Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 818 insertions, 0 deletions

diff --git a/clang-r353983/include/llvm/ProfileData/Coverage/CoverageMapping.h b/clang-r353983/include/llvm/ProfileData/Coverage/CoverageMapping.h
new file mode 100644
index 00000000..11758ac4
--- /dev/null
+++ b/clang-r353983/include/llvm/ProfileData/Coverage/CoverageMapping.h
@@ -0,0 +1,818 @@
+//===- CoverageMapping.h - Code coverage mapping support --------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Code coverage mapping data is generated by clang and read by
+// llvm-cov to show code coverage statistics for a file.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPING_H
+#define LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPING_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/None.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/ProfileData/InstrProf.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cassert>
+#include <cstdint>
+#include <iterator>
+#include <memory>
+#include <string>
+#include <system_error>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+namespace llvm {
+
+class IndexedInstrProfReader;
+
+namespace coverage {
+
+class CoverageMappingReader;
+struct CoverageMappingRecord;
+
+enum class coveragemap_error {
+  success = 0,
+  eof,
+  no_data_found,
+  unsupported_version,
+  truncated,
+  malformed
+};
+
+const std::error_category &coveragemap_category();
+
+inline std::error_code make_error_code(coveragemap_error E) {
+  return std::error_code(static_cast<int>(E), coveragemap_category());
+}
+
+class CoverageMapError : public ErrorInfo<CoverageMapError> {
+public:
+  CoverageMapError(coveragemap_error Err) : Err(Err) {
+    assert(Err != coveragemap_error::success && "Not an error");
+  }
+
+  std::string message() const override;
+
+  void log(raw_ostream &OS) const override { OS << message(); }
+
+  std::error_code convertToErrorCode() const override {
+    return make_error_code(Err);
+  }
+
+  coveragemap_error get() const { return Err; }
+
+  static char ID;
+
+private:
+  coveragemap_error Err;
+};
+
+/// A Counter is an abstract value that describes how to compute the
+/// execution count for a region of code using the collected profile count data.
+struct Counter {
+  enum CounterKind { Zero, CounterValueReference, Expression };
+  static const unsigned EncodingTagBits = 2;
+  static const unsigned EncodingTagMask = 0x3;
+  static const unsigned EncodingCounterTagAndExpansionRegionTagBits =
+      EncodingTagBits + 1;
+
+private:
+  CounterKind Kind = Zero;
+  unsigned ID = 0;
+
+  Counter(CounterKind Kind, unsigned ID) : Kind(Kind), ID(ID) {}
+
+public:
+  Counter() = default;
+
+  CounterKind getKind() const { return Kind; }
+
+  bool isZero() const { return Kind == Zero; }
+
+  bool isExpression() const { return Kind == Expression; }
+
+  unsigned getCounterID() const { return ID; }
+
+  unsigned getExpressionID() const { return ID; }
+
+  friend bool operator==(const Counter &LHS, const Counter &RHS) {
+    return LHS.Kind == RHS.Kind && LHS.ID == RHS.ID;
+  }
+
+  friend bool operator!=(const Counter &LHS, const Counter &RHS) {
+    return !(LHS == RHS);
+  }
+
+  friend bool operator<(const Counter &LHS, const Counter &RHS) {
+    return std::tie(LHS.Kind, LHS.ID) < std::tie(RHS.Kind, RHS.ID);
+  }
+
+  /// Return the counter that represents the number zero.
+  static Counter getZero() { return Counter(); }
+
+  /// Return the counter that corresponds to a specific profile counter.
+  static Counter getCounter(unsigned CounterId) {
+    return Counter(CounterValueReference, CounterId);
+  }
+
+  /// Return the counter that corresponds to a specific addition counter
+  /// expression.
+  static Counter getExpression(unsigned ExpressionId) {
+    return Counter(Expression, ExpressionId);
+  }
+};
+
+/// A Counter expression is a value that represents an arithmetic operation
+/// with two counters.
+struct CounterExpression {
+  enum ExprKind { Subtract, Add };
+  ExprKind Kind;
+  Counter LHS, RHS;
+
+  CounterExpression(ExprKind Kind, Counter LHS, Counter RHS)
+      : Kind(Kind), LHS(LHS), RHS(RHS) {}
+};
+
+/// A Counter expression builder is used to construct the counter expressions.
+/// It avoids unnecessary duplication and simplifies algebraic expressions.
