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/* opncls.c -- open and close a BFD.

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

   Written by Cygnus Support.

   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.  */

#include "sysdep.h"

#include "bfd.h"

#include "objalloc.h"

#include "libbfd.h"

#include "libiberty.h"

#ifndef S_IXUSR

#define S_IXUSR 0100	/* Execute by owner.  */

#endif

#ifndef S_IXGRP

#define S_IXGRP 0010	/* Execute by group.  */

#endif

#ifndef S_IXOTH

#define S_IXOTH 0001	/* Execute by others.  */

#endif

/* Counters used to initialize the bfd identifier.  */

static unsigned int bfd_id_counter = 0;

static unsigned int bfd_reserved_id_counter = 0;

/*

CODE_FRAGMENT

.{* Set to N to open the next N BFDs using an alternate id space.  *}

.extern unsigned int bfd_use_reserved_id;

*/

unsigned int bfd_use_reserved_id = 0;

/* fdopen is a loser -- we should use stdio exclusively.  Unfortunately

   if we do that we can't use fcntl.  */

/* Return a new BFD.  All BFD's are allocated through this routine.  */

bfd *

_bfd_new_bfd (void)

{

  bfd *nbfd;

  nbfd = (bfd *) bfd_zmalloc (sizeof (bfd));

  if (nbfd == NULL)

    return NULL;

  if (bfd_use_reserved_id)

    {

      nbfd->id = --bfd_reserved_id_counter;

      --bfd_use_reserved_id;

    }

  else

    nbfd->id = bfd_id_counter++;

  nbfd->memory = objalloc_create ();

  if (nbfd->memory == NULL)

    {

      bfd_set_error (bfd_error_no_memory);

      free (nbfd);

      return NULL;

    }

  nbfd->arch_info = &bfd_default_arch_struct;

  if (!bfd_hash_table_init_n (& nbfd->section_htab, bfd_section_hash_newfunc,

			      sizeof (struct section_hash_entry), 13))

    {

      free (nbfd);

      return NULL;

    }

  return nbfd;

}

static const struct bfd_iovec opncls_iovec;

/* Allocate a new BFD as a member of archive OBFD.  */

bfd *

_bfd_new_bfd_contained_in (bfd *obfd)

{

  bfd *nbfd;

  nbfd = _bfd_new_bfd ();

  if (nbfd == NULL)

    return NULL;

  nbfd->xvec = obfd->xvec;

  nbfd->iovec = obfd->iovec;

  if (obfd->iovec == &opncls_iovec)

    nbfd->iostream = obfd->iostream;

  nbfd->my_archive = obfd;

  nbfd->direction = read_direction;

  nbfd->target_defaulted = obfd->target_defaulted;

  nbfd->lto_output = obfd->lto_output;

  nbfd->no_export = obfd->no_export;

  return nbfd;

}

/* Delete a BFD.  */

static void

_bfd_delete_bfd (bfd *abfd)

{

  if (abfd->memory)

    {

      bfd_hash_table_free (&abfd->section_htab);

      objalloc_free ((struct objalloc *) abfd->memory);

    }

  if (abfd->filename)

    free ((char *) abfd->filename);

  free (abfd->arelt_data);

  free (abfd);

}

/* Free objalloc memory.  */

bfd_boolean

_bfd_free_cached_info (bfd *abfd)

{

  if (abfd->memory)

    {

      bfd_hash_table_free (&abfd->section_htab);

      objalloc_free ((struct objalloc *) abfd->memory);

      abfd->sections = NULL;

      abfd->section_last = NULL;

      abfd->outsymbols = NULL;

      abfd->tdata.any = NULL;

      abfd->usrdata = NULL;

      abfd->memory = NULL;

    }

  return TRUE;

}

/*

SECTION

	Opening and closing BFDs

SUBSECTION

	Functions for opening and closing

*/

/*

FUNCTION

	bfd_fopen

SYNOPSIS

	bfd *bfd_fopen (const char *filename, const char *target,

                        const char *mode, int fd);

DESCRIPTION

	Open the file @var{filename} with the target @var{target}.

	Return a pointer to the created BFD.  If @var{fd} is not -1,

	then <> is used to open the file; otherwise, <>

	is used.  @var{mode} is passed directly to <> or

	<>.

