Subversion Repositories Kolibri OS

/* BFD back-end for archive files (libraries).

   Copyright (C) 1990-2015 Free Software Foundation, Inc.

   Written by Cygnus Support.  Mostly Gumby Henkel-Wallace's fault.

   This file is part of BFD, the Binary File Descriptor library.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */

/*

@setfilename archive-info

SECTION

	Archives

DESCRIPTION

	An archive (or library) is just another BFD.  It has a symbol

	table, although there's not much a user program will do with it.

	The big difference between an archive BFD and an ordinary BFD

	is that the archive doesn't have sections.  Instead it has a

	chain of BFDs that are considered its contents.  These BFDs can

	be manipulated like any other.  The BFDs contained in an

	archive opened for reading will all be opened for reading.  You

	may put either input or output BFDs into an archive opened for

	output; they will be handled correctly when the archive is closed.

	Use <> to step through

	the contents of an archive opened for input.  You don't

	have to read the entire archive if you don't want

	to!  Read it until you find what you want.

	A BFD returned by <> can be

	closed manually with <>.  If you do not close it,

	then a second iteration through the members of an archive may

	return the same BFD.  If you close the archive BFD, then all

	the member BFDs will automatically be closed as well.

	Archive contents of output BFDs are chained through the

	<> pointer in a BFD.  The first one is findable

	through the <> slot of the archive.  Set it with

	<> (q.v.).  A given BFD may be in only

	one open output archive at a time.

	As expected, the BFD archive code is more general than the

	archive code of any given environment.  BFD archives may

	contain files of different formats (e.g., a.out and coff) and

	even different architectures.  You may even place archives

	recursively into archives!

	This can cause unexpected confusion, since some archive

	formats are more expressive than others.  For instance, Intel

	COFF archives can preserve long filenames; SunOS a.out archives

	cannot.  If you move a file from the first to the second

	format and back again, the filename may be truncated.

	Likewise, different a.out environments have different

	conventions as to how they truncate filenames, whether they

	preserve directory names in filenames, etc.  When

	interoperating with native tools, be sure your files are

	homogeneous.

	Beware: most of these formats do not react well to the

	presence of spaces in filenames.  We do the best we can, but

	can't always handle this case due to restrictions in the format of

	archives.  Many Unix utilities are braindead in regards to

	spaces and such in filenames anyway, so this shouldn't be much

	of a restriction.

	Archives are supported in BFD in <>.

SUBSECTION

	Archive functions

*/

/* Assumes:

   o - all archive elements start on an even boundary, newline padded;

   o - all arch headers are char *;

   o - all arch headers are the same size (across architectures).

*/

/* Some formats provide a way to cram a long filename into the short

   (16 chars) space provided by a BSD archive.  The trick is: make a

   special "file" in the front of the archive, sort of like the SYMDEF

   entry.  If the filename is too long to fit, put it in the extended

   name table, and use its index as the filename.  To prevent

   confusion prepend the index with a space.  This means you can't

   have filenames that start with a space, but then again, many Unix

   utilities can't handle that anyway.

   This scheme unfortunately requires that you stand on your head in

   order to write an archive since you need to put a magic file at the

   front, and need to touch every entry to do so.  C'est la vie.

   We support two variants of this idea:

   The SVR4 format (extended name table is named "//"),

   and an extended pseudo-BSD variant (extended name table is named

   "ARFILENAMES/").  The origin of the latter format is uncertain.

   BSD 4.4 uses a third scheme:  It writes a long filename

   directly after the header.  This allows 'ar q' to work.

*/

/* Summary of archive member names:

 Symbol table (must be first):

 "__.SYMDEF       " - Symbol table, Berkeley style, produced by ranlib.

 "/               " - Symbol table, system 5 style.

 Long name table (must be before regular file members):

 "//              " - Long name table, System 5 R4 style.

 "ARFILENAMES/    " - Long name table, non-standard extended BSD (not BSD 4.4).

 Regular file members with short names:

 "filename.o/     " - Regular file, System 5 style (embedded spaces ok).

 "filename.o      " - Regular file, Berkeley style (no embedded spaces).

 Regular files with long names (or embedded spaces, for BSD variants):

 "/18             " - SVR4 style, name at offset 18 in name table.

 "#1/23           " - Long name (or embedded spaces) 23 characters long,

		      BSD 4.4 style, full name follows header.

 " 18             " - Long name 18 characters long, extended pseudo-BSD.

