clang 8.0.0

GlobalModuleIndex.cpp
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1 //===--- GlobalModuleIndex.cpp - Global Module Index ------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the GlobalModuleIndex class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "ASTReaderInternals.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Lex/HeaderSearch.h"
17 #include "clang/Serialization/ASTBitCodes.h"
18 #include "clang/Serialization/GlobalModuleIndex.h"
19 #include "clang/Serialization/Module.h"
20 #include "clang/Serialization/PCHContainerOperations.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/MapVector.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/Bitcode/BitstreamReader.h"
25 #include "llvm/Bitcode/BitstreamWriter.h"
26 #include "llvm/Support/DJB.h"
27 #include "llvm/Support/FileSystem.h"
28 #include "llvm/Support/LockFileManager.h"
29 #include "llvm/Support/MemoryBuffer.h"
30 #include "llvm/Support/OnDiskHashTable.h"
31 #include "llvm/Support/Path.h"
32 #include <cstdio>
33 using namespace clang;
34 using namespace serialization;
35
36 //----------------------------------------------------------------------------//
37 // Shared constants
38 //----------------------------------------------------------------------------//
39 namespace {
40 enum {
41 /// The block containing the index.
42 GLOBAL_INDEX_BLOCK_ID = llvm::bitc::FIRST_APPLICATION_BLOCKID
43 };
44
45 /// Describes the record types in the index.
46 enum IndexRecordTypes {
47 /// Contains version information and potentially other metadata,
48 /// used to determine if we can read this global index file.
49 INDEX_METADATA,
50 /// Describes a module, including its file name and dependencies.
51 MODULE,
52 /// The index for identifiers.
53 IDENTIFIER_INDEX
54 };
55 }
56
57 /// The name of the global index file.
58 static const char * const IndexFileName = "modules.idx";
59
60 /// The global index file version.
61 static const unsigned CurrentVersion = 1;
62
63 //----------------------------------------------------------------------------//
64 // Global module index reader.
65 //----------------------------------------------------------------------------//
66
67 namespace {
68
69 /// Trait used to read the identifier index from the on-disk hash
70 /// table.
71 class IdentifierIndexReaderTrait {
72 public:
73 typedef StringRef external_key_type;
74 typedef StringRef internal_key_type;
75 typedef SmallVector<unsigned, 2> data_type;
76 typedef unsigned hash_value_type;
77 typedef unsigned offset_type;
78
79 static bool EqualKey(const internal_key_type& a, const internal_key_type& b) {
80 return a == b;
81 }
82
83 static hash_value_type ComputeHash(const internal_key_type& a) {
84 return llvm::djbHash(a);
85 }
86
87 static std::pair<unsigned, unsigned>
88 ReadKeyDataLength(const unsigned char*& d) {
89 using namespace llvm::support;
90 unsigned KeyLen = endian::readNext<uint16_t, little, unaligned>(d);
91 unsigned DataLen = endian::readNext<uint16_t, little, unaligned>(d);
92 return std::make_pair(KeyLen, DataLen);
93 }
94
95 static const internal_key_type&
96 GetInternalKey(const external_key_type& x) { return x; }
97
98 static const external_key_type&
99 GetExternalKey(const internal_key_type& x) { return x; }
100
101 static internal_key_type ReadKey(const unsigned char* d, unsigned n) {
102 return StringRef((const char *)d, n);
103 }
104
105 static data_type ReadData(const internal_key_type& k,
106 const unsigned char* d,
107 unsigned DataLen) {
108 using namespace llvm::support;
109
110 data_type Result;
111 while (DataLen > 0) {
112 unsigned ID = endian::readNext<uint32_t, little, unaligned>(d);
113 Result.push_back(ID);
114 DataLen -= 4;
115 }
116
117 return Result;
118 }
119 };
120
121 typedef llvm::OnDiskIterableChainedHashTable<IdentifierIndexReaderTrait>
122 IdentifierIndexTable;
123
124 }
125
126 GlobalModuleIndex::GlobalModuleIndex(std::unique_ptr<llvm::MemoryBuffer> Buffer,
127 llvm::BitstreamCursor Cursor)
128 : Buffer(std::move(Buffer)), IdentifierIndex(), NumIdentifierLookups(),
129 NumIdentifierLookupHits() {
130 // Read the global index.
131 bool InGlobalIndexBlock = false;
132 bool Done = false;
133 while (!Done) {
134 llvm::BitstreamEntry Entry = Cursor.advance();
135
136 switch (Entry.Kind) {
137 case llvm::BitstreamEntry::Error:
138 return;
139
140 case llvm::BitstreamEntry::EndBlock:
141 if (InGlobalIndexBlock) {
142 InGlobalIndexBlock = false;
143 Done = true;
144 continue;
145 }
146 return;
147
148
149 case llvm::BitstreamEntry::Record:
150 // Entries in the global index block are handled below.
