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Diffstat (limited to 'include/llvm/ADT/ilist.h')
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1 files changed, 709 insertions, 0 deletions
diff --git a/include/llvm/ADT/ilist.h b/include/llvm/ADT/ilist.h new file mode 100644 index 0000000..9eb7005 --- /dev/null +++ b/include/llvm/ADT/ilist.h @@ -0,0 +1,709 @@ +//==-- llvm/ADT/ilist.h - Intrusive Linked List Template ---------*- C++ -*-==// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines classes to implement an intrusive doubly linked list class +// (i.e. each node of the list must contain a next and previous field for the +// list. +// +// The ilist_traits trait class is used to gain access to the next and previous +// fields of the node type that the list is instantiated with. If it is not +// specialized, the list defaults to using the getPrev(), getNext() method calls +// to get the next and previous pointers. +// +// The ilist class itself, should be a plug in replacement for list, assuming +// that the nodes contain next/prev pointers. This list replacement does not +// provide a constant time size() method, so be careful to use empty() when you +// really want to know if it's empty. +// +// The ilist class is implemented by allocating a 'tail' node when the list is +// created (using ilist_traits<>::createSentinel()). This tail node is +// absolutely required because the user must be able to compute end()-1. Because +// of this, users of the direct next/prev links will see an extra link on the +// end of the list, which should be ignored. +// +// Requirements for a user of this list: +// +// 1. The user must provide {g|s}et{Next|Prev} methods, or specialize +// ilist_traits to provide an alternate way of getting and setting next and +// prev links. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_ADT_ILIST_H +#define LLVM_ADT_ILIST_H + +#include "llvm/ADT/iterator.h" +#include <cassert> + +namespace llvm { + +template<typename NodeTy, typename Traits> class iplist; +template<typename NodeTy> class ilist_iterator; + +/// ilist_nextprev_traits - A fragment for template traits for intrusive list +/// that provides default next/prev implementations for common operations. +/// +template<typename NodeTy> +struct ilist_nextprev_traits { + static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); } + static NodeTy *getNext(NodeTy *N) { return N->getNext(); } + static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); } + static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); } + + static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); } + static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); } +}; + +template<typename NodeTy> +struct ilist_traits; + +/// ilist_sentinel_traits - A fragment for template traits for intrusive list +/// that provides default sentinel implementations for common operations. +/// +/// ilist_sentinel_traits implements a lazy dynamic sentinel allocation +/// strategy. The sentinel is stored in the prev field of ilist's Head. +/// +template<typename NodeTy> +struct ilist_sentinel_traits { + /// createSentinel - create the dynamic sentinel + static NodeTy *createSentinel() { return new NodeTy(); } + + /// destroySentinel - deallocate the dynamic sentinel + static void destroySentinel(NodeTy *N) { delete N; } + + /// provideInitialHead - when constructing an ilist, provide a starting + /// value for its Head + /// @return null node to indicate that it needs to be allocated later + static NodeTy *provideInitialHead() { return 0; } + + /// ensureHead - make sure that Head is either already + /// initialized or assigned a fresh sentinel + /// @return the sentinel + static NodeTy *ensureHead(NodeTy *&Head) { + if (!Head) { + Head = ilist_traits<NodeTy>::createSentinel(); + ilist_traits<NodeTy>::noteHead(Head, Head); + ilist_traits<NodeTy>::setNext(Head, 0); + return Head; + } + return ilist_traits<NodeTy>::getPrev(Head); + } + + /// noteHead - stash the sentinel into its default location + static void noteHead(NodeTy *NewHead, NodeTy *Sentinel) { + ilist_traits<NodeTy>::setPrev(NewHead, Sentinel); + } +}; + +/// ilist_node_traits - A fragment for template traits for intrusive list +/// that provides default node related operations. +/// +template<typename NodeTy> +struct ilist_node_traits { + static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); } + static void deleteNode(NodeTy *V) { delete V; } + + void addNodeToList(NodeTy *) {} + void removeNodeFromList(NodeTy *) {} + void transferNodesFromList(ilist_node_traits & /*SrcTraits*/, + ilist_iterator<NodeTy> /*first*/, + ilist_iterator<NodeTy> /*last*/) {} +}; + +/// ilist_default_traits - Default template traits for intrusive list. +/// By inheriting from this, you can easily use default implementations +/// for all common operations. +/// +template<typename NodeTy> +struct ilist_default_traits : ilist_nextprev_traits<NodeTy>, + ilist_sentinel_traits<NodeTy>, + ilist_node_traits<NodeTy> { +}; + +// Template traits for intrusive list. By specializing this template class, you +// can change what next/prev fields are used to store the links... +template<typename NodeTy> +struct ilist_traits : ilist_default_traits<NodeTy> {}; + +// Const traits are the same as nonconst traits... +template<typename Ty> +struct ilist_traits<const Ty> : public ilist_traits<Ty> {}; + +//===----------------------------------------------------------------------===// +// ilist_iterator<Node> - Iterator for intrusive list. +// +template<typename NodeTy> +class ilist_iterator + : public bidirectional_iterator<NodeTy, ptrdiff_t> { + +public: + typedef ilist_traits<NodeTy> Traits; + typedef bidirectional_iterator<NodeTy, ptrdiff_t> super; + + typedef typename super::value_type value_type; + typedef typename super::difference_type difference_type; + typedef typename super::pointer pointer; + typedef typename super::reference reference; +private: + pointer NodePtr; + + // ilist_iterator is not a random-access iterator, but it has an + // implicit conversion to pointer-type, which is. Declare (but + // don't define) these functions as private to help catch + // accidental misuse. + void operator[](difference_type) const; + void operator+(difference_type) const; + void operator-(difference_type) const; + void operator+=(difference_type) const; + void operator-=(difference_type) const; + template<class T> void operator<(T) const; + template<class T> void operator<=(T) const; + template<class T> void operator>(T) const; + template<class T> void operator>=(T) const; + template<class T> void operator-(T) const; +public: + + ilist_iterator(pointer NP) : NodePtr(NP) {} + ilist_iterator(reference NR) : NodePtr(&NR) {} + ilist_iterator() : NodePtr(0) {} + + // This is templated so that we can allow constructing a const iterator from + // a nonconst iterator... + template<class node_ty> + ilist_iterator(const ilist_iterator<node_ty> &RHS) + : NodePtr(RHS.getNodePtrUnchecked()) {} + + // This is templated so that we can allow assigning to a const iterator from + // a nonconst iterator... + template<class node_ty> + const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) { + NodePtr = RHS.getNodePtrUnchecked(); + return *this; + } + + // Accessors... + operator pointer() const { + assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!"); + return NodePtr; + } + + reference operator*() const { + assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!"); + return *NodePtr; + } + pointer operator->() const { return &operator*(); } + + // Comparison operators + bool operator==(const ilist_iterator &RHS) const { + return NodePtr == RHS.NodePtr; + } + bool operator!=(const ilist_iterator &RHS) const { + return NodePtr != RHS.NodePtr; + } + + // Increment and decrement operators... + ilist_iterator &operator--() { // predecrement - Back up + NodePtr = Traits::getPrev(NodePtr); + assert(NodePtr && "--'d off the beginning of an ilist!"); + return *this; + } + ilist_iterator &operator++() { // preincrement - Advance + NodePtr = Traits::getNext(NodePtr); + assert(NodePtr && "++'d off the end of an ilist!"); + return *this; + } + ilist_iterator operator--(int) { // postdecrement operators... + ilist_iterator tmp = *this; + --*this; + return tmp; + } + ilist_iterator operator++(int) { // postincrement operators... + ilist_iterator tmp = *this; + ++*this; + return tmp; + } + + // Internal interface, do not use... + pointer getNodePtrUnchecked() const { return NodePtr; } +}; + +// do not implement. this is to catch errors when people try to use +// them as random access iterators +template<typename T> +void operator-(int, ilist_iterator<T>); +template<typename T> +void operator-(ilist_iterator<T>,int); + +template<typename T> +void operator+(int, ilist_iterator<T>); +template<typename T> +void operator+(ilist_iterator<T>,int); + +// operator!=/operator== - Allow mixed comparisons without dereferencing +// the iterator, which could very likely be pointing to end(). +template<typename T> +bool operator!=(const T* LHS, const ilist_iterator<const T> &RHS) { + return LHS != RHS.getNodePtrUnchecked(); +} +template<typename T> +bool operator==(const T* LHS, const ilist_iterator<const T> &RHS) { + return LHS == RHS.getNodePtrUnchecked(); +} +template<typename T> +bool operator!