1 //===--- FrontendActions.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/FrontendActions.h"
11 #include "clang/AST/ASTConsumer.h"
12 #include "clang/Basic/FileManager.h"
13 #include "clang/Frontend/ASTConsumers.h"
14 #include "clang/Frontend/ASTUnit.h"
15 #include "clang/Frontend/CompilerInstance.h"
16 #include "clang/Frontend/FrontendDiagnostic.h"
17 #include "clang/Frontend/Utils.h"
18 #include "clang/Lex/HeaderSearch.h"
19 #include "clang/Lex/Pragma.h"
20 #include "clang/Lex/Preprocessor.h"
21 #include "clang/Parse/Parser.h"
22 #include "clang/Serialization/ASTReader.h"
23 #include "clang/Serialization/ASTWriter.h"
24 #include "llvm/ADT/OwningPtr.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/MemoryBuffer.h"
27 #include "llvm/Support/raw_ostream.h"
28 #include "llvm/Support/system_error.h"
29 
30 using namespace clang;
31 
32 //===----------------------------------------------------------------------===//
33 // Custom Actions
34 //===----------------------------------------------------------------------===//
35 
36 ASTConsumer *InitOnlyAction::CreateASTConsumer(CompilerInstance &CI,
37                                                StringRef InFile) {
38   return new ASTConsumer();
39 }
40 
41 void InitOnlyAction::ExecuteAction() {
42 }
43 
44 //===----------------------------------------------------------------------===//
45 // AST Consumer Actions
46 //===----------------------------------------------------------------------===//
47 
48 ASTConsumer *ASTPrintAction::CreateASTConsumer(CompilerInstance &CI,
49                                                StringRef InFile) {
50   if (raw_ostream *OS = CI.createDefaultOutputFile(false, InFile))
51     return CreateASTPrinter(OS, CI.getFrontendOpts().ASTDumpFilter);
52   return 0;
53 }
54 
55 ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
56                                               StringRef InFile) {
57   return CreateASTDumper(CI.getFrontendOpts().ASTDumpFilter);
58 }
59 
60 ASTConsumer *ASTDeclListAction::CreateASTConsumer(CompilerInstance &CI,
61                                                   StringRef InFile) {
62   return CreateASTDeclNodeLister();
63 }
64 
65 ASTConsumer *ASTDumpXMLAction::CreateASTConsumer(CompilerInstance &CI,
66                                                  StringRef InFile) {
67   raw_ostream *OS;
68   if (CI.getFrontendOpts().OutputFile.empty())
69     OS = &llvm::outs();
70   else
71     OS = CI.createDefaultOutputFile(false, InFile);
72   if (!OS) return 0;
73   return CreateASTDumperXML(*OS);
74 }
75 
76 ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
77                                               StringRef InFile) {
78   return CreateASTViewer();
79 }
80 
81 ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
82                                                        StringRef InFile) {
83   return CreateDeclContextPrinter();
84 }
85 
86 ASTConsumer *GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI,
87                                                   StringRef InFile) {
88   std::string Sysroot;
89   std::string OutputFile;
90   raw_ostream *OS = 0;
91   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
92     return 0;
93 
94   if (!CI.getFrontendOpts().RelocatablePCH)
95     Sysroot.clear();
96   return new PCHGenerator(CI.getPreprocessor(), OutputFile, 0, Sysroot, OS);
97 }
98 
99 bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
100                                                     StringRef InFile,
101                                                     std::string &Sysroot,
102                                                     std::string &OutputFile,
103                                                     raw_ostream *&OS) {
104   Sysroot = CI.getHeaderSearchOpts().Sysroot;
105   if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
106     CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
107     return true;
108   }
109 
110   // We use createOutputFile here because this is exposed via libclang, and we
111   // must disable the RemoveFileOnSignal behavior.
112   // We use a temporary to avoid race conditions.
