145afe016bed87b9c6946184709058b39ede3f77ajwong@chromium.org//===-- llvm-ar.cpp - LLVM archive librarian utility ----------------------===//
245afe016bed87b9c6946184709058b39ede3f77ajwong@chromium.org//
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// Builds up (relatively) standard unix archive files (.a) containing LLVM
11// bitcode or other files.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/IR/LLVMContext.h"
16#include "llvm/IR/Module.h"
17#include "llvm/Object/Archive.h"
18#include "llvm/Object/ObjectFile.h"
19#include "llvm/Support/CommandLine.h"
20#include "llvm/Support/Errc.h"
21#include "llvm/Support/FileSystem.h"
22#include "llvm/Support/Format.h"
23#include "llvm/Support/ManagedStatic.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include "llvm/Support/PrettyStackTrace.h"
26#include "llvm/Support/Signals.h"
27#include "llvm/Support/TargetSelect.h"
28#include "llvm/Support/ToolOutputFile.h"
29#include "llvm/Support/raw_ostream.h"
30#include <algorithm>
31#include <cstdlib>
32#include <memory>
33
34#if !defined(_MSC_VER) && !defined(__MINGW32__)
35#include <unistd.h>
36#else
37#include <io.h>
38#endif
39
40using namespace llvm;
41
42// The name this program was invoked as.
43static StringRef ToolName;
44
45static const char *TemporaryOutput;
46static int TmpArchiveFD = -1;
47
48// fail - Show the error message and exit.
49LLVM_ATTRIBUTE_NORETURN static void fail(Twine Error) {
50  outs() << ToolName << ": " << Error << ".\n";
51  if (TmpArchiveFD != -1)
52    close(TmpArchiveFD);
53  if (TemporaryOutput)
54    sys::fs::remove(TemporaryOutput);
55  exit(1);
56}
57
58static void failIfError(std::error_code EC, Twine Context = "") {
59  if (!EC)
60    return;
61
62  std::string ContextStr = Context.str();
63  if (ContextStr == "")
64    fail(EC.message());
65  fail(Context + ": " + EC.message());
66}
67
68// llvm-ar/llvm-ranlib remaining positional arguments.
69static cl::list<std::string>
70RestOfArgs(cl::Positional, cl::OneOrMore,
71    cl::desc("[relpos] [count] <archive-file> [members]..."));
72
73std::string Options;
74
75// MoreHelp - Provide additional help output explaining the operations and
76// modifiers of llvm-ar. This object instructs the CommandLine library
77// to print the text of the constructor when the --help option is given.
78static cl::extrahelp MoreHelp(
79  "\nOPERATIONS:\n"
80  "  d[NsS]       - delete file(s) from the archive\n"
81  "  m[abiSs]     - move file(s) in the archive\n"
82  "  p[kN]        - print file(s) found in the archive\n"
83  "  q[ufsS]      - quick append file(s) to the archive\n"
84  "  r[abfiuRsS]  - replace or insert file(s) into the archive\n"
85  "  t            - display contents of archive\n"
86  "  x[No]        - extract file(s) from the archive\n"
87  "\nMODIFIERS (operation specific):\n"
88  "  [a] - put file(s) after [relpos]\n"
89  "  [b] - put file(s) before [relpos] (same as [i])\n"
90  "  [i] - put file(s) before [relpos] (same as [b])\n"
91  "  [N] - use instance [count] of name\n"
92  "  [o] - preserve original dates\n"
93  "  [s] - create an archive index (cf. ranlib)\n"
94  "  [S] - do not build a symbol table\n"
95  "  [u] - update only files newer than archive contents\n"
96  "\nMODIFIERS (generic):\n"
97  "  [c] - do not warn if the library had to be created\n"
98  "  [v] - be verbose about actions taken\n"
99);
100
101// This enumeration delineates the kinds of operations on an archive
102// that are permitted.
