//===-- MachODump.cpp - Object file 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 file implements the MachO-specific dumper for llvm-objdump. // //===----------------------------------------------------------------------===// #include "llvm-objdump.h" #include "MCFunction.h" #include "llvm/Support/MachO.h" #include "llvm/Object/MachOObject.h" #include "llvm/ADT/OwningPtr.h" #include "llvm/ADT/Triple.h" #include "llvm/ADT/STLExtras.h" #include "llvm/DebugInfo/DIContext.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCDisassembler.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCInstPrinter.h" #include "llvm/MC/MCInstrAnalysis.h" #include "llvm/MC/MCInstrDesc.h" #include "llvm/MC/MCInstrInfo.h" #include "llvm/MC/MCSubtargetInfo.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/Format.h" #include "llvm/Support/GraphWriter.h" #include "llvm/Support/MemoryBuffer.h" #include "llvm/Support/TargetRegistry.h" #include "llvm/Support/TargetSelect.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Support/system_error.h" #include #include using namespace llvm; using namespace object; static cl::opt CFG("cfg", cl::desc("Create a CFG for every symbol in the object file and" "write it to a graphviz file (MachO-only)")); static cl::opt UseDbg("g", cl::desc("Print line information from debug info if available")); static cl::opt DSYMFile("dsym", cl::desc("Use .dSYM file for debug info")); static const Target *GetTarget(const MachOObject *MachOObj) { // Figure out the target triple. llvm::Triple TT("unknown-unknown-unknown"); switch (MachOObj->getHeader().CPUType) { case llvm::MachO::CPUTypeI386: TT.setArch(Triple::ArchType(Triple::x86)); break; case llvm::MachO::CPUTypeX86_64: TT.setArch(Triple::ArchType(Triple::x86_64)); break; case llvm::MachO::CPUTypeARM: TT.setArch(Triple::ArchType(Triple::arm)); break; case llvm::MachO::CPUTypePowerPC: TT.setArch(Triple::ArchType(Triple::ppc)); break; case llvm::MachO::CPUTypePowerPC64: TT.setArch(Triple::ArchType(Triple::ppc64)); break; } TripleName = TT.str(); // Get the target specific parser. std::string Error; const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error); if (TheTarget) return TheTarget; errs() << "llvm-objdump: error: unable to get target for '" << TripleName << "', see --version and --triple.\n"; return 0; } struct Section { char Name[16]; uint64_t Address; uint64_t Size; uint32_t Offset; uint32_t NumRelocs; uint64_t RelocTableOffset; }; struct Symbol { uint64_t Value; uint32_t StringIndex; uint8_t SectionIndex; bool operator<(const Symbol &RHS) const { return Value < RHS.Value; } }; template static Section copySection(const T &Sect) { Section S; memcpy(S.Name, Sect->Name, 16); S.Address = Sect->Address; S.Size = Sect->Size; S.Offset = Sect->Offset; S.NumRelocs = Sect->NumRelocationTableEntries; S.RelocTableOffset = Sect->RelocationTableOffset; return S; } template static Symbol copySymbol(const T &STE) { Symbol S; S.StringIndex = STE->StringIndex; S.SectionIndex = STE->SectionIndex; S.Value = STE->Value; return S; } // Print addtitional information about an address, if available. static void DumpAddress(uint64_t Address, ArrayRef
