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clang-p2996/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
Felipe de Azevedo Piovezan 15a1f7f6f7 [AppleTables] Implement iterator over all entries in table 
This commit adds functionality to the Apple Accelerator table allowing iteration
over all elements in the table.

Our iterators look like streaming iterators: when we increment the iterator we
check if there is still enough data in the "stream" (in our case, the blob of
data of the accelerator table) and extract the next entry. If any failures
occur, we immediately set the iterator to be the end iterator.

Since the ultimate user of this functionality is LLDB, there are roughly two
iteration methods we want support: one that also loads the name of each entry,
and one which does not. Loading names is measurably slower (one order the
magnitude) than only loading DIEs, so we used some template metaprograming to
implement both iteration methods.

Depends on D153066

Differential Revision: https://reviews.llvm.org/D153066
2023-06-21 06:44:56 -04:00

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//===- DWARFAcceleratorTable.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/DWARFAcceleratorTable.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/DJB.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/raw_ostream.h"
#include <cstddef>
#include <cstdint>
#include <utility>
using namespace llvm;
namespace {
struct Atom {
unsigned Value;
};
static raw_ostream &operator<<(raw_ostream &OS, const Atom &A) {
StringRef Str = dwarf::AtomTypeString(A.Value);
if (!Str.empty())
return OS << Str;
return OS << "DW_ATOM_unknown_" << format("%x", A.Value);
}
} // namespace
static Atom formatAtom(unsigned Atom) { return {Atom}; }
DWARFAcceleratorTable::~DWARFAcceleratorTable() = default;
Error AppleAcceleratorTable::extract() {
uint64_t Offset = 0;
// Check that we can at least read the header.
if (!AccelSection.isValidOffset(offsetof(Header, HeaderDataLength) + 4))
return createStringError(errc::illegal_byte_sequence,
"Section too small: cannot read header.");
Hdr.Magic = AccelSection.getU32(&Offset);
Hdr.Version = AccelSection.getU16(&Offset);
Hdr.HashFunction = AccelSection.getU16(&Offset);
Hdr.BucketCount = AccelSection.getU32(&Offset);
Hdr.HashCount = AccelSection.getU32(&Offset);
Hdr.HeaderDataLength = AccelSection.getU32(&Offset);
FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
// Check that we can read all the hashes and offsets from the
// section (see SourceLevelDebugging.rst for the structure of the index).
if (!AccelSection.isValidOffset(getIthBucketBase(Hdr.BucketCount - 1)))
return createStringError(
errc::illegal_byte_sequence,
"Section too small: cannot read buckets and hashes.");
HdrData.DIEOffsetBase = AccelSection.getU32(&Offset);
uint32_t NumAtoms = AccelSection.getU32(&Offset);
HashDataEntryLength = 0;
auto MakeUnsupportedFormError = [](dwarf::Form Form) {
return createStringError(errc::not_supported,
"Unsupported form:" +
dwarf::FormEncodingString(Form));
};
for (unsigned i = 0; i < NumAtoms; ++i) {
uint16_t AtomType = AccelSection.getU16(&Offset);
auto AtomForm = static_cast<dwarf::Form>(AccelSection.getU16(&Offset));
HdrData.Atoms.push_back(std::make_pair(AtomType, AtomForm));
std::optional<uint8_t> FormSize =
dwarf::getFixedFormByteSize(AtomForm, FormParams);
if (!FormSize)
return MakeUnsupportedFormError(AtomForm);
HashDataEntryLength += *FormSize;
}
IsValid = true;
return Error::success();
}
uint32_t AppleAcceleratorTable::getNumBuckets() const {
return Hdr.BucketCount;
}
uint32_t AppleAcceleratorTable::getNumHashes() const { return Hdr.HashCount; }
uint32_t AppleAcceleratorTable::getSizeHdr() const { return sizeof(Hdr); }
uint32_t AppleAcceleratorTable::getHeaderDataLength() const {
return Hdr.HeaderDataLength;
}
ArrayRef<std::pair<AppleAcceleratorTable::HeaderData::AtomType,
