename NodeTy>
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/// ilist_sentinel_traits - A fragment for template traits for intrusive list
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/// that provides default sentinel implementations for common operations.
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/// ilist_sentinel_traits implements a lazy dynamic sentinel allocation
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/// strategy. The sentinel is stored in the prev field of ilist's Head.
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template<typename NodeTy>
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struct ilist_sentinel_traits {
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/// createSentinel - create the dynamic sentinel
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static NodeTy *createSentinel() { return new NodeTy(); }
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/// destroySentinel - deallocate the dynamic sentinel
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static void destroySentinel(NodeTy *N) { delete N; }
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/// provideInitialHead - when constructing an ilist, provide a starting
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/// value for its Head
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/// @return null node to indicate that it needs to be allocated later
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static NodeTy *provideInitialHead() { return 0; }
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/// ensureHead - make sure that Head is either already
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/// initialized or assigned a fresh sentinel
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/// @return the sentinel
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static NodeTy *ensureHead(NodeTy *&Head) {
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Head = ilist_traits<NodeTy>::createSentinel();
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ilist_traits<NodeTy>::noteHead(Head, Head);
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ilist_traits<NodeTy>::setNext(Head, 0);
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return ilist_traits<NodeTy>::getPrev(Head);
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/// noteHead - stash the sentinel into its default location
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static void noteHead(NodeTy *NewHead, NodeTy *Sentinel) {
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ilist_traits<NodeTy>::setPrev(NewHead, Sentinel);
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/// ilist_node_traits - A fragment for template traits for intrusive list
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/// that provides default node related operations.
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template<typename NodeTy>
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struct ilist_node_traits {
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static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
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static void deleteNode(NodeTy *V) { delete V; }
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void addNodeToList(NodeTy *) {}
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void removeNodeFromList(NodeTy *) {}
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void transferNodesFromList(ilist_node_traits & /*SrcTraits*/,
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ilist_iterator<NodeTy> /*first*/,
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ilist_iterator<NodeTy> /*last*/) {}
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/// ilist_default_traits - Default template traits for intrusive list.
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/// By inheriting from this, you can easily use default implementations
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/// for all common operations.
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template<typename NodeTy>
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struct ilist_default_traits : public ilist_nextprev_traits<NodeTy>,
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public ilist_sentinel_traits<NodeTy>,
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public ilist_node_traits<NodeTy> {
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// Template traits for intrusive list. By specializing this template class, you
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// can change what next/prev fields are used to store the links...
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template<typename NodeTy>
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struct ilist_traits : public ilist_default_traits<NodeTy> {};
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// Const traits are the same as nonconst traits...
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template<typename Ty>
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struct ilist_traits<const Ty> : public ilist_traits<Ty> {};
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//===----------------------------------------------------------------------===//
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// ilist_iterator<Node> - Iterator for intrusive list.
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template<typename NodeTy>
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: public std::iterator<std::bidirectional_iterator_tag, NodeTy, ptrdiff_t> {
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typedef ilist_traits<NodeTy> Traits;
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typedef std::iterator<std::bidirectional_iterator_tag,
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NodeTy, ptrdiff_t> super;
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typedef typename super::value_type value_type;
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typedef typename super::difference_type difference_type;
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typedef typename super::pointer pointer;
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typedef typename super::reference reference;
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// ilist_iterator is not a random-access iterator, but it has an
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// implicit conversion to pointer-type, which is. Declare (but
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// don't define) these functions as private to help catch
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// accidental misuse.
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void operator[](difference_type) const;
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void operator+(difference_type) const;
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void operator-(difference_type) const;
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void operator+=(difference_type) const;
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void operator-=(difference_type) const;
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template<class T> void operator<(T) const;
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template<class T> void operator<=(T) const;
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template<class T> void operator>(T) const;
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template<class T> void operator>=(T) const;
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template<class T> void operator-(T) const;
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ilist_iterator(pointer NP) : NodePtr(NP) {}
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ilist_iterator(reference NR) : NodePtr(&NR) {}
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ilist_iterator() : NodePtr(0) {}
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// This is templated so that we can allow constructing a const iterator from
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// a nonconst iterator...
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template<class node_ty>
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ilist_iterator(const ilist_iterator<node_ty> &RHS)
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: NodePtr(RHS.getNodePtrUnchecked()) {}
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// This is templated so that we can allow assigning to a const iterator from
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// a nonconst iterator...
