Move coverage related code into a separate library.

Differential Revision: http://reviews.llvm.org/D19333

llvm-svn: 268089

1 files changed, 619 insertions, 0 deletions

diff --git a/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp b/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp
new file mode 100644
index 00000000000..78f7186eac8
--- /dev/null
+++ b/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp
@@ -0,0 +1,619 @@
+//=-- CoverageMappingReader.cpp - Code coverage mapping reader ----*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for reading coverage mapping data for
+// instrumentation based coverage.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ProfileData/Coverage/CoverageMappingReader.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/Object/MachOUniversal.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/LEB128.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+using namespace coverage;
+using namespace object;
+
+#define DEBUG_TYPE "coverage-mapping"
+
+void CoverageMappingIterator::increment() {
+  // Check if all the records were read or if an error occurred while reading
+  // the next record.
+  if (Reader->readNextRecord(Record))
+    *this = CoverageMappingIterator();
+}
+
+std::error_code RawCoverageReader::readULEB128(uint64_t &Result) {
+  if (Data.size() < 1)
+    return coveragemap_error::truncated;
+  unsigned N = 0;
+  Result = decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N);
+  if (N > Data.size())
+    return coveragemap_error::malformed;
+  Data = Data.substr(N);
+  return std::error_code();
+}
+
+std::error_code RawCoverageReader::readIntMax(uint64_t &Result,
+                                              uint64_t MaxPlus1) {
+  if (auto Err = readULEB128(Result))
+    return Err;
+  if (Result >= MaxPlus1)
+    return coveragemap_error::malformed;
+  return std::error_code();
+}
+
+std::error_code RawCoverageReader::readSize(uint64_t &Result) {
+  if (auto Err = readULEB128(Result))
+    return Err;
+  // Sanity check the number.
+  if (Result > Data.size())
+    return coveragemap_error::malformed;
+  return std::error_code();
+}
+
+std::error_code RawCoverageReader::readString(StringRef &Result) {
+  uint64_t Length;
+  if (auto Err = readSize(Length))
+    return Err;
+  Result = Data.substr(0, Length);
+  Data = Data.substr(Length);
+  return std::error_code();
+}
+
+std::error_code RawCoverageFilenamesReader::read() {
+  uint64_t NumFilenames;
+  if (auto Err = readSize(NumFilenames))
+    return Err;
+  for (size_t I = 0; I < NumFilenames; ++I) {
+    StringRef Filename;
+    if (auto Err = readString(Filename))
+      return Err;
+    Filenames.push_back(Filename);
+  }
+  return std::error_code();
+}
+
+std::error_code RawCoverageMappingReader::decodeCounter(unsigned Value,
+                                                        Counter &C) {
+  auto Tag = Value & Counter::EncodingTagMask;
+  switch (Tag) {
+  case Counter::Zero:
+    C = Counter::getZero();
+    return std::error_code();
+  case Counter::CounterValueReference:
+    C = Counter::getCounter(Value >> Counter::EncodingTagBits);
+    return std::error_code();
+  default:
+    break;
+  }
+  Tag -= Counter::Expression;
+  switch (Tag) {
+  case CounterExpression::Subtract:
+  case CounterExpression::Add: {
+    auto ID = Value >> Counter::EncodingTagBits;
+    if (ID >= Expressions.size())
+      return coveragemap_error::malformed;
+    Expressions[ID].Kind = CounterExpression::ExprKind(Tag);
+    C = Counter::getExpression(ID);
+    break;
+  }
+  default:
+    return coveragemap_error::malformed;
+  }
+  return std::error_code();
+}
+
+std::error_code RawCoverageMappingReader::readCounter(Counter &C) {
+  uint64_t EncodedCounter;
+  if (auto Err =
+          readIntMax(EncodedCounter, std::numeric_limits<unsigned>::max()))
+    return Err;
+  if (auto Err = decodeCounter(EncodedCounter, C))
+    return Err;
+  return std::error_code();
+}
+
+static const unsigned EncodingExpansionRegionBit = 1
+                                                   << Counter::EncodingTagBits;
+
+/// \brief Read the sub-array of regions for the given inferred file id.
+/// \param NumFileIDs the number of file ids that are defined for this
+/// function.
