lib/ProfileData/InstrProfReader.cpp

   1 //===- InstrProfReader.cpp - Instrumented profiling reader ----------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains support for reading profiling data for clang's
  10 // instrumentation based PGO and coverage.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ProfileData/InstrProfReader.h"
  15 #include "llvm/ADT/ArrayRef.h"
  16 #include "llvm/ADT/DenseMap.h"
  17 #include "llvm/ADT/STLExtras.h"
  18 #include "llvm/ADT/StringRef.h"
  19 #include "llvm/IR/ProfileSummary.h"
  20 #include "llvm/ProfileData/InstrProf.h"
  21 #include "llvm/ProfileData/ProfileCommon.h"
  22 #include "llvm/Support/Endian.h"
  23 #include "llvm/Support/Error.h"
  24 #include "llvm/Support/ErrorOr.h"
  25 #include "llvm/Support/MemoryBuffer.h"
  26 #include "llvm/Support/SymbolRemappingReader.h"
  27 #include "llvm/Support/SwapByteOrder.h"
  28 #include <algorithm>
  29 #include <cctype>
  30 #include <cstddef>
  31 #include <cstdint>
  32 #include <limits>
  33 #include <memory>
  34 #include <system_error>
  35 #include <utility>
  36 #include <vector>
  37
  38 using namespace llvm;
  39
  40 static Expected<std::unique_ptr<MemoryBuffer>>
  41 setupMemoryBuffer(const Twine &Path) {
  42   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
  43       MemoryBuffer::getFileOrSTDIN(Path);
  44   if (std::error_code EC = BufferOrErr.getError())
  45     return errorCodeToError(EC);
  46   return std::move(BufferOrErr.get());
  47 }
  48
  49 static Error initializeReader(InstrProfReader &Reader) {
  50   return Reader.readHeader();
  51 }
  52
  53 Expected<std::unique_ptr<InstrProfReader>>
  54 InstrProfReader::create(const Twine &Path) {
  55   // Set up the buffer to read.
  56   auto BufferOrError = setupMemoryBuffer(Path);
  57   if (Error E = BufferOrError.takeError())
  58     return std::move(E);
  59   return InstrProfReader::create(std::move(BufferOrError.get()));
  60 }
  61
  62 Expected<std::unique_ptr<InstrProfReader>>
  63 InstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
  64   // Sanity check the buffer.
  65   if (uint64_t(Buffer->getBufferSize()) > std::numeric_limits<uint64_t>::max())
  66     return make_error<InstrProfError>(instrprof_error::too_large);
  67
  68   if (Buffer->getBufferSize() == 0)
  69     return make_error<InstrProfError>(instrprof_error::empty_raw_profile);
  70
  71   std::unique_ptr<InstrProfReader> Result;
  72   // Create the reader.
  73   if (IndexedInstrProfReader::hasFormat(*Buffer))
  74     Result.reset(new IndexedInstrProfReader(std::move(Buffer)));
  75   else if (RawInstrProfReader64::hasFormat(*Buffer))
  76     Result.reset(new RawInstrProfReader64(std::move(Buffer)));
  77   else if (RawInstrProfReader32::hasFormat(*Buffer))
  78     Result.reset(new RawInstrProfReader32(std::move(Buffer)));
  79   else if (TextInstrProfReader::hasFormat(*Buffer))
  80     Result.reset(new TextInstrProfReader(std::move(Buffer)));
  81   else
  82     return make_error<InstrProfError>(instrprof_error::unrecognized_format);
  83
  84   // Initialize the reader and return the result.
  85   if (Error E = initializeReader(*Result))
  86     return std::move(E);
  87
  88   return std::move(Result);
  89 }
  90
  91 Expected<std::unique_ptr<IndexedInstrProfReader>>
  92 IndexedInstrProfReader::create(const Twine &Path, const Twine &RemappingPath) {
  93   // Set up the buffer to read.
  94   auto BufferOrError = setupMemoryBuffer(Path);
  95   if (Error E = BufferOrError.takeError())
  96     return std::move(E);
  97
  98   // Set up the remapping buffer if requested.
  99   std::unique_ptr<MemoryBuffer> RemappingBuffer;
 100   std::string RemappingPathStr = RemappingPath.str();
 101   if (!RemappingPathStr.empty()) {
 102     auto RemappingBufferOrError = setupMemoryBuffer(RemappingPathStr);
 103     if (Error E = RemappingBufferOrError.takeError())
 104       return std::move(E);
 105     RemappingBuffer = std::move(RemappingBufferOrError.get());
 106   }
 107
 108   return IndexedInstrProfReader::create(std::move(BufferOrError.get()),
 109                                         std::move(RemappingBuffer));
 110 }
 111
 112 Expected<std::unique_ptr<IndexedInstrProfReader>>
 113 IndexedInstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer,
 114                                std::unique_ptr<MemoryBuffer> RemappingBuffer) {
 115   // Sanity check the buffer.
 116   if (uint64_t(Buffer->getBufferSize()) > std::numeric_limits<uint64_t>::max())
 117     return make_error<InstrProfError>(instrprof_error::too_large);
 118
 119   // Create the reader.
