//===-- LLVMSymbolize.cpp -------------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // Implementation for LLVM symbolization library. // //===----------------------------------------------------------------------===// #include "llvm/DebugInfo/Symbolize/Symbolize.h" #include "SymbolizableObjectFile.h" #include "llvm/ADT/STLExtras.h" #include "llvm/BinaryFormat/COFF.h" #include "llvm/DebugInfo/DWARF/DWARFContext.h" #include "llvm/DebugInfo/PDB/PDB.h" #include "llvm/DebugInfo/PDB/PDBContext.h" #include "llvm/Demangle/Demangle.h" #include "llvm/Object/COFF.h" #include "llvm/Object/MachO.h" #include "llvm/Object/MachOUniversal.h" #include "llvm/Support/CRC.h" #include "llvm/Support/Casting.h" #include "llvm/Support/Compression.h" #include "llvm/Support/DataExtractor.h" #include "llvm/Support/Errc.h" #include "llvm/Support/FileSystem.h" #include "llvm/Support/MemoryBuffer.h" #include "llvm/Support/Path.h" #include #include #include namespace llvm { namespace symbolize { Expected LLVMSymbolizer::symbolizeCodeCommon(SymbolizableModule *Info, object::SectionedAddress ModuleOffset) { // A null module means an error has already been reported. Return an empty // result. if (!Info) return DILineInfo(); // If the user is giving us relative addresses, add the preferred base of the // object to the offset before we do the query. It's what DIContext expects. if (Opts.RelativeAddresses) ModuleOffset.Address += Info->getModulePreferredBase(); DILineInfo LineInfo = Info->symbolizeCode(ModuleOffset, Opts.PrintFunctions, Opts.UseSymbolTable); if (Opts.Demangle) LineInfo.FunctionName = DemangleName(LineInfo.FunctionName, Info); return LineInfo; } Expected LLVMSymbolizer::symbolizeCode(const ObjectFile &Obj, object::SectionedAddress ModuleOffset) { StringRef ModuleName = Obj.getFileName(); auto I = Modules.find(ModuleName); if (I != Modules.end()) return symbolizeCodeCommon(I->second.get(), ModuleOffset); std::unique_ptr Context = DWARFContext::create(Obj, nullptr, DWARFContext::defaultErrorHandler); Expected InfoOrErr = createModuleInfo(&Obj, std::move(Context), ModuleName); if (!InfoOrErr) return InfoOrErr.takeError(); return symbolizeCodeCommon(*InfoOrErr, ModuleOffset); } Expected LLVMSymbolizer::symbolizeCode(const std::string &ModuleName, object::SectionedAddress ModuleOffset) { Expected InfoOrErr = getOrCreateModuleInfo(ModuleName); if (!InfoOrErr) return InfoOrErr.takeError(); return symbolizeCodeCommon(*InfoOrErr, ModuleOffset); } Expected LLVMSymbolizer::symbolizeInlinedCode(const std::string &ModuleName, object::SectionedAddress ModuleOffset) { SymbolizableModule *Info; if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName)) Info = InfoOrErr.get(); else return InfoOrErr.takeError(); // A null module means an error has already been reported. Return an empty // result. if (!Info) return DIInliningInfo(); // If the user is giving us relative addresses, add the preferred base of the // object to the offset before we do the query. It's what DIContext expects. if (Opts.RelativeAddresses) ModuleOffset.Address += Info->getModulePreferredBase(); DIInliningInfo InlinedContext = Info->symbolizeInlinedCode( ModuleOffset, Opts.PrintFunctions, Opts.UseSymbolTable); if (Opts.Demangle) { for (int i = 0, n = InlinedContext.getNumberOfFrames(); i < n; i++) { auto *Frame = InlinedContext.getMutableFrame(i); Frame->FunctionName = DemangleName(Frame->FunctionName, Info); } } return InlinedContext; } Expected LLVMSymbolizer::symbolizeData(const std::string &ModuleName, object::SectionedAddress ModuleOffset) { SymbolizableModule *Info; if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName)) Info = InfoOrErr.get(); else return