+std::error_code RawCoverageMappingReader::readMappingRegionsSubArray(
+    std::vector<CounterMappingRegion> &MappingRegions, unsigned InferredFileID,
+    size_t NumFileIDs) {
+  uint64_t NumRegions;
+  if (auto Err = readSize(NumRegions))
+    return Err;
+  unsigned LineStart = 0;
+  for (size_t I = 0; I < NumRegions; ++I) {
+    Counter C;
+    CounterMappingRegion::RegionKind Kind = CounterMappingRegion::CodeRegion;
+
+    // Read the combined counter + region kind.
+    uint64_t EncodedCounterAndRegion;
+    if (auto Err = readIntMax(EncodedCounterAndRegion,
+                              std::numeric_limits<unsigned>::max()))
+      return Err;
+    unsigned Tag = EncodedCounterAndRegion & Counter::EncodingTagMask;
+    uint64_t ExpandedFileID = 0;
+    if (Tag != Counter::Zero) {
+      if (auto Err = decodeCounter(EncodedCounterAndRegion, C))
+        return Err;
+    } else {
+      // Is it an expansion region?
+      if (EncodedCounterAndRegion & EncodingExpansionRegionBit) {
+        Kind = CounterMappingRegion::ExpansionRegion;
+        ExpandedFileID = EncodedCounterAndRegion >>
+                         Counter::EncodingCounterTagAndExpansionRegionTagBits;
+        if (ExpandedFileID >= NumFileIDs)
+          return coveragemap_error::malformed;
+      } else {
+        switch (EncodedCounterAndRegion >>
+                Counter::EncodingCounterTagAndExpansionRegionTagBits) {
+        case CounterMappingRegion::CodeRegion:
+          // Don't do anything when we have a code region with a zero counter.
+          break;
+        case CounterMappingRegion::SkippedRegion:
+          Kind = CounterMappingRegion::SkippedRegion;
+          break;
+        default:
+          return coveragemap_error::malformed;
+        }
+      }
+    }
+
+    // Read the source range.
+    uint64_t LineStartDelta, ColumnStart, NumLines, ColumnEnd;
+    if (auto Err =
+            readIntMax(LineStartDelta, std::numeric_limits<unsigned>::max()))
+      return Err;
+    if (auto Err = readULEB128(ColumnStart))
+      return Err;
+    if (ColumnStart > std::numeric_limits<unsigned>::max())
+      return coveragemap_error::malformed;
+    if (auto Err = readIntMax(NumLines, std::numeric_limits<unsigned>::max()))
+      return Err;
+    if (auto Err = readIntMax(ColumnEnd, std::numeric_limits<unsigned>::max()))
+      return Err;
+    LineStart += LineStartDelta;
+    // Adjust the column locations for the empty regions that are supposed to
+    // cover whole lines. Those regions should be encoded with the
+    // column range (1 -> std::numeric_limits<unsigned>::max()), but because
+    // the encoded std::numeric_limits<unsigned>::max() is several bytes long,
+    // we set the column range to (0 -> 0) to ensure that the column start and
+    // column end take up one byte each.
+    // The std::numeric_limits<unsigned>::max() is used to represent a column
+    // position at the end of the line without knowing the length of that line.
+    if (ColumnStart == 0 && ColumnEnd == 0) {
+      ColumnStart = 1;
+      ColumnEnd = std::numeric_limits<unsigned>::max();
+    }
+
+    DEBUG({
+      dbgs() << "Counter in file " << InferredFileID << " " << LineStart << ":"
+             << ColumnStart << " -> " << (LineStart + NumLines) << ":"
+             << ColumnEnd << ", ";
+      if (Kind == CounterMappingRegion::ExpansionRegion)
+        dbgs() << "Expands to file " << ExpandedFileID;
+      else
+        CounterMappingContext(Expressions).dump(C, dbgs());
+      dbgs() << "\n";
+    });
+
+    MappingRegions.push_back(CounterMappingRegion(
+        C, InferredFileID, ExpandedFileID, LineStart, ColumnStart,
+        LineStart + NumLines, ColumnEnd, Kind));
+  }
+  return std::error_code();
+}
+
+std::error_code RawCoverageMappingReader::read() {
+
+  // Read the virtual file mapping.
