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      1 //===- CoverageMapping.h - Code coverage mapping support --------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // Code coverage mapping data is generated by clang and read by
     11 // llvm-cov to show code coverage statistics for a file.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPING_H
     16 #define LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPING_H
     17 
     18 #include "llvm/ADT/ArrayRef.h"
     19 #include "llvm/ADT/DenseMap.h"
     20 #include "llvm/ADT/DenseSet.h"
     21 #include "llvm/ADT/Hashing.h"
     22 #include "llvm/ADT/None.h"
     23 #include "llvm/ADT/StringRef.h"
     24 #include "llvm/ADT/StringSet.h"
     25 #include "llvm/ADT/iterator.h"
     26 #include "llvm/ADT/iterator_range.h"
     27 #include "llvm/ProfileData/InstrProf.h"
     28 #include "llvm/Support/Compiler.h"
     29 #include "llvm/Support/Debug.h"
     30 #include "llvm/Support/Endian.h"
     31 #include "llvm/Support/Error.h"
     32 #include "llvm/Support/raw_ostream.h"
     33 #include <cassert>
     34 #include <cstdint>
     35 #include <iterator>
     36 #include <memory>
     37 #include <string>
     38 #include <system_error>
     39 #include <tuple>
     40 #include <utility>
     41 #include <vector>
     42 
     43 namespace llvm {
     44 
     45 class IndexedInstrProfReader;
     46 
     47 namespace coverage {
     48 
     49 class CoverageMappingReader;
     50 struct CoverageMappingRecord;
     51 
     52 enum class coveragemap_error {
     53   success = 0,
     54   eof,
     55   no_data_found,
     56   unsupported_version,
     57   truncated,
     58   malformed
     59 };
     60 
     61 const std::error_category &coveragemap_category();
     62 
     63 inline std::error_code make_error_code(coveragemap_error E) {
     64   return std::error_code(static_cast<int>(E), coveragemap_category());
     65 }
     66 
     67 class CoverageMapError : public ErrorInfo<CoverageMapError> {
     68 public:
     69   CoverageMapError(coveragemap_error Err) : Err(Err) {
     70     assert(Err != coveragemap_error::success && "Not an error");
     71   }
     72 
     73   std::string message() const override;
     74 
     75   void log(raw_ostream &OS) const override { OS << message(); }
     76 
     77   std::error_code convertToErrorCode() const override {
     78     return make_error_code(Err);
     79   }
     80 
     81   coveragemap_error get() const { return Err; }
     82 
     83   static char ID;
     84 
     85 private:
     86   coveragemap_error Err;
     87 };
     88 
     89 /// A Counter is an abstract value that describes how to compute the
     90 /// execution count for a region of code using the collected profile count data.
     91 struct Counter {
     92   enum CounterKind { Zero, CounterValueReference, Expression };
     93   static const unsigned EncodingTagBits = 2;
     94   static const unsigned EncodingTagMask = 0x3;
     95   static const unsigned EncodingCounterTagAndExpansionRegionTagBits =
     96       EncodingTagBits + 1;
     97 
     98 private:
     99   CounterKind Kind = Zero;
    100   unsigned ID = 0;
    101 
    102   Counter(CounterKind Kind, unsigned ID) : Kind(Kind), ID(ID) {}
    103 
    104 public:
    105   Counter() = default;
    106 
    107   CounterKind getKind() const { return Kind; }
    108 
    109   bool isZero() const { return Kind == Zero; }
    110 
    111   bool isExpression() const { return Kind == Expression; }
    112 
    113   unsigned getCounterID() const { return ID; }
    114 
    115   unsigned getExpressionID() const { return ID; }
    116 
    117   friend bool operator==(const Counter &LHS, const Counter &RHS) {
    118     return LHS.Kind == RHS.Kind && LHS.ID == RHS.ID;
    119   }
    120 
    121   friend bool operator!=(const Counter &LHS, const Counter &RHS) {
    122     return !(LHS == RHS);
    123   }
    124 
    125   friend bool operator<(const Counter &LHS, const Counter &RHS) {
    126     return std::tie(LHS.Kind, LHS.ID) < std::tie(RHS.Kind, RHS.ID);
    127   }
    128 
    129   /// Return the counter that represents the number zero.
    130   static Counter getZero() { return Counter(); }
    131 
    132   /// Return the counter that corresponds to a specific profile counter.
