open.c

来自「gcc-fortran,linux使用fortran的编译软件。很好用的。」· C语言 代码 · 共 624 行 · 第 1/2 页

      goto fail;
    }

  switch (flags->status)
    {
    case STATUS_SCRATCH:
      if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) == 0)
	{
	  opp->file = NULL;
	  break;
	}

      generate_error (&opp->common, ERROR_BAD_OPTION,
		      "FILE parameter must not be present in OPEN statement");
      goto fail;

    case STATUS_OLD:
    case STATUS_NEW:
    case STATUS_REPLACE:
    case STATUS_UNKNOWN:
      if ((opp->common.flags & IOPARM_OPEN_HAS_FILE))
	break;

      opp->file = tmpname;
      opp->file_len = sprintf(opp->file, "fort.%d", opp->common.unit);
      break;

    default:
      internal_error (&opp->common, "new_unit(): Bad status");
    }

  /* Make sure the file isn't already open someplace else.
     Do not error if opening file preconnected to stdin, stdout, stderr.  */

  u2 = NULL;
  if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) != 0)
    u2 = find_file (opp->file, opp->file_len);
  if (u2 != NULL
      && (options.stdin_unit < 0 || u2->unit_number != options.stdin_unit)
      && (options.stdout_unit < 0 || u2->unit_number != options.stdout_unit)
      && (options.stderr_unit < 0 || u2->unit_number != options.stderr_unit))
    {
      unlock_unit (u2);
      generate_error (&opp->common, ERROR_ALREADY_OPEN, NULL);
      goto cleanup;
    }

  if (u2 != NULL)
    unlock_unit (u2);

  /* Open file.  */

  s = open_external (opp, flags);
  if (s == NULL)
    {
      generate_error (&opp->common, ERROR_OS, NULL);
      goto cleanup;
    }

  if (flags->status == STATUS_NEW || flags->status == STATUS_REPLACE)
    flags->status = STATUS_OLD;

  /* Create the unit structure.  */

  u->file = get_mem (opp->file_len);
  if (u->unit_number != opp->common.unit)
    internal_error (&opp->common, "Unit number changed");
  u->s = s;
  u->flags = *flags;
  u->read_bad = 0;
  u->endfile = NO_ENDFILE;
  u->last_record = 0;
  u->current_record = 0;
  u->mode = READING;
  u->maxrec = 0;
  u->bytes_left = 0;

  if (flags->position == POSITION_APPEND)
    {
      if (sseek (u->s, file_length (u->s)) == FAILURE)
	generate_error (&opp->common, ERROR_OS, NULL);
      u->endfile = AT_ENDFILE;
    }

  /* Unspecified recl ends up with a processor dependent value.  */

  if ((opp->common.flags & IOPARM_OPEN_HAS_RECL_IN))
    u->recl = opp->recl_in;
  else
    u->recl = max_offset;

  /* If the file is direct access, calculate the maximum record number
     via a division now instead of letting the multiplication overflow
     later.  */

  if (flags->access == ACCESS_DIRECT)
    u->maxrec = max_offset / u->recl;

  memmove (u->file, opp->file, opp->file_len);
  u->file_len = opp->file_len;

  /* Curiously, the standard requires that the
     position specifier be ignored for new files so a newly connected
     file starts out that the initial point.  We still need to figure
     out if the file is at the end or not.  */

  test_endfile (u);

  if (flags->status == STATUS_SCRATCH && opp->file != NULL)
    free_mem (opp->file);
  return u;

 cleanup:

  /* Free memory associated with a temporary filename.  */

  if (flags->status == STATUS_SCRATCH && opp->file != NULL)
    free_mem (opp->file);

 fail:

  close_unit (u);
  return NULL;
}


/* Open a unit which is already open.  This involves changing the
   modes or closing what is there now and opening the new file.  */

static void
already_open (st_parameter_open *opp, gfc_unit * u, unit_flags * flags)
{
  if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) == 0)
    {
      edit_modes (opp, u, flags);
      return;
    }

  /* If the file is connected to something else, close it and open a
     new unit.  */

  if (!compare_file_filename (u, opp->file, opp->file_len))
    {
#if !HAVE_UNLINK_OPEN_FILE
      char *path = NULL;
      if (u->file && u->flags.status == STATUS_SCRATCH)
	{
	  path = (char *) gfc_alloca (u->file_len + 1);
	  unpack_filename (path, u->file, u->file_len);
	}
#endif

      if (sclose (u->s) == FAILURE)
	{
	  unlock_unit (u);
	  generate_error (&opp->common, ERROR_OS,
			  "Error closing file in OPEN statement");
	  return;
	}

      u->s = NULL;
      if (u->file)
	free_mem (u->file);
      u->file = NULL;
      u->file_len = 0;

