1 //===--- GlobalModuleIndex.cpp - Global Module Index ------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements the GlobalModuleIndex class.
11 //===----------------------------------------------------------------------===//
13 #include "clang/Serialization/GlobalModuleIndex.h"
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/ModuleFile.h"
19 #include "clang/Serialization/PCHContainerOperations.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/ADT/MapVector.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/Bitstream/BitstreamReader.h"
25 #include "llvm/Bitstream/BitstreamWriter.h"
26 #include "llvm/Support/DJB.h"
27 #include "llvm/Support/FileSystem.h"
28 #include "llvm/Support/FileUtilities.h"
29 #include "llvm/Support/LockFileManager.h"
30 #include "llvm/Support/MemoryBuffer.h"
31 #include "llvm/Support/OnDiskHashTable.h"
32 #include "llvm/Support/Path.h"
33 #include "llvm/Support/TimeProfiler.h"
35 using namespace clang;
36 using namespace serialization;
38 //----------------------------------------------------------------------------//
40 //----------------------------------------------------------------------------//
43 /// The block containing the index.
44 GLOBAL_INDEX_BLOCK_ID = llvm::bitc::FIRST_APPLICATION_BLOCKID
47 /// Describes the record types in the index.
48 enum IndexRecordTypes {
49 /// Contains version information and potentially other metadata,
50 /// used to determine if we can read this global index file.
52 /// Describes a module, including its file name and dependencies.
54 /// The index for identifiers.
59 /// The name of the global index file.
60 static const char * const IndexFileName = "modules.idx";
62 /// The global index file version.
63 static const unsigned CurrentVersion = 1;
65 //----------------------------------------------------------------------------//
66 // Global module index reader.
67 //----------------------------------------------------------------------------//
71 /// Trait used to read the identifier index from the on-disk hash
73 class IdentifierIndexReaderTrait {
75 typedef StringRef external_key_type;
76 typedef StringRef internal_key_type;
77 typedef SmallVector<unsigned, 2> data_type;
78 typedef unsigned hash_value_type;
79 typedef unsigned offset_type;
81 static bool EqualKey(const internal_key_type& a, const internal_key_type& b) {
85 static hash_value_type ComputeHash(const internal_key_type& a) {
86 return llvm::djbHash(a);
89 static std::pair<unsigned, unsigned>
90 ReadKeyDataLength(const unsigned char*& d) {
91 using namespace llvm::support;
92 unsigned KeyLen = endian::readNext<uint16_t, little, unaligned>(d);
93 unsigned DataLen = endian::readNext<uint16_t, little, unaligned>(d);
94 return std::make_pair(KeyLen, DataLen);
97 static const internal_key_type&
98 GetInternalKey(const external_key_type& x) { return x; }
100 static const external_key_type&
101 GetExternalKey(const internal_key_type& x) { return x; }
103 static internal_key_type ReadKey(const unsigned char* d, unsigned n) {
104 return StringRef((const char *)d, n);
107 static data_type ReadData(const internal_key_type& k,
108 const unsigned char* d,
110 using namespace llvm::support;
113 while (DataLen > 0) {
114 unsigned ID = endian::readNext<uint32_t, little, unaligned>(d);
115 Result.push_back(ID);
123 typedef llvm::OnDiskIterableChainedHashTable<IdentifierIndexReaderTrait>
124 IdentifierIndexTable;
128 GlobalModuleIndex::GlobalModuleIndex(
129 std::unique_ptr<llvm::MemoryBuffer> IndexBuffer,
130 llvm::BitstreamCursor Cursor)
131 : Buffer(std::move(IndexBuffer)), IdentifierIndex(), NumIdentifierLookups(),
132 NumIdentifierLookupHits() {
133 auto Fail = [&](llvm::Error &&Err) {
134 report_fatal_error("Module index '" + Buffer->getBufferIdentifier() +
135 "' failed: " + toString(std::move(Err)));
138 llvm::TimeTraceScope TimeScope("Module LoadIndex");
139 // Read the global index.
