John Bauman | 8940182 | 2014-05-06 15:04:28 -0400 | [diff] [blame] | 1 | /*- |
| 2 | * This code is derived from OpenBSD's libc/regex, original license follows: |
| 3 | * |
| 4 | * Copyright (c) 1992, 1993, 1994 Henry Spencer. |
| 5 | * Copyright (c) 1992, 1993, 1994 |
| 6 | * The Regents of the University of California. All rights reserved. |
| 7 | * |
| 8 | * This code is derived from software contributed to Berkeley by |
| 9 | * Henry Spencer. |
| 10 | * |
| 11 | * Redistribution and use in source and binary forms, with or without |
| 12 | * modification, are permitted provided that the following conditions |
| 13 | * are met: |
| 14 | * 1. Redistributions of source code must retain the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer. |
| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer in the |
| 18 | * documentation and/or other materials provided with the distribution. |
| 19 | * 3. Neither the name of the University nor the names of its contributors |
| 20 | * may be used to endorse or promote products derived from this software |
| 21 | * without specific prior written permission. |
| 22 | * |
| 23 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 24 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 25 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 26 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 27 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 28 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 29 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 30 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 31 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 32 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 33 | * SUCH DAMAGE. |
| 34 | * |
| 35 | * @(#)engine.c 8.5 (Berkeley) 3/20/94 |
| 36 | */ |
| 37 | |
| 38 | /* |
| 39 | * The matching engine and friends. This file is #included by regexec.c |
| 40 | * after suitable #defines of a variety of macros used herein, so that |
| 41 | * different state representations can be used without duplicating masses |
| 42 | * of code. |
| 43 | */ |
| 44 | |
| 45 | #ifdef SNAMES |
| 46 | #define matcher smatcher |
| 47 | #define fast sfast |
| 48 | #define slow sslow |
| 49 | #define dissect sdissect |
| 50 | #define backref sbackref |
| 51 | #define step sstep |
| 52 | #define print sprint |
| 53 | #define at sat |
| 54 | #define match smat |
| 55 | #define nope snope |
| 56 | #endif |
| 57 | #ifdef LNAMES |
| 58 | #define matcher lmatcher |
| 59 | #define fast lfast |
| 60 | #define slow lslow |
| 61 | #define dissect ldissect |
| 62 | #define backref lbackref |
| 63 | #define step lstep |
| 64 | #define print lprint |
| 65 | #define at lat |
| 66 | #define match lmat |
| 67 | #define nope lnope |
| 68 | #endif |
| 69 | |
| 70 | /* another structure passed up and down to avoid zillions of parameters */ |
| 71 | struct match { |
| 72 | struct re_guts *g; |
| 73 | int eflags; |
| 74 | llvm_regmatch_t *pmatch; /* [nsub+1] (0 element unused) */ |
| 75 | const char *offp; /* offsets work from here */ |
| 76 | const char *beginp; /* start of string -- virtual NUL precedes */ |
| 77 | const char *endp; /* end of string -- virtual NUL here */ |
| 78 | const char *coldp; /* can be no match starting before here */ |
| 79 | const char **lastpos; /* [nplus+1] */ |
| 80 | STATEVARS; |
| 81 | states st; /* current states */ |
| 82 | states fresh; /* states for a fresh start */ |
| 83 | states tmp; /* temporary */ |
| 84 | states empty; /* empty set of states */ |
| 85 | }; |
| 86 | |
| 87 | static int matcher(struct re_guts *, const char *, size_t, |
| 88 | llvm_regmatch_t[], int); |
| 89 | static const char *dissect(struct match *, const char *, const char *, sopno, |
| 90 | sopno); |
