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/ManagedStatic.h"
  20 #include "llvm/Support/PrettyStackTrace.h"
  21 #include "llvm/Support/raw_ostream.h"
  22 #include "llvm/System/Signals.h"
  23 #include <iostream>
  24 #include <algorithm>
  25 #include <iomanip>
  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       if (!aPath.exists())
 315         throw std::string("File does not exist: ") + Members[i];
 316       std::string Err;
 317       sys::PathWithStatus PwS(aPath);
 318       const sys::FileStatus *si = PwS.getFileStatus(false, &Err);
 319       if (!si)
 320         throw Err;
 321       if (si->isDir) {
 322         std::set<sys::Path> dirpaths;
 323         if (recurseDirectories(aPath, dirpaths, ErrMsg))
 324           return true;
 325         Paths.insert(dirpaths.begin(),dirpaths.end());
 326       } else {
 327         Paths.insert(aPath);
 328       }
 329     } else {
 330       Paths.insert(aPath);
 331     }
 332   }
 333   return false;
 334 }
 335
 336 // printSymbolTable - print out the archive's symbol table.
 337 void printSymbolTable() {
 338   std::cout << "\nArchive Symbol Table:\n";
 339   const Archive::SymTabType& symtab = TheArchive->getSymbolTable();
 340   for (Archive::SymTabType::const_iterator I=symtab.begin(), E=symtab.end();
 341        I != E; ++I ) {
 342     unsigned offset = TheArchive->getFirstFileOffset() + I->second;
 343     std::cout << " " << std::setw(9) << offset << "\t" << I->first <<"\n";
 344   }
 345 }
 346
 347 // doPrint - Implements the 'p' operation. This function traverses the archive
 348 // looking for members that match the path list. It is careful to uncompress
 349 // things that should be and to skip bitcode files unless the 'k' modifier was
 350 // given.
 351 bool doPrint(std::string* ErrMsg) {
 352   if (buildPaths(false, ErrMsg))
 353     return true;
 354   unsigned countDown = Count;
 355   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 356        I != E; ++I ) {
 357     if (Paths.empty() ||
 358         (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
 359       if (countDown == 1) {
 360         const char* data = reinterpret_cast<const char*>(I->getData());
 361
 362         // Skip things that don't make sense to print
 363         if (I->isLLVMSymbolTable() || I->isSVR4SymbolTable() ||
 364             I->isBSD4SymbolTable() || (!DontSkipBitcode && I->isBitcode()))
 365           continue;
 366
 367         if (Verbose)
 368           std::cout << "Printing " << I->getPath().str() << "\n";
 369
 370         unsigned len = I->getSize();
 371         std::cout.write(data, len);
 372       } else {
 373         countDown--;
 374       }
 375     }
 376   }
 377   return false;
 378 }
 379
 380 // putMode - utility function for printing out the file mode when the 't'
 381 // operation is in verbose mode.
 382 void
 383 printMode(unsigned mode) {
 384   if (mode & 004)
 385     std::cout << "r";
 386   else
 387     std::cout << "-";
 388   if (mode & 002)
 389     std::cout << "w";
 390   else
 391     std::cout << "-";
 392   if (mode & 001)
 393     std::cout << "x";
 394   else
 395     std::cout << "-";
 396 }
 397
 398 // doDisplayTable - Implement the 't' operation. This function prints out just
 399 // the file names of each of the members. However, if verbose mode is requested
 400 // ('v' modifier) then the file type, permission mode, user, group, size, and
 401 // modification time are also printed.
