xref: /llvm-project/clang/lib/Frontend/CompilerInstance.cpp (revision 97eec24b0bc245fc96ac9615899c3d15a6bc8b3e)
1 //===--- CompilerInstance.cpp ---------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "clang/Frontend/CompilerInstance.h"
11 #include "clang/Sema/Sema.h"
12 #include "clang/AST/ASTConsumer.h"
13 #include "clang/AST/ASTContext.h"
14 #include "clang/Basic/Diagnostic.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/Basic/Version.h"
19 #include "clang/Lex/HeaderSearch.h"
20 #include "clang/Lex/Preprocessor.h"
21 #include "clang/Lex/PTHManager.h"
22 #include "clang/Frontend/ChainedDiagnosticClient.h"
23 #include "clang/Frontend/FrontendAction.h"
24 #include "clang/Frontend/FrontendActions.h"
25 #include "clang/Frontend/FrontendDiagnostic.h"
26 #include "clang/Frontend/LogDiagnosticPrinter.h"
27 #include "clang/Frontend/TextDiagnosticPrinter.h"
28 #include "clang/Frontend/VerifyDiagnosticsClient.h"
29 #include "clang/Frontend/Utils.h"
30 #include "clang/Serialization/ASTReader.h"
31 #include "clang/Sema/CodeCompleteConsumer.h"
32 #include "llvm/Support/FileSystem.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include "llvm/ADT/Statistic.h"
36 #include "llvm/Support/Timer.h"
37 #include "llvm/Support/Host.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Support/Program.h"
40 #include "llvm/Support/Signals.h"
41 #include "llvm/Support/system_error.h"
42 #include "llvm/Config/config.h"
43 using namespace clang;
44 
45 CompilerInstance::CompilerInstance()
46   : Invocation(new CompilerInvocation()), ModuleManager(0) {
47 }
48 
49 CompilerInstance::~CompilerInstance() {
50 }
51 
52 void CompilerInstance::setInvocation(CompilerInvocation *Value) {
53   Invocation = Value;
54 }
55 
56 void CompilerInstance::setDiagnostics(Diagnostic *Value) {
57   Diagnostics = Value;
58 }
59 
60 void CompilerInstance::setTarget(TargetInfo *Value) {
61   Target = Value;
62 }
63 
64 void CompilerInstance::setFileManager(FileManager *Value) {
65   FileMgr = Value;
66 }
67 
68 void CompilerInstance::setSourceManager(SourceManager *Value) {
69   SourceMgr = Value;
70 }
71 
72 void CompilerInstance::setPreprocessor(Preprocessor *Value) { PP = Value; }
73 
74 void CompilerInstance::setASTContext(ASTContext *Value) { Context = Value; }
75 
76 void CompilerInstance::setSema(Sema *S) {
77   TheSema.reset(S);
78 }
79 
80 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
81   Consumer.reset(Value);
82 }
83 
84 void CompilerInstance::setCodeCompletionConsumer(CodeCompleteConsumer *Value) {
85   CompletionConsumer.reset(Value);
86 }
87 
88 // Diagnostics
89 static void SetUpBuildDumpLog(const DiagnosticOptions &DiagOpts,
90                               unsigned argc, const char* const *argv,
91                               Diagnostic &Diags) {
92   std::string ErrorInfo;
93   llvm::OwningPtr<raw_ostream> OS(
94     new llvm::raw_fd_ostream(DiagOpts.DumpBuildInformation.c_str(), ErrorInfo));
95   if (!ErrorInfo.empty()) {
96     Diags.Report(diag::err_fe_unable_to_open_logfile)
97                  << DiagOpts.DumpBuildInformation << ErrorInfo;
98     return;
99   }
100 
101   (*OS) << "clang -cc1 command line arguments: ";
102   for (unsigned i = 0; i != argc; ++i)
103     (*OS) << argv[i] << ' ';
104   (*OS) << '\n';
105 
106   // Chain in a diagnostic client which will log the diagnostics.
