xref: /freebsd/contrib/llvm-project/clang/lib/Frontend/FrontendAction.cpp (revision f976241773df2260e6170317080761d1c5814fe5)
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/Frontend/ASTUnit.h"
14 #include "clang/Frontend/CompilerInstance.h"
15 #include "clang/Frontend/FrontendDiagnostic.h"
16 #include "clang/Frontend/FrontendPluginRegistry.h"
17 #include "clang/Frontend/LayoutOverrideSource.h"
18 #include "clang/Frontend/MultiplexConsumer.h"
19 #include "clang/Frontend/Utils.h"
20 #include "clang/Lex/HeaderSearch.h"
21 #include "clang/Lex/LiteralSupport.h"
22 #include "clang/Lex/Preprocessor.h"
23 #include "clang/Lex/PreprocessorOptions.h"
24 #include "clang/Parse/ParseAST.h"
25 #include "clang/Serialization/ASTDeserializationListener.h"
26 #include "clang/Serialization/ASTReader.h"
27 #include "clang/Serialization/GlobalModuleIndex.h"
28 #include "llvm/Support/BuryPointer.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include "llvm/Support/FileSystem.h"
31 #include "llvm/Support/Path.h"
32 #include "llvm/Support/Timer.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include <system_error>
35 using namespace clang;
36 
37 LLVM_INSTANTIATE_REGISTRY(FrontendPluginRegistry)
38 
39 namespace {
40 
41 class DelegatingDeserializationListener : public ASTDeserializationListener {
42   ASTDeserializationListener *Previous;
43   bool DeletePrevious;
44 
45 public:
46   explicit DelegatingDeserializationListener(
47       ASTDeserializationListener *Previous, bool DeletePrevious)
48       : Previous(Previous), DeletePrevious(DeletePrevious) {}
49   ~DelegatingDeserializationListener() override {
50     if (DeletePrevious)
51       delete Previous;
52   }
53 
54   void ReaderInitialized(ASTReader *Reader) override {
55     if (Previous)
56       Previous->ReaderInitialized(Reader);
57   }
58   void IdentifierRead(serialization::IdentID ID,
59                       IdentifierInfo *II) override {
60     if (Previous)
61       Previous->IdentifierRead(ID, II);
62   }
63   void TypeRead(serialization::TypeIdx Idx, QualType T) override {
64     if (Previous)
65       Previous->TypeRead(Idx, T);
66   }
67   void DeclRead(serialization::DeclID ID, const Decl *D) override {
68     if (Previous)
69       Previous->DeclRead(ID, D);
70   }
71   void SelectorRead(serialization::SelectorID ID, Selector Sel) override {
72     if (Previous)
73       Previous->SelectorRead(ID, Sel);
74   }
75   void MacroDefinitionRead(serialization::PreprocessedEntityID PPID,
76                            MacroDefinitionRecord *MD) override {
77     if (Previous)
78       Previous->MacroDefinitionRead(PPID, MD);
79   }
80 };
81 
82 /// Dumps deserialized declarations.
83 class DeserializedDeclsDumper : public DelegatingDeserializationListener {
84 public:
85   explicit DeserializedDeclsDumper(ASTDeserializationListener *Previous,
86                                    bool DeletePrevious)
87       : DelegatingDeserializationListener(Previous, DeletePrevious) {}
88 
89   void DeclRead(serialization::DeclID ID, const Decl *D) override {
90     llvm::outs() << "PCH DECL: " << D->getDeclKindName();
91     if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
92       llvm::outs() << " - ";
93       ND->printQualifiedName(llvm::outs());
94     }
95     llvm::outs() << "\n";
96 
97     DelegatingDeserializationListener::DeclRead(ID, D);
98   }
99 };
100 
101 /// Checks deserialized declarations and emits error if a name
102 /// matches one given in command-line using -error-on-deserialized-decl.
103 class DeserializedDeclsChecker : public DelegatingDeserializationListener {
104   ASTContext &Ctx;
105   std::set<std::string> NamesToCheck;
106 
107 public:
108   DeserializedDeclsChecker(ASTContext &Ctx,
109                            const std::set<std::string> &NamesToCheck,
110                            ASTDeserializationListener *Previous,
111                            bool DeletePrevious)
112       : DelegatingDeserializationListener(Previous, DeletePrevious), Ctx(Ctx),
113         NamesToCheck(NamesToCheck) {}
114 
115   void DeclRead(serialization::DeclID ID, const Decl *D) override {
116     if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
117       if (NamesToCheck.find(ND->getNameAsString()) != NamesToCheck.end()) {
118         unsigned DiagID
119           = Ctx.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error,
120                                                  "%0 was deserialized");
121         Ctx.getDiagnostics().Report(Ctx.getFullLoc(D->getLocation()), DiagID)
122             << ND->getNameAsString();
123       }
124 
125     DelegatingDeserializationListener::DeclRead(ID, D);
126   }
127 };
128 
129 } // end anonymous namespace
130 
131 FrontendAction::FrontendAction() : Instance(nullptr) {}
132 
133 FrontendAction::~FrontendAction() {}
134 
135 void FrontendAction::setCurrentInput(const FrontendInputFile &CurrentInput,
136                                      std::unique_ptr<ASTUnit> AST) {
137   this->CurrentInput = CurrentInput;
138   CurrentASTUnit = std::move(AST);
139 }
140 
141 Module *FrontendAction::getCurrentModule() const {
142   CompilerInstance &CI = getCompilerInstance();
143   return CI.getPreprocessor().getHeaderSearchInfo().lookupModule(
144       CI.getLangOpts().CurrentModule, /*AllowSearch*/false);
145 }
146 
147 std::unique_ptr<ASTConsumer>
148 FrontendAction::CreateWrappedASTConsumer(CompilerInstance &CI,
149                                          StringRef InFile) {
150   std::unique_ptr<ASTConsumer> Consumer = CreateASTConsumer(CI, InFile);
151   if (!Consumer)
152     return nullptr;
153 
154   // Validate -add-plugin args.
