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Diffstat (limited to 'tools/llvm-objdump/MachODump.cpp')
| -rw-r--r-- | tools/llvm-objdump/MachODump.cpp | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/tools/llvm-objdump/MachODump.cpp b/tools/llvm-objdump/MachODump.cpp new file mode 100644 index 000000000000..3f44b295d32c --- /dev/null +++ b/tools/llvm-objdump/MachODump.cpp @@ -0,0 +1,617 @@ +//===-- 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 <algorithm> +#include <cstring> +using namespace llvm; +using namespace object; + +static cl::opt<bool> + 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<bool> + UseDbg("g", cl::desc("Print line information from debug info if available")); + +static cl::opt<std::string> + 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 <typename T> +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 <typename T> +static Symbol copySymbol(const T &STE) { + Symbol S; + S.StringIndex = STE->StringIndex; + S.SectionIndex = STE->SectionIndex; + S.Value = STE->Value; + return S; +} + +// Print additional information about an address, if available. +static void DumpAddress(uint64_t Address, ArrayRef<Section> 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<uint64_t, MCFunction*> FunctionMapTy; +typedef SmallVector<MCFunction, 16> 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<uint64_t, 16> 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=\"<a>"; + // 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 << "<o>\" 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<macho::SymtabLoadCommand> *SymtabLC, + std::vector<Section> &Sections, + std::vector<Symbol> &Symbols, + SmallVectorImpl<uint64_t> &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<macho::SegmentLoadCommand> SegmentLC; + MachOObj->ReadSegmentLoadCommand(LCI, SegmentLC); + + // Store the sections in this segment. + for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) { + InMemoryStruct<macho::Section> Sect; + MachOObj->ReadSection(LCI, SectNum, Sect); + Sections.push_back(copySection(Sect)); + + } + } else if (LCI.Command.Type == macho::LCT_Segment64) { + InMemoryStruct<macho::Segment64LoadCommand> Segment64LC; + MachOObj->ReadSegment64LoadCommand(LCI, Segment64LC); + + // Store the sections in this segment. + for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; + ++SectNum) { + InMemoryStruct<macho::Section64> 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<macho::LinkeditDataLoadCommand> 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<macho::Symbol64TableEntry> STE; + MachOObj->ReadSymbol64TableEntry((*SymtabLC)->SymbolTableOffset, i, + STE); + Symbols.push_back(copySymbol(STE)); + } else { + InMemoryStruct<macho::SymbolTableEntry> STE; + MachOObj->ReadSymbolTableEntry((*SymtabLC)->SymbolTableOffset, i, + STE); + Symbols.push_back(copySymbol(STE)); + } + } + } +} + +void llvm::DisassembleInputMachO(StringRef Filename) { + OwningPtr<MemoryBuffer> Buff; + + if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) { + errs() << "llvm-objdump: " << Filename << ": " << ec.message() << "\n"; + return; + } + + OwningPtr<MachOObject> MachOObj(MachOObject::LoadFromBuffer(Buff.take())); + + const Target *TheTarget = GetTarget(MachOObj.get()); + if (!TheTarget) { + // GetTarget prints out stuff. + return; + } + OwningPtr<const MCInstrInfo> InstrInfo(TheTarget->createMCInstrInfo()); + OwningPtr<MCInstrAnalysis> + InstrAnalysis(TheTarget->createMCInstrAnalysis(InstrInfo.get())); + + // Set up disassembler. + OwningPtr<const MCAsmInfo> AsmInfo(TheTarget->createMCAsmInfo(TripleName)); + OwningPtr<const MCSubtargetInfo> + STI(TheTarget->createMCSubtargetInfo(TripleName, "", "")); + OwningPtr<const MCDisassembler> DisAsm(TheTarget->createMCDisassembler(*STI)); + int AsmPrinterVariant = AsmInfo->getAssemblerDialect(); + OwningPtr<MCInstPrinter> IP(TheTarget->createMCInstPrinter( + AsmPrinterVariant, *AsmInfo, *STI)); + + if (!InstrAnalysis || !AsmInfo || !STI || !DisAsm || !IP) { + errs() << "error: couldn't initialize disassembler 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<macho::SymtabLoadCommand> SymtabLC; + MachOObj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC); + MachOObj->RegisterStringTable(*SymtabLC); + + std::vector<Section> Sections; + std::vector<Symbol> Symbols; + SmallVector<uint64_t, 8> FoundFns; + + getSectionsAndSymbols(Header, MachOObj.get(), &SymtabLC, Sections, Symbols, + FoundFns); + + // Make a copy of the unsorted symbol list. FIXME: duplication + std::vector<Symbol> 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> diContext; + OwningPtr<MachOObject> DSYMObj; + MachOObject *DbgInfoObj = MachOObj.get(); + // Try to find debug info and set up the DIContext for it. + if (UseDbg) { + ArrayRef<Section> DebugSections = Sections; + std::vector<Section> 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<MemoryBuffer> 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<Symbol> Symbols; + SmallVector<uint64_t, 8> 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<std::pair<uint64_t, uint32_t> > Relocs; + for (unsigned j = 0; j != Sections[SectIdx].NumRelocs; ++j) { + InMemoryStruct<macho::RelocationEntry> 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<uint64_t, MCFunction*>::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<uint64_t, 16> 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<uint64_t, MCFunction*> p(Calls[i], (MCFunction*)0); + if (FunctionMap.insert(p).second) + mi = FunctionMap.begin(); + } + } + + DenseSet<uint64_t> 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 available. + 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()); + } + } + } +} |