X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=tools%2Fllvm-ar%2Fllvm-ar.cpp;h=fd6841c9f16de57b8555329bcde3437fe4283fcb;hb=55ec2218c448ef9e0d09b5534885b6d2a9786a73;hp=4b79cd367d8fa027b3aaf8720671f53e7fa9c7ca;hpb=9de7b334ec6f80a15f093f11b339f5741c964b34;p=oota-llvm.git

diff --git a/tools/llvm-ar/llvm-ar.cpp b/tools/llvm-ar/llvm-ar.cpp
index 4b79cd367d8..fd6841c9f16 100644
--- a/tools/llvm-ar/llvm-ar.cpp
+++ b/tools/llvm-ar/llvm-ar.cpp
@@ -1,560 +1,664 @@
 //===-- llvm-ar.cpp - LLVM archive librarian utility ----------------------===//
-// 
+//
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
 //===----------------------------------------------------------------------===//
 //
-// Builds up standard unix archive files (.a) containing LLVM bytecode.
+// Builds up (relatively) standard unix archive files (.a) containing LLVM
+// bitcode or other files.
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Module.h"
-#include "llvm/Bytecode/Reader.h"
-#include "Support/CommandLine.h"
-#include "Support/FileUtilities.h"
-#include "llvm/System/Signals.h"
-#include <string>
-#include <fstream>
-#include <iostream>
-#include <cstdio>
-#include <sys/stat.h>
-#include <sys/types.h> 
+#include "Archive.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cstdlib>
 #include <fcntl.h>
-#include <unistd.h>
-#include <sys/mman.h>
-using namespace llvm;
+#include <memory>
 
-using std::string;
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
+#include <unistd.h>
+#else
+#include <io.h>
+#endif
 
+using namespace llvm;
 
-#define  ARFMAG    "\n"      /* header trailer string */ 
-#define  ARMAG   "!<arch>\n"  /* magic string */ 
-#define  SARMAG  8            /* length of magic string */ 
-#define VERSION "llvm-ar is a part of the LLVM compiler infrastructure.\nPlease see http://llvm.cs.uiuc.edu for more information.\n";
+// Option for compatibility with AIX, not used but must allow it to be present.
+static cl::opt<bool>
+X32Option ("X32_64", cl::Hidden,
+            cl::desc("Ignored option for compatibility with AIX"));
+
+// llvm-ar operation code and modifier flags. This must come first.
+static cl::opt<std::string>
+Options(cl::Positional, cl::Required, cl::desc("{operation}[modifiers]..."));
+
+// llvm-ar remaining positional arguments.
+static cl::list<std::string>
+RestOfArgs(cl::Positional, cl::OneOrMore,
+    cl::desc("[relpos] [count] <archive-file> [members]..."));
+
+// MoreHelp - Provide additional help output explaining the operations and
+// modifiers of llvm-ar. This object instructs the CommandLine library
+// to print the text of the constructor when the --help option is given.
+static cl::extrahelp MoreHelp(
+  "\nOPERATIONS:\n"
+  "  d[NsS]       - delete file(s) from the archive\n"
+  "  m[abiSs]     - move file(s) in the archive\n"
+  "  p[kN]        - print file(s) found in the archive\n"
+  "  q[ufsS]      - quick append file(s) to the archive\n"
+  "  r[abfiuRsS]  - replace or insert file(s) into the archive\n"
+  "  t            - display contents of archive\n"
+  "  x[No]        - extract file(s) from the archive\n"
+  "\nMODIFIERS (operation specific):\n"
+  "  [a] - put file(s) after [relpos]\n"
+  "  [b] - put file(s) before [relpos] (same as [i])\n"
+  "  [i] - put file(s) before [relpos] (same as [b])\n"
+  "  [N] - use instance [count] of name\n"
+  "  [o] - preserve original dates\n"
+  "  [s] - create an archive index (cf. ranlib)\n"
+  "  [S] - do not build a symbol table\n"
+  "  [u] - update only files newer than archive contents\n"
+  "\nMODIFIERS (generic):\n"
+  "  [c] - do not warn if the library had to be created\n"
+  "  [v] - be verbose about actions taken\n"
+);
+
+// This enumeration delineates the kinds of operations on an archive
+// that are permitted.
+enum ArchiveOperation {
+  Print,            ///< Print the contents of the archive
+  Delete,           ///< Delete the specified members
+  Move,             ///< Move members to end or as given by {a,b,i} modifiers
+  QuickAppend,      ///< Quickly append to end of archive
+  ReplaceOrInsert,  ///< Replace or Insert members
+  DisplayTable,     ///< Display the table of contents
+  Extract           ///< Extract files back to file system
+};
 
