libio/iofwide.c

   1 /* Copyright (C) 1999-2024 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    <https://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 #include <dlfcn.h>
  29 #include <wchar.h>
  30 #include <assert.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 #include <langinfo.h>
  35 #include <locale/localeinfo.h>
  36 #include <wcsmbs/wcsmbsload.h>
  37 #include <iconv/gconv_int.h>
  38 #include <shlib-compat.h>
  39 #include <pointer_guard.h>
  40
  41
  42 /* Return orientation of stream.  If mode is nonzero try to change
  43    the orientation first.  */
  44 #undef _IO_fwide
  45 int
  46 _IO_fwide (FILE *fp, int mode)
  47 {
  48   /* Normalize the value.  */
  49   mode = mode < 0 ? -1 : (mode == 0 ? 0 : 1);
  50
  51 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
  52   if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp))
  53     /* This is for a stream in the glibc 2.0 format.  */
  54     return -1;
  55 #endif
  56
  57   /* The orientation already has been determined.  */
  58   if (fp->_mode != 0
  59       /* Or the caller simply wants to know about the current orientation.  */
  60       || mode == 0)
  61     return fp->_mode;
  62
  63   /* Set the orientation appropriately.  */
  64   if (mode > 0)
  65     {
  66       struct _IO_codecvt *cc = fp->_codecvt = &fp->_wide_data->_codecvt;
  67
  68       fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
  69       fp->_wide_data->_IO_write_ptr = fp->_wide_data->_IO_write_base;
  70
  71       /* Get the character conversion functions based on the currently
  72          selected locale for LC_CTYPE.  */
  73       {
  74         /* Clear the state.  We start all over again.  */
  75         memset (&fp->_wide_data->_IO_state, '\0', sizeof (__mbstate_t));
  76         memset (&fp->_wide_data->_IO_last_state, '\0', sizeof (__mbstate_t));
  77
  78         struct gconv_fcts fcts;
  79         __wcsmbs_clone_conv (&fcts);
  80         assert (fcts.towc_nsteps == 1);
  81         assert (fcts.tomb_nsteps == 1);
  82
  83         cc->__cd_in.step = fcts.towc;
  84
  85         cc->__cd_in.step_data.__invocation_counter = 0;
  86         cc->__cd_in.step_data.__internal_use = 1;
  87         cc->__cd_in.step_data.__flags = __GCONV_IS_LAST;
  88         cc->__cd_in.step_data.__statep = &fp->_wide_data->_IO_state;
  89
  90         cc->__cd_out.step = fcts.tomb;
  91
  92         cc->__cd_out.step_data.__invocation_counter = 0;
  93         cc->__cd_out.step_data.__internal_use = 1;
  94         cc->__cd_out.step_data.__flags = __GCONV_IS_LAST | __GCONV_TRANSLIT;
  95         cc->__cd_out.step_data.__statep = &fp->_wide_data->_IO_state;
  96       }
  97
  98       /* From now on use the wide character callback functions.  */
  99       _IO_JUMPS_FILE_plus (fp) = fp->_wide_data->_wide_vtable;
 100     }
 101
 102   /* Set the mode now.  */
 103   fp->_mode = mode;
 104
 105   return mode;
 106 }
 107
 108
 109 enum __codecvt_result
 110 __libio_codecvt_out (struct _IO_codecvt *codecvt, __mbstate_t *statep,
 111                      const wchar_t *from_start, const wchar_t *from_end,
 112                      const wchar_t **from_stop, char *to_start, char *to_end,
 113                      char **to_stop)
 114 {
 115   enum __codecvt_result result;
 116
 117   struct __gconv_step *gs = codecvt->__cd_out.step;
 118   int status;
 119   size_t dummy;
 120   const unsigned char *from_start_copy = (unsigned char *) from_start;
 121
 122   codecvt->__cd_out.step_data.__outbuf = (unsigned char *) to_start;
 123   codecvt->__cd_out.step_data.__outbufend = (unsigned char *) to_end;
 124   codecvt->__cd_out.step_data.__statep = statep;
 125
 126   __gconv_fct fct = gs->__fct;
 127   if (gs->__shlib_handle != NULL)
 128     PTR_DEMANGLE (fct);
 129
 130   status = DL_CALL_FCT (fct,
