1 /* 2 tre_regexec.c - TRE POSIX compatible matching functions (and more). 3 4 This software is released under a BSD-style license. 5 See the file LICENSE for details and copyright. 6 7 */ 8 9 #ifdef HAVE_CONFIG_H 10 #include <config.h> 11 #endif /* HAVE_CONFIG_H */ 12 13 #ifdef TRE_USE_ALLOCA 14 /* AIX requires this to be the first thing in the file. */ 15 #ifndef __GNUC__ 16 # if HAVE_ALLOCA_H 17 # include <alloca.h> 18 # else 19 # ifdef _AIX 20 #pragma alloca 21 # else 22 # ifndef alloca /* predefined by HP cc +Olibcalls */ 23 char *alloca (); 24 # endif 25 # endif 26 # endif 27 #endif 28 #endif /* TRE_USE_ALLOCA */ 29 30 #include <assert.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #ifdef HAVE_WCHAR_H 34 #include <wchar.h> 35 #endif /* HAVE_WCHAR_H */ 36 #ifdef HAVE_WCTYPE_H 37 #include <wctype.h> 38 #endif /* HAVE_WCTYPE_H */ 39 #ifndef TRE_WCHAR 40 #include <ctype.h> 41 #endif /* !TRE_WCHAR */ 42 #ifdef HAVE_MALLOC_H 43 #include <malloc.h> 44 #endif /* HAVE_MALLOC_H */ 45 #include <limits.h> 46 47 #include "tre-internal.h" 48 #include "tre-match-utils.h" 49 #include "tre.h" 50 #include "xmalloc.h" 51 52 53 /* For each tre_last_matched_t in the lm array, find the last matched branch by 54 comparing the touch value of the cmp_tag's. For all other branches, reset 55 the corresponding tags. If reset_all is non-zero, reset all tags in all 56 branches. Recurse into the nested last matched structures, clearing tags as 57 apprpriate. */ 58 static void 59 tre_reset_last_matched_branches(tre_tag_t *tags, const tre_last_matched_t *lm, 60 int n, int start_tag, int reset_all) 61 { 62 int max, i, reset; 63 tre_last_matched_branch_t *b; 64 65 DPRINT(("tre_reset_last_matched_branches: n=%d start_tag=%d reset_all=%d\n", 66 n, start_tag, reset_all)); 67 for (; n-- > 0; lm++) 68 { 69 if (lm->n_branches == 1) 70 { 71 b = lm->branches; 72 if (start_tag > 0) 73 { 74 DPRINT((" b->cmp_tag=%d %d <? %d\n", b->cmp_tag, 75 tre_tag_touch_get(tags, b->cmp_tag), 76 tre_tag_touch_get(tags, start_tag))); 77 reset = (reset_all || tre_tag_touch_get(tags, b->cmp_tag) < 78 tre_tag_touch_get(tags, start_tag)); 79 } 80 else 81 reset = 0; 82 83 if (reset) 84 { 85 int *t; 86 87 for (i = b->n_tags, t = b->tags; i > 0; i--, t++) 88 { 89 DPRINT((" Resetting t%d\n", *t)); 90 tre_tag_reset(tags, *t); 91 } 92 } 93 if (b->n_last_matched > 0) 94 tre_reset_last_matched_branches(tags, b->last_matched, 95 b->n_last_matched, 96 lm->start_tag, reset); 97 } 98 else 99 { 100 if (!reset_all) 101 { 102 #ifdef TRE_DEBUG 103 int last; 104 #endif /* TRE_DEBUG */ 105 max = 0; 106 for (i = lm->n_branches, b = lm->branches; i > 0; i--, b++) 107 { 108 int t = b->cmp_tag; 109 int touch = tre_tag_touch_get(tags, t); 110 if (touch > max) 111 { 112 max = touch; 113 #ifdef TRE_DEBUG 114 last = t; 115 #endif /* TRE_DEBUG */ 116 } 117 } 118 DPRINT((" Last touched end tag