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//===- InstrProfReader.h - Instrumented profiling readers -------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file contains support for reading profiling data for instrumentation
// based PGO and coverage.
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/ProfileSummary.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/LineIterator.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/OnDiskHashTable.h"
#include "llvm/Support/SwapByteOrder.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <iterator>
#include <memory>
#include <utility>
#include <vector>
namespace llvm {
class InstrProfReader;
/// A file format agnostic iterator over profiling data.
class InstrProfIterator : public std::iterator<std::input_iterator_tag,
NamedInstrProfRecord> {
InstrProfReader *Reader = nullptr;
value_type Record;
void Increment();
InstrProfIterator() = default;
InstrProfIterator(InstrProfReader *Reader) : Reader(Reader) { Increment(); }
InstrProfIterator &operator++() { Increment(); return *this; }
bool operator==(const InstrProfIterator &RHS) { return Reader == RHS.Reader; }
bool operator!=(const InstrProfIterator &RHS) { return Reader != RHS.Reader; }
value_type &operator*() { return Record; }
value_type *operator->() { return &Record; }
/// Base class and interface for reading profiling data of any known instrprof
/// format. Provides an iterator over NamedInstrProfRecords.
class InstrProfReader {
instrprof_error LastError = instrprof_error::success;
InstrProfReader() = default;
virtual ~InstrProfReader() = default;
/// Read the header. Required before reading first record.
virtual Error readHeader() = 0;
/// Read a single record.
virtual Error readNextRecord(NamedInstrProfRecord &Record) = 0;
/// Iterator over profile data.
InstrProfIterator begin() { return InstrProfIterator(this); }
InstrProfIterator end() { return InstrProfIterator(); }
virtual bool isIRLevelProfile() const = 0;
/// Return the PGO symtab. There are three different readers:
/// Raw, Text, and Indexed profile readers. The first two types
/// of readers are used only by llvm-profdata tool, while the indexed
/// profile reader is also used by llvm-cov tool and the compiler (
/// backend or frontend). Since creating PGO symtab can create
/// significant runtime and memory overhead (as it touches data
/// for the whole program), InstrProfSymtab for the indexed profile
/// reader should be created on demand and it is recommended to be
/// only used for dumping purpose with llvm-proftool, not with the
/// compiler.
virtual InstrProfSymtab &getSymtab() = 0;
std::unique_ptr<InstrProfSymtab> Symtab;
/// Set the current error and return same.
Error error(instrprof_error Err) {
LastError = Err;
if (Err == instrprof_error::success)
return Error::success();
return make_error<InstrProfError>(Err);
Error error(Error &&E) { return error(InstrProfError::take(std::move(E))); }
/// Clear the current error and return a successful one.
Error success() { return error(instrprof_error::success); }
/// Return true if the reader has finished reading the profile data.
bool isEOF() { return LastError == instrprof_error::eof; }
/// Return true if the reader encountered an error reading profiling data.
bool hasError() { return LastError != instrprof_error::success && !isEOF(); }
/// Get the current error.
Error getError() {
if (hasError())
return make_error<InstrProfError>(LastError);
return Error::success();
/// Factory method to create an appropriately typed reader for the given
/// instrprof file.
static Expected<std::unique_ptr<InstrProfReader>> create(const Twine &Path);
static Expected<std::unique_ptr<InstrProfReader>>
create(std::unique_ptr<MemoryBuffer> Buffer);
/// Reader for the simple text based instrprof format.
/// This format is a simple text format that's suitable for test data. Records
/// are separated by one or more blank lines, and record fields are separated by
/// new lines.
/// Each record consists of a function name, a function hash, a number of
/// counters, and then each counter value, in that order.
class TextInstrProfReader : public InstrProfReader {
/// The profile data file contents.
std::unique_ptr<MemoryBuffer> DataBuffer;
/// Iterator over the profile data.
line_iterator Line;
bool IsIRLevelProfile = false;
Error readValueProfileData(InstrProfRecord &Record);
TextInstrProfReader(std::unique_ptr<MemoryBuffer> DataBuffer_)
: DataBuffer(std::move(DataBuffer_)), Line(*DataBuffer, true, '#') {}
TextInstrProfReader(const TextInstrProfReader &) = delete;
TextInstrProfReader &operator=(const TextInstrProfReader &) = delete;
/// Return true if the given buffer is in text instrprof format.
static bool hasFormat(const MemoryBuffer &Buffer);
bool isIRLevelProfile() const override { return IsIRLevelProfile; }
/// Read the header.
Error readHeader() override;
/// Read a single record.
Error readNextRecord(NamedInstrProfRecord &Record) override;
InstrProfSymtab &getSymtab() override {
return *Symtab.get();
/// Reader for the raw instrprof binary format from runtime.
/// This format is a raw memory dump of the instrumentation-baed profiling data
/// from the runtime. It has no index.
