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/SmallBitVector.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 #include "llvm/Support/raw_ostream.h"
24
25 using namespace llvm;
26 using namespace coverage;
27
28 #define DEBUG_TYPE "coverage-mapping"
29
get(const CounterExpression & E)30 Counter CounterExpressionBuilder::get(const CounterExpression &E) {
31 auto It = ExpressionIndices.find(E);
32 if (It != ExpressionIndices.end())
33 return Counter::getExpression(It->second);
34 unsigned I = Expressions.size();
35 Expressions.push_back(E);
36 ExpressionIndices[E] = I;
37 return Counter::getExpression(I);
38 }
39
extractTerms(Counter C,int Sign,SmallVectorImpl<std::pair<unsigned,int>> & Terms)40 void CounterExpressionBuilder::extractTerms(
41 Counter C, int Sign, SmallVectorImpl<std::pair<unsigned, int>> &Terms) {
42 switch (C.getKind()) {
43 case Counter::Zero:
44 break;
45 case Counter::CounterValueReference:
46 Terms.push_back(std::make_pair(C.getCounterID(), Sign));
47 break;
48 case Counter::Expression:
49 const auto &E = Expressions[C.getExpressionID()];
50 extractTerms(E.LHS, Sign, Terms);
51 extractTerms(E.RHS, E.Kind == CounterExpression::Subtract ? -Sign : Sign,
52 Terms);
53 break;
54 }
55 }
56
simplify(Counter ExpressionTree)57 Counter CounterExpressionBuilder::simplify(Counter ExpressionTree) {
58 // Gather constant terms.
59 llvm::SmallVector<std::pair<unsigned, int>, 32> Terms;
60 extractTerms(ExpressionTree, +1, Terms);
61
62 // If there are no terms, this is just a zero. The algorithm below assumes at
63 // least one term.
64 if (Terms.size() == 0)
65 return Counter::getZero();
66
67 // Group the terms by counter ID.
68 std::sort(Terms.begin(), Terms.end(),
69 [](const std::pair<unsigned, int> &LHS,
70 const std::pair<unsigned, int> &RHS) {
71 return LHS.first < RHS.first;
72 });
73
74 // Combine terms by counter ID to eliminate counters that sum to zero.
75 auto Prev = Terms.begin();
76 for (auto I = Prev + 1, E = Terms.end(); I != E; ++I) {
77 if (I->first == Prev->first) {
78 Prev->second += I->second;
79 continue;
80 }
81 ++Prev;
82 *Prev = *I;
83 }
84 Terms.erase(++Prev, Terms.end());
85
86 Counter C;
87 // Create additions. We do this before subtractions to avoid constructs like
88 // ((0 - X) + Y), as opposed to (Y - X).
89 for (auto Term : Terms) {
90 if (Term.second <= 0)
91 continue;
92 for (int I = 0; I < Term.second; ++I)
93 if (C.isZero())
94 C = Counter::getCounter(Term.first);
95 else
96 C = get(CounterExpression(CounterExpression::Add, C,
97 Counter::getCounter(Term.first)));
98 }
99
100 // Create subtractions.
