xref: /llvm-project/clang/lib/Frontend/FrontendActions.cpp (revision fdf8e3e31103bc81917cdb27150877f524bb2669) 
1 //===--- FrontendActions.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/FrontendActions.h"
10 #include "clang/AST/ASTConsumer.h"
11 #include "clang/AST/Decl.h"
12 #include "clang/Basic/FileManager.h"
13 #include "clang/Basic/LangStandard.h"
14 #include "clang/Basic/Module.h"
15 #include "clang/Basic/TargetInfo.h"
16 #include "clang/Frontend/ASTConsumers.h"
17 #include "clang/Frontend/CompilerInstance.h"
18 #include "clang/Frontend/FrontendDiagnostic.h"
19 #include "clang/Frontend/MultiplexConsumer.h"
20 #include "clang/Frontend/Utils.h"
21 #include "clang/Lex/DependencyDirectivesScanner.h"
22 #include "clang/Lex/HeaderSearch.h"
23 #include "clang/Lex/Preprocessor.h"
24 #include "clang/Lex/PreprocessorOptions.h"
25 #include "clang/Sema/TemplateInstCallback.h"
26 #include "clang/Serialization/ASTReader.h"
27 #include "clang/Serialization/ASTWriter.h"
28 #include "clang/Serialization/ModuleFile.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include "llvm/Support/FileSystem.h"
31 #include "llvm/Support/MemoryBuffer.h"
32 #include "llvm/Support/Path.h"
33 #include "llvm/Support/YAMLTraits.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include <memory>
36 #include <optional>
37 #include <system_error>
38 
39 using namespace clang;
40 
41 namespace {
42 CodeCompleteConsumer *GetCodeCompletionConsumer(CompilerInstance &CI) {
43   return CI.hasCodeCompletionConsumer() ? &CI.getCodeCompletionConsumer()
44                                         : nullptr;
45 }
46 
47 void EnsureSemaIsCreated(CompilerInstance &CI, FrontendAction &Action) {
48   if (Action.hasCodeCompletionSupport() &&
49       !CI.getFrontendOpts().CodeCompletionAt.FileName.empty())
50     CI.createCodeCompletionConsumer();
51 
52   if (!CI.hasSema())
53     CI.createSema(Action.getTranslationUnitKind(),
54                   GetCodeCompletionConsumer(CI));
55 }
56 } // namespace
57 
58 //===----------------------------------------------------------------------===//
59 // Custom Actions
60 //===----------------------------------------------------------------------===//
61 
62 std::unique_ptr<ASTConsumer>
63 InitOnlyAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
64   return std::make_unique<ASTConsumer>();
65 }
66 
67 void InitOnlyAction::ExecuteAction() {
68 }
69 
70 // Basically PreprocessOnlyAction::ExecuteAction.
71 void ReadPCHAndPreprocessAction::ExecuteAction() {
72   Preprocessor &PP = getCompilerInstance().getPreprocessor();
73 
74   // Ignore unknown pragmas.
75   PP.IgnorePragmas();
76 
77   Token Tok;
78   // Start parsing the specified input file.
79   PP.EnterMainSourceFile();
80   do {
81     PP.Lex(Tok);
82   } while (Tok.isNot(tok::eof));
83 }
84 
85 std::unique_ptr<ASTConsumer>
86 ReadPCHAndPreprocessAction::CreateASTConsumer(CompilerInstance &CI,
87                                               StringRef InFile) {
88   return std::make_unique<ASTConsumer>();
89 }
90 
91 //===----------------------------------------------------------------------===//
92 // AST Consumer Actions
93 //===----------------------------------------------------------------------===//
94 
95 std::unique_ptr<ASTConsumer>
96 ASTPrintAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
97   if (std::unique_ptr<raw_ostream> OS =
98           CI.createDefaultOutputFile(false, InFile))
99     return CreateASTPrinter(std::move(OS), CI.getFrontendOpts().ASTDumpFilter);
100   return nullptr;
101 }
102 
103 std::unique_ptr<ASTConsumer>
104 ASTDumpAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
105   const FrontendOptions &Opts = CI.getFrontendOpts();
106   return CreateASTDumper(nullptr /*Dump to stdout.*/, Opts.ASTDumpFilter,
107                          Opts.ASTDumpDecls, Opts.ASTDumpAll,
108                          Opts.ASTDumpLookups, Opts.ASTDumpDeclTypes,
109                          Opts.ASTDumpFormat);
110 }
111 
112 std::unique_ptr<ASTConsumer>
113 ASTDeclListAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
114   return CreateASTDeclNodeLister();
115 }
116 
117 std::unique_ptr<ASTConsumer>
118 ASTViewAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
119   return CreateASTViewer();
120 }
121 
122 std::unique_ptr<ASTConsumer>
123 GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
124   std::string Sysroot;
125   if (!ComputeASTConsumerArguments(CI, /*ref*/ Sysroot))
126     return nullptr;
127 
128   std::string OutputFile;
129   std::unique_ptr<raw_pwrite_stream> OS =
130       CreateOutputFile(CI, InFile, /*ref*/ OutputFile);
131   if (!OS)
132     return nullptr;
133 
134   if (!CI.getFrontendOpts().RelocatablePCH)
135     Sysroot.clear();
136 
137   const auto &FrontendOpts = CI.getFrontendOpts();
138   auto Buffer = std::make_shared<PCHBuffer>();
139   std::vector<std::unique_ptr<ASTConsumer>> Consumers;
140   Consumers.push_back(std::make_unique<PCHGenerator>(
141       CI.getPreprocessor(), CI.getModuleCache(), OutputFile, Sysroot, Buffer,
142       FrontendOpts.ModuleFileExtensions,
143       CI.getPreprocessorOpts().AllowPCHWithCompilerErrors,
144       FrontendOpts.IncludeTimestamps, FrontendOpts.BuildingImplicitModule,
145       +CI.getLangOpts().CacheGeneratedPCH));
146   Consumers.push_back(CI.getPCHContainerWriter().CreatePCHContainerGenerator(
147       CI, std::string(InFile), OutputFile, std::move(OS), Buffer));
148 
149   return std::make_unique<MultiplexConsumer>(std::move(Consumers));
150 }
151 
152 bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
153                                                     std::string &Sysroot) {
154   Sysroot = CI.getHeaderSearchOpts().Sysroot;
155   if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
156     CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
157     return false;
158   }
159 
160   return true;
161 }
162 
163 std::unique_ptr<llvm::raw_pwrite_stream>
164 GeneratePCHAction::CreateOutputFile(CompilerInstance &CI, StringRef InFile,
165                                     std::string &OutputFile) {
166   // Because this is exposed via libclang we must disable RemoveFileOnSignal.
