ASTUnit.cpp revision aee526e77657afd1600276450e9c346953ad51d7 
1//===--- ASTUnit.cpp - ASTUnit utility ------------------------------------===//
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// ASTUnit Implementation.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Frontend/ASTUnit.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/TypeOrdering.h"
19#include "clang/AST/StmtVisitor.h"
20#include "clang/Driver/Compilation.h"
21#include "clang/Driver/Driver.h"
22#include "clang/Driver/Job.h"
23#include "clang/Driver/ArgList.h"
24#include "clang/Driver/Options.h"
25#include "clang/Driver/Tool.h"
26#include "clang/Frontend/CompilerInstance.h"
27#include "clang/Frontend/FrontendActions.h"
28#include "clang/Frontend/FrontendDiagnostic.h"
29#include "clang/Frontend/FrontendOptions.h"
30#include "clang/Frontend/Utils.h"
31#include "clang/Serialization/ASTReader.h"
32#include "clang/Serialization/ASTWriter.h"
33#include "clang/Lex/HeaderSearch.h"
34#include "clang/Lex/Preprocessor.h"
35#include "clang/Basic/TargetOptions.h"
36#include "clang/Basic/TargetInfo.h"
37#include "clang/Basic/Diagnostic.h"
38#include "llvm/ADT/ArrayRef.h"
39#include "llvm/ADT/StringExtras.h"
40#include "llvm/ADT/StringSet.h"
41#include "llvm/Support/Atomic.h"
42#include "llvm/Support/MemoryBuffer.h"
43#include "llvm/Support/Host.h"
44#include "llvm/Support/Path.h"
45#include "llvm/Support/raw_ostream.h"
46#include "llvm/Support/Timer.h"
47#include "llvm/Support/FileSystem.h"
48#include "llvm/Support/CrashRecoveryContext.h"
49#include <cstdlib>
50#include <cstdio>
51#include <sys/stat.h>
52using namespace clang;
53
54using llvm::TimeRecord;
55
56namespace {
57  class SimpleTimer {
58    bool WantTiming;
59    TimeRecord Start;
60    std::string Output;
61
62  public:
63    explicit SimpleTimer(bool WantTiming) : WantTiming(WantTiming) {
64      if (WantTiming)
65        Start = TimeRecord::getCurrentTime();
66    }
67
68    void setOutput(const Twine &Output) {
69      if (WantTiming)
70        this->Output = Output.str();
71    }
72
73    ~SimpleTimer() {
74      if (WantTiming) {
75        TimeRecord Elapsed = TimeRecord::getCurrentTime();
76        Elapsed -= Start;
77        llvm::errs() << Output << ':';
78        Elapsed.print(Elapsed, llvm::errs());
79        llvm::errs() << '\n';
80      }
81    }
82  };
83}
84
85/// \brief After failing to build a precompiled preamble (due to
86/// errors in the source that occurs in the preamble), the number of
87/// reparses during which we'll skip even trying to precompile the
88/// preamble.
89const unsigned DefaultPreambleRebuildInterval = 5;
90
91/// \brief Tracks the number of ASTUnit objects that are currently active.
92///
93/// Used for debugging purposes only.
94static llvm::sys::cas_flag ActiveASTUnitObjects;
95
96ASTUnit::ASTUnit(bool _MainFileIsAST)
97  : OnlyLocalDecls(false), CaptureDiagnostics(false),
98    MainFileIsAST(_MainFileIsAST),
99    TUKind(TU_Complete), WantTiming(getenv("LIBCLANG_TIMING")),
100    OwnsRemappedFileBuffers(true),
101    NumStoredDiagnosticsFromDriver(0),
102    ConcurrencyCheckValue(CheckUnlocked),
103    PreambleRebuildCounter(0), SavedMainFileBuffer(0), PreambleBuffer(0),
104    ShouldCacheCodeCompletionResults(false),
105    NestedMacroExpansions(true),
106    CompletionCacheTopLevelHashValue(0),
107    PreambleTopLevelHashValue(0),
108    CurrentTopLevelHashValue(0),
109    UnsafeToFree(false) {
110  if (getenv("LIBCLANG_OBJTRACKING")) {
111    llvm::sys::AtomicIncrement(&ActiveASTUnitObjects);
112    fprintf(stderr, "+++ %d translation units\n", ActiveASTUnitObjects);
113  }
114}
115
116ASTUnit::~ASTUnit() {
117  ConcurrencyCheckValue = CheckLocked;
118  CleanTemporaryFiles();
119  if (!PreambleFile.empty())
120    llvm::sys::Path(PreambleFile).eraseFromDisk();
121
122  // Free the buffers associated with remapped files. We are required to
123  // perform this operation here because we explicitly request that the
124  // compiler instance *not* free these buffers for each invocation of the
125  // parser.
126  if (Invocation.getPtr() && OwnsRemappedFileBuffers) {
127    PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
128    for (PreprocessorOptions::remapped_file_buffer_iterator
129           FB = PPOpts.remapped_file_buffer_begin(),
130           FBEnd = PPOpts.remapped_file_buffer_end();
131         FB != FBEnd;
132         ++FB)
133      delete FB->second;
134  }
135
136  delete SavedMainFileBuffer;
137  delete PreambleBuffer;
138
139  ClearCachedCompletionResults();
140
141  if (getenv("LIBCLANG_OBJTRACKING")) {
142    llvm::sys::AtomicDecrement(&ActiveASTUnitObjects);
143    fprintf(stderr, "--- %d translation units\n", ActiveASTUnitObjects);
144  }
145}
146
147void ASTUnit::CleanTemporaryFiles() {
148  for (unsigned I = 0, N = TemporaryFiles.size(); I != N; ++I)
149    TemporaryFiles[I].eraseFromDisk();
150  TemporaryFiles.clear();
151}
152
153/// \brief Determine the set of code-completion contexts in which this
154/// declaration should be shown.
155static unsigned getDeclShowContexts(NamedDecl *ND,
156                                    const LangOptions &LangOpts,
157                                    bool &IsNestedNameSpecifier) {
158  IsNestedNameSpecifier = false;
159
160  if (isa<UsingShadowDecl>(ND))
161    ND = dyn_cast<NamedDecl>(ND->getUnderlyingDecl());
162  if (!ND)
163    return 0;
164
165  unsigned Contexts = 0;
166  if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) ||
167      isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
168    // Types can appear in these contexts.
169    if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
170      Contexts |= (1 << (CodeCompletionContext::CCC_TopLevel - 1))
171                | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
172                | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
173                | (1 << (CodeCompletionContext::CCC_Statement - 1))
174                | (1 << (CodeCompletionContext::CCC_Type - 1))
175              | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
176
177    // In C++, types can appear in expressions contexts (for functional casts).
178    if (LangOpts.CPlusPlus)
179      Contexts |= (1 << (CodeCompletionContext::CCC_Expression - 1));
180
181    // In Objective-C, message sends can send interfaces. In Objective-C++,
182    // all types are available due to functional casts.
183    if (LangOpts.CPlusPlus || isa<ObjCInterfaceDecl>(ND))
184      Contexts |= (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
185
186    // In Objective-C, you can only be a subclass of another Objective-C class
187    if (isa<ObjCInterfaceDecl>(ND))
188      Contexts |= (1 << (CodeCompletionContext::CCC_ObjCInterfaceName - 1));
189
190    // Deal with tag names.
191    if (isa<EnumDecl>(ND)) {
192      Contexts |= (1 << (CodeCompletionContext::CCC_EnumTag - 1));
193
194      // Part of the nested-name-specifier in C++0x.
195      if (LangOpts.CPlusPlus0x)
196        IsNestedNameSpecifier = true;
197    } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
198      if (Record->isUnion())
199        Contexts |= (1 << (CodeCompletionContext::CCC_UnionTag - 1));
200      else
201        Contexts |= (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
202
203      if (LangOpts.CPlusPlus)
204        IsNestedNameSpecifier = true;
205    } else if (isa<ClassTemplateDecl>(ND))
206      IsNestedNameSpecifier = true;
207  } else if (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)) {
208    // Values can appear in these contexts.
209    Contexts = (1 << (CodeCompletionContext::CCC_Statement - 1))
210             | (1 << (CodeCompletionContext::CCC_Expression - 1))
211             | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
212             | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1));
213  } else if (isa<ObjCProtocolDecl>(ND)) {
214    Contexts = (1 << (CodeCompletionContext::CCC_ObjCProtocolName - 1));
215  } else if (isa<ObjCCategoryDecl>(ND)) {
216    Contexts = (1 << (CodeCompletionContext::CCC_ObjCCategoryName - 1));
217  } else if (isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND)) {
218    Contexts = (1 << (CodeCompletionContext::CCC_Namespace - 1));
219
220    // Part of the nested-name-specifier.
221    IsNestedNameSpecifier = true;
222  }
223
224  return Contexts;
225}
226
227void ASTUnit::CacheCodeCompletionResults() {
228  if (!TheSema)
229    return;
230
231  SimpleTimer Timer(WantTiming);
232  Timer.setOutput("Cache global code completions for " + getMainFileName());
233
234  // Clear out the previous results.
235  ClearCachedCompletionResults();
236
237  // Gather the set of global code completions.
238  typedef CodeCompletionResult Result;
239  SmallVector<Result, 8> Results;
240  CachedCompletionAllocator = new GlobalCodeCompletionAllocator;
241  TheSema->GatherGlobalCodeCompletions(*CachedCompletionAllocator, Results);
242
243  // Translate global code completions into cached completions.
244  llvm::DenseMap<CanQualType, unsigned> CompletionTypes;
245
246  for (unsigned I = 0, N = Results.size(); I != N; ++I) {
247    switch (Results[I].Kind) {
248    case Result::RK_Declaration: {
249      bool IsNestedNameSpecifier = false;
250      CachedCodeCompletionResult CachedResult;
251      CachedResult.Completion = Results[I].CreateCodeCompletionString(*TheSema,
252                                                    *CachedCompletionAllocator);
253      CachedResult.ShowInContexts = getDeclShowContexts(Results[I].Declaration,
254                                                        Ctx->getLangOptions(),
255                                                        IsNestedNameSpecifier);
256      CachedResult.Priority = Results[I].Priority;
257      CachedResult.Kind = Results[I].CursorKind;
258      CachedResult.Availability = Results[I].Availability;
259
260      // Keep track of the type of this completion in an ASTContext-agnostic
261      // way.
262      QualType UsageType = getDeclUsageType(*Ctx, Results[I].Declaration);
263      if (UsageType.isNull()) {
264        CachedResult.TypeClass = STC_Void;
265        CachedResult.Type = 0;
266      } else {
267        CanQualType CanUsageType
268          = Ctx->getCanonicalType(UsageType.getUnqualifiedType());
269        CachedResult.TypeClass = getSimplifiedTypeClass(CanUsageType);
270
271        // Determine whether we have already seen this type. If so, we save
272        // ourselves the work of formatting the type string by using the
273        // temporary, CanQualType-based hash table to find the associated value.
274        unsigned &TypeValue = CompletionTypes[CanUsageType];
275        if (TypeValue == 0) {
276          TypeValue = CompletionTypes.size();
277          CachedCompletionTypes[QualType(CanUsageType).getAsString()]
278            = TypeValue;
279        }
280
281        CachedResult.Type = TypeValue;
282      }
283
284      CachedCompletionResults.push_back(CachedResult);
285
286      /// Handle nested-name-specifiers in C++.
287      if (TheSema->Context.getLangOptions().CPlusPlus &&
288          IsNestedNameSpecifier && !Results[I].StartsNestedNameSpecifier) {
289        // The contexts in which a nested-name-specifier can appear in C++.
290        unsigned NNSContexts
291          = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
292          | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
293          | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
294          | (1 << (CodeCompletionContext::CCC_Statement - 1))
295          | (1 << (CodeCompletionContext::CCC_Expression - 1))
296          | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
297          | (1 << (CodeCompletionContext::CCC_EnumTag - 1))
298          | (1 << (CodeCompletionContext::CCC_UnionTag - 1))
299          | (1 << (CodeCompletionContext::CCC_ClassOrStructTag - 1))
300          | (1 << (CodeCompletionContext::CCC_Type - 1))
301          | (1 << (CodeCompletionContext::CCC_PotentiallyQualifiedName - 1))
302          | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1));
303
304        if (isa<NamespaceDecl>(Results[I].Declaration) ||
305            isa<NamespaceAliasDecl>(Results[I].Declaration))
306          NNSContexts |= (1 << (CodeCompletionContext::CCC_Namespace - 1));
307
308        if (unsigned RemainingContexts
309                                = NNSContexts & ~CachedResult.ShowInContexts) {
310          // If there any contexts where this completion can be a
311          // nested-name-specifier but isn't already an option, create a
312          // nested-name-specifier completion.
