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/DiagnosticOptions.h"
15 #include "clang/Basic/FileEntry.h"
16 #include "clang/Basic/LangStandard.h"
17 #include "clang/Basic/Sarif.h"
18 #include "clang/Frontend/ASTUnit.h"
19 #include "clang/Frontend/CompilerInstance.h"
20 #include "clang/Frontend/FrontendDiagnostic.h"
21 #include "clang/Frontend/FrontendPluginRegistry.h"
22 #include "clang/Frontend/LayoutOverrideSource.h"
23 #include "clang/Frontend/MultiplexConsumer.h"
24 #include "clang/Frontend/SARIFDiagnosticPrinter.h"
25 #include "clang/Frontend/Utils.h"
26 #include "clang/Lex/HeaderSearch.h"
27 #include "clang/Lex/LiteralSupport.h"
28 #include "clang/Lex/Preprocessor.h"
29 #include "clang/Lex/PreprocessorOptions.h"
30 #include "clang/Parse/ParseAST.h"
31 #include "clang/Sema/HLSLExternalSemaSource.h"
32 #include "clang/Sema/MultiplexExternalSemaSource.h"
33 #include "clang/Serialization/ASTDeserializationListener.h"
34 #include "clang/Serialization/ASTReader.h"
35 #include "clang/Serialization/GlobalModuleIndex.h"
36 #include "llvm/ADT/ScopeExit.h"
37 #include "llvm/Support/BuryPointer.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/FileSystem.h"
40 #include "llvm/Support/Path.h"
41 #include "llvm/Support/Timer.h"
42 #include "llvm/Support/raw_ostream.h"
43 #include <memory>
44 #include <system_error>
45 using namespace clang;
46 
47 LLVM_INSTANTIATE_REGISTRY(FrontendPluginRegistry)
48 
49 namespace {
50 
51 class DelegatingDeserializationListener : public ASTDeserializationListener {
52   ASTDeserializationListener *Previous;
53   bool DeletePrevious;
54 
55 public:
56   explicit DelegatingDeserializationListener(
57       ASTDeserializationListener *Previous, bool DeletePrevious)
58       : Previous(Previous), DeletePrevious(DeletePrevious) {}
59   ~DelegatingDeserializationListener() override {
60     if (DeletePrevious)
61       delete Previous;
62   }
63 
64   void ReaderInitialized(ASTReader *Reader) override {
65     if (Previous)
66       Previous->ReaderInitialized(Reader);
67   }
68   void IdentifierRead(serialization::IdentID ID,
69                       IdentifierInfo *II) override {
70     if (Previous)
71       Previous->IdentifierRead(ID, II);
72   }
73   void TypeRead(serialization::TypeIdx Idx, QualType T) override {
74     if (Previous)
75       Previous->TypeRead(Idx, T);
76   }
77   void DeclRead(serialization::DeclID ID, const Decl *D) override {
78     if (Previous)
79       Previous->DeclRead(ID, D);
80   }
81   void SelectorRead(serialization::SelectorID ID, Selector Sel) override {
82     if (Previous)
83       Previous->SelectorRead(ID, Sel);
84   }
85   void MacroDefinitionRead(serialization::PreprocessedEntityID PPID,
86                            MacroDefinitionRecord *MD) override {
87     if (Previous)
88       Previous->MacroDefinitionRead(PPID, MD);
89   }
90 };
91 
92 /// Dumps deserialized declarations.
93 class DeserializedDeclsDumper : public DelegatingDeserializationListener {
94 public:
95   explicit DeserializedDeclsDumper(ASTDeserializationListener *Previous,
96                                    bool DeletePrevious)
97       : DelegatingDeserializationListener(Previous, DeletePrevious) {}
98 
99   void DeclRead(serialization::DeclID ID, const Decl *D) override {
100     llvm::outs() << "PCH DECL: " << D->getDeclKindName();
101     if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
102       llvm::outs() << " - ";
103       ND->printQualifiedName(llvm::outs());
104     }
105     llvm::outs() << "\n";
106 
107     DelegatingDeserializationListener::DeclRead(ID, D);
108   }
109 };
110 
111 /// Checks deserialized declarations and emits error if a name
112 /// matches one given in command-line using -error-on-deserialized-decl.
113 class DeserializedDeclsChecker : public DelegatingDeserializationListener {
114   ASTContext &Ctx;
115   std::set<std::string> NamesToCheck;
116 
117 public:
118   DeserializedDeclsChecker(ASTContext &Ctx,
119                            const std::set<std::string> &NamesToCheck,
120                            ASTDeserializationListener *Previous,
121                            bool DeletePrevious)
122       : DelegatingDeserializationListener(Previous, DeletePrevious), Ctx(Ctx),
123         NamesToCheck(NamesToCheck) {}
124 
125   void DeclRead(serialization::DeclID ID, const Decl *D) override {
126     if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
127       if (NamesToCheck.find(ND->getNameAsString()) != NamesToCheck.end()) {
128         unsigned DiagID
129           = Ctx.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error,
130                                                  "%0 was deserialized");
131         Ctx.getDiagnostics().Report(Ctx.getFullLoc(D->getLocation()), DiagID)
132             << ND;
133       }
134 
135     DelegatingDeserializationListener::DeclRead(ID, D);
136   }
137 };
138 
139 } // end anonymous namespace
140 
141 FrontendAction::FrontendAction() : Instance(nullptr) {}
142 
143 FrontendAction::~FrontendAction() {}
144 
145 void FrontendAction::setCurrentInput(const FrontendInputFile &CurrentInput,
146                                      std::unique_ptr<ASTUnit> AST) {
147   this->CurrentInput = CurrentInput;
148   CurrentASTUnit = std::move(AST);
149 }
150 
151 Module *FrontendAction::getCurrentModule() const {
152   CompilerInstance &CI = getCompilerInstance();
153   return CI.getPreprocessor().getHeaderSearchInfo().lookupModule(
154       CI.getLangOpts().CurrentModule, SourceLocation(), /*AllowSearch*/false);
155 }
156 
157 std::unique_ptr<ASTConsumer>
158 FrontendAction::CreateWrappedASTConsumer(CompilerInstance &CI,
159                                          StringRef InFile) {
160   std::unique_ptr<ASTConsumer> Consumer = CreateASTConsumer(CI, InFile);
161   if (!Consumer)
162     return nullptr;
163 
164   // Validate -add-plugin args.
