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      1 //===-- llvm-nm.cpp - Symbol table 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 program is a utility that works like traditional Unix "nm", that is, it
     11 // prints out the names of symbols in a bitcode or object file, along with some
     12 // information about each symbol.
     13 //
     14 // This "nm" supports many of the features of GNU "nm", including its different
     15 // output formats.
     16 //
     17 //===----------------------------------------------------------------------===//
     18 
     19 #include "llvm/IR/LLVMContext.h"
     20 #include "llvm/Bitcode/ReaderWriter.h"
     21 #include "llvm/IR/Module.h"
     22 #include "llvm/Object/Archive.h"
     23 #include "llvm/Object/MachOUniversal.h"
     24 #include "llvm/Object/ObjectFile.h"
     25 #include "llvm/Support/CommandLine.h"
     26 #include "llvm/Support/FileSystem.h"
     27 #include "llvm/Support/Format.h"
     28 #include "llvm/Support/ManagedStatic.h"
     29 #include "llvm/Support/MemoryBuffer.h"
     30 #include "llvm/Support/PrettyStackTrace.h"
     31 #include "llvm/Support/Program.h"
     32 #include "llvm/Support/Signals.h"
     33 #include "llvm/Support/raw_ostream.h"
     34 #include "llvm/Support/system_error.h"
     35 #include <algorithm>
     36 #include <cctype>
     37 #include <cerrno>
     38 #include <cstring>
     39 #include <vector>
     40 using namespace llvm;
     41 using namespace object;
     42 
     43 namespace {
     44   enum OutputFormatTy { bsd, sysv, posix };
     45   cl::opt<OutputFormatTy>
     46   OutputFormat("format",
     47        cl::desc("Specify output format"),
     48          cl::values(clEnumVal(bsd,   "BSD format"),
     49                     clEnumVal(sysv,  "System V format"),
     50                     clEnumVal(posix, "POSIX.2 format"),
     51                     clEnumValEnd), cl::init(bsd));
     52   cl::alias OutputFormat2("f", cl::desc("Alias for --format"),
     53                           cl::aliasopt(OutputFormat));
     54 
     55   cl::list<std::string>
     56   InputFilenames(cl::Positional, cl::desc("<input bitcode files>"),
     57                  cl::ZeroOrMore);
     58 
     59   cl::opt<bool> UndefinedOnly("undefined-only",
     60                               cl::desc("Show only undefined symbols"));
     61   cl::alias UndefinedOnly2("u", cl::desc("Alias for --undefined-only"),
     62                            cl::aliasopt(UndefinedOnly));
     63 
     64   cl::opt<bool> DynamicSyms("dynamic",
     65                              cl::desc("Display the dynamic symbols instead "
     66                                       "of normal symbols."));
     67   cl::alias DynamicSyms2("D", cl::desc("Alias for --dynamic"),
     68                          cl::aliasopt(DynamicSyms));
     69 
     70   cl::opt<bool> DefinedOnly("defined-only",
     71                             cl::desc("Show only defined symbols"));
     72 
     73   cl::opt<bool> ExternalOnly("extern-only",
     74                              cl::desc("Show only external symbols"));
     75   cl::alias ExternalOnly2("g", cl::desc("Alias for --extern-only"),
     76                           cl::aliasopt(ExternalOnly));
     77 
     78   cl::opt<bool> BSDFormat("B", cl::desc("Alias for --format=bsd"));
     79   cl::opt<bool> POSIXFormat("P", cl::desc("Alias for --format=posix"));
     80 
     81   cl::opt<bool> PrintFileName("print-file-name",
     82     cl::desc("Precede each symbol with the object file it came from"));
     83 
     84   cl::alias PrintFileNameA("A", cl::desc("Alias for --print-file-name"),
     85                                 cl::aliasopt(PrintFileName));
     86   cl::alias PrintFileNameo("o", cl::desc("Alias for --print-file-name"),
     87                                 cl::aliasopt(PrintFileName));
     88 
     89   cl::opt<bool> DebugSyms("debug-syms",
