lib/ProfileData/Coverage/CoverageMapping.cpp

   1 //===- CoverageMapping.cpp - Code coverage mapping support ----------------===//
   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 // This file contains support for clang's and llvm's instrumentation based
  11 // code coverage.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/ProfileData/Coverage/CoverageMapping.h"
  16 #include "llvm/ADT/ArrayRef.h"
  17 #include "llvm/ADT/DenseMap.h"
  18 #include "llvm/ADT/None.h"
  19 #include "llvm/ADT/Optional.h"
  20 #include "llvm/ADT/SmallBitVector.h"
  21 #include "llvm/ADT/SmallVector.h"
  22 #include "llvm/ADT/StringRef.h"
  23 #include "llvm/ProfileData/Coverage/CoverageMappingReader.h"
  24 #include "llvm/ProfileData/InstrProfReader.h"
  25 #include "llvm/Support/Debug.h"
  26 #include "llvm/Support/Errc.h"
  27 #include "llvm/Support/Error.h"
  28 #include "llvm/Support/ErrorHandling.h"
  29 #include "llvm/Support/ManagedStatic.h"
  30 #include "llvm/Support/MemoryBuffer.h"
  31 #include "llvm/Support/raw_ostream.h"
  32 #include <algorithm>
  33 #include <cassert>
  34 #include <cstdint>
  35 #include <iterator>
  36 #include <map>
  37 #include <memory>
  38 #include <string>
  39 #include <system_error>
  40 #include <utility>
  41 #include <vector>
  42
  43 using namespace llvm;
  44 using namespace coverage;
  45
  46 #define DEBUG_TYPE "coverage-mapping"
  47
  48 Counter CounterExpressionBuilder::get(const CounterExpression &E) {
  49   auto It = ExpressionIndices.find(E);
  50   if (It != ExpressionIndices.end())
  51     return Counter::getExpression(It->second);
  52   unsigned I = Expressions.size();
  53   Expressions.push_back(E);
  54   ExpressionIndices[E] = I;
  55   return Counter::getExpression(I);
  56 }
  57
  58 void CounterExpressionBuilder::extractTerms(Counter C, int Factor,
  59                                             SmallVectorImpl<Term> &Terms) {
  60   switch (C.getKind()) {
  61   case Counter::Zero:
  62     break;
  63   case Counter::CounterValueReference:
  64     Terms.emplace_back(C.getCounterID(), Factor);
  65     break;
  66   case Counter::Expression:
  67     const auto &E = Expressions[C.getExpressionID()];
  68     extractTerms(E.LHS, Factor, Terms);
  69     extractTerms(
  70         E.RHS, E.Kind == CounterExpression::Subtract ? -Factor : Factor, Terms);
  71     break;
  72   }
  73 }
  74
  75 Counter CounterExpressionBuilder::simplify(Counter ExpressionTree) {
  76   // Gather constant terms.
  77   SmallVector<Term, 32> Terms;
  78   extractTerms(ExpressionTree, +1, Terms);
  79
  80   // If there are no terms, this is just a zero. The algorithm below assumes at
  81   // least one term.
  82   if (Terms.size() == 0)
  83     return Counter::getZero();
  84
  85   // Group the terms by counter ID.
  86   llvm::sort(Terms.begin(), Terms.end(), [](const Term &LHS, const Term &RHS) {
  87     return LHS.CounterID < RHS.CounterID;
  88   });
  89
  90   // Combine terms by counter ID to eliminate counters that sum to zero.
  91   auto Prev = Terms.begin();
  92   for (auto I = Prev + 1, E = Terms.end(); I != E; ++I) {
  93     if (I->CounterID == Prev->CounterID) {
  94       Prev->Factor += I->Factor;
  95       continue;
  96     }
  97     ++Prev;
  98     *Prev = *I;
  99   }
 100   Terms.erase(++Prev, Terms.end());
 101
 102   Counter C;
 103   // Create additions. We do this before subtractions to avoid constructs like
 104   // ((0 - X) + Y), as opposed to (Y - X).
 105   for (auto T : Terms) {
 106     if (T.Factor <= 0)
 107       continue;
 108     for (int I = 0; I < T.Factor; ++I)
 109       if (C.isZero())
 110         C = Counter::getCounter(T.CounterID);
 111       else
 112         C = get(CounterExpression(CounterExpression::Add, C,
 113                                   Counter::getCounter(T.CounterID)));
 114   }
 115
 116   // Create subtractions.
