libio/iofwide.c

   1 /* Copyright (C) 1999-2015 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 <libioP.h>
  28 #ifdef _LIBC
  29 # include <dlfcn.h>
  30 # include <wchar.h>
  31 #endif
  32 #include <assert.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #ifdef _LIBC
  37 # include <langinfo.h>
  38 # include <locale/localeinfo.h>
  39 # include <wcsmbs/wcsmbsload.h>
  40 # include <iconv/gconv_int.h>
  41 # include <shlib-compat.h>
  42 # include <sysdep.h>
  43 #endif
  44
  45
  46 /* Prototypes of libio's codecvt functions.  */
  47 static enum __codecvt_result do_out (struct _IO_codecvt *codecvt,
  48                                      __mbstate_t *statep,
  49                                      const wchar_t *from_start,
  50                                      const wchar_t *from_end,
  51                                      const wchar_t **from_stop, char *to_start,
  52                                      char *to_end, char **to_stop);
  53 static enum __codecvt_result do_unshift (struct _IO_codecvt *codecvt,
  54                                          __mbstate_t *statep, char *to_start,
  55                                          char *to_end, char **to_stop);
  56 static enum __codecvt_result do_in (struct _IO_codecvt *codecvt,
  57                                     __mbstate_t *statep,
  58                                     const char *from_start,
  59                                     const char *from_end,
  60                                     const char **from_stop, wchar_t *to_start,
  61                                     wchar_t *to_end, wchar_t **to_stop);
  62 static int do_encoding (struct _IO_codecvt *codecvt);
  63 static int do_length (struct _IO_codecvt *codecvt, __mbstate_t *statep,
  64                       const char *from_start,
  65                       const char *from_end, _IO_size_t max);
  66 static int do_max_length (struct _IO_codecvt *codecvt);
  67 static int do_always_noconv (struct _IO_codecvt *codecvt);
  68
  69
  70 /* The functions used in `codecvt' for libio are always the same.  */
  71 const struct _IO_codecvt __libio_codecvt =
  72 {
  73   .__codecvt_destr = NULL,              /* Destructor, never used.  */
  74   .__codecvt_do_out = do_out,
  75   .__codecvt_do_unshift = do_unshift,
  76   .__codecvt_do_in = do_in,
  77   .__codecvt_do_encoding = do_encoding,
  78   .__codecvt_do_always_noconv = do_always_noconv,
  79   .__codecvt_do_length = do_length,
  80   .__codecvt_do_max_length = do_max_length
  81 };
  82
  83
  84 /* Return orientation of stream.  If mode is nonzero try to change
  85    the orientation first.  */
  86 #undef _IO_fwide
  87 int
  88 _IO_fwide (fp, mode)
  89      _IO_FILE *fp;
  90      int mode;
  91 {
  92   /* Normalize the value.  */
  93   mode = mode < 0 ? -1 : (mode == 0 ? 0 : 1);
  94
  95 #if defined SHARED && defined _LIBC \
  96     && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
  97   if (__builtin_expect (&_IO_stdin_used == NULL, 0)
  98       && (fp == _IO_stdin || fp == _IO_stdout || fp == _IO_stderr))
  99     /* This is for a stream in the glibc 2.0 format.  */
 100     return -1;
 101 #endif
 102
 103   /* The orientation already has been determined.  */
 104   if (fp->_mode != 0
 105       /* Or the caller simply wants to know about the current orientation.  */
 106       || mode == 0)
 107     return fp->_mode;
 108
 109   /* Set the orientation appropriately.  */
 110   if (mode > 0)
 111     {
 112       struct _IO_codecvt *cc = fp->_codecvt = &fp->_wide_data->_codecvt;
 113
 114       fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
 115       fp->_wide_data->_IO_write_ptr = fp->_wide_data->_IO_write_base;
 116
 117       /* Get the character conversion functions based on the currently
 118          selected locale for LC_CTYPE.  */
 119 #ifdef _LIBC
 120       {
 121         /* Clear the state.  We start all over again.  */
 122         memset (&fp->_wide_data->_IO_state, '\0', sizeof (__mbstate_t));
 123         memset (&fp->_wide_data->_IO_last_state, '\0', sizeof (__mbstate_t));
 124
 125         struct gconv_fcts fcts;
 126         __wcsmbs_clone_conv (&fcts);
 127         assert (fcts.towc_nsteps == 1);
 128         assert (fcts.tomb_nsteps == 1);
 129
 130         /* The functions are always the same.  */
 131         *cc = __libio_codecvt;
 132
 133         cc->__cd_in.__cd.__nsteps = fcts.towc_nsteps;
 134         cc->__cd_in.__cd.__steps = fcts.towc;
 135
 136         cc->__cd_in.__cd.__data[0].__invocation_counter = 0;
 137         cc->__cd_in.__cd.__data[0].__internal_use = 1;
 138         cc->__cd_in.__cd.__data[0].__flags = __GCONV_IS_LAST;
 139         cc->__cd_in.__cd.__data[0].__statep = &fp->_wide_data->_IO_state;
 140
 141         cc->__cd_out.__cd.__nsteps = fcts.tomb_nsteps;
 142         cc->__cd_out.__cd.__steps = fcts.tomb;
 143
 144         cc->__cd_out.__cd.__data[0].__invocation_counter = 0;
 145         cc->__cd_out.__cd.__data[0].__internal_use = 1;
 146         cc->__cd_out.__cd.__data[0].__flags
 147           = __GCONV_IS_LAST | __GCONV_TRANSLIT;
 148         cc->__cd_out.__cd.__data[0].__statep = &fp->_wide_data->_IO_state;
 149       }
 150 #else
 151 # ifdef _GLIBCPP_USE_WCHAR_T
 152       {
 153         /* Determine internal and external character sets.
