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 14 namespace mcld { 15 16 class Module; 17 class LinkerConfig; 18 class IRBuilder; 19 class Relocation; 20 class RelocationFactory; 21 class Relocator; 22 class Layout; 23 class ArchiveReader; 24 class ObjectReader; 25 class DynObjReader; 26 class BinaryReader; 27 class ObjectWriter; 28 class DynObjWriter; 29 class ExecWriter; 30 class BinaryWriter; 31 class LDFileFormat; 32 class LDSymbol; 33 class LDSection; 34 class SectionData; 35 class Input; 36 class GOT; 37 class MemoryArea; 38 class MemoryAreaFactory; 39 class BranchIslandFactory; 40 class StubFactory; 41 class ObjectBuilder; 42 43 //===----------------------------------------------------------------------===// 44 /// TargetLDBackend - Generic interface to target specific assembler backends. 45 //===----------------------------------------------------------------------===// 46 class TargetLDBackend 47 { 48 TargetLDBackend(const TargetLDBackend &); // DO NOT IMPLEMENT 49 void operator=(const TargetLDBackend &); // DO NOT IMPLEMENT 50 51 protected: 52 TargetLDBackend(const LinkerConfig& pConfig); 53 54 public: 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; 146 147 protected: 148 const LinkerConfig& config() const { return m_Config; } 149 150 private: 151 const LinkerConfig& m_Config; 152 }; 153 154 } // End mcld namespace 155 156 #endif 157