 */

#include "sysdep.h"

#include "bfd.h"

#include "libiberty.h"

#include "libbfd.h"

#include "aout/ar.h"

#include "aout/ranlib.h"

#include "safe-ctype.h"

#include "hashtab.h"

#include "filenames.h"

#include "bfdlink.h"

#ifndef errno

extern int errno;

#endif

/* We keep a cache of archive filepointers to archive elements to

   speed up searching the archive by filepos.  We only add an entry to

   the cache when we actually read one.  We also don't sort the cache;

   it's generally short enough to search linearly.

   Note that the pointers here point to the front of the ar_hdr, not

   to the front of the contents!  */

struct ar_cache

{

  file_ptr ptr;

  bfd *arbfd;

};

#define ar_padchar(abfd) ((abfd)->xvec->ar_pad_char)

#define ar_maxnamelen(abfd) ((abfd)->xvec->ar_max_namelen)

#define arch_eltdata(bfd) ((struct areltdata *) ((bfd)->arelt_data))

#define arch_hdr(bfd) ((struct ar_hdr *) arch_eltdata (bfd)->arch_header)

/* True iff NAME designated a BSD 4.4 extended name.  */

#define is_bsd44_extended_name(NAME) \

  (NAME[0] == '#'  && NAME[1] == '1' && NAME[2] == '/' && ISDIGIT (NAME[3]))

void

_bfd_ar_spacepad (char *p, size_t n, const char *fmt, long val)

{

  static char buf[20];

  size_t len;

  snprintf (buf, sizeof (buf), fmt, val);

  len = strlen (buf);

  if (len < n)

    {

      memcpy (p, buf, len);

      memset (p + len, ' ', n - len);

    }

  else

    memcpy (p, buf, n);

}

bfd_boolean

_bfd_ar_sizepad (char *p, size_t n, bfd_size_type size)

{

  static char buf[21];

  size_t len;

  snprintf (buf, sizeof (buf), "%-10" BFD_VMA_FMT "u", size);

  len = strlen (buf);

  if (len > n)

    {

      bfd_set_error (bfd_error_file_too_big);

      return FALSE;

    }

  if (len < n)

    {

      memcpy (p, buf, len);

      memset (p + len, ' ', n - len);

    }

  else

    memcpy (p, buf, n);

  return TRUE;

}

bfd_boolean

_bfd_generic_mkarchive (bfd *abfd)

{

  bfd_size_type amt = sizeof (struct artdata);

  abfd->tdata.aout_ar_data = (struct artdata *) bfd_zalloc (abfd, amt);

  if (bfd_ardata (abfd) == NULL)

    return FALSE;

  /* Already cleared by bfd_zalloc above.

     bfd_ardata (abfd)->cache = NULL;

     bfd_ardata (abfd)->archive_head = NULL;

     bfd_ardata (abfd)->symdefs = NULL;

     bfd_ardata (abfd)->extended_names = NULL;

     bfd_ardata (abfd)->extended_names_size = 0;

     bfd_ardata (abfd)->tdata = NULL;  */

  return TRUE;

}

/*

FUNCTION

	bfd_get_next_mapent

SYNOPSIS

	symindex bfd_get_next_mapent

	  (bfd *abfd, symindex previous, carsym **sym);

DESCRIPTION

	Step through archive @var{abfd}'s symbol table (if it

	has one).  Successively update @var{sym} with the next symbol's

	information, returning that symbol's (internal) index into the

	symbol table.

	Supply <> as the @var{previous} entry to get

	the first one; returns <> when you've already

	got the last one.

	A <> is a canonical archive symbol.  The only

	user-visible element is its name, a null-terminated string.

*/

symindex

bfd_get_next_mapent (bfd *abfd, symindex prev, carsym **entry)

{

  if (!bfd_has_map (abfd))

    {

      bfd_set_error (bfd_error_invalid_operation);

      return BFD_NO_MORE_SYMBOLS;

    }

  if (prev == BFD_NO_MORE_SYMBOLS)

    prev = 0;

  else

    ++prev;

  if (prev >= bfd_ardata (abfd)->symdef_count)

    return BFD_NO_MORE_SYMBOLS;

  *entry = (bfd_ardata (abfd)->symdefs + prev);

  return prev;

}

/* To be called by backends only.  */

bfd *

_bfd_create_empty_archive_element_shell (bfd *obfd)

{

  return _bfd_new_bfd_contained_in (obfd);

}

/*

FUNCTION

	bfd_set_archive_head

SYNOPSIS

	bfd_boolean bfd_set_archive_head (bfd *output, bfd *new_head);

DESCRIPTION

	Set the head of the chain of

	BFDs contained in the archive @var{output} to @var{new_head}.