107   DiagnosticClient *Logger =
108     new TextDiagnosticPrinter(*OS.take(), DiagOpts, /*OwnsOutputStream=*/true);
109   Diags.setClient(new ChainedDiagnosticClient(Diags.takeClient(), Logger));
110 }
111 
112 static void SetUpDiagnosticLog(const DiagnosticOptions &DiagOpts,
113                                const CodeGenOptions *CodeGenOpts,
114                                Diagnostic &Diags) {
115   std::string ErrorInfo;
116   bool OwnsStream = false;
117   raw_ostream *OS = &llvm::errs();
118   if (DiagOpts.DiagnosticLogFile != "-") {
119     // Create the output stream.
120     llvm::raw_fd_ostream *FileOS(
121       new llvm::raw_fd_ostream(DiagOpts.DiagnosticLogFile.c_str(),
122                                ErrorInfo, llvm::raw_fd_ostream::F_Append));
123     if (!ErrorInfo.empty()) {
124       Diags.Report(diag::warn_fe_cc_log_diagnostics_failure)
125         << DiagOpts.DumpBuildInformation << ErrorInfo;
126     } else {
127       FileOS->SetUnbuffered();
128       FileOS->SetUseAtomicWrites(true);
129       OS = FileOS;
130       OwnsStream = true;
131     }
132   }
133 
134   // Chain in the diagnostic client which will log the diagnostics.
135   LogDiagnosticPrinter *Logger = new LogDiagnosticPrinter(*OS, DiagOpts,
136                                                           OwnsStream);
137   if (CodeGenOpts)
138     Logger->setDwarfDebugFlags(CodeGenOpts->DwarfDebugFlags);
139   Diags.setClient(new ChainedDiagnosticClient(Diags.takeClient(), Logger));
140 }
141 
142 void CompilerInstance::createDiagnostics(int Argc, const char* const *Argv,
143                                          DiagnosticClient *Client,
144                                          bool ShouldOwnClient) {
145   Diagnostics = createDiagnostics(getDiagnosticOpts(), Argc, Argv, Client,
146                                   ShouldOwnClient, &getCodeGenOpts());
147 }
148 
149 llvm::IntrusiveRefCntPtr<Diagnostic>
150 CompilerInstance::createDiagnostics(const DiagnosticOptions &Opts,
151                                     int Argc, const char* const *Argv,
152                                     DiagnosticClient *Client,
153                                     bool ShouldOwnClient,
154                                     const CodeGenOptions *CodeGenOpts) {
155   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
156   llvm::IntrusiveRefCntPtr<Diagnostic> Diags(new Diagnostic(DiagID));
157 
158   // Create the diagnostic client for reporting errors or for
159   // implementing -verify.
160   if (Client)
161     Diags->setClient(Client, ShouldOwnClient);
162   else
163     Diags->setClient(new TextDiagnosticPrinter(llvm::errs(), Opts));
164 
165   // Chain in -verify checker, if requested.
166   if (Opts.VerifyDiagnostics)
167     Diags->setClient(new VerifyDiagnosticsClient(*Diags));
168 
169   // Chain in -diagnostic-log-file dumper, if requested.
170   if (!Opts.DiagnosticLogFile.empty())
171     SetUpDiagnosticLog(Opts, CodeGenOpts, *Diags);
172 
173   if (!Opts.DumpBuildInformation.empty())
174     SetUpBuildDumpLog(Opts, Argc, Argv, *Diags);
175 
176   // Configure our handling of diagnostics.
177   ProcessWarningOptions(*Diags, Opts);
178 
179   return Diags;
180 }
181 
182 // File Manager
183 
184 void CompilerInstance::createFileManager() {
185   FileMgr = new FileManager(getFileSystemOpts());
186 }
187 
188 // Source Manager
189 
190 void CompilerInstance::createSourceManager(FileManager &FileMgr) {
191   SourceMgr = new SourceManager(getDiagnostics(), FileMgr);
192 }
193 
194 // Preprocessor
195 
196 void CompilerInstance::createPreprocessor() {
197   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
198 
199   // Create a PTH manager if we are using some form of a token cache.
