Simplify boolean expressions in tools/llvm-objdump.
[oota-llvm.git] / tools / llvm-ar / llvm-ar.cpp
index 2f1eb3b486a18197c0dfed473aea8dd0446291d1..ec3cfcb5cad014ed265afbd24eb9d76de9a170d4 100644 (file)
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
+#include "llvm/LibDriver/LibDriver.h"
 #include "llvm/Object/Archive.h"
+#include "llvm/Object/ArchiveWriter.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Errc.h"
@@ -24,6 +27,7 @@
 #include "llvm/Support/LineIterator.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/TargetSelect.h"
@@ -44,16 +48,9 @@ using namespace llvm;
 // The name this program was invoked as.
 static StringRef ToolName;
 
-static const char *TemporaryOutput;
-static int TmpArchiveFD = -1;
-
 // Show the error message and exit.
 LLVM_ATTRIBUTE_NORETURN static void fail(Twine Error) {
   outs() << ToolName << ": " << Error << ".\n";
-  if (TmpArchiveFD != -1)
-    close(TmpArchiveFD);
-  if (TemporaryOutput)
-    sys::fs::remove(TemporaryOutput);
   exit(1);
 }
 
@@ -74,6 +71,16 @@ static cl::list<std::string>
 
 static cl::opt<bool> MRI("M", cl::desc(""));
 
+namespace {
+enum Format { Default, GNU, BSD };
+}
+
+static cl::opt<Format>
+    FormatOpt("format", cl::desc("Archive format to create"),
+              cl::values(clEnumValN(Default, "defalut", "default"),
+                         clEnumValN(GNU, "gnu", "gnu"),
+                         clEnumValN(BSD, "bsd", "bsd"), clEnumValEnd));
+
 std::string Options;
 
 // Provide additional help output explaining the operations and modifiers of
@@ -122,6 +129,8 @@ static bool OriginalDates = false; ///< 'o' modifier
 static bool OnlyUpdate = false;    ///< 'u' modifier
 static bool Verbose = false;       ///< 'v' modifier
 static bool Symtab = true;         ///< 's' modifier
+static bool Deterministic = true;  ///< 'D' and 'U' modifiers
+static bool Thin = false;          ///< 'T' modifier
 
 // Relative Positional Argument (for insert/move). This variable holds
 // the name of the archive member to which the 'a', 'b' or 'i' modifier
@@ -238,6 +247,15 @@ static ArchiveOperation parseCommandLine() {
       AddBefore = true;
       NumPositional++;
       break;
+    case 'D':
+      Deterministic = true;
+      break;
+    case 'U':
+      Deterministic = false;
+      break;
+    case 'T':
+      Thin = true;
+      break;
     default:
       cl::PrintHelpMessage();
     }
@@ -281,11 +299,13 @@ static ArchiveOperation parseCommandLine() {
 
 // Implements the 'p' operation. This function traverses the archive
 // looking for members that match the path list.
-static void doPrint(StringRef Name, object::Archive::child_iterator I) {
+static void doPrint(StringRef Name, const object::Archive::Child &C) {
   if (Verbose)
     outs() << "Printing " << Name << "\n";
 
-  StringRef Data = I->getBuffer();
+  ErrorOr<StringRef> DataOrErr = C.getBuffer();
+  failIfError(DataOrErr.getError());
+  StringRef Data = *DataOrErr;
   outs().write(Data.data(), Data.size());
 }
 
@@ -310,16 +330,16 @@ static void printMode(unsigned mode) {
 // 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.
-static void doDisplayTable(StringRef Name, object::Archive::child_iterator I) {
+static void doDisplayTable(StringRef Name, const object::Archive::Child &C) {
   if (Verbose) {
-    sys::fs::perms Mode = I->getAccessMode();
+    sys::fs::perms Mode = C.getAccessMode();
     printMode((Mode >> 6) & 007);
     printMode((Mode >> 3) & 007);
     printMode(Mode & 007);
-    outs() << ' ' << I->getUID();
-    outs() << '/' << I->getGID();
-    outs() << ' ' << format("%6llu", I->getSize());
-    outs() << ' ' << I->getLastModified().str();
+    outs() << ' ' << C.getUID();
+    outs() << '/' << C.getGID();
+    outs() << ' ' << format("%6llu", C.getSize());
+    outs() << ' ' << C.getLastModified().str();
     outs() << ' ';
   }
   outs() << Name << "\n";
@@ -327,9 +347,9 @@ static void doDisplayTable(StringRef Name, object::Archive::child_iterator I) {
 
