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mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-24 22:32:47 +00:00
llvm-6502/include/llvm/ADT/ilist
Chris Lattner 2896652be2 when a node is removed from an ilist, set its next/prev pointers to
null.  This means that uses of invalidated iterators will explode violently
with:
ilist:143: failed assertion `NodePtr && "++'d off the end of an ilist!"'

instead of happening to work "most of the time".



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48859 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-27 02:43:03 +00:00

635 lines
20 KiB
C++

//===-- llvm/ADT/ilist - 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
// provides 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
#define LLVM_ADT_ILIST
#include "llvm/ADT/iterator"
#include <cassert>
#include <cstdlib>
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...
template<typename NodeTy>
struct ilist_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); }
static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
static NodeTy *createSentinel() { return new NodeTy(); }
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) {}
};
// 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:
typedef size_t size_type;
typedef typename super::pointer pointer;
typedef typename super::reference reference;
private:
pointer NodePtr;
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->() { return &operator*(); }
const 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(Traits::getNext(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 sentinal for the end iterator. This
/// sentinal 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
/// 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.
///
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 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
/// 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);
}
static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
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(0) {}
~iplist() {
if (!Head) return;
clear();
Traits::destroySentinel(getTail());
}
// Iterator creation methods.
iterator begin() {
CreateLazySentinal();
return iterator(Head);
}
const_iterator begin() const {
CreateLazySentinal();
return const_iterator(Head);
}
iterator end() {
CreateLazySentinal();
return iterator(getTail());
}
const_iterator end() const {
CreateLazySentinal();
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 *getPrev(getTail());
}
const_reference back() const {
assert(!empty() && "Called back() on empty list!");
return *getPrev(getTail());
}
void swap(iplist &RHS) {
abort(); // 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);
if (CurNode != Head) // Is PrevNode off the beginning of the list?
setNext(PrevNode, New);
else
Head = New;
setPrev(CurNode, New);
addNodeToList(New); // Notify traits that we added a node...
return New;
}
NodeTy *remove(iterator &IT) {
assert(IT != end() && "Cannot remove end of list!");
NodeTy *Node = &*IT;
NodeTy *NextNode = getNext(Node);
NodeTy *PrevNode = getPrev(Node);
if (Node != Head) // Is PrevNode off the beginning of the list?
setNext(PrevNode, NextNode);
else
Head = NextNode;
setPrev(NextNode, PrevNode);
IT = NextNode;
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);
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) {
delete 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)
setNext(Prev, Next);
else
L2.Head = Next;
setPrev(Next, Prev);
// Splice [first, last) into its new position.
NodeTy *PosNext = position.getNodePtrUnchecked();
NodeTy *PosPrev = getPrev(PosNext);
// Fix head of list...
if (PosPrev)
setNext(PosPrev, First);
else
Head = First;
setPrev(First, PosPrev);
// Fix end of list...
setNext(Last, PosNext);
setPrev(PosNext, Last);
transferNodesFromList(L2, First, PosNext);
// Now that everything is set, restore the pointers to the list sentinals.
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 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
return std::distance(begin(), end());
#endif
}
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);
}
// 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); }
// 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