- //===- 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 
-