X86Relocator.h revision 0dea6bc96bb52346737966839ac68644f7939f58 
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 ResolveInfo;
21class LinkerConfig;
22
23/** \class X86Relocator
24 *  \brief X86Relocator creates and destroys the X86 relocations.
25 *
26 */
27class X86Relocator : public Relocator
28{
29public:
30  typedef KeyEntryMap<ResolveInfo, PLTEntryBase> SymPLTMap;
31
32  /** \enum ReservedEntryType
33   *  \brief The reserved entry type of reserved space in ResolveInfo.
34   *
35   *  This is used for sacnRelocation to record what kinds of entries are
36   *  reserved for this resolved symbol. In X86, there are three kinds of
37   *  entries, GOT, PLT, and dynamic reloction.
38   *
39   *  bit:  3     2     1     0
40   *   |    | PLT | GOT | Rel |
41   *
42   *  value    Name         - Description
43   *
44   *  0000     None         - no reserved entry
45   *  0001     ReserveRel   - reserve an dynamic relocation entry
46   *  0010     ReserveGOT   - reserve an GOT entry
47   *  0100     ReservePLT   - reserve an PLT entry and the corresponding GOT,
48   *
49   */
50  enum ReservedEntryType {
51    None         = 0,
52    ReserveRel   = 1,
53    ReserveGOT   = 2,
54    ReservePLT   = 4,
55  };
56
57  /** \enum EntryValue
58   *  \brief The value of the entries. The symbol value will be decided at after
59   *  layout, so we mark the entry during scanRelocation and fill up the actual
60   *  value when applying relocations.
61   */
62  enum EntryValue {
63    Default = 0,
64    SymVal  = 1
65  };
66
67public:
68  X86Relocator(const LinkerConfig& pConfig);
69  ~X86Relocator();
70
71  virtual Result applyRelocation(Relocation& pRelocation) = 0;
72
73  virtual const char* getName(Relocation::Type pType) const = 0;
74
75  const SymPLTMap& getSymPLTMap() const { return m_SymPLTMap; }
76  SymPLTMap&       getSymPLTMap()       { return m_SymPLTMap; }
77
78  /// scanRelocation - determine the empty entries are needed or not and create
79  /// the empty entries if needed.
80  /// For X86, following entries are check to create:
81  /// - GOT entry (for .got and .got.plt sections)
82  /// - PLT entry (for .plt section)
83  /// - dynamin relocation entries (for .rel.plt and .rel.dyn sections)
84  void scanRelocation(Relocation& pReloc,
85                      IRBuilder& pBuilder,
86                      Module& pModule,
87                      LDSection& pSection,
88                      Input& pInput);
89
90protected:
91  /// addCopyReloc - add a copy relocation into .rel.dyn for pSym
92  /// @param pSym - A resolved copy symbol that defined in BSS section
93  void addCopyReloc(ResolveInfo& pSym, X86GNULDBackend& pTarget);
94
95  /// defineSymbolforCopyReloc - allocate a space in BSS section and
96  /// and force define the copy of pSym to BSS section
97  /// @return the output LDSymbol of the copy symbol
98  LDSymbol& defineSymbolforCopyReloc(IRBuilder& pLinker,
99                                     const ResolveInfo& pSym,
100                                     X86GNULDBackend& pTarget);
101
102private:
103  virtual void scanLocalReloc(Relocation& pReloc,
104                              IRBuilder& pBuilder,
105                              Module& pModule,
106                              LDSection& pSection) = 0;
107
108  virtual void scanGlobalReloc(Relocation& pReloc,
109                               IRBuilder& pBuilder,
110                               Module& pModule,
111                               LDSection& pSection) = 0;
112
113private:
114  SymPLTMap m_SymPLTMap;
115};
116
117/** \class X86_32Relocator
118 *  \brief X86_32Relocator creates and destroys the X86-32 relocations.