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template<class node_ty>
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const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) {
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NodePtr = RHS.getNodePtrUnchecked();
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operator pointer() const {
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reference operator*() const {
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pointer operator->() const { return &operator*(); }
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// Comparison operators
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bool operator==(const ilist_iterator &RHS) const {
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return NodePtr == RHS.NodePtr;
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bool operator!=(const ilist_iterator &RHS) const {
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return NodePtr != RHS.NodePtr;
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// Increment and decrement operators...
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ilist_iterator &operator--() { // predecrement - Back up
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NodePtr = Traits::getPrev(NodePtr);
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assert(NodePtr && "--'d off the beginning of an ilist!");
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ilist_iterator &operator++() { // preincrement - Advance
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NodePtr = Traits::getNext(NodePtr);
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ilist_iterator operator--(int) { // postdecrement operators...
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ilist_iterator tmp = *this;
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ilist_iterator operator++(int) { // postincrement operators...
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ilist_iterator tmp = *this;
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// Internal interface, do not use...
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pointer getNodePtrUnchecked() const { return NodePtr; }
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// do not implement. this is to catch errors when people try to use
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// them as random access iterators
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void operator-(int, ilist_iterator<T>);
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void operator-(ilist_iterator<T>,int);
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void operator+(int, ilist_iterator<T>);
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void operator+(ilist_iterator<T>,int);
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// operator!=/operator== - Allow mixed comparisons without dereferencing
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// the iterator, which could very likely be pointing to end().
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bool operator!=(const T* LHS, const ilist_iterator<const T> &RHS) {
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return LHS != RHS.getNodePtrUnchecked();
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bool operator==(const T* LHS, const ilist_iterator<const T> &RHS) {
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return LHS == RHS.getNodePtrUnchecked();
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bool operator!=(T* LHS, const ilist_iterator<T> &RHS) {
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return LHS != RHS.getNodePtrUnchecked();
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bool operator==(T* LHS, const ilist_iterator<T> &RHS) {
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return LHS == RHS.getNodePtrUnchecked();
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// Allow ilist_iterators to convert into pointers to a node automatically when
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// used by the dyn_cast, cast, isa mechanisms...
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template<typename From> struct simplify_type;
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template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
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typedef NodeTy* SimpleType;
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static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
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template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
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typedef NodeTy* SimpleType;
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static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
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//===----------------------------------------------------------------------===//
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/// iplist - The subset of list functionality that can safely be used on nodes
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/// of polymorphic types, i.e. a heterogenous list with a common base class that
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/// holds the next/prev pointers. The only state of the list itself is a single
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/// pointer to the head of the list.
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/// This list can be in one of three interesting states:
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/// 1. The list may be completely unconstructed. In this case, the head
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/// pointer is null. When in this form, any query for an iterator (e.g.
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/// begin() or end()) causes the list to transparently change to state #2.
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/// 2. The list may be empty, but contain a sentinel for the end iterator. This
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/// sentinel is created by the Traits::createSentinel method and is a link
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/// in the list. When the list is empty, the pointer in the iplist points
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/// to the sentinel. Once the sentinel is constructed, it
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/// is not destroyed until the list is.
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/// 3. The list may contain actual objects in it, which are stored as a doubly
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/// linked list of nodes. One invariant of the list is that the predecessor
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/// of the first node in the list always points to the last node in the list,
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/// and the successor pointer for the sentinel (which always stays at the
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/// end of the list) is always null.
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template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
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class iplist : public Traits {
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mutable NodeTy *Head;
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// Use the prev node pointer of 'head' as the tail pointer. This is really a
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// circularly linked list where we snip the 'next' link from the sentinel node
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// back to the first node in the list (to preserve assertions about going off
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// the end of the list).
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NodeTy *getTail() { return this->ensureHead(Head); }
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const NodeTy *getTail() const { return this->ensureHead(Head); }
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void setTail(NodeTy *N) const { this->noteHead(Head, N); }
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/// CreateLazySentinel - This method verifies whether the sentinel for the
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/// list has been created and lazily makes it if not.
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void CreateLazySentinel() const {
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this->ensureHead(Head);
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static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
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static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
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// No fundamental reason why iplist can't be copyable, but the default
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// copy/copy-assign won't do.
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iplist(const iplist &); // do not implement
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void operator=(const iplist &); // do not implement
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typedef NodeTy *pointer;
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typedef const NodeTy *const_pointer;
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typedef NodeTy &reference;
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typedef const NodeTy &const_reference;
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typedef NodeTy value_type;
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typedef ilist_iterator<NodeTy> iterator;
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typedef ilist_iterator<const NodeTy> const_iterator;
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typedef size_t size_type;
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typedef ptrdiff_t difference_type;
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typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
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typedef std::reverse_iterator<iterator> reverse_iterator;
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iplist() : Head(this->provideInitialHead()) {}
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Traits::destroySentinel(getTail());
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// Iterator creation methods.
