tools/llvm-ar/llvm-ar.cpp

   1 //===-- llvm-ar.cpp - LLVM archive librarian utility ----------------------===//
   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 // Builds up (relatively) standard unix archive files (.a) containing LLVM
  11 // bitcode or other files.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/LLVMContext.h"
  16 #include "llvm/Module.h"
  17 #include "llvm/Bitcode/Archive.h"
  18 #include "llvm/Support/CommandLine.h"
  19 #include "llvm/Support/FileSystem.h"
  20 #include "llvm/Support/ManagedStatic.h"
  21 #include "llvm/Support/PrettyStackTrace.h"
  22 #include "llvm/Support/Format.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 #include "llvm/Support/Signals.h"
  25 #include <algorithm>
  26 #include <memory>
  27 #include <fstream>
  28 using namespace llvm;
  29
  30 // Option for compatibility with AIX, not used but must allow it to be present.
  31 static cl::opt<bool>
  32 X32Option ("X32_64", cl::Hidden,
  33             cl::desc("Ignored option for compatibility with AIX"));
  34
  35 // llvm-ar operation code and modifier flags. This must come first.
  36 static cl::opt<std::string>
  37 Options(cl::Positional, cl::Required, cl::desc("{operation}[modifiers]..."));
  38
  39 // llvm-ar remaining positional arguments.
  40 static cl::list<std::string>
  41 RestOfArgs(cl::Positional, cl::OneOrMore,
  42     cl::desc("[relpos] [count] <archive-file> [members]..."));
  43
  44 // MoreHelp - Provide additional help output explaining the operations and
  45 // modifiers of llvm-ar. This object instructs the CommandLine library
  46 // to print the text of the constructor when the --help option is given.
  47 static cl::extrahelp MoreHelp(
  48   "\nOPERATIONS:\n"
  49   "  d[NsS]       - delete file(s) from the archive\n"
  50   "  m[abiSs]     - move file(s) in the archive\n"
  51   "  p[kN]        - print file(s) found in the archive\n"
  52   "  q[ufsS]      - quick append file(s) to the archive\n"
  53   "  r[abfiuzRsS] - replace or insert file(s) into the archive\n"
  54   "  t            - display contents of archive\n"
  55   "  x[No]        - extract file(s) from the archive\n"
  56   "\nMODIFIERS (operation specific):\n"
  57   "  [a] - put file(s) after [relpos]\n"
  58   "  [b] - put file(s) before [relpos] (same as [i])\n"
  59   "  [f] - truncate inserted file names\n"
  60   "  [i] - put file(s) before [relpos] (same as [b])\n"
  61   "  [k] - always print bitcode files (default is to skip them)\n"
  62   "  [N] - use instance [count] of name\n"
  63   "  [o] - preserve original dates\n"
  64   "  [P] - use full path names when matching\n"
  65   "  [R] - recurse through directories when inserting\n"
  66   "  [s] - create an archive index (cf. ranlib)\n"
  67   "  [S] - do not build a symbol table\n"
  68   "  [u] - update only files newer than archive contents\n"
  69   "  [z] - compress files before inserting/extracting\n"
  70   "\nMODIFIERS (generic):\n"
  71   "  [c] - do not warn if the library had to be created\n"
  72   "  [v] - be verbose about actions taken\n"
  73   "  [V] - be *really* verbose about actions taken\n"
  74 );
  75
  76 // This enumeration delineates the kinds of operations on an archive
  77 // that are permitted.
