CompilerInstance.cpp revision 1.1.1.1 
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          (ModuleManager && ModuleManager->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
100void CompilerInstance::setFileManager(FileManager *Value) {
101  FileMgr = Value;
102}
103
104void CompilerInstance::setSourceManager(SourceManager *Value) {
105  SourceMgr = Value;
106}
107
108void CompilerInstance::setPreprocessor(std::shared_ptr<Preprocessor> Value) {
109  PP = std::move(Value);
110}
111
112void CompilerInstance::setASTContext(ASTContext *Value) {
113  Context = Value;
114
115  if (Context && Consumer)
116    getASTConsumer().Initialize(getASTContext());
117}
118
119void CompilerInstance::setSema(Sema *S) {
120  TheSema.reset(S);
121}
122
123void CompilerInstance::setASTConsumer(std::unique_ptr<ASTConsumer> Value) {
124  Consumer = std::move(Value);
125
126  if (Context && Consumer)
127    getASTConsumer().Initialize(getASTContext());
128}
129
130void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
131  CompletionConsumer.reset(Value);
132}
133
134std::unique_ptr<Sema> CompilerInstance::takeSema() {
135  return std::move(TheSema);
136}
137
138IntrusiveRefCntPtr<ASTReader> CompilerInstance::getModuleManager() const {
139  return ModuleManager;
140}
141void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
142  assert(ModuleCache.get() == &Reader->getModuleManager().getModuleCache() &&
143         "Expected ASTReader to use the same PCM cache");
144  ModuleManager = std::move(Reader);
145}
146
147std::shared_ptr<ModuleDependencyCollector>
148CompilerInstance::getModuleDepCollector() const {
149  return ModuleDepCollector;
150}
151
152void CompilerInstance::setModuleDepCollector(
153    std::shared_ptr<ModuleDependencyCollector> Collector) {
154  ModuleDepCollector = std::move(Collector);
155}
156
157static void collectHeaderMaps(const HeaderSearch &HS,
158                              std::shared_ptr<ModuleDependencyCollector> MDC) {
159  SmallVector<std::string, 4> HeaderMapFileNames;
160  HS.getHeaderMapFileNames(HeaderMapFileNames);
161  for (auto &Name : HeaderMapFileNames)
162    MDC->addFile(Name);
163}
164
165static void collectIncludePCH(CompilerInstance &CI,
166                              std::shared_ptr<ModuleDependencyCollector> MDC) {
167  const PreprocessorOptions &PPOpts = CI.getPreprocessorOpts();
168  if (PPOpts.ImplicitPCHInclude.empty())
169    return;
170
171  StringRef PCHInclude = PPOpts.ImplicitPCHInclude;
172  FileManager &FileMgr = CI.getFileManager();
173  auto PCHDir = FileMgr.getDirectory(PCHInclude);
174  if (!PCHDir) {
175    MDC->addFile(PCHInclude);
176    return;
177  }
178
179  std::error_code EC;
180  SmallString<128> DirNative;
181  llvm::sys::path::native((*PCHDir)->getName(), DirNative);
182  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
183  SimpleASTReaderListener Validator(CI.getPreprocessor());
184  for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC), DirEnd;
185       Dir != DirEnd && !EC; Dir.increment(EC)) {
186    // Check whether this is an AST file. ASTReader::isAcceptableASTFile is not
187    // used here since we're not interested in validating the PCH at this time,
188    // but only to check whether this is a file containing an AST.
189    if (!ASTReader::readASTFileControlBlock(
190            Dir->path(), FileMgr, CI.getPCHContainerReader(),
191            /*FindModuleFileExtensions=*/false, Validator,
192            /*ValidateDiagnosticOptions=*/false))
193      MDC->addFile(Dir->path());
194  }
195}
196
197static void collectVFSEntries(CompilerInstance &CI,
198                              std::shared_ptr<ModuleDependencyCollector> MDC) {
199  if (CI.getHeaderSearchOpts().VFSOverlayFiles.empty())
200    return;
201
202  // Collect all VFS found.
203  SmallVector<llvm::vfs::YAMLVFSEntry, 16> VFSEntries;
204  for (const std::string &VFSFile : CI.getHeaderSearchOpts().VFSOverlayFiles) {
205    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buffer =
206        llvm::MemoryBuffer::getFile(VFSFile);
207    if (!Buffer)
208      return;
209    llvm::vfs::collectVFSFromYAML(std::move(Buffer.get()),
210                                  /*DiagHandler*/ nullptr, VFSFile, VFSEntries);
211  }
212
213  for (auto &E : VFSEntries)
214    MDC->addFile(E.VPath, E.RPath);
215}
216
217// Diagnostics
218static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
219                               const CodeGenOptions *CodeGenOpts,
220                               DiagnosticsEngine &Diags) {
221  std::error_code EC;
222  std::unique_ptr<raw_ostream> StreamOwner;
223  raw_ostream *OS = &llvm::errs();
224  if (DiagOpts->DiagnosticLogFile != "-") {
225    // Create the output stream.
226    auto FileOS = std::make_unique<llvm::raw_fd_ostream>(
227        DiagOpts->DiagnosticLogFile, EC,
228        llvm::sys::fs::OF_Append | llvm::sys::fs::OF_Text);
229    if (EC) {
230      Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
231          << DiagOpts->DiagnosticLogFile << EC.message();
232    } else {
233      FileOS->SetUnbuffered();
234      OS = FileOS.get();
235      StreamOwner = std::move(FileOS);
236    }
237  }
238
239  // Chain in the diagnostic client which will log the diagnostics.
240  auto Logger = std::make_unique<LogDiagnosticPrinter>(*OS, DiagOpts,
241                                                        std::move(StreamOwner));
242  if (CodeGenOpts)
243    Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
244  if (Diags.ownsClient()) {
245    Diags.setClient(
246        new ChainedDiagnosticConsumer(Diags.takeClient(), std::move(Logger)));
247  } else {
248    Diags.setClient(
249        new ChainedDiagnosticConsumer(Diags.getClient(), std::move(Logger)));
250  }
251}
252
253static void SetupSerializedDiagnostics(DiagnosticOptions *DiagOpts,
254                                       DiagnosticsEngine &Diags,
255                                       StringRef OutputFile) {
256  auto SerializedConsumer =
257      clang::serialized_diags::create(OutputFile, DiagOpts);
258
259  if (Diags.ownsClient()) {
260    Diags.setClient(new ChainedDiagnosticConsumer(
261        Diags.takeClient(), std::move(SerializedConsumer)));
262  } else {
263    Diags.setClient(new ChainedDiagnosticConsumer(
264        Diags.getClient(), std::move(SerializedConsumer)));
265  }
266}
267
268void CompilerInstance::createDiagnostics(DiagnosticConsumer *Client,
269                                         bool ShouldOwnClient) {
270  Diagnostics = createDiagnostics(&getDiagnosticOpts(), Client,
271                                  ShouldOwnClient, &getCodeGenOpts());
272}
273
274IntrusiveRefCntPtr<DiagnosticsEngine>
275CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
276                                    DiagnosticConsumer *Client,
277                                    bool ShouldOwnClient,
278                                    const CodeGenOptions *CodeGenOpts) {
279  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
280  IntrusiveRefCntPtr<DiagnosticsEngine>
281      Diags(new DiagnosticsEngine(DiagID, Opts));
282
283  // Create the diagnostic client for reporting errors or for
284  // implementing -verify.
285  if (Client) {
286    Diags->setClient(Client, ShouldOwnClient);
287  } else
288    Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
289
290  // Chain in -verify checker, if requested.
291  if (Opts->VerifyDiagnostics)
292    Diags->setClient(new VerifyDiagnosticConsumer(*Diags));
293
294  // Chain in -diagnostic-log-file dumper, if requested.
295  if (!Opts->DiagnosticLogFile.empty())
296    SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
297
298  if (!Opts->DiagnosticSerializationFile.empty())
299    SetupSerializedDiagnostics(Opts, *Diags,
300                               Opts->DiagnosticSerializationFile);
301
302  // Configure our handling of diagnostics.
303  ProcessWarningOptions(*Diags, *Opts);
304
305  return Diags;
306}
307
308// File Manager
309
310FileManager *CompilerInstance::createFileManager(
311    IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
312  if (!VFS)
313    VFS = FileMgr ? &FileMgr->getVirtualFileSystem()
314                  : createVFSFromCompilerInvocation(getInvocation(),
315                                                    getDiagnostics());
316  assert(VFS && "FileManager has no VFS?");
317  FileMgr = new FileManager(getFileSystemOpts(), std::move(VFS));
318  return FileMgr.get();
319}
320
321// Source Manager
322
323void CompilerInstance::createSourceManager(FileManager &FileMgr) {
324  SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
325}
326
327// Initialize the remapping of files to alternative contents, e.g.,
328// those specified through other files.
329static void InitializeFileRemapping(DiagnosticsEngine &Diags,
330                                    SourceManager &SourceMgr,
331                                    FileManager &FileMgr,
332                                    const PreprocessorOptions &InitOpts) {
333  // Remap files in the source manager (with buffers).
334  for (const auto &RB : InitOpts.RemappedFileBuffers) {
335    // Create the file entry for the file that we're mapping from.
336    const FileEntry *FromFile =
337        FileMgr.getVirtualFile(RB.first, RB.second->getBufferSize(), 0);
338    if (!FromFile) {
339      Diags.Report(diag::err_fe_remap_missing_from_file) << RB.first;
340      if (!InitOpts.RetainRemappedFileBuffers)
341        delete RB.second;
342      continue;
343    }
344
345    // Override the contents of the "from" file with the contents of
346    // the "to" file.
347    SourceMgr.overrideFileContents(FromFile, RB.second,
348                                   InitOpts.RetainRemappedFileBuffers);
349  }
350
351  // Remap files in the source manager (with other files).
352  for (const auto &RF : InitOpts.RemappedFiles) {
353    // Find the file that we're mapping to.
354    auto ToFile = FileMgr.getFile(RF.second);
355    if (!ToFile) {
356      Diags.Report(diag::err_fe_remap_missing_to_file) << RF.first << RF.second;
357      continue;
358    }
359
360    // Create the file entry for the file that we're mapping from.
361    const FileEntry *FromFile =
362        FileMgr.getVirtualFile(RF.first, (*ToFile)->getSize(), 0);
363    if (!FromFile) {
364      Diags.Report(diag::err_fe_remap_missing_from_file) << RF.first;
365      continue;
366    }
367
368    // Override the contents of the "from" file with the contents of
369    // the "to" file.