 154
 155            XXX For now we make our life easy: we assume a fixed internal
 156            encoding (as most sane systems have; hi HP/UX!).  If somebody
 157            cares about systems which changing internal charsets they
 158            should come up with a solution for the determination of the
 159            currently used internal character set.  */
 160         const char *internal_ccs = _G_INTERNAL_CCS;
 161         const char *external_ccs = NULL;
 162
 163 #  ifdef HAVE_NL_LANGINFO
 164         external_ccs = nl_langinfo (CODESET);
 165 #  endif
 166         if (external_ccs == NULL)
 167           external_ccs = "ISO-8859-1";
 168
 169         cc->__cd_in = iconv_open (internal_ccs, external_ccs);
 170         if (cc->__cd_in != (iconv_t) -1)
 171           cc->__cd_out = iconv_open (external_ccs, internal_ccs);
 172
 173         if (cc->__cd_in == (iconv_t) -1 || cc->__cd_out == (iconv_t) -1)
 174           {
 175             if (cc->__cd_in != (iconv_t) -1)
 176               iconv_close (cc->__cd_in);
 177             /* XXX */
 178             abort ();
 179           }
 180       }
 181 # else
 182 #  error "somehow determine this from LC_CTYPE"
 183 # endif
 184 #endif
 185
 186       /* From now on use the wide character callback functions.  */
 187       ((struct _IO_FILE_plus *) fp)->vtable = fp->_wide_data->_wide_vtable;
 188     }
 189
 190   /* Set the mode now.  */
 191   fp->_mode = mode;
 192
 193   return mode;
 194 }
 195
 196
 197 static enum __codecvt_result
 198 do_out (struct _IO_codecvt *codecvt, __mbstate_t *statep,
 199         const wchar_t *from_start, const wchar_t *from_end,
 200         const wchar_t **from_stop, char *to_start, char *to_end,
 201         char **to_stop)
 202 {
 203   enum __codecvt_result result;
 204
 205 #ifdef _LIBC
 206   struct __gconv_step *gs = codecvt->__cd_out.__cd.__steps;
 207   int status;
 208   size_t dummy;
 209   const unsigned char *from_start_copy = (unsigned char *) from_start;
 210
 211   codecvt->__cd_out.__cd.__data[0].__outbuf = (unsigned char *) to_start;
 212   codecvt->__cd_out.__cd.__data[0].__outbufend = (unsigned char *) to_end;
 213   codecvt->__cd_out.__cd.__data[0].__statep = statep;
 214
 215   __gconv_fct fct = gs->__fct;
 216 #ifdef PTR_DEMANGLE
 217   if (gs->__shlib_handle != NULL)
 218     PTR_DEMANGLE (fct);
 219 #endif
 220
 221   status = DL_CALL_FCT (fct,
 222                         (gs, codecvt->__cd_out.__cd.__data, &from_start_copy,
 223                          (const unsigned char *) from_end, NULL,
 224                          &dummy, 0, 0));
 225
 226   *from_stop = (wchar_t *) from_start_copy;
 227   *to_stop = (char *) codecvt->__cd_out.__cd.__data[0].__outbuf;
 228
 229   switch (status)
 230     {
 231     case __GCONV_OK:
 232     case __GCONV_EMPTY_INPUT:
 233       result = __codecvt_ok;
 234       break;
 235
 236     case __GCONV_FULL_OUTPUT:
 237     case __GCONV_INCOMPLETE_INPUT:
 238       result = __codecvt_partial;
 239       break;
 240
 241     default:
 242       result = __codecvt_error;
 243       break;
 244     }
 245 #else
 246 # ifdef _GLIBCPP_USE_WCHAR_T
 247   size_t res;
 248   const char *from_start_copy = (const char *) from_start;
 249   size_t from_len = from_end - from_start;
 250   char *to_start_copy = to_start;
 251   size_t to_len = to_end - to_start;
 252   res = iconv (codecvt->__cd_out, &from_start_copy, &from_len,
 253                &to_start_copy, &to_len);
 254
 255   if (res == 0 || from_len == 0)
 256     result = __codecvt_ok;
