text: //===-- llvm-nm.cpp - Symbol table dumping utility for llvm ---------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This program is a utility that works like traditional Unix "nm", that is, it
  // prints out the names of symbols in a bitcode or object file, along with some
  // information about each symbol.
  //
  // This "nm" supports many of the features of GNU "nm", including its different
  // output formats.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm/IR/Function.h"
  #include "llvm/IR/GlobalAlias.h"
  #include "llvm/IR/GlobalVariable.h"
  #include "llvm/IR/LLVMContext.h"
  #include "llvm/Object/Archive.h"
  #include "llvm/Object/COFF.h"
  #include "llvm/Object/ELFObjectFile.h"
  #include "llvm/Object/IRObjectFile.h"
  #include "llvm/Object/MachO.h"
  #include "llvm/Object/MachOUniversal.h"
  #include "llvm/Object/ObjectFile.h"
  #include "llvm/Support/COFF.h"
  #include "llvm/Support/CommandLine.h"
  #include "llvm/Support/FileSystem.h"
  #include "llvm/Support/Format.h"
  #include "llvm/Support/ManagedStatic.h"
  #include "llvm/Support/MemoryBuffer.h"
  #include "llvm/Support/PrettyStackTrace.h"
  #include "llvm/Support/Program.h"
  #include "llvm/Support/Signals.h"
  #include "llvm/Support/raw_ostream.h"
  #include "llvm/Support/TargetSelect.h"
  #include <algorithm>
  #include <cctype>
  #include <cerrno>
  #include <cstring>
  #include <system_error>
  #include <vector>
  using namespace llvm;
  using namespace object;
  
  namespace {
  enum OutputFormatTy { bsd, sysv, posix, darwin };
  cl::opt<OutputFormatTy> OutputFormat(
      "format", cl::desc("Specify output format"),
      cl::values(clEnumVal(bsd, "BSD format"), clEnumVal(sysv, "System V format"),
                 clEnumVal(posix, "POSIX.2 format"),
                 clEnumVal(darwin, "Darwin -m format"), clEnumValEnd),
      cl::init(bsd));
  cl::alias OutputFormat2("f", cl::desc("Alias for --format"),
                          cl::aliasopt(OutputFormat));
  
  cl::list<std::string> InputFilenames(cl::Positional, cl::desc("<input files>"),
                                       cl::ZeroOrMore);
  
  cl::opt<bool> UndefinedOnly("undefined-only",
                              cl::desc("Show only undefined symbols"));
  cl::alias UndefinedOnly2("u", cl::desc("Alias for --undefined-only"),
                           cl::aliasopt(UndefinedOnly));
  
  cl::opt<bool> DynamicSyms("dynamic",
                            cl::desc("Display the dynamic symbols instead "
                                     "of normal symbols."));
  cl::alias DynamicSyms2("D", cl::desc("Alias for --dynamic"),
                         cl::aliasopt(DynamicSyms));
  
  cl::opt<bool> DefinedOnly("defined-only",
                            cl::desc("Show only defined symbols"));
  cl::alias DefinedOnly2("U", cl::desc("Alias for --defined-only"),
                         cl::aliasopt(DefinedOnly));
  
  cl::opt<bool> ExternalOnly("extern-only",
                             cl::desc("Show only external symbols"));
  cl::alias ExternalOnly2("g", cl::desc("Alias for --extern-only"),
                          cl::aliasopt(ExternalOnly));
  
  cl::opt<bool> BSDFormat("B", cl::desc("Alias for --format=bsd"));
  cl::opt<bool> POSIXFormat("P", cl::desc("Alias for --format=posix"));
  cl::opt<bool> DarwinFormat("m", cl::desc("Alias for --format=darwin"));
  
  static cl::list<std::string>
      ArchFlags("arch", cl::desc("architecture(s) from a Mach-O file to dump"),
                cl::ZeroOrMore);
  bool ArchAll = false;
  
  cl::opt<bool> PrintFileName(
      "print-file-name",
      cl::desc("Precede each symbol with the object file it came from"));
  
  cl::alias PrintFileNameA("A", cl::desc("Alias for --print-file-name"),
                           cl::aliasopt(PrintFileName));
  cl::alias PrintFileNameo("o", cl::desc("Alias for --print-file-name"),
                           cl::aliasopt(PrintFileName));
  
  cl::opt<bool> DebugSyms("debug-syms",
                          cl::desc("Show all symbols, even debugger only"));
  cl::alias DebugSymsa("a", cl::desc("Alias for --debug-syms"),
                       cl::aliasopt(DebugSyms));
  
  cl::opt<bool> NumericSort("numeric-sort", cl::desc("Sort symbols by address"));
  cl::alias NumericSortn("n", cl::desc("Alias for --numeric-sort"),
                         cl::aliasopt(NumericSort));
  cl::alias NumericSortv("v", cl::desc("Alias for --numeric-sort"),
                         cl::aliasopt(NumericSort));
  
  cl::opt<bool> NoSort("no-sort", cl::desc("Show symbols in order encountered"));
  cl::alias NoSortp("p", cl::desc("Alias for --no-sort"), cl::aliasopt(NoSort));
  
  cl::opt<bool> ReverseSort("reverse-sort", cl::desc("Sort in reverse order"));
  cl::alias ReverseSortr("r", cl::desc("Alias for --reverse-sort"),
                         cl::aliasopt(ReverseSort));
  
  cl::opt<bool> PrintSize("print-size",
                          cl::desc("Show symbol size instead of address"));
  cl::alias PrintSizeS("S", cl::desc("Alias for --print-size"),
                       cl::aliasopt(PrintSize));
  
  cl::opt<bool> SizeSort("size-sort", cl::desc("Sort symbols by size"));
  
  cl::opt<bool> WithoutAliases("without-aliases", cl::Hidden,
                               cl::desc("Exclude aliases from output"));
  
  cl::opt<bool> ArchiveMap("print-armap", cl::desc("Print the archive map"));
  cl::alias ArchiveMaps("M", cl::desc("Alias for --print-armap"),
                        cl::aliasopt(ArchiveMap));
  
  cl::opt<bool> JustSymbolName("just-symbol-name",
                               cl::desc("Print just the symbol's name"));
  cl::alias JustSymbolNames("j", cl::desc("Alias for --just-symbol-name"),
                            cl::aliasopt(JustSymbolName));
  