370    SourceMgr.overrideFileContents(FromFile, *ToFile);
371  }
372
373  SourceMgr.setOverridenFilesKeepOriginalName(
374      InitOpts.RemappedFilesKeepOriginalName);
375}
376
377// Preprocessor
378
379void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
380  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
381
382  // The module manager holds a reference to the old preprocessor (if any).
383  ModuleManager.reset();
384
385  // Create the Preprocessor.
386  HeaderSearch *HeaderInfo =
387      new HeaderSearch(getHeaderSearchOptsPtr(), getSourceManager(),
388                       getDiagnostics(), getLangOpts(), &getTarget());
389  PP = std::make_shared<Preprocessor>(Invocation->getPreprocessorOptsPtr(),
390                                      getDiagnostics(), getLangOpts(),
391                                      getSourceManager(), *HeaderInfo, *this,
392                                      /*IdentifierInfoLookup=*/nullptr,
393                                      /*OwnsHeaderSearch=*/true, TUKind);
394  getTarget().adjust(getLangOpts());
395  PP->Initialize(getTarget(), getAuxTarget());
396
397  if (PPOpts.DetailedRecord)
398    PP->createPreprocessingRecord();
399
400  // Apply remappings to the source manager.
401  InitializeFileRemapping(PP->getDiagnostics(), PP->getSourceManager(),
402                          PP->getFileManager(), PPOpts);
403
404  // Predefine macros and configure the preprocessor.
405  InitializePreprocessor(*PP, PPOpts, getPCHContainerReader(),
406                         getFrontendOpts());
407
408  // Initialize the header search object.  In CUDA compilations, we use the aux
409  // triple (the host triple) to initialize our header search, since we need to
410  // find the host headers in order to compile the CUDA code.
411  const llvm::Triple *HeaderSearchTriple = &PP->getTargetInfo().getTriple();
412  if (PP->getTargetInfo().getTriple().getOS() == llvm::Triple::CUDA &&
413      PP->getAuxTargetInfo())
414    HeaderSearchTriple = &PP->getAuxTargetInfo()->getTriple();
415
416  ApplyHeaderSearchOptions(PP->getHeaderSearchInfo(), getHeaderSearchOpts(),
417                           PP->getLangOpts(), *HeaderSearchTriple);
418
419  PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
420
421  if (PP->getLangOpts().Modules && PP->getLangOpts().ImplicitModules)
422    PP->getHeaderSearchInfo().setModuleCachePath(getSpecificModuleCachePath());
423
424  // Handle generating dependencies, if requested.
425  const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
426  if (!DepOpts.OutputFile.empty())
427    addDependencyCollector(std::make_shared<DependencyFileGenerator>(DepOpts));
428  if (!DepOpts.DOTOutputFile.empty())
429    AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
430                             getHeaderSearchOpts().Sysroot);
431
432  // If we don't have a collector, but we are collecting module dependencies,
433  // then we're the top level compiler instance and need to create one.
434  if (!ModuleDepCollector && !DepOpts.ModuleDependencyOutputDir.empty()) {
435    ModuleDepCollector = std::make_shared<ModuleDependencyCollector>(
436        DepOpts.ModuleDependencyOutputDir);
437  }
438
439  // If there is a module dep collector, register with other dep collectors
440  // and also (a) collect header maps and (b) TODO: input vfs overlay files.
441  if (ModuleDepCollector) {
442    addDependencyCollector(ModuleDepCollector);
443    collectHeaderMaps(PP->getHeaderSearchInfo(), ModuleDepCollector);
444    collectIncludePCH(*this, ModuleDepCollector);
445    collectVFSEntries(*this, ModuleDepCollector);
446  }
447
448  for (auto &Listener : DependencyCollectors)
449    Listener->attachToPreprocessor(*PP);
450
451  // Handle generating header include information, if requested.
452  if (DepOpts.ShowHeaderIncludes)
453    AttachHeaderIncludeGen(*PP, DepOpts);
454  if (!DepOpts.HeaderIncludeOutputFile.empty()) {
455    StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
456    if (OutputPath == "-")
457      OutputPath = "";
458    AttachHeaderIncludeGen(*PP, DepOpts,
459                           /*ShowAllHeaders=*/true, OutputPath,
460                           /*ShowDepth=*/false);
461  }
462
463  if (DepOpts.ShowIncludesDest != ShowIncludesDestination::None) {
464    AttachHeaderIncludeGen(*PP, DepOpts,
465                           /*ShowAllHeaders=*/true, /*OutputPath=*/"",
466                           /*ShowDepth=*/true, /*MSStyle=*/true);
467  }
468}
469
470std::string CompilerInstance::getSpecificModuleCachePath() {
471  // Set up the module path, including the hash for the
472  // module-creation options.
473  SmallString<256> SpecificModuleCache(getHeaderSearchOpts().ModuleCachePath);
474  if (!SpecificModuleCache.empty() && !getHeaderSearchOpts().DisableModuleHash)
475    llvm::sys::path::append(SpecificModuleCache,
476                            getInvocation().getModuleHash());
477  return SpecificModuleCache.str();
478}
479
480// ASTContext
481
482void CompilerInstance::createASTContext() {
483  Preprocessor &PP = getPreprocessor();
484  auto *Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
485                                 PP.getIdentifierTable(), PP.getSelectorTable(),
486                                 PP.getBuiltinInfo());
487  Context->InitBuiltinTypes(getTarget(), getAuxTarget());
488  setASTContext(Context);
489}
490
491// ExternalASTSource
492
493void CompilerInstance::createPCHExternalASTSource(
494    StringRef Path, bool DisablePCHValidation, bool AllowPCHWithCompilerErrors,
495    void *DeserializationListener, bool OwnDeserializationListener) {
496  bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
497  ModuleManager = createPCHExternalASTSource(
498      Path, getHeaderSearchOpts().Sysroot, DisablePCHValidation,
499      AllowPCHWithCompilerErrors, getPreprocessor(), getModuleCache(),
500      getASTContext(), getPCHContainerReader(),
501      getFrontendOpts().ModuleFileExtensions, DependencyCollectors,
502      DeserializationListener, OwnDeserializationListener, Preamble,
503      getFrontendOpts().UseGlobalModuleIndex);
504}
505
506IntrusiveRefCntPtr<ASTReader> CompilerInstance::createPCHExternalASTSource(
507    StringRef Path, StringRef Sysroot, bool DisablePCHValidation,
508    bool AllowPCHWithCompilerErrors, Preprocessor &PP,
509    InMemoryModuleCache &ModuleCache, ASTContext &Context,
510    const PCHContainerReader &PCHContainerRdr,
511    ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
512    ArrayRef<std::shared_ptr<DependencyCollector>> DependencyCollectors,
513    void *DeserializationListener, bool OwnDeserializationListener,
514    bool Preamble, bool UseGlobalModuleIndex) {
515  HeaderSearchOptions &HSOpts = PP.getHeaderSearchInfo().getHeaderSearchOpts();
516
517  IntrusiveRefCntPtr<ASTReader> Reader(new ASTReader(
518      PP, ModuleCache, &Context, PCHContainerRdr, Extensions,
519      Sysroot.empty() ? "" : Sysroot.data(), DisablePCHValidation,
520      AllowPCHWithCompilerErrors, /*AllowConfigurationMismatch*/ false,
521      HSOpts.ModulesValidateSystemHeaders, HSOpts.ValidateASTInputFilesContent,
522      UseGlobalModuleIndex));
523
524  // We need the external source to be set up before we read the AST, because
525  // eagerly-deserialized declarations may use it.
526  Context.setExternalSource(Reader.get());
527
528  Reader->setDeserializationListener(
529      static_cast<ASTDeserializationListener *>(DeserializationListener),
530      /*TakeOwnership=*/OwnDeserializationListener);
531
532  for (auto &Listener : DependencyCollectors)
533    Listener->attachToASTReader(*Reader);
534
535  switch (Reader->ReadAST(Path,
536                          Preamble ? serialization::MK_Preamble
537                                   : serialization::MK_PCH,
538                          SourceLocation(),
539                          ASTReader::ARR_None)) {
540  case ASTReader::Success:
541    // Set the predefines buffer as suggested by the PCH reader. Typically, the
542    // predefines buffer will be empty.
543    PP.setPredefines(Reader->getSuggestedPredefines());
544    return Reader;
545
546  case ASTReader::Failure:
547    // Unrecoverable failure: don't even try to process the input file.
548    break;
549
550  case ASTReader::Missing:
551  case ASTReader::OutOfDate:
552  case ASTReader::VersionMismatch:
553  case ASTReader::ConfigurationMismatch:
554  case ASTReader::HadErrors:
555    // No suitable PCH file could be found. Return an error.
556    break;
557  }
558
559  Context.setExternalSource(nullptr);
560  return nullptr;
561}
562
563// Code Completion
564
565static bool EnableCodeCompletion(Preprocessor &PP,
566                                 StringRef Filename,
567                                 unsigned Line,
568                                 unsigned Column) {
569  // Tell the source manager to chop off the given file at a specific
570  // line and column.
571  auto Entry = PP.getFileManager().getFile(Filename);
572  if (!Entry) {
573    PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
574      << Filename;
575    return true;
576  }
577
578  // Truncate the named file at the given line/column.
579  PP.SetCodeCompletionPoint(*Entry, Line, Column);
580  return false;
581}
582
583void CompilerInstance::createCodeCompletionConsumer() {
584  const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
585  if (!CompletionConsumer) {
586    setCodeCompletionConsumer(
587      createCodeCompletionConsumer(getPreprocessor(),
588                                   Loc.FileName, Loc.Line, Loc.Column,
589                                   getFrontendOpts().CodeCompleteOpts,
590                                   llvm::outs()));
591    if (!CompletionConsumer)
592      return;
593  } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
594                                  Loc.Line, Loc.Column)) {
595    setCodeCompletionConsumer(nullptr);
596    return;
597  }
598}
599
600void CompilerInstance::createFrontendTimer() {
601  FrontendTimerGroup.reset(
602      new llvm::TimerGroup("frontend", "Clang front-end time report"));
603  FrontendTimer.reset(
604      new llvm::Timer("frontend", "Clang front-end timer",
605                      *FrontendTimerGroup));
606}
607
608CodeCompleteConsumer *
609CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
610                                               StringRef Filename,
611                                               unsigned Line,
612                                               unsigned Column,
613                                               const CodeCompleteOptions &Opts,
614                                               raw_ostream &OS) {
615  if (EnableCodeCompletion(PP, Filename, Line, Column))
616    return nullptr;
617
618  // Set up the creation routine for code-completion.