165   bool FoundAllPlugins = true;
166   for (const std::string &Arg : CI.getFrontendOpts().AddPluginActions) {
167     bool Found = false;
168     for (const FrontendPluginRegistry::entry &Plugin :
169          FrontendPluginRegistry::entries()) {
170       if (Plugin.getName() == Arg)
171         Found = true;
172     }
173     if (!Found) {
174       CI.getDiagnostics().Report(diag::err_fe_invalid_plugin_name) << Arg;
175       FoundAllPlugins = false;
176     }
177   }
178   if (!FoundAllPlugins)
179     return nullptr;
180 
181   // If there are no registered plugins we don't need to wrap the consumer
182   if (FrontendPluginRegistry::begin() == FrontendPluginRegistry::end())
183     return Consumer;
184 
185   // If this is a code completion run, avoid invoking the plugin consumers
186   if (CI.hasCodeCompletionConsumer())
187     return Consumer;
188 
189   // Collect the list of plugins that go before the main action (in Consumers)
190   // or after it (in AfterConsumers)
191   std::vector<std::unique_ptr<ASTConsumer>> Consumers;
192   std::vector<std::unique_ptr<ASTConsumer>> AfterConsumers;
193   for (const FrontendPluginRegistry::entry &Plugin :
194        FrontendPluginRegistry::entries()) {
195     std::unique_ptr<PluginASTAction> P = Plugin.instantiate();
196     PluginASTAction::ActionType ActionType = P->getActionType();
197     if (ActionType == PluginASTAction::CmdlineAfterMainAction ||
198         ActionType == PluginASTAction::CmdlineBeforeMainAction) {
199       // This is O(|plugins| * |add_plugins|), but since both numbers are
200       // way below 50 in practice, that's ok.
201       if (llvm::is_contained(CI.getFrontendOpts().AddPluginActions,
202                              Plugin.getName())) {
203         if (ActionType == PluginASTAction::CmdlineBeforeMainAction)
204           ActionType = PluginASTAction::AddBeforeMainAction;
205         else
206           ActionType = PluginASTAction::AddAfterMainAction;
207       }
208     }
209     if ((ActionType == PluginASTAction::AddBeforeMainAction ||
210          ActionType == PluginASTAction::AddAfterMainAction) &&
211         P->ParseArgs(
212             CI,
213             CI.getFrontendOpts().PluginArgs[std::string(Plugin.getName())])) {
214       std::unique_ptr<ASTConsumer> PluginConsumer = P->CreateASTConsumer(CI, InFile);
215       if (ActionType == PluginASTAction::AddBeforeMainAction) {
216         Consumers.push_back(std::move(PluginConsumer));
217       } else {
218         AfterConsumers.push_back(std::move(PluginConsumer));
219       }
220     }
221   }
222 
223   // Add to Consumers the main consumer, then all the plugins that go after it
224   Consumers.push_back(std::move(Consumer));
225   if (!AfterConsumers.empty()) {
226     // If we have plugins after the main consumer, which may be the codegen
227     // action, they likely will need the ASTContext, so don't clear it in the
228     // codegen action.
229     CI.getCodeGenOpts().ClearASTBeforeBackend = false;
230     for (auto &C : AfterConsumers)
231       Consumers.push_back(std::move(C));
232   }
233 
234   return std::make_unique<MultiplexConsumer>(std::move(Consumers));
235 }
236 
237 /// For preprocessed files, if the first line is the linemarker and specifies
238 /// the original source file name, use that name as the input file name.
239 /// Returns the location of the first token after the line marker directive.
240 ///
241 /// \param CI The compiler instance.
242 /// \param InputFile Populated with the filename from the line marker.
243 /// \param IsModuleMap If \c true, add a line note corresponding to this line
244 ///        directive. (We need to do this because the directive will not be
245 ///        visited by the preprocessor.)
246 static SourceLocation ReadOriginalFileName(CompilerInstance &CI,
247                                            std::string &InputFile,
248                                            bool IsModuleMap = false) {
249   auto &SourceMgr = CI.getSourceManager();
250   auto MainFileID = SourceMgr.getMainFileID();
251 
252   auto MainFileBuf = SourceMgr.getBufferOrNone(MainFileID);
253   if (!MainFileBuf)
254     return SourceLocation();
255 
256   std::unique_ptr<Lexer> RawLexer(
257       new Lexer(MainFileID, *MainFileBuf, SourceMgr, CI.getLangOpts()));
258 
259   // If the first line has the syntax of
260   //
261   // # NUM "FILENAME"
262   //
263   // we use FILENAME as the input file name.
264   Token T;
265   if (RawLexer->LexFromRawLexer(T) || T.getKind() != tok::hash)
266     return SourceLocation();
267   if (RawLexer->LexFromRawLexer(T) || T.isAtStartOfLine() ||
268       T.getKind() != tok::numeric_constant)
269     return SourceLocation();
270 
271   unsigned LineNo;
272   SourceLocation LineNoLoc = T.getLocation();
273   if (IsModuleMap) {
274     llvm::SmallString<16> Buffer;
275     if (Lexer::getSpelling(LineNoLoc, Buffer, SourceMgr, CI.getLangOpts())
276             .getAsInteger(10, LineNo))
277       return SourceLocation();
278   }
279 
280   RawLexer->LexFromRawLexer(T);
281   if (T.isAtStartOfLine() || T.getKind() != tok::string_literal)
282     return SourceLocation();
283 
284   StringLiteralParser Literal(T, CI.getPreprocessor());
285   if (Literal.hadError)
286     return SourceLocation();
287   RawLexer->LexFromRawLexer(T);
288   if (T.isNot(tok::eof) && !T.isAtStartOfLine())
289     return SourceLocation();
290   InputFile = Literal.GetString().str();
291 
292   if (IsModuleMap)
293     CI.getSourceManager().AddLineNote(
294         LineNoLoc, LineNo, SourceMgr.getLineTableFilenameID(InputFile), false,
295         false, SrcMgr::C_User_ModuleMap);
296 
297   return T.getLocation();
298 }
299 
300 static SmallVectorImpl<char> &
301 operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
302   Includes.append(RHS.begin(), RHS.end());
303   return Includes;
304 }
305 
306 static void addHeaderInclude(StringRef HeaderName,
307                              SmallVectorImpl<char> &Includes,
308                              const LangOptions &LangOpts,
309                              bool IsExternC) {
310   if (IsExternC && LangOpts.CPlusPlus)
311     Includes += "extern \"C\" {\n";
312   if (LangOpts.ObjC)
313     Includes += "#import \"";
314   else
315     Includes += "#include \"";
316 
317   Includes += HeaderName;
318 
319   Includes += "\"\n";
320   if (IsExternC && LangOpts.CPlusPlus)
321     Includes += "}\n";
322 }
323 
324 /// Collect the set of header includes needed to construct the given
325 /// module and update the TopHeaders file set of the module.
326 ///
327 /// \param Module The module we're collecting includes from.