t%d=%d\n", last, max)); 119 } 120 121 for (i = lm->n_branches, b = lm->branches; i > 0; i--, b++) 122 { 123 reset = (reset_all || tre_tag_touch_get(tags, b->cmp_tag) < max); 124 if (reset) 125 { 126 int j; 127 int *t; 128 129 for (j = b->n_tags, t = b->tags; j > 0; j--, t++) 130 { 131 DPRINT((" Resetting t%d\n", *t)); 132 tre_tag_reset(tags, *t); 133 } 134 } 135 if (b->n_last_matched > 0) 136 tre_reset_last_matched_branches(tags, b->last_matched, 137 b->n_last_matched, 138 lm->start_tag, reset); 139 } 140 } 141 } 142 } 143 144 145 /* Fills the POSIX.2 regmatch_t array according to the TNFA tag and match 146 endpoint values. */ 147 reg_errcode_t 148 tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags, 149 const tre_tnfa_t *tnfa, const tre_tag_t *intags, int match_eo) 150 { 151 unsigned int i; 152 153 if (cflags & REG_NOSUB) return REG_OK; 154 155 i = 0; 156 if (match_eo >= 0 && intags) 157 { 158 const tre_tag_t *tags = intags; 159 tre_submatch_data_t *submatch_data; 160 161 if (tnfa->last_matched_branch && 162 tnfa->last_matched_branch->n_last_matched > 0) 163 { 164 tre_tag_t *t; 165 #ifdef TRE_USE_ALLOCA 166 t = alloca(sizeof(*t) * tnfa->num_tags); 167 #else /* !TRE_USE_ALLOCA */ 168 t = xmalloc(sizeof(*t) * tnfa->num_tags); 169 #endif /* !TRE_USE_ALLOCA */ 170 if (!t) return REG_ESPACE; 171 memcpy(t, intags, tnfa->num_tags * sizeof(tre_tag_t)); 172 tre_reset_last_matched_branches(t, 173 tnfa->last_matched_branch->last_matched, 174 tnfa->last_matched_branch->n_last_matched, 175 0, 0); 176 tags = t; 177 } 178 /* Construct submatch offsets from the tags. */ 179 DPRINT(("end tag = t%d = %d\n", tnfa->end_tag, match_eo)); 180 submatch_data = tnfa->submatch_data; 181 while (i < tnfa->num_submatches && i < nmatch) 182 { 183 if (submatch_data[i].so_tag == tnfa->end_tag) 184 pmatch[i].rm_so = match_eo; 185 else 186 pmatch[i].rm_so = tre_tag_get(tags, submatch_data[i].so_tag); 187 188 if (submatch_data[i].eo_tag == tnfa->end_tag) 189 pmatch[i].rm_eo = match_eo; 190 else 191 pmatch[i].rm_eo = tre_tag_get(tags, submatch_data[i].eo_tag); 192 193 /* If either of the endpoints were not used, this submatch 194 was not part of the match. */ 195 if (pmatch[i].rm_so == -1 || pmatch[i].rm_eo == -1) 196 pmatch[i].rm_so = pmatch[i].rm_eo = -1; 197 198 DPRINT(("pmatch[%d] = {t%d = %qd, t%d = %qd}\n", i, 199 submatch_data[i].so_tag, pmatch[i].rm_so, 200 submatch_data[i].eo_tag, pmatch[i].rm_eo)); 201 i++; 202 } 203 #ifndef TRE_USE_ALLOCA 204 #pragma GCC diagnostic push 205 #pragma GCC diagnostic ignored "-Wdiscarded-qualifiers" 206 if (tags != intags) xfree(tags); 207 #pragma GCC diagnostic pop 208 #endif /* !TRE_USE_ALLOCA */ 209 } 210 211 while (i < nmatch) 212 { 213 pmatch[i].rm_so = -1; 214 pmatch[i].rm_eo = -1; 215 i++; 216 } 217 218 return REG_OK; 219 } 220 221 222 /* 223 Wrapper functions for POSIX compatible regexp matching. 