llvm-6502/lib/ProfileData/CoverageMappingReader.cpp
Lang Hames 7b8ba81502 [Object] Modify OwningBinary's interface to separate inspection from ownership.
The getBinary and getBuffer method now return ordinary pointers of appropriate
const-ness. Ownership is transferred by calling takeBinary(), which returns a
pair of the Binary and a MemoryBuffer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221003 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-31 21:37:49 +00:00

554 lines
19 KiB
C++

//=-- 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();
}