|  | //===- DWARFUnit.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 | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "llvm/DebugInfo/DWARF/DWARFUnit.h" | 
|  | #include "llvm/ADT/SmallString.h" | 
|  | #include "llvm/ADT/StringRef.h" | 
|  | #include "llvm/BinaryFormat/Dwarf.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFContext.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFDie.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFExpression.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFListTable.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFObject.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFSection.h" | 
|  | #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h" | 
|  | #include "llvm/Object/ObjectFile.h" | 
|  | #include "llvm/Support/DataExtractor.h" | 
|  | #include "llvm/Support/Errc.h" | 
|  | #include "llvm/Support/Path.h" | 
|  | #include <algorithm> | 
|  | #include <cassert> | 
|  | #include <cstddef> | 
|  | #include <cstdint> | 
|  | #include <utility> | 
|  | #include <vector> | 
|  |  | 
|  | using namespace llvm; | 
|  | using namespace dwarf; | 
|  |  | 
|  | void DWARFUnitVector::addUnitsForSection(DWARFContext &C, | 
|  | const DWARFSection &Section, | 
|  | DWARFSectionKind SectionKind) { | 
|  | const DWARFObject &D = C.getDWARFObj(); | 
|  | addUnitsImpl(C, D, Section, C.getDebugAbbrev(), &D.getRangesSection(), | 
|  | &D.getLocSection(), D.getStrSection(), | 
|  | D.getStrOffsetsSection(), &D.getAddrSection(), | 
|  | D.getLineSection(), D.isLittleEndian(), false, false, | 
|  | SectionKind); | 
|  | } | 
|  |  | 
|  | void DWARFUnitVector::addUnitsForDWOSection(DWARFContext &C, | 
|  | const DWARFSection &DWOSection, | 
|  | DWARFSectionKind SectionKind, | 
|  | bool Lazy) { | 
|  | const DWARFObject &D = C.getDWARFObj(); | 
|  | addUnitsImpl(C, D, DWOSection, C.getDebugAbbrevDWO(), &D.getRangesDWOSection(), | 
|  | &D.getLocDWOSection(), D.getStrDWOSection(), | 
|  | D.getStrOffsetsDWOSection(), &D.getAddrSection(), | 
|  | D.getLineDWOSection(), C.isLittleEndian(), true, Lazy, | 
|  | SectionKind); | 
|  | } | 
|  |  | 
|  | void DWARFUnitVector::addUnitsImpl( | 
|  | DWARFContext &Context, const DWARFObject &Obj, const DWARFSection &Section, | 
|  | const DWARFDebugAbbrev *DA, const DWARFSection *RS, | 
|  | const DWARFSection *LocSection, StringRef SS, const DWARFSection &SOS, | 
|  | const DWARFSection *AOS, const DWARFSection &LS, bool LE, bool IsDWO, | 
|  | bool Lazy, DWARFSectionKind SectionKind) { | 
|  | DWARFDataExtractor Data(Obj, Section, LE, 0); | 
|  | // Lazy initialization of Parser, now that we have all section info. | 
|  | if (!Parser) { | 
|  | Parser = [=, &Context, &Obj, &Section, &SOS, | 
|  | &LS](uint64_t Offset, DWARFSectionKind SectionKind, | 
|  | const DWARFSection *CurSection, | 
|  | const DWARFUnitIndex::Entry *IndexEntry) | 
|  | -> std::unique_ptr<DWARFUnit> { | 
|  | const DWARFSection &InfoSection = CurSection ? *CurSection : Section; | 
|  | DWARFDataExtractor Data(Obj, InfoSection, LE, 0); | 
|  | if (!Data.isValidOffset(Offset)) | 
|  | return nullptr; | 
|  | DWARFUnitHeader Header; | 
|  | if (!Header.extract(Context, Data, &Offset, SectionKind)) | 
|  | return nullptr; | 
|  | if (!IndexEntry && IsDWO) { | 
|  | const DWARFUnitIndex &Index = getDWARFUnitIndex( | 
|  | Context, Header.isTypeUnit() ? DW_SECT_EXT_TYPES : DW_SECT_INFO); | 
|  | if (Index) { | 
|  | if (Header.isTypeUnit()) | 
|  | IndexEntry = Index.getFromHash(Header.getTypeHash()); | 
|  | else if (auto DWOId = Header.getDWOId()) | 
|  | IndexEntry = Index.getFromHash(*DWOId); | 
|  | } | 
|  | if (!IndexEntry) | 
|  | IndexEntry = Index.getFromOffset(Header.getOffset()); | 
|  | } | 
|  | if (IndexEntry && !Header.applyIndexEntry(IndexEntry)) | 
|  | return nullptr; | 
|  | std::unique_ptr<DWARFUnit> U; | 
|  | if (Header.isTypeUnit()) | 
|  | U = std::make_unique<DWARFTypeUnit>(Context, InfoSection, Header, DA, | 
|  | RS, LocSection, SS, SOS, AOS, LS, | 
|  | LE, IsDWO, *this); | 
|  | else | 
|  | U = std::make_unique<DWARFCompileUnit>(Context, InfoSection, Header, | 
|  | DA, RS, LocSection, SS, SOS, | 
|  | AOS, LS, LE, IsDWO, *this); | 
|  | return U; | 
|  | }; | 
|  | } | 
|  | if (Lazy) | 
|  | return; | 
|  | // Find a reasonable insertion point within the vector.  We skip over | 
|  | // (a) units from a different section, (b) units from the same section | 
|  | // but with lower offset-within-section.  This keeps units in order | 
|  | // within a section, although not necessarily within the object file, | 
|  | // even if we do lazy parsing. | 
|  | auto I = this->begin(); | 
|  | uint64_t Offset = 0; | 
|  | while (Data.isValidOffset(Offset)) { | 
|  | if (I != this->end() && | 
|  | (&(*I)->getInfoSection() != &Section || (*I)->getOffset() == Offset)) { | 
|  | ++I; | 
|  | continue; | 
|  | } | 
|  | auto U = Parser(Offset, SectionKind, &Section, nullptr); | 
|  | // If parsing failed, we're done with this section. | 
|  | if (!U) | 
|  | break; | 
|  | Offset = U->getNextUnitOffset(); | 
|  | I = std::next(this->insert(I, std::move(U))); | 
|  | } | 
|  | } | 
|  |  | 
|  | DWARFUnit *DWARFUnitVector::addUnit(std::unique_ptr<DWARFUnit> Unit) { | 
|  | auto I = std::upper_bound(begin(), end(), Unit, | 
|  | [](const std::unique_ptr<DWARFUnit> &LHS, | 
|  | const std::unique_ptr<DWARFUnit> &RHS) { | 
|  | return LHS->getOffset() < RHS->getOffset(); | 
|  | }); | 
|  | return this->insert(I, std::move(Unit))->get(); | 
|  | } | 
|  |  | 
|  | DWARFUnit *DWARFUnitVector::getUnitForOffset(uint64_t Offset) const { | 
|  | auto end = begin() + getNumInfoUnits(); | 
|  | auto *CU = | 
|  | std::upper_bound(begin(), end, Offset, | 
|  | [](uint64_t LHS, const std::unique_ptr<DWARFUnit> &RHS) { | 
