lib/ProfileData/Coverage/CoverageMapping.cpp

   1 //===- CoverageMapping.cpp - Code coverage mapping support ----------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains support for clang's and llvm's instrumentation based
  10 // code coverage.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ProfileData/Coverage/CoverageMapping.h"
  15 #include "llvm/ADT/ArrayRef.h"
  16 #include "llvm/ADT/DenseMap.h"
  17 #include "llvm/ADT/None.h"
  18 #include "llvm/ADT/Optional.h"
  19 #include "llvm/ADT/SmallBitVector.h"
  20 #include "llvm/ADT/SmallVector.h"
  21 #include "llvm/ADT/StringRef.h"
  22 #include "llvm/ProfileData/Coverage/CoverageMappingReader.h"
  23 #include "llvm/ProfileData/InstrProfReader.h"
  24 #include "llvm/Support/Debug.h"
  25 #include "llvm/Support/Errc.h"
  26 #include "llvm/Support/Error.h"
  27 #include "llvm/Support/ErrorHandling.h"
  28 #include "llvm/Support/ManagedStatic.h"
  29 #include "llvm/Support/MemoryBuffer.h"
  30 #include "llvm/Support/raw_ostream.h"
  31 #include <algorithm>
  32 #include <cassert>
  33 #include <cstdint>
  34 #include <iterator>
  35 #include <map>
  36 #include <memory>
  37 #include <string>
  38 #include <system_error>
  39 #include <utility>
  40 #include <vector>
  41
  42 using namespace llvm;
  43 using namespace coverage;
  44
  45 #define DEBUG_TYPE "coverage-mapping"
  46
  47 Counter CounterExpressionBuilder::get(const CounterExpression &E) {
  48   auto It = ExpressionIndices.find(E);
  49   if (It != ExpressionIndices.end())
  50     return Counter::getExpression(It->second);
  51   unsigned I = Expressions.size();
  52   Expressions.push_back(E);
  53   ExpressionIndices[E] = I;
  54   return Counter::getExpression(I);
  55 }
  56
  57 void CounterExpressionBuilder::extractTerms(Counter C, int Factor,
  58                                             SmallVectorImpl<Term> &Terms) {
  59   switch (C.getKind()) {
  60   case Counter::Zero:
  61     break;
  62   case Counter::CounterValueReference:
  63     Terms.emplace_back(C.getCounterID(), Factor);
  64     break;
  65   case Counter::Expression:
  66     const auto &E = Expressions[C.getExpressionID()];
  67     extractTerms(E.LHS, Factor, Terms);
  68     extractTerms(
  69         E.RHS, E.Kind == CounterExpression::Subtract ? -Factor : Factor, Terms);
  70     break;
  71   }
  72 }
  73
  74 Counter CounterExpressionBuilder::simplify(Counter ExpressionTree) {
  75   // Gather constant terms.
  76   SmallVector<Term, 32> Terms;
  77   extractTerms(ExpressionTree, +1, Terms);
  78
  79   // If there are no terms, this is just a zero. The algorithm below assumes at
  80   // least one term.
  81   if (Terms.size() == 0)
  82     return Counter::getZero();
  83
  84   // Group the terms by counter ID.
  85   llvm::sort(Terms, [](const Term &LHS, const Term &RHS) {
  86     return LHS.CounterID < RHS.CounterID;
  87   });
  88
  89   // Combine terms by counter ID to eliminate counters that sum to zero.
  90   auto Prev = Terms.begin();
  91   for (auto I = Prev + 1, E = Terms.end(); I != E; ++I) {
  92     if (I->CounterID == Prev->CounterID) {
  93       Prev->Factor += I->Factor;
  94       continue;
  95     }
  96     ++Prev;
  97     *Prev = *I;
  98   }
  99   Terms.erase(++Prev, Terms.end());
 100
 101   Counter C;
 102   // Create additions. We do this before subtractions to avoid constructs like
 103   // ((0 - X) + Y), as opposed to (Y - X).
 104   for (auto T : Terms) {
 105     if (T.Factor <= 0)
 106       continue;
 107     for (int I = 0; I < T.Factor; ++I)
 108       if (C.isZero())
 109         C = Counter::getCounter(T.CounterID);
 110       else
 111         C = get(CounterExpression(CounterExpression::Add, C,
 112                                   Counter::getCounter(T.CounterID)));
 113   }
 114
 115   // Create subtractions.