313          Results[I].StartsNestedNameSpecifier = true;
314          CachedResult.Completion
315            = Results[I].CreateCodeCompletionString(*TheSema,
316                                                    *CachedCompletionAllocator);
317          CachedResult.ShowInContexts = RemainingContexts;
318          CachedResult.Priority = CCP_NestedNameSpecifier;
319          CachedResult.TypeClass = STC_Void;
320          CachedResult.Type = 0;
321          CachedCompletionResults.push_back(CachedResult);
322        }
323      }
324      break;
325    }
326
327    case Result::RK_Keyword:
328    case Result::RK_Pattern:
329      // Ignore keywords and patterns; we don't care, since they are so
330      // easily regenerated.
331      break;
332
333    case Result::RK_Macro: {
334      CachedCodeCompletionResult CachedResult;
335      CachedResult.Completion
336        = Results[I].CreateCodeCompletionString(*TheSema,
337                                                *CachedCompletionAllocator);
338      CachedResult.ShowInContexts
339        = (1 << (CodeCompletionContext::CCC_TopLevel - 1))
340        | (1 << (CodeCompletionContext::CCC_ObjCInterface - 1))
341        | (1 << (CodeCompletionContext::CCC_ObjCImplementation - 1))
342        | (1 << (CodeCompletionContext::CCC_ObjCIvarList - 1))
343        | (1 << (CodeCompletionContext::CCC_ClassStructUnion - 1))
344        | (1 << (CodeCompletionContext::CCC_Statement - 1))
345        | (1 << (CodeCompletionContext::CCC_Expression - 1))
346        | (1 << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
347        | (1 << (CodeCompletionContext::CCC_MacroNameUse - 1))
348        | (1 << (CodeCompletionContext::CCC_PreprocessorExpression - 1))
349        | (1 << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
350        | (1 << (CodeCompletionContext::CCC_OtherWithMacros - 1));
351
352      CachedResult.Priority = Results[I].Priority;
353      CachedResult.Kind = Results[I].CursorKind;
354      CachedResult.Availability = Results[I].Availability;
355      CachedResult.TypeClass = STC_Void;
356      CachedResult.Type = 0;
357      CachedCompletionResults.push_back(CachedResult);
358      break;
359    }
360    }
361  }
362
363  // Save the current top-level hash value.
364  CompletionCacheTopLevelHashValue = CurrentTopLevelHashValue;
365}
366
367void ASTUnit::ClearCachedCompletionResults() {
368  CachedCompletionResults.clear();
369  CachedCompletionTypes.clear();
370  CachedCompletionAllocator = 0;
371}
372
373namespace {
374
375/// \brief Gathers information from ASTReader that will be used to initialize
376/// a Preprocessor.
377class ASTInfoCollector : public ASTReaderListener {
378  Preprocessor &PP;
379  ASTContext &Context;
380  LangOptions &LangOpt;
381  HeaderSearch &HSI;
382  llvm::IntrusiveRefCntPtr<TargetInfo> &Target;
383  std::string &Predefines;
384  unsigned &Counter;
385
386  unsigned NumHeaderInfos;
387
388  bool InitializedLanguage;
389public:
390  ASTInfoCollector(Preprocessor &PP, ASTContext &Context, LangOptions &LangOpt,
391                   HeaderSearch &HSI,
392                   llvm::IntrusiveRefCntPtr<TargetInfo> &Target,
393                   std::string &Predefines,
394                   unsigned &Counter)
395    : PP(PP), Context(Context), LangOpt(LangOpt), HSI(HSI), Target(Target),
396      Predefines(Predefines), Counter(Counter), NumHeaderInfos(0),
397      InitializedLanguage(false) {}
398
399  virtual bool ReadLanguageOptions(const LangOptions &LangOpts) {
400    if (InitializedLanguage)
401      return false;
402
403    LangOpt = LangOpts;
404
405    // Initialize the preprocessor.
406    PP.Initialize(*Target);
407
408    // Initialize the ASTContext
409    Context.InitBuiltinTypes(*Target);
410
411    InitializedLanguage = true;
412    return false;
413  }
414
415  virtual bool ReadTargetTriple(StringRef Triple) {
416    // If we've already initialized the target, don't do it again.
417    if (Target)
418      return false;
419
420    // FIXME: This is broken, we should store the TargetOptions in the AST file.
421    TargetOptions TargetOpts;
422    TargetOpts.ABI = "";
423    TargetOpts.CXXABI = "";
424    TargetOpts.CPU = "";
425    TargetOpts.Features.clear();
426    TargetOpts.Triple = Triple;
427    Target = TargetInfo::CreateTargetInfo(PP.getDiagnostics(), TargetOpts);
428    return false;
429  }
430
431  virtual bool ReadPredefinesBuffer(const PCHPredefinesBlocks &Buffers,
432                                    StringRef OriginalFileName,
433                                    std::string &SuggestedPredefines,
434                                    FileManager &FileMgr) {
435    Predefines = Buffers[0].Data;
436    for (unsigned I = 1, N = Buffers.size(); I != N; ++I) {
437      Predefines += Buffers[I].Data;
438    }
439    return false;
440  }
441
442  virtual void ReadHeaderFileInfo(const HeaderFileInfo &HFI, unsigned ID) {
443    HSI.setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
444  }
445
446  virtual void ReadCounter(unsigned Value) {
447    Counter = Value;
448  }
449};
450
451class StoredDiagnosticConsumer : public DiagnosticConsumer {
452  SmallVectorImpl<StoredDiagnostic> &StoredDiags;
453
454public:
455  explicit StoredDiagnosticConsumer(
456                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
457    : StoredDiags(StoredDiags) { }
458
459  virtual void HandleDiagnostic(DiagnosticsEngine::Level Level,
460                                const Diagnostic &Info);
461
462  DiagnosticConsumer *clone(DiagnosticsEngine &Diags) const {
463    // Just drop any diagnostics that come from cloned consumers; they'll
464    // have different source managers anyway.
465    return new IgnoringDiagConsumer();
466  }
467};
468
469/// \brief RAII object that optionally captures diagnostics, if
470/// there is no diagnostic client to capture them already.
471class CaptureDroppedDiagnostics {
472  DiagnosticsEngine &Diags;
473  StoredDiagnosticConsumer Client;
474  DiagnosticConsumer *PreviousClient;
475
476public:
477  CaptureDroppedDiagnostics(bool RequestCapture, DiagnosticsEngine &Diags,
478                          SmallVectorImpl<StoredDiagnostic> &StoredDiags)
479    : Diags(Diags), Client(StoredDiags), PreviousClient(0)
480  {
481    if (RequestCapture || Diags.getClient() == 0) {
482      PreviousClient = Diags.takeClient();
483      Diags.setClient(&Client);
484    }
485  }
486
487  ~CaptureDroppedDiagnostics() {
488    if (Diags.getClient() == &Client) {
489      Diags.takeClient();
490      Diags.setClient(PreviousClient);
491    }
492  }
493};
494
495} // anonymous namespace
496
497void StoredDiagnosticConsumer::HandleDiagnostic(DiagnosticsEngine::Level Level,
498                                              const Diagnostic &Info) {
499  // Default implementation (Warnings/errors count).
500  DiagnosticConsumer::HandleDiagnostic(Level, Info);
501
502  StoredDiags.push_back(StoredDiagnostic(Level, Info));
503}
504
505const std::string &ASTUnit::getOriginalSourceFileName() {
506  return OriginalSourceFile;
507}
508
509llvm::MemoryBuffer *ASTUnit::getBufferForFile(StringRef Filename,
510                                              std::string *ErrorStr) {
511  assert(FileMgr);
512  return FileMgr->getBufferForFile(Filename, ErrorStr);
513}
514
515/// \brief Configure the diagnostics object for use with ASTUnit.
516void ASTUnit::ConfigureDiags(llvm::IntrusiveRefCntPtr<DiagnosticsEngine> &Diags,
517                             const char **ArgBegin, const char **ArgEnd,
518                             ASTUnit &AST, bool CaptureDiagnostics) {
519  if (!Diags.getPtr()) {
520    // No diagnostics engine was provided, so create our own diagnostics object
521    // with the default options.
522    DiagnosticOptions DiagOpts;
523    DiagnosticConsumer *Client = 0;
524    if (CaptureDiagnostics)
525      Client = new StoredDiagnosticConsumer(AST.StoredDiagnostics);
526    Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd- ArgBegin,
527                                                ArgBegin, Client);
528  } else if (CaptureDiagnostics) {
529    Diags->setClient(new StoredDiagnosticConsumer(AST.StoredDiagnostics));
530  }
531}
532
533ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
534                              llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
535                                  const FileSystemOptions &FileSystemOpts,
536                                  bool OnlyLocalDecls,
537                                  RemappedFile *RemappedFiles,
538                                  unsigned NumRemappedFiles,
539                                  bool CaptureDiagnostics) {
540  llvm::OwningPtr<ASTUnit> AST(new ASTUnit(true));
541
542  // Recover resources if we crash before exiting this method.
543  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
544    ASTUnitCleanup(AST.get());
545  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
546    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
547    DiagCleanup(Diags.getPtr());
548
549  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
550
551  AST->OnlyLocalDecls = OnlyLocalDecls;
552  AST->CaptureDiagnostics = CaptureDiagnostics;
553  AST->Diagnostics = Diags;
554  AST->FileMgr = new FileManager(FileSystemOpts);
555  AST->SourceMgr = new SourceManager(AST->getDiagnostics(),
556                                     AST->getFileManager());
557  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager()));
558
559  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
560    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
561    if (const llvm::MemoryBuffer *
562          memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
563      // Create the file entry for the file that we're mapping from.
564      const FileEntry *FromFile
565        = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
566                                               memBuf->getBufferSize(),
567                                               0);
568      if (!FromFile) {
569        AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
570          << RemappedFiles[I].first;
571        delete memBuf;
572        continue;
573      }
574
575      // Override the contents of the "from" file with the contents of
576      // the "to" file.
577      AST->getSourceManager().overrideFileContents(FromFile, memBuf);
578
579    } else {
580      const char *fname = fileOrBuf.get<const char *>();
581      const FileEntry *ToFile = AST->FileMgr->getFile(fname);
582      if (!ToFile) {
583        AST->getDiagnostics().Report(diag::err_fe_remap_missing_to_file)
584        << RemappedFiles[I].first << fname;
585        continue;
586      }
587
588      // Create the file entry for the file that we're mapping from.
589      const FileEntry *FromFile
590        = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
591                                               ToFile->getSize(),
592                                               0);
593      if (!FromFile) {
594        AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
595          << RemappedFiles[I].first;
596        delete memBuf;
597        continue;
598      }
599
600      // Override the contents of the "from" file with the contents of
601      // the "to" file.
602      AST->getSourceManager().overrideFileContents(FromFile, ToFile);
603    }
604  }
605
606  // Gather Info for preprocessor construction later on.
607
608  HeaderSearch &HeaderInfo = *AST->HeaderInfo.get();
609  std::string Predefines;
610  unsigned Counter;
611
612  llvm::OwningPtr<ASTReader> Reader;
613
614  AST->PP = new Preprocessor(AST->getDiagnostics(), AST->ASTFileLangOpts,
615                             /*Target=*/0, AST->getSourceManager(), HeaderInfo,
616                             *AST,
617                             /*IILookup=*/0,
618                             /*OwnsHeaderSearch=*/false,
619                             /*DelayInitialization=*/true);
620  Preprocessor &PP = *AST->PP;
621
622  AST->Ctx = new ASTContext(AST->ASTFileLangOpts,
623                            AST->getSourceManager(),
624                            /*Target=*/0,
625                            PP.getIdentifierTable(),
626                            PP.getSelectorTable(),
627                            PP.getBuiltinInfo(),
628                            /* size_reserve = */0,
629                            /*DelayInitialization=*/true);
630  ASTContext &Context = *AST->Ctx;
631
632  Reader.reset(new ASTReader(PP, Context));
633
634  // Recover resources if we crash before exiting this method.
