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.

llvm-svn: 186197

1 files changed, 0 insertions, 317 deletions

diff --git a/llvm/tools/llvm-ar/ArchiveReader.cpp b/llvm/tools/llvm-ar/ArchiveReader.cpp
deleted file mode 100644
index a041cb881c3..00000000000
--- a/llvm/tools/llvm-ar/ArchiveReader.cpp
+++ /dev/null
@@ -1,317 +0,0 @@
-//===-- ArchiveReader.cpp - Read LLVM archive files -------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// 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 bitcode.
-//
-//===----------------------------------------------------------------------===//
-
-#include "Archive.h"
-#include "ArchiveInternals.h"
-#include "llvm/ADT/OwningPtr.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/Bitcode/ReaderWriter.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Support/FileSystem.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include <cstdio>
-#include <cstdlib>
-using namespace llvm;
-
-/// Read a variable-bit-rate encoded unsigned integer
-static inline unsigned readInteger(const char*&At, const char*End) {
-  unsigned Shift = 0;
-  unsigned Result = 0;
-
-  do {
-    if (At == End)
-      return Result;
-    Result |= (unsigned)((*At++) & 0x7F) << Shift;
-    Shift += 7;
-  } while (At[-1] & 0x80);
-  return Result;
-}
-
-// This member parses an ArchiveMemberHeader that is presumed to be pointed to
-// by At. The At pointer is updated to the byte just after the header, which
-// can be variable in size.
-ArchiveMember*
-Archive::parseMemberHeader(const char*& At, const char* End, std::string* error)
-{
-  if (At + sizeof(ArchiveMemberHeader) >= End) {
-    if (error)
-      *error = "Unexpected end of file";
-    return 0;
-  }
-
-  // Cast archive member header
-  const ArchiveMemberHeader* Hdr = (const ArchiveMemberHeader*)At;
-  At += sizeof(ArchiveMemberHeader);
-
-  int flags = 0;
-  int MemberSize = atoi(Hdr->size);
-  assert(MemberSize >= 0);
-
-  // Check the size of the member for sanity
-  if (At + MemberSize > End) {
-    if (error)
-      *error = "invalid member length in archive file";
-    return 0;
-  }
-
-  // Check the member signature
-  if (!Hdr->checkSignature()) {
-    if (error)
-      *error = "invalid file member signature";
-    return 0;
-  }
-
-  // Convert and check the member name
-  // The empty name ( '/' and 15 blanks) is for a foreign (non-LLVM) symbol
-  // table. The special name "//" and 14 blanks is for a string table, used
-  // for long file names. This library doesn't generate either of those but
-  // it will accept them. If the name starts with #1/ and the remainder is
-  // digits, then those digits specify the length of the name that is
-  // stored immediately following the header. Anything else is a regular, short
-  // filename that is terminated with a '/' and blanks.
-
-  std::string pathname;
-  switch (Hdr->name[0]) {
-    case '#':
-      if (Hdr->name[1] == '1' && Hdr->name[2] == '/') {
-        if (isdigit(Hdr->name[3])) {
-          unsigned len = atoi(&Hdr->name[3]);
-          const char *nulp = (const char *)memchr(At, '\0', len);
-          pathname.assign(At, nulp != 0 ? (uintptr_t)(nulp - At) : len);
-          At += len;
-          MemberSize -= len;
-          flags |= ArchiveMember::HasLongFilenameFlag;
-        } else {
-          if (error)
-            *error = "invalid long filename";
-          return 0;
-        }
-      }
-      break;
-    case '/':
-      if (Hdr->name[1]== '/') {
-        if (0 == memcmp(Hdr->name, ARFILE_STRTAB_NAME, 16)) {
-          pathname.assign(ARFILE_STRTAB_NAME);
-          flags |= ArchiveMember::StringTableFlag;
-        } else {
-          if (error)
-            *error = "invalid string table name";
-          return 0;
-        }
-      } else if (Hdr->name[1] == ' ') {
-        if (0 == memcmp(Hdr->name, ARFILE_SVR4_SYMTAB_NAME, 16)) {
-          pathname.assign(ARFILE_SVR4_SYMTAB_NAME);
-          flags |= ArchiveMember::SVR4SymbolTableFlag;
-        } else {
-          if (error)
-            *error = "invalid SVR4 symbol table name";
-          return 0;
-        }
-      } else if (isdigit(Hdr->name[1])) {
-        unsigned index = atoi(&Hdr->name[1]);
-        if (index < strtab.length()) {
-          const char* namep = strtab.c_str() + index;
-          const char* endp = strtab.c_str() + strtab.length();
-          const char* p = namep;
-          const char* last_p = p;
-          while (p < endp) {
-            if (*p == '\n' && *last_p == '/') {
-              pathname.assign(namep, last_p - namep);
-              flags |= ArchiveMember::HasLongFilenameFlag;
-              break;
-            }
-            last_p = p;
-            p++;
-          }
-          if (p >= endp) {
-            if (error)
-              *error = "missing name terminator in string table";
-            return 0;
-          }
-        } else {
-          if (error)
-            *error = "name index beyond string table";
