1//===--- FrontendAction.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/FrontendAction.h"
10#include "clang/AST/ASTConsumer.h"
11#include "clang/AST/ASTContext.h"
12#include "clang/AST/DeclGroup.h"
13#include "clang/Basic/Builtins.h"
14#include "clang/Basic/LangStandard.h"
15#include "clang/Frontend/ASTUnit.h"
16#include "clang/Frontend/CompilerInstance.h"
17#include "clang/Frontend/FrontendDiagnostic.h"
18#include "clang/Frontend/FrontendPluginRegistry.h"
19#include "clang/Frontend/LayoutOverrideSource.h"
20#include "clang/Frontend/MultiplexConsumer.h"
21#include "clang/Frontend/Utils.h"
22#include "clang/Lex/HeaderSearch.h"
23#include "clang/Lex/LiteralSupport.h"
24#include "clang/Lex/Preprocessor.h"
25#include "clang/Lex/PreprocessorOptions.h"
26#include "clang/Parse/ParseAST.h"
27#include "clang/Serialization/ASTDeserializationListener.h"
28#include "clang/Serialization/ASTReader.h"
29#include "clang/Serialization/GlobalModuleIndex.h"
30#include "llvm/Support/BuryPointer.h"
31#include "llvm/Support/ErrorHandling.h"
32#include "llvm/Support/FileSystem.h"
33#include "llvm/Support/Path.h"
34#include "llvm/Support/Timer.h"
35#include "llvm/Support/raw_ostream.h"
36#include <system_error>
37using namespace clang;
38
39LLVM_INSTANTIATE_REGISTRY(FrontendPluginRegistry)
40
41namespace {
42
43class DelegatingDeserializationListener : public ASTDeserializationListener {
44  ASTDeserializationListener *Previous;
45  bool DeletePrevious;
46
47public:
48  explicit DelegatingDeserializationListener(
49      ASTDeserializationListener *Previous, bool DeletePrevious)
50      : Previous(Previous), DeletePrevious(DeletePrevious) {}
51  ~DelegatingDeserializationListener() override {
52    if (DeletePrevious)
53      delete Previous;
54  }
55
56  void ReaderInitialized(ASTReader *Reader) override {
57    if (Previous)
58      Previous->ReaderInitialized(Reader);
59  }
60  void IdentifierRead(serialization::IdentID ID,
61                      IdentifierInfo *II) override {
62    if (Previous)
63      Previous->IdentifierRead(ID, II);
64  }
65  void TypeRead(serialization::TypeIdx Idx, QualType T) override {
66    if (Previous)
67      Previous->TypeRead(Idx, T);
68  }
69  void DeclRead(serialization::DeclID ID, const Decl *D) override {
70    if (Previous)
71      Previous->DeclRead(ID, D);
72  }
73  void SelectorRead(serialization::SelectorID ID, Selector Sel) override {
74    if (Previous)
75      Previous->SelectorRead(ID, Sel);
76  }
77  void MacroDefinitionRead(serialization::PreprocessedEntityID PPID,
78                           MacroDefinitionRecord *MD) override {
79    if (Previous)
80      Previous->MacroDefinitionRead(PPID, MD);
81  }
82};
83
84/// Dumps deserialized declarations.
85class DeserializedDeclsDumper : public DelegatingDeserializationListener {
86public:
87  explicit DeserializedDeclsDumper(ASTDeserializationListener *Previous,
88                                   bool DeletePrevious)
89      : DelegatingDeserializationListener(Previous, DeletePrevious) {}
90
91  void DeclRead(serialization::DeclID ID, const Decl *D) override {
92    llvm::outs() << "PCH DECL: " << D->getDeclKindName();
93    if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
94      llvm::outs() << " - ";
95      ND->printQualifiedName(llvm::outs());
96    }
97    llvm::outs() << "\n";
98
99    DelegatingDeserializationListener::DeclRead(ID, D);
100  }
101};
102
103/// Checks deserialized declarations and emits error if a name
104/// matches one given in command-line using -error-on-deserialized-decl.
105class DeserializedDeclsChecker : public DelegatingDeserializationListener {
106  ASTContext &Ctx;
107  std::set<std::string> NamesToCheck;
108
109public:
110  DeserializedDeclsChecker(ASTContext &Ctx,
111                           const std::set<std::string> &NamesToCheck,
112                           ASTDeserializationListener *Previous,
113                           bool DeletePrevious)
114      : DelegatingDeserializationListener(Previous, DeletePrevious), Ctx(Ctx),
115        NamesToCheck(NamesToCheck) {}
116
117  void DeclRead(serialization::DeclID ID, const Decl *D) override {
118    if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
119      if (NamesToCheck.find(ND->getNameAsString()) != NamesToCheck.end()) {
120        unsigned DiagID
121          = Ctx.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error,
122                                                 "%0 was deserialized");
123        Ctx.getDiagnostics().Report(Ctx.getFullLoc(D->getLocation()), DiagID)
124            << ND->getNameAsString();
125      }
126
127    DelegatingDeserializationListener::DeclRead(ID, D);
128  }
129};
130
131} // end anonymous namespace
132
133FrontendAction::FrontendAction() : Instance(nullptr) {}
134
135FrontendAction::~FrontendAction() {}
136
137void FrontendAction::setCurrentInput(const FrontendInputFile &CurrentInput,
138                                     std::unique_ptr<ASTUnit> AST) {
139  this->CurrentInput = CurrentInput;
140  CurrentASTUnit = std::move(AST);
141}
142
143Module *FrontendAction::getCurrentModule() const {
144  CompilerInstance &CI = getCompilerInstance();
145  return CI.getPreprocessor().getHeaderSearchInfo().lookupModule(
146      CI.getLangOpts().CurrentModule, /*AllowSearch*/false);
147}
148
149std::unique_ptr<ASTConsumer>
150FrontendAction::CreateWrappedASTConsumer(CompilerInstance &CI,
151                                         StringRef InFile) {
152  std::unique_ptr<ASTConsumer> Consumer = CreateASTConsumer(CI, InFile);
153  if (!Consumer)
154    return nullptr;
155
156  // Validate -add-plugin args.
