xref: /llvm-project/llvm/tools/llvm-objcopy/llvm-objcopy.cpp (revision e8c3c5fe5d04e890b3ebbf12eefc8d8f14e96438) 
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 object;
47 using namespace ELF;
48 
49 namespace {
50 
51 enum ObjcopyID {
52   OBJCOPY_INVALID = 0, // This is not an option ID.
53 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
54                HELPTEXT, METAVAR, VALUES)                                      \
55   OBJCOPY_##ID,
56 #include "ObjcopyOpts.inc"
57 #undef OPTION
58 };
59 
60 #define PREFIX(NAME, VALUE) const char *const OBJCOPY_##NAME[] = VALUE;
61 #include "ObjcopyOpts.inc"
62 #undef PREFIX
63 
64 static const opt::OptTable::Info ObjcopyInfoTable[] = {
65 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
66                HELPTEXT, METAVAR, VALUES)                                      \
67   {OBJCOPY_##PREFIX,                                                           \
68    NAME,                                                                       \
69    HELPTEXT,                                                                   \
70    METAVAR,                                                                    \
71    OBJCOPY_##ID,                                                               \
72    opt::Option::KIND##Class,                                                   \
73    PARAM,                                                                      \
74    FLAGS,                                                                      \
75    OBJCOPY_##GROUP,                                                            \
76    OBJCOPY_##ALIAS,                                                            \
77    ALIASARGS,                                                                  \
78    VALUES},
79 #include "ObjcopyOpts.inc"
80 #undef OPTION
81 };
82 
83 class ObjcopyOptTable : public opt::OptTable {
84 public:
85   ObjcopyOptTable() : OptTable(ObjcopyInfoTable, true) {}
86 };
87 
88 enum StripID {
89   STRIP_INVALID = 0, // This is not an option ID.
90 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
91                HELPTEXT, METAVAR, VALUES)                                      \
92   STRIP_##ID,
93 #include "StripOpts.inc"
94 #undef OPTION
95 };
96 
97 #define PREFIX(NAME, VALUE) const char *const STRIP_##NAME[] = VALUE;
98 #include "StripOpts.inc"
99 #undef PREFIX
100 
101 static const opt::OptTable::Info StripInfoTable[] = {
102 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
103                HELPTEXT, METAVAR, VALUES)                                      \
104   {STRIP_##PREFIX, NAME,       HELPTEXT,                                       \
105    METAVAR,        STRIP_##ID, opt::Option::KIND##Class,                       \
106    PARAM,          FLAGS,      STRIP_##GROUP,                                  \
107    STRIP_##ALIAS,  ALIASARGS,  VALUES},
108 #include "StripOpts.inc"
109 #undef OPTION
110 };
111 
112 class StripOptTable : public opt::OptTable {
113 public:
114   StripOptTable() : OptTable(StripInfoTable, true) {}
115 };
116 
117 } // namespace
118 
119 // The name this program was invoked as.