+// Modifiers to follow operation to vary behavior
+bool AddAfter = false;           ///< 'a' modifier
+bool AddBefore = false;          ///< 'b' modifier
+bool Create = false;             ///< 'c' modifier
+bool OriginalDates = false;      ///< 'o' modifier
+bool SymTable = true;            ///< 's' & 'S' modifiers
+bool OnlyUpdate = false;         ///< 'u' modifier
+bool Verbose = false;            ///< 'v' modifier
+
+// Relative Positional Argument (for insert/move). This variable holds
+// the name of the archive member to which the 'a', 'b' or 'i' modifier
+// refers. Only one of 'a', 'b' or 'i' can be specified so we only need
+// one variable.
+std::string RelPos;
+
+// This variable holds the name of the archive file as given on the
+// command line.
+std::string ArchiveName;
+
+// This variable holds the list of member files to proecess, as given
+// on the command line.
+std::vector<std::string> Members;
+
+// This variable holds the (possibly expanded) list of path objects that
+// correspond to files we will
+std::set<std::string> Paths;
+
+// The Archive object to which all the editing operations will be sent.
+Archive* TheArchive = 0;
+
+// The name this program was invoked as.
+static const char *program_name;
+
+// show_help - Show the error message, the help message and exit.
+LLVM_ATTRIBUTE_NORETURN static void
+show_help(const std::string &msg) {
+  errs() << program_name << ": " << msg << "\n\n";
+  cl::PrintHelpMessage();
+  if (TheArchive)
+    delete TheArchive;
+  std::exit(1);
+}
 
-// Each file member is preceded by a file member header. Which is
-// of the following format:
-//
-// char ar_name[16]  - '/' terminated file member name. 
-//                     If the file name does not fit, a dummy name is used.
-// char ar_date[12]  - file date in decimal
-// char ar_uid[6]    - User id of file owner in decimal.
-// char ar_gid[6]    - Group ID file belongs to in decimal.
-// char ar_mode[8]   - File mode in octal.
-// char ar_size[10]  - Size of file in decimal.
-// char ar_fmag[2]   - Trailer of header file, a newline.
-struct ar_hdr {
-  char name[16];
-  char date[12];
-  char uid[6];
-  char gid[6];
-  char mode[8];
-  char size[10];
-  char fmag[2]; 
-  void init() {
-    memset(name,' ',16);
-    memset(date,' ',12);
-    memset(uid,' ',6);
-    memset(gid,' ',6);
-    memset(mode,' ',8);
-    memset(size,' ',10);
-    memset(fmag,' ',2);
-    }
-};
+// fail - Show the error message and exit.
+LLVM_ATTRIBUTE_NORETURN static void
+fail(const std::string &msg) {
+  errs() << program_name << ": " << msg << "\n\n";
+  if (TheArchive)
+    delete TheArchive;
+  std::exit(1);
+}
 
+// getRelPos - Extract the member filename from the command line for
+// the [relpos] argument associated with a, b, and i modifiers
+void getRelPos() {
+  if(RestOfArgs.size() == 0)
+    show_help("Expected [relpos] for a, b, or i modifier");
+  RelPos = RestOfArgs[0];
+  RestOfArgs.erase(RestOfArgs.begin());
+}
 
-//Option for X32_64, not used but must allow it to be present.
-cl::opt<bool> X32Option ("X32_64", cl::desc("Ignored option spelt -X32_64, for compatibility with AIX"), cl::Optional);
+// getArchive - Get the archive file name from the command line
+void getArchive() {
+  if(RestOfArgs.size() == 0)
+    show_help("An archive name must be specified");
+  ArchiveName = RestOfArgs[0];
+  RestOfArgs.erase(RestOfArgs.begin());
+}
 
-//llvm-ar options
-cl::opt<string> Options(cl::Positional, cl::desc("{dmpqrstx}[abcfilNoPsSuvV] "), cl::Required);
+// getMembers - Copy over remaining items in RestOfArgs to our Members vector
+// This is just for clarity.
+void getMembers() {
+  if(RestOfArgs.size() > 0)
+    Members = std::vector<std::string>(RestOfArgs);
+}
 
-//llvm-ar options
-cl::list<string> RestofArgs(cl::Positional, cl::desc("[relpos] [count]] <archive-file> [members..]"), cl::Optional);
+// parseCommandLine - Parse the command line options as presented and return the
+// operation specified. Process all modifiers and check to make sure that
+// constraints on modifier/operation pairs have not been violated.
+ArchiveOperation parseCommandLine() {
 
-//booleans to represent Operation, only one can be preformed at a time
-bool Print, Delete, Move, QuickAppend, InsertWithReplacement, DisplayTable;
-bool Extract;
+  // Keep track of number of operations. We can only specify one
+  // per execution.
+  unsigned NumOperations = 0;
 
-//Modifiers to follow operation to vary behavior
-bool AddAfter, AddBefore, Create, TruncateNames, InsertBefore, UseCount;
-bool OriginalDates,  FullPath, SymTable, OnlyUpdate, Verbose;
+  // Keep track of the number of positional modifiers (a,b,i). Only
+  // one can be specified.
+  unsigned NumPositional = 0;
 
-//Realtive Pos Arg
-string RelPos;
+  // Keep track of which operation was requested
+  ArchiveOperation Operation;
 
