lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp

   1 //===- DWARFAcceleratorTable.cpp ------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
  10
  11 #include "llvm/ADT/SmallVector.h"
  12 #include "llvm/BinaryFormat/Dwarf.h"
  13 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
  14 #include "llvm/Support/Compiler.h"
  15 #include "llvm/Support/DJB.h"
  16 #include "llvm/Support/Errc.h"
  17 #include "llvm/Support/Format.h"
  18 #include "llvm/Support/FormatVariadic.h"
  19 #include "llvm/Support/ScopedPrinter.h"
  20 #include "llvm/Support/raw_ostream.h"
  21 #include <cstddef>
  22 #include <cstdint>
  23 #include <utility>
  24
  25 using namespace llvm;
  26
  27 namespace {
  28 struct Atom {
  29   unsigned Value;
  30 };
  31
  32 static raw_ostream &operator<<(raw_ostream &OS, const Atom &A) {
  33   StringRef Str = dwarf::AtomTypeString(A.Value);
  34   if (!Str.empty())
  35     return OS << Str;
  36   return OS << "DW_ATOM_unknown_" << format("%x", A.Value);
  37 }
  38 } // namespace
  39
  40 static Atom formatAtom(unsigned Atom) { return {Atom}; }
  41
  42 DWARFAcceleratorTable::~DWARFAcceleratorTable() = default;
  43
  44 Error AppleAcceleratorTable::extract() {
  45   uint32_t Offset = 0;
  46
  47   // Check that we can at least read the header.
  48   if (!AccelSection.isValidOffset(offsetof(Header, HeaderDataLength) + 4))
  49     return createStringError(errc::illegal_byte_sequence,
  50                              "Section too small: cannot read header.");
  51
  52   Hdr.Magic = AccelSection.getU32(&Offset);
  53   Hdr.Version = AccelSection.getU16(&Offset);
  54   Hdr.HashFunction = AccelSection.getU16(&Offset);
  55   Hdr.BucketCount = AccelSection.getU32(&Offset);
  56   Hdr.HashCount = AccelSection.getU32(&Offset);
  57   Hdr.HeaderDataLength = AccelSection.getU32(&Offset);
  58
  59   // Check that we can read all the hashes and offsets from the
  60   // section (see SourceLevelDebugging.rst for the structure of the index).
  61   // We need to substract one because we're checking for an *offset* which is
  62   // equal to the size for an empty table and hence pointer after the section.
  63   if (!AccelSection.isValidOffset(sizeof(Hdr) + Hdr.HeaderDataLength +
  64                                   Hdr.BucketCount * 4 + Hdr.HashCount * 8 - 1))
  65     return createStringError(
  66         errc::illegal_byte_sequence,
  67         "Section too small: cannot read buckets and hashes.");
  68
  69   HdrData.DIEOffsetBase = AccelSection.getU32(&Offset);
  70   uint32_t NumAtoms = AccelSection.getU32(&Offset);
  71
  72   for (unsigned i = 0; i < NumAtoms; ++i) {
  73     uint16_t AtomType = AccelSection.getU16(&Offset);
  74     auto AtomForm = static_cast<dwarf::Form>(AccelSection.getU16(&Offset));
  75     HdrData.Atoms.push_back(std::make_pair(AtomType, AtomForm));
  76   }
  77
  78   IsValid = true;
  79   return Error::success();
  80 }
  81
  82 uint32_t AppleAcceleratorTable::getNumBuckets() { return Hdr.BucketCount; }
  83 uint32_t AppleAcceleratorTable::getNumHashes() { return Hdr.HashCount; }
  84 uint32_t AppleAcceleratorTable::getSizeHdr() { return sizeof(Hdr); }
  85 uint32_t AppleAcceleratorTable::getHeaderDataLength() {
  86   return Hdr.HeaderDataLength;
  87 }
  88
  89 ArrayRef<std::pair<AppleAcceleratorTable::HeaderData::AtomType,
  90                    AppleAcceleratorTable::HeaderData::Form>>
  91 AppleAcceleratorTable::getAtomsDesc() {
  92   return HdrData.Atoms;
  93 }
  94
  95 bool AppleAcceleratorTable::validateForms() {
  96   for (auto Atom : getAtomsDesc()) {
  97     DWARFFormValue FormValue(Atom.second);
  98     switch (Atom.first) {
  99     case dwarf::DW_ATOM_die_offset:
 100     case dwarf::DW_ATOM_die_tag:
 101     case dwarf::DW_ATOM_type_flags:
 102       if ((!FormValue.isFormClass(DWARFFormValue::FC_Constant) &&
 103            !FormValue.isFormClass(DWARFFormValue::FC_Flag)) ||
 104           FormValue.getForm() == dwarf::DW_FORM_sdata)
 105         return false;
 106       break;
 107     default:
 108       break;
 109     }
 110   }
 111   return true;
 112 }
 113
 114 std::pair<uint32_t, dwarf::Tag>
 115 AppleAcceleratorTable::readAtoms(uint32_t &HashDataOffset) {