635  llvm::CrashRecoveryContextCleanupRegistrar<ASTReader>
636    ReaderCleanup(Reader.get());
637
638  Reader->setListener(new ASTInfoCollector(*AST->PP, Context,
639                                           AST->ASTFileLangOpts, HeaderInfo,
640                                           AST->Target, Predefines, Counter));
641
642  switch (Reader->ReadAST(Filename, serialization::MK_MainFile)) {
643  case ASTReader::Success:
644    break;
645
646  case ASTReader::Failure:
647  case ASTReader::IgnorePCH:
648    AST->getDiagnostics().Report(diag::err_fe_unable_to_load_pch);
649    return NULL;
650  }
651
652  AST->OriginalSourceFile = Reader->getOriginalSourceFile();
653
654  PP.setPredefines(Reader->getSuggestedPredefines());
655  PP.setCounterValue(Counter);
656
657  // Attach the AST reader to the AST context as an external AST
658  // source, so that declarations will be deserialized from the
659  // AST file as needed.
660  ASTReader *ReaderPtr = Reader.get();
661  llvm::OwningPtr<ExternalASTSource> Source(Reader.take());
662
663  // Unregister the cleanup for ASTReader.  It will get cleaned up
664  // by the ASTUnit cleanup.
665  ReaderCleanup.unregister();
666
667  Context.setExternalSource(Source);
668
669  // Create an AST consumer, even though it isn't used.
670  AST->Consumer.reset(new ASTConsumer);
671
672  // Create a semantic analysis object and tell the AST reader about it.
673  AST->TheSema.reset(new Sema(PP, Context, *AST->Consumer));
674  AST->TheSema->Initialize();
675  ReaderPtr->InitializeSema(*AST->TheSema);
676
677  return AST.take();
678}
679
680namespace {
681
682/// \brief Preprocessor callback class that updates a hash value with the names
683/// of all macros that have been defined by the translation unit.
684class MacroDefinitionTrackerPPCallbacks : public PPCallbacks {
685  unsigned &Hash;
686
687public:
688  explicit MacroDefinitionTrackerPPCallbacks(unsigned &Hash) : Hash(Hash) { }
689
690  virtual void MacroDefined(const Token &MacroNameTok, const MacroInfo *MI) {
691    Hash = llvm::HashString(MacroNameTok.getIdentifierInfo()->getName(), Hash);
692  }
693};
694
695/// \brief Add the given declaration to the hash of all top-level entities.
696void AddTopLevelDeclarationToHash(Decl *D, unsigned &Hash) {
697  if (!D)
698    return;
699
700  DeclContext *DC = D->getDeclContext();
701  if (!DC)
702    return;
703
704  if (!(DC->isTranslationUnit() || DC->getLookupParent()->isTranslationUnit()))
705    return;
706
707  if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
708    if (ND->getIdentifier())
709      Hash = llvm::HashString(ND->getIdentifier()->getName(), Hash);
710    else if (DeclarationName Name = ND->getDeclName()) {
711      std::string NameStr = Name.getAsString();
712      Hash = llvm::HashString(NameStr, Hash);
713    }
714    return;
715  }
716
717  if (ObjCForwardProtocolDecl *Forward
718      = dyn_cast<ObjCForwardProtocolDecl>(D)) {
719    for (ObjCForwardProtocolDecl::protocol_iterator
720         P = Forward->protocol_begin(),
721         PEnd = Forward->protocol_end();
722         P != PEnd; ++P)
723      AddTopLevelDeclarationToHash(*P, Hash);
724    return;
725  }
726
727  if (ObjCClassDecl *Class = dyn_cast<ObjCClassDecl>(D)) {
728    AddTopLevelDeclarationToHash(Class->getForwardInterfaceDecl(), Hash);
729    return;
730  }
731}
732
733class TopLevelDeclTrackerConsumer : public ASTConsumer {
734  ASTUnit &Unit;
735  unsigned &Hash;
736
737public:
738  TopLevelDeclTrackerConsumer(ASTUnit &_Unit, unsigned &Hash)
739    : Unit(_Unit), Hash(Hash) {
740    Hash = 0;
741  }
742
743  void HandleTopLevelDecl(DeclGroupRef D) {
744    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
745      Decl *D = *it;
746      // FIXME: Currently ObjC method declarations are incorrectly being
747      // reported as top-level declarations, even though their DeclContext
748      // is the containing ObjC @interface/@implementation.  This is a
749      // fundamental problem in the parser right now.
750      if (isa<ObjCMethodDecl>(D))
751        continue;
752
753      AddTopLevelDeclarationToHash(D, Hash);
754      Unit.addTopLevelDecl(D);
755    }
756  }
757
758  // We're not interested in "interesting" decls.
759  void HandleInterestingDecl(DeclGroupRef) {}
760};
761
762class TopLevelDeclTrackerAction : public ASTFrontendAction {
763public:
764  ASTUnit &Unit;
765
766  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
767                                         StringRef InFile) {
768    CI.getPreprocessor().addPPCallbacks(
769     new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
770    return new TopLevelDeclTrackerConsumer(Unit,
771                                           Unit.getCurrentTopLevelHashValue());
772  }
773
774public:
775  TopLevelDeclTrackerAction(ASTUnit &_Unit) : Unit(_Unit) {}
776
777  virtual bool hasCodeCompletionSupport() const { return false; }
778  virtual TranslationUnitKind getTranslationUnitKind()  {
779    return Unit.getTranslationUnitKind();
780  }
781};
782
783class PrecompilePreambleConsumer : public PCHGenerator {
784  ASTUnit &Unit;
785  unsigned &Hash;
786  std::vector<Decl *> TopLevelDecls;
787
788public:
789  PrecompilePreambleConsumer(ASTUnit &Unit, const Preprocessor &PP,
790                             StringRef isysroot, raw_ostream *Out)
791    : PCHGenerator(PP, "", /*IsModule=*/false, isysroot, Out), Unit(Unit),
792      Hash(Unit.getCurrentTopLevelHashValue()) {
793    Hash = 0;
794  }
795
796  virtual void HandleTopLevelDecl(DeclGroupRef D) {
797    for (DeclGroupRef::iterator it = D.begin(), ie = D.end(); it != ie; ++it) {
798      Decl *D = *it;
799      // FIXME: Currently ObjC method declarations are incorrectly being
800      // reported as top-level declarations, even though their DeclContext
801      // is the containing ObjC @interface/@implementation.  This is a
802      // fundamental problem in the parser right now.
803      if (isa<ObjCMethodDecl>(D))
804        continue;
805      AddTopLevelDeclarationToHash(D, Hash);
806      TopLevelDecls.push_back(D);
807    }
808  }
809
810  virtual void HandleTranslationUnit(ASTContext &Ctx) {
811    PCHGenerator::HandleTranslationUnit(Ctx);
812    if (!Unit.getDiagnostics().hasErrorOccurred()) {
813      // Translate the top-level declarations we captured during
814      // parsing into declaration IDs in the precompiled
815      // preamble. This will allow us to deserialize those top-level
816      // declarations when requested.
817      for (unsigned I = 0, N = TopLevelDecls.size(); I != N; ++I)
818        Unit.addTopLevelDeclFromPreamble(
819                                      getWriter().getDeclID(TopLevelDecls[I]));
820    }
821  }
822};
823
824class PrecompilePreambleAction : public ASTFrontendAction {
825  ASTUnit &Unit;
826
827public:
828  explicit PrecompilePreambleAction(ASTUnit &Unit) : Unit(Unit) {}
829
830  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
831                                         StringRef InFile) {
832    std::string Sysroot;
833    std::string OutputFile;
834    raw_ostream *OS = 0;
835    if (GeneratePCHAction::ComputeASTConsumerArguments(CI, InFile, Sysroot,
836                                                       OutputFile,
837                                                       OS))
838      return 0;
839
840    if (!CI.getFrontendOpts().RelocatablePCH)
841      Sysroot.clear();
842
843    CI.getPreprocessor().addPPCallbacks(
844     new MacroDefinitionTrackerPPCallbacks(Unit.getCurrentTopLevelHashValue()));
845    return new PrecompilePreambleConsumer(Unit, CI.getPreprocessor(), Sysroot,
846                                          OS);
847  }
848
849  virtual bool hasCodeCompletionSupport() const { return false; }
850  virtual bool hasASTFileSupport() const { return false; }
851  virtual TranslationUnitKind getTranslationUnitKind() { return TU_Prefix; }
852};
853
854}
855
856/// Parse the source file into a translation unit using the given compiler
857/// invocation, replacing the current translation unit.
858///
859/// \returns True if a failure occurred that causes the ASTUnit not to
860/// contain any translation-unit information, false otherwise.
861bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
862  delete SavedMainFileBuffer;
863  SavedMainFileBuffer = 0;
864
865  if (!Invocation) {
866    delete OverrideMainBuffer;
867    return true;
868  }
869
870  // Create the compiler instance to use for building the AST.
871  llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
872
873  // Recover resources if we crash before exiting this method.
874  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
875    CICleanup(Clang.get());
876
877  llvm::IntrusiveRefCntPtr<CompilerInvocation>
878    CCInvocation(new CompilerInvocation(*Invocation));
879
880  Clang->setInvocation(CCInvocation.getPtr());
881  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
882
883  // Set up diagnostics, capturing any diagnostics that would
884  // otherwise be dropped.
885  Clang->setDiagnostics(&getDiagnostics());
886
887  // Create the target instance.
888  Clang->getTargetOpts().Features = TargetFeatures;
889  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
890                   Clang->getTargetOpts()));
891  if (!Clang->hasTarget()) {
892    delete OverrideMainBuffer;
893    return true;
894  }
895
896  // Inform the target of the language options.
897  //
898  // FIXME: We shouldn't need to do this, the target should be immutable once
899  // created. This complexity should be lifted elsewhere.
900  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
901
902  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
903         "Invocation must have exactly one source file!");
904  assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
905         "FIXME: AST inputs not yet supported here!");
906  assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
907         "IR inputs not support here!");
908
909  // Configure the various subsystems.
910  // FIXME: Should we retain the previous file manager?
911  FileSystemOpts = Clang->getFileSystemOpts();
912  FileMgr = new FileManager(FileSystemOpts);
913  SourceMgr = new SourceManager(getDiagnostics(), *FileMgr);
914  TheSema.reset();
915  Ctx = 0;
916  PP = 0;
917
918  // Clear out old caches and data.
919  TopLevelDecls.clear();
920  CleanTemporaryFiles();
921
922  if (!OverrideMainBuffer) {
923    StoredDiagnostics.erase(
924                    StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
925                            StoredDiagnostics.end());
926    TopLevelDeclsInPreamble.clear();
927  }
928
929  // Create a file manager object to provide access to and cache the filesystem.
930  Clang->setFileManager(&getFileManager());
931
932  // Create the source manager.
933  Clang->setSourceManager(&getSourceManager());
934
935  // If the main file has been overridden due to the use of a preamble,
936  // make that override happen and introduce the preamble.
937  PreprocessorOptions &PreprocessorOpts = Clang->getPreprocessorOpts();
938  PreprocessorOpts.DetailedRecordIncludesNestedMacroExpansions
939    = NestedMacroExpansions;
940  if (OverrideMainBuffer) {
941    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
942    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
943    PreprocessorOpts.PrecompiledPreambleBytes.second
944                                                    = PreambleEndsAtStartOfLine;
945    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
946    PreprocessorOpts.DisablePCHValidation = true;
947
948    // The stored diagnostic has the old source manager in it; update
949    // the locations to refer into the new source manager. Since we've
950    // been careful to make sure that the source manager's state
951    // before and after are identical, so that we can reuse the source
952    // location itself.
953    for (unsigned I = NumStoredDiagnosticsFromDriver,
954                  N = StoredDiagnostics.size();
955         I < N; ++I) {
956      FullSourceLoc Loc(StoredDiagnostics[I].getLocation(),
957                        getSourceManager());
958      StoredDiagnostics[I].setLocation(Loc);
959    }
960
961    // Keep track of the override buffer;
962    SavedMainFileBuffer = OverrideMainBuffer;
963  }
964
965  llvm::OwningPtr<TopLevelDeclTrackerAction> Act(
966    new TopLevelDeclTrackerAction(*this));
967
968  // Recover resources if we crash before exiting this method.
