1//===--- CompilerInstance.cpp ---------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "clang/Frontend/CompilerInstance.h"
10#include "clang/AST/ASTConsumer.h"
11#include "clang/AST/ASTContext.h"
12#include "clang/AST/Decl.h"
13#include "clang/Basic/CharInfo.h"
14#include "clang/Basic/Diagnostic.h"
15#include "clang/Basic/FileManager.h"
16#include "clang/Basic/LangStandard.h"
17#include "clang/Basic/SourceManager.h"
18#include "clang/Basic/Stack.h"
19#include "clang/Basic/TargetInfo.h"
20#include "clang/Basic/Version.h"
21#include "clang/Config/config.h"
22#include "clang/Frontend/ChainedDiagnosticConsumer.h"
23#include "clang/Frontend/FrontendAction.h"
24#include "clang/Frontend/FrontendActions.h"
25#include "clang/Frontend/FrontendDiagnostic.h"
26#include "clang/Frontend/LogDiagnosticPrinter.h"
27#include "clang/Frontend/SerializedDiagnosticPrinter.h"
28#include "clang/Frontend/TextDiagnosticPrinter.h"
29#include "clang/Frontend/Utils.h"
30#include "clang/Frontend/VerifyDiagnosticConsumer.h"
31#include "clang/Lex/HeaderSearch.h"
32#include "clang/Lex/Preprocessor.h"
33#include "clang/Lex/PreprocessorOptions.h"
34#include "clang/Sema/CodeCompleteConsumer.h"
35#include "clang/Sema/Sema.h"
36#include "clang/Serialization/ASTReader.h"
37#include "clang/Serialization/GlobalModuleIndex.h"
38#include "clang/Serialization/InMemoryModuleCache.h"
39#include "llvm/ADT/Statistic.h"
40#include "llvm/Support/BuryPointer.h"
41#include "llvm/Support/CrashRecoveryContext.h"
42#include "llvm/Support/Errc.h"
43#include "llvm/Support/FileSystem.h"
44#include "llvm/Support/Host.h"
45#include "llvm/Support/LockFileManager.h"
46#include "llvm/Support/MemoryBuffer.h"
47#include "llvm/Support/Path.h"
48#include "llvm/Support/Program.h"
49#include "llvm/Support/Signals.h"
50#include "llvm/Support/TimeProfiler.h"
51#include "llvm/Support/Timer.h"
52#include "llvm/Support/raw_ostream.h"
53#include <time.h>
54#include <utility>
55
56using namespace clang;
57
58CompilerInstance::CompilerInstance(
59    std::shared_ptr<PCHContainerOperations> PCHContainerOps,
60    InMemoryModuleCache *SharedModuleCache)
61    : ModuleLoader(/* BuildingModule = */ SharedModuleCache),
62      Invocation(new CompilerInvocation()),
63      ModuleCache(SharedModuleCache ? SharedModuleCache
64                                    : new InMemoryModuleCache),
65      ThePCHContainerOperations(std::move(PCHContainerOps)) {}
66
67CompilerInstance::~CompilerInstance() {
68  assert(OutputFiles.empty() && "Still output files in flight?");
69}
70
71void CompilerInstance::setInvocation(
72    std::shared_ptr<CompilerInvocation> Value) {
73  Invocation = std::move(Value);
74}
75
76bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
77  return (BuildGlobalModuleIndex ||
78          (TheASTReader && TheASTReader->isGlobalIndexUnavailable() &&
79           getFrontendOpts().GenerateGlobalModuleIndex)) &&
80         !ModuleBuildFailed;
81}
82
83void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
84  Diagnostics = Value;
85}
86
87void CompilerInstance::setVerboseOutputStream(raw_ostream &Value) {
88  OwnedVerboseOutputStream.release();
89  VerboseOutputStream = &Value;
90}
91
92void CompilerInstance::setVerboseOutputStream(std::unique_ptr<raw_ostream> Value) {
93  OwnedVerboseOutputStream.swap(Value);
94  VerboseOutputStream = OwnedVerboseOutputStream.get();
95}
96
97void CompilerInstance::setTarget(TargetInfo *Value) { Target = Value; }
98void CompilerInstance::setAuxTarget(TargetInfo *Value) { AuxTarget = Value; }
99
100llvm::vfs::FileSystem &CompilerInstance::getVirtualFileSystem() const {
101  return getFileManager().getVirtualFileSystem();
102}
103
104void CompilerInstance::setFileManager(FileManager *Value) {
105  FileMgr = Value;
106}
107
108void CompilerInstance::setSourceManager(SourceManager *Value) {
109  SourceMgr = Value;
110}
111
112void CompilerInstance::setPreprocessor(std::shared_ptr<Preprocessor> Value) {
113  PP = std::move(Value);
114}
115
116void CompilerInstance::setASTContext(ASTContext *Value) {
117  Context = Value;
118
119  if (Context && Consumer)
120    getASTConsumer().Initialize(getASTContext());
121}
122
123void CompilerInstance::setSema(Sema *S) {
124  TheSema.reset(S);
125}
126
127void CompilerInstance::setASTConsumer(std::unique_ptr<ASTConsumer> Value) {
128  Consumer = std::move(Value);
129
130  if (Context && Consumer)
131    getASTConsumer().Initialize(getASTContext());
132}
133
134void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
135  CompletionConsumer.reset(Value);
136}
137
138std::unique_ptr<Sema> CompilerInstance::takeSema() {
139  return std::move(TheSema);
140}
141
142IntrusiveRefCntPtr<ASTReader> CompilerInstance::getASTReader() const {
143  return TheASTReader;
144}
145void CompilerInstance::setASTReader(IntrusiveRefCntPtr<ASTReader> Reader) {
146  assert(ModuleCache.get() == &Reader->getModuleManager().getModuleCache() &&
147         "Expected ASTReader to use the same PCM cache");
148  TheASTReader = std::move(Reader);
149}
150
151std::shared_ptr<ModuleDependencyCollector>
152CompilerInstance::getModuleDepCollector() const {
153  return ModuleDepCollector;
154}
155
156void CompilerInstance::setModuleDepCollector(
157    std::shared_ptr<ModuleDependencyCollector> Collector) {
158  ModuleDepCollector = std::move(Collector);
159}
160
161static void collectHeaderMaps(const HeaderSearch &HS,
162                              std::shared_ptr<ModuleDependencyCollector> MDC) {
163  SmallVector<std::string, 4> HeaderMapFileNames;
164  HS.getHeaderMapFileNames(HeaderMapFileNames);
165  for (auto &Name : HeaderMapFileNames)
166    MDC->addFile(Name);
167}
168
169static void collectIncludePCH(CompilerInstance &CI,
170                              std::shared_ptr<ModuleDependencyCollector> MDC) {
171  const PreprocessorOptions &PPOpts = CI.getPreprocessorOpts();
172  if (PPOpts.ImplicitPCHInclude.empty())
173    return;
174
175  StringRef PCHInclude = PPOpts.ImplicitPCHInclude;
176  FileManager &FileMgr = CI.getFileManager();
177  auto PCHDir = FileMgr.getDirectory(PCHInclude);
178  if (!PCHDir) {
179    MDC->addFile(PCHInclude);
180    return;
181  }
182
183  std::error_code EC;
184  SmallString<128> DirNative;
185  llvm::sys::path::native((*PCHDir)->getName(), DirNative);
186  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
187  SimpleASTReaderListener Validator(CI.getPreprocessor());
188  for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC), DirEnd;
189       Dir != DirEnd && !EC; Dir.increment(EC)) {
190    // Check whether this is an AST file. ASTReader::isAcceptableASTFile is not
191    // used here since we're not interested in validating the PCH at this time,
192    // but only to check whether this is a file containing an AST.
193    if (!ASTReader::readASTFileControlBlock(
194            Dir->path(), FileMgr, CI.getPCHContainerReader(),
195            /*FindModuleFileExtensions=*/false, Validator,
196            /*ValidateDiagnosticOptions=*/false))
197      MDC->addFile(Dir->path());
198  }
199}
200
201static void collectVFSEntries(CompilerInstance &CI,
202                              std::shared_ptr<ModuleDependencyCollector> MDC) {
203  if (CI.getHeaderSearchOpts().VFSOverlayFiles.empty())
204    return;
205
206  // Collect all VFS found.
207  SmallVector<llvm::vfs::YAMLVFSEntry, 16> VFSEntries;
208  for (const std::string &VFSFile : CI.getHeaderSearchOpts().VFSOverlayFiles) {
209    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buffer =
210        llvm::MemoryBuffer::getFile(VFSFile);
211    if (!Buffer)
212      return;
213    llvm::vfs::collectVFSFromYAML(std::move(Buffer.get()),
214                                  /*DiagHandler*/ nullptr, VFSFile, VFSEntries);
215  }
216
217  for (auto &E : VFSEntries)
218    MDC->addFile(E.VPath, E.RPath);
219}
220
221// Diagnostics
222static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
223                               const CodeGenOptions *CodeGenOpts,
224                               DiagnosticsEngine &Diags) {
225  std::error_code EC;
226  std::unique_ptr<raw_ostream> StreamOwner;
227  raw_ostream *OS = &llvm::errs();
228  if (DiagOpts->DiagnosticLogFile != "-") {
229    // Create the output stream.
230    auto FileOS = std::make_unique<llvm::raw_fd_ostream>(
231        DiagOpts->DiagnosticLogFile, EC,
232        llvm::sys::fs::OF_Append | llvm::sys::fs::OF_Text);
233    if (EC) {
234      Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
235          << DiagOpts->DiagnosticLogFile << EC.message();
236    } else {
237      FileOS->SetUnbuffered();
238      OS = FileOS.get();
239      StreamOwner = std::move(FileOS);
240    }
241  }
242
243  // Chain in the diagnostic client which will log the diagnostics.
244  auto Logger = std::make_unique<LogDiagnosticPrinter>(*OS, DiagOpts,
245                                                        std::move(StreamOwner));
246  if (CodeGenOpts)
247    Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
248  if (Diags.ownsClient()) {
249    Diags.setClient(
250        new ChainedDiagnosticConsumer(Diags.takeClient(), std::move(Logger)));
251  } else {
252    Diags.setClient(
253        new ChainedDiagnosticConsumer(Diags.getClient(), std::move(Logger)));
254  }
255}
256
257static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
258                                       DiagnosticsEngine &Diags,
259                                       StringRef OutputFile) {
260  auto SerializedConsumer =
261      clang::serialized_diags::create(OutputFile, DiagOpts);
262
263  if (Diags.ownsClient()) {
264    Diags.setClient(new ChainedDiagnosticConsumer(
265        Diags.takeClient(), std::move(SerializedConsumer)));
266  } else {
267    Diags.setClient(new ChainedDiagnosticConsumer(
268        Diags.getClient(), std::move(SerializedConsumer)));
269  }
270}
271
272void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
273                                         bool ShouldOwnClient) {
274  Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
275                                  ShouldOwnClient, &getCodeGenOpts());
276}
277
278IntrusiveRefCntPtr<DiagnosticsEngine>
279CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
280                                    DiagnosticConsumer *Client,
281                                    bool ShouldOwnClient,
282                                    const CodeGenOptions *CodeGenOpts) {
283  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
284  IntrusiveRefCntPtr<DiagnosticsEngine>
285      Diags(new DiagnosticsEngine(DiagID, Opts));
286
287  // Create the diagnostic client for reporting errors or for
288  // implementing -verify.
289  if (Client) {
290    Diags->setClient(Client, ShouldOwnClient);
291  } else
292    Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
293
294  // Chain in -verify checker, if requested.
