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      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/ASTWriter.h"
     23 #include "llvm/ADT/OwningPtr.h"
     24 #include "llvm/Support/FileSystem.h"
     25 #include "llvm/Support/MemoryBuffer.h"
     26 #include "llvm/Support/raw_ostream.h"
     27 #include "llvm/Support/system_error.h"
     28 
     29 using namespace clang;
     30 
     31 //===----------------------------------------------------------------------===//
     32 // Custom Actions
     33 //===----------------------------------------------------------------------===//
     34 
     35 ASTConsumer *InitOnlyAction::CreateASTConsumer(CompilerInstance &CI,
     36                                                StringRef InFile) {
     37   return new ASTConsumer();
     38 }
     39 
     40 void InitOnlyAction::ExecuteAction() {
     41 }
     42 
     43 //===----------------------------------------------------------------------===//
     44 // AST Consumer Actions
     45 //===----------------------------------------------------------------------===//
     46 
     47 ASTConsumer *ASTPrintAction::CreateASTConsumer(CompilerInstance &CI,
     48                                                StringRef InFile) {
     49   if (raw_ostream *OS = CI.createDefaultOutputFile(false, InFile))
     50     return CreateASTPrinter(OS, CI.getFrontendOpts().ASTDumpFilter);
     51   return 0;
     52 }
     53 
     54 ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
     55                                               StringRef InFile) {
     56   return CreateASTDumper(CI.getFrontendOpts().ASTDumpFilter);
     57 }
     58 
     59 ASTConsumer *ASTDeclListAction::CreateASTConsumer(CompilerInstance &CI,
     60                                                   StringRef InFile) {
     61   return CreateASTDeclNodeLister();
     62 }
     63 
     64 ASTConsumer *ASTDumpXMLAction::CreateASTConsumer(CompilerInstance &CI,
     65                                                  StringRef InFile) {
     66   raw_ostream *OS;
     67   if (CI.getFrontendOpts().OutputFile.empty())
     68     OS = &llvm::outs();
     69   else
     70     OS = CI.createDefaultOutputFile(false, InFile);
     71   if (!OS) return 0;
     72   return CreateASTDumperXML(*OS);
     73 }
     74 
     75 ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
     76                                               StringRef InFile) {
     77   return CreateASTViewer();
     78 }
     79 
     80 ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
     81                                                        StringRef InFile) {
     82   return CreateDeclContextPrinter();
     83 }
     84 
     85 ASTConsumer *GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI,
     86                                                   StringRef InFile) {
     87   std::string Sysroot;
     88   std::string OutputFile;
     89   raw_ostream *OS = 0;
     90   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
     91     return 0;
     92 
     93   if (!CI.getFrontendOpts().RelocatablePCH)
     94     Sysroot.clear();
     95   return new PCHGenerator(CI.getPreprocessor(), OutputFile, 0, Sysroot, OS);
     96 }
     97 
     98 bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
     99                                                     StringRef InFile,
    100                                                     std::string &Sysroot,
    101                                                     std::string &OutputFile,
    102                                                     raw_ostream *&OS) {
    103   Sysroot = CI.getHeaderSearchOpts().Sysroot;
    104   if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
    105     CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
    106     return true;
    107   }
    108 
    109   // We use createOutputFile here because this is exposed via libclang, and we
    110   // must disable the RemoveFileOnSignal behavior.
    111   // We use a temporary to avoid race conditions.