200   PTHManager *PTHMgr = 0;
201   if (!PPOpts.TokenCache.empty())
202     PTHMgr = PTHManager::Create(PPOpts.TokenCache, getDiagnostics());
203 
204   // Create the Preprocessor.
205   HeaderSearch *HeaderInfo = new HeaderSearch(getFileManager());
206   PP = new Preprocessor(getDiagnostics(), getLangOpts(), &getTarget(),
207                         getSourceManager(), *HeaderInfo, *this, PTHMgr,
208                         /*OwnsHeaderSearch=*/true);
209 
210   // Note that this is different then passing PTHMgr to Preprocessor's ctor.
211   // That argument is used as the IdentifierInfoLookup argument to
212   // IdentifierTable's ctor.
213   if (PTHMgr) {
214     PTHMgr->setPreprocessor(&*PP);
215     PP->setPTHManager(PTHMgr);
216   }
217 
218   if (PPOpts.DetailedRecord)
219     PP->createPreprocessingRecord(
220                                   PPOpts.DetailedRecordIncludesNestedMacroExpansions);
221 
222   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
223 
224   // Set up the module path, including the hash for the
225   // module-creation options.
226   llvm::SmallString<256> SpecificModuleCache(
227                            getHeaderSearchOpts().ModuleCachePath);
228   if (!getHeaderSearchOpts().DisableModuleHash)
229     llvm::sys::path::append(SpecificModuleCache,
230                             getInvocation().getModuleHash());
231   PP->getHeaderSearchInfo().configureModules(SpecificModuleCache,
232     getPreprocessorOpts().ModuleBuildPath.empty()
233       ? std::string()
234       : getPreprocessorOpts().ModuleBuildPath.back());
235 
236   // Handle generating dependencies, if requested.
237   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
238   if (!DepOpts.OutputFile.empty())
239     AttachDependencyFileGen(*PP, DepOpts);
240 
241   // Handle generating header include information, if requested.
242   if (DepOpts.ShowHeaderIncludes)
243     AttachHeaderIncludeGen(*PP);
244   if (!DepOpts.HeaderIncludeOutputFile.empty()) {
245     StringRef OutputPath = DepOpts.HeaderIncludeOutputFile;
246     if (OutputPath == "-")
247       OutputPath = "";
248     AttachHeaderIncludeGen(*PP, /*ShowAllHeaders=*/true, OutputPath,
249                            /*ShowDepth=*/false);
250   }
251 }
252 
253 // ASTContext
254 
255 void CompilerInstance::createASTContext() {
256   Preprocessor &PP = getPreprocessor();
257   Context = new ASTContext(getLangOpts(), PP.getSourceManager(),
258                            &getTarget(), PP.getIdentifierTable(),
259                            PP.getSelectorTable(), PP.getBuiltinInfo(),
260                            /*size_reserve=*/ 0);
261 }
262 
263 // ExternalASTSource
264 
265 void CompilerInstance::createPCHExternalASTSource(StringRef Path,
266                                                   bool DisablePCHValidation,
267                                                   bool DisableStatCache,
268                                                  void *DeserializationListener){
269   llvm::OwningPtr<ExternalASTSource> Source;
270   bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
271   Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
272                                           DisablePCHValidation,
273                                           DisableStatCache,
274                                           getPreprocessor(), getASTContext(),
275                                           DeserializationListener,
276                                           Preamble));
277   ModuleManager = static_cast<ASTReader*>(Source.get());
278   getASTContext().setExternalSource(Source);
279 }
280 
281 ExternalASTSource *
282 CompilerInstance::createPCHExternalASTSource(StringRef Path,
283                                              const std::string &Sysroot,
284                                              bool DisablePCHValidation,
285                                              bool DisableStatCache,
286                                              Preprocessor &PP,
287                                              ASTContext &Context,
288                                              void *DeserializationListener,
289                                              bool Preamble) {
290   llvm::OwningPtr<ASTReader> Reader;
291   Reader.reset(new ASTReader(PP, Context,
292                              Sysroot.empty() ? "" : Sysroot.c_str(),
293                              DisablePCHValidation, DisableStatCache));
294 
295   Reader->setDeserializationListener(
296             static_cast<ASTDeserializationListener *>(DeserializationListener));
297   switch (Reader->ReadAST(Path,
298                           Preamble ? serialization::MK_Preamble
299                                    : serialization::MK_PCH)) {
300   case ASTReader::Success:
301     // Set the predefines buffer as suggested by the PCH reader. Typically, the
302     // predefines buffer will be empty.