 131                         (gs, &codecvt->__cd_out.step_data, &from_start_copy,
 132                          (const unsigned char *) from_end, NULL,
 133                          &dummy, 0, 0));
 134
 135   *from_stop = (wchar_t *) from_start_copy;
 136   *to_stop = (char *) codecvt->__cd_out.step_data.__outbuf;
 137
 138   switch (status)
 139     {
 140     case __GCONV_OK:
 141     case __GCONV_EMPTY_INPUT:
 142       result = __codecvt_ok;
 143       break;
 144
 145     case __GCONV_FULL_OUTPUT:
 146     case __GCONV_INCOMPLETE_INPUT:
 147       result = __codecvt_partial;
 148       break;
 149
 150     default:
 151       result = __codecvt_error;
 152       break;
 153     }
 154
 155   return result;
 156 }
 157
 158
 159 enum __codecvt_result
 160 __libio_codecvt_in (struct _IO_codecvt *codecvt, __mbstate_t *statep,
 161                     const char *from_start, const char *from_end,
 162                     const char **from_stop,
 163                     wchar_t *to_start, wchar_t *to_end, wchar_t **to_stop)
 164 {
 165   enum __codecvt_result result;
 166
 167   struct __gconv_step *gs = codecvt->__cd_in.step;
 168   int status;
 169   size_t dummy;
 170   const unsigned char *from_start_copy = (unsigned char *) from_start;
 171
 172   codecvt->__cd_in.step_data.__outbuf = (unsigned char *) to_start;
 173   codecvt->__cd_in.step_data.__outbufend = (unsigned char *) to_end;
 174   codecvt->__cd_in.step_data.__statep = statep;
 175
 176   __gconv_fct fct = gs->__fct;
 177   if (gs->__shlib_handle != NULL)
 178     PTR_DEMANGLE (fct);
 179
 180   status = DL_CALL_FCT (fct,
 181                         (gs, &codecvt->__cd_in.step_data, &from_start_copy,
 182                          (const unsigned char *) from_end, NULL,
 183                          &dummy, 0, 0));
 184
 185   *from_stop = (const char *) from_start_copy;
 186   *to_stop = (wchar_t *) codecvt->__cd_in.step_data.__outbuf;
 187
 188   switch (status)
 189     {
 190     case __GCONV_OK:
 191     case __GCONV_EMPTY_INPUT:
 192       result = __codecvt_ok;
 193       break;
 194
 195     case __GCONV_FULL_OUTPUT:
 196     case __GCONV_INCOMPLETE_INPUT:
 197       result = __codecvt_partial;
 198       break;
 199
 200     default:
 201       result = __codecvt_error;
 202       break;
 203     }
 204
 205   return result;
 206 }
 207
 208
 209 int
 210 __libio_codecvt_encoding (struct _IO_codecvt *codecvt)
 211 {
 212   /* See whether the encoding is stateful.  */
 213   if (codecvt->__cd_in.step->__stateful)
 214     return -1;
 215   /* Fortunately not.  Now determine the input bytes for the conversion
 216      necessary for each wide character.  */
 217   if (codecvt->__cd_in.step->__min_needed_from
 218       != codecvt->__cd_in.step->__max_needed_from)
 219     /* Not a constant value.  */
 220     return 0;
 221
 222   return codecvt->__cd_in.step->__min_needed_from;
 223 }
 224
 225
 226 int
 227 __libio_codecvt_length (struct _IO_codecvt *codecvt, __mbstate_t *statep,
 228                         const char *from_start, const char *from_end,
 229                         size_t max)
 230 {
 231   int result;
 232   const unsigned char *cp = (const unsigned char *) from_start;
 233   wchar_t to_buf[max];
 234   struct __gconv_step *gs = codecvt->__cd_in.step;
 235   size_t dummy;
 236
 237   codecvt->__cd_in.step_data.__outbuf = (unsigned char *) to_buf;
 238   codecvt->__cd_in.step_data.__outbufend = (unsigned char *) &to_buf[max];
 239   codecvt->__cd_in.step_data.__statep = statep;
 240
 241   __gconv_fct fct = gs->__fct;
 242   if (gs->__shlib_handle != NULL)
 243     PTR_DEMANGLE (fct);
 244
 245   DL_CALL_FCT (fct,
 246                (gs, &codecvt->__cd_in.step_data, &cp,
 247                 (const unsigned char *) from_end, NULL,
 248                 &dummy, 0, 0));
 249
 250   result = cp - (const unsigned char *) from_start;
 251
 252   return result;
 253 }