+  llvm::SmallVector<unsigned, 8> VirtualFileMapping;
+  uint64_t NumFileMappings;
+  if (auto Err = readSize(NumFileMappings))
+    return Err;
+  for (size_t I = 0; I < NumFileMappings; ++I) {
+    uint64_t FilenameIndex;
+    if (auto Err = readIntMax(FilenameIndex, TranslationUnitFilenames.size()))
+      return Err;
+    VirtualFileMapping.push_back(FilenameIndex);
+  }
+
+  // Construct the files using unique filenames and virtual file mapping.
+  for (auto I : VirtualFileMapping) {
+    Filenames.push_back(TranslationUnitFilenames[I]);
+  }
+
+  // Read the expressions.
+  uint64_t NumExpressions;
+  if (auto Err = readSize(NumExpressions))
+    return Err;
+  // Create an array of dummy expressions that get the proper counters
+  // when the expressions are read, and the proper kinds when the counters
+  // are decoded.
+  Expressions.resize(
+      NumExpressions,
+      CounterExpression(CounterExpression::Subtract, Counter(), Counter()));
+  for (size_t I = 0; I < NumExpressions; ++I) {
+    if (auto Err = readCounter(Expressions[I].LHS))
+      return Err;
+    if (auto Err = readCounter(Expressions[I].RHS))
+      return Err;
+  }
+
+  // Read the mapping regions sub-arrays.
+  for (unsigned InferredFileID = 0, S = VirtualFileMapping.size();
+       InferredFileID < S; ++InferredFileID) {
+    if (auto Err = readMappingRegionsSubArray(MappingRegions, InferredFileID,
+                                              VirtualFileMapping.size()))
+      return Err;
+  }
+
+  // Set the counters for the expansion regions.
+  // i.e. Counter of expansion region = counter of the first region
+  // from the expanded file.
+  // Perform multiple passes to correctly propagate the counters through
+  // all the nested expansion regions.
+  SmallVector<CounterMappingRegion *, 8> FileIDExpansionRegionMapping;
+  FileIDExpansionRegionMapping.resize(VirtualFileMapping.size(), nullptr);
+  for (unsigned Pass = 1, S = VirtualFileMapping.size(); Pass < S; ++Pass) {
+    for (auto &R : MappingRegions) {
+      if (R.Kind != CounterMappingRegion::ExpansionRegion)
+        continue;
+      assert(!FileIDExpansionRegionMapping[R.ExpandedFileID]);
+      FileIDExpansionRegionMapping[R.ExpandedFileID] = &R;
+    }
+    for (auto &R : MappingRegions) {
+      if (FileIDExpansionRegionMapping[R.FileID]) {
+        FileIDExpansionRegionMapping[R.FileID]->Count = R.Count;
+        FileIDExpansionRegionMapping[R.FileID] = nullptr;
+      }
+    }
+  }
+
+  return std::error_code();
+}
+
+std::error_code InstrProfSymtab::create(SectionRef &Section) {
+  if (auto Err = Section.getContents(Data))
+    return Err;
+  Address = Section.getAddress();
+  return std::error_code();
+}
+
+StringRef InstrProfSymtab::getFuncName(uint64_t Pointer, size_t Size) {
+  if (Pointer < Address)
+    return StringRef();
+  auto Offset = Pointer - Address;
+  if (Offset + Size > Data.size())
+    return StringRef();
+  return Data.substr(Pointer - Address, Size);
+}
+
+namespace {
+struct CovMapFuncRecordReader {
+  // The interface to read coverage mapping function records for
+  // a module. \p Buf is a reference to the buffer pointer pointing
+  // to the \c CovHeader of coverage mapping data associated with
+  // the module.
+  virtual std::error_code readFunctionRecords(const char *&Buf,
+                                              const char *End) = 0;
+  virtual ~CovMapFuncRecordReader() {}
+  template <class IntPtrT, support::endianness Endian>
+  static std::unique_ptr<CovMapFuncRecordReader>
+  get(coverage::CovMapVersion Version, InstrProfSymtab &P,
+      std::vector<BinaryCoverageReader::ProfileMappingRecord> &R,
+      std::vector<StringRef> &F);
+};
+
+// A class for reading coverage mapping function records for a module.
