include/llvm/ProfileData/InstrProfReader.h

   1 //===- InstrProfReader.h - Instrumented profiling readers -------*- C++ -*-===//
   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 instrumentation
  10 // based PGO and coverage.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_PROFILEDATA_INSTRPROFREADER_H
  15 #define LLVM_PROFILEDATA_INSTRPROFREADER_H
  16
  17 #include "llvm/ADT/ArrayRef.h"
  18 #include "llvm/ADT/StringRef.h"
  19 #include "llvm/IR/ProfileSummary.h"
  20 #include "llvm/ProfileData/InstrProf.h"
  21 #include "llvm/Support/Endian.h"
  22 #include "llvm/Support/Error.h"
  23 #include "llvm/Support/LineIterator.h"
  24 #include "llvm/Support/MemoryBuffer.h"
  25 #include "llvm/Support/OnDiskHashTable.h"
  26 #include "llvm/Support/SwapByteOrder.h"
  27 #include <algorithm>
  28 #include <cassert>
  29 #include <cstddef>
  30 #include <cstdint>
  31 #include <iterator>
  32 #include <memory>
  33 #include <utility>
  34 #include <vector>
  35
  36 namespace llvm {
  37
  38 class InstrProfReader;
  39
  40 /// A file format agnostic iterator over profiling data.
  41 class InstrProfIterator : public std::iterator<std::input_iterator_tag,
  42                                                NamedInstrProfRecord> {
  43   InstrProfReader *Reader = nullptr;
  44   value_type Record;
  45
  46   void Increment();
  47
  48 public:
  49   InstrProfIterator() = default;
  50   InstrProfIterator(InstrProfReader *Reader) : Reader(Reader) { Increment(); }
  51
  52   InstrProfIterator &operator++() { Increment(); return *this; }
  53   bool operator==(const InstrProfIterator &RHS) { return Reader == RHS.Reader; }
  54   bool operator!=(const InstrProfIterator &RHS) { return Reader != RHS.Reader; }
  55   value_type &operator*() { return Record; }
  56   value_type *operator->() { return &Record; }
  57 };
  58
  59 /// Base class and interface for reading profiling data of any known instrprof
  60 /// format. Provides an iterator over NamedInstrProfRecords.
  61 class InstrProfReader {
  62   instrprof_error LastError = instrprof_error::success;
  63
  64 public:
  65   InstrProfReader() = default;
  66   virtual ~InstrProfReader() = default;
  67
  68   /// Read the header.  Required before reading first record.
  69   virtual Error readHeader() = 0;
  70
  71   /// Read a single record.
  72   virtual Error readNextRecord(NamedInstrProfRecord &Record) = 0;
  73
  74   /// Iterator over profile data.
  75   InstrProfIterator begin() { return InstrProfIterator(this); }
  76   InstrProfIterator end() { return InstrProfIterator(); }
  77
  78   virtual bool isIRLevelProfile() const = 0;
  79
  80   virtual bool hasCSIRLevelProfile() const = 0;
  81
  82   /// Return the PGO symtab. There are three different readers:
  83   /// Raw, Text, and Indexed profile readers. The first two types
  84   /// of readers are used only by llvm-profdata tool, while the indexed
  85   /// profile reader is also used by llvm-cov tool and the compiler (
  86   /// backend or frontend). Since creating PGO symtab can create
  87   /// significant runtime and memory overhead (as it touches data
  88   /// for the whole program), InstrProfSymtab for the indexed profile
  89   /// reader should be created on demand and it is recommended to be
  90   /// only used for dumping purpose with llvm-proftool, not with the
  91   /// compiler.
  92   virtual InstrProfSymtab &getSymtab() = 0;
  93
  94   /// Compute the sum of counts and return in Sum.
  95   void accumulateCounts(CountSumOrPercent &Sum, bool IsCS);
  96
  97 protected:
  98   std::unique_ptr<InstrProfSymtab> Symtab;
  99
 100   /// Set the current error and return same.
 101   Error error(instrprof_error Err) {
 102     LastError = Err;
 103     if (Err == instrprof_error::success)
 104       return Error::success();
 105     return make_error<InstrProfError>(Err);
 106   }
 107
 108   Error error(Error &&E) { return error(InstrProfError::take(std::move(E))); }
 109
 110   /// Clear the current error and return a successful one.
 111   Error success() { return error(instrprof_error::success); }
 112
 113 public:
 114   /// Return true if the reader has finished reading the profile data.