 // Implement the 'x' operation. This function extracts files back to the file
 // system.
-static void doExtract(StringRef Name, object::Archive::child_iterator I) {
+static void doExtract(StringRef Name, const object::Archive::Child &C) {
   // Retain the original mode.
-  sys::fs::perms Mode = I->getAccessMode();
+  sys::fs::perms Mode = C.getAccessMode();
   SmallString<128> Storage = Name;
 
   int FD;
@@ -341,7 +361,7 @@ static void doExtract(StringRef Name, object::Archive::child_iterator I) {
     raw_fd_ostream file(FD, false);
 
     // Get the data and its length
-    StringRef Data = I->getBuffer();
+    StringRef Data = *C.getBuffer();
 
     // Write the data.
     file.write(Data.data(), Data.size());
@@ -351,7 +371,7 @@ static void doExtract(StringRef Name, object::Archive::child_iterator I) {
   // now.
   if (OriginalDates)
     failIfError(
-        sys::fs::setLastModificationAndAccessTime(FD, I->getLastModified()));
+        sys::fs::setLastModificationAndAccessTime(FD, C.getLastModified()));
 
   if (close(FD))
     fail("Could not close the file");
@@ -377,100 +397,59 @@ static bool shouldCreateArchive(ArchiveOperation Op) {
 
 static void performReadOperation(ArchiveOperation Operation,
                                  object::Archive *OldArchive) {
-  for (object::Archive::child_iterator I = OldArchive->child_begin(),
-                                       E = OldArchive->child_end();
-       I != E; ++I) {
-    ErrorOr<StringRef> NameOrErr = I->getName();
+  if (Operation == Extract && OldArchive->isThin()) {
+    errs() << "extracting from a thin archive is not supported\n";
+    std::exit(1);
+  }
+
+  bool Filter = !Members.empty();
+  for (const object::Archive::Child &C : OldArchive->children()) {
+    ErrorOr<StringRef> NameOrErr = C.getName();
     failIfError(NameOrErr.getError());
     StringRef Name = NameOrErr.get();
 
-    if (!Members.empty() &&
-        std::find(Members.begin(), Members.end(), Name) == Members.end())
-      continue;
+    if (Filter) {
+      auto I = std::find(Members.begin(), Members.end(), Name);
+      if (I == Members.end())
+        continue;
+      Members.erase(I);
+    }
 
     switch (Operation) {
     default:
       llvm_unreachable("Not a read operation");
     case Print:
-      doPrint(Name, I);
+      doPrint(Name, C);
       break;
     case DisplayTable:
-      doDisplayTable(Name, I);
+      doDisplayTable(Name, C);
       break;
     case Extract:
-      doExtract(Name, I);
+      doExtract(Name, C);
       break;
     }
   }
+  if (Members.empty())
+    return;
+  for (StringRef Name : Members)
+    errs() << Name << " was not found\n";
+  std::exit(1);
 }
 
