//==-- 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
#ifndef LLVM_ADT_ILIST_H
#define LLVM_ADT_ILIST_H
-#include "llvm/ADT/iterator.h"
+#include "llvm/Support/Compiler.h"
+#include <algorithm>
#include <cassert>
-#include <cstdlib>
+#include <cstddef>
+#include <iterator>
namespace llvm {
template<typename NodeTy, typename Traits> class iplist;
template<typename NodeTy> class ilist_iterator;
-// Template traits for intrusive list. By specializing this template class, you
-// can change what next/prev fields are used to store the links...
+/// 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_traits {
+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 void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); }
static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); }
+};
- static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
+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; }
- void addNodeToList(NodeTy *NTy) {}
- void removeNodeFromList(NodeTy *NTy) {}
- void transferNodesFromList(iplist<NodeTy, ilist_traits> &L2,
- ilist_iterator<NodeTy> first,
- ilist_iterator<NodeTy> last) {}
+ /// 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 nullptr; }
+
+ /// 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, nullptr);
+ 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 : public ilist_nextprev_traits<NodeTy>,
+ public ilist_sentinel_traits<NodeTy>,
+ public 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 : public 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> {
- typedef ilist_traits<NodeTy> Traits;
- typedef bidirectional_iterator<NodeTy, ptrdiff_t> super;
+ : public std::iterator<std::bidirectional_iterator_tag, NodeTy, ptrdiff_t> {
public:
- typedef size_t size_type;
+ typedef ilist_traits<NodeTy> Traits;
+ typedef std::iterator<std::bidirectional_iterator_tag,
+ 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) {}
+ ilist_iterator() : NodePtr(nullptr) {}
// This is templated so that we can allow constructing a const iterator from
// a nonconst iterator...
// 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->() { return &operator*(); }
- const pointer operator->() const { return &operator*(); }
+ pointer operator->() const { return &operator*(); }
// Comparison operators
bool operator==(const ilist_iterator &RHS) const {
// Increment and decrement operators...
ilist_iterator &operator--() { // predecrement - Back up
NodePtr = Traits::getPrev(NodePtr);
- assert(Traits::getNext(NodePtr) && "--'d off the beginning of an ilist!");
+ 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...
pointer getNodePtrUnchecked() const { return NodePtr; }
};
-// do not implement. this is to catch errors when people try to use
-// them as random access iterators
+// These are to catch errors when people try to use them as random access
+// iterators.
template<typename T>
-void operator-(int, ilist_iterator<T>);
+void operator-(int, ilist_iterator<T>) = delete;
template<typename T>
-void operator-(ilist_iterator<T>,int);
+void operator-(ilist_iterator<T>,int) = delete;
template<typename T>
-void operator+(int, ilist_iterator<T>);
+void operator+(int, ilist_iterator<T>) = delete;
template<typename T>
-void operator+(ilist_iterator<T>,int);
+void operator+(ilist_iterator<T>,int) = delete;
// operator!=/operator== - Allow mixed comparisons without dereferencing
// the iterator, which could very likely be pointing to end().
template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
typedef NodeTy* SimpleType;
-
- static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
+
+ static SimpleType getSimplifiedValue(ilist_iterator<NodeTy> &Node) {
return &*Node;
}
};
template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
- typedef NodeTy* SimpleType;
-
+ typedef /*const*/ 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
+/// of polymorphic types, i.e. a heterogeneous 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.
///
/// 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 sentinal for the end iterator. This
-/// sentinal is created by the Traits::createSentinel method and is a link
+/// 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 sentinal. Once the sentinal is constructed, it
+/// 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 sentinal (which always stays at the
-/// end of the list) is always null.
+/// 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 {
// 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 getPrev(Head); }
- const NodeTy *getTail() const { return getPrev(Head); }
- void setTail(NodeTy *N) const { setPrev(Head, N); }
-
- /// CreateLazySentinal - This method verifies whether the sentinal for the
+ 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 CreateLazySentinal() const {
- if (Head != 0) return;
- Head = Traits::createSentinel();
- setNext(Head, 0);
- setTail(Head);
+ void CreateLazySentinel() const {
+ this->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
+ // No fundamental reason why iplist can't be copyable, but the default
// copy/copy-assign won't do.
