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/StringExtras.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>>
setupMemoryBuffer(const Twine & Path)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
initializeReader(InstrProfReader & Reader)50 static Error initializeReader(InstrProfReader &Reader) {
51 return Reader.readHeader();
52 }
53
54 Expected<std::unique_ptr<InstrProfReader>>
create(const Twine & Path)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>>
create(std::unique_ptr<MemoryBuffer> Buffer)64 InstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
65 // Sanity check the buffer.
66 if (uint64_t(Buffer->getBufferSize()) > std::numeric_limits<uint64_t>::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>>
create(const Twine & Path,const Twine & RemappingPath)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>>
create(std::unique_ptr<MemoryBuffer> Buffer,std::unique_ptr<MemoryBuffer> RemappingBuffer)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<uint64_t>::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 = std::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
Increment()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
hasFormat(const MemoryBuffer & Buffer)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.
readHeader()154 Error TextInstrProfReader::readHeader() {
155 Symtab.reset(new InstrProfSymtab());
156 bool IsIRInstr = false;
157 bool IsEntryFirst = false;
158 bool IsCS = false;
159
160 while (Line->startswith(":")) {
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 if (Str.equals_lower("csir")) {
167 IsIRInstr = true;
168 IsCS = true;
169 } else if (Str.equals_lower("entry_first"))
170 IsEntryFirst = true;
171 else if (Str.equals_lower("not_entry_first"))
172 IsEntryFirst = false;
173 else
174 return error(instrprof_error::bad_header);
175 ++Line;
176 }
177 IsIRLevelProfile = IsIRInstr;
178 InstrEntryBBEnabled = IsEntryFirst;
179 HasCSIRLevelProfile = IsCS;
180 return success();
181 }
182
183 Error
readValueProfileData(InstrProfRecord & Record)184 TextInstrProfReader::readValueProfileData(InstrProfRecord &Record) {
185
186 #define CHECK_LINE_END(Line) \
187 if (Line.is_at_end()) \
188 return error(instrprof_error::truncated);
189 #define READ_NUM(Str, Dst) \
190 if ((Str).getAsInteger(10, (Dst))) \
191 return error(instrprof_error::malformed);
192 #define VP_READ_ADVANCE(Val) \
193 CHECK_LINE_END(Line); \
194 uint32_t Val; \
195 READ_NUM((*Line), (Val)); \
196 Line++;
197
198 if (Line.is_at_end())
199 return success();
200
201 uint32_t NumValueKinds;
202 if (Line->getAsInteger(10, NumValueKinds)) {
203 // No value profile data
204 return success();
205 }
206 if (NumValueKinds == 0 || NumValueKinds > IPVK_Last + 1)
207 return error(instrprof_error::malformed);
208 Line++;
209
210 for (uint32_t VK = 0; VK < NumValueKinds; VK++) {
211 VP_READ_ADVANCE(ValueKind);
212 if (ValueKind > IPVK_Last)
213 return error(instrprof_error::malformed);
214 VP_READ_ADVANCE(NumValueSites);
215 if (!NumValueSites)
216 continue;
217
218 Record.reserveSites(VK, NumValueSites);
219 for (uint32_t S = 0; S < NumValueSites; S++) {
220 VP_READ_ADVANCE(NumValueData);
221
222 std::vector<InstrProfValueData> CurrentValues;
223 for (uint32_t V = 0; V < NumValueData; V++) {
224 CHECK_LINE_END(Line);
225 std::pair<StringRef, StringRef> VD = Line->rsplit(':');
226 uint64_t TakenCount, Value;
227 if (ValueKind == IPVK_IndirectCallTarget) {
228 if (InstrProfSymtab::isExternalSymbol(VD.first)) {
229 Value = 0;
230 } else {
231 if (Error E = Symtab->addFuncName(VD.first))
232 return E;
233 Value = IndexedInstrProf::ComputeHash(VD.first);
234 }
235 } else {
236 READ_NUM(VD.first, Value);
237 }
238 READ_NUM(VD.second, TakenCount);
239 CurrentValues.push_back({Value, TakenCount});
240 Line++;
241 }
242 Record.addValueData(ValueKind, S, CurrentValues.data(), NumValueData,
243 nullptr);
244 }
245 }
246 return success();
247
248 #undef CHECK_LINE_END
249 #undef READ_NUM
250 #undef VP_READ_ADVANCE
251 }
252
readNextRecord(NamedInstrProfRecord & Record)253 Error TextInstrProfReader::readNextRecord(NamedInstrProfRecord &Record) {
254 // Skip empty lines and comments.
