xref: /netbsd-src/external/apache2/llvm/dist/clang/tools/libclang/Indexing.cpp (revision 76c7fc5f6b13ed0b1508e6b313e88e59977ed78e)
1 //===- Indexing.cpp - Higher level API functions --------------------------===//
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 #include "CIndexDiagnostic.h"
10 #include "CIndexer.h"
11 #include "CLog.h"
12 #include "CXCursor.h"
13 #include "CXIndexDataConsumer.h"
14 #include "CXSourceLocation.h"
15 #include "CXString.h"
16 #include "CXTranslationUnit.h"
17 #include "clang/AST/ASTConsumer.h"
18 #include "clang/Frontend/ASTUnit.h"
19 #include "clang/Frontend/CompilerInstance.h"
20 #include "clang/Frontend/CompilerInvocation.h"
21 #include "clang/Frontend/FrontendAction.h"
22 #include "clang/Frontend/MultiplexConsumer.h"
23 #include "clang/Frontend/Utils.h"
24 #include "clang/Index/IndexingAction.h"
25 #include "clang/Lex/HeaderSearch.h"
26 #include "clang/Lex/PPCallbacks.h"
27 #include "clang/Lex/PPConditionalDirectiveRecord.h"
28 #include "clang/Lex/Preprocessor.h"
29 #include "clang/Lex/PreprocessorOptions.h"
30 #include "llvm/Support/CrashRecoveryContext.h"
31 #include "llvm/Support/MemoryBuffer.h"
32 #include <cstdio>
33 #include <mutex>
34 #include <utility>
35 
36 using namespace clang;
37 using namespace clang::index;
38 using namespace cxtu;
39 using namespace cxindex;
40 
41 namespace {
42 
43 //===----------------------------------------------------------------------===//
44 // Skip Parsed Bodies
45 //===----------------------------------------------------------------------===//
46 
47 /// A "region" in source code identified by the file/offset of the
48 /// preprocessor conditional directive that it belongs to.
49 /// Multiple, non-consecutive ranges can be parts of the same region.
50 ///
51 /// As an example of different regions separated by preprocessor directives:
52 ///
53 /// \code
54 ///   #1
55 /// #ifdef BLAH
56 ///   #2
57 /// #ifdef CAKE
58 ///   #3
59 /// #endif
60 ///   #2
61 /// #endif
62 ///   #1
63 /// \endcode
64 ///
65 /// There are 3 regions, with non-consecutive parts:
66 ///   #1 is identified as the beginning of the file
67 ///   #2 is identified as the location of "#ifdef BLAH"
68 ///   #3 is identified as the location of "#ifdef CAKE"
69 ///
70 class PPRegion {
71   llvm::sys::fs::UniqueID UniqueID;
72   time_t ModTime;
73   unsigned Offset;
74 public:
75   PPRegion() : UniqueID(0, 0), ModTime(), Offset() {}
76   PPRegion(llvm::sys::fs::UniqueID UniqueID, unsigned offset, time_t modTime)
77       : UniqueID(UniqueID), ModTime(modTime), Offset(offset) {}
78 
79   const llvm::sys::fs::UniqueID &getUniqueID() const { return UniqueID; }
80   unsigned getOffset() const { return Offset; }
81   time_t getModTime() const { return ModTime; }
82 
83   bool isInvalid() const { return *this == PPRegion(); }
84 
85   friend bool operator==(const PPRegion &lhs, const PPRegion &rhs) {
86     return lhs.UniqueID == rhs.UniqueID && lhs.Offset == rhs.Offset &&
87            lhs.ModTime == rhs.ModTime;
88   }
89 };
90 
91 } // end anonymous namespace
92 
93 namespace llvm {
94 
95   template <>
96   struct DenseMapInfo<PPRegion> {
97     static inline PPRegion getEmptyKey() {
98       return PPRegion(llvm::sys::fs::UniqueID(0, 0), unsigned(-1), 0);
99     }
100     static inline PPRegion getTombstoneKey() {
101       return PPRegion(llvm::sys::fs::UniqueID(0, 0), unsigned(-2), 0);
102     }
103 
104     static unsigned getHashValue(const PPRegion &S) {
105       llvm::FoldingSetNodeID ID;
106       const llvm::sys::fs::UniqueID &UniqueID = S.getUniqueID();
107       ID.AddInteger(UniqueID.getFile());
108       ID.AddInteger(UniqueID.getDevice());
109       ID.AddInteger(S.getOffset());
110       ID.AddInteger(S.getModTime());
111       return ID.ComputeHash();
112     }
113 
114     static bool isEqual(const PPRegion &LHS, const PPRegion &RHS) {
115       return LHS == RHS;
116     }
117   };
118 }
119 
120 namespace {
121 
122 /// Keeps track of function bodies that have already been parsed.
123 ///
124 /// Is thread-safe.
125 class ThreadSafeParsedRegions {
126   mutable std::mutex Mutex;
127   llvm::DenseSet<PPRegion> ParsedRegions;
128 
129 public:
130   ~ThreadSafeParsedRegions() = default;
131 
132   llvm::DenseSet<PPRegion> getParsedRegions() const {
133     std::lock_guard<std::mutex> MG(Mutex);
134     return ParsedRegions;
135   }
136 
137   void addParsedRegions(ArrayRef<PPRegion> Regions) {
138     std::lock_guard<std::mutex> MG(Mutex);
139     ParsedRegions.insert(Regions.begin(), Regions.end());
140   }
141 };
142 
143 /// Provides information whether source locations have already been parsed in
144 /// another FrontendAction.
