xref: /llvm-project/llvm/tools/llvm-objcopy/llvm-objcopy.cpp (revision 0f5d5fae93404357c84d7d1b96fddb022c093d49) 
1 //===- llvm-objcopy.cpp ---------------------------------------------------===//
2 //
3 //                      The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm-objcopy.h"
11 #include "Object.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/ADT/Twine.h"
15 #include "llvm/BinaryFormat/ELF.h"
16 #include "llvm/Object/Archive.h"
17 #include "llvm/Object/ArchiveWriter.h"
18 #include "llvm/Object/Binary.h"
19 #include "llvm/Object/ELFObjectFile.h"
20 #include "llvm/Object/ELFTypes.h"
21 #include "llvm/Object/Error.h"
22 #include "llvm/Option/Arg.h"
23 #include "llvm/Option/ArgList.h"
24 #include "llvm/Option/Option.h"
25 #include "llvm/Support/Casting.h"
26 #include "llvm/Support/CommandLine.h"
27 #include "llvm/Support/Compiler.h"
28 #include "llvm/Support/Error.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include "llvm/Support/ErrorOr.h"
31 #include "llvm/Support/FileOutputBuffer.h"
32 #include "llvm/Support/InitLLVM.h"
33 #include "llvm/Support/Path.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include <algorithm>
36 #include <cassert>
37 #include <cstdlib>
38 #include <functional>
39 #include <iterator>
40 #include <memory>
41 #include <string>
42 #include <system_error>
43 #include <utility>
44 
45 using namespace llvm;
46 using namespace llvm::objcopy;
47 using namespace object;
48 using namespace ELF;
49 
50 namespace {
51 
52 enum ObjcopyID {
53   OBJCOPY_INVALID = 0, // This is not an option ID.
54 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
55                HELPTEXT, METAVAR, VALUES)                                      \
56   OBJCOPY_##ID,
57 #include "ObjcopyOpts.inc"
58 #undef OPTION
59 };
60 
61 #define PREFIX(NAME, VALUE) const char *const OBJCOPY_##NAME[] = VALUE;
62 #include "ObjcopyOpts.inc"
63 #undef PREFIX
64 
65 static const opt::OptTable::Info ObjcopyInfoTable[] = {
66 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
67                HELPTEXT, METAVAR, VALUES)                                      \
68   {OBJCOPY_##PREFIX,                                                           \
69    NAME,                                                                       \
70    HELPTEXT,                                                                   \
71    METAVAR,                                                                    \
72    OBJCOPY_##ID,                                                               \
73    opt::Option::KIND##Class,                                                   \
74    PARAM,                                                                      \
75    FLAGS,                                                                      \
76    OBJCOPY_##GROUP,                                                            \
77    OBJCOPY_##ALIAS,                                                            \
78    ALIASARGS,                                                                  \
79    VALUES},
80 #include "ObjcopyOpts.inc"
81 #undef OPTION
82 };
83 
84 class ObjcopyOptTable : public opt::OptTable {
85 public:
86   ObjcopyOptTable() : OptTable(ObjcopyInfoTable, true) {}
87 };
