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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/Archive.h"
     21 #include "llvm/Bitcode/ReaderWriter.h"
     22 #include "llvm/IR/Module.h"
     23 #include "llvm/Object/Archive.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   std::string ToolName;
    125 }
    126 
    127 
    128 static void error(Twine message, Twine path = Twine()) {
    129   errs() << ToolName << ": " << path << ": " << message << ".\n";
    130 }
    131 
    132 static bool error(error_code ec, Twine path = Twine()) {
    133   if (ec) {
    134     error(ec.message(), path);
    135     return true;
    136   }
    137   return false;
    138 }
    139 
    140 namespace {
    141   struct NMSymbol {
    142     uint64_t  Address;
    143     uint64_t  Size;
    144     char      TypeChar;
    145     StringRef Name;
    146   };
    147 
    148   static bool CompareSymbolAddress(const NMSymbol &a, const NMSymbol &b) {
    149     if (a.Address < b.Address)
    150       return true;
    151     else if (a.Address == b.Address && a.Name < b.Name)
    152       return true;
    153     else if (a.Address == b.Address && a.Name == b.Name && a.Size < b.Size)
    154       return true;
    155     else
    156       return false;
    157 
    158   }
    159 
    160   static bool CompareSymbolSize(const NMSymbol &a, const NMSymbol &b) {
    161     if (a.Size < b.Size)
    162       return true;
    163     else if (a.Size == b.Size && a.Name < b.Name)
    164       return true;
    165     else if (a.Size == b.Size && a.Name == b.Name && a.Address < b.Address)
    166       return true;
    167     else
    168       return false;
    169   }
    170 
    171   static bool CompareSymbolName(const NMSymbol &a, const NMSymbol &b) {
    172     if (a.Name < b.Name)
    173       return true;
    174     else if (a.Name == b.Name && a.Size < b.Size)
    175       return true;
    176     else if (a.Name == b.Name && a.Size == b.Size && a.Address < b.Address)
    177       return true;
    178     else
    179       return false;
    180   }
    181 
    182   StringRef CurrentFilename;
    183   typedef std::vector<NMSymbol> SymbolListT;
    184   SymbolListT SymbolList;
    185 }
    186 
    187 static void SortAndPrintSymbolList() {
    188   if (!NoSort) {
    189     if (NumericSort)
    190       std::sort(SymbolList.begin(), SymbolList.end(), CompareSymbolAddress);
    191     else if (SizeSort)
    192       std::sort(SymbolList.begin(), SymbolList.end(), CompareSymbolSize);
    193     else
    194       std::sort(SymbolList.begin(), SymbolList.end(), CompareSymbolName);
    195   }
    196 
    197   if (OutputFormat == posix && MultipleFiles) {
    198     outs() << '\n' << CurrentFilename << ":\n";
    199   } else if (OutputFormat == bsd && MultipleFiles) {
    200     outs() << "\n" << CurrentFilename << ":\n";
    201   } else if (OutputFormat == sysv) {
    202     outs() << "\n\nSymbols from " << CurrentFilename << ":\n\n"
    203            << "Name                  Value   Class        Type"
    204            << "         Size   Line  Section\n";
    205   }
    206 
    207   for (SymbolListT::iterator i = SymbolList.begin(),
    208                              e = SymbolList.end(); i != e; ++i) {
    209     if ((i->TypeChar != 'U') && UndefinedOnly)
    210       continue;
    211     if ((i->TypeChar == 'U') && DefinedOnly)
    212       continue;
    213     if (SizeSort && !PrintAddress && i->Size == UnknownAddressOrSize)
    214       continue;
    215 
    216     char SymbolAddrStr[10] = "";
    217     char SymbolSizeStr[10] = "";
    218 
    219     if (OutputFormat == sysv || i->Address == object::UnknownAddressOrSize)
    220       strcpy(SymbolAddrStr, "        ");
    221     if (OutputFormat == sysv)
    222       strcpy(SymbolSizeStr, "        ");
    223 
    224     if (i->Address != object::UnknownAddressOrSize)
    225       format("%08" PRIx64, i->Address).print(SymbolAddrStr,
    226                                              sizeof(SymbolAddrStr));
    227     if (i->Size != object::UnknownAddressOrSize)
    228       format("%08" PRIx64, i->Size).print(SymbolSizeStr, sizeof(SymbolSizeStr));
    229 
    230     if (OutputFormat == posix) {
    231       outs() << i->Name << " " << i->TypeChar << " "
    232              << SymbolAddrStr << SymbolSizeStr << "\n";
    233     } else if (OutputFormat == bsd) {
    234       if (PrintAddress)