155   bool FoundAllPlugins = true;
156   for (const std::string &Arg : CI.getFrontendOpts().AddPluginActions) {
157     bool Found = false;
158     for (FrontendPluginRegistry::iterator it = FrontendPluginRegistry::begin(),
159                                           ie = FrontendPluginRegistry::end();
160          it != ie; ++it) {
161       if (it->getName() == Arg)
162         Found = true;
163     }
164     if (!Found) {
165       CI.getDiagnostics().Report(diag::err_fe_invalid_plugin_name) << Arg;
166       FoundAllPlugins = false;
167     }
168   }
169   if (!FoundAllPlugins)
170     return nullptr;
171 
172   // If there are no registered plugins we don't need to wrap the consumer
173   if (FrontendPluginRegistry::begin() == FrontendPluginRegistry::end())
174     return Consumer;
175 
176   // If this is a code completion run, avoid invoking the plugin consumers
177   if (CI.hasCodeCompletionConsumer())
178     return Consumer;
179 
180   // Collect the list of plugins that go before the main action (in Consumers)
181   // or after it (in AfterConsumers)
182   std::vector<std::unique_ptr<ASTConsumer>> Consumers;
183   std::vector<std::unique_ptr<ASTConsumer>> AfterConsumers;
184   for (FrontendPluginRegistry::iterator it = FrontendPluginRegistry::begin(),
185                                         ie = FrontendPluginRegistry::end();
186        it != ie; ++it) {
187     std::unique_ptr<PluginASTAction> P = it->instantiate();
188     PluginASTAction::ActionType ActionType = P->getActionType();
189     if (ActionType == PluginASTAction::Cmdline) {
190       // This is O(|plugins| * |add_plugins|), but since both numbers are
191       // way below 50 in practice, that's ok.
192       for (size_t i = 0, e = CI.getFrontendOpts().AddPluginActions.size();
193            i != e; ++i) {
194         if (it->getName() == CI.getFrontendOpts().AddPluginActions[i]) {
195           ActionType = PluginASTAction::AddAfterMainAction;
196           break;
197         }
198       }
199     }
200     if ((ActionType == PluginASTAction::AddBeforeMainAction ||
201          ActionType == PluginASTAction::AddAfterMainAction) &&
202         P->ParseArgs(CI, CI.getFrontendOpts().PluginArgs[it->getName()])) {
203       std::unique_ptr<ASTConsumer> PluginConsumer = P->CreateASTConsumer(CI, InFile);
204       if (ActionType == PluginASTAction::AddBeforeMainAction) {
205         Consumers.push_back(std::move(PluginConsumer));
206       } else {
207         AfterConsumers.push_back(std::move(PluginConsumer));
208       }
209     }
210   }
211 
212   // Add to Consumers the main consumer, then all the plugins that go after it
213   Consumers.push_back(std::move(Consumer));
214   for (auto &C : AfterConsumers) {
215     Consumers.push_back(std::move(C));
216   }
217 
218   return llvm::make_unique<MultiplexConsumer>(std::move(Consumers));
219 }
220 
221 /// For preprocessed files, if the first line is the linemarker and specifies
222 /// the original source file name, use that name as the input file name.
223 /// Returns the location of the first token after the line marker directive.
224 ///
225 /// \param CI The compiler instance.
226 /// \param InputFile Populated with the filename from the line marker.
227 /// \param IsModuleMap If \c true, add a line note corresponding to this line
228 ///        directive. (We need to do this because the directive will not be
229 ///        visited by the preprocessor.)
230 static SourceLocation ReadOriginalFileName(CompilerInstance &CI,
231                                            std::string &InputFile,
232                                            bool IsModuleMap = false) {
233   auto &SourceMgr = CI.getSourceManager();
234   auto MainFileID = SourceMgr.getMainFileID();
235 
236   bool Invalid = false;
237   const auto *MainFileBuf = SourceMgr.getBuffer(MainFileID, &Invalid);
238   if (Invalid)
239     return SourceLocation();
240 
241   std::unique_ptr<Lexer> RawLexer(
242       new Lexer(MainFileID, MainFileBuf, SourceMgr, CI.getLangOpts()));
243 
244   // If the first line has the syntax of
245   //
246   // # NUM "FILENAME"
247   //
248   // we use FILENAME as the input file name.
249   Token T;
250   if (RawLexer->LexFromRawLexer(T) || T.getKind() != tok::hash)
251     return SourceLocation();
252   if (RawLexer->LexFromRawLexer(T) || T.isAtStartOfLine() ||
253       T.getKind() != tok::numeric_constant)
254     return SourceLocation();
255 
256   unsigned LineNo;
257   SourceLocation LineNoLoc = T.getLocation();
258   if (IsModuleMap) {
259     llvm::SmallString<16> Buffer;
260     if (Lexer::getSpelling(LineNoLoc, Buffer, SourceMgr, CI.getLangOpts())
261             .getAsInteger(10, LineNo))
262       return SourceLocation();
263   }
264 
265   RawLexer->LexFromRawLexer(T);
266   if (T.isAtStartOfLine() || T.getKind() != tok::string_literal)
267     return SourceLocation();
268 
269   StringLiteralParser Literal(T, CI.getPreprocessor());
270   if (Literal.hadError)
271     return SourceLocation();
272   RawLexer->LexFromRawLexer(T);
273   if (T.isNot(tok::eof) && !T.isAtStartOfLine())
274     return SourceLocation();
275   InputFile = Literal.GetString().str();
276 
277   if (IsModuleMap)
278     CI.getSourceManager().AddLineNote(
279         LineNoLoc, LineNo, SourceMgr.getLineTableFilenameID(InputFile), false,
280         false, SrcMgr::C_User_ModuleMap);
281 
282   return T.getLocation();
283 }
284 
285 static SmallVectorImpl<char> &
286 operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
287   Includes.append(RHS.begin(), RHS.end());
288   return Includes;
289 }
290 
291 static void addHeaderInclude(StringRef HeaderName,
292                              SmallVectorImpl<char> &Includes,
293                              const LangOptions &LangOpts,
294                              bool IsExternC) {
295   if (IsExternC && LangOpts.CPlusPlus)
296     Includes += "extern \"C\" {\n";
297   if (LangOpts.ObjC)
298     Includes += "#import \"";
299   else
300     Includes += "#include \"";
301 
302   Includes += HeaderName;
303 
304   Includes += "\"\n";
305   if (IsExternC && LangOpts.CPlusPlus)
306     Includes += "}\n";
307 }
308 
309 /// Collect the set of header includes needed to construct the given
310 /// module and update the TopHeaders file set of the module.