120 static StringRef ToolName;
121 
122 namespace llvm {
123 
124 LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
125   errs() << ToolName << ": " << Message << ".\n";
126   errs().flush();
127   exit(1);
128 }
129 
130 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, std::error_code EC) {
131   assert(EC);
132   errs() << ToolName << ": '" << File << "': " << EC.message() << ".\n";
133   exit(1);
134 }
135 
136 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, Error E) {
137   assert(E);
138   std::string Buf;
139   raw_string_ostream OS(Buf);
140   logAllUnhandledErrors(std::move(E), OS, "");
141   OS.flush();
142   errs() << ToolName << ": '" << File << "': " << Buf;
143   exit(1);
144 }
145 
146 } // end namespace llvm
147 
148 struct CopyConfig {
149   StringRef OutputFilename;
150   StringRef InputFilename;
151   StringRef OutputFormat;
152   StringRef InputFormat;
153   StringRef BinaryArch;
154 
155   StringRef SplitDWO;
156   StringRef AddGnuDebugLink;
157   std::vector<StringRef> ToRemove;
158   std::vector<StringRef> Keep;
159   std::vector<StringRef> OnlyKeep;
160   std::vector<StringRef> AddSection;
161   std::vector<StringRef> SymbolsToLocalize;
162   std::vector<StringRef> SymbolsToGlobalize;
163   std::vector<StringRef> SymbolsToWeaken;
164   std::vector<StringRef> SymbolsToRemove;
165   std::vector<StringRef> SymbolsToKeep;
166   StringMap<StringRef> SymbolsToRename;
167   bool StripAll = false;
168   bool StripAllGNU = false;
169   bool StripDebug = false;
170   bool StripSections = false;
171   bool StripNonAlloc = false;
172   bool StripDWO = false;
173   bool StripUnneeded = false;
174   bool ExtractDWO = false;
175   bool LocalizeHidden = false;
176   bool Weaken = false;
177   bool DiscardAll = false;
178   bool OnlyKeepDebug = false;
179   bool KeepFileSymbols = false;
180 };
181 
182 using SectionPred = std::function<bool(const SectionBase &Sec)>;
183 
184 bool IsDWOSection(const SectionBase &Sec) { return Sec.Name.endswith(".dwo"); }
185 
186 bool OnlyKeepDWOPred(const Object &Obj, const SectionBase &Sec) {
187   // We can't remove the section header string table.
188   if (&Sec == Obj.SectionNames)
189     return false;
190   // Short of keeping the string table we want to keep everything that is a DWO
191   // section and remove everything else.
192   return !IsDWOSection(Sec);
193 }
194 
195 std::unique_ptr<Writer> CreateWriter(const CopyConfig &Config, Object &Obj,
196                                      Buffer &Buf, ElfType OutputElfType) {
197   if (Config.OutputFormat == "binary") {
198     return llvm::make_unique<BinaryWriter>(Obj, Buf);
199   }
200   // Depending on the initial ELFT and OutputFormat we need a different Writer.
201   switch (OutputElfType) {
202   case ELFT_ELF32LE:
203     return llvm::make_unique<ELFWriter<ELF32LE>>(Obj, Buf,
204                                                  !Config.StripSections);
205   case ELFT_ELF64LE:
206     return llvm::make_unique<ELFWriter<ELF64LE>>(Obj, Buf,
207                                                  !Config.StripSections);
208   case ELFT_ELF32BE:
209     return llvm::make_unique<ELFWriter<ELF32BE>>(Obj, Buf,
210                                                  !Config.StripSections);
211   case ELFT_ELF64BE:
212     return llvm::make_unique<ELFWriter<ELF64BE>>(Obj, Buf,
213                                                  !Config.StripSections);
214   }
215   llvm_unreachable("Invalid output format");
216 }
217 
218 void SplitDWOToFile(const CopyConfig &Config, const Reader &Reader,
219                     StringRef File, ElfType OutputElfType) {
220   auto DWOFile = Reader.create();
221   DWOFile->removeSections(
222       [&](const SectionBase &Sec) { return OnlyKeepDWOPred(*DWOFile, Sec); });
223   FileBuffer FB(File);
224   auto Writer = CreateWriter(Config, *DWOFile, FB, OutputElfType);
225   Writer->finalize();
226   Writer->write();
227 }
228 
229 // This function handles the high level operations of GNU objcopy including
230 // handling command line options. It's important to outline certain properties
231 // we expect to hold of the command line operations. Any operation that "keeps"
232 // should keep regardless of a remove. Additionally any removal should respect
233 // any previous removals. Lastly whether or not something is removed shouldn't
234 // depend a) on the order the options occur in or b) on some opaque priority
235 // system. The only priority is that keeps/copies overrule removes.
236 void HandleArgs(const CopyConfig &Config, Object &Obj, const Reader &Reader,
237                 ElfType OutputElfType) {
238 
239   if (!Config.SplitDWO.empty()) {
240     SplitDWOToFile(Config, Reader, Config.SplitDWO, OutputElfType);
241   }
242 
243   // TODO: update or remove symbols only if there is an option that affects
244   // them.
