src/llvm/lib/ProfileData/CoverageMapping.cpp

   1 //=-- CoverageMapping.cpp - 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 // This file contains support for clang's and llvm's instrumentation based
  11 // code coverage.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/ProfileData/CoverageMapping.h"
  16 #include "llvm/ADT/DenseMap.h"
  17 #include "llvm/ADT/Optional.h"
  18 #include "llvm/ADT/SmallSet.h"
  19 #include "llvm/ProfileData/CoverageMappingReader.h"
  20 #include "llvm/ProfileData/InstrProfReader.h"
  21 #include "llvm/Support/Debug.h"
  22 #include "llvm/Support/ErrorHandling.h"
  23
  24 using namespace llvm;
  25 using namespace coverage;
  26
  27 #define DEBUG_TYPE "coverage-mapping"
  28
  29 Counter CounterExpressionBuilder::get(const CounterExpression &E) {
  30   auto It = ExpressionIndices.find(E);
  31   if (It != ExpressionIndices.end())
  32     return Counter::getExpression(It->second);
  33   unsigned I = Expressions.size();
  34   Expressions.push_back(E);
  35   ExpressionIndices[E] = I;
  36   return Counter::getExpression(I);
  37 }
  38
  39 void CounterExpressionBuilder::extractTerms(
  40     Counter C, int Sign, SmallVectorImpl<std::pair<unsigned, int>> &Terms) {
  41   switch (C.getKind()) {
  42   case Counter::Zero:
  43     break;
  44   case Counter::CounterValueReference:
  45     Terms.push_back(std::make_pair(C.getCounterID(), Sign));
  46     break;
  47   case Counter::Expression:
  48     const auto &E = Expressions[C.getExpressionID()];
  49     extractTerms(E.LHS, Sign, Terms);
  50     extractTerms(E.RHS, E.Kind == CounterExpression::Subtract ? -Sign : Sign,
  51                  Terms);
  52     break;
  53   }
  54 }
  55
  56 Counter CounterExpressionBuilder::simplify(Counter ExpressionTree) {
  57   // Gather constant terms.
  58   llvm::SmallVector<std::pair<unsigned, int>, 32> Terms;
  59   extractTerms(ExpressionTree, +1, Terms);
  60
  61   // If there are no terms, this is just a zero. The algorithm below assumes at
  62   // least one term.
  63   if (Terms.size() == 0)
  64     return Counter::getZero();
  65
  66   // Group the terms by counter ID.
  67   std::sort(Terms.begin(), Terms.end(),
  68             [](const std::pair<unsigned, int> &LHS,
  69                const std::pair<unsigned, int> &RHS) {
  70     return LHS.first < RHS.first;
  71   });
  72
  73   // Combine terms by counter ID to eliminate counters that sum to zero.
  74   auto Prev = Terms.begin();
  75   for (auto I = Prev + 1, E = Terms.end(); I != E; ++I) {
  76     if (I->first == Prev->first) {
  77       Prev->second += I->second;
  78       continue;
  79     }
  80     ++Prev;
  81     *Prev = *I;
  82   }
  83   Terms.erase(++Prev, Terms.end());
  84
  85   Counter C;
  86   // Create additions. We do this before subtractions to avoid constructs like
  87   // ((0 - X) + Y), as opposed to (Y - X).
  88   for (auto Term : Terms) {
  89     if (Term.second <= 0)
  90       continue;
  91     for (int I = 0; I < Term.second; ++I)
  92       if (C.isZero())
  93         C = Counter::getCounter(Term.first);
  94       else
  95         C = get(CounterExpression(CounterExpression::Add, C,
  96                                   Counter::getCounter(Term.first)));
  97   }
  98
  99   // Create subtractions.