157  bool FoundAllPlugins = true;
158  for (const std::string &Arg : CI.getFrontendOpts().AddPluginActions) {
159    bool Found = false;
160    for (const FrontendPluginRegistry::entry &Plugin :
161         FrontendPluginRegistry::entries()) {
162      if (Plugin.getName() == Arg)
163        Found = true;
164    }
165    if (!Found) {
166      CI.getDiagnostics().Report(diag::err_fe_invalid_plugin_name) << Arg;
167      FoundAllPlugins = false;
168    }
169  }
170  if (!FoundAllPlugins)
171    return nullptr;
172
173  // If there are no registered plugins we don't need to wrap the consumer
174  if (FrontendPluginRegistry::begin() == FrontendPluginRegistry::end())
175    return Consumer;
176
177  // If this is a code completion run, avoid invoking the plugin consumers
178  if (CI.hasCodeCompletionConsumer())
179    return Consumer;
180
181  // Collect the list of plugins that go before the main action (in Consumers)
182  // or after it (in AfterConsumers)
183  std::vector<std::unique_ptr<ASTConsumer>> Consumers;
184  std::vector<std::unique_ptr<ASTConsumer>> AfterConsumers;
185  for (const FrontendPluginRegistry::entry &Plugin :
186       FrontendPluginRegistry::entries()) {
187    std::unique_ptr<PluginASTAction> P = Plugin.instantiate();
188    PluginASTAction::ActionType ActionType = P->getActionType();
189    if (ActionType == PluginASTAction::Cmdline) {
190      // This is O(|plugins| * |add_plugins|), but since both numbers are
191      // way below 50 in practice, that's ok.
192      if (llvm::any_of(CI.getFrontendOpts().AddPluginActions,
193                       [&](const std::string &PluginAction) {
194                         return PluginAction == Plugin.getName();
195                       }))
196        ActionType = PluginASTAction::AddAfterMainAction;
197    }
198    if ((ActionType == PluginASTAction::AddBeforeMainAction ||
199         ActionType == PluginASTAction::AddAfterMainAction) &&
200        P->ParseArgs(
201            CI,
202            CI.getFrontendOpts().PluginArgs[std::string(Plugin.getName())])) {
203      std::unique_ptr<ASTConsumer> PluginConsumer = P->CreateASTConsumer(CI, InFile);
204      if (ActionType == PluginASTAction::AddBeforeMainAction) {
205        Consumers.push_back(std::move(PluginConsumer));
206      } else {
207        AfterConsumers.push_back(std::move(PluginConsumer));
208      }
209    }
210  }
211
212  // Add to Consumers the main consumer, then all the plugins that go after it
213  Consumers.push_back(std::move(Consumer));
214  for (auto &C : AfterConsumers) {
215    Consumers.push_back(std::move(C));
216  }
217
218  return std::make_unique<MultiplexConsumer>(std::move(Consumers));
219}
220
221/// For preprocessed files, if the first line is the linemarker and specifies
222/// the original source file name, use that name as the input file name.
223/// Returns the location of the first token after the line marker directive.
224///
225/// \param CI The compiler instance.
226/// \param InputFile Populated with the filename from the line marker.
227/// \param IsModuleMap If \c true, add a line note corresponding to this line
228///        directive. (We need to do this because the directive will not be
229///        visited by the preprocessor.)
230static SourceLocation ReadOriginalFileName(CompilerInstance &CI,
231                                           std::string &InputFile,
232                                           bool IsModuleMap = false) {
233  auto &SourceMgr = CI.getSourceManager();
234  auto MainFileID = SourceMgr.getMainFileID();
235
236  bool Invalid = false;
237  const auto *MainFileBuf = SourceMgr.getBuffer(MainFileID, &Invalid);
238  if (Invalid)
239    return SourceLocation();
240
241  std::unique_ptr<Lexer> RawLexer(
242      new Lexer(MainFileID, MainFileBuf, SourceMgr, CI.getLangOpts()));
243
244  // If the first line has the syntax of
245  //
246  // # NUM "FILENAME"
247  //
248  // we use FILENAME as the input file name.
249  Token T;
250  if (RawLexer->LexFromRawLexer(T) || T.getKind() != tok::hash)
251    return SourceLocation();
252  if (RawLexer->LexFromRawLexer(T) || T.isAtStartOfLine() ||
253      T.getKind() != tok::numeric_constant)
254    return SourceLocation();
255
256  unsigned LineNo;
257  SourceLocation LineNoLoc = T.getLocation();
258  if (IsModuleMap) {
259    llvm::SmallString<16> Buffer;
260    if (Lexer::getSpelling(LineNoLoc, Buffer, SourceMgr, CI.getLangOpts())
261            .getAsInteger(10, LineNo))
262      return SourceLocation();
263  }
264
265  RawLexer->LexFromRawLexer(T);
266  if (T.isAtStartOfLine() || T.getKind() != tok::string_literal)
267    return SourceLocation();
268
269  StringLiteralParser Literal(T, CI.getPreprocessor());
270  if (Literal.hadError)
271    return SourceLocation();
272  RawLexer->LexFromRawLexer(T);
273  if (T.isNot(tok::eof) && !T.isAtStartOfLine())
274    return SourceLocation();
275  InputFile = Literal.GetString().str();
276
277  if (IsModuleMap)
278    CI.getSourceManager().AddLineNote(
279        LineNoLoc, LineNo, SourceMgr.getLineTableFilenameID(InputFile), false,
280        false, SrcMgr::C_User_ModuleMap);
281
282  return T.getLocation();
283}
284
285static SmallVectorImpl<char> &
286operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
287  Includes.append(RHS.begin(), RHS.end());
288  return Includes;
289}
290
291static void addHeaderInclude(StringRef HeaderName,
292                             SmallVectorImpl<char> &Includes,
293                             const LangOptions &LangOpts,
294                             bool IsExternC) {
295  if (IsExternC && LangOpts.CPlusPlus)
296    Includes += "extern \"C\" {\n";
297  if (LangOpts.ObjC)
298    Includes += "#import \"";
299  else
300    Includes += "#include \"";
301
302  Includes += HeaderName;
303
304  Includes += "\"\n";
305  if (IsExternC && LangOpts.CPlusPlus)
306    Includes += "}\n";
307}
308
309/// Collect the set of header includes needed to construct the given
310/// module and update the TopHeaders file set of the module.
