text: //===- llvm-cxxdump.cpp - Dump C++ data in an Object File -------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // Dumps C++ data resident in object files and archives.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm-cxxdump.h"
  #include "Error.h"
  #include "llvm/ADT/ArrayRef.h"
  #include "llvm/Object/Archive.h"
  #include "llvm/Object/ObjectFile.h"
  #include "llvm/Object/SymbolSize.h"
  #include "llvm/Support/Debug.h"
  #include "llvm/Support/Endian.h"
  #include "llvm/Support/FileSystem.h"
  #include "llvm/Support/ManagedStatic.h"
  #include "llvm/Support/PrettyStackTrace.h"
  #include "llvm/Support/Signals.h"
  #include "llvm/Support/TargetRegistry.h"
  #include "llvm/Support/TargetSelect.h"
  #include "llvm/Support/raw_ostream.h"
  #include <map>
  #include <string>
  #include <system_error>
  
  using namespace llvm;
  using namespace llvm::object;
  using namespace llvm::support;
  
  namespace opts {
  cl::list<std::string> InputFilenames(cl::Positional,
                                       cl::desc("<input object files>"),
                                       cl::ZeroOrMore);
  } // namespace opts
  
  namespace llvm {
  
  static void error(std::error_code EC) {
    if (!EC)
      return;
    outs() << "\nError reading file: " << EC.message() << ".\n";
    outs().flush();
    exit(1);
  }
  
  } // namespace llvm
  
  static void reportError(StringRef Input, StringRef Message) {
    if (Input == "-")
      Input = "<stdin>";
    errs() << Input << ": " << Message << "\n";
    errs().flush();
    exit(1);
  }
  
  static void reportError(StringRef Input, std::error_code EC) {
    reportError(Input, EC.message());
  }
  
  static std::map<SectionRef, SmallVector<SectionRef, 1>> SectionRelocMap;
  
  static void collectRelocatedSymbols(const ObjectFile *Obj,
                                      const SectionRef &Sec, uint64_t SecAddress,
                                      uint64_t SymAddress, uint64_t SymSize,
                                      StringRef *I, StringRef *E) {
    uint64_t SymOffset = SymAddress - SecAddress;
    uint64_t SymEnd = SymOffset + SymSize;
    for (const SectionRef &SR : SectionRelocMap[Sec]) {
      for (const object::RelocationRef &Reloc : SR.relocations()) {
        if (I == E)
          break;
        const object::symbol_iterator RelocSymI = Reloc.getSymbol();
        if (RelocSymI == Obj->symbol_end())
          continue;
        ErrorOr<StringRef> RelocSymName = RelocSymI->getName();
        error(RelocSymName.getError());
        uint64_t Offset = Reloc.getOffset();
        if (Offset >= SymOffset && Offset < SymEnd) {
          *I = *RelocSymName;
          ++I;
        }
      }
    }
  }
  
  static void collectRelocationOffsets(
      const ObjectFile *Obj, const SectionRef &Sec, uint64_t SecAddress,
      uint64_t SymAddress, uint64_t SymSize, StringRef SymName,
      std::map<std::pair<StringRef, uint64_t>, StringRef> &Collection) {
    uint64_t SymOffset = SymAddress - SecAddress;
    uint64_t SymEnd = SymOffset + SymSize;
    for (const SectionRef &SR : SectionRelocMap[Sec]) {
      for (const object::RelocationRef &Reloc : SR.relocations()) {
        const object::symbol_iterator RelocSymI = Reloc.getSymbol();
        if (RelocSymI == Obj->symbol_end())
          continue;
        ErrorOr<StringRef> RelocSymName = RelocSymI->getName();
        error(RelocSymName.getError());
        uint64_t Offset = Reloc.getOffset();
        if (Offset >= SymOffset && Offset < SymEnd)
          Collection[std::make_pair(SymName, Offset - SymOffset)] = *RelocSymName;
      }
    }
  }
  
