Symbolize.cpp revision 360784 
1//===-- LLVMSymbolize.cpp -------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Implementation for LLVM symbolization library.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/DebugInfo/Symbolize/Symbolize.h"
14
15#include "SymbolizableObjectFile.h"
16
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/BinaryFormat/COFF.h"
19#include "llvm/DebugInfo/DWARF/DWARFContext.h"
20#include "llvm/DebugInfo/PDB/PDB.h"
21#include "llvm/DebugInfo/PDB/PDBContext.h"
22#include "llvm/Demangle/Demangle.h"
23#include "llvm/Object/COFF.h"
24#include "llvm/Object/MachO.h"
25#include "llvm/Object/MachOUniversal.h"
26#include "llvm/Support/CRC.h"
27#include "llvm/Support/Casting.h"
28#include "llvm/Support/Compression.h"
29#include "llvm/Support/DataExtractor.h"
30#include "llvm/Support/Errc.h"
31#include "llvm/Support/FileSystem.h"
32#include "llvm/Support/MemoryBuffer.h"
33#include "llvm/Support/Path.h"
34#include <algorithm>
35#include <cassert>
36#include <cstring>
37
38namespace llvm {
39namespace symbolize {
40
41Expected<DILineInfo>
42LLVMSymbolizer::symbolizeCodeCommon(SymbolizableModule *Info,
43                                    object::SectionedAddress ModuleOffset) {
44  // A null module means an error has already been reported. Return an empty
45  // result.
46  if (!Info)
47    return DILineInfo();
48
49  // If the user is giving us relative addresses, add the preferred base of the
50  // object to the offset before we do the query. It's what DIContext expects.
51  if (Opts.RelativeAddresses)
52    ModuleOffset.Address += Info->getModulePreferredBase();
53
54  DILineInfo LineInfo = Info->symbolizeCode(ModuleOffset, Opts.PrintFunctions,
55                                            Opts.UseSymbolTable);
56  if (Opts.Demangle)
57    LineInfo.FunctionName = DemangleName(LineInfo.FunctionName, Info);
58  return LineInfo;
59}
60
61Expected<DILineInfo>
62LLVMSymbolizer::symbolizeCode(const ObjectFile &Obj,
63                              object::SectionedAddress ModuleOffset) {
64  StringRef ModuleName = Obj.getFileName();
65  auto I = Modules.find(ModuleName);
66  if (I != Modules.end())
67    return symbolizeCodeCommon(I->second.get(), ModuleOffset);
68
69  std::unique_ptr<DIContext> Context =
70        DWARFContext::create(Obj, nullptr, DWARFContext::defaultErrorHandler);
71  Expected<SymbolizableModule *> InfoOrErr =
72                     createModuleInfo(&Obj, std::move(Context), ModuleName);
73  if (!InfoOrErr)
74    return InfoOrErr.takeError();
75  return symbolizeCodeCommon(*InfoOrErr, ModuleOffset);
76}
77
78Expected<DILineInfo>
79LLVMSymbolizer::symbolizeCode(const std::string &ModuleName,
80                              object::SectionedAddress ModuleOffset) {
81  Expected<SymbolizableModule *> InfoOrErr = getOrCreateModuleInfo(ModuleName);
82  if (!InfoOrErr)
83    return InfoOrErr.takeError();
84  return symbolizeCodeCommon(*InfoOrErr, ModuleOffset);
85}
86
87Expected<DIInliningInfo>
88LLVMSymbolizer::symbolizeInlinedCode(const std::string &ModuleName,
89                                     object::SectionedAddress ModuleOffset) {
90  SymbolizableModule *Info;
91  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
92    Info = InfoOrErr.get();
93  else
94    return InfoOrErr.takeError();
95
96  // A null module means an error has already been reported. Return an empty
97  // result.
98  if (!Info)
99    return DIInliningInfo();
100
101  // If the user is giving us relative addresses, add the preferred base of the
102  // object to the offset before we do the query. It's what DIContext expects.
