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Diffstat (limited to 'third_party/llvm-project/DWARFUnit.cpp')
| -rw-r--r-- | third_party/llvm-project/DWARFUnit.cpp | 904 |
1 files changed, 904 insertions, 0 deletions
diff --git a/third_party/llvm-project/DWARFUnit.cpp b/third_party/llvm-project/DWARFUnit.cpp new file mode 100644 index 000000000..a56402a70 --- /dev/null +++ b/third_party/llvm-project/DWARFUnit.cpp @@ -0,0 +1,904 @@ +//===- 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/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/DWARFDebugRnglists.h" +#include "llvm/DebugInfo/DWARF/DWARFDie.h" +#include "llvm/DebugInfo/DWARF/DWARFFormValue.h" +#include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h" +#include "llvm/Support/DataExtractor.h" +#include "llvm/Support/Errc.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 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; + const DWARFUnitIndex *Index = nullptr; + if (IsDWO) + Index = &getDWARFUnitIndex(Context, SectionKind); + DWARFUnitHeader Header; + if (!Header.extract(Context, Data, &Offset, SectionKind, Index, + 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.getOffset(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), LocSection(LocSection), LineSection(LS), + StringSection(SS), StringOffsetSection(SOS), AddrOffsetSection(AOS), + isLittleEndian(LE), IsDWO(IsDWO), UnitVector(UnitVector) { + clear(); + // For split DWARF we only need to keep track of the location list section's + // data (no relocations), and if we are reading a package file, we need to + // adjust the location list data based on the index entries. + if (IsDWO) { + LocSectionData = LocSection->Data; + if (auto *IndexEntry = Header.getIndexEntry()) + if (const auto *C = IndexEntry->getOffset(DW_SECT_LOC)) + LocSectionData = LocSectionData.substr(C->Offset, C->Length); + } +} + +DWARFUnit::~DWARFUnit() = default; + +DWARFDataExtractor DWARFUnit::getDebugInfoExtractor() const { + return DWARFDataExtractor(Context.getDWARFObj(), InfoSection, isLittleEndian, + getAddressByteSize()); +} + +Optional<object::SectionedAddress> +DWARFUnit::getAddrOffsetSectionItem(uint32_t Index) const { + if (IsDWO) { + auto R = Context.info_section_units(); + auto I = R.begin(); + // 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 (I != R.end() && std::next(I) == R.end()) + return (*I)->getAddrOffsetSectionItem(Index); + } + 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}}; +} + +Optional<uint64_t> DWARFUnit::getStringOffsetSectionItem(uint32_t Index) const { + if (!StringOffsetsTableContribution) + return None; + unsigned ItemSize = getDwarfStringOffsetsByteSize(); + uint64_t Offset = getStringOffsetsBase() + Index * ItemSize; + if (StringOffsetSection.Data.size() < Offset + ItemSize) + return None; + 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, + const DWARFUnitIndex *Index, + const DWARFUnitIndex::Entry *Entry) { + Offset = *offset_ptr; + IndexEntry = Entry; + if (!IndexEntry && Index) + IndexEntry = Index->getFromOffset(*offset_ptr); + Length = debug_info.getRelocatedValue(4, offset_ptr); + FormParams.Format = DWARF32; + if (Length == dwarf::DW_LENGTH_DWARF64) { + Length = debug_info.getU64(offset_ptr); + FormParams.Format = DWARF64; + } + 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.getRelocatedValue(FormParams.getDwarfOffsetByteSize(), offset_ptr); + } else { + AbbrOffset = debug_info.getRelocatedValue(FormParams.getDwarfOffsetByteSize(), 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.getUnsigned(offset_ptr, FormParams.getDwarfOffsetByteSize()); + } 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() + getUnitLengthFieldByteSize(); + 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, uint64_t Offset, + DwarfFormat Format) { + // We are expected to be called with Offset 0 or pointing just past the table + // header. Correct Offset in the latter case so that it points to the start + // of the header. + if (Offset > 0) { + uint64_t HeaderSize = DWARFListTableHeader::getHeaderSize(Format); + if (Offset < HeaderSize) + return createStringError(errc::invalid_argument, "Did not detect a valid" + " range list table with base = 0x%" PRIx64 "\n", + Offset); + Offset -= HeaderSize; + } + llvm::DWARFDebugRnglistTable Table; + if (Error E = Table.extractHeaderAndOffsets(DA, &Offset)) + return std::move(E); + return Table; +} + +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; + 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. + uint64_t DIEOffset = getOffset() + getHeaderSize(); + uint64_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%8.8" PRIx64 " " + "at 0x%8.8" PRIx64 "\n", + getOffset(), DIEOffset); +} + +void DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) { + if (Error e = tryExtractDIEsIfNeeded(CUDieOnly)) + WithColor::error() << toString(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 == 0); + assert(RangeSectionBase == 0); + AddrOffsetSectionBase = toSectionOffset(UnitDie.find(DW_AT_addr_base), 0); + if (!AddrOffsetSectionBase) + 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. + 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) { + 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); + auto TableOrError = parseRngListTableHeader(RangesDA, RangeSectionBase, + Header.getFormat()); + if (!TableOrError) + return createStringError(errc::invalid_argument, + "parsing a range list table: " + + toString(TableOrError.takeError())); + + RngListTable = TableOrError.get(); + + // 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 Error::success(); +} + +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, + Header.getFormat())) + 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(uint64_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(), *this); + return RangeListOrError.takeError(); + } + + return createStringError(errc::invalid_argument, + "missing or invalid range list table"); +} + +Expected<DWARFAddressRangesVector> +DWARFUnit::findRnglistFromIndex(uint32_t Index) { + if (auto Offset = getRnglistOffset(Index)) + return findRnglistFromOffset(*Offset + RangeSectionBase); + + if (RngListTable) + return createStringError(errc::invalid_argument, + "invalid range list table index %d", Index); + + return createStringError(errc::invalid_argument, + "missing or invalid range list table"); +} + +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; +} + +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 : *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<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) { + uint64_t Offset; + if (IsDWO) { + Offset = 0; + if (DA.getData().data() == nullptr) + return None; + } else { + auto OptOffset = toSectionOffset(getUnitDIE().find(DW_AT_str_offsets_base)); + if (!OptOffset) + return None; + Offset = *OptOffset; + } + auto DescOrError = parseDWARFStringOffsetsTableHeader(DA, Header.getFormat(), Offset); + if (!DescOrError) + return DescOrError.takeError(); + return *DescOrError; +} + +Expected<Optional<StrOffsetsContributionDescriptor>> +DWARFUnit::determineStringOffsetsTableContributionDWO(DWARFDataExtractor & DA) { + uint64_t Offset = 0; + auto IndexEntry = Header.getIndexEntry(); + const auto *C = + IndexEntry ? IndexEntry->getOffset(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. + if (!IndexEntry) + return { + Optional<StrOffsetsContributionDescriptor>( + {0, StringOffsetSection.Data.size(), 4, DWARF32})}; + if (C) + return {Optional<StrOffsetsContributionDescriptor>( + {C->Offset, C->Length, 4, DWARF32})}; + return None; +} |