 116   uint32_t DieOffset = dwarf::DW_INVALID_OFFSET;
 117   dwarf::Tag DieTag = dwarf::DW_TAG_null;
 118   dwarf::FormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
 119
 120   for (auto Atom : getAtomsDesc()) {
 121     DWARFFormValue FormValue(Atom.second);
 122     FormValue.extractValue(AccelSection, &HashDataOffset, FormParams);
 123     switch (Atom.first) {
 124     case dwarf::DW_ATOM_die_offset:
 125       DieOffset = *FormValue.getAsUnsignedConstant();
 126       break;
 127     case dwarf::DW_ATOM_die_tag:
 128       DieTag = (dwarf::Tag)*FormValue.getAsUnsignedConstant();
 129       break;
 130     default:
 131       break;
 132     }
 133   }
 134   return {DieOffset, DieTag};
 135 }
 136
 137 void AppleAcceleratorTable::Header::dump(ScopedPrinter &W) const {
 138   DictScope HeaderScope(W, "Header");
 139   W.printHex("Magic", Magic);
 140   W.printHex("Version", Version);
 141   W.printHex("Hash function", HashFunction);
 142   W.printNumber("Bucket count", BucketCount);
 143   W.printNumber("Hashes count", HashCount);
 144   W.printNumber("HeaderData length", HeaderDataLength);
 145 }
 146
 147 Optional<uint64_t> AppleAcceleratorTable::HeaderData::extractOffset(
 148     Optional<DWARFFormValue> Value) const {
 149   if (!Value)
 150     return None;
 151
 152   switch (Value->getForm()) {
 153   case dwarf::DW_FORM_ref1:
 154   case dwarf::DW_FORM_ref2:
 155   case dwarf::DW_FORM_ref4:
 156   case dwarf::DW_FORM_ref8:
 157   case dwarf::DW_FORM_ref_udata:
 158     return Value->getRawUValue() + DIEOffsetBase;
 159   default:
 160     return Value->getAsSectionOffset();
 161   }
 162 }
 163
 164 bool AppleAcceleratorTable::dumpName(ScopedPrinter &W,
 165                                      SmallVectorImpl<DWARFFormValue> &AtomForms,
 166                                      uint32_t *DataOffset) const {
 167   dwarf::FormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
 168   uint32_t NameOffset = *DataOffset;
 169   if (!AccelSection.isValidOffsetForDataOfSize(*DataOffset, 4)) {
 170     W.printString("Incorrectly terminated list.");
 171     return false;
 172   }
 173   unsigned StringOffset = AccelSection.getRelocatedValue(4, DataOffset);
 174   if (!StringOffset)
 175     return false; // End of list
 176
 177   DictScope NameScope(W, ("Name@0x" + Twine::utohexstr(NameOffset)).str());
 178   W.startLine() << format("String: 0x%08x", StringOffset);
 179   W.getOStream() << " \"" << StringSection.getCStr(&StringOffset) << "\"\n";
 180
 181   unsigned NumData = AccelSection.getU32(DataOffset);
 182   for (unsigned Data = 0; Data < NumData; ++Data) {
 183     ListScope DataScope(W, ("Data " + Twine(Data)).str());
 184     unsigned i = 0;
 185     for (auto &Atom : AtomForms) {
 186       W.startLine() << format("Atom[%d]: ", i);
 187       if (Atom.extractValue(AccelSection, DataOffset, FormParams)) {
 188         Atom.dump(W.getOStream());
 189         if (Optional<uint64_t> Val = Atom.getAsUnsignedConstant()) {
 190           StringRef Str = dwarf::AtomValueString(HdrData.Atoms[i].first, *Val);
 191           if (!Str.empty())
 192             W.getOStream() << " (" << Str << ")";
 193         }
 194       } else
 195         W.getOStream() << "Error extracting the value";
 196       W.getOStream() << "\n";
 197       i++;
 198     }
 199   }
 200   return true; // more entries follow
 201 }
 202
 203 LLVM_DUMP_METHOD void AppleAcceleratorTable::dump(raw_ostream &OS) const {
 204   if (!IsValid)
 205     return;
 206
 207   ScopedPrinter W(OS);
 208
 209   Hdr.dump(W);
 210
 211   W.printNumber("DIE offset base", HdrData.DIEOffsetBase);
 212   W.printNumber("Number of atoms", uint64_t(HdrData.Atoms.size()));
 213   SmallVector<DWARFFormValue, 3> AtomForms;
 214   {
 215     ListScope AtomsScope(W, "Atoms");
 216     unsigned i = 0;
 217     for (const auto &Atom : HdrData.Atoms) {
 218       DictScope AtomScope(W, ("Atom " + Twine(i++)).str());
 219       W.startLine() << "Type: " << formatAtom(Atom.first) << '\n';
 220       W.startLine() << "Form: " << formatv("{0}", Atom.second) << '\n';
 221       AtomForms.push_back(DWARFFormValue(Atom.second));
 222     }
 223   }
 224
 225   // Now go through the actual tables and dump them.
