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
15using namespace llvm;
16
17namespace {
18class BPFELFObjectWriter : public MCELFObjectTargetWriter {
19public:
20  BPFELFObjectWriter(uint8_t OSABI);
21
22  ~BPFELFObjectWriter() override;
23
24protected:
25  unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
26                        bool IsPCRel) const override;
27};
28}
29
30BPFELFObjectWriter::BPFELFObjectWriter(uint8_t OSABI)
31    : MCELFObjectTargetWriter(/*Is64Bit*/ true, OSABI, ELF::EM_NONE,
32                              /*HasRelocationAddend*/ false) {}
33
34BPFELFObjectWriter::~BPFELFObjectWriter() {}
35
36unsigned 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
54MCObjectWriter *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