328 ///
329 /// \param Includes Will be augmented with the set of \#includes or \#imports
330 /// needed to load all of the named headers.
331 static std::error_code collectModuleHeaderIncludes(
332     const LangOptions &LangOpts, FileManager &FileMgr, DiagnosticsEngine &Diag,
333     ModuleMap &ModMap, clang::Module *Module, SmallVectorImpl<char> &Includes) {
334   // Don't collect any headers for unavailable modules.
335   if (!Module->isAvailable())
336     return std::error_code();
337 
338   // Resolve all lazy header directives to header files.
339   ModMap.resolveHeaderDirectives(Module, /*File=*/std::nullopt);
340 
341   // If any headers are missing, we can't build this module. In most cases,
342   // diagnostics for this should have already been produced; we only get here
343   // if explicit stat information was provided.
344   // FIXME: If the name resolves to a file with different stat information,
345   // produce a better diagnostic.
346   if (!Module->MissingHeaders.empty()) {
347     auto &MissingHeader = Module->MissingHeaders.front();
348     Diag.Report(MissingHeader.FileNameLoc, diag::err_module_header_missing)
349       << MissingHeader.IsUmbrella << MissingHeader.FileName;
350     return std::error_code();
351   }
352 
353   // Add includes for each of these headers.
354   for (auto HK : {Module::HK_Normal, Module::HK_Private}) {
355     for (Module::Header &H : Module->Headers[HK]) {
356       Module->addTopHeader(H.Entry);
357       // Use the path as specified in the module map file. We'll look for this
358       // file relative to the module build directory (the directory containing
359       // the module map file) so this will find the same file that we found
360       // while parsing the module map.
361       addHeaderInclude(H.PathRelativeToRootModuleDirectory, Includes, LangOpts,
362                        Module->IsExternC);
363     }
364   }
365   // Note that Module->PrivateHeaders will not be a TopHeader.
366 
367   if (Module::Header UmbrellaHeader = Module->getUmbrellaHeader()) {
368     Module->addTopHeader(UmbrellaHeader.Entry);
369     if (Module->Parent)
370       // Include the umbrella header for submodules.
371       addHeaderInclude(UmbrellaHeader.PathRelativeToRootModuleDirectory,
372                        Includes, LangOpts, Module->IsExternC);
373   } else if (Module::DirectoryName UmbrellaDir = Module->getUmbrellaDir()) {
374     // Add all of the headers we find in this subdirectory.
375     std::error_code EC;
376     SmallString<128> DirNative;
377     llvm::sys::path::native(UmbrellaDir.Entry->getName(), DirNative);
378 
379     llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
380     SmallVector<
381         std::pair<std::string, OptionalFileEntryRefDegradesToFileEntryPtr>, 8>
382         Headers;
383     for (llvm::vfs::recursive_directory_iterator Dir(FS, DirNative, EC), End;
384          Dir != End && !EC; Dir.increment(EC)) {
385       // Check whether this entry has an extension typically associated with
386       // headers.
387       if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
388                .Cases(".h", ".H", ".hh", ".hpp", true)
389                .Default(false))
390         continue;
391 
392       auto Header = FileMgr.getOptionalFileRef(Dir->path());
393       // FIXME: This shouldn't happen unless there is a file system race. Is
394       // that worth diagnosing?
395       if (!Header)
396         continue;
397 
398       // If this header is marked 'unavailable' in this module, don't include
399       // it.
400       if (ModMap.isHeaderUnavailableInModule(*Header, Module))
401         continue;
402 
403       // Compute the relative path from the directory to this file.
404       SmallVector<StringRef, 16> Components;
405       auto PathIt = llvm::sys::path::rbegin(Dir->path());
406       for (int I = 0; I != Dir.level() + 1; ++I, ++PathIt)
407         Components.push_back(*PathIt);
408       SmallString<128> RelativeHeader(
409           UmbrellaDir.PathRelativeToRootModuleDirectory);
410       for (auto It = Components.rbegin(), End = Components.rend(); It != End;
411            ++It)
412         llvm::sys::path::append(RelativeHeader, *It);
413 
414       std::string RelName = RelativeHeader.c_str();
415       Headers.push_back(std::make_pair(RelName, *Header));
416     }
417 
418     if (EC)
419       return EC;
420 
421     // Sort header paths and make the header inclusion order deterministic
422     // across different OSs and filesystems.
423     llvm::sort(Headers, llvm::less_first());
424     for (auto &H : Headers) {
425       // Include this header as part of the umbrella directory.
426       Module->addTopHeader(H.second);
427       addHeaderInclude(H.first, Includes, LangOpts, Module->IsExternC);
428     }
429   }
430 
431   // Recurse into submodules.
432   for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
433                                       SubEnd = Module->submodule_end();
434        Sub != SubEnd; ++Sub)
435     if (std::error_code Err = collectModuleHeaderIncludes(
436             LangOpts, FileMgr, Diag, ModMap, *Sub, Includes))
437       return Err;
438 
439   return std::error_code();
440 }
441 
442 static bool loadModuleMapForModuleBuild(CompilerInstance &CI, bool IsSystem,
443                                         bool IsPreprocessed,
444                                         std::string &PresumedModuleMapFile,
445                                         unsigned &Offset) {
446   auto &SrcMgr = CI.getSourceManager();
447   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
448 
449   // Map the current input to a file.
450   FileID ModuleMapID = SrcMgr.getMainFileID();
451   const FileEntry *ModuleMap = SrcMgr.getFileEntryForID(ModuleMapID);
452 
453   // If the module map is preprocessed, handle the initial line marker;
454   // line directives are not part of the module map syntax in general.
455   Offset = 0;
456   if (IsPreprocessed) {
457     SourceLocation EndOfLineMarker =
458         ReadOriginalFileName(CI, PresumedModuleMapFile, /*IsModuleMap*/ true);
459     if (EndOfLineMarker.isValid())
460       Offset = CI.getSourceManager().getDecomposedLoc(EndOfLineMarker).second;
461   }
462 
463   // Load the module map file.
464   if (HS.loadModuleMapFile(ModuleMap, IsSystem, ModuleMapID, &Offset,
465                            PresumedModuleMapFile))
466     return true;
467 
468   if (SrcMgr.getBufferOrFake(ModuleMapID).getBufferSize() == Offset)
469     Offset = 0;
470 
471   // Infer framework module if possible.
