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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/Lex/HeaderSearch.h"
     13 #include "clang/Lex/Pragma.h"
     14 #include "clang/Lex/Preprocessor.h"
     15 #include "clang/Parse/Parser.h"
     16 #include "clang/Basic/FileManager.h"
     17 #include "clang/Frontend/ASTConsumers.h"
     18 #include "clang/Frontend/ASTUnit.h"
     19 #include "clang/Frontend/CompilerInstance.h"
     20 #include "clang/Frontend/FrontendDiagnostic.h"
     21 #include "clang/Frontend/Utils.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);
     51   return 0;
     52 }
     53 
     54 ASTConsumer *ASTDumpAction::CreateASTConsumer(CompilerInstance &CI,
     55                                               StringRef InFile) {
     56   return CreateASTDumper();
     57 }
     58 
     59 ASTConsumer *ASTDumpXMLAction::CreateASTConsumer(CompilerInstance &CI,
     60                                                  StringRef InFile) {
     61   raw_ostream *OS;
     62   if (CI.getFrontendOpts().OutputFile.empty())
     63     OS = &llvm::outs();
     64   else
     65     OS = CI.createDefaultOutputFile(false, InFile);
     66   if (!OS) return 0;
     67   return CreateASTDumperXML(*OS);
     68 }
     69 
     70 ASTConsumer *ASTViewAction::CreateASTConsumer(CompilerInstance &CI,
     71                                               StringRef InFile) {
     72   return CreateASTViewer();
     73 }
     74 
     75 ASTConsumer *DeclContextPrintAction::CreateASTConsumer(CompilerInstance &CI,
     76                                                        StringRef InFile) {
     77   return CreateDeclContextPrinter();
     78 }
     79 
     80 ASTConsumer *GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI,
     81                                                   StringRef InFile) {
     82   std::string Sysroot;
     83   std::string OutputFile;
     84   raw_ostream *OS = 0;
     85   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
     86     return 0;
     87 
     88   if (!CI.getFrontendOpts().RelocatablePCH)
     89     Sysroot.clear();
     90   return new PCHGenerator(CI.getPreprocessor(), OutputFile, 0, Sysroot, OS);
     91 }
     92 
     93 bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
     94                                                     StringRef InFile,
     95                                                     std::string &Sysroot,
     96                                                     std::string &OutputFile,
     97                                                     raw_ostream *&OS) {
     98   Sysroot = CI.getHeaderSearchOpts().Sysroot;
     99   if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
    100     CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
    101     return true;
    102   }
    103 
    104   // We use createOutputFile here because this is exposed via libclang, and we
    105   // must disable the RemoveFileOnSignal behavior.
    106   // We use a temporary to avoid race conditions.
    107   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
    108                            /*RemoveFileOnSignal=*/false, InFile,
    109                            /*Extension=*/"", /*useTemporary=*/true);
    110   if (!OS)
    111     return true;
    112 
    113   OutputFile = CI.getFrontendOpts().OutputFile;
    114   return false;
    115 }
    116 
    117 ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
    118                                                      StringRef InFile) {
    119   std::string Sysroot;
    120   std::string OutputFile;
    121   raw_ostream *OS = 0;
    122   if (ComputeASTConsumerArguments(CI, InFile, Sysroot, OutputFile, OS))
    123     return 0;
    124 
    125   return new PCHGenerator(CI.getPreprocessor(), OutputFile, Module,
    126                           Sysroot, OS);
    127 }
    128 
    129 /// \brief Collect the set of header includes needed to construct the given
    130 /// module.
    131 ///
    132 /// \param Module The module we're collecting includes from.
    133 ///
    134 /// \param Includes Will be augmented with the set of #includes or #imports
    135 /// needed to load all of the named headers.
    136 static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
    137                                         FileManager &FileMgr,
    138                                         ModuleMap &ModMap,
    139                                         clang::Module *Module,
    140                                         SmallString<256> &Includes) {
    141   // Don't collect any headers for unavailable modules.
    142   if (!Module->isAvailable())
    143     return;
    144 
    145   // Add includes for each of these headers.
    146   for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
    147     if (LangOpts.ObjC1)
    148       Includes += "#import \"";
    149     else
    150       Includes += "#include \"";
    151     Includes += Module->Headers[I]->getName();
    152     Includes += "\"\n";
    153   }
    154 
    155   if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
    156     if (Module->Parent) {
    157       // Include the umbrella header for submodules.