88 
89 enum StripID {
90   STRIP_INVALID = 0, // This is not an option ID.
91 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
92                HELPTEXT, METAVAR, VALUES)                                      \
93   STRIP_##ID,
94 #include "StripOpts.inc"
95 #undef OPTION
96 };
97 
98 #define PREFIX(NAME, VALUE) const char *const STRIP_##NAME[] = VALUE;
99 #include "StripOpts.inc"
100 #undef PREFIX
101 
102 static const opt::OptTable::Info StripInfoTable[] = {
103 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
104                HELPTEXT, METAVAR, VALUES)                                      \
105   {STRIP_##PREFIX, NAME,       HELPTEXT,                                       \
106    METAVAR,        STRIP_##ID, opt::Option::KIND##Class,                       \
107    PARAM,          FLAGS,      STRIP_##GROUP,                                  \
108    STRIP_##ALIAS,  ALIASARGS,  VALUES},
109 #include "StripOpts.inc"
110 #undef OPTION
111 };
112 
113 class StripOptTable : public opt::OptTable {
114 public:
115   StripOptTable() : OptTable(StripInfoTable, true) {}
116 };
117 
118 struct CopyConfig {
119   StringRef OutputFilename;
120   StringRef InputFilename;
121   StringRef OutputFormat;
122   StringRef InputFormat;
123   StringRef BinaryArch;
124 
125   StringRef SplitDWO;
126   StringRef AddGnuDebugLink;
127   std::vector<StringRef> ToRemove;
128   std::vector<StringRef> Keep;
129   std::vector<StringRef> OnlyKeep;
130   std::vector<StringRef> AddSection;
131   std::vector<StringRef> SymbolsToLocalize;
132   std::vector<StringRef> SymbolsToGlobalize;
133   std::vector<StringRef> SymbolsToWeaken;
134   std::vector<StringRef> SymbolsToRemove;
135   std::vector<StringRef> SymbolsToKeep;
136   StringMap<StringRef> SymbolsToRename;
137   bool StripAll = false;
138   bool StripAllGNU = false;
139   bool StripDebug = false;
140   bool StripSections = false;
141   bool StripNonAlloc = false;
142   bool StripDWO = false;
143   bool StripUnneeded = false;
144   bool ExtractDWO = false;
145   bool LocalizeHidden = false;
146   bool Weaken = false;
147   bool DiscardAll = false;
148   bool OnlyKeepDebug = false;
149   bool KeepFileSymbols = false;
150 };
151 
152 using SectionPred = std::function<bool(const SectionBase &Sec)>;
153 
154 } // namespace
155 
156 namespace llvm {
157 namespace objcopy {
158 
159 // The name this program was invoked as.
160 StringRef ToolName;
161 
162 LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
163   errs() << ToolName << ": " << Message << ".\n";
164   errs().flush();
165   exit(1);
166 }
167 
168 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, std::error_code EC) {
169   assert(EC);
170   errs() << ToolName << ": '" << File << "': " << EC.message() << ".\n";
171   exit(1);
172 }
173 
174 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, Error E) {
175   assert(E);
176   std::string Buf;
177   raw_string_ostream OS(Buf);
178   logAllUnhandledErrors(std::move(E), OS, "");
179   OS.flush();
180   errs() << ToolName << ": '" << File << "': " << Buf;
181   exit(1);
182 }
183 
184 } // end namespace objcopy
185 } // end namespace llvm
186 
187 static bool IsDWOSection(const SectionBase &Sec) {
188   return Sec.Name.endswith(".dwo");
189 }
190 
191 static bool OnlyKeepDWOPred(const Object &Obj, const SectionBase &Sec) {
192   // We can't remove the section header string table.
193   if (&Sec == Obj.SectionNames)
194     return false;
195   // Short of keeping the string table we want to keep everything that is a DWO
196   // section and remove everything else.
197   return !IsDWOSection(Sec);
198 }
199 
200 static std::unique_ptr<Writer> CreateWriter(const CopyConfig &Config,
201                                             Object &Obj, Buffer &Buf,
202                                             ElfType OutputElfType) {
203   if (Config.OutputFormat == "binary") {
204     return llvm::make_unique<BinaryWriter>(Obj, Buf);
205   }
206   // Depending on the initial ELFT and OutputFormat we need a different Writer.
207   switch (OutputElfType) {
208   case ELFT_ELF32LE:
209     return llvm::make_unique<ELFWriter<ELF32LE>>(Obj, Buf,
210                                                  !Config.StripSections);
211   case ELFT_ELF64LE:
212     return llvm::make_unique<ELFWriter<ELF64LE>>(Obj, Buf,
213                                                  !Config.StripSections);
214   case ELFT_ELF32BE:
215     return llvm::make_unique<ELFWriter<ELF32BE>>(Obj, Buf,
216                                                  !Config.StripSections);
217   case ELFT_ELF64BE:
218     return llvm::make_unique<ELFWriter<ELF64BE>>(Obj, Buf,
219                                                  !Config.StripSections);
220   }
221   llvm_unreachable("Invalid output format");
222 }
223 
224 static void SplitDWOToFile(const CopyConfig &Config, const Reader &Reader,
225                            StringRef File, ElfType OutputElfType) {
226   auto DWOFile = Reader.create();
227   DWOFile->removeSections(
228       [&](const SectionBase &Sec) { return OnlyKeepDWOPred(*DWOFile, Sec); });
229   FileBuffer FB(File);
230   auto Writer = CreateWriter(Config, *DWOFile, FB, OutputElfType);
231   Writer->finalize();
232   Writer->write();
233 }
234 
235 // This function handles the high level operations of GNU objcopy including
236 // handling command line options. It's important to outline certain properties
237 // we expect to hold of the command line operations. Any operation that "keeps"
238 // should keep regardless of a remove. Additionally any removal should respect
239 // any previous removals. Lastly whether or not something is removed shouldn't
240 // depend a) on the order the options occur in or b) on some opaque priority
241 // system. The only priority is that keeps/copies overrule removes.
