1 //===- Driver.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 "Driver.h"
10 #include "Config.h"
11 #include "ICF.h"
12 #include "InputFiles.h"
13 #include "LTO.h"
14 #include "MarkLive.h"
15 #include "ObjC.h"
16 #include "OutputSection.h"
17 #include "OutputSegment.h"
18 #include "SectionPriorities.h"
19 #include "SymbolTable.h"
20 #include "Symbols.h"
21 #include "SyntheticSections.h"
22 #include "Target.h"
23 #include "UnwindInfoSection.h"
24 #include "Writer.h"
25
26 #include "lld/Common/Args.h"
27 #include "lld/Common/CommonLinkerContext.h"
28 #include "lld/Common/ErrorHandler.h"
29 #include "lld/Common/LLVM.h"
30 #include "lld/Common/Memory.h"
31 #include "lld/Common/Reproduce.h"
32 #include "lld/Common/Version.h"
33 #include "llvm/ADT/DenseSet.h"
34 #include "llvm/ADT/StringExtras.h"
35 #include "llvm/ADT/StringRef.h"
36 #include "llvm/BinaryFormat/MachO.h"
37 #include "llvm/BinaryFormat/Magic.h"
38 #include "llvm/CGData/CodeGenDataWriter.h"
39 #include "llvm/Config/llvm-config.h"
40 #include "llvm/LTO/LTO.h"
41 #include "llvm/Object/Archive.h"
42 #include "llvm/Option/ArgList.h"
43 #include "llvm/Support/CommandLine.h"
44 #include "llvm/Support/FileSystem.h"
45 #include "llvm/Support/Parallel.h"
46 #include "llvm/Support/Path.h"
47 #include "llvm/Support/TarWriter.h"
48 #include "llvm/Support/TargetSelect.h"
49 #include "llvm/Support/TimeProfiler.h"
50 #include "llvm/TargetParser/Host.h"
51 #include "llvm/TextAPI/Architecture.h"
52 #include "llvm/TextAPI/PackedVersion.h"
53
54 using namespace llvm;
55 using namespace llvm::MachO;
56 using namespace llvm::object;
57 using namespace llvm::opt;
58 using namespace llvm::sys;
59 using namespace lld;
60 using namespace lld::macho;
61
62 std::unique_ptr<Configuration> macho::config;
63 std::unique_ptr<DependencyTracker> macho::depTracker;
64
getOutputType(const InputArgList & args)65 static HeaderFileType getOutputType(const InputArgList &args) {
66 // TODO: -r, -dylinker, -preload...
67 Arg *outputArg = args.getLastArg(OPT_bundle, OPT_dylib, OPT_execute);
68 if (outputArg == nullptr)
69 return MH_EXECUTE;
70
71 switch (outputArg->getOption().getID()) {
72 case OPT_bundle:
73 return MH_BUNDLE;
74 case OPT_dylib:
75 return MH_DYLIB;
76 case OPT_execute:
77 return MH_EXECUTE;
78 default:
79 llvm_unreachable("internal error");
80 }
81 }
82
83 static DenseMap<CachedHashStringRef, StringRef> resolvedLibraries;
findLibrary(StringRef name)84 static std::optional<StringRef> findLibrary(StringRef name) {
85 CachedHashStringRef key(name);
86 auto entry = resolvedLibraries.find(key);
87 if (entry != resolvedLibraries.end())
88 return entry->second;
89
90 auto doFind = [&] {
91 // Special case for Csu support files required for Mac OS X 10.7 and older
92 // (crt1.o)
93 if (name.ends_with(".o"))
94 return findPathCombination(name, config->librarySearchPaths, {""});
95 if (config->searchDylibsFirst) {
96 if (std::optional<StringRef> path =
97 findPathCombination("lib" + name, config->librarySearchPaths,
98 {".tbd", ".dylib", ".so"}))
99 return path;
100 return findPathCombination("lib" + name, config->librarySearchPaths,
101 {".a"});
102 }
103 return findPathCombination("lib" + name, config->librarySearchPaths,
104 {".tbd", ".dylib", ".so", ".a"});
105 };
106
107 std::optional<StringRef> path = doFind();
108 if (path)
109 resolvedLibraries[key] = *path;
110
111 return path;
112 }
113
114 static DenseMap<CachedHashStringRef, StringRef> resolvedFrameworks;
findFramework(StringRef name)115 static std::optional<StringRef> findFramework(StringRef name) {
116 CachedHashStringRef key(name);
117 auto entry = resolvedFrameworks.find(key);
118 if (entry != resolvedFrameworks.end())
119 return entry->second;
120
121 SmallString<260> symlink;
122 StringRef suffix;
123 std::tie(name, suffix) = name.split(",");
124 for (StringRef dir : config->frameworkSearchPaths) {
125 symlink = dir;
126 path::append(symlink, name + ".framework", name);
127
128 if (!suffix.empty()) {
129 // NOTE: we must resolve the symlink before trying the suffixes, because
130 // there are no symlinks for the suffixed paths.
131 SmallString<260> location;
132 if (!fs::real_path(symlink, location)) {
133 // only append suffix if realpath() succeeds
134 Twine suffixed = location + suffix;
135 if (fs::exists(suffixed))
136 return resolvedFrameworks[key] = saver().save(suffixed.str());
137 }
138 // Suffix lookup failed, fall through to the no-suffix case.
139 }
140
141 if (std::optional<StringRef> path = resolveDylibPath(symlink.str()))
142 return resolvedFrameworks[key] = *path;
143 }
144 return {};
145 }
146
warnIfNotDirectory(StringRef option,StringRef path)147 static bool warnIfNotDirectory(StringRef option, StringRef path) {
148 if (!fs::exists(path)) {
149 warn("directory not found for option -" + option + path);
150 return false;
151 } else if (!fs::is_directory(path)) {
152 warn("option -" + option + path + " references a non-directory path");
153 return false;
154 }
155 return true;
156 }
157
158 static std::vector<StringRef>
getSearchPaths(unsigned optionCode,InputArgList & args,const std::vector<StringRef> & roots,const SmallVector<StringRef,2> & systemPaths)159 getSearchPaths(unsigned optionCode, InputArgList &args,
160 const std::vector<StringRef> &roots,
161 const SmallVector<StringRef, 2> &systemPaths) {
162 std::vector<StringRef> paths;
163 StringRef optionLetter{optionCode == OPT_F ? "F" : "L"};
164 for (StringRef path : args::getStrings(args, optionCode)) {
165 // NOTE: only absolute paths are re-rooted to syslibroot(s)
166 bool found = false;
167 if (path::is_absolute(path, path::Style::posix)) {
168 for (StringRef root : roots) {
169 SmallString<261> buffer(root);
170 path::append(buffer, path);
171 // Do not warn about paths that are computed via the syslib roots
172 if (fs::is_directory(buffer)) {
173 paths.push_back(saver().save(buffer.str()));
174 found = true;
175 }
176 }
177 }
178 if (!found && warnIfNotDirectory(optionLetter, path))
179 paths.push_back(path);
180 }
181
182 // `-Z` suppresses the standard "system" search paths.
183 if (args.hasArg(OPT_Z))
184 return paths;
185
186 for (const StringRef &path : systemPaths) {
187 for (const StringRef &root : roots) {
188 SmallString<261> buffer(root);
189 path::append(buffer, path);
190 if (fs::is_directory(buffer))
191 paths.push_back(saver().save(buffer.str()));
192 }
193 }
194 return paths;
195 }
196
getSystemLibraryRoots(InputArgList & args)197 static std::vector<StringRef> getSystemLibraryRoots(InputArgList &args) {
198 std::vector<StringRef> roots;
199 for (const Arg *arg : args.filtered(OPT_syslibroot))
200 roots.push_back(arg->getValue());
201 // NOTE: the final `-syslibroot` being `/` will ignore all roots
202 if (!roots.empty() && roots.back() == "/")
203 roots.clear();
204 // NOTE: roots can never be empty - add an empty root to simplify the library
205 // and framework search path computation.
206 if (roots.empty())
207 roots.emplace_back("");
208 return roots;
209 }
210
211 static std::vector<StringRef>
getLibrarySearchPaths(InputArgList & args,const std::vector<StringRef> & roots)212 getLibrarySearchPaths(InputArgList &args, const std::vector<StringRef> &roots) {
213 return getSearchPaths(OPT_L, args, roots, {"/usr/lib", "/usr/local/lib"});
214 }
215
216 static std::vector<StringRef>
getFrameworkSearchPaths(InputArgList & args,const std::vector<StringRef> & roots)217 getFrameworkSearchPaths(InputArgList &args,
218 const std::vector<StringRef> &roots) {
219 return getSearchPaths(OPT_F, args, roots,
220 {"/Library/Frameworks", "/System/Library/Frameworks"});
221 }
222
getLTOCachePolicy(InputArgList & args)223 static llvm::CachePruningPolicy getLTOCachePolicy(InputArgList &args) {
224 SmallString<128> ltoPolicy;
225 auto add = [<oPolicy](Twine val) {
226 if (!ltoPolicy.empty())
227 ltoPolicy += ":";
228 val.toVector(ltoPolicy);
229 };
230 for (const Arg *arg :
231 args.filtered(OPT_thinlto_cache_policy_eq, OPT_prune_interval_lto,
232 OPT_prune_after_lto, OPT_max_relative_cache_size_lto)) {
233 switch (arg->getOption().getID()) {
234 case OPT_thinlto_cache_policy_eq:
235 add(arg->getValue());
236 break;
237 case OPT_prune_interval_lto:
238 if (!strcmp("-1", arg->getValue()))
239 add("prune_interval=87600h"); // 10 years
240 else
241 add(Twine("prune_interval=") + arg->getValue() + "s");
242 break;
243 case OPT_prune_after_lto:
244 add(Twine("prune_after=") + arg->getValue() + "s");
245 break;
246 case OPT_max_relative_cache_size_lto:
247 add(Twine("cache_size=") + arg->getValue() + "%");
248 break;
249 }
250 }
251 return CHECK(parseCachePruningPolicy(ltoPolicy), "invalid LTO cache policy");
252 }
253
254 // What caused a given library to be loaded. Only relevant for archives.
255 // Note that this does not tell us *how* we should load the library, i.e.
256 // whether we should do it lazily or eagerly (AKA force loading). The "how" is
257 // decided within addFile().
258 enum class LoadType {
259 CommandLine, // Library was passed as a regular CLI argument
260 CommandLineForce, // Library was passed via `-force_load`
261 LCLinkerOption, // Library was passed via LC_LINKER_OPTIONS
262 };
263
264 struct ArchiveFileInfo {
265 ArchiveFile *file;
266 bool isCommandLineLoad;
267 };
268
269 static DenseMap<StringRef, ArchiveFileInfo> loadedArchives;
270
saveThinArchiveToRepro(ArchiveFile const * file)271 static void saveThinArchiveToRepro(ArchiveFile const *file) {
272 assert(tar && file->getArchive().isThin());
273
274 Error e = Error::success();
275 for (const object::Archive::Child &c : file->getArchive().children(e)) {
276 MemoryBufferRef mb = CHECK(c.getMemoryBufferRef(),
277 toString(file) + ": failed to get buffer");
278 tar->append(relativeToRoot(CHECK(c.getFullName(), file)), mb.getBuffer());
279 }
280 if (e)
281 error(toString(file) +
282 ": Archive::children failed: " + toString(std::move(e)));
283 }
284
addFile(StringRef path,LoadType loadType,bool isLazy=false,bool isExplicit=true,bool isBundleLoader=false,bool isForceHidden=false)285 static InputFile *addFile(StringRef path, LoadType loadType,
286 bool isLazy = false, bool isExplicit = true,
287 bool isBundleLoader = false,
288 bool isForceHidden = false) {
289 std::optional<MemoryBufferRef> buffer = readFile(path);
290 if (!buffer)
291 return nullptr;
292 MemoryBufferRef mbref = *buffer;
293 InputFile *newFile = nullptr;
294
295 file_magic magic = identify_magic(mbref.getBuffer());
296 switch (magic) {
297 case file_magic::archive: {
298 bool isCommandLineLoad = loadType != LoadType::LCLinkerOption;
299 // Avoid loading archives twice. If the archives are being force-loaded,
300 // loading them twice would create duplicate symbol errors. In the
301 // non-force-loading case, this is just a minor performance optimization.
302 // We don't take a reference to cachedFile here because the
303 // loadArchiveMember() call below may recursively call addFile() and
304 // invalidate this reference.
305 auto entry = loadedArchives.find(path);
306
307 ArchiveFile *file;
308 if (entry == loadedArchives.end()) {
309 // No cached archive, we need to create a new one
310 std::unique_ptr<object::Archive> archive = CHECK(
311 object::Archive::create(mbref), path + ": failed to parse archive");
312
313 file = make<ArchiveFile>(std::move(archive), isForceHidden);
314
315 if (tar && file->getArchive().isThin())
316 saveThinArchiveToRepro(file);
317 } else {
318 file = entry->second.file;
319 // Command-line loads take precedence. If file is previously loaded via
320 // command line, or is loaded via LC_LINKER_OPTION and being loaded via
321 // LC_LINKER_OPTION again, using the cached archive is enough.