 402 bool
 403 doDisplayTable(std::string* ErrMsg) {
 404   if (buildPaths(false, ErrMsg))
 405     return true;
 406   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 407        I != E; ++I ) {
 408     if (Paths.empty() ||
 409         (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
 410       if (Verbose) {
 411         // FIXME: Output should be this format:
 412         // Zrw-r--r--  500/ 500    525 Nov  8 17:42 2004 Makefile
 413         if (I->isBitcode())
 414           std::cout << "b";
 415         else if (I->isCompressed())
 416           std::cout << "Z";
 417         else
 418           std::cout << " ";
 419         unsigned mode = I->getMode();
 420         printMode((mode >> 6) & 007);
 421         printMode((mode >> 3) & 007);
 422         printMode(mode & 007);
 423         std::cout << " " << std::setw(4) << I->getUser();
 424         std::cout << "/" << std::setw(4) << I->getGroup();
 425         std::cout << " " << std::setw(8) << I->getSize();
 426         std::cout << " " << std::setw(20) << I->getModTime().str().substr(4);
 427         std::cout << " " << I->getPath().str() << "\n";
 428       } else {
 429         std::cout << I->getPath().str() << "\n";
 430       }
 431     }
 432   }
 433   if (ReallyVerbose)
 434     printSymbolTable();
 435   return false;
 436 }
 437
 438 // doExtract - Implement the 'x' operation. This function extracts files back to
 439 // the file system, making sure to uncompress any that were compressed
 440 bool
 441 doExtract(std::string* ErrMsg) {
 442   if (buildPaths(false, ErrMsg))
 443     return true;
 444   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 445        I != E; ++I ) {
 446     if (Paths.empty() ||
 447         (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
 448
 449       // Make sure the intervening directories are created
 450       if (I->hasPath()) {
 451         sys::Path dirs(I->getPath());
 452         dirs.eraseComponent();
 453         if (dirs.createDirectoryOnDisk(/*create_parents=*/true, ErrMsg))
 454           return true;
 455       }
 456
 457       // Open up a file stream for writing
 458       std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
 459                                    std::ios::binary;
 460       std::ofstream file(I->getPath().c_str(), io_mode);
 461
 462       // Get the data and its length
 463       const char* data = reinterpret_cast<const char*>(I->getData());
 464       unsigned len = I->getSize();
 465
 466       // Write the data.
 467       file.write(data,len);
 468       file.close();
 469
 470       // If we're supposed to retain the original modification times, etc. do so
 471       // now.
 472       if (OriginalDates)
 473         I->getPath().setStatusInfoOnDisk(I->getFileStatus());
 474     }
 475   }
 476   return false;
 477 }
 478
 479 // doDelete - Implement the delete operation. This function deletes zero or more
 480 // members from the archive. Note that if the count is specified, there should
 481 // be no more than one path in the Paths list or else this algorithm breaks.
 482 // That check is enforced in parseCommandLine (above).
 483 bool
 484 doDelete(std::string* ErrMsg) {
 485   if (buildPaths(false, ErrMsg))
 486     return true;
 487   if (Paths.empty())
 488     return false;
 489   unsigned countDown = Count;
 490   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 491        I != E; ) {
 492     if (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end()) {
 493       if (countDown == 1) {
 494         Archive::iterator J = I;
 495         ++I;
 496         TheArchive->erase(J);
 497       } else
 498         countDown--;
 499     } else {
 500       ++I;
 501     }
 502   }
 503
 504   // We're done editting, reconstruct the archive.
 505   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 506     return true;
 507   if (ReallyVerbose)
 508     printSymbolTable();
 509   return false;
 510 }
 511
 512 // doMore - Implement the move operation. This function re-arranges just the
 513 // order of the archive members so that when the archive is written the move
 514 // of the members is accomplished. Note the use of the RelPos variable to
 515 // determine where the items should be moved to.
 516 bool
 517 doMove(std::string* ErrMsg) {
 518   if (buildPaths(false, ErrMsg))
 519     return true;
 520
 521   // By default and convention the place to move members to is the end of the
 522   // archive.
 523   Archive::iterator moveto_spot = TheArchive->end();
 524
 525   // However, if the relative positioning modifiers were used, we need to scan
 526   // the archive to find the member in question. If we don't find it, its no
 527   // crime, we just move to the end.
 528   if (AddBefore || InsertBefore || AddAfter) {
 529     for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
 530          I != E; ++I ) {
 531       if (RelPos == I->getPath().str()) {
 532         if (AddAfter) {
 533           moveto_spot = I;
 534           moveto_spot++;
 535         } else {
 536           moveto_spot = I;
 537         }
 538         break;
 539       }
 540     }
 541   }
 542
 543   // Keep a list of the paths remaining to be moved
 544   std::set<sys::Path> remaining(Paths);
 545
 546   // Scan the archive again, this time looking for the members to move to the
 547   // moveto_spot.