*/

bfd_boolean

bfd_set_archive_head (bfd *output_archive, bfd *new_head)

{

  output_archive->archive_head = new_head;

  return TRUE;

}

bfd *

_bfd_look_for_bfd_in_cache (bfd *arch_bfd, file_ptr filepos)

{

  htab_t hash_table = bfd_ardata (arch_bfd)->cache;

  struct ar_cache m;

  m.ptr = filepos;

  if (hash_table)

    {

      struct ar_cache *entry = (struct ar_cache *) htab_find (hash_table, &m);

      if (!entry)

	return NULL;

      /* Unfortunately this flag is set after checking that we have

	 an archive, and checking for an archive means one element has

	 sneaked into the cache.  */

      entry->arbfd->no_export = arch_bfd->no_export;

	return entry->arbfd;

    }

  else

    return NULL;

}

static hashval_t

hash_file_ptr (const void * p)

{

  return (hashval_t) (((struct ar_cache *) p)->ptr);

}

/* Returns non-zero if P1 and P2 are equal.  */

static int

eq_file_ptr (const void * p1, const void * p2)

{

  struct ar_cache *arc1 = (struct ar_cache *) p1;

  struct ar_cache *arc2 = (struct ar_cache *) p2;

  return arc1->ptr == arc2->ptr;

}

/* The calloc function doesn't always take size_t (e.g. on VMS)

   so wrap it to avoid a compile time warning.   */

static void *

_bfd_calloc_wrapper (size_t a, size_t b)

{

  return calloc (a, b);

}

/* Kind of stupid to call cons for each one, but we don't do too many.  */

bfd_boolean

_bfd_add_bfd_to_archive_cache (bfd *arch_bfd, file_ptr filepos, bfd *new_elt)

{

  struct ar_cache *cache;

  htab_t hash_table = bfd_ardata (arch_bfd)->cache;

  /* If the hash table hasn't been created, create it.  */

  if (hash_table == NULL)

    {

      hash_table = htab_create_alloc (16, hash_file_ptr, eq_file_ptr,

				      NULL, _bfd_calloc_wrapper, free);

      if (hash_table == NULL)

	return FALSE;

      bfd_ardata (arch_bfd)->cache = hash_table;

    }

  /* Insert new_elt into the hash table by filepos.  */

  cache = (struct ar_cache *) bfd_zalloc (arch_bfd, sizeof (struct ar_cache));

  cache->ptr = filepos;

  cache->arbfd = new_elt;

  *htab_find_slot (hash_table, (const void *) cache, INSERT) = cache;

  /* Provide a means of accessing this from child.  */

  arch_eltdata (new_elt)->parent_cache = hash_table;

  arch_eltdata (new_elt)->key = filepos;

  return TRUE;

}

static bfd *

open_nested_file (const char *filename, bfd *archive)

{

  const char *target;

  bfd *n_bfd;

  target = NULL;

  if (!archive->target_defaulted)

    target = archive->xvec->name;

  n_bfd = bfd_openr (filename, target);

  if (n_bfd != NULL)

    {

      n_bfd->lto_output = archive->lto_output;

      n_bfd->no_export = archive->no_export;

    }

  return n_bfd;

}

static bfd *

find_nested_archive (const char *filename, bfd *arch_bfd)

{

  bfd *abfd;

  /* PR 15140: Don't allow a nested archive pointing to itself.  */

  if (filename_cmp (filename, arch_bfd->filename) == 0)

    {

      bfd_set_error (bfd_error_malformed_archive);

      return NULL;

    }

  for (abfd = arch_bfd->nested_archives;

       abfd != NULL;

       abfd = abfd->archive_next)

    {

      if (filename_cmp (filename, abfd->filename) == 0)

	return abfd;

    }

  abfd = open_nested_file (filename, arch_bfd);

  if (abfd)

    {

      abfd->archive_next = arch_bfd->nested_archives;

      arch_bfd->nested_archives = abfd;

    }

  return abfd;

}

/* The name begins with space.  Hence the rest of the name is an index into

   the string table.  */

static char *

get_extended_arelt_filename (bfd *arch, const char *name, file_ptr *originp)

{

  unsigned long table_index = 0;

  const char *endp;

  /* Should extract string so that I can guarantee not to overflow into

     the next region, but I'm too lazy.  */

  errno = 0;

  /* Skip first char, which is '/' in SVR4 or ' ' in some other variants.  */

  table_index = strtol (name + 1, (char **) &endp, 10);

  if (errno != 0 || table_index >= bfd_ardata (arch)->extended_names_size)

    {

      bfd_set_error (bfd_error_malformed_archive);

      return NULL;

    }

  /* In a thin archive, a member of an archive-within-an-archive

     will have the offset in the inner archive encoded here.  */

  if (bfd_is_thin_archive (arch) && endp != NULL && *endp == ':')

    {

      file_ptr origin = strtol (endp + 1, NULL, 10);

      if (errno != 0)

	{

	  bfd_set_error (bfd_error_malformed_archive);

	  return NULL;

	}

      *originp = origin;

    }

  else

    *originp = 0;

  return bfd_ardata (arch)->extended_names + table_index;

}

/* This functions reads an arch header and returns an areltdata pointer, or

   NULL on error.

