text: /* Copyright (C) 1993,1995,1997-2002, 2003, 2004, 2006, 2007, 2011-2012
     Free Software Foundation, Inc.
     This file is part of the GNU C Library.
  
     The GNU C Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) any later version.
  
     The GNU C Library 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
     Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public
     License along with the GNU C Library; if not, see
     <http://www.gnu.org/licenses/>.
  
     As a special exception, if you link the code in this file with
     files compiled with a GNU compiler to produce an executable,
     that does not cause the resulting executable to be covered by
     the GNU Lesser General Public License.  This exception does not
     however invalidate any other reasons why the executable file
     might be covered by the GNU Lesser General Public License.
     This exception applies to code released by its copyright holders
     in files containing the exception.  */
  
  /* Generic or default I/O operations. */
  
  #include "libioP.h"
  #include <stdlib.h>
  #include <string.h>
  #include <stdbool.h>
  #ifdef _LIBC
  #include <sched.h>
  #endif
  
  #ifdef _IO_MTSAFE_IO
  static _IO_lock_t list_all_lock = _IO_lock_initializer;
  #endif
  
  /* Used to signal modifications to the list of FILE decriptors.  */
  static int _IO_list_all_stamp;
  
  
  static _IO_FILE *run_fp;
  
  static void
  flush_cleanup (void *not_used)
  {
    if (run_fp != NULL)
      _IO_funlockfile (run_fp);
  #ifdef _IO_MTSAFE_IO
    _IO_lock_unlock (list_all_lock);
  #endif
  }
  
  void
  _IO_un_link (fp)
       struct _IO_FILE_plus *fp;
  {
    if (fp->file._flags & _IO_LINKED)
      {
        struct _IO_FILE **f;
  #ifdef _IO_MTSAFE_IO
        _IO_cleanup_region_start_noarg (flush_cleanup);
        _IO_lock_lock (list_all_lock);
        run_fp = (_IO_FILE *) fp;
        _IO_flockfile ((_IO_FILE *) fp);
  #endif
        if (_IO_list_all == NULL)
  	;
        else if (fp == _IO_list_all)
  	{
  	  _IO_list_all = (struct _IO_FILE_plus *) _IO_list_all->file._chain;
  	  ++_IO_list_all_stamp;
  	}
        else
  	for (f = &_IO_list_all->file._chain; *f; f = &(*f)->_chain)
  	  if (*f == (_IO_FILE *) fp)
  	    {
  	      *f = fp->file._chain;
  	      ++_IO_list_all_stamp;
  	      break;
  	    }
        fp->file._flags &= ~_IO_LINKED;
  #ifdef _IO_MTSAFE_IO
        _IO_funlockfile ((_IO_FILE *) fp);
        run_fp = NULL;
        _IO_lock_unlock (list_all_lock);
        _IO_cleanup_region_end (0);
  #endif
      }
  }
  libc_hidden_def (_IO_un_link)
  
  void
  _IO_link_in (fp)
       struct _IO_FILE_plus *fp;
  {
    if ((fp->file._flags & _IO_LINKED) == 0)
      {
        fp->file._flags |= _IO_LINKED;
  #ifdef _IO_MTSAFE_IO
        _IO_cleanup_region_start_noarg (flush_cleanup);
        _IO_lock_lock (list_all_lock);
        run_fp = (_IO_FILE *) fp;
        _IO_flockfile ((_IO_FILE *) fp);
  #endif
        fp->file._chain = (_IO_FILE *) _IO_list_all;
        _IO_list_all = fp;
        ++_IO_list_all_stamp;
  #ifdef _IO_MTSAFE_IO
        _IO_funlockfile ((_IO_FILE *) fp);
        run_fp = NULL;
        _IO_lock_unlock (list_all_lock);
        _IO_cleanup_region_end (0);
  #endif
      }
  }
  libc_hidden_def (_IO_link_in)
  
  /* Return minimum _pos markers
     Assumes the current get area is the main get area. */
  _IO_ssize_t _IO_least_marker (_IO_FILE *fp, char *end_p);
  
  _IO_ssize_t
  _IO_least_marker (fp, end_p)
       _IO_FILE *fp;
       char *end_p;
  {
    _IO_ssize_t least_so_far = end_p - fp->_IO_read_base;
    struct _IO_marker *mark;
    for (mark = fp->_markers; mark != NULL; mark = mark->_next)
      if (mark->_pos < least_so_far)
        least_so_far = mark->_pos;
    return least_so_far;
  }
  
  /* Switch current get area from backup buffer to (start of) main get area. */
  
  void
  _IO_switch_to_main_get_area (fp)
       _IO_FILE *fp;
  {
    char *tmp;
    fp->_flags &= ~_IO_IN_BACKUP;
    /* Swap _IO_read_end and _IO_save_end. */
    tmp = fp->_IO_read_end;
    fp->_IO_read_end = fp->_IO_save_end;
    fp->_IO_save_end= tmp;
    /* Swap _IO_read_base and _IO_save_base. */
    tmp = fp->_IO_read_base;
    fp->_IO_read_base = fp->_IO_save_base;
    fp->_IO_save_base = tmp;
    /* Set _IO_read_ptr. */
    fp->_IO_read_ptr = fp->_IO_read_base;
  }
  
