reactos/lib/msvcrt/stdlib/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 <msvcrt/stdlib.h>
  20 #include <msvcrt/wchar.h>
  21
  22 #include <msvcrt/errno.h>
  23 #include <msvcrt/internal/file.h>
  24
  25 #ifndef EILSEQ
  26 #define EILSEQ EINVAL
  27 #endif
  28
  29
  30 static const wchar_t encoding_mask[] =
  31 {
  32   (~0x7ff&WCHAR_MAX), (~0xffff&WCHAR_MAX), (~0x1fffff&WCHAR_MAX), (~0x3ffffff&WCHAR_MAX)
  33 };
  34
  35 static const unsigned char encoding_byte[] =
  36 {
  37   0xc0, 0xe0, 0xf0, 0xf8, 0xfc
  38 };
  39
  40 /* We don't need the state really because we don't have shift states
  41    to maintain between calls to this function.  */
  42 typedef int mbstate_t;
  43 static mbstate_t mbstate_internal;
  44
  45
  46 mbstate_t __no_r_state;  /* Now defined in wcstombs.c.  */
  47 //extern mbstate_t __no_r_state;  /* Defined in mbtowc.c.  */
  48
  49 size_t
  50 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps);
  51
  52 /*
  53  * Convert the `wchar_t' string in PWCS to a multibyte character string
  54  * in S, writing no more than N characters.  Return the number of bytes
  55  * written, or (size_t) -1 if an invalid `wchar_t' was found.
  56  *
  57  * Attention: this function should NEVER be intentionally used.
  58  * The interface is completely stupid.  The state is shared between
  59  * all conversion functions.  You should use instead the restartable
  60  * version `wcsrtombs'.
  61  *
  62  * @implemented
  63  */
  64 size_t
  65 wcstombs (char *s, const wchar_t *pwcs, size_t n)
  66 {
  67   mbstate_t save_shift = __no_r_state;
  68   size_t written;
  69
  70   written = __wcsrtombs (s, &pwcs, n, &__no_r_state);
  71
  72   /* Restore the old shift state.  */
  73   __no_r_state = save_shift;
  74
  75   /* Return how many we wrote (or maybe an error).  */
  76   return written;
  77 }
  78
  79 size_t
  80 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps)
  81 {
  82   size_t written = 0;
  83   const wchar_t *run = *src;
  84
  85   if (ps == NULL)
  86     ps = &mbstate_internal;
  87
  88   if (dst == NULL)
  89     /* The LEN parameter has to be ignored if we don't actually write
  90        anything.  */
  91     len = ~0;
  92
  93   while (written < len)
  94     {
  95       wchar_t wc = *run++;
  96
  97 #if 0
  98       if (wc < 0 || wc > WCHAR_MAX)
  99         {
 100           /* This is no correct ISO 10646 character.  */
 101           __set_errno (EILSEQ);
 102           return (size_t) -1;
 103         }
 104 #endif
 105
 106       if (wc == L'\0')
 107         {
 108           /* Found the end.  */
 109           if (dst != NULL)
 110             *dst = '\0';
 111           *src = NULL;
 112           return written;
 113         }
 114       else if (wc < 0x80)
 115         {
 116           /* It's an one byte sequence.  */
 117           if (dst != NULL)
 118             *dst++ = (char) wc;
 119           ++written;
 120         }
 121       else
 122         {
 123           size_t step;
 124
 125           for (step = 2; step < 6; ++step)
 126             if ((wc & encoding_mask[step - 2]) == 0)
 127               break;
 128
 129           if (written + step >= len)
 130             /* Too long.  */
 131             break;
 132
 133           if (dst != NULL)
 134             {
 135               size_t cnt = step;
 136
 137               dst[0] = encoding_byte[cnt - 2];
 138
 139               --cnt;
 140               do
 141                 {
 142                   dst[cnt] = 0x80 | (wc & 0x3f);
 143                   wc >>= 6;
 144                 }
 145               while (--cnt > 0);
 146               dst[0] |= wc;
 147
 148               dst += step;
 149             }
 150
 151           written += step;
 152         }
 153     }
 154
 155   /* Store position of first unprocessed word.  */
 156   *src = run;
 157
 158   return written;
 159 }
 160 //weak_alias (__wcsrtombs, wcsrtombs)