167   std::unique_ptr<raw_pwrite_stream> OS = CI.createDefaultOutputFile(
168       /*Binary=*/true, InFile, /*Extension=*/"", /*RemoveFileOnSignal=*/false);
169   if (!OS)
170     return nullptr;
171 
172   OutputFile = CI.getFrontendOpts().OutputFile;
173   return OS;
174 }
175 
176 bool GeneratePCHAction::shouldEraseOutputFiles() {
177   if (getCompilerInstance().getPreprocessorOpts().AllowPCHWithCompilerErrors)
178     return false;
179   return ASTFrontendAction::shouldEraseOutputFiles();
180 }
181 
182 bool GeneratePCHAction::BeginSourceFileAction(CompilerInstance &CI) {
183   CI.getLangOpts().CompilingPCH = true;
184   return true;
185 }
186 
187 std::vector<std::unique_ptr<ASTConsumer>>
188 GenerateModuleAction::CreateMultiplexConsumer(CompilerInstance &CI,
189                                               StringRef InFile) {
190   std::unique_ptr<raw_pwrite_stream> OS = CreateOutputFile(CI, InFile);
191   if (!OS)
192     return {};
193 
194   std::string OutputFile = CI.getFrontendOpts().OutputFile;
195   std::string Sysroot;
196 
197   auto Buffer = std::make_shared<PCHBuffer>();
198   std::vector<std::unique_ptr<ASTConsumer>> Consumers;
199 
200   Consumers.push_back(std::make_unique<PCHGenerator>(
201       CI.getPreprocessor(), CI.getModuleCache(), OutputFile, Sysroot, Buffer,
202       CI.getFrontendOpts().ModuleFileExtensions,
203       /*AllowASTWithErrors=*/
204       +CI.getFrontendOpts().AllowPCMWithCompilerErrors,
205       /*IncludeTimestamps=*/
206       +CI.getFrontendOpts().BuildingImplicitModule &&
207           +CI.getFrontendOpts().IncludeTimestamps,
208       /*BuildingImplicitModule=*/+CI.getFrontendOpts().BuildingImplicitModule,
209       /*ShouldCacheASTInMemory=*/
210       +CI.getFrontendOpts().BuildingImplicitModule));
211   Consumers.push_back(CI.getPCHContainerWriter().CreatePCHContainerGenerator(
212       CI, std::string(InFile), OutputFile, std::move(OS), Buffer));
213   return Consumers;
214 }
215 
216 std::unique_ptr<ASTConsumer>
217 GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
218                                         StringRef InFile) {
219   std::vector<std::unique_ptr<ASTConsumer>> Consumers =
220       CreateMultiplexConsumer(CI, InFile);
221   if (Consumers.empty())
222     return nullptr;
223 
224   return std::make_unique<MultiplexConsumer>(std::move(Consumers));
225 }
226 
227 bool GenerateModuleAction::shouldEraseOutputFiles() {
228   return !getCompilerInstance().getFrontendOpts().AllowPCMWithCompilerErrors &&
229          ASTFrontendAction::shouldEraseOutputFiles();
230 }
231 
232 bool GenerateModuleFromModuleMapAction::BeginSourceFileAction(
233     CompilerInstance &CI) {
234   if (!CI.getLangOpts().Modules) {
235     CI.getDiagnostics().Report(diag::err_module_build_requires_fmodules);
236     return false;
237   }
238 
239   return GenerateModuleAction::BeginSourceFileAction(CI);
240 }
241 
242 std::unique_ptr<raw_pwrite_stream>
243 GenerateModuleFromModuleMapAction::CreateOutputFile(CompilerInstance &CI,
244                                                     StringRef InFile) {
245   // If no output file was provided, figure out where this module would go
246   // in the module cache.
247   if (CI.getFrontendOpts().OutputFile.empty()) {
248     StringRef ModuleMapFile = CI.getFrontendOpts().OriginalModuleMap;
249     if (ModuleMapFile.empty())
250       ModuleMapFile = InFile;
251 
252     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
253     CI.getFrontendOpts().OutputFile =
254         HS.getCachedModuleFileName(CI.getLangOpts().CurrentModule,
255                                    ModuleMapFile);
256   }
257 
258   // Because this is exposed via libclang we must disable RemoveFileOnSignal.
259   return CI.createDefaultOutputFile(/*Binary=*/true, InFile, /*Extension=*/"",
260                                     /*RemoveFileOnSignal=*/false,
261                                     /*CreateMissingDirectories=*/true,
262                                     /*ForceUseTemporary=*/true);
263 }
264 
265 bool GenerateModuleInterfaceAction::BeginSourceFileAction(
266     CompilerInstance &CI) {
267   CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
268 
269   return GenerateModuleAction::BeginSourceFileAction(CI);
270 }
271 
272 std::unique_ptr<ASTConsumer>
273 GenerateModuleInterfaceAction::CreateASTConsumer(CompilerInstance &CI,
274                                                  StringRef InFile) {
275   std::vector<std::unique_ptr<ASTConsumer>> Consumers;
276 
277   if (CI.getFrontendOpts().GenReducedBMI &&
278       !CI.getFrontendOpts().ModuleOutputPath.empty()) {
279     Consumers.push_back(std::make_unique<ReducedBMIGenerator>(
280         CI.getPreprocessor(), CI.getModuleCache(),
281         CI.getFrontendOpts().ModuleOutputPath));
282   }
283 
284   Consumers.push_back(std::make_unique<CXX20ModulesGenerator>(
285       CI.getPreprocessor(), CI.getModuleCache(),
286       CI.getFrontendOpts().OutputFile));
287 
288   return std::make_unique<MultiplexConsumer>(std::move(Consumers));
289 }
290 
291 std::unique_ptr<raw_pwrite_stream>
292 GenerateModuleInterfaceAction::CreateOutputFile(CompilerInstance &CI,
293                                                 StringRef InFile) {
294   return CI.createDefaultOutputFile(/*Binary=*/true, InFile, "pcm");
295 }
296 
297 std::unique_ptr<ASTConsumer>
298 GenerateReducedModuleInterfaceAction::CreateASTConsumer(CompilerInstance &CI,
299                                                         StringRef InFile) {
300   return std::make_unique<ReducedBMIGenerator>(CI.getPreprocessor(),
301                                                CI.getModuleCache(),
302                                                CI.getFrontendOpts().OutputFile);
303 }
304 
305 bool GenerateHeaderUnitAction::BeginSourceFileAction(CompilerInstance &CI) {
306   if (!CI.getLangOpts().CPlusPlusModules) {
307     CI.getDiagnostics().Report(diag::err_module_interface_requires_cpp_modules);
308     return false;
309   }
310   CI.getLangOpts().setCompilingModule(LangOptions::CMK_HeaderUnit);
311   return GenerateModuleAction::BeginSourceFileAction(CI);
312 }
313 
314 std::unique_ptr<raw_pwrite_stream>
315 GenerateHeaderUnitAction::CreateOutputFile(CompilerInstance &CI,
316                                            StringRef InFile) {
317   return CI.createDefaultOutputFile(/*Binary=*/true, InFile, "pcm");
318 }
319 
320 SyntaxOnlyAction::~SyntaxOnlyAction() {
321 }
322 
323 std::unique_ptr<ASTConsumer>
324 SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
325   return std::make_unique<ASTConsumer>();
326 }
327 
328 std::unique_ptr<ASTConsumer>
329 DumpModuleInfoAction::CreateASTConsumer(CompilerInstance &CI,