311 ///
312 /// \param Module The module we're collecting includes from.
313 ///
314 /// \param Includes Will be augmented with the set of \#includes or \#imports
315 /// needed to load all of the named headers.
316 static std::error_code collectModuleHeaderIncludes(
317     const LangOptions &LangOpts, FileManager &FileMgr, DiagnosticsEngine &Diag,
318     ModuleMap &ModMap, clang::Module *Module, SmallVectorImpl<char> &Includes) {
319   // Don't collect any headers for unavailable modules.
320   if (!Module->isAvailable())
321     return std::error_code();
322 
323   // Resolve all lazy header directives to header files.
324   ModMap.resolveHeaderDirectives(Module);
325 
326   // If any headers are missing, we can't build this module. In most cases,
327   // diagnostics for this should have already been produced; we only get here
328   // if explicit stat information was provided.
329   // FIXME: If the name resolves to a file with different stat information,
330   // produce a better diagnostic.
331   if (!Module->MissingHeaders.empty()) {
332     auto &MissingHeader = Module->MissingHeaders.front();
333     Diag.Report(MissingHeader.FileNameLoc, diag::err_module_header_missing)
334       << MissingHeader.IsUmbrella << MissingHeader.FileName;
335     return std::error_code();
336   }
337 
338   // Add includes for each of these headers.
339   for (auto HK : {Module::HK_Normal, Module::HK_Private}) {
340     for (Module::Header &H : Module->Headers[HK]) {
341       Module->addTopHeader(H.Entry);
342       // Use the path as specified in the module map file. We'll look for this
343       // file relative to the module build directory (the directory containing
344       // the module map file) so this will find the same file that we found
345       // while parsing the module map.
346       addHeaderInclude(H.NameAsWritten, Includes, LangOpts, Module->IsExternC);
347     }
348   }
349   // Note that Module->PrivateHeaders will not be a TopHeader.
350 
351   if (Module::Header UmbrellaHeader = Module->getUmbrellaHeader()) {
352     Module->addTopHeader(UmbrellaHeader.Entry);
353     if (Module->Parent)
354       // Include the umbrella header for submodules.
355       addHeaderInclude(UmbrellaHeader.NameAsWritten, Includes, LangOpts,
356                        Module->IsExternC);
357   } else if (Module::DirectoryName UmbrellaDir = Module->getUmbrellaDir()) {
358     // Add all of the headers we find in this subdirectory.
359     std::error_code EC;
360     SmallString<128> DirNative;
361     llvm::sys::path::native(UmbrellaDir.Entry->getName(), DirNative);
362 
363     llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
364     for (llvm::vfs::recursive_directory_iterator Dir(FS, DirNative, EC), End;
365          Dir != End && !EC; Dir.increment(EC)) {
366       // Check whether this entry has an extension typically associated with
367       // headers.
368       if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
369                .Cases(".h", ".H", ".hh", ".hpp", true)
370                .Default(false))
371         continue;
372 
373       const FileEntry *Header = FileMgr.getFile(Dir->path());
374       // FIXME: This shouldn't happen unless there is a file system race. Is
375       // that worth diagnosing?
376       if (!Header)
377         continue;
378 
379       // If this header is marked 'unavailable' in this module, don't include
380       // it.
381       if (ModMap.isHeaderUnavailableInModule(Header, Module))
382         continue;
383 
384       // Compute the relative path from the directory to this file.
385       SmallVector<StringRef, 16> Components;
386       auto PathIt = llvm::sys::path::rbegin(Dir->path());
387       for (int I = 0; I != Dir.level() + 1; ++I, ++PathIt)
388         Components.push_back(*PathIt);
389       SmallString<128> RelativeHeader(UmbrellaDir.NameAsWritten);
390       for (auto It = Components.rbegin(), End = Components.rend(); It != End;
391            ++It)
392         llvm::sys::path::append(RelativeHeader, *It);
393 
394       // Include this header as part of the umbrella directory.
395       Module->addTopHeader(Header);
396       addHeaderInclude(RelativeHeader, Includes, LangOpts, Module->IsExternC);
397     }
398 
399     if (EC)
400       return EC;
401   }
402 
403   // Recurse into submodules.
404   for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
405                                       SubEnd = Module->submodule_end();
406        Sub != SubEnd; ++Sub)
407     if (std::error_code Err = collectModuleHeaderIncludes(
408             LangOpts, FileMgr, Diag, ModMap, *Sub, Includes))
409       return Err;
410 
411   return std::error_code();
412 }
413 
414 static bool loadModuleMapForModuleBuild(CompilerInstance &CI, bool IsSystem,
415                                         bool IsPreprocessed,
416                                         std::string &PresumedModuleMapFile,
417                                         unsigned &Offset) {
418   auto &SrcMgr = CI.getSourceManager();
419   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
420 
421   // Map the current input to a file.
