libio/genops.c

   1 /* Copyright (C) 1993-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.
  17
  18    As a special exception, if you link the code in this file with
  19    files compiled with a GNU compiler to produce an executable,
  20    that does not cause the resulting executable to be covered by
  21    the GNU Lesser General Public License.  This exception does not
  22    however invalidate any other reasons why the executable file
  23    might be covered by the GNU Lesser General Public License.
  24    This exception applies to code released by its copyright holders
  25    in files containing the exception.  */
  26
  27 /* Generic or default I/O operations. */
  28
  29 #include "libioP.h"
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdbool.h>
  33 #ifdef _LIBC
  34 #include <sched.h>
  35 #endif
  36
  37 #ifdef _IO_MTSAFE_IO
  38 static _IO_lock_t list_all_lock = _IO_lock_initializer;
  39 #endif
  40
  41 /* Used to signal modifications to the list of FILE decriptors.  */
  42 static int _IO_list_all_stamp;
  43
  44
  45 static _IO_FILE *run_fp;
  46
  47 #ifdef _IO_MTSAFE_IO
  48 static void
  49 flush_cleanup (void *not_used)
  50 {
  51   if (run_fp != NULL)
  52     _IO_funlockfile (run_fp);
  53   _IO_lock_unlock (list_all_lock);
  54 }
  55 #endif
  56
  57 void
  58 _IO_un_link (struct _IO_FILE_plus *fp)
  59 {
  60   if (fp->file._flags & _IO_LINKED)
  61     {
  62       struct _IO_FILE **f;
  63 #ifdef _IO_MTSAFE_IO
  64       _IO_cleanup_region_start_noarg (flush_cleanup);
  65       _IO_lock_lock (list_all_lock);
  66       run_fp = (_IO_FILE *) fp;
  67       _IO_flockfile ((_IO_FILE *) fp);
  68 #endif
  69       if (_IO_list_all == NULL)
  70         ;
  71       else if (fp == _IO_list_all)
  72         {
  73           _IO_list_all = (struct _IO_FILE_plus *) _IO_list_all->file._chain;
  74           ++_IO_list_all_stamp;
  75         }
  76       else
  77         for (f = &_IO_list_all->file._chain; *f; f = &(*f)->_chain)
  78           if (*f == (_IO_FILE *) fp)
  79             {
  80               *f = fp->file._chain;
  81               ++_IO_list_all_stamp;
  82               break;
  83             }
  84       fp->file._flags &= ~_IO_LINKED;
  85 #ifdef _IO_MTSAFE_IO
  86       _IO_funlockfile ((_IO_FILE *) fp);
  87       run_fp = NULL;
  88       _IO_lock_unlock (list_all_lock);
  89       _IO_cleanup_region_end (0);
  90 #endif
  91     }
  92 }
  93 libc_hidden_def (_IO_un_link)
  94
  95 void
  96 _IO_link_in (struct _IO_FILE_plus *fp)
  97 {
  98   if ((fp->file._flags & _IO_LINKED) == 0)
  99     {
 100       fp->file._flags |= _IO_LINKED;
 101 #ifdef _IO_MTSAFE_IO
 102       _IO_cleanup_region_start_noarg (flush_cleanup);
 103       _IO_lock_lock (list_all_lock);
 104       run_fp = (_IO_FILE *) fp;
 105       _IO_flockfile ((_IO_FILE *) fp);
 106 #endif
 107       fp->file._chain = (_IO_FILE *) _IO_list_all;
 108       _IO_list_all = fp;
 109       ++_IO_list_all_stamp;
 110 #ifdef _IO_MTSAFE_IO
 111       _IO_funlockfile ((_IO_FILE *) fp);
 112       run_fp = NULL;
 113       _IO_lock_unlock (list_all_lock);
 114       _IO_cleanup_region_end (0);
 115 #endif
 116     }
 117 }
 118 libc_hidden_def (_IO_link_in)
 119
 120 /* Return minimum _pos markers
 121    Assumes the current get area is the main get area. */
 122 _IO_ssize_t _IO_least_marker (_IO_FILE *fp, char *end_p);
 123
 124 _IO_ssize_t
 125 _IO_least_marker (_IO_FILE *fp, char *end_p)
 126 {
 127   _IO_ssize_t least_so_far = end_p - fp->_IO_read_base;
 128   struct _IO_marker *mark;
 129   for (mark = fp->_markers; mark != NULL; mark = mark->_next)
 130     if (mark->_pos < least_so_far)
 131       least_so_far = mark->_pos;
 132   return least_so_far;
 133 }
 134
 135 /* Switch current get area from backup buffer to (start of) main get area. */
 136
 137 void
 138 _IO_switch_to_main_get_area (_IO_FILE *fp)
 139 {
 140   char *tmp;
 141   fp->_flags &= ~_IO_IN_BACKUP;
 142   /* Swap _IO_read_end and _IO_save_end. */
 143   tmp = fp->_IO_read_end;
 144   fp->_IO_read_end = fp->_IO_save_end;
 145   fp->_IO_save_end= tmp;
 146   /* Swap _IO_read_base and _IO_save_base. */
 147   tmp = fp->_IO_read_base;
 148   fp->_IO_read_base = fp->_IO_save_base;
 149   fp->_IO_save_base = tmp;
 150   /* Set _IO_read_ptr. */
 151   fp->_IO_read_ptr = fp->_IO_read_base;
 152 }
 153
 154 /* Switch current get area from main get area to (end of) backup area. */
 155
 156 void
 157 _IO_switch_to_backup_area (_IO_FILE *fp)
 158 {
 159   char *tmp;
 160   fp->_flags |= _IO_IN_BACKUP;
 161   /* Swap _IO_read_end and _IO_save_end. */