330                                         StringRef InFile) {
331   return std::make_unique<ASTConsumer>();
332 }
333 
334 std::unique_ptr<ASTConsumer>
335 VerifyPCHAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
336   return std::make_unique<ASTConsumer>();
337 }
338 
339 void VerifyPCHAction::ExecuteAction() {
340   CompilerInstance &CI = getCompilerInstance();
341   bool Preamble = CI.getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
342   const std::string &Sysroot = CI.getHeaderSearchOpts().Sysroot;
343   std::unique_ptr<ASTReader> Reader(new ASTReader(
344       CI.getPreprocessor(), CI.getModuleCache(), &CI.getASTContext(),
345       CI.getPCHContainerReader(), CI.getFrontendOpts().ModuleFileExtensions,
346       Sysroot.empty() ? "" : Sysroot.c_str(),
347       DisableValidationForModuleKind::None,
348       /*AllowASTWithCompilerErrors*/ false,
349       /*AllowConfigurationMismatch*/ true,
350       /*ValidateSystemInputs*/ true));
351 
352   Reader->ReadAST(getCurrentFile(),
353                   Preamble ? serialization::MK_Preamble
354                            : serialization::MK_PCH,
355                   SourceLocation(),
356                   ASTReader::ARR_ConfigurationMismatch);
357 }
358 
359 namespace {
360 struct TemplightEntry {
361   std::string Name;
362   std::string Kind;
363   std::string Event;
364   std::string DefinitionLocation;
365   std::string PointOfInstantiation;
366 };
367 } // namespace
368 
369 namespace llvm {
370 namespace yaml {
371 template <> struct MappingTraits<TemplightEntry> {
372   static void mapping(IO &io, TemplightEntry &fields) {
373     io.mapRequired("name", fields.Name);
374     io.mapRequired("kind", fields.Kind);
375     io.mapRequired("event", fields.Event);
376     io.mapRequired("orig", fields.DefinitionLocation);
377     io.mapRequired("poi", fields.PointOfInstantiation);
378   }
379 };
380 } // namespace yaml
381 } // namespace llvm
382 
383 namespace {
384 class DefaultTemplateInstCallback : public TemplateInstantiationCallback {
385   using CodeSynthesisContext = Sema::CodeSynthesisContext;
386 
387 public:
388   void initialize(const Sema &) override {}
389 
390   void finalize(const Sema &) override {}
391 
392   void atTemplateBegin(const Sema &TheSema,
393                        const CodeSynthesisContext &Inst) override {
394     displayTemplightEntry<true>(llvm::outs(), TheSema, Inst);
395   }
396 
397   void atTemplateEnd(const Sema &TheSema,
398                      const CodeSynthesisContext &Inst) override {
399     displayTemplightEntry<false>(llvm::outs(), TheSema, Inst);
400   }
401 
402 private:
403   static std::string toString(CodeSynthesisContext::SynthesisKind Kind) {
404     switch (Kind) {
405     case CodeSynthesisContext::TemplateInstantiation:
406       return "TemplateInstantiation";
407     case CodeSynthesisContext::DefaultTemplateArgumentInstantiation:
408       return "DefaultTemplateArgumentInstantiation";
409     case CodeSynthesisContext::DefaultFunctionArgumentInstantiation:
410       return "DefaultFunctionArgumentInstantiation";
411     case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution:
412       return "ExplicitTemplateArgumentSubstitution";
413     case CodeSynthesisContext::DeducedTemplateArgumentSubstitution:
414       return "DeducedTemplateArgumentSubstitution";
415     case CodeSynthesisContext::LambdaExpressionSubstitution:
416       return "LambdaExpressionSubstitution";
417     case CodeSynthesisContext::PriorTemplateArgumentSubstitution:
418       return "PriorTemplateArgumentSubstitution";
419     case CodeSynthesisContext::DefaultTemplateArgumentChecking:
420       return "DefaultTemplateArgumentChecking";
421     case CodeSynthesisContext::ExceptionSpecEvaluation:
422       return "ExceptionSpecEvaluation";
423     case CodeSynthesisContext::ExceptionSpecInstantiation:
424       return "ExceptionSpecInstantiation";
425     case CodeSynthesisContext::DeclaringSpecialMember:
426       return "DeclaringSpecialMember";
427     case CodeSynthesisContext::DeclaringImplicitEqualityComparison:
428       return "DeclaringImplicitEqualityComparison";
429     case CodeSynthesisContext::DefiningSynthesizedFunction:
430       return "DefiningSynthesizedFunction";
431     case CodeSynthesisContext::RewritingOperatorAsSpaceship:
432       return "RewritingOperatorAsSpaceship";
433     case CodeSynthesisContext::Memoization:
434       return "Memoization";
435     case CodeSynthesisContext::ConstraintsCheck:
436       return "ConstraintsCheck";
437     case CodeSynthesisContext::ConstraintSubstitution:
438       return "ConstraintSubstitution";
439     case CodeSynthesisContext::ConstraintNormalization:
440       return "ConstraintNormalization";
441     case CodeSynthesisContext::RequirementParameterInstantiation:
442       return "RequirementParameterInstantiation";
443     case CodeSynthesisContext::ParameterMappingSubstitution:
444       return "ParameterMappingSubstitution";
445     case CodeSynthesisContext::RequirementInstantiation:
446       return "RequirementInstantiation";
447     case CodeSynthesisContext::NestedRequirementConstraintsCheck:
448       return "NestedRequirementConstraintsCheck";
449     case CodeSynthesisContext::InitializingStructuredBinding:
450       return "InitializingStructuredBinding";
451     case CodeSynthesisContext::MarkingClassDllexported:
452       return "MarkingClassDllexported";
453     case CodeSynthesisContext::BuildingBuiltinDumpStructCall:
454       return "BuildingBuiltinDumpStructCall";
455     case CodeSynthesisContext::BuildingDeductionGuides:
456       return "BuildingDeductionGuides";
457     case CodeSynthesisContext::TypeAliasTemplateInstantiation:
458       return "TypeAliasTemplateInstantiation";
459     }
460     return "";
461   }
462 
463   template <bool BeginInstantiation>
464   static void displayTemplightEntry(llvm::raw_ostream &Out, const Sema &TheSema,
465                                     const CodeSynthesisContext &Inst) {
466     std::string YAML;
467     {
468       llvm::raw_string_ostream OS(YAML);
469       llvm::yaml::Output YO(OS);
470       TemplightEntry Entry =
471           getTemplightEntry<BeginInstantiation>(TheSema, Inst);
472       llvm::yaml::EmptyContext Context;
473       llvm::yaml::yamlize(YO, Entry, true, Context);
474     }
475     Out << "---" << YAML << "\n";
476   }
477 
478   static void printEntryName(const Sema &TheSema, const Decl *Entity,
479                              llvm::raw_string_ostream &OS) {
480     auto *NamedTemplate = cast<NamedDecl>(Entity);
481 
482     PrintingPolicy Policy = TheSema.Context.getPrintingPolicy();
483     // FIXME: Also ask for FullyQualifiedNames?