   Presumes the file pointer is already in the right place (ie pointing

   to the ar_hdr in the file).   Moves the file pointer; on success it

   should be pointing to the front of the file contents; on failure it

   could have been moved arbitrarily.  */

void *

_bfd_generic_read_ar_hdr (bfd *abfd)

{

  return _bfd_generic_read_ar_hdr_mag (abfd, NULL);

}

/* Alpha ECOFF uses an optional different ARFMAG value, so we have a

   variant of _bfd_generic_read_ar_hdr which accepts a magic string.  */

void *

_bfd_generic_read_ar_hdr_mag (bfd *abfd, const char *mag)

{

  struct ar_hdr hdr;

  char *hdrp = (char *) &hdr;

  bfd_size_type parsed_size;

  struct areltdata *ared;

  char *filename = NULL;

  bfd_size_type namelen = 0;

  bfd_size_type allocsize = sizeof (struct areltdata) + sizeof (struct ar_hdr);

  char *allocptr = 0;

  file_ptr origin = 0;

  unsigned int extra_size = 0;

  char fmag_save;

  int scan;

  if (bfd_bread (hdrp, sizeof (struct ar_hdr), abfd) != sizeof (struct ar_hdr))

    {

      if (bfd_get_error () != bfd_error_system_call)

	bfd_set_error (bfd_error_no_more_archived_files);

      return NULL;

    }

  if (strncmp (hdr.ar_fmag, ARFMAG, 2) != 0

      && (mag == NULL

	  || strncmp (hdr.ar_fmag, mag, 2) != 0))

    {

      bfd_set_error (bfd_error_malformed_archive);

      return NULL;

    }

  errno = 0;

  fmag_save = hdr.ar_fmag[0];

  hdr.ar_fmag[0] = 0;

  scan = sscanf (hdr.ar_size, "%" BFD_VMA_FMT "u", &parsed_size);

  hdr.ar_fmag[0] = fmag_save;

  if (scan != 1)

    {

      bfd_set_error (bfd_error_malformed_archive);

      return NULL;

    }

  /* Extract the filename from the archive - there are two ways to

     specify an extended name table, either the first char of the

     name is a space, or it's a slash.  */

  if ((hdr.ar_name[0] == '/'

       || (hdr.ar_name[0] == ' '

	   && memchr (hdr.ar_name, '/', ar_maxnamelen (abfd)) == NULL))

      && bfd_ardata (abfd)->extended_names != NULL)

    {

      filename = get_extended_arelt_filename (abfd, hdr.ar_name, &origin);

      if (filename == NULL)

	return NULL;

    }

  /* BSD4.4-style long filename.  */

  else if (is_bsd44_extended_name (hdr.ar_name))

    {

      /* BSD-4.4 extended name */

      namelen = atoi (&hdr.ar_name[3]);

      allocsize += namelen + 1;

      parsed_size -= namelen;

      extra_size = namelen;

      allocptr = (char *) bfd_zmalloc (allocsize);

      if (allocptr == NULL)

	return NULL;

      filename = (allocptr

		  + sizeof (struct areltdata)

		  + sizeof (struct ar_hdr));

      if (bfd_bread (filename, namelen, abfd) != namelen)

	{

	  free (allocptr);

	  if (bfd_get_error () != bfd_error_system_call)

	    bfd_set_error (bfd_error_no_more_archived_files);

	  return NULL;

	}

      filename[namelen] = '\0';

    }

  else

    {

      /* We judge the end of the name by looking for '/' or ' '.