 162   tmp = fp->_IO_read_end;
 163   fp->_IO_read_end = fp->_IO_save_end;
 164   fp->_IO_save_end = tmp;
 165   /* Swap _IO_read_base and _IO_save_base. */
 166   tmp = fp->_IO_read_base;
 167   fp->_IO_read_base = fp->_IO_save_base;
 168   fp->_IO_save_base = tmp;
 169   /* Set _IO_read_ptr.  */
 170   fp->_IO_read_ptr = fp->_IO_read_end;
 171 }
 172
 173 int
 174 _IO_switch_to_get_mode (_IO_FILE *fp)
 175 {
 176   if (fp->_IO_write_ptr > fp->_IO_write_base)
 177     if (_IO_OVERFLOW (fp, EOF) == EOF)
 178       return EOF;
 179   if (_IO_in_backup (fp))
 180     fp->_IO_read_base = fp->_IO_backup_base;
 181   else
 182     {
 183       fp->_IO_read_base = fp->_IO_buf_base;
 184       if (fp->_IO_write_ptr > fp->_IO_read_end)
 185         fp->_IO_read_end = fp->_IO_write_ptr;
 186     }
 187   fp->_IO_read_ptr = fp->_IO_write_ptr;
 188
 189   fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = fp->_IO_read_ptr;
 190
 191   fp->_flags &= ~_IO_CURRENTLY_PUTTING;
 192   return 0;
 193 }
 194 libc_hidden_def (_IO_switch_to_get_mode)
 195
 196 void
 197 _IO_free_backup_area (_IO_FILE *fp)
 198 {
 199   if (_IO_in_backup (fp))
 200     _IO_switch_to_main_get_area (fp);  /* Just in case. */
 201   free (fp->_IO_save_base);
 202   fp->_IO_save_base = NULL;
 203   fp->_IO_save_end = NULL;
 204   fp->_IO_backup_base = NULL;
 205 }
 206 libc_hidden_def (_IO_free_backup_area)
 207
 208 #if 0
 209 int
 210 _IO_switch_to_put_mode (_IO_FILE *fp)
 211 {
 212   fp->_IO_write_base = fp->_IO_read_ptr;
 213   fp->_IO_write_ptr = fp->_IO_read_ptr;
 214   /* Following is wrong if line- or un-buffered? */
 215   fp->_IO_write_end = (fp->_flags & _IO_IN_BACKUP
 216                        ? fp->_IO_read_end : fp->_IO_buf_end);
 217
 218   fp->_IO_read_ptr = fp->_IO_read_end;
 219   fp->_IO_read_base = fp->_IO_read_end;
 220
 221   fp->_flags |= _IO_CURRENTLY_PUTTING;
 222   return 0;
 223 }
 224 #endif
 225
 226 int
 227 __overflow (_IO_FILE *f, int ch)
 228 {
 229   /* This is a single-byte stream.  */
 230   if (f->_mode == 0)
 231     _IO_fwide (f, -1);
 232   return _IO_OVERFLOW (f, ch);
 233 }
 234 libc_hidden_def (__overflow)
 235
 236 static int save_for_backup (_IO_FILE *fp, char *end_p)
 237 #ifdef _LIBC
 238      internal_function
 239 #endif
 240      ;
 241
 242 static int
 243 #ifdef _LIBC
 244 internal_function
 245 #endif
 246 save_for_backup (_IO_FILE *fp, char *end_p)
 247 {
 248   /* Append [_IO_read_base..end_p] to backup area. */
 249   _IO_ssize_t least_mark = _IO_least_marker (fp, end_p);
 250   /* needed_size is how much space we need in the backup area. */
 251   _IO_size_t needed_size = (end_p - fp->_IO_read_base) - least_mark;
 252   /* FIXME: Dubious arithmetic if pointers are NULL */
 253   _IO_size_t current_Bsize = fp->_IO_save_end - fp->_IO_save_base;
 254   _IO_size_t avail; /* Extra space available for future expansion. */
 255   _IO_ssize_t delta;
 256   struct _IO_marker *mark;
 257   if (needed_size > current_Bsize)
 258     {
 259       char *new_buffer;
 260       avail = 100;
 261       new_buffer = (char *) malloc (avail + needed_size);
 262       if (new_buffer == NULL)
 263         return EOF;             /* FIXME */
 264       if (least_mark < 0)
 265         {
 266 #ifdef _LIBC
 267           __mempcpy (__mempcpy (new_buffer + avail,
 268                                 fp->_IO_save_end + least_mark,
 269                                 -least_mark),
 270                      fp->_IO_read_base,
 271                      end_p - fp->_IO_read_base);
 272 #else
 273           memcpy (new_buffer + avail,
 274                   fp->_IO_save_end + least_mark,
 275                   -least_mark);
 276           memcpy (new_buffer + avail - least_mark,
 277                   fp->_IO_read_base,
 278                   end_p - fp->_IO_read_base);
 279 #endif
 280         }
 281       else
 282         memcpy (new_buffer + avail,
 283                 fp->_IO_read_base + least_mark,
 284                 needed_size);
 285       free (fp->_IO_save_base);
 286       fp->_IO_save_base = new_buffer;
 287       fp->_IO_save_end = new_buffer + avail + needed_size;
 288     }
 289   else
 290     {
 291       avail = current_Bsize - needed_size;
 292       if (least_mark < 0)
 293         {
 294           memmove (fp->_IO_save_base + avail,
 295                    fp->_IO_save_end + least_mark,
 296                    -least_mark);
 297           memcpy (fp->_IO_save_base + avail - least_mark,
 298                   fp->_IO_read_base,
 299                   end_p - fp->_IO_read_base);
 300         }
