libs/wine/utf8.c

   1 /*
   2  * UTF-8 support routines
   3  *
   4  * Copyright 2000 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include <string.h>
  22
  23 #include "wine/unicode.h"
  24
  25 /* number of following bytes in sequence based on first byte value (for bytes above 0x7f) */
  26 static const char utf8_length[128] =
  27 {
  28     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x80-0x8f */
  29     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x90-0x9f */
  30     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xa0-0xaf */
  31     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xb0-0xbf */
  32     0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 0xc0-0xcf */
  33     1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 0xd0-0xdf */
  34     2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, /* 0xe0-0xef */
  35     3,3,3,3,3,0,0,0,0,0,0,0,0,0,0,0  /* 0xf0-0xff */
  36 };
  37
  38 /* first byte mask depending on UTF-8 sequence length */
  39 static const unsigned char utf8_mask[4] = { 0x7f, 0x1f, 0x0f, 0x07 };
  40
  41 /* minimum Unicode value depending on UTF-8 sequence length */
  42 static const unsigned int utf8_minval[4] = { 0x0, 0x80, 0x800, 0x10000 };
  43
  44
  45 /* get the next char value taking surrogates into account */
  46 static inline unsigned int get_surrogate_value( const WCHAR *src, unsigned int srclen )
  47 {
  48     if (src[0] >= 0xd800 && src[0] <= 0xdfff)  /* surrogate pair */
  49     {
  50         if (src[0] > 0xdbff || /* invalid high surrogate */
  51             srclen <= 1 ||     /* missing low surrogate */
  52             src[1] < 0xdc00 || src[1] > 0xdfff) /* invalid low surrogate */
  53             return 0;
  54         return 0x10000 + ((src[0] & 0x3ff) << 10) + (src[1] & 0x3ff);
  55     }
  56     return src[0];
  57 }
  58
  59 /* query necessary dst length for src string */
  60 static inline int get_length_wcs_utf8( int flags, const WCHAR *src, unsigned int srclen )
  61 {
  62     int len;
  63     unsigned int val;
  64
  65     for (len = 0; srclen; srclen--, src++)
  66     {
  67         if (*src < 0x80)  /* 0x00-0x7f: 1 byte */
  68         {
  69             len++;
  70             continue;
  71         }
  72         if (*src < 0x800)  /* 0x80-0x7ff: 2 bytes */
  73         {
  74             len += 2;
  75             continue;
  76         }
  77         if (!(val = get_surrogate_value( src, srclen )))
  78         {
  79             if (flags & WC_ERR_INVALID_CHARS) return -2;
  80             continue;
  81         }
  82         if (val < 0x10000)  /* 0x800-0xffff: 3 bytes */
  83             len += 3;
  84         else   /* 0x10000-0x10ffff: 4 bytes */
  85             len += 4;
  86     }
  87     return len;
  88 }
  89
  90 /* wide char to UTF-8 string conversion */
  91 /* return -1 on dst buffer overflow, -2 on invalid input char */
  92 int wine_utf8_wcstombs( int flags, const WCHAR *src, int srclen, char *dst, int dstlen )
  93 {
  94     int len;
  95
  96     if (!dstlen) return get_length_wcs_utf8( flags, src, srclen );
  97
  98     for (len = dstlen; srclen; srclen--, src++)
  99     {
 100         WCHAR ch = *src;
 101         unsigned int val;
 102
 103         if (ch < 0x80)  /* 0x00-0x7f: 1 byte */
 104         {
 105             if (!len--) return -1;  /* overflow */
 106             *dst++ = ch;
 107             continue;
 108         }
 109
 110         if (ch < 0x800)  /* 0x80-0x7ff: 2 bytes */
 111         {
 112             if ((len -= 2) < 0) return -1;  /* overflow */
 113             dst[1] = 0x80 | (ch & 0x3f);
 114             ch >>= 6;
 115             dst[0] = 0xc0 | ch;
 116             dst += 2;
 117             continue;
 118         }
 119
 120         if (!(val = get_surrogate_value( src, srclen )))
 121         {
 122             if (flags & WC_ERR_INVALID_CHARS) return -2;
 123             continue;
 124         }
 125
 126         if (val < 0x10000)  /* 0x800-0xffff: 3 bytes */
 127         {
 128             if ((len -= 3) < 0) return -1;  /* overflow */
 129             dst[2] = 0x80 | (val & 0x3f);