	Calls <>, so @var{target} is interpreted as by

	that function.

	The new BFD is marked as cacheable iff @var{fd} is -1.

	If <> is returned then an error has occured.   Possible errors

	are <>, <> or

	<> error.

	On error, @var{fd} is always closed.

	A copy of the @var{filename} argument is stored in the newly created

	BFD.  It can be accessed via the bfd_get_filename() macro.

*/

bfd *

bfd_fopen (const char *filename, const char *target, const char *mode, int fd)

{

  bfd *nbfd;

  const bfd_target *target_vec;

  nbfd = _bfd_new_bfd ();

  if (nbfd == NULL)

    {

      if (fd != -1)

	close (fd);

      return NULL;

    }

  target_vec = bfd_find_target (target, nbfd);

  if (target_vec == NULL)

    {

      if (fd != -1)

	close (fd);

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

#ifdef HAVE_FDOPEN

  if (fd != -1)

    nbfd->iostream = fdopen (fd, mode);

  else

#endif

    nbfd->iostream = real_fopen (filename, mode);

  if (nbfd->iostream == NULL)

    {

      bfd_set_error (bfd_error_system_call);

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

  /* OK, put everything where it belongs.  */

  /* PR 11983: Do not cache the original filename, but

     rather make a copy - the original might go away.  */

  nbfd->filename = xstrdup (filename);

  /* Figure out whether the user is opening the file for reading,

     writing, or both, by looking at the MODE argument.  */

  if ((mode[0] == 'r' || mode[0] == 'w' || mode[0] == 'a')

      && mode[1] == '+')

    nbfd->direction = both_direction;

  else if (mode[0] == 'r')

    nbfd->direction = read_direction;

  else

    nbfd->direction = write_direction;

  if (! bfd_cache_init (nbfd))

    {

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

  nbfd->opened_once = TRUE;

  /* If we opened the file by name, mark it cacheable; we can close it

     and reopen it later.  However, if a file descriptor was provided,

     then it may have been opened with special flags that make it

     unsafe to close and reopen the file.  */

  if (fd == -1)

    (void) bfd_set_cacheable (nbfd, TRUE);

  return nbfd;

}

/*

FUNCTION

	bfd_openr

SYNOPSIS

	bfd *bfd_openr (const char *filename, const char *target);

DESCRIPTION

	Open the file @var{filename} (using <>) with the target

	@var{target}.  Return a pointer to the created BFD.

	Calls <>, so @var{target} is interpreted as by

	that function.

	If <> is returned then an error has occured.   Possible errors

	are <>, <> or

	<> error.

	A copy of the @var{filename} argument is stored in the newly created

	BFD.  It can be accessed via the bfd_get_filename() macro.

*/

bfd *

bfd_openr (const char *filename, const char *target)

{

  return bfd_fopen (filename, target, FOPEN_RB, -1);

}

/* Don't try to `optimize' this function:

   o - We lock using stack space so that interrupting the locking

       won't cause a storage leak.

   o - We open the file stream last, since we don't want to have to

       close it if anything goes wrong.  Closing the stream means closing

       the file descriptor too, even though we didn't open it.  */

/*

FUNCTION

	bfd_fdopenr

SYNOPSIS

	bfd *bfd_fdopenr (const char *filename, const char *target, int fd);

DESCRIPTION

	<> is to <> much like <> is to

	<>.  It opens a BFD on a file already described by the

	@var{fd} supplied.

	When the file is later <>d, the file descriptor will

	be closed.  If the caller desires that this file descriptor be

	cached by BFD (opened as needed, closed as needed to free

	descriptors for other opens), with the supplied @var{fd} used as

	an initial file descriptor (but subject to closure at any time),

	call bfd_set_cacheable(bfd, 1) on the returned BFD.  The default

	is to assume no caching; the file descriptor will remain open

	until <>, and will not be affected by BFD operations

	on other files.

	Possible errors are <>,

	<> and <>.

	On error, @var{fd} is closed.

	A copy of the @var{filename} argument is stored in the newly created

	BFD.  It can be accessed via the bfd_get_filename() macro.

