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1//===-- DWARFDebugInfoEntry.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-exception6//7//===----------------------------------------------------------------------===//8 9#include "DWARFDebugInfoEntry.h"10 11#include <cassert>12 13#include <algorithm>14#include <limits>15#include <optional>16 17#include "LogChannelDWARF.h"18#include "lldb/Core/Module.h"19#include "lldb/Expression/DWARFExpression.h"20#include "lldb/Symbol/ObjectFile.h"21#include "llvm/ADT/STLExtras.h"22#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"23#include "llvm/Support/Error.h"24#include "llvm/Support/FormatAdapters.h"25#include "llvm/Support/LEB128.h"26 27#include "DWARFCompileUnit.h"28#include "DWARFDebugAranges.h"29#include "DWARFDebugInfo.h"30#include "DWARFDeclContext.h"31#include "DWARFFormValue.h"32#include "DWARFUnit.h"33#include "SymbolFileDWARF.h"34#include "SymbolFileDWARFDwo.h"35 36using namespace lldb_private;37using namespace lldb_private::plugin::dwarf;38using namespace llvm::dwarf;39extern int g_verbose;40 41// Extract a debug info entry for a given DWARFUnit from the data42// starting at the offset in offset_ptr43bool DWARFDebugInfoEntry::Extract(const DWARFDataExtractor &data,44                                  const DWARFUnit &unit,45                                  lldb::offset_t *offset_ptr) {46  m_offset = *offset_ptr;47  auto report_error = [&](const char *fmt, const auto &...vals) {48    unit.GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(49        "[{0:x16}]: {1}, please file a bug and "50        "attach the file at the start of this error message",51        static_cast<uint64_t>(m_offset), llvm::formatv(fmt, vals...));52    *offset_ptr = std::numeric_limits<lldb::offset_t>::max();53    return false;54  };55 56  m_parent_idx = 0;57  m_sibling_idx = 0;58  const uint64_t abbr_idx = data.GetULEB128(offset_ptr);59  if (abbr_idx > std::numeric_limits<uint16_t>::max())60    return report_error("abbreviation code {0} too big", abbr_idx);61  m_abbr_idx = abbr_idx;62 63  if (m_abbr_idx == 0) {64    m_tag = llvm::dwarf::DW_TAG_null;65    m_has_children = false;66    return true; // NULL debug tag entry67  }68 69  const auto *abbrevDecl = GetAbbreviationDeclarationPtr(&unit);70  if (abbrevDecl == nullptr)71    return report_error("invalid abbreviation code {0}", abbr_idx);72 73  m_tag = abbrevDecl->getTag();74  m_has_children = abbrevDecl->hasChildren();75  // Skip all data in the .debug_info or .debug_types for the attributes76  for (const auto &attribute : abbrevDecl->attributes()) {77    if (DWARFFormValue::SkipValue(attribute.Form, data, offset_ptr, &unit))78      continue;79 80    return report_error("Unsupported DW_FORM_{1:x}", attribute.Form);81  }82  return true;83}84 85static llvm::Expected<llvm::DWARFAddressRangesVector>86GetRanges(DWARFUnit &unit, const DWARFFormValue &value) {87  return (value.Form() == DW_FORM_rnglistx)88             ? unit.FindRnglistFromIndex(value.Unsigned())89             : unit.FindRnglistFromOffset(value.Unsigned());90}91 92static void ExtractAttrAndFormValue(93    const llvm::DWARFAbbreviationDeclaration::AttributeSpec &attr_spec,94    dw_attr_t &attr, DWARFFormValue &form_value) {95  attr = attr_spec.Attr;96  form_value.FormRef() = attr_spec.Form;97  if (attr_spec.isImplicitConst())98    form_value.SetSigned(attr_spec.getImplicitConstValue());99}100 101// GetDIENamesAndRanges102//103// Gets the valid address ranges for a given DIE by looking for a104// DW_AT_low_pc/DW_AT_high_pc pair, DW_AT_entry_pc, or DW_AT_ranges attributes.105bool DWARFDebugInfoEntry::GetDIENamesAndRanges(106    DWARFUnit *cu, const char *&name, const char *&mangled,107    llvm::DWARFAddressRangesVector &ranges, std::optional<int> &decl_file,108    std::optional<int> &decl_line, std::optional<int> &decl_column,109    std::optional<int> &call_file, std::optional<int> &call_line,110    std::optional<int> &call_column, DWARFExpressionList *frame_base) const {111  dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;112  dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;113  std::vector<DWARFDIE> dies;114  bool set_frame_base_loclist_addr = false;115 116  SymbolFileDWARF &dwarf = cu->GetSymbolFileDWARF();117  lldb::ModuleSP module = dwarf.GetObjectFile()->GetModule();118 119  if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {120    const DWARFDataExtractor &data = cu->GetData();121    lldb::offset_t offset = GetFirstAttributeOffset();122 123    if (!data.ValidOffset(offset))124      return false;125 126    bool do_offset = false;127 128    for (const auto &attribute : abbrevDecl->attributes()) {129      DWARFFormValue form_value(cu);130      dw_attr_t attr;131      ExtractAttrAndFormValue(attribute, attr, form_value);132 133      if (form_value.ExtractValue(data, &offset)) {134        switch (attr) {135        case DW_AT_low_pc:136          lo_pc = form_value.Address();137 138          if (do_offset)139            hi_pc += lo_pc;140          do_offset = false;141          break;142 143        case DW_AT_entry_pc:144          lo_pc = form_value.Address();145          break;146 147        case DW_AT_high_pc:148          if (form_value.Form() == DW_FORM_addr ||149              form_value.Form() == DW_FORM_addrx ||150              form_value.Form() == DW_FORM_GNU_addr_index) {151            hi_pc = form_value.Address();152          } else {153            hi_pc = form_value.Unsigned();154            if (lo_pc == LLDB_INVALID_ADDRESS)155              do_offset = hi_pc != LLDB_INVALID_ADDRESS;156            else157              hi_pc += lo_pc; // DWARF 4 introduces <offset-from-lo-pc> to save158                              // on relocations159          }160          break;161 162        case DW_AT_ranges:163          if (llvm::Expected<llvm::DWARFAddressRangesVector> r =164                  GetRanges(*cu, form_value)) {165            ranges = std::move(*r);166          } else {167            module->ReportError(168                "[{0:x16}]: DIE has DW_AT_ranges({1} {2:x16}) attribute, but "169                "range extraction failed ({3}), please file a bug "170                "and attach the file at the start of this error message",171                GetOffset(), llvm::dwarf::FormEncodingString(form_value.Form()),172                form_value.Unsigned(), fmt_consume(r.takeError()));173          }174          break;175 176        case DW_AT_name:177          if (name == nullptr)178            name = form_value.AsCString();179          break;180 181        case DW_AT_MIPS_linkage_name:182        case DW_AT_linkage_name:183          if (mangled == nullptr)184            mangled = form_value.AsCString();185          break;186 187        case DW_AT_abstract_origin:188          dies.push_back(form_value.Reference());189          break;190 191        case DW_AT_specification:192          dies.push_back(form_value.Reference());193          break;194 195        case DW_AT_decl_file:196          if (!decl_file)197            decl_file = form_value.Unsigned();198          break;199 200        case DW_AT_decl_line:201          if (!decl_line)202            decl_line = form_value.Unsigned();203          break;204 205        case DW_AT_decl_column:206          if (!decl_column)207            decl_column = form_value.Unsigned();208          break;209 210        case DW_AT_call_file:211          if (!call_file)212            call_file = form_value.Unsigned();213          break;214 215        case DW_AT_call_line:216          if (!call_line)217            call_line = form_value.Unsigned();218          break;219 220        case DW_AT_call_column:221          if (!call_column)222            call_column = form_value.Unsigned();223          break;224 225        case DW_AT_frame_base:226          if (frame_base) {227            if (form_value.BlockData()) {228              uint64_t block_offset =229                  form_value.BlockData() - data.GetDataStart();230              uint64_t block_length = form_value.Unsigned();231              *frame_base =232                  DWARFExpressionList(module,233                                      