LLVM  4.0.0
Symbolize.cpp
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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 
15 
16 #include "SymbolizableObjectFile.h"
17 
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/Config/config.h"
21 #include "llvm/DebugInfo/PDB/PDB.h"
23 #include "llvm/Object/COFF.h"
25 #include "llvm/Object/MachO.h"
27 #include "llvm/Support/COFF.h"
28 #include "llvm/Support/Casting.h"
31 #include "llvm/Support/Errc.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 #include <DbgHelp.h>
43 #pragma comment(lib, "dbghelp.lib")
44 
45 // Windows.h conflicts with our COFF header definitions.
46 #ifdef IMAGE_FILE_MACHINE_I386
47 #undef IMAGE_FILE_MACHINE_I386
48 #endif
49 #endif
50 
51 namespace llvm {
52 namespace symbolize {
53 
55  uint64_t ModuleOffset) {
56  SymbolizableModule *Info;
57  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
58  Info = InfoOrErr.get();
59  else
60  return InfoOrErr.takeError();
61 
62  // A null module means an error has already been reported. Return an empty
63  // result.
64  if (!Info)
65  return DILineInfo();
66 
67  // If the user is giving us relative addresses, add the preferred base of the
68  // object to the offset before we do the query. It's what DIContext expects.
69  if (Opts.RelativeAddresses)
70  ModuleOffset += Info->getModulePreferredBase();
71 
72  DILineInfo LineInfo = Info->symbolizeCode(ModuleOffset, Opts.PrintFunctions,
73  Opts.UseSymbolTable);
74  if (Opts.Demangle)
75  LineInfo.FunctionName = DemangleName(LineInfo.FunctionName, Info);
76  return LineInfo;
77 }
78 
80 LLVMSymbolizer::symbolizeInlinedCode(const std::string &ModuleName,
81  uint64_t ModuleOffset) {
82  SymbolizableModule *Info;
83  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
84  Info = InfoOrErr.get();
85  else
86  return InfoOrErr.takeError();
87 
88  // A null module means an error has already been reported. Return an empty
89  // result.
90  if (!Info)
91  return DIInliningInfo();
92 
93  // If the user is giving us relative addresses, add the preferred base of the
94  // object to the offset before we do the query. It's what DIContext expects.
95  if (Opts.RelativeAddresses)
96  ModuleOffset += Info->getModulePreferredBase();
97 
98  DIInliningInfo InlinedContext = Info->symbolizeInlinedCode(
99  ModuleOffset, Opts.PrintFunctions, Opts.UseSymbolTable);
100  if (Opts.Demangle) {
101  for (int i = 0, n = InlinedContext.getNumberOfFrames(); i < n; i++) {
102  auto *Frame = InlinedContext.getMutableFrame(i);
103  Frame->FunctionName = DemangleName(Frame->FunctionName, Info);
104  }
105  }
106  return InlinedContext;
107 }
108 
109 Expected<DIGlobal> LLVMSymbolizer::symbolizeData(const std::string &ModuleName,
110  uint64_t ModuleOffset) {
111  SymbolizableModule *Info;
112  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
113  Info = InfoOrErr.get();
114  else
115  return InfoOrErr.takeError();
116 
117  // A null module means an error has already been reported. Return an empty
118  // result.
119  if (!Info)
120  return DIGlobal();
121 
122  // If the user is giving us relative addresses, add the preferred base of
123  // the object to the offset before we do the query. It's what DIContext
124  // expects.
125  if (Opts.RelativeAddresses)
126  ModuleOffset += Info->getModulePreferredBase();
127 
128  DIGlobal Global = Info->symbolizeData(ModuleOffset);
129  if (Opts.Demangle)
130  Global.Name = DemangleName(Global.Name, Info);
131  return Global;
132 }
133 
135  ObjectForUBPathAndArch.clear();
136  BinaryForPath.clear();
137  ObjectPairForPathArch.clear();
138  Modules.clear();
139 }
140 
141 namespace {
142 
143 // For Path="/path/to/foo" and Basename="foo" assume that debug info is in
144 // /path/to/foo.dSYM/Contents/Resources/DWARF/foo.
