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) \ 39 static constexpr StringLiteral NAME##_init[] = VALUE; \ 40 static constexpr ArrayRef<StringLiteral> NAME(NAME##_init, \ 41 std::size(NAME##_init) - 1); 42 #include "Options.inc" 43 #undef PREFIX 44 45 // Create table mapping all options defined in Options.td 46 static constexpr OptTable::Info optInfo[] = { 47 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12) \ 48 {X1, X2, X10, X11, OPT_##ID, Option::KIND##Class, \ 49 X9, X8, OPT_##GROUP, OPT_##ALIAS, X7, X12}, 50 #include "Options.inc" 51 #undef OPTION 52 }; 53 54 MachOOptTable::MachOOptTable() : GenericOptTable(optInfo) {} 55 56 // Set color diagnostics according to --color-diagnostics={auto,always,never} 57 // or --no-color-diagnostics flags. 58 static void handleColorDiagnostics(InputArgList &args) { 59 const Arg *arg = 60 args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq, 61 OPT_no_color_diagnostics); 62 if (!arg) 63 return; 64 if (arg->getOption().getID() == OPT_color_diagnostics) { 65 lld::errs().enable_colors(true); 66 } else if (arg->getOption().getID() == OPT_no_color_diagnostics) { 67 lld::errs().enable_colors(false); 68 } else { 69 StringRef s = arg->getValue(); 70 if (s == "always") 71 lld::errs().enable_colors(true); 72 else if (s == "never") 73 lld::errs().enable_colors(false); 74 else if (s != "auto") 75 error("unknown option: --color-diagnostics=" + s); 76 } 77 } 78 79 InputArgList MachOOptTable::parse(ArrayRef<const char *> argv) { 80 // Make InputArgList from string vectors. 81 unsigned missingIndex; 82 unsigned missingCount; 83 SmallVector<const char *, 256> vec(argv.data(), argv.data() + argv.size()); 84 85 // Expand response files (arguments in the form of @<filename>) 86 // and then parse the argument again. 87 cl::ExpandResponseFiles(saver(), cl::TokenizeGNUCommandLine, vec); 88 InputArgList args = ParseArgs(vec, missingIndex, missingCount); 89 90 // Handle -fatal_warnings early since it converts missing argument warnings 91 // to errors. 92 errorHandler().fatalWarnings = args.hasArg(OPT_fatal_warnings); 93 errorHandler().suppressWarnings = args.hasArg(OPT_w); 94 95 if (missingCount) 96 error(Twine(args.getArgString(missingIndex)) + ": missing argument"); 97 98 handleColorDiagnostics(args); 99 100 for (const Arg *arg : args.filtered(OPT_UNKNOWN)) { 101 std::string nearest; 102 if (findNearest(arg->getAsString(args), nearest) > 1) 103 error("unknown argument '" + arg->getAsString(args) + "'"); 104 else 105 error("unknown argument '" + arg->getAsString(args) + 106 "', did you mean '" + nearest + "'"); 107 } 108 return args; 109 } 110 111 void MachOOptTable::printHelp(const char *argv0, bool showHidden) const { 112 OptTable::printHelp(lld::outs(), 113 (std::string(argv0) + " [options] file...").c_str(), 114 "LLVM Linker", showHidden); 115 lld::outs() << "\n"; 116 } 117 118 static std::string rewritePath(StringRef s) { 119 if (fs::exists(s)) 120 return relativeToRoot(s); 121 return std::string(s); 122 } 123 124 static std::string rewriteInputPath(StringRef s) { 125 // Don't bother rewriting "absolute" paths that are actually under the 126 // syslibroot; simply rewriting the syslibroot is sufficient. 127 if (rerootPath(s) == s && fs::exists(s)) 128 return relativeToRoot(s); 129 return std::string(s); 130 } 131 132 // Reconstructs command line arguments so that so that you can re-run 133 // the same command with the same inputs. This is for --reproduce. 134 std::string macho::createResponseFile(const InputArgList &args) { 135 SmallString<0> data; 136 raw_svector_ostream os(data); 137 138 // Copy the command line to the output while rewriting paths. 