|  | return LHS < RHS->getNextUnitOffset(); | 
|  | }); | 
|  | if (CU != end && (*CU)->getOffset() <= Offset) | 
|  | return CU->get(); | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | DWARFUnit * | 
|  | DWARFUnitVector::getUnitForIndexEntry(const DWARFUnitIndex::Entry &E) { | 
|  | const auto *CUOff = E.getContribution(DW_SECT_INFO); | 
|  | if (!CUOff) | 
|  | return nullptr; | 
|  |  | 
|  | auto Offset = CUOff->Offset; | 
|  | auto end = begin() + getNumInfoUnits(); | 
|  |  | 
|  | auto *CU = | 
|  | std::upper_bound(begin(), end, CUOff->Offset, | 
|  | [](uint64_t LHS, const std::unique_ptr<DWARFUnit> &RHS) { | 
|  | return LHS < RHS->getNextUnitOffset(); | 
|  | }); | 
|  | if (CU != end && (*CU)->getOffset() <= Offset) | 
|  | return CU->get(); | 
|  |  | 
|  | if (!Parser) | 
|  | return nullptr; | 
|  |  | 
|  | auto U = Parser(Offset, DW_SECT_INFO, nullptr, &E); | 
|  | if (!U) | 
|  | U = nullptr; | 
|  |  | 
|  | auto *NewCU = U.get(); | 
|  | this->insert(CU, std::move(U)); | 
|  | ++NumInfoUnits; | 
|  | return NewCU; | 
|  | } | 
|  |  | 
|  | DWARFUnit::DWARFUnit(DWARFContext &DC, const DWARFSection &Section, | 
|  | const DWARFUnitHeader &Header, const DWARFDebugAbbrev *DA, | 
|  | const DWARFSection *RS, const DWARFSection *LocSection, | 
|  | StringRef SS, const DWARFSection &SOS, | 
|  | const DWARFSection *AOS, const DWARFSection &LS, bool LE, | 
|  | bool IsDWO, const DWARFUnitVector &UnitVector) | 
|  | : Context(DC), InfoSection(Section), Header(Header), Abbrev(DA), | 
|  | RangeSection(RS), LineSection(LS), StringSection(SS), | 
|  | StringOffsetSection(SOS), AddrOffsetSection(AOS), isLittleEndian(LE), | 
|  | IsDWO(IsDWO), UnitVector(UnitVector) { | 
|  | clear(); | 
|  | } | 
|  |  | 
|  | DWARFUnit::~DWARFUnit() = default; | 
|  |  | 
|  | DWARFDataExtractor DWARFUnit::getDebugInfoExtractor() const { | 
|  | return DWARFDataExtractor(Context.getDWARFObj(), InfoSection, isLittleEndian, | 
|  | getAddressByteSize()); | 
|  | } | 
|  |  | 
|  | Optional<object::SectionedAddress> | 
|  | DWARFUnit::getAddrOffsetSectionItem(uint32_t Index) const { | 
|  | if (!AddrOffsetSectionBase) { | 
|  | auto R = Context.info_section_units(); | 
|  | // Surprising if a DWO file has more than one skeleton unit in it - this | 
|  | // probably shouldn't be valid, but if a use case is found, here's where to | 
|  | // support it (probably have to linearly search for the matching skeleton CU | 
|  | // here) | 
|  | if (IsDWO && hasSingleElement(R)) | 
|  | return (*R.begin())->getAddrOffsetSectionItem(Index); | 
|  |  | 
|  | return None; | 
|  | } | 
|  |  | 
|  | uint64_t Offset = *AddrOffsetSectionBase + Index * getAddressByteSize(); | 
|  | if (AddrOffsetSection->Data.size() < Offset + getAddressByteSize()) | 
|  | return None; | 
|  | DWARFDataExtractor DA(Context.getDWARFObj(), *AddrOffsetSection, | 
|  | isLittleEndian, getAddressByteSize()); | 
|  | uint64_t Section; | 
|  | uint64_t Address = DA.getRelocatedAddress(&Offset, &Section); | 
|  | return {{Address, Section}}; | 
|  | } | 
|  |  | 
|  | Expected<uint64_t> DWARFUnit::getStringOffsetSectionItem(uint32_t Index) const { | 
|  | if (!StringOffsetsTableContribution) | 
|  | return make_error<StringError>( | 
|  | "DW_FORM_strx used without a valid string offsets table", | 
|  | inconvertibleErrorCode()); | 
|  | unsigned ItemSize = getDwarfStringOffsetsByteSize(); | 
|  | uint64_t Offset = getStringOffsetsBase() + Index * ItemSize; | 
|  | if (StringOffsetSection.Data.size() < Offset + ItemSize) | 
|  | return make_error<StringError>("DW_FORM_strx uses index " + Twine(Index) + | 
|  | ", which is too large", | 
|  | inconvertibleErrorCode()); | 
|  | DWARFDataExtractor DA(Context.getDWARFObj(), StringOffsetSection, | 
|  | isLittleEndian, 0); | 
|  | return DA.getRelocatedValue(ItemSize, &Offset); | 
|  | } | 
|  |  | 
|  | bool DWARFUnitHeader::extract(DWARFContext &Context, | 
|  | const DWARFDataExtractor &debug_info, | 
|  | uint64_t *offset_ptr, | 
|  | DWARFSectionKind SectionKind) { | 
|  | Offset = *offset_ptr; | 
|  | Error Err = Error::success(); | 
|  | IndexEntry = nullptr; | 
|  | std::tie(Length, FormParams.Format) = | 
|  | debug_info.getInitialLength(offset_ptr, &Err); | 
|  | FormParams.Version = debug_info.getU16(offset_ptr, &Err); | 
|  | if (FormParams.Version >= 5) { | 
|  | UnitType = debug_info.getU8(offset_ptr, &Err); | 
|  | FormParams.AddrSize = debug_info.getU8(offset_ptr, &Err); | 
|  | AbbrOffset = debug_info.getRelocatedValue( | 
|  | FormParams.getDwarfOffsetByteSize(), offset_ptr, nullptr, &Err); | 
|  | } else { | 
|  | AbbrOffset = debug_info.getRelocatedValue( | 
|  | FormParams.getDwarfOffsetByteSize(), offset_ptr, nullptr, &Err); | 
|  | FormParams.AddrSize = debug_info.getU8(offset_ptr, &Err); | 
|  | // Fake a unit type based on the section type.  This isn't perfect, | 
|  | // but distinguishing compile and type units is generally enough. | 
|  | if (SectionKind == DW_SECT_EXT_TYPES) | 
|  | UnitType = DW_UT_type; | 
|  | else | 
|  | UnitType = DW_UT_compile; | 
|  | } | 
|  | if (isTypeUnit()) { | 
|  | TypeHash = debug_info.getU64(offset_ptr, &Err); | 
|  | TypeOffset = debug_info.getUnsigned( | 
|  | offset_ptr, FormParams.getDwarfOffsetByteSize(), &Err); | 
|  | } else if (UnitType == DW_UT_split_compile || UnitType == DW_UT_skeleton) | 
|  | DWOId = debug_info.getU64(offset_ptr, &Err); | 
|  |  | 
|  | if (Err) { | 
|  | Context.getWarningHandler()(joinErrors( | 
|  | createStringError( | 
|  | errc::invalid_argument, | 
|  | "DWARF unit at 0x%8.8" PRIx64 " cannot be parsed:", Offset), | 
|  | std::move(Err))); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // Header fields all parsed, capture the size of this unit header. | 