  78 enum ArchiveOperation {
  79   NoOperation,      ///< An operation hasn't been specified
  80   Print,            ///< Print the contents of the archive
  81   Delete,           ///< Delete the specified members
  82   Move,             ///< Move members to end or as given by {a,b,i} modifiers
  83   QuickAppend,      ///< Quickly append to end of archive
  84   ReplaceOrInsert,  ///< Replace or Insert members
  85   DisplayTable,     ///< Display the table of contents
  86   Extract           ///< Extract files back to file system
  87 };
  88
  89 // Modifiers to follow operation to vary behavior
  90 bool AddAfter = false;           ///< 'a' modifier
  91 bool AddBefore = false;          ///< 'b' modifier
  92 bool Create = false;             ///< 'c' modifier
  93 bool TruncateNames = false;      ///< 'f' modifier
  94 bool InsertBefore = false;       ///< 'i' modifier
  95 bool DontSkipBitcode = false;    ///< 'k' modifier
  96 bool UseCount = false;           ///< 'N' modifier
  97 bool OriginalDates = false;      ///< 'o' modifier
  98 bool FullPath = false;           ///< 'P' modifier
  99 bool RecurseDirectories = false; ///< 'R' modifier
 100 bool SymTable = true;            ///< 's' & 'S' modifiers
 101 bool OnlyUpdate = false;         ///< 'u' modifier
 102 bool Verbose = false;            ///< 'v' modifier
 103 bool ReallyVerbose = false;      ///< 'V' modifier
 104 bool Compression = false;        ///< 'z' modifier
 105
 106 // Relative Positional Argument (for insert/move). This variable holds
 107 // the name of the archive member to which the 'a', 'b' or 'i' modifier
 108 // refers. Only one of 'a', 'b' or 'i' can be specified so we only need
 109 // one variable.
 110 std::string RelPos;
 111
 112 // Select which of multiple entries in the archive with the same name should be
 113 // used (specified with -N) for the delete and extract operations.
 114 int Count = 1;
 115
 116 // This variable holds the name of the archive file as given on the
 117 // command line.
 118 std::string ArchiveName;
 119
 120 // This variable holds the list of member files to proecess, as given
 121 // on the command line.
 122 std::vector<std::string> Members;
 123
 124 // This variable holds the (possibly expanded) list of path objects that
 125 // correspond to files we will
 126 std::set<sys::Path> Paths;
 127
 128 // The Archive object to which all the editing operations will be sent.
 129 Archive* TheArchive = 0;
 130
 131 // getRelPos - Extract the member filename from the command line for
 132 // the [relpos] argument associated with a, b, and i modifiers
 133 void getRelPos() {
 134   if(RestOfArgs.size() > 0) {
 135     RelPos = RestOfArgs[0];
 136     RestOfArgs.erase(RestOfArgs.begin());
 137   }
 138   else
 139     throw "Expected [relpos] for a, b, or i modifier";
 140 }
 141
 142 // getCount - Extract the [count] argument associated with the N modifier
 143 // from the command line and check its value.
 144 void getCount() {
 145   if(RestOfArgs.size() > 0) {
 146     Count = atoi(RestOfArgs[0].c_str());
 147     RestOfArgs.erase(RestOfArgs.begin());
 148   }
 149   else
 150     throw "Expected [count] value with N modifier";
 151
 152   // Non-positive counts are not allowed
 153   if (Count < 1)
 154     throw "Invalid [count] value (not a positive integer)";
 155 }
 156
 157 // getArchive - Get the archive file name from the command line
 158 void getArchive() {
 159   if(RestOfArgs.size() > 0) {
 160     ArchiveName = RestOfArgs[0];
 161     RestOfArgs.erase(RestOfArgs.begin());
 162   }
 163   else
 164     throw "An archive name must be specified.";
 165 }
 166
 167 // getMembers - Copy over remaining items in RestOfArgs to our Members vector
 168 // This is just for clarity.
 169 void getMembers() {
 170   if(RestOfArgs.size() > 0)
 171     Members = std::vector<std::string>(RestOfArgs);
 172 }
 173
 174 // parseCommandLine - Parse the command line options as presented and return the
 175 // operation specified. Process all modifiers and check to make sure that
 176 // constraints on modifier/operation pairs have not been violated.
 177 ArchiveOperation parseCommandLine() {
 178
 179   // Keep track of number of operations. We can only specify one
 180   // per execution.
 181   unsigned NumOperations = 0;
 182
 183   // Keep track of the number of positional modifiers (a,b,i). Only
 184   // one can be specified.