322 if (entry->second.isCommandLineLoad || !isCommandLineLoad)
323 return file;
324 }
325
326 bool isLCLinkerForceLoad = loadType == LoadType::LCLinkerOption &&
327 config->forceLoadSwift &&
328 path::filename(path).starts_with("libswift");
329 if ((isCommandLineLoad && config->allLoad) ||
330 loadType == LoadType::CommandLineForce || isLCLinkerForceLoad) {
331 if (readFile(path)) {
332 Error e = Error::success();
333 for (const object::Archive::Child &c : file->getArchive().children(e)) {
334 StringRef reason;
335 switch (loadType) {
336 case LoadType::LCLinkerOption:
337 reason = "LC_LINKER_OPTION";
338 break;
339 case LoadType::CommandLineForce:
340 reason = "-force_load";
341 break;
342 case LoadType::CommandLine:
343 reason = "-all_load";
344 break;
345 }
346 if (Error e = file->fetch(c, reason)) {
347 if (config->warnThinArchiveMissingMembers)
348 warn(toString(file) + ": " + reason +
349 " failed to load archive member: " + toString(std::move(e)));
350 else
351 llvm::consumeError(std::move(e));
352 }
353 }
354 if (e)
355 error(toString(file) +
356 ": Archive::children failed: " + toString(std::move(e)));
357 }
358 } else if (isCommandLineLoad && config->forceLoadObjC) {
359 if (file->getArchive().hasSymbolTable()) {
360 for (const object::Archive::Symbol &sym : file->getArchive().symbols())
361 if (sym.getName().starts_with(objc::symbol_names::klass))
362 file->fetch(sym);
363 }
364
365 // TODO: no need to look for ObjC sections for a given archive member if
366 // we already found that it contains an ObjC symbol.
367 if (readFile(path)) {
368 Error e = Error::success();
369 for (const object::Archive::Child &c : file->getArchive().children(e)) {
370 Expected<MemoryBufferRef> mb = c.getMemoryBufferRef();
371 if (!mb) {
372 // We used to create broken repro tarballs that only included those
373 // object files from thin archives that ended up being used.
374 if (config->warnThinArchiveMissingMembers)
375 warn(toString(file) + ": -ObjC failed to open archive member: " +
376 toString(mb.takeError()));
377 else
378 llvm::consumeError(mb.takeError());
379 continue;
380 }
381
382 if (!hasObjCSection(*mb))
383 continue;
384 if (Error e = file->fetch(c, "-ObjC"))
385 error(toString(file) + ": -ObjC failed to load archive member: " +
386 toString(std::move(e)));
387 }
388 if (e)
389 error(toString(file) +
390 ": Archive::children failed: " + toString(std::move(e)));
391 }
392 }
393 file->addLazySymbols();
394 loadedArchives[path] = ArchiveFileInfo{file, isCommandLineLoad};
395 newFile = file;
396 break;
397 }
398 case file_magic::macho_object:
399 newFile = make<ObjFile>(mbref, getModTime(path), "", isLazy);
400 break;
401 case file_magic::macho_dynamically_linked_shared_lib:
402 case file_magic::macho_dynamically_linked_shared_lib_stub:
403 case file_magic::tapi_file:
404 if (DylibFile *dylibFile =
405 loadDylib(mbref, nullptr, /*isBundleLoader=*/false, isExplicit))
406 newFile = dylibFile;
407 break;
408 case file_magic::bitcode:
409 newFile = make<BitcodeFile>(mbref, "", 0, isLazy);
410 break;
411 case file_magic::macho_executable:
412 case file_magic::macho_bundle:
413 // We only allow executable and bundle type here if it is used
414 // as a bundle loader.
415 if (!isBundleLoader)
416 error(path + ": unhandled file type");
417 if (DylibFile *dylibFile = loadDylib(mbref, nullptr, isBundleLoader))
418 newFile = dylibFile;
419 break;
420 default:
421 error(path + ": unhandled file type");
422 }
423 if (newFile && !isa<DylibFile>(newFile)) {
424 if ((isa<ObjFile>(newFile) || isa<BitcodeFile>(newFile)) && newFile->lazy &&
425 config->forceLoadObjC) {
426 for (Symbol *sym : newFile->symbols)
427 if (sym && sym->getName().starts_with(objc::symbol_names::klass)) {
428 extract(*newFile, "-ObjC");
429 break;
430 }
431 if (newFile->lazy && hasObjCSection(mbref))
432 extract(*newFile, "-ObjC");
433 }
434
435 // printArchiveMemberLoad() prints both .a and .o names, so no need to
436 // print the .a name here. Similarly skip lazy files.
437 if (config->printEachFile && magic != file_magic::archive && !isLazy)
438 message(toString(newFile));
439 inputFiles.insert(newFile);
440 }
441 return newFile;
442 }
443
444 static std::vector<StringRef> missingAutolinkWarnings;
addLibrary(StringRef name,bool isNeeded,bool isWeak,bool isReexport,bool isHidden,bool isExplicit,LoadType loadType)445 static void addLibrary(StringRef name, bool isNeeded, bool isWeak,
446 bool isReexport, bool isHidden, bool isExplicit,
447 LoadType loadType) {
448 if (std::optional<StringRef> path = findLibrary(name)) {
449 if (auto *dylibFile = dyn_cast_or_null<DylibFile>(
450 addFile(*path, loadType, /*isLazy=*/false, isExplicit,
451 /*isBundleLoader=*/false, isHidden))) {
452 if (isNeeded)
453 dylibFile->forceNeeded = true;
454 if (isWeak)
455 dylibFile->forceWeakImport = true;
456 if (isReexport) {
457 config->hasReexports = true;
458 dylibFile->reexport = true;
459 }
460 }
461 return;
462 }
463 if (loadType == LoadType::LCLinkerOption) {
464 missingAutolinkWarnings.push_back(
465 saver().save("auto-linked library not found for -l" + name));
466 return;
467 }
468 error("library not found for -l" + name);
469 }
470
471 static DenseSet<StringRef> loadedObjectFrameworks;
addFramework(StringRef name,bool isNeeded,bool isWeak,bool isReexport,bool isExplicit,LoadType loadType)472 static void addFramework(StringRef name, bool isNeeded, bool isWeak,
473 bool isReexport, bool isExplicit, LoadType loadType) {
474 if (std::optional<StringRef> path = findFramework(name)) {
475 if (loadedObjectFrameworks.contains(*path))
476 return;
477
478 InputFile *file =
479 addFile(*path, loadType, /*isLazy=*/false, isExplicit, false);
480 if (auto *dylibFile = dyn_cast_or_null<DylibFile>(file)) {
481 if (isNeeded)
482 dylibFile->forceNeeded = true;
483 if (isWeak)
484 dylibFile->forceWeakImport = true;
485 if (isReexport) {
486 config->hasReexports = true;
487 dylibFile->reexport = true;
488 }
489 } else if (isa_and_nonnull<ObjFile>(file) ||
490 isa_and_nonnull<BitcodeFile>(file)) {
491 // Cache frameworks containing object or bitcode files to avoid duplicate
492 // symbols. Frameworks containing static archives are cached separately
493 // in addFile() to share caching with libraries, and frameworks
494 // containing dylibs should allow overwriting of attributes such as
495 // forceNeeded by subsequent loads
496 loadedObjectFrameworks.insert(*path);
497 }
498 return;
499 }
500 if (loadType == LoadType::LCLinkerOption) {
501 missingAutolinkWarnings.push_back(
502 saver().save("auto-linked framework not found for -framework " + name));
503 return;
504 }
505 error("framework not found for -framework " + name);
506 }
507
508 // Parses LC_LINKER_OPTION contents, which can add additional command line
509 // flags. This directly parses the flags instead of using the standard argument
510 // parser to improve performance.
parseLCLinkerOption(llvm::SmallVectorImpl<StringRef> & LCLinkerOptions,InputFile * f,unsigned argc,StringRef data)511 void macho::parseLCLinkerOption(
512 llvm::SmallVectorImpl<StringRef> &LCLinkerOptions, InputFile *f,
513 unsigned argc, StringRef data) {
514 if (config->ignoreAutoLink)
515 return;
516
517 SmallVector<StringRef, 4> argv;
518 size_t offset = 0;
519 for (unsigned i = 0; i < argc && offset < data.size(); ++i) {
520 argv.push_back(data.data() + offset);
521 offset += strlen(data.data() + offset) + 1;
522 }
523 if (argv.size() != argc || offset > data.size())
524 fatal(toString(f) + ": invalid LC_LINKER_OPTION");
525
526 unsigned i = 0;
527 StringRef arg = argv[i];
528 if (arg.consume_front("-l")) {
529 if (config->ignoreAutoLinkOptions.contains(arg))
530 return;
531 } else if (arg == "-framework") {
532 StringRef name = argv[++i];
533 if (config->ignoreAutoLinkOptions.contains(name))
534 return;
535 } else {
536 error(arg + " is not allowed in LC_LINKER_OPTION");
537 }
538
539 LCLinkerOptions.append(argv);
540 }
541
resolveLCLinkerOptions()542 void macho::resolveLCLinkerOptions() {
543 while (!unprocessedLCLinkerOptions.empty()) {
544 SmallVector<StringRef> LCLinkerOptions(unprocessedLCLinkerOptions);
545 unprocessedLCLinkerOptions.clear();
546
547 for (unsigned i = 0; i < LCLinkerOptions.size(); ++i) {
548 StringRef arg = LCLinkerOptions[i];
549 if (arg.consume_front("-l")) {
550 assert(!config->ignoreAutoLinkOptions.contains(arg));
551 addLibrary(arg, /*isNeeded=*/false, /*isWeak=*/false,
552 /*isReexport=*/false, /*isHidden=*/false,
553 /*isExplicit=*/false, LoadType::LCLinkerOption);
554 } else if (arg == "-framework") {
555 StringRef name = LCLinkerOptions[++i];
556 assert(!config->ignoreAutoLinkOptions.contains(name));
557 addFramework(name, /*isNeeded=*/false, /*isWeak=*/false,
558 /*isReexport=*/false, /*isExplicit=*/false,
559 LoadType::LCLinkerOption);
560 } else {
561 error(arg + " is not allowed in LC_LINKER_OPTION");
562 }
563 }
564 }
565 }
566
addFileList(StringRef path,bool isLazy)567 static void addFileList(StringRef path, bool isLazy) {
568 std::optional<MemoryBufferRef> buffer = readFile(path);
569 if (!buffer)
570 return;
571 MemoryBufferRef mbref = *buffer;
572 for (StringRef path : args::getLines(mbref))
573 addFile(rerootPath(path), LoadType::CommandLine, isLazy);
574 }
575
576 // We expect sub-library names of the form "libfoo", which will match a dylib
577 // with a path of .*/libfoo.{dylib, tbd}.
578 // XXX ld64 seems to ignore the extension entirely when matching sub-libraries;
579 // I'm not sure what the use case for that is.
markReexport(StringRef searchName,ArrayRef<StringRef> extensions)580 static bool markReexport(StringRef searchName, ArrayRef<StringRef> extensions) {
581 for (InputFile *file : inputFiles) {
582 if (auto *dylibFile = dyn_cast<DylibFile>(file)) {
583 StringRef filename = path::filename(dylibFile->getName());
584 if (filename.consume_front(searchName) &&
585 (filename.empty() || llvm::is_contained(extensions, filename))) {
586 dylibFile->reexport = true;
587 return true;
588 }
589 }
590 }
591 return false;
592 }
593
594 // This function is called on startup. We need this for LTO since
595 // LTO calls LLVM functions to compile bitcode files to native code.
596 // Technically this can be delayed until we read bitcode files, but
597 // we don't bother to do lazily because the initialization is fast.
initLLVM()598 static void initLLVM() {
599 InitializeAllTargets();
600 InitializeAllTargetMCs();
601 InitializeAllAsmPrinters();
602 InitializeAllAsmParsers();
603 }
604
compileBitcodeFiles()605 static bool compileBitcodeFiles() {
606 TimeTraceScope timeScope("LTO");
607 auto *lto = make<BitcodeCompiler>();
608 for (InputFile *file : inputFiles)
609 if (auto *bitcodeFile = dyn_cast<BitcodeFile>(file))
610 if (!file->lazy)
611 lto->add(*bitcodeFile);
612
613 std::vector<ObjFile *> compiled = lto->compile();
614 inputFiles.insert_range(compiled);
615
616 return !compiled.empty();
617 }
618
619 // Replaces common symbols with defined symbols residing in __common sections.