    133   static Counter getCounter(unsigned CounterId) {
    134     return Counter(CounterValueReference, CounterId);
    135   }
    136 
    137   /// Return the counter that corresponds to a specific addition counter
    138   /// expression.
    139   static Counter getExpression(unsigned ExpressionId) {
    140     return Counter(Expression, ExpressionId);
    141   }
    142 };
    143 
    144 /// A Counter expression is a value that represents an arithmetic operation
    145 /// with two counters.
    146 struct CounterExpression {
    147   enum ExprKind { Subtract, Add };
    148   ExprKind Kind;
    149   Counter LHS, RHS;
    150 
    151   CounterExpression(ExprKind Kind, Counter LHS, Counter RHS)
    152       : Kind(Kind), LHS(LHS), RHS(RHS) {}
    153 };
    154 
    155 /// A Counter expression builder is used to construct the counter expressions.
    156 /// It avoids unnecessary duplication and simplifies algebraic expressions.
    157 class CounterExpressionBuilder {
    158   /// A list of all the counter expressions
    159   std::vector<CounterExpression> Expressions;
    160 
    161   /// A lookup table for the index of a given expression.
    162   DenseMap<CounterExpression, unsigned> ExpressionIndices;
    163 
    164   /// Return the counter which corresponds to the given expression.
    165   ///
    166   /// If the given expression is already stored in the builder, a counter
    167   /// that references that expression is returned. Otherwise, the given
    168   /// expression is added to the builder's collection of expressions.
    169   Counter get(const CounterExpression &E);
    170 
    171   /// Represents a term in a counter expression tree.
    172   struct Term {
    173     unsigned CounterID;
    174     int Factor;
    175 
    176     Term(unsigned CounterID, int Factor)
    177         : CounterID(CounterID), Factor(Factor) {}
    178   };
    179 
    180   /// Gather the terms of the expression tree for processing.
    181   ///
    182   /// This collects each addition and subtraction referenced by the counter into
    183   /// a sequence that can be sorted and combined to build a simplified counter
    184   /// expression.
    185   void extractTerms(Counter C, int Sign, SmallVectorImpl<Term> &Terms);
    186 
    187   /// Simplifies the given expression tree
    188   /// by getting rid of algebraically redundant operations.
    189   Counter simplify(Counter ExpressionTree);
    190 
    191 public:
    192   ArrayRef<CounterExpression> getExpressions() const { return Expressions; }
    193 
    194   /// Return a counter that represents the expression that adds LHS and RHS.
    195   Counter add(Counter LHS, Counter RHS);
    196 
    197   /// Return a counter that represents the expression that subtracts RHS from
    198   /// LHS.
    199   Counter subtract(Counter LHS, Counter RHS);
    200 };
    201 
    202 using LineColPair = std::pair<unsigned, unsigned>;
    203 
    204 /// A Counter mapping region associates a source range with a specific counter.
    205 struct CounterMappingRegion {
    206   enum RegionKind {
    207     /// A CodeRegion associates some code with a counter
    208     CodeRegion,
    209 
    210     /// An ExpansionRegion represents a file expansion region that associates
    211     /// a source range with the expansion of a virtual source file, such as
    212     /// for a macro instantiation or #include file.
    213     ExpansionRegion,
    214 
    215     /// A SkippedRegion represents a source range with code that was skipped
    216     /// by a preprocessor or similar means.
    217     SkippedRegion,
    218 
    219     /// A GapRegion is like a CodeRegion, but its count is only set as the
    220     /// line execution count when its the only region in the line.
