1 //===- dsymutil.cpp - Debug info dumping utility for llvm -----------------===//
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 // This program is a utility that aims to be a dropin replacement for Darwin's
10 // dsymutil.
11 //===----------------------------------------------------------------------===//
12 
13 #include "dsymutil.h"
14 #include "BinaryHolder.h"
15 #include "CFBundle.h"
16 #include "DebugMap.h"
17 #include "LinkUtils.h"
18 #include "MachOUtils.h"
19 #include "Reproducer.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/StringRef.h"
25 #include "llvm/ADT/Triple.h"
26 #include "llvm/DebugInfo/DIContext.h"
27 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
28 #include "llvm/DebugInfo/DWARF/DWARFVerifier.h"
29 #include "llvm/Object/Binary.h"
30 #include "llvm/Object/MachO.h"
31 #include "llvm/Option/Arg.h"
32 #include "llvm/Option/ArgList.h"
33 #include "llvm/Option/Option.h"
34 #include "llvm/Support/CommandLine.h"
35 #include "llvm/Support/FileCollector.h"
36 #include "llvm/Support/FileSystem.h"
37 #include "llvm/Support/InitLLVM.h"
38 #include "llvm/Support/ManagedStatic.h"
39 #include "llvm/Support/Path.h"
40 #include "llvm/Support/TargetSelect.h"
41 #include "llvm/Support/ThreadPool.h"
42 #include "llvm/Support/WithColor.h"
43 #include "llvm/Support/raw_ostream.h"
44 #include "llvm/Support/thread.h"
45 #include <algorithm>
46 #include <cstdint>
47 #include <cstdlib>
48 #include <string>
49 #include <system_error>
50 
51 using namespace llvm;
52 using namespace llvm::dsymutil;
53 using namespace object;
54 
55 namespace {
56 enum ID {
57   OPT_INVALID = 0, // This is not an option ID.
58 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
59                HELPTEXT, METAVAR, VALUES)                                      \
60   OPT_##ID,
61 #include "Options.inc"
62 #undef OPTION
63 };
64 
65 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
66 #include "Options.inc"
67 #undef PREFIX
68 
69 const opt::OptTable::Info InfoTable[] = {
70 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
71                HELPTEXT, METAVAR, VALUES)                                      \
72   {                                                                            \
73       PREFIX,      NAME,      HELPTEXT,                                        \
74       METAVAR,     OPT_##ID,  opt::Option::KIND##Class,                        \
75       PARAM,       FLAGS,     OPT_##GROUP,                                     \
76       OPT_##ALIAS, ALIASARGS, VALUES},
77 #include "Options.inc"
78 #undef OPTION
79 };
80 
81 class DsymutilOptTable : public opt::OptTable {
82 public:
83   DsymutilOptTable() : OptTable(InfoTable) {}
84 };
85 } // namespace
86 
87 struct DsymutilOptions {
88   bool DumpDebugMap = false;
89   bool DumpStab = false;
90   bool Flat = false;
91   bool InputIsYAMLDebugMap = false;
92   bool PaperTrailWarnings = false;
93   bool Verify = false;
94   std::string SymbolMap;
95   std::string OutputFile;
96   std::string Toolchain;
97   std::string ReproducerPath;
98   std::vector<std::string> Archs;
99   std::vector<std::string> InputFiles;
100   unsigned NumThreads;
101   ReproducerMode ReproMode = ReproducerMode::Off;
102   dsymutil::LinkOptions LinkOpts;
103 };
104 
105 /// Return a list of input files. This function has logic for dealing with the
106 /// special case where we might have dSYM bundles as input. The function
107 /// returns an error when the directory structure doesn't match that of a dSYM
108 /// bundle.
109 static Expected<std::vector<std::string>> getInputs(opt::InputArgList &Args,
110                                                     bool DsymAsInput) {
111   std::vector<std::string> InputFiles;
112   for (auto *File : Args.filtered(OPT_INPUT))
113     InputFiles.push_back(File->getValue());
114 
115   if (!DsymAsInput)
116     return InputFiles;
117 
118   // If we are updating, we might get dSYM bundles as input.