+template <coverage::CovMapVersion Version, class IntPtrT,
+          support::endianness Endian>
+class VersionedCovMapFuncRecordReader : public CovMapFuncRecordReader {
+  typedef typename coverage::CovMapTraits<
+      Version, IntPtrT>::CovMapFuncRecordType FuncRecordType;
+  typedef typename coverage::CovMapTraits<Version, IntPtrT>::NameRefType
+      NameRefType;
+
+  llvm::DenseSet<NameRefType> UniqueFunctionMappingData;
+  InstrProfSymtab &ProfileNames;
+  std::vector<StringRef> &Filenames;
+  std::vector<BinaryCoverageReader::ProfileMappingRecord> &Records;
+
+public:
+  VersionedCovMapFuncRecordReader(
+      InstrProfSymtab &P,
+      std::vector<BinaryCoverageReader::ProfileMappingRecord> &R,
+      std::vector<StringRef> &F)
+      : ProfileNames(P), Filenames(F), Records(R) {}
+  ~VersionedCovMapFuncRecordReader() override {}
+
+  std::error_code readFunctionRecords(const char *&Buf,
+                                      const char *End) override {
+    using namespace support;
+    if (Buf + sizeof(CovMapHeader) > End)
+      return coveragemap_error::malformed;
+    auto CovHeader = reinterpret_cast<const coverage::CovMapHeader *>(Buf);
+    uint32_t NRecords = CovHeader->getNRecords<Endian>();
+    uint32_t FilenamesSize = CovHeader->getFilenamesSize<Endian>();
+    uint32_t CoverageSize = CovHeader->getCoverageSize<Endian>();
+    assert((CovMapVersion)CovHeader->getVersion<Endian>() == Version);
+    Buf = reinterpret_cast<const char *>(CovHeader + 1);
+
+    // Skip past the function records, saving the start and end for later.
+    const char *FunBuf = Buf;
+    Buf += NRecords * sizeof(FuncRecordType);
+    const char *FunEnd = Buf;
+
+    // Get the filenames.
+    if (Buf + FilenamesSize > End)
+      return coveragemap_error::malformed;
+    size_t FilenamesBegin = Filenames.size();
+    RawCoverageFilenamesReader Reader(StringRef(Buf, FilenamesSize), Filenames);
+    if (auto Err = Reader.read())
+      return Err;
+    Buf += FilenamesSize;
+
+    // We'll read the coverage mapping records in the loop below.
+    const char *CovBuf = Buf;
+    Buf += CoverageSize;
+    const char *CovEnd = Buf;
+
+    if (Buf > End)
+      return coveragemap_error::malformed;
+    // Each coverage map has an alignment of 8, so we need to adjust alignment
+    // before reading the next map.
+    Buf += alignmentAdjustment(Buf, 8);
+
+    auto CFR = reinterpret_cast<const FuncRecordType *>(FunBuf);
+    while ((const char *)CFR < FunEnd) {
+      // Read the function information
+      uint32_t DataSize = CFR->template getDataSize<Endian>();
+      uint64_t FuncHash = CFR->template getFuncHash<Endian>();
+
+      // Now use that to read the coverage data.
+      if (CovBuf + DataSize > CovEnd)
+        return coveragemap_error::malformed;
+      auto Mapping = StringRef(CovBuf, DataSize);
+      CovBuf += DataSize;
+
+      // Ignore this record if we already have a record that points to the same
+      // function name. This is useful to ignore the redundant records for the
+      // functions with ODR linkage.
+      NameRefType NameRef = CFR->template getFuncNameRef<Endian>();
+      if (!UniqueFunctionMappingData.insert(NameRef).second) {
+        CFR++;
+        continue;
+      }
+
+      StringRef FuncName;
+      if (std::error_code EC =
+              CFR->template getFuncName<Endian>(ProfileNames, FuncName))
+        return EC;
+      Records.push_back(BinaryCoverageReader::ProfileMappingRecord(
+          Version, FuncName, FuncHash, Mapping, FilenamesBegin,
+          Filenames.size() - FilenamesBegin));
+      CFR++;
+    }
+    return std::error_code();
+  }
+};
+} // end anonymous namespace
+
+template <class IntPtrT, support::endianness Endian>
+std::unique_ptr<CovMapFuncRecordReader> CovMapFuncRecordReader::get(
+    coverage::CovMapVersion Version, InstrProfSymtab &P,
+    std::vector<BinaryCoverageReader::ProfileMappingRecord> &R,
+    std::vector<StringRef> &F) {
+  using namespace coverage;
+  switch (Version) {
+  case CovMapVersion::Version1:
+    return llvm::make_unique<VersionedCovMapFuncRecordReader<
+        CovMapVersion::Version1, IntPtrT, Endian>>(P, R, F);
+  case CovMapVersion::Version2:
+    // Decompress the name data.