255 while (!Line.is_at_end() && (Line->empty() || Line->startswith("#")))
256 ++Line;
257 // If we hit EOF while looking for a name, we're done.
258 if (Line.is_at_end()) {
259 return error(instrprof_error::eof);
260 }
261
262 // Read the function name.
263 Record.Name = *Line++;
264 if (Error E = Symtab->addFuncName(Record.Name))
265 return error(std::move(E));
266
267 // Read the function hash.
268 if (Line.is_at_end())
269 return error(instrprof_error::truncated);
270 if ((Line++)->getAsInteger(0, Record.Hash))
271 return error(instrprof_error::malformed);
272
273 // Read the number of counters.
274 uint64_t NumCounters;
275 if (Line.is_at_end())
276 return error(instrprof_error::truncated);
277 if ((Line++)->getAsInteger(10, NumCounters))
278 return error(instrprof_error::malformed);
279 if (NumCounters == 0)
280 return error(instrprof_error::malformed);
281
282 // Read each counter and fill our internal storage with the values.
283 Record.Clear();
284 Record.Counts.reserve(NumCounters);
285 for (uint64_t I = 0; I < NumCounters; ++I) {
286 if (Line.is_at_end())
287 return error(instrprof_error::truncated);
288 uint64_t Count;
289 if ((Line++)->getAsInteger(10, Count))
290 return error(instrprof_error::malformed);
291 Record.Counts.push_back(Count);
292 }
293
294 // Check if value profile data exists and read it if so.
295 if (Error E = readValueProfileData(Record))
296 return error(std::move(E));
297
298 return success();
299 }
300
301 template <class IntPtrT>
hasFormat(const MemoryBuffer & DataBuffer)302 bool RawInstrProfReader<IntPtrT>::hasFormat(const MemoryBuffer &DataBuffer) {
303 if (DataBuffer.getBufferSize() < sizeof(uint64_t))
304 return false;
305 uint64_t Magic =
306 *reinterpret_cast<const uint64_t *>(DataBuffer.getBufferStart());
307 return RawInstrProf::getMagic<IntPtrT>() == Magic ||
308 sys::getSwappedBytes(RawInstrProf::getMagic<IntPtrT>()) == Magic;
309 }
310
311 template <class IntPtrT>
readHeader()312 Error RawInstrProfReader<IntPtrT>::readHeader() {
313 if (!hasFormat(*DataBuffer))
314 return error(instrprof_error::bad_magic);
315 if (DataBuffer->getBufferSize() < sizeof(RawInstrProf::Header))
316 return error(instrprof_error::bad_header);
317 auto *Header = reinterpret_cast<const RawInstrProf::Header *>(
318 DataBuffer->getBufferStart());
319 ShouldSwapBytes = Header->Magic != RawInstrProf::getMagic<IntPtrT>();
320 return readHeader(*Header);
321 }
322
323 template <class IntPtrT>
readNextHeader(const char * CurrentPos)324 Error RawInstrProfReader<IntPtrT>::readNextHeader(const char *CurrentPos) {
325 const char *End = DataBuffer->getBufferEnd();
326 // Skip zero padding between profiles.
327 while (CurrentPos != End && *CurrentPos == 0)
328 ++CurrentPos;
329 // If there's nothing left, we're done.
330 if (CurrentPos == End)
331 return make_error<InstrProfError>(instrprof_error::eof);
332 // If there isn't enough space for another header, this is probably just
333 // garbage at the end of the file.
334 if (CurrentPos + sizeof(RawInstrProf::Header) > End)
335 return make_error<InstrProfError>(instrprof_error::malformed);
336 // The writer ensures each profile is padded to start at an aligned address.
337 if (reinterpret_cast<size_t>(CurrentPos) % alignof(uint64_t))
338 return make_error<InstrProfError>(instrprof_error::malformed);
339 // The magic should have the same byte order as in the previous header.
340 uint64_t Magic = *reinterpret_cast<const uint64_t *>(CurrentPos);
341 if (Magic != swap(RawInstrProf::getMagic<IntPtrT>()))
342 return make_error<InstrProfError>(instrprof_error::bad_magic);
343
344 // There's another profile to read, so we need to process the header.