-namespace {
-class NewArchiveIterator {
-  bool IsNewMember;
-  StringRef Name;
-
-  object::Archive::child_iterator OldI;
-
-  StringRef NewFilename;
-
-public:
-  NewArchiveIterator(object::Archive::child_iterator I, StringRef Name);
-  NewArchiveIterator(StringRef I, StringRef Name);
-  NewArchiveIterator();
-  bool isNewMember() const;
-  StringRef getName() const;
-
-  object::Archive::child_iterator getOld() const;
-
-  StringRef getNew() const;
-  int getFD(sys::fs::file_status &NewStatus) const;
-  const sys::fs::file_status &getStatus() const;
-};
-}
-
-NewArchiveIterator::NewArchiveIterator() {}
-
-NewArchiveIterator::NewArchiveIterator(object::Archive::child_iterator I,
-                                       StringRef Name)
-    : IsNewMember(false), Name(Name), OldI(I) {}
-
-NewArchiveIterator::NewArchiveIterator(StringRef NewFilename, StringRef Name)
-    : IsNewMember(true), Name(Name), NewFilename(NewFilename) {}
-
-StringRef NewArchiveIterator::getName() const { return Name; }
-
-bool NewArchiveIterator::isNewMember() const { return IsNewMember; }
-
-object::Archive::child_iterator NewArchiveIterator::getOld() const {
-  assert(!IsNewMember);
-  return OldI;
-}
-
-StringRef NewArchiveIterator::getNew() const {
-  assert(IsNewMember);
-  return NewFilename;
-}
-
-int NewArchiveIterator::getFD(sys::fs::file_status &NewStatus) const {
-  assert(IsNewMember);
-  int NewFD;
-  failIfError(sys::fs::openFileForRead(NewFilename, NewFD), NewFilename);
-  assert(NewFD != -1);
-
-  failIfError(sys::fs::status(NewFD, NewStatus), NewFilename);
-
-  // Opening a directory doesn't make sense. Let it fail.
-  // Linux cannot open directories with open(2), although
-  // cygwin and *bsd can.
-  if (NewStatus.type() == sys::fs::file_type::directory_file)
-    failIfError(make_error_code(errc::is_a_directory), NewFilename);
-
-  return NewFD;
+void addMember(std::vector<NewArchiveIterator> &Members, StringRef FileName,
+               int Pos = -1) {
+  NewArchiveIterator NI(FileName);
+  if (Pos == -1)
+    Members.push_back(NI);
+  else
+    Members[Pos] = NI;
 }
 
-template <typename T>
-void addMember(std::vector<NewArchiveIterator> &Members, T I, StringRef Name,
+void addMember(std::vector<NewArchiveIterator> &Members,
+               object::Archive::child_iterator I, StringRef Name,
                int Pos = -1) {
+  if (Thin && !I->getParent()->isThin())
+    fail("Cannot convert a regular archive to a thin one");
   NewArchiveIterator NI(I, Name);
   if (Pos == -1)
     Members.push_back(NI);
@@ -565,7 +544,7 @@ computeNewArchiveMembers(ArchiveOperation Operation,
         addMember(Ret, Child, Name);
         break;
       case IA_AddNewMeber:
-        addMember(Ret, *MemberI, Name);
+        addMember(Ret, *MemberI);
         break;
       case IA_Delete:
         break;
@@ -573,7 +552,7 @@ computeNewArchiveMembers(ArchiveOperation Operation,
         addMember(Moved, Child, Name);
         break;
       case IA_MoveNewMember:
-        addMember(Moved, *MemberI, Name);
+        addMember(Moved, *MemberI);
         break;
       }
       if (MemberI != Members.end())
@@ -593,280 +572,47 @@ computeNewArchiveMembers(ArchiveOperation Operation,
   assert(unsigned(InsertPos) <= Ret.size());
   Ret.insert(Ret.begin() + InsertPos, Moved.begin(), Moved.end());
 
-  Ret.insert(Ret.begin() + InsertPos, Members.size(), NewArchiveIterator());
+  Ret.insert(Ret.begin() + InsertPos, Members.size(), NewArchiveIterator(""));
   int Pos = InsertPos;
   for (auto &Member : Members) {
-    StringRef Name = sys::path::filename(Member);
-    addMember(Ret, Member, Name, Pos);
+    addMember(Ret, Member, Pos);
     ++Pos;
   }
 
