text: //===-- MObjectFileInfo.cpp - Object File Information ---------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm/MC/MCObjectFileInfo.h"
  #include "llvm/ADT/StringExtras.h"
  #include "llvm/ADT/Triple.h"
  #include "llvm/MC/MCAsmInfo.h"
  #include "llvm/MC/MCContext.h"
  #include "llvm/MC/MCSection.h"
  #include "llvm/MC/MCSectionCOFF.h"
  #include "llvm/MC/MCSectionELF.h"
  #include "llvm/MC/MCSectionMachO.h"
  using namespace llvm;
  
  static bool useCompactUnwind(const Triple &T) {
    // Only on darwin.
    if (!T.isOSDarwin())
      return false;
  
    // aarch64 always has it.
    if (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64)
      return true;
  
    // Use it on newer version of OS X.
    if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
      return true;
  
    // And the iOS simulator.
    if (T.isiOS() &&
        (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
      return true;
  
    return false;
  }
  
  void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
    // MachO
    SupportsWeakOmittedEHFrame = false;
  
    if (T.isOSDarwin() &&
        (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64))
      SupportsCompactUnwindWithoutEHFrame = true;
  
    PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
      | dwarf::DW_EH_PE_sdata4;
    LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
    TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
      dwarf::DW_EH_PE_sdata4;
  
    // .comm doesn't support alignment before Leopard.
    if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
      CommDirectiveSupportsAlignment = false;
  
    TextSection // .text
      = Ctx->getMachOSection("__TEXT", "__text",
                             MachO::S_ATTR_PURE_INSTRUCTIONS,
                             SectionKind::getText());
    DataSection // .data
      = Ctx->getMachOSection("__DATA", "__data", 0,
                             SectionKind::getDataRel());
  
    // BSSSection might not be expected initialized on msvc.
    BSSSection = nullptr;
  
    TLSDataSection // .tdata
      = Ctx->getMachOSection("__DATA", "__thread_data",
                             MachO::S_THREAD_LOCAL_REGULAR,
                             SectionKind::getDataRel());
    TLSBSSSection // .tbss
      = Ctx->getMachOSection("__DATA", "__thread_bss",
                             MachO::S_THREAD_LOCAL_ZEROFILL,
                             SectionKind::getThreadBSS());
  
    // TODO: Verify datarel below.
    TLSTLVSection // .tlv
      = Ctx->getMachOSection("__DATA", "__thread_vars",
                             MachO::S_THREAD_LOCAL_VARIABLES,
                             SectionKind::getDataRel());
  
    TLSThreadInitSection
      = Ctx->getMachOSection("__DATA", "__thread_init",
                            MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
                            SectionKind::getDataRel());
  
    CStringSection // .cstring
      = Ctx->getMachOSection("__TEXT", "__cstring",
                             MachO::S_CSTRING_LITERALS,
                             SectionKind::getMergeable1ByteCString());
    UStringSection
      = Ctx->getMachOSection("__TEXT","__ustring", 0,
                             SectionKind::getMergeable2ByteCString());
    FourByteConstantSection // .literal4
      = Ctx->getMachOSection("__TEXT", "__literal4",
                             MachO::S_4BYTE_LITERALS,
                             SectionKind::getMergeableConst4());
    EightByteConstantSection // .literal8
      = Ctx->getMachOSection("__TEXT", "__literal8",
                             MachO::S_8BYTE_LITERALS,
                             SectionKind::getMergeableConst8());
  
    SixteenByteConstantSection // .literal16
        = Ctx->getMachOSection("__TEXT", "__literal16",
                               MachO::S_16BYTE_LITERALS,
                               SectionKind::getMergeableConst16());
  
    ReadOnlySection  // .const
      = Ctx->getMachOSection("__TEXT", "__const", 0,
                             SectionKind::getReadOnly());
  
