1 //===- DriverUtils.cpp ----------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "Config.h" 10 #include "Driver.h" 11 #include "InputFiles.h" 12 #include "ObjC.h" 13 #include "Target.h" 14 15 #include "lld/Common/Args.h" 16 #include "lld/Common/CommonLinkerContext.h" 17 #include "lld/Common/Reproduce.h" 18 #include "llvm/ADT/CachedHashString.h" 19 #include "llvm/ADT/DenseMap.h" 20 #include "llvm/LTO/LTO.h" 21 #include "llvm/Option/Arg.h" 22 #include "llvm/Option/ArgList.h" 23 #include "llvm/Option/Option.h" 24 #include "llvm/Support/CommandLine.h" 25 #include "llvm/Support/FileSystem.h" 26 #include "llvm/Support/Path.h" 27 #include "llvm/TextAPI/InterfaceFile.h" 28 #include "llvm/TextAPI/TextAPIReader.h" 29 30 using namespace llvm; 31 using namespace llvm::MachO; 32 using namespace llvm::opt; 33 using namespace llvm::sys; 34 using namespace lld; 35 using namespace lld::macho; 36 37 // Create prefix string literals used in Options.td 38 #define PREFIX(NAME, VALUE) const char *NAME[] = VALUE; 39 #include "Options.inc" 40 #undef PREFIX 41 42 // Create table mapping all options defined in Options.td 43 static const OptTable::Info optInfo[] = { 44 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12) \ 45 {X1, X2, X10, X11, OPT_##ID, Option::KIND##Class, \ 46 X9, X8, OPT_##GROUP, OPT_##ALIAS, X7, X12}, 47 #include "Options.inc" 48 #undef OPTION 49 }; 50 51 MachOOptTable::MachOOptTable() : OptTable(optInfo) {} 52 53 // Set color diagnostics according to --color-diagnostics={auto,always,never} 54 // or --no-color-diagnostics flags. 55 static void handleColorDiagnostics(InputArgList &args) { 56 const Arg *arg = 57 args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq, 58 OPT_no_color_diagnostics); 59 if (!arg) 60 return; 61 if (arg->getOption().getID() == OPT_color_diagnostics) { 62 lld::errs().enable_colors(true); 63 } else if (arg->getOption().getID() == OPT_no_color_diagnostics) { 64 lld::errs().enable_colors(false); 65 } else { 66 StringRef s = arg->getValue(); 67 if (s == "always") 68 lld::errs().enable_colors(true); 69 else if (s == "never") 70 lld::errs().enable_colors(false); 71 else if (s != "auto") 72 error("unknown option: --color-diagnostics=" + s); 73 } 74 } 75 76 InputArgList MachOOptTable::parse(ArrayRef<const char *> argv) { 77 // Make InputArgList from string vectors. 78 unsigned missingIndex; 79 unsigned missingCount; 80 SmallVector<const char *, 256> vec(argv.data(), argv.data() + argv.size()); 81 82 // Expand response files (arguments in the form of @<filename>) 83 // and then parse the argument again. 84 cl::ExpandResponseFiles(saver(), cl::TokenizeGNUCommandLine, vec); 85 InputArgList args = ParseArgs(vec, missingIndex, missingCount); 86 87 // Handle -fatal_warnings early since it converts missing argument warnings 88 // to errors. 89 errorHandler().fatalWarnings = args.hasArg(OPT_fatal_warnings); 90 errorHandler().suppressWarnings = args.hasArg(OPT_w); 91 92 if (missingCount) 93 error(Twine(args.getArgString(missingIndex)) + ": missing argument"); 94 95 handleColorDiagnostics(args); 96 97 for (const Arg *arg : args.filtered(OPT_UNKNOWN)) { 98 std::string nearest; 99 if (findNearest(arg->getAsString(args), nearest) > 1) 100 error("unknown argument '" + arg->getAsString(args) + "'"); 101 else 102 error("unknown argument '" + arg->getAsString(args) + 103 "', did you mean '" + nearest + "'"); 104 } 105 return args; 106 } 107 108 void MachOOptTable::printHelp(const char *argv0, bool showHidden) const { 109 OptTable::printHelp(lld::outs(), 110 (std::string(argv0) + " [options] file...").c_str(), 111 "LLVM Linker", showHidden); 112 lld::outs() << "\n"; 113 } 114 115 static std::string rewritePath(StringRef s) { 116 if (fs::exists(s)) 117 return relativeToRoot(s); 118 return std::string(s); 119 } 120 121 static std::string rewriteInputPath(StringRef s) { 122 // Don't bother rewriting "absolute" paths that are actually under the 123 // syslibroot; simply rewriting the syslibroot is sufficient. 