151 if (InGlobalIndexBlock)
152 break;
153
154 return;
155
156 case llvm::BitstreamEntry::SubBlock:
157 if (!InGlobalIndexBlock && Entry.ID == GLOBAL_INDEX_BLOCK_ID) {
158 if (Cursor.EnterSubBlock(GLOBAL_INDEX_BLOCK_ID))
159 return;
160
161 InGlobalIndexBlock = true;
162 } else if (Cursor.SkipBlock()) {
163 return;
164 }
165 continue;
166 }
167
168 SmallVector<uint64_t, 64> Record;
169 StringRef Blob;
170 switch ((IndexRecordTypes)Cursor.readRecord(Entry.ID, Record, &Blob)) {
171 case INDEX_METADATA:
172 // Make sure that the version matches.
173 if (Record.size() < 1 || Record[0] != CurrentVersion)
174 return;
175 break;
176
177 case MODULE: {
178 unsigned Idx = 0;
179 unsigned ID = Record[Idx++];
180
181 // Make room for this module's information.
182 if (ID == Modules.size())
183 Modules.push_back(ModuleInfo());
184 else
185 Modules.resize(ID + 1);
186
187 // Size/modification time for this module file at the time the
188 // global index was built.
189 Modules[ID].Size = Record[Idx++];
190 Modules[ID].ModTime = Record[Idx++];
191
192 // File name.
193 unsigned NameLen = Record[Idx++];
194 Modules[ID].FileName.assign(Record.begin() + Idx,
195 Record.begin() + Idx + NameLen);
196 Idx += NameLen;
197
198 // Dependencies
199 unsigned NumDeps = Record[Idx++];
200 Modules[ID].Dependencies.insert(Modules[ID].Dependencies.end(),
201 Record.begin() + Idx,
202 Record.begin() + Idx + NumDeps);
203 Idx += NumDeps;
204
205 // Make sure we're at the end of the record.
206 assert(Idx == Record.size() && "More module info?");
207
208 // Record this module as an unresolved module.
209 // FIXME: this doesn't work correctly for module names containing path
210 // separators.
211 StringRef ModuleName = llvm::sys::path::stem(Modules[ID].FileName);
212 // Remove the -<hash of ModuleMapPath>
213 ModuleName = ModuleName.rsplit('-').first;
214 UnresolvedModules[ModuleName] = ID;
215 break;
216 }
217
218 case IDENTIFIER_INDEX:
219 // Wire up the identifier index.
220 if (Record[0]) {
221 IdentifierIndex = IdentifierIndexTable::Create(
222 (const unsigned char *)Blob.data() + Record[0],
223 (const unsigned char *)Blob.data() + sizeof(uint32_t),
224 (const unsigned char *)Blob.data(), IdentifierIndexReaderTrait());
225 }
226 break;
227 }
228 }
229 }
230
231 GlobalModuleIndex::~GlobalModuleIndex() {
232 delete static_cast<IdentifierIndexTable *>(IdentifierIndex);
233 }
234
235 std::pair<GlobalModuleIndex *, GlobalModuleIndex::ErrorCode>
236 GlobalModuleIndex::readIndex(StringRef Path) {
237 // Load the index file, if it's there.
238 llvm::SmallString<128> IndexPath;
239 IndexPath += Path;
240 llvm::sys::path::append(IndexPath, IndexFileName);
241
242 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> BufferOrErr =
243 llvm::MemoryBuffer::getFile(IndexPath.c_str());
244 if (!BufferOrErr)
245 return std::make_pair(nullptr, EC_NotFound);
246 std::unique_ptr<llvm::MemoryBuffer> Buffer = std::move(BufferOrErr.get());
247
248 /// The main bitstream cursor for the main block.
249 llvm::BitstreamCursor Cursor(*Buffer);
250
251 // Sniff for the signature.
252 if (Cursor.Read(8) != 'B' ||
253 Cursor.Read(8) != 'C' ||
254 Cursor.Read(8) != 'G' ||
255 Cursor.Read(8) != 'I') {
256 return std::make_pair(nullptr, EC_IOError);
257 }
258
259 return std::make_pair(new GlobalModuleIndex(std::move(Buffer), Cursor),
260 EC_None);
261 }
262
263 void
264 GlobalModuleIndex::getKnownModules(SmallVectorImpl<ModuleFile *> &ModuleFiles) {
265 ModuleFiles.clear();
266 for (unsigned I = 0, N = Modules.size(); I != N; ++I) {
267 if (ModuleFile *MF = Modules[I].File)
268 ModuleFiles.push_back(MF);
269 }
270 }
271
272 void GlobalModuleIndex::getModuleDependencies(
273 ModuleFile *File,
274 SmallVectorImpl<ModuleFile *> &Dependencies) {
275 // Look for information about this module file.
276 llvm::DenseMap<ModuleFile *, unsigned>::iterator Known
277 = ModulesByFile.find(File);
278 if (Known == ModulesByFile.end())
279 return;
280
281 // Record dependencies.
282 Dependencies.clear();
283 ArrayRef<unsigned> StoredDependencies = Modules[Known->second].Dependencies;
284 for (unsigned I = 0, N = StoredDependencies.size(); I != N; ++I) {
285 if (ModuleFile *MF = Modules[I].File)
286 Dependencies.push_back(MF);
287 }
288 }
289
290 bool GlobalModuleIndex::lookupIdentifier(StringRef Name, HitSet &Hits) {
291 Hits.clear();
292
293 // If there's no identifier index, there is nothing we can do.