311///
312/// \param Module The module we're collecting includes from.
313///
314/// \param Includes Will be augmented with the set of \#includes or \#imports
315/// needed to load all of the named headers.
316static std::error_code collectModuleHeaderIncludes(
317    const LangOptions &LangOpts, FileManager &FileMgr, DiagnosticsEngine &Diag,
318    ModuleMap &ModMap, clang::Module *Module, SmallVectorImpl<char> &Includes) {
319  // Don't collect any headers for unavailable modules.
320  if (!Module->isAvailable())
321    return std::error_code();
322
323  // Resolve all lazy header directives to header files.
324  ModMap.resolveHeaderDirectives(Module);
325
326  // If any headers are missing, we can't build this module. In most cases,
327  // diagnostics for this should have already been produced; we only get here
328  // if explicit stat information was provided.
329  // FIXME: If the name resolves to a file with different stat information,
330  // produce a better diagnostic.
331  if (!Module->MissingHeaders.empty()) {
332    auto &MissingHeader = Module->MissingHeaders.front();
333    Diag.Report(MissingHeader.FileNameLoc, diag::err_module_header_missing)
334      << MissingHeader.IsUmbrella << MissingHeader.FileName;
335    return std::error_code();
336  }
337
338  // Add includes for each of these headers.
339  for (auto HK : {Module::HK_Normal, Module::HK_Private}) {
340    for (Module::Header &H : Module->Headers[HK]) {
341      Module->addTopHeader(H.Entry);
342      // Use the path as specified in the module map file. We'll look for this
343      // file relative to the module build directory (the directory containing
344      // the module map file) so this will find the same file that we found
345      // while parsing the module map.
346      addHeaderInclude(H.NameAsWritten, Includes, LangOpts, Module->IsExternC);
347    }
348  }
349  // Note that Module->PrivateHeaders will not be a TopHeader.
350
351  if (Module::Header UmbrellaHeader = Module->getUmbrellaHeader()) {
352    Module->addTopHeader(UmbrellaHeader.Entry);
353    if (Module->Parent)
354      // Include the umbrella header for submodules.
355      addHeaderInclude(UmbrellaHeader.NameAsWritten, Includes, LangOpts,
356                       Module->IsExternC);
357  } else if (Module::DirectoryName UmbrellaDir = Module->getUmbrellaDir()) {
358    // Add all of the headers we find in this subdirectory.
359    std::error_code EC;
360    SmallString<128> DirNative;
361    llvm::sys::path::native(UmbrellaDir.Entry->getName(), DirNative);
362
363    llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
364    SmallVector<std::pair<std::string, const FileEntry *>, 8> Headers;
365    for (llvm::vfs::recursive_directory_iterator Dir(FS, DirNative, EC), End;
366         Dir != End && !EC; Dir.increment(EC)) {
367      // Check whether this entry has an extension typically associated with
368      // headers.
369      if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
370               .Cases(".h", ".H", ".hh", ".hpp", true)
371               .Default(false))
372        continue;
373
374      auto Header = FileMgr.getFile(Dir->path());
375      // FIXME: This shouldn't happen unless there is a file system race. Is
376      // that worth diagnosing?
377      if (!Header)
378        continue;
379
380      // If this header is marked 'unavailable' in this module, don't include
381      // it.
382      if (ModMap.isHeaderUnavailableInModule(*Header, Module))
383        continue;
384
385      // Compute the relative path from the directory to this file.
386      SmallVector<StringRef, 16> Components;
387      auto PathIt = llvm::sys::path::rbegin(Dir->path());
388      for (int I = 0; I != Dir.level() + 1; ++I, ++PathIt)
389        Components.push_back(*PathIt);
390      SmallString<128> RelativeHeader(UmbrellaDir.NameAsWritten);
391      for (auto It = Components.rbegin(), End = Components.rend(); It != End;
392           ++It)
393        llvm::sys::path::append(RelativeHeader, *It);
394
395      std::string RelName = RelativeHeader.c_str();
396      Headers.push_back(std::make_pair(RelName, *Header));
397    }
398
399    if (EC)
400      return EC;
401
402    // Sort header paths and make the header inclusion order deterministic
403    // across different OSs and filesystems.
404    llvm::sort(Headers.begin(), Headers.end(), [](
405      const std::pair<std::string, const FileEntry *> &LHS,
406      const std::pair<std::string, const FileEntry *> &RHS) {
407        return LHS.first < RHS.first;
408    });
409    for (auto &H : Headers) {
410      // Include this header as part of the umbrella directory.
411      Module->addTopHeader(H.second);
412      addHeaderInclude(H.first, Includes, LangOpts, Module->IsExternC);
413    }
414  }
415
416  // Recurse into submodules.
417  for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
418                                      SubEnd = Module->submodule_end();
419       Sub != SubEnd; ++Sub)
420    if (std::error_code Err = collectModuleHeaderIncludes(
421            LangOpts, FileMgr, Diag, ModMap, *Sub, Includes))
422      return Err;
423
424  return std::error_code();
425}
426
427static bool loadModuleMapForModuleBuild(CompilerInstance &CI, bool IsSystem,
428                                        bool IsPreprocessed,
429                                        std::string &PresumedModuleMapFile,
430                                        unsigned &Offset) {
431  auto &SrcMgr = CI.getSourceManager();
432  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
433
434  // Map the current input to a file.