295  if (Opts->VerifyDiagnostics)
296    Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
297
298  // Chain in -diagnostic-log-file dumper, if requested.
299  if (!Opts->DiagnosticLogFile.empty())
300    SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
301
302  if (!Opts->DiagnosticSerializationFile.empty())
303    SetupSerializedDiagnostics(Opts, *Diags,
304                               Opts->DiagnosticSerializationFile);
305
306  // Configure our handling of diagnostics.
307  ProcessWarningOptions(*Diags, *Opts);
308
309  return Diags;
310}
311
312// File Manager
313
314FileManager *CompilerInstance::createFileManager(
315    IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
316  if (!VFS)
317    VFS = FileMgr ? &FileMgr->getVirtualFileSystem()
318                  : createVFSFromCompilerInvocation(getInvocation(),
319                                                    getDiagnostics());
320  assert(VFS && "FileManager has no VFS?");
321  FileMgr = new FileManager(getFileSystemOpts(), std::move(VFS));
322  return FileMgr.get();
323}
324
325// Source Manager
326
327void CompilerInstance::createSourceManager(FileManager &FileMgr) {
328  SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
329}
330
331// Initialize the remapping of files to alternative contents, e.g.,
332// those specified through other files.
333static void InitializeFileRemapping(DiagnosticsEngine &Diags,
334                                    SourceManager &SourceMgr,
335                                    FileManager &FileMgr,
336                                    const PreprocessorOptions &InitOpts) {
337  // Remap files in the source manager (with buffers).
338  for (const auto &RB : InitOpts.RemappedFileBuffers) {
339    // Create the file entry for the file that we're mapping from.
340    const FileEntry *FromFile =
341        FileMgr.getVirtualFile(RB.first, RB.second->getBufferSize(), 0);
342    if (!FromFile) {
343      Diags.Report(diag::err_fe_remap_missing_from_file) << RB.first;
344      if (!InitOpts.RetainRemappedFileBuffers)
345        delete RB.second;
346      continue;
347    }
348
349    // Override the contents of the "from" file with the contents of
350    // the "to" file.
351    SourceMgr.overrideFileContents(FromFile, RB.second,
352                                   InitOpts.RetainRemappedFileBuffers);
353  }
354
355  // Remap files in the source manager (with other files).
356  for (const auto &RF : InitOpts.RemappedFiles) {
357    // Find the file that we're mapping to.
358    auto ToFile = FileMgr.getFile(RF.second);
359    if (!ToFile) {
360      Diags.Report(diag::err_fe_remap_missing_to_file) << RF.first << RF.second;
361      continue;
362    }
363
364    // Create the file entry for the file that we're mapping from.
365    const FileEntry *FromFile =
366        FileMgr.getVirtualFile(RF.first, (*ToFile)->getSize(), 0);
367    if (!FromFile) {
368      Diags.Report(diag::err_fe_remap_missing_from_file) << RF.first;
369      continue;
370    }
371
372    // Override the contents of the "from" file with the contents of
373    // the "to" file.
374    SourceMgr.overrideFileContents(FromFile, *ToFile);
375  }
376
377  SourceMgr.setOverridenFilesKeepOriginalName(
378      InitOpts.RemappedFilesKeepOriginalName);
379}
380
381// Preprocessor
382
383void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
384  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
385
386  // The AST reader holds a reference to the old preprocessor (if any).
387  TheASTReader.reset();
388
389  // Create the Preprocessor.
390  HeaderSearch *HeaderInfo =
391      new HeaderSearch(getHeaderSearchOptsPtr(), getSourceManager(),
392                       getDiagnostics(), getLangOpts(), &getTarget());
393  PP = std::make_shared<Preprocessor>(Invocation->getPreprocessorOptsPtr(),
394                                      getDiagnostics(), getLangOpts(),
395                                      getSourceManager(), *HeaderInfo, *this,
396                                      /*IdentifierInfoLookup=*/nullptr,
397                                      /*OwnsHeaderSearch=*/true, TUKind);
398  getTarget().adjust(getLangOpts());
399  PP->Initialize(getTarget(), getAuxTarget());
400
401  if (PPOpts.DetailedRecord)
402    PP->createPreprocessingRecord();
403
404  // Apply remappings to the source manager.
405  InitializeFileRemapping(PP->getDiagnostics(), PP->getSourceManager(),
406                          PP->getFileManager(), PPOpts);
407
408  // Predefine macros and configure the preprocessor.
409  InitializePreprocessor(*PP, PPOpts, getPCHContainerReader(),
410                         getFrontendOpts());
411
412  // Initialize the header search object.  In CUDA compilations, we use the aux
413  // triple (the host triple) to initialize our header search, since we need to
414  // find the host headers in order to compile the CUDA code.
415  const llvm::Triple *HeaderSearchTriple = &PP->getTargetInfo().getTriple();
416  if (PP->getTargetInfo().getTriple().getOS() == llvm::Triple::CUDA &&
417      PP->getAuxTargetInfo())
418    HeaderSearchTriple = &PP->getAuxTargetInfo()->getTriple();
419
420  ApplyHeaderSearchOptions(PP->getHeaderSearchInfo(), getHeaderSearchOpts(),
421                           PP->getLangOpts(), *HeaderSearchTriple);
422
423  PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
424
425  if (PP->getLangOpts().Modules && PP->getLangOpts().ImplicitModules)
426    PP->getHeaderSearchInfo().setModuleCachePath(getSpecificModuleCachePath());
427
428  // Handle generating dependencies, if requested.
429  const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
430  if (!DepOpts.OutputFile.empty())
431    addDependencyCollector(std::make_shared<DependencyFileGenerator>(DepOpts));
432  if (!DepOpts.DOTOutputFile.empty())
433    AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
434                             getHeaderSearchOpts().Sysroot);
435
436  // If we don't have a collector, but we are collecting module dependencies,
437  // then we're the top level compiler instance and need to create one.
438  if (!ModuleDepCollector && !DepOpts.ModuleDependencyOutputDir.empty()) {
439    ModuleDepCollector = std::make_shared<ModuleDependencyCollector>(
440        DepOpts.ModuleDependencyOutputDir);
441  }
442
443  // If there is a module dep collector, register with other dep collectors
444  // and also (a) collect header maps and (b) TODO: input vfs overlay files.
445  if (ModuleDepCollector) {
446    addDependencyCollector(ModuleDepCollector);
447    collectHeaderMaps(PP->getHeaderSearchInfo(), ModuleDepCollector);
448    collectIncludePCH(*this, ModuleDepCollector);
449    collectVFSEntries(*this, ModuleDepCollector);
450  }
451
452  for (auto &Listener : DependencyCollectors)
453    Listener->attachToPreprocessor(*PP);
454
455  // Handle generating header include information, if requested.
456  if (DepOpts.ShowHeaderIncludes)
457    AttachHeaderIncludeGen(*PP, DepOpts);
458  if (!DepOpts.HeaderIncludeOutputFile.empty()) {
459    StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
460    if (OutputPath == "-")
461      OutputPath = "";
462    AttachHeaderIncludeGen(*PP, DepOpts,
463                           /*ShowAllHeaders=*/true, OutputPath,
464                           /*ShowDepth=*/false);
465  }
466
467  if (DepOpts.ShowIncludesDest != ShowIncludesDestination::None) {
468    AttachHeaderIncludeGen(*PP, DepOpts,
469                           /*ShowAllHeaders=*/true, /*OutputPath=*/"",
470                           /*ShowDepth=*/true, /*MSStyle=*/true);
471  }
472}
473
474std::string CompilerInstance::getSpecificModuleCachePath() {
475  // Set up the module path, including the hash for the
476  // module-creation options.
477  SmallString<256> SpecificModuleCache(getHeaderSearchOpts().ModuleCachePath);
478  if (!SpecificModuleCache.empty() && !getHeaderSearchOpts().DisableModuleHash)
479    llvm::sys::path::append(SpecificModuleCache,
480                            getInvocation().getModuleHash());
481  return std::string(SpecificModuleCache.str());
482}
483
484// ASTContext
485
486void CompilerInstance::createASTContext() {
487  Preprocessor &PP = getPreprocessor();
488  auto *Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
489                                 PP.getIdentifierTable(), PP.getSelectorTable(),
490                                 PP.getBuiltinInfo());
491  Context->InitBuiltinTypes(getTarget(), getAuxTarget());
492  setASTContext(Context);
493}
494
495// ExternalASTSource
496
497void CompilerInstance::createPCHExternalASTSource(
498    StringRef Path, bool DisablePCHValidation, bool AllowPCHWithCompilerErrors,
499    void *DeserializationListener, bool OwnDeserializationListener) {
500  bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
501  TheASTReader = createPCHExternalASTSource(
502      Path, getHeaderSearchOpts().Sysroot, DisablePCHValidation,
503      AllowPCHWithCompilerErrors, getPreprocessor(), getModuleCache(),
504      getASTContext(), getPCHContainerReader(),
505      getFrontendOpts().ModuleFileExtensions, DependencyCollectors,
506      DeserializationListener, OwnDeserializationListener, Preamble,
507      getFrontendOpts().UseGlobalModuleIndex);
508}
509
510IntrusiveRefCntPtr<ASTReader> CompilerInstance::createPCHExternalASTSource(
511    StringRef Path, StringRef Sysroot, bool DisablePCHValidation,
512    bool AllowPCHWithCompilerErrors, Preprocessor &PP,
513    InMemoryModuleCache &ModuleCache, ASTContext &Context,
514    const PCHContainerReader &PCHContainerRdr,
515    ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
516    ArrayRef<std::shared_ptr<DependencyCollector>> DependencyCollectors,
517    void *DeserializationListener, bool OwnDeserializationListener,
518    bool Preamble, bool UseGlobalModuleIndex) {
519  HeaderSearchOptions &HSOpts = PP.getHeaderSearchInfo().getHeaderSearchOpts();
520
521  IntrusiveRefCntPtr<ASTReader> Reader(new ASTReader(
522      PP, ModuleCache, &Context, PCHContainerRdr, Extensions,
523      Sysroot.empty() ? "" : Sysroot.data(), DisablePCHValidation,
524      AllowPCHWithCompilerErrors, /*AllowConfigurationMismatch*/ false,
525      HSOpts.ModulesValidateSystemHeaders, HSOpts.ValidateASTInputFilesContent,
526      UseGlobalModuleIndex));
527
528  // We need the external source to be set up before we read the AST, because
529  // eagerly-deserialized declarations may use it.
530  Context.setExternalSource(Reader.get());
531
532  Reader->setDeserializationListener(
533      static_cast<ASTDeserializationListener *>(DeserializationListener),
534      /*TakeOwnership=*/OwnDeserializationListener);
535
536  for (auto &Listener : DependencyCollectors)
537    Listener->attachToASTReader(*Reader);
538
539  switch (Reader->ReadAST(Path,
540                          Preamble ? serialization::MK_Preamble
541                                   : serialization::MK_PCH,
542                          SourceLocation(),
543                          ASTReader::ARR_None)) {
544  case ASTReader::Success:
545    // Set the predefines buffer as suggested by the PCH reader. Typically, the
546    // predefines buffer will be empty.
547    PP.setPredefines(Reader->getSuggestedPredefines());
548    return Reader;
549
550  case ASTReader::Failure:
551    // Unrecoverable failure: don't even try to process the input file.
552    break;
553
554  case ASTReader::Missing:
555  case ASTReader::OutOfDate:
556  case ASTReader::VersionMismatch:
557  case ASTReader::ConfigurationMismatch:
558  case ASTReader::HadErrors:
559    // No suitable PCH file could be found. Return an error.
