DependencyFile.cpp revision 249423
1//===--- DependencyFile.cpp - Generate dependency file --------------------===// 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// This code generates dependency files. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Frontend/Utils.h" 15#include "clang/Basic/FileManager.h" 16#include "clang/Basic/SourceManager.h" 17#include "clang/Frontend/DependencyOutputOptions.h" 18#include "clang/Frontend/FrontendDiagnostic.h" 19#include "clang/Lex/DirectoryLookup.h" 20#include "clang/Lex/LexDiagnostic.h" 21#include "clang/Lex/PPCallbacks.h" 22#include "clang/Lex/Preprocessor.h" 23#include "llvm/ADT/StringSet.h" 24#include "llvm/Support/Path.h" 25#include "llvm/Support/raw_ostream.h" 26 27using namespace clang; 28 29namespace { 30class DependencyFileCallback : public PPCallbacks { 31 std::vector<std::string> Files; 32 llvm::StringSet<> FilesSet; 33 const Preprocessor *PP; 34 std::string OutputFile; 35 std::vector<std::string> Targets; 36 bool IncludeSystemHeaders; 37 bool PhonyTarget; 38 bool AddMissingHeaderDeps; 39 bool SeenMissingHeader; 40private: 41 bool FileMatchesDepCriteria(const char *Filename, 42 SrcMgr::CharacteristicKind FileType); 43 void AddFilename(StringRef Filename); 44 void OutputDependencyFile(); 45 46public: 47 DependencyFileCallback(const Preprocessor *_PP, 48 const DependencyOutputOptions &Opts) 49 : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets), 50 IncludeSystemHeaders(Opts.IncludeSystemHeaders), 51 PhonyTarget(Opts.UsePhonyTargets), 52 AddMissingHeaderDeps(Opts.AddMissingHeaderDeps), 53 SeenMissingHeader(false) {} 54 55 virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason, 56 SrcMgr::CharacteristicKind FileType, 57 FileID PrevFID); 58 virtual void InclusionDirective(SourceLocation HashLoc, 59 const Token &IncludeTok, 60 StringRef FileName, 61 bool IsAngled, 62 CharSourceRange FilenameRange, 63 const FileEntry *File, 64 StringRef SearchPath, 65 StringRef RelativePath, 66 const Module *Imported); 67 68 virtual void EndOfMainFile() { 69 OutputDependencyFile(); 70 } 71}; 72} 73 74void clang::AttachDependencyFileGen(Preprocessor &PP, 75 const DependencyOutputOptions &Opts) { 76 if (Opts.Targets.empty()) { 77 PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT); 78 return; 79 } 80 81 // Disable the "file not found" diagnostic if the -MG option was given. 82 if (Opts.AddMissingHeaderDeps) 83 PP.SetSuppressIncludeNotFoundError(true); 84 85 PP.addPPCallbacks(new DependencyFileCallback(&PP, Opts)); 86} 87 88/// FileMatchesDepCriteria - Determine whether the given Filename should be 89/// considered as a dependency. 90bool DependencyFileCallback::FileMatchesDepCriteria(const char *Filename, 91 SrcMgr::CharacteristicKind FileType) { 92 if (strcmp("<built-in>", Filename) == 0) 93 return false; 94 95 if (IncludeSystemHeaders) 96 return true; 97 98 return FileType == SrcMgr::C_User; 99} 100 101void DependencyFileCallback::FileChanged(SourceLocation Loc, 102 FileChangeReason Reason, 103 SrcMgr::CharacteristicKind FileType, 104 FileID PrevFID) { 105 if (Reason != PPCallbacks::EnterFile) 106 return; 107 108 // Dependency generation really does want to go all the way to the 109 // file entry for a source location to find out what is depended on. 110 // We do not want #line markers to affect dependency generation! 