| 91 | static const char *backref(struct match *, const char *, const char *, sopno, |
| 92 | sopno, sopno, int); |
| 93 | static const char *fast(struct match *, const char *, const char *, sopno, sopno); |
| 94 | static const char *slow(struct match *, const char *, const char *, sopno, sopno); |
| 95 | static states step(struct re_guts *, sopno, sopno, states, int, states); |
| 96 | #define MAX_RECURSION 100 |
| 97 | #define BOL (OUT+1) |
| 98 | #define EOL (BOL+1) |
| 99 | #define BOLEOL (BOL+2) |
| 100 | #define NOTHING (BOL+3) |
| 101 | #define BOW (BOL+4) |
| 102 | #define EOW (BOL+5) |
| 103 | #define CODEMAX (BOL+5) /* highest code used */ |
| 104 | #define NONCHAR(c) ((c) > CHAR_MAX) |
| 105 | #define NNONCHAR (CODEMAX-CHAR_MAX) |
| 106 | #ifdef REDEBUG |
| 107 | static void print(struct match *, char *, states, int, FILE *); |
| 108 | #endif |
| 109 | #ifdef REDEBUG |
| 110 | static void at(struct match *, char *, char *, char *, sopno, sopno); |
| 111 | #endif |
| 112 | #ifdef REDEBUG |
| 113 | static char *pchar(int); |
| 114 | #endif |
| 115 | |
| 116 | #ifdef REDEBUG |
| 117 | #define SP(t, s, c) print(m, t, s, c, stdout) |
| 118 | #define AT(t, p1, p2, s1, s2) at(m, t, p1, p2, s1, s2) |
| 119 | #define NOTE(str) { if (m->eflags®_TRACE) (void)printf("=%s\n", (str)); } |
| 120 | static int nope = 0; |
| 121 | #else |
| 122 | #define SP(t, s, c) /* nothing */ |
| 123 | #define AT(t, p1, p2, s1, s2) /* nothing */ |
| 124 | #define NOTE(s) /* nothing */ |
| 125 | #endif |
| 126 | |
| 127 | /* |
| 128 | - matcher - the actual matching engine |
| 129 | */ |
| 130 | static int /* 0 success, REG_NOMATCH failure */ |
| 131 | matcher(struct re_guts *g, const char *string, size_t nmatch, |
| 132 | llvm_regmatch_t pmatch[], |
| 133 | int eflags) |
| 134 | { |
| 135 | const char *endp; |
| 136 | size_t i; |
| 137 | struct match mv; |
| 138 | struct match *m = &mv; |
| 139 | const char *dp; |
| 140 | const sopno gf = g->firststate+1; /* +1 for OEND */ |
| 141 | const sopno gl = g->laststate; |
| 142 | const char *start; |
| 143 | const char *stop; |
| 144 | |
| 145 | /* simplify the situation where possible */ |
| 146 | if (g->cflags®_NOSUB) |
| 147 | nmatch = 0; |
| 148 | if (eflags®_STARTEND) { |
| 149 | start = string + pmatch[0].rm_so; |
| 150 | stop = string + pmatch[0].rm_eo; |
| 151 | } else { |
| 152 | start = string; |
| 153 | stop = start + strlen(start); |
| 154 | } |
| 155 | if (stop < start) |
| 156 | return(REG_INVARG); |
| 157 | |
| 158 | /* prescreening; this does wonders for this rather slow code */ |
| 159 | if (g->must != NULL) { |
| 160 | for (dp = start; dp < stop; dp++) |
| 161 | if (*dp == g->must[0] && stop - dp >= g->mlen && |
| 162 | memcmp(dp, g->must, (size_t)g->mlen) == 0) |
| 163 | break; |
| 164 | if (dp == stop) /* we didn't find g->must */ |
| 165 | return(REG_NOMATCH); |
| 166 | } |
| 167 | |
| 168 | /* match struct setup */ |
| 169 | m->g = g; |
| 170 | m->eflags = eflags; |
| 171 | m->pmatch = NULL; |
| 172 | m->lastpos = NULL; |
| 173 | m->offp = string; |
| 174 | m->beginp = start; |
| 175 | m->endp = stop; |
| 176 | STATESETUP(m, 4); |
| 177 | SETUP(m->st); |
| 178 | SETUP(m->fresh); |
| 179 | SETUP(m->tmp); |
| 180 | SETUP(m->empty); |
| 181 | CLEAR(m->empty); |
| 182 | |
| 183 | /* this loop does only one repetition except for backrefs */ |
| 184 | for (;;) { |
| 185 | endp = fast(m, start, stop, gf, gl); |
| 186 | if (endp == NULL) { /* a miss */ |
| 187 | free(m->pmatch); |
| 188 | free((void*)m->lastpos); |
| 189 | STATETEARDOWN(m); |
| 190 | return(REG_NOMATCH); |
| 191 | } |
| 192 | if (nmatch == 0 && !g->backrefs) |
| 193 | break; /* no further info needed */ |
| 194 | |
| 195 | /* where? */ |
| 196 | assert(m->coldp != NULL); |
| 197 | for (;;) { |
| 198 | NOTE("finding start"); |
| 199 | endp = slow(m, m->coldp, stop, gf, gl); |