AppleAcceleratorTable::HeaderData::Form>>
AppleAcceleratorTable::getAtomsDesc() {
return HdrData.Atoms;
}
bool AppleAcceleratorTable::validateForms() {
for (auto Atom : getAtomsDesc()) {
DWARFFormValue FormValue(Atom.second);
switch (Atom.first) {
case dwarf::DW_ATOM_die_offset:
case dwarf::DW_ATOM_die_tag:
case dwarf::DW_ATOM_type_flags:
if ((!FormValue.isFormClass(DWARFFormValue::FC_Constant) &&
!FormValue.isFormClass(DWARFFormValue::FC_Flag)) ||
FormValue.getForm() == dwarf::DW_FORM_sdata)
return false;
break;
default:
break;
}
}
return true;
}
std::pair<uint64_t, dwarf::Tag>
AppleAcceleratorTable::readAtoms(uint64_t *HashDataOffset) {
uint64_t DieOffset = dwarf::DW_INVALID_OFFSET;
dwarf::Tag DieTag = dwarf::DW_TAG_null;
for (auto Atom : getAtomsDesc()) {
DWARFFormValue FormValue(Atom.second);
FormValue.extractValue(AccelSection, HashDataOffset, FormParams);
switch (Atom.first) {
case dwarf::DW_ATOM_die_offset:
DieOffset = *FormValue.getAsUnsignedConstant();
break;
case dwarf::DW_ATOM_die_tag:
DieTag = (dwarf::Tag)*FormValue.getAsUnsignedConstant();
break;
default:
break;
}
}
return {DieOffset, DieTag};
}
void AppleAcceleratorTable::Header::dump(ScopedPrinter &W) const {
DictScope HeaderScope(W, "Header");
W.printHex("Magic", Magic);
W.printHex("Version", Version);
W.printHex("Hash function", HashFunction);
W.printNumber("Bucket count", BucketCount);
W.printNumber("Hashes count", HashCount);
W.printNumber("HeaderData length", HeaderDataLength);
}
std::optional<uint64_t> AppleAcceleratorTable::HeaderData::extractOffset(
std::optional<DWARFFormValue> Value) const {
if (!Value)
return std::nullopt;
switch (Value->getForm()) {
case dwarf::DW_FORM_ref1:
case dwarf::DW_FORM_ref2:
case dwarf::DW_FORM_ref4:
case dwarf::DW_FORM_ref8:
case dwarf::DW_FORM_ref_udata:
return Value->getRawUValue() + DIEOffsetBase;
default:
return Value->getAsSectionOffset();
}
}
bool AppleAcceleratorTable::dumpName(ScopedPrinter &W,
SmallVectorImpl<DWARFFormValue> &AtomForms,
uint64_t *DataOffset) const {
uint64_t NameOffset = *DataOffset;
if (!AccelSection.isValidOffsetForDataOfSize(*DataOffset, 4)) {
W.printString("Incorrectly terminated list.");
return false;
}
uint64_t StringOffset = AccelSection.getRelocatedValue(4, DataOffset);
if (!StringOffset)
return false; // End of list
DictScope NameScope(W, ("Name@0x" + Twine::utohexstr(NameOffset)).str());
W.startLine() << format("String: 0x%08" PRIx64, StringOffset);
W.getOStream() << " \"" << StringSection.getCStr(&StringOffset) << "\"\n";
unsigned NumData = AccelSection.getU32(DataOffset);
for (unsigned Data = 0; Data < NumData; ++Data) {
ListScope DataScope(W, ("Data " + Twine(Data)).str());
unsigned i = 0;
for (auto &Atom : AtomForms) {
W.startLine() << format("Atom[%d]: ", i);
if (Atom.extractValue(AccelSection, DataOffset, FormParams)) {
Atom.dump(W.getOStream());
if (std::optional<uint64_t> Val = Atom.getAsUnsignedConstant()) {
StringRef Str = dwarf::AtomValueString(HdrData.Atoms[i].first, *Val);
if (!Str.empty())
W.getOStream() << " (" << Str << ")";
}
} else
W.getOStream() << "Error extracting the value";
W.getOStream() << "\n";
i++;
}
}
return true; // more entries follow
}
LLVM_DUMP_METHOD void AppleAcceleratorTable::dump(raw_ostream &OS) const {
if (!IsValid)
return;
ScopedPrinter W(OS);
Hdr.dump(W);
W.printNumber("DIE offset base", HdrData.DIEOffsetBase);
W.printNumber("Number of atoms", uint64_t(HdrData.Atoms.size()));
W.printNumber("Size of each hash data entry", getHashDataEntryLength());
SmallVector<DWARFFormValue, 3> AtomForms;
{
ListScope AtomsScope(W, "Atoms");
unsigned i = 0;
for (const auto &Atom : HdrData.Atoms) {
DictScope AtomScope(W, ("Atom " + Twine(i++)).str());
W.startLine() << "Type: " << formatAtom(Atom.first) << '\n';
W.startLine() << "Form: " << formatv("{0}", Atom.second) << '\n';
AtomForms.push_back(DWARFFormValue(Atom.second));
}
}
// Now go through the actual tables and dump them.
