| //===- DWARFUnit.cpp ------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/DebugInfo/DWARF/DWARFUnit.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h" |
| #include "llvm/DebugInfo/DWARF/DWARFContext.h" |
| #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h" |
| #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h" |
| #include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h" |
| #include "llvm/DebugInfo/DWARF/DWARFDie.h" |
| #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" |
| #include "llvm/Support/DataExtractor.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/WithColor.h" |
| #include <algorithm> |
| #include <cassert> |
| #include <cstddef> |
| #include <cstdint> |
| #include <cstdio> |
| #include <utility> |
| #include <vector> |
| |
| using namespace llvm; |
| using namespace dwarf; |
| |
| void DWARFUnitSectionBase::parse(DWARFContext &C, const DWARFSection &Section) { |
| const DWARFObject &D = C.getDWARFObj(); |
| parseImpl(C, D, Section, C.getDebugAbbrev(), &D.getRangeSection(), |
| D.getStringSection(), D.getStringOffsetSection(), |
| &D.getAddrSection(), D.getLineSection(), D.isLittleEndian(), false, |
| false); |
| } |
| |
| void DWARFUnitSectionBase::parseDWO(DWARFContext &C, |
| const DWARFSection &DWOSection, bool Lazy) { |
| const DWARFObject &D = C.getDWARFObj(); |
| parseImpl(C, D, DWOSection, C.getDebugAbbrevDWO(), &D.getRangeDWOSection(), |
| D.getStringDWOSection(), D.getStringOffsetDWOSection(), |
| &D.getAddrSection(), D.getLineDWOSection(), C.isLittleEndian(), |
| true, Lazy); |
| } |
| |
| DWARFUnit::DWARFUnit(DWARFContext &DC, const DWARFSection &Section, |
| const DWARFUnitHeader &Header, |
| const DWARFDebugAbbrev *DA, const DWARFSection *RS, |
| StringRef SS, const DWARFSection &SOS, |
| const DWARFSection *AOS, const DWARFSection &LS, bool LE, |
| bool IsDWO, const DWARFUnitSectionBase &UnitSection) |
| : Context(DC), InfoSection(Section), Header(Header), Abbrev(DA), |
| RangeSection(RS), LineSection(LS), StringSection(SS), |
| StringOffsetSection(SOS), AddrOffsetSection(AOS), isLittleEndian(LE), |
| isDWO(IsDWO), UnitSection(UnitSection) { |
| clear(); |
| } |
| |
| DWARFUnit::~DWARFUnit() = default; |
| |
| DWARFDataExtractor DWARFUnit::getDebugInfoExtractor() const { |
| return DWARFDataExtractor(Context.getDWARFObj(), InfoSection, isLittleEndian, |
| getAddressByteSize()); |
| } |
| |
| bool DWARFUnit::getAddrOffsetSectionItem(uint32_t Index, |
| uint64_t &Result) const { |
| uint32_t Offset = AddrOffsetSectionBase + Index * getAddressByteSize(); |
| if (AddrOffsetSection->Data.size() < Offset + getAddressByteSize()) |
| return false; |
| DWARFDataExtractor DA(Context.getDWARFObj(), *AddrOffsetSection, |
| isLittleEndian, getAddressByteSize()); |
| Result = DA.getRelocatedAddress(&Offset); |
| return true; |
| } |
| |
| bool DWARFUnit::getStringOffsetSectionItem(uint32_t Index, |
| uint64_t &Result) const { |
| if (!StringOffsetsTableContribution) |
| return false; |
| unsigned ItemSize = getDwarfStringOffsetsByteSize(); |
| uint32_t Offset = getStringOffsetsBase() + Index * ItemSize; |
| if (StringOffsetSection.Data.size() < Offset + ItemSize) |
| return false; |
| DWARFDataExtractor DA(Context.getDWARFObj(), StringOffsetSection, |
| isLittleEndian, 0); |
| Result = DA.getRelocatedValue(ItemSize, &Offset); |
| return true; |
| } |
| |
| bool DWARFUnitHeader::extract(DWARFContext &Context, |
| const DWARFDataExtractor &debug_info, |
| uint32_t *offset_ptr, |
| DWARFSectionKind SectionKind, |
| const DWARFUnitIndex *Index) { |
| Offset = *offset_ptr; |
| IndexEntry = Index ? Index->getFromOffset(*offset_ptr) : nullptr; |