- iplist(const iplist &); // do not implement
- void operator=(const iplist &); // do not implement
+ iplist(const iplist &) = delete;
+ void operator=(const iplist &) = delete;
public:
typedef NodeTy *pointer;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
- iplist() : Head(0) {}
+ iplist() : Head(this->provideInitialHead()) {}
~iplist() {
if (!Head) return;
clear();
// Iterator creation methods.
iterator begin() {
- CreateLazySentinal();
- return iterator(Head);
+ CreateLazySentinel();
+ return iterator(Head);
}
const_iterator begin() const {
- CreateLazySentinal();
+ CreateLazySentinel();
return const_iterator(Head);
}
iterator end() {
- CreateLazySentinal();
+ CreateLazySentinel();
return iterator(getTail());
}
const_iterator end() const {
- CreateLazySentinal();
+ CreateLazySentinel();
return const_iterator(getTail());
}
// Miscellaneous inspection routines.
size_type max_size() const { return size_type(-1); }
- bool empty() const { return Head == 0 || Head == getTail(); }
+ bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const {
+ return !Head || Head == getTail();
+ }
// Front and back accessor functions...
reference front() {
}
reference back() {
assert(!empty() && "Called back() on empty list!");
- return *getPrev(getTail());
+ return *this->getPrev(getTail());
}
const_reference back() const {
assert(!empty() && "Called back() on empty list!");
- return *getPrev(getTail());
+ return *this->getPrev(getTail());
}
void swap(iplist &RHS) {
- abort(); // Swap does not use list traits callback correctly yet!
+ 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(), *PrevNode = getPrev(CurNode);
- setNext(New, CurNode);
- setPrev(New, PrevNode);
+ 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?
- setNext(PrevNode, New);
+ this->setNext(PrevNode, New);
else
Head = New;
- setPrev(CurNode, New);
+ this->setPrev(CurNode, New);
- addNodeToList(New); // Notify traits that we added a node...
+ 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 = getNext(Node);
- NodeTy *PrevNode = getPrev(Node);
+ NodeTy *NextNode = this->getNext(Node);
+ NodeTy *PrevNode = this->getPrev(Node);
if (Node != Head) // Is PrevNode off the beginning of the list?
- setNext(PrevNode, NextNode);
+ this->setNext(PrevNode, NextNode);
else
Head = NextNode;
- setPrev(NextNode, PrevNode);
+ this->setPrev(NextNode, PrevNode);
IT = NextNode;
- removeNodeFromList(Node); // Notify traits that we removed a node...
-
+ 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".
- setNext(Node, 0);
- setPrev(Node, 0);
+ this->setNext(Node, nullptr);
+ this->setPrev(Node, nullptr);
return Node;
}
// erase - remove a node from the controlled sequence... and delete it.
iterator erase(iterator where) {
- delete remove(where);
+ this->deleteNode(remove(where));
return where;
}
+ /// Remove all nodes from the list like clear(), but do not call
+ /// removeNodeFromList() or deleteNode().
+ ///
+ /// This should only be used immediately before freeing nodes in bulk to
+ /// avoid traversing the list and bringing all the nodes into cache.
+ void clearAndLeakNodesUnsafely() {
+ if (Head) {
+ Head = getTail();
+ this->setPrev(Head, Head);
+ }
+ }
private:
// transfer - The heart of the splice function. Move linked list nodes from
//
void transfer(iterator position, iplist &L2, iterator first, iterator last) {
assert(first != last && "Should be checked by callers");
+ // Position cannot be contained in the range to be transferred.
+ // Check for the most common mistake.
+ assert(position != first &&
+ "Insertion point can't be one of the transferred nodes");
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);
+ setTail(nullptr);
NodeTy *L2Sentinel = L2.getTail();
- L2.setTail(0);
+ L2.setTail(nullptr);
// Remove [first, last) from its old position.