224 */ 225 226 int 227 tre_have_backrefs(const regex_t *preg) 228 { 229 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD; 230 return tnfa->have_backrefs; 231 } 232 233 #ifdef TRE_APPROX 234 int 235 tre_have_approx(const regex_t *preg) 236 { 237 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD; 238 return tnfa->have_approx; 239 } 240 #endif /* TRE_APPROX */ 241 242 static int 243 tre_match(const tre_tnfa_t *tnfa, const void *string, size_t len, 244 tre_str_type_t type, size_t nmatch, regmatch_t pmatch[], 245 int eflags) 246 { 247 reg_errcode_t status; 248 tre_tag_t *tags = NULL; 249 int eo; 250 size_t offset = 0, count = 0; 251 if (tnfa->num_tags > 0 && nmatch > 0) 252 { 253 #ifdef TRE_USE_ALLOCA 254 tags = alloca(sizeof(*tags) * tnfa->num_tags); 255 #else /* !TRE_USE_ALLOCA */ 256 tags = xmalloc(sizeof(*tags) * tnfa->num_tags); 257 #endif /* !TRE_USE_ALLOCA */ 258 if (tags == NULL) 259 return REG_ESPACE; 260 } 261 262 if ( 263 (eflags & REG_STARTEND) && pmatch) 264 { 265 if (pmatch->rm_so < 0) 266 return REG_INVARG; 267 if (len == (size_t)-1) 268 { 269 if (pmatch->rm_eo < 0 || pmatch->rm_so > pmatch->rm_eo) 270 return REG_INVARG; 271 len = pmatch->rm_eo - pmatch->rm_so; 272 } 273 count = offset = pmatch->rm_so; 274 if (type == STR_WIDE) offset *= sizeof(wchar_t); 275 } 276 277 /* Dispatch to the appropriate matcher. */ 278 if (tnfa->have_backrefs || eflags & REG_BACKTRACKING_MATCHER) 279 { 280 /* The regex has back references, use the backtracking matcher. */ 281 status = tre_tnfa_run_backtrack(tnfa, string + offset, (int)len, type, 282 tags, eflags, &eo); 283 } 284 #ifdef TRE_APPROX 285 else if (tnfa->have_approx || eflags & REG_APPROX_MATCHER) 286 { 287 /* The regex uses approximate matching, use the approximate matcher. */ 288 regamatch_t match; 289 regaparams_t params; 290 tre_regaparams_default(¶ms); 291 params.max_err = 0; 292 params.max_cost = 0; 293 status = tre_tnfa_run_approx(tnfa, string + offset, (int)len, type, tags, 294 &match, params, eflags, &eo); 295 } 296 #endif /* TRE_APPROX */ 297 else 298 { 299 /* Exact matching, no back references, use the parallel matcher. */ 300 status = tre_tnfa_run_parallel(tnfa, string + offset, (int)len, type, 301 tags, eflags, &eo); 302 } 303 304 if (status == REG_OK) 305 { 306 /* A match was found, so fill the submatch registers. */ 307 status = tre_fill_pmatch(nmatch, pmatch, tnfa->cflags, tnfa, tags, eo); 308 /* If doing REG_STARTEND, adjust the pmatch array (we can't build 309 this into tre_fill_pmatch, because tre_tnfa_run_backtrack calls 310 tre_fill_pmatch itself). */ 311 if (status == REG_OK && !