Change llvm-ar to use lib/Object.

This fixes two bugs is lib/Object that the use in llvm-ar found:
* In OS X created archives, the name can be padded with nulls. Strip them.
* In the constructor, remember the first non special member and use that in
  begin_children. This makes sure we skip all special members, not just the
  first one.

The change to llvm-ar itself consist of
* Using lib/Object for reading archives instead of ArchiveReader.cpp.
* Writing the modified archive directly, instead of creating an in memory
  representation.

The old Archive library was way more general than what is needed, as can
be seen by the diffstat of this patch.

Having llvm-ar using lib/Object now opens the way for creating regular symbol
tables for both native objects and bitcode files so that we can use those
archives for LTO.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186197 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 288 deletions

diff --git a/tools/llvm-ar/ArchiveWriter.cpp b/tools/llvm-ar/ArchiveWriter.cpp
deleted file mode 100644
index bdccf3e0d9..0000000000
--- a/tools/llvm-ar/ArchiveWriter.cpp
+++ /dev/null
@@ -1,288 +0,0 @@
-//===-- ArchiveWriter.cpp - Write LLVM archive files ----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// Builds up an LLVM archive file (.a) containing LLVM bitcode.
-//
-//===----------------------------------------------------------------------===//
-
-#include "Archive.h"
-#include "ArchiveInternals.h"
-#include "llvm/ADT/OwningPtr.h"
-#include "llvm/Bitcode/ReaderWriter.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Support/FileSystem.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/Process.h"
-#include "llvm/Support/Signals.h"
-#include "llvm/Support/system_error.h"
-#include <fstream>
-#include <iomanip>
-#include <ostream>
-using namespace llvm;
-
-// Write an integer using variable bit rate encoding. This saves a few bytes
-// per entry in the symbol table.
-static inline void writeInteger(unsigned num, std::ofstream& ARFile) {
-  while (1) {
-    if (num < 0x80) { // done?
-      ARFile << (unsigned char)num;
-      return;
-    }
-
-    // Nope, we are bigger than a character, output the next 7 bits and set the
-    // high bit to say that there is more coming...
-    ARFile << (unsigned char)(0x80 | ((unsigned char)num & 0x7F));
-    num >>= 7;  // Shift out 7 bits now...
-  }
-}
-
-// Compute how many bytes are taken by a given VBR encoded value. This is needed
-// to pre-compute the size of the symbol table.
-static inline unsigned numVbrBytes(unsigned num) {
-
-  // Note that the following nested ifs are somewhat equivalent to a binary
-  // search. We split it in half by comparing against 2^14 first. This allows
-  // most reasonable values to be done in 2 comparisons instead of 1 for
-  // small ones and four for large ones. We expect this to access file offsets
-  // in the 2^10 to 2^24 range and symbol lengths in the 2^0 to 2^8 range,
-  // so this approach is reasonable.
-  if (num < 1<<14) {
-    if (num < 1<<7)
-      return 1;
-    else
-      return 2;
-  }
-  if (num < 1<<21)
-    return 3;
-
-  if (num < 1<<28)
-    return 4;
-  return 5; // anything >= 2^28 takes 5 bytes
-}
-
-// Create an empty archive.
-Archive* Archive::CreateEmpty(StringRef FilePath, LLVMContext& C) {
-  Archive* result = new Archive(FilePath, C);
-  return result;
-}
-
-// Fill the ArchiveMemberHeader with the information from a member. If
-// TruncateNames is true, names are flattened to 15 chars or less. The sz field
-// is provided here instead of coming from the mbr because the member might be
-// stored compressed and the compressed size is not the ArchiveMember's size.
-// Furthermore compressed files have negative size fields to identify them as
-// compressed.
-bool
-Archive::fillHeader(const ArchiveMember &mbr, ArchiveMemberHeader& hdr,
-                    int sz) const {
-
-  // Set the permissions mode, uid and gid
-  hdr.init();
-  char buffer[32];
-  sprintf(buffer, "%-8o", mbr.getMode());
-  memcpy(hdr.mode,buffer,8);
-  sprintf(buffer,  "%-6u", mbr.getUser());
-  memcpy(hdr.uid,buffer,6);
-  sprintf(buffer,  "%-6u", mbr.getGroup());
-  memcpy(hdr.gid,buffer,6);
-
-  // Set the last modification date
-  uint64_t secondsSinceEpoch = mbr.getModTime().toEpochTime();
-  sprintf(buffer,"%-12u", unsigned(secondsSinceEpoch));
-  memcpy(hdr.date,buffer,12);
-
-  std::string mbrPath = sys::path::filename(mbr.getPath());
-
-  // Set the name field in one of its various flavors.
-  bool writeLongName = false;
-  if (mbr.isStringTable()) {
-    memcpy(hdr.name,ARFILE_STRTAB_NAME,16);
-  } else if (mbr.isSVR4SymbolTable()) {
-    memcpy(hdr.name,ARFILE_SVR4_SYMTAB_NAME,16);
-  } else if (mbr.isBSD4SymbolTable()) {
-    memcpy(hdr.name,ARFILE_BSD4_SYMTAB_NAME,16);
-  } else if (mbrPath.length() < 16 && mbrPath.find('/') == std::string::npos) {
-    memcpy(hdr.name,mbrPath.c_str(),mbrPath.length());
-    hdr.name[mbrPath.length()] = '/';
-  } else {
-    std::string nm = "#1/";
