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-rw-r--r--libio/wgenops.c747
1 files changed, 747 insertions, 0 deletions
diff --git a/libio/wgenops.c b/libio/wgenops.c
new file mode 100644
index 0000000000..496d080014
--- /dev/null
+++ b/libio/wgenops.c
@@ -0,0 +1,747 @@
+/* Copyright (C) 1993, 1995, 1997, 1998, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU IO Library.
+   Written by Ulrich Drepper <drepper@cygnus.com>.
+   Based on the single byte version by Per Bothner <bothner@cygnus.com>.
+
+   This library 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, or (at
+   your option) any later version.
+
+   This 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
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this library; see the file COPYING.  If not, write to
+   the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   As a special exception, if you link this library with files
+   compiled with a GNU compiler to produce an executable, this does
+   not cause the resulting executable to be covered by the GNU General
+   Public License.  This exception does not however invalidate any
+   other reasons why the executable file might be covered by the GNU
+   General Public License.  */
+
+/* Generic or default I/O operations. */
+
+#include "libioP.h"
+#ifdef __STDC__
+#include <stdlib.h>
+#endif
+#include <string.h>
+#include <wchar.h>
+
+
+
+static int save_for_wbackup __P ((_IO_FILE *fp, wchar_t *end_p))
+#ifdef _LIBC
+     internal_function
+#endif
+     ;
+
+/* Return minimum _pos markers
+   Assumes the current get area is the main get area. */
+_IO_ssize_t _IO_least_wmarker __P ((_IO_FILE *fp, wchar_t *end_p));
+
+_IO_ssize_t
+_IO_least_wmarker (fp, end_p)
+     _IO_FILE *fp;
+     wchar_t *end_p;
+{
+  _IO_ssize_t least_so_far = end_p - fp->_wide_data->_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_wget_area (fp)
+     _IO_FILE *fp;
+{
+  wchar_t *tmp;
+  fp->_flags &= ~_IO_IN_BACKUP;
+  /* Swap _IO_read_end and _IO_save_end. */
+  tmp = fp->_wide_data->_IO_read_end;
+  fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_save_end;
+  fp->_wide_data->_IO_save_end= tmp;
+  /* Swap _IO_read_base and _IO_save_base. */
+  tmp = fp->_wide_data->_IO_read_base;
+  fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_save_base;
+  fp->_wide_data->_IO_save_base = tmp;
+  /* Set _IO_read_ptr. */
+  fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_base;
+}
+
+
+/* Switch current get area from main get area to (end of) backup area. */
+void
+_IO_switch_to_wbackup_area (fp)
+     _IO_FILE *fp;
+{
+  wchar_t *tmp;
+  fp->_flags |= _IO_IN_BACKUP;
+  /* Swap _IO_read_end and _IO_save_end. */
+  tmp = fp->_wide_data->_IO_read_end;
+  fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_save_end;
+  fp->_wide_data->_IO_save_end = tmp;
+  /* Swap _IO_read_base and _IO_save_base. */
+  tmp = fp->_wide_data->_IO_read_base;
+  fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_save_base;
+  fp->_wide_data->_IO_save_base = tmp;
+  /* Set _IO_read_ptr.  */