969  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
970    ActCleanup(Act.get());
971
972  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0].second,
973                            Clang->getFrontendOpts().Inputs[0].first))
974    goto error;
975
976  if (OverrideMainBuffer) {
977    std::string ModName = PreambleFile;
978    TranslateStoredDiagnostics(Clang->getModuleManager(), ModName,
979                               getSourceManager(), PreambleDiagnostics,
980                               StoredDiagnostics);
981  }
982
983  Act->Execute();
984
985  // Steal the created target, context, and preprocessor.
986  TheSema.reset(Clang->takeSema());
987  Consumer.reset(Clang->takeASTConsumer());
988  Ctx = &Clang->getASTContext();
989  PP = &Clang->getPreprocessor();
990  Clang->setSourceManager(0);
991  Clang->setFileManager(0);
992  Target = &Clang->getTarget();
993
994  Act->EndSourceFile();
995
996  return false;
997
998error:
999  // Remove the overridden buffer we used for the preamble.
1000  if (OverrideMainBuffer) {
1001    delete OverrideMainBuffer;
1002    SavedMainFileBuffer = 0;
1003  }
1004
1005  StoredDiagnostics.clear();
1006  return true;
1007}
1008
1009/// \brief Simple function to retrieve a path for a preamble precompiled header.
1010static std::string GetPreamblePCHPath() {
1011  // FIXME: This is lame; sys::Path should provide this function (in particular,
1012  // it should know how to find the temporary files dir).
1013  // FIXME: This is really lame. I copied this code from the Driver!
1014  // FIXME: This is a hack so that we can override the preamble file during
1015  // crash-recovery testing, which is the only case where the preamble files
1016  // are not necessarily cleaned up.
1017  const char *TmpFile = ::getenv("CINDEXTEST_PREAMBLE_FILE");
1018  if (TmpFile)
1019    return TmpFile;
1020
1021  std::string Error;
1022  const char *TmpDir = ::getenv("TMPDIR");
1023  if (!TmpDir)
1024    TmpDir = ::getenv("TEMP");
1025  if (!TmpDir)
1026    TmpDir = ::getenv("TMP");
1027#ifdef LLVM_ON_WIN32
1028  if (!TmpDir)
1029    TmpDir = ::getenv("USERPROFILE");
1030#endif
1031  if (!TmpDir)
1032    TmpDir = "/tmp";
1033  llvm::sys::Path P(TmpDir);
1034  P.createDirectoryOnDisk(true);
1035  P.appendComponent("preamble");
1036  P.appendSuffix("pch");
1037  if (P.makeUnique(/*reuse_current=*/false, /*ErrMsg*/0))
1038    return std::string();
1039
1040  return P.str();
1041}
1042
1043/// \brief Compute the preamble for the main file, providing the source buffer
1044/// that corresponds to the main file along with a pair (bytes, start-of-line)
1045/// that describes the preamble.
1046std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> >
1047ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
1048                         unsigned MaxLines, bool &CreatedBuffer) {
1049  FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
1050  PreprocessorOptions &PreprocessorOpts = Invocation.getPreprocessorOpts();
1051  CreatedBuffer = false;
1052
1053  // Try to determine if the main file has been remapped, either from the
1054  // command line (to another file) or directly through the compiler invocation
1055  // (to a memory buffer).
1056  llvm::MemoryBuffer *Buffer = 0;
1057  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
1058  if (const llvm::sys::FileStatus *MainFileStatus = MainFilePath.getFileStatus()) {
1059    // Check whether there is a file-file remapping of the main file
1060    for (PreprocessorOptions::remapped_file_iterator
1061          M = PreprocessorOpts.remapped_file_begin(),
1062          E = PreprocessorOpts.remapped_file_end();
1063         M != E;
1064         ++M) {
1065      llvm::sys::PathWithStatus MPath(M->first);
1066      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
1067        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
1068          // We found a remapping. Try to load the resulting, remapped source.
1069          if (CreatedBuffer) {
1070            delete Buffer;
1071            CreatedBuffer = false;
1072          }
1073
1074          Buffer = getBufferForFile(M->second);
1075          if (!Buffer)
1076            return std::make_pair((llvm::MemoryBuffer*)0,
1077                                  std::make_pair(0, true));
1078          CreatedBuffer = true;
1079        }
1080      }
1081    }
1082
1083    // Check whether there is a file-buffer remapping. It supercedes the
1084    // file-file remapping.
1085    for (PreprocessorOptions::remapped_file_buffer_iterator
1086           M = PreprocessorOpts.remapped_file_buffer_begin(),
1087           E = PreprocessorOpts.remapped_file_buffer_end();
1088         M != E;
1089         ++M) {
1090      llvm::sys::PathWithStatus MPath(M->first);
1091      if (const llvm::sys::FileStatus *MStatus = MPath.getFileStatus()) {
1092        if (MainFileStatus->uniqueID == MStatus->uniqueID) {
1093          // We found a remapping.
1094          if (CreatedBuffer) {
1095            delete Buffer;
1096            CreatedBuffer = false;
1097          }
1098
1099          Buffer = const_cast<llvm::MemoryBuffer *>(M->second);
1100        }
1101      }
1102    }
1103  }
1104
1105  // If the main source file was not remapped, load it now.
1106  if (!Buffer) {
1107    Buffer = getBufferForFile(FrontendOpts.Inputs[0].second);
1108    if (!Buffer)
1109      return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));
1110
1111    CreatedBuffer = true;
1112  }
1113
1114  return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer,
1115                                                       Invocation.getLangOpts(),
1116                                                       MaxLines));
1117}
1118
1119static llvm::MemoryBuffer *CreatePaddedMainFileBuffer(llvm::MemoryBuffer *Old,
1120                                                      unsigned NewSize,
1121                                                      StringRef NewName) {
1122  llvm::MemoryBuffer *Result
1123    = llvm::MemoryBuffer::getNewUninitMemBuffer(NewSize, NewName);
1124  memcpy(const_cast<char*>(Result->getBufferStart()),
1125         Old->getBufferStart(), Old->getBufferSize());
1126  memset(const_cast<char*>(Result->getBufferStart()) + Old->getBufferSize(),
1127         ' ', NewSize - Old->getBufferSize() - 1);
1128  const_cast<char*>(Result->getBufferEnd())[-1] = '\n';
1129
1130  return Result;
1131}
1132
1133/// \brief Attempt to build or re-use a precompiled preamble when (re-)parsing
1134/// the source file.
1135///
1136/// This routine will compute the preamble of the main source file. If a
1137/// non-trivial preamble is found, it will precompile that preamble into a
1138/// precompiled header so that the precompiled preamble can be used to reduce
1139/// reparsing time. If a precompiled preamble has already been constructed,
1140/// this routine will determine if it is still valid and, if so, avoid
1141/// rebuilding the precompiled preamble.
1142///
1143/// \param AllowRebuild When true (the default), this routine is
1144/// allowed to rebuild the precompiled preamble if it is found to be
1145/// out-of-date.
1146///
1147/// \param MaxLines When non-zero, the maximum number of lines that
1148/// can occur within the preamble.
1149///
1150/// \returns If the precompiled preamble can be used, returns a newly-allocated
1151/// buffer that should be used in place of the main file when doing so.
1152/// Otherwise, returns a NULL pointer.
1153llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
1154                              const CompilerInvocation &PreambleInvocationIn,
1155                                                           bool AllowRebuild,
1156                                                           unsigned MaxLines) {
1157
1158  llvm::IntrusiveRefCntPtr<CompilerInvocation>
1159    PreambleInvocation(new CompilerInvocation(PreambleInvocationIn));
1160  FrontendOptions &FrontendOpts = PreambleInvocation->getFrontendOpts();
1161  PreprocessorOptions &PreprocessorOpts
1162    = PreambleInvocation->getPreprocessorOpts();
1163
1164  bool CreatedPreambleBuffer = false;
1165  std::pair<llvm::MemoryBuffer *, std::pair<unsigned, bool> > NewPreamble
1166    = ComputePreamble(*PreambleInvocation, MaxLines, CreatedPreambleBuffer);
1167
1168  // If ComputePreamble() Take ownership of the preamble buffer.
1169  llvm::OwningPtr<llvm::MemoryBuffer> OwnedPreambleBuffer;
1170  if (CreatedPreambleBuffer)
1171    OwnedPreambleBuffer.reset(NewPreamble.first);
1172
1173  if (!NewPreamble.second.first) {
1174    // We couldn't find a preamble in the main source. Clear out the current
1175    // preamble, if we have one. It's obviously no good any more.
1176    Preamble.clear();
1177    if (!PreambleFile.empty()) {
1178      llvm::sys::Path(PreambleFile).eraseFromDisk();
1179      PreambleFile.clear();
1180    }
1181
1182    // The next time we actually see a preamble, precompile it.
1183    PreambleRebuildCounter = 1;
1184    return 0;
1185  }
1186
1187  if (!Preamble.empty()) {
1188    // We've previously computed a preamble. Check whether we have the same
1189    // preamble now that we did before, and that there's enough space in
1190    // the main-file buffer within the precompiled preamble to fit the
1191    // new main file.
1192    if (Preamble.size() == NewPreamble.second.first &&
1193        PreambleEndsAtStartOfLine == NewPreamble.second.second &&
1194        NewPreamble.first->getBufferSize() < PreambleReservedSize-2 &&
1195        memcmp(Preamble.getBufferStart(), NewPreamble.first->getBufferStart(),
1196               NewPreamble.second.first) == 0) {
1197      // The preamble has not changed. We may be able to re-use the precompiled
1198      // preamble.
1199
1200      // Check that none of the files used by the preamble have changed.
1201      bool AnyFileChanged = false;
1202
1203      // First, make a record of those files that have been overridden via
1204      // remapping or unsaved_files.
1205      llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
1206      for (PreprocessorOptions::remapped_file_iterator
1207                R = PreprocessorOpts.remapped_file_begin(),
1208             REnd = PreprocessorOpts.remapped_file_end();
1209           !AnyFileChanged && R != REnd;
1210           ++R) {
1211        struct stat StatBuf;
1212        if (FileMgr->getNoncachedStatValue(R->second, StatBuf)) {
1213          // If we can't stat the file we're remapping to, assume that something
1214          // horrible happened.
1215          AnyFileChanged = true;
1216          break;
1217        }
1218
1219        OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
1220                                                   StatBuf.st_mtime);
1221      }
1222      for (PreprocessorOptions::remapped_file_buffer_iterator
1223                R = PreprocessorOpts.remapped_file_buffer_begin(),
1224             REnd = PreprocessorOpts.remapped_file_buffer_end();
1225           !AnyFileChanged && R != REnd;
1226           ++R) {
1227        // FIXME: Should we actually compare the contents of file->buffer
1228        // remappings?
1229        OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
1230                                                   0);
1231      }
1232
1233      // Check whether anything has changed.
1234      for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
1235             F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
1236           !AnyFileChanged && F != FEnd;
1237           ++F) {
1238        llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
1239          = OverriddenFiles.find(F->first());
1240        if (Overridden != OverriddenFiles.end()) {
1241          // This file was remapped; check whether the newly-mapped file
1242          // matches up with the previous mapping.
1243          if (Overridden->second != F->second)
1244            AnyFileChanged = true;
1245          continue;
1246        }
1247
1248        // The file was not remapped; check whether it has changed on disk.
1249        struct stat StatBuf;
1250        if (FileMgr->getNoncachedStatValue(F->first(), StatBuf)) {
1251          // If we can't stat the file, assume that something horrible happened.
1252          AnyFileChanged = true;
1253        } else if (StatBuf.st_size != F->second.first ||
1254                   StatBuf.st_mtime != F->second.second)
1255          AnyFileChanged = true;
1256      }
1257
1258      if (!AnyFileChanged) {
1259        // Okay! We can re-use the precompiled preamble.
1260
1261        // Set the state of the diagnostic object to mimic its state
1262        // after parsing the preamble.
1263        // FIXME: This won't catch any #pragma push warning changes that
1264        // have occurred in the preamble.
1265        getDiagnostics().Reset();
1266        ProcessWarningOptions(getDiagnostics(),
1267                              PreambleInvocation->getDiagnosticOpts());
1268        getDiagnostics().setNumWarnings(NumWarningsInPreamble);
1269
1270        // Create a version of the main file buffer that is padded to
1271        // buffer size we reserved when creating the preamble.
1272        return CreatePaddedMainFileBuffer(NewPreamble.first,
1273                                          PreambleReservedSize,
1274                                          FrontendOpts.Inputs[0].second);
1275      }
1276    }
1277
1278    // If we aren't allowed to rebuild the precompiled preamble, just
1279    // return now.