113   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
114                            /*RemoveFileOnSignal=*/false, InFile,
115                            /*Extension=*/"", /*useTemporary=*/true);
116   if (!OS)
117     return true;
118 
119   OutputFile = CI.getFrontendOpts().OutputFile;
120   return false;
121 }
122 
123 ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
124                                                      StringRef InFile) {
125   std::string Sysroot;
126   std::string OutputFile;
127   raw_ostream *OS = 0;
128   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
129     return 0;
130 
131   return new PCHGenerator(CI.getPreprocessor(), OutputFile, Module,
132                           Sysroot, OS);
133 }
134 
135 static SmallVectorImpl<char> &
136 operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
137   Includes.append(RHS.begin(), RHS.end());
138   return Includes;
139 }
140 
141 static void addHeaderInclude(StringRef HeaderName,
142                              SmallVectorImpl<char> &Includes,
143                              const LangOptions &LangOpts) {
144   if (LangOpts.ObjC1)
145     Includes += "#import \"";
146   else
147     Includes += "#include \"";
148   Includes += HeaderName;
149   Includes += "\"\n";
150 }
151 
152 static void addHeaderInclude(const FileEntry *Header,
153                              SmallVectorImpl<char> &Includes,
154                              const LangOptions &LangOpts) {
155   addHeaderInclude(Header->getName(), Includes, LangOpts);
156 }
157 
158 /// \brief Collect the set of header includes needed to construct the given
159 /// module and update the TopHeaders file set of the module.
160 ///
161 /// \param Module The module we're collecting includes from.
162 ///
163 /// \param Includes Will be augmented with the set of \#includes or \#imports
164 /// needed to load all of the named headers.
165 static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
166                                         FileManager &FileMgr,
167                                         ModuleMap &ModMap,
168                                         clang::Module *Module,
169                                         SmallVectorImpl<char> &Includes) {
170   // Don't collect any headers for unavailable modules.
171   if (!Module->isAvailable())
172     return;
173 
174   // Add includes for each of these headers.
175   for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
176     const FileEntry *Header = Module->Headers[I];
177     Module->addTopHeader(Header);
178     addHeaderInclude(Header, Includes, LangOpts);
179   }
180 
181   if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
182     Module->addTopHeader(UmbrellaHeader);
183     if (Module->Parent) {
184       // Include the umbrella header for submodules.
185       addHeaderInclude(UmbrellaHeader, Includes, LangOpts);
186     }
187   } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
188     // Add all of the headers we find in this subdirectory.
189     llvm::error_code EC;
190     SmallString<128> DirNative;
191     llvm::sys::path::native(UmbrellaDir->getName(), DirNative);
192     for (llvm::sys::fs::recursive_directory_iterator Dir(DirNative.str(), EC),
193                                                      DirEnd;
194          Dir != DirEnd && !EC; Dir.increment(EC)) {
195       // Check whether this entry has an extension typically associated with
196       // headers.
197       if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
198           .Cases(".h", ".H", ".hh", ".hpp", true)
199           .Default(false))
200         continue;
201 
202       // If this header is marked 'unavailable' in this module, don't include
203       // it.
204       if (const FileEntry *Header = FileMgr.getFile(Dir->path())) {
205         if (ModMap.isHeaderInUnavailableModule(Header))
206           continue;
207         Module->addTopHeader(Header);
208       }
209 
210       // Include this header umbrella header for submodules.
211       addHeaderInclude(Dir->path(), Includes, LangOpts);
212     }
213   }
214 
215   // Recurse into submodules.
216   for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
217                                       SubEnd = Module->submodule_end();
218        Sub != SubEnd; ++Sub)
219     collectModuleHeaderIncludes(LangOpts, FileMgr, ModMap, *Sub, Includes);
220 }
221 
222 bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
223                                                  StringRef Filename) {
224   // Find the module map file.
225   const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
226   if (!ModuleMap)  {
227     CI.getDiagnostics().Report(diag::err_module_map_not_found)
228       << Filename;
229     return false;
230   }
231 
232   // Parse the module map file.
233   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
234   if (HS.loadModuleMapFile(ModuleMap))
235     return false;
236 
237   if (CI.getLangOpts().CurrentModule.empty()) {
238     CI.getDiagnostics().Report(diag::err_missing_module_name);
239 
240     // FIXME: Eventually, we could consider asking whether there was just
241     // a single module described in the module map, and use that as a
242     // default. Then it would be fairly trivial to just "compile" a module
243     // map with a single module (the common case).
244     return false;
245   }
246 
247   // Dig out the module definition.
248   Module = HS.lookupModule(CI.getLangOpts().CurrentModule,
249                            /*AllowSearch=*/false);
250   if (!Module) {
251     CI.getDiagnostics().Report(diag::err_missing_module)
252       << CI.getLangOpts().CurrentModule << Filename;
253 
254     return false;
255   }
256 
257   // Check whether we can build this module at all.