303     PP.setPredefines(Reader->getSuggestedPredefines());
304     return Reader.take();
305 
306   case ASTReader::Failure:
307     // Unrecoverable failure: don't even try to process the input file.
308     break;
309 
310   case ASTReader::IgnorePCH:
311     // No suitable PCH file could be found. Return an error.
312     break;
313   }
314 
315   return 0;
316 }
317 
318 // Code Completion
319 
320 static bool EnableCodeCompletion(Preprocessor &PP,
321                                  const std::string &Filename,
322                                  unsigned Line,
323                                  unsigned Column) {
324   // Tell the source manager to chop off the given file at a specific
325   // line and column.
326   const FileEntry *Entry = PP.getFileManager().getFile(Filename);
327   if (!Entry) {
328     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
329       << Filename;
330     return true;
331   }
332 
333   // Truncate the named file at the given line/column.
334   PP.SetCodeCompletionPoint(Entry, Line, Column);
335   return false;
336 }
337 
338 void CompilerInstance::createCodeCompletionConsumer() {
339   const ParsedSourceLocation &Loc = getFrontendOpts().CodeCompletionAt;
340   if (!CompletionConsumer) {
341     CompletionConsumer.reset(
342       createCodeCompletionConsumer(getPreprocessor(),
343                                    Loc.FileName, Loc.Line, Loc.Column,
344                                    getFrontendOpts().ShowMacrosInCodeCompletion,
345                              getFrontendOpts().ShowCodePatternsInCodeCompletion,
346                            getFrontendOpts().ShowGlobalSymbolsInCodeCompletion,
347                                    llvm::outs()));
348     if (!CompletionConsumer)
349       return;
350   } else if (EnableCodeCompletion(getPreprocessor(), Loc.FileName,
351                                   Loc.Line, Loc.Column)) {
352     CompletionConsumer.reset();
353     return;
354   }
355 
356   if (CompletionConsumer->isOutputBinary() &&
357       llvm::sys::Program::ChangeStdoutToBinary()) {
358     getPreprocessor().getDiagnostics().Report(diag::err_fe_stdout_binary);
359     CompletionConsumer.reset();
360   }
361 }
362 
363 void CompilerInstance::createFrontendTimer() {
364   FrontendTimer.reset(new llvm::Timer("Clang front-end timer"));
365 }
366 
367 CodeCompleteConsumer *
368 CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
369                                                const std::string &Filename,
370                                                unsigned Line,
371                                                unsigned Column,
372                                                bool ShowMacros,
373                                                bool ShowCodePatterns,
374                                                bool ShowGlobals,
375                                                raw_ostream &OS) {
376   if (EnableCodeCompletion(PP, Filename, Line, Column))
377     return 0;
378 
379   // Set up the creation routine for code-completion.
380   return new PrintingCodeCompleteConsumer(ShowMacros, ShowCodePatterns,
381                                           ShowGlobals, OS);
382 }
383 
384 void CompilerInstance::createSema(TranslationUnitKind TUKind,
385                                   CodeCompleteConsumer *CompletionConsumer) {
386   TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
387                          TUKind, CompletionConsumer));
388 }
389 
390 // Output Files
391 
392 void CompilerInstance::addOutputFile(const OutputFile &OutFile) {
393   assert(OutFile.OS && "Attempt to add empty stream to output list!");
394   OutputFiles.push_back(OutFile);
395 }
396 
397 void CompilerInstance::clearOutputFiles(bool EraseFiles) {
398   for (std::list<OutputFile>::iterator
399          it = OutputFiles.begin(), ie = OutputFiles.end(); it != ie; ++it) {
400     delete it->OS;
401     if (!it->TempFilename.empty()) {
402       if (EraseFiles) {
403         bool existed;
404         llvm::sys::fs::remove(it->TempFilename, existed);
405       } else {
406         llvm::SmallString<128> NewOutFile(it->Filename);
407 
408         // If '-working-directory' was passed, the output filename should be
409         // relative to that.
