GCFactoryListTraits.h revision 5460a1f25d9ddecb5c70667267d66d51af177a99 
1//===- GCFactoryListTraits.h ----------------------------------------------===//
2//
3//                     The MCLinker Project
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9#ifndef MCLD_GC_FACTORY_LIST_TRAITS_H
10#define MCLD_GC_FACTORY_LIST_TRAITS_H
11#ifdef ENABLE_UNITTEST
12#include <gtest.h>
13#endif
14
15#include <llvm/ADT/ilist_node.h>
16#include <llvm/ADT/ilist.h>
17
18#include <assert.h>
19
20namespace mcld
21{
22
23/** \class GCFactoryListTraits
24 *  \brief GCFactoryListTraits provides trait class for llvm::iplist when
25 *  the nodes in the list is produced by GCFactory.
26 */
27template<typename DataType>
28class GCFactoryListTraits : public llvm::ilist_default_traits<DataType> {
29private:
30  class SentinelNode : public llvm::ilist_node<DataType> {
31  public:
32    SentinelNode() : llvm::ilist_node<DataType>() { }
33  };
34
35public:
36  // override the traits provided in llvm::ilist_sentinel_traits since we've
37  // defined our own sentinel.
38  DataType *createSentinel() const
39  { return reinterpret_cast<DataType*>(&mSentinel); }
40
41  static void destroySentinel(DataType*) { }
42
43  DataType *provideInitialHead() const
44  { return createSentinel(); }
45
46  DataType *ensureHead(DataType*) const
47  { return createSentinel(); }
48
49  static void noteHead(DataType*, DataType*) { }
50
51  // override the traits provided in llvm::ilist_node_traits since
52  static DataType *createNode(const DataType &V) {
53    assert(false && "Only GCFactory knows how to create a node.");
54  }
55  static void deleteNode(DataType *V) {
56    // No action. GCFactory will handle it by itself.
57  }
58
59private:
60  mutable SentinelNode mSentinel;
61};
62
63} // namespace of mcld
64
65#endif
66