 185   unsigned NumPositional = 0;
 186
 187   // Keep track of which operation was requested
 188   ArchiveOperation Operation = NoOperation;
 189
 190   for(unsigned i=0; i<Options.size(); ++i) {
 191     switch(Options[i]) {
 192     case 'd': ++NumOperations; Operation = Delete; break;
 193     case 'm': ++NumOperations; Operation = Move ; break;
 194     case 'p': ++NumOperations; Operation = Print; break;
 195     case 'q': ++NumOperations; Operation = QuickAppend; break;
 196     case 'r': ++NumOperations; Operation = ReplaceOrInsert; break;
 197     case 't': ++NumOperations; Operation = DisplayTable; break;
 198     case 'x': ++NumOperations; Operation = Extract; break;
 199     case 'c': Create = true; break;
 200     case 'f': TruncateNames = true; break;
 201     case 'k': DontSkipBitcode = true; break;
 202     case 'l': /* accepted but unused */ break;
 203     case 'o': OriginalDates = true; break;
 204     case 'P': FullPath = true; break;
 205     case 'R': RecurseDirectories = true; break;
 206     case 's': SymTable = true; break;
 207     case 'S': SymTable = false; break;
 208     case 'u': OnlyUpdate = true; break;
 209     case 'v': Verbose = true; break;
 210     case 'V': Verbose = ReallyVerbose = true; break;
 211     case 'z': Compression = true; break;
 212     case 'a':
 213       getRelPos();
 214       AddAfter = true;
 215       NumPositional++;
 216       break;
 217     case 'b':
 218       getRelPos();
 219       AddBefore = true;
 220       NumPositional++;
 221       break;
 222     case 'i':
 223       getRelPos();
 224       InsertBefore = true;
 225       NumPositional++;
 226       break;
 227     case 'N':
 228       getCount();
 229       UseCount = true;
 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   // Perform various checks on the operation/modifier specification
 244   // to make sure we are dealing with a legal request.
 245   if (NumOperations == 0)
 246     throw "You must specify at least one of the operations";
 247   if (NumOperations > 1)
 248     throw "Only one operation may be specified";
 249   if (NumPositional > 1)
 250     throw "You may only specify one of a, b, and i modifiers";
 251   if (AddAfter || AddBefore || InsertBefore)
 252     if (Operation != Move && Operation != ReplaceOrInsert)
 253       throw "The 'a', 'b' and 'i' modifiers can only be specified with "
 254             "the 'm' or 'r' operations";
 255   if (RecurseDirectories && Operation != ReplaceOrInsert)
 256     throw "The 'R' modifiers is only applicabe to the 'r' operation";
 257   if (OriginalDates && Operation != Extract)
 258     throw "The 'o' modifier is only applicable to the 'x' operation";
 259   if (TruncateNames && Operation!=QuickAppend && Operation!=ReplaceOrInsert)
 260     throw "The 'f' modifier is only applicable to the 'q' and 'r' operations";
 261   if (OnlyUpdate && Operation != ReplaceOrInsert)
 262     throw "The 'u' modifier is only applicable to the 'r' operation";
 263   if (Compression && Operation!=ReplaceOrInsert && Operation!=Extract)
 264     throw "The 'z' modifier is only applicable to the 'r' and 'x' operations";
 265   if (Count > 1 && Members.size() > 1)
 266     throw "Only one member name may be specified with the 'N' modifier";
 267
 268   // Return the parsed operation to the caller
 269   return Operation;
 270 }
 271
 272 // recurseDirectories - Implements the "R" modifier. This function scans through
 273 // the Paths vector (built by buildPaths, below) and replaces any directories it
 274 // finds with all the files in that directory (recursively). It uses the
 275 // sys::Path::getDirectoryContent method to perform the actual directory scans.