 100   for (auto Term : Terms) {
 101     if (Term.second >= 0)
 102       continue;
 103     for (int I = 0; I < -Term.second; ++I)
 104       C = get(CounterExpression(CounterExpression::Subtract, C,
 105                                 Counter::getCounter(Term.first)));
 106   }
 107   return C;
 108 }
 109
 110 Counter CounterExpressionBuilder::add(Counter LHS, Counter RHS) {
 111   return simplify(get(CounterExpression(CounterExpression::Add, LHS, RHS)));
 112 }
 113
 114 Counter CounterExpressionBuilder::subtract(Counter LHS, Counter RHS) {
 115   return simplify(
 116       get(CounterExpression(CounterExpression::Subtract, LHS, RHS)));
 117 }
 118
 119 void CounterMappingContext::dump(const Counter &C,
 120                                  llvm::raw_ostream &OS) const {
 121   switch (C.getKind()) {
 122   case Counter::Zero:
 123     OS << '0';
 124     return;
 125   case Counter::CounterValueReference:
 126     OS << '#' << C.getCounterID();
 127     break;
 128   case Counter::Expression: {
 129     if (C.getExpressionID() >= Expressions.size())
 130       return;
 131     const auto &E = Expressions[C.getExpressionID()];
 132     OS << '(';
 133     dump(E.LHS, OS);
 134     OS << (E.Kind == CounterExpression::Subtract ? " - " : " + ");
 135     dump(E.RHS, OS);
 136     OS << ')';
 137     break;
 138   }
 139   }
 140   if (CounterValues.empty())
 141     return;
 142   ErrorOr<int64_t> Value = evaluate(C);
 143   if (!Value)
 144     return;
 145   OS << '[' << *Value << ']';
 146 }
 147
 148 ErrorOr<int64_t> CounterMappingContext::evaluate(const Counter &C) const {
 149   switch (C.getKind()) {
 150   case Counter::Zero:
 151     return 0;
 152   case Counter::CounterValueReference:
 153     if (C.getCounterID() >= CounterValues.size())
 154       return std::make_error_code(std::errc::argument_out_of_domain);
 155     return CounterValues[C.getCounterID()];
 156   case Counter::Expression: {
 157     if (C.getExpressionID() >= Expressions.size())
 158       return std::make_error_code(std::errc::argument_out_of_domain);
 159     const auto &E = Expressions[C.getExpressionID()];
 160     ErrorOr<int64_t> LHS = evaluate(E.LHS);
 161     if (!LHS)
 162       return LHS;
 163     ErrorOr<int64_t> RHS = evaluate(E.RHS);
 164     if (!RHS)
 165       return RHS;
 166     return E.Kind == CounterExpression::Subtract ? *LHS - *RHS : *LHS + *RHS;
 167   }
 168   }
 169   llvm_unreachable("Unhandled CounterKind");
 170 }
 171
 172 void FunctionRecordIterator::skipOtherFiles() {
 173   while (Current != Records.end() && !Filename.empty() &&
 174          Filename != Current->Filenames[0])
 175     ++Current;
 176   if (Current == Records.end())
 177     *this = FunctionRecordIterator();
 178 }
 179
 180 ErrorOr<std::unique_ptr<CoverageMapping>>
 181 CoverageMapping::load(ObjectFileCoverageMappingReader &CoverageReader,
 182                       IndexedInstrProfReader &ProfileReader) {
 183   auto Coverage = std::unique_ptr<CoverageMapping>(new CoverageMapping());
 184
 185   std::vector<uint64_t> Counts;
 186   for (const auto &Record : CoverageReader) {
 187     Counts.clear();
 188     if (std::error_code EC = ProfileReader.getFunctionCounts(
 189             Record.FunctionName, Record.FunctionHash, Counts)) {
 190       if (EC != instrprof_error::hash_mismatch &&
 191           EC != instrprof_error::unknown_function)
 192         return EC;
 193       Coverage->MismatchedFunctionCount++;
 194       continue;
 195     }
 196
 197     assert(Counts.size() != 0 && "Function's counts are empty");
 198     FunctionRecord Function(Record.FunctionName, Record.Filenames,
 199                             Counts.front());
 200     CounterMappingContext Ctx(Record.Expressions, Counts);
 201     for (const auto &Region : Record.MappingRegions) {