+class CounterExpressionBuilder {
+  /// A list of all the counter expressions
+  std::vector<CounterExpression> Expressions;
+
+  /// A lookup table for the index of a given expression.
+  DenseMap<CounterExpression, unsigned> ExpressionIndices;
+
+  /// Return the counter which corresponds to the given expression.
+  ///
+  /// If the given expression is already stored in the builder, a counter
+  /// that references that expression is returned. Otherwise, the given
+  /// expression is added to the builder's collection of expressions.
+  Counter get(const CounterExpression &E);
+
+  /// Represents a term in a counter expression tree.
+  struct Term {
+    unsigned CounterID;
+    int Factor;
+
+    Term(unsigned CounterID, int Factor)
+        : CounterID(CounterID), Factor(Factor) {}
+  };
+
+  /// Gather the terms of the expression tree for processing.
+  ///
+  /// This collects each addition and subtraction referenced by the counter into
+  /// a sequence that can be sorted and combined to build a simplified counter
+  /// expression.
+  void extractTerms(Counter C, int Sign, SmallVectorImpl<Term> &Terms);
+
+  /// Simplifies the given expression tree
+  /// by getting rid of algebraically redundant operations.
+  Counter simplify(Counter ExpressionTree);
+
+public:
+  ArrayRef<CounterExpression> getExpressions() const { return Expressions; }
+
+  /// Return a counter that represents the expression that adds LHS and RHS.
+  Counter add(Counter LHS, Counter RHS);
+
+  /// Return a counter that represents the expression that subtracts RHS from
+  /// LHS.
+  Counter subtract(Counter LHS, Counter RHS);
+};
+
+using LineColPair = std::pair<unsigned, unsigned>;
+
+/// A Counter mapping region associates a source range with a specific counter.
+struct CounterMappingRegion {
+  enum RegionKind {
+    /// A CodeRegion associates some code with a counter
+    CodeRegion,
+
+    /// An ExpansionRegion represents a file expansion region that associates
+    /// a source range with the expansion of a virtual source file, such as
+    /// for a macro instantiation or #include file.
+    ExpansionRegion,
+
+    /// A SkippedRegion represents a source range with code that was skipped
+    /// by a preprocessor or similar means.
+    SkippedRegion,
+
+    /// A GapRegion is like a CodeRegion, but its count is only set as the
+    /// line execution count when its the only region in the line.
+    GapRegion
+  };
+
+  Counter Count;
+  unsigned FileID, ExpandedFileID;
+  unsigned LineStart, ColumnStart, LineEnd, ColumnEnd;
+  RegionKind Kind;
+
+  CounterMappingRegion(Counter Count, unsigned FileID, unsigned ExpandedFileID,
+                       unsigned LineStart, unsigned ColumnStart,
+                       unsigned LineEnd, unsigned ColumnEnd, RegionKind Kind)
+      : Count(Count), FileID(FileID), ExpandedFileID(ExpandedFileID),
+        LineStart(LineStart), ColumnStart(ColumnStart), LineEnd(LineEnd),
+        ColumnEnd(ColumnEnd), Kind(Kind) {}
+
+  static CounterMappingRegion
+  makeRegion(Counter Count, unsigned FileID, unsigned LineStart,
+             unsigned ColumnStart, unsigned LineEnd, unsigned ColumnEnd) {
+    return CounterMappingRegion(Count, FileID, 0, LineStart, ColumnStart,
+                                LineEnd, ColumnEnd, CodeRegion);
+  }
+
+  static CounterMappingRegion
+  makeExpansion(unsigned FileID, unsigned ExpandedFileID, unsigned LineStart,
+                unsigned ColumnStart, unsigned LineEnd, unsigned ColumnEnd) {
+    return CounterMappingRegion(Counter(), FileID, ExpandedFileID, LineStart,
+                                ColumnStart, LineEnd, ColumnEnd,
+                                ExpansionRegion);
+  }
+
+  static CounterMappingRegion
+  makeSkipped(unsigned FileID, unsigned LineStart, unsigned ColumnStart,
+              unsigned LineEnd, unsigned ColumnEnd) {
+    return CounterMappingRegion(Counter(), FileID, 0, LineStart, ColumnStart,
+                                LineEnd, ColumnEnd, SkippedRegion);
+  }
+
+  static CounterMappingRegion
+  makeGapRegion(Counter Count, unsigned FileID, unsigned LineStart,
+                unsigned ColumnStart, unsigned LineEnd, unsigned ColumnEnd) {
+    return CounterMappingRegion(Count, FileID, 0, LineStart, ColumnStart,
+                                LineEnd, (1U << 31) | ColumnEnd, GapRegion);
+  }
+
+  inline LineColPair startLoc() const {
+    return LineColPair(LineStart, ColumnStart);
+  }
+
+  inline LineColPair endLoc() const { return LineColPair(LineEnd, ColumnEnd); }
+};
+
+/// Associates a source range with an execution count.