 276 bool
 277 recurseDirectories(const sys::Path& path,
 278                    std::set<sys::Path>& result, std::string* ErrMsg) {
 279   result.clear();
 280   if (RecurseDirectories) {
 281     std::set<sys::Path> content;
 282     if (path.getDirectoryContents(content, ErrMsg))
 283       return true;
 284
 285     for (std::set<sys::Path>::iterator I = content.begin(), E = content.end();
 286          I != E; ++I) {
 287       // Make sure it exists and is a directory
 288       sys::PathWithStatus PwS(*I);
 289       const sys::FileStatus *Status = PwS.getFileStatus(false, ErrMsg);
 290       if (!Status)
 291         return true;
 292       if (Status->isDir) {
 293         std::set<sys::Path> moreResults;
 294         if (recurseDirectories(*I, moreResults, ErrMsg))
 295           return true;
 296         result.insert(moreResults.begin(), moreResults.end());
 297       } else {
 298           result.insert(*I);
 299       }
 300     }
 301   }
 302   return false;
 303 }
 304
 305 // buildPaths - Convert the strings in the Members vector to sys::Path objects
 306 // and make sure they are valid and exist exist. This check is only needed for
 307 // the operations that add/replace files to the archive ('q' and 'r')
 308 bool buildPaths(bool checkExistence, std::string* ErrMsg) {
 309   for (unsigned i = 0; i < Members.size(); i++) {
 310     sys::Path aPath;
 311     if (!aPath.set(Members[i]))
 312       throw std::string("File member name invalid: ") + Members[i];
 313     if (checkExistence) {
 314       bool Exists;
 315       if (sys::fs::exists(aPath.str(), Exists) || !Exists)
 316         throw std::string("File does not exist: ") + Members[i];
 317       std::string Err;
 318       sys::PathWithStatus PwS(aPath);
 319       const sys::FileStatus *si = PwS.getFileStatus(false, &Err);
 320       if (!si)
 321         throw Err;
 322       if (si->isDir) {
 323         std::set<sys::Path> dirpaths;
 324         if (recurseDirectories(aPath, dirpaths, ErrMsg))
 325           return true;
 326         Paths.insert(dirpaths.begin(),dirpaths.end());
 327       } else {
 328         Paths.insert(aPath);
 329       }
 330     } else {
 331       Paths.insert(aPath);
 332     }
 333   }
 334   return false;
 335 }
 336
 337 // printSymbolTable - print out the archive's symbol table.
 338 void printSymbolTable() {
 339   outs() << "\nArchive Symbol Table:\n";
 340   const Archive::SymTabType& symtab = TheArchive->getSymbolTable();
 341   for (Archive::SymTabType::const_iterator I=symtab.begin(), E=symtab.end();
 342        I != E; ++I ) {
 343     unsigned offset = TheArchive->getFirstFileOffset() + I->second;
 344     outs() << " " << format("%9u", offset) << "\t" << I->first <<"\n";
 345   }
 346 }
 347
 348 // doPrint - Implements the 'p' operation. This function traverses the archive
 349 // looking for members that match the path list. It is careful to uncompress
 350 // things that should be and to skip bitcode files unless the 'k' modifier was
 351 // given.
 352 bool doPrint(std::string* ErrMsg) {
 353   if (buildPaths(false, ErrMsg))
 354     return true;
 355   unsigned countDown = Count;
 356   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 357        I != E; ++I ) {
 358     if (Paths.empty() ||
 359         (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
 360       if (countDown == 1) {
 361         const char* data = reinterpret_cast<const char*>(I->getData());
 362
 363         // Skip things that don't make sense to print
 364         if (I->isLLVMSymbolTable() || I->isSVR4SymbolTable() ||
 365             I->isBSD4SymbolTable() || (!DontSkipBitcode && I->isBitcode()))
 366           continue;
 367
 368         if (Verbose)
 369           outs() << "Printing " << I->getPath().str() << "\n";
 370
 371         unsigned len = I->getSize();
 372         outs().write(data, len);
 373       } else {
 374         countDown--;
 375       }
 376     }
 377   }
 378   return false;
 379 }
 380
 381 // putMode - utility function for printing out the file mode when the 't'
 382 // operation is in verbose mode.
 383 void
 384 printMode(unsigned mode) {
 385   if (mode & 004)
 386     outs() << "r";
 387   else
 388     outs() << "-";
 389   if (mode & 002)
 390     outs() << "w";
 391   else
 392     outs() << "-";
 393   if (mode & 001)
 394     outs() << "x";
 395   else
 396     outs() << "-";
 397 }
 398
 399 // doDisplayTable - Implement the 't' operation. This function prints out just
 400 // the file names of each of the members. However, if verbose mode is requested
 401 // ('v' modifier) then the file type, permission mode, user, group, size, and
 402 // modification time are also printed.
