1 | //===- llvm/ADT/ilist_node_base.h - Intrusive List Node Base -----*- C++ -*-==// |
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2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #ifndef LLVM_ADT_ILIST_NODE_BASE_H |
10 | #define LLVM_ADT_ILIST_NODE_BASE_H |
11 | |
12 | #include "llvm/ADT/PointerIntPair.h" |
13 | |
14 | namespace llvm { |
15 | |
16 | /// Base class for ilist nodes. |
17 | /// |
18 | /// Optionally tracks whether this node is the sentinel. |
19 | template <bool EnableSentinelTracking> class ilist_node_base; |
20 | |
21 | template <> class ilist_node_base<false> { |
22 | ilist_node_base *Prev = nullptr; |
23 | ilist_node_base *Next = nullptr; |
24 | |
25 | public: |
26 | void setPrev(ilist_node_base *Prev) { this->Prev = Prev; } |
27 | void setNext(ilist_node_base *Next) { this->Next = Next; } |
28 | ilist_node_base *getPrev() const { return Prev; } |
29 | ilist_node_base *getNext() const { return Next; } |
30 | |
31 | bool isKnownSentinel() const { return false; } |
32 | void initializeSentinel() {} |
33 | }; |
34 | |
35 | template <> class ilist_node_base<true> { |
36 | PointerIntPair<ilist_node_base *, 1> PrevAndSentinel; |
37 | ilist_node_base *Next = nullptr; |
38 | |
39 | public: |
40 | void setPrev(ilist_node_base *Prev) { PrevAndSentinel.setPointer(Prev); } |
41 | void setNext(ilist_node_base *Next) { this->Next = Next; } |
42 | ilist_node_base *getPrev() const { return PrevAndSentinel.getPointer(); } |
43 | ilist_node_base *getNext() const { return Next; } |
44 | |
45 | bool isSentinel() const { return PrevAndSentinel.getInt(); } |
46 | bool isKnownSentinel() const { return isSentinel(); } |
47 | void initializeSentinel() { PrevAndSentinel.setInt(true); } |
48 | }; |
49 | |
50 | } // end namespace llvm |
51 | |
52 | #endif // LLVM_ADT_ILIST_NODE_BASE_H |
53 |