472   if (HS.getModuleMap().canInferFrameworkModule(ModuleMap->getDir())) {
473     SmallString<128> InferredFrameworkPath = ModuleMap->getDir()->getName();
474     llvm::sys::path::append(InferredFrameworkPath,
475                             CI.getLangOpts().ModuleName + ".framework");
476     if (auto Dir = CI.getFileManager().getDirectory(InferredFrameworkPath))
477       (void)HS.getModuleMap().inferFrameworkModule(*Dir, IsSystem, nullptr);
478   }
479 
480   return false;
481 }
482 
483 static Module *prepareToBuildModule(CompilerInstance &CI,
484                                     StringRef ModuleMapFilename) {
485   if (CI.getLangOpts().CurrentModule.empty()) {
486     CI.getDiagnostics().Report(diag::err_missing_module_name);
487 
488     // FIXME: Eventually, we could consider asking whether there was just
489     // a single module described in the module map, and use that as a
490     // default. Then it would be fairly trivial to just "compile" a module
491     // map with a single module (the common case).
492     return nullptr;
493   }
494 
495   // Dig out the module definition.
496   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
497   Module *M = HS.lookupModule(CI.getLangOpts().CurrentModule, SourceLocation(),
498                               /*AllowSearch=*/true);
499   if (!M) {
500     CI.getDiagnostics().Report(diag::err_missing_module)
501       << CI.getLangOpts().CurrentModule << ModuleMapFilename;
502 
503     return nullptr;
504   }
505 
506   // Check whether we can build this module at all.
507   if (Preprocessor::checkModuleIsAvailable(CI.getLangOpts(), CI.getTarget(),
508                                            CI.getDiagnostics(), M))
509     return nullptr;
510 
511   // Inform the preprocessor that includes from within the input buffer should
512   // be resolved relative to the build directory of the module map file.
513   CI.getPreprocessor().setMainFileDir(M->Directory);
514 
515   // If the module was inferred from a different module map (via an expanded
516   // umbrella module definition), track that fact.
517   // FIXME: It would be preferable to fill this in as part of processing
518   // the module map, rather than adding it after the fact.
519   StringRef OriginalModuleMapName = CI.getFrontendOpts().OriginalModuleMap;
520   if (!OriginalModuleMapName.empty()) {
521     auto OriginalModuleMap =
522         CI.getFileManager().getFile(OriginalModuleMapName,
523                                     /*openFile*/ true);
524     if (!OriginalModuleMap) {
525       CI.getDiagnostics().Report(diag::err_module_map_not_found)
526         << OriginalModuleMapName;
527       return nullptr;
528     }
529     if (*OriginalModuleMap != CI.getSourceManager().getFileEntryForID(
530                                  CI.getSourceManager().getMainFileID())) {
531       M->IsInferred = true;
532       CI.getPreprocessor().getHeaderSearchInfo().getModuleMap()
533         .setInferredModuleAllowedBy(M, *OriginalModuleMap);
534     }
535   }
536 
537   // If we're being run from the command-line, the module build stack will not
538   // have been filled in yet, so complete it now in order to allow us to detect
539   // module cycles.
540   SourceManager &SourceMgr = CI.getSourceManager();
541   if (SourceMgr.getModuleBuildStack().empty())
542     SourceMgr.pushModuleBuildStack(CI.getLangOpts().CurrentModule,
543                                    FullSourceLoc(SourceLocation(), SourceMgr));
544   return M;
545 }
546 
547 /// Compute the input buffer that should be used to build the specified module.
548 static std::unique_ptr<llvm::MemoryBuffer>
549 getInputBufferForModule(CompilerInstance &CI, Module *M) {
550   FileManager &FileMgr = CI.getFileManager();
551 
552   // Collect the set of #includes we need to build the module.
553   SmallString<256> HeaderContents;
554   std::error_code Err = std::error_code();
555   if (Module::Header UmbrellaHeader = M->getUmbrellaHeader())
556     addHeaderInclude(UmbrellaHeader.PathRelativeToRootModuleDirectory,
557                      HeaderContents, CI.getLangOpts(), M->IsExternC);
558   Err = collectModuleHeaderIncludes(
559       CI.getLangOpts(), FileMgr, CI.getDiagnostics(),
560       CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(), M,
561       HeaderContents);
562 
563   if (Err) {
564     CI.getDiagnostics().Report(diag::err_module_cannot_create_includes)
565       << M->getFullModuleName() << Err.message();
566     return nullptr;
567   }
568 
569   return llvm::MemoryBuffer::getMemBufferCopy(
570       HeaderContents, Module::getModuleInputBufferName());
571 }
572 
573 bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
574                                      const FrontendInputFile &RealInput) {
575   FrontendInputFile Input(RealInput);
576   assert(!Instance && "Already processing a source file!");
577   assert(!Input.isEmpty() && "Unexpected empty filename!");
578   setCurrentInput(Input);
579   setCompilerInstance(&CI);
580 
581   bool HasBegunSourceFile = false;
582   bool ReplayASTFile = Input.getKind().getFormat() == InputKind::Precompiled &&
583                        usesPreprocessorOnly();
584 
585   // If we fail, reset state since the client will not end up calling the
586   // matching EndSourceFile(). All paths that return true should release this.
587   auto FailureCleanup = llvm::make_scope_exit([&]() {
588     if (HasBegunSourceFile)
589       CI.getDiagnosticClient().EndSourceFile();
590     CI.setASTConsumer(nullptr);
591     CI.clearOutputFiles(/*EraseFiles=*/true);
592     CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
593     setCurrentInput(FrontendInputFile());
594     setCompilerInstance(nullptr);
595   });
596 
597   if (!BeginInvocation(CI))
598     return false;
599 
600   // If we're replaying the build of an AST file, import it and set up
601   // the initial state from its build.
602   if (ReplayASTFile) {
603     IntrusiveRefCntPtr<DiagnosticsEngine> Diags(&CI.getDiagnostics());
604 
605     // The AST unit populates its own diagnostics engine rather than ours.
606     IntrusiveRefCntPtr<DiagnosticsEngine> ASTDiags(
607         new DiagnosticsEngine(Diags->getDiagnosticIDs(),
608                               &Diags->getDiagnosticOptions()));
609     ASTDiags->setClient(Diags->getClient(), /*OwnsClient*/false);
610 
611     // FIXME: What if the input is a memory buffer?
612     StringRef InputFile = Input.getFile();
613 
614     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
615         std::string(InputFile), CI.getPCHContainerReader(),
616         ASTUnit::LoadPreprocessorOnly, ASTDiags, CI.getFileSystemOpts(),
617         CI.getCodeGenOpts().DebugTypeExtRefs);
618     if (!AST)
619       return false;
620 
621     // Options relating to how we treat the input (but not what we do with it)
622     // are inherited from the AST unit.
623     CI.getHeaderSearchOpts() = AST->getHeaderSearchOpts();
624     CI.getPreprocessorOpts() = AST->getPreprocessorOpts();
625     CI.getLangOpts() = AST->getLangOpts();
626 
627     // Set the shared objects, these are reset when we finish processing the
628     // file, otherwise the CompilerInstance will happily destroy them.
