lib/unicase/u-casemap.h

   1 /* Case mapping for UTF-8/UTF-16/UTF-32 strings (locale dependent).
   2    Copyright (C) 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2009.
   4
   5    This program is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Lesser General Public License as published
   7    by the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 UNIT *
  19 FUNC (const UNIT *s, size_t n,
  20       casing_prefix_context_t prefix_context,
  21       casing_suffix_context_t suffix_context,
  22       const char *iso639_language,
  23       ucs4_t (*single_character_map) (ucs4_t),
  24       size_t offset_in_rule, /* offset in 'struct special_casing_rule' */
  25       uninorm_t nf,
  26       UNIT *resultbuf, size_t *lengthp)
  27 {
  28   /* The result being accumulated.  */
  29   UNIT *result;
  30   size_t length;
  31   size_t allocated;
  32
  33   /* Initialize the accumulator.  */
  34   if (nf != NULL || resultbuf == NULL)
  35     {
  36       result = NULL;
  37       allocated = 0;
  38     }
  39   else
  40     {
  41       result = resultbuf;
  42       allocated = *lengthp;
  43     }
  44   length = 0;
  45
  46   {
  47     const UNIT *s_end = s + n;
  48
  49     /* Helper for evaluating the FINAL_SIGMA condition:
  50        Last character that was not case-ignorable.  */
  51     ucs4_t last_char_except_ignorable =
  52       prefix_context.last_char_except_ignorable;
  53
  54     /* Helper for evaluating the AFTER_SOFT_DOTTED and AFTER_I conditions:
  55        Last character that was of combining class 230 ("Above") or 0.  */
  56     ucs4_t last_char_normal_or_above =
  57       prefix_context.last_char_normal_or_above;
  58
  59     while (s < s_end)
  60       {
  61         ucs4_t uc;
  62         int count = U_MBTOUC_UNSAFE (&uc, s, s_end - s);
  63
  64         ucs4_t mapped_uc[3];
  65         unsigned int mapped_count;
  66
  67         if (uc < 0x10000)
  68           {
  69             /* Look first in the special-casing table.  */
  70             char code[3];
  71
  72             code[0] = (uc >> 8) & 0xff;
  73             code[1] = uc & 0xff;
  74
  75             for (code[2] = 0; ; code[2]++)
  76               {
  77                 const struct special_casing_rule *rule =
  78                   gl_unicase_special_lookup (code, 3);
  79
  80                 if (rule == NULL)
  81                   break;
  82
  83                 /* Test if the condition applies.  */
  84                 /* Does the language apply?  */
  85                 if (rule->language[0] == '\0'
  86                     || (iso639_language != NULL
  87                         && iso639_language[0] == rule->language[0]
  88                         && iso639_language[1] == rule->language[1]))
  89                   {
  90                     /* Does the context apply?  */
  91                     int context = rule->context;
  92                     bool applies;
  93
  94                     if (context < 0)
  95                       context = - context;
  96                     switch (context)
  97                       {
  98                       case SCC_ALWAYS:
  99                         applies = true;
 100                         break;
 101
 102                       case SCC_FINAL_SIGMA:
 103                         /* "Before" condition: preceded by a sequence
 104                            consisting of a cased letter and a case-ignorable
 105                            sequence.
 106                            "After" condition: not followed by a sequence
 107                            consisting of a case-ignorable sequence and then a
 108                            cased letter.  */
 109                         /* Test the "before" condition.  */
 110                         applies = uc_is_cased (last_char_except_ignorable);
 111                         /* Test the "after" condition.  */
 112                         if (applies)
 113                           {
 114                             const UNIT *s2 = s + count;
 115                             for (;;)
 116                               {
 117                                 if (s2 < s_end)
 118                                   {
 119                                     ucs4_t uc2;
 120                                     int count2 = U_MBTOUC_UNSAFE (&uc2, s2, s_end - s2);
 121                                     /* Our uc_is_case_ignorable function is
 122                                        known to return false for all cased
 123                                        characters.  So we can call
 124                                        uc_is_case_ignorable first.  */
 125                                     if (!uc_is_case_ignorable (uc2))
 126                                       {
 127                                         applies = ! uc_is_cased (uc2);
 128                                         break;
 129                                       }
 130                                     s2 += count2;
 131                                   }
 132                                 else
 133                                   {
 134                                     applies = ! uc_is_cased (suffix_context.first_char_except_ignorable);
 135                                     break;
 136                                   }
 137                               }
 138                           }
 139                         break;
 140
 141                       case SCC_AFTER_SOFT_DOTTED:
 142                         /* "Before" condition: There is a Soft_Dotted character
 143                            before it, with no intervening character of
 144                            combining class 0 or 230 (Above).  */
 145                         /* Test the "before" condition.  */
 146                         applies = uc_is_property_soft_dotted (last_char_normal_or_above);
 147                         break;
 148
 149                       case SCC_MORE_ABOVE:
 150                         /* "After" condition: followed by a character of
 151                            combining class 230 (Above) with no intervening
 152                            character of combining class 0 or 230 (Above).  */
 153                         /* Test the "after" condition.  */
 154                         {
 155                           const UNIT *s2 = s + count;
 156                           applies = false;
 157                           for (;;)
 158                             {
 159                               if (s2 < s_end)
 160                                 {
 161                                   ucs4_t uc2;
 162                                   int count2 = U_MBTOUC_UNSAFE (&uc2, s2, s_end - s2);
 163                                   int ccc = uc_combining_class (uc2);
 164                                   if (ccc == UC_CCC_A)
 165                                     {
 166                                       applies = true;
 167                                       break;
 168                                     }
 169                                   if (ccc == UC_CCC_NR)
 170                                     break;
 171                                   s2 += count2;
 172                                 }
 173                               else
 174                                 {
 175                                   applies = ((suffix_context.bits & SCC_MORE_ABOVE_MASK) != 0);
 176                                   break;
 177                                 }
 178                             }
 179                         }
 180                         break;
 181
 182                       case SCC_BEFORE_DOT:
 183                         /* "After" condition: followed by COMBINING DOT ABOVE
 184                            (U+0307). Any sequence of characters with a
 185                            combining class that is neither 0 nor 230 may
 186                            intervene between the current character and the
 187                            combining dot above.  */
 188                         /* Test the "after" condition.  */
 189                         {
 190                           const UNIT *s2 = s + count;
 191                           applies = false;
 192                           for (;;)
 193                             {
 194                               if (s2 < s_end)
 195                                 {
 196                                   ucs4_t uc2;
 197                                   int count2 = U_MBTOUC_UNSAFE (&uc2, s2, s_end - s2);
 198                                   if (uc2 == 0x0307) /* COMBINING DOT ABOVE */
 199                                     {
 200                                       applies = true;
 201                                       break;
 202                                     }
 203                                   {
 204                                     int ccc = uc_combining_class (uc2);
 205                                     if (ccc == UC_CCC_A || ccc == UC_CCC_NR)
 206                                       break;
 207                                   }
 208                                   s2 += count2;
 209                                 }
 210                               else
 211                                 {
 212                                   applies = ((suffix_context.bits & SCC_BEFORE_DOT_MASK) != 0);
 213                                   break;
 214                                 }
 215                             }
 216                         }
 217                         break;
 218
 219                       case SCC_AFTER_I:
 220                         /* "Before" condition: There is an uppercase I before
 221                            it, and there is no intervening character of
 222                            combining class 0 or 230 (Above).  */
 223                         /* Test the "before" condition.  */
 224                         applies = (last_char_normal_or_above == 'I');
 225                         break;
 226
 227                       default:
 228                         abort ();
 229                       }
 230                     if (rule->context < 0)
 231                       applies = !applies;
 232
 233                     if (applies)
 234                       {
 235                         /* The rule applies.
 236                            Look up the mapping (0 to 3 characters).  */
 237                         const unsigned short *mapped_in_rule =
 238                           (const unsigned short *)((const char *)rule + offset_in_rule);
 239
 240                         if (mapped_in_rule[0] == 0)
 241                           mapped_count = 0;
 242                         else
 243                           {
 244                             mapped_uc[0] = mapped_in_rule[0];
 245                             if (mapped_in_rule[1] == 0)
 246                               mapped_count = 1;
 247                             else
 248                               {
 249                                 mapped_uc[1] = mapped_in_rule[1];
 250                                 if (mapped_in_rule[2] == 0)
 251                                   mapped_count = 2;
 252                                 else
 253                                   {
 254                                     mapped_uc[2] = mapped_in_rule[2];
 255                                     mapped_count = 3;
 256                                   }
 257                               }
 258                           }
 259                         goto found_mapping;
 260                       }
 261                   }
 262
 263                 /* Optimization: Save a hash table lookup in the next round.  */
 264                 if (!rule->has_next)
 265                   break;
 266               }
 267           }
 268
 269         /* No special-cased mapping.  So use the locale and context independent
 270            mapping.  */
 271         mapped_uc[0] = single_character_map (uc);
 272         mapped_count = 1;
 273
 274        found_mapping:
 275         /* Found the mapping: uc maps to mapped_uc[0..mapped_count-1].  */
 276         {
 277           unsigned int i;
 278
 279           for (i = 0; i < mapped_count; i++)
 280             {
 281               ucs4_t muc = mapped_uc[i];
 282
 283               /* Append muc to the result accumulator.  */
 284               if (length < allocated)
 285                 {
 286                   int ret = U_UCTOMB (result + length, muc, allocated - length);
 287                   if (ret == -1)
 288                     {
 289                       errno = EINVAL;
 290                       goto fail;
 291                     }
 292                   if (ret >= 0)
 293                     {
 294                       length += ret;
 295                       goto done_appending;
 296                     }
 297                 }
 298               {
 299                 size_t old_allocated = allocated;
 300                 size_t new_allocated = 2 * old_allocated;
 301                 if (new_allocated < 64)
 302                   new_allocated = 64;
 303                 if (new_allocated < old_allocated) /* integer overflow? */
 304                   abort ();
 305                 {
 306                   UNIT *larger_result;
 307                   if (result == NULL)
 308                     {
 309                       larger_result = (UNIT *) malloc (new_allocated * sizeof (UNIT));
 310                       if (larger_result == NULL)
 311                         {
 312                           errno = ENOMEM;
 313                           goto fail;
 314                         }
 315                     }
 316                   else if (result == resultbuf)
 317                     {
 318                       larger_result = (UNIT *) malloc (new_allocated * sizeof (UNIT));
 319                       if (larger_result == NULL)
 320                         {
 321                           errno = ENOMEM;
 322                           goto fail;
 323                         }
 324                       U_CPY (larger_result, resultbuf, length);
 325                     }
 326                   else
 327                     {
 328                       larger_result =
 329                         (UNIT *) realloc (result, new_allocated * sizeof (UNIT));
 330                       if (larger_result == NULL)
 331                         {
 332                           errno = ENOMEM;
 333                           goto fail;
 334                         }
 335                     }
 336                   result = larger_result;
 337                   allocated = new_allocated;
 338                   {
 339                     int ret = U_UCTOMB (result + length, muc, allocated - length);
 340                     if (ret == -1)
 341                       {
 342                         errno = EINVAL;
 343                         goto fail;
 344                       }
 345                     if (ret < 0)
 346                       abort ();
 347                     length += ret;
 348                     goto done_appending;
 349                   }
 350                 }
 351               }
 352              done_appending: ;
 353             }
 354         }
 355
 356         if (!uc_is_case_ignorable (uc))
 357           last_char_except_ignorable = uc;
 358
 359         {
 360           int ccc = uc_combining_class (uc);
 361           if (ccc == UC_CCC_A || ccc == UC_CCC_NR)
 362             last_char_normal_or_above = uc;
 363         }
 364
 365         s += count;
 366       }
 367   }
 368
 369   if (nf != NULL)
 370     {
 371       /* Finally, normalize the result.  */
 372       UNIT *normalized_result;
 373
 374       normalized_result = U_NORMALIZE (nf, result, length, resultbuf, lengthp);
 375       if (normalized_result == NULL)
 376         goto fail;
 377
 378       free (result);
 379       return normalized_result;
 380     }
 381
 382   if (length == 0)
 383     {
 384       if (result == NULL)
 385         {
 386           /* Return a non-NULL value.  NULL means error.  */
 387           result = (UNIT *) malloc (1);
 388           if (result == NULL)
 389             {
 390               errno = ENOMEM;
 391               goto fail;
 392             }
 393         }
 394     }
 395   else if (result != resultbuf && length < allocated)
 396     {
 397       /* Shrink the allocated memory if possible.  */
 398       UNIT *memory;
 399
 400       memory = (UNIT *) realloc (result, length * sizeof (UNIT));
 401       if (memory != NULL)
 402         result = memory;
 403     }
 404
 405   *lengthp = length;
 406   return result;
 407
 408  fail:
 409   if (result != resultbuf)
 410     {
 411       int saved_errno = errno;
 412       free (result);
 413       errno = saved_errno;
 414     }
 415   return NULL;
 416 }