 301       else if (needed_size > 0)
 302         memcpy (fp->_IO_save_base + avail,
 303                 fp->_IO_read_base + least_mark,
 304                 needed_size);
 305     }
 306   fp->_IO_backup_base = fp->_IO_save_base + avail;
 307   /* Adjust all the streammarkers. */
 308   delta = end_p - fp->_IO_read_base;
 309   for (mark = fp->_markers; mark != NULL; mark = mark->_next)
 310     mark->_pos -= delta;
 311   return 0;
 312 }
 313
 314 int
 315 __underflow (_IO_FILE *fp)
 316 {
 317 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 318   if (_IO_vtable_offset (fp) == 0 && _IO_fwide (fp, -1) != -1)
 319     return EOF;
 320 #endif
 321
 322   if (fp->_mode == 0)
 323     _IO_fwide (fp, -1);
 324   if (_IO_in_put_mode (fp))
 325     if (_IO_switch_to_get_mode (fp) == EOF)
 326       return EOF;
 327   if (fp->_IO_read_ptr < fp->_IO_read_end)
 328     return *(unsigned char *) fp->_IO_read_ptr;
 329   if (_IO_in_backup (fp))
 330     {
 331       _IO_switch_to_main_get_area (fp);
 332       if (fp->_IO_read_ptr < fp->_IO_read_end)
 333         return *(unsigned char *) fp->_IO_read_ptr;
 334     }
 335   if (_IO_have_markers (fp))
 336     {
 337       if (save_for_backup (fp, fp->_IO_read_end))
 338         return EOF;
 339     }
 340   else if (_IO_have_backup (fp))
 341     _IO_free_backup_area (fp);
 342   return _IO_UNDERFLOW (fp);
 343 }
 344 libc_hidden_def (__underflow)
 345
 346 int
 347 __uflow (_IO_FILE *fp)
 348 {
 349 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 350   if (_IO_vtable_offset (fp) == 0 && _IO_fwide (fp, -1) != -1)
 351     return EOF;
 352 #endif
 353
 354   if (fp->_mode == 0)
 355     _IO_fwide (fp, -1);
 356   if (_IO_in_put_mode (fp))
 357     if (_IO_switch_to_get_mode (fp) == EOF)
 358       return EOF;
 359   if (fp->_IO_read_ptr < fp->_IO_read_end)
 360     return *(unsigned char *) fp->_IO_read_ptr++;
 361   if (_IO_in_backup (fp))
 362     {
 363       _IO_switch_to_main_get_area (fp);
 364       if (fp->_IO_read_ptr < fp->_IO_read_end)
 365         return *(unsigned char *) fp->_IO_read_ptr++;
 366     }
 367   if (_IO_have_markers (fp))
 368     {
 369       if (save_for_backup (fp, fp->_IO_read_end))
 370         return EOF;
 371     }
 372   else if (_IO_have_backup (fp))
 373     _IO_free_backup_area (fp);
 374   return _IO_UFLOW (fp);
 375 }
 376 libc_hidden_def (__uflow)
 377
 378 void
 379 _IO_setb (_IO_FILE *f, char *b, char *eb, int a)
 380 {
 381   if (f->_IO_buf_base && !(f->_flags & _IO_USER_BUF))
 382     free (f->_IO_buf_base);
 383   f->_IO_buf_base = b;
 384   f->_IO_buf_end = eb;
 385   if (a)
 386     f->_flags &= ~_IO_USER_BUF;
 387   else
 388     f->_flags |= _IO_USER_BUF;
 389 }
 390 libc_hidden_def (_IO_setb)
 391
 392 void
 393 _IO_doallocbuf (_IO_FILE *fp)
 394 {
 395   if (fp->_IO_buf_base)
 396     return;
 397   if (!(fp->_flags & _IO_UNBUFFERED) || fp->_mode > 0)
 398     if (_IO_DOALLOCATE (fp) != EOF)
 399       return;
 400   _IO_setb (fp, fp->_shortbuf, fp->_shortbuf+1, 0);
 401 }
 402 libc_hidden_def (_IO_doallocbuf)
 403
 404 int
 405 _IO_default_underflow (_IO_FILE *fp)
 406 {
 407   return EOF;
 408 }
 409
 410 int
 411 _IO_default_uflow (_IO_FILE *fp)
 412 {
 413   int ch = _IO_UNDERFLOW (fp);
 414   if (ch == EOF)
 415     return EOF;
 416   return *(unsigned char *) fp->_IO_read_ptr++;
 417 }
 418 libc_hidden_def (_IO_default_uflow)
 419
 420 _IO_size_t
 421 _IO_default_xsputn (_IO_FILE *f, const void *data, _IO_size_t n)
 422 {
 423   const char *s = (char *) data;
 424   _IO_size_t more = n;
 425   if (more <= 0)
 426     return 0;
 427   for (;;)
 428     {
 429       /* Space available. */
 430       if (f->_IO_write_ptr < f->_IO_write_end)
 431         {
 432           _IO_size_t count = f->_IO_write_end - f->_IO_write_ptr;
 433           if (count > more)
 434             count = more;
 435           if (count > 20)
 436             {
 437 #ifdef _LIBC
 438               f->_IO_write_ptr = __mempcpy (f->_IO_write_ptr, s, count);
 439 #else
 440               memcpy (f->_IO_write_ptr, s, count);
 441               f->_IO_write_ptr += count;
 442 #endif
 443               s += count;
 444             }
 445           else if (count)
 446             {
 447               char *p = f->_IO_write_ptr;
 448               _IO_ssize_t i;
 449               for (i = count; --i >= 0; )
 450                 *p++ = *s++;
 451               f->_IO_write_ptr = p;
 452             }
 453           more -= count;
 454         }
 455       if (more == 0 || _IO_OVERFLOW (f, (unsigned char) *s++) == EOF)
 456         break;