 226   uint32_t Offset = sizeof(Hdr) + Hdr.HeaderDataLength;
 227   unsigned HashesBase = Offset + Hdr.BucketCount * 4;
 228   unsigned OffsetsBase = HashesBase + Hdr.HashCount * 4;
 229
 230   for (unsigned Bucket = 0; Bucket < Hdr.BucketCount; ++Bucket) {
 231     unsigned Index = AccelSection.getU32(&Offset);
 232
 233     ListScope BucketScope(W, ("Bucket " + Twine(Bucket)).str());
 234     if (Index == UINT32_MAX) {
 235       W.printString("EMPTY");
 236       continue;
 237     }
 238
 239     for (unsigned HashIdx = Index; HashIdx < Hdr.HashCount; ++HashIdx) {
 240       unsigned HashOffset = HashesBase + HashIdx*4;
 241       unsigned OffsetsOffset = OffsetsBase + HashIdx*4;
 242       uint32_t Hash = AccelSection.getU32(&HashOffset);
 243
 244       if (Hash % Hdr.BucketCount != Bucket)
 245         break;
 246
 247       unsigned DataOffset = AccelSection.getU32(&OffsetsOffset);
 248       ListScope HashScope(W, ("Hash 0x" + Twine::utohexstr(Hash)).str());
 249       if (!AccelSection.isValidOffset(DataOffset)) {
 250         W.printString("Invalid section offset");
 251         continue;
 252       }
 253       while (dumpName(W, AtomForms, &DataOffset))
 254         /*empty*/;
 255     }
 256   }
 257 }
 258
 259 AppleAcceleratorTable::Entry::Entry(
 260     const AppleAcceleratorTable::HeaderData &HdrData)
 261     : HdrData(&HdrData) {
 262   Values.reserve(HdrData.Atoms.size());
 263   for (const auto &Atom : HdrData.Atoms)
 264     Values.push_back(DWARFFormValue(Atom.second));
 265 }
 266
 267 void AppleAcceleratorTable::Entry::extract(
 268     const AppleAcceleratorTable &AccelTable, uint32_t *Offset) {
 269
 270   dwarf::FormParams FormParams = {AccelTable.Hdr.Version, 0,
 271                                   dwarf::DwarfFormat::DWARF32};
 272   for (auto &Atom : Values)
 273     Atom.extractValue(AccelTable.AccelSection, Offset, FormParams);
 274 }
 275
 276 Optional<DWARFFormValue>
 277 AppleAcceleratorTable::Entry::lookup(HeaderData::AtomType Atom) const {
 278   assert(HdrData && "Dereferencing end iterator?");
 279   assert(HdrData->Atoms.size() == Values.size());
 280   for (const auto &Tuple : zip_first(HdrData->Atoms, Values)) {
 281     if (std::get<0>(Tuple).first == Atom)
 282       return std::get<1>(Tuple);
 283   }
 284   return None;
 285 }
 286
 287 Optional<uint64_t> AppleAcceleratorTable::Entry::getDIESectionOffset() const {
 288   return HdrData->extractOffset(lookup(dwarf::DW_ATOM_die_offset));
 289 }
 290
 291 Optional<uint64_t> AppleAcceleratorTable::Entry::getCUOffset() const {
 292   return HdrData->extractOffset(lookup(dwarf::DW_ATOM_cu_offset));
 293 }
 294
 295 Optional<dwarf::Tag> AppleAcceleratorTable::Entry::getTag() const {
 296   Optional<DWARFFormValue> Tag = lookup(dwarf::DW_ATOM_die_tag);
 297   if (!Tag)
 298     return None;
 299   if (Optional<uint64_t> Value = Tag->getAsUnsignedConstant())
 300     return dwarf::Tag(*Value);
 301   return None;
 302 }
 303
 304 AppleAcceleratorTable::ValueIterator::ValueIterator(
 305     const AppleAcceleratorTable &AccelTable, unsigned Offset)
 306     : AccelTable(&AccelTable), Current(AccelTable.HdrData), DataOffset(Offset) {
 307   if (!AccelTable.AccelSection.isValidOffsetForDataOfSize(DataOffset, 4))
 308     return;
 309
 310   // Read the first entry.
 311   NumData = AccelTable.AccelSection.getU32(&DataOffset);
 312   Next();
 313 }
 314
 315 void AppleAcceleratorTable::ValueIterator::Next() {
 316   assert(NumData > 0 && "attempted to increment iterator past the end");
 317   auto &AccelSection = AccelTable->AccelSection;
 318   if (Data >= NumData ||
 319       !AccelSection.isValidOffsetForDataOfSize(DataOffset, 4)) {
 320     NumData = 0;
 321     DataOffset = 0;
 322     return;
 323   }
 324   Current.extract(*AccelTable, &DataOffset);
 325   ++Data;
 326 }
 327
 328 iterator_range<AppleAcceleratorTable::ValueIterator>
 329 AppleAcceleratorTable::equal_range(StringRef Key) const {
 330   if (!IsValid)
 331     return make_range(ValueIterator(), ValueIterator());
 332
 333   // Find the bucket.
 334   unsigned HashValue = djbHash(Key);
 335   unsigned Bucket = HashValue % Hdr.BucketCount;
 336   unsigned BucketBase = sizeof(Hdr) + Hdr.HeaderDataLength;
 337   unsigned HashesBase = BucketBase + Hdr.BucketCount * 4;
 338   unsigned OffsetsBase = HashesBase + Hdr.HashCount * 4;
 339
 340   unsigned BucketOffset = BucketBase + Bucket * 4;
 341   unsigned Index = AccelSection.getU32(&BucketOffset);
 342
 343   // Search through all hashes in the bucket.