 120   if (!IndexedInstrProfReader::hasFormat(*Buffer))
 121     return make_error<InstrProfError>(instrprof_error::bad_magic);
 122   auto Result = std::make_unique<IndexedInstrProfReader>(
 123       std::move(Buffer), std::move(RemappingBuffer));
 124
 125   // Initialize the reader and return the result.
 126   if (Error E = initializeReader(*Result))
 127     return std::move(E);
 128
 129   return std::move(Result);
 130 }
 131
 132 void InstrProfIterator::Increment() {
 133   if (auto E = Reader->readNextRecord(Record)) {
 134     // Handle errors in the reader.
 135     InstrProfError::take(std::move(E));
 136     *this = InstrProfIterator();
 137   }
 138 }
 139
 140 bool TextInstrProfReader::hasFormat(const MemoryBuffer &Buffer) {
 141   // Verify that this really looks like plain ASCII text by checking a
 142   // 'reasonable' number of characters (up to profile magic size).
 143   size_t count = std::min(Buffer.getBufferSize(), sizeof(uint64_t));
 144   StringRef buffer = Buffer.getBufferStart();
 145   return count == 0 ||
 146          std::all_of(buffer.begin(), buffer.begin() + count,
 147                      [](char c) { return isPrint(c) || ::isspace(c); });
 148 }
 149
 150 // Read the profile variant flag from the header: ":FE" means this is a FE
 151 // generated profile. ":IR" means this is an IR level profile. Other strings
 152 // with a leading ':' will be reported an error format.
 153 Error TextInstrProfReader::readHeader() {
 154   Symtab.reset(new InstrProfSymtab());
 155   bool IsIRInstr = false;
 156   if (!Line->startswith(":")) {
 157     IsIRLevelProfile = false;
 158     return success();
 159   }
 160   StringRef Str = (Line)->substr(1);
 161   if (Str.equals_lower("ir"))
 162     IsIRInstr = true;
 163   else if (Str.equals_lower("fe"))
 164     IsIRInstr = false;
 165   else if (Str.equals_lower("csir")) {
 166     IsIRInstr = true;
 167     HasCSIRLevelProfile = true;
 168   } else
 169     return error(instrprof_error::bad_header);
 170
 171   ++Line;
 172   IsIRLevelProfile = IsIRInstr;
 173   return success();
 174 }
 175
 176 Error
 177 TextInstrProfReader::readValueProfileData(InstrProfRecord &Record) {
 178
 179 #define CHECK_LINE_END(Line)                                                   \
 180   if (Line.is_at_end())                                                        \
 181     return error(instrprof_error::truncated);
 182 #define READ_NUM(Str, Dst)                                                     \
 183   if ((Str).getAsInteger(10, (Dst)))                                           \
 184     return error(instrprof_error::malformed);
 185 #define VP_READ_ADVANCE(Val)                                                   \
 186   CHECK_LINE_END(Line);                                                        \
 187   uint32_t Val;                                                                \
 188   READ_NUM((*Line), (Val));                                                    \
 189   Line++;
 190
 191   if (Line.is_at_end())
 192     return success();
 193
 194   uint32_t NumValueKinds;
 195   if (Line->getAsInteger(10, NumValueKinds)) {
 196     // No value profile data
 197     return success();
 198   }
 199   if (NumValueKinds == 0 || NumValueKinds > IPVK_Last + 1)
 200     return error(instrprof_error::malformed);
 201   Line++;
 202
 203   for (uint32_t VK = 0; VK < NumValueKinds; VK++) {
 204     VP_READ_ADVANCE(ValueKind);
 205     if (ValueKind > IPVK_Last)
 206       return error(instrprof_error::malformed);
 207     VP_READ_ADVANCE(NumValueSites);
 208     if (!NumValueSites)
 209       continue;
 210
 211     Record.reserveSites(VK, NumValueSites);
 212     for (uint32_t S = 0; S < NumValueSites; S++) {
 213       VP_READ_ADVANCE(NumValueData);
 214
 215       std::vector<InstrProfValueData> CurrentValues;
 216       for (uint32_t V = 0; V < NumValueData; V++) {
 217         CHECK_LINE_END(Line);
 218         std::pair<StringRef, StringRef> VD = Line->rsplit(':');
 219         uint64_t TakenCount, Value;
 220         if (ValueKind == IPVK_IndirectCallTarget) {
 221           if (InstrProfSymtab::isExternalSymbol(VD.first)) {
 222             Value = 0;
 223           } else {
 224             if (Error E = Symtab->addFuncName(VD.first))
 225               return E;
 226             Value = IndexedInstrProf::ComputeHash(VD.first);
 227           }
 228         } else {
 229           READ_NUM(VD.first, Value);
 230         }
 231         READ_NUM(VD.second, TakenCount);
 232         CurrentValues.push_back({Value, TakenCount});
 233         Line++;
 234       }
 235       Record.addValueData(ValueKind, S, CurrentValues.data(), NumValueData,
 236                           nullptr);
 237     }
 238   }
 239   return success();
 240
 241 #undef CHECK_LINE_END
 242 #undef READ_NUM
 243 #undef VP_READ_ADVANCE
 244 }
 245
 246 Error TextInstrProfReader::readNextRecord(NamedInstrProfRecord &Record) {
 247   // Skip empty lines and comments.