+    P.create(P.getNameData());
+    return llvm::make_unique<VersionedCovMapFuncRecordReader<
+        CovMapVersion::Version2, IntPtrT, Endian>>(P, R, F);
+  }
+  llvm_unreachable("Unsupported version");
+}
+
+template <typename T, support::endianness Endian>
+static std::error_code readCoverageMappingData(
+    InstrProfSymtab &ProfileNames, StringRef Data,
+    std::vector<BinaryCoverageReader::ProfileMappingRecord> &Records,
+    std::vector<StringRef> &Filenames) {
+  using namespace coverage;
+  // Read the records in the coverage data section.
+  auto CovHeader =
+      reinterpret_cast<const coverage::CovMapHeader *>(Data.data());
+  CovMapVersion Version = (CovMapVersion)CovHeader->getVersion<Endian>();
+  if (Version > coverage::CovMapVersion::CurrentVersion)
+    return coveragemap_error::unsupported_version;
+  std::unique_ptr<CovMapFuncRecordReader> Reader =
+      CovMapFuncRecordReader::get<T, Endian>(Version, ProfileNames, Records,
+                                             Filenames);
+  for (const char *Buf = Data.data(), *End = Buf + Data.size(); Buf < End;) {
+    if (std::error_code EC = Reader->readFunctionRecords(Buf, End))
+      return EC;
+  }
+  return std::error_code();
+}
+static const char *TestingFormatMagic = "llvmcovmtestdata";
+
+static std::error_code loadTestingFormat(StringRef Data,
+                                         InstrProfSymtab &ProfileNames,
+                                         StringRef &CoverageMapping,
+                                         uint8_t &BytesInAddress,
+                                         support::endianness &Endian) {
+  BytesInAddress = 8;
+  Endian = support::endianness::little;
+
+  Data = Data.substr(StringRef(TestingFormatMagic).size());
+  if (Data.size() < 1)
+    return coveragemap_error::truncated;
+  unsigned N = 0;
+  auto ProfileNamesSize =
+      decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N);
+  if (N > Data.size())
+    return coveragemap_error::malformed;
+  Data = Data.substr(N);
+  if (Data.size() < 1)
+    return coveragemap_error::truncated;
+  N = 0;
+  uint64_t Address =
+      decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N);
+  if (N > Data.size())
+    return coveragemap_error::malformed;
+  Data = Data.substr(N);
+  if (Data.size() < ProfileNamesSize)
+    return coveragemap_error::malformed;
+  ProfileNames.create(Data.substr(0, ProfileNamesSize), Address);
+  CoverageMapping = Data.substr(ProfileNamesSize);
+  return std::error_code();
+}
+
+static ErrorOr<SectionRef> lookupSection(ObjectFile &OF, StringRef Name) {
+  StringRef FoundName;
+  for (const auto &Section : OF.sections()) {
+    if (auto EC = Section.getName(FoundName))
+      return EC;
+    if (FoundName == Name)
+      return Section;
+  }
+  return coveragemap_error::no_data_found;
+}
+
+static std::error_code
+loadBinaryFormat(MemoryBufferRef ObjectBuffer, InstrProfSymtab &ProfileNames,
+                 StringRef &CoverageMapping, uint8_t &BytesInAddress,
+                 support::endianness &Endian, StringRef Arch) {
+  auto BinOrErr = object::createBinary(ObjectBuffer);
+  if (!BinOrErr)
+    return errorToErrorCode(BinOrErr.takeError());
+  auto Bin = std::move(BinOrErr.get());
+  std::unique_ptr<ObjectFile> OF;
+  if (auto *Universal = dyn_cast<object::MachOUniversalBinary>(Bin.get())) {
+    // If we have a universal binary, try to look up the object for the
+    // appropriate architecture.
+    auto ObjectFileOrErr = Universal->getObjectForArch(Arch);
+    if (std::error_code EC = ObjectFileOrErr.getError())
+      return EC;
+    OF = std::move(ObjectFileOrErr.get());
+  } else if (isa<object::ObjectFile>(Bin.get())) {
+    // For any other object file, upcast and take ownership.