 344   for (unsigned HashIdx = Index; HashIdx < Hdr.HashCount; ++HashIdx) {
 345     unsigned HashOffset = HashesBase + HashIdx * 4;
 346     unsigned OffsetsOffset = OffsetsBase + HashIdx * 4;
 347     uint32_t Hash = AccelSection.getU32(&HashOffset);
 348
 349     if (Hash % Hdr.BucketCount != Bucket)
 350       // We are already in the next bucket.
 351       break;
 352
 353     unsigned DataOffset = AccelSection.getU32(&OffsetsOffset);
 354     unsigned StringOffset = AccelSection.getRelocatedValue(4, &DataOffset);
 355     if (!StringOffset)
 356       break;
 357
 358     // Finally, compare the key.
 359     if (Key == StringSection.getCStr(&StringOffset))
 360       return make_range({*this, DataOffset}, ValueIterator());
 361   }
 362   return make_range(ValueIterator(), ValueIterator());
 363 }
 364
 365 void DWARFDebugNames::Header::dump(ScopedPrinter &W) const {
 366   DictScope HeaderScope(W, "Header");
 367   W.printHex("Length", UnitLength);
 368   W.printNumber("Version", Version);
 369   W.printHex("Padding", Padding);
 370   W.printNumber("CU count", CompUnitCount);
 371   W.printNumber("Local TU count", LocalTypeUnitCount);
 372   W.printNumber("Foreign TU count", ForeignTypeUnitCount);
 373   W.printNumber("Bucket count", BucketCount);
 374   W.printNumber("Name count", NameCount);
 375   W.printHex("Abbreviations table size", AbbrevTableSize);
 376   W.startLine() << "Augmentation: '" << AugmentationString << "'\n";
 377 }
 378
 379 Error DWARFDebugNames::Header::extract(const DWARFDataExtractor &AS,
 380                                              uint32_t *Offset) {
 381   // Check that we can read the fixed-size part.
 382   if (!AS.isValidOffset(*Offset + sizeof(HeaderPOD) - 1))
 383     return createStringError(errc::illegal_byte_sequence,
 384                              "Section too small: cannot read header.");
 385
 386   UnitLength = AS.getU32(Offset);
 387   Version = AS.getU16(Offset);
 388   Padding = AS.getU16(Offset);
 389   CompUnitCount = AS.getU32(Offset);
 390   LocalTypeUnitCount = AS.getU32(Offset);
 391   ForeignTypeUnitCount = AS.getU32(Offset);
 392   BucketCount = AS.getU32(Offset);
 393   NameCount = AS.getU32(Offset);
 394   AbbrevTableSize = AS.getU32(Offset);
 395   AugmentationStringSize = alignTo(AS.getU32(Offset), 4);
 396
 397   if (!AS.isValidOffsetForDataOfSize(*Offset, AugmentationStringSize))
 398     return createStringError(
 399         errc::illegal_byte_sequence,
 400         "Section too small: cannot read header augmentation.");
 401   AugmentationString.resize(AugmentationStringSize);
 402   AS.getU8(Offset, reinterpret_cast<uint8_t *>(AugmentationString.data()),
 403            AugmentationStringSize);
 404   return Error::success();
 405 }
 406
 407 void DWARFDebugNames::Abbrev::dump(ScopedPrinter &W) const {
 408   DictScope AbbrevScope(W, ("Abbreviation 0x" + Twine::utohexstr(Code)).str());
 409   W.startLine() << formatv("Tag: {0}\n", Tag);
 410
 411   for (const auto &Attr : Attributes)
 412     W.startLine() << formatv("{0}: {1}\n", Attr.Index, Attr.Form);
 413 }
 414
 415 static constexpr DWARFDebugNames::AttributeEncoding sentinelAttrEnc() {
 416   return {dwarf::Index(0), dwarf::Form(0)};
 417 }
 418
 419 static bool isSentinel(const DWARFDebugNames::AttributeEncoding &AE) {
 420   return AE == sentinelAttrEnc();
 421 }
 422
 423 static DWARFDebugNames::Abbrev sentinelAbbrev() {
 424   return DWARFDebugNames::Abbrev(0, dwarf::Tag(0), {});
 425 }
 426
 427 static bool isSentinel(const DWARFDebugNames::Abbrev &Abbr) {
 428   return Abbr.Code == 0;
 429 }
 430
 431 DWARFDebugNames::Abbrev DWARFDebugNames::AbbrevMapInfo::getEmptyKey() {
 432   return sentinelAbbrev();
 433 }
 434
 435 DWARFDebugNames::Abbrev DWARFDebugNames::AbbrevMapInfo::getTombstoneKey() {
 436   return DWARFDebugNames::Abbrev(~0, dwarf::Tag(0), {});
 437 }
 438
 439 Expected<DWARFDebugNames::AttributeEncoding>
 440 DWARFDebugNames::NameIndex::extractAttributeEncoding(uint32_t *Offset) {
 441   if (*Offset >= EntriesBase) {
 442     return createStringError(errc::illegal_byte_sequence,