119   std::vector<std::string> Inputs;
120   for (const auto &Input : InputFiles) {
121     if (!sys::fs::is_directory(Input)) {
122       Inputs.push_back(Input);
123       continue;
124     }
125 
126     // Make sure that we're dealing with a dSYM bundle.
127     SmallString<256> BundlePath(Input);
128     sys::path::append(BundlePath, "Contents", "Resources", "DWARF");
129     if (!sys::fs::is_directory(BundlePath))
130       return make_error<StringError>(
131           Input + " is a directory, but doesn't look like a dSYM bundle.",
132           inconvertibleErrorCode());
133 
134     // Create a directory iterator to iterate over all the entries in the
135     // bundle.
136     std::error_code EC;
137     sys::fs::directory_iterator DirIt(BundlePath, EC);
138     sys::fs::directory_iterator DirEnd;
139     if (EC)
140       return errorCodeToError(EC);
141 
142     // Add each entry to the list of inputs.
143     while (DirIt != DirEnd) {
144       Inputs.push_back(DirIt->path());
145       DirIt.increment(EC);
146       if (EC)
147         return errorCodeToError(EC);
148     }
149   }
150   return Inputs;
151 }
152 
153 // Verify that the given combination of options makes sense.
154 static Error verifyOptions(const DsymutilOptions &Options) {
155   if (Options.InputFiles.empty()) {
156     return make_error<StringError>("no input files specified",
157                                    errc::invalid_argument);
158   }
159 
160   if (Options.LinkOpts.Update && llvm::is_contained(Options.InputFiles, "-")) {
161     // FIXME: We cannot use stdin for an update because stdin will be
162     // consumed by the BinaryHolder during the debugmap parsing, and
163     // then we will want to consume it again in DwarfLinker. If we
164     // used a unique BinaryHolder object that could cache multiple
165     // binaries this restriction would go away.
166     return make_error<StringError>(
167         "standard input cannot be used as input for a dSYM update.",
168         errc::invalid_argument);
169   }
170 
171   if (!Options.Flat && Options.OutputFile == "-")
172     return make_error<StringError>(
173         "cannot emit to standard output without --flat.",
174         errc::invalid_argument);
175 
176   if (Options.InputFiles.size() > 1 && Options.Flat &&
177       !Options.OutputFile.empty())
178     return make_error<StringError>(
179         "cannot use -o with multiple inputs in flat mode.",
180         errc::invalid_argument);
181 
182   if (Options.PaperTrailWarnings && Options.InputIsYAMLDebugMap)
183     return make_error<StringError>(
184         "paper trail warnings are not supported for YAML input.",
185         errc::invalid_argument);
186 
187   if (!Options.ReproducerPath.empty() &&
188       Options.ReproMode != ReproducerMode::Use)
189     return make_error<StringError>(
190         "cannot combine --gen-reproducer and --use-reproducer.",
191         errc::invalid_argument);
192 
193   return Error::success();
194 }
195 
196 static Expected<AccelTableKind> getAccelTableKind(opt::InputArgList &Args) {
197   if (opt::Arg *Accelerator = Args.getLastArg(OPT_accelerator)) {
198     StringRef S = Accelerator->getValue();
199     if (S == "Apple")
200       return AccelTableKind::Apple;
201     if (S == "Dwarf")
202       return AccelTableKind::Dwarf;
203     if (S == "Default")
204       return AccelTableKind::Default;
205     return make_error<StringError>(
206         "invalid accelerator type specified: '" + S +
207             "'. Support values are 'Apple', 'Dwarf' and 'Default'.",
208         inconvertibleErrorCode());
209   }
210   return AccelTableKind::Default;
211 }
212 
213 /// Parses the command line options into the LinkOptions struct and performs
214 /// some sanity checking. Returns an error in case the latter fails.