620 // This function must be called after all symbol names are resolved (i.e. after
621 // all InputFiles have been loaded.) As a result, later operations won't see
622 // any CommonSymbols.
replaceCommonSymbols()623 static void replaceCommonSymbols() {
624 TimeTraceScope timeScope("Replace common symbols");
625 ConcatOutputSection *osec = nullptr;
626 for (Symbol *sym : symtab->getSymbols()) {
627 auto *common = dyn_cast<CommonSymbol>(sym);
628 if (common == nullptr)
629 continue;
630
631 // Casting to size_t will truncate large values on 32-bit architectures,
632 // but it's not really worth supporting the linking of 64-bit programs on
633 // 32-bit archs.
634 ArrayRef<uint8_t> data = {nullptr, static_cast<size_t>(common->size)};
635 // FIXME avoid creating one Section per symbol?
636 auto *section =
637 make<Section>(common->getFile(), segment_names::data,
638 section_names::common, S_ZEROFILL, /*addr=*/0);
639 auto *isec = make<ConcatInputSection>(*section, data, common->align);
640 if (!osec)
641 osec = ConcatOutputSection::getOrCreateForInput(isec);
642 isec->parent = osec;
643 addInputSection(isec);
644
645 // FIXME: CommonSymbol should store isReferencedDynamically, noDeadStrip
646 // and pass them on here.
647 replaceSymbol<Defined>(
648 sym, sym->getName(), common->getFile(), isec, /*value=*/0, common->size,
649 /*isWeakDef=*/false, /*isExternal=*/true, common->privateExtern,
650 /*includeInSymtab=*/true, /*isReferencedDynamically=*/false,
651 /*noDeadStrip=*/false);
652 }
653 }
654
initializeSectionRenameMap()655 static void initializeSectionRenameMap() {
656 if (config->dataConst) {
657 SmallVector<StringRef> v{section_names::got,
658 section_names::authGot,
659 section_names::authPtr,
660 section_names::nonLazySymbolPtr,
661 section_names::const_,
662 section_names::cfString,
663 section_names::moduleInitFunc,
664 section_names::moduleTermFunc,
665 section_names::objcClassList,
666 section_names::objcNonLazyClassList,
667 section_names::objcCatList,
668 section_names::objcNonLazyCatList,
669 section_names::objcProtoList,
670 section_names::objCImageInfo};
671 for (StringRef s : v)
672 config->sectionRenameMap[{segment_names::data, s}] = {
673 segment_names::dataConst, s};
674 }
675 config->sectionRenameMap[{segment_names::text, section_names::staticInit}] = {
676 segment_names::text, section_names::text};
677 config->sectionRenameMap[{segment_names::import, section_names::pointers}] = {
678 config->dataConst ? segment_names::dataConst : segment_names::data,
679 section_names::nonLazySymbolPtr};
680 }
681
toLowerDash(char x)682 static inline char toLowerDash(char x) {
683 if (x >= 'A' && x <= 'Z')
684 return x - 'A' + 'a';
685 else if (x == ' ')
686 return '-';
687 return x;
688 }
689
lowerDash(StringRef s)690 static std::string lowerDash(StringRef s) {
691 return std::string(map_iterator(s.begin(), toLowerDash),
692 map_iterator(s.end(), toLowerDash));
693 }
694
695 struct PlatformVersion {
696 PlatformType platform = PLATFORM_UNKNOWN;
697 llvm::VersionTuple minimum;
698 llvm::VersionTuple sdk;
699 };
700
parsePlatformVersion(const Arg * arg)701 static PlatformVersion parsePlatformVersion(const Arg *arg) {
702 assert(arg->getOption().getID() == OPT_platform_version);
703 StringRef platformStr = arg->getValue(0);
704 StringRef minVersionStr = arg->getValue(1);
705 StringRef sdkVersionStr = arg->getValue(2);
706
707 PlatformVersion platformVersion;
708
709 // TODO(compnerd) see if we can generate this case list via XMACROS
710 platformVersion.platform =
711 StringSwitch<PlatformType>(lowerDash(platformStr))
712 .Cases("macos", "1", PLATFORM_MACOS)
713 .Cases("ios", "2", PLATFORM_IOS)
714 .Cases("tvos", "3", PLATFORM_TVOS)
715 .Cases("watchos", "4", PLATFORM_WATCHOS)
716 .Cases("bridgeos", "5", PLATFORM_BRIDGEOS)
717 .Cases("mac-catalyst", "6", PLATFORM_MACCATALYST)
718 .Cases("ios-simulator", "7", PLATFORM_IOSSIMULATOR)
719 .Cases("tvos-simulator", "8", PLATFORM_TVOSSIMULATOR)
720 .Cases("watchos-simulator", "9", PLATFORM_WATCHOSSIMULATOR)
721 .Cases("driverkit", "10", PLATFORM_DRIVERKIT)
722 .Cases("xros", "11", PLATFORM_XROS)
723 .Cases("xros-simulator", "12", PLATFORM_XROS_SIMULATOR)
724 .Default(PLATFORM_UNKNOWN);
725 if (platformVersion.platform == PLATFORM_UNKNOWN)
726 error(Twine("malformed platform: ") + platformStr);
727 // TODO: check validity of version strings, which varies by platform
728 // NOTE: ld64 accepts version strings with 5 components
729 // llvm::VersionTuple accepts no more than 4 components
730 // Has Apple ever published version strings with 5 components?
731 if (platformVersion.minimum.tryParse(minVersionStr))
732 error(Twine("malformed minimum version: ") + minVersionStr);
733 if (platformVersion.sdk.tryParse(sdkVersionStr))
734 error(Twine("malformed sdk version: ") + sdkVersionStr);
735 return platformVersion;
736 }
737
738 // Has the side-effect of setting Config::platformInfo and
739 // potentially Config::secondaryPlatformInfo.
setPlatformVersions(StringRef archName,const ArgList & args)740 static void setPlatformVersions(StringRef archName, const ArgList &args) {
741 std::map<PlatformType, PlatformVersion> platformVersions;
742 const PlatformVersion *lastVersionInfo = nullptr;
743 for (const Arg *arg : args.filtered(OPT_platform_version)) {
744 PlatformVersion version = parsePlatformVersion(arg);
745
746 // For each platform, the last flag wins:
747 // `-platform_version macos 2 3 -platform_version macos 4 5` has the same
748 // effect as just passing `-platform_version macos 4 5`.
749 // FIXME: ld64 warns on multiple flags for one platform. Should we?
750 platformVersions[version.platform] = version;
751 lastVersionInfo = &platformVersions[version.platform];
752 }
753
754 if (platformVersions.empty()) {
755 error("must specify -platform_version");
756 return;
757 }
758 if (platformVersions.size() > 2) {
759 error("must specify -platform_version at most twice");
760 return;
761 }
762 if (platformVersions.size() == 2) {
763 bool isZipperedCatalyst = platformVersions.count(PLATFORM_MACOS) &&
764 platformVersions.count(PLATFORM_MACCATALYST);
765
766 if (!isZipperedCatalyst) {
767 error("lld supports writing zippered outputs only for "
768 "macos and mac-catalyst");
769 } else if (config->outputType != MH_DYLIB &&
770 config->outputType != MH_BUNDLE) {
771 error("writing zippered outputs only valid for -dylib and -bundle");
772 }
773
774 config->platformInfo = {
775 MachO::Target(getArchitectureFromName(archName), PLATFORM_MACOS,
776 platformVersions[PLATFORM_MACOS].minimum),
777 platformVersions[PLATFORM_MACOS].sdk};
778 config->secondaryPlatformInfo = {
779 MachO::Target(getArchitectureFromName(archName), PLATFORM_MACCATALYST,
780 platformVersions[PLATFORM_MACCATALYST].minimum),
781 platformVersions[PLATFORM_MACCATALYST].sdk};
782 return;
783 }
784
785 config->platformInfo = {MachO::Target(getArchitectureFromName(archName),
786 lastVersionInfo->platform,
787 lastVersionInfo->minimum),
788 lastVersionInfo->sdk};
789 }
790
791 // Has the side-effect of setting Config::target.
createTargetInfo(InputArgList & args)792 static TargetInfo *createTargetInfo(InputArgList &args) {
793 StringRef archName = args.getLastArgValue(OPT_arch);
794 if (archName.empty()) {
795 error("must specify -arch");
796 return nullptr;
797 }
798
799 setPlatformVersions(archName, args);
800 auto [cpuType, cpuSubtype] = getCPUTypeFromArchitecture(config->arch());
801 switch (cpuType) {
802 case CPU_TYPE_X86_64:
803 return createX86_64TargetInfo();
804 case CPU_TYPE_ARM64:
805 return createARM64TargetInfo();
806 case CPU_TYPE_ARM64_32:
807 return createARM64_32TargetInfo();
808 default:
809 error("missing or unsupported -arch " + archName);
810 return nullptr;
811 }
812 }
813
814 static UndefinedSymbolTreatment
getUndefinedSymbolTreatment(const ArgList & args)815 getUndefinedSymbolTreatment(const ArgList &args) {
816 StringRef treatmentStr = args.getLastArgValue(OPT_undefined);
817 auto treatment =
818 StringSwitch<UndefinedSymbolTreatment>(treatmentStr)
819 .Cases("error", "", UndefinedSymbolTreatment::error)
820 .Case("warning", UndefinedSymbolTreatment::warning)
821 .Case("suppress", UndefinedSymbolTreatment::suppress)
822 .Case("dynamic_lookup", UndefinedSymbolTreatment::dynamic_lookup)
823 .Default(UndefinedSymbolTreatment::unknown);
824 if (treatment == UndefinedSymbolTreatment::unknown) {
825 warn(Twine("unknown -undefined TREATMENT '") + treatmentStr +
826 "', defaulting to 'error'");
827 treatment = UndefinedSymbolTreatment::error;
828 } else if (config->namespaceKind == NamespaceKind::twolevel &&
829 (treatment == UndefinedSymbolTreatment::warning ||
830 treatment == UndefinedSymbolTreatment::suppress)) {
831 if (treatment == UndefinedSymbolTreatment::warning)
832 fatal("'-undefined warning' only valid with '-flat_namespace'");
833 else
834 fatal("'-undefined suppress' only valid with '-flat_namespace'");
835 treatment = UndefinedSymbolTreatment::error;
836 }
837 return treatment;
838 }
839
getICFLevel(const ArgList & args)840 static ICFLevel getICFLevel(const ArgList &args) {
841 StringRef icfLevelStr = args.getLastArgValue(OPT_icf_eq);
842 auto icfLevel = StringSwitch<ICFLevel>(icfLevelStr)
843 .Cases("none", "", ICFLevel::none)
844 .Case("safe", ICFLevel::safe)
845 .Case("safe_thunks", ICFLevel::safe_thunks)
846 .Case("all", ICFLevel::all)
847 .Default(ICFLevel::unknown);
848
849 if ((icfLevel == ICFLevel::safe_thunks) && (config->arch() != AK_arm64)) {
850 error("--icf=safe_thunks is only supported on arm64 targets");
851 }
852
853 if (icfLevel == ICFLevel::unknown) {
854 warn(Twine("unknown --icf=OPTION `") + icfLevelStr +
855 "', defaulting to `none'");
856 icfLevel = ICFLevel::none;
857 }
858 return icfLevel;
859 }
860
getObjCStubsMode(const ArgList & args)861 static ObjCStubsMode getObjCStubsMode(const ArgList &args) {
862 const Arg *arg = args.getLastArg(OPT_objc_stubs_fast, OPT_objc_stubs_small);
863 if (!arg)
864 return ObjCStubsMode::fast;
865
866 if (arg->getOption().getID() == OPT_objc_stubs_small) {
867 if (is_contained({AK_arm64e, AK_arm64}, config->arch()))
868 return ObjCStubsMode::small;
869 else
870 warn("-objc_stubs_small is not yet implemented, defaulting to "
871 "-objc_stubs_fast");
872 }
873 return ObjCStubsMode::fast;
874 }
875
warnIfDeprecatedOption(const Option & opt)876 static void warnIfDeprecatedOption(const Option &opt) {
877 if (!opt.getGroup().isValid())
878 return;
879 if (opt.getGroup().getID() == OPT_grp_deprecated) {
880 warn("Option `" + opt.getPrefixedName() + "' is deprecated in ld64:");
881 warn(opt.getHelpText());
882 }
883 }
884
warnIfUnimplementedOption(const Option & opt)885 static void warnIfUnimplementedOption(const Option &opt) {
886 if (!opt.getGroup().isValid() || !opt.hasFlag(DriverFlag::HelpHidden))
887 return;
888 switch (opt.getGroup().getID()) {
889 case OPT_grp_deprecated:
890 // warn about deprecated options elsewhere
891 break;
892 case OPT_grp_undocumented:
893 warn("Option `" + opt.getPrefixedName() +
894 "' is undocumented. Should lld implement it?");
895 break;
896 case OPT_grp_obsolete:
897 warn("Option `" + opt.getPrefixedName() +
898 "' is obsolete. Please modernize your usage.");
899 break;
900 case OPT_grp_ignored:
901 warn("Option `" + opt.getPrefixedName() + "' is ignored.");
902 break;
903 case OPT_grp_ignored_silently:
904 break;
905 default:
906 warn("Option `" + opt.getPrefixedName() +
907 "' is not yet implemented. Stay tuned...");
908 break;
909 }
910 }
911
getReproduceOption(InputArgList & args)912 static const char *getReproduceOption(InputArgList &args) {
913 if (const Arg *arg = args.getLastArg(OPT_reproduce))
914 return arg->getValue();
915 return getenv("LLD_REPRODUCE");
916 }
917
918 // Parse options of the form "old;new".
getOldNewOptions(opt::InputArgList & args,unsigned id)919 static std::pair<StringRef, StringRef> getOldNewOptions(opt::InputArgList &args,
920 unsigned id) {
921 auto *arg = args.getLastArg(id);
922 if (!arg)
923 return {"", ""};
924
925 StringRef s = arg->getValue();
926 std::pair<StringRef, StringRef> ret = s.split(';');
927 if (ret.second.empty())
928 error(arg->getSpelling() + " expects 'old;new' format, but got " + s);
929 return ret;
930 }
931
932 // Parse options of the form "old;new[;extra]".
