libio/wgenops.c

   1 /* Copyright (C) 1993-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Written by Ulrich Drepper <drepper@cygnus.com>.
   4    Based on the single byte version by Per Bothner <bothner@cygnus.com>.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.
  19
  20    As a special exception, if you link the code in this file with
  21    files compiled with a GNU compiler to produce an executable,
  22    that does not cause the resulting executable to be covered by
  23    the GNU Lesser General Public License.  This exception does not
  24    however invalidate any other reasons why the executable file
  25    might be covered by the GNU Lesser General Public License.
  26    This exception applies to code released by its copyright holders
  27    in files containing the exception.  */
  28
  29 /* Generic or default I/O operations. */
  30
  31 #include "libioP.h"
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <wchar.h>
  35
  36
  37 #ifndef _LIBC
  38 # define __wmemcpy(dst, src, n) wmemcpy (dst, src, n)
  39 #endif
  40
  41
  42 static int save_for_wbackup (_IO_FILE *fp, wchar_t *end_p) __THROW
  43 #ifdef _LIBC
  44      internal_function
  45 #endif
  46      ;
  47
  48 /* Return minimum _pos markers
  49    Assumes the current get area is the main get area. */
  50 _IO_ssize_t
  51 _IO_least_wmarker (_IO_FILE *fp, wchar_t *end_p)
  52 {
  53   _IO_ssize_t least_so_far = end_p - fp->_wide_data->_IO_read_base;
  54   struct _IO_marker *mark;
  55   for (mark = fp->_markers; mark != NULL; mark = mark->_next)
  56     if (mark->_pos < least_so_far)
  57       least_so_far = mark->_pos;
  58   return least_so_far;
  59 }
  60 libc_hidden_def (_IO_least_wmarker)
  61
  62 /* Switch current get area from backup buffer to (start of) main get area. */
  63 void
  64 _IO_switch_to_main_wget_area (_IO_FILE *fp)
  65 {
  66   wchar_t *tmp;
  67   fp->_flags &= ~_IO_IN_BACKUP;
  68   /* Swap _IO_read_end and _IO_save_end. */
  69   tmp = fp->_wide_data->_IO_read_end;
  70   fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_save_end;
  71   fp->_wide_data->_IO_save_end= tmp;
  72   /* Swap _IO_read_base and _IO_save_base. */
  73   tmp = fp->_wide_data->_IO_read_base;
  74   fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_save_base;
  75   fp->_wide_data->_IO_save_base = tmp;
  76   /* Set _IO_read_ptr. */
  77   fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_base;
  78 }
  79 libc_hidden_def (_IO_switch_to_main_wget_area)
  80
  81
  82 /* Switch current get area from main get area to (end of) backup area. */
  83 void
  84 _IO_switch_to_wbackup_area (_IO_FILE *fp)
  85 {
  86   wchar_t *tmp;
  87   fp->_flags |= _IO_IN_BACKUP;
  88   /* Swap _IO_read_end and _IO_save_end. */
  89   tmp = fp->_wide_data->_IO_read_end;
  90   fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_save_end;
  91   fp->_wide_data->_IO_save_end = tmp;
  92   /* Swap _IO_read_base and _IO_save_base. */
  93   tmp = fp->_wide_data->_IO_read_base;
  94   fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_save_base;
  95   fp->_wide_data->_IO_save_base = tmp;
  96   /* Set _IO_read_ptr.  */
  97   fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
  98 }
  99 libc_hidden_def (_IO_switch_to_wbackup_area)
 100
 101
 102 void
 103 _IO_wsetb (_IO_FILE *f, wchar_t *b, wchar_t *eb, int a)
 104 {
 105   if (f->_wide_data->_IO_buf_base && !(f->_flags2 & _IO_FLAGS2_USER_WBUF))
 106     free (f->_wide_data->_IO_buf_base);
 107   f->_wide_data->_IO_buf_base = b;
 108   f->_wide_data->_IO_buf_end = eb;
 109   if (a)
 110     f->_flags2 &= ~_IO_FLAGS2_USER_WBUF;
 111   else
 112     f->_flags2 |= _IO_FLAGS2_USER_WBUF;
 113 }
 114 libc_hidden_def (_IO_wsetb)
 115
 116
 117 wint_t
 118 _IO_wdefault_pbackfail (_IO_FILE *fp, wint_t c)
 119 {
 120   if (fp->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base
