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Diffstat (limited to 'llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp')
| -rw-r--r-- | llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp b/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp new file mode 100644 index 0000000000000..b4d49d9ff9582 --- /dev/null +++ b/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp @@ -0,0 +1,331 @@ +//===- SymbolizableObjectFile.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 of SymbolizableObjectFile class. +// +//===----------------------------------------------------------------------===// + +#include "SymbolizableObjectFile.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/Triple.h" +#include "llvm/BinaryFormat/COFF.h" +#include "llvm/DebugInfo/DWARF/DWARFContext.h" +#include "llvm/DebugInfo/Symbolize/SymbolizableModule.h" +#include "llvm/Object/COFF.h" +#include "llvm/Object/ObjectFile.h" +#include "llvm/Object/SymbolSize.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/DataExtractor.h" +#include "llvm/Support/Error.h" +#include <algorithm> +#include <cstdint> +#include <memory> +#include <string> +#include <system_error> +#include <utility> +#include <vector> + +using namespace llvm; +using namespace object; +using namespace symbolize; + +static DILineInfoSpecifier +getDILineInfoSpecifier(FunctionNameKind FNKind) { + return DILineInfoSpecifier( + DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, FNKind); +} + +ErrorOr<std::unique_ptr<SymbolizableObjectFile>> +SymbolizableObjectFile::create(const object::ObjectFile *Obj, + std::unique_ptr<DIContext> DICtx, + bool UntagAddresses) { + assert(DICtx); + std::unique_ptr<SymbolizableObjectFile> res( + new SymbolizableObjectFile(Obj, std::move(DICtx), UntagAddresses)); + std::unique_ptr<DataExtractor> OpdExtractor; + uint64_t OpdAddress = 0; + // Find the .opd (function descriptor) section if any, for big-endian + // PowerPC64 ELF. + if (Obj->getArch() == Triple::ppc64) { + for (section_iterator Section : Obj->sections()) { + Expected<StringRef> NameOrErr = Section->getName(); + if (!NameOrErr) + return errorToErrorCode(NameOrErr.takeError()); + + if (*NameOrErr == ".opd") { + Expected<StringRef> E = Section->getContents(); + if (!E) + return errorToErrorCode(E.takeError()); + OpdExtractor.reset(new DataExtractor(*E, Obj->isLittleEndian(), + Obj->getBytesInAddress())); + OpdAddress = Section->getAddress(); + break; + } + } + } + std::vector<std::pair<SymbolRef, uint64_t>> Symbols = + computeSymbolSizes(*Obj); + for (auto &P : Symbols) + res->addSymbol(P.first, P.second, OpdExtractor.get(), OpdAddress); + + // If this is a COFF object and we didn't find any symbols, try the export + // table. + if (Symbols.empty()) { + if (auto *CoffObj = dyn_cast<COFFObjectFile>(Obj)) + if (auto EC = res->addCoffExportSymbols(CoffObj)) + return EC; + } + + std::vector<std::pair<SymbolDesc, StringRef>> &Fs = res->Functions, + &Os = res->Objects; + auto Uniquify = [](std::vector<std::pair<SymbolDesc, StringRef>> &S) { + // Sort by (Addr,Size,Name). If several SymbolDescs share the same Addr, + // pick the one with the largest Size. This helps us avoid symbols with no + // size information (Size=0). + llvm::sort(S); + auto I = S.begin(), E = S.end(), J = S.begin(); + while (I != E) { + auto OI = I; + while (++I != E && OI->first.Addr == I->first.Addr) { + } + *J++ = I[-1]; + } + S.erase(J, S.end()); + }; + Uniquify(Fs); + Uniquify(Os); + + return std::move(res); +} + +SymbolizableObjectFile::SymbolizableObjectFile(const ObjectFile *Obj, + std::unique_ptr<DIContext> DICtx, + bool UntagAddresses) + : Module(Obj), DebugInfoContext(std::move(DICtx)), + UntagAddresses(UntagAddresses) {} + +namespace { + +struct OffsetNamePair { + uint32_t Offset; + StringRef Name; + + bool operator<(const OffsetNamePair &R) const { + return Offset < R.Offset; + } +}; + +} // end anonymous namespace + +std::error_code SymbolizableObjectFile::addCoffExportSymbols( + const