619  return new PrintingCodeCompleteConsumer(Opts, OS);
620}
621
622void CompilerInstance::createSema(TranslationUnitKind TUKind,
623                                  CodeCompleteConsumer *CompletionConsumer) {
624  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
625                         TUKind, CompletionConsumer));
626  // Attach the external sema source if there is any.
627  if (ExternalSemaSrc) {
628    TheSema->addExternalSource(ExternalSemaSrc.get());
629    ExternalSemaSrc->InitializeSema(*TheSema);
630  }
631}
632
633// Output Files
634
635void CompilerInstance::addOutputFile(OutputFile &&OutFile) {
636  OutputFiles.push_back(std::move(OutFile));
637}
638
639void CompilerInstance::clearOutputFiles(bool EraseFiles) {
640  for (OutputFile &OF : OutputFiles) {
641    if (!OF.TempFilename.empty()) {
642      if (EraseFiles) {
643        llvm::sys::fs::remove(OF.TempFilename);
644      } else {
645        SmallString<128> NewOutFile(OF.Filename);
646
647        // If '-working-directory' was passed, the output filename should be
648        // relative to that.
649        FileMgr->FixupRelativePath(NewOutFile);
650        if (std::error_code ec =
651                llvm::sys::fs::rename(OF.TempFilename, NewOutFile)) {
652          getDiagnostics().Report(diag::err_unable_to_rename_temp)
653            << OF.TempFilename << OF.Filename << ec.message();
654
655          llvm::sys::fs::remove(OF.TempFilename);
656        }
657      }
658    } else if (!OF.Filename.empty() && EraseFiles)
659      llvm::sys::fs::remove(OF.Filename);
660  }
661  OutputFiles.clear();
662  if (DeleteBuiltModules) {
663    for (auto &Module : BuiltModules)
664      llvm::sys::fs::remove(Module.second);
665    BuiltModules.clear();
666  }
667  NonSeekStream.reset();
668}
669
670std::unique_ptr<raw_pwrite_stream>
671CompilerInstance::createDefaultOutputFile(bool Binary, StringRef InFile,
672                                          StringRef Extension) {
673  return createOutputFile(getFrontendOpts().OutputFile, Binary,
674                          /*RemoveFileOnSignal=*/true, InFile, Extension,
675                          /*UseTemporary=*/true);
676}
677
678std::unique_ptr<raw_pwrite_stream> CompilerInstance::createNullOutputFile() {
679  return std::make_unique<llvm::raw_null_ostream>();
680}
681
682std::unique_ptr<raw_pwrite_stream>
683CompilerInstance::createOutputFile(StringRef OutputPath, bool Binary,
684                                   bool RemoveFileOnSignal, StringRef InFile,
685                                   StringRef Extension, bool UseTemporary,
686                                   bool CreateMissingDirectories) {
687  std::string OutputPathName, TempPathName;
688  std::error_code EC;
689  std::unique_ptr<raw_pwrite_stream> OS = createOutputFile(
690      OutputPath, EC, Binary, RemoveFileOnSignal, InFile, Extension,
691      UseTemporary, CreateMissingDirectories, &OutputPathName, &TempPathName);
692  if (!OS) {
693    getDiagnostics().Report(diag::err_fe_unable_to_open_output) << OutputPath
694                                                                << EC.message();
695    return nullptr;
696  }
697
698  // Add the output file -- but don't try to remove "-", since this means we are
699  // using stdin.
700  addOutputFile(
701      OutputFile((OutputPathName != "-") ? OutputPathName : "", TempPathName));
702
703  return OS;
704}
705
706std::unique_ptr<llvm::raw_pwrite_stream> CompilerInstance::createOutputFile(
707    StringRef OutputPath, std::error_code &Error, bool Binary,
708    bool RemoveFileOnSignal, StringRef InFile, StringRef Extension,
709    bool UseTemporary, bool CreateMissingDirectories,
710    std::string *ResultPathName, std::string *TempPathName) {
711  assert((!CreateMissingDirectories || UseTemporary) &&
712         "CreateMissingDirectories is only allowed when using temporary files");
713
714  std::string OutFile, TempFile;
715  if (!OutputPath.empty()) {
716    OutFile = OutputPath;
717  } else if (InFile == "-") {
718    OutFile = "-";
719  } else if (!Extension.empty()) {
720    SmallString<128> Path(InFile);
721    llvm::sys::path::replace_extension(Path, Extension);
722    OutFile = Path.str();
723  } else {
724    OutFile = "-";
725  }
726
727  std::unique_ptr<llvm::raw_fd_ostream> OS;
728  std::string OSFile;
729
730  if (UseTemporary) {
731    if (OutFile == "-")
732      UseTemporary = false;
733    else {
734      llvm::sys::fs::file_status Status;
735      llvm::sys::fs::status(OutputPath, Status);
736      if (llvm::sys::fs::exists(Status)) {
737        // Fail early if we can't write to the final destination.
738        if (!llvm::sys::fs::can_write(OutputPath)) {
739          Error = make_error_code(llvm::errc::operation_not_permitted);
740          return nullptr;
741        }
742
743        // Don't use a temporary if the output is a special file. This handles
744        // things like '-o /dev/null'
745        if (!llvm::sys::fs::is_regular_file(Status))
746          UseTemporary = false;
747      }
748    }
749  }
750
751  if (UseTemporary) {
752    // Create a temporary file.
753    // Insert -%%%%%%%% before the extension (if any), and because some tools
754    // (noticeable, clang's own GlobalModuleIndex.cpp) glob for build
755    // artifacts, also append .tmp.
756    StringRef OutputExtension = llvm::sys::path::extension(OutFile);
757    SmallString<128> TempPath =
758        StringRef(OutFile).drop_back(OutputExtension.size());
759    TempPath += "-%%%%%%%%";
760    TempPath += OutputExtension;
761    TempPath += ".tmp";
762    int fd;
763    std::error_code EC =
764        llvm::sys::fs::createUniqueFile(TempPath, fd, TempPath);
765
766    if (CreateMissingDirectories &&
767        EC == llvm::errc::no_such_file_or_directory) {
768      StringRef Parent = llvm::sys::path::parent_path(OutputPath);
769      EC = llvm::sys::fs::create_directories(Parent);
770      if (!EC) {
771        EC = llvm::sys::fs::createUniqueFile(TempPath, fd, TempPath);
772      }
773    }
774
775    if (!EC) {
776      OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
777      OSFile = TempFile = TempPath.str();
778    }
779    // If we failed to create the temporary, fallback to writing to the file
780    // directly. This handles the corner case where we cannot write to the
781    // directory, but can write to the file.
782  }
783
784  if (!OS) {
785    OSFile = OutFile;
786    OS.reset(new llvm::raw_fd_ostream(
787        OSFile, Error,
788        (Binary ? llvm::sys::fs::OF_None : llvm::sys::fs::OF_Text)));
789    if (Error)
790      return nullptr;
791  }
792
793  // Make sure the out stream file gets removed if we crash.
794  if (RemoveFileOnSignal)
795    llvm::sys::RemoveFileOnSignal(OSFile);
796
797  if (ResultPathName)
798    *ResultPathName = OutFile;
799  if (TempPathName)
800    *TempPathName = TempFile;
801
802  if (!Binary || OS->supportsSeeking())
803    return std::move(OS);
804
805  auto B = std::make_unique<llvm::buffer_ostream>(*OS);
806  assert(!NonSeekStream);
807  NonSeekStream = std::move(OS);
808  return std::move(B);
809}
810
811// Initialization Utilities
812
813bool CompilerInstance::InitializeSourceManager(const FrontendInputFile &Input){
814  return InitializeSourceManager(
815      Input, getDiagnostics(), getFileManager(), getSourceManager(),
816      hasPreprocessor() ? &getPreprocessor().getHeaderSearchInfo() : nullptr,
817      getDependencyOutputOpts(), getFrontendOpts());
818}
819
820// static
821bool CompilerInstance::InitializeSourceManager(
822    const FrontendInputFile &Input, DiagnosticsEngine &Diags,
823    FileManager &FileMgr, SourceManager &SourceMgr, HeaderSearch *HS,
824    DependencyOutputOptions &DepOpts, const FrontendOptions &Opts) {
825  SrcMgr::CharacteristicKind Kind =
826      Input.getKind().getFormat() == InputKind::ModuleMap
827          ? Input.isSystem() ? SrcMgr::C_System_ModuleMap
828                             : SrcMgr::C_User_ModuleMap
829          : Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
830
831  if (Input.isBuffer()) {
832    SourceMgr.setMainFileID(SourceMgr.createFileID(SourceManager::Unowned,
833                                                   Input.getBuffer(), Kind));
834    assert(SourceMgr.getMainFileID().isValid() &&
835           "Couldn't establish MainFileID!");
836    return true;
837  }
838
839  StringRef InputFile = Input.getFile();
840
841  // Figure out where to get and map in the main file.
842  if (InputFile != "-") {
843    auto FileOrErr = FileMgr.getFileRef(InputFile, /*OpenFile=*/true);
844    if (!FileOrErr) {
845      // FIXME: include the error in the diagnostic.
846      consumeError(FileOrErr.takeError());
847      Diags.Report(diag::err_fe_error_reading) << InputFile;
848      return false;
849    }
850    FileEntryRef File = *FileOrErr;
851
852    // The natural SourceManager infrastructure can't currently handle named
853    // pipes, but we would at least like to accept them for the main
854    // file. Detect them here, read them with the volatile flag so FileMgr will
855    // pick up the correct size, and simply override their contents as we do for
856    // STDIN.
857    if (File.getFileEntry().isNamedPipe()) {
858      auto MB =
859          FileMgr.getBufferForFile(&File.getFileEntry(), /*isVolatile=*/true);
860      if (MB) {
861        // Create a new virtual file that will have the correct size.
862        const FileEntry *FE =
863            FileMgr.getVirtualFile(InputFile, (*MB)->getBufferSize(), 0);
864        SourceMgr.overrideFileContents(FE, std::move(*MB));
865        SourceMgr.setMainFileID(
866            SourceMgr.createFileID(FE, SourceLocation(), Kind));
867      } else {
868        Diags.Report(diag::err_cannot_open_file) << InputFile
869                                                 << MB.getError().message();
870        return false;
871      }
872    } else {
873      SourceMgr.setMainFileID(
874          SourceMgr.createFileID(File, SourceLocation(), Kind));
875    }
876  } else {
877    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> SBOrErr =
878        llvm::MemoryBuffer::getSTDIN();
879    if (std::error_code EC = SBOrErr.getError()) {
880      Diags.Report(diag::err_fe_error_reading_stdin) << EC.message();
881      return false;
882    }
883    std::unique_ptr<llvm::MemoryBuffer> SB = std::move(SBOrErr.get());
884
885    const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
886                                                   SB->getBufferSize(), 0);
887    SourceMgr.setMainFileID(
888        SourceMgr.createFileID(File, SourceLocation(), Kind));
889    SourceMgr.overrideFileContents(File, std::move(SB));
890  }
891
892  assert(SourceMgr.getMainFileID().isValid() &&
893         "Couldn't establish MainFileID!");
894  return true;
895}
896
897// High-Level Operations
898
899bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
900  assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
901  assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
902  assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
903
904  // Mark this point as the bottom of the stack if we don't have somewhere
905  // better. We generally expect frontend actions to be invoked with (nearly)
906  // DesiredStackSpace available.