 121       && !_IO_in_backup (fp)
 122       && (wint_t) fp->_IO_read_ptr[-1] == c)
 123     --fp->_IO_read_ptr;
 124   else
 125     {
 126       /* Need to handle a filebuf in write mode (switch to read mode). FIXME!*/
 127       if (!_IO_in_backup (fp))
 128         {
 129           /* We need to keep the invariant that the main get area
 130              logically follows the backup area.  */
 131           if (fp->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base
 132               && _IO_have_wbackup (fp))
 133             {
 134               if (save_for_wbackup (fp, fp->_wide_data->_IO_read_ptr))
 135                 return WEOF;
 136             }
 137           else if (!_IO_have_wbackup (fp))
 138             {
 139               /* No backup buffer: allocate one. */
 140               /* Use nshort buffer, if unused? (probably not)  FIXME */
 141               int backup_size = 128;
 142               wchar_t *bbuf = (wchar_t *) malloc (backup_size
 143                                                   * sizeof (wchar_t));
 144               if (bbuf == NULL)
 145                 return WEOF;
 146               fp->_wide_data->_IO_save_base = bbuf;
 147               fp->_wide_data->_IO_save_end = (fp->_wide_data->_IO_save_base
 148                                               + backup_size);
 149               fp->_wide_data->_IO_backup_base = fp->_wide_data->_IO_save_end;
 150             }
 151           fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_ptr;
 152           _IO_switch_to_wbackup_area (fp);
 153         }
 154       else if (fp->_wide_data->_IO_read_ptr <= fp->_wide_data->_IO_read_base)
 155         {
 156           /* Increase size of existing backup buffer. */
 157           _IO_size_t new_size;
 158           _IO_size_t old_size = (fp->_wide_data->_IO_read_end
 159                                  - fp->_wide_data->_IO_read_base);
 160           wchar_t *new_buf;
 161           new_size = 2 * old_size;
 162           new_buf = (wchar_t *) malloc (new_size * sizeof (wchar_t));
 163           if (new_buf == NULL)
 164             return WEOF;
 165           __wmemcpy (new_buf + (new_size - old_size),
 166                      fp->_wide_data->_IO_read_base, old_size);
 167           free (fp->_wide_data->_IO_read_base);
 168           _IO_wsetg (fp, new_buf, new_buf + (new_size - old_size),
 169                      new_buf + new_size);
 170           fp->_wide_data->_IO_backup_base = fp->_wide_data->_IO_read_ptr;
 171         }
 172
 173       *--fp->_wide_data->_IO_read_ptr = c;
 174     }
 175   return c;
 176 }
 177 libc_hidden_def (_IO_wdefault_pbackfail)
 178
 179
 180 void
 181 _IO_wdefault_finish (_IO_FILE *fp, int dummy)
 182 {
 183   struct _IO_marker *mark;
 184   if (fp->_wide_data->_IO_buf_base && !(fp->_flags2 & _IO_FLAGS2_USER_WBUF))
 185     {
 186       free (fp->_wide_data->_IO_buf_base);
 187       fp->_wide_data->_IO_buf_base = fp->_wide_data->_IO_buf_end = NULL;
 188     }
 189
 190   for (mark = fp->_markers; mark != NULL; mark = mark->_next)
 191     mark->_sbuf = NULL;
 192
 193   if (fp->_IO_save_base)
 194     {
 195       free (fp->_wide_data->_IO_save_base);
 196       fp->_IO_save_base = NULL;
 197     }
 198
 199 #ifdef _IO_MTSAFE_IO
 200   if (fp->_lock != NULL)
 201     _IO_lock_fini (*fp->_lock);
 202 #endif
 203
 204   _IO_un_link ((struct _IO_FILE_plus *) fp);
 205 }
 206 libc_hidden_def (_IO_wdefault_finish)
 207
 208
 209 wint_t
 210 _IO_wdefault_uflow (_IO_FILE *fp)
 211 {
 212   wint_t wch;
 213   wch = _IO_UNDERFLOW (fp);
 214   if (wch == WEOF)
 215     return WEOF;
 216   return *fp->_wide_data->_IO_read_ptr++;
 217 }
 218 libc_hidden_def (_IO_wdefault_uflow)
 219
 220
 221 wint_t
 222 __woverflow (_IO_FILE *f, wint_t wch)
 223 {
 224   if (f->_mode == 0)
 225     _IO_fwide (f, 1);