410         FileMgr->FixupRelativePath(NewOutFile);
411         if (llvm::error_code ec = llvm::sys::fs::rename(it->TempFilename,
412                                                         NewOutFile.str())) {
413           getDiagnostics().Report(diag::err_fe_unable_to_rename_temp)
414             << it->TempFilename << it->Filename << ec.message();
415 
416           bool existed;
417           llvm::sys::fs::remove(it->TempFilename, existed);
418         }
419       }
420     } else if (!it->Filename.empty() && EraseFiles)
421       llvm::sys::Path(it->Filename).eraseFromDisk();
422 
423   }
424   OutputFiles.clear();
425 }
426 
427 llvm::raw_fd_ostream *
428 CompilerInstance::createDefaultOutputFile(bool Binary,
429                                           StringRef InFile,
430                                           StringRef Extension) {
431   return createOutputFile(getFrontendOpts().OutputFile, Binary,
432                           /*RemoveFileOnSignal=*/true, InFile, Extension);
433 }
434 
435 llvm::raw_fd_ostream *
436 CompilerInstance::createOutputFile(StringRef OutputPath,
437                                    bool Binary, bool RemoveFileOnSignal,
438                                    StringRef InFile,
439                                    StringRef Extension,
440                                    bool UseTemporary) {
441   std::string Error, OutputPathName, TempPathName;
442   llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
443                                               RemoveFileOnSignal,
444                                               InFile, Extension,
445                                               UseTemporary,
446                                               &OutputPathName,
447                                               &TempPathName);
448   if (!OS) {
449     getDiagnostics().Report(diag::err_fe_unable_to_open_output)
450       << OutputPath << Error;
451     return 0;
452   }
453 
454   // Add the output file -- but don't try to remove "-", since this means we are
455   // using stdin.
456   addOutputFile(OutputFile((OutputPathName != "-") ? OutputPathName : "",
457                 TempPathName, OS));
458 
459   return OS;
460 }
461 
462 llvm::raw_fd_ostream *
463 CompilerInstance::createOutputFile(StringRef OutputPath,
464                                    std::string &Error,
465                                    bool Binary,
466                                    bool RemoveFileOnSignal,
467                                    StringRef InFile,
468                                    StringRef Extension,
469                                    bool UseTemporary,
470                                    std::string *ResultPathName,
471                                    std::string *TempPathName) {
472   std::string OutFile, TempFile;
473   if (!OutputPath.empty()) {
474     OutFile = OutputPath;
475   } else if (InFile == "-") {
476     OutFile = "-";
477   } else if (!Extension.empty()) {
478     llvm::sys::Path Path(InFile);
479     Path.eraseSuffix();
480     Path.appendSuffix(Extension);
481     OutFile = Path.str();
482   } else {
483     OutFile = "-";
484   }
485 
486   llvm::OwningPtr<llvm::raw_fd_ostream> OS;
487   std::string OSFile;
488 
489   if (UseTemporary && OutFile != "-") {
490     llvm::sys::Path OutPath(OutFile);
491     // Only create the temporary if we can actually write to OutPath, otherwise
492     // we want to fail early.
493     bool Exists;
494     if ((llvm::sys::fs::exists(OutPath.str(), Exists) || !Exists) ||
495         (OutPath.isRegularFile() && OutPath.canWrite())) {
496       // Create a temporary file.
497       llvm::SmallString<128> TempPath;
498       TempPath = OutFile;
499       TempPath += "-%%%%%%%%";
500       int fd;
501       if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
502                                /*makeAbsolute=*/false) == llvm::errc::success) {
503         OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
504         OSFile = TempFile = TempPath.str();
505       }
506     }
507   }
508 
509   if (!OS) {
510     OSFile = OutFile;
511     OS.reset(
512       new llvm::raw_fd_ostream(OSFile.c_str(), Error,
513                                (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
514     if (!Error.empty())
515       return 0;
516   }
517 
518   // Make sure the out stream file gets removed if we crash.