  // FIXME: This option takes exactly two strings and should be allowed anywhere
  // on the command line.  Such that "llvm-nm -s __TEXT __text foo.o" would work.
  // But that does not as the CommandLine Library does not have a way to make
  // this work.  For now the "-s __TEXT __text" has to be last on the command
  // line.
  cl::list<std::string> SegSect("s", cl::Positional, cl::ZeroOrMore,
                                cl::desc("Dump only symbols from this segment "
                                         "and section name, Mach-O only"));
  
  cl::opt<bool> FormatMachOasHex("x", cl::desc("Print symbol entry in hex, "
                                               "Mach-O only"));
  
  cl::opt<bool> NoLLVMBitcode("no-llvm-bc",
                              cl::desc("Disable LLVM bitcode reader"));
  
  bool PrintAddress = true;
  
  bool MultipleFiles = false;
  
  bool HadError = false;
  
  std::string ToolName;
  }
  
  static void error(Twine Message, Twine Path = Twine()) {
    HadError = true;
    errs() << ToolName << ": " << Path << ": " << Message << ".\n";
  }
  
  static bool error(std::error_code EC, Twine Path = Twine()) {
    if (EC) {
      error(EC.message(), Path);
      return true;
    }
    return false;
  }
  
  namespace {
  struct NMSymbol {
    uint64_t Address;
    uint64_t Size;
    char TypeChar;
    StringRef Name;
    DataRefImpl Symb;
  };
  }
  
  static bool compareSymbolAddress(const NMSymbol &A, const NMSymbol &B) {
    if (!ReverseSort) {
      if (A.Address < B.Address)
        return true;
      else if (A.Address == B.Address && A.Name < B.Name)
        return true;
      else if (A.Address == B.Address && A.Name == B.Name && A.Size < B.Size)
        return true;
      else
        return false;
    } else {
      if (A.Address > B.Address)
        return true;
      else if (A.Address == B.Address && A.Name > B.Name)
        return true;
      else if (A.Address == B.Address && A.Name == B.Name && A.Size > B.Size)
        return true;
      else
        return false;
    }
  }
  
  static bool compareSymbolSize(const NMSymbol &A, const NMSymbol &B) {
    if (!ReverseSort) {
      if (A.Size < B.Size)
        return true;
      else if (A.Size == B.Size && A.Name < B.Name)
        return true;
      else if (A.Size == B.Size && A.Name == B.Name && A.Address < B.Address)
        return true;
      else
        return false;
    } else {
      if (A.Size > B.Size)
        return true;
      else if (A.Size == B.Size && A.Name > B.Name)
        return true;
      else if (A.Size == B.Size && A.Name == B.Name && A.Address > B.Address)
        return true;
      else
        return false;
    }
  }
  
  static bool compareSymbolName(const NMSymbol &A, const NMSymbol &B) {
    if (!ReverseSort) {
      if (A.Name < B.Name)
        return true;
      else if (A.Name == B.Name && A.Size < B.Size)
        return true;
      else if (A.Name == B.Name && A.Size == B.Size && A.Address < B.Address)
        return true;
      else
        return false;
    } else {
      if (A.Name > B.Name)
        return true;
      else if (A.Name == B.Name && A.Size > B.Size)
        return true;
      else if (A.Name == B.Name && A.Size == B.Size && A.Address > B.Address)
        return true;
      else
        return false;
    }
  }
  
  static char isSymbolList64Bit(SymbolicFile &Obj) {
    if (isa<IRObjectFile>(Obj))
      return false;
    else if (isa<COFFObjectFile>(Obj))
      return false;
    else if (MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(&Obj))
      return MachO->is64Bit();
    else if (isa<ELF32LEObjectFile>(Obj))
      return false;
    else if (isa<ELF64LEObjectFile>(Obj))
      return true;
    else if (isa<ELF32BEObjectFile>(Obj))
      return false;
    else if (isa<ELF64BEObjectFile>(Obj))
      return true;
    else
      return false;
  }
  
  static StringRef CurrentFilename;
  typedef std::vector<NMSymbol> SymbolListT;
  static SymbolListT SymbolList;
  
  // darwinPrintSymbol() is used to print a symbol from a Mach-O file when the
  // the OutputFormat is darwin or we are printing Mach-O symbols in hex.  For
  // the darwin format it produces the same output as darwin's nm(1) -m output
  // and when printing Mach-O symbols in hex it produces the same output as
  // darwin's nm(1) -x format.
  static void darwinPrintSymbol(MachOObjectFile *MachO, SymbolListT::iterator I,
                                char *SymbolAddrStr, const char *printBlanks) {
    MachO::mach_header H;
    MachO::mach_header_64 H_64;
    uint32_t Filetype, Flags;
    MachO::nlist_64 STE_64;
    MachO::nlist STE;
    uint8_t NType;
    uint8_t NSect;
    uint16_t NDesc;
    uint32_t NStrx;
    uint64_t NValue;
    if (MachO->is64Bit()) {
      H_64 = MachO->MachOObjectFile::getHeader64();
      Filetype = H_64.filetype;
      Flags = H_64.flags;
      STE_64 = MachO->getSymbol64TableEntry(I->Symb);
      NType = STE_64.n_type;
      NSect = STE_64.n_sect;
      NDesc = STE_64.n_desc;
      NStrx = STE_64.n_strx;
      NValue = STE_64.n_value;
    } else {
      H = MachO->MachOObjectFile::getHeader();
      Filetype = H.filetype;
      Flags = H.flags;
      STE = MachO->getSymbolTableEntry(I->Symb);
      NType = STE.n_type;
      NSect = STE.n_sect;
      NDesc = STE.n_desc;
      NStrx = STE.n_strx;
      NValue = STE.n_value;
    }
  