-//Count, use for multiple entries in the archive with the same name
-int Count;
+  for(unsigned i=0; i<Options.size(); ++i) {
+    switch(Options[i]) {
+    case 'd': ++NumOperations; Operation = Delete; break;
+    case 'm': ++NumOperations; Operation = Move ; break;
+    case 'p': ++NumOperations; Operation = Print; break;
+    case 'q': ++NumOperations; Operation = QuickAppend; break;
+    case 'r': ++NumOperations; Operation = ReplaceOrInsert; break;
+    case 't': ++NumOperations; Operation = DisplayTable; break;
+    case 'x': ++NumOperations; Operation = Extract; break;
+    case 'c': Create = true; break;
+    case 'l': /* accepted but unused */ break;
+    case 'o': OriginalDates = true; break;
+    case 's': break; // Ignore for now.
+    case 'S': break; // Ignore for now.
+    case 'u': OnlyUpdate = true; break;
+    case 'v': Verbose = true; break;
+    case 'a':
+      getRelPos();
+      AddAfter = true;
+      NumPositional++;
+      break;
+    case 'b':
+      getRelPos();
+      AddBefore = true;
+      NumPositional++;
+      break;
+    case 'i':
+      getRelPos();
+      AddBefore = true;
+      NumPositional++;
+      break;
+    default:
+      cl::PrintHelpMessage();
+    }
+  }
 
-//Archive
-string Archive;
+  // At this point, the next thing on the command line must be
+  // the archive name.
+  getArchive();
 
-//Member Files
-std::vector<string> Members;
+  // Everything on the command line at this point is a member.
+  getMembers();
 
+  // Perform various checks on the operation/modifier specification
+  // to make sure we are dealing with a legal request.
+  if (NumOperations == 0)
+    show_help("You must specify at least one of the operations");
+  if (NumOperations > 1)
+    show_help("Only one operation may be specified");
+  if (NumPositional > 1)
+    show_help("You may only specify one of a, b, and i modifiers");
+  if (AddAfter || AddBefore) {
+    if (Operation != Move && Operation != ReplaceOrInsert)
+      show_help("The 'a', 'b' and 'i' modifiers can only be specified with "
+            "the 'm' or 'r' operations");
+  }
+  if (OriginalDates && Operation != Extract)
+    show_help("The 'o' modifier is only applicable to the 'x' operation");
+  if (OnlyUpdate && Operation != ReplaceOrInsert)
+    show_help("The 'u' modifier is only applicable to the 'r' operation");
 
-// WriteSymbolTable - Writes symbol table to ArchiveFile, return false
-// on errors. Also returns by reference size of symbol table.
-//
-// Overview of method:
-// 1) Generate the header for the symbol table. This is a normal
-//    archive member header, but it has a zero length name.
-// 2) For each archive member file, stat the file and parse the bytecode
-//    Store cumulative offset (file size + header size).
-// 3) Loop over all the symbols for the current member file, 
-//    add offset entry to offset vector, and add symbol name to its vector.
-//    Note: The symbol name vector is a vector of chars to speed up calculating
-//    the total size of the symbol table.
-// 4) Update offset vector once we know the total size of symbol table. This is
-//    because the symbol table appears before all archive member file contents.
-//    We add the size of magic string, and size of symbol table to each offset.
-// 5) If the new updated offset it not even, we add 1 byte to offset because
-//    a newline will be inserted when writing member files. This adjustment is
-//    cummulative (ie. each time we have an odd offset we add 1 to total adjustment).
-// 6) Lastly, write symbol table to file.
-//
-bool WriteSymbolTable(std::ofstream &ArchiveFile) {
- 
-  //Create header for symbol table. This is essentially an empty header with the
-  //name set to a '/' to indicate its a symbol table.
-  ar_hdr Hdr;
-  Hdr.init();
-
-  //Name of symbol table is '/'
-  Hdr.name[0] = '/';
-  Hdr.name[1] = '\0';
-  
-  //Set the header trailer to a newline
-  memcpy(Hdr.fmag,ARFMAG,sizeof(ARFMAG));
-
-  
-  //Write header to archive file
-  ArchiveFile.write((char*)&Hdr, sizeof(Hdr));
-  
-
-  unsigned memoff = 0;  //Keep Track of total size of files added to archive
-  std::vector<unsigned> offsets; //Vector of offsets into archive file
-  std::vector<char> names; //Vector of characters that are the symbol names. 
-
-  //Loop over archive member files, parse bytecode, and generate symbol table.
-  for(unsigned i=0; i<Members.size(); ++i) { 
-    
-    //Open Member file for reading and copy to buffer
-    int FD = open(Members[i].c_str(),O_RDONLY);
-    
-    //Check for errors opening the file.
-    if (FD == -1) {
-      std::cerr << "Error opening file!\n";
-      return false;
-    }
+  // Return the parsed operation to the caller
+  return Operation;
+}
 