 403 bool
 404 doDisplayTable(std::string* ErrMsg) {
 405   if (buildPaths(false, ErrMsg))
 406     return true;
 407   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 408        I != E; ++I ) {
 409     if (Paths.empty() ||
 410         (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
 411       if (Verbose) {
 412         // FIXME: Output should be this format:
 413         // Zrw-r--r--  500/ 500    525 Nov  8 17:42 2004 Makefile
 414         if (I->isBitcode())
 415           outs() << "b";
 416         else if (I->isCompressed())
 417           outs() << "Z";
 418         else
 419           outs() << " ";
 420         unsigned mode = I->getMode();
 421         printMode((mode >> 6) & 007);
 422         printMode((mode >> 3) & 007);
 423         printMode(mode & 007);
 424         outs() << " " << format("%4u", I->getUser());
 425         outs() << "/" << format("%4u", I->getGroup());
 426         outs() << " " << format("%8u", I->getSize());
 427         outs() << " " << format("%20s", I->getModTime().str().substr(4).c_str());
 428         outs() << " " << I->getPath().str() << "\n";
 429       } else {
 430         outs() << I->getPath().str() << "\n";
 431       }
 432     }
 433   }
 434   if (ReallyVerbose)
 435     printSymbolTable();
 436   return false;
 437 }
 438
 439 // doExtract - Implement the 'x' operation. This function extracts files back to
 440 // the file system, making sure to uncompress any that were compressed
 441 bool
 442 doExtract(std::string* ErrMsg) {
 443   if (buildPaths(false, ErrMsg))
 444     return true;
 445   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 446        I != E; ++I ) {
 447     if (Paths.empty() ||
 448         (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
 449
 450       // Make sure the intervening directories are created
 451       if (I->hasPath()) {
 452         sys::Path dirs(I->getPath());
 453         dirs.eraseComponent();
 454         if (dirs.createDirectoryOnDisk(/*create_parents=*/true, ErrMsg))
 455           return true;
 456       }
 457
 458       // Open up a file stream for writing
 459       std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
 460                                    std::ios::binary;
 461       std::ofstream file(I->getPath().c_str(), io_mode);
 462
 463       // Get the data and its length
 464       const char* data = reinterpret_cast<const char*>(I->getData());
 465       unsigned len = I->getSize();
 466
 467       // Write the data.
 468       file.write(data,len);
 469       file.close();
 470
 471       // If we're supposed to retain the original modification times, etc. do so
 472       // now.
 473       if (OriginalDates)
 474         I->getPath().setStatusInfoOnDisk(I->getFileStatus());
 475     }
 476   }
 477   return false;
 478 }
 479
 480 // doDelete - Implement the delete operation. This function deletes zero or more
 481 // members from the archive. Note that if the count is specified, there should
 482 // be no more than one path in the Paths list or else this algorithm breaks.
 483 // That check is enforced in parseCommandLine (above).
 484 bool
 485 doDelete(std::string* ErrMsg) {
 486   if (buildPaths(false, ErrMsg))
 487     return true;
 488   if (Paths.empty())
 489     return false;
 490   unsigned countDown = Count;
 491   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 492        I != E; ) {
 493     if (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end()) {
 494       if (countDown == 1) {
 495         Archive::iterator J = I;
 496         ++I;
 497         TheArchive->erase(J);
 498       } else
 499         countDown--;
 500     } else {
 501       ++I;
 502     }
 503   }
 504
 505   // We're done editting, reconstruct the archive.
 506   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 507     return true;
 508   if (ReallyVerbose)
 509     printSymbolTable();
 510   return false;
 511 }
 512
 513 // doMore - Implement the move operation. This function re-arranges just the
 514 // order of the archive members so that when the archive is written the move
 515 // of the members is accomplished. Note the use of the RelPos variable to
 516 // determine where the items should be moved to.
 517 bool
 518 doMove(std::string* ErrMsg) {
 519   if (buildPaths(false, ErrMsg))
 520     return true;
 521
 522   // By default and convention the place to move members to is the end of the
 523   // archive.
 524   Archive::iterator moveto_spot = TheArchive->end();
 525
 526   // However, if the relative positioning modifiers were used, we need to scan
 527   // the archive to find the member in question. If we don't find it, its no
 528   // crime, we just move to the end.
 529   if (AddBefore || InsertBefore || AddAfter) {
 530     for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
 531          I != E; ++I ) {
 532       if (RelPos == I->getPath().str()) {
 533         if (AddAfter) {
 534           moveto_spot = I;
 535           moveto_spot++;
 536         } else {
 537           moveto_spot = I;
 538         }
 539         break;
 540       }
 541     }
 542   }
 543
 544   // Keep a list of the paths remaining to be moved
 545   std::set<sys::Path> remaining(Paths);
 546
 547   // Scan the archive again, this time looking for the members to move to the
 548   // moveto_spot.