    // If we are printing Mach-O symbols in hex do that and return.
    if (FormatMachOasHex) {
      char Str[18] = "";
      const char *printFormat;
      if (MachO->is64Bit())
        printFormat = "%016" PRIx64;
      else
        printFormat = "%08" PRIx64;
      format(printFormat, NValue).print(Str, sizeof(Str));
      outs() << Str << ' ';
      format("%02x", NType).print(Str, sizeof(Str));
      outs() << Str << ' ';
      format("%02x", NSect).print(Str, sizeof(Str));
      outs() << Str << ' ';
      format("%04x", NDesc).print(Str, sizeof(Str));
      outs() << Str << ' ';
      format("%08x", NStrx).print(Str, sizeof(Str));
      outs() << Str << ' ';
      outs() << I->Name << "\n";
      return;
    }
  
    if (PrintAddress) {
      if ((NType & MachO::N_TYPE) == MachO::N_INDR)
        strcpy(SymbolAddrStr, printBlanks);
      outs() << SymbolAddrStr << ' ';
    }
  
    switch (NType & MachO::N_TYPE) {
    case MachO::N_UNDF:
      if (NValue != 0) {
        outs() << "(common) ";
        if (MachO::GET_COMM_ALIGN(NDesc) != 0)
          outs() << "(alignment 2^" << (int)MachO::GET_COMM_ALIGN(NDesc) << ") ";
      } else {
        if ((NType & MachO::N_TYPE) == MachO::N_PBUD)
          outs() << "(prebound ";
        else
          outs() << "(";
        if ((NDesc & MachO::REFERENCE_TYPE) ==
            MachO::REFERENCE_FLAG_UNDEFINED_LAZY)
          outs() << "undefined [lazy bound]) ";
        else if ((NDesc & MachO::REFERENCE_TYPE) ==
                 MachO::REFERENCE_FLAG_UNDEFINED_LAZY)
          outs() << "undefined [private lazy bound]) ";
        else if ((NDesc & MachO::REFERENCE_TYPE) ==
                 MachO::REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY)
          outs() << "undefined [private]) ";
        else
          outs() << "undefined) ";
      }
      break;
    case MachO::N_ABS:
      outs() << "(absolute) ";
      break;
    case MachO::N_INDR:
      outs() << "(indirect) ";
      break;
    case MachO::N_SECT: {
      section_iterator Sec = MachO->section_end();
      MachO->getSymbolSection(I->Symb, Sec);
      DataRefImpl Ref = Sec->getRawDataRefImpl();
      StringRef SectionName;
      MachO->getSectionName(Ref, SectionName);
      StringRef SegmentName = MachO->getSectionFinalSegmentName(Ref);
      outs() << "(" << SegmentName << "," << SectionName << ") ";
      break;
    }
    default:
      outs() << "(?) ";
      break;
    }
  
    if (NType & MachO::N_EXT) {
      if (NDesc & MachO::REFERENCED_DYNAMICALLY)
        outs() << "[referenced dynamically] ";
      if (NType & MachO::N_PEXT) {
        if ((NDesc & MachO::N_WEAK_DEF) == MachO::N_WEAK_DEF)
          outs() << "weak private external ";
        else
          outs() << "private external ";
      } else {
        if ((NDesc & MachO::N_WEAK_REF) == MachO::N_WEAK_REF ||
            (NDesc & MachO::N_WEAK_DEF) == MachO::N_WEAK_DEF) {
          if ((NDesc & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF)) ==
              (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
            outs() << "weak external automatically hidden ";
          else
            outs() << "weak external ";
        } else
          outs() << "external ";
      }
    } else {
      if (NType & MachO::N_PEXT)
        outs() << "non-external (was a private external) ";
      else
        outs() << "non-external ";
    }
  
    if (Filetype == MachO::MH_OBJECT &&
        (NDesc & MachO::N_NO_DEAD_STRIP) == MachO::N_NO_DEAD_STRIP)
      outs() << "[no dead strip] ";
  
    if (Filetype == MachO::MH_OBJECT &&
        ((NType & MachO::N_TYPE) != MachO::N_UNDF) &&
        (NDesc & MachO::N_SYMBOL_RESOLVER) == MachO::N_SYMBOL_RESOLVER)
      outs() << "[symbol resolver] ";
  
    if (Filetype == MachO::MH_OBJECT &&
        ((NType & MachO::N_TYPE) != MachO::N_UNDF) &&
        (NDesc & MachO::N_ALT_ENTRY) == MachO::N_ALT_ENTRY)
      outs() << "[alt entry] ";
  
    if ((NDesc & MachO::N_ARM_THUMB_DEF) == MachO::N_ARM_THUMB_DEF)
      outs() << "[Thumb] ";
  
    if ((NType & MachO::N_TYPE) == MachO::N_INDR) {
      outs() << I->Name << " (for ";
      StringRef IndirectName;
      if (MachO->getIndirectName(I->Symb, IndirectName))
        outs() << "?)";
      else
        outs() << IndirectName << ")";
    } else
      outs() << I->Name;
  
    if ((Flags & MachO::MH_TWOLEVEL) == MachO::MH_TWOLEVEL &&
        (((NType & MachO::N_TYPE) == MachO::N_UNDF && NValue == 0) ||
         (NType & MachO::N_TYPE) == MachO::N_PBUD)) {
      uint32_t LibraryOrdinal = MachO::GET_LIBRARY_ORDINAL(NDesc);
      if (LibraryOrdinal != 0) {
        if (LibraryOrdinal == MachO::EXECUTABLE_ORDINAL)
          outs() << " (from executable)";
        else if (LibraryOrdinal == MachO::DYNAMIC_LOOKUP_ORDINAL)
          outs() << " (dynamically looked up)";
        else {
          StringRef LibraryName;
          if (MachO->getLibraryShortNameByIndex(LibraryOrdinal - 1, LibraryName))
            outs() << " (from bad library ordinal " << LibraryOrdinal << ")";
          else
            outs() << " (from " << LibraryName << ")";
        }
      }
    }
  
    outs() << "\n";
  }
  
  // Table that maps Darwin's Mach-O stab constants to strings to allow printing.
  struct DarwinStabName {
    uint8_t NType;
    const char *Name;
  };
  static const struct DarwinStabName DarwinStabNames[] = {
      {MachO::N_GSYM, "GSYM"},
      {MachO::N_FNAME, "FNAME"},
      {MachO::N_FUN, "FUN"},
      {MachO::N_STSYM, "STSYM"},
      {MachO::N_LCSYM, "LCSYM"},
      {MachO::N_BNSYM, "BNSYM"},
      {MachO::N_PC, "PC"},
      {MachO::N_AST, "AST"},
      {MachO::N_OPT, "OPT"},
      {MachO::N_RSYM, "RSYM"},
      {MachO::N_SLINE, "SLINE"},
      {MachO::N_ENSYM, "ENSYM"},
      {MachO::N_SSYM, "SSYM"},
      {MachO::N_SO, "SO"},
      {MachO::N_OSO, "OSO"},
      {MachO::N_LSYM, "LSYM"},
      {MachO::N_BINCL, "BINCL"},
      {MachO::N_SOL, "SOL"},
      {MachO::N_PARAMS, "PARAM"},
      {MachO::N_VERSION, "VERS"},
      {MachO::N_OLEVEL, "OLEV"},
      {MachO::N_PSYM, "PSYM"},
      {MachO::N_EINCL, "EINCL"},
      {MachO::N_ENTRY, "ENTRY"},
      {MachO::N_LBRAC, "LBRAC"},
      {MachO::N_EXCL, "EXCL"},
      {MachO::N_RBRAC, "RBRAC"},
      {MachO::N_BCOMM, "BCOMM"},
      {MachO::N_ECOMM, "ECOMM"},
      {MachO::N_ECOML, "ECOML"},
      {MachO::N_LENG, "LENG"},
      {0, 0}};
  static const char *getDarwinStabString(uint8_t NType) {
    for (unsigned i = 0; DarwinStabNames[i].Name; i++) {
      if (DarwinStabNames[i].NType == NType)
        return DarwinStabNames[i].Name;
    }
    return 0;
  }
  