435  FileID ModuleMapID = SrcMgr.getMainFileID();
436  const FileEntry *ModuleMap = SrcMgr.getFileEntryForID(ModuleMapID);
437
438  // If the module map is preprocessed, handle the initial line marker;
439  // line directives are not part of the module map syntax in general.
440  Offset = 0;
441  if (IsPreprocessed) {
442    SourceLocation EndOfLineMarker =
443        ReadOriginalFileName(CI, PresumedModuleMapFile, /*IsModuleMap*/ true);
444    if (EndOfLineMarker.isValid())
445      Offset = CI.getSourceManager().getDecomposedLoc(EndOfLineMarker).second;
446  }
447
448  // Load the module map file.
449  if (HS.loadModuleMapFile(ModuleMap, IsSystem, ModuleMapID, &Offset,
450                           PresumedModuleMapFile))
451    return true;
452
453  if (SrcMgr.getBuffer(ModuleMapID)->getBufferSize() == Offset)
454    Offset = 0;
455
456  return false;
457}
458
459static Module *prepareToBuildModule(CompilerInstance &CI,
460                                    StringRef ModuleMapFilename) {
461  if (CI.getLangOpts().CurrentModule.empty()) {
462    CI.getDiagnostics().Report(diag::err_missing_module_name);
463
464    // FIXME: Eventually, we could consider asking whether there was just
465    // a single module described in the module map, and use that as a
466    // default. Then it would be fairly trivial to just "compile" a module
467    // map with a single module (the common case).
468    return nullptr;
469  }
470
471  // Dig out the module definition.
472  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
473  Module *M = HS.lookupModule(CI.getLangOpts().CurrentModule,
474                              /*AllowSearch=*/false);
475  if (!M) {
476    CI.getDiagnostics().Report(diag::err_missing_module)
477      << CI.getLangOpts().CurrentModule << ModuleMapFilename;
478
479    return nullptr;
480  }
481
482  // Check whether we can build this module at all.
483  if (Preprocessor::checkModuleIsAvailable(CI.getLangOpts(), CI.getTarget(),
484                                           CI.getDiagnostics(), M))
485    return nullptr;
486
487  // Inform the preprocessor that includes from within the input buffer should
488  // be resolved relative to the build directory of the module map file.
489  CI.getPreprocessor().setMainFileDir(M->Directory);
490
491  // If the module was inferred from a different module map (via an expanded
492  // umbrella module definition), track that fact.
493  // FIXME: It would be preferable to fill this in as part of processing
494  // the module map, rather than adding it after the fact.
495  StringRef OriginalModuleMapName = CI.getFrontendOpts().OriginalModuleMap;
496  if (!OriginalModuleMapName.empty()) {
497    auto OriginalModuleMap =
498        CI.getFileManager().getFile(OriginalModuleMapName,
499                                    /*openFile*/ true);
500    if (!OriginalModuleMap) {
501      CI.getDiagnostics().Report(diag::err_module_map_not_found)
502        << OriginalModuleMapName;
503      return nullptr;
504    }
505    if (*OriginalModuleMap != CI.getSourceManager().getFileEntryForID(
506                                 CI.getSourceManager().getMainFileID())) {
507      M->IsInferred = true;
508      CI.getPreprocessor().getHeaderSearchInfo().getModuleMap()
509        .setInferredModuleAllowedBy(M, *OriginalModuleMap);
510    }
511  }
512
513  // If we're being run from the command-line, the module build stack will not
514  // have been filled in yet, so complete it now in order to allow us to detect
515  // module cycles.
516  SourceManager &SourceMgr = CI.getSourceManager();
517  if (SourceMgr.getModuleBuildStack().empty())
518    SourceMgr.pushModuleBuildStack(CI.getLangOpts().CurrentModule,
519                                   FullSourceLoc(SourceLocation(), SourceMgr));
520  return M;
521}
522
523/// Compute the input buffer that should be used to build the specified module.
524static std::unique_ptr<llvm::MemoryBuffer>
525getInputBufferForModule(CompilerInstance &CI, Module *M) {
526  FileManager &FileMgr = CI.getFileManager();
527
528  // Collect the set of #includes we need to build the module.
529  SmallString<256> HeaderContents;
530  std::error_code Err = std::error_code();
531  if (Module::Header UmbrellaHeader = M->getUmbrellaHeader())
532    addHeaderInclude(UmbrellaHeader.NameAsWritten, HeaderContents,
533                     CI.getLangOpts(), M->IsExternC);
534  Err = collectModuleHeaderIncludes(
535      CI.getLangOpts(), FileMgr, CI.getDiagnostics(),
536      CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(), M,
537      HeaderContents);
538
539  if (Err) {
540    CI.getDiagnostics().Report(diag::err_module_cannot_create_includes)
541      << M->getFullModuleName() << Err.message();
542    return nullptr;
543  }
544
545  return llvm::MemoryBuffer::getMemBufferCopy(
546      HeaderContents, Module::getModuleInputBufferName());
547}
548
549bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
550                                     const FrontendInputFile &RealInput) {
551  FrontendInputFile Input(RealInput);
552  assert(!Instance && "Already processing a source file!");
553  assert(!Input.isEmpty() && "Unexpected empty filename!");
554  setCurrentInput(Input);
555  setCompilerInstance(&CI);
556
557  bool HasBegunSourceFile = false;
558  bool ReplayASTFile = Input.getKind().getFormat() == InputKind::Precompiled &&
559                       usesPreprocessorOnly();
560  if (!BeginInvocation(CI))
561    goto failure;
562
563  // If we're replaying the build of an AST file, import it and set up
564  // the initial state from its build.
565  if (ReplayASTFile) {
566    IntrusiveRefCntPtr<DiagnosticsEngine> Diags(&CI.getDiagnostics());
567
568    // The AST unit populates its own diagnostics engine rather than ours.
569    IntrusiveRefCntPtr<DiagnosticsEngine> ASTDiags(
570        new DiagnosticsEngine(Diags->getDiagnosticIDs(),
571                              &Diags->getDiagnosticOptions()));
572    ASTDiags->setClient(Diags->getClient(), /*OwnsClient*/false);
573
574    // FIXME: What if the input is a memory buffer?
575    StringRef InputFile = Input.getFile();
576
577    std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
578        std::string(InputFile), CI.getPCHContainerReader(),
579        ASTUnit::LoadPreprocessorOnly, ASTDiags, CI.getFileSystemOpts(),
580        CI.getCodeGenOpts().DebugTypeExtRefs);
581    if (!AST)
582      goto failure;
583
584    // Options relating to how we treat the input (but not what we do with it)
585    // are inherited from the AST unit.
586    CI.getHeaderSearchOpts() = AST->getHeaderSearchOpts();
587    CI.getPreprocessorOpts() = AST->getPreprocessorOpts();
588    CI.getLangOpts() = AST->getLangOpts();
589
590    // Set the shared objects, these are reset when we finish processing the
591    // file, otherwise the CompilerInstance will happily destroy them.
592    CI.setFileManager(&AST->getFileManager());
593    CI.createSourceManager(CI.getFileManager());
594    CI.getSourceManager().initializeForReplay(AST->getSourceManager());
595
596    // Preload all the module files loaded transitively by the AST unit. Also
597    // load all module map files that were parsed as part of building the AST
598    // unit.
599    if (auto ASTReader = AST->getASTReader()) {
600      auto &MM = ASTReader->getModuleManager();
601      auto &PrimaryModule = MM.getPrimaryModule();
602
603      for (serialization::ModuleFile &MF : MM)
604        if (&MF != &PrimaryModule)
605          CI.getFrontendOpts().ModuleFiles.push_back(MF.FileName);
606
607      ASTReader->visitTopLevelModuleMaps(
608          PrimaryModule, [&](const FileEntry *FE) {
609            CI.getFrontendOpts().ModuleMapFiles.push_back(
610                std::string(FE->getName()));
611          });
612    }
613
614    // Set up the input file for replay purposes.
615    auto Kind = AST->getInputKind();
616    if (Kind.getFormat() == InputKind::ModuleMap) {
617      Module *ASTModule =
618          AST->getPreprocessor().getHeaderSearchInfo().lookupModule(
619              AST->getLangOpts().CurrentModule, /*AllowSearch*/ false);
620      assert(ASTModule && "module file does not define its own module");
621      Input = FrontendInputFile(ASTModule->PresumedModuleMapFile, Kind);
622    } else {
623      auto &OldSM = AST->getSourceManager();
624      FileID ID = OldSM.getMainFileID();
625      if (auto *File = OldSM.getFileEntryForID(ID))
626        Input = FrontendInputFile(File->getName(), Kind);
627      else
628        Input = FrontendInputFile(OldSM.getBuffer(ID), Kind);
629    }
630    setCurrentInput(Input, std::move(AST));
631  }
632
633  // AST files follow a very different path, since they share objects via the
634  // AST unit.
635  if (Input.getKind().getFormat() == InputKind::Precompiled) {
636    assert(!usesPreprocessorOnly() && "this case was handled above");
637    assert(hasASTFileSupport() &&
638           "This action does not have AST file support!");
639
640    IntrusiveRefCntPtr<DiagnosticsEngine> Diags(&CI.getDiagnostics());
641
642    // FIXME: What if the input is a memory buffer?
643    StringRef InputFile = Input.getFile();
644
645    std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
646        std::string(InputFile), CI.getPCHContainerReader(),
647        ASTUnit::LoadEverything, Diags, CI.getFileSystemOpts(),
648        CI.getCodeGenOpts().DebugTypeExtRefs);
649
650    if (!AST)
651      goto failure;
652
653    // Inform the diagnostic client we are processing a source file.
654    CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), nullptr);
655    HasBegunSourceFile = true;
656
657    // Set the shared objects, these are reset when we finish processing the
658    // file, otherwise the CompilerInstance will happily destroy them.
659    CI.setFileManager(&AST->getFileManager());
660    CI.setSourceManager(&AST->getSourceManager());
661    CI.setPreprocessor(AST->getPreprocessorPtr());
662    Preprocessor &PP = CI.getPreprocessor();
663    PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
664                                           PP.getLangOpts());
665    CI.setASTContext(&AST->getASTContext());
666
667    setCurrentInput(Input, std::move(AST));
668
669    // Initialize the action.
670    if (!BeginSourceFileAction(CI))
671      goto failure;
672
673    // Create the AST consumer.
674    CI.setASTConsumer(CreateWrappedASTConsumer(CI, InputFile));
675    if (!CI.hasASTConsumer())
676      goto failure;
677
678    return true;
679  }
680
681  // Set up the file and source managers, if needed.
682  if (!CI.hasFileManager()) {
683    if (!CI.createFileManager()) {
684      goto failure;
685    }
686  }
687  if (!CI.hasSourceManager())
688    CI.createSourceManager(CI.getFileManager());
689
690  // Set up embedding for any specified files. Do this before we load any
691  // source files, including the primary module map for the compilation.
692  for (const auto &F : CI.getFrontendOpts().ModulesEmbedFiles) {
693    if (auto FE = CI.getFileManager().getFile(F, /*openFile*/true))
694      CI.getSourceManager().setFileIsTransient(*FE);
695    else
696      CI.getDiagnostics().Report(diag::err_modules_embed_file_not_found) << F;
697  }
698  if (CI.getFrontendOpts().ModulesEmbedAllFiles)
699    CI.getSourceManager().setAllFilesAreTransient(true);
700
701  // IR files bypass the rest of initialization.