	 Note:  The SYSV format (terminated by '/') allows embedded

	 spaces, so only look for ' ' if we don't find '/'.  */

      char *e;

      e = (char *) memchr (hdr.ar_name, '\0', ar_maxnamelen (abfd));

      if (e == NULL)

	{

	  e = (char *) memchr (hdr.ar_name, '/', ar_maxnamelen (abfd));

	  if (e == NULL)

	    e = (char *) memchr (hdr.ar_name, ' ', ar_maxnamelen (abfd));

	}

      if (e != NULL)

	namelen = e - hdr.ar_name;

      else

	{

	  /* If we didn't find a termination character, then the name

	     must be the entire field.  */

	  namelen = ar_maxnamelen (abfd);

	}

      allocsize += namelen + 1;

    }

  if (!allocptr)

    {

      allocptr = (char *) bfd_zmalloc (allocsize);

      if (allocptr == NULL)

	return NULL;

    }

  ared = (struct areltdata *) allocptr;

  ared->arch_header = allocptr + sizeof (struct areltdata);

  memcpy (ared->arch_header, &hdr, sizeof (struct ar_hdr));

  ared->parsed_size = parsed_size;

  ared->extra_size = extra_size;

  ared->origin = origin;

  if (filename != NULL)

    ared->filename = filename;

  else

    {

      ared->filename = allocptr + (sizeof (struct areltdata) +

				   sizeof (struct ar_hdr));

      if (namelen)

	memcpy (ared->filename, hdr.ar_name, namelen);

      ared->filename[namelen] = '\0';

    }

  return ared;

}

/* Append the relative pathname for a member of the thin archive

   to the pathname of the directory containing the archive.  */

char *

_bfd_append_relative_path (bfd *arch, char *elt_name)

{

  const char *arch_name = arch->filename;

  const char *base_name = lbasename (arch_name);

  size_t prefix_len;

  char *filename;

  if (base_name == arch_name)

    return elt_name;

  prefix_len = base_name - arch_name;

  filename = (char *) bfd_alloc (arch, prefix_len + strlen (elt_name) + 1);

  if (filename == NULL)

    return NULL;

  strncpy (filename, arch_name, prefix_len);

  strcpy (filename + prefix_len, elt_name);

  return filename;

}

/* This is an internal function; it's mainly used when indexing

   through the archive symbol table, but also used to get the next

   element, since it handles the bookkeeping so nicely for us.  */

bfd *

_bfd_get_elt_at_filepos (bfd *archive, file_ptr filepos)

{

  struct areltdata *new_areldata;

  bfd *n_bfd;

  char *filename;

  n_bfd = _bfd_look_for_bfd_in_cache (archive, filepos);

  if (n_bfd)

    return n_bfd;

  if (0 > bfd_seek (archive, filepos, SEEK_SET))

    return NULL;

  if ((new_areldata = (struct areltdata *) _bfd_read_ar_hdr (archive)) == NULL)

    return NULL;

  filename = new_areldata->filename;

  if (bfd_is_thin_archive (archive))

    {

      /* This is a proxy entry for an external file.  */

      if (! IS_ABSOLUTE_PATH (filename))

	{

	  filename = _bfd_append_relative_path (archive, filename);

	  if (filename == NULL)

	    {

	      free (new_areldata);

	      return NULL;

	    }

	}

      if (new_areldata->origin > 0)

	{

	  /* This proxy entry refers to an element of a nested archive.

	     Locate the member of that archive and return a bfd for it.  */

	  bfd *ext_arch = find_nested_archive (filename, archive);

	  if (ext_arch == NULL

	      || ! bfd_check_format (ext_arch, bfd_archive))

	    {

	      free (new_areldata);

	      return NULL;

	    }

	  n_bfd = _bfd_get_elt_at_filepos (ext_arch, new_areldata->origin);

	  if (n_bfd == NULL)

	    {

	      free (new_areldata);

	      return NULL;

	    }

	  n_bfd->proxy_origin = bfd_tell (archive);

	  return n_bfd;

	}

      /* It's not an element of a nested archive;

	 open the external file as a bfd.  */

      n_bfd = open_nested_file (filename, archive);

      if (n_bfd == NULL)

	bfd_set_error (bfd_error_malformed_archive);

    }

  else

    {

      n_bfd = _bfd_create_empty_archive_element_shell (archive);

    }

  if (n_bfd == NULL)

    {

      free (new_areldata);

      return NULL;

    }

  n_bfd->proxy_origin = bfd_tell (archive);

  if (bfd_is_thin_archive (archive))

    {

      n_bfd->origin = 0;

    }

  else

    {

      n_bfd->origin = n_bfd->proxy_origin;

      n_bfd->filename = xstrdup (filename);

    }

  n_bfd->arelt_data = new_areldata;

  /* Copy BFD_COMPRESS, BFD_DECOMPRESS and BFD_COMPRESS_GABI flags.  */

  n_bfd->flags |= archive->flags & (BFD_COMPRESS

				    | BFD_DECOMPRESS

				    | BFD_COMPRESS_GABI);