  // darwinPrintStab() prints the n_sect, n_desc along with a symbolic name of
  // a stab n_type value in a Mach-O file.
  static void darwinPrintStab(MachOObjectFile *MachO, SymbolListT::iterator I) {
    MachO::nlist_64 STE_64;
    MachO::nlist STE;
    uint8_t NType;
    uint8_t NSect;
    uint16_t NDesc;
    if (MachO->is64Bit()) {
      STE_64 = MachO->getSymbol64TableEntry(I->Symb);
      NType = STE_64.n_type;
      NSect = STE_64.n_sect;
      NDesc = STE_64.n_desc;
    } else {
      STE = MachO->getSymbolTableEntry(I->Symb);
      NType = STE.n_type;
      NSect = STE.n_sect;
      NDesc = STE.n_desc;
    }
  
    char Str[18] = "";
    format("%02x", NSect).print(Str, sizeof(Str));
    outs() << ' ' << Str << ' ';
    format("%04x", NDesc).print(Str, sizeof(Str));
    outs() << Str << ' ';
    if (const char *stabString = getDarwinStabString(NType))
      format("%5.5s", stabString).print(Str, sizeof(Str));
    else
      format("   %02x", NType).print(Str, sizeof(Str));
    outs() << Str;
  }
  
  static void sortAndPrintSymbolList(SymbolicFile &Obj, bool printName,
                                     std::string ArchiveName,
                                     std::string ArchitectureName) {
    if (!NoSort) {
      if (NumericSort)
        std::sort(SymbolList.begin(), SymbolList.end(), compareSymbolAddress);
      else if (SizeSort)
        std::sort(SymbolList.begin(), SymbolList.end(), compareSymbolSize);
      else
        std::sort(SymbolList.begin(), SymbolList.end(), compareSymbolName);
    }
  
    if (!PrintFileName) {
      if (OutputFormat == posix && MultipleFiles && printName) {
        outs() << '\n' << CurrentFilename << ":\n";
      } else if (OutputFormat == bsd && MultipleFiles && printName) {
        outs() << "\n" << CurrentFilename << ":\n";
      } else if (OutputFormat == sysv) {
        outs() << "\n\nSymbols from " << CurrentFilename << ":\n\n"
               << "Name                  Value   Class        Type"
               << "         Size   Line  Section\n";
      }
    }
  
    const char *printBlanks, *printFormat;
    if (isSymbolList64Bit(Obj)) {
      printBlanks = "                ";
      printFormat = "%016" PRIx64;
    } else {
      printBlanks = "        ";
      printFormat = "%08" PRIx64;
    }
  
    for (SymbolListT::iterator I = SymbolList.begin(), E = SymbolList.end();
         I != E; ++I) {
      if ((I->TypeChar != 'U') && UndefinedOnly)
        continue;
      if ((I->TypeChar == 'U') && DefinedOnly)
        continue;
      if (SizeSort && !PrintAddress && I->Size == UnknownAddressOrSize)
        continue;
      if (PrintFileName) {
        if (!ArchitectureName.empty())
          outs() << "(for architecture " << ArchitectureName << "):";
        if (!ArchiveName.empty())
          outs() << ArchiveName << ":";
        outs() << CurrentFilename << ": ";
      }
      if (JustSymbolName || (UndefinedOnly && isa<MachOObjectFile>(Obj))) {
        outs() << I->Name << "\n";
        continue;
      }
  
      char SymbolAddrStr[18] = "";
      char SymbolSizeStr[18] = "";
  
      if (OutputFormat == sysv || I->Address == UnknownAddressOrSize)
        strcpy(SymbolAddrStr, printBlanks);
      if (OutputFormat == sysv)
        strcpy(SymbolSizeStr, printBlanks);
  
      if (I->Address != UnknownAddressOrSize)
        format(printFormat, I->Address)
            .print(SymbolAddrStr, sizeof(SymbolAddrStr));
      if (I->Size != UnknownAddressOrSize)
        format(printFormat, I->Size).print(SymbolSizeStr, sizeof(SymbolSizeStr));
  
      // If OutputFormat is darwin or we are printing Mach-O symbols in hex and
      // we have a MachOObjectFile, call darwinPrintSymbol to print as darwin's
      // nm(1) -m output or hex, else if OutputFormat is darwin or we are
      // printing Mach-O symbols in hex and not a Mach-O object fall back to
      // OutputFormat bsd (see below).
      MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(&Obj);
      if ((OutputFormat == darwin || FormatMachOasHex) && MachO) {
        darwinPrintSymbol(MachO, I, SymbolAddrStr, printBlanks);
      } else if (OutputFormat == posix) {
        outs() << I->Name << " " << I->TypeChar << " " << SymbolAddrStr
               << SymbolSizeStr << "\n";
      } else if (OutputFormat == bsd || (OutputFormat == darwin && !MachO)) {
        if (PrintAddress)
          outs() << SymbolAddrStr << ' ';
        if (PrintSize) {
          outs() << SymbolSizeStr;
          if (I->Size != UnknownAddressOrSize)
            outs() << ' ';
        }
        outs() << I->TypeChar;
        if (I->TypeChar == '-' && MachO)
          darwinPrintStab(MachO, I);
        outs() << " " << I->Name << "\n";
      } else if (OutputFormat == sysv) {
        std::string PaddedName(I->Name);
        while (PaddedName.length() < 20)
          PaddedName += " ";
        outs() << PaddedName << "|" << SymbolAddrStr << "|   " << I->TypeChar
               << "  |                  |" << SymbolSizeStr << "|     |\n";
      }
    }
  
