AArch64Relocator.h revision a6c24dff8b7fa2551a3a885e77a2e814f5b764a2 
1//===-  AArch64Relocator.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 TARGET_AARCH64_AARCH64RELOCATOR_H_
10#define TARGET_AARCH64_AARCH64RELOCATOR_H_
11
12#include "mcld/LD/Relocator.h"
13#include "mcld/Target/GOT.h"
14#include "mcld/Target/KeyEntryMap.h"
15#include "AArch64LDBackend.h"
16
17namespace mcld {
18
19/** \class AArch64Relocator
20 *  \brief AArch64Relocator creates and destroys the AArch64 relocations.
21 *
22 */
23class AArch64Relocator : public Relocator {
24 public:
25  typedef KeyEntryMap<ResolveInfo, AArch64GOTEntry> SymGOTMap;
26  typedef KeyEntryMap<ResolveInfo, AArch64PLT1> SymPLTMap;
27  typedef KeyEntryMap<Relocation, Relocation> RelRelMap;
28
29  /** \enum ReservedEntryType
30   *  \brief The reserved entry type of reserved space in ResolveInfo.
31   *
32   *  This is used for sacnRelocation to record what kinds of entries are
33   *  reserved for this resolved symbol In AArch64, there are three kinds of
34   *  entries, GOT, PLT, and dynamic reloction.
35   *
36   *  bit:  3     2     1     0
37   *   |    | PLT | GOT | Rel |
38   *
39   *  value    Name         - Description
40   *
41   *  0000     None         - no reserved entry
42   *  0001     ReserveRel   - reserve an dynamic relocation entry
43   *  0010     ReserveGOT   - reserve an GOT entry
44   *  0100     ReservePLT   - reserve an PLT entry and the corresponding GOT,
45   *
46   */
47  enum ReservedEntryType {
48    None = 0,
49    ReserveRel = 1,
50    ReserveGOT = 2,
51    ReservePLT = 4,
52  };
53
54  /** \enum EntryValue
55   *  \brief The value of the entries. The symbol value will be decided at after
56   *  layout, so we mark the entry during scanRelocation and fill up the actual
57   *  value when applying relocations.
58   */
59  enum EntryValue { Default = 0, SymVal = 1 };
60
61 public:
62  AArch64Relocator(AArch64GNULDBackend& pParent, const LinkerConfig& pConfig);
63  ~AArch64Relocator();
64
65  Result applyRelocation(Relocation& pRelocation);
66
67  AArch64GNULDBackend& getTarget() { return m_Target; }
68
69  const AArch64GNULDBackend& getTarget() const { return m_Target; }
70
71  const char* getName(Relocation::Type pType) const;
72
73  Size getSize(Relocation::Type pType) const;
74
75  const SymGOTMap& getSymGOTMap() const { return m_SymGOTMap; }
76  SymGOTMap& getSymGOTMap() { return m_SymGOTMap; }
77
78  const SymPLTMap& getSymPLTMap() const { return m_SymPLTMap; }
79  SymPLTMap& getSymPLTMap() { return m_SymPLTMap; }
80
81  const SymGOTMap& getSymGOTPLTMap() const { return m_SymGOTPLTMap; }
82  SymGOTMap& getSymGOTPLTMap() { return m_SymGOTPLTMap; }
83
84  const RelRelMap& getRelRelMap() const { return m_RelRelMap; }
85  RelRelMap& getRelRelMap() { return m_RelRelMap; }
86
87  /// scanRelocation - determine the empty entries are needed or not and create
88  /// the empty entries if needed.
89  /// For AArch64, following entries are check to create:
90  /// - GOT entry (for .got section)
91  /// - PLT entry (for .plt section)
92  /// - dynamin relocation entries (for .rel.plt and .rel.dyn sections)
93  void scanRelocation(Relocation& pReloc,
94                      IRBuilder& pBuilder,
95                      Module& pModule,
96                      LDSection& pSection,
97                      Input& pInput);
98
99  /// getDebugStringOffset - get the offset from the relocation target. This is
100  /// used to get the debug string offset.
101  uint32_t getDebugStringOffset(Relocation& pReloc) const;
102
103  /// applyDebugStringOffset - apply the relocation target to specific offset.
104  /// This is used to set the debug string offset.
105  void applyDebugStringOffset(Relocation& pReloc, uint32_t pOffset);
106
107 private:
108  void scanLocalReloc(Relocation& pReloc, const LDSection& pSection);
109
110  void scanGlobalReloc(Relocation& pReloc,
111                       IRBuilder& pBuilder,
112                       const LDSection& pSection);
113
114  /// addCopyReloc - add a copy relocation into .rel.dyn for pSym
115  /// @param pSym - A resolved copy symbol that defined in BSS section
116  void addCopyReloc(ResolveInfo& pSym);
117
118  /// defineSymbolforCopyReloc - allocate a space in BSS section and
119  /// and force define the copy of pSym to BSS section
120  /// @return the output LDSymbol of the copy symbol
121  LDSymbol& defineSymbolforCopyReloc(IRBuilder& pLinker,
122                                     const ResolveInfo& pSym);
123
124 private:
125  AArch64GNULDBackend& m_Target;
126  SymGOTMap m_SymGOTMap;
127  SymPLTMap m_SymPLTMap;
128  SymGOTMap m_SymGOTPLTMap;
129  RelRelMap m_RelRelMap;
130};
131
132}  // namespace mcld
133
134#endif  // TARGET_AARCH64_AARCH64RELOCATOR_H_
135