C++ DWARFFormValue类代码示例

void ObjectLoadListener::extractLocalLocations(
    const DWARFUnit *CU, const DWARFDebugInfoEntryMinimal *DebugEntry,
    std::vector<uint64_t> &Offsets) {
  if (DebugEntry->isNULL())
    return;
  if (DebugEntry->getTag() == dwarf::DW_TAG_formal_parameter ||
      DebugEntry->getTag() == dwarf::DW_TAG_variable) {
    uint64_t Offset;

    // Extract offset for each local found
    DWARFFormValue FormValue;
    if (DebugEntry->getAttributeValue(CU, dwarf::DW_AT_location, FormValue)) {
      Optional<ArrayRef<uint8_t>> FormValues = FormValue.getAsBlock();
      Offset = FormValues->back();
    }

    Offsets.push_back(Offset);
  }

  const DWARFDebugInfoEntryMinimal *Child = DebugEntry->getFirstChild();

  // Extract info for DebugEntry's child and its child's siblings.
  while (Child) {
    extractLocalLocations(CU, Child, Offsets);
    Child = Child->getSibling();
  }
}

void DWARFTypeUnit::dump(raw_ostream &OS, bool SummarizeTypes) {
  const DWARFDebugInfoEntryMinimal *TD =
      getDIEForOffset(TypeOffset + getOffset());
  DWARFFormValue NameVal;
  const char *Name = "";
  if (TD->getAttributeValue(this, llvm::dwarf::DW_AT_name, NameVal))
    if (auto ON = NameVal.getAsCString(this))
      Name = *ON;

  if (SummarizeTypes) {
    OS << "name = '" << Name << "'"
       << " type_signature = " << format("0x%16" PRIx64, TypeHash)
       << " length = " << format("0x%08x", getLength()) << '\n';
    return;
  }

  OS << format("0x%08x", getOffset()) << ": Type Unit:"
     << " length = " << format("0x%08x", getLength())
     << " version = " << format("0x%04x", getVersion())
     << " abbr_offset = " << format("0x%04x", getAbbreviations()->getOffset())
     << " addr_size = " << format("0x%02x", getAddressByteSize())
     << " name = '" << Name << "'"
     << " type_signature = " << format("0x%16" PRIx64, TypeHash)
     << " type_offset = " << format("0x%04x", TypeOffset)
     << " (next unit at " << format("0x%08x", getNextUnitOffset()) << ")\n";

  if (const DWARFDebugInfoEntryMinimal *TU = getUnitDIE(false))
    TU->dump(OS, this, -1U);
  else
    OS << "<type unit can't be parsed!>\n\n";
}

uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsSectionOffset(
    const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const {
  DWARFFormValue FormValue;
  if (!getAttributeValue(U, Attr, FormValue))
    return FailValue;
  Optional<uint64_t> Result = FormValue.getAsSectionOffset();
  return Result.hasValue() ? Result.getValue() : FailValue;
}

const char *DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
    const DWARFUnit *U, const uint16_t Attr, const char *FailValue) const {
  DWARFFormValue FormValue;
  if (!getAttributeValue(U, Attr, FormValue))
    return FailValue;
  Optional<const char *> Result = FormValue.getAsCString(U);
  return Result.hasValue() ? Result.getValue() : FailValue;
}

DIERef::DIERef(const DWARFFormValue &form_value)
    : cu_offset(DW_INVALID_OFFSET), die_offset(DW_INVALID_OFFSET) {
  if (form_value.IsValid()) {
    const DWARFUnit *dwarf_cu = form_value.GetCompileUnit();
    if (dwarf_cu) {
      if (dwarf_cu->GetBaseObjOffset() != DW_INVALID_OFFSET)
        cu_offset = dwarf_cu->GetBaseObjOffset();
      else
        cu_offset = dwarf_cu->GetOffset();
    }
    die_offset = form_value.Reference();
  }
}

uint32_t
DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
                                              const uint16_t attr,
                                              DWARFFormValue &form_value,
                                              uint32_t *end_attr_offset_ptr)
                                              const {
  if (AbbrevDecl) {
    uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);

    if (attr_idx != -1U) {
      uint32_t offset = getOffset();