560    break;
561  }
562
563  Context.setExternalSource(nullptr);
564  return nullptr;
565}
566
567// Code Completion
568
569static bool EnableCodeCompletion(Preprocessor &PP,
570                                 StringRef Filename,
571                                 unsigned Line,
572                                 unsigned Column) {
573  // Tell the source manager to chop off the given file at a specific
574  // line and column.
575  auto Entry = PP.getFileManager().getFile(Filename);
576  if (!Entry) {
577    PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
578      << Filename;
579    return true;
580  }
581
582  // Truncate the named file at the given line/column.
583  PP.SetCodeCompletionPoint(*Entry, Line, Column);
584  return false;
585}
586
587void CompilerInstance::createCodeCompletionConsumer() {
588  const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
589  if (!CompletionConsumer) {
590    setCodeCompletionConsumer(
591      createCodeCompletionConsumer(getPreprocessor(),
592                                   Loc.FileName, Loc.Line, Loc.Column,
593                                   getFrontendOpts().CodeCompleteOpts,
594                                   llvm::outs()));
595    if (!CompletionConsumer)
596      return;
597  } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
598                                  Loc.Line, Loc.Column)) {
599    setCodeCompletionConsumer(nullptr);
600    return;
601  }
602}
603
604void CompilerInstance::createFrontendTimer() {
605  FrontendTimerGroup.reset(
606      new llvm::TimerGroup("frontend", "Clang front-end time report"));
607  FrontendTimer.reset(
608      new llvm::Timer("frontend", "Clang front-end timer",
609                      *FrontendTimerGroup));
610}
611
612CodeCompleteConsumer *
613CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
614                                               StringRef Filename,
615                                               unsigned Line,
616                                               unsigned Column,
617                                               const CodeCompleteOptions &Opts,
618                                               raw_ostream &OS) {
619  if (EnableCodeCompletion(PP, Filename, Line, Column))
620    return nullptr;
621
622  // Set up the creation routine for code-completion.
623  return new PrintingCodeCompleteConsumer(Opts, OS);
624}
625
626void CompilerInstance::createSema(TranslationUnitKind TUKind,
627                                  CodeCompleteConsumer *CompletionConsumer) {
628  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
629                         TUKind, CompletionConsumer));
630  // Attach the external sema source if there is any.
631  if (ExternalSemaSrc) {
632    TheSema->addExternalSource(ExternalSemaSrc.get());
633    ExternalSemaSrc->InitializeSema(*TheSema);
634  }
635}
636
637// Output Files
638
639void CompilerInstance::addOutputFile(OutputFile &&OutFile) {
640  OutputFiles.push_back(std::move(OutFile));
641}
642
643void CompilerInstance::clearOutputFiles(bool EraseFiles) {
644  for (OutputFile &OF : OutputFiles) {
645    if (!OF.TempFilename.empty()) {
646      if (EraseFiles) {
647        llvm::sys::fs::remove(OF.TempFilename);
648      } else {
649        SmallString<128> NewOutFile(OF.Filename);
650
651        // If '-working-directory' was passed, the output filename should be
652        // relative to that.
653        FileMgr->FixupRelativePath(NewOutFile);
654        if (std::error_code ec =
655                llvm::sys::fs::rename(OF.TempFilename, NewOutFile)) {
656          getDiagnostics().Report(diag::err_unable_to_rename_temp)
657            << OF.TempFilename << OF.Filename << ec.message();
658
659          llvm::sys::fs::remove(OF.TempFilename);
660        }
661      }
662    } else if (!OF.Filename.empty() && EraseFiles)
663      llvm::sys::fs::remove(OF.Filename);
664  }
665  OutputFiles.clear();
666  if (DeleteBuiltModules) {
667    for (auto &Module : BuiltModules)
668      llvm::sys::fs::remove(Module.second);
669    BuiltModules.clear();
670  }
671  NonSeekStream.reset();
672}
673
674std::unique_ptr<raw_pwrite_stream>
675CompilerInstance::createDefaultOutputFile(bool Binary, StringRef InFile,
676                                          StringRef Extension) {
677  return createOutputFile(getFrontendOpts().OutputFile, Binary,
678                          /*RemoveFileOnSignal=*/true, InFile, Extension,
679                          getFrontendOpts().UseTemporary);
680}
681
682std::unique_ptr<raw_pwrite_stream> CompilerInstance::createNullOutputFile() {
683  return std::make_unique<llvm::raw_null_ostream>();
684}
685
686std::unique_ptr<raw_pwrite_stream>
687CompilerInstance::createOutputFile(StringRef OutputPath, bool Binary,
688                                   bool RemoveFileOnSignal, StringRef InFile,
689                                   StringRef Extension, bool UseTemporary,
690                                   bool CreateMissingDirectories) {
691  std::string OutputPathName, TempPathName;
692  std::error_code EC;
693  std::unique_ptr<raw_pwrite_stream> OS = createOutputFile(
694      OutputPath, EC, Binary, RemoveFileOnSignal, InFile, Extension,
695      UseTemporary, CreateMissingDirectories, &OutputPathName, &TempPathName);
696  if (!OS) {
697    getDiagnostics().Report(diag::err_fe_unable_to_open_output) << OutputPath
698                                                                << EC.message();
699    return nullptr;
700  }
701
702  // Add the output file -- but don't try to remove "-", since this means we are
703  // using stdin.
704  addOutputFile(
705      OutputFile((OutputPathName != "-") ? OutputPathName : "", TempPathName));
706
707  return OS;
708}
709
710std::unique_ptr<llvm::raw_pwrite_stream> CompilerInstance::createOutputFile(
711    StringRef OutputPath, std::error_code &Error, bool Binary,
712    bool RemoveFileOnSignal, StringRef InFile, StringRef Extension,
713    bool UseTemporary, bool CreateMissingDirectories,
714    std::string *ResultPathName, std::string *TempPathName) {
715  assert((!CreateMissingDirectories || UseTemporary) &&
716         "CreateMissingDirectories is only allowed when using temporary files");
717
718  std::string OutFile, TempFile;
719  if (!OutputPath.empty()) {
720    OutFile = std::string(OutputPath);
721  } else if (InFile == "-") {
722    OutFile = "-";
723  } else if (!Extension.empty()) {
724    SmallString<128> Path(InFile);
725    llvm::sys::path::replace_extension(Path, Extension);
726    OutFile = std::string(Path.str());
727  } else {
728    OutFile = "-";
729  }
730
731  std::unique_ptr<llvm::raw_fd_ostream> OS;
732  std::string OSFile;
733
734  if (UseTemporary) {
735    if (OutFile == "-")
736      UseTemporary = false;
737    else {
738      llvm::sys::fs::file_status Status;
739      llvm::sys::fs::status(OutputPath, Status);
740      if (llvm::sys::fs::exists(Status)) {
741        // Fail early if we can't write to the final destination.
742        if (!llvm::sys::fs::can_write(OutputPath)) {
743          Error = make_error_code(llvm::errc::operation_not_permitted);
744          return nullptr;
745        }
746
747        // Don't use a temporary if the output is a special file. This handles
748        // things like '-o /dev/null'
749        if (!llvm::sys::fs::is_regular_file(Status))
750          UseTemporary = false;
751      }
752    }
753  }
754
755  if (UseTemporary) {
756    // Create a temporary file.
757    // Insert -%%%%%%%% before the extension (if any), and because some tools
758    // (noticeable, clang's own GlobalModuleIndex.cpp) glob for build
759    // artifacts, also append .tmp.
760    StringRef OutputExtension = llvm::sys::path::extension(OutFile);
761    SmallString<128> TempPath =
762        StringRef(OutFile).drop_back(OutputExtension.size());
763    TempPath += "-%%%%%%%%";
764    TempPath += OutputExtension;
765    TempPath += ".tmp";
766    int fd;
767    std::error_code EC =
768        llvm::sys::fs::createUniqueFile(TempPath, fd, TempPath);
769
770    if (CreateMissingDirectories &&
771        EC == llvm::errc::no_such_file_or_directory) {
772      StringRef Parent = llvm::sys::path::parent_path(OutputPath);
773      EC = llvm::sys::fs::create_directories(Parent);
774      if (!EC) {
775        EC = llvm::sys::fs::createUniqueFile(TempPath, fd, TempPath);
776      }
777    }
778
779    if (!EC) {
780      OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
781      OSFile = TempFile = std::string(TempPath.str());
782    }
783    // If we failed to create the temporary, fallback to writing to the file
784    // directly. This handles the corner case where we cannot write to the
785    // directory, but can write to the file.
786  }
787
788  if (!OS) {
789    OSFile = OutFile;
790    OS.reset(new llvm::raw_fd_ostream(
791        OSFile, Error,
792        (Binary ? llvm::sys::fs::OF_None : llvm::sys::fs::OF_Text)));
793    if (Error)
794      return nullptr;
795  }
796
797  // Make sure the out stream file gets removed if we crash.
798  if (RemoveFileOnSignal)
799    llvm::sys::RemoveFileOnSignal(OSFile);
800
801  if (ResultPathName)
802    *ResultPathName = OutFile;
803  if (TempPathName)
804    *TempPathName = TempFile;
805
806  if (!Binary || OS->supportsSeeking())
807    return std::move(OS);
808
809  auto B = std::make_unique<llvm::buffer_ostream>(*OS);
810  assert(!NonSeekStream);
811  NonSeekStream = std::move(OS);
812  return std::move(B);
813}
814
815// Initialization Utilities
816
817bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
818  return InitializeSourceManager(Input, getDiagnostics(), getFileManager(),
819                                 getSourceManager());
820}
821
822// static
823bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input,
824                                               DiagnosticsEngine &Diags,
825                                               FileManager &FileMgr,
826                                               SourceManager &SourceMgr) {
827  SrcMgr::CharacteristicKind Kind =
828      Input.getKind().getFormat() == InputKind::ModuleMap
829          ? Input.isSystem() ? SrcMgr::C_System_ModuleMap
830                             : SrcMgr::C_User_ModuleMap
831          : Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
832
833  if (Input.isBuffer()) {
834    SourceMgr.setMainFileID(SourceMgr.createFileID(SourceManager::Unowned,
835                                                   Input.getBuffer(), Kind));
836    assert(SourceMgr.getMainFileID().isValid() &&
837           "Couldn't establish MainFileID!");
838    return true;
839  }
840
841  StringRef InputFile = Input.getFile();
842
843  // Figure out where to get and map in the main file.
844  if (InputFile != "-") {
845    auto FileOrErr = FileMgr.getFileRef(InputFile, /*OpenFile=*/true);
846    if (!FileOrErr) {
847      // FIXME: include the error in the diagnostic.
848      consumeError(FileOrErr.takeError());
849      Diags.Report(diag::err_fe_error_reading) << InputFile;
850      return false;
851    }
852    FileEntryRef File = *FileOrErr;
853
854    // The natural SourceManager infrastructure can't currently handle named
855    // pipes, but we would at least like to accept them for the main
856    // file. Detect them here, read them with the volatile flag so FileMgr will
857    // pick up the correct size, and simply override their contents as we do for
858    // STDIN.
859    if (File.getFileEntry().isNamedPipe()) {
860      auto MB =
861          FileMgr.getBufferForFile(&File.getFileEntry(), /*isVolatile=*/true);
862      if (MB) {
863        // Create a new virtual file that will have the correct size.
