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llvm-project/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp

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//===- 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/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.getRangeSection(),
&D.getLocSection(), D.getStringSection(),
D.getStringOffsetSection(), &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.getRangeDWOSection(),
&D.getLocDWOSection(), D.getStringDWOSection(),
D.getStringOffsetDWOSection(), &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](uint32_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 = llvm::make_unique<DWARFTypeUnit>(Context, InfoSection, Header, DA,
RS, LocSection, SS, SOS, AOS, LS,
LE, IsDWO, *this);
else
U = llvm::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();
uint32_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(uint32_t Offset) const {
auto end = begin() + getNumInfoUnits();
auto *CU =
std::upper_bound(begin(), end, Offset,
[](uint32_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,
[](uint32_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<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);
}
uint32_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();
uint32_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,
uint32_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.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)
return createStringError(errc::invalid_argument, "Did not detect a valid"
" range list table with base = 0x%" PRIu32,
Offset);
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_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)
StringOffsetsTableContribution =
determineStringOffsetsTableContributionDWO(DA);
else if (getVersion() >= 5)
StringOffsetsTableContribution =
determineStringOffsetsTableContribution(DA);
// 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(), *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);
else
return createStringError(errc::invalid_argument,
"missing or invalid range list table");
}
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<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;
}
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 None;
}
// 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 None;
if (DA.getU32(&Offset) != 0xffffffff)
return None;
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 {{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 Optional<StrOffsetsContributionDescriptor>
parseDWARF32StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
if (!DA.isValidOffsetForDataOfSize(Offset, 8))
return None;
uint32_t ContributionSize = DA.getU32(&Offset);
if (ContributionSize >= 0xfffffff0)
return None;
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 {{Offset, ContributionSize - 4, Version, DWARF32}};
}
Optional<StrOffsetsContributionDescriptor>
DWARFUnit::determineStringOffsetsTableContribution(DWARFDataExtractor &DA) {
auto Offset = toSectionOffset(getUnitDIE().find(DW_AT_str_offsets_base), 0);
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 = 0;
auto IndexEntry = Header.getIndexEntry();
const auto *C =
IndexEntry ? IndexEntry->getOffset(DW_SECT_STR_OFFSETS) : nullptr;
if (C)
Offset = C->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.
if (!IndexEntry)
return {{0, StringOffsetSection.Data.size(), 4, DWARF32}};
if (C)
return {{C->Offset, C->Length, 4, DWARF32}};
return None;
}
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