|  | assert(*offset_ptr - Offset <= 255 && "unexpected header size"); | 
|  | Size = uint8_t(*offset_ptr - Offset); | 
|  | uint64_t NextCUOffset = Offset + getUnitLengthFieldByteSize() + getLength(); | 
|  |  | 
|  | if (!debug_info.isValidOffset(getNextUnitOffset() - 1)) { | 
|  | Context.getWarningHandler()( | 
|  | createStringError(errc::invalid_argument, | 
|  | "DWARF unit from offset 0x%8.8" PRIx64 " incl. " | 
|  | "to offset  0x%8.8" PRIx64 " excl. " | 
|  | "extends past section size 0x%8.8zx", | 
|  | Offset, NextCUOffset, debug_info.size())); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (!DWARFContext::isSupportedVersion(getVersion())) { | 
|  | Context.getWarningHandler()(createStringError( | 
|  | errc::invalid_argument, | 
|  | "DWARF unit at offset 0x%8.8" PRIx64 " " | 
|  | "has unsupported version %" PRIu16 ", supported are 2-%u", | 
|  | Offset, getVersion(), DWARFContext::getMaxSupportedVersion())); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // Type offset is unit-relative; should be after the header and before | 
|  | // the end of the current unit. | 
|  | if (isTypeUnit() && TypeOffset < Size) { | 
|  | Context.getWarningHandler()( | 
|  | createStringError(errc::invalid_argument, | 
|  | "DWARF type unit at offset " | 
|  | "0x%8.8" PRIx64 " " | 
|  | "has its relocated type_offset 0x%8.8" PRIx64 " " | 
|  | "pointing inside the header", | 
|  | Offset, Offset + TypeOffset)); | 
|  | return false; | 
|  | } | 
|  | if (isTypeUnit() && | 
|  | TypeOffset >= getUnitLengthFieldByteSize() + getLength()) { | 
|  | Context.getWarningHandler()(createStringError( | 
|  | errc::invalid_argument, | 
|  | "DWARF type unit from offset 0x%8.8" PRIx64 " incl. " | 
|  | "to offset 0x%8.8" PRIx64 " excl. has its " | 
|  | "relocated type_offset 0x%8.8" PRIx64 " pointing past the unit end", | 
|  | Offset, NextCUOffset, Offset + TypeOffset)); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (Error SizeErr = DWARFContext::checkAddressSizeSupported( | 
|  | getAddressByteSize(), errc::invalid_argument, | 
|  | "DWARF unit at offset 0x%8.8" PRIx64, Offset)) { | 
|  | Context.getWarningHandler()(std::move(SizeErr)); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // Keep track of the highest DWARF version we encounter across all units. | 
|  | Context.setMaxVersionIfGreater(getVersion()); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool DWARFUnitHeader::applyIndexEntry(const DWARFUnitIndex::Entry *Entry) { | 
|  | assert(Entry); | 
|  | assert(!IndexEntry); | 
|  | IndexEntry = Entry; | 
|  | if (AbbrOffset) | 
|  | return false; | 
|  | auto *UnitContrib = IndexEntry->getContribution(); | 
|  | if (!UnitContrib || | 
|  | UnitContrib->Length != (getLength() + getUnitLengthFieldByteSize())) | 
|  | return false; | 
|  | auto *AbbrEntry = IndexEntry->getContribution(DW_SECT_ABBREV); | 
|  | if (!AbbrEntry) | 
|  | return false; | 
|  | AbbrOffset = AbbrEntry->Offset; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | Error DWARFUnit::extractRangeList(uint64_t RangeListOffset, | 
|  | DWARFDebugRangeList &RangeList) const { | 
|  | // Require that compile unit is extracted. | 
|  | assert(!DieArray.empty()); | 
|  | DWARFDataExtractor RangesData(Context.getDWARFObj(), *RangeSection, | 
|  | isLittleEndian, getAddressByteSize()); | 
|  | uint64_t ActualRangeListOffset = RangeSectionBase + RangeListOffset; | 
|  | return RangeList.extract(RangesData, &ActualRangeListOffset); | 
|  | } | 
|  |  | 
|  | void DWARFUnit::clear() { | 
|  | Abbrevs = nullptr; | 
|  | BaseAddr.reset(); | 
|  | RangeSectionBase = 0; | 
|  | LocSectionBase = 0; | 
|  | AddrOffsetSectionBase = None; | 
|  | SU = nullptr; | 
|  | clearDIEs(false); | 
|  | AddrDieMap.clear(); | 
|  | if (DWO) | 
|  | DWO->clear(); | 
|  | DWO.reset(); | 
|  | } | 
|  |  | 
|  | const char *DWARFUnit::getCompilationDir() { | 
|  | return dwarf::toString(getUnitDIE().find(DW_AT_comp_dir), nullptr); | 
|  | } | 
|  |  | 
|  | void DWARFUnit::extractDIEsToVector( | 
|  | bool AppendCUDie, bool AppendNonCUDies, | 
|  | std::vector<DWARFDebugInfoEntry> &Dies) const { | 
|  | if (!AppendCUDie && !AppendNonCUDies) | 
|  | return; | 
|  |  | 
|  | // Set the offset to that of the first DIE and calculate the start of the | 
|  | // next compilation unit header. | 
|  | uint64_t DIEOffset = getOffset() + getHeaderSize(); | 
|  | uint64_t NextCUOffset = getNextUnitOffset(); | 
|  | DWARFDebugInfoEntry DIE; | 
|  | DWARFDataExtractor DebugInfoData = getDebugInfoExtractor(); | 
|  | // The end offset has been already checked by DWARFUnitHeader::extract. | 
|  | assert(DebugInfoData.isValidOffset(NextCUOffset - 1)); | 
|  | std::vector<uint32_t> Parents; | 
|  | std::vector<uint32_t> PrevSiblings; | 
|  | bool IsCUDie = true; | 
|  |  | 
|  | assert( | 
|  | ((AppendCUDie && Dies.empty()) || (!AppendCUDie && Dies.size() == 1)) && | 
|  | "Dies array is not empty"); | 
|  |  | 
|  | // Fill Parents and Siblings stacks with initial value. | 
|  | Parents.push_back(UINT32_MAX); | 
|  | if (!AppendCUDie) | 
|  | Parents.push_back(0); | 
|  | PrevSiblings.push_back(0); | 
|  |  | 
|  | // Start to extract dies. | 
|  | do { | 
|  | assert(Parents.size() > 0 && "Empty parents stack"); | 
|  | assert((Parents.back() == UINT32_MAX || Parents.back() <= Dies.size()) && | 
|  | "Wrong parent index"); | 
|  |  | 
|  | // Extract die. Stop if any error occurred. | 
|  | if (!DIE.extractFast(*this, &DIEOffset, DebugInfoData, NextCUOffset, | 
|  | Parents.back())) | 
|  | break; | 
|  |  | 
|  | // If previous sibling is remembered then update it`s SiblingIdx field. | 
|  | if (PrevSiblings.back() > 0) { | 
|  | assert(PrevSiblings.back() < Dies.size() && | 
|  | "Previous sibling index is out of Dies boundaries"); | 