864        const FileEntry *FE =
865            FileMgr.getVirtualFile(InputFile, (*MB)->getBufferSize(), 0);
866        SourceMgr.overrideFileContents(FE, std::move(*MB));
867        SourceMgr.setMainFileID(
868            SourceMgr.createFileID(FE, SourceLocation(), Kind));
869      } else {
870        Diags.Report(diag::err_cannot_open_file) << InputFile
871                                                 << MB.getError().message();
872        return false;
873      }
874    } else {
875      SourceMgr.setMainFileID(
876          SourceMgr.createFileID(File, SourceLocation(), Kind));
877    }
878  } else {
879    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> SBOrErr =
880        llvm::MemoryBuffer::getSTDIN();
881    if (std::error_code EC = SBOrErr.getError()) {
882      Diags.Report(diag::err_fe_error_reading_stdin) << EC.message();
883      return false;
884    }
885    std::unique_ptr<llvm::MemoryBuffer> SB = std::move(SBOrErr.get());
886
887    const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
888                                                   SB->getBufferSize(), 0);
889    SourceMgr.setMainFileID(
890        SourceMgr.createFileID(File, SourceLocation(), Kind));
891    SourceMgr.overrideFileContents(File, std::move(SB));
892  }
893
894  assert(SourceMgr.getMainFileID().isValid() &&
895         "Couldn't establish MainFileID!");
896  return true;
897}
898
899// High-Level Operations
900
901bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
902  assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
903  assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
904  assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
905
906  // Mark this point as the bottom of the stack if we don't have somewhere
907  // better. We generally expect frontend actions to be invoked with (nearly)
908  // DesiredStackSpace available.
909  noteBottomOfStack();
910
911  raw_ostream &OS = getVerboseOutputStream();
912
913  if (!Act.PrepareToExecute(*this))
914    return false;
915
916  // Create the target instance.
917  setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(),
918                                         getInvocation().TargetOpts));
919  if (!hasTarget())
920    return false;
921
922  // Create TargetInfo for the other side of CUDA/OpenMP/SYCL compilation.
923  if ((getLangOpts().CUDA || getLangOpts().OpenMPIsDevice ||
924       getLangOpts().SYCLIsDevice) &&
925      !getFrontendOpts().AuxTriple.empty()) {
926    auto TO = std::make_shared<TargetOptions>();
927    TO->Triple = llvm::Triple::normalize(getFrontendOpts().AuxTriple);
928    if (getFrontendOpts().AuxTargetCPU)
929      TO->CPU = getFrontendOpts().AuxTargetCPU.getValue();
930    if (getFrontendOpts().AuxTargetFeatures)
931      TO->FeaturesAsWritten = getFrontendOpts().AuxTargetFeatures.getValue();
932    TO->HostTriple = getTarget().getTriple().str();
933    setAuxTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), TO));
934  }
935
936  if (!getTarget().hasStrictFP() && !getLangOpts().ExpStrictFP) {
937    if (getLangOpts().getFPRoundingMode() !=
938        llvm::RoundingMode::NearestTiesToEven) {
939      getDiagnostics().Report(diag::warn_fe_backend_unsupported_fp_rounding);
940      getLangOpts().setFPRoundingMode(llvm::RoundingMode::NearestTiesToEven);
941    }
942    if (getLangOpts().getFPExceptionMode() != LangOptions::FPE_Ignore) {
943      getDiagnostics().Report(diag::warn_fe_backend_unsupported_fp_exceptions);
944      getLangOpts().setFPExceptionMode(LangOptions::FPE_Ignore);
945    }
946    // FIXME: can we disable FEnvAccess?
947  }
948
949  // Inform the target of the language options.
950  //
951  // FIXME: We shouldn't need to do this, the target should be immutable once
952  // created. This complexity should be lifted elsewhere.
953  getTarget().adjust(getLangOpts());
954
955  // Adjust target options based on codegen options.
956  getTarget().adjustTargetOptions(getCodeGenOpts(), getTargetOpts());
957
958  if (auto *Aux = getAuxTarget())
959    getTarget().setAuxTarget(Aux);
960
961  // rewriter project will change target built-in bool type from its default.
962  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
963    getTarget().noSignedCharForObjCBool();
964
965  // Validate/process some options.
966  if (getHeaderSearchOpts().Verbose)
967    OS << "clang -cc1 version " CLANG_VERSION_STRING
968       << " based upon " << BACKEND_PACKAGE_STRING
969       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
970
971  if (getFrontendOpts().ShowTimers)
972    createFrontendTimer();
973
974  if (getFrontendOpts().ShowStats || !getFrontendOpts().StatsFile.empty())
975    llvm::EnableStatistics(false);
976
977  for (const FrontendInputFile &FIF : getFrontendOpts().Inputs) {
978    // Reset the ID tables if we are reusing the SourceManager and parsing
979    // regular files.
980    if (hasSourceManager() && !Act.isModelParsingAction())
981      getSourceManager().clearIDTables();
982
983    if (Act.BeginSourceFile(*this, FIF)) {
984      if (llvm::Error Err = Act.Execute()) {
985        consumeError(std::move(Err)); // FIXME this drops errors on the floor.
986      }
987      Act.EndSourceFile();
988    }
989  }
990
991  // Notify the diagnostic client that all files were processed.
992  getDiagnostics().getClient()->finish();
993
994  if (getDiagnosticOpts().ShowCarets) {
995    // We can have multiple diagnostics sharing one diagnostic client.
996    // Get the total number of warnings/errors from the client.
997    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
998    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
999
1000    if (NumWarnings)
1001      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
1002    if (NumWarnings && NumErrors)
1003      OS << " and ";
1004    if (NumErrors)
1005      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
1006    if (NumWarnings || NumErrors) {
1007      OS << " generated";
1008      if (getLangOpts().CUDA) {
1009        if (!getLangOpts().CUDAIsDevice) {
1010          OS << " when compiling for host";
1011        } else {
1012          OS << " when compiling for " << getTargetOpts().CPU;
1013        }
1014      }
1015      OS << ".\n";
1016    }
1017  }
1018
1019  if (getFrontendOpts().ShowStats) {
1020    if (hasFileManager()) {
1021      getFileManager().PrintStats();
1022      OS << '\n';
1023    }
1024    llvm::PrintStatistics(OS);
1025  }
1026  StringRef StatsFile = getFrontendOpts().StatsFile;
1027  if (!StatsFile.empty()) {
1028    std::error_code EC;
1029    auto StatS = std::make_unique<llvm::raw_fd_ostream>(
1030        StatsFile, EC, llvm::sys::fs::OF_Text);
1031    if (EC) {
1032      getDiagnostics().Report(diag::warn_fe_unable_to_open_stats_file)
1033          << StatsFile << EC.message();
1034    } else {
1035      llvm::PrintStatisticsJSON(*StatS);
1036    }
1037  }
1038
1039  return !getDiagnostics().getClient()->getNumErrors();
1040}
1041
1042/// Determine the appropriate source input kind based on language
1043/// options.
1044static Language getLanguageFromOptions(const LangOptions &LangOpts) {
1045  if (LangOpts.OpenCL)
1046    return Language::OpenCL;
1047  if (LangOpts.CUDA)
1048    return Language::CUDA;
1049  if (LangOpts.ObjC)
1050    return LangOpts.CPlusPlus ? Language::ObjCXX : Language::ObjC;
1051  return LangOpts.CPlusPlus ? Language::CXX : Language::C;
1052}
1053
1054/// Compile a module file for the given module, using the options
1055/// provided by the importing compiler instance. Returns true if the module
1056/// was built without errors.
1057static bool
1058compileModuleImpl(CompilerInstance &ImportingInstance, SourceLocation ImportLoc,
1059                  StringRef ModuleName, FrontendInputFile Input,
1060                  StringRef OriginalModuleMapFile, StringRef ModuleFileName,
1061                  llvm::function_ref<void(CompilerInstance &)> PreBuildStep =
1062                      [](CompilerInstance &) {},
1063                  llvm::function_ref<void(CompilerInstance &)> PostBuildStep =
1064                      [](CompilerInstance &) {}) {
1065  llvm::TimeTraceScope TimeScope("Module Compile", ModuleName);
1066
1067  // Construct a compiler invocation for creating this module.
1068  auto Invocation =
1069      std::make_shared<CompilerInvocation>(ImportingInstance.getInvocation());
1070
1071  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
1072
1073  // For any options that aren't intended to affect how a module is built,
1074  // reset them to their default values.
1075  Invocation->getLangOpts()->resetNonModularOptions();
1076  PPOpts.resetNonModularOptions();
1077
1078  // Remove any macro definitions that are explicitly ignored by the module.
1079  // They aren't supposed to affect how the module is built anyway.
1080  HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
1081  PPOpts.Macros.erase(
1082      std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
1083                     [&HSOpts](const std::pair<std::string, bool> &def) {
1084        StringRef MacroDef = def.first;
1085        return HSOpts.ModulesIgnoreMacros.count(
1086                   llvm::CachedHashString(MacroDef.split('=').first)) > 0;
1087      }),
1088      PPOpts.Macros.end());
1089
1090  // If the original compiler invocation had -fmodule-name, pass it through.
1091  Invocation->getLangOpts()->ModuleName =
1092      ImportingInstance.getInvocation().getLangOpts()->ModuleName;
1093
1094  // Note the name of the module we're building.
1095  Invocation->getLangOpts()->CurrentModule = std::string(ModuleName);
1096
1097  // Make sure that the failed-module structure has been allocated in
1098  // the importing instance, and propagate the pointer to the newly-created
1099  // instance.
1100  PreprocessorOptions &ImportingPPOpts
1101    = ImportingInstance.getInvocation().getPreprocessorOpts();
1102  if (!ImportingPPOpts.FailedModules)
1103    ImportingPPOpts.FailedModules =
1104        std::make_shared<PreprocessorOptions::FailedModulesSet>();
1105  PPOpts.FailedModules = ImportingPPOpts.FailedModules;
1106
1107  // If there is a module map file, build the module using the module map.
1108  // Set up the inputs/outputs so that we build the module from its umbrella
1109  // header.
1110  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
1111  FrontendOpts.OutputFile = ModuleFileName.str();
1112  FrontendOpts.DisableFree = false;
1113  FrontendOpts.GenerateGlobalModuleIndex = false;
1114  FrontendOpts.BuildingImplicitModule = true;
1115  FrontendOpts.OriginalModuleMap = std::string(OriginalModuleMapFile);
1116  // Force implicitly-built modules to hash the content of the module file.
1117  HSOpts.ModulesHashContent = true;
1118  FrontendOpts.Inputs = {Input};
1119
1120  // Don't free the remapped file buffers; they are owned by our caller.
1121  PPOpts.RetainRemappedFileBuffers = true;
1122
1123  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
1124  assert(ImportingInstance.getInvocation().getModuleHash() ==
1125         Invocation->getModuleHash() && "Module hash mismatch!");
1126
1127  // Construct a compiler instance that will be used to actually create the
1128  // module.  Since we're sharing an in-memory module cache,
1129  // CompilerInstance::CompilerInstance is responsible for finalizing the
1130  // buffers to prevent use-after-frees.
1131  CompilerInstance Instance(ImportingInstance.getPCHContainerOperations(),
1132                            &ImportingInstance.getModuleCache());
1133  auto &Inv = *Invocation;
1134  Instance.setInvocation(std::move(Invocation));
1135
1136  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
1137                                   ImportingInstance.getDiagnosticClient()),
1138                             /*ShouldOwnClient=*/true);
1139
1140  // Note that this module is part of the module build stack, so that we
1141  // can detect cycles in the module graph.