    SymbolList.clear();
  }
  
  template <class ELFT>
  static char getSymbolNMTypeChar(ELFObjectFile<ELFT> &Obj,
                                  basic_symbol_iterator I) {
    typedef typename ELFObjectFile<ELFT>::Elf_Sym Elf_Sym;
    typedef typename ELFObjectFile<ELFT>::Elf_Shdr Elf_Shdr;
  
    // OK, this is ELF
    symbol_iterator SymI(I);
  
    DataRefImpl Symb = I->getRawDataRefImpl();
    const Elf_Sym *ESym = Obj.getSymbol(Symb);
    const ELFFile<ELFT> &EF = *Obj.getELFFile();
    const Elf_Shdr *ESec = EF.getSection(ESym);
  
    if (ESec) {
      switch (ESec->sh_type) {
      case ELF::SHT_PROGBITS:
      case ELF::SHT_DYNAMIC:
        switch (ESec->sh_flags) {
        case (ELF::SHF_ALLOC | ELF::SHF_EXECINSTR):
          return 't';
        case (ELF::SHF_TLS | ELF::SHF_ALLOC | ELF::SHF_WRITE):
        case (ELF::SHF_ALLOC | ELF::SHF_WRITE):
          return 'd';
        case ELF::SHF_ALLOC:
        case (ELF::SHF_ALLOC | ELF::SHF_MERGE):
        case (ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::SHF_STRINGS):
          return 'r';
        }
        break;
      case ELF::SHT_NOBITS:
        return 'b';
      }
    }
  
    if (ESym->getType() == ELF::STT_SECTION) {
      StringRef Name;
      if (error(SymI->getName(Name)))
        return '?';
      return StringSwitch<char>(Name)
          .StartsWith(".debug", 'N')
          .StartsWith(".note", 'n')
          .Default('?');
    }
  
    return '?';
  }
  
  static char getSymbolNMTypeChar(COFFObjectFile &Obj, symbol_iterator I) {
    COFFSymbolRef Symb = Obj.getCOFFSymbol(*I);
    // OK, this is COFF.
    symbol_iterator SymI(I);
  
    StringRef Name;
    if (error(SymI->getName(Name)))
      return '?';
  
    char Ret = StringSwitch<char>(Name)
                   .StartsWith(".debug", 'N')
                   .StartsWith(".sxdata", 'N')
                   .Default('?');
  
    if (Ret != '?')
      return Ret;
  
    uint32_t Characteristics = 0;
    if (!COFF::isReservedSectionNumber(Symb.getSectionNumber())) {
      section_iterator SecI = Obj.section_end();
      if (error(SymI->getSection(SecI)))
        return '?';
      const coff_section *Section = Obj.getCOFFSection(*SecI);
      Characteristics = Section->Characteristics;
    }
  
    switch (Symb.getSectionNumber()) {
    case COFF::IMAGE_SYM_DEBUG:
      return 'n';
    default:
      // Check section type.
      if (Characteristics & COFF::IMAGE_SCN_CNT_CODE)
        return 't';
      if (Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
        return Characteristics & COFF::IMAGE_SCN_MEM_WRITE ? 'd' : 'r';
      if (Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
        return 'b';
      if (Characteristics & COFF::IMAGE_SCN_LNK_INFO)
        return 'i';
      // Check for section symbol.
      if (Symb.isSectionDefinition())
        return 's';
    }
  
    return '?';
  }
  
  static uint8_t getNType(MachOObjectFile &Obj, DataRefImpl Symb) {
    if (Obj.is64Bit()) {
      MachO::nlist_64 STE = Obj.getSymbol64TableEntry(Symb);
      return STE.n_type;
    }
    MachO::nlist STE = Obj.getSymbolTableEntry(Symb);
    return STE.n_type;
  }
  
  static char getSymbolNMTypeChar(MachOObjectFile &Obj, basic_symbol_iterator I) {
    DataRefImpl Symb = I->getRawDataRefImpl();
    uint8_t NType = getNType(Obj, Symb);
  
    if (NType & MachO::N_STAB)
      return '-';
  
    switch (NType & MachO::N_TYPE) {
    case MachO::N_ABS:
      return 's';
    case MachO::N_INDR:
      return 'i';
    case MachO::N_SECT: {
      section_iterator Sec = Obj.section_end();
      Obj.getSymbolSection(Symb, Sec);
      DataRefImpl Ref = Sec->getRawDataRefImpl();
      StringRef SectionName;
      Obj.getSectionName(Ref, SectionName);
      StringRef SegmentName = Obj.getSectionFinalSegmentName(Ref);
      if (SegmentName == "__TEXT" && SectionName == "__text")
        return 't';
      else if (SegmentName == "__DATA" && SectionName == "__data")
        return 'd';
      else if (SegmentName == "__DATA" && SectionName == "__bss")
        return 'b';
      else
        return 's';
    }
    }
  
    return '?';
  }
  
  static char getSymbolNMTypeChar(const GlobalValue &GV) {
    if (GV.getType()->getElementType()->isFunctionTy())
      return 't';
    // FIXME: should we print 'b'? At the IR level we cannot be sure if this
    // will be in bss or not, but we could approximate.
    return 'd';
  }
  
  static char getSymbolNMTypeChar(IRObjectFile &Obj, basic_symbol_iterator I) {
    const GlobalValue *GV = Obj.getSymbolGV(I->getRawDataRefImpl());
    if (!GV)
      return 't';
    return getSymbolNMTypeChar(*GV);
  }
  
  template <class ELFT>
  static bool isELFObject(ELFObjectFile<ELFT> &Obj, symbol_iterator I) {
    typedef typename ELFObjectFile<ELFT>::Elf_Sym Elf_Sym;
  