294 if (!IdentifierIndex)
295 return false;
296
297 // Look into the identifier index.
298 ++NumIdentifierLookups;
299 IdentifierIndexTable &Table
300 = *static_cast<IdentifierIndexTable *>(IdentifierIndex);
301 IdentifierIndexTable::iterator Known = Table.find(Name);
302 if (Known == Table.end()) {
303 return true;
304 }
305
306 SmallVector<unsigned, 2> ModuleIDs = *Known;
307 for (unsigned I = 0, N = ModuleIDs.size(); I != N; ++I) {
308 if (ModuleFile *MF = Modules[ModuleIDs[I]].File)
309 Hits.insert(MF);
310 }
311
312 ++NumIdentifierLookupHits;
313 return true;
314 }
315
316 bool GlobalModuleIndex::loadedModuleFile(ModuleFile *File) {
317 // Look for the module in the global module index based on the module name.
318 StringRef Name = File->ModuleName;
319 llvm::StringMap<unsigned>::iterator Known = UnresolvedModules.find(Name);
320 if (Known == UnresolvedModules.end()) {
321 return true;
322 }
323
324 // Rectify this module with the global module index.
325 ModuleInfo &Info = Modules[Known->second];
326
327 // If the size and modification time match what we expected, record this
328 // module file.
329 bool Failed = true;
330 if (File->File->getSize() == Info.Size &&
331 File->File->getModificationTime() == Info.ModTime) {
332 Info.File = File;
333 ModulesByFile[File] = Known->second;
334
335 Failed = false;
336 }
337
338 // One way or another, we have resolved this module file.
339 UnresolvedModules.erase(Known);
340 return Failed;
341 }
342
343 void GlobalModuleIndex::printStats() {
344 std::fprintf(stderr, "*** Global Module Index Statistics:\n");
345 if (NumIdentifierLookups) {
346 fprintf(stderr, " %u / %u identifier lookups succeeded (%f%%)\n",
347 NumIdentifierLookupHits, NumIdentifierLookups,
348 (double)NumIdentifierLookupHits*100.0/NumIdentifierLookups);
349 }
350 std::fprintf(stderr, "\n");
351 }
352
353 LLVM_DUMP_METHOD void GlobalModuleIndex::dump() {
354 llvm::errs() << "*** Global Module Index Dump:\n";
355 llvm::errs() << "Module files:\n";
356 for (auto &MI : Modules) {
357 llvm::errs() << "** " << MI.FileName << "\n";
358 if (MI.File)
359 MI.File->dump();
360 else
361 llvm::errs() << "\n";
362 }
363 llvm::errs() << "\n";
364 }
365
366 //----------------------------------------------------------------------------//
367 // Global module index writer.
368 //----------------------------------------------------------------------------//
369
370 namespace {
371 /// Provides information about a specific module file.
372 struct ModuleFileInfo {
373 /// The numberic ID for this module file.
374 unsigned ID;
375
376 /// The set of modules on which this module depends. Each entry is
377 /// a module ID.
378 SmallVector<unsigned, 4> Dependencies;
379 ASTFileSignature Signature;
380 };
381
382 struct ImportedModuleFileInfo {
383 off_t StoredSize;
384 time_t StoredModTime;
385 ASTFileSignature StoredSignature;
386 ImportedModuleFileInfo(off_t Size, time_t ModTime, ASTFileSignature Sig)
387 : StoredSize(Size), StoredModTime(ModTime), StoredSignature(Sig) {}
388 };
389
390 /// Builder that generates the global module index file.
391 class GlobalModuleIndexBuilder {
392 FileManager &FileMgr;
393 const PCHContainerReader &PCHContainerRdr;
394
395 /// Mapping from files to module file information.
396 typedef llvm::MapVector<const FileEntry *, ModuleFileInfo> ModuleFilesMap;
397
398 /// Information about each of the known module files.
399 ModuleFilesMap ModuleFiles;
400
401 /// Mapping from the imported module file to the imported
402 /// information.
403 typedef std::multimap<const FileEntry *, ImportedModuleFileInfo>
404 ImportedModuleFilesMap;
405
406 /// Information about each importing of a module file.
407 ImportedModuleFilesMap ImportedModuleFiles;
408
409 /// Mapping from identifiers to the list of module file IDs that
410 /// consider this identifier to be interesting.
411 typedef llvm::StringMap<SmallVector<unsigned, 2> > InterestingIdentifierMap;
412
413 /// A mapping from all interesting identifiers to the set of module
414 /// files in which those identifiers are considered interesting.
415 InterestingIdentifierMap InterestingIdentifiers;
416
417 /// Write the block-info block for the global module index file.
418 void emitBlockInfoBlock(llvm::BitstreamWriter &Stream);
419
420 /// Retrieve the module file information for the given file.