702  if (Input.getKind().getLanguage() == Language::LLVM_IR) {
703    assert(hasIRSupport() &&
704           "This action does not have IR file support!");
705
706    // Inform the diagnostic client we are processing a source file.
707    CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), nullptr);
708    HasBegunSourceFile = true;
709
710    // Initialize the action.
711    if (!BeginSourceFileAction(CI))
712      goto failure;
713
714    // Initialize the main file entry.
715    if (!CI.InitializeSourceManager(CurrentInput))
716      goto failure;
717
718    return true;
719  }
720
721  // If the implicit PCH include is actually a directory, rather than
722  // a single file, search for a suitable PCH file in that directory.
723  if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
724    FileManager &FileMgr = CI.getFileManager();
725    PreprocessorOptions &PPOpts = CI.getPreprocessorOpts();
726    StringRef PCHInclude = PPOpts.ImplicitPCHInclude;
727    std::string SpecificModuleCachePath = CI.getSpecificModuleCachePath();
728    if (auto PCHDir = FileMgr.getDirectory(PCHInclude)) {
729      std::error_code EC;
730      SmallString<128> DirNative;
731      llvm::sys::path::native((*PCHDir)->getName(), DirNative);
732      bool Found = false;
733      llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
734      for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC),
735                                         DirEnd;
736           Dir != DirEnd && !EC; Dir.increment(EC)) {
737        // Check whether this is an acceptable AST file.
738        if (ASTReader::isAcceptableASTFile(
739                Dir->path(), FileMgr, CI.getPCHContainerReader(),
740                CI.getLangOpts(), CI.getTargetOpts(), CI.getPreprocessorOpts(),
741                SpecificModuleCachePath)) {
742          PPOpts.ImplicitPCHInclude = std::string(Dir->path());
743          Found = true;
744          break;
745        }
746      }
747
748      if (!Found) {
749        CI.getDiagnostics().Report(diag::err_fe_no_pch_in_dir) << PCHInclude;
750        goto failure;
751      }
752    }
753  }
754
755  // Set up the preprocessor if needed. When parsing model files the
756  // preprocessor of the original source is reused.
757  if (!isModelParsingAction())
758    CI.createPreprocessor(getTranslationUnitKind());
759
760  // Inform the diagnostic client we are processing a source file.
761  CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(),
762                                           &CI.getPreprocessor());
763  HasBegunSourceFile = true;
764
765  // Initialize the main file entry.
766  if (!CI.InitializeSourceManager(Input))
767    goto failure;
768
769  // For module map files, we first parse the module map and synthesize a
770  // "<module-includes>" buffer before more conventional processing.
771  if (Input.getKind().getFormat() == InputKind::ModuleMap) {
772    CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleMap);
773
774    std::string PresumedModuleMapFile;
775    unsigned OffsetToContents;
776    if (loadModuleMapForModuleBuild(CI, Input.isSystem(),
777                                    Input.isPreprocessed(),
778                                    PresumedModuleMapFile, OffsetToContents))
779      goto failure;
780
781    auto *CurrentModule = prepareToBuildModule(CI, Input.getFile());
782    if (!CurrentModule)
783      goto failure;
784
785    CurrentModule->PresumedModuleMapFile = PresumedModuleMapFile;
786
787    if (OffsetToContents)
788      // If the module contents are in the same file, skip to them.
789      CI.getPreprocessor().setSkipMainFilePreamble(OffsetToContents, true);
790    else {
791      // Otherwise, convert the module description to a suitable input buffer.
792      auto Buffer = getInputBufferForModule(CI, CurrentModule);
793      if (!Buffer)
794        goto failure;
795
796      // Reinitialize the main file entry to refer to the new input.
797      auto Kind = CurrentModule->IsSystem ? SrcMgr::C_System : SrcMgr::C_User;
798      auto &SourceMgr = CI.getSourceManager();
799      auto BufferID = SourceMgr.createFileID(std::move(Buffer), Kind);
800      assert(BufferID.isValid() && "couldn't create module buffer ID");
801      SourceMgr.setMainFileID(BufferID);
802    }
803  }
804
805  // Initialize the action.
806  if (!BeginSourceFileAction(CI))
807    goto failure;
808
809  // If we were asked to load any module map files, do so now.
810  for (const auto &Filename : CI.getFrontendOpts().ModuleMapFiles) {
811    if (auto File = CI.getFileManager().getFile(Filename))
812      CI.getPreprocessor().getHeaderSearchInfo().loadModuleMapFile(
813          *File, /*IsSystem*/false);
814    else
815      CI.getDiagnostics().Report(diag::err_module_map_not_found) << Filename;
816  }
817
818  // Add a module declaration scope so that modules from -fmodule-map-file
819  // arguments may shadow modules found implicitly in search paths.
820  CI.getPreprocessor()
821      .getHeaderSearchInfo()
822      .getModuleMap()
823      .finishModuleDeclarationScope();
824
825  // Create the AST context and consumer unless this is a preprocessor only
826  // action.
827  if (!usesPreprocessorOnly()) {
828    // Parsing a model file should reuse the existing ASTContext.
829    if (!isModelParsingAction())
830      CI.createASTContext();
831
832    // For preprocessed files, check if the first line specifies the original
833    // source file name with a linemarker.
834    std::string PresumedInputFile = std::string(getCurrentFileOrBufferName());
835    if (Input.isPreprocessed())
836      ReadOriginalFileName(CI, PresumedInputFile);
837
838    std::unique_ptr<ASTConsumer> Consumer =
839        CreateWrappedASTConsumer(CI, PresumedInputFile);
840    if (!Consumer)
841      goto failure;
842
843    // FIXME: should not overwrite ASTMutationListener when parsing model files?