    TextCoalSection
      = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
                             MachO::S_COALESCED |
                             MachO::S_ATTR_PURE_INSTRUCTIONS,
                             SectionKind::getText());
    ConstTextCoalSection
      = Ctx->getMachOSection("__TEXT", "__const_coal",
                             MachO::S_COALESCED,
                             SectionKind::getReadOnly());
    ConstDataSection  // .const_data
      = Ctx->getMachOSection("__DATA", "__const", 0,
                             SectionKind::getReadOnlyWithRel());
    DataCoalSection
      = Ctx->getMachOSection("__DATA","__datacoal_nt",
                             MachO::S_COALESCED,
                             SectionKind::getDataRel());
    DataCommonSection
      = Ctx->getMachOSection("__DATA","__common",
                             MachO::S_ZEROFILL,
                             SectionKind::getBSS());
    DataBSSSection
      = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
                             SectionKind::getBSS());
  
  
    LazySymbolPointerSection
      = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
                             MachO::S_LAZY_SYMBOL_POINTERS,
                             SectionKind::getMetadata());
    NonLazySymbolPointerSection
      = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
                             MachO::S_NON_LAZY_SYMBOL_POINTERS,
                             SectionKind::getMetadata());
  
    if (RelocM == Reloc::Static) {
      StaticCtorSection
        = Ctx->getMachOSection("__TEXT", "__constructor", 0,
                               SectionKind::getDataRel());
      StaticDtorSection
        = Ctx->getMachOSection("__TEXT", "__destructor", 0,
                               SectionKind::getDataRel());
    } else {
      StaticCtorSection
        = Ctx->getMachOSection("__DATA", "__mod_init_func",
                               MachO::S_MOD_INIT_FUNC_POINTERS,
                               SectionKind::getDataRel());
      StaticDtorSection
        = Ctx->getMachOSection("__DATA", "__mod_term_func",
                               MachO::S_MOD_TERM_FUNC_POINTERS,
                               SectionKind::getDataRel());
    }
  
    // Exception Handling.
    LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
                                       SectionKind::getReadOnlyWithRel());
  
    COFFDebugSymbolsSection = nullptr;
  
    if (useCompactUnwind(T)) {
      CompactUnwindSection =
          Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
                               SectionKind::getReadOnly());
  
      if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
        CompactUnwindDwarfEHFrameOnly = 0x04000000;
      else if (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64)
        CompactUnwindDwarfEHFrameOnly = 0x03000000;
    }
  
    // Debug Information.
    DwarfAccelNamesSection =
      Ctx->getMachOSection("__DWARF", "__apple_names",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfAccelObjCSection =
      Ctx->getMachOSection("__DWARF", "__apple_objc",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    // 16 character section limit...
    DwarfAccelNamespaceSection =
      Ctx->getMachOSection("__DWARF", "__apple_namespac",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfAccelTypesSection =
      Ctx->getMachOSection("__DWARF", "__apple_types",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
  
    DwarfAbbrevSection =
      Ctx->getMachOSection("__DWARF", "__debug_abbrev",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfInfoSection =
      Ctx->getMachOSection("__DWARF", "__debug_info",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfLineSection =
      Ctx->getMachOSection("__DWARF", "__debug_line",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfFrameSection =
      Ctx->getMachOSection("__DWARF", "__debug_frame",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfPubNamesSection =
      Ctx->getMachOSection("__DWARF", "__debug_pubnames",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfPubTypesSection =
      Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfGnuPubNamesSection =
      Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfGnuPubTypesSection =
      Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfStrSection =
      Ctx->getMachOSection("__DWARF", "__debug_str",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfLocSection =
      Ctx->getMachOSection("__DWARF", "__debug_loc",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfARangesSection =
      Ctx->getMachOSection("__DWARF", "__debug_aranges",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfRangesSection =
      Ctx->getMachOSection("__DWARF", "__debug_ranges",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfMacroInfoSection =
      Ctx->getMachOSection("__DWARF", "__debug_macinfo",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    DwarfDebugInlineSection =
      Ctx->getMachOSection("__DWARF", "__debug_inlined",
                           MachO::S_ATTR_DEBUG,
                           SectionKind::getMetadata());
    StackMapSection =
      Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
                           SectionKind::getMetadata());
  