421 ModuleFileInfo &getModuleFileInfo(const FileEntry *File) {
422 llvm::MapVector<const FileEntry *, ModuleFileInfo>::iterator Known
423 = ModuleFiles.find(File);
424 if (Known != ModuleFiles.end())
425 return Known->second;
426
427 unsigned NewID = ModuleFiles.size();
428 ModuleFileInfo &Info = ModuleFiles[File];
429 Info.ID = NewID;
430 return Info;
431 }
432
433 public:
434 explicit GlobalModuleIndexBuilder(
435 FileManager &FileMgr, const PCHContainerReader &PCHContainerRdr)
436 : FileMgr(FileMgr), PCHContainerRdr(PCHContainerRdr) {}
437
438 /// Load the contents of the given module file into the builder.
439 ///
440 /// \returns true if an error occurred, false otherwise.
441 bool loadModuleFile(const FileEntry *File);
442
443 /// Write the index to the given bitstream.
444 /// \returns true if an error occurred, false otherwise.
445 bool writeIndex(llvm::BitstreamWriter &Stream);
446 };
447 }
448
449 static void emitBlockID(unsigned ID, const char *Name,
450 llvm::BitstreamWriter &Stream,
451 SmallVectorImpl<uint64_t> &Record) {
452 Record.clear();
453 Record.push_back(ID);
454 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
455
456 // Emit the block name if present.
457 if (!Name || Name[0] == 0) return;
458 Record.clear();
459 while (*Name)
460 Record.push_back(*Name++);
461 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
462 }
463
464 static void emitRecordID(unsigned ID, const char *Name,
465 llvm::BitstreamWriter &Stream,
466 SmallVectorImpl<uint64_t> &Record) {
467 Record.clear();
468 Record.push_back(ID);
469 while (*Name)
470 Record.push_back(*Name++);
471 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
472 }
473
474 void
475 GlobalModuleIndexBuilder::emitBlockInfoBlock(llvm::BitstreamWriter &Stream) {
476 SmallVector<uint64_t, 64> Record;
477 Stream.EnterBlockInfoBlock();
478
479 #define BLOCK(X) emitBlockID(X ## _ID, #X, Stream, Record)
480 #define RECORD(X) emitRecordID(X, #X, Stream, Record)
481 BLOCK(GLOBAL_INDEX_BLOCK);
482 RECORD(INDEX_METADATA);
483 RECORD(MODULE);
484 RECORD(IDENTIFIER_INDEX);
485 #undef RECORD
486 #undef BLOCK
487
488 Stream.ExitBlock();
489 }
490
491 namespace {
492 class InterestingASTIdentifierLookupTrait
493 : public serialization::reader::ASTIdentifierLookupTraitBase {
494
495 public:
496 /// The identifier and whether it is "interesting".
497 typedef std::pair<StringRef, bool> data_type;
498
499 data_type ReadData(const internal_key_type& k,
500 const unsigned char* d,
501 unsigned DataLen) {
502 // The first bit indicates whether this identifier is interesting.
503 // That's all we care about.
504 using namespace llvm::support;
505 unsigned RawID = endian::readNext<uint32_t, little, unaligned>(d);
506 bool IsInteresting = RawID & 0x01;
507 return std::make_pair(k, IsInteresting);
508 }
509 };
510 }
511
512 bool GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
513 // Open the module file.
514
515 auto Buffer = FileMgr.getBufferForFile(File, /*isVolatile=*/true);
516 if (!Buffer) {
517 return true;
518 }
519
520 // Initialize the input stream
521 llvm::BitstreamCursor InStream(PCHContainerRdr.ExtractPCH(**Buffer));
522
523 // Sniff for the signature.
524 if (InStream.Read(8) != 'C' ||
525 InStream.Read(8) != 'P' ||
526 InStream.Read(8) != 'C' ||
527 InStream.Read(8) != 'H') {
528 return true;
529 }
530
531 // Record this module file and assign it a unique ID (if it doesn't have
532 // one already).
533 unsigned ID = getModuleFileInfo(File).ID;
534
535 // Search for the blocks and records we care about.
536 enum { Other, ControlBlock, ASTBlock, DiagnosticOptionsBlock } State = Other;
537 bool Done = false;
538 while (!Done) {
539 llvm::BitstreamEntry Entry = InStream.advance();
540 switch (Entry.Kind) {
541 case llvm::BitstreamEntry::Error:
542 Done = true;
543 continue;
544
545 case llvm::BitstreamEntry::Record:
546 // In the 'other' state, just skip the record. We don't care.
547 if (State == Other) {
548 InStream.skipRecord(Entry.ID);
549 continue;
550 }
551
552 // Handle potentially-interesting records below.
553 break;
554
555 case llvm::BitstreamEntry::SubBlock:
556 if (Entry.ID == CONTROL_BLOCK_ID) {
557 if (InStream.EnterSubBlock(CONTROL_BLOCK_ID))
558 return true;
559
560 // Found the control block.
561 State = ControlBlock;
562 continue;
563 }
564
565 if (Entry.ID == AST_BLOCK_ID) {
566 if (InStream.EnterSubBlock(AST_BLOCK_ID))
567 return true;
568
569 // Found the AST block.
570 State = ASTBlock;
571 continue;
572 }
573
574 if (Entry.ID == UNHASHED_CONTROL_BLOCK_ID) {
575 if (InStream.EnterSubBlock(UNHASHED_CONTROL_BLOCK_ID))
576 return true;
577
578 // Found the Diagnostic Options block.