145 ///
146 /// Is NOT thread-safe.
147 class ParsedSrcLocationsTracker {
148   ThreadSafeParsedRegions &ParsedRegionsStorage;
149   PPConditionalDirectiveRecord &PPRec;
150   Preprocessor &PP;
151 
152   /// Snapshot of the shared state at the point when this instance was
153   /// constructed.
154   llvm::DenseSet<PPRegion> ParsedRegionsSnapshot;
155   /// Regions that were queried during this instance lifetime.
156   SmallVector<PPRegion, 32> NewParsedRegions;
157 
158   /// Caching the last queried region.
159   PPRegion LastRegion;
160   bool LastIsParsed;
161 
162 public:
163   /// Creates snapshot of \p ParsedRegionsStorage.
164   ParsedSrcLocationsTracker(ThreadSafeParsedRegions &ParsedRegionsStorage,
165                             PPConditionalDirectiveRecord &ppRec,
166                             Preprocessor &pp)
167       : ParsedRegionsStorage(ParsedRegionsStorage), PPRec(ppRec), PP(pp),
168         ParsedRegionsSnapshot(ParsedRegionsStorage.getParsedRegions()) {}
169 
170   /// \returns true iff \p Loc has already been parsed.
171   ///
172   /// Can provide false-negative in case the location was parsed after this
173   /// instance had been constructed.
174   bool hasAlredyBeenParsed(SourceLocation Loc, FileID FID,
175                            const FileEntry *FE) {
176     assert(FE);
177     PPRegion region = getRegion(Loc, FID, FE);
178     if (region.isInvalid())
179       return false;
180 
181     // Check common case, consecutive functions in the same region.
182     if (LastRegion == region)
183       return LastIsParsed;
184 
185     LastRegion = region;
186     // Source locations can't be revisited during single TU parsing.
187     // That means if we hit the same region again, it's a different location in
188     // the same region and so the "is parsed" value from the snapshot is still
189     // correct.
190     LastIsParsed = ParsedRegionsSnapshot.count(region);
191     if (!LastIsParsed)
192       NewParsedRegions.emplace_back(std::move(region));
193     return LastIsParsed;
194   }
195 
196   /// Updates ParsedRegionsStorage with newly parsed regions.
197   void syncWithStorage() {
198     ParsedRegionsStorage.addParsedRegions(NewParsedRegions);
199   }
200 
201 private:
202   PPRegion getRegion(SourceLocation Loc, FileID FID, const FileEntry *FE) {
203     assert(FE);
204     auto Bail = [this, FE]() {
205       if (isParsedOnceInclude(FE)) {
206         const llvm::sys::fs::UniqueID &ID = FE->getUniqueID();
207         return PPRegion(ID, 0, FE->getModificationTime());
208       }
209       return PPRegion();
210     };
211 
212     SourceLocation RegionLoc = PPRec.findConditionalDirectiveRegionLoc(Loc);
213     assert(RegionLoc.isFileID());
214     if (RegionLoc.isInvalid())
215       return Bail();
216 
217     FileID RegionFID;
218     unsigned RegionOffset;
219     std::tie(RegionFID, RegionOffset) =
220         PPRec.getSourceManager().getDecomposedLoc(RegionLoc);
221 
222     if (RegionFID != FID)
223       return Bail();
224 
225     const llvm::sys::fs::UniqueID &ID = FE->getUniqueID();
226     return PPRegion(ID, RegionOffset, FE->getModificationTime());
227   }
228 
229   bool isParsedOnceInclude(const FileEntry *FE) {
230     return PP.getHeaderSearchInfo().isFileMultipleIncludeGuarded(FE);
231   }
232 };
233 
234 //===----------------------------------------------------------------------===//
235 // IndexPPCallbacks
236 //===----------------------------------------------------------------------===//
237 
238 class IndexPPCallbacks : public PPCallbacks {
239   Preprocessor &PP;
240   CXIndexDataConsumer &DataConsumer;
241   bool IsMainFileEntered;
242 
243 public:
244   IndexPPCallbacks(Preprocessor &PP, CXIndexDataConsumer &dataConsumer)
245     : PP(PP), DataConsumer(dataConsumer), IsMainFileEntered(false) { }
246 
247   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
248                  SrcMgr::CharacteristicKind FileType, FileID PrevFID) override {
249     if (IsMainFileEntered)
250       return;
251 
252     SourceManager &SM = PP.getSourceManager();
253     SourceLocation MainFileLoc = SM.getLocForStartOfFile(SM.getMainFileID());
254 
255     if (Loc == MainFileLoc && Reason == PPCallbacks::EnterFile) {
256       IsMainFileEntered = true;
257       DataConsumer.enteredMainFile(SM.getFileEntryForID(SM.getMainFileID()));
258     }
259   }
260 
261   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
262                           StringRef FileName, bool IsAngled,
263                           CharSourceRange FilenameRange, const FileEntry *File,
264                           StringRef SearchPath, StringRef RelativePath,
265                           const Module *Imported,
266                           SrcMgr::CharacteristicKind FileType) override {
267     bool isImport = (IncludeTok.is(tok::identifier) &&
268             IncludeTok.getIdentifierInfo()->getPPKeywordID() == tok::pp_import);
269     DataConsumer.ppIncludedFile(HashLoc, FileName, File, isImport, IsAngled,
270                             Imported);
271   }
272 
273   /// MacroDefined - This hook is called whenever a macro definition is seen.