DWARFExpression(DataExtractor(234                                          data, block_offset, block_length)),235                                      cu);236            } else {237              DataExtractor data = cu->GetLocationData();238              const dw_offset_t offset = form_value.Unsigned();239              if (data.ValidOffset(offset)) {240                data = DataExtractor(data, offset, data.GetByteSize() - offset);241                if (lo_pc != LLDB_INVALID_ADDRESS) {242                  assert(lo_pc >= cu->GetBaseAddress());243                  cu->ParseDWARFLocationList(data, *frame_base);244                  frame_base->SetFuncFileAddress(lo_pc);245                } else246                  set_frame_base_loclist_addr = true;247              }248            }249          }250          break;251 252        default:253          break;254        }255      }256    }257  }258 259  if (ranges.empty() && lo_pc != LLDB_INVALID_ADDRESS) {260    lldb::addr_t range_hi_pc =261        (hi_pc != LLDB_INVALID_ADDRESS && hi_pc > lo_pc) ? hi_pc : lo_pc;262    ranges.emplace_back(lo_pc, range_hi_pc);263  }264 265  if (set_frame_base_loclist_addr && !ranges.empty()) {266    dw_addr_t file_addr = ranges.begin()->LowPC;267    assert(file_addr >= cu->GetBaseAddress());268    frame_base->SetFuncFileAddress(file_addr);269  }270 271  if (ranges.empty() || name == nullptr || mangled == nullptr) {272    for (const DWARFDIE &die : dies) {273      if (die) {274        die.GetDIE()->GetDIENamesAndRanges(die.GetCU(), name, mangled, ranges,275                                           decl_file, decl_line, decl_column,276                                           call_file, call_line, call_column);277      }278    }279  }280  return !ranges.empty();281}282 283/// Helper for the public \ref DWARFDebugInfoEntry::GetAttributes API.284/// Adds all attributes of the DIE at the top of the \c worklist to the285/// \c attributes list. Specifcations and abstract origins are added286/// to the \c worklist if the referenced DIE has not been seen before.287static bool288GetAttributes(llvm::SmallVectorImpl<DWARFDIE> &worklist,289              llvm::SmallPtrSet<DWARFDebugInfoEntry const *, 3> &seen,290              DWARFAttributes &attributes) {291  assert(!worklist.empty() && "Need at least one DIE to visit.");292  assert(seen.size() >= 1 &&293         "Need to have seen at least the currently visited entry.");294 295  DWARFDIE current = worklist.pop_back_val();296 297  const auto *cu = current.GetCU();298  assert(cu);299 300  const auto *entry = current.GetDIE();301  assert(entry);302 303  const auto *abbrevDecl =304      entry->GetAbbreviationDeclarationPtr(current.GetCU());305  if (!abbrevDecl)306    return false;307 308  const DWARFDataExtractor &data = cu->GetData();309  lldb::offset_t offset = current.GetDIE()->GetFirstAttributeOffset();310 311  const bool is_first_die = seen.size() == 1;312 313  for (const auto &attribute : abbrevDecl->attributes()) {314    DWARFFormValue form_value(cu);315    dw_attr_t attr;316    ExtractAttrAndFormValue(attribute, attr, form_value);317 318    // If we are tracking down DW_AT_specification or DW_AT_abstract_origin319    // attributes, the depth will be non-zero. We need to omit certain320    // attributes that don't make sense.321    switch (attr) {322    case DW_AT_sibling:323    case DW_AT_declaration:324      if (!is_first_die) {325        // This attribute doesn't make sense when combined with the DIE that326        // references this DIE. We know a DIE is referencing this DIE because327        // we've visited more than one DIE already.328        break;329      }330      [[fallthrough]];331    default:332      attributes.Append(form_value, offset, attr);333      break;334    }335 336    if (attr == DW_AT_specification || attr == DW_AT_abstract_origin) {337      if (form_value.ExtractValue(data, &offset)) {338        if (DWARFDIE spec_die = form_value.Reference()) {339          if (seen.insert(spec_die.GetDIE()).second)340            worklist.push_back(spec_die);341        }342      }343    } else {344      const