 115   bool isEOF() { return LastError == instrprof_error::eof; }
 116
 117   /// Return true if the reader encountered an error reading profiling data.
 118   bool hasError() { return LastError != instrprof_error::success && !isEOF(); }
 119
 120   /// Get the current error.
 121   Error getError() {
 122     if (hasError())
 123       return make_error<InstrProfError>(LastError);
 124     return Error::success();
 125   }
 126
 127   /// Factory method to create an appropriately typed reader for the given
 128   /// instrprof file.
 129   static Expected<std::unique_ptr<InstrProfReader>> create(const Twine &Path);
 130
 131   static Expected<std::unique_ptr<InstrProfReader>>
 132   create(std::unique_ptr<MemoryBuffer> Buffer);
 133 };
 134
 135 /// Reader for the simple text based instrprof format.
 136 ///
 137 /// This format is a simple text format that's suitable for test data. Records
 138 /// are separated by one or more blank lines, and record fields are separated by
 139 /// new lines.
 140 ///
 141 /// Each record consists of a function name, a function hash, a number of
 142 /// counters, and then each counter value, in that order.
 143 class TextInstrProfReader : public InstrProfReader {
 144 private:
 145   /// The profile data file contents.
 146   std::unique_ptr<MemoryBuffer> DataBuffer;
 147   /// Iterator over the profile data.
 148   line_iterator Line;
 149   bool IsIRLevelProfile = false;
 150   bool HasCSIRLevelProfile = false;
 151
 152   Error readValueProfileData(InstrProfRecord &Record);
 153
 154 public:
 155   TextInstrProfReader(std::unique_ptr<MemoryBuffer> DataBuffer_)
 156       : DataBuffer(std::move(DataBuffer_)), Line(*DataBuffer, true, '#') {}
 157   TextInstrProfReader(const TextInstrProfReader &) = delete;
 158   TextInstrProfReader &operator=(const TextInstrProfReader &) = delete;
 159
 160   /// Return true if the given buffer is in text instrprof format.
 161   static bool hasFormat(const MemoryBuffer &Buffer);
 162
 163   bool isIRLevelProfile() const override { return IsIRLevelProfile; }
 164
 165   bool hasCSIRLevelProfile() const override { return HasCSIRLevelProfile; }
 166
 167   /// Read the header.
 168   Error readHeader() override;
 169
 170   /// Read a single record.
 171   Error readNextRecord(NamedInstrProfRecord &Record) override;
 172
 173   InstrProfSymtab &getSymtab() override {
 174     assert(Symtab.get());
 175     return *Symtab.get();
 176   }
 177 };
 178
 179 /// Reader for the raw instrprof binary format from runtime.
 180 ///
 181 /// This format is a raw memory dump of the instrumentation-baed profiling data
 182 /// from the runtime.  It has no index.
 183 ///
 184 /// Templated on the unsigned type whose size matches pointers on the platform
 185 /// that wrote the profile.
 186 template <class IntPtrT>
 187 class RawInstrProfReader : public InstrProfReader {
 188 private:
 189   /// The profile data file contents.
 190   std::unique_ptr<MemoryBuffer> DataBuffer;
 191   bool ShouldSwapBytes;
 192   // The value of the version field of the raw profile data header. The lower 56
 193   // bits specifies the format version and the most significant 8 bits specify
 194   // the variant types of the profile.