| 200 | if (endp != NULL) |
| 201 | break; |
| 202 | assert(m->coldp < m->endp); |
| 203 | m->coldp++; |
| 204 | } |
| 205 | if (nmatch == 1 && !g->backrefs) |
| 206 | break; /* no further info needed */ |
| 207 | |
| 208 | /* oh my, he wants the subexpressions... */ |
| 209 | if (m->pmatch == NULL) |
| 210 | m->pmatch = (llvm_regmatch_t *)malloc((m->g->nsub + 1) * |
| 211 | sizeof(llvm_regmatch_t)); |
| 212 | if (m->pmatch == NULL) { |
| 213 | STATETEARDOWN(m); |
| 214 | return(REG_ESPACE); |
| 215 | } |
| 216 | for (i = 1; i <= m->g->nsub; i++) |
| 217 | m->pmatch[i].rm_so = m->pmatch[i].rm_eo = -1; |
| 218 | if (!g->backrefs && !(m->eflags®_BACKR)) { |
| 219 | NOTE("dissecting"); |
| 220 | dp = dissect(m, m->coldp, endp, gf, gl); |
| 221 | } else { |
| 222 | if (g->nplus > 0 && m->lastpos == NULL) |
| 223 | m->lastpos = (const char **)malloc((g->nplus+1) * |
| 224 | sizeof(char *)); |
| 225 | if (g->nplus > 0 && m->lastpos == NULL) { |
| 226 | free(m->pmatch); |
| 227 | STATETEARDOWN(m); |
| 228 | return(REG_ESPACE); |
| 229 | } |
| 230 | NOTE("backref dissect"); |
| 231 | dp = backref(m, m->coldp, endp, gf, gl, (sopno)0, 0); |
| 232 | } |
| 233 | if (dp != NULL) |
| 234 | break; |
| 235 | |
| 236 | /* uh-oh... we couldn't find a subexpression-level match */ |
| 237 | assert(g->backrefs); /* must be back references doing it */ |
| 238 | assert(g->nplus == 0 || m->lastpos != NULL); |
| 239 | for (;;) { |
| 240 | if (dp != NULL || endp <= m->coldp) |
| 241 | break; /* defeat */ |
| 242 | NOTE("backoff"); |
| 243 | endp = slow(m, m->coldp, endp-1, gf, gl); |
| 244 | if (endp == NULL) |
| 245 | break; /* defeat */ |
| 246 | /* try it on a shorter possibility */ |
| 247 | #ifndef NDEBUG |
| 248 | for (i = 1; i <= m->g->nsub; i++) { |
| 249 | assert(m->pmatch[i].rm_so == -1); |
| 250 | assert(m->pmatch[i].rm_eo == -1); |
| 251 | } |
| 252 | #endif |
| 253 | NOTE("backoff dissect"); |
| 254 | dp = backref(m, m->coldp, endp, gf, gl, (sopno)0, 0); |
| 255 | } |
| 256 | assert(dp == NULL || dp == endp); |
| 257 | if (dp != NULL) /* found a shorter one */ |
| 258 | break; |
| 259 | |
| 260 | /* despite initial appearances, there is no match here */ |
| 261 | NOTE("false alarm"); |
| 262 | if (m->coldp == stop) |
| 263 | break; |
| 264 | start = m->coldp + 1; /* recycle starting later */ |
| 265 | } |
| 266 | |
| 267 | /* fill in the details if requested */ |
| 268 | if (nmatch > 0) { |
| 269 | pmatch[0].rm_so = m->coldp - m->offp; |
| 270 | pmatch[0].rm_eo = endp - m->offp; |
| 271 | } |
| 272 | if (nmatch > 1) { |
| 273 | assert(m->pmatch != NULL); |
| 274 | for (i = 1; i < nmatch; i++) |
| 275 | if (i <= m->g->nsub) |
| 276 | pmatch[i] = m->pmatch[i]; |
| 277 | else { |
| 278 | pmatch[i].rm_so = -1; |
| 279 | pmatch[i].rm_eo = -1; |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | if (m->pmatch != NULL) |
| 284 | free((char *)m->pmatch); |
| 285 | if (m->lastpos != NULL) |
| 286 | free((char *)m->lastpos); |
| 287 | STATETEARDOWN(m); |
| 288 | return(0); |
| 289 | } |
| 290 | |
| 291 | /* |
| 292 | - dissect - figure out what matched what, no back references |
| 293 | */ |
| 294 | static const char * /* == stop (success) always */ |
| 295 | dissect(struct match *m, const char *start, const char *stop, sopno startst, |
| 296 | sopno stopst) |
| 297 | { |
| 298 | int i; |
| 299 | sopno ss; /* start sop of current subRE */ |
| 300 | sopno es; /* end sop of current subRE */ |
| 301 | const char *sp; /* start of string matched by it */ |
| 302 | const char *stp; /* string matched by it cannot pass here */ |
| 303 | const char *rest; /* start of rest of string */ |
| 304 | const char *tail; /* string unmatched by rest of RE */ |
| 305 | sopno ssub; /* start sop of subsubRE */ |
| 306 | sopno esub; /* end sop of subsubRE */ |