=(T* LHS, const ilist_iterator<T> &RHS) { + return LHS != RHS.getNodePtrUnchecked(); +} +template<typename T> +bool operator==(T* LHS, const ilist_iterator<T> &RHS) { + return LHS == RHS.getNodePtrUnchecked(); +} + + +// Allow ilist_iterators to convert into pointers to a node automatically when +// used by the dyn_cast, cast, isa mechanisms... + +template<typename From> struct simplify_type; + +template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > { + typedef NodeTy* SimpleType; + + static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) { + return &*Node; + } +}; +template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > { + typedef NodeTy* SimpleType; + + static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) { + return &*Node; + } +}; + + +//===----------------------------------------------------------------------===// +// +/// iplist - The subset of list functionality that can safely be used on nodes +/// of polymorphic types, i.e. a heterogenous list with a common base class that +/// holds the next/prev pointers. The only state of the list itself is a single +/// pointer to the head of the list. +/// +/// This list can be in one of three interesting states: +/// 1. The list may be completely unconstructed. In this case, the head +/// pointer is null. When in this form, any query for an iterator (e.g. +/// begin() or end()) causes the list to transparently change to state #2. +/// 2. The list may be empty, but contain a sentinel for the end iterator. This +/// sentinel is created by the Traits::createSentinel method and is a link +/// in the list. When the list is empty, the pointer in the iplist points +/// to the sentinel. Once the sentinel is constructed, it +/// is not destroyed until the list is. +/// 3. The list may contain actual objects in it, which are stored as a doubly +/// linked list of nodes. One invariant of the list is that the predecessor +/// of the first node in the list always points to the last node in the list, +/// and the successor pointer for the sentinel (which always stays at the +/// end of the list) is always null. +/// +template<typename NodeTy, typename Traits=ilist_traits<NodeTy> > +class iplist : public Traits { + mutable NodeTy *Head; + + // Use the prev node pointer of 'head' as the tail pointer. This is really a + // circularly linked list where we snip the 'next' link from the sentinel node + // back to the first node in the list (to preserve assertions about going off + // the end of the list). + NodeTy *getTail() { return this->ensureHead(Head); } + const NodeTy *getTail() const { return this->ensureHead(Head); } + void setTail(NodeTy *N) const { this->noteHead(Head, N); } + + /// CreateLazySentinel - This method verifies whether the sentinel for the + /// list has been created and lazily makes it if not. + void CreateLazySentinel() const { + this->Traits::ensureHead(Head); + } + + static bool op_less(NodeTy &L, NodeTy &R) { return L < R; } + static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; } + + // No fundamental reason why iplist can't by copyable, but the default + // copy/copy-assign won't do. + iplist(const iplist &); // do not implement + void operator=(const iplist &); // do not implement + +public: + typedef NodeTy *pointer; + typedef const NodeTy *const_pointer; + typedef NodeTy &reference; + typedef const NodeTy &const_reference; + typedef NodeTy value_type; + typedef ilist_iterator<NodeTy> iterator; + typedef ilist_iterator<const NodeTy> const_iterator; + typedef size_t size_type; + typedef ptrdiff_t difference_type; + typedef std::reverse_iterator<const_iterator> const_reverse_iterator; + typedef std::reverse_iterator<iterator> reverse_iterator; + + iplist() : Head(this->Traits::provideInitialHead()) {} + ~iplist() { + if (!Head) return; + clear(); + Traits::destroySentinel(getTail()); + } + + // Iterator creation methods. + iterator begin() { + CreateLazySentinel(); + return iterator(Head); + } + const_iterator begin() const { + CreateLazySentinel(); + return const_iterator(Head); + } + iterator end() { + CreateLazySentinel(); + return iterator(getTail()); + } + const_iterator end() const { + CreateLazySentinel(); + return const_iterator(getTail()); + } + + // reverse iterator creation methods. + reverse_iterator rbegin() { return reverse_iterator(end()); } + const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); } + reverse_iterator rend() { return reverse_iterator(begin()); } + const_reverse_iterator rend() const { return const_reverse_iterator(begin());} + + + // Miscellaneous inspection routines. + size_type max_size() const { return size_type(-1); } + bool