1 //===- DriverUtils.cpp ----------------------------------------------------===//
2 //
3 //                             The LLVM Linker
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains utility functions for the driver. Because there
11 // are so many small functions, we created this separate file to make
12 // Driver.cpp less cluttered.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "Config.h"
17 #include "Driver.h"
18 #include "Error.h"
19 #include "Symbols.h"
20 #include "llvm/ADT/Optional.h"
21 #include "llvm/ADT/StringSwitch.h"
22 #include "llvm/Object/COFF.h"
23 #include "llvm/Option/Arg.h"
24 #include "llvm/Option/ArgList.h"
25 #include "llvm/Option/Option.h"
26 #include "llvm/Support/CommandLine.h"
27 #include "llvm/Support/FileUtilities.h"
28 #include "llvm/Support/Process.h"
29 #include "llvm/Support/Program.h"
30 #include "llvm/Support/raw_ostream.h"
31 #include <memory>
32 
33 using namespace llvm::COFF;
34 using namespace llvm;
35 using llvm::cl::ExpandResponseFiles;
36 using llvm::cl::TokenizeWindowsCommandLine;
37 using llvm::sys::Process;
38 
39 namespace lld {
40 namespace coff {
41 namespace {
42 
43 class Executor {
44 public:
45   explicit Executor(StringRef S) : Saver(Alloc), Prog(Saver.save(S)) {}
46   void add(StringRef S)    { Args.push_back(Saver.save(S)); }
47   void add(std::string &S) { Args.push_back(Saver.save(S)); }
48   void add(Twine S)        { Args.push_back(Saver.save(S)); }
49   void add(const char *S)  { Args.push_back(Saver.save(S)); }
50 
51   void run() {
52     ErrorOr<std::string> ExeOrErr = llvm::sys::findProgramByName(Prog);
53     if (auto EC = ExeOrErr.getError())
54       fatal(EC, "unable to find " + Prog + " in PATH: ");
55     const char *Exe = Saver.save(*ExeOrErr);
56     Args.insert(Args.begin(), Exe);
57     Args.push_back(nullptr);
58     if (llvm::sys::ExecuteAndWait(Args[0], Args.data()) != 0) {
59       for (const char *S : Args)
60         if (S)
61           llvm::errs() << S << " ";
62       fatal("ExecuteAndWait failed");
63     }
64   }
65 
66 private:
67   llvm::BumpPtrAllocator Alloc;
68   llvm::StringSaver Saver;
69   StringRef Prog;
70   std::vector<const char *> Args;
71 };
72 
73 } // anonymous namespace
74 
75 // Returns /machine's value.
76 MachineTypes getMachineType(StringRef S) {
77   MachineTypes MT = StringSwitch<MachineTypes>(S.lower())
78                         .Case("x64", AMD64)
79                         .Case("amd64", AMD64)
80                         .Case("x86", I386)
81                         .Case("i386", I386)
82                         .Case("arm", ARMNT)
83                         .Default(IMAGE_FILE_MACHINE_UNKNOWN);
84   if (MT != IMAGE_FILE_MACHINE_UNKNOWN)
85     return MT;
86   fatal("unknown /machine argument: " + S);
87 }
88 
89 StringRef machineToStr(MachineTypes MT) {
90   switch (MT) {
91   case ARMNT:
92     return "arm";
93   case AMD64:
94     return "x64";
95   case I386:
96     return "x86";
97   default:
98     llvm_unreachable("unknown machine type");
99   }
100 }
101 
102 // Parses a string in the form of "<integer>[,<integer>]".
103 void parseNumbers(StringRef Arg, uint64_t *Addr, uint64_t *Size) {
104   StringRef S1, S2;
105   std::tie(S1, S2) = Arg.split(',');
106   if (S1.getAsInteger(0, *Addr))
107     fatal("invalid number: " + S1);
108   if (Size && !S2.empty() && S2.getAsInteger(0, *Size))
109     fatal("invalid number: " + S2);
110 }
111 
112 // Parses a string in the form of "<integer>[.<integer>]".
113 // If second number is not present, Minor is set to 0.
