binutils-gdb/bfd/opncls.c

/* opncls.c -- open and close a BFD.
   Copyright (C) 1990-1991 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* $Id$ */

#include <sysdep.h>
#include "bfd.h"
#include "libbfd.h"
#include "obstack.h"
extern void bfd_cache_init();
FILE *bfd_open_file();

/* fdopen is a loser -- we should use stdio exclusively.  Unfortunately
   if we do that we can't use fcntl.  */

/** Locking 

   Locking is loosely controlled by the preprocessor variable
   BFD_LOCKS.  I say loosely because Unix barely understands locking
   -- at least in BSD it doesn't affect programs which don't
   explicitly use it!  That is to say it's practically useless, though
   if everyone uses this library you'll be OK.

   From among the many and varied lock facilities available, (none of
   which, of course, knows about any other) we use the fcntl locks,
   because they're Posix.

   The reason that @code{bfd_openr} and @code{bfd_fdopenr} exist, yet
   only @code{bfd_openw} exists is because of locking.  When we do
   output, we lock the filename file for output, then open a temporary
   file which does not actually get its correct filename until closing
   time.  This is safest, but requires the asymmetry in read and write
   entry points.

   Perhaps, since unix has so many different kinds of locking anyway,
   we should use the emacs lock scheme?... */

#define obstack_chunk_alloc malloc
#define obstack_chunk_free free

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

bfd *new_bfd()
{
  bfd *nbfd;

  nbfd = (bfd *)zalloc (sizeof (bfd));
  if (!nbfd)
    return 0;

  obstack_begin((PTR)&nbfd->memory, 128);
  
  nbfd->direction = no_direction;
  nbfd->iostream = NULL;
  nbfd->where = 0;
  nbfd->sections = (asection *)NULL;
  nbfd->format = bfd_unknown;
  nbfd->my_archive = (bfd *)NULL;
  nbfd->origin = 0;				   
  nbfd->opened_once = false;
  nbfd->output_has_begun = false;
  nbfd->section_count = 0;
  nbfd->usrdata = (PTR)NULL;
  nbfd->sections = (asection *)NULL;
  nbfd->cacheable = false;
  nbfd->flags = NO_FLAGS;
  nbfd->mtime_set = 0;
  return nbfd;
}

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

bfd *new_bfd_contained_in(obfd)
bfd *obfd;
{
	bfd *nbfd = new_bfd();
	nbfd->xvec = obfd->xvec;
	nbfd->my_archive = obfd;
	nbfd->direction = read_direction;
	return nbfd;
}

/*doc*
@section Opening and Closing BFDs

*/
/*proto*
*i bfd_openr
Opens the file supplied (using @code{fopen}) with the target supplied, it
returns a pointer to the created BFD.

If NULL is returned then an error has occured.
Possible errors are no_memory, invalid_target or system_call error.
*; PROTO(bfd*, bfd_openr, (CONST char *filename,CONST char*target));
*-*/

bfd *
DEFUN(bfd_openr, (filename, target),
      CONST char *filename AND
      CONST char *target)
{
  bfd *nbfd;
  bfd_target *target_vec;

  nbfd = new_bfd();
  if (nbfd == NULL) {
    bfd_error = no_memory;
    return NULL;
  }

  target_vec = bfd_find_target (target, nbfd);
  if (target_vec == NULL) {
    bfd_error = invalid_target;
    return NULL;
  }

  nbfd->filename = filename;
  nbfd->direction = read_direction; 

  if (bfd_open_file (nbfd) == NULL) {
    bfd_error = system_call_error;	/* File didn't exist, or some such */
    bfd_release(nbfd,0);
    return NULL;
  }
  return nbfd;
}


/* 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.
 */
/*proto*
*i bfd_fdopenr
bfd_fdopenr is to bfd_fopenr much like  fdopen is to fopen. It opens a BFD on
a file already described by the @var{fd} supplied. 

Possible errors are no_memory, invalid_target and system_call error.
*;  PROTO(bfd *, bfd_fdopenr,
    (CONST char *filename, CONST char *target, int fd));
*-*/

bfd *
DEFUN(bfd_fdopenr,(filename, target, fd),
      CONST char *filename AND
      CONST char *target AND
      int fd)
{
  bfd *nbfd;
  bfd_target *target_vec;
  int fdflags;
#ifdef BFD_LOCKS
  struct flock lock, *lockp = &lock;
#endif

  bfd_error = system_call_error;
  
  fdflags = fcntl (fd, F_GETFL, NULL);
  if (fdflags == -1) return NULL;

#ifdef BFD_LOCKS
  lockp->l_type = F_RDLCK;
  if (fcntl (fd, F_SETLKW, lockp) == -1) return NULL;
#endif

  nbfd = new_bfd();

  if (nbfd == NULL) {
    bfd_error = no_memory;
    return NULL;
  }

  target_vec = bfd_find_target (target, nbfd);
  if (target_vec == NULL) {
    bfd_error = invalid_target;
    return NULL;
  }

#ifdef BFD_LOCKS
  nbfd->lock = (struct flock *) (nbfd + 1);
#endif
  /* if the fd were open for read only, this still would not hurt: */
  nbfd->iostream = (char *) fdopen (fd, "r+"); 
  if (nbfd->iostream == NULL) {
    (void) obstack_free (&nbfd->memory, (PTR)0);
    return NULL;
  }
  
  /* OK, put everything where it belongs */

  nbfd->filename = filename;

  /* As a special case we allow a FD open for read/write to
     be written through, although doing so requires that we end
     the previous clause with a preposition.  */
  switch (fdflags & O_ACCMODE) {
  case O_RDONLY: nbfd->direction = read_direction; break;
  case O_WRONLY: nbfd->direction = write_direction; break;  
  case O_RDWR: nbfd->direction = both_direction; break;
  default: abort ();
  }
				   
#ifdef BFD_LOCKS
  memcpy (nbfd->lock, lockp, sizeof (struct flock))
#endif

  bfd_cache_init (nbfd);

  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. */

/*proto* bfd_openw
Creates a BFD, associated with file @var{filename}, using the file
format @var{target}, and returns a pointer to it.