 248   while (!Line.is_at_end() && (Line->empty() || Line->startswith("#")))
 249     ++Line;
 250   // If we hit EOF while looking for a name, we're done.
 251   if (Line.is_at_end()) {
 252     return error(instrprof_error::eof);
 253   }
 254
 255   // Read the function name.
 256   Record.Name = *Line++;
 257   if (Error E = Symtab->addFuncName(Record.Name))
 258     return error(std::move(E));
 259
 260   // Read the function hash.
 261   if (Line.is_at_end())
 262     return error(instrprof_error::truncated);
 263   if ((Line++)->getAsInteger(0, Record.Hash))
 264     return error(instrprof_error::malformed);
 265
 266   // Read the number of counters.
 267   uint64_t NumCounters;
 268   if (Line.is_at_end())
 269     return error(instrprof_error::truncated);
 270   if ((Line++)->getAsInteger(10, NumCounters))
 271     return error(instrprof_error::malformed);
 272   if (NumCounters == 0)
 273     return error(instrprof_error::malformed);
 274
 275   // Read each counter and fill our internal storage with the values.
 276   Record.Clear();
 277   Record.Counts.reserve(NumCounters);
 278   for (uint64_t I = 0; I < NumCounters; ++I) {
 279     if (Line.is_at_end())
 280       return error(instrprof_error::truncated);
 281     uint64_t Count;
 282     if ((Line++)->getAsInteger(10, Count))
 283       return error(instrprof_error::malformed);
 284     Record.Counts.push_back(Count);
 285   }
 286
 287   // Check if value profile data exists and read it if so.
 288   if (Error E = readValueProfileData(Record))
 289     return error(std::move(E));
 290
 291   return success();
 292 }
 293
 294 template <class IntPtrT>
 295 bool RawInstrProfReader<IntPtrT>::hasFormat(const MemoryBuffer &DataBuffer) {
 296   if (DataBuffer.getBufferSize() < sizeof(uint64_t))
 297     return false;
 298   uint64_t Magic =
 299     *reinterpret_cast<const uint64_t *>(DataBuffer.getBufferStart());
 300   return RawInstrProf::getMagic<IntPtrT>() == Magic ||
 301          sys::getSwappedBytes(RawInstrProf::getMagic<IntPtrT>()) == Magic;
 302 }
 303
 304 template <class IntPtrT>
 305 Error RawInstrProfReader<IntPtrT>::readHeader() {
 306   if (!hasFormat(*DataBuffer))
 307     return error(instrprof_error::bad_magic);
 308   if (DataBuffer->getBufferSize() < sizeof(RawInstrProf::Header))
 309     return error(instrprof_error::bad_header);
 310   auto *Header = reinterpret_cast<const RawInstrProf::Header *>(
 311       DataBuffer->getBufferStart());
 312   ShouldSwapBytes = Header->Magic != RawInstrProf::getMagic<IntPtrT>();
 313   return readHeader(*Header);
 314 }
 315
 316 template <class IntPtrT>
 317 Error RawInstrProfReader<IntPtrT>::readNextHeader(const char *CurrentPos) {
 318   const char *End = DataBuffer->getBufferEnd();
 319   // Skip zero padding between profiles.
 320   while (CurrentPos != End && *CurrentPos == 0)
 321     ++CurrentPos;
 322   // If there's nothing left, we're done.
 323   if (CurrentPos == End)
 324     return make_error<InstrProfError>(instrprof_error::eof);
 325   // If there isn't enough space for another header, this is probably just
 326   // garbage at the end of the file.
 327   if (CurrentPos + sizeof(RawInstrProf::Header) > End)
 328     return make_error<InstrProfError>(instrprof_error::malformed);
 329   // The writer ensures each profile is padded to start at an aligned address.
 330   if (reinterpret_cast<size_t>(CurrentPos) % alignof(uint64_t))
 331     return make_error<InstrProfError>(instrprof_error::malformed);
 332   // The magic should have the same byte order as in the previous header.
 333   uint64_t Magic = *reinterpret_cast<const uint64_t *>(CurrentPos);
 334   if (Magic != swap(RawInstrProf::getMagic<IntPtrT>()))
 335     return make_error<InstrProfError>(instrprof_error::bad_magic);
 336
 337   // There's another profile to read, so we need to process the header.