    235         outs() << SymbolAddrStr << ' ';
    236       if (PrintSize) {
    237         outs() << SymbolSizeStr;
    238         if (i->Size != object::UnknownAddressOrSize)
    239           outs() << ' ';
    240       }
    241       outs() << i->TypeChar << " " << i->Name  << "\n";
    242     } else if (OutputFormat == sysv) {
    243       std::string PaddedName (i->Name);
    244       while (PaddedName.length () < 20)
    245         PaddedName += " ";
    246       outs() << PaddedName << "|" << SymbolAddrStr << "|   "
    247              << i->TypeChar
    248              << "  |                  |" << SymbolSizeStr << "|     |\n";
    249     }
    250   }
    251 
    252   SymbolList.clear();
    253 }
    254 
    255 static char TypeCharForSymbol(GlobalValue &GV) {
    256   if (GV.isDeclaration())                                  return 'U';
    257   if (GV.hasLinkOnceLinkage())                             return 'C';
    258   if (GV.hasCommonLinkage())                               return 'C';
    259   if (GV.hasWeakLinkage())                                 return 'W';
    260   if (isa<Function>(GV) && GV.hasInternalLinkage())        return 't';
    261   if (isa<Function>(GV))                                   return 'T';
    262   if (isa<GlobalVariable>(GV) && GV.hasInternalLinkage())  return 'd';
    263   if (isa<GlobalVariable>(GV))                             return 'D';
    264   if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(&GV)) {
    265     const GlobalValue *AliasedGV = GA->getAliasedGlobal();
    266     if (isa<Function>(AliasedGV))                          return 'T';
    267     if (isa<GlobalVariable>(AliasedGV))                    return 'D';
    268   }
    269                                                            return '?';
    270 }
    271 
    272 static void DumpSymbolNameForGlobalValue(GlobalValue &GV) {
    273   // Private linkage and available_externally linkage don't exist in symtab.
    274   if (GV.hasPrivateLinkage() ||
    275       GV.hasLinkerPrivateLinkage() ||
    276       GV.hasLinkerPrivateWeakLinkage() ||
    277       GV.hasAvailableExternallyLinkage())
    278     return;
    279   char TypeChar = TypeCharForSymbol(GV);
    280   if (GV.hasLocalLinkage () && ExternalOnly)
    281     return;
    282 
    283   NMSymbol s;
    284   s.Address = object::UnknownAddressOrSize;
    285   s.Size = object::UnknownAddressOrSize;
    286   s.TypeChar = TypeChar;
    287   s.Name     = GV.getName();
    288   SymbolList.push_back(s);
    289 }
    290 
    291 static void DumpSymbolNamesFromModule(Module *M) {
    292   CurrentFilename = M->getModuleIdentifier();
    293   std::for_each (M->begin(), M->end(), DumpSymbolNameForGlobalValue);
    294   std::for_each (M->global_begin(), M->global_end(),
    295                  DumpSymbolNameForGlobalValue);
    296   if (!WithoutAliases)
    297     std::for_each (M->alias_begin(), M->alias_end(),
    298 		   DumpSymbolNameForGlobalValue);
    299 
    300   SortAndPrintSymbolList();
    301 }
    302 
    303 static void DumpSymbolNamesFromObject(ObjectFile *obj) {
    304   error_code ec;
    305   symbol_iterator ibegin = obj->begin_symbols();
    306   symbol_iterator iend = obj->end_symbols();
    307   if (DynamicSyms) {
    308     ibegin = obj->begin_dynamic_symbols();
    309     iend = obj->end_dynamic_symbols();
    310   }
    311   for (symbol_iterator i = ibegin; i != iend; i.increment(ec)) {
    312     if (error(ec)) break;
    313     uint32_t symflags;
    314     if (error(i->getFlags(symflags))) break;
    315     if (!DebugSyms && (symflags & SymbolRef::SF_FormatSpecific))
    316       continue;
    317     NMSymbol s;
    318     s.Size = object::UnknownAddressOrSize;
    319     s.Address = object::UnknownAddressOrSize;
    320     if (PrintSize || SizeSort) {
    321       if (error(i->getSize(s.Size))) break;
    322     }
    323     if (PrintAddress)
    324       if (error(i->getAddress(s.Address))) break;
    325     if (error(i->getNMTypeChar(s.TypeChar))) break;
    326     if (error(i->getName(s.Name))) break;
    327     SymbolList.push_back(s);
    328   }
    329 
    330   CurrentFilename = obj->getFileName();
    331   SortAndPrintSymbolList();
    332 }
    333 
    334 static void DumpSymbolNamesFromFile(std::string &Filename) {
    335   if (Filename != "-" && !sys::fs::exists(Filename)) {
    336     errs() << ToolName << ": '" << Filename << "': " << "No such file\n";
    337     return;