/// Templated on the unsigned type whose size matches pointers on the platform
/// that wrote the profile.
template <class IntPtrT>
class RawInstrProfReader : public InstrProfReader {
/// The profile data file contents.
std::unique_ptr<MemoryBuffer> DataBuffer;
bool ShouldSwapBytes;
// The value of the version field of the raw profile data header. The lower 56
// bits specifies the format version and the most significant 8 bits specify
// the variant types of the profile.
uint64_t Version;
uint64_t CountersDelta;
uint64_t NamesDelta;
const RawInstrProf::ProfileData<IntPtrT> *Data;
const RawInstrProf::ProfileData<IntPtrT> *DataEnd;
const uint64_t *CountersStart;
const char *NamesStart;
uint64_t NamesSize;
// After value profile is all read, this pointer points to
// the header of next profile data (if exists)
const uint8_t *ValueDataStart;
uint32_t ValueKindLast;
uint32_t CurValueDataSize;
RawInstrProfReader(std::unique_ptr<MemoryBuffer> DataBuffer)
: DataBuffer(std::move(DataBuffer)) {}
RawInstrProfReader(const RawInstrProfReader &) = delete;
RawInstrProfReader &operator=(const RawInstrProfReader &) = delete;
static bool hasFormat(const MemoryBuffer &DataBuffer);
Error readHeader() override;
Error readNextRecord(NamedInstrProfRecord &Record) override;
bool isIRLevelProfile() const override {
return (Version & VARIANT_MASK_IR_PROF) != 0;
InstrProfSymtab &getSymtab() override {
return *Symtab.get();
Error createSymtab(InstrProfSymtab &Symtab);
Error readNextHeader(const char *CurrentPos);
Error readHeader(const RawInstrProf::Header &Header);
template <class IntT> IntT swap(IntT Int) const {
return ShouldSwapBytes ? sys::getSwappedBytes(Int) : Int;
support::endianness getDataEndianness() const {
support::endianness HostEndian = getHostEndianness();
if (!ShouldSwapBytes)
return HostEndian;
if (HostEndian == support::little)
return support::big;
return support::little;
inline uint8_t getNumPaddingBytes(uint64_t SizeInBytes) {
return 7 & (sizeof(uint64_t) - SizeInBytes % sizeof(uint64_t));
Error readName(NamedInstrProfRecord &Record);
Error readFuncHash(NamedInstrProfRecord &Record);
Error readRawCounts(InstrProfRecord &Record);
Error readValueProfilingData(InstrProfRecord &Record);
bool atEnd() const { return Data == DataEnd; }
void advanceData() {
ValueDataStart += CurValueDataSize;
const char *getNextHeaderPos() const {
return (const char *)ValueDataStart;
const uint64_t *getCounter(IntPtrT CounterPtr) const {
ptrdiff_t Offset = (swap(CounterPtr) - CountersDelta) / sizeof(uint64_t);
return CountersStart + Offset;
StringRef getName(uint64_t NameRef) const {
return Symtab->getFuncName(swap(NameRef));
using RawInstrProfReader32 = RawInstrProfReader<uint32_t>;
using RawInstrProfReader64 = RawInstrProfReader<uint64_t>;
namespace IndexedInstrProf {
enum class HashT : uint32_t;
} // end namespace IndexedInstrProf
/// Trait for lookups into the on-disk hash table for the binary instrprof
/// format.
class InstrProfLookupTrait {
std::vector<NamedInstrProfRecord> DataBuffer;
IndexedInstrProf::HashT HashType;
unsigned FormatVersion;
// Endianness of the input value profile data.
// It should be LE by default, but can be changed
// for testing purpose.
support::endianness ValueProfDataEndianness = support::little;
InstrProfLookupTrait(IndexedInstrProf::HashT HashType, unsigned FormatVersion)
: HashType(HashType), FormatVersion(FormatVersion) {}
using data_type = ArrayRef<NamedInstrProfRecord>;
using internal_key_type = StringRef;
using external_key_type = StringRef;
using hash_value_type = uint64_t;
using offset_type = uint64_t;
static bool EqualKey(StringRef A, StringRef B) { return A == B; }
static StringRef GetInternalKey(StringRef K) { return K; }
static StringRef GetExternalKey(StringRef K) { return K; }
hash_value_type ComputeHash(StringRef K);
static std::pair<offset_type, offset_type>
ReadKeyDataLength(const unsigned char *&D) {
using namespace support;
offset_type KeyLen = endian::readNext<offset_type, little, unaligned>(D);
offset_type DataLen = endian::readNext<offset_type, little, unaligned>(D);
return std::make_pair(KeyLen, DataLen);
StringRef ReadKey(const unsigned char *D, offset_type N) {
return StringRef((const char *)D, N);
bool readValueProfilingData(const unsigned char *&D,
const unsigned char *const End);
data_type ReadData(StringRef K, const unsigned char *D, offset_type N);
// Used for testing purpose only.
void setValueProfDataEndianness(support::endianness Endianness) {
ValueProfDataEndianness = Endianness;
struct InstrProfReaderIndexBase {
virtual ~InstrProfReaderIndexBase() = default;
// Read all the profile records with the same key pointed to the current
// iterator.