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CreateLazySentinel();
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return iterator(Head);
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const_iterator begin() const {
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CreateLazySentinel();
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return const_iterator(Head);
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CreateLazySentinel();
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return iterator(getTail());
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const_iterator end() const {
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CreateLazySentinel();
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return const_iterator(getTail());
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// reverse iterator creation methods.
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reverse_iterator rbegin() { return reverse_iterator(end()); }
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const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
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reverse_iterator rend() { return reverse_iterator(begin()); }
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const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
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// Miscellaneous inspection routines.
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size_type max_size() const { return size_type(-1); }
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bool empty() const { return Head == 0 || Head == getTail(); }
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// Front and back accessor functions...
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assert(!empty() && "Called front() on empty list!");
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const_reference front() const {
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assert(!empty() && "Called front() on empty list!");
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assert(!empty() && "Called back() on empty list!");
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return *this->getPrev(getTail());
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const_reference back() const {
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assert(!empty() && "Called back() on empty list!");
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return *this->getPrev(getTail());
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void swap(iplist &RHS) {
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assert(0 && "Swap does not use list traits callback correctly yet!");
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std::swap(Head, RHS.Head);
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iterator insert(iterator where, NodeTy *New) {
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NodeTy *CurNode = where.getNodePtrUnchecked();
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NodeTy *PrevNode = this->getPrev(CurNode);
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this->setNext(New, CurNode);
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this->setPrev(New, PrevNode);
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if (CurNode != Head) // Is PrevNode off the beginning of the list?
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this->setNext(PrevNode, New);
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this->setPrev(CurNode, New);
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this->addNodeToList(New); // Notify traits that we added a node...
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iterator insertAfter(iterator where, NodeTy *New) {
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return insert(begin(), New);
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return insert(++where, New);
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NodeTy *remove(iterator &IT) {
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assert(IT != end() && "Cannot remove end of list!");
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NodeTy *NextNode = this->getNext(Node);
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NodeTy *PrevNode = this->getPrev(Node);
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if (Node != Head) // Is PrevNode off the beginning of the list?
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this->setNext(PrevNode, NextNode);
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this->setPrev(NextNode, PrevNode);
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this->removeNodeFromList(Node); // Notify traits that we removed a node...
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// Set the next/prev pointers of the current node to null. This isn't
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// strictly required, but this catches errors where a node is removed from
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// an ilist (and potentially deleted) with iterators still pointing at it.
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// When those iterators are incremented or decremented, they will assert on
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// the null next/prev pointer instead of "usually working".
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this->setNext(Node, 0);
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this->setPrev(Node, 0);
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NodeTy *remove(const iterator &IT) {
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return remove(MutIt);
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// erase - remove a node from the controlled sequence... and delete it.
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iterator erase(iterator where) {
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this->deleteNode(remove(where));
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// transfer - The heart of the splice function. Move linked list nodes from
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// [first, last) into position.
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void transfer(iterator position, iplist &L2, iterator first, iterator last) {
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assert(first != last && "Should be checked by callers");
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if (position != last) {
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// Note: we have to be careful about the case when we move the first node
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// in the list. This node is the list sentinel node and we can't move it.
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NodeTy *ThisSentinel = getTail();
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NodeTy *L2Sentinel = L2.getTail();
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// Remove [first, last) from its old position.
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NodeTy *First = &*first, *Prev = this->getPrev(First);
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NodeTy *Next = last.getNodePtrUnchecked(), *Last = this->getPrev(Next);
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this->setNext(Prev, Next);
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this->setPrev(Next, Prev);
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// Splice [first, last) into its new position.
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NodeTy *PosNext = position.getNodePtrUnchecked();
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NodeTy *PosPrev = this->getPrev(PosNext);
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// Fix head of list...
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this->setNext(PosPrev, First);
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this->setPrev(First, PosPrev);
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// Fix end of list...
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this->setNext(Last, PosNext);
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this->setPrev(PosNext, Last);
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this->transferNodesFromList(L2, First, PosNext);
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// Now that everything is set, restore the pointers to the list sentinels.
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L2.setTail(L2Sentinel);
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setTail(ThisSentinel);
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//===----------------------------------------------------------------------===
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// Functionality derived from other functions defined above...
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size_type size() const {
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if (Head == 0) return 0; // Don't require construction of sentinel if empty.
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return std::distance(begin(), end());
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iterator erase(iterator first, iterator last) {
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while (first != last)
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first = erase(first);
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void clear() { if (Head) erase(begin(), end()); }
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// Front and back inserters...