  /* Switch current get area from main get area to (end of) backup area. */
  
  void
  _IO_switch_to_backup_area (fp)
       _IO_FILE *fp;
  {
    char *tmp;
    fp->_flags |= _IO_IN_BACKUP;
    /* Swap _IO_read_end and _IO_save_end. */
    tmp = fp->_IO_read_end;
    fp->_IO_read_end = fp->_IO_save_end;
    fp->_IO_save_end = tmp;
    /* Swap _IO_read_base and _IO_save_base. */
    tmp = fp->_IO_read_base;
    fp->_IO_read_base = fp->_IO_save_base;
    fp->_IO_save_base = tmp;
    /* Set _IO_read_ptr.  */
    fp->_IO_read_ptr = fp->_IO_read_end;
  }
  
  int
  _IO_switch_to_get_mode (fp)
       _IO_FILE *fp;
  {
    if (fp->_IO_write_ptr > fp->_IO_write_base)
      if (_IO_OVERFLOW (fp, EOF) == EOF)
        return EOF;
    if (_IO_in_backup (fp))
      fp->_IO_read_base = fp->_IO_backup_base;
    else
      {
        fp->_IO_read_base = fp->_IO_buf_base;
        if (fp->_IO_write_ptr > fp->_IO_read_end)
  	fp->_IO_read_end = fp->_IO_write_ptr;
      }
    fp->_IO_read_ptr = fp->_IO_write_ptr;
  
    fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = fp->_IO_read_ptr;
  
    fp->_flags &= ~_IO_CURRENTLY_PUTTING;
    return 0;
  }
  libc_hidden_def (_IO_switch_to_get_mode)
  
  void
  _IO_free_backup_area (fp)
       _IO_FILE *fp;
  {
    if (_IO_in_backup (fp))
      _IO_switch_to_main_get_area (fp);  /* Just in case. */
    free (fp->_IO_save_base);
    fp->_IO_save_base = NULL;
    fp->_IO_save_end = NULL;
    fp->_IO_backup_base = NULL;
  }
  libc_hidden_def (_IO_free_backup_area)
  
  #if 0
  int
  _IO_switch_to_put_mode (fp)
       _IO_FILE *fp;
  {
    fp->_IO_write_base = fp->_IO_read_ptr;
    fp->_IO_write_ptr = fp->_IO_read_ptr;
    /* Following is wrong if line- or un-buffered? */
    fp->_IO_write_end = (fp->_flags & _IO_IN_BACKUP
  		       ? fp->_IO_read_end : fp->_IO_buf_end);
  
    fp->_IO_read_ptr = fp->_IO_read_end;
    fp->_IO_read_base = fp->_IO_read_end;
  
    fp->_flags |= _IO_CURRENTLY_PUTTING;
    return 0;
  }
  #endif
  
  int
  __overflow (f, ch)
       _IO_FILE *f;
       int ch;
  {
    /* This is a single-byte stream.  */
    if (f->_mode == 0)
      _IO_fwide (f, -1);
    return _IO_OVERFLOW (f, ch);
  }
  libc_hidden_def (__overflow)
  
  static int save_for_backup (_IO_FILE *fp, char *end_p)
  #ifdef _LIBC
       internal_function
  #endif
       ;
  
  static int
  #ifdef _LIBC
  internal_function
  #endif
  save_for_backup (fp, end_p)
       _IO_FILE *fp;
       char *end_p;
  {
    /* Append [_IO_read_base..end_p] to backup area. */
    _IO_ssize_t least_mark = _IO_least_marker (fp, end_p);
    /* needed_size is how much space we need in the backup area. */
    _IO_size_t needed_size = (end_p - fp->_IO_read_base) - least_mark;
    /* FIXME: Dubious arithmetic if pointers are NULL */
    _IO_size_t current_Bsize = fp->_IO_save_end - fp->_IO_save_base;
    _IO_size_t avail; /* Extra space available for future expansion. */
    _IO_ssize_t delta;
    struct _IO_marker *mark;
    if (needed_size > current_Bsize)
      {
        char *new_buffer;
        avail = 100;
        new_buffer = (char *) malloc (avail + needed_size);
        if (new_buffer == NULL)
  	return EOF;		/* FIXME */
        if (least_mark < 0)
  	{
  #ifdef _LIBC
  	  __mempcpy (__mempcpy (new_buffer + avail,
  				fp->_IO_save_end + least_mark,
  				-least_mark),
  		     fp->_IO_read_base,
  		     end_p - fp->_IO_read_base);
  #else
  	  memcpy (new_buffer + avail,
  		  fp->_IO_save_end + least_mark,
  		  -least_mark);
  	  memcpy (new_buffer + avail - least_mark,
  		  fp->_IO_read_base,
  		  end_p - fp->_IO_read_base);
  #endif
  	}
        else
  	memcpy (new_buffer + avail,
  		fp->_IO_read_base + least_mark,
  		needed_size);
        free (fp->_IO_save_base);
        fp->_IO_save_base = new_buffer;
        fp->_IO_save_end = new_buffer + avail + needed_size;
      }
    else
      {
        avail = current_Bsize - needed_size;
        if (least_mark < 0)
  	{
  	  memmove (fp->_IO_save_base + avail,
  		   fp->_IO_save_end + least_mark,
  		   -least_mark);
  	  memcpy (fp->_IO_save_base + avail - least_mark,
  		  fp->_IO_read_base,
  		  end_p - fp->_IO_read_base);
  	}
        else if (needed_size > 0)
  	memcpy (fp->_IO_save_base + avail,
  		fp->_IO_read_base + least_mark,
  		needed_size);
      }
    fp->_IO_backup_base = fp->_IO_save_base + avail;
    /* Adjust all the streammarkers. */
    delta = end_p - fp->_IO_read_base;
    for (mark = fp->_markers; mark != NULL; mark = mark->_next)
      mark->_pos -= delta;
    return 0;
  }
  