242 static void HandleArgs(const CopyConfig &Config, Object &Obj,
243                        const Reader &Reader, ElfType OutputElfType) {
244 
245   if (!Config.SplitDWO.empty()) {
246     SplitDWOToFile(Config, Reader, Config.SplitDWO, OutputElfType);
247   }
248 
249   // TODO: update or remove symbols only if there is an option that affects
250   // them.
251   if (Obj.SymbolTable) {
252     Obj.SymbolTable->updateSymbols([&](Symbol &Sym) {
253       if ((Config.LocalizeHidden &&
254            (Sym.Visibility == STV_HIDDEN || Sym.Visibility == STV_INTERNAL)) ||
255           (!Config.SymbolsToLocalize.empty() &&
256            is_contained(Config.SymbolsToLocalize, Sym.Name)))
257         Sym.Binding = STB_LOCAL;
258 
259       if (!Config.SymbolsToGlobalize.empty() &&
260           is_contained(Config.SymbolsToGlobalize, Sym.Name))
261         Sym.Binding = STB_GLOBAL;
262 
263       if (!Config.SymbolsToWeaken.empty() &&
264           is_contained(Config.SymbolsToWeaken, Sym.Name) &&
265           Sym.Binding == STB_GLOBAL)
266         Sym.Binding = STB_WEAK;
267 
268       if (Config.Weaken && Sym.Binding == STB_GLOBAL &&
269           Sym.getShndx() != SHN_UNDEF)
270         Sym.Binding = STB_WEAK;
271 
272       const auto I = Config.SymbolsToRename.find(Sym.Name);
273       if (I != Config.SymbolsToRename.end())
274         Sym.Name = I->getValue();
275     });
276 
277     // The purpose of this loop is to mark symbols referenced by sections
278     // (like GroupSection or RelocationSection). This way, we know which
279     // symbols are still 'needed' and wich are not.
280     if (Config.StripUnneeded) {
281       for (auto &Section : Obj.sections())
282         Section.markSymbols();
283     }
284 
285     Obj.removeSymbols([&](const Symbol &Sym) {
286       if ((!Config.SymbolsToKeep.empty() &&
287            is_contained(Config.SymbolsToKeep, Sym.Name)) ||
288           (Config.KeepFileSymbols && Sym.Type == STT_FILE))
289         return false;
290 
291       if (Config.DiscardAll && Sym.Binding == STB_LOCAL &&
292           Sym.getShndx() != SHN_UNDEF && Sym.Type != STT_FILE &&
293           Sym.Type != STT_SECTION)
294         return true;
295 
296       if (Config.StripAll || Config.StripAllGNU)
297         return true;
298 
299       if (!Config.SymbolsToRemove.empty() &&
300           is_contained(Config.SymbolsToRemove, Sym.Name)) {
301         return true;
302       }
303 
304       if (Config.StripUnneeded && !Sym.Referenced &&
305           (Sym.Binding == STB_LOCAL || Sym.getShndx() == SHN_UNDEF) &&
306           Sym.Type != STT_FILE && Sym.Type != STT_SECTION)
307         return true;
308 
309       return false;
310     });
311   }
312 
313   SectionPred RemovePred = [](const SectionBase &) { return false; };
314 
315   // Removes:
316   if (!Config.ToRemove.empty()) {
317     RemovePred = [&Config](const SectionBase &Sec) {
318       return std::find(std::begin(Config.ToRemove), std::end(Config.ToRemove),
319                        Sec.Name) != std::end(Config.ToRemove);
320     };
321   }
322 
323   if (Config.StripDWO || !Config.SplitDWO.empty())
324     RemovePred = [RemovePred](const SectionBase &Sec) {
325       return IsDWOSection(Sec) || RemovePred(Sec);