1142  Instance.setFileManager(&ImportingInstance.getFileManager());
1143  Instance.createSourceManager(Instance.getFileManager());
1144  SourceManager &SourceMgr = Instance.getSourceManager();
1145  SourceMgr.setModuleBuildStack(
1146    ImportingInstance.getSourceManager().getModuleBuildStack());
1147  SourceMgr.pushModuleBuildStack(ModuleName,
1148    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
1149
1150  // If we're collecting module dependencies, we need to share a collector
1151  // between all of the module CompilerInstances. Other than that, we don't
1152  // want to produce any dependency output from the module build.
1153  Instance.setModuleDepCollector(ImportingInstance.getModuleDepCollector());
1154  Inv.getDependencyOutputOpts() = DependencyOutputOptions();
1155
1156  ImportingInstance.getDiagnostics().Report(ImportLoc,
1157                                            diag::remark_module_build)
1158    << ModuleName << ModuleFileName;
1159
1160  PreBuildStep(Instance);
1161
1162  // Execute the action to actually build the module in-place. Use a separate
1163  // thread so that we get a stack large enough.
1164  llvm::CrashRecoveryContext CRC;
1165  CRC.RunSafelyOnThread(
1166      [&]() {
1167        GenerateModuleFromModuleMapAction Action;
1168        Instance.ExecuteAction(Action);
1169      },
1170      DesiredStackSize);
1171
1172  PostBuildStep(Instance);
1173
1174  ImportingInstance.getDiagnostics().Report(ImportLoc,
1175                                            diag::remark_module_build_done)
1176    << ModuleName;
1177
1178  // Delete the temporary module map file.
1179  // FIXME: Even though we're executing under crash protection, it would still
1180  // be nice to do this with RemoveFileOnSignal when we can. However, that
1181  // doesn't make sense for all clients, so clean this up manually.
1182  Instance.clearOutputFiles(/*EraseFiles=*/true);
1183
1184  return !Instance.getDiagnostics().hasErrorOccurred();
1185}
1186
1187static const FileEntry *getPublicModuleMap(const FileEntry *File,
1188                                           FileManager &FileMgr) {
1189  StringRef Filename = llvm::sys::path::filename(File->getName());
1190  SmallString<128> PublicFilename(File->getDir()->getName());
1191  if (Filename == "module_private.map")
1192    llvm::sys::path::append(PublicFilename, "module.map");
1193  else if (Filename == "module.private.modulemap")
1194    llvm::sys::path::append(PublicFilename, "module.modulemap");
1195  else
1196    return nullptr;
1197  if (auto FE = FileMgr.getFile(PublicFilename))
1198    return *FE;
1199  return nullptr;
1200}
1201
1202/// Compile a module file for the given module in a separate compiler instance,
1203/// using the options provided by the importing compiler instance. Returns true
1204/// if the module was built without errors.
1205static bool compileModule(CompilerInstance &ImportingInstance,
1206                          SourceLocation ImportLoc, Module *Module,
1207                          StringRef ModuleFileName) {
1208  InputKind IK(getLanguageFromOptions(ImportingInstance.getLangOpts()),
1209               InputKind::ModuleMap);
1210
1211  // Get or create the module map that we'll use to build this module.
1212  ModuleMap &ModMap
1213    = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
1214  bool Result;
1215  if (const FileEntry *ModuleMapFile =
1216          ModMap.getContainingModuleMapFile(Module)) {
1217    // Canonicalize compilation to start with the public module map. This is
1218    // vital for submodules declarations in the private module maps to be
1219    // correctly parsed when depending on a top level module in the public one.
1220    if (const FileEntry *PublicMMFile = getPublicModuleMap(
1221            ModuleMapFile, ImportingInstance.getFileManager()))
1222      ModuleMapFile = PublicMMFile;
1223
1224    // Use the module map where this module resides.
1225    Result = compileModuleImpl(
1226        ImportingInstance, ImportLoc, Module->getTopLevelModuleName(),
1227        FrontendInputFile(ModuleMapFile->getName(), IK, +Module->IsSystem),
1228        ModMap.getModuleMapFileForUniquing(Module)->getName(),
1229        ModuleFileName);
1230  } else {
1231    // FIXME: We only need to fake up an input file here as a way of
1232    // transporting the module's directory to the module map parser. We should
1233    // be able to do that more directly, and parse from a memory buffer without
1234    // inventing this file.
1235    SmallString<128> FakeModuleMapFile(Module->Directory->getName());
1236    llvm::sys::path::append(FakeModuleMapFile, "__inferred_module.map");
1237
1238    std::string InferredModuleMapContent;
1239    llvm::raw_string_ostream OS(InferredModuleMapContent);
1240    Module->print(OS);
1241    OS.flush();
1242
1243    Result = compileModuleImpl(
1244        ImportingInstance, ImportLoc, Module->getTopLevelModuleName(),
1245        FrontendInputFile(FakeModuleMapFile, IK, +Module->IsSystem),
1246        ModMap.getModuleMapFileForUniquing(Module)->getName(),
1247        ModuleFileName,
1248        [&](CompilerInstance &Instance) {
1249      std::unique_ptr<llvm::MemoryBuffer> ModuleMapBuffer =
1250          llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
1251      ModuleMapFile = Instance.getFileManager().getVirtualFile(
1252          FakeModuleMapFile, InferredModuleMapContent.size(), 0);
1253      Instance.getSourceManager().overrideFileContents(
1254          ModuleMapFile, std::move(ModuleMapBuffer));
1255    });
1256  }
1257
1258  // We've rebuilt a module. If we're allowed to generate or update the global
1259  // module index, record that fact in the importing compiler instance.
1260  if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
1261    ImportingInstance.setBuildGlobalModuleIndex(true);
1262  }
1263
1264  return Result;
1265}
1266
1267/// Compile a module in a separate compiler instance and read the AST,
1268/// returning true if the module compiles without errors.
1269///
1270/// Uses a lock file manager and exponential backoff to reduce the chances that
1271/// multiple instances will compete to create the same module.  On timeout,
1272/// deletes the lock file in order to avoid deadlock from crashing processes or
1273/// bugs in the lock file manager.
1274static bool compileModuleAndReadAST(CompilerInstance &ImportingInstance,
1275                                    SourceLocation ImportLoc,
1276                                    SourceLocation ModuleNameLoc,
1277                                    Module *Module, StringRef ModuleFileName) {
1278  DiagnosticsEngine &Diags = ImportingInstance.getDiagnostics();
1279
1280  auto diagnoseBuildFailure = [&] {
1281    Diags.Report(ModuleNameLoc, diag::err_module_not_built)
1282        << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
1283  };
1284
1285  // FIXME: have LockFileManager return an error_code so that we can
1286  // avoid the mkdir when the directory already exists.
1287  StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
1288  llvm::sys::fs::create_directories(Dir);
1289
1290  while (1) {
1291    unsigned ModuleLoadCapabilities = ASTReader::ARR_Missing;
1292    llvm::LockFileManager Locked(ModuleFileName);
1293    switch (Locked) {
1294    case llvm::LockFileManager::LFS_Error:
1295      // ModuleCache takes care of correctness and locks are only necessary for
1296      // performance. Fallback to building the module in case of any lock
1297      // related errors.
1298      Diags.Report(ModuleNameLoc, diag::remark_module_lock_failure)
1299          << Module->Name << Locked.getErrorMessage();
1300      // Clear out any potential leftover.
1301      Locked.unsafeRemoveLockFile();
1302      LLVM_FALLTHROUGH;
1303    case llvm::LockFileManager::LFS_Owned:
1304      // We're responsible for building the module ourselves.
1305      if (!compileModule(ImportingInstance, ModuleNameLoc, Module,
1306                         ModuleFileName)) {
1307        diagnoseBuildFailure();
1308        return false;
1309      }
1310      break;
1311
1312    case llvm::LockFileManager::LFS_Shared:
1313      // Someone else is responsible for building the module. Wait for them to
1314      // finish.
1315      switch (Locked.waitForUnlock()) {
1316      case llvm::LockFileManager::Res_Success:
1317        ModuleLoadCapabilities |= ASTReader::ARR_OutOfDate;
1318        break;
1319      case llvm::LockFileManager::Res_OwnerDied:
1320        continue; // try again to get the lock.
1321      case llvm::LockFileManager::Res_Timeout:
1322        // Since ModuleCache takes care of correctness, we try waiting for
1323        // another process to complete the build so clang does not do it done
1324        // twice. If case of timeout, build it ourselves.
1325        Diags.Report(ModuleNameLoc, diag::remark_module_lock_timeout)
1326            << Module->Name;
1327        // Clear the lock file so that future invocations can make progress.
1328        Locked.unsafeRemoveLockFile();
1329        continue;
1330      }
1331      break;
1332    }
1333
1334    // Try to read the module file, now that we've compiled it.
1335    ASTReader::ASTReadResult ReadResult =
1336        ImportingInstance.getASTReader()->ReadAST(
1337            ModuleFileName, serialization::MK_ImplicitModule, ImportLoc,
1338            ModuleLoadCapabilities);
1339
1340    if (ReadResult == ASTReader::OutOfDate &&
1341        Locked == llvm::LockFileManager::LFS_Shared) {
1342      // The module may be out of date in the presence of file system races,
1343      // or if one of its imports depends on header search paths that are not
1344      // consistent with this ImportingInstance.  Try again...
1345      continue;
1346    } else if (ReadResult == ASTReader::Missing) {
1347      diagnoseBuildFailure();
1348    } else if (ReadResult != ASTReader::Success &&
1349               !Diags.hasErrorOccurred()) {
1350      // The ASTReader didn't diagnose the error, so conservatively report it.
1351      diagnoseBuildFailure();
1352    }
1353    return ReadResult == ASTReader::Success;
1354  }
1355}
1356
1357/// Diagnose differences between the current definition of the given
1358/// configuration macro and the definition provided on the command line.
1359static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
1360                             Module *Mod, SourceLocation ImportLoc) {
1361  IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
1362  SourceManager &SourceMgr = PP.getSourceManager();
1363
1364  // If this identifier has never had a macro definition, then it could
1365  // not have changed.
1366  if (!Id->hadMacroDefinition())
1367    return;
1368  auto *LatestLocalMD = PP.getLocalMacroDirectiveHistory(Id);
1369
1370  // Find the macro definition from the command line.
1371  MacroInfo *CmdLineDefinition = nullptr;
1372  for (auto *MD = LatestLocalMD; MD; MD = MD->getPrevious()) {
1373    // We only care about the predefines buffer.
1374    FileID FID = SourceMgr.getFileID(MD->getLocation());
1375    if (FID.isInvalid() || FID != PP.getPredefinesFileID())
1376      continue;
1377    if (auto *DMD = dyn_cast<DefMacroDirective>(MD))
1378      CmdLineDefinition = DMD->getMacroInfo();
1379    break;
1380  }
1381
1382  auto *CurrentDefinition = PP.getMacroInfo(Id);
1383  if (CurrentDefinition == CmdLineDefinition) {
1384    // Macro matches. Nothing to do.
1385  } else if (!CurrentDefinition) {
1386    // This macro was defined on the command line, then #undef'd later.
1387    // Complain.
1388    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1389      << true << ConfigMacro << Mod->getFullModuleName();
1390    auto LatestDef = LatestLocalMD->getDefinition();
1391    assert(LatestDef.isUndefined() &&
1392           "predefined macro went away with no #undef?");
1393    PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
1394      << true;
1395    return;
1396  } else if (!CmdLineDefinition) {
1397    // There was no definition for this macro in the predefines buffer,
1398    // but there was a local definition. Complain.