    221     GapRegion
    222   };
    223 
    224   Counter Count;
    225   unsigned FileID, ExpandedFileID;
    226   unsigned LineStart, ColumnStart, LineEnd, ColumnEnd;
    227   RegionKind Kind;
    228 
    229   CounterMappingRegion(Counter Count, unsigned FileID, unsigned ExpandedFileID,
    230                        unsigned LineStart, unsigned ColumnStart,
    231                        unsigned LineEnd, unsigned ColumnEnd, RegionKind Kind)
    232       : Count(Count), FileID(FileID), ExpandedFileID(ExpandedFileID),
    233         LineStart(LineStart), ColumnStart(ColumnStart), LineEnd(LineEnd),
    234         ColumnEnd(ColumnEnd), Kind(Kind) {}
    235 
    236   static CounterMappingRegion
    237   makeRegion(Counter Count, unsigned FileID, unsigned LineStart,
    238              unsigned ColumnStart, unsigned LineEnd, unsigned ColumnEnd) {
    239     return CounterMappingRegion(Count, FileID, 0, LineStart, ColumnStart,
    240                                 LineEnd, ColumnEnd, CodeRegion);
    241   }
    242 
    243   static CounterMappingRegion
    244   makeExpansion(unsigned FileID, unsigned ExpandedFileID, unsigned LineStart,
    245                 unsigned ColumnStart, unsigned LineEnd, unsigned ColumnEnd) {
    246     return CounterMappingRegion(Counter(), FileID, ExpandedFileID, LineStart,
    247                                 ColumnStart, LineEnd, ColumnEnd,
    248                                 ExpansionRegion);
    249   }
    250 
    251   static CounterMappingRegion
    252   makeSkipped(unsigned FileID, unsigned LineStart, unsigned ColumnStart,
    253               unsigned LineEnd, unsigned ColumnEnd) {
    254     return CounterMappingRegion(Counter(), FileID, 0, LineStart, ColumnStart,
    255                                 LineEnd, ColumnEnd, SkippedRegion);
    256   }
    257 
    258   static CounterMappingRegion
    259   makeGapRegion(Counter Count, unsigned FileID, unsigned LineStart,
    260                 unsigned ColumnStart, unsigned LineEnd, unsigned ColumnEnd) {
    261     return CounterMappingRegion(Count, FileID, 0, LineStart, ColumnStart,
    262                                 LineEnd, (1U << 31) | ColumnEnd, GapRegion);
    263   }
    264 
    265   inline LineColPair startLoc() const {
    266     return LineColPair(LineStart, ColumnStart);
    267   }
    268 
    269   inline LineColPair endLoc() const { return LineColPair(LineEnd, ColumnEnd); }
    270 };
    271 
    272 /// Associates a source range with an execution count.
    273 struct CountedRegion : public CounterMappingRegion {
    274   uint64_t ExecutionCount;
    275 
    276   CountedRegion(const CounterMappingRegion &R, uint64_t ExecutionCount)
    277       : CounterMappingRegion(R), ExecutionCount(ExecutionCount) {}
    278 };
    279 
    280 /// A Counter mapping context is used to connect the counters, expressions
    281 /// and the obtained counter values.
    282 class CounterMappingContext {
    283   ArrayRef<CounterExpression> Expressions;
    284   ArrayRef<uint64_t> CounterValues;
    285 
    286 public:
    287   CounterMappingContext(ArrayRef<CounterExpression> Expressions,
    288                         ArrayRef<uint64_t> CounterValues = None)
    289       : Expressions(Expressions), CounterValues(CounterValues) {}
    290 
    291   void setCounts(ArrayRef<uint64_t> Counts) { CounterValues = Counts; }
    292 
    293   void dump(const Counter &C, raw_ostream &OS) const;
    294   void dump(const Counter &C) const { dump(C, dbgs()); }
    295 
    296   /// Return the number of times that a region of code associated with this
    297   /// counter was executed.
    298   Expected<int64_t> evaluate(const Counter &C) const;
    299 };
    300 
    301 /// Code coverage information for a single function.
    302 struct FunctionRecord {
    303   /// Raw function name.
    304   std::string Name;
    305   /// Associated files.
    306   std::vector<std::string> Filenames;
    307   /// Regions in the function along with their counts.
    308   std::vector<CountedRegion> CountedRegions;
    309   /// The number of times this function was executed.
    310   uint64_t ExecutionCount;
    311 
    312   FunctionRecord(StringRef Name, ArrayRef<StringRef> Filenames)
    313       : Name(Name), Filenames(Filenames.begin(), Filenames.end()) {}
    314 
    315   FunctionRecord(FunctionRecord &&FR) = default;
    316   FunctionRecord &operator=(FunctionRecord &&) = default;
    317 
    318   void pushRegion(CounterMappingRegion Region, uint64_t Count) {
    319     if (CountedRegions.empty())
    320       ExecutionCount = Count;
    321     CountedRegions.emplace_back(Region, Count);
    322   }
    323 };
    324 
    325 /// Iterator over Functions, optionally filtered to a single file.