  /* Copy is_linker_input.  */

  n_bfd->is_linker_input = archive->is_linker_input;

  if (_bfd_add_bfd_to_archive_cache (archive, filepos, n_bfd))

    return n_bfd;

  free (new_areldata);

  n_bfd->arelt_data = NULL;

  return NULL;

}

/* Return the BFD which is referenced by the symbol in ABFD indexed by

   SYM_INDEX.  SYM_INDEX should have been returned by bfd_get_next_mapent.  */

bfd *

_bfd_generic_get_elt_at_index (bfd *abfd, symindex sym_index)

{

  carsym *entry;

  entry = bfd_ardata (abfd)->symdefs + sym_index;

  return _bfd_get_elt_at_filepos (abfd, entry->file_offset);

}

/*

FUNCTION

	bfd_openr_next_archived_file

SYNOPSIS

	bfd *bfd_openr_next_archived_file (bfd *archive, bfd *previous);

DESCRIPTION

	Provided a BFD, @var{archive}, containing an archive and NULL, open

	an input BFD on the first contained element and returns that.

	Subsequent calls should pass

	the archive and the previous return value to return a created

	BFD to the next contained element. NULL is returned when there

	are no more.

*/

bfd *

bfd_openr_next_archived_file (bfd *archive, bfd *last_file)

{

  if ((bfd_get_format (archive) != bfd_archive)

      || (archive->direction == write_direction))

    {

      bfd_set_error (bfd_error_invalid_operation);

      return NULL;

    }

  return BFD_SEND (archive,

		   openr_next_archived_file, (archive, last_file));

}

bfd *

bfd_generic_openr_next_archived_file (bfd *archive, bfd *last_file)

{

  ufile_ptr filestart;

  if (!last_file)

    filestart = bfd_ardata (archive)->first_file_filepos;

  else

    {

      filestart = last_file->proxy_origin;

      if (! bfd_is_thin_archive (archive))

	{

      bfd_size_type size = arelt_size (last_file);

	filestart += size;

      /* Pad to an even boundary...

	 Note that last_file->origin can be odd in the case of

	 BSD-4.4-style element with a long odd size.  */

      filestart += filestart % 2;

	  if (filestart <= last_file->proxy_origin)

	    {

	      /* Prevent looping.  See PR19256.  */

	      bfd_set_error (bfd_error_malformed_archive);

	      return NULL;

	    }

	}

    }

  return _bfd_get_elt_at_filepos (archive, filestart);

}

const bfd_target *

bfd_generic_archive_p (bfd *abfd)

{

  struct artdata *tdata_hold;

  char armag[SARMAG + 1];

  bfd_size_type amt;

  if (bfd_bread (armag, SARMAG, abfd) != SARMAG)

    {

      if (bfd_get_error () != bfd_error_system_call)

	bfd_set_error (bfd_error_wrong_format);

      return NULL;

    }

  bfd_is_thin_archive (abfd) = (strncmp (armag, ARMAGT, SARMAG) == 0);

  if (strncmp (armag, ARMAG, SARMAG) != 0

      && strncmp (armag, ARMAGB, SARMAG) != 0

      && ! bfd_is_thin_archive (abfd))

    return NULL;

  tdata_hold = bfd_ardata (abfd);

  amt = sizeof (struct artdata);

  bfd_ardata (abfd) = (struct artdata *) bfd_zalloc (abfd, amt);

  if (bfd_ardata (abfd) == NULL)

    {

      bfd_ardata (abfd) = tdata_hold;

      return NULL;

    }

  bfd_ardata (abfd)->first_file_filepos = SARMAG;

  /* Cleared by bfd_zalloc above.

     bfd_ardata (abfd)->cache = NULL;

     bfd_ardata (abfd)->archive_head = NULL;

     bfd_ardata (abfd)->symdefs = NULL;

     bfd_ardata (abfd)->extended_names = NULL;

     bfd_ardata (abfd)->extended_names_size = 0;

     bfd_ardata (abfd)->tdata = NULL;  */

  if (!BFD_SEND (abfd, _bfd_slurp_armap, (abfd))

      || !BFD_SEND (abfd, _bfd_slurp_extended_name_table, (abfd)))

    {

      if (bfd_get_error () != bfd_error_system_call)

	bfd_set_error (bfd_error_wrong_format);

      bfd_release (abfd, bfd_ardata (abfd));

      bfd_ardata (abfd) = tdata_hold;

      return NULL;

    }

  if (abfd->target_defaulted && bfd_has_map (abfd))

    {

      bfd *first;

      /* This archive has a map, so we may presume that the contents

	 are object files.  Make sure that if the first file in the

	 archive can be recognized as an object file, it is for this

	 target.  If not, assume that this is the wrong format.  If

	 the first file is not an object file, somebody is doing

	 something weird, and we permit it so that ar -t will work.

