archive.c

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/* BFD back-end for archive files (libraries).
   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   2000
   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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 <<bfd_openr_next_archived_file>> 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.

	Archive contents of output BFDs are chained through the
	<<next>> pointer in a BFD.  The first one is findable through
	the <<archive_head>> slot of the archive.  Set it with
	<<bfd_set_archive_head>> (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 <<archive.c>>.

*/

/* 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.
   We currently can read BSD 4.4 archives, but not write them.
*/

/* 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 paces) 23 characters long,
		      BSD 4.4 style, full name follows header.
		      Implemented for reading, not writing.
 " 18             " - Long name 18 characters long, extended pseudo-BSD.
 */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "aout/ar.h"
#include "aout/ranlib.h"
#include <ctype.h>

#ifndef errno
extern int errno;
#endif

#ifdef GNU960
#define BFD_GNU960_ARMAG(abfd)	(BFD_COFF_FILE_P((abfd)) ? ARMAG : ARMAGB)
#endif

/* Define offsetof for those systems which lack it */

#ifndef offsetof
#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
#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 *arelt;
  struct ar_cache *next;
};

#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)

static char *get_extended_arelt_filename PARAMS ((bfd *arch,
						  const char *name));
static boolean do_slurp_bsd_armap PARAMS ((bfd *abfd));
static boolean do_slurp_coff_armap PARAMS ((bfd *abfd));
static const char *normalize PARAMS ((bfd *, const char *file));
static struct areltdata *bfd_ar_hdr_from_filesystem PARAMS ((bfd *abfd,
							     const char *,
							     bfd *member));

boolean
_bfd_generic_mkarchive (abfd)
     bfd *abfd;
{
  abfd->tdata.aout_ar_data = ((struct artdata *)
			      bfd_zalloc (abfd, sizeof (struct artdata)));

  if (bfd_ardata (abfd) == NULL)
    return false;

  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)->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 <<BFD_NO_MORE_SYMBOLS>> as the @var{previous} entry to get
	the first one; returns <<BFD_NO_MORE_SYMBOLS>> when you've already
	got the last one.

	A <<carsym>> is a canonical archive symbol.  The only
	user-visible element is its name, a null-terminated string.
*/

symindex
bfd_get_next_mapent (abfd, prev, entry)
     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 (obfd)
     bfd *obfd;
{
  return _bfd_new_bfd_contained_in (obfd);
}

/*
FUNCTION
	bfd_set_archive_head

SYNOPSIS
	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}.
*/

boolean
bfd_set_archive_head (output_archive, new_head)
     bfd *output_archive;
     bfd *new_head;
{

  output_archive->archive_head = new_head;
  return true;
}

bfd *
_bfd_look_for_bfd_in_cache (arch_bfd, filepos)
     bfd *arch_bfd;
     file_ptr filepos;
{
  struct ar_cache *current;

  for (current = bfd_ardata (arch_bfd)->cache; current != NULL;
       current = current->next)
    if (current->ptr == filepos)
      return current->arelt;

  return NULL;
}

/* Kind of stupid to call cons for each one, but we don't do too many */
boolean
_bfd_add_bfd_to_archive_cache (arch_bfd, filepos, new_elt)
     bfd *arch_bfd, *new_elt;
     file_ptr filepos;
{
  struct ar_cache *new_cache = ((struct ar_cache *)
				bfd_zalloc (arch_bfd,
					    sizeof (struct ar_cache)));

  if (new_cache == NULL)
    return false;

  new_cache->ptr = filepos;
  new_cache->arelt = new_elt;
  new_cache->next = (struct ar_cache *) NULL;
  if (bfd_ardata (arch_bfd)->cache == NULL)
    bfd_ardata (arch_bfd)->cache = new_cache;
  else
    {
      struct ar_cache *current = bfd_ardata (arch_bfd)->cache;

      while (current->next != NULL)
	current = current->next;
      current->next = new_cache;
    }

  return true;
}

/* The name begins with space.  Hence the rest of the name is an index into
   the string table.  */

static char *
get_extended_arelt_filename (arch, name)
     bfd *arch;
     const char *name;
{
  unsigned long index = 0;

  /* 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.  */
  index = strtol (name + 1, NULL, 10);
  if (errno != 0)
    {
      bfd_set_error (bfd_error_malformed_archive);
      return NULL;
    }

  return bfd_ardata (arch)->extended_names + 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.
*/

PTR
_bfd_generic_read_ar_hdr (abfd)
     bfd *abfd;
{
  return _bfd_generic_read_ar_hdr_mag (abfd, (const char *) 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.  */

PTR
_bfd_generic_read_ar_hdr_mag (abfd, mag)
     bfd *abfd;
     const char *mag;
{
  struct ar_hdr hdr;
  char *hdrp = (char *) &hdr;
  unsigned int parsed_size;
  struct areltdata *ared;
  char *filename = NULL;
  unsigned int namelen = 0;
  unsigned int allocsize = sizeof (struct areltdata) + sizeof (struct ar_hdr);
  char *allocptr = 0;

  if (bfd_read ((PTR) hdrp, 1, 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;
  parsed_size = strtol (hdr.ar_size, NULL, 10);
  if (errno != 0)
    {
      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);
      if (filename == NULL)
	{
	  bfd_set_error (bfd_error_malformed_archive);
	  return NULL;
	}
    }
  /* BSD4.4-style long filename.
     Only implemented for reading, so far!  */
  else if (hdr.ar_name[0] == '#'
	   && hdr.ar_name[1] == '1'
	   && hdr.ar_name[2] == '/'
	   && isdigit ((unsigned char) hdr.ar_name[3]))
    {
      /* BSD-4.4 extended name */
      namelen = atoi (&hdr.ar_name[3]);
      allocsize += namelen + 1;
      parsed_size -= namelen;

      allocptr = bfd_zalloc (abfd, allocsize);
      if (allocptr == NULL)
	return NULL;
      filename = (allocptr
		  + sizeof (struct areltdata)
		  + sizeof (struct ar_hdr));
      if (bfd_read (filename, 1, namelen, abfd) != namelen)
	{
	  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 = memchr (hdr.ar_name, '\0', ar_maxnamelen (abfd));
      if (e == NULL)
	{