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