245   if (Obj.SymbolTable) {
246     Obj.SymbolTable->updateSymbols([&](Symbol &Sym) {
247       if ((Config.LocalizeHidden &&
248            (Sym.Visibility == STV_HIDDEN || Sym.Visibility == STV_INTERNAL)) ||
249           (!Config.SymbolsToLocalize.empty() &&
250            is_contained(Config.SymbolsToLocalize, Sym.Name)))
251         Sym.Binding = STB_LOCAL;
252 
253       if (!Config.SymbolsToGlobalize.empty() &&
254           is_contained(Config.SymbolsToGlobalize, Sym.Name))
255         Sym.Binding = STB_GLOBAL;
256 
257       if (!Config.SymbolsToWeaken.empty() &&
258           is_contained(Config.SymbolsToWeaken, Sym.Name) &&
259           Sym.Binding == STB_GLOBAL)
260         Sym.Binding = STB_WEAK;
261 
262       if (Config.Weaken && Sym.Binding == STB_GLOBAL &&
263           Sym.getShndx() != SHN_UNDEF)
264         Sym.Binding = STB_WEAK;
265 
266       const auto I = Config.SymbolsToRename.find(Sym.Name);
267       if (I != Config.SymbolsToRename.end())
268         Sym.Name = I->getValue();
269     });
270 
271     // The purpose of this loop is to mark symbols referenced by sections
272     // (like GroupSection or RelocationSection). This way, we know which
273     // symbols are still 'needed' and wich are not.
274     if (Config.StripUnneeded) {
275       for (auto &Section : Obj.sections())
276         Section.markSymbols();
277     }
278 
279     Obj.removeSymbols([&](const Symbol &Sym) {
280       if ((!Config.SymbolsToKeep.empty() &&
281            is_contained(Config.SymbolsToKeep, Sym.Name)) ||
282           (Config.KeepFileSymbols && Sym.Type == STT_FILE))
283         return false;
284 
285       if (Config.DiscardAll && Sym.Binding == STB_LOCAL &&
286           Sym.getShndx() != SHN_UNDEF && Sym.Type != STT_FILE &&
287           Sym.Type != STT_SECTION)
288         return true;
289 
290       if (Config.StripAll || Config.StripAllGNU)
291         return true;
292 
293       if (!Config.SymbolsToRemove.empty() &&
294           is_contained(Config.SymbolsToRemove, Sym.Name)) {
295         return true;
296       }
297 
298       if (Config.StripUnneeded && !Sym.Referenced &&
299           (Sym.Binding == STB_LOCAL || Sym.getShndx() == SHN_UNDEF) &&
300           Sym.Type != STT_FILE && Sym.Type != STT_SECTION)
301         return true;
302 
303       return false;
304     });
305   }
306 
307   SectionPred RemovePred = [](const SectionBase &) { return false; };
308 
309   // Removes:
310   if (!Config.ToRemove.empty()) {
311     RemovePred = [&Config](const SectionBase &Sec) {
312       return std::find(std::begin(Config.ToRemove), std::end(Config.ToRemove),
313                        Sec.Name) != std::end(Config.ToRemove);
314     };
315   }
316 
317   if (Config.StripDWO || !Config.SplitDWO.empty())
318     RemovePred = [RemovePred](const SectionBase &Sec) {
319       return IsDWOSection(Sec) || RemovePred(Sec);
320     };
321 
322   if (Config.ExtractDWO)
323     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
324       return OnlyKeepDWOPred(Obj, Sec) || RemovePred(Sec);
325     };
326 
327   if (Config.StripAllGNU)
328     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
329       if (RemovePred(Sec))
330         return true;
331       if ((Sec.Flags & SHF_ALLOC) != 0)
332         return false;
333       if (&Sec == Obj.SectionNames)
334         return false;
335       switch (Sec.Type) {
336       case SHT_SYMTAB:
337       case SHT_REL:
338       case SHT_RELA:
339       case SHT_STRTAB:
340         return true;
341       }
342       return Sec.Name.startswith(".debug");
343     };
344 
345   if (Config.StripSections) {
346     RemovePred = [RemovePred](const SectionBase &Sec) {
347       return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;
348     };
349   }
350 
351   if (Config.StripDebug) {
352     RemovePred = [RemovePred](const SectionBase &Sec) {
353       return RemovePred(Sec) || Sec.Name.startswith(".debug");