 116   for (auto T : Terms) {
 117     if (T.Factor >= 0)
 118       continue;
 119     for (int I = 0; I < -T.Factor; ++I)
 120       C = get(CounterExpression(CounterExpression::Subtract, C,
 121                                 Counter::getCounter(T.CounterID)));
 122   }
 123   return C;
 124 }
 125
 126 Counter CounterExpressionBuilder::add(Counter LHS, Counter RHS) {
 127   return simplify(get(CounterExpression(CounterExpression::Add, LHS, RHS)));
 128 }
 129
 130 Counter CounterExpressionBuilder::subtract(Counter LHS, Counter RHS) {
 131   return simplify(
 132       get(CounterExpression(CounterExpression::Subtract, LHS, RHS)));
 133 }
 134
 135 void CounterMappingContext::dump(const Counter &C, raw_ostream &OS) const {
 136   switch (C.getKind()) {
 137   case Counter::Zero:
 138     OS << '0';
 139     return;
 140   case Counter::CounterValueReference:
 141     OS << '#' << C.getCounterID();
 142     break;
 143   case Counter::Expression: {
 144     if (C.getExpressionID() >= Expressions.size())
 145       return;
 146     const auto &E = Expressions[C.getExpressionID()];
 147     OS << '(';
 148     dump(E.LHS, OS);
 149     OS << (E.Kind == CounterExpression::Subtract ? " - " : " + ");
 150     dump(E.RHS, OS);
 151     OS << ')';
 152     break;
 153   }
 154   }
 155   if (CounterValues.empty())
 156     return;
 157   Expected<int64_t> Value = evaluate(C);
 158   if (auto E = Value.takeError()) {
 159     consumeError(std::move(E));
 160     return;
 161   }
 162   OS << '[' << *Value << ']';
 163 }
 164
 165 Expected<int64_t> CounterMappingContext::evaluate(const Counter &C) const {
 166   switch (C.getKind()) {
 167   case Counter::Zero:
 168     return 0;
 169   case Counter::CounterValueReference:
 170     if (C.getCounterID() >= CounterValues.size())
 171       return errorCodeToError(errc::argument_out_of_domain);
 172     return CounterValues[C.getCounterID()];
 173   case Counter::Expression: {
 174     if (C.getExpressionID() >= Expressions.size())
 175       return errorCodeToError(errc::argument_out_of_domain);
 176     const auto &E = Expressions[C.getExpressionID()];
 177     Expected<int64_t> LHS = evaluate(E.LHS);
 178     if (!LHS)
 179       return LHS;
 180     Expected<int64_t> RHS = evaluate(E.RHS);
 181     if (!RHS)
 182       return RHS;
 183     return E.Kind == CounterExpression::Subtract ? *LHS - *RHS : *LHS + *RHS;
 184   }
 185   }
 186   llvm_unreachable("Unhandled CounterKind");
 187 }
 188
 189 void FunctionRecordIterator::skipOtherFiles() {
 190   while (Current != Records.end() && !Filename.empty() &&
 191          Filename != Current->Filenames[0])
 192     ++Current;
 193   if (Current == Records.end())
 194     *this = FunctionRecordIterator();
 195 }
 196
 197 Error CoverageMapping::loadFunctionRecord(
 198     const CoverageMappingRecord &Record,
 199     IndexedInstrProfReader &ProfileReader) {
 200   StringRef OrigFuncName = Record.FunctionName;
 201   if (OrigFuncName.empty())
 202     return make_error<CoverageMapError>(coveragemap_error::malformed);
 203
 204   if (Record.Filenames.empty())
 205     OrigFuncName = getFuncNameWithoutPrefix(OrigFuncName);
 206   else
 207     OrigFuncName = getFuncNameWithoutPrefix(OrigFuncName, Record.Filenames[0]);
 208
 209   CounterMappingContext Ctx(Record.Expressions);
 210
 211   std::vector<uint64_t> Counts;
 212   if (Error E = ProfileReader.getFunctionCounts(Record.FunctionName,
 213                                                 Record.FunctionHash, Counts)) {
 214     instrprof_error IPE = InstrProfError::take(std::move(E));
 215     if (IPE == instrprof_error::hash_mismatch) {
 216       FuncHashMismatches.emplace_back(Record.FunctionName, Record.FunctionHash);
 217       return Error::success();
 218     } else if (IPE != instrprof_error::unknown_function)
 219       return make_error<InstrProfError>(IPE);
 220     Counts.assign(Record.MappingRegions.size(), 0);
 221   }
 222   Ctx.setCounts(Counts);
 223
 224   assert(!Record.MappingRegions.empty() && "Function has no regions");
 225
 226   // This coverage record is a zero region for a function that's unused in
 227   // some TU, but used in a different TU. Ignore it. The coverage maps from the
 228   // the other TU will either be loaded (providing full region counts) or they
 229   // won't (in which case we don't unintuitively report functions as uncovered
 230   // when they have non-zero counts in the profile).