215 static Expected<DsymutilOptions> getOptions(opt::InputArgList &Args) {
216   DsymutilOptions Options;
217 
218   Options.DumpDebugMap = Args.hasArg(OPT_dump_debug_map);
219   Options.DumpStab = Args.hasArg(OPT_symtab);
220   Options.Flat = Args.hasArg(OPT_flat);
221   Options.InputIsYAMLDebugMap = Args.hasArg(OPT_yaml_input);
222   Options.PaperTrailWarnings = Args.hasArg(OPT_papertrail);
223   Options.Verify = Args.hasArg(OPT_verify);
224 
225   Options.LinkOpts.Minimize = Args.hasArg(OPT_minimize);
226   Options.LinkOpts.NoODR = Args.hasArg(OPT_no_odr);
227   Options.LinkOpts.NoOutput = Args.hasArg(OPT_no_output);
228   Options.LinkOpts.NoTimestamp = Args.hasArg(OPT_no_swiftmodule_timestamp);
229   Options.LinkOpts.Update = Args.hasArg(OPT_update);
230   Options.LinkOpts.Verbose = Args.hasArg(OPT_verbose);
231   Options.LinkOpts.Statistics = Args.hasArg(OPT_statistics);
232 
233   if (opt::Arg *ReproducerPath = Args.getLastArg(OPT_use_reproducer)) {
234     Options.ReproMode = ReproducerMode::Use;
235     Options.ReproducerPath = ReproducerPath->getValue();
236   }
237 
238   if (Args.hasArg(OPT_gen_reproducer))
239     Options.ReproMode = ReproducerMode::Generate;
240 
241   if (Expected<AccelTableKind> AccelKind = getAccelTableKind(Args)) {
242     Options.LinkOpts.TheAccelTableKind = *AccelKind;
243   } else {
244     return AccelKind.takeError();
245   }
246 
247   if (opt::Arg *SymbolMap = Args.getLastArg(OPT_symbolmap))
248     Options.SymbolMap = SymbolMap->getValue();
249 
250   if (Args.hasArg(OPT_symbolmap))
251     Options.LinkOpts.Update = true;
252 
253   if (Expected<std::vector<std::string>> InputFiles =
254           getInputs(Args, Options.LinkOpts.Update)) {
255     Options.InputFiles = std::move(*InputFiles);
256   } else {
257     return InputFiles.takeError();
258   }
259 
260   for (auto *Arch : Args.filtered(OPT_arch))
261     Options.Archs.push_back(Arch->getValue());
262 
263   if (opt::Arg *OsoPrependPath = Args.getLastArg(OPT_oso_prepend_path))
264     Options.LinkOpts.PrependPath = OsoPrependPath->getValue();
265 
266   for (const auto &Arg : Args.getAllArgValues(OPT_object_prefix_map)) {
267     auto Split = StringRef(Arg).split('=');
268     Options.LinkOpts.ObjectPrefixMap.insert(
269         {std::string(Split.first), std::string(Split.second)});
270   }
271 
272   if (opt::Arg *OutputFile = Args.getLastArg(OPT_output))
273     Options.OutputFile = OutputFile->getValue();
274 
275   if (opt::Arg *Toolchain = Args.getLastArg(OPT_toolchain))
276     Options.Toolchain = Toolchain->getValue();
277 
278   if (Args.hasArg(OPT_assembly))
279     Options.LinkOpts.FileType = OutputFileType::Assembly;
280 
281   if (opt::Arg *NumThreads = Args.getLastArg(OPT_threads))
282     Options.LinkOpts.Threads = atoi(NumThreads->getValue());
283   else
284     Options.LinkOpts.Threads = 0; // Use all available hardware threads
285 
286   if (Options.DumpDebugMap || Options.LinkOpts.Verbose)
287     Options.LinkOpts.Threads = 1;
288 
289   if (getenv("RC_DEBUG_OPTIONS"))
290     Options.PaperTrailWarnings = true;
291 
292   if (opt::Arg *RemarksPrependPath = Args.getLastArg(OPT_remarks_prepend_path))
293     Options.LinkOpts.RemarksPrependPath = RemarksPrependPath->getValue();
294 
295   if (opt::Arg *RemarksOutputFormat =
296           Args.getLastArg(OPT_remarks_output_format)) {
297     if (Expected<remarks::Format> FormatOrErr =
298             remarks::parseFormat(RemarksOutputFormat->getValue()))
299       Options.LinkOpts.RemarksFormat = *FormatOrErr;
300     else
301       return FormatOrErr.takeError();
302   }
303 
304   if (Error E = verifyOptions(Options))
305     return std::move(E);
306   return Options;
307 }
308 
309 static Error createPlistFile(StringRef Bin, StringRef BundleRoot,
310                              StringRef Toolchain) {
311   // Create plist file to write to.