| Length = debug_info.getU32(offset_ptr); |
| // FIXME: Support DWARF64. |
| unsigned SizeOfLength = 4; |
| FormParams.Format = DWARF32; |
| FormParams.Version = debug_info.getU16(offset_ptr); |
| if (FormParams.Version >= 5) { |
| UnitType = debug_info.getU8(offset_ptr); |
| FormParams.AddrSize = debug_info.getU8(offset_ptr); |
| AbbrOffset = debug_info.getU32(offset_ptr); |
| } else { |
| AbbrOffset = debug_info.getRelocatedValue(4, offset_ptr); |
| FormParams.AddrSize = debug_info.getU8(offset_ptr); |
| // 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_TYPES) |
| UnitType = DW_UT_type; |
| else |
| UnitType = DW_UT_compile; |
| } |
| if (IndexEntry) { |
| if (AbbrOffset) |
| return false; |
| auto *UnitContrib = IndexEntry->getOffset(); |
| if (!UnitContrib || UnitContrib->Length != (Length + 4)) |
| return false; |
| auto *AbbrEntry = IndexEntry->getOffset(DW_SECT_ABBREV); |
| if (!AbbrEntry) |
| return false; |
| AbbrOffset = AbbrEntry->Offset; |
| } |
| if (isTypeUnit()) { |
| TypeHash = debug_info.getU64(offset_ptr); |
| TypeOffset = debug_info.getU32(offset_ptr); |
| } else if (UnitType == DW_UT_split_compile || UnitType == DW_UT_skeleton) |
| DWOId = debug_info.getU64(offset_ptr); |
| |
| // 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); |
| |
| // Type offset is unit-relative; should be after the header and before |
| // the end of the current unit. |
| bool TypeOffsetOK = |
| !isTypeUnit() |
| ? true |
| : TypeOffset >= Size && TypeOffset < getLength() + SizeOfLength; |
| bool LengthOK = debug_info.isValidOffset(getNextUnitOffset() - 1); |
| bool VersionOK = DWARFContext::isSupportedVersion(getVersion()); |
| bool AddrSizeOK = getAddressByteSize() == 4 || getAddressByteSize() == 8; |
| |
| if (!LengthOK || !VersionOK || !AddrSizeOK || !TypeOffsetOK) |
| return false; |
| |
| // Keep track of the highest DWARF version we encounter across all units. |
| Context.setMaxVersionIfGreater(getVersion()); |
| return true; |
| } |
| |
| // Parse the rangelist table header, including the optional array of offsets |
| // following it (DWARF v5 and later). |
| static Expected<DWARFDebugRnglistTable> |
| parseRngListTableHeader(DWARFDataExtractor &DA, uint32_t Offset) { |
| // TODO: Support DWARF64 |
| // We are expected to be called with Offset 0 or pointing just past the table |
| // header, which is 12 bytes long for DWARF32. |
| if (Offset > 0) { |
| if (Offset < 12U) { |
| std::string Buffer; |
| raw_string_ostream Stream(Buffer); |
| Stream << format( |
| "Did not detect a valid range list table with base = 0x%x", Offset); |
| return make_error<StringError>(Stream.str(), inconvertibleErrorCode()); |
| } |
| Offset -= 12U; |
| } |
| llvm::DWARFDebugRnglistTable Table; |
| if (Error E = Table.extractHeaderAndOffsets(DA, &Offset)) |
| return std::move(E); |
| return Table; |
| } |
| |
| Error DWARFUnit::extractRangeList(uint32_t RangeListOffset, |
| DWARFDebugRangeList &RangeList) const { |
| // Require that compile unit is extracted. |
| assert(!DieArray.empty()); |
| DWARFDataExtractor RangesData(Context.getDWARFObj(), *RangeSection, |
| isLittleEndian, getAddressByteSize()); |
| uint32_t ActualRangeListOffset = RangeSectionBase + RangeListOffset; |
| return RangeList.extract(RangesData, &ActualRangeListOffset); |
| } |
| |
| void DWARFUnit::clear() { |
| Abbrevs = nullptr; |
| BaseAddr.reset(); |
| RangeSectionBase = 0; |
| AddrOffsetSectionBase = 0; |
| clearDIEs(false); |
| 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. |
| uint32_t DIEOffset = getOffset() + getHeaderSize(); |
| uint32_t NextCUOffset = getNextUnitOffset(); |
| DWARFDebugInfoEntry DIE; |
| DWARFDataExtractor DebugInfoData = getDebugInfoExtractor(); |