+  fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
+}
+
+
+void
+_IO_wsetb (f, b, eb, a)
+     _IO_FILE *f;
+     wchar_t *b;
+     wchar_t *eb;
+     int a;
+{
+  if (f->_wide_data->_IO_buf_base && !(f->_flags & _IO_USER_BUF))
+    FREE_BUF (f->_wide_data->_IO_buf_base, _IO_wblen (f));
+  f->_wide_data->_IO_buf_base = b;
+  f->_wide_data->_IO_buf_end = eb;
+  if (a)
+    f->_flags &= ~_IO_USER_BUF;
+  else
+    f->_flags |= _IO_USER_BUF;
+}
+
+
+wint_t
+_IO_wdefault_pbackfail (fp, c)
+     _IO_FILE *fp;
+     wint_t c;
+{
+  if (fp->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base
+      && !_IO_in_backup (fp)
+      && (wint_t) 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->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base
+	      && _IO_have_wbackup (fp))
+	    {
+	      if (save_for_wbackup (fp, fp->_wide_data->_IO_read_ptr))
+		return WEOF;
+	    }
+	  else if (!_IO_have_wbackup (fp))
+	    {
+	      /* No backup buffer: allocate one. */
+	      /* Use nshort buffer, if unused? (probably not)  FIXME */
+	      int backup_size = 128;
+	      wchar_t *bbuf = (wchar_t *) malloc (backup_size
+						  * sizeof (wchar_t));
+	      if (bbuf == NULL)
+		return WEOF;
+	      fp->_wide_data->_IO_save_base = bbuf;
+	      fp->_wide_data->_IO_save_end = (fp->_wide_data->_IO_save_base
+					      + backup_size);
+	      fp->_wide_data->_IO_backup_base = fp->_wide_data->_IO_save_end;
+	    }
+	  fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_ptr;
+	  _IO_switch_to_wbackup_area (fp);
+	}
+      else if (fp->_wide_data->_IO_read_ptr <= fp->_wide_data->_IO_read_base)
+	{
+	  /* Increase size of existing backup buffer. */
+	  _IO_size_t new_size;
+	  _IO_size_t old_size = (fp->_wide_data->_IO_read_end
+				 - fp->_wide_data->_IO_read_base);
+	  wchar_t *new_buf;
+	  new_size = 2 * old_size;
+	  new_buf = (wchar_t *) malloc (new_size * sizeof (wchar_t));
+	  if (new_buf == NULL)
+	    return WEOF;
+	  __wmemcpy (new_buf + (new_size - old_size),
+		     fp->_wide_data->_IO_read_base, old_size);
+	  free (fp->_wide_data->_IO_read_base);
+	  _IO_wsetg (fp, new_buf, new_buf + (new_size - old_size),
+		     new_buf + new_size);
+	  fp->_wide_data->_IO_backup_base = fp->_wide_data->_IO_read_ptr;
+	}
+
+      *--fp->_wide_data->_IO_read_ptr = c;
+    }
+  return c;
+}
+
+
+void
+_IO_wdefault_finish (fp, dummy)
+     _IO_FILE *fp;
+     int dummy;
+{
+  struct _IO_marker *mark;
+  if (fp->_wide_data->_IO_buf_base && !(fp->_flags & _IO_USER_BUF))
+    {
+      FREE_BUF (fp->_wide_data->_IO_buf_base,
+		_IO_wblen (fp) * sizeof (wchar_t));
+      fp->_wide_data->_IO_buf_base = fp->_wide_data->_IO_buf_end = NULL;
+    }
+
+  for (mark = fp->_markers; mark != NULL; mark = mark->_next)
+    mark->_sbuf = NULL;
+
+  if (fp->_IO_save_base)
+    {
+      free (fp->_wide_data->_IO_save_base);
+      fp->_IO_save_base = NULL;
+    }
+
+#ifdef _IO_MTSAFE_IO
+  _IO_lock_fini (*fp->_lock);
+#endif
+
+  _IO_un_link (fp);
+}
+
+
+wint_t
+_IO_wdefault_uflow (fp)
+     _IO_FILE *fp;
+{