422   FileID ModuleMapID = SrcMgr.getMainFileID();
423   const FileEntry *ModuleMap = SrcMgr.getFileEntryForID(ModuleMapID);
424 
425   // If the module map is preprocessed, handle the initial line marker;
426   // line directives are not part of the module map syntax in general.
427   Offset = 0;
428   if (IsPreprocessed) {
429     SourceLocation EndOfLineMarker =
430         ReadOriginalFileName(CI, PresumedModuleMapFile, /*IsModuleMap*/ true);
431     if (EndOfLineMarker.isValid())
432       Offset = CI.getSourceManager().getDecomposedLoc(EndOfLineMarker).second;
433   }
434 
435   // Load the module map file.
436   if (HS.loadModuleMapFile(ModuleMap, IsSystem, ModuleMapID, &Offset,
437                            PresumedModuleMapFile))
438     return true;
439 
440   if (SrcMgr.getBuffer(ModuleMapID)->getBufferSize() == Offset)
441     Offset = 0;
442 
443   return false;
444 }
445 
446 static Module *prepareToBuildModule(CompilerInstance &CI,
447                                     StringRef ModuleMapFilename) {
448   if (CI.getLangOpts().CurrentModule.empty()) {
449     CI.getDiagnostics().Report(diag::err_missing_module_name);
450 
451     // FIXME: Eventually, we could consider asking whether there was just
452     // a single module described in the module map, and use that as a
453     // default. Then it would be fairly trivial to just "compile" a module
454     // map with a single module (the common case).
455     return nullptr;
456   }
457 
458   // Dig out the module definition.
459   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
460   Module *M = HS.lookupModule(CI.getLangOpts().CurrentModule,
461                               /*AllowSearch=*/false);
462   if (!M) {
463     CI.getDiagnostics().Report(diag::err_missing_module)
464       << CI.getLangOpts().CurrentModule << ModuleMapFilename;
465 
466     return nullptr;
467   }
468 
469   // Check whether we can build this module at all.
470   if (Preprocessor::checkModuleIsAvailable(CI.getLangOpts(), CI.getTarget(),
471                                            CI.getDiagnostics(), M))
472     return nullptr;
473 
474   // Inform the preprocessor that includes from within the input buffer should
475   // be resolved relative to the build directory of the module map file.
476   CI.getPreprocessor().setMainFileDir(M->Directory);
477 
478   // If the module was inferred from a different module map (via an expanded
479   // umbrella module definition), track that fact.
480   // FIXME: It would be preferable to fill this in as part of processing
481   // the module map, rather than adding it after the fact.
482   StringRef OriginalModuleMapName = CI.getFrontendOpts().OriginalModuleMap;
483   if (!OriginalModuleMapName.empty()) {
484     auto *OriginalModuleMap =
485         CI.getFileManager().getFile(OriginalModuleMapName,
486                                     /*openFile*/ true);
487     if (!OriginalModuleMap) {
488       CI.getDiagnostics().Report(diag::err_module_map_not_found)
489         << OriginalModuleMapName;
490       return nullptr;
491     }
492     if (OriginalModuleMap != CI.getSourceManager().getFileEntryForID(
493                                  CI.getSourceManager().getMainFileID())) {
494       M->IsInferred = true;
495       CI.getPreprocessor().getHeaderSearchInfo().getModuleMap()
496         .setInferredModuleAllowedBy(M, OriginalModuleMap);
497     }
498   }
499 
500   // If we're being run from the command-line, the module build stack will not
501   // have been filled in yet, so complete it now in order to allow us to detect
502   // module cycles.
503   SourceManager &SourceMgr = CI.getSourceManager();
504   if (SourceMgr.getModuleBuildStack().empty())
505     SourceMgr.pushModuleBuildStack(CI.getLangOpts().CurrentModule,
506                                    FullSourceLoc(SourceLocation(), SourceMgr));
507   return M;
508 }
509 
510 /// Compute the input buffer that should be used to build the specified module.
511 static std::unique_ptr<llvm::MemoryBuffer>
512 getInputBufferForModule(CompilerInstance &CI, Module *M) {
513   FileManager &FileMgr = CI.getFileManager();
514 
515   // Collect the set of #includes we need to build the module.
516   SmallString<256> HeaderContents;
517   std::error_code Err = std::error_code();
518   if (Module::Header UmbrellaHeader = M->getUmbrellaHeader())
519     addHeaderInclude(UmbrellaHeader.NameAsWritten, HeaderContents,
520                      CI.getLangOpts(), M->IsExternC);
521   Err = collectModuleHeaderIncludes(
522       CI.getLangOpts(), FileMgr, CI.getDiagnostics(),
523       CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(), M,
524       HeaderContents);
525 
526   if (Err) {
527     CI.getDiagnostics().Report(diag::err_module_cannot_create_includes)
528       << M->getFullModuleName() << Err.message();
529     return nullptr;
530   }
531 
532   return llvm::MemoryBuffer::getMemBufferCopy(
533       HeaderContents, Module::getModuleInputBufferName());
534 }
535 
536 bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
537                                      const FrontendInputFile &RealInput) {
538   FrontendInputFile Input(RealInput);
539   assert(!Instance && "Already processing a source file!");
540   assert(!Input.isEmpty() && "Unexpected empty filename!");
541   setCurrentInput(Input);
542   setCompilerInstance(&CI);
543 
544   bool HasBegunSourceFile = false;
545   bool ReplayASTFile = Input.getKind().getFormat() == InputKind::Precompiled &&
546                        usesPreprocessorOnly();
547   if (!BeginInvocation(CI))
548     goto failure;
549 
550   // If we're replaying the build of an AST file, import it and set up
551   // the initial state from its build.
552   if (ReplayASTFile) {
553     IntrusiveRefCntPtr<DiagnosticsEngine> Diags(&CI.getDiagnostics());
554 
555     // The AST unit populates its own diagnostics engine rather than ours.