 257   else if (to_len < codecvt->__codecvt_do_max_length (codecvt))
 258     result = __codecvt_partial;
 259   else
 260     result = __codecvt_error;
 261
 262 # else
 263   /* Decide what to do.  */
 264   result = __codecvt_error;
 265 # endif
 266 #endif
 267
 268   return result;
 269 }
 270
 271
 272 static enum __codecvt_result
 273 do_unshift (struct _IO_codecvt *codecvt, __mbstate_t *statep,
 274             char *to_start, char *to_end, char **to_stop)
 275 {
 276   enum __codecvt_result result;
 277
 278 #ifdef _LIBC
 279   struct __gconv_step *gs = codecvt->__cd_out.__cd.__steps;
 280   int status;
 281   size_t dummy;
 282
 283   codecvt->__cd_out.__cd.__data[0].__outbuf = (unsigned char *) to_start;
 284   codecvt->__cd_out.__cd.__data[0].__outbufend = (unsigned char *) to_end;
 285   codecvt->__cd_out.__cd.__data[0].__statep = statep;
 286
 287   __gconv_fct fct = gs->__fct;
 288 #ifdef PTR_DEMANGLE
 289   if (gs->__shlib_handle != NULL)
 290     PTR_DEMANGLE (fct);
 291 #endif
 292
 293   status = DL_CALL_FCT (fct,
 294                         (gs, codecvt->__cd_out.__cd.__data, NULL, NULL,
 295                          NULL, &dummy, 1, 0));
 296
 297   *to_stop = (char *) codecvt->__cd_out.__cd.__data[0].__outbuf;
 298
 299   switch (status)
 300     {
 301     case __GCONV_OK:
 302     case __GCONV_EMPTY_INPUT:
 303       result = __codecvt_ok;
 304       break;
 305
 306     case __GCONV_FULL_OUTPUT:
 307     case __GCONV_INCOMPLETE_INPUT:
 308       result = __codecvt_partial;
 309       break;
 310
 311     default:
 312       result = __codecvt_error;
 313       break;
 314     }
 315 #else
 316 # ifdef _GLIBCPP_USE_WCHAR_T
 317   size_t res;
 318   char *to_start_copy = (char *) to_start;
 319   size_t to_len = to_end - to_start;
 320
 321   res = iconv (codecvt->__cd_out, NULL, NULL, &to_start_copy, &to_len);
 322
 323   if (res == 0)
 324     result = __codecvt_ok;
 325   else if (to_len < codecvt->__codecvt_do_max_length (codecvt))
 326     result = __codecvt_partial;
 327   else
 328     result = __codecvt_error;
 329 # else
 330   /* Decide what to do.  */
 331   result = __codecvt_error;
 332 # endif
 333 #endif
 334
 335   return result;
 336 }
 337
 338
 339 static enum __codecvt_result
 340 do_in (struct _IO_codecvt *codecvt, __mbstate_t *statep,
 341        const char *from_start, const char *from_end, const char **from_stop,
 342        wchar_t *to_start, wchar_t *to_end, wchar_t **to_stop)
 343 {
 344   enum __codecvt_result result;
 345
 346 #ifdef _LIBC
 347   struct __gconv_step *gs = codecvt->__cd_in.__cd.__steps;
 348   int status;
 349   size_t dummy;
 350   const unsigned char *from_start_copy = (unsigned char *) from_start;
 351
 352   codecvt->__cd_in.__cd.__data[0].__outbuf = (unsigned char *) to_start;
 353   codecvt->__cd_in.__cd.__data[0].__outbufend = (unsigned char *) to_end;
 354   codecvt->__cd_in.__cd.__data[0].__statep = statep;
 355
 356   __gconv_fct fct = gs->__fct;
 357 #ifdef PTR_DEMANGLE
 358   if (gs->__shlib_handle != NULL)
 359     PTR_DEMANGLE (fct);
 360 #endif
 361
 362   status = DL_CALL_FCT (fct,
 363                         (gs, codecvt->__cd_in.__cd.__data, &from_start_copy,
 364                          (const unsigned char *) from_end, NULL,
 365                          &dummy, 0, 0));
 366
 367   *from_stop = (const char *) from_start_copy;
 368   *to_stop = (wchar_t *) codecvt->__cd_in.__cd.__data[0].__outbuf;
 369
 370   switch (status)
 371     {
 372     case __GCONV_OK:
 373     case __GCONV_EMPTY_INPUT:
 374       result = __codecvt_ok;
 375       break;
 376