 231   if (Record.MappingRegions.size() == 1 &&
 232       Record.MappingRegions[0].Count.isZero() && Counts[0] > 0)
 233     return Error::success();
 234
 235   FunctionRecord Function(OrigFuncName, Record.Filenames);
 236   for (const auto &Region : Record.MappingRegions) {
 237     Expected<int64_t> ExecutionCount = Ctx.evaluate(Region.Count);
 238     if (auto E = ExecutionCount.takeError()) {
 239       consumeError(std::move(E));
 240       return Error::success();
 241     }
 242     Function.pushRegion(Region, *ExecutionCount);
 243   }
 244
 245   // Don't create records for (filenames, function) pairs we've already seen.
 246   auto FilenamesHash = hash_combine_range(Record.Filenames.begin(),
 247                                           Record.Filenames.end());
 248   if (!RecordProvenance[FilenamesHash].insert(hash_value(OrigFuncName)).second)
 249     return Error::success();
 250
 251   Functions.push_back(std::move(Function));
 252   return Error::success();
 253 }
 254
 255 Expected<std::unique_ptr<CoverageMapping>> CoverageMapping::load(
 256     ArrayRef<std::unique_ptr<CoverageMappingReader>> CoverageReaders,
 257     IndexedInstrProfReader &ProfileReader) {
 258   auto Coverage = std::unique_ptr<CoverageMapping>(new CoverageMapping());
 259
 260   for (const auto &CoverageReader : CoverageReaders) {
 261     for (auto RecordOrErr : *CoverageReader) {
 262       if (Error E = RecordOrErr.takeError())
 263         return std::move(E);
 264       const auto &Record = *RecordOrErr;
 265       if (Error E = Coverage->loadFunctionRecord(Record, ProfileReader))
 266         return std::move(E);
 267     }
 268   }
 269
 270   return std::move(Coverage);
 271 }
 272
 273 Expected<std::unique_ptr<CoverageMapping>>
 274 CoverageMapping::load(ArrayRef<StringRef> ObjectFilenames,
 275                       StringRef ProfileFilename, ArrayRef<StringRef> Arches) {
 276   auto ProfileReaderOrErr = IndexedInstrProfReader::create(ProfileFilename);
 277   if (Error E = ProfileReaderOrErr.takeError())
 278     return std::move(E);
 279   auto ProfileReader = std::move(ProfileReaderOrErr.get());
 280
 281   SmallVector<std::unique_ptr<CoverageMappingReader>, 4> Readers;
 282   SmallVector<std::unique_ptr<MemoryBuffer>, 4> Buffers;
 283   for (const auto &File : llvm::enumerate(ObjectFilenames)) {
 284     auto CovMappingBufOrErr = MemoryBuffer::getFileOrSTDIN(File.value());
 285     if (std::error_code EC = CovMappingBufOrErr.getError())
 286       return errorCodeToError(EC);
 287     StringRef Arch = Arches.empty() ? StringRef() : Arches[File.index()];
 288     MemoryBufferRef CovMappingBufRef =
 289         CovMappingBufOrErr.get()->getMemBufferRef();
 290     auto CoverageReadersOrErr =
 291         BinaryCoverageReader::create(CovMappingBufRef, Arch, Buffers);
 292     if (Error E = CoverageReadersOrErr.takeError())
 293       return std::move(E);
 294     for (auto &Reader : CoverageReadersOrErr.get())
 295       Readers.push_back(std::move(Reader));
 296     Buffers.push_back(std::move(CovMappingBufOrErr.get()));
 297   }
 298   return load(Readers, *ProfileReader);
 299 }
 300
 301 namespace {
 302
 303 /// Distributes functions into instantiation sets.
 304 ///
 305 /// An instantiation set is a collection of functions that have the same source
 306 /// code, ie, template functions specializations.