*/

bfd *

bfd_fdopenr (const char *filename, const char *target, int fd)

{

  const char *mode;

#if defined(HAVE_FCNTL) && defined(F_GETFL)

  int fdflags;

#endif

#if ! defined(HAVE_FCNTL) || ! defined(F_GETFL)

  mode = FOPEN_RUB; /* Assume full access.  */

#else

  fdflags = fcntl (fd, F_GETFL, NULL);

  if (fdflags == -1)

    {

      int save = errno;

      close (fd);

      errno = save;

      bfd_set_error (bfd_error_system_call);

      return NULL;

    }

  /* (O_ACCMODE) parens are to avoid Ultrix header file bug.  */

  switch (fdflags & (O_ACCMODE))

    {

    case O_RDONLY: mode = FOPEN_RB; break;

    case O_WRONLY: mode = FOPEN_RUB; break;

    case O_RDWR:   mode = FOPEN_RUB; break;

    default: abort ();

    }

#endif

  return bfd_fopen (filename, target, mode, fd);

}

/*

FUNCTION

	bfd_openstreamr

SYNOPSIS

	bfd *bfd_openstreamr (const char * filename, const char * target, void * stream);

DESCRIPTION

	Open a BFD for read access on an existing stdio stream.  When

	the BFD is passed to <>, the stream will be closed.

	A copy of the @var{filename} argument is stored in the newly created

	BFD.  It can be accessed via the bfd_get_filename() macro.

*/

bfd *

bfd_openstreamr (const char *filename, const char *target, void *streamarg)

{

  FILE *stream = (FILE *) streamarg;

  bfd *nbfd;

  const bfd_target *target_vec;

  nbfd = _bfd_new_bfd ();

  if (nbfd == NULL)

    return NULL;

  target_vec = bfd_find_target (target, nbfd);

  if (target_vec == NULL)

    {

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

  nbfd->iostream = stream;

  /* PR 11983: Do not cache the original filename, but

     rather make a copy - the original might go away.  */

  nbfd->filename = xstrdup (filename);

  nbfd->direction = read_direction;

  if (! bfd_cache_init (nbfd))

    {

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

  return nbfd;

}

/*

FUNCTION

	bfd_openr_iovec

SYNOPSIS

        bfd *bfd_openr_iovec (const char *filename, const char *target,

                              void *(*open_func) (struct bfd *nbfd,

                                                  void *open_closure),

                              void *open_closure,

                              file_ptr (*pread_func) (struct bfd *nbfd,

                                                      void *stream,

                                                      void *buf,

                                                      file_ptr nbytes,

                                                      file_ptr offset),

                              int (*close_func) (struct bfd *nbfd,

                                                 void *stream),

			      int (*stat_func) (struct bfd *abfd,

					        void *stream,

					        struct stat *sb));

DESCRIPTION

        Create and return a BFD backed by a read-only @var{stream}.

        The @var{stream} is created using @var{open_func}, accessed using

        @var{pread_func} and destroyed using @var{close_func}.

	Calls <>, so @var{target} is interpreted as by

	that function.

	Calls @var{open_func} (which can call <> and

	<>) to obtain the read-only stream backing

	the BFD.  @var{open_func} either succeeds returning the

	non-<> @var{stream}, or fails returning <>

	(setting <>).

	Calls @var{pread_func} to request @var{nbytes} of data from

	@var{stream} starting at @var{offset} (e.g., via a call to

	<>).  @var{pread_func} either succeeds returning the

	number of bytes read (which can be less than @var{nbytes} when

	end-of-file), or fails returning -1 (setting <>).

	Calls @var{close_func} when the BFD is later closed using

	<>.  @var{close_func} either succeeds returning 0, or

	fails returning -1 (setting <>).

	Calls @var{stat_func} to fill in a stat structure for bfd_stat,

	bfd_get_size, and bfd_get_mtime calls.  @var{stat_func} returns 0

	on success, or returns -1 on failure (setting <>).

	If <> returns <> then an error has

	occurred.  Possible errors are <>,

	<> and <>.

	A copy of the @var{filename} argument is stored in the newly created

	BFD.  It can be accessed via the bfd_get_filename() macro.