274   void MacroDefined(const Token &Id, const MacroDirective *MD) override {}
275 
276   /// MacroUndefined - This hook is called whenever a macro #undef is seen.
277   /// MI is released immediately following this callback.
278   void MacroUndefined(const Token &MacroNameTok,
279                       const MacroDefinition &MD,
280                       const MacroDirective *UD) override {}
281 
282   /// MacroExpands - This is called by when a macro invocation is found.
283   void MacroExpands(const Token &MacroNameTok, const MacroDefinition &MD,
284                     SourceRange Range, const MacroArgs *Args) override {}
285 
286   /// SourceRangeSkipped - This hook is called when a source range is skipped.
287   /// \param Range The SourceRange that was skipped. The range begins at the
288   /// #if/#else directive and ends after the #endif/#else directive.
289   void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) override {
290   }
291 };
292 
293 //===----------------------------------------------------------------------===//
294 // IndexingConsumer
295 //===----------------------------------------------------------------------===//
296 
297 class IndexingConsumer : public ASTConsumer {
298   CXIndexDataConsumer &DataConsumer;
299 
300 public:
301   IndexingConsumer(CXIndexDataConsumer &dataConsumer,
302                    ParsedSrcLocationsTracker *parsedLocsTracker)
303       : DataConsumer(dataConsumer) {}
304 
305   void Initialize(ASTContext &Context) override {
306     DataConsumer.setASTContext(Context);
307     DataConsumer.startedTranslationUnit();
308   }
309 
310   bool HandleTopLevelDecl(DeclGroupRef DG) override {
311     return !DataConsumer.shouldAbort();
312   }
313 };
314 
315 //===----------------------------------------------------------------------===//
316 // CaptureDiagnosticConsumer
317 //===----------------------------------------------------------------------===//
318 
319 class CaptureDiagnosticConsumer : public DiagnosticConsumer {
320   SmallVector<StoredDiagnostic, 4> Errors;
321 public:
322 
323   void HandleDiagnostic(DiagnosticsEngine::Level level,
324                         const Diagnostic &Info) override {
325     if (level >= DiagnosticsEngine::Error)
326       Errors.push_back(StoredDiagnostic(level, Info));
327   }
328 };
329 
330 //===----------------------------------------------------------------------===//
331 // IndexingFrontendAction
332 //===----------------------------------------------------------------------===//
333 
334 class IndexingFrontendAction : public ASTFrontendAction {
335   std::shared_ptr<CXIndexDataConsumer> DataConsumer;
336   IndexingOptions Opts;
337 
338   ThreadSafeParsedRegions *SKData;
339   std::unique_ptr<ParsedSrcLocationsTracker> ParsedLocsTracker;
340 
341 public:
342   IndexingFrontendAction(std::shared_ptr<CXIndexDataConsumer> dataConsumer,
343                          const IndexingOptions &Opts,
344                          ThreadSafeParsedRegions *skData)
345       : DataConsumer(std::move(dataConsumer)), Opts(Opts), SKData(skData) {}
346 
347   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
348                                                  StringRef InFile) override {
349     PreprocessorOptions &PPOpts = CI.getPreprocessorOpts();
350 
351     if (!PPOpts.ImplicitPCHInclude.empty()) {
352       auto File = CI.getFileManager().getFile(PPOpts.ImplicitPCHInclude);
353       if (File)
354         DataConsumer->importedPCH(*File);
355     }
356 
357     DataConsumer->setASTContext(CI.getASTContext());
358     Preprocessor &PP = CI.getPreprocessor();
359     PP.addPPCallbacks(std::make_unique<IndexPPCallbacks>(PP, *DataConsumer));
360     DataConsumer->setPreprocessor(CI.getPreprocessorPtr());
361 
362     if (SKData) {
363       auto *PPRec = new PPConditionalDirectiveRecord(PP.getSourceManager());
364       PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(PPRec));
365       ParsedLocsTracker =
366           std::make_unique<ParsedSrcLocationsTracker>(*SKData, *PPRec, PP);
367     }
368 
369     std::vector<std::unique_ptr<ASTConsumer>> Consumers;
370     Consumers.push_back(std::make_unique<IndexingConsumer>(
371         *DataConsumer, ParsedLocsTracker.get()));
372     Consumers.push_back(createIndexingASTConsumer(
373         DataConsumer, Opts, CI.getPreprocessorPtr(),
374         [this](const Decl *D) { return this->shouldSkipFunctionBody(D); }));
375     return std::make_unique<MultiplexConsumer>(std::move(Consumers));
376   }
377 
378   bool shouldSkipFunctionBody(const Decl *D) {
379     if (!ParsedLocsTracker) {
380       // Always skip bodies.
381       return true;
382     }
383 
384     const SourceManager &SM = D->getASTContext().getSourceManager();
385     SourceLocation Loc = D->getLocation();
386     if (Loc.isMacroID())
387       return false;
388     if (SM.isInSystemHeader(Loc))
389       return true; // always skip bodies from system headers.
390 
391     FileID FID;
392     unsigned Offset;
393     std::tie(FID, Offset) = SM.getDecomposedLoc(Loc);
394     // Don't skip bodies from main files; this may be revisited.
