lib/DebugInfo/Symbolize/Symbolize.cpp

   1 //===-- LLVMSymbolize.cpp -------------------------------------------------===//
   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 // Implementation for LLVM symbolization library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/DebugInfo/Symbolize/Symbolize.h"
  15
  16 #include "SymbolizableObjectFile.h"
  17
  18 #include "llvm/ADT/STLExtras.h"
  19 #include "llvm/BinaryFormat/COFF.h"
  20 #include "llvm/Config/config.h"
  21 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
  22 #include "llvm/DebugInfo/PDB/PDB.h"
  23 #include "llvm/DebugInfo/PDB/PDBContext.h"
  24 #include "llvm/Demangle/Demangle.h"
  25 #include "llvm/Object/COFF.h"
  26 #include "llvm/Object/MachO.h"
  27 #include "llvm/Object/MachOUniversal.h"
  28 #include "llvm/Support/Casting.h"
  29 #include "llvm/Support/Compression.h"
  30 #include "llvm/Support/DataExtractor.h"
  31 #include "llvm/Support/Errc.h"
  32 #include "llvm/Support/FileSystem.h"
  33 #include "llvm/Support/MemoryBuffer.h"
  34 #include "llvm/Support/Path.h"
  35 #include <algorithm>
  36 #include <cassert>
  37 #include <cstdlib>
  38 #include <cstring>
  39
  40 #if defined(_MSC_VER)
  41 #include <Windows.h>
  42
  43 // This must be included after windows.h.
  44 #include <DbgHelp.h>
  45 #pragma comment(lib, "dbghelp.lib")
  46
  47 // Windows.h conflicts with our COFF header definitions.
  48 #ifdef IMAGE_FILE_MACHINE_I386
  49 #undef IMAGE_FILE_MACHINE_I386
  50 #endif
  51 #endif
  52
  53 namespace llvm {
  54 namespace symbolize {
  55
  56 Expected<DILineInfo>
  57 LLVMSymbolizer::symbolizeCode(const std::string &ModuleName,
  58                               uint64_t ModuleOffset, StringRef DWPName) {
  59   SymbolizableModule *Info;
  60   if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName, DWPName))
  61     Info = InfoOrErr.get();
  62   else
  63     return InfoOrErr.takeError();
  64
  65   // A null module means an error has already been reported. Return an empty
  66   // result.
  67   if (!Info)
  68     return DILineInfo();
  69
  70   // If the user is giving us relative addresses, add the preferred base of the
  71   // object to the offset before we do the query. It's what DIContext expects.
  72   if (Opts.RelativeAddresses)
  73     ModuleOffset += Info->getModulePreferredBase();
  74
  75   DILineInfo LineInfo = Info->symbolizeCode(ModuleOffset, Opts.PrintFunctions,
  76                                             Opts.UseSymbolTable);
  77   if (Opts.Demangle)
  78     LineInfo.FunctionName = DemangleName(LineInfo.FunctionName, Info);
  79   return LineInfo;
  80 }
  81
  82 Expected<DIInliningInfo>
  83 LLVMSymbolizer::symbolizeInlinedCode(const std::string &ModuleName,
  84                                      uint64_t ModuleOffset, StringRef DWPName) {
  85   SymbolizableModule *Info;
  86   if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName, DWPName))
  87     Info = InfoOrErr.get();
  88   else
  89     return InfoOrErr.takeError();
  90
  91   // A null module means an error has already been reported. Return an empty
  92   // result.
  93   if (!Info)
  94     return DIInliningInfo();
  95
  96   // If the user is giving us relative addresses, add the preferred base of the
  97   // object to the offset before we do the query. It's what DIContext expects.
  98   if (Opts.RelativeAddresses)
  99     ModuleOffset += Info->getModulePreferredBase();
 100
 101   DIInliningInfo InlinedContext = Info->symbolizeInlinedCode(
 102       ModuleOffset, Opts.PrintFunctions, Opts.UseSymbolTable);
 103   if (Opts.Demangle) {
 104     for (int i = 0, n = InlinedContext.getNumberOfFrames(); i < n; i++) {
 105       auto *Frame = InlinedContext.getMutableFrame(i);
 106       Frame->FunctionName = DemangleName(Frame->FunctionName, Info);
 107     }
 108   }
 109   return InlinedContext;
 110 }
 111
 112 Expected<DIGlobal> LLVMSymbolizer::symbolizeData(const std::string &ModuleName,
 113                                                  uint64_t ModuleOffset) {
 114   SymbolizableModule *Info;
 115   if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
 116     Info = InfoOrErr.get();
 117   else
 118     return InfoOrErr.takeError();
 119
 120   // A null module means an error has already been reported. Return an empty
 121   // result.
