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llvm-for-llvmta/tools/llvm-cxxdump/llvm-cxxdump.cpp

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2022-04-25 10:02:23 +02:00
//===- llvm-cxxdump.cpp - Dump C++ data in an Object File -------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// 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/InitLLVM.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/WithColor.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;
WithColor::error(outs(), "") << "reading file: " << EC.message() << ".\n";
outs().flush();
exit(1);
}
LLVM_ATTRIBUTE_NORETURN static void error(Error Err) {
logAllUnhandledErrors(std::move(Err), WithColor::error(outs()),
"reading file: ");
outs().flush();
exit(1);
}
template <typename T>
T unwrapOrError(Expected<T> EO) {
if (!EO)
error(EO.takeError());
return std::move(*EO);
}
} // namespace llvm
static void reportError(StringRef Input, StringRef Message) {
if (Input == "-")
Input = "<stdin>";
WithColor::error(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;
Expected<StringRef> RelocSymName = RelocSymI->getName();
error(errorToErrorCode(RelocSymName.takeError()));
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;
Expected<StringRef> RelocSymName = RelocSymI->getName();
error(errorToErrorCode(RelocSymName.takeError()));
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()) {
Expected<section_iterator> ErrOrSec = Section.getRelocatedSection();
if (!ErrOrSec)
error(ErrOrSec.takeError());
section_iterator Sec2 = *ErrOrSec;
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;
Expected<StringRef> SymNameOrErr = Sym.getName();
error(errorToErrorCode(SymNameOrErr.takeError()));
StringRef SymName = *SymNameOrErr;
Expected<object::section_iterator> SecIOrErr = Sym.getSection();
error(errorToErrorCode(SecIOrErr.takeError()));
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 = unwrapOrError(Sec.getContents());
Expected<uint64_t> SymAddressOrErr = Sym.getAddress();
error(errorToErrorCode(SymAddressOrErr.takeError()));
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) {
Error Err = Error::success();
for (auto &ArcC : Arc->children(Err)) {
Expected<std::unique_ptr<Binary>> ChildOrErr = ArcC.getAsBinary();
if (!ChildOrErr) {
// Ignore non-object files.
if (auto E = isNotObjectErrorInvalidFileType(ChildOrErr.takeError())) {
std::string Buf;
raw_string_ostream OS(Buf);
logAllUnhandledErrors(std::move(E), OS);
OS.flush();
reportError(Arc->getFileName(), Buf);
}
consumeError(ChildOrErr.takeError());
continue;
}
if (ObjectFile *Obj = dyn_cast<ObjectFile>(&*ChildOrErr.get()))
dumpCXXData(Obj);
else
reportError(Arc->getFileName(), cxxdump_error::unrecognized_file_format);
}
if (Err)
error(std::move(Err));
}
static void dumpInput(StringRef File) {
// Attempt to open the binary.
Expected<OwningBinary<Binary>> BinaryOrErr = createBinary(File);
if (!BinaryOrErr) {
auto EC = errorToErrorCode(BinaryOrErr.takeError());
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[]) {
InitLLVM X(argc, argv);
// 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("-");
llvm::for_each(opts::InputFilenames, dumpInput);
return EXIT_SUCCESS;
}