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
BPFELFObjectWriter(uint8_t OSABI)30 BPFELFObjectWriter::BPFELFObjectWriter(uint8_t OSABI)
31 : MCELFObjectTargetWriter(/*Is64Bit*/ true, OSABI, ELF::EM_NONE,
32 /*HasRelocationAddend*/ false) {}
33
~BPFELFObjectWriter()34 BPFELFObjectWriter::~BPFELFObjectWriter() {}
35
getRelocType(MCContext & Ctx,const MCValue & Target,const MCFixup & Fixup,bool IsPCRel) const36 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
createBPFELFObjectWriter(raw_pwrite_stream & OS,uint8_t OSABI,bool IsLittleEndian)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