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Diffstat (limited to 'tools/llvm-vtabledump/llvm-vtabledump.cpp')
| -rw-r--r-- | tools/llvm-vtabledump/llvm-vtabledump.cpp | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/tools/llvm-vtabledump/llvm-vtabledump.cpp b/tools/llvm-vtabledump/llvm-vtabledump.cpp new file mode 100644 index 0000000..a21acae --- /dev/null +++ b/tools/llvm-vtabledump/llvm-vtabledump.cpp @@ -0,0 +1,464 @@ +//===- 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; +} |