145 // For Path="/path/to/bar.dSYM" and Basename="foo" assume that debug info is in
146 // /path/to/bar.dSYM/Contents/Resources/DWARF/foo.
147 std::string getDarwinDWARFResourceForPath(
148  const std::string &Path, const std::string &Basename) {
149  SmallString<16> ResourceName = StringRef(Path);
150  if (sys::path::extension(Path) != ".dSYM") {
151  ResourceName += ".dSYM";
152  }
153  sys::path::append(ResourceName, "Contents", "Resources", "DWARF");
154  sys::path::append(ResourceName, Basename);
155  return ResourceName.str();
156 }
157 
158 bool checkFileCRC(StringRef Path, uint32_t CRCHash) {
159  ErrorOr<std::unique_ptr<MemoryBuffer>> MB =
161  if (!MB)
162  return false;
163  return !zlib::isAvailable() || CRCHash == zlib::crc32(MB.get()->getBuffer());
164 }
165 
166 bool findDebugBinary(const std::string &OrigPath,
167  const std::string &DebuglinkName, uint32_t CRCHash,
168  std::string &Result) {
169  std::string OrigRealPath = OrigPath;
170 #if defined(HAVE_REALPATH)
171  if (char *RP = realpath(OrigPath.c_str(), nullptr)) {
172  OrigRealPath = RP;
173  free(RP);
174  }
175 #endif
176  SmallString<16> OrigDir(OrigRealPath);
178  SmallString<16> DebugPath = OrigDir;
179  // Try /path/to/original_binary/debuglink_name
180  llvm::sys::path::append(DebugPath, DebuglinkName);
181  if (checkFileCRC(DebugPath, CRCHash)) {
182  Result = DebugPath.str();
183  return true;
184  }
185  // Try /path/to/original_binary/.debug/debuglink_name
186  DebugPath = OrigRealPath;
187  llvm::sys::path::append(DebugPath, ".debug", DebuglinkName);
188  if (checkFileCRC(DebugPath, CRCHash)) {
189  Result = DebugPath.str();
190  return true;
191  }
192  // Try /usr/lib/debug/path/to/original_binary/debuglink_name
193  DebugPath = "/usr/lib/debug";
195  DebuglinkName);
196  if (checkFileCRC(DebugPath, CRCHash)) {
197  Result = DebugPath.str();
198  return true;
199  }
200  return false;
201 }
202 
203 bool getGNUDebuglinkContents(const ObjectFile *Obj, std::string &DebugName,
204  uint32_t &CRCHash) {
205  if (!Obj)
206  return false;
207  for (const SectionRef &Section : Obj->sections()) {
208  StringRef Name;
209  Section.getName(Name);
210  Name = Name.substr(Name.find_first_not_of("._"));
211  if (Name == "gnu_debuglink") {
212  StringRef Data;
213  Section.getContents(Data);
214  DataExtractor DE(Data, Obj->isLittleEndian(), 0);
215  uint32_t Offset = 0;
216  if (const char *DebugNameStr = DE.getCStr(&Offset)) {
217  // 4-byte align the offset.
218  Offset = (Offset + 3) & ~0x3;
219  if (DE.isValidOffsetForDataOfSize(Offset, 4)) {
220  DebugName = DebugNameStr;
221  CRCHash = DE.getU32(&Offset);
222  return true;
223  }
224  }
225  break;
226  }
227  }
228  return false;
229 }
230 
231 bool darwinDsymMatchesBinary(const MachOObjectFile *DbgObj,
232  const MachOObjectFile *Obj) {
233  ArrayRef<uint8_t> dbg_uuid = DbgObj->getUuid();
234  ArrayRef<uint8_t> bin_uuid = Obj->getUuid();
235  if (dbg_uuid.empty() || bin_uuid.empty())
236  return false;
237  return !memcmp(dbg_uuid.data(), bin_uuid.data(), dbg_uuid.size());
238 }
239 
240 } // end anonymous namespace
241 
242 ObjectFile *LLVMSymbolizer::lookUpDsymFile(const std::string &ExePath,
243  const MachOObjectFile *MachExeObj, const std::string &ArchName) {
244  // On Darwin we may find DWARF in separate object file in
245  // resource directory.