empty() const { return Head == 0 || Head == getTail(); } + + // Front and back accessor functions... + reference front() { + assert(!empty() && "Called front() on empty list!"); + return *Head; + } + const_reference front() const { + assert(!empty() && "Called front() on empty list!"); + return *Head; + } + reference back() { + assert(!empty() && "Called back() on empty list!"); + return *this->getPrev(getTail()); + } + const_reference back() const { + assert(!empty() && "Called back() on empty list!"); + return *this->getPrev(getTail()); + } + + void swap(iplist &RHS) { + assert(0 && "Swap does not use list traits callback correctly yet!"); + std::swap(Head, RHS.Head); + } + + iterator insert(iterator where, NodeTy *New) { + NodeTy *CurNode = where.getNodePtrUnchecked(); + NodeTy *PrevNode = this->getPrev(CurNode); + this->setNext(New, CurNode); + this->setPrev(New, PrevNode); + + if (CurNode != Head) // Is PrevNode off the beginning of the list? + this->setNext(PrevNode, New); + else + Head = New; + this->setPrev(CurNode, New); + + this->addNodeToList(New); // Notify traits that we added a node... + return New; + } + + iterator insertAfter(iterator where, NodeTy *New) { + if (empty()) + return insert(begin(), New); + else + return insert(++where, New); + } + + NodeTy *remove(iterator &IT) { + assert(IT != end() && "Cannot remove end of list!"); + NodeTy *Node = &*IT; + NodeTy *NextNode = this->getNext(Node); + NodeTy *PrevNode = this->getPrev(Node); + + if (Node != Head) // Is PrevNode off the beginning of the list? + this->setNext(PrevNode, NextNode); + else + Head = NextNode; + this->setPrev(NextNode, PrevNode); + IT = NextNode; + this->removeNodeFromList(Node); // Notify traits that we removed a node... + + // Set the next/prev pointers of the current node to null. This isn't + // strictly required, but this catches errors where a node is removed from + // an ilist (and potentially deleted) with iterators still pointing at it. + // When those iterators are incremented or decremented, they will assert on + // the null next/prev pointer instead of "usually working". + this->setNext(Node, 0); + this->setPrev(Node, 0); + return Node; + } + + NodeTy *remove(const iterator &IT) { + iterator MutIt = IT; + return remove(MutIt); + } + + // erase - remove a node from the controlled sequence... and delete it. + iterator erase(iterator where) { + this->deleteNode(remove(where)); + return where; + } + + +private: + // transfer - The heart of the splice function. Move linked list nodes from + // [first, last) into position. + // + void transfer(iterator position, iplist &L2, iterator first, iterator last) { + assert(first != last && "Should be checked by callers"); + + if (position != last) { + // Note: we have to be careful about the case when we move the first node + // in the list. This node is the list sentinel node and we can't move it. + NodeTy *ThisSentinel = getTail(); + setTail(0); + NodeTy *L2Sentinel = L2.getTail(); + L2.setTail(0); + + // Remove [first, last) from its old position. + NodeTy *First = &*first, *Prev = getPrev(First); + NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next); + if (Prev) + this->setNext(Prev, Next); + else + L2.Head = Next; + this->setPrev(Next, Prev); + + // Splice [first, last) into its new position. + NodeTy *PosNext = position.getNodePtrUnchecked(); + NodeTy *PosPrev = getPrev(PosNext); + + // Fix head of list... + if (PosPrev) + this->setNext(PosPrev, First); + else + Head = First; + this->setPrev(First, PosPrev); + + // Fix end of list... + this->setNext(Last, PosNext); + this->setPrev(PosNext, Last); + + transferNodesFromList(L2, First, PosNext); + + // Now that everything is set, restore the pointers to the list sentinels. + L2.setTail(L2Sentinel); + setTail(ThisSentinel); + } + } + +public: + + //===----------------------------------------------------------------------=== + // Functionality derived from other functions defined above... + // + + size_type size() const { + if (Head == 0) return 0; // Don't require construction of sentinel if empty. + return std::distance(begin(), end()); + } + + iterator erase(iterator first, iterator last) { + while (first != last) + first = erase(first); + return last; + } + + void clear() { if (Head) erase(begin(), end()); } + + // Front and back inserters... + void push_front(NodeTy *val) { insert(begin(), val); } + void push_back(NodeTy *val) { insert(end(), val); } + void pop_front() { + assert(!empty() && "pop_front() on empty list!"); + erase(begin()); + } + void pop_back() { + assert(!empty() && "pop_back() on empty list!"); + iterator t = end(); erase(--t); + } + + // Special