 338   auto *Header = reinterpret_cast<const RawInstrProf::Header *>(CurrentPos);
 339   return readHeader(*Header);
 340 }
 341
 342 template <class IntPtrT>
 343 Error RawInstrProfReader<IntPtrT>::createSymtab(InstrProfSymtab &Symtab) {
 344   if (Error E = Symtab.create(StringRef(NamesStart, NamesSize)))
 345     return error(std::move(E));
 346   for (const RawInstrProf::ProfileData<IntPtrT> *I = Data; I != DataEnd; ++I) {
 347     const IntPtrT FPtr = swap(I->FunctionPointer);
 348     if (!FPtr)
 349       continue;
 350     Symtab.mapAddress(FPtr, I->NameRef);
 351   }
 352   return success();
 353 }
 354
 355 template <class IntPtrT>
 356 Error RawInstrProfReader<IntPtrT>::readHeader(
 357     const RawInstrProf::Header &Header) {
 358   Version = swap(Header.Version);
 359   if (GET_VERSION(Version) != RawInstrProf::Version)
 360     return error(instrprof_error::unsupported_version);
 361
 362   CountersDelta = swap(Header.CountersDelta);
 363   NamesDelta = swap(Header.NamesDelta);
 364   auto DataSize = swap(Header.DataSize);
 365   auto CountersSize = swap(Header.CountersSize);
 366   NamesSize = swap(Header.NamesSize);
 367   ValueKindLast = swap(Header.ValueKindLast);
 368
 369   auto DataSizeInBytes = DataSize * sizeof(RawInstrProf::ProfileData<IntPtrT>);
 370   auto PaddingSize = getNumPaddingBytes(NamesSize);
 371
 372   ptrdiff_t DataOffset = sizeof(RawInstrProf::Header);
 373   ptrdiff_t CountersOffset = DataOffset + DataSizeInBytes;
 374   ptrdiff_t NamesOffset = CountersOffset + sizeof(uint64_t) * CountersSize;
 375   ptrdiff_t ValueDataOffset = NamesOffset + NamesSize + PaddingSize;
 376
 377   auto *Start = reinterpret_cast<const char *>(&Header);
 378   if (Start + ValueDataOffset > DataBuffer->getBufferEnd())
 379     return error(instrprof_error::bad_header);
 380
 381   Data = reinterpret_cast<const RawInstrProf::ProfileData<IntPtrT> *>(
 382       Start + DataOffset);
 383   DataEnd = Data + DataSize;
 384   CountersStart = reinterpret_cast<const uint64_t *>(Start + CountersOffset);
 385   NamesStart = Start + NamesOffset;
 386   ValueDataStart = reinterpret_cast<const uint8_t *>(Start + ValueDataOffset);
 387
 388   std::unique_ptr<InstrProfSymtab> NewSymtab = std::make_unique<InstrProfSymtab>();
 389   if (Error E = createSymtab(*NewSymtab.get()))
 390     return E;
 391
 392   Symtab = std::move(NewSymtab);
 393   return success();
 394 }
 395
 396 template <class IntPtrT>
 397 Error RawInstrProfReader<IntPtrT>::readName(NamedInstrProfRecord &Record) {
 398   Record.Name = getName(Data->NameRef);
 399   return success();
 400 }
 401
 402 template <class IntPtrT>
 403 Error RawInstrProfReader<IntPtrT>::readFuncHash(NamedInstrProfRecord &Record) {
 404   Record.Hash = swap(Data->FuncHash);
 405   return success();
 406 }
 407
 408 template <class IntPtrT>
 409 Error RawInstrProfReader<IntPtrT>::readRawCounts(
 410     InstrProfRecord &Record) {
 411   uint32_t NumCounters = swap(Data->NumCounters);
 412   IntPtrT CounterPtr = Data->CounterPtr;
 413   if (NumCounters == 0)
 414     return error(instrprof_error::malformed);
 415
 416   auto *NamesStartAsCounter = reinterpret_cast<const uint64_t *>(NamesStart);
 417   ptrdiff_t MaxNumCounters = NamesStartAsCounter - CountersStart;
 418
 419   // Check bounds. Note that the counter pointer embedded in the data record
 420   // may itself be corrupt.
 421   if (NumCounters > MaxNumCounters)
 422     return error(instrprof_error::malformed);
 423   ptrdiff_t CounterOffset = getCounterOffset(CounterPtr);
 424   if (CounterOffset < 0 || CounterOffset > MaxNumCounters ||
 425       (CounterOffset + NumCounters) > MaxNumCounters)
 426     return error(instrprof_error::malformed);
 427
 428   auto RawCounts = makeArrayRef(getCounter(CounterOffset), NumCounters);
 429
 430   if (ShouldSwapBytes) {
 431     Record.Counts.clear();
 432     Record.Counts.reserve(RawCounts.size());
 433     for (uint64_t Count : RawCounts)
 434       Record.Counts.push_back(swap(Count));
 435   } else
 436     Record.Counts = RawCounts;
 437
 438   return success();
 439 }
 440
 441 template <class IntPtrT>
 442 Error RawInstrProfReader<IntPtrT>::readValueProfilingData(
 443     InstrProfRecord &Record) {
 444   Record.clearValueData();
 445   CurValueDataSize = 0;
 446   // Need to match the logic in value profile dumper code in compiler-rt:
 447   uint32_t NumValueKinds = 0;
 448   for (uint32_t I = 0; I < IPVK_Last + 1; I++)
 449     NumValueKinds += (Data->NumValueSites[I] != 0);
 450
 451   if (!NumValueKinds)
 452     return success();
 453
 454   Expected<std::unique_ptr<ValueProfData>> VDataPtrOrErr =
 455       ValueProfData::getValueProfData(
 456           ValueDataStart, (const unsigned char *)DataBuffer->getBufferEnd(),
 457           getDataEndianness());
 458
 459   if (Error E = VDataPtrOrErr.takeError())
 460     return E;
 461
 462   // Note that besides deserialization, this also performs the conversion for
 463   // indirect call targets.  The function pointers from the raw profile are
 464   // remapped into function name hashes.