 117   for (auto T : Terms) {
 118     if (T.Factor >= 0)
 119       continue;
 120     for (int I = 0; I < -T.Factor; ++I)
 121       C = get(CounterExpression(CounterExpression::Subtract, C,
 122                                 Counter::getCounter(T.CounterID)));
 123   }
 124   return C;
 125 }
 126
 127 Counter CounterExpressionBuilder::add(Counter LHS, Counter RHS) {
 128   return simplify(get(CounterExpression(CounterExpression::Add, LHS, RHS)));
 129 }
 130
 131 Counter CounterExpressionBuilder::subtract(Counter LHS, Counter RHS) {
 132   return simplify(
 133       get(CounterExpression(CounterExpression::Subtract, LHS, RHS)));
 134 }
 135
 136 void CounterMappingContext::dump(const Counter &C, raw_ostream &OS) const {
 137   switch (C.getKind()) {
 138   case Counter::Zero:
 139     OS << '0';
 140     return;
 141   case Counter::CounterValueReference:
 142     OS << '#' << C.getCounterID();
 143     break;
 144   case Counter::Expression: {
 145     if (C.getExpressionID() >= Expressions.size())
 146       return;
 147     const auto &E = Expressions[C.getExpressionID()];
 148     OS << '(';
 149     dump(E.LHS, OS);
 150     OS << (E.Kind == CounterExpression::Subtract ? " - " : " + ");
 151     dump(E.RHS, OS);
 152     OS << ')';
 153     break;
 154   }
 155   }
 156   if (CounterValues.empty())
 157     return;
 158   Expected<int64_t> Value = evaluate(C);
 159   if (auto E = Value.takeError()) {
 160     consumeError(std::move(E));
 161     return;
 162   }
 163   OS << '[' << *Value << ']';
 164 }
 165
 166 Expected<int64_t> CounterMappingContext::evaluate(const Counter &C) const {
 167   switch (C.getKind()) {
 168   case Counter::Zero:
 169     return 0;
 170   case Counter::CounterValueReference:
 171     if (C.getCounterID() >= CounterValues.size())
 172       return errorCodeToError(errc::argument_out_of_domain);
 173     return CounterValues[C.getCounterID()];
 174   case Counter::Expression: {
 175     if (C.getExpressionID() >= Expressions.size())
 176       return errorCodeToError(errc::argument_out_of_domain);
 177     const auto &E = Expressions[C.getExpressionID()];
 178     Expected<int64_t> LHS = evaluate(E.LHS);
 179     if (!LHS)
 180       return LHS;
 181     Expected<int64_t> RHS = evaluate(E.RHS);
 182     if (!RHS)
 183       return RHS;
 184     return E.Kind == CounterExpression::Subtract ? *LHS - *RHS : *LHS + *RHS;
 185   }
 186   }
 187   llvm_unreachable("Unhandled CounterKind");
 188 }
 189
 190 void FunctionRecordIterator::skipOtherFiles() {
 191   while (Current != Records.end() && !Filename.empty() &&
 192          Filename != Current->Filenames[0])
 193     ++Current;
 194   if (Current == Records.end())
 195     *this = FunctionRecordIterator();
 196 }
 197
 198 Error CoverageMapping::loadFunctionRecord(
 199     const CoverageMappingRecord &Record,
 200     IndexedInstrProfReader &ProfileReader) {
 201   StringRef OrigFuncName = Record.FunctionName;
 202   if (OrigFuncName.empty())
 203     return make_error<CoverageMapError>(coveragemap_error::malformed);
 204
 205   if (Record.Filenames.empty())
 206     OrigFuncName = getFuncNameWithoutPrefix(OrigFuncName);
 207   else
 208     OrigFuncName = getFuncNameWithoutPrefix(OrigFuncName, Record.Filenames[0]);
 209
 210   CounterMappingContext Ctx(Record.Expressions);
 211
 212   std::vector<uint64_t> Counts;
 213   if (Error E = ProfileReader.getFunctionCounts(Record.FunctionName,
 214                                                 Record.FunctionHash, Counts)) {
 215     instrprof_error IPE = InstrProfError::take(std::move(E));
 216     if (IPE == instrprof_error::hash_mismatch) {
 217       FuncHashMismatches.emplace_back(Record.FunctionName, Record.FunctionHash);
 218       return Error::success();
 219     } else if (IPE != instrprof_error::unknown_function)
 220       return make_error<InstrProfError>(IPE);
 221     Counts.assign(Record.MappingRegions.size(), 0);
 222   }
 223   Ctx.setCounts(Counts);
 224
 225   assert(!Record.MappingRegions.empty() && "Function has no regions");
 226
 227   // This coverage record is a zero region for a function that's unused in
 228   // some TU, but used in a different TU. Ignore it. The coverage maps from the
 229   // the other TU will either be loaded (providing full region counts) or they
 230   // won't (in which case we don't unintuitively report functions as uncovered
 231   // when they have non-zero counts in the profile).
