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 18namespace llvm { 19class MCAssembler; 20class MCFixup; 21class MCFragment; 22class MCObjectWriter; 23class MCSymbol; 24class MCSymbolELF; 25class MCValue; 26class raw_pwrite_stream; 27 28struct ELFRelocationEntry { 29 uint64_t Offset; // Where is the relocation. 30 const MCSymbolELF *Symbol; // The symbol to relocate with. 31 unsigned Type; // The type of the relocation. 32 uint64_t Addend; // The addend to use. 33 34 ELFRelocationEntry(uint64_t Offset, const MCSymbolELF *Symbol, unsigned Type, 35 uint64_t Addend) 36 : Offset(Offset), Symbol(Symbol), Type(Type), Addend(Addend) {} 37}; 38 39class MCELFObjectTargetWriter { 40 const uint8_t OSABI; 41 const uint16_t EMachine; 42 const unsigned HasRelocationAddend : 1; 43 const unsigned Is64Bit : 1; 44 const unsigned IsN64 : 1; 45 46protected: 47 48 MCELFObjectTargetWriter(bool Is64Bit_, uint8_t OSABI_, 49 uint16_t EMachine_, bool HasRelocationAddend, 50 bool IsN64=false); 51 52public: 53 static uint8_t getOSABI(Triple::OSType OSType) { 54 switch (OSType) { 55 case Triple::CloudABI: 56 return ELF::ELFOSABI_CLOUDABI; 57 case Triple::PS4: 58 case Triple::FreeBSD: 59 return ELF::ELFOSABI_FREEBSD; 60 default: 61 return ELF::ELFOSABI_NONE; 62 } 63 } 64 65 virtual ~MCELFObjectTargetWriter() {} 66 67 virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, 68 bool IsPCRel) const = 0; 69 70 virtual bool needsRelocateWithSymbol(const MCSymbol &Sym, 71 unsigned Type) const; 72 73 virtual void sortRelocs(const MCAssembler &Asm, 74 std::vector<ELFRelocationEntry> &Relocs); 75 76 /// \name Accessors 77 /// @{ 78 uint8_t getOSABI() const { return OSABI; } 79 uint16_t getEMachine() const { return EMachine; } 80 bool hasRelocationAddend() const { return HasRelocationAddend; } 81 bool is64Bit() const { return Is64Bit; } 82 bool isN64() const { return IsN64; } 83 /// @} 84 85 // Instead of changing everyone's API we pack the N64 Type fields 86 // into the existing 32 bit data unsigned. 87#define R_TYPE_SHIFT 0 88#define R_TYPE_MASK 0xffffff00 89#define R_TYPE2_SHIFT 8 90#define R_TYPE2_MASK 0xffff00ff 91#define R_TYPE3_SHIFT 16 92#define R_TYPE3_MASK 0xff00ffff 93#define R_SSYM_SHIFT 24 94#define R_SSYM_MASK 0x00ffffff 95 96 // N64 relocation type accessors 97 uint8_t getRType(uint32_t Type) const { 98 return (unsigned)((Type >> R_TYPE_SHIFT) & 0xff); 99 } 100 uint8_t getRType2(uint32_t Type) const { 101 return (unsigned)((Type >> R_TYPE2_SHIFT) & 0xff); 102 } 103 uint8_t getRType3(uint32_t Type) const { 104 return (unsigned)((Type >> R_TYPE3_SHIFT) & 0xff); 105 } 106 uint8_t getRSsym(uint32_t Type) const { 107 return (unsigned)((Type >> R_SSYM_SHIFT) & 0xff); 108 } 109 110 // N64 relocation type setting 111 unsigned setRType(unsigned Value, unsigned Type) const { 112 return ((Type & R_TYPE_MASK) | ((Value & 0xff) << R_TYPE_SHIFT)); 113 } 114 unsigned setRType2(unsigned Value, unsigned Type) const { 115 return (Type & R_TYPE2_MASK) | ((Value & 0xff) << R_TYPE2_SHIFT); 116 } 117 unsigned setRType3(unsigned Value, unsigned Type) const { 118 return (Type & R_TYPE3_MASK) | ((Value & 0xff) << R_TYPE3_SHIFT); 119 } 120 unsigned setRSsym(unsigned Value, unsigned Type) const { 121 return (Type & R_SSYM_MASK) | ((Value & 0xff) << R_SSYM_SHIFT); 122 } 123}; 124 125/// \brief Construct a new ELF writer instance. 126/// 127/// \param MOTW - The target specific ELF writer subclass. 128/// \param OS - The stream to write to. 129/// \returns The constructed object writer. 130MCObjectWriter *createELFObjectWriter(MCELFObjectTargetWriter *MOTW, 131 raw_pwrite_stream &OS, 132 bool IsLittleEndian); 133} // End llvm namespace 134 135#endif 136