312   SmallString<128> InfoPlist(BundleRoot);
313   sys::path::append(InfoPlist, "Contents/Info.plist");
314   std::error_code EC;
315   raw_fd_ostream PL(InfoPlist, EC, sys::fs::OF_Text);
316   if (EC)
317     return make_error<StringError>(
318         "cannot create Plist: " + toString(errorCodeToError(EC)), EC);
319 
320   CFBundleInfo BI = getBundleInfo(Bin);
321 
322   if (BI.IDStr.empty()) {
323     StringRef BundleID = *sys::path::rbegin(BundleRoot);
324     if (sys::path::extension(BundleRoot) == ".dSYM")
325       BI.IDStr = std::string(sys::path::stem(BundleID));
326     else
327       BI.IDStr = std::string(BundleID);
328   }
329 
330   // Print out information to the plist file.
331   PL << "<?xml version=\"1.0\" encoding=\"UTF-8\"\?>\n"
332      << "<!DOCTYPE plist PUBLIC \"-//Apple Computer//DTD PLIST 1.0//EN\" "
333      << "\"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">\n"
334      << "<plist version=\"1.0\">\n"
335      << "\t<dict>\n"
336      << "\t\t<key>CFBundleDevelopmentRegion</key>\n"
337      << "\t\t<string>English</string>\n"
338      << "\t\t<key>CFBundleIdentifier</key>\n"
339      << "\t\t<string>com.apple.xcode.dsym.";
340   printHTMLEscaped(BI.IDStr, PL);
341   PL << "</string>\n"
342      << "\t\t<key>CFBundleInfoDictionaryVersion</key>\n"
343      << "\t\t<string>6.0</string>\n"
344      << "\t\t<key>CFBundlePackageType</key>\n"
345      << "\t\t<string>dSYM</string>\n"
346      << "\t\t<key>CFBundleSignature</key>\n"
347      << "\t\t<string>\?\?\?\?</string>\n";
348 
349   if (!BI.OmitShortVersion()) {
350     PL << "\t\t<key>CFBundleShortVersionString</key>\n";
351     PL << "\t\t<string>";
352     printHTMLEscaped(BI.ShortVersionStr, PL);
353     PL << "</string>\n";
354   }
355 
356   PL << "\t\t<key>CFBundleVersion</key>\n";
357   PL << "\t\t<string>";
358   printHTMLEscaped(BI.VersionStr, PL);
359   PL << "</string>\n";
360 
361   if (!Toolchain.empty()) {
362     PL << "\t\t<key>Toolchain</key>\n";
363     PL << "\t\t<string>";
364     printHTMLEscaped(Toolchain, PL);
365     PL << "</string>\n";
366   }
367 
368   PL << "\t</dict>\n"
369      << "</plist>\n";
370 
371   PL.close();
372   return Error::success();
373 }
374 
375 static Error createBundleDir(StringRef BundleBase) {
376   SmallString<128> Bundle(BundleBase);
377   sys::path::append(Bundle, "Contents", "Resources", "DWARF");
378   if (std::error_code EC =
379           create_directories(Bundle.str(), true, sys::fs::perms::all_all))
380     return make_error<StringError>(
381         "cannot create bundle: " + toString(errorCodeToError(EC)), EC);
382 
383   return Error::success();
384 }
385 
386 static bool verify(StringRef OutputFile, StringRef Arch, bool Verbose) {
387   if (OutputFile == "-") {
388     WithColor::warning() << "verification skipped for " << Arch
389                          << "because writing to stdout.\n";
390     return true;
391   }
392 
393   Expected<OwningBinary<Binary>> BinOrErr = createBinary(OutputFile);
394   if (!BinOrErr) {
395     WithColor::error() << OutputFile << ": " << toString(BinOrErr.takeError());
396     return false;
397   }
398 
399   Binary &Binary = *BinOrErr.get().getBinary();
400   if (auto *Obj = dyn_cast<MachOObjectFile>(&Binary)) {
401     raw_ostream &os = Verbose ? errs() : nulls();
402     os << "Verifying DWARF for architecture: " << Arch << "\n";
403     std::unique_ptr<DWARFContext> DICtx = DWARFContext::create(*Obj);
404     DIDumpOptions DumpOpts;
405     bool success = DICtx->verify(os, DumpOpts.noImplicitRecursion());
406     if (!success)
407       WithColor::error() << "verification failed for " << Arch << '\n';
408     return success;
409   }
410 
411   return false;
412 }
413 
414 namespace {
415 struct OutputLocation {
416   OutputLocation(std::string DWARFFile, Optional<std::string> ResourceDir = {})
417       : DWARFFile(DWARFFile), ResourceDir(ResourceDir) {}
418   /// This method is a workaround for older compilers.