    326 class FunctionRecordIterator
    327     : public iterator_facade_base<FunctionRecordIterator,
    328                                   std::forward_iterator_tag, FunctionRecord> {
    329   ArrayRef<FunctionRecord> Records;
    330   ArrayRef<FunctionRecord>::iterator Current;
    331   StringRef Filename;
    332 
    333   /// Skip records whose primary file is not \c Filename.
    334   void skipOtherFiles();
    335 
    336 public:
    337   FunctionRecordIterator(ArrayRef<FunctionRecord> Records_,
    338                          StringRef Filename = "")
    339       : Records(Records_), Current(Records.begin()), Filename(Filename) {
    340     skipOtherFiles();
    341   }
    342 
    343   FunctionRecordIterator() : Current(Records.begin()) {}
    344 
    345   bool operator==(const FunctionRecordIterator &RHS) const {
    346     return Current == RHS.Current && Filename == RHS.Filename;
    347   }
    348 
    349   const FunctionRecord &operator*() const { return *Current; }
    350 
    351   FunctionRecordIterator &operator++() {
    352     assert(Current != Records.end() && "incremented past end");
    353     ++Current;
    354     skipOtherFiles();
    355     return *this;
    356   }
    357 };
    358 
    359 /// Coverage information for a macro expansion or #included file.
    360 ///
    361 /// When covered code has pieces that can be expanded for more detail, such as a
    362 /// preprocessor macro use and its definition, these are represented as
    363 /// expansions whose coverage can be looked up independently.
    364 struct ExpansionRecord {
    365   /// The abstract file this expansion covers.
    366   unsigned FileID;
    367   /// The region that expands to this record.
    368   const CountedRegion &Region;
    369   /// Coverage for the expansion.
    370   const FunctionRecord &Function;
    371 
    372   ExpansionRecord(const CountedRegion &Region,
    373                   const FunctionRecord &Function)
    374       : FileID(Region.ExpandedFileID), Region(Region), Function(Function) {}
    375 };
    376 
    377 /// The execution count information starting at a point in a file.
    378 ///
    379 /// A sequence of CoverageSegments gives execution counts for a file in format
    380 /// that's simple to iterate through for processing.
    381 struct CoverageSegment {
    382   /// The line where this segment begins.
    383   unsigned Line;
    384   /// The column where this segment begins.
    385   unsigned Col;
    386   /// The execution count, or zero if no count was recorded.
    387   uint64_t Count;
    388   /// When false, the segment was uninstrumented or skipped.
    389   bool HasCount;
    390   /// Whether this enters a new region or returns to a previous count.
    391   bool IsRegionEntry;
    392   /// Whether this enters a gap region.
    393   bool IsGapRegion;
    394 
    395   CoverageSegment(unsigned Line, unsigned Col, bool IsRegionEntry)
    396       : Line(Line), Col(Col), Count(0), HasCount(false),
    397         IsRegionEntry(IsRegionEntry), IsGapRegion(false) {}
    398 
    399   CoverageSegment(unsigned Line, unsigned Col, uint64_t Count,
    400                   bool IsRegionEntry, bool IsGapRegion = false)
    401       : Line(Line), Col(Col), Count(Count), HasCount(true),
    402         IsRegionEntry(IsRegionEntry), IsGapRegion(IsGapRegion) {}
    403 
    404   friend bool operator==(const CoverageSegment &L, const CoverageSegment &R) {
    405     return std::tie(L.Line, L.Col, L.Count, L.HasCount, L.IsRegionEntry,
    406                     L.IsGapRegion) == std::tie(R.Line, R.Col, R.Count,
    407                                                R.HasCount, R.IsRegionEntry,
    408                                                R.IsGapRegion);
    409   }
    410 };
    411 
    412 /// An instantiation group contains a \c FunctionRecord list, such that each
    413 /// record corresponds to a distinct instantiation of the same function.
    414 ///
    415 /// Note that it's possible for a function to have more than one instantiation
    416 /// (consider C++ template specializations or static inline functions).
    417 class InstantiationGroup {
    418   friend class CoverageMapping;
    419 
    420   unsigned Line;
    421   unsigned Col;
    422   std::vector<const FunctionRecord *> Instantiations;
    423 
    424   InstantiationGroup(unsigned Line, unsigned Col,
    425                      std::vector<const FunctionRecord *> Instantiations)
    426       : Line(Line), Col(Col), Instantiations(std::move(Instantiations)) {}
    427 
    428 public:
    429   InstantiationGroup(const InstantiationGroup &) = delete;
    430   InstantiationGroup(InstantiationGroup &&) = default;
    431 
    432   /// Get the number of instantiations in this group.