  int
  __underflow (fp)
       _IO_FILE *fp;
  {
  #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
    if (_IO_vtable_offset (fp) == 0 && _IO_fwide (fp, -1) != -1)
      return EOF;
  #endif
  
    if (fp->_mode == 0)
      _IO_fwide (fp, -1);
    if (_IO_in_put_mode (fp))
      if (_IO_switch_to_get_mode (fp) == EOF)
        return EOF;
    if (fp->_IO_read_ptr < fp->_IO_read_end)
      return *(unsigned char *) fp->_IO_read_ptr;
    if (_IO_in_backup (fp))
      {
        _IO_switch_to_main_get_area (fp);
        if (fp->_IO_read_ptr < fp->_IO_read_end)
  	return *(unsigned char *) fp->_IO_read_ptr;
      }
    if (_IO_have_markers (fp))
      {
        if (save_for_backup (fp, fp->_IO_read_end))
  	return EOF;
      }
    else if (_IO_have_backup (fp))
      _IO_free_backup_area (fp);
    return _IO_UNDERFLOW (fp);
  }
  libc_hidden_def (__underflow)
  
  int
  __uflow (fp)
       _IO_FILE *fp;
  {
  #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
    if (_IO_vtable_offset (fp) == 0 && _IO_fwide (fp, -1) != -1)
      return EOF;
  #endif
  
    if (fp->_mode == 0)
      _IO_fwide (fp, -1);
    if (_IO_in_put_mode (fp))
      if (_IO_switch_to_get_mode (fp) == EOF)
        return EOF;
    if (fp->_IO_read_ptr < fp->_IO_read_end)
      return *(unsigned char *) fp->_IO_read_ptr++;
    if (_IO_in_backup (fp))
      {
        _IO_switch_to_main_get_area (fp);
        if (fp->_IO_read_ptr < fp->_IO_read_end)
  	return *(unsigned char *) fp->_IO_read_ptr++;
      }
    if (_IO_have_markers (fp))
      {
        if (save_for_backup (fp, fp->_IO_read_end))
  	return EOF;
      }
    else if (_IO_have_backup (fp))
      _IO_free_backup_area (fp);
    return _IO_UFLOW (fp);
  }
  libc_hidden_def (__uflow)
  
  void
  _IO_setb (f, b, eb, a)
       _IO_FILE *f;
       char *b;
       char *eb;
       int a;
  {
    if (f->_IO_buf_base && !(f->_flags & _IO_USER_BUF))
      FREE_BUF (f->_IO_buf_base, _IO_blen (f));
    f->_IO_buf_base = b;
    f->_IO_buf_end = eb;
    if (a)
      f->_flags &= ~_IO_USER_BUF;
    else
      f->_flags |= _IO_USER_BUF;
  }
  libc_hidden_def (_IO_setb)
  
  void
  _IO_doallocbuf (fp)
       _IO_FILE *fp;
  {
    if (fp->_IO_buf_base)
      return;
    if (!(fp->_flags & _IO_UNBUFFERED) || fp->_mode > 0)
      if (_IO_DOALLOCATE (fp) != EOF)
        return;
    _IO_setb (fp, fp->_shortbuf, fp->_shortbuf+1, 0);
  }
  libc_hidden_def (_IO_doallocbuf)
  
  int
  _IO_default_underflow (fp)
       _IO_FILE *fp;
  {
    return EOF;
  }
  
  int
  _IO_default_uflow (fp)
       _IO_FILE *fp;
  {
    int ch = _IO_UNDERFLOW (fp);
    if (ch == EOF)
      return EOF;
    return *(unsigned char *) fp->_IO_read_ptr++;
  }
  libc_hidden_def (_IO_default_uflow)
  