   return Ret;
 }
 
-template <typename T>
-static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
-                                 bool MayTruncate = false) {
-  uint64_t OldPos = OS.tell();
-  OS << Data;
-  unsigned SizeSoFar = OS.tell() - OldPos;
-  if (Size > SizeSoFar) {
-    unsigned Remaining = Size - SizeSoFar;
-    for (unsigned I = 0; I < Remaining; ++I)
-      OS << ' ';
-  } else if (Size < SizeSoFar) {
-    assert(MayTruncate && "Data doesn't fit in Size");
-    // Some of the data this is used for (like UID) can be larger than the
-    // space available in the archive format. Truncate in that case.
-    OS.seek(OldPos + Size);
-  }
-}
-
-static void print32BE(raw_fd_ostream &Out, unsigned Val) {
-  for (int I = 3; I >= 0; --I) {
-    char V = (Val >> (8 * I)) & 0xff;
-    Out << V;
-  }
-}
-
-static void printRestOfMemberHeader(raw_fd_ostream &Out,
-                                    const sys::TimeValue &ModTime, unsigned UID,
-                                    unsigned GID, unsigned Perms,
-                                    unsigned Size) {
-  printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
-  printWithSpacePadding(Out, UID, 6, true);
-  printWithSpacePadding(Out, GID, 6, true);
-  printWithSpacePadding(Out, format("%o", Perms), 8);
-  printWithSpacePadding(Out, Size, 10);
-  Out << "`\n";
-}
-
-static void printMemberHeader(raw_fd_ostream &Out, StringRef Name,
-                              const sys::TimeValue &ModTime, unsigned UID,
-                              unsigned GID, unsigned Perms, unsigned Size) {
-  printWithSpacePadding(Out, Twine(Name) + "/", 16);
-  printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
-}
-
-static void printMemberHeader(raw_fd_ostream &Out, unsigned NameOffset,
-                              const sys::TimeValue &ModTime, unsigned UID,
-                              unsigned GID, unsigned Perms, unsigned Size) {
-  Out << '/';
-  printWithSpacePadding(Out, NameOffset, 15);
-  printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
-}
-
-static void writeStringTable(raw_fd_ostream &Out,
-                             ArrayRef<NewArchiveIterator> Members,
-                             std::vector<unsigned> &StringMapIndexes) {
-  unsigned StartOffset = 0;
-  for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
-                                              E = Members.end();
-       I != E; ++I) {
-    StringRef Name = I->getName();
-    if (Name.size() < 16)
-      continue;
-    if (StartOffset == 0) {
-      printWithSpacePadding(Out, "//", 58);
-      Out << "`\n";
-      StartOffset = Out.tell();
-    }
-    StringMapIndexes.push_back(Out.tell() - StartOffset);
-    Out << Name << "/\n";
-  }
-  if (StartOffset == 0)
-    return;
-  if (Out.tell() % 2)
-    Out << '\n';
-  int Pos = Out.tell();
-  Out.seek(StartOffset - 12);
-  printWithSpacePadding(Out, Pos - StartOffset, 10);
-  Out.seek(Pos);
-}
-
-// Returns the offset of the first reference to a member offset.
-static unsigned writeSymbolTable(raw_fd_ostream &Out,
-                                 ArrayRef<NewArchiveIterator> Members,
-                                 ArrayRef<MemoryBufferRef> Buffers,
-                                 std::vector<unsigned> &MemberOffsetRefs) {
-  unsigned StartOffset = 0;
-  unsigned MemberNum = 0;
-  std::string NameBuf;
-  raw_string_ostream NameOS(NameBuf);
-  unsigned NumSyms = 0;
-  LLVMContext &Context = getGlobalContext();
-  for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
-                                              E = Members.end();
-       I != E; ++I, ++MemberNum) {
-    MemoryBufferRef MemberBuffer = Buffers[MemberNum];
-    ErrorOr<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
-        object::SymbolicFile::createSymbolicFile(
-            MemberBuffer, sys::fs::file_magic::unknown, &Context);
-    if (!ObjOrErr)
-      continue;  // FIXME: check only for "not an object file" errors.
-    object::SymbolicFile &Obj = *ObjOrErr.get();
-
-    if (!StartOffset) {
-      printMemberHeader(Out, "", sys::TimeValue::now(), 0, 0, 0, 0);
-      StartOffset = Out.tell();
-      print32BE(Out, 0);
-    }
-
-    for (const object::BasicSymbolRef &S : Obj.symbols()) {
-      uint32_t Symflags = S.getFlags();
-      if (Symflags & object::SymbolRef::SF_FormatSpecific)
-        continue;
-      if (!(Symflags & object::SymbolRef::SF_Global))
-        continue;
-      if (Symflags & object::SymbolRef::SF_Undefined)
-        continue;
-      failIfError(S.printName(NameOS));
-      NameOS << '\0';
-      ++NumSyms;
-      MemberOffsetRefs.push_back(MemberNum);
-      print32BE(Out, 0);
-    }
-  }
-  Out << NameOS.str();
-
-  if (StartOffset == 0)
-    return 0;
-
-  if (Out.tell() % 2)
-    Out << '\0';
-
-  unsigned Pos = Out.tell();
-  Out.seek(StartOffset - 12);
-  printWithSpacePadding(Out, Pos - StartOffset, 10);
-  Out.seek(StartOffset);
-  print32BE(Out, NumSyms);
-  Out.seek(Pos);
-  return StartOffset + 4;
-}
-
 static void
 performWriteOperation(ArchiveOperation Operation, object::Archive *OldArchive,
-                      std::vector<NewArchiveIterator> &NewMembers) {
-  SmallString<128> TmpArchive;