 457       more--;
 458     }
 459   return n - more;
 460 }
 461 libc_hidden_def (_IO_default_xsputn)
 462
 463 _IO_size_t
 464 _IO_sgetn (_IO_FILE *fp, void *data, _IO_size_t n)
 465 {
 466   /* FIXME handle putback buffer here! */
 467   return _IO_XSGETN (fp, data, n);
 468 }
 469 libc_hidden_def (_IO_sgetn)
 470
 471 _IO_size_t
 472 _IO_default_xsgetn (_IO_FILE *fp, void *data, _IO_size_t n)
 473 {
 474   _IO_size_t more = n;
 475   char *s = (char*) data;
 476   for (;;)
 477     {
 478       /* Data available. */
 479       if (fp->_IO_read_ptr < fp->_IO_read_end)
 480         {
 481           _IO_size_t count = fp->_IO_read_end - fp->_IO_read_ptr;
 482           if (count > more)
 483             count = more;
 484           if (count > 20)
 485             {
 486 #ifdef _LIBC
 487               s = __mempcpy (s, fp->_IO_read_ptr, count);
 488 #else
 489               memcpy (s, fp->_IO_read_ptr, count);
 490               s += count;
 491 #endif
 492               fp->_IO_read_ptr += count;
 493             }
 494           else if (count)
 495             {
 496               char *p = fp->_IO_read_ptr;
 497               int i = (int) count;
 498               while (--i >= 0)
 499                 *s++ = *p++;
 500               fp->_IO_read_ptr = p;
 501             }
 502             more -= count;
 503         }
 504       if (more == 0 || __underflow (fp) == EOF)
 505         break;
 506     }
 507   return n - more;
 508 }
 509 libc_hidden_def (_IO_default_xsgetn)
 510
 511 #if 0
 512 /* Seems not to be needed. --drepper */
 513 int
 514 _IO_sync (_IO_FILE *fp)
 515 {
 516   return 0;
 517 }
 518 #endif
 519
 520 _IO_FILE *
 521 _IO_default_setbuf (_IO_FILE *fp, char *p, _IO_ssize_t len)
 522 {
 523     if (_IO_SYNC (fp) == EOF)
 524         return NULL;
 525     if (p == NULL || len == 0)
 526       {
 527         fp->_flags |= _IO_UNBUFFERED;
 528         _IO_setb (fp, fp->_shortbuf, fp->_shortbuf+1, 0);
 529       }
 530     else
 531       {
 532         fp->_flags &= ~_IO_UNBUFFERED;
 533         _IO_setb (fp, p, p+len, 0);
 534       }
 535     fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = 0;
 536     fp->_IO_read_base = fp->_IO_read_ptr = fp->_IO_read_end = 0;
 537     return fp;
 538 }
 539
 540 _IO_off64_t
 541 _IO_default_seekpos (_IO_FILE *fp, _IO_off64_t pos, int mode)
 542 {
 543   return _IO_SEEKOFF (fp, pos, 0, mode);
 544 }
 545
 546 int
 547 _IO_default_doallocate (_IO_FILE *fp)
 548 {
 549   char *buf;
 550
 551   buf = malloc(_IO_BUFSIZ);
 552   if (__glibc_unlikely (buf == NULL))
 553     return EOF;
 554
 555   _IO_setb (fp, buf, buf+_IO_BUFSIZ, 1);
 556   return 1;
 557 }
 558 libc_hidden_def (_IO_default_doallocate)
 559
 560 void
 561 _IO_init (_IO_FILE *fp, int flags)
 562 {
 563   _IO_no_init (fp, flags, -1, NULL, NULL);
 564 }
 565 libc_hidden_def (_IO_init)
 566
 567 void
 568 _IO_old_init (_IO_FILE *fp, int flags)
 569 {
 570   fp->_flags = _IO_MAGIC|flags;
 571   fp->_flags2 = 0;
 572   fp->_IO_buf_base = NULL;
 573   fp->_IO_buf_end = NULL;
 574   fp->_IO_read_base = NULL;
 575   fp->_IO_read_ptr = NULL;
 576   fp->_IO_read_end = NULL;
 577   fp->_IO_write_base = NULL;
 578   fp->_IO_write_ptr = NULL;
 579   fp->_IO_write_end = NULL;
 580   fp->_chain = NULL; /* Not necessary. */
 581
 582   fp->_IO_save_base = NULL;
 583   fp->_IO_backup_base = NULL;
 584   fp->_IO_save_end = NULL;
 585   fp->_markers = NULL;
 586   fp->_cur_column = 0;
 587 #if _IO_JUMPS_OFFSET
 588   fp->_vtable_offset = 0;
 589 #endif
 590 #ifdef _IO_MTSAFE_IO
 591   if (fp->_lock != NULL)
 592     _IO_lock_init (*fp->_lock);
 593 #endif
 594 }
 595
 596 void
 597 _IO_no_init (_IO_FILE *fp, int flags, int orientation,
 598              struct _IO_wide_data *wd, const struct _IO_jump_t *jmp)
 599 {
 600   _IO_old_init (fp, flags);
 601   fp->_mode = orientation;
 602 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 603   if (orientation >= 0)
 604     {
 605       fp->_wide_data = wd;
 606       fp->_wide_data->_IO_buf_base = NULL;
 607       fp->_wide_data->_IO_buf_end = NULL;
 608       fp->_wide_data->_IO_read_base = NULL;
 609       fp->_wide_data->_IO_read_ptr = NULL;
 610       fp->_wide_data->_IO_read_end = NULL;
 611       fp->_wide_data->_IO_write_base = NULL;
 612       fp->_wide_data->_IO_write_ptr = NULL;
 613       fp->_wide_data->_IO_write_end = NULL;
 614       fp->_wide_data->_IO_save_base = NULL;
 615       fp->_wide_data->_IO_backup_base = NULL;
 616       fp->_wide_data->_IO_save_end = NULL;
 617
 618       fp->_wide_data->_wide_vtable = jmp;
 619     }
 620   else