395     if (SM.getMainFileID() == FID)
396       return false;
397     const FileEntry *FE = SM.getFileEntryForID(FID);
398     if (!FE)
399       return false;
400 
401     return ParsedLocsTracker->hasAlredyBeenParsed(Loc, FID, FE);
402   }
403 
404   TranslationUnitKind getTranslationUnitKind() override {
405     if (DataConsumer->shouldIndexImplicitTemplateInsts())
406       return TU_Complete;
407     else
408       return TU_Prefix;
409   }
410   bool hasCodeCompletionSupport() const override { return false; }
411 
412   void EndSourceFileAction() override {
413     if (ParsedLocsTracker)
414       ParsedLocsTracker->syncWithStorage();
415   }
416 };
417 
418 //===----------------------------------------------------------------------===//
419 // clang_indexSourceFileUnit Implementation
420 //===----------------------------------------------------------------------===//
421 
422 static IndexingOptions getIndexingOptionsFromCXOptions(unsigned index_options) {
423   IndexingOptions IdxOpts;
424   if (index_options & CXIndexOpt_IndexFunctionLocalSymbols)
425     IdxOpts.IndexFunctionLocals = true;
426   if (index_options & CXIndexOpt_IndexImplicitTemplateInstantiations)
427     IdxOpts.IndexImplicitInstantiation = true;
428   return IdxOpts;
429 }
430 
431 struct IndexSessionData {
432   CXIndex CIdx;
433   std::unique_ptr<ThreadSafeParsedRegions> SkipBodyData =
434       std::make_unique<ThreadSafeParsedRegions>();
435 
436   explicit IndexSessionData(CXIndex cIdx) : CIdx(cIdx) {}
437 };
438 
439 } // anonymous namespace
440 
441 static CXErrorCode clang_indexSourceFile_Impl(
442     CXIndexAction cxIdxAction, CXClientData client_data,
443     IndexerCallbacks *client_index_callbacks, unsigned index_callbacks_size,
444     unsigned index_options, const char *source_filename,
445     const char *const *command_line_args, int num_command_line_args,
446     ArrayRef<CXUnsavedFile> unsaved_files, CXTranslationUnit *out_TU,
447     unsigned TU_options) {
448   if (out_TU)
449     *out_TU = nullptr;
450   bool requestedToGetTU = (out_TU != nullptr);
451 
452   if (!cxIdxAction) {
453     return CXError_InvalidArguments;
454   }
455   if (!client_index_callbacks || index_callbacks_size == 0) {
456     return CXError_InvalidArguments;
457   }
458 
459   IndexerCallbacks CB;
460   memset(&CB, 0, sizeof(CB));
461   unsigned ClientCBSize = index_callbacks_size < sizeof(CB)
462                                   ? index_callbacks_size : sizeof(CB);
463   memcpy(&CB, client_index_callbacks, ClientCBSize);
464 
465   IndexSessionData *IdxSession = static_cast<IndexSessionData *>(cxIdxAction);
466   CIndexer *CXXIdx = static_cast<CIndexer *>(IdxSession->CIdx);
467 
468   if (CXXIdx->isOptEnabled(CXGlobalOpt_ThreadBackgroundPriorityForIndexing))
469     setThreadBackgroundPriority();
470 
471   CaptureDiagsKind CaptureDiagnostics = CaptureDiagsKind::All;
472   if (TU_options & CXTranslationUnit_IgnoreNonErrorsFromIncludedFiles)
473     CaptureDiagnostics = CaptureDiagsKind::AllWithoutNonErrorsFromIncludes;
474   if (Logger::isLoggingEnabled())
475     CaptureDiagnostics = CaptureDiagsKind::None;
476 
477   CaptureDiagnosticConsumer *CaptureDiag = nullptr;
478   if (CaptureDiagnostics != CaptureDiagsKind::None)
479     CaptureDiag = new CaptureDiagnosticConsumer();
480 
481   // Configure the diagnostics.
482   IntrusiveRefCntPtr<DiagnosticsEngine>
483     Diags(CompilerInstance::createDiagnostics(new DiagnosticOptions,
484                                               CaptureDiag,
485                                               /*ShouldOwnClient=*/true));
486 
487   // Recover resources if we crash before exiting this function.
488   llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
489     llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
490     DiagCleanup(Diags.get());
491 
492   std::unique_ptr<std::vector<const char *>> Args(
493       new std::vector<const char *>());
494 
495   // Recover resources if we crash before exiting this method.
496   llvm::CrashRecoveryContextCleanupRegistrar<std::vector<const char*> >
497     ArgsCleanup(Args.get());
498 
499   Args->insert(Args->end(), command_line_args,
500                command_line_args + num_command_line_args);
501 
502   // The 'source_filename' argument is optional.  If the caller does not
503   // specify it then it is assumed that the source file is specified
504   // in the actual argument list.
505   // Put the source file after command_line_args otherwise if '-x' flag is
506   // present it will be unused.
507   if (source_filename)
508     Args->push_back(source_filename);
509 
510   std::shared_ptr<CompilerInvocation> CInvok =
511       createInvocationFromCommandLine(*Args, Diags);
512 
513   if (!CInvok)
514     return CXError_Failure;
515 
516   // Recover resources if we crash before exiting this function.
