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/wchar.h>
  24
  25 #ifndef EILSEQ
  26 #define EILSEQ EINVAL
  27 #endif
  28
  29
  30 static const wchar_t encoding_mask[] =
  31 {
  32   ~0x7ff, ~0xffff, ~0x1fffff, ~0x3ffffff
  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 static mbstate_t internal;
  43
  44
  45 extern mbstate_t __no_r_state;  /* Defined in mbtowc.c.  */
  46
  47 size_t
  48 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps);
  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 size_t
  59 wcstombs (char *s, const wchar_t *pwcs, size_t n)
  60 {
  61   mbstate_t save_shift = __no_r_state;
  62   size_t written;
  63
  64   written = __wcsrtombs (s, &pwcs, n, &__no_r_state);
  65
  66   /* Restore the old shift state.  */
  67   __no_r_state = save_shift;
  68
  69   /* Return how many we wrote (or maybe an error).  */
  70   return written;
  71 }
  72
  73 size_t
  74 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps)
  75 {
  76   size_t written = 0;
  77   const wchar_t *run = *src;
  78
  79   if (ps == NULL)
  80     ps = &internal;
  81
  82   if (dst == NULL)
  83     /* The LEN parameter has to be ignored if we don't actually write
  84        anything.  */
  85     len = ~0;
  86
  87   while (written < len)
  88     {
  89       wchar_t wc = *run++;
  90
  91       if (wc < 0 || wc > 0x7fffffff)
  92         {
  93           /* This is no correct ISO 10646 character.  */
  94           __set_errno (EILSEQ);
  95           return (size_t) -1;
  96         }
  97
  98       if (wc == L'\0')
  99         {
 100           /* Found the end.  */
 101           if (dst != NULL)
 102             *dst = '\0';
 103           *src = NULL;
 104           return written;
 105         }
 106       else if (wc < 0x80)
 107         {
 108           /* It's an one byte sequence.  */
 109           if (dst != NULL)
 110             *dst++ = (char) wc;
 111           ++written;
 112         }
 113       else
 114         {
 115           size_t step;
 116
 117           for (step = 2; step < 6; ++step)
 118             if ((wc & encoding_mask[step - 2]) == 0)
 119               break;
 120
 121           if (written + step >= len)
 122             /* Too long.  */
 123             break;
 124
 125           if (dst != NULL)
 126             {
 127               size_t cnt = step;
 128
 129               dst[0] = encoding_byte[cnt - 2];
 130
 131               --cnt;
 132               do
 133                 {
 134                   dst[cnt] = 0x80 | (wc & 0x3f);
 135                   wc >>= 6;
 136                 }
 137               while (--cnt > 0);
 138               dst[0] |= wc;
 139
 140               dst += step;
 141             }
 142
 143           written += step;
 144         }
 145     }
 146
 147   /* Store position of first unprocessed word.  */
 148   *src = run;
 149
 150   return written;
 151 }
 152 //weak_alias (__wcsrtombs, wcsrtombs)