*/

struct opncls

{

  void *stream;

  file_ptr (*pread) (struct bfd *abfd, void *stream, void *buf,

		     file_ptr nbytes, file_ptr offset);

  int (*close) (struct bfd *abfd, void *stream);

  int (*stat) (struct bfd *abfd, void *stream, struct stat *sb);

  file_ptr where;

};

static file_ptr

opncls_btell (struct bfd *abfd)

{

  struct opncls *vec = (struct opncls *) abfd->iostream;

  return vec->where;

}

static int

opncls_bseek (struct bfd *abfd, file_ptr offset, int whence)

{

  struct opncls *vec = (struct opncls *) abfd->iostream;

  switch (whence)

    {

    case SEEK_SET: vec->where = offset; break;

    case SEEK_CUR: vec->where += offset; break;

    case SEEK_END: return -1;

    }

  return 0;

}

static file_ptr

opncls_bread (struct bfd *abfd, void *buf, file_ptr nbytes)

{

  struct opncls *vec = (struct opncls *) abfd->iostream;

  file_ptr nread = (vec->pread) (abfd, vec->stream, buf, nbytes, vec->where);

  if (nread < 0)

    return nread;

  vec->where += nread;

  return nread;

}

static file_ptr

opncls_bwrite (struct bfd *abfd ATTRIBUTE_UNUSED,

	      const void *where ATTRIBUTE_UNUSED,

	      file_ptr nbytes ATTRIBUTE_UNUSED)

{

  return -1;

}

static int

opncls_bclose (struct bfd *abfd)

{

  struct opncls *vec = (struct opncls *) abfd->iostream;

  /* Since the VEC's memory is bound to the bfd deleting the bfd will

     free it.  */

  int status = 0;

  if (vec->close != NULL)

    status = (vec->close) (abfd, vec->stream);

  abfd->iostream = NULL;

  return status;

}

static int

opncls_bflush (struct bfd *abfd ATTRIBUTE_UNUSED)

{

  return 0;

}

static int

opncls_bstat (struct bfd *abfd, struct stat *sb)

{

  struct opncls *vec = (struct opncls *) abfd->iostream;

  memset (sb, 0, sizeof (*sb));

  if (vec->stat == NULL)

    return 0;

  return (vec->stat) (abfd, vec->stream, sb);

}

static void *

opncls_bmmap (struct bfd *abfd ATTRIBUTE_UNUSED,

	      void *addr ATTRIBUTE_UNUSED,

	      bfd_size_type len ATTRIBUTE_UNUSED,

	      int prot ATTRIBUTE_UNUSED,

	      int flags ATTRIBUTE_UNUSED,

	      file_ptr offset ATTRIBUTE_UNUSED,

              void **map_addr ATTRIBUTE_UNUSED,

              bfd_size_type *map_len ATTRIBUTE_UNUSED)

{

  return (void *) -1;

}

static const struct bfd_iovec opncls_iovec = {

  &opncls_bread, &opncls_bwrite, &opncls_btell, &opncls_bseek,

  &opncls_bclose, &opncls_bflush, &opncls_bstat, &opncls_bmmap

};

bfd *

bfd_openr_iovec (const char *filename, const char *target,

		 void *(*open_p) (struct bfd *, void *),

		 void *open_closure,

		 file_ptr (*pread_p) (struct bfd *, void *, void *,

				      file_ptr, file_ptr),

		 int (*close_p) (struct bfd *, void *),

		 int (*stat_p) (struct bfd *, void *, struct stat *))

{

  bfd *nbfd;

  const bfd_target *target_vec;

  struct opncls *vec;

  void *stream;

  nbfd = _bfd_new_bfd ();

  if (nbfd == NULL)

    return NULL;

  target_vec = bfd_find_target (target, nbfd);

  if (target_vec == NULL)

    {

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

  /* PR 11983: Do not cache the original filename, but

     rather make a copy - the original might go away.  */

  nbfd->filename = xstrdup (filename);

  nbfd->direction = read_direction;

  /* `open_p (...)' would get expanded by an the open(2) syscall macro.  */

  stream = (*open_p) (nbfd, open_closure);

  if (stream == NULL)

    {

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

  vec = (struct opncls *) bfd_zalloc (nbfd, sizeof (struct opncls));

  vec->stream = stream;

  vec->pread = pread_p;

  vec->close = close_p;

  vec->stat = stat_p;

  nbfd->iovec = &opncls_iovec;

  nbfd->iostream = vec;

  return nbfd;

}

/* bfd_openw -- open for writing.