 548   for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
 549        I != E && !remaining.empty(); ++I ) {
 550     std::set<sys::Path>::iterator found =
 551       std::find(remaining.begin(),remaining.end(),I->getPath());
 552     if (found != remaining.end()) {
 553       if (I != moveto_spot)
 554         TheArchive->splice(moveto_spot,*TheArchive,I);
 555       remaining.erase(found);
 556     }
 557   }
 558
 559   // We're done editting, reconstruct the archive.
 560   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 561     return true;
 562   if (ReallyVerbose)
 563     printSymbolTable();
 564   return false;
 565 }
 566
 567 // doQuickAppend - Implements the 'q' operation. This function just
 568 // indiscriminantly adds the members to the archive and rebuilds it.
 569 bool
 570 doQuickAppend(std::string* ErrMsg) {
 571   // Get the list of paths to append.
 572   if (buildPaths(true, ErrMsg))
 573     return true;
 574   if (Paths.empty())
 575     return false;
 576
 577   // Append them quickly.
 578   for (std::set<sys::Path>::iterator PI = Paths.begin(), PE = Paths.end();
 579        PI != PE; ++PI) {
 580     if (TheArchive->addFileBefore(*PI,TheArchive->end(),ErrMsg))
 581       return true;
 582   }
 583
 584   // We're done editting, reconstruct the archive.
 585   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 586     return true;
 587   if (ReallyVerbose)
 588     printSymbolTable();
 589   return false;
 590 }
 591
 592 // doReplaceOrInsert - Implements the 'r' operation. This function will replace
 593 // any existing files or insert new ones into the archive.
 594 bool
 595 doReplaceOrInsert(std::string* ErrMsg) {
 596
 597   // Build the list of files to be added/replaced.
 598   if (buildPaths(true, ErrMsg))
 599     return true;
 600   if (Paths.empty())
 601     return false;
 602
 603   // Keep track of the paths that remain to be inserted.
 604   std::set<sys::Path> remaining(Paths);
 605
 606   // Default the insertion spot to the end of the archive
 607   Archive::iterator insert_spot = TheArchive->end();
 608
 609   // Iterate over the archive contents
 610   for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
 611        I != E && !remaining.empty(); ++I ) {
 612
 613     // Determine if this archive member matches one of the paths we're trying
 614     // to replace.
 615
 616     std::set<sys::Path>::iterator found = remaining.end();
 617     for (std::set<sys::Path>::iterator RI = remaining.begin(),
 618          RE = remaining.end(); RI != RE; ++RI ) {
 619       std::string compare(RI->str());
 620       if (TruncateNames && compare.length() > 15) {
 621         const char* nm = compare.c_str();
 622         unsigned len = compare.length();
 623         size_t slashpos = compare.rfind('/');
 624         if (slashpos != std::string::npos) {
 625           nm += slashpos + 1;
 626           len -= slashpos +1;
 627         }
 628         if (len > 15)
 629           len = 15;
 630         compare.assign(nm,len);
 631       }
 632       if (compare == I->getPath().str()) {
 633         found = RI;
 634         break;
 635       }
 636     }
 637
 638     if (found != remaining.end()) {
 639       std::string Err;
 640       sys::PathWithStatus PwS(*found);
 641       const sys::FileStatus *si = PwS.getFileStatus(false, &Err);
 642       if (!si)
 643         return true;
 644       if (!si->isDir) {
 645         if (OnlyUpdate) {
 646           // Replace the item only if it is newer.
 647           if (si->modTime > I->getModTime())
 648             if (I->replaceWith(*found, ErrMsg))
 649               return true;
 650         } else {
 651           // Replace the item regardless of time stamp
 652           if (I->replaceWith(*found, ErrMsg))
 653             return true;
 654         }
 655       } else {
 656         // We purposefully ignore directories.
 657       }
 658
 659       // Remove it from our "to do" list
 660       remaining.erase(found);
 661     }
 662
 663     // Determine if this is the place where we should insert
 664     if ((AddBefore || InsertBefore) && RelPos == I->getPath().str())
 665       insert_spot = I;
 666     else if (AddAfter && RelPos == I->getPath().str()) {
 667       insert_spot = I;
 668       insert_spot++;
 669     }
 670   }
 671
 672   // If we didn't replace all the members, some will remain and need to be
 673   // inserted at the previously computed insert-spot.