| uint32_t Depth = 0; |
| bool IsCUDie = true; |
| |
| while (DIE.extractFast(*this, &DIEOffset, DebugInfoData, NextCUOffset, |
| Depth)) { |
| 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); |
| IsCUDie = false; |
| } else { |
| Dies.push_back(DIE); |
| } |
| |
| if (const DWARFAbbreviationDeclaration *AbbrDecl = |
| DIE.getAbbreviationDeclarationPtr()) { |
| // Normal DIE |
| if (AbbrDecl->hasChildren()) |
| ++Depth; |
| } else { |
| // NULL DIE. |
| if (Depth > 0) |
| --Depth; |
| if (Depth == 0) |
| break; // We are done with this compile unit! |
| } |
| } |
| |
| // Give a little bit of info if we encounter corrupt DWARF (our offset |
| // should always terminate at or before the start of the next compilation |
| // unit header). |
| if (DIEOffset > NextCUOffset) |
| WithColor::warning() << format("DWARF compile unit extends beyond its " |
| "bounds cu 0x%8.8x at 0x%8.8x\n", |
| getOffset(), DIEOffset); |
| } |
| |
| size_t DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) { |
| if ((CUDieOnly && !DieArray.empty()) || |
| DieArray.size() > 1) |
| return 0; // Already parsed. |
| |
| bool HasCUDie = !DieArray.empty(); |
| extractDIEsToVector(!HasCUDie, !CUDieOnly, DieArray); |
| |
| if (DieArray.empty()) |
| return 0; |
| |
| // If CU DIE was just parsed, copy several attribute values from it. |
| if (!HasCUDie) { |
| DWARFDie UnitDie = getUnitDIE(); |
| if (Optional<uint64_t> DWOId = toUnsigned(UnitDie.find(DW_AT_GNU_dwo_id))) |
| Header.setDWOId(*DWOId); |
| if (!isDWO) { |
| assert(AddrOffsetSectionBase == 0); |
| assert(RangeSectionBase == 0); |
| AddrOffsetSectionBase = |
| toSectionOffset(UnitDie.find(DW_AT_GNU_addr_base), 0); |
| RangeSectionBase = toSectionOffset(UnitDie.find(DW_AT_rnglists_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. |
| uint64_t StringOffsetsContributionBase = |
| isDWO ? 0 : toSectionOffset(UnitDie.find(DW_AT_str_offsets_base), 0); |
| auto IndexEntry = Header.getIndexEntry(); |
| if (IndexEntry) |
| if (const auto *C = IndexEntry->getOffset(DW_SECT_STR_OFFSETS)) |
| StringOffsetsContributionBase += C->Offset; |
| |
| DWARFDataExtractor DA(Context.getDWARFObj(), StringOffsetSection, |
| isLittleEndian, 0); |
| if (isDWO) |
| StringOffsetsTableContribution = |
| determineStringOffsetsTableContributionDWO( |
| DA, StringOffsetsContributionBase); |
| else if (getVersion() >= 5) |
| StringOffsetsTableContribution = determineStringOffsetsTableContribution( |
| DA, StringOffsetsContributionBase); |
| |
| // DWARF v5 uses the .debug_rnglists and .debug_rnglists.dwo sections to |
| // describe address ranges. |
| if (getVersion() >= 5) { |
| if (isDWO) |
| setRangesSection(&Context.getDWARFObj().getRnglistsDWOSection(), 0); |
| else |
| setRangesSection(&Context.getDWARFObj().getRnglistsSection(), |
| toSectionOffset(UnitDie.find(DW_AT_rnglists_base), 0)); |
| if (RangeSection->Data.size()) { |
| // Parse the range list table header. Individual range lists are |
| // extracted lazily. |
| DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection, |
| isLittleEndian, 0); |
| if (auto TableOrError = |
| parseRngListTableHeader(RangesDA, RangeSectionBase)) |
| RngListTable = TableOrError.get(); |
| else |
| WithColor::error() << "parsing a range list table: " |
| << toString(TableOrError.takeError()) |
| << '\n'; |
| |
| // In a split dwarf unit, there is no DW_AT_rnglists_base attribute. |
| // Adjust RangeSectionBase to point past the table header. |
| if (isDWO && RngListTable) |
| RangeSectionBase = RngListTable->getHeaderSize(); |
| } |
| } |
| |
| // 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 DieArray.size(); |
| } |