InfoOrErr.takeError(); // A null module means an error has already been reported. Return an empty // result. if (!Info) return DIGlobal(); // If the user is giving us relative addresses, add the preferred base of // the object to the offset before we do the query. It's what DIContext // expects. if (Opts.RelativeAddresses) ModuleOffset.Address += Info->getModulePreferredBase(); DIGlobal Global = Info->symbolizeData(ModuleOffset); if (Opts.Demangle) Global.Name = DemangleName(Global.Name, Info); return Global; } Expected> LLVMSymbolizer::symbolizeFrame(const std::string &ModuleName, object::SectionedAddress ModuleOffset) { SymbolizableModule *Info; if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName)) Info = InfoOrErr.get(); else return InfoOrErr.takeError(); // A null module means an error has already been reported. Return an empty // result. if (!Info) return std::vector(); // If the user is giving us relative addresses, add the preferred base of // the object to the offset before we do the query. It's what DIContext // expects. if (Opts.RelativeAddresses) ModuleOffset.Address += Info->getModulePreferredBase(); return Info->symbolizeFrame(ModuleOffset); } void LLVMSymbolizer::flush() { ObjectForUBPathAndArch.clear(); BinaryForPath.clear(); ObjectPairForPathArch.clear(); Modules.clear(); } namespace { // For Path="/path/to/foo" and Basename="foo" assume that debug info is in // /path/to/foo.dSYM/Contents/Resources/DWARF/foo. // For Path="/path/to/bar.dSYM" and Basename="foo" assume that debug info is in // /path/to/bar.dSYM/Contents/Resources/DWARF/foo. std::string getDarwinDWARFResourceForPath( const std::string &Path, const std::string &Basename) { SmallString<16> ResourceName = StringRef(Path); if (sys::path::extension(Path) != ".dSYM") { ResourceName += ".dSYM"; } sys::path::append(ResourceName, "Contents", "Resources", "DWARF"); sys::path::append(ResourceName, Basename); return ResourceName.str(); } bool checkFileCRC(StringRef Path, uint32_t CRCHash) { ErrorOr> MB = MemoryBuffer::getFileOrSTDIN(Path); if (!MB) return false; return CRCHash == llvm::crc32(arrayRefFromStringRef(MB.get()->getBuffer())); } bool findDebugBinary(const std::string &OrigPath, const std::string &DebuglinkName, uint32_t CRCHash, const std::string &FallbackDebugPath, std::string &Result) { SmallString<16> OrigDir(OrigPath); llvm::sys::path::remove_filename(OrigDir); SmallString<16> DebugPath = OrigDir; // Try relative/path/to/original_binary/debuglink_name llvm::sys::path::append(DebugPath, DebuglinkName); if (checkFileCRC(DebugPath, CRCHash)) { Result = DebugPath.str(); return true; } // Try relative/path/to/original_binary/.debug/debuglink_name DebugPath = OrigDir; llvm::sys::path::append(DebugPath, ".debug", DebuglinkName); if (checkFileCRC(DebugPath, CRCHash)) { Result = DebugPath.str(); return true; } // Make the path absolute so that lookups will go to // "/usr/lib/debug/full/path/to/debug", not // "/usr/lib/debug/to/debug" llvm::sys::fs::make_absolute(OrigDir); if (!FallbackDebugPath.empty()) { // Try /absolute/path/to/original_binary/debuglink_name DebugPath = FallbackDebugPath; } else { #if defined(__NetBSD__) // Try /usr/libdata/debug/absolute/path/to/original_binary/debuglink_name DebugPath = "/usr/libdata/debug"; #else // Try /usr/lib/debug/absolute/path/to/original_binary/debuglink_name DebugPath = "/usr/lib/debug"; #endif } llvm::sys::path::append(DebugPath, llvm::sys::path::relative_path(OrigDir), DebuglinkName); if (checkFileCRC(DebugPath, CRCHash)) { Result = DebugPath.str(); return true; } return false; } bool getGNUDebuglinkContents(const ObjectFile *Obj, std::string &DebugName, uint32_t &CRCHash) { if (!Obj) return false; for (const