  _IO_size_t
  _IO_default_xsputn (f, data, n)
       _IO_FILE *f;
       const void *data;
       _IO_size_t n;
  {
    const char *s = (char *) data;
    _IO_size_t more = n;
    if (more <= 0)
      return 0;
    for (;;)
      {
        /* Space available. */
        if (f->_IO_write_ptr < f->_IO_write_end)
  	{
  	  _IO_size_t count = f->_IO_write_end - f->_IO_write_ptr;
  	  if (count > more)
  	    count = more;
  	  if (count > 20)
  	    {
  #ifdef _LIBC
  	      f->_IO_write_ptr = __mempcpy (f->_IO_write_ptr, s, count);
  #else
  	      memcpy (f->_IO_write_ptr, s, count);
  	      f->_IO_write_ptr += count;
  #endif
  	      s += count;
  	    }
  	  else if (count)
  	    {
  	      char *p = f->_IO_write_ptr;
  	      _IO_ssize_t i;
  	      for (i = count; --i >= 0; )
  		*p++ = *s++;
  	      f->_IO_write_ptr = p;
  	    }
  	  more -= count;
  	}
        if (more == 0 || _IO_OVERFLOW (f, (unsigned char) *s++) == EOF)
  	break;
        more--;
      }
    return n - more;
  }
  libc_hidden_def (_IO_default_xsputn)
  
  _IO_size_t
  _IO_sgetn (fp, data, n)
       _IO_FILE *fp;
       void *data;
       _IO_size_t n;
  {
    /* FIXME handle putback buffer here! */
    return _IO_XSGETN (fp, data, n);
  }
  libc_hidden_def (_IO_sgetn)
  
  _IO_size_t
  _IO_default_xsgetn (fp, data, n)
       _IO_FILE *fp;
       void *data;
       _IO_size_t n;
  {
    _IO_size_t more = n;
    char *s = (char*) data;
    for (;;)
      {
        /* Data available. */
        if (fp->_IO_read_ptr < fp->_IO_read_end)
  	{
  	  _IO_size_t count = fp->_IO_read_end - fp->_IO_read_ptr;
  	  if (count > more)
  	    count = more;
  	  if (count > 20)
  	    {
  #ifdef _LIBC
  	      s = __mempcpy (s, fp->_IO_read_ptr, count);
  #else
  	      memcpy (s, fp->_IO_read_ptr, count);
  	      s += count;
  #endif
  	      fp->_IO_read_ptr += count;
  	    }
  	  else if (count)
  	    {
  	      char *p = fp->_IO_read_ptr;
  	      int i = (int) count;
  	      while (--i >= 0)
  		*s++ = *p++;
  	      fp->_IO_read_ptr = p;
  	    }
  	    more -= count;
  	}
        if (more == 0 || __underflow (fp) == EOF)
  	break;
      }
    return n - more;
  }
  libc_hidden_def (_IO_default_xsgetn)
  
  #if 0
  /* Seems not to be needed. --drepper */
  int
  _IO_sync (fp)
       _IO_FILE *fp;
  {
    return 0;
  }
  #endif
  
  _IO_FILE *
  _IO_default_setbuf (fp, p, len)
       _IO_FILE *fp;
       char *p;
       _IO_ssize_t len;
  {
      if (_IO_SYNC (fp) == EOF)
  	return NULL;
      if (p == NULL || len == 0)
        {
  	fp->_flags |= _IO_UNBUFFERED;
  	_IO_setb (fp, fp->_shortbuf, fp->_shortbuf+1, 0);
        }
      else
        {
  	fp->_flags &= ~_IO_UNBUFFERED;
  	_IO_setb (fp, p, p+len, 0);
        }
      fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = 0;
      fp->_IO_read_base = fp->_IO_read_ptr = fp->_IO_read_end = 0;
      return fp;
  }
  
  _IO_off64_t
  _IO_default_seekpos (fp, pos, mode)
       _IO_FILE *fp;
       _IO_off64_t pos;
       int mode;
  {
    return _IO_SEEKOFF (fp, pos, 0, mode);
  }
  
  int
  _IO_default_doallocate (fp)
       _IO_FILE *fp;
  {
    char *buf;
  
    ALLOC_BUF (buf, _IO_BUFSIZ, EOF);
    _IO_setb (fp, buf, buf+_IO_BUFSIZ, 1);
    return 1;
  }
  libc_hidden_def (_IO_default_doallocate)
  
  void
  _IO_init (fp, flags)
       _IO_FILE *fp;
       int flags;
  {
    _IO_no_init (fp, flags, -1, NULL, NULL);
  }
  libc_hidden_def (_IO_init)
  
  void
  _IO_old_init (fp, flags)
       _IO_FILE *fp;
       int flags;
  {
    fp->_flags = _IO_MAGIC|flags;
    fp->_flags2 = 0;
    fp->_IO_buf_base = NULL;
    fp->_IO_buf_end = NULL;
    fp->_IO_read_base = NULL;
    fp->_IO_read_ptr = NULL;
    fp->_IO_read_end = NULL;
    fp->_IO_write_base = NULL;
    fp->_IO_write_ptr = NULL;
    fp->_IO_write_end = NULL;
    fp->_chain = NULL; /* Not necessary. */
  
    fp->_IO_save_base = NULL;
    fp->_IO_backup_base = NULL;
    fp->_IO_save_end = NULL;
    fp->_markers = NULL;
    fp->_cur_column = 0;
  #if _IO_JUMPS_OFFSET
    fp->_vtable_offset = 0;
  #endif
  #ifdef _IO_MTSAFE_IO
    if (fp->_lock != NULL)
      _IO_lock_init (*fp->_lock);
  #endif
  }
  