uint64_t Offset = sizeof(Hdr) + Hdr.HeaderDataLength;
uint64_t HashesBase = Offset + Hdr.BucketCount * 4;
uint64_t OffsetsBase = HashesBase + Hdr.HashCount * 4;
for (unsigned Bucket = 0; Bucket < Hdr.BucketCount; ++Bucket) {
unsigned Index = AccelSection.getU32(&Offset);
ListScope BucketScope(W, ("Bucket " + Twine(Bucket)).str());
if (Index == UINT32_MAX) {
W.printString("EMPTY");
continue;
}
for (unsigned HashIdx = Index; HashIdx < Hdr.HashCount; ++HashIdx) {
uint64_t HashOffset = HashesBase + HashIdx*4;
uint64_t OffsetsOffset = OffsetsBase + HashIdx*4;
uint32_t Hash = AccelSection.getU32(&HashOffset);
if (Hash % Hdr.BucketCount != Bucket)
break;
uint64_t DataOffset = AccelSection.getU32(&OffsetsOffset);
ListScope HashScope(W, ("Hash 0x" + Twine::utohexstr(Hash)).str());
if (!AccelSection.isValidOffset(DataOffset)) {
W.printString("Invalid section offset");
continue;
}
while (dumpName(W, AtomForms, &DataOffset))
/*empty*/;
}
}
}
AppleAcceleratorTable::Entry::Entry(const AppleAcceleratorTable &Table)
: Table(Table) {
Values.reserve(Table.HdrData.Atoms.size());
for (const auto &Atom : Table.HdrData.Atoms)
Values.push_back(DWARFFormValue(Atom.second));
}
void AppleAcceleratorTable::Entry::extract(uint64_t *Offset) {
for (auto &FormValue : Values)
FormValue.extractValue(Table.AccelSection, Offset, Table.FormParams);
}
std::optional<DWARFFormValue>
AppleAcceleratorTable::Entry::lookup(HeaderData::AtomType AtomToFind) const {
for (auto [Atom, FormValue] : zip_equal(Table.HdrData.Atoms, Values))
if (Atom.first == AtomToFind)
return FormValue;
return std::nullopt;
}
std::optional<uint64_t>
AppleAcceleratorTable::Entry::getDIESectionOffset() const {
return Table.HdrData.extractOffset(lookup(dwarf::DW_ATOM_die_offset));
}
std::optional<uint64_t> AppleAcceleratorTable::Entry::getCUOffset() const {
return Table.HdrData.extractOffset(lookup(dwarf::DW_ATOM_cu_offset));
}
std::optional<dwarf::Tag> AppleAcceleratorTable::Entry::getTag() const {
std::optional<DWARFFormValue> Tag = lookup(dwarf::DW_ATOM_die_tag);
if (!Tag)
return std::nullopt;
if (std::optional<uint64_t> Value = Tag->getAsUnsignedConstant())
return dwarf::Tag(*Value);
return std::nullopt;
}
AppleAcceleratorTable::SameNameIterator::SameNameIterator(
const AppleAcceleratorTable &AccelTable, uint64_t DataOffset)
: Current(AccelTable), Offset(DataOffset) {}
void AppleAcceleratorTable::Iterator::prepareNextEntryOrEnd() {
if (NumEntriesToCome == 0)
prepareNextStringOrEnd();
if (isEnd())
return;
uint64_t OffsetCopy = Offset;
Current.BaseEntry.extract(&OffsetCopy);
NumEntriesToCome--;
Offset += getTable().getHashDataEntryLength();
}
void AppleAcceleratorTable::Iterator::prepareNextStringOrEnd() {
std::optional<uint32_t> StrOffset = getTable().readStringOffsetAt(Offset);
if (!StrOffset)
return setToEnd();
// A zero denotes the end of the collision list. Read the next string
// again.
if (*StrOffset == 0)
return prepareNextStringOrEnd();
Current.StrOffset = *StrOffset;
std::optional<uint32_t> MaybeNumEntries = getTable().readU32FromAccel(Offset);
if (!MaybeNumEntries || *MaybeNumEntries == 0)
return setToEnd();
NumEntriesToCome = *MaybeNumEntries;
}
AppleAcceleratorTable::Iterator::Iterator(const AppleAcceleratorTable &Table,
bool SetEnd)
: Current(Table), Offset(Table.getEntriesBase()), NumEntriesToCome(0) {
if (SetEnd)
setToEnd();
else
prepareNextEntryOrEnd();
}
iterator_range<AppleAcceleratorTable::SameNameIterator>
AppleAcceleratorTable::equal_range(StringRef Key) const {
const auto EmptyRange =
make_range(SameNameIterator(*this, 0), SameNameIterator(*this, 0));
if (!IsValid)
return EmptyRange;
// Find the bucket.
uint32_t SearchHash = djbHash(Key);
uint32_t BucketIdx = hashToBucketIdx(SearchHash);
std::optional<uint32_t> HashIdx = idxOfHashInBucket(SearchHash, BucketIdx);
if (!HashIdx)
return EmptyRange;
std::optional<uint64_t> MaybeDataOffset = readIthOffset(*HashIdx);
if (!MaybeDataOffset)
return EmptyRange;
uint64_t DataOffset = *MaybeDataOffset;
if (DataOffset >= AccelSection.size())
return EmptyRange;
std::optional<uint32_t> StrOffset = readStringOffsetAt(DataOffset);
// Valid input and still have strings in this hash.