-    // Size of file
-    unsigned Length = getFileSize(Members[i]);
-    if (Length == (unsigned)-1) {
-      std::cerr << "Error stating file\n";
-      return false;
-    }
-    
-    //Read in file into a buffer.
-    unsigned char *buf = (unsigned char*)mmap(0, Length,PROT_READ,
-					      MAP_PRIVATE, FD, 0);
-  
-    //Check if mmap failed.
-    if (buf == (unsigned char*)MAP_FAILED) {
-      std::cerr << "Error mmapping file!\n";
-      return false;
-    }
-    
-    //Parse the bytecode file and get all the symbols.
-    string ErrorStr;
-    Module *M = ParseBytecodeBuffer(buf,Length,Members[i],&ErrorStr);
-    
-    //Check for errors parsing bytecode.
-    //if(ErrorStr) {
-    //std::cerr << "Error Parsing Bytecode\n";
-    //return false;
-    //}
-
-    //Loop over function names and global vars and add to symbol maps
-    for(Module::iterator I = M->begin(), E=M->end(); I != E; ++I) {
-      
-      //get function name
-      string NM = ((Function*)I)->getName();
-            
-      //Loop over the characters in the name and add to symbol name vector
-      for(unsigned i=0; i<NM.size(); ++i)
-	names.push_back(NM[i]);
-
-      //Each symbol is null terminated.
-      names.push_back('\0');
-
-      //Add offset to vector of offsets
-      offsets.push_back(memoff);
+// buildPaths - Convert the strings in the Members vector to sys::Path objects
+// and make sure they are valid and exist exist. This check is only needed for
+// the operations that add/replace files to the archive ('q' and 'r')
+bool buildPaths(bool checkExistence, std::string* ErrMsg) {
+  for (unsigned i = 0; i < Members.size(); i++) {
+    std::string aPath = Members[i];
+    if (checkExistence) {
+      bool IsDirectory;
+      error_code EC = sys::fs::is_directory(aPath, IsDirectory);
+      if (EC)
+        fail(aPath + ": " + EC.message());
+      if (IsDirectory)
+        fail(aPath + " Is a directory");
+
+      Paths.insert(aPath);
+    } else {
+      Paths.insert(aPath);
     }
-
-    memoff += Length + sizeof(Hdr);
   }
+  return false;
+}
 
-  //Determine how large our symbol table is.
-  unsigned symbolTableSize = sizeof(Hdr) + 4 + 4*(offsets.size()) + names.size();
-  std::cout << "Symbol Table Size: " << symbolTableSize << "\n";
-
-  //Number of symbols should be in network byte order as well
-  char num[4];
-  unsigned temp = offsets.size();
-  num[0] = (temp >> 24) & 255;
-  num[1] = (temp >> 16) & 255;
-  num[2] = (temp >> 8) & 255;
-  num[3] = temp & 255;
-
-  //Write number of symbols to archive file
-  ArchiveFile.write(num,4);
-
-  //Adjustment to offset to start files on even byte boundaries
-  unsigned adjust = 0;
-  
-  //Update offsets write symbol table to archive.
-  for(unsigned i=0; i<offsets.size(); ++i) {
-    char output[4];
-    offsets[i] = offsets[i] + symbolTableSize + SARMAG;
-    offsets[i] += adjust;
-    if((offsets[i] % 2 != 0)) {
-      adjust++;
-      offsets[i] += adjust;
+// doPrint - Implements the 'p' operation. This function traverses the archive
+// looking for members that match the path list. It is careful to uncompress
+// things that should be and to skip bitcode files unless the 'k' modifier was
+// given.
+bool doPrint(std::string* ErrMsg) {
+  if (buildPaths(false, ErrMsg))
+    return true;
+  for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
+       I != E; ++I ) {
+    if (Paths.empty() ||
+        (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
+      const char *data = reinterpret_cast<const char *>(I->getData());
+
+      // Skip things that don't make sense to print
+      if (I->isSVR4SymbolTable() || I->isBSD4SymbolTable())
+        continue;
+
+      if (Verbose)
+        outs() << "Printing " << I->getPath().str() << "\n";
+
+      unsigned len = I->getSize();
+      outs().write(data, len);
     }
-    
-    std::cout << "Offset: " << offsets[i] << "\n";
-    output[0] = (offsets[i] >> 24) & 255;
-    output[1] = (offsets[i] >> 16) & 255;
-    output[2] = (offsets[i] >> 8) & 255;
-    output[3] = offsets[i] & 255;
-    ArchiveFile.write(output,4);
   }
-
-
-  //Write out symbol name vector.
-  for(unsigned i=0; i<names.size(); ++i)
-    ArchiveFile << names[i];
-
-  return true;
+  return false;
 }
 
