wcsmbs/wctob.c

   1 /* Copyright (C) 1996-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <dlfcn.h>
  20 #include <gconv.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <wchar.h>
  24 #include <wcsmbsload.h>
  25
  26 #include <sysdep.h>
  27
  28
  29 int
  30 wctob (wint_t c)
  31 {
  32   unsigned char buf[MB_LEN_MAX];
  33   struct __gconv_step_data data;
  34   wchar_t inbuf[1];
  35   wchar_t *inptr = inbuf;
  36   size_t dummy;
  37   int status;
  38   const struct gconv_fcts *fcts;
  39
  40   if (c == WEOF)
  41     return EOF;
  42
  43   /* We know that only ASCII compatible encodings are used for the
  44      locale and that the wide character encoding is ISO 10646.  */
  45   if (c >= L'\0' && c <= L'\x7f')
  46     return (int) c;
  47
  48   /* Tell where we want the result.  */
  49   data.__outbuf = buf;
  50   data.__outbufend = buf + MB_LEN_MAX;
  51   data.__invocation_counter = 0;
  52   data.__internal_use = 1;
  53   data.__flags = __GCONV_IS_LAST;
  54   data.__statep = &data.__state;
  55
  56   /* Make sure we start in the initial state.  */
  57   memset (&data.__state, '\0', sizeof (mbstate_t));
  58
  59   /* Get the conversion functions.  */
  60   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  61
  62   /* Create the input string.  */
  63   inbuf[0] = c;
  64
  65   const unsigned char *argptr = (const unsigned char *) inptr;
  66   __gconv_fct fct = fcts->tomb->__fct;
  67 #ifdef PTR_DEMANGLE
  68   if (fcts->tomb->__shlib_handle != NULL)
  69     PTR_DEMANGLE (fct);
  70 #endif
  71   status = DL_CALL_FCT (fct,
  72                         (fcts->tomb, &data, &argptr,
  73                          argptr + sizeof (inbuf[0]), NULL, &dummy, 0, 1));
  74
  75   /* The conversion failed or the output is too long.  */
  76   if ((status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
  77        && status != __GCONV_EMPTY_INPUT)
  78       || data.__outbuf != (unsigned char *) (buf + 1))
  79     return EOF;
  80
  81   return buf[0];
  82 }