while (StrOffset && *StrOffset) {
std::optional<StringRef> MaybeStr = readStringFromStrSection(*StrOffset);
std::optional<uint32_t> NumEntries = this->readU32FromAccel(DataOffset);
if (!MaybeStr || !NumEntries)
return EmptyRange;
uint64_t EndOffset = DataOffset + *NumEntries * getHashDataEntryLength();
if (Key == *MaybeStr)
return make_range({*this, DataOffset},
SameNameIterator{*this, EndOffset});
DataOffset = EndOffset;
StrOffset = readStringOffsetAt(DataOffset);
}
return EmptyRange;
}
std::optional<uint32_t>
AppleAcceleratorTable::idxOfHashInBucket(uint32_t HashToFind,
uint32_t BucketIdx) const {
std::optional<uint32_t> HashStartIdx = readIthBucket(BucketIdx);
if (!HashStartIdx)
return std::nullopt;
for (uint32_t HashIdx = *HashStartIdx; HashIdx < getNumHashes(); HashIdx++) {
std::optional<uint32_t> MaybeHash = readIthHash(HashIdx);
if (!MaybeHash || !wouldHashBeInBucket(*MaybeHash, BucketIdx))
break;
if (*MaybeHash == HashToFind)
return HashIdx;
}
return std::nullopt;
}
std::optional<StringRef> AppleAcceleratorTable::readStringFromStrSection(
uint64_t StringSectionOffset) const {
Error E = Error::success();
StringRef Str = StringSection.getCStrRef(&StringSectionOffset, &E);
if (E) {
consumeError(std::move(E));
return std::nullopt;
}
return Str;
}
std::optional<uint32_t>
AppleAcceleratorTable::readU32FromAccel(uint64_t &Offset,
bool UseRelocation) const {
Error E = Error::success();
uint32_t Data = UseRelocation
? AccelSection.getRelocatedValue(4, &Offset, nullptr, &E)
: AccelSection.getU32(&Offset, &E);
if (E) {
consumeError(std::move(E));
return std::nullopt;
}
return Data;
}
void DWARFDebugNames::Header::dump(ScopedPrinter &W) const {
DictScope HeaderScope(W, "Header");
W.printHex("Length", UnitLength);
W.printString("Format", dwarf::FormatString(Format));
W.printNumber("Version", Version);
W.printNumber("CU count", CompUnitCount);
W.printNumber("Local TU count", LocalTypeUnitCount);
W.printNumber("Foreign TU count", ForeignTypeUnitCount);
W.printNumber("Bucket count", BucketCount);
W.printNumber("Name count", NameCount);
W.printHex("Abbreviations table size", AbbrevTableSize);
W.startLine() << "Augmentation: '" << AugmentationString << "'\n";
}
Error DWARFDebugNames::Header::extract(const DWARFDataExtractor &AS,
uint64_t *Offset) {
auto HeaderError = [Offset = *Offset](Error E) {
return createStringError(errc::illegal_byte_sequence,
"parsing .debug_names header at 0x%" PRIx64 ": %s",
Offset, toString(std::move(E)).c_str());
};
DataExtractor::Cursor C(*Offset);
std::tie(UnitLength, Format) = AS.getInitialLength(C);
Version = AS.getU16(C);
AS.skip(C, 2); // padding
CompUnitCount = AS.getU32(C);
LocalTypeUnitCount = AS.getU32(C);
ForeignTypeUnitCount = AS.getU32(C);
BucketCount = AS.getU32(C);
NameCount = AS.getU32(C);
AbbrevTableSize = AS.getU32(C);
AugmentationStringSize = alignTo(AS.getU32(C), 4);
if (!C)
return HeaderError(C.takeError());
if (!AS.isValidOffsetForDataOfSize(C.tell(), AugmentationStringSize))
return HeaderError(createStringError(errc::illegal_byte_sequence,
"cannot read header augmentation"));
AugmentationString.resize(AugmentationStringSize);
AS.getU8(C, reinterpret_cast<uint8_t *>(AugmentationString.data()),
AugmentationStringSize);
*Offset = C.tell();
return C.takeError();
}
void DWARFDebugNames::Abbrev::dump(ScopedPrinter &W) const {
DictScope AbbrevScope(W, ("Abbreviation 0x" + Twine::utohexstr(Code)).str());
W.startLine() << formatv("Tag: {0}\n", Tag);
for (const auto &Attr : Attributes)