140 bool InGlobalIndexBlock = false;
143 llvm::BitstreamEntry Entry;
144 if (Expected<llvm::BitstreamEntry> Res = Cursor.advance())
147 Fail(Res.takeError());
149 switch (Entry.Kind) {
150 case llvm::BitstreamEntry::Error:
153 case llvm::BitstreamEntry::EndBlock:
154 if (InGlobalIndexBlock) {
155 InGlobalIndexBlock = false;
162 case llvm::BitstreamEntry::Record:
163 // Entries in the global index block are handled below.
164 if (InGlobalIndexBlock)
169 case llvm::BitstreamEntry::SubBlock:
170 if (!InGlobalIndexBlock && Entry.ID == GLOBAL_INDEX_BLOCK_ID) {
171 if (llvm::Error Err = Cursor.EnterSubBlock(GLOBAL_INDEX_BLOCK_ID))
172 Fail(std::move(Err));
173 InGlobalIndexBlock = true;
174 } else if (llvm::Error Err = Cursor.SkipBlock())
175 Fail(std::move(Err));
179 SmallVector<uint64_t, 64> Record;
181 Expected<unsigned> MaybeIndexRecord =
182 Cursor.readRecord(Entry.ID, Record, &Blob);
183 if (!MaybeIndexRecord)
184 Fail(MaybeIndexRecord.takeError());
185 IndexRecordTypes IndexRecord =
186 static_cast<IndexRecordTypes>(MaybeIndexRecord.get());
187 switch (IndexRecord) {
189 // Make sure that the version matches.
190 if (Record.size() < 1 || Record[0] != CurrentVersion)
196 unsigned ID = Record[Idx++];
198 // Make room for this module's information.
199 if (ID == Modules.size())
200 Modules.push_back(ModuleInfo());
202 Modules.resize(ID + 1);
204 // Size/modification time for this module file at the time the
205 // global index was built.
206 Modules[ID].Size = Record[Idx++];
207 Modules[ID].ModTime = Record[Idx++];
210 unsigned NameLen = Record[Idx++];
211 Modules[ID].FileName.assign(Record.begin() + Idx,
212 Record.begin() + Idx + NameLen);
216 unsigned NumDeps = Record[Idx++];
217 Modules[ID].Dependencies.insert(Modules[ID].Dependencies.end(),
218 Record.begin() + Idx,
219 Record.begin() + Idx + NumDeps);
222 // Make sure we're at the end of the record.
223 assert(Idx == Record.size() && "More module info?");
225 // Record this module as an unresolved module.
226 // FIXME: this doesn't work correctly for module names containing path
228 StringRef ModuleName = llvm::sys::path::stem(Modules[ID].FileName);
229 // Remove the -<hash of ModuleMapPath>
230 ModuleName = ModuleName.rsplit('-').first;
231 UnresolvedModules[ModuleName] = ID;
235 case IDENTIFIER_INDEX:
236 // Wire up the identifier index.
238 IdentifierIndex = IdentifierIndexTable::Create(
239 (const unsigned char *)Blob.data() + Record[0],
240 (const unsigned char *)Blob.data() + sizeof(uint32_t),
241 (const unsigned char *)Blob.data(), IdentifierIndexReaderTrait());
248 GlobalModuleIndex::~GlobalModuleIndex() {
249 delete static_cast<IdentifierIndexTable *>(IdentifierIndex);
252 std::pair<GlobalModuleIndex *, llvm::Error>
253 GlobalModuleIndex::readIndex(StringRef Path) {
254 // Load the index file, if it's there.
255 llvm::SmallString<128> IndexPath;
257 llvm::sys::path::append(IndexPath, IndexFileName);
259 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> BufferOrErr =
260 llvm::MemoryBuffer::getFile(IndexPath.c_str());
262 return std::make_pair(nullptr,
263 llvm::errorCodeToError(BufferOrErr.getError()));
264 std::unique_ptr<llvm::MemoryBuffer> Buffer = std::move(BufferOrErr.get());
266 /// The main bitstream cursor for the main block.
267 llvm::BitstreamCursor Cursor(*Buffer);
269 // Sniff for the signature.