556     IntrusiveRefCntPtr<DiagnosticsEngine> ASTDiags(
557         new DiagnosticsEngine(Diags->getDiagnosticIDs(),
558                               &Diags->getDiagnosticOptions()));
559     ASTDiags->setClient(Diags->getClient(), /*OwnsClient*/false);
560 
561     // FIXME: What if the input is a memory buffer?
562     StringRef InputFile = Input.getFile();
563 
564     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
565         InputFile, CI.getPCHContainerReader(), ASTUnit::LoadPreprocessorOnly,
566         ASTDiags, CI.getFileSystemOpts(), CI.getCodeGenOpts().DebugTypeExtRefs);
567     if (!AST)
568       goto failure;
569 
570     // Options relating to how we treat the input (but not what we do with it)
571     // are inherited from the AST unit.
572     CI.getHeaderSearchOpts() = AST->getHeaderSearchOpts();
573     CI.getPreprocessorOpts() = AST->getPreprocessorOpts();
574     CI.getLangOpts() = AST->getLangOpts();
575 
576     // Set the shared objects, these are reset when we finish processing the
577     // file, otherwise the CompilerInstance will happily destroy them.
578     CI.setFileManager(&AST->getFileManager());
579     CI.createSourceManager(CI.getFileManager());
580     CI.getSourceManager().initializeForReplay(AST->getSourceManager());
581 
582     // Preload all the module files loaded transitively by the AST unit. Also
583     // load all module map files that were parsed as part of building the AST
584     // unit.
585     if (auto ASTReader = AST->getASTReader()) {
586       auto &MM = ASTReader->getModuleManager();
587       auto &PrimaryModule = MM.getPrimaryModule();
588 
589       for (serialization::ModuleFile &MF : MM)
590         if (&MF != &PrimaryModule)
591           CI.getFrontendOpts().ModuleFiles.push_back(MF.FileName);
592 
593       ASTReader->visitTopLevelModuleMaps(PrimaryModule,
594                                          [&](const FileEntry *FE) {
595         CI.getFrontendOpts().ModuleMapFiles.push_back(FE->getName());
596       });
597     }
598 
599     // Set up the input file for replay purposes.
600     auto Kind = AST->getInputKind();
601     if (Kind.getFormat() == InputKind::ModuleMap) {
602       Module *ASTModule =
603           AST->getPreprocessor().getHeaderSearchInfo().lookupModule(
604               AST->getLangOpts().CurrentModule, /*AllowSearch*/ false);
605       assert(ASTModule && "module file does not define its own module");
606       Input = FrontendInputFile(ASTModule->PresumedModuleMapFile, Kind);
607     } else {
608       auto &OldSM = AST->getSourceManager();
609       FileID ID = OldSM.getMainFileID();
610       if (auto *File = OldSM.getFileEntryForID(ID))
611         Input = FrontendInputFile(File->getName(), Kind);
612       else
613         Input = FrontendInputFile(OldSM.getBuffer(ID), Kind);
614     }
615     setCurrentInput(Input, std::move(AST));
616   }
617 
618   // AST files follow a very different path, since they share objects via the
619   // AST unit.
620   if (Input.getKind().getFormat() == InputKind::Precompiled) {
621     assert(!usesPreprocessorOnly() && "this case was handled above");
622     assert(hasASTFileSupport() &&
623            "This action does not have AST file support!");
624 
625     IntrusiveRefCntPtr<DiagnosticsEngine> Diags(&CI.getDiagnostics());
626 
627     // FIXME: What if the input is a memory buffer?
628     StringRef InputFile = Input.getFile();
629 
630     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
631         InputFile, CI.getPCHContainerReader(), ASTUnit::LoadEverything, Diags,
632         CI.getFileSystemOpts(), CI.getCodeGenOpts().DebugTypeExtRefs);
633 
634     if (!AST)
635       goto failure;
636 
637     // Inform the diagnostic client we are processing a source file.
638     CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), nullptr);
639     HasBegunSourceFile = true;
640 
641     // Set the shared objects, these are reset when we finish processing the
642     // file, otherwise the CompilerInstance will happily destroy them.
643     CI.setFileManager(&AST->getFileManager());
644     CI.setSourceManager(&AST->getSourceManager());
645     CI.setPreprocessor(AST->getPreprocessorPtr());
646     Preprocessor &PP = CI.getPreprocessor();
647     PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
648                                            PP.getLangOpts());
649     CI.setASTContext(&AST->getASTContext());
650 
651     setCurrentInput(Input, std::move(AST));
652 
653     // Initialize the action.
654     if (!BeginSourceFileAction(CI))
655       goto failure;
656 
657     // Create the AST consumer.
658     CI.setASTConsumer(CreateWrappedASTConsumer(CI, InputFile));
659     if (!CI.hasASTConsumer())
660       goto failure;
661 
662     return true;
663   }
664 
665   // Set up the file and source managers, if needed.
666   if (!CI.hasFileManager()) {
667     if (!CI.createFileManager()) {
668       goto failure;
669     }
670   }
671   if (!CI.hasSourceManager())
672     CI.createSourceManager(CI.getFileManager());
673 
674   // Set up embedding for any specified files. Do this before we load any
675   // source files, including the primary module map for the compilation.
676   for (const auto &F : CI.getFrontendOpts().ModulesEmbedFiles) {
677     if (const auto *FE = CI.getFileManager().getFile(F, /*openFile*/true))
678       CI.getSourceManager().setFileIsTransient(FE);
679     else
680       CI.getDiagnostics().Report(diag::err_modules_embed_file_not_found) << F;
681   }
682   if (CI.getFrontendOpts().ModulesEmbedAllFiles)
683     CI.getSourceManager().setAllFilesAreTransient(true);
684 
685   // IR files bypass the rest of initialization.
686   if (Input.getKind().getLanguage() == InputKind::LLVM_IR) {
687     assert(hasIRSupport() &&
688            "This action does not have IR file support!");
689 
690     // Inform the diagnostic client we are processing a source file.
