CompilerInstance.cpp revision 360784 
1//===--- CompilerInstance.cpp ---------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "clang/Frontend/CompilerInstance.h"
10#include "clang/AST/ASTConsumer.h"
11#include "clang/AST/ASTContext.h"
12#include "clang/AST/Decl.h"
13#include "clang/Basic/CharInfo.h"
14#include "clang/Basic/Diagnostic.h"
15#include "clang/Basic/FileManager.h"
16#include "clang/Basic/LangStandard.h"
17#include "clang/Basic/SourceManager.h"
18#include "clang/Basic/Stack.h"
19#include "clang/Basic/TargetInfo.h"
20#include "clang/Basic/Version.h"
21#include "clang/Config/config.h"
22#include "clang/Frontend/ChainedDiagnosticConsumer.h"
23#include "clang/Frontend/FrontendAction.h"
24#include "clang/Frontend/FrontendActions.h"
25#include "clang/Frontend/FrontendDiagnostic.h"
26#include "clang/Frontend/LogDiagnosticPrinter.h"
27#include "clang/Frontend/SerializedDiagnosticPrinter.h"
28#include "clang/Frontend/TextDiagnosticPrinter.h"
29#include "clang/Frontend/Utils.h"
30#include "clang/Frontend/VerifyDiagnosticConsumer.h"
31#include "clang/Lex/HeaderSearch.h"
32#include "clang/Lex/Preprocessor.h"
33#include "clang/Lex/PreprocessorOptions.h"
34#include "clang/Sema/CodeCompleteConsumer.h"
35#include "clang/Sema/Sema.h"
36#include "clang/Serialization/ASTReader.h"
37#include "clang/Serialization/GlobalModuleIndex.h"
38#include "clang/Serialization/InMemoryModuleCache.h"
39#include "llvm/ADT/Statistic.h"
40#include "llvm/Support/BuryPointer.h"
41#include "llvm/Support/CrashRecoveryContext.h"
42#include "llvm/Support/Errc.h"
43#include "llvm/Support/FileSystem.h"
44#include "llvm/Support/Host.h"
45#include "llvm/Support/LockFileManager.h"
46#include "llvm/Support/MemoryBuffer.h"
47#include "llvm/Support/Path.h"
48#include "llvm/Support/Program.h"
49#include "llvm/Support/Signals.h"
50#include "llvm/Support/TimeProfiler.h"
51#include "llvm/Support/Timer.h"
52#include "llvm/Support/raw_ostream.h"
53#include <time.h>
54#include <utility>
55
56using namespace clang;
57
58CompilerInstance::CompilerInstance(
59    std::shared_ptr<PCHContainerOperations> PCHContainerOps,
60    InMemoryModuleCache *SharedModuleCache)
61    : ModuleLoader(/* BuildingModule = */ SharedModuleCache),
62      Invocation(new CompilerInvocation()),
63      ModuleCache(SharedModuleCache ? SharedModuleCache
64                                    : new InMemoryModuleCache),
65      ThePCHContainerOperations(std::move(PCHContainerOps)) {}
66
67CompilerInstance::~CompilerInstance() {
68  assert(OutputFiles.empty() && "Still output files in flight?");
69}
70
71void CompilerInstance::setInvocation(
72    std::shared_ptr<CompilerInvocation> Value) {
73  Invocation = std::move(Value);
74}
75
76bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
77  return (BuildGlobalModuleIndex ||
78          (TheASTReader && TheASTReader->isGlobalIndexUnavailable() &&
79           getFrontendOpts().GenerateGlobalModuleIndex)) &&
80         !ModuleBuildFailed;
81}
82
83void CompilerInstance::setDiagnostics(DiagnosticsEngine *Value) {
84  Diagnostics = Value;
85}
86
87void CompilerInstance::setVerboseOutputStream(raw_ostream &Value) {
88  OwnedVerboseOutputStream.release();
89  VerboseOutputStream = &Value;
90}
91
92void CompilerInstance::setVerboseOutputStream(std::unique_ptr<raw_ostream> Value) {
93  OwnedVerboseOutputStream.swap(Value);
94  VerboseOutputStream = OwnedVerboseOutputStream.get();
95}
96
97void CompilerInstance::setTarget(TargetInfo *Value) { Target = Value; }
98void CompilerInstance::setAuxTarget(TargetInfo *Value) { AuxTarget = Value; }
99
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::getASTReader() const {
139  return TheASTReader;
140}
141void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
142  assert(ModuleCache.get() == &Reader->getModuleManager().getModuleCache() &&
143         "Expected ASTReader to use the same PCM cache");
144  TheASTReader = 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  TheASTReader.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  TheASTReader = 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                          getFrontendOpts().UseTemporary);
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/OpenMP/SYCL compilation.
921  if ((getLangOpts().CUDA || getLangOpts().OpenMPIsDevice ||
922       getLangOpts().SYCLIsDevice) &&
923      !getFrontendOpts().AuxTriple.empty()) {
924    auto TO = std::make_shared<TargetOptions>();
925    TO->Triple = llvm::Triple::normalize(getFrontendOpts().AuxTriple);
926    TO->HostTriple = getTarget().getTriple().str();
927    setAuxTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), TO));
928  }
929
930  // Inform the target of the language options.
931  //
932  // FIXME: We shouldn't need to do this, the target should be immutable once
933  // created. This complexity should be lifted elsewhere.
934  getTarget().adjust(getLangOpts());
935
936  // Adjust target options based on codegen options.
937  getTarget().adjustTargetOptions(getCodeGenOpts(), getTargetOpts());
938
939  if (auto *Aux = getAuxTarget())
940    getTarget().setAuxTarget(Aux);
941
942  // rewriter project will change target built-in bool type from its default.
943  if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
944    getTarget().noSignedCharForObjCBool();
945
946  // Validate/process some options.
947  if (getHeaderSearchOpts().Verbose)
948    OS << "clang -cc1 version " CLANG_VERSION_STRING
949       << " based upon " << BACKEND_PACKAGE_STRING
950       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
951
952  if (getFrontendOpts().ShowTimers)
953    createFrontendTimer();
954
955  if (getFrontendOpts().ShowStats || !getFrontendOpts().StatsFile.empty())
956    llvm::EnableStatistics(false);
957
958  for (const FrontendInputFile &FIF : getFrontendOpts().Inputs) {
959    // Reset the ID tables if we are reusing the SourceManager and parsing
960    // regular files.
961    if (hasSourceManager() && !Act.isModelParsingAction())
962      getSourceManager().clearIDTables();
963
964    if (Act.BeginSourceFile(*this, FIF)) {
965      if (llvm::Error Err = Act.Execute()) {
966        consumeError(std::move(Err)); // FIXME this drops errors on the floor.
967      }
968      Act.EndSourceFile();
969    }
970  }
971
972  // Notify the diagnostic client that all files were processed.
973  getDiagnostics().getClient()->finish();
974
975  if (getDiagnosticOpts().ShowCarets) {
976    // We can have multiple diagnostics sharing one diagnostic client.
977    // Get the total number of warnings/errors from the client.