    433   size_t size() const { return Instantiations.size(); }
    434 
    435   /// Get the line where the common function was defined.
    436   unsigned getLine() const { return Line; }
    437 
    438   /// Get the column where the common function was defined.
    439   unsigned getColumn() const { return Col; }
    440 
    441   /// Check if the instantiations in this group have a common mangled name.
    442   bool hasName() const {
    443     for (unsigned I = 1, E = Instantiations.size(); I < E; ++I)
    444       if (Instantiations[I]->Name != Instantiations[0]->Name)
    445         return false;
    446     return true;
    447   }
    448 
    449   /// Get the common mangled name for instantiations in this group.
    450   StringRef getName() const {
    451     assert(hasName() && "Instantiations don't have a shared name");
    452     return Instantiations[0]->Name;
    453   }
    454 
    455   /// Get the total execution count of all instantiations in this group.
    456   uint64_t getTotalExecutionCount() const {
    457     uint64_t Count = 0;
    458     for (const FunctionRecord *F : Instantiations)
    459       Count += F->ExecutionCount;
    460     return Count;
    461   }
    462 
    463   /// Get the instantiations in this group.
    464   ArrayRef<const FunctionRecord *> getInstantiations() const {
    465     return Instantiations;
    466   }
    467 };
    468 
    469 /// Coverage information to be processed or displayed.
    470 ///
    471 /// This represents the coverage of an entire file, expansion, or function. It
    472 /// provides a sequence of CoverageSegments to iterate through, as well as the
    473 /// list of expansions that can be further processed.
    474 class CoverageData {
    475   friend class CoverageMapping;
    476 
    477   std::string Filename;
    478   std::vector<CoverageSegment> Segments;
    479   std::vector<ExpansionRecord> Expansions;
    480 
    481 public:
    482   CoverageData() = default;
    483 
    484   CoverageData(StringRef Filename) : Filename(Filename) {}
    485 
    486   /// Get the name of the file this data covers.
    487   StringRef getFilename() const { return Filename; }
    488 
    489   /// Get an iterator over the coverage segments for this object. The segments
    490   /// are guaranteed to be uniqued and sorted by location.
    491   std::vector<CoverageSegment>::const_iterator begin() const {
    492     return Segments.begin();
    493   }
    494 
    495   std::vector<CoverageSegment>::const_iterator end() const {
    496     return Segments.end();
    497   }
    498 
    499   bool empty() const { return Segments.empty(); }
    500 
    501   /// Expansions that can be further processed.
    502   ArrayRef<ExpansionRecord> getExpansions() const { return Expansions; }
    503 };
    504 
    505 /// The mapping of profile information to coverage data.
    506 ///
    507 /// This is the main interface to get coverage information, using a profile to
    508 /// fill out execution counts.
    509 class CoverageMapping {
    510   DenseMap<size_t, DenseSet<size_t>> RecordProvenance;
    511   std::vector<FunctionRecord> Functions;
    512   std::vector<std::pair<std::string, uint64_t>> FuncHashMismatches;
    513   std::vector<std::pair<std::string, uint64_t>> FuncCounterMismatches;
    514 
    515   CoverageMapping() = default;
    516 
    517   /// Add a function record corresponding to \p Record.
    518   Error loadFunctionRecord(const CoverageMappingRecord &Record,
    519                            IndexedInstrProfReader &ProfileReader);
    520 
    521 public:
    522   CoverageMapping(const CoverageMapping &) = delete;
    523   CoverageMapping &operator=(const CoverageMapping &) = delete;
    524 
    525   /// Load the coverage mapping using the given readers.
    526   static Expected<std::unique_ptr<CoverageMapping>>
    527   load(ArrayRef<std::unique_ptr<CoverageMappingReader>> CoverageReaders,
    528        IndexedInstrProfReader &ProfileReader);
    529 
    530   /// Load the coverage mapping from the given object files and profile. If
    531   /// \p Arches is non-empty, it must specify an architecture for each object.
