libio/wstrops.c

   1 /* Copyright (C) 1993-2018 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 #include <assert.h>
  28 #include "strfile.h"
  29 #include "libioP.h"
  30 #include <string.h>
  31 #include <wchar.h>
  32 #include <stdio_ext.h>
  33
  34 void
  35 _IO_wstr_init_static (FILE *fp, wchar_t *ptr, size_t size,
  36                       wchar_t *pstart)
  37 {
  38   wchar_t *end;
  39
  40   if (size == 0)
  41     end = ptr + __wcslen (ptr);
  42   else if ((size_t) ptr + size * sizeof (wchar_t) > (size_t) ptr)
  43     end = ptr + size;
  44   else
  45     /* Even for misaligned ptr make sure there is integral number of wide
  46        characters.  */
  47     end = ptr + (-1 - (size_t) ptr) / sizeof (wchar_t);
  48   _IO_wsetb (fp, ptr, end, 0);
  49
  50   fp->_wide_data->_IO_write_base = ptr;
  51   fp->_wide_data->_IO_read_base = ptr;
  52   fp->_wide_data->_IO_read_ptr = ptr;
  53   if (pstart)
  54     {
  55       fp->_wide_data->_IO_write_ptr = pstart;
  56       fp->_wide_data->_IO_write_end = end;
  57       fp->_wide_data->_IO_read_end = pstart;
  58     }
  59   else
  60     {
  61       fp->_wide_data->_IO_write_ptr = ptr;
  62       fp->_wide_data->_IO_write_end = ptr;
  63       fp->_wide_data->_IO_read_end = end;
  64     }
  65   /* A null _allocate_buffer function flags the strfile as being static. */
  66   (((_IO_strfile *) fp)->_s._allocate_buffer) = (_IO_alloc_type)0;
  67 }
  68
  69 wint_t
  70 _IO_wstr_overflow (FILE *fp, wint_t c)
  71 {
  72   int flush_only = c == WEOF;
  73   size_t pos;
  74   if (fp->_flags & _IO_NO_WRITES)
  75       return flush_only ? 0 : WEOF;
  76   if ((fp->_flags & _IO_TIED_PUT_GET) && !(fp->_flags & _IO_CURRENTLY_PUTTING))
  77     {
  78       fp->_flags |= _IO_CURRENTLY_PUTTING;
  79       fp->_wide_data->_IO_write_ptr = fp->_wide_data->_IO_read_ptr;
  80       fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
  81     }
  82   pos = fp->_wide_data->_IO_write_ptr - fp->_wide_data->_IO_write_base;
  83   if (pos >= (size_t) (_IO_wblen (fp) + flush_only))
  84     {
  85       if (fp->_flags2 & _IO_FLAGS2_USER_WBUF) /* not allowed to enlarge */
  86         return WEOF;
  87       else
  88         {
  89           wchar_t *new_buf;
  90           wchar_t *old_buf = fp->_wide_data->_IO_buf_base;
  91           size_t old_wblen = _IO_wblen (fp);
  92           size_t new_size = 2 * old_wblen + 100;
  93
  94           if (__glibc_unlikely (new_size < old_wblen)
  95               || __glibc_unlikely (new_size > SIZE_MAX / sizeof (wchar_t)))
  96             return EOF;
  97
  98           new_buf
  99             = (wchar_t *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (new_size
 100                                                                         * sizeof (wchar_t));
 101           if (new_buf == NULL)
 102             {
 103               /*          __ferror(fp) = 1; */
 104               return WEOF;
 105             }
 106           if (old_buf)
 107             {
 108               __wmemcpy (new_buf, old_buf, old_wblen);
 109               (*((_IO_strfile *) fp)->_s._free_buffer) (old_buf);
 110               /* Make sure _IO_setb won't try to delete _IO_buf_base. */
 111               fp->_wide_data->_IO_buf_base = NULL;
 112             }
 113
 114           __wmemset (new_buf + old_wblen, L'\0', new_size - old_wblen);
 115
 116           _IO_wsetb (fp, new_buf, new_buf + new_size, 1);
 117           fp->_wide_data->_IO_read_base =
 118             new_buf + (fp->_wide_data->_IO_read_base - old_buf);
 119           fp->_wide_data->_IO_read_ptr =
 120             new_buf + (fp->_wide_data->_IO_read_ptr - old_buf);
 121           fp->_wide_data->_IO_read_end =
 122             new_buf + (fp->_wide_data->_IO_read_end - old_buf);
 123           fp->_wide_data->_IO_write_ptr =
 124             new_buf + (fp->_wide_data->_IO_write_ptr - old_buf);
 125
 126           fp->_wide_data->_IO_write_base = new_buf;
 127           fp->_wide_data->_IO_write_end = fp->_wide_data->_IO_buf_end;
 128         }
 129     }
 130
 131   if (!flush_only)
 132     *fp->_wide_data->_IO_write_ptr++ = c;
 133   if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_read_end)
 134     fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
 135   return c;
 136 }
 137
 138
 139 wint_t
 140 _IO_wstr_underflow (FILE *fp)
 141 {
 142   if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_read_end)
 143     fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
 144   if ((fp->_flags & _IO_TIED_PUT_GET) && (fp->_flags & _IO_CURRENTLY_PUTTING))
 145     {
 146       fp->_flags &= ~_IO_CURRENTLY_PUTTING;
 147       fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_write_ptr;
 148       fp->_wide_data->_IO_write_ptr = fp->_wide_data->_IO_write_end;
 149     }
 150   if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
 151     return *fp->_wide_data->_IO_read_ptr;
 152   else
 153     return WEOF;
 154 }
 155
 156
 157 /* The size of the valid part of the buffer.  */
 158 ssize_t
 159 _IO_wstr_count (FILE *fp)
 160 {
 161   struct _IO_wide_data *wd = fp->_wide_data;
 162
 163   return ((wd->_IO_write_ptr > wd->_IO_read_end
 164            ? wd->_IO_write_ptr : wd->_IO_read_end)
 165           - wd->_IO_read_base);
 166 }
 167
 168
 169 static int
 170 enlarge_userbuf (FILE *fp, off64_t offset, int reading)
 171 {
 172   if ((ssize_t) offset <= _IO_wblen (fp))
 173     return 0;
 174
 175   struct _IO_wide_data *wd = fp->_wide_data;
 176
 177   ssize_t oldend = wd->_IO_write_end - wd->_IO_write_base;
 178
 179   /* Try to enlarge the buffer.  */
 180   if (fp->_flags2 & _IO_FLAGS2_USER_WBUF)
 181     /* User-provided buffer.  */
 182     return 1;
 183
 184   size_t newsize = offset + 100;
 185   if (__glibc_unlikely (newsize > SIZE_MAX / sizeof (wchar_t)))
 186     return 1;
 187
 188   wchar_t *oldbuf = wd->_IO_buf_base;
 189   wchar_t *newbuf
 190     = (wchar_t *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (newsize
 191                                                                 * sizeof (wchar_t));
 192   if (newbuf == NULL)
 193     return 1;
 194
 195   if (oldbuf != NULL)
 196     {
 197       __wmemcpy (newbuf, oldbuf, _IO_wblen (fp));
 198       (*((_IO_strfile *) fp)->_s._free_buffer) (oldbuf);
 199       /* Make sure _IO_setb won't try to delete
 200          _IO_buf_base. */
 201       wd->_IO_buf_base = NULL;
 202     }
 203
 204   _IO_wsetb (fp, newbuf, newbuf + newsize, 1);
 205
 206   if (reading)
 207     {
 208       wd->_IO_write_base = newbuf + (wd->_IO_write_base - oldbuf);
 209       wd->_IO_write_ptr = newbuf + (wd->_IO_write_ptr - oldbuf);
 210       wd->_IO_write_end = newbuf + (wd->_IO_write_end - oldbuf);
 211       wd->_IO_read_ptr = newbuf + (wd->_IO_read_ptr - oldbuf);
 212
 213       wd->_IO_read_base = newbuf;
 214       wd->_IO_read_end = wd->_IO_buf_end;
 215     }
 216   else
 217     {
 218       wd->_IO_read_base = newbuf + (wd->_IO_read_base - oldbuf);
 219       wd->_IO_read_ptr = newbuf + (wd->_IO_read_ptr - oldbuf);
 220       wd->_IO_read_end = newbuf + (wd->_IO_read_end - oldbuf);
 221       wd->_IO_write_ptr = newbuf + (wd->_IO_write_ptr - oldbuf);
 222
 223       wd->_IO_write_base = newbuf;
 224       wd->_IO_write_end = wd->_IO_buf_end;
 225     }
 226
 227   /* Clear the area between the last write position and th
 228      new position.  */
 229   assert (offset >= oldend);
 230   if (reading)
 231     __wmemset (wd->_IO_read_base + oldend, L'\0', offset - oldend);
 232   else
 233     __wmemset (wd->_IO_write_base + oldend, L'\0', offset - oldend);
 234
 235   return 0;
 236 }
 237
 238 static void
 239 _IO_wstr_switch_to_get_mode (FILE *fp)
 240 {
 241   if (_IO_in_backup (fp))
 242     fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_backup_base;
 243   else
 244     {
 245       fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_buf_base;
 246       if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_read_end)
 247         fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
 248     }
 249   fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_write_ptr;
 250   fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
 251
 252   fp->_flags &= ~_IO_CURRENTLY_PUTTING;
 253 }
 254
 255 off64_t
 256 _IO_wstr_seekoff (FILE *fp, off64_t offset, int dir, int mode)
 257 {
 258   off64_t new_pos;
 259
 260   if (mode == 0 && (fp->_flags & _IO_TIED_PUT_GET))
 261     mode = (fp->_flags & _IO_CURRENTLY_PUTTING ? _IOS_OUTPUT : _IOS_INPUT);
 262
 263   bool was_writing = (fp->_wide_data->_IO_write_ptr >
 264                         fp->_wide_data->_IO_write_base
 265                      || _IO_in_put_mode (fp));
 266   if (was_writing)
 267     _IO_wstr_switch_to_get_mode (fp);
 268
 269   if (mode == 0)
 270     {
 271       new_pos = (fp->_wide_data->_IO_write_ptr
 272                  - fp->_wide_data->_IO_write_base);
 273     }
 274   else
 275     {
 276       ssize_t cur_size = _IO_wstr_count (fp);
 277       new_pos = EOF;
 278
 279       /* Move the get pointer, if requested. */
 280       if (mode & _IOS_INPUT)
 281         {
 282           ssize_t base;
 283           switch (dir)
 284             {
 285             case _IO_seek_set:
 286               base = 0;
 287               break;
 288             case _IO_seek_cur:
 289               base = (fp->_wide_data->_IO_read_ptr
 290                      - fp->_wide_data->_IO_read_base);
 291               break;
 292             default: /* case _IO_seek_end: */
 293               base = cur_size;
 294               break;
 295             }
 296           ssize_t maxval = SSIZE_MAX/sizeof (wchar_t) - base;
 297           if (offset < -base || offset > maxval)
 298             {
 299               __set_errno (EINVAL);
 300               return EOF;
 301             }
 302           base += offset;
 303           if (base > cur_size
 304               && enlarge_userbuf (fp, base, 1) != 0)
 305             return EOF;
 306           fp->_wide_data->_IO_read_ptr = (fp->_wide_data->_IO_read_base
 307                                           + base);
 308           fp->_wide_data->_IO_read_end = (fp->_wide_data->_IO_read_base
 309                                           + cur_size);
 310           new_pos = offset;
 311         }
 312
 313       /* Move the put pointer, if requested. */
 314       if (mode & _IOS_OUTPUT)
 315         {
 316           ssize_t base;
 317           switch (dir)
 318             {
 319             case _IO_seek_set:
 320               base = 0;
 321               break;
 322             case _IO_seek_cur:
 323               base = (fp->_wide_data->_IO_write_ptr
 324                      - fp->_wide_data->_IO_write_base);
 325               break;
 326             default: /* case _IO_seek_end: */
 327               base = cur_size;
 328               break;
 329             }
 330           ssize_t maxval = SSIZE_MAX/sizeof (wchar_t) - base;
 331           if (offset < -base || offset > maxval)
 332             {
 333               __set_errno (EINVAL);
 334               return EOF;
 335             }
 336           base += offset;
 337           if (base > cur_size
 338               && enlarge_userbuf (fp, base, 0) != 0)
 339             return EOF;
 340           fp->_wide_data->_IO_write_ptr = (fp->_wide_data->_IO_write_base
 341                                            + base);
 342           new_pos = base;
 343         }
 344     }
 345   return new_pos;
 346 }
 347
 348 wint_t
 349 _IO_wstr_pbackfail (FILE *fp, wint_t c)
 350 {
 351   if ((fp->_flags & _IO_NO_WRITES) && c != WEOF)
 352     return WEOF;
 353   return _IO_wdefault_pbackfail (fp, c);
 354 }
 355
 356 void
 357 _IO_wstr_finish (FILE *fp, int dummy)
 358 {
 359   if (fp->_wide_data->_IO_buf_base && !(fp->_flags2 & _IO_FLAGS2_USER_WBUF))
 360     (((_IO_strfile *) fp)->_s._free_buffer) (fp->_wide_data->_IO_buf_base);
 361   fp->_wide_data->_IO_buf_base = NULL;
 362
 363   _IO_wdefault_finish (fp, 0);
 364 }
 365
 366 const struct _IO_jump_t _IO_wstr_jumps libio_vtable =
 367 {
 368   JUMP_INIT_DUMMY,
 369   JUMP_INIT(finish, _IO_wstr_finish),
 370   JUMP_INIT(overflow, (_IO_overflow_t) _IO_wstr_overflow),
 371   JUMP_INIT(underflow, (_IO_underflow_t) _IO_wstr_underflow),
 372   JUMP_INIT(uflow, (_IO_underflow_t) _IO_wdefault_uflow),
 373   JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
 374   JUMP_INIT(xsputn, _IO_wdefault_xsputn),
 375   JUMP_INIT(xsgetn, _IO_wdefault_xsgetn),
 376   JUMP_INIT(seekoff, _IO_wstr_seekoff),
 377   JUMP_INIT(seekpos, _IO_default_seekpos),
 378   JUMP_INIT(setbuf, _IO_default_setbuf),
 379   JUMP_INIT(sync, _IO_default_sync),
 380   JUMP_INIT(doallocate, _IO_wdefault_doallocate),
 381   JUMP_INIT(read, _IO_default_read),
 382   JUMP_INIT(write, _IO_default_write),
 383   JUMP_INIT(seek, _IO_default_seek),
 384   JUMP_INIT(close, _IO_default_close),
 385   JUMP_INIT(stat, _IO_default_stat),
 386   JUMP_INIT(showmanyc, _IO_default_showmanyc),
 387   JUMP_INIT(imbue, _IO_default_imbue)
 388 };