    158       if (LangOpts.ObjC1)
    159         Includes += "#import \"";
    160       else
    161         Includes += "#include \"";
    162       Includes += UmbrellaHeader->getName();
    163       Includes += "\"\n";
    164     }
    165   } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
    166     // Add all of the headers we find in this subdirectory.
    167     llvm::error_code EC;
    168     SmallString<128> DirNative;
    169     llvm::sys::path::native(UmbrellaDir->getName(), DirNative);
    170     for (llvm::sys::fs::recursive_directory_iterator Dir(DirNative.str(), EC),
    171                                                      DirEnd;
    172          Dir != DirEnd && !EC; Dir.increment(EC)) {
    173       // Check whether this entry has an extension typically associated with
    174       // headers.
    175       if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->path()))
    176           .Cases(".h", ".H", ".hh", ".hpp", true)
    177           .Default(false))
    178         continue;
    179 
    180       // If this header is marked 'unavailable' in this module, don't include
    181       // it.
    182       if (const FileEntry *Header = FileMgr.getFile(Dir->path()))
    183         if (ModMap.isHeaderInUnavailableModule(Header))
    184           continue;
    185 
    186       // Include this header umbrella header for submodules.
    187       if (LangOpts.ObjC1)
    188         Includes += "#import \"";
    189       else
    190         Includes += "#include \"";
    191       Includes += Dir->path();
    192       Includes += "\"\n";
    193     }
    194   }
    195 
    196   // Recurse into submodules.
    197   for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
    198                                       SubEnd = Module->submodule_end();
    199        Sub != SubEnd; ++Sub)
    200     collectModuleHeaderIncludes(LangOpts, FileMgr, ModMap, *Sub, Includes);
    201 }
    202 
    203 bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
    204                                                  StringRef Filename) {
    205   // Find the module map file.
    206   const FileEntry *ModuleMap = CI.getFileManager().getFile(Filename);
    207   if (!ModuleMap)  {
    208     CI.getDiagnostics().Report(diag::err_module_map_not_found)
    209       << Filename;
    210     return false;
    211   }
    212 
    213   // Parse the module map file.
    214   HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
    215   if (HS.loadModuleMapFile(ModuleMap))
    216     return false;
    217 
    218   if (CI.getLangOpts().CurrentModule.empty()) {
    219     CI.getDiagnostics().Report(diag::err_missing_module_name);
    220 
    221     // FIXME: Eventually, we could consider asking whether there was just
    222     // a single module described in the module map, and use that as a
    223     // default. Then it would be fairly trivial to just "compile" a module
    224     // map with a single module (the common case).
    225     return false;
    226   }
    227 
    228   // Dig out the module definition.
    229   Module = HS.lookupModule(CI.getLangOpts().CurrentModule,
    230                            /*AllowSearch=*/false);
    231   if (!Module) {
    232     CI.getDiagnostics().Report(diag::err_missing_module)
    233       << CI.getLangOpts().CurrentModule << Filename;
    234 
    235     return false;
    236   }
    237 
    238   // Check whether we can build this module at all.
    239   StringRef Feature;
    240   if (!Module->isAvailable(CI.getLangOpts(), CI.getTarget(), Feature)) {
    241     CI.getDiagnostics().Report(diag::err_module_unavailable)
    242       << Module->getFullModuleName()
    243       << Feature;
    244 
    245     return false;
    246   }
    247 
    248   // Do we have an umbrella header for this module?
    249   const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader();
    250 
    251   // Collect the set of #includes we need to build the module.
    252   SmallString<256> HeaderContents;
    253   collectModuleHeaderIncludes(CI.getLangOpts(), CI.getFileManager(),
    254     CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
    255     Module, HeaderContents);
    256   if (UmbrellaHeader && HeaderContents.empty()) {
    257     // Simple case: we have an umbrella header and there are no additional
    258     // includes, we can just parse the umbrella header directly.
    259     setCurrentInput(FrontendInputFile(UmbrellaHeader->getName(),
    260                                       getCurrentFileKind(),
    261                                       Module->IsSystem));
    262     return true;
    263   }
    264 
    265   FileManager &FileMgr = CI.getFileManager();
    266   SmallString<128> HeaderName;
    267   time_t ModTime;
    268   if (UmbrellaHeader) {
    269     // Read in the umbrella header.
    270     // FIXME: Go through the source manager; the umbrella header may have
    271     // been overridden.