COFFObjectFile *CoffObj) { + // Get all export names and offsets. + std::vector<OffsetNamePair> ExportSyms; + for (const ExportDirectoryEntryRef &Ref : CoffObj->export_directories()) { + StringRef Name; + uint32_t Offset; + if (auto EC = Ref.getSymbolName(Name)) + return EC; + if (auto EC = Ref.getExportRVA(Offset)) + return EC; + ExportSyms.push_back(OffsetNamePair{Offset, Name}); + } + if (ExportSyms.empty()) + return std::error_code(); + + // Sort by ascending offset. + array_pod_sort(ExportSyms.begin(), ExportSyms.end()); + + // Approximate the symbol sizes by assuming they run to the next symbol. + // FIXME: This assumes all exports are functions. + uint64_t ImageBase = CoffObj->getImageBase(); + for (auto I = ExportSyms.begin(), E = ExportSyms.end(); I != E; ++I) { + OffsetNamePair &Export = *I; + // FIXME: The last export has a one byte size now. + uint32_t NextOffset = I != E ? I->Offset : Export.Offset + 1; + uint64_t SymbolStart = ImageBase + Export.Offset; + uint64_t SymbolSize = NextOffset - Export.Offset; + SymbolDesc SD = {SymbolStart, SymbolSize}; + Functions.emplace_back(SD, Export.Name); + } + return std::error_code(); +} + +std::error_code SymbolizableObjectFile::addSymbol(const SymbolRef &Symbol, + uint64_t SymbolSize, + DataExtractor *OpdExtractor, + uint64_t OpdAddress) { + // Avoid adding symbols from an unknown/undefined section. + const ObjectFile *Obj = Symbol.getObject(); + Expected<section_iterator> Sec = Symbol.getSection(); + if (!Sec || (Obj && Obj->section_end() == *Sec)) + return std::error_code(); + Expected<SymbolRef::Type> SymbolTypeOrErr = Symbol.getType(); + if (!SymbolTypeOrErr) + return errorToErrorCode(SymbolTypeOrErr.takeError()); + SymbolRef::Type SymbolType = *SymbolTypeOrErr; + if (SymbolType != SymbolRef::ST_Function && SymbolType != SymbolRef::ST_Data) + return std::error_code(); + Expected<uint64_t> SymbolAddressOrErr = Symbol.getAddress(); + if (!SymbolAddressOrErr) + return errorToErrorCode(SymbolAddressOrErr.takeError()); + uint64_t SymbolAddress = *SymbolAddressOrErr; + if (UntagAddresses) { + // For kernel addresses, bits 56-63 need to be set, so we sign extend bit 55 + // into bits 56-63 instead of masking them out. + SymbolAddress &= (1ull << 56) - 1; + SymbolAddress = (int64_t(SymbolAddress) << 8) >> 8; + } + if (OpdExtractor) { + // For big-endian PowerPC64 ELF, symbols in the .opd section refer to + // function descriptors. The first word of the descriptor is a pointer to + // the function's code. + // For the purposes of symbolization, pretend the symbol's address is that + // of the function's code, not the descriptor. + uint64_t OpdOffset = SymbolAddress - OpdAddress; + if (OpdExtractor->isValidOffsetForAddress(OpdOffset)) + SymbolAddress = OpdExtractor->getAddress(&OpdOffset); + } + Expected<StringRef> SymbolNameOrErr = Symbol.getName(); + if (!SymbolNameOrErr) + return errorToErrorCode(SymbolNameOrErr.takeError()); + StringRef SymbolName = *SymbolNameOrErr; + // Mach-O symbol table names have leading underscore, skip it. + if (Module->isMachO() && !SymbolName.empty() && SymbolName[0] == '_') + SymbolName = SymbolName.drop_front(); + // FIXME: If a function has alias, there are two entries in symbol table + // with same address size. Make sure we choose the correct one. + auto &M = SymbolType == SymbolRef::ST_Function ? Functions : Objects; + SymbolDesc SD = { SymbolAddress, SymbolSize }; + M.emplace_back(SD, SymbolName); + return std::error_code(); +} + +// Return true if this is a 32-bit x86 PE COFF module. +bool SymbolizableObjectFile::isWin32Module() const { + auto *CoffObject = dyn_cast<COFFObjectFile>(Module); + return CoffObject && CoffObject->getMachine() == COFF::IMAGE_FILE_MACHINE_I386; +} + +uint64_t SymbolizableObjectFile::getModulePreferredBase() const { + if (auto *CoffObject = dyn_cast<COFFObjectFile>(Module)) + return CoffObject->getImageBase(); + return 0; +} + +bool SymbolizableObjectFile::getNameFromSymbolTable(SymbolRef::Type