(tnfa->cflags & REG_NOSUB) && 312 (eflags & REG_STARTEND) && pmatch && nmatch > 0) 313 { 314 size_t i; 315 regmatch_t *p; 316 for (i = nmatch, p = pmatch; i > 0; p++, i--) 317 { 318 if (p->rm_so >= 0) p->rm_so += count; 319 if (p->rm_eo >= 0) p->rm_eo += count; 320 } 321 } 322 } 323 #ifndef TRE_USE_ALLOCA 324 if (tags) 325 xfree(tags); 326 #endif /* !TRE_USE_ALLOCA */ 327 return status; 328 } 329 330 int 331 tre_regnexec(const regex_t *preg, const char *str, size_t len, 332 size_t nmatch, regmatch_t pmatch[], int eflags) 333 { 334 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD; 335 tre_str_type_t type = (TRE_MB_CUR_MAX_L(tnfa->loc) == 1) ? STR_BYTE : STR_MBS; 336 337 #ifdef TRE_USE_SYSTEM_REGEX_H 338 if (preg->re_magic != RE_MAGIC) return REG_BADPAT; 339 #endif /* TRE_USE_SYSTEM_REGEX_H */ 340 341 return tre_match(tnfa, str, len, type, nmatch, pmatch, eflags); 342 } 343 344 int 345 tre_regexec(const regex_t *preg, const char *str, 346 size_t nmatch, regmatch_t pmatch[], int eflags) 347 { 348 return tre_regnexec(preg, str, (size_t)-1, nmatch, pmatch, eflags); 349 } 350 351 352 #ifdef TRE_WCHAR 353 354 int 355 tre_regwnexec(const regex_t *preg, const wchar_t *str, size_t len, 356 size_t nmatch, regmatch_t pmatch[], int eflags) 357 { 358 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD; 359 360 #ifdef TRE_USE_SYSTEM_REGEX_H 361 if (preg->re_magic != RE_MAGIC) return REG_BADPAT; 362 #endif /* TRE_USE_SYSTEM_REGEX_H */ 363 364 return tre_match(tnfa, str, len, STR_WIDE, nmatch, pmatch, eflags); 365 } 366 367 int 368 tre_regwexec(const regex_t *preg, const wchar_t *str, 369 size_t nmatch, regmatch_t pmatch[], int eflags) 370 { 371 return tre_regwnexec(preg, str, (size_t)-1, nmatch, pmatch, eflags); 372 } 373 374 #endif /* TRE_WCHAR */ 375 376 #ifdef TRE_APPROX 377 378 /* 379 Wrapper functions for approximate regexp matching. 380 */ 381 382 static int 383 tre_match_approx(const tre_tnfa_t *tnfa, const void *string, size_t len, 384 tre_str_type_t type, regamatch_t *match, regaparams_t params, 385 int eflags) 386 { 387 reg_errcode_t status; 388 tre_tag_t *tags = NULL; 389 int eo; 390 size_t offset = 0, count = 0; 391 392 /* If the regexp does not use approximate matching features, the 393 maximum cost is zero, and the approximate matcher isn't forced, 394 use the exact matcher instead. */ 395 if (params.max_cost == 0 && !tnfa->have_approx 396 && !(eflags & REG_APPROX_MATCHER)) 397 return tre_match(tnfa, string, len, type, match->nmatch, match->pmatch, 398 eflags); 399 400 /* Back references are not supported by the approximate matcher. */ 401 if (tnfa->have_backrefs) 402 return REG_BADPAT; 403 404 if (tnfa->num_tags > 0 && match->nmatch > 0) 405 { 406 #if TRE_USE_ALLOCA 407 tags = alloca(sizeof(*tags) * tnfa->num_tags); 408 #else /* !TRE_USE_ALLOCA */ 409 tags = xmalloc(sizeof(*tags) * tnfa->num_tags); 410 #endif /* !TRE_USE_ALLOCA */ 411 if (tags == NULL) 412 return REG_ESPACE; 413 } 414 415 if ( 416 (eflags & REG_STARTEND) && match->pmatch) 417 { 418 if (match->pmatch->rm_so < 0) 419 return REG_INVARG; 420 if (len == (size_t)-1) 421 { 422 if (match->pmatch->rm_eo < 0 || match->pmatch->rm_so > 423 