101 for (auto Term : Terms) {
102 if (Term.second >= 0)
103 continue;
104 for (int I = 0; I < -Term.second; ++I)
105 C = get(CounterExpression(CounterExpression::Subtract, C,
106 Counter::getCounter(Term.first)));
107 }
108 return C;
109 }
110
add(Counter LHS,Counter RHS)111 Counter CounterExpressionBuilder::add(Counter LHS, Counter RHS) {
112 return simplify(get(CounterExpression(CounterExpression::Add, LHS, RHS)));
113 }
114
subtract(Counter LHS,Counter RHS)115 Counter CounterExpressionBuilder::subtract(Counter LHS, Counter RHS) {
116 return simplify(
117 get(CounterExpression(CounterExpression::Subtract, LHS, RHS)));
118 }
119
dump(const Counter & C,llvm::raw_ostream & OS) const120 void CounterMappingContext::dump(const Counter &C,
121 llvm::raw_ostream &OS) const {
122 switch (C.getKind()) {
123 case Counter::Zero:
124 OS << '0';
125 return;
126 case Counter::CounterValueReference:
127 OS << '#' << C.getCounterID();
128 break;
129 case Counter::Expression: {
130 if (C.getExpressionID() >= Expressions.size())
131 return;
132 const auto &E = Expressions[C.getExpressionID()];
133 OS << '(';
134 dump(E.LHS, OS);
135 OS << (E.Kind == CounterExpression::Subtract ? " - " : " + ");
136 dump(E.RHS, OS);
137 OS << ')';
138 break;
139 }
140 }
141 if (CounterValues.empty())
142 return;
143 ErrorOr<int64_t> Value = evaluate(C);
144 if (!Value)
145 return;
146 OS << '[' << *Value << ']';
147 }
148
evaluate(const Counter & C) const149 ErrorOr<int64_t> CounterMappingContext::evaluate(const Counter &C) const {
150 switch (C.getKind()) {
151 case Counter::Zero:
152 return 0;
153 case Counter::CounterValueReference:
154 if (C.getCounterID() >= CounterValues.size())
155 return std::make_error_code(std::errc::argument_out_of_domain);
156 return CounterValues[C.getCounterID()];
157 case Counter::Expression: {
158 if (C.getExpressionID() >= Expressions.size())
159 return std::make_error_code(std::errc::argument_out_of_domain);
160 const auto &E = Expressions[C.getExpressionID()];
161 ErrorOr<int64_t> LHS = evaluate(E.LHS);
162 if (!LHS)
163 return LHS;
164 ErrorOr<int64_t> RHS = evaluate(E.RHS);
165 if (!RHS)
166 return RHS;
167 return E.Kind == CounterExpression::Subtract ? *LHS - *RHS : *LHS + *RHS;
168 }
169 }
170 llvm_unreachable("Unhandled CounterKind");
171 }
172
skipOtherFiles()173 void FunctionRecordIterator::skipOtherFiles() {
174 while (Current != Records.end() && !Filename.empty() &&
175 Filename != Current->Filenames[0])
176 ++Current;
177 if (Current == Records.end())
178 *this = FunctionRecordIterator();
179 }
180
181 ErrorOr<std::unique_ptr<CoverageMapping>>
load(CoverageMappingReader & CoverageReader,IndexedInstrProfReader & ProfileReader)182 CoverageMapping::load(CoverageMappingReader &CoverageReader,
183 IndexedInstrProfReader &ProfileReader) {
184 auto Coverage = std::unique_ptr<CoverageMapping>(new CoverageMapping());
185
186 std::vector<uint64_t> Counts;
187 for (const auto &Record : CoverageReader) {
188 CounterMappingContext Ctx(Record.Expressions);
189
190 Counts.clear();
191 if (std::error_code EC = ProfileReader.getFunctionCounts(
192 Record.FunctionName, Record.FunctionHash, Counts)) {
193 if (EC == instrprof_error::hash_mismatch) {
194 Coverage->MismatchedFunctionCount++;
195 continue;
196 } else if (EC != instrprof_error::unknown_function)
197 return EC;
198 } else
199 Ctx.setCounts(Counts);
200
201 assert(!Record.MappingRegions.empty() && "Function has no regions");
202 FunctionRecord Function(Record.FunctionName, Record.Filenames);
203 for (const auto &Region : Record.MappingRegions) {
204 ErrorOr<int64_t> ExecutionCount = Ctx.evaluate(Region.Count);
205 if (!ExecutionCount)
206 break;
207 Function.pushRegion(Region, *ExecutionCount);
208 }
209 if (Function.CountedRegions.size() != Record.MappingRegions.size()) {
210 Coverage->MismatchedFunctionCount++;
211 continue;
212 }
213
214 Coverage->Functions.push_back(std::move(Function));
215 }
216
217 return std::move(Coverage);
218 }
219
220 ErrorOr<std::unique_ptr<CoverageMapping>>
load(StringRef ObjectFilename,StringRef ProfileFilename,Triple::ArchType Arch)221 CoverageMapping::load(StringRef ObjectFilename, StringRef ProfileFilename,
222 Triple::ArchType Arch) {
223 auto CounterMappingBuff = MemoryBuffer::getFileOrSTDIN(ObjectFilename);
224 if (std::error_code EC = CounterMappingBuff.getError())
225 return EC;
226 auto CoverageReaderOrErr =
227 BinaryCoverageReader::create(CounterMappingBuff.get(), Arch);
228 if (std::error_code EC = CoverageReaderOrErr.getError())
229 return EC;
230 auto CoverageReader = std::move(CoverageReaderOrErr.get());
231 auto ProfileReaderOrErr = IndexedInstrProfReader::create(ProfileFilename);
232 if (auto EC = ProfileReaderOrErr.getError())
233 return EC;
234 auto ProfileReader = std::move(ProfileReaderOrErr.get());
235 return load(*CoverageReader, *ProfileReader);
236 }
237
238 namespace {
239 /// \brief Distributes functions into instantiation sets.