#if !HAVE_UNLINK_OPEN_FILE
      if (path != NULL)
	unlink (path);
#endif

      u = new_unit (opp, u, flags);
      if (u != NULL)
	unlock_unit (u);
      return;
    }

  edit_modes (opp, u, flags);
}


/* Open file.  */

extern void st_open (st_parameter_open *opp);
export_proto(st_open);

void
st_open (st_parameter_open *opp)
{
  unit_flags flags;
  gfc_unit *u = NULL;
  GFC_INTEGER_4 cf = opp->common.flags;
  unit_convert conv;
 
  library_start (&opp->common);

  /* Decode options.  */

  flags.access = !(cf & IOPARM_OPEN_HAS_ACCESS) ? ACCESS_UNSPECIFIED :
    find_option (&opp->common, opp->access, opp->access_len,
		 access_opt, "Bad ACCESS parameter in OPEN statement");

  flags.action = !(cf & IOPARM_OPEN_HAS_ACTION) ? ACTION_UNSPECIFIED :
    find_option (&opp->common, opp->action, opp->action_len,
		 action_opt, "Bad ACTION parameter in OPEN statement");

  flags.blank = !(cf & IOPARM_OPEN_HAS_BLANK) ? BLANK_UNSPECIFIED :
    find_option (&opp->common, opp->blank, opp->blank_len,
		 blank_opt, "Bad BLANK parameter in OPEN statement");

  flags.delim = !(cf & IOPARM_OPEN_HAS_DELIM) ? DELIM_UNSPECIFIED :
    find_option (&opp->common, opp->delim, opp->delim_len,
		 delim_opt, "Bad DELIM parameter in OPEN statement");

  flags.pad = !(cf & IOPARM_OPEN_HAS_PAD) ? PAD_UNSPECIFIED :
    find_option (&opp->common, opp->pad, opp->pad_len,
		 pad_opt, "Bad PAD parameter in OPEN statement");

  flags.form = !(cf & IOPARM_OPEN_HAS_FORM) ? FORM_UNSPECIFIED :
    find_option (&opp->common, opp->form, opp->form_len,
		 form_opt, "Bad FORM parameter in OPEN statement");

  flags.position = !(cf & IOPARM_OPEN_HAS_POSITION) ? POSITION_UNSPECIFIED :
    find_option (&opp->common, opp->position, opp->position_len,
		 position_opt, "Bad POSITION parameter in OPEN statement");

  flags.status = !(cf & IOPARM_OPEN_HAS_STATUS) ? STATUS_UNSPECIFIED :
    find_option (&opp->common, opp->status, opp->status_len,
		 status_opt, "Bad STATUS parameter in OPEN statement");

  /* First, we check wether the convert flag has been set via environment
     variable.  This overrides the convert tag in the open statement.  */

  conv = get_unformatted_convert (opp->common.unit);

  if (conv == CONVERT_NONE)
    {
      /* Nothing has been set by environment variable, check the convert tag.  */
      if (cf & IOPARM_OPEN_HAS_CONVERT)
	conv = find_option (&opp->common, opp->convert, opp->convert_len,
			    convert_opt,
			    "Bad CONVERT parameter in OPEN statement");
      else
	conv = compile_options.convert;
    }
  
  /* We use l8_to_l4_offset, which is 0 on little-endian machines
     and 1 on big-endian machines.  */
  switch (conv)
    {
    case CONVERT_NATIVE:
    case CONVERT_SWAP:
      break;
      
    case CONVERT_BIG:
      conv = l8_to_l4_offset ? CONVERT_NATIVE : CONVERT_SWAP;
      break;
      
    case CONVERT_LITTLE:
      conv = l8_to_l4_offset ? CONVERT_SWAP : CONVERT_NATIVE;
      break;
      
    default:
      internal_error (&opp->common, "Illegal value for CONVERT");
      break;
    }

  flags.convert = conv;

  if (opp->common.unit < 0)
    generate_error (&opp->common, ERROR_BAD_OPTION,
		    "Bad unit number in OPEN statement");

  if (flags.position != POSITION_UNSPECIFIED
      && flags.access == ACCESS_DIRECT)
    generate_error (&opp->common, ERROR_BAD_OPTION,
		    "Cannot use POSITION with direct access files");

  if (flags.access == ACCESS_APPEND)
    {
      if (flags.position != POSITION_UNSPECIFIED
	  && flags.position != POSITION_APPEND)
	generate_error (&opp->common, ERROR_BAD_OPTION,
			"Conflicting ACCESS and POSITION flags in"
			" OPEN statement");

      notify_std (GFC_STD_GNU,
		  "Extension: APPEND as a value for ACCESS in OPEN statement");
      flags.access = ACCESS_SEQUENTIAL;
      flags.position = POSITION_APPEND;
    }

  if (flags.position == POSITION_UNSPECIFIED)
    flags.position = POSITION_ASIS;

  if ((opp->common.flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_OK)
    {
      u = find_or_create_unit (opp->common.unit);

      if (u->s == NULL)
	{
	  u = new_unit (opp, u, &flags);
	  if (u != NULL)
	    unlock_unit (u);
	}
      else
	already_open (opp, u, &flags);
    }

  library_end ();
}