   Returns a pointer to a freshly-allocated BFD on success, or NULL.

   See comment by bfd_fdopenr before you try to modify this function.  */

/*

FUNCTION

	bfd_openw

SYNOPSIS

	bfd *bfd_openw (const char *filename, const char *target);

DESCRIPTION

	Create a BFD, associated with file @var{filename}, using the

	file format @var{target}, and return a pointer to it.

	Possible errors are <>, <>,

	<>.

	A copy of the @var{filename} argument is stored in the newly created

	BFD.  It can be accessed via the bfd_get_filename() macro.

*/

bfd *

bfd_openw (const char *filename, const char *target)

{

  bfd *nbfd;

  const bfd_target *target_vec;

  /* nbfd has to point to head of malloc'ed block so that bfd_close may

     reclaim it correctly.  */

  nbfd = _bfd_new_bfd ();

  if (nbfd == NULL)

    return NULL;

  target_vec = bfd_find_target (target, nbfd);

  if (target_vec == NULL)

    {

      _bfd_delete_bfd (nbfd);

      return NULL;

    }

  /* PR 11983: Do not cache the original filename, but

     rather make a copy - the original might go away.  */

  nbfd->filename = xstrdup (filename);

  nbfd->direction = write_direction;

  if (bfd_open_file (nbfd) == NULL)

    {

      /* File not writeable, etc.  */

      bfd_set_error (bfd_error_system_call);

      _bfd_delete_bfd (nbfd);

      return NULL;

  }

  return nbfd;

}

static inline void

_maybe_make_executable (bfd * abfd)

{

  /* If the file was open for writing and is now executable,

     make it so.  */

  if (abfd->direction == write_direction

      && (abfd->flags & (EXEC_P | DYNAMIC)) != 0)

    {

      struct stat buf;

      if (stat (abfd->filename, &buf) == 0

	  /* Do not attempt to change non-regular files.  This is

	     here especially for configure scripts and kernel builds

	     which run tests with "ld [...] -o /dev/null".  */

	  && S_ISREG(buf.st_mode))

	{

/*

        unsigned int mask = umask (0);

        umask (mask);

        chmod (abfd->filename,

		 (0777

		  & (buf.st_mode | ((S_IXUSR | S_IXGRP | S_IXOTH) &~ mask))));

*/

	}

    }

}

/*

FUNCTION

	bfd_close

SYNOPSIS

	bfd_boolean bfd_close (bfd *abfd);

DESCRIPTION

	Close a BFD. If the BFD was open for writing, then pending

	operations are completed and the file written out and closed.

	If the created file is executable, then <> is called

	to mark it as such.

	All memory attached to the BFD is released.

	The file descriptor associated with the BFD is closed (even

	if it was passed in to BFD by <>).

RETURNS

	<> is returned if all is ok, otherwise <>.

*/

bfd_boolean

bfd_close (bfd *abfd)

{

  bfd_boolean ret;

  if (bfd_write_p (abfd))

    {

      if (! BFD_SEND_FMT (abfd, _bfd_write_contents, (abfd)))

	return FALSE;

    }

  if (! BFD_SEND (abfd, _close_and_cleanup, (abfd)))

    return FALSE;

  ret = abfd->iovec->bclose (abfd) == 0;

  if (ret)

    _maybe_make_executable (abfd);

  _bfd_delete_bfd (abfd);

  return ret;

}

/*

FUNCTION

	bfd_close_all_done

SYNOPSIS

	bfd_boolean bfd_close_all_done (bfd *);

DESCRIPTION

	Close a BFD.  Differs from <> since it does not

	complete any pending operations.  This routine would be used

	if the application had just used BFD for swapping and didn't

	want to use any of the writing code.

	If the created file is executable, then <> is called

	to mark it as such.

	All memory attached to the BFD is released.

RETURNS

	<> is returned if all is ok, otherwise <>.

*/

bfd_boolean

bfd_close_all_done (bfd *abfd)

{

  bfd_boolean ret;

  ret = bfd_cache_close (abfd);

  if (ret)

    _maybe_make_executable (abfd);

  _bfd_delete_bfd (abfd);

  return ret;

}

/*

FUNCTION

	bfd_create

SYNOPSIS

	bfd *bfd_create (const char *filename, bfd *templ);

DESCRIPTION

	Create a new BFD in the manner of <>, but without

	opening a file. The new BFD takes the target from the target

	used by @var{templ}. The format is always set to <>.