 549   for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
 550        I != E && !remaining.empty(); ++I ) {
 551     std::set<sys::Path>::iterator found =
 552       std::find(remaining.begin(),remaining.end(),I->getPath());
 553     if (found != remaining.end()) {
 554       if (I != moveto_spot)
 555         TheArchive->splice(moveto_spot,*TheArchive,I);
 556       remaining.erase(found);
 557     }
 558   }
 559
 560   // We're done editting, reconstruct the archive.
 561   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 562     return true;
 563   if (ReallyVerbose)
 564     printSymbolTable();
 565   return false;
 566 }
 567
 568 // doQuickAppend - Implements the 'q' operation. This function just
 569 // indiscriminantly adds the members to the archive and rebuilds it.
 570 bool
 571 doQuickAppend(std::string* ErrMsg) {
 572   // Get the list of paths to append.
 573   if (buildPaths(true, ErrMsg))
 574     return true;
 575   if (Paths.empty())
 576     return false;
 577
 578   // Append them quickly.
 579   for (std::set<sys::Path>::iterator PI = Paths.begin(), PE = Paths.end();
 580        PI != PE; ++PI) {
 581     if (TheArchive->addFileBefore(*PI,TheArchive->end(),ErrMsg))
 582       return true;
 583   }
 584
 585   // We're done editting, reconstruct the archive.
 586   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 587     return true;
 588   if (ReallyVerbose)
 589     printSymbolTable();
 590   return false;
 591 }
 592
 593 // doReplaceOrInsert - Implements the 'r' operation. This function will replace
 594 // any existing files or insert new ones into the archive.
 595 bool
 596 doReplaceOrInsert(std::string* ErrMsg) {
 597
 598   // Build the list of files to be added/replaced.
 599   if (buildPaths(true, ErrMsg))
 600     return true;
 601   if (Paths.empty())
 602     return false;
 603
 604   // Keep track of the paths that remain to be inserted.
 605   std::set<sys::Path> remaining(Paths);
 606
 607   // Default the insertion spot to the end of the archive
 608   Archive::iterator insert_spot = TheArchive->end();
 609
 610   // Iterate over the archive contents
 611   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 612        I != E && !remaining.empty(); ++I ) {
 613
 614     // Determine if this archive member matches one of the paths we're trying
 615     // to replace.
 616
 617     std::set<sys::Path>::iterator found = remaining.end();
 618     for (std::set<sys::Path>::iterator RI = remaining.begin(),
 619          RE = remaining.end(); RI != RE; ++RI ) {
 620       std::string compare(RI->str());
 621       if (TruncateNames && compare.length() > 15) {
 622         const char* nm = compare.c_str();
 623         unsigned len = compare.length();
 624         size_t slashpos = compare.rfind('/');
 625         if (slashpos != std::string::npos) {
 626           nm += slashpos + 1;
 627           len -= slashpos +1;
 628         }
 629         if (len > 15)
 630           len = 15;
 631         compare.assign(nm,len);
 632       }
 633       if (compare == I->getPath().str()) {
 634         found = RI;
 635         break;
 636       }
 637     }
 638
 639     if (found != remaining.end()) {
 640       std::string Err;
 641       sys::PathWithStatus PwS(*found);
 642       const sys::FileStatus *si = PwS.getFileStatus(false, &Err);
 643       if (!si)
 644         return true;
 645       if (!si->isDir) {
 646         if (OnlyUpdate) {
 647           // Replace the item only if it is newer.
 648           if (si->modTime > I->getModTime())
 649             if (I->replaceWith(*found, ErrMsg))
 650               return true;
 651         } else {
 652           // Replace the item regardless of time stamp
 653           if (I->replaceWith(*found, ErrMsg))
 654             return true;
 655         }
 656       } else {
 657         // We purposefully ignore directories.
 658       }
 659
 660       // Remove it from our "to do" list
 661       remaining.erase(found);
 662     }
 663
 664     // Determine if this is the place where we should insert
 665     if ((AddBefore || InsertBefore) && RelPos == I->getPath().str())
 666       insert_spot = I;
 667     else if (AddAfter && RelPos == I->getPath().str()) {
 668       insert_spot = I;
 669       insert_spot++;
 670     }
 671   }
 672
 673   // If we didn't replace all the members, some will remain and need to be
 674   // inserted at the previously computed insert-spot.
