[libbase][adt] Add ilist node base

1 files changed, 167 insertions, 0 deletions

diff --git a/libbase/include/core/adt/ilist_node_base.h b/libbase/include/core/adt/ilist_node_base.h
new file mode 100644
index 0000000..2395efe
--- /dev/null
+++ b/libbase/include/core/adt/ilist_node_base.h
@@ -0,0 +1,167 @@
+//===- core/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 LIBBASE_ADT_ILIST_NODE_BASE_H
+#define LIBBASE_ADT_ILIST_NODE_BASE_H
+
+#include "core/adt/PointerIntPair.h"
+
+namespace libbase
+{
+
+namespace ilist_detail
+{
+
+template <class NodeBase, bool EnableSentinelTracking> class node_base_prevnext;
+
+template <class NodeBase> class node_base_prevnext<NodeBase, false>
+{
+  NodeBase *Prev = nullptr;
+  NodeBase *Next = nullptr;
+
+public:
+  void
+  setPrev (NodeBase *Prev)
+  {
+    this->Prev = Prev;
+  }
+  void
+  setNext (NodeBase *Next)
+  {
+    this->Next = Next;
+  }
+  NodeBase *
+  getPrev () const
+  {
+    return Prev;
+  }
+  NodeBase *
+  getNext () const
+  {
+    return Next;
+  }
+
+  bool
+  isKnownSentinel () const
+  {
+    return false;
+  }
+  void
+  initializeSentinel ()
+  {
+  }
+};
+
+template <class NodeBase> class node_base_prevnext<NodeBase, true>
+{
+  PointerIntPair<NodeBase *, 1> PrevAndSentinel;
+  NodeBase *Next = nullptr;
+
+public:
+  void
+  setPrev (NodeBase *Prev)
+  {
+    PrevAndSentinel.setPointer (Prev);
+  }
+  void
+  setNext (NodeBase *Next)
+  {
+    this->Next = Next;
+  }
+  NodeBase *
+  getPrev () const
+  {
+    return PrevAndSentinel.getPointer ();
+  }
+  NodeBase *
+  getNext () const
+  {
+    return Next;
+  }
+
+  bool
+  isSentinel () const
+  {
+    return PrevAndSentinel.getInt ();
+  }
+  bool
+  isKnownSentinel () const
+  {
+    return isSentinel ();
+  }
+  void
+  initializeSentinel ()
+  {
+    PrevAndSentinel.setInt (true);
+  }
+};
+
+template <class ParentTy> class node_base_parent
+{
+  ParentTy *Parent = nullptr;
+
+public:
+  void
+  setNodeBaseParent (ParentTy *Parent)
+  {
+    this->Parent = Parent;
+  }
+  inline const ParentTy *
+  getNodeBaseParent () const
+  {
+    return Parent;
+  }
+  inline ParentTy *
+  getNodeBaseParent ()
+  {
+    return Parent;
+  }
+};
+template <> class node_base_parent<void>
+{
+};
+
+} // end namespace ilist_detail
+
+/// Base class for ilist nodes.
+///
+/// Optionally tracks whether this node is the sentinel.
+template <bool EnableSentinelTracking, class ParentTy>
+class ilist_node_base : public ilist_detail::node_base_prevnext<
+                            ilist_node_base<EnableSentinelTracking, ParentTy>,
+                            EnableSentinelTracking>,
+                        public ilist_detail::node_base_parent<ParentTy>
+{
+};
+
+// Specialization implemented in the core LLVM library.
+template class LIBBASE_ABI ilist_node_base<true, void>;
+
+} // end namespace libbase
+
+#endif // LIBBASE_ADT_ILIST_NODE_BASE_H
+/*
+ RCC-Project
+
+ Copyright (C) 2026 Richard Qin
+
+ This file is part of RCC-Project.
+
+ RCC-Project is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your option) any
+ later version.
+
+ RCC-Project is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ RCC-Project; see the file COPYING. If not see
+ <http://www.gnu.org/licenses/>.
+*/