Re: [PATCH] PR binutils/14625: Enable 64-bit archives in ar and ranlib

["H.J. Lu" <hjl.tools@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 2180 bytes --]

On Mon, May 23, 2016 at 2:42 AM, Alan Modra <amodra@gmail.com> wrote:
> On Fri, May 20, 2016 at 05:10:02AM -0700, H.J. Lu wrote:
>> Since existing ld and gold support the 64-bit (MIPS) ELF archives, we
>> can use the 64-bit (MIPS) ELF archives as 64-bit archives.  Since the
>> plugin target is used to create archive in plugin-enabled ar, we need
>> a way to enable 64-bit archives in the plugin target.  This patch adds
>> --enable-64-bit-archive to bfd to enable 64-bit archives in ar and
>> ranlib.  Since both 64-bit MIPS and s390 ELF targets currently use
>> 64-bit archives, all Linux linkers with 64-bit BFD support both 32-bit
>> and 64-bit archives, 64-bit archives are enabled by default for them.
>
> Hmm, isn't it true that archive64.c is compiled in for any 64-bit
> target?  I also don't see anything ELF specific in archive64.c.

That is correct.

>> +  # Since all Linux linkers support both 32-bit and 64-bit archives,
>> +  # it is safe to enable 64-bit archives for Linux targets with 64-bit
>> +  # bfd_vma.
>> +  case "${target}${want64}" in
>> +    *linux*true)
>> +      want_64_bit_archive=true
>> +      ;;
>> +  esac
>> +fi
>
> So the above could just set want_64_bit_archive based on want64,
> ignoring target, except that doing so might result in archives that
> aren't recognized by native tools.  How about instead of this
> configure option, changing _bfd_compute_and_write_armap to choose the
> archive64.c write_armap whenever the archive size is larger than 2G?

The limit is 4GB, not 2GB.  The limit is the offset of an archive member,
not the size of archive.  We can have an archive > 4GB with archive
member offsets < 4GB.

> I think that might just work automatically.
>
> The rest of the patch looks reasonable except that you missed changing
> elf64-ia64-vms.c, and I think the libbfd-in.h defines would be better

Since elf64-ia64-vms.c uses _bfd_vms_lib_write_armap which is defined as
NULL, i prefer to leave it unchanged.

> with the coff defines substituted.  eg. _bfd_slurp_extended_name_table
> rather than _bfd_archive_coff_slurp_extended_name_table.
>

Good point.  Here is the updated patch.  OK for master?

Thanks.


-- 
H.J.

[-- Attachment #2: 0001-Enable-64-bit-archives-in-ar-and-ranlib.patch --]
[-- Type: text/x-patch, Size: 18570 bytes --]

From b7fa03023ed7818a775a4250ae333a7845ec7918 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 19 May 2016 13:34:11 -0700
Subject: [PATCH] Enable 64-bit archives in ar and ranlib

Since existing ld and gold support the 64-bit (MIPS) ELF archives, we
can use the 64-bit (MIPS) ELF archives as 64-bit archives.  Since the
plugin target is used to create archive in plugin-enabled ar, we need
a way to enable 64-bit archives in the plugin target.  This patch adds
--enable-64-bit-archive to bfd to enable 64-bit archives in ar and
ranlib.  Since both 64-bit MIPS and s390 ELF targets currently use
64-bit archives, all Linux linkers with 64-bit BFD support both 32-bit
and 64-bit archives, 64-bit archives are enabled by default for them.

Tested on Linux/x86 and Linux/x86-64 with existing ld and gold.