978    unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
979    unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
980
981    if (NumWarnings)
982      OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
983    if (NumWarnings && NumErrors)
984      OS << " and ";
985    if (NumErrors)
986      OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
987    if (NumWarnings || NumErrors) {
988      OS << " generated";
989      if (getLangOpts().CUDA) {
990        if (!getLangOpts().CUDAIsDevice) {
991          OS << " when compiling for host";
992        } else {
993          OS << " when compiling for " << getTargetOpts().CPU;
994        }
995      }
996      OS << ".\n";
997    }
998  }
999
1000  if (getFrontendOpts().ShowStats) {
1001    if (hasFileManager()) {
1002      getFileManager().PrintStats();
1003      OS << '\n';
1004    }
1005    llvm::PrintStatistics(OS);
1006  }
1007  StringRef StatsFile = getFrontendOpts().StatsFile;
1008  if (!StatsFile.empty()) {
1009    std::error_code EC;
1010    auto StatS = std::make_unique<llvm::raw_fd_ostream>(
1011        StatsFile, EC, llvm::sys::fs::OF_Text);
1012    if (EC) {
1013      getDiagnostics().Report(diag::warn_fe_unable_to_open_stats_file)
1014          << StatsFile << EC.message();
1015    } else {
1016      llvm::PrintStatisticsJSON(*StatS);
1017    }
1018  }
1019
1020  return !getDiagnostics().getClient()->getNumErrors();
1021}
1022
1023/// Determine the appropriate source input kind based on language
1024/// options.
1025static Language getLanguageFromOptions(const LangOptions &LangOpts) {
1026  if (LangOpts.OpenCL)
1027    return Language::OpenCL;
1028  if (LangOpts.CUDA)
1029    return Language::CUDA;
1030  if (LangOpts.ObjC)
1031    return LangOpts.CPlusPlus ? Language::ObjCXX : Language::ObjC;
1032  return LangOpts.CPlusPlus ? Language::CXX : Language::C;
1033}
1034
1035/// Compile a module file for the given module, using the options
1036/// provided by the importing compiler instance. Returns true if the module
1037/// was built without errors.
1038static bool
1039compileModuleImpl(CompilerInstance &ImportingInstance, SourceLocation ImportLoc,
1040                  StringRef ModuleName, FrontendInputFile Input,
1041                  StringRef OriginalModuleMapFile, StringRef ModuleFileName,
1042                  llvm::function_ref<void(CompilerInstance &)> PreBuildStep =
1043                      [](CompilerInstance &) {},
1044                  llvm::function_ref<void(CompilerInstance &)> PostBuildStep =
1045                      [](CompilerInstance &) {}) {
1046  llvm::TimeTraceScope TimeScope("Module Compile", ModuleName);
1047
1048  // Construct a compiler invocation for creating this module.
1049  auto Invocation =
1050      std::make_shared<CompilerInvocation>(ImportingInstance.getInvocation());
1051
1052  PreprocessorOptions &PPOpts = Invocation->getPreprocessorOpts();
1053
1054  // For any options that aren't intended to affect how a module is built,
1055  // reset them to their default values.
1056  Invocation->getLangOpts()->resetNonModularOptions();
1057  PPOpts.resetNonModularOptions();
1058
1059  // Remove any macro definitions that are explicitly ignored by the module.
1060  // They aren't supposed to affect how the module is built anyway.
1061  HeaderSearchOptions &HSOpts = Invocation->getHeaderSearchOpts();
1062  PPOpts.Macros.erase(
1063      std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
1064                     [&HSOpts](const std::pair<std::string, bool> &def) {
1065        StringRef MacroDef = def.first;
1066        return HSOpts.ModulesIgnoreMacros.count(
1067                   llvm::CachedHashString(MacroDef.split('=').first)) > 0;
1068      }),
1069      PPOpts.Macros.end());
1070
1071  // If the original compiler invocation had -fmodule-name, pass it through.
1072  Invocation->getLangOpts()->ModuleName =
1073      ImportingInstance.getInvocation().getLangOpts()->ModuleName;
1074
1075  // Note the name of the module we're building.
1076  Invocation->getLangOpts()->CurrentModule = ModuleName;
1077
1078  // Make sure that the failed-module structure has been allocated in
1079  // the importing instance, and propagate the pointer to the newly-created
1080  // instance.
1081  PreprocessorOptions &ImportingPPOpts
1082    = ImportingInstance.getInvocation().getPreprocessorOpts();
1083  if (!ImportingPPOpts.FailedModules)
1084    ImportingPPOpts.FailedModules =
1085        std::make_shared<PreprocessorOptions::FailedModulesSet>();
1086  PPOpts.FailedModules = ImportingPPOpts.FailedModules;
1087
1088  // If there is a module map file, build the module using the module map.
1089  // Set up the inputs/outputs so that we build the module from its umbrella
1090  // header.
1091  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
1092  FrontendOpts.OutputFile = ModuleFileName.str();
1093  FrontendOpts.DisableFree = false;
1094  FrontendOpts.GenerateGlobalModuleIndex = false;
1095  FrontendOpts.BuildingImplicitModule = true;
1096  FrontendOpts.OriginalModuleMap = OriginalModuleMapFile;
1097  // Force implicitly-built modules to hash the content of the module file.
1098  HSOpts.ModulesHashContent = true;
1099  FrontendOpts.Inputs = {Input};
1100
1101  // Don't free the remapped file buffers; they are owned by our caller.
1102  PPOpts.RetainRemappedFileBuffers = true;
1103
1104  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
1105  assert(ImportingInstance.getInvocation().getModuleHash() ==
1106         Invocation->getModuleHash() && "Module hash mismatch!");
1107
1108  // Construct a compiler instance that will be used to actually create the
1109  // module.  Since we're sharing an in-memory module cache,
1110  // CompilerInstance::CompilerInstance is responsible for finalizing the
1111  // buffers to prevent use-after-frees.
1112  CompilerInstance Instance(ImportingInstance.getPCHContainerOperations(),
1113                            &ImportingInstance.getModuleCache());
1114  auto &Inv = *Invocation;
1115  Instance.setInvocation(std::move(Invocation));
1116
1117  Instance.createDiagnostics(new ForwardingDiagnosticConsumer(
1118                                   ImportingInstance.getDiagnosticClient()),
1119                             /*ShouldOwnClient=*/true);
1120
1121  // Note that this module is part of the module build stack, so that we
1122  // can detect cycles in the module graph.
1123  Instance.setFileManager(&ImportingInstance.getFileManager());
1124  Instance.createSourceManager(Instance.getFileManager());
1125  SourceManager &SourceMgr = Instance.getSourceManager();
1126  SourceMgr.setModuleBuildStack(
1127    ImportingInstance.getSourceManager().getModuleBuildStack());
1128  SourceMgr.pushModuleBuildStack(ModuleName,
1129    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
1130
1131  // If we're collecting module dependencies, we need to share a collector
1132  // between all of the module CompilerInstances. Other than that, we don't
1133  // want to produce any dependency output from the module build.
1134  Instance.setModuleDepCollector(ImportingInstance.getModuleDepCollector());
1135  Inv.getDependencyOutputOpts() = DependencyOutputOptions();
1136
1137  ImportingInstance.getDiagnostics().Report(ImportLoc,
1138                                            diag::remark_module_build)
1139    << ModuleName << ModuleFileName;
1140
1141  PreBuildStep(Instance);
1142
1143  // Execute the action to actually build the module in-place. Use a separate
1144  // thread so that we get a stack large enough.
1145  llvm::CrashRecoveryContext CRC;
1146  CRC.RunSafelyOnThread(
1147      [&]() {
1148        GenerateModuleFromModuleMapAction Action;
1149        Instance.ExecuteAction(Action);
1150      },
1151      DesiredStackSize);
1152
1153  PostBuildStep(Instance);
1154
1155  ImportingInstance.getDiagnostics().Report(ImportLoc,
1156                                            diag::remark_module_build_done)
1157    << ModuleName;
1158
1159  // Delete the temporary module map file.
1160  // FIXME: Even though we're executing under crash protection, it would still
1161  // be nice to do this with RemoveFileOnSignal when we can. However, that
1162  // doesn't make sense for all clients, so clean this up manually.
1163  Instance.clearOutputFiles(/*EraseFiles=*/true);
1164
1165  return !Instance.getDiagnostics().hasErrorOccurred();
1166}
1167
1168static const FileEntry *getPublicModuleMap(const FileEntry *File,
1169                                           FileManager &FileMgr) {
1170  StringRef Filename = llvm::sys::path::filename(File->getName());
1171  SmallString<128> PublicFilename(File->getDir()->getName());
1172  if (Filename == "module_private.map")
1173    llvm::sys::path::append(PublicFilename, "module.map");
1174  else if (Filename == "module.private.modulemap")
1175    llvm::sys::path::append(PublicFilename, "module.modulemap");
1176  else
1177    return nullptr;
1178  if (auto FE = FileMgr.getFile(PublicFilename))
1179    return *FE;
1180  return nullptr;
1181}
1182
1183/// Compile a module file for the given module in a separate compiler instance,
1184/// using the options provided by the importing compiler instance. Returns true
1185/// if the module was built without errors.
1186static bool compileModule(CompilerInstance &ImportingInstance,
1187                          SourceLocation ImportLoc, 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
1248/// Compile a module in a separate compiler instance and read the AST,
1249/// returning true if the module compiles without errors.
1250///
1251/// Uses a lock file manager and exponential backoff to reduce the chances that
1252/// multiple instances will compete to create the same module.  On timeout,
1253/// deletes the lock file in order to avoid deadlock from crashing processes or
1254/// bugs in the lock file manager.
1255static bool compileModuleAndReadAST(CompilerInstance &ImportingInstance,
1256                                    SourceLocation ImportLoc,
1257                                    SourceLocation ModuleNameLoc,
1258                                    Module *Module, StringRef ModuleFileName) {
1259  DiagnosticsEngine &Diags = ImportingInstance.getDiagnostics();
1260
1261  auto diagnoseBuildFailure = [&] {
1262    Diags.Report(ModuleNameLoc, diag::err_module_not_built)
1263        << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
1264  };
1265
1266  // FIXME: have LockFileManager return an error_code so that we can
1267  // avoid the mkdir when the directory already exists.
1268  StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
1269  llvm::sys::fs::create_directories(Dir);
1270
1271  while (1) {
1272    unsigned ModuleLoadCapabilities = ASTReader::ARR_Missing;
1273    llvm::LockFileManager Locked(ModuleFileName);
1274    switch (Locked) {
1275    case llvm::LockFileManager::LFS_Error:
1276      // ModuleCache takes care of correctness and locks are only necessary for
1277      // performance. Fallback to building the module in case of any lock
1278      // related errors.
1279      Diags.Report(ModuleNameLoc, diag::remark_module_lock_failure)
1280          << Module->Name << Locked.getErrorMessage();
1281      // Clear out any potential leftover.
1282      Locked.unsafeRemoveLockFile();
1283      LLVM_FALLTHROUGH;
1284    case llvm::LockFileManager::LFS_Owned:
1285      // We're responsible for building the module ourselves.
1286      if (!compileModule(ImportingInstance, ModuleNameLoc, Module,
1287                         ModuleFileName)) {
1288        diagnoseBuildFailure();
1289        return false;
1290      }
1291      break;
1292
1293    case llvm::LockFileManager::LFS_Shared:
1294      // Someone else is responsible for building the module. Wait for them to
1295      // finish.
1296      switch (Locked.waitForUnlock()) {
1297      case llvm::LockFileManager::Res_Success:
1298        ModuleLoadCapabilities |= ASTReader::ARR_OutOfDate;
1299        break;
1300      case llvm::LockFileManager::Res_OwnerDied:
1301        continue; // try again to get the lock.
1302      case llvm::LockFileManager::Res_Timeout:
1303        // Since ModuleCache takes care of correctness, we try waiting for
1304        // another process to complete the build so clang does not do it done
1305        // twice. If case of timeout, build it ourselves.
1306        Diags.Report(ModuleNameLoc, diag::remark_module_lock_timeout)
1307            << Module->Name;
1308        // Clear the lock file so that future invocations can make progress.
1309        Locked.unsafeRemoveLockFile();
1310        continue;
1311      }
1312      break;
1313    }
1314
1315    // Try to read the module file, now that we've compiled it.
1316    ASTReader::ASTReadResult ReadResult =
1317        ImportingInstance.getASTReader()->ReadAST(
1318            ModuleFileName, serialization::MK_ImplicitModule, ImportLoc,
1319            ModuleLoadCapabilities);
1320
1321    if (ReadResult == ASTReader::OutOfDate &&
1322        Locked == llvm::LockFileManager::LFS_Shared) {
1323      // The module may be out of date in the presence of file system races,
1324      // or if one of its imports depends on header search paths that are not
1325      // consistent with this ImportingInstance.  Try again...
1326      continue;
1327    } else if (ReadResult == ASTReader::Missing) {
1328      diagnoseBuildFailure();
1329    } else if (ReadResult != ASTReader::Success &&
1330               !Diags.hasErrorOccurred()) {
1331      // The ASTReader didn't diagnose the error, so conservatively report it.
1332      diagnoseBuildFailure();
1333    }
1334    return ReadResult == ASTReader::Success;
1335  }
1336}
1337
1338/// Diagnose differences between the current definition of the given
1339/// configuration macro and the definition provided on the command line.
1340static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro,
1341                             Module *Mod, SourceLocation ImportLoc) {
1342  IdentifierInfo *Id = PP.getIdentifierInfo(ConfigMacro);
1343  SourceManager &SourceMgr = PP.getSourceManager();
1344
1345  // If this identifier has never had a macro definition, then it could
1346  // not have changed.
1347  if (!Id->hadMacroDefinition())
1348    return;
1349  auto *LatestLocalMD = PP.getLocalMacroDirectiveHistory(Id);
1350
1351  // Find the macro definition from the command line.
1352  MacroInfo *CmdLineDefinition = nullptr;
1353  for (auto *MD = LatestLocalMD; MD; MD = MD->getPrevious()) {
1354    // We only care about the predefines buffer.
1355    FileID FID = SourceMgr.getFileID(MD->getLocation());
1356    if (FID.isInvalid() || FID != PP.getPredefinesFileID())
1357      continue;
1358    if (auto *DMD = dyn_cast<DefMacroDirective>(MD))
1359      CmdLineDefinition = DMD->getMacroInfo();
1360    break;
1361  }
1362
1363  auto *CurrentDefinition = PP.getMacroInfo(Id);
1364  if (CurrentDefinition == CmdLineDefinition) {
1365    // Macro matches. Nothing to do.
1366  } else if (!CurrentDefinition) {
1367    // This macro was defined on the command line, then #undef'd later.
1368    // Complain.
1369    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1370      << true << ConfigMacro << Mod->getFullModuleName();
1371    auto LatestDef = LatestLocalMD->getDefinition();
1372    assert(LatestDef.isUndefined() &&
1373           "predefined macro went away with no #undef?");
1374    PP.Diag(LatestDef.getUndefLocation(), diag::note_module_def_undef_here)
1375      << true;
1376    return;
1377  } else if (!CmdLineDefinition) {
1378    // There was no definition for this macro in the predefines buffer,
1379    // but there was a local definition. Complain.
1380    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1381      << false << ConfigMacro << Mod->getFullModuleName();
1382    PP.Diag(CurrentDefinition->getDefinitionLoc(),
1383            diag::note_module_def_undef_here)
1384      << false;
1385  } else if (!CurrentDefinition->isIdenticalTo(*CmdLineDefinition, PP,
1386                                               /*Syntactically=*/true)) {
1387    // The macro definitions differ.
1388    PP.Diag(ImportLoc, diag::warn_module_config_macro_undef)
1389      << false << ConfigMacro << Mod->getFullModuleName();
1390    PP.Diag(CurrentDefinition->getDefinitionLoc(),
1391            diag::note_module_def_undef_here)
1392      << false;
1393  }
1394}
1395
1396/// Write a new timestamp file with the given path.
1397static void writeTimestampFile(StringRef TimestampFile) {
1398  std::error_code EC;
1399  llvm::raw_fd_ostream Out(TimestampFile.str(), EC, llvm::sys::fs::OF_None);
1400}
1401
1402/// Prune the module cache of modules that haven't been accessed in
1403/// a long time.
1404static void pruneModuleCache(const HeaderSearchOptions &HSOpts) {
1405  llvm::sys::fs::file_status StatBuf;
1406  llvm::SmallString<128> TimestampFile;
1407  TimestampFile = HSOpts.ModuleCachePath;
1408  assert(!TimestampFile.empty());
1409  llvm::sys::path::append(TimestampFile, "modules.timestamp");
1410
1411  // Try to stat() the timestamp file.
1412  if (std::error_code EC = llvm::sys::fs::status(TimestampFile, StatBuf)) {
1413    // If the timestamp file wasn't there, create one now.
1414    if (EC == std::errc::no_such_file_or_directory) {
1415      writeTimestampFile(TimestampFile);
1416    }
1417    return;
1418  }
1419
1420  // Check whether the time stamp is older than our pruning interval.
1421  // If not, do nothing.
1422  time_t TimeStampModTime =
1423      llvm::sys::toTimeT(StatBuf.getLastModificationTime());
1424  time_t CurrentTime = time(nullptr);
1425  if (CurrentTime - TimeStampModTime <= time_t(HSOpts.ModuleCachePruneInterval))
1426    return;
1427
1428  // Write a new timestamp file so that nobody else attempts to prune.
1429  // There is a benign race condition here, if two Clang instances happen to
1430  // notice at the same time that the timestamp is out-of-date.
1431  writeTimestampFile(TimestampFile);
1432
1433  // Walk the entire module cache, looking for unused module files and module
1434  // indices.
1435  std::error_code EC;
1436  SmallString<128> ModuleCachePathNative;
1437  llvm::sys::path::native(HSOpts.ModuleCachePath, ModuleCachePathNative);
1438  for (llvm::sys::fs::directory_iterator Dir(ModuleCachePathNative, EC), DirEnd;
1439       Dir != DirEnd && !EC; Dir.increment(EC)) {
1440    // If we don't have a directory, there's nothing to look into.
1441    if (!llvm::sys::fs::is_directory(Dir->path()))
1442      continue;
1443
1444    // Walk all of the files within this directory.
1445    for (llvm::sys::fs::directory_iterator File(Dir->path(), EC), FileEnd;
1446         File != FileEnd && !EC; File.increment(EC)) {
1447      // We only care about module and global module index files.
1448      StringRef Extension = llvm::sys::path::extension(File->path());
1449      if (Extension != ".pcm" && Extension != ".timestamp" &&
1450          llvm::sys::path::filename(File->path()) != "modules.idx")
1451        continue;
1452
1453      // Look at this file. If we can't stat it, there's nothing interesting
1454      // there.
1455      if (llvm::sys::fs::status(File->path(), StatBuf))
1456        continue;
1457
1458      // If the file has been used recently enough, leave it there.
1459      time_t FileAccessTime = llvm::sys::toTimeT(StatBuf.getLastAccessedTime());
1460      if (CurrentTime - FileAccessTime <=
1461              time_t(HSOpts.ModuleCachePruneAfter)) {
1462        continue;
1463      }
1464
1465      // Remove the file.
1466      llvm::sys::fs::remove(File->path());
1467
1468      // Remove the timestamp file.
1469      std::string TimpestampFilename = File->path() + ".timestamp";
1470      llvm::sys::fs::remove(TimpestampFilename);
1471    }
1472
1473    // If we removed all of the files in the directory, remove the directory
1474    // itself.
1475    if (llvm::sys::fs::directory_iterator(Dir->path(), EC) ==
1476            llvm::sys::fs::directory_iterator() && !EC)
1477      llvm::sys::fs::remove(Dir->path());
1478  }
1479}
1480
1481void CompilerInstance::createASTReader() {
1482  if (TheASTReader)
1483    return;
1484
1485  if (!hasASTContext())
1486    createASTContext();
1487
1488  // If we're implicitly building modules but not currently recursively
1489  // building a module, check whether we need to prune the module cache.
1490  if (getSourceManager().getModuleBuildStack().empty() &&
1491      !getPreprocessor().getHeaderSearchInfo().getModuleCachePath().empty() &&
1492      getHeaderSearchOpts().ModuleCachePruneInterval > 0 &&
1493      getHeaderSearchOpts().ModuleCachePruneAfter > 0) {
1494    pruneModuleCache(getHeaderSearchOpts());
1495  }
1496
1497  HeaderSearchOptions &HSOpts = getHeaderSearchOpts();
1498  std::string Sysroot = HSOpts.Sysroot;
1499  const PreprocessorOptions &PPOpts = getPreprocessorOpts();
1500  std::unique_ptr<llvm::Timer> ReadTimer;
1501  if (FrontendTimerGroup)
1502    ReadTimer = std::make_unique<llvm::Timer>("reading_modules",
1503                                                "Reading modules",
1504                                                *FrontendTimerGroup);
1505  TheASTReader = new ASTReader(
1506      getPreprocessor(), getModuleCache(), &getASTContext(),
1507      getPCHContainerReader(), getFrontendOpts().ModuleFileExtensions,
1508      Sysroot.empty() ? "" : Sysroot.c_str(), PPOpts.DisablePCHValidation,
1509      /*AllowASTWithCompilerErrors=*/false,
1510      /*AllowConfigurationMismatch=*/false, HSOpts.ModulesValidateSystemHeaders,
1511      HSOpts.ValidateASTInputFilesContent,
1512      getFrontendOpts().UseGlobalModuleIndex, std::move(ReadTimer));
1513  if (hasASTConsumer()) {
1514    TheASTReader->setDeserializationListener(
1515        getASTConsumer().GetASTDeserializationListener());
1516    getASTContext().setASTMutationListener(
1517      getASTConsumer().GetASTMutationListener());
1518  }
1519  getASTContext().setExternalSource(TheASTReader);
1520  if (hasSema())
1521    TheASTReader->InitializeSema(getSema());
1522  if (hasASTConsumer())
1523    TheASTReader->StartTranslationUnit(&getASTConsumer());
1524
1525  for (auto &Listener : DependencyCollectors)
1526    Listener->attachToASTReader(*TheASTReader);
1527}
1528
1529bool CompilerInstance::loadModuleFile(StringRef FileName) {
1530  llvm::Timer Timer;
1531  if (FrontendTimerGroup)
1532    Timer.init("preloading." + FileName.str(), "Preloading " + FileName.str(),
1533               *FrontendTimerGroup);
1534  llvm::TimeRegion TimeLoading(FrontendTimerGroup ? &Timer : nullptr);
1535
1536  // Helper to recursively read the module names for all modules we're adding.
