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      1 //===-- MachODump.cpp - Object file dumping utility for llvm --------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file implements the MachO-specific dumper for llvm-objdump.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "llvm-objdump.h"
     15 #include "MCFunction.h"
     16 #include "llvm/Support/MachO.h"
     17 #include "llvm/Object/MachO.h"
     18 #include "llvm/ADT/OwningPtr.h"
     19 #include "llvm/ADT/Triple.h"
     20 #include "llvm/ADT/STLExtras.h"
     21 #include "llvm/DebugInfo/DIContext.h"
     22 #include "llvm/MC/MCAsmInfo.h"
     23 #include "llvm/MC/MCDisassembler.h"
     24 #include "llvm/MC/MCInst.h"
     25 #include "llvm/MC/MCInstPrinter.h"
     26 #include "llvm/MC/MCInstrAnalysis.h"
     27 #include "llvm/MC/MCInstrDesc.h"
     28 #include "llvm/MC/MCInstrInfo.h"
     29 #include "llvm/MC/MCRegisterInfo.h"
     30 #include "llvm/MC/MCSubtargetInfo.h"
     31 #include "llvm/Support/CommandLine.h"
     32 #include "llvm/Support/Debug.h"
     33 #include "llvm/Support/Format.h"
     34 #include "llvm/Support/GraphWriter.h"
     35 #include "llvm/Support/MemoryBuffer.h"
     36 #include "llvm/Support/TargetRegistry.h"
     37 #include "llvm/Support/TargetSelect.h"
     38 #include "llvm/Support/raw_ostream.h"
     39 #include "llvm/Support/system_error.h"
     40 #include <algorithm>
     41 #include <cstring>
     42 using namespace llvm;
     43 using namespace object;
     44 
     45 static cl::opt<bool>
     46   CFG("cfg", cl::desc("Create a CFG for every symbol in the object file and"
     47                       "write it to a graphviz file (MachO-only)"));
     48 
     49 static cl::opt<bool>
     50   UseDbg("g", cl::desc("Print line information from debug info if available"));
     51 
     52 static cl::opt<std::string>
     53   DSYMFile("dsym", cl::desc("Use .dSYM file for debug info"));
     54 
     55 static const Target *GetTarget(const MachOObject *MachOObj) {
     56   // Figure out the target triple.
     57   if (TripleName.empty()) {
     58     llvm::Triple TT("unknown-unknown-unknown");
     59     switch (MachOObj->getHeader().CPUType) {
     60     case llvm::MachO::CPUTypeI386:
     61       TT.setArch(Triple::ArchType(Triple::x86));
     62       break;
     63     case llvm::MachO::CPUTypeX86_64:
     64       TT.setArch(Triple::ArchType(Triple::x86_64));
     65       break;
     66     case llvm::MachO::CPUTypeARM:
     67       TT.setArch(Triple::ArchType(Triple::arm));
     68       break;
     69     case llvm::MachO::CPUTypePowerPC:
     70       TT.setArch(Triple::ArchType(Triple::ppc));
     71       break;
     72     case llvm::MachO::CPUTypePowerPC64:
     73       TT.setArch(Triple::ArchType(Triple::ppc64));
     74       break;
     75     }
     76     TripleName = TT.str();
     77   }
     78 
     79   // Get the target specific parser.
     80   std::string Error;
     81   const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
     82   if (TheTarget)
     83     return TheTarget;
     84 
     85   errs() << "llvm-objdump: error: unable to get target for '" << TripleName
     86          << "', see --version and --triple.\n";
     87   return 0;
     88 }
     89 
     90 struct SymbolSorter {
     91   bool operator()(const SymbolRef &A, const SymbolRef &B) {
     92     SymbolRef::Type AType, BType;
     93     A.getType(AType);
     94     B.getType(BType);
     95 
     96     uint64_t AAddr, BAddr;
     97     if (AType != SymbolRef::ST_Function)
     98       AAddr = 0;
     99     else
    100       A.getAddress(AAddr);
    101     if (BType != SymbolRef::ST_Function)
    102       BAddr = 0;
    103     else
    104       B.getAddress(BAddr);
    105     return AAddr < BAddr;
    106   }
    107 };
    108 
    109 // Print additional information about an address, if available.