 307 class FunctionInstantiationSetCollector {
 308   using MapT = std::map<LineColPair, std::vector<const FunctionRecord *>>;
 309   MapT InstantiatedFunctions;
 310
 311 public:
 312   void insert(const FunctionRecord &Function, unsigned FileID) {
 313     auto I = Function.CountedRegions.begin(), E = Function.CountedRegions.end();
 314     while (I != E && I->FileID != FileID)
 315       ++I;
 316     assert(I != E && "function does not cover the given file");
 317     auto &Functions = InstantiatedFunctions[I->startLoc()];
 318     Functions.push_back(&Function);
 319   }
 320
 321   MapT::iterator begin() { return InstantiatedFunctions.begin(); }
 322   MapT::iterator end() { return InstantiatedFunctions.end(); }
 323 };
 324
 325 class SegmentBuilder {
 326   std::vector<CoverageSegment> &Segments;
 327   SmallVector<const CountedRegion *, 8> ActiveRegions;
 328
 329   SegmentBuilder(std::vector<CoverageSegment> &Segments) : Segments(Segments) {}
 330
 331   /// Emit a segment with the count from \p Region starting at \p StartLoc.
 332   //
 333   /// \p IsRegionEntry: The segment is at the start of a new non-gap region.
 334   /// \p EmitSkippedRegion: The segment must be emitted as a skipped region.
 335   void startSegment(const CountedRegion &Region, LineColPair StartLoc,
 336                     bool IsRegionEntry, bool EmitSkippedRegion = false) {
 337     bool HasCount = !EmitSkippedRegion &&
 338                     (Region.Kind != CounterMappingRegion::SkippedRegion);
 339
 340     // If the new segment wouldn't affect coverage rendering, skip it.
 341     if (!Segments.empty() && !IsRegionEntry && !EmitSkippedRegion) {
 342       const auto &Last = Segments.back();
 343       if (Last.HasCount == HasCount && Last.Count == Region.ExecutionCount &&
 344           !Last.IsRegionEntry)
 345         return;
 346     }
 347
 348     if (HasCount)
 349       Segments.emplace_back(StartLoc.first, StartLoc.second,
 350                             Region.ExecutionCount, IsRegionEntry,
 351                             Region.Kind == CounterMappingRegion::GapRegion);
 352     else
 353       Segments.emplace_back(StartLoc.first, StartLoc.second, IsRegionEntry);
 354
 355     LLVM_DEBUG({
 356       const auto &Last = Segments.back();
 357       dbgs() << "Segment at " << Last.Line << ":" << Last.Col
 358              << " (count = " << Last.Count << ")"
 359              << (Last.IsRegionEntry ? ", RegionEntry" : "")
 360              << (!Last.HasCount ? ", Skipped" : "")
 361              << (Last.IsGapRegion ? ", Gap" : "") << "\n";
 362     });
 363   }
 364
 365   /// Emit segments for active regions which end before \p Loc.
 366   ///
 367   /// \p Loc: The start location of the next region. If None, all active
 368   /// regions are completed.
 369   /// \p FirstCompletedRegion: Index of the first completed region.
 370   void completeRegionsUntil(Optional<LineColPair> Loc,
 371                             unsigned FirstCompletedRegion) {
 372     // Sort the completed regions by end location. This makes it simple to
 373     // emit closing segments in sorted order.
 374     auto CompletedRegionsIt = ActiveRegions.begin() + FirstCompletedRegion;
 375     std::stable_sort(CompletedRegionsIt, ActiveRegions.end(),
 376                       [](const CountedRegion *L, const CountedRegion *R) {
 377                         return L->endLoc() < R->endLoc();
 378                       });
 379
 380     // Emit segments for all completed regions.
 381     for (unsigned I = FirstCompletedRegion + 1, E = ActiveRegions.size(); I < E;
 382          ++I) {
 383       const auto *CompletedRegion = ActiveRegions[I];
 384       assert((!Loc || CompletedRegion->endLoc() <= *Loc) &&
 385              "Completed region ends after start of new region");
 386
 387       const auto *PrevCompletedRegion = ActiveRegions[I - 1];
 388       auto CompletedSegmentLoc = PrevCompletedRegion->endLoc();
 389
 390       // Don't emit any more segments if they start where the new region begins.
 391       if (Loc && CompletedSegmentLoc == *Loc)
 392         break;
 393
 394       // Don't emit a segment if the next completed region ends at the same
 395       // location as this one.