     90     cl::desc("Show all symbols, even debugger only"));
     91   cl::alias DebugSymsa("a", cl::desc("Alias for --debug-syms"),
     92                             cl::aliasopt(DebugSyms));
     93 
     94   cl::opt<bool> NumericSort("numeric-sort",
     95     cl::desc("Sort symbols by address"));
     96   cl::alias NumericSortn("n", cl::desc("Alias for --numeric-sort"),
     97                               cl::aliasopt(NumericSort));
     98   cl::alias NumericSortv("v", cl::desc("Alias for --numeric-sort"),
     99                               cl::aliasopt(NumericSort));
    100 
    101   cl::opt<bool> NoSort("no-sort",
    102     cl::desc("Show symbols in order encountered"));
    103   cl::alias NoSortp("p", cl::desc("Alias for --no-sort"),
    104                          cl::aliasopt(NoSort));
    105 
    106   cl::opt<bool> PrintSize("print-size",
    107     cl::desc("Show symbol size instead of address"));
    108   cl::alias PrintSizeS("S", cl::desc("Alias for --print-size"),
    109                             cl::aliasopt(PrintSize));
    110 
    111   cl::opt<bool> SizeSort("size-sort", cl::desc("Sort symbols by size"));
    112 
    113   cl::opt<bool> WithoutAliases("without-aliases", cl::Hidden,
    114                                cl::desc("Exclude aliases from output"));
    115 
    116   cl::opt<bool> ArchiveMap("print-armap",
    117     cl::desc("Print the archive map"));
    118   cl::alias ArchiveMaps("s", cl::desc("Alias for --print-armap"),
    119                                  cl::aliasopt(ArchiveMap));
    120   bool PrintAddress = true;
    121 
    122   bool MultipleFiles = false;
    123 
    124   bool HadError = false;
    125 
    126   std::string ToolName;
    127 }
    128 
    129 
    130 static void error(Twine message, Twine path = Twine()) {
    131   errs() << ToolName << ": " << path << ": " << message << ".\n";
    132 }
    133 
    134 static bool error(error_code ec, Twine path = Twine()) {
    135   if (ec) {
    136     error(ec.message(), path);
    137     HadError = true;
    138     return true;
    139   }
    140   return false;
    141 }
    142 
    143 namespace {
    144   struct NMSymbol {
    145     uint64_t  Address;
    146     uint64_t  Size;
    147     char      TypeChar;
    148     StringRef Name;
    149   };
    150 
    151   static bool CompareSymbolAddress(const NMSymbol &a, const NMSymbol &b) {
    152     if (a.Address < b.Address)
    153       return true;
    154     else if (a.Address == b.Address && a.Name < b.Name)
    155       return true;
    156     else if (a.Address == b.Address && a.Name == b.Name && a.Size < b.Size)
    157       return true;
    158     else
    159       return false;
    160 
    161   }
    162 
    163   static bool CompareSymbolSize(const NMSymbol &a, const NMSymbol &b) {
    164     if (a.Size < b.Size)
    165       return true;
    166     else if (a.Size == b.Size && a.Name < b.Name)
    167       return true;
    168     else if (a.Size == b.Size && a.Name == b.Name && a.Address < b.Address)
    169       return true;
    170     else
    171       return false;
    172   }
    173 
    174   static bool CompareSymbolName(const NMSymbol &a, const NMSymbol &b) {
    175     if (a.Name < b.Name)
    176       return true;
    177     else if (a.Name == b.Name && a.Size < b.Size)
    178       return true;
    179     else if (a.Name == b.Name && a.Size == b.Size && a.Address < b.Address)
    180       return true;
    181     else
    182       return false;
    183   }
    184 
    185   StringRef CurrentFilename;
    186   typedef std::vector<NMSymbol> SymbolListT;
    187   SymbolListT SymbolList;
    188 }
    189 
    190 static void SortAndPrintSymbolList() {
    191   if (!NoSort) {
    192     if (NumericSort)
    193       std::sort(SymbolList.begin(), SymbolList.end(), CompareSymbolAddress);
    194     else if (SizeSort)
    195       std::sort(SymbolList.begin(), SymbolList.end(), CompareSymbolSize);