326     };
327 
328   if (Config.ExtractDWO)
329     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
330       return OnlyKeepDWOPred(Obj, Sec) || RemovePred(Sec);
331     };
332 
333   if (Config.StripAllGNU)
334     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
335       if (RemovePred(Sec))
336         return true;
337       if ((Sec.Flags & SHF_ALLOC) != 0)
338         return false;
339       if (&Sec == Obj.SectionNames)
340         return false;
341       switch (Sec.Type) {
342       case SHT_SYMTAB:
343       case SHT_REL:
344       case SHT_RELA:
345       case SHT_STRTAB:
346         return true;
347       }
348       return Sec.Name.startswith(".debug");
349     };
350 
351   if (Config.StripSections) {
352     RemovePred = [RemovePred](const SectionBase &Sec) {
353       return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;
354     };
355   }
356 
357   if (Config.StripDebug) {
358     RemovePred = [RemovePred](const SectionBase &Sec) {
359       return RemovePred(Sec) || Sec.Name.startswith(".debug");
360     };
361   }
362 
363   if (Config.StripNonAlloc)
364     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
365       if (RemovePred(Sec))
366         return true;
367       if (&Sec == Obj.SectionNames)
368         return false;
369       return (Sec.Flags & SHF_ALLOC) == 0;
370     };
371 
372   if (Config.StripAll)
373     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
374       if (RemovePred(Sec))
375         return true;
376       if (&Sec == Obj.SectionNames)
377         return false;
378       if (Sec.Name.startswith(".gnu.warning"))
379         return false;
380       return (Sec.Flags & SHF_ALLOC) == 0;
381     };
382 
383   // Explicit copies:
384   if (!Config.OnlyKeep.empty()) {
385     RemovePred = [&Config, RemovePred, &Obj](const SectionBase &Sec) {
386       // Explicitly keep these sections regardless of previous removes.
387       if (std::find(std::begin(Config.OnlyKeep), std::end(Config.OnlyKeep),
388                     Sec.Name) != std::end(Config.OnlyKeep))
389         return false;
390 
391       // Allow all implicit removes.
392       if (RemovePred(Sec))
393         return true;
394 
395       // Keep special sections.
396       if (Obj.SectionNames == &Sec)
397         return false;
398       if (Obj.SymbolTable == &Sec || Obj.SymbolTable->getStrTab() == &Sec)
399         return false;
400 
401       // Remove everything else.
402       return true;
403     };
404   }
405 
406   if (!Config.Keep.empty()) {
407     RemovePred = [Config, RemovePred](const SectionBase &Sec) {
408       // Explicitly keep these sections regardless of previous removes.
409       if (std::find(std::begin(Config.Keep), std::end(Config.Keep), Sec.Name) !=
410           std::end(Config.Keep))
411         return false;
412       // Otherwise defer to RemovePred.
413       return RemovePred(Sec);
414     };
415   }
416 
417   // This has to be the last predicate assignment.
418   // If the option --keep-symbol has been specified
419   // and at least one of those symbols is present
420   // (equivalently, the updated symbol table is not empty)
421   // the symbol table and the string table should not be removed.
