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//===- llvm/ADT/ilist_base.h - Intrusive List 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_BASE_H
#define LLVM_ADT_ILIST_BASE_H
#include "llvm/ADT/ilist_node_base.h"
#include <cassert>
namespace llvm {
/// Implementations of list algorithms using ilist_node_base.
template <bool EnableSentinelTracking> class ilist_base {
public:
using node_base_type = ilist_node_base<EnableSentinelTracking>;
static void insertBeforeImpl(node_base_type &Next, node_base_type &N) {
node_base_type &Prev = *Next.getPrev();
N.setNext(&Next);
N.setPrev(&Prev);
Prev.setNext(&N);
Next.setPrev(&N);
}
static void removeImpl(node_base_type &N) {
node_base_type *Prev = N.getPrev();
node_base_type *Next = N.getNext();
Next->setPrev(Prev);
Prev->setNext(Next);
// Not strictly necessary, but helps catch a class of bugs.
N.setPrev(nullptr);
N.setNext(nullptr);
}
static void removeRangeImpl(node_base_type &First, node_base_type &Last) {
node_base_type *Prev = First.getPrev();
node_base_type *Final = Last.getPrev();
Last.setPrev(Prev);
Prev->setNext(&Last);
// Not strictly necessary, but helps catch a class of bugs.
First.setPrev(nullptr);
Final->setNext(nullptr);
}
static void transferBeforeImpl(node_base_type &Next, node_base_type &First,
node_base_type &Last) {
if (&Next == &Last || &First == &Last)
return;
// Position cannot be contained in the range to be transferred.
assert(&Next != &First &&
// Check for the most common mistake.
"Insertion point can't be one of the transferred nodes");
node_base_type &Final = *Last.getPrev();
// Detach from old list/position.
First.getPrev()->setNext(&Last);
Last.setPrev(First.getPrev());
// Splice [First, Final] into its new list/position.
node_base_type &Prev = *Next.getPrev();
Final.setNext(&Next);
First.setPrev(&Prev);
Prev.setNext(&First);
Next.setPrev(&Final);
}
template <class T> static void insertBefore(T &Next, T &N) {
insertBeforeImpl(Next, N);
}
template <class T> static void remove(T &N) { removeImpl(N); }
template <class T> static void removeRange(T &First, T &Last) {
removeRangeImpl(First, Last);
}
template <class T> static void transferBefore(T &Next, T &First, T &Last) {
transferBeforeImpl(Next, First, Last);
}
};
} // end namespace llvm
#endif // LLVM_ADT_ILIST_BASE_H