| 307 | const char *ssp; /* start of string matched by subsubRE */ |
| 308 | const char *sep; /* end of string matched by subsubRE */ |
| 309 | const char *oldssp; /* previous ssp */ |
| 310 | |
| 311 | AT("diss", start, stop, startst, stopst); |
| 312 | sp = start; |
| 313 | for (ss = startst; ss < stopst; ss = es) { |
| 314 | /* identify end of subRE */ |
| 315 | es = ss; |
| 316 | switch (OP(m->g->strip[es])) { |
| 317 | case OPLUS_: |
| 318 | case OQUEST_: |
| 319 | es += OPND(m->g->strip[es]); |
| 320 | break; |
| 321 | case OCH_: |
| 322 | while (OP(m->g->strip[es]) != O_CH) |
| 323 | es += OPND(m->g->strip[es]); |
| 324 | break; |
| 325 | } |
| 326 | es++; |
| 327 | |
| 328 | /* figure out what it matched */ |
| 329 | switch (OP(m->g->strip[ss])) { |
| 330 | case OEND: |
| 331 | assert(nope); |
| 332 | break; |
| 333 | case OCHAR: |
| 334 | sp++; |
| 335 | break; |
| 336 | case OBOL: |
| 337 | case OEOL: |
| 338 | case OBOW: |
| 339 | case OEOW: |
| 340 | break; |
| 341 | case OANY: |
| 342 | case OANYOF: |
| 343 | sp++; |
| 344 | break; |
| 345 | case OBACK_: |
| 346 | case O_BACK: |
| 347 | assert(nope); |
| 348 | break; |
| 349 | /* cases where length of match is hard to find */ |
| 350 | case OQUEST_: |
| 351 | stp = stop; |
| 352 | for (;;) { |
| 353 | /* how long could this one be? */ |
| 354 | rest = slow(m, sp, stp, ss, es); |
| 355 | assert(rest != NULL); /* it did match */ |
| 356 | /* could the rest match the rest? */ |
| 357 | tail = slow(m, rest, stop, es, stopst); |
| 358 | if (tail == stop) |
| 359 | break; /* yes! */ |
| 360 | /* no -- try a shorter match for this one */ |
| 361 | stp = rest - 1; |
| 362 | assert(stp >= sp); /* it did work */ |
| 363 | } |
| 364 | ssub = ss + 1; |
| 365 | esub = es - 1; |
| 366 | /* did innards match? */ |
| 367 | if (slow(m, sp, rest, ssub, esub) != NULL) { |
| 368 | const char *dp = dissect(m, sp, rest, ssub, esub); |
| 369 | (void)dp; /* avoid warning if assertions off */ |
| 370 | assert(dp == rest); |
| 371 | } else /* no */ |
| 372 | assert(sp == rest); |
| 373 | sp = rest; |
| 374 | break; |
| 375 | case OPLUS_: |
| 376 | stp = stop; |
| 377 | for (;;) { |
| 378 | /* how long could this one be? */ |
| 379 | rest = slow(m, sp, stp, ss, es); |
| 380 | assert(rest != NULL); /* it did match */ |
| 381 | /* could the rest match the rest? */ |
| 382 | tail = slow(m, rest, stop, es, stopst); |
| 383 | if (tail == stop) |
| 384 | break; /* yes! */ |
| 385 | /* no -- try a shorter match for this one */ |
| 386 | stp = rest - 1; |
| 387 | assert(stp >= sp); /* it did work */ |
| 388 | } |
| 389 | ssub = ss + 1; |
| 390 | esub = es - 1; |
| 391 | ssp = sp; |
| 392 | oldssp = ssp; |
| 393 | for (;;) { /* find last match of innards */ |
| 394 | sep = slow(m, ssp, rest, ssub, esub); |
| 395 | if (sep == NULL || sep == ssp) |
| 396 | break; /* failed or matched null */ |
| 397 | oldssp = ssp; /* on to next try */ |
| 398 | ssp = sep; |
| 399 | } |
| 400 | if (sep == NULL) { |
| 401 | /* last successful match */ |
| 402 | sep = ssp; |
| 403 | ssp = oldssp; |
| 404 | } |
| 405 | assert(sep == rest); /* must exhaust substring */ |
| 406 | assert(slow(m, ssp, sep, ssub, esub) == rest); |
| 407 | { |
| 408 | const char *dp = dissect(m, ssp, sep, ssub, esub); |
| 409 | (void)dp; /* avoid warning if assertions off */ |
| 410 | assert(dp == sep); |
| 411 | } |
| 412 | sp = rest; |
| 413 | break; |
| 414 | case OCH_: |
| 415 | stp = stop; |
| 416 | for (;;) { |
| 417 | /* how long could this one be? */ |
| 418 | rest = slow(m, sp, stp, ss, es); |
| 419 | assert(rest != NULL); /* it did match */ |
| 420 | /* could the rest match the rest? */ |
| 421 | tail = slow(m, rest, stop, es, stopst); |
| 422 | if (tail == stop) |
| 423 | break; /* yes! */ |
| 424 | /* