libs/wine/wctomb.c

   1 /*
   2  * WideCharToMultiByte implementation
   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 extern WCHAR wine_compose( const WCHAR *str );
  26
  27 /****************************************************************/
  28 /* sbcs support */
  29
  30 /* check if 'ch' is an acceptable sbcs mapping for 'wch' */
  31 static inline int is_valid_sbcs_mapping( const struct sbcs_table *table, int flags,
  32                                          WCHAR wch, unsigned char ch )
  33 {
  34     if ((flags & WC_NO_BEST_FIT_CHARS) || ch == (unsigned char)table->info.def_char)
  35         return (table->cp2uni[ch] == wch);
  36     return 1;
  37 }
  38
  39 /* query necessary dst length for src string */
  40 static int get_length_sbcs( const struct sbcs_table *table, int flags,
  41                             const WCHAR *src, unsigned int srclen, int *used )
  42 {
  43     const unsigned char  * const uni2cp_low = table->uni2cp_low;
  44     const unsigned short * const uni2cp_high = table->uni2cp_high;
  45     int ret, tmp;
  46     WCHAR composed;
  47
  48     if (!used) used = &tmp;  /* avoid checking on every char */
  49     *used = 0;
  50
  51     for (ret = 0; srclen; ret++, src++, srclen--)
  52     {
  53         WCHAR wch = *src;
  54         unsigned char ch;
  55
  56         if ((flags & WC_COMPOSITECHECK) && (srclen > 1) && (composed = wine_compose(src)))
  57         {
  58             /* now check if we can use the composed char */
  59             ch = uni2cp_low[uni2cp_high[composed >> 8] + (composed & 0xff)];
  60             if (is_valid_sbcs_mapping( table, flags, composed, ch ))
  61             {
  62                 /* we have a good mapping, use it */
  63                 src++;
  64                 srclen--;
  65                 continue;
  66             }
  67             /* no mapping for the composed char, check the other flags */
  68             if (flags & WC_DEFAULTCHAR) /* use the default char instead */
  69             {
  70                 *used = 1;
  71                 src++;  /* skip the non-spacing char */
  72                 srclen--;
  73                 continue;
  74             }
  75             if (flags & WC_DISCARDNS) /* skip the second char of the composition */
  76             {
  77                 src++;
  78                 srclen--;
  79             }
  80             /* WC_SEPCHARS is the default */
  81         }
  82         if (!*used)
  83         {
  84             ch = uni2cp_low[uni2cp_high[wch >> 8] + (wch & 0xff)];
  85             *used = !is_valid_sbcs_mapping( table, flags, wch, ch );
  86         }
  87     }
  88     return ret;
  89 }
  90
  91 /* wcstombs for single-byte code page */
  92 static inline int wcstombs_sbcs( const struct sbcs_table *table,
  93                                  const WCHAR *src, unsigned int srclen,
  94                                  char *dst, unsigned int dstlen )
  95 {
  96     const unsigned char  * const uni2cp_low = table->uni2cp_low;
  97     const unsigned short * const uni2cp_high = table->uni2cp_high;
  98     int ret = srclen;
  99
 100     if (dstlen < srclen)
 101     {
 102         /* buffer too small: fill it up to dstlen and return error */
 103         srclen = dstlen;
 104         ret = -1;
 105     }
 106
 107     while (srclen >= 16)
 108     {
 109         dst[0]  = uni2cp_low[uni2cp_high[src[0]  >> 8] + (src[0]  & 0xff)];
 110         dst[1]  = uni2cp_low[uni2cp_high[src[1]  >> 8] + (src[1]  & 0xff)];
 111         dst[2]  = uni2cp_low[uni2cp_high[src[2]  >> 8] + (src[2]  & 0xff)];
 112         dst[3]  = uni2cp_low[uni2cp_high[src[3]  >> 8] + (src[3]  & 0xff)];
 113         dst[4]  = uni2cp_low[uni2cp_high[src[4]  >> 8] + (src[4]  & 0xff)];
 114         dst[5]  = uni2cp_low[uni2cp_high[src[5]  >> 8] + (src[5]  & 0xff)];
 115         dst[6]  = uni2cp_low[uni2cp_high[src[6]  >> 8] + (src[6]  & 0xff)];
 116         dst[7]  = uni2cp_low[uni2cp_high[src[7]  >> 8] + (src[7]  & 0xff)];
 117         dst[8]  = uni2cp_low[uni2cp_high[src[8]  >> 8] + (src[8]  & 0xff)];
 118         dst[9]  = uni2cp_low[uni2cp_high[src[9]  >> 8] + (src[9]  & 0xff)];
 119         dst[10] = uni2cp_low[uni2cp_high[src[10] >> 8] + (src[10] & 0xff)];
 120         dst[11] = uni2cp_low[uni2cp_high[src[11] >> 8] + (src[11] & 0xff)];
 121         dst[12] = uni2cp_low[uni2cp_high[src[12] >> 8] + (src[12] & 0xff)];
 122         dst[13] = uni2cp_low[uni2cp_high[src[13] >> 8] + (src[13] & 0xff)];
 123         dst[14] = uni2cp_low[uni2cp_high[src[14] >> 8] + (src[14] & 0xff)];
 124         dst[15] = uni2cp_low[uni2cp_high[src[15] >> 8] + (src[15] & 0xff)];
 125         src += 16;
 126         dst += 16;
 127         srclen -= 16;
 128     }
 129
 130     /* now handle remaining characters */
 131     src += srclen;
 132     dst += srclen;
 133     switch(srclen)
 134     {
 135     case 15: dst[-15] = uni2cp_low[uni2cp_high[src[-15] >> 8] + (src[-15] & 0xff)];
 136     case 14: dst[-14] = uni2cp_low[uni2cp_high[src[-14] >> 8] + (src[-14] & 0xff)];
 137     case 13: dst[-13] = uni2cp_low[uni2cp_high[src[-13] >> 8] + (src[-13] & 0xff)];
 138     case 12: dst[-12] = uni2cp_low[uni2cp_high[src[-12] >> 8] + (src[-12] & 0xff)];
 139     case 11: dst[-11] = uni2cp_low[uni2cp_high[src[-11] >> 8] + (src[-11] & 0xff)];
 140     case 10: dst[-10] = uni2cp_low[uni2cp_high[src[-10] >> 8] + (src[-10] & 0xff)];
 141     case 9:  dst[-9]  = uni2cp_low[uni2cp_high[src[-9]  >> 8] + (src[-9]  & 0xff)];
 142     case 8:  dst[-8]  = uni2cp_low[uni2cp_high[src[-8]  >> 8] + (src[-8]  & 0xff)];
 143     case 7:  dst[-7]  = uni2cp_low[uni2cp_high[src[-7]  >> 8] + (src[-7]  & 0xff)];
 144     case 6:  dst[-6]  = uni2cp_low[uni2cp_high[src[-6]  >> 8] + (src[-6]  & 0xff)];
 145     case 5:  dst[-5]  = uni2cp_low[uni2cp_high[src[-5]  >> 8] + (src[-5]  & 0xff)];
 146     case 4:  dst[-4]  = uni2cp_low[uni2cp_high[src[-4]  >> 8] + (src[-4]  & 0xff)];
 147     case 3:  dst[-3]  = uni2cp_low[uni2cp_high[src[-3]  >> 8] + (src[-3]  & 0xff)];
 148     case 2:  dst[-2]  = uni2cp_low[uni2cp_high[src[-2]  >> 8] + (src[-2]  & 0xff)];
 149     case 1:  dst[-1]  = uni2cp_low[uni2cp_high[src[-1]  >> 8] + (src[-1]  & 0xff)];
 150     case 0: break;
 151     }
 152     return ret;
 153 }
 154
 155 /* slow version of wcstombs_sbcs that handles the various flags */
 156 static int wcstombs_sbcs_slow( const struct sbcs_table *table, int flags,
 157                                const WCHAR *src, unsigned int srclen,
 158                                char *dst, unsigned int dstlen,
 159                                const char *defchar, int *used )
 160 {
 161     const unsigned char  * const uni2cp_low = table->uni2cp_low;
 162     const unsigned short * const uni2cp_high = table->uni2cp_high;
 163     unsigned char def;
 164     unsigned int len;
 165     int tmp;
 166     WCHAR composed;
 167
 168     if (!defchar)
 169         def = table->info.def_char & 0xff;
 170     else
 171         def = *defchar;
 172
 173     if (!used) used = &tmp;  /* avoid checking on every char */
 174     *used = 0;
 175
 176     for (len = dstlen; srclen && len; dst++, len--, src++, srclen--)
 177     {
 178         WCHAR wch = *src;
 179
 180         if ((flags & WC_COMPOSITECHECK) && (srclen > 1) && (composed = wine_compose(src)))
 181         {
 182             /* now check if we can use the composed char */
 183             *dst = uni2cp_low[uni2cp_high[composed >> 8] + (composed & 0xff)];
 184             if (is_valid_sbcs_mapping( table, flags, composed, *dst ))
 185             {
 186                 /* we have a good mapping, use it */
 187                 src++;
 188                 srclen--;
 189                 continue;
 190             }
 191             /* no mapping for the composed char, check the other flags */
 192             if (flags & WC_DEFAULTCHAR) /* use the default char instead */
 193             {
 194                 *dst = def;
 195                 *used = 1;
 196                 src++;  /* skip the non-spacing char */
 197                 srclen--;
 198                 continue;
 199             }
 200             if (flags & WC_DISCARDNS) /* skip the second char of the composition */
 201             {
 202                 src++;
 203                 srclen--;
 204             }
 205             /* WC_SEPCHARS is the default */
 206         }
 207
 208         *dst = uni2cp_low[uni2cp_high[wch >> 8] + (wch & 0xff)];
 209         if (!is_valid_sbcs_mapping( table, flags, wch, *dst ))
 210         {
 211             *dst = def;
 212             *used = 1;
 213         }
 214     }
 215     if (srclen) return -1;  /* overflow */
 216     return dstlen - len;
 217 }
 218
 219
 220 /****************************************************************/
 221 /* dbcs support */
 222
 223 /* check if 'ch' is an acceptable dbcs mapping for 'wch' */
 224 static inline int is_valid_dbcs_mapping( const struct dbcs_table *table, int flags,
 225                                          WCHAR wch, unsigned short ch )
 226 {
 227     if ((flags & WC_NO_BEST_FIT_CHARS) || ch == table->info.def_char)
 228     {
 229         /* check if char maps back to the same Unicode value */
 230         if (ch & 0xff00)
 231         {
 232             unsigned char off = table->cp2uni_leadbytes[ch >> 8];
 233             return (table->cp2uni[(off << 8) + (ch & 0xff)] == wch);
 234         }
 235         return (table->cp2uni[ch & 0xff] == wch);
 236     }
 237     return 1;
 238 }
 239
 240 /* compute the default char for the dbcs case */
 241 static inline WCHAR get_defchar_dbcs( const struct dbcs_table *table, const char *defchar )
 242 {
 243     if (!defchar) return table->info.def_char;
 244     if (!defchar[1]) return (unsigned char)defchar[0];
 245     return ((unsigned char)defchar[0] << 8) | (unsigned char)defchar[1];
 246 }
 247
 248 /* query necessary dst length for src string */
 249 static int get_length_dbcs( const struct dbcs_table *table, int flags,
 250                             const WCHAR *src, unsigned int srclen,
 251                             const char *defchar, int *used )
 252 {
 253     const unsigned short * const uni2cp_low = table->uni2cp_low;
 254     const unsigned short * const uni2cp_high = table->uni2cp_high;
 255     WCHAR defchar_value, composed;
 256     int len, tmp;
 257
 258     if (!defchar && !used && !(flags & WC_COMPOSITECHECK))
 259     {
 260         for (len = 0; srclen; srclen--, src++, len++)
 261         {
 262             if (uni2cp_low[uni2cp_high[*src >> 8] + (*src & 0xff)] & 0xff00) len++;
 263         }
 264         return len;
 265     }
 266
 267     defchar_value = get_defchar_dbcs( table, defchar );
 268     if (!used) used = &tmp;  /* avoid checking on every char */
 269     *used = 0;
 270     for (len = 0; srclen; len++, srclen--, src++)
 271     {
 272         unsigned short res;
 273         WCHAR wch = *src;
 274
 275         if ((flags & WC_COMPOSITECHECK) && (srclen > 1) && (composed = wine_compose(src)))
 276         {
 277             /* now check if we can use the composed char */
 278             res = uni2cp_low[uni2cp_high[composed >> 8] + (composed & 0xff)];
 279
 280             if (is_valid_dbcs_mapping( table, flags, composed, res ))
 281             {
 282                 /* we have a good mapping for the composed char, use it */
 283                 if (res & 0xff00) len++;
 284                 src++;
 285                 srclen--;
 286                 continue;
 287             }
 288             /* no mapping for the composed char, check the other flags */
 289             if (flags & WC_DEFAULTCHAR) /* use the default char instead */
 290             {
 291                 if (defchar_value & 0xff00) len++;
 292                 *used = 1;
 293                 src++;  /* skip the non-spacing char */
 294                 srclen--;
 295                 continue;
 296             }
 297             if (flags & WC_DISCARDNS) /* skip the second char of the composition */
 298             {
 299                 src++;
 300                 srclen--;
 301             }
 302             /* WC_SEPCHARS is the default */
 303         }
 304
 305         res = uni2cp_low[uni2cp_high[wch >> 8] + (wch & 0xff)];
 306         if (!is_valid_dbcs_mapping( table, flags, wch, res ))
 307         {
 308             res = defchar_value;
 309             *used = 1;
 310         }
 311         if (res & 0xff00) len++;
 312     }
 313     return len;
 314 }
 315
 316 /* wcstombs for double-byte code page */
 317 static inline int wcstombs_dbcs( const struct dbcs_table *table,
 318                                  const WCHAR *src, unsigned int srclen,
 319                                  char *dst, unsigned int dstlen )
 320 {
 321     const unsigned short * const uni2cp_low = table->uni2cp_low;
 322     const unsigned short * const uni2cp_high = table->uni2cp_high;
 323     int len;
 324
 325     for (len = dstlen; srclen && len; len--, srclen--, src++)