 122   if (!Info)
 123     return DIGlobal();
 124
 125   // If the user is giving us relative addresses, add the preferred base of
 126   // the object to the offset before we do the query. It's what DIContext
 127   // expects.
 128   if (Opts.RelativeAddresses)
 129     ModuleOffset += Info->getModulePreferredBase();
 130
 131   DIGlobal Global = Info->symbolizeData(ModuleOffset);
 132   if (Opts.Demangle)
 133     Global.Name = DemangleName(Global.Name, Info);
 134   return Global;
 135 }
 136
 137 void LLVMSymbolizer::flush() {
 138   ObjectForUBPathAndArch.clear();
 139   BinaryForPath.clear();
 140   ObjectPairForPathArch.clear();
 141   Modules.clear();
 142 }
 143
 144 namespace {
 145
 146 // For Path="/path/to/foo" and Basename="foo" assume that debug info is in
 147 // /path/to/foo.dSYM/Contents/Resources/DWARF/foo.
 148 // For Path="/path/to/bar.dSYM" and Basename="foo" assume that debug info is in
 149 // /path/to/bar.dSYM/Contents/Resources/DWARF/foo.
 150 std::string getDarwinDWARFResourceForPath(
 151     const std::string &Path, const std::string &Basename) {
 152   SmallString<16> ResourceName = StringRef(Path);
 153   if (sys::path::extension(Path) != ".dSYM") {
 154     ResourceName += ".dSYM";
 155   }
 156   sys::path::append(ResourceName, "Contents", "Resources", "DWARF");
 157   sys::path::append(ResourceName, Basename);
 158   return ResourceName.str();
 159 }
 160
 161 bool checkFileCRC(StringRef Path, uint32_t CRCHash) {
 162   ErrorOr<std::unique_ptr<MemoryBuffer>> MB =
 163       MemoryBuffer::getFileOrSTDIN(Path);
 164   if (!MB)
 165     return false;
 166   return !zlib::isAvailable() || CRCHash == zlib::crc32(MB.get()->getBuffer());
 167 }
 168
 169 bool findDebugBinary(const std::string &OrigPath,
 170                      const std::string &DebuglinkName, uint32_t CRCHash,
 171                      std::string &Result) {
 172   std::string OrigRealPath = OrigPath;
 173 #if defined(HAVE_REALPATH)
 174   if (char *RP = realpath(OrigPath.c_str(), nullptr)) {
 175     OrigRealPath = RP;
 176     free(RP);
 177   }
 178 #endif
 179   SmallString<16> OrigDir(OrigRealPath);
 180   llvm::sys::path::remove_filename(OrigDir);
 181   SmallString<16> DebugPath = OrigDir;
 182   // Try /path/to/original_binary/debuglink_name
 183   llvm::sys::path::append(DebugPath, DebuglinkName);
 184   if (checkFileCRC(DebugPath, CRCHash)) {
 185     Result = DebugPath.str();
 186     return true;
 187   }
 188   // Try /path/to/original_binary/.debug/debuglink_name
 189   DebugPath = OrigDir;
 190   llvm::sys::path::append(DebugPath, ".debug", DebuglinkName);
 191   if (checkFileCRC(DebugPath, CRCHash)) {
 192     Result = DebugPath.str();
 193     return true;
 194   }
 195 #if defined(__NetBSD__)
 196   // Try /usr/libdata/debug/path/to/original_binary/debuglink_name
 197   DebugPath = "/usr/libdata/debug";
 198 #else
 199   // Try /usr/lib/debug/path/to/original_binary/debuglink_name
 200   DebugPath = "/usr/lib/debug";
 201 #endif
 202   llvm::sys::path::append(DebugPath, llvm::sys::path::relative_path(OrigDir),
 203                           DebuglinkName);
 204   if (checkFileCRC(DebugPath, CRCHash)) {
 205     Result = DebugPath.str();
 206     return true;
 207   }
 208   return false;
 209 }
 210
 211 bool getGNUDebuglinkContents(const ObjectFile *Obj, std::string &DebugName,
 212                              uint32_t &CRCHash) {
 213   if (!Obj)
 214     return false;
 215   for (const SectionRef &Section : Obj->sections()) {
 216     StringRef Name;
 217     Section.getName(Name);
 218     Name = Name.substr(Name.find_first_not_of("._"));
 219     if (Name == "gnu_debuglink") {
 220       StringRef Data;
 221       Section.getContents(Data);
 222       DataExtractor DE(Data, Obj->isLittleEndian(), 0);
 223       uint32_t Offset = 0;
 224       if (const char *DebugNameStr = DE.getCStr(&Offset)) {
 225         // 4-byte align the offset.