 465   VDataPtrOrErr.get()->deserializeTo(Record, Symtab.get());
 466   CurValueDataSize = VDataPtrOrErr.get()->getSize();
 467   return success();
 468 }
 469
 470 template <class IntPtrT>
 471 Error RawInstrProfReader<IntPtrT>::readNextRecord(NamedInstrProfRecord &Record) {
 472   if (atEnd())
 473     // At this point, ValueDataStart field points to the next header.
 474     if (Error E = readNextHeader(getNextHeaderPos()))
 475       return error(std::move(E));
 476
 477   // Read name ad set it in Record.
 478   if (Error E = readName(Record))
 479     return error(std::move(E));
 480
 481   // Read FuncHash and set it in Record.
 482   if (Error E = readFuncHash(Record))
 483     return error(std::move(E));
 484
 485   // Read raw counts and set Record.
 486   if (Error E = readRawCounts(Record))
 487     return error(std::move(E));
 488
 489   // Read value data and set Record.
 490   if (Error E = readValueProfilingData(Record))
 491     return error(std::move(E));
 492
 493   // Iterate.
 494   advanceData();
 495   return success();
 496 }
 497
 498 namespace llvm {
 499
 500 template class RawInstrProfReader<uint32_t>;
 501 template class RawInstrProfReader<uint64_t>;
 502
 503 } // end namespace llvm
 504
 505 InstrProfLookupTrait::hash_value_type
 506 InstrProfLookupTrait::ComputeHash(StringRef K) {
 507   return IndexedInstrProf::ComputeHash(HashType, K);
 508 }
 509
 510 using data_type = InstrProfLookupTrait::data_type;
 511 using offset_type = InstrProfLookupTrait::offset_type;
 512
 513 bool InstrProfLookupTrait::readValueProfilingData(
 514     const unsigned char *&D, const unsigned char *const End) {
 515   Expected<std::unique_ptr<ValueProfData>> VDataPtrOrErr =
 516       ValueProfData::getValueProfData(D, End, ValueProfDataEndianness);
 517
 518   if (VDataPtrOrErr.takeError())
 519     return false;
 520
 521   VDataPtrOrErr.get()->deserializeTo(DataBuffer.back(), nullptr);
 522   D += VDataPtrOrErr.get()->TotalSize;
 523
 524   return true;
 525 }
 526
 527 data_type InstrProfLookupTrait::ReadData(StringRef K, const unsigned char *D,
 528                                          offset_type N) {
 529   using namespace support;
 530
 531   // Check if the data is corrupt. If so, don't try to read it.
 532   if (N % sizeof(uint64_t))
 533     return data_type();
 534
 535   DataBuffer.clear();
 536   std::vector<uint64_t> CounterBuffer;
 537
 538   const unsigned char *End = D + N;
 539   while (D < End) {
 540     // Read hash.
 541     if (D + sizeof(uint64_t) >= End)
 542       return data_type();
 543     uint64_t Hash = endian::readNext<uint64_t, little, unaligned>(D);
 544
 545     // Initialize number of counters for GET_VERSION(FormatVersion) == 1.
 546     uint64_t CountsSize = N / sizeof(uint64_t) - 1;
 547     // If format version is different then read the number of counters.
 548     if (GET_VERSION(FormatVersion) != IndexedInstrProf::ProfVersion::Version1) {
 549       if (D + sizeof(uint64_t) > End)
 550         return data_type();
 551       CountsSize = endian::readNext<uint64_t, little, unaligned>(D);
 552     }
 553     // Read counter values.
 554     if (D + CountsSize * sizeof(uint64_t) > End)
 555       return data_type();
 556
 557     CounterBuffer.clear();
 558     CounterBuffer.reserve(CountsSize);
 559     for (uint64_t J = 0; J < CountsSize; ++J)
 560       CounterBuffer.push_back(endian::readNext<uint64_t, little, unaligned>(D));
 561
 562     DataBuffer.emplace_back(K, Hash, std::move(CounterBuffer));
 563
 564     // Read value profiling data.