1537  // We mark these as known and redirect any attempt to load that module to
1538  // the files we were handed.
1539  struct ReadModuleNames : ASTReaderListener {
1540    CompilerInstance &CI;
1541    llvm::SmallVector<IdentifierInfo*, 8> LoadedModules;
1542
1543    ReadModuleNames(CompilerInstance &CI) : CI(CI) {}
1544
1545    void ReadModuleName(StringRef ModuleName) override {
1546      LoadedModules.push_back(
1547          CI.getPreprocessor().getIdentifierInfo(ModuleName));
1548    }
1549
1550    void registerAll() {
1551      ModuleMap &MM = CI.getPreprocessor().getHeaderSearchInfo().getModuleMap();
1552      for (auto *II : LoadedModules)
1553        MM.cacheModuleLoad(*II, MM.findModule(II->getName()));
1554      LoadedModules.clear();
1555    }
1556
1557    void markAllUnavailable() {
1558      for (auto *II : LoadedModules) {
1559        if (Module *M = CI.getPreprocessor()
1560                            .getHeaderSearchInfo()
1561                            .getModuleMap()
1562                            .findModule(II->getName())) {
1563          M->HasIncompatibleModuleFile = true;
1564
1565          // Mark module as available if the only reason it was unavailable
1566          // was missing headers.
1567          SmallVector<Module *, 2> Stack;
1568          Stack.push_back(M);
1569          while (!Stack.empty()) {
1570            Module *Current = Stack.pop_back_val();
1571            if (Current->IsMissingRequirement) continue;
1572            Current->IsAvailable = true;
1573            Stack.insert(Stack.end(),
1574                         Current->submodule_begin(), Current->submodule_end());
1575          }
1576        }
1577      }
1578      LoadedModules.clear();
1579    }
1580  };
1581
1582  // If we don't already have an ASTReader, create one now.
1583  if (!TheASTReader)
1584    createASTReader();
1585
1586  // If -Wmodule-file-config-mismatch is mapped as an error or worse, allow the
1587  // ASTReader to diagnose it, since it can produce better errors that we can.
1588  bool ConfigMismatchIsRecoverable =
1589      getDiagnostics().getDiagnosticLevel(diag::warn_module_config_mismatch,
1590                                          SourceLocation())
1591        <= DiagnosticsEngine::Warning;
1592
1593  auto Listener = std::make_unique<ReadModuleNames>(*this);
1594  auto &ListenerRef = *Listener;
1595  ASTReader::ListenerScope ReadModuleNamesListener(*TheASTReader,
1596                                                   std::move(Listener));
1597
1598  // Try to load the module file.
1599  switch (TheASTReader->ReadAST(
1600      FileName, serialization::MK_ExplicitModule, SourceLocation(),
1601      ConfigMismatchIsRecoverable ? ASTReader::ARR_ConfigurationMismatch : 0)) {
1602  case ASTReader::Success:
1603    // We successfully loaded the module file; remember the set of provided
1604    // modules so that we don't try to load implicit modules for them.
1605    ListenerRef.registerAll();
1606    return true;
1607
1608  case ASTReader::ConfigurationMismatch:
1609    // Ignore unusable module files.
1610    getDiagnostics().Report(SourceLocation(), diag::warn_module_config_mismatch)
1611        << FileName;
1612    // All modules provided by any files we tried and failed to load are now
1613    // unavailable; includes of those modules should now be handled textually.
1614    ListenerRef.markAllUnavailable();
1615    return true;
1616
1617  default:
1618    return false;
1619  }
1620}
1621
1622namespace {
1623enum ModuleSource {
1624  MS_ModuleNotFound,
1625  MS_ModuleCache,
1626  MS_PrebuiltModulePath,
1627  MS_ModuleBuildPragma
1628};
1629} // end namespace
1630
1631/// Select a source for loading the named module and compute the filename to
1632/// load it from.
1633static ModuleSource
1634selectModuleSource(Module *M, StringRef ModuleName, std::string &ModuleFilename,
1635                   const std::map<std::string, std::string> &BuiltModules,
1636                   HeaderSearch &HS) {
1637  assert(ModuleFilename.empty() && "Already has a module source?");
1638
1639  // Check to see if the module has been built as part of this compilation
1640  // via a module build pragma.
1641  auto BuiltModuleIt = BuiltModules.find(ModuleName);
1642  if (BuiltModuleIt != BuiltModules.end()) {
1643    ModuleFilename = BuiltModuleIt->second;
1644    return MS_ModuleBuildPragma;
1645  }
1646
1647  // Try to load the module from the prebuilt module path.
1648  const HeaderSearchOptions &HSOpts = HS.getHeaderSearchOpts();
1649  if (!HSOpts.PrebuiltModuleFiles.empty() ||
1650      !HSOpts.PrebuiltModulePaths.empty()) {
1651    ModuleFilename = HS.getPrebuiltModuleFileName(ModuleName);
1652    if (!ModuleFilename.empty())
1653      return MS_PrebuiltModulePath;
1654  }
1655
1656  // Try to load the module from the module cache.
1657  if (M) {
1658    ModuleFilename = HS.getCachedModuleFileName(M);
1659    return MS_ModuleCache;
1660  }
1661
1662  return MS_ModuleNotFound;
1663}
1664
1665ModuleLoadResult CompilerInstance::findOrCompileModuleAndReadAST(
1666    StringRef ModuleName, SourceLocation ImportLoc,
1667    SourceLocation ModuleNameLoc, bool IsInclusionDirective) {
1668  // Search for a module with the given name.
1669  HeaderSearch &HS = PP->getHeaderSearchInfo();
1670  Module *M = HS.lookupModule(ModuleName, true, !IsInclusionDirective);
1671
1672  // Select the source and filename for loading the named module.
1673  std::string ModuleFilename;
1674  ModuleSource Source =
1675      selectModuleSource(M, ModuleName, ModuleFilename, BuiltModules, HS);
1676  if (Source == MS_ModuleNotFound) {
1677    // We can't find a module, error out here.
1678    getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1679        << ModuleName << SourceRange(ImportLoc, ModuleNameLoc);
1680    ModuleBuildFailed = true;
1681    // FIXME: Why is this not cached?
1682    return ModuleLoadResult::OtherUncachedFailure;
1683  }
1684  if (ModuleFilename.empty()) {
1685    if (M && M->HasIncompatibleModuleFile) {
1686      // We tried and failed to load a module file for this module. Fall
1687      // back to textual inclusion for its headers.
1688      return ModuleLoadResult::ConfigMismatch;
1689    }
1690
1691    getDiagnostics().Report(ModuleNameLoc, diag::err_module_build_disabled)
1692        << ModuleName;
1693    ModuleBuildFailed = true;
1694    // FIXME: Why is this not cached?
1695    return ModuleLoadResult::OtherUncachedFailure;
1696  }
1697
1698  // Create an ASTReader on demand.
1699  if (!getASTReader())
1700    createASTReader();
1701
1702  // Time how long it takes to load the module.
