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// FIXME: llvm::ELF doesn't define AArch64 dynamic relocation types
19enum {
20  // static relocations
21  R_AARCH64_ADR_PREL_PG_HI21_NC = 0x114,
22  // dyanmic rlocations
23  R_AARCH64_COPY                = 1024,
24  R_AARCH64_GLOB_DAT            = 1025,
25  R_AARCH64_JUMP_SLOT           = 1026,
26  R_AARCH64_RELATIVE            = 1027,
27  R_AARCH64_TLS_DTPREL64        = 1028,
28  R_AARCH64_TLS_DTPMOD64        = 1029,
29  R_AARCH64_TLS_TPREL64         = 1030,
30  R_AARCH64_TLSDESC             = 1031,
31  R_AARCH64_IRELATIVE           = 1032
32};
33
34/** \class AArch64Relocator
35 *  \brief AArch64Relocator creates and destroys the AArch64 relocations.
36 *
37 */
38class AArch64Relocator : public Relocator
39{
40public:
41  typedef KeyEntryMap<ResolveInfo, AArch64GOTEntry> SymGOTMap;
42  typedef KeyEntryMap<ResolveInfo, AArch64PLT1> SymPLTMap;
43  typedef KeyEntryMap<Relocation, Relocation> RelRelMap;
44
45  /** \enum ReservedEntryType
46   *  \brief The reserved entry type of reserved space in ResolveInfo.
47   *
48   *  This is used for sacnRelocation to record what kinds of entries are
49   *  reserved for this resolved symbol In AArch64, there are three kinds of
50   *  entries, GOT, PLT, and dynamic reloction.
51   *
52   *  bit:  3     2     1     0
53   *   |    | PLT | GOT | Rel |
54   *
55   *  value    Name         - Description
56   *
57   *  0000     None         - no reserved entry
58   *  0001     ReserveRel   - reserve an dynamic relocation entry
59   *  0010     ReserveGOT   - reserve an GOT entry
60   *  0100     ReservePLT   - reserve an PLT entry and the corresponding GOT,
61   *
62   */
63  enum ReservedEntryType {
64    None         = 0,
65    ReserveRel   = 1,
66    ReserveGOT   = 2,
67    ReservePLT   = 4,
68  };
69
70  /** \enum EntryValue
71   *  \brief The value of the entries. The symbol value will be decided at after
72   *  layout, so we mark the entry during scanRelocation and fill up the actual
73   *  value when applying relocations.
74   */
75  enum EntryValue {
76    Default = 0,
77    SymVal  = 1
78  };
79
80public:
81  AArch64Relocator(AArch64GNULDBackend& pParent, const LinkerConfig& pConfig);
82  ~AArch64Relocator();
83
84  Result applyRelocation(Relocation& pRelocation);
85
86  AArch64GNULDBackend& getTarget()
87  { return m_Target; }
88
89  const AArch64GNULDBackend& getTarget() const
90  { return m_Target; }
91
92  const char* getName(Relocation::Type pType) const;
93
94  Size getSize(Relocation::Type pType) const;
95
96  const SymGOTMap& getSymGOTMap() const { return m_SymGOTMap; }
97  SymGOTMap&       getSymGOTMap()       { return m_SymGOTMap; }
98
99  const SymPLTMap& getSymPLTMap() const { return m_SymPLTMap; }
100  SymPLTMap&       getSymPLTMap()       { return m_SymPLTMap; }
101
102  const SymGOTMap& getSymGOTPLTMap() const { return m_SymGOTPLTMap; }
103  SymGOTMap&       getSymGOTPLTMap()       { return m_SymGOTPLTMap; }
104
105  const RelRelMap& getRelRelMap() const { return m_RelRelMap; }
106  RelRelMap&       getRelRelMap()       { return m_RelRelMap; }
107
108  /// scanRelocation - determine the empty entries are needed or not and create
109  /// the empty entries if needed.
110  /// For AArch64, following entries are check to create:
111  /// - GOT entry (for .got section)
112  /// - PLT entry (for .plt section)
113  /// - dynamin relocation entries (for .rel.plt and .rel.dyn sections)
114  void scanRelocation(Relocation& pReloc,
115                      IRBuilder& pBuilder,
116                      Module& pModule,
117                      LDSection& pSection,
118                      Input& pInput);
119
120private:
121  void scanLocalReloc(Relocation& pReloc, const LDSection& pSection);
122
123  void scanGlobalReloc(Relocation& pReloc,
124                       IRBuilder& pBuilder,
125                       const LDSection& pSection);
126
127  /// addCopyReloc - add a copy relocation into .rel.dyn for pSym
128  /// @param pSym - A resolved copy symbol that defined in BSS section
129  void addCopyReloc(ResolveInfo& pSym);
130
131  /// defineSymbolforCopyReloc - allocate a space in BSS section and
132  /// and force define the copy of pSym to BSS section
133  /// @return the output LDSymbol of the copy symbol
134  LDSymbol& defineSymbolforCopyReloc(IRBuilder& pLinker,
135                                     const ResolveInfo& pSym);
136
137private:
138  AArch64GNULDBackend& m_Target;
139  SymGOTMap m_SymGOTMap;
140  SymPLTMap m_SymPLTMap;
141  SymGOTMap m_SymGOTPLTMap;
142  RelRelMap m_RelRelMap;
143};
144
145} // namespace of mcld
146
147#endif
148
149