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