+struct CountedRegion : public CounterMappingRegion {
+  uint64_t ExecutionCount;
+
+  CountedRegion(const CounterMappingRegion &R, uint64_t ExecutionCount)
+      : CounterMappingRegion(R), ExecutionCount(ExecutionCount) {}
+};
+
+/// A Counter mapping context is used to connect the counters, expressions
+/// and the obtained counter values.
+class CounterMappingContext {
+  ArrayRef<CounterExpression> Expressions;
+  ArrayRef<uint64_t> CounterValues;
+
+public:
+  CounterMappingContext(ArrayRef<CounterExpression> Expressions,
+                        ArrayRef<uint64_t> CounterValues = None)
+      : Expressions(Expressions), CounterValues(CounterValues) {}
+
+  void setCounts(ArrayRef<uint64_t> Counts) { CounterValues = Counts; }
+
+  void dump(const Counter &C, raw_ostream &OS) const;
+  void dump(const Counter &C) const { dump(C, dbgs()); }
+
+  /// Return the number of times that a region of code associated with this
+  /// counter was executed.
+  Expected<int64_t> evaluate(const Counter &C) const;
+};
+
+/// Code coverage information for a single function.
+struct FunctionRecord {
+  /// Raw function name.
+  std::string Name;
+  /// Associated files.
+  std::vector<std::string> Filenames;
+  /// Regions in the function along with their counts.
+  std::vector<CountedRegion> CountedRegions;
+  /// The number of times this function was executed.
+  uint64_t ExecutionCount;
+
+  FunctionRecord(StringRef Name, ArrayRef<StringRef> Filenames)
+      : Name(Name), Filenames(Filenames.begin(), Filenames.end()) {}
+
+  FunctionRecord(FunctionRecord &&FR) = default;
+  FunctionRecord &operator=(FunctionRecord &&) = default;
+
+  void pushRegion(CounterMappingRegion Region, uint64_t Count) {
+    if (CountedRegions.empty())
+      ExecutionCount = Count;
+    CountedRegions.emplace_back(Region, Count);
+  }
+};
+
+/// Iterator over Functions, optionally filtered to a single file.
+class FunctionRecordIterator
+    : public iterator_facade_base<FunctionRecordIterator,
+                                  std::forward_iterator_tag, FunctionRecord> {
+  ArrayRef<FunctionRecord> Records;
+  ArrayRef<FunctionRecord>::iterator Current;
+  StringRef Filename;
+
+  /// Skip records whose primary file is not \c Filename.
+  void skipOtherFiles();
+
+public:
+  FunctionRecordIterator(ArrayRef<FunctionRecord> Records_,
+                         StringRef Filename = "")
+      : Records(Records_), Current(Records.begin()), Filename(Filename) {
+    skipOtherFiles();
+  }
+
+  FunctionRecordIterator() : Current(Records.begin()) {}
+
+  bool operator==(const FunctionRecordIterator &RHS) const {
+    return Current == RHS.Current && Filename == RHS.Filename;
+  }
+
+  const FunctionRecord &operator*() const { return *Current; }
+
+  FunctionRecordIterator &operator++() {
+    assert(Current != Records.end() && "incremented past end");
+    ++Current;
+    skipOtherFiles();
+    return *this;
+  }
+};
+
+/// Coverage information for a macro expansion or #included file.
+///
+/// When covered code has pieces that can be expanded for more detail, such as a
+/// preprocessor macro use and its definition, these are represented as
+/// expansions whose coverage can be looked up independently.
+struct ExpansionRecord {
+  /// The abstract file this expansion covers.
+  unsigned FileID;
+  /// The region that expands to this record.
+  const CountedRegion &Region;
+  /// Coverage for the expansion.
+  const FunctionRecord &Function;
+
+  ExpansionRecord(const CountedRegion &Region,
+                  const FunctionRecord &Function)
+      : FileID(Region.ExpandedFileID), Region(Region), Function(Function) {}
+};
+
+/// The execution count information starting at a point in a file.