virtual Error getRecords(ArrayRef<NamedInstrProfRecord> &Data) = 0;
// Read all the profile records with the key equal to FuncName
virtual Error getRecords(StringRef FuncName,
ArrayRef<NamedInstrProfRecord> &Data) = 0;
virtual void advanceToNextKey() = 0;
virtual bool atEnd() const = 0;
virtual void setValueProfDataEndianness(support::endianness Endianness) = 0;
virtual uint64_t getVersion() const = 0;
virtual bool isIRLevelProfile() const = 0;
virtual Error populateSymtab(InstrProfSymtab &) = 0;
using OnDiskHashTableImplV3 =
template <typename HashTableImpl>
class InstrProfReaderItaniumRemapper;
template <typename HashTableImpl>
class InstrProfReaderIndex : public InstrProfReaderIndexBase {
std::unique_ptr<HashTableImpl> HashTable;
typename HashTableImpl::data_iterator RecordIterator;
uint64_t FormatVersion;
friend class InstrProfReaderItaniumRemapper<HashTableImpl>;
InstrProfReaderIndex(const unsigned char *Buckets,
const unsigned char *const Payload,
const unsigned char *const Base,
IndexedInstrProf::HashT HashType, uint64_t Version);
~InstrProfReaderIndex() override = default;
Error getRecords(ArrayRef<NamedInstrProfRecord> &Data) override;
Error getRecords(StringRef FuncName,
ArrayRef<NamedInstrProfRecord> &Data) override;
void advanceToNextKey() override { RecordIterator++; }
bool atEnd() const override {
return RecordIterator == HashTable->data_end();
void setValueProfDataEndianness(support::endianness Endianness) override {
uint64_t getVersion() const override { return GET_VERSION(FormatVersion); }
bool isIRLevelProfile() const override {
return (FormatVersion & VARIANT_MASK_IR_PROF) != 0;
Error populateSymtab(InstrProfSymtab &Symtab) override {
return Symtab.create(HashTable->keys());
/// Name matcher supporting fuzzy matching of symbol names to names in profiles.
class InstrProfReaderRemapper {
virtual ~InstrProfReaderRemapper() {}
virtual Error populateRemappings() { return Error::success(); }
virtual Error getRecords(StringRef FuncName,
ArrayRef<NamedInstrProfRecord> &Data) = 0;
/// Reader for the indexed binary instrprof format.
class IndexedInstrProfReader : public InstrProfReader {
/// The profile data file contents.
std::unique_ptr<MemoryBuffer> DataBuffer;
/// The profile remapping file contents.
std::unique_ptr<MemoryBuffer> RemappingBuffer;
/// The index into the profile data.
std::unique_ptr<InstrProfReaderIndexBase> Index;
/// The profile remapping file contents.
std::unique_ptr<InstrProfReaderRemapper> Remapper;
/// Profile summary data.
std::unique_ptr<ProfileSummary> Summary;
// Index to the current record in the record array.
unsigned RecordIndex;
// Read the profile summary. Return a pointer pointing to one byte past the
// end of the summary data if it exists or the input \c Cur.
const unsigned char *readSummary(IndexedInstrProf::ProfVersion Version,
const unsigned char *Cur);
std::unique_ptr<MemoryBuffer> DataBuffer,
std::unique_ptr<MemoryBuffer> RemappingBuffer = nullptr)
: DataBuffer(std::move(DataBuffer)),
RemappingBuffer(std::move(RemappingBuffer)), RecordIndex(0) {}
IndexedInstrProfReader(const IndexedInstrProfReader &) = delete;
IndexedInstrProfReader &operator=(const IndexedInstrProfReader &) = delete;
/// Return the profile version.
uint64_t getVersion() const { return Index->getVersion(); }
bool isIRLevelProfile() const override { return Index->isIRLevelProfile(); }
/// Return true if the given buffer is in an indexed instrprof format.
static bool hasFormat(const MemoryBuffer &DataBuffer);
/// Read the file header.
Error readHeader() override;
/// Read a single record.
Error readNextRecord(NamedInstrProfRecord &Record) override;
/// Return the NamedInstrProfRecord associated with FuncName and FuncHash
Expected<InstrProfRecord> getInstrProfRecord(StringRef FuncName,
uint64_t FuncHash);
/// Fill Counts with the profile data for the given function name.
Error getFunctionCounts(StringRef FuncName, uint64_t FuncHash,
std::vector<uint64_t> &Counts);
/// Return the maximum of all known function counts.
uint64_t getMaximumFunctionCount() { return Summary->getMaxFunctionCount(); }
/// Factory method to create an indexed reader.
static Expected<std::unique_ptr<IndexedInstrProfReader>>
create(const Twine &Path, const Twine &RemappingPath = "");
static Expected<std::unique_ptr<IndexedInstrProfReader>>
create(std::unique_ptr<MemoryBuffer> Buffer,
std::unique_ptr<MemoryBuffer> RemappingBuffer = nullptr);
// Used for testing purpose only.
void setValueProfDataEndianness(support::endianness Endianness) {
// See description in the base class. This interface is designed
// to be used by llvm-profdata (for dumping). Avoid using this when
// the client is the compiler.
InstrProfSymtab &getSymtab() override;
ProfileSummary &getSummary() { return *(Summary.get()); }
} // end namespace llvm