345 auto *Header = reinterpret_cast<const RawInstrProf::Header *>(CurrentPos);
346 return readHeader(*Header);
347 }
348
349 template <class IntPtrT>
createSymtab(InstrProfSymtab & Symtab)350 Error RawInstrProfReader<IntPtrT>::createSymtab(InstrProfSymtab &Symtab) {
351 if (Error E = Symtab.create(StringRef(NamesStart, NamesSize)))
352 return error(std::move(E));
353 for (const RawInstrProf::ProfileData<IntPtrT> *I = Data; I != DataEnd; ++I) {
354 const IntPtrT FPtr = swap(I->FunctionPointer);
355 if (!FPtr)
356 continue;
357 Symtab.mapAddress(FPtr, I->NameRef);
358 }
359 return success();
360 }
361
362 template <class IntPtrT>
readHeader(const RawInstrProf::Header & Header)363 Error RawInstrProfReader<IntPtrT>::readHeader(
364 const RawInstrProf::Header &Header) {
365 Version = swap(Header.Version);
366 if (GET_VERSION(Version) != RawInstrProf::Version)
367 return error(instrprof_error::unsupported_version);
368
369 CountersDelta = swap(Header.CountersDelta);
370 NamesDelta = swap(Header.NamesDelta);
371 auto DataSize = swap(Header.DataSize);
372 auto PaddingBytesBeforeCounters = swap(Header.PaddingBytesBeforeCounters);
373 auto CountersSize = swap(Header.CountersSize);
374 auto PaddingBytesAfterCounters = swap(Header.PaddingBytesAfterCounters);
375 NamesSize = swap(Header.NamesSize);
376 ValueKindLast = swap(Header.ValueKindLast);
377
378 auto DataSizeInBytes = DataSize * sizeof(RawInstrProf::ProfileData<IntPtrT>);
379 auto PaddingSize = getNumPaddingBytes(NamesSize);
380
381 ptrdiff_t DataOffset = sizeof(RawInstrProf::Header);
382 ptrdiff_t CountersOffset =
383 DataOffset + DataSizeInBytes + PaddingBytesBeforeCounters;
384 ptrdiff_t NamesOffset = CountersOffset + (sizeof(uint64_t) * CountersSize) +
385 PaddingBytesAfterCounters;
386 ptrdiff_t ValueDataOffset = NamesOffset + NamesSize + PaddingSize;
387
388 auto *Start = reinterpret_cast<const char *>(&Header);
389 if (Start + ValueDataOffset > DataBuffer->getBufferEnd())
390 return error(instrprof_error::bad_header);
391
392 Data = reinterpret_cast<const RawInstrProf::ProfileData<IntPtrT> *>(
393 Start + DataOffset);
394 DataEnd = Data + DataSize;
395 CountersStart = reinterpret_cast<const uint64_t *>(Start + CountersOffset);
396 NamesStart = Start + NamesOffset;
397 ValueDataStart = reinterpret_cast<const uint8_t *>(Start + ValueDataOffset);
398
399 std::unique_ptr<InstrProfSymtab> NewSymtab = std::make_unique<InstrProfSymtab>();
400 if (Error E = createSymtab(*NewSymtab.get()))
401 return E;
402
403 Symtab = std::move(NewSymtab);
404 return success();
405 }
406
407 template <class IntPtrT>
readName(NamedInstrProfRecord & Record)408 Error RawInstrProfReader<IntPtrT>::readName(NamedInstrProfRecord &Record) {
409 Record.Name = getName(Data->NameRef);
410 return success();
411 }
412
413 template <class IntPtrT>
readFuncHash(NamedInstrProfRecord & Record)414 Error RawInstrProfReader<IntPtrT>::readFuncHash(NamedInstrProfRecord &Record) {
415 Record.Hash = swap(Data->FuncHash);
416 return success();
417 }
418
419 template <class IntPtrT>
readRawCounts(InstrProfRecord & Record)420 Error RawInstrProfReader<IntPtrT>::readRawCounts(
421 InstrProfRecord &Record) {
422 uint32_t NumCounters = swap(Data->NumCounters);
423 IntPtrT CounterPtr = Data->CounterPtr;
424 if (NumCounters == 0)
425 return error(instrprof_error::malformed);
426
427 auto *NamesStartAsCounter = reinterpret_cast<const uint64_t *>(NamesStart);
428 ptrdiff_t MaxNumCounters = NamesStartAsCounter - CountersStart;
429
430 // Check bounds. Note that the counter pointer embedded in the data record
431 // may itself be corrupt.