|  | Dies[PrevSiblings.back()].setSiblingIdx(Dies.size()); | 
|  | } | 
|  |  | 
|  | // Store die into the Dies vector. | 
|  | if (IsCUDie) { | 
|  | if (AppendCUDie) | 
|  | Dies.push_back(DIE); | 
|  | if (!AppendNonCUDies) | 
|  | break; | 
|  | // The average bytes per DIE entry has been seen to be | 
|  | // around 14-20 so let's pre-reserve the needed memory for | 
|  | // our DIE entries accordingly. | 
|  | Dies.reserve(Dies.size() + getDebugInfoSize() / 14); | 
|  | } else { | 
|  | // Remember last previous sibling. | 
|  | PrevSiblings.back() = Dies.size(); | 
|  |  | 
|  | Dies.push_back(DIE); | 
|  | } | 
|  |  | 
|  | // Check for new children scope. | 
|  | if (const DWARFAbbreviationDeclaration *AbbrDecl = | 
|  | DIE.getAbbreviationDeclarationPtr()) { | 
|  | if (AbbrDecl->hasChildren()) { | 
|  | if (AppendCUDie || !IsCUDie) { | 
|  | assert(Dies.size() > 0 && "Dies does not contain any die"); | 
|  | Parents.push_back(Dies.size() - 1); | 
|  | PrevSiblings.push_back(0); | 
|  | } | 
|  | } else if (IsCUDie) | 
|  | // Stop if we have single compile unit die w/o children. | 
|  | break; | 
|  | } else { | 
|  | // NULL DIE: finishes current children scope. | 
|  | Parents.pop_back(); | 
|  | PrevSiblings.pop_back(); | 
|  | } | 
|  |  | 
|  | if (IsCUDie) | 
|  | IsCUDie = false; | 
|  |  | 
|  | // Stop when compile unit die is removed from the parents stack. | 
|  | } while (Parents.size() > 1); | 
|  | } | 
|  |  | 
|  | void DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) { | 
|  | if (Error e = tryExtractDIEsIfNeeded(CUDieOnly)) | 
|  | Context.getRecoverableErrorHandler()(std::move(e)); | 
|  | } | 
|  |  | 
|  | Error DWARFUnit::tryExtractDIEsIfNeeded(bool CUDieOnly) { | 
|  | if ((CUDieOnly && !DieArray.empty()) || | 
|  | DieArray.size() > 1) | 
|  | return Error::success(); // Already parsed. | 
|  |  | 
|  | bool HasCUDie = !DieArray.empty(); | 
|  | extractDIEsToVector(!HasCUDie, !CUDieOnly, DieArray); | 
|  |  | 
|  | if (DieArray.empty()) | 
|  | return Error::success(); | 
|  |  | 
|  | // If CU DIE was just parsed, copy several attribute values from it. | 
|  | if (HasCUDie) | 
|  | return Error::success(); | 
|  |  | 
|  | DWARFDie UnitDie(this, &DieArray[0]); | 
|  | if (Optional<uint64_t> DWOId = toUnsigned(UnitDie.find(DW_AT_GNU_dwo_id))) | 
|  | Header.setDWOId(*DWOId); | 
|  | if (!IsDWO) { | 
|  | assert(AddrOffsetSectionBase == None); | 
|  | assert(RangeSectionBase == 0); | 
|  | assert(LocSectionBase == 0); | 
|  | AddrOffsetSectionBase = toSectionOffset(UnitDie.find(DW_AT_addr_base)); | 
|  | if (!AddrOffsetSectionBase) | 
|  | AddrOffsetSectionBase = | 
|  | toSectionOffset(UnitDie.find(DW_AT_GNU_addr_base)); | 
|  | RangeSectionBase = toSectionOffset(UnitDie.find(DW_AT_rnglists_base), 0); | 
|  | LocSectionBase = toSectionOffset(UnitDie.find(DW_AT_loclists_base), 0); | 
|  | } | 
|  |  | 
|  | // In general, in DWARF v5 and beyond we derive the start of the unit's | 
|  | // contribution to the string offsets table from the unit DIE's | 
|  | // DW_AT_str_offsets_base attribute. Split DWARF units do not use this | 
|  | // attribute, so we assume that there is a contribution to the string | 
|  | // offsets table starting at offset 0 of the debug_str_offsets.dwo section. | 
|  | // In both cases we need to determine the format of the contribution, | 
|  | // which may differ from the unit's format. | 
|  | DWARFDataExtractor DA(Context.getDWARFObj(), StringOffsetSection, | 
|  | isLittleEndian, 0); | 
|  | if (IsDWO || getVersion() >= 5) { | 
|  | auto StringOffsetOrError = | 
|  | IsDWO ? determineStringOffsetsTableContributionDWO(DA) | 
|  | : determineStringOffsetsTableContribution(DA); | 
|  | if (!StringOffsetOrError) | 
|  | return createStringError(errc::invalid_argument, | 
|  | "invalid reference to or invalid content in " | 
|  | ".debug_str_offsets[.dwo]: " + | 
|  | toString(StringOffsetOrError.takeError())); | 
|  |  | 
|  | StringOffsetsTableContribution = *StringOffsetOrError; | 
|  | } | 
|  |  | 
|  | // DWARF v5 uses the .debug_rnglists and .debug_rnglists.dwo sections to | 
|  | // describe address ranges. | 
|  | if (getVersion() >= 5) { | 
|  | // In case of DWP, the base offset from the index has to be added. | 
|  | if (IsDWO) { | 
|  | uint64_t ContributionBaseOffset = 0; | 
|  | if (auto *IndexEntry = Header.getIndexEntry()) | 
|  | if (auto *Contrib = IndexEntry->getContribution(DW_SECT_RNGLISTS)) | 
|  | ContributionBaseOffset = Contrib->Offset; | 
|  | setRangesSection( | 
|  | &Context.getDWARFObj().getRnglistsDWOSection(), | 
|  | ContributionBaseOffset + | 
|  | DWARFListTableHeader::getHeaderSize(Header.getFormat())); | 
|  | } else | 
|  | setRangesSection(&Context.getDWARFObj().getRnglistsSection(), | 
|  | toSectionOffset(UnitDie.find(DW_AT_rnglists_base), | 
|  | DWARFListTableHeader::getHeaderSize( | 
|  | Header.getFormat()))); | 
|  | } | 
|  |  | 
|  | if (IsDWO) { | 
|  | // If we are reading a package file, we need to adjust the location list | 
|  | // data based on the index entries. | 
|  | StringRef Data = Header.getVersion() >= 5 | 
|  | ? Context.getDWARFObj().getLoclistsDWOSection().Data | 
|  | : Context.getDWARFObj().getLocDWOSection().Data; | 
|  | if (auto *IndexEntry = Header.getIndexEntry()) | 
|  | if (const auto *C = IndexEntry->getContribution( | 
|  | Header.getVersion() >= 5 ? DW_SECT_LOCLISTS : DW_SECT_EXT_LOC)) | 
|  | Data = Data.substr(C->Offset, C->Length); | 
|  |  | 
|  | DWARFDataExtractor DWARFData(Data, isLittleEndian, getAddressByteSize()); | 
|  | LocTable = | 
|  | std::make_unique<DWARFDebugLoclists>(DWARFData, Header.getVersion()); | 
|  | LocSectionBase = DWARFListTableHeader::getHeaderSize(Header.getFormat()); | 
|  | } else if (getVersion() >= 5) { | 