  static void dumpCXXData(const ObjectFile *Obj) {
    struct CompleteObjectLocator {
      StringRef Symbols[2];
      ArrayRef<little32_t> Data;
    };
    struct ClassHierarchyDescriptor {
      StringRef Symbols[1];
      ArrayRef<little32_t> Data;
    };
    struct BaseClassDescriptor {
      StringRef Symbols[2];
      ArrayRef<little32_t> Data;
    };
    struct TypeDescriptor {
      StringRef Symbols[1];
      uint64_t AlwaysZero;
      StringRef MangledName;
    };
    struct ThrowInfo {
      uint32_t Flags;
    };
    struct CatchableTypeArray {
      uint32_t NumEntries;
    };
    struct CatchableType {
      uint32_t Flags;
      uint32_t NonVirtualBaseAdjustmentOffset;
      int32_t VirtualBasePointerOffset;
      uint32_t VirtualBaseAdjustmentOffset;
      uint32_t Size;
      StringRef Symbols[2];
    };
    std::map<std::pair<StringRef, uint64_t>, StringRef> VFTableEntries;
    std::map<std::pair<StringRef, uint64_t>, StringRef> TIEntries;
    std::map<std::pair<StringRef, uint64_t>, StringRef> CTAEntries;
    std::map<StringRef, ArrayRef<little32_t>> VBTables;
    std::map<StringRef, CompleteObjectLocator> COLs;
    std::map<StringRef, ClassHierarchyDescriptor> CHDs;
    std::map<std::pair<StringRef, uint64_t>, StringRef> BCAEntries;
    std::map<StringRef, BaseClassDescriptor> BCDs;
    std::map<StringRef, TypeDescriptor> TDs;
    std::map<StringRef, ThrowInfo> TIs;
    std::map<StringRef, CatchableTypeArray> CTAs;
    std::map<StringRef, CatchableType> CTs;
  
    std::map<std::pair<StringRef, uint64_t>, StringRef> VTableSymEntries;
    std::map<std::pair<StringRef, uint64_t>, int64_t> VTableDataEntries;
    std::map<std::pair<StringRef, uint64_t>, StringRef> VTTEntries;
    std::map<StringRef, StringRef> TINames;
  
    SectionRelocMap.clear();
    for (const SectionRef &Section : Obj->sections()) {
      section_iterator Sec2 = Section.getRelocatedSection();
      if (Sec2 != Obj->section_end())
        SectionRelocMap[*Sec2].push_back(Section);
    }
  
    uint8_t BytesInAddress = Obj->getBytesInAddress();
  
    std::vector<std::pair<SymbolRef, uint64_t>> SymAddr =
        object::computeSymbolSizes(*Obj);
  
    for (auto &P : SymAddr) {
      object::SymbolRef Sym = P.first;
      uint64_t SymSize = P.second;
      ErrorOr<StringRef> SymNameOrErr = Sym.getName();
      error(SymNameOrErr.getError());
      StringRef SymName = *SymNameOrErr;
      ErrorOr<object::section_iterator> SecIOrErr = Sym.getSection();
      error(SecIOrErr.getError());
      object::section_iterator SecI = *SecIOrErr;
      // Skip external symbols.
      if (SecI == Obj->section_end())
        continue;
      const SectionRef &Sec = *SecI;
      // Skip virtual or BSS sections.
      if (Sec.isBSS() || Sec.isVirtual())
        continue;
      StringRef SecContents;
      error(Sec.getContents(SecContents));
      ErrorOr<uint64_t> SymAddressOrErr = Sym.getAddress();
      error(SymAddressOrErr.getError());
      uint64_t SymAddress = *SymAddressOrErr;
      uint64_t SecAddress = Sec.getAddress();
      uint64_t SecSize = Sec.getSize();
      uint64_t SymOffset = SymAddress - SecAddress;
      StringRef SymContents = SecContents.substr(SymOffset, SymSize);
  