258   StringRef Feature;
259   if (!Module->isAvailable(CI.getLangOpts(), CI.getTarget(), Feature)) {
260     CI.getDiagnostics().Report(diag::err_module_unavailable)
261       << Module->getFullModuleName()
262       << Feature;
263 
264     return false;
265   }
266 
267   FileManager &FileMgr = CI.getFileManager();
268 
269   // Collect the set of #includes we need to build the module.
270   SmallString<256> HeaderContents;
271   if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader())
272     addHeaderInclude(UmbrellaHeader, HeaderContents, CI.getLangOpts());
273   collectModuleHeaderIncludes(CI.getLangOpts(), FileMgr,
274     CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
275     Module, HeaderContents);
276 
277   llvm::MemoryBuffer *InputBuffer =
278       llvm::MemoryBuffer::getMemBufferCopy(HeaderContents,
279                                            Module::getModuleInputBufferName());
280   // Ownership of InputBuffer will be transfered to the SourceManager.
281   setCurrentInput(FrontendInputFile(InputBuffer, getCurrentFileKind(),
282                                     Module->IsSystem));
283   return true;
284 }
285 
286 bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
287                                                        StringRef InFile,
288                                                        std::string &Sysroot,
289                                                        std::string &OutputFile,
290                                                        raw_ostream *&OS) {
291   // If no output file was provided, figure out where this module would go
292   // in the module cache.
293   if (CI.getFrontendOpts().OutputFile.empty()) {
294     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
295     SmallString<256> ModuleFileName(HS.getModuleCachePath());
296     llvm::sys::path::append(ModuleFileName,
297                             CI.getLangOpts().CurrentModule + ".pcm");
298     CI.getFrontendOpts().OutputFile = ModuleFileName.str();
299   }
300 
301   // We use createOutputFile here because this is exposed via libclang, and we
302   // must disable the RemoveFileOnSignal behavior.
303   // We use a temporary to avoid race conditions.
304   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
305                            /*RemoveFileOnSignal=*/false, InFile,
306                            /*Extension=*/"", /*useTemporary=*/true,
307                            /*CreateMissingDirectories=*/true);
308   if (!OS)
309     return true;
310 
311   OutputFile = CI.getFrontendOpts().OutputFile;
312   return false;
313 }
314 
315 ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
316                                                  StringRef InFile) {
317   return new ASTConsumer();
318 }
319 
320 ASTConsumer *DumpModuleInfoAction::CreateASTConsumer(CompilerInstance &CI,
321                                                      StringRef InFile) {
322   return new ASTConsumer();
323 }
324 
325 namespace {
326   /// \brief AST reader listener that dumps module information for a module
327   /// file.
328   class DumpModuleInfoListener : public ASTReaderListener {
329     llvm::raw_ostream &Out;
330 
331   public:
332     DumpModuleInfoListener(llvm::raw_ostream &Out) : Out(Out) { }
333 
334 #define DUMP_BOOLEAN(Value, Text)                       \
335     Out.indent(4) << Text << ": " << (Value? "Yes" : "No") << "\n"
336 
337     virtual bool ReadFullVersionInformation(StringRef FullVersion) {
338       Out.indent(2)
339         << "Generated by "
340         << (FullVersion == getClangFullRepositoryVersion()? "this"
341                                                           : "a different")
342         << " Clang: " << FullVersion << "\n";
343       return ASTReaderListener::ReadFullVersionInformation(FullVersion);
344     }
345 
346     virtual bool ReadLanguageOptions(const LangOptions &LangOpts,
347                                      bool Complain) {
348       Out.indent(2) << "Language options:\n";
349 #define LANGOPT(Name, Bits, Default, Description) \
350       DUMP_BOOLEAN(LangOpts.Name, Description);
351 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
352       Out.indent(4) << Description << ": "                   \
353                     << static_cast<unsigned>(LangOpts.get##Name()) << "\n";
354 #define VALUE_LANGOPT(Name, Bits, Default, Description) \
355       Out.indent(4) << Description << ": " << LangOpts.Name << "\n";
356 #define BENIGN_LANGOPT(Name, Bits, Default, Description)
357 #define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
358 #include "clang/Basic/LangOptions.def"