517   llvm::CrashRecoveryContextCleanupRegistrar<
518       std::shared_ptr<CompilerInvocation>,
519       llvm::CrashRecoveryContextDestructorCleanup<
520           std::shared_ptr<CompilerInvocation>>>
521       CInvokCleanup(&CInvok);
522 
523   if (CInvok->getFrontendOpts().Inputs.empty())
524     return CXError_Failure;
525 
526   typedef SmallVector<std::unique_ptr<llvm::MemoryBuffer>, 8> MemBufferOwner;
527   std::unique_ptr<MemBufferOwner> BufOwner(new MemBufferOwner);
528 
529   // Recover resources if we crash before exiting this method.
530   llvm::CrashRecoveryContextCleanupRegistrar<MemBufferOwner> BufOwnerCleanup(
531       BufOwner.get());
532 
533   for (auto &UF : unsaved_files) {
534     std::unique_ptr<llvm::MemoryBuffer> MB =
535         llvm::MemoryBuffer::getMemBufferCopy(getContents(UF), UF.Filename);
536     CInvok->getPreprocessorOpts().addRemappedFile(UF.Filename, MB.get());
537     BufOwner->push_back(std::move(MB));
538   }
539 
540   // Since libclang is primarily used by batch tools dealing with
541   // (often very broken) source code, where spell-checking can have a
542   // significant negative impact on performance (particularly when
543   // precompiled headers are involved), we disable it.
544   CInvok->getLangOpts()->SpellChecking = false;
545 
546   if (index_options & CXIndexOpt_SuppressWarnings)
547     CInvok->getDiagnosticOpts().IgnoreWarnings = true;
548 
549   // Make sure to use the raw module format.
550   CInvok->getHeaderSearchOpts().ModuleFormat =
551     CXXIdx->getPCHContainerOperations()->getRawReader().getFormat();
552 
553   auto Unit = ASTUnit::create(CInvok, Diags, CaptureDiagnostics,
554                               /*UserFilesAreVolatile=*/true);
555   if (!Unit)
556     return CXError_InvalidArguments;
557 
558   auto *UPtr = Unit.get();
559   std::unique_ptr<CXTUOwner> CXTU(
560       new CXTUOwner(MakeCXTranslationUnit(CXXIdx, std::move(Unit))));
561 
562   // Recover resources if we crash before exiting this method.
563   llvm::CrashRecoveryContextCleanupRegistrar<CXTUOwner>
564     CXTUCleanup(CXTU.get());
565 
566   // Enable the skip-parsed-bodies optimization only for C++; this may be
567   // revisited.
568   bool SkipBodies = (index_options & CXIndexOpt_SkipParsedBodiesInSession) &&
569       CInvok->getLangOpts()->CPlusPlus;
570   if (SkipBodies)
571     CInvok->getFrontendOpts().SkipFunctionBodies = true;
572 
573   auto DataConsumer =
574     std::make_shared<CXIndexDataConsumer>(client_data, CB, index_options,
575                                           CXTU->getTU());
576   auto IndexAction = std::make_unique<IndexingFrontendAction>(
577       DataConsumer, getIndexingOptionsFromCXOptions(index_options),
578       SkipBodies ? IdxSession->SkipBodyData.get() : nullptr);
579 
580   // Recover resources if we crash before exiting this method.
581   llvm::CrashRecoveryContextCleanupRegistrar<FrontendAction>
582     IndexActionCleanup(IndexAction.get());
583 
584   bool Persistent = requestedToGetTU;
585   bool OnlyLocalDecls = false;
586   bool PrecompilePreamble = false;
587   bool CreatePreambleOnFirstParse = false;
588   bool CacheCodeCompletionResults = false;
589   PreprocessorOptions &PPOpts = CInvok->getPreprocessorOpts();
590   PPOpts.AllowPCHWithCompilerErrors = true;
591 
592   if (requestedToGetTU) {
593     OnlyLocalDecls = CXXIdx->getOnlyLocalDecls();
594     PrecompilePreamble = TU_options & CXTranslationUnit_PrecompiledPreamble;
595     CreatePreambleOnFirstParse =
596         TU_options & CXTranslationUnit_CreatePreambleOnFirstParse;
597     // FIXME: Add a flag for modules.
598     CacheCodeCompletionResults
599       = TU_options & CXTranslationUnit_CacheCompletionResults;
600   }
601 
602   if (TU_options & CXTranslationUnit_DetailedPreprocessingRecord) {
603     PPOpts.DetailedRecord = true;
604   }
605 
606   if (!requestedToGetTU && !CInvok->getLangOpts()->Modules)
607     PPOpts.DetailedRecord = false;
608 
609   // Unless the user specified that they want the preamble on the first parse
610   // set it up to be created on the first reparse. This makes the first parse
611   // faster, trading for a slower (first) reparse.