139 for (const Arg *arg : args) { 140 switch (arg->getOption().getID()) { 141 case OPT_reproduce: 142 break; 143 case OPT_INPUT: 144 os << quote(rewriteInputPath(arg->getValue())) << "\n"; 145 break; 146 case OPT_o: 147 os << "-o " << quote(path::filename(arg->getValue())) << "\n"; 148 break; 149 case OPT_filelist: 150 if (std::optional<MemoryBufferRef> buffer = readFile(arg->getValue())) 151 for (StringRef path : args::getLines(*buffer)) 152 os << quote(rewriteInputPath(path)) << "\n"; 153 break; 154 case OPT_force_load: 155 case OPT_weak_library: 156 case OPT_load_hidden: 157 os << arg->getSpelling() << " " 158 << quote(rewriteInputPath(arg->getValue())) << "\n"; 159 break; 160 case OPT_F: 161 case OPT_L: 162 case OPT_bundle_loader: 163 case OPT_exported_symbols_list: 164 case OPT_order_file: 165 case OPT_syslibroot: 166 case OPT_unexported_symbols_list: 167 os << arg->getSpelling() << " " << quote(rewritePath(arg->getValue())) 168 << "\n"; 169 break; 170 case OPT_sectcreate: 171 os << arg->getSpelling() << " " << quote(arg->getValue(0)) << " " 172 << quote(arg->getValue(1)) << " " 173 << quote(rewritePath(arg->getValue(2))) << "\n"; 174 break; 175 default: 176 os << toString(*arg) << "\n"; 177 } 178 } 179 return std::string(data.str()); 180 } 181 182 static void searchedDylib(const Twine &path, bool found) { 183 if (config->printDylibSearch) 184 message("searched " + path + (found ? ", found " : ", not found")); 185 if (!found) 186 depTracker->logFileNotFound(path); 187 } 188 189 std::optional<StringRef> macho::resolveDylibPath(StringRef dylibPath) { 190 // TODO: if a tbd and dylib are both present, we should check to make sure 191 // they are consistent. 192 SmallString<261> tbdPath = dylibPath; 193 path::replace_extension(tbdPath, ".tbd"); 194 bool tbdExists = fs::exists(tbdPath); 195 searchedDylib(tbdPath, tbdExists); 196 if (tbdExists) 197 return saver().save(tbdPath.str()); 198 199 bool dylibExists = fs::exists(dylibPath); 200 searchedDylib(dylibPath, dylibExists); 201 if (dylibExists) 202 return saver().save(dylibPath); 203 return {}; 204 } 205 206 // It's not uncommon to have multiple attempts to load a single dylib, 207 // especially if it's a commonly re-exported core library. 208 static DenseMap<CachedHashStringRef, DylibFile *> loadedDylibs; 209 210 DylibFile *macho::loadDylib(MemoryBufferRef mbref, DylibFile *umbrella, 211 bool isBundleLoader, bool explicitlyLinked) { 212 CachedHashStringRef path(mbref.getBufferIdentifier()); 213 DylibFile *&file = loadedDylibs[path]; 214 if (file) { 215 if (explicitlyLinked) 216 file->setExplicitlyLinked(); 217 return file; 218 } 219 220 DylibFile *newFile; 221 file_magic magic = identify_magic(mbref.getBuffer()); 222 if (magic == file_magic::tapi_file) { 223 Expected<std::unique_ptr<InterfaceFile>> result = TextAPIReader::get(mbref); 224 if (!result) { 225 error("could not load TAPI file at " + mbref.getBufferIdentifier() + 226 ": " + toString(result.takeError())); 227 return nullptr; 228 } 229 file = 230 make<DylibFile>(**result, umbrella, isBundleLoader, explicitlyLinked); 231 232 // parseReexports() can recursively call loadDylib(). That's fine since 233 // we wrote the DylibFile we just loaded to the loadDylib cache via the 234 // `file` reference. But the recursive load can grow loadDylibs, so the 235 // `file` reference might become invalid after parseReexports() -- so copy 236 // the pointer it refers to before continuing. 