dw_form_t form = form_value.Form();345      std::optional<uint8_t> fixed_skip_size =346          DWARFFormValue::GetFixedSize(form, cu);347      if (fixed_skip_size)348        offset += *fixed_skip_size;349      else350        DWARFFormValue::SkipValue(form, data, &offset, cu);351    }352  }353 354  return true;355}356 357DWARFAttributes DWARFDebugInfoEntry::GetAttributes(const DWARFUnit *cu,358                                                   Recurse recurse) const {359  // FIXME: use ElaboratingDIEIterator to follow specifications/abstract origins360  // instead of maintaining our own worklist/seen list.361 362  DWARFAttributes attributes;363 364  llvm::SmallVector<DWARFDIE, 3> worklist;365  worklist.emplace_back(cu, this);366 367  // Keep track if DIEs already seen to prevent infinite recursion.368  // Value of '3' was picked for the same reason that369  // DWARFDie::findRecursively does.370  llvm::SmallPtrSet<DWARFDebugInfoEntry const *, 3> seen;371  seen.insert(this);372 373  do {374    if (!::GetAttributes(worklist, seen, attributes)) {375      attributes.Clear();376      break;377    }378  } while (!worklist.empty() && recurse == Recurse::yes);379 380  return attributes;381}382 383// GetAttributeValue384//385// Get the value of an attribute and return the .debug_info or .debug_types386// offset of the attribute if it was properly extracted into form_value,387// or zero if we fail since an offset of zero is invalid for an attribute (it388// would be a compile unit header).389dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(390    const DWARFUnit *cu, const dw_attr_t attr, DWARFFormValue &form_value,391    dw_offset_t *end_attr_offset_ptr, bool check_elaborating_dies) const {392  if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {393    std::optional<uint32_t> attr_idx = abbrevDecl->findAttributeIndex(attr);394 395    if (attr_idx) {396      const DWARFDataExtractor &data = cu->GetData();397      lldb::offset_t offset = GetFirstAttributeOffset();398 399      uint32_t idx = 0;400      while (idx < *attr_idx)401        DWARFFormValue::SkipValue(abbrevDecl->getFormByIndex(idx++), data,402                                  &offset, cu);403 404      const dw_offset_t attr_offset = offset;405      form_value.SetUnit(cu);406      form_value.SetForm(abbrevDecl->getFormByIndex(idx));407      if (abbrevDecl->getAttrIsImplicitConstByIndex(idx))408        form_value.SetValue(abbrevDecl->getAttrImplicitConstValueByIndex(idx));409 410      if (form_value.ExtractValue(data, &offset)) {411        if (end_attr_offset_ptr)412          *end_attr_offset_ptr = offset;413        return attr_offset;414      }415    }416  }417 418  if (check_elaborating_dies) {419    for (dw_attr_t elaborating_attr :420         {DW_AT_specification, DW_AT_abstract_origin, DW_AT_signature}) {421      if (!GetAttributeValue(cu, elaborating_attr, form_value))422        continue;423      DWARFDIE die = form_value.Reference();424      if (!die)425        continue;426      dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(427          die.GetCU(), attr, form_value, end_attr_offset_ptr, false);428      if (die_offset)429        return die_offset;430    }431  }432  return 0;433}434 435// GetAttributeValueAsString436//437// Get the value of an attribute as a string return it. The resulting pointer438// to the string data exists within the supplied SymbolFileDWARF and will only439// be available as long as the SymbolFileDWARF is still around and it's content440// doesn't change.441const char *DWARFDebugInfoEntry::GetAttributeValueAsString(442    const DWARFUnit *cu, const dw_attr_t attr, const char *fail_value,443    bool check_elaborating_dies) const {444  DWARFFormValue form_value;445  if (GetAttributeValue(cu, attr, form_value, nullptr, check_elaborating_dies))446    return form_value.AsCString();447  return fail_value;448}449 450// GetAttributeValueAsUnsigned451//452// Get the value of an attribute as unsigned and return it.453uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(454    const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,455    