- NodeTy *First = &*first, *Prev = getPrev(First);
- NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
+ NodeTy *First = &*first, *Prev = this->getPrev(First);
+ NodeTy *Next = last.getNodePtrUnchecked(), *Last = this->getPrev(Next);
if (Prev)
- setNext(Prev, Next);
+ this->setNext(Prev, Next);
else
L2.Head = Next;
- setPrev(Next, Prev);
+ this->setPrev(Next, Prev);
// Splice [first, last) into its new position.
NodeTy *PosNext = position.getNodePtrUnchecked();
- NodeTy *PosPrev = getPrev(PosNext);
+ NodeTy *PosPrev = this->getPrev(PosNext);
// Fix head of list...
if (PosPrev)
- setNext(PosPrev, First);
+ this->setNext(PosPrev, First);
else
Head = First;
- setPrev(First, PosPrev);
+ this->setPrev(First, PosPrev);
// Fix end of list...
- setNext(Last, PosNext);
- setPrev(PosNext, Last);
+ this->setNext(Last, PosNext);
+ this->setPrev(PosNext, Last);
- transferNodesFromList(L2, First, PosNext);
+ this->transferNodesFromList(L2, First, PosNext);
- // Now that everything is set, restore the pointers to the list sentinals.
+ // Now that everything is set, restore the pointers to the list sentinels.
L2.setTail(L2Sentinel);
setTail(ThisSentinel);
}
// Functionality derived from other functions defined above...
//
- size_type size() const {
- if (Head == 0) return 0; // Don't require construction of sentinal if empty.
-#if __GNUC__ == 2
- // GCC 2.95 has a broken std::distance
- size_type Result = 0;
- std::distance(begin(), end(), Result);
- return Result;
-#else
+ size_type LLVM_ATTRIBUTE_UNUSED_RESULT size() const {
+ if (!Head) return 0; // Don't require construction of sentinel if empty.
return std::distance(begin(), end());
-#endif
}
iterator erase(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 Compare>
+ void merge(iplist &Right, Compare comp) {
+ if (this == &Right)
+ return;
+ iterator First1 = begin(), Last1 = end();
+ iterator First2 = Right.begin(), Last2 = Right.end();
+ while (First1 != Last1 && First2 != Last2) {
+ if (comp(*First2, *First1)) {
+ iterator Next = First2;
+ transfer(First1, Right, First2, ++Next);
+ First2 = Next;
+ } else {
+ ++First1;
+ }
}
- }
- 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;
+ if (First2 != Last2)
+ transfer(Last1, Right, First2, Last2);
+ }
+ void merge(iplist &Right) { return merge(Right, op_less); }
+
+ template <class Compare>
+ void sort(Compare comp) {
+ // The list is empty, vacuously sorted.
+ if (empty())
+ return;
+ // The list has a single element, vacuously sorted.
+ if (std::next(begin()) == end())
+ return;
+ // Find the split point for the list.
+ iterator Center = begin(), End = begin();
+ while (End != end() && std::next(End) != end()) {
+ Center = std::next(Center);
+ End = std::next(std::next(End));
}
- }
+ // Split the list into two.
+ iplist RightHalf;
+ RightHalf.splice(RightHalf.begin(), *this, Center, end());
- 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); }
+ // Sort the two sublists.
+ sort(comp);
+ RightHalf.sort(comp);
- 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);
+ // Merge the two sublists back together.
+ merge(RightHalf, comp);
}
- void merge(iplist &right) { return merge(right, op_less); }
-
- template<class Pr3> void sort(Pr3 pred);
void sort() { sort(op_less); }
- void reverse();
};
}
explicit ilist(size_type count) {
insert(this->begin(), count, NodeTy());
- }
+ }
ilist(size_type count, const NodeTy &val) {
insert(this->begin(), count, val);
}
insert(this->begin(), first, last);
}
-
- // Forwarding functions: A workaround for GCC 2.95 which does not correctly
- // support 'using' declarations to bring a hidden member into scope.
- //
- iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
- void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
- void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
-
+ // 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));
+ return insert(where, this->createNode(val));
}
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);
}
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