237 newFile = file; 238 if (newFile->exportingFile) 239 newFile->parseReexports(**result); 240 } else { 241 assert(magic == file_magic::macho_dynamically_linked_shared_lib || 242 magic == file_magic::macho_dynamically_linked_shared_lib_stub || 243 magic == file_magic::macho_executable || 244 magic == file_magic::macho_bundle); 245 file = make<DylibFile>(mbref, umbrella, isBundleLoader, explicitlyLinked); 246 247 // parseLoadCommands() can also recursively call loadDylib(). See comment 248 // in previous block for why this means we must copy `file` here. 249 newFile = file; 250 if (newFile->exportingFile) 251 newFile->parseLoadCommands(mbref); 252 } 253 return newFile; 254 } 255 256 void macho::resetLoadedDylibs() { loadedDylibs.clear(); } 257 258 std::optional<StringRef> 259 macho::findPathCombination(const Twine &name, 260 const std::vector<StringRef> &roots, 261 ArrayRef<StringRef> extensions) { 262 SmallString<261> base; 263 for (StringRef dir : roots) { 264 base = dir; 265 path::append(base, name); 266 for (StringRef ext : extensions) { 267 Twine location = base + ext; 268 bool exists = fs::exists(location); 269 searchedDylib(location, exists); 270 if (exists) 271 return saver().save(location.str()); 272 } 273 } 274 return {}; 275 } 276 277 StringRef macho::rerootPath(StringRef path) { 278 if (!path::is_absolute(path, path::Style::posix) || path.endswith(".o")) 279 return path; 280 281 if (std::optional<StringRef> rerootedPath = 282 findPathCombination(path, config->systemLibraryRoots)) 283 return *rerootedPath; 284 285 return path; 286 } 287 288 uint32_t macho::getModTime(StringRef path) { 289 if (config->zeroModTime) 290 return 0; 291 292 fs::file_status stat; 293 if (!fs::status(path, stat)) 294 if (fs::exists(stat)) 295 return toTimeT(stat.getLastModificationTime()); 296 297 warn("failed to get modification time of " + path); 298 return 0; 299 } 300 301 void macho::printArchiveMemberLoad(StringRef reason, const InputFile *f) { 302 if (config->printEachFile) 303 message(toString(f)); 304 if (config->printWhyLoad) 305 message(reason + " forced load of " + toString(f)); 306 } 307 308 macho::DependencyTracker::DependencyTracker(StringRef path) 309 : path(path), active(!path.empty()) { 310 if (active && fs::exists(path) && !fs::can_write(path)) { 311 warn("Ignoring dependency_info option since specified path is not " 312 "writeable."); 313 active = false; 314 } 315 } 316 317 void macho::DependencyTracker::write(StringRef version, 318 const SetVector<InputFile *> &inputs, 319 StringRef output) { 320 if (!active) 321 return; 322 323 std::error_code ec; 324 raw_fd_ostream os(path, ec, fs::OF_None); 325 if (ec) { 326 warn("Error writing dependency info to file"); 327 return; 328 } 329 330 auto addDep = [&os](DepOpCode opcode, const StringRef &path) { 331 // XXX: Even though DepOpCode's underlying type is uint8_t, 332 // this cast is still needed because Clang older than 10.x has a bug, 333 // where it doesn't know to cast the enum to its underlying type. 334 // Hence `<< DepOpCode` is ambiguous to it. 335 os << static_cast<uint8_t>(opcode); 336 os << path; 337 os << '\0'; 338 }; 339 340 addDep(DepOpCode::Version, version); 341 342 // Sort the input by its names. 343 std::vector<StringRef> inputNames; 344 inputNames.reserve(inputs.size()); 345 for (InputFile *f : inputs) 346 inputNames.push_back(f->getName()); 347 llvm::sort(inputNames); 348 349 for (const StringRef &in : inputNames) 350 addDep(DepOpCode::Input, in); 351 352 for (const std::string &f : notFounds) 353 addDep(DepOpCode::NotFound, f); 354 355 addDep(DepOpCode::Output, output); 356 } 357