    TLSExtraDataSection = TLSTLVSection;
  }
  
  void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
    switch (T.getArch()) {
    case Triple::mips:
    case Triple::mipsel:
      FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
      break;
    case Triple::mips64:
    case Triple::mips64el:
      FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
      break;
    default:
      FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
      break;
    }
  
    switch (T.getArch()) {
    case Triple::arm:
    case Triple::armeb:
    case Triple::thumb:
    case Triple::thumbeb:
      if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
        break;
      // Fallthrough if not using EHABI
    case Triple::x86:
      PersonalityEncoding = (RelocM == Reloc::PIC_)
       ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
       : dwarf::DW_EH_PE_absptr;
      LSDAEncoding = (RelocM == Reloc::PIC_)
        ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
        : dwarf::DW_EH_PE_absptr;
      TTypeEncoding = (RelocM == Reloc::PIC_)
       ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
       : dwarf::DW_EH_PE_absptr;
      break;
    case Triple::x86_64:
      if (RelocM == Reloc::PIC_) {
        PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
           ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
        LSDAEncoding = dwarf::DW_EH_PE_pcrel |
          (CMModel == CodeModel::Small
           ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
        TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
           ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
      } else {
        PersonalityEncoding =
          (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
          ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
        LSDAEncoding = (CMModel == CodeModel::Small)
          ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
        TTypeEncoding = (CMModel == CodeModel::Small)
          ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
      }
      break;
    case Triple::aarch64:
    case Triple::aarch64_be:
    case Triple::arm64:
    case Triple::arm64_be:
      // The small model guarantees static code/data size < 4GB, but not where it
      // will be in memory. Most of these could end up >2GB away so even a signed
      // pc-relative 32-bit address is insufficient, theoretically.
      if (RelocM == Reloc::PIC_) {
        PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata8;
        LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
        TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata8;
      } else {
        PersonalityEncoding = dwarf::DW_EH_PE_absptr;
        LSDAEncoding = dwarf::DW_EH_PE_absptr;
        TTypeEncoding = dwarf::DW_EH_PE_absptr;
      }
      break;
    case Triple::mips:
    case Triple::mipsel:
      // MIPS uses indirect pointer to refer personality functions, so that the
      // eh_frame section can be read-only.  DW.ref.personality will be generated
      // for relocation.
      PersonalityEncoding = dwarf::DW_EH_PE_indirect;
      break;
    case Triple::ppc64:
    case Triple::ppc64le:
      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
        dwarf::DW_EH_PE_udata8;
      LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
      TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
        dwarf::DW_EH_PE_udata8;
      break;
    case Triple::sparc:
      if (RelocM == Reloc::PIC_) {
        LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
        PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata4;
        TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata4;
      } else {
        LSDAEncoding = dwarf::DW_EH_PE_absptr;
        PersonalityEncoding = dwarf::DW_EH_PE_absptr;
        TTypeEncoding = dwarf::DW_EH_PE_absptr;
      }
      break;
    case Triple::sparcv9:
      LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
      if (RelocM == Reloc::PIC_) {
        PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata4;
        TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata4;
      } else {
        PersonalityEncoding = dwarf::DW_EH_PE_absptr;
        TTypeEncoding = dwarf::DW_EH_PE_absptr;
      }
      break;
    case Triple::systemz:
      // All currently-defined code models guarantee that 4-byte PC-relative
      // values will be in range.
      if (RelocM == Reloc::PIC_) {
        PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata4;
        LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
        TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
          dwarf::DW_EH_PE_sdata4;
      } else {
        PersonalityEncoding = dwarf::DW_EH_PE_absptr;
        LSDAEncoding = dwarf::DW_EH_PE_absptr;
        TTypeEncoding = dwarf::DW_EH_PE_absptr;
      }
      break;
    default:
      break;
    }
  
    // Solaris requires different flags for .eh_frame to seemingly every other
    // platform.
    EHSectionType = ELF::SHT_PROGBITS;
    EHSectionFlags = ELF::SHF_ALLOC;
    if (T.getOS() == Triple::Solaris) {
      if (T.getArch() == Triple::x86_64)
        EHSectionType = ELF::SHT_X86_64_UNWIND;
      else
        EHSectionFlags |= ELF::SHF_WRITE;
    }
  
