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Diffstat (limited to 'lib/ProfileData/CoverageMappingReader.cpp')
| -rw-r--r-- | lib/ProfileData/CoverageMappingReader.cpp | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/lib/ProfileData/CoverageMappingReader.cpp b/lib/ProfileData/CoverageMappingReader.cpp new file mode 100644 index 0000000..6476d28 --- /dev/null +++ b/lib/ProfileData/CoverageMappingReader.cpp @@ -0,0 +1,553 @@ +//=-- CoverageMappingReader.cpp - Code coverage mapping reader ----*- C++ -*-=// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file contains support for reading coverage mapping data for +// instrumentation based coverage. +// +//===----------------------------------------------------------------------===// + +#include "llvm/ProfileData/CoverageMappingReader.h" +#include "llvm/ADT/DenseSet.h" +#include "llvm/Object/ObjectFile.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/LEB128.h" + +using namespace llvm; +using namespace coverage; +using namespace object; + +#define DEBUG_TYPE "coverage-mapping" + +void CoverageMappingIterator::increment() { + // Check if all the records were read or if an error occurred while reading + // the next record. + if (Reader->readNextRecord(Record)) + *this = CoverageMappingIterator(); +} + +std::error_code RawCoverageReader::readULEB128(uint64_t &Result) { + if (Data.size() < 1) + return error(instrprof_error::truncated); + unsigned N = 0; + Result = decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N); + if (N > Data.size()) + return error(instrprof_error::malformed); + Data = Data.substr(N); + return success(); +} + +std::error_code RawCoverageReader::readIntMax(uint64_t &Result, + uint64_t MaxPlus1) { + if (auto Err = readULEB128(Result)) + return Err; + if (Result >= MaxPlus1) + return error(instrprof_error::malformed); + return success(); +} + +std::error_code RawCoverageReader::readSize(uint64_t &Result) { + if (auto Err = readULEB128(Result)) + return Err; + // Sanity check the number. + if (Result > Data.size()) + return error(instrprof_error::malformed); + return success(); +} + +std::error_code RawCoverageReader::readString(StringRef &Result) { + uint64_t Length; + if (auto Err = readSize(Length)) + return Err; + Result = Data.substr(0, Length); + Data = Data.substr(Length); + return success(); +} + +std::error_code RawCoverageFilenamesReader::read() { + uint64_t NumFilenames; + if (auto Err = readSize(NumFilenames)) + return Err; + for (size_t I = 0; I < NumFilenames; ++I) { + StringRef Filename; + if (auto Err = readString(Filename)) + return Err; + Filenames.push_back(Filename); + } + return success(); +} + +std::error_code RawCoverageMappingReader::decodeCounter(unsigned Value, + Counter &C) { + auto Tag = Value & Counter::EncodingTagMask; + switch (Tag) { + case Counter::Zero: + C = Counter::getZero(); + return success(); + case Counter::CounterValueReference: + C = Counter::getCounter(Value >> Counter::EncodingTagBits); + return success(); + default: + break; + } + Tag -= Counter::Expression; + switch (Tag) { + case CounterExpression::Subtract: + case CounterExpression::Add: { + auto ID = Value >> Counter::EncodingTagBits; + if (ID >= Expressions.size()) + return error(instrprof_error::malformed); + Expressions[ID].Kind = CounterExpression::ExprKind(Tag); + C = Counter::getExpression(ID); + break; + } + default: + return error(instrprof_error::malformed); + } + return success(); +} + +std::error_code RawCoverageMappingReader::readCounter(Counter &C) { + uint64_t EncodedCounter; + if (auto Err = + readIntMax(EncodedCounter, std::numeric_limits<unsigned>::max())) + return Err; + if (auto Err = decodeCounter(EncodedCounter, C)) + return Err; + return success(); +} + +static const unsigned EncodingExpansionRegionBit = 1 + << Counter::EncodingTagBits; + +/// \brief Read the sub-array of regions for the given inferred file id. +/// \param NumFileIDs the number of file ids that are defined for this +/// function. +std::error_code RawCoverageMappingReader::readMappingRegionsSubArray( + std::vector<CounterMappingRegion> &MappingRegions, unsigned InferredFileID, + size_t NumFileIDs) { + uint64_t NumRegions; + if (auto Err = readSize(NumRegions)) + return Err; + unsigned LineStart = 0; + for (size_t I = 0; I < NumRegions; ++I) { + Counter C; + CounterMappingRegion::RegionKind Kind = CounterMappingRegion::CodeRegion; + + // Read the combined counter + region kind. + uint64_t EncodedCounterAndRegion; + if (auto Err = readIntMax(EncodedCounterAndRegion, + std::numeric_limits<unsigned>::max())) + return Err; + unsigned Tag = EncodedCounterAndRegion & Counter::EncodingTagMask; + uint64_t ExpandedFileID = 0; + if (Tag != Counter::Zero) { + if (auto Err = decodeCounter(EncodedCounterAndRegion, C)) + return Err; + } else { + // Is it an expansion region? + if (EncodedCounterAndRegion & EncodingExpansionRegionBit) { + Kind = CounterMappingRegion::ExpansionRegion; + ExpandedFileID = EncodedCounterAndRegion >> + Counter::EncodingCounterTagAndExpansionRegionTagBits; + if (ExpandedFileID >= NumFileIDs) + return error(instrprof_error::malformed); + } else { + switch (EncodedCounterAndRegion >> + Counter::EncodingCounterTagAndExpansionRegionTagBits) { + case CounterMappingRegion::CodeRegion: + // Don't do anything when we have a code region with a zero counter. + break; + case CounterMappingRegion::SkippedRegion: + Kind = CounterMappingRegion::SkippedRegion; + break; + default: + return error(instrprof_error::malformed); + } + } + } + + // Read the source range. + uint64_t LineStartDelta, CodeBeforeColumnStart, NumLines, ColumnEnd; + if (auto Err = + readIntMax(LineStartDelta, std::numeric_limits<unsigned>::max())) + return Err; + if (auto Err = readULEB128(CodeBeforeColumnStart)) + return Err; + bool HasCodeBefore = CodeBeforeColumnStart & 1; + uint64_t ColumnStart = CodeBeforeColumnStart >> + CounterMappingRegion::EncodingHasCodeBeforeBits; + if (ColumnStart > std::numeric_limits<unsigned>::max()) + return error(instrprof_error::malformed); + if (auto Err = readIntMax(NumLines, std::numeric_limits<unsigned>::max())) + return Err; + if (auto Err = readIntMax(ColumnEnd, std::numeric_limits<unsigned>::max())) + return Err; + LineStart += LineStartDelta; + // Adjust the column locations for the empty regions that are supposed to + // cover whole lines. Those regions should be encoded with the + // column range (1 -> std::numeric_limits<unsigned>::max()), but because + // the encoded std::numeric_limits<unsigned>::max() is several bytes long, + // we set the column range to (0 -> 0) to ensure that the column start and + // column end take up one byte each. + // The std::numeric_limits<unsigned>::max() is used to represent a column + // position at the end of the line without knowing the length of that line. + if (ColumnStart == 0 && ColumnEnd == 0) { + ColumnStart = 1; + ColumnEnd = std::numeric_limits<unsigned>::max(); + } + + DEBUG({ + dbgs() << "Counter in file " << InferredFileID << " " << LineStart << ":" + << ColumnStart << " -> " << (LineStart + NumLines) << ":" + << ColumnEnd << ", "; + if (Kind == CounterMappingRegion::ExpansionRegion) + dbgs() << "Expands to file " << ExpandedFileID; + else + CounterMappingContext(Expressions).dump(C, dbgs()); + dbgs() << "\n"; + }); + + MappingRegions.push_back(CounterMappingRegion( + C, InferredFileID, LineStart, ColumnStart, LineStart + NumLines, + ColumnEnd, HasCodeBefore, Kind)); + MappingRegions.back().ExpandedFileID = ExpandedFileID; + } + return success(); +} + +std::error_code RawCoverageMappingReader::read(CoverageMappingRecord &Record) { + + // Read the virtual file mapping. + llvm::SmallVector<unsigned, 8> VirtualFileMapping; + uint64_t NumFileMappings; + if (auto Err = readSize(NumFileMappings)) + return Err; + for (size_t I = 0; I < NumFileMappings; ++I) { + uint64_t FilenameIndex; + if (auto Err = readIntMax(FilenameIndex, TranslationUnitFilenames.size())) + return Err; + VirtualFileMapping.push_back(FilenameIndex); + } + + // Construct the files using unique filenames and virtual file mapping. + for (auto I : VirtualFileMapping) { + Filenames.push_back(TranslationUnitFilenames[I]); + } + + // Read the expressions. + uint64_t NumExpressions; + if (auto Err = readSize(NumExpressions)) + return Err; + // Create an array of dummy expressions that get the proper counters + // when the expressions are read, and the proper kinds when the counters + // are decoded. + Expressions.resize( + NumExpressions, + CounterExpression(CounterExpression::Subtract, Counter(), Counter())); + for (size_t I = 0; I < NumExpressions; ++I) { + if (auto Err = readCounter(Expressions[I].LHS)) + return Err; + if (auto Err = readCounter(Expressions[I].RHS)) + return Err; + } + + // Read the mapping regions sub-arrays. + for (unsigned InferredFileID = 0, S = VirtualFileMapping.size(); + InferredFileID < S; ++InferredFileID) { + if (auto Err = readMappingRegionsSubArray(MappingRegions, InferredFileID, + VirtualFileMapping.size())) + return Err; + } + + // Set the counters for the expansion regions. + // i.e. Counter of expansion region = counter of the first region + // from the expanded file. + // Perform multiple passes to correctly propagate the counters through + // all the nested expansion regions. + SmallVector<CounterMappingRegion *, 8> FileIDExpansionRegionMapping; + FileIDExpansionRegionMapping.resize(VirtualFileMapping.size(), nullptr); + for (unsigned Pass = 1, S = VirtualFileMapping.size(); Pass < S; ++Pass) { + for (auto &R : MappingRegions) { + if (R.Kind != CounterMappingRegion::ExpansionRegion) + continue; + assert(!FileIDExpansionRegionMapping[R.ExpandedFileID]); + FileIDExpansionRegionMapping[R.ExpandedFileID] = &R; + } + for (auto &R : MappingRegions) { + if (FileIDExpansionRegionMapping[R.FileID]) { + FileIDExpansionRegionMapping[R.FileID]->Count = R.Count; + FileIDExpansionRegionMapping[R.FileID] = nullptr; + } + } + } + + Record.FunctionName = FunctionName; + Record.Filenames = Filenames; + Record.Expressions = Expressions; + Record.MappingRegions = MappingRegions; + return success(); +} + +ObjectFileCoverageMappingReader::ObjectFileCoverageMappingReader( + StringRef FileName) + : CurrentRecord(0) { + auto File = llvm::object::ObjectFile::createObjectFile(FileName); + if (!File) + error(File.getError()); + else + Object = std::move(File.get()); +} + +namespace { +/// \brief The coverage mapping data for a single function. +/// It points to the function's name. +template <typename IntPtrT> struct CoverageMappingFunctionRecord { + IntPtrT FunctionNamePtr; + uint32_t FunctionNameSize; + uint32_t CoverageMappingSize; + uint64_t FunctionHash; +}; + +/// \brief The coverage mapping data for a single translation unit. +/// It points to the array of function coverage mapping records and the encoded +/// filenames array. +template <typename IntPtrT> struct CoverageMappingTURecord { + uint32_t FunctionRecordsSize; + uint32_t FilenamesSize; + uint32_t CoverageMappingsSize; + uint32_t