103  if (Opts.RelativeAddresses)
104    ModuleOffset.Address += Info->getModulePreferredBase();
105
106  DIInliningInfo InlinedContext = Info->symbolizeInlinedCode(
107      ModuleOffset, Opts.PrintFunctions, Opts.UseSymbolTable);
108  if (Opts.Demangle) {
109    for (int i = 0, n = InlinedContext.getNumberOfFrames(); i < n; i++) {
110      auto *Frame = InlinedContext.getMutableFrame(i);
111      Frame->FunctionName = DemangleName(Frame->FunctionName, Info);
112    }
113  }
114  return InlinedContext;
115}
116
117Expected<DIGlobal>
118LLVMSymbolizer::symbolizeData(const std::string &ModuleName,
119                              object::SectionedAddress ModuleOffset) {
120  SymbolizableModule *Info;
121  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
122    Info = InfoOrErr.get();
123  else
124    return InfoOrErr.takeError();
125
126  // A null module means an error has already been reported. Return an empty
127  // result.
128  if (!Info)
129    return DIGlobal();
130
131  // If the user is giving us relative addresses, add the preferred base of
132  // the object to the offset before we do the query. It's what DIContext
133  // expects.
134  if (Opts.RelativeAddresses)
135    ModuleOffset.Address += Info->getModulePreferredBase();
136
137  DIGlobal Global = Info->symbolizeData(ModuleOffset);
138  if (Opts.Demangle)
139    Global.Name = DemangleName(Global.Name, Info);
140  return Global;
141}
142
143Expected<std::vector<DILocal>>
144LLVMSymbolizer::symbolizeFrame(const std::string &ModuleName,
145                               object::SectionedAddress ModuleOffset) {
146  SymbolizableModule *Info;
147  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
148    Info = InfoOrErr.get();
149  else
150    return InfoOrErr.takeError();
151
152  // A null module means an error has already been reported. Return an empty
153  // result.
154  if (!Info)
155    return std::vector<DILocal>();
156
157  // If the user is giving us relative addresses, add the preferred base of
158  // the object to the offset before we do the query. It's what DIContext
159  // expects.
160  if (Opts.RelativeAddresses)
161    ModuleOffset.Address += Info->getModulePreferredBase();
162
163  return Info->symbolizeFrame(ModuleOffset);
164}
165
166void LLVMSymbolizer::flush() {
167  ObjectForUBPathAndArch.clear();
168  BinaryForPath.clear();
169  ObjectPairForPathArch.clear();
170  Modules.clear();
171}
172
173namespace {
174
175// For Path="/path/to/foo" and Basename="foo" assume that debug info is in
176// /path/to/foo.dSYM/Contents/Resources/DWARF/foo.
177// For Path="/path/to/bar.dSYM" and Basename="foo" assume that debug info is in
178// /path/to/bar.dSYM/Contents/Resources/DWARF/foo.
179std::string getDarwinDWARFResourceForPath(
180    const std::string &Path, const std::string &Basename) {
181  SmallString<16> ResourceName = StringRef(Path);
182  if (sys::path::extension(Path) != ".dSYM") {
183    ResourceName += ".dSYM";
184  }
185  sys::path::append(ResourceName, "Contents", "Resources", "DWARF");
186  sys::path::append(ResourceName, Basename);
187  return ResourceName.str();
188}
189
190bool checkFileCRC(StringRef Path, uint32_t CRCHash) {
191  ErrorOr<std::unique_ptr<MemoryBuffer>> MB =
192      MemoryBuffer::getFileOrSTDIN(Path);
193  if (!MB)
194    return false;
195  return CRCHash == llvm::crc32(arrayRefFromStringRef(MB.get()->getBuffer()));
196}
197
198bool findDebugBinary(const std::string &OrigPath,
199                     const std::string &DebuglinkName, uint32_t CRCHash,
200                     const std::string &FallbackDebugPath,
201                     std::string &Result) {
202  SmallString<16> OrigDir(OrigPath);
203  llvm::sys::path::remove_filename(OrigDir);
204  SmallString<16> DebugPath = OrigDir;
205  // Try relative/path/to/original_binary/debuglink_name
206  llvm::sys::path::append(DebugPath, DebuglinkName);
207  if (checkFileCRC(DebugPath, CRCHash)) {
208    Result = DebugPath.str();
209    return true;
210  }
211  // Try relative/path/to/original_binary/.debug/debuglink_name
212  DebugPath = OrigDir;
213  llvm::sys::path::append(DebugPath, ".debug", DebuglinkName);
214  if (checkFileCRC(DebugPath, CRCHash)) {
215    Result = DebugPath.str();
216    return true;
217  }
218  // Make the path absolute so that lookups will go to