  void
  _IO_no_init (fp, flags, orientation, wd, jmp)
       _IO_FILE *fp;
       int flags;
       int orientation;
       struct _IO_wide_data *wd;
       const struct _IO_jump_t *jmp;
  {
    _IO_old_init (fp, flags);
    fp->_mode = orientation;
  #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
    if (orientation >= 0)
      {
        fp->_wide_data = wd;
        fp->_wide_data->_IO_buf_base = NULL;
        fp->_wide_data->_IO_buf_end = NULL;
        fp->_wide_data->_IO_read_base = NULL;
        fp->_wide_data->_IO_read_ptr = NULL;
        fp->_wide_data->_IO_read_end = NULL;
        fp->_wide_data->_IO_write_base = NULL;
        fp->_wide_data->_IO_write_ptr = NULL;
        fp->_wide_data->_IO_write_end = NULL;
        fp->_wide_data->_IO_save_base = NULL;
        fp->_wide_data->_IO_backup_base = NULL;
        fp->_wide_data->_IO_save_end = NULL;
  
        fp->_wide_data->_wide_vtable = jmp;
      }
  #endif
    fp->_freeres_list = NULL;
  }
  
  int
  _IO_default_sync (fp)
       _IO_FILE *fp;
  {
    return 0;
  }
  
  /* The way the C++ classes are mapped into the C functions in the
     current implementation, this function can get called twice! */
  
  void
  _IO_default_finish (fp, dummy)
       _IO_FILE *fp;
       int dummy;
  {
    struct _IO_marker *mark;
    if (fp->_IO_buf_base && !(fp->_flags & _IO_USER_BUF))
      {
        FREE_BUF (fp->_IO_buf_base, _IO_blen (fp));
        fp->_IO_buf_base = fp->_IO_buf_end = NULL;
      }
  
    for (mark = fp->_markers; mark != NULL; mark = mark->_next)
      mark->_sbuf = NULL;
  
    if (fp->_IO_save_base)
      {
        free (fp->_IO_save_base);
        fp->_IO_save_base = NULL;
      }
  
    _IO_un_link ((struct _IO_FILE_plus *) fp);
  
  #ifdef _IO_MTSAFE_IO
    if (fp->_lock != NULL)
      _IO_lock_fini (*fp->_lock);
  #endif
  }
  libc_hidden_def (_IO_default_finish)
  
  _IO_off64_t
  _IO_default_seekoff (fp, offset, dir, mode)
       _IO_FILE *fp;
       _IO_off64_t offset;
       int dir;
       int mode;
  {
    return _IO_pos_BAD;
  }
  
  int
  _IO_sputbackc (fp, c)
       _IO_FILE *fp;
       int c;
  {
    int result;
  
    if (fp->_IO_read_ptr > fp->_IO_read_base
        && (unsigned char)fp->_IO_read_ptr[-1] == (unsigned char)c)
      {
        fp->_IO_read_ptr--;
        result = (unsigned char) c;
      }
    else
      result = _IO_PBACKFAIL (fp, c);
  
    if (result != EOF)
      fp->_flags &= ~_IO_EOF_SEEN;
  
    return result;
  }
  libc_hidden_def (_IO_sputbackc)
  
  int
  _IO_sungetc (fp)
       _IO_FILE *fp;
  {
    int result;
  
    if (fp->_IO_read_ptr > fp->_IO_read_base)
      {
        fp->_IO_read_ptr--;
        result = (unsigned char) *fp->_IO_read_ptr;
      }
    else
      result = _IO_PBACKFAIL (fp, EOF);
  
    if (result != EOF)
      fp->_flags &= ~_IO_EOF_SEEN;
  
    return result;
  }
  
  #if 0 /* Work in progress */
  /* Seems not to be needed.  */
  #if 0
  void
  _IO_set_column (fp, c)
       _IO_FILE *fp;
       int c;
  {
    if (c == -1)
      fp->_column = -1;
    else
      fp->_column = c - (fp->_IO_write_ptr - fp->_IO_write_base);
  }
  #else
  int
  _IO_set_column (fp, i)
       _IO_FILE *fp;
       int i;
  {
    fp->_cur_column = i + 1;
    return 0;
  }
  #endif
  #endif
  
  
  unsigned
  _IO_adjust_column (start, line, count)
       unsigned start;
       const char *line;
       int count;
  {
    const char *ptr = line + count;
    while (ptr > line)
      if (*--ptr == '\n')
        return line + count - ptr - 1;
    return start + count;
  }
  libc_hidden_def (_IO_adjust_column)
  
  #if 0
  /* Seems not to be needed. --drepper */
  int
  _IO_get_column (fp)
       _IO_FILE *fp;
  {
    if (fp->_cur_column)
      return _IO_adjust_column (fp->_cur_column - 1,
  			      fp->_IO_write_base,
  			      fp->_IO_write_ptr - fp->_IO_write_base);
    return -1;
  }
  #endif
  
  
  int
  _IO_flush_all_lockp (int do_lock)
  {
    int result = 0;
    struct _IO_FILE *fp;
    int last_stamp;
  