 226   return _IO_OVERFLOW (f, wch);
 227 }
 228 libc_hidden_def (__woverflow)
 229
 230
 231 wint_t
 232 __wuflow (_IO_FILE *fp)
 233 {
 234   if (fp->_mode < 0 || (fp->_mode == 0 && _IO_fwide (fp, 1) != 1))
 235     return WEOF;
 236
 237   if (fp->_mode == 0)
 238     _IO_fwide (fp, 1);
 239   if (_IO_in_put_mode (fp))
 240     if (_IO_switch_to_wget_mode (fp) == EOF)
 241       return WEOF;
 242   if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
 243     return *fp->_wide_data->_IO_read_ptr++;
 244   if (_IO_in_backup (fp))
 245     {
 246       _IO_switch_to_main_wget_area (fp);
 247       if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
 248         return *fp->_wide_data->_IO_read_ptr++;
 249     }
 250   if (_IO_have_markers (fp))
 251     {
 252       if (save_for_wbackup (fp, fp->_wide_data->_IO_read_end))
 253         return WEOF;
 254     }
 255   else if (_IO_have_wbackup (fp))
 256     _IO_free_wbackup_area (fp);
 257   return _IO_UFLOW (fp);
 258 }
 259 libc_hidden_def (__wuflow)
 260
 261 wint_t
 262 __wunderflow (_IO_FILE *fp)
 263 {
 264   if (fp->_mode < 0 || (fp->_mode == 0 && _IO_fwide (fp, 1) != 1))
 265     return WEOF;
 266
 267   if (fp->_mode == 0)
 268     _IO_fwide (fp, 1);
 269   if (_IO_in_put_mode (fp))
 270     if (_IO_switch_to_wget_mode (fp) == EOF)
 271       return WEOF;
 272   if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
 273     return *fp->_wide_data->_IO_read_ptr;
 274   if (_IO_in_backup (fp))
 275     {
 276       _IO_switch_to_main_wget_area (fp);
 277       if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
 278         return *fp->_wide_data->_IO_read_ptr;
 279     }
 280   if (_IO_have_markers (fp))
 281     {
 282       if (save_for_wbackup (fp, fp->_wide_data->_IO_read_end))
 283         return WEOF;
 284     }
 285   else if (_IO_have_backup (fp))
 286     _IO_free_wbackup_area (fp);
 287   return _IO_UNDERFLOW (fp);
 288 }
 289 libc_hidden_def (__wunderflow)
 290
 291
 292 _IO_size_t
 293 _IO_wdefault_xsputn (_IO_FILE *f, const void *data, _IO_size_t n)
 294 {
 295   const wchar_t *s = (const wchar_t *) data;
 296   _IO_size_t more = n;
 297   if (more <= 0)
 298     return 0;
 299   for (;;)
 300     {
 301       /* Space available. */
 302       _IO_ssize_t count = (f->_wide_data->_IO_write_end
 303                            - f->_wide_data->_IO_write_ptr);
 304       if (count > 0)
 305         {
 306           if ((_IO_size_t) count > more)
 307             count = more;
 308           if (count > 20)
 309             {
 310 #ifdef _LIBC
 311               f->_wide_data->_IO_write_ptr =
 312                 __wmempcpy (f->_wide_data->_IO_write_ptr, s, count);
 313 #else
 314               memcpy (f->_wide_data->_IO_write_ptr, s, count);
 315               f->_wide_data->_IO_write_ptr += count;
 316 #endif
 317               s += count;
 318             }
 319           else if (count <= 0)
 320             count = 0;
 321           else
 322             {
 323               wchar_t *p = f->_wide_data->_IO_write_ptr;
 324               _IO_ssize_t i;
 325               for (i = count; --i >= 0; )
 326                 *p++ = *s++;
 327               f->_wide_data->_IO_write_ptr = p;
 328             }
 329           more -= count;
 330         }
 331       if (more == 0 || __woverflow (f, *s++) == WEOF)
 332         break;
 333       more--;
 334     }
 335   return n - more;
 336 }
 337 libc_hidden_def (_IO_wdefault_xsputn)
 338
 339
 340 _IO_size_t
 341 _IO_wdefault_xsgetn (_IO_FILE *fp, void *data, _IO_size_t n)
 342 {
 343   _IO_size_t more = n;
 344   wchar_t *s = (wchar_t*) data;
 345   for (;;)
 346     {
 347       /* Data available. */
 348       _IO_ssize_t count = (fp->_wide_data->_IO_read_end
 349                            - fp->_wide_data->_IO_read_ptr);
 350       if (count > 0)
 351         {