933 static std::tuple<StringRef, StringRef, StringRef>
getOldNewOptionsExtra(opt::InputArgList & args,unsigned id)934 getOldNewOptionsExtra(opt::InputArgList &args, unsigned id) {
935 auto [oldDir, second] = getOldNewOptions(args, id);
936 auto [newDir, extraDir] = second.split(';');
937 return {oldDir, newDir, extraDir};
938 }
939
parseClangOption(StringRef opt,const Twine & msg)940 static void parseClangOption(StringRef opt, const Twine &msg) {
941 std::string err;
942 raw_string_ostream os(err);
943
944 const char *argv[] = {"lld", opt.data()};
945 if (cl::ParseCommandLineOptions(2, argv, "", &os))
946 return;
947 error(msg + ": " + StringRef(err).trim());
948 }
949
parseDylibVersion(const ArgList & args,unsigned id)950 static uint32_t parseDylibVersion(const ArgList &args, unsigned id) {
951 const Arg *arg = args.getLastArg(id);
952 if (!arg)
953 return 0;
954
955 if (config->outputType != MH_DYLIB) {
956 error(arg->getAsString(args) + ": only valid with -dylib");
957 return 0;
958 }
959
960 PackedVersion version;
961 if (!version.parse32(arg->getValue())) {
962 error(arg->getAsString(args) + ": malformed version");
963 return 0;
964 }
965
966 return version.rawValue();
967 }
968
parseProtection(StringRef protStr)969 static uint32_t parseProtection(StringRef protStr) {
970 uint32_t prot = 0;
971 for (char c : protStr) {
972 switch (c) {
973 case 'r':
974 prot |= VM_PROT_READ;
975 break;
976 case 'w':
977 prot |= VM_PROT_WRITE;
978 break;
979 case 'x':
980 prot |= VM_PROT_EXECUTE;
981 break;
982 case '-':
983 break;
984 default:
985 error("unknown -segprot letter '" + Twine(c) + "' in " + protStr);
986 return 0;
987 }
988 }
989 return prot;
990 }
991
parseSectAlign(const opt::InputArgList & args)992 static std::vector<SectionAlign> parseSectAlign(const opt::InputArgList &args) {
993 std::vector<SectionAlign> sectAligns;
994 for (const Arg *arg : args.filtered(OPT_sectalign)) {
995 StringRef segName = arg->getValue(0);
996 StringRef sectName = arg->getValue(1);
997 StringRef alignStr = arg->getValue(2);
998 alignStr.consume_front_insensitive("0x");
999 uint32_t align;
1000 if (alignStr.getAsInteger(16, align)) {
1001 error("-sectalign: failed to parse '" + StringRef(arg->getValue(2)) +
1002 "' as number");
1003 continue;
1004 }
1005 if (!isPowerOf2_32(align)) {
1006 error("-sectalign: '" + StringRef(arg->getValue(2)) +
1007 "' (in base 16) not a power of two");
1008 continue;
1009 }
1010 sectAligns.push_back({segName, sectName, align});
1011 }
1012 return sectAligns;
1013 }
1014
removeSimulator(PlatformType platform)1015 PlatformType macho::removeSimulator(PlatformType platform) {
1016 switch (platform) {
1017 case PLATFORM_IOSSIMULATOR:
1018 return PLATFORM_IOS;
1019 case PLATFORM_TVOSSIMULATOR:
1020 return PLATFORM_TVOS;
1021 case PLATFORM_WATCHOSSIMULATOR:
1022 return PLATFORM_WATCHOS;
1023 case PLATFORM_XROS_SIMULATOR:
1024 return PLATFORM_XROS;
1025 default:
1026 return platform;
1027 }
1028 }
1029
supportsNoPie()1030 static bool supportsNoPie() {
1031 return !(config->arch() == AK_arm64 || config->arch() == AK_arm64e ||
1032 config->arch() == AK_arm64_32);
1033 }
1034
shouldAdhocSignByDefault(Architecture arch,PlatformType platform)1035 static bool shouldAdhocSignByDefault(Architecture arch, PlatformType platform) {
1036 if (arch != AK_arm64 && arch != AK_arm64e)
1037 return false;
1038
1039 return platform == PLATFORM_MACOS || platform == PLATFORM_IOSSIMULATOR ||
1040 platform == PLATFORM_TVOSSIMULATOR ||
1041 platform == PLATFORM_WATCHOSSIMULATOR ||
1042 platform == PLATFORM_XROS_SIMULATOR;
1043 }
1044
1045 template <std::size_t N>
1046 using MinVersions = std::array<std::pair<PlatformType, VersionTuple>, N>;
1047
1048 /// Returns true if the platform is greater than the min version.
1049 /// Returns false if the platform does not exist.
1050 template <std::size_t N>
greaterEqMinVersion(const MinVersions<N> & minVersions,bool ignoreSimulator)1051 static bool greaterEqMinVersion(const MinVersions<N> &minVersions,
1052 bool ignoreSimulator) {
1053 PlatformType platform = config->platformInfo.target.Platform;
1054 if (ignoreSimulator)
1055 platform = removeSimulator(platform);
1056 auto it = llvm::find_if(minVersions,
1057 [&](const auto &p) { return p.first == platform; });
1058 if (it != minVersions.end())
1059 if (config->platformInfo.target.MinDeployment >= it->second)
1060 return true;
1061 return false;
1062 }
1063
dataConstDefault(const InputArgList & args)1064 static bool dataConstDefault(const InputArgList &args) {
1065 static const MinVersions<6> minVersion = {{
1066 {PLATFORM_MACOS, VersionTuple(10, 15)},
1067 {PLATFORM_IOS, VersionTuple(13, 0)},
1068 {PLATFORM_TVOS, VersionTuple(13, 0)},
1069 {PLATFORM_WATCHOS, VersionTuple(6, 0)},
1070 {PLATFORM_XROS, VersionTuple(1, 0)},
1071 {PLATFORM_BRIDGEOS, VersionTuple(4, 0)},
1072 }};
1073 if (!greaterEqMinVersion(minVersion, true))
1074 return false;
1075
1076 switch (config->outputType) {
1077 case MH_EXECUTE:
1078 return !(args.hasArg(OPT_no_pie) && supportsNoPie());
1079 case MH_BUNDLE:
1080 // FIXME: return false when -final_name ...
1081 // has prefix "/System/Library/UserEventPlugins/"
1082 // or matches "/usr/libexec/locationd" "/usr/libexec/terminusd"
1083 return true;
1084 case MH_DYLIB:
1085 return true;
1086 case MH_OBJECT:
1087 return false;
1088 default:
1089 llvm_unreachable(
1090 "unsupported output type for determining data-const default");
1091 }
1092 return false;
1093 }
1094
shouldEmitChainedFixups(const InputArgList & args)1095 static bool shouldEmitChainedFixups(const InputArgList &args) {
1096 const Arg *arg = args.getLastArg(OPT_fixup_chains, OPT_no_fixup_chains);
1097 if (arg && arg->getOption().matches(OPT_no_fixup_chains))
1098 return false;
1099
1100 bool requested = arg && arg->getOption().matches(OPT_fixup_chains);
1101 if (!config->isPic) {
1102 if (requested)
1103 error("-fixup_chains is incompatible with -no_pie");
1104
1105 return false;
1106 }
1107
1108 if (!is_contained({AK_x86_64, AK_x86_64h, AK_arm64}, config->arch())) {
1109 if (requested)
1110 error("-fixup_chains is only supported on x86_64 and arm64 targets");
1111
1112 return false;
1113 }
1114
1115 if (args.hasArg(OPT_preload)) {
1116 if (requested)
1117 error("-fixup_chains is incompatible with -preload");
1118
1119 return false;
1120 }
1121
1122 if (requested)
1123 return true;
1124
1125 static const MinVersions<9> minVersion = {{
1126 {PLATFORM_IOS, VersionTuple(13, 4)},
1127 {PLATFORM_IOSSIMULATOR, VersionTuple(16, 0)},
1128 {PLATFORM_MACOS, VersionTuple(13, 0)},
1129 {PLATFORM_TVOS, VersionTuple(14, 0)},
1130 {PLATFORM_TVOSSIMULATOR, VersionTuple(15, 0)},
1131 {PLATFORM_WATCHOS, VersionTuple(7, 0)},
1132 {PLATFORM_WATCHOSSIMULATOR, VersionTuple(8, 0)},
1133 {PLATFORM_XROS, VersionTuple(1, 0)},
1134 {PLATFORM_XROS_SIMULATOR, VersionTuple(1, 0)},
1135 }};
1136 return greaterEqMinVersion(minVersion, false);
1137 }
1138
shouldEmitRelativeMethodLists(const InputArgList & args)1139 static bool shouldEmitRelativeMethodLists(const InputArgList &args) {
1140 const Arg *arg = args.getLastArg(OPT_objc_relative_method_lists,
1141 OPT_no_objc_relative_method_lists);
1142 if (arg && arg->getOption().getID() == OPT_objc_relative_method_lists)
1143 return true;
1144 if (arg && arg->getOption().getID() == OPT_no_objc_relative_method_lists)
1145 return false;
1146
1147 // If no flag is specified, enable this on newer versions by default.
1148 // The min versions is taken from
1149 // ld64(https://github.com/apple-oss-distributions/ld64/blob/47f477cb721755419018f7530038b272e9d0cdea/src/ld/ld.hpp#L310)
1150 // to mimic to operation of ld64
1151 // [here](https://github.com/apple-oss-distributions/ld64/blob/47f477cb721755419018f7530038b272e9d0cdea/src/ld/Options.cpp#L6085-L6101)
1152 static const MinVersions<6> minVersion = {{
1153 {PLATFORM_MACOS, VersionTuple(10, 16)},
1154 {PLATFORM_IOS, VersionTuple(14, 0)},
1155 {PLATFORM_WATCHOS, VersionTuple(7, 0)},
1156 {PLATFORM_TVOS, VersionTuple(14, 0)},
1157 {PLATFORM_BRIDGEOS, VersionTuple(5, 0)},
1158 {PLATFORM_XROS, VersionTuple(1, 0)},
1159 }};
1160 return greaterEqMinVersion(minVersion, true);
1161 }
1162
clear()1163 void SymbolPatterns::clear() {
1164 literals.clear();
1165 globs.clear();
1166 }
1167
insert(StringRef symbolName)1168 void SymbolPatterns::insert(StringRef symbolName) {
1169 if (symbolName.find_first_of("*?[]") == StringRef::npos)
1170 literals.insert(CachedHashStringRef(symbolName));
1171 else if (Expected<GlobPattern> pattern = GlobPattern::create(symbolName))
1172 globs.emplace_back(*pattern);
1173 else
1174 error("invalid symbol-name pattern: " + symbolName);
1175 }
1176
matchLiteral(StringRef symbolName) const1177 bool SymbolPatterns::matchLiteral(StringRef symbolName) const {
1178 return literals.contains(CachedHashStringRef(symbolName));
1179 }
1180
matchGlob(StringRef symbolName) const1181 bool SymbolPatterns::matchGlob(StringRef symbolName) const {
1182 for (const GlobPattern &glob : globs)
1183 if (glob.match(symbolName))
1184 return true;
1185 return false;
1186 }
1187
match(StringRef symbolName) const1188 bool SymbolPatterns::match(StringRef symbolName) const {
1189 return matchLiteral(symbolName) || matchGlob(symbolName);
1190 }
1191
parseSymbolPatternsFile(const Arg * arg,SymbolPatterns & symbolPatterns)1192 static void parseSymbolPatternsFile(const Arg *arg,
1193 SymbolPatterns &symbolPatterns) {
1194 StringRef path = arg->getValue();
1195 std::optional<MemoryBufferRef> buffer = readFile(path);
1196 if (!buffer) {
1197 error("Could not read symbol file: " + path);
1198 return;
1199 }
1200 MemoryBufferRef mbref = *buffer;
1201 for (StringRef line : args::getLines(mbref)) {
1202 line = line.take_until([](char c) { return c == '#'; }).trim();
1203 if (!line.empty())
1204 symbolPatterns.insert(line);
1205 }
1206 }
1207
handleSymbolPatterns(InputArgList & args,SymbolPatterns & symbolPatterns,unsigned singleOptionCode,unsigned listFileOptionCode)1208 static void handleSymbolPatterns(InputArgList &args,
1209 SymbolPatterns &symbolPatterns,
1210 unsigned singleOptionCode,
1211 unsigned listFileOptionCode) {
1212 for (const Arg *arg : args.filtered(singleOptionCode))
1213 symbolPatterns.insert(arg->getValue());
1214 for (const Arg *arg : args.filtered(listFileOptionCode))
1215 parseSymbolPatternsFile(arg, symbolPatterns);
1216 }
1217
createFiles(const InputArgList & args)1218 static void createFiles(const InputArgList &args) {
1219 TimeTraceScope timeScope("Load input files");
1220 // This loop should be reserved for options whose exact ordering matters.