Sections, MachOObject *MachOObj, raw_ostream &OS) { for (unsigned i = 0; i != Sections.size(); ++i) { uint64_t addr = Address-Sections[i].Address; if (Sections[i].Address <= Address && Sections[i].Address + Sections[i].Size > Address) { StringRef bytes = MachOObj->getData(Sections[i].Offset, Sections[i].Size); // Print constant strings. if (!strcmp(Sections[i].Name, "__cstring")) OS << '"' << bytes.substr(addr, bytes.find('\0', addr)) << '"'; // Print constant CFStrings. if (!strcmp(Sections[i].Name, "__cfstring")) OS << "@\"" << bytes.substr(addr, bytes.find('\0', addr)) << '"'; } } } typedef std::map FunctionMapTy; typedef SmallVector FunctionListTy; static void createMCFunctionAndSaveCalls(StringRef Name, const MCDisassembler *DisAsm, MemoryObject &Object, uint64_t Start, uint64_t End, MCInstrAnalysis *InstrAnalysis, uint64_t Address, raw_ostream &DebugOut, FunctionMapTy &FunctionMap, FunctionListTy &Functions) { SmallVector Calls; MCFunction f = MCFunction::createFunctionFromMC(Name, DisAsm, Object, Start, End, InstrAnalysis, DebugOut, Calls); Functions.push_back(f); FunctionMap[Address] = &Functions.back(); // Add the gathered callees to the map. for (unsigned i = 0, e = Calls.size(); i != e; ++i) FunctionMap.insert(std::make_pair(Calls[i], (MCFunction*)0)); } // Write a graphviz file for the CFG inside an MCFunction. static void emitDOTFile(const char *FileName, const MCFunction &f, MCInstPrinter *IP) { // Start a new dot file. std::string Error; raw_fd_ostream Out(FileName, Error); if (!Error.empty()) { errs() << "llvm-objdump: warning: " << Error << '\n'; return; } Out << "digraph " << f.getName() << " {\n"; Out << "graph [ rankdir = \"LR\" ];\n"; for (MCFunction::iterator i = f.begin(), e = f.end(); i != e; ++i) { bool hasPreds = false; // Only print blocks that have predecessors. // FIXME: Slow. for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe; ++pi) if (pi->second.contains(i->first)) { hasPreds = true; break; } if (!hasPreds && i != f.begin()) continue; Out << '"' << i->first << "\" [ label=\""; // Print instructions. for (unsigned ii = 0, ie = i->second.getInsts().size(); ii != ie; ++ii) { // Escape special chars and print the instruction in mnemonic form. std::string Str; raw_string_ostream OS(Str); IP->printInst(&i->second.getInsts()[ii].Inst, OS, ""); Out << DOT::EscapeString(OS.str()) << '|'; } Out << "\" shape=\"record\" ];\n"; // Add edges. for (MCBasicBlock::succ_iterator si = i->second.succ_begin(), se = i->second.succ_end(); si != se; ++si) Out << i->first << ":o -> " << *si <<":a\n"; } Out << "}\n"; } static void getSectionsAndSymbols(const macho::Header &Header, MachOObject *MachOObj, InMemoryStruct *SymtabLC, std::vector
&Sections, std::vector &Symbols, SmallVectorImpl &FoundFns) { // Make a list of all symbols in the object file. for (unsigned i = 0; i != Header.NumLoadCommands; ++i) { const MachOObject::LoadCommandInfo &LCI = MachOObj->getLoadCommandInfo(i); if (LCI.Command.Type == macho::LCT_Segment) { InMemoryStruct SegmentLC; MachOObj->ReadSegmentLoadCommand(LCI, SegmentLC); // Store the sections in this segment. for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) { InMemoryStruct Sect; MachOObj->ReadSection(LCI, SectNum, Sect); Sections.push_back(copySection(Sect)); } } else if (LCI.Command.Type == macho::LCT_Segment64) { InMemoryStruct Segment64LC; MachOObj->ReadSegment64LoadCommand(LCI, Segment64LC); // Store the sections in this segment. for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) { InMemoryStruct Sect64; MachOObj->ReadSection64(LCI, SectNum, Sect64); Sections.push_back(copySection(Sect64)); } } else if (LCI.Command.Type == macho::LCT_FunctionStarts) { // We found a function starts segment, parse the addresses for later // consumption. InMemoryStruct LLC; MachOObj->ReadLinkeditDataLoadCommand(LCI, LLC); MachOObj->ReadULEB128s(LLC->DataOffset, FoundFns); } } // Store the symbols. if (SymtabLC) { for (unsigned i = 0; i != (*SymtabLC)->NumSymbolTableEntries; ++i) { if (MachOObj->is64Bit()) { InMemoryStruct STE; MachOObj->ReadSymbol64TableEntry((*SymtabLC)->SymbolTableOffset, i, STE); Symbols.push_back(copySymbol(STE)); } else { InMemoryStruct