SectionRef &Section : Obj->sections()) { StringRef Name; if (Expected NameOrErr = Section.getName()) Name = *NameOrErr; else consumeError(NameOrErr.takeError()); Name = Name.substr(Name.find_first_not_of("._")); if (Name == "gnu_debuglink") { Expected ContentsOrErr = Section.getContents(); if (!ContentsOrErr) { consumeError(ContentsOrErr.takeError()); return false; } DataExtractor DE(*ContentsOrErr, Obj->isLittleEndian(), 0); uint64_t Offset = 0; if (const char *DebugNameStr = DE.getCStr(&Offset)) { // 4-byte align the offset. Offset = (Offset + 3) & ~0x3; if (DE.isValidOffsetForDataOfSize(Offset, 4)) { DebugName = DebugNameStr; CRCHash = DE.getU32(&Offset); return true; } } break; } } return false; } bool darwinDsymMatchesBinary(const MachOObjectFile *DbgObj, const MachOObjectFile *Obj) { ArrayRef dbg_uuid = DbgObj->getUuid(); ArrayRef bin_uuid = Obj->getUuid(); if (dbg_uuid.empty() || bin_uuid.empty()) return false; return !memcmp(dbg_uuid.data(), bin_uuid.data(), dbg_uuid.size()); } template Optional> getBuildID(const ELFFile *Obj) { if (!Obj) return {}; auto PhdrsOrErr = Obj->program_headers(); if (!PhdrsOrErr) { consumeError(PhdrsOrErr.takeError()); return {}; } for (const auto &P : *PhdrsOrErr) { if (P.p_type != ELF::PT_NOTE) continue; Error Err = Error::success(); for (auto N : Obj->notes(P, Err)) if (N.getType() == ELF::NT_GNU_BUILD_ID && N.getName() == ELF::ELF_NOTE_GNU) return N.getDesc(); } return {}; } Optional> getBuildID(const ELFObjectFileBase *Obj) { Optional> BuildID; if (auto *O = dyn_cast>(Obj)) BuildID = getBuildID(O->getELFFile()); else if (auto *O = dyn_cast>(Obj)) BuildID = getBuildID(O->getELFFile()); else if (auto *O = dyn_cast>(Obj)) BuildID = getBuildID(O->getELFFile()); else if (auto *O = dyn_cast>(Obj)) BuildID = getBuildID(O->getELFFile()); else llvm_unreachable("unsupported file format"); return BuildID; } bool findDebugBinary(const std::vector &DebugFileDirectory, const ArrayRef BuildID, std::string &Result) { auto getDebugPath = [&](StringRef Directory) { SmallString<128> Path{Directory}; sys::path::append(Path, ".build-id", llvm::toHex(BuildID[0], /*LowerCase=*/true), llvm::toHex(BuildID.slice(1), /*LowerCase=*/true)); Path += ".debug"; return Path; }; if (DebugFileDirectory.empty()) { SmallString<128> Path = getDebugPath( #if defined(__NetBSD__) // Try /usr/libdata/debug/.build-id/../... "/usr/libdata/debug" #else // Try /usr/lib/debug/.build-id/../... "/usr/lib/debug" #endif ); if (llvm::sys::fs::exists(Path)) { Result = Path.str(); return true; } } else { for (const auto &Directory : DebugFileDirectory) { // Try /.build-id/../... SmallString<128> Path = getDebugPath(Directory); if (llvm::sys::fs::exists(Path)) { Result = Path.str(); return true; } } } return false; } } // end anonymous namespace ObjectFile *LLVMSymbolizer::lookUpDsymFile(const std::string &ExePath, const MachOObjectFile *MachExeObj, const std::string &ArchName) { // On Darwin we may find DWARF in separate object file in // resource directory. std::vector DsymPaths; StringRef Filename = sys::path::filename(ExePath); DsymPaths.push_back(getDarwinDWARFResourceForPath(ExePath, Filename)); for (const auto &Path : Opts.DsymHints) { DsymPaths.push_back(getDarwinDWARFResourceForPath(Path, Filename)); } for (const auto &Path : DsymPaths) { auto DbgObjOrErr = getOrCreateObject(Path, ArchName); if (!DbgObjOrErr) { // Ignore errors, the file might not exist. consumeError(DbgObjOrErr.takeError()); continue; } ObjectFile *DbgObj = DbgObjOrErr.get(); if (!DbgObj) continue; const MachOObjectFile *MachDbgObj = dyn_cast(DbgObj); if (!MachDbgObj) continue; if (darwinDsymMatchesBinary(MachDbgObj, MachExeObj)) return DbgObj; } return