219  // "/usr/lib/debug/full/path/to/debug", not
220  // "/usr/lib/debug/to/debug"
221  llvm::sys::fs::make_absolute(OrigDir);
222  if (!FallbackDebugPath.empty()) {
223    // Try <FallbackDebugPath>/absolute/path/to/original_binary/debuglink_name
224    DebugPath = FallbackDebugPath;
225  } else {
226#if defined(__NetBSD__)
227    // Try /usr/libdata/debug/absolute/path/to/original_binary/debuglink_name
228    DebugPath = "/usr/libdata/debug";
229#else
230    // Try /usr/lib/debug/absolute/path/to/original_binary/debuglink_name
231    DebugPath = "/usr/lib/debug";
232#endif
233  }
234  llvm::sys::path::append(DebugPath, llvm::sys::path::relative_path(OrigDir),
235                          DebuglinkName);
236  if (checkFileCRC(DebugPath, CRCHash)) {
237    Result = DebugPath.str();
238    return true;
239  }
240  return false;
241}
242
243bool getGNUDebuglinkContents(const ObjectFile *Obj, std::string &DebugName,
244                             uint32_t &CRCHash) {
245  if (!Obj)
246    return false;
247  for (const SectionRef &Section : Obj->sections()) {
248    StringRef Name;
249    if (Expected<StringRef> NameOrErr = Section.getName())
250      Name = *NameOrErr;
251    else
252      consumeError(NameOrErr.takeError());
253
254    Name = Name.substr(Name.find_first_not_of("._"));
255    if (Name == "gnu_debuglink") {
256      Expected<StringRef> ContentsOrErr = Section.getContents();
257      if (!ContentsOrErr) {
258        consumeError(ContentsOrErr.takeError());
259        return false;
260      }
261      DataExtractor DE(*ContentsOrErr, Obj->isLittleEndian(), 0);
262      uint64_t Offset = 0;
263      if (const char *DebugNameStr = DE.getCStr(&Offset)) {
264        // 4-byte align the offset.
265        Offset = (Offset + 3) & ~0x3;
266        if (DE.isValidOffsetForDataOfSize(Offset, 4)) {
267          DebugName = DebugNameStr;
268          CRCHash = DE.getU32(&Offset);
269          return true;
270        }
271      }
272      break;
273    }
274  }
275  return false;
276}
277
278bool darwinDsymMatchesBinary(const MachOObjectFile *DbgObj,
279                             const MachOObjectFile *Obj) {
280  ArrayRef<uint8_t> dbg_uuid = DbgObj->getUuid();
281  ArrayRef<uint8_t> bin_uuid = Obj->getUuid();
282  if (dbg_uuid.empty() || bin_uuid.empty())
283    return false;
284  return !memcmp(dbg_uuid.data(), bin_uuid.data(), dbg_uuid.size());
285}
286
287template <typename ELFT>
288Optional<ArrayRef<uint8_t>> getBuildID(const ELFFile<ELFT> *Obj) {
289  if (!Obj)
290    return {};
291  auto PhdrsOrErr = Obj->program_headers();
292  if (!PhdrsOrErr) {
293    consumeError(PhdrsOrErr.takeError());
294    return {};
295  }
296  for (const auto &P : *PhdrsOrErr) {
297    if (P.p_type != ELF::PT_NOTE)
298      continue;
299    Error Err = Error::success();
300    for (auto N : Obj->notes(P, Err))
301      if (N.getType() == ELF::NT_GNU_BUILD_ID && N.getName() == ELF::ELF_NOTE_GNU)
302        return N.getDesc();
303  }
304  return {};
305}
306
307Optional<ArrayRef<uint8_t>> getBuildID(const ELFObjectFileBase *Obj) {
308  Optional<ArrayRef<uint8_t>> BuildID;
309  if (auto *O = dyn_cast<ELFObjectFile<ELF32LE>>(Obj))
310    BuildID = getBuildID(O->getELFFile());
311  else if (auto *O = dyn_cast<ELFObjectFile<ELF32BE>>(Obj))
312    BuildID = getBuildID(O->getELFFile());
313  else if (auto *O = dyn_cast<ELFObjectFile<ELF64LE>>(Obj))
314    BuildID = getBuildID(O->getELFFile());
315  else if (auto *O = dyn_cast<ELFObjectFile<ELF64BE>>(Obj))
316    BuildID = getBuildID(O->getELFFile());
317  else
318    llvm_unreachable("unsupported file format");
319  return BuildID;
320}
321
322bool findDebugBinary(const std::vector<std::string> &DebugFileDirectory,
323                     const ArrayRef<uint8_t> BuildID,
324                     std::string &Result) {
325  auto getDebugPath = [&](StringRef Directory) {
326    SmallString<128> Path{Directory};
327    sys::path::append(Path, ".build-id",
328                      llvm::toHex(BuildID[0], /*LowerCase=*/true),
329                      llvm::toHex(BuildID.slice(1), /*LowerCase=*/true));
330    Path += ".debug";
331    return Path;
332  };
333  if (DebugFileDirectory.empty()) {
334    SmallString<128> Path = getDebugPath(
335#if defined(__NetBSD__)
336      // Try /usr/libdata/debug/.build-id/../...