 396       if (CompletedSegmentLoc == CompletedRegion->endLoc())
 397         continue;
 398
 399       // Use the count from the last completed region which ends at this loc.
 400       for (unsigned J = I + 1; J < E; ++J)
 401         if (CompletedRegion->endLoc() == ActiveRegions[J]->endLoc())
 402           CompletedRegion = ActiveRegions[J];
 403
 404       startSegment(*CompletedRegion, CompletedSegmentLoc, false);
 405     }
 406
 407     auto Last = ActiveRegions.back();
 408     if (FirstCompletedRegion && Last->endLoc() != *Loc) {
 409       // If there's a gap after the end of the last completed region and the
 410       // start of the new region, use the last active region to fill the gap.
 411       startSegment(*ActiveRegions[FirstCompletedRegion - 1], Last->endLoc(),
 412                    false);
 413     } else if (!FirstCompletedRegion && (!Loc || *Loc != Last->endLoc())) {
 414       // Emit a skipped segment if there are no more active regions. This
 415       // ensures that gaps between functions are marked correctly.
 416       startSegment(*Last, Last->endLoc(), false, true);
 417     }
 418
 419     // Pop the completed regions.
 420     ActiveRegions.erase(CompletedRegionsIt, ActiveRegions.end());
 421   }
 422
 423   void buildSegmentsImpl(ArrayRef<CountedRegion> Regions) {
 424     for (const auto &CR : enumerate(Regions)) {
 425       auto CurStartLoc = CR.value().startLoc();
 426
 427       // Active regions which end before the current region need to be popped.
 428       auto CompletedRegions =
 429           std::stable_partition(ActiveRegions.begin(), ActiveRegions.end(),
 430                                 [&](const CountedRegion *Region) {
 431                                   return !(Region->endLoc() <= CurStartLoc);
 432                                 });
 433       if (CompletedRegions != ActiveRegions.end()) {
 434         unsigned FirstCompletedRegion =
 435             std::distance(ActiveRegions.begin(), CompletedRegions);
 436         completeRegionsUntil(CurStartLoc, FirstCompletedRegion);
 437       }
 438
 439       bool GapRegion = CR.value().Kind == CounterMappingRegion::GapRegion;
 440
 441       // Try to emit a segment for the current region.
 442       if (CurStartLoc == CR.value().endLoc()) {
 443         // Avoid making zero-length regions active. If it's the last region,
 444         // emit a skipped segment. Otherwise use its predecessor's count.
 445         const bool Skipped = (CR.index() + 1) == Regions.size();
 446         startSegment(ActiveRegions.empty() ? CR.value() : *ActiveRegions.back(),
 447                      CurStartLoc, !GapRegion, Skipped);
 448         continue;
 449       }
 450       if (CR.index() + 1 == Regions.size() ||
 451           CurStartLoc != Regions[CR.index() + 1].startLoc()) {
 452         // Emit a segment if the next region doesn't start at the same location
 453         // as this one.
 454         startSegment(CR.value(), CurStartLoc, !GapRegion);
 455       }
 456
 457       // This region is active (i.e not completed).
 458       ActiveRegions.push_back(&CR.value());
 459     }
 460
 461     // Complete any remaining active regions.
 462     if (!ActiveRegions.empty())
 463       completeRegionsUntil(None, 0);
 464   }
 465
 466   /// Sort a nested sequence of regions from a single file.
 467   static void sortNestedRegions(MutableArrayRef<CountedRegion> Regions) {
 468     llvm::sort(Regions, [](const CountedRegion &LHS, const CountedRegion &RHS) {
 469       if (LHS.startLoc() != RHS.startLoc())
 470         return LHS.startLoc() < RHS.startLoc();
 471       if (LHS.endLoc() != RHS.endLoc())
 472         // When LHS completely contains RHS, we sort LHS first.
 473         return RHS.endLoc() < LHS.endLoc();
 474       // If LHS and RHS cover the same area, we need to sort them according
 475       // to their kinds so that the most suitable region will become "active"
 476       // in combineRegions(). Because we accumulate counter values only from
 477       // regions of the same kind as the first region of the area, prefer
 478       // CodeRegion to ExpansionRegion and ExpansionRegion to SkippedRegion.