W.startLine() << formatv("{0}: {1}\n", Attr.Index, Attr.Form);
}
static constexpr DWARFDebugNames::AttributeEncoding sentinelAttrEnc() {
return {dwarf::Index(0), dwarf::Form(0)};
}
static bool isSentinel(const DWARFDebugNames::AttributeEncoding &AE) {
return AE == sentinelAttrEnc();
}
static DWARFDebugNames::Abbrev sentinelAbbrev() {
return DWARFDebugNames::Abbrev(0, dwarf::Tag(0), {});
}
static bool isSentinel(const DWARFDebugNames::Abbrev &Abbr) {
return Abbr.Code == 0;
}
DWARFDebugNames::Abbrev DWARFDebugNames::AbbrevMapInfo::getEmptyKey() {
return sentinelAbbrev();
}
DWARFDebugNames::Abbrev DWARFDebugNames::AbbrevMapInfo::getTombstoneKey() {
return DWARFDebugNames::Abbrev(~0, dwarf::Tag(0), {});
}
Expected<DWARFDebugNames::AttributeEncoding>
DWARFDebugNames::NameIndex::extractAttributeEncoding(uint64_t *Offset) {
if (*Offset >= EntriesBase) {
return createStringError(errc::illegal_byte_sequence,
"Incorrectly terminated abbreviation table.");
}
uint32_t Index = Section.AccelSection.getULEB128(Offset);
uint32_t Form = Section.AccelSection.getULEB128(Offset);
return AttributeEncoding(dwarf::Index(Index), dwarf::Form(Form));
}
Expected<std::vector<DWARFDebugNames::AttributeEncoding>>
DWARFDebugNames::NameIndex::extractAttributeEncodings(uint64_t *Offset) {
std::vector<AttributeEncoding> Result;
for (;;) {
auto AttrEncOr = extractAttributeEncoding(Offset);
if (!AttrEncOr)
return AttrEncOr.takeError();
if (isSentinel(*AttrEncOr))
return std::move(Result);
Result.emplace_back(*AttrEncOr);
}
}
Expected<DWARFDebugNames::Abbrev>
DWARFDebugNames::NameIndex::extractAbbrev(uint64_t *Offset) {
if (*Offset >= EntriesBase) {
return createStringError(errc::illegal_byte_sequence,
"Incorrectly terminated abbreviation table.");
}
uint32_t Code = Section.AccelSection.getULEB128(Offset);
if (Code == 0)
return sentinelAbbrev();
uint32_t Tag = Section.AccelSection.getULEB128(Offset);
auto AttrEncOr = extractAttributeEncodings(Offset);
if (!AttrEncOr)
return AttrEncOr.takeError();
return Abbrev(Code, dwarf::Tag(Tag), std::move(*AttrEncOr));
}
Error DWARFDebugNames::NameIndex::extract() {
const DWARFDataExtractor &AS = Section.AccelSection;
uint64_t Offset = Base;
if (Error E = Hdr.extract(AS, &Offset))
return E;
const unsigned SectionOffsetSize = dwarf::getDwarfOffsetByteSize(Hdr.Format);
CUsBase = Offset;
Offset += Hdr.CompUnitCount * SectionOffsetSize;
Offset += Hdr.LocalTypeUnitCount * SectionOffsetSize;
Offset += Hdr.ForeignTypeUnitCount * 8;
BucketsBase = Offset;
Offset += Hdr.BucketCount * 4;
HashesBase = Offset;
if (Hdr.BucketCount > 0)
Offset += Hdr.NameCount * 4;
StringOffsetsBase = Offset;
Offset += Hdr.NameCount * SectionOffsetSize;
EntryOffsetsBase = Offset;
Offset += Hdr.NameCount * SectionOffsetSize;
if (!AS.isValidOffsetForDataOfSize(Offset, Hdr.AbbrevTableSize))
return createStringError(errc::illegal_byte_sequence,
"Section too small: cannot read abbreviations.");
EntriesBase = Offset + Hdr.AbbrevTableSize;
for (;;) {
auto AbbrevOr = extractAbbrev(&Offset);
if (!AbbrevOr)
return AbbrevOr.takeError();
if (isSentinel(*AbbrevOr))
return Error::success();
if (!Abbrevs.insert(std::move(*AbbrevOr)).second)
return createStringError(errc::invalid_argument,
"Duplicate abbreviation code.");
}
}
DWARFDebugNames::Entry::Entry(const NameIndex &NameIdx, const Abbrev &Abbr)
: NameIdx(&NameIdx), Abbr(&Abbr) {
// This merely creates form values. It is up to the caller
// (NameIndex::getEntry) to populate them.
