| //===- llvm-vtabledump.cpp - Dump vtables 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 VTables resident in object files and archives. Note, it currently only |
| // supports MS-ABI style object files. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm-vtabledump.h" |
| #include "Error.h" |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/Object/Archive.h" |
| #include "llvm/Object/ObjectFile.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 <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 |
| |
| static int ReturnValue = EXIT_SUCCESS; |
| |
| namespace llvm { |
| |
| bool error(std::error_code EC) { |
| if (!EC) |
| return false; |
| |
| ReturnValue = EXIT_FAILURE; |
| outs() << "\nError reading file: " << EC.message() << ".\n"; |
| outs().flush(); |
| return true; |
| } |
| |
| } // namespace llvm |
| |
| static void reportError(StringRef Input, StringRef Message) { |
| if (Input == "-") |
| Input = "<stdin>"; |
| |
| errs() << Input << ": " << Message << "\n"; |
| errs().flush(); |
| ReturnValue = EXIT_FAILURE; |
| } |
| |
| static void reportError(StringRef Input, std::error_code EC) { |
| reportError(Input, EC.message()); |
| } |
| |
| static SmallVectorImpl<SectionRef> &getRelocSections(const ObjectFile *Obj, |
| const SectionRef &Sec) { |
| static bool MappingDone = false; |
| static std::map<SectionRef, SmallVector<SectionRef, 1>> SectionRelocMap; |
| if (!MappingDone) { |
| for (const SectionRef &Section : Obj->sections()) { |
| section_iterator Sec2 = Section.getRelocatedSection(); |
| if (Sec2 != Obj->section_end()) |
| SectionRelocMap[*Sec2].push_back(Section); |
| } |
| MappingDone = true; |
| } |
| return SectionRelocMap[Sec]; |
| } |
| |
| static bool 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 : getRelocSections(Obj, 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; |
| StringRef RelocSymName; |
| if (error(RelocSymI->getName(RelocSymName))) |
| return true; |
| uint64_t Offset; |
| if (error(Reloc.getOffset(Offset))) |
| return true; |
| if (Offset >= SymOffset && Offset < SymEnd) { |
| *I = RelocSymName; |
| ++I; |
| } |
| } |
| } |
| return false; |
| } |
| |
| static bool 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 : getRelocSections(Obj, Sec)) { |
| for (const object::RelocationRef &Reloc : SR.relocations()) { |
| const object::symbol_iterator RelocSymI = Reloc.getSymbol(); |
| if (RelocSymI == Obj->symbol_end()) |
| continue; |
| StringRef RelocSymName; |
| if (error(RelocSymI->getName(RelocSymName))) |
| return true; |
| uint64_t Offset; |
| if (error(Reloc.getOffset(Offset))) |
| return true; |
| if (Offset >= SymOffset && Offset < SymEnd) |
| Collection[std::make_pair(SymName, Offset - SymOffset)] = RelocSymName; |
| } |
| } |
| return false; |
| } |
| |
| static void dumpVTables(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; |
| }; |
| std::map<std::pair<StringRef, uint64_t>, StringRef> VFTableEntries; |
| 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<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; |
| |
| uint8_t BytesInAddress = Obj->getBytesInAddress(); |
| |
| for (const object::SymbolRef &Sym : Obj->symbols()) { |
| StringRef SymName; |
| if (error(Sym.getName(SymName))) |
| return; |
| object::section_iterator SecI(Obj->section_begin()); |
| if (error(Sym.getSection(SecI))) |
| return; |
| // 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; |
| if (error(Sec.getContents(SecContents))) |
| return; |
| uint64_t SymAddress, SymSize; |
| if (error(Sym.getAddress(SymAddress)) || error(Sym.getSize(SymSize))) |
| return; |
| 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 = ArrayRef<little32_t>( |
| reinterpret_cast<const little32_t *>(SymContents.data()), 3); |
| StringRef *I = std::begin(COL.Symbols), *E = std::end(COL.Symbols); |
| if (collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, |
| E)) |
| return; |
| COLs[SymName] = COL; |
| } |
| // Class hierarchy descriptors in the MS-ABI start with '??_R3' |
| else if (SymName.startswith("??_R3")) { |
| ClassHierarchyDescriptor CHD; |
| CHD.Data = ArrayRef<little32_t>( |
| reinterpret_cast<const little32_t *>(SymContents.data()), 3); |
| StringRef *I = std::begin(CHD.Symbols), *E = std::end(CHD.Symbols); |
| if (collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, |
| E)) |
| return; |
| 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 = ArrayRef<little32_t>( |
| reinterpret_cast<const little32_t *>(SymContents.data()) + 1, 5); |
| StringRef *I = std::begin(BCD.Symbols), *E = std::end(BCD.Symbols); |
| if (collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, |
| E)) |
| return; |
| 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); |
| if (collectRelocatedSymbols(Obj, Sec, SecAddress, SymAddress, SymSize, I, |
| E)) |
| return; |
| TDs[SymName] = TD; |
| } |
| // 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 std::pair<std::pair<StringRef, uint64_t>, StringRef> &VFTableEntry : |
| VFTableEntries) { |
| StringRef VFTableName = VFTableEntry.first.first; |
| uint64_t Offset = VFTableEntry.first.second; |
| StringRef SymName = VFTableEntry.second; |
| outs() << VFTableName << '[' << Offset << "]: " << SymName << '\n'; |
| } |
| for (const std::pair<StringRef, ArrayRef<little32_t>> &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 std::pair<StringRef, CompleteObjectLocator> &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 std::pair<StringRef, ClassHierarchyDescriptor> &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 std::pair<std::pair<StringRef, uint64_t>, StringRef> &BCAEntry : |
| BCAEntries) { |
| StringRef BCAName = BCAEntry.first.first; |
| uint64_t Offset = BCAEntry.first.second; |
| StringRef SymName = BCAEntry.second; |
| outs() << BCAName << '[' << Offset << "]: " << SymName << '\n'; |
| } |
| for (const std::pair<StringRef, BaseClassDescriptor> &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 std::pair<StringRef, TypeDescriptor> &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 std::pair<std::pair<StringRef, uint64_t>, StringRef> &VTTPair : |
| VTTEntries) { |
| StringRef VTTName = VTTPair.first.first; |
| uint64_t VTTOffset = VTTPair.first.second; |
| StringRef VTTEntry = VTTPair.second; |
| outs() << VTTName << '[' << VTTOffset << "]: " << VTTEntry << '\n'; |
| } |
| for (const std::pair<StringRef, StringRef> &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())) |
| dumpVTables(Obj); |
| else |
| reportError(Arc->getFileName(), |
| vtabledump_error::unrecognized_file_format); |
| } |
| } |
| |
| static void dumpInput(StringRef File) { |
| // If file isn't stdin, check that it exists. |
| if (File != "-" && !sys::fs::exists(File)) { |
| reportError(File, vtabledump_error::file_not_found); |
| return; |
| } |
| |
| // 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)) |
| dumpVTables(Obj); |
| else |
| reportError(File, vtabledump_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 VTable 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 ReturnValue; |
| } |