484     Policy.SuppressDefaultTemplateArgs = false;
485     NamedTemplate->getNameForDiagnostic(OS, Policy, true);
486 
487     if (!OS.str().empty())
488       return;
489 
490     Decl *Ctx = Decl::castFromDeclContext(NamedTemplate->getDeclContext());
491     NamedDecl *NamedCtx = dyn_cast_or_null<NamedDecl>(Ctx);
492 
493     if (const auto *Decl = dyn_cast<TagDecl>(NamedTemplate)) {
494       if (const auto *R = dyn_cast<RecordDecl>(Decl)) {
495         if (R->isLambda()) {
496           OS << "lambda at ";
497           Decl->getLocation().print(OS, TheSema.getSourceManager());
498           return;
499         }
500       }
501       OS << "unnamed " << Decl->getKindName();
502       return;
503     }
504 
505     assert(NamedCtx && "NamedCtx cannot be null");
506 
507     if (const auto *Decl = dyn_cast<ParmVarDecl>(NamedTemplate)) {
508       OS << "unnamed function parameter " << Decl->getFunctionScopeIndex()
509          << " ";
510       if (Decl->getFunctionScopeDepth() > 0)
511         OS << "(at depth " << Decl->getFunctionScopeDepth() << ") ";
512       OS << "of ";
513       NamedCtx->getNameForDiagnostic(OS, TheSema.getLangOpts(), true);
514       return;
515     }
516 
517     if (const auto *Decl = dyn_cast<TemplateTypeParmDecl>(NamedTemplate)) {
518       if (const Type *Ty = Decl->getTypeForDecl()) {
519         if (const auto *TTPT = dyn_cast_or_null<TemplateTypeParmType>(Ty)) {
520           OS << "unnamed template type parameter " << TTPT->getIndex() << " ";
521           if (TTPT->getDepth() > 0)
522             OS << "(at depth " << TTPT->getDepth() << ") ";
523           OS << "of ";
524           NamedCtx->getNameForDiagnostic(OS, TheSema.getLangOpts(), true);
525           return;
526         }
527       }
528     }
529 
530     if (const auto *Decl = dyn_cast<NonTypeTemplateParmDecl>(NamedTemplate)) {
531       OS << "unnamed template non-type parameter " << Decl->getIndex() << " ";
532       if (Decl->getDepth() > 0)
533         OS << "(at depth " << Decl->getDepth() << ") ";
534       OS << "of ";
535       NamedCtx->getNameForDiagnostic(OS, TheSema.getLangOpts(), true);
536       return;
537     }
538 
539     if (const auto *Decl = dyn_cast<TemplateTemplateParmDecl>(NamedTemplate)) {
540       OS << "unnamed template template parameter " << Decl->getIndex() << " ";
541       if (Decl->getDepth() > 0)
542         OS << "(at depth " << Decl->getDepth() << ") ";
543       OS << "of ";
544       NamedCtx->getNameForDiagnostic(OS, TheSema.getLangOpts(), true);
545       return;
546     }
547 
548     llvm_unreachable("Failed to retrieve a name for this entry!");
549     OS << "unnamed identifier";
550   }
551 
552   template <bool BeginInstantiation>
553   static TemplightEntry getTemplightEntry(const Sema &TheSema,
554                                           const CodeSynthesisContext &Inst) {
555     TemplightEntry Entry;
556     Entry.Kind = toString(Inst.Kind);
557     Entry.Event = BeginInstantiation ? "Begin" : "End";
558     llvm::raw_string_ostream OS(Entry.Name);
559     printEntryName(TheSema, Inst.Entity, OS);
560     const PresumedLoc DefLoc =
561         TheSema.getSourceManager().getPresumedLoc(Inst.Entity->getLocation());
562     if (!DefLoc.isInvalid())
563       Entry.DefinitionLocation = std::string(DefLoc.getFilename()) + ":" +
564                                  std::to_string(DefLoc.getLine()) + ":" +
565                                  std::to_string(DefLoc.getColumn());
566     const PresumedLoc PoiLoc =
567         TheSema.getSourceManager().getPresumedLoc(Inst.PointOfInstantiation);
568     if (!PoiLoc.isInvalid()) {
569       Entry.PointOfInstantiation = std::string(PoiLoc.getFilename()) + ":" +
570                                    std::to_string(PoiLoc.getLine()) + ":" +
571                                    std::to_string(PoiLoc.getColumn());
572     }
573     return Entry;
574   }
575 };
576 } // namespace
577 
578 std::unique_ptr<ASTConsumer>
579 TemplightDumpAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
580   return std::make_unique<ASTConsumer>();
581 }
582 
583 void TemplightDumpAction::ExecuteAction() {
584   CompilerInstance &CI = getCompilerInstance();
585 
586   // This part is normally done by ASTFrontEndAction, but needs to happen
587   // before Templight observers can be created
588   // FIXME: Move the truncation aspect of this into Sema, we delayed this till
589   // here so the source manager would be initialized.
590   EnsureSemaIsCreated(CI, *this);
591 
592   CI.getSema().TemplateInstCallbacks.push_back(
593       std::make_unique<DefaultTemplateInstCallback>());
594   ASTFrontendAction::ExecuteAction();
595 }
596 
597 namespace {
598   /// AST reader listener that dumps module information for a module
599   /// file.