    338   }
    339 
    340   OwningPtr<MemoryBuffer> Buffer;
    341   if (error(MemoryBuffer::getFileOrSTDIN(Filename, Buffer), Filename))
    342     return;
    343 
    344   sys::fs::file_magic magic = sys::fs::identify_magic(Buffer->getBuffer());
    345 
    346   LLVMContext &Context = getGlobalContext();
    347   std::string ErrorMessage;
    348   if (magic == sys::fs::file_magic::bitcode) {
    349     Module *Result = 0;
    350     Result = ParseBitcodeFile(Buffer.get(), Context, &ErrorMessage);
    351     if (Result) {
    352       DumpSymbolNamesFromModule(Result);
    353       delete Result;
    354     } else {
    355       error(ErrorMessage, Filename);
    356       return;
    357     }
    358   } else if (magic == sys::fs::file_magic::archive) {
    359     OwningPtr<Binary> arch;
    360     if (error(object::createBinary(Buffer.take(), arch), Filename))
    361       return;
    362 
    363     if (object::Archive *a = dyn_cast<object::Archive>(arch.get())) {
    364       if (ArchiveMap) {
    365         outs() << "Archive map" << "\n";
    366         for (object::Archive::symbol_iterator i = a->begin_symbols(),
    367              e = a->end_symbols(); i != e; ++i) {
    368           object::Archive::child_iterator c;
    369           StringRef symname;
    370           StringRef filename;
    371           if (error(i->getMember(c)))
    372               return;
    373           if (error(i->getName(symname)))
    374               return;
    375           if (error(c->getName(filename)))
    376               return;
    377           outs() << symname << " in " << filename << "\n";
    378         }
    379         outs() << "\n";
    380       }
    381 
    382       for (object::Archive::child_iterator i = a->begin_children(),
    383                                            e = a->end_children(); i != e; ++i) {
    384         OwningPtr<Binary> child;
    385         if (i->getAsBinary(child)) {
    386           // Try opening it as a bitcode file.
    387           OwningPtr<MemoryBuffer> buff;
    388           if (error(i->getMemoryBuffer(buff)))
    389             return;
    390           Module *Result = 0;
    391           if (buff)
    392             Result = ParseBitcodeFile(buff.get(), Context, &ErrorMessage);
    393 
    394           if (Result) {
    395             DumpSymbolNamesFromModule(Result);
    396             delete Result;
    397           }
    398           continue;
    399         }
    400         if (object::ObjectFile *o = dyn_cast<ObjectFile>(child.get())) {
    401           outs() << o->getFileName() << ":\n";
    402           DumpSymbolNamesFromObject(o);
    403         }
    404       }
    405     }
    406   } else if (magic.is_object()) {
    407     OwningPtr<Binary> obj;
    408     if (error(object::createBinary(Buffer.take(), obj), Filename))
    409       return;
    410     if (object::ObjectFile *o = dyn_cast<ObjectFile>(obj.get()))
    411       DumpSymbolNamesFromObject(o);
    412   } else {
    413     errs() << ToolName << ": " << Filename << ": "
    414            << "unrecognizable file type\n";
    415     return;
    416   }
    417 }
    418 
    419 int main(int argc, char **argv) {
    420   // Print a stack trace if we signal out.
    421   sys::PrintStackTraceOnErrorSignal();
    422   PrettyStackTraceProgram X(argc, argv);
    423 
    424   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
    425   cl::ParseCommandLineOptions(argc, argv, "llvm symbol table dumper\n");
    426 
    427   // llvm-nm only reads binary files.
    428   if (error(sys::Program::ChangeStdinToBinary()))
    429     return 1;
    430 
    431   ToolName = argv[0];
    432   if (BSDFormat) OutputFormat = bsd;
    433   if (POSIXFormat) OutputFormat = posix;
    434 
    435   // The relative order of these is important. If you pass --size-sort it should
    436   // only print out the size. However, if you pass -S --size-sort, it should
    437   // print out both the size and address.
    438   if (SizeSort && !PrintSize) PrintAddress = false;
    439   if (OutputFormat == sysv || SizeSort) PrintSize = true;
    440 
    441   switch (InputFilenames.size()) {
    442   case 0: InputFilenames.push_back("-");
    443   case 1: break;
    444   default: MultipleFiles = true;
    445   }
    446 
    447   std::for_each(InputFilenames.begin(), InputFilenames.end(),
    448                 DumpSymbolNamesFromFile);
    449   return 0;
    450 }
    451