 674   if (!remaining.empty()) {
 675     for (std::set<sys::Path>::iterator PI = remaining.begin(),
 676          PE = remaining.end(); PI != PE; ++PI) {
 677       if (TheArchive->addFileBefore(*PI,insert_spot, ErrMsg))
 678         return true;
 679     }
 680   }
 681
 682   // We're done editting, reconstruct the archive.
 683   if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
 684     return true;
 685   if (ReallyVerbose)
 686     printSymbolTable();
 687   return false;
 688 }
 689
 690 // main - main program for llvm-ar .. see comments in the code
 691 int main(int argc, char **argv) {
 692   // Print a stack trace if we signal out.
 693   sys::PrintStackTraceOnErrorSignal();
 694   PrettyStackTraceProgram X(argc, argv);
 695   LLVMContext &Context = getGlobalContext();
 696   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 697
 698   // Have the command line options parsed and handle things
 699   // like --help and --version.
 700   cl::ParseCommandLineOptions(argc, argv,
 701     "LLVM Archiver (llvm-ar)\n\n"
 702     "  This program archives bitcode files into single libraries\n"
 703   );
 704
 705   int exitCode = 0;
 706
 707   // Make sure we don't exit with "unhandled exception".
 708   try {
 709     // Do our own parsing of the command line because the CommandLine utility
 710     // can't handle the grouped positional parameters without a dash.
 711     ArchiveOperation Operation = parseCommandLine();
 712
 713     // Check the path name of the archive
 714     sys::Path ArchivePath;
 715     if (!ArchivePath.set(ArchiveName))
 716       throw std::string("Archive name invalid: ") + ArchiveName;
 717
 718     // Create or open the archive object.
 719     if (!ArchivePath.exists()) {
 720       // Produce a warning if we should and we're creating the archive
 721       if (!Create)
 722         errs() << argv[0] << ": creating " << ArchivePath.str() << "\n";
 723       TheArchive = Archive::CreateEmpty(ArchivePath, Context);
 724       TheArchive->writeToDisk();
 725     } else {
 726       std::string Error;
 727       TheArchive = Archive::OpenAndLoad(ArchivePath, Context, &Error);
 728       if (TheArchive == 0) {
 729         errs() << argv[0] << ": error loading '" << ArchivePath.str() << "': "
 730                << Error << "!\n";
 731         return 1;
 732       }
 733     }
 734
 735     // Make sure we're not fooling ourselves.
 736     assert(TheArchive && "Unable to instantiate the archive");
 737
 738     // Make sure we clean up the archive even on failure.
 739     std::auto_ptr<Archive> AutoArchive(TheArchive);
 740
 741     // Perform the operation
 742     std::string ErrMsg;
 743     bool haveError = false;
 744     switch (Operation) {
 745       case Print:           haveError = doPrint(&ErrMsg); break;
 746       case Delete:          haveError = doDelete(&ErrMsg); break;
 747       case Move:            haveError = doMove(&ErrMsg); break;
 748       case QuickAppend:     haveError = doQuickAppend(&ErrMsg); break;
 749       case ReplaceOrInsert: haveError = doReplaceOrInsert(&ErrMsg); break;
 750       case DisplayTable:    haveError = doDisplayTable(&ErrMsg); break;
 751       case Extract:         haveError = doExtract(&ErrMsg); break;
 752       case NoOperation:
 753         errs() << argv[0] << ": No operation was selected.\n";
 754         break;
 755     }
 756     if (haveError) {
 757       errs() << argv[0] << ": " << ErrMsg << "\n";
 758       return 1;
 759     }
 760   } catch (const char*msg) {
 761     // These errors are usage errors, thrown only by the various checks in the
 762     // code above.
 763     errs() << argv[0] << ": " << msg << "\n\n";
 764     cl::PrintHelpMessage();
 765     exitCode = 1;
 766   } catch (const std::string& msg) {
 767     // These errors are thrown by LLVM libraries (e.g. lib System) and represent
 768     // a more serious error so we bump the exitCode and don't print the usage.
 769     errs() << argv[0] << ": " << msg << "\n";
 770     exitCode = 2;
 771   } catch (...) {
 772     // This really shouldn't happen, but just in case ....
 773     errs() << argv[0] << ": An unexpected unknown exception occurred.\n";
 774     exitCode = 3;
 775   }
 776
 777   // Return result code back to operating system.
 778   return exitCode;
 779 }