600   class DumpModuleInfoListener : public ASTReaderListener {
601     llvm::raw_ostream &Out;
602 
603   public:
604     DumpModuleInfoListener(llvm::raw_ostream &Out) : Out(Out) { }
605 
606 #define DUMP_BOOLEAN(Value, Text)                       \
607     Out.indent(4) << Text << ": " << (Value? "Yes" : "No") << "\n"
608 
609     bool ReadFullVersionInformation(StringRef FullVersion) override {
610       Out.indent(2)
611         << "Generated by "
612         << (FullVersion == getClangFullRepositoryVersion()? "this"
613                                                           : "a different")
614         << " Clang: " << FullVersion << "\n";
615       return ASTReaderListener::ReadFullVersionInformation(FullVersion);
616     }
617 
618     void ReadModuleName(StringRef ModuleName) override {
619       Out.indent(2) << "Module name: " << ModuleName << "\n";
620     }
621     void ReadModuleMapFile(StringRef ModuleMapPath) override {
622       Out.indent(2) << "Module map file: " << ModuleMapPath << "\n";
623     }
624 
625     bool ReadLanguageOptions(const LangOptions &LangOpts, StringRef ModuleFilename, bool Complain,
626                              bool AllowCompatibleDifferences) override {
627       Out.indent(2) << "Language options:\n";
628 #define LANGOPT(Name, Bits, Default, Description) \
629       DUMP_BOOLEAN(LangOpts.Name, Description);
630 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
631       Out.indent(4) << Description << ": "                   \
632                     << static_cast<unsigned>(LangOpts.get##Name()) << "\n";
633 #define VALUE_LANGOPT(Name, Bits, Default, Description) \
634       Out.indent(4) << Description << ": " << LangOpts.Name << "\n";
635 #define BENIGN_LANGOPT(Name, Bits, Default, Description)
636 #define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
637 #include "clang/Basic/LangOptions.def"
638 
639       if (!LangOpts.ModuleFeatures.empty()) {
640         Out.indent(4) << "Module features:\n";
641         for (StringRef Feature : LangOpts.ModuleFeatures)
642           Out.indent(6) << Feature << "\n";
643       }
644 
645       return false;
646     }
647 
648     bool ReadTargetOptions(const TargetOptions &TargetOpts, StringRef ModuleFilename, bool Complain,
649                            bool AllowCompatibleDifferences) override {
650       Out.indent(2) << "Target options:\n";
651       Out.indent(4) << "  Triple: " << TargetOpts.Triple << "\n";
652       Out.indent(4) << "  CPU: " << TargetOpts.CPU << "\n";
653       Out.indent(4) << "  TuneCPU: " << TargetOpts.TuneCPU << "\n";
654       Out.indent(4) << "  ABI: " << TargetOpts.ABI << "\n";
655 
656       if (!TargetOpts.FeaturesAsWritten.empty()) {
657         Out.indent(4) << "Target features:\n";
658         for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size();
659              I != N; ++I) {
660           Out.indent(6) << TargetOpts.FeaturesAsWritten[I] << "\n";
661         }
662       }
663 
664       return false;
665     }
666 
667     bool ReadDiagnosticOptions(IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts,
668                                StringRef ModuleFilename, bool Complain) override {
669       Out.indent(2) << "Diagnostic options:\n";
670 #define DIAGOPT(Name, Bits, Default) DUMP_BOOLEAN(DiagOpts->Name, #Name);
671 #define ENUM_DIAGOPT(Name, Type, Bits, Default) \
672       Out.indent(4) << #Name << ": " << DiagOpts->get##Name() << "\n";
673 #define VALUE_DIAGOPT(Name, Bits, Default) \
674       Out.indent(4) << #Name << ": " << DiagOpts->Name << "\n";
675 #include "clang/Basic/DiagnosticOptions.def"
676 
677       Out.indent(4) << "Diagnostic flags:\n";
678       for (const std::string &Warning : DiagOpts->Warnings)
679         Out.indent(6) << "-W" << Warning << "\n";
680       for (const std::string &Remark : DiagOpts->Remarks)
681         Out.indent(6) << "-R" << Remark << "\n";
682 
683       return false;
684     }
685 
686     bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
687                                  StringRef ModuleFilename,
688                                  StringRef SpecificModuleCachePath,
689                                  bool Complain) override {
690       Out.indent(2) << "Header search options:\n";
691       Out.indent(4) << "System root [-isysroot=]: '" << HSOpts.Sysroot << "'\n";
692       Out.indent(4) << "Resource dir [ -resource-dir=]: '" << HSOpts.ResourceDir << "'\n";
693       Out.indent(4) << "Module Cache: '" << SpecificModuleCachePath << "'\n";
694       DUMP_BOOLEAN(HSOpts.UseBuiltinIncludes,
695                    "Use builtin include directories [-nobuiltininc]");
696       DUMP_BOOLEAN(HSOpts.UseStandardSystemIncludes,
697                    "Use standard system include directories [-nostdinc]");
698       DUMP_BOOLEAN(HSOpts.UseStandardCXXIncludes,
699                    "Use standard C++ include directories [-nostdinc++]");
700       DUMP_BOOLEAN(HSOpts.UseLibcxx,
701                    "Use libc++ (rather than libstdc++) [-stdlib=]");
702       return false;
703     }
704 
705     bool ReadHeaderSearchPaths(const HeaderSearchOptions &HSOpts,
706                                bool Complain) override {
707       Out.indent(2) << "Header search paths:\n";
708       Out.indent(4) << "User entries:\n";
709       for (const auto &Entry : HSOpts.UserEntries)
710         Out.indent(6) << Entry.Path << "\n";
711       Out.indent(4) << "System header prefixes:\n";
712       for (const auto &Prefix : HSOpts.SystemHeaderPrefixes)
713         Out.indent(6) << Prefix.Prefix << "\n";
714       Out.indent(4) << "VFS overlay files:\n";
715       for (const auto &Overlay : HSOpts.VFSOverlayFiles)
716         Out.indent(6) << Overlay << "\n";
717       return false;
718     }
719 
720     bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
721                                  StringRef ModuleFilename,
722                                  bool ReadMacros, bool Complain,
723                                  std::string &SuggestedPredefines) override {
724       Out.indent(2) << "Preprocessor options:\n";
725       DUMP_BOOLEAN(PPOpts.UsePredefines,
726                    "Uses compiler/target-specific predefines [-undef]");
727       DUMP_BOOLEAN(PPOpts.DetailedRecord,
728                    "Uses detailed preprocessing record (for indexing)");
729 
730       if (ReadMacros) {
731         Out.indent(4) << "Predefined macros:\n";
732       }
733 
734       for (std::vector<std::pair<std::string, bool/*isUndef*/> >::const_iterator
735              I = PPOpts.Macros.begin(), IEnd = PPOpts.Macros.end();
736            I != IEnd; ++I) {
737         Out.indent(6);
738         if (I->second)
739           Out << "-U";
740         else
741           Out << "-D";
742         Out << I->first << "\n";
743       }
744       return false;
745     }
746 
747     /// Indicates that a particular module file extension has been read.