612   unsigned PrecompilePreambleAfterNParses =
613       !PrecompilePreamble ? 0 : 2 - CreatePreambleOnFirstParse;
614   DiagnosticErrorTrap DiagTrap(*Diags);
615   bool Success = ASTUnit::LoadFromCompilerInvocationAction(
616       std::move(CInvok), CXXIdx->getPCHContainerOperations(), Diags,
617       IndexAction.get(), UPtr, Persistent, CXXIdx->getClangResourcesPath(),
618       OnlyLocalDecls, CaptureDiagnostics, PrecompilePreambleAfterNParses,
619       CacheCodeCompletionResults,
620       /*IncludeBriefCommentsInCodeCompletion=*/false,
621       /*UserFilesAreVolatile=*/true);
622   if (DiagTrap.hasErrorOccurred() && CXXIdx->getDisplayDiagnostics())
623     printDiagsToStderr(UPtr);
624 
625   if (isASTReadError(UPtr))
626     return CXError_ASTReadError;
627 
628   if (!Success)
629     return CXError_Failure;
630 
631   if (out_TU)
632     *out_TU = CXTU->takeTU();
633 
634   return CXError_Success;
635 }
636 
637 //===----------------------------------------------------------------------===//
638 // clang_indexTranslationUnit Implementation
639 //===----------------------------------------------------------------------===//
640 
641 static void indexPreprocessingRecord(ASTUnit &Unit, CXIndexDataConsumer &IdxCtx) {
642   Preprocessor &PP = Unit.getPreprocessor();
643   if (!PP.getPreprocessingRecord())
644     return;
645 
646   // FIXME: Only deserialize inclusion directives.
647 
648   bool isModuleFile = Unit.isModuleFile();
649   for (PreprocessedEntity *PPE : Unit.getLocalPreprocessingEntities()) {
650     if (InclusionDirective *ID = dyn_cast<InclusionDirective>(PPE)) {
651       SourceLocation Loc = ID->getSourceRange().getBegin();
652       // Modules have synthetic main files as input, give an invalid location
653       // if the location points to such a file.
654       if (isModuleFile && Unit.isInMainFileID(Loc))
655         Loc = SourceLocation();
656       IdxCtx.ppIncludedFile(Loc, ID->getFileName(),
657                             ID->getFile(),
658                             ID->getKind() == InclusionDirective::Import,
659                             !ID->wasInQuotes(), ID->importedModule());
660     }
661   }
662 }
663 
664 static CXErrorCode clang_indexTranslationUnit_Impl(
665     CXIndexAction idxAction, CXClientData client_data,
666     IndexerCallbacks *client_index_callbacks, unsigned index_callbacks_size,
667     unsigned index_options, CXTranslationUnit TU) {
668   // Check arguments.
669   if (isNotUsableTU(TU)) {
670     LOG_BAD_TU(TU);
671     return CXError_InvalidArguments;
672   }
673   if (!client_index_callbacks || index_callbacks_size == 0) {
674     return CXError_InvalidArguments;
675   }
676 
677   CIndexer *CXXIdx = TU->CIdx;
678   if (CXXIdx->isOptEnabled(CXGlobalOpt_ThreadBackgroundPriorityForIndexing))
679     setThreadBackgroundPriority();
680 
681   IndexerCallbacks CB;
682   memset(&CB, 0, sizeof(CB));
683   unsigned ClientCBSize = index_callbacks_size < sizeof(CB)
684                                   ? index_callbacks_size : sizeof(CB);
685   memcpy(&CB, client_index_callbacks, ClientCBSize);
686 
687   CXIndexDataConsumer DataConsumer(client_data, CB, index_options, TU);
688 
689   ASTUnit *Unit = cxtu::getASTUnit(TU);
690   if (!Unit)
691     return CXError_Failure;
692 
693   ASTUnit::ConcurrencyCheck Check(*Unit);
694 
695   if (const FileEntry *PCHFile = Unit->getPCHFile())
696     DataConsumer.importedPCH(PCHFile);
697 
698   FileManager &FileMgr = Unit->getFileManager();
699 
700   if (Unit->getOriginalSourceFileName().empty())
701     DataConsumer.enteredMainFile(nullptr);
702   else if (auto MainFile = FileMgr.getFile(Unit->getOriginalSourceFileName()))
703     DataConsumer.enteredMainFile(*MainFile);
704   else
705     DataConsumer.enteredMainFile(nullptr);
706 
707   DataConsumer.setASTContext(Unit->getASTContext());
708   DataConsumer.startedTranslationUnit();
709 
710   indexPreprocessingRecord(*Unit, DataConsumer);
711   indexASTUnit(*Unit, DataConsumer, getIndexingOptionsFromCXOptions(index_options));
712   DataConsumer.indexDiagnostics();
713 
714   return CXError_Success;
715 }
716 
717 //===----------------------------------------------------------------------===//
718 // libclang public APIs.