579 State = DiagnosticOptionsBlock;
580 continue;
581 }
582
583 if (InStream.SkipBlock())
584 return true;
585
586 continue;
587
588 case llvm::BitstreamEntry::EndBlock:
589 State = Other;
590 continue;
591 }
592
593 // Read the given record.
594 SmallVector<uint64_t, 64> Record;
595 StringRef Blob;
596 unsigned Code = InStream.readRecord(Entry.ID, Record, &Blob);
597
598 // Handle module dependencies.
599 if (State == ControlBlock && Code == IMPORTS) {
600 // Load each of the imported PCH files.
601 unsigned Idx = 0, N = Record.size();
602 while (Idx < N) {
603 // Read information about the AST file.
604
605 // Skip the imported kind
606 ++Idx;
607
608 // Skip the import location
609 ++Idx;
610
611 // Load stored size/modification time.
612 off_t StoredSize = (off_t)Record[Idx++];
613 time_t StoredModTime = (time_t)Record[Idx++];
614
615 // Skip the stored signature.
616 // FIXME: we could read the signature out of the import and validate it.
617 ASTFileSignature StoredSignature = {
618 {{(uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
619 (uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
620 (uint32_t)Record[Idx++]}}};
621
622 // Skip the module name (currently this is only used for prebuilt
623 // modules while here we are only dealing with cached).
624 Idx += Record[Idx] + 1;
625
626 // Retrieve the imported file name.
627 unsigned Length = Record[Idx++];
628 SmallString<128> ImportedFile(Record.begin() + Idx,
629 Record.begin() + Idx + Length);
630 Idx += Length;
631
632 // Find the imported module file.
633 const FileEntry *DependsOnFile
634 = FileMgr.getFile(ImportedFile, /*openFile=*/false,
635 /*cacheFailure=*/false);
636
637 if (!DependsOnFile)
638 return true;
639
640 // Save the information in ImportedModuleFileInfo so we can verify after
641 // loading all pcms.
642 ImportedModuleFiles.insert(std::make_pair(
643 DependsOnFile, ImportedModuleFileInfo(StoredSize, StoredModTime,
644 StoredSignature)));
645
646 // Record the dependency.
647 unsigned DependsOnID = getModuleFileInfo(DependsOnFile).ID;
648 getModuleFileInfo(File).Dependencies.push_back(DependsOnID);
649 }
650
651 continue;
652 }
653
654 // Handle the identifier table
655 if (State == ASTBlock && Code == IDENTIFIER_TABLE && Record[0] > 0) {
656 typedef llvm::OnDiskIterableChainedHashTable<
657 InterestingASTIdentifierLookupTrait> InterestingIdentifierTable;
658 std::unique_ptr<InterestingIdentifierTable> Table(
659 InterestingIdentifierTable::Create(
660 (const unsigned char *)Blob.data() + Record[0],
661 (const unsigned char *)Blob.data() + sizeof(uint32_t),
662 (const unsigned char *)Blob.data()));
663 for (InterestingIdentifierTable::data_iterator D = Table->data_begin(),
664 DEnd = Table->data_end();
665 D != DEnd; ++D) {
666 std::pair<StringRef, bool> Ident = *D;
667 if (Ident.second)
668 InterestingIdentifiers[Ident.first].push_back(ID);
669 else
670 (void)InterestingIdentifiers[Ident.first];
671 }
672 }
673
674 // Get Signature.
675 if (State == DiagnosticOptionsBlock && Code == SIGNATURE)
676 getModuleFileInfo(File).Signature = {
677 {{(uint32_t)Record[0], (uint32_t)Record[1], (uint32_t)Record[2],
678 (uint32_t)Record[3], (uint32_t)Record[4]}}};
679
680 // We don't care about this record.
681 }
682
683 return false;
684 }
685
686 namespace {
687
688 /// Trait used to generate the identifier index as an on-disk hash
689 /// table.
690 class IdentifierIndexWriterTrait {
691 public:
692 typedef StringRef key_type;
693 typedef StringRef key_type_ref;
694 typedef SmallVector<unsigned, 2> data_type;
695 typedef const SmallVector<unsigned, 2> &data_type_ref;
696 typedef unsigned hash_value_type;
697 typedef unsigned offset_type;
698
699 static hash_value_type ComputeHash(key_type_ref Key) {
700 return llvm::djbHash(Key);
701 }
702
703 std::pair<unsigned,unsigned>
704 EmitKeyDataLength(raw_ostream& Out, key_type_ref Key, data_type_ref Data) {
705 using namespace llvm::support;
706 endian::Writer LE(Out, little);
707 unsigned KeyLen = Key.size();
708 unsigned DataLen = Data.size() * 4;
709 LE.write<uint16_t>(KeyLen);
710 LE.write<uint16_t>(DataLen);
711 return std::make_pair(KeyLen, DataLen);
712 }
713
714 void EmitKey(raw_ostream& Out, key_type_ref Key, unsigned KeyLen) {
715 Out.write(Key.data(), KeyLen);
716 }
717
718 void EmitData(raw_ostream& Out, key_type_ref Key, data_type_ref Data,
719 unsigned DataLen) {
720 using namespace llvm::support;
721 for (unsigned I = 0, N = Data.size(); I != N; ++I)
722 endian::write<uint32_t>(Out, Data[I], little);
723 }
724 };
725
726 }
727
728 bool GlobalModuleIndexBuilder::writeIndex(llvm::BitstreamWriter &Stream) {
729 for (auto MapEntry : ImportedModuleFiles) {
730 auto *File = MapEntry.first;
731 ImportedModuleFileInfo &Info = MapEntry.second;
732 if (getModuleFileInfo(File).Signature) {
733 if (getModuleFileInfo(File).Signature != Info.StoredSignature)
734 // Verify Signature.