| |
| bool DWARFUnit::parseDWO() { |
| if (isDWO) |
| return false; |
| if (DWO.get()) |
| return false; |
| DWARFDie UnitDie = getUnitDIE(); |
| if (!UnitDie) |
| return false; |
| auto DWOFileName = 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); |
| // Share .debug_addr and .debug_ranges section with compile unit in .dwo |
| DWO->setAddrOffsetSection(AddrOffsetSection, AddrOffsetSectionBase); |
| if (getVersion() >= 5) { |
| DWO->setRangesSection(&Context.getDWARFObj().getRnglistsDWOSection(), 0); |
| DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection, |
| isLittleEndian, 0); |
| if (auto TableOrError = parseRngListTableHeader(RangesDA, RangeSectionBase)) |
| DWO->RngListTable = TableOrError.get(); |
| else |
| WithColor::error() << "parsing a range list table: " |
| << toString(TableOrError.takeError()) |
| << '\n'; |
| if (DWO->RngListTable) |
| DWO->RangeSectionBase = DWO->RngListTable->getHeaderSize(); |
| } else { |
| auto DWORangesBase = UnitDie.getRangesBaseAttribute(); |
| DWO->setRangesSection(RangeSection, DWORangesBase ? *DWORangesBase : 0); |
| } |
| |
| return true; |
| } |
| |
| void DWARFUnit::clearDIEs(bool KeepCUDie) { |
| if (DieArray.size() > (unsigned)KeepCUDie) { |
| DieArray.resize((unsigned)KeepCUDie); |
| DieArray.shrink_to_fit(); |
| } |
| } |
| |
| Expected<DWARFAddressRangesVector> |
| DWARFUnit::findRnglistFromOffset(uint32_t Offset) { |
| if (getVersion() <= 4) { |
| DWARFDebugRangeList RangeList; |
| if (Error E = extractRangeList(Offset, RangeList)) |
| return std::move(E); |
| return RangeList.getAbsoluteRanges(getBaseAddress()); |
| } |
| if (RngListTable) { |
| DWARFDataExtractor RangesData(Context.getDWARFObj(), *RangeSection, |
| isLittleEndian, RngListTable->getAddrSize()); |
| auto RangeListOrError = RngListTable->findList(RangesData, Offset); |
| if (RangeListOrError) |
| return RangeListOrError.get().getAbsoluteRanges(getBaseAddress()); |
| return RangeListOrError.takeError(); |
| } |
| |
| return make_error<StringError>("missing or invalid range list table", |
| inconvertibleErrorCode()); |
| } |
| |
| Expected<DWARFAddressRangesVector> |
| DWARFUnit::findRnglistFromIndex(uint32_t Index) { |
| if (auto Offset = getRnglistOffset(Index)) |
| return findRnglistFromOffset(*Offset + RangeSectionBase); |
| |
| std::string Buffer; |
| raw_string_ostream Stream(Buffer); |
| if (RngListTable) |
| Stream << format("invalid range list table index %d", Index); |
| else |
| Stream << "missing or invalid range list table"; |
| return make_error<StringError>(Stream.str(), inconvertibleErrorCode()); |
| } |
| |
| void DWARFUnit::collectAddressRanges(DWARFAddressRangesVector &CURanges) { |
| DWARFDie UnitDie = getUnitDIE(); |
| if (!UnitDie) |
| return; |
| // First, check if unit DIE describes address ranges for the whole unit. |
| auto CUDIERangesOrError = UnitDie.getAddressRanges(); |
| if (CUDIERangesOrError) { |
| if (!CUDIERangesOrError.get().empty()) { |
| CURanges.insert(CURanges.end(), CUDIERangesOrError.get().begin(), |
| CUDIERangesOrError.get().end()); |
| return; |
| } |
| } else |
| WithColor::error() << "decoding address ranges: " |
| << toString(CUDIERangesOrError.takeError()) << '\n'; |
| |
| // This function is usually called if there in no .debug_aranges section |
| // in order to produce a compile unit level set of address ranges that |
| // is accurate. If the DIEs weren't parsed, then we don't want all dies for |
| // all compile units to stay loaded when they weren't needed. So we can end |
| // up parsing the DWARF and then throwing them all away to keep memory usage |
| // down. |
| const bool ClearDIEs = extractDIEsIfNeeded(false) > 1; |