+    OF.reset(cast<object::ObjectFile>(Bin.release()));
+    // If we've asked for a particular arch, make sure they match.
+    if (!Arch.empty() && OF->getArch() != Triple(Arch).getArch())
+      return object_error::arch_not_found;
+  } else
+    // We can only handle object files.
+    return coveragemap_error::malformed;
+
+  // The coverage uses native pointer sizes for the object it's written in.
+  BytesInAddress = OF->getBytesInAddress();
+  Endian = OF->isLittleEndian() ? support::endianness::little
+                                : support::endianness::big;
+
+  // Look for the sections that we are interested in.
+  auto NamesSection = lookupSection(*OF, getInstrProfNameSectionName(false));
+  if (auto EC = NamesSection.getError())
+    return EC;
+  auto CoverageSection =
+      lookupSection(*OF, getInstrProfCoverageSectionName(false));
+  if (auto EC = CoverageSection.getError())
+    return EC;
+
+  // Get the contents of the given sections.
+  if (std::error_code EC = CoverageSection->getContents(CoverageMapping))
+    return EC;
+  if (std::error_code EC = ProfileNames.create(*NamesSection))
+    return EC;
+
+  return std::error_code();
+}
+
+ErrorOr<std::unique_ptr<BinaryCoverageReader>>
+BinaryCoverageReader::create(std::unique_ptr<MemoryBuffer> &ObjectBuffer,
+                             StringRef Arch) {
+  std::unique_ptr<BinaryCoverageReader> Reader(new BinaryCoverageReader());
+
+  StringRef Coverage;
+  uint8_t BytesInAddress;
+  support::endianness Endian;
+  std::error_code EC;
+  if (ObjectBuffer->getBuffer().startswith(TestingFormatMagic))
+    // This is a special format used for testing.
+    EC = loadTestingFormat(ObjectBuffer->getBuffer(), Reader->ProfileNames,
+                           Coverage, BytesInAddress, Endian);
+  else
+    EC = loadBinaryFormat(ObjectBuffer->getMemBufferRef(), Reader->ProfileNames,
+                          Coverage, BytesInAddress, Endian, Arch);
+  if (EC)
+    return EC;
+
+  if (BytesInAddress == 4 && Endian == support::endianness::little)
+    EC = readCoverageMappingData<uint32_t, support::endianness::little>(
+        Reader->ProfileNames, Coverage, Reader->MappingRecords,
+        Reader->Filenames);
+  else if (BytesInAddress == 4 && Endian == support::endianness::big)
+    EC = readCoverageMappingData<uint32_t, support::endianness::big>(
+        Reader->ProfileNames, Coverage, Reader->MappingRecords,
+        Reader->Filenames);
+  else if (BytesInAddress == 8 && Endian == support::endianness::little)
+    EC = readCoverageMappingData<uint64_t, support::endianness::little>(
+        Reader->ProfileNames, Coverage, Reader->MappingRecords,
+        Reader->Filenames);
+  else if (BytesInAddress == 8 && Endian == support::endianness::big)
+    EC = readCoverageMappingData<uint64_t, support::endianness::big>(
+        Reader->ProfileNames, Coverage, Reader->MappingRecords,
+        Reader->Filenames);
+  else
+    return coveragemap_error::malformed;
+  if (EC)
+    return EC;
+  return std::move(Reader);
+}
+
+std::error_code
+BinaryCoverageReader::readNextRecord(CoverageMappingRecord &Record) {
+  if (CurrentRecord >= MappingRecords.size())
+    return coveragemap_error::eof;
+
+  FunctionsFilenames.clear();
+  Expressions.clear();
+  MappingRegions.clear();
+  auto &R = MappingRecords[CurrentRecord];
+  RawCoverageMappingReader Reader(
+      R.CoverageMapping,
+      makeArrayRef(Filenames).slice(R.FilenamesBegin, R.FilenamesSize),
+      FunctionsFilenames, Expressions, MappingRegions);
+  if (auto Err = Reader.read())
+    return Err;
+
+  Record.FunctionName = R.FunctionName;
+  Record.FunctionHash = R.FunctionHash;
+  Record.Filenames = FunctionsFilenames;
+  Record.Expressions = Expressions;
+  Record.MappingRegions = MappingRegions;
+
+  ++CurrentRecord;
+  return std::error_code();
+}