reactos/lib/sdk/crt/string/wcstombs.c

   1 /* Copyright (C) 1991, 1992, 1995, 1996, 1997 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <precomp.h>
  20 #include <wchar.h>
  21
  22 #ifndef EILSEQ
  23 #define EILSEQ EINVAL
  24 #endif
  25
  26
  27 static const wchar_t encoding_mask[] =
  28 {
  29   (~0x7ff&WCHAR_MAX), (~0xffff&WCHAR_MAX), (~0x1fffff&WCHAR_MAX), (~0x3ffffff&WCHAR_MAX)
  30 };
  31
  32 static const unsigned char encoding_byte[] =
  33 {
  34   0xc0, 0xe0, 0xf0, 0xf8, 0xfc
  35 };
  36
  37 /* We don't need the state really because we don't have shift states
  38    to maintain between calls to this function.  */
  39
  40 static mbstate_t mbstate_internal;
  41
  42
  43 mbstate_t __no_r_state;  /* Now defined in wcstombs.c.  */
  44 //extern mbstate_t __no_r_state;  /* Defined in mbtowc.c.  */
  45
  46 size_t
  47 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps);
  48
  49 /*
  50  * Convert the `wchar_t' string in PWCS to a multibyte character string
  51  * in S, writing no more than N characters.  Return the number of bytes
  52  * written, or (size_t) -1 if an invalid `wchar_t' was found.
  53  *
  54  * Attention: this function should NEVER be intentionally used.
  55  * The interface is completely stupid.  The state is shared between
  56  * all conversion functions.  You should use instead the restartable
  57  * version `wcsrtombs'.
  58  *
  59  * @implemented
  60  */
  61 size_t
  62 wcstombs (char *s, const wchar_t *pwcs, size_t n)
  63 {
  64   mbstate_t save_shift = __no_r_state;
  65   size_t written;
  66
  67   written = __wcsrtombs (s, &pwcs, n, &__no_r_state);
  68
  69   /* Restore the old shift state.  */
  70   __no_r_state = save_shift;
  71
  72   /* Return how many we wrote (or maybe an error).  */
  73   return written;
  74 }
  75
  76 size_t
  77 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps)
  78 {
  79   size_t written = 0;
  80   const wchar_t *run = *src;
  81
  82   if (ps == NULL)
  83     ps = &mbstate_internal;
  84
  85   if (dst == NULL)
  86     /* The LEN parameter has to be ignored if we don't actually write
  87        anything.  */
  88     len = ~0;
  89
  90   while (written < len)
  91     {
  92       wchar_t wc = *run++;
  93
  94 #if 0
  95       if (wc < 0 || wc > WCHAR_MAX)
  96         {
  97           /* This is no correct ISO 10646 character.  */
  98           __set_errno (EILSEQ);
  99           return (size_t) -1;
 100         }
 101 #endif
 102
 103       if (wc == L'\0')
 104         {
 105           /* Found the end.  */
 106           if (dst != NULL)
 107             *dst = '\0';
 108           *src = NULL;
 109           return written;
 110         }
 111       else if (wc < 0x80)
 112         {
 113           /* It's an one byte sequence.  */
 114           if (dst != NULL)
 115             *dst++ = (char) wc;
 116           ++written;
 117         }
 118       else
 119         {
 120           size_t step;
 121
 122           for (step = 2; step < 6; ++step)
 123             if ((wc & encoding_mask[step - 2]) == 0)
 124               break;
 125
 126           if (written + step >= len)
 127             /* Too long.  */
 128             break;
 129
 130           if (dst != NULL)
 131             {
 132               size_t cnt = step;
 133
 134               dst[0] = encoding_byte[cnt - 2];
 135
 136               --cnt;
 137               do
 138                 {
 139                   dst[cnt] = 0x80 | (wc & 0x3f);
 140                   wc >>= 6;
 141                 }
 142               while (--cnt > 0);
 143               dst[0] |= wc;
 144
 145               dst += step;
 146             }
 147
 148           written += step;
 149         }
 150     }
 151
 152   /* Store position of first unprocessed word.  */
 153   *src = run;
 154
 155   return written;
 156 }
 157 //weak_alias (__wcsrtombs, wcsrtombs)