270 for (unsigned char C : {'B', 'C', 'G', 'I'}) {
271 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Cursor.Read(8)) {
273 return std::make_pair(
274 nullptr, llvm::createStringError(std::errc::illegal_byte_sequence,
275 "expected signature BCGI"));
277 return std::make_pair(nullptr, Res.takeError());
280 return std::make_pair(new GlobalModuleIndex(std::move(Buffer), Cursor),
281 llvm::Error::success());
285 GlobalModuleIndex::getKnownModules(SmallVectorImpl<ModuleFile *> &ModuleFiles) {
287 for (unsigned I = 0, N = Modules.size(); I != N; ++I) {
288 if (ModuleFile *MF = Modules[I].File)
289 ModuleFiles.push_back(MF);
293 void GlobalModuleIndex::getModuleDependencies(
295 SmallVectorImpl<ModuleFile *> &Dependencies) {
296 // Look for information about this module file.
297 llvm::DenseMap<ModuleFile *, unsigned>::iterator Known
298 = ModulesByFile.find(File);
299 if (Known == ModulesByFile.end())
302 // Record dependencies.
303 Dependencies.clear();
304 ArrayRef<unsigned> StoredDependencies = Modules[Known->second].Dependencies;
305 for (unsigned I = 0, N = StoredDependencies.size(); I != N; ++I) {
306 if (ModuleFile *MF = Modules[I].File)
307 Dependencies.push_back(MF);
311 bool GlobalModuleIndex::lookupIdentifier(StringRef Name, HitSet &Hits) {
314 // If there's no identifier index, there is nothing we can do.
315 if (!IdentifierIndex)
318 // Look into the identifier index.
319 ++NumIdentifierLookups;
320 IdentifierIndexTable &Table
321 = *static_cast<IdentifierIndexTable *>(IdentifierIndex);
322 IdentifierIndexTable::iterator Known = Table.find(Name);
323 if (Known == Table.end()) {
327 SmallVector<unsigned, 2> ModuleIDs = *Known;
328 for (unsigned I = 0, N = ModuleIDs.size(); I != N; ++I) {
329 if (ModuleFile *MF = Modules[ModuleIDs[I]].File)
333 ++NumIdentifierLookupHits;
337 bool GlobalModuleIndex::loadedModuleFile(ModuleFile *File) {
338 // Look for the module in the global module index based on the module name.
339 StringRef Name = File->ModuleName;
340 llvm::StringMap<unsigned>::iterator Known = UnresolvedModules.find(Name);
341 if (Known == UnresolvedModules.end()) {
345 // Rectify this module with the global module index.
346 ModuleInfo &Info = Modules[Known->second];
348 // If the size and modification time match what we expected, record this
351 if (File->File->getSize() == Info.Size &&
352 File->File->getModificationTime() == Info.ModTime) {
354 ModulesByFile[File] = Known->second;
359 // One way or another, we have resolved this module file.
360 UnresolvedModules.erase(Known);
364 void GlobalModuleIndex::printStats() {
365 std::fprintf(stderr, "*** Global Module Index Statistics:\n");
366 if (NumIdentifierLookups) {
367 fprintf(stderr, " %u / %u identifier lookups succeeded (%f%%)\n",
368 NumIdentifierLookupHits, NumIdentifierLookups,
369 (double)NumIdentifierLookupHits*100.0/NumIdentifierLookups);
371 std::fprintf(stderr, "\n");
374 LLVM_DUMP_METHOD void GlobalModuleIndex::dump() {
375 llvm::errs() << "*** Global Module Index Dump:\n";
376 llvm::errs() << "Module files:\n";
377 for (auto &MI : Modules) {
378 llvm::errs() << "** " << MI.FileName << "\n";
382 llvm::errs() << "\n";
384 llvm::errs() << "\n";
387 //----------------------------------------------------------------------------//
388 // Global module index writer.
389 //----------------------------------------------------------------------------//
392 /// Provides information about a specific module file.
393 struct ModuleFileInfo {
394 /// The numberic ID for this module file.
397 /// The set of modules on which this module depends. Each entry is
399 SmallVector<unsigned, 4> Dependencies;
400 ASTFileSignature Signature;
403 struct ImportedModuleFileInfo {
405 time_t StoredModTime;
406 ASTFileSignature StoredSignature;
407 ImportedModuleFileInfo(off_t Size, time_t ModTime, ASTFileSignature Sig)
408 : StoredSize(Size), StoredModTime(ModTime), StoredSignature(Sig) {}
411 /// Builder that generates the global module index file.
412 class GlobalModuleIndexBuilder {
413 FileManager &FileMgr;
414 const PCHContainerReader &PCHContainerRdr;
416 /// Mapping from files to module file information.