      DataExtractor debug_info_data = cu->getDebugInfoExtractor();

      // Skip the abbreviation code so we are at the data for the attributes
      debug_info_data.getULEB128(&offset);

      uint32_t idx = 0;
      while (idx < attr_idx)
        DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
                                  debug_info_data, &offset, cu);

      const uint32_t attr_offset = offset;
      form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
      if (form_value.extractValue(debug_info_data, &offset, cu)) {
        if (end_attr_offset_ptr)
          *end_attr_offset_ptr = offset;
        return attr_offset;
      }
    }
  }

  return 0;
}

static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
                         DWARFUnit *U, unsigned Indent,
                         DIDumpOptions DumpOpts) {
  DWARFContext &Ctx = U->getContext();
  const DWARFObject &Obj = Ctx.getDWARFObj();
  const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
  if (FormValue.isFormClass(DWARFFormValue::FC_Block) ||
      FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) {
    ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
    DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
                       Ctx.isLittleEndian(), 0);
    DWARFExpression(Data, U->getVersion(), U->getAddressByteSize())
        .print(OS, MRI);
    return;
  }

  FormValue.dump(OS, DumpOpts);
  if (FormValue.isFormClass(DWARFFormValue::FC_SectionOffset)) {
    const DWARFSection &LocSection = Obj.getLocSection();
    const DWARFSection &LocDWOSection = Obj.getLocDWOSection();
    uint32_t Offset = *FormValue.getAsSectionOffset();
    if (!LocSection.Data.empty()) {
      DWARFDebugLoc DebugLoc;
      DWARFDataExtractor Data(Obj, LocSection, Ctx.isLittleEndian(),
                              Obj.getAddressSize());
      auto LL = DebugLoc.parseOneLocationList(Data, &Offset);
      if (LL) {
        uint64_t BaseAddr = 0;
        if (Optional<BaseAddress> BA = U->getBaseAddress())
          BaseAddr = BA->Address;
        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, BaseAddr,
                 Indent);
      } else
        OS << "error extracting location list.";
    } else if (!LocDWOSection.Data.empty()) {
      DataExtractor Data(LocDWOSection.Data, Ctx.isLittleEndian(), 0);
      auto LL = DWARFDebugLocDWO::parseOneLocationList(Data, &Offset);
      if (LL)
        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, Indent);
      else
        OS << "error extracting location list.";
    }
  }
}

bool DWARFDebugInfoEntryMinimal::getAttributeValue(
    const DWARFUnit *U, const uint16_t Attr, DWARFFormValue &FormValue) const {
  if (!AbbrevDecl)
    return false;

  uint32_t AttrIdx = AbbrevDecl->findAttributeIndex(Attr);
  if (AttrIdx == -1U)
    return false;

  DataExtractor DebugInfoData = U->getDebugInfoExtractor();
  uint32_t DebugInfoOffset = getOffset();

  // Skip the abbreviation code so we are at the data for the attributes
  DebugInfoData.getULEB128(&DebugInfoOffset);

  // Skip preceding attribute values.
  for (uint32_t i = 0; i < AttrIdx; ++i) {
    DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(i),
                              DebugInfoData, &DebugInfoOffset, U);
  }

  FormValue = DWARFFormValue(AbbrevDecl->getFormByIndex(AttrIdx));
  return FormValue.extractValue(DebugInfoData, &DebugInfoOffset, U);
}

void ObjectLoadListener::getDebugInfoForLocals(
    DWARFContextInMemory &DwarfContext, uint64_t Addr, uint64_t Size) {
  for (const auto &CU : DwarfContext.compile_units()) {
    const DWARFDebugInfoEntryMinimal *UnitDIE = CU->getUnitDIE(false);
    const DWARFDebugInfoEntryMinimal *SubprogramDIE = getSubprogramDIE(UnitDIE);