103enum ArchiveOperation {
104  Print,            ///< Print the contents of the archive
105  Delete,           ///< Delete the specified members
106  Move,             ///< Move members to end or as given by {a,b,i} modifiers
107  QuickAppend,      ///< Quickly append to end of archive
108  ReplaceOrInsert,  ///< Replace or Insert members
109  DisplayTable,     ///< Display the table of contents
110  Extract,          ///< Extract files back to file system
111  CreateSymTab      ///< Create a symbol table in an existing archive
112};
113
114// Modifiers to follow operation to vary behavior
115static bool AddAfter = false;      ///< 'a' modifier
116static bool AddBefore = false;     ///< 'b' modifier
117static bool Create = false;        ///< 'c' modifier
118static bool OriginalDates = false; ///< 'o' modifier
119static bool OnlyUpdate = false;    ///< 'u' modifier
120static bool Verbose = false;       ///< 'v' modifier
121static bool Symtab = true;         ///< 's' modifier
122
123// Relative Positional Argument (for insert/move). This variable holds
124// the name of the archive member to which the 'a', 'b' or 'i' modifier
125// refers. Only one of 'a', 'b' or 'i' can be specified so we only need
126// one variable.
127static std::string RelPos;
128
129// This variable holds the name of the archive file as given on the
130// command line.
131static std::string ArchiveName;
132
133// This variable holds the list of member files to proecess, as given
134// on the command line.
135static std::vector<std::string> Members;
136
137// show_help - Show the error message, the help message and exit.
138LLVM_ATTRIBUTE_NORETURN static void
139show_help(const std::string &msg) {
140  errs() << ToolName << ": " << msg << "\n\n";
141  cl::PrintHelpMessage();
142  std::exit(1);
143}
144
145// getRelPos - Extract the member filename from the command line for
146// the [relpos] argument associated with a, b, and i modifiers
147static void getRelPos() {
148  if(RestOfArgs.size() == 0)
149    show_help("Expected [relpos] for a, b, or i modifier");
150  RelPos = RestOfArgs[0];
151  RestOfArgs.erase(RestOfArgs.begin());
152}
153
154static void getOptions() {
155  if(RestOfArgs.size() == 0)
156    show_help("Expected options");
157  Options = RestOfArgs[0];
158  RestOfArgs.erase(RestOfArgs.begin());
159}
160
161// getArchive - Get the archive file name from the command line
162static void getArchive() {
163  if(RestOfArgs.size() == 0)
164    show_help("An archive name must be specified");
165  ArchiveName = RestOfArgs[0];
166  RestOfArgs.erase(RestOfArgs.begin());
167}
168
169// getMembers - Copy over remaining items in RestOfArgs to our Members vector
170// This is just for clarity.
171static void getMembers() {
172  if(RestOfArgs.size() > 0)
173    Members = std::vector<std::string>(RestOfArgs);
174}
175
176// parseCommandLine - Parse the command line options as presented and return the
177// operation specified. Process all modifiers and check to make sure that
178// constraints on modifier/operation pairs have not been violated.
179static ArchiveOperation parseCommandLine() {
180  getOptions();
181
182  // Keep track of number of operations. We can only specify one
183  // per execution.
184  unsigned NumOperations = 0;
185
186  // Keep track of the number of positional modifiers (a,b,i). Only
187  // one can be specified.
188  unsigned NumPositional = 0;
189
190  // Keep track of which operation was requested
191  ArchiveOperation Operation;
192
193  bool MaybeJustCreateSymTab = false;
194
195  for(unsigned i=0; i<Options.size(); ++i) {
196    switch(Options[i]) {
197    case 'd': ++NumOperations; Operation = Delete; break;
198    case 'm': ++NumOperations; Operation = Move ; break;
199    case 'p': ++NumOperations; Operation = Print; break;
200    case 'q': ++NumOperations; Operation = QuickAppend; break;
201    case 'r': ++NumOperations; Operation = ReplaceOrInsert; break;
202    case 't': ++NumOperations; Operation = DisplayTable; break;
203    case 'x': ++NumOperations; Operation = Extract; break;
204    case 'c': Create = true; break;
205    case 'l': /* accepted but unused */ break;
206    case 'o': OriginalDates = true; break;
207    case 's':
208      Symtab = true;
209      MaybeJustCreateSymTab = true;
210      break;
211    case 'S':
212      Symtab = false;
213      break;
214    case 'u': OnlyUpdate = true; break;
215    case 'v': Verbose = true; break;
216    case 'a':
217      getRelPos();
218      AddAfter = true;
219      NumPositional++;
220      break;
221    case 'b':
222      getRelPos();
223      AddBefore = true;
224      NumPositional++;
225      break;
226    case 'i':
227      getRelPos();
228      AddBefore = true;
229      NumPositional++;
230      break;
231    default:
232      cl::PrintHelpMessage();
233    }
234  }
235
236  // At this point, the next thing on the command line must be
237  // the archive name.