719 //===----------------------------------------------------------------------===//
720 
721 int clang_index_isEntityObjCContainerKind(CXIdxEntityKind K) {
722   return CXIdxEntity_ObjCClass <= K && K <= CXIdxEntity_ObjCCategory;
723 }
724 
725 const CXIdxObjCContainerDeclInfo *
726 clang_index_getObjCContainerDeclInfo(const CXIdxDeclInfo *DInfo) {
727   if (!DInfo)
728     return nullptr;
729 
730   const DeclInfo *DI = static_cast<const DeclInfo *>(DInfo);
731   if (const ObjCContainerDeclInfo *
732         ContInfo = dyn_cast<ObjCContainerDeclInfo>(DI))
733     return &ContInfo->ObjCContDeclInfo;
734 
735   return nullptr;
736 }
737 
738 const CXIdxObjCInterfaceDeclInfo *
739 clang_index_getObjCInterfaceDeclInfo(const CXIdxDeclInfo *DInfo) {
740   if (!DInfo)
741     return nullptr;
742 
743   const DeclInfo *DI = static_cast<const DeclInfo *>(DInfo);
744   if (const ObjCInterfaceDeclInfo *
745         InterInfo = dyn_cast<ObjCInterfaceDeclInfo>(DI))
746     return &InterInfo->ObjCInterDeclInfo;
747 
748   return nullptr;
749 }
750 
751 const CXIdxObjCCategoryDeclInfo *
752 clang_index_getObjCCategoryDeclInfo(const CXIdxDeclInfo *DInfo){
753   if (!DInfo)
754     return nullptr;
755 
756   const DeclInfo *DI = static_cast<const DeclInfo *>(DInfo);
757   if (const ObjCCategoryDeclInfo *
758         CatInfo = dyn_cast<ObjCCategoryDeclInfo>(DI))
759     return &CatInfo->ObjCCatDeclInfo;
760 
761   return nullptr;
762 }
763 
764 const CXIdxObjCProtocolRefListInfo *
765 clang_index_getObjCProtocolRefListInfo(const CXIdxDeclInfo *DInfo) {
766   if (!DInfo)
767     return nullptr;
768 
769   const DeclInfo *DI = static_cast<const DeclInfo *>(DInfo);
770 
771   if (const ObjCInterfaceDeclInfo *
772         InterInfo = dyn_cast<ObjCInterfaceDeclInfo>(DI))
773     return InterInfo->ObjCInterDeclInfo.protocols;
774 
775   if (const ObjCProtocolDeclInfo *
776         ProtInfo = dyn_cast<ObjCProtocolDeclInfo>(DI))
777     return &ProtInfo->ObjCProtoRefListInfo;
778 
779   if (const ObjCCategoryDeclInfo *CatInfo = dyn_cast<ObjCCategoryDeclInfo>(DI))
780     return CatInfo->ObjCCatDeclInfo.protocols;
781 
782   return nullptr;
783 }
784 
785 const CXIdxObjCPropertyDeclInfo *
786 clang_index_getObjCPropertyDeclInfo(const CXIdxDeclInfo *DInfo) {
787   if (!DInfo)
788     return nullptr;
789 
790   const DeclInfo *DI = static_cast<const DeclInfo *>(DInfo);
791   if (const ObjCPropertyDeclInfo *PropInfo = dyn_cast<ObjCPropertyDeclInfo>(DI))
792     return &PropInfo->ObjCPropDeclInfo;
793 
794   return nullptr;
795 }
796 
797 const CXIdxIBOutletCollectionAttrInfo *
798 clang_index_getIBOutletCollectionAttrInfo(const CXIdxAttrInfo *AInfo) {
799   if (!AInfo)
800     return nullptr;
801 
802   const AttrInfo *DI = static_cast<const AttrInfo *>(AInfo);
803   if (const IBOutletCollectionInfo *
804         IBInfo = dyn_cast<IBOutletCollectionInfo>(DI))
805     return &IBInfo->IBCollInfo;
806 
807   return nullptr;
808 }
809 
810 const CXIdxCXXClassDeclInfo *
811 clang_index_getCXXClassDeclInfo(const CXIdxDeclInfo *DInfo) {
812   if (!DInfo)
813     return nullptr;
814 
815   const DeclInfo *DI = static_cast<const DeclInfo *>(DInfo);
816   if (const CXXClassDeclInfo *ClassInfo = dyn_cast<CXXClassDeclInfo>(DI))
817     return &ClassInfo->CXXClassInfo;
818 
819   return nullptr;
820 }
821 
822 CXIdxClientContainer
823 clang_index_getClientContainer(const CXIdxContainerInfo *info) {
824   if (!info)
825     return nullptr;
826   const ContainerInfo *Container = static_cast<const ContainerInfo *>(info);
827   return Container->IndexCtx->getClientContainerForDC(Container->DC);
828 }
829 
830 void clang_index_setClientContainer(const CXIdxContainerInfo *info,
831                                     CXIdxClientContainer client) {
832   if (!info)
833     return;
834   const ContainerInfo *Container = static_cast<const ContainerInfo *>(info);
835   Container->IndexCtx->addContainerInMap(Container->DC, client);
836 }
837 
838 CXIdxClientEntity clang_index_getClientEntity(const CXIdxEntityInfo *info) {
839   if (!info)
840     return nullptr;
841   const EntityInfo *Entity = static_cast<const EntityInfo *>(info);
842   return Entity->IndexCtx->getClientEntity(Entity->Dcl);
843 }
844 
845 void clang_index_setClientEntity(const CXIdxEntityInfo *info,
846                                  CXIdxClientEntity client) {
847   if (!info)
848     return;
849   const EntityInfo *Entity = static_cast<const EntityInfo *>(info);
850   Entity->IndexCtx->setClientEntity(Entity->Dcl, client);
851 }
852 
853 CXIndexAction clang_IndexAction_create(CXIndex CIdx) {
854   return new IndexSessionData(CIdx);
855 }
856 
857 void clang_IndexAction_dispose(CXIndexAction idxAction) {
858   if (idxAction)
859     delete static_cast<IndexSessionData *>(idxAction);
860 }
861 
862 int clang_indexSourceFile(CXIndexAction idxAction,
863                           CXClientData client_data,
864                           IndexerCallbacks *index_callbacks,
865                           unsigned index_callbacks_size,
866                           unsigned index_options,
867                           const char *source_filename,
868                           const char * const *command_line_args,