 621     /* Cause predictable crash when a wide function is called on a byte
 622        stream.  */
 623     fp->_wide_data = (struct _IO_wide_data *) -1L;
 624 #endif
 625   fp->_freeres_list = NULL;
 626 }
 627
 628 int
 629 _IO_default_sync (_IO_FILE *fp)
 630 {
 631   return 0;
 632 }
 633
 634 /* The way the C++ classes are mapped into the C functions in the
 635    current implementation, this function can get called twice! */
 636
 637 void
 638 _IO_default_finish (_IO_FILE *fp, int dummy)
 639 {
 640   struct _IO_marker *mark;
 641   if (fp->_IO_buf_base && !(fp->_flags & _IO_USER_BUF))
 642     {
 643       free (fp->_IO_buf_base);
 644       fp->_IO_buf_base = fp->_IO_buf_end = NULL;
 645     }
 646
 647   for (mark = fp->_markers; mark != NULL; mark = mark->_next)
 648     mark->_sbuf = NULL;
 649
 650   if (fp->_IO_save_base)
 651     {
 652       free (fp->_IO_save_base);
 653       fp->_IO_save_base = NULL;
 654     }
 655
 656   _IO_un_link ((struct _IO_FILE_plus *) fp);
 657
 658 #ifdef _IO_MTSAFE_IO
 659   if (fp->_lock != NULL)
 660     _IO_lock_fini (*fp->_lock);
 661 #endif
 662 }
 663 libc_hidden_def (_IO_default_finish)
 664
 665 _IO_off64_t
 666 _IO_default_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
 667 {
 668   return _IO_pos_BAD;
 669 }
 670
 671 int
 672 _IO_sputbackc (_IO_FILE *fp, int c)
 673 {
 674   int result;
 675
 676   if (fp->_IO_read_ptr > fp->_IO_read_base
 677       && (unsigned char)fp->_IO_read_ptr[-1] == (unsigned char)c)
 678     {
 679       fp->_IO_read_ptr--;
 680       result = (unsigned char) c;
 681     }
 682   else
 683     result = _IO_PBACKFAIL (fp, c);
 684
 685   if (result != EOF)
 686     fp->_flags &= ~_IO_EOF_SEEN;
 687
 688   return result;
 689 }
 690 libc_hidden_def (_IO_sputbackc)
 691
 692 int
 693 _IO_sungetc (_IO_FILE *fp)
 694 {
 695   int result;
 696
 697   if (fp->_IO_read_ptr > fp->_IO_read_base)
 698     {
 699       fp->_IO_read_ptr--;
 700       result = (unsigned char) *fp->_IO_read_ptr;
 701     }
 702   else
 703     result = _IO_PBACKFAIL (fp, EOF);
 704
 705   if (result != EOF)
 706     fp->_flags &= ~_IO_EOF_SEEN;
 707
 708   return result;
 709 }
 710
 711 #if 0 /* Work in progress */
 712 /* Seems not to be needed.  */
 713 #if 0
 714 void
 715 _IO_set_column (_IO_FILE *fp, int c)
 716 {
 717   if (c == -1)
 718     fp->_column = -1;
 719   else
 720     fp->_column = c - (fp->_IO_write_ptr - fp->_IO_write_base);
 721 }
 722 #else
 723 int
 724 _IO_set_column (_IO_FILE *fp, int i)
 725 {
 726   fp->_cur_column = i + 1;
 727   return 0;
 728 }
 729 #endif
 730 #endif
 731
 732
 733 unsigned
 734 _IO_adjust_column (unsigned start, const char *line, int count)
 735 {
 736   const char *ptr = line + count;
 737   while (ptr > line)
 738     if (*--ptr == '\n')
 739       return line + count - ptr - 1;
 740   return start + count;
 741 }
 742 libc_hidden_def (_IO_adjust_column)
 743
 744 #if 0
 745 /* Seems not to be needed. --drepper */
 746 int
 747 _IO_get_column (_IO_FILE *fp)
 748 {
 749   if (fp->_cur_column)
 750     return _IO_adjust_column (fp->_cur_column - 1,
 751                               fp->_IO_write_base,
 752                               fp->_IO_write_ptr - fp->_IO_write_base);
 753   return -1;
 754 }
 755 #endif
 756
 757
 758 int
 759 _IO_flush_all_lockp (int do_lock)
 760 {
 761   int result = 0;
 762   struct _IO_FILE *fp;
 763   int last_stamp;
 764
 765 #ifdef _IO_MTSAFE_IO
 766   __libc_cleanup_region_start (do_lock, flush_cleanup, NULL);
 767   if (do_lock)
 768     _IO_lock_lock (list_all_lock);
 769 #endif
 770
 771   last_stamp = _IO_list_all_stamp;
 772   fp = (_IO_FILE *) _IO_list_all;
 773   while (fp != NULL)
 774     {
 775       run_fp = fp;
 776       if (do_lock)
 777         _IO_flockfile (fp);
 778
 779       if (((fp->_mode <= 0 && fp->_IO_write_ptr > fp->_IO_write_base)
 780 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 781            || (_IO_vtable_offset (fp) == 0
 782                && fp->_mode > 0 && (fp->_wide_data->_IO_write_ptr
 783                                     > fp->_wide_data->_IO_write_base))
 784 #endif
 785            )
 786           && _IO_OVERFLOW (fp, EOF) == EOF)
 787         result = EOF;
 788
 789       if (do_lock)
 790         _IO_funlockfile (fp);
 791       run_fp = NULL;
 792
 793       if (last_stamp != _IO_list_all_stamp)
 794         {
 795           /* Something was added to the list.  Start all over again.  */
 796           fp = (_IO_FILE *) _IO_list_all;
 797           last_stamp = _IO_list_all_stamp;
 798         }
 799       else