      // VFTables in the MS-ABI start with '??_7' and are contained within their
      // own COMDAT section.  We then determine the contents of the VFTable by
      // looking at each relocation in the section.
      if (SymName.startswith("??_7")) {
        // Each relocation either names a virtual method or a thunk.  We note the
        // offset into the section and the symbol used for the relocation.
        collectRelocationOffsets(Obj, Sec, SecAddress, SecAddress, SecSize,
                                 SymName, VFTableEntries);
      }
      // VBTables in the MS-ABI start with '??_8' and are filled with 32-bit
      // offsets of virtual bases.
      else if (SymName.startswith("??_8")) {
        ArrayRef<little32_t> VBTableData(
            reinterpret_cast<const little32_t *>(SymContents.data()),
            SymContents.size() / sizeof(little32_t));
        VBTables[SymName] = VBTableData;
      }
      // Complete object locators in the MS-ABI start with '??_R4'
      else if (SymName.startswith("??_R4")) {
        CompleteObjectLocator COL;
        COL.Data = makeArrayRef(
            reinterpret_cast<const little32_t *>(SymContents.data()), 3);
        StringRef *I = std::begin(COL.Symbols), *E = std::end(COL.Symbols);
        collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, E);
        COLs[SymName] = COL;
      }
      // Class hierarchy descriptors in the MS-ABI start with '??_R3'
      else if (SymName.startswith("??_R3")) {
        ClassHierarchyDescriptor CHD;
        CHD.Data = makeArrayRef(
            reinterpret_cast<const little32_t *>(SymContents.data()), 3);
        StringRef *I = std::begin(CHD.Symbols), *E = std::end(CHD.Symbols);
        collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, E);
        CHDs[SymName] = CHD;
      }
      // Class hierarchy descriptors in the MS-ABI start with '??_R2'
      else if (SymName.startswith("??_R2")) {
        // Each relocation names a base class descriptor.  We note the offset into
        // the section and the symbol used for the relocation.
        collectRelocationOffsets(Obj, Sec, SecAddress, SymAddress, SymSize,
                                 SymName, BCAEntries);
      }
      // Base class descriptors in the MS-ABI start with '??_R1'
      else if (SymName.startswith("??_R1")) {
        BaseClassDescriptor BCD;
        BCD.Data = makeArrayRef(
            reinterpret_cast<const little32_t *>(SymContents.data()) + 1, 5);
        StringRef *I = std::begin(BCD.Symbols), *E = std::end(BCD.Symbols);
        collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, E);
        BCDs[SymName] = BCD;
      }
      // Type descriptors in the MS-ABI start with '??_R0'
      else if (SymName.startswith("??_R0")) {
        const char *DataPtr = SymContents.drop_front(BytesInAddress).data();
        TypeDescriptor TD;
        if (BytesInAddress == 8)
          TD.AlwaysZero = *reinterpret_cast<const little64_t *>(DataPtr);
        else
          TD.AlwaysZero = *reinterpret_cast<const little32_t *>(DataPtr);
        TD.MangledName = SymContents.drop_front(BytesInAddress * 2);
        StringRef *I = std::begin(TD.Symbols), *E = std::end(TD.Symbols);
        collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, E);
        TDs[SymName] = TD;
      }
      // Throw descriptors in the MS-ABI start with '_TI'
      else if (SymName.startswith("_TI") || SymName.startswith("__TI")) {
        ThrowInfo TI;
        TI.Flags = *reinterpret_cast<const little32_t *>(SymContents.data());
        collectRelocationOffsets(Obj, Sec, SecAddress, SymAddress, SymSize,
                                 SymName, TIEntries);
        TIs[SymName] = TI;
      }
      // Catchable type arrays in the MS-ABI start with _CTA or __CTA.
      else if (SymName.startswith("_CTA") || SymName.startswith("__CTA")) {
        CatchableTypeArray CTA;
        CTA.NumEntries =
            *reinterpret_cast<const little32_t *>(SymContents.data());
        collectRelocationOffsets(Obj, Sec, SecAddress, SymAddress, SymSize,
                                 SymName, CTAEntries);
        CTAs[SymName] = CTA;
      }
      // Catchable types in the MS-ABI start with _CT or __CT.
      else if (SymName.startswith("_CT") || SymName.startswith("__CT")) {
        const little32_t *DataPtr =
            reinterpret_cast<const little32_t *>(SymContents.data());
        CatchableType CT;
        CT.Flags = DataPtr[0];
        CT.NonVirtualBaseAdjustmentOffset = DataPtr[2];
        CT.VirtualBasePointerOffset = DataPtr[3];
        CT.VirtualBaseAdjustmentOffset = DataPtr[4];
        CT.Size = DataPtr[5];
        StringRef *I = std::begin(CT.Symbols), *E = std::end(CT.Symbols);
        collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, E);
        CTs[SymName] = CT;
      }
      // Construction vtables in the Itanium ABI start with '_ZTT' or '__ZTT'.
      else if (SymName.startswith("_ZTT") || SymName.startswith("__ZTT")) {
        collectRelocationOffsets(Obj, Sec, SecAddress, SymAddress, SymSize,
                                 SymName, VTTEntries);
      }
      // Typeinfo names in the Itanium ABI start with '_ZTS' or '__ZTS'.