337      "/usr/libdata/debug"
338#else
339      // Try /usr/lib/debug/.build-id/../...
340      "/usr/lib/debug"
341#endif
342    );
343    if (llvm::sys::fs::exists(Path)) {
344      Result = Path.str();
345      return true;
346    }
347  } else {
348    for (const auto &Directory : DebugFileDirectory) {
349      // Try <debug-file-directory>/.build-id/../...
350      SmallString<128> Path = getDebugPath(Directory);
351      if (llvm::sys::fs::exists(Path)) {
352        Result = Path.str();
353        return true;
354      }
355    }
356  }
357  return false;
358}
359
360} // end anonymous namespace
361
362ObjectFile *LLVMSymbolizer::lookUpDsymFile(const std::string &ExePath,
363    const MachOObjectFile *MachExeObj, const std::string &ArchName) {
364  // On Darwin we may find DWARF in separate object file in
365  // resource directory.
366  std::vector<std::string> DsymPaths;
367  StringRef Filename = sys::path::filename(ExePath);
368  DsymPaths.push_back(getDarwinDWARFResourceForPath(ExePath, Filename));
369  for (const auto &Path : Opts.DsymHints) {
370    DsymPaths.push_back(getDarwinDWARFResourceForPath(Path, Filename));
371  }
372  for (const auto &Path : DsymPaths) {
373    auto DbgObjOrErr = getOrCreateObject(Path, ArchName);
374    if (!DbgObjOrErr) {
375      // Ignore errors, the file might not exist.
376      consumeError(DbgObjOrErr.takeError());
377      continue;
378    }
379    ObjectFile *DbgObj = DbgObjOrErr.get();
380    if (!DbgObj)
381      continue;
382    const MachOObjectFile *MachDbgObj = dyn_cast<const MachOObjectFile>(DbgObj);
383    if (!MachDbgObj)
384      continue;
385    if (darwinDsymMatchesBinary(MachDbgObj, MachExeObj))
386      return DbgObj;
387  }
388  return nullptr;
389}
390
391ObjectFile *LLVMSymbolizer::lookUpDebuglinkObject(const std::string &Path,
392                                                  const ObjectFile *Obj,
393                                                  const std::string &ArchName) {
394  std::string DebuglinkName;
395  uint32_t CRCHash;
396  std::string DebugBinaryPath;
397  if (!getGNUDebuglinkContents(Obj, DebuglinkName, CRCHash))
398    return nullptr;
399  if (!findDebugBinary(Path, DebuglinkName, CRCHash, Opts.FallbackDebugPath,
400                       DebugBinaryPath))
401    return nullptr;
402  auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName);
403  if (!DbgObjOrErr) {
404    // Ignore errors, the file might not exist.