 202       ErrorOr<int64_t> ExecutionCount = Ctx.evaluate(Region.Count);
 203       if (!ExecutionCount)
 204         break;
 205       Function.CountedRegions.push_back(CountedRegion(Region, *ExecutionCount));
 206     }
 207     if (Function.CountedRegions.size() != Record.MappingRegions.size()) {
 208       Coverage->MismatchedFunctionCount++;
 209       continue;
 210     }
 211
 212     Coverage->Functions.push_back(std::move(Function));
 213   }
 214
 215   return std::move(Coverage);
 216 }
 217
 218 ErrorOr<std::unique_ptr<CoverageMapping>>
 219 CoverageMapping::load(StringRef ObjectFilename, StringRef ProfileFilename) {
 220   auto CounterMappingBuff = MemoryBuffer::getFileOrSTDIN(ObjectFilename);
 221   if (auto EC = CounterMappingBuff.getError())
 222     return EC;
 223   ObjectFileCoverageMappingReader CoverageReader(CounterMappingBuff.get());
 224   if (auto EC = CoverageReader.readHeader())
 225     return EC;
 226   std::unique_ptr<IndexedInstrProfReader> ProfileReader;
 227   if (auto EC = IndexedInstrProfReader::create(ProfileFilename, ProfileReader))
 228     return EC;
 229   return load(CoverageReader, *ProfileReader);
 230 }
 231
 232 namespace {
 233 /// \brief Distributes functions into instantiation sets.
 234 ///
 235 /// An instantiation set is a collection of functions that have the same source
 236 /// code, ie, template functions specializations.
 237 class FunctionInstantiationSetCollector {
 238   typedef DenseMap<std::pair<unsigned, unsigned>,
 239                    std::vector<const FunctionRecord *>> MapT;
 240   MapT InstantiatedFunctions;
 241
 242 public:
 243   void insert(const FunctionRecord &Function, unsigned FileID) {
 244     auto I = Function.CountedRegions.begin(), E = Function.CountedRegions.end();
 245     while (I != E && I->FileID != FileID)
 246       ++I;
 247     assert(I != E && "function does not cover the given file");
 248     auto &Functions = InstantiatedFunctions[I->startLoc()];
 249     Functions.push_back(&Function);
 250   }
 251
 252   MapT::iterator begin() { return InstantiatedFunctions.begin(); }
 253
 254   MapT::iterator end() { return InstantiatedFunctions.end(); }
 255 };
 256
 257 class SegmentBuilder {
 258   std::vector<CoverageSegment> Segments;
 259   SmallVector<const CountedRegion *, 8> ActiveRegions;
 260
 261   /// Start a segment with no count specified.
 262   void startSegment(unsigned Line, unsigned Col) {
 263     DEBUG(dbgs() << "Top level segment at " << Line << ":" << Col << "\n");
 264     Segments.emplace_back(Line, Col, /*IsRegionEntry=*/false);
 265   }
 266
 267   /// Start a segment with the given Region's count.
 268   void startSegment(unsigned Line, unsigned Col, bool IsRegionEntry,
 269                     const CountedRegion &Region) {
 270     if (Segments.empty())
 271       Segments.emplace_back(Line, Col, IsRegionEntry);
 272     CoverageSegment S = Segments.back();
 273     // Avoid creating empty regions.
 274     if (S.Line != Line || S.Col != Col) {
 275       Segments.emplace_back(Line, Col, IsRegionEntry);
 276       S = Segments.back();
 277     }
 278     DEBUG(dbgs() << "Segment at " << Line << ":" << Col);
 279     // Set this region's count.
 280     if (Region.Kind != coverage::CounterMappingRegion::SkippedRegion) {
 281       DEBUG(dbgs() << " with count " << Region.ExecutionCount);
 282       Segments.back().setCount(Region.ExecutionCount);
 283     }
 284     DEBUG(dbgs() << "\n");
 285   }
 286
 287   /// Start a segment for the given region.
 288   void startSegment(const CountedRegion &Region) {
 289     startSegment(Region.LineStart, Region.ColumnStart, true, Region);
 290   }
 291
 292   /// Pop the top region off of the active stack, starting a new segment with
 293   /// the containing Region's count.
