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