405    consumeError(DbgObjOrErr.takeError());
406    return nullptr;
407  }
408  return DbgObjOrErr.get();
409}
410
411ObjectFile *LLVMSymbolizer::lookUpBuildIDObject(const std::string &Path,
412                                                const ELFObjectFileBase *Obj,
413                                                const std::string &ArchName) {
414  auto BuildID = getBuildID(Obj);
415  if (!BuildID)
416    return nullptr;
417  if (BuildID->size() < 2)
418    return nullptr;
419  std::string DebugBinaryPath;
420  if (!findDebugBinary(Opts.DebugFileDirectory, *BuildID, DebugBinaryPath))
421    return nullptr;
422  auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName);
423  if (!DbgObjOrErr) {
424    consumeError(DbgObjOrErr.takeError());
425    return nullptr;
426  }
427  return DbgObjOrErr.get();
428}
429
430Expected<LLVMSymbolizer::ObjectPair>
431LLVMSymbolizer::getOrCreateObjectPair(const std::string &Path,
432                                      const std::string &ArchName) {
433  auto I = ObjectPairForPathArch.find(std::make_pair(Path, ArchName));
434  if (I != ObjectPairForPathArch.end())
435    return I->second;
436
437  auto ObjOrErr = getOrCreateObject(Path, ArchName);
438  if (!ObjOrErr) {
439    ObjectPairForPathArch.emplace(std::make_pair(Path, ArchName),
440                                  ObjectPair(nullptr, nullptr));
441    return ObjOrErr.takeError();
442  }
443
444  ObjectFile *Obj = ObjOrErr.get();
445  assert(Obj != nullptr);
446  ObjectFile *DbgObj = nullptr;
447
448  if (auto MachObj = dyn_cast<const MachOObjectFile>(Obj))
449    DbgObj = lookUpDsymFile(Path, MachObj, ArchName);
450  else if (auto ELFObj = dyn_cast<const ELFObjectFileBase>(Obj))
451    DbgObj = lookUpBuildIDObject(Path, ELFObj, ArchName);
452  if (!DbgObj)
453    DbgObj = lookUpDebuglinkObject(Path, Obj, ArchName);
454  if (!DbgObj)
455    DbgObj = Obj;
456  ObjectPair Res = std::make_pair(Obj, DbgObj);
457  ObjectPairForPathArch.emplace(std::make_pair(Path, ArchName), Res);
458  return Res;
459}
460
461Expected<ObjectFile *>
462LLVMSymbolizer::getOrCreateObject(const std::string &Path,
463                                  const std::string &ArchName) {
464  Binary *Bin;
465  auto Pair = BinaryForPath.emplace(Path, OwningBinary<Binary>());
466  if (!Pair.second) {
467    Bin = Pair.first->second.getBinary();
468  } else {
469    Expected<OwningBinary<Binary>> BinOrErr = createBinary(Path);
470    if (!BinOrErr)
471      return BinOrErr.takeError();
472    Pair.first->second = std::move(BinOrErr.get());
473    Bin = Pair.first->second.getBinary();
474  }
475
476  if (!Bin)
477    return static_cast<ObjectFile *>(nullptr);
478
479  if (MachOUniversalBinary *UB = dyn_cast_or_null<MachOUniversalBinary>(Bin)) {
480    auto I = ObjectForUBPathAndArch.find(std::make_pair(Path, ArchName));
481    if (I != ObjectForUBPathAndArch.end())
482      return I->second.get();
483
484    Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
485        UB->getMachOObjectForArch(ArchName);
486    if (!ObjOrErr) {
487      ObjectForUBPathAndArch.emplace(std::make_pair(Path, ArchName),
488                                     std::unique_ptr<ObjectFile>());
489      return ObjOrErr.takeError();
490    }
491    ObjectFile *Res = ObjOrErr->get();
492    ObjectForUBPathAndArch.emplace(std::make_pair(Path, ArchName),
493                                   std::move(ObjOrErr.get()));
494    return Res;
495  }
496  if (Bin->isObject()) {
497    return cast<ObjectFile>(Bin);
498  }
499  return errorCodeToError(object_error::arch_not_found);
500}
501
502Expected<SymbolizableModule *>
503LLVMSymbolizer::createModuleInfo(const ObjectFile *Obj,
504                                 std::unique_ptr<DIContext> Context,
505                                 StringRef ModuleName) {
506  auto InfoOrErr = SymbolizableObjectFile::create(Obj, std::move(Context),
507                                                  Opts.UntagAddresses);
508  std::unique_ptr<SymbolizableModule> SymMod;
509  if (InfoOrErr)
510    SymMod = std::move(*InfoOrErr);
511  auto InsertResult =
512      Modules.insert(std::make_pair(ModuleName, std::move(SymMod)));
513  assert(InsertResult.second);
514  if (std::error_code EC = InfoOrErr.getError())
515    return errorCodeToError(EC);
516  return InsertResult.first->second.get();
517}
518
519Expected<SymbolizableModule *>
520LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
521  auto I = Modules.find(ModuleName);
522  if (I != Modules.end())
523    return I->second.get();
524
525  std::string BinaryName = ModuleName;
526  std::string ArchName = Opts.DefaultArch;
527  size_t ColonPos = ModuleName.find_last_of(':');
528  // Verify that substring after colon form a valid arch name.
529  if (ColonPos != std::string::npos) {
530    std::string ArchStr = ModuleName.substr(ColonPos + 1);
531    if (Triple(ArchStr).getArch() != Triple::UnknownArch) {
532      BinaryName = ModuleName.substr(0, ColonPos);
533      ArchName = ArchStr;
534    }
535  }
536  auto ObjectsOrErr = getOrCreateObjectPair(BinaryName, ArchName);
537  if (!ObjectsOrErr) {
538    // Failed to find valid object file.