238  getArchive();
239
240  // Everything on the command line at this point is a member.
241  getMembers();
242
243 if (NumOperations == 0 && MaybeJustCreateSymTab) {
244    NumOperations = 1;
245    Operation = CreateSymTab;
246    if (!Members.empty())
247      show_help("The s operation takes only an archive as argument");
248  }
249
250  // Perform various checks on the operation/modifier specification
251  // to make sure we are dealing with a legal request.
252  if (NumOperations == 0)
253    show_help("You must specify at least one of the operations");
254  if (NumOperations > 1)
255    show_help("Only one operation may be specified");
256  if (NumPositional > 1)
257    show_help("You may only specify one of a, b, and i modifiers");
258  if (AddAfter || AddBefore) {
259    if (Operation != Move && Operation != ReplaceOrInsert)
260      show_help("The 'a', 'b' and 'i' modifiers can only be specified with "
261            "the 'm' or 'r' operations");
262  }
263  if (OriginalDates && Operation != Extract)
264    show_help("The 'o' modifier is only applicable to the 'x' operation");
265  if (OnlyUpdate && Operation != ReplaceOrInsert)
266    show_help("The 'u' modifier is only applicable to the 'r' operation");
267
268  // Return the parsed operation to the caller
269  return Operation;
270}
271
272// Implements the 'p' operation. This function traverses the archive
273// looking for members that match the path list.
274static void doPrint(StringRef Name, object::Archive::child_iterator I) {
275  if (Verbose)
276    outs() << "Printing " << Name << "\n";
277
278  StringRef Data = I->getBuffer();
279  outs().write(Data.data(), Data.size());
280}
281
282// putMode - utility function for printing out the file mode when the 't'
283// operation is in verbose mode.
284static void printMode(unsigned mode) {
285  if (mode & 004)
286    outs() << "r";
287  else
288    outs() << "-";
289  if (mode & 002)
290    outs() << "w";
291  else
292    outs() << "-";
293  if (mode & 001)
294    outs() << "x";
295  else
296    outs() << "-";
297}
298
299// Implement the 't' operation. This function prints out just
300// the file names of each of the members. However, if verbose mode is requested
301// ('v' modifier) then the file type, permission mode, user, group, size, and
302// modification time are also printed.
303static void doDisplayTable(StringRef Name, object::Archive::child_iterator I) {
304  if (Verbose) {
305    sys::fs::perms Mode = I->getAccessMode();
306    printMode((Mode >> 6) & 007);
307    printMode((Mode >> 3) & 007);
308    printMode(Mode & 007);
309    outs() << ' ' << I->getUID();
310    outs() << '/' << I->getGID();
311    outs() << ' ' << format("%6llu", I->getSize());
312    outs() << ' ' << I->getLastModified().str();
313    outs() << ' ';
314  }
315  outs() << Name << "\n";
316}
317
318// Implement the 'x' operation. This function extracts files back to the file
319// system.
320static void doExtract(StringRef Name, object::Archive::child_iterator I) {
321  // Retain the original mode.
322  sys::fs::perms Mode = I->getAccessMode();
323  SmallString<128> Storage = Name;
324
325  int FD;
326  failIfError(
327      sys::fs::openFileForWrite(Storage.c_str(), FD, sys::fs::F_None, Mode),
328      Storage.c_str());
329
330  {
331    raw_fd_ostream file(FD, false);
332
333    // Get the data and its length
334    StringRef Data = I->getBuffer();
335
336    // Write the data.
337    file.write(Data.data(), Data.size());
338  }
339
340  // If we're supposed to retain the original modification times, etc. do so
341  // now.