 565     if (GET_VERSION(FormatVersion) > IndexedInstrProf::ProfVersion::Version2 &&
 566         !readValueProfilingData(D, End)) {
 567       DataBuffer.clear();
 568       return data_type();
 569     }
 570   }
 571   return DataBuffer;
 572 }
 573
 574 template <typename HashTableImpl>
 575 Error InstrProfReaderIndex<HashTableImpl>::getRecords(
 576     StringRef FuncName, ArrayRef<NamedInstrProfRecord> &Data) {
 577   auto Iter = HashTable->find(FuncName);
 578   if (Iter == HashTable->end())
 579     return make_error<InstrProfError>(instrprof_error::unknown_function);
 580
 581   Data = (*Iter);
 582   if (Data.empty())
 583     return make_error<InstrProfError>(instrprof_error::malformed);
 584
 585   return Error::success();
 586 }
 587
 588 template <typename HashTableImpl>
 589 Error InstrProfReaderIndex<HashTableImpl>::getRecords(
 590     ArrayRef<NamedInstrProfRecord> &Data) {
 591   if (atEnd())
 592     return make_error<InstrProfError>(instrprof_error::eof);
 593
 594   Data = *RecordIterator;
 595
 596   if (Data.empty())
 597     return make_error<InstrProfError>(instrprof_error::malformed);
 598
 599   return Error::success();
 600 }
 601
 602 template <typename HashTableImpl>
 603 InstrProfReaderIndex<HashTableImpl>::InstrProfReaderIndex(
 604     const unsigned char *Buckets, const unsigned char *const Payload,
 605     const unsigned char *const Base, IndexedInstrProf::HashT HashType,
 606     uint64_t Version) {
 607   FormatVersion = Version;
 608   HashTable.reset(HashTableImpl::Create(
 609       Buckets, Payload, Base,
 610       typename HashTableImpl::InfoType(HashType, Version)));
 611   RecordIterator = HashTable->data_begin();
 612 }
 613
 614 namespace {
 615 /// A remapper that does not apply any remappings.
 616 class InstrProfReaderNullRemapper : public InstrProfReaderRemapper {
 617   InstrProfReaderIndexBase &Underlying;
 618
 619 public:
 620   InstrProfReaderNullRemapper(InstrProfReaderIndexBase &Underlying)
 621       : Underlying(Underlying) {}
 622
 623   Error getRecords(StringRef FuncName,
 624                    ArrayRef<NamedInstrProfRecord> &Data) override {
 625     return Underlying.getRecords(FuncName, Data);
 626   }
 627 };
 628 }
 629
 630 /// A remapper that applies remappings based on a symbol remapping file.
 631 template <typename HashTableImpl>
 632 class llvm::InstrProfReaderItaniumRemapper
 633     : public InstrProfReaderRemapper {
 634 public:
 635   InstrProfReaderItaniumRemapper(
 636       std::unique_ptr<MemoryBuffer> RemapBuffer,
 637       InstrProfReaderIndex<HashTableImpl> &Underlying)
 638       : RemapBuffer(std::move(RemapBuffer)), Underlying(Underlying) {
 639   }
 640
 641   /// Extract the original function name from a PGO function name.
 642   static StringRef extractName(StringRef Name) {
 643     // We can have multiple :-separated pieces; there can be pieces both
 644     // before and after the mangled name. Find the first part that starts
 645     // with '_Z'; we'll assume that's the mangled name we want.
 646     std::pair<StringRef, StringRef> Parts = {StringRef(), Name};
 647     while (true) {
 648       Parts = Parts.second.split(':');
 649       if (Parts.first.startswith("_Z"))
 650         return Parts.first;
 651       if (Parts.second.empty())
 652         return Name;
 653     }
 654   }
 655
 656   /// Given a mangled name extracted from a PGO function name, and a new
 657   /// form for that mangled name, reconstitute the name.
 658   static void reconstituteName(StringRef OrigName, StringRef ExtractedName,
 659                                StringRef Replacement,
 660                                SmallVectorImpl<char> &Out) {
 661     Out.reserve(OrigName.size() + Replacement.size() - ExtractedName.size());
 662     Out.insert(Out.end(), OrigName.begin(), ExtractedName.begin());
 663     Out.insert(Out.end(), Replacement.begin(), Replacement.end());
 664     Out.insert(Out.end(), ExtractedName.end(), OrigName.end());
 665   }
 666
 667   Error populateRemappings() override {
 668     if (Error E = Remappings.read(*RemapBuffer))
 669       return E;
 670     for (StringRef Name : Underlying.HashTable->keys()) {
 671       StringRef RealName = extractName(Name);
 672       if (auto Key = Remappings.insert(RealName)) {
 673         // FIXME: We could theoretically map the same equivalence class to
 674         // multiple names in the profile data. If that happens, we should
 675         // return NamedInstrProfRecords from all of them.
 676         MappedNames.insert({Key, RealName});
 677       }
 678     }
 679     return Error::success();
 680   }
 681
 682   Error getRecords(StringRef FuncName,
 683                    ArrayRef<NamedInstrProfRecord> &Data) override {
 684     StringRef RealName = extractName(FuncName);
 685     if (auto Key = Remappings.lookup(RealName)) {
 686       StringRef Remapped = MappedNames.lookup(Key);
 687       if (!Remapped.empty()) {
 688         if (RealName.begin() == FuncName.begin() &&
 689             RealName.end() == FuncName.end())
 690           FuncName = Remapped;
 691         else {
 692           // Try rebuilding the name from the given remapping.
 693           SmallString<256> Reconstituted;
 694           reconstituteName(FuncName, RealName, Remapped, Reconstituted);
 695           Error E = Underlying.getRecords(Reconstituted, Data);
 696           if (!E)
 697             return E;
 698
 699           // If we failed because the name doesn't exist, fall back to asking
 700           // about the original name.