bfd/

	PR binutils/14625
	* archive.c (bfd_slurp_armap): Replace
	bfd_elf64_archive_slurp_armap with
	_bfd_archive_64_bit_slurp_armap.
	* archive64.c (bfd_elf64_archive_slurp_armap): Renamed to ...
	(_bfd_archive_64_bit_slurp_armap): This.
	(bfd_elf64_archive_write_armap): Renamed to ...
	(_bfd_archive_64_bit_write_armap): This.
	* configure.ac: Add --enable-64-bit-archive.
	(want_64_bit_archive): New.  Set to true by default for 64-bit
	MIPS and s390 ELF targets as well as Linux targets with 64-bit
	bfd_vma.
	(USE_64_BIT_ARCHIVE): New AC_DEFINE.
	* config.in: Regenerated.
	* configure: Likewise.
	* elf64-mips.c (bfd_elf64_archive_functions): Removed.
	(bfd_elf64_archive_slurp_armap): Likewise.
	(bfd_elf64_archive_write_armap): Likewise.
	(bfd_elf64_archive_slurp_extended_name_table): Likewise.
	(bfd_elf64_archive_construct_extended_name_table): Likewise.
	(bfd_elf64_archive_truncate_arname): Likewise.
	(bfd_elf64_archive_read_ar_hdr): Likewise.
	(bfd_elf64_archive_write_ar_hdr): Likewise.
	(bfd_elf64_archive_openr_next_archived_file): Likewise.
	(bfd_elf64_archive_get_elt_at_index): Likewise.
	(bfd_elf64_archive_generic_stat_arch_elt): Likewise.
	(bfd_elf64_archive_update_armap_timestamp): Likewise.
	* elf64-s390.c (bfd_elf64_archive_functions): Removed.
	(bfd_elf64_archive_slurp_armap): Likewise.
	(bfd_elf64_archive_write_armap): Likewise.
	(bfd_elf64_archive_slurp_extended_name_table): Likewise.
	(bfd_elf64_archive_construct_extended_name_table): Likewise.
	(bfd_elf64_archive_truncate_arname): Likewise.
	(bfd_elf64_archive_read_ar_hdr): Likewise.
	(bfd_elf64_archive_write_ar_hdr): Likewise.
	(bfd_elf64_archive_openr_next_archived_file): Likewise.
	(bfd_elf64_archive_get_elt_at_index): Likewise.
	(bfd_elf64_archive_generic_stat_arch_elt): Likewise.
	(bfd_elf64_archive_update_armap_timestamp): Likewise.
	* elfxx-target.h (TARGET_BIG_SYM): Use _bfd_archive_64_bit on
	BFD_JUMP_TABLE_ARCHIVE if USE_64_BIT_ARCHIVE is defined and
	bfd_elfNN_archive_functions isn't defined.
	(TARGET_LITTLE_SYM): Likewise.
	* libbfd-in.h (_bfd_archive_64_bit_slurp_armap): New prototype.
	(_bfd_archive_64_bit_write_armap): Likewise.
	(_bfd_archive_64_bit_slurp_extended_name_table): New macro.
	(_bfd_archive_64_bit_construct_extended_name_table): Likewise.
	(_bfd_archive_64_bit_truncate_arname): Likewise.
	(_bfd_archive_64_bit_read_ar_hdr): Likewise.
	(_bfd_archive_64_bit_write_ar_hdr): Likewise.
	(_bfd_archive_64_bit_openr_next_archived_file): Likewise.
	(_bfd_archive_64_bit_get_elt_at_index): Likewise.
	(_bfd_archive_64_bit_generic_stat_arch_elt): Likewise.
	(_bfd_archive_64_bit_update_armap_timestamp): Likewise.
	* libbfd.h: Regenerated.
	* plugin.c (plugin_vec): Use _bfd_archive_64_bit on
	BFD_JUMP_TABLE_ARCHIVE if USE_64_BIT_ARCHIVE is defined.

binutils/

	PR binutils/14625
	* NEWS: Mention --enable-64-bit-archive.
---
 bfd/archive.c      |  5 ++---
 bfd/archive64.c    | 21 +++++++++------------
 bfd/config.in      |  3 +++
 bfd/configure      | 45 +++++++++++++++++++++++++++++++++++++++++++--
 bfd/configure.ac   | 36 ++++++++++++++++++++++++++++++++++++
 bfd/elf64-mips.c   | 23 -----------------------
 bfd/elf64-s390.c   | 15 ---------------
 bfd/elfxx-target.h |  4 ++++
 bfd/libbfd-in.h    | 23 +++++++++++++++++++++++
 bfd/libbfd.h       | 23 +++++++++++++++++++++++
 bfd/plugin.c       |  4 ++++
 binutils/NEWS      |  3 +++
 12 files changed, 150 insertions(+), 55 deletions(-)