417 typedef llvm::MapVector<const FileEntry *, ModuleFileInfo> ModuleFilesMap;
419 /// Information about each of the known module files.
420 ModuleFilesMap ModuleFiles;
422 /// Mapping from the imported module file to the imported
424 typedef std::multimap<const FileEntry *, ImportedModuleFileInfo>
425 ImportedModuleFilesMap;
427 /// Information about each importing of a module file.
428 ImportedModuleFilesMap ImportedModuleFiles;
430 /// Mapping from identifiers to the list of module file IDs that
431 /// consider this identifier to be interesting.
432 typedef llvm::StringMap<SmallVector<unsigned, 2> > InterestingIdentifierMap;
434 /// A mapping from all interesting identifiers to the set of module
435 /// files in which those identifiers are considered interesting.
436 InterestingIdentifierMap InterestingIdentifiers;
438 /// Write the block-info block for the global module index file.
439 void emitBlockInfoBlock(llvm::BitstreamWriter &Stream);
441 /// Retrieve the module file information for the given file.
442 ModuleFileInfo &getModuleFileInfo(const FileEntry *File) {
443 llvm::MapVector<const FileEntry *, ModuleFileInfo>::iterator Known
444 = ModuleFiles.find(File);
445 if (Known != ModuleFiles.end())
446 return Known->second;
448 unsigned NewID = ModuleFiles.size();
449 ModuleFileInfo &Info = ModuleFiles[File];
455 explicit GlobalModuleIndexBuilder(
456 FileManager &FileMgr, const PCHContainerReader &PCHContainerRdr)
457 : FileMgr(FileMgr), PCHContainerRdr(PCHContainerRdr) {}
459 /// Load the contents of the given module file into the builder.
460 llvm::Error loadModuleFile(const FileEntry *File);
462 /// Write the index to the given bitstream.
463 /// \returns true if an error occurred, false otherwise.
464 bool writeIndex(llvm::BitstreamWriter &Stream);
468 static void emitBlockID(unsigned ID, const char *Name,
469 llvm::BitstreamWriter &Stream,
470 SmallVectorImpl<uint64_t> &Record) {
472 Record.push_back(ID);
473 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
475 // Emit the block name if present.
476 if (!Name || Name[0] == 0) return;
479 Record.push_back(*Name++);
480 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
483 static void emitRecordID(unsigned ID, const char *Name,
484 llvm::BitstreamWriter &Stream,
485 SmallVectorImpl<uint64_t> &Record) {
487 Record.push_back(ID);
489 Record.push_back(*Name++);
490 Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
494 GlobalModuleIndexBuilder::emitBlockInfoBlock(llvm::BitstreamWriter &Stream) {
495 SmallVector<uint64_t, 64> Record;
496 Stream.EnterBlockInfoBlock();
498 #define BLOCK(X) emitBlockID(X ## _ID, #X, Stream, Record)
499 #define RECORD(X) emitRecordID(X, #X, Stream, Record)
500 BLOCK(GLOBAL_INDEX_BLOCK);
501 RECORD(INDEX_METADATA);
503 RECORD(IDENTIFIER_INDEX);
511 class InterestingASTIdentifierLookupTrait
512 : public serialization::reader::ASTIdentifierLookupTraitBase {
515 /// The identifier and whether it is "interesting".
516 typedef std::pair<StringRef, bool> data_type;
518 data_type ReadData(const internal_key_type& k,
519 const unsigned char* d,
521 // The first bit indicates whether this identifier is interesting.
522 // That's all we care about.
523 using namespace llvm::support;
524 unsigned RawID = endian::readNext<uint32_t, little, unaligned>(d);
525 bool IsInteresting = RawID & 0x01;
526 return std::make_pair(k, IsInteresting);
531 llvm::Error GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
532 // Open the module file.
534 auto Buffer = FileMgr.getBufferForFile(File, /*isVolatile=*/true);
536 return llvm::createStringError(Buffer.getError(),
537 "failed getting buffer for module file");
539 // Initialize the input stream
540 llvm::BitstreamCursor InStream(PCHContainerRdr.ExtractPCH(**Buffer));
542 // Sniff for the signature.
