PATCH: Add support for "thin" archives

[Nick Clifton]

Hi Cary,

> The attached patch adds support to bfd and binutils for a new kind of
> archive I call "thin" archives.

Thanks very much for submitting this patch.


I do have one request however - please could you supply a patch to 
readelf to allow it to process thin archives in the same way that it can 
currently process ordinary archives.  (Including supporting the 
--archive-index option).

> 2008-03-19  Cary Coutant <ccoutant@google.com>
> 
>         Add support for thin archives.
> 	* bfd/archive.c (_bfd_find_nested_archive): New function.
> 	(get_extended_arelt_filename): Add origin parameter.
> 	(_bfd_generic_read_ar_hdr_mag): Deal with extended name
> 	combined with a file offset.
> 	(append_relative_path): New function.
> 	(_bfd_get_elt_at_filepos): Deal with external members and
> 	nested archives.
> 	(bfd_generic_openr_next_archived_file): Thin archives.
> 	(bfd_generic_archive_p): Recognize new magic string.
> 	(adjust_relative_path): New function.
> 	(_bfd_construct_extended_name_table): Construct extended
> 	names for thin archive members.
> 	(_bfd_write_archive_contents): Emit new magic string, skip
> 	copying files for thin archives.
> 	* bfd/bfd-in.h (bfd_is_thin_archive): New macro.
> 	* bfd/bfd.c (struct bfd): New fields for thin archives.
> 	* bfd/libbfd-in.h (struct areltdata): New field for thin archives.
> 	* bfd/opncls.c (bfd_close): Delete BFDs for nested archives.
> 	* binutils/ar.c (make_thin_archive): New global flag.
> 	(map_over_members): Deal with full pathnames in thin archives.
> 	(usage, main): Add 'T' option for building thin archives.
> 	(replace_members): Pass thin archive flag to ar_emul_append.
> 	* binutils/arsup.c (ar_open): Initialize new flag.
> 	* binutils/binemul.c (ar_emul_append): Add new parameter for
> 	flattening nested archives.
> 	(do_ar_emul_default_append): New function.
> 	(ar_emul_default_append): Factored out recursive code.
> 	* binutils/binemul.h (ar_emul_default_append): Add new parameter.
> 	(struct bin_emulation_xfer_struct): New parameter for ar_append.
> 	* binutils/dlltool.c (gen_lib_file): Initialize thin archive flag.
> 	* binutils/emul_aix.c (ar_emul_aix_internal): Add new flatten
> 	parameter, currently unimplemented.
> 	All callers changed.
> 	* binutils/objcopy.c (copy_archive): Preserve thin archive flag.
> 	* binutils/doc/binutils.texi: Update ar documentation.
> 	* binutils/testsuite/binutils-all/ar.exp: Add thin archive tests.
> 	* include/aout/ar.h (ARMAGT): New magic string for thin archives.

Approved and applied.  I made a few small changes, mostly formatting, 
although I did also take the time to fix the few cases where you 
declared a variable in the middle of a block of code, and the AIX 
emulation support.

Cheers
   Nick

PS. I have not checked yet, but are thin archives compatible with Ian's 
new linker ?