|  | LocTable = std::make_unique<DWARFDebugLoclists>( | 
|  | DWARFDataExtractor(Context.getDWARFObj(), | 
|  | Context.getDWARFObj().getLoclistsSection(), | 
|  | isLittleEndian, getAddressByteSize()), | 
|  | getVersion()); | 
|  | } else { | 
|  | LocTable = std::make_unique<DWARFDebugLoc>(DWARFDataExtractor( | 
|  | Context.getDWARFObj(), Context.getDWARFObj().getLocSection(), | 
|  | isLittleEndian, getAddressByteSize())); | 
|  | } | 
|  |  | 
|  | // Don't fall back to DW_AT_GNU_ranges_base: it should be ignored for | 
|  | // skeleton CU DIE, so that DWARF users not aware of it are not broken. | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | bool DWARFUnit::parseDWO() { | 
|  | if (IsDWO) | 
|  | return false; | 
|  | if (DWO.get()) | 
|  | return false; | 
|  | DWARFDie UnitDie = getUnitDIE(); | 
|  | if (!UnitDie) | 
|  | return false; | 
|  | auto DWOFileName = getVersion() >= 5 | 
|  | ? dwarf::toString(UnitDie.find(DW_AT_dwo_name)) | 
|  | : dwarf::toString(UnitDie.find(DW_AT_GNU_dwo_name)); | 
|  | if (!DWOFileName) | 
|  | return false; | 
|  | auto CompilationDir = dwarf::toString(UnitDie.find(DW_AT_comp_dir)); | 
|  | SmallString<16> AbsolutePath; | 
|  | if (sys::path::is_relative(*DWOFileName) && CompilationDir && | 
|  | *CompilationDir) { | 
|  | sys::path::append(AbsolutePath, *CompilationDir); | 
|  | } | 
|  | sys::path::append(AbsolutePath, *DWOFileName); | 
|  | auto DWOId = getDWOId(); | 
|  | if (!DWOId) | 
|  | return false; | 
|  | auto DWOContext = Context.getDWOContext(AbsolutePath); | 
|  | if (!DWOContext) | 
|  | return false; | 
|  |  | 
|  | DWARFCompileUnit *DWOCU = DWOContext->getDWOCompileUnitForHash(*DWOId); | 
|  | if (!DWOCU) | 
|  | return false; | 
|  | DWO = std::shared_ptr<DWARFCompileUnit>(std::move(DWOContext), DWOCU); | 
|  | DWO->setSkeletonUnit(this); | 
|  | // Share .debug_addr and .debug_ranges section with compile unit in .dwo | 
|  | if (AddrOffsetSectionBase) | 
|  | DWO->setAddrOffsetSection(AddrOffsetSection, *AddrOffsetSectionBase); | 
|  | if (getVersion() == 4) { | 
|  | auto DWORangesBase = UnitDie.getRangesBaseAttribute(); | 
|  | DWO->setRangesSection(RangeSection, DWORangesBase.value_or(0)); | 
|  | } | 
|  |  | 
|  | return true; | 
|  | } | 
|  |  | 
|  | void DWARFUnit::clearDIEs(bool KeepCUDie) { | 
|  | // Do not use resize() + shrink_to_fit() to free memory occupied by dies. | 
|  | // shrink_to_fit() is a *non-binding* request to reduce capacity() to size(). | 
|  | // It depends on the implementation whether the request is fulfilled. | 
|  | // Create a new vector with a small capacity and assign it to the DieArray to | 
|  | // have previous contents freed. | 
|  | DieArray = (KeepCUDie && !DieArray.empty()) | 
|  | ? std::vector<DWARFDebugInfoEntry>({DieArray[0]}) | 
|  | : std::vector<DWARFDebugInfoEntry>(); | 
|  | } | 
|  |  | 
|  | Expected<DWARFAddressRangesVector> | 
|  | DWARFUnit::findRnglistFromOffset(uint64_t Offset) { | 
|  | if (getVersion() <= 4) { | 
|  | DWARFDebugRangeList RangeList; | 
|  | if (Error E = extractRangeList(Offset, RangeList)) | 
|  | return std::move(E); | 
|  | return RangeList.getAbsoluteRanges(getBaseAddress()); | 
|  | } | 
|  | DWARFDataExtractor RangesData(Context.getDWARFObj(), *RangeSection, | 
|  | isLittleEndian, Header.getAddressByteSize()); | 
|  | DWARFDebugRnglistTable RnglistTable; | 
|  | auto RangeListOrError = RnglistTable.findList(RangesData, Offset); | 
|  | if (RangeListOrError) | 
|  | return RangeListOrError.get().getAbsoluteRanges(getBaseAddress(), *this); | 
|  | return RangeListOrError.takeError(); | 
|  | } | 
|  |  | 
|  | Expected<DWARFAddressRangesVector> | 
|  | DWARFUnit::findRnglistFromIndex(uint32_t Index) { | 
|  | if (auto Offset = getRnglistOffset(Index)) | 
|  | return findRnglistFromOffset(*Offset); | 
|  |  | 
|  | return createStringError(errc::invalid_argument, | 
|  | "invalid range list table index %d (possibly " | 
|  | "missing the entire range list table)", | 
|  | Index); | 
|  | } | 
|  |  | 
|  | Expected<DWARFAddressRangesVector> DWARFUnit::collectAddressRanges() { | 
|  | DWARFDie UnitDie = getUnitDIE(); | 
|  | if (!UnitDie) | 
|  | return createStringError(errc::invalid_argument, "No unit DIE"); | 
|  |  | 
|  | // First, check if unit DIE describes address ranges for the whole unit. | 
|  | auto CUDIERangesOrError = UnitDie.getAddressRanges(); | 
|  | if (!CUDIERangesOrError) | 
|  | return createStringError(errc::invalid_argument, | 
|  | "decoding address ranges: %s", | 
|  | toString(CUDIERangesOrError.takeError()).c_str()); | 
|  | return *CUDIERangesOrError; | 
|  | } | 
|  |  | 
|  | Expected<DWARFLocationExpressionsVector> | 
|  | DWARFUnit::findLoclistFromOffset(uint64_t Offset) { | 
|  | DWARFLocationExpressionsVector Result; | 
|  |  | 
|  | Error InterpretationError = Error::success(); | 
|  |  | 
|  | Error ParseError = getLocationTable().visitAbsoluteLocationList( | 
|  | Offset, getBaseAddress(), | 
|  | [this](uint32_t Index) { return getAddrOffsetSectionItem(Index); }, | 
|  | [&](Expected<DWARFLocationExpression> L) { | 
|  | if (L) | 
|  | Result.push_back(std::move(*L)); | 
|  | else | 
|  | InterpretationError = | 
|  | joinErrors(L.takeError(), std::move(InterpretationError)); | 
|  | return !InterpretationError; | 
|  | }); | 
|  |  | 
|  | if (ParseError || InterpretationError) | 
|  | return joinErrors(std::move(ParseError), std::move(InterpretationError)); | 
|  |  | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | void DWARFUnit::updateAddressDieMap(DWARFDie Die) { | 
|  | if (Die.isSubroutineDIE()) { | 
|  | auto DIERangesOrError = Die.getAddressRanges(); | 
|  | if (DIERangesOrError) { | 
|  | for (const auto &R : DIERangesOrError.get()) { | 