519   if (RemoveFileOnSignal)
520     llvm::sys::RemoveFileOnSignal(llvm::sys::Path(OSFile));
521 
522   if (ResultPathName)
523     *ResultPathName = OutFile;
524   if (TempPathName)
525     *TempPathName = TempFile;
526 
527   return OS.take();
528 }
529 
530 // Initialization Utilities
531 
532 bool CompilerInstance::InitializeSourceManager(StringRef InputFile) {
533   return InitializeSourceManager(InputFile, getDiagnostics(), getFileManager(),
534                                  getSourceManager(), getFrontendOpts());
535 }
536 
537 bool CompilerInstance::InitializeSourceManager(StringRef InputFile,
538                                                Diagnostic &Diags,
539                                                FileManager &FileMgr,
540                                                SourceManager &SourceMgr,
541                                                const FrontendOptions &Opts) {
542   // Figure out where to get and map in the main file, unless it's already
543   // been created (e.g., by a precompiled preamble).
544   if (!SourceMgr.getMainFileID().isInvalid()) {
545     // Do nothing: the main file has already been set.
546   } else if (InputFile != "-") {
547     const FileEntry *File = FileMgr.getFile(InputFile);
548     if (!File) {
549       Diags.Report(diag::err_fe_error_reading) << InputFile;
550       return false;
551     }
552     SourceMgr.createMainFileID(File);
553   } else {
554     llvm::OwningPtr<llvm::MemoryBuffer> SB;
555     if (llvm::MemoryBuffer::getSTDIN(SB)) {
556       // FIXME: Give ec.message() in this diag.
557       Diags.Report(diag::err_fe_error_reading_stdin);
558       return false;
559     }
560     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
561                                                    SB->getBufferSize(), 0);
562     SourceMgr.createMainFileID(File);
563     SourceMgr.overrideFileContents(File, SB.take());
564   }
565 
566   assert(!SourceMgr.getMainFileID().isInvalid() &&
567          "Couldn't establish MainFileID!");
568   return true;
569 }
570 
571 // High-Level Operations
572 
573 bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
574   assert(hasDiagnostics() && "Diagnostics engine is not initialized!");
575   assert(!getFrontendOpts().ShowHelp && "Client must handle '-help'!");
576   assert(!getFrontendOpts().ShowVersion && "Client must handle '-version'!");
577 
578   // FIXME: Take this as an argument, once all the APIs we used have moved to
579   // taking it as an input instead of hard-coding llvm::errs.
580   raw_ostream &OS = llvm::errs();
581 
582   // Create the target instance.
583   setTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), getTargetOpts()));
584   if (!hasTarget())
585     return false;
586 
587   // Inform the target of the language options.
588   //
589   // FIXME: We shouldn't need to do this, the target should be immutable once
590   // created. This complexity should be lifted elsewhere.
591   getTarget().setForcedLangOptions(getLangOpts());
592 
593   // Validate/process some options.
594   if (getHeaderSearchOpts().Verbose)
595     OS << "clang -cc1 version " CLANG_VERSION_STRING
596        << " based upon " << PACKAGE_STRING
597        << " hosted on " << llvm::sys::getHostTriple() << "\n";
598 
599   if (getFrontendOpts().ShowTimers)
600     createFrontendTimer();
601 
602   if (getFrontendOpts().ShowStats)
603     llvm::EnableStatistics();
604 
605   for (unsigned i = 0, e = getFrontendOpts().Inputs.size(); i != e; ++i) {
606     const std::string &InFile = getFrontendOpts().Inputs[i].second;
607 
608     // Reset the ID tables if we are reusing the SourceManager.
609     if (hasSourceManager())
610       getSourceManager().clearIDTables();
611 
612     if (Act.BeginSourceFile(*this, InFile, getFrontendOpts().Inputs[i].first)) {
613       Act.Execute();
614       Act.EndSourceFile();
615     }
616   }
617 
618   if (getDiagnosticOpts().ShowCarets) {
619     // We can have multiple diagnostics sharing one diagnostic client.
