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//===- InstrProfWriter.cpp - Instrumented profiling writer ----------------===//
//
// 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 writing profiling data for clang's
// instrumentation based PGO and coverage.
//
//===----------------------------------------------------------------------===//
#include "llvm/ProfileData/InstrProfWriter.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/ProfileSummary.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/ProfileData/ProfileCommon.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/OnDiskHashTable.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstdint>
#include <memory>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace llvm;
// A struct to define how the data stream should be patched. For Indexed
// profiling, only uint64_t data type is needed.
struct PatchItem {
uint64_t Pos; // Where to patch.
uint64_t *D; // Pointer to an array of source data.
int N; // Number of elements in \c D array.
};
namespace llvm {
// A wrapper class to abstract writer stream with support of bytes
// back patching.
class ProfOStream {
public:
ProfOStream(raw_fd_ostream &FD) : IsFDOStream(true), OS(FD), LE(FD) {}
ProfOStream(raw_string_ostream &STR)
: IsFDOStream(false), OS(STR), LE(STR) {}
uint64_t tell() { return OS.tell(); }
void write(uint64_t V) { LE.write<uint64_t>(V); }
// \c patch can only be called when all data is written and flushed.
// For raw_string_ostream, the patch is done on the target string
// directly and it won't be reflected in the stream's internal buffer.
void patch(PatchItem *P, int NItems) {
using namespace support;
if (IsFDOStream) {
raw_fd_ostream &FDOStream = static_cast<raw_fd_ostream &>(OS);
for (int K = 0; K < NItems; K++) {
FDOStream.seek(P[K].Pos);
for (int I = 0; I < P[K].N; I++)
write(P[K].D[I]);
}
} else {
raw_string_ostream &SOStream =
static_cast<llvm::raw_string_ostream &>(OS);
std::string &Data = SOStream.str(); // with flush
for (int K = 0; K < NItems; K++) {
for (int I = 0; I < P[K].N; I++) {
uint64_t Bytes = endian::byte_swap<uint64_t, little>(P[K].D[I]);
Data.replace(P[K].Pos + I * sizeof(uint64_t), sizeof(uint64_t),
(const char *)&Bytes, sizeof(uint64_t));
}
}
}
}
// If \c OS is an instance of \c raw_fd_ostream, this field will be
// true. Otherwise, \c OS will be an raw_string_ostream.
bool IsFDOStream;
raw_ostream &OS;
support::endian::Writer<support::little> LE;
};
class InstrProfRecordWriterTrait {
public:
typedef StringRef key_type;
typedef StringRef key_type_ref;
typedef const InstrProfWriter::ProfilingData *const data_type;
typedef const InstrProfWriter::ProfilingData *const data_type_ref;
typedef uint64_t hash_value_type;
typedef uint64_t offset_type;
support::endianness ValueProfDataEndianness = support::little;
InstrProfSummaryBuilder *SummaryBuilder;
InstrProfRecordWriterTrait() = default;
static hash_value_type ComputeHash(key_type_ref K) {
return IndexedInstrProf::ComputeHash(K);
}
static std::pair<offset_type, offset_type>
EmitKeyDataLength(raw_ostream &Out, key_type_ref K, data_type_ref V) {
using namespace support;
endian::Writer<little> LE(Out);
offset_type N = K.size();
LE.write<offset_type>(N);
offset_type M = 0;
for (const auto &ProfileData : *V) {
const InstrProfRecord &ProfRecord = ProfileData.second;
M += sizeof(uint64_t); // The function hash
M += sizeof(uint64_t); // The size of the Counts vector
M += ProfRecord.Counts.size() * sizeof(uint64_t);
// Value data
M += ValueProfData::getSize(ProfileData.second);
}
LE.write<offset_type>(M);
return std::make_pair(N, M);
}
void EmitKey(raw_ostream &Out, key_type_ref K, offset_type N) {
Out.write(K.data(), N);
}
void EmitData(raw_ostream &Out, key_type_ref, data_type_ref V, offset_type) {
using namespace support;
endian::Writer<little> LE(Out);
for (const auto &ProfileData : *V) {
const InstrProfRecord &ProfRecord = ProfileData.second;
SummaryBuilder->addRecord(ProfRecord);
LE.write<uint64_t>(ProfileData.first); // Function hash
LE.write<uint64_t>(ProfRecord.Counts.size());
for (uint64_t I : ProfRecord.Counts)
LE.write<uint64_t>(I);
// Write value data
std::unique_ptr<ValueProfData> VDataPtr =
ValueProfData::serializeFrom(ProfileData.second);
uint32_t S = VDataPtr->getSize();
VDataPtr->swapBytesFromHost(ValueProfDataEndianness);
Out.write((const char *)VDataPtr.get(), S);
}
}
};
} // end namespace llvm
InstrProfWriter::InstrProfWriter(bool Sparse)
: Sparse(Sparse), InfoObj(new InstrProfRecordWriterTrait()) {}
InstrProfWriter::~InstrProfWriter() { delete InfoObj; }
// Internal interface for testing purpose only.