+  wint_t wch;
+  wch = _IO_UNDERFLOW (fp);
+  if (wch == WEOF)
+    return WEOF;
+  return *fp->_wide_data->_IO_read_ptr++;
+}
+
+
+wint_t
+__woverflow (f, wch)
+     _IO_FILE *f;
+     wint_t wch;
+{
+  if (f->_mode == 0)
+    _IO_fwide (f, 1);
+  return _IO_OVERFLOW (f, wch);
+}
+
+
+wint_t
+__wuflow (fp)
+     _IO_FILE *fp;
+{
+  if (fp->_mode < 0 || (fp->_mode == 0 && _IO_fwide (fp, 1) != 1))
+    return EOF;
+
+  if (fp->_mode == 0)
+    _IO_fwide (fp, 1);
+  if (_IO_in_put_mode (fp))
+    if (_IO_switch_to_get_mode (fp) == EOF)
+      return WEOF;
+  if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
+    return *fp->_wide_data->_IO_read_ptr++;
+  if (_IO_in_backup (fp))
+    {
+      _IO_switch_to_main_wget_area (fp);
+      if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
+	return *fp->_wide_data->_IO_read_ptr++;
+    }
+  if (_IO_have_markers (fp))
+    {
+      if (save_for_wbackup (fp, fp->_wide_data->_IO_read_end))
+	return WEOF;
+    }
+  else if (_IO_have_wbackup (fp))
+    _IO_free_wbackup_area (fp);
+  return _IO_UFLOW (fp);
+}
+
+
+wint_t
+__wunderflow (fp)
+     _IO_FILE *fp;
+{
+  if (fp->_mode < 0 || (fp->_mode == 0 && _IO_fwide (fp, 1) != 1))
+    return EOF;
+
+  if (_IO_in_put_mode (fp))
+    if (_IO_switch_to_wget_mode (fp) == WEOF)
+      return WEOF;
+  if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
+    return *fp->_wide_data->_IO_read_ptr;
+  if (_IO_in_backup (fp))
+    {
+      _IO_switch_to_main_wget_area (fp);
+      if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
+	return *fp->_wide_data->_IO_read_ptr;
+    }
+  if (_IO_have_markers (fp))
+    {
+      if (save_for_wbackup (fp, fp->_wide_data->_IO_read_end))
+	return EOF;
+    }
+  else if (_IO_have_backup (fp))
+    _IO_free_wbackup_area (fp);
+  return _IO_UNDERFLOW (fp);
+}
+
+
+_IO_size_t
+_IO_wdefault_xsputn (f, data, n)
+     _IO_FILE *f;
+     const void *data;
+     _IO_size_t n;
+{
+  const wchar_t *s = (const wchar_t *) data;
+  _IO_size_t more = n;
+  if (more <= 0)
+    return 0;
+  for (;;)
+    {
+      /* Space available. */
+      _IO_ssize_t count = (f->_wide_data->_IO_write_end
+			   - f->_wide_data->_IO_write_ptr);
+      if (count > 0)
+	{
+	  if ((_IO_size_t) count > more)
+	    count = more;
+	  if (count > 20)
+	    {
+#ifdef _LIBC
+	      f->_wide_data->_IO_write_ptr =
+		__wmempcpy (f->_wide_data->_IO_write_ptr, s, count);
+#else
+	      memcpy (f->_wide_data->_IO_write_ptr, s, count);
+	      f->_wide_data->_IO_write_ptr += count;
+#endif
+	      s += count;
+            }
+	  else if (count <= 0)
+	    count = 0;
+	  else
+	    {
+	      wchar_t *p = f->_wide_data->_IO_write_ptr;
+	      _IO_ssize_t i;
+	      for (i = count; --i >= 0; )
+		*p++ = *s++;
+	      f->_wide_data->_IO_write_ptr = p;
+            }
+	  more -= count;
+        }
+      if (more == 0 || __woverflow (f, *s++) == WEOF)
+	break;
+      more--;
+    }
+  return n - more;
+}
+
+
+_IO_size_t
+_IO_wdefault_xsgetn (fp, data, n)
+     _IO_FILE *fp;
+     void *data;
+     _IO_size_t n;
+{