246  std::vector<std::string> DsymPaths;
247  StringRef Filename = sys::path::filename(ExePath);
248  DsymPaths.push_back(getDarwinDWARFResourceForPath(ExePath, Filename));
249  for (const auto &Path : Opts.DsymHints) {
250  DsymPaths.push_back(getDarwinDWARFResourceForPath(Path, Filename));
251  }
252  for (const auto &Path : DsymPaths) {
253  auto DbgObjOrErr = getOrCreateObject(Path, ArchName);
254  if (!DbgObjOrErr) {
255  // Ignore errors, the file might not exist.
256  consumeError(DbgObjOrErr.takeError());
257  continue;
258  }
259  ObjectFile *DbgObj = DbgObjOrErr.get();
260  if (!DbgObj)
261  continue;
262  const MachOObjectFile *MachDbgObj = dyn_cast<const MachOObjectFile>(DbgObj);
263  if (!MachDbgObj)
264  continue;
265  if (darwinDsymMatchesBinary(MachDbgObj, MachExeObj))
266  return DbgObj;
267  }
268  return nullptr;
269 }
270 
271 ObjectFile *LLVMSymbolizer::lookUpDebuglinkObject(const std::string &Path,
272  const ObjectFile *Obj,
273  const std::string &ArchName) {
274  std::string DebuglinkName;
275  uint32_t CRCHash;
276  std::string DebugBinaryPath;
277  if (!getGNUDebuglinkContents(Obj, DebuglinkName, CRCHash))
278  return nullptr;
279  if (!findDebugBinary(Path, DebuglinkName, CRCHash, DebugBinaryPath))
280  return nullptr;
281  auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName);
282  if (!DbgObjOrErr) {
283  // Ignore errors, the file might not exist.
284  consumeError(DbgObjOrErr.takeError());
285  return nullptr;
286  }
287  return DbgObjOrErr.get();
288 }
289 
290 Expected<LLVMSymbolizer::ObjectPair>
291 LLVMSymbolizer::getOrCreateObjectPair(const std::string &Path,
292  const std::string &ArchName) {
293  const auto &I = ObjectPairForPathArch.find(std::make_pair(Path, ArchName));
294  if (I != ObjectPairForPathArch.end()) {
295  return I->second;
296  }
297 
298  auto ObjOrErr = getOrCreateObject(Path, ArchName);
299  if (!ObjOrErr) {
300  ObjectPairForPathArch.insert(std::make_pair(std::make_pair(Path, ArchName),
301  ObjectPair(nullptr, nullptr)));
302  return ObjOrErr.takeError();
303  }
304 
305  ObjectFile *Obj = ObjOrErr.get();
306  assert(Obj != nullptr);
307  ObjectFile *DbgObj = nullptr;
308 
309  if (auto MachObj = dyn_cast<const MachOObjectFile>(Obj))
310  DbgObj = lookUpDsymFile(Path, MachObj, ArchName);
311  if (!DbgObj)
312  DbgObj = lookUpDebuglinkObject(Path, Obj, ArchName);
313  if (!DbgObj)
314  DbgObj = Obj;
315  ObjectPair Res = std::make_pair(Obj, DbgObj);
316  ObjectPairForPathArch.insert(
317  std::make_pair(std::make_pair(Path, ArchName), Res));
318  return Res;
319 }
320 
321 Expected<ObjectFile *>
322 LLVMSymbolizer::getOrCreateObject(const std::string &Path,
323  const std::string &ArchName) {
324  const auto &I = BinaryForPath.find(Path);
325  Binary *Bin = nullptr;
326  if (I == BinaryForPath.end()) {
327  Expected<OwningBinary<Binary>> BinOrErr = createBinary(Path);
328  if (!BinOrErr) {
329  BinaryForPath.insert(std::make_pair(Path, OwningBinary<Binary>()));
330  return BinOrErr.takeError();
331  }
332  Bin = BinOrErr->getBinary();
333  BinaryForPath.insert(std::make_pair(Path, std::move(BinOrErr.get())));
334  } else {
335  Bin = I->second.getBinary();
336  }
337 
338  if (!Bin)
339  return static_cast<ObjectFile *>(nullptr);
340 
341  if (MachOUniversalBinary *UB = dyn_cast_or_null<MachOUniversalBinary>(Bin)) {
