contrib/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp

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