342  if (OriginalDates)
343    failIfError(
344        sys::fs::setLastModificationAndAccessTime(FD, I->getLastModified()));
345
346  if (close(FD))
347    fail("Could not close the file");
348}
349
350static bool shouldCreateArchive(ArchiveOperation Op) {
351  switch (Op) {
352  case Print:
353  case Delete:
354  case Move:
355  case DisplayTable:
356  case Extract:
357  case CreateSymTab:
358    return false;
359
360  case QuickAppend:
361  case ReplaceOrInsert:
362    return true;
363  }
364
365  llvm_unreachable("Missing entry in covered switch.");
366}
367
368static void performReadOperation(ArchiveOperation Operation,
369                                 object::Archive *OldArchive) {
370  for (object::Archive::child_iterator I = OldArchive->child_begin(),
371                                       E = OldArchive->child_end();
372       I != E; ++I) {
373    ErrorOr<StringRef> NameOrErr = I->getName();
374    failIfError(NameOrErr.getError());
375    StringRef Name = NameOrErr.get();
376
377    if (!Members.empty() &&
378        std::find(Members.begin(), Members.end(), Name) == Members.end())
379      continue;
380
381    switch (Operation) {
382    default:
383      llvm_unreachable("Not a read operation");
384    case Print:
385      doPrint(Name, I);
386      break;
387    case DisplayTable:
388      doDisplayTable(Name, I);
389      break;
390    case Extract:
391      doExtract(Name, I);
392      break;
393    }
394  }
395}
396
397namespace {
398class NewArchiveIterator {
399  bool IsNewMember;
400  StringRef Name;
401
402  object::Archive::child_iterator OldI;
403
404  std::string NewFilename;
405  mutable int NewFD;
406  mutable sys::fs::file_status NewStatus;
407
408public:
409  NewArchiveIterator(object::Archive::child_iterator I, StringRef Name);
410  NewArchiveIterator(std::string *I, StringRef Name);
411  NewArchiveIterator();
412  bool isNewMember() const;
413  StringRef getName() const;
414
415  object::Archive::child_iterator getOld() const;
416
417  const char *getNew() const;
418  int getFD() const;
419  const sys::fs::file_status &getStatus() const;
420};
421}
422
423NewArchiveIterator::NewArchiveIterator() {}
424
425NewArchiveIterator::NewArchiveIterator(object::Archive::child_iterator I,
426                                       StringRef Name)
427    : IsNewMember(false), Name(Name), OldI(I) {}
428
429NewArchiveIterator::NewArchiveIterator(std::string *NewFilename, StringRef Name)
430    : IsNewMember(true), Name(Name), NewFilename(*NewFilename), NewFD(-1) {}
431
432StringRef NewArchiveIterator::getName() const { return Name; }
433
434bool NewArchiveIterator::isNewMember() const { return IsNewMember; }
435
436object::Archive::child_iterator NewArchiveIterator::getOld() const {
437  assert(!IsNewMember);
438  return OldI;
439}
440
441const char *NewArchiveIterator::getNew() const {
442  assert(IsNewMember);
443  return NewFilename.c_str();
444}
445
446int NewArchiveIterator::getFD() const {
447  assert(IsNewMember);
448  if (NewFD != -1)
449    return NewFD;
450  failIfError(sys::fs::openFileForRead(NewFilename, NewFD), NewFilename);
451  assert(NewFD != -1);
452
453  failIfError(sys::fs::status(NewFD, NewStatus), NewFilename);
454
455  // Opening a directory doesn't make sense. Let it fail.
456  // Linux cannot open directories with open(2), although
457  // cygwin and *bsd can.
458  if (NewStatus.type() == sys::fs::file_type::directory_file)
459    failIfError(make_error_code(errc::is_a_directory), NewFilename);
460
461  return NewFD;
462}
463
464const sys::fs::file_status &NewArchiveIterator::getStatus() const {
465  assert(IsNewMember);
466  assert(NewFD != -1 && "Must call getFD first");
467  return NewStatus;
468}
469
470template <typename T>
471void addMember(std::vector<NewArchiveIterator> &Members, T I, StringRef Name,
472               int Pos = -1) {
473  NewArchiveIterator NI(I, Name);
474  if (Pos == -1)
475    Members.push_back(NI);
476  else
477    Members[Pos] = NI;
478}
479
480enum InsertAction {
481  IA_AddOldMember,
482  IA_AddNewMeber,
483  IA_Delete,
484  IA_MoveOldMember,
485  IA_MoveNewMember
486};
487
488static InsertAction
489computeInsertAction(ArchiveOperation Operation,
490                    object::Archive::child_iterator I, StringRef Name,
491                    std::vector<std::string>::iterator &Pos) {
492  if (Operation == QuickAppend || Members.empty())
493    return IA_AddOldMember;
494
495  std::vector<std::string>::iterator MI = std::find_if(
496      Members.begin(), Members.end(),
497      [Name](StringRef Path) { return Name == sys::path::filename(Path); });
498
499  if (MI == Members.end())
500    return IA_AddOldMember;
501
502  Pos = MI;
503
504  if (Operation == Delete)
505    return IA_Delete;
506
507  if (Operation == Move)
508    return IA_MoveOldMember;
509
510  if (Operation == ReplaceOrInsert) {
511    StringRef PosName = sys::path::filename(RelPos);
512    if (!OnlyUpdate) {
513      if (PosName.empty())
514        return IA_AddNewMeber;
515      return IA_MoveNewMember;
516    }
517
518    // We could try to optimize this to a fstat, but it is not a common
519    // operation.