 232   if (Record.MappingRegions.size() == 1 &&
 233       Record.MappingRegions[0].Count.isZero() && Counts[0] > 0)
 234     return Error::success();
 235
 236   FunctionRecord Function(OrigFuncName, Record.Filenames);
 237   for (const auto &Region : Record.MappingRegions) {
 238     Expected<int64_t> ExecutionCount = Ctx.evaluate(Region.Count);
 239     if (auto E = ExecutionCount.takeError()) {
 240       consumeError(std::move(E));
 241       return Error::success();
 242     }
 243     Function.pushRegion(Region, *ExecutionCount);
 244   }
 245
 246   // Don't create records for (filenames, function) pairs we've already seen.
 247   auto FilenamesHash = hash_combine_range(Record.Filenames.begin(),
 248                                           Record.Filenames.end());
 249   if (!RecordProvenance[FilenamesHash].insert(hash_value(OrigFuncName)).second)
 250     return Error::success();
 251
 252   Functions.push_back(std::move(Function));
 253   return Error::success();
 254 }
 255
 256 Expected<std::unique_ptr<CoverageMapping>> CoverageMapping::load(
 257     ArrayRef<std::unique_ptr<CoverageMappingReader>> CoverageReaders,
 258     IndexedInstrProfReader &ProfileReader) {
 259   auto Coverage = std::unique_ptr<CoverageMapping>(new CoverageMapping());
 260
 261   for (const auto &CoverageReader : CoverageReaders) {
 262     for (auto RecordOrErr : *CoverageReader) {
 263       if (Error E = RecordOrErr.takeError())
 264         return std::move(E);
 265       const auto &Record = *RecordOrErr;
 266       if (Error E = Coverage->loadFunctionRecord(Record, ProfileReader))
 267         return std::move(E);
 268     }
 269   }
 270
 271   return std::move(Coverage);
 272 }
 273
 274 Expected<std::unique_ptr<CoverageMapping>>
 275 CoverageMapping::load(ArrayRef<StringRef> ObjectFilenames,
 276                       StringRef ProfileFilename, ArrayRef<StringRef> Arches) {
 277   auto ProfileReaderOrErr = IndexedInstrProfReader::create(ProfileFilename);
 278   if (Error E = ProfileReaderOrErr.takeError())
 279     return std::move(E);
 280   auto ProfileReader = std::move(ProfileReaderOrErr.get());
 281
 282   SmallVector<std::unique_ptr<CoverageMappingReader>, 4> Readers;
 283   SmallVector<std::unique_ptr<MemoryBuffer>, 4> Buffers;
 284   for (const auto &File : llvm::enumerate(ObjectFilenames)) {
 285     auto CovMappingBufOrErr = MemoryBuffer::getFileOrSTDIN(File.value());
 286     if (std::error_code EC = CovMappingBufOrErr.getError())
 287       return errorCodeToError(EC);
 288     StringRef Arch = Arches.empty() ? StringRef() : Arches[File.index()];
 289     auto CoverageReaderOrErr =
 290         BinaryCoverageReader::create(CovMappingBufOrErr.get(), Arch);
 291     if (Error E = CoverageReaderOrErr.takeError())
 292       return std::move(E);
 293     Readers.push_back(std::move(CoverageReaderOrErr.get()));
 294     Buffers.push_back(std::move(CovMappingBufOrErr.get()));
 295   }
 296   return load(Readers, *ProfileReader);
 297 }
 298
 299 namespace {
 300
 301 /// Distributes functions into instantiation sets.
 302 ///
 303 /// An instantiation set is a collection of functions that have the same source
 304 /// code, ie, template functions specializations.