Possible errors are system_call_error, no_memory, invalid_target.
*; PROTO(bfd *, bfd_openw, (CONST char *filename, CONST char *target));
*/

bfd *
DEFUN(bfd_openw,(filename, target),
      CONST char *filename AND
      CONST char *target)
{
  bfd *nbfd;
  bfd_target *target_vec;
  
  bfd_error = system_call_error;

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

  nbfd = new_bfd();
  if (nbfd == NULL) {
    bfd_error = no_memory;
    return NULL;
  }

  target_vec = bfd_find_target (target, nbfd);
  if (target_vec == NULL) return NULL;

  nbfd->filename = filename;
  nbfd->direction = write_direction;

  if (bfd_open_file (nbfd) == NULL) {
    bfd_error = system_call_error;	/* File not writeable, etc */
    (void) obstack_free (&nbfd->memory, (PTR)0);
    return NULL;
  }
  return nbfd;
}

/*proto* bfd_close
This function closes 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 @code{chmod} is called to mark
it as such.

All memory attached to the BFD's obstacks is released. 

@code{true} is returned if all is ok, otherwise @code{false}.
*; PROTO(boolean, bfd_close,(bfd *));
*/

boolean
DEFUN(bfd_close,(abfd),
      bfd *abfd)
{
  if (!bfd_read_p(abfd))
    if (BFD_SEND_FMT (abfd, _bfd_write_contents, (abfd)) != true)
      return false;

  if (BFD_SEND (abfd, _close_and_cleanup, (abfd)) != true) return false;

  bfd_cache_close(abfd);

  /* If the file was open for writing and is now executable,
     make it so */
  if (abfd->direction == write_direction 
      && abfd->flags & EXEC_P) {
    struct stat buf;
    stat(abfd->filename, &buf);
#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

    chmod(abfd->filename,buf.st_mode | S_IXUSR | S_IXGRP | S_IXOTH);
  }
  (void) obstack_free (&abfd->memory, (PTR)0);
  /* FIXME, shouldn't we de-allocate the bfd as well? */
  return true;
}

/*proto* bfd_create
This routine creates a new BFD in the manner of @code{bfd_openw}, but without
opening a file. The new BFD takes the target from the target used by
@var{template}. The format is always set to @code{bfd_object}.

*; PROTO(bfd *, bfd_create, (CONST char *filename, bfd *template));
*/

bfd *
DEFUN(bfd_create,(filename, template),
      CONST char *filename AND
      bfd *template)
{
  bfd *nbfd = new_bfd();
  if (nbfd == (bfd *)NULL) {
    bfd_error = no_memory;
    return (bfd *)NULL;
  }
  nbfd->filename = filename;
  if(template) {
    nbfd->xvec = template->xvec;
  }
  nbfd->direction = no_direction;
  bfd_set_format(nbfd, bfd_object);
  return nbfd;
}

/* Memory allocation */

DEFUN(PTR bfd_alloc_by_size_t,(abfd, size),
      bfd *abfd AND
      size_t size)
{
  PTR res = obstack_alloc(&(abfd->memory), size);
  return res;
}

DEFUN(void bfd_alloc_grow,(abfd, ptr, size),
      bfd *abfd AND
      PTR ptr AND
      bfd_size_type size)
{
  (void)   obstack_grow(&(abfd->memory), ptr, size);
}
DEFUN(PTR bfd_alloc_finish,(abfd),
      bfd *abfd)
{
  return obstack_finish(&(abfd->memory));
}

DEFUN(PTR bfd_alloc, (abfd, size),
      bfd *abfd AND
      bfd_size_type size)
{
  return bfd_alloc_by_size_t(abfd, (size_t)size);
}

DEFUN(PTR bfd_zalloc,(abfd, size),
      bfd *abfd AND
      bfd_size_type size)
{
  PTR res = bfd_alloc(abfd, size);
  memset(res, 0, (size_t)size);
  return res;
}

DEFUN(PTR bfd_realloc,(abfd, old, size),
      bfd *abfd AND
      PTR old AND
      bfd_size_type size)
{
  PTR res = bfd_alloc(abfd, size);
  memcpy(res, old, (size_t)size);
  return res;
}

/*proto* bfd_alloc_size
Return the number of bytes in the obstacks connected to the supplied
BFD.
*; PROTO(bfd_size_type,bfd_alloc_size,(bfd *abfd));
*/

bfd_size_type
DEFUN( bfd_alloc_size,(abfd),
      bfd *abfd)
{
  struct _obstack_chunk *chunk = abfd->memory.chunk;
  size_t size = 0;
  while (chunk) {
    size += chunk->limit - &(chunk->contents[0]);
    chunk = chunk->prev;
  }
  return size;
}