1221 // Other options should be handled via filtered() and/or getLastArg().
1222 bool isLazy = false;
1223 // If we've processed an opening --start-lib, without a matching --end-lib
1224 bool inLib = false;
1225 for (const Arg *arg : args) {
1226 const Option &opt = arg->getOption();
1227 warnIfDeprecatedOption(opt);
1228 warnIfUnimplementedOption(opt);
1229
1230 switch (opt.getID()) {
1231 case OPT_INPUT:
1232 addFile(rerootPath(arg->getValue()), LoadType::CommandLine, isLazy);
1233 break;
1234 case OPT_needed_library:
1235 if (auto *dylibFile = dyn_cast_or_null<DylibFile>(
1236 addFile(rerootPath(arg->getValue()), LoadType::CommandLine)))
1237 dylibFile->forceNeeded = true;
1238 break;
1239 case OPT_reexport_library:
1240 if (auto *dylibFile = dyn_cast_or_null<DylibFile>(
1241 addFile(rerootPath(arg->getValue()), LoadType::CommandLine))) {
1242 config->hasReexports = true;
1243 dylibFile->reexport = true;
1244 }
1245 break;
1246 case OPT_weak_library:
1247 if (auto *dylibFile = dyn_cast_or_null<DylibFile>(
1248 addFile(rerootPath(arg->getValue()), LoadType::CommandLine)))
1249 dylibFile->forceWeakImport = true;
1250 break;
1251 case OPT_filelist:
1252 addFileList(arg->getValue(), isLazy);
1253 break;
1254 case OPT_force_load:
1255 addFile(rerootPath(arg->getValue()), LoadType::CommandLineForce);
1256 break;
1257 case OPT_load_hidden:
1258 addFile(rerootPath(arg->getValue()), LoadType::CommandLine,
1259 /*isLazy=*/false, /*isExplicit=*/true, /*isBundleLoader=*/false,
1260 /*isForceHidden=*/true);
1261 break;
1262 case OPT_l:
1263 case OPT_needed_l:
1264 case OPT_reexport_l:
1265 case OPT_weak_l:
1266 case OPT_hidden_l:
1267 addLibrary(arg->getValue(), opt.getID() == OPT_needed_l,
1268 opt.getID() == OPT_weak_l, opt.getID() == OPT_reexport_l,
1269 opt.getID() == OPT_hidden_l,
1270 /*isExplicit=*/true, LoadType::CommandLine);
1271 break;
1272 case OPT_framework:
1273 case OPT_needed_framework:
1274 case OPT_reexport_framework:
1275 case OPT_weak_framework:
1276 addFramework(arg->getValue(), opt.getID() == OPT_needed_framework,
1277 opt.getID() == OPT_weak_framework,
1278 opt.getID() == OPT_reexport_framework, /*isExplicit=*/true,
1279 LoadType::CommandLine);
1280 break;
1281 case OPT_start_lib:
1282 if (inLib)
1283 error("nested --start-lib");
1284 inLib = true;
1285 if (!config->allLoad)
1286 isLazy = true;
1287 break;
1288 case OPT_end_lib:
1289 if (!inLib)
1290 error("stray --end-lib");
1291 inLib = false;
1292 isLazy = false;
1293 break;
1294 default:
1295 break;
1296 }
1297 }
1298 }
1299
gatherInputSections()1300 static void gatherInputSections() {
1301 TimeTraceScope timeScope("Gathering input sections");
1302 for (const InputFile *file : inputFiles) {
1303 for (const Section *section : file->sections) {
1304 // Compact unwind entries require special handling elsewhere. (In
1305 // contrast, EH frames are handled like regular ConcatInputSections.)
1306 if (section->name == section_names::compactUnwind)
1307 continue;
1308 // Addrsig sections contain metadata only needed at link time.
1309 if (section->name == section_names::addrSig)
1310 continue;
1311 for (const Subsection &subsection : section->subsections)
1312 addInputSection(subsection.isec);
1313 }
1314 if (!file->objCImageInfo.empty())
1315 in.objCImageInfo->addFile(file);
1316 }
1317 }
1318
codegenDataGenerate()1319 static void codegenDataGenerate() {
1320 TimeTraceScope timeScope("Generating codegen data");
1321
1322 OutlinedHashTreeRecord globalOutlineRecord;
1323 StableFunctionMapRecord globalMergeRecord;
1324 for (ConcatInputSection *isec : inputSections) {
1325 if (isec->getSegName() != segment_names::data)
1326 continue;
1327 if (isec->getName() == section_names::outlinedHashTree) {
1328 // Read outlined hash tree from each section.
1329 OutlinedHashTreeRecord localOutlineRecord;
1330 // Use a pointer to allow modification by the function.
1331 auto *data = isec->data.data();
1332 localOutlineRecord.deserialize(data);
1333
1334 // Merge it to the global hash tree.
1335 globalOutlineRecord.merge(localOutlineRecord);
1336 }
1337 if (isec->getName() == section_names::functionMap) {
1338 // Read stable functions from each section.
1339 StableFunctionMapRecord localMergeRecord;
1340 // Use a pointer to allow modification by the function.
1341 auto *data = isec->data.data();
1342 localMergeRecord.deserialize(data);
1343
1344 // Merge it to the global function map.
1345 globalMergeRecord.merge(localMergeRecord);
1346 }
1347 }
1348
1349 globalMergeRecord.finalize();
1350
1351 CodeGenDataWriter Writer;
1352 if (!globalOutlineRecord.empty())
1353 Writer.addRecord(globalOutlineRecord);
1354 if (!globalMergeRecord.empty())
1355 Writer.addRecord(globalMergeRecord);
1356
1357 std::error_code EC;
1358 auto fileName = config->codegenDataGeneratePath;
1359 assert(!fileName.empty());
1360 raw_fd_ostream Output(fileName, EC, sys::fs::OF_None);
1361 if (EC)
1362 error("fail to create " + fileName + ": " + EC.message());
1363
1364 if (auto E = Writer.write(Output))
1365 error("fail to write CGData: " + toString(std::move(E)));
1366 }
1367
foldIdenticalLiterals()1368 static void foldIdenticalLiterals() {
1369 TimeTraceScope timeScope("Fold identical literals");
1370 // We always create a cStringSection, regardless of whether dedupLiterals is
1371 // true. If it isn't, we simply create a non-deduplicating CStringSection.
1372 // Either way, we must unconditionally finalize it here.
1373 in.cStringSection->finalizeContents();
1374 in.objcMethnameSection->finalizeContents();
1375 in.wordLiteralSection->finalizeContents();
1376 }
1377
addSynthenticMethnames()1378 static void addSynthenticMethnames() {
1379 std::string &data = *make<std::string>();
1380 llvm::raw_string_ostream os(data);
1381 for (Symbol *sym : symtab->getSymbols())
1382 if (isa<Undefined>(sym))
1383 if (ObjCStubsSection::isObjCStubSymbol(sym))
1384 os << ObjCStubsSection::getMethname(sym) << '\0';
1385
1386 if (data.empty())
1387 return;
1388
1389 const auto *buf = reinterpret_cast<const uint8_t *>(data.c_str());
1390 Section §ion = *make<Section>(/*file=*/nullptr, segment_names::text,
1391 section_names::objcMethname,
1392 S_CSTRING_LITERALS, /*addr=*/0);
1393
1394 auto *isec =
1395 make<CStringInputSection>(section, ArrayRef<uint8_t>{buf, data.size()},
1396 /*align=*/1, /*dedupLiterals=*/true);
1397 isec->splitIntoPieces();
1398 for (auto &piece : isec->pieces)
1399 piece.live = true;
1400 section.subsections.push_back({0, isec});
1401 in.objcMethnameSection->addInput(isec);
1402 in.objcMethnameSection->isec->markLive(0);
1403 }
1404
referenceStubBinder()1405 static void referenceStubBinder() {
1406 bool needsStubHelper = config->outputType == MH_DYLIB ||
1407 config->outputType == MH_EXECUTE ||
1408 config->outputType == MH_BUNDLE;
1409 if (!needsStubHelper || !symtab->find("dyld_stub_binder"))
1410 return;
1411
1412 // dyld_stub_binder is used by dyld to resolve lazy bindings. This code here
1413 // adds a opportunistic reference to dyld_stub_binder if it happens to exist.
1414 // dyld_stub_binder is in libSystem.dylib, which is usually linked in. This
1415 // isn't needed for correctness, but the presence of that symbol suppresses
1416 // "no symbols" diagnostics from `nm`.
1417 // StubHelperSection::setUp() adds a reference and errors out if
1418 // dyld_stub_binder doesn't exist in case it is actually needed.
1419 symtab->addUndefined("dyld_stub_binder", /*file=*/nullptr, /*isWeak=*/false);
1420 }
1421
createAliases()1422 static void createAliases() {
1423 for (const auto &pair : config->aliasedSymbols) {
1424 if (const auto &sym = symtab->find(pair.first)) {
1425 if (const auto &defined = dyn_cast<Defined>(sym)) {
1426 symtab->aliasDefined(defined, pair.second, defined->getFile())
1427 ->noDeadStrip = true;
1428 } else {
1429 error("TODO: support aliasing to symbols of kind " +
1430 Twine(sym->kind()));
1431 }
1432 } else {
1433 warn("undefined base symbol '" + pair.first + "' for alias '" +
1434 pair.second + "'\n");
1435 }
1436 }
1437
1438 for (const InputFile *file : inputFiles) {
1439 if (auto *objFile = dyn_cast<ObjFile>(file)) {
1440 for (const AliasSymbol *alias : objFile->aliases) {
1441 if (const auto &aliased = symtab->find(alias->getAliasedName())) {
1442 if (const auto &defined = dyn_cast<Defined>(aliased)) {
1443 symtab->aliasDefined(defined, alias->getName(), alias->getFile(),
1444 alias->privateExtern);
1445 } else {
1446 // Common, dylib, and undefined symbols are all valid alias
1447 // referents (undefineds can become valid Defined symbols later on
1448 // in the link.)
1449 error("TODO: support aliasing to symbols of kind " +
1450 Twine(aliased->kind()));
1451 }
1452 } else {
1453 // This shouldn't happen since MC generates undefined symbols to
1454 // represent the alias referents. Thus we fatal() instead of just
1455 // warning here.
1456 fatal("unable to find alias referent " + alias->getAliasedName() +
1457 " for " + alias->getName());
1458 }
1459 }
1460 }
1461 }
1462 }
1463
handleExplicitExports()1464 static void handleExplicitExports() {
1465 static constexpr int kMaxWarnings = 3;
1466 if (config->hasExplicitExports) {
1467 std::atomic<uint64_t> warningsCount{0};
1468 parallelForEach(symtab->getSymbols(), [&warningsCount](Symbol *sym) {
1469 if (auto *defined = dyn_cast<Defined>(sym)) {
1470 if (config->exportedSymbols.match(sym->getName())) {
1471 if (defined->privateExtern) {
1472 if (defined->weakDefCanBeHidden) {
1473 // weak_def_can_be_hidden symbols behave similarly to
1474 // private_extern symbols in most cases, except for when
1475 // it is explicitly exported.
1476 // The former can be exported but the latter cannot.
1477 defined->privateExtern = false;
1478 } else {
1479 // Only print the first 3 warnings verbosely, and
1480 // shorten the rest to avoid crowding logs.