 305 class FunctionInstantiationSetCollector {
 306   using MapT = std::map<LineColPair, std::vector<const FunctionRecord *>>;
 307   MapT InstantiatedFunctions;
 308
 309 public:
 310   void insert(const FunctionRecord &Function, unsigned FileID) {
 311     auto I = Function.CountedRegions.begin(), E = Function.CountedRegions.end();
 312     while (I != E && I->FileID != FileID)
 313       ++I;
 314     assert(I != E && "function does not cover the given file");
 315     auto &Functions = InstantiatedFunctions[I->startLoc()];
 316     Functions.push_back(&Function);
 317   }
 318
 319   MapT::iterator begin() { return InstantiatedFunctions.begin(); }
 320   MapT::iterator end() { return InstantiatedFunctions.end(); }
 321 };
 322
 323 class SegmentBuilder {
 324   std::vector<CoverageSegment> &Segments;
 325   SmallVector<const CountedRegion *, 8> ActiveRegions;
 326
 327   SegmentBuilder(std::vector<CoverageSegment> &Segments) : Segments(Segments) {}
 328
 329   /// Emit a segment with the count from \p Region starting at \p StartLoc.
 330   //
 331   /// \p IsRegionEntry: The segment is at the start of a new non-gap region.
 332   /// \p EmitSkippedRegion: The segment must be emitted as a skipped region.
 333   void startSegment(const CountedRegion &Region, LineColPair StartLoc,
 334                     bool IsRegionEntry, bool EmitSkippedRegion = false) {
 335     bool HasCount = !EmitSkippedRegion &&
 336                     (Region.Kind != CounterMappingRegion::SkippedRegion);
 337
 338     // If the new segment wouldn't affect coverage rendering, skip it.
 339     if (!Segments.empty() && !IsRegionEntry && !EmitSkippedRegion) {
 340       const auto &Last = Segments.back();
 341       if (Last.HasCount == HasCount && Last.Count == Region.ExecutionCount &&
 342           !Last.IsRegionEntry)
 343         return;
 344     }
 345
 346     if (HasCount)
 347       Segments.emplace_back(StartLoc.first, StartLoc.second,
 348                             Region.ExecutionCount, IsRegionEntry,
 349                             Region.Kind == CounterMappingRegion::GapRegion);
 350     else
 351       Segments.emplace_back(StartLoc.first, StartLoc.second, IsRegionEntry);
 352
 353     LLVM_DEBUG({
 354       const auto &Last = Segments.back();
 355       dbgs() << "Segment at " << Last.Line << ":" << Last.Col
 356              << " (count = " << Last.Count << ")"
 357              << (Last.IsRegionEntry ? ", RegionEntry" : "")
 358              << (!Last.HasCount ? ", Skipped" : "")
 359              << (Last.IsGapRegion ? ", Gap" : "") << "\n";
 360     });
 361   }
 362
 363   /// Emit segments for active regions which end before \p Loc.
 364   ///
 365   /// \p Loc: The start location of the next region. If None, all active
 366   /// regions are completed.
 367   /// \p FirstCompletedRegion: Index of the first completed region.
 368   void completeRegionsUntil(Optional<LineColPair> Loc,
 369                             unsigned FirstCompletedRegion) {
 370     // Sort the completed regions by end location. This makes it simple to
 371     // emit closing segments in sorted order.
 372     auto CompletedRegionsIt = ActiveRegions.begin() + FirstCompletedRegion;
 373     std::stable_sort(CompletedRegionsIt, ActiveRegions.end(),
 374                       [](const CountedRegion *L, const CountedRegion *R) {
 375                         return L->endLoc() < R->endLoc();
 376                       });
 377
 378     // Emit segments for all completed regions.
 379     for (unsigned I = FirstCompletedRegion + 1, E = ActiveRegions.size(); I < E;
 380          ++I) {
 381       const auto *CompletedRegion = ActiveRegions[I];
 382       assert((!Loc || CompletedRegion->endLoc() <= *Loc) &&
 383              "Completed region ends after start of new region");
 384
 385       const auto *PrevCompletedRegion = ActiveRegions[I - 1];
 386       auto CompletedSegmentLoc = PrevCompletedRegion->endLoc();
 387
 388       // Don't emit any more segments if they start where the new region begins.
 389       if (Loc && CompletedSegmentLoc == *Loc)
 390         break;
 391
 392       // Don't emit a segment if the next completed region ends at the same
 393       // location as this one.
