text: //===-- ARMWinCOFFObjectWriter.cpp - ARM Windows COFF Object Writer -- C++ -==//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "MCTargetDesc/ARMFixupKinds.h"
  #include "llvm/ADT/Twine.h"
  #include "llvm/BinaryFormat/COFF.h"
  #include "llvm/MC/MCAsmBackend.h"
  #include "llvm/MC/MCExpr.h"
  #include "llvm/MC/MCFixup.h"
  #include "llvm/MC/MCFixupKindInfo.h"
  #include "llvm/MC/MCObjectWriter.h"
  #include "llvm/MC/MCValue.h"
  #include "llvm/MC/MCWinCOFFObjectWriter.h"
  #include "llvm/Support/ErrorHandling.h"
  #include "llvm/Support/raw_ostream.h"
  #include <cassert>
  
  using namespace llvm;
  
  namespace {
  
  class ARMWinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter {
  public:
    ARMWinCOFFObjectWriter(bool Is64Bit)
      : MCWinCOFFObjectTargetWriter(COFF::IMAGE_FILE_MACHINE_ARMNT) {
      assert(!Is64Bit && "AArch64 support not yet implemented");
    }
  
    ~ARMWinCOFFObjectWriter() override = default;
  
    unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
                          const MCFixup &Fixup, bool IsCrossSection,
                          const MCAsmBackend &MAB) const override;
  
    bool recordRelocation(const MCFixup &) const override;
  };
  
  } // end anonymous namespace
  
  unsigned ARMWinCOFFObjectWriter::getRelocType(MCContext &Ctx,
                                                const MCValue &Target,
                                                const MCFixup &Fixup,
                                                bool IsCrossSection,
                                                const MCAsmBackend &MAB) const {
    assert(getMachine() == COFF::IMAGE_FILE_MACHINE_ARMNT &&
           "AArch64 support not yet implemented");
  
    MCSymbolRefExpr::VariantKind Modifier =
      Target.isAbsolute() ? MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
  
    switch (static_cast<unsigned>(Fixup.getKind())) {
    default: {
      const MCFixupKindInfo &Info = MAB.getFixupKindInfo(Fixup.getKind());
      report_fatal_error(Twine("unsupported relocation type: ") + Info.Name);
    }
    case FK_Data_4:
      switch (Modifier) {
      case MCSymbolRefExpr::VK_COFF_IMGREL32:
        return COFF::IMAGE_REL_ARM_ADDR32NB;
      case MCSymbolRefExpr::VK_SECREL:
        return COFF::IMAGE_REL_ARM_SECREL;
      default:
        return COFF::IMAGE_REL_ARM_ADDR32;
      }
    case FK_SecRel_2:
      return COFF::IMAGE_REL_ARM_SECTION;
    case FK_SecRel_4:
      return COFF::IMAGE_REL_ARM_SECREL;
    case ARM::fixup_t2_condbranch:
      return COFF::IMAGE_REL_ARM_BRANCH20T;
    case ARM::fixup_t2_uncondbranch:
      return COFF::IMAGE_REL_ARM_BRANCH24T;
    case ARM::fixup_arm_thumb_bl:
    case ARM::fixup_arm_thumb_blx:
      return COFF::IMAGE_REL_ARM_BLX23T;
    case ARM::fixup_t2_movw_lo16:
    case ARM::fixup_t2_movt_hi16:
      return COFF::IMAGE_REL_ARM_MOV32T;
    }
  }
  
  bool ARMWinCOFFObjectWriter::recordRelocation(const MCFixup &Fixup) const {
    return static_cast<unsigned>(Fixup.getKind()) != ARM::fixup_t2_movt_hi16;
  }
  
  namespace llvm {
  
  std::unique_ptr<MCObjectWriter>
  createARMWinCOFFObjectWriter(raw_pwrite_stream &OS, bool Is64Bit) {
    auto MOTW = llvm::make_unique<ARMWinCOFFObjectWriter>(Is64Bit);
    return createWinCOFFObjectWriter(std::move(MOTW), OS);
  }
  
  } // end namespace llvm
  