1 //===-- BPFELFObjectWriter.cpp - BPF ELF Writer ---------------------------===// 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 #include "MCTargetDesc/BPFMCTargetDesc.h" 11 #include "llvm/MC/MCELFObjectWriter.h" 12 #include "llvm/MC/MCFixup.h" 13 #include "llvm/Support/ErrorHandling.h" 14 15 using namespace llvm; 16 17 namespace { 18 class BPFELFObjectWriter : public MCELFObjectTargetWriter { 19 public: 20 BPFELFObjectWriter(uint8_t OSABI); 21 22 ~BPFELFObjectWriter() override; 23 24 protected: 25 unsigned getRelocType(MCContext &Ctx, const MCValue &Target, 26 const MCFixup &Fixup, bool IsPCRel) const override; 27 }; 28 } 29 30 BPFELFObjectWriter::BPFELFObjectWriter(uint8_t OSABI) 31 : MCELFObjectTargetWriter(/*Is64Bit*/ true, OSABI, ELF::EM_NONE, 32 /*HasRelocationAddend*/ false) {} 33 34 BPFELFObjectWriter::~BPFELFObjectWriter() {} 35 36 unsigned BPFELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target, 37 const MCFixup &Fixup, 38 bool IsPCRel) const { 39 // determine the type of the relocation 40 switch ((unsigned)Fixup.getKind()) { 41 default: 42 llvm_unreachable("invalid fixup kind!"); 43 case FK_SecRel_8: 44 return ELF::R_X86_64_64; 45 case FK_SecRel_4: 46 return ELF::R_X86_64_PC32; 47 case FK_Data_8: 48 return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64; 49 case FK_Data_4: 50 return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32; 51 } 52 } 53 54 MCObjectWriter *llvm::createBPFELFObjectWriter(raw_pwrite_stream &OS, 55 uint8_t OSABI, bool IsLittleEndian) { 56 MCELFObjectTargetWriter *MOTW = new BPFELFObjectWriter(OSABI); 57 return createELFObjectWriter(MOTW, OS, IsLittleEndian); 58 } 59