342  const auto &I = ObjectForUBPathAndArch.find(std::make_pair(Path, ArchName));
343  if (I != ObjectForUBPathAndArch.end()) {
344  return I->second.get();
345  }
346  Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
347  UB->getObjectForArch(ArchName);
348  if (!ObjOrErr) {
349  ObjectForUBPathAndArch.insert(std::make_pair(
350  std::make_pair(Path, ArchName), std::unique_ptr<ObjectFile>()));
351  return ObjOrErr.takeError();
352  }
353  ObjectFile *Res = ObjOrErr->get();
354  ObjectForUBPathAndArch.insert(std::make_pair(std::make_pair(Path, ArchName),
355  std::move(ObjOrErr.get())));
356  return Res;
357  }
358  if (Bin->isObject()) {
359  return cast<ObjectFile>(Bin);
360  }
361  return errorCodeToError(object_error::arch_not_found);
362 }
363 
364 Expected<SymbolizableModule *>
365 LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
366  const auto &I = Modules.find(ModuleName);
367  if (I != Modules.end()) {
368  return I->second.get();
369  }
370  std::string BinaryName = ModuleName;
371  std::string ArchName = Opts.DefaultArch;
372  size_t ColonPos = ModuleName.find_last_of(':');
373  // Verify that substring after colon form a valid arch name.
374  if (ColonPos != std::string::npos) {
375  std::string ArchStr = ModuleName.substr(ColonPos + 1);
376  if (Triple(ArchStr).getArch() != Triple::UnknownArch) {
377  BinaryName = ModuleName.substr(0, ColonPos);
378  ArchName = ArchStr;
379  }
380  }
381  auto ObjectsOrErr = getOrCreateObjectPair(BinaryName, ArchName);
382  if (!ObjectsOrErr) {
383  // Failed to find valid object file.
384  Modules.insert(
385  std::make_pair(ModuleName, std::unique_ptr<SymbolizableModule>()));
386  return ObjectsOrErr.takeError();
387  }
388  ObjectPair Objects = ObjectsOrErr.get();
389 
390  std::unique_ptr<DIContext> Context;
391  // If this is a COFF object containing PDB info, use a PDBContext to
392  // symbolize. Otherwise, use DWARF.
393  if (auto CoffObject = dyn_cast<COFFObjectFile>(Objects.first)) {
394  const codeview::DebugInfo *DebugInfo;
395  StringRef PDBFileName;
396  auto EC = CoffObject->getDebugPDBInfo(DebugInfo, PDBFileName);
397  if (!EC && DebugInfo != nullptr && !PDBFileName.empty()) {
398  using namespace pdb;
399  std::unique_ptr<IPDBSession> Session;
400  if (auto Err = loadDataForEXE(PDB_ReaderType::DIA,
401  Objects.first->getFileName(), Session)) {
402  Modules.insert(
403  std::make_pair(ModuleName, std::unique_ptr<SymbolizableModule>()));
404  return std::move(Err);
405  }
406  Context.reset(new PDBContext(*CoffObject, std::move(Session)));
407  }
408  }
409  if (!Context)
410  Context.reset(new DWARFContextInMemory(*Objects.second));
411  assert(Context);
412  auto InfoOrErr =
413  SymbolizableObjectFile::create(Objects.first, std::move(Context));
414  std::unique_ptr<SymbolizableModule> SymMod;
415  if (InfoOrErr)
416  SymMod = std::move(InfoOrErr.get());
417  auto InsertResult =
418  Modules.insert(std::make_pair(ModuleName, std::move(SymMod)));
419  assert(InsertResult.second);
420  if (auto EC = InfoOrErr.getError())
421  return errorCodeToError(EC);
422  return InsertResult.first->second.get();
423 }
424 
425 namespace {
426 
427 // Undo these various manglings for Win32 extern "C" functions:
428 // cdecl - _foo
429 // stdcall - _foo@12
430 // fastcall - @foo@12
431 // vectorcall - foo@@12
432 // These are all different linkage names for 'foo'.
