text: //===- DWARFDebugInfoEntry.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/DWARFDebugInfoEntry.h"
  #include "llvm/ADT/Optional.h"
  #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
  #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
  #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
  #include "llvm/Support/DataExtractor.h"
  #include <cstddef>
  #include <cstdint>
  
  using namespace llvm;
  using namespace dwarf;
  
  bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U,
                                               uint32_t *OffsetPtr) {
    DWARFDataExtractor DebugInfoData = U.getDebugInfoExtractor();
    const uint32_t UEndOffset = U.getNextUnitOffset();
    return extractFast(U, OffsetPtr, DebugInfoData, UEndOffset, 0);
  }
  
  bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint32_t *OffsetPtr,
                                        const DWARFDataExtractor &DebugInfoData,
                                        uint32_t UEndOffset, uint32_t D) {
    Offset = *OffsetPtr;
    Depth = D;
    if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset))
      return false;
    uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
    if (0 == AbbrCode) {
      // NULL debug tag entry.
      AbbrevDecl = nullptr;
      return true;
    }
    AbbrevDecl = U.getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
    if (nullptr == AbbrevDecl) {
      // Restore the original offset.
      *OffsetPtr = Offset;
      return false;
    }
    // See if all attributes in this DIE have fixed byte sizes. If so, we can
    // just add this size to the offset to skip to the next DIE.
    if (Optional<size_t> FixedSize = AbbrevDecl->getFixedAttributesByteSize(U)) {
      *OffsetPtr += *FixedSize;
      return true;
    }
  
    // Skip all data in the .debug_info for the attributes
    for (const auto &AttrSpec : AbbrevDecl->attributes()) {
      // Check if this attribute has a fixed byte size.
      if (auto FixedSize = AttrSpec.getByteSize(U)) {
        // Attribute byte size if fixed, just add the size to the offset.
        *OffsetPtr += *FixedSize;
      } else if (!DWARFFormValue::skipValue(AttrSpec.Form, DebugInfoData,
                                            OffsetPtr, U.getFormParams())) {
        // We failed to skip this attribute's value, restore the original offset
        // and return the failure status.
        *OffsetPtr = Offset;
        return false;
      }
    }
    return true;
  }
  