629     CI.setFileManager(&AST->getFileManager());
630     CI.createSourceManager(CI.getFileManager());
631     CI.getSourceManager().initializeForReplay(AST->getSourceManager());
632 
633     // Preload all the module files loaded transitively by the AST unit. Also
634     // load all module map files that were parsed as part of building the AST
635     // unit.
636     if (auto ASTReader = AST->getASTReader()) {
637       auto &MM = ASTReader->getModuleManager();
638       auto &PrimaryModule = MM.getPrimaryModule();
639 
640       for (serialization::ModuleFile &MF : MM)
641         if (&MF != &PrimaryModule)
642           CI.getFrontendOpts().ModuleFiles.push_back(MF.FileName);
643 
644       ASTReader->visitTopLevelModuleMaps(PrimaryModule, [&](FileEntryRef FE) {
645         CI.getFrontendOpts().ModuleMapFiles.push_back(
646             std::string(FE.getName()));
647       });
648     }
649 
650     // Set up the input file for replay purposes.
651     auto Kind = AST->getInputKind();
652     if (Kind.getFormat() == InputKind::ModuleMap) {
653       Module *ASTModule =
654           AST->getPreprocessor().getHeaderSearchInfo().lookupModule(
655               AST->getLangOpts().CurrentModule, SourceLocation(),
656               /*AllowSearch*/ false);
657       assert(ASTModule && "module file does not define its own module");
658       Input = FrontendInputFile(ASTModule->PresumedModuleMapFile, Kind);
659     } else {
660       auto &OldSM = AST->getSourceManager();
661       FileID ID = OldSM.getMainFileID();
662       if (auto *File = OldSM.getFileEntryForID(ID))
663         Input = FrontendInputFile(File->getName(), Kind);
664       else
665         Input = FrontendInputFile(OldSM.getBufferOrFake(ID), Kind);
666     }
667     setCurrentInput(Input, std::move(AST));
668   }
669 
670   // AST files follow a very different path, since they share objects via the
671   // AST unit.
672   if (Input.getKind().getFormat() == InputKind::Precompiled) {
673     assert(!usesPreprocessorOnly() && "this case was handled above");
674     assert(hasASTFileSupport() &&
675            "This action does not have AST file support!");
676 
677     IntrusiveRefCntPtr<DiagnosticsEngine> Diags(&CI.getDiagnostics());
678 
679     // FIXME: What if the input is a memory buffer?
680     StringRef InputFile = Input.getFile();
681 
682     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
683         std::string(InputFile), CI.getPCHContainerReader(),
684         ASTUnit::LoadEverything, Diags, CI.getFileSystemOpts(),
685         CI.getCodeGenOpts().DebugTypeExtRefs);
686 
687     if (!AST)
688       return false;
689 
690     // Inform the diagnostic client we are processing a source file.
691     CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), nullptr);
692     HasBegunSourceFile = true;
693 
694     // Set the shared objects, these are reset when we finish processing the
695     // file, otherwise the CompilerInstance will happily destroy them.
696     CI.setFileManager(&AST->getFileManager());
697     CI.setSourceManager(&AST->getSourceManager());
698     CI.setPreprocessor(AST->getPreprocessorPtr());
699     Preprocessor &PP = CI.getPreprocessor();
700     PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
701                                            PP.getLangOpts());
702     CI.setASTContext(&AST->getASTContext());
703 
704     setCurrentInput(Input, std::move(AST));
705 
706     // Initialize the action.
707     if (!BeginSourceFileAction(CI))
708       return false;
709 
710     // Create the AST consumer.
711     CI.setASTConsumer(CreateWrappedASTConsumer(CI, InputFile));
712     if (!CI.hasASTConsumer())
713       return false;
714 
715     FailureCleanup.release();
716     return true;
717   }
718 
719   // Set up the file and source managers, if needed.
720   if (!CI.hasFileManager()) {
721     if (!CI.createFileManager()) {
722       return false;
723     }
724   }
725   if (!CI.hasSourceManager()) {
726     CI.createSourceManager(CI.getFileManager());
727     if (CI.getDiagnosticOpts().getFormat() == DiagnosticOptions::SARIF) {
728       static_cast<SARIFDiagnosticPrinter *>(&CI.getDiagnosticClient())
729           ->setSarifWriter(
730               std::make_unique<SarifDocumentWriter>(CI.getSourceManager()));
731     }
732   }
733 
734   // Set up embedding for any specified files. Do this before we load any
735   // source files, including the primary module map for the compilation.
736   for (const auto &F : CI.getFrontendOpts().ModulesEmbedFiles) {
737     if (auto FE = CI.getFileManager().getFile(F, /*openFile*/true))
738       CI.getSourceManager().setFileIsTransient(*FE);
739     else
740       CI.getDiagnostics().Report(diag::err_modules_embed_file_not_found) << F;
741   }
742   if (CI.getFrontendOpts().ModulesEmbedAllFiles)
743     CI.getSourceManager().setAllFilesAreTransient(true);
744 
745   // IR files bypass the rest of initialization.
746   if (Input.getKind().getLanguage() == Language::LLVM_IR) {
747     assert(hasIRSupport() &&
748            "This action does not have IR file support!");
749 
750     // Inform the diagnostic client we are processing a source file.
751     CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), nullptr);
752     HasBegunSourceFile = true;
753 
754     // Initialize the action.
755     if (!BeginSourceFileAction(CI))
756       return false;
757 
758     // Initialize the main file entry.
759     if (!CI.InitializeSourceManager(CurrentInput))
760       return false;
761 
762     FailureCleanup.release();
763     return true;
764   }
765 
766   // If the implicit PCH include is actually a directory, rather than
767   // a single file, search for a suitable PCH file in that directory.
768   if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
769     FileManager &FileMgr = CI.getFileManager();
770     PreprocessorOptions &PPOpts = CI.getPreprocessorOpts();
771     StringRef PCHInclude = PPOpts.ImplicitPCHInclude;
772     std::string SpecificModuleCachePath = CI.getSpecificModuleCachePath();
773     if (auto PCHDir = FileMgr.getOptionalDirectoryRef(PCHInclude)) {
774       std::error_code EC;
775       SmallString<128> DirNative;
776       llvm::sys::path::native(PCHDir->getName(), DirNative);
777       bool Found = false;
778       llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
779       for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC),
780                                          DirEnd;
781            Dir != DirEnd && !EC; Dir.increment(EC)) {
782         // Check whether this is an acceptable AST file.