907  noteBottomOfStack();
908
909  raw_ostream &OS = getVerboseOutputStream();
910
911  if (!Act.PrepareToExecute(*this))
912    return false;
913
914  // Create the target instance.
915  setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(),
916                                         getInvocation().TargetOpts));
917  if (!hasTarget())
918    return false;
919
920  // Create TargetInfo for the other side of CUDA and OpenMP compilation.
921  if ((getLangOpts().CUDA || getLangOpts().OpenMPIsDevice) &&
922      !getFrontendOpts().AuxTriple.empty()) {
923    auto TO = std::make_shared<TargetOptions>();
924    TO->Triple = llvm::Triple::normalize(getFrontendOpts().AuxTriple);
925    TO->HostTriple = getTarget().getTriple().str();
926    setAuxTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), TO));
927  }
928
929  // Inform the target of the language options.
930  //
931  // FIXME: We shouldn't need to do this, the target should be immutable once
932  // created. This complexity should be lifted elsewhere.
933  getTarget().adjust(getLangOpts());
934
935  // Adjust target options based on codegen options.
936  getTarget().adjustTargetOptions(getCodeGenOpts(), getTargetOpts());
937
938  if (auto *Aux = getAuxTarget())
939    getTarget().setAuxTarget(Aux);
940
941  // rewriter project will change target built-in bool type from its default.
942  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
943    getTarget().noSignedCharForObjCBool();
944
945  // Validate/process some options.
946  if (getHeaderSearchOpts().Verbose)
947    OS << "clang -cc1 version " CLANG_VERSION_STRING
948       << " based upon " << BACKEND_PACKAGE_STRING
949       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
950
951  if (getFrontendOpts().ShowTimers)
952    createFrontendTimer();
953
954  if (getFrontendOpts().ShowStats || !getFrontendOpts().StatsFile.empty())
955    llvm::EnableStatistics(false);
956
957  for (const FrontendInputFile &FIF : getFrontendOpts().Inputs) {
958    // Reset the ID tables if we are reusing the SourceManager and parsing
959    // regular files.
960    if (hasSourceManager() && !Act.isModelParsingAction())
961      getSourceManager().clearIDTables();
962
963    if (Act.BeginSourceFile(*this, FIF)) {
964      if (llvm::Error Err = Act.Execute()) {
965        consumeError(std::move(Err)); // FIXME this drops errors on the floor.
966      }
967      Act.EndSourceFile();
968    }
969  }
970
971  // Notify the diagnostic client that all files were processed.
972  getDiagnostics().getClient()->finish();
973
974  if (getDiagnosticOpts().ShowCarets) {
975    // We can have multiple diagnostics sharing one diagnostic client.
976    // Get the total number of warnings/errors from the client.
977    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
978    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
979
980    if (NumWarnings)
981      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
982    if (NumWarnings && NumErrors)
983      OS << " and ";
984    if (NumErrors)
985      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
986    if (NumWarnings || NumErrors) {
987      OS << " generated";
988      if (getLangOpts().CUDA) {
989        if (!getLangOpts().CUDAIsDevice) {
990          OS << " when compiling for host";
991        } else {
992          OS << " when compiling for " << getTargetOpts().CPU;
993        }
994      }
995      OS << ".\n";
996    }
997  }
998
999  if (getFrontendOpts().ShowStats) {
1000    if (hasFileManager()) {
1001      getFileManager().PrintStats();
1002      OS << '\n';
1003    }
1004    llvm::PrintStatistics(OS);
1005  }
1006  StringRef StatsFile = getFrontendOpts().StatsFile;
1007  if (!StatsFile.empty()) {
1008    std::error_code EC;
1009    auto StatS = std::make_unique<llvm::raw_fd_ostream>(
1010        StatsFile, EC, llvm::sys::fs::OF_Text);
1011    if (EC) {
1012      getDiagnostics().Report(diag::warn_fe_unable_to_open_stats_file)
1013          << StatsFile << EC.message();
1014    } else {
1015      llvm::PrintStatisticsJSON(*StatS);
1016    }
1017  }
1018
1019  return !getDiagnostics().getClient()->getNumErrors();
1020}
1021
1022/// Determine the appropriate source input kind based on language
1023/// options.
1024static Language getLanguageFromOptions(const LangOptions &LangOpts) {
1025  if (LangOpts.OpenCL)
1026    return Language::OpenCL;
1027  if (LangOpts.CUDA)
1028    return Language::CUDA;
1029  if (LangOpts.ObjC)
1030    return LangOpts.CPlusPlus ? Language::ObjCXX : Language::ObjC;
1031  return LangOpts.CPlusPlus ? Language::CXX : Language::C;
1032}
1033
1034/// Compile a module file for the given module, using the options
1035/// provided by the importing compiler instance. Returns true if the module
1036/// was built without errors.
1037static bool
1038compileModuleImpl(CompilerInstance &ImportingInstance, SourceLocation ImportLoc,
1039                  StringRef ModuleName, FrontendInputFile Input,
1040                  StringRef OriginalModuleMapFile, StringRef ModuleFileName,
1041                  llvm::function_ref<void(CompilerInstance &)> PreBuildStep =
1042                      [](CompilerInstance &) {},
1043                  llvm::function_ref<void(CompilerInstance &)> PostBuildStep =
1044                      [](CompilerInstance &) {}) {
1045  llvm::TimeTraceScope TimeScope("Module Compile", ModuleName);
1046
1047  // Construct a compiler invocation for creating this module.
1048  auto Invocation =
1049      std::make_shared<CompilerInvocation>(ImportingInstance.getInvocation());
1050
1051  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
1052
1053  // For any options that aren't intended to affect how a module is built,
1054  // reset them to their default values.
1055  Invocation->getLangOpts()->resetNonModularOptions();
1056  PPOpts.resetNonModularOptions();
1057
1058  // Remove any macro definitions that are explicitly ignored by the module.
1059  // They aren't supposed to affect how the module is built anyway.
1060  HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
1061  PPOpts.Macros.erase(
1062      std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
1063                     [&HSOpts](const std::pair<std::string, bool> &def) {
1064        StringRef MacroDef = def.first;
1065        return HSOpts.ModulesIgnoreMacros.count(
1066                   llvm::CachedHashString(MacroDef.split('=').first)) > 0;
1067      }),
1068      PPOpts.Macros.end());
1069
1070  // If the original compiler invocation had -fmodule-name, pass it through.
1071  Invocation->getLangOpts()->ModuleName =
1072      ImportingInstance.getInvocation().getLangOpts()->ModuleName;
1073
1074  // Note the name of the module we're building.
1075  Invocation->getLangOpts()->CurrentModule = ModuleName;
1076
1077  // Make sure that the failed-module structure has been allocated in
1078  // the importing instance, and propagate the pointer to the newly-created
1079  // instance.
1080  PreprocessorOptions &ImportingPPOpts
1081    = ImportingInstance.getInvocation().getPreprocessorOpts();
1082  if (!ImportingPPOpts.FailedModules)
1083    ImportingPPOpts.FailedModules =
1084        std::make_shared<PreprocessorOptions::FailedModulesSet>();
1085  PPOpts.FailedModules = ImportingPPOpts.FailedModules;
1086
1087  // If there is a module map file, build the module using the module map.
1088  // Set up the inputs/outputs so that we build the module from its umbrella
1089  // header.
1090  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
1091  FrontendOpts.OutputFile = ModuleFileName.str();
1092  FrontendOpts.DisableFree = false;
1093  FrontendOpts.GenerateGlobalModuleIndex = false;
1094  FrontendOpts.BuildingImplicitModule = true;
1095  FrontendOpts.OriginalModuleMap = OriginalModuleMapFile;
1096  // Force implicitly-built modules to hash the content of the module file.
1097  HSOpts.ModulesHashContent = true;
1098  FrontendOpts.Inputs = {Input};
1099
1100  // Don't free the remapped file buffers; they are owned by our caller.
1101  PPOpts.RetainRemappedFileBuffers = true;
1102
1103  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
1104  assert(ImportingInstance.getInvocation().getModuleHash() ==
1105         Invocation->getModuleHash() && "Module hash mismatch!");
1106
1107  // Construct a compiler instance that will be used to actually create the
1108  // module.  Since we're sharing an in-memory module cache,
1109  // CompilerInstance::CompilerInstance is responsible for finalizing the
1110  // buffers to prevent use-after-frees.
1111  CompilerInstance Instance(ImportingInstance.getPCHContainerOperations(),
1112                            &ImportingInstance.getModuleCache());
1113  auto &Inv = *Invocation;
1114  Instance.setInvocation(std::move(Invocation));
1115
1116  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
1117                                   ImportingInstance.getDiagnosticClient()),
1118                             /*ShouldOwnClient=*/true);
1119
1120  // Note that this module is part of the module build stack, so that we
1121  // can detect cycles in the module graph.
1122  Instance.setFileManager(&ImportingInstance.getFileManager());
1123  Instance.createSourceManager(Instance.getFileManager());
1124  SourceManager &SourceMgr = Instance.getSourceManager();
1125  SourceMgr.setModuleBuildStack(
1126    ImportingInstance.getSourceManager().getModuleBuildStack());
1127  SourceMgr.pushModuleBuildStack(ModuleName,
1128    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
1129
1130  // If we're collecting module dependencies, we need to share a collector
1131  // between all of the module CompilerInstances. Other than that, we don't
1132  // want to produce any dependency output from the module build.
1133  Instance.setModuleDepCollector(ImportingInstance.getModuleDepCollector());
1134  Inv.getDependencyOutputOpts() = DependencyOutputOptions();
1135
1136  ImportingInstance.getDiagnostics().Report(ImportLoc,
1137                                            diag::remark_module_build)
1138    << ModuleName << ModuleFileName;
1139
1140  PreBuildStep(Instance);
1141
1142  // Execute the action to actually build the module in-place. Use a separate
1143  // thread so that we get a stack large enough.