-          return 0;
-        }
-      }
-      break;
-    case '_':
-      if (Hdr->name[1] == '_' &&
-          (0 == memcmp(Hdr->name, ARFILE_BSD4_SYMTAB_NAME, 16))) {
-        pathname.assign(ARFILE_BSD4_SYMTAB_NAME);
-        flags |= ArchiveMember::BSD4SymbolTableFlag;
-        break;
-      }
-      /* FALL THROUGH */
-
-    default:
-      const char* slash = (const char*) memchr(Hdr->name, '/', 16);
-      if (slash == 0)
-        slash = Hdr->name + 16;
-      pathname.assign(Hdr->name, slash - Hdr->name);
-      break;
-  }
-
-  // Instantiate the ArchiveMember to be filled
-  ArchiveMember* member = new ArchiveMember(this);
-
-  // Fill in fields of the ArchiveMember
-  member->parent = this;
-  member->path = pathname;
-  member->Size = MemberSize;
-  member->ModTime.fromEpochTime(atoi(Hdr->date));
-  unsigned int mode;
-  sscanf(Hdr->mode, "%o", &mode);
-  member->Mode = mode;
-  member->User = atoi(Hdr->uid);
-  member->Group = atoi(Hdr->gid);
-  member->flags = flags;
-  member->data = At;
-
-  return member;
-}
-
-bool
-Archive::checkSignature(std::string* error) {
-  // Check the magic string at file's header
-  if (mapfile->getBufferSize() < 8 || memcmp(base, ARFILE_MAGIC, 8)) {
-    if (error)
-      *error = "invalid signature for an archive file";
-    return false;
-  }
-  return true;
-}
-
-// This function loads the entire archive and fully populates its ilist with
-// the members of the archive file. This is typically used in preparation for
-// editing the contents of the archive.
-bool
-Archive::loadArchive(std::string* error) {
-
-  // Set up parsing
-  members.clear();
-  const char *At = base;
-  const char *End = mapfile->getBufferEnd();
-
-  if (!checkSignature(error))
-    return false;
-
-  At += 8;  // Skip the magic string.
-
-  bool foundFirstFile = false;
-  while (At < End) {
-    // parse the member header
-    const char* Save = At;
-    OwningPtr<ArchiveMember> mbr(parseMemberHeader(At, End, error));
-    if (!mbr)
-      return false;
-
-    // check if this is the foreign symbol table
-    if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
-      At += mbr->getSize();
-      if ((intptr_t(At) & 1) == 1)
-        At++;
-    } else if (mbr->isStringTable()) {
-      // Simply suck the entire string table into a string
-      // variable. This will be used to get the names of the
-      // members that use the "/ddd" format for their names
-      // (SVR4 style long names).
-      strtab.assign(At, mbr->getSize());
-      At += mbr->getSize();
-      if ((intptr_t(At) & 1) == 1)
-        At++;
-    } else {
-      // This is just a regular file. If its the first one, save its offset.
-      // Otherwise just push it on the list and move on to the next file.
-      if (!foundFirstFile) {
-        firstFileOffset = Save - base;
-        foundFirstFile = true;
-      }
-      At += mbr->getSize();
-      members.push_back(mbr.take());
-      if ((intptr_t(At) & 1) == 1)
-        At++;
-    }
-  }
-  return true;
-}
-
-// Open and completely load the archive file.
-Archive*
-Archive::OpenAndLoad(StringRef File, LLVMContext& C,
-                     std::string* ErrorMessage) {
-  OwningPtr<Archive> result(new Archive(File, C));
-  if (result->mapToMemory(ErrorMessage))
-    return NULL;
-  if (!result->loadArchive(ErrorMessage))
-    return NULL;
-  return result.take();
-}
-
-// Load just the symbol table from the archive file
-bool
-Archive::loadSymbolTable(std::string* ErrorMsg) {
-
-  // Set up parsing
-  members.clear();
-  const char *At = base;
-  const char *End = mapfile->getBufferEnd();
-
-  // Make sure we're dealing with an archive
-  if (!checkSignature(ErrorMsg))
-    return false;
-
-  At += 8; // Skip signature
-
-  // Parse the first file member header
-  const char* FirstFile = At;
-  OwningPtr<ArchiveMember> mbr(parseMemberHeader(At, End, ErrorMsg));
-  if (!mbr)
-    return false;
-
-  if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
-    // Skip the foreign symbol table, we don't do anything with it
-    At += mbr->getSize();
-    if ((intptr_t(At) & 1) == 1)
-      At++;
-
-    // Read the next one
-    FirstFile = At;
-    mbr.reset(parseMemberHeader(At, End, ErrorMsg));
-    if (!mbr)
-      return false;
-  }
-
-  if (mbr->isStringTable()) {
-    // Process the string table entry
-    strtab.assign((const char*)mbr->getData(), mbr->getSize());
-    At += mbr->getSize();
-    if ((intptr_t(At) & 1) == 1)
-      At++;
-
-    // Get the next one
-    FirstFile = At;
-    mbr.reset(parseMemberHeader(At, End, ErrorMsg));
-    if (!mbr)
-      return false;
-  }
-
-  // There's no symbol table in the file. We have to rebuild it from scratch
-  // because the intent of this method is to get the symbol table loaded so
-  // it can be searched efficiently.
-  // Add the member to the members list
-  members.push_back(mbr.take());
-
-  firstFileOffset = FirstFile - base;
-  return true;
-}