1280    if (!AllowRebuild)
1281      return 0;
1282
1283    // We can't reuse the previously-computed preamble. Build a new one.
1284    Preamble.clear();
1285    PreambleDiagnostics.clear();
1286    llvm::sys::Path(PreambleFile).eraseFromDisk();
1287    PreambleRebuildCounter = 1;
1288  } else if (!AllowRebuild) {
1289    // We aren't allowed to rebuild the precompiled preamble; just
1290    // return now.
1291    return 0;
1292  }
1293
1294  // If the preamble rebuild counter > 1, it's because we previously
1295  // failed to build a preamble and we're not yet ready to try
1296  // again. Decrement the counter and return a failure.
1297  if (PreambleRebuildCounter > 1) {
1298    --PreambleRebuildCounter;
1299    return 0;
1300  }
1301
1302  // Create a temporary file for the precompiled preamble. In rare
1303  // circumstances, this can fail.
1304  std::string PreamblePCHPath = GetPreamblePCHPath();
1305  if (PreamblePCHPath.empty()) {
1306    // Try again next time.
1307    PreambleRebuildCounter = 1;
1308    return 0;
1309  }
1310
1311  // We did not previously compute a preamble, or it can't be reused anyway.
1312  SimpleTimer PreambleTimer(WantTiming);
1313  PreambleTimer.setOutput("Precompiling preamble");
1314
1315  // Create a new buffer that stores the preamble. The buffer also contains
1316  // extra space for the original contents of the file (which will be present
1317  // when we actually parse the file) along with more room in case the file
1318  // grows.
1319  PreambleReservedSize = NewPreamble.first->getBufferSize();
1320  if (PreambleReservedSize < 4096)
1321    PreambleReservedSize = 8191;
1322  else
1323    PreambleReservedSize *= 2;
1324
1325  // Save the preamble text for later; we'll need to compare against it for
1326  // subsequent reparses.
1327  StringRef MainFilename = PreambleInvocation->getFrontendOpts().Inputs[0].second;
1328  Preamble.assign(FileMgr->getFile(MainFilename),
1329                  NewPreamble.first->getBufferStart(),
1330                  NewPreamble.first->getBufferStart()
1331                                                  + NewPreamble.second.first);
1332  PreambleEndsAtStartOfLine = NewPreamble.second.second;
1333
1334  delete PreambleBuffer;
1335  PreambleBuffer
1336    = llvm::MemoryBuffer::getNewUninitMemBuffer(PreambleReservedSize,
1337                                                FrontendOpts.Inputs[0].second);
1338  memcpy(const_cast<char*>(PreambleBuffer->getBufferStart()),
1339         NewPreamble.first->getBufferStart(), Preamble.size());
1340  memset(const_cast<char*>(PreambleBuffer->getBufferStart()) + Preamble.size(),
1341         ' ', PreambleReservedSize - Preamble.size() - 1);
1342  const_cast<char*>(PreambleBuffer->getBufferEnd())[-1] = '\n';
1343
1344  // Remap the main source file to the preamble buffer.
1345  llvm::sys::PathWithStatus MainFilePath(FrontendOpts.Inputs[0].second);
1346  PreprocessorOpts.addRemappedFile(MainFilePath.str(), PreambleBuffer);
1347
1348  // Tell the compiler invocation to generate a temporary precompiled header.
1349  FrontendOpts.ProgramAction = frontend::GeneratePCH;
1350  // FIXME: Generate the precompiled header into memory?
1351  FrontendOpts.OutputFile = PreamblePCHPath;
1352  PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
1353  PreprocessorOpts.PrecompiledPreambleBytes.second = false;
1354
1355  // Create the compiler instance to use for building the precompiled preamble.
1356  llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
1357
1358  // Recover resources if we crash before exiting this method.
1359  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1360    CICleanup(Clang.get());
1361
1362  Clang->setInvocation(&*PreambleInvocation);
1363  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
1364
1365  // Set up diagnostics, capturing all of the diagnostics produced.
1366  Clang->setDiagnostics(&getDiagnostics());
1367
1368  // Create the target instance.
1369  Clang->getTargetOpts().Features = TargetFeatures;
1370  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
1371                                               Clang->getTargetOpts()));
1372  if (!Clang->hasTarget()) {
1373    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1374    Preamble.clear();
1375    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1376    PreprocessorOpts.eraseRemappedFile(
1377                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1378    return 0;
1379  }
1380
1381  // Inform the target of the language options.
1382  //
1383  // FIXME: We shouldn't need to do this, the target should be immutable once
1384  // created. This complexity should be lifted elsewhere.
1385  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
1386
1387  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1388         "Invocation must have exactly one source file!");
1389  assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
1390         "FIXME: AST inputs not yet supported here!");
1391  assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1392         "IR inputs not support here!");
1393
1394  // Clear out old caches and data.
1395  getDiagnostics().Reset();
1396  ProcessWarningOptions(getDiagnostics(), Clang->getDiagnosticOpts());
1397  StoredDiagnostics.erase(
1398                    StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
1399                          StoredDiagnostics.end());
1400  TopLevelDecls.clear();
1401  TopLevelDeclsInPreamble.clear();
1402
1403  // Create a file manager object to provide access to and cache the filesystem.
1404  Clang->setFileManager(new FileManager(Clang->getFileSystemOpts()));
1405
1406  // Create the source manager.
1407  Clang->setSourceManager(new SourceManager(getDiagnostics(),
1408                                            Clang->getFileManager()));
1409
1410  llvm::OwningPtr<PrecompilePreambleAction> Act;
1411  Act.reset(new PrecompilePreambleAction(*this));
1412  if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0].second,
1413                            Clang->getFrontendOpts().Inputs[0].first)) {
1414    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1415    Preamble.clear();
1416    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1417    PreprocessorOpts.eraseRemappedFile(
1418                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1419    return 0;
1420  }
1421
1422  Act->Execute();
1423  Act->EndSourceFile();
1424
1425  if (Diagnostics->hasErrorOccurred()) {
1426    // There were errors parsing the preamble, so no precompiled header was
1427    // generated. Forget that we even tried.
1428    // FIXME: Should we leave a note for ourselves to try again?
1429    llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
1430    Preamble.clear();
1431    TopLevelDeclsInPreamble.clear();
1432    PreambleRebuildCounter = DefaultPreambleRebuildInterval;
1433    PreprocessorOpts.eraseRemappedFile(
1434                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1435    return 0;
1436  }
1437
1438  // Transfer any diagnostics generated when parsing the preamble into the set
1439  // of preamble diagnostics.
1440  PreambleDiagnostics.clear();
1441  PreambleDiagnostics.insert(PreambleDiagnostics.end(),
1442                   StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
1443                             StoredDiagnostics.end());
1444  StoredDiagnostics.erase(
1445                    StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
1446                          StoredDiagnostics.end());
1447
1448  // Keep track of the preamble we precompiled.
1449  PreambleFile = FrontendOpts.OutputFile;
1450  NumWarningsInPreamble = getDiagnostics().getNumWarnings();
1451
1452  // Keep track of all of the files that the source manager knows about,
1453  // so we can verify whether they have changed or not.
1454  FilesInPreamble.clear();
1455  SourceManager &SourceMgr = Clang->getSourceManager();
1456  const llvm::MemoryBuffer *MainFileBuffer
1457    = SourceMgr.getBuffer(SourceMgr.getMainFileID());
1458  for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
1459                                     FEnd = SourceMgr.fileinfo_end();
1460       F != FEnd;
1461       ++F) {
1462    const FileEntry *File = F->second->OrigEntry;
1463    if (!File || F->second->getRawBuffer() == MainFileBuffer)
1464      continue;
1465
1466    FilesInPreamble[File->getName()]
1467      = std::make_pair(F->second->getSize(), File->getModificationTime());
1468  }
1469
1470  PreambleRebuildCounter = 1;
1471  PreprocessorOpts.eraseRemappedFile(
1472                               PreprocessorOpts.remapped_file_buffer_end() - 1);
1473
1474  // If the hash of top-level entities differs from the hash of the top-level
1475  // entities the last time we rebuilt the preamble, clear out the completion
1476  // cache.
1477  if (CurrentTopLevelHashValue != PreambleTopLevelHashValue) {
1478    CompletionCacheTopLevelHashValue = 0;
1479    PreambleTopLevelHashValue = CurrentTopLevelHashValue;
1480  }
1481
1482  return CreatePaddedMainFileBuffer(NewPreamble.first,
1483                                    PreambleReservedSize,
1484                                    FrontendOpts.Inputs[0].second);
1485}
1486
1487void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
1488  std::vector<Decl *> Resolved;
1489  Resolved.reserve(TopLevelDeclsInPreamble.size());
1490  ExternalASTSource &Source = *getASTContext().getExternalSource();
1491  for (unsigned I = 0, N = TopLevelDeclsInPreamble.size(); I != N; ++I) {
1492    // Resolve the declaration ID to an actual declaration, possibly
1493    // deserializing the declaration in the process.
1494    Decl *D = Source.GetExternalDecl(TopLevelDeclsInPreamble[I]);
1495    if (D)
1496      Resolved.push_back(D);
1497  }
1498  TopLevelDeclsInPreamble.clear();
1499  TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
1500}
1501
1502StringRef ASTUnit::getMainFileName() const {
1503  return Invocation->getFrontendOpts().Inputs[0].second;
1504}
1505
1506ASTUnit *ASTUnit::create(CompilerInvocation *CI,
1507                         llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags) {
1508  llvm::OwningPtr<ASTUnit> AST;
1509  AST.reset(new ASTUnit(false));
1510  ConfigureDiags(Diags, 0, 0, *AST, /*CaptureDiagnostics=*/false);
1511  AST->Diagnostics = Diags;
1512  AST->Invocation = CI;
1513  AST->FileSystemOpts = CI->getFileSystemOpts();
1514  AST->FileMgr = new FileManager(AST->FileSystemOpts);
1515  AST->SourceMgr = new SourceManager(*Diags, *AST->FileMgr);
1516
1517  return AST.take();
1518}
1519
1520ASTUnit *ASTUnit::LoadFromCompilerInvocationAction(CompilerInvocation *CI,
1521                              llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1522                                             ASTFrontendAction *Action) {
1523  assert(CI && "A CompilerInvocation is required");
1524
1525  // Create the AST unit.
1526  llvm::OwningPtr<ASTUnit> AST;
1527  AST.reset(new ASTUnit(false));
1528  ConfigureDiags(Diags, 0, 0, *AST, /*CaptureDiagnostics*/false);
1529  AST->Diagnostics = Diags;
1530  AST->OnlyLocalDecls = false;
1531  AST->CaptureDiagnostics = false;
1532  AST->TUKind = Action ? Action->getTranslationUnitKind() : TU_Complete;
1533  AST->ShouldCacheCodeCompletionResults = false;
1534  AST->Invocation = CI;
1535
1536  // Recover resources if we crash before exiting this method.
1537  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1538    ASTUnitCleanup(AST.get());
1539  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
1540    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
1541    DiagCleanup(Diags.getPtr());
1542
1543  // We'll manage file buffers ourselves.
1544  CI->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1545  CI->getFrontendOpts().DisableFree = false;
1546  ProcessWarningOptions(AST->getDiagnostics(), CI->getDiagnosticOpts());
1547
1548  // Save the target features.
1549  AST->TargetFeatures = CI->getTargetOpts().Features;
1550
1551  // Create the compiler instance to use for building the AST.
1552  llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
1553
1554  // Recover resources if we crash before exiting this method.
1555  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
1556    CICleanup(Clang.get());
1557
1558  Clang->setInvocation(CI);
1559  AST->OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
1560
1561  // Set up diagnostics, capturing any diagnostics that would
1562  // otherwise be dropped.
1563  Clang->setDiagnostics(&AST->getDiagnostics());
1564
1565  // Create the target instance.
1566  Clang->getTargetOpts().Features = AST->TargetFeatures;
1567  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
1568                   Clang->getTargetOpts()));
1569  if (!Clang->hasTarget())
1570    return 0;
1571
1572  // Inform the target of the language options.
1573  //
1574  // FIXME: We shouldn't need to do this, the target should be immutable once
1575  // created. This complexity should be lifted elsewhere.
1576  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
1577
1578  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
1579         "Invocation must have exactly one source file!");
1580  assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
1581         "FIXME: AST inputs not yet supported here!");
1582  assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
1583         "IR inputs not supported here!");
1584
1585  // Configure the various subsystems.