1144  llvm::CrashRecoveryContext CRC;
1145  CRC.RunSafelyOnThread(
1146      [&]() {
1147        GenerateModuleFromModuleMapAction Action;
1148        Instance.ExecuteAction(Action);
1149      },
1150      DesiredStackSize);
1151
1152  PostBuildStep(Instance);
1153
1154  ImportingInstance.getDiagnostics().Report(ImportLoc,
1155                                            diag::remark_module_build_done)
1156    << ModuleName;
1157
1158  // Delete the temporary module map file.
1159  // FIXME: Even though we're executing under crash protection, it would still
1160  // be nice to do this with RemoveFileOnSignal when we can. However, that
1161  // doesn't make sense for all clients, so clean this up manually.
1162  Instance.clearOutputFiles(/*EraseFiles=*/true);
1163
1164  return !Instance.getDiagnostics().hasErrorOccurred();
1165}
1166
1167static const FileEntry *getPublicModuleMap(const FileEntry *File,
1168                                           FileManager &FileMgr) {
1169  StringRef Filename = llvm::sys::path::filename(File->getName());
1170  SmallString<128> PublicFilename(File->getDir()->getName());
1171  if (Filename == "module_private.map")
1172    llvm::sys::path::append(PublicFilename, "module.map");
1173  else if (Filename == "module.private.modulemap")
1174    llvm::sys::path::append(PublicFilename, "module.modulemap");
1175  else
1176    return nullptr;
1177  if (auto FE = FileMgr.getFile(PublicFilename))
1178    return *FE;
1179  return nullptr;
1180}
1181
1182/// Compile a module file for the given module, using the options
1183/// provided by the importing compiler instance. Returns true if the module
1184/// was built without errors.
1185static bool compileModuleImpl(CompilerInstance &ImportingInstance,
1186                              SourceLocation ImportLoc,
1187                              Module *Module,
1188                              StringRef ModuleFileName) {
1189  InputKind IK(getLanguageFromOptions(ImportingInstance.getLangOpts()),
1190               InputKind::ModuleMap);
1191
1192  // Get or create the module map that we'll use to build this module.
1193  ModuleMap &ModMap
1194    = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
1195  bool Result;
1196  if (const FileEntry *ModuleMapFile =
1197          ModMap.getContainingModuleMapFile(Module)) {
1198    // Canonicalize compilation to start with the public module map. This is
1199    // vital for submodules declarations in the private module maps to be
1200    // correctly parsed when depending on a top level module in the public one.
1201    if (const FileEntry *PublicMMFile = getPublicModuleMap(
1202            ModuleMapFile, ImportingInstance.getFileManager()))
1203      ModuleMapFile = PublicMMFile;
1204
1205    // Use the module map where this module resides.
1206    Result = compileModuleImpl(
1207        ImportingInstance, ImportLoc, Module->getTopLevelModuleName(),
1208        FrontendInputFile(ModuleMapFile->getName(), IK, +Module->IsSystem),
1209        ModMap.getModuleMapFileForUniquing(Module)->getName(),
1210        ModuleFileName);
1211  } else {
1212    // FIXME: We only need to fake up an input file here as a way of
1213    // transporting the module's directory to the module map parser. We should
1214    // be able to do that more directly, and parse from a memory buffer without
1215    // inventing this file.
1216    SmallString<128> FakeModuleMapFile(Module->Directory->getName());
1217    llvm::sys::path::append(FakeModuleMapFile, "__inferred_module.map");
1218
1219    std::string InferredModuleMapContent;
1220    llvm::raw_string_ostream OS(InferredModuleMapContent);
1221    Module->print(OS);
1222    OS.flush();
1223
1224    Result = compileModuleImpl(
1225        ImportingInstance, ImportLoc, Module->getTopLevelModuleName(),
1226        FrontendInputFile(FakeModuleMapFile, IK, +Module->IsSystem),
1227        ModMap.getModuleMapFileForUniquing(Module)->getName(),
1228        ModuleFileName,
1229        [&](CompilerInstance &Instance) {
1230      std::unique_ptr<llvm::MemoryBuffer> ModuleMapBuffer =
1231          llvm::MemoryBuffer::getMemBuffer(InferredModuleMapContent);
1232      ModuleMapFile = Instance.getFileManager().getVirtualFile(
1233          FakeModuleMapFile, InferredModuleMapContent.size(), 0);
1234      Instance.getSourceManager().overrideFileContents(
1235          ModuleMapFile, std::move(ModuleMapBuffer));
1236    });
1237  }
1238
1239  // We've rebuilt a module. If we're allowed to generate or update the global
1240  // module index, record that fact in the importing compiler instance.
1241  if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
1242    ImportingInstance.setBuildGlobalModuleIndex(true);
1243  }
1244
1245  return Result;
1246}
1247
1248static bool compileAndLoadModule(CompilerInstance &ImportingInstance,
1249                                 SourceLocation ImportLoc,
1250                                 SourceLocation ModuleNameLoc, Module *Module,
1251                                 StringRef ModuleFileName) {
1252  DiagnosticsEngine &Diags = ImportingInstance.getDiagnostics();
1253
1254  auto diagnoseBuildFailure = [&] {
1255    Diags.Report(ModuleNameLoc, diag::err_module_not_built)
1256        << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
1257  };
1258
1259  // FIXME: have LockFileManager return an error_code so that we can
1260  // avoid the mkdir when the directory already exists.
1261  StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
1262  llvm::sys::fs::create_directories(Dir);
1263
1264  while (1) {
1265    unsigned ModuleLoadCapabilities = ASTReader::ARR_Missing;
1266    llvm::LockFileManager Locked(ModuleFileName);
1267    switch (Locked) {
1268    case llvm::LockFileManager::LFS_Error:
1269      // ModuleCache takes care of correctness and locks are only necessary for
1270      // performance. Fallback to building the module in case of any lock
1271      // related errors.
1272      Diags.Report(ModuleNameLoc, diag::remark_module_lock_failure)
1273          << Module->Name << Locked.getErrorMessage();
1274      // Clear out any potential leftover.
1275      Locked.unsafeRemoveLockFile();
1276      LLVM_FALLTHROUGH;
1277    case llvm::LockFileManager::LFS_Owned:
1278      // We're responsible for building the module ourselves.
1279      if (!compileModuleImpl(ImportingInstance, ModuleNameLoc, Module,
1280                             ModuleFileName)) {
1281        diagnoseBuildFailure();
1282        return false;
1283      }
1284      break;
1285
1286    case llvm::LockFileManager::LFS_Shared:
1287      // Someone else is responsible for building the module. Wait for them to
1288      // finish.
1289      switch (Locked.waitForUnlock()) {
1290      case llvm::LockFileManager::Res_Success:
1291        ModuleLoadCapabilities |= ASTReader::ARR_OutOfDate;
1292        break;
1293      case llvm::LockFileManager::Res_OwnerDied:
1294        continue; // try again to get the lock.
1295      case llvm::LockFileManager::Res_Timeout:
1296        // Since ModuleCache takes care of correctness, we try waiting for
1297        // another process to complete the build so clang does not do it done
1298        // twice. If case of timeout, build it ourselves.
1299        Diags.Report(ModuleNameLoc, diag::remark_module_lock_timeout)
1300            << Module->Name;
1301        // Clear the lock file so that future invocations can make progress.
1302        Locked.unsafeRemoveLockFile();
1303        continue;
1304      }
1305      break;
1306    }
1307
1308    // Try to read the module file, now that we've compiled it.
1309    ASTReader::ASTReadResult ReadResult =
1310        ImportingInstance.getModuleManager()->ReadAST(
1311            ModuleFileName, serialization::MK_ImplicitModule, ImportLoc,
1312            ModuleLoadCapabilities);
1313
1314    if (ReadResult == ASTReader::OutOfDate &&
1315        Locked == llvm::LockFileManager::LFS_Shared) {
1316      // The module may be out of date in the presence of file system races,
1317      // or if one of its imports depends on header search paths that are not
1318      // consistent with this ImportingInstance.  Try again...
1319      continue;
1320    } else if (ReadResult == ASTReader::Missing) {
1321      diagnoseBuildFailure();
1322    } else if (ReadResult != ASTReader::Success &&
1323               !Diags.hasErrorOccurred()) {
1324      // The ASTReader didn't diagnose the error, so conservatively report it.
1325      diagnoseBuildFailure();
1326    }
1327    return ReadResult == ASTReader::Success;
1328  }
1329}
1330
1331/// Diagnose differences between the current definition of the given
1332/// configuration macro and the definition provided on the command line.
1333static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
1334                             Module *Mod, SourceLocation ImportLoc) {
1335  IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
1336  SourceManager &SourceMgr = PP.getSourceManager();
1337
1338  // If this identifier has never had a macro definition, then it could
1339  // not have changed.
1340  if (!Id->hadMacroDefinition())
1341    return;
1342  auto *LatestLocalMD = PP.getLocalMacroDirectiveHistory(Id);
1343
1344  // Find the macro definition from the command line.
1345  MacroInfo *CmdLineDefinition = nullptr;
1346  for (auto *MD = LatestLocalMD; MD; MD = MD->getPrevious()) {
1347    // We only care about the predefines buffer.
1348    FileID FID = SourceMgr.getFileID(MD->getLocation());
1349    if (FID.isInvalid() || FID != PP.getPredefinesFileID())
1350      continue;
1351    if (auto *DMD = dyn_cast<DefMacroDirective>(MD))
1352      CmdLineDefinition = DMD->getMacroInfo();
1353    break;
1354  }
1355
1356  auto *CurrentDefinition = PP.getMacroInfo(Id);
1357  if (CurrentDefinition == CmdLineDefinition) {
1358    // Macro matches. Nothing to do.
1359  } else if (!CurrentDefinition) {
1360    // This macro was defined on the command line, then #undef'd later.
1361    // Complain.
1362    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1363      << true << ConfigMacro << Mod->getFullModuleName();
1364    auto LatestDef = LatestLocalMD->getDefinition();
1365    assert(LatestDef.isUndefined() &&
1366           "predefined macro went away with no #undef?");
1367    PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
1368      << true;
1369    return;
1370  } else if (!CmdLineDefinition) {
1371    // There was no definition for this macro in the predefines buffer,
1372    // but there was a local definition. Complain.
1373    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1374      << false << ConfigMacro << Mod->getFullModuleName();
1375    PP.Diag(CurrentDefinition->getDefinitionLoc(),
1376            diag::note_module_def_undef_here)
1377      << false;
1378  } else if (!CurrentDefinition->isIdenticalTo(*CmdLineDefinition, PP,
1379                                               /*Syntactically=*/true)) {
1380    // The macro definitions differ.