	 This is done because any normal format will recognize any

	 normal archive, regardless of the format of the object files.

	 We do accept an empty archive.  */

      first = bfd_openr_next_archived_file (abfd, NULL);

      if (first != NULL)

	{

	  first->target_defaulted = FALSE;

	  if (bfd_check_format (first, bfd_object)

	      && first->xvec != abfd->xvec)

	    bfd_set_error (bfd_error_wrong_object_format);

	  /* And we ought to close `first' here too.  */

	}

    }

  return abfd->xvec;

}

/* Some constants for a 32 bit BSD archive structure.  We do not

   support 64 bit archives presently; so far as I know, none actually

   exist.  Supporting them would require changing these constants, and

   changing some H_GET_32 to H_GET_64.  */

/* The size of an external symdef structure.  */

#define BSD_SYMDEF_SIZE 8

/* The offset from the start of a symdef structure to the file offset.  */

#define BSD_SYMDEF_OFFSET_SIZE 4

/* The size of the symdef count.  */

#define BSD_SYMDEF_COUNT_SIZE 4

/* The size of the string count.  */

#define BSD_STRING_COUNT_SIZE 4

/* Read a BSD-style archive symbol table.  Returns FALSE on error,

   TRUE otherwise.  */

static bfd_boolean

do_slurp_bsd_armap (bfd *abfd)

{

  struct areltdata *mapdata;

  unsigned int counter;

  bfd_byte *raw_armap, *rbase;

  struct artdata *ardata = bfd_ardata (abfd);

  char *stringbase;

  bfd_size_type parsed_size, amt;

  carsym *set;

  mapdata = (struct areltdata *) _bfd_read_ar_hdr (abfd);

  if (mapdata == NULL)

    return FALSE;

  parsed_size = mapdata->parsed_size;

  free (mapdata);

  /* PR 17512: file: 883ff754.  */

  /* PR 17512: file: 0458885f.  */

  if (parsed_size < 4)

    return FALSE;

  raw_armap = (bfd_byte *) bfd_zalloc (abfd, parsed_size);

  if (raw_armap == NULL)

    return FALSE;

  if (bfd_bread (raw_armap, parsed_size, abfd) != parsed_size)

    {

      if (bfd_get_error () != bfd_error_system_call)

	bfd_set_error (bfd_error_malformed_archive);

    byebye:

      bfd_release (abfd, raw_armap);

      return FALSE;

    }

  ardata->symdef_count = H_GET_32 (abfd, raw_armap) / BSD_SYMDEF_SIZE;

  if (ardata->symdef_count * BSD_SYMDEF_SIZE >

      parsed_size - BSD_SYMDEF_COUNT_SIZE)

    {

      /* Probably we're using the wrong byte ordering.  */

      bfd_set_error (bfd_error_wrong_format);

      goto byebye;

    }

  ardata->cache = 0;

  rbase = raw_armap + BSD_SYMDEF_COUNT_SIZE;

  stringbase = ((char *) rbase

		+ ardata->symdef_count * BSD_SYMDEF_SIZE

		+ BSD_STRING_COUNT_SIZE);

  amt = ardata->symdef_count * sizeof (carsym);

  ardata->symdefs = (struct carsym *) bfd_alloc (abfd, amt);

  if (!ardata->symdefs)

    return FALSE;

  for (counter = 0, set = ardata->symdefs;

       counter < ardata->symdef_count;

       counter++, set++, rbase += BSD_SYMDEF_SIZE)

    {

      set->name = H_GET_32 (abfd, rbase) + stringbase;

      set->file_offset = H_GET_32 (abfd, rbase + BSD_SYMDEF_OFFSET_SIZE);

    }

  ardata->first_file_filepos = bfd_tell (abfd);

  /* Pad to an even boundary if you have to.  */

  ardata->first_file_filepos += (ardata->first_file_filepos) % 2;

  /* FIXME, we should provide some way to free raw_ardata when

     we are done using the strings from it.  For now, it seems

     to be allocated on an objalloc anyway...  */

  bfd_has_map (abfd) = TRUE;

  return TRUE;

}

/* Read a COFF archive symbol table.  Returns FALSE on error, TRUE

   otherwise.  */

static bfd_boolean

do_slurp_coff_armap (bfd *abfd)

