1//===-  X86Relocator.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_X86_X86RELOCATOR_H_
10#define TARGET_X86_X86RELOCATOR_H_
11
12#include "mcld/LD/Relocator.h"
13#include "mcld/Target/GOT.h"
14#include "mcld/Target/PLT.h"
15#include "mcld/Target/KeyEntryMap.h"
16#include "X86LDBackend.h"
17
18namespace mcld {
19
20class LinkerConfig;
21class ResolveInfo;
22
23/** \class X86Relocator
24 *  \brief X86Relocator creates and destroys the X86 relocations.
25 *
26 */
27class X86Relocator : public Relocator {
28 public:
29  typedef KeyEntryMap<ResolveInfo, PLTEntryBase> SymPLTMap;
30
31  /** \enum ReservedEntryType
32   *  \brief The reserved entry type of reserved space in ResolveInfo.
33   *
34   *  This is used for sacnRelocation to record what kinds of entries are
35   *  reserved for this resolved symbol. In X86, there are three kinds of
36   *  entries, GOT, PLT, and dynamic reloction.
37   *
38   *  bit:  3     2     1     0
39   *   |    | PLT | GOT | Rel |
40   *
41   *  value    Name         - Description
42   *
43   *  0000     None         - no reserved entry
44   *  0001     ReserveRel   - reserve an dynamic relocation entry
45   *  0010     ReserveGOT   - reserve an GOT entry
46   *  0100     ReservePLT   - reserve an PLT entry and the corresponding GOT,
47   *
48   */
49  enum ReservedEntryType {
50    None = 0,
51    ReserveRel = 1,
52    ReserveGOT = 2,
53    ReservePLT = 4,
54  };
55
56  /** \enum EntryValue
57   *  \brief The value of the entries. The symbol value will be decided at after
58   *  layout, so we mark the entry during scanRelocation and fill up the actual
59   *  value when applying relocations.
60   */
61  enum EntryValue { Default = 0, SymVal = 1 };
62
63 public:
64  explicit X86Relocator(const LinkerConfig& pConfig);
65  ~X86Relocator();
66
67  virtual Result applyRelocation(Relocation& pRelocation) = 0;
68
69  virtual const char* getName(Relocation::Type pType) const = 0;
70
71  const SymPLTMap& getSymPLTMap() const { return m_SymPLTMap; }
72  SymPLTMap& getSymPLTMap() { return m_SymPLTMap; }
73
74  /// scanRelocation - determine the empty entries are needed or not and create
75  /// the empty entries if needed.
76  /// For X86, following entries are check to create:
77  /// - GOT entry (for .got and .got.plt sections)
78  /// - PLT entry (for .plt section)
79  /// - dynamin relocation entries (for .rel.plt and .rel.dyn sections)
80  void scanRelocation(Relocation& pReloc,
81                      IRBuilder& pBuilder,
82                      Module& pModule,
83                      LDSection& pSection,
84                      Input& pInput);
85
86 protected:
87  /// addCopyReloc - add a copy relocation into .rel.dyn for pSym
88  /// @param pSym - A resolved copy symbol that defined in BSS section
89  void addCopyReloc(ResolveInfo& pSym, X86GNULDBackend& pTarget);
90
91  /// defineSymbolforCopyReloc - allocate a space in BSS section and
92  /// and force define the copy of pSym to BSS section
93  /// @return the output LDSymbol of the copy symbol
94  LDSymbol& defineSymbolforCopyReloc(IRBuilder& pLinker,
95                                     const ResolveInfo& pSym,
96                                     X86GNULDBackend& pTarget);
97
98 private:
99  virtual void scanLocalReloc(Relocation& pReloc,
100                              IRBuilder& pBuilder,
101                              Module& pModule,
102                              LDSection& pSection) = 0;
103
104  virtual void scanGlobalReloc(Relocation& pReloc,
105                               IRBuilder& pBuilder,
106                               Module& pModule,
107                               LDSection& pSection) = 0;
108
109 private:
110  SymPLTMap m_SymPLTMap;
111};
112
113/** \class X86_32Relocator
114 *  \brief X86_32Relocator creates and destroys the X86-32 relocations.