735 return true;
736 } else if (Info.StoredSize != File->getSize() ||
737 Info.StoredModTime != File->getModificationTime())
738 // Verify Size and ModTime.
739 return true;
740 }
741
742 using namespace llvm;
743
744 // Emit the file header.
745 Stream.Emit((unsigned)'B', 8);
746 Stream.Emit((unsigned)'C', 8);
747 Stream.Emit((unsigned)'G', 8);
748 Stream.Emit((unsigned)'I', 8);
749
750 // Write the block-info block, which describes the records in this bitcode
751 // file.
752 emitBlockInfoBlock(Stream);
753
754 Stream.EnterSubblock(GLOBAL_INDEX_BLOCK_ID, 3);
755
756 // Write the metadata.
757 SmallVector<uint64_t, 2> Record;
758 Record.push_back(CurrentVersion);
759 Stream.EmitRecord(INDEX_METADATA, Record);
760
761 // Write the set of known module files.
762 for (ModuleFilesMap::iterator M = ModuleFiles.begin(),
763 MEnd = ModuleFiles.end();
764 M != MEnd; ++M) {
765 Record.clear();
766 Record.push_back(M->second.ID);
767 Record.push_back(M->first->getSize());
768 Record.push_back(M->first->getModificationTime());
769
770 // File name
771 StringRef Name(M->first->getName());
772 Record.push_back(Name.size());
773 Record.append(Name.begin(), Name.end());
774
775 // Dependencies
776 Record.push_back(M->second.Dependencies.size());
777 Record.append(M->second.Dependencies.begin(), M->second.Dependencies.end());
778 Stream.EmitRecord(MODULE, Record);
779 }
780
781 // Write the identifier -> module file mapping.
782 {
783 llvm::OnDiskChainedHashTableGenerator<IdentifierIndexWriterTrait> Generator;
784 IdentifierIndexWriterTrait Trait;
785
786 // Populate the hash table.
787 for (InterestingIdentifierMap::iterator I = InterestingIdentifiers.begin(),
788 IEnd = InterestingIdentifiers.end();
789 I != IEnd; ++I) {
790 Generator.insert(I->first(), I->second, Trait);
791 }
792
793 // Create the on-disk hash table in a buffer.
794 SmallString<4096> IdentifierTable;
795 uint32_t BucketOffset;
796 {
797 using namespace llvm::support;
798 llvm::raw_svector_ostream Out(IdentifierTable);
799 // Make sure that no bucket is at offset 0
800 endian::write<uint32_t>(Out, 0, little);
801 BucketOffset = Generator.Emit(Out, Trait);
802 }
803
804 // Create a blob abbreviation
805 auto Abbrev = std::make_shared<BitCodeAbbrev>();
806 Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_INDEX));
807 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
808 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
809 unsigned IDTableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
810
811 // Write the identifier table
812 uint64_t Record[] = {IDENTIFIER_INDEX, BucketOffset};
813 Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
814 }
815
816 Stream.ExitBlock();
817 return false;
818 }
819
820 GlobalModuleIndex::ErrorCode
821 GlobalModuleIndex::writeIndex(FileManager &FileMgr,
822 const PCHContainerReader &PCHContainerRdr,
823 StringRef Path) {
824 llvm::SmallString<128> IndexPath;
825 IndexPath += Path;
826 llvm::sys::path::append(IndexPath, IndexFileName);
827
828 // Coordinate building the global index file with other processes that might
829 // try to do the same.
830 llvm::LockFileManager Locked(IndexPath);
831 switch (Locked) {
832 case llvm::LockFileManager::LFS_Error:
833 return EC_IOError;
834
835 case llvm::LockFileManager::LFS_Owned:
836 // We're responsible for building the index ourselves. Do so below.
837 break;
838
839 case llvm::LockFileManager::LFS_Shared:
840 // Someone else is responsible for building the index. We don't care
841 // when they finish, so we're done.
842 return EC_Building;
843 }
844
845 // The module index builder.
846 GlobalModuleIndexBuilder Builder(FileMgr, PCHContainerRdr);
847
848 // Load each of the module files.
849 std::error_code EC;
850 for (llvm::sys::fs::directory_iterator D(Path, EC), DEnd;
851 D != DEnd && !EC;
852 D.increment(EC)) {
853 // If this isn't a module file, we don't care.