    532   static Expected<std::unique_ptr<CoverageMapping>>
    533   load(ArrayRef<StringRef> ObjectFilenames, StringRef ProfileFilename,
    534        ArrayRef<StringRef> Arches = None);
    535 
    536   /// The number of functions that couldn't have their profiles mapped.
    537   ///
    538   /// This is a count of functions whose profile is out of date or otherwise
    539   /// can't be associated with any coverage information.
    540   unsigned getMismatchedCount() const {
    541     return FuncHashMismatches.size() + FuncCounterMismatches.size();
    542   }
    543 
    544   /// A hash mismatch occurs when a profile record for a symbol does not have
    545   /// the same hash as a coverage mapping record for the same symbol. This
    546   /// returns a list of hash mismatches, where each mismatch is a pair of the
    547   /// symbol name and its coverage mapping hash.
    548   ArrayRef<std::pair<std::string, uint64_t>> getHashMismatches() const {
    549     return FuncHashMismatches;
    550   }
    551 
    552   /// A counter mismatch occurs when there is an error when evaluating the
    553   /// counter expressions in a coverage mapping record. This returns a list of
    554   /// counter mismatches, where each mismatch is a pair of the symbol name and
    555   /// the number of valid evaluated counter expressions.
    556   ArrayRef<std::pair<std::string, uint64_t>> getCounterMismatches() const {
    557     return FuncCounterMismatches;
    558   }
    559 
    560   /// Returns a lexicographically sorted, unique list of files that are
    561   /// covered.
    562   std::vector<StringRef> getUniqueSourceFiles() const;
    563 
    564   /// Get the coverage for a particular file.
    565   ///
    566   /// The given filename must be the name as recorded in the coverage
    567   /// information. That is, only names returned from getUniqueSourceFiles will
    568   /// yield a result.
    569   CoverageData getCoverageForFile(StringRef Filename) const;
    570 
    571   /// Get the coverage for a particular function.
    572   CoverageData getCoverageForFunction(const FunctionRecord &Function) const;
    573 
    574   /// Get the coverage for an expansion within a coverage set.
    575   CoverageData getCoverageForExpansion(const ExpansionRecord &Expansion) const;
    576 
    577   /// Gets all of the functions covered by this profile.
    578   iterator_range<FunctionRecordIterator> getCoveredFunctions() const {
    579     return make_range(FunctionRecordIterator(Functions),
    580                       FunctionRecordIterator());
    581   }
    582 
    583   /// Gets all of the functions in a particular file.
    584   iterator_range<FunctionRecordIterator>
    585   getCoveredFunctions(StringRef Filename) const {
    586     return make_range(FunctionRecordIterator(Functions, Filename),
    587                       FunctionRecordIterator());
    588   }
    589 
    590   /// Get the list of function instantiation groups in a particular file.
    591   ///
    592   /// Every instantiation group in a program is attributed to exactly one file:
    593   /// the file in which the definition for the common function begins.
    594   std::vector<InstantiationGroup>
    595   getInstantiationGroups(StringRef Filename) const;
    596 };
    597 
    598 /// Coverage statistics for a single line.
    599 class LineCoverageStats {
    600   uint64_t ExecutionCount;
    601   bool HasMultipleRegions;
    602   bool Mapped;
    603   unsigned Line;
    604   ArrayRef<const CoverageSegment *> LineSegments;
    605   const CoverageSegment *WrappedSegment;
    606 
    607   friend class LineCoverageIterator;
    608   LineCoverageStats() = default;
    609 
    610 public:
    611   LineCoverageStats(ArrayRef<const CoverageSegment *> LineSegments,
    612                     const CoverageSegment *WrappedSegment, unsigned Line);
    613 
    614   uint64_t getExecutionCount() const { return ExecutionCount; }
    615 
    616   bool hasMultipleRegions() const { return HasMultipleRegions; }
    617 
    618   bool isMapped() const { return Mapped; }
    619 
    620   unsigned getLine() const { return Line; }
    621 
    622   ArrayRef<const CoverageSegment *> getLineSegments() const {
    623     return LineSegments;
    624   }
    625 
    626   const CoverageSegment *getWrappedSegment() const { return WrappedSegment; }
    627 };
    628 
    629 /// An iterator over the \c LineCoverageStats objects for lines described by
    630 /// a \c CoverageData instance.
