lib/ProfileData/InstrProfReader.cpp

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