854 if (llvm::sys::path::extension(D->path()) != ".pcm") {
855 // ... unless it's a .pcm.lock file, which indicates that someone is
856 // in the process of rebuilding a module. They'll rebuild the index
857 // at the end of that translation unit, so we don't have to.
858 if (llvm::sys::path::extension(D->path()) == ".pcm.lock")
859 return EC_Building;
860
861 continue;
862 }
863
864 // If we can't find the module file, skip it.
865 const FileEntry *ModuleFile = FileMgr.getFile(D->path());
866 if (!ModuleFile)
867 continue;
868
869 // Load this module file.
870 if (Builder.loadModuleFile(ModuleFile))
871 return EC_IOError;
872 }
873
874 // The output buffer, into which the global index will be written.
875 SmallVector<char, 16> OutputBuffer;
876 {
877 llvm::BitstreamWriter OutputStream(OutputBuffer);
878 if (Builder.writeIndex(OutputStream))
879 return EC_IOError;
880 }
881
882 // Write the global index file to a temporary file.
883 llvm::SmallString<128> IndexTmpPath;
884 int TmpFD;
885 if (llvm::sys::fs::createUniqueFile(IndexPath + "-%%%%%%%%", TmpFD,
886 IndexTmpPath))
887 return EC_IOError;
888
889 // Open the temporary global index file for output.
890 llvm::raw_fd_ostream Out(TmpFD, true);
891 if (Out.has_error())
892 return EC_IOError;
893
894 // Write the index.
895 Out.write(OutputBuffer.data(), OutputBuffer.size());
896 Out.close();
897 if (Out.has_error())
898 return EC_IOError;
899
900 // Remove the old index file. It isn't relevant any more.
901 llvm::sys::fs::remove(IndexPath);
902
903 // Rename the newly-written index file to the proper name.
904 if (llvm::sys::fs::rename(IndexTmpPath, IndexPath)) {
905 // Rename failed; just remove the
906 llvm::sys::fs::remove(IndexTmpPath);
907 return EC_IOError;
908 }
909
910 // We're done.
911 return EC_None;
912 }
913
914 namespace {
915 class GlobalIndexIdentifierIterator : public IdentifierIterator {
916 /// The current position within the identifier lookup table.
917 IdentifierIndexTable::key_iterator Current;
918
919 /// The end position within the identifier lookup table.
920 IdentifierIndexTable::key_iterator End;
921
922 public:
923 explicit GlobalIndexIdentifierIterator(IdentifierIndexTable &Idx) {
924 Current = Idx.key_begin();
925 End = Idx.key_end();
926 }
927
928 StringRef Next() override {
929 if (Current == End)
930 return StringRef();
931
932 StringRef Result = *Current;
933 ++Current;
934 return Result;
935 }
936 };
937 }
938
939 IdentifierIterator *GlobalModuleIndex::createIdentifierIterator() const {
940 IdentifierIndexTable &Table =
941 *static_cast<IdentifierIndexTable *>(IdentifierIndex);
942 return new GlobalIndexIdentifierIterator(Table);
943 }
clang::Builtin::ID
ID
Definition: Builtins.h:49
ASTReaderInternals.h
clang::FileManager
Implements support for file system lookup, file system caching, and directory search management...
Definition: FileManager.h:121
FileManager.h
Defines the clang::FileManager interface and associated types.
clang::FileEntry::getModificationTime
time_t getModificationTime() const
Definition: FileManager.h:92
llvm
DominatorTree GraphTraits specialization so the DominatorTree can be iterable by generic graph iterat...
Definition: Dominators.h:30
Cursor
Cursor
Definition: SerializedDiagnosticReader.cpp:81
clang::serialization::ModuleFile::ModuleName
std::string ModuleName
The name of the module.
Definition: Module.h:126
HeaderSearch.h
CurrentVersion
static const unsigned CurrentVersion
The global index file version.
Definition: GlobalModuleIndex.cpp:61
clang::serialization::UNHASHED_CONTROL_BLOCK_ID
A block with unhashed content.
Definition: ASTBitCodes.h:297
clang::GlobalModuleIndex::printStats
void printStats()
Print statistics to standard error.
Definition: GlobalModuleIndex.cpp:343
emitRecordID
static void emitRecordID(unsigned ID, const char *Name, llvm::BitstreamWriter &Stream, SmallVectorImpl< uint64_t > &Record)
Definition: GlobalModuleIndex.cpp:464
State
LineState State
Definition: UnwrappedLineFormatter.cpp:877
clang::GlobalModuleIndex::HitSet
llvm::SmallPtrSet< ModuleFile *, 4 > HitSet
A set of module files in which we found a result.
Definition: GlobalModuleIndex.h:166
clang::GlobalModuleIndex::readIndex
static std::pair< GlobalModuleIndex *, ErrorCode > readIndex(llvm::StringRef Path)
Read a global index file for the given directory.
Definition: GlobalModuleIndex.cpp:236
clang::ASTFileSignature
The signature of a module, which is a hash of the AST content.
Definition: Module.h:55
llvm::SmallVectorImpl
Definition: LLVM.h:37
clang::serialized_diags::Error
Definition: SerializedDiagnostics.h:48
clang::GlobalModuleIndex::ErrorCode
ErrorCode
An error code returned when trying to read an index.