115 *
116 */
117class X86_32Relocator : public X86Relocator {
118 public:
119  typedef KeyEntryMap<ResolveInfo, X86_32GOTEntry> SymGOTMap;
120  typedef KeyEntryMap<ResolveInfo, X86_32GOTEntry> SymGOTPLTMap;
121
122  enum {
123    R_386_TLS_OPT = 44  // mcld internal relocation type
124  };
125
126 public:
127  X86_32Relocator(X86_32GNULDBackend& pParent, const LinkerConfig& pConfig);
128
129  Result applyRelocation(Relocation& pRelocation);
130
131  X86_32GNULDBackend& getTarget() { return m_Target; }
132
133  const X86_32GNULDBackend& getTarget() const { return m_Target; }
134
135  const char* getName(Relocation::Type pType) const;
136
137  Size getSize(Relocation::Type pType) const;
138
139  const SymGOTMap& getSymGOTMap() const { return m_SymGOTMap; }
140  SymGOTMap& getSymGOTMap() { return m_SymGOTMap; }
141
142  const SymGOTPLTMap& getSymGOTPLTMap() const { return m_SymGOTPLTMap; }
143  SymGOTPLTMap& getSymGOTPLTMap() { return m_SymGOTPLTMap; }
144
145  X86_32GOTEntry& getTLSModuleID();
146
147  /// mayHaveFunctionPointerAccess - check if the given reloc would possibly
148  /// access a function pointer.
149  virtual bool mayHaveFunctionPointerAccess(const Relocation& pReloc) const;
150
151  /// getDebugStringOffset - get the offset from the relocation target. This is
152  /// used to get the debug string offset.
153  uint32_t getDebugStringOffset(Relocation& pReloc) const;
154
155  /// applyDebugStringOffset - apply the relocation target to specific offset.
156  /// This is used to set the debug string offset.
157  void applyDebugStringOffset(Relocation& pReloc, uint32_t pOffset);
158
159 private:
160  void scanLocalReloc(Relocation& pReloc,
161                      IRBuilder& pBuilder,
162                      Module& pModule,
163                      LDSection& pSection);
164
165  void scanGlobalReloc(Relocation& pReloc,
166                       IRBuilder& pBuilder,
167                       Module& pModule,
168                       LDSection& pSection);
169
170  /// -----  tls optimization  ----- ///
171  /// convert R_386_TLS_IE to R_386_TLS_LE
172  void convertTLSIEtoLE(Relocation& pReloc, LDSection& pSection);
173
174 private:
175  X86_32GNULDBackend& m_Target;
176  SymGOTMap m_SymGOTMap;
177  SymGOTPLTMap m_SymGOTPLTMap;
178};
179
180/** \class X86_64Relocator
181 *  \brief X86_64Relocator creates and destroys the X86-64 relocations.
182 *
183 */
184class X86_64Relocator : public X86Relocator {
185 public:
186  typedef KeyEntryMap<ResolveInfo, X86_64GOTEntry> SymGOTMap;
187  typedef KeyEntryMap<ResolveInfo, X86_64GOTEntry> SymGOTPLTMap;
188  typedef KeyEntryMap<Relocation, Relocation> RelRelMap;
189
190 public:
191  X86_64Relocator(X86_64GNULDBackend& pParent, const LinkerConfig& pConfig);
192
193  Result applyRelocation(Relocation& pRelocation);
194
195  X86_64GNULDBackend& getTarget() { return m_Target; }
196
197  const X86_64GNULDBackend& getTarget() const { return m_Target; }
198
199  const char* getName(Relocation::Type pType) const;
200
201  Size getSize(Relocation::Type pType) const;
202
203  const SymGOTMap& getSymGOTMap() const { return m_SymGOTMap; }
204  SymGOTMap& getSymGOTMap() { return m_SymGOTMap; }
205
206  const SymGOTPLTMap& getSymGOTPLTMap() const { return m_SymGOTPLTMap; }
207  SymGOTPLTMap& getSymGOTPLTMap() { return m_SymGOTPLTMap; }
208
209  const RelRelMap& getRelRelMap() const { return m_RelRelMap; }
210  RelRelMap& getRelRelMap() { return m_RelRelMap; }
211
212  /// mayHaveFunctionPointerAccess - check if the given reloc would possibly
213  /// access a function pointer.
214  virtual bool mayHaveFunctionPointerAccess(const Relocation& pReloc) const;
215
216  /// getDebugStringOffset - get the offset from the relocation target. This is
217  /// used to get the debug string offset.
218  uint32_t getDebugStringOffset(Relocation& pReloc) const;
219
220  /// applyDebugStringOffset - apply the relocation target to specific offset.
221  /// This is used to set the debug string offset.
222  void applyDebugStringOffset(Relocation& pReloc, uint32_t pOffset);
223
224 private:
225  void scanLocalReloc(Relocation& pReloc,
226                      IRBuilder& pBuilder,
227                      Module& pModule,
228                      LDSection& pSection);
229
230  void scanGlobalReloc(Relocation& pReloc,
231                       IRBuilder& pBuilder,
232                       Module& pModule,
233                       LDSection& pSection);
234
235 private:
236  X86_64GNULDBackend& m_Target;
237  SymGOTMap m_SymGOTMap;
238  SymGOTPLTMap m_SymGOTPLTMap;
239  RelRelMap m_RelRelMap;
240};
241
242}  // namespace mcld
243
244#endif  // TARGET_X86_X86RELOCATOR_H_
245