+///
+/// A sequence of CoverageSegments gives execution counts for a file in format
+/// that's simple to iterate through for processing.
+struct CoverageSegment {
+  /// The line where this segment begins.
+  unsigned Line;
+  /// The column where this segment begins.
+  unsigned Col;
+  /// The execution count, or zero if no count was recorded.
+  uint64_t Count;
+  /// When false, the segment was uninstrumented or skipped.
+  bool HasCount;
+  /// Whether this enters a new region or returns to a previous count.
+  bool IsRegionEntry;
+  /// Whether this enters a gap region.
+  bool IsGapRegion;
+
+  CoverageSegment(unsigned Line, unsigned Col, bool IsRegionEntry)
+      : Line(Line), Col(Col), Count(0), HasCount(false),
+        IsRegionEntry(IsRegionEntry), IsGapRegion(false) {}
+
+  CoverageSegment(unsigned Line, unsigned Col, uint64_t Count,
+                  bool IsRegionEntry, bool IsGapRegion = false)
+      : Line(Line), Col(Col), Count(Count), HasCount(true),
+        IsRegionEntry(IsRegionEntry), IsGapRegion(IsGapRegion) {}
+
+  friend bool operator==(const CoverageSegment &L, const CoverageSegment &R) {
+    return std::tie(L.Line, L.Col, L.Count, L.HasCount, L.IsRegionEntry,
+                    L.IsGapRegion) == std::tie(R.Line, R.Col, R.Count,
+                                               R.HasCount, R.IsRegionEntry,
+                                               R.IsGapRegion);
+  }
+};
+
+/// An instantiation group contains a \c FunctionRecord list, such that each
+/// record corresponds to a distinct instantiation of the same function.
+///
+/// Note that it's possible for a function to have more than one instantiation
+/// (consider C++ template specializations or static inline functions).
+class InstantiationGroup {
+  friend class CoverageMapping;
+
+  unsigned Line;
+  unsigned Col;
+  std::vector<const FunctionRecord *> Instantiations;
+
+  InstantiationGroup(unsigned Line, unsigned Col,
+                     std::vector<const FunctionRecord *> Instantiations)
+      : Line(Line), Col(Col), Instantiations(std::move(Instantiations)) {}
+
+public:
+  InstantiationGroup(const InstantiationGroup &) = delete;
+  InstantiationGroup(InstantiationGroup &&) = default;
+
+  /// Get the number of instantiations in this group.
+  size_t size() const { return Instantiations.size(); }
+
+  /// Get the line where the common function was defined.
+  unsigned getLine() const { return Line; }
+
+  /// Get the column where the common function was defined.
+  unsigned getColumn() const { return Col; }
+
+  /// Check if the instantiations in this group have a common mangled name.
+  bool hasName() const {
+    for (unsigned I = 1, E = Instantiations.size(); I < E; ++I)
+      if (Instantiations[I]->Name != Instantiations[0]->Name)
+        return false;
+    return true;
+  }
+
+  /// Get the common mangled name for instantiations in this group.
+  StringRef getName() const {
+    assert(hasName() && "Instantiations don't have a shared name");
+    return Instantiations[0]->Name;
+  }
+
+  /// Get the total execution count of all instantiations in this group.
+  uint64_t getTotalExecutionCount() const {
+    uint64_t Count = 0;
+    for (const FunctionRecord *F : Instantiations)
+      Count += F->ExecutionCount;
+    return Count;
+  }
+
+  /// Get the instantiations in this group.
+  ArrayRef<const FunctionRecord *> getInstantiations() const {
+    return Instantiations;
+  }
+};
+
+/// Coverage information to be processed or displayed.
+///
+/// This represents the coverage of an entire file, expansion, or function. It
+/// provides a sequence of CoverageSegments to iterate through, as well as the
+/// list of expansions that can be further processed.
+class CoverageData {
+  friend class CoverageMapping;
+
+  std::string Filename;
+  std::vector<CoverageSegment> Segments;
+  std::vector<ExpansionRecord> Expansions;
+
+public:
+  CoverageData() = default;
+
+  CoverageData(StringRef Filename) : Filename(Filename) {}
+
+  /// Get the name of the file this data covers.
+  StringRef getFilename() const { return Filename; }
+
+  /// Get an iterator over the coverage segments for this object. The segments
+  /// are guaranteed to be uniqued and sorted by location.