Definition: GlobalModuleIndex.h:127
clang::PCHContainerReader
This abstract interface provides operations for unwrapping containers for serialized ASTs (precompile...
Definition: PCHContainerOperations.h:58
llvm::ArrayRef
Definition: LLVM.h:32
llvm::SmallString< 128 >
clang::FileManager::getFile
const FileEntry * getFile(StringRef Filename, bool OpenFile=false, bool CacheFailure=true)
Lookup, cache, and verify the specified file (real or virtual).
Definition: FileManager.cpp:183
clang::GlobalModuleIndex::lookupIdentifier
bool lookupIdentifier(llvm::StringRef Name, HitSet &Hits)
Look for all of the module files with information about the given identifier, e.g., a global function, variable, or type with that name.
Definition: GlobalModuleIndex.cpp:290
clang::GlobalModuleIndex::dump
void dump()
Print debugging view to standard error.
Definition: GlobalModuleIndex.cpp:353
End
SourceLocation End
Definition: USRLocFinder.cpp:167
emitBlockID
static void emitBlockID(unsigned ID, const char *Name, llvm::BitstreamWriter &Stream, SmallVectorImpl< uint64_t > &Record)
Definition: GlobalModuleIndex.cpp:449
clang::GlobalModuleIndex::createIdentifierIterator
IdentifierIterator * createIdentifierIterator() const
Returns an iterator for identifiers stored in the index table.
Definition: GlobalModuleIndex.cpp:939
clang::IdentifierTable
Implements an efficient mapping from strings to IdentifierInfo nodes.
Definition: IdentifierTable.h:486
clang::serialization::reader::ASTIdentifierLookupTraitBase
Base class for the trait describing the on-disk hash table for the identifiers in an AST file...
Definition: ASTReaderInternals.h:132
clang::serialization::ModuleFile
Information about a module that has been loaded by the ASTReader.
Definition: Module.h:108
clang::IdentifierIterator
An iterator that walks over all of the known identifiers in the lookup table.
Definition: IdentifierTable.h:438
ASTBitCodes.h
IndexFileName
static const char *const IndexFileName
The name of the global index file.
Definition: GlobalModuleIndex.cpp:58
clang::serialization::IDENTIFIER_TABLE
Record code for the identifier table.
Definition: ASTBitCodes.h:442
IndexRecordTypes
IndexRecordTypes
Describes the record types in the index.
Definition: GlobalModuleIndex.cpp:46
clang::FileEntry
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:60
GlobalModuleIndex.h
clang::GlobalModuleIndex::getKnownModules
void getKnownModules(llvm::SmallVectorImpl< ModuleFile *> &ModuleFiles)
Retrieve the set of modules that have up-to-date indexes.
Definition: GlobalModuleIndex.cpp:264
llvm::SmallVector
Definition: LLVM.h:36
clang::GlobalModuleIndex::~GlobalModuleIndex
~GlobalModuleIndex()
Definition: GlobalModuleIndex.cpp:231
clang::serialization::AST_BLOCK_ID
The AST block, which acts as a container around the full AST block.
Definition: ASTBitCodes.h:249
clang::GlobalModuleIndex
A global index for a set of module files, providing information about the identifiers within those mo...
Definition: GlobalModuleIndex.h:56
clang::serialization::ComputeHash
unsigned ComputeHash(Selector Sel)
Definition: ASTCommon.cpp:247
clang::serialization::SIGNATURE
Record code for the signature that identifiers this AST file.
Definition: ASTBitCodes.h:364
clang::serialization::IMPORTS
Record code for the list of other AST files imported by this AST file.
Definition: ASTBitCodes.h:308
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:22
clang::FileEntry::getSize
off_t getSize() const
Definition: FileManager.h:88
BLOCK
#define BLOCK(X)
clang::GlobalModuleIndex::getModuleDependencies
void getModuleDependencies(ModuleFile *File, llvm::SmallVectorImpl< ModuleFile *> &Dependencies)
Retrieve the set of module files on which the given module file directly depends. ...
Definition: GlobalModuleIndex.cpp:272
PCHContainerOperations.h
Module.h
clang::frontend::ModuleFileInfo
Dump information about a module file.
Definition: FrontendOptions.h:95
RECORD
#define RECORD(X)
clang::GlobalModuleIndex::writeIndex
static ErrorCode writeIndex(FileManager &FileMgr, const PCHContainerReader &PCHContainerRdr, llvm::StringRef Path)
Write a global index into the given.
Definition: GlobalModuleIndex.cpp:821
clang::serialization::CONTROL_BLOCK_ID
The control block, which contains all of the information that needs to be validated prior to committi...
Definition: ASTBitCodes.h:275
clang::serialization::ModuleFile::File
const FileEntry * File
The file entry for the module file.
Definition: Module.h:164
clang::Create
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
clang::GlobalModuleIndex::loadedModuleFile
bool loadedModuleFile(ModuleFile *File)
Note that the given module file has been loaded.
Definition: GlobalModuleIndex.cpp:316