 443                              "Incorrectly terminated abbreviation table.");
 444   }
 445
 446   uint32_t Index = Section.AccelSection.getULEB128(Offset);
 447   uint32_t Form = Section.AccelSection.getULEB128(Offset);
 448   return AttributeEncoding(dwarf::Index(Index), dwarf::Form(Form));
 449 }
 450
 451 Expected<std::vector<DWARFDebugNames::AttributeEncoding>>
 452 DWARFDebugNames::NameIndex::extractAttributeEncodings(uint32_t *Offset) {
 453   std::vector<AttributeEncoding> Result;
 454   for (;;) {
 455     auto AttrEncOr = extractAttributeEncoding(Offset);
 456     if (!AttrEncOr)
 457       return AttrEncOr.takeError();
 458     if (isSentinel(*AttrEncOr))
 459       return std::move(Result);
 460
 461     Result.emplace_back(*AttrEncOr);
 462   }
 463 }
 464
 465 Expected<DWARFDebugNames::Abbrev>
 466 DWARFDebugNames::NameIndex::extractAbbrev(uint32_t *Offset) {
 467   if (*Offset >= EntriesBase) {
 468     return createStringError(errc::illegal_byte_sequence,
 469                              "Incorrectly terminated abbreviation table.");
 470   }
 471
 472   uint32_t Code = Section.AccelSection.getULEB128(Offset);
 473   if (Code == 0)
 474     return sentinelAbbrev();
 475
 476   uint32_t Tag = Section.AccelSection.getULEB128(Offset);
 477   auto AttrEncOr = extractAttributeEncodings(Offset);
 478   if (!AttrEncOr)
 479     return AttrEncOr.takeError();
 480   return Abbrev(Code, dwarf::Tag(Tag), std::move(*AttrEncOr));
 481 }
 482
 483 Error DWARFDebugNames::NameIndex::extract() {
 484   const DWARFDataExtractor &AS = Section.AccelSection;
 485   uint32_t Offset = Base;
 486   if (Error E = Hdr.extract(AS, &Offset))
 487     return E;
 488
 489   CUsBase = Offset;
 490   Offset += Hdr.CompUnitCount * 4;
 491   Offset += Hdr.LocalTypeUnitCount * 4;
 492   Offset += Hdr.ForeignTypeUnitCount * 8;
 493   BucketsBase = Offset;
 494   Offset += Hdr.BucketCount * 4;
 495   HashesBase = Offset;
 496   if (Hdr.BucketCount > 0)
 497     Offset += Hdr.NameCount * 4;
 498   StringOffsetsBase = Offset;
 499   Offset += Hdr.NameCount * 4;
 500   EntryOffsetsBase = Offset;
 501   Offset += Hdr.NameCount * 4;
 502
 503   if (!AS.isValidOffsetForDataOfSize(Offset, Hdr.AbbrevTableSize))
 504     return createStringError(errc::illegal_byte_sequence,
 505                              "Section too small: cannot read abbreviations.");
 506
 507   EntriesBase = Offset + Hdr.AbbrevTableSize;
 508
 509   for (;;) {
 510     auto AbbrevOr = extractAbbrev(&Offset);
 511     if (!AbbrevOr)
 512       return AbbrevOr.takeError();
 513     if (isSentinel(*AbbrevOr))
 514       return Error::success();
 515
 516     if (!Abbrevs.insert(std::move(*AbbrevOr)).second)
 517       return createStringError(errc::invalid_argument,
 518                                "Duplicate abbreviation code.");
 519   }
 520 }
 521
 522 DWARFDebugNames::Entry::Entry(const NameIndex &NameIdx, const Abbrev &Abbr)
 523     : NameIdx(&NameIdx), Abbr(&Abbr) {
 524   // This merely creates form values. It is up to the caller
 525   // (NameIndex::getEntry) to populate them.
 526   Values.reserve(Abbr.Attributes.size());
 527   for (const auto &Attr : Abbr.Attributes)
 528     Values.emplace_back(Attr.Form);
 529 }
 530
 531 Optional<DWARFFormValue>
 532 DWARFDebugNames::Entry::lookup(dwarf::Index Index) const {
 533   assert(Abbr->Attributes.size() == Values.size());
 534   for (const auto &Tuple : zip_first(Abbr->Attributes, Values)) {
 535     if (std::get<0>(Tuple).Index == Index)
 536       return std::get<1>(Tuple);
 537   }
 538   return None;
 539 }
 540
 541 Optional<uint64_t> DWARFDebugNames::Entry::getDIEUnitOffset() const {
 542   if (Optional<DWARFFormValue> Off = lookup(dwarf::DW_IDX_die_offset))
 543     return Off->getAsReferenceUVal();
 544   return None;
 545 }
 546
 547 Optional<uint64_t> DWARFDebugNames::Entry::getCUIndex() const {
 548   if (Optional<DWARFFormValue> Off = lookup(dwarf::DW_IDX_compile_unit))
 549     return Off->getAsUnsignedConstant();
 550   // In a per-CU index, the entries without a DW_IDX_compile_unit attribute
 551   // implicitly refer to the single CU.