void InstrProfWriter::setValueProfDataEndianness(
support::endianness Endianness) {
InfoObj->ValueProfDataEndianness = Endianness;
}
void InstrProfWriter::setOutputSparse(bool Sparse) {
this->Sparse = Sparse;
}
Error InstrProfWriter::addRecord(InstrProfRecord &&I, uint64_t Weight) {
auto &ProfileDataMap = FunctionData[I.Name];
bool NewFunc;
ProfilingData::iterator Where;
std::tie(Where, NewFunc) =
ProfileDataMap.insert(std::make_pair(I.Hash, InstrProfRecord()));
InstrProfRecord &Dest = Where->second;
if (NewFunc) {
// We've never seen a function with this name and hash, add it.
Dest = std::move(I);
// Fix up the name to avoid dangling reference.
Dest.Name = FunctionData.find(Dest.Name)->getKey();
if (Weight > 1)
Dest.scale(Weight);
} else {
// We're updating a function we've seen before.
Dest.merge(I, Weight);
}
Dest.sortValueData();
return Dest.takeError();
}
Error InstrProfWriter::mergeRecordsFromWriter(InstrProfWriter &&IPW) {
for (auto &I : IPW.FunctionData)
for (auto &Func : I.getValue())
if (Error E = addRecord(std::move(Func.second), 1))
return E;
return Error::success();
}
bool InstrProfWriter::shouldEncodeData(const ProfilingData &PD) {
if (!Sparse)
return true;
for (const auto &Func : PD) {
const InstrProfRecord &IPR = Func.second;
if (llvm::any_of(IPR.Counts, [](uint64_t Count) { return Count > 0; }))
return true;
}
return false;
}
static void setSummary(IndexedInstrProf::Summary *TheSummary,
ProfileSummary &PS) {
using namespace IndexedInstrProf;
std::vector<ProfileSummaryEntry> &Res = PS.getDetailedSummary();
TheSummary->NumSummaryFields = Summary::NumKinds;
TheSummary->NumCutoffEntries = Res.size();
TheSummary->set(Summary::MaxFunctionCount, PS.getMaxFunctionCount());
TheSummary->set(Summary::MaxBlockCount, PS.getMaxCount());
TheSummary->set(Summary::MaxInternalBlockCount, PS.getMaxInternalCount());
TheSummary->set(Summary::TotalBlockCount, PS.getTotalCount());
TheSummary->set(Summary::TotalNumBlocks, PS.getNumCounts());
TheSummary->set(Summary::TotalNumFunctions, PS.getNumFunctions());
for (unsigned I = 0; I < Res.size(); I++)
TheSummary->setEntry(I, Res[I]);
}
void InstrProfWriter::writeImpl(ProfOStream &OS) {
using namespace IndexedInstrProf;
OnDiskChainedHashTableGenerator<InstrProfRecordWriterTrait> Generator;
InstrProfSummaryBuilder ISB(ProfileSummaryBuilder::DefaultCutoffs);
InfoObj->SummaryBuilder = &ISB;
// Populate the hash table generator.
for (const auto &I : FunctionData)
if (shouldEncodeData(I.getValue()))
Generator.insert(I.getKey(), &I.getValue());
// Write the header.
IndexedInstrProf::Header Header;
Header.Magic = IndexedInstrProf::Magic;
Header.Version = IndexedInstrProf::ProfVersion::CurrentVersion;
if (ProfileKind == PF_IRLevel)
Header.Version |= VARIANT_MASK_IR_PROF;
Header.Unused = 0;
Header.HashType = static_cast<uint64_t>(IndexedInstrProf::HashType);
Header.HashOffset = 0;
int N = sizeof(IndexedInstrProf::Header) / sizeof(uint64_t);
// Only write out all the fields except 'HashOffset'. We need
// to remember the offset of that field to allow back patching
// later.
for (int I = 0; I < N - 1; I++)
OS.write(reinterpret_cast<uint64_t *>(&Header)[I]);
// Save the location of Header.HashOffset field in \c OS.
uint64_t HashTableStartFieldOffset = OS.tell();
// Reserve the space for HashOffset field.