1481 if (warningsCount.fetch_add(1, std::memory_order_relaxed) <
1482 kMaxWarnings)
1483 warn("cannot export hidden symbol " + toString(*defined) +
1484 "\n>>> defined in " + toString(defined->getFile()));
1485 }
1486 }
1487 } else {
1488 defined->privateExtern = true;
1489 }
1490 } else if (auto *dysym = dyn_cast<DylibSymbol>(sym)) {
1491 dysym->shouldReexport = config->exportedSymbols.match(sym->getName());
1492 }
1493 });
1494 if (warningsCount > kMaxWarnings)
1495 warn("<... " + Twine(warningsCount - kMaxWarnings) +
1496 " more similar warnings...>");
1497 } else if (!config->unexportedSymbols.empty()) {
1498 parallelForEach(symtab->getSymbols(), [](Symbol *sym) {
1499 if (auto *defined = dyn_cast<Defined>(sym))
1500 if (config->unexportedSymbols.match(defined->getName()))
1501 defined->privateExtern = true;
1502 });
1503 }
1504 }
1505
eraseInitializerSymbols()1506 static void eraseInitializerSymbols() {
1507 for (ConcatInputSection *isec : in.initOffsets->inputs())
1508 for (Defined *sym : isec->symbols)
1509 sym->used = false;
1510 }
1511
getRuntimePaths(opt::InputArgList & args)1512 static SmallVector<StringRef, 0> getRuntimePaths(opt::InputArgList &args) {
1513 SmallVector<StringRef, 0> vals;
1514 DenseSet<StringRef> seen;
1515 for (const Arg *arg : args.filtered(OPT_rpath)) {
1516 StringRef val = arg->getValue();
1517 if (seen.insert(val).second)
1518 vals.push_back(val);
1519 else if (config->warnDuplicateRpath)
1520 warn("duplicate -rpath '" + val + "' ignored [--warn-duplicate-rpath]");
1521 }
1522 return vals;
1523 }
1524
getAllowableClients(opt::InputArgList & args)1525 static SmallVector<StringRef, 0> getAllowableClients(opt::InputArgList &args) {
1526 SmallVector<StringRef, 0> vals;
1527 DenseSet<StringRef> seen;
1528 for (const Arg *arg : args.filtered(OPT_allowable_client)) {
1529 StringRef val = arg->getValue();
1530 if (seen.insert(val).second)
1531 vals.push_back(val);
1532 }
1533 return vals;
1534 }
1535
1536 namespace lld {
1537 namespace macho {
link(ArrayRef<const char * > argsArr,llvm::raw_ostream & stdoutOS,llvm::raw_ostream & stderrOS,bool exitEarly,bool disableOutput)1538 bool link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
1539 llvm::raw_ostream &stderrOS, bool exitEarly, bool disableOutput) {
1540 // This driver-specific context will be freed later by lldMain().
1541 auto *ctx = new CommonLinkerContext;
1542
1543 ctx->e.initialize(stdoutOS, stderrOS, exitEarly, disableOutput);
1544 ctx->e.cleanupCallback = []() {
1545 resolvedFrameworks.clear();
1546 resolvedLibraries.clear();
1547 cachedReads.clear();
1548 concatOutputSections.clear();
1549 inputFiles.clear();
1550 inputSections.clear();
1551 inputSectionsOrder = 0;
1552 loadedArchives.clear();
1553 loadedObjectFrameworks.clear();
1554 missingAutolinkWarnings.clear();
1555 syntheticSections.clear();
1556 thunkMap.clear();
1557 unprocessedLCLinkerOptions.clear();
1558 ObjCSelRefsHelper::cleanup();
1559
1560 firstTLVDataSection = nullptr;
1561 tar = nullptr;
1562 memset(&in, 0, sizeof(in));
1563
1564 resetLoadedDylibs();
1565 resetOutputSegments();
1566 resetWriter();
1567 InputFile::resetIdCount();
1568
1569 objc::doCleanup();
1570 };
1571
1572 ctx->e.logName = args::getFilenameWithoutExe(argsArr[0]);
1573
1574 MachOOptTable parser;
1575 InputArgList args = parser.parse(*ctx, argsArr.slice(1));
1576
1577 ctx->e.errorLimitExceededMsg = "too many errors emitted, stopping now "
1578 "(use --error-limit=0 to see all errors)";
1579 ctx->e.errorLimit = args::getInteger(args, OPT_error_limit_eq, 20);
1580 ctx->e.verbose = args.hasArg(OPT_verbose);
1581
1582 if (args.hasArg(OPT_help_hidden)) {
1583 parser.printHelp(*ctx, argsArr[0], /*showHidden=*/true);
1584 return true;
1585 }
1586 if (args.hasArg(OPT_help)) {
1587 parser.printHelp(*ctx, argsArr[0], /*showHidden=*/false);
1588 return true;
1589 }
1590 if (args.hasArg(OPT_version)) {
1591 message(getLLDVersion());
1592 return true;
1593 }
1594
1595 config = std::make_unique<Configuration>();
1596 symtab = std::make_unique<SymbolTable>();
1597 config->outputType = getOutputType(args);
1598 target = createTargetInfo(args);
1599 depTracker = std::make_unique<DependencyTracker>(
1600 args.getLastArgValue(OPT_dependency_info));
1601
1602 config->ltoo = args::getInteger(args, OPT_lto_O, 2);
1603 if (config->ltoo > 3)
1604 error("--lto-O: invalid optimization level: " + Twine(config->ltoo));
1605 unsigned ltoCgo =
1606 args::getInteger(args, OPT_lto_CGO, args::getCGOptLevel(config->ltoo));
1607 if (auto level = CodeGenOpt::getLevel(ltoCgo))
1608 config->ltoCgo = *level;
1609 else
1610 error("--lto-CGO: invalid codegen optimization level: " + Twine(ltoCgo));
1611
1612 if (errorCount())
1613 return false;
1614
1615 if (args.hasArg(OPT_pagezero_size)) {
1616 uint64_t pagezeroSize = args::getHex(args, OPT_pagezero_size, 0);
1617
1618 // ld64 does something really weird. It attempts to realign the value to the
1619 // page size, but assumes the page size is 4K. This doesn't work with most
1620 // of Apple's ARM64 devices, which use a page size of 16K. This means that
1621 // it will first 4K align it by rounding down, then round up to 16K. This
1622 // probably only happened because no one using this arg with anything other
1623 // then 0, so no one checked if it did what is what it says it does.
1624
1625 // So we are not copying this weird behavior and doing the it in a logical
1626 // way, by always rounding down to page size.
1627 if (!isAligned(Align(target->getPageSize()), pagezeroSize)) {
1628 pagezeroSize -= pagezeroSize % target->getPageSize();
1629 warn("__PAGEZERO size is not page aligned, rounding down to 0x" +
1630 Twine::utohexstr(pagezeroSize));
1631 }
1632
1633 target->pageZeroSize = pagezeroSize;
1634 }
1635
1636 config->osoPrefix = args.getLastArgValue(OPT_oso_prefix);
1637 if (!config->osoPrefix.empty()) {
1638 // Expand special characters, such as ".", "..", or "~", if present.
1639 // Note: LD64 only expands "." and not other special characters.
1640 // That seems silly to imitate so we will not try to follow it, but rather
1641 // just use real_path() to do it.
1642
1643 // The max path length is 4096, in theory. However that seems quite long
1644 // and seems unlikely that any one would want to strip everything from the
1645 // path. Hence we've picked a reasonably large number here.
1646 SmallString<1024> expanded;
1647 if (!fs::real_path(config->osoPrefix, expanded,
1648 /*expand_tilde=*/true)) {
1649 // Note: LD64 expands "." to be `<current_dir>/`
1650 // (ie., it has a slash suffix) whereas real_path() doesn't.
1651 // So we have to append '/' to be consistent.
1652 StringRef sep = sys::path::get_separator();
1653 // real_path removes trailing slashes as part of the normalization, but
1654 // these are meaningful for our text based stripping
1655 if (config->osoPrefix == "." || config->osoPrefix.ends_with(sep))
1656 expanded += sep;
1657 config->osoPrefix = saver().save(expanded.str());
1658 }
1659 }
1660
1661 bool pie = args.hasFlag(OPT_pie, OPT_no_pie, true);
1662 if (!supportsNoPie() && !pie) {
1663 warn("-no_pie ignored for arm64");
1664 pie = true;
1665 }
1666
1667 config->isPic = config->outputType == MH_DYLIB ||
1668 config->outputType == MH_BUNDLE ||
1669 (config->outputType == MH_EXECUTE && pie);
1670
1671 // Must be set before any InputSections and Symbols are created.
1672 config->deadStrip = args.hasArg(OPT_dead_strip);
1673 config->interposable = args.hasArg(OPT_interposable);
1674
1675 config->systemLibraryRoots = getSystemLibraryRoots(args);
1676 if (const char *path = getReproduceOption(args)) {
1677 // Note that --reproduce is a debug option so you can ignore it
1678 // if you are trying to understand the whole picture of the code.
1679 Expected<std::unique_ptr<TarWriter>> errOrWriter =
1680 TarWriter::create(path, path::stem(path));
1681 if (errOrWriter) {
1682 tar = std::move(*errOrWriter);
1683 tar->append("response.txt", createResponseFile(args));
1684 tar->append("version.txt", getLLDVersion() + "\n");
1685 } else {
1686 error("--reproduce: " + toString(errOrWriter.takeError()));
1687 }
1688 }
1689
1690 if (auto *arg = args.getLastArg(OPT_threads_eq)) {
1691 StringRef v(arg->getValue());
1692 unsigned threads = 0;
1693 if (!llvm::to_integer(v, threads, 0) || threads == 0)
1694 error(arg->getSpelling() + ": expected a positive integer, but got '" +
1695 arg->getValue() + "'");
1696 parallel::strategy = hardware_concurrency(threads);
1697 config->thinLTOJobs = v;
1698 }
1699 if (auto *arg = args.getLastArg(OPT_thinlto_jobs_eq))
1700 config->thinLTOJobs = arg->getValue();
1701 if (!get_threadpool_strategy(config->thinLTOJobs))
1702 error("--thinlto-jobs: invalid job count: " + config->thinLTOJobs);
1703
1704 for (const Arg *arg : args.filtered(OPT_u)) {
1705 config->explicitUndefineds.push_back(symtab->addUndefined(
1706 arg->getValue(), /*file=*/nullptr, /*isWeakRef=*/false));
1707 }
1708
1709 for (const Arg *arg : args.filtered(OPT_U))
1710 config->explicitDynamicLookups.insert(arg->getValue());
1711
1712 config->mapFile = args.getLastArgValue(OPT_map);
1713 config->optimize = args::getInteger(args, OPT_O, 1);
1714 config->outputFile = args.getLastArgValue(OPT_o, "a.out");
1715 config->finalOutput =
1716 args.getLastArgValue(OPT_final_output, config->outputFile);
1717 config->astPaths = args.getAllArgValues(OPT_add_ast_path);
1718 config->headerPad = args::getHex(args, OPT_headerpad, /*Default=*/32);
1719 config->headerPadMaxInstallNames =
1720 args.hasArg(OPT_headerpad_max_install_names);
1721 config->printDylibSearch =
1722 args.hasArg(OPT_print_dylib_search) || getenv("RC_TRACE_DYLIB_SEARCHING");
1723 config->printEachFile = args.hasArg(OPT_t);
1724 config->printWhyLoad = args.hasArg(OPT_why_load);
1725 config->omitDebugInfo = args.hasArg(OPT_S);
1726 config->errorForArchMismatch = args.hasArg(OPT_arch_errors_fatal);
1727 if (const Arg *arg = args.getLastArg(OPT_bundle_loader)) {
1728 if (config->outputType != MH_BUNDLE)
1729 error("-bundle_loader can only be used with MachO bundle output");
1730 addFile(arg->getValue(), LoadType::CommandLine, /*isLazy=*/false,
1731 /*isExplicit=*/false, /*isBundleLoader=*/true);
1732 }
1733 for (auto *arg : args.filtered(OPT_dyld_env)) {
1734 StringRef envPair(arg->getValue());
1735 if (!envPair.contains('='))
1736 error("-dyld_env's argument is malformed. Expected "
1737 "-dyld_env <ENV_VAR>=<VALUE>, got `" +
1738 envPair + "`");
1739 config->dyldEnvs.push_back(envPair);
1740 }
1741 if (!config->dyldEnvs.empty() && config->outputType != MH_EXECUTE)
1742 error("-dyld_env can only be used when creating executable output");
1743
1744 if (const Arg *arg = args.getLastArg(OPT_umbrella)) {