diff --git a/bfd/archive.c b/bfd/archive.c
index 53e295e..086f7c3 100644
--- a/bfd/archive.c
+++ b/bfd/archive.c
@@ -1144,10 +1144,9 @@ bfd_slurp_armap (bfd *abfd)
     return do_slurp_coff_armap (abfd);
   else if (CONST_STRNEQ (nextname, "/SYM64/         "))
     {
-      /* 64bit ELF (Irix 6) archive.  */
+      /* 64bit (Irix 6) archive.  */
 #ifdef BFD64
-      extern bfd_boolean bfd_elf64_archive_slurp_armap (bfd *);
-      return bfd_elf64_archive_slurp_armap (abfd);
+      return _bfd_archive_64_bit_slurp_armap (abfd);
 #else
       bfd_set_error (bfd_error_wrong_format);
       return FALSE;
diff --git a/bfd/archive64.c b/bfd/archive64.c
index 3192f40..be1ac7c 100644
--- a/bfd/archive64.c
+++ b/bfd/archive64.c
@@ -1,4 +1,4 @@
-/* Support for 64-bit ELF archives.
+/* Support for 64-bit archives.
    Copyright (C) 1996-2016 Free Software Foundation, Inc.
    Ian Lance Taylor, Cygnus Support
    Linker support added by Mark Mitchell, CodeSourcery, LLC.
@@ -21,7 +21,8 @@
    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
    MA 02110-1301, USA.  */
 
-/* This file supports the 64-bit (MIPS) ELF archives.  */
+/* This file supports the 64-bit archives.  We use the same format as
+   the 64-bit (MIPS) ELF archives.  */
 
 #include "sysdep.h"
 #include "bfd.h"
@@ -31,14 +32,10 @@
 /* Irix 6 defines a 64bit archive map format, so that they can
    have archives more than 4 GB in size.  */
 
-bfd_boolean bfd_elf64_archive_slurp_armap (bfd *);
-bfd_boolean bfd_elf64_archive_write_armap
-  (bfd *, unsigned int, struct orl *, unsigned int, int);
-
 /* Read an Irix 6 armap.  */
 
 bfd_boolean
-bfd_elf64_archive_slurp_armap (bfd *abfd)
+_bfd_archive_64_bit_slurp_armap (bfd *abfd)
 {
   struct artdata *ardata = bfd_ardata (abfd);
   char nextname[17];
@@ -150,11 +147,11 @@ release_symdefs:
    linker crashes.  */
 
 bfd_boolean
-bfd_elf64_archive_write_armap (bfd *arch,
-			       unsigned int elength,
-			       struct orl *map,
-			       unsigned int symbol_count,
-			       int stridx)
+_bfd_archive_64_bit_write_armap (bfd *arch,
+				 unsigned int elength,
+				 struct orl *map,
+				 unsigned int symbol_count,
+				 int stridx)
 {
   unsigned int ranlibsize = (symbol_count * 8) + 8;
   unsigned int stringsize = stridx;
diff --git a/bfd/config.in b/bfd/config.in
index cffadbb..341afae 100644
--- a/bfd/config.in
+++ b/bfd/config.in
@@ -337,6 +337,9 @@
 /* Name of host specific header file to include in trad-core.c. */
 #undef TRAD_HEADER
 
+/* Define if we should use 64-bit archives. */
+#undef USE_64_BIT_ARCHIVE
+
 /* Use b modifier when opening binary files? */
 #undef USE_BINARY_FOPEN
 
diff --git a/bfd/configure b/bfd/configure
index f8617b9..61af105 100755
--- a/bfd/configure
+++ b/bfd/configure
@@ -789,6 +789,7 @@ enable_plugins
 enable_largefile
 enable_64_bit_bfd
 enable_targets
+enable_64_bit_archive
 with_mmap
 enable_secureplt
 enable_leading_mingw64_underscores
@@ -1442,6 +1443,7 @@ Optional Features:
   --disable-largefile     omit support for large files
   --enable-64-bit-bfd     64-bit support (on hosts with narrower word sizes)
   --enable-targets        alternative target configurations
+  --enable-64-bit-archive use 64-bit archives
   --enable-secureplt      Default to creating read-only plt entries
   --enable-leading-mingw64-underscores
                           Enable leading underscores on 64 bit mingw targets
@@ -11425,7 +11427,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11428 "configure"
+#line 11430 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11531,7 +11533,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11534 "configure"
+#line 11536 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12129,6 +12131,19 @@ if test "${enable_targets+set}" = set; then :
 esac
 fi
 
+# Since the plugin target is used to create archive in plugin-enabled
+# ar, we need a way to enable 64-bit archives in the plugin target.
+# Check whether --enable-64_bit_archive was given.
+if test "${enable_64_bit_archive+set}" = set; then :
+  enableval=$enable_64_bit_archive; case "${enableval}" in
+  yes)  want_64_bit_archive=true  ;;
+  no)   want_64_bit_archive=false ;;
+  *)    as_fn_error "bad value ${enableval} for 64-bit-archive option" "$LINENO" 5 ;;
+esac
+else
+  want_64_bit_archive=unset
+fi
+
 