419   Optional<std::string> getResourceDir() const { return ResourceDir; }
420   std::string DWARFFile;
421   Optional<std::string> ResourceDir;
422 };
423 } // namespace
424 
425 static Expected<OutputLocation>
426 getOutputFileName(StringRef InputFile, const DsymutilOptions &Options) {
427   if (Options.OutputFile == "-")
428     return OutputLocation(Options.OutputFile);
429 
430   // When updating, do in place replacement.
431   if (Options.OutputFile.empty() &&
432       (Options.LinkOpts.Update || !Options.SymbolMap.empty()))
433     return OutputLocation(std::string(InputFile));
434 
435   // If a flat dSYM has been requested, things are pretty simple.
436   if (Options.Flat) {
437     if (Options.OutputFile.empty()) {
438       if (InputFile == "-")
439         return OutputLocation{"a.out.dwarf", {}};
440       return OutputLocation((InputFile + ".dwarf").str());
441     }
442 
443     return OutputLocation(Options.OutputFile);
444   }
445 
446   // We need to create/update a dSYM bundle.
447   // A bundle hierarchy looks like this:
448   //   <bundle name>.dSYM/
449   //       Contents/
450   //          Info.plist
451   //          Resources/
452   //             DWARF/
453   //                <DWARF file(s)>
454   std::string DwarfFile =
455       std::string(InputFile == "-" ? StringRef("a.out") : InputFile);
456   SmallString<128> Path(Options.OutputFile);
457   if (Path.empty())
458     Path = DwarfFile + ".dSYM";
459   if (!Options.LinkOpts.NoOutput) {
460     if (auto E = createBundleDir(Path))
461       return std::move(E);
462     if (auto E = createPlistFile(DwarfFile, Path, Options.Toolchain))
463       return std::move(E);
464   }
465 
466   sys::path::append(Path, "Contents", "Resources");
467   std::string ResourceDir = std::string(Path.str());
468   sys::path::append(Path, "DWARF", sys::path::filename(DwarfFile));
469   return OutputLocation(std::string(Path.str()), ResourceDir);
470 }
471 
472 int main(int argc, char **argv) {
473   InitLLVM X(argc, argv);
474 
475   // Parse arguments.