114 void parseVersion(StringRef Arg, uint32_t *Major, uint32_t *Minor) {
115   StringRef S1, S2;
116   std::tie(S1, S2) = Arg.split('.');
117   if (S1.getAsInteger(0, *Major))
118     fatal("invalid number: " + S1);
119   *Minor = 0;
120   if (!S2.empty() && S2.getAsInteger(0, *Minor))
121     fatal("invalid number: " + S2);
122 }
123 
124 // Parses a string in the form of "<subsystem>[,<integer>[.<integer>]]".
125 void parseSubsystem(StringRef Arg, WindowsSubsystem *Sys, uint32_t *Major,
126                     uint32_t *Minor) {
127   StringRef SysStr, Ver;
128   std::tie(SysStr, Ver) = Arg.split(',');
129   *Sys = StringSwitch<WindowsSubsystem>(SysStr.lower())
130     .Case("boot_application", IMAGE_SUBSYSTEM_WINDOWS_BOOT_APPLICATION)
131     .Case("console", IMAGE_SUBSYSTEM_WINDOWS_CUI)
132     .Case("efi_application", IMAGE_SUBSYSTEM_EFI_APPLICATION)
133     .Case("efi_boot_service_driver", IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
134     .Case("efi_rom", IMAGE_SUBSYSTEM_EFI_ROM)
135     .Case("efi_runtime_driver", IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
136     .Case("native", IMAGE_SUBSYSTEM_NATIVE)
137     .Case("posix", IMAGE_SUBSYSTEM_POSIX_CUI)
138     .Case("windows", IMAGE_SUBSYSTEM_WINDOWS_GUI)
139     .Default(IMAGE_SUBSYSTEM_UNKNOWN);
140   if (*Sys == IMAGE_SUBSYSTEM_UNKNOWN)
141     fatal("unknown subsystem: " + SysStr);
142   if (!Ver.empty())
143     parseVersion(Ver, Major, Minor);
144 }
145 
146 // Parse a string of the form of "<from>=<to>".
147 // Results are directly written to Config.
148 void parseAlternateName(StringRef S) {
149   StringRef From, To;
150   std::tie(From, To) = S.split('=');
151   if (From.empty() || To.empty())
152     fatal("/alternatename: invalid argument: " + S);
153   auto It = Config->AlternateNames.find(From);
154   if (It != Config->AlternateNames.end() && It->second != To)
155     fatal("/alternatename: conflicts: " + S);
156   Config->AlternateNames.insert(It, std::make_pair(From, To));
157 }
158 
159 // Parse a string of the form of "<from>=<to>".
160 // Results are directly written to Config.
161 void parseMerge(StringRef S) {
162   StringRef From, To;
163   std::tie(From, To) = S.split('=');
164   if (From.empty() || To.empty())
165     fatal("/merge: invalid argument: " + S);
166   auto Pair = Config->Merge.insert(std::make_pair(From, To));
167   bool Inserted = Pair.second;
168   if (!Inserted) {
169     StringRef Existing = Pair.first->second;
170     if (Existing != To)
171       llvm::errs() << "warning: " << S << ": already merged into "
172                    << Existing << "\n";
173   }
174 }
175 
176 static uint32_t parseSectionAttributes(StringRef S) {
177   uint32_t Ret = 0;
178   for (char C : S.lower()) {
179     switch (C) {
180     case 'd':
181       Ret |= IMAGE_SCN_MEM_DISCARDABLE;
182       break;
183     case 'e':
184       Ret |= IMAGE_SCN_MEM_EXECUTE;
185       break;
186     case 'k':
187       Ret |= IMAGE_SCN_MEM_NOT_CACHED;
188       break;
189     case 'p':
190       Ret |= IMAGE_SCN_MEM_NOT_PAGED;
191       break;
192     case 'r':
193       Ret |= IMAGE_SCN_MEM_READ;
194       break;
195     case 's':
196       Ret |= IMAGE_SCN_MEM_SHARED;
197       break;
198     case 'w':
199       Ret |= IMAGE_SCN_MEM_WRITE;
200       break;
201     default:
202       fatal("/section: invalid argument: " + S);
203     }
204   }
205   return Ret;
206 }
207 
208 // Parses /section option argument.
209 void parseSection(StringRef S) {
210   StringRef Name, Attrs;
211   std::tie(Name, Attrs) = S.split(',');
212   if (Name.empty() || Attrs.empty())
213     fatal("/section: invalid argument: " + S);
214   Config->Section[Name] = parseSectionAttributes(Attrs);
215 }
216 
217 // Parses a string in the form of "EMBED[,=<integer>]|NO".