520    sys::fs::file_status Status;
521    failIfError(sys::fs::status(*MI, Status), *MI);
522    if (Status.getLastModificationTime() < I->getLastModified()) {
523      if (PosName.empty())
524        return IA_AddOldMember;
525      return IA_MoveOldMember;
526    }
527
528    if (PosName.empty())
529      return IA_AddNewMeber;
530    return IA_MoveNewMember;
531  }
532  llvm_unreachable("No such operation");
533}
534
535// We have to walk this twice and computing it is not trivial, so creating an
536// explicit std::vector is actually fairly efficient.
537static std::vector<NewArchiveIterator>
538computeNewArchiveMembers(ArchiveOperation Operation,
539                         object::Archive *OldArchive) {
540  std::vector<NewArchiveIterator> Ret;
541  std::vector<NewArchiveIterator> Moved;
542  int InsertPos = -1;
543  StringRef PosName = sys::path::filename(RelPos);
544  if (OldArchive) {
545    for (object::Archive::child_iterator I = OldArchive->child_begin(),
546                                         E = OldArchive->child_end();
547         I != E; ++I) {
548      int Pos = Ret.size();
549      ErrorOr<StringRef> NameOrErr = I->getName();
550      failIfError(NameOrErr.getError());
551      StringRef Name = NameOrErr.get();
552      if (Name == PosName) {
553        assert(AddAfter || AddBefore);
554        if (AddBefore)
555          InsertPos = Pos;
556        else
557          InsertPos = Pos + 1;
558      }
559
560      std::vector<std::string>::iterator MemberI = Members.end();
561      InsertAction Action = computeInsertAction(Operation, I, Name, MemberI);
562      switch (Action) {
563      case IA_AddOldMember:
564        addMember(Ret, I, Name);
565        break;
566      case IA_AddNewMeber:
567        addMember(Ret, &*MemberI, Name);
568        break;
569      case IA_Delete:
570        break;
571      case IA_MoveOldMember:
572        addMember(Moved, I, Name);
573        break;
574      case IA_MoveNewMember:
575        addMember(Moved, &*MemberI, Name);
576        break;
577      }
578      if (MemberI != Members.end())
579        Members.erase(MemberI);
580    }
581  }
582
583  if (Operation == Delete)
584    return Ret;
585
586  if (!RelPos.empty() && InsertPos == -1)
587    fail("Insertion point not found");
588
589  if (RelPos.empty())
590    InsertPos = Ret.size();
591
592  assert(unsigned(InsertPos) <= Ret.size());
593  Ret.insert(Ret.begin() + InsertPos, Moved.begin(), Moved.end());
594
595  Ret.insert(Ret.begin() + InsertPos, Members.size(), NewArchiveIterator());
596  int Pos = InsertPos;
597  for (std::vector<std::string>::iterator I = Members.begin(),
598         E = Members.end();
599       I != E; ++I, ++Pos) {
600    StringRef Name = sys::path::filename(*I);
601    addMember(Ret, &*I, Name, Pos);
602  }
603
604  return Ret;
605}
606
607template <typename T>
608static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
609				  bool MayTruncate = false) {
610  uint64_t OldPos = OS.tell();
611  OS << Data;
612  unsigned SizeSoFar = OS.tell() - OldPos;
613  if (Size > SizeSoFar) {
614    unsigned Remaining = Size - SizeSoFar;
615    for (unsigned I = 0; I < Remaining; ++I)
616      OS << ' ';
617  } else if (Size < SizeSoFar) {
618    assert(MayTruncate && "Data doesn't fit in Size");
619    // Some of the data this is used for (like UID) can be larger than the
620    // space available in the archive format. Truncate in that case.