 # Check whether --with-mmap was given.
 if test "${with_mmap+set}" = set; then :
@@ -14596,6 +14611,32 @@ else	# all_targets is true
     selarchs=`echo $selarchs | sed -e 's/^/\&/' -e 's/ \(.\)/,\&\1/g'`
 fi	# all_targets is true
 
+if test "x$want_64_bit_archive" = xunset; then
+  # 64-bit MIPS and s390 ELF targets use 64-bit archives.
+  case "${bfd_backends}" in
+    *elf64-mips* | *elf64-s390*)
+      want_64_bit_archive=true
+      ;;
+  esac
+
+  # Since all Linux linkers support both 32-bit and 64-bit archives,
+  # it is safe to enable 64-bit archives for Linux targets with 64-bit
+  # bfd_vma.
+  case "${target}${want64}" in
+    *linux*true)
+      want_64_bit_archive=true
+      ;;
+  esac
+fi
+
+# 64-bit archives need a 64-bit bfd_vma.
+if test "x$want_64_bit_archive" = xtrue; then
+  want64=true
+
+$as_echo "#define USE_64_BIT_ARCHIVE 1" >>confdefs.h
+
+fi
+
 case ${host64}-${target64}-${want64} in
   *true*)
     wordsize=64
diff --git a/bfd/configure.ac b/bfd/configure.ac
index f57d4d7..d0a0888 100644
--- a/bfd/configure.ac
+++ b/bfd/configure.ac
@@ -68,6 +68,17 @@ AC_ARG_ENABLE(targets,
   *)        enable_targets=$enableval ;;
 esac])dnl
 
+# Since the plugin target is used to create archive in plugin-enabled
+# ar, we need a way to enable 64-bit archives in the plugin target.
+AC_ARG_ENABLE(64_bit_archive,
+	      AS_HELP_STRING([--enable-64-bit-archive],
+	      [use 64-bit archives]),
+[case "${enableval}" in
+  yes)  want_64_bit_archive=true  ;;
+  no)   want_64_bit_archive=false ;;
+  *)    AC_MSG_ERROR(bad value ${enableval} for 64-bit-archive option) ;;
+esac],[want_64_bit_archive=unset])dnl
+
 AC_ARG_WITH(mmap,
 [  --with-mmap             try using mmap for BFD input files if available],
 [case "${withval}" in
@@ -775,6 +786,31 @@ else	# all_targets is true
     selarchs=`echo $selarchs | sed -e 's/^/\&/' -e 's/ \(.\)/,\&\1/g'`
 fi	# all_targets is true
 
+if test "x$want_64_bit_archive" = xunset; then
+  # 64-bit MIPS and s390 ELF targets use 64-bit archives.
+  case "${bfd_backends}" in
+    *elf64-mips* | *elf64-s390*)
+      want_64_bit_archive=true
+      ;;
+  esac
+
+  # Since all Linux linkers support both 32-bit and 64-bit archives,
+  # it is safe to enable 64-bit archives for Linux targets with 64-bit
+  # bfd_vma.
+  case "${target}${want64}" in
+    *linux*true)
+      want_64_bit_archive=true
+      ;;
+  esac
+fi
+
+# 64-bit archives need a 64-bit bfd_vma.
+if test "x$want_64_bit_archive" = xtrue; then
+  want64=true
+  AC_DEFINE(USE_64_BIT_ARCHIVE, 1,
+    [Define if we should use 64-bit archives.])
+fi
+
 case ${host64}-${target64}-${want64} in
   *true*)
     wordsize=64
diff --git a/bfd/elf64-mips.c b/bfd/elf64-mips.c
index 6bedebc..34144f0 100644
--- a/bfd/elf64-mips.c
+++ b/bfd/elf64-mips.c
@@ -4478,29 +4478,6 @@ const struct elf_size_info mips_elf64_size_info =
 #define bfd_elf64_bfd_relax_section     _bfd_mips_relax_section
 #define bfd_elf64_mkobject		_bfd_mips_elf_mkobject
 