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void push_front(NodeTy *val) { insert(begin(), val); }
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void push_back(NodeTy *val) { insert(end(), val); }
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assert(!empty() && "pop_front() on empty list!");
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assert(!empty() && "pop_back() on empty list!");
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iterator t = end(); erase(--t);
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// Special forms of insert...
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template<class InIt> void insert(iterator where, InIt first, InIt last) {
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for (; first != last; ++first) insert(where, *first);
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// Splice members - defined in terms of transfer...
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void splice(iterator where, iplist &L2) {
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transfer(where, L2, L2.begin(), L2.end());
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void splice(iterator where, iplist &L2, iterator first) {
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iterator last = first; ++last;
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if (where == first || where == last) return; // No change
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transfer(where, L2, first, last);
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void splice(iterator where, iplist &L2, iterator first, iterator last) {
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if (first != last) transfer(where, L2, first, last);
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//===----------------------------------------------------------------------===
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// High-Level Functionality that shouldn't really be here, but is part of list
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// These two functions are actually called remove/remove_if in list<>, but
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// they actually do the job of erase, rename them accordingly.
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void erase(const NodeTy &val) {
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for (iterator I = begin(), E = end(); I != E; ) {
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iterator next = I; ++next;
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if (*I == val) erase(I);
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template<class Pr1> void erase_if(Pr1 pred) {
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for (iterator I = begin(), E = end(); I != E; ) {
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iterator next = I; ++next;
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if (pred(*I)) erase(I);
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template<class Pr2> void unique(Pr2 pred) {
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for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
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void unique() { unique(op_equal); }
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template<class Pr3> void merge(iplist &right, Pr3 pred) {
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iterator first1 = begin(), last1 = end();
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iterator first2 = right.begin(), last2 = right.end();
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while (first1 != last1 && first2 != last2)
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if (pred(*first2, *first1)) {
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iterator next = first2;
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transfer(first1, right, first2, ++next);
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if (first2 != last2) transfer(last1, right, first2, last2);
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void merge(iplist &right) { return merge(right, op_less); }
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template<class Pr3> void sort(Pr3 pred);
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void sort() { sort(op_less); }
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template<typename NodeTy>
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struct ilist : public iplist<NodeTy> {
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typedef typename iplist<NodeTy>::size_type size_type;
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typedef typename iplist<NodeTy>::iterator iterator;
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ilist(const ilist &right) {
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insert(this->begin(), right.begin(), right.end());
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explicit ilist(size_type count) {
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insert(this->begin(), count, NodeTy());
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ilist(size_type count, const NodeTy &val) {
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insert(this->begin(), count, val);
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template<class InIt> ilist(InIt first, InIt last) {
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insert(this->begin(), first, last);
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// bring hidden functions into scope
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using iplist<NodeTy>::insert;
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using iplist<NodeTy>::push_front;
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using iplist<NodeTy>::push_back;
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// Main implementation here - Insert for a node passed by value...
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iterator insert(iterator where, const NodeTy &val) {
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return insert(where, this->createNode(val));
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// Front and back inserters...
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void push_front(const NodeTy &val) { insert(this->begin(), val); }
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void push_back(const NodeTy &val) { insert(this->end(), val); }
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// Special forms of insert...
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template<class InIt> void insert(iterator where, InIt first, InIt last) {
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for (; first != last; ++first) insert(where, *first);
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void insert(iterator where, size_type count, const NodeTy &val) {
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for (; count != 0; --count) insert(where, val);
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// Assign special forms...
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void assign(size_type count, const NodeTy &val) {
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iterator I = this->begin();
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for (; I != this->end() && count != 0; ++I, --count)
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insert(this->end(), val, val);
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erase(I, this->end());
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template<class InIt> void assign(InIt first1, InIt last1) {
673
iterator first2 = this->begin(), last2 = this->end();
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for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
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erase(first1, last1);
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insert(last1, first2, last2);
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void resize(size_type newsize, NodeTy val) {
685
iterator i = this->begin();
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for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ;
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erase(i, this->end());
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insert(this->end(), newsize - len, val);
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void resize(size_type newsize) { resize(newsize, NodeTy()); }
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} // End llvm namespace
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// Ensure that swap uses the fast list swap...
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void swap(llvm::iplist<Ty> &Left, llvm::iplist<Ty> &Right) {
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} // End 'std' extensions...
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#endif // LLVM_ADT_ILIST_H
added
removed
libclamav/c++/llvm/include/llvm/ADT/ilist.h