    112   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
    113                            /*RemoveFileOnSignal=*/false, InFile,
    114                            /*Extension=*/"", /*useTemporary=*/true);
    115   if (!OS)
    116     return true;
    117 
    118   OutputFile = CI.getFrontendOpts().OutputFile;
    119   return false;
    120 }
    121 
    122 ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
    123                                                      StringRef InFile) {
    124   std::string Sysroot;
    125   std::string OutputFile;
    126   raw_ostream *OS = 0;
    127   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
    128     return 0;
    129 
    130   return new PCHGenerator(CI.getPreprocessor(), OutputFile, Module,
    131                           Sysroot, OS);
    132 }
    133 
    134 static SmallVectorImpl<char> &
    135 operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
    136   Includes.append(RHS.begin(), RHS.end());
    137   return Includes;
    138 }
    139 
    140 static void addHeaderInclude(StringRef HeaderName,
    141                              SmallVectorImpl<char> &Includes,
    142                              const LangOptions &LangOpts) {
    143   if (LangOpts.ObjC1)
    144     Includes += "#import \"";
    145   else
    146     Includes += "#include \"";
    147   Includes += HeaderName;
    148   Includes += "\"\n";
    149 }
    150 
    151 static void addHeaderInclude(const FileEntry *Header,
    152                              SmallVectorImpl<char> &Includes,
    153                              const LangOptions &LangOpts) {
    154   addHeaderInclude(Header->getName(), Includes, LangOpts);
    155 }
    156 
    157 /// \brief Collect the set of header includes needed to construct the given
    158 /// module and update the TopHeaders file set of the module.
    159 ///
    160 /// \param Module The module we're collecting includes from.
    161 ///
    162 /// \param Includes Will be augmented with the set of \#includes or \#imports
    163 /// needed to load all of the named headers.
    164 static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
    165                                         FileManager &FileMgr,
    166                                         ModuleMap &ModMap,
    167                                         clang::Module *Module,
    168                                         SmallVectorImpl<char> &Includes) {
    169   // Don't collect any headers for unavailable modules.
    170   if (!Module->isAvailable())
    171     return;
    172 
    173   // Add includes for each of these headers.
    174   for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
    175     const FileEntry *Header = Module->Headers[I];
    176     Module->addTopHeader(Header);
    177     addHeaderInclude(Header, Includes, LangOpts);
    178   }
    179 
    180   if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
    181     Module->addTopHeader(UmbrellaHeader);
    182     if (Module->Parent) {
    183       // Include the umbrella header for submodules.
    184       addHeaderInclude(UmbrellaHeader, Includes, LangOpts);
    185     }
    186   } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
    187     // Add all of the headers we find in this subdirectory.
    188     llvm::error_code EC;
    189     SmallString<128> DirNative;
    190     llvm::sys::path::native(UmbrellaDir->getName(), DirNative);
    191     for (llvm::sys::fs::recursive_directory_iterator Dir(DirNative.str(), EC),
    192                                                      DirEnd;
    193          Dir != DirEnd && !EC; Dir.increment(EC)) {
    194       // Check whether this entry has an extension typically associated with
    195       // headers.
    196       if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
    197           .Cases(".h", ".H", ".hh", ".hpp", true)
    198           .Default(false))
    199         continue;
    200 
    201       // If this header is marked 'unavailable' in this module, don't include
    202       // it.
    203       if (const FileEntry *Header = FileMgr.getFile(Dir->path())) {
    204         if (ModMap.isHeaderInUnavailableModule(Header))
    205           continue;
    206         Module->addTopHeader(Header);
    207       }
    208 
    209       // Include this header umbrella header for submodules.
    210       addHeaderInclude(Dir->path(), Includes, LangOpts);
    211     }
    212   }
    213 
    214   // Recurse into submodules.
    215   for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
    216                                       SubEnd = Module->submodule_end();
    217        Sub != SubEnd; ++Sub)
    218     collectModuleHeaderIncludes(LangOpts, FileMgr, ModMap, *Sub, Includes);
    219 }
    220 
    221 bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
    222                                                  StringRef Filename) {
    223   // Find the module map file.
    224   const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
    225   if (!ModuleMap)  {
    226     CI.getDiagnostics().Report(diag::err_module_map_not_found)
    227       << Filename;
    228     return false;
    229   }
    230 
    231   // Parse the module map file.
    232   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
    233   if (HS.loadModuleMapFile(ModuleMap))
    234     return false;
    235 
    236   if (CI.getLangOpts().CurrentModule.empty()) {
    237     CI.getDiagnostics().Report(diag::err_missing_module_name);
    238 
    239     // FIXME: Eventually, we could consider asking whether there was just
    240     // a single module described in the module map, and use that as a
    241     // default. Then it would be fairly trivial to just "compile" a module
    242     // map with a single module (the common case).
    243     return false;
    244   }
    245 
    246   // Dig out the module definition.