-// AddMemberToArchive - Writes member file to archive. Returns false on errors.
-// 
-// Overview of method: 
-// 1) Open file, and stat it.  
-// 2) Fill out header using stat information. If name is longer then 15 
-//    characters, use "dummy" name.
-// 3) Write header and file contents to disk.
-// 4) Keep track of total offset into file, and insert a newline if it is odd.
-//
-bool AddMemberToArchive(string Member, std::ofstream &ArchiveFile) {
-
-  std::cout << "Member File Start: " << ArchiveFile.tellp() << "\n";
-
-  ar_hdr Hdr; //Header for archive member file.
-
-  //stat the file to get info
-  struct stat StatBuf;
-  if (stat(Member.c_str(), &StatBuf) == -1 || StatBuf.st_size == 0)
-    return false;
-
-  //fill in header
-  
-  //set name to white spaces
-  memset(Hdr.name,' ', sizeof(Hdr.name));
-
-  //check the size of the name, if less than 15, we can copy it directly
-  //otherwise we give it a dummy name for now
-  if(Member.length() < 16)
-    memcpy(Hdr.name,Member.c_str(),Member.length());
+// putMode - utility function for printing out the file mode when the 't'
+// operation is in verbose mode.
+void
+printMode(unsigned mode) {
+  if (mode & 004)
+    outs() << "r";
   else
-    memcpy(Hdr.name, "Dummy", 5);
-
-  //terminate name with forward slash
-  Hdr.name[15] = '/';
-
-  //file member size in decimal
-  unsigned Length = StatBuf.st_size;
-  sprintf(Hdr.size,"%d", Length);
-  std::cout << "Size: " << Length << "\n";
-
-  //file member user id in decimal
-  sprintf(Hdr.uid, "%d", StatBuf.st_uid);
-
-  //file member group id in decimal
-  sprintf(Hdr.gid, "%d", StatBuf.st_gid);
-
-  //file member date in decimal
-  sprintf(Hdr.date,"%d", (int)StatBuf.st_mtime);
-  
-  //file member mode in OCTAL
-  sprintf(Hdr.mode,"%d", StatBuf.st_mode);
- 
-  //add our header trailer
-  memcpy(Hdr.fmag,ARFMAG,sizeof(ARFMAG));
-
-  //write header to archive file
-  ArchiveFile.write((char*)&Hdr, sizeof(Hdr));
-  
-  //open Member file for reading and copy to buffer
-  int FD = open(Member.c_str(),O_RDONLY);
-  if (FD == -1) {
-    std::cerr << "Error opening file!\n";
-    return false;
-  }
+    outs() << "-";
+  if (mode & 002)
+    outs() << "w";
+  else
+    outs() << "-";
+  if (mode & 001)
+    outs() << "x";
+  else
+    outs() << "-";
+}
 
-  unsigned char *buf = (unsigned char*)mmap(0, Length,PROT_READ,
-			  MAP_PRIVATE, FD, 0);
-  
-  //check if mmap failed
-  if (buf == (unsigned char*)MAP_FAILED) {
-    std::cerr << "Error mmapping file!\n";
-    return false;
+// doDisplayTable - Implement the 't' operation. This function prints out just
+// the file names of each of the members. However, if verbose mode is requested
+// ('v' modifier) then the file type, permission mode, user, group, size, and
+// modification time are also printed.
+bool
+doDisplayTable(std::string* ErrMsg) {
+  if (buildPaths(false, ErrMsg))
+    return true;
+  for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
+       I != E; ++I ) {
+    if (Paths.empty() ||
+        (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
+      if (Verbose) {
+        unsigned mode = I->getMode();
+        printMode((mode >> 6) & 007);
+        printMode((mode >> 3) & 007);
+        printMode(mode & 007);
+        outs() << ' ' << I->getUser();
+        outs() << "/" << I->getGroup();
+        outs() << ' ' << format("%6llu", I->getSize());
+        sys::TimeValue ModTime = I->getModTime();
+        outs() << " " << ModTime.str();
+        outs() << " " << I->getPath().str() << "\n";
+      } else {
+        outs() << I->getPath().str() << "\n";
+      }
+    }
   }
-
-  //write to archive file
-  ArchiveFile.write((char*)buf,Length);
-  
-  // Unmmap the memberfile
-  munmap((char*)buf, Length);
-  
-  std::cout << "Member File End: " << ArchiveFile.tellp() << "\n";
-
-  return true;
+  return false;
 }
 
+// doExtract - Implement the 'x' operation. This function extracts files back to
+// the file system.
+bool
+doExtract(std::string* ErrMsg) {
+  if (buildPaths(false, ErrMsg))
+    return true;
+  for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
+       I != E; ++I ) {
+    if (Paths.empty() ||
+        (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
+
+      // Open up a file stream for writing
+      int OpenFlags = O_TRUNC | O_WRONLY | O_CREAT;
+#ifdef O_BINARY
+      OpenFlags |= O_BINARY;
+#endif
+
+      // Retain the original mode.
+      sys::fs::perms Mode = sys::fs::perms(I->getMode());
+
+      int FD = open(I->getPath().str().c_str(), OpenFlags, Mode);
+      if (FD < 0)
+        return true;
+
+      {
+        raw_fd_ostream file(FD, false);
+
+        // Get the data and its length
+        const char* data = reinterpret_cast<const char*>(I->getData());
+        unsigned len = I->getSize();
+
+        // Write the data.
+        file.write(data, len);
+      }
+
+      // If we're supposed to retain the original modification times, etc. do so
+      // now.
+      if (OriginalDates) {
+        error_code EC =
+            sys::fs::setLastModificationAndAccessTime(FD, I->getModTime());
+        if (EC)
+          fail(EC.message());
+      }
+      if (close(FD))
+        return true;
+    }
+  }
+  return false;
+}
 