 195   uint64_t Version;
 196   uint64_t CountersDelta;
 197   uint64_t NamesDelta;
 198   const RawInstrProf::ProfileData<IntPtrT> *Data;
 199   const RawInstrProf::ProfileData<IntPtrT> *DataEnd;
 200   const uint64_t *CountersStart;
 201   const char *NamesStart;
 202   uint64_t NamesSize;
 203   // After value profile is all read, this pointer points to
 204   // the header of next profile data (if exists)
 205   const uint8_t *ValueDataStart;
 206   uint32_t ValueKindLast;
 207   uint32_t CurValueDataSize;
 208
 209 public:
 210   RawInstrProfReader(std::unique_ptr<MemoryBuffer> DataBuffer)
 211       : DataBuffer(std::move(DataBuffer)) {}
 212   RawInstrProfReader(const RawInstrProfReader &) = delete;
 213   RawInstrProfReader &operator=(const RawInstrProfReader &) = delete;
 214
 215   static bool hasFormat(const MemoryBuffer &DataBuffer);
 216   Error readHeader() override;
 217   Error readNextRecord(NamedInstrProfRecord &Record) override;
 218
 219   bool isIRLevelProfile() const override {
 220     return (Version & VARIANT_MASK_IR_PROF) != 0;
 221   }
 222
 223   bool hasCSIRLevelProfile() const override {
 224     return (Version & VARIANT_MASK_CSIR_PROF) != 0;
 225   }
 226
 227   InstrProfSymtab &getSymtab() override {
 228     assert(Symtab.get());
 229     return *Symtab.get();
 230   }
 231
 232 private:
 233   Error createSymtab(InstrProfSymtab &Symtab);
 234   Error readNextHeader(const char *CurrentPos);
 235   Error readHeader(const RawInstrProf::Header &Header);
 236
 237   template <class IntT> IntT swap(IntT Int) const {
 238     return ShouldSwapBytes ? sys::getSwappedBytes(Int) : Int;
 239   }
 240
 241   support::endianness getDataEndianness() const {
 242     support::endianness HostEndian = getHostEndianness();
 243     if (!ShouldSwapBytes)
 244       return HostEndian;
 245     if (HostEndian == support::little)
 246       return support::big;
 247     else
 248       return support::little;
 249   }
 250
 251   inline uint8_t getNumPaddingBytes(uint64_t SizeInBytes) {
 252     return 7 & (sizeof(uint64_t) - SizeInBytes % sizeof(uint64_t));
 253   }
 254
 255   Error readName(NamedInstrProfRecord &Record);
 256   Error readFuncHash(NamedInstrProfRecord &Record);
 257   Error readRawCounts(InstrProfRecord &Record);
 258   Error readValueProfilingData(InstrProfRecord &Record);
 259   bool atEnd() const { return Data == DataEnd; }
 260
 261   void advanceData() {
 262     Data++;
 263     ValueDataStart += CurValueDataSize;
 264   }
 265
 266   const char *getNextHeaderPos() const {
 267       assert(atEnd());
 268       return (const char *)ValueDataStart;
 269   }
 270
 271   /// Get the offset of \p CounterPtr from the start of the counters section of
 272   /// the profile. The offset has units of "number of counters", i.e. increasing
 273   /// the offset by 1 corresponds to an increase in the *byte offset* by 8.
 274   ptrdiff_t getCounterOffset(IntPtrT CounterPtr) const {
 275     return (swap(CounterPtr) - CountersDelta) / sizeof(uint64_t);
 276   }
 277
 278   const uint64_t *getCounter(ptrdiff_t Offset) const {
 279     return CountersStart + Offset;
 280   }
 281
 282   StringRef getName(uint64_t NameRef) const {
 283     return Symtab->getFuncName(swap(NameRef));
 284   }
 285 };
 286
 287 using RawInstrProfReader32 = RawInstrProfReader<uint32_t>;
 288 using RawInstrProfReader64 = RawInstrProfReader<uint64_t>;
 289
 290 namespace IndexedInstrProf {
 291
 292 enum class HashT : uint32_t;
 293
 294 } // end namespace IndexedInstrProf
 295
 296 /// Trait for lookups into the on-disk hash table for the binary instrprof
 297 /// format.
 298 class InstrProfLookupTrait {
 299   std::vector<NamedInstrProfRecord> DataBuffer;
 300   IndexedInstrProf::HashT HashType;
 301   unsigned FormatVersion;
 302   // Endianness of the input value profile data.
 303   // It should be LE by default, but can be changed
 304   // for testing purpose.
 305   support::endianness ValueProfDataEndianness = support::little;
 306
 307 public:
 308   InstrProfLookupTrait(IndexedInstrProf::HashT HashType, unsigned FormatVersion)
 309       : HashType(HashType), FormatVersion(FormatVersion) {}
 310
 311   using data_type = ArrayRef<NamedInstrProfRecord>;
 312
 313   using internal_key_type = StringRef;
 314   using external_key_type = StringRef;
 315   using hash_value_type = uint64_t;
 316   using offset_type = uint64_t;
 317
 318   static bool EqualKey(StringRef A, StringRef B) { return A == B; }
 319   static StringRef GetInternalKey(StringRef K) { return K; }
 320   static StringRef GetExternalKey(StringRef K) { return K; }
 321
 322   hash_value_type ComputeHash(StringRef K);
 323
 324   static std::pair<offset_type, offset_type>
 325   ReadKeyDataLength(const unsigned char *&D) {
 326     using namespace support;
 327
 328     offset_type KeyLen = endian::readNext<offset_type, little, unaligned>(D);
 329     offset_type DataLen = endian::readNext<offset_type, little, unaligned>(D);
 330     return std::make_pair(KeyLen, DataLen);
 331   }
 332
 333   StringRef ReadKey(const unsigned char *D, offset_type N) {
 334     return StringRef((const char *)D, N);
 335   }
 336
 337   bool readValueProfilingData(const unsigned char *&D,
 338                               const unsigned char *const End);
 339   data_type ReadData(StringRef K, const unsigned char *D, offset_type N);
 340
 341   // Used for testing purpose only.