 294   void popRegion() {
 295     const CountedRegion *Active = ActiveRegions.back();
 296     unsigned Line = Active->LineEnd, Col = Active->ColumnEnd;
 297     ActiveRegions.pop_back();
 298     if (ActiveRegions.empty())
 299       startSegment(Line, Col);
 300     else
 301       startSegment(Line, Col, false, *ActiveRegions.back());
 302   }
 303
 304 public:
 305   /// Build a list of CoverageSegments from a sorted list of Regions.
 306   std::vector<CoverageSegment> buildSegments(ArrayRef<CountedRegion> Regions) {
 307     for (const auto &Region : Regions) {
 308       // Pop any regions that end before this one starts.
 309       while (!ActiveRegions.empty() &&
 310              ActiveRegions.back()->endLoc() <= Region.startLoc())
 311         popRegion();
 312       if (Segments.size() && Segments.back().Line == Region.LineStart &&
 313           Segments.back().Col == Region.ColumnStart) {
 314         if (Region.Kind != coverage::CounterMappingRegion::SkippedRegion)
 315           Segments.back().addCount(Region.ExecutionCount);
 316       } else {
 317         // Add this region to the stack.
 318         ActiveRegions.push_back(&Region);
 319         startSegment(Region);
 320       }
 321     }
 322     // Pop any regions that are left in the stack.
 323     while (!ActiveRegions.empty())
 324       popRegion();
 325     return Segments;
 326   }
 327 };
 328 }
 329
 330 std::vector<StringRef> CoverageMapping::getUniqueSourceFiles() const {
 331   std::vector<StringRef> Filenames;
 332   for (const auto &Function : getCoveredFunctions())
 333     for (const auto &Filename : Function.Filenames)
 334       Filenames.push_back(Filename);
 335   std::sort(Filenames.begin(), Filenames.end());
 336   auto Last = std::unique(Filenames.begin(), Filenames.end());
 337   Filenames.erase(Last, Filenames.end());
 338   return Filenames;
 339 }
 340
 341 static Optional<unsigned> findMainViewFileID(StringRef SourceFile,
 342                                              const FunctionRecord &Function) {
 343   llvm::SmallVector<bool, 8> IsExpandedFile(Function.Filenames.size(), false);
 344   llvm::SmallVector<bool, 8> FilenameEquivalence(Function.Filenames.size(),
 345                                                  false);
 346   for (unsigned I = 0, E = Function.Filenames.size(); I < E; ++I)
 347     if (SourceFile == Function.Filenames[I])
 348       FilenameEquivalence[I] = true;
 349   for (const auto &CR : Function.CountedRegions)
 350     if (CR.Kind == CounterMappingRegion::ExpansionRegion &&
 351         FilenameEquivalence[CR.FileID])
 352       IsExpandedFile[CR.ExpandedFileID] = true;
 353   for (unsigned I = 0, E = Function.Filenames.size(); I < E; ++I)
 354     if (FilenameEquivalence[I] && !IsExpandedFile[I])
 355       return I;
 356   return None;
 357 }
 358
 359 static Optional<unsigned> findMainViewFileID(const FunctionRecord &Function) {
 360   llvm::SmallVector<bool, 8> IsExpandedFile(Function.Filenames.size(), false);
 361   for (const auto &CR : Function.CountedRegions)
 362     if (CR.Kind == CounterMappingRegion::ExpansionRegion)
 363       IsExpandedFile[CR.ExpandedFileID] = true;
 364   for (unsigned I = 0, E = Function.Filenames.size(); I < E; ++I)
 365     if (!IsExpandedFile[I])
 366       return I;
 367   return None;
 368 }
 369
 370 static SmallSet<unsigned, 8> gatherFileIDs(StringRef SourceFile,
 371                                            const FunctionRecord &Function) {
 372   SmallSet<unsigned, 8> IDs;
 373   for (unsigned I = 0, E = Function.Filenames.size(); I < E; ++I)
 374     if (SourceFile == Function.Filenames[I])
 375       IDs.insert(I);
 376   return IDs;
 377 }
 378
 379 /// Sort a nested sequence of regions from a single file.