	A copy of the @var{filename} argument is stored in the newly created

	BFD.  It can be accessed via the bfd_get_filename() macro.

*/

bfd *

bfd_create (const char *filename, bfd *templ)

{

  bfd *nbfd;

  nbfd = _bfd_new_bfd ();

  if (nbfd == NULL)

    return NULL;

  /* PR 11983: Do not cache the original filename, but

     rather make a copy - the original might go away.  */

  nbfd->filename = xstrdup (filename);

  if (templ)

    nbfd->xvec = templ->xvec;

  nbfd->direction = no_direction;

  bfd_set_format (nbfd, bfd_object);

  return nbfd;

}

/*

FUNCTION

	bfd_make_writable

SYNOPSIS

	bfd_boolean bfd_make_writable (bfd *abfd);

DESCRIPTION

	Takes a BFD as created by <> and converts it

	into one like as returned by <>.  It does this

	by converting the BFD to BFD_IN_MEMORY.  It's assumed that

	you will call <> on this bfd later.

RETURNS

	<> is returned if all is ok, otherwise <>.

*/

bfd_boolean

bfd_make_writable (bfd *abfd)

{

  struct bfd_in_memory *bim;

  if (abfd->direction != no_direction)

    {

      bfd_set_error (bfd_error_invalid_operation);

      return FALSE;

    }

  bim = (struct bfd_in_memory *) bfd_malloc (sizeof (struct bfd_in_memory));

  if (bim == NULL)

    return FALSE;	/* bfd_error already set.  */

  abfd->iostream = bim;

  /* bfd_bwrite will grow these as needed.  */

  bim->size = 0;

  bim->buffer = 0;

  abfd->flags |= BFD_IN_MEMORY;

  abfd->iovec = &_bfd_memory_iovec;

  abfd->origin = 0;

  abfd->direction = write_direction;

  abfd->where = 0;

  return TRUE;

}

/*

FUNCTION

	bfd_make_readable

SYNOPSIS

	bfd_boolean bfd_make_readable (bfd *abfd);

DESCRIPTION

	Takes a BFD as created by <> and

	<> and converts it into one like as

	returned by <>.  It does this by writing the

	contents out to the memory buffer, then reversing the

	direction.

RETURNS

	<> is returned if all is ok, otherwise <>.  */

bfd_boolean

bfd_make_readable (bfd *abfd)

{

  if (abfd->direction != write_direction || !(abfd->flags & BFD_IN_MEMORY))

    {

      bfd_set_error (bfd_error_invalid_operation);

      return FALSE;

    }

  if (! BFD_SEND_FMT (abfd, _bfd_write_contents, (abfd)))

    return FALSE;

  if (! BFD_SEND (abfd, _close_and_cleanup, (abfd)))

    return FALSE;

  abfd->arch_info = &bfd_default_arch_struct;

  abfd->where = 0;

  abfd->format = bfd_unknown;

  abfd->my_archive = NULL;

  abfd->origin = 0;

  abfd->opened_once = FALSE;

  abfd->output_has_begun = FALSE;

  abfd->section_count = 0;

  abfd->usrdata = NULL;

  abfd->cacheable = FALSE;

  abfd->flags |= BFD_IN_MEMORY;

  abfd->mtime_set = FALSE;

  abfd->target_defaulted = TRUE;

  abfd->direction = read_direction;

  abfd->sections = 0;

  abfd->symcount = 0;

  abfd->outsymbols = 0;

  abfd->tdata.any = 0;

  bfd_section_list_clear (abfd);

  bfd_check_format (abfd, bfd_object);

  return TRUE;

}

/*

FUNCTION

	bfd_alloc

SYNOPSIS

	void *bfd_alloc (bfd *abfd, bfd_size_type wanted);

DESCRIPTION

	Allocate a block of @var{wanted} bytes of memory attached to

	<> and return a pointer to it.

*/

void *

bfd_alloc (bfd *abfd, bfd_size_type size)

{

  void *ret;

  unsigned long ul_size = (unsigned long) size;

  if (size != ul_size

      /* Note - although objalloc_alloc takes an unsigned long as its

	 argument, internally the size is treated as a signed long.  This can

	 lead to problems where, for example, a request to allocate -1 bytes

	 can result in just 1 byte being allocated, rather than

	 ((unsigned long) -1) bytes.  Also memory checkers will often

	 complain about attempts to allocate a negative amount of memory.