869                           int num_command_line_args,
870                           struct CXUnsavedFile *unsaved_files,
871                           unsigned num_unsaved_files,
872                           CXTranslationUnit *out_TU,
873                           unsigned TU_options) {
874   SmallVector<const char *, 4> Args;
875   Args.push_back("clang");
876   Args.append(command_line_args, command_line_args + num_command_line_args);
877   return clang_indexSourceFileFullArgv(
878       idxAction, client_data, index_callbacks, index_callbacks_size,
879       index_options, source_filename, Args.data(), Args.size(), unsaved_files,
880       num_unsaved_files, out_TU, TU_options);
881 }
882 
883 int clang_indexSourceFileFullArgv(
884     CXIndexAction idxAction, CXClientData client_data,
885     IndexerCallbacks *index_callbacks, unsigned index_callbacks_size,
886     unsigned index_options, const char *source_filename,
887     const char *const *command_line_args, int num_command_line_args,
888     struct CXUnsavedFile *unsaved_files, unsigned num_unsaved_files,
889     CXTranslationUnit *out_TU, unsigned TU_options) {
890   LOG_FUNC_SECTION {
891     *Log << source_filename << ": ";
892     for (int i = 0; i != num_command_line_args; ++i)
893       *Log << command_line_args[i] << " ";
894   }
895 
896   if (num_unsaved_files && !unsaved_files)
897     return CXError_InvalidArguments;
898 
899   CXErrorCode result = CXError_Failure;
900   auto IndexSourceFileImpl = [=, &result]() {
901     result = clang_indexSourceFile_Impl(
902         idxAction, client_data, index_callbacks, index_callbacks_size,
903         index_options, source_filename, command_line_args,
904         num_command_line_args,
905         llvm::makeArrayRef(unsaved_files, num_unsaved_files), out_TU,
906         TU_options);
907   };
908 
909   llvm::CrashRecoveryContext CRC;
910 
911   if (!RunSafely(CRC, IndexSourceFileImpl)) {
912     fprintf(stderr, "libclang: crash detected during indexing source file: {\n");
913     fprintf(stderr, "  'source_filename' : '%s'\n", source_filename);
914     fprintf(stderr, "  'command_line_args' : [");
915     for (int i = 0; i != num_command_line_args; ++i) {
916       if (i)
917         fprintf(stderr, ", ");
918       fprintf(stderr, "'%s'", command_line_args[i]);
919     }
920     fprintf(stderr, "],\n");
921     fprintf(stderr, "  'unsaved_files' : [");
922     for (unsigned i = 0; i != num_unsaved_files; ++i) {
923       if (i)
924         fprintf(stderr, ", ");
925       fprintf(stderr, "('%s', '...', %ld)", unsaved_files[i].Filename,
926               unsaved_files[i].Length);
927     }
928     fprintf(stderr, "],\n");
929     fprintf(stderr, "  'options' : %d,\n", TU_options);
930     fprintf(stderr, "}\n");
931 
932     return 1;
933   } else if (getenv("LIBCLANG_RESOURCE_USAGE")) {
934     if (out_TU)
935       PrintLibclangResourceUsage(*out_TU);
936   }
937 
938   return result;
939 }
940 
941 int clang_indexTranslationUnit(CXIndexAction idxAction,
942                                CXClientData client_data,
943                                IndexerCallbacks *index_callbacks,
944                                unsigned index_callbacks_size,
945                                unsigned index_options,
946                                CXTranslationUnit TU) {
947   LOG_FUNC_SECTION {
948     *Log << TU;
949   }
950 
951   CXErrorCode result;
952   auto IndexTranslationUnitImpl = [=, &result]() {
953     result = clang_indexTranslationUnit_Impl(
954         idxAction, client_data, index_callbacks, index_callbacks_size,
955         index_options, TU);
956   };
957 
958   llvm::CrashRecoveryContext CRC;
959 
960   if (!RunSafely(CRC, IndexTranslationUnitImpl)) {
961     fprintf(stderr, "libclang: crash detected during indexing TU\n");
962 
963     return 1;
964   }
965 
966   return result;
967 }
968 
969 void clang_indexLoc_getFileLocation(CXIdxLoc location,
970                                     CXIdxClientFile *indexFile,
971                                     CXFile *file,
972                                     unsigned *line,
973                                     unsigned *column,
974                                     unsigned *offset) {
975   if (indexFile) *indexFile = nullptr;
976   if (file)   *file = nullptr;
977   if (line)   *line = 0;
978   if (column) *column = 0;
979   if (offset) *offset = 0;
980 
981   SourceLocation Loc = SourceLocation::getFromRawEncoding(location.int_data);
982   if (!location.ptr_data[0] || Loc.isInvalid())
983     return;
984 
985   CXIndexDataConsumer &DataConsumer =
986       *static_cast<CXIndexDataConsumer*>(location.ptr_data[0]);
987   DataConsumer.translateLoc(Loc, indexFile, file, line, column, offset);
988 }
989 
990 CXSourceLocation clang_indexLoc_getCXSourceLocation(CXIdxLoc location) {
991   SourceLocation Loc = SourceLocation::getFromRawEncoding(location.int_data);
992   if (!location.ptr_data[0] || Loc.isInvalid())
993     return clang_getNullLocation();
994 
995   CXIndexDataConsumer &DataConsumer =
996       *static_cast<CXIndexDataConsumer*>(location.ptr_data[0]);
997   return cxloc::translateSourceLocation(DataConsumer.getASTContext(), Loc);
998 }
999