620     // Get the total number of warnings/errors from the client.
621     unsigned NumWarnings = getDiagnostics().getClient()->getNumWarnings();
622     unsigned NumErrors = getDiagnostics().getClient()->getNumErrors();
623 
624     if (NumWarnings)
625       OS << NumWarnings << " warning" << (NumWarnings == 1 ? "" : "s");
626     if (NumWarnings && NumErrors)
627       OS << " and ";
628     if (NumErrors)
629       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
630     if (NumWarnings || NumErrors)
631       OS << " generated.\n";
632   }
633 
634   if (getFrontendOpts().ShowStats && hasFileManager()) {
635     getFileManager().PrintStats();
636     OS << "\n";
637   }
638 
639   return !getDiagnostics().getClient()->getNumErrors();
640 }
641 
642 /// \brief Determine the appropriate source input kind based on language
643 /// options.
644 static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
645   if (LangOpts.OpenCL)
646     return IK_OpenCL;
647   if (LangOpts.CUDA)
648     return IK_CUDA;
649   if (LangOpts.ObjC1)
650     return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
651   return LangOpts.CPlusPlus? IK_CXX : IK_C;
652 }
653 
654 /// \brief Compile a module file for the given module name with the given
655 /// umbrella header, using the options provided by the importing compiler
656 /// instance.
657 static void compileModule(CompilerInstance &ImportingInstance,
658                           StringRef ModuleName,
659                           StringRef ModuleFileName,
660                           StringRef UmbrellaHeader) {
661   // Construct a compiler invocation for creating this module.
662   llvm::IntrusiveRefCntPtr<CompilerInvocation> Invocation
663     (new CompilerInvocation(ImportingInstance.getInvocation()));
664 
665   // For any options that aren't intended to affect how a module is built,
666   // reset them to their default values.
667   Invocation->getLangOpts().resetNonModularOptions();
668   Invocation->getPreprocessorOpts().resetNonModularOptions();
669 
670   // Note that this module is part of the module build path, so that we
671   // can detect cycles in the module graph.
672   Invocation->getPreprocessorOpts().ModuleBuildPath.push_back(ModuleName);
673 
674   // Set up the inputs/outputs so that we build the module from its umbrella
675   // header.
676   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
677   FrontendOpts.OutputFile = ModuleFileName.str();
678   FrontendOpts.DisableFree = false;
679   FrontendOpts.Inputs.clear();
680   FrontendOpts.Inputs.push_back(
681     std::make_pair(getSourceInputKindFromOptions(Invocation->getLangOpts()),
682                                                  UmbrellaHeader));
683 
684   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
685 
686 
687   assert(ImportingInstance.getInvocation().getModuleHash() ==
688            Invocation->getModuleHash() && "Module hash mismatch!");
689 
690   // Construct a compiler instance that will be used to actually create the
691   // module.
692   CompilerInstance Instance;
693   Instance.setInvocation(&*Invocation);
694   Instance.createDiagnostics(/*argc=*/0, /*argv=*/0,
695                              &ImportingInstance.getDiagnosticClient(),
696                              /*ShouldOwnClient=*/false);
697 
698   // Construct a module-generating action.
699   GeneratePCHAction CreateModuleAction(true);
700 
701   // Execute the action to actually build the module in-place.
702   // FIXME: Need to synchronize when multiple processes do this.
703   Instance.ExecuteAction(CreateModuleAction);
704 
705   // Tell the diagnostic client that it's (re-)starting to process a source
706   // file.
707   // FIXME: This is a hack. We probably want to clone the diagnostic client.
708   ImportingInstance.getDiagnosticClient()
709     .BeginSourceFile(ImportingInstance.getLangOpts(),
710                      &ImportingInstance.getPreprocessor());
711 }
712 
713 ModuleKey CompilerInstance::loadModule(SourceLocation ImportLoc,
714                                        IdentifierInfo &ModuleName,
715                                        SourceLocation ModuleNameLoc) {
716   // Determine what file we're searching from.