476   DsymutilOptTable T;
477   unsigned MAI;
478   unsigned MAC;
479   ArrayRef<const char *> ArgsArr = makeArrayRef(argv + 1, argc - 1);
480   opt::InputArgList Args = T.ParseArgs(ArgsArr, MAI, MAC);
481 
482   void *P = (void *)(intptr_t)getOutputFileName;
483   std::string SDKPath = sys::fs::getMainExecutable(argv[0], P);
484   SDKPath = std::string(sys::path::parent_path(SDKPath));
485 
486   for (auto *Arg : Args.filtered(OPT_UNKNOWN)) {
487     WithColor::warning() << "ignoring unknown option: " << Arg->getSpelling()
488                          << '\n';
489   }
490 
491   if (Args.hasArg(OPT_help)) {
492     T.PrintHelp(
493         outs(), (std::string(argv[0]) + " [options] <input files>").c_str(),
494         "manipulate archived DWARF debug symbol files.\n\n"
495         "dsymutil links the DWARF debug information found in the object files\n"
496         "for the executable <input file> by using debug symbols information\n"
497         "contained in its symbol table.\n",
498         false);
499     return 0;
500   }
501 
502   if (Args.hasArg(OPT_version)) {
503     cl::PrintVersionMessage();
504     return 0;
505   }
506 
507   auto OptionsOrErr = getOptions(Args);
508   if (!OptionsOrErr) {
509     WithColor::error() << toString(OptionsOrErr.takeError());
510     return 1;
511   }
512 
513   auto &Options = *OptionsOrErr;
514 
515   InitializeAllTargetInfos();
516   InitializeAllTargetMCs();
517   InitializeAllTargets();
518   InitializeAllAsmPrinters();
519 
520   auto Repro =
521       Reproducer::createReproducer(Options.ReproMode, Options.ReproducerPath);
522   if (!Repro) {
523     WithColor::error() << toString(Repro.takeError());
524     return 1;
525   }
526 
527   Options.LinkOpts.VFS = (*Repro)->getVFS();
528 
529   for (const auto &Arch : Options.Archs)
530     if (Arch != "*" && Arch != "all" &&
531         !object::MachOObjectFile::isValidArch(Arch)) {
532       WithColor::error() << "unsupported cpu architecture: '" << Arch << "'\n";
533       return 1;
534     }
535 
536   SymbolMapLoader SymMapLoader(Options.SymbolMap);
537 
538   for (auto &InputFile : Options.InputFiles) {
539     // Dump the symbol table for each input file and requested arch
540     if (Options.DumpStab) {
541       if (!dumpStab(Options.LinkOpts.VFS, InputFile, Options.Archs,
542                     Options.LinkOpts.PrependPath))
543         return 1;
544       continue;
545     }
546 
547     auto DebugMapPtrsOrErr =
548         parseDebugMap(Options.LinkOpts.VFS, InputFile, Options.Archs,
549                       Options.LinkOpts.PrependPath, Options.PaperTrailWarnings,
550                       Options.LinkOpts.Verbose, Options.InputIsYAMLDebugMap);
551 
552     if (auto EC = DebugMapPtrsOrErr.getError()) {
553       WithColor::error() << "cannot parse the debug map for '" << InputFile
554                          << "': " << EC.message() << '\n';
555       return 1;
556     }
557 
558     // Remember the number of debug maps that are being processed to decide how
559     // to name the remark files.
560     Options.LinkOpts.NumDebugMaps = DebugMapPtrsOrErr->size();
561 
562     if (Options.LinkOpts.Update) {
563       // The debug map should be empty. Add one object file corresponding to
564       // the input file.
565       for (auto &Map : *DebugMapPtrsOrErr)
566         Map->addDebugMapObject(InputFile,
567                                sys::TimePoint<std::chrono::seconds>());
568     }
569 
570     // Ensure that the debug map is not empty (anymore).
571     if (DebugMapPtrsOrErr->empty()) {
572       WithColor::error() << "no architecture to link\n";
573       return 1;
574     }
575 
576     // Shared a single binary holder for all the link steps.
577     BinaryHolder BinHolder(Options.LinkOpts.VFS);
578 
579     // Statistics only require different architectures to be processed
580     // sequentially, the link itself can still happen in parallel. Change the
581     // thread pool strategy here instead of modifying LinkOpts.Threads.
582     ThreadPoolStrategy S = hardware_concurrency(
583         Options.LinkOpts.Statistics ? 1 : Options.LinkOpts.Threads);
584     if (Options.LinkOpts.Threads == 0) {
585       // If NumThreads is not specified, create one thread for each input, up to
586       // the number of hardware threads.
587       S.ThreadsRequested = DebugMapPtrsOrErr->size();
588       S.Limit = true;
589     }
590     ThreadPool Threads(S);
591 
592     // If there is more than one link to execute, we need to generate
593     // temporary files.