354     };
355   }
356 
357   if (Config.StripNonAlloc)
358     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
359       if (RemovePred(Sec))
360         return true;
361       if (&Sec == Obj.SectionNames)
362         return false;
363       return (Sec.Flags & SHF_ALLOC) == 0;
364     };
365 
366   if (Config.StripAll)
367     RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
368       if (RemovePred(Sec))
369         return true;
370       if (&Sec == Obj.SectionNames)
371         return false;
372       if (Sec.Name.startswith(".gnu.warning"))
373         return false;
374       return (Sec.Flags & SHF_ALLOC) == 0;
375     };
376 
377   // Explicit copies:
378   if (!Config.OnlyKeep.empty()) {
379     RemovePred = [&Config, RemovePred, &Obj](const SectionBase &Sec) {
380       // Explicitly keep these sections regardless of previous removes.
381       if (std::find(std::begin(Config.OnlyKeep), std::end(Config.OnlyKeep),
382                     Sec.Name) != std::end(Config.OnlyKeep))
383         return false;
384 
385       // Allow all implicit removes.
386       if (RemovePred(Sec))
387         return true;
388 
389       // Keep special sections.
390       if (Obj.SectionNames == &Sec)
391         return false;
392       if (Obj.SymbolTable == &Sec || Obj.SymbolTable->getStrTab() == &Sec)
393         return false;
394 
395       // Remove everything else.
396       return true;
397     };
398   }
399 
400   if (!Config.Keep.empty()) {
401     RemovePred = [Config, RemovePred](const SectionBase &Sec) {
402       // Explicitly keep these sections regardless of previous removes.
403       if (std::find(std::begin(Config.Keep), std::end(Config.Keep), Sec.Name) !=
404           std::end(Config.Keep))
405         return false;
406       // Otherwise defer to RemovePred.
407       return RemovePred(Sec);
408     };
409   }
410 
411   // This has to be the last predicate assignment.
412   // If the option --keep-symbol has been specified
413   // and at least one of those symbols is present
414   // (equivalently, the updated symbol table is not empty)
415   // the symbol table and the string table should not be removed.
416   if ((!Config.SymbolsToKeep.empty() || Config.KeepFileSymbols) &&
417       !Obj.SymbolTable->empty()) {
418     RemovePred = [&Obj, RemovePred](const SectionBase &Sec) {
419       if (&Sec == Obj.SymbolTable || &Sec == Obj.SymbolTable->getStrTab())
420         return false;
421       return RemovePred(Sec);
422     };
423   }
424 
425   Obj.removeSections(RemovePred);
426 
427   if (!Config.AddSection.empty()) {
428     for (const auto &Flag : Config.AddSection) {
429       auto SecPair = Flag.split("=");
430       auto SecName = SecPair.first;
431       auto File = SecPair.second;
432       auto BufOrErr = MemoryBuffer::getFile(File);
433       if (!BufOrErr)
434         reportError(File, BufOrErr.getError());
435       auto Buf = std::move(*BufOrErr);
436       auto BufPtr = reinterpret_cast<const uint8_t *>(Buf->getBufferStart());
437       auto BufSize = Buf->getBufferSize();
438       Obj.addSection<OwnedDataSection>(SecName,
439                                        ArrayRef<uint8_t>(BufPtr, BufSize));
440     }
441   }
442 
443   if (!Config.AddGnuDebugLink.empty())
444     Obj.addSection<GnuDebugLinkSection>(Config.AddGnuDebugLink);
445 }
446 
447 void ExecuteElfObjcopyOnBinary(const CopyConfig &Config, Binary &Binary,
448                                Buffer &Out) {
449   ELFReader Reader(&Binary);
450   std::unique_ptr<Object> Obj = Reader.create();
451 
452   HandleArgs(Config, *Obj, Reader, Reader.getElfType());
453 
454   std::unique_ptr<Writer> Writer =
455       CreateWriter(Config, *Obj, Out, Reader.getElfType());
456   Writer->finalize();
457   Writer->write();
458 }
459 
460 // For regular archives this function simply calls llvm::writeArchive,
461 // For thin archives it writes the archive file itself as well as its members.