 352           if ((_IO_size_t) count > more)
 353             count = more;
 354           if (count > 20)
 355             {
 356 #ifdef _LIBC
 357               s = __wmempcpy (s, fp->_wide_data->_IO_read_ptr, count);
 358 #else
 359               memcpy (s, fp->_wide_data->_IO_read_ptr, count);
 360               s += count;
 361 #endif
 362               fp->_wide_data->_IO_read_ptr += count;
 363             }
 364           else if (count <= 0)
 365             count = 0;
 366           else
 367             {
 368               wchar_t *p = fp->_wide_data->_IO_read_ptr;
 369               int i = (int) count;
 370               while (--i >= 0)
 371                 *s++ = *p++;
 372               fp->_wide_data->_IO_read_ptr = p;
 373             }
 374             more -= count;
 375         }
 376       if (more == 0 || __wunderflow (fp) == WEOF)
 377         break;
 378     }
 379   return n - more;
 380 }
 381 libc_hidden_def (_IO_wdefault_xsgetn)
 382
 383
 384 void
 385 _IO_wdoallocbuf (_IO_FILE *fp)
 386 {
 387   if (fp->_wide_data->_IO_buf_base)
 388     return;
 389   if (!(fp->_flags & _IO_UNBUFFERED))
 390     if ((wint_t)_IO_WDOALLOCATE (fp) != WEOF)
 391       return;
 392   _IO_wsetb (fp, fp->_wide_data->_shortbuf,
 393                      fp->_wide_data->_shortbuf + 1, 0);
 394 }
 395 libc_hidden_def (_IO_wdoallocbuf)
 396
 397
 398 int
 399 _IO_wdefault_doallocate (_IO_FILE *fp)
 400 {
 401   wchar_t *buf;
 402
 403   buf = malloc (_IO_BUFSIZ);
 404   if (__glibc_unlikely (buf == NULL))
 405     return EOF;
 406   _IO_wsetb (fp, buf, buf + _IO_BUFSIZ, 1);
 407   return 1;
 408 }
 409 libc_hidden_def (_IO_wdefault_doallocate)
 410
 411
 412 int
 413 _IO_switch_to_wget_mode (_IO_FILE *fp)
 414 {
 415   if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_write_base)
 416     if ((wint_t)_IO_WOVERFLOW (fp, WEOF) == WEOF)
 417       return EOF;
 418   if (_IO_in_backup (fp))
 419     fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_backup_base;
 420   else
 421     {
 422       fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_buf_base;
 423       if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_read_end)
 424         fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
 425     }
 426   fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_write_ptr;
 427
 428   fp->_wide_data->_IO_write_base = fp->_wide_data->_IO_write_ptr
 429     = fp->_wide_data->_IO_write_end = fp->_wide_data->_IO_read_ptr;
 430
 431   fp->_flags &= ~_IO_CURRENTLY_PUTTING;
 432   return 0;
 433 }
 434 libc_hidden_def (_IO_switch_to_wget_mode)
 435
 436 void
 437 _IO_free_wbackup_area (_IO_FILE *fp)
 438 {
 439   if (_IO_in_backup (fp))
 440     _IO_switch_to_main_wget_area (fp);  /* Just in case. */
 441   free (fp->_wide_data->_IO_save_base);
 442   fp->_wide_data->_IO_save_base = NULL;
 443   fp->_wide_data->_IO_save_end = NULL;
 444   fp->_wide_data->_IO_backup_base = NULL;
 445 }
 446 libc_hidden_def (_IO_free_wbackup_area)
 447
 448 #if 0
 449 int
 450 _IO_switch_to_wput_mode (_IO_FILE *fp)
 451 {
 452   fp->_wide_data->_IO_write_base = fp->_wide_data->_IO_read_ptr;
 453   fp->_wide_data->_IO_write_ptr = fp->_wide_data->_IO_read_ptr;
 454   /* Following is wrong if line- or un-buffered? */
 455   fp->_wide_data->_IO_write_end = (fp->_flags & _IO_IN_BACKUP
 456                                    ? fp->_wide_data->_IO_read_end
 457                                    : fp->_wide_data->_IO_buf_end);
 458
 459   fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
 460   fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_end;
 461
 462   fp->_flags |= _IO_CURRENTLY_PUTTING;
 463   return 0;
 464 }
 465 #endif
 466
 467
 468 static int
 469 #ifdef _LIBC
 470 internal_function
 471 #endif
 472 save_for_wbackup (_IO_FILE *fp, wchar_t *end_p)
 473 {
