summaryrefslogtreecommitdiff
path: root/lib/ProfileData/InstrProfReader.cpp
blob: 8d3ec5d2a3111b51b7a8669b02e72c1e4f7913b5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
//=-- InstrProfReader.cpp - Instrumented profiling reader -------------------=//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains support for reading profiling data for clang's
// instrumentation based PGO and coverage.
//
//===----------------------------------------------------------------------===//

#include "llvm/ProfileData/InstrProfReader.h"
#include "llvm/ProfileData/InstrProf.h"

#include "InstrProfIndexed.h"

#include <cassert>

using namespace llvm;
using std::error_code;

static error_code setupMemoryBuffer(std::string Path,
                                    std::unique_ptr<MemoryBuffer> &Buffer) {
  if (error_code EC = MemoryBuffer::getFileOrSTDIN(Path, Buffer))
    return EC;

  // Sanity check the file.
  if (Buffer->getBufferSize() > std::numeric_limits<unsigned>::max())
    return instrprof_error::too_large;
  return instrprof_error::success;
}

static error_code initializeReader(InstrProfReader &Reader) {
  return Reader.readHeader();
}

error_code InstrProfReader::create(std::string Path,
                                   std::unique_ptr<InstrProfReader> &Result) {
  // Set up the buffer to read.
  std::unique_ptr<MemoryBuffer> Buffer;
  if (error_code EC = setupMemoryBuffer(Path, Buffer))
    return EC;

  // Create the reader.
  if (IndexedInstrProfReader::hasFormat(*Buffer))
    Result.reset(new IndexedInstrProfReader(std::move(Buffer)));
  else if (RawInstrProfReader64::hasFormat(*Buffer))
    Result.reset(new RawInstrProfReader64(std::move(Buffer)));
  else if (RawInstrProfReader32::hasFormat(*Buffer))
    Result.reset(new RawInstrProfReader32(std::move(Buffer)));
  else
    Result.reset(new TextInstrProfReader(std::move(Buffer)));

  // Initialize the reader and return the result.
  return initializeReader(*Result);
}

error_code IndexedInstrProfReader::create(
    std::string Path, std::unique_ptr<IndexedInstrProfReader> &Result) {
  // Set up the buffer to read.
  std::unique_ptr<MemoryBuffer> Buffer;
  if (error_code EC = setupMemoryBuffer(Path, Buffer))
    return EC;

  // Create the reader.
  if (!IndexedInstrProfReader::hasFormat(*Buffer))
    return instrprof_error::bad_magic;
  Result.reset(new IndexedInstrProfReader(std::move(Buffer)));

  // Initialize the reader and return the result.
  return initializeReader(*Result);
}

void InstrProfIterator::Increment() {
  if (Reader->readNextRecord(Record))
    *this = InstrProfIterator();
}

error_code TextInstrProfReader::readNextRecord(InstrProfRecord &Record) {
  // Skip empty lines.
  while (!Line.is_at_end() && Line->empty())
    ++Line;
  // If we hit EOF while looking for a name, we're done.
  if (Line.is_at_end())
    return error(instrprof_error::eof);

  // Read the function name.
  Record.Name = *Line++;

  // Read the function hash.
  if (Line.is_at_end())
    return error(instrprof_error::truncated);
  if ((Line++)->getAsInteger(10, Record.Hash))
    return error(instrprof_error::malformed);

  // Read the number of counters.
  uint64_t NumCounters;
  if (Line.is_at_end())
    return error(instrprof_error::truncated);
  if ((Line++)->getAsInteger(10, NumCounters))
    return error(instrprof_error::malformed);
  if (NumCounters == 0)
    return error(instrprof_error::malformed);

  // Read each counter and fill our internal storage with the values.
  Counts.clear();
  Counts.reserve(NumCounters);
  for (uint64_t I = 0; I < NumCounters; ++I) {
    if (Line.is_at_end())
      return error(instrprof_error::truncated);
    uint64_t Count;
    if ((Line++)->getAsInteger(10, Count))
      return error(instrprof_error::malformed);
    Counts.push_back(Count);
  }
  // Give the record a reference to our internal counter storage.
  Record.Counts = Counts;

  return success();
}

template <class IntPtrT>
static uint64_t getRawMagic();