 800         fp = fp->_chain;
 801     }
 802
 803 #ifdef _IO_MTSAFE_IO
 804   if (do_lock)
 805     _IO_lock_unlock (list_all_lock);
 806   __libc_cleanup_region_end (0);
 807 #endif
 808
 809   return result;
 810 }
 811
 812
 813 int
 814 _IO_flush_all (void)
 815 {
 816   /* We want locking.  */
 817   return _IO_flush_all_lockp (1);
 818 }
 819 libc_hidden_def (_IO_flush_all)
 820
 821 void
 822 _IO_flush_all_linebuffered (void)
 823 {
 824   struct _IO_FILE *fp;
 825   int last_stamp;
 826
 827 #ifdef _IO_MTSAFE_IO
 828   _IO_cleanup_region_start_noarg (flush_cleanup);
 829   _IO_lock_lock (list_all_lock);
 830 #endif
 831
 832   last_stamp = _IO_list_all_stamp;
 833   fp = (_IO_FILE *) _IO_list_all;
 834   while (fp != NULL)
 835     {
 836       run_fp = fp;
 837       _IO_flockfile (fp);
 838
 839       if ((fp->_flags & _IO_NO_WRITES) == 0 && fp->_flags & _IO_LINE_BUF)
 840         _IO_OVERFLOW (fp, EOF);
 841
 842       _IO_funlockfile (fp);
 843       run_fp = NULL;
 844
 845       if (last_stamp != _IO_list_all_stamp)
 846         {
 847           /* Something was added to the list.  Start all over again.  */
 848           fp = (_IO_FILE *) _IO_list_all;
 849           last_stamp = _IO_list_all_stamp;
 850         }
 851       else
 852         fp = fp->_chain;
 853     }
 854
 855 #ifdef _IO_MTSAFE_IO
 856   _IO_lock_unlock (list_all_lock);
 857   _IO_cleanup_region_end (0);
 858 #endif
 859 }
 860 libc_hidden_def (_IO_flush_all_linebuffered)
 861 #ifdef _LIBC
 862 weak_alias (_IO_flush_all_linebuffered, _flushlbf)
 863 #endif
 864
 865
 866 /* The following is a bit tricky.  In general, we want to unbuffer the
 867    streams so that all output which follows is seen.  If we are not
 868    looking for memory leaks it does not make much sense to free the
 869    actual buffer because this will happen anyway once the program
 870    terminated.  If we do want to look for memory leaks we have to free
 871    the buffers.  Whether something is freed is determined by the
 872    function sin the libc_freeres section.  Those are called as part of
 873    the atexit routine, just like _IO_cleanup.  The problem is we do
 874    not know whether the freeres code is called first or _IO_cleanup.
 875    if the former is the case, we set the DEALLOC_BUFFER variable to
 876    true and _IO_unbuffer_all will take care of the rest.  If
 877    _IO_unbuffer_all is called first we add the streams to a list
 878    which the freeres function later can walk through.  */
 879 static void _IO_unbuffer_all (void);
 880
 881 static bool dealloc_buffers;
 882 static _IO_FILE *freeres_list;
 883
 884 static void
 885 _IO_unbuffer_all (void)
 886 {
 887   struct _IO_FILE *fp;
 888   for (fp = (_IO_FILE *) _IO_list_all; fp; fp = fp->_chain)
 889     {
 890       if (! (fp->_flags & _IO_UNBUFFERED)
 891           /* Iff stream is un-orientated, it wasn't used. */
 892           && fp->_mode != 0)
 893         {
 894 #ifdef _IO_MTSAFE_IO
 895           int cnt;
 896 #define MAXTRIES 2
 897           for (cnt = 0; cnt < MAXTRIES; ++cnt)
 898             if (fp->_lock == NULL || _IO_lock_trylock (*fp->_lock) == 0)
 899               break;
 900             else
 901               /* Give the other thread time to finish up its use of the
 902                  stream.  */
 903               __sched_yield ();
 904 #endif
 905
 906           if (! dealloc_buffers && !(fp->_flags & _IO_USER_BUF))
 907             {
 908               fp->_flags |= _IO_USER_BUF;
 909
 910               fp->_freeres_list = freeres_list;
 911               freeres_list = fp;
 912               fp->_freeres_buf = fp->_IO_buf_base;
 913             }
 914
 915           _IO_SETBUF (fp, NULL, 0);
 916
 917           if (fp->_mode > 0)
 918             _IO_wsetb (fp, NULL, NULL, 0);
 919
 920 #ifdef _IO_MTSAFE_IO
 921           if (cnt < MAXTRIES && fp->_lock != NULL)
 922             _IO_lock_unlock (*fp->_lock);
 923 #endif
 924         }
 925
 926       /* Make sure that never again the wide char functions can be
 927          used.  */
 928       fp->_mode = -1;
 929     }
 930 }
 931
 932
 933 libc_freeres_fn (buffer_free)
 934 {
 935   dealloc_buffers = true;
 936
 937   while (freeres_list != NULL)
 938     {
 939       free (freeres_list->_freeres_buf);
 940
 941       freeres_list = freeres_list->_freeres_list;
 942     }
 943 }
 944
 945
 946 int
 947 _IO_cleanup (void)
 948 {
 949   /* We do *not* want locking.  Some threads might use streams but
 950      that is their problem, we flush them underneath them.  */
 951   int result = _IO_flush_all_lockp (0);
 952
 953   /* We currently don't have a reliable mechanism for making sure that
 954      C++ static destructors are executed in the correct order.
 955      So it is possible that other static destructors might want to
 956      write to cout - and they're supposed to be able to do so.
 957
 958      The following will make the standard streambufs be unbuffered,
 959      which forces any output from late destructors to be written out. */
 960   _IO_unbuffer_all ();
 961
 962   return result;
 963 }
 964
 965
 966 void
 967 _IO_init_marker (struct _IO_marker *marker, _IO_FILE *fp)
 968 {
 969   marker->_sbuf = fp;
 970   if (_IO_in_put_mode (fp))
 971     _IO_switch_to_get_mode (fp);
 972   if (_IO_in_backup (fp))
 973     marker->_pos = fp->_IO_read_ptr - fp->_IO_read_end;
 974   else
 975     marker->_pos = fp->_IO_read_ptr - fp->_IO_read_base;
 976
 977   /* Should perhaps sort the chain? */
 978   marker->_next = fp->_markers;
 979   fp->_markers = marker;
 980 }
 981
 982 void
 983 _IO_remove_marker (struct _IO_marker *marker)
 984 {
 985   /* Unlink from sb's chain. */
 986   struct _IO_marker **ptr = &marker->_sbuf->_markers;
 987   for (; ; ptr = &(*ptr)->_next)
 988     {
 989       if (*ptr == NULL)
 990         break;
 991       else if (*ptr == marker)
 992         {
 993           *ptr = marker->_next;
 994           return;
 995         }
 996     }
 997 #if 0
 998     if _sbuf has a backup area that is no longer needed, should we delete
 999     it now, or wait until the next underflow?
1000 #endif
1001 }
1002
1003 #define BAD_DELTA EOF
1004
1005 int
1006 _IO_marker_difference (struct _IO_marker *mark1, struct _IO_marker *mark2)
1007 {
1008   return mark1->_pos - mark2->_pos;
1009 }
1010
1011 /* Return difference between MARK and current position of MARK's stream. */
1012 int
1013 _IO_marker_delta (struct _IO_marker *mark)
1014 {
1015   int cur_pos;
1016   if (mark->_sbuf == NULL)
1017     return BAD_DELTA;
1018   if (_IO_in_backup (mark->_sbuf))
1019     cur_pos = mark->_sbuf->_IO_read_ptr - mark->_sbuf->_IO_read_end;
1020   else
1021     cur_pos = mark->_sbuf->_IO_read_ptr - mark->_sbuf->_IO_read_base;
1022   return mark->_pos - cur_pos;
1023 }
1024
1025 int
1026 _IO_seekmark (_IO_FILE *fp, struct _IO_marker *mark, int delta)
1027 {
1028   if (mark->_sbuf != fp)
1029     return EOF;
1030  if (mark->_pos >= 0)
1031     {
1032       if (_IO_in_backup (fp))
1033         _IO_switch_to_main_get_area (fp);
1034       fp->_IO_read_ptr = fp->_IO_read_base + mark->_pos;
1035     }
1036   else
1037     {
1038       if (!_IO_in_backup (fp))
1039         _IO_switch_to_backup_area (fp);
1040       fp->_IO_read_ptr = fp->_IO_read_end + mark->_pos;
1041     }
1042   return 0;
1043 }
1044
1045 void
1046 _IO_unsave_markers (_IO_FILE *fp)
1047 {
1048   struct _IO_marker *mark = fp->_markers;
1049   if (mark)
1050     {
1051 #ifdef TODO
1052       streampos offset = seekoff (0, ios::cur, ios::in);
1053       if (offset != EOF)
1054         {
1055           offset += eGptr () - Gbase ();
1056           for ( ; mark != NULL; mark = mark->_next)
1057             mark->set_streampos (mark->_pos + offset);
1058         }
1059     else
1060       {
1061         for ( ; mark != NULL; mark = mark->_next)
1062           mark->set_streampos (EOF);
1063       }
1064 #endif
1065       fp->_markers = 0;
1066     }
1067
1068   if (_IO_have_backup (fp))
1069     _IO_free_backup_area (fp);
1070 }
1071 libc_hidden_def (_IO_unsave_markers)
1072
1073 #if 0
1074 /* Seems not to be needed. --drepper */
1075 int
1076 _IO_nobackup_pbackfail (_IO_FILE *fp, int c)
1077 {
1078   if (fp->_IO_read_ptr > fp->_IO_read_base)
1079         fp->_IO_read_ptr--;
1080   if (c != EOF && *fp->_IO_read_ptr != c)
1081       *fp->_IO_read_ptr = c;
1082   return (unsigned char) c;
1083 }
1084 #endif
1085
1086 int
1087 _IO_default_pbackfail (_IO_FILE *fp, int c)
1088 {
1089   if (fp->_IO_read_ptr > fp->_IO_read_base && !_IO_in_backup (fp)
1090       && (unsigned char) fp->_IO_read_ptr[-1] == c)
1091     --fp->_IO_read_ptr;
1092   else
1093     {
