contrib/llvm/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp

   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(const MCValue &Target, const MCFixup &Fixup,
  26                         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(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 }