Type, + uint64_t Address, + std::string &Name, + uint64_t &Addr, + uint64_t &Size) const { + const auto &Symbols = Type == SymbolRef::ST_Function ? Functions : Objects; + std::pair<SymbolDesc, StringRef> SD{{Address, UINT64_C(-1)}, StringRef()}; + auto SymbolIterator = llvm::upper_bound(Symbols, SD); + if (SymbolIterator == Symbols.begin()) + return false; + --SymbolIterator; + if (SymbolIterator->first.Size != 0 && + SymbolIterator->first.Addr + SymbolIterator->first.Size <= Address) + return false; + Name = SymbolIterator->second.str(); + Addr = SymbolIterator->first.Addr; + Size = SymbolIterator->first.Size; + return true; +} + +bool SymbolizableObjectFile::shouldOverrideWithSymbolTable( + FunctionNameKind FNKind, bool UseSymbolTable) const { + // When DWARF is used with -gline-tables-only / -gmlt, the symbol table gives + // better answers for linkage names than the DIContext. Otherwise, we are + // probably using PEs and PDBs, and we shouldn't do the override. PE files + // generally only contain the names of exported symbols. + return FNKind == FunctionNameKind::LinkageName && UseSymbolTable && + isa<DWARFContext>(DebugInfoContext.get()); +} + +DILineInfo +SymbolizableObjectFile::symbolizeCode(object::SectionedAddress ModuleOffset, + FunctionNameKind FNKind, + bool UseSymbolTable) const { + if (ModuleOffset.SectionIndex == object::SectionedAddress::UndefSection) + ModuleOffset.SectionIndex = + getModuleSectionIndexForAddress(ModuleOffset.Address); + DILineInfo LineInfo = DebugInfoContext->getLineInfoForAddress( + ModuleOffset, getDILineInfoSpecifier(FNKind)); + + // Override function name from symbol table if necessary. + if (shouldOverrideWithSymbolTable(FNKind, UseSymbolTable)) { + std::string FunctionName; + uint64_t Start, Size; + if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset.Address, + FunctionName, Start, Size)) { + LineInfo.FunctionName = FunctionName; + } + } + return LineInfo; +} + +DIInliningInfo SymbolizableObjectFile::symbolizeInlinedCode( + object::SectionedAddress ModuleOffset, FunctionNameKind FNKind, + bool UseSymbolTable) const { + if (ModuleOffset.SectionIndex == object::SectionedAddress::UndefSection) + ModuleOffset.SectionIndex = + getModuleSectionIndexForAddress(ModuleOffset.Address); + DIInliningInfo InlinedContext = DebugInfoContext->getInliningInfoForAddress( + ModuleOffset, getDILineInfoSpecifier(FNKind)); + + // Make sure there is at least one frame in context. + if (InlinedContext.getNumberOfFrames() == 0) + InlinedContext.addFrame(DILineInfo()); + + // Override the function name in lower frame with name from symbol table. + if (shouldOverrideWithSymbolTable(FNKind, UseSymbolTable)) { + std::string FunctionName; + uint64_t Start, Size; + if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset.Address, + FunctionName, Start, Size)) { + InlinedContext.getMutableFrame(InlinedContext.getNumberOfFrames() - 1) + ->FunctionName = FunctionName; + } + } + + return InlinedContext; +} + +DIGlobal SymbolizableObjectFile::symbolizeData( + object::SectionedAddress ModuleOffset) const { + DIGlobal Res; + getNameFromSymbolTable(SymbolRef::ST_Data, ModuleOffset.Address, Res.Name, + Res.Start, Res.Size); + return Res; +} + +std::vector<DILocal> SymbolizableObjectFile::symbolizeFrame( + object::SectionedAddress ModuleOffset) const { + if (ModuleOffset.SectionIndex == object::SectionedAddress::UndefSection) + ModuleOffset.SectionIndex = + getModuleSectionIndexForAddress(ModuleOffset.Address); + return DebugInfoContext->getLocalsForAddress(ModuleOffset); +} + +/// Search for the first occurence of specified Address in ObjectFile. +uint64_t SymbolizableObjectFile::getModuleSectionIndexForAddress( + uint64_t Address) const { + + for (SectionRef Sec : Module->sections()) { + if (!Sec.isText() || Sec.isVirtual()) + continue; + + if (Address >= Sec.getAddress() && + Address < Sec.getAddress() + Sec.getSize()) + return Sec.getIndex(); + } + + return object::SectionedAddress::UndefSection; +} |