-  failIfError(sys::fs::createUniqueFile(ArchiveName + ".temp-archive-%%%%%%%.a",
-                                        TmpArchiveFD, TmpArchive));
-
-  TemporaryOutput = TmpArchive.c_str();
-  tool_output_file Output(TemporaryOutput, TmpArchiveFD);
-  raw_fd_ostream &Out = Output.os();
-  Out << "!<arch>\n";
-
-  std::vector<unsigned> MemberOffsetRefs;
-
-  std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
-  std::vector<MemoryBufferRef> Members;
-  std::vector<sys::fs::file_status> NewMemberStatus;
-
-  for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
-    NewArchiveIterator &Member = NewMembers[I];
-    MemoryBufferRef MemberRef;
-
-    if (Member.isNewMember()) {
-      StringRef Filename = Member.getNew();
-      NewMemberStatus.resize(NewMemberStatus.size() + 1);
-      sys::fs::file_status &Status = NewMemberStatus.back();
-      int FD = Member.getFD(Status);
-      ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
-          MemoryBuffer::getOpenFile(FD, Filename, Status.getSize(), false);
-      failIfError(MemberBufferOrErr.getError(), Filename);
-      if (close(FD) != 0)
-        fail("Could not close file");
-      Buffers.push_back(std::move(MemberBufferOrErr.get()));
-      MemberRef = Buffers.back()->getMemBufferRef();
-    } else {
-      object::Archive::child_iterator OldMember = Member.getOld();
-      ErrorOr<MemoryBufferRef> MemberBufferOrErr =
-          OldMember->getMemoryBufferRef();
-      failIfError(MemberBufferOrErr.getError());
-      MemberRef = MemberBufferOrErr.get();
-    }
-    Members.push_back(MemberRef);
-  }
-
-  unsigned MemberReferenceOffset = 0;
-  if (Symtab) {
-    MemberReferenceOffset =
-        writeSymbolTable(Out, NewMembers, Members, MemberOffsetRefs);
-  }
-
-  std::vector<unsigned> StringMapIndexes;
-  writeStringTable(Out, NewMembers, StringMapIndexes);
-
-  unsigned MemberNum = 0;
-  unsigned LongNameMemberNum = 0;
-  unsigned NewMemberNum = 0;
-  std::vector<unsigned> MemberOffset;
-  for (std::vector<NewArchiveIterator>::iterator I = NewMembers.begin(),
-                                                 E = NewMembers.end();
-       I != E; ++I, ++MemberNum) {
-
-    unsigned Pos = Out.tell();
-    MemberOffset.push_back(Pos);
-
-    MemoryBufferRef File = Members[MemberNum];
-    if (I->isNewMember()) {
-      StringRef FileName = I->getNew();
-      const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum];
-      NewMemberNum++;
-
-      StringRef Name = sys::path::filename(FileName);
-      if (Name.size() < 16)
-        printMemberHeader(Out, Name, Status.getLastModificationTime(),
-                          Status.getUser(), Status.getGroup(),
-                          Status.permissions(), Status.getSize());
-      else
-        printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
-                          Status.getLastModificationTime(), Status.getUser(),
-                          Status.getGroup(), Status.permissions(),
-                          Status.getSize());
-    } else {
-      object::Archive::child_iterator OldMember = I->getOld();
-      StringRef Name = I->getName();
-
-      if (Name.size() < 16)
-        printMemberHeader(Out, Name, OldMember->getLastModified(),
-                          OldMember->getUID(), OldMember->getGID(),
-                          OldMember->getAccessMode(), OldMember->getSize());
-      else
-        printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
-                          OldMember->getLastModified(), OldMember->getUID(),
-                          OldMember->getGID(), OldMember->getAccessMode(),
-                          OldMember->getSize());
-    }
-
-    Out << File.getBuffer();
-
-    if (Out.tell() % 2)
-      Out << '\n';
+                      std::vector<NewArchiveIterator> *NewMembersP) {
+  object::Archive::Kind Kind;
+  switch (FormatOpt) {
+  case Default: {
+    Triple T(sys::getProcessTriple());
+    if (T.isOSDarwin())
+      Kind = object::Archive::K_BSD;
+    else
+      Kind = object::Archive::K_GNU;
+    break;
   }
-
-  if (MemberReferenceOffset) {
-    Out.seek(MemberReferenceOffset);
-    for (unsigned MemberNum : MemberOffsetRefs)
-      print32BE(Out, MemberOffset[MemberNum]);
+  case GNU:
+    Kind = object::Archive::K_GNU;
+    break;
+  case BSD:
+    Kind = object::Archive::K_BSD;
+    break;
   }
-
-  Output.keep();
-  Out.close();
-  sys::fs::rename(TemporaryOutput, ArchiveName);
-  TemporaryOutput = nullptr;
-}
-
-static void
-performWriteOperation(ArchiveOperation Operation, object::Archive *OldArchive,
-                      std::vector<NewArchiveIterator> *NewMembersP) {
   if (NewMembersP) {
-    performWriteOperation(Operation, OldArchive, *NewMembersP);
+    std::pair<StringRef, std::error_code> Result = writeArchive(
+        ArchiveName, *NewMembersP, Symtab, Kind, Deterministic, Thin);
+    failIfError(Result.second, Result.first);
     return;
   }
   std::vector<NewArchiveIterator> NewMembers =
       computeNewArchiveMembers(Operation, OldArchive);
-  performWriteOperation(Operation, OldArchive, NewMembers);
+  auto Result =
+      writeArchive(ArchiveName, NewMembers, Symtab, Kind, Deterministic, Thin);
+  failIfError(Result.second, Result.first);
 }
 