+  std::vector<CoverageSegment>::const_iterator begin() const {
+    return Segments.begin();
+  }
+
+  std::vector<CoverageSegment>::const_iterator end() const {
+    return Segments.end();
+  }
+
+  bool empty() const { return Segments.empty(); }
+
+  /// Expansions that can be further processed.
+  ArrayRef<ExpansionRecord> getExpansions() const { return Expansions; }
+};
+
+/// The mapping of profile information to coverage data.
+///
+/// This is the main interface to get coverage information, using a profile to
+/// fill out execution counts.
+class CoverageMapping {
+  DenseMap<size_t, DenseSet<size_t>> RecordProvenance;
+  std::vector<FunctionRecord> Functions;
+  std::vector<std::pair<std::string, uint64_t>> FuncHashMismatches;
+
+  CoverageMapping() = default;
+
+  /// Add a function record corresponding to \p Record.
+  Error loadFunctionRecord(const CoverageMappingRecord &Record,
+                           IndexedInstrProfReader &ProfileReader);
+
+public:
+  CoverageMapping(const CoverageMapping &) = delete;
+  CoverageMapping &operator=(const CoverageMapping &) = delete;
+
+  /// Load the coverage mapping using the given readers.
+  static Expected<std::unique_ptr<CoverageMapping>>
+  load(ArrayRef<std::unique_ptr<CoverageMappingReader>> CoverageReaders,
+       IndexedInstrProfReader &ProfileReader);
+
+  /// Load the coverage mapping from the given object files and profile. If
+  /// \p Arches is non-empty, it must specify an architecture for each object.
+  static Expected<std::unique_ptr<CoverageMapping>>
+  load(ArrayRef<StringRef> ObjectFilenames, StringRef ProfileFilename,
+       ArrayRef<StringRef> Arches = None);
+
+  /// The number of functions that couldn't have their profiles mapped.
+  ///
+  /// This is a count of functions whose profile is out of date or otherwise
+  /// can't be associated with any coverage information.
+  unsigned getMismatchedCount() const { return FuncHashMismatches.size(); }
+
+  /// A hash mismatch occurs when a profile record for a symbol does not have
+  /// the same hash as a coverage mapping record for the same symbol. This
+  /// returns a list of hash mismatches, where each mismatch is a pair of the
+  /// symbol name and its coverage mapping hash.
+  ArrayRef<std::pair<std::string, uint64_t>> getHashMismatches() const {
+    return FuncHashMismatches;
+  }
+
+  /// Returns a lexicographically sorted, unique list of files that are
+  /// covered.
+  std::vector<StringRef> getUniqueSourceFiles() const;
+
+  /// Get the coverage for a particular file.
+  ///
+  /// The given filename must be the name as recorded in the coverage
+  /// information. That is, only names returned from getUniqueSourceFiles will
+  /// yield a result.
+  CoverageData getCoverageForFile(StringRef Filename) const;
+
+  /// Get the coverage for a particular function.
+  CoverageData getCoverageForFunction(const FunctionRecord &Function) const;
+
+  /// Get the coverage for an expansion within a coverage set.
+  CoverageData getCoverageForExpansion(const ExpansionRecord &Expansion) const;
+
+  /// Gets all of the functions covered by this profile.
+  iterator_range<FunctionRecordIterator> getCoveredFunctions() const {
+    return make_range(FunctionRecordIterator(Functions),
+                      FunctionRecordIterator());
+  }
+
+  /// Gets all of the functions in a particular file.
+  iterator_range<FunctionRecordIterator>
+  getCoveredFunctions(StringRef Filename) const {
+    return make_range(FunctionRecordIterator(Functions, Filename),
+                      FunctionRecordIterator());
+  }
+
+  /// Get the list of function instantiation groups in a particular file.
+  ///
+  /// Every instantiation group in a program is attributed to exactly one file:
+  /// the file in which the definition for the common function begins.
+  std::vector<InstantiationGroup>
+  getInstantiationGroups(StringRef Filename) const;
+};
+
+/// Coverage statistics for a single line.