621    OS.seek(OldPos + Size);
622  }
623}
624
625static void print32BE(raw_fd_ostream &Out, unsigned Val) {
626  for (int I = 3; I >= 0; --I) {
627    char V = (Val >> (8 * I)) & 0xff;
628    Out << V;
629  }
630}
631
632static void printRestOfMemberHeader(raw_fd_ostream &Out,
633                                    const sys::TimeValue &ModTime, unsigned UID,
634                                    unsigned GID, unsigned Perms,
635                                    unsigned Size) {
636  printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
637  printWithSpacePadding(Out, UID, 6, true);
638  printWithSpacePadding(Out, GID, 6, true);
639  printWithSpacePadding(Out, format("%o", Perms), 8);
640  printWithSpacePadding(Out, Size, 10);
641  Out << "`\n";
642}
643
644static void printMemberHeader(raw_fd_ostream &Out, StringRef Name,
645                              const sys::TimeValue &ModTime, unsigned UID,
646                              unsigned GID, unsigned Perms, unsigned Size) {
647  printWithSpacePadding(Out, Twine(Name) + "/", 16);
648  printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
649}
650
651static void printMemberHeader(raw_fd_ostream &Out, unsigned NameOffset,
652                              const sys::TimeValue &ModTime, unsigned UID,
653                              unsigned GID, unsigned Perms, unsigned Size) {
654  Out << '/';
655  printWithSpacePadding(Out, NameOffset, 15);
656  printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
657}
658
659static void writeStringTable(raw_fd_ostream &Out,
660                             ArrayRef<NewArchiveIterator> Members,
661                             std::vector<unsigned> &StringMapIndexes) {
662  unsigned StartOffset = 0;
663  for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
664                                              E = Members.end();
665       I != E; ++I) {
666    StringRef Name = I->getName();
667    if (Name.size() < 16)
668      continue;
669    if (StartOffset == 0) {
670      printWithSpacePadding(Out, "//", 58);
671      Out << "`\n";
672      StartOffset = Out.tell();
673    }
674    StringMapIndexes.push_back(Out.tell() - StartOffset);
675    Out << Name << "/\n";
676  }
677  if (StartOffset == 0)
678    return;
679  if (Out.tell() % 2)
680    Out << '\n';
681  int Pos = Out.tell();
682  Out.seek(StartOffset - 12);
683  printWithSpacePadding(Out, Pos - StartOffset, 10);
684  Out.seek(Pos);
685}
686
687static void
688writeSymbolTable(raw_fd_ostream &Out, ArrayRef<NewArchiveIterator> Members,
689                 MutableArrayRef<std::unique_ptr<MemoryBuffer>> Buffers,
690                 std::vector<std::pair<unsigned, unsigned>> &MemberOffsetRefs) {
691  unsigned StartOffset = 0;
692  unsigned MemberNum = 0;
693  std::string NameBuf;
694  raw_string_ostream NameOS(NameBuf);
695  unsigned NumSyms = 0;
696  LLVMContext &Context = getGlobalContext();
697  for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
698                                              E = Members.end();
699       I != E; ++I, ++MemberNum) {
700    std::unique_ptr<MemoryBuffer> &MemberBuffer = Buffers[MemberNum];
701    ErrorOr<object::SymbolicFile *> ObjOrErr =
702        object::SymbolicFile::createSymbolicFile(
703            MemberBuffer, sys::fs::file_magic::unknown, &Context);
704    if (!ObjOrErr)
705      continue;  // FIXME: check only for "not an object file" errors.