1381    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1382      << false << ConfigMacro << Mod->getFullModuleName();
1383    PP.Diag(CurrentDefinition->getDefinitionLoc(),
1384            diag::note_module_def_undef_here)
1385      << false;
1386  }
1387}
1388
1389/// Write a new timestamp file with the given path.
1390static void writeTimestampFile(StringRef TimestampFile) {
1391  std::error_code EC;
1392  llvm::raw_fd_ostream Out(TimestampFile.str(), EC, llvm::sys::fs::OF_None);
1393}
1394
1395/// Prune the module cache of modules that haven't been accessed in
1396/// a long time.
1397static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1398  llvm::sys::fs::file_status StatBuf;
1399  llvm::SmallString<128> TimestampFile;
1400  TimestampFile = HSOpts.ModuleCachePath;
1401  assert(!TimestampFile.empty());
1402  llvm::sys::path::append(TimestampFile, "modules.timestamp");
1403
1404  // Try to stat() the timestamp file.
1405  if (std::error_code EC = llvm::sys::fs::status(TimestampFile, StatBuf)) {
1406    // If the timestamp file wasn't there, create one now.
1407    if (EC == std::errc::no_such_file_or_directory) {
1408      writeTimestampFile(TimestampFile);
1409    }
1410    return;
1411  }
1412
1413  // Check whether the time stamp is older than our pruning interval.
1414  // If not, do nothing.
1415  time_t TimeStampModTime =
1416      llvm::sys::toTimeT(StatBuf.getLastModificationTime());
1417  time_t CurrentTime = time(nullptr);
1418  if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1419    return;
1420
1421  // Write a new timestamp file so that nobody else attempts to prune.
1422  // There is a benign race condition here, if two Clang instances happen to
1423  // notice at the same time that the timestamp is out-of-date.
1424  writeTimestampFile(TimestampFile);
1425
1426  // Walk the entire module cache, looking for unused module files and module
1427  // indices.
1428  std::error_code EC;
1429  SmallString<128> ModuleCachePathNative;
1430  llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1431  for (llvm::sys::fs::directory_iterator Dir(ModuleCachePathNative, EC), DirEnd;
1432       Dir != DirEnd && !EC; Dir.increment(EC)) {
1433    // If we don't have a directory, there's nothing to look into.
1434    if (!llvm::sys::fs::is_directory(Dir->path()))
1435      continue;
1436
1437    // Walk all of the files within this directory.
1438    for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1439         File != FileEnd && !EC; File.increment(EC)) {
1440      // We only care about module and global module index files.
1441      StringRef Extension = llvm::sys::path::extension(File->path());
1442      if (Extension != ".pcm" && Extension != ".timestamp" &&
1443          llvm::sys::path::filename(File->path()) != "modules.idx")
1444        continue;
1445
1446      // Look at this file. If we can't stat it, there's nothing interesting
1447      // there.
1448      if (llvm::sys::fs::status(File->path(), StatBuf))
1449        continue;
1450
1451      // If the file has been used recently enough, leave it there.
1452      time_t FileAccessTime = llvm::sys::toTimeT(StatBuf.getLastAccessedTime());
1453      if (CurrentTime - FileAccessTime <=
1454              time_t(HSOpts.ModuleCachePruneAfter)) {
1455        continue;
1456      }
1457
1458      // Remove the file.
1459      llvm::sys::fs::remove(File->path());
1460
1461      // Remove the timestamp file.
1462      std::string TimpestampFilename = File->path() + ".timestamp";
1463      llvm::sys::fs::remove(TimpestampFilename);
1464    }
1465
1466    // If we removed all of the files in the directory, remove the directory
1467    // itself.
1468    if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1469            llvm::sys::fs::directory_iterator() && !EC)
1470      llvm::sys::fs::remove(Dir->path());
1471  }
1472}
1473
1474void CompilerInstance::createModuleManager() {
1475  if (!ModuleManager) {
1476    if (!hasASTContext())
1477      createASTContext();
1478
1479    // If we're implicitly building modules but not currently recursively
1480    // building a module, check whether we need to prune the module cache.
1481    if (getSourceManager().getModuleBuildStack().empty() &&
1482        !getPreprocessor().getHeaderSearchInfo().getModuleCachePath().empty() &&
1483        getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1484        getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1485      pruneModuleCache(getHeaderSearchOpts());
1486    }
1487
1488    HeaderSearchOptions &HSOpts = getHeaderSearchOpts();
1489    std::string Sysroot = HSOpts.Sysroot;
1490    const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1491    std::unique_ptr<llvm::Timer> ReadTimer;
1492    if (FrontendTimerGroup)
1493      ReadTimer = std::make_unique<llvm::Timer>("reading_modules",
1494                                                 "Reading modules",
1495                                                 *FrontendTimerGroup);
1496    ModuleManager = new ASTReader(
1497        getPreprocessor(), getModuleCache(), &getASTContext(),
1498        getPCHContainerReader(), getFrontendOpts().ModuleFileExtensions,
1499        Sysroot.empty() ? "" : Sysroot.c_str(), PPOpts.DisablePCHValidation,
1500        /*AllowASTWithCompilerErrors=*/false,
1501        /*AllowConfigurationMismatch=*/false,
1502        HSOpts.ModulesValidateSystemHeaders,
1503        HSOpts.ValidateASTInputFilesContent,
1504        getFrontendOpts().UseGlobalModuleIndex, std::move(ReadTimer));
1505    if (hasASTConsumer()) {
1506      ModuleManager->setDeserializationListener(
1507        getASTConsumer().GetASTDeserializationListener());
1508      getASTContext().setASTMutationListener(
1509        getASTConsumer().GetASTMutationListener());
1510    }
1511    getASTContext().setExternalSource(ModuleManager);
1512    if (hasSema())
1513      ModuleManager->InitializeSema(getSema());
1514    if (hasASTConsumer())
1515      ModuleManager->StartTranslationUnit(&getASTConsumer());
1516
1517    for (auto &Listener : DependencyCollectors)
1518      Listener->attachToASTReader(*ModuleManager);
1519  }
1520}
1521
1522bool CompilerInstance::loadModuleFile(StringRef FileName) {
1523  llvm::Timer Timer;
1524  if (FrontendTimerGroup)
1525    Timer.init("preloading." + FileName.str(), "Preloading " + FileName.str(),
1526               *FrontendTimerGroup);
1527  llvm::TimeRegion TimeLoading(FrontendTimerGroup ? &Timer : nullptr);
1528
1529  // Helper to recursively read the module names for all modules we're adding.
1530  // We mark these as known and redirect any attempt to load that module to
1531  // the files we were handed.
1532  struct ReadModuleNames : ASTReaderListener {
1533    CompilerInstance &CI;
1534    llvm::SmallVector<IdentifierInfo*, 8> LoadedModules;
1535
1536    ReadModuleNames(CompilerInstance &CI) : CI(CI) {}
1537
1538    void ReadModuleName(StringRef ModuleName) override {
1539      LoadedModules.push_back(
1540          CI.getPreprocessor().getIdentifierInfo(ModuleName));
1541    }
1542
1543    void registerAll() {
1544      for (auto *II : LoadedModules) {
1545        CI.KnownModules[II] = CI.getPreprocessor()
1546                                  .getHeaderSearchInfo()
1547                                  .getModuleMap()
1548                                  .findModule(II->getName());
1549      }
1550      LoadedModules.clear();
1551    }
1552
1553    void markAllUnavailable() {
1554      for (auto *II : LoadedModules) {
1555        if (Module *M = CI.getPreprocessor()
1556                            .getHeaderSearchInfo()
1557                            .getModuleMap()
1558                            .findModule(II->getName())) {
1559          M->HasIncompatibleModuleFile = true;
1560
1561          // Mark module as available if the only reason it was unavailable
1562          // was missing headers.
1563          SmallVector<Module *, 2> Stack;
1564          Stack.push_back(M);
1565          while (!Stack.empty()) {
1566            Module *Current = Stack.pop_back_val();
1567            if (Current->IsMissingRequirement) continue;
1568            Current->IsAvailable = true;
1569            Stack.insert(Stack.end(),
1570                         Current->submodule_begin(), Current->submodule_end());
1571          }
1572        }
1573      }
1574      LoadedModules.clear();
1575    }
1576  };
1577
1578  // If we don't already have an ASTReader, create one now.
1579  if (!ModuleManager)
1580    createModuleManager();
1581
1582  // If -Wmodule-file-config-mismatch is mapped as an error or worse, allow the
1583  // ASTReader to diagnose it, since it can produce better errors that we can.
1584  bool ConfigMismatchIsRecoverable =
1585      getDiagnostics().getDiagnosticLevel(diag::warn_module_config_mismatch,
1586                                          SourceLocation())
1587        <= DiagnosticsEngine::Warning;
1588
1589  auto Listener = std::make_unique<ReadModuleNames>(*this);
1590  auto &ListenerRef = *Listener;
1591  ASTReader::ListenerScope ReadModuleNamesListener(*ModuleManager,
1592                                                   std::move(Listener));
1593
1594  // Try to load the module file.
1595  switch (ModuleManager->ReadAST(
1596      FileName, serialization::MK_ExplicitModule, SourceLocation(),
1597      ConfigMismatchIsRecoverable ? ASTReader::ARR_ConfigurationMismatch : 0)) {
1598  case ASTReader::Success:
1599    // We successfully loaded the module file; remember the set of provided
1600    // modules so that we don't try to load implicit modules for them.
1601    ListenerRef.registerAll();
1602    return true;
1603
1604  case ASTReader::ConfigurationMismatch:
1605    // Ignore unusable module files.
1606    getDiagnostics().Report(SourceLocation(), diag::warn_module_config_mismatch)
1607        << FileName;
1608    // All modules provided by any files we tried and failed to load are now
1609    // unavailable; includes of those modules should now be handled textually.
1610    ListenerRef.markAllUnavailable();
1611    return true;
1612
1613  default:
1614    return false;
1615  }
1616}
1617
1618ModuleLoadResult
1619CompilerInstance::loadModule(SourceLocation ImportLoc,
1620                             ModuleIdPath Path,
1621                             Module::NameVisibilityKind Visibility,
1622                             bool IsInclusionDirective) {
1623  // Determine what file we're searching from.
1624  StringRef ModuleName = Path[0].first->getName();
1625  SourceLocation ModuleNameLoc = Path[0].second;
1626
1627  // If we've already handled this import, just return the cached result.
1628  // This one-element cache is important to eliminate redundant diagnostics
1629  // when both the preprocessor and parser see the same import declaration.
1630  if (ImportLoc.isValid() && LastModuleImportLoc == ImportLoc) {
1631    // Make the named module visible.