1745 if (config->outputType != MH_DYLIB)
1746 warn("-umbrella used, but not creating dylib");
1747 config->umbrella = arg->getValue();
1748 }
1749 config->ltoObjPath = args.getLastArgValue(OPT_object_path_lto);
1750 config->ltoNewPmPasses = args.getLastArgValue(OPT_lto_newpm_passes);
1751 config->thinLTOCacheDir = args.getLastArgValue(OPT_cache_path_lto);
1752 config->thinLTOCachePolicy = getLTOCachePolicy(args);
1753 config->thinLTOEmitImportsFiles = args.hasArg(OPT_thinlto_emit_imports_files);
1754 config->thinLTOEmitIndexFiles = args.hasArg(OPT_thinlto_emit_index_files) ||
1755 args.hasArg(OPT_thinlto_index_only) ||
1756 args.hasArg(OPT_thinlto_index_only_eq);
1757 config->thinLTOIndexOnly = args.hasArg(OPT_thinlto_index_only) ||
1758 args.hasArg(OPT_thinlto_index_only_eq);
1759 config->thinLTOIndexOnlyArg = args.getLastArgValue(OPT_thinlto_index_only_eq);
1760 config->thinLTOObjectSuffixReplace =
1761 getOldNewOptions(args, OPT_thinlto_object_suffix_replace_eq);
1762 std::tie(config->thinLTOPrefixReplaceOld, config->thinLTOPrefixReplaceNew,
1763 config->thinLTOPrefixReplaceNativeObject) =
1764 getOldNewOptionsExtra(args, OPT_thinlto_prefix_replace_eq);
1765 if (config->thinLTOEmitIndexFiles && !config->thinLTOIndexOnly) {
1766 if (args.hasArg(OPT_thinlto_object_suffix_replace_eq))
1767 error("--thinlto-object-suffix-replace is not supported with "
1768 "--thinlto-emit-index-files");
1769 else if (args.hasArg(OPT_thinlto_prefix_replace_eq))
1770 error("--thinlto-prefix-replace is not supported with "
1771 "--thinlto-emit-index-files");
1772 }
1773 if (!config->thinLTOPrefixReplaceNativeObject.empty() &&
1774 config->thinLTOIndexOnlyArg.empty()) {
1775 error("--thinlto-prefix-replace=old_dir;new_dir;obj_dir must be used with "
1776 "--thinlto-index-only=");
1777 }
1778 config->warnDuplicateRpath =
1779 args.hasFlag(OPT_warn_duplicate_rpath, OPT_no_warn_duplicate_rpath, true);
1780 config->runtimePaths = getRuntimePaths(args);
1781 config->allowableClients = getAllowableClients(args);
1782 config->allLoad = args.hasFlag(OPT_all_load, OPT_noall_load, false);
1783 config->archMultiple = args.hasArg(OPT_arch_multiple);
1784 config->applicationExtension = args.hasFlag(
1785 OPT_application_extension, OPT_no_application_extension, false);
1786 config->exportDynamic = args.hasArg(OPT_export_dynamic);
1787 config->forceLoadObjC = args.hasArg(OPT_ObjC);
1788 config->forceLoadSwift = args.hasArg(OPT_force_load_swift_libs);
1789 config->deadStripDylibs = args.hasArg(OPT_dead_strip_dylibs);
1790 config->demangle = args.hasArg(OPT_demangle);
1791 config->implicitDylibs = !args.hasArg(OPT_no_implicit_dylibs);
1792 config->emitFunctionStarts =
1793 args.hasFlag(OPT_function_starts, OPT_no_function_starts, true);
1794 config->emitDataInCodeInfo =
1795 args.hasFlag(OPT_data_in_code_info, OPT_no_data_in_code_info, true);
1796 config->emitChainedFixups = shouldEmitChainedFixups(args);
1797 config->emitInitOffsets =
1798 config->emitChainedFixups || args.hasArg(OPT_init_offsets);
1799 config->emitRelativeMethodLists = shouldEmitRelativeMethodLists(args);
1800 config->icfLevel = getICFLevel(args);
1801 config->keepICFStabs = args.hasArg(OPT_keep_icf_stabs);
1802 config->dedupStrings =
1803 args.hasFlag(OPT_deduplicate_strings, OPT_no_deduplicate_strings, true);
1804 config->dedupSymbolStrings = !args.hasArg(OPT_no_deduplicate_symbol_strings);
1805 config->deadStripDuplicates = args.hasArg(OPT_dead_strip_duplicates);
1806 config->warnDylibInstallName = args.hasFlag(
1807 OPT_warn_dylib_install_name, OPT_no_warn_dylib_install_name, false);
1808 config->ignoreOptimizationHints = args.hasArg(OPT_ignore_optimization_hints);
1809 config->callGraphProfileSort = args.hasFlag(
1810 OPT_call_graph_profile_sort, OPT_no_call_graph_profile_sort, true);
1811 config->printSymbolOrder = args.getLastArgValue(OPT_print_symbol_order_eq);
1812 config->forceExactCpuSubtypeMatch =
1813 getenv("LD_DYLIB_CPU_SUBTYPES_MUST_MATCH");
1814 config->objcStubsMode = getObjCStubsMode(args);
1815 config->ignoreAutoLink = args.hasArg(OPT_ignore_auto_link);
1816 for (const Arg *arg : args.filtered(OPT_ignore_auto_link_option))
1817 config->ignoreAutoLinkOptions.insert(arg->getValue());
1818 config->strictAutoLink = args.hasArg(OPT_strict_auto_link);
1819 config->ltoDebugPassManager = args.hasArg(OPT_lto_debug_pass_manager);
1820 config->codegenDataGeneratePath =
1821 args.getLastArgValue(OPT_codegen_data_generate_path);
1822 config->csProfileGenerate = args.hasArg(OPT_cs_profile_generate);
1823 config->csProfilePath = args.getLastArgValue(OPT_cs_profile_path);
1824 config->pgoWarnMismatch =
1825 args.hasFlag(OPT_pgo_warn_mismatch, OPT_no_pgo_warn_mismatch, true);
1826 config->warnThinArchiveMissingMembers =
1827 args.hasFlag(OPT_warn_thin_archive_missing_members,
1828 OPT_no_warn_thin_archive_missing_members, true);
1829 config->generateUuid = !args.hasArg(OPT_no_uuid);
1830 config->disableVerify = args.hasArg(OPT_disable_verify);
1831
1832 auto IncompatWithCGSort = [&](StringRef firstArgStr) {
1833 // Throw an error only if --call-graph-profile-sort is explicitly specified
1834 if (config->callGraphProfileSort)
1835 if (const Arg *arg = args.getLastArgNoClaim(OPT_call_graph_profile_sort))
1836 error(firstArgStr + " is incompatible with " + arg->getSpelling());
1837 };
1838 if (args.hasArg(OPT_irpgo_profile_sort) ||
1839 args.hasArg(OPT_irpgo_profile_sort_eq))
1840 warn("--irpgo-profile-sort is deprecated. Please use "
1841 "--bp-startup-sort=function");
1842 if (const Arg *arg = args.getLastArg(OPT_irpgo_profile))
1843 config->irpgoProfilePath = arg->getValue();
1844
1845 if (const Arg *arg = args.getLastArg(OPT_irpgo_profile_sort)) {
1846 config->irpgoProfilePath = arg->getValue();
1847 config->bpStartupFunctionSort = true;
1848 IncompatWithCGSort(arg->getSpelling());
1849 }
1850 config->bpCompressionSortStartupFunctions =
1851 args.hasFlag(OPT_bp_compression_sort_startup_functions,
1852 OPT_no_bp_compression_sort_startup_functions, false);
1853 if (const Arg *arg = args.getLastArg(OPT_bp_startup_sort)) {
1854 StringRef startupSortStr = arg->getValue();
1855 if (startupSortStr == "function") {
1856 config->bpStartupFunctionSort = true;
1857 } else if (startupSortStr != "none") {
1858 error("unknown value `" + startupSortStr + "` for " + arg->getSpelling());
1859 }
1860 if (startupSortStr != "none")
1861 IncompatWithCGSort(arg->getSpelling());
1862 }
1863 if (!config->bpStartupFunctionSort &&
1864 config->bpCompressionSortStartupFunctions)
1865 error("--bp-compression-sort-startup-functions must be used with "
1866 "--bp-startup-sort=function");
1867 if (config->irpgoProfilePath.empty() && config->bpStartupFunctionSort)
1868 error("--bp-startup-sort=function must be used with "
1869 "--irpgo-profile");
1870 if (const Arg *arg = args.getLastArg(OPT_bp_compression_sort)) {
1871 StringRef compressionSortStr = arg->getValue();
1872 if (compressionSortStr == "function") {
1873 config->bpFunctionOrderForCompression = true;
1874 } else if (compressionSortStr == "data") {
1875 config->bpDataOrderForCompression = true;
1876 } else if (compressionSortStr == "both") {
1877 config->bpFunctionOrderForCompression = true;
1878 config->bpDataOrderForCompression = true;
1879 } else if (compressionSortStr != "none") {
1880 error("unknown value `" + compressionSortStr + "` for " +
1881 arg->getSpelling());
1882 }
1883 if (compressionSortStr != "none")
1884 IncompatWithCGSort(arg->getSpelling());
1885 }
1886 config->bpVerboseSectionOrderer = args.hasArg(OPT_verbose_bp_section_orderer);
1887
1888 for (const Arg *arg : args.filtered(OPT_alias)) {
1889 config->aliasedSymbols.push_back(
1890 std::make_pair(arg->getValue(0), arg->getValue(1)));
1891 }
1892
1893 if (const char *zero = getenv("ZERO_AR_DATE"))
1894 config->zeroModTime = strcmp(zero, "0") != 0;
1895 if (args.getLastArg(OPT_reproducible))
1896 config->zeroModTime = true;
1897
1898 std::array<PlatformType, 4> encryptablePlatforms{
1899 PLATFORM_IOS, PLATFORM_WATCHOS, PLATFORM_TVOS, PLATFORM_XROS};
1900 config->emitEncryptionInfo =
1901 args.hasFlag(OPT_encryptable, OPT_no_encryption,
1902 is_contained(encryptablePlatforms, config->platform()));
1903
1904 if (const Arg *arg = args.getLastArg(OPT_install_name)) {
1905 if (config->warnDylibInstallName && config->outputType != MH_DYLIB)
1906 warn(
1907 arg->getAsString(args) +
1908 ": ignored, only has effect with -dylib [--warn-dylib-install-name]");
1909 else
1910 config->installName = arg->getValue();
1911 } else if (config->outputType == MH_DYLIB) {
1912 config->installName = config->finalOutput;
1913 }
1914
1915 auto getClientName = [&]() {
1916 StringRef cn = path::filename(config->finalOutput);
1917 cn.consume_front("lib");
1918 auto firstDotOrUnderscore = cn.find_first_of("._");
1919 cn = cn.take_front(firstDotOrUnderscore);
1920 return cn;
1921 };
1922 config->clientName = args.getLastArgValue(OPT_client_name, getClientName());
1923
1924 if (args.hasArg(OPT_mark_dead_strippable_dylib)) {
1925 if (config->outputType != MH_DYLIB)
1926 warn("-mark_dead_strippable_dylib: ignored, only has effect with -dylib");
1927 else
1928 config->markDeadStrippableDylib = true;
1929 }
1930
1931 if (const Arg *arg = args.getLastArg(OPT_static, OPT_dynamic))
1932 config->staticLink = (arg->getOption().getID() == OPT_static);
1933
1934 if (const Arg *arg =
1935 args.getLastArg(OPT_flat_namespace, OPT_twolevel_namespace))
1936 config->namespaceKind = arg->getOption().getID() == OPT_twolevel_namespace
1937 ? NamespaceKind::twolevel
1938 : NamespaceKind::flat;
1939
1940 config->undefinedSymbolTreatment = getUndefinedSymbolTreatment(args);
1941
1942 if (config->outputType == MH_EXECUTE)
1943 config->entry = symtab->addUndefined(args.getLastArgValue(OPT_e, "_main"),
1944 /*file=*/nullptr,
1945 /*isWeakRef=*/false);
1946
1947 config->librarySearchPaths =
1948 getLibrarySearchPaths(args, config->systemLibraryRoots);
1949 config->frameworkSearchPaths =
1950 getFrameworkSearchPaths(args, config->systemLibraryRoots);
1951 if (const Arg *arg =
1952 args.getLastArg(OPT_search_paths_first, OPT_search_dylibs_first))
1953 config->searchDylibsFirst =
1954 arg->getOption().getID() == OPT_search_dylibs_first;
1955
1956 config->dylibCompatibilityVersion =
1957 parseDylibVersion(args, OPT_compatibility_version);
1958 config->dylibCurrentVersion = parseDylibVersion(args, OPT_current_version);
1959
1960 config->dataConst =
1961 args.hasFlag(OPT_data_const, OPT_no_data_const, dataConstDefault(args));
1962 // Populate config->sectionRenameMap with builtin default renames.
1963 // Options -rename_section and -rename_segment are able to override.