433 StringRef demanglePE32ExternCFunc(StringRef SymbolName) {
434  // Remove any '_' or '@' prefix.
435  char Front = SymbolName.empty() ? '\0' : SymbolName[0];
436  if (Front == '_' || Front == '@')
437  SymbolName = SymbolName.drop_front();
438 
439  // Remove any '@[0-9]+' suffix.
440  if (Front != '?') {
441  size_t AtPos = SymbolName.rfind('@');
442  if (AtPos != StringRef::npos &&
443  std::all_of(SymbolName.begin() + AtPos + 1, SymbolName.end(),
444  [](char C) { return C >= '0' && C <= '9'; })) {
445  SymbolName = SymbolName.substr(0, AtPos);
446  }
447  }
448 
449  // Remove any ending '@' for vectorcall.
450  if (SymbolName.endswith("@"))
451  SymbolName = SymbolName.drop_back();
452 
453  return SymbolName;
454 }
455 
456 } // end anonymous namespace
457 
458 #if !defined(_MSC_VER)
459 // Assume that __cxa_demangle is provided by libcxxabi (except for Windows).
460 extern "C" char *__cxa_demangle(const char *mangled_name, char *output_buffer,
461  size_t *length, int *status);
462 #endif
463 
464 std::string LLVMSymbolizer::DemangleName(const std::string &Name,
465  const SymbolizableModule *ModInfo) {
466 #if !defined(_MSC_VER)
467  // We can spoil names of symbols with C linkage, so use an heuristic
468  // approach to check if the name should be demangled.
469  if (Name.substr(0, 2) == "_Z") {
470  int status = 0;
471  char *DemangledName = __cxa_demangle(Name.c_str(), nullptr, nullptr, &status);
472  if (status != 0)
473  return Name;
474  std::string Result = DemangledName;
475  free(DemangledName);
476  return Result;
477  }
478 #else
479  if (!Name.empty() && Name.front() == '?') {
480  // Only do MSVC C++ demangling on symbols starting with '?'.
481  char DemangledName[1024] = {0};
482  DWORD result = ::UnDecorateSymbolName(
483  Name.c_str(), DemangledName, 1023,
484  UNDNAME_NO_ACCESS_SPECIFIERS | // Strip public, private, protected
485  UNDNAME_NO_ALLOCATION_LANGUAGE | // Strip __thiscall, __stdcall, etc
486  UNDNAME_NO_THROW_SIGNATURES | // Strip throw() specifications
487  UNDNAME_NO_MEMBER_TYPE | // Strip virtual, static, etc specifiers
488  UNDNAME_NO_MS_KEYWORDS | // Strip all MS extension keywords
489  UNDNAME_NO_FUNCTION_RETURNS); // Strip function return types
490  return (result == 0) ? Name : std::string(DemangledName);
491  }
492 #endif
493  if (ModInfo && ModInfo->isWin32Module())
494  return std::string(demanglePE32ExternCFunc(Name));
495  return Name;
496 }
497 
498 } // namespace symbolize
499 } // namespace llvm
DILineInfo * getMutableFrame(unsigned Index)
Definition: DIContext.h:72
LLVMContext & Context
size_t i
static ErrorOr< std::unique_ptr< SymbolizableObjectFile > > create(object::ObjectFile *Obj, std::unique_ptr< DIContext > DICtx)
virtual DIGlobal symbolizeData(uint64_t ModuleOffset) const =0
virtual DILineInfo symbolizeCode(uint64_t ModuleOffset, FunctionNameKind FNKind, bool UseSymbolTable) const =0
bool all_of(R &&range, UnaryPredicate P)
Provide wrappers to std::all_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:736
virtual bool isWin32Module() const =0
DILineInfo - a format-neutral container for source line information.