-/* MIPS ELF64 archive functions.  */
-#define bfd_elf64_archive_functions
-extern bfd_boolean bfd_elf64_archive_slurp_armap
-  (bfd *);
-extern bfd_boolean bfd_elf64_archive_write_armap
-  (bfd *, unsigned int, struct orl *, unsigned int, int);
-#define bfd_elf64_archive_slurp_extended_name_table \
-			_bfd_archive_coff_slurp_extended_name_table
-#define bfd_elf64_archive_construct_extended_name_table \
-			_bfd_archive_coff_construct_extended_name_table
-#define bfd_elf64_archive_truncate_arname \
-			_bfd_archive_coff_truncate_arname
-#define bfd_elf64_archive_read_ar_hdr	_bfd_archive_coff_read_ar_hdr
-#define bfd_elf64_archive_write_ar_hdr	_bfd_archive_coff_write_ar_hdr
-#define bfd_elf64_archive_openr_next_archived_file \
-			_bfd_archive_coff_openr_next_archived_file
-#define bfd_elf64_archive_get_elt_at_index \
-			_bfd_archive_coff_get_elt_at_index
-#define bfd_elf64_archive_generic_stat_arch_elt \
-			_bfd_archive_coff_generic_stat_arch_elt
-#define bfd_elf64_archive_update_armap_timestamp \
-			_bfd_archive_coff_update_armap_timestamp
-
 /* The SGI style (n)64 NewABI.  */
 #define TARGET_LITTLE_SYM		mips_elf64_le_vec
 #define TARGET_LITTLE_NAME		"elf64-littlemips"
diff --git a/bfd/elf64-s390.c b/bfd/elf64-s390.c
index b085169..3950939 100644
--- a/bfd/elf64-s390.c
+++ b/bfd/elf64-s390.c
@@ -3955,19 +3955,4 @@ const struct elf_size_info s390_elf64_size_info =
 #define bfd_elf64_mkobject		elf_s390_mkobject
 #define elf_backend_object_p		elf_s390_object_p
 