  #ifdef _IO_MTSAFE_IO
    __libc_cleanup_region_start (do_lock, flush_cleanup, 0);
    if (do_lock)
      _IO_lock_lock (list_all_lock);
  #endif
  
    last_stamp = _IO_list_all_stamp;
    fp = (_IO_FILE *) _IO_list_all;
    while (fp != NULL)
      {
        run_fp = fp;
        if (do_lock)
  	_IO_flockfile (fp);
  
        if (((fp->_mode <= 0 && fp->_IO_write_ptr > fp->_IO_write_base)
  #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
  	   || (_IO_vtable_offset (fp) == 0
  	       && fp->_mode > 0 && (fp->_wide_data->_IO_write_ptr
  				    > fp->_wide_data->_IO_write_base))
  #endif
  	   )
  	  && _IO_OVERFLOW (fp, EOF) == EOF)
  	result = EOF;
  
        if (do_lock)
  	_IO_funlockfile (fp);
        run_fp = NULL;
  
        if (last_stamp != _IO_list_all_stamp)
  	{
  	  /* Something was added to the list.  Start all over again.  */
  	  fp = (_IO_FILE *) _IO_list_all;
  	  last_stamp = _IO_list_all_stamp;
  	}
        else
  	fp = fp->_chain;
      }
  
  #ifdef _IO_MTSAFE_IO
    if (do_lock)
      _IO_lock_unlock (list_all_lock);
    __libc_cleanup_region_end (0);
  #endif
  
    return result;
  }
  
  
  int
  _IO_flush_all ()
  {
    /* We want locking.  */
    return _IO_flush_all_lockp (1);
  }
  libc_hidden_def (_IO_flush_all)
  
  void
  _IO_flush_all_linebuffered ()
  {
    struct _IO_FILE *fp;
    int last_stamp;
  
  #ifdef _IO_MTSAFE_IO
    _IO_cleanup_region_start_noarg (flush_cleanup);
    _IO_lock_lock (list_all_lock);
  #endif
  
    last_stamp = _IO_list_all_stamp;
    fp = (_IO_FILE *) _IO_list_all;
    while (fp != NULL)
      {
        run_fp = fp;
        _IO_flockfile (fp);
  
        if ((fp->_flags & _IO_NO_WRITES) == 0 && fp->_flags & _IO_LINE_BUF)
  	_IO_OVERFLOW (fp, EOF);
  
        _IO_funlockfile (fp);
        run_fp = NULL;
  
        if (last_stamp != _IO_list_all_stamp)
  	{
  	  /* Something was added to the list.  Start all over again.  */
  	  fp = (_IO_FILE *) _IO_list_all;
  	  last_stamp = _IO_list_all_stamp;
  	}
        else
  	fp = fp->_chain;
      }
  
  #ifdef _IO_MTSAFE_IO
    _IO_lock_unlock (list_all_lock);
    _IO_cleanup_region_end (0);
  #endif
  }
  libc_hidden_def (_IO_flush_all_linebuffered)
  #ifdef _LIBC
  weak_alias (_IO_flush_all_linebuffered, _flushlbf)
  #endif
  
  
  /* The following is a bit tricky.  In general, we want to unbuffer the
     streams so that all output which follows is seen.  If we are not
     looking for memory leaks it does not make much sense to free the
     actual buffer because this will happen anyway once the program
     terminated.  If we do want to look for memory leaks we have to free
     the buffers.  Whether something is freed is determined by the
     function sin the libc_freeres section.  Those are called as part of
     the atexit routine, just like _IO_cleanup.  The problem is we do
     not know whether the freeres code is called first or _IO_cleanup.
     if the former is the case, we set the DEALLOC_BUFFER variable to
     true and _IO_unbuffer_write will take care of the rest.  If
     _IO_unbuffer_write is called first we add the streams to a list
     which the freeres function later can walk through.  */
  static void _IO_unbuffer_write (void);
  
  static bool dealloc_buffers;
  static _IO_FILE *freeres_list;
  
  static void
  _IO_unbuffer_write (void)
  {
    struct _IO_FILE *fp;
    for (fp = (_IO_FILE *) _IO_list_all; fp; fp = fp->_chain)
      {
        if (! (fp->_flags & _IO_UNBUFFERED)
  	  && (! (fp->_flags & _IO_NO_WRITES)
  	      || (fp->_flags & _IO_IS_APPENDING))
  	  /* Iff stream is un-orientated, it wasn't used. */
  	  && fp->_mode != 0)
  	{
  	  int cnt;
  #define MAXTRIES 2
  	  for (cnt = 0; cnt < MAXTRIES; ++cnt)
  	    if (fp->_lock == NULL || _IO_lock_trylock (*fp->_lock) == 0)
  	      break;
  	    else
  	      /* Give the other thread time to finish up its use of the
  		 stream.  */
  	      __sched_yield ();
  
  	  if (! dealloc_buffers && !(fp->_flags & _IO_USER_BUF))
  	    {
  	      fp->_flags |= _IO_USER_BUF;
  
  	      fp->_freeres_list = freeres_list;
  	      freeres_list = fp;
  	      fp->_freeres_buf = fp->_IO_buf_base;
  	      fp->_freeres_size = _IO_blen (fp);
  	    }
  