    110 static void DumpAddress(uint64_t Address, ArrayRef<SectionRef> Sections,
    111                         MachOObject *MachOObj, raw_ostream &OS) {
    112   for (unsigned i = 0; i != Sections.size(); ++i) {
    113     uint64_t SectAddr = 0, SectSize = 0;
    114     Sections[i].getAddress(SectAddr);
    115     Sections[i].getSize(SectSize);
    116     uint64_t addr = SectAddr;
    117     if (SectAddr <= Address &&
    118         SectAddr + SectSize > Address) {
    119       StringRef bytes, name;
    120       Sections[i].getContents(bytes);
    121       Sections[i].getName(name);
    122       // Print constant strings.
    123       if (!name.compare("__cstring"))
    124         OS << '"' << bytes.substr(addr, bytes.find('\0', addr)) << '"';
    125       // Print constant CFStrings.
    126       if (!name.compare("__cfstring"))
    127         OS << "@\"" << bytes.substr(addr, bytes.find('\0', addr)) << '"';
    128     }
    129   }
    130 }
    131 
    132 typedef std::map<uint64_t, MCFunction*> FunctionMapTy;
    133 typedef SmallVector<MCFunction, 16> FunctionListTy;
    134 static void createMCFunctionAndSaveCalls(StringRef Name,
    135                                          const MCDisassembler *DisAsm,
    136                                          MemoryObject &Object, uint64_t Start,
    137                                          uint64_t End,
    138                                          MCInstrAnalysis *InstrAnalysis,
    139                                          uint64_t Address,
    140                                          raw_ostream &DebugOut,
    141                                          FunctionMapTy &FunctionMap,
    142                                          FunctionListTy &Functions) {
    143   SmallVector<uint64_t, 16> Calls;
    144   MCFunction f =
    145     MCFunction::createFunctionFromMC(Name, DisAsm, Object, Start, End,
    146                                      InstrAnalysis, DebugOut, Calls);
    147   Functions.push_back(f);
    148   FunctionMap[Address] = &Functions.back();
    149 
    150   // Add the gathered callees to the map.
    151   for (unsigned i = 0, e = Calls.size(); i != e; ++i)
    152     FunctionMap.insert(std::make_pair(Calls[i], (MCFunction*)0));
    153 }
    154 
    155 // Write a graphviz file for the CFG inside an MCFunction.
    156 static void emitDOTFile(const char *FileName, const MCFunction &f,
    157                         MCInstPrinter *IP) {
    158   // Start a new dot file.
    159   std::string Error;
    160   raw_fd_ostream Out(FileName, Error);
    161   if (!Error.empty()) {
    162     errs() << "llvm-objdump: warning: " << Error << '\n';
    163     return;
    164   }
    165 
    166   Out << "digraph " << f.getName() << " {\n";
    167   Out << "graph [ rankdir = \"LR\" ];\n";
    168   for (MCFunction::iterator i = f.begin(), e = f.end(); i != e; ++i) {
    169     bool hasPreds = false;
    170     // Only print blocks that have predecessors.
    171     // FIXME: Slow.
    172     for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe;
    173         ++pi)
    174       if (pi->second.contains(i->first)) {
    175         hasPreds = true;
    176         break;
    177       }
    178 
    179     if (!hasPreds && i != f.begin())
    180       continue;
    181 
    182     Out << '"' << i->first << "\" [ label=\"<a>";
    183     // Print instructions.
    184     for (unsigned ii = 0, ie = i->second.getInsts().size(); ii != ie;
    185         ++ii) {
    186       // Escape special chars and print the instruction in mnemonic form.
    187       std::string Str;
    188       raw_string_ostream OS(Str);
    189       IP->printInst(&i->second.getInsts()[ii].Inst, OS, "");
    190       Out << DOT::EscapeString(OS.str()) << '|';
    191     }
    192     Out << "<o>\" shape=\"record\" ];\n";
    193 
    194     // Add edges.