    247   Module = HS.lookupModule(CI.getLangOpts().CurrentModule,
    248                            /*AllowSearch=*/false);
    249   if (!Module) {
    250     CI.getDiagnostics().Report(diag::err_missing_module)
    251       << CI.getLangOpts().CurrentModule << Filename;
    252 
    253     return false;
    254   }
    255 
    256   // Check whether we can build this module at all.
    257   StringRef Feature;
    258   if (!Module->isAvailable(CI.getLangOpts(), CI.getTarget(), Feature)) {
    259     CI.getDiagnostics().Report(diag::err_module_unavailable)
    260       << Module->getFullModuleName()
    261       << Feature;
    262 
    263     return false;
    264   }
    265 
    266   FileManager &FileMgr = CI.getFileManager();
    267 
    268   // Collect the set of #includes we need to build the module.
    269   SmallString<256> HeaderContents;
    270   if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader())
    271     addHeaderInclude(UmbrellaHeader, HeaderContents, CI.getLangOpts());
    272   collectModuleHeaderIncludes(CI.getLangOpts(), FileMgr,
    273     CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
    274     Module, HeaderContents);
    275 
    276   llvm::MemoryBuffer *InputBuffer =
    277       llvm::MemoryBuffer::getMemBufferCopy(HeaderContents,
    278                                            Module::getModuleInputBufferName());
    279   // Ownership of InputBuffer will be transfered to the SourceManager.
    280   setCurrentInput(FrontendInputFile(InputBuffer, getCurrentFileKind(),
    281                                     Module->IsSystem));
    282   return true;
    283 }
    284 
    285 bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
    286                                                        StringRef InFile,
    287                                                        std::string &Sysroot,
    288                                                        std::string &OutputFile,
    289                                                        raw_ostream *&OS) {
    290   // If no output file was provided, figure out where this module would go
    291   // in the module cache.
    292   if (CI.getFrontendOpts().OutputFile.empty()) {
    293     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
    294     SmallString<256> ModuleFileName(HS.getModuleCachePath());
    295     llvm::sys::path::append(ModuleFileName,
    296                             CI.getLangOpts().CurrentModule + ".pcm");
    297     CI.getFrontendOpts().OutputFile = ModuleFileName.str();
    298   }
    299 
    300   // We use createOutputFile here because this is exposed via libclang, and we
    301   // must disable the RemoveFileOnSignal behavior.
    302   // We use a temporary to avoid race conditions.
    303   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
    304                            /*RemoveFileOnSignal=*/false, InFile,
    305                            /*Extension=*/"", /*useTemporary=*/true,
    306                            /*CreateMissingDirectories=*/true);
    307   if (!OS)
    308     return true;
    309 
    310   OutputFile = CI.getFrontendOpts().OutputFile;
    311   return false;
    312 }
    313 
    314 ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
    315                                                  StringRef InFile) {
    316   return new ASTConsumer();
    317 }
    318 
    319 //===----------------------------------------------------------------------===//
    320 // Preprocessor Actions
    321 //===----------------------------------------------------------------------===//
    322 
    323 void DumpRawTokensAction::ExecuteAction() {
    324   Preprocessor &PP = getCompilerInstance().getPreprocessor();
    325   SourceManager &SM = PP.getSourceManager();
    326 
    327   // Start lexing the specified input file.
    328   const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
    329   Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
    330   RawLex.SetKeepWhitespaceMode(true);
    331 
    332   Token RawTok;
    333   RawLex.LexFromRawLexer(RawTok);
    334   while (RawTok.isNot(tok::eof)) {
    335     PP.DumpToken(RawTok, true);
    336     llvm::errs() << "\n";
    337     RawLex.LexFromRawLexer(RawTok);
    338   }
    339 }
    340 
    341 void DumpTokensAction::ExecuteAction() {
    342   Preprocessor &PP = getCompilerInstance().getPreprocessor();
    343   // Start preprocessing the specified input file.