422   if ((!Config.SymbolsToKeep.empty() || Config.KeepFileSymbols) &&
423       !Obj.SymbolTable->empty()) {
424     RemovePred = [&Obj, RemovePred](const SectionBase &Sec) {
425       if (&Sec == Obj.SymbolTable || &Sec == Obj.SymbolTable->getStrTab())
426         return false;
427       return RemovePred(Sec);
428     };
429   }
430 
431   Obj.removeSections(RemovePred);
432 
433   if (!Config.AddSection.empty()) {
434     for (const auto &Flag : Config.AddSection) {
435       auto SecPair = Flag.split("=");
436       auto SecName = SecPair.first;
437       auto File = SecPair.second;
438       auto BufOrErr = MemoryBuffer::getFile(File);
439       if (!BufOrErr)
440         reportError(File, BufOrErr.getError());
441       auto Buf = std::move(*BufOrErr);
442       auto BufPtr = reinterpret_cast<const uint8_t *>(Buf->getBufferStart());
443       auto BufSize = Buf->getBufferSize();
444       Obj.addSection<OwnedDataSection>(SecName,
445                                        ArrayRef<uint8_t>(BufPtr, BufSize));
446     }
447   }
448 
449   if (!Config.AddGnuDebugLink.empty())
450     Obj.addSection<GnuDebugLinkSection>(Config.AddGnuDebugLink);
451 }
452 
453 static void ExecuteElfObjcopyOnBinary(const CopyConfig &Config, Binary &Binary,
454                                       Buffer &Out) {
455   ELFReader Reader(&Binary);
456   std::unique_ptr<Object> Obj = Reader.create();
457 
458   HandleArgs(Config, *Obj, Reader, Reader.getElfType());
459 
460   std::unique_ptr<Writer> Writer =
461       CreateWriter(Config, *Obj, Out, Reader.getElfType());
462   Writer->finalize();
463   Writer->write();
464 }
465 
466 // For regular archives this function simply calls llvm::writeArchive,
467 // For thin archives it writes the archive file itself as well as its members.
468 static Error deepWriteArchive(StringRef ArcName,
469                               ArrayRef<NewArchiveMember> NewMembers,
470                               bool WriteSymtab, object::Archive::Kind Kind,
471                               bool Deterministic, bool Thin) {
472   Error E =
473       writeArchive(ArcName, NewMembers, WriteSymtab, Kind, Deterministic, Thin);
474   if (!Thin || E)
475     return E;
476   for (const NewArchiveMember &Member : NewMembers) {
477     // Internally, FileBuffer will use the buffer created by
478     // FileOutputBuffer::create, for regular files (that is the case for
479     // deepWriteArchive) FileOutputBuffer::create will return OnDiskBuffer.
480     // OnDiskBuffer uses a temporary file and then renames it. So in reality
481     // there is no inefficiency / duplicated in-memory buffers in this case. For
482     // now in-memory buffers can not be completely avoided since
483     // NewArchiveMember still requires them even though writeArchive does not
484     // write them on disk.
485     FileBuffer FB(Member.MemberName);
486     FB.allocate(Member.Buf->getBufferSize());
487     std::copy(Member.Buf->getBufferStart(), Member.Buf->getBufferEnd(),
488               FB.getBufferStart());
489     if (auto E = FB.commit())
490       return E;
491   }
492   return Error::success();
493 }
494 
495 static void ExecuteElfObjcopyOnArchive(const CopyConfig &Config, const Archive &Ar) {
496   std::vector<NewArchiveMember> NewArchiveMembers;
497   Error Err = Error::success();
498   for (const Archive::Child &Child : Ar.children(Err)) {
499     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
500     if (!ChildOrErr)
501       reportError(Ar.getFileName(), ChildOrErr.takeError());
502     Expected<StringRef> ChildNameOrErr = Child.getName();
503     if (!ChildNameOrErr)
504       reportError(Ar.getFileName(), ChildNameOrErr.takeError());
505 
506     MemBuffer MB(ChildNameOrErr.get());
507     ExecuteElfObjcopyOnBinary(Config, **ChildOrErr, MB);
508 
509     Expected<NewArchiveMember> Member =
510         NewArchiveMember::getOldMember(Child, true);
511     if (!Member)
512       reportError(Ar.getFileName(), Member.takeError());
513     Member->Buf = MB.releaseMemoryBuffer();
514     Member->MemberName = Member->Buf->getBufferIdentifier();
515     NewArchiveMembers.push_back(std::move(*Member));
516   }
517 
518   if (Err)
519     reportError(Config.InputFilename, std::move(Err));
520   if (Error E =
521           deepWriteArchive(Config.OutputFilename, NewArchiveMembers,
522                            Ar.hasSymbolTable(), Ar.kind(), true, Ar.isThin()))
523     reportError(Config.OutputFilename, std::move(E));
524 }
525 
526 static void ExecuteElfObjcopy(const CopyConfig &Config) {
527   Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
528       createBinary(Config.InputFilename);
529   if (!BinaryOrErr)
530     reportError(Config.InputFilename, BinaryOrErr.takeError());
531 
532   if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary()))
533     return ExecuteElfObjcopyOnArchive(Config, *Ar);
534 
535   FileBuffer FB(Config.OutputFilename);
536   ExecuteElfObjcopyOnBinary(Config, *BinaryOrErr.get().getBinary(), FB);
537 }
538 
539 // ParseObjcopyOptions returns the config and sets the input arguments. If a
540 // help flag is set then ParseObjcopyOptions will print the help messege and
541 // exit.