748     void readModuleFileExtension(
749            const ModuleFileExtensionMetadata &Metadata) override {
750       Out.indent(2) << "Module file extension '"
751                     << Metadata.BlockName << "' " << Metadata.MajorVersion
752                     << "." << Metadata.MinorVersion;
753       if (!Metadata.UserInfo.empty()) {
754         Out << ": ";
755         Out.write_escaped(Metadata.UserInfo);
756       }
757 
758       Out << "\n";
759     }
760 
761     /// Tells the \c ASTReaderListener that we want to receive the
762     /// input files of the AST file via \c visitInputFile.
763     bool needsInputFileVisitation() override { return true; }
764 
765     /// Tells the \c ASTReaderListener that we want to receive the
766     /// input files of the AST file via \c visitInputFile.
767     bool needsSystemInputFileVisitation() override { return true; }
768 
769     /// Indicates that the AST file contains particular input file.
770     ///
771     /// \returns true to continue receiving the next input file, false to stop.
772     bool visitInputFile(StringRef Filename, bool isSystem,
773                         bool isOverridden, bool isExplicitModule) override {
774 
775       Out.indent(2) << "Input file: " << Filename;
776 
777       if (isSystem || isOverridden || isExplicitModule) {
778         Out << " [";
779         if (isSystem) {
780           Out << "System";
781           if (isOverridden || isExplicitModule)
782             Out << ", ";
783         }
784         if (isOverridden) {
785           Out << "Overridden";
786           if (isExplicitModule)
787             Out << ", ";
788         }
789         if (isExplicitModule)
790           Out << "ExplicitModule";
791 
792         Out << "]";
793       }
794 
795       Out << "\n";
796 
797       return true;
798     }
799 
800     /// Returns true if this \c ASTReaderListener wants to receive the
801     /// imports of the AST file via \c visitImport, false otherwise.
802     bool needsImportVisitation() const override { return true; }
803 
804     /// If needsImportVisitation returns \c true, this is called for each
805     /// AST file imported by this AST file.
806     void visitImport(StringRef ModuleName, StringRef Filename) override {
807       Out.indent(2) << "Imports module '" << ModuleName
808                     << "': " << Filename.str() << "\n";
809     }
810 #undef DUMP_BOOLEAN
811   };
812 }
813 
814 bool DumpModuleInfoAction::BeginInvocation(CompilerInstance &CI) {
815   // The Object file reader also supports raw ast files and there is no point in
816   // being strict about the module file format in -module-file-info mode.
817   CI.getHeaderSearchOpts().ModuleFormat = "obj";
818   return true;
819 }
820 
821 static StringRef ModuleKindName(Module::ModuleKind MK) {
822   switch (MK) {
823   case Module::ModuleMapModule:
824     return "Module Map Module";
825   case Module::ModuleInterfaceUnit:
826     return "Interface Unit";
827   case Module::ModuleImplementationUnit:
828     return "Implementation Unit";
829   case Module::ModulePartitionInterface:
830     return "Partition Interface";
831   case Module::ModulePartitionImplementation:
832     return "Partition Implementation";
833   case Module::ModuleHeaderUnit:
834     return "Header Unit";
835   case Module::ExplicitGlobalModuleFragment:
836     return "Global Module Fragment";
837   case Module::ImplicitGlobalModuleFragment:
838     return "Implicit Module Fragment";
839   case Module::PrivateModuleFragment:
840     return "Private Module Fragment";
841   }
842   llvm_unreachable("unknown module kind!");
843 }
844 
845 void DumpModuleInfoAction::ExecuteAction() {
846   CompilerInstance &CI = getCompilerInstance();
847 
848   // Don't process files of type other than module to avoid crash
849   if (!isCurrentFileAST()) {
850     CI.getDiagnostics().Report(diag::err_file_is_not_module)
851         << getCurrentFile();
852     return;
853   }
854 
855   // Set up the output file.
856   StringRef OutputFileName = CI.getFrontendOpts().OutputFile;
857   if (!OutputFileName.empty() && OutputFileName != "-") {
858     std::error_code EC;
859     OutputStream.reset(new llvm::raw_fd_ostream(
860         OutputFileName.str(), EC, llvm::sys::fs::OF_TextWithCRLF));
861   }
862   llvm::raw_ostream &Out = OutputStream ? *OutputStream : llvm::outs();
863 
864   Out << "Information for module file '" << getCurrentFile() << "':\n";
865   auto &FileMgr = CI.getFileManager();
866   auto Buffer = FileMgr.getBufferForFile(getCurrentFile());
867   StringRef Magic = (*Buffer)->getMemBufferRef().getBuffer();
868   bool IsRaw = Magic.starts_with("CPCH");
869   Out << "  Module format: " << (IsRaw ? "raw" : "obj") << "\n";
870 
871   Preprocessor &PP = CI.getPreprocessor();
872   DumpModuleInfoListener Listener(Out);
873   HeaderSearchOptions &HSOpts = PP.getHeaderSearchInfo().getHeaderSearchOpts();
874 
875   // The FrontendAction::BeginSourceFile () method loads the AST so that much
876   // of the information is already available and modules should have been
877   // loaded.