 130             val >>= 6;
 131             dst[1] = 0x80 | (val & 0x3f);
 132             val >>= 6;
 133             dst[0] = 0xe0 | val;
 134             dst += 3;
 135         }
 136         else   /* 0x10000-0x10ffff: 4 bytes */
 137         {
 138             if ((len -= 4) < 0) return -1;  /* overflow */
 139             dst[3] = 0x80 | (val & 0x3f);
 140             val >>= 6;
 141             dst[2] = 0x80 | (val & 0x3f);
 142             val >>= 6;
 143             dst[1] = 0x80 | (val & 0x3f);
 144             val >>= 6;
 145             dst[0] = 0xf0 | val;
 146             dst += 4;
 147         }
 148     }
 149     return dstlen - len;
 150 }
 151
 152 /* query necessary dst length for src string */
 153 static inline int get_length_mbs_utf8( int flags, const char *src, int srclen )
 154 {
 155     int len, ret = 0;
 156     unsigned int res;
 157     const char *srcend = src + srclen;
 158
 159     while (src < srcend)
 160     {
 161         unsigned char ch = *src++;
 162         if (ch < 0x80)  /* special fast case for 7-bit ASCII */
 163         {
 164             ret++;
 165             continue;
 166         }
 167         len = utf8_length[ch-0x80];
 168         if (src + len > srcend) goto bad;
 169         res = ch & utf8_mask[len];
 170
 171         switch(len)
 172         {
 173         case 3:
 174             if ((ch = *src ^ 0x80) >= 0x40) goto bad;
 175             res = (res << 6) | ch;
 176             src++;
 177         case 2:
 178             if ((ch = *src ^ 0x80) >= 0x40) goto bad;
 179             res = (res << 6) | ch;
 180             src++;
 181         case 1:
 182             if ((ch = *src ^ 0x80) >= 0x40) goto bad;
 183             res = (res << 6) | ch;
 184             src++;
 185             if (res < utf8_minval[len]) goto bad;
 186             if (res > 0x10ffff) goto bad;
 187             if (res > 0xffff) ret++;
 188             ret++;
 189             continue;
 190         }
 191     bad:
 192         if (flags & MB_ERR_INVALID_CHARS) return -2;  /* bad char */
 193         /* otherwise ignore it */
 194     }
 195     return ret;
 196 }
 197
 198 /* UTF-8 to wide char string conversion */
 199 /* return -1 on dst buffer overflow, -2 on invalid input char */
 200 int wine_utf8_mbstowcs( int flags, const char *src, int srclen, WCHAR *dst, int dstlen )
 201 {
 202     int len;
 203     unsigned int res;
 204     const char *srcend = src + srclen;
 205     WCHAR *dstend = dst + dstlen;
 206
 207     if (!dstlen) return get_length_mbs_utf8( flags, src, srclen );
 208
 209     while ((dst < dstend) && (src < srcend))
 210     {
 211         unsigned char ch = *src++;
 212         if (ch < 0x80)  /* special fast case for 7-bit ASCII */
 213         {
 214             *dst++ = ch;
 215             continue;
 216         }
 217         len = utf8_length[ch-0x80];
 218         if (src + len > srcend) goto bad;
 219         res = ch & utf8_mask[len];
 220
 221         switch(len)
 222         {
 223         case 3:
 224             if ((ch = *src ^ 0x80) >= 0x40) goto bad;
 225             res = (res << 6) | ch;
 226             src++;
 227         case 2:
 228             if ((ch = *src ^ 0x80) >= 0x40) goto bad;
 229             res = (res << 6) | ch;
 230             src++;
 231         case 1:
 232             if ((ch = *src ^ 0x80) >= 0x40) goto bad;
 233             res = (res << 6) | ch;
 234             src++;
 235             if (res < utf8_minval[len]) goto bad;
 236             if (res > 0x10ffff) goto bad;
 237             if (res <= 0xffff) *dst++ = res;
 238             else /* we need surrogates */
 239             {
 240                 if (dst == dstend - 1) return -1;  /* overflow */
 241                 res -= 0x10000;
 242                 *dst++ = 0xd800 | (res >> 10);
 243                 *dst++ = 0xdc00 | (res & 0x3ff);
 244             }
 245             continue;
 246         }
 247     bad:
 248         if (flags & MB_ERR_INVALID_CHARS) return -2;  /* bad char */
 249         /* otherwise ignore it */
 250     }
 251     if (src < srcend) return -1;  /* overflow */
 252     return dstlen - (dstend - dst);
 253 }