1632    if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1633      ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
1634                                       ImportLoc);
1635    return LastModuleImportResult;
1636  }
1637
1638  clang::Module *Module = nullptr;
1639
1640  // If we don't already have information on this module, load the module now.
1641  llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
1642    = KnownModules.find(Path[0].first);
1643  if (Known != KnownModules.end()) {
1644    // Retrieve the cached top-level module.
1645    Module = Known->second;
1646  } else if (ModuleName == getLangOpts().CurrentModule) {
1647    // This is the module we're building.
1648    Module = PP->getHeaderSearchInfo().lookupModule(
1649        ModuleName, /*AllowSearch*/ true,
1650        /*AllowExtraModuleMapSearch*/ !IsInclusionDirective);
1651    /// FIXME: perhaps we should (a) look for a module using the module name
1652    //  to file map (PrebuiltModuleFiles) and (b) diagnose if still not found?
1653    //if (Module == nullptr) {
1654    //  getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1655    //    << ModuleName;
1656    //  ModuleBuildFailed = true;
1657    //  return ModuleLoadResult();
1658    //}
1659    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1660  } else {
1661    // Search for a module with the given name.
1662    Module = PP->getHeaderSearchInfo().lookupModule(ModuleName, true,
1663                                                    !IsInclusionDirective);
1664    HeaderSearchOptions &HSOpts =
1665        PP->getHeaderSearchInfo().getHeaderSearchOpts();
1666
1667    std::string ModuleFileName;
1668    enum ModuleSource {
1669      ModuleNotFound, ModuleCache, PrebuiltModulePath, ModuleBuildPragma
1670    } Source = ModuleNotFound;
1671
1672    // Check to see if the module has been built as part of this compilation
1673    // via a module build pragma.
1674    auto BuiltModuleIt = BuiltModules.find(ModuleName);
1675    if (BuiltModuleIt != BuiltModules.end()) {
1676      ModuleFileName = BuiltModuleIt->second;
1677      Source = ModuleBuildPragma;
1678    }
1679
1680    // Try to load the module from the prebuilt module path.
1681    if (Source == ModuleNotFound && (!HSOpts.PrebuiltModuleFiles.empty() ||
1682                                     !HSOpts.PrebuiltModulePaths.empty())) {
1683      ModuleFileName =
1684        PP->getHeaderSearchInfo().getPrebuiltModuleFileName(ModuleName);
1685      if (!ModuleFileName.empty())
1686        Source = PrebuiltModulePath;
1687    }
1688
1689    // Try to load the module from the module cache.
1690    if (Source == ModuleNotFound && Module) {
1691      ModuleFileName = PP->getHeaderSearchInfo().getCachedModuleFileName(Module);
1692      Source = ModuleCache;
1693    }
1694
1695    if (Source == 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      return ModuleLoadResult();
1701    }
1702
1703    if (ModuleFileName.empty()) {
1704      if (Module && Module->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      return ModuleLoadResult();
1714    }
1715
1716    // If we don't already have an ASTReader, create one now.
1717    if (!ModuleManager)
1718      createModuleManager();
1719
1720    llvm::Timer Timer;
1721    if (FrontendTimerGroup)
1722      Timer.init("loading." + ModuleFileName, "Loading " + ModuleFileName,
1723                 *FrontendTimerGroup);
1724    llvm::TimeRegion TimeLoading(FrontendTimerGroup ? &Timer : nullptr);
1725    llvm::TimeTraceScope TimeScope("Module Load", ModuleName);
1726
1727    // Try to load the module file. If we are not trying to load from the
1728    // module cache, we don't know how to rebuild modules.
1729    unsigned ARRFlags = Source == ModuleCache ?
1730                        ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing :
1731                        Source == PrebuiltModulePath ?
1732                            0 :
1733                            ASTReader::ARR_ConfigurationMismatch;
1734    switch (ModuleManager->ReadAST(ModuleFileName,
1735                                   Source == PrebuiltModulePath
1736                                       ? serialization::MK_PrebuiltModule
1737                                       : Source == ModuleBuildPragma
1738                                             ? serialization::MK_ExplicitModule
1739                                             : serialization::MK_ImplicitModule,
1740                                   ImportLoc, ARRFlags)) {
1741    case ASTReader::Success: {
1742      if (Source != ModuleCache && !Module) {
1743        Module = PP->getHeaderSearchInfo().lookupModule(ModuleName, true,
1744                                                        !IsInclusionDirective);
1745        auto ModuleFile = FileMgr->getFile(ModuleFileName);
1746        if (!Module || !Module->getASTFile() ||
1747            !ModuleFile || (*ModuleFile != Module->getASTFile())) {
1748          // Error out if Module does not refer to the file in the prebuilt
1749          // module path.
1750          getDiagnostics().Report(ModuleNameLoc, diag::err_module_prebuilt)
1751              << ModuleName;
1752          ModuleBuildFailed = true;
1753          KnownModules[Path[0].first] = nullptr;
1754          return ModuleLoadResult();
1755        }
1756      }
1757      break;
1758    }
1759
1760    case ASTReader::OutOfDate:
1761    case ASTReader::Missing: {
1762      if (Source != ModuleCache) {
1763        // We don't know the desired configuration for this module and don't
1764        // necessarily even have a module map. Since ReadAST already produces
1765        // diagnostics for these two cases, we simply error out here.
1766        ModuleBuildFailed = true;
1767        KnownModules[Path[0].first] = nullptr;
1768        return ModuleLoadResult();
1769      }
1770
1771      // The module file is missing or out-of-date. Build it.
1772      assert(Module && "missing module file");
1773      // Check whether there is a cycle in the module graph.
1774      ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1775      ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1776      for (; Pos != PosEnd; ++Pos) {
1777        if (Pos->first == ModuleName)
1778          break;
1779      }
1780
1781      if (Pos != PosEnd) {
1782        SmallString<256> CyclePath;
1783        for (; Pos != PosEnd; ++Pos) {
1784          CyclePath += Pos->first;
1785          CyclePath += " -> ";
1786        }
1787        CyclePath += ModuleName;
1788
1789        getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1790          << ModuleName << CyclePath;
1791        return ModuleLoadResult();
1792      }
1793
1794      // Check whether we have already attempted to build this module (but
1795      // failed).
1796      if (getPreprocessorOpts().FailedModules &&
1797          getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1798        getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1799          << ModuleName
1800          << SourceRange(ImportLoc, ModuleNameLoc);
1801        ModuleBuildFailed = true;
1802        return ModuleLoadResult();
1803      }
1804
1805      // Try to compile and then load the module.
1806      if (!compileAndLoadModule(*this, ImportLoc, ModuleNameLoc, Module,
1807                                ModuleFileName)) {
1808        assert(getDiagnostics().hasErrorOccurred() &&
1809               "undiagnosed error in compileAndLoadModule");
1810        if (getPreprocessorOpts().FailedModules)
1811          getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1812        KnownModules[Path[0].first] = nullptr;
1813        ModuleBuildFailed = true;
1814        return ModuleLoadResult();
1815      }
1816
1817      // Okay, we've rebuilt and now loaded the module.
1818      break;
1819    }
1820
1821    case ASTReader::ConfigurationMismatch:
1822      if (Source == PrebuiltModulePath)
1823        // FIXME: We shouldn't be setting HadFatalFailure below if we only
1824        // produce a warning here!
1825        getDiagnostics().Report(SourceLocation(),
1826                                diag::warn_module_config_mismatch)
1827            << ModuleFileName;
1828      // Fall through to error out.
1829      LLVM_FALLTHROUGH;
1830    case ASTReader::VersionMismatch:
1831    case ASTReader::HadErrors:
1832      ModuleLoader::HadFatalFailure = true;
1833      // FIXME: The ASTReader will already have complained, but can we shoehorn
1834      // that diagnostic information into a more useful form?
1835      KnownModules[Path[0].first] = nullptr;
1836      return ModuleLoadResult();
1837
1838    case ASTReader::Failure:
1839      ModuleLoader::HadFatalFailure = true;
1840      // Already complained, but note now that we failed.
1841      KnownModules[Path[0].first] = nullptr;
1842      ModuleBuildFailed = true;
1843      return ModuleLoadResult();
1844    }
1845
1846    // Cache the result of this top-level module lookup for later.
1847    Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
1848  }
1849
1850  // If we never found the module, fail.
1851  if (!Module)
1852    return ModuleLoadResult();
1853
1854  // Verify that the rest of the module path actually corresponds to
1855  // a submodule.
1856  bool MapPrivateSubModToTopLevel = false;
1857  if (Path.size() > 1) {
1858    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1859      StringRef Name = Path[I].first->getName();
1860      clang::Module *Sub = Module->findSubmodule(Name);
1861
1862      // If the user is requesting Foo.Private and it doesn't exist, try to
1863      // match Foo_Private and emit a warning asking for the user to write
1864      // @import Foo_Private instead. FIXME: remove this when existing clients
1865      // migrate off of Foo.Private syntax.
1866      if (!Sub && PP->getLangOpts().ImplicitModules && Name == "Private" &&
1867          Module == Module->getTopLevelModule()) {
1868        SmallString<128> PrivateModule(Module->Name);
1869        PrivateModule.append("_Private");
1870
1871        SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> PrivPath;
1872        auto &II = PP->getIdentifierTable().get(
1873            PrivateModule, PP->getIdentifierInfo(Module->Name)->getTokenID());
1874        PrivPath.push_back(std::make_pair(&II, Path[0].second));
1875
1876        if (PP->getHeaderSearchInfo().lookupModule(PrivateModule, true,
1877                                                   !IsInclusionDirective))
1878          Sub =
1879              loadModule(ImportLoc, PrivPath, Visibility, IsInclusionDirective);
1880        if (Sub) {
1881          MapPrivateSubModToTopLevel = true;
1882          if (!getDiagnostics().isIgnored(
1883                  diag::warn_no_priv_submodule_use_toplevel, ImportLoc)) {
1884            getDiagnostics().Report(Path[I].second,
1885                                    diag::warn_no_priv_submodule_use_toplevel)
1886                << Path[I].first << Module->getFullModuleName() << PrivateModule
1887                << SourceRange(Path[0].second, Path[I].second)
1888                << FixItHint::CreateReplacement(SourceRange(Path[0].second),
1889                                                PrivateModule);
1890            getDiagnostics().Report(Sub->DefinitionLoc,
1891                                    diag::note_private_top_level_defined);
1892          }
1893        }
1894      }
1895
1896      if (!Sub) {
1897        // Attempt to perform typo correction to find a module name that works.