forms of insert... + template<class InIt> void insert(iterator where, InIt first, InIt last) { + for (; first != last; ++first) insert(where, *first); + } + + // Splice members - defined in terms of transfer... + void splice(iterator where, iplist &L2) { + if (!L2.empty()) + transfer(where, L2, L2.begin(), L2.end()); + } + void splice(iterator where, iplist &L2, iterator first) { + iterator last = first; ++last; + if (where == first || where == last) return; // No change + transfer(where, L2, first, last); + } + void splice(iterator where, iplist &L2, iterator first, iterator last) { + if (first != last) transfer(where, L2, first, last); + } + + + + //===----------------------------------------------------------------------=== + // High-Level Functionality that shouldn't really be here, but is part of list + // + + // These two functions are actually called remove/remove_if in list<>, but + // they actually do the job of erase, rename them accordingly. + // + void erase(const NodeTy &val) { + for (iterator I = begin(), E = end(); I != E; ) { + iterator next = I; ++next; + if (*I == val) erase(I); + I = next; + } + } + template<class Pr1> void erase_if(Pr1 pred) { + for (iterator I = begin(), E = end(); I != E; ) { + iterator next = I; ++next; + if (pred(*I)) erase(I); + I = next; + } + } + + template<class Pr2> void unique(Pr2 pred) { + if (empty()) return; + for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) { + if (pred(*I)) + erase(Next); + else + I = Next; + Next = I; + } + } + void unique() { unique(op_equal); } + + template<class Pr3> void merge(iplist &right, Pr3 pred) { + iterator first1 = begin(), last1 = end(); + iterator first2 = right.begin(), last2 = right.end(); + while (first1 != last1 && first2 != last2) + if (pred(*first2, *first1)) { + iterator next = first2; + transfer(first1, right, first2, ++next); + first2 = next; + } else { + ++first1; + } + if (first2 != last2) transfer(last1, right, first2, last2); + } + void merge(iplist &right) { return merge(right, op_less); } + + template<class Pr3> void sort(Pr3 pred); + void sort() { sort(op_less); } + void reverse(); +}; + + +template<typename NodeTy> +struct ilist : public iplist<NodeTy> { + typedef typename iplist<NodeTy>::size_type size_type; + typedef typename iplist<NodeTy>::iterator iterator; + + ilist() {} + ilist(const ilist &right) { + insert(this->begin(), right.begin(), right.end()); + } + explicit ilist(size_type count) { + insert(this->begin(), count, NodeTy()); + } + ilist(size_type count, const NodeTy &val) { + insert(this->begin(), count, val); + } + template<class InIt> ilist(InIt first, InIt last) { + insert(this->begin(), first, last); + } + + // bring hidden functions into scope + using iplist<NodeTy>::insert; + using iplist<NodeTy>::push_front; + using iplist<NodeTy>::push_back; + + // Main implementation here - Insert for a node passed by value... + iterator insert(iterator where, const NodeTy &val) { + return insert(where, createNode(val)); + } + + + // Front and back inserters... + void push_front(const NodeTy &val) { insert(this->begin(), val); } + void push_back(const NodeTy &val) { insert(this->end(), val); } + + // Special forms of insert... + template<class InIt> void insert(iterator where, InIt first, InIt last) { + for (; first != last; ++first) insert(where, *first); + } + void insert(iterator where, size_type count, const NodeTy &val) { + for (; count != 0; --count) insert(where, val); + } + + // Assign special forms... + void assign(size_type count, const NodeTy &val) { + iterator I = this->begin(); + for (; I != this->end() && count != 0; ++I, --count) + *I = val; + if (count != 0) + insert(this->end(), val, val); + else + erase(I, this->end()); + } + template<class InIt> void assign(InIt first1, InIt last1) { + iterator first2 = this->begin(), last2 = this->end(); + for ( ; first1 != last1 && first2 != last2; ++first1, ++first2) + *first1 = *first2; + if (first2 == last2) + erase(first1, last1); + else + insert(last1, first2, last2); + } + + + // Resize members... + void resize(size_type newsize, NodeTy val) { + iterator i = this->begin(); + size_type len = 0; + for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ; + + if (len == newsize) + erase(i, this->end()); + else // i == end() + insert(this->end(), newsize - len, val); + } + void resize(size_type newsize) { resize(newsize, NodeTy()); } +}; + +} // End llvm namespace + +namespace std { + // Ensure that swap uses the fast list swap... + template<class Ty> + void swap(llvm::iplist<Ty> &Left, llvm::iplist<Ty> &Right) { + Left.swap(Right); + } +} // End 'std' extensions... + +#endif // LLVM_ADT_ILIST_H |