 394       if (CompletedSegmentLoc == CompletedRegion->endLoc())
 395         continue;
 396
 397       // Use the count from the last completed region which ends at this loc.
 398       for (unsigned J = I + 1; J < E; ++J)
 399         if (CompletedRegion->endLoc() == ActiveRegions[J]->endLoc())
 400           CompletedRegion = ActiveRegions[J];
 401
 402       startSegment(*CompletedRegion, CompletedSegmentLoc, false);
 403     }
 404
 405     auto Last = ActiveRegions.back();
 406     if (FirstCompletedRegion && Last->endLoc() != *Loc) {
 407       // If there's a gap after the end of the last completed region and the
 408       // start of the new region, use the last active region to fill the gap.
 409       startSegment(*ActiveRegions[FirstCompletedRegion - 1], Last->endLoc(),
 410                    false);
 411     } else if (!FirstCompletedRegion && (!Loc || *Loc != Last->endLoc())) {
 412       // Emit a skipped segment if there are no more active regions. This
 413       // ensures that gaps between functions are marked correctly.
 414       startSegment(*Last, Last->endLoc(), false, true);
 415     }
 416
 417     // Pop the completed regions.
 418     ActiveRegions.erase(CompletedRegionsIt, ActiveRegions.end());
 419   }
 420
 421   void buildSegmentsImpl(ArrayRef<CountedRegion> Regions) {
 422     for (const auto &CR : enumerate(Regions)) {
 423       auto CurStartLoc = CR.value().startLoc();
 424
 425       // Active regions which end before the current region need to be popped.
 426       auto CompletedRegions =
 427           std::stable_partition(ActiveRegions.begin(), ActiveRegions.end(),
 428                                 [&](const CountedRegion *Region) {
 429                                   return !(Region->endLoc() <= CurStartLoc);
 430                                 });
 431       if (CompletedRegions != ActiveRegions.end()) {
 432         unsigned FirstCompletedRegion =
 433             std::distance(ActiveRegions.begin(), CompletedRegions);
 434         completeRegionsUntil(CurStartLoc, FirstCompletedRegion);
 435       }
 436
 437       bool GapRegion = CR.value().Kind == CounterMappingRegion::GapRegion;
 438
 439       // Try to emit a segment for the current region.
 440       if (CurStartLoc == CR.value().endLoc()) {
 441         // Avoid making zero-length regions active. If it's the last region,
 442         // emit a skipped segment. Otherwise use its predecessor's count.
 443         const bool Skipped = (CR.index() + 1) == Regions.size();
 444         startSegment(ActiveRegions.empty() ? CR.value() : *ActiveRegions.back(),
 445                      CurStartLoc, !GapRegion, Skipped);
 446         continue;
 447       }
 448       if (CR.index() + 1 == Regions.size() ||
 449           CurStartLoc != Regions[CR.index() + 1].startLoc()) {
 450         // Emit a segment if the next region doesn't start at the same location
 451         // as this one.
 452         startSegment(CR.value(), CurStartLoc, !GapRegion);
 453       }
 454
 455       // This region is active (i.e not completed).
 456       ActiveRegions.push_back(&CR.value());
 457     }
 458
 459     // Complete any remaining active regions.
 460     if (!ActiveRegions.empty())
 461       completeRegionsUntil(None, 0);
 462   }
 463
 464   /// Sort a nested sequence of regions from a single file.
 465   static void sortNestedRegions(MutableArrayRef<CountedRegion> Regions) {
 466     llvm::sort(Regions.begin(), Regions.end(), [](const CountedRegion &LHS,
 467                                                   const CountedRegion &RHS) {
 468       if (LHS.startLoc() != RHS.startLoc())
 469         return LHS.startLoc() < RHS.startLoc();
 470       if (LHS.endLoc() != RHS.endLoc())
 471         // When LHS completely contains RHS, we sort LHS first.
 472         return RHS.endLoc() < LHS.endLoc();
 473       // If LHS and RHS cover the same area, we need to sort them according
 474       // to their kinds so that the most suitable region will become "active"
 475       // in combineRegions(). Because we accumulate counter values only from
 476       // regions of the same kind as the first region of the area, prefer
 477       // CodeRegion to ExpansionRegion and ExpansionRegion to SkippedRegion.