  	  _IO_SETBUF (fp, NULL, 0);
  
  	  if (cnt < MAXTRIES && fp->_lock != NULL)
  	    _IO_lock_unlock (*fp->_lock);
  	}
  
        /* Make sure that never again the wide char functions can be
  	 used.  */
        fp->_mode = -1;
      }
  }
  
  
  libc_freeres_fn (buffer_free)
  {
    dealloc_buffers = true;
  
    while (freeres_list != NULL)
      {
        FREE_BUF (freeres_list->_freeres_buf, freeres_list->_freeres_size);
  
        freeres_list = freeres_list->_freeres_list;
      }
  }
  
  
  int
  _IO_cleanup ()
  {
    /* We do *not* want locking.  Some threads might use streams but
       that is their problem, we flush them underneath them.  */
    int result = _IO_flush_all_lockp (0);
  
    /* We currently don't have a reliable mechanism for making sure that
       C++ static destructors are executed in the correct order.
       So it is possible that other static destructors might want to
       write to cout - and they're supposed to be able to do so.
  
       The following will make the standard streambufs be unbuffered,
       which forces any output from late destructors to be written out. */
    _IO_unbuffer_write ();
  
    return result;
  }
  
  
  void
  _IO_init_marker (marker, fp)
       struct _IO_marker *marker;
       _IO_FILE *fp;
  {
    marker->_sbuf = fp;
    if (_IO_in_put_mode (fp))
      _IO_switch_to_get_mode (fp);
    if (_IO_in_backup (fp))
      marker->_pos = fp->_IO_read_ptr - fp->_IO_read_end;
    else
      marker->_pos = fp->_IO_read_ptr - fp->_IO_read_base;
  
    /* Should perhaps sort the chain? */
    marker->_next = fp->_markers;
    fp->_markers = marker;
  }
  
  void
  _IO_remove_marker (marker)
       struct _IO_marker *marker;
  {
    /* Unlink from sb's chain. */
    struct _IO_marker **ptr = &marker->_sbuf->_markers;
    for (; ; ptr = &(*ptr)->_next)
      {
        if (*ptr == NULL)
  	break;
        else if (*ptr == marker)
  	{
  	  *ptr = marker->_next;
  	  return;
  	}
      }
  #if 0
      if _sbuf has a backup area that is no longer needed, should we delete
      it now, or wait until the next underflow?
  #endif
  }
  
  #define BAD_DELTA EOF
  
  int
  _IO_marker_difference (mark1, mark2)
       struct _IO_marker *mark1;
       struct _IO_marker *mark2;
  {
    return mark1->_pos - mark2->_pos;
  }
  
  /* Return difference between MARK and current position of MARK's stream. */
  int
  _IO_marker_delta (mark)
       struct _IO_marker *mark;
  {
    int cur_pos;
    if (mark->_sbuf == NULL)
      return BAD_DELTA;
    if (_IO_in_backup (mark->_sbuf))
      cur_pos = mark->_sbuf->_IO_read_ptr - mark->_sbuf->_IO_read_end;
    else
      cur_pos = mark->_sbuf->_IO_read_ptr - mark->_sbuf->_IO_read_base;
    return mark->_pos - cur_pos;
  }
  
  int
  _IO_seekmark (fp, mark, delta)
       _IO_FILE *fp;
       struct _IO_marker *mark;
       int delta;
  {
    if (mark->_sbuf != fp)
      return EOF;
   if (mark->_pos >= 0)
      {
        if (_IO_in_backup (fp))
  	_IO_switch_to_main_get_area (fp);
        fp->_IO_read_ptr = fp->_IO_read_base + mark->_pos;
      }
    else
      {
        if (!_IO_in_backup (fp))
  	_IO_switch_to_backup_area (fp);
        fp->_IO_read_ptr = fp->_IO_read_end + mark->_pos;
      }
    return 0;
  }
  
  void
  _IO_unsave_markers (fp)
       _IO_FILE *fp;
  {
    struct _IO_marker *mark = fp->_markers;
    if (mark)
      {
  #ifdef TODO
        streampos offset = seekoff (0, ios::cur, ios::in);
        if (offset != EOF)
  	{
  	  offset += eGptr () - Gbase ();
  	  for ( ; mark != NULL; mark = mark->_next)
  	    mark->set_streampos (mark->_pos + offset);
  	}
      else
        {
  	for ( ; mark != NULL; mark = mark->_next)
  	  mark->set_streampos (EOF);
        }
  #endif
        fp->_markers = 0;
      }
  
    if (_IO_have_backup (fp))
      _IO_free_backup_area (fp);
  }
  libc_hidden_def (_IO_unsave_markers)
  