1399    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1400      << false << ConfigMacro << Mod->getFullModuleName();
1401    PP.Diag(CurrentDefinition->getDefinitionLoc(),
1402            diag::note_module_def_undef_here)
1403      << false;
1404  } else if (!CurrentDefinition->isIdenticalTo(*CmdLineDefinition, PP,
1405                                               /*Syntactically=*/true)) {
1406    // The macro definitions differ.
1407    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1408      << false << ConfigMacro << Mod->getFullModuleName();
1409    PP.Diag(CurrentDefinition->getDefinitionLoc(),
1410            diag::note_module_def_undef_here)
1411      << false;
1412  }
1413}
1414
1415/// Write a new timestamp file with the given path.
1416static void writeTimestampFile(StringRef TimestampFile) {
1417  std::error_code EC;
1418  llvm::raw_fd_ostream Out(TimestampFile.str(), EC, llvm::sys::fs::OF_None);
1419}
1420
1421/// Prune the module cache of modules that haven't been accessed in
1422/// a long time.
1423static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1424  llvm::sys::fs::file_status StatBuf;
1425  llvm::SmallString<128> TimestampFile;
1426  TimestampFile = HSOpts.ModuleCachePath;
1427  assert(!TimestampFile.empty());
1428  llvm::sys::path::append(TimestampFile, "modules.timestamp");
1429
1430  // Try to stat() the timestamp file.
1431  if (std::error_code EC = llvm::sys::fs::status(TimestampFile, StatBuf)) {
1432    // If the timestamp file wasn't there, create one now.
1433    if (EC == std::errc::no_such_file_or_directory) {
1434      writeTimestampFile(TimestampFile);
1435    }
1436    return;
1437  }
1438
1439  // Check whether the time stamp is older than our pruning interval.
1440  // If not, do nothing.
1441  time_t TimeStampModTime =
1442      llvm::sys::toTimeT(StatBuf.getLastModificationTime());
1443  time_t CurrentTime = time(nullptr);
1444  if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1445    return;
1446
1447  // Write a new timestamp file so that nobody else attempts to prune.
1448  // There is a benign race condition here, if two Clang instances happen to
1449  // notice at the same time that the timestamp is out-of-date.
1450  writeTimestampFile(TimestampFile);
1451
1452  // Walk the entire module cache, looking for unused module files and module
1453  // indices.
1454  std::error_code EC;
1455  SmallString<128> ModuleCachePathNative;
1456  llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1457  for (llvm::sys::fs::directory_iterator Dir(ModuleCachePathNative, EC), DirEnd;
1458       Dir != DirEnd && !EC; Dir.increment(EC)) {
1459    // If we don't have a directory, there's nothing to look into.
1460    if (!llvm::sys::fs::is_directory(Dir->path()))
1461      continue;
1462
1463    // Walk all of the files within this directory.
1464    for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1465         File != FileEnd && !EC; File.increment(EC)) {
1466      // We only care about module and global module index files.
1467      StringRef Extension = llvm::sys::path::extension(File->path());
1468      if (Extension != ".pcm" && Extension != ".timestamp" &&
1469          llvm::sys::path::filename(File->path()) != "modules.idx")
1470        continue;
1471
1472      // Look at this file. If we can't stat it, there's nothing interesting
1473      // there.
1474      if (llvm::sys::fs::status(File->path(), StatBuf))
1475        continue;
1476
1477      // If the file has been used recently enough, leave it there.
1478      time_t FileAccessTime = llvm::sys::toTimeT(StatBuf.getLastAccessedTime());
1479      if (CurrentTime - FileAccessTime <=
1480              time_t(HSOpts.ModuleCachePruneAfter)) {
1481        continue;
1482      }
1483
1484      // Remove the file.
1485      llvm::sys::fs::remove(File->path());
1486
1487      // Remove the timestamp file.
1488      std::string TimpestampFilename = File->path() + ".timestamp";
1489      llvm::sys::fs::remove(TimpestampFilename);
1490    }
1491
1492    // If we removed all of the files in the directory, remove the directory
1493    // itself.
1494    if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1495            llvm::sys::fs::directory_iterator() && !EC)
1496      llvm::sys::fs::remove(Dir->path());
1497  }
1498}
1499
1500void CompilerInstance::createASTReader() {
1501  if (TheASTReader)
1502    return;
1503
1504  if (!hasASTContext())
1505    createASTContext();
1506
1507  // If we're implicitly building modules but not currently recursively
1508  // building a module, check whether we need to prune the module cache.
1509  if (getSourceManager().getModuleBuildStack().empty() &&
1510      !getPreprocessor().getHeaderSearchInfo().getModuleCachePath().empty() &&
1511      getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1512      getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1513    pruneModuleCache(getHeaderSearchOpts());
1514  }
1515
1516  HeaderSearchOptions &HSOpts = getHeaderSearchOpts();
1517  std::string Sysroot = HSOpts.Sysroot;
1518  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1519  std::unique_ptr<llvm::Timer> ReadTimer;
1520  if (FrontendTimerGroup)
1521    ReadTimer = std::make_unique<llvm::Timer>("reading_modules",
1522                                                "Reading modules",
1523                                                *FrontendTimerGroup);
1524  TheASTReader = new ASTReader(
1525      getPreprocessor(), getModuleCache(), &getASTContext(),
1526      getPCHContainerReader(), getFrontendOpts().ModuleFileExtensions,
1527      Sysroot.empty() ? "" : Sysroot.c_str(), PPOpts.DisablePCHValidation,
1528      /*AllowASTWithCompilerErrors=*/false,
1529      /*AllowConfigurationMismatch=*/false, HSOpts.ModulesValidateSystemHeaders,
1530      HSOpts.ValidateASTInputFilesContent,
1531      getFrontendOpts().UseGlobalModuleIndex, std::move(ReadTimer));
1532  if (hasASTConsumer()) {
1533    TheASTReader->setDeserializationListener(
1534        getASTConsumer().GetASTDeserializationListener());
1535    getASTContext().setASTMutationListener(
1536      getASTConsumer().GetASTMutationListener());
1537  }
1538  getASTContext().setExternalSource(TheASTReader);
1539  if (hasSema())
1540    TheASTReader->InitializeSema(getSema());
1541  if (hasASTConsumer())
1542    TheASTReader->StartTranslationUnit(&getASTConsumer());
1543
1544  for (auto &Listener : DependencyCollectors)
1545    Listener->attachToASTReader(*TheASTReader);
1546}
1547
1548bool CompilerInstance::loadModuleFile(StringRef FileName) {
1549  llvm::Timer Timer;
1550  if (FrontendTimerGroup)
1551    Timer.init("preloading." + FileName.str(), "Preloading " + FileName.str(),
1552               *FrontendTimerGroup);
1553  llvm::TimeRegion TimeLoading(FrontendTimerGroup ? &Timer : nullptr);
1554
1555  // Helper to recursively read the module names for all modules we're adding.
1556  // We mark these as known and redirect any attempt to load that module to
1557  // the files we were handed.
1558  struct ReadModuleNames : ASTReaderListener {
1559    CompilerInstance &CI;
1560    llvm::SmallVector<IdentifierInfo*, 8> LoadedModules;
1561
1562    ReadModuleNames(CompilerInstance &CI) : CI(CI) {}
1563
1564    void ReadModuleName(StringRef ModuleName) override {
1565      LoadedModules.push_back(
1566          CI.getPreprocessor().getIdentifierInfo(ModuleName));
1567    }
1568
1569    void registerAll() {
1570      ModuleMap &MM = CI.getPreprocessor().getHeaderSearchInfo().getModuleMap();
1571      for (auto *II : LoadedModules)
1572        MM.cacheModuleLoad(*II, MM.findModule(II->getName()));
1573      LoadedModules.clear();
1574    }
1575
1576    void markAllUnavailable() {
1577      for (auto *II : LoadedModules) {
1578        if (Module *M = CI.getPreprocessor()
1579                            .getHeaderSearchInfo()
1580                            .getModuleMap()
1581                            .findModule(II->getName())) {
1582          M->HasIncompatibleModuleFile = true;
1583
1584          // Mark module as available if the only reason it was unavailable
1585          // was missing headers.
1586          SmallVector<Module *, 2> Stack;
1587          Stack.push_back(M);
1588          while (!Stack.empty()) {
1589            Module *Current = Stack.pop_back_val();
1590            if (Current->IsUnimportable) continue;
1591            Current->IsAvailable = true;
1592            Stack.insert(Stack.end(),
1593                         Current->submodule_begin(), Current->submodule_end());
1594          }
1595        }
1596      }
1597      LoadedModules.clear();
1598    }
1599  };
1600
1601  // If we don't already have an ASTReader, create one now.
1602  if (!TheASTReader)
1603    createASTReader();
1604
1605  // If -Wmodule-file-config-mismatch is mapped as an error or worse, allow the
1606  // ASTReader to diagnose it, since it can produce better errors that we can.
1607  bool ConfigMismatchIsRecoverable =
1608      getDiagnostics().getDiagnosticLevel(diag::warn_module_config_mismatch,
1609                                          SourceLocation())
1610        <= DiagnosticsEngine::Warning;
1611
1612  auto Listener = std::make_unique<ReadModuleNames>(*this);
1613  auto &ListenerRef = *Listener;
1614  ASTReader::ListenerScope ReadModuleNamesListener(*TheASTReader,
1615                                                   std::move(Listener));
1616
1617  // Try to load the module file.
1618  switch (TheASTReader->ReadAST(
1619      FileName, serialization::MK_ExplicitModule, SourceLocation(),
1620      ConfigMismatchIsRecoverable ? ASTReader::ARR_ConfigurationMismatch : 0)) {
1621  case ASTReader::Success:
1622    // We successfully loaded the module file; remember the set of provided
1623    // modules so that we don't try to load implicit modules for them.
1624    ListenerRef.registerAll();
1625    return true;
1626
1627  case ASTReader::ConfigurationMismatch:
1628    // Ignore unusable module files.
1629    getDiagnostics().Report(SourceLocation(), diag::warn_module_config_mismatch)
1630        << FileName;
1631    // All modules provided by any files we tried and failed to load are now
1632    // unavailable; includes of those modules should now be handled textually.
1633    ListenerRef.markAllUnavailable();
1634    return true;
1635
1636  default:
1637    return false;
1638  }
1639}
1640
1641namespace {
1642enum ModuleSource {
1643  MS_ModuleNotFound,
1644  MS_ModuleCache,
1645  MS_PrebuiltModulePath,
1646  MS_ModuleBuildPragma
1647};
1648} // end namespace
1649
1650/// Select a source for loading the named module and compute the filename to
1651/// load it from.
1652static ModuleSource selectModuleSource(
1653    Module *M, StringRef ModuleName, std::string &ModuleFilename,
1654    const std::map<std::string, std::string, std::less<>> &BuiltModules,
1655    HeaderSearch &HS) {
1656  assert(ModuleFilename.empty() && "Already has a module source?");
1657
1658  // Check to see if the module has been built as part of this compilation
1659  // via a module build pragma.
1660  auto BuiltModuleIt = BuiltModules.find(ModuleName);
1661  if (BuiltModuleIt != BuiltModules.end()) {
1662    ModuleFilename = BuiltModuleIt->second;
1663    return MS_ModuleBuildPragma;
1664  }
1665
1666  // Try to load the module from the prebuilt module path.
1667  const HeaderSearchOptions &HSOpts = HS.getHeaderSearchOpts();
1668  if (!HSOpts.PrebuiltModuleFiles.empty() ||
1669      !HSOpts.PrebuiltModulePaths.empty()) {
1670    ModuleFilename = HS.getPrebuiltModuleFileName(ModuleName);
1671    if (!ModuleFilename.empty())
1672      return MS_PrebuiltModulePath;
1673  }
1674
1675  // Try to load the module from the module cache.