218 // Results are directly written to Config.
219 void parseManifest(StringRef Arg) {
220   if (Arg.equals_lower("no")) {
221     Config->Manifest = Configuration::No;
222     return;
223   }
224   if (!Arg.startswith_lower("embed"))
225     fatal("invalid option " + Arg);
226   Config->Manifest = Configuration::Embed;
227   Arg = Arg.substr(strlen("embed"));
228   if (Arg.empty())
229     return;
230   if (!Arg.startswith_lower(",id="))
231     fatal("invalid option " + Arg);
232   Arg = Arg.substr(strlen(",id="));
233   if (Arg.getAsInteger(0, Config->ManifestID))
234     fatal("invalid option " + Arg);
235 }
236 
237 // Parses a string in the form of "level=<string>|uiAccess=<string>|NO".
238 // Results are directly written to Config.
239 void parseManifestUAC(StringRef Arg) {
240   if (Arg.equals_lower("no")) {
241     Config->ManifestUAC = false;
242     return;
243   }
244   for (;;) {
245     Arg = Arg.ltrim();
246     if (Arg.empty())
247       return;
248     if (Arg.startswith_lower("level=")) {
249       Arg = Arg.substr(strlen("level="));
250       std::tie(Config->ManifestLevel, Arg) = Arg.split(" ");
251       continue;
252     }
253     if (Arg.startswith_lower("uiaccess=")) {
254       Arg = Arg.substr(strlen("uiaccess="));
255       std::tie(Config->ManifestUIAccess, Arg) = Arg.split(" ");
256       continue;
257     }
258     fatal("invalid option " + Arg);
259   }
260 }
261 
262 // Quote each line with "". Existing double-quote is converted
263 // to two double-quotes.
264 static void quoteAndPrint(raw_ostream &Out, StringRef S) {
265   while (!S.empty()) {
266     StringRef Line;
267     std::tie(Line, S) = S.split("\n");
268     if (Line.empty())
269       continue;
270     Out << '\"';
271     for (int I = 0, E = Line.size(); I != E; ++I) {
272       if (Line[I] == '\"') {
273         Out << "\"\"";
274       } else {
275         Out << Line[I];
276       }
277     }
278     Out << "\"\n";
279   }
280 }
281 
282 // Create the default manifest file as a temporary file.
283 static std::string createDefaultXml() {
284   // Create a temporary file.
285   SmallString<128> Path;
286   if (auto EC = sys::fs::createTemporaryFile("tmp", "manifest", Path))
287     fatal(EC, "cannot create a temporary file");
288 
289   // Open the temporary file for writing.
290   std::error_code EC;
291   llvm::raw_fd_ostream OS(Path, EC, sys::fs::F_Text);
292   if (EC)
293     fatal(EC, "failed to open " + Path);
294 
295   // Emit the XML. Note that we do *not* verify that the XML attributes are
296   // syntactically correct. This is intentional for link.exe compatibility.
297   OS << "<?xml version=\"1.0\" standalone=\"yes\"?>\n"
298      << "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\"\n"
299      << "          manifestVersion=\"1.0\">\n";
300   if (Config->ManifestUAC) {
301     OS << "  <trustInfo>\n"
302        << "    <security>\n"
303        << "      <requestedPrivileges>\n"
304        << "         <requestedExecutionLevel level=" << Config->ManifestLevel
305        << " uiAccess=" << Config->ManifestUIAccess << "/>\n"
306        << "      </requestedPrivileges>\n"
307        << "    </security>\n"
308        << "  </trustInfo>\n";
309     if (!Config->ManifestDependency.empty()) {
310       OS << "  <dependency>\n"
311          << "    <dependentAssembly>\n"
312          << "      <assemblyIdentity " << Config->ManifestDependency << " />\n"
313          << "    </dependentAssembly>\n"
314          << "  </dependency>\n";
315     }
316   }
317   OS << "</assembly>\n";
318   OS.close();
319   return StringRef(Path);
320 }
321 
322 static std::string readFile(StringRef Path) {
323   std::unique_ptr<MemoryBuffer> MB =
324       check(MemoryBuffer::getFile(Path), "could not open " + Path);
325   std::unique_ptr<MemoryBuffer> Buf(std::move(MB));
326   return Buf->getBuffer();
327 }
328 
329 static std::string createManifestXml() {
330   // Create the default manifest file.