432 if (MaxNumCounters < 0 || NumCounters > (uint32_t)MaxNumCounters)
433 return error(instrprof_error::malformed);
434 ptrdiff_t CounterOffset = getCounterOffset(CounterPtr);
435 if (CounterOffset < 0 || CounterOffset > MaxNumCounters ||
436 ((uint32_t)CounterOffset + NumCounters) > (uint32_t)MaxNumCounters)
437 return error(instrprof_error::malformed);
438
439 auto RawCounts = makeArrayRef(getCounter(CounterOffset), NumCounters);
440
441 if (ShouldSwapBytes) {
442 Record.Counts.clear();
443 Record.Counts.reserve(RawCounts.size());
444 for (uint64_t Count : RawCounts)
445 Record.Counts.push_back(swap(Count));
446 } else
447 Record.Counts = RawCounts;
448
449 return success();
450 }
451
452 template <class IntPtrT>
readValueProfilingData(InstrProfRecord & Record)453 Error RawInstrProfReader<IntPtrT>::readValueProfilingData(
454 InstrProfRecord &Record) {
455 Record.clearValueData();
456 CurValueDataSize = 0;
457 // Need to match the logic in value profile dumper code in compiler-rt:
458 uint32_t NumValueKinds = 0;
459 for (uint32_t I = 0; I < IPVK_Last + 1; I++)
460 NumValueKinds += (Data->NumValueSites[I] != 0);
461
462 if (!NumValueKinds)
463 return success();
464
465 Expected<std::unique_ptr<ValueProfData>> VDataPtrOrErr =
466 ValueProfData::getValueProfData(
467 ValueDataStart, (const unsigned char *)DataBuffer->getBufferEnd(),
468 getDataEndianness());
469
470 if (Error E = VDataPtrOrErr.takeError())
471 return E;
472
473 // Note that besides deserialization, this also performs the conversion for
474 // indirect call targets. The function pointers from the raw profile are
475 // remapped into function name hashes.
476 VDataPtrOrErr.get()->deserializeTo(Record, Symtab.get());
477 CurValueDataSize = VDataPtrOrErr.get()->getSize();
478 return success();
479 }
480
481 template <class IntPtrT>
readNextRecord(NamedInstrProfRecord & Record)482 Error RawInstrProfReader<IntPtrT>::readNextRecord(NamedInstrProfRecord &Record) {
483 if (atEnd())
484 // At this point, ValueDataStart field points to the next header.
485 if (Error E = readNextHeader(getNextHeaderPos()))
486 return error(std::move(E));
487
488 // Read name ad set it in Record.
489 if (Error E = readName(Record))
490 return error(std::move(E));
491
492 // Read FuncHash and set it in Record.
493 if (Error E = readFuncHash(Record))
494 return error(std::move(E));
495
496 // Read raw counts and set Record.
497 if (Error E = readRawCounts(Record))
498 return error(std::move(E));
499
500 // Read value data and set Record.
501 if (Error E = readValueProfilingData(Record))
502 return error(std::move(E));
503
504 // Iterate.
505 advanceData();
506 return success();
507 }
508
509 namespace llvm {
510
511 template class RawInstrProfReader<uint32_t>;
512 template class RawInstrProfReader<uint64_t>;
513
514 } // end namespace llvm
515
516 InstrProfLookupTrait::hash_value_type
ComputeHash(StringRef K)517 InstrProfLookupTrait::ComputeHash(StringRef K) {
518 return IndexedInstrProf::ComputeHash(HashType, K);
519 }
520
521 using data_type = InstrProfLookupTrait::data_type;
522 using offset_type = InstrProfLookupTrait::offset_type;
523
readValueProfilingData(const unsigned char * & D,const unsigned char * const End)524 bool InstrProfLookupTrait::readValueProfilingData(
525 const unsigned char *&D, const unsigned char *const End) {
526 Expected<std::unique_ptr<ValueProfData>> VDataPtrOrErr =
527 ValueProfData::getValueProfData(D, End, ValueProfDataEndianness);
528
529 if (VDataPtrOrErr.takeError())
530 return false;
531
532 VDataPtrOrErr.get()->deserializeTo(DataBuffer.back(), nullptr);
533 D += VDataPtrOrErr.get()->TotalSize;
534
535 return true;
536 }
537
ReadData(StringRef K,const unsigned char * D,offset_type N)538 data_type InstrProfLookupTrait::ReadData(StringRef K, const unsigned char *D,
539 offset_type N) {
540 using namespace support;
541
542 // Check if the data is corrupt. If so, don't try to read it.
543 if (N % sizeof(uint64_t))
544 return data_type();
545
546 DataBuffer.clear();
547 std::vector<uint64_t> CounterBuffer;
548
549 const unsigned char *End = D + N;
550 while (D < End) {
551 // Read hash.