783         if (ASTReader::isAcceptableASTFile(
784                 Dir->path(), FileMgr, CI.getModuleCache(),
785                 CI.getPCHContainerReader(), CI.getLangOpts(),
786                 CI.getTargetOpts(), CI.getPreprocessorOpts(),
787                 SpecificModuleCachePath, /*RequireStrictOptionMatches=*/true)) {
788           PPOpts.ImplicitPCHInclude = std::string(Dir->path());
789           Found = true;
790           break;
791         }
792       }
793 
794       if (!Found) {
795         CI.getDiagnostics().Report(diag::err_fe_no_pch_in_dir) << PCHInclude;
796         return false;
797       }
798     }
799   }
800 
801   // Set up the preprocessor if needed. When parsing model files the
802   // preprocessor of the original source is reused.
803   if (!isModelParsingAction())
804     CI.createPreprocessor(getTranslationUnitKind());
805 
806   // Inform the diagnostic client we are processing a source file.
807   CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(),
808                                            &CI.getPreprocessor());
809   HasBegunSourceFile = true;
810 
811   // Handle C++20 header units.
812   // Here, the user has the option to specify that the header name should be
813   // looked up in the pre-processor search paths (and the main filename as
814   // passed by the driver might therefore be incomplete until that look-up).
815   if (CI.getLangOpts().CPlusPlusModules && Input.getKind().isHeaderUnit() &&
816       !Input.getKind().isPreprocessed()) {
817     StringRef FileName = Input.getFile();
818     InputKind Kind = Input.getKind();
819     if (Kind.getHeaderUnitKind() != InputKind::HeaderUnit_Abs) {
820       assert(CI.hasPreprocessor() &&
821              "trying to build a header unit without a Pre-processor?");
822       HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
823       // Relative searches begin from CWD.
824       const DirectoryEntry *Dir = nullptr;
825       if (auto DirOrErr = CI.getFileManager().getDirectory("."))
826         Dir = *DirOrErr;
827       SmallVector<std::pair<const FileEntry *, const DirectoryEntry *>, 1> CWD;
828       CWD.push_back({nullptr, Dir});
829       OptionalFileEntryRef FE =
830           HS.LookupFile(FileName, SourceLocation(),
831                         /*Angled*/ Input.getKind().getHeaderUnitKind() ==
832                             InputKind::HeaderUnit_System,
833                         nullptr, nullptr, CWD, nullptr, nullptr, nullptr,
834                         nullptr, nullptr, nullptr);
835       if (!FE) {
836         CI.getDiagnostics().Report(diag::err_module_header_file_not_found)
837             << FileName;
838         return false;
839       }
840       // We now have the filename...
841       FileName = FE->getFileEntry().getName();
842       // ... still a header unit, but now use the path as written.
843       Kind = Input.getKind().withHeaderUnit(InputKind::HeaderUnit_Abs);
844       Input = FrontendInputFile(FileName, Kind, Input.isSystem());
845     }
846     // Unless the user has overridden the name, the header unit module name is
847     // the pathname for the file.
848     if (CI.getLangOpts().ModuleName.empty())
849       CI.getLangOpts().ModuleName = std::string(FileName);
850     CI.getLangOpts().CurrentModule = CI.getLangOpts().ModuleName;
851   }
852 
853   if (!CI.InitializeSourceManager(Input))
854     return false;
855 
856   if (CI.getLangOpts().CPlusPlusModules && Input.getKind().isHeaderUnit() &&
857       Input.getKind().isPreprocessed() && !usesPreprocessorOnly()) {
858     // We have an input filename like foo.iih, but we want to find the right
859     // module name (and original file, to build the map entry).
860     // Check if the first line specifies the original source file name with a
861     // linemarker.
862     std::string PresumedInputFile = std::string(getCurrentFileOrBufferName());
863     ReadOriginalFileName(CI, PresumedInputFile);
864     // Unless the user overrides this, the module name is the name by which the
865     // original file was known.
866     if (CI.getLangOpts().ModuleName.empty())
867       CI.getLangOpts().ModuleName = std::string(PresumedInputFile);
868     CI.getLangOpts().CurrentModule = CI.getLangOpts().ModuleName;
869   }
870 
871   // For module map files, we first parse the module map and synthesize a
872   // "<module-includes>" buffer before more conventional processing.
873   if (Input.getKind().getFormat() == InputKind::ModuleMap) {
874     CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleMap);
875 
876     std::string PresumedModuleMapFile;
877     unsigned OffsetToContents;
878     if (loadModuleMapForModuleBuild(CI, Input.isSystem(),
879                                     Input.isPreprocessed(),
880                                     PresumedModuleMapFile, OffsetToContents))
881       return false;
882 
883     auto *CurrentModule = prepareToBuildModule(CI, Input.getFile());
884     if (!CurrentModule)
885       return false;
886 
887     CurrentModule->PresumedModuleMapFile = PresumedModuleMapFile;
888 
889     if (OffsetToContents)
890       // If the module contents are in the same file, skip to them.
891       CI.getPreprocessor().setSkipMainFilePreamble(OffsetToContents, true);
892     else {
893       // Otherwise, convert the module description to a suitable input buffer.
894       auto Buffer = getInputBufferForModule(CI, CurrentModule);
895       if (!Buffer)
896         return false;
897 
898       // Reinitialize the main file entry to refer to the new input.
899       auto Kind = CurrentModule->IsSystem ? SrcMgr::C_System : SrcMgr::C_User;
900       auto &SourceMgr = CI.getSourceManager();
901       auto BufferID = SourceMgr.createFileID(std::move(Buffer), Kind);
902       assert(BufferID.isValid() && "couldn't create module buffer ID");
903       SourceMgr.setMainFileID(BufferID);
904     }
905   }
906 
907   // Initialize the action.
908   if (!BeginSourceFileAction(CI))
909     return false;
910 
911   // If we were asked to load any module map files, do so now.
912   for (const auto &Filename : CI.getFrontendOpts().ModuleMapFiles) {
913     if (auto File = CI.getFileManager().getFile(Filename))
914       CI.getPreprocessor().getHeaderSearchInfo().loadModuleMapFile(
915           *File, /*IsSystem*/false);
916     else
917       CI.getDiagnostics().Report(diag::err_module_map_not_found) << Filename;
918   }
919 
920   // If compiling implementation of a module, load its module map file now.
921   (void)CI.getPreprocessor().getCurrentModuleImplementation();
922 
923   // Add a module declaration scope so that modules from -fmodule-map-file
924   // arguments may shadow modules found implicitly in search paths.
925   CI.getPreprocessor()
926       .getHeaderSearchInfo()
927       .getModuleMap()
928       .finishModuleDeclarationScope();
929 
930   // Create the AST context and consumer unless this is a preprocessor only
931   // action.