 479       static_assert(CounterMappingRegion::CodeRegion <
 480                             CounterMappingRegion::ExpansionRegion &&
 481                         CounterMappingRegion::ExpansionRegion <
 482                             CounterMappingRegion::SkippedRegion,
 483                     "Unexpected order of region kind values");
 484       return LHS.Kind < RHS.Kind;
 485     });
 486   }
 487
 488   /// Combine counts of regions which cover the same area.
 489   static ArrayRef<CountedRegion>
 490   combineRegions(MutableArrayRef<CountedRegion> Regions) {
 491     if (Regions.empty())
 492       return Regions;
 493     auto Active = Regions.begin();
 494     auto End = Regions.end();
 495     for (auto I = Regions.begin() + 1; I != End; ++I) {
 496       if (Active->startLoc() != I->startLoc() ||
 497           Active->endLoc() != I->endLoc()) {
 498         // Shift to the next region.
 499         ++Active;
 500         if (Active != I)
 501           *Active = *I;
 502         continue;
 503       }
 504       // Merge duplicate region.
 505       // If CodeRegions and ExpansionRegions cover the same area, it's probably
 506       // a macro which is fully expanded to another macro. In that case, we need
 507       // to accumulate counts only from CodeRegions, or else the area will be
 508       // counted twice.
 509       // On the other hand, a macro may have a nested macro in its body. If the
 510       // outer macro is used several times, the ExpansionRegion for the nested
 511       // macro will also be added several times. These ExpansionRegions cover
 512       // the same source locations and have to be combined to reach the correct
 513       // value for that area.
 514       // We add counts of the regions of the same kind as the active region
 515       // to handle the both situations.
 516       if (I->Kind == Active->Kind)
 517         Active->ExecutionCount += I->ExecutionCount;
 518     }
 519     return Regions.drop_back(std::distance(++Active, End));
 520   }
 521
 522 public:
 523   /// Build a sorted list of CoverageSegments from a list of Regions.
 524   static std::vector<CoverageSegment>
 525   buildSegments(MutableArrayRef<CountedRegion> Regions) {
 526     std::vector<CoverageSegment> Segments;
 527     SegmentBuilder Builder(Segments);
 528
 529     sortNestedRegions(Regions);
 530     ArrayRef<CountedRegion> CombinedRegions = combineRegions(Regions);
 531
 532     LLVM_DEBUG({
 533       dbgs() << "Combined regions:\n";
 534       for (const auto &CR : CombinedRegions)
 535         dbgs() << "  " << CR.LineStart << ":" << CR.ColumnStart << " -> "
 536                << CR.LineEnd << ":" << CR.ColumnEnd
 537                << " (count=" << CR.ExecutionCount << ")\n";
 538     });
 539
 540     Builder.buildSegmentsImpl(CombinedRegions);
 541
 542 #ifndef NDEBUG
 543     for (unsigned I = 1, E = Segments.size(); I < E; ++I) {
 544       const auto &L = Segments[I - 1];
 545       const auto &R = Segments[I];
 546       if (!(L.Line < R.Line) && !(L.Line == R.Line && L.Col < R.Col)) {
 547         LLVM_DEBUG(dbgs() << " ! Segment " << L.Line << ":" << L.Col
 548                           << " followed by " << R.Line << ":" << R.Col << "\n");
 549         assert(false && "Coverage segments not unique or sorted");
 550       }
 551     }
 552 #endif
 553
 554     return Segments;
 555   }
 556 };
 557
 558 } // end anonymous namespace
 559
 560 std::vector<StringRef> CoverageMapping::getUniqueSourceFiles() const {
 561   std::vector<StringRef> Filenames;
 562   for (const auto &Function : getCoveredFunctions())
 563     Filenames.insert(Filenames.end(), Function.Filenames.begin(),
 564                      Function.Filenames.end());
 565   llvm::sort(Filenames);
 566   auto Last = std::unique(Filenames.begin(), Filenames.end());
 567   Filenames.erase(Last, Filenames.end());
 568   return Filenames;
 569 }
 570
 571 static SmallBitVector gatherFileIDs(StringRef SourceFile,
 572                                     const FunctionRecord &Function) {
 573   SmallBitVector FilenameEquivalence(Function.Filenames.size(), false);
 574   for (unsigned I = 0, E = Function.Filenames.size(); I < E; ++I)
 575     if (SourceFile == Function.Filenames[I])
 576       FilenameEquivalence[I] = true;
 577   return FilenameEquivalence;
 578 }
 579
 580 /// Return the ID of the file where the definition of the function is located.