552 if (D + sizeof(uint64_t) >= End)
553 return data_type();
554 uint64_t Hash = endian::readNext<uint64_t, little, unaligned>(D);
555
556 // Initialize number of counters for GET_VERSION(FormatVersion) == 1.
557 uint64_t CountsSize = N / sizeof(uint64_t) - 1;
558 // If format version is different then read the number of counters.
559 if (GET_VERSION(FormatVersion) != IndexedInstrProf::ProfVersion::Version1) {
560 if (D + sizeof(uint64_t) > End)
561 return data_type();
562 CountsSize = endian::readNext<uint64_t, little, unaligned>(D);
563 }
564 // Read counter values.
565 if (D + CountsSize * sizeof(uint64_t) > End)
566 return data_type();
567
568 CounterBuffer.clear();
569 CounterBuffer.reserve(CountsSize);
570 for (uint64_t J = 0; J < CountsSize; ++J)
571 CounterBuffer.push_back(endian::readNext<uint64_t, little, unaligned>(D));
572
573 DataBuffer.emplace_back(K, Hash, std::move(CounterBuffer));
574
575 // Read value profiling data.
576 if (GET_VERSION(FormatVersion) > IndexedInstrProf::ProfVersion::Version2 &&
577 !readValueProfilingData(D, End)) {
578 DataBuffer.clear();
579 return data_type();
580 }
581 }
582 return DataBuffer;
583 }
584
585 template <typename HashTableImpl>
getRecords(StringRef FuncName,ArrayRef<NamedInstrProfRecord> & Data)586 Error InstrProfReaderIndex<HashTableImpl>::getRecords(
587 StringRef FuncName, ArrayRef<NamedInstrProfRecord> &Data) {
588 auto Iter = HashTable->find(FuncName);
589 if (Iter == HashTable->end())
590 return make_error<InstrProfError>(instrprof_error::unknown_function);
591
592 Data = (*Iter);
593 if (Data.empty())
594 return make_error<InstrProfError>(instrprof_error::malformed);
595
596 return Error::success();
597 }
598
599 template <typename HashTableImpl>
getRecords(ArrayRef<NamedInstrProfRecord> & Data)600 Error InstrProfReaderIndex<HashTableImpl>::getRecords(
601 ArrayRef<NamedInstrProfRecord> &Data) {
602 if (atEnd())
603 return make_error<InstrProfError>(instrprof_error::eof);
604
605 Data = *RecordIterator;
606
607 if (Data.empty())
608 return make_error<InstrProfError>(instrprof_error::malformed);
609
610 return Error::success();
611 }
612
613 template <typename HashTableImpl>
InstrProfReaderIndex(const unsigned char * Buckets,const unsigned char * const Payload,const unsigned char * const Base,IndexedInstrProf::HashT HashType,uint64_t Version)614 InstrProfReaderIndex<HashTableImpl>::InstrProfReaderIndex(
615 const unsigned char *Buckets, const unsigned char *const Payload,
616 const unsigned char *const Base, IndexedInstrProf::HashT HashType,
617 uint64_t Version) {
618 FormatVersion = Version;
619 HashTable.reset(HashTableImpl::Create(
620 Buckets, Payload, Base,
621 typename HashTableImpl::InfoType(HashType, Version)));
622 RecordIterator = HashTable->data_begin();
623 }
624
625 namespace {
626 /// A remapper that does not apply any remappings.
627 class InstrProfReaderNullRemapper : public InstrProfReaderRemapper {
628 InstrProfReaderIndexBase &Underlying;
629
630 public:
InstrProfReaderNullRemapper(InstrProfReaderIndexBase & Underlying)631 InstrProfReaderNullRemapper(InstrProfReaderIndexBase &Underlying)
632 : Underlying(Underlying) {}
633
getRecords(StringRef FuncName,ArrayRef<NamedInstrProfRecord> & Data)634 Error getRecords(StringRef FuncName,
635 ArrayRef<NamedInstrProfRecord> &Data) override {
636 return Underlying.getRecords(FuncName, Data);
637 }
638 };
639 }
640
641 /// A remapper that applies remappings based on a symbol remapping file.