Values.reserve(Abbr.Attributes.size());
for (const auto &Attr : Abbr.Attributes)
Values.emplace_back(Attr.Form);
}
std::optional<DWARFFormValue>
DWARFDebugNames::Entry::lookup(dwarf::Index Index) const {
assert(Abbr->Attributes.size() == Values.size());
for (auto Tuple : zip_first(Abbr->Attributes, Values)) {
if (std::get<0>(Tuple).Index == Index)
return std::get<1>(Tuple);
}
return std::nullopt;
}
std::optional<uint64_t> DWARFDebugNames::Entry::getDIEUnitOffset() const {
if (std::optional<DWARFFormValue> Off = lookup(dwarf::DW_IDX_die_offset))
return Off->getAsReferenceUVal();
return std::nullopt;
}
std::optional<uint64_t> DWARFDebugNames::Entry::getCUIndex() const {
if (std::optional<DWARFFormValue> Off = lookup(dwarf::DW_IDX_compile_unit))
return Off->getAsUnsignedConstant();
// In a per-CU index, the entries without a DW_IDX_compile_unit attribute
// implicitly refer to the single CU.
if (NameIdx->getCUCount() == 1)
return 0;
return std::nullopt;
}
std::optional<uint64_t> DWARFDebugNames::Entry::getCUOffset() const {
std::optional<uint64_t> Index = getCUIndex();
if (!Index || *Index >= NameIdx->getCUCount())
return std::nullopt;
return NameIdx->getCUOffset(*Index);
}
void DWARFDebugNames::Entry::dump(ScopedPrinter &W) const {
W.printHex("Abbrev", Abbr->Code);
W.startLine() << formatv("Tag: {0}\n", Abbr->Tag);
assert(Abbr->Attributes.size() == Values.size());
for (auto Tuple : zip_first(Abbr->Attributes, Values)) {
W.startLine() << formatv("{0}: ", std::get<0>(Tuple).Index);
std::get<1>(Tuple).dump(W.getOStream());
W.getOStream() << '\n';
}
}
char DWARFDebugNames::SentinelError::ID;
std::error_code DWARFDebugNames::SentinelError::convertToErrorCode() const {
return inconvertibleErrorCode();
}
uint64_t DWARFDebugNames::NameIndex::getCUOffset(uint32_t CU) const {
assert(CU < Hdr.CompUnitCount);
const unsigned SectionOffsetSize = dwarf::getDwarfOffsetByteSize(Hdr.Format);
uint64_t Offset = CUsBase + SectionOffsetSize * CU;
return Section.AccelSection.getRelocatedValue(SectionOffsetSize, &Offset);
}
uint64_t DWARFDebugNames::NameIndex::getLocalTUOffset(uint32_t TU) const {
assert(TU < Hdr.LocalTypeUnitCount);
const unsigned SectionOffsetSize = dwarf::getDwarfOffsetByteSize(Hdr.Format);
uint64_t Offset = CUsBase + SectionOffsetSize * (Hdr.CompUnitCount + TU);
return Section.AccelSection.getRelocatedValue(SectionOffsetSize, &Offset);
}
uint64_t DWARFDebugNames::NameIndex::getForeignTUSignature(uint32_t TU) const {
assert(TU < Hdr.ForeignTypeUnitCount);
const unsigned SectionOffsetSize = dwarf::getDwarfOffsetByteSize(Hdr.Format);
uint64_t Offset =
CUsBase +
SectionOffsetSize * (Hdr.CompUnitCount + Hdr.LocalTypeUnitCount) + 8 * TU;
return Section.AccelSection.getU64(&Offset);
}
Expected<DWARFDebugNames::Entry>
DWARFDebugNames::NameIndex::getEntry(uint64_t *Offset) const {
const DWARFDataExtractor &AS = Section.AccelSection;
if (!AS.isValidOffset(*Offset))
return createStringError(errc::illegal_byte_sequence,
"Incorrectly terminated entry list.");
uint32_t AbbrevCode = AS.getULEB128(Offset);
if (AbbrevCode == 0)
return make_error<SentinelError>();
const auto AbbrevIt = Abbrevs.find_as(AbbrevCode);
if (AbbrevIt == Abbrevs.end())
return createStringError(errc::invalid_argument, "Invalid abbreviation.");
Entry E(*this, *AbbrevIt);
dwarf::FormParams FormParams = {Hdr.Version, 0, Hdr.Format};
for (auto &Value : E.Values) {
if (!Value.extractValue(AS, Offset, FormParams))
return createStringError(errc::io_error,
"Error extracting index attribute values.");
}
return std::move(E);
}
DWARFDebugNames::NameTableEntry
DWARFDebugNames::NameIndex::getNameTableEntry(uint32_t Index) const {
assert(0 < Index && Index <= Hdr.NameCount);
const unsigned SectionOffsetSize = dwarf::getDwarfOffsetByteSize(Hdr.Format);
uint64_t StringOffsetOffset =
StringOffsetsBase + SectionOffsetSize * (Index - 1);
uint64_t EntryOffsetOffset =
EntryOffsetsBase + SectionOffsetSize * (Index - 1);
const DWARFDataExtractor &AS = Section.AccelSection;
uint64_t StringOffset =
AS.getRelocatedValue(SectionOffsetSize, &StringOffsetOffset);
uint64_t EntryOffset = AS.getUnsigned(&EntryOffsetOffset, SectionOffsetSize);
EntryOffset += EntriesBase;
return {Section.StringSection, Index, StringOffset, EntryOffset};
}
uint32_t
DWARFDebugNames::NameIndex::getBucketArrayEntry(uint32_t Bucket) const {
assert(Bucket < Hdr.BucketCount);
uint64_t BucketOffset = BucketsBase + 4 * Bucket;
return Section.AccelSection.getU32(&BucketOffset);
}
uint32_t DWARFDebugNames::NameIndex::getHashArrayEntry(uint32_t Index) const {
assert(0 < Index && Index <= Hdr.NameCount);
uint64_t HashOffset = HashesBase + 4 * (Index - 1);
return Section.AccelSection.getU32(&HashOffset);
}
// Returns true if we should continue scanning for entries, false if this is the
// last (sentinel) entry). In case of a parsing error we also return false, as
// it's not possible to recover this entry list (but the other lists may still
// parse OK).