 342   void setValueProfDataEndianness(support::endianness Endianness) {
 343     ValueProfDataEndianness = Endianness;
 344   }
 345 };
 346
 347 struct InstrProfReaderIndexBase {
 348   virtual ~InstrProfReaderIndexBase() = default;
 349
 350   // Read all the profile records with the same key pointed to the current
 351   // iterator.
 352   virtual Error getRecords(ArrayRef<NamedInstrProfRecord> &Data) = 0;
 353
 354   // Read all the profile records with the key equal to FuncName
 355   virtual Error getRecords(StringRef FuncName,
 356                                      ArrayRef<NamedInstrProfRecord> &Data) = 0;
 357   virtual void advanceToNextKey() = 0;
 358   virtual bool atEnd() const = 0;
 359   virtual void setValueProfDataEndianness(support::endianness Endianness) = 0;
 360   virtual uint64_t getVersion() const = 0;
 361   virtual bool isIRLevelProfile() const = 0;
 362   virtual bool hasCSIRLevelProfile() const = 0;
 363   virtual Error populateSymtab(InstrProfSymtab &) = 0;
 364 };
 365
 366 using OnDiskHashTableImplV3 =
 367     OnDiskIterableChainedHashTable<InstrProfLookupTrait>;
 368
 369 template <typename HashTableImpl>
 370 class InstrProfReaderItaniumRemapper;
 371
 372 template <typename HashTableImpl>
 373 class InstrProfReaderIndex : public InstrProfReaderIndexBase {
 374 private:
 375   std::unique_ptr<HashTableImpl> HashTable;
 376   typename HashTableImpl::data_iterator RecordIterator;
 377   uint64_t FormatVersion;
 378
 379   friend class InstrProfReaderItaniumRemapper<HashTableImpl>;
 380
 381 public:
 382   InstrProfReaderIndex(const unsigned char *Buckets,
 383                        const unsigned char *const Payload,
 384                        const unsigned char *const Base,
 385                        IndexedInstrProf::HashT HashType, uint64_t Version);
 386   ~InstrProfReaderIndex() override = default;
 387
 388   Error getRecords(ArrayRef<NamedInstrProfRecord> &Data) override;
 389   Error getRecords(StringRef FuncName,
 390                    ArrayRef<NamedInstrProfRecord> &Data) override;
 391   void advanceToNextKey() override { RecordIterator++; }
 392
 393   bool atEnd() const override {
 394     return RecordIterator == HashTable->data_end();
 395   }
 396
 397   void setValueProfDataEndianness(support::endianness Endianness) override {
 398     HashTable->getInfoObj().setValueProfDataEndianness(Endianness);
 399   }
 400
 401   uint64_t getVersion() const override { return GET_VERSION(FormatVersion); }
 402
 403   bool isIRLevelProfile() const override {
 404     return (FormatVersion & VARIANT_MASK_IR_PROF) != 0;
 405   }
 406
 407   bool hasCSIRLevelProfile() const override {
 408     return (FormatVersion & VARIANT_MASK_CSIR_PROF) != 0;
 409   }
 410
 411   Error populateSymtab(InstrProfSymtab &Symtab) override {
 412     return Symtab.create(HashTable->keys());
 413   }
 414 };
 415
 416 /// Name matcher supporting fuzzy matching of symbol names to names in profiles.
 417 class InstrProfReaderRemapper {
 418 public:
 419   virtual ~InstrProfReaderRemapper() {}
 420   virtual Error populateRemappings() { return Error::success(); }
 421   virtual Error getRecords(StringRef FuncName,
 422                            ArrayRef<NamedInstrProfRecord> &Data) = 0;
 423 };
 424
 425 /// Reader for the indexed binary instrprof format.
 426 class IndexedInstrProfReader : public InstrProfReader {
 427 private:
 428   /// The profile data file contents.
 429   std::unique_ptr<MemoryBuffer> DataBuffer;
 430   /// The profile remapping file contents.