+class LineCoverageStats {
+  uint64_t ExecutionCount;
+  bool HasMultipleRegions;
+  bool Mapped;
+  unsigned Line;
+  ArrayRef<const CoverageSegment *> LineSegments;
+  const CoverageSegment *WrappedSegment;
+
+  friend class LineCoverageIterator;
+  LineCoverageStats() = default;
+
+public:
+  LineCoverageStats(ArrayRef<const CoverageSegment *> LineSegments,
+                    const CoverageSegment *WrappedSegment, unsigned Line);
+
+  uint64_t getExecutionCount() const { return ExecutionCount; }
+
+  bool hasMultipleRegions() const { return HasMultipleRegions; }
+
+  bool isMapped() const { return Mapped; }
+
+  unsigned getLine() const { return Line; }
+
+  ArrayRef<const CoverageSegment *> getLineSegments() const {
+    return LineSegments;
+  }
+
+  const CoverageSegment *getWrappedSegment() const { return WrappedSegment; }
+};
+
+/// An iterator over the \c LineCoverageStats objects for lines described by
+/// a \c CoverageData instance.
+class LineCoverageIterator
+    : public iterator_facade_base<
+          LineCoverageIterator, std::forward_iterator_tag, LineCoverageStats> {
+public:
+  LineCoverageIterator(const CoverageData &CD)
+      : LineCoverageIterator(CD, CD.begin()->Line) {}
+
+  LineCoverageIterator(const CoverageData &CD, unsigned Line)
+      : CD(CD), WrappedSegment(nullptr), Next(CD.begin()), Ended(false),
+        Line(Line), Segments(), Stats() {
+    this->operator++();
+  }
+
+  bool operator==(const LineCoverageIterator &R) const {
+    return &CD == &R.CD && Next == R.Next && Ended == R.Ended;
+  }
+
+  const LineCoverageStats &operator*() const { return Stats; }
+
+  LineCoverageStats &operator*() { return Stats; }
+
+  LineCoverageIterator &operator++();
+
+  LineCoverageIterator getEnd() const {
+    auto EndIt = *this;
+    EndIt.Next = CD.end();
+    EndIt.Ended = true;
+    return EndIt;
+  }
+
+private:
+  const CoverageData &CD;
+  const CoverageSegment *WrappedSegment;
+  std::vector<CoverageSegment>::const_iterator Next;
+  bool Ended;
+  unsigned Line;
+  SmallVector<const CoverageSegment *, 4> Segments;
+  LineCoverageStats Stats;
+};
+
+/// Get a \c LineCoverageIterator range for the lines described by \p CD.
+static inline iterator_range<LineCoverageIterator>
+getLineCoverageStats(const coverage::CoverageData &CD) {
+  auto Begin = LineCoverageIterator(CD);
+  auto End = Begin.getEnd();
+  return make_range(Begin, End);
+}
+
+// Profile coverage map has the following layout:
+// [CoverageMapFileHeader]
+// [ArrayStart]
+//  [CovMapFunctionRecord]
+//  [CovMapFunctionRecord]
+//  ...
+// [ArrayEnd]
+// [Encoded Region Mapping Data]
+LLVM_PACKED_START
+template <class IntPtrT> struct CovMapFunctionRecordV1 {
+#define COVMAP_V1
+#define COVMAP_FUNC_RECORD(Type, LLVMType, Name, Init) Type Name;
+#include "llvm/ProfileData/InstrProfData.inc"
+#undef COVMAP_V1
+
+  // Return the structural hash associated with the function.
+  template <support::endianness Endian> uint64_t getFuncHash() const {
+    return support::endian::byte_swap<uint64_t, Endian>(FuncHash);
+  }
+
+  // Return the coverage map data size for the funciton.
+  template <support::endianness Endian> uint32_t getDataSize() const {
+    return support::endian::byte_swap<uint32_t, Endian>(DataSize);
+  }
+
+  // Return function lookup key. The value is consider opaque.
+  template <support::endianness Endian> IntPtrT getFuncNameRef() const {
+    return support::endian::byte_swap<IntPtrT, Endian>(NamePtr);
+  }
+
+  // Return the PGO name of the function */
+  template <support::endianness Endian>
+  Error getFuncName(InstrProfSymtab &ProfileNames, StringRef &FuncName) const {
+    IntPtrT NameRef = getFuncNameRef<Endian>();
+    uint32_t NameS = support::endian::byte_swap<uint32_t, Endian>(NameSize);
+    FuncName = ProfileNames.getFuncName(NameRef, NameS);
+    if (NameS && FuncName.empty())
+      return make_error<CoverageMapError>(coveragemap_error::malformed);
+    return Error::success();
+  }
+};
+
+struct CovMapFunctionRecord {
+#define COVMAP_FUNC_RECORD(Type, LLVMType, Name, Init) Type Name;
+#include "llvm/ProfileData/InstrProfData.inc"
+
+  // Return the structural hash associated with the function.
