1 //===--- HeaderIncludes.cpp - Generate Header Includes --------------------===// 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/Utils.h" 11 #include "clang/Basic/SourceManager.h" 12 #include "clang/Frontend/FrontendDiagnostic.h" 13 #include "clang/Lex/Preprocessor.h" 14 #include "llvm/ADT/SmallString.h" 15 #include "llvm/Support/raw_ostream.h" 16 using namespace clang; 17 18 namespace { 19 class HeaderIncludesCallback : public PPCallbacks { 20 SourceManager &SM; 21 raw_ostream *OutputFile; 22 unsigned CurrentIncludeDepth; 23 bool HasProcessedPredefines; 24 bool OwnsOutputFile; 25 bool ShowAllHeaders; 26 bool ShowDepth; 27 28 public: 29 HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_, 30 raw_ostream *OutputFile_, bool OwnsOutputFile_, 31 bool ShowDepth_) 32 : SM(PP->getSourceManager()), OutputFile(OutputFile_), 33 CurrentIncludeDepth(0), HasProcessedPredefines(false), 34 OwnsOutputFile(OwnsOutputFile_), ShowAllHeaders(ShowAllHeaders_), 35 ShowDepth(ShowDepth_) {} 36 37 ~HeaderIncludesCallback() { 38 if (OwnsOutputFile) 39 delete OutputFile; 40 } 41 42 virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason, 43 SrcMgr::CharacteristicKind FileType, 44 FileID PrevFID); 45 }; 46 } 47 48 void clang::AttachHeaderIncludeGen(Preprocessor &PP, bool ShowAllHeaders, 49 StringRef OutputPath, bool ShowDepth) { 50 raw_ostream *OutputFile = &llvm::errs(); 51 bool OwnsOutputFile = false; 52 53 // Open the output file, if used. 54 if (!OutputPath.empty()) { 55 std::string Error; 56 llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream( 57 OutputPath.str().c_str(), Error, llvm::raw_fd_ostream::F_Append); 58 if (!Error.empty()) { 59 PP.getDiagnostics().Report( 60 clang::diag::warn_fe_cc_print_header_failure) << Error; 61 delete OS; 62 } else { 63 OS->SetUnbuffered(); 64 OS->SetUseAtomicWrites(true); 65 OutputFile = OS; 66 OwnsOutputFile = true; 67 } 68 } 69 70 PP.addPPCallbacks(new HeaderIncludesCallback(&PP, ShowAllHeaders, 71 OutputFile, OwnsOutputFile, 72 ShowDepth)); 73 } 74 75 void HeaderIncludesCallback::FileChanged(SourceLocation Loc, 76 FileChangeReason Reason, 77 SrcMgr::CharacteristicKind NewFileType, 78 FileID PrevFID) { 79 // Unless we are exiting a #include, make sure to skip ahead to the line the 80 // #include directive was at. 81 PresumedLoc UserLoc = SM.getPresumedLoc(Loc); 82 if (UserLoc.isInvalid()) 83 return; 84 85 // Adjust the current include depth. 86 if (Reason == PPCallbacks::EnterFile) { 87 ++CurrentIncludeDepth; 88 } else if (Reason == PPCallbacks::ExitFile) { 89 if (CurrentIncludeDepth) 90 --CurrentIncludeDepth; 91 92 // We track when we are done with the predefines by watching for the first 93 // place where we drop back to a nesting depth of 1. 94 if (CurrentIncludeDepth == 1 && !HasProcessedPredefines) 95 HasProcessedPredefines = true; 96 97 return; 98 } else 99 return; 100 101 // Show the header if we are (a) past the predefines, or (b) showing all 102 // headers and in the predefines at a depth past the initial file and command 103 // line buffers. 104 bool ShowHeader = (HasProcessedPredefines || 105 (ShowAllHeaders && CurrentIncludeDepth > 2)); 106 107 // Dump the header include information we are past the predefines buffer or 108 // are showing all headers. 109 if (ShowHeader && Reason == PPCallbacks::EnterFile) { 110 // Write to a temporary string to avoid unnecessary flushing on errs(). 111 SmallString<512> Filename(UserLoc.getFilename()); 112 Lexer::Stringify(Filename); 113 114 SmallString<256> Msg; 115 if (ShowDepth) { 116 // The main source file is at depth 1, so skip one dot. 117 for (unsigned i = 1; i != CurrentIncludeDepth; ++i) 118 Msg += '.'; 119 Msg += ' '; 120 } 121 Msg += Filename; 122 Msg += '\n'; 123 124 OutputFile->write(Msg.data(), Msg.size()); 125 } 126 } 127