691     CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), nullptr);
692     HasBegunSourceFile = true;
693 
694     // Initialize the action.
695     if (!BeginSourceFileAction(CI))
696       goto failure;
697 
698     // Initialize the main file entry.
699     if (!CI.InitializeSourceManager(CurrentInput))
700       goto failure;
701 
702     return true;
703   }
704 
705   // If the implicit PCH include is actually a directory, rather than
706   // a single file, search for a suitable PCH file in that directory.
707   if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
708     FileManager &FileMgr = CI.getFileManager();
709     PreprocessorOptions &PPOpts = CI.getPreprocessorOpts();
710     StringRef PCHInclude = PPOpts.ImplicitPCHInclude;
711     std::string SpecificModuleCachePath = CI.getSpecificModuleCachePath();
712     if (const DirectoryEntry *PCHDir = FileMgr.getDirectory(PCHInclude)) {
713       std::error_code EC;
714       SmallString<128> DirNative;
715       llvm::sys::path::native(PCHDir->getName(), DirNative);
716       bool Found = false;
717       llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
718       for (llvm::vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC),
719                                          DirEnd;
720            Dir != DirEnd && !EC; Dir.increment(EC)) {
721         // Check whether this is an acceptable AST file.
722         if (ASTReader::isAcceptableASTFile(
723                 Dir->path(), FileMgr, CI.getPCHContainerReader(),
724                 CI.getLangOpts(), CI.getTargetOpts(), CI.getPreprocessorOpts(),
725                 SpecificModuleCachePath)) {
726           PPOpts.ImplicitPCHInclude = Dir->path();
727           Found = true;
728           break;
729         }
730       }
731 
732       if (!Found) {
733         CI.getDiagnostics().Report(diag::err_fe_no_pch_in_dir) << PCHInclude;
734         goto failure;
735       }
736     }
737   }
738 
739   // Set up the preprocessor if needed. When parsing model files the
740   // preprocessor of the original source is reused.
741   if (!isModelParsingAction())
742     CI.createPreprocessor(getTranslationUnitKind());
743 
744   // Inform the diagnostic client we are processing a source file.
745   CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(),
746                                            &CI.getPreprocessor());
747   HasBegunSourceFile = true;
748 
749   // Initialize the main file entry.
750   if (!CI.InitializeSourceManager(Input))
751     goto failure;
752 
753   // For module map files, we first parse the module map and synthesize a
754   // "<module-includes>" buffer before more conventional processing.
755   if (Input.getKind().getFormat() == InputKind::ModuleMap) {
756     CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleMap);
757 
758     std::string PresumedModuleMapFile;
759     unsigned OffsetToContents;
760     if (loadModuleMapForModuleBuild(CI, Input.isSystem(),
761                                     Input.isPreprocessed(),
762                                     PresumedModuleMapFile, OffsetToContents))
763       goto failure;
764 
765     auto *CurrentModule = prepareToBuildModule(CI, Input.getFile());
766     if (!CurrentModule)
767       goto failure;
768 
769     CurrentModule->PresumedModuleMapFile = PresumedModuleMapFile;
770 
771     if (OffsetToContents)
772       // If the module contents are in the same file, skip to them.
773       CI.getPreprocessor().setSkipMainFilePreamble(OffsetToContents, true);
774     else {
775       // Otherwise, convert the module description to a suitable input buffer.
776       auto Buffer = getInputBufferForModule(CI, CurrentModule);
777       if (!Buffer)
778         goto failure;
779 
780       // Reinitialize the main file entry to refer to the new input.
781       auto Kind = CurrentModule->IsSystem ? SrcMgr::C_System : SrcMgr::C_User;
782       auto &SourceMgr = CI.getSourceManager();
783       auto BufferID = SourceMgr.createFileID(std::move(Buffer), Kind);
784       assert(BufferID.isValid() && "couldn't creaate module buffer ID");
785       SourceMgr.setMainFileID(BufferID);
786     }
787   }
788 
789   // Initialize the action.
790   if (!BeginSourceFileAction(CI))
791     goto failure;
792 
793   // If we were asked to load any module map files, do so now.
794   for (const auto &Filename : CI.getFrontendOpts().ModuleMapFiles) {
795     if (auto *File = CI.getFileManager().getFile(Filename))
796       CI.getPreprocessor().getHeaderSearchInfo().loadModuleMapFile(
797           File, /*IsSystem*/false);
798     else
799       CI.getDiagnostics().Report(diag::err_module_map_not_found) << Filename;
800   }
801 
802   // Add a module declaration scope so that modules from -fmodule-map-file
803   // arguments may shadow modules found implicitly in search paths.
804   CI.getPreprocessor()
805       .getHeaderSearchInfo()
806       .getModuleMap()
807       .finishModuleDeclarationScope();
808 
809   // Create the AST context and consumer unless this is a preprocessor only
810   // action.
811   if (!usesPreprocessorOnly()) {
812     // Parsing a model file should reuse the existing ASTContext.
813     if (!isModelParsingAction())
814       CI.createASTContext();
815 
816     // For preprocessed files, check if the first line specifies the original
817     // source file name with a linemarker.
818     std::string PresumedInputFile = getCurrentFileOrBufferName();
819     if (Input.isPreprocessed())
820       ReadOriginalFileName(CI, PresumedInputFile);
821 
822     std::unique_ptr<ASTConsumer> Consumer =
823         CreateWrappedASTConsumer(CI, PresumedInputFile);
824     if (!Consumer)
825       goto failure;
826 
827     // FIXME: should not overwrite ASTMutationListener when parsing model files?
828     if (!isModelParsingAction())
829       CI.getASTContext().setASTMutationListener(Consumer->GetASTMutationListener());
830 
831     if (!CI.getPreprocessorOpts().ChainedIncludes.empty()) {
832       // Convert headers to PCH and chain them.