    DataRefImpl Symb = I->getRawDataRefImpl();
    const Elf_Sym *ESym = Obj.getSymbol(Symb);
  
    return ESym->getType() == ELF::STT_OBJECT;
  }
  
  static bool isObject(SymbolicFile &Obj, basic_symbol_iterator I) {
    if (ELF32LEObjectFile *ELF = dyn_cast<ELF32LEObjectFile>(&Obj))
      return isELFObject(*ELF, I);
    if (ELF64LEObjectFile *ELF = dyn_cast<ELF64LEObjectFile>(&Obj))
      return isELFObject(*ELF, I);
    if (ELF32BEObjectFile *ELF = dyn_cast<ELF32BEObjectFile>(&Obj))
      return isELFObject(*ELF, I);
    if (ELF64BEObjectFile *ELF = dyn_cast<ELF64BEObjectFile>(&Obj))
      return isELFObject(*ELF, I);
    return false;
  }
  
  static char getNMTypeChar(SymbolicFile &Obj, basic_symbol_iterator I) {
    uint32_t Symflags = I->getFlags();
    if ((Symflags & object::SymbolRef::SF_Weak) && !isa<MachOObjectFile>(Obj)) {
      char Ret = isObject(Obj, I) ? 'v' : 'w';
      if (!(Symflags & object::SymbolRef::SF_Undefined))
        Ret = toupper(Ret);
      return Ret;
    }
  
    if (Symflags & object::SymbolRef::SF_Undefined)
      return 'U';
  
    if (Symflags & object::SymbolRef::SF_Common)
      return 'C';
  
    char Ret = '?';
    if (Symflags & object::SymbolRef::SF_Absolute)
      Ret = 'a';
    else if (IRObjectFile *IR = dyn_cast<IRObjectFile>(&Obj))
      Ret = getSymbolNMTypeChar(*IR, I);
    else if (COFFObjectFile *COFF = dyn_cast<COFFObjectFile>(&Obj))
      Ret = getSymbolNMTypeChar(*COFF, I);
    else if (MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(&Obj))
      Ret = getSymbolNMTypeChar(*MachO, I);
    else if (ELF32LEObjectFile *ELF = dyn_cast<ELF32LEObjectFile>(&Obj))
      Ret = getSymbolNMTypeChar(*ELF, I);
    else if (ELF64LEObjectFile *ELF = dyn_cast<ELF64LEObjectFile>(&Obj))
      Ret = getSymbolNMTypeChar(*ELF, I);
    else if (ELF32BEObjectFile *ELF = dyn_cast<ELF32BEObjectFile>(&Obj))
      Ret = getSymbolNMTypeChar(*ELF, I);
    else
      Ret = getSymbolNMTypeChar(cast<ELF64BEObjectFile>(Obj), I);
  
    if (Symflags & object::SymbolRef::SF_Global)
      Ret = toupper(Ret);
  
    return Ret;
  }
  
  // getNsectForSegSect() is used to implement the Mach-O "-s segname sectname"
  // option to dump only those symbols from that section in a Mach-O file.
  // It is called once for each Mach-O file from dumpSymbolNamesFromObject()
  // to get the section number for that named section from the command line
  // arguments. It returns the section number for that section in the Mach-O
  // file or zero it is not present.
  static unsigned getNsectForSegSect(MachOObjectFile *Obj) {
    unsigned Nsect = 1;
    for (section_iterator I = Obj->section_begin(), E = Obj->section_end();
         I != E; ++I) {
      DataRefImpl Ref = I->getRawDataRefImpl();
      StringRef SectionName;
      Obj->getSectionName(Ref, SectionName);
      StringRef SegmentName = Obj->getSectionFinalSegmentName(Ref);
      if (SegmentName == SegSect[0] && SectionName == SegSect[1])
        return Nsect;
      Nsect++;
    }
    return 0;
  }
  
  // getNsectInMachO() is used to implement the Mach-O "-s segname sectname"
  // option to dump only those symbols from that section in a Mach-O file.
  // It is called once for each symbol in a Mach-O file from
  // dumpSymbolNamesFromObject() and returns the section number for that symbol
  // if it is in a section, else it returns 0.
  static unsigned getNsectInMachO(MachOObjectFile &Obj, basic_symbol_iterator I) {
    DataRefImpl Symb = I->getRawDataRefImpl();
    if (Obj.is64Bit()) {
      MachO::nlist_64 STE = Obj.getSymbol64TableEntry(Symb);
      if ((STE.n_type & MachO::N_TYPE) == MachO::N_SECT)
        return STE.n_sect;
      return 0;
    }
    MachO::nlist STE = Obj.getSymbolTableEntry(Symb);
    if ((STE.n_type & MachO::N_TYPE) == MachO::N_SECT)
      return STE.n_sect;
    return 0;
  }
  
  static void dumpSymbolNamesFromObject(SymbolicFile &Obj, bool printName,
                                        std::string ArchiveName = std::string(),
                                        std::string ArchitectureName =
                                          std::string()) {
    basic_symbol_iterator IBegin = Obj.symbol_begin();
    basic_symbol_iterator IEnd = Obj.symbol_end();
    if (DynamicSyms) {
      if (!Obj.isELF()) {
        error("File format has no dynamic symbol table", Obj.getFileName());
        return;
      }
      std::pair<symbol_iterator, symbol_iterator> IDyn =
          getELFDynamicSymbolIterators(&Obj);
      IBegin = IDyn.first;
      IEnd = IDyn.second;
    }
    std::string NameBuffer;
    raw_string_ostream OS(NameBuffer);
    // If a "-s segname sectname" option was specified and this is a Mach-O
    // file get the section number for that section in this object file.
    unsigned int Nsect = 0;
    MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(&Obj);
    if (SegSect.size() != 0 && MachO) {
      Nsect = getNsectForSegSect(MachO);
      // If this section is not in the object file no symbols are printed.
      if (Nsect == 0)
        return;
    }
    for (basic_symbol_iterator I = IBegin; I != IEnd; ++I) {
      uint32_t SymFlags = I->getFlags();
      if (!DebugSyms && (SymFlags & SymbolRef::SF_FormatSpecific))
        continue;
      if (WithoutAliases) {
        if (IRObjectFile *IR = dyn_cast<IRObjectFile>(&Obj)) {
          const GlobalValue *GV = IR->getSymbolGV(I->getRawDataRefImpl());
          if (GV && isa<GlobalAlias>(GV))
            continue;
        }
      }
      // If a "-s segname sectname" option was specified and this is a Mach-O
      // file and this section appears in this file, Nsect will be non-zero then
      // see if this symbol is a symbol from that section and if not skip it.
      if (Nsect && Nsect != getNsectInMachO(*MachO, I))
        continue;
      NMSymbol S;
      S.Size = UnknownAddressOrSize;
      S.Address = UnknownAddressOrSize;
      if ((PrintSize || SizeSort) && isa<ObjectFile>(Obj)) {
        symbol_iterator SymI = I;
        if (error(SymI->getSize(S.Size)))
          break;
      }
      if (PrintAddress && isa<ObjectFile>(Obj))
        if (error(symbol_iterator(I)->getAddress(S.Address)))
          break;
      S.TypeChar = getNMTypeChar(Obj, I);
      if (error(I->printName(OS)))
        break;
      OS << '\0';
      S.Symb = I->getRawDataRefImpl();
      SymbolList.push_back(S);
    }
  