119 *
120 */
121class X86_32Relocator : public X86Relocator
122{
123public:
124  typedef KeyEntryMap<ResolveInfo, X86_32GOTEntry> SymGOTMap;
125  typedef KeyEntryMap<ResolveInfo, X86_32GOTEntry> SymGOTPLTMap;
126
127  enum {
128    R_386_TLS_OPT = 44 // mcld internal relocation type
129  };
130
131public:
132  X86_32Relocator(X86_32GNULDBackend& pParent, const LinkerConfig& pConfig);
133
134  Result applyRelocation(Relocation& pRelocation);
135
136  X86_32GNULDBackend& getTarget()
137  { return m_Target; }
138
139  const X86_32GNULDBackend& getTarget() const
140  { return m_Target; }
141
142  const char* getName(Relocation::Type pType) const;
143
144  Size getSize(Relocation::Type pType) const;
145
146  const SymGOTMap& getSymGOTMap() const { return m_SymGOTMap; }
147  SymGOTMap&       getSymGOTMap()       { return m_SymGOTMap; }
148
149  const SymGOTPLTMap& getSymGOTPLTMap() const { return m_SymGOTPLTMap; }
150  SymGOTPLTMap&       getSymGOTPLTMap()       { return m_SymGOTPLTMap; }
151
152  X86_32GOTEntry& getTLSModuleID();
153
154  /// mayHaveFunctionPointerAccess - check if the given reloc would possibly
155  /// access a function pointer.
156  virtual bool mayHaveFunctionPointerAccess(const Relocation& pReloc) const;
157
158private:
159  void scanLocalReloc(Relocation& pReloc,
160                      IRBuilder& pBuilder,
161                      Module& pModule,
162                      LDSection& pSection);
163
164  void scanGlobalReloc(Relocation& pReloc,
165                       IRBuilder& pBuilder,
166                       Module& pModule,
167                       LDSection& pSection);
168
169  /// -----  tls optimization  ----- ///
170  /// convert R_386_TLS_IE to R_386_TLS_LE
171  void convertTLSIEtoLE(Relocation& pReloc, LDSection& pSection);
172
173private:
174  X86_32GNULDBackend& m_Target;
175  SymGOTMap m_SymGOTMap;
176  SymGOTPLTMap m_SymGOTPLTMap;
177};
178
179/** \class X86_64Relocator
180 *  \brief X86_64Relocator creates and destroys the X86-64 relocations.
181 *
182 */
183class X86_64Relocator : public X86Relocator
184{
185public:
186  typedef KeyEntryMap<ResolveInfo, X86_64GOTEntry> SymGOTMap;
187  typedef KeyEntryMap<ResolveInfo, X86_64GOTEntry> SymGOTPLTMap;
188  typedef KeyEntryMap<Relocation, Relocation> RelRelMap;
189
190public:
191  X86_64Relocator(X86_64GNULDBackend& pParent, const LinkerConfig& pConfig);
192
193  Result applyRelocation(Relocation& pRelocation);
194
195  X86_64GNULDBackend& getTarget()
196  { return m_Target; }
197
198  const X86_64GNULDBackend& getTarget() const
199  { return m_Target; }
200
201  const char* getName(Relocation::Type pType) const;
202
203  Size getSize(Relocation::Type pType) const;
204
205  const SymGOTMap& getSymGOTMap() const { return m_SymGOTMap; }
206  SymGOTMap&       getSymGOTMap()       { return m_SymGOTMap; }
207
208  const SymGOTPLTMap& getSymGOTPLTMap() const { return m_SymGOTPLTMap; }
209  SymGOTPLTMap&       getSymGOTPLTMap()       { return m_SymGOTPLTMap; }
210
211  const RelRelMap& getRelRelMap() const { return m_RelRelMap; }
212  RelRelMap&       getRelRelMap()       { return m_RelRelMap; }
213
214  /// mayHaveFunctionPointerAccess - check if the given reloc would possibly
215  /// access a function pointer.
216  virtual bool mayHaveFunctionPointerAccess(const Relocation& pReloc) const;
217
218private:
219  void scanLocalReloc(Relocation& pReloc,
220                      IRBuilder& pBuilder,
221                      Module& pModule,
222                      LDSection& pSection);
223
224  void scanGlobalReloc(Relocation& pReloc,
225                       IRBuilder& pBuilder,
226                       Module& pModule,
227                       LDSection& pSection);
228
229private:
230  X86_64GNULDBackend& m_Target;
231  SymGOTMap m_SymGOTMap;
232  SymGOTPLTMap m_SymGOTPLTMap;
233  RelRelMap m_RelRelMap;
234};
235
236} // namespace of mcld
237
238#endif
239
240