 581 static Optional<unsigned> findMainViewFileID(const FunctionRecord &Function) {
 582   SmallBitVector IsNotExpandedFile(Function.Filenames.size(), true);
 583   for (const auto &CR : Function.CountedRegions)
 584     if (CR.Kind == CounterMappingRegion::ExpansionRegion)
 585       IsNotExpandedFile[CR.ExpandedFileID] = false;
 586   int I = IsNotExpandedFile.find_first();
 587   if (I == -1)
 588     return None;
 589   return I;
 590 }
 591
 592 /// Check if SourceFile is the file that contains the definition of
 593 /// the Function. Return the ID of the file in that case or None otherwise.
 594 static Optional<unsigned> findMainViewFileID(StringRef SourceFile,
 595                                              const FunctionRecord &Function) {
 596   Optional<unsigned> I = findMainViewFileID(Function);
 597   if (I && SourceFile == Function.Filenames[*I])
 598     return I;
 599   return None;
 600 }
 601
 602 static bool isExpansion(const CountedRegion &R, unsigned FileID) {
 603   return R.Kind == CounterMappingRegion::ExpansionRegion && R.FileID == FileID;
 604 }
 605
 606 CoverageData CoverageMapping::getCoverageForFile(StringRef Filename) const {
 607   CoverageData FileCoverage(Filename);
 608   std::vector<CountedRegion> Regions;
 609
 610   for (const auto &Function : Functions) {
 611     auto MainFileID = findMainViewFileID(Filename, Function);
 612     auto FileIDs = gatherFileIDs(Filename, Function);
 613     for (const auto &CR : Function.CountedRegions)
 614       if (FileIDs.test(CR.FileID)) {
 615         Regions.push_back(CR);
 616         if (MainFileID && isExpansion(CR, *MainFileID))
 617           FileCoverage.Expansions.emplace_back(CR, Function);
 618       }
 619   }
 620
 621   LLVM_DEBUG(dbgs() << "Emitting segments for file: " << Filename << "\n");
 622   FileCoverage.Segments = SegmentBuilder::buildSegments(Regions);
 623
 624   return FileCoverage;
 625 }
 626
 627 std::vector<InstantiationGroup>
 628 CoverageMapping::getInstantiationGroups(StringRef Filename) const {
 629   FunctionInstantiationSetCollector InstantiationSetCollector;
 630   for (const auto &Function : Functions) {
 631     auto MainFileID = findMainViewFileID(Filename, Function);
 632     if (!MainFileID)
 633       continue;
 634     InstantiationSetCollector.insert(Function, *MainFileID);
 635   }
 636
 637   std::vector<InstantiationGroup> Result;
 638   for (auto &InstantiationSet : InstantiationSetCollector) {
 639     InstantiationGroup IG{InstantiationSet.first.first,
 640                           InstantiationSet.first.second,
 641                           std::move(InstantiationSet.second)};
 642     Result.emplace_back(std::move(IG));
 643   }
 644   return Result;
 645 }
 646
 647 CoverageData
 648 CoverageMapping::getCoverageForFunction(const FunctionRecord &Function) const {
 649   auto MainFileID = findMainViewFileID(Function);
 650   if (!MainFileID)
 651     return CoverageData();
 652
 653   CoverageData FunctionCoverage(Function.Filenames[*MainFileID]);
 654   std::vector<CountedRegion> Regions;
 655   for (const auto &CR : Function.CountedRegions)
 656     if (CR.FileID == *MainFileID) {
 657       Regions.push_back(CR);
 658       if (isExpansion(CR, *MainFileID))
 659         FunctionCoverage.Expansions.emplace_back(CR, Function);
 660     }
 661
 662   LLVM_DEBUG(dbgs() << "Emitting segments for function: " << Function.Name
 663                     << "\n");
 664   FunctionCoverage.Segments = SegmentBuilder::buildSegments(Regions);
 665
 666   return FunctionCoverage;
 667 }
 668
 669 CoverageData CoverageMapping::getCoverageForExpansion(
 670     const ExpansionRecord &Expansion) const {
 671   CoverageData ExpansionCoverage(
 672       Expansion.Function.Filenames[Expansion.FileID]);
 673   std::vector<CountedRegion> Regions;
 674   for (const auto &CR : Expansion.Function.CountedRegions)
 675     if (CR.FileID == Expansion.FileID) {
 676       Regions.push_back(CR);
 677       if (isExpansion(CR, Expansion.FileID))
 678         ExpansionCoverage.Expansions.emplace_back(CR, Expansion.Function);
 679     }
 680
 681   LLVM_DEBUG(dbgs() << "Emitting segments for expansion of file "
 682                     << Expansion.FileID << "\n");
 683   ExpansionCoverage.Segments = SegmentBuilder::buildSegments(Regions);
 684
 685   return ExpansionCoverage;
 686 }
 687
 688 LineCoverageStats::LineCoverageStats(
 689     ArrayRef<const CoverageSegment *> LineSegments,
 690     const CoverageSegment *WrappedSegment, unsigned Line)
 691     : ExecutionCount(0), HasMultipleRegions(false), Mapped(false), Line(Line),
 692       LineSegments(LineSegments), WrappedSegment(WrappedSegment) {
 693   // Find the minimum number of regions which start in this line.