 478       static_assert(CounterMappingRegion::CodeRegion <
 479                             CounterMappingRegion::ExpansionRegion &&
 480                         CounterMappingRegion::ExpansionRegion <
 481                             CounterMappingRegion::SkippedRegion,
 482                     "Unexpected order of region kind values");
 483       return LHS.Kind < RHS.Kind;
 484     });
 485   }
 486
 487   /// Combine counts of regions which cover the same area.
 488   static ArrayRef<CountedRegion>
 489   combineRegions(MutableArrayRef<CountedRegion> Regions) {
 490     if (Regions.empty())
 491       return Regions;
 492     auto Active = Regions.begin();
 493     auto End = Regions.end();
 494     for (auto I = Regions.begin() + 1; I != End; ++I) {
 495       if (Active->startLoc() != I->startLoc() ||
 496           Active->endLoc() != I->endLoc()) {
 497         // Shift to the next region.
 498         ++Active;
 499         if (Active != I)
 500           *Active = *I;
 501         continue;
 502       }
 503       // Merge duplicate region.
 504       // If CodeRegions and ExpansionRegions cover the same area, it's probably
 505       // a macro which is fully expanded to another macro. In that case, we need
 506       // to accumulate counts only from CodeRegions, or else the area will be
 507       // counted twice.
 508       // On the other hand, a macro may have a nested macro in its body. If the
 509       // outer macro is used several times, the ExpansionRegion for the nested
 510       // macro will also be added several times. These ExpansionRegions cover
 511       // the same source locations and have to be combined to reach the correct
 512       // value for that area.
 513       // We add counts of the regions of the same kind as the active region
 514       // to handle the both situations.
 515       if (I->Kind == Active->Kind)
 516         Active->ExecutionCount += I->ExecutionCount;
 517     }
 518     return Regions.drop_back(std::distance(++Active, End));
 519   }
 520
 521 public:
 522   /// Build a sorted list of CoverageSegments from a list of Regions.
 523   static std::vector<CoverageSegment>
 524   buildSegments(MutableArrayRef<CountedRegion> Regions) {
 525     std::vector<CoverageSegment> Segments;
 526     SegmentBuilder Builder(Segments);
 527
 528     sortNestedRegions(Regions);
 529     ArrayRef<CountedRegion> CombinedRegions = combineRegions(Regions);
 530
 531     LLVM_DEBUG({
 532       dbgs() << "Combined regions:\n";
 533       for (const auto &CR : CombinedRegions)
 534         dbgs() << "  " << CR.LineStart << ":" << CR.ColumnStart << " -> "
 535                << CR.LineEnd << ":" << CR.ColumnEnd
 536                << " (count=" << CR.ExecutionCount << ")\n";
 537     });
 538
 539     Builder.buildSegmentsImpl(CombinedRegions);
 540
 541 #ifndef NDEBUG
 542     for (unsigned I = 1, E = Segments.size(); I < E; ++I) {
 543       const auto &L = Segments[I - 1];
 544       const auto &R = Segments[I];
 545       if (!(L.Line < R.Line) && !(L.Line == R.Line && L.Col < R.Col)) {
 546         LLVM_DEBUG(dbgs() << " ! Segment " << L.Line << ":" << L.Col
 547                           << " followed by " << R.Line << ":" << R.Col << "\n");
 548         assert(false && "Coverage segments not unique or sorted");
 549       }
 550     }
 551 #endif
 552
 553     return Segments;
 554   }
 555 };
 556
 557 } // end anonymous namespace
 558
 559 std::vector<StringRef> CoverageMapping::getUniqueSourceFiles() const {
 560   std::vector<StringRef> Filenames;
 561   for (const auto &Function : getCoveredFunctions())
 562     Filenames.insert(Filenames.end(), Function.Filenames.begin(),
 563                      Function.Filenames.end());
 564   llvm::sort(Filenames.begin(), Filenames.end());
 565   auto Last = std::unique(Filenames.begin(), Filenames.end());
 566   Filenames.erase(Last, Filenames.end());
 567   return Filenames;
 568 }
 569
 570 static SmallBitVector gatherFileIDs(StringRef SourceFile,
 571                                     const FunctionRecord &Function) {
 572   SmallBitVector FilenameEquivalence(Function.Filenames.size(), false);
 573   for (unsigned I = 0, E = Function.Filenames.size(); I < E; ++I)
 574     if (SourceFile == Function.Filenames[I])
 575       FilenameEquivalence[I] = true;
 576   return FilenameEquivalence;
 577 }
 578
 579 /// Return the ID of the file where the definition of the function is located.