STE; MachOObj->ReadSymbolTableEntry((*SymtabLC)->SymbolTableOffset, i, STE); Symbols.push_back(copySymbol(STE)); } } } } void llvm::DisassembleInputMachO(StringRef Filename) { OwningPtr Buff; if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) { errs() << "llvm-objdump: " << Filename << ": " << ec.message() << "\n"; return; } OwningPtr MachOObj(MachOObject::LoadFromBuffer(Buff.take())); const Target *TheTarget = GetTarget(MachOObj.get()); if (!TheTarget) { // GetTarget prints out stuff. return; } const MCInstrInfo *InstrInfo = TheTarget->createMCInstrInfo(); OwningPtr InstrAnalysis(TheTarget->createMCInstrAnalysis(InstrInfo)); // Set up disassembler. OwningPtr AsmInfo(TheTarget->createMCAsmInfo(TripleName)); OwningPtr STI(TheTarget->createMCSubtargetInfo(TripleName, "", "")); OwningPtr DisAsm(TheTarget->createMCDisassembler(*STI)); int AsmPrinterVariant = AsmInfo->getAssemblerDialect(); OwningPtr IP(TheTarget->createMCInstPrinter( AsmPrinterVariant, *AsmInfo, *STI)); if (!InstrAnalysis || !AsmInfo || !STI || !DisAsm || !IP) { errs() << "error: couldn't initialize disassmbler for target " << TripleName << '\n'; return; } outs() << '\n' << Filename << ":\n\n"; const macho::Header &Header = MachOObj->getHeader(); const MachOObject::LoadCommandInfo *SymtabLCI = 0; // First, find the symbol table segment. for (unsigned i = 0; i != Header.NumLoadCommands; ++i) { const MachOObject::LoadCommandInfo &LCI = MachOObj->getLoadCommandInfo(i); if (LCI.Command.Type == macho::LCT_Symtab) { SymtabLCI = &LCI; break; } } // Read and register the symbol table data. InMemoryStruct SymtabLC; MachOObj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC); MachOObj->RegisterStringTable(*SymtabLC); std::vector
Sections; std::vector Symbols; SmallVector FoundFns; getSectionsAndSymbols(Header, MachOObj.get(), &SymtabLC, Sections, Symbols, FoundFns); // Make a copy of the unsorted symbol list. FIXME: duplication std::vector UnsortedSymbols(Symbols); // Sort the symbols by address, just in case they didn't come in that way. array_pod_sort(Symbols.begin(), Symbols.end()); #ifndef NDEBUG raw_ostream &DebugOut = DebugFlag ? dbgs() : nulls(); #else raw_ostream &DebugOut = nulls(); #endif StringRef DebugAbbrevSection, DebugInfoSection, DebugArangesSection, DebugLineSection, DebugStrSection; OwningPtr diContext; OwningPtr DSYMObj; MachOObject *DbgInfoObj = MachOObj.get(); // Try to find debug info and set up the DIContext for it. if (UseDbg) { ArrayRef
DebugSections = Sections; std::vector
DSYMSections; // A separate DSym file path was specified, parse it as a macho file, // get the sections and supply it to the section name parsing machinery. if (!DSYMFile.empty()) { OwningPtr Buf; if (error_code ec = MemoryBuffer::getFileOrSTDIN(DSYMFile.c_str(), Buf)) { errs() << "llvm-objdump: " << Filename << ": " << ec.message() << '\n'; return; } DSYMObj.reset(MachOObject::LoadFromBuffer(Buf.take())); const macho::Header &Header = DSYMObj->getHeader(); std::vector Symbols; SmallVector FoundFns; getSectionsAndSymbols(Header, DSYMObj.get(), 0, DSYMSections, Symbols, FoundFns); DebugSections = DSYMSections; DbgInfoObj = DSYMObj.get(); } // Find the named debug info sections. for (unsigned SectIdx = 0; SectIdx != DebugSections.size(); SectIdx++) { if (!strcmp(DebugSections[SectIdx].Name, "__debug_abbrev")) DebugAbbrevSection = DbgInfoObj->getData(DebugSections[SectIdx].Offset, DebugSections[SectIdx].Size); else if (!strcmp(DebugSections[SectIdx].Name, "__debug_info")) DebugInfoSection = DbgInfoObj->getData(DebugSections[SectIdx].Offset, DebugSections[SectIdx].Size); else if (!strcmp(DebugSections[SectIdx].Name, "__debug_aranges")) DebugArangesSection = DbgInfoObj->getData(DebugSections[SectIdx].Offset, DebugSections[SectIdx].Size); else if (!strcmp(DebugSections[SectIdx].Name, "__debug_line")) DebugLineSection = DbgInfoObj->getData(DebugSections[SectIdx].Offset, DebugSections[SectIdx].Size); else if (!strcmp(DebugSections[SectIdx].Name, "__debug_str")) DebugStrSection = DbgInfoObj->getData(DebugSections[SectIdx].Offset, DebugSections[SectIdx].Size); } // Setup the DIContext. diContext.reset(DIContext::getDWARFContext(DbgInfoObj->isLittleEndian(), DebugInfoSection, DebugAbbrevSection, DebugArangesSection, DebugLineSection, DebugStrSection)); } FunctionMapTy FunctionMap; FunctionListTy Functions; for (unsigned SectIdx = 0; SectIdx != Sections.size(); SectIdx++) { if (strcmp(Sections[SectIdx].Name, "__text")) continue; // Skip non-text sections // Insert the functions from the function starts segment into our map. uint64_t VMAddr = Sections[SectIdx].Address - Sections[SectIdx].Offset; for (unsigned i = 0, e = FoundFns.size(); i != e; ++i) FunctionMap.insert(std::make_pair(FoundFns[i]+VMAddr, (MCFunction*)0)); StringRef Bytes = MachOObj->getData(Sections[SectIdx].Offset, Sections[SectIdx].Size); StringRefMemoryObject memoryObject(Bytes); bool symbolTableWorked = false; // Parse relocations. std::vector > Relocs; for (unsigned j = 0; j != Sections[SectIdx].NumRelocs; ++j) { InMemoryStruct RE; MachOObj->ReadRelocationEntry(Sections[SectIdx].RelocTableOffset, j, RE); Relocs.push_back(std::make_pair(RE->Word0, RE->Word1 & 0xffffff)); } array_pod_sort(Relocs.begin(), Relocs.end()); // Disassemble symbol by symbol. for (unsigned SymIdx = 0; SymIdx != Symbols.size(); SymIdx++) { // Make sure the symbol is defined in this section. if ((unsigned)Symbols[SymIdx].SectionIndex - 1 != SectIdx) continue; // Start at the address of the symbol relative to the section's address. uint64_t Start = Symbols[SymIdx].Value - Sections[SectIdx].Address; // Stop disassembling either at the beginning of the next symbol or at // the end of the section. uint64_t End = (SymIdx+1 == Symbols.size() || Symbols[SymIdx].SectionIndex != Symbols[SymIdx+1].SectionIndex) ? Sections[SectIdx].Size : Symbols[SymIdx+1].Value - Sections[SectIdx].Address; uint64_t Size; if (Start >= End) continue; symbolTableWorked = true; if (!CFG) { // Normal disassembly, print addresses, bytes and mnemonic form. outs() << MachOObj->getStringAtIndex(Symbols[SymIdx].StringIndex) << ":\n"; DILineInfo lastLine; for (uint64_t Index = Start; Index < End; Index += Size) { MCInst Inst; if (DisAsm->getInstruction(Inst, Size, memoryObject, Index, DebugOut, nulls())) { outs() << format("%8llx:\t", Sections[SectIdx].Address + Index); DumpBytes(StringRef(Bytes.data() + Index, Size)); IP->printInst(&Inst, outs(), ""); // Print debug info. if (diContext) { DILineInfo dli = diContext->getLineInfoForAddress(Sections[SectIdx].Address + Index); // Print valid line info if it changed. if (dli != lastLine && dli.getLine() != 0) outs() << "\t## " << dli.getFileName() << ':' << dli.getLine() << ':' << dli.getColumn(); lastLine = dli; } outs() << "\n"; } else { errs() << "llvm-objdump: warning: invalid instruction encoding\n"; if (Size == 0) Size = 1; // skip illegible bytes } } } else { // Create CFG and use it for disassembly. createMCFunctionAndSaveCalls( MachOObj->getStringAtIndex(Symbols[SymIdx].StringIndex), DisAsm.get(), memoryObject, Start, End, InstrAnalysis.get(), Start, DebugOut, FunctionMap, Functions); } } if (CFG) { if (!symbolTableWorked) { // Reading the symbol table didn't work, create a big __TEXT symbol. createMCFunctionAndSaveCalls("__TEXT", DisAsm.get(), memoryObject, 0, Sections[SectIdx].Size, InstrAnalysis.get(), Sections[SectIdx].Offset, DebugOut, FunctionMap, Functions); } for (std::map::iterator mi = FunctionMap.begin(), me = FunctionMap.end(); mi != me; ++mi) if (mi->second == 0) { // Create functions for the remaining callees we have gathered, // but we didn't find a name for them. SmallVector Calls; MCFunction f = MCFunction::createFunctionFromMC("unknown", DisAsm.get(), memoryObject, mi->first, Sections[SectIdx].Size, InstrAnalysis.get(), DebugOut, Calls); Functions.push_back(f); mi->second = &Functions.back(); for (unsigned i = 0, e = Calls.size(); i != e; ++i) { std::pair p(Calls[i], (MCFunction*)0); if (FunctionMap.insert(p).second) mi = FunctionMap.begin(); } } DenseSet PrintedBlocks; for (unsigned ffi = 0, ffe = Functions.size(); ffi != ffe; ++ffi) { MCFunction &f = Functions[ffi]; for (MCFunction::iterator fi = f.begin(), fe = f.end(); fi != fe; ++fi){ if (!PrintedBlocks.insert(fi->first).second) continue; // We already printed this block. // We assume a block has predecessors when it's the first block after // a symbol. bool hasPreds = FunctionMap.find(fi->first) != FunctionMap.end(); // See if this block has predecessors. // FIXME: Slow. for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe; ++pi) if (pi->second.contains(fi->first)) { hasPreds = true; break; } // No predecessors, this is a data block. Print as .byte directives. if (!hasPreds) { uint64_t End = llvm::next(fi) == fe ? Sections[SectIdx].Size : llvm::next(fi)->first; outs() << "# " << End-fi->first << " bytes of data:\n"; for (unsigned pos = fi->first; pos != End; ++pos) { outs() << format("%8x:\t", Sections[SectIdx].Address + pos); DumpBytes(StringRef(Bytes.data() + pos, 1)); outs() << format("\t.byte 0x%02x\n", (uint8_t)Bytes[pos]); } continue; } if (fi->second.contains(fi->first)) // Print a header for simple loops outs() << "# Loop begin:\n"; DILineInfo lastLine; // Walk over the instructions and print them. for (unsigned ii = 0, ie = fi->second.getInsts().size(); ii != ie; ++ii) { const MCDecodedInst &Inst = fi->second.getInsts()[ii]; // If there's a symbol at this address, print its name. if (FunctionMap.find(Sections[SectIdx].Address + Inst.Address) != FunctionMap.end()) outs() << FunctionMap[Sections[SectIdx].Address + Inst.Address]-> getName() << ":\n"; outs() << format("%8llx:\t", Sections[SectIdx].Address + Inst.Address); DumpBytes(StringRef(Bytes.data() + Inst.Address, Inst.Size)); if (fi->second.contains(fi->first)) // Indent simple loops. outs() << '\t'; IP->printInst(&Inst.Inst, outs(), ""); // Look for relocations inside this instructions, if there is one // print its target and additional information if availbable. for (unsigned j = 0; j != Relocs.size(); ++j) if (Relocs[j].first >= Sections[SectIdx].Address + Inst.Address && Relocs[j].first < Sections[SectIdx].Address + Inst.Address + Inst.Size) { outs() << "\t# " << MachOObj->getStringAtIndex( UnsortedSymbols[Relocs[j].second].StringIndex) << ' '; DumpAddress(UnsortedSymbols[Relocs[j].second].Value, Sections, MachOObj.get(), outs()); } // If this instructions contains an address, see if we can evaluate // it and print additional information. uint64_t targ = InstrAnalysis->evaluateBranch(Inst.Inst, Inst.Address, Inst.Size); if (targ != -1ULL) DumpAddress(targ, Sections, MachOObj.get(), outs()); // Print debug info. if (diContext) { DILineInfo dli = diContext->getLineInfoForAddress(Sections[SectIdx].Address + Inst.Address); // Print valid line info if it changed. if (dli != lastLine && dli.getLine() != 0) outs() << "\t## " << dli.getFileName() << ':' << dli.getLine() << ':' << dli.getColumn(); lastLine = dli; } outs() << '\n'; } } emitDOTFile((f.getName().str() + ".dot").c_str(), f, IP.get()); } } } }