 474   /* Append [_IO_read_base..end_p] to backup area. */
 475   _IO_ssize_t least_mark = _IO_least_wmarker (fp, end_p);
 476   /* needed_size is how much space we need in the backup area. */
 477   _IO_size_t needed_size = ((end_p - fp->_wide_data->_IO_read_base)
 478                             - least_mark);
 479   /* FIXME: Dubious arithmetic if pointers are NULL */
 480   _IO_size_t current_Bsize = (fp->_wide_data->_IO_save_end
 481                               - fp->_wide_data->_IO_save_base);
 482   _IO_size_t avail; /* Extra space available for future expansion. */
 483   _IO_ssize_t delta;
 484   struct _IO_marker *mark;
 485   if (needed_size > current_Bsize)
 486     {
 487       wchar_t *new_buffer;
 488       avail = 100;
 489       new_buffer = (wchar_t *) malloc ((avail + needed_size)
 490                                        * sizeof (wchar_t));
 491       if (new_buffer == NULL)
 492         return EOF;             /* FIXME */
 493       if (least_mark < 0)
 494         {
 495 #ifdef _LIBC
 496           __wmempcpy (__wmempcpy (new_buffer + avail,
 497                                   fp->_wide_data->_IO_save_end + least_mark,
 498                                   -least_mark),
 499                       fp->_wide_data->_IO_read_base,
 500                       end_p - fp->_wide_data->_IO_read_base);
 501 #else
 502           memcpy (new_buffer + avail,
 503                   fp->_wide_data->_IO_save_end + least_mark,
 504                   -least_mark * sizeof (wchar_t));
 505           memcpy (new_buffer + avail - least_mark,
 506                   fp->_wide_data->_IO_read_base,
 507                   (end_p - fp->_wide_data->_IO_read_base) * sizeof (wchar_t));
 508 #endif
 509         }
 510       else
 511         {
 512 #ifdef _LIBC
 513           __wmemcpy (new_buffer + avail,
 514                      fp->_wide_data->_IO_read_base + least_mark,
 515                      needed_size);
 516 #else
 517           memcpy (new_buffer + avail,
 518                   fp->_wide_data->_IO_read_base + least_mark,
 519                   needed_size * sizeof (wchar_t));
 520 #endif
 521         }
 522       free (fp->_wide_data->_IO_save_base);
 523       fp->_wide_data->_IO_save_base = new_buffer;
 524       fp->_wide_data->_IO_save_end = new_buffer + avail + needed_size;
 525     }
 526   else
 527     {
 528       avail = current_Bsize - needed_size;
 529       if (least_mark < 0)
 530         {
 531 #ifdef _LIBC
 532           __wmemmove (fp->_wide_data->_IO_save_base + avail,
 533                       fp->_wide_data->_IO_save_end + least_mark,
 534                       -least_mark);
 535           __wmemcpy (fp->_wide_data->_IO_save_base + avail - least_mark,
 536                      fp->_wide_data->_IO_read_base,
 537                      end_p - fp->_wide_data->_IO_read_base);
 538 #else
 539           memmove (fp->_wide_data->_IO_save_base + avail,
 540                    fp->_wide_data->_IO_save_end + least_mark,
 541                    -least_mark * sizeof (wchar_t));
 542           memcpy (fp->_wide_data->_IO_save_base + avail - least_mark,
 543                   fp->_wide_data->_IO_read_base,
 544                   (end_p - fp->_wide_data->_IO_read_base) * sizeof (wchar_t));
 545 #endif
 546         }
 547       else if (needed_size > 0)
 548 #ifdef _LIBC
 549         __wmemcpy (fp->_wide_data->_IO_save_base + avail,
 550                    fp->_wide_data->_IO_read_base + least_mark,
 551                    needed_size);
 552 #else
 553         memcpy (fp->_wide_data->_IO_save_base + avail,
 554                 fp->_wide_data->_IO_read_base + least_mark,
 555                 needed_size * sizeof (wchar_t));
 556 #endif
 557     }
 558   fp->_wide_data->_IO_backup_base = fp->_wide_data->_IO_save_base + avail;
 559   /* Adjust all the streammarkers. */
 560   delta = end_p - fp->_wide_data->_IO_read_base;