    196     else
    197       std::sort(SymbolList.begin(), SymbolList.end(), CompareSymbolName);
    198   }
    199 
    200   if (OutputFormat == posix && MultipleFiles) {
    201     outs() << '\n' << CurrentFilename << ":\n";
    202   } else if (OutputFormat == bsd && MultipleFiles) {
    203     outs() << "\n" << CurrentFilename << ":\n";
    204   } else if (OutputFormat == sysv) {
    205     outs() << "\n\nSymbols from " << CurrentFilename << ":\n\n"
    206            << "Name                  Value   Class        Type"
    207            << "         Size   Line  Section\n";
    208   }
    209 
    210   for (SymbolListT::iterator i = SymbolList.begin(),
    211                              e = SymbolList.end(); i != e; ++i) {
    212     if ((i->TypeChar != 'U') && UndefinedOnly)
    213       continue;
    214     if ((i->TypeChar == 'U') && DefinedOnly)
    215       continue;
    216     if (SizeSort && !PrintAddress && i->Size == UnknownAddressOrSize)
    217       continue;
    218 
    219     char SymbolAddrStr[10] = "";
    220     char SymbolSizeStr[10] = "";
    221 
    222     if (OutputFormat == sysv || i->Address == object::UnknownAddressOrSize)
    223       strcpy(SymbolAddrStr, "        ");
    224     if (OutputFormat == sysv)
    225       strcpy(SymbolSizeStr, "        ");
    226 
    227     if (i->Address != object::UnknownAddressOrSize)
    228       format("%08" PRIx64, i->Address).print(SymbolAddrStr,
    229                                              sizeof(SymbolAddrStr));
    230     if (i->Size != object::UnknownAddressOrSize)
    231       format("%08" PRIx64, i->Size).print(SymbolSizeStr, sizeof(SymbolSizeStr));
    232 
    233     if (OutputFormat == posix) {
    234       outs() << i->Name << " " << i->TypeChar << " "
    235              << SymbolAddrStr << SymbolSizeStr << "\n";
    236     } else if (OutputFormat == bsd) {
    237       if (PrintAddress)
    238         outs() << SymbolAddrStr << ' ';
    239       if (PrintSize) {
    240         outs() << SymbolSizeStr;
    241         if (i->Size != object::UnknownAddressOrSize)
    242           outs() << ' ';
    243       }
    244       outs() << i->TypeChar << " " << i->Name  << "\n";
    245     } else if (OutputFormat == sysv) {
    246       std::string PaddedName (i->Name);
    247       while (PaddedName.length () < 20)
    248         PaddedName += " ";
    249       outs() << PaddedName << "|" << SymbolAddrStr << "|   "
    250              << i->TypeChar
    251              << "  |                  |" << SymbolSizeStr << "|     |\n";
    252     }
    253   }
    254 
    255   SymbolList.clear();
    256 }
    257 
    258 static char TypeCharForSymbol(GlobalValue &GV) {
    259   if (GV.isDeclaration())                                  return 'U';
    260   if (GV.hasLinkOnceLinkage())                             return 'C';
    261   if (GV.hasCommonLinkage())                               return 'C';
    262   if (GV.hasWeakLinkage())                                 return 'W';
    263   if (isa<Function>(GV) && GV.hasInternalLinkage())        return 't';
    264   if (isa<Function>(GV))                                   return 'T';
    265   if (isa<GlobalVariable>(GV) && GV.hasInternalLinkage())  return 'd';
    266   if (isa<GlobalVariable>(GV))                             return 'D';
    267   if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(&GV)) {
    268     const GlobalValue *AliasedGV = GA->getAliasedGlobal();
    269     if (isa<Function>(AliasedGV))                          return 'T';
    270     if (isa<GlobalVariable>(AliasedGV))                    return 'D';
    271   }
    272                                                            return '?';
    273 }
    274 
    275 static void DumpSymbolNameForGlobalValue(GlobalValue &GV) {
    276   // Private linkage and available_externally linkage don't exist in symtab.