    631 class LineCoverageIterator
    632     : public iterator_facade_base<
    633           LineCoverageIterator, std::forward_iterator_tag, LineCoverageStats> {
    634 public:
    635   LineCoverageIterator(const CoverageData &CD)
    636       : LineCoverageIterator(CD, CD.begin()->Line) {}
    637 
    638   LineCoverageIterator(const CoverageData &CD, unsigned Line)
    639       : CD(CD), WrappedSegment(nullptr), Next(CD.begin()), Ended(false),
    640         Line(Line), Segments(), Stats() {
    641     this->operator++();
    642   }
    643 
    644   bool operator==(const LineCoverageIterator &R) const {
    645     return &CD == &R.CD && Next == R.Next && Ended == R.Ended;
    646   }
    647 
    648   const LineCoverageStats &operator*() const { return Stats; }
    649 
    650   LineCoverageStats &operator*() { return Stats; }
    651 
    652   LineCoverageIterator &operator++();
    653 
    654   LineCoverageIterator getEnd() const {
    655     auto EndIt = *this;
    656     EndIt.Next = CD.end();
    657     EndIt.Ended = true;
    658     return EndIt;
    659   }
    660 
    661 private:
    662   const CoverageData &CD;
    663   const CoverageSegment *WrappedSegment;
    664   std::vector<CoverageSegment>::const_iterator Next;
    665   bool Ended;
    666   unsigned Line;
    667   SmallVector<const CoverageSegment *, 4> Segments;
    668   LineCoverageStats Stats;
    669 };
    670 
    671 /// Get a \c LineCoverageIterator range for the lines described by \p CD.
    672 static inline iterator_range<LineCoverageIterator>
    673 getLineCoverageStats(const coverage::CoverageData &CD) {
    674   auto Begin = LineCoverageIterator(CD);
    675   auto End = Begin.getEnd();
    676   return make_range(Begin, End);
    677 }
    678 
    679 // Profile coverage map has the following layout:
    680 // [CoverageMapFileHeader]
    681 // [ArrayStart]
    682 //  [CovMapFunctionRecord]
    683 //  [CovMapFunctionRecord]
    684 //  ...
    685 // [ArrayEnd]
    686 // [Encoded Region Mapping Data]
    687 LLVM_PACKED_START
    688 template <class IntPtrT> struct CovMapFunctionRecordV1 {
    689 #define COVMAP_V1
    690 #define COVMAP_FUNC_RECORD(Type, LLVMType, Name, Init) Type Name;
    691 #include "llvm/ProfileData/InstrProfData.inc"
    692 #undef COVMAP_V1
    693 
    694   // Return the structural hash associated with the function.
    695   template <support::endianness Endian> uint64_t getFuncHash() const {
    696     return support::endian::byte_swap<uint64_t, Endian>(FuncHash);
    697   }
    698 
    699   // Return the coverage map data size for the funciton.
    700   template <support::endianness Endian> uint32_t getDataSize() const {
    701     return support::endian::byte_swap<uint32_t, Endian>(DataSize);
    702   }
    703 
    704   // Return function lookup key. The value is consider opaque.
    705   template <support::endianness Endian> IntPtrT getFuncNameRef() const {
    706     return support::endian::byte_swap<IntPtrT, Endian>(NamePtr);
    707   }
    708 
    709   // Return the PGO name of the function */
    710   template <support::endianness Endian>
    711   Error getFuncName(InstrProfSymtab &ProfileNames, StringRef &FuncName) const {
    712     IntPtrT NameRef = getFuncNameRef<Endian>();
    713     uint32_t NameS = support::endian::byte_swap<uint32_t, Endian>(NameSize);
    714     FuncName = ProfileNames.getFuncName(NameRef, NameS);
    715     if (NameS && FuncName.empty())
    716       return make_error<CoverageMapError>(coveragemap_error::malformed);
    717     return Error::success();
    718   }
    719 };
    720 
    721 struct CovMapFunctionRecord {
    722 #define COVMAP_FUNC_RECORD(Type, LLVMType, Name, Init) Type Name;
    723 #include "llvm/ProfileData/InstrProfData.inc"
    724 
    725   // Return the structural hash associated with the function.
    726   template <support::endianness Endian> uint64_t getFuncHash() const {
    727     return support::endian::byte_swap<uint64_t, Endian>(FuncHash);
    728   }
    729 
    730   // Return the coverage map data size for the funciton.