 326     {
 327         unsigned short res = uni2cp_low[uni2cp_high[*src >> 8] + (*src & 0xff)];
 328         if (res & 0xff00)
 329         {
 330             if (len == 1) break;  /* do not output a partial char */
 331             len--;
 332             *dst++ = res >> 8;
 333         }
 334         *dst++ = (char)res;
 335     }
 336     if (srclen) return -1;  /* overflow */
 337     return dstlen - len;
 338 }
 339
 340 /* slow version of wcstombs_dbcs that handles the various flags */
 341 static int wcstombs_dbcs_slow( const struct dbcs_table *table, int flags,
 342                                const WCHAR *src, unsigned int srclen,
 343                                char *dst, unsigned int dstlen,
 344                                const char *defchar, int *used )
 345 {
 346     const unsigned short * const uni2cp_low = table->uni2cp_low;
 347     const unsigned short * const uni2cp_high = table->uni2cp_high;
 348     WCHAR defchar_value = get_defchar_dbcs( table, defchar );
 349     WCHAR composed;
 350     int len, tmp;
 351
 352     if (!used) used = &tmp;  /* avoid checking on every char */
 353     *used = 0;
 354
 355     for (len = dstlen; srclen && len; len--, srclen--, src++)
 356     {
 357         unsigned short res;
 358         WCHAR wch = *src;
 359
 360         if ((flags & WC_COMPOSITECHECK) && (srclen > 1) && (composed = wine_compose(src)))
 361         {
 362             /* now check if we can use the composed char */
 363             res = uni2cp_low[uni2cp_high[composed >> 8] + (composed & 0xff)];
 364
 365             if (is_valid_dbcs_mapping( table, flags, composed, res ))
 366             {
 367                 /* we have a good mapping for the composed char, use it */
 368                 src++;
 369                 srclen--;
 370                 goto output_char;
 371             }
 372             /* no mapping for the composed char, check the other flags */
 373             if (flags & WC_DEFAULTCHAR) /* use the default char instead */
 374             {
 375                 res = defchar_value;
 376                 *used = 1;
 377                 src++;  /* skip the non-spacing char */
 378                 srclen--;
 379                 goto output_char;
 380             }
 381             if (flags & WC_DISCARDNS) /* skip the second char of the composition */
 382             {
 383                 src++;
 384                 srclen--;
 385             }
 386             /* WC_SEPCHARS is the default */
 387         }
 388
 389         res = uni2cp_low[uni2cp_high[wch >> 8] + (wch & 0xff)];
 390         if (!is_valid_dbcs_mapping( table, flags, wch, res ))
 391         {
 392             res = defchar_value;
 393             *used = 1;
 394         }
 395
 396     output_char:
 397         if (res & 0xff00)
 398         {
 399             if (len == 1) break;  /* do not output a partial char */
 400             len--;
 401             *dst++ = res >> 8;
 402         }
 403         *dst++ = (char)res;
 404     }
 405     if (srclen) return -1;  /* overflow */
 406     return dstlen - len;
 407 }
 408
 409 /* wide char to multi byte string conversion */
 410 /* return -1 on dst buffer overflow */
 411 int wine_cp_wcstombs( const union cptable *table, int flags,
 412                       const WCHAR *src, int srclen,
 413                       char *dst, int dstlen, const char *defchar, int *used )
 414 {
 415     if (table->info.char_size == 1)
 416     {
 417         if (flags || defchar || used)
 418         {
 419             if (!dstlen) return get_length_sbcs( &table->sbcs, flags, src, srclen, used );
 420             return wcstombs_sbcs_slow( &table->sbcs, flags, src, srclen,
 421                                        dst, dstlen, defchar, used );
 422         }
 423         if (!dstlen) return srclen;
 424         return wcstombs_sbcs( &table->sbcs, src, srclen, dst, dstlen );
 425     }
 426     else /* mbcs */
 427     {
 428         if (!dstlen) return get_length_dbcs( &table->dbcs, flags, src, srclen, defchar, used );
 429         if (flags || defchar || used)
 430             return wcstombs_dbcs_slow( &table->dbcs, flags, src, srclen,
 431                                        dst, dstlen, defchar, used );
 432         return wcstombs_dbcs( &table->dbcs, src, srclen, dst, dstlen );
 433     }
 434 }