-/* Enable ELF64 archive functions.  */
-#define bfd_elf64_archive_functions
-extern bfd_boolean bfd_elf64_archive_slurp_armap (bfd *);
-extern bfd_boolean bfd_elf64_archive_write_armap (bfd *, unsigned int, struct orl *, unsigned int, int);
-
-#define bfd_elf64_archive_slurp_extended_name_table 	_bfd_archive_coff_slurp_extended_name_table
-#define bfd_elf64_archive_construct_extended_name_table _bfd_archive_coff_construct_extended_name_table
-#define bfd_elf64_archive_truncate_arname 		_bfd_archive_coff_truncate_arname
-#define bfd_elf64_archive_read_ar_hdr			_bfd_archive_coff_read_ar_hdr
-#define bfd_elf64_archive_write_ar_hdr			_bfd_archive_coff_write_ar_hdr
-#define bfd_elf64_archive_openr_next_archived_file 	_bfd_archive_coff_openr_next_archived_file
-#define bfd_elf64_archive_get_elt_at_index 		_bfd_archive_coff_get_elt_at_index
-#define bfd_elf64_archive_generic_stat_arch_elt 	_bfd_archive_coff_generic_stat_arch_elt
-#define bfd_elf64_archive_update_armap_timestamp 	_bfd_archive_coff_update_armap_timestamp
-
 #include "elf64-target.h"
diff --git a/bfd/elfxx-target.h b/bfd/elfxx-target.h
index 0dc4f75..97aa5e6 100644
--- a/bfd/elfxx-target.h
+++ b/bfd/elfxx-target.h
@@ -926,6 +926,8 @@ const bfd_target TARGET_BIG_SYM =
   BFD_JUMP_TABLE_CORE (bfd_elfNN),
 #ifdef bfd_elfNN_archive_functions
   BFD_JUMP_TABLE_ARCHIVE (bfd_elfNN_archive),
+#elif defined USE_64_BIT_ARCHIVE
+  BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
 #else
   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 #endif
@@ -1025,6 +1027,8 @@ const bfd_target TARGET_LITTLE_SYM =
   BFD_JUMP_TABLE_CORE (bfd_elfNN),
 #ifdef bfd_elfNN_archive_functions
   BFD_JUMP_TABLE_ARCHIVE (bfd_elfNN_archive),
+#elif defined USE_64_BIT_ARCHIVE
+  BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
 #else
   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 #endif
diff --git a/bfd/libbfd-in.h b/bfd/libbfd-in.h
index 5f28863..8644d8d 100644
--- a/bfd/libbfd-in.h
+++ b/bfd/libbfd-in.h
@@ -149,6 +149,29 @@ bfd_boolean bfd_slurp_bsd_armap_f2
   (bfd *abfd);
 #define bfd_slurp_bsd_armap bfd_slurp_armap
 #define bfd_slurp_coff_armap bfd_slurp_armap
+bfd_boolean _bfd_archive_64_bit_slurp_armap
+  (bfd *);
+bfd_boolean _bfd_archive_64_bit_write_armap
+  (bfd *, unsigned int, struct orl *, unsigned int, int);
+#define _bfd_archive_64_bit_slurp_extended_name_table \
+  _bfd_slurp_extended_name_table
+#define _bfd_archive_64_bit_construct_extended_name_table \
+  _bfd_archive_coff_construct_extended_name_table
+#define _bfd_archive_64_bit_truncate_arname \
+  bfd_dont_truncate_arname
+#define _bfd_archive_64_bit_read_ar_hdr \
+  _bfd_generic_read_ar_hdr
+#define _bfd_archive_64_bit_write_ar_hdr \
+  _bfd_generic_write_ar_hdr
+#define _bfd_archive_64_bit_openr_next_archived_file \
+  bfd_generic_openr_next_archived_file
+#define _bfd_archive_64_bit_get_elt_at_index \
+  _bfd_generic_get_elt_at_index
+#define _bfd_archive_64_bit_generic_stat_arch_elt \
+  bfd_generic_stat_arch_elt
+#define _bfd_archive_64_bit_update_armap_timestamp \
+  bfd_true
+
 bfd_boolean _bfd_slurp_extended_name_table
   (bfd *abfd);
 extern bfd_boolean _bfd_construct_extended_name_table
diff --git a/bfd/libbfd.h b/bfd/libbfd.h
index 33490c0..bf17f43 100644
--- a/bfd/libbfd.h
+++ b/bfd/libbfd.h
@@ -154,6 +154,29 @@ bfd_boolean bfd_slurp_bsd_armap_f2
   (bfd *abfd);
 #define bfd_slurp_bsd_armap bfd_slurp_armap
 #define bfd_slurp_coff_armap bfd_slurp_armap
+bfd_boolean _bfd_archive_64_bit_slurp_armap
+  (bfd *);
+bfd_boolean _bfd_archive_64_bit_write_armap
+  (bfd *, unsigned int, struct orl *, unsigned int, int);
+#define _bfd_archive_64_bit_slurp_extended_name_table \
+  _bfd_slurp_extended_name_table
+#define _bfd_archive_64_bit_construct_extended_name_table \
+  _bfd_archive_coff_construct_extended_name_table
+#define _bfd_archive_64_bit_truncate_arname \
+  bfd_dont_truncate_arname
+#define _bfd_archive_64_bit_read_ar_hdr \
+  _bfd_generic_read_ar_hdr
+#define _bfd_archive_64_bit_write_ar_hdr \
+  _bfd_generic_write_ar_hdr
+#define _bfd_archive_64_bit_openr_next_archived_file \
+  bfd_generic_openr_next_archived_file
+#define _bfd_archive_64_bit_get_elt_at_index \
+  _bfd_generic_get_elt_at_index
+#define _bfd_archive_64_bit_generic_stat_arch_elt \
+  bfd_generic_stat_arch_elt
+#define _bfd_archive_64_bit_update_armap_timestamp \
+  bfd_true
+
 bfd_boolean _bfd_slurp_extended_name_table
   (bfd *abfd);
 extern bfd_boolean _bfd_construct_extended_name_table
diff --git a/bfd/plugin.c b/bfd/plugin.c
index fd7bac0..c81a267 100644
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -597,7 +597,11 @@ const bfd_target plugin_vec =
   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
   BFD_JUMP_TABLE_COPY (bfd_plugin),
   BFD_JUMP_TABLE_CORE (bfd_plugin),
+#ifdef USE_64_BIT_ARCHIVE
+  BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
+#else
   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
+#endif
   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
   BFD_JUMP_TABLE_WRITE (bfd_plugin),
diff --git a/binutils/NEWS b/binutils/NEWS
index 712604b..d119c1e 100644
--- a/binutils/NEWS
+++ b/binutils/NEWS
@@ -1,5 +1,8 @@
 -*- text -*-
 
+* Add a configure option, --enable-64-bit-archive, to enable 64-bit
+  archives in ar and ranlib.
+
 * Add --elf-stt-common= option to objcopy for ELF targets to control
   whether to convert common symbols to the STT_COMMON type.
 
-- 
2.5.5