1964 initializeSectionRenameMap();
1965 // Reject every special character except '.' and '$'
1966 // TODO(gkm): verify that this is the proper set of invalid chars
1967 StringRef invalidNameChars("!\"#%&'()*+,-/:;<=>?@[\\]^`{|}~");
1968 auto validName = [invalidNameChars](StringRef s) {
1969 if (s.find_first_of(invalidNameChars) != StringRef::npos)
1970 error("invalid name for segment or section: " + s);
1971 return s;
1972 };
1973 for (const Arg *arg : args.filtered(OPT_rename_section)) {
1974 config->sectionRenameMap[{validName(arg->getValue(0)),
1975 validName(arg->getValue(1))}] = {
1976 validName(arg->getValue(2)), validName(arg->getValue(3))};
1977 }
1978 for (const Arg *arg : args.filtered(OPT_rename_segment)) {
1979 config->segmentRenameMap[validName(arg->getValue(0))] =
1980 validName(arg->getValue(1));
1981 }
1982
1983 config->sectionAlignments = parseSectAlign(args);
1984
1985 for (const Arg *arg : args.filtered(OPT_segprot)) {
1986 StringRef segName = arg->getValue(0);
1987 uint32_t maxProt = parseProtection(arg->getValue(1));
1988 uint32_t initProt = parseProtection(arg->getValue(2));
1989
1990 // FIXME: Check if this works on more platforms.
1991 bool allowsDifferentInitAndMaxProt =
1992 config->platform() == PLATFORM_MACOS ||
1993 config->platform() == PLATFORM_MACCATALYST;
1994 if (allowsDifferentInitAndMaxProt) {
1995 if (initProt > maxProt)
1996 error("invalid argument '" + arg->getAsString(args) +
1997 "': init must not be more permissive than max");
1998 } else {
1999 if (maxProt != initProt && config->arch() != AK_i386)
2000 error("invalid argument '" + arg->getAsString(args) +
2001 "': max and init must be the same for non-macOS non-i386 archs");
2002 }
2003
2004 if (segName == segment_names::linkEdit)
2005 error("-segprot cannot be used to change __LINKEDIT's protections");
2006 config->segmentProtections.push_back({segName, maxProt, initProt});
2007 }
2008
2009 config->hasExplicitExports =
2010 args.hasArg(OPT_no_exported_symbols) ||
2011 args.hasArgNoClaim(OPT_exported_symbol, OPT_exported_symbols_list);
2012 handleSymbolPatterns(args, config->exportedSymbols, OPT_exported_symbol,
2013 OPT_exported_symbols_list);
2014 handleSymbolPatterns(args, config->unexportedSymbols, OPT_unexported_symbol,
2015 OPT_unexported_symbols_list);
2016 if (config->hasExplicitExports && !config->unexportedSymbols.empty())
2017 error("cannot use both -exported_symbol* and -unexported_symbol* options");
2018
2019 if (args.hasArg(OPT_no_exported_symbols) && !config->exportedSymbols.empty())
2020 error("cannot use both -exported_symbol* and -no_exported_symbols options");
2021
2022 // Imitating LD64's:
2023 // -non_global_symbols_no_strip_list and -non_global_symbols_strip_list can't
2024 // both be present.
2025 // But -x can be used with either of these two, in which case, the last arg
2026 // takes effect.
2027 // (TODO: This is kind of confusing - considering disallowing using them
2028 // together for a more straightforward behaviour)
2029 {
2030 bool includeLocal = false;
2031 bool excludeLocal = false;
2032 for (const Arg *arg :
2033 args.filtered(OPT_x, OPT_non_global_symbols_no_strip_list,
2034 OPT_non_global_symbols_strip_list)) {
2035 switch (arg->getOption().getID()) {
2036 case OPT_x:
2037 config->localSymbolsPresence = SymtabPresence::None;
2038 break;
2039 case OPT_non_global_symbols_no_strip_list:
2040 if (excludeLocal) {
2041 error("cannot use both -non_global_symbols_no_strip_list and "
2042 "-non_global_symbols_strip_list");
2043 } else {
2044 includeLocal = true;
2045 config->localSymbolsPresence = SymtabPresence::SelectivelyIncluded;
2046 parseSymbolPatternsFile(arg, config->localSymbolPatterns);
2047 }
2048 break;
2049 case OPT_non_global_symbols_strip_list:
2050 if (includeLocal) {
2051 error("cannot use both -non_global_symbols_no_strip_list and "
2052 "-non_global_symbols_strip_list");
2053 } else {
2054 excludeLocal = true;
2055 config->localSymbolsPresence = SymtabPresence::SelectivelyExcluded;
2056 parseSymbolPatternsFile(arg, config->localSymbolPatterns);
2057 }
2058 break;
2059 default:
2060 llvm_unreachable("unexpected option");
2061 }
2062 }
2063 }
2064 // Explicitly-exported literal symbols must be defined, but might
2065 // languish in an archive if unreferenced elsewhere or if they are in the
2066 // non-global strip list. Light a fire under those lazy symbols!
2067 for (const CachedHashStringRef &cachedName : config->exportedSymbols.literals)
2068 symtab->addUndefined(cachedName.val(), /*file=*/nullptr,
2069 /*isWeakRef=*/false);
2070
2071 for (const Arg *arg : args.filtered(OPT_why_live))
2072 config->whyLive.insert(arg->getValue());
2073 if (!config->whyLive.empty() && !config->deadStrip)
2074 warn("-why_live has no effect without -dead_strip, ignoring");
2075
2076 config->saveTemps = args.hasArg(OPT_save_temps);
2077
2078 config->adhocCodesign = args.hasFlag(
2079 OPT_adhoc_codesign, OPT_no_adhoc_codesign,
2080 shouldAdhocSignByDefault(config->arch(), config->platform()));
2081
2082 if (args.hasArg(OPT_v)) {
2083 message(getLLDVersion(), ctx->e.errs());
2084 message(StringRef("Library search paths:") +
2085 (config->librarySearchPaths.empty()
2086 ? ""
2087 : "\n\t" + join(config->librarySearchPaths, "\n\t")),
2088 ctx->e.errs());
2089 message(StringRef("Framework search paths:") +
2090 (config->frameworkSearchPaths.empty()
2091 ? ""
2092 : "\n\t" + join(config->frameworkSearchPaths, "\n\t")),
2093 ctx->e.errs());
2094 }
2095
2096 config->progName = argsArr[0];
2097
2098 config->timeTraceEnabled = args.hasArg(OPT_time_trace_eq);
2099 config->timeTraceGranularity =
2100 args::getInteger(args, OPT_time_trace_granularity_eq, 500);
2101
2102 // Initialize time trace profiler.
2103 if (config->timeTraceEnabled)
2104 timeTraceProfilerInitialize(config->timeTraceGranularity, config->progName);
2105
2106 {
2107 TimeTraceScope timeScope("ExecuteLinker");
2108
2109 initLLVM(); // must be run before any call to addFile()
2110 createFiles(args);
2111
2112 // Now that all dylibs have been loaded, search for those that should be
2113 // re-exported.
2114 {
2115 auto reexportHandler = [](const Arg *arg,
2116 const std::vector<StringRef> &extensions) {
2117 config->hasReexports = true;
2118 StringRef searchName = arg->getValue();
2119 if (!markReexport(searchName, extensions))
2120 error(arg->getSpelling() + " " + searchName +
2121 " does not match a supplied dylib");
2122 };
2123 std::vector<StringRef> extensions = {".tbd"};
2124 for (const Arg *arg : args.filtered(OPT_sub_umbrella))
2125 reexportHandler(arg, extensions);
2126
2127 extensions.push_back(".dylib");
2128 for (const Arg *arg : args.filtered(OPT_sub_library))
2129 reexportHandler(arg, extensions);
2130 }
2131
2132 cl::ResetAllOptionOccurrences();
2133
2134 // Parse LTO options.
2135 if (const Arg *arg = args.getLastArg(OPT_mcpu))
2136 parseClangOption(saver().save("-mcpu=" + StringRef(arg->getValue())),
2137 arg->getSpelling());
2138
2139 for (const Arg *arg : args.filtered(OPT_mllvm)) {
2140 parseClangOption(arg->getValue(), arg->getSpelling());
2141 config->mllvmOpts.emplace_back(arg->getValue());
2142 }
2143
2144 config->passPlugins = args::getStrings(args, OPT_load_pass_plugins);
2145
2146 createSyntheticSections();
2147 createSyntheticSymbols();
2148 addSynthenticMethnames();
2149
2150 createAliases();
2151 // If we are in "explicit exports" mode, hide everything that isn't
2152 // explicitly exported. Do this before running LTO so that LTO can better
2153 // optimize.
2154 handleExplicitExports();
2155
2156 bool didCompileBitcodeFiles = compileBitcodeFiles();
2157
2158 resolveLCLinkerOptions();
2159
2160 // If --thinlto-index-only is given, we should create only "index
2161 // files" and not object files. Index file creation is already done
2162 // in compileBitcodeFiles, so we are done if that's the case.
2163 if (config->thinLTOIndexOnly)
2164 return errorCount() == 0;
2165
2166 // LTO may emit a non-hidden (extern) object file symbol even if the
2167 // corresponding bitcode symbol is hidden. In particular, this happens for
2168 // cross-module references to hidden symbols under ThinLTO. Thus, if we
2169 // compiled any bitcode files, we must redo the symbol hiding.
2170 if (didCompileBitcodeFiles)
2171 handleExplicitExports();
2172 replaceCommonSymbols();
2173
2174 StringRef orderFile = args.getLastArgValue(OPT_order_file);
2175 if (!orderFile.empty())
2176 priorityBuilder.parseOrderFile(orderFile);
2177
2178 referenceStubBinder();
2179
2180 // FIXME: should terminate the link early based on errors encountered so
2181 // far?
2182
2183 for (const Arg *arg : args.filtered(OPT_sectcreate)) {
2184 StringRef segName = arg->getValue(0);
2185 StringRef sectName = arg->getValue(1);
2186 StringRef fileName = arg->getValue(2);
2187 std::optional<MemoryBufferRef> buffer = readFile(fileName);
2188 if (buffer)
2189 inputFiles.insert(make<OpaqueFile>(*buffer, segName, sectName));
2190 }
2191
2192 for (const Arg *arg : args.filtered(OPT_add_empty_section)) {
2193 StringRef segName = arg->getValue(0);
2194 StringRef sectName = arg->getValue(1);
2195 inputFiles.insert(make<OpaqueFile>(MemoryBufferRef(), segName, sectName));
2196 }
2197
2198 gatherInputSections();
2199
2200 if (!config->codegenDataGeneratePath.empty())
2201 codegenDataGenerate();
2202
2203 if (config->callGraphProfileSort)
2204 priorityBuilder.extractCallGraphProfile();
2205
2206 if (config->deadStrip)
2207 markLive();
2208
2209 // Ensure that no symbols point inside __mod_init_func sections if they are
2210 // removed due to -init_offsets. This must run after dead stripping.
2211 if (config->emitInitOffsets)
2212 eraseInitializerSymbols();
2213
2214 // Categories are not subject to dead-strip. The __objc_catlist section is
2215 // marked as NO_DEAD_STRIP and that propagates into all category data.
2216 if (args.hasArg(OPT_check_category_conflicts))
2217 objc::checkCategories();
2218
2219 // Category merging uses "->live = false" to erase old category data, so
2220 // it has to run after dead-stripping (markLive).
2221 if (args.hasFlag(OPT_objc_category_merging, OPT_no_objc_category_merging,
2222 false))
2223 objc::mergeCategories();
2224
2225 // ICF assumes that all literals have been folded already, so we must run
2226 // foldIdenticalLiterals before foldIdenticalSections.
2227 foldIdenticalLiterals();
2228 if (config->icfLevel != ICFLevel::none) {
2229 if (config->icfLevel == ICFLevel::safe ||
2230 config->icfLevel == ICFLevel::safe_thunks)
2231 markAddrSigSymbols();
2232 foldIdenticalSections(/*onlyCfStrings=*/false);
2233 } else if (config->dedupStrings) {
2234 foldIdenticalSections(/*onlyCfStrings=*/true);
2235 }
2236
2237 // Write to an output file.
2238 if (target->wordSize == 8)
2239 writeResult<LP64>();
2240 else
2241 writeResult<ILP32>();
2242
2243 depTracker->write(getLLDVersion(), inputFiles, config->outputFile);
2244 }
2245
2246 if (config->timeTraceEnabled) {
2247 checkError(timeTraceProfilerWrite(
2248 args.getLastArgValue(OPT_time_trace_eq).str(), config->outputFile));
2249
2250 timeTraceProfilerCleanup();
2251 }
2252
2253 if (errorCount() != 0 || config->strictAutoLink)
2254 for (const auto &warning : missingAutolinkWarnings)
2255 warn(warning);
2256
2257 return errorCount() == 0;
2258 }
2259 } // namespace macho
2260 } // namespace lld
2261