    277   if (GV.hasPrivateLinkage() ||
    278       GV.hasLinkerPrivateLinkage() ||
    279       GV.hasLinkerPrivateWeakLinkage() ||
    280       GV.hasAvailableExternallyLinkage())
    281     return;
    282   char TypeChar = TypeCharForSymbol(GV);
    283   if (GV.hasLocalLinkage () && ExternalOnly)
    284     return;
    285 
    286   NMSymbol s;
    287   s.Address = object::UnknownAddressOrSize;
    288   s.Size = object::UnknownAddressOrSize;
    289   s.TypeChar = TypeChar;
    290   s.Name     = GV.getName();
    291   SymbolList.push_back(s);
    292 }
    293 
    294 static void DumpSymbolNamesFromModule(Module *M) {
    295   CurrentFilename = M->getModuleIdentifier();
    296   std::for_each (M->begin(), M->end(), DumpSymbolNameForGlobalValue);
    297   std::for_each (M->global_begin(), M->global_end(),
    298                  DumpSymbolNameForGlobalValue);
    299   if (!WithoutAliases)
    300     std::for_each (M->alias_begin(), M->alias_end(),
    301 		   DumpSymbolNameForGlobalValue);
    302 
    303   SortAndPrintSymbolList();
    304 }
    305 
    306 static void DumpSymbolNamesFromObject(ObjectFile *obj) {
    307   error_code ec;
    308   symbol_iterator ibegin = obj->begin_symbols();
    309   symbol_iterator iend = obj->end_symbols();
    310   if (DynamicSyms) {
    311     ibegin = obj->begin_dynamic_symbols();
    312     iend = obj->end_dynamic_symbols();
    313   }
    314   for (symbol_iterator i = ibegin; i != iend; i.increment(ec)) {
    315     if (error(ec)) break;
    316     uint32_t symflags;
    317     if (error(i->getFlags(symflags))) break;
    318     if (!DebugSyms && (symflags & SymbolRef::SF_FormatSpecific))
    319       continue;
    320     NMSymbol s;
    321     s.Size = object::UnknownAddressOrSize;
    322     s.Address = object::UnknownAddressOrSize;
    323     if (PrintSize || SizeSort) {
    324       if (error(i->getSize(s.Size))) break;
    325     }
    326     if (PrintAddress)
    327       if (error(i->getAddress(s.Address))) break;
    328     if (error(i->getNMTypeChar(s.TypeChar))) break;
    329     if (error(i->getName(s.Name))) break;
    330     SymbolList.push_back(s);
    331   }
    332 
    333   CurrentFilename = obj->getFileName();
    334   SortAndPrintSymbolList();
    335 }
    336 
    337 static void DumpSymbolNamesFromFile(std::string &Filename) {
    338   if (Filename != "-" && !sys::fs::exists(Filename)) {
    339     errs() << ToolName << ": '" << Filename << "': " << "No such file\n";
    340     return;
    341   }
    342 
    343   OwningPtr<MemoryBuffer> Buffer;
    344   if (error(MemoryBuffer::getFileOrSTDIN(Filename, Buffer), Filename))
    345     return;
    346 
    347   sys::fs::file_magic magic = sys::fs::identify_magic(Buffer->getBuffer());
    348 
    349   LLVMContext &Context = getGlobalContext();
    350   std::string ErrorMessage;
    351   if (magic == sys::fs::file_magic::bitcode) {
    352     Module *Result = 0;
    353     Result = ParseBitcodeFile(Buffer.get(), Context, &ErrorMessage);
    354     if (Result) {
    355       DumpSymbolNamesFromModule(Result);
    356       delete Result;
    357     } else {
    358       error(ErrorMessage, Filename);
    359       return;
    360     }
    361   } else if (magic == sys::fs::file_magic::archive) {
    362     OwningPtr<Binary> arch;
    363     if (error(object::createBinary(Buffer.take(), arch), Filename))
    364       return;
    365 
    366     if (object::Archive *a = dyn_cast<object::Archive>(arch.get())) {
    367       if (ArchiveMap) {
    368         object::Archive::symbol_iterator I = a->begin_symbols();
    369         object::Archive::symbol_iterator E = a->end_symbols();
    370         if (I !=E) {
    371           outs() << "Archive map" << "\n";
    372           for (; I != E; ++I) {
    373             object::Archive::child_iterator c;
    374             StringRef symname;
    375             StringRef filename;
    376             if (error(I->getMember(c)))
    377               return;
    378             if (error(I->getName(symname)))
    379               return;
    380             if (error(c->getName(filename)))
    381               return;
    382             outs() << symname << " in " << filename << "\n";
    383           }
    384           outs() << "\n";
    385         }
    386       }
    387 
    388       for (object::Archive::child_iterator i = a->begin_children(),
    389                                            e = a->end_children(); i != e; ++i) {
    390         OwningPtr<Binary> child;
    391         if (i->getAsBinary(child)) {
    392           // Try opening it as a bitcode file.