template <>
uint64_t getRawMagic<uint64_t>() {
  return
    uint64_t(255) << 56 |
    uint64_t('l') << 48 |
    uint64_t('p') << 40 |
    uint64_t('r') << 32 |
    uint64_t('o') << 24 |
    uint64_t('f') << 16 |
    uint64_t('r') <<  8 |
    uint64_t(129);
}

template <>
uint64_t getRawMagic<uint32_t>() {
  return
    uint64_t(255) << 56 |
    uint64_t('l') << 48 |
    uint64_t('p') << 40 |
    uint64_t('r') << 32 |
    uint64_t('o') << 24 |
    uint64_t('f') << 16 |
    uint64_t('R') <<  8 |
    uint64_t(129);
}

template <class IntPtrT>
bool RawInstrProfReader<IntPtrT>::hasFormat(const MemoryBuffer &DataBuffer) {
  if (DataBuffer.getBufferSize() < sizeof(uint64_t))
    return false;
  uint64_t Magic =
    *reinterpret_cast<const uint64_t *>(DataBuffer.getBufferStart());
  return getRawMagic<IntPtrT>() == Magic ||
    sys::SwapByteOrder(getRawMagic<IntPtrT>()) == Magic;
}

template <class IntPtrT>
error_code RawInstrProfReader<IntPtrT>::readHeader() {
  if (!hasFormat(*DataBuffer))
    return error(instrprof_error::bad_magic);
  if (DataBuffer->getBufferSize() < sizeof(RawHeader))
    return error(instrprof_error::bad_header);
  auto *Header =
    reinterpret_cast<const RawHeader *>(DataBuffer->getBufferStart());
  ShouldSwapBytes = Header->Magic != getRawMagic<IntPtrT>();
  return readHeader(*Header);
}

template <class IntPtrT>
error_code RawInstrProfReader<IntPtrT>::readNextHeader(const char *CurrentPos) {
  const char *End = DataBuffer->getBufferEnd();
  // Skip zero padding between profiles.
  while (CurrentPos != End && *CurrentPos == 0)
    ++CurrentPos;
  // If there's nothing left, we're done.
  if (CurrentPos == End)
    return instrprof_error::eof;
  // If there isn't enough space for another header, this is probably just
  // garbage at the end of the file.
  if (CurrentPos + sizeof(RawHeader) > End)
    return instrprof_error::malformed;
  // The magic should have the same byte order as in the previous header.
  uint64_t Magic = *reinterpret_cast<const uint64_t *>(CurrentPos);
  if (Magic != swap(getRawMagic<IntPtrT>()))
    return instrprof_error::bad_magic;

  // There's another profile to read, so we need to process the header.
  auto *Header = reinterpret_cast<const RawHeader *>(CurrentPos);
  return readHeader(*Header);
}

static uint64_t getRawVersion() {
  return 1;
}

template <class IntPtrT>
error_code RawInstrProfReader<IntPtrT>::readHeader(const RawHeader &Header) {
  if (swap(Header.Version) != getRawVersion())
    return error(instrprof_error::unsupported_version);

  CountersDelta = swap(Header.CountersDelta);
  NamesDelta = swap(Header.NamesDelta);
  auto DataSize = swap(Header.DataSize);
  auto CountersSize = swap(Header.CountersSize);
  auto NamesSize = swap(Header.NamesSize);

  ptrdiff_t DataOffset = sizeof(RawHeader);
  ptrdiff_t CountersOffset = DataOffset + sizeof(ProfileData) * DataSize;
  ptrdiff_t NamesOffset = CountersOffset + sizeof(uint64_t) * CountersSize;
  size_t ProfileSize = NamesOffset + sizeof(char) * NamesSize;

  auto *Start = reinterpret_cast<const char *>(&Header);
  if (Start + ProfileSize > DataBuffer->getBufferEnd())
    return error(instrprof_error::bad_header);

  Data = reinterpret_cast<const ProfileData *>(Start + DataOffset);
  DataEnd = Data + DataSize;
  CountersStart = reinterpret_cast<const uint64_t *>(Start + CountersOffset);
  NamesStart = Start + NamesOffset;
  ProfileEnd = Start + ProfileSize;

  return success();
}

template <class IntPtrT>
error_code
RawInstrProfReader<IntPtrT>::readNextRecord(InstrProfRecord &Record) {
  if (Data == DataEnd)
    if (error_code EC = readNextHeader(ProfileEnd))
      return EC;

