AArch64LDBackend.h revision 551ae4ebd3e9d137ea668fb83ae4a55b8cfba451 
1//===- AArch64LDBackend.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_AARCH64LDBACKEND_H
10#define TARGET_AARCH64_AARCH64LDBACKEND_H
11
12#include "AArch64ELFDynamic.h"
13#include "AArch64GOT.h"
14#include "AArch64PLT.h"
15#include <mcld/LD/LDSection.h>
16#include <mcld/Target/GNULDBackend.h>
17#include <mcld/Target/OutputRelocSection.h>
18
19namespace mcld {
20
21class LinkerConfig;
22class GNUInfo;
23
24//===----------------------------------------------------------------------===//
25/// AArch64GNULDBackend - linker backend of AArch64 target of GNU ELF format
26///
27class AArch64GNULDBackend : public GNULDBackend
28{
29public:
30  AArch64GNULDBackend(const LinkerConfig& pConfig, GNUInfo* pInfo);
31  ~AArch64GNULDBackend();
32
33public:
34  /// initTargetSections - initialize target dependent sections in output.
35  void initTargetSections(Module& pModule, ObjectBuilder& pBuilder);
36
37  /// initTargetSymbols - initialize target dependent symbols in output.
38  void initTargetSymbols(IRBuilder& pBuilder, Module& pModule);
39
40  /// initRelocator - create and initialize Relocator.
41  bool initRelocator();
42
43  /// getRelocator - return relocator.
44  Relocator* getRelocator();
45
46
47  /// doPreLayout - Backend can do any needed modification before layout
48  void doPreLayout(IRBuilder& pBuilder);
49
50  /// doPostLayout -Backend can do any needed modification after layout
51  void doPostLayout(Module& pModule, IRBuilder& pBuilder);
52
53  /// dynamic - the dynamic section of the target machine.
54  /// Use co-variant return type to return its own dynamic section.
55  AArch64ELFDynamic& dynamic();
56
57  /// dynamic - the dynamic section of the target machine.
58  /// Use co-variant return type to return its own dynamic section.
59  const AArch64ELFDynamic& dynamic() const;
60
61
62  /// emitSectionData - write out the section data into the memory region.
63  /// When writers get a LDSection whose kind is LDFileFormat::Target, writers
64  /// call back target backend to emit the data.
65  ///
66  /// Backends handle the target-special tables (plt, gp,...) by themselves.
67  /// Backend can put the data of the tables in SectionData directly
68  ///  - LDSection.getSectionData can get the section data.
69  /// Or, backend can put the data into special data structure
70  ///  - backend can maintain its own map<LDSection, table> to get the table
71  /// from given LDSection.
72  ///
73  /// @param pSection - the given LDSection
74  /// @param pConfig - all options in the command line.
75  /// @param pRegion - the region to write out data
76  /// @return the size of the table in the file.
77  uint64_t emitSectionData(const LDSection& pSection,
78                           MemoryRegion& pRegion) const;
79
80  AArch64GOT& getGOT();
81  const AArch64GOT& getGOT() const;
82
83  AArch64GOT& getGOTPLT();
84  const AArch64GOT& getGOTPLT() const;
85
86  AArch64PLT& getPLT();
87  const AArch64PLT& getPLT() const;
88
89  OutputRelocSection& getRelaDyn();
90  const OutputRelocSection& getRelaDyn() const;
91
92  OutputRelocSection& getRelaPLT();
93  const OutputRelocSection& getRelaPLT() const;
94
95  LDSymbol* getGOTSymbol()             { return m_pGOTSymbol; }
96  const LDSymbol* getGOTSymbol() const { return m_pGOTSymbol; }
97
98  /// getTargetSectionOrder - compute the layout order of AArch64 target sections
99  unsigned int getTargetSectionOrder(const LDSection& pSectHdr) const;
100
101  /// finalizeTargetSymbols - finalize the symbol value
102  bool finalizeTargetSymbols();
103
104  /// mergeSection - merge target dependent sections
105  bool mergeSection(Module& pModule, const Input& pInput, LDSection& pSection);
106
107  /// readSection - read target dependent sections
108  bool readSection(Input& pInput, SectionData& pSD);
109
110private:
111  void defineGOTSymbol(IRBuilder& pBuilder);
112
113  /// maxBranchOffset
114  /// FIXME:
115  uint64_t maxBranchOffset() { return 0x0; }
116
117  /// mayRelax - Backends should override this function if they need relaxation
118  bool mayRelax() { return true; }
119
120  /// doRelax - Backend can orevride this function to add its relaxation
121  /// implementation. Return true if the output (e.g., .text) is "relaxed"
122  /// (i.e. layout is changed), and set pFinished to true if everything is fit,
123  /// otherwise set it to false.
124  bool doRelax(Module& pModule, IRBuilder& pBuilder, bool& pFinished);
125
126  /// initTargetStubs
127  bool initTargetStubs();
128
129  /// getRelEntrySize - the size in BYTE of rel type relocation
130  size_t getRelEntrySize()
131  { return 16; }
132
133  /// getRelEntrySize - the size in BYTE of rela type relocation
134  size_t getRelaEntrySize()
135  { return 24; }
136
137  /// doCreateProgramHdrs - backend can implement this function to create the
138  /// target-dependent segments
139  virtual void doCreateProgramHdrs(Module& pModule);
140
141private:
142  Relocator* m_pRelocator;
143
144  AArch64GOT* m_pGOT;
145  AArch64GOT* m_pGOTPLT;
146  AArch64PLT* m_pPLT;
147  /// m_RelDyn - dynamic relocation table of .rel.dyn
148  OutputRelocSection* m_pRelaDyn;
149  /// m_RelPLT - dynamic relocation table of .rel.plt
150  OutputRelocSection* m_pRelaPLT;
151
152  /// m_pAttrData - attribute data in public ("aeabi") attribute subsection
153  // AArch64ELFAttributeData* m_pAttrData;
154
155  AArch64ELFDynamic* m_pDynamic;
156  LDSymbol* m_pGOTSymbol;
157
158  //     variable name           :  ELF
159  LDSection* m_pAttributes;      // .ARM.attributes
160//  LDSection* m_pPreemptMap;      // .AArch64.preemptmap
161//  LDSection* m_pDebugOverlay;    // .AArch64.debug_overlay
162//  LDSection* m_pOverlayTable;    // .AArch64.overlay_table
163};
164} // namespace of mcld
165
166#endif
167
168