    195     for (MCBasicBlock::succ_iterator si = i->second.succ_begin(),
    196         se = i->second.succ_end(); si != se; ++si)
    197       Out << i->first << ":o -> " << *si <<":a\n";
    198   }
    199   Out << "}\n";
    200 }
    201 
    202 static void getSectionsAndSymbols(const macho::Header &Header,
    203                                   MachOObjectFile *MachOObj,
    204                              InMemoryStruct<macho::SymtabLoadCommand> *SymtabLC,
    205                                   std::vector<SectionRef> &Sections,
    206                                   std::vector<SymbolRef> &Symbols,
    207                                   SmallVectorImpl<uint64_t> &FoundFns) {
    208   error_code ec;
    209   for (symbol_iterator SI = MachOObj->begin_symbols(),
    210        SE = MachOObj->end_symbols(); SI != SE; SI.increment(ec))
    211     Symbols.push_back(*SI);
    212 
    213   for (section_iterator SI = MachOObj->begin_sections(),
    214        SE = MachOObj->end_sections(); SI != SE; SI.increment(ec)) {
    215     SectionRef SR = *SI;
    216     StringRef SectName;
    217     SR.getName(SectName);
    218     Sections.push_back(*SI);
    219   }
    220 
    221   for (unsigned i = 0; i != Header.NumLoadCommands; ++i) {
    222     const MachOObject::LoadCommandInfo &LCI =
    223        MachOObj->getObject()->getLoadCommandInfo(i);
    224     if (LCI.Command.Type == macho::LCT_FunctionStarts) {
    225       // We found a function starts segment, parse the addresses for later
    226       // consumption.
    227       InMemoryStruct<macho::LinkeditDataLoadCommand> LLC;
    228       MachOObj->getObject()->ReadLinkeditDataLoadCommand(LCI, LLC);
    229 
    230       MachOObj->getObject()->ReadULEB128s(LLC->DataOffset, FoundFns);
    231     }
    232   }
    233 }
    234 
    235 void llvm::DisassembleInputMachO(StringRef Filename) {
    236   OwningPtr<MemoryBuffer> Buff;
    237 
    238   if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) {
    239     errs() << "llvm-objdump: " << Filename << ": " << ec.message() << "\n";
    240     return;
    241   }
    242 
    243   OwningPtr<MachOObjectFile> MachOOF(static_cast<MachOObjectFile*>(
    244         ObjectFile::createMachOObjectFile(Buff.take())));
    245   MachOObject *MachOObj = MachOOF->getObject();
    246 
    247   const Target *TheTarget = GetTarget(MachOObj);
    248   if (!TheTarget) {
    249     // GetTarget prints out stuff.
    250     return;
    251   }
    252   OwningPtr<const MCInstrInfo> InstrInfo(TheTarget->createMCInstrInfo());
    253   OwningPtr<MCInstrAnalysis>
    254     InstrAnalysis(TheTarget->createMCInstrAnalysis(InstrInfo.get()));
    255 
    256   // Set up disassembler.
    257   OwningPtr<const MCAsmInfo> AsmInfo(TheTarget->createMCAsmInfo(TripleName));
    258   OwningPtr<const MCSubtargetInfo>
    259     STI(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
    260   OwningPtr<const MCDisassembler> DisAsm(TheTarget->createMCDisassembler(*STI));
    261   OwningPtr<const MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
    262   int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
    263   OwningPtr<MCInstPrinter>
    264     IP(TheTarget->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *InstrInfo,
    265                                       *MRI, *STI));
    266 
    267   if (!InstrAnalysis || !AsmInfo || !STI || !DisAsm || !IP) {
    268     errs() << "error: couldn't initialize disassembler for target "
    269            << TripleName << '\n';
    270     return;
    271   }
    272 
    273   outs() << '\n' << Filename << ":\n\n";
    274 
    275   const macho::Header &Header = MachOObj->getHeader();
    276 
    277   const MachOObject::LoadCommandInfo *SymtabLCI = 0;
    278   // First, find the symbol table segment.