642 template <typename HashTableImpl>
643 class llvm::InstrProfReaderItaniumRemapper
644 : public InstrProfReaderRemapper {
645 public:
InstrProfReaderItaniumRemapper(std::unique_ptr<MemoryBuffer> RemapBuffer,InstrProfReaderIndex<HashTableImpl> & Underlying)646 InstrProfReaderItaniumRemapper(
647 std::unique_ptr<MemoryBuffer> RemapBuffer,
648 InstrProfReaderIndex<HashTableImpl> &Underlying)
649 : RemapBuffer(std::move(RemapBuffer)), Underlying(Underlying) {
650 }
651
652 /// Extract the original function name from a PGO function name.
extractName(StringRef Name)653 static StringRef extractName(StringRef Name) {
654 // We can have multiple :-separated pieces; there can be pieces both
655 // before and after the mangled name. Find the first part that starts
656 // with '_Z'; we'll assume that's the mangled name we want.
657 std::pair<StringRef, StringRef> Parts = {StringRef(), Name};
658 while (true) {
659 Parts = Parts.second.split(':');
660 if (Parts.first.startswith("_Z"))
661 return Parts.first;
662 if (Parts.second.empty())
663 return Name;
664 }
665 }
666
667 /// Given a mangled name extracted from a PGO function name, and a new
668 /// form for that mangled name, reconstitute the name.
reconstituteName(StringRef OrigName,StringRef ExtractedName,StringRef Replacement,SmallVectorImpl<char> & Out)669 static void reconstituteName(StringRef OrigName, StringRef ExtractedName,
670 StringRef Replacement,
671 SmallVectorImpl<char> &Out) {
672 Out.reserve(OrigName.size() + Replacement.size() - ExtractedName.size());
673 Out.insert(Out.end(), OrigName.begin(), ExtractedName.begin());
674 Out.insert(Out.end(), Replacement.begin(), Replacement.end());
675 Out.insert(Out.end(), ExtractedName.end(), OrigName.end());
676 }
677
populateRemappings()678 Error populateRemappings() override {
679 if (Error E = Remappings.read(*RemapBuffer))
680 return E;
681 for (StringRef Name : Underlying.HashTable->keys()) {
682 StringRef RealName = extractName(Name);
683 if (auto Key = Remappings.insert(RealName)) {
684 // FIXME: We could theoretically map the same equivalence class to
685 // multiple names in the profile data. If that happens, we should
686 // return NamedInstrProfRecords from all of them.
687 MappedNames.insert({Key, RealName});
688 }
689 }
690 return Error::success();
691 }
692
getRecords(StringRef FuncName,ArrayRef<NamedInstrProfRecord> & Data)693 Error getRecords(StringRef FuncName,
694 ArrayRef<NamedInstrProfRecord> &Data) override {
695 StringRef RealName = extractName(FuncName);
696 if (auto Key = Remappings.lookup(RealName)) {
697 StringRef Remapped = MappedNames.lookup(Key);
698 if (!Remapped.empty()) {
699 if (RealName.begin() == FuncName.begin() &&
700 RealName.end() == FuncName.end())
701 FuncName = Remapped;
702 else {
703 // Try rebuilding the name from the given remapping.
704 SmallString<256> Reconstituted;
705 reconstituteName(FuncName, RealName, Remapped, Reconstituted);
706 Error E = Underlying.getRecords(Reconstituted, Data);
707 if (!E)
708 return E;
709
710 // If we failed because the name doesn't exist, fall back to asking
711 // about the original name.
712 if (Error Unhandled = handleErrors(
713 std::move(E), [](std::unique_ptr<InstrProfError> Err) {
714 return Err->get() == instrprof_error::unknown_function
715 ? Error::success()
716 : Error(std::move(Err));
717 }))
718 return Unhandled;
719 }
720 }
721 }
722 return Underlying.getRecords(FuncName, Data);
723 }
724
725 private:
726 /// The memory buffer containing the remapping configuration. Remappings
727 /// holds pointers into this buffer.
728 std::unique_ptr<MemoryBuffer> RemapBuffer;
729
730 /// The mangling remapper.
731 SymbolRemappingReader Remappings;
732
733 /// Mapping from mangled name keys to the name used for the key in the
734 /// profile data.
735 /// FIXME: Can we store a location within the on-disk hash table instead of
736 /// redoing lookup?
737 DenseMap<SymbolRemappingReader::Key, StringRef> MappedNames;
738
739 /// The real profile data reader.
740 InstrProfReaderIndex<HashTableImpl> &Underlying;
741 };
742
hasFormat(const MemoryBuffer & DataBuffer)743 bool IndexedInstrProfReader::hasFormat(const MemoryBuffer &DataBuffer) {
744 using namespace support;
745
746 if (DataBuffer.getBufferSize() < 8)
747 return false;
748 uint64_t Magic =
749 endian::read<uint64_t, little, aligned>(DataBuffer.getBufferStart());
750 // Verify that it's magical.