-// CreateArchive - Generates archive with or without symbol table.
-//
-void CreateArchive() {
-  
-  std::cerr << "Archive File: " << Archive << "\n";
-
-  //Create archive file for output.
-  std::ofstream ArchiveFile(Archive.c_str());
-  
-  //Check for errors opening or creating archive file.
-  if(!ArchiveFile.is_open() || ArchiveFile.bad() ) {
-    std::cerr << "Error opening Archive File\n";
-    exit(1);
+// doDelete - Implement the delete operation. This function deletes zero or more
+// members from the archive. Note that if the count is specified, there should
+// be no more than one path in the Paths list or else this algorithm breaks.
+// That check is enforced in parseCommandLine (above).
+bool
+doDelete(std::string* ErrMsg) {
+  if (buildPaths(false, ErrMsg))
+    return true;
+  if (Paths.empty())
+    return false;
+  for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
+       I != E; ) {
+    if (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end()) {
+      Archive::iterator J = I;
+      ++I;
+      TheArchive->erase(J);
+    } else {
+      ++I;
+    }
   }
 
-  //Write magic string to archive.
-  ArchiveFile << ARMAG;
+  // We're done editting, reconstruct the archive.
+  if (TheArchive->writeToDisk(ErrMsg))
+    return true;
+  return false;
+}
 
-  //If the '-s' option was specified, generate symbol table.
-  if(SymTable) {
-    std::cout << "Symbol Table Start: " << ArchiveFile.tellp() << "\n";
-    if(!WriteSymbolTable(ArchiveFile)) {
-      std::cerr << "Error creating symbol table. Exiting program.";
-      exit(1);
+// doMore - Implement the move operation. This function re-arranges just the
+// order of the archive members so that when the archive is written the move
+// of the members is accomplished. Note the use of the RelPos variable to
+// determine where the items should be moved to.
+bool
+doMove(std::string* ErrMsg) {
+  if (buildPaths(false, ErrMsg))
+    return true;
+
+  // By default and convention the place to move members to is the end of the
+  // archive.
+  Archive::iterator moveto_spot = TheArchive->end();
+
+  // However, if the relative positioning modifiers were used, we need to scan
+  // the archive to find the member in question. If we don't find it, its no
+  // crime, we just move to the end.
+  if (AddBefore || AddAfter) {
+    for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
+         I != E; ++I ) {
+      if (RelPos == I->getPath().str()) {
+        if (AddAfter) {
+          moveto_spot = I;
+          moveto_spot++;
+        } else {
+          moveto_spot = I;
+        }
+        break;
+      }
     }
-    std::cout << "Symbol Table End: " << ArchiveFile.tellp() << "\n";
   }
-  //Loop over all member files, and add to the archive.
-  for(unsigned i=0; i < Members.size(); ++i) {
-    if(ArchiveFile.tellp() % 2 != 0)
-      ArchiveFile << ARFMAG;
-    if(AddMemberToArchive(Members[i],ArchiveFile) != true) {
-      std::cerr << "Error adding " << Members[i] << "to archive. Exiting program.\n";
-      exit(1);
+
+  // Keep a list of the paths remaining to be moved
+  std::set<std::string> remaining(Paths);
+
+  // Scan the archive again, this time looking for the members to move to the
+  // moveto_spot.
+  for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
+       I != E && !remaining.empty(); ++I ) {
+    std::set<std::string>::iterator found =
+      std::find(remaining.begin(),remaining.end(), I->getPath());
+    if (found != remaining.end()) {
+      if (I != moveto_spot)
+        TheArchive->splice(moveto_spot,*TheArchive,I);
+      remaining.erase(found);
     }
   }
-  
-  //Close archive file.
-  ArchiveFile.close();
-}
 
-//Print out usage for errors in command line
-void printUse() {
-  std::cout << "USAGE: ar [-X32_64] [-]{dmpqrstx}[abcfilNoPsSuvV] [member-name] [count] archive-file [files..]\n\n";
-
-  std::cout << "commands:\n" <<
-    "d            - delete file(s) from the archive\n"
-  << "m[ab]        - move file(s) in the archive\n"
-  << "p            - print file(s) found in the archive\n"
-  << "q[f]         - quick append file(s) to the archive\n"
-  << "r[ab][f][u]  - replace existing or insert new file(s) into the archive\n"
-  << "t            - display contents of archive\n"
-  << "x[o]         - extract file(s) from the archive\n";
-
-  std::cout << "\ncommand specific modifiers:\n"
-	    << "[a]          - put file(s) after [member-name]\n"
-	    << "[b]          - put file(s) before [member-name] (same as [i])\n"
-	    << "[N]          - use instance [count] of name\n"
-	    << "[f]          - truncate inserted file names\n"
-	    << "[P]          - use full path names when matching\n"
-	    << "[o]          - preserve original dates\n"
-	    << "[u]          - only replace files that are newer than current archive contents\n";
-
-  std::cout << "generic modifiers:\n"
-	    << "[c]          - do not warn if the library had to be created\n"
-	    << "[s]          - create an archive index (cf. ranlib)\n"
-	    << "[S]          - do not build a symbol table\n"
-	    << "[v]          - be verbose\n"
-	    << "[V]          - display the version number\n";
-  exit(1);
+  // We're done editting, reconstruct the archive.
+  if (TheArchive->writeToDisk(ErrMsg))
+    return true;
+  return false;
 }
 
+// doQuickAppend - Implements the 'q' operation. This function just
+// indiscriminantly adds the members to the archive and rebuilds it.
+bool
+doQuickAppend(std::string* ErrMsg) {
+  // Get the list of paths to append.
+  if (buildPaths(true, ErrMsg))
+    return true;
+  if (Paths.empty())
+    return false;
 
-//Print version
-void printVersion() {
-  std::cout << VERSION;
-  exit(0);
-}
-
-//Extract the memberfile name from the command line
-void getRelPos() {
-  if(RestofArgs.size() > 0) {
-    RelPos = RestofArgs[0];
-    RestofArgs.erase(RestofArgs.begin());
+  // Append them quickly.
+  for (std::set<std::string>::iterator PI = Paths.begin(), PE = Paths.end();
+       PI != PE; ++PI) {
+    if (TheArchive->addFileBefore(*PI, TheArchive->end(), ErrMsg))
+      return true;
   }
-  //Throw error if needed and not present
-  else
-    printUse();
-}
 
-//Extract count from the command line
-void getCount() {
-  if(RestofArgs.size() > 0) {
-    Count = atoi(RestofArgs[0].c_str());
-    RestofArgs.erase(RestofArgs.begin());
-  }
-  //Throw error if needed and not present
-  else
-    printUse();
+  // We're done editting, reconstruct the archive.
+  if (TheArchive->writeToDisk(ErrMsg))
+    return true;
+  return false;
 }
 
-//Get the Archive File Name from the command line
-void getArchive() {
-  std::cerr << RestofArgs.size() << "\n";
-  if(RestofArgs.size() > 0) {
-    Archive = RestofArgs[0];
-    RestofArgs.erase(RestofArgs.begin());
-  }
-  //Throw error if needed and not present
-  else
-    printUse();
-}
+// doReplaceOrInsert - Implements the 'r' operation. This function will replace
+// any existing files or insert new ones into the archive.
+bool
+doReplaceOrInsert(std::string* ErrMsg) {
 
+  // Build the list of files to be added/replaced.
+  if (buildPaths(true, ErrMsg))
+    return true;
+  if (Paths.empty())
+    return false;
 
-//Copy over remaining items in RestofArgs to our Member File vector.
-//This is just for clarity.
-void getMembers() {
-  std::cerr << RestofArgs.size() << "\n";
-  if(RestofArgs.size() > 0)
-    Members = std::vector<string>(RestofArgs); 
-}
+  // Keep track of the paths that remain to be inserted.
+  std::set<std::string> remaining(Paths);
 
-// Parse the operations and operation modifiers
-// FIXME: Not all of these options has been implemented, but we still
-// do all the command line parsing for them.
-void parseCL() {
+  // Default the insertion spot to the end of the archive
+  Archive::iterator insert_spot = TheArchive->end();
 
-  //Keep track of number of operations. We can only specify one
-  //per execution
-  unsigned NumOperations = 0;
+  // Iterate over the archive contents
+  for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
+       I != E && !remaining.empty(); ++I ) {
 
-  for(unsigned i=0; i<Options.size(); ++i) {
-    switch(Options[i]) {
-    case 'd':
-      ++NumOperations;
-      Delete = true;
-      break;
-    case 'm':
-      ++NumOperations;
-      Move = true;
-      break;
-    case 'p':
-      ++NumOperations;
-      Print = true;
-      break;
-    case 'r':
-      ++NumOperations;
-      InsertWithReplacement = true;
-      break;
-    case 't':
-      ++NumOperations;
-      DisplayTable = true;
-      break;
-    case 'x':
-      ++NumOperations;
-      Extract = true;
-      break;
-    case 'a':
-      AddAfter = true;
-      getRelPos();
-      break;
-    case 'b':
-      AddBefore = true;
-      getRelPos();
-      break;
-    case 'c':
-      Create = true;
-      break;
-    case 'f':
-      TruncateNames = true;
-      break;
-    case 'i':
-      InsertBefore = true;
-      getRelPos();
-      break;
-    case 'l':
-      break;
-    case 'N':
-      UseCount = true;
-      getCount();
-      break;
-    case 'o':
-      OriginalDates = true;
-      break;
-    case 'P':
-      FullPath = true;
-      break;
-    case 's':
-      SymTable = true;
-      break;
-    case 'S':
-      SymTable = false;
-      break;
-    case 'u':
-      OnlyUpdate = true;
-      break;
-    case 'v':
-      Verbose = true;
-      break;
-    case 'V':
-      printVersion();
-      break;
-    default:
-      printUse();
+    // Determine if this archive member matches one of the paths we're trying
+    // to replace.
+
+    std::set<std::string>::iterator found = remaining.end();
+    for (std::set<std::string>::iterator RI = remaining.begin(),
+         RE = remaining.end(); RI != RE; ++RI ) {
+      std::string compare(sys::path::filename(*RI));
+      if (compare == I->getPath().str()) {
+        found = RI;
+        break;
+      }
+    }
+
+    if (found != remaining.end()) {
+      sys::fs::file_status Status;
+      error_code EC = sys::fs::status(*found, Status);
+      if (EC)
+        return true;
+      if (!sys::fs::is_directory(Status)) {
+        if (OnlyUpdate) {
+          // Replace the item only if it is newer.
+          if (Status.getLastModificationTime() > I->getModTime())
+            if (I->replaceWith(*found, ErrMsg))
+              return true;
+        } else {
+          // Replace the item regardless of time stamp
+          if (I->replaceWith(*found, ErrMsg))
+            return true;
+        }
+      } else {
+        // We purposefully ignore directories.
+      }
+
+      // Remove it from our "to do" list
+      remaining.erase(found);
+    }
+
+    // Determine if this is the place where we should insert
+    if (AddBefore && RelPos == I->getPath().str())
+      insert_spot = I;
+    else if (AddAfter && RelPos == I->getPath().str()) {
+      insert_spot = I;
+      insert_spot++;
     }
   }
 
