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 const std::vector<std::string> &ExtraHeaders; 23 unsigned CurrentIncludeDepth; 24 bool HasProcessedPredefines; 25 bool OwnsOutputFile; 26 bool ShowAllHeaders; 27 bool ShowDepth; 28 bool MSStyle; 29 bool PrintedExtraHeaders; 30 31 public: 32 HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_, 33 raw_ostream *OutputFile_, 34 const std::vector<std::string> &ExtraHeaders, 35 bool OwnsOutputFile_, bool ShowDepth_, bool MSStyle_) 36 : SM(PP->getSourceManager()), OutputFile(OutputFile_), 37 ExtraHeaders(ExtraHeaders), CurrentIncludeDepth(0), 38 HasProcessedPredefines(false), OwnsOutputFile(OwnsOutputFile_), 39 ShowAllHeaders(ShowAllHeaders_), ShowDepth(ShowDepth_), 40 MSStyle(MSStyle_), PrintedExtraHeaders(false) {} 41 42 ~HeaderIncludesCallback() override { 43 if (OwnsOutputFile) 44 delete OutputFile; 45 } 46 47 void FileChanged(SourceLocation Loc, FileChangeReason Reason, 48 SrcMgr::CharacteristicKind FileType, 49 FileID PrevFID) override; 50 }; 51 } 52 53 static void PrintHeaderInfo(raw_ostream *OutputFile, const char* Filename, 54 bool ShowDepth, unsigned CurrentIncludeDepth, 55 bool MSStyle) { 56 // Write to a temporary string to avoid unnecessary flushing on errs(). 57 SmallString<512> Pathname(Filename); 58 if (!MSStyle) 59 Lexer::Stringify(Pathname); 60 61 SmallString<256> Msg; 62 if (MSStyle) 63 Msg += "Note: including file:"; 64 65 if (ShowDepth) { 66 // The main source file is at depth 1, so skip one dot. 67 for (unsigned i = 1; i != CurrentIncludeDepth; ++i) 68 Msg += MSStyle ? ' ' : '.'; 69 70 if (!MSStyle) 71 Msg += ' '; 72 } 73 Msg += Pathname; 74 Msg += '\n'; 75 76 OutputFile->write(Msg.data(), Msg.size()); 77 OutputFile->flush(); 78 } 79 80 void clang::AttachHeaderIncludeGen(Preprocessor &PP, 81 const std::vector<std::string> &ExtraHeaders, 82 bool ShowAllHeaders, 83 StringRef OutputPath, bool ShowDepth, 84 bool MSStyle) { 85 raw_ostream *OutputFile = MSStyle ? &llvm::outs() : &llvm::errs(); 86 bool OwnsOutputFile = false; 87 88 // Open the output file, if used. 89 if (!OutputPath.empty()) { 90 std::error_code EC; 91 llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream( 92 OutputPath.str(), EC, llvm::sys::fs::F_Append | llvm::sys::fs::F_Text); 93 if (EC) { 94 PP.getDiagnostics().Report(clang::diag::warn_fe_cc_print_header_failure) 95 << EC.message(); 96 delete OS; 97 } else { 98 OS->SetUnbuffered(); 99 OutputFile = OS; 100 OwnsOutputFile = true; 101 } 102 } 103 104 PP.addPPCallbacks(llvm::make_unique<HeaderIncludesCallback>( 105 &PP, ShowAllHeaders, OutputFile, ExtraHeaders, OwnsOutputFile, ShowDepth, 106 MSStyle)); 107 } 108 109 void HeaderIncludesCallback::FileChanged(SourceLocation Loc, 110 FileChangeReason Reason, 111 SrcMgr::CharacteristicKind NewFileType, 112 FileID PrevFID) { 113 if (!PrintedExtraHeaders) { 114 // Print header info for extra headers, pretending they were discovered by 115 // the regular preprocessor. The primary use case is to support proper 116 // generation of Make / Ninja file dependencies for implicit includes, such 117 // as sanitizer blacklists. It's only important for cl.exe compatibility, 118 // the GNU way to generate rules is -M / -MM / -MD / -MMD. 119 for (auto Header : ExtraHeaders) 120 PrintHeaderInfo(OutputFile, Header.c_str(), ShowDepth, 2, MSStyle); 121 PrintedExtraHeaders = true; 122 } 123 124 // Unless we are exiting a #include, make sure to skip ahead to the line the 125 // #include directive was at. 126 PresumedLoc UserLoc = SM.getPresumedLoc(Loc); 127 if (UserLoc.isInvalid()) 128 return; 129 130 // Adjust the current include depth. 131 if (Reason == PPCallbacks::EnterFile) { 132 ++CurrentIncludeDepth; 133 } else if (Reason == PPCallbacks::ExitFile) { 134 if (CurrentIncludeDepth) 135 --CurrentIncludeDepth; 136 137 // We track when we are done with the predefines by watching for the first 138 // place where we drop back to a nesting depth of 1. 139 if (CurrentIncludeDepth == 1 && !HasProcessedPredefines) 140 HasProcessedPredefines = true; 141 142 return; 143 } else 144 return; 145 146 // Show the header if we are (a) past the predefines, or (b) showing all 147 // headers and in the predefines at a depth past the initial file and command 148 // line buffers. 149 bool ShowHeader = (HasProcessedPredefines || 150 (ShowAllHeaders && CurrentIncludeDepth > 2)); 151 unsigned IncludeDepth = CurrentIncludeDepth; 152 if (!HasProcessedPredefines) 153 --IncludeDepth; // Ignore indent from <built-in>. 154 155 // Dump the header include information we are past the predefines buffer or 156 // are showing all headers and this isn't the magic implicit <command line> 157 // header. 158 // FIXME: Identify headers in a more robust way than comparing their name to 159 // "<command line>" and "<built-in>" in a bunch of places. 160 if (ShowHeader && Reason == PPCallbacks::EnterFile && 161 UserLoc.getFilename() != StringRef("<command line>")) { 162 PrintHeaderInfo(OutputFile, UserLoc.getFilename(), ShowDepth, IncludeDepth, 163 MSStyle); 164 } 165 } 166