751 return Magic == IndexedInstrProf::Magic;
752 }
753
754 const unsigned char *
readSummary(IndexedInstrProf::ProfVersion Version,const unsigned char * Cur,bool UseCS)755 IndexedInstrProfReader::readSummary(IndexedInstrProf::ProfVersion Version,
756 const unsigned char *Cur, bool UseCS) {
757 using namespace IndexedInstrProf;
758 using namespace support;
759
760 if (Version >= IndexedInstrProf::Version4) {
761 const IndexedInstrProf::Summary *SummaryInLE =
762 reinterpret_cast<const IndexedInstrProf::Summary *>(Cur);
763 uint64_t NFields =
764 endian::byte_swap<uint64_t, little>(SummaryInLE->NumSummaryFields);
765 uint64_t NEntries =
766 endian::byte_swap<uint64_t, little>(SummaryInLE->NumCutoffEntries);
767 uint32_t SummarySize =
768 IndexedInstrProf::Summary::getSize(NFields, NEntries);
769 std::unique_ptr<IndexedInstrProf::Summary> SummaryData =
770 IndexedInstrProf::allocSummary(SummarySize);
771
772 const uint64_t *Src = reinterpret_cast<const uint64_t *>(SummaryInLE);
773 uint64_t *Dst = reinterpret_cast<uint64_t *>(SummaryData.get());
774 for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++)
775 Dst[I] = endian::byte_swap<uint64_t, little>(Src[I]);
776
777 SummaryEntryVector DetailedSummary;
778 for (unsigned I = 0; I < SummaryData->NumCutoffEntries; I++) {
779 const IndexedInstrProf::Summary::Entry &Ent = SummaryData->getEntry(I);
780 DetailedSummary.emplace_back((uint32_t)Ent.Cutoff, Ent.MinBlockCount,
781 Ent.NumBlocks);
782 }
783 std::unique_ptr<llvm::ProfileSummary> &Summary =
784 UseCS ? this->CS_Summary : this->Summary;
785
786 // initialize InstrProfSummary using the SummaryData from disk.
787 Summary = std::make_unique<ProfileSummary>(
788 UseCS ? ProfileSummary::PSK_CSInstr : ProfileSummary::PSK_Instr,
789 DetailedSummary, SummaryData->get(Summary::TotalBlockCount),
790 SummaryData->get(Summary::MaxBlockCount),
791 SummaryData->get(Summary::MaxInternalBlockCount),
792 SummaryData->get(Summary::MaxFunctionCount),
793 SummaryData->get(Summary::TotalNumBlocks),
794 SummaryData->get(Summary::TotalNumFunctions));
795 return Cur + SummarySize;
796 } else {
797 // The older versions do not support a profile summary. This just computes
798 // an empty summary, which will not result in accurate hot/cold detection.
799 // We would need to call addRecord for all NamedInstrProfRecords to get the
800 // correct summary. However, this version is old (prior to early 2016) and
801 // has not been supporting an accurate summary for several years.
802 InstrProfSummaryBuilder Builder(ProfileSummaryBuilder::DefaultCutoffs);
803 Summary = Builder.getSummary();
804 return Cur;
805 }
806 }
807
readHeader()808 Error IndexedInstrProfReader::readHeader() {
809 using namespace support;
810
811 const unsigned char *Start =
812 (const unsigned char *)DataBuffer->getBufferStart();
813 const unsigned char *Cur = Start;
814 if ((const unsigned char *)DataBuffer->getBufferEnd() - Cur < 24)
815 return error(instrprof_error::truncated);
816
817 auto *Header = reinterpret_cast<const IndexedInstrProf::Header *>(Cur);
818 Cur += sizeof(IndexedInstrProf::Header);
819
820 // Check the magic number.
821 uint64_t Magic = endian::byte_swap<uint64_t, little>(Header->Magic);
822 if (Magic != IndexedInstrProf::Magic)
823 return error(instrprof_error::bad_magic);
824
825 // Read the version.
826 uint64_t FormatVersion = endian::byte_swap<uint64_t, little>(Header->Version);
827 if (GET_VERSION(FormatVersion) >
828 IndexedInstrProf::ProfVersion::CurrentVersion)
829 return error(instrprof_error::unsupported_version);
830
831 Cur = readSummary((IndexedInstrProf::ProfVersion)FormatVersion, Cur,
832 /* UseCS */ false);
833 if (FormatVersion & VARIANT_MASK_CSIR_PROF)
834 Cur = readSummary((IndexedInstrProf::ProfVersion)FormatVersion, Cur,
835 /* UseCS */ true);
836
837 // Read the hash type and start offset.