878 
879   const LangOptions &LO = getCurrentASTUnit().getLangOpts();
880   if (LO.CPlusPlusModules && !LO.CurrentModule.empty()) {
881     ASTReader *R = getCurrentASTUnit().getASTReader().get();
882     unsigned SubModuleCount = R->getTotalNumSubmodules();
883     serialization::ModuleFile &MF = R->getModuleManager().getPrimaryModule();
884     Out << "  ====== C++20 Module structure ======\n";
885 
886     if (MF.ModuleName != LO.CurrentModule)
887       Out << "  Mismatched module names : " << MF.ModuleName << " and "
888           << LO.CurrentModule << "\n";
889 
890     struct SubModInfo {
891       unsigned Idx;
892       Module *Mod;
893       Module::ModuleKind Kind;
894       std::string &Name;
895       bool Seen;
896     };
897     std::map<std::string, SubModInfo> SubModMap;
898     auto PrintSubMapEntry = [&](std::string Name, Module::ModuleKind Kind) {
899       Out << "    " << ModuleKindName(Kind) << " '" << Name << "'";
900       auto I = SubModMap.find(Name);
901       if (I == SubModMap.end())
902         Out << " was not found in the sub modules!\n";
903       else {
904         I->second.Seen = true;
905         Out << " is at index #" << I->second.Idx << "\n";
906       }
907     };
908     Module *Primary = nullptr;
909     for (unsigned Idx = 0; Idx <= SubModuleCount; ++Idx) {
910       Module *M = R->getModule(Idx);
911       if (!M)
912         continue;
913       if (M->Name == LO.CurrentModule) {
914         Primary = M;
915         Out << "  " << ModuleKindName(M->Kind) << " '" << LO.CurrentModule
916             << "' is the Primary Module at index #" << Idx << "\n";
917         SubModMap.insert({M->Name, {Idx, M, M->Kind, M->Name, true}});
918       } else
919         SubModMap.insert({M->Name, {Idx, M, M->Kind, M->Name, false}});
920     }
921     if (Primary) {
922       if (!Primary->submodules().empty())
923         Out << "   Sub Modules:\n";
924       for (auto *MI : Primary->submodules()) {
925         PrintSubMapEntry(MI->Name, MI->Kind);
926       }
927       if (!Primary->Imports.empty())
928         Out << "   Imports:\n";
929       for (auto *IMP : Primary->Imports) {
930         PrintSubMapEntry(IMP->Name, IMP->Kind);
931       }
932       if (!Primary->Exports.empty())
933         Out << "   Exports:\n";
934       for (unsigned MN = 0, N = Primary->Exports.size(); MN != N; ++MN) {
935         if (Module *M = Primary->Exports[MN].getPointer()) {
936           PrintSubMapEntry(M->Name, M->Kind);
937         }
938       }
939     }
940 
941     // Emit the macro definitions in the module file so that we can know how
942     // much definitions in the module file quickly.
943     // TODO: Emit the macro definition bodies completely.
944     if (auto FilteredMacros = llvm::make_filter_range(
945             R->getPreprocessor().macros(),
946             [](const auto &Macro) { return Macro.first->isFromAST(); });
947         !FilteredMacros.empty()) {
948       Out << "   Macro Definitions:\n";
949       for (/*<IdentifierInfo *, MacroState> pair*/ const auto &Macro :
950            FilteredMacros)
951         Out << "     " << Macro.first->getName() << "\n";
952     }
953 
954     // Now let's print out any modules we did not see as part of the Primary.
955     for (const auto &SM : SubModMap) {
956       if (!SM.second.Seen && SM.second.Mod) {
957         Out << "  " << ModuleKindName(SM.second.Kind) << " '" << SM.first
958             << "' at index #" << SM.second.Idx
959             << " has no direct reference in the Primary\n";
960       }
961     }
962     Out << "  ====== ======\n";
963   }
964 
965   // The reminder of the output is produced from the listener as the AST
966   // FileCcontrolBlock is (re-)parsed.
967   ASTReader::readASTFileControlBlock(
968       getCurrentFile(), FileMgr, CI.getModuleCache(),
969       CI.getPCHContainerReader(),
970       /*FindModuleFileExtensions=*/true, Listener,
971       HSOpts.ModulesValidateDiagnosticOptions);
972 }
973 
974 //===----------------------------------------------------------------------===//
975 // Preprocessor Actions
976 //===----------------------------------------------------------------------===//
977 
978 void DumpRawTokensAction::ExecuteAction() {
979   Preprocessor &PP = getCompilerInstance().getPreprocessor();
980   SourceManager &SM = PP.getSourceManager();
981 
982   // Start lexing the specified input file.
983   llvm::MemoryBufferRef FromFile = SM.getBufferOrFake(SM.getMainFileID());
984   Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
985   RawLex.SetKeepWhitespaceMode(true);
986 
987   Token RawTok;
988   RawLex.LexFromRawLexer(RawTok);
989   while (RawTok.isNot(tok::eof)) {
990     PP.DumpToken(RawTok, true);
991     llvm::errs() << "\n";
992     RawLex.LexFromRawLexer(RawTok);
993   }
994 }
995 
996 void DumpTokensAction::ExecuteAction() {
997   Preprocessor &PP = getCompilerInstance().getPreprocessor();
998   // Start preprocessing the specified input file.
999   Token Tok;
1000   PP.EnterMainSourceFile();
1001   do {
1002     PP.Lex(Tok);
1003     PP.DumpToken(Tok, true);
1004     llvm::errs() << "\n";
1005   } while (Tok.isNot(tok::eof));
1006 }
1007 
1008 void PreprocessOnlyAction::ExecuteAction() {
1009   Preprocessor &PP = getCompilerInstance().getPreprocessor();
1010 
1011   // Ignore unknown pragmas.
1012   PP.IgnorePragmas();
1013 
1014   Token Tok;
1015   // Start parsing the specified input file.
1016   PP.EnterMainSourceFile();
1017   do {
1018     PP.Lex(Tok);
1019   } while (Tok.isNot(tok::eof));
1020 }
1021 
1022 void PrintPreprocessedAction::ExecuteAction() {
1023   CompilerInstance &CI = getCompilerInstance();
1024   // Output file may need to be set to 'Binary', to avoid converting Unix style
1025   // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>) on Windows.
1026   //
1027   // Look to see what type of line endings the file uses. If there's a
1028   // CRLF, then we won't open the file up in binary mode. If there is
1029   // just an LF or CR, then we will open the file up in binary mode.
1030   // In this fashion, the output format should match the input format, unless
1031   // the input format has inconsistent line endings.
1032   //
1033   // This should be a relatively fast operation since most files won't have
1034   // all of their source code on a single line. However, that is still a
1035   // concern, so if we scan for too long, we'll just assume the file should
1036   // be opened in binary mode.
1037 
1038   bool BinaryMode = false;
1039   if (llvm::Triple(LLVM_HOST_TRIPLE).isOSWindows()) {
1040     BinaryMode = true;
1041     const SourceManager &SM = CI.getSourceManager();
1042     if (std::optional<llvm::MemoryBufferRef> Buffer =
1043             SM.getBufferOrNone(SM.getMainFileID())) {
1044       const char *cur = Buffer->getBufferStart();
1045       const char *end = Buffer->getBufferEnd();
1046       const char *next = (cur != end) ? cur + 1 : end;
1047 
1048       // Limit ourselves to only scanning 256 characters into the source
1049       // file.  This is mostly a check in case the file has no
1050       // newlines whatsoever.
1051       if (end - cur > 256)
1052         end = cur + 256;
1053 
1054       while (next < end) {
1055         if (*cur == 0x0D) {  // CR
1056           if (*next == 0x0A) // CRLF
1057             BinaryMode = false;
1058 
1059           break;
1060         } else if (*cur == 0x0A) // LF
1061           break;
1062 
1063         ++cur;
1064         ++next;
1065       }
1066     }
1067   }
1068 
1069   std::unique_ptr<raw_ostream> OS =
1070       CI.createDefaultOutputFile(BinaryMode, getCurrentFileOrBufferName());
1071   if (!OS) return;
1072 
1073   // If we're preprocessing a module map, start by dumping the contents of the
1074   // module itself before switching to the input buffer.