      else if (SymName.startswith("_ZTS") || SymName.startswith("__ZTS")) {
        TINames[SymName] = SymContents.slice(0, SymContents.find('\0'));
      }
      // Vtables in the Itanium ABI start with '_ZTV' or '__ZTV'.
      else if (SymName.startswith("_ZTV") || SymName.startswith("__ZTV")) {
        collectRelocationOffsets(Obj, Sec, SecAddress, SymAddress, SymSize,
                                 SymName, VTableSymEntries);
        for (uint64_t SymOffI = 0; SymOffI < SymSize; SymOffI += BytesInAddress) {
          auto Key = std::make_pair(SymName, SymOffI);
          if (VTableSymEntries.count(Key))
            continue;
          const char *DataPtr =
              SymContents.substr(SymOffI, BytesInAddress).data();
          int64_t VData;
          if (BytesInAddress == 8)
            VData = *reinterpret_cast<const little64_t *>(DataPtr);
          else
            VData = *reinterpret_cast<const little32_t *>(DataPtr);
          VTableDataEntries[Key] = VData;
        }
      }
      // Typeinfo structures in the Itanium ABI start with '_ZTI' or '__ZTI'.
      else if (SymName.startswith("_ZTI") || SymName.startswith("__ZTI")) {
        // FIXME: Do something with these!
      }
    }
    for (const auto &VFTableEntry : VFTableEntries) {
      StringRef VFTableName = VFTableEntry.first.first;
      uint64_t Offset = VFTableEntry.first.second;
      StringRef SymName = VFTableEntry.second;
      outs() << VFTableName << '[' << Offset << "]: " << SymName << '\n';
    }
    for (const auto &VBTable : VBTables) {
      StringRef VBTableName = VBTable.first;
      uint32_t Idx = 0;
      for (little32_t Offset : VBTable.second) {
        outs() << VBTableName << '[' << Idx << "]: " << Offset << '\n';
        Idx += sizeof(Offset);
      }
    }
    for (const auto &COLPair : COLs) {
      StringRef COLName = COLPair.first;
      const CompleteObjectLocator &COL = COLPair.second;
      outs() << COLName << "[IsImageRelative]: " << COL.Data[0] << '\n';
      outs() << COLName << "[OffsetToTop]: " << COL.Data[1] << '\n';
      outs() << COLName << "[VFPtrOffset]: " << COL.Data[2] << '\n';
      outs() << COLName << "[TypeDescriptor]: " << COL.Symbols[0] << '\n';
      outs() << COLName << "[ClassHierarchyDescriptor]: " << COL.Symbols[1]
             << '\n';
    }
    for (const auto &CHDPair : CHDs) {
      StringRef CHDName = CHDPair.first;
      const ClassHierarchyDescriptor &CHD = CHDPair.second;
      outs() << CHDName << "[AlwaysZero]: " << CHD.Data[0] << '\n';
      outs() << CHDName << "[Flags]: " << CHD.Data[1] << '\n';
      outs() << CHDName << "[NumClasses]: " << CHD.Data[2] << '\n';
      outs() << CHDName << "[BaseClassArray]: " << CHD.Symbols[0] << '\n';
    }
    for (const auto &BCAEntry : BCAEntries) {
      StringRef BCAName = BCAEntry.first.first;
      uint64_t Offset = BCAEntry.first.second;
      StringRef SymName = BCAEntry.second;
      outs() << BCAName << '[' << Offset << "]: " << SymName << '\n';
    }
    for (const auto &BCDPair : BCDs) {
      StringRef BCDName = BCDPair.first;
      const BaseClassDescriptor &BCD = BCDPair.second;
      outs() << BCDName << "[TypeDescriptor]: " << BCD.Symbols[0] << '\n';
      outs() << BCDName << "[NumBases]: " << BCD.Data[0] << '\n';
      outs() << BCDName << "[OffsetInVBase]: " << BCD.Data[1] << '\n';
      outs() << BCDName << "[VBPtrOffset]: " << BCD.Data[2] << '\n';
      outs() << BCDName << "[OffsetInVBTable]: " << BCD.Data[3] << '\n';
      outs() << BCDName << "[Flags]: " << BCD.Data[4] << '\n';
      outs() << BCDName << "[ClassHierarchyDescriptor]: " << BCD.Symbols[1]
             << '\n';
    }
    for (const auto &TDPair : TDs) {
      StringRef TDName = TDPair.first;
      const TypeDescriptor &TD = TDPair.second;
      outs() << TDName << "[VFPtr]: " << TD.Symbols[0] << '\n';
      outs() << TDName << "[AlwaysZero]: " << TD.AlwaysZero << '\n';
      outs() << TDName << "[MangledName]: ";
      outs().write_escaped(TD.MangledName.rtrim(StringRef("\0", 1)),
                           /*UseHexEscapes=*/true)
          << '\n';
    }
    for (const auto &TIPair : TIs) {
      StringRef TIName = TIPair.first;
      const ThrowInfo &TI = TIPair.second;
      auto dumpThrowInfoFlag = [&](const char *Name, uint32_t Flag) {
        outs() << TIName << "[Flags." << Name
               << "]: " << (TI.Flags & Flag ? "true" : "false") << '\n';
      };
      auto dumpThrowInfoSymbol = [&](const char *Name, int Offset) {
        outs() << TIName << '[' << Name << "]: ";
        auto Entry = TIEntries.find(std::make_pair(TIName, Offset));
        outs() << (Entry == TIEntries.end() ? "null" : Entry->second) << '\n';
      };
      outs() << TIName << "[Flags]: " << TI.Flags << '\n';
      dumpThrowInfoFlag("Const", 1);
      dumpThrowInfoFlag("Volatile", 2);
      dumpThrowInfoSymbol("CleanupFn", 4);
      dumpThrowInfoSymbol("ForwardCompat", 8);
      dumpThrowInfoSymbol("CatchableTypeArray", 12);
    }
    for (const auto &CTAPair : CTAs) {
      StringRef CTAName = CTAPair.first;
      const CatchableTypeArray &CTA = CTAPair.second;
  