 675   if (!remaining.empty()) {
 676     for (std::set<sys::Path>::iterator PI = remaining.begin(),
 677          PE = remaining.end(); PI != PE; ++PI) {
 678       if (TheArchive->addFileBefore(*PI,insert_spot, ErrMsg))
 679         return true;
 680     }
 681   }
 682
 683   // We're done editting, reconstruct the archive.
 684   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 685     return true;
 686   if (ReallyVerbose)
 687     printSymbolTable();
 688   return false;
 689 }
 690
 691 // main - main program for llvm-ar .. see comments in the code
 692 int main(int argc, char **argv) {
 693   // Print a stack trace if we signal out.
 694   sys::PrintStackTraceOnErrorSignal();
 695   PrettyStackTraceProgram X(argc, argv);
 696   LLVMContext &Context = getGlobalContext();
 697   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 698
 699   // Have the command line options parsed and handle things
 700   // like --help and --version.
 701   cl::ParseCommandLineOptions(argc, argv,
 702     "LLVM Archiver (llvm-ar)\n\n"
 703     "  This program archives bitcode files into single libraries\n"
 704   );
 705
 706   int exitCode = 0;
 707
 708   // Make sure we don't exit with "unhandled exception".
 709   try {
 710     // Do our own parsing of the command line because the CommandLine utility
 711     // can't handle the grouped positional parameters without a dash.
 712     ArchiveOperation Operation = parseCommandLine();
 713
 714     // Check the path name of the archive
 715     sys::Path ArchivePath;
 716     if (!ArchivePath.set(ArchiveName))
 717       throw std::string("Archive name invalid: ") + ArchiveName;
 718
 719     // Create or open the archive object.
 720     bool Exists;
 721     if (llvm::sys::fs::exists(ArchivePath.str(), Exists) || !Exists) {
 722       // Produce a warning if we should and we're creating the archive
 723       if (!Create)
 724         errs() << argv[0] << ": creating " << ArchivePath.str() << "\n";
 725       TheArchive = Archive::CreateEmpty(ArchivePath, Context);
 726       TheArchive->writeToDisk();
 727     } else {
 728       std::string Error;
 729       TheArchive = Archive::OpenAndLoad(ArchivePath, Context, &Error);
 730       if (TheArchive == 0) {
 731         errs() << argv[0] << ": error loading '" << ArchivePath.str() << "': "
 732                << Error << "!\n";
 733         return 1;
 734       }
 735     }
 736
 737     // Make sure we're not fooling ourselves.
 738     assert(TheArchive && "Unable to instantiate the archive");
 739
 740     // Make sure we clean up the archive even on failure.
 741     std::auto_ptr<Archive> AutoArchive(TheArchive);
 742
 743     // Perform the operation
 744     std::string ErrMsg;
 745     bool haveError = false;
 746     switch (Operation) {
 747       case Print:           haveError = doPrint(&ErrMsg); break;
 748       case Delete:          haveError = doDelete(&ErrMsg); break;
 749       case Move:            haveError = doMove(&ErrMsg); break;
 750       case QuickAppend:     haveError = doQuickAppend(&ErrMsg); break;
 751       case ReplaceOrInsert: haveError = doReplaceOrInsert(&ErrMsg); break;
 752       case DisplayTable:    haveError = doDisplayTable(&ErrMsg); break;
 753       case Extract:         haveError = doExtract(&ErrMsg); break;
 754       case NoOperation:
 755         errs() << argv[0] << ": No operation was selected.\n";
 756         break;
 757     }
 758     if (haveError) {
 759       errs() << argv[0] << ": " << ErrMsg << "\n";
 760       return 1;
 761     }
 762   } catch (const char*msg) {
 763     // These errors are usage errors, thrown only by the various checks in the
 764     // code above.
 765     errs() << argv[0] << ": " << msg << "\n\n";
 766     cl::PrintHelpMessage();
 767     exitCode = 1;
 768   } catch (const std::string& msg) {
 769     // These errors are thrown by LLVM libraries (e.g. lib System) and represent
 770     // a more serious error so we bump the exitCode and don't print the usage.
 771     errs() << argv[0] << ": " << msg << "\n";
 772     exitCode = 2;
 773   } catch (...) {
 774     // This really shouldn't happen, but just in case ....
 775     errs() << argv[0] << ": An unexpected unknown exception occurred.\n";
 776     exitCode = 3;
 777   }
 778
 779   // Return result code back to operating system.
 780   return exitCode;
 781 }