833       IntrusiveRefCntPtr<ExternalSemaSource> source, FinalReader;
834       source = createChainedIncludesSource(CI, FinalReader);
835       if (!source)
836         goto failure;
837       CI.setModuleManager(static_cast<ASTReader *>(FinalReader.get()));
838       CI.getASTContext().setExternalSource(source);
839     } else if (CI.getLangOpts().Modules ||
840                !CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
841       // Use PCM or PCH.
842       assert(hasPCHSupport() && "This action does not have PCH support!");
843       ASTDeserializationListener *DeserialListener =
844           Consumer->GetASTDeserializationListener();
845       bool DeleteDeserialListener = false;
846       if (CI.getPreprocessorOpts().DumpDeserializedPCHDecls) {
847         DeserialListener = new DeserializedDeclsDumper(DeserialListener,
848                                                        DeleteDeserialListener);
849         DeleteDeserialListener = true;
850       }
851       if (!CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn.empty()) {
852         DeserialListener = new DeserializedDeclsChecker(
853             CI.getASTContext(),
854             CI.getPreprocessorOpts().DeserializedPCHDeclsToErrorOn,
855             DeserialListener, DeleteDeserialListener);
856         DeleteDeserialListener = true;
857       }
858       if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
859         CI.createPCHExternalASTSource(
860             CI.getPreprocessorOpts().ImplicitPCHInclude,
861             CI.getPreprocessorOpts().DisablePCHValidation,
862           CI.getPreprocessorOpts().AllowPCHWithCompilerErrors, DeserialListener,
863             DeleteDeserialListener);
864         if (!CI.getASTContext().getExternalSource())
865           goto failure;
866       }
867       // If modules are enabled, create the module manager before creating
868       // any builtins, so that all declarations know that they might be
869       // extended by an external source.
870       if (CI.getLangOpts().Modules || !CI.hasASTContext() ||
871           !CI.getASTContext().getExternalSource()) {
872         CI.createModuleManager();
873         CI.getModuleManager()->setDeserializationListener(DeserialListener,
874                                                         DeleteDeserialListener);
875       }
876     }
877 
878     CI.setASTConsumer(std::move(Consumer));
879     if (!CI.hasASTConsumer())
880       goto failure;
881   }
882 
883   // Initialize built-in info as long as we aren't using an external AST
884   // source.
885   if (CI.getLangOpts().Modules || !CI.hasASTContext() ||
886       !CI.getASTContext().getExternalSource()) {
887     Preprocessor &PP = CI.getPreprocessor();
888     PP.getBuiltinInfo().initializeBuiltins(PP.getIdentifierTable(),
889                                            PP.getLangOpts());
890   } else {
891     // FIXME: If this is a problem, recover from it by creating a multiplex
892     // source.
893     assert((!CI.getLangOpts().Modules || CI.getModuleManager()) &&
894            "modules enabled but created an external source that "
895            "doesn't support modules");
896   }
897 
898   // If we were asked to load any module files, do so now.
899   for (const auto &ModuleFile : CI.getFrontendOpts().ModuleFiles)
900     if (!CI.loadModuleFile(ModuleFile))
901       goto failure;
902 
903   // If there is a layout overrides file, attach an external AST source that
904   // provides the layouts from that file.
905   if (!CI.getFrontendOpts().OverrideRecordLayoutsFile.empty() &&
906       CI.hasASTContext() && !CI.getASTContext().getExternalSource()) {
907     IntrusiveRefCntPtr<ExternalASTSource>
908       Override(new LayoutOverrideSource(
909                      CI.getFrontendOpts().OverrideRecordLayoutsFile));
910     CI.getASTContext().setExternalSource(Override);
911   }
912 
913   return true;
914 
915   // If we failed, reset state since the client will not end up calling the
916   // matching EndSourceFile().
917 failure:
918   if (HasBegunSourceFile)
919     CI.getDiagnosticClient().EndSourceFile();
920   CI.clearOutputFiles(/*EraseFiles=*/true);
921   CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
922   setCurrentInput(FrontendInputFile());
923   setCompilerInstance(nullptr);
924   return false;
925 }
926 
927 llvm::Error FrontendAction::Execute() {
928   CompilerInstance &CI = getCompilerInstance();
929 
930   if (CI.hasFrontendTimer()) {
931     llvm::TimeRegion Timer(CI.getFrontendTimer());
932     ExecuteAction();
933   }
934   else ExecuteAction();
935 
936   // If we are supposed to rebuild the global module index, do so now unless
937   // there were any module-build failures.
938   if (CI.shouldBuildGlobalModuleIndex() && CI.hasFileManager() &&
939       CI.hasPreprocessor()) {
940     StringRef Cache =
941         CI.getPreprocessor().getHeaderSearchInfo().getModuleCachePath();
942     if (!Cache.empty()) {
943       if (llvm::Error Err = GlobalModuleIndex::writeIndex(
944               CI.getFileManager(), CI.getPCHContainerReader(), Cache)) {
945         // FIXME this drops the error on the floor, but
946         // Index/pch-from-libclang.c seems to rely on dropping at least some of
947         // the error conditions!
948         consumeError(std::move(Err));
949       }
950     }
951   }
952 
953   return llvm::Error::success();
954 }
955 
956 void FrontendAction::EndSourceFile() {
957   CompilerInstance &CI = getCompilerInstance();
958 
959   // Inform the diagnostic client we are done with this source file.
960   CI.getDiagnosticClient().EndSourceFile();
961 
962   // Inform the preprocessor we are done.
963   if (CI.hasPreprocessor())
964     CI.getPreprocessor().EndSourceFile();
965 
966   // Finalize the action.
967   EndSourceFileAction();
968 
969   // Sema references the ast consumer, so reset sema first.
970   //
971   // FIXME: There is more per-file stuff we could just drop here?