    344   Token Tok;
    345   PP.EnterMainSourceFile();
    346   do {
    347     PP.Lex(Tok);
    348     PP.DumpToken(Tok, true);
    349     llvm::errs() << "\n";
    350   } while (Tok.isNot(tok::eof));
    351 }
    352 
    353 void GeneratePTHAction::ExecuteAction() {
    354   CompilerInstance &CI = getCompilerInstance();
    355   if (CI.getFrontendOpts().OutputFile.empty() ||
    356       CI.getFrontendOpts().OutputFile == "-") {
    357     // FIXME: Don't fail this way.
    358     // FIXME: Verify that we can actually seek in the given file.
    359     llvm::report_fatal_error("PTH requires a seekable file for output!");
    360   }
    361   llvm::raw_fd_ostream *OS =
    362     CI.createDefaultOutputFile(true, getCurrentFile());
    363   if (!OS) return;
    364 
    365   CacheTokens(CI.getPreprocessor(), OS);
    366 }
    367 
    368 void PreprocessOnlyAction::ExecuteAction() {
    369   Preprocessor &PP = getCompilerInstance().getPreprocessor();
    370 
    371   // Ignore unknown pragmas.
    372   PP.AddPragmaHandler(new EmptyPragmaHandler());
    373 
    374   Token Tok;
    375   // Start parsing the specified input file.
    376   PP.EnterMainSourceFile();
    377   do {
    378     PP.Lex(Tok);
    379   } while (Tok.isNot(tok::eof));
    380 }
    381 
    382 void PrintPreprocessedAction::ExecuteAction() {
    383   CompilerInstance &CI = getCompilerInstance();
    384   // Output file may need to be set to 'Binary', to avoid converting Unix style
    385   // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
    386   //
    387   // Look to see what type of line endings the file uses. If there's a
    388   // CRLF, then we won't open the file up in binary mode. If there is
    389   // just an LF or CR, then we will open the file up in binary mode.
    390   // In this fashion, the output format should match the input format, unless
    391   // the input format has inconsistent line endings.
    392   //
    393   // This should be a relatively fast operation since most files won't have
    394   // all of their source code on a single line. However, that is still a
    395   // concern, so if we scan for too long, we'll just assume the file should
    396   // be opened in binary mode.
    397   bool BinaryMode = true;
    398   bool InvalidFile = false;
    399   const SourceManager& SM = CI.getSourceManager();
    400   const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
    401                                                      &InvalidFile);
    402   if (!InvalidFile) {
    403     const char *cur = Buffer->getBufferStart();
    404     const char *end = Buffer->getBufferEnd();
    405     const char *next = (cur != end) ? cur + 1 : end;
    406 
    407     // Limit ourselves to only scanning 256 characters into the source
    408     // file.  This is mostly a sanity check in case the file has no
    409     // newlines whatsoever.
    410     if (end - cur > 256) end = cur + 256;
    411 
    412     while (next < end) {
    413       if (*cur == 0x0D) {  // CR
    414         if (*next == 0x0A)  // CRLF
    415           BinaryMode = false;
    416 
    417         break;
    418       } else if (*cur == 0x0A)  // LF
    419         break;
    420 
    421       ++cur, ++next;
    422     }
    423   }
    424 
    425   raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
    426   if (!OS) return;
    427 
    428   DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
    429                            CI.getPreprocessorOutputOpts());
    430 }
    431 
    432 void PrintPreambleAction::ExecuteAction() {
    433   switch (getCurrentFileKind()) {
    434   case IK_C:
    435   case IK_CXX:
    436   case IK_ObjC:
    437   case IK_ObjCXX:
    438   case IK_OpenCL:
    439   case IK_CUDA:
    440     break;
    441 
    442   case IK_None:
    443   case IK_Asm:
    444   case IK_PreprocessedC:
    445   case IK_PreprocessedCXX:
    446   case IK_PreprocessedObjC:
    447   case IK_PreprocessedObjCXX:
    448   case IK_AST:
    449   case IK_LLVM_IR:
    450     // We can't do anything with these.
    451     return;
    452   }
    453 
    454   CompilerInstance &CI = getCompilerInstance();
    455   llvm::MemoryBuffer *Buffer
    456       = CI.getFileManager().getBufferForFile(getCurrentFile());
    457   if (Buffer) {
    458     unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
    459     llvm::outs().write(Buffer->getBufferStart(), Preamble);
    460     delete Buffer;
    461   }
    462 }
    463