1703  llvm::Timer Timer;
1704  if (FrontendTimerGroup)
1705    Timer.init("loading." + ModuleFilename, "Loading " + ModuleFilename,
1706               *FrontendTimerGroup);
1707  llvm::TimeRegion TimeLoading(FrontendTimerGroup ? &Timer : nullptr);
1708  llvm::TimeTraceScope TimeScope("Module Load", ModuleName);
1709
1710  // Try to load the module file. If we are not trying to load from the
1711  // module cache, we don't know how to rebuild modules.
1712  unsigned ARRFlags = Source == MS_ModuleCache
1713                          ? ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing
1714                          : Source == MS_PrebuiltModulePath
1715                                ? 0
1716                                : ASTReader::ARR_ConfigurationMismatch;
1717  switch (getASTReader()->ReadAST(ModuleFilename,
1718                                  Source == MS_PrebuiltModulePath
1719                                      ? serialization::MK_PrebuiltModule
1720                                      : Source == MS_ModuleBuildPragma
1721                                            ? serialization::MK_ExplicitModule
1722                                            : serialization::MK_ImplicitModule,
1723                                  ImportLoc, ARRFlags)) {
1724  case ASTReader::Success: {
1725    if (M)
1726      return M;
1727    assert(Source != MS_ModuleCache &&
1728           "missing module, but file loaded from cache");
1729
1730    // A prebuilt module is indexed as a ModuleFile; the Module does not exist
1731    // until the first call to ReadAST.  Look it up now.
1732    M = HS.lookupModule(ModuleName, true, !IsInclusionDirective);
1733
1734    // Check whether M refers to the file in the prebuilt module path.
1735    if (M && M->getASTFile())
1736      if (auto ModuleFile = FileMgr->getFile(ModuleFilename))
1737        if (*ModuleFile == M->getASTFile())
1738          return M;
1739
1740    ModuleBuildFailed = true;
1741    getDiagnostics().Report(ModuleNameLoc, diag::err_module_prebuilt)
1742        << ModuleName;
1743    return ModuleLoadResult();
1744  }
1745
1746  case ASTReader::OutOfDate:
1747  case ASTReader::Missing:
1748    // The most interesting case.
1749    break;
1750
1751  case ASTReader::ConfigurationMismatch:
1752    if (Source == MS_PrebuiltModulePath)
1753      // FIXME: We shouldn't be setting HadFatalFailure below if we only
1754      // produce a warning here!
1755      getDiagnostics().Report(SourceLocation(),
1756                              diag::warn_module_config_mismatch)
1757          << ModuleFilename;
1758    // Fall through to error out.
1759    LLVM_FALLTHROUGH;
1760  case ASTReader::VersionMismatch:
1761  case ASTReader::HadErrors:
1762    // FIXME: Should this set ModuleBuildFailed = true?
1763    ModuleLoader::HadFatalFailure = true;
1764    // FIXME: The ASTReader will already have complained, but can we shoehorn
1765    // that diagnostic information into a more useful form?
1766    return ModuleLoadResult();
1767
1768  case ASTReader::Failure:
1769    // FIXME: Should this set ModuleBuildFailed = true?
1770    ModuleLoader::HadFatalFailure = true;
1771    return ModuleLoadResult();
1772  }
1773
1774  // ReadAST returned Missing or OutOfDate.
1775  if (Source != MS_ModuleCache) {
1776    // We don't know the desired configuration for this module and don't
1777    // necessarily even have a module map. Since ReadAST already produces
1778    // diagnostics for these two cases, we simply error out here.
1779    ModuleBuildFailed = true;
1780    return ModuleLoadResult();
1781  }
1782
1783  // The module file is missing or out-of-date. Build it.
1784  assert(M && "missing module, but trying to compile for cache");
1785
1786  // Check whether there is a cycle in the module graph.
1787  ModuleBuildStack ModPath = getSourceManager().getModuleBuildStack();
1788  ModuleBuildStack::iterator Pos = ModPath.begin(), PosEnd = ModPath.end();
1789  for (; Pos != PosEnd; ++Pos) {
1790    if (Pos->first == ModuleName)
1791      break;
1792  }
1793
1794  if (Pos != PosEnd) {
1795    SmallString<256> CyclePath;
1796    for (; Pos != PosEnd; ++Pos) {
1797      CyclePath += Pos->first;
1798      CyclePath += " -> ";
1799    }
1800    CyclePath += ModuleName;
1801
1802    getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
1803        << ModuleName << CyclePath;
1804    // FIXME: Should this set ModuleBuildFailed = true?
1805    // FIXME: Why is this not cached?
1806    return ModuleLoadResult::OtherUncachedFailure;
1807  }
1808
1809  // Check whether we have already attempted to build this module (but
1810  // failed).
1811  if (getPreprocessorOpts().FailedModules &&
1812      getPreprocessorOpts().FailedModules->hasAlreadyFailed(ModuleName)) {
1813    getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_built)
1814        << ModuleName << SourceRange(ImportLoc, ModuleNameLoc);
1815    ModuleBuildFailed = true;
1816    // FIXME: Why is this not cached?
1817    return ModuleLoadResult::OtherUncachedFailure;
1818  }
1819
1820  // Try to compile and then read the AST.
1821  if (!compileModuleAndReadAST(*this, ImportLoc, ModuleNameLoc, M,
1822                               ModuleFilename)) {
1823    assert(getDiagnostics().hasErrorOccurred() &&
1824           "undiagnosed error in compileModuleAndReadAST");
1825    if (getPreprocessorOpts().FailedModules)
1826      getPreprocessorOpts().FailedModules->addFailed(ModuleName);
1827    ModuleBuildFailed = true;
1828    // FIXME: Why is this not cached?
1829    return ModuleLoadResult::OtherUncachedFailure;
1830  }
1831
1832  // Okay, we've rebuilt and now loaded the module.
1833  return M;
1834}
1835
1836ModuleLoadResult
1837CompilerInstance::loadModule(SourceLocation ImportLoc,
1838                             ModuleIdPath Path,
1839                             Module::NameVisibilityKind Visibility,
1840                             bool IsInclusionDirective) {
1841  // Determine what file we're searching from.
1842  StringRef ModuleName = Path[0].first->getName();
1843  SourceLocation ModuleNameLoc = Path[0].second;
1844
1845  // If we've already handled this import, just return the cached result.
1846  // This one-element cache is important to eliminate redundant diagnostics
1847  // when both the preprocessor and parser see the same import declaration.
1848  if (ImportLoc.isValid() && LastModuleImportLoc == ImportLoc) {
1849    // Make the named module visible.
1850    if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
1851      TheASTReader->makeModuleVisible(LastModuleImportResult, Visibility,
1852                                      ImportLoc);
1853    return LastModuleImportResult;
1854  }
1855
1856  // If we don't already have information on this module, load the module now.
1857  Module *Module = nullptr;
1858  ModuleMap &MM = getPreprocessor().getHeaderSearchInfo().getModuleMap();
1859  if (auto MaybeModule = MM.getCachedModuleLoad(*Path[0].first)) {
1860    // Use the cached result, which may be nullptr.
1861    Module = *MaybeModule;
1862  } else if (ModuleName == getLangOpts().CurrentModule) {
1863    // This is the module we're building.
1864    Module = PP->getHeaderSearchInfo().lookupModule(
1865        ModuleName, /*AllowSearch*/ true,
1866        /*AllowExtraModuleMapSearch*/ !IsInclusionDirective);
1867    /// FIXME: perhaps we should (a) look for a module using the module name
1868    //  to file map (PrebuiltModuleFiles) and (b) diagnose if still not found?