bool check_elaborating_dies) const {456  DWARFFormValue form_value;457  if (GetAttributeValue(cu, attr, form_value, nullptr, check_elaborating_dies))458    return form_value.Unsigned();459  return fail_value;460}461 462std::optional<uint64_t>463DWARFDebugInfoEntry::GetAttributeValueAsOptionalUnsigned(464    const DWARFUnit *cu, const dw_attr_t attr,465    bool check_elaborating_dies) const {466  DWARFFormValue form_value;467  if (GetAttributeValue(cu, attr, form_value, nullptr, check_elaborating_dies))468    return form_value.Unsigned();469  return std::nullopt;470}471 472// GetAttributeValueAsReference473//474// Get the value of an attribute as reference and fix up and compile unit475// relative offsets as needed.476DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(477    const DWARFUnit *cu, const dw_attr_t attr,478    bool check_elaborating_dies) const {479  DWARFFormValue form_value;480  if (GetAttributeValue(cu, attr, form_value, nullptr, check_elaborating_dies))481    return form_value.Reference();482  return {};483}484 485uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(486    const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,487    bool check_elaborating_dies) const {488  DWARFFormValue form_value;489  if (GetAttributeValue(cu, attr, form_value, nullptr, check_elaborating_dies))490    return form_value.Address();491  return fail_value;492}493 494// GetAttributeHighPC495//496// Get the hi_pc, adding hi_pc to lo_pc when specified as an <offset-from-low-497// pc>.498//499// Returns the hi_pc or fail_value.500dw_addr_t501DWARFDebugInfoEntry::GetAttributeHighPC(const DWARFUnit *cu, dw_addr_t lo_pc,502                                        uint64_t fail_value,503                                        bool check_elaborating_dies) const {504  DWARFFormValue form_value;505  if (GetAttributeValue(cu, DW_AT_high_pc, form_value, nullptr,506                        check_elaborating_dies)) {507    dw_form_t form = form_value.Form();508    if (form == DW_FORM_addr || form == DW_FORM_addrx ||509        form == DW_FORM_GNU_addr_index)510      return form_value.Address();511 512    // DWARF4 can specify the hi_pc as an <offset-from-lowpc>513    return lo_pc + form_value.Unsigned();514  }515  return fail_value;516}517 518// GetAttributeAddressRange519//520// Get the lo_pc and hi_pc, adding hi_pc to lo_pc when specified as an <offset-521// from-low-pc>.522//523// Returns true or sets lo_pc and hi_pc to fail_value.524bool DWARFDebugInfoEntry::GetAttributeAddressRange(525    const DWARFUnit *cu, dw_addr_t &lo_pc, dw_addr_t &hi_pc,526    uint64_t fail_value, bool check_elaborating_dies) const {527  lo_pc = GetAttributeValueAsAddress(cu, DW_AT_low_pc, fail_value,528                                     check_elaborating_dies);529  if (lo_pc != fail_value) {530    hi_pc = GetAttributeHighPC(cu, lo_pc, fail_value, check_elaborating_dies);531    if (hi_pc != fail_value)532      return true;533  }534  lo_pc = fail_value;535  hi_pc = fail_value;536  return false;537}538 539llvm::Expected<llvm::DWARFAddressRangesVector>540DWARFDebugInfoEntry::GetAttributeAddressRanges(541    DWARFUnit *cu, bool check_hi_lo_pc, bool check_elaborating_dies) const {542 543  DWARFFormValue form_value;544  if (GetAttributeValue(cu, DW_AT_ranges, form_value))545    return GetRanges(*cu, form_value);546 547  if (check_hi_lo_pc) {548    dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;549    dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;550    if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS,551                                 check_elaborating_dies) &&552        lo_pc < hi_pc)553      return llvm::DWARFAddressRangesVector{{lo_pc, hi_pc}};554  }555  return llvm::createStringError("DIE has no address range information");556}557 558// GetName559//560// Get value of the DW_AT_name attribute and return it if one exists, else561// return NULL.562const char *DWARFDebugInfoEntry::GetName(const DWARFUnit *cu) const {563  return GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);564}565 566// GetMangledName567//568// Get