 377     case __GCONV_FULL_OUTPUT:
 378     case __GCONV_INCOMPLETE_INPUT:
 379       result = __codecvt_partial;
 380       break;
 381
 382     default:
 383       result = __codecvt_error;
 384       break;
 385     }
 386 #else
 387 # ifdef _GLIBCPP_USE_WCHAR_T
 388   size_t res;
 389   const char *from_start_copy = (const char *) from_start;
 390   size_t from_len = from_end - from_start;
 391   char *to_start_copy = (char *) from_start;
 392   size_t to_len = to_end - to_start;
 393
 394   res = iconv (codecvt->__cd_in, &from_start_copy, &from_len,
 395                &to_start_copy, &to_len);
 396
 397   if (res == 0)
 398     result = __codecvt_ok;
 399   else if (to_len == 0)
 400     result = __codecvt_partial;
 401   else if (from_len < codecvt->__codecvt_do_max_length (codecvt))
 402     result = __codecvt_partial;
 403   else
 404     result = __codecvt_error;
 405 # else
 406   /* Decide what to do.  */
 407   result = __codecvt_error;
 408 # endif
 409 #endif
 410
 411   return result;
 412 }
 413
 414
 415 static int
 416 do_encoding (struct _IO_codecvt *codecvt)
 417 {
 418 #ifdef _LIBC
 419   /* See whether the encoding is stateful.  */
 420   if (codecvt->__cd_in.__cd.__steps[0].__stateful)
 421     return -1;
 422   /* Fortunately not.  Now determine the input bytes for the conversion
 423      necessary for each wide character.  */
 424   if (codecvt->__cd_in.__cd.__steps[0].__min_needed_from
 425       != codecvt->__cd_in.__cd.__steps[0].__max_needed_from)
 426     /* Not a constant value.  */
 427     return 0;
 428
 429   return codecvt->__cd_in.__cd.__steps[0].__min_needed_from;
 430 #else
 431   /* Worst case scenario.  */
 432   return -1;
 433 #endif
 434 }
 435
 436
 437 static int
 438 do_always_noconv (struct _IO_codecvt *codecvt)
 439 {
 440   return 0;
 441 }
 442
 443
 444 static int
 445 do_length (struct _IO_codecvt *codecvt, __mbstate_t *statep,
 446            const char *from_start, const char *from_end, _IO_size_t max)
 447 {
 448   int result;
 449 #ifdef _LIBC
 450   const unsigned char *cp = (const unsigned char *) from_start;
 451   wchar_t to_buf[max];
 452   struct __gconv_step *gs = codecvt->__cd_in.__cd.__steps;
 453   size_t dummy;
 454
 455   codecvt->__cd_in.__cd.__data[0].__outbuf = (unsigned char *) to_buf;
 456   codecvt->__cd_in.__cd.__data[0].__outbufend = (unsigned char *) &to_buf[max];
 457   codecvt->__cd_in.__cd.__data[0].__statep = statep;
 458
 459   __gconv_fct fct = gs->__fct;
 460 #ifdef PTR_DEMANGLE
 461   if (gs->__shlib_handle != NULL)
 462     PTR_DEMANGLE (fct);
 463 #endif
 464
 465   DL_CALL_FCT (fct,
 466                (gs, codecvt->__cd_in.__cd.__data, &cp,
 467                 (const unsigned char *) from_end, NULL,
 468                 &dummy, 0, 0));
 469
 470   result = cp - (const unsigned char *) from_start;
 471 #else
 472 # ifdef _GLIBCPP_USE_WCHAR_T
 473   const char *from_start_copy = (const char *) from_start;
 474   size_t from_len = from_end - from_start;
 475   wchar_t to_buf[max];
 476   size_t res;
 477   char *to_start = (char *) to_buf;
 478
 479   res = iconv (codecvt->__cd_in, &from_start_copy, &from_len,
 480                &to_start, &max);
 481
 482   result = from_start_copy - (char *) from_start;
 483 # else
 484   /* Decide what to do.  */
 485   result = 0;
 486 # endif
 487 #endif
 488
 489   return result;
 490 }
 491
 492
 493 static int
 494 do_max_length (struct _IO_codecvt *codecvt)
 495 {
 496 #ifdef _LIBC
 497   return codecvt->__cd_in.__cd.__steps[0].__max_needed_from;
 498 #else
 499   return MB_CUR_MAX;
 500 #endif
 501 }