+  _IO_size_t more = n;
+  wchar_t *s = (wchar_t*) data;
+  for (;;)
+    {
+      /* Data available. */
+      _IO_ssize_t count = (fp->_wide_data->_IO_read_end
+			   - fp->_wide_data->_IO_read_ptr);
+      if (count > 0)
+	{
+	  if ((_IO_size_t) count > more)
+	    count = more;
+	  if (count > 20)
+	    {
+#ifdef _LIBC
+	      s = __wmempcpy (s, fp->_wide_data->_IO_read_ptr, count);
+#else
+	      memcpy (s, fp->_wide_data->_IO_read_ptr, count);
+	      s += count;
+#endif
+	      fp->_wide_data->_IO_read_ptr += count;
+	    }
+	  else if (count <= 0)
+	    count = 0;
+	  else
+	    {
+	      wchar_t *p = fp->_wide_data->_IO_read_ptr;
+	      int i = (int) count;
+	      while (--i >= 0)
+		*s++ = *p++;
+	      fp->_wide_data->_IO_read_ptr = p;
+            }
+            more -= count;
+        }
+      if (more == 0 || __wunderflow (fp) == WEOF)
+	break;
+    }
+  return n - more;
+}
+
+
+void
+_IO_wdoallocbuf (fp)
+     _IO_FILE *fp;
+{
+  if (fp->_wide_data->_IO_buf_base)
+    return;
+  if (!(fp->_flags & _IO_UNBUFFERED))
+    if (_IO_DOALLOCATE (fp) != WEOF)
+      return;
+  _IO_wsetb (fp, fp->_wide_data->_shortbuf, fp->_wide_data->_shortbuf + 1, 0);
+}
+
+
+_IO_FILE *
+_IO_wdefault_setbuf (fp, p, len)
+     _IO_FILE *fp;
+     wchar_t *p;
+     _IO_ssize_t len;
+{
+  if (_IO_SYNC (fp) == EOF)
+    return NULL;
+  if (p == NULL || len == 0)
+    {
+      fp->_flags |= _IO_UNBUFFERED;
+      _IO_wsetb (fp, fp->_wide_data->_shortbuf, fp->_wide_data->_shortbuf + 1,
+		 0);
+    }
+  else
+    {
+      fp->_flags &= ~_IO_UNBUFFERED;
+      _IO_wsetb (fp, p, p + len, 0);
+    }
+  fp->_wide_data->_IO_write_base = fp->_wide_data->_IO_write_ptr
+    = fp->_wide_data->_IO_write_end = 0;
+  fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_ptr
+    = fp->_wide_data->_IO_read_end = 0;
+  return fp;
+}
+
+
+int
+_IO_wdefault_doallocate (fp)
+     _IO_FILE *fp;
+{
+  wchar_t *buf;
+
+  ALLOC_WBUF (buf, _IO_BUFSIZ, EOF);
+  _IO_wsetb (fp, buf, buf + _IO_BUFSIZ, 1);
+  return 1;
+}
+
+
+int
+_IO_switch_to_wget_mode (fp)
+     _IO_FILE *fp;
+{
+  if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_write_base)
+    if (_IO_OVERFLOW (fp, EOF) == EOF)
+      return EOF;
+  if (_IO_in_backup (fp))
+    fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_backup_base;
+  else
+    {
+      fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_buf_base;
+      if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_read_end)
+	fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
+    }
+  fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_write_ptr;
+
+  fp->_wide_data->_IO_write_base = fp->_wide_data->_IO_write_ptr
+    = fp->_wide_data->_IO_write_end = fp->_wide_data->_IO_read_ptr;
+
+  fp->_flags &= ~_IO_CURRENTLY_PUTTING;
+  return 0;
+}
+
+void
+_IO_free_wbackup_area (fp)
+     _IO_FILE *fp;
+{
+  if (_IO_in_backup (fp))
+    _IO_switch_to_main_wget_area (fp);  /* Just in case. */
+  free (fp->_wide_data->_IO_save_base);
+  fp->_wide_data->_IO_save_base = NULL;