-    nm += utostr(mbrPath.length());
-    memcpy(hdr.name,nm.data(),nm.length());
-    if (sz < 0)
-      sz -= mbrPath.length();
-    else
-      sz += mbrPath.length();
-    writeLongName = true;
-  }
-
-  // Set the size field
-  if (sz < 0) {
-    buffer[0] = '-';
-    sprintf(&buffer[1],"%-9u",(unsigned)-sz);
-  } else {
-    sprintf(buffer, "%-10u", (unsigned)sz);
-  }
-  memcpy(hdr.size,buffer,10);
-
-  return writeLongName;
-}
-
-// Insert a file into the archive before some other member. This also takes care
-// of extracting the necessary flags and information from the file.
-bool Archive::addFileBefore(StringRef filePath, iterator where,
-                            std::string *ErrMsg) {
-  if (!sys::fs::exists(filePath)) {
-    if (ErrMsg)
-      *ErrMsg = "Can not add a non-existent file to archive";
-    return true;
-  }
-
-  ArchiveMember* mbr = new ArchiveMember(this);
-
-  mbr->data = 0;
-  mbr->path = filePath;
-  sys::fs::file_status Status;
-  error_code EC = sys::fs::status(filePath, Status);
-  if (EC) {
-    delete mbr;
-    return true;
-  }
-  mbr->User = Status.getUser();
-  mbr->Group = Status.getGroup();
-  mbr->Mode = Status.permissions();
-  mbr->ModTime = Status.getLastModificationTime();
-  // FIXME: On posix this is a second stat.
-  EC =  sys::fs::file_size(filePath, mbr->Size);
-  if (EC) {
-    delete mbr;
-    return true;
-  }
-
-  unsigned flags = 0;
-  if (sys::path::filename(filePath).size() > 15)
-    flags |= ArchiveMember::HasLongFilenameFlag;
-
-  sys::fs::file_magic type;
-  if (sys::fs::identify_magic(mbr->path, type))
-    type = sys::fs::file_magic::unknown;
-  mbr->flags = flags;
-  members.insert(where,mbr);
-  return false;
-}
-
-// Write one member out to the file.
-bool
-Archive::writeMember(
-  const ArchiveMember& member,
-  raw_fd_ostream& ARFile,
-  std::string* ErrMsg
-) {
-
-  uint64_t filepos = ARFile.tell();
-  filepos -= 8;
-
-  // Get the data and its size either from the
-  // member's in-memory data or directly from the file.
-  size_t fSize = member.getSize();
-  const char *data = (const char*)member.getData();
-  MemoryBuffer *mFile = 0;
-  if (!data) {
-    OwningPtr<MemoryBuffer> File;
-    if (error_code ec = MemoryBuffer::getFile(member.getPath(), File)) {
-      if (ErrMsg)
-        *ErrMsg = ec.message();
-      return true;
-    }
-    mFile = File.take();
-    data = mFile->getBufferStart();
-    fSize = mFile->getBufferSize();
-  }
-
-  int hdrSize = fSize;
-
-  // Compute the fields of the header
-  ArchiveMemberHeader Hdr;
-  bool writeLongName = fillHeader(member,Hdr,hdrSize);
-
-  // Write header to archive file
-  ARFile.write((char*)&Hdr, sizeof(Hdr));
-
-  // Write the long filename if its long
-  if (writeLongName) {
-    StringRef Name = sys::path::filename(member.getPath());
-    ARFile.write(Name.data(), Name.size());
-  }
-
-  // Write the (possibly compressed) member's content to the file.
-  ARFile.write(data,fSize);
-
-  // Make sure the member is an even length
-  if ((ARFile.tell() & 1) == 1)
-    ARFile << ARFILE_PAD;
-
-  // Close the mapped file if it was opened
-  delete mFile;
-  return false;
-}
-
-// Write the entire archive to the file specified when the archive was created.
-// This writes to a temporary file first. Options are for creating a symbol
-// table, flattening the file names (no directories, 15 chars max) and
-// compressing each archive member.
-bool Archive::writeToDisk(std::string *ErrMsg) {
-  // Make sure they haven't opened up the file, not loaded it,
-  // but are now trying to write it which would wipe out the file.
-  if (members.empty() && mapfile && mapfile->getBufferSize() > 8) {
-    if (ErrMsg)
-      *ErrMsg = "Can't write an archive not opened for writing";
-    return true;
-  }
-
-  // Create a temporary file to store the archive in
-  int TmpArchiveFD;
-  SmallString<128> TmpArchive;
-  error_code EC = sys::fs::createUniqueFile(
-      archPath + ".temp-archive-%%%%%%%.a", TmpArchiveFD, TmpArchive);
-  if (EC)
-    return true;
-
-  // Make sure the temporary gets removed if we crash
-  sys::RemoveFileOnSignal(TmpArchive);
-
-  // Create archive file for output.
-  raw_fd_ostream ArchiveFile(TmpArchiveFD, true);
-
-  // Write magic string to archive.
-  ArchiveFile << ARFILE_MAGIC;
-
-  // Loop over all member files, and write them out. Note that this also
-  // builds the symbol table, symTab.
-  for (MembersList::iterator I = begin(), E = end(); I != E; ++I) {
-    if (writeMember(*I, ArchiveFile, ErrMsg)) {
-      sys::fs::remove(Twine(TmpArchive));
-      ArchiveFile.close();
-      return true;
-    }
-  }
-
-  // Close archive file.
-  ArchiveFile.close();
-
-  // Before we replace the actual archive, we need to forget all the
-  // members, since they point to data in that old archive. We need to do
-  // this because we cannot replace an open file on Windows.
-  cleanUpMemory();
-
-  if (sys::fs::rename(Twine(TmpArchive), archPath)) {
-    *ErrMsg = EC.message();
-    return true;
-  }
-
-  return false;
-}