1//===-- X86WinCOFFObjectWriter.cpp - X86 Win COFF Writer ------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "MCTargetDesc/X86FixupKinds.h"
10#include "MCTargetDesc/X86MCTargetDesc.h"
11#include "llvm/BinaryFormat/COFF.h"
12#include "llvm/MC/MCContext.h"
13#include "llvm/MC/MCExpr.h"
14#include "llvm/MC/MCFixup.h"
15#include "llvm/MC/MCObjectWriter.h"
16#include "llvm/MC/MCValue.h"
17#include "llvm/MC/MCWinCOFFObjectWriter.h"
18#include "llvm/Support/ErrorHandling.h"
19
20using namespace llvm;
21
22namespace {
23
24class X86WinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter {
25public:
26  X86WinCOFFObjectWriter(bool Is64Bit);
27  ~X86WinCOFFObjectWriter() override = default;
28
29  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
30                        const MCFixup &Fixup, bool IsCrossSection,
31                        const MCAsmBackend &MAB) const override;
32};
33
34} // end anonymous namespace
35
36X86WinCOFFObjectWriter::X86WinCOFFObjectWriter(bool Is64Bit)
37    : MCWinCOFFObjectTargetWriter(Is64Bit ? COFF::IMAGE_FILE_MACHINE_AMD64
38                                          : COFF::IMAGE_FILE_MACHINE_I386) {}
39
40unsigned X86WinCOFFObjectWriter::getRelocType(MCContext &Ctx,
41                                              const MCValue &Target,
42                                              const MCFixup &Fixup,
43                                              bool IsCrossSection,
44                                              const MCAsmBackend &MAB) const {
45  unsigned FixupKind = Fixup.getKind();
46  if (IsCrossSection) {
47    if (FixupKind != FK_Data_4 && FixupKind != llvm::X86::reloc_signed_4byte) {
48      Ctx.reportError(Fixup.getLoc(), "Cannot represent this expression");
49      return COFF::IMAGE_REL_AMD64_ADDR32;
50    }
51    FixupKind = FK_PCRel_4;
52  }
53
54  MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
55    MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
56
57  if (getMachine() == COFF::IMAGE_FILE_MACHINE_AMD64) {
58    switch (FixupKind) {
59    case FK_PCRel_4:
60    case X86::reloc_riprel_4byte:
61    case X86::reloc_riprel_4byte_movq_load:
62    case X86::reloc_riprel_4byte_relax:
63    case X86::reloc_riprel_4byte_relax_rex:
64    case X86::reloc_branch_4byte_pcrel:
65      return COFF::IMAGE_REL_AMD64_REL32;
66    case FK_Data_4:
67    case X86::reloc_signed_4byte:
68    case X86::reloc_signed_4byte_relax:
69      if (Modifier == MCSymbolRefExpr::VK_COFF_IMGREL32)
70        return COFF::IMAGE_REL_AMD64_ADDR32NB;
71      if (Modifier == MCSymbolRefExpr::VK_SECREL)
72        return COFF::IMAGE_REL_AMD64_SECREL;
73      return COFF::IMAGE_REL_AMD64_ADDR32;
74    case FK_Data_8:
75      return COFF::IMAGE_REL_AMD64_ADDR64;
76    case FK_SecRel_2:
77      return COFF::IMAGE_REL_AMD64_SECTION;
78    case FK_SecRel_4:
79      return COFF::IMAGE_REL_AMD64_SECREL;
80    default:
81      Ctx.reportError(Fixup.getLoc(), "unsupported relocation type");
82      return COFF::IMAGE_REL_AMD64_ADDR32;
83    }
84  } else if (getMachine() == COFF::IMAGE_FILE_MACHINE_I386) {
85    switch (FixupKind) {
86    case FK_PCRel_4:
87    case X86::reloc_riprel_4byte:
88    case X86::reloc_riprel_4byte_movq_load:
89      return COFF::IMAGE_REL_I386_REL32;
90    case FK_Data_4:
91    case X86::reloc_signed_4byte:
92    case X86::reloc_signed_4byte_relax:
93      if (Modifier == MCSymbolRefExpr::VK_COFF_IMGREL32)
94        return COFF::IMAGE_REL_I386_DIR32NB;
95      if (Modifier == MCSymbolRefExpr::VK_SECREL)
96        return COFF::IMAGE_REL_AMD64_SECREL;
97      return COFF::IMAGE_REL_I386_DIR32;
98    case FK_SecRel_2:
99      return COFF::IMAGE_REL_I386_SECTION;
100    case FK_SecRel_4:
101      return COFF::IMAGE_REL_I386_SECREL;
102    default:
103      Ctx.reportError(Fixup.getLoc(), "unsupported relocation type");
104      return COFF::IMAGE_REL_I386_DIR32;
105    }
106  } else
107    llvm_unreachable("Unsupported COFF machine type.");
108}
109
110std::unique_ptr<MCObjectTargetWriter>
111llvm::createX86WinCOFFObjectWriter(bool Is64Bit) {
112  return std::make_unique<X86WinCOFFObjectWriter>(Is64Bit);
113}
114