1 //===- Relocator.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 MCLD_LD_RELOCATOR_H_ 10 #define MCLD_LD_RELOCATOR_H_ 11 12 #include "mcld/Fragment/Relocation.h" 13 14 namespace mcld { 15 16 class Input; 17 class IRBuilder; 18 class Module; 19 class TargetLDBackend; 20 21 /** \class Relocator 22 * \brief Relocator provides the interface of performing relocations 23 */ 24 class Relocator { 25 public: 26 typedef Relocation::Type Type; 27 typedef Relocation::Address Address; 28 typedef Relocation::DWord DWord; 29 typedef Relocation::SWord SWord; 30 typedef Relocation::Size Size; 31 32 public: 33 enum Result { OK, BadReloc, Overflow, Unsupported, Unknown }; 34 35 public: 36 explicit Relocator(const LinkerConfig& pConfig) : m_Config(pConfig) {} 37 38 virtual ~Relocator() = 0; 39 40 /// apply - general apply function 41 virtual Result applyRelocation(Relocation& pRelocation) = 0; 42 43 /// scanRelocation - When read in relocations, backend can do any modification 44 /// to relocation and generate empty entries, such as GOT, dynamic relocation 45 /// entries and other target dependent entries. These entries are generated 46 /// for layout to adjust the ouput offset. 47 /// @param pReloc - a read in relocation entry 48 /// @param pInputSym - the input LDSymbol of relocation target symbol 49 /// @param pSection - the section of relocation applying target 50 /// @param pInput - the input file of relocation 51 virtual void scanRelocation(Relocation& pReloc, 52 IRBuilder& pBuilder, 53 Module& pModule, 54 LDSection& pSection, 55 Input& pInput) = 0; 56 57 /// issueUndefRefError - Provides a basic version for undefined reference 58 /// dump. 59 /// It will handle the filename and function name automatically. 60 /// @param pReloc - a read in relocation entry 61 /// @param pSection - the section of relocation applying target 62 /// @ param pInput - the input file of relocation 63 virtual void issueUndefRef(Relocation& pReloc, 64 LDSection& pSection, 65 Input& pInput); 66 67 /// initializeScan - do initialization before scan relocations in pInput 68 /// @return - return true for initialization success 69 virtual bool initializeScan(Input& pInput) { return true; } 70 71 /// finalizeScan - do finalization after scan relocations in pInput 72 /// @return - return true for finalization success 73 virtual bool finalizeScan(Input& pInput) { return true; } 74 75 /// initializeApply - do initialization before apply relocations in pInput 76 /// @return - return true for initialization success 77 virtual bool initializeApply(Input& pInput) { return true; } 78 79 /// finalizeApply - do finalization after apply relocations in pInput 80 /// @return - return true for finalization success 81 virtual bool finalizeApply(Input& pInput) { return true; } 82 83 /// partialScanRelocation - When doing partial linking, backend can do any 84 /// modification to relocation to fix the relocation offset after section 85 /// merge 86 /// @param pReloc - a read in relocation entry 87 /// @param pInputSym - the input LDSymbol of relocation target symbol 88 /// @param pSection - the section of relocation applying target 89 virtual void partialScanRelocation(Relocation& pReloc, 90 Module& pModule); 91 92 // ------ observers -----// 93 virtual TargetLDBackend& getTarget() = 0; 94 95 virtual const TargetLDBackend& getTarget() const = 0; 96 97 /// getName - get the name of a relocation 98 virtual const char* getName(Type pType) const = 0; 99 100 /// getSize - get the size of a relocation in bit 101 virtual Size getSize(Type pType) const = 0; 102 103 /// mayHaveFunctionPointerAccess - check if the given reloc would possibly 104 /// access a function pointer. 105 /// Note: Each target relocator should override this function, or be 106 /// conservative and return true to avoid getting folded. 107 virtual bool mayHaveFunctionPointerAccess(const Relocation& pReloc) const { 108 return true; 109 } 110 111 /// getDebugStringOffset - get the offset from the relocation target. This is 112 /// used to get the debug string offset. 113 virtual uint32_t getDebugStringOffset(Relocation& pReloc) const = 0; 114 115 /// applyDebugStringOffset - apply the relocation target to specific offset. 116 /// This is used to set the debug string offset. 117 virtual void applyDebugStringOffset(Relocation& pReloc, uint32_t pOffset) = 0; 118 119 protected: 120 const LinkerConfig& config() const { return m_Config; } 121 122 private: 123 const LinkerConfig& m_Config; 124 }; 125 126 } // namespace mcld 127 128 #endif // MCLD_LD_RELOCATOR_H_ 129