1586  AST->FileSystemOpts = Clang->getFileSystemOpts();
1587  AST->FileMgr = new FileManager(AST->FileSystemOpts);
1588  AST->SourceMgr = new SourceManager(AST->getDiagnostics(), *AST->FileMgr);
1589  AST->TheSema.reset();
1590  AST->Ctx = 0;
1591  AST->PP = 0;
1592
1593  // Create a file manager object to provide access to and cache the filesystem.
1594  Clang->setFileManager(&AST->getFileManager());
1595
1596  // Create the source manager.
1597  Clang->setSourceManager(&AST->getSourceManager());
1598
1599  ASTFrontendAction *Act = Action;
1600
1601  llvm::OwningPtr<TopLevelDeclTrackerAction> TrackerAct;
1602  if (!Act) {
1603    TrackerAct.reset(new TopLevelDeclTrackerAction(*AST));
1604    Act = TrackerAct.get();
1605  }
1606
1607  // Recover resources if we crash before exiting this method.
1608  llvm::CrashRecoveryContextCleanupRegistrar<TopLevelDeclTrackerAction>
1609    ActCleanup(TrackerAct.get());
1610
1611  if (!Act->BeginSourceFile(*Clang.get(),
1612                            Clang->getFrontendOpts().Inputs[0].second,
1613                            Clang->getFrontendOpts().Inputs[0].first))
1614    return 0;
1615
1616  Act->Execute();
1617
1618  // Steal the created target, context, and preprocessor.
1619  AST->TheSema.reset(Clang->takeSema());
1620  AST->Consumer.reset(Clang->takeASTConsumer());
1621  AST->Ctx = &Clang->getASTContext();
1622  AST->PP = &Clang->getPreprocessor();
1623  Clang->setSourceManager(0);
1624  Clang->setFileManager(0);
1625  AST->Target = &Clang->getTarget();
1626
1627  Act->EndSourceFile();
1628
1629  return AST.take();
1630}
1631
1632bool ASTUnit::LoadFromCompilerInvocation(bool PrecompilePreamble) {
1633  if (!Invocation)
1634    return true;
1635
1636  // We'll manage file buffers ourselves.
1637  Invocation->getPreprocessorOpts().RetainRemappedFileBuffers = true;
1638  Invocation->getFrontendOpts().DisableFree = false;
1639  ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
1640
1641  // Save the target features.
1642  TargetFeatures = Invocation->getTargetOpts().Features;
1643
1644  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1645  if (PrecompilePreamble) {
1646    PreambleRebuildCounter = 2;
1647    OverrideMainBuffer
1648      = getMainBufferWithPrecompiledPreamble(*Invocation);
1649  }
1650
1651  SimpleTimer ParsingTimer(WantTiming);
1652  ParsingTimer.setOutput("Parsing " + getMainFileName());
1653
1654  // Recover resources if we crash before exiting this method.
1655  llvm::CrashRecoveryContextCleanupRegistrar<llvm::MemoryBuffer>
1656    MemBufferCleanup(OverrideMainBuffer);
1657
1658  return Parse(OverrideMainBuffer);
1659}
1660
1661ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
1662                              llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1663                                             bool OnlyLocalDecls,
1664                                             bool CaptureDiagnostics,
1665                                             bool PrecompilePreamble,
1666                                             TranslationUnitKind TUKind,
1667                                             bool CacheCodeCompletionResults,
1668                                             bool NestedMacroExpansions) {
1669  // Create the AST unit.
1670  llvm::OwningPtr<ASTUnit> AST;
1671  AST.reset(new ASTUnit(false));
1672  ConfigureDiags(Diags, 0, 0, *AST, CaptureDiagnostics);
1673  AST->Diagnostics = Diags;
1674  AST->OnlyLocalDecls = OnlyLocalDecls;
1675  AST->CaptureDiagnostics = CaptureDiagnostics;
1676  AST->TUKind = TUKind;
1677  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1678  AST->Invocation = CI;
1679  AST->NestedMacroExpansions = NestedMacroExpansions;
1680
1681  // Recover resources if we crash before exiting this method.
1682  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1683    ASTUnitCleanup(AST.get());
1684  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
1685    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
1686    DiagCleanup(Diags.getPtr());
1687
1688  return AST->LoadFromCompilerInvocation(PrecompilePreamble)? 0 : AST.take();
1689}
1690
1691ASTUnit *ASTUnit::LoadFromCommandLine(const char **ArgBegin,
1692                                      const char **ArgEnd,
1693                                    llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
1694                                      StringRef ResourceFilesPath,
1695                                      bool OnlyLocalDecls,
1696                                      bool CaptureDiagnostics,
1697                                      RemappedFile *RemappedFiles,
1698                                      unsigned NumRemappedFiles,
1699                                      bool RemappedFilesKeepOriginalName,
1700                                      bool PrecompilePreamble,
1701                                      TranslationUnitKind TUKind,
1702                                      bool CacheCodeCompletionResults,
1703                                      bool NestedMacroExpansions) {
1704  if (!Diags.getPtr()) {
1705    // No diagnostics engine was provided, so create our own diagnostics object
1706    // with the default options.
1707    DiagnosticOptions DiagOpts;
1708    Diags = CompilerInstance::createDiagnostics(DiagOpts, ArgEnd - ArgBegin,
1709                                                ArgBegin);
1710  }
1711
1712  SmallVector<StoredDiagnostic, 4> StoredDiagnostics;
1713
1714  llvm::IntrusiveRefCntPtr<CompilerInvocation> CI;
1715
1716  {
1717
1718    CaptureDroppedDiagnostics Capture(CaptureDiagnostics, *Diags,
1719                                      StoredDiagnostics);
1720
1721    CI = clang::createInvocationFromCommandLine(
1722                                           llvm::makeArrayRef(ArgBegin, ArgEnd),
1723                                           Diags);
1724    if (!CI)
1725      return 0;
1726  }
1727
1728  // Override any files that need remapping
1729  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
1730    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
1731    if (const llvm::MemoryBuffer *
1732            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
1733      CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, memBuf);
1734    } else {
1735      const char *fname = fileOrBuf.get<const char *>();
1736      CI->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first, fname);
1737    }
1738  }
1739  CI->getPreprocessorOpts().RemappedFilesKeepOriginalName =
1740                                                  RemappedFilesKeepOriginalName;
1741
1742  // Override the resources path.
1743  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
1744
1745  // Create the AST unit.
1746  llvm::OwningPtr<ASTUnit> AST;
1747  AST.reset(new ASTUnit(false));
1748  ConfigureDiags(Diags, ArgBegin, ArgEnd, *AST, CaptureDiagnostics);
1749  AST->Diagnostics = Diags;
1750
1751  AST->FileSystemOpts = CI->getFileSystemOpts();
1752  AST->FileMgr = new FileManager(AST->FileSystemOpts);
1753  AST->OnlyLocalDecls = OnlyLocalDecls;
1754  AST->CaptureDiagnostics = CaptureDiagnostics;
1755  AST->TUKind = TUKind;
1756  AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
1757  AST->NumStoredDiagnosticsFromDriver = StoredDiagnostics.size();
1758  AST->StoredDiagnostics.swap(StoredDiagnostics);
1759  AST->Invocation = CI;
1760  AST->NestedMacroExpansions = NestedMacroExpansions;
1761
1762  // Recover resources if we crash before exiting this method.
1763  llvm::CrashRecoveryContextCleanupRegistrar<ASTUnit>
1764    ASTUnitCleanup(AST.get());
1765  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInvocation,
1766    llvm::CrashRecoveryContextReleaseRefCleanup<CompilerInvocation> >
1767    CICleanup(CI.getPtr());
1768  llvm::CrashRecoveryContextCleanupRegistrar<DiagnosticsEngine,
1769    llvm::CrashRecoveryContextReleaseRefCleanup<DiagnosticsEngine> >
1770    DiagCleanup(Diags.getPtr());
1771
1772  return AST->LoadFromCompilerInvocation(PrecompilePreamble) ? 0 : AST.take();
1773}
1774
1775bool ASTUnit::Reparse(RemappedFile *RemappedFiles, unsigned NumRemappedFiles) {
1776  if (!Invocation)
1777    return true;
1778
1779  SimpleTimer ParsingTimer(WantTiming);
1780  ParsingTimer.setOutput("Reparsing " + getMainFileName());
1781
1782  // Remap files.
1783  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
1784  PPOpts.DisableStatCache = true;
1785  for (PreprocessorOptions::remapped_file_buffer_iterator
1786         R = PPOpts.remapped_file_buffer_begin(),
1787         REnd = PPOpts.remapped_file_buffer_end();
1788       R != REnd;
1789       ++R) {
1790    delete R->second;
1791  }
1792  Invocation->getPreprocessorOpts().clearRemappedFiles();
1793  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
1794    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
1795    if (const llvm::MemoryBuffer *
1796            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
1797      Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1798                                                        memBuf);
1799    } else {
1800      const char *fname = fileOrBuf.get<const char *>();
1801      Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
1802                                                        fname);
1803    }
1804  }
1805
1806  // If we have a preamble file lying around, or if we might try to
1807  // build a precompiled preamble, do so now.
1808  llvm::MemoryBuffer *OverrideMainBuffer = 0;
1809  if (!PreambleFile.empty() || PreambleRebuildCounter > 0)
1810    OverrideMainBuffer = getMainBufferWithPrecompiledPreamble(*Invocation);
1811
1812  // Clear out the diagnostics state.
1813  if (!OverrideMainBuffer) {
1814    getDiagnostics().Reset();
1815    ProcessWarningOptions(getDiagnostics(), Invocation->getDiagnosticOpts());
1816  }
1817
1818  // Parse the sources
1819  bool Result = Parse(OverrideMainBuffer);
1820
1821  // If we're caching global code-completion results, and the top-level
1822  // declarations have changed, clear out the code-completion cache.
1823  if (!Result && ShouldCacheCodeCompletionResults &&
1824      CurrentTopLevelHashValue != CompletionCacheTopLevelHashValue)
1825    CacheCodeCompletionResults();
1826
1827  // We now need to clear out the completion allocator for
1828  // clang_getCursorCompletionString; it'll be recreated if necessary.
1829  CursorCompletionAllocator = 0;
1830
1831  return Result;
1832}
1833
1834//----------------------------------------------------------------------------//
1835// Code completion
1836//----------------------------------------------------------------------------//
1837
1838namespace {
1839  /// \brief Code completion consumer that combines the cached code-completion
1840  /// results from an ASTUnit with the code-completion results provided to it,
1841  /// then passes the result on to
1842  class AugmentedCodeCompleteConsumer : public CodeCompleteConsumer {
1843    unsigned long long NormalContexts;
1844    ASTUnit &AST;
1845    CodeCompleteConsumer &Next;
1846
1847  public:
1848    AugmentedCodeCompleteConsumer(ASTUnit &AST, CodeCompleteConsumer &Next,
1849                                  bool IncludeMacros, bool IncludeCodePatterns,
1850                                  bool IncludeGlobals)
1851      : CodeCompleteConsumer(IncludeMacros, IncludeCodePatterns, IncludeGlobals,
1852                             Next.isOutputBinary()), AST(AST), Next(Next)
1853    {
1854      // Compute the set of contexts in which we will look when we don't have
1855      // any information about the specific context.
1856      NormalContexts
1857        = (1LL << (CodeCompletionContext::CCC_TopLevel - 1))
1858        | (1LL << (CodeCompletionContext::CCC_ObjCInterface - 1))
1859        | (1LL << (CodeCompletionContext::CCC_ObjCImplementation - 1))
1860        | (1LL << (CodeCompletionContext::CCC_ObjCIvarList - 1))
1861        | (1LL << (CodeCompletionContext::CCC_Statement - 1))
1862        | (1LL << (CodeCompletionContext::CCC_Expression - 1))
1863        | (1LL << (CodeCompletionContext::CCC_ObjCMessageReceiver - 1))
1864        | (1LL << (CodeCompletionContext::CCC_DotMemberAccess - 1))
1865        | (1LL << (CodeCompletionContext::CCC_ArrowMemberAccess - 1))
1866        | (1LL << (CodeCompletionContext::CCC_ObjCPropertyAccess - 1))
1867        | (1LL << (CodeCompletionContext::CCC_ObjCProtocolName - 1))
1868        | (1LL << (CodeCompletionContext::CCC_ParenthesizedExpression - 1))
1869        | (1LL << (CodeCompletionContext::CCC_Recovery - 1));
1870
1871      if (AST.getASTContext().getLangOptions().CPlusPlus)
1872        NormalContexts |= (1LL << (CodeCompletionContext::CCC_EnumTag - 1))
1873                   | (1LL << (CodeCompletionContext::CCC_UnionTag - 1))
1874                   | (1LL << (CodeCompletionContext::CCC_ClassOrStructTag - 1));
1875    }
1876
1877    virtual void ProcessCodeCompleteResults(Sema &S,
1878                                            CodeCompletionContext Context,
1879                                            CodeCompletionResult *Results,
1880                                            unsigned NumResults);
1881
1882    virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
1883                                           OverloadCandidate *Candidates,
1884                                           unsigned NumCandidates) {
1885      Next.ProcessOverloadCandidates(S, CurrentArg, Candidates, NumCandidates);
1886    }
1887
1888    virtual CodeCompletionAllocator &getAllocator() {
1889      return Next.getAllocator();
1890    }
1891  };
1892}
1893
1894/// \brief Helper function that computes which global names are hidden by the
1895/// local code-completion results.