1869    //if (Module == nullptr) {
1870    //  getDiagnostics().Report(ModuleNameLoc, diag::err_module_not_found)
1871    //    << ModuleName;
1872    //  ModuleBuildFailed = true;
1873    //  return ModuleLoadResult();
1874    //}
1875    MM.cacheModuleLoad(*Path[0].first, Module);
1876  } else {
1877    ModuleLoadResult Result = findOrCompileModuleAndReadAST(
1878        ModuleName, ImportLoc, ModuleNameLoc, IsInclusionDirective);
1879    // FIXME: Can we pull 'ModuleBuildFailed = true' out of the return
1880    // sequences for findOrCompileModuleAndReadAST and do it here (as long as
1881    // the result is not a config mismatch)?  See FIXMEs there.
1882    if (!Result.isNormal())
1883      return Result;
1884    Module = Result;
1885    MM.cacheModuleLoad(*Path[0].first, Module);
1886    if (!Module)
1887      return Module;
1888  }
1889
1890  // If we never found the module, fail.  Otherwise, verify the module and link
1891  // it up.
1892  if (!Module)
1893    return ModuleLoadResult();
1894
1895  // Verify that the rest of the module path actually corresponds to
1896  // a submodule.
1897  bool MapPrivateSubModToTopLevel = false;
1898  if (Path.size() > 1) {
1899    for (unsigned I = 1, N = Path.size(); I != N; ++I) {
1900      StringRef Name = Path[I].first->getName();
1901      clang::Module *Sub = Module->findSubmodule(Name);
1902
1903      // If the user is requesting Foo.Private and it doesn't exist, try to
1904      // match Foo_Private and emit a warning asking for the user to write
1905      // @import Foo_Private instead. FIXME: remove this when existing clients
1906      // migrate off of Foo.Private syntax.
1907      if (!Sub && PP->getLangOpts().ImplicitModules && Name == "Private" &&
1908          Module == Module->getTopLevelModule()) {
1909        SmallString<128> PrivateModule(Module->Name);
1910        PrivateModule.append("_Private");
1911
1912        SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> PrivPath;
1913        auto &II = PP->getIdentifierTable().get(
1914            PrivateModule, PP->getIdentifierInfo(Module->Name)->getTokenID());
1915        PrivPath.push_back(std::make_pair(&II, Path[0].second));
1916
1917        if (PP->getHeaderSearchInfo().lookupModule(PrivateModule, true,
1918                                                   !IsInclusionDirective))
1919          Sub =
1920              loadModule(ImportLoc, PrivPath, Visibility, IsInclusionDirective);
1921        if (Sub) {
1922          MapPrivateSubModToTopLevel = true;
1923          if (!getDiagnostics().isIgnored(
1924                  diag::warn_no_priv_submodule_use_toplevel, ImportLoc)) {
1925            getDiagnostics().Report(Path[I].second,
1926                                    diag::warn_no_priv_submodule_use_toplevel)
1927                << Path[I].first << Module->getFullModuleName() << PrivateModule
1928                << SourceRange(Path[0].second, Path[I].second)
1929                << FixItHint::CreateReplacement(SourceRange(Path[0].second),
1930                                                PrivateModule);
1931            getDiagnostics().Report(Sub->DefinitionLoc,
1932                                    diag::note_private_top_level_defined);
1933          }
1934        }
1935      }
1936
1937      if (!Sub) {
1938        // Attempt to perform typo correction to find a module name that works.
1939        SmallVector<StringRef, 2> Best;
1940        unsigned BestEditDistance = (std::numeric_limits<unsigned>::max)();
1941
1942        for (clang::Module::submodule_iterator J = Module->submodule_begin(),
1943                                            JEnd = Module->submodule_end();
1944             J != JEnd; ++J) {
1945          unsigned ED = Name.edit_distance((*J)->Name,
1946                                           /*AllowReplacements=*/true,
1947                                           BestEditDistance);
1948          if (ED <= BestEditDistance) {
1949            if (ED < BestEditDistance) {
1950              Best.clear();
1951              BestEditDistance = ED;
1952            }
1953
1954            Best.push_back((*J)->Name);
1955          }
1956        }
1957
1958        // If there was a clear winner, user it.
1959        if (Best.size() == 1) {
1960          getDiagnostics().Report(Path[I].second,
1961                                  diag::err_no_submodule_suggest)
1962            << Path[I].first << Module->getFullModuleName() << Best[0]
1963            << SourceRange(Path[0].second, Path[I-1].second)
1964            << FixItHint::CreateReplacement(SourceRange(Path[I].second),
1965                                            Best[0]);
1966
1967          Sub = Module->findSubmodule(Best[0]);
1968        }
1969      }
1970
1971      if (!Sub) {
1972        // No submodule by this name. Complain, and don't look for further
1973        // submodules.
1974        getDiagnostics().Report(Path[I].second, diag::err_no_submodule)
1975          << Path[I].first << Module->getFullModuleName()
1976          << SourceRange(Path[0].second, Path[I-1].second);
1977        break;
1978      }
1979
1980      Module = Sub;
1981    }
1982  }
1983
1984  // Make the named module visible, if it's not already part of the module
1985  // we are parsing.
1986  if (ModuleName != getLangOpts().CurrentModule) {
1987    if (!Module->IsFromModuleFile && !MapPrivateSubModToTopLevel) {
1988      // We have an umbrella header or directory that doesn't actually include
1989      // all of the headers within the directory it covers. Complain about
1990      // this missing submodule and recover by forgetting that we ever saw
1991      // this submodule.
1992      // FIXME: Should we detect this at module load time? It seems fairly
1993      // expensive (and rare).
1994      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
1995        << Module->getFullModuleName()
1996        << SourceRange(Path.front().second, Path.back().second);
1997
1998      return ModuleLoadResult::MissingExpected;
1999    }
2000
2001    // Check whether this module is available.
2002    if (Preprocessor::checkModuleIsAvailable(getLangOpts(), getTarget(),
2003                                             getDiagnostics(), Module)) {
2004      getDiagnostics().Report(ImportLoc, diag::note_module_import_here)
2005        << SourceRange(Path.front().second, Path.back().second);
2006      LastModuleImportLoc = ImportLoc;
2007      LastModuleImportResult = ModuleLoadResult();
2008      return ModuleLoadResult();
2009    }
2010
2011    TheASTReader->makeModuleVisible(Module, Visibility, ImportLoc);
2012  }
2013
2014  // Check for any configuration macros that have changed.
2015  clang::Module *TopModule = Module->getTopLevelModule();
2016  for (unsigned I = 0, N = TopModule->ConfigMacros.size(); I != N; ++I) {
2017    checkConfigMacro(getPreprocessor(), TopModule->ConfigMacros[I],
2018                     Module, ImportLoc);
2019  }
2020
2021  // Resolve any remaining module using export_as for this one.
2022  getPreprocessor()
2023      .getHeaderSearchInfo()
2024      .getModuleMap()
2025      .resolveLinkAsDependencies(TopModule);
2026
2027  LastModuleImportLoc = ImportLoc;
2028  LastModuleImportResult = ModuleLoadResult(Module);
2029  return LastModuleImportResult;
2030}
2031
2032void CompilerInstance::createModuleFromSource(SourceLocation ImportLoc,
2033                                              StringRef ModuleName,
2034                                              StringRef Source) {
2035  // Avoid creating filenames with special characters.