359       return false;
360     }
361 
362     virtual bool ReadTargetOptions(const TargetOptions &TargetOpts,
363                                    bool Complain) {
364       Out.indent(2) << "Target options:\n";
365       Out.indent(4) << "  Triple: " << TargetOpts.Triple << "\n";
366       Out.indent(4) << "  CPU: " << TargetOpts.CPU << "\n";
367       Out.indent(4) << "  ABI: " << TargetOpts.ABI << "\n";
368       Out.indent(4) << "  C++ ABI: " << TargetOpts.CXXABI << "\n";
369       Out.indent(4) << "  Linker version: " << TargetOpts.LinkerVersion << "\n";
370 
371       if (!TargetOpts.FeaturesAsWritten.empty()) {
372         Out.indent(4) << "Target features:\n";
373         for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size();
374              I != N; ++I) {
375           Out.indent(6) << TargetOpts.FeaturesAsWritten[I] << "\n";
376         }
377       }
378 
379       return false;
380     }
381 
382     virtual bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
383                                          bool Complain) {
384       Out.indent(2) << "Header search options:\n";
385       Out.indent(4) << "System root [-isysroot=]: '" << HSOpts.Sysroot << "'\n";
386       DUMP_BOOLEAN(HSOpts.UseBuiltinIncludes,
387                    "Use builtin include directories [-nobuiltininc]");
388       DUMP_BOOLEAN(HSOpts.UseStandardSystemIncludes,
389                    "Use standard system include directories [-nostdinc]");
390       DUMP_BOOLEAN(HSOpts.UseStandardCXXIncludes,
391                    "Use standard C++ include directories [-nostdinc++]");
392       DUMP_BOOLEAN(HSOpts.UseLibcxx,
393                    "Use libc++ (rather than libstdc++) [-stdlib=]");
394       return false;
395     }
396 
397     virtual bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
398                                          bool Complain,
399                                          std::string &SuggestedPredefines) {
400       Out.indent(2) << "Preprocessor options:\n";
401       DUMP_BOOLEAN(PPOpts.UsePredefines,
402                    "Uses compiler/target-specific predefines [-undef]");
403       DUMP_BOOLEAN(PPOpts.DetailedRecord,
404                    "Uses detailed preprocessing record (for indexing)");
405 
406       if (!PPOpts.Macros.empty()) {
407         Out.indent(4) << "Predefined macros:\n";
408       }
409 
410       for (std::vector<std::pair<std::string, bool/*isUndef*/> >::const_iterator
411              I = PPOpts.Macros.begin(), IEnd = PPOpts.Macros.end();
412            I != IEnd; ++I) {
413         Out.indent(6);
414         if (I->second)
415           Out << "-U";
416         else
417           Out << "-D";
418         Out << I->first << "\n";
419       }
420       return false;
421     }
422 #undef DUMP_BOOLEAN
423   };
424 }
425 
426 void DumpModuleInfoAction::ExecuteAction() {
427   // Set up the output file.
428   llvm::OwningPtr<llvm::raw_fd_ostream> OutFile;
429   StringRef OutputFileName = getCompilerInstance().getFrontendOpts().OutputFile;
430   if (!OutputFileName.empty() && OutputFileName != "-") {
431     std::string ErrorInfo;
432     OutFile.reset(new llvm::raw_fd_ostream(OutputFileName.str().c_str(),
433                                            ErrorInfo));
434   }
435   llvm::raw_ostream &Out = OutFile.get()? *OutFile.get() : llvm::outs();
436 
437   Out << "Information for module file '" << getCurrentFile() << "':\n";
438   DumpModuleInfoListener Listener(Out);
439   ASTReader::readASTFileControlBlock(getCurrentFile(),
440                                      getCompilerInstance().getFileManager(),
441                                      Listener);
442 }
443 
444 //===----------------------------------------------------------------------===//
445 // Preprocessor Actions
446 //===----------------------------------------------------------------------===//
447 
448 void DumpRawTokensAction::ExecuteAction() {
449   Preprocessor &PP = getCompilerInstance().getPreprocessor();
450   SourceManager &SM = PP.getSourceManager();
451 
452   // Start lexing the specified input file.
453   const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
454   Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
455   RawLex.SetKeepWhitespaceMode(true);
456 
457   Token RawTok;
458   RawLex.LexFromRawLexer(RawTok);
459   while (RawTok.isNot(tok::eof)) {
460     PP.DumpToken(RawTok, true);
461     llvm::errs() << "\n";
462     RawLex.LexFromRawLexer(RawTok);
463   }
464 }
465 
466 void DumpTokensAction::ExecuteAction() {
467   Preprocessor &PP = getCompilerInstance().getPreprocessor();
468   // Start preprocessing the specified input file.