539    Modules.emplace(ModuleName, std::unique_ptr<SymbolizableModule>());
540    return ObjectsOrErr.takeError();
541  }
542  ObjectPair Objects = ObjectsOrErr.get();
543
544  std::unique_ptr<DIContext> Context;
545  // If this is a COFF object containing PDB info, use a PDBContext to
546  // symbolize. Otherwise, use DWARF.
547  if (auto CoffObject = dyn_cast<COFFObjectFile>(Objects.first)) {
548    const codeview::DebugInfo *DebugInfo;
549    StringRef PDBFileName;
550    auto EC = CoffObject->getDebugPDBInfo(DebugInfo, PDBFileName);
551    if (!EC && DebugInfo != nullptr && !PDBFileName.empty()) {
552#if 0
553      using namespace pdb;
554      std::unique_ptr<IPDBSession> Session;
555      if (auto Err = loadDataForEXE(PDB_ReaderType::DIA,
556                                    Objects.first->getFileName(), Session)) {
557        Modules.emplace(ModuleName, std::unique_ptr<SymbolizableModule>());
558        // Return along the PDB filename to provide more context
559        return createFileError(PDBFileName, std::move(Err));
560      }
561      Context.reset(new PDBContext(*CoffObject, std::move(Session)));
562#else
563      return make_error<StringError>(
564          "PDB support not compiled in",
565          std::make_error_code(std::errc::not_supported));
566#endif
567    }
568  }
569  if (!Context)
570    Context =
571        DWARFContext::create(*Objects.second, nullptr,
572                             DWARFContext::defaultErrorHandler, Opts.DWPName);
573  return createModuleInfo(Objects.first, std::move(Context), ModuleName);
574}
575
576namespace {
577
578// Undo these various manglings for Win32 extern "C" functions:
579// cdecl       - _foo
580// stdcall     - _foo@12
581// fastcall    - @foo@12
582// vectorcall  - foo@@12
583// These are all different linkage names for 'foo'.
584StringRef demanglePE32ExternCFunc(StringRef SymbolName) {
585  // Remove any '_' or '@' prefix.
586  char Front = SymbolName.empty() ? '\0' : SymbolName[0];
587  if (Front == '_' || Front == '@')
588    SymbolName = SymbolName.drop_front();
589
590  // Remove any '@[0-9]+' suffix.
591  if (Front != '?') {
592    size_t AtPos = SymbolName.rfind('@');
593    if (AtPos != StringRef::npos &&
594        std::all_of(SymbolName.begin() + AtPos + 1, SymbolName.end(),
595                    [](char C) { return C >= '0' && C <= '9'; })) {
596      SymbolName = SymbolName.substr(0, AtPos);
597    }
598  }
599
600  // Remove any ending '@' for vectorcall.
601  if (SymbolName.endswith("@"))
602    SymbolName = SymbolName.drop_back();
603
604  return SymbolName;
605}
606
607} // end anonymous namespace
608
609std::string
610LLVMSymbolizer::DemangleName(const std::string &Name,
611                             const SymbolizableModule *DbiModuleDescriptor) {
612  // We can spoil names of symbols with C linkage, so use an heuristic
613  // approach to check if the name should be demangled.
614  if (Name.substr(0, 2) == "_Z") {
615    int status = 0;
616    char *DemangledName = itaniumDemangle(Name.c_str(), nullptr, nullptr, &status);
617    if (status != 0)
618      return Name;
619    std::string Result = DemangledName;
620    free(DemangledName);
621    return Result;
622  }
623
624  if (!Name.empty() && Name.front() == '?') {
625    // Only do MSVC C++ demangling on symbols starting with '?'.
626    int status = 0;
627    char *DemangledName = microsoftDemangle(
628        Name.c_str(), nullptr, nullptr, &status,
629        MSDemangleFlags(MSDF_NoAccessSpecifier | MSDF_NoCallingConvention |
630                        MSDF_NoMemberType | MSDF_NoReturnType));
631    if (status != 0)
632      return Name;
633    std::string Result = DemangledName;
634    free(DemangledName);
635    return Result;
636  }
637
638  if (DbiModuleDescriptor && DbiModuleDescriptor->isWin32Module())
639    return std::string(demanglePE32ExternCFunc(Name));
640  return Name;
641}
642
643} // namespace symbolize
644} // namespace llvm
645