838 IndexedInstrProf::HashT HashType = static_cast<IndexedInstrProf::HashT>(
839 endian::byte_swap<uint64_t, little>(Header->HashType));
840 if (HashType > IndexedInstrProf::HashT::Last)
841 return error(instrprof_error::unsupported_hash_type);
842
843 uint64_t HashOffset = endian::byte_swap<uint64_t, little>(Header->HashOffset);
844
845 // The rest of the file is an on disk hash table.
846 auto IndexPtr =
847 std::make_unique<InstrProfReaderIndex<OnDiskHashTableImplV3>>(
848 Start + HashOffset, Cur, Start, HashType, FormatVersion);
849
850 // Load the remapping table now if requested.
851 if (RemappingBuffer) {
852 Remapper = std::make_unique<
853 InstrProfReaderItaniumRemapper<OnDiskHashTableImplV3>>(
854 std::move(RemappingBuffer), *IndexPtr);
855 if (Error E = Remapper->populateRemappings())
856 return E;
857 } else {
858 Remapper = std::make_unique<InstrProfReaderNullRemapper>(*IndexPtr);
859 }
860 Index = std::move(IndexPtr);
861
862 return success();
863 }
864
getSymtab()865 InstrProfSymtab &IndexedInstrProfReader::getSymtab() {
866 if (Symtab.get())
867 return *Symtab.get();
868
869 std::unique_ptr<InstrProfSymtab> NewSymtab = std::make_unique<InstrProfSymtab>();
870 if (Error E = Index->populateSymtab(*NewSymtab.get())) {
871 consumeError(error(InstrProfError::take(std::move(E))));
872 }
873
874 Symtab = std::move(NewSymtab);
875 return *Symtab.get();
876 }
877
878 Expected<InstrProfRecord>
getInstrProfRecord(StringRef FuncName,uint64_t FuncHash)879 IndexedInstrProfReader::getInstrProfRecord(StringRef FuncName,
880 uint64_t FuncHash) {
881 ArrayRef<NamedInstrProfRecord> Data;
882 Error Err = Remapper->getRecords(FuncName, Data);
883 if (Err)
884 return std::move(Err);
885 // Found it. Look for counters with the right hash.
886 for (unsigned I = 0, E = Data.size(); I < E; ++I) {
887 // Check for a match and fill the vector if there is one.
888 if (Data[I].Hash == FuncHash) {
889 return std::move(Data[I]);
890 }
891 }
892 return error(instrprof_error::hash_mismatch);
893 }
894
getFunctionCounts(StringRef FuncName,uint64_t FuncHash,std::vector<uint64_t> & Counts)895 Error IndexedInstrProfReader::getFunctionCounts(StringRef FuncName,
896 uint64_t FuncHash,
897 std::vector<uint64_t> &Counts) {
898 Expected<InstrProfRecord> Record = getInstrProfRecord(FuncName, FuncHash);
899 if (Error E = Record.takeError())
900 return error(std::move(E));
901
902 Counts = Record.get().Counts;
903 return success();
904 }
905
readNextRecord(NamedInstrProfRecord & Record)906 Error IndexedInstrProfReader::readNextRecord(NamedInstrProfRecord &Record) {
907 ArrayRef<NamedInstrProfRecord> Data;
908
909 Error E = Index->getRecords(Data);
910 if (E)
911 return error(std::move(E));
912
913 Record = Data[RecordIndex++];
914 if (RecordIndex >= Data.size()) {
915 Index->advanceToNextKey();
916 RecordIndex = 0;
917 }
918 return success();
919 }
920
accumulateCounts(CountSumOrPercent & Sum,bool IsCS)921 void InstrProfReader::accumulateCounts(CountSumOrPercent &Sum, bool IsCS) {
922 uint64_t NumFuncs = 0;
923 for (const auto &Func : *this) {
924 if (isIRLevelProfile()) {
925 bool FuncIsCS = NamedInstrProfRecord::hasCSFlagInHash(Func.Hash);
926 if (FuncIsCS != IsCS)
927 continue;
928 }
929 Func.accumulateCounts(Sum);
930 ++NumFuncs;
931 }
932 Sum.NumEntries = NumFuncs;
933 }
934