1 //===-- llvm/MC/MCELFObjectWriter.h - ELF Object Writer ---------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_MC_MCELFOBJECTWRITER_H 11 #define LLVM_MC_MCELFOBJECTWRITER_H 12 13 #include "llvm/ADT/Triple.h" 14 #include "llvm/Support/DataTypes.h" 15 #include "llvm/Support/ELF.h" 16 #include <vector> 17 18 namespace llvm { 19 class MCAssembler; 20 class MCFixup; 21 class MCFragment; 22 class MCObjectWriter; 23 class MCSectionData; 24 class MCSymbol; 25 class MCSymbolData; 26 class MCValue; 27 28 class MCELFObjectTargetWriter { 29 const uint8_t OSABI; 30 const uint16_t EMachine; 31 const unsigned HasRelocationAddend : 1; 32 const unsigned Is64Bit : 1; 33 const unsigned IsN64 : 1; 34 35 protected: 36 37 MCELFObjectTargetWriter(bool Is64Bit_, uint8_t OSABI_, 38 uint16_t EMachine_, bool HasRelocationAddend, 39 bool IsN64=false); 40 41 public: getOSABI(Triple::OSType OSType)42 static uint8_t getOSABI(Triple::OSType OSType) { 43 switch (OSType) { 44 case Triple::FreeBSD: 45 return ELF::ELFOSABI_FREEBSD; 46 case Triple::Linux: 47 return ELF::ELFOSABI_LINUX; 48 default: 49 return ELF::ELFOSABI_NONE; 50 } 51 } 52 ~MCELFObjectTargetWriter()53 virtual ~MCELFObjectTargetWriter() {} 54 55 virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, 56 bool IsPCRel) const = 0; 57 58 virtual bool needsRelocateWithSymbol(const MCSymbolData &SD, 59 unsigned Type) const; 60 61 /// @name Accessors 62 /// @{ getOSABI()63 uint8_t getOSABI() const { return OSABI; } getEMachine()64 uint16_t getEMachine() const { return EMachine; } hasRelocationAddend()65 bool hasRelocationAddend() const { return HasRelocationAddend; } is64Bit()66 bool is64Bit() const { return Is64Bit; } isN64()67 bool isN64() const { return IsN64; } 68 /// @} 69 70 // Instead of changing everyone's API we pack the N64 Type fields 71 // into the existing 32 bit data unsigned. 72 #define R_TYPE_SHIFT 0 73 #define R_TYPE_MASK 0xffffff00 74 #define R_TYPE2_SHIFT 8 75 #define R_TYPE2_MASK 0xffff00ff 76 #define R_TYPE3_SHIFT 16 77 #define R_TYPE3_MASK 0xff00ffff 78 #define R_SSYM_SHIFT 24 79 #define R_SSYM_MASK 0x00ffffff 80 81 // N64 relocation type accessors getRType(uint32_t Type)82 uint8_t getRType(uint32_t Type) const { 83 return (unsigned)((Type >> R_TYPE_SHIFT) & 0xff); 84 } getRType2(uint32_t Type)85 uint8_t getRType2(uint32_t Type) const { 86 return (unsigned)((Type >> R_TYPE2_SHIFT) & 0xff); 87 } getRType3(uint32_t Type)88 uint8_t getRType3(uint32_t Type) const { 89 return (unsigned)((Type >> R_TYPE3_SHIFT) & 0xff); 90 } getRSsym(uint32_t Type)91 uint8_t getRSsym(uint32_t Type) const { 92 return (unsigned)((Type >> R_SSYM_SHIFT) & 0xff); 93 } 94 95 // N64 relocation type setting setRType(unsigned Value,unsigned Type)96 unsigned setRType(unsigned Value, unsigned Type) const { 97 return ((Type & R_TYPE_MASK) | ((Value & 0xff) << R_TYPE_SHIFT)); 98 } setRType2(unsigned Value,unsigned Type)99 unsigned setRType2(unsigned Value, unsigned Type) const { 100 return (Type & R_TYPE2_MASK) | ((Value & 0xff) << R_TYPE2_SHIFT); 101 } setRType3(unsigned Value,unsigned Type)102 unsigned setRType3(unsigned Value, unsigned Type) const { 103 return (Type & R_TYPE3_MASK) | ((Value & 0xff) << R_TYPE3_SHIFT); 104 } setRSsym(unsigned Value,unsigned Type)105 unsigned setRSsym(unsigned Value, unsigned Type) const { 106 return (Type & R_SSYM_MASK) | ((Value & 0xff) << R_SSYM_SHIFT); 107 } 108 }; 109 110 /// \brief Construct a new ELF writer instance. 111 /// 112 /// \param MOTW - The target specific ELF writer subclass. 113 /// \param OS - The stream to write to. 114 /// \returns The constructed object writer. 115 MCObjectWriter *createELFObjectWriter(MCELFObjectTargetWriter *MOTW, 116 raw_ostream &OS, bool IsLittleEndian); 117 } // End llvm namespace 118 119 #endif 120