706    std::unique_ptr<object::SymbolicFile> Obj(ObjOrErr.get());
707
708    if (!StartOffset) {
709      printMemberHeader(Out, "", sys::TimeValue::now(), 0, 0, 0, 0);
710      StartOffset = Out.tell();
711      print32BE(Out, 0);
712    }
713
714    for (const object::BasicSymbolRef &S : Obj->symbols()) {
715      uint32_t Symflags = S.getFlags();
716      if (Symflags & object::SymbolRef::SF_FormatSpecific)
717        continue;
718      if (!(Symflags & object::SymbolRef::SF_Global))
719        continue;
720      if (Symflags & object::SymbolRef::SF_Undefined)
721        continue;
722      failIfError(S.printName(NameOS));
723      NameOS << '\0';
724      ++NumSyms;
725      MemberOffsetRefs.push_back(std::make_pair(Out.tell(), MemberNum));
726      print32BE(Out, 0);
727    }
728    MemberBuffer.reset(Obj->releaseBuffer());
729  }
730  Out << NameOS.str();
731
732  if (StartOffset == 0)
733    return;
734
735  if (Out.tell() % 2)
736    Out << '\0';
737
738  unsigned Pos = Out.tell();
739  Out.seek(StartOffset - 12);
740  printWithSpacePadding(Out, Pos - StartOffset, 10);
741  Out.seek(StartOffset);
742  print32BE(Out, NumSyms);
743  Out.seek(Pos);
744}
745
746static void performWriteOperation(ArchiveOperation Operation,
747                                  object::Archive *OldArchive) {
748  SmallString<128> TmpArchive;
749  failIfError(sys::fs::createUniqueFile(ArchiveName + ".temp-archive-%%%%%%%.a",
750                                        TmpArchiveFD, TmpArchive));
751
752  TemporaryOutput = TmpArchive.c_str();
753  tool_output_file Output(TemporaryOutput, TmpArchiveFD);
754  raw_fd_ostream &Out = Output.os();
755  Out << "!<arch>\n";
756
757  std::vector<NewArchiveIterator> NewMembers =
758      computeNewArchiveMembers(Operation, OldArchive);
759
760  std::vector<std::pair<unsigned, unsigned> > MemberOffsetRefs;
761
762  std::vector<std::unique_ptr<MemoryBuffer>> MemberBuffers;
763  MemberBuffers.resize(NewMembers.size());
764
765  for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
766    std::unique_ptr<MemoryBuffer> MemberBuffer;
767    NewArchiveIterator &Member = NewMembers[I];
768
769    if (Member.isNewMember()) {
770      const char *Filename = Member.getNew();
771      int FD = Member.getFD();
772      const sys::fs::file_status &Status = Member.getStatus();
773      ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
774          MemoryBuffer::getOpenFile(FD, Filename, Status.getSize(), false);
775      failIfError(MemberBufferOrErr.getError(), Filename);
776      MemberBuffer = std::move(MemberBufferOrErr.get());
777    } else {
778      object::Archive::child_iterator OldMember = Member.getOld();
779      ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
780          OldMember->getMemoryBuffer();
781      failIfError(MemberBufferOrErr.getError());
782      MemberBuffer = std::move(MemberBufferOrErr.get());
783    }
784    MemberBuffers[I].reset(MemberBuffer.release());
785  }
786
787  if (Symtab) {
788    writeSymbolTable(Out, NewMembers, MemberBuffers, MemberOffsetRefs);
789  }
790
791  std::vector<unsigned> StringMapIndexes;
792  writeStringTable(Out, NewMembers, StringMapIndexes);
793
794  std::vector<std::pair<unsigned, unsigned> >::iterator MemberRefsI =
795      MemberOffsetRefs.begin();
796
797  unsigned MemberNum = 0;
798  unsigned LongNameMemberNum = 0;
799  for (std::vector<NewArchiveIterator>::iterator I = NewMembers.begin(),
800                                                 E = NewMembers.end();
801       I != E; ++I, ++MemberNum) {
802
803    unsigned Pos = Out.tell();
804    while (MemberRefsI != MemberOffsetRefs.end() &&
805           MemberRefsI->second == MemberNum) {
806      Out.seek(MemberRefsI->first);
807      print32BE(Out, Pos);
808      ++MemberRefsI;
809    }
810    Out.seek(Pos);
811
812    const MemoryBuffer *File = MemberBuffers[MemberNum].get();
813    if (I->isNewMember()) {
814      const char *FileName = I->getNew();
815      const sys::fs::file_status &Status = I->getStatus();
816
817      StringRef Name = sys::path::filename(FileName);
818      if (Name.size() < 16)
819        printMemberHeader(Out, Name, Status.getLastModificationTime(),
820                          Status.getUser(), Status.getGroup(),
821                          Status.permissions(), Status.getSize());
822      else
823        printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
824                          Status.getLastModificationTime(), Status.getUser(),
825                          Status.getGroup(), Status.permissions(),
826                          Status.getSize());
827    } else {
828      object::Archive::child_iterator OldMember = I->getOld();
829      StringRef Name = I->getName();
830
831      if (Name.size() < 16)
832        printMemberHeader(Out, Name, OldMember->getLastModified(),
833                          OldMember->getUID(), OldMember->getGID(),
834                          OldMember->getAccessMode(), OldMember->getSize());
835      else
836        printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
837                          OldMember->getLastModified(), OldMember->getUID(),
838                          OldMember->getGID(), OldMember->getAccessMode(),
839                          OldMember->getSize());
840    }
841
842    Out << File->getBuffer();
843
844    if (Out.tell() % 2)
845      Out << '\n';
846  }
847
848  Output.keep();
849  Out.close();
850  sys::fs::rename(TemporaryOutput, ArchiveName);
851  TemporaryOutput = nullptr;
852}
853
854static void createSymbolTable(object::Archive *OldArchive) {
855  // When an archive is created or modified, if the s option is given, the
856  // resulting archive will have a current symbol table. If the S option
857  // is given, it will have no symbol table.