    279   for (unsigned i = 0; i != Header.NumLoadCommands; ++i) {
    280     const MachOObject::LoadCommandInfo &LCI = MachOObj->getLoadCommandInfo(i);
    281     if (LCI.Command.Type == macho::LCT_Symtab) {
    282       SymtabLCI = &LCI;
    283       break;
    284     }
    285   }
    286 
    287   // Read and register the symbol table data.
    288   InMemoryStruct<macho::SymtabLoadCommand> SymtabLC;
    289   MachOObj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC);
    290   MachOObj->RegisterStringTable(*SymtabLC);
    291 
    292   std::vector<SectionRef> Sections;
    293   std::vector<SymbolRef> Symbols;
    294   SmallVector<uint64_t, 8> FoundFns;
    295 
    296   getSectionsAndSymbols(Header, MachOOF.get(), &SymtabLC, Sections, Symbols,
    297                         FoundFns);
    298 
    299   // Make a copy of the unsorted symbol list. FIXME: duplication
    300   std::vector<SymbolRef> UnsortedSymbols(Symbols);
    301   // Sort the symbols by address, just in case they didn't come in that way.
    302   std::sort(Symbols.begin(), Symbols.end(), SymbolSorter());
    303 
    304 #ifndef NDEBUG
    305   raw_ostream &DebugOut = DebugFlag ? dbgs() : nulls();
    306 #else
    307   raw_ostream &DebugOut = nulls();
    308 #endif
    309 
    310   StringRef DebugAbbrevSection, DebugInfoSection, DebugArangesSection,
    311             DebugLineSection, DebugStrSection;
    312   OwningPtr<DIContext> diContext;
    313   OwningPtr<MachOObjectFile> DSYMObj;
    314   MachOObject *DbgInfoObj = MachOObj;
    315   // Try to find debug info and set up the DIContext for it.
    316   if (UseDbg) {
    317     ArrayRef<SectionRef> DebugSections = Sections;
    318     std::vector<SectionRef> DSYMSections;
    319 
    320     // A separate DSym file path was specified, parse it as a macho file,
    321     // get the sections and supply it to the section name parsing machinery.
    322     if (!DSYMFile.empty()) {
    323       OwningPtr<MemoryBuffer> Buf;
    324       if (error_code ec = MemoryBuffer::getFileOrSTDIN(DSYMFile.c_str(), Buf)) {
    325         errs() << "llvm-objdump: " << Filename << ": " << ec.message() << '\n';
    326         return;
    327       }
    328       DSYMObj.reset(static_cast<MachOObjectFile*>(
    329             ObjectFile::createMachOObjectFile(Buf.take())));
    330       const macho::Header &Header = DSYMObj->getObject()->getHeader();
    331 
    332       std::vector<SymbolRef> Symbols;
    333       SmallVector<uint64_t, 8> FoundFns;
    334       getSectionsAndSymbols(Header, DSYMObj.get(), 0, DSYMSections, Symbols,
    335                             FoundFns);
    336       DebugSections = DSYMSections;
    337       DbgInfoObj = DSYMObj.get()->getObject();
    338     }
    339 
    340     // Find the named debug info sections.
    341     for (unsigned SectIdx = 0; SectIdx != DebugSections.size(); SectIdx++) {
    342       StringRef SectName;
    343       if (!DebugSections[SectIdx].getName(SectName)) {
    344         if (SectName.equals("__DWARF,__debug_abbrev"))
    345           DebugSections[SectIdx].getContents(DebugAbbrevSection);
    346         else if (SectName.equals("__DWARF,__debug_info"))
    347           DebugSections[SectIdx].getContents(DebugInfoSection);
    348         else if (SectName.equals("__DWARF,__debug_aranges"))
    349           DebugSections[SectIdx].getContents(DebugArangesSection);
    350         else if (SectName.equals("__DWARF,__debug_line"))
    351           DebugSections[SectIdx].getContents(DebugLineSection);
    352         else if (SectName.equals("__DWARF,__debug_str"))
    353           DebugSections[SectIdx].getContents(DebugStrSection);
    354       }
    355     }
    356 
    357     // Setup the DIContext.