    OS.flush();
    const char *P = NameBuffer.c_str();
    for (unsigned I = 0; I < SymbolList.size(); ++I) {
      SymbolList[I].Name = P;
      P += strlen(P) + 1;
    }
  
    CurrentFilename = Obj.getFileName();
    sortAndPrintSymbolList(Obj, printName, ArchiveName, ArchitectureName);
  }
  
  // checkMachOAndArchFlags() checks to see if the SymbolicFile is a Mach-O file
  // and if it is and there is a list of architecture flags is specified then
  // check to make sure this Mach-O file is one of those architectures or all
  // architectures was specificed.  If not then an error is generated and this
  // routine returns false.  Else it returns true.
  static bool checkMachOAndArchFlags(SymbolicFile *O, std::string &Filename) {
    if (isa<MachOObjectFile>(O) && !ArchAll && ArchFlags.size() != 0) {
      MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(O);
      bool ArchFound = false;
      MachO::mach_header H;
      MachO::mach_header_64 H_64;
      Triple T;
      if (MachO->is64Bit()) {
        H_64 = MachO->MachOObjectFile::getHeader64();
        T = MachOObjectFile::getArch(H_64.cputype, H_64.cpusubtype);
      } else {
        H = MachO->MachOObjectFile::getHeader();
        T = MachOObjectFile::getArch(H.cputype, H.cpusubtype);
      }
      unsigned i;
      for (i = 0; i < ArchFlags.size(); ++i) {
        if (ArchFlags[i] == T.getArchName())
          ArchFound = true;
        break;
      }
      if (!ArchFound) {
        error(ArchFlags[i],
              "file: " + Filename + " does not contain architecture");
        return false;
      }
    }
    return true;
  }
  
  static void dumpSymbolNamesFromFile(std::string &Filename) {
    ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
        MemoryBuffer::getFileOrSTDIN(Filename);
    if (error(BufferOrErr.getError(), Filename))
      return;
  
    LLVMContext &Context = getGlobalContext();
    ErrorOr<std::unique_ptr<Binary>> BinaryOrErr = createBinary(
        BufferOrErr.get()->getMemBufferRef(), NoLLVMBitcode ? nullptr : &Context);
    if (error(BinaryOrErr.getError(), Filename))
      return;
    Binary &Bin = *BinaryOrErr.get();
  
    if (Archive *A = dyn_cast<Archive>(&Bin)) {
      if (ArchiveMap) {
        Archive::symbol_iterator I = A->symbol_begin();
        Archive::symbol_iterator E = A->symbol_end();
        if (I != E) {
          outs() << "Archive map\n";
          for (; I != E; ++I) {
            ErrorOr<Archive::child_iterator> C = I->getMember();
            if (error(C.getError()))
              return;
            ErrorOr<StringRef> FileNameOrErr = C.get()->getName();
            if (error(FileNameOrErr.getError()))
              return;
            StringRef SymName = I->getName();
            outs() << SymName << " in " << FileNameOrErr.get() << "\n";
          }
          outs() << "\n";
        }
      }
  
