C++ DWARFDie::findRecursively方法代码示例

static bool isVariableIndexable(const DWARFDie &Die, DWARFContext &DCtx) {
  Optional<DWARFFormValue> Location = Die.findRecursively(DW_AT_location);
  if (!Location)
    return false;

  auto ContainsInterestingOperators = [&](StringRef D) {
    DWARFUnit *U = Die.getDwarfUnit();
    DataExtractor Data(D, DCtx.isLittleEndian(), U->getAddressByteSize());
    DWARFExpression Expression(Data, U->getVersion(), U->getAddressByteSize());
    return any_of(Expression, [](DWARFExpression::Operation &Op) {
      return !Op.isError() && (Op.getCode() == DW_OP_addr ||
                               Op.getCode() == DW_OP_form_tls_address ||
                               Op.getCode() == DW_OP_GNU_push_tls_address);
    });
  };

  if (Optional<ArrayRef<uint8_t>> Expr = Location->getAsBlock()) {
    // Inlined location.
    if (ContainsInterestingOperators(toStringRef(*Expr)))
      return true;
  } else if (Optional<uint64_t> Offset = Location->getAsSectionOffset()) {
    // Location list.
    if (const DWARFDebugLoc *DebugLoc = DCtx.getDebugLoc()) {
      if (const DWARFDebugLoc::LocationList *LocList =
              DebugLoc->getLocationListAtOffset(*Offset)) {
        if (any_of(LocList->Entries, [&](const DWARFDebugLoc::Entry &E) {
              return ContainsInterestingOperators({E.Loc.data(), E.Loc.size()});
            }))
          return true;
      }
    }
  }
  return false;
}

unsigned DWARFVerifier::verifyNameIndexCompleteness(
    const DWARFDie &Die, const DWARFDebugNames::NameIndex &NI) {

  // First check, if the Die should be indexed. The code follows the DWARF v5
  // wording as closely as possible.

  // "All non-defining declarations (that is, debugging information entries
  // with a DW_AT_declaration attribute) are excluded."
  if (Die.find(DW_AT_declaration))
    return 0;

  // "DW_TAG_namespace debugging information entries without a DW_AT_name
  // attribute are included with the name “(anonymous namespace)”.
  // All other debugging information entries without a DW_AT_name attribute
  // are excluded."
  // "If a subprogram or inlined subroutine is included, and has a
  // DW_AT_linkage_name attribute, there will be an additional index entry for
  // the linkage name."
  auto IncludeLinkageName = Die.getTag() == DW_TAG_subprogram ||
                            Die.getTag() == DW_TAG_inlined_subroutine;
  auto EntryNames = getNames(Die, IncludeLinkageName);
  if (EntryNames.empty())
    return 0;

  // We deviate from the specification here, which says:
  // "The name index must contain an entry for each debugging information entry
  // that defines a named subprogram, label, variable, type, or namespace,
  // subject to ..."
  // Instead whitelisting all TAGs representing a "type" or a "subprogram", to
  // make sure we catch any missing items, we instead blacklist all TAGs that we
  // know shouldn't be indexed.
  switch (Die.getTag()) {
  // Compile units and modules have names but shouldn't be indexed.
  case DW_TAG_compile_unit:
  case DW_TAG_module:
    return 0;

  // Function and template parameters are not globally visible, so we shouldn't
  // index them.
  case DW_TAG_formal_parameter:
  case DW_TAG_template_value_parameter:
  case DW_TAG_template_type_parameter:
  case DW_TAG_GNU_template_parameter_pack:
  case DW_TAG_GNU_template_template_param:
    return 0;

  // Object members aren't globally visible.
  case DW_TAG_member:
    return 0;

  // According to a strict reading of the specification, enumerators should not
  // be indexed (and LLVM currently does not do that). However, this causes
  // problems for the debuggers, so we may need to reconsider this.
  case DW_TAG_enumerator:
    return 0;

  // Imported declarations should not be indexed according to the specification
  // and LLVM currently does not do that.
  case DW_TAG_imported_declaration:
    return 0;

  // "DW_TAG_subprogram, DW_TAG_inlined_subroutine, and DW_TAG_label debugging
  // information entries without an address attribute (DW_AT_low_pc,
  // DW_AT_high_pc, DW_AT_ranges, or DW_AT_entry_pc) are excluded."
  case DW_TAG_subprogram:
  case DW_TAG_inlined_subroutine:
  case DW_TAG_label:
    if (Die.findRecursively(
            {DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_entry_pc}))
      break;
    return 0;

  // "DW_TAG_variable debugging information entries with a DW_AT_location
  // attribute that includes a DW_OP_addr or DW_OP_form_tls_address operator are
  // included; otherwise, they are excluded."
  //
  // LLVM extension: We also add DW_OP_GNU_push_tls_address to this list.
  case DW_TAG_variable:
    if (isVariableIndexable(Die, DCtx))
      break;
    return 0;

  default:
    break;
  }

  // Now we know that our Die should be present in the Index. Let's check if
  // that's the case.
  unsigned NumErrors = 0;
  uint64_t DieUnitOffset = Die.getOffset() - Die.getDwarfUnit()->getOffset();
  for (StringRef Name : EntryNames) {
    if (none_of(NI.equal_range(Name), [&](const DWARFDebugNames::Entry &E) {
          return E.getDIEUnitOffset() == DieUnitOffset;
        })) {
      error() << formatv("Name Index @ {0:x}: Entry for DIE @ {1:x} ({2}) with "
                         "name {3} missing.\n",
                         NI.getUnitOffset(), Die.getOffset(), Die.getTag(),
                         Name);
      ++NumErrors;
    }
//.........这里部分代码省略.........