    358     diContext.reset(DIContext::getDWARFContext(DbgInfoObj->isLittleEndian(),
    359                                                DebugInfoSection,
    360                                                DebugAbbrevSection,
    361                                                DebugArangesSection,
    362                                                DebugLineSection,
    363                                                DebugStrSection));
    364   }
    365 
    366   FunctionMapTy FunctionMap;
    367   FunctionListTy Functions;
    368 
    369   for (unsigned SectIdx = 0; SectIdx != Sections.size(); SectIdx++) {
    370     StringRef SectName;
    371     if (Sections[SectIdx].getName(SectName) ||
    372         SectName.compare("__TEXT,__text"))
    373       continue; // Skip non-text sections
    374 
    375     // Insert the functions from the function starts segment into our map.
    376     uint64_t VMAddr;
    377     Sections[SectIdx].getAddress(VMAddr);
    378     for (unsigned i = 0, e = FoundFns.size(); i != e; ++i) {
    379       StringRef SectBegin;
    380       Sections[SectIdx].getContents(SectBegin);
    381       uint64_t Offset = (uint64_t)SectBegin.data();
    382       FunctionMap.insert(std::make_pair(VMAddr + FoundFns[i]-Offset,
    383                                         (MCFunction*)0));
    384     }
    385 
    386     StringRef Bytes;
    387     Sections[SectIdx].getContents(Bytes);
    388     StringRefMemoryObject memoryObject(Bytes);
    389     bool symbolTableWorked = false;
    390 
    391     // Parse relocations.
    392     std::vector<std::pair<uint64_t, SymbolRef> > Relocs;
    393     error_code ec;
    394     for (relocation_iterator RI = Sections[SectIdx].begin_relocations(),
    395          RE = Sections[SectIdx].end_relocations(); RI != RE; RI.increment(ec)) {
    396       uint64_t RelocOffset, SectionAddress;
    397       RI->getAddress(RelocOffset);
    398       Sections[SectIdx].getAddress(SectionAddress);
    399       RelocOffset -= SectionAddress;
    400 
    401       SymbolRef RelocSym;
    402       RI->getSymbol(RelocSym);
    403 
    404       Relocs.push_back(std::make_pair(RelocOffset, RelocSym));
    405     }
    406     array_pod_sort(Relocs.begin(), Relocs.end());
    407 
    408     // Disassemble symbol by symbol.
    409     for (unsigned SymIdx = 0; SymIdx != Symbols.size(); SymIdx++) {
    410       StringRef SymName;
    411       Symbols[SymIdx].getName(SymName);
    412 
    413       SymbolRef::Type ST;
    414       Symbols[SymIdx].getType(ST);
    415       if (ST != SymbolRef::ST_Function)
    416         continue;
    417 
    418       // Make sure the symbol is defined in this section.
    419       bool containsSym = false;
    420       Sections[SectIdx].containsSymbol(Symbols[SymIdx], containsSym);
    421       if (!containsSym)
    422         continue;
    423 
    424       // Start at the address of the symbol relative to the section's address.
    425       uint64_t SectionAddress = 0;
    426       uint64_t Start = 0;
    427       Sections[SectIdx].getAddress(SectionAddress);
    428       Symbols[SymIdx].getAddress(Start);
    429       Start -= SectionAddress;
    430 
    431       // Stop disassembling either at the beginning of the next symbol or at
    432       // the end of the section.
    433       bool containsNextSym = true;
    434       uint64_t NextSym = 0;
    435       uint64_t NextSymIdx = SymIdx+1;
    436       while (Symbols.size() > NextSymIdx) {
    437         SymbolRef::Type NextSymType;
    438         Symbols[NextSymIdx].getType(NextSymType);
    439         if (NextSymType == SymbolRef::ST_Function) {
    440           Sections[SectIdx].containsSymbol(Symbols[NextSymIdx],
    441                                            containsNextSym);
    442           Symbols[NextSymIdx].getAddress(NextSym);
    443           NextSym -= SectionAddress;
    444           break;
    445         }
    446         ++NextSymIdx;
    447       }
    448 
    449       uint64_t SectSize;
    450       Sections[SectIdx].getSize(SectSize);
    451       uint64_t End = containsNextSym ?  NextSym : SectSize;
    452       uint64_t Size;
    453 
    454       symbolTableWorked = true;
    455 
    456       if (!CFG) {
    457         // Normal disassembly, print addresses, bytes and mnemonic form.
