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Diffstat (limited to 'contrib/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp')
| -rw-r--r-- | contrib/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/contrib/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp b/contrib/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp new file mode 100644 index 000000000000..e31462459844 --- /dev/null +++ b/contrib/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp @@ -0,0 +1,254 @@ +//===-- SymbolizableObjectFile.cpp ----------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Implementation of SymbolizableObjectFile class. +// +//===----------------------------------------------------------------------===// + +#include "SymbolizableObjectFile.h" +#include "llvm/Object/SymbolSize.h" +#include "llvm/Support/DataExtractor.h" +#include "llvm/DebugInfo/DWARF/DWARFContext.h" + +namespace llvm { +namespace symbolize { + +using namespace object; + +static DILineInfoSpecifier +getDILineInfoSpecifier(FunctionNameKind FNKind) { + return DILineInfoSpecifier( + DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, FNKind); +} + +ErrorOr<std::unique_ptr<SymbolizableObjectFile>> +SymbolizableObjectFile::create(object::ObjectFile *Obj, + std::unique_ptr<DIContext> DICtx) { + std::unique_ptr<SymbolizableObjectFile> res( + new SymbolizableObjectFile(Obj, std::move(DICtx))); + 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()) { + StringRef Name; + StringRef Data; + if (auto EC = Section->getName(Name)) + return EC; + if (Name == ".opd") { + if (auto EC = Section->getContents(Data)) + return EC; + OpdExtractor.reset(new DataExtractor(Data, 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; + } + return std::move(res); +} + +SymbolizableObjectFile::SymbolizableObjectFile(ObjectFile *Obj, + std::unique_ptr<DIContext> DICtx) + : Module(Obj), DebugInfoContext(std::move(DICtx)) {} + +namespace { +struct OffsetNamePair { + uint32_t Offset; + StringRef Name; + bool operator<(const OffsetNamePair &R) const { + return Offset < R.Offset; + } +}; +} + +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.insert(std::make_pair(SD, Export.Name)); + } + return std::error_code(); +} + +std::error_code SymbolizableObjectFile::addSymbol(const SymbolRef &Symbol, + uint64_t SymbolSize, + DataExtractor *OpdExtractor, + uint64_t OpdAddress) { + SymbolRef::Type SymbolType = Symbol.getType(); + if (SymbolType != SymbolRef::ST_Function && SymbolType != SymbolRef::ST_Data) + return std::error_code(); + ErrorOr<uint64_t> SymbolAddressOrErr = Symbol.getAddress(); + if (auto EC = SymbolAddressOrErr.getError()) + return EC; + uint64_t SymbolAddress = *SymbolAddressOrErr; + 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; + uint32_t OpdOffset32 = OpdOffset; + if (OpdOffset == OpdOffset32 && + OpdExtractor->isValidOffsetForAddress(OpdOffset32)) + SymbolAddress = OpdExtractor->getAddress(&OpdOffset32); + } + ErrorOr<StringRef> SymbolNameOrErr = Symbol.getName(); + if (auto EC = SymbolNameOrErr.getError()) + return EC; + StringRef SymbolName = *SymbolNameOrErr; + // Mach-O symbol table names have leading underscore, skip it. + if (Module->isMachO() && SymbolName.size() > 0 && 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.insert(std::make_pair(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 &SymbolMap = Type == SymbolRef::ST_Function ? Functions : Objects; + if (SymbolMap.empty()) + return false; + SymbolDesc SD = { Address, Address }; + auto SymbolIterator = SymbolMap.upper_bound(SD); + if (SymbolIterator == SymbolMap.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(uint64_t ModuleOffset, + FunctionNameKind FNKind, + bool UseSymbolTable) const { + DILineInfo LineInfo; + if (DebugInfoContext) { + 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, + FunctionName, Start, Size)) { + LineInfo.FunctionName = FunctionName; + } + } + return LineInfo; +} + +DIInliningInfo SymbolizableObjectFile::symbolizeInlinedCode( + uint64_t ModuleOffset, FunctionNameKind FNKind, bool UseSymbolTable) const { + DIInliningInfo InlinedContext; + + if (DebugInfoContext) + 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, + FunctionName, Start, Size)) { + InlinedContext.getMutableFrame(InlinedContext.getNumberOfFrames() - 1) + ->FunctionName = FunctionName; + } + } + + return InlinedContext; +} + +DIGlobal SymbolizableObjectFile::symbolizeData(uint64_t ModuleOffset) const { + DIGlobal Res; + getNameFromSymbolTable(SymbolRef::ST_Data, ModuleOffset, Res.Name, Res.Start, + Res.Size); + return Res; +} + +} // namespace symbolize +} // namespace llvm + |