  #if 0
  /* Seems not to be needed. --drepper */
  int
  _IO_nobackup_pbackfail (fp, c)
       _IO_FILE *fp;
       int c;
  {
    if (fp->_IO_read_ptr > fp->_IO_read_base)
  	fp->_IO_read_ptr--;
    if (c != EOF && *fp->_IO_read_ptr != c)
        *fp->_IO_read_ptr = c;
    return (unsigned char) c;
  }
  #endif
  
  int
  _IO_default_pbackfail (fp, c)
       _IO_FILE *fp;
       int c;
  {
    if (fp->_IO_read_ptr > fp->_IO_read_base && !_IO_in_backup (fp)
        && (unsigned char) fp->_IO_read_ptr[-1] == c)
      --fp->_IO_read_ptr;
    else
      {
        /* Need to handle a filebuf in write mode (switch to read mode). FIXME!*/
        if (!_IO_in_backup (fp))
  	{
  	  /* We need to keep the invariant that the main get area
  	     logically follows the backup area.  */
  	  if (fp->_IO_read_ptr > fp->_IO_read_base && _IO_have_backup (fp))
  	    {
  	      if (save_for_backup (fp, fp->_IO_read_ptr))
  		return EOF;
  	    }
  	  else if (!_IO_have_backup (fp))
  	    {
  	      /* No backup buffer: allocate one. */
  	      /* Use nshort buffer, if unused? (probably not)  FIXME */
  	      int backup_size = 128;
  	      char *bbuf = (char *) malloc (backup_size);
  	      if (bbuf == NULL)
  		return EOF;
  	      fp->_IO_save_base = bbuf;
  	      fp->_IO_save_end = fp->_IO_save_base + backup_size;
  	      fp->_IO_backup_base = fp->_IO_save_end;
  	    }
  	  fp->_IO_read_base = fp->_IO_read_ptr;
  	  _IO_switch_to_backup_area (fp);
  	}
        else if (fp->_IO_read_ptr <= fp->_IO_read_base)
  	{
  	  /* Increase size of existing backup buffer. */
  	  _IO_size_t new_size;
  	  _IO_size_t old_size = fp->_IO_read_end - fp->_IO_read_base;
  	  char *new_buf;
  	  new_size = 2 * old_size;
  	  new_buf = (char *) malloc (new_size);
  	  if (new_buf == NULL)
  	    return EOF;
  	  memcpy (new_buf + (new_size - old_size), fp->_IO_read_base,
  		  old_size);
  	  free (fp->_IO_read_base);
  	  _IO_setg (fp, new_buf, new_buf + (new_size - old_size),
  		    new_buf + new_size);
  	  fp->_IO_backup_base = fp->_IO_read_ptr;
  	}
  
        *--fp->_IO_read_ptr = c;
      }
    return (unsigned char) c;
  }
  libc_hidden_def (_IO_default_pbackfail)
  
  _IO_off64_t
  _IO_default_seek (fp, offset, dir)
       _IO_FILE *fp;
       _IO_off64_t offset;
       int dir;
  {
    return _IO_pos_BAD;
  }
  
  int
  _IO_default_stat (fp, st)
       _IO_FILE *fp;
       void* st;
  {
    return EOF;
  }
  
  _IO_ssize_t
  _IO_default_read (fp, data, n)
       _IO_FILE* fp;
       void *data;
       _IO_ssize_t n;
  {
    return -1;
  }
  
  _IO_ssize_t
  _IO_default_write (fp, data, n)
       _IO_FILE *fp;
       const void *data;
       _IO_ssize_t n;
  {
    return 0;
  }
  
  int
  _IO_default_showmanyc (fp)
       _IO_FILE *fp;
  {
    return -1;
  }
  
  void
  _IO_default_imbue (fp, locale)
       _IO_FILE *fp;
       void *locale;
  {
  }
  
  _IO_ITER
  _IO_iter_begin()
  {
    return (_IO_ITER) _IO_list_all;
  }
  libc_hidden_def (_IO_iter_begin)
  
  _IO_ITER
  _IO_iter_end()
  {
    return NULL;
  }
  libc_hidden_def (_IO_iter_end)
  
  _IO_ITER
  _IO_iter_next(iter)
      _IO_ITER iter;
  {
    return iter->_chain;
  }
  libc_hidden_def (_IO_iter_next)
  
  _IO_FILE *
  _IO_iter_file(iter)
      _IO_ITER iter;
  {
    return iter;
  }
  libc_hidden_def (_IO_iter_file)
  
  void
  _IO_list_lock()
  {
  #ifdef _IO_MTSAFE_IO
    _IO_lock_lock (list_all_lock);
  #endif
  }
  libc_hidden_def (_IO_list_lock)
  
  void
  _IO_list_unlock()
  {
  #ifdef _IO_MTSAFE_IO
    _IO_lock_unlock (list_all_lock);
  #endif
  }
  libc_hidden_def (_IO_list_unlock)
  
  void
  _IO_list_resetlock()
  {
  #ifdef _IO_MTSAFE_IO
    _IO_lock_init (list_all_lock);
  #endif
  }
  libc_hidden_def (_IO_list_resetlock)
  
  
  #ifdef TODO
  #if defined(linux)
  #define IO_CLEANUP ;
  #endif
  
  #ifdef IO_CLEANUP
    IO_CLEANUP
  #else
  struct __io_defs {
      __io_defs() { }
      ~__io_defs() { _IO_cleanup (); }
  };
  __io_defs io_defs__;
  #endif
  
  #endif /* TODO */
  
  #ifdef text_set_element
  text_set_element(__libc_atexit, _IO_cleanup);
  #endif
  