+  template <support::endianness Endian> uint64_t getFuncHash() const {
+    return support::endian::byte_swap<uint64_t, Endian>(FuncHash);
+  }
+
+  // Return the coverage map data size for the funciton.
+  template <support::endianness Endian> uint32_t getDataSize() const {
+    return support::endian::byte_swap<uint32_t, Endian>(DataSize);
+  }
+
+  // Return function lookup key. The value is consider opaque.
+  template <support::endianness Endian> uint64_t getFuncNameRef() const {
+    return support::endian::byte_swap<uint64_t, Endian>(NameRef);
+  }
+
+  // Return the PGO name of the function */
+  template <support::endianness Endian>
+  Error getFuncName(InstrProfSymtab &ProfileNames, StringRef &FuncName) const {
+    uint64_t NameRef = getFuncNameRef<Endian>();
+    FuncName = ProfileNames.getFuncName(NameRef);
+    return Error::success();
+  }
+};
+
+// Per module coverage mapping data header, i.e. CoverageMapFileHeader
+// documented above.
+struct CovMapHeader {
+#define COVMAP_HEADER(Type, LLVMType, Name, Init) Type Name;
+#include "llvm/ProfileData/InstrProfData.inc"
+  template <support::endianness Endian> uint32_t getNRecords() const {
+    return support::endian::byte_swap<uint32_t, Endian>(NRecords);
+  }
+
+  template <support::endianness Endian> uint32_t getFilenamesSize() const {
+    return support::endian::byte_swap<uint32_t, Endian>(FilenamesSize);
+  }
+
+  template <support::endianness Endian> uint32_t getCoverageSize() const {
+    return support::endian::byte_swap<uint32_t, Endian>(CoverageSize);
+  }
+
+  template <support::endianness Endian> uint32_t getVersion() const {
+    return support::endian::byte_swap<uint32_t, Endian>(Version);
+  }
+};
+
+LLVM_PACKED_END
+
+enum CovMapVersion {
+  Version1 = 0,
+  // Function's name reference from CovMapFuncRecord is changed from raw
+  // name string pointer to MD5 to support name section compression. Name
+  // section is also compressed.
+  Version2 = 1,
+  // A new interpretation of the columnEnd field is added in order to mark
+  // regions as gap areas.
+  Version3 = 2,
+  // The current version is Version3
+  CurrentVersion = INSTR_PROF_COVMAP_VERSION
+};
+
+template <int CovMapVersion, class IntPtrT> struct CovMapTraits {
+  using CovMapFuncRecordType = CovMapFunctionRecord;
+  using NameRefType = uint64_t;
+};
+
+template <class IntPtrT> struct CovMapTraits<CovMapVersion::Version1, IntPtrT> {
+  using CovMapFuncRecordType = CovMapFunctionRecordV1<IntPtrT>;
+  using NameRefType = IntPtrT;
+};
+
+} // end namespace coverage
+
+/// Provide DenseMapInfo for CounterExpression
+template<> struct DenseMapInfo<coverage::CounterExpression> {
+  static inline coverage::CounterExpression getEmptyKey() {
+    using namespace coverage;
+
+    return CounterExpression(CounterExpression::ExprKind::Subtract,
+                             Counter::getCounter(~0U),
+                             Counter::getCounter(~0U));
+  }
+
+  static inline coverage::CounterExpression getTombstoneKey() {
+    using namespace coverage;
+
+    return CounterExpression(CounterExpression::ExprKind::Add,
+                             Counter::getCounter(~0U),
+                             Counter::getCounter(~0U));
+  }
+
+  static unsigned getHashValue(const coverage::CounterExpression &V) {
+    return static_cast<unsigned>(
+        hash_combine(V.Kind, V.LHS.getKind(), V.LHS.getCounterID(),
+                     V.RHS.getKind(), V.RHS.getCounterID()));
+  }
+
+  static bool isEqual(const coverage::CounterExpression &LHS,
+                      const coverage::CounterExpression &RHS) {
+    return LHS.Kind == RHS.Kind && LHS.LHS == RHS.LHS && LHS.RHS == RHS.RHS;
+  }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPING_H