1676  if (M) {
1677    ModuleFilename = HS.getCachedModuleFileName(M);
1678    return MS_ModuleCache;
1679  }
1680
1681  return MS_ModuleNotFound;
1682}
1683
1684ModuleLoadResult CompilerInstance::findOrCompileModuleAndReadAST(
1685    StringRef ModuleName, SourceLocation ImportLoc,
1686    SourceLocation ModuleNameLoc, bool IsInclusionDirective) {
1687  // Search for a module with the given name.
1688  HeaderSearch &HS = PP->getHeaderSearchInfo();
1689  Module *M = HS.lookupModule(ModuleName, true, !IsInclusionDirective);
1690
1691  // Select the source and filename for loading the named module.
1692  std::string ModuleFilename;
1693  ModuleSource Source =
1694      selectModuleSource(M, ModuleName, ModuleFilename, BuiltModules, HS);
1695  if (Source == MS_ModuleNotFound) {
1696    // We can't find a module, error out here.
1697    getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1698        << ModuleName << SourceRange(ImportLoc, ModuleNameLoc);
1699    ModuleBuildFailed = true;
1700    // FIXME: Why is this not cached?
1701    return ModuleLoadResult::OtherUncachedFailure;
1702  }
1703  if (ModuleFilename.empty()) {
1704    if (M && M->HasIncompatibleModuleFile) {
1705      // We tried and failed to load a module file for this module. Fall
1706      // back to textual inclusion for its headers.
1707      return ModuleLoadResult::ConfigMismatch;
1708    }
1709
1710    getDiagnostics().Report(ModuleNameLoc, diag::err_module_build_disabled)
1711        << ModuleName;
1712    ModuleBuildFailed = true;
1713    // FIXME: Why is this not cached?
1714    return ModuleLoadResult::OtherUncachedFailure;
1715  }
1716
1717  // Create an ASTReader on demand.
1718  if (!getASTReader())
1719    createASTReader();
1720
1721  // Time how long it takes to load the module.
1722  llvm::Timer Timer;
1723  if (FrontendTimerGroup)
1724    Timer.init("loading." + ModuleFilename, "Loading " + ModuleFilename,
1725               *FrontendTimerGroup);
1726  llvm::TimeRegion TimeLoading(FrontendTimerGroup ? &Timer : nullptr);
1727  llvm::TimeTraceScope TimeScope("Module Load", ModuleName);
1728
1729  // Try to load the module file. If we are not trying to load from the
1730  // module cache, we don't know how to rebuild modules.
1731  unsigned ARRFlags = Source == MS_ModuleCache
1732                          ? ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing
1733                          : Source == MS_PrebuiltModulePath
1734                                ? 0
1735                                : ASTReader::ARR_ConfigurationMismatch;
1736  switch (getASTReader()->ReadAST(ModuleFilename,
1737                                  Source == MS_PrebuiltModulePath
1738                                      ? serialization::MK_PrebuiltModule
1739                                      : Source == MS_ModuleBuildPragma
1740                                            ? serialization::MK_ExplicitModule
1741                                            : serialization::MK_ImplicitModule,
1742                                  ImportLoc, ARRFlags)) {
1743  case ASTReader::Success: {
1744    if (M)
1745      return M;
1746    assert(Source != MS_ModuleCache &&
1747           "missing module, but file loaded from cache");
1748
1749    // A prebuilt module is indexed as a ModuleFile; the Module does not exist
1750    // until the first call to ReadAST.  Look it up now.
1751    M = HS.lookupModule(ModuleName, true, !IsInclusionDirective);
1752
1753    // Check whether M refers to the file in the prebuilt module path.
1754    if (M && M->getASTFile())
1755      if (auto ModuleFile = FileMgr->getFile(ModuleFilename))
1756        if (*ModuleFile == M->getASTFile())
1757          return M;
1758
1759    ModuleBuildFailed = true;
1760    getDiagnostics().Report(ModuleNameLoc, diag::err_module_prebuilt)
1761        << ModuleName;
1762    return ModuleLoadResult();
1763  }
1764
1765  case ASTReader::OutOfDate:
1766  case ASTReader::Missing:
1767    // The most interesting case.
1768    break;
1769
1770  case ASTReader::ConfigurationMismatch:
1771    if (Source == MS_PrebuiltModulePath)
1772      // FIXME: We shouldn't be setting HadFatalFailure below if we only
1773      // produce a warning here!
1774      getDiagnostics().Report(SourceLocation(),
1775                              diag::warn_module_config_mismatch)
1776          << ModuleFilename;
1777    // Fall through to error out.
1778    LLVM_FALLTHROUGH;
1779  case ASTReader::VersionMismatch:
1780  case ASTReader::HadErrors:
1781    // FIXME: Should this set ModuleBuildFailed = true?
1782    ModuleLoader::HadFatalFailure = true;
1783    // FIXME: The ASTReader will already have complained, but can we shoehorn
1784    // that diagnostic information into a more useful form?
1785    return ModuleLoadResult();
1786
1787  case ASTReader::Failure:
1788    // FIXME: Should this set ModuleBuildFailed = true?
1789    ModuleLoader::HadFatalFailure = true;
1790    return ModuleLoadResult();
1791  }
1792
1793  // ReadAST returned Missing or OutOfDate.
1794  if (Source != MS_ModuleCache) {
1795    // We don't know the desired configuration for this module and don't
1796    // necessarily even have a module map. Since ReadAST already produces
1797    // diagnostics for these two cases, we simply error out here.
1798    ModuleBuildFailed = true;
1799    return ModuleLoadResult();
1800  }
1801
1802  // The module file is missing or out-of-date. Build it.
1803  assert(M && "missing module, but trying to compile for cache");
1804
1805  // Check whether there is a cycle in the module graph.
1806  ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1807  ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1808  for (; Pos != PosEnd; ++Pos) {
1809    if (Pos->first == ModuleName)
1810      break;
1811  }
1812
1813  if (Pos != PosEnd) {
1814    SmallString<256> CyclePath;
1815    for (; Pos != PosEnd; ++Pos) {
1816      CyclePath += Pos->first;
1817      CyclePath += " -> ";
1818    }
1819    CyclePath += ModuleName;
1820
1821    getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1822        << ModuleName << CyclePath;
1823    // FIXME: Should this set ModuleBuildFailed = true?
1824    // FIXME: Why is this not cached?
1825    return ModuleLoadResult::OtherUncachedFailure;
1826  }
1827
1828  // Check whether we have already attempted to build this module (but
1829  // failed).
1830  if (getPreprocessorOpts().FailedModules &&
1831      getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1832    getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1833        << ModuleName << SourceRange(ImportLoc, ModuleNameLoc);
1834    ModuleBuildFailed = true;
1835    // FIXME: Why is this not cached?
1836    return ModuleLoadResult::OtherUncachedFailure;
1837  }
1838
1839  // Try to compile and then read the AST.
1840  if (!compileModuleAndReadAST(*this, ImportLoc, ModuleNameLoc, M,
1841                               ModuleFilename)) {
1842    assert(getDiagnostics().hasErrorOccurred() &&
1843           "undiagnosed error in compileModuleAndReadAST");
1844    if (getPreprocessorOpts().FailedModules)
1845      getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1846    ModuleBuildFailed = true;
1847    // FIXME: Why is this not cached?
1848    return ModuleLoadResult::OtherUncachedFailure;
1849  }
1850
1851  // Okay, we've rebuilt and now loaded the module.
1852  return M;
1853}
1854
1855ModuleLoadResult
1856CompilerInstance::loadModule(SourceLocation ImportLoc,
1857                             ModuleIdPath Path,
1858                             Module::NameVisibilityKind Visibility,
1859                             bool IsInclusionDirective) {
1860  // Determine what file we're searching from.
1861  StringRef ModuleName = Path[0].first->getName();
1862  SourceLocation ModuleNameLoc = Path[0].second;
1863
1864  // If we've already handled this import, just return the cached result.
1865  // This one-element cache is important to eliminate redundant diagnostics
1866  // when both the preprocessor and parser see the same import declaration.
1867  if (ImportLoc.isValid() && LastModuleImportLoc == ImportLoc) {
1868    // Make the named module visible.
1869    if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1870      TheASTReader->makeModuleVisible(LastModuleImportResult, Visibility,
1871                                      ImportLoc);
1872    return LastModuleImportResult;
1873  }
1874
1875  // If we don't already have information on this module, load the module now.
1876  Module *Module = nullptr;
1877  ModuleMap &MM = getPreprocessor().getHeaderSearchInfo().getModuleMap();
1878  if (auto MaybeModule = MM.getCachedModuleLoad(*Path[0].first)) {
1879    // Use the cached result, which may be nullptr.
1880    Module = *MaybeModule;
1881  } else if (ModuleName == getLangOpts().CurrentModule) {
1882    // This is the module we're building.
1883    Module = PP->getHeaderSearchInfo().lookupModule(
1884        ModuleName, /*AllowSearch*/ true,
1885        /*AllowExtraModuleMapSearch*/ !IsInclusionDirective);
1886    /// FIXME: perhaps we should (a) look for a module using the module name
1887    //  to file map (PrebuiltModuleFiles) and (b) diagnose if still not found?
1888    //if (Module == nullptr) {
1889    //  getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1890    //    << ModuleName;
1891    //  ModuleBuildFailed = true;
1892    //  return ModuleLoadResult();
1893    //}
1894    MM.cacheModuleLoad(*Path[0].first, Module);
1895  } else {
1896    ModuleLoadResult Result = findOrCompileModuleAndReadAST(
1897        ModuleName, ImportLoc, ModuleNameLoc, IsInclusionDirective);
1898    // FIXME: Can we pull 'ModuleBuildFailed = true' out of the return
1899    // sequences for findOrCompileModuleAndReadAST and do it here (as long as
1900    // the result is not a config mismatch)?  See FIXMEs there.
1901    if (!Result.isNormal())
1902      return Result;
1903    Module = Result;
1904    MM.cacheModuleLoad(*Path[0].first, Module);
1905    if (!Module)
1906      return Module;
1907  }
1908
1909  // If we never found the module, fail.  Otherwise, verify the module and link
1910  // it up.
1911  if (!Module)
1912    return ModuleLoadResult();
1913
1914  // Verify that the rest of the module path actually corresponds to
1915  // a submodule.
1916  bool MapPrivateSubModToTopLevel = false;
1917  if (Path.size() > 1) {
1918    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1919      StringRef Name = Path[I].first->getName();
1920      clang::Module *Sub = Module->findSubmodule(Name);
1921
1922      // If the user is requesting Foo.Private and it doesn't exist, try to
1923      // match Foo_Private and emit a warning asking for the user to write
1924      // @import Foo_Private instead. FIXME: remove this when existing clients
1925      // migrate off of Foo.Private syntax.
