lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp

   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
  36 X86WinCOFFObjectWriter::X86WinCOFFObjectWriter(bool Is64Bit)
  37     : MCWinCOFFObjectTargetWriter(Is64Bit ? COFF::IMAGE_FILE_MACHINE_AMD64
  38                                           : COFF::IMAGE_FILE_MACHINE_I386) {}
  39
  40 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>
 111 llvm::createX86WinCOFFObjectWriter(bool Is64Bit) {
 112   return llvm::make_unique<X86WinCOFFObjectWriter>(Is64Bit);
 113 }