462 Error deepWriteArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers,
463                        bool WriteSymtab, object::Archive::Kind Kind,
464                        bool Deterministic, bool Thin) {
465   Error E =
466       writeArchive(ArcName, NewMembers, WriteSymtab, Kind, Deterministic, Thin);
467   if (!Thin || E)
468     return E;
469   for (const NewArchiveMember &Member : NewMembers) {
470     // Internally, FileBuffer will use the buffer created by
471     // FileOutputBuffer::create, for regular files (that is the case for
472     // deepWriteArchive) FileOutputBuffer::create will return OnDiskBuffer.
473     // OnDiskBuffer uses a temporary file and then renames it. So in reality
474     // there is no inefficiency / duplicated in-memory buffers in this case. For
475     // now in-memory buffers can not be completely avoided since
476     // NewArchiveMember still requires them even though writeArchive does not
477     // write them on disk.
478     FileBuffer FB(Member.MemberName);
479     FB.allocate(Member.Buf->getBufferSize());
480     std::copy(Member.Buf->getBufferStart(), Member.Buf->getBufferEnd(),
481               FB.getBufferStart());
482     if (auto E = FB.commit())
483       return E;
484   }
485   return Error::success();
486 }
487 
488 void ExecuteElfObjcopyOnArchive(const CopyConfig &Config, const Archive &Ar) {
489   std::vector<NewArchiveMember> NewArchiveMembers;
490   Error Err = Error::success();
491   for (const Archive::Child &Child : Ar.children(Err)) {
492     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
493     if (!ChildOrErr)
494       reportError(Ar.getFileName(), ChildOrErr.takeError());
495     Expected<StringRef> ChildNameOrErr = Child.getName();
496     if (!ChildNameOrErr)
497       reportError(Ar.getFileName(), ChildNameOrErr.takeError());
498 
499     MemBuffer MB(ChildNameOrErr.get());
500     ExecuteElfObjcopyOnBinary(Config, **ChildOrErr, MB);
501 
502     Expected<NewArchiveMember> Member =
503         NewArchiveMember::getOldMember(Child, true);
504     if (!Member)
505       reportError(Ar.getFileName(), Member.takeError());
506     Member->Buf = MB.releaseMemoryBuffer();
507     Member->MemberName = Member->Buf->getBufferIdentifier();
508     NewArchiveMembers.push_back(std::move(*Member));
509   }
510 
511   if (Err)
512     reportError(Config.InputFilename, std::move(Err));
513   if (Error E =
514           deepWriteArchive(Config.OutputFilename, NewArchiveMembers,
515                            Ar.hasSymbolTable(), Ar.kind(), true, Ar.isThin()))
516     reportError(Config.OutputFilename, std::move(E));
517 }
518 
519 void ExecuteElfObjcopy(const CopyConfig &Config) {
520   Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
521       createBinary(Config.InputFilename);
522   if (!BinaryOrErr)
523     reportError(Config.InputFilename, BinaryOrErr.takeError());
524 
525   if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary()))
526     return ExecuteElfObjcopyOnArchive(Config, *Ar);
527 
528   FileBuffer FB(Config.OutputFilename);
529   ExecuteElfObjcopyOnBinary(Config, *BinaryOrErr.get().getBinary(), FB);
530 }
531 
532 // ParseObjcopyOptions returns the config and sets the input arguments. If a
533 // help flag is set then ParseObjcopyOptions will print the help messege and
534 // exit.