    393           OwningPtr<MemoryBuffer> buff;
    394           if (error(i->getMemoryBuffer(buff)))
    395             return;
    396           Module *Result = 0;
    397           if (buff)
    398             Result = ParseBitcodeFile(buff.get(), Context, &ErrorMessage);
    399 
    400           if (Result) {
    401             DumpSymbolNamesFromModule(Result);
    402             delete Result;
    403           }
    404           continue;
    405         }
    406         if (object::ObjectFile *o = dyn_cast<ObjectFile>(child.get())) {
    407           outs() << o->getFileName() << ":\n";
    408           DumpSymbolNamesFromObject(o);
    409         }
    410       }
    411     }
    412   } else if (magic == sys::fs::file_magic::macho_universal_binary) {
    413     OwningPtr<Binary> Bin;
    414     if (error(object::createBinary(Buffer.take(), Bin), Filename))
    415       return;
    416 
    417     object::MachOUniversalBinary *UB =
    418         cast<object::MachOUniversalBinary>(Bin.get());
    419     for (object::MachOUniversalBinary::object_iterator
    420              I = UB->begin_objects(),
    421              E = UB->end_objects();
    422          I != E; ++I) {
    423       OwningPtr<ObjectFile> Obj;
    424       if (!I->getAsObjectFile(Obj)) {
    425         outs() << Obj->getFileName() << ":\n";
    426         DumpSymbolNamesFromObject(Obj.get());
    427       }
    428     }
    429   } else if (magic.is_object()) {
    430     OwningPtr<Binary> obj;
    431     if (error(object::createBinary(Buffer.take(), obj), Filename))
    432       return;
    433     if (object::ObjectFile *o = dyn_cast<ObjectFile>(obj.get()))
    434       DumpSymbolNamesFromObject(o);
    435   } else {
    436     errs() << ToolName << ": " << Filename << ": "
    437            << "unrecognizable file type\n";
    438     HadError = true;
    439     return;
    440   }
    441 }
    442 
    443 int main(int argc, char **argv) {
    444   // Print a stack trace if we signal out.
    445   sys::PrintStackTraceOnErrorSignal();
    446   PrettyStackTraceProgram X(argc, argv);
    447 
    448   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
    449   cl::ParseCommandLineOptions(argc, argv, "llvm symbol table dumper\n");
    450 
    451   // llvm-nm only reads binary files.
    452   if (error(sys::ChangeStdinToBinary()))
    453     return 1;
    454 
    455   ToolName = argv[0];
    456   if (BSDFormat) OutputFormat = bsd;
    457   if (POSIXFormat) OutputFormat = posix;
    458 
    459   // The relative order of these is important. If you pass --size-sort it should
    460   // only print out the size. However, if you pass -S --size-sort, it should
    461   // print out both the size and address.
    462   if (SizeSort && !PrintSize) PrintAddress = false;
    463   if (OutputFormat == sysv || SizeSort) PrintSize = true;
    464 
    465   switch (InputFilenames.size()) {
    466   case 0: InputFilenames.push_back("-");
    467   case 1: break;
    468   default: MultipleFiles = true;
    469   }
    470 
    471   std::for_each(InputFilenames.begin(), InputFilenames.end(),
    472                 DumpSymbolNamesFromFile);
    473 
    474   if (HadError)
    475     return 1;
    476 
    477   return 0;
    478 }
    479