match->pmatch->rm_eo) 424 return REG_INVARG; 425 len = match->pmatch->rm_eo - match->pmatch->rm_so; 426 } 427 count = offset = match->pmatch->rm_so; 428 if (type == STR_WIDE) offset *= sizeof(wchar_t); 429 } 430 431 status = tre_tnfa_run_approx(tnfa, string, (int)len, type, tags, 432 match, params, eflags, &eo); 433 if (status == REG_OK) 434 { 435 status = tre_fill_pmatch(match->nmatch, match->pmatch, tnfa->cflags, 436 tnfa, tags, eo); 437 /* If doing REG_STARTEND, adjust the pmatch array (we can't build 438 this into tre_fill_pmatch, because tre_tnfa_run_backtrack call 439 tre_fill_pmatch itself). */ 440 if (status == REG_OK && !(tnfa->cflags & REG_NOSUB) && 441 (eflags & REG_STARTEND) && match->pmatch && match->nmatch > 0) 442 { 443 size_t i; 444 regmatch_t *p; 445 for (i = match->nmatch, p = match->pmatch; i > 0; p++, i--) 446 { 447 if (p->rm_so >= 0) p->rm_so += count; 448 if (p->rm_eo >= 0) p->rm_eo += count; 449 } 450 } 451 } 452 #ifndef TRE_USE_ALLOCA 453 if (tags) 454 xfree(tags); 455 #endif /* !TRE_USE_ALLOCA */ 456 return status; 457 } 458 459 int 460 tre_reganexec(const regex_t *preg, const char *str, size_t len, 461 regamatch_t *match, regaparams_t params, int eflags) 462 { 463 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD; 464 tre_str_type_t type = (TRE_MB_CUR_MAX_L(tnfa->loc) == 1) ? STR_BYTE : STR_MBS; 465 466 #ifdef TRE_USE_SYSTEM_REGEX_H 467 if (preg->re_magic != RE_MAGIC) return REG_BADPAT; 468 #endif /* TRE_USE_SYSTEM_REGEX_H */ 469 470 return tre_match_approx(tnfa, str, len, type, match, params, eflags); 471 } 472 473 int 474 tre_regaexec(const regex_t *preg, const char *str, 475 regamatch_t *match, regaparams_t params, int eflags) 476 { 477 return tre_reganexec(preg, str, (size_t)-1, match, params, eflags); 478 } 479 480 #ifdef TRE_WCHAR 481 482 int 483 tre_regawnexec(const regex_t *preg, const wchar_t *str, size_t len, 484 regamatch_t *match, regaparams_t params, int eflags) 485 { 486 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD; 487 488 #ifdef TRE_USE_SYSTEM_REGEX_H 489 if (preg->re_magic != RE_MAGIC) return REG_BADPAT; 490 #endif /* TRE_USE_SYSTEM_REGEX_H */ 491 492 return tre_match_approx(tnfa, str, len, STR_WIDE, 493 match, params, eflags); 494 } 495 496 int 497 tre_regawexec(const regex_t *preg, const wchar_t *str, 498 regamatch_t *match, regaparams_t params, int eflags) 499 { 500 return tre_regawnexec(preg, str, (size_t)-1, match, params, eflags); 501 } 502 503 #endif /* TRE_WCHAR */ 504 505 void 506 tre_regaparams_default(regaparams_t *params) 507 { 508 memset(params, 0, sizeof(*params)); 509 params->cost_ins = 1; 510 params->cost_del = 1; 511 params->cost_subst = 1; 512 params->max_cost = INT_MAX; 513 params->max_ins = INT_MAX; 514 params->max_del = INT_MAX; 515 params->max_subst = INT_MAX; 516 params->max_err = INT_MAX; 517 } 518 519 #endif /* TRE_APPROX */ 520 521 /* EOF */ 522