Resolver.h revision affc150dc44fab1911775a49636d0ce85333b634 
1//===- Resolver.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_SYMBOL_RESOLVER_H
10#define MCLD_SYMBOL_RESOLVER_H
11#ifdef ENABLE_UNITTEST
12#include <gtest.h>
13#endif
14#include <string>
15#include <utility>
16
17namespace mcld
18{
19
20class ResolveInfo;
21class NamePool;
22
23/** \class Resolver
24 *  \brief Resolver binds a symbol reference from one file to a symbol
25 *   definition of another file.
26 *
27 *  Resolver seals up the algorithm of symbol resolution. The resolution of
28 *  two symbols depends on their type, binding and whether it is belonging to
29 *  a shared object.
30 */
31class Resolver
32{
33public:
34  enum Action {
35    Success,
36    Warning,
37    Abort,
38    LastAction
39  };
40
41  /** \class Resolver::Result
42   *  \brief the result of symbol resolution
43   *   - info, the pointer to overrided info
44   *   - existent, if true, the info is existent
45   *   - overriden, if true, the info is being overriden.
46   */
47  struct Result {
48    ResolveInfo* info;
49    bool existent;
50    bool overriden;
51  };
52
53public:
54  virtual ~Resolver();
55
56  /// shouldOverride - Can resolver override the symbol pOld by the symbol pNew?
57  /// @return the action should be taken.
58  /// @param pOld the symbol which may be overridden.
59  /// @param pNew the symbol which is used to replace pOld
60  virtual bool resolve(ResolveInfo & __restrict__ pOld,
61                       const ResolveInfo & __restrict__ pNew,
62                       bool &pOverride) const = 0;
63
64  /// resolveAgain - Can override by derived classes.
65  /// @return the pointer to resolved ResolveInfo
66  /// @return is the symbol existent?
67  virtual void resolveAgain(NamePool& pNamePool,
68                              unsigned int pAction,
69                              ResolveInfo& __restrict__ pOld,
70                              const ResolveInfo& __restrict__ pNew,
71                              Result& pResult) const {
72    pResult.info = NULL;
73    pResult.existent = false;
74    pResult.overriden = false;
75  }
76
77};
78
79} // namespace of mcld
80
81#endif
82
83