1926      if (!Sub && PP->getLangOpts().ImplicitModules && Name == "Private" &&
1927          Module == Module->getTopLevelModule()) {
1928        SmallString<128> PrivateModule(Module->Name);
1929        PrivateModule.append("_Private");
1930
1931        SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> PrivPath;
1932        auto &II = PP->getIdentifierTable().get(
1933            PrivateModule, PP->getIdentifierInfo(Module->Name)->getTokenID());
1934        PrivPath.push_back(std::make_pair(&II, Path[0].second));
1935
1936        if (PP->getHeaderSearchInfo().lookupModule(PrivateModule, true,
1937                                                   !IsInclusionDirective))
1938          Sub =
1939              loadModule(ImportLoc, PrivPath, Visibility, IsInclusionDirective);
1940        if (Sub) {
1941          MapPrivateSubModToTopLevel = true;
1942          if (!getDiagnostics().isIgnored(
1943                  diag::warn_no_priv_submodule_use_toplevel, ImportLoc)) {
1944            getDiagnostics().Report(Path[I].second,
1945                                    diag::warn_no_priv_submodule_use_toplevel)
1946                << Path[I].first << Module->getFullModuleName() << PrivateModule
1947                << SourceRange(Path[0].second, Path[I].second)
1948                << FixItHint::CreateReplacement(SourceRange(Path[0].second),
1949                                                PrivateModule);
1950            getDiagnostics().Report(Sub->DefinitionLoc,
1951                                    diag::note_private_top_level_defined);
1952          }
1953        }
1954      }
1955
1956      if (!Sub) {
1957        // Attempt to perform typo correction to find a module name that works.
1958        SmallVector<StringRef, 2> Best;
1959        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1960
1961        for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1962                                            JEnd = Module->submodule_end();
1963             J != JEnd; ++J) {
1964          unsigned ED = Name.edit_distance((*J)->Name,
1965                                           /*AllowReplacements=*/true,
1966                                           BestEditDistance);
1967          if (ED <= BestEditDistance) {
1968            if (ED < BestEditDistance) {
1969              Best.clear();
1970              BestEditDistance = ED;
1971            }
1972
1973            Best.push_back((*J)->Name);
1974          }
1975        }
1976
1977        // If there was a clear winner, user it.
1978        if (Best.size() == 1) {
1979          getDiagnostics().Report(Path[I].second,
1980                                  diag::err_no_submodule_suggest)
1981            << Path[I].first << Module->getFullModuleName() << Best[0]
1982            << SourceRange(Path[0].second, Path[I-1].second)
1983            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1984                                            Best[0]);
1985
1986          Sub = Module->findSubmodule(Best[0]);
1987        }
1988      }
1989
1990      if (!Sub) {
1991        // No submodule by this name. Complain, and don't look for further
1992        // submodules.
1993        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1994          << Path[I].first << Module->getFullModuleName()
1995          << SourceRange(Path[0].second, Path[I-1].second);
1996        break;
1997      }
1998
1999      Module = Sub;
2000    }
2001  }
2002
2003  // Make the named module visible, if it's not already part of the module
2004  // we are parsing.
2005  if (ModuleName != getLangOpts().CurrentModule) {
2006    if (!Module->IsFromModuleFile && !MapPrivateSubModToTopLevel) {
2007      // We have an umbrella header or directory that doesn't actually include
2008      // all of the headers within the directory it covers. Complain about
2009      // this missing submodule and recover by forgetting that we ever saw
2010      // this submodule.
2011      // FIXME: Should we detect this at module load time? It seems fairly
2012      // expensive (and rare).
2013      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
2014        << Module->getFullModuleName()
2015        << SourceRange(Path.front().second, Path.back().second);
2016
2017      return ModuleLoadResult::MissingExpected;
2018    }
2019
2020    // Check whether this module is available.
2021    if (Preprocessor::checkModuleIsAvailable(getLangOpts(), getTarget(),
2022                                             getDiagnostics(), Module)) {
2023      getDiagnostics().Report(ImportLoc, diag::note_module_import_here)
2024        << SourceRange(Path.front().second, Path.back().second);
2025      LastModuleImportLoc = ImportLoc;
2026      LastModuleImportResult = ModuleLoadResult();
2027      return ModuleLoadResult();
2028    }
2029
2030    TheASTReader->makeModuleVisible(Module, Visibility, ImportLoc);
2031  }
2032
2033  // Check for any configuration macros that have changed.
2034  clang::Module *TopModule = Module->getTopLevelModule();
2035  for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
2036    checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
2037                     Module, ImportLoc);
2038  }
2039
2040  // Resolve any remaining module using export_as for this one.
2041  getPreprocessor()
2042      .getHeaderSearchInfo()
2043      .getModuleMap()
2044      .resolveLinkAsDependencies(TopModule);
2045
2046  LastModuleImportLoc = ImportLoc;
2047  LastModuleImportResult = ModuleLoadResult(Module);
2048  return LastModuleImportResult;
2049}
2050
2051void CompilerInstance::createModuleFromSource(SourceLocation ImportLoc,
2052                                              StringRef ModuleName,
2053                                              StringRef Source) {
2054  // Avoid creating filenames with special characters.
2055  SmallString<128> CleanModuleName(ModuleName);
2056  for (auto &C : CleanModuleName)
2057    if (!isAlphanumeric(C))
2058      C = '_';
2059
2060  // FIXME: Using a randomized filename here means that our intermediate .pcm
2061  // output is nondeterministic (as .pcm files refer to each other by name).
2062  // Can this affect the output in any way?
2063  SmallString<128> ModuleFileName;
2064  if (std::error_code EC = llvm::sys::fs::createTemporaryFile(
2065          CleanModuleName, "pcm", ModuleFileName)) {
2066    getDiagnostics().Report(ImportLoc, diag::err_fe_unable_to_open_output)
2067        << ModuleFileName << EC.message();
2068    return;
2069  }
2070  std::string ModuleMapFileName = (CleanModuleName + ".map").str();
2071
2072  FrontendInputFile Input(
2073      ModuleMapFileName,
2074      InputKind(getLanguageFromOptions(*Invocation->getLangOpts()),
2075                InputKind::ModuleMap, /*Preprocessed*/true));
2076
2077  std::string NullTerminatedSource(Source.str());
2078
2079  auto PreBuildStep = [&](CompilerInstance &Other) {
2080    // Create a virtual file containing our desired source.
2081    // FIXME: We shouldn't need to do this.
2082    const FileEntry *ModuleMapFile = Other.getFileManager().getVirtualFile(
2083        ModuleMapFileName, NullTerminatedSource.size(), 0);
2084    Other.getSourceManager().overrideFileContents(
2085        ModuleMapFile,
2086        llvm::MemoryBuffer::getMemBuffer(NullTerminatedSource.c_str()));
2087
2088    Other.BuiltModules = std::move(BuiltModules);
2089    Other.DeleteBuiltModules = false;
2090  };
2091
2092  auto PostBuildStep = [this](CompilerInstance &Other) {
2093    BuiltModules = std::move(Other.BuiltModules);
2094  };
2095
2096  // Build the module, inheriting any modules that we've built locally.
2097  if (compileModuleImpl(*this, ImportLoc, ModuleName, Input, StringRef(),
2098                        ModuleFileName, PreBuildStep, PostBuildStep)) {
2099    BuiltModules[std::string(ModuleName)] = std::string(ModuleFileName.str());
2100    llvm::sys::RemoveFileOnSignal(ModuleFileName);
2101  }
2102}
2103
2104void CompilerInstance::makeModuleVisible(Module *Mod,
2105                                         Module::NameVisibilityKind Visibility,
2106                                         SourceLocation ImportLoc) {
2107  if (!TheASTReader)
2108    createASTReader();
2109  if (!TheASTReader)
2110    return;
2111
2112  TheASTReader->makeModuleVisible(Mod, Visibility, ImportLoc);
2113}
2114
2115GlobalModuleIndex *CompilerInstance::loadGlobalModuleIndex(
2116    SourceLocation TriggerLoc) {
2117  if (getPreprocessor().getHeaderSearchInfo().getModuleCachePath().empty())
2118    return nullptr;
2119  if (!TheASTReader)
2120    createASTReader();
2121  // Can't do anything if we don't have the module manager.
2122  if (!TheASTReader)
2123    return nullptr;
2124  // Get an existing global index.  This loads it if not already
2125  // loaded.
2126  TheASTReader->loadGlobalIndex();
2127  GlobalModuleIndex *GlobalIndex = TheASTReader->getGlobalIndex();
2128  // If the global index doesn't exist, create it.
2129  if (!GlobalIndex && shouldBuildGlobalModuleIndex() && hasFileManager() &&
2130      hasPreprocessor()) {
2131    llvm::sys::fs::create_directories(
2132      getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
2133    if (llvm::Error Err = GlobalModuleIndex::writeIndex(
2134            getFileManager(), getPCHContainerReader(),
2135            getPreprocessor().getHeaderSearchInfo().getModuleCachePath())) {
2136      // FIXME this drops the error on the floor. This code is only used for
2137      // typo correction and drops more than just this one source of errors
2138      // (such as the directory creation failure above). It should handle the
2139      // error.
2140      consumeError(std::move(Err));
2141      return nullptr;
2142    }
2143    TheASTReader->resetForReload();
2144    TheASTReader->loadGlobalIndex();
2145    GlobalIndex = TheASTReader->getGlobalIndex();
2146  }
2147  // For finding modules needing to be imported for fixit messages,
2148  // we need to make the global index cover all modules, so we do that here.
2149  if (!HaveFullGlobalModuleIndex && GlobalIndex && !buildingModule()) {
2150    ModuleMap &MMap = getPreprocessor().getHeaderSearchInfo().getModuleMap();
2151    bool RecreateIndex = false;
2152    for (ModuleMap::module_iterator I = MMap.module_begin(),
2153        E = MMap.module_end(); I != E; ++I) {
2154      Module *TheModule = I->second;
2155      const FileEntry *Entry = TheModule->getASTFile();
2156      if (!Entry) {
2157        SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
2158        Path.push_back(std::make_pair(
2159            getPreprocessor().getIdentifierInfo(TheModule->Name), TriggerLoc));
2160        std::reverse(Path.begin(), Path.end());
2161        // Load a module as hidden.  This also adds it to the global index.
2162        loadModule(TheModule->DefinitionLoc, Path, Module::Hidden, false);
2163        RecreateIndex = true;
2164      }
2165    }
2166    if (RecreateIndex) {
2167      if (llvm::Error Err = GlobalModuleIndex::writeIndex(
2168              getFileManager(), getPCHContainerReader(),
2169              getPreprocessor().getHeaderSearchInfo().getModuleCachePath())) {
2170        // FIXME As above, this drops the error on the floor.
2171        consumeError(std::move(Err));
2172        return nullptr;
2173      }
2174      TheASTReader->resetForReload();
2175      TheASTReader->loadGlobalIndex();
2176      GlobalIndex = TheASTReader->getGlobalIndex();
2177    }
2178    HaveFullGlobalModuleIndex = true;
2179  }
2180  return GlobalIndex;
2181}
2182
2183// Check global module index for missing imports.
2184bool
2185CompilerInstance::lookupMissingImports(StringRef Name,
2186                                       SourceLocation TriggerLoc) {
2187  // Look for the symbol in non-imported modules, but only if an error
2188  // actually occurred.
2189  if (!buildingModule()) {
2190    // Load global module index, or retrieve a previously loaded one.
2191    GlobalModuleIndex *GlobalIndex = loadGlobalModuleIndex(
2192      TriggerLoc);
2193
2194    // Only if we have a global index.
2195    if (GlobalIndex) {
2196      GlobalModuleIndex::HitSet FoundModules;
2197
2198      // Find the modules that reference the identifier.
2199      // Note that this only finds top-level modules.
2200      // We'll let diagnoseTypo find the actual declaration module.
2201      if (GlobalIndex->lookupIdentifier(Name, FoundModules))
2202        return true;
2203    }
2204  }
2205
2206  return false;
2207}
2208void CompilerInstance::resetAndLeakSema() { llvm::BuryPointer(takeSema()); }
2209
2210void CompilerInstance::setExternalSemaSource(
2211    IntrusiveRefCntPtr<ExternalSemaSource> ESS) {
2212  ExternalSemaSrc = std::move(ESS);
2213}
2214