124 if (rerootPath(s) == s && fs::exists(s)) 125 return relativeToRoot(s); 126 return std::string(s); 127 } 128 129 // Reconstructs command line arguments so that so that you can re-run 130 // the same command with the same inputs. This is for --reproduce. 131 std::string macho::createResponseFile(const InputArgList &args) { 132 SmallString<0> data; 133 raw_svector_ostream os(data); 134 135 // Copy the command line to the output while rewriting paths. 136 for (const Arg *arg : args) { 137 switch (arg->getOption().getID()) { 138 case OPT_reproduce: 139 break; 140 case OPT_INPUT: 141 os << quote(rewriteInputPath(arg->getValue())) << "\n"; 142 break; 143 case OPT_o: 144 os << "-o " << quote(path::filename(arg->getValue())) << "\n"; 145 break; 146 case OPT_filelist: 147 if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue())) 148 for (StringRef path : args::getLines(*buffer)) 149 os << quote(rewriteInputPath(path)) << "\n"; 150 break; 151 case OPT_force_load: 152 case OPT_weak_library: 153 case OPT_load_hidden: 154 os << arg->getSpelling() << " " 155 << quote(rewriteInputPath(arg->getValue())) << "\n"; 156 break; 157 case OPT_F: 158 case OPT_L: 159 case OPT_bundle_loader: 160 case OPT_exported_symbols_list: 161 case OPT_order_file: 162 case OPT_rpath: 163 case OPT_syslibroot: 164 case OPT_unexported_symbols_list: 165 os << arg->getSpelling() << " " << quote(rewritePath(arg->getValue())) 166 << "\n"; 167 break; 168 case OPT_sectcreate: 169 os << arg->getSpelling() << " " << quote(arg->getValue(0)) << " " 170 << quote(arg->getValue(1)) << " " 171 << quote(rewritePath(arg->getValue(2))) << "\n"; 172 break; 173 default: 174 os << toString(*arg) << "\n"; 175 } 176 } 177 return std::string(data.str()); 178 } 179 180 static void searchedDylib(const Twine &path, bool found) { 181 if (config->printDylibSearch) 182 message("searched " + path + (found ? ", found " : ", not found")); 183 if (!found) 184 depTracker->logFileNotFound(path); 185 } 186 187 Optional<StringRef> macho::resolveDylibPath(StringRef dylibPath) { 188 // TODO: if a tbd and dylib are both present, we should check to make sure 189 // they are consistent. 190 SmallString<261> tbdPath = dylibPath; 191 path::replace_extension(tbdPath, ".tbd"); 192 bool tbdExists = fs::exists(tbdPath); 193 searchedDylib(tbdPath, tbdExists); 194 if (tbdExists) 195 return saver().save(tbdPath.str()); 196 197 bool dylibExists = fs::exists(dylibPath); 198 searchedDylib(dylibPath, dylibExists); 199 if (dylibExists) 200 return saver().save(dylibPath); 201 return {}; 202 } 203 204 // It's not uncommon to have multiple attempts to load a single dylib, 205 // especially if it's a commonly re-exported core library. 206 static DenseMap<CachedHashStringRef, DylibFile *> loadedDylibs; 207 208 DylibFile *macho::loadDylib(MemoryBufferRef mbref, DylibFile *umbrella, 209 bool isBundleLoader, bool explicitlyLinked) { 210 CachedHashStringRef path(mbref.getBufferIdentifier()); 211 DylibFile *&file = loadedDylibs[path]; 212 if (file) { 213 if (explicitlyLinked) 214 file->setExplicitlyLinked(); 215 return file; 216 } 217 218 DylibFile *newFile; 219 file_magic magic = identify_magic(mbref.getBuffer()); 220 if (magic == file_magic::tapi_file) { 221 Expected<std::unique_ptr<InterfaceFile>> result = TextAPIReader::get(mbref); 222 if (!result) { 223 error("could not load TAPI file at " + mbref.getBufferIdentifier() + 224 ": " + toString(result.takeError())); 225 return nullptr; 226 } 227 file = 228 make<DylibFile>(**result, umbrella, isBundleLoader, explicitlyLinked); 229 230 // parseReexports() can recursively call loadDylib(). That's fine since 231 // we wrote the DylibFile we just loaded to the loadDylib cache via the 232 // `file` reference. But the recursive load can grow loadDylibs, so the 233 // `file` reference might become invalid after parseReexports() -- so copy 234 // the pointer it refers to before continuing. 