717   SourceManager &SourceMgr = getSourceManager();
718   SourceLocation ExpandedImportLoc = SourceMgr.getExpansionLoc(ImportLoc);
719   const FileEntry *CurFile
720     = SourceMgr.getFileEntryForID(SourceMgr.getFileID(ExpandedImportLoc));
721   if (!CurFile)
722     CurFile = SourceMgr.getFileEntryForID(SourceMgr.getMainFileID());
723 
724   // Search for a module with the given name.
725   std::string UmbrellaHeader;
726   std::string ModuleFileName;
727   const FileEntry *ModuleFile
728     = PP->getHeaderSearchInfo().lookupModule(ModuleName.getName(),
729                                              &ModuleFileName,
730                                              &UmbrellaHeader);
731 
732   bool BuildingModule = false;
733   if (!ModuleFile && !UmbrellaHeader.empty()) {
734     // We didn't find the module, but there is an umbrella header that
735     // can be used to create the module file. Create a separate compilation
736     // module to do so.
737 
738     // Check whether there is a cycle in the module graph.
739     SmallVectorImpl<std::string> &ModuleBuildPath
740       = getPreprocessorOpts().ModuleBuildPath;
741     SmallVectorImpl<std::string>::iterator Pos
742       = std::find(ModuleBuildPath.begin(), ModuleBuildPath.end(),
743                   ModuleName.getName());
744     if (Pos != ModuleBuildPath.end()) {
745       llvm::SmallString<256> CyclePath;
746       for (; Pos != ModuleBuildPath.end(); ++Pos) {
747         CyclePath += *Pos;
748         CyclePath += " -> ";
749       }
750       CyclePath += ModuleName.getName();
751 
752       getDiagnostics().Report(ModuleNameLoc, diag::err_module_cycle)
753         << ModuleName.getName() << CyclePath;
754       return 0;
755     }
756 
757     BuildingModule = true;
758     compileModule(*this, ModuleName.getName(), ModuleFileName, UmbrellaHeader);
759     ModuleFile = PP->getHeaderSearchInfo().lookupModule(ModuleName.getName());
760   }
761 
762   if (!ModuleFile) {
763     getDiagnostics().Report(ModuleNameLoc,
764                             BuildingModule? diag::err_module_not_built
765                                           : diag::err_module_not_found)
766       << ModuleName.getName()
767       << SourceRange(ImportLoc, ModuleNameLoc);
768     return 0;
769   }
770 
771   // If we don't already have an ASTReader, create one now.
772   if (!ModuleManager) {
773     if (!hasASTContext())
774       createASTContext();
775 
776     std::string Sysroot = getHeaderSearchOpts().Sysroot;
777     const PreprocessorOptions &PPOpts = getPreprocessorOpts();
778     ModuleManager = new ASTReader(getPreprocessor(), *Context,
779                                   Sysroot.empty() ? "" : Sysroot.c_str(),
780                                   PPOpts.DisablePCHValidation,
781                                   PPOpts.DisableStatCache);
782     if (hasASTConsumer()) {
783       ModuleManager->setDeserializationListener(
784         getASTConsumer().GetASTDeserializationListener());
785       getASTContext().setASTMutationListener(
786         getASTConsumer().GetASTMutationListener());
787     }
788     llvm::OwningPtr<ExternalASTSource> Source;
789     Source.reset(ModuleManager);
790     getASTContext().setExternalSource(Source);
791     if (hasSema())
792       ModuleManager->InitializeSema(getSema());
793     if (hasASTConsumer())
794       ModuleManager->StartTranslationUnit(&getASTConsumer());
795   }
796 
797   // Try to load the module we found.
798   switch (ModuleManager->ReadAST(ModuleFile->getName(),
799                                  serialization::MK_Module)) {
800   case ASTReader::Success:
801     break;
802 
803   case ASTReader::IgnorePCH:
804     // FIXME: The ASTReader will already have complained, but can we showhorn
805     // that diagnostic information into a more useful form?
806     return 0;
807 
808   case ASTReader::Failure:
809     // Already complained.
810     return 0;
811   }
812 
813   // FIXME: The module file's FileEntry makes a poor key indeed!
814   return (ModuleKey)ModuleFile;
815 }
816 
817