 701           if (Error Unhandled = handleErrors(
 702                   std::move(E), [](std::unique_ptr<InstrProfError> Err) {
 703                     return Err->get() == instrprof_error::unknown_function
 704                                ? Error::success()
 705                                : Error(std::move(Err));
 706                   }))
 707             return Unhandled;
 708         }
 709       }
 710     }
 711     return Underlying.getRecords(FuncName, Data);
 712   }
 713
 714 private:
 715   /// The memory buffer containing the remapping configuration. Remappings
 716   /// holds pointers into this buffer.
 717   std::unique_ptr<MemoryBuffer> RemapBuffer;
 718
 719   /// The mangling remapper.
 720   SymbolRemappingReader Remappings;
 721
 722   /// Mapping from mangled name keys to the name used for the key in the
 723   /// profile data.
 724   /// FIXME: Can we store a location within the on-disk hash table instead of
 725   /// redoing lookup?
 726   DenseMap<SymbolRemappingReader::Key, StringRef> MappedNames;
 727
 728   /// The real profile data reader.
 729   InstrProfReaderIndex<HashTableImpl> &Underlying;
 730 };
 731
 732 bool IndexedInstrProfReader::hasFormat(const MemoryBuffer &DataBuffer) {
 733   using namespace support;
 734
 735   if (DataBuffer.getBufferSize() < 8)
 736     return false;
 737   uint64_t Magic =
 738       endian::read<uint64_t, little, aligned>(DataBuffer.getBufferStart());
 739   // Verify that it's magical.
 740   return Magic == IndexedInstrProf::Magic;
 741 }
 742
 743 const unsigned char *
 744 IndexedInstrProfReader::readSummary(IndexedInstrProf::ProfVersion Version,
 745                                     const unsigned char *Cur, bool UseCS) {
 746   using namespace IndexedInstrProf;
 747   using namespace support;
 748
 749   if (Version >= IndexedInstrProf::Version4) {
 750     const IndexedInstrProf::Summary *SummaryInLE =
 751         reinterpret_cast<const IndexedInstrProf::Summary *>(Cur);
 752     uint64_t NFields =
 753         endian::byte_swap<uint64_t, little>(SummaryInLE->NumSummaryFields);
 754     uint64_t NEntries =
 755         endian::byte_swap<uint64_t, little>(SummaryInLE->NumCutoffEntries);
 756     uint32_t SummarySize =
 757         IndexedInstrProf::Summary::getSize(NFields, NEntries);
 758     std::unique_ptr<IndexedInstrProf::Summary> SummaryData =
 759         IndexedInstrProf::allocSummary(SummarySize);
 760
 761     const uint64_t *Src = reinterpret_cast<const uint64_t *>(SummaryInLE);
 762     uint64_t *Dst = reinterpret_cast<uint64_t *>(SummaryData.get());
 763     for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++)
 764       Dst[I] = endian::byte_swap<uint64_t, little>(Src[I]);
 765
 766     SummaryEntryVector DetailedSummary;
 767     for (unsigned I = 0; I < SummaryData->NumCutoffEntries; I++) {
 768       const IndexedInstrProf::Summary::Entry &Ent = SummaryData->getEntry(I);
 769       DetailedSummary.emplace_back((uint32_t)Ent.Cutoff, Ent.MinBlockCount,
 770                                    Ent.NumBlocks);
 771     }
 772     std::unique_ptr<llvm::ProfileSummary> &Summary =
 773         UseCS ? this->CS_Summary : this->Summary;
 774
 775     // initialize InstrProfSummary using the SummaryData from disk.
 776     Summary = std::make_unique<ProfileSummary>(
 777         UseCS ? ProfileSummary::PSK_CSInstr : ProfileSummary::PSK_Instr,
 778         DetailedSummary, SummaryData->get(Summary::TotalBlockCount),
 779         SummaryData->get(Summary::MaxBlockCount),
 780         SummaryData->get(Summary::MaxInternalBlockCount),
 781         SummaryData->get(Summary::MaxFunctionCount),
 782         SummaryData->get(Summary::TotalNumBlocks),
 783         SummaryData->get(Summary::TotalNumFunctions));
 784     return Cur + SummarySize;
 785   } else {
 786     // The older versions do not support a profile summary. This just computes
 787     // an empty summary, which will not result in accurate hot/cold detection.
 788     // We would need to call addRecord for all NamedInstrProfRecords to get the
 789     // correct summary. However, this version is old (prior to early 2016) and
 790     // has not been supporting an accurate summary for several years.
 791     InstrProfSummaryBuilder Builder(ProfileSummaryBuilder::DefaultCutoffs);
 792     Summary = Builder.getSummary();
 793     return Cur;
 794   }
 795 }
 796
 797 Error IndexedInstrProfReader::readHeader() {
 798   using namespace support;
 799
 800   const unsigned char *Start =
 801       (const unsigned char *)DataBuffer->getBufferStart();
 802   const unsigned char *Cur = Start;
 803   if ((const unsigned char *)DataBuffer->getBufferEnd() - Cur < 24)
 804     return error(instrprof_error::truncated);
 805
 806   auto *Header = reinterpret_cast<const IndexedInstrProf::Header *>(Cur);
 807   Cur += sizeof(IndexedInstrProf::Header);
 808
 809   // Check the magic number.