235 newFile = file; 236 if (newFile->exportingFile) 237 newFile->parseReexports(**result); 238 } else { 239 assert(magic == file_magic::macho_dynamically_linked_shared_lib || 240 magic == file_magic::macho_dynamically_linked_shared_lib_stub || 241 magic == file_magic::macho_executable || 242 magic == file_magic::macho_bundle); 243 file = make<DylibFile>(mbref, umbrella, isBundleLoader, explicitlyLinked); 244 245 // parseLoadCommands() can also recursively call loadDylib(). See comment 246 // in previous block for why this means we must copy `file` here. 247 newFile = file; 248 if (newFile->exportingFile) 249 newFile->parseLoadCommands(mbref); 250 } 251 return newFile; 252 } 253 254 void macho::resetLoadedDylibs() { loadedDylibs.clear(); } 255 256 Optional<StringRef> 257 macho::findPathCombination(const Twine &name, 258 const std::vector<StringRef> &roots, 259 ArrayRef<StringRef> extensions) { 260 SmallString<261> base; 261 for (StringRef dir : roots) { 262 base = dir; 263 path::append(base, name); 264 for (StringRef ext : extensions) { 265 Twine location = base + ext; 266 bool exists = fs::exists(location); 267 searchedDylib(location, exists); 268 if (exists) 269 return saver().save(location.str()); 270 } 271 } 272 return {}; 273 } 274 275 StringRef macho::rerootPath(StringRef path) { 276 if (!path::is_absolute(path, path::Style::posix) || path.endswith(".o")) 277 return path; 278 279 if (Optional<StringRef> rerootedPath = 280 findPathCombination(path, config->systemLibraryRoots)) 281 return *rerootedPath; 282 283 return path; 284 } 285 286 uint32_t macho::getModTime(StringRef path) { 287 if (config->zeroModTime) 288 return 0; 289 290 fs::file_status stat; 291 if (!fs::status(path, stat)) 292 if (fs::exists(stat)) 293 return toTimeT(stat.getLastModificationTime()); 294 295 warn("failed to get modification time of " + path); 296 return 0; 297 } 298 299 void macho::printArchiveMemberLoad(StringRef reason, const InputFile *f) { 300 if (config->printEachFile) 301 message(toString(f)); 302 if (config->printWhyLoad) 303 message(reason + " forced load of " + toString(f)); 304 } 305 306 macho::DependencyTracker::DependencyTracker(StringRef path) 307 : path(path), active(!path.empty()) { 308 if (active && fs::exists(path) && !fs::can_write(path)) { 309 warn("Ignoring dependency_info option since specified path is not " 310 "writeable."); 311 active = false; 312 } 313 } 314 315 void macho::DependencyTracker::write(StringRef version, 316 const SetVector<InputFile *> &inputs, 317 StringRef output) { 318 if (!active) 319 return; 320 321 std::error_code ec; 322 raw_fd_ostream os(path, ec, fs::OF_None); 323 if (ec) { 324 warn("Error writing dependency info to file"); 325 return; 326 } 327 328 auto addDep = [&os](DepOpCode opcode, const StringRef &path) { 329 // XXX: Even though DepOpCode's underlying type is uint8_t, 330 // this cast is still needed because Clang older than 10.x has a bug, 331 // where it doesn't know to cast the enum to its underlying type. 332 // Hence `<< DepOpCode` is ambiguous to it. 333 os << static_cast<uint8_t>(opcode); 334 os << path; 335 os << '\0'; 336 }; 337 338 addDep(DepOpCode::Version, version); 339 340 // Sort the input by its names. 341 std::vector<StringRef> inputNames; 342 inputNames.reserve(inputs.size()); 343 for (InputFile *f : inputs) 344 inputNames.push_back(f->getName()); 345 llvm::sort(inputNames); 346 347 for (const StringRef &in : inputNames) 348 addDep(DepOpCode::Input, in); 349 350 for (const std::string &f : notFounds) 351 addDep(DepOpCode::NotFound, f); 352 353 addDep(DepOpCode::Output, output); 354 } 355