    731   template <support::endianness Endian> uint32_t getDataSize() const {
    732     return support::endian::byte_swap<uint32_t, Endian>(DataSize);
    733   }
    734 
    735   // Return function lookup key. The value is consider opaque.
    736   template <support::endianness Endian> uint64_t getFuncNameRef() const {
    737     return support::endian::byte_swap<uint64_t, Endian>(NameRef);
    738   }
    739 
    740   // Return the PGO name of the function */
    741   template <support::endianness Endian>
    742   Error getFuncName(InstrProfSymtab &ProfileNames, StringRef &FuncName) const {
    743     uint64_t NameRef = getFuncNameRef<Endian>();
    744     FuncName = ProfileNames.getFuncName(NameRef);
    745     return Error::success();
    746   }
    747 };
    748 
    749 // Per module coverage mapping data header, i.e. CoverageMapFileHeader
    750 // documented above.
    751 struct CovMapHeader {
    752 #define COVMAP_HEADER(Type, LLVMType, Name, Init) Type Name;
    753 #include "llvm/ProfileData/InstrProfData.inc"
    754   template <support::endianness Endian> uint32_t getNRecords() const {
    755     return support::endian::byte_swap<uint32_t, Endian>(NRecords);
    756   }
    757 
    758   template <support::endianness Endian> uint32_t getFilenamesSize() const {
    759     return support::endian::byte_swap<uint32_t, Endian>(FilenamesSize);
    760   }
    761 
    762   template <support::endianness Endian> uint32_t getCoverageSize() const {
    763     return support::endian::byte_swap<uint32_t, Endian>(CoverageSize);
    764   }
    765 
    766   template <support::endianness Endian> uint32_t getVersion() const {
    767     return support::endian::byte_swap<uint32_t, Endian>(Version);
    768   }
    769 };
    770 
    771 LLVM_PACKED_END
    772 
    773 enum CovMapVersion {
    774   Version1 = 0,
    775   // Function's name reference from CovMapFuncRecord is changed from raw
    776   // name string pointer to MD5 to support name section compression. Name
    777   // section is also compressed.
    778   Version2 = 1,
    779   // A new interpretation of the columnEnd field is added in order to mark
    780   // regions as gap areas.
    781   Version3 = 2,
    782   // The current version is Version3
    783   CurrentVersion = INSTR_PROF_COVMAP_VERSION
    784 };
    785 
    786 template <int CovMapVersion, class IntPtrT> struct CovMapTraits {
    787   using CovMapFuncRecordType = CovMapFunctionRecord;
    788   using NameRefType = uint64_t;
    789 };
    790 
    791 template <class IntPtrT> struct CovMapTraits<CovMapVersion::Version1, IntPtrT> {
    792   using CovMapFuncRecordType = CovMapFunctionRecordV1<IntPtrT>;
    793   using NameRefType = IntPtrT;
    794 };
    795 
    796 } // end namespace coverage
    797 
    798 /// Provide DenseMapInfo for CounterExpression
    799 template<> struct DenseMapInfo<coverage::CounterExpression> {
    800   static inline coverage::CounterExpression getEmptyKey() {
    801     using namespace coverage;
    802 
    803     return CounterExpression(CounterExpression::ExprKind::Subtract,
    804                              Counter::getCounter(~0U),
    805                              Counter::getCounter(~0U));
    806   }
    807 
    808   static inline coverage::CounterExpression getTombstoneKey() {
    809     using namespace coverage;
    810 
    811     return CounterExpression(CounterExpression::ExprKind::Add,
    812                              Counter::getCounter(~0U),
    813                              Counter::getCounter(~0U));
    814   }
    815 
    816   static unsigned getHashValue(const coverage::CounterExpression &V) {
    817     return static_cast<unsigned>(
    818         hash_combine(V.Kind, V.LHS.getKind(), V.LHS.getCounterID(),
    819                      V.RHS.getKind(), V.RHS.getCounterID()));
    820   }
    821 
    822   static bool isEqual(const coverage::CounterExpression &LHS,
    823                       const coverage::CounterExpression &RHS) {
    824     return LHS.Kind == RHS.Kind && LHS.LHS == RHS.LHS && LHS.RHS == RHS.RHS;
    825   }
    826 };
    827 
    828 } // end namespace llvm
    829 
    830 #endif // LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPING_H
    831