 810   uint64_t Magic = endian::byte_swap<uint64_t, little>(Header->Magic);
 811   if (Magic != IndexedInstrProf::Magic)
 812     return error(instrprof_error::bad_magic);
 813
 814   // Read the version.
 815   uint64_t FormatVersion = endian::byte_swap<uint64_t, little>(Header->Version);
 816   if (GET_VERSION(FormatVersion) >
 817       IndexedInstrProf::ProfVersion::CurrentVersion)
 818     return error(instrprof_error::unsupported_version);
 819
 820   Cur = readSummary((IndexedInstrProf::ProfVersion)FormatVersion, Cur,
 821                     /* UseCS */ false);
 822   if (FormatVersion & VARIANT_MASK_CSIR_PROF)
 823     Cur = readSummary((IndexedInstrProf::ProfVersion)FormatVersion, Cur,
 824                       /* UseCS */ true);
 825
 826   // Read the hash type and start offset.
 827   IndexedInstrProf::HashT HashType = static_cast<IndexedInstrProf::HashT>(
 828       endian::byte_swap<uint64_t, little>(Header->HashType));
 829   if (HashType > IndexedInstrProf::HashT::Last)
 830     return error(instrprof_error::unsupported_hash_type);
 831
 832   uint64_t HashOffset = endian::byte_swap<uint64_t, little>(Header->HashOffset);
 833
 834   // The rest of the file is an on disk hash table.
 835   auto IndexPtr =
 836       std::make_unique<InstrProfReaderIndex<OnDiskHashTableImplV3>>(
 837           Start + HashOffset, Cur, Start, HashType, FormatVersion);
 838
 839   // Load the remapping table now if requested.
 840   if (RemappingBuffer) {
 841     Remapper = std::make_unique<
 842         InstrProfReaderItaniumRemapper<OnDiskHashTableImplV3>>(
 843         std::move(RemappingBuffer), *IndexPtr);
 844     if (Error E = Remapper->populateRemappings())
 845       return E;
 846   } else {
 847     Remapper = std::make_unique<InstrProfReaderNullRemapper>(*IndexPtr);
 848   }
 849   Index = std::move(IndexPtr);
 850
 851   return success();
 852 }
 853
 854 InstrProfSymtab &IndexedInstrProfReader::getSymtab() {
 855   if (Symtab.get())
 856     return *Symtab.get();
 857
 858   std::unique_ptr<InstrProfSymtab> NewSymtab = std::make_unique<InstrProfSymtab>();
 859   if (Error E = Index->populateSymtab(*NewSymtab.get())) {
 860     consumeError(error(InstrProfError::take(std::move(E))));
 861   }
 862
 863   Symtab = std::move(NewSymtab);
 864   return *Symtab.get();
 865 }
 866
 867 Expected<InstrProfRecord>
 868 IndexedInstrProfReader::getInstrProfRecord(StringRef FuncName,
 869                                            uint64_t FuncHash) {
 870   ArrayRef<NamedInstrProfRecord> Data;
 871   Error Err = Remapper->getRecords(FuncName, Data);
 872   if (Err)
 873     return std::move(Err);
 874   // Found it. Look for counters with the right hash.
 875   for (unsigned I = 0, E = Data.size(); I < E; ++I) {
 876     // Check for a match and fill the vector if there is one.
 877     if (Data[I].Hash == FuncHash) {
 878       return std::move(Data[I]);
 879     }
 880   }
 881   return error(instrprof_error::hash_mismatch);
 882 }
 883
 884 Error IndexedInstrProfReader::getFunctionCounts(StringRef FuncName,
 885                                                 uint64_t FuncHash,
 886                                                 std::vector<uint64_t> &Counts) {
 887   Expected<InstrProfRecord> Record = getInstrProfRecord(FuncName, FuncHash);
 888   if (Error E = Record.takeError())
 889     return error(std::move(E));
 890
 891   Counts = Record.get().Counts;
 892   return success();
 893 }
 894
 895 Error IndexedInstrProfReader::readNextRecord(NamedInstrProfRecord &Record) {
 896   ArrayRef<NamedInstrProfRecord> Data;
 897
 898   Error E = Index->getRecords(Data);
 899   if (E)
 900     return error(std::move(E));
 901
 902   Record = Data[RecordIndex++];
 903   if (RecordIndex >= Data.size()) {
 904     Index->advanceToNextKey();
 905     RecordIndex = 0;
 906   }
 907   return success();
 908 }
 909
 910 void InstrProfReader::accumuateCounts(CountSumOrPercent &Sum, bool IsCS) {
 911   uint64_t NumFuncs = 0;
 912   for (const auto &Func : *this) {
 913     if (isIRLevelProfile()) {
 914       bool FuncIsCS = NamedInstrProfRecord::hasCSFlagInHash(Func.Hash);
 915       if (FuncIsCS != IsCS)
 916         continue;
 917     }
 918     Func.accumuateCounts(Sum);
 919     ++NumFuncs;
 920   }
 921   Sum.NumEntries = NumFuncs;
 922 }