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//===- llvm/ADT/ilist_node_base.h - Intrusive List Node Base -----*- C++ -*-==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_ILIST_NODE_BASE_H
#define LLVM_ADT_ILIST_NODE_BASE_H
#include "llvm/ADT/PointerIntPair.h"
namespace llvm {
/// Base class for ilist nodes.
///
/// Optionally tracks whether this node is the sentinel.
template <bool EnableSentinelTracking> class ilist_node_base;
template <> class ilist_node_base<false> {
ilist_node_base *Prev = nullptr;
ilist_node_base *Next = nullptr;
public:
void setPrev(ilist_node_base *Prev) { this->Prev = Prev; }
void setNext(ilist_node_base *Next) { this->Next = Next; }
ilist_node_base *getPrev() const { return Prev; }
ilist_node_base *getNext() const { return Next; }
bool isKnownSentinel() const { return false; }
void initializeSentinel() {}
};
template <> class ilist_node_base<true> {
PointerIntPair<ilist_node_base *, 1> PrevAndSentinel;
ilist_node_base *Next = nullptr;
public:
void setPrev(ilist_node_base *Prev) { PrevAndSentinel.setPointer(Prev); }
void setNext(ilist_node_base *Next) { this->Next = Next; }
ilist_node_base *getPrev() const { return PrevAndSentinel.getPointer(); }
ilist_node_base *getNext() const { return Next; }
bool isSentinel() const { return PrevAndSentinel.getInt(); }
bool isKnownSentinel() const { return isSentinel(); }
void initializeSentinel() { PrevAndSentinel.setInt(true); }
};
} // end namespace llvm
#endif // LLVM_ADT_ILIST_NODE_BASE_H