543 for (unsigned char C : {'C', 'P', 'C', 'H'})
544 if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = InStream.Read(8)) {
546 return llvm::createStringError(std::errc::illegal_byte_sequence,
547 "expected signature CPCH");
549 return Res.takeError();
551 // Record this module file and assign it a unique ID (if it doesn't have
553 unsigned ID = getModuleFileInfo(File).ID;
555 // Search for the blocks and records we care about.
556 enum { Other, ControlBlock, ASTBlock, DiagnosticOptionsBlock } State = Other;
559 Expected<llvm::BitstreamEntry> MaybeEntry = InStream.advance();
561 return MaybeEntry.takeError();
562 llvm::BitstreamEntry Entry = MaybeEntry.get();
564 switch (Entry.Kind) {
565 case llvm::BitstreamEntry::Error:
569 case llvm::BitstreamEntry::Record:
570 // In the 'other' state, just skip the record. We don't care.
571 if (State == Other) {
572 if (llvm::Expected<unsigned> Skipped = InStream.skipRecord(Entry.ID))
575 return Skipped.takeError();
578 // Handle potentially-interesting records below.
581 case llvm::BitstreamEntry::SubBlock:
582 if (Entry.ID == CONTROL_BLOCK_ID) {
583 if (llvm::Error Err = InStream.EnterSubBlock(CONTROL_BLOCK_ID))
586 // Found the control block.
587 State = ControlBlock;
591 if (Entry.ID == AST_BLOCK_ID) {
592 if (llvm::Error Err = InStream.EnterSubBlock(AST_BLOCK_ID))
595 // Found the AST block.
600 if (Entry.ID == UNHASHED_CONTROL_BLOCK_ID) {
601 if (llvm::Error Err = InStream.EnterSubBlock(UNHASHED_CONTROL_BLOCK_ID))
604 // Found the Diagnostic Options block.
605 State = DiagnosticOptionsBlock;
609 if (llvm::Error Err = InStream.SkipBlock())
614 case llvm::BitstreamEntry::EndBlock:
619 // Read the given record.
620 SmallVector<uint64_t, 64> Record;
622 Expected<unsigned> MaybeCode = InStream.readRecord(Entry.ID, Record, &Blob);
624 return MaybeCode.takeError();
625 unsigned Code = MaybeCode.get();
627 // Handle module dependencies.
628 if (State == ControlBlock && Code == IMPORTS) {
629 // Load each of the imported PCH files.
630 unsigned Idx = 0, N = Record.size();
632 // Read information about the AST file.
634 // Skip the imported kind
637 // Skip the import location
640 // Load stored size/modification time.
641 off_t StoredSize = (off_t)Record[Idx++];
642 time_t StoredModTime = (time_t)Record[Idx++];
644 // Skip the stored signature.
645 // FIXME: we could read the signature out of the import and validate it.
646 ASTFileSignature StoredSignature = {
647 {{(uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
648 (uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
649 (uint32_t)Record[Idx++]}}};
651 // Skip the module name (currently this is only used for prebuilt
652 // modules while here we are only dealing with cached).
653 Idx += Record[Idx] + 1;
655 // Retrieve the imported file name.
656 unsigned Length = Record[Idx++];
657 SmallString<128> ImportedFile(Record.begin() + Idx,
658 Record.begin() + Idx + Length);
661 // Find the imported module file.
663 = FileMgr.getFile(ImportedFile, /*OpenFile=*/false,
664 /*CacheFailure=*/false);
667 return llvm::createStringError(std::errc::bad_file_descriptor,
668 "imported file \"%s\" not found",
669 ImportedFile.c_str());
671 // Save the information in ImportedModuleFileInfo so we can verify after
673 ImportedModuleFiles.insert(std::make_pair(
674 *DependsOnFile, ImportedModuleFileInfo(StoredSize, StoredModTime,
677 // Record the dependency.