OS.write(0);
// Reserve space to write profile summary data.
uint32_t NumEntries = ProfileSummaryBuilder::DefaultCutoffs.size();
uint32_t SummarySize = Summary::getSize(Summary::NumKinds, NumEntries);
// Remember the summary offset.
uint64_t SummaryOffset = OS.tell();
for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++)
OS.write(0);
// Write the hash table.
uint64_t HashTableStart = Generator.Emit(OS.OS, *InfoObj);
// Allocate space for data to be serialized out.
std::unique_ptr<IndexedInstrProf::Summary> TheSummary =
IndexedInstrProf::allocSummary(SummarySize);
// Compute the Summary and copy the data to the data
// structure to be serialized out (to disk or buffer).
std::unique_ptr<ProfileSummary> PS = ISB.getSummary();
setSummary(TheSummary.get(), *PS);
InfoObj->SummaryBuilder = nullptr;
// Now do the final patch:
PatchItem PatchItems[] = {
// Patch the Header.HashOffset field.
{HashTableStartFieldOffset, &HashTableStart, 1},
// Patch the summary data.
{SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()),
(int)(SummarySize / sizeof(uint64_t))}};
OS.patch(PatchItems, sizeof(PatchItems) / sizeof(*PatchItems));
}
void InstrProfWriter::write(raw_fd_ostream &OS) {
// Write the hash table.
ProfOStream POS(OS);
writeImpl(POS);
}
std::unique_ptr<MemoryBuffer> InstrProfWriter::writeBuffer() {
std::string Data;
raw_string_ostream OS(Data);
ProfOStream POS(OS);
// Write the hash table.
writeImpl(POS);
// Return this in an aligned memory buffer.
return MemoryBuffer::getMemBufferCopy(Data);
}
static const char *ValueProfKindStr[] = {
#define VALUE_PROF_KIND(Enumerator, Value) #Enumerator,
#include "llvm/ProfileData/InstrProfData.inc"
};
void InstrProfWriter::writeRecordInText(const InstrProfRecord &Func,
InstrProfSymtab &Symtab,
raw_fd_ostream &OS) {
OS << Func.Name << "\n";
OS << "# Func Hash:\n" << Func.Hash << "\n";
OS << "# Num Counters:\n" << Func.Counts.size() << "\n";
OS << "# Counter Values:\n";
for (uint64_t Count : Func.Counts)
OS << Count << "\n";
uint32_t NumValueKinds = Func.getNumValueKinds();
if (!NumValueKinds) {
OS << "\n";
return;
}
OS << "# Num Value Kinds:\n" << Func.getNumValueKinds() << "\n";
for (uint32_t VK = 0; VK < IPVK_Last + 1; VK++) {
uint32_t NS = Func.getNumValueSites(VK);
if (!NS)
continue;
OS << "# ValueKind = " << ValueProfKindStr[VK] << ":\n" << VK << "\n";
OS << "# NumValueSites:\n" << NS << "\n";
for (uint32_t S = 0; S < NS; S++) {
uint32_t ND = Func.getNumValueDataForSite(VK, S);
OS << ND << "\n";
std::unique_ptr<InstrProfValueData[]> VD = Func.getValueForSite(VK, S);
for (uint32_t I = 0; I < ND; I++) {
if (VK == IPVK_IndirectCallTarget)
OS << Symtab.getFuncName(VD[I].Value) << ":" << VD[I].Count << "\n";
else
OS << VD[I].Value << ":" << VD[I].Count << "\n";
}
}
}
OS << "\n";
}
void InstrProfWriter::writeText(raw_fd_ostream &OS) {
if (ProfileKind == PF_IRLevel)
OS << "# IR level Instrumentation Flag\n:ir\n";
InstrProfSymtab Symtab;
for (const auto &I : FunctionData)
if (shouldEncodeData(I.getValue()))
Symtab.addFuncName(I.getKey());
Symtab.finalizeSymtab();
for (const auto &I : FunctionData)
if (shouldEncodeData(I.getValue()))
for (const auto &Func : I.getValue())
writeRecordInText(Func.second, Symtab, OS);
}