240 ///
241 /// An instantiation set is a collection of functions that have the same source
242 /// code, ie, template functions specializations.
243 class FunctionInstantiationSetCollector {
244 typedef DenseMap<std::pair<unsigned, unsigned>,
245 std::vector<const FunctionRecord *>> MapT;
246 MapT InstantiatedFunctions;
247
248 public:
insert(const FunctionRecord & Function,unsigned FileID)249 void insert(const FunctionRecord &Function, unsigned FileID) {
250 auto I = Function.CountedRegions.begin(), E = Function.CountedRegions.end();
251 while (I != E && I->FileID != FileID)
252 ++I;
253 assert(I != E && "function does not cover the given file");
254 auto &Functions = InstantiatedFunctions[I->startLoc()];
255 Functions.push_back(&Function);
256 }
257
begin()258 MapT::iterator begin() { return InstantiatedFunctions.begin(); }
259
end()260 MapT::iterator end() { return InstantiatedFunctions.end(); }
261 };
262
263 class SegmentBuilder {
264 std::vector<CoverageSegment> Segments;
265 SmallVector<const CountedRegion *, 8> ActiveRegions;
266
267 /// Start a segment with no count specified.
startSegment(unsigned Line,unsigned Col)268 void startSegment(unsigned Line, unsigned Col) {
269 DEBUG(dbgs() << "Top level segment at " << Line << ":" << Col << "\n");
270 Segments.emplace_back(Line, Col, /*IsRegionEntry=*/false);
271 }
272
273 /// Start a segment with the given Region's count.
startSegment(unsigned Line,unsigned Col,bool IsRegionEntry,const CountedRegion & Region)274 void startSegment(unsigned Line, unsigned Col, bool IsRegionEntry,
275 const CountedRegion &Region) {
276 if (Segments.empty())
277 Segments.emplace_back(Line, Col, IsRegionEntry);
278 CoverageSegment S = Segments.back();
279 // Avoid creating empty regions.
280 if (S.Line != Line || S.Col != Col) {
281 Segments.emplace_back(Line, Col, IsRegionEntry);
282 S = Segments.back();
283 }
284 DEBUG(dbgs() << "Segment at " << Line << ":" << Col);
285 // Set this region's count.
286 if (Region.Kind != coverage::CounterMappingRegion::SkippedRegion) {
287 DEBUG(dbgs() << " with count " << Region.ExecutionCount);
288 Segments.back().setCount(Region.ExecutionCount);
289 }
290 DEBUG(dbgs() << "\n");
291 }
292
293 /// Start a segment for the given region.
startSegment(const CountedRegion & Region)294 void startSegment(const CountedRegion &Region) {
295 startSegment(Region.LineStart, Region.ColumnStart, true, Region);
296 }
297
298 /// Pop the top region off of the active stack, starting a new segment with
299 /// the containing Region's count.
popRegion()300 void popRegion() {
301 const CountedRegion *Active = ActiveRegions.back();
302 unsigned Line = Active->LineEnd, Col = Active->ColumnEnd;
303 ActiveRegions.pop_back();
304 if (ActiveRegions.empty())
305 startSegment(Line, Col);
306 else
307 startSegment(Line, Col, false, *ActiveRegions.back());
308 }
309
310 public:
311 /// Build a list of CoverageSegments from a sorted list of Regions.
buildSegments(ArrayRef<CountedRegion> Regions)312 std::vector<CoverageSegment> buildSegments(ArrayRef<CountedRegion> Regions) {
313 const CountedRegion *PrevRegion = nullptr;
314 for (const auto &Region : Regions) {
315 // Pop any regions that end before this one starts.