1896static void CalculateHiddenNames(const CodeCompletionContext &Context,
1897                                 CodeCompletionResult *Results,
1898                                 unsigned NumResults,
1899                                 ASTContext &Ctx,
1900                          llvm::StringSet<llvm::BumpPtrAllocator> &HiddenNames){
1901  bool OnlyTagNames = false;
1902  switch (Context.getKind()) {
1903  case CodeCompletionContext::CCC_Recovery:
1904  case CodeCompletionContext::CCC_TopLevel:
1905  case CodeCompletionContext::CCC_ObjCInterface:
1906  case CodeCompletionContext::CCC_ObjCImplementation:
1907  case CodeCompletionContext::CCC_ObjCIvarList:
1908  case CodeCompletionContext::CCC_ClassStructUnion:
1909  case CodeCompletionContext::CCC_Statement:
1910  case CodeCompletionContext::CCC_Expression:
1911  case CodeCompletionContext::CCC_ObjCMessageReceiver:
1912  case CodeCompletionContext::CCC_DotMemberAccess:
1913  case CodeCompletionContext::CCC_ArrowMemberAccess:
1914  case CodeCompletionContext::CCC_ObjCPropertyAccess:
1915  case CodeCompletionContext::CCC_Namespace:
1916  case CodeCompletionContext::CCC_Type:
1917  case CodeCompletionContext::CCC_Name:
1918  case CodeCompletionContext::CCC_PotentiallyQualifiedName:
1919  case CodeCompletionContext::CCC_ParenthesizedExpression:
1920  case CodeCompletionContext::CCC_ObjCInterfaceName:
1921    break;
1922
1923  case CodeCompletionContext::CCC_EnumTag:
1924  case CodeCompletionContext::CCC_UnionTag:
1925  case CodeCompletionContext::CCC_ClassOrStructTag:
1926    OnlyTagNames = true;
1927    break;
1928
1929  case CodeCompletionContext::CCC_ObjCProtocolName:
1930  case CodeCompletionContext::CCC_MacroName:
1931  case CodeCompletionContext::CCC_MacroNameUse:
1932  case CodeCompletionContext::CCC_PreprocessorExpression:
1933  case CodeCompletionContext::CCC_PreprocessorDirective:
1934  case CodeCompletionContext::CCC_NaturalLanguage:
1935  case CodeCompletionContext::CCC_SelectorName:
1936  case CodeCompletionContext::CCC_TypeQualifiers:
1937  case CodeCompletionContext::CCC_Other:
1938  case CodeCompletionContext::CCC_OtherWithMacros:
1939  case CodeCompletionContext::CCC_ObjCInstanceMessage:
1940  case CodeCompletionContext::CCC_ObjCClassMessage:
1941  case CodeCompletionContext::CCC_ObjCCategoryName:
1942    // We're looking for nothing, or we're looking for names that cannot
1943    // be hidden.
1944    return;
1945  }
1946
1947  typedef CodeCompletionResult Result;
1948  for (unsigned I = 0; I != NumResults; ++I) {
1949    if (Results[I].Kind != Result::RK_Declaration)
1950      continue;
1951
1952    unsigned IDNS
1953      = Results[I].Declaration->getUnderlyingDecl()->getIdentifierNamespace();
1954
1955    bool Hiding = false;
1956    if (OnlyTagNames)
1957      Hiding = (IDNS & Decl::IDNS_Tag);
1958    else {
1959      unsigned HiddenIDNS = (Decl::IDNS_Type | Decl::IDNS_Member |
1960                             Decl::IDNS_Namespace | Decl::IDNS_Ordinary |
1961                             Decl::IDNS_NonMemberOperator);
1962      if (Ctx.getLangOptions().CPlusPlus)
1963        HiddenIDNS |= Decl::IDNS_Tag;
1964      Hiding = (IDNS & HiddenIDNS);
1965    }
1966
1967    if (!Hiding)
1968      continue;
1969
1970    DeclarationName Name = Results[I].Declaration->getDeclName();
1971    if (IdentifierInfo *Identifier = Name.getAsIdentifierInfo())
1972      HiddenNames.insert(Identifier->getName());
1973    else
1974      HiddenNames.insert(Name.getAsString());
1975  }
1976}
1977
1978
1979void AugmentedCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &S,
1980                                            CodeCompletionContext Context,
1981                                            CodeCompletionResult *Results,
1982                                            unsigned NumResults) {
1983  // Merge the results we were given with the results we cached.
1984  bool AddedResult = false;
1985  unsigned InContexts
1986    = (Context.getKind() == CodeCompletionContext::CCC_Recovery? NormalContexts
1987                                        : (1ULL << (Context.getKind() - 1)));
1988  // Contains the set of names that are hidden by "local" completion results.
1989  llvm::StringSet<llvm::BumpPtrAllocator> HiddenNames;
1990  typedef CodeCompletionResult Result;
1991  SmallVector<Result, 8> AllResults;
1992  for (ASTUnit::cached_completion_iterator
1993            C = AST.cached_completion_begin(),
1994         CEnd = AST.cached_completion_end();
1995       C != CEnd; ++C) {
1996    // If the context we are in matches any of the contexts we are
1997    // interested in, we'll add this result.
1998    if ((C->ShowInContexts & InContexts) == 0)
1999      continue;
2000
2001    // If we haven't added any results previously, do so now.
2002    if (!AddedResult) {
2003      CalculateHiddenNames(Context, Results, NumResults, S.Context,
2004                           HiddenNames);
2005      AllResults.insert(AllResults.end(), Results, Results + NumResults);
2006      AddedResult = true;
2007    }
2008
2009    // Determine whether this global completion result is hidden by a local
2010    // completion result. If so, skip it.
2011    if (C->Kind != CXCursor_MacroDefinition &&
2012        HiddenNames.count(C->Completion->getTypedText()))
2013      continue;
2014
2015    // Adjust priority based on similar type classes.
2016    unsigned Priority = C->Priority;
2017    CXCursorKind CursorKind = C->Kind;
2018    CodeCompletionString *Completion = C->Completion;
2019    if (!Context.getPreferredType().isNull()) {
2020      if (C->Kind == CXCursor_MacroDefinition) {
2021        Priority = getMacroUsagePriority(C->Completion->getTypedText(),
2022                                         S.getLangOptions(),
2023                               Context.getPreferredType()->isAnyPointerType());
2024      } else if (C->Type) {
2025        CanQualType Expected
2026          = S.Context.getCanonicalType(
2027                               Context.getPreferredType().getUnqualifiedType());
2028        SimplifiedTypeClass ExpectedSTC = getSimplifiedTypeClass(Expected);
2029        if (ExpectedSTC == C->TypeClass) {
2030          // We know this type is similar; check for an exact match.
2031          llvm::StringMap<unsigned> &CachedCompletionTypes
2032            = AST.getCachedCompletionTypes();
2033          llvm::StringMap<unsigned>::iterator Pos
2034            = CachedCompletionTypes.find(QualType(Expected).getAsString());
2035          if (Pos != CachedCompletionTypes.end() && Pos->second == C->Type)
2036            Priority /= CCF_ExactTypeMatch;
2037          else
2038            Priority /= CCF_SimilarTypeMatch;
2039        }
2040      }
2041    }
2042
2043    // Adjust the completion string, if required.
2044    if (C->Kind == CXCursor_MacroDefinition &&
2045        Context.getKind() == CodeCompletionContext::CCC_MacroNameUse) {
2046      // Create a new code-completion string that just contains the
2047      // macro name, without its arguments.
2048      CodeCompletionBuilder Builder(getAllocator(), CCP_CodePattern,
2049                                    C->Availability);
2050      Builder.AddTypedTextChunk(C->Completion->getTypedText());
2051      CursorKind = CXCursor_NotImplemented;
2052      Priority = CCP_CodePattern;
2053      Completion = Builder.TakeString();
2054    }
2055
2056    AllResults.push_back(Result(Completion, Priority, CursorKind,
2057                                C->Availability));
2058  }
2059
2060  // If we did not add any cached completion results, just forward the
2061  // results we were given to the next consumer.
2062  if (!AddedResult) {
2063    Next.ProcessCodeCompleteResults(S, Context, Results, NumResults);
2064    return;
2065  }
2066
2067  Next.ProcessCodeCompleteResults(S, Context, AllResults.data(),
2068                                  AllResults.size());
2069}
2070
2071
2072
2073void ASTUnit::CodeComplete(StringRef File, unsigned Line, unsigned Column,
2074                           RemappedFile *RemappedFiles,
2075                           unsigned NumRemappedFiles,
2076                           bool IncludeMacros,
2077                           bool IncludeCodePatterns,
2078                           CodeCompleteConsumer &Consumer,
2079                           DiagnosticsEngine &Diag, LangOptions &LangOpts,
2080                           SourceManager &SourceMgr, FileManager &FileMgr,
2081                   SmallVectorImpl<StoredDiagnostic> &StoredDiagnostics,
2082             SmallVectorImpl<const llvm::MemoryBuffer *> &OwnedBuffers) {
2083  if (!Invocation)
2084    return;
2085
2086  SimpleTimer CompletionTimer(WantTiming);
2087  CompletionTimer.setOutput("Code completion @ " + File + ":" +
2088                            Twine(Line) + ":" + Twine(Column));
2089
2090  llvm::IntrusiveRefCntPtr<CompilerInvocation>
2091    CCInvocation(new CompilerInvocation(*Invocation));
2092
2093  FrontendOptions &FrontendOpts = CCInvocation->getFrontendOpts();
2094  PreprocessorOptions &PreprocessorOpts = CCInvocation->getPreprocessorOpts();
2095
2096  FrontendOpts.ShowMacrosInCodeCompletion
2097    = IncludeMacros && CachedCompletionResults.empty();
2098  FrontendOpts.ShowCodePatternsInCodeCompletion = IncludeCodePatterns;
2099  FrontendOpts.ShowGlobalSymbolsInCodeCompletion
2100    = CachedCompletionResults.empty();
2101  FrontendOpts.CodeCompletionAt.FileName = File;
2102  FrontendOpts.CodeCompletionAt.Line = Line;
2103  FrontendOpts.CodeCompletionAt.Column = Column;
2104
2105  // Set the language options appropriately.
2106  LangOpts = CCInvocation->getLangOpts();
2107
2108  llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
2109
2110  // Recover resources if we crash before exiting this method.
2111  llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
2112    CICleanup(Clang.get());
2113
2114  Clang->setInvocation(&*CCInvocation);
2115  OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
2116
2117  // Set up diagnostics, capturing any diagnostics produced.
2118  Clang->setDiagnostics(&Diag);
2119  ProcessWarningOptions(Diag, CCInvocation->getDiagnosticOpts());
2120  CaptureDroppedDiagnostics Capture(true,
2121                                    Clang->getDiagnostics(),
2122                                    StoredDiagnostics);
2123
2124  // Create the target instance.
2125  Clang->getTargetOpts().Features = TargetFeatures;
2126  Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
2127                                               Clang->getTargetOpts()));
2128  if (!Clang->hasTarget()) {
2129    Clang->setInvocation(0);
2130    return;
2131  }
2132
2133  // Inform the target of the language options.
2134  //
2135  // FIXME: We shouldn't need to do this, the target should be immutable once
2136  // created. This complexity should be lifted elsewhere.