 226         Offset = (Offset + 3) & ~0x3;
 227         if (DE.isValidOffsetForDataOfSize(Offset, 4)) {
 228           DebugName = DebugNameStr;
 229           CRCHash = DE.getU32(&Offset);
 230           return true;
 231         }
 232       }
 233       break;
 234     }
 235   }
 236   return false;
 237 }
 238
 239 bool darwinDsymMatchesBinary(const MachOObjectFile *DbgObj,
 240                              const MachOObjectFile *Obj) {
 241   ArrayRef<uint8_t> dbg_uuid = DbgObj->getUuid();
 242   ArrayRef<uint8_t> bin_uuid = Obj->getUuid();
 243   if (dbg_uuid.empty() || bin_uuid.empty())
 244     return false;
 245   return !memcmp(dbg_uuid.data(), bin_uuid.data(), dbg_uuid.size());
 246 }
 247
 248 } // end anonymous namespace
 249
 250 ObjectFile *LLVMSymbolizer::lookUpDsymFile(const std::string &ExePath,
 251     const MachOObjectFile *MachExeObj, const std::string &ArchName) {
 252   // On Darwin we may find DWARF in separate object file in
 253   // resource directory.
 254   std::vector<std::string> DsymPaths;
 255   StringRef Filename = sys::path::filename(ExePath);
 256   DsymPaths.push_back(getDarwinDWARFResourceForPath(ExePath, Filename));
 257   for (const auto &Path : Opts.DsymHints) {
 258     DsymPaths.push_back(getDarwinDWARFResourceForPath(Path, Filename));
 259   }
 260   for (const auto &Path : DsymPaths) {
 261     auto DbgObjOrErr = getOrCreateObject(Path, ArchName);
 262     if (!DbgObjOrErr) {
 263       // Ignore errors, the file might not exist.
 264       consumeError(DbgObjOrErr.takeError());
 265       continue;
 266     }
 267     ObjectFile *DbgObj = DbgObjOrErr.get();
 268     if (!DbgObj)
 269       continue;
 270     const MachOObjectFile *MachDbgObj = dyn_cast<const MachOObjectFile>(DbgObj);
 271     if (!MachDbgObj)
 272       continue;
 273     if (darwinDsymMatchesBinary(MachDbgObj, MachExeObj))
 274       return DbgObj;
 275   }
 276   return nullptr;
 277 }
 278
 279 ObjectFile *LLVMSymbolizer::lookUpDebuglinkObject(const std::string &Path,
 280                                                   const ObjectFile *Obj,
 281                                                   const std::string &ArchName) {
 282   std::string DebuglinkName;
 283   uint32_t CRCHash;
 284   std::string DebugBinaryPath;
 285   if (!getGNUDebuglinkContents(Obj, DebuglinkName, CRCHash))
 286     return nullptr;
 287   if (!findDebugBinary(Path, DebuglinkName, CRCHash, DebugBinaryPath))
 288     return nullptr;
 289   auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName);
 290   if (!DbgObjOrErr) {
 291     // Ignore errors, the file might not exist.