331   std::string Path1 = createDefaultXml();
332   if (Config->ManifestInput.empty())
333     return readFile(Path1);
334 
335   // If manifest files are supplied by the user using /MANIFESTINPUT
336   // option, we need to merge them with the default manifest.
337   SmallString<128> Path2;
338   if (auto EC = sys::fs::createTemporaryFile("tmp", "manifest", Path2))
339     fatal(EC, "cannot create a temporary file");
340   FileRemover Remover1(Path1);
341   FileRemover Remover2(Path2);
342 
343   Executor E("mt.exe");
344   E.add("/manifest");
345   E.add(Path1);
346   for (StringRef Filename : Config->ManifestInput) {
347     E.add("/manifest");
348     E.add(Filename);
349   }
350   E.add("/nologo");
351   E.add("/out:" + StringRef(Path2));
352   E.run();
353   return readFile(Path2);
354 }
355 
356 // Create a resource file containing a manifest XML.
357 std::unique_ptr<MemoryBuffer> createManifestRes() {
358   // Create a temporary file for the resource script file.
359   SmallString<128> RCPath;
360   if (auto EC = sys::fs::createTemporaryFile("tmp", "rc", RCPath))
361     fatal(EC, "cannot create a temporary file");
362   FileRemover RCRemover(RCPath);
363 
364   // Open the temporary file for writing.
365   std::error_code EC;
366   llvm::raw_fd_ostream Out(RCPath, EC, sys::fs::F_Text);
367   if (EC)
368     fatal(EC, "failed to open " + RCPath);
369 
370   // Write resource script to the RC file.
371   Out << "#define LANG_ENGLISH 9\n"
372       << "#define SUBLANG_DEFAULT 1\n"
373       << "#define APP_MANIFEST " << Config->ManifestID << "\n"
374       << "#define RT_MANIFEST 24\n"
375       << "LANGUAGE LANG_ENGLISH, SUBLANG_DEFAULT\n"
376       << "APP_MANIFEST RT_MANIFEST {\n";
377   quoteAndPrint(Out, createManifestXml());
378   Out << "}\n";
379   Out.close();
380 
381   // Create output resource file.
382   SmallString<128> ResPath;
383   if (auto EC = sys::fs::createTemporaryFile("tmp", "res", ResPath))
384     fatal(EC, "cannot create a temporary file");
385 
386   Executor E("rc.exe");
387   E.add("/fo");
388   E.add(ResPath.str());
389   E.add("/nologo");
390   E.add(RCPath.str());
391   E.run();
392   return check(MemoryBuffer::getFile(ResPath), "could not open " + ResPath);
393 }
394 
395 void createSideBySideManifest() {
396   std::string Path = Config->ManifestFile;
397   if (Path == "")
398     Path = Config->OutputFile + ".manifest";
399   std::error_code EC;
400   llvm::raw_fd_ostream Out(Path, EC, llvm::sys::fs::F_Text);
401   if (EC)
402     fatal(EC, "failed to create manifest");
403   Out << createManifestXml();
404 }
405 
406 // Parse a string in the form of
407 // "<name>[=<internalname>][,@ordinal[,NONAME]][,DATA][,PRIVATE]"
408 // or "<name>=<dllname>.<name>".
409 // Used for parsing /export arguments.
410 Export parseExport(StringRef Arg) {
411   Export E;
412   StringRef Rest;
413   std::tie(E.Name, Rest) = Arg.split(",");
414   if (E.Name.empty())
415     goto err;
416 
417   if (E.Name.find('=') != StringRef::npos) {
418     StringRef X, Y;
419     std::tie(X, Y) = E.Name.split("=");
420 
421     // If "<name>=<dllname>.<name>".