2137  Clang->getTarget().setForcedLangOptions(Clang->getLangOpts());
2138
2139  assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
2140         "Invocation must have exactly one source file!");
2141  assert(Clang->getFrontendOpts().Inputs[0].first != IK_AST &&
2142         "FIXME: AST inputs not yet supported here!");
2143  assert(Clang->getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
2144         "IR inputs not support here!");
2145
2146
2147  // Use the source and file managers that we were given.
2148  Clang->setFileManager(&FileMgr);
2149  Clang->setSourceManager(&SourceMgr);
2150
2151  // Remap files.
2152  PreprocessorOpts.clearRemappedFiles();
2153  PreprocessorOpts.RetainRemappedFileBuffers = true;
2154  for (unsigned I = 0; I != NumRemappedFiles; ++I) {
2155    FilenameOrMemBuf fileOrBuf = RemappedFiles[I].second;
2156    if (const llvm::MemoryBuffer *
2157            memBuf = fileOrBuf.dyn_cast<const llvm::MemoryBuffer *>()) {
2158      PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, memBuf);
2159      OwnedBuffers.push_back(memBuf);
2160    } else {
2161      const char *fname = fileOrBuf.get<const char *>();
2162      PreprocessorOpts.addRemappedFile(RemappedFiles[I].first, fname);
2163    }
2164  }
2165
2166  // Use the code completion consumer we were given, but adding any cached
2167  // code-completion results.
2168  AugmentedCodeCompleteConsumer *AugmentedConsumer
2169    = new AugmentedCodeCompleteConsumer(*this, Consumer,
2170                                        FrontendOpts.ShowMacrosInCodeCompletion,
2171                                FrontendOpts.ShowCodePatternsInCodeCompletion,
2172                                FrontendOpts.ShowGlobalSymbolsInCodeCompletion);
2173  Clang->setCodeCompletionConsumer(AugmentedConsumer);
2174
2175  // If we have a precompiled preamble, try to use it. We only allow
2176  // the use of the precompiled preamble if we're if the completion
2177  // point is within the main file, after the end of the precompiled
2178  // preamble.
2179  llvm::MemoryBuffer *OverrideMainBuffer = 0;
2180  if (!PreambleFile.empty()) {
2181    using llvm::sys::FileStatus;
2182    llvm::sys::PathWithStatus CompleteFilePath(File);
2183    llvm::sys::PathWithStatus MainPath(OriginalSourceFile);
2184    if (const FileStatus *CompleteFileStatus = CompleteFilePath.getFileStatus())
2185      if (const FileStatus *MainStatus = MainPath.getFileStatus())
2186        if (CompleteFileStatus->getUniqueID() == MainStatus->getUniqueID() &&
2187            Line > 1)
2188          OverrideMainBuffer
2189            = getMainBufferWithPrecompiledPreamble(*CCInvocation, false,
2190                                                   Line - 1);
2191  }
2192
2193  // If the main file has been overridden due to the use of a preamble,
2194  // make that override happen and introduce the preamble.
2195  PreprocessorOpts.DisableStatCache = true;
2196  StoredDiagnostics.insert(StoredDiagnostics.end(),
2197                           this->StoredDiagnostics.begin(),
2198             this->StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver);
2199  if (OverrideMainBuffer) {
2200    PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
2201    PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
2202    PreprocessorOpts.PrecompiledPreambleBytes.second
2203                                                    = PreambleEndsAtStartOfLine;
2204    PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
2205    PreprocessorOpts.DisablePCHValidation = true;
2206
2207    OwnedBuffers.push_back(OverrideMainBuffer);
2208  } else {
2209    PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
2210    PreprocessorOpts.PrecompiledPreambleBytes.second = false;
2211  }
2212
2213  // Disable the preprocessing record
2214  PreprocessorOpts.DetailedRecord = false;
2215
2216  llvm::OwningPtr<SyntaxOnlyAction> Act;
2217  Act.reset(new SyntaxOnlyAction);
2218  if (Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0].second,
2219                           Clang->getFrontendOpts().Inputs[0].first)) {
2220    if (OverrideMainBuffer) {
2221      std::string ModName = PreambleFile;
2222      TranslateStoredDiagnostics(Clang->getModuleManager(), ModName,
2223                                 getSourceManager(), PreambleDiagnostics,
2224                                 StoredDiagnostics);
2225    }
2226    Act->Execute();
2227    Act->EndSourceFile();
2228  }
2229}
2230
2231CXSaveError ASTUnit::Save(StringRef File) {
2232  if (getDiagnostics().hasUnrecoverableErrorOccurred())
2233    return CXSaveError_TranslationErrors;
2234
2235  // Write to a temporary file and later rename it to the actual file, to avoid
2236  // possible race conditions.
2237  llvm::SmallString<128> TempPath;
2238  TempPath = File;
2239  TempPath += "-%%%%%%%%";
2240  int fd;
2241  if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
2242                                 /*makeAbsolute=*/false))
2243    return CXSaveError_Unknown;
2244
2245  // FIXME: Can we somehow regenerate the stat cache here, or do we need to
2246  // unconditionally create a stat cache when we parse the file?
2247  llvm::raw_fd_ostream Out(fd, /*shouldClose=*/true);
2248
2249  serialize(Out);
2250  Out.close();
2251  if (Out.has_error())
2252    return CXSaveError_Unknown;
2253
2254  if (llvm::error_code ec = llvm::sys::fs::rename(TempPath.str(), File)) {
2255    bool exists;
2256    llvm::sys::fs::remove(TempPath.str(), exists);
2257    return CXSaveError_Unknown;
2258  }
2259
2260  return CXSaveError_None;
2261}
2262
2263bool ASTUnit::serialize(raw_ostream &OS) {
2264  if (getDiagnostics().hasErrorOccurred())
2265    return true;
2266
2267  std::vector<unsigned char> Buffer;
2268  llvm::BitstreamWriter Stream(Buffer);
2269  ASTWriter Writer(Stream);
2270  // FIXME: Handle modules
2271  Writer.WriteAST(getSema(), 0, std::string(), /*IsModule=*/false, "");
2272
2273  // Write the generated bitstream to "Out".
2274  if (!Buffer.empty())
2275    OS.write((char *)&Buffer.front(), Buffer.size());
2276
2277  return false;
2278}
2279
2280typedef ContinuousRangeMap<unsigned, int, 2> SLocRemap;
2281
2282static void TranslateSLoc(SourceLocation &L, SLocRemap &Remap) {
2283  unsigned Raw = L.getRawEncoding();
2284  const unsigned MacroBit = 1U << 31;
2285  L = SourceLocation::getFromRawEncoding((Raw & MacroBit) |
2286      ((Raw & ~MacroBit) + Remap.find(Raw & ~MacroBit)->second));
2287}
2288
2289void ASTUnit::TranslateStoredDiagnostics(
2290                          ASTReader *MMan,
2291                          StringRef ModName,
2292                          SourceManager &SrcMgr,
2293                          const SmallVectorImpl<StoredDiagnostic> &Diags,
2294                          SmallVectorImpl<StoredDiagnostic> &Out) {
2295  // The stored diagnostic has the old source manager in it; update
2296  // the locations to refer into the new source manager. We also need to remap
2297  // all the locations to the new view. This includes the diag location, any
2298  // associated source ranges, and the source ranges of associated fix-its.
2299  // FIXME: There should be a cleaner way to do this.
2300
2301  SmallVector<StoredDiagnostic, 4> Result;
2302  Result.reserve(Diags.size());
2303  assert(MMan && "Don't have a module manager");
2304  serialization::Module *Mod = MMan->ModuleMgr.lookup(ModName);
2305  assert(Mod && "Don't have preamble module");
2306  SLocRemap &Remap = Mod->SLocRemap;
2307  for (unsigned I = 0, N = Diags.size(); I != N; ++I) {
2308    // Rebuild the StoredDiagnostic.
2309    const StoredDiagnostic &SD = Diags[I];
2310    SourceLocation L = SD.getLocation();
2311    TranslateSLoc(L, Remap);
2312    FullSourceLoc Loc(L, SrcMgr);
2313
2314    SmallVector<CharSourceRange, 4> Ranges;
2315    Ranges.reserve(SD.range_size());
2316    for (StoredDiagnostic::range_iterator I = SD.range_begin(),
2317                                          E = SD.range_end();
2318         I != E; ++I) {
2319      SourceLocation BL = I->getBegin();
2320      TranslateSLoc(BL, Remap);
2321      SourceLocation EL = I->getEnd();
2322      TranslateSLoc(EL, Remap);
2323      Ranges.push_back(CharSourceRange(SourceRange(BL, EL), I->isTokenRange()));
2324    }
2325
2326    SmallVector<FixItHint, 2> FixIts;
2327    FixIts.reserve(SD.fixit_size());
2328    for (StoredDiagnostic::fixit_iterator I = SD.fixit_begin(),
2329                                          E = SD.fixit_end();
2330         I != E; ++I) {
2331      FixIts.push_back(FixItHint());
2332      FixItHint &FH = FixIts.back();
2333      FH.CodeToInsert = I->CodeToInsert;
2334      SourceLocation BL = I->RemoveRange.getBegin();
2335      TranslateSLoc(BL, Remap);
2336      SourceLocation EL = I->RemoveRange.getEnd();
2337      TranslateSLoc(EL, Remap);
2338      FH.RemoveRange = CharSourceRange(SourceRange(BL, EL),
2339                                       I->RemoveRange.isTokenRange());
2340    }
2341
2342    Result.push_back(StoredDiagnostic(SD.getLevel(), SD.getID(),
2343                                      SD.getMessage(), Loc, Ranges, FixIts));
2344  }
2345  Result.swap(Out);
2346}
2347
2348SourceLocation ASTUnit::getLocation(const FileEntry *File,
2349                                    unsigned Line, unsigned Col) const {
2350  const SourceManager &SM = getSourceManager();
2351  SourceLocation Loc = SM.translateFileLineCol(File, Line, Col);
2352  return SM.getMacroArgExpandedLocation(Loc);
2353}
2354
2355SourceLocation ASTUnit::getLocation(const FileEntry *File,
2356                                    unsigned Offset) const {
2357  const SourceManager &SM = getSourceManager();
2358  SourceLocation FileLoc = SM.translateFileLineCol(File, 1, 1);
2359  return SM.getMacroArgExpandedLocation(FileLoc.getLocWithOffset(Offset));
2360}
2361
2362/// \brief If \arg Loc is a loaded location from the preamble, returns
2363/// the corresponding local location of the main file, otherwise it returns
2364/// \arg Loc.
2365SourceLocation ASTUnit::mapLocationFromPreamble(SourceLocation Loc) {
2366  FileID PreambleID;
2367  if (SourceMgr)
2368    PreambleID = SourceMgr->getPreambleFileID();
2369
2370  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
2371    return Loc;
2372
2373  unsigned Offs;
2374  if (SourceMgr->isInFileID(Loc, PreambleID, &Offs) && Offs < Preamble.size()) {
2375    SourceLocation FileLoc
2376        = SourceMgr->getLocForStartOfFile(SourceMgr->getMainFileID());
2377    return FileLoc.getLocWithOffset(Offs);
2378  }
2379
2380  return Loc;
2381}
2382
2383/// \brief If \arg Loc is a local location of the main file but inside the
2384/// preamble chunk, returns the corresponding loaded location from the
2385/// preamble, otherwise it returns \arg Loc.
2386SourceLocation ASTUnit::mapLocationToPreamble(SourceLocation Loc) {
2387  FileID PreambleID;
2388  if (SourceMgr)
2389    PreambleID = SourceMgr->getPreambleFileID();
2390
2391  if (Loc.isInvalid() || Preamble.empty() || PreambleID.isInvalid())
2392    return Loc;
2393
2394  unsigned Offs;
2395  if (SourceMgr->isInFileID(Loc, SourceMgr->getMainFileID(), &Offs) &&
2396      Offs < Preamble.size()) {
2397    SourceLocation FileLoc = SourceMgr->getLocForStartOfFile(PreambleID);
2398    return FileLoc.getLocWithOffset(Offs);
2399  }
2400
2401  return Loc;
2402}
2403
2404void ASTUnit::PreambleData::countLines() const {
2405  NumLines = 0;
2406  if (empty())
2407    return;
2408
2409  for (std::vector<char>::const_iterator
2410         I = Buffer.begin(), E = Buffer.end(); I != E; ++I) {
2411    if (*I == '\n')
2412      ++NumLines;
2413  }
2414  if (Buffer.back() != '\n')
2415    ++NumLines;
2416}
2417