932   if (!usesPreprocessorOnly()) {
933     // Parsing a model file should reuse the existing ASTContext.
934     if (!isModelParsingAction())
935       CI.createASTContext();
936 
937     // For preprocessed files, check if the first line specifies the original
938     // source file name with a linemarker.
939     std::string PresumedInputFile = std::string(getCurrentFileOrBufferName());
940     if (Input.isPreprocessed())
941       ReadOriginalFileName(CI, PresumedInputFile);
942 
943     std::unique_ptr<ASTConsumer> Consumer =
944         CreateWrappedASTConsumer(CI, PresumedInputFile);
945     if (!Consumer)
946       return false;
947 
948     // FIXME: should not overwrite ASTMutationListener when parsing model files?
949     if (!isModelParsingAction())
950       CI.getASTContext().setASTMutationListener(Consumer->GetASTMutationListener());
951 
952     if (!CI.getPreprocessorOpts().ChainedIncludes.empty()) {
953       // Convert headers to PCH and chain them.
954       IntrusiveRefCntPtr<ExternalSemaSource> source, FinalReader;
955       source = createChainedIncludesSource(CI, FinalReader);
956       if (!source)
957         return false;
958       CI.setASTReader(static_cast<ASTReader *>(FinalReader.get()));
959       CI.getASTContext().setExternalSource(source);
960     } else if (CI.getLangOpts().Modules ||
961                !CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
962       // Use PCM or PCH.
963       assert(hasPCHSupport() && "This action does not have PCH support!");
964       ASTDeserializationListener *DeserialListener =
965           Consumer->GetASTDeserializationListener();
966       bool DeleteDeserialListener = false;
967       if (CI.getPreprocessorOpts().DumpDeserializedPCHDecls) {
968         DeserialListener = new DeserializedDeclsDumper(DeserialListener,
969                                                        DeleteDeserialListener);
970         DeleteDeserialListener = true;
971       }
972       if (!CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn.empty()) {
973         DeserialListener = new DeserializedDeclsChecker(
974             CI.getASTContext(),
975             CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn,
976             DeserialListener, DeleteDeserialListener);
977         DeleteDeserialListener = true;
978       }
979       if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
980         CI.createPCHExternalASTSource(
981             CI.getPreprocessorOpts().ImplicitPCHInclude,
982             CI.getPreprocessorOpts().DisablePCHOrModuleValidation,
983             CI.getPreprocessorOpts().AllowPCHWithCompilerErrors,
984             DeserialListener, DeleteDeserialListener);
985         if (!CI.getASTContext().getExternalSource())
986           return false;
987       }
988       // If modules are enabled, create the AST reader before creating
989       // any builtins, so that all declarations know that they might be
990       // extended by an external source.
991       if (CI.getLangOpts().Modules || !CI.hasASTContext() ||
992           !CI.getASTContext().getExternalSource()) {
993         CI.createASTReader();
994         CI.getASTReader()->setDeserializationListener(DeserialListener,
995                                                       DeleteDeserialListener);
996       }
997     }
998 
999     CI.setASTConsumer(std::move(Consumer));
1000     if (!CI.hasASTConsumer())
1001       return false;
1002   }
1003 
1004   // Initialize built-in info as long as we aren't using an external AST
1005   // source.
1006   if (CI.getLangOpts().Modules || !CI.hasASTContext() ||
1007       !CI.getASTContext().getExternalSource()) {
1008     Preprocessor &PP = CI.getPreprocessor();
1009     PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
1010                                            PP.getLangOpts());
1011   } else {
1012     // FIXME: If this is a problem, recover from it by creating a multiplex
1013     // source.
1014     assert((!CI.getLangOpts().Modules || CI.getASTReader()) &&
1015            "modules enabled but created an external source that "
1016            "doesn't support modules");
1017   }
1018 
1019   // If we were asked to load any module files, do so now.
1020   for (const auto &ModuleFile : CI.getFrontendOpts().ModuleFiles)
1021     if (!CI.loadModuleFile(ModuleFile))
1022       return false;
1023 
1024   // If there is a layout overrides file, attach an external AST source that
1025   // provides the layouts from that file.
1026   if (!CI.getFrontendOpts().OverrideRecordLayoutsFile.empty() &&
1027       CI.hasASTContext() && !CI.getASTContext().getExternalSource()) {
1028     IntrusiveRefCntPtr<ExternalASTSource>
1029       Override(new LayoutOverrideSource(
1030                      CI.getFrontendOpts().OverrideRecordLayoutsFile));
1031     CI.getASTContext().setExternalSource(Override);
1032   }
1033 
1034   // Setup HLSL External Sema Source
1035   if (CI.getLangOpts().HLSL && CI.hasASTContext()) {
1036     IntrusiveRefCntPtr<ExternalSemaSource> HLSLSema(
1037         new HLSLExternalSemaSource());
1038     if (auto *SemaSource = dyn_cast_if_present<ExternalSemaSource>(
1039             CI.getASTContext().getExternalSource())) {
1040       IntrusiveRefCntPtr<ExternalSemaSource> MultiSema(
1041           new MultiplexExternalSemaSource(SemaSource, HLSLSema.get()));
1042       CI.getASTContext().setExternalSource(MultiSema);
1043     } else
1044       CI.getASTContext().setExternalSource(HLSLSema);
1045   }
1046 
1047   FailureCleanup.release();
1048   return true;
1049 }
1050 
1051 llvm::Error FrontendAction::Execute() {
1052   CompilerInstance &CI = getCompilerInstance();
1053 
1054   if (CI.hasFrontendTimer()) {
1055     llvm::TimeRegion Timer(CI.getFrontendTimer());
1056     ExecuteAction();
1057   }
1058   else ExecuteAction();
1059 
1060   // If we are supposed to rebuild the global module index, do so now unless
1061   // there were any module-build failures.
1062   if (CI.shouldBuildGlobalModuleIndex() && CI.hasFileManager() &&
1063       CI.hasPreprocessor()) {
1064     StringRef Cache =
1065         CI.getPreprocessor().getHeaderSearchInfo().getModuleCachePath();
1066     if (!Cache.empty()) {
1067       if (llvm::Error Err = GlobalModuleIndex::writeIndex(
1068               CI.getFileManager(), CI.getPCHContainerReader(), Cache)) {
1069         // FIXME this drops the error on the floor, but
1070         // Index/pch-from-libclang.c seems to rely on dropping at least some of
1071         // the error conditions!
1072         consumeError(std::move(Err));
1073       }
1074     }
1075   }
1076 
1077   return llvm::Error::success();
1078 }
1079 
1080 void FrontendAction::EndSourceFile() {
1081   CompilerInstance &CI = getCompilerInstance();
1082 
1083   // Inform the diagnostic client we are done with this source file.