1898        SmallVector<StringRef, 2> Best;
1899        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1900
1901        for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1902                                            JEnd = Module->submodule_end();
1903             J != JEnd; ++J) {
1904          unsigned ED = Name.edit_distance((*J)->Name,
1905                                           /*AllowReplacements=*/true,
1906                                           BestEditDistance);
1907          if (ED <= BestEditDistance) {
1908            if (ED < BestEditDistance) {
1909              Best.clear();
1910              BestEditDistance = ED;
1911            }
1912
1913            Best.push_back((*J)->Name);
1914          }
1915        }
1916
1917        // If there was a clear winner, user it.
1918        if (Best.size() == 1) {
1919          getDiagnostics().Report(Path[I].second,
1920                                  diag::err_no_submodule_suggest)
1921            << Path[I].first << Module->getFullModuleName() << Best[0]
1922            << SourceRange(Path[0].second, Path[I-1].second)
1923            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1924                                            Best[0]);
1925
1926          Sub = Module->findSubmodule(Best[0]);
1927        }
1928      }
1929
1930      if (!Sub) {
1931        // No submodule by this name. Complain, and don't look for further
1932        // submodules.
1933        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1934          << Path[I].first << Module->getFullModuleName()
1935          << SourceRange(Path[0].second, Path[I-1].second);
1936        break;
1937      }
1938
1939      Module = Sub;
1940    }
1941  }
1942
1943  // Make the named module visible, if it's not already part of the module
1944  // we are parsing.
1945  if (ModuleName != getLangOpts().CurrentModule) {
1946    if (!Module->IsFromModuleFile && !MapPrivateSubModToTopLevel) {
1947      // We have an umbrella header or directory that doesn't actually include
1948      // all of the headers within the directory it covers. Complain about
1949      // this missing submodule and recover by forgetting that we ever saw
1950      // this submodule.
1951      // FIXME: Should we detect this at module load time? It seems fairly
1952      // expensive (and rare).
1953      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1954        << Module->getFullModuleName()
1955        << SourceRange(Path.front().second, Path.back().second);
1956
1957      return ModuleLoadResult::MissingExpected;
1958    }
1959
1960    // Check whether this module is available.
1961    if (Preprocessor::checkModuleIsAvailable(getLangOpts(), getTarget(),
1962                                             getDiagnostics(), Module)) {
1963      getDiagnostics().Report(ImportLoc, diag::note_module_import_here)
1964        << SourceRange(Path.front().second, Path.back().second);
1965      LastModuleImportLoc = ImportLoc;
1966      LastModuleImportResult = ModuleLoadResult();
1967      return ModuleLoadResult();
1968    }
1969
1970    ModuleManager->makeModuleVisible(Module, Visibility, ImportLoc);
1971  }
1972
1973  // Check for any configuration macros that have changed.
1974  clang::Module *TopModule = Module->getTopLevelModule();
1975  for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
1976    checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
1977                     Module, ImportLoc);
1978  }
1979
1980  // Resolve any remaining module using export_as for this one.
1981  getPreprocessor()
1982      .getHeaderSearchInfo()
1983      .getModuleMap()
1984      .resolveLinkAsDependencies(TopModule);
1985
1986  LastModuleImportLoc = ImportLoc;
1987  LastModuleImportResult = ModuleLoadResult(Module);
1988  return LastModuleImportResult;
1989}
1990
1991void CompilerInstance::loadModuleFromSource(SourceLocation ImportLoc,
1992                                            StringRef ModuleName,
1993                                            StringRef Source) {
1994  // Avoid creating filenames with special characters.
1995  SmallString<128> CleanModuleName(ModuleName);
1996  for (auto &C : CleanModuleName)
1997    if (!isAlphanumeric(C))
1998      C = '_';
1999
2000  // FIXME: Using a randomized filename here means that our intermediate .pcm
2001  // output is nondeterministic (as .pcm files refer to each other by name).
2002  // Can this affect the output in any way?
2003  SmallString<128> ModuleFileName;
2004  if (std::error_code EC = llvm::sys::fs::createTemporaryFile(
2005          CleanModuleName, "pcm", ModuleFileName)) {
2006    getDiagnostics().Report(ImportLoc, diag::err_fe_unable_to_open_output)
2007        << ModuleFileName << EC.message();
2008    return;
2009  }
2010  std::string ModuleMapFileName = (CleanModuleName + ".map").str();
2011
2012  FrontendInputFile Input(
2013      ModuleMapFileName,
2014      InputKind(getLanguageFromOptions(*Invocation->getLangOpts()),
2015                InputKind::ModuleMap, /*Preprocessed*/true));
2016
2017  std::string NullTerminatedSource(Source.str());
2018
2019  auto PreBuildStep = [&](CompilerInstance &Other) {
2020    // Create a virtual file containing our desired source.
2021    // FIXME: We shouldn't need to do this.
2022    const FileEntry *ModuleMapFile = Other.getFileManager().getVirtualFile(
2023        ModuleMapFileName, NullTerminatedSource.size(), 0);
2024    Other.getSourceManager().overrideFileContents(
2025        ModuleMapFile,
2026        llvm::MemoryBuffer::getMemBuffer(NullTerminatedSource.c_str()));
2027
2028    Other.BuiltModules = std::move(BuiltModules);
2029    Other.DeleteBuiltModules = false;
2030  };
2031
2032  auto PostBuildStep = [this](CompilerInstance &Other) {
2033    BuiltModules = std::move(Other.BuiltModules);
2034  };
2035
2036  // Build the module, inheriting any modules that we've built locally.
2037  if (compileModuleImpl(*this, ImportLoc, ModuleName, Input, StringRef(),
2038                        ModuleFileName, PreBuildStep, PostBuildStep)) {
2039    BuiltModules[ModuleName] = ModuleFileName.str();
2040    llvm::sys::RemoveFileOnSignal(ModuleFileName);
2041  }
2042}
2043
2044void CompilerInstance::makeModuleVisible(Module *Mod,
2045                                         Module::NameVisibilityKind Visibility,
2046                                         SourceLocation ImportLoc) {
2047  if (!ModuleManager)
2048    createModuleManager();
2049  if (!ModuleManager)
2050    return;
2051
2052  ModuleManager->makeModuleVisible(Mod, Visibility, ImportLoc);
2053}
2054
2055GlobalModuleIndex *CompilerInstance::loadGlobalModuleIndex(
2056    SourceLocation TriggerLoc) {
2057  if (getPreprocessor().getHeaderSearchInfo().getModuleCachePath().empty())
2058    return nullptr;
2059  if (!ModuleManager)
2060    createModuleManager();
2061  // Can't do anything if we don't have the module manager.
2062  if (!ModuleManager)
2063    return nullptr;
2064  // Get an existing global index.  This loads it if not already
2065  // loaded.
2066  ModuleManager->loadGlobalIndex();
2067  GlobalModuleIndex *GlobalIndex = ModuleManager->getGlobalIndex();
2068  // If the global index doesn't exist, create it.
2069  if (!GlobalIndex && shouldBuildGlobalModuleIndex() && hasFileManager() &&
2070      hasPreprocessor()) {
2071    llvm::sys::fs::create_directories(
2072      getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
2073    if (llvm::Error Err = GlobalModuleIndex::writeIndex(
2074            getFileManager(), getPCHContainerReader(),
2075            getPreprocessor().getHeaderSearchInfo().getModuleCachePath())) {
2076      // FIXME this drops the error on the floor. This code is only used for
2077      // typo correction and drops more than just this one source of errors
2078      // (such as the directory creation failure above). It should handle the
2079      // error.
2080      consumeError(std::move(Err));
2081      return nullptr;
2082    }
2083    ModuleManager->resetForReload();
2084    ModuleManager->loadGlobalIndex();
2085    GlobalIndex = ModuleManager->getGlobalIndex();
2086  }
2087  // For finding modules needing to be imported for fixit messages,
2088  // we need to make the global index cover all modules, so we do that here.
2089  if (!HaveFullGlobalModuleIndex && GlobalIndex && !buildingModule()) {
2090    ModuleMap &MMap = getPreprocessor().getHeaderSearchInfo().getModuleMap();
2091    bool RecreateIndex = false;
2092    for (ModuleMap::module_iterator I = MMap.module_begin(),
2093        E = MMap.module_end(); I != E; ++I) {
2094      Module *TheModule = I->second;
2095      const FileEntry *Entry = TheModule->getASTFile();
2096      if (!Entry) {
2097        SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
2098        Path.push_back(std::make_pair(
2099            getPreprocessor().getIdentifierInfo(TheModule->Name), TriggerLoc));
2100        std::reverse(Path.begin(), Path.end());
2101        // Load a module as hidden.  This also adds it to the global index.
2102        loadModule(TheModule->DefinitionLoc, Path, Module::Hidden, false);
2103        RecreateIndex = true;
2104      }
2105    }
2106    if (RecreateIndex) {
2107      if (llvm::Error Err = GlobalModuleIndex::writeIndex(
2108              getFileManager(), getPCHContainerReader(),
2109              getPreprocessor().getHeaderSearchInfo().getModuleCachePath())) {
2110        // FIXME As above, this drops the error on the floor.
2111        consumeError(std::move(Err));
2112        return nullptr;
2113      }
2114      ModuleManager->resetForReload();
2115      ModuleManager->loadGlobalIndex();
2116      GlobalIndex = ModuleManager->getGlobalIndex();
2117    }
2118    HaveFullGlobalModuleIndex = true;
2119  }
2120  return GlobalIndex;
2121}
2122
2123// Check global module index for missing imports.
2124bool
2125CompilerInstance::lookupMissingImports(StringRef Name,
2126                                       SourceLocation TriggerLoc) {
2127  // Look for the symbol in non-imported modules, but only if an error
2128  // actually occurred.
2129  if (!buildingModule()) {
2130    // Load global module index, or retrieve a previously loaded one.
2131    GlobalModuleIndex *GlobalIndex = loadGlobalModuleIndex(
2132      TriggerLoc);
2133
2134    // Only if we have a global index.
2135    if (GlobalIndex) {
2136      GlobalModuleIndex::HitSet FoundModules;
2137
2138      // Find the modules that reference the identifier.
2139      // Note that this only finds top-level modules.
2140      // We'll let diagnoseTypo find the actual declaration module.
2141      if (GlobalIndex->lookupIdentifier(Name, FoundModules))
2142        return true;
2143    }
2144  }
2145
2146  return false;
2147}
2148void CompilerInstance::resetAndLeakSema() { llvm::BuryPointer(takeSema()); }
2149
2150void CompilerInstance::setExternalSemaSource(
2151    IntrusiveRefCntPtr<ExternalSemaSource> ESS) {
2152  ExternalSemaSrc = std::move(ESS);
2153}
2154