    ICorDebugInfo::RegNum FrameBaseRegister = ICorDebugInfo::REGNUM_COUNT;
    DWARFFormValue FormValue;

    // Find the frame_base register value
    if (SubprogramDIE->getAttributeValue(CU.get(), dwarf::DW_AT_frame_base,
                                         FormValue)) {
      Optional<ArrayRef<uint8_t>> FormValues = FormValue.getAsBlock();
      FrameBaseRegister = mapDwarfRegisterToRegNum(FormValues->back());
    }

    if (SubprogramDIE->getAttributeValue(CU.get(), dwarf::DW_AT_low_pc,
                                         FormValue)) {
      Optional<uint64_t> FormAddress = FormValue.getAsAddress(CU.get());

      // If the Form address doesn't match the address for the function passed
      // do not collect debug for locals since they do not go with the current
      // function being processed
      if (FormAddress.getValue() != Addr) {
        return;
      }
    }

    std::vector<uint64_t> Offsets;
    extractLocalLocations(CU.get(), SubprogramDIE, Offsets);

    // Allocate the array of NativeVarInfo objects that will be sent to the EE
    ICorDebugInfo::NativeVarInfo *LocalVars;
    unsigned SizeOfArray =
        Offsets.size() * sizeof(ICorDebugInfo::NativeVarInfo);
    if (SizeOfArray > 0) {
      LocalVars =
          (ICorDebugInfo::NativeVarInfo *)Context->JitInfo->allocateArray(
              SizeOfArray);

      unsigned CurrentDebugEntry = 0;

      for (auto &Offset : Offsets) {
        LocalVars[CurrentDebugEntry].startOffset = Addr;
        LocalVars[CurrentDebugEntry].endOffset = Addr + Size;
        LocalVars[CurrentDebugEntry].varNumber = CurrentDebugEntry;

        // Assume all locals are on the stack
        ICorDebugInfo::VarLoc VarLoc;
        VarLoc.vlType = ICorDebugInfo::VLT_STK;
        VarLoc.vlStk.vlsBaseReg = FrameBaseRegister;
        VarLoc.vlStk.vlsOffset = Offset;

        LocalVars[CurrentDebugEntry].loc = VarLoc;

        CurrentDebugEntry++;
      }

      CORINFO_METHOD_INFO *MethodInfo = Context->MethodInfo;
      CORINFO_METHOD_HANDLE MethodHandle = MethodInfo->ftn;

      Context->JitInfo->setVars(MethodHandle, Offsets.size(), LocalVars);
    }
  }
}

static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
                         DWARFUnit *U, unsigned Indent,
                         DIDumpOptions DumpOpts) {
  DWARFContext &Ctx = U->getContext();
  const DWARFObject &Obj = Ctx.getDWARFObj();
  const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
  if (FormValue.isFormClass(DWARFFormValue::FC_Block) ||
      FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) {
    ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
    DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
                       Ctx.isLittleEndian(), 0);
    DWARFExpression(Data, U->getVersion(), U->getAddressByteSize())
        .print(OS, MRI, U);
    return;
  }

  FormValue.dump(OS, DumpOpts);
  if (FormValue.isFormClass(DWARFFormValue::FC_SectionOffset)) {
    uint32_t Offset = *FormValue.getAsSectionOffset();
    if (!U->isDWOUnit() && !U->getLocSection()->Data.empty()) {
      DWARFDebugLoc DebugLoc;
      DWARFDataExtractor Data(Obj, *U->getLocSection(), Ctx.isLittleEndian(),
                              Obj.getAddressSize());
      auto LL = DebugLoc.parseOneLocationList(Data, &Offset);
      if (LL) {
        uint64_t BaseAddr = 0;
        if (Optional<object::SectionedAddress> BA = U->getBaseAddress())
          BaseAddr = BA->Address;
        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, U,
                 BaseAddr, Indent);
      } else
        OS << "error extracting location list.";
      return;
    }

    bool UseLocLists = !U->isDWOUnit();
    StringRef LoclistsSectionData =
        UseLocLists ? Obj.getLoclistsSection().Data : U->getLocSectionData();

    if (!LoclistsSectionData.empty()) {
      DataExtractor Data(LoclistsSectionData, Ctx.isLittleEndian(),
                         Obj.getAddressSize());