bool DWARFDebugNames::NameIndex::dumpEntry(ScopedPrinter &W,
uint64_t *Offset) const {
uint64_t EntryId = *Offset;
auto EntryOr = getEntry(Offset);
if (!EntryOr) {
handleAllErrors(EntryOr.takeError(), [](const SentinelError &) {},
[&W](const ErrorInfoBase &EI) { EI.log(W.startLine()); });
return false;
}
DictScope EntryScope(W, ("Entry @ 0x" + Twine::utohexstr(EntryId)).str());
EntryOr->dump(W);
return true;
}
void DWARFDebugNames::NameIndex::dumpName(ScopedPrinter &W,
const NameTableEntry &NTE,
std::optional<uint32_t> Hash) const {
DictScope NameScope(W, ("Name " + Twine(NTE.getIndex())).str());
if (Hash)
W.printHex("Hash", *Hash);
W.startLine() << format("String: 0x%08" PRIx64, NTE.getStringOffset());
W.getOStream() << " \"" << NTE.getString() << "\"\n";
uint64_t EntryOffset = NTE.getEntryOffset();
while (dumpEntry(W, &EntryOffset))
/*empty*/;
}
void DWARFDebugNames::NameIndex::dumpCUs(ScopedPrinter &W) const {
ListScope CUScope(W, "Compilation Unit offsets");
for (uint32_t CU = 0; CU < Hdr.CompUnitCount; ++CU)
W.startLine() << format("CU[%u]: 0x%08" PRIx64 "\n", CU, getCUOffset(CU));
}
void DWARFDebugNames::NameIndex::dumpLocalTUs(ScopedPrinter &W) const {
if (Hdr.LocalTypeUnitCount == 0)
return;
ListScope TUScope(W, "Local Type Unit offsets");
for (uint32_t TU = 0; TU < Hdr.LocalTypeUnitCount; ++TU)
W.startLine() << format("LocalTU[%u]: 0x%08" PRIx64 "\n", TU,
getLocalTUOffset(TU));
}
void DWARFDebugNames::NameIndex::dumpForeignTUs(ScopedPrinter &W) const {
if (Hdr.ForeignTypeUnitCount == 0)
return;
ListScope TUScope(W, "Foreign Type Unit signatures");
for (uint32_t TU = 0; TU < Hdr.ForeignTypeUnitCount; ++TU) {
W.startLine() << format("ForeignTU[%u]: 0x%016" PRIx64 "\n", TU,
getForeignTUSignature(TU));
}
}
void DWARFDebugNames::NameIndex::dumpAbbreviations(ScopedPrinter &W) const {
ListScope AbbrevsScope(W, "Abbreviations");
for (const auto &Abbr : Abbrevs)
Abbr.dump(W);
}
void DWARFDebugNames::NameIndex::dumpBucket(ScopedPrinter &W,
uint32_t Bucket) const {
ListScope BucketScope(W, ("Bucket " + Twine(Bucket)).str());
uint32_t Index = getBucketArrayEntry(Bucket);
if (Index == 0) {
W.printString("EMPTY");
return;
}
if (Index > Hdr.NameCount) {
W.printString("Name index is invalid");
return;
}
for (; Index <= Hdr.NameCount; ++Index) {
uint32_t Hash = getHashArrayEntry(Index);
if (Hash % Hdr.BucketCount != Bucket)
break;
dumpName(W, getNameTableEntry(Index), Hash);
}
}
LLVM_DUMP_METHOD void DWARFDebugNames::NameIndex::dump(ScopedPrinter &W) const {
DictScope UnitScope(W, ("Name Index @ 0x" + Twine::utohexstr(Base)).str());
Hdr.dump(W);
dumpCUs(W);
dumpLocalTUs(W);
dumpForeignTUs(W);
dumpAbbreviations(W);
if (Hdr.BucketCount > 0) {
for (uint32_t Bucket = 0; Bucket < Hdr.BucketCount; ++Bucket)
dumpBucket(W, Bucket);
return;
}
W.startLine() << "Hash table not present\n";
for (const NameTableEntry &NTE : *this)
dumpName(W, NTE, std::nullopt);
}
Error DWARFDebugNames::extract() {
uint64_t Offset = 0;
while (AccelSection.isValidOffset(Offset)) {
NameIndex Next(*this, Offset);
if (Error E = Next.extract())
return E;
Offset = Next.getNextUnitOffset();
NameIndices.push_back(std::move(Next));
}
return Error::success();
}
iterator_range<DWARFDebugNames::ValueIterator>
DWARFDebugNames::NameIndex::equal_range(StringRef Key) const {
return make_range(ValueIterator(*this, Key), ValueIterator());
}
LLVM_DUMP_METHOD void DWARFDebugNames::dump(raw_ostream &OS) const {
ScopedPrinter W(OS);
for (const NameIndex &NI : NameIndices)
NI.dump(W);
}
std::optional<uint64_t>
DWARFDebugNames::ValueIterator::findEntryOffsetInCurrentIndex() {
const Header &Hdr = CurrentIndex->Hdr;
if (Hdr.BucketCount == 0) {
// No Hash Table, We need to search through all names in the Name Index.