422     if (Y.find(".") != StringRef::npos) {
423       E.Name = X;
424       E.ForwardTo = Y;
425       return E;
426     }
427 
428     E.ExtName = X;
429     E.Name = Y;
430     if (E.Name.empty())
431       goto err;
432   }
433 
434   // If "<name>=<internalname>[,@ordinal[,NONAME]][,DATA][,PRIVATE]"
435   while (!Rest.empty()) {
436     StringRef Tok;
437     std::tie(Tok, Rest) = Rest.split(",");
438     if (Tok.equals_lower("noname")) {
439       if (E.Ordinal == 0)
440         goto err;
441       E.Noname = true;
442       continue;
443     }
444     if (Tok.equals_lower("data")) {
445       E.Data = true;
446       continue;
447     }
448     if (Tok.equals_lower("private")) {
449       E.Private = true;
450       continue;
451     }
452     if (Tok.startswith("@")) {
453       int32_t Ord;
454       if (Tok.substr(1).getAsInteger(0, Ord))
455         goto err;
456       if (Ord <= 0 || 65535 < Ord)
457         goto err;
458       E.Ordinal = Ord;
459       continue;
460     }
461     goto err;
462   }
463   return E;
464 
465 err:
466   fatal("invalid /export: " + Arg);
467 }
468 
469 static StringRef undecorate(StringRef Sym) {
470   if (Config->Machine != I386)
471     return Sym;
472   return Sym.startswith("_") ? Sym.substr(1) : Sym;
473 }
474 
475 // Performs error checking on all /export arguments.
476 // It also sets ordinals.
477 void fixupExports() {
478   // Symbol ordinals must be unique.
479   std::set<uint16_t> Ords;
480   for (Export &E : Config->Exports) {
481     if (E.Ordinal == 0)
482       continue;
483     if (!Ords.insert(E.Ordinal).second)
484       fatal("duplicate export ordinal: " + E.Name);
485   }
486 
487   for (Export &E : Config->Exports) {
488     if (!E.ForwardTo.empty()) {
489       E.SymbolName = E.Name;
490     } else if (Undefined *U = cast_or_null<Undefined>(E.Sym->WeakAlias)) {
491       E.SymbolName = U->getName();
492     } else {
493       E.SymbolName = E.Sym->getName();
494     }
495   }
496 
497   for (Export &E : Config->Exports) {
498     if (!E.ForwardTo.empty()) {
499       E.ExportName = undecorate(E.Name);
500     } else {
501       E.ExportName = undecorate(E.ExtName.empty() ? E.Name : E.ExtName);
502     }
503   }
504 
505   // Uniquefy by name.
506   std::map<StringRef, Export *> Map;
507   std::vector<Export> V;
508   for (Export &E : Config->Exports) {
509     auto Pair = Map.insert(std::make_pair(E.ExportName, &E));
510     bool Inserted = Pair.second;
511     if (Inserted) {
512       V.push_back(E);
513       continue;
514     }
515     Export *Existing = Pair.first->second;
516     if (E == *Existing || E.Name != Existing->Name)
517       continue;
518     llvm::errs() << "warning: duplicate /export option: " << E.Name << "\n";
519   }
520   Config->Exports = std::move(V);
521 
522   // Sort by name.
523   std::sort(Config->Exports.begin(), Config->Exports.end(),
524             [](const Export &A, const Export &B) {
525               return A.ExportName < B.ExportName;
526             });
527 }
528 
529 void assignExportOrdinals() {
530   // Assign unique ordinals if default (= 0).
531   uint16_t Max = 0;
532   for (Export &E : Config->Exports)
533     Max = std::max(Max, E.Ordinal);
534   for (Export &E : Config->Exports)
535     if (E.Ordinal == 0)
536       E.Ordinal = ++Max;
537 }
538 
539 // Parses a string in the form of "key=value" and check
540 // if value matches previous values for the same key.
541 void checkFailIfMismatch(StringRef Arg) {
542   StringRef K, V;
543   std::tie(K, V) = Arg.split('=');
544   if (K.empty() || V.empty())
545     fatal("/failifmismatch: invalid argument: " + Arg);
546   StringRef Existing = Config->MustMatch[K];
547   if (!Existing.empty() && V != Existing)
548     fatal("/failifmismatch: mismatch detected: " + Existing + " and " + V +
549           " for key " + K);
550   Config->MustMatch[K] = V;
551 }
552 
553 // Convert Windows resource files (.res files) to a .obj file
554 // using cvtres.exe.
555 std::unique_ptr<MemoryBuffer>
556 convertResToCOFF(const std::vector<MemoryBufferRef> &MBs) {
557   // Create an output file path.