  
    // ELF
    BSSSection =
      Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
                         ELF::SHF_WRITE | ELF::SHF_ALLOC,
                         SectionKind::getBSS());
  
    TextSection =
      Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
                         ELF::SHF_EXECINSTR |
                         ELF::SHF_ALLOC,
                         SectionKind::getText());
  
    DataSection =
      Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
                         ELF::SHF_WRITE |ELF::SHF_ALLOC,
                         SectionKind::getDataRel());
  
    ReadOnlySection =
      Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC,
                         SectionKind::getReadOnly());
  
    TLSDataSection =
      Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC | ELF::SHF_TLS |
                         ELF::SHF_WRITE,
                         SectionKind::getThreadData());
  
    TLSBSSSection =
      Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
                         ELF::SHF_ALLOC | ELF::SHF_TLS |
                         ELF::SHF_WRITE,
                         SectionKind::getThreadBSS());
  
    DataRelSection =
      Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_WRITE,
                         SectionKind::getDataRel());
  
    DataRelLocalSection =
      Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_WRITE,
                         SectionKind::getDataRelLocal());
  
    DataRelROSection =
      Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_WRITE,
                         SectionKind::getReadOnlyWithRel());
  
    DataRelROLocalSection =
      Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_WRITE,
                         SectionKind::getReadOnlyWithRelLocal());
  
    MergeableConst4Section =
      Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_MERGE,
                         SectionKind::getMergeableConst4());
  
    MergeableConst8Section =
      Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_MERGE,
                         SectionKind::getMergeableConst8());
  
    MergeableConst16Section =
      Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_MERGE,
                         SectionKind::getMergeableConst16());
  
    StaticCtorSection =
      Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_WRITE,
                         SectionKind::getDataRel());
  
    StaticDtorSection =
      Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC |ELF::SHF_WRITE,
                         SectionKind::getDataRel());
  
    // Exception Handling Sections.
  
    // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
    // it contains relocatable pointers.  In PIC mode, this is probably a big
    // runtime hit for C++ apps.  Either the contents of the LSDA need to be
    // adjusted or this should be a data section.
    LSDASection =
      Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
                         ELF::SHF_ALLOC,
                         SectionKind::getReadOnly());
  
    COFFDebugSymbolsSection = nullptr;
  
    // Debug Info Sections.
    DwarfAbbrevSection =
      Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfInfoSection =
      Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfLineSection =
      Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfFrameSection =
      Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfPubNamesSection =
      Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfPubTypesSection =
      Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfGnuPubNamesSection =
      Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfGnuPubTypesSection =
      Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfStrSection =
      Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
                         ELF::SHF_MERGE | ELF::SHF_STRINGS,
                         SectionKind::getMergeable1ByteCString());
    DwarfLocSection =
      Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfARangesSection =
      Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfRangesSection =
      Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfMacroInfoSection =
      Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
  
    // DWARF5 Experimental Debug Info
  
    // Accelerator Tables
    DwarfAccelNamesSection =
      Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfAccelObjCSection =
      Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfAccelNamespaceSection =
      Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfAccelTypesSection =
      Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
  
    // Fission Sections
    DwarfInfoDWOSection =
      Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfAbbrevDWOSection =
      Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfStrDWOSection =
      Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
                         ELF::SHF_MERGE | ELF::SHF_STRINGS,
                         SectionKind::getMergeable1ByteCString());
    DwarfLineDWOSection =
      Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfLocDWOSection =
      Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfStrOffDWOSection =
      Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
    DwarfAddrSection =
      Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
                         SectionKind::getMetadata());
  }
  
  
  void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
    bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
  
    // The object file format cannot represent common symbols with explicit
    // alignments.
    CommDirectiveSupportsAlignment = false;
  