{

  struct areltdata *mapdata;

  int *raw_armap, *rawptr;

  struct artdata *ardata = bfd_ardata (abfd);

  char *stringbase;

  bfd_size_type stringsize;

  bfd_size_type parsed_size;

  carsym *carsyms;

  bfd_size_type nsymz;		/* Number of symbols in armap.  */

  bfd_vma (*swap) (const void *);

  char int_buf[sizeof (long)];

  bfd_size_type carsym_size, ptrsize;

  unsigned int i;

  mapdata = (struct areltdata *) _bfd_read_ar_hdr (abfd);

  if (mapdata == NULL)

    return FALSE;

  parsed_size = mapdata->parsed_size;

  free (mapdata);

  if (bfd_bread (int_buf, 4, abfd) != 4)

    {

      if (bfd_get_error () != bfd_error_system_call)

	bfd_set_error (bfd_error_malformed_archive);

      return FALSE;

    }

  /* It seems that all numeric information in a coff archive is always

     in big endian format, nomatter the host or target.  */

  swap = bfd_getb32;

  nsymz = bfd_getb32 (int_buf);

  stringsize = parsed_size - (4 * nsymz) - 4;

  /* ... except that some archive formats are broken, and it may be our

     fault - the i960 little endian coff sometimes has big and sometimes

     little, because our tools changed.  Here's a horrible hack to clean

     up the crap.  */

  if (stringsize > 0xfffff

      && bfd_get_arch (abfd) == bfd_arch_i960

      && bfd_get_flavour (abfd) == bfd_target_coff_flavour)

    {

      /* This looks dangerous, let's do it the other way around.  */

      nsymz = bfd_getl32 (int_buf);

      stringsize = parsed_size - (4 * nsymz) - 4;

      swap = bfd_getl32;

    }

  /* The coff armap must be read sequentially.  So we construct a

     bsd-style one in core all at once, for simplicity.  */

  if (nsymz > ~ (bfd_size_type) 0 / sizeof (carsym))

    return FALSE;

  carsym_size = (nsymz * sizeof (carsym));

  ptrsize = (4 * nsymz);

  if (carsym_size + stringsize + 1 <= carsym_size)

    return FALSE;

  ardata->symdefs = (struct carsym *) bfd_zalloc (abfd,

						  carsym_size + stringsize + 1);

  if (ardata->symdefs == NULL)

    return FALSE;

  carsyms = ardata->symdefs;

  stringbase = ((char *) ardata->symdefs) + carsym_size;

  /* Allocate and read in the raw offsets.  */

  raw_armap = (int *) bfd_alloc (abfd, ptrsize);

  if (raw_armap == NULL)

    goto release_symdefs;

  if (bfd_bread (raw_armap, ptrsize, abfd) != ptrsize

      || (bfd_bread (stringbase, stringsize, abfd) != stringsize))

    {

      if (bfd_get_error () != bfd_error_system_call)

	bfd_set_error (bfd_error_malformed_archive);

      goto release_raw_armap;

    }

  /* OK, build the carsyms.  */

  for (i = 0; i < nsymz && stringsize > 0; i++)

    {

      bfd_size_type len;

      rawptr = raw_armap + i;

      carsyms->file_offset = swap ((bfd_byte *) rawptr);

      carsyms->name = stringbase;

      /* PR 17512: file: 4a1d50c1.  */

      len = strnlen (stringbase, stringsize);

      if (len < stringsize)

	len ++;

      stringbase += len;

      stringsize -= len;

      carsyms++;

    }

  *stringbase = 0;

  ardata->symdef_count = nsymz;

  ardata->first_file_filepos = bfd_tell (abfd);

  /* Pad to an even boundary if you have to.  */

  ardata->first_file_filepos += (ardata->first_file_filepos) % 2;

  bfd_has_map (abfd) = TRUE;

  bfd_release (abfd, raw_armap);

  /* Check for a second archive header (as used by PE).  */

  {

    struct areltdata *tmp;

    bfd_seek (abfd, ardata->first_file_filepos, SEEK_SET);

    tmp = (struct areltdata *) _bfd_read_ar_hdr (abfd);

    if (tmp != NULL)

      {

	if (tmp->arch_header[0] == '/'

	    && tmp->arch_header[1] == ' ')

	  {

	    ardata->first_file_filepos +=

	      (tmp->parsed_size + sizeof (struct ar_hdr) + 1) & ~(unsigned) 1;

	  }

	free (tmp);

      }

  }

  return TRUE;

release_raw_armap:

  bfd_release (abfd, raw_armap);

release_symdefs:

  bfd_release (abfd, (ardata)->symdefs);