1075   auto &Input = getCurrentInput();
1076   if (Input.getKind().getFormat() == InputKind::ModuleMap) {
1077     if (Input.isFile()) {
1078       (*OS) << "# 1 \"";
1079       OS->write_escaped(Input.getFile());
1080       (*OS) << "\"\n";
1081     }
1082     getCurrentModule()->print(*OS);
1083     (*OS) << "#pragma clang module contents\n";
1084   }
1085 
1086   DoPrintPreprocessedInput(CI.getPreprocessor(), OS.get(),
1087                            CI.getPreprocessorOutputOpts());
1088 }
1089 
1090 void PrintPreambleAction::ExecuteAction() {
1091   switch (getCurrentFileKind().getLanguage()) {
1092   case Language::C:
1093   case Language::CXX:
1094   case Language::ObjC:
1095   case Language::ObjCXX:
1096   case Language::OpenCL:
1097   case Language::OpenCLCXX:
1098   case Language::CUDA:
1099   case Language::HIP:
1100   case Language::HLSL:
1101   case Language::CIR:
1102     break;
1103 
1104   case Language::Unknown:
1105   case Language::Asm:
1106   case Language::LLVM_IR:
1107   case Language::RenderScript:
1108     // We can't do anything with these.
1109     return;
1110   }
1111 
1112   // We don't expect to find any #include directives in a preprocessed input.
1113   if (getCurrentFileKind().isPreprocessed())
1114     return;
1115 
1116   CompilerInstance &CI = getCompilerInstance();
1117   auto Buffer = CI.getFileManager().getBufferForFile(getCurrentFile());
1118   if (Buffer) {
1119     unsigned Preamble =
1120         Lexer::ComputePreamble((*Buffer)->getBuffer(), CI.getLangOpts()).Size;
1121     llvm::outs().write((*Buffer)->getBufferStart(), Preamble);
1122   }
1123 }
1124 
1125 void DumpCompilerOptionsAction::ExecuteAction() {
1126   CompilerInstance &CI = getCompilerInstance();
1127   std::unique_ptr<raw_ostream> OSP =
1128       CI.createDefaultOutputFile(false, getCurrentFile());
1129   if (!OSP)
1130     return;
1131 
1132   raw_ostream &OS = *OSP;
1133   const Preprocessor &PP = CI.getPreprocessor();
1134   const LangOptions &LangOpts = PP.getLangOpts();
1135 
1136   // FIXME: Rather than manually format the JSON (which is awkward due to
1137   // needing to remove trailing commas), this should make use of a JSON library.
1138   // FIXME: Instead of printing enums as an integral value and specifying the
1139   // type as a separate field, use introspection to print the enumerator.
1140 
1141   OS << "{\n";
1142   OS << "\n\"features\" : [\n";
1143   {
1144     llvm::SmallString<128> Str;
1145 #define FEATURE(Name, Predicate)                                               \
1146   ("\t{\"" #Name "\" : " + llvm::Twine(Predicate ? "true" : "false") + "},\n") \
1147       .toVector(Str);
1148 #include "clang/Basic/Features.def"
1149 #undef FEATURE
1150     // Remove the newline and comma from the last entry to ensure this remains
1151     // valid JSON.
1152     OS << Str.substr(0, Str.size() - 2);
1153   }
1154   OS << "\n],\n";
1155 
1156   OS << "\n\"extensions\" : [\n";
1157   {
1158     llvm::SmallString<128> Str;
1159 #define EXTENSION(Name, Predicate)                                             \
1160   ("\t{\"" #Name "\" : " + llvm::Twine(Predicate ? "true" : "false") + "},\n") \
1161       .toVector(Str);
1162 #include "clang/Basic/Features.def"
1163 #undef EXTENSION
1164     // Remove the newline and comma from the last entry to ensure this remains
1165     // valid JSON.
1166     OS << Str.substr(0, Str.size() - 2);
1167   }
1168   OS << "\n]\n";
1169 
1170   OS << "}";
1171 }
1172 
1173 void PrintDependencyDirectivesSourceMinimizerAction::ExecuteAction() {
1174   CompilerInstance &CI = getCompilerInstance();
1175   SourceManager &SM = CI.getPreprocessor().getSourceManager();
1176   llvm::MemoryBufferRef FromFile = SM.getBufferOrFake(SM.getMainFileID());
1177 
1178   llvm::SmallVector<dependency_directives_scan::Token, 16> Tokens;
1179   llvm::SmallVector<dependency_directives_scan::Directive, 32> Directives;
1180   if (scanSourceForDependencyDirectives(
1181           FromFile.getBuffer(), Tokens, Directives, &CI.getDiagnostics(),
1182           SM.getLocForStartOfFile(SM.getMainFileID()))) {
1183     assert(CI.getDiagnostics().hasErrorOccurred() &&
1184            "no errors reported for failure");
1185 
1186     // Preprocess the source when verifying the diagnostics to capture the
1187     // 'expected' comments.
1188     if (CI.getDiagnosticOpts().VerifyDiagnostics) {
1189       // Make sure we don't emit new diagnostics!
1190       CI.getDiagnostics().setSuppressAllDiagnostics(true);
1191       Preprocessor &PP = getCompilerInstance().getPreprocessor();
1192       PP.EnterMainSourceFile();
1193       Token Tok;
1194       do {
1195         PP.Lex(Tok);
1196       } while (Tok.isNot(tok::eof));
1197     }
1198     return;
1199   }
1200   printDependencyDirectivesAsSource(FromFile.getBuffer(), Directives,
1201                                     llvm::outs());
1202 }
1203 
1204 void GetDependenciesByModuleNameAction::ExecuteAction() {
1205   CompilerInstance &CI = getCompilerInstance();
1206   Preprocessor &PP = CI.getPreprocessor();
1207   SourceManager &SM = PP.getSourceManager();
1208   FileID MainFileID = SM.getMainFileID();
1209   SourceLocation FileStart = SM.getLocForStartOfFile(MainFileID);
1210   SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
1211   IdentifierInfo *ModuleID = PP.getIdentifierInfo(ModuleName);
1212   Path.push_back(std::make_pair(ModuleID, FileStart));
1213   auto ModResult = CI.loadModule(FileStart, Path, Module::Hidden, false);
1214   PPCallbacks *CB = PP.getPPCallbacks();
1215   CB->moduleImport(SourceLocation(), Path, ModResult);
1216 }
1217