542 static CopyConfig ParseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
543   ObjcopyOptTable T;
544   unsigned MissingArgumentIndex, MissingArgumentCount;
545   llvm::opt::InputArgList InputArgs =
546       T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
547 
548   if (InputArgs.size() == 0) {
549     T.PrintHelp(errs(), "llvm-objcopy <input> [ <output> ]", "objcopy tool");
550     exit(1);
551   }
552 
553   if (InputArgs.hasArg(OBJCOPY_help)) {
554     T.PrintHelp(outs(), "llvm-objcopy <input> [ <output> ]", "objcopy tool");
555     exit(0);
556   }
557 
558   SmallVector<const char *, 2> Positional;
559 
560   for (auto Arg : InputArgs.filtered(OBJCOPY_UNKNOWN))
561     error("unknown argument '" + Arg->getAsString(InputArgs) + "'");
562 
563   for (auto Arg : InputArgs.filtered(OBJCOPY_INPUT))
564     Positional.push_back(Arg->getValue());
565 
566   if (Positional.empty())
567     error("No input file specified");
568 
569   if (Positional.size() > 2)
570     error("Too many positional arguments");
571 
572   CopyConfig Config;
573   Config.InputFilename = Positional[0];
574   Config.OutputFilename = Positional[Positional.size() == 1 ? 0 : 1];
575   Config.InputFormat = InputArgs.getLastArgValue(OBJCOPY_input_target);
576   Config.OutputFormat = InputArgs.getLastArgValue(OBJCOPY_output_target);
577   Config.BinaryArch = InputArgs.getLastArgValue(OBJCOPY_binary_architecture);
578 
579   Config.SplitDWO = InputArgs.getLastArgValue(OBJCOPY_split_dwo);
580   Config.AddGnuDebugLink = InputArgs.getLastArgValue(OBJCOPY_add_gnu_debuglink);
581 
582   for (auto Arg : InputArgs.filtered(OBJCOPY_redefine_symbol)) {
583     if (!StringRef(Arg->getValue()).contains('='))
584       error("Bad format for --redefine-sym");
585     auto Old2New = StringRef(Arg->getValue()).split('=');
586     if (!Config.SymbolsToRename.insert(Old2New).second)
587       error("Multiple redefinition of symbol " + Old2New.first);
588   }
589 
590   for (auto Arg : InputArgs.filtered(OBJCOPY_remove_section))
591     Config.ToRemove.push_back(Arg->getValue());
592   for (auto Arg : InputArgs.filtered(OBJCOPY_keep))
593     Config.Keep.push_back(Arg->getValue());
594   for (auto Arg : InputArgs.filtered(OBJCOPY_only_keep))
595     Config.OnlyKeep.push_back(Arg->getValue());
596   for (auto Arg : InputArgs.filtered(OBJCOPY_add_section))
597     Config.AddSection.push_back(Arg->getValue());
598   Config.StripAll = InputArgs.hasArg(OBJCOPY_strip_all);
599   Config.StripAllGNU = InputArgs.hasArg(OBJCOPY_strip_all_gnu);
600   Config.StripDebug = InputArgs.hasArg(OBJCOPY_strip_debug);
601   Config.StripDWO = InputArgs.hasArg(OBJCOPY_strip_dwo);
602   Config.StripSections = InputArgs.hasArg(OBJCOPY_strip_sections);
603   Config.StripNonAlloc = InputArgs.hasArg(OBJCOPY_strip_non_alloc);
604   Config.StripUnneeded = InputArgs.hasArg(OBJCOPY_strip_unneeded);
605   Config.ExtractDWO = InputArgs.hasArg(OBJCOPY_extract_dwo);
606   Config.LocalizeHidden = InputArgs.hasArg(OBJCOPY_localize_hidden);
607   Config.Weaken = InputArgs.hasArg(OBJCOPY_weaken);
608   Config.DiscardAll = InputArgs.hasArg(OBJCOPY_discard_all);