-  //Check that only one operation has been specified
-  if(NumOperations > 1)
-    printUse();
+  // If we didn't replace all the members, some will remain and need to be
+  // inserted at the previously computed insert-spot.
+  if (!remaining.empty()) {
+    for (std::set<std::string>::iterator PI = remaining.begin(),
+         PE = remaining.end(); PI != PE; ++PI) {
+      if (TheArchive->addFileBefore(*PI, insert_spot, ErrMsg))
+        return true;
+    }
+  }
 
-  getArchive();
-  getMembers();
+  // We're done editting, reconstruct the archive.
+  if (TheArchive->writeToDisk(ErrMsg))
+    return true;
+  return false;
+}
+
+bool shouldCreateArchive(ArchiveOperation Op) {
+  switch (Op) {
+  case Print:
+  case Delete:
+  case Move:
+  case DisplayTable:
+  case Extract:
+    return false;
 
+  case QuickAppend:
+  case ReplaceOrInsert:
+    return true;
+  }
+
+  llvm_unreachable("Missing entry in covered switch.");
 }
 
+// main - main program for llvm-ar .. see comments in the code
 int main(int argc, char **argv) {
-  cl::ParseCommandLineOptions(argc, argv);
+  program_name = argv[0];
+  // Print a stack trace if we signal out.
   sys::PrintStackTraceOnErrorSignal();
+  PrettyStackTraceProgram X(argc, argv);
+  LLVMContext &Context = getGlobalContext();
+  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+
+  // Have the command line options parsed and handle things
+  // like --help and --version.
+  cl::ParseCommandLineOptions(argc, argv,
+    "LLVM Archiver (llvm-ar)\n\n"
+    "  This program archives bitcode files into single libraries\n"
+  );
+
+  int exitCode = 0;
+
+  // Do our own parsing of the command line because the CommandLine utility
+  // can't handle the grouped positional parameters without a dash.
+  ArchiveOperation Operation = parseCommandLine();
+
+  // Create or open the archive object.
+  if (shouldCreateArchive(Operation) && !llvm::sys::fs::exists(ArchiveName)) {
+    // Produce a warning if we should and we're creating the archive
+    if (!Create)
+      errs() << argv[0] << ": creating " << ArchiveName << "\n";
+    TheArchive = Archive::CreateEmpty(ArchiveName, Context);
+    TheArchive->writeToDisk();
+  }
+
+  if (!TheArchive) {
+    std::string Error;
+    TheArchive = Archive::OpenAndLoad(ArchiveName, Context, &Error);
+    if (TheArchive == 0) {
+      errs() << argv[0] << ": error loading '" << ArchiveName << "': "
+             << Error << "!\n";
+      return 1;
+    }
+  }
 
-  parseCL();
+  // Make sure we're not fooling ourselves.
+  assert(TheArchive && "Unable to instantiate the archive");
+
+  // Perform the operation
+  std::string ErrMsg;
+  bool haveError = false;
+  switch (Operation) {
+    case Print:           haveError = doPrint(&ErrMsg); break;
+    case Delete:          haveError = doDelete(&ErrMsg); break;
+    case Move:            haveError = doMove(&ErrMsg); break;
+    case QuickAppend:     haveError = doQuickAppend(&ErrMsg); break;
+    case ReplaceOrInsert: haveError = doReplaceOrInsert(&ErrMsg); break;
+    case DisplayTable:    haveError = doDisplayTable(&ErrMsg); break;
+    case Extract:         haveError = doExtract(&ErrMsg); break;
+  }
+  if (haveError) {
+    errs() << argv[0] << ": " << ErrMsg << "\n";
+    return 1;
+  }
 
-  //Create archive!
-  if(Create)
-    CreateArchive();
+  delete TheArchive;
+  TheArchive = 0;
 
-  return 0;
+  // Return result code back to operating system.
+  return exitCode;
 }
-