Definition: DIContext.h:32
Expected< std::unique_ptr< Binary > > createBinary(MemoryBufferRef Source, LLVMContext *Context=nullptr)
Create a Binary from Source, autodetecting the file type.
Definition: Binary.cpp:39
void append(SmallVectorImpl< char > &path, const Twine &a, const Twine &b="", const Twine &c="", const Twine &d="")
Append to path.
Definition: Path.cpp:448
void remove_filename(SmallVectorImpl< char > &path)
Remove the last component from path unless it is the root dir.
Definition: Path.cpp:501
Expected< DILineInfo > symbolizeCode(const std::string &ModuleName, uint64_t ModuleOffset)
Definition: Symbolize.cpp:54
Tagged union holding either a T or a Error.
StringRef extension(StringRef path)
Get extension.
Definition: Path.cpp:601
SmallString - A SmallString is just a SmallVector with methods and accessors that make it work better...
Definition: SmallString.h:26
static std::string DemangleName(const std::string &Name, const SymbolizableModule *ModInfo)
Definition: Symbolize.cpp:464
uint32_t getNumberOfFrames() const
Definition: DIContext.h:77
bool isAvailable()
Definition: Compression.cpp:48
StringRef filename(StringRef path)
Get filename.
Definition: Path.cpp:584
Error loadDataForEXE(PDB_ReaderType Type, StringRef Path, std::unique_ptr< IPDBSession > &Session)
Definition: PDB.cpp:40
virtual DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset, FunctionNameKind FNKind, bool UseSymbolTable) const =0
Error errorCodeToError(std::error_code EC)
Helper for converting an std::error_code to a Error.
DIInliningInfo - a format-neutral container for inlined code description.
Definition: DIContext.h:61
std::vector< std::string > DsymHints
Definition: Symbolize.h:38
uint32_t Offset
void consumeError(Error Err)
Consume a Error without doing anything.
StringRef relative_path(StringRef path)
Get relative path.
Definition: Path.cpp:443
std::string Name
Definition: DIContext.h:88
char * __cxa_demangle(const char *mangled_name, char *output_buffer, size_t *length, int *status)
std::string FunctionName
Definition: DIContext.h:34
static GCRegistry::Add< ShadowStackGC > C("shadow-stack","Very portable GC for uncooperative code generators")
uint32_t crc32(StringRef Buffer)
Definition: Compression.cpp:86
StringRef str() const
Explicit conversion to StringRef.
Definition: SmallString.h:267
virtual uint64_t getModulePreferredBase() const =0
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFileOrSTDIN(const Twine &Filename, int64_t FileSize=-1, bool RequiresNullTerminator=true)
Open the specified file as a MemoryBuffer, or open stdin if the Filename is "-".
Expected< DIInliningInfo > symbolizeInlinedCode(const std::string &ModuleName, uint64_t ModuleOffset)
Definition: Symbolize.cpp:80
static const size_t npos
Definition: StringRef.h:51
#define I(x, y, z)
Definition: MD5.cpp:54
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:287
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:47
std::error_code status(const Twine &path, file_status &result)
Get file status as if by POSIX stat().
Expected< DIGlobal > symbolizeData(const std::string &ModuleName, uint64_t ModuleOffset)
Definition: Symbolize.cpp:109
DIGlobal - container for description of a global variable.
Definition: DIContext.h:87