609   Config.OnlyKeepDebug = InputArgs.hasArg(OBJCOPY_only_keep_debug);
610   Config.KeepFileSymbols = InputArgs.hasArg(OBJCOPY_keep_file_symbols);
611   for (auto Arg : InputArgs.filtered(OBJCOPY_localize_symbol))
612     Config.SymbolsToLocalize.push_back(Arg->getValue());
613   for (auto Arg : InputArgs.filtered(OBJCOPY_globalize_symbol))
614     Config.SymbolsToGlobalize.push_back(Arg->getValue());
615   for (auto Arg : InputArgs.filtered(OBJCOPY_weaken_symbol))
616     Config.SymbolsToWeaken.push_back(Arg->getValue());
617   for (auto Arg : InputArgs.filtered(OBJCOPY_strip_symbol))
618     Config.SymbolsToRemove.push_back(Arg->getValue());
619   for (auto Arg : InputArgs.filtered(OBJCOPY_keep_symbol))
620     Config.SymbolsToKeep.push_back(Arg->getValue());
621 
622   return Config;
623 }
624 
625 // ParseStripOptions returns the config and sets the input arguments. If a
626 // help flag is set then ParseStripOptions will print the help messege and
627 // exit.
628 static CopyConfig ParseStripOptions(ArrayRef<const char *> ArgsArr) {
629   StripOptTable T;
630   unsigned MissingArgumentIndex, MissingArgumentCount;
631   llvm::opt::InputArgList InputArgs =
632       T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
633 
634   if (InputArgs.size() == 0) {
635     T.PrintHelp(errs(), "llvm-strip <input> [ <output> ]", "strip tool");
636     exit(1);
637   }
638 
639   if (InputArgs.hasArg(STRIP_help)) {
640     T.PrintHelp(outs(), "llvm-strip <input> [ <output> ]", "strip tool");
641     exit(0);
642   }
643 
644   SmallVector<const char *, 2> Positional;
645   for (auto Arg : InputArgs.filtered(STRIP_UNKNOWN))
646     error("unknown argument '" + Arg->getAsString(InputArgs) + "'");
647   for (auto Arg : InputArgs.filtered(STRIP_INPUT))
648     Positional.push_back(Arg->getValue());
649 
650   if (Positional.empty())
651     error("No input file specified");
652 
653   if (Positional.size() > 2)
654     error("Support for multiple input files is not implemented yet");
655 
656   CopyConfig Config;
657   Config.InputFilename = Positional[0];
658   Config.OutputFilename =
659       InputArgs.getLastArgValue(STRIP_output, Positional[0]);
660 
661   Config.StripDebug = InputArgs.hasArg(STRIP_strip_debug);
662 
663   Config.DiscardAll = InputArgs.hasArg(STRIP_discard_all);
664   Config.StripUnneeded = InputArgs.hasArg(STRIP_strip_unneeded);
665   Config.StripAll = InputArgs.hasArg(STRIP_strip_all);
666 
667   if (!Config.StripDebug && !Config.StripUnneeded && !Config.DiscardAll)
668     Config.StripAll = true;
669 
670   for (auto Arg : InputArgs.filtered(STRIP_remove_section))
671     Config.ToRemove.push_back(Arg->getValue());
672 
673   for (auto Arg : InputArgs.filtered(STRIP_keep_symbol))
674     Config.SymbolsToKeep.push_back(Arg->getValue());
675 
676   return Config;
677 }
678 
679 int main(int argc, char **argv) {
680   InitLLVM X(argc, argv);
681   ToolName = argv[0];
682   CopyConfig Config;
683   if (sys::path::stem(ToolName).endswith_lower("strip"))
684     Config = ParseStripOptions(makeArrayRef(argv + 1, argc));
685   else
686     Config = ParseObjcopyOptions(makeArrayRef(argv + 1, argc));
687   ExecuteElfObjcopy(Config);
688 }
689