 380 template <class It> static void sortNestedRegions(It First, It Last) {
 381   std::sort(First, Last,
 382             [](const CountedRegion &LHS, const CountedRegion &RHS) {
 383     if (LHS.startLoc() == RHS.startLoc())
 384       // When LHS completely contains RHS, we sort LHS first.
 385       return RHS.endLoc() < LHS.endLoc();
 386     return LHS.startLoc() < RHS.startLoc();
 387   });
 388 }
 389
 390 static bool isExpansion(const CountedRegion &R, unsigned FileID) {
 391   return R.Kind == CounterMappingRegion::ExpansionRegion && R.FileID == FileID;
 392 }
 393
 394 CoverageData CoverageMapping::getCoverageForFile(StringRef Filename) {
 395   CoverageData FileCoverage(Filename);
 396   std::vector<coverage::CountedRegion> Regions;
 397
 398   for (const auto &Function : Functions) {
 399     auto MainFileID = findMainViewFileID(Filename, Function);
 400     if (!MainFileID)
 401       continue;
 402     auto FileIDs = gatherFileIDs(Filename, Function);
 403     for (const auto &CR : Function.CountedRegions)
 404       if (FileIDs.count(CR.FileID)) {
 405         Regions.push_back(CR);
 406         if (isExpansion(CR, *MainFileID))
 407           FileCoverage.Expansions.emplace_back(CR, Function);
 408       }
 409   }
 410
 411   sortNestedRegions(Regions.begin(), Regions.end());
 412   FileCoverage.Segments = SegmentBuilder().buildSegments(Regions);
 413
 414   return FileCoverage;
 415 }
 416
 417 std::vector<const FunctionRecord *>
 418 CoverageMapping::getInstantiations(StringRef Filename) {
 419   FunctionInstantiationSetCollector InstantiationSetCollector;
 420   for (const auto &Function : Functions) {
 421     auto MainFileID = findMainViewFileID(Filename, Function);
 422     if (!MainFileID)
 423       continue;
 424     InstantiationSetCollector.insert(Function, *MainFileID);
 425   }
 426
 427   std::vector<const FunctionRecord *> Result;
 428   for (const auto &InstantiationSet : InstantiationSetCollector) {
 429     if (InstantiationSet.second.size() < 2)
 430       continue;
 431     for (auto Function : InstantiationSet.second)
 432       Result.push_back(Function);
 433   }
 434   return Result;
 435 }
 436
 437 CoverageData
 438 CoverageMapping::getCoverageForFunction(const FunctionRecord &Function) {
 439   auto MainFileID = findMainViewFileID(Function);
 440   if (!MainFileID)
 441     return CoverageData();
 442
 443   CoverageData FunctionCoverage(Function.Filenames[*MainFileID]);
 444   std::vector<coverage::CountedRegion> Regions;
 445   for (const auto &CR : Function.CountedRegions)
 446     if (CR.FileID == *MainFileID) {
 447       Regions.push_back(CR);
 448       if (isExpansion(CR, *MainFileID))
 449         FunctionCoverage.Expansions.emplace_back(CR, Function);
 450     }
 451
 452   sortNestedRegions(Regions.begin(), Regions.end());
 453   FunctionCoverage.Segments = SegmentBuilder().buildSegments(Regions);
 454
 455   return FunctionCoverage;
 456 }
 457
 458 CoverageData
 459 CoverageMapping::getCoverageForExpansion(const ExpansionRecord &Expansion) {
 460   CoverageData ExpansionCoverage(
 461       Expansion.Function.Filenames[Expansion.FileID]);
 462   std::vector<coverage::CountedRegion> Regions;
 463   for (const auto &CR : Expansion.Function.CountedRegions)
 464     if (CR.FileID == Expansion.FileID) {
 465       Regions.push_back(CR);
 466       if (isExpansion(CR, Expansion.FileID))
 467         ExpansionCoverage.Expansions.emplace_back(CR, Expansion.Function);
 468     }
 469
 470   sortNestedRegions(Regions.begin(), Regions.end());
 471   ExpansionCoverage.Segments = SegmentBuilder().buildSegments(Regions);
 472
 473   return ExpansionCoverage;
 474 }