 552   if (NameIdx->getCUCount() == 1)
 553     return 0;
 554   return None;
 555 }
 556
 557 Optional<uint64_t> DWARFDebugNames::Entry::getCUOffset() const {
 558   Optional<uint64_t> Index = getCUIndex();
 559   if (!Index || *Index >= NameIdx->getCUCount())
 560     return None;
 561   return NameIdx->getCUOffset(*Index);
 562 }
 563
 564 void DWARFDebugNames::Entry::dump(ScopedPrinter &W) const {
 565   W.printHex("Abbrev", Abbr->Code);
 566   W.startLine() << formatv("Tag: {0}\n", Abbr->Tag);
 567   assert(Abbr->Attributes.size() == Values.size());
 568   for (const auto &Tuple : zip_first(Abbr->Attributes, Values)) {
 569     W.startLine() << formatv("{0}: ", std::get<0>(Tuple).Index);
 570     std::get<1>(Tuple).dump(W.getOStream());
 571     W.getOStream() << '\n';
 572   }
 573 }
 574
 575 char DWARFDebugNames::SentinelError::ID;
 576 std::error_code DWARFDebugNames::SentinelError::convertToErrorCode() const {
 577   return inconvertibleErrorCode();
 578 }
 579
 580 uint32_t DWARFDebugNames::NameIndex::getCUOffset(uint32_t CU) const {
 581   assert(CU < Hdr.CompUnitCount);
 582   uint32_t Offset = CUsBase + 4 * CU;
 583   return Section.AccelSection.getRelocatedValue(4, &Offset);
 584 }
 585
 586 uint32_t DWARFDebugNames::NameIndex::getLocalTUOffset(uint32_t TU) const {
 587   assert(TU < Hdr.LocalTypeUnitCount);
 588   uint32_t Offset = CUsBase + 4 * (Hdr.CompUnitCount + TU);
 589   return Section.AccelSection.getRelocatedValue(4, &Offset);
 590 }
 591
 592 uint64_t DWARFDebugNames::NameIndex::getForeignTUSignature(uint32_t TU) const {
 593   assert(TU < Hdr.ForeignTypeUnitCount);
 594   uint32_t Offset =
 595       CUsBase + 4 * (Hdr.CompUnitCount + Hdr.LocalTypeUnitCount) + 8 * TU;
 596   return Section.AccelSection.getU64(&Offset);
 597 }
 598
 599 Expected<DWARFDebugNames::Entry>
 600 DWARFDebugNames::NameIndex::getEntry(uint32_t *Offset) const {
 601   const DWARFDataExtractor &AS = Section.AccelSection;
 602   if (!AS.isValidOffset(*Offset))
 603     return createStringError(errc::illegal_byte_sequence,
 604                              "Incorrectly terminated entry list.");
 605
 606   uint32_t AbbrevCode = AS.getULEB128(Offset);
 607   if (AbbrevCode == 0)
 608     return make_error<SentinelError>();
 609
 610   const auto AbbrevIt = Abbrevs.find_as(AbbrevCode);
 611   if (AbbrevIt == Abbrevs.end())
 612     return createStringError(errc::invalid_argument, "Invalid abbreviation.");
 613
 614   Entry E(*this, *AbbrevIt);
 615
 616   dwarf::FormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
 617   for (auto &Value : E.Values) {
 618     if (!Value.extractValue(AS, Offset, FormParams))
 619       return createStringError(errc::io_error,
 620                                "Error extracting index attribute values.");
 621   }
 622   return std::move(E);
 623 }
 624
 625 DWARFDebugNames::NameTableEntry
 626 DWARFDebugNames::NameIndex::getNameTableEntry(uint32_t Index) const {
 627   assert(0 < Index && Index <= Hdr.NameCount);
 628   uint32_t StringOffsetOffset = StringOffsetsBase + 4 * (Index - 1);
 629   uint32_t EntryOffsetOffset = EntryOffsetsBase + 4 * (Index - 1);
 630   const DWARFDataExtractor &AS = Section.AccelSection;
 631
 632   uint32_t StringOffset = AS.getRelocatedValue(4, &StringOffsetOffset);
 633   uint32_t EntryOffset = AS.getU32(&EntryOffsetOffset);
 634   EntryOffset += EntriesBase;
 635   return {Section.StringSection, Index, StringOffset, EntryOffset};
 636 }
 637
 638 uint32_t
 639 DWARFDebugNames::NameIndex::getBucketArrayEntry(uint32_t Bucket) const {
 640   assert(Bucket < Hdr.BucketCount);
 641   uint32_t BucketOffset = BucketsBase + 4 * Bucket;
 642   return Section.AccelSection.getU32(&BucketOffset);
 643 }
 644
 645 uint32_t DWARFDebugNames::NameIndex::getHashArrayEntry(uint32_t Index) const {
 646   assert(0 < Index && Index <= Hdr.NameCount);
 647   uint32_t HashOffset = HashesBase + 4 * (Index - 1);
 648   return Section.AccelSection.getU32(&HashOffset);
 649 }
 650
 651 // Returns true if we should continue scanning for entries, false if this is the
 652 // last (sentinel) entry). In case of a parsing error we also return false, as
 653 // it's not possible to recover this entry list (but the other lists may still
 654 // parse OK).