+  fp->_wide_data->_IO_save_end = NULL;
+  fp->_wide_data->_IO_backup_base = NULL;
+}
+
+#if 0
+int
+_IO_switch_to_wput_mode (fp)
+     _IO_FILE *fp;
+{
+  fp->_wide_data->_IO_write_base = fp->_wide_data->_IO_read_ptr;
+  fp->_wide_data->_IO_write_ptr = fp->_wide_data->_IO_read_ptr;
+  /* Following is wrong if line- or un-buffered? */
+  fp->_wide_data->_IO_write_end = (fp->_flags & _IO_IN_BACKUP
+				   ? fp->_wide_data->_IO_read_end
+				   : fp->_wide_data->_IO_buf_end);
+
+  fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
+  fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_end;
+
+  fp->_flags |= _IO_CURRENTLY_PUTTING;
+  return 0;
+}
+#endif
+
+
+static int
+#ifdef _LIBC
+internal_function
+#endif
+save_for_wbackup (fp, end_p)
+     _IO_FILE *fp;
+     wchar_t *end_p;
+{
+  /* Append [_IO_read_base..end_p] to backup area. */
+  _IO_ssize_t least_mark = _IO_least_wmarker (fp, end_p);
+  /* needed_size is how much space we need in the backup area. */
+  _IO_size_t needed_size = ((end_p - fp->_wide_data->_IO_read_base)
+			    - least_mark);
+  /* FIXME: Dubious arithmetic if pointers are NULL */
+  _IO_size_t current_Bsize = (fp->_wide_data->_IO_save_end
+			      - fp->_wide_data->_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)
+    {
+      wchar_t *new_buffer;
+      avail = 100;
+      new_buffer = (wchar_t *) malloc ((avail + needed_size)
+				       * sizeof (wchar_t));
+      if (new_buffer == NULL)
+	return EOF;		/* FIXME */
+      if (least_mark < 0)
+	{
+#ifdef _LIBC
+	  __wmempcpy (__wmempcpy (new_buffer + avail,
+				  fp->_wide_data->_IO_save_end + least_mark,
+				  -least_mark),
+		      fp->_wide_data->_IO_read_base,
+		      end_p - fp->_wide_data->_IO_read_base);
+#else
+	  memcpy (new_buffer + avail,
+		  fp->_wide_data->_IO_save_end + least_mark,
+		  -least_mark * sizeof (wchar_t));
+	  memcpy (new_buffer + avail - least_mark,
+		  fp->_wide_data->_IO_read_base,
+		  (end_p - fp->_wide_data->_IO_read_base) * sizeof (wchar_t));
+#endif
+	}
+      else
+	{
+#ifdef _LIBC
+	  __wmemcpy (new_buffer + avail,
+		     fp->_wide_data->_IO_read_base + least_mark,
+		     needed_size);
+#else
+	  memcpy (new_buffer + avail,
+		  fp->_wide_data->_IO_read_base + least_mark,
+		  needed_size * sizeof (wchar_t));
+#endif
+	}
+      if (fp->_wide_data->_IO_save_base)
+	free (fp->_wide_data->_IO_save_base);
+      fp->_wide_data->_IO_save_base = new_buffer;
+      fp->_wide_data->_IO_save_end = new_buffer + avail + needed_size;
+    }
+  else
+    {
+      avail = current_Bsize - needed_size;
+      if (least_mark < 0)
+	{
+#ifdef _LIBC
+	  __wmemmove (fp->_wide_data->_IO_save_base + avail,
+		      fp->_wide_data->_IO_save_end + least_mark,
+		      -least_mark);
+	  __wmemcpy (fp->_wide_data->_IO_save_base + avail - least_mark,
+		     fp->_wide_data->_IO_read_base,
+		     end_p - fp->_wide_data->_IO_read_base);
+#else
+	  memmove (fp->_wide_data->_IO_save_base + avail,
+		   fp->_wide_data->_IO_save_end + least_mark,
+		   -least_mark * sizeof (wchar_t));