111 SourceManager &SM = PP->getSourceManager(); 112 113 const FileEntry *FE = 114 SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc))); 115 if (FE == 0) return; 116 117 StringRef Filename = FE->getName(); 118 if (!FileMatchesDepCriteria(Filename.data(), FileType)) 119 return; 120 121 // Remove leading "./" (or ".//" or "././" etc.) 122 while (Filename.size() > 2 && Filename[0] == '.' && 123 llvm::sys::path::is_separator(Filename[1])) { 124 Filename = Filename.substr(1); 125 while (llvm::sys::path::is_separator(Filename[0])) 126 Filename = Filename.substr(1); 127 } 128 129 AddFilename(Filename); 130} 131 132void DependencyFileCallback::InclusionDirective(SourceLocation HashLoc, 133 const Token &IncludeTok, 134 StringRef FileName, 135 bool IsAngled, 136 CharSourceRange FilenameRange, 137 const FileEntry *File, 138 StringRef SearchPath, 139 StringRef RelativePath, 140 const Module *Imported) { 141 if (!File) { 142 if (AddMissingHeaderDeps) 143 AddFilename(FileName); 144 else 145 SeenMissingHeader = true; 146 } 147} 148 149void DependencyFileCallback::AddFilename(StringRef Filename) { 150 if (FilesSet.insert(Filename)) 151 Files.push_back(Filename); 152} 153 154/// PrintFilename - GCC escapes spaces, # and $, but apparently not ' or " or 155/// other scary characters. 156static void PrintFilename(raw_ostream &OS, StringRef Filename) { 157 for (unsigned i = 0, e = Filename.size(); i != e; ++i) { 158 if (Filename[i] == ' ' || Filename[i] == '#') 159 OS << '\\'; 160 else if (Filename[i] == '$') // $ is escaped by $$. 161 OS << '$'; 162 OS << Filename[i]; 163 } 164} 165 166void DependencyFileCallback::OutputDependencyFile() { 167 if (SeenMissingHeader) { 168 llvm::sys::Path(OutputFile).eraseFromDisk(); 169 return; 170 } 171 172 std::string Err; 173 llvm::raw_fd_ostream OS(OutputFile.c_str(), Err); 174 if (!Err.empty()) { 175 PP->getDiagnostics().Report(diag::err_fe_error_opening) 176 << OutputFile << Err; 177 return; 178 } 179 180 // Write out the dependency targets, trying to avoid overly long 181 // lines when possible. We try our best to emit exactly the same 182 // dependency file as GCC (4.2), assuming the included files are the 183 // same. 184 const unsigned MaxColumns = 75; 185 unsigned Columns = 0; 186 187 for (std::vector<std::string>::iterator 188 I = Targets.begin(), E = Targets.end(); I != E; ++I) { 189 unsigned N = I->length(); 190 if (Columns == 0) { 191 Columns += N; 192 } else if (Columns + N + 2 > MaxColumns) { 193 Columns = N + 2; 194 OS << " \\\n "; 195 } else { 196 Columns += N + 1; 197 OS << ' '; 198 } 199 // Targets already quoted as needed. 200 OS << *I; 201 } 202 203 OS << ':'; 204 Columns += 1; 205 206 // Now add each dependency in the order it was seen, but avoiding 207 // duplicates. 208 for (std::vector<std::string>::iterator I = Files.begin(), 209 E = Files.end(); I != E; ++I) { 210 // Start a new line if this would exceed the column limit. Make 211 // sure to leave space for a trailing " \" in case we need to 212 // break the line on the next iteration. 213 unsigned N = I->length(); 214 if (Columns + (N + 1) + 2 > MaxColumns) { 215 OS << " \\\n "; 216 Columns = 2; 217 } 218 OS << ' '; 219 PrintFilename(OS, *I); 220 Columns += N + 1; 221 } 222 OS << '\n'; 223 224 // Create phony targets if requested. 225 if (PhonyTarget && !Files.empty()) { 226 // Skip the first entry, this is always the input file itself. 227 for (std::vector<std::string>::iterator I = Files.begin() + 1, 228 E = Files.end(); I != E; ++I) { 229 OS << '\n'; 230 PrintFilename(OS, *I); 231 OS << ":\n"; 232 } 233 } 234} 235 236