535 CopyConfig ParseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
536   ObjcopyOptTable T;
537   unsigned MissingArgumentIndex, MissingArgumentCount;
538   llvm::opt::InputArgList InputArgs =
539       T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
540 
541   if (InputArgs.size() == 0) {
542     T.PrintHelp(errs(), "llvm-objcopy <input> [ <output> ]", "objcopy tool");
543     exit(1);
544   }
545 
546   if (InputArgs.hasArg(OBJCOPY_help)) {
547     T.PrintHelp(outs(), "llvm-objcopy <input> [ <output> ]", "objcopy tool");
548     exit(0);
549   }
550 
551   SmallVector<const char *, 2> Positional;
552 
553   for (auto Arg : InputArgs.filtered(OBJCOPY_UNKNOWN))
554     error("unknown argument '" + Arg->getAsString(InputArgs) + "'");
555 
556   for (auto Arg : InputArgs.filtered(OBJCOPY_INPUT))
557     Positional.push_back(Arg->getValue());
558 
559   if (Positional.empty())
560     error("No input file specified");
561 
562   if (Positional.size() > 2)
563     error("Too many positional arguments");
564 
565   CopyConfig Config;
566   Config.InputFilename = Positional[0];
567   Config.OutputFilename = Positional[Positional.size() == 1 ? 0 : 1];
568   Config.InputFormat = InputArgs.getLastArgValue(OBJCOPY_input_target);
569   Config.OutputFormat = InputArgs.getLastArgValue(OBJCOPY_output_target);
570   Config.BinaryArch = InputArgs.getLastArgValue(OBJCOPY_binary_architecture);
571 
572   Config.SplitDWO = InputArgs.getLastArgValue(OBJCOPY_split_dwo);
573   Config.AddGnuDebugLink = InputArgs.getLastArgValue(OBJCOPY_add_gnu_debuglink);
574 
575   for (auto Arg : InputArgs.filtered(OBJCOPY_redefine_symbol)) {
576     if (!StringRef(Arg->getValue()).contains('='))
577       error("Bad format for --redefine-sym");
578     auto Old2New = StringRef(Arg->getValue()).split('=');
579     if (!Config.SymbolsToRename.insert(Old2New).second)
580       error("Multiple redefinition of symbol " + Old2New.first);
581   }
582 
583   for (auto Arg : InputArgs.filtered(OBJCOPY_remove_section))
584     Config.ToRemove.push_back(Arg->getValue());
585   for (auto Arg : InputArgs.filtered(OBJCOPY_keep))
586     Config.Keep.push_back(Arg->getValue());
587   for (auto Arg : InputArgs.filtered(OBJCOPY_only_keep))
588     Config.OnlyKeep.push_back(Arg->getValue());
589   for (auto Arg : InputArgs.filtered(OBJCOPY_add_section))
590     Config.AddSection.push_back(Arg->getValue());
591   Config.StripAll = InputArgs.hasArg(OBJCOPY_strip_all);
592   Config.StripAllGNU = InputArgs.hasArg(OBJCOPY_strip_all_gnu);
593   Config.StripDebug = InputArgs.hasArg(OBJCOPY_strip_debug);
594   Config.StripDWO = InputArgs.hasArg(OBJCOPY_strip_dwo);
595   Config.StripSections = InputArgs.hasArg(OBJCOPY_strip_sections);
596   Config.StripNonAlloc = InputArgs.hasArg(OBJCOPY_strip_non_alloc);
597   Config.StripUnneeded = InputArgs.hasArg(OBJCOPY_strip_unneeded);
598   Config.ExtractDWO = InputArgs.hasArg(OBJCOPY_extract_dwo);
599   Config.LocalizeHidden = InputArgs.hasArg(OBJCOPY_localize_hidden);
600   Config.Weaken = InputArgs.hasArg(OBJCOPY_weaken);
601   Config.DiscardAll = InputArgs.hasArg(OBJCOPY_discard_all);