316 while (!ActiveRegions.empty() &&
317 ActiveRegions.back()->endLoc() <= Region.startLoc())
318 popRegion();
319 if (PrevRegion && PrevRegion->startLoc() == Region.startLoc() &&
320 PrevRegion->endLoc() == Region.endLoc()) {
321 if (Region.Kind == coverage::CounterMappingRegion::CodeRegion)
322 Segments.back().addCount(Region.ExecutionCount);
323 } else {
324 // Add this region to the stack.
325 ActiveRegions.push_back(&Region);
326 startSegment(Region);
327 }
328 PrevRegion = &Region;
329 }
330 // Pop any regions that are left in the stack.
331 while (!ActiveRegions.empty())
332 popRegion();
333 return Segments;
334 }
335 };
336 }
337
getUniqueSourceFiles() const338 std::vector<StringRef> CoverageMapping::getUniqueSourceFiles() const {
339 std::vector<StringRef> Filenames;
340 for (const auto &Function : getCoveredFunctions())
341 Filenames.insert(Filenames.end(), Function.Filenames.begin(),
342 Function.Filenames.end());
343 std::sort(Filenames.begin(), Filenames.end());
344 auto Last = std::unique(Filenames.begin(), Filenames.end());
345 Filenames.erase(Last, Filenames.end());
346 return Filenames;
347 }
348
gatherFileIDs(StringRef SourceFile,const FunctionRecord & Function)349 static SmallBitVector gatherFileIDs(StringRef SourceFile,
350 const FunctionRecord &Function) {
351 SmallBitVector FilenameEquivalence(Function.Filenames.size(), false);
352 for (unsigned I = 0, E = Function.Filenames.size(); I < E; ++I)
353 if (SourceFile == Function.Filenames[I])
354 FilenameEquivalence[I] = true;
355 return FilenameEquivalence;
356 }
357
findMainViewFileID(StringRef SourceFile,const FunctionRecord & Function)358 static Optional<unsigned> findMainViewFileID(StringRef SourceFile,
359 const FunctionRecord &Function) {
360 SmallBitVector IsNotExpandedFile(Function.Filenames.size(), true);
361 SmallBitVector FilenameEquivalence = gatherFileIDs(SourceFile, Function);
362 for (const auto &CR : Function.CountedRegions)
363 if (CR.Kind == CounterMappingRegion::ExpansionRegion &&
364 FilenameEquivalence[CR.FileID])
365 IsNotExpandedFile[CR.ExpandedFileID] = false;
366 IsNotExpandedFile &= FilenameEquivalence;
367 int I = IsNotExpandedFile.find_first();
368 if (I == -1)
369 return None;
370 return I;
371 }
372
findMainViewFileID(const FunctionRecord & Function)373 static Optional<unsigned> findMainViewFileID(const FunctionRecord &Function) {
374 SmallBitVector IsNotExpandedFile(Function.Filenames.size(), true);
375 for (const auto &CR : Function.CountedRegions)
376 if (CR.Kind == CounterMappingRegion::ExpansionRegion)
377 IsNotExpandedFile[CR.ExpandedFileID] = false;
378 int I = IsNotExpandedFile.find_first();
379 if (I == -1)
380 return None;
381 return I;
382 }
383
384 /// Sort a nested sequence of regions from a single file.
sortNestedRegions(It First,It Last)385 template <class It> static void sortNestedRegions(It First, It Last) {
386 std::sort(First, Last,
387 [](const CountedRegion &LHS, const CountedRegion &RHS) {
388 if (LHS.startLoc() == RHS.startLoc())
389 // When LHS completely contains RHS, we sort LHS first.