    458         StringRef SymName;
    459         Symbols[SymIdx].getName(SymName);
    460 
    461         outs() << SymName << ":\n";
    462         DILineInfo lastLine;
    463         for (uint64_t Index = Start; Index < End; Index += Size) {
    464           MCInst Inst;
    465 
    466           if (DisAsm->getInstruction(Inst, Size, memoryObject, Index,
    467                                      DebugOut, nulls())) {
    468             uint64_t SectAddress = 0;
    469             Sections[SectIdx].getAddress(SectAddress);
    470             outs() << format("%8" PRIx64 ":\t", SectAddress + Index);
    471 
    472             DumpBytes(StringRef(Bytes.data() + Index, Size));
    473             IP->printInst(&Inst, outs(), "");
    474 
    475             // Print debug info.
    476             if (diContext) {
    477               DILineInfo dli =
    478                 diContext->getLineInfoForAddress(SectAddress + Index);
    479               // Print valid line info if it changed.
    480               if (dli != lastLine && dli.getLine() != 0)
    481                 outs() << "\t## " << dli.getFileName() << ':'
    482                        << dli.getLine() << ':' << dli.getColumn();
    483               lastLine = dli;
    484             }
    485             outs() << "\n";
    486           } else {
    487             errs() << "llvm-objdump: warning: invalid instruction encoding\n";
    488             if (Size == 0)
    489               Size = 1; // skip illegible bytes
    490           }
    491         }
    492       } else {
    493         // Create CFG and use it for disassembly.
    494         StringRef SymName;
    495         Symbols[SymIdx].getName(SymName);
    496         createMCFunctionAndSaveCalls(
    497             SymName, DisAsm.get(), memoryObject, Start, End,
    498             InstrAnalysis.get(), Start, DebugOut, FunctionMap, Functions);
    499       }
    500     }
    501 
    502     if (CFG) {
    503       if (!symbolTableWorked) {
    504         // Reading the symbol table didn't work, create a big __TEXT symbol.
    505         uint64_t SectSize = 0, SectAddress = 0;
    506         Sections[SectIdx].getSize(SectSize);
    507         Sections[SectIdx].getAddress(SectAddress);
    508         createMCFunctionAndSaveCalls("__TEXT", DisAsm.get(), memoryObject,
    509                                      0, SectSize,
    510                                      InstrAnalysis.get(),
    511                                      SectAddress, DebugOut,
    512                                      FunctionMap, Functions);
    513       }
    514       for (std::map<uint64_t, MCFunction*>::iterator mi = FunctionMap.begin(),
    515            me = FunctionMap.end(); mi != me; ++mi)
    516         if (mi->second == 0) {
    517           // Create functions for the remaining callees we have gathered,
    518           // but we didn't find a name for them.
    519           uint64_t SectSize = 0;
    520           Sections[SectIdx].getSize(SectSize);
    521 
    522           SmallVector<uint64_t, 16> Calls;
    523           MCFunction f =
    524             MCFunction::createFunctionFromMC("unknown", DisAsm.get(),
    525                                              memoryObject, mi->first,
    526                                              SectSize,
    527                                              InstrAnalysis.get(), DebugOut,
    528                                              Calls);
    529           Functions.push_back(f);
    530           mi->second = &Functions.back();
    531           for (unsigned i = 0, e = Calls.size(); i != e; ++i) {
    532             std::pair<uint64_t, MCFunction*> p(Calls[i], (MCFunction*)0);
    533             if (FunctionMap.insert(p).second)
    534               mi = FunctionMap.begin();
    535           }
    536         }
    537 
    538       DenseSet<uint64_t> PrintedBlocks;
    539       for (unsigned ffi = 0, ffe = Functions.size(); ffi != ffe; ++ffi) {
    540         MCFunction &f = Functions[ffi];
    541         for (MCFunction::iterator fi = f.begin(), fe = f.end(); fi != fe; ++fi){
    542           if (!PrintedBlocks.insert(fi->first).second)
    543             continue; // We already printed this block.