972   bool DisableFree = CI.getFrontendOpts().DisableFree;
973   if (DisableFree) {
974     CI.resetAndLeakSema();
975     CI.resetAndLeakASTContext();
976     llvm::BuryPointer(CI.takeASTConsumer().get());
977   } else {
978     CI.setSema(nullptr);
979     CI.setASTContext(nullptr);
980     CI.setASTConsumer(nullptr);
981   }
982 
983   if (CI.getFrontendOpts().ShowStats) {
984     llvm::errs() << "\nSTATISTICS FOR '" << getCurrentFile() << "':\n";
985     CI.getPreprocessor().PrintStats();
986     CI.getPreprocessor().getIdentifierTable().PrintStats();
987     CI.getPreprocessor().getHeaderSearchInfo().PrintStats();
988     CI.getSourceManager().PrintStats();
989     llvm::errs() << "\n";
990   }
991 
992   // Cleanup the output streams, and erase the output files if instructed by the
993   // FrontendAction.
994   CI.clearOutputFiles(/*EraseFiles=*/shouldEraseOutputFiles());
995 
996   if (isCurrentFileAST()) {
997     if (DisableFree) {
998       CI.resetAndLeakPreprocessor();
999       CI.resetAndLeakSourceManager();
1000       CI.resetAndLeakFileManager();
1001       llvm::BuryPointer(std::move(CurrentASTUnit));
1002     } else {
1003       CI.setPreprocessor(nullptr);
1004       CI.setSourceManager(nullptr);
1005       CI.setFileManager(nullptr);
1006     }
1007   }
1008 
1009   setCompilerInstance(nullptr);
1010   setCurrentInput(FrontendInputFile());
1011   CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
1012 }
1013 
1014 bool FrontendAction::shouldEraseOutputFiles() {
1015   return getCompilerInstance().getDiagnostics().hasErrorOccurred();
1016 }
1017 
1018 //===----------------------------------------------------------------------===//
1019 // Utility Actions
1020 //===----------------------------------------------------------------------===//
1021 
1022 void ASTFrontendAction::ExecuteAction() {
1023   CompilerInstance &CI = getCompilerInstance();
1024   if (!CI.hasPreprocessor())
1025     return;
1026 
1027   // FIXME: Move the truncation aspect of this into Sema, we delayed this till
1028   // here so the source manager would be initialized.
1029   if (hasCodeCompletionSupport() &&
1030       !CI.getFrontendOpts().CodeCompletionAt.FileName.empty())
1031     CI.createCodeCompletionConsumer();
1032 
1033   // Use a code completion consumer?
1034   CodeCompleteConsumer *CompletionConsumer = nullptr;
1035   if (CI.hasCodeCompletionConsumer())
1036     CompletionConsumer = &CI.getCodeCompletionConsumer();
1037 
1038   if (!CI.hasSema())
1039     CI.createSema(getTranslationUnitKind(), CompletionConsumer);
1040 
1041   ParseAST(CI.getSema(), CI.getFrontendOpts().ShowStats,
1042            CI.getFrontendOpts().SkipFunctionBodies);
1043 }
1044 
1045 void PluginASTAction::anchor() { }
1046 
1047 std::unique_ptr<ASTConsumer>
1048 PreprocessorFrontendAction::CreateASTConsumer(CompilerInstance &CI,
1049                                               StringRef InFile) {
1050   llvm_unreachable("Invalid CreateASTConsumer on preprocessor action!");
1051 }
1052 
1053 bool WrapperFrontendAction::PrepareToExecuteAction(CompilerInstance &CI) {
1054   return WrappedAction->PrepareToExecuteAction(CI);
1055 }
1056 std::unique_ptr<ASTConsumer>
1057 WrapperFrontendAction::CreateASTConsumer(CompilerInstance &CI,
1058                                          StringRef InFile) {
1059   return WrappedAction->CreateASTConsumer(CI, InFile);
1060 }
1061 bool WrapperFrontendAction::BeginInvocation(CompilerInstance &CI) {
1062   return WrappedAction->BeginInvocation(CI);
1063 }
1064 bool WrapperFrontendAction::BeginSourceFileAction(CompilerInstance &CI) {
1065   WrappedAction->setCurrentInput(getCurrentInput());
1066   WrappedAction->setCompilerInstance(&CI);
1067   auto Ret = WrappedAction->BeginSourceFileAction(CI);
1068   // BeginSourceFileAction may change CurrentInput, e.g. during module builds.
1069   setCurrentInput(WrappedAction->getCurrentInput());
1070   return Ret;
1071 }
1072 void WrapperFrontendAction::ExecuteAction() {
1073   WrappedAction->ExecuteAction();
1074 }
1075 void WrapperFrontendAction::EndSourceFileAction() {
1076   WrappedAction->EndSourceFileAction();
1077 }
1078 
1079 bool WrapperFrontendAction::usesPreprocessorOnly() const {
1080   return WrappedAction->usesPreprocessorOnly();
1081 }
1082 TranslationUnitKind WrapperFrontendAction::getTranslationUnitKind() {
1083   return WrappedAction->getTranslationUnitKind();
1084 }
1085 bool WrapperFrontendAction::hasPCHSupport() const {
1086   return WrappedAction->hasPCHSupport();
1087 }
1088 bool WrapperFrontendAction::hasASTFileSupport() const {
1089   return WrappedAction->hasASTFileSupport();
1090 }
1091 bool WrapperFrontendAction::hasIRSupport() const {
1092   return WrappedAction->hasIRSupport();
1093 }
1094 bool WrapperFrontendAction::hasCodeCompletionSupport() const {
1095   return WrappedAction->hasCodeCompletionSupport();
1096 }
1097 
1098 WrapperFrontendAction::WrapperFrontendAction(
1099     std::unique_ptr<FrontendAction> WrappedAction)
1100   : WrappedAction(std::move(WrappedAction)) {}
1101 
1102