|  | // Ignore 0-sized ranges. | 
|  | if (R.LowPC == R.HighPC) | 
|  | continue; | 
|  | auto B = AddrDieMap.upper_bound(R.LowPC); | 
|  | if (B != AddrDieMap.begin() && R.LowPC < (--B)->second.first) { | 
|  | // The range is a sub-range of existing ranges, we need to split the | 
|  | // existing range. | 
|  | if (R.HighPC < B->second.first) | 
|  | AddrDieMap[R.HighPC] = B->second; | 
|  | if (R.LowPC > B->first) | 
|  | AddrDieMap[B->first].first = R.LowPC; | 
|  | } | 
|  | AddrDieMap[R.LowPC] = std::make_pair(R.HighPC, Die); | 
|  | } | 
|  | } else | 
|  | llvm::consumeError(DIERangesOrError.takeError()); | 
|  | } | 
|  | // Parent DIEs are added to the AddrDieMap prior to the Children DIEs to | 
|  | // simplify the logic to update AddrDieMap. The child's range will always | 
|  | // be equal or smaller than the parent's range. With this assumption, when | 
|  | // adding one range into the map, it will at most split a range into 3 | 
|  | // sub-ranges. | 
|  | for (DWARFDie Child = Die.getFirstChild(); Child; Child = Child.getSibling()) | 
|  | updateAddressDieMap(Child); | 
|  | } | 
|  |  | 
|  | DWARFDie DWARFUnit::getSubroutineForAddress(uint64_t Address) { | 
|  | extractDIEsIfNeeded(false); | 
|  | if (AddrDieMap.empty()) | 
|  | updateAddressDieMap(getUnitDIE()); | 
|  | auto R = AddrDieMap.upper_bound(Address); | 
|  | if (R == AddrDieMap.begin()) | 
|  | return DWARFDie(); | 
|  | // upper_bound's previous item contains Address. | 
|  | --R; | 
|  | if (Address >= R->second.first) | 
|  | return DWARFDie(); | 
|  | return R->second.second; | 
|  | } | 
|  |  | 
|  | void DWARFUnit::updateVariableDieMap(DWARFDie Die) { | 
|  | for (DWARFDie Child : Die) { | 
|  | if (isType(Child.getTag())) | 
|  | continue; | 
|  | updateVariableDieMap(Child); | 
|  | } | 
|  |  | 
|  | if (Die.getTag() != DW_TAG_variable) | 
|  | return; | 
|  |  | 
|  | Expected<DWARFLocationExpressionsVector> Locations = | 
|  | Die.getLocations(DW_AT_location); | 
|  | if (!Locations) { | 
|  | // Missing DW_AT_location is fine here. | 
|  | consumeError(Locations.takeError()); | 
|  | return; | 
|  | } | 
|  |  | 
|  | uint64_t Address = UINT64_MAX; | 
|  |  | 
|  | for (const DWARFLocationExpression &Location : *Locations) { | 
|  | uint8_t AddressSize = getAddressByteSize(); | 
|  | DataExtractor Data(Location.Expr, /*IsLittleEndian=*/true, AddressSize); | 
|  | DWARFExpression Expr(Data, AddressSize); | 
|  | auto It = Expr.begin(); | 
|  | if (It == Expr.end()) | 
|  | continue; | 
|  |  | 
|  | // Match exactly the main sequence used to describe global variables: | 
|  | // `DW_OP_addr[x] [+ DW_OP_plus_uconst]`. Currently, this is the sequence | 
|  | // that LLVM produces for DILocalVariables and DIGlobalVariables. If, in | 
|  | // future, the DWARF producer (`DwarfCompileUnit::addLocationAttribute()` is | 
|  | // a good starting point) is extended to use further expressions, this code | 
|  | // needs to be updated. | 
|  | uint64_t LocationAddr; | 
|  | if (It->getCode() == dwarf::DW_OP_addr) { | 
|  | LocationAddr = It->getRawOperand(0); | 
|  | } else if (It->getCode() == dwarf::DW_OP_addrx) { | 
|  | uint64_t DebugAddrOffset = It->getRawOperand(0); | 
|  | if (auto Pointer = getAddrOffsetSectionItem(DebugAddrOffset)) { | 
|  | LocationAddr = Pointer->Address; | 
|  | } | 
|  | } else { | 
|  | continue; | 
|  | } | 
|  |  | 
|  | // Read the optional 2nd operand, a DW_OP_plus_uconst. | 
|  | if (++It != Expr.end()) { | 
|  | if (It->getCode() != dwarf::DW_OP_plus_uconst) | 
|  | continue; | 
|  |  | 
|  | LocationAddr += It->getRawOperand(0); | 
|  |  | 
|  | // Probe for a 3rd operand, if it exists, bail. | 
|  | if (++It != Expr.end()) | 
|  | continue; | 
|  | } | 
|  |  | 
|  | Address = LocationAddr; | 
|  | break; | 
|  | } | 
|  |  | 
|  | // Get the size of the global variable. If all else fails (i.e. the global has | 
|  | // no type), then we use a size of one to still allow symbolization of the | 
|  | // exact address. | 
|  | uint64_t GVSize = 1; | 
|  | if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type)) | 
|  | if (Optional<uint64_t> Size = Die.getTypeSize(getAddressByteSize())) | 
|  | GVSize = *Size; | 
|  |  | 
|  | if (Address != UINT64_MAX) | 
|  | VariableDieMap[Address] = {Address + GVSize, Die}; | 
|  | } | 
|  |  | 
|  | DWARFDie DWARFUnit::getVariableForAddress(uint64_t Address) { | 
|  | extractDIEsIfNeeded(false); | 
|  |  | 
|  | auto RootDie = getUnitDIE(); | 
|  |  | 
|  | auto RootLookup = RootsParsedForVariables.insert(RootDie.getOffset()); | 
|  | if (RootLookup.second) | 
|  | updateVariableDieMap(RootDie); | 
|  |  | 
|  | auto R = VariableDieMap.upper_bound(Address); | 
|  | if (R == VariableDieMap.begin()) | 
|  | return DWARFDie(); | 
|  |  | 
|  | // upper_bound's previous item contains Address. | 
|  | --R; | 
|  | if (Address >= R->second.first) | 
|  | return DWARFDie(); | 
|  | return R->second.second; | 
|  | } | 
|  |  | 
|  | void | 
|  | DWARFUnit::getInlinedChainForAddress(uint64_t Address, | 
|  | SmallVectorImpl<DWARFDie> &InlinedChain) { | 
|  | assert(InlinedChain.empty()); | 
|  | // Try to look for subprogram DIEs in the DWO file. | 
|  | parseDWO(); | 
|  | // First, find the subroutine that contains the given address (the leaf | 
|  | // of inlined chain). | 
|  | DWARFDie SubroutineDIE = | 
|  | (DWO ? *DWO : *this).getSubroutineForAddress(Address); | 
|  |  | 
|  | while (SubroutineDIE) { | 
|  | if (SubroutineDIE.isSubprogramDIE()) { | 
|  | InlinedChain.push_back(SubroutineDIE); | 
|  | return; | 
|  | } | 
|  | if (SubroutineDIE.getTag() == DW_TAG_inlined_subroutine) | 
|  | InlinedChain.push_back(SubroutineDIE); | 
|  | SubroutineDIE  = SubroutineDIE.getParent(); | 
|  | } | 
|  | } | 
|  |  | 