2036  SmallString<128> CleanModuleName(ModuleName);
2037  for (auto &C : CleanModuleName)
2038    if (!isAlphanumeric(C))
2039      C = '_';
2040
2041  // FIXME: Using a randomized filename here means that our intermediate .pcm
2042  // output is nondeterministic (as .pcm files refer to each other by name).
2043  // Can this affect the output in any way?
2044  SmallString<128> ModuleFileName;
2045  if (std::error_code EC = llvm::sys::fs::createTemporaryFile(
2046          CleanModuleName, "pcm", ModuleFileName)) {
2047    getDiagnostics().Report(ImportLoc, diag::err_fe_unable_to_open_output)
2048        << ModuleFileName << EC.message();
2049    return;
2050  }
2051  std::string ModuleMapFileName = (CleanModuleName + ".map").str();
2052
2053  FrontendInputFile Input(
2054      ModuleMapFileName,
2055      InputKind(getLanguageFromOptions(*Invocation->getLangOpts()),
2056                InputKind::ModuleMap, /*Preprocessed*/true));
2057
2058  std::string NullTerminatedSource(Source.str());
2059
2060  auto PreBuildStep = [&](CompilerInstance &Other) {
2061    // Create a virtual file containing our desired source.
2062    // FIXME: We shouldn't need to do this.
2063    const FileEntry *ModuleMapFile = Other.getFileManager().getVirtualFile(
2064        ModuleMapFileName, NullTerminatedSource.size(), 0);
2065    Other.getSourceManager().overrideFileContents(
2066        ModuleMapFile,
2067        llvm::MemoryBuffer::getMemBuffer(NullTerminatedSource.c_str()));
2068
2069    Other.BuiltModules = std::move(BuiltModules);
2070    Other.DeleteBuiltModules = false;
2071  };
2072
2073  auto PostBuildStep = [this](CompilerInstance &Other) {
2074    BuiltModules = std::move(Other.BuiltModules);
2075  };
2076
2077  // Build the module, inheriting any modules that we've built locally.
2078  if (compileModuleImpl(*this, ImportLoc, ModuleName, Input, StringRef(),
2079                        ModuleFileName, PreBuildStep, PostBuildStep)) {
2080    BuiltModules[ModuleName] = ModuleFileName.str();
2081    llvm::sys::RemoveFileOnSignal(ModuleFileName);
2082  }
2083}
2084
2085void CompilerInstance::makeModuleVisible(Module *Mod,
2086                                         Module::NameVisibilityKind Visibility,
2087                                         SourceLocation ImportLoc) {
2088  if (!TheASTReader)
2089    createASTReader();
2090  if (!TheASTReader)
2091    return;
2092
2093  TheASTReader->makeModuleVisible(Mod, Visibility, ImportLoc);
2094}
2095
2096GlobalModuleIndex *CompilerInstance::loadGlobalModuleIndex(
2097    SourceLocation TriggerLoc) {
2098  if (getPreprocessor().getHeaderSearchInfo().getModuleCachePath().empty())
2099    return nullptr;
2100  if (!TheASTReader)
2101    createASTReader();
2102  // Can't do anything if we don't have the module manager.
2103  if (!TheASTReader)
2104    return nullptr;
2105  // Get an existing global index.  This loads it if not already
2106  // loaded.
2107  TheASTReader->loadGlobalIndex();
2108  GlobalModuleIndex *GlobalIndex = TheASTReader->getGlobalIndex();
2109  // If the global index doesn't exist, create it.
2110  if (!GlobalIndex && shouldBuildGlobalModuleIndex() && hasFileManager() &&
2111      hasPreprocessor()) {
2112    llvm::sys::fs::create_directories(
2113      getPreprocessor().getHeaderSearchInfo().getModuleCachePath());
2114    if (llvm::Error Err = GlobalModuleIndex::writeIndex(
2115            getFileManager(), getPCHContainerReader(),
2116            getPreprocessor().getHeaderSearchInfo().getModuleCachePath())) {
2117      // FIXME this drops the error on the floor. This code is only used for
2118      // typo correction and drops more than just this one source of errors
2119      // (such as the directory creation failure above). It should handle the
2120      // error.
2121      consumeError(std::move(Err));
2122      return nullptr;
2123    }
2124    TheASTReader->resetForReload();
2125    TheASTReader->loadGlobalIndex();
2126    GlobalIndex = TheASTReader->getGlobalIndex();
2127  }
2128  // For finding modules needing to be imported for fixit messages,
2129  // we need to make the global index cover all modules, so we do that here.
2130  if (!HaveFullGlobalModuleIndex && GlobalIndex && !buildingModule()) {
2131    ModuleMap &MMap = getPreprocessor().getHeaderSearchInfo().getModuleMap();
2132    bool RecreateIndex = false;
2133    for (ModuleMap::module_iterator I = MMap.module_begin(),
2134        E = MMap.module_end(); I != E; ++I) {
2135      Module *TheModule = I->second;
2136      const FileEntry *Entry = TheModule->getASTFile();
2137      if (!Entry) {
2138        SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
2139        Path.push_back(std::make_pair(
2140            getPreprocessor().getIdentifierInfo(TheModule->Name), TriggerLoc));
2141        std::reverse(Path.begin(), Path.end());
2142        // Load a module as hidden.  This also adds it to the global index.
2143        loadModule(TheModule->DefinitionLoc, Path, Module::Hidden, false);
2144        RecreateIndex = true;
2145      }
2146    }
2147    if (RecreateIndex) {
2148      if (llvm::Error Err = GlobalModuleIndex::writeIndex(
2149              getFileManager(), getPCHContainerReader(),
2150              getPreprocessor().getHeaderSearchInfo().getModuleCachePath())) {
2151        // FIXME As above, this drops the error on the floor.
2152        consumeError(std::move(Err));
2153        return nullptr;
2154      }
2155      TheASTReader->resetForReload();
2156      TheASTReader->loadGlobalIndex();
2157      GlobalIndex = TheASTReader->getGlobalIndex();
2158    }
2159    HaveFullGlobalModuleIndex = true;
2160  }
2161  return GlobalIndex;
2162}
2163
2164// Check global module index for missing imports.
2165bool
2166CompilerInstance::lookupMissingImports(StringRef Name,
2167                                       SourceLocation TriggerLoc) {
2168  // Look for the symbol in non-imported modules, but only if an error
2169  // actually occurred.
2170  if (!buildingModule()) {
2171    // Load global module index, or retrieve a previously loaded one.
2172    GlobalModuleIndex *GlobalIndex = loadGlobalModuleIndex(
2173      TriggerLoc);
2174
2175    // Only if we have a global index.
2176    if (GlobalIndex) {
2177      GlobalModuleIndex::HitSet FoundModules;
2178
2179      // Find the modules that reference the identifier.
2180      // Note that this only finds top-level modules.
2181      // We'll let diagnoseTypo find the actual declaration module.
2182      if (GlobalIndex->lookupIdentifier(Name, FoundModules))
2183        return true;
2184    }
2185  }
2186
2187  return false;
2188}
2189void CompilerInstance::resetAndLeakSema() { llvm::BuryPointer(takeSema()); }
2190
2191void CompilerInstance::setExternalSemaSource(
2192    IntrusiveRefCntPtr<ExternalSemaSource> ESS) {
2193  ExternalSemaSrc = std::move(ESS);
2194}
2195