1094       /* Need to handle a filebuf in write mode (switch to read mode). FIXME!*/
1095       if (!_IO_in_backup (fp))
1096         {
1097           /* We need to keep the invariant that the main get area
1098              logically follows the backup area.  */
1099           if (fp->_IO_read_ptr > fp->_IO_read_base && _IO_have_backup (fp))
1100             {
1101               if (save_for_backup (fp, fp->_IO_read_ptr))
1102                 return EOF;
1103             }
1104           else if (!_IO_have_backup (fp))
1105             {
1106               /* No backup buffer: allocate one. */
1107               /* Use nshort buffer, if unused? (probably not)  FIXME */
1108               int backup_size = 128;
1109               char *bbuf = (char *) malloc (backup_size);
1110               if (bbuf == NULL)
1111                 return EOF;
1112               fp->_IO_save_base = bbuf;
1113               fp->_IO_save_end = fp->_IO_save_base + backup_size;
1114               fp->_IO_backup_base = fp->_IO_save_end;
1115             }
1116           fp->_IO_read_base = fp->_IO_read_ptr;
1117           _IO_switch_to_backup_area (fp);
1118         }
1119       else if (fp->_IO_read_ptr <= fp->_IO_read_base)
1120         {
1121           /* Increase size of existing backup buffer. */
1122           _IO_size_t new_size;
1123           _IO_size_t old_size = fp->_IO_read_end - fp->_IO_read_base;
1124           char *new_buf;
1125           new_size = 2 * old_size;
1126           new_buf = (char *) malloc (new_size);
1127           if (new_buf == NULL)
1128             return EOF;
1129           memcpy (new_buf + (new_size - old_size), fp->_IO_read_base,
1130                   old_size);
1131           free (fp->_IO_read_base);
1132           _IO_setg (fp, new_buf, new_buf + (new_size - old_size),
1133                     new_buf + new_size);
1134           fp->_IO_backup_base = fp->_IO_read_ptr;
1135         }
1136
1137       *--fp->_IO_read_ptr = c;
1138     }
1139   return (unsigned char) c;
1140 }
1141 libc_hidden_def (_IO_default_pbackfail)
1142
1143 _IO_off64_t
1144 _IO_default_seek (_IO_FILE *fp, _IO_off64_t offset, int dir)
1145 {
1146   return _IO_pos_BAD;
1147 }
1148
1149 int
1150 _IO_default_stat (_IO_FILE *fp, void *st)
1151 {
1152   return EOF;
1153 }
1154
1155 _IO_ssize_t
1156 _IO_default_read (_IO_FILE *fp, void *data, _IO_ssize_t n)
1157 {
1158   return -1;
1159 }
1160
1161 _IO_ssize_t
1162 _IO_default_write (_IO_FILE *fp, const void *data, _IO_ssize_t n)
1163 {
1164   return 0;
1165 }
1166
1167 int
1168 _IO_default_showmanyc (_IO_FILE *fp)
1169 {
1170   return -1;
1171 }
1172
1173 void
1174 _IO_default_imbue (_IO_FILE *fp, void *locale)
1175 {
1176 }
1177
1178 _IO_ITER
1179 _IO_iter_begin (void)
1180 {
1181   return (_IO_ITER) _IO_list_all;
1182 }
1183 libc_hidden_def (_IO_iter_begin)
1184
1185 _IO_ITER
1186 _IO_iter_end (void)
1187 {
1188   return NULL;
1189 }
1190 libc_hidden_def (_IO_iter_end)
1191
1192 _IO_ITER
1193 _IO_iter_next (_IO_ITER iter)
1194 {
1195   return iter->_chain;
1196 }
1197 libc_hidden_def (_IO_iter_next)
1198
1199 _IO_FILE *
1200 _IO_iter_file (_IO_ITER iter)
1201 {
1202   return iter;
1203 }
1204 libc_hidden_def (_IO_iter_file)
1205
1206 void
1207 _IO_list_lock (void)
1208 {
1209 #ifdef _IO_MTSAFE_IO
1210   _IO_lock_lock (list_all_lock);
1211 #endif
1212 }
1213 libc_hidden_def (_IO_list_lock)
1214
1215 void
1216 _IO_list_unlock (void)
1217 {
1218 #ifdef _IO_MTSAFE_IO
1219   _IO_lock_unlock (list_all_lock);
1220 #endif
1221 }
1222 libc_hidden_def (_IO_list_unlock)
1223
1224 void
1225 _IO_list_resetlock (void)
1226 {
1227 #ifdef _IO_MTSAFE_IO
1228   _IO_lock_init (list_all_lock);
1229 #endif
1230 }
1231 libc_hidden_def (_IO_list_resetlock)
1232
1233
1234 #ifdef TODO
1235 #if defined(linux)
1236 #define IO_CLEANUP ;
1237 #endif
1238
1239 #ifdef IO_CLEANUP
1240   IO_CLEANUP
1241 #else
1242 struct __io_defs {
1243     __io_defs() { }
1244     ~__io_defs() { _IO_cleanup (); }
1245 };
1246 __io_defs io_defs__;
1247 #endif
1248
1249 #endif /* TODO */
1250
1251 #ifdef text_set_element
1252 text_set_element(__libc_atexit, _IO_cleanup);
1253 #endif