|  | const DWARFUnitIndex &llvm::getDWARFUnitIndex(DWARFContext &Context, | 
|  | DWARFSectionKind Kind) { | 
|  | if (Kind == DW_SECT_INFO) | 
|  | return Context.getCUIndex(); | 
|  | assert(Kind == DW_SECT_EXT_TYPES); | 
|  | return Context.getTUIndex(); | 
|  | } | 
|  |  | 
|  | DWARFDie DWARFUnit::getParent(const DWARFDebugInfoEntry *Die) { | 
|  | if (!Die) | 
|  | return DWARFDie(); | 
|  |  | 
|  | if (Optional<uint32_t> ParentIdx = Die->getParentIdx()) { | 
|  | assert(*ParentIdx < DieArray.size() && | 
|  | "ParentIdx is out of DieArray boundaries"); | 
|  | return DWARFDie(this, &DieArray[*ParentIdx]); | 
|  | } | 
|  |  | 
|  | return DWARFDie(); | 
|  | } | 
|  |  | 
|  | DWARFDie DWARFUnit::getSibling(const DWARFDebugInfoEntry *Die) { | 
|  | if (!Die) | 
|  | return DWARFDie(); | 
|  |  | 
|  | if (Optional<uint32_t> SiblingIdx = Die->getSiblingIdx()) { | 
|  | assert(*SiblingIdx < DieArray.size() && | 
|  | "SiblingIdx is out of DieArray boundaries"); | 
|  | return DWARFDie(this, &DieArray[*SiblingIdx]); | 
|  | } | 
|  |  | 
|  | return DWARFDie(); | 
|  | } | 
|  |  | 
|  | DWARFDie DWARFUnit::getPreviousSibling(const DWARFDebugInfoEntry *Die) { | 
|  | if (!Die) | 
|  | return DWARFDie(); | 
|  |  | 
|  | Optional<uint32_t> ParentIdx = Die->getParentIdx(); | 
|  | if (!ParentIdx) | 
|  | // Die is a root die, there is no previous sibling. | 
|  | return DWARFDie(); | 
|  |  | 
|  | assert(*ParentIdx < DieArray.size() && | 
|  | "ParentIdx is out of DieArray boundaries"); | 
|  | assert(getDIEIndex(Die) > 0 && "Die is a root die"); | 
|  |  | 
|  | uint32_t PrevDieIdx = getDIEIndex(Die) - 1; | 
|  | if (PrevDieIdx == *ParentIdx) | 
|  | // Immediately previous node is parent, there is no previous sibling. | 
|  | return DWARFDie(); | 
|  |  | 
|  | while (DieArray[PrevDieIdx].getParentIdx() != *ParentIdx) { | 
|  | PrevDieIdx = *DieArray[PrevDieIdx].getParentIdx(); | 
|  |  | 
|  | assert(PrevDieIdx < DieArray.size() && | 
|  | "PrevDieIdx is out of DieArray boundaries"); | 
|  | assert(PrevDieIdx >= *ParentIdx && | 
|  | "PrevDieIdx is not a child of parent of Die"); | 
|  | } | 
|  |  | 
|  | return DWARFDie(this, &DieArray[PrevDieIdx]); | 
|  | } | 
|  |  | 
|  | DWARFDie DWARFUnit::getFirstChild(const DWARFDebugInfoEntry *Die) { | 
|  | if (!Die->hasChildren()) | 
|  | return DWARFDie(); | 
|  |  | 
|  | // TODO: Instead of checking here for invalid die we might reject | 
|  | // invalid dies at parsing stage(DWARFUnit::extractDIEsToVector). | 
|  | // We do not want access out of bounds when parsing corrupted debug data. | 
|  | size_t I = getDIEIndex(Die) + 1; | 
|  | if (I >= DieArray.size()) | 
|  | return DWARFDie(); | 
|  | return DWARFDie(this, &DieArray[I]); | 
|  | } | 
|  |  | 
|  | DWARFDie DWARFUnit::getLastChild(const DWARFDebugInfoEntry *Die) { | 
|  | if (!Die->hasChildren()) | 
|  | return DWARFDie(); | 
|  |  | 
|  | if (Optional<uint32_t> SiblingIdx = Die->getSiblingIdx()) { | 
|  | assert(*SiblingIdx < DieArray.size() && | 
|  | "SiblingIdx is out of DieArray boundaries"); | 
|  | assert(DieArray[*SiblingIdx - 1].getTag() == dwarf::DW_TAG_null && | 
|  | "Bad end of children marker"); | 
|  | return DWARFDie(this, &DieArray[*SiblingIdx - 1]); | 
|  | } | 
|  |  | 
|  | // If SiblingIdx is set for non-root dies we could be sure that DWARF is | 
|  | // correct and "end of children marker" must be found. For root die we do not | 
|  | // have such a guarantee(parsing root die might be stopped if "end of children | 
|  | // marker" is missing, SiblingIdx is always zero for root die). That is why we | 
|  | // do not use assertion for checking for "end of children marker" for root | 
|  | // die. | 
|  |  | 
|  | // TODO: Instead of checking here for invalid die we might reject | 
|  | // invalid dies at parsing stage(DWARFUnit::extractDIEsToVector). | 
|  | if (getDIEIndex(Die) == 0 && DieArray.size() > 1 && | 
|  | DieArray.back().getTag() == dwarf::DW_TAG_null) { | 
|  | // For the unit die we might take last item from DieArray. | 
|  | assert(getDIEIndex(Die) == getDIEIndex(getUnitDIE()) && "Bad unit die"); | 
|  | return DWARFDie(this, &DieArray.back()); | 
|  | } | 
|  |  | 
|  | return DWARFDie(); | 
|  | } | 
|  |  | 
|  | const DWARFAbbreviationDeclarationSet *DWARFUnit::getAbbreviations() const { | 
|  | if (!Abbrevs) | 
|  | Abbrevs = Abbrev->getAbbreviationDeclarationSet(getAbbreviationsOffset()); | 
|  | return Abbrevs; | 
|  | } | 
|  |  | 
|  | llvm::Optional<object::SectionedAddress> DWARFUnit::getBaseAddress() { | 
|  | if (BaseAddr) | 
|  | return BaseAddr; | 
|  |  | 
|  | DWARFDie UnitDie = getUnitDIE(); | 
|  | Optional<DWARFFormValue> PC = UnitDie.find({DW_AT_low_pc, DW_AT_entry_pc}); | 
|  | BaseAddr = toSectionedAddress(PC); | 
|  | return BaseAddr; | 
|  | } | 
|  |  | 
|  | Expected<StrOffsetsContributionDescriptor> | 
|  | StrOffsetsContributionDescriptor::validateContributionSize( | 
|  | DWARFDataExtractor &DA) { | 
|  | uint8_t EntrySize = getDwarfOffsetByteSize(); | 
|  | // In order to ensure that we don't read a partial record at the end of | 
|  | // the section we validate for a multiple of the entry size. | 
|  | uint64_t ValidationSize = alignTo(Size, EntrySize); | 
|  | // Guard against overflow. | 
|  | if (ValidationSize >= Size) | 
|  | if (DA.isValidOffsetForDataOfSize((uint32_t)Base, ValidationSize)) | 
|  | return *this; | 
|  | return createStringError(errc::invalid_argument, "length exceeds section size"); | 
|  | } | 
|  |  | 
|  | // Look for a DWARF64-formatted contribution to the string offsets table | 
|  | // starting at a given offset and record it in a descriptor. | 
|  | static Expected<StrOffsetsContributionDescriptor> | 
|  | parseDWARF64StringOffsetsTableHeader(DWARFDataExtractor &DA, uint64_t Offset) { | 