1084   CI.getDiagnosticClient().EndSourceFile();
1085 
1086   // Inform the preprocessor we are done.
1087   if (CI.hasPreprocessor())
1088     CI.getPreprocessor().EndSourceFile();
1089 
1090   // Finalize the action.
1091   EndSourceFileAction();
1092 
1093   // Sema references the ast consumer, so reset sema first.
1094   //
1095   // FIXME: There is more per-file stuff we could just drop here?
1096   bool DisableFree = CI.getFrontendOpts().DisableFree;
1097   if (DisableFree) {
1098     CI.resetAndLeakSema();
1099     CI.resetAndLeakASTContext();
1100     llvm::BuryPointer(CI.takeASTConsumer().get());
1101   } else {
1102     CI.setSema(nullptr);
1103     CI.setASTContext(nullptr);
1104     CI.setASTConsumer(nullptr);
1105   }
1106 
1107   if (CI.getFrontendOpts().ShowStats) {
1108     llvm::errs() << "\nSTATISTICS FOR '" << getCurrentFileOrBufferName() << "':\n";
1109     CI.getPreprocessor().PrintStats();
1110     CI.getPreprocessor().getIdentifierTable().PrintStats();
1111     CI.getPreprocessor().getHeaderSearchInfo().PrintStats();
1112     CI.getSourceManager().PrintStats();
1113     llvm::errs() << "\n";
1114   }
1115 
1116   // Cleanup the output streams, and erase the output files if instructed by the
1117   // FrontendAction.
1118   CI.clearOutputFiles(/*EraseFiles=*/shouldEraseOutputFiles());
1119 
1120   if (isCurrentFileAST()) {
1121     if (DisableFree) {
1122       CI.resetAndLeakPreprocessor();
1123       CI.resetAndLeakSourceManager();
1124       CI.resetAndLeakFileManager();
1125       llvm::BuryPointer(std::move(CurrentASTUnit));
1126     } else {
1127       CI.setPreprocessor(nullptr);
1128       CI.setSourceManager(nullptr);
1129       CI.setFileManager(nullptr);
1130     }
1131   }
1132 
1133   setCompilerInstance(nullptr);
1134   setCurrentInput(FrontendInputFile());
1135   CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
1136 }
1137 
1138 bool FrontendAction::shouldEraseOutputFiles() {
1139   return getCompilerInstance().getDiagnostics().hasErrorOccurred();
1140 }
1141 
1142 //===----------------------------------------------------------------------===//
1143 // Utility Actions
1144 //===----------------------------------------------------------------------===//
1145 
1146 void ASTFrontendAction::ExecuteAction() {
1147   CompilerInstance &CI = getCompilerInstance();
1148   if (!CI.hasPreprocessor())
1149     return;
1150 
1151   // FIXME: Move the truncation aspect of this into Sema, we delayed this till
1152   // here so the source manager would be initialized.
1153   if (hasCodeCompletionSupport() &&
1154       !CI.getFrontendOpts().CodeCompletionAt.FileName.empty())
1155     CI.createCodeCompletionConsumer();
1156 
1157   // Use a code completion consumer?
1158   CodeCompleteConsumer *CompletionConsumer = nullptr;
1159   if (CI.hasCodeCompletionConsumer())
1160     CompletionConsumer = &CI.getCodeCompletionConsumer();
1161 
1162   if (!CI.hasSema())
1163     CI.createSema(getTranslationUnitKind(), CompletionConsumer);
1164 
1165   ParseAST(CI.getSema(), CI.getFrontendOpts().ShowStats,
1166            CI.getFrontendOpts().SkipFunctionBodies);
1167 }
1168 
1169 void PluginASTAction::anchor() { }
1170 
1171 std::unique_ptr<ASTConsumer>
1172 PreprocessorFrontendAction::CreateASTConsumer(CompilerInstance &CI,
1173                                               StringRef InFile) {
1174   llvm_unreachable("Invalid CreateASTConsumer on preprocessor action!");
1175 }
1176 
1177 bool WrapperFrontendAction::PrepareToExecuteAction(CompilerInstance &CI) {
1178   return WrappedAction->PrepareToExecuteAction(CI);
1179 }
1180 std::unique_ptr<ASTConsumer>
1181 WrapperFrontendAction::CreateASTConsumer(CompilerInstance &CI,
1182                                          StringRef InFile) {
1183   return WrappedAction->CreateASTConsumer(CI, InFile);
1184 }
1185 bool WrapperFrontendAction::BeginInvocation(CompilerInstance &CI) {
1186   return WrappedAction->BeginInvocation(CI);
1187 }
1188 bool WrapperFrontendAction::BeginSourceFileAction(CompilerInstance &CI) {
1189   WrappedAction->setCurrentInput(getCurrentInput());
1190   WrappedAction->setCompilerInstance(&CI);
1191   auto Ret = WrappedAction->BeginSourceFileAction(CI);
1192   // BeginSourceFileAction may change CurrentInput, e.g. during module builds.
1193   setCurrentInput(WrappedAction->getCurrentInput());
1194   return Ret;
1195 }
1196 void WrapperFrontendAction::ExecuteAction() {
1197   WrappedAction->ExecuteAction();
1198 }
1199 void WrapperFrontendAction::EndSourceFile() { WrappedAction->EndSourceFile(); }
1200 void WrapperFrontendAction::EndSourceFileAction() {
1201   WrappedAction->EndSourceFileAction();
1202 }
1203 bool WrapperFrontendAction::shouldEraseOutputFiles() {
1204   return WrappedAction->shouldEraseOutputFiles();
1205 }
1206 
1207 bool WrapperFrontendAction::usesPreprocessorOnly() const {
1208   return WrappedAction->usesPreprocessorOnly();
1209 }
1210 TranslationUnitKind WrapperFrontendAction::getTranslationUnitKind() {
1211   return WrappedAction->getTranslationUnitKind();
1212 }
1213 bool WrapperFrontendAction::hasPCHSupport() const {
1214   return WrappedAction->hasPCHSupport();
1215 }
1216 bool WrapperFrontendAction::hasASTFileSupport() const {
1217   return WrappedAction->hasASTFileSupport();
1218 }
1219 bool WrapperFrontendAction::hasIRSupport() const {
1220   return WrappedAction->hasIRSupport();
1221 }
1222 bool WrapperFrontendAction::hasCodeCompletionSupport() const {
1223   return WrappedAction->hasCodeCompletionSupport();
1224 }
1225 
1226 WrapperFrontendAction::WrapperFrontendAction(
1227     std::unique_ptr<FrontendAction> WrappedAction)
1228   : WrappedAction(std::move(WrappedAction)) {}
1229