    // COFF
    BSSSection =
      Ctx->getCOFFSection(".bss",
                          COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
                          COFF::IMAGE_SCN_MEM_READ |
                          COFF::IMAGE_SCN_MEM_WRITE,
                          SectionKind::getBSS());
    TextSection =
      Ctx->getCOFFSection(".text",
                          (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT
                                 : (COFF::SectionCharacteristics)0) |
                          COFF::IMAGE_SCN_CNT_CODE |
                          COFF::IMAGE_SCN_MEM_EXECUTE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getText());
    DataSection =
      Ctx->getCOFFSection(".data",
                          COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                          COFF::IMAGE_SCN_MEM_READ |
                          COFF::IMAGE_SCN_MEM_WRITE,
                          SectionKind::getDataRel());
    ReadOnlySection =
      Ctx->getCOFFSection(".rdata",
                          COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getReadOnly());
  
    if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
      StaticCtorSection =
        Ctx->getCOFFSection(".CRT$XCU",
                            COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getReadOnly());
      StaticDtorSection =
        Ctx->getCOFFSection(".CRT$XTX",
                            COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getReadOnly());
    } else {
      StaticCtorSection =
        Ctx->getCOFFSection(".ctors",
                            COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                            COFF::IMAGE_SCN_MEM_READ |
                            COFF::IMAGE_SCN_MEM_WRITE,
                            SectionKind::getDataRel());
      StaticDtorSection =
        Ctx->getCOFFSection(".dtors",
                            COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                            COFF::IMAGE_SCN_MEM_READ |
                            COFF::IMAGE_SCN_MEM_WRITE,
                            SectionKind::getDataRel());
    }
  
    // FIXME: We're emitting LSDA info into a readonly section on COFF, even
    // though it contains relocatable pointers.  In PIC mode, this is probably a
    // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
    // adjusted or this should be a data section.
    assert(T.isOSWindows() && "Windows is the only supported COFF target");
    if (T.getArch() == Triple::x86_64) {
      // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
      LSDASection = 0;
    } else {
      LSDASection = Ctx->getCOFFSection(".gcc_except_table",
                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                                            COFF::IMAGE_SCN_MEM_READ,
                                        SectionKind::getReadOnly());
    }
  
    // Debug info.
    COFFDebugSymbolsSection =
      Ctx->getCOFFSection(".debug$S",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
  
    DwarfAbbrevSection =
      Ctx->getCOFFSection(".debug_abbrev",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfInfoSection =
      Ctx->getCOFFSection(".debug_info",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfLineSection =
      Ctx->getCOFFSection(".debug_line",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfFrameSection =
      Ctx->getCOFFSection(".debug_frame",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfPubNamesSection =
      Ctx->getCOFFSection(".debug_pubnames",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfPubTypesSection =
      Ctx->getCOFFSection(".debug_pubtypes",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfGnuPubNamesSection =
      Ctx->getCOFFSection(".debug_gnu_pubnames",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfGnuPubTypesSection =
      Ctx->getCOFFSection(".debug_gnu_pubtypes",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfStrSection =
      Ctx->getCOFFSection(".debug_str",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfLocSection =
      Ctx->getCOFFSection(".debug_loc",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfARangesSection =
      Ctx->getCOFFSection(".debug_aranges",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfRangesSection =
      Ctx->getCOFFSection(".debug_ranges",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfMacroInfoSection =
      Ctx->getCOFFSection(".debug_macinfo",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
    DwarfInfoDWOSection =
        Ctx->getCOFFSection(".debug_info.dwo",
                            COFF::IMAGE_SCN_MEM_DISCARDABLE |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getMetadata());
    DwarfAbbrevDWOSection =
        Ctx->getCOFFSection(".debug_abbrev.dwo",
                            COFF::IMAGE_SCN_MEM_DISCARDABLE |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getMetadata());
    DwarfStrDWOSection =
        Ctx->getCOFFSection(".debug_str.dwo",
                            COFF::IMAGE_SCN_MEM_DISCARDABLE |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getMetadata());
    DwarfLineDWOSection =
        Ctx->getCOFFSection(".debug_line.dwo",
                            COFF::IMAGE_SCN_MEM_DISCARDABLE |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getMetadata());
    DwarfLocDWOSection =
        Ctx->getCOFFSection(".debug_loc.dwo",
                            COFF::IMAGE_SCN_MEM_DISCARDABLE |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getMetadata());
    DwarfStrOffDWOSection =
        Ctx->getCOFFSection(".debug_str_offsets.dwo",
                            COFF::IMAGE_SCN_MEM_DISCARDABLE |
                            COFF::IMAGE_SCN_MEM_READ,
                            SectionKind::getMetadata());
  