      // Old-style location list were used in DWARF v4 (.debug_loc.dwo section).
      // Modern locations list (.debug_loclists) are used starting from v5.
      // Ideally we should take the version from the .debug_loclists section
      // header, but using CU's version for simplicity.
      auto LL = DWARFDebugLoclists::parseOneLocationList(
          Data, &Offset, UseLocLists ? U->getVersion() : 4);

      uint64_t BaseAddr = 0;
      if (Optional<object::SectionedAddress> BA = U->getBaseAddress())
        BaseAddr = BA->Address;

      if (LL)
        LL->dump(OS, BaseAddr, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI,
                 U, Indent);
      else
        OS << "error extracting location list.";
    }
  }
}

static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
                          uint32_t *OffsetPtr, dwarf::Attribute Attr,
                          dwarf::Form Form, unsigned Indent,
                          DIDumpOptions DumpOpts) {
  if (!Die.isValid())
    return;
  const char BaseIndent[] = "            ";
  OS << BaseIndent;
  OS.indent(Indent + 2);
  WithColor(OS, HighlightColor::Attribute) << formatv("{0}", Attr);

  if (DumpOpts.Verbose || DumpOpts.ShowForm)
    OS << formatv(" [{0}]", Form);

  DWARFUnit *U = Die.getDwarfUnit();
  DWARFFormValue FormValue = DWARFFormValue::createFromUnit(Form, U, OffsetPtr);

  OS << "\t(";

  StringRef Name;
  std::string File;
  auto Color = HighlightColor::Enumerator;
  if (Attr == DW_AT_decl_file || Attr == DW_AT_call_file) {
    Color = HighlightColor::String;
    if (const auto *LT = U->getContext().getLineTableForUnit(U))
      if (LT->getFileNameByIndex(
              FormValue.getAsUnsignedConstant().getValue(),
              U->getCompilationDir(),
              DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, File)) {
        File = '"' + File + '"';
        Name = File;
      }
  } else if (Optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
    Name = AttributeValueString(Attr, *Val);

  if (!Name.empty())
    WithColor(OS, Color) << Name;
  else if (Attr == DW_AT_decl_line || Attr == DW_AT_call_line)
    OS << *FormValue.getAsUnsignedConstant();
  else if (Attr == DW_AT_high_pc && !DumpOpts.ShowForm && !DumpOpts.Verbose &&
           FormValue.getAsUnsignedConstant()) {
    if (DumpOpts.ShowAddresses) {
      // Print the actual address rather than the offset.
      uint64_t LowPC, HighPC, Index;
      if (Die.getLowAndHighPC(LowPC, HighPC, Index))
        OS << format("0x%016" PRIx64, HighPC);
      else
        FormValue.dump(OS, DumpOpts);
    }
  } else if (DWARFAttribute::mayHaveLocationDescription(Attr))
    dumpLocation(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4, DumpOpts);
  else
    FormValue.dump(OS, DumpOpts);

  std::string Space = DumpOpts.ShowAddresses ? " " : "";