      outs() << CTAName << "[NumEntries]: " << CTA.NumEntries << '\n';
  
      unsigned Idx = 0;
      for (auto I = CTAEntries.lower_bound(std::make_pair(CTAName, 0)),
                E = CTAEntries.upper_bound(std::make_pair(CTAName, UINT64_MAX));
           I != E; ++I)
        outs() << CTAName << '[' << Idx++ << "]: " << I->second << '\n';
    }
    for (const auto &CTPair : CTs) {
      StringRef CTName = CTPair.first;
      const CatchableType &CT = CTPair.second;
      auto dumpCatchableTypeFlag = [&](const char *Name, uint32_t Flag) {
        outs() << CTName << "[Flags." << Name
               << "]: " << (CT.Flags & Flag ? "true" : "false") << '\n';
      };
      outs() << CTName << "[Flags]: " << CT.Flags << '\n';
      dumpCatchableTypeFlag("ScalarType", 1);
      dumpCatchableTypeFlag("VirtualInheritance", 4);
      outs() << CTName << "[TypeDescriptor]: " << CT.Symbols[0] << '\n';
      outs() << CTName << "[NonVirtualBaseAdjustmentOffset]: "
             << CT.NonVirtualBaseAdjustmentOffset << '\n';
      outs() << CTName
             << "[VirtualBasePointerOffset]: " << CT.VirtualBasePointerOffset
             << '\n';
      outs() << CTName << "[VirtualBaseAdjustmentOffset]: "
             << CT.VirtualBaseAdjustmentOffset << '\n';
      outs() << CTName << "[Size]: " << CT.Size << '\n';
      outs() << CTName
             << "[CopyCtor]: " << (CT.Symbols[1].empty() ? "null" : CT.Symbols[1])
             << '\n';
    }
    for (const auto &VTTPair : VTTEntries) {
      StringRef VTTName = VTTPair.first.first;
      uint64_t VTTOffset = VTTPair.first.second;
      StringRef VTTEntry = VTTPair.second;
      outs() << VTTName << '[' << VTTOffset << "]: " << VTTEntry << '\n';
    }
    for (const auto &TIPair : TINames) {
      StringRef TIName = TIPair.first;
      outs() << TIName << ": " << TIPair.second << '\n';
    }
    auto VTableSymI = VTableSymEntries.begin();
    auto VTableSymE = VTableSymEntries.end();
    auto VTableDataI = VTableDataEntries.begin();
    auto VTableDataE = VTableDataEntries.end();
    for (;;) {
      bool SymDone = VTableSymI == VTableSymE;
      bool DataDone = VTableDataI == VTableDataE;
      if (SymDone && DataDone)
        break;
      if (!SymDone && (DataDone || VTableSymI->first < VTableDataI->first)) {
        StringRef VTableName = VTableSymI->first.first;
        uint64_t Offset = VTableSymI->first.second;
        StringRef VTableEntry = VTableSymI->second;
        outs() << VTableName << '[' << Offset << "]: ";
        outs() << VTableEntry;
        outs() << '\n';
        ++VTableSymI;
        continue;
      }
      if (!DataDone && (SymDone || VTableDataI->first < VTableSymI->first)) {
        StringRef VTableName = VTableDataI->first.first;
        uint64_t Offset = VTableDataI->first.second;
        int64_t VTableEntry = VTableDataI->second;
        outs() << VTableName << '[' << Offset << "]: ";
        outs() << VTableEntry;
        outs() << '\n';
        ++VTableDataI;
        continue;
      }
    }
  }
  