 292     consumeError(DbgObjOrErr.takeError());
 293     return nullptr;
 294   }
 295   return DbgObjOrErr.get();
 296 }
 297
 298 Expected<LLVMSymbolizer::ObjectPair>
 299 LLVMSymbolizer::getOrCreateObjectPair(const std::string &Path,
 300                                       const std::string &ArchName) {
 301   const auto &I = ObjectPairForPathArch.find(std::make_pair(Path, ArchName));
 302   if (I != ObjectPairForPathArch.end()) {
 303     return I->second;
 304   }
 305
 306   auto ObjOrErr = getOrCreateObject(Path, ArchName);
 307   if (!ObjOrErr) {
 308     ObjectPairForPathArch.insert(std::make_pair(std::make_pair(Path, ArchName),
 309                                                 ObjectPair(nullptr, nullptr)));
 310     return ObjOrErr.takeError();
 311   }
 312
 313   ObjectFile *Obj = ObjOrErr.get();
 314   assert(Obj != nullptr);
 315   ObjectFile *DbgObj = nullptr;
 316
 317   if (auto MachObj = dyn_cast<const MachOObjectFile>(Obj))
 318     DbgObj = lookUpDsymFile(Path, MachObj, ArchName);
 319   if (!DbgObj)
 320     DbgObj = lookUpDebuglinkObject(Path, Obj, ArchName);
 321   if (!DbgObj)
 322     DbgObj = Obj;
 323   ObjectPair Res = std::make_pair(Obj, DbgObj);
 324   ObjectPairForPathArch.insert(
 325       std::make_pair(std::make_pair(Path, ArchName), Res));
 326   return Res;
 327 }
 328
 329 Expected<ObjectFile *>
 330 LLVMSymbolizer::getOrCreateObject(const std::string &Path,
 331                                   const std::string &ArchName) {
 332   const auto &I = BinaryForPath.find(Path);
 333   Binary *Bin = nullptr;
 334   if (I == BinaryForPath.end()) {
 335     Expected<OwningBinary<Binary>> BinOrErr = createBinary(Path);
 336     if (!BinOrErr) {
 337       BinaryForPath.insert(std::make_pair(Path, OwningBinary<Binary>()));
 338       return BinOrErr.takeError();
 339     }
 340     Bin = BinOrErr->getBinary();
 341     BinaryForPath.insert(std::make_pair(Path, std::move(BinOrErr.get())));
 342   } else {
 343     Bin = I->second.getBinary();
 344   }
 345
 346   if (!Bin)
 347     return static_cast<ObjectFile *>(nullptr);
 348
 349   if (MachOUniversalBinary *UB = dyn_cast_or_null<MachOUniversalBinary>(Bin)) {
 350     const auto &I = ObjectForUBPathAndArch.find(std::make_pair(Path, ArchName));
 351     if (I != ObjectForUBPathAndArch.end()) {
 352       return I->second.get();
 353     }
 354     Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
 355         UB->getObjectForArch(ArchName);
 356     if (!ObjOrErr) {
 357       ObjectForUBPathAndArch.insert(std::make_pair(
 358           std::make_pair(Path, ArchName), std::unique_ptr<ObjectFile>()));
 359       return ObjOrErr.takeError();
 360     }
 361     ObjectFile *Res = ObjOrErr->get();
 362     ObjectForUBPathAndArch.insert(std::make_pair(std::make_pair(Path, ArchName),
 363                                                  std::move(ObjOrErr.get())));
 364     return Res;
 365   }
 366   if (Bin->isObject()) {
 367     return cast<ObjectFile>(Bin);
 368   }
 369   return errorCodeToError(object_error::arch_not_found);
 370 }
 371
 372 Expected<SymbolizableModule *>
 373 LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName,
 374                                       StringRef DWPName) {
 375   const auto &I = Modules.find(ModuleName);
 376   if (I != Modules.end()) {
 377     return I->second.get();
 378   }
 379   std::string BinaryName = ModuleName;
 380   std::string ArchName = Opts.DefaultArch;
 381   size_t ColonPos = ModuleName.find_last_of(':');
 382   // Verify that substring after colon form a valid arch name.
 383   if (ColonPos != std::string::npos) {
 384     std::string ArchStr = ModuleName.substr(ColonPos + 1);
 385     if (Triple(ArchStr).getArch() != Triple::UnknownArch) {
 386       BinaryName = ModuleName.substr(0, ColonPos);
 387       ArchName = ArchStr;
 388     }
 389   }
 390   auto ObjectsOrErr = getOrCreateObjectPair(BinaryName, ArchName);
 391   if (!ObjectsOrErr) {
 392     // Failed to find valid object file.
 393     Modules.insert(
 394         std::make_pair(ModuleName, std::unique_ptr<SymbolizableModule>()));
 395     return ObjectsOrErr.takeError();
 396   }
 397   ObjectPair Objects = ObjectsOrErr.get();
 398
 399   std::unique_ptr<DIContext> Context;
 400   // If this is a COFF object containing PDB info, use a PDBContext to
 401   // symbolize. Otherwise, use DWARF.