 561   for (mark = fp->_markers; mark != NULL; mark = mark->_next)
 562     mark->_pos -= delta;
 563   return 0;
 564 }
 565
 566 wint_t
 567 _IO_sputbackwc (_IO_FILE *fp, wint_t c)
 568 {
 569   wint_t result;
 570
 571   if (fp->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base
 572       && (wchar_t)fp->_wide_data->_IO_read_ptr[-1] == (wchar_t) c)
 573     {
 574       fp->_wide_data->_IO_read_ptr--;
 575       result = c;
 576     }
 577   else
 578     result = _IO_PBACKFAIL (fp, c);
 579
 580   if (result != WEOF)
 581     fp->_flags &= ~_IO_EOF_SEEN;
 582
 583   return result;
 584 }
 585 libc_hidden_def (_IO_sputbackwc)
 586
 587 wint_t
 588 _IO_sungetwc (_IO_FILE *fp)
 589 {
 590   wint_t result;
 591
 592   if (fp->_wide_data->_IO_read_ptr > fp->_wide_data->_IO_read_base)
 593     {
 594       fp->_wide_data->_IO_read_ptr--;
 595       result = *fp->_wide_data->_IO_read_ptr;
 596     }
 597   else
 598     result = _IO_PBACKFAIL (fp, EOF);
 599
 600   if (result != WEOF)
 601     fp->_flags &= ~_IO_EOF_SEEN;
 602
 603   return result;
 604 }
 605
 606
 607 unsigned
 608 _IO_adjust_wcolumn (unsigned start, const wchar_t *line, int count)
 609 {
 610   const wchar_t *ptr = line + count;
 611   while (ptr > line)
 612     if (*--ptr == L'\n')
 613       return line + count - ptr - 1;
 614   return start + count;
 615 }
 616
 617 void
 618 _IO_init_wmarker (struct _IO_marker *marker, _IO_FILE *fp)
 619 {
 620   marker->_sbuf = fp;
 621   if (_IO_in_put_mode (fp))
 622     _IO_switch_to_wget_mode (fp);
 623   if (_IO_in_backup (fp))
 624     marker->_pos = fp->_wide_data->_IO_read_ptr - fp->_wide_data->_IO_read_end;
 625   else
 626     marker->_pos = (fp->_wide_data->_IO_read_ptr
 627                     - fp->_wide_data->_IO_read_base);
 628
 629   /* Should perhaps sort the chain? */
 630   marker->_next = fp->_markers;
 631   fp->_markers = marker;
 632 }
 633
 634 #define BAD_DELTA EOF
 635
 636 /* Return difference between MARK and current position of MARK's stream. */
 637 int
 638 _IO_wmarker_delta (struct _IO_marker *mark)
 639 {
 640   int cur_pos;
 641   if (mark->_sbuf == NULL)
 642     return BAD_DELTA;
 643   if (_IO_in_backup (mark->_sbuf))
 644     cur_pos = (mark->_sbuf->_wide_data->_IO_read_ptr
 645                - mark->_sbuf->_wide_data->_IO_read_end);
 646   else
 647     cur_pos = (mark->_sbuf->_wide_data->_IO_read_ptr
 648                - mark->_sbuf->_wide_data->_IO_read_base);
 649   return mark->_pos - cur_pos;
 650 }
 651
 652 int
 653 _IO_seekwmark (_IO_FILE *fp, struct _IO_marker *mark, int delta)
 654 {
 655   if (mark->_sbuf != fp)
 656     return EOF;
 657  if (mark->_pos >= 0)
 658     {
 659       if (_IO_in_backup (fp))
 660         _IO_switch_to_main_wget_area (fp);
 661       fp->_wide_data->_IO_read_ptr = (fp->_wide_data->_IO_read_base
 662                                       + mark->_pos);
 663     }
 664   else
 665     {
 666       if (!_IO_in_backup (fp))
 667         _IO_switch_to_wbackup_area (fp);
 668       fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end + mark->_pos;
 669     }
 670   return 0;
 671 }
 672
 673 void
 674 _IO_unsave_wmarkers (_IO_FILE *fp)
 675 {
 676   struct _IO_marker *mark = fp->_markers;
 677   if (mark)
 678     {
 679 #ifdef TODO
 680       streampos offset = seekoff (0, ios::cur, ios::in);
 681       if (offset != EOF)
 682         {
 683           offset += eGptr () - Gbase ();
 684           for ( ; mark != NULL; mark = mark->_next)
 685             mark->set_streampos (mark->_pos + offset);
 686         }
 687     else
 688       {
 689         for ( ; mark != NULL; mark = mark->_next)
 690           mark->set_streampos (EOF);
 691       }
 692 #endif
 693       fp->_markers = 0;
 694     }
 695
 696   if (_IO_have_backup (fp))
 697     _IO_free_wbackup_area (fp);
 698 }