390 return RHS.endLoc() < LHS.endLoc();
391 return LHS.startLoc() < RHS.startLoc();
392 });
393 }
394
isExpansion(const CountedRegion & R,unsigned FileID)395 static bool isExpansion(const CountedRegion &R, unsigned FileID) {
396 return R.Kind == CounterMappingRegion::ExpansionRegion && R.FileID == FileID;
397 }
398
getCoverageForFile(StringRef Filename)399 CoverageData CoverageMapping::getCoverageForFile(StringRef Filename) {
400 CoverageData FileCoverage(Filename);
401 std::vector<coverage::CountedRegion> Regions;
402
403 for (const auto &Function : Functions) {
404 auto MainFileID = findMainViewFileID(Filename, Function);
405 if (!MainFileID)
406 continue;
407 auto FileIDs = gatherFileIDs(Filename, Function);
408 for (const auto &CR : Function.CountedRegions)
409 if (FileIDs.test(CR.FileID)) {
410 Regions.push_back(CR);
411 if (isExpansion(CR, *MainFileID))
412 FileCoverage.Expansions.emplace_back(CR, Function);
413 }
414 }
415
416 sortNestedRegions(Regions.begin(), Regions.end());
417 DEBUG(dbgs() << "Emitting segments for file: " << Filename << "\n");
418 FileCoverage.Segments = SegmentBuilder().buildSegments(Regions);
419
420 return FileCoverage;
421 }
422
423 std::vector<const FunctionRecord *>
getInstantiations(StringRef Filename)424 CoverageMapping::getInstantiations(StringRef Filename) {
425 FunctionInstantiationSetCollector InstantiationSetCollector;
426 for (const auto &Function : Functions) {
427 auto MainFileID = findMainViewFileID(Filename, Function);
428 if (!MainFileID)
429 continue;
430 InstantiationSetCollector.insert(Function, *MainFileID);
431 }
432
433 std::vector<const FunctionRecord *> Result;
434 for (const auto &InstantiationSet : InstantiationSetCollector) {
435 if (InstantiationSet.second.size() < 2)
436 continue;
437 Result.insert(Result.end(), InstantiationSet.second.begin(),
438 InstantiationSet.second.end());
439 }
440 return Result;
441 }
442
443 CoverageData
getCoverageForFunction(const FunctionRecord & Function)444 CoverageMapping::getCoverageForFunction(const FunctionRecord &Function) {
445 auto MainFileID = findMainViewFileID(Function);
446 if (!MainFileID)
447 return CoverageData();
448
449 CoverageData FunctionCoverage(Function.Filenames[*MainFileID]);
450 std::vector<coverage::CountedRegion> Regions;
451 for (const auto &CR : Function.CountedRegions)
452 if (CR.FileID == *MainFileID) {
453 Regions.push_back(CR);
454 if (isExpansion(CR, *MainFileID))
455 FunctionCoverage.Expansions.emplace_back(CR, Function);
456 }
457
458 sortNestedRegions(Regions.begin(), Regions.end());
459 DEBUG(dbgs() << "Emitting segments for function: " << Function.Name << "\n");
460 FunctionCoverage.Segments = SegmentBuilder().buildSegments(Regions);
461
462 return FunctionCoverage;
463 }
464
465 CoverageData
getCoverageForExpansion(const ExpansionRecord & Expansion)466 CoverageMapping::getCoverageForExpansion(const ExpansionRecord &Expansion) {
467 CoverageData ExpansionCoverage(
468 Expansion.Function.Filenames[Expansion.FileID]);
469 std::vector<coverage::CountedRegion> Regions;
470 for (const auto &CR : Expansion.Function.CountedRegions)
471 if (CR.FileID == Expansion.FileID) {
472 Regions.push_back(CR);
473 if (isExpansion(CR, Expansion.FileID))
474 ExpansionCoverage.Expansions.emplace_back(CR, Expansion.Function);
475 }
476
477 sortNestedRegions(Regions.begin(), Regions.end());
478 DEBUG(dbgs() << "Emitting segments for expansion of file " << Expansion.FileID
479 << "\n");
480 ExpansionCoverage.Segments = SegmentBuilder().buildSegments(Regions);
481
482 return ExpansionCoverage;
483 }
484