 580 static Optional<unsigned> findMainViewFileID(const FunctionRecord &Function) {
 581   SmallBitVector IsNotExpandedFile(Function.Filenames.size(), true);
 582   for (const auto &CR : Function.CountedRegions)
 583     if (CR.Kind == CounterMappingRegion::ExpansionRegion)
 584       IsNotExpandedFile[CR.ExpandedFileID] = false;
 585   int I = IsNotExpandedFile.find_first();
 586   if (I == -1)
 587     return None;
 588   return I;
 589 }
 590
 591 /// Check if SourceFile is the file that contains the definition of
 592 /// the Function. Return the ID of the file in that case or None otherwise.
 593 static Optional<unsigned> findMainViewFileID(StringRef SourceFile,
 594                                              const FunctionRecord &Function) {
 595   Optional<unsigned> I = findMainViewFileID(Function);
 596   if (I && SourceFile == Function.Filenames[*I])
 597     return I;
 598   return None;
 599 }
 600
 601 static bool isExpansion(const CountedRegion &R, unsigned FileID) {
 602   return R.Kind == CounterMappingRegion::ExpansionRegion && R.FileID == FileID;
 603 }
 604
 605 CoverageData CoverageMapping::getCoverageForFile(StringRef Filename) const {
 606   CoverageData FileCoverage(Filename);
 607   std::vector<CountedRegion> Regions;
 608
 609   for (const auto &Function : Functions) {
 610     auto MainFileID = findMainViewFileID(Filename, Function);
 611     auto FileIDs = gatherFileIDs(Filename, Function);
 612     for (const auto &CR : Function.CountedRegions)
 613       if (FileIDs.test(CR.FileID)) {
 614         Regions.push_back(CR);
 615         if (MainFileID && isExpansion(CR, *MainFileID))
 616           FileCoverage.Expansions.emplace_back(CR, Function);
 617       }
 618   }
 619
 620   LLVM_DEBUG(dbgs() << "Emitting segments for file: " << Filename << "\n");
 621   FileCoverage.Segments = SegmentBuilder::buildSegments(Regions);
 622
 623   return FileCoverage;
 624 }
 625
 626 std::vector<InstantiationGroup>
 627 CoverageMapping::getInstantiationGroups(StringRef Filename) const {
 628   FunctionInstantiationSetCollector InstantiationSetCollector;
 629   for (const auto &Function : Functions) {
 630     auto MainFileID = findMainViewFileID(Filename, Function);
 631     if (!MainFileID)
 632       continue;
 633     InstantiationSetCollector.insert(Function, *MainFileID);
 634   }
 635
 636   std::vector<InstantiationGroup> Result;
 637   for (auto &InstantiationSet : InstantiationSetCollector) {
 638     InstantiationGroup IG{InstantiationSet.first.first,
 639                           InstantiationSet.first.second,
 640                           std::move(InstantiationSet.second)};
 641     Result.emplace_back(std::move(IG));
 642   }
 643   return Result;
 644 }
 645
 646 CoverageData
 647 CoverageMapping::getCoverageForFunction(const FunctionRecord &Function) const {
 648   auto MainFileID = findMainViewFileID(Function);
 649   if (!MainFileID)
 650     return CoverageData();
 651
 652   CoverageData FunctionCoverage(Function.Filenames[*MainFileID]);
 653   std::vector<CountedRegion> Regions;
 654   for (const auto &CR : Function.CountedRegions)
 655     if (CR.FileID == *MainFileID) {
 656       Regions.push_back(CR);
 657       if (isExpansion(CR, *MainFileID))
 658         FunctionCoverage.Expansions.emplace_back(CR, Function);
 659     }
 660
 661   LLVM_DEBUG(dbgs() << "Emitting segments for function: " << Function.Name
 662                     << "\n");
 663   FunctionCoverage.Segments = SegmentBuilder::buildSegments(Regions);
 664
 665   return FunctionCoverage;
 666 }
 667
 668 CoverageData CoverageMapping::getCoverageForExpansion(
 669     const ExpansionRecord &Expansion) const {
 670   CoverageData ExpansionCoverage(
 671       Expansion.Function.Filenames[Expansion.FileID]);
 672   std::vector<CountedRegion> Regions;
 673   for (const auto &CR : Expansion.Function.CountedRegions)
 674     if (CR.FileID == Expansion.FileID) {
 675       Regions.push_back(CR);
 676       if (isExpansion(CR, Expansion.FileID))
 677         ExpansionCoverage.Expansions.emplace_back(CR, Expansion.Function);
 678     }
 679
 680   LLVM_DEBUG(dbgs() << "Emitting segments for expansion of file "
 681                     << Expansion.FileID << "\n");
 682   ExpansionCoverage.Segments = SegmentBuilder::buildSegments(Regions);
 683
 684   return ExpansionCoverage;
 685 }
 686
 687 LineCoverageStats::LineCoverageStats(
 688     ArrayRef<const CoverageSegment *> LineSegments,
 689     const CoverageSegment *WrappedSegment, unsigned Line)
 690     : ExecutionCount(0), HasMultipleRegions(false), Mapped(false), Line(Line),
 691       LineSegments(LineSegments), WrappedSegment(WrappedSegment) {
 692   // Find the minimum number of regions which start in this line.