858  // In summary, we only need to update the symbol table if we have none.
859  // This is actually very common because of broken build systems that think
860  // they have to run ranlib.
861  if (OldArchive->hasSymbolTable())
862    return;
863
864  performWriteOperation(CreateSymTab, OldArchive);
865}
866
867static void performOperation(ArchiveOperation Operation,
868                             object::Archive *OldArchive) {
869  switch (Operation) {
870  case Print:
871  case DisplayTable:
872  case Extract:
873    performReadOperation(Operation, OldArchive);
874    return;
875
876  case Delete:
877  case Move:
878  case QuickAppend:
879  case ReplaceOrInsert:
880    performWriteOperation(Operation, OldArchive);
881    return;
882  case CreateSymTab:
883    createSymbolTable(OldArchive);
884    return;
885  }
886  llvm_unreachable("Unknown operation.");
887}
888
889static int ar_main(char **argv);
890static int ranlib_main();
891
892// main - main program for llvm-ar .. see comments in the code
893int main(int argc, char **argv) {
894  ToolName = argv[0];
895  // Print a stack trace if we signal out.
896  sys::PrintStackTraceOnErrorSignal();
897  PrettyStackTraceProgram X(argc, argv);
898  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
899
900  // Have the command line options parsed and handle things
901  // like --help and --version.
902  cl::ParseCommandLineOptions(argc, argv,
903    "LLVM Archiver (llvm-ar)\n\n"
904    "  This program archives bitcode files into single libraries\n"
905  );
906
907  llvm::InitializeAllTargetInfos();
908  llvm::InitializeAllTargetMCs();
909  llvm::InitializeAllAsmParsers();
910
911  StringRef Stem = sys::path::stem(ToolName);
912  if (Stem.find("ar") != StringRef::npos)
913    return ar_main(argv);
914  if (Stem.find("ranlib") != StringRef::npos)
915    return ranlib_main();
916  fail("Not ranlib or ar!");
917}
918
919static int performOperation(ArchiveOperation Operation);
920
921int ranlib_main() {
922  if (RestOfArgs.size() != 1)
923    fail(ToolName + "takes just one archive as argument");
924  ArchiveName = RestOfArgs[0];
925  return performOperation(CreateSymTab);
926}
927
928int ar_main(char **argv) {
929  // Do our own parsing of the command line because the CommandLine utility
930  // can't handle the grouped positional parameters without a dash.
931  ArchiveOperation Operation = parseCommandLine();
932  return performOperation(Operation);
933}
934
935static int performOperation(ArchiveOperation Operation) {
936  // Create or open the archive object.
937  ErrorOr<std::unique_ptr<MemoryBuffer>> Buf =
938      MemoryBuffer::getFile(ArchiveName, -1, false);
939  std::error_code EC = Buf.getError();
940  if (EC && EC != errc::no_such_file_or_directory) {
941    errs() << ToolName << ": error opening '" << ArchiveName
942           << "': " << EC.message() << "!\n";
943    return 1;
944  }
945
946  if (!EC) {
947    object::Archive Archive(std::move(Buf.get()), EC);
948
949    if (EC) {
950      errs() << ToolName << ": error loading '" << ArchiveName
951             << "': " << EC.message() << "!\n";
952      return 1;
953    }
954    performOperation(Operation, &Archive);
955    return 0;
956  }
957
958  assert(EC == errc::no_such_file_or_directory);
959
960  if (!shouldCreateArchive(Operation)) {
961    failIfError(EC, Twine("error loading '") + ArchiveName + "'");
962  } else {
963    if (!Create) {
964      // Produce a warning if we should and we're creating the archive
965      errs() << ToolName << ": creating " << ArchiveName << "\n";
966    }
967  }
968
969  performOperation(Operation, nullptr);
970  return 0;
971}
972