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
20 using namespace llvm;
21
22 namespace {
23
24 class X86WinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter {
25 public:
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
X86WinCOFFObjectWriter(bool Is64Bit)36 X86WinCOFFObjectWriter::X86WinCOFFObjectWriter(bool Is64Bit)
37 : MCWinCOFFObjectTargetWriter(Is64Bit ? COFF::IMAGE_FILE_MACHINE_AMD64
38 : COFF::IMAGE_FILE_MACHINE_I386) {}
39
getRelocType(MCContext & Ctx,const MCValue & Target,const MCFixup & Fixup,bool IsCrossSection,const MCAsmBackend & MAB) const40 unsigned 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
110 std::unique_ptr<MCObjectTargetWriter>
createX86WinCOFFObjectWriter(bool Is64Bit)111 llvm::createX86WinCOFFObjectWriter(bool Is64Bit) {
112 return std::make_unique<X86WinCOFFObjectWriter>(Is64Bit);
113 }
114