| getUnitDIE().collectChildrenAddressRanges(CURanges); |
| |
| // Collect address ranges from DIEs in .dwo if necessary. |
| bool DWOCreated = parseDWO(); |
| if (DWO) |
| DWO->collectAddressRanges(CURanges); |
| if (DWOCreated) |
| DWO.reset(); |
| |
| // Keep memory down by clearing DIEs if this generate function |
| // caused them to be parsed. |
| if (ClearDIEs) |
| clearDIEs(true); |
| } |
| |
| 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::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.get() : this)->getSubroutineForAddress(Address); |
| |
| if (!SubroutineDIE) |
| return; |
| |
| while (!SubroutineDIE.isSubprogramDIE()) { |
| if (SubroutineDIE.getTag() == DW_TAG_inlined_subroutine) |
| InlinedChain.push_back(SubroutineDIE); |
| SubroutineDIE = SubroutineDIE.getParent(); |
| } |
| InlinedChain.push_back(SubroutineDIE); |
| } |
| |
| const DWARFUnitIndex &llvm::getDWARFUnitIndex(DWARFContext &Context, |
| DWARFSectionKind Kind) { |
| if (Kind == DW_SECT_INFO) |
| return Context.getCUIndex(); |
| assert(Kind == DW_SECT_TYPES); |
| return Context.getTUIndex(); |
| } |
| |
| DWARFDie DWARFUnit::getParent(const DWARFDebugInfoEntry *Die) { |
| if (!Die) |
| return DWARFDie(); |
| const uint32_t Depth = Die->getDepth(); |
| // Unit DIEs always have a depth of zero and never have parents. |
| if (Depth == 0) |
| return DWARFDie(); |
| // Depth of 1 always means parent is the compile/type unit. |
| if (Depth == 1) |
| return getUnitDIE(); |
| // Look for previous DIE with a depth that is one less than the Die's depth. |
| const uint32_t ParentDepth = Depth - 1; |
| for (uint32_t I = getDIEIndex(Die) - 1; I > 0; --I) { |
| if (DieArray[I].getDepth() == ParentDepth) |
| return DWARFDie(this, &DieArray[I]); |
| } |
| return DWARFDie(); |
| } |
| |
| DWARFDie DWARFUnit::getSibling(const DWARFDebugInfoEntry *Die) { |
| if (!Die) |
| return DWARFDie(); |
| uint32_t Depth = Die->getDepth(); |
| // Unit DIEs always have a depth of zero and never have siblings. |
| if (Depth == 0) |
| return DWARFDie(); |
| // NULL DIEs don't have siblings. |
| if (Die->getAbbreviationDeclarationPtr() == nullptr) |
| return DWARFDie(); |
| |
| // Find the next DIE whose depth is the same as the Die's depth. |
| for (size_t I = getDIEIndex(Die) + 1, EndIdx = DieArray.size(); I < EndIdx; |
| ++I) { |
| if (DieArray[I].getDepth() == Depth) |
| return DWARFDie(this, &DieArray[I]); |
| } |
| return DWARFDie(); |
| } |
| |
| DWARFDie DWARFUnit::getPreviousSibling(const DWARFDebugInfoEntry *Die) { |
| if (!Die) |
| return DWARFDie(); |
| uint32_t Depth = Die->getDepth(); |
| // Unit DIEs always have a depth of zero and never have siblings. |
| if (Depth == 0) |
| return DWARFDie(); |
| |
| // Find the previous DIE whose depth is the same as the Die's depth. |
| for (size_t I = getDIEIndex(Die); I > 0;) { |
| --I; |
| if (DieArray[I].getDepth() == Depth - 1) |
| return DWARFDie(); |
| if (DieArray[I].getDepth() == Depth) |
| return DWARFDie(this, &DieArray[I]); |
| } |
| return DWARFDie(); |
| } |
| |
| DWARFDie DWARFUnit::getFirstChild(const DWARFDebugInfoEntry *Die) { |
| if (!Die->hasChildren()) |
| return DWARFDie(); |
| |
| // 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(); |
| |
| uint32_t Depth = Die->getDepth(); |
| for (size_t I = getDIEIndex(Die) + 1, EndIdx = DieArray.size(); I < EndIdx; |
| ++I) { |
| if (DieArray[I].getDepth() == Depth + 1 && |
| DieArray[I].getTag() == dwarf::DW_TAG_null) |
| return DWARFDie(this, &DieArray[I]); |
| assert(DieArray[I].getDepth() > Depth && "Not processing children?"); |
| } |
| return DWARFDie(); |
| } |
| |
| const DWARFAbbreviationDeclarationSet *DWARFUnit::getAbbreviations() const { |