 694   unsigned MinRegionCount = 0;
 695   auto isStartOfRegion = [](const CoverageSegment *S) {
 696     return !S->IsGapRegion && S->HasCount && S->IsRegionEntry;
 697   };
 698   for (unsigned I = 0; I < LineSegments.size() && MinRegionCount < 2; ++I)
 699     if (isStartOfRegion(LineSegments[I]))
 700       ++MinRegionCount;
 701
 702   bool StartOfSkippedRegion = !LineSegments.empty() &&
 703                               !LineSegments.front()->HasCount &&
 704                               LineSegments.front()->IsRegionEntry;
 705
 706   HasMultipleRegions = MinRegionCount > 1;
 707   Mapped =
 708       !StartOfSkippedRegion &&
 709       ((WrappedSegment && WrappedSegment->HasCount) || (MinRegionCount > 0));
 710
 711   if (!Mapped)
 712     return;
 713
 714   // Pick the max count from the non-gap, region entry segments and the
 715   // wrapped count.
 716   if (WrappedSegment)
 717     ExecutionCount = WrappedSegment->Count;
 718   if (!MinRegionCount)
 719     return;
 720   for (const auto *LS : LineSegments)
 721     if (isStartOfRegion(LS))
 722       ExecutionCount = std::max(ExecutionCount, LS->Count);
 723 }
 724
 725 LineCoverageIterator &LineCoverageIterator::operator++() {
 726   if (Next == CD.end()) {
 727     Stats = LineCoverageStats();
 728     Ended = true;
 729     return *this;
 730   }
 731   if (Segments.size())
 732     WrappedSegment = Segments.back();
 733   Segments.clear();
 734   while (Next != CD.end() && Next->Line == Line)
 735     Segments.push_back(&*Next++);
 736   Stats = LineCoverageStats(Segments, WrappedSegment, Line);
 737   ++Line;
 738   return *this;
 739 }
 740
 741 static std::string getCoverageMapErrString(coveragemap_error Err) {
 742   switch (Err) {
 743   case coveragemap_error::success:
 744     return "Success";
 745   case coveragemap_error::eof:
 746     return "End of File";
 747   case coveragemap_error::no_data_found:
 748     return "No coverage data found";
 749   case coveragemap_error::unsupported_version:
 750     return "Unsupported coverage format version";
 751   case coveragemap_error::truncated:
 752     return "Truncated coverage data";
 753   case coveragemap_error::malformed:
 754     return "Malformed coverage data";
 755   }
 756   llvm_unreachable("A value of coveragemap_error has no message.");
 757 }
 758
 759 namespace {
 760
 761 // FIXME: This class is only here to support the transition to llvm::Error. It
 762 // will be removed once this transition is complete. Clients should prefer to
 763 // deal with the Error value directly, rather than converting to error_code.
 764 class CoverageMappingErrorCategoryType : public std::error_category {
 765   const char *name() const noexcept override { return "llvm.coveragemap"; }
 766   std::string message(int IE) const override {
 767     return getCoverageMapErrString(static_cast<coveragemap_error>(IE));
 768   }
 769 };
 770
 771 } // end anonymous namespace
 772
 773 std::string CoverageMapError::message() const {
 774   return getCoverageMapErrString(Err);
 775 }
 776
 777 static ManagedStatic<CoverageMappingErrorCategoryType> ErrorCategory;
 778
 779 const std::error_category &llvm::coverage::coveragemap_category() {
 780   return *ErrorCategory;
 781 }
 782
 783 char CoverageMapError::ID = 0;