|  | if (!DA.isValidOffsetForDataOfSize(Offset, 16)) | 
|  | return createStringError(errc::invalid_argument, "section offset exceeds section size"); | 
|  |  | 
|  | if (DA.getU32(&Offset) != dwarf::DW_LENGTH_DWARF64) | 
|  | return createStringError(errc::invalid_argument, "32 bit contribution referenced from a 64 bit unit"); | 
|  |  | 
|  | uint64_t Size = DA.getU64(&Offset); | 
|  | uint8_t Version = DA.getU16(&Offset); | 
|  | (void)DA.getU16(&Offset); // padding | 
|  | // The encoded length includes the 2-byte version field and the 2-byte | 
|  | // padding, so we need to subtract them out when we populate the descriptor. | 
|  | return StrOffsetsContributionDescriptor(Offset, Size - 4, Version, DWARF64); | 
|  | } | 
|  |  | 
|  | // Look for a DWARF32-formatted contribution to the string offsets table | 
|  | // starting at a given offset and record it in a descriptor. | 
|  | static Expected<StrOffsetsContributionDescriptor> | 
|  | parseDWARF32StringOffsetsTableHeader(DWARFDataExtractor &DA, uint64_t Offset) { | 
|  | if (!DA.isValidOffsetForDataOfSize(Offset, 8)) | 
|  | return createStringError(errc::invalid_argument, "section offset exceeds section size"); | 
|  |  | 
|  | uint32_t ContributionSize = DA.getU32(&Offset); | 
|  | if (ContributionSize >= dwarf::DW_LENGTH_lo_reserved) | 
|  | return createStringError(errc::invalid_argument, "invalid length"); | 
|  |  | 
|  | uint8_t Version = DA.getU16(&Offset); | 
|  | (void)DA.getU16(&Offset); // padding | 
|  | // The encoded length includes the 2-byte version field and the 2-byte | 
|  | // padding, so we need to subtract them out when we populate the descriptor. | 
|  | return StrOffsetsContributionDescriptor(Offset, ContributionSize - 4, Version, | 
|  | DWARF32); | 
|  | } | 
|  |  | 
|  | static Expected<StrOffsetsContributionDescriptor> | 
|  | parseDWARFStringOffsetsTableHeader(DWARFDataExtractor &DA, | 
|  | llvm::dwarf::DwarfFormat Format, | 
|  | uint64_t Offset) { | 
|  | StrOffsetsContributionDescriptor Desc; | 
|  | switch (Format) { | 
|  | case dwarf::DwarfFormat::DWARF64: { | 
|  | if (Offset < 16) | 
|  | return createStringError(errc::invalid_argument, "insufficient space for 64 bit header prefix"); | 
|  | auto DescOrError = parseDWARF64StringOffsetsTableHeader(DA, Offset - 16); | 
|  | if (!DescOrError) | 
|  | return DescOrError.takeError(); | 
|  | Desc = *DescOrError; | 
|  | break; | 
|  | } | 
|  | case dwarf::DwarfFormat::DWARF32: { | 
|  | if (Offset < 8) | 
|  | return createStringError(errc::invalid_argument, "insufficient space for 32 bit header prefix"); | 
|  | auto DescOrError = parseDWARF32StringOffsetsTableHeader(DA, Offset - 8); | 
|  | if (!DescOrError) | 
|  | return DescOrError.takeError(); | 
|  | Desc = *DescOrError; | 
|  | break; | 
|  | } | 
|  | } | 
|  | return Desc.validateContributionSize(DA); | 
|  | } | 
|  |  | 
|  | Expected<Optional<StrOffsetsContributionDescriptor>> | 
|  | DWARFUnit::determineStringOffsetsTableContribution(DWARFDataExtractor &DA) { | 
|  | assert(!IsDWO); | 
|  | auto OptOffset = toSectionOffset(getUnitDIE().find(DW_AT_str_offsets_base)); | 
|  | if (!OptOffset) | 
|  | return None; | 
|  | auto DescOrError = | 
|  | parseDWARFStringOffsetsTableHeader(DA, Header.getFormat(), *OptOffset); | 
|  | if (!DescOrError) | 
|  | return DescOrError.takeError(); | 
|  | return *DescOrError; | 
|  | } | 
|  |  | 
|  | Expected<Optional<StrOffsetsContributionDescriptor>> | 
|  | DWARFUnit::determineStringOffsetsTableContributionDWO(DWARFDataExtractor & DA) { | 
|  | assert(IsDWO); | 
|  | uint64_t Offset = 0; | 
|  | auto IndexEntry = Header.getIndexEntry(); | 
|  | const auto *C = | 
|  | IndexEntry ? IndexEntry->getContribution(DW_SECT_STR_OFFSETS) : nullptr; | 
|  | if (C) | 
|  | Offset = C->Offset; | 
|  | if (getVersion() >= 5) { | 
|  | if (DA.getData().data() == nullptr) | 
|  | return None; | 
|  | Offset += Header.getFormat() == dwarf::DwarfFormat::DWARF32 ? 8 : 16; | 
|  | // Look for a valid contribution at the given offset. | 
|  | auto DescOrError = parseDWARFStringOffsetsTableHeader(DA, Header.getFormat(), Offset); | 
|  | if (!DescOrError) | 
|  | return DescOrError.takeError(); | 
|  | return *DescOrError; | 
|  | } | 
|  | // Prior to DWARF v5, we derive the contribution size from the | 
|  | // index table (in a package file). In a .dwo file it is simply | 
|  | // the length of the string offsets section. | 
|  | StrOffsetsContributionDescriptor Desc; | 
|  | if (C) | 
|  | Desc = StrOffsetsContributionDescriptor(C->Offset, C->Length, 4, | 
|  | Header.getFormat()); | 
|  | else if (!IndexEntry && !StringOffsetSection.Data.empty()) | 
|  | Desc = StrOffsetsContributionDescriptor(0, StringOffsetSection.Data.size(), | 
|  | 4, Header.getFormat()); | 
|  | else | 
|  | return None; | 
|  | auto DescOrError = Desc.validateContributionSize(DA); | 
|  | if (!DescOrError) | 
|  | return DescOrError.takeError(); | 
|  | return *DescOrError; | 
|  | } | 
|  |  | 
|  | Optional<uint64_t> DWARFUnit::getRnglistOffset(uint32_t Index) { | 
|  | DataExtractor RangesData(RangeSection->Data, isLittleEndian, | 
|  | getAddressByteSize()); | 
|  | DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection, | 
|  | isLittleEndian, 0); | 
|  | if (Optional<uint64_t> Off = llvm::DWARFListTableHeader::getOffsetEntry( | 
|  | RangesData, RangeSectionBase, getFormat(), Index)) | 
|  | return *Off + RangeSectionBase; | 
|  | return None; | 
|  | } | 
|  |  | 
|  | Optional<uint64_t> DWARFUnit::getLoclistOffset(uint32_t Index) { | 
|  | if (Optional<uint64_t> Off = llvm::DWARFListTableHeader::getOffsetEntry( | 
|  | LocTable->getData(), LocSectionBase, getFormat(), Index)) | 
|  | return *Off + LocSectionBase; | 
|  | return None; | 
|  | } |