594     const bool NeedsTempFiles =
595         !Options.DumpDebugMap && (Options.OutputFile != "-") &&
596         (DebugMapPtrsOrErr->size() != 1 || Options.LinkOpts.Update);
597     const bool Verify = Options.Verify && !Options.LinkOpts.NoOutput;
598 
599     SmallVector<MachOUtils::ArchAndFile, 4> TempFiles;
600     std::atomic_char AllOK(1);
601     for (auto &Map : *DebugMapPtrsOrErr) {
602       if (Options.LinkOpts.Verbose || Options.DumpDebugMap)
603         Map->print(outs());
604 
605       if (Options.DumpDebugMap)
606         continue;
607 
608       if (!Options.SymbolMap.empty())
609         Options.LinkOpts.Translator = SymMapLoader.Load(InputFile, *Map);
610 
611       if (Map->begin() == Map->end())
612         WithColor::warning()
613             << "no debug symbols in executable (-arch "
614             << MachOUtils::getArchName(Map->getTriple().getArchName()) << ")\n";
615 
616       // Using a std::shared_ptr rather than std::unique_ptr because move-only
617       // types don't work with std::bind in the ThreadPool implementation.
618       std::shared_ptr<raw_fd_ostream> OS;
619 
620       Expected<OutputLocation> OutputLocationOrErr =
621           getOutputFileName(InputFile, Options);
622       if (!OutputLocationOrErr) {
623         WithColor::error() << toString(OutputLocationOrErr.takeError());
624         return 1;
625       }
626       Options.LinkOpts.ResourceDir = OutputLocationOrErr->getResourceDir();
627 
628       std::string OutputFile = OutputLocationOrErr->DWARFFile;
629       if (NeedsTempFiles) {
630         TempFiles.emplace_back(Map->getTriple().getArchName().str());
631 
632         auto E = TempFiles.back().createTempFile();
633         if (E) {
634           WithColor::error() << toString(std::move(E));
635           return 1;
636         }
637 
638         auto &TempFile = *(TempFiles.back().File);
639         OS = std::make_shared<raw_fd_ostream>(TempFile.FD,
640                                               /*shouldClose*/ false);
641         OutputFile = TempFile.TmpName;
642       } else {
643         std::error_code EC;
644         OS = std::make_shared<raw_fd_ostream>(
645             Options.LinkOpts.NoOutput ? "-" : OutputFile, EC, sys::fs::OF_None);
646         if (EC) {
647           WithColor::error() << OutputFile << ": " << EC.message();
648           return 1;
649         }
650       }
651 
652       auto LinkLambda = [&, OutputFile](std::shared_ptr<raw_fd_ostream> Stream,
653                                         LinkOptions Options) {
654         AllOK.fetch_and(
655             linkDwarf(*Stream, BinHolder, *Map, std::move(Options)));
656         Stream->flush();
657         if (Verify)
658           AllOK.fetch_and(verify(OutputFile, Map->getTriple().getArchName(),
659                                  Options.Verbose));
660       };
661 
662       // FIXME: The DwarfLinker can have some very deep recursion that can max
663       // out the (significantly smaller) stack when using threads. We don't
664       // want this limitation when we only have a single thread.
665       if (S.ThreadsRequested == 1)
666         LinkLambda(OS, Options.LinkOpts);
667       else
668         Threads.async(LinkLambda, OS, Options.LinkOpts);
669     }
670 
671     Threads.wait();
672 
673     if (!AllOK)
674       return 1;
675 
676     if (NeedsTempFiles) {
677       Expected<OutputLocation> OutputLocationOrErr =
678           getOutputFileName(InputFile, Options);
679       if (!OutputLocationOrErr) {
680         WithColor::error() << toString(OutputLocationOrErr.takeError());
681         return 1;
682       }
683       if (!MachOUtils::generateUniversalBinary(TempFiles,
684                                                OutputLocationOrErr->DWARFFile,
685                                                Options.LinkOpts, SDKPath))
686         return 1;
687     }
688   }
689 
690   return 0;
691 }
692