844    if (!isModelParsingAction())
845      CI.getASTContext().setASTMutationListener(Consumer->GetASTMutationListener());
846
847    if (!CI.getPreprocessorOpts().ChainedIncludes.empty()) {
848      // Convert headers to PCH and chain them.
849      IntrusiveRefCntPtr<ExternalSemaSource> source, FinalReader;
850      source = createChainedIncludesSource(CI, FinalReader);
851      if (!source)
852        goto failure;
853      CI.setASTReader(static_cast<ASTReader *>(FinalReader.get()));
854      CI.getASTContext().setExternalSource(source);
855    } else if (CI.getLangOpts().Modules ||
856               !CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
857      // Use PCM or PCH.
858      assert(hasPCHSupport() && "This action does not have PCH support!");
859      ASTDeserializationListener *DeserialListener =
860          Consumer->GetASTDeserializationListener();
861      bool DeleteDeserialListener = false;
862      if (CI.getPreprocessorOpts().DumpDeserializedPCHDecls) {
863        DeserialListener = new DeserializedDeclsDumper(DeserialListener,
864                                                       DeleteDeserialListener);
865        DeleteDeserialListener = true;
866      }
867      if (!CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn.empty()) {
868        DeserialListener = new DeserializedDeclsChecker(
869            CI.getASTContext(),
870            CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn,
871            DeserialListener, DeleteDeserialListener);
872        DeleteDeserialListener = true;
873      }
874      if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
875        CI.createPCHExternalASTSource(
876            CI.getPreprocessorOpts().ImplicitPCHInclude,
877            CI.getPreprocessorOpts().DisablePCHValidation,
878          CI.getPreprocessorOpts().AllowPCHWithCompilerErrors, DeserialListener,
879            DeleteDeserialListener);
880        if (!CI.getASTContext().getExternalSource())
881          goto failure;
882      }
883      // If modules are enabled, create the AST reader before creating
884      // any builtins, so that all declarations know that they might be
885      // extended by an external source.
886      if (CI.getLangOpts().Modules || !CI.hasASTContext() ||
887          !CI.getASTContext().getExternalSource()) {
888        CI.createASTReader();
889        CI.getASTReader()->setDeserializationListener(DeserialListener,
890                                                      DeleteDeserialListener);
891      }
892    }
893
894    CI.setASTConsumer(std::move(Consumer));
895    if (!CI.hasASTConsumer())
896      goto failure;
897  }
898
899  // Initialize built-in info as long as we aren't using an external AST
900  // source.
901  if (CI.getLangOpts().Modules || !CI.hasASTContext() ||
902      !CI.getASTContext().getExternalSource()) {
903    Preprocessor &PP = CI.getPreprocessor();
904    PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
905                                           PP.getLangOpts());
906  } else {
907    // FIXME: If this is a problem, recover from it by creating a multiplex
908    // source.
909    assert((!CI.getLangOpts().Modules || CI.getASTReader()) &&
910           "modules enabled but created an external source that "
911           "doesn't support modules");
912  }
913
914  // If we were asked to load any module files, do so now.
915  for (const auto &ModuleFile : CI.getFrontendOpts().ModuleFiles)
916    if (!CI.loadModuleFile(ModuleFile))
917      goto failure;
918
919  // If there is a layout overrides file, attach an external AST source that
920  // provides the layouts from that file.
921  if (!CI.getFrontendOpts().OverrideRecordLayoutsFile.empty() &&
922      CI.hasASTContext() && !CI.getASTContext().getExternalSource()) {
923    IntrusiveRefCntPtr<ExternalASTSource>
924      Override(new LayoutOverrideSource(
925                     CI.getFrontendOpts().OverrideRecordLayoutsFile));
926    CI.getASTContext().setExternalSource(Override);
927  }
928
929  return true;
930
931  // If we failed, reset state since the client will not end up calling the
932  // matching EndSourceFile().
933failure:
934  if (HasBegunSourceFile)
935    CI.getDiagnosticClient().EndSourceFile();
936  CI.clearOutputFiles(/*EraseFiles=*/true);
937  CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
938  setCurrentInput(FrontendInputFile());
939  setCompilerInstance(nullptr);
940  return false;
941}
942
943llvm::Error FrontendAction::Execute() {
944  CompilerInstance &CI = getCompilerInstance();
945
946  if (CI.hasFrontendTimer()) {
947    llvm::TimeRegion Timer(CI.getFrontendTimer());
948    ExecuteAction();
949  }
950  else ExecuteAction();
951
952  // If we are supposed to rebuild the global module index, do so now unless
953  // there were any module-build failures.
954  if (CI.shouldBuildGlobalModuleIndex() && CI.hasFileManager() &&
955      CI.hasPreprocessor()) {
956    StringRef Cache =
957        CI.getPreprocessor().getHeaderSearchInfo().getModuleCachePath();
958    if (!Cache.empty()) {
959      if (llvm::Error Err = GlobalModuleIndex::writeIndex(
960              CI.getFileManager(), CI.getPCHContainerReader(), Cache)) {
961        // FIXME this drops the error on the floor, but
962        // Index/pch-from-libclang.c seems to rely on dropping at least some of
963        // the error conditions!
964        consumeError(std::move(Err));
965      }
966    }
967  }
968
969  return llvm::Error::success();
970}
971
972void FrontendAction::EndSourceFile() {
973  CompilerInstance &CI = getCompilerInstance();
974
975  // Inform the diagnostic client we are done with this source file.
976  CI.getDiagnosticClient().EndSourceFile();
977
978  // Inform the preprocessor we are done.
979  if (CI.hasPreprocessor())
980    CI.getPreprocessor().EndSourceFile();
981
982  // Finalize the action.
983  EndSourceFileAction();
984
985  // Sema references the ast consumer, so reset sema first.
986  //
987  // FIXME: There is more per-file stuff we could just drop here?