 655 bool DWARFDebugNames::NameIndex::dumpEntry(ScopedPrinter &W,
 656                                            uint32_t *Offset) const {
 657   uint32_t EntryId = *Offset;
 658   auto EntryOr = getEntry(Offset);
 659   if (!EntryOr) {
 660     handleAllErrors(EntryOr.takeError(), [](const SentinelError &) {},
 661                     [&W](const ErrorInfoBase &EI) { EI.log(W.startLine()); });
 662     return false;
 663   }
 664
 665   DictScope EntryScope(W, ("Entry @ 0x" + Twine::utohexstr(EntryId)).str());
 666   EntryOr->dump(W);
 667   return true;
 668 }
 669
 670 void DWARFDebugNames::NameIndex::dumpName(ScopedPrinter &W,
 671                                           const NameTableEntry &NTE,
 672                                           Optional<uint32_t> Hash) const {
 673   DictScope NameScope(W, ("Name " + Twine(NTE.getIndex())).str());
 674   if (Hash)
 675     W.printHex("Hash", *Hash);
 676
 677   W.startLine() << format("String: 0x%08x", NTE.getStringOffset());
 678   W.getOStream() << " \"" << NTE.getString() << "\"\n";
 679
 680   uint32_t EntryOffset = NTE.getEntryOffset();
 681   while (dumpEntry(W, &EntryOffset))
 682     /*empty*/;
 683 }
 684
 685 void DWARFDebugNames::NameIndex::dumpCUs(ScopedPrinter &W) const {
 686   ListScope CUScope(W, "Compilation Unit offsets");
 687   for (uint32_t CU = 0; CU < Hdr.CompUnitCount; ++CU)
 688     W.startLine() << format("CU[%u]: 0x%08x\n", CU, getCUOffset(CU));
 689 }
 690
 691 void DWARFDebugNames::NameIndex::dumpLocalTUs(ScopedPrinter &W) const {
 692   if (Hdr.LocalTypeUnitCount == 0)
 693     return;
 694
 695   ListScope TUScope(W, "Local Type Unit offsets");
 696   for (uint32_t TU = 0; TU < Hdr.LocalTypeUnitCount; ++TU)
 697     W.startLine() << format("LocalTU[%u]: 0x%08x\n", TU, getLocalTUOffset(TU));
 698 }
 699
 700 void DWARFDebugNames::NameIndex::dumpForeignTUs(ScopedPrinter &W) const {
 701   if (Hdr.ForeignTypeUnitCount == 0)
 702     return;
 703
 704   ListScope TUScope(W, "Foreign Type Unit signatures");
 705   for (uint32_t TU = 0; TU < Hdr.ForeignTypeUnitCount; ++TU) {
 706     W.startLine() << format("ForeignTU[%u]: 0x%016" PRIx64 "\n", TU,
 707                             getForeignTUSignature(TU));
 708   }
 709 }
 710
 711 void DWARFDebugNames::NameIndex::dumpAbbreviations(ScopedPrinter &W) const {
 712   ListScope AbbrevsScope(W, "Abbreviations");
 713   for (const auto &Abbr : Abbrevs)
 714     Abbr.dump(W);
 715 }
 716
 717 void DWARFDebugNames::NameIndex::dumpBucket(ScopedPrinter &W,
 718                                             uint32_t Bucket) const {
 719   ListScope BucketScope(W, ("Bucket " + Twine(Bucket)).str());
 720   uint32_t Index = getBucketArrayEntry(Bucket);
 721   if (Index == 0) {
 722     W.printString("EMPTY");
 723     return;
 724   }
 725   if (Index > Hdr.NameCount) {
 726     W.printString("Name index is invalid");
 727     return;
 728   }
 729
 730   for (; Index <= Hdr.NameCount; ++Index) {
 731     uint32_t Hash = getHashArrayEntry(Index);
 732     if (Hash % Hdr.BucketCount != Bucket)
 733       break;
 734
 735     dumpName(W, getNameTableEntry(Index), Hash);
 736   }
 737 }
 738
 739 LLVM_DUMP_METHOD void DWARFDebugNames::NameIndex::dump(ScopedPrinter &W) const {
 740   DictScope UnitScope(W, ("Name Index @ 0x" + Twine::utohexstr(Base)).str());
 741   Hdr.dump(W);
 742   dumpCUs(W);
 743   dumpLocalTUs(W);
 744   dumpForeignTUs(W);
 745   dumpAbbreviations(W);
 746
 747   if (Hdr.BucketCount > 0) {
 748     for (uint32_t Bucket = 0; Bucket < Hdr.BucketCount; ++Bucket)
 749       dumpBucket(W, Bucket);
 750     return;
 751   }
 752
 753   W.startLine() << "Hash table not present\n";
 754   for (NameTableEntry NTE : *this)
 755     dumpName(W, NTE, None);
 756 }
 757
 758 Error DWARFDebugNames::extract() {
 759   uint32_t Offset = 0;
 760   while (AccelSection.isValidOffset(Offset)) {
 761     NameIndex Next(*this, Offset);
 762     if (Error E = Next.extract())
 763       return E;
 764     Offset = Next.getNextUnitOffset();
 765     NameIndices.push_back(std::move(Next));
 766   }
 767   return Error::success();
 768 }
 769
 770 iterator_range<DWARFDebugNames::ValueIterator>
 771 DWARFDebugNames::NameIndex::equal_range(StringRef Key) const {
 772   return make_range(ValueIterator(*this, Key), ValueIterator());
 773 }
 774
 775 LLVM_DUMP_METHOD void DWARFDebugNames::dump(raw_ostream &OS) const {
 776   ScopedPrinter W(OS);
 777   for (const NameIndex &NI : NameIndices)
 778     NI.dump(W);
 779 }
 780
 781 Optional<uint32_t>
 782 DWARFDebugNames::ValueIterator::findEntryOffsetInCurrentIndex() {
 783   const Header &Hdr = CurrentIndex->Hdr;
 784   if (Hdr.BucketCount == 0) {
 785     // No Hash Table, We need to search through all names in the Name Index.
 786     for (NameTableEntry NTE : *CurrentIndex) {
 787       if (NTE.getString() == Key)
 788         return NTE.getEntryOffset();
 789     }
 790     return None;
 791   }
 792
 793   // The Name Index has a Hash Table, so use that to speed up the search.
 794   // Compute the Key Hash, if it has not been done already.
 795   if (!Hash)
 796     Hash = caseFoldingDjbHash(Key);
 797   uint32_t Bucket = *Hash % Hdr.BucketCount;
 798   uint32_t Index = CurrentIndex->getBucketArrayEntry(Bucket);
 799   if (Index == 0)
 800     return None; // Empty bucket
 801
 802   for (; Index <= Hdr.NameCount; ++Index) {
 803     uint32_t Hash = CurrentIndex->getHashArrayEntry(Index);
 804     if (Hash % Hdr.BucketCount != Bucket)
 805       return None; // End of bucket
 806
 807     NameTableEntry NTE = CurrentIndex->getNameTableEntry(Index);
 808     if (NTE.getString() == Key)
 809       return NTE.getEntryOffset();
 810   }
 811   return None;
 812 }
 813
 814 bool DWARFDebugNames::ValueIterator::getEntryAtCurrentOffset() {
 815   auto EntryOr = CurrentIndex->getEntry(&DataOffset);
 816   if (!EntryOr) {
 817     consumeError(EntryOr.takeError());
 818     return false;
 819   }
 820   CurrentEntry = std::move(*EntryOr);
 821   return true;
 822 }
 823
 824 bool DWARFDebugNames::ValueIterator::findInCurrentIndex() {
 825   Optional<uint32_t> Offset = findEntryOffsetInCurrentIndex();
 826   if (!Offset)
 827     return false;
 828   DataOffset = *Offset;
 829   return getEntryAtCurrentOffset();
 830 }
 831
 832 void DWARFDebugNames::ValueIterator::searchFromStartOfCurrentIndex() {
 833   for (const NameIndex *End = CurrentIndex->Section.NameIndices.end();
 834        CurrentIndex != End; ++CurrentIndex) {
 835     if (findInCurrentIndex())
 836       return;
 837   }
 838   setEnd();
 839 }
 840
 841 void DWARFDebugNames::ValueIterator::next() {
 842   assert(CurrentIndex && "Incrementing an end() iterator?");
 843
 844   // First try the next entry in the current Index.
 845   if (getEntryAtCurrentOffset())
 846     return;
 847
 848   // If we're a local iterator or we have reached the last Index, we're done.
 849   if (IsLocal || CurrentIndex == &CurrentIndex->Section.NameIndices.back()) {
 850     setEnd();
 851     return;
 852   }
 853
 854   // Otherwise, try the next index.
 855   ++CurrentIndex;
 856   searchFromStartOfCurrentIndex();
 857 }
 858
 859 DWARFDebugNames::ValueIterator::ValueIterator(const DWARFDebugNames &AccelTable,
 860                                               StringRef Key)
 861     : CurrentIndex(AccelTable.NameIndices.begin()), IsLocal(false), Key(Key) {
 862   searchFromStartOfCurrentIndex();
 863 }
 864
 865 DWARFDebugNames::ValueIterator::ValueIterator(
 866     const DWARFDebugNames::NameIndex &NI, StringRef Key)
 867     : CurrentIndex(&NI), IsLocal(true), Key(Key) {
 868   if (!findInCurrentIndex())
 869     setEnd();
 870 }
 871
 872 iterator_range<DWARFDebugNames::ValueIterator>
 873 DWARFDebugNames::equal_range(StringRef Key) const {
 874   if (NameIndices.empty())
 875     return make_range(ValueIterator(), ValueIterator());
 876   return make_range(ValueIterator(*this, Key), ValueIterator());
 877 }
 878
 879 const DWARFDebugNames::NameIndex *
 880 DWARFDebugNames::getCUNameIndex(uint32_t CUOffset) {
 881   if (CUToNameIndex.size() == 0 && NameIndices.size() > 0) {
 882     for (const auto &NI : *this) {
 883       for (uint32_t CU = 0; CU < NI.getCUCount(); ++CU)
 884         CUToNameIndex.try_emplace(NI.getCUOffset(CU), &NI);
 885     }
 886   }
 887   return CUToNameIndex.lookup(CUOffset);
 888 }