	 So to stop these problems we fail if the size is negative.  */

      || ((signed long) ul_size) < 0)

    {

      bfd_set_error (bfd_error_no_memory);

      return NULL;

    }

  ret = objalloc_alloc ((struct objalloc *) abfd->memory, ul_size);

  if (ret == NULL)

    bfd_set_error (bfd_error_no_memory);

  return ret;

}

/*

INTERNAL_FUNCTION

	bfd_alloc2

SYNOPSIS

	void *bfd_alloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size);

DESCRIPTION

	Allocate a block of @var{nmemb} elements of @var{size} bytes each

	of memory attached to <> and return a pointer to it.

*/

void *

bfd_alloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size)

{

  if ((nmemb | size) >= HALF_BFD_SIZE_TYPE

      && size != 0

      && nmemb > ~(bfd_size_type) 0 / size)

    {

      bfd_set_error (bfd_error_no_memory);

      return NULL;

    }

  return bfd_alloc (abfd, size * nmemb);

}

/*

FUNCTION

	bfd_zalloc

SYNOPSIS

	void *bfd_zalloc (bfd *abfd, bfd_size_type wanted);

DESCRIPTION

	Allocate a block of @var{wanted} bytes of zeroed memory

	attached to <> and return a pointer to it.

*/

void *

bfd_zalloc (bfd *abfd, bfd_size_type size)

{

  void *res;

  res = bfd_alloc (abfd, size);

  if (res)

    memset (res, 0, (size_t) size);

  return res;

}

/*

INTERNAL_FUNCTION

	bfd_zalloc2

SYNOPSIS

	void *bfd_zalloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size);

DESCRIPTION

	Allocate a block of @var{nmemb} elements of @var{size} bytes each

	of zeroed memory attached to <> and return a pointer to it.

*/

void *

bfd_zalloc2 (bfd *abfd, bfd_size_type nmemb, bfd_size_type size)

{

  void *res;

  if ((nmemb | size) >= HALF_BFD_SIZE_TYPE

      && size != 0

      && nmemb > ~(bfd_size_type) 0 / size)

    {

      bfd_set_error (bfd_error_no_memory);

      return NULL;

    }

  size *= nmemb;

  res = bfd_alloc (abfd, size);

  if (res)

    memset (res, 0, (size_t) size);

  return res;

}

/* Free a block allocated for a BFD.

   Note:  Also frees all more recently allocated blocks!  */

void

bfd_release (bfd *abfd, void *block)

{

  objalloc_free_block ((struct objalloc *) abfd->memory, block);

}

/*

   GNU Extension: separate debug-info files

   The idea here is that a special section called .gnu_debuglink might be

   embedded in a binary file, which indicates that some *other* file

   contains the real debugging information. This special section contains a

   filename and CRC32 checksum, which we read and resolve to another file,

   if it exists.

   This facilitates "optional" provision of debugging information, without

   having to provide two complete copies of every binary object (with and

   without debug symbols).  */

#define GNU_DEBUGLINK		".gnu_debuglink"

#define GNU_DEBUGALTLINK	".gnu_debugaltlink"

/*

FUNCTION

	bfd_calc_gnu_debuglink_crc32

SYNOPSIS

	unsigned long bfd_calc_gnu_debuglink_crc32

	  (unsigned long crc, const unsigned char *buf, bfd_size_type len);

DESCRIPTION

	Computes a CRC value as used in the .gnu_debuglink section.

	Advances the previously computed @var{crc} value by computing

	and adding in the crc32 for @var{len} bytes of @var{buf}.

RETURNS

	Return the updated CRC32 value.

*/

unsigned long

bfd_calc_gnu_debuglink_crc32 (unsigned long crc,

			      const unsigned char *buf,

			      bfd_size_type len)

{

  static const unsigned long crc32_table[256] =

    {

      0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,

      0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,

      0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,

      0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,

      0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,

      0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,

      0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,

      0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,

      0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,

      0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,

      0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,

      0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,

      0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,

      0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,

      0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,

      0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,