nullptr; } ObjectFile *LLVMSymbolizer::lookUpDebuglinkObject(const std::string &Path, const ObjectFile *Obj, const std::string &ArchName) { std::string DebuglinkName; uint32_t CRCHash; std::string DebugBinaryPath; if (!getGNUDebuglinkContents(Obj, DebuglinkName, CRCHash)) return nullptr; if (!findDebugBinary(Path, DebuglinkName, CRCHash, Opts.FallbackDebugPath, DebugBinaryPath)) return nullptr; auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName); if (!DbgObjOrErr) { // Ignore errors, the file might not exist. consumeError(DbgObjOrErr.takeError()); return nullptr; } return DbgObjOrErr.get(); } ObjectFile *LLVMSymbolizer::lookUpBuildIDObject(const std::string &Path, const ELFObjectFileBase *Obj, const std::string &ArchName) { auto BuildID = getBuildID(Obj); if (!BuildID) return nullptr; if (BuildID->size() < 2) return nullptr; std::string DebugBinaryPath; if (!findDebugBinary(Opts.DebugFileDirectory, *BuildID, DebugBinaryPath)) return nullptr; auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName); if (!DbgObjOrErr) { consumeError(DbgObjOrErr.takeError()); return nullptr; } return DbgObjOrErr.get(); } Expected LLVMSymbolizer::getOrCreateObjectPair(const std::string &Path, const std::string &ArchName) { auto I = ObjectPairForPathArch.find(std::make_pair(Path, ArchName)); if (I != ObjectPairForPathArch.end()) return I->second; auto ObjOrErr = getOrCreateObject(Path, ArchName); if (!ObjOrErr) { ObjectPairForPathArch.emplace(std::make_pair(Path, ArchName), ObjectPair(nullptr, nullptr)); return ObjOrErr.takeError(); } ObjectFile *Obj = ObjOrErr.get(); assert(Obj != nullptr); ObjectFile *DbgObj = nullptr; if (auto MachObj = dyn_cast(Obj)) DbgObj = lookUpDsymFile(Path, MachObj, ArchName); else if (auto ELFObj = dyn_cast(Obj)) DbgObj = lookUpBuildIDObject(Path, ELFObj, ArchName); if (!DbgObj) DbgObj = lookUpDebuglinkObject(Path, Obj, ArchName); if (!DbgObj) DbgObj = Obj; ObjectPair Res = std::make_pair(Obj, DbgObj); ObjectPairForPathArch.emplace(std::make_pair(Path, ArchName), Res); return Res; } Expected LLVMSymbolizer::getOrCreateObject(const std::string &Path, const std::string &ArchName) { Binary *Bin; auto Pair = BinaryForPath.emplace(Path, OwningBinary()); if (!Pair.second) { Bin = Pair.first->second.getBinary(); } else { Expected> BinOrErr = createBinary(Path); if (!BinOrErr) return BinOrErr.takeError(); Pair.first->second = std::move(BinOrErr.get()); Bin = Pair.first->second.getBinary(); } if (!Bin) return static_cast(nullptr); if (MachOUniversalBinary *UB = dyn_cast_or_null(Bin)) { auto I = ObjectForUBPathAndArch.find(std::make_pair(Path, ArchName)); if (I != ObjectForUBPathAndArch.end()) return I->second.get(); Expected> ObjOrErr = UB->getMachOObjectForArch(ArchName); if (!ObjOrErr) { ObjectForUBPathAndArch.emplace(std::make_pair(Path, ArchName), std::unique_ptr()); return ObjOrErr.takeError(); } ObjectFile *Res = ObjOrErr->get(); ObjectForUBPathAndArch.emplace(std::make_pair(Path, ArchName), std::move(ObjOrErr.get())); return Res; } if (Bin->isObject()) { return cast(Bin); } return errorCodeToError(object_error::arch_not_found); } Expected LLVMSymbolizer::createModuleInfo(const ObjectFile *Obj, std::unique_ptr Context, StringRef ModuleName) { auto InfoOrErr = SymbolizableObjectFile::create(Obj, std::move(Context), Opts.UntagAddresses); std::unique_ptr SymMod; if (InfoOrErr) SymMod = std::move(*InfoOrErr); auto InsertResult = Modules.insert(std::make_pair(ModuleName, std::move(SymMod))); assert(InsertResult.second); if (std::error_code EC = InfoOrErr.getError()) return errorCodeToError(EC); return InsertResult.first->second.get(); } Expected LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) { auto I = Modules.find(ModuleName); if (I != Modules.end()) return I->second.get(); std::string BinaryName = ModuleName; std::string ArchName = Opts.DefaultArch; size_t ColonPos = ModuleName.find_last_of(':'); // Verify that substring after colon form a valid arch name. if (ColonPos != std::string::npos) { std::string ArchStr = ModuleName.substr(ColonPos + 1); if (Triple(ArchStr).getArch() != Triple::UnknownArch) { BinaryName = ModuleName.substr(0, ColonPos); ArchName = ArchStr; } } auto ObjectsOrErr = getOrCreateObjectPair(BinaryName, ArchName); if (!ObjectsOrErr) { // Failed to find valid object file. Modules.emplace(ModuleName, std::unique_ptr()); return ObjectsOrErr.takeError(); } ObjectPair Objects = ObjectsOrErr.get(); std::unique_ptr Context; // If this is a COFF object containing PDB info, use a PDBContext to // symbolize. Otherwise, use DWARF. if (auto CoffObject = dyn_cast(Objects.first)) { const codeview::DebugInfo *DebugInfo; StringRef PDBFileName; auto EC = CoffObject->getDebugPDBInfo(DebugInfo, PDBFileName); if (!EC && DebugInfo != nullptr && !PDBFileName.empty()) { #if 0 using namespace pdb; std::unique_ptr Session; if (auto Err = loadDataForEXE(PDB_ReaderType::DIA, Objects.first->getFileName(), Session)) { Modules.emplace(ModuleName, std::unique_ptr()); // Return along the PDB filename to provide more context return createFileError(PDBFileName, std::move(Err)); } Context.reset(new PDBContext(*CoffObject, std::move(Session))); #else return make_error( "PDB support not compiled in", std::make_error_code(std::errc::not_supported)); #endif } } if (!Context) Context = DWARFContext::create(*Objects.second, nullptr, DWARFContext::defaultErrorHandler, Opts.DWPName); return createModuleInfo(Objects.first, std::move(Context), ModuleName); } namespace { // Undo these various manglings for Win32 extern "C" functions: // cdecl - _foo // stdcall - _foo@12 // fastcall - @foo@12 // vectorcall - foo@@12 // These are all different linkage names for 'foo'. StringRef demanglePE32ExternCFunc(StringRef SymbolName) { // Remove any '_' or '@' prefix. char Front = SymbolName.empty() ? '\0' : SymbolName[0]; if (Front == '_' || Front == '@') SymbolName = SymbolName.drop_front(); // Remove any '@[0-9]+' suffix. if (Front != '?') { size_t AtPos = SymbolName.rfind('@'); if (AtPos != StringRef::npos && std::all_of(SymbolName.begin() + AtPos + 1, SymbolName.end(), [](char C) { return C >= '0' && C <= '9'; })) { SymbolName = SymbolName.substr(0, AtPos); } } // Remove any ending '@' for vectorcall. if (SymbolName.endswith("@")) SymbolName = SymbolName.drop_back(); return SymbolName; } } // end anonymous namespace std::string LLVMSymbolizer::DemangleName(const std::string &Name, const SymbolizableModule *DbiModuleDescriptor) { // We can spoil names of symbols with C linkage, so use an heuristic // approach to check if the name should be demangled. if (Name.substr(0, 2) == "_Z") { int status = 0; char *DemangledName = itaniumDemangle(Name.c_str(), nullptr, nullptr, &status); if (status != 0) return Name; std::string Result = DemangledName; free(DemangledName); return Result; } if (!Name.empty() && Name.front() == '?') { // Only do MSVC C++ demangling on symbols starting with '?'. int status = 0; char *DemangledName = microsoftDemangle( Name.c_str(), nullptr, nullptr, &status, MSDemangleFlags(MSDF_NoAccessSpecifier | MSDF_NoCallingConvention | MSDF_NoMemberType | MSDF_NoReturnType)); if (status != 0) return Name; std::string Result = DemangledName; free(DemangledName); return Result; } if (DbiModuleDescriptor && DbiModuleDescriptor->isWin32Module()) return std::string(demanglePE32ExternCFunc(Name)); return Name; } } // namespace symbolize } // namespace llvm