      for (Archive::child_iterator I = A->child_begin(), E = A->child_end();
           I != E; ++I) {
        ErrorOr<std::unique_ptr<Binary>> ChildOrErr = I->getAsBinary(&Context);
        if (ChildOrErr.getError())
          continue;
        if (SymbolicFile *O = dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
          if (!checkMachOAndArchFlags(O, Filename))
            return;
          if (!PrintFileName) {
            outs() << "\n";
            if (isa<MachOObjectFile>(O)) {
              outs() << Filename << "(" << O->getFileName() << ")";
            } else
              outs() << O->getFileName();
            outs() << ":\n";
          }
          dumpSymbolNamesFromObject(*O, false, Filename);
        }
      }
      return;
    }
    if (MachOUniversalBinary *UB = dyn_cast<MachOUniversalBinary>(&Bin)) {
      // If we have a list of architecture flags specified dump only those.
      if (!ArchAll && ArchFlags.size() != 0) {
        // Look for a slice in the universal binary that matches each ArchFlag.
        bool ArchFound;
        for (unsigned i = 0; i < ArchFlags.size(); ++i) {
          ArchFound = false;
          for (MachOUniversalBinary::object_iterator I = UB->begin_objects(),
                                                     E = UB->end_objects();
               I != E; ++I) {
            if (ArchFlags[i] == I->getArchTypeName()) {
              ArchFound = true;
              ErrorOr<std::unique_ptr<ObjectFile>> ObjOrErr =
                  I->getAsObjectFile();
              std::unique_ptr<Archive> A;
              std::string ArchiveName;
              std::string ArchitectureName;
              ArchiveName.clear();
              ArchitectureName.clear();
              if (ObjOrErr) {
                ObjectFile &Obj = *ObjOrErr.get();
                if (ArchFlags.size() > 1) {
                  if (PrintFileName)
                    ArchitectureName = I->getArchTypeName();
                  else
                    outs() << "\n" << Obj.getFileName() << " (for architecture "
                           << I->getArchTypeName() << ")"
                           << ":\n";
                }
                dumpSymbolNamesFromObject(Obj, false, ArchiveName,
                                          ArchitectureName);
              } else if (!I->getAsArchive(A)) {
                for (Archive::child_iterator AI = A->child_begin(),
                                             AE = A->child_end();
                     AI != AE; ++AI) {
                  ErrorOr<std::unique_ptr<Binary>> ChildOrErr =
                      AI->getAsBinary(&Context);
                  if (ChildOrErr.getError())
                    continue;
                  if (SymbolicFile *O =
                          dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
                    if (PrintFileName) {
                      ArchiveName = A->getFileName();
                      if (ArchFlags.size() > 1)
                        ArchitectureName = I->getArchTypeName();
                    } else {
                      outs() << "\n" << A->getFileName();
                      outs() << "(" << O->getFileName() << ")";
                      if (ArchFlags.size() > 1) {
                        outs() << " (for architecture " << I->getArchTypeName()
                               << ")";
                      }
                      outs() << ":\n";
                    }
                    dumpSymbolNamesFromObject(*O, false, ArchiveName,
                                              ArchitectureName);
                  }
                }
              }
            }
          }
          if (!ArchFound) {
            error(ArchFlags[i],
                  "file: " + Filename + " does not contain architecture");
            return;
          }
        }
        return;
      }
      // No architecture flags were specified so if this contains a slice that
      // matches the host architecture dump only that.
      if (!ArchAll) {
        StringRef HostArchName = MachOObjectFile::getHostArch().getArchName();
        for (MachOUniversalBinary::object_iterator I = UB->begin_objects(),
                                                   E = UB->end_objects();
             I != E; ++I) {
          if (HostArchName == I->getArchTypeName()) {
            ErrorOr<std::unique_ptr<ObjectFile>> ObjOrErr = I->getAsObjectFile();
            std::unique_ptr<Archive> A;
            std::string ArchiveName;
            ArchiveName.clear();
            if (ObjOrErr) {
              ObjectFile &Obj = *ObjOrErr.get();
              dumpSymbolNamesFromObject(Obj, false);
            } else if (!I->getAsArchive(A)) {
              for (Archive::child_iterator AI = A->child_begin(),
                                           AE = A->child_end();
                   AI != AE; ++AI) {
                ErrorOr<std::unique_ptr<Binary>> ChildOrErr =
                    AI->getAsBinary(&Context);
                if (ChildOrErr.getError())
                  continue;
                if (SymbolicFile *O =
                        dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
                  if (PrintFileName)
                    ArchiveName = A->getFileName();
                  else
                    outs() << "\n" << A->getFileName() << "(" << O->getFileName()
                           << ")"
                           << ":\n";
                  dumpSymbolNamesFromObject(*O, false, ArchiveName);
                }
              }
            }
            return;
          }
        }
      }
      // Either all architectures have been specified or none have been specified
      // and this does not contain the host architecture so dump all the slices.
      bool moreThanOneArch = UB->getNumberOfObjects() > 1;
      for (MachOUniversalBinary::object_iterator I = UB->begin_objects(),
                                                 E = UB->end_objects();
           I != E; ++I) {
        ErrorOr<std::unique_ptr<ObjectFile>> ObjOrErr = I->getAsObjectFile();
        std::unique_ptr<Archive> A;
        std::string ArchiveName;
        std::string ArchitectureName;
        ArchiveName.clear();
        ArchitectureName.clear();
        if (ObjOrErr) {
          ObjectFile &Obj = *ObjOrErr.get();
          if (PrintFileName) {
            if (isa<MachOObjectFile>(Obj) && moreThanOneArch)
              ArchitectureName = I->getArchTypeName();
          } else {
            if (moreThanOneArch)
              outs() << "\n";
            outs() << Obj.getFileName();
            if (isa<MachOObjectFile>(Obj) && moreThanOneArch)
              outs() << " (for architecture " << I->getArchTypeName() << ")";
            outs() << ":\n";
          }
          dumpSymbolNamesFromObject(Obj, false, ArchiveName, ArchitectureName);
        } else if (!I->getAsArchive(A)) {
          for (Archive::child_iterator AI = A->child_begin(), AE = A->child_end();
               AI != AE; ++AI) {
            ErrorOr<std::unique_ptr<Binary>> ChildOrErr =
                AI->getAsBinary(&Context);
            if (ChildOrErr.getError())
              continue;
            if (SymbolicFile *O = dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
              if (PrintFileName) {
                ArchiveName = A->getFileName();
                if (isa<MachOObjectFile>(O) && moreThanOneArch)
                  ArchitectureName = I->getArchTypeName();
              } else {
                outs() << "\n" << A->getFileName();
                if (isa<MachOObjectFile>(O)) {
                  outs() << "(" << O->getFileName() << ")";
                  if (moreThanOneArch)
                    outs() << " (for architecture " << I->getArchTypeName()
                           << ")";
                } else
                  outs() << ":" << O->getFileName();
                outs() << ":\n";
              }
              dumpSymbolNamesFromObject(*O, false, ArchiveName, ArchitectureName);
            }
          }
        }
      }
      return;
    }
    if (SymbolicFile *O = dyn_cast<SymbolicFile>(&Bin)) {
      if (!checkMachOAndArchFlags(O, Filename))
        return;
      dumpSymbolNamesFromObject(*O, true);
      return;
    }
    error("unrecognizable file type", Filename);
    return;
  }
  
  int main(int argc, char **argv) {
    // Print a stack trace if we signal out.
    sys::PrintStackTraceOnErrorSignal();
    PrettyStackTraceProgram X(argc, argv);
  
    llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
    cl::ParseCommandLineOptions(argc, argv, "llvm symbol table dumper\n");
  
    // llvm-nm only reads binary files.
    if (error(sys::ChangeStdinToBinary()))
      return 1;
  
    llvm::InitializeAllTargetInfos();
    llvm::InitializeAllTargetMCs();
    llvm::InitializeAllAsmParsers();
  
    ToolName = argv[0];
    if (BSDFormat)
      OutputFormat = bsd;
    if (POSIXFormat)
      OutputFormat = posix;
    if (DarwinFormat)
      OutputFormat = darwin;
  
    // The relative order of these is important. If you pass --size-sort it should
    // only print out the size. However, if you pass -S --size-sort, it should
    // print out both the size and address.
    if (SizeSort && !PrintSize)
      PrintAddress = false;
    if (OutputFormat == sysv || SizeSort)
      PrintSize = true;
  
    switch (InputFilenames.size()) {
    case 0:
      InputFilenames.push_back("a.out");
    case 1:
      break;
    default:
      MultipleFiles = true;
    }
  
    for (unsigned i = 0; i < ArchFlags.size(); ++i) {
      if (ArchFlags[i] == "all") {
        ArchAll = true;
      } else {
        if (!MachOObjectFile::isValidArch(ArchFlags[i]))
          error("Unknown architecture named '" + ArchFlags[i] + "'",
                "for the -arch option");
      }
    }
  
    if (SegSect.size() != 0 && SegSect.size() != 2)
      error("bad number of arguments (must be two arguments)",
            "for the -s option");
  
    std::for_each(InputFilenames.begin(), InputFilenames.end(),
                  dumpSymbolNamesFromFile);
  
    if (HadError)
      return 1;
  
    return 0;
  }
  