  // We have dumped the attribute raw value. For some attributes
  // having both the raw value and the pretty-printed value is
  // interesting. These attributes are handled below.
  if (Attr == DW_AT_specification || Attr == DW_AT_abstract_origin) {
    if (const char *Name =
            Die.getAttributeValueAsReferencedDie(FormValue).getName(
                DINameKind::LinkageName))
      OS << Space << "\"" << Name << '\"';
  } else if (Attr == DW_AT_type) {
    OS << Space << "\"";
    dumpTypeName(OS, Die.getAttributeValueAsReferencedDie(FormValue));
    OS << '"';
  } else if (Attr == DW_AT_APPLE_property_attribute) {
    if (Optional<uint64_t> OptVal = FormValue.getAsUnsignedConstant())
      dumpApplePropertyAttribute(OS, *OptVal);
  } else if (Attr == DW_AT_ranges) {
    const DWARFObject &Obj = Die.getDwarfUnit()->getContext().getDWARFObj();
    // For DW_FORM_rnglistx we need to dump the offset separately, since
    // we have only dumped the index so far.
    if (FormValue.getForm() == DW_FORM_rnglistx)
      if (auto RangeListOffset =
              U->getRnglistOffset(*FormValue.getAsSectionOffset())) {
        DWARFFormValue FV = DWARFFormValue::createFromUValue(
            dwarf::DW_FORM_sec_offset, *RangeListOffset);
        FV.dump(OS, DumpOpts);
      }
    if (auto RangesOrError = Die.getAddressRanges())
      dumpRanges(Obj, OS, RangesOrError.get(), U->getAddressByteSize(),
                 sizeof(BaseIndent) + Indent + 4, DumpOpts);
    else
      WithColor::error() << "decoding address ranges: "
                         << toString(RangesOrError.takeError()) << '\n';
  }

  OS << ")\n";
}

int
DWARFFormValue::Compare (const DWARFFormValue& a_value, const DWARFFormValue& b_value, const DWARFCompileUnit* a_cu, const DWARFCompileUnit* b_cu, const DWARFDataExtractor* debug_str_data_ptr)
{
    dw_form_t a_form = a_value.Form();
    dw_form_t b_form = b_value.Form();
    if (a_form < b_form)
        return -1;
    if (a_form > b_form)
        return 1;
    switch (a_form)
    {
    case DW_FORM_addr:
    case DW_FORM_flag:
    case DW_FORM_data1:
    case DW_FORM_data2:
    case DW_FORM_data4:
    case DW_FORM_data8:
    case DW_FORM_udata:
    case DW_FORM_ref_addr:
    case DW_FORM_sec_offset:
    case DW_FORM_flag_present:
    case DW_FORM_ref_sig8:
        {
            uint64_t a = a_value.Unsigned();
            uint64_t b = b_value.Unsigned();
            if (a < b)
                return -1;
            if (a > b)
                return 1;
            return 0;
        }

    case DW_FORM_sdata:
        {
            int64_t a = a_value.Signed();
            int64_t b = b_value.Signed();
            if (a < b)
                return -1;
            if (a > b)
                return 1;
            return 0;
        }

    case DW_FORM_string:
    case DW_FORM_strp:
        {
            const char *a_string = a_value.AsCString(debug_str_data_ptr);
            const char *b_string = b_value.AsCString(debug_str_data_ptr);
            if (a_string == b_string)
                return 0;
            else if (a_string && b_string)
                return strcmp(a_string, b_string);
            else if (a_string == NULL)
                return -1;  // A string is NULL, and B is valid
            else
                return 1;   // A string valid, and B is NULL
        }


    case DW_FORM_block:
    case DW_FORM_block1:
    case DW_FORM_block2:
    case DW_FORM_block4:
    case DW_FORM_exprloc:
        {
            uint64_t a_len = a_value.Unsigned();
            uint64_t b_len = b_value.Unsigned();
            if (a_len < b_len)
                return -1;
            if (a_len > b_len)
                return 1;
            // The block lengths are the same
            return memcmp(a_value.BlockData(), b_value.BlockData(), a_value.Unsigned());
        }
        break;

    case DW_FORM_ref1:
    case DW_FORM_ref2:
    case DW_FORM_ref4:
    case DW_FORM_ref8:
    case DW_FORM_ref_udata:
        {
            uint64_t a = a_value.Reference(a_cu);
            uint64_t b = b_value.Reference(b_cu);
            if (a < b)
                return -1;
            if (a > b)
                return 1;
            return 0;
        }

    case DW_FORM_indirect:
        assert(!"This shouldn't happen after the form has been extracted...");
        break;

    default:
        assert(!"Unhandled DW_FORM");
        break;
    }
    return -1;
//.........这里部分代码省略.........