678 unsigned DependsOnID = getModuleFileInfo(*DependsOnFile).ID;
679 getModuleFileInfo(File).Dependencies.push_back(DependsOnID);
685 // Handle the identifier table
686 if (State == ASTBlock && Code == IDENTIFIER_TABLE && Record[0] > 0) {
687 typedef llvm::OnDiskIterableChainedHashTable<
688 InterestingASTIdentifierLookupTrait> InterestingIdentifierTable;
689 std::unique_ptr<InterestingIdentifierTable> Table(
690 InterestingIdentifierTable::Create(
691 (const unsigned char *)Blob.data() + Record[0],
692 (const unsigned char *)Blob.data() + sizeof(uint32_t),
693 (const unsigned char *)Blob.data()));
694 for (InterestingIdentifierTable::data_iterator D = Table->data_begin(),
695 DEnd = Table->data_end();
697 std::pair<StringRef, bool> Ident = *D;
699 InterestingIdentifiers[Ident.first].push_back(ID);
701 (void)InterestingIdentifiers[Ident.first];
706 if (State == DiagnosticOptionsBlock && Code == SIGNATURE)
707 getModuleFileInfo(File).Signature = {
708 {{(uint32_t)Record[0], (uint32_t)Record[1], (uint32_t)Record[2],
709 (uint32_t)Record[3], (uint32_t)Record[4]}}};
711 // We don't care about this record.
714 return llvm::Error::success();
719 /// Trait used to generate the identifier index as an on-disk hash
721 class IdentifierIndexWriterTrait {
723 typedef StringRef key_type;
724 typedef StringRef key_type_ref;
725 typedef SmallVector<unsigned, 2> data_type;
726 typedef const SmallVector<unsigned, 2> &data_type_ref;
727 typedef unsigned hash_value_type;
728 typedef unsigned offset_type;
730 static hash_value_type ComputeHash(key_type_ref Key) {
731 return llvm::djbHash(Key);
734 std::pair<unsigned,unsigned>
735 EmitKeyDataLength(raw_ostream& Out, key_type_ref Key, data_type_ref Data) {
736 using namespace llvm::support;
737 endian::Writer LE(Out, little);
738 unsigned KeyLen = Key.size();
739 unsigned DataLen = Data.size() * 4;
740 LE.write<uint16_t>(KeyLen);
741 LE.write<uint16_t>(DataLen);
742 return std::make_pair(KeyLen, DataLen);
745 void EmitKey(raw_ostream& Out, key_type_ref Key, unsigned KeyLen) {
746 Out.write(Key.data(), KeyLen);
749 void EmitData(raw_ostream& Out, key_type_ref Key, data_type_ref Data,
751 using namespace llvm::support;
752 for (unsigned I = 0, N = Data.size(); I != N; ++I)
753 endian::write<uint32_t>(Out, Data[I], little);
759 bool GlobalModuleIndexBuilder::writeIndex(llvm::BitstreamWriter &Stream) {
760 for (auto MapEntry : ImportedModuleFiles) {
761 auto *File = MapEntry.first;
762 ImportedModuleFileInfo &Info = MapEntry.second;
763 if (getModuleFileInfo(File).Signature) {
764 if (getModuleFileInfo(File).Signature != Info.StoredSignature)
767 } else if (Info.StoredSize != File->getSize() ||
768 Info.StoredModTime != File->getModificationTime())
769 // Verify Size and ModTime.
773 using namespace llvm;
774 llvm::TimeTraceScope TimeScope("Module WriteIndex");
776 // Emit the file header.
777 Stream.Emit((unsigned)'B', 8);
778 Stream.Emit((unsigned)'C', 8);
779 Stream.Emit((unsigned)'G', 8);
780 Stream.Emit((unsigned)'I', 8);
782 // Write the block-info block, which describes the records in this bitcode
784 emitBlockInfoBlock(Stream);
786 Stream.EnterSubblock(GLOBAL_INDEX_BLOCK_ID, 3);
788 // Write the metadata.
789 SmallVector<uint64_t, 2> Record;
790 Record.push_back(CurrentVersion);
791 Stream.EmitRecord(INDEX_METADATA, Record);
793 // Write the set of known module files.
794 for (ModuleFilesMap::iterator M = ModuleFiles.begin(),
795 MEnd = ModuleFiles.end();
798 Record.push_back(M->second.ID);
799 Record.push_back(M->first->getSize());
800 Record.push_back(M->first->getModificationTime());
803 StringRef Name(M->first->getName());
804 Record.push_back(Name.size());
805 Record.append(Name.begin(), Name.end());
808 Record.push_back(M->second.Dependencies.size());
809 Record.append(M->second.Dependencies.begin(), M->second.Dependencies.end());
810 Stream.EmitRecord(MODULE, Record);
813 // Write the identifier -> module file mapping.