  static void dumpArchive(const Archive *Arc) {
    for (const Archive::Child &ArcC : Arc->children()) {
      ErrorOr<std::unique_ptr<Binary>> ChildOrErr = ArcC.getAsBinary();
      if (std::error_code EC = ChildOrErr.getError()) {
        // Ignore non-object files.
        if (EC != object_error::invalid_file_type)
          reportError(Arc->getFileName(), EC.message());
        continue;
      }
  
      if (ObjectFile *Obj = dyn_cast<ObjectFile>(&*ChildOrErr.get()))
        dumpCXXData(Obj);
      else
        reportError(Arc->getFileName(), cxxdump_error::unrecognized_file_format);
    }
  }
  
  static void dumpInput(StringRef File) {
    // Attempt to open the binary.
    ErrorOr<OwningBinary<Binary>> BinaryOrErr = createBinary(File);
    if (std::error_code EC = BinaryOrErr.getError()) {
      reportError(File, EC);
      return;
    }
    Binary &Binary = *BinaryOrErr.get().getBinary();
  
    if (Archive *Arc = dyn_cast<Archive>(&Binary))
      dumpArchive(Arc);
    else if (ObjectFile *Obj = dyn_cast<ObjectFile>(&Binary))
      dumpCXXData(Obj);
    else
      reportError(File, cxxdump_error::unrecognized_file_format);
  }
  
  int main(int argc, const char *argv[]) {
    sys::PrintStackTraceOnErrorSignal();
    PrettyStackTraceProgram X(argc, argv);
    llvm_shutdown_obj Y;
  
    // Initialize targets.
    llvm::InitializeAllTargetInfos();
  
    // Register the target printer for --version.
    cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
  
    cl::ParseCommandLineOptions(argc, argv, "LLVM C++ ABI Data Dumper\n");
  
    // Default to stdin if no filename is specified.
    if (opts::InputFilenames.size() == 0)
      opts::InputFilenames.push_back("-");
  
    std::for_each(opts::InputFilenames.begin(), opts::InputFilenames.end(),
                  dumpInput);
  
    return EXIT_SUCCESS;
  }
  