| if (!Abbrevs) |
| Abbrevs = Abbrev->getAbbreviationDeclarationSet(Header.getAbbrOffset()); |
| return Abbrevs; |
| } |
| |
| llvm::Optional<BaseAddress> DWARFUnit::getBaseAddress() { |
| if (BaseAddr) |
| return BaseAddr; |
| |
| DWARFDie UnitDie = getUnitDIE(); |
| Optional<DWARFFormValue> PC = UnitDie.find({DW_AT_low_pc, DW_AT_entry_pc}); |
| if (Optional<uint64_t> Addr = toAddress(PC)) |
| BaseAddr = {*Addr, PC->getSectionIndex()}; |
| |
| return BaseAddr; |
| } |
| |
| Optional<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 Optional<StrOffsetsContributionDescriptor>(); |
| } |
| |
| // Look for a DWARF64-formatted contribution to the string offsets table |
| // starting at a given offset and record it in a descriptor. |
| static Optional<StrOffsetsContributionDescriptor> |
| parseDWARF64StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) { |
| if (!DA.isValidOffsetForDataOfSize(Offset, 16)) |
| return Optional<StrOffsetsContributionDescriptor>(); |
| |
| if (DA.getU32(&Offset) != 0xffffffff) |
| return Optional<StrOffsetsContributionDescriptor>(); |
| |
| 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); |
| //return Optional<StrOffsetsContributionDescriptor>(Descriptor); |
| } |
| |
| // Look for a DWARF32-formatted contribution to the string offsets table |
| // starting at a given offset and record it in a descriptor. |
| static Optional<StrOffsetsContributionDescriptor> |
| parseDWARF32StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) { |
| if (!DA.isValidOffsetForDataOfSize(Offset, 8)) |
| return Optional<StrOffsetsContributionDescriptor>(); |
| uint32_t ContributionSize = DA.getU32(&Offset); |
| if (ContributionSize >= 0xfffffff0) |
| return Optional<StrOffsetsContributionDescriptor>(); |
| 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); |
| //return Optional<StrOffsetsContributionDescriptor>(Descriptor); |
| } |
| |
| Optional<StrOffsetsContributionDescriptor> |
| DWARFUnit::determineStringOffsetsTableContribution(DWARFDataExtractor &DA, |
| uint64_t Offset) { |
| Optional<StrOffsetsContributionDescriptor> Descriptor; |
| // Attempt to find a DWARF64 contribution 16 bytes before the base. |
| if (Offset >= 16) |
| Descriptor = |
| parseDWARF64StringOffsetsTableHeader(DA, (uint32_t)Offset - 16); |
| // Try to find a DWARF32 contribution 8 bytes before the base. |
| if (!Descriptor && Offset >= 8) |
| Descriptor = parseDWARF32StringOffsetsTableHeader(DA, (uint32_t)Offset - 8); |
| return Descriptor ? Descriptor->validateContributionSize(DA) : Descriptor; |
| } |
| |
| Optional<StrOffsetsContributionDescriptor> |
| DWARFUnit::determineStringOffsetsTableContributionDWO(DWARFDataExtractor &DA, |
| uint64_t Offset) { |
| if (getVersion() >= 5) { |
| // Look for a valid contribution at the given offset. |
| auto Descriptor = |
| parseDWARF64StringOffsetsTableHeader(DA, (uint32_t)Offset); |
| if (!Descriptor) |
| Descriptor = parseDWARF32StringOffsetsTableHeader(DA, (uint32_t)Offset); |
| return Descriptor ? Descriptor->validateContributionSize(DA) : Descriptor; |
| } |
| // 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. |
| uint64_t Size = 0; |
| auto IndexEntry = Header.getIndexEntry(); |
| if (!IndexEntry) |
| Size = StringOffsetSection.Data.size(); |
| else if (const auto *C = IndexEntry->getOffset(DW_SECT_STR_OFFSETS)) |
| Size = C->Length; |
| // Return a descriptor with the given offset as base, version 4 and |
| // DWARF32 format. |
| //return Optional<StrOffsetsContributionDescriptor>( |
| //StrOffsetsContributionDescriptor(Offset, Size, 4, DWARF32)); |
| return StrOffsetsContributionDescriptor(Offset, Size, 4, DWARF32); |
| } |