 static void createSymbolTable(object::Archive *OldArchive) {
@@ -988,7 +734,7 @@ static void runMRIScript() {
       break;
     }
     case MRICommand::AddMod:
-      addMember(NewMembers, Rest, sys::path::filename(Rest));
+      addMember(NewMembers, Rest);
       break;
     case MRICommand::Create:
       Create = true;
@@ -1035,6 +781,15 @@ int main(int argc, char **argv) {
   PrettyStackTraceProgram X(argc, argv);
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 
+  llvm::InitializeAllTargetInfos();
+  llvm::InitializeAllTargetMCs();
+  llvm::InitializeAllAsmParsers();
+
+  StringRef Stem = sys::path::stem(ToolName);
+  if (Stem.find("ranlib") == StringRef::npos &&
+      Stem.find("lib") != StringRef::npos)
+    return libDriverMain(makeArrayRef(argv, argc));
+
   // Have the command line options parsed and handle things
   // like --help and --version.
   cl::ParseCommandLineOptions(argc, argv,
@@ -1042,14 +797,9 @@ int main(int argc, char **argv) {
     "  This program archives bitcode files into single libraries\n"
   );
 
-  llvm::InitializeAllTargetInfos();
-  llvm::InitializeAllTargetMCs();
-  llvm::InitializeAllAsmParsers();
-
-  StringRef Stem = sys::path::stem(ToolName);
   if (Stem.find("ar") != StringRef::npos)
     return ar_main();
   if (Stem.find("ranlib") != StringRef::npos)
     return ranlib_main();
-  fail("Not ranlib or ar!");
+  fail("Not ranlib, ar or lib!");
 }