 693   unsigned MinRegionCount = 0;
 694   auto isStartOfRegion = [](const CoverageSegment *S) {
 695     return !S->IsGapRegion && S->HasCount && S->IsRegionEntry;
 696   };
 697   for (unsigned I = 0; I < LineSegments.size() && MinRegionCount < 2; ++I)
 698     if (isStartOfRegion(LineSegments[I]))
 699       ++MinRegionCount;
 700
 701   bool StartOfSkippedRegion = !LineSegments.empty() &&
 702                               !LineSegments.front()->HasCount &&
 703                               LineSegments.front()->IsRegionEntry;
 704
 705   HasMultipleRegions = MinRegionCount > 1;
 706   Mapped =
 707       !StartOfSkippedRegion &&
 708       ((WrappedSegment && WrappedSegment->HasCount) || (MinRegionCount > 0));
 709
 710   if (!Mapped)
 711     return;
 712
 713   // Pick the max count from the non-gap, region entry segments and the
 714   // wrapped count.
 715   if (WrappedSegment)
 716     ExecutionCount = WrappedSegment->Count;
 717   if (!MinRegionCount)
 718     return;
 719   for (const auto *LS : LineSegments)
 720     if (isStartOfRegion(LS))
 721       ExecutionCount = std::max(ExecutionCount, LS->Count);
 722 }
 723
 724 LineCoverageIterator &LineCoverageIterator::operator++() {
 725   if (Next == CD.end()) {
 726     Stats = LineCoverageStats();
 727     Ended = true;
 728     return *this;
 729   }
 730   if (Segments.size())
 731     WrappedSegment = Segments.back();
 732   Segments.clear();
 733   while (Next != CD.end() && Next->Line == Line)
 734     Segments.push_back(&*Next++);
 735   Stats = LineCoverageStats(Segments, WrappedSegment, Line);
 736   ++Line;
 737   return *this;
 738 }
 739
 740 static std::string getCoverageMapErrString(coveragemap_error Err) {
 741   switch (Err) {
 742   case coveragemap_error::success:
 743     return "Success";
 744   case coveragemap_error::eof:
 745     return "End of File";
 746   case coveragemap_error::no_data_found:
 747     return "No coverage data found";
 748   case coveragemap_error::unsupported_version:
 749     return "Unsupported coverage format version";
 750   case coveragemap_error::truncated:
 751     return "Truncated coverage data";
 752   case coveragemap_error::malformed:
 753     return "Malformed coverage data";
 754   }
 755   llvm_unreachable("A value of coveragemap_error has no message.");
 756 }
 757
 758 namespace {
 759
 760 // FIXME: This class is only here to support the transition to llvm::Error. It
 761 // will be removed once this transition is complete. Clients should prefer to
 762 // deal with the Error value directly, rather than converting to error_code.
 763 class CoverageMappingErrorCategoryType : public std::error_category {
 764   const char *name() const noexcept override { return "llvm.coveragemap"; }
 765   std::string message(int IE) const override {
 766     return getCoverageMapErrString(static_cast<coveragemap_error>(IE));
 767   }
 768 };
 769
 770 } // end anonymous namespace
 771
 772 std::string CoverageMapError::message() const {
 773   return getCoverageMapErrString(Err);
 774 }
 775
 776 static ManagedStatic<CoverageMappingErrorCategoryType> ErrorCategory;
 777
 778 const std::error_category &llvm::coverage::coveragemap_category() {
 779   return *ErrorCategory;
 780 }
 781
 782 char CoverageMapError::ID = 0;