+	  memcpy (fp->_wide_data->_IO_save_base + avail - least_mark,
+		  fp->_wide_data->_IO_read_base,
+		  (end_p - fp->_wide_data->_IO_read_base) * sizeof (wchar_t));
+#endif
+	}
+      else if (needed_size > 0)
+#ifdef _LIBC
+	__wmemcpy (fp->_wide_data->_IO_save_base + avail,
+		   fp->_wide_data->_IO_read_base + least_mark,
+		   needed_size);
+#else
+	memcpy (fp->_wide_data->_IO_save_base + avail,
+		fp->_wide_data->_IO_read_base + least_mark,
+		needed_size * sizeof (wchar_t));
+#endif
+    }
+  fp->_wide_data->_IO_backup_base = fp->_wide_data->_IO_save_base + avail;
+  /* Adjust all the streammarkers. */
+  delta = end_p - fp->_wide_data->_IO_read_base;
+  for (mark = fp->_markers; mark != NULL; mark = mark->_next)
+    mark->_pos -= delta;
+  return 0;
+}
+
+wint_t
+_IO_sputbackwc (fp, c)
+     _IO_FILE *fp;
+     wint_t c;
+{
+  wint_t result;
+
+  if (fp->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base
+      && (wchar_t)fp->_wide_data->_IO_read_ptr[-1] == (wchar_t) c)
+    {
+      fp->_wide_data->_IO_read_ptr--;
+      result = c;
+    }
+  else
+    result = _IO_PBACKFAIL (fp, c);
+
+  if (result != EOF)
+    fp->_flags &= ~_IO_EOF_SEEN;
+
+  return result;
+}
+
+wint_t
+_IO_sungetwc (fp)
+     _IO_FILE *fp;
+{
+  int result;
+
+  if (fp->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base)
+    {
+      fp->_wide_data->_IO_read_ptr--;
+      result = *fp->_wide_data->_IO_read_ptr;
+    }
+  else
+    result = _IO_PBACKFAIL (fp, EOF);
+
+  if (result != WEOF)
+    fp->_flags &= ~_IO_EOF_SEEN;
+
+  return result;
+}
+
+
+unsigned
+_IO_adjust_wcolumn (start, line, count)
+     unsigned start;
+     const wchar_t *line;
+     int count;
+{
+  const wchar_t *ptr = line + count;
+  while (ptr > line)
+    if (*--ptr == L'\n')
+      return line + count - ptr - 1;
+  return start + count;
+}
+
+void
+_IO_init_wmarker (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->_wide_data->_IO_read_ptr - fp->_wide_data->_IO_read_end;
+  else
+    marker->_pos = (fp->_wide_data->_IO_read_ptr
+		    - fp->_wide_data->_IO_read_base);
+
+  /* Should perhaps sort the chain? */
+  marker->_next = fp->_markers;
+  fp->_markers = marker;
+}
+
+#define BAD_DELTA EOF
+
+/* Return difference between MARK and current position of MARK's stream. */
+int
+_IO_wmarker_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->_wide_data->_IO_read_ptr
+	       - mark->_sbuf->_wide_data->_IO_read_end);
+  else
+    cur_pos = (mark->_sbuf->_wide_data->_IO_read_ptr
+	       - mark->_sbuf->_wide_data->_IO_read_base);
+  return mark->_pos - cur_pos;
+}
+
+int
+_IO_seekwmark (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_wget_area (fp);
+      fp->_wide_data->_IO_read_ptr = (fp->_wide_data->_IO_read_base
+				      + mark->_pos);
+    }
+  else
+    {
+      if (!_IO_in_backup (fp))
+	_IO_switch_to_wbackup_area (fp);
+      fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end + mark->_pos;
+    }
+  return 0;
+}
+
+void
+_IO_unsave_wmarkers (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_wbackup_area (fp);
+}