1//==-- llvm/ADT/ilist_node.h - Intrusive Linked List Helper ------*- C++ -*-==// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines the ilist_node class template, which is a convenient 11// base class for creating classes that can be used with ilists. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_ADT_ILIST_NODE_H 16#define LLVM_ADT_ILIST_NODE_H 17 18namespace llvm { 19 20template<typename NodeTy> 21struct ilist_traits; 22 23/// ilist_half_node - Base class that provides prev services for sentinels. 24/// 25template<typename NodeTy> 26class ilist_half_node { 27 friend struct ilist_traits<NodeTy>; 28 NodeTy *Prev; 29protected: 30 NodeTy *getPrev() { return Prev; } 31 const NodeTy *getPrev() const { return Prev; } 32 void setPrev(NodeTy *P) { Prev = P; } 33 ilist_half_node() : Prev(nullptr) {} 34}; 35 36template<typename NodeTy> 37struct ilist_nextprev_traits; 38 39/// ilist_node - Base class that provides next/prev services for nodes 40/// that use ilist_nextprev_traits or ilist_default_traits. 41/// 42template<typename NodeTy> 43class ilist_node : private ilist_half_node<NodeTy> { 44 friend struct ilist_nextprev_traits<NodeTy>; 45 friend struct ilist_traits<NodeTy>; 46 NodeTy *Next; 47 NodeTy *getNext() { return Next; } 48 const NodeTy *getNext() const { return Next; } 49 void setNext(NodeTy *N) { Next = N; } 50protected: 51 ilist_node() : Next(nullptr) {} 52 53public: 54 /// @name Adjacent Node Accessors 55 /// @{ 56 57 /// \brief Get the previous node, or 0 for the list head. 58 NodeTy *getPrevNode() { 59 NodeTy *Prev = this->getPrev(); 60 61 // Check for sentinel. 62 if (!Prev->getNext()) 63 return nullptr; 64 65 return Prev; 66 } 67 68 /// \brief Get the previous node, or 0 for the list head. 69 const NodeTy *getPrevNode() const { 70 const NodeTy *Prev = this->getPrev(); 71 72 // Check for sentinel. 73 if (!Prev->getNext()) 74 return nullptr; 75 76 return Prev; 77 } 78 79 /// \brief Get the next node, or 0 for the list tail. 80 NodeTy *getNextNode() { 81 NodeTy *Next = getNext(); 82 83 // Check for sentinel. 84 if (!Next->getNext()) 85 return nullptr; 86 87 return Next; 88 } 89 90 /// \brief Get the next node, or 0 for the list tail. 91 const NodeTy *getNextNode() const { 92 const NodeTy *Next = getNext(); 93 94 // Check for sentinel. 95 if (!Next->getNext()) 96 return nullptr; 97 98 return Next; 99 } 100 101 /// @} 102}; 103 104} // End llvm namespace 105 106#endif 107