Resolver.h revision 37b74a387bb3993387029859c2d9d051c41c724e 
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_LD_RESOLVER_H_
10#define MCLD_LD_RESOLVER_H_
11#include "mcld/LD/LDSymbol.h"
12
13#include <string>
14#include <utility>
15
16namespace mcld {
17
18class NamePool;
19class ResolveInfo;
20
21/** \class Resolver
22 *  \brief Resolver binds a symbol reference from one file to a symbol
23 *   definition of another file.
24 *
25 *  Resolver seals up the algorithm of symbol resolution. The resolution of
26 *  two symbols depends on their type, binding and whether it is belonging to
27 *  a shared object.
28 */
29class Resolver {
30 public:
31  enum Action { Success, Warning, Abort, LastAction };
32
33  /** \class Resolver::Result
34   *  \brief the result of symbol resolution
35   *   - info, the pointer to overrided info
36   *   - existent, if true, the info is existent
37   *   - overriden, if true, the info is being overriden.
38   */
39  struct Result {
40    ResolveInfo* info;
41    bool existent;
42    bool overriden;
43  };
44
45 public:
46  virtual ~Resolver();
47
48  /// shouldOverride - Can resolver override the symbol pOld by the symbol pNew?
49  /// @return the action should be taken.
50  /// @param pOld the symbol which may be overridden.
51  /// @param pNew the symbol which is used to replace pOld
52  virtual bool resolve(ResolveInfo& __restrict__ pOld,
53                       const ResolveInfo& __restrict__ pNew,
54                       bool& pOverride,
55                       LDSymbol::ValueType pValue) const = 0;
56
57  /// resolveAgain - Can override by derived classes.
58  /// @return the pointer to resolved ResolveInfo
59  /// @return is the symbol existent?
60  virtual void resolveAgain(NamePool& pNamePool,
61                            unsigned int pAction,
62                            ResolveInfo& __restrict__ pOld,
63                            const ResolveInfo& __restrict__ pNew,
64                            Result& pResult) const {
65    pResult.info = NULL;
66    pResult.existent = false;
67    pResult.overriden = false;
68  }
69};
70
71}  // namespace mcld
72
73#endif  // MCLD_LD_RESOLVER_H_
74