    544 
    545           // We assume a block has predecessors when it's the first block after
    546           // a symbol.
    547           bool hasPreds = FunctionMap.find(fi->first) != FunctionMap.end();
    548 
    549           // See if this block has predecessors.
    550           // FIXME: Slow.
    551           for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe;
    552               ++pi)
    553             if (pi->second.contains(fi->first)) {
    554               hasPreds = true;
    555               break;
    556             }
    557 
    558           uint64_t SectSize = 0, SectAddress;
    559           Sections[SectIdx].getSize(SectSize);
    560           Sections[SectIdx].getAddress(SectAddress);
    561 
    562           // No predecessors, this is a data block. Print as .byte directives.
    563           if (!hasPreds) {
    564             uint64_t End = llvm::next(fi) == fe ? SectSize :
    565                                                   llvm::next(fi)->first;
    566             outs() << "# " << End-fi->first << " bytes of data:\n";
    567             for (unsigned pos = fi->first; pos != End; ++pos) {
    568               outs() << format("%8x:\t", SectAddress + pos);
    569               DumpBytes(StringRef(Bytes.data() + pos, 1));
    570               outs() << format("\t.byte 0x%02x\n", (uint8_t)Bytes[pos]);
    571             }
    572             continue;
    573           }
    574 
    575           if (fi->second.contains(fi->first)) // Print a header for simple loops
    576             outs() << "# Loop begin:\n";
    577 
    578           DILineInfo lastLine;
    579           // Walk over the instructions and print them.
    580           for (unsigned ii = 0, ie = fi->second.getInsts().size(); ii != ie;
    581                ++ii) {
    582             const MCDecodedInst &Inst = fi->second.getInsts()[ii];
    583 
    584             // If there's a symbol at this address, print its name.
    585             if (FunctionMap.find(SectAddress + Inst.Address) !=
    586                 FunctionMap.end())
    587               outs() << FunctionMap[SectAddress + Inst.Address]-> getName()
    588                      << ":\n";
    589 
    590             outs() << format("%8" PRIx64 ":\t", SectAddress + Inst.Address);
    591             DumpBytes(StringRef(Bytes.data() + Inst.Address, Inst.Size));
    592 
    593             if (fi->second.contains(fi->first)) // Indent simple loops.
    594               outs() << '\t';
    595 
    596             IP->printInst(&Inst.Inst, outs(), "");
    597 
    598             // Look for relocations inside this instructions, if there is one
    599             // print its target and additional information if available.
    600             for (unsigned j = 0; j != Relocs.size(); ++j)
    601               if (Relocs[j].first >= SectAddress + Inst.Address &&
    602                   Relocs[j].first < SectAddress + Inst.Address + Inst.Size) {
    603                 StringRef SymName;
    604                 uint64_t Addr;
    605                 Relocs[j].second.getAddress(Addr);
    606                 Relocs[j].second.getName(SymName);
    607 
    608                 outs() << "\t# " << SymName << ' ';
    609                 DumpAddress(Addr, Sections, MachOObj, outs());
    610               }
    611 
    612             // If this instructions contains an address, see if we can evaluate
    613             // it and print additional information.
    614             uint64_t targ = InstrAnalysis->evaluateBranch(Inst.Inst,
    615                                                           Inst.Address,
    616                                                           Inst.Size);
    617             if (targ != -1ULL)
    618               DumpAddress(targ, Sections, MachOObj, outs());
    619 
    620             // Print debug info.
    621             if (diContext) {
    622               DILineInfo dli =
    623                 diContext->getLineInfoForAddress(SectAddress + Inst.Address);
    624               // Print valid line info if it changed.
    625               if (dli != lastLine && dli.getLine() != 0)
    626                 outs() << "\t## " << dli.getFileName() << ':'
    627                        << dli.getLine() << ':' << dli.getColumn();
    628               lastLine = dli;
    629             }
    630 
    631             outs() << '\n';
    632           }
    633         }
    634 
    635         emitDOTFile((f.getName().str() + ".dot").c_str(), f, IP.get());
    636       }
    637     }
    638   }
    639 }
    640