 431   std::unique_ptr<MemoryBuffer> RemappingBuffer;
 432   /// The index into the profile data.
 433   std::unique_ptr<InstrProfReaderIndexBase> Index;
 434   /// The profile remapping file contents.
 435   std::unique_ptr<InstrProfReaderRemapper> Remapper;
 436   /// Profile summary data.
 437   std::unique_ptr<ProfileSummary> Summary;
 438   /// Context sensitive profile summary data.
 439   std::unique_ptr<ProfileSummary> CS_Summary;
 440   // Index to the current record in the record array.
 441   unsigned RecordIndex;
 442
 443   // Read the profile summary. Return a pointer pointing to one byte past the
 444   // end of the summary data if it exists or the input \c Cur.
 445   // \c UseCS indicates whether to use the context-sensitive profile summary.
 446   const unsigned char *readSummary(IndexedInstrProf::ProfVersion Version,
 447                                    const unsigned char *Cur, bool UseCS);
 448
 449 public:
 450   IndexedInstrProfReader(
 451       std::unique_ptr<MemoryBuffer> DataBuffer,
 452       std::unique_ptr<MemoryBuffer> RemappingBuffer = nullptr)
 453       : DataBuffer(std::move(DataBuffer)),
 454         RemappingBuffer(std::move(RemappingBuffer)), RecordIndex(0) {}
 455   IndexedInstrProfReader(const IndexedInstrProfReader &) = delete;
 456   IndexedInstrProfReader &operator=(const IndexedInstrProfReader &) = delete;
 457
 458   /// Return the profile version.
 459   uint64_t getVersion() const { return Index->getVersion(); }
 460   bool isIRLevelProfile() const override { return Index->isIRLevelProfile(); }
 461   bool hasCSIRLevelProfile() const override {
 462     return Index->hasCSIRLevelProfile();
 463   }
 464
 465   /// Return true if the given buffer is in an indexed instrprof format.
 466   static bool hasFormat(const MemoryBuffer &DataBuffer);
 467
 468   /// Read the file header.
 469   Error readHeader() override;
 470   /// Read a single record.
 471   Error readNextRecord(NamedInstrProfRecord &Record) override;
 472
 473   /// Return the NamedInstrProfRecord associated with FuncName and FuncHash
 474   Expected<InstrProfRecord> getInstrProfRecord(StringRef FuncName,
 475                                                uint64_t FuncHash);
 476
 477   /// Fill Counts with the profile data for the given function name.
 478   Error getFunctionCounts(StringRef FuncName, uint64_t FuncHash,
 479                           std::vector<uint64_t> &Counts);
 480
 481   /// Return the maximum of all known function counts.
 482   /// \c UseCS indicates whether to use the context-sensitive count.
 483   uint64_t getMaximumFunctionCount(bool UseCS) {
 484     if (UseCS) {
 485       assert(CS_Summary && "No context sensitive profile summary");
 486       return CS_Summary->getMaxFunctionCount();
 487     } else {
 488       assert(Summary && "No profile summary");
 489       return Summary->getMaxFunctionCount();
 490     }
 491   }
 492
 493   /// Factory method to create an indexed reader.
 494   static Expected<std::unique_ptr<IndexedInstrProfReader>>
 495   create(const Twine &Path, const Twine &RemappingPath = "");
 496
 497   static Expected<std::unique_ptr<IndexedInstrProfReader>>
 498   create(std::unique_ptr<MemoryBuffer> Buffer,
 499          std::unique_ptr<MemoryBuffer> RemappingBuffer = nullptr);
 500
 501   // Used for testing purpose only.
 502   void setValueProfDataEndianness(support::endianness Endianness) {
 503     Index->setValueProfDataEndianness(Endianness);
 504   }
 505
 506   // See description in the base class. This interface is designed
 507   // to be used by llvm-profdata (for dumping). Avoid using this when
 508   // the client is the compiler.
 509   InstrProfSymtab &getSymtab() override;
 510
 511   /// Return the profile summary.
 512   /// \c UseCS indicates whether to use the context-sensitive summary.
 513   ProfileSummary &getSummary(bool UseCS) {
 514     if (UseCS) {
 515       assert(CS_Summary && "No context sensitive summary");
 516       return *(CS_Summary.get());
 517     } else {
 518       assert(Summary && "No profile summary");
 519       return *(Summary.get());
 520     }
 521   }
 522 };
 523
 524 } // end namespace llvm
 525
 526 #endif // LLVM_PROFILEDATA_INSTRPROFREADER_H