for (const NameTableEntry &NTE : *CurrentIndex) {
if (NTE.getString() == Key)
return NTE.getEntryOffset();
}
return std::nullopt;
}
// The Name Index has a Hash Table, so use that to speed up the search.
// Compute the Key Hash, if it has not been done already.
if (!Hash)
Hash = caseFoldingDjbHash(Key);
uint32_t Bucket = *Hash % Hdr.BucketCount;
uint32_t Index = CurrentIndex->getBucketArrayEntry(Bucket);
if (Index == 0)
return std::nullopt; // Empty bucket
for (; Index <= Hdr.NameCount; ++Index) {
uint32_t Hash = CurrentIndex->getHashArrayEntry(Index);
if (Hash % Hdr.BucketCount != Bucket)
return std::nullopt; // End of bucket
NameTableEntry NTE = CurrentIndex->getNameTableEntry(Index);
if (NTE.getString() == Key)
return NTE.getEntryOffset();
}
return std::nullopt;
}
bool DWARFDebugNames::ValueIterator::getEntryAtCurrentOffset() {
auto EntryOr = CurrentIndex->getEntry(&DataOffset);
if (!EntryOr) {
consumeError(EntryOr.takeError());
return false;
}
CurrentEntry = std::move(*EntryOr);
return true;
}
bool DWARFDebugNames::ValueIterator::findInCurrentIndex() {
std::optional<uint64_t> Offset = findEntryOffsetInCurrentIndex();
if (!Offset)
return false;
DataOffset = *Offset;
return getEntryAtCurrentOffset();
}
void DWARFDebugNames::ValueIterator::searchFromStartOfCurrentIndex() {
for (const NameIndex *End = CurrentIndex->Section.NameIndices.end();
CurrentIndex != End; ++CurrentIndex) {
if (findInCurrentIndex())
return;
}
setEnd();
}
void DWARFDebugNames::ValueIterator::next() {
assert(CurrentIndex && "Incrementing an end() iterator?");
// First try the next entry in the current Index.
if (getEntryAtCurrentOffset())
return;
// If we're a local iterator or we have reached the last Index, we're done.
if (IsLocal || CurrentIndex == &CurrentIndex->Section.NameIndices.back()) {
setEnd();
return;
}
// Otherwise, try the next index.
++CurrentIndex;
searchFromStartOfCurrentIndex();
}
DWARFDebugNames::ValueIterator::ValueIterator(const DWARFDebugNames &AccelTable,
StringRef Key)
: CurrentIndex(AccelTable.NameIndices.begin()), IsLocal(false),
Key(std::string(Key)) {
searchFromStartOfCurrentIndex();
}
DWARFDebugNames::ValueIterator::ValueIterator(
const DWARFDebugNames::NameIndex &NI, StringRef Key)
: CurrentIndex(&NI), IsLocal(true), Key(std::string(Key)) {
if (!findInCurrentIndex())
setEnd();
}
iterator_range<DWARFDebugNames::ValueIterator>
DWARFDebugNames::equal_range(StringRef Key) const {
if (NameIndices.empty())
return make_range(ValueIterator(), ValueIterator());
return make_range(ValueIterator(*this, Key), ValueIterator());
}
const DWARFDebugNames::NameIndex *
DWARFDebugNames::getCUNameIndex(uint64_t CUOffset) {
if (CUToNameIndex.size() == 0 && NameIndices.size() > 0) {
for (const auto &NI : *this) {
for (uint32_t CU = 0; CU < NI.getCUCount(); ++CU)
CUToNameIndex.try_emplace(NI.getCUOffset(CU), &NI);
}
}
return CUToNameIndex.lookup(CUOffset);
}
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