1 //===-- X86WinCOFFObjectWriter.cpp - X86 Win COFF 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/X86FixupKinds.h"
11 #include "MCTargetDesc/X86MCTargetDesc.h"
12 #include "llvm/MC/MCExpr.h"
13 #include "llvm/MC/MCValue.h"
14 #include "llvm/MC/MCWinCOFFObjectWriter.h"
15 #include "llvm/Support/COFF.h"
16 #include "llvm/Support/ErrorHandling.h"
17 
18 using namespace llvm;
19 
20 namespace llvm {
21   class MCObjectWriter;
22 }
23 
24 namespace {
25   class X86WinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter {
26   public:
27     X86WinCOFFObjectWriter(bool Is64Bit);
28     ~X86WinCOFFObjectWriter() override;
29 
30     unsigned getRelocType(const MCValue &Target, const MCFixup &Fixup,
31                           bool IsCrossSection,
32                           const MCAsmBackend &MAB) const override;
33   };
34 }
35 
X86WinCOFFObjectWriter(bool Is64Bit)36 X86WinCOFFObjectWriter::X86WinCOFFObjectWriter(bool Is64Bit)
37     : MCWinCOFFObjectTargetWriter(Is64Bit ? COFF::IMAGE_FILE_MACHINE_AMD64
38                                           : COFF::IMAGE_FILE_MACHINE_I386) {}
39 
~X86WinCOFFObjectWriter()40 X86WinCOFFObjectWriter::~X86WinCOFFObjectWriter() {}
41 
getRelocType(const MCValue & Target,const MCFixup & Fixup,bool IsCrossSection,const MCAsmBackend & MAB) const42 unsigned X86WinCOFFObjectWriter::getRelocType(const MCValue &Target,
43                                               const MCFixup &Fixup,
44                                               bool IsCrossSection,
45                                               const MCAsmBackend &MAB) const {
46   unsigned FixupKind = IsCrossSection ? FK_PCRel_4 : Fixup.getKind();
47 
48   MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
49     MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
50 
51   if (getMachine() == COFF::IMAGE_FILE_MACHINE_AMD64) {
52     switch (FixupKind) {
53     case FK_PCRel_4:
54     case X86::reloc_riprel_4byte:
55     case X86::reloc_riprel_4byte_movq_load:
56       return COFF::IMAGE_REL_AMD64_REL32;
57     case FK_Data_4:
58     case X86::reloc_signed_4byte:
59       if (Modifier == MCSymbolRefExpr::VK_COFF_IMGREL32)
60         return COFF::IMAGE_REL_AMD64_ADDR32NB;
61       return COFF::IMAGE_REL_AMD64_ADDR32;
62     case FK_Data_8:
63       return COFF::IMAGE_REL_AMD64_ADDR64;
64     case FK_SecRel_2:
65       return COFF::IMAGE_REL_AMD64_SECTION;
66     case FK_SecRel_4:
67       return COFF::IMAGE_REL_AMD64_SECREL;
68     default:
69       llvm_unreachable("unsupported relocation type");
70     }
71   } else if (getMachine() == COFF::IMAGE_FILE_MACHINE_I386) {
72     switch (FixupKind) {
73     case FK_PCRel_4:
74     case X86::reloc_riprel_4byte:
75     case X86::reloc_riprel_4byte_movq_load:
76       return COFF::IMAGE_REL_I386_REL32;
77     case FK_Data_4:
78     case X86::reloc_signed_4byte:
79       if (Modifier == MCSymbolRefExpr::VK_COFF_IMGREL32)
80         return COFF::IMAGE_REL_I386_DIR32NB;
81       return COFF::IMAGE_REL_I386_DIR32;
82     case FK_SecRel_2:
83       return COFF::IMAGE_REL_I386_SECTION;
84     case FK_SecRel_4:
85       return COFF::IMAGE_REL_I386_SECREL;
86     default:
87       llvm_unreachable("unsupported relocation type");
88     }
89   } else
90     llvm_unreachable("Unsupported COFF machine type.");
91 }
92 
createX86WinCOFFObjectWriter(raw_pwrite_stream & OS,bool Is64Bit)93 MCObjectWriter *llvm::createX86WinCOFFObjectWriter(raw_pwrite_stream &OS,
94                                                    bool Is64Bit) {
95   MCWinCOFFObjectTargetWriter *MOTW = new X86WinCOFFObjectWriter(Is64Bit);
96   return createWinCOFFObjectWriter(MOTW, OS);
97 }
98