469   Token Tok;
470   PP.EnterMainSourceFile();
471   do {
472     PP.Lex(Tok);
473     PP.DumpToken(Tok, true);
474     llvm::errs() << "\n";
475   } while (Tok.isNot(tok::eof));
476 }
477 
478 void GeneratePTHAction::ExecuteAction() {
479   CompilerInstance &CI = getCompilerInstance();
480   if (CI.getFrontendOpts().OutputFile.empty() ||
481       CI.getFrontendOpts().OutputFile == "-") {
482     // FIXME: Don't fail this way.
483     // FIXME: Verify that we can actually seek in the given file.
484     llvm::report_fatal_error("PTH requires a seekable file for output!");
485   }
486   llvm::raw_fd_ostream *OS =
487     CI.createDefaultOutputFile(true, getCurrentFile());
488   if (!OS) return;
489 
490   CacheTokens(CI.getPreprocessor(), OS);
491 }
492 
493 void PreprocessOnlyAction::ExecuteAction() {
494   Preprocessor &PP = getCompilerInstance().getPreprocessor();
495 
496   // Ignore unknown pragmas.
497   PP.AddPragmaHandler(new EmptyPragmaHandler());
498 
499   Token Tok;
500   // Start parsing the specified input file.
501   PP.EnterMainSourceFile();
502   do {
503     PP.Lex(Tok);
504   } while (Tok.isNot(tok::eof));
505 }
506 
507 void PrintPreprocessedAction::ExecuteAction() {
508   CompilerInstance &CI = getCompilerInstance();
509   // Output file may need to be set to 'Binary', to avoid converting Unix style
510   // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
511   //
512   // Look to see what type of line endings the file uses. If there's a
513   // CRLF, then we won't open the file up in binary mode. If there is
514   // just an LF or CR, then we will open the file up in binary mode.
515   // In this fashion, the output format should match the input format, unless
516   // the input format has inconsistent line endings.
517   //
518   // This should be a relatively fast operation since most files won't have
519   // all of their source code on a single line. However, that is still a
520   // concern, so if we scan for too long, we'll just assume the file should
521   // be opened in binary mode.
522   bool BinaryMode = true;
523   bool InvalidFile = false;
524   const SourceManager& SM = CI.getSourceManager();
525   const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
526                                                      &InvalidFile);
527   if (!InvalidFile) {
528     const char *cur = Buffer->getBufferStart();
529     const char *end = Buffer->getBufferEnd();
530     const char *next = (cur != end) ? cur + 1 : end;
531 
532     // Limit ourselves to only scanning 256 characters into the source
533     // file.  This is mostly a sanity check in case the file has no
534     // newlines whatsoever.
535     if (end - cur > 256) end = cur + 256;
536 
537     while (next < end) {
538       if (*cur == 0x0D) {  // CR
539         if (*next == 0x0A)  // CRLF
540           BinaryMode = false;
541 
542         break;
543       } else if (*cur == 0x0A)  // LF
544         break;
545 
546       ++cur, ++next;
547     }
548   }
549 
550   raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
551   if (!OS) return;
552 
553   DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
554                            CI.getPreprocessorOutputOpts());
555 }
556 
557 void PrintPreambleAction::ExecuteAction() {
558   switch (getCurrentFileKind()) {
559   case IK_C:
560   case IK_CXX:
561   case IK_ObjC:
562   case IK_ObjCXX:
563   case IK_OpenCL:
564   case IK_CUDA:
565     break;
566 
567   case IK_None:
568   case IK_Asm:
569   case IK_PreprocessedC:
570   case IK_PreprocessedCXX:
571   case IK_PreprocessedObjC:
572   case IK_PreprocessedObjCXX:
573   case IK_AST:
574   case IK_LLVM_IR:
575     // We can't do anything with these.
576     return;
577   }
578 
579   CompilerInstance &CI = getCompilerInstance();
580   llvm::MemoryBuffer *Buffer
581       = CI.getFileManager().getBufferForFile(getCurrentFile());
582   if (Buffer) {
583     unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
584     llvm::outs().write(Buffer->getBufferStart(), Preamble);
585     delete Buffer;
586   }
587 }
588