  // Get the raw data.
  StringRef RawName(getName(Data->NamePtr), swap(Data->NameSize));
  uint32_t NumCounters = swap(Data->NumCounters);
  if (NumCounters == 0)
    return error(instrprof_error::malformed);
  auto RawCounts = makeArrayRef(getCounter(Data->CounterPtr), NumCounters);

  // Check bounds.
  auto *NamesStartAsCounter = reinterpret_cast<const uint64_t *>(NamesStart);
  if (RawName.data() < NamesStart ||
      RawName.data() + RawName.size() > DataBuffer->getBufferEnd() ||
      RawCounts.data() < CountersStart ||
      RawCounts.data() + RawCounts.size() > NamesStartAsCounter)
    return error(instrprof_error::malformed);

  // Store the data in Record, byte-swapping as necessary.
  Record.Hash = swap(Data->FuncHash);
  Record.Name = RawName;
  if (ShouldSwapBytes) {
    Counts.clear();
    Counts.reserve(RawCounts.size());
    for (uint64_t Count : RawCounts)
      Counts.push_back(swap(Count));
    Record.Counts = Counts;
  } else
    Record.Counts = RawCounts;

  // Iterate.
  ++Data;
  return success();
}

namespace llvm {
template class RawInstrProfReader<uint32_t>;
template class RawInstrProfReader<uint64_t>;
}

InstrProfLookupTrait::hash_value_type
InstrProfLookupTrait::ComputeHash(StringRef K) {
  return IndexedInstrProf::ComputeHash(HashType, K);
}

bool IndexedInstrProfReader::hasFormat(const MemoryBuffer &DataBuffer) {
  if (DataBuffer.getBufferSize() < 8)
    return false;
  using namespace support;
  uint64_t Magic =
      endian::read<uint64_t, little, aligned>(DataBuffer.getBufferStart());
  return Magic == IndexedInstrProf::Magic;
}

error_code IndexedInstrProfReader::readHeader() {
  const unsigned char *Start =
      (const unsigned char *)DataBuffer->getBufferStart();
  const unsigned char *Cur = Start;
  if ((const unsigned char *)DataBuffer->getBufferEnd() - Cur < 24)
    return error(instrprof_error::truncated);

  using namespace support;

  // Check the magic number.
  uint64_t Magic = endian::readNext<uint64_t, little, unaligned>(Cur);
  if (Magic != IndexedInstrProf::Magic)
    return error(instrprof_error::bad_magic);

  // Read the version.
  uint64_t Version = endian::readNext<uint64_t, little, unaligned>(Cur);
  if (Version != IndexedInstrProf::Version)
    return error(instrprof_error::unsupported_version);

  // Read the maximal function count.
  MaxFunctionCount = endian::readNext<uint64_t, little, unaligned>(Cur);

  // Read the hash type and start offset.
  IndexedInstrProf::HashT HashType = static_cast<IndexedInstrProf::HashT>(
      endian::readNext<uint64_t, little, unaligned>(Cur));
  if (HashType > IndexedInstrProf::HashT::Last)
    return error(instrprof_error::unsupported_hash_type);
  uint64_t HashOffset = endian::readNext<uint64_t, little, unaligned>(Cur);

  // The rest of the file is an on disk hash table.
  Index.reset(InstrProfReaderIndex::Create(Start + HashOffset, Cur, Start,
                                           InstrProfLookupTrait(HashType)));
  // Set up our iterator for readNextRecord.
  RecordIterator = Index->data_begin();

  return success();
}

error_code IndexedInstrProfReader::getFunctionCounts(
    StringRef FuncName, uint64_t &FuncHash, std::vector<uint64_t> &Counts) {
  const auto &Iter = Index->find(FuncName);
  if (Iter == Index->end())
    return error(instrprof_error::unknown_function);

  // Found it. Make sure it's valid before giving back a result.
  const InstrProfRecord &Record = *Iter;
  if (Record.Name.empty())
    return error(instrprof_error::malformed);
  FuncHash = Record.Hash;
  Counts = Record.Counts;
  return success();
}

error_code IndexedInstrProfReader::readNextRecord(InstrProfRecord &Record) {
  // Are we out of records?
  if (RecordIterator == Index->data_end())
    return error(instrprof_error::eof);

  // Read the next one.
  Record = *RecordIterator;
  ++RecordIterator;
  if (Record.Name.empty())
    return error(instrprof_error::malformed);
  return success();
}