988  bool DisableFree = CI.getFrontendOpts().DisableFree;
989  if (DisableFree) {
990    CI.resetAndLeakSema();
991    CI.resetAndLeakASTContext();
992    llvm::BuryPointer(CI.takeASTConsumer().get());
993  } else {
994    CI.setSema(nullptr);
995    CI.setASTContext(nullptr);
996    CI.setASTConsumer(nullptr);
997  }
998
999  if (CI.getFrontendOpts().ShowStats) {
1000    llvm::errs() << "\nSTATISTICS FOR '" << getCurrentFile() << "':\n";
1001    CI.getPreprocessor().PrintStats();
1002    CI.getPreprocessor().getIdentifierTable().PrintStats();
1003    CI.getPreprocessor().getHeaderSearchInfo().PrintStats();
1004    CI.getSourceManager().PrintStats();
1005    llvm::errs() << "\n";
1006  }
1007
1008  // Cleanup the output streams, and erase the output files if instructed by the
1009  // FrontendAction.
1010  CI.clearOutputFiles(/*EraseFiles=*/shouldEraseOutputFiles());
1011
1012  if (isCurrentFileAST()) {
1013    if (DisableFree) {
1014      CI.resetAndLeakPreprocessor();
1015      CI.resetAndLeakSourceManager();
1016      CI.resetAndLeakFileManager();
1017      llvm::BuryPointer(std::move(CurrentASTUnit));
1018    } else {
1019      CI.setPreprocessor(nullptr);
1020      CI.setSourceManager(nullptr);
1021      CI.setFileManager(nullptr);
1022    }
1023  }
1024
1025  setCompilerInstance(nullptr);
1026  setCurrentInput(FrontendInputFile());
1027  CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
1028}
1029
1030bool FrontendAction::shouldEraseOutputFiles() {
1031  return getCompilerInstance().getDiagnostics().hasErrorOccurred();
1032}
1033
1034//===----------------------------------------------------------------------===//
1035// Utility Actions
1036//===----------------------------------------------------------------------===//
1037
1038void ASTFrontendAction::ExecuteAction() {
1039  CompilerInstance &CI = getCompilerInstance();
1040  if (!CI.hasPreprocessor())
1041    return;
1042
1043  // FIXME: Move the truncation aspect of this into Sema, we delayed this till
1044  // here so the source manager would be initialized.
1045  if (hasCodeCompletionSupport() &&
1046      !CI.getFrontendOpts().CodeCompletionAt.FileName.empty())
1047    CI.createCodeCompletionConsumer();
1048
1049  // Use a code completion consumer?
1050  CodeCompleteConsumer *CompletionConsumer = nullptr;
1051  if (CI.hasCodeCompletionConsumer())
1052    CompletionConsumer = &CI.getCodeCompletionConsumer();
1053
1054  if (!CI.hasSema())
1055    CI.createSema(getTranslationUnitKind(), CompletionConsumer);
1056
1057  ParseAST(CI.getSema(), CI.getFrontendOpts().ShowStats,
1058           CI.getFrontendOpts().SkipFunctionBodies);
1059}
1060
1061void PluginASTAction::anchor() { }
1062
1063std::unique_ptr<ASTConsumer>
1064PreprocessorFrontendAction::CreateASTConsumer(CompilerInstance &CI,
1065                                              StringRef InFile) {
1066  llvm_unreachable("Invalid CreateASTConsumer on preprocessor action!");
1067}
1068
1069bool WrapperFrontendAction::PrepareToExecuteAction(CompilerInstance &CI) {
1070  return WrappedAction->PrepareToExecuteAction(CI);
1071}
1072std::unique_ptr<ASTConsumer>
1073WrapperFrontendAction::CreateASTConsumer(CompilerInstance &CI,
1074                                         StringRef InFile) {
1075  return WrappedAction->CreateASTConsumer(CI, InFile);
1076}
1077bool WrapperFrontendAction::BeginInvocation(CompilerInstance &CI) {
1078  return WrappedAction->BeginInvocation(CI);
1079}
1080bool WrapperFrontendAction::BeginSourceFileAction(CompilerInstance &CI) {
1081  WrappedAction->setCurrentInput(getCurrentInput());
1082  WrappedAction->setCompilerInstance(&CI);
1083  auto Ret = WrappedAction->BeginSourceFileAction(CI);
1084  // BeginSourceFileAction may change CurrentInput, e.g. during module builds.
1085  setCurrentInput(WrappedAction->getCurrentInput());
1086  return Ret;
1087}
1088void WrapperFrontendAction::ExecuteAction() {
1089  WrappedAction->ExecuteAction();
1090}
1091void WrapperFrontendAction::EndSourceFileAction() {
1092  WrappedAction->EndSourceFileAction();
1093}
1094bool WrapperFrontendAction::shouldEraseOutputFiles() {
1095  return WrappedAction->shouldEraseOutputFiles();
1096}
1097
1098bool WrapperFrontendAction::usesPreprocessorOnly() const {
1099  return WrappedAction->usesPreprocessorOnly();
1100}
1101TranslationUnitKind WrapperFrontendAction::getTranslationUnitKind() {
1102  return WrappedAction->getTranslationUnitKind();
1103}
1104bool WrapperFrontendAction::hasPCHSupport() const {
1105  return WrappedAction->hasPCHSupport();
1106}
1107bool WrapperFrontendAction::hasASTFileSupport() const {
1108  return WrappedAction->hasASTFileSupport();
1109}
1110bool WrapperFrontendAction::hasIRSupport() const {
1111  return WrappedAction->hasIRSupport();
1112}
1113bool WrapperFrontendAction::hasCodeCompletionSupport() const {
1114  return WrappedAction->hasCodeCompletionSupport();
1115}
1116
1117WrapperFrontendAction::WrapperFrontendAction(
1118    std::unique_ptr<FrontendAction> WrappedAction)
1119  : WrappedAction(std::move(WrappedAction)) {}
1120
1121