815 llvm::OnDiskChainedHashTableGenerator<IdentifierIndexWriterTrait> Generator;
816 IdentifierIndexWriterTrait Trait;
818 // Populate the hash table.
819 for (InterestingIdentifierMap::iterator I = InterestingIdentifiers.begin(),
820 IEnd = InterestingIdentifiers.end();
822 Generator.insert(I->first(), I->second, Trait);
825 // Create the on-disk hash table in a buffer.
826 SmallString<4096> IdentifierTable;
827 uint32_t BucketOffset;
829 using namespace llvm::support;
830 llvm::raw_svector_ostream Out(IdentifierTable);
831 // Make sure that no bucket is at offset 0
832 endian::write<uint32_t>(Out, 0, little);
833 BucketOffset = Generator.Emit(Out, Trait);
836 // Create a blob abbreviation
837 auto Abbrev = std::make_shared<BitCodeAbbrev>();
838 Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_INDEX));
839 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
840 Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
841 unsigned IDTableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
843 // Write the identifier table
844 uint64_t Record[] = {IDENTIFIER_INDEX, BucketOffset};
845 Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
853 GlobalModuleIndex::writeIndex(FileManager &FileMgr,
854 const PCHContainerReader &PCHContainerRdr,
856 llvm::SmallString<128> IndexPath;
858 llvm::sys::path::append(IndexPath, IndexFileName);
860 // Coordinate building the global index file with other processes that might
861 // try to do the same.
862 llvm::LockFileManager Locked(IndexPath);
864 case llvm::LockFileManager::LFS_Error:
865 return llvm::createStringError(std::errc::io_error, "LFS error");
867 case llvm::LockFileManager::LFS_Owned:
868 // We're responsible for building the index ourselves. Do so below.
871 case llvm::LockFileManager::LFS_Shared:
872 // Someone else is responsible for building the index. We don't care
873 // when they finish, so we're done.
874 return llvm::createStringError(std::errc::device_or_resource_busy,
875 "someone else is building the index");
878 // The module index builder.
879 GlobalModuleIndexBuilder Builder(FileMgr, PCHContainerRdr);
881 // Load each of the module files.
883 for (llvm::sys::fs::directory_iterator D(Path, EC), DEnd;
886 // If this isn't a module file, we don't care.
887 if (llvm::sys::path::extension(D->path()) != ".pcm") {
888 // ... unless it's a .pcm.lock file, which indicates that someone is
889 // in the process of rebuilding a module. They'll rebuild the index
890 // at the end of that translation unit, so we don't have to.
891 if (llvm::sys::path::extension(D->path()) == ".pcm.lock")
892 return llvm::createStringError(std::errc::device_or_resource_busy,
893 "someone else is building the index");
898 // If we can't find the module file, skip it.
899 auto ModuleFile = FileMgr.getFile(D->path());
903 // Load this module file.
904 if (llvm::Error Err = Builder.loadModuleFile(*ModuleFile))
908 // The output buffer, into which the global index will be written.
909 SmallVector<char, 16> OutputBuffer;
911 llvm::BitstreamWriter OutputStream(OutputBuffer);
912 if (Builder.writeIndex(OutputStream))
913 return llvm::createStringError(std::errc::io_error,
914 "failed writing index");
917 return llvm::writeFileAtomically(
918 (IndexPath + "-%%%%%%%%").str(), IndexPath,
919 llvm::StringRef(OutputBuffer.data(), OutputBuffer.size()));
923 class GlobalIndexIdentifierIterator : public IdentifierIterator {
924 /// The current position within the identifier lookup table.
925 IdentifierIndexTable::key_iterator Current;
927 /// The end position within the identifier lookup table.
928 IdentifierIndexTable::key_iterator End;
931 explicit GlobalIndexIdentifierIterator(IdentifierIndexTable &Idx) {
932 Current = Idx.key_begin();
936 StringRef Next() override {
940 StringRef Result = *Current;
947 IdentifierIterator *GlobalModuleIndex::createIdentifierIterator() const {
948 IdentifierIndexTable &Table =
949 *static_cast<IdentifierIndexTable *>(IdentifierIndex);
950 return new GlobalIndexIdentifierIterator(Table);