558   SmallString<128> Path;
559   if (auto EC = llvm::sys::fs::createTemporaryFile("resource", "obj", Path))
560     fatal(EC, "could not create temporary file");
561 
562   // Execute cvtres.exe.
563   Executor E("cvtres.exe");
564   E.add("/machine:" + machineToStr(Config->Machine));
565   E.add("/readonly");
566   E.add("/nologo");
567   E.add("/out:" + Path);
568   for (MemoryBufferRef MB : MBs)
569     E.add(MB.getBufferIdentifier());
570   E.run();
571   return check(MemoryBuffer::getFile(Path), "could not open " + Path);
572 }
573 
574 // Create OptTable
575 
576 // Create prefix string literals used in Options.td
577 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
578 #include "Options.inc"
579 #undef PREFIX
580 
581 // Create table mapping all options defined in Options.td
582 static const llvm::opt::OptTable::Info infoTable[] = {
583 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X6, X7, X8, X9, X10)    \
584   {                                                                    \
585     X1, X2, X9, X10, OPT_##ID, llvm::opt::Option::KIND##Class, X8, X7, \
586     OPT_##GROUP, OPT_##ALIAS, X6                                       \
587   },
588 #include "Options.inc"
589 #undef OPTION
590 };
591 
592 class COFFOptTable : public llvm::opt::OptTable {
593 public:
594   COFFOptTable() : OptTable(infoTable, true) {}
595 };
596 
597 // Parses a given list of options.
598 llvm::opt::InputArgList ArgParser::parse(ArrayRef<const char *> ArgsArr) {
599   // First, replace respnose files (@<file>-style options).
600   std::vector<const char *> Argv = replaceResponseFiles(ArgsArr);
601 
602   // Make InputArgList from string vectors.
603   COFFOptTable Table;
604   unsigned MissingIndex;
605   unsigned MissingCount;
606   llvm::opt::InputArgList Args =
607       Table.ParseArgs(Argv, MissingIndex, MissingCount);
608 
609   // Print the real command line if response files are expanded.
610   if (Args.hasArg(OPT_verbose) && ArgsArr.size() != Argv.size()) {
611     llvm::outs() << "Command line:";
612     for (const char *S : Argv)
613       llvm::outs() << " " << S;
614     llvm::outs() << "\n";
615   }
616 
617   if (MissingCount)
618     fatal("missing arg value for \"" + Twine(Args.getArgString(MissingIndex)) +
619           "\", expected " + Twine(MissingCount) +
620           (MissingCount == 1 ? " argument." : " arguments."));
621   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
622     llvm::errs() << "ignoring unknown argument: " << Arg->getSpelling() << "\n";
623   return Args;
624 }
625 
626 llvm::opt::InputArgList ArgParser::parseLINK(ArrayRef<const char *> Args) {
627   // Concatenate LINK env and given arguments and parse them.
628   Optional<std::string> Env = Process::GetEnv("LINK");
629   if (!Env)
630     return parse(Args);
631   std::vector<const char *> V = tokenize(*Env);
632   V.insert(V.end(), Args.begin(), Args.end());
633   return parse(V);
634 }
635 
636 std::vector<const char *> ArgParser::tokenize(StringRef S) {
637   SmallVector<const char *, 16> Tokens;
638   StringSaver Saver(AllocAux);
639   llvm::cl::TokenizeWindowsCommandLine(S, Saver, Tokens);
640   return std::vector<const char *>(Tokens.begin(), Tokens.end());
641 }
642 
643 // Creates a new command line by replacing options starting with '@'
644 // character. '@<filename>' is replaced by the file's contents.
645 std::vector<const char *>
646 ArgParser::replaceResponseFiles(std::vector<const char *> Argv) {
647   SmallVector<const char *, 256> Tokens(Argv.data(), Argv.data() + Argv.size());
648   StringSaver Saver(AllocAux);
649   ExpandResponseFiles(Saver, TokenizeWindowsCommandLine, Tokens);
650   return std::vector<const char *>(Tokens.begin(), Tokens.end());
651 }
652 
653 void printHelp(const char *Argv0) {
654   COFFOptTable Table;
655   Table.PrintHelp(llvm::outs(), Argv0, "LLVM Linker", false);
656 }
657 
658 } // namespace coff
659 } // namespace lld
660