Version; +}; + +/// \brief A helper structure to access the data from a section +/// in an object file. +struct SectionData { + StringRef Data; + uint64_t Address; + + std::error_code load(SectionRef &Section) { + if (auto Err = Section.getContents(Data)) + return Err; + Address = Section.getAddress(); + return instrprof_error::success; + } + + std::error_code get(uint64_t Pointer, size_t Size, StringRef &Result) { + if (Pointer < Address) + return instrprof_error::malformed; + auto Offset = Pointer - Address; + if (Offset + Size > Data.size()) + return instrprof_error::malformed; + Result = Data.substr(Pointer - Address, Size); + return instrprof_error::success; + } +}; +} + +template <typename T> +std::error_code readCoverageMappingData( + SectionData &ProfileNames, StringRef Data, + std::vector<ObjectFileCoverageMappingReader::ProfileMappingRecord> &Records, + std::vector<StringRef> &Filenames) { + llvm::DenseSet<T> UniqueFunctionMappingData; + + // Read the records in the coverage data section. + while (!Data.empty()) { + if (Data.size() < sizeof(CoverageMappingTURecord<T>)) + return instrprof_error::malformed; + auto TU = reinterpret_cast<const CoverageMappingTURecord<T> *>(Data.data()); + Data = Data.substr(sizeof(CoverageMappingTURecord<T>)); + switch (TU->Version) { + case CoverageMappingVersion1: + break; + default: + return instrprof_error::unsupported_version; + } + auto Version = CoverageMappingVersion(TU->Version); + + // Get the function records. + auto FunctionRecords = + reinterpret_cast<const CoverageMappingFunctionRecord<T> *>(Data.data()); + if (Data.size() < + sizeof(CoverageMappingFunctionRecord<T>) * TU->FunctionRecordsSize) + return instrprof_error::malformed; + Data = Data.substr(sizeof(CoverageMappingFunctionRecord<T>) * + TU->FunctionRecordsSize); + + // Get the filenames. + if (Data.size() < TU->FilenamesSize) + return instrprof_error::malformed; + auto RawFilenames = Data.substr(0, TU->FilenamesSize); + Data = Data.substr(TU->FilenamesSize); + size_t FilenamesBegin = Filenames.size(); + RawCoverageFilenamesReader Reader(RawFilenames, Filenames); + if (auto Err = Reader.read()) + return Err; + + // Get the coverage mappings. + if (Data.size() < TU->CoverageMappingsSize) + return instrprof_error::malformed; + auto CoverageMappings = Data.substr(0, TU->CoverageMappingsSize); + Data = Data.substr(TU->CoverageMappingsSize); + + for (unsigned I = 0; I < TU->FunctionRecordsSize; ++I) { + auto &MappingRecord = FunctionRecords[I]; + + // Get the coverage mapping. + if (CoverageMappings.size() < MappingRecord.CoverageMappingSize) + return instrprof_error::malformed; + auto Mapping = + CoverageMappings.substr(0, MappingRecord.CoverageMappingSize); + CoverageMappings = + CoverageMappings.substr(MappingRecord.CoverageMappingSize); + + // Ignore this record if we already have a record that points to the same + // function name. + // This is useful to ignore the redundant records for the functions + // with ODR linkage. + if (!UniqueFunctionMappingData.insert(MappingRecord.FunctionNamePtr) + .second) + continue; + StringRef FunctionName; + if (auto Err = + ProfileNames.get(MappingRecord.FunctionNamePtr, + MappingRecord.FunctionNameSize, FunctionName)) + return Err; + Records.push_back(ObjectFileCoverageMappingReader::ProfileMappingRecord( + Version, FunctionName, MappingRecord.FunctionHash, Mapping, + FilenamesBegin, Filenames.size() - FilenamesBegin)); + } + } + + return instrprof_error::success; +} + +static const char *TestingFormatMagic = "llvmcovmtestdata"; + +static std::error_code decodeTestingFormat(StringRef Data, + SectionData &ProfileNames, + StringRef &CoverageMapping) { + Data = Data.substr(StringRef(TestingFormatMagic).size()); + if (Data.size() < 1) + return instrprof_error::truncated; + unsigned N = 0; + auto ProfileNamesSize = + decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N); + if (N > Data.size()) + return instrprof_error::malformed; + Data = Data.substr(N); + if (Data.size() < 1) + return instrprof_error::truncated; + N = 0; + ProfileNames.Address = + decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N); + if (N > Data.size()) + return instrprof_error::malformed; + Data = Data.substr(N); + if (Data.size() < ProfileNamesSize) + return instrprof_error::malformed; + ProfileNames.Data = Data.substr(0, ProfileNamesSize); + CoverageMapping = Data.substr(ProfileNamesSize); + return instrprof_error::success; +} + +ObjectFileCoverageMappingReader::ObjectFileCoverageMappingReader( + std::unique_ptr<MemoryBuffer> &ObjectBuffer, sys::fs::file_magic Type) + : CurrentRecord(0) { + if (ObjectBuffer->getBuffer().startswith(TestingFormatMagic)) { + // This is a special format used for testing. + SectionData ProfileNames; + StringRef CoverageMapping; + if (auto Err = decodeTestingFormat(ObjectBuffer->getBuffer(), ProfileNames, + CoverageMapping)) { + error(Err); + return; + } + error(readCoverageMappingData<uint64_t>(ProfileNames, CoverageMapping, + MappingRecords, Filenames)); + Object = OwningBinary<ObjectFile>(std::unique_ptr<ObjectFile>(), + std::move(ObjectBuffer)); + return; + } + + auto File = object::ObjectFile::createObjectFile( + ObjectBuffer->getMemBufferRef(), Type); + if (!File) + error(File.getError()); + else + Object = OwningBinary<ObjectFile>(std::move(File.get()), + std::move(ObjectBuffer)); +} + +std::error_code ObjectFileCoverageMappingReader::readHeader() { + const ObjectFile *OF = Object.getBinary(); + if (!OF) + return getError(); + auto BytesInAddress = OF->getBytesInAddress(); + if (BytesInAddress != 4 && BytesInAddress != 8) + return error(instrprof_error::malformed); + + // Look for the sections that we are interested in. + int FoundSectionCount = 0; + SectionRef ProfileNames, CoverageMapping; + for (const auto &Section : OF->sections()) { + StringRef Name; + if (auto Err = Section.getName(Name)) + return Err; + if (Name == "__llvm_prf_names") { + ProfileNames = Section; + } else if (Name == "__llvm_covmap") { + CoverageMapping = Section; + } else + continue; + ++FoundSectionCount; + } + if (FoundSectionCount != 2) + return error(instrprof_error::bad_header); + + // Get the contents of the given sections. + StringRef Data; + if (auto Err = CoverageMapping.getContents(Data)) + return Err; + SectionData ProfileNamesData; + if (auto Err = ProfileNamesData.load(ProfileNames)) + return Err; + + // Load the data from the found sections. + std::error_code Err; + if (BytesInAddress == 4) + Err = readCoverageMappingData<uint32_t>(ProfileNamesData, Data, + MappingRecords, Filenames); + else + Err = readCoverageMappingData<uint64_t>(ProfileNamesData, Data, + MappingRecords, Filenames); + if (Err) + return error(Err); + + return success(); +} + +std::error_code +ObjectFileCoverageMappingReader::readNextRecord(CoverageMappingRecord &Record) { + if (CurrentRecord >= MappingRecords.size()) + return error(instrprof_error::eof); + + FunctionsFilenames.clear(); + Expressions.clear(); + MappingRegions.clear(); + auto &R = MappingRecords[CurrentRecord]; + RawCoverageMappingReader Reader( + R.FunctionName, R.CoverageMapping, + makeArrayRef(Filenames.data() + R.FilenamesBegin, R.FilenamesSize), + FunctionsFilenames, Expressions, MappingRegions); + if (auto Err = Reader.read(Record)) + return Err; + Record.FunctionHash = R.FunctionHash; + ++CurrentRecord; + return success(); +} |