TargetLDBackend.h revision f7ac0f19a1c8d0ad14bcf6456ce368b830fea886 
1//===-- llvm/Target/TargetLDBackend.h - Target LD Backend -----*- C++ -*-===//
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 MCLD_TARGET_TARGETLDBACKEND_H
10#define MCLD_TARGET_TARGETLDBACKEND_H
11
12#include <llvm/Support/DataTypes.h>
13
14namespace mcld {
15
16class Module;
17class LinkerConfig;
18class IRBuilder;
19class Relocation;
20class RelocationFactory;
21class Relocator;
22class Layout;
23class ArchiveReader;
24class ObjectReader;
25class DynObjReader;
26class BinaryReader;
27class ObjectWriter;
28class DynObjWriter;
29class ExecWriter;
30class BinaryWriter;
31class LDFileFormat;
32class LDSymbol;
33class LDSection;
34class SectionData;
35class Input;
36class GOT;
37class MemoryArea;
38class MemoryAreaFactory;
39class BranchIslandFactory;
40class StubFactory;
41class ObjectBuilder;
42
43//===----------------------------------------------------------------------===//
44/// TargetLDBackend - Generic interface to target specific assembler backends.
45//===----------------------------------------------------------------------===//
46class TargetLDBackend
47{
48  TargetLDBackend(const TargetLDBackend &);   // DO NOT IMPLEMENT
49  void operator=(const TargetLDBackend &);  // DO NOT IMPLEMENT
50
51protected:
52  TargetLDBackend(const LinkerConfig& pConfig);
53
54public:
55  virtual ~TargetLDBackend();
56
57  // -----  target dependent  ----- //
58  virtual void initTargetSegments(IRBuilder& pBuilder) { }
59  virtual void initTargetSections(Module& pModule, ObjectBuilder& pBuilder) { }
60  virtual void initTargetSymbols(IRBuilder& pBuilder, Module& pModule) { }
61  virtual void initTargetRelocation(IRBuilder& pBuilder) { }
62  virtual bool initStandardSymbols(IRBuilder& pBuilder, Module& pModule) = 0;
63
64  virtual bool initRelocator() = 0;
65
66  virtual Relocator* getRelocator() = 0;
67
68  // -----  format dependent  ----- //
69  virtual ArchiveReader* createArchiveReader(Module&) = 0;
70  virtual ObjectReader*  createObjectReader(IRBuilder&) = 0;
71  virtual DynObjReader*  createDynObjReader(IRBuilder&) = 0;
72  virtual BinaryReader*  createBinaryReader(IRBuilder&) = 0;
73  virtual ObjectWriter*  createWriter() = 0;
74
75  virtual bool initStdSections(ObjectBuilder& pBuilder) = 0;
76
77  /// layout - layout method
78  virtual void layout(Module& pModule) = 0;
79
80  /// preLayout - Backend can do any needed modification before layout
81  virtual void preLayout(Module& pModule, IRBuilder& pBuilder) = 0;
82
83  /// postLayout - Backend can do any needed modification after layout
84  virtual void postLayout(Module& pModule, IRBuilder& pBuilder) = 0;
85
86  /// postProcessing - Backend can do any needed modification in the final stage
87  virtual void postProcessing(MemoryArea& pOutput) = 0;
88
89  /// section start offset in the output file
90  virtual size_t sectionStartOffset() const = 0;
91
92  /// computeSectionOrder - compute the layout order of the given section
93  virtual unsigned int getSectionOrder(const LDSection& pSectHdr) const = 0;
94
95  /// sizeNamePools - compute the size of regular name pools
96  /// In ELF executable files, regular name pools are .symtab, .strtab.,
97  /// .dynsym, .dynstr, and .hash
98  virtual void sizeNamePools(Module& pModule) = 0;
99
100  /// finalizeSymbol - Linker checks pSymbol.reserved() if it's not zero,
101  /// then it will ask backend to finalize the symbol value.
102  /// @return ture - if backend set the symbol value sucessfully
103  /// @return false - if backend do not recognize the symbol
104  virtual bool finalizeSymbols() = 0;
105
106  /// finalizeTLSSymbol - Linker asks backend to set the symbol value when it
107  /// meets a TLS symbol
108  virtual bool finalizeTLSSymbol(LDSymbol& pSymbol) = 0;
109
110  /// allocateCommonSymbols - allocate common symbols in the corresponding
111  /// sections.
112  virtual bool allocateCommonSymbols(Module& pModule) = 0;
113
114  /// mergeSection - merge target dependent sections.
115  virtual bool mergeSection(Module& pModule, LDSection& pInputSection)
116  { return true; }
117
118  /// updateSectionFlags - update pTo's flags when merging pFrom
119  /// update the output section flags based on input section flags.
120  /// FIXME: (Luba) I know ELF need to merge flags, but I'm not sure if
121  /// MachO and COFF also need this.
122  virtual bool updateSectionFlags(LDSection& pTo, const LDSection& pFrom)
123  { return true; }
124
125  /// readSection - read a target dependent section
126  virtual bool readSection(Input& pInput, SectionData& pSD)
127  { return true; }
128
129  /// sizeInterp - compute the size of program interpreter's name
130  /// In ELF executables, this is the length of dynamic linker's path name
131  virtual void sizeInterp() = 0;
132
133  // -----  relaxation  ----- //
134  virtual bool initBRIslandFactory() = 0;
135  virtual bool initStubFactory() = 0;
136  virtual bool initTargetStubs() { return true; }
137
138  virtual BranchIslandFactory* getBRIslandFactory() = 0;
139  virtual StubFactory*         getStubFactory() = 0;
140
141  /// relax - the relaxation pass
142  virtual bool relax(Module& pModule, IRBuilder& pBuilder) = 0;
143
144  /// mayRelax - return true if the backend needs to do relaxation
145  virtual bool mayRelax() = 0;
146
147protected:
148  const LinkerConfig& config() const { return m_Config; }
149
150private:
151  const LinkerConfig& m_Config;
152};
153
154} // End mcld namespace
155
156#endif
157