602   Config.OnlyKeepDebug = InputArgs.hasArg(OBJCOPY_only_keep_debug);
603   Config.KeepFileSymbols = InputArgs.hasArg(OBJCOPY_keep_file_symbols);
604   for (auto Arg : InputArgs.filtered(OBJCOPY_localize_symbol))
605     Config.SymbolsToLocalize.push_back(Arg->getValue());
606   for (auto Arg : InputArgs.filtered(OBJCOPY_globalize_symbol))
607     Config.SymbolsToGlobalize.push_back(Arg->getValue());
608   for (auto Arg : InputArgs.filtered(OBJCOPY_weaken_symbol))
609     Config.SymbolsToWeaken.push_back(Arg->getValue());
610   for (auto Arg : InputArgs.filtered(OBJCOPY_strip_symbol))
611     Config.SymbolsToRemove.push_back(Arg->getValue());
612   for (auto Arg : InputArgs.filtered(OBJCOPY_keep_symbol))
613     Config.SymbolsToKeep.push_back(Arg->getValue());
614 
615   return Config;
616 }
617 
618 // ParseStripOptions returns the config and sets the input arguments. If a
619 // help flag is set then ParseStripOptions will print the help messege and
620 // exit.
621 CopyConfig ParseStripOptions(ArrayRef<const char *> ArgsArr) {
622   StripOptTable T;
623   unsigned MissingArgumentIndex, MissingArgumentCount;
624   llvm::opt::InputArgList InputArgs =
625       T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
626 
627   if (InputArgs.size() == 0) {
628     T.PrintHelp(errs(), "llvm-strip <input> [ <output> ]", "strip tool");
629     exit(1);
630   }
631 
632   if (InputArgs.hasArg(STRIP_help)) {
633     T.PrintHelp(outs(), "llvm-strip <input> [ <output> ]", "strip tool");
634     exit(0);
635   }
636 
637   SmallVector<const char *, 2> Positional;
638   for (auto Arg : InputArgs.filtered(STRIP_UNKNOWN))
639     error("unknown argument '" + Arg->getAsString(InputArgs) + "'");
640   for (auto Arg : InputArgs.filtered(STRIP_INPUT))
641     Positional.push_back(Arg->getValue());
642 
643   if (Positional.empty())
644     error("No input file specified");
645 
646   if (Positional.size() > 2)
647     error("Support for multiple input files is not implemented yet");
648 
649   CopyConfig Config;
650   Config.InputFilename = Positional[0];
651   Config.OutputFilename =
652       InputArgs.getLastArgValue(STRIP_output, Positional[0]);
653 
654   Config.StripDebug = InputArgs.hasArg(STRIP_strip_debug);
655 
656   Config.DiscardAll = InputArgs.hasArg(STRIP_discard_all);
657   Config.StripUnneeded = InputArgs.hasArg(STRIP_strip_unneeded);
658   Config.StripAll = InputArgs.hasArg(STRIP_strip_all);
659 
660   if (!Config.StripDebug && !Config.StripUnneeded && !Config.DiscardAll)
661     Config.StripAll = true;
662 
663   for (auto Arg : InputArgs.filtered(STRIP_remove_section))
664     Config.ToRemove.push_back(Arg->getValue());
665 
666   for (auto Arg : InputArgs.filtered(STRIP_keep_symbol))
667     Config.SymbolsToKeep.push_back(Arg->getValue());
668 
669   return Config;
670 }
671 
672 int main(int argc, char **argv) {
673   InitLLVM X(argc, argv);
674   ToolName = argv[0];
675   CopyConfig Config;
676   if (sys::path::stem(ToolName).endswith_lower("strip"))
677     Config = ParseStripOptions(makeArrayRef(argv + 1, argc));
678   else
679     Config = ParseObjcopyOptions(makeArrayRef(argv + 1, argc));
680   ExecuteElfObjcopy(Config);
681 }
682