    272     std::string ErrorStr;
    273     llvm::MemoryBuffer *UmbrellaContents
    274       = FileMgr.getBufferForFile(UmbrellaHeader, &ErrorStr);
    275     if (!UmbrellaContents) {
    276       CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
    277         << UmbrellaHeader->getName() << ErrorStr;
    278       return false;
    279     }
    280 
    281     // Combine the contents of the umbrella header with the automatically-
    282     // generated includes.
    283     SmallString<256> OldContents = HeaderContents;
    284     HeaderContents = UmbrellaContents->getBuffer();
    285     HeaderContents += "\n\n";
    286     HeaderContents += "/* Module includes */\n";
    287     HeaderContents += OldContents;
    288 
    289     // Pretend that we're parsing the umbrella header.
    290     HeaderName = UmbrellaHeader->getName();
    291     ModTime = UmbrellaHeader->getModificationTime();
    292 
    293     delete UmbrellaContents;
    294   } else {
    295     // Pick an innocuous-sounding name for the umbrella header.
    296     HeaderName = Module->Name + ".h";
    297     if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
    298                         /*CacheFailure=*/false)) {
    299       // Try again!
    300       HeaderName = Module->Name + "-module.h";
    301       if (FileMgr.getFile(HeaderName, /*OpenFile=*/false,
    302                           /*CacheFailure=*/false)) {
    303         // Pick something ridiculous and go with it.
    304         HeaderName = Module->Name + "-module.hmod";
    305       }
    306     }
    307     ModTime = time(0);
    308   }
    309 
    310   // Remap the contents of the header name we're using to our synthesized
    311   // buffer.
    312   const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName,
    313                                                        HeaderContents.size(),
    314                                                        ModTime);
    315   llvm::MemoryBuffer *HeaderContentsBuf
    316     = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
    317   CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);
    318   setCurrentInput(FrontendInputFile(HeaderName, getCurrentFileKind(),
    319                                     Module->IsSystem));
    320   return true;
    321 }
    322 
    323 bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
    324                                                        StringRef InFile,
    325                                                        std::string &Sysroot,
    326                                                        std::string &OutputFile,
    327                                                        raw_ostream *&OS) {
    328   // If no output file was provided, figure out where this module would go
    329   // in the module cache.
    330   if (CI.getFrontendOpts().OutputFile.empty()) {
    331     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
    332     SmallString<256> ModuleFileName(HS.getModuleCachePath());
    333     llvm::sys::path::append(ModuleFileName,
    334                             CI.getLangOpts().CurrentModule + ".pcm");
    335     CI.getFrontendOpts().OutputFile = ModuleFileName.str();
    336   }
    337 
    338   // We use createOutputFile here because this is exposed via libclang, and we
    339   // must disable the RemoveFileOnSignal behavior.
    340   // We use a temporary to avoid race conditions.
    341   OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
    342                            /*RemoveFileOnSignal=*/false, InFile,
    343                            /*Extension=*/"", /*useTemporary=*/true,
    344                            /*CreateMissingDirectories=*/true);
    345   if (!OS)
    346     return true;
    347 
    348   OutputFile = CI.getFrontendOpts().OutputFile;
    349   return false;
    350 }
    351 
    352 ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
    353                                                  StringRef InFile) {
    354   return new ASTConsumer();
    355 }
    356 
    357 //===----------------------------------------------------------------------===//
    358 // Preprocessor Actions
    359 //===----------------------------------------------------------------------===//
    360 
    361 void DumpRawTokensAction::ExecuteAction() {
    362   Preprocessor &PP = getCompilerInstance().getPreprocessor();
    363   SourceManager &SM = PP.getSourceManager();
    364 
    365   // Start lexing the specified input file.
    366   const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
    367   Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
    368   RawLex.SetKeepWhitespaceMode(true);
    369 
    370   Token RawTok;
    371   RawLex.LexFromRawLexer(RawTok);
    372   while (RawTok.isNot(tok::eof)) {
    373     PP.DumpToken(RawTok, true);
    374     llvm::errs() << "\n";
    375     RawLex.LexFromRawLexer(RawTok);
    376   }
    377 }
    378 
    379 void DumpTokensAction::ExecuteAction() {
    380   Preprocessor &PP = getCompilerInstance().getPreprocessor();
    381   // Start preprocessing the specified input file.