 402   if (auto CoffObject = dyn_cast<COFFObjectFile>(Objects.first)) {
 403     const codeview::DebugInfo *DebugInfo;
 404     StringRef PDBFileName;
 405     auto EC = CoffObject->getDebugPDBInfo(DebugInfo, PDBFileName);
 406     if (!EC && DebugInfo != nullptr && !PDBFileName.empty()) {
 407       using namespace pdb;
 408       std::unique_ptr<IPDBSession> Session;
 409       if (auto Err = loadDataForEXE(PDB_ReaderType::DIA,
 410                                     Objects.first->getFileName(), Session)) {
 411         Modules.insert(
 412             std::make_pair(ModuleName, std::unique_ptr<SymbolizableModule>()));
 413         // Return along the PDB filename to provide more context
 414         return createFileError(PDBFileName, std::move(Err));
 415       }
 416       Context.reset(new PDBContext(*CoffObject, std::move(Session)));
 417     }
 418   }
 419   if (!Context)
 420     Context = DWARFContext::create(*Objects.second, nullptr,
 421                                    DWARFContext::defaultErrorHandler, DWPName);
 422   assert(Context);
 423   auto InfoOrErr =
 424       SymbolizableObjectFile::create(Objects.first, std::move(Context));
 425   std::unique_ptr<SymbolizableModule> SymMod;
 426   if (InfoOrErr)
 427     SymMod = std::move(InfoOrErr.get());
 428   auto InsertResult =
 429       Modules.insert(std::make_pair(ModuleName, std::move(SymMod)));
 430   assert(InsertResult.second);
 431   if (auto EC = InfoOrErr.getError())
 432     return errorCodeToError(EC);
 433   return InsertResult.first->second.get();
 434 }
 435
 436 namespace {
 437
 438 // Undo these various manglings for Win32 extern "C" functions:
 439 // cdecl       - _foo
 440 // stdcall     - _foo@12
 441 // fastcall    - @foo@12
 442 // vectorcall  - foo@@12
 443 // These are all different linkage names for 'foo'.
 444 StringRef demanglePE32ExternCFunc(StringRef SymbolName) {
 445   // Remove any '_' or '@' prefix.
 446   char Front = SymbolName.empty() ? '\0' : SymbolName[0];
 447   if (Front == '_' || Front == '@')
 448     SymbolName = SymbolName.drop_front();
 449
 450   // Remove any '@[0-9]+' suffix.
 451   if (Front != '?') {
 452     size_t AtPos = SymbolName.rfind('@');
 453     if (AtPos != StringRef::npos &&
 454         std::all_of(SymbolName.begin() + AtPos + 1, SymbolName.end(),
 455                     [](char C) { return C >= '0' && C <= '9'; })) {
 456       SymbolName = SymbolName.substr(0, AtPos);
 457     }
 458   }
 459
 460   // Remove any ending '@' for vectorcall.
 461   if (SymbolName.endswith("@"))
 462     SymbolName = SymbolName.drop_back();
 463
 464   return SymbolName;
 465 }
 466
 467 } // end anonymous namespace
 468
 469 std::string
 470 LLVMSymbolizer::DemangleName(const std::string &Name,
 471                              const SymbolizableModule *DbiModuleDescriptor) {
 472   // We can spoil names of symbols with C linkage, so use an heuristic
 473   // approach to check if the name should be demangled.
 474   if (Name.substr(0, 2) == "_Z") {
 475     int status = 0;
 476     char *DemangledName = itaniumDemangle(Name.c_str(), nullptr, nullptr, &status);
 477     if (status != 0)
 478       return Name;
 479     std::string Result = DemangledName;
 480     free(DemangledName);
 481     return Result;
 482   }
 483
 484 #if defined(_MSC_VER)
 485   if (!Name.empty() && Name.front() == '?') {
 486     // Only do MSVC C++ demangling on symbols starting with '?'.
 487     char DemangledName[1024] = {0};
 488     DWORD result = ::UnDecorateSymbolName(
 489         Name.c_str(), DemangledName, 1023,
 490         UNDNAME_NO_ACCESS_SPECIFIERS |       // Strip public, private, protected
 491             UNDNAME_NO_ALLOCATION_LANGUAGE | // Strip __thiscall, __stdcall, etc
 492             UNDNAME_NO_THROW_SIGNATURES |    // Strip throw() specifications
 493             UNDNAME_NO_MEMBER_TYPE | // Strip virtual, static, etc specifiers
 494             UNDNAME_NO_MS_KEYWORDS | // Strip all MS extension keywords
 495             UNDNAME_NO_FUNCTION_RETURNS); // Strip function return types
 496     return (result == 0) ? Name : std::string(DemangledName);
 497   }
 498 #endif
 499   if (DbiModuleDescriptor && DbiModuleDescriptor->isWin32Module())
 500     return std::string(demanglePE32ExternCFunc(Name));
 501   return Name;
 502 }
 503
 504 } // namespace symbolize
 505 } // namespace llvm