    DwarfAddrSection =
      Ctx->getCOFFSection(".debug_addr",
                          COFF::IMAGE_SCN_MEM_DISCARDABLE |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getMetadata());
  
    DrectveSection =
      Ctx->getCOFFSection(".drectve",
                          COFF::IMAGE_SCN_LNK_INFO |
                          COFF::IMAGE_SCN_LNK_REMOVE,
                          SectionKind::getMetadata());
  
    PDataSection =
      Ctx->getCOFFSection(".pdata",
                          COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getDataRel());
  
    XDataSection =
      Ctx->getCOFFSection(".xdata",
                          COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                          COFF::IMAGE_SCN_MEM_READ,
                          SectionKind::getDataRel());
  
    TLSDataSection =
      Ctx->getCOFFSection(".tls$",
                          COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                          COFF::IMAGE_SCN_MEM_READ |
                          COFF::IMAGE_SCN_MEM_WRITE,
                          SectionKind::getDataRel());
  }
  
  void MCObjectFileInfo::InitMCObjectFileInfo(StringRef T, Reloc::Model relocm,
                                              CodeModel::Model cm,
                                              MCContext &ctx) {
    RelocM = relocm;
    CMModel = cm;
    Ctx = &ctx;
  
    // Common.
    CommDirectiveSupportsAlignment = true;
    SupportsWeakOmittedEHFrame = true;
    SupportsCompactUnwindWithoutEHFrame = false;
  
    PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
        dwarf::DW_EH_PE_absptr;
  
    CompactUnwindDwarfEHFrameOnly = 0;
  
    EHFrameSection = nullptr;             // Created on demand.
    CompactUnwindSection = nullptr;       // Used only by selected targets.
    DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
    DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
    DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
    DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
  
    TT = Triple(T);
  
    Triple::ArchType Arch = TT.getArch();
    // FIXME: Checking for Arch here to filter out bogus triples such as
    // cellspu-apple-darwin. Perhaps we should fix in Triple?
    if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
         Arch == Triple::arm || Arch == Triple::thumb ||
         Arch == Triple::arm64 || Arch == Triple::aarch64 ||
         Arch == Triple::ppc || Arch == Triple::ppc64 ||
         Arch == Triple::UnknownArch) &&
        (TT.isOSDarwin() || TT.isOSBinFormatMachO())) {
      Env = IsMachO;
      InitMachOMCObjectFileInfo(TT);
    } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
                Arch == Triple::arm || Arch == Triple::thumb) &&
               (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
      Env = IsCOFF;
      InitCOFFMCObjectFileInfo(TT);
    } else {
      Env = IsELF;
      InitELFMCObjectFileInfo(TT);
    }
  }
  
  const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
    return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
                              SectionKind::getMetadata(), 0, utostr(Hash));
  }
  
  const MCSection *
  MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
    return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
                              ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
                              utostr(Hash));
  }
  
  void MCObjectFileInfo::InitEHFrameSection() {
    if (Env == IsMachO)
      EHFrameSection =
        Ctx->getMachOSection("__TEXT", "__eh_frame",
                             MachO::S_COALESCED |
                             MachO::S_ATTR_NO_TOC |
                             MachO::S_ATTR_STRIP_STATIC_SYMS |
                             MachO::S_ATTR_LIVE_SUPPORT,
                             SectionKind::getReadOnly());
    else if (Env == IsELF)
      EHFrameSection =
        Ctx->getELFSection(".eh_frame", EHSectionType,
                           EHSectionFlags,
                           SectionKind::getDataRel());
    else
      EHFrameSection =
        Ctx->getCOFFSection(".eh_frame",
                            COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                            COFF::IMAGE_SCN_MEM_READ |
                            COFF::IMAGE_SCN_MEM_WRITE,
                            SectionKind::getDataRel());
  }
  