    382   Token Tok;
    383   PP.EnterMainSourceFile();
    384   do {
    385     PP.Lex(Tok);
    386     PP.DumpToken(Tok, true);
    387     llvm::errs() << "\n";
    388   } while (Tok.isNot(tok::eof));
    389 }
    390 
    391 void GeneratePTHAction::ExecuteAction() {
    392   CompilerInstance &CI = getCompilerInstance();
    393   if (CI.getFrontendOpts().OutputFile.empty() ||
    394       CI.getFrontendOpts().OutputFile == "-") {
    395     // FIXME: Don't fail this way.
    396     // FIXME: Verify that we can actually seek in the given file.
    397     llvm::report_fatal_error("PTH requires a seekable file for output!");
    398   }
    399   llvm::raw_fd_ostream *OS =
    400     CI.createDefaultOutputFile(true, getCurrentFile());
    401   if (!OS) return;
    402 
    403   CacheTokens(CI.getPreprocessor(), OS);
    404 }
    405 
    406 void PreprocessOnlyAction::ExecuteAction() {
    407   Preprocessor &PP = getCompilerInstance().getPreprocessor();
    408 
    409   // Ignore unknown pragmas.
    410   PP.AddPragmaHandler(new EmptyPragmaHandler());
    411 
    412   Token Tok;
    413   // Start parsing the specified input file.
    414   PP.EnterMainSourceFile();
    415   do {
    416     PP.Lex(Tok);
    417   } while (Tok.isNot(tok::eof));
    418 }
    419 
    420 void PrintPreprocessedAction::ExecuteAction() {
    421   CompilerInstance &CI = getCompilerInstance();
    422   // Output file may need to be set to 'Binary', to avoid converting Unix style
    423   // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
    424   //
    425   // Look to see what type of line endings the file uses. If there's a
    426   // CRLF, then we won't open the file up in binary mode. If there is
    427   // just an LF or CR, then we will open the file up in binary mode.
    428   // In this fashion, the output format should match the input format, unless
    429   // the input format has inconsistent line endings.
    430   //
    431   // This should be a relatively fast operation since most files won't have
    432   // all of their source code on a single line. However, that is still a
    433   // concern, so if we scan for too long, we'll just assume the file should
    434   // be opened in binary mode.
    435   bool BinaryMode = true;
    436   bool InvalidFile = false;
    437   const SourceManager& SM = CI.getSourceManager();
    438   const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
    439                                                      &InvalidFile);
    440   if (!InvalidFile) {
    441     const char *cur = Buffer->getBufferStart();
    442     const char *end = Buffer->getBufferEnd();
    443     const char *next = (cur != end) ? cur + 1 : end;
    444 
    445     // Limit ourselves to only scanning 256 characters into the source
    446     // file.  This is mostly a sanity check in case the file has no
    447     // newlines whatsoever.
    448     if (end - cur > 256) end = cur + 256;
    449 
    450     while (next < end) {
    451       if (*cur == 0x0D) {  // CR
    452         if (*next == 0x0A)  // CRLF
    453           BinaryMode = false;
    454 
    455         break;
    456       } else if (*cur == 0x0A)  // LF
    457         break;
    458 
    459       ++cur, ++next;
    460     }
    461   }
    462 
    463   raw_ostream *OS = CI.createDefaultOutputFile(BinaryMode, getCurrentFile());
    464   if (!OS) return;
    465 
    466   DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
    467                            CI.getPreprocessorOutputOpts());
    468 }
    469 
    470 void PrintPreambleAction::ExecuteAction() {
    471   switch (getCurrentFileKind()) {
    472   case IK_C:
    473   case IK_CXX:
    474   case IK_ObjC:
    475   case IK_ObjCXX:
    476   case IK_OpenCL:
    477   case IK_CUDA:
    478     break;
    479 
    480   case IK_None:
    481   case IK_Asm:
    482   case IK_PreprocessedC:
    483   case IK_PreprocessedCXX:
    484   case IK_PreprocessedObjC:
    485   case IK_PreprocessedObjCXX:
    486   case IK_AST:
    487   case IK_LLVM_IR:
    488     // We can't do anything with these.
    489     return;
    490   }
    491 
    492   CompilerInstance &CI = getCompilerInstance();
    493   llvm::MemoryBuffer *Buffer
    494       = CI.getFileManager().getBufferForFile(getCurrentFile());
    495   if (Buffer) {
    496     unsigned Preamble = Lexer::ComputePreamble(Buffer, CI.getLangOpts()).first;
    497     llvm::outs().write(Buffer->getBufferStart(), Preamble);
    498     delete Buffer;
    499   }
    500 }
    501