value of the DW_AT_MIPS_linkage_name attribute and return it if one569// exists, else return the value of the DW_AT_name attribute570const char *571DWARFDebugInfoEntry::GetMangledName(const DWARFUnit *cu,572                                    bool substitute_name_allowed) const {573  const char *name = nullptr;574 575  name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);576  if (name)577    return name;578 579  name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);580  if (name)581    return name;582 583  if (!substitute_name_allowed)584    return nullptr;585 586  name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);587  return name;588}589 590// GetPubname591//592// Get value the name for a DIE as it should appear for a .debug_pubnames or593// .debug_pubtypes section.594const char *DWARFDebugInfoEntry::GetPubname(const DWARFUnit *cu) const {595  const char *name = nullptr;596  if (!cu)597    return name;598 599  name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);600  if (name)601    return name;602 603  name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);604  if (name)605    return name;606 607  name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);608  return name;609}610 611/// This function is builds a table very similar to the standard .debug_aranges612/// table, except that the actual DIE offset for the function is placed in the613/// table instead of the compile unit offset.614void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(615    DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {616  Log *log = GetLog(DWARFLog::DebugInfo);617  if (m_tag) {618    // Subprogram forward declarations don't have619    // DW_AT_ranges/DW_AT_low_pc/DW_AT_high_pc attributes, so don't even try620    // getting address range information for them.621    if (m_tag == DW_TAG_subprogram &&622        !GetAttributeValueAsOptionalUnsigned(cu, DW_AT_declaration)) {623      if (llvm::Expected<llvm::DWARFAddressRangesVector> ranges =624              GetAttributeAddressRanges(cu, /*check_hi_lo_pc=*/true)) {625        for (const auto &r : *ranges)626          debug_aranges->AppendRange(GetOffset(), r.LowPC, r.HighPC);627      } else {628        LLDB_LOG_ERROR(log, ranges.takeError(), "DIE({1:x}): {0}", GetOffset());629      }630    }631 632    const DWARFDebugInfoEntry *child = GetFirstChild();633    while (child) {634      child->BuildFunctionAddressRangeTable(cu, debug_aranges);635      child = child->GetSibling();636    }637  }638}639 640lldb::offset_t DWARFDebugInfoEntry::GetFirstAttributeOffset() const {641  return GetOffset() + llvm::getULEB128Size(m_abbr_idx);642}643 644const llvm::DWARFAbbreviationDeclaration *645DWARFDebugInfoEntry::GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const {646  if (!cu)647    return nullptr;648 649  const llvm::DWARFAbbreviationDeclarationSet *abbrev_set =650      cu->GetAbbreviations();651  if (!abbrev_set)652    return nullptr;653 654  return abbrev_set->getAbbreviationDeclaration(m_abbr_idx);655}656 657bool DWARFDebugInfoEntry::IsGlobalOrStaticScopeVariable() const {658  if (Tag() != DW_TAG_variable && Tag() != DW_TAG_member)659    return false;660  const DWARFDebugInfoEntry *parent_die = GetParent();661  while (parent_die != nullptr) {662    switch (parent_die->Tag()) {663    case DW_TAG_subprogram:664    case DW_TAG_lexical_block:665    case DW_TAG_inlined_subroutine:666      return false;667 668    case DW_TAG_compile_unit:669    case DW_TAG_partial_unit:670      return true;671 672    default:673      break;674    }675    parent_die = parent_die->GetParent();676  }677  return false;678}679 680bool DWARFDebugInfoEntry::operator==(const DWARFDebugInfoEntry &rhs) const {681  return m_offset == rhs.m_offset && m_parent_idx == rhs.m_parent_idx &&682         m_sibling_idx == rhs.m_sibling_idx &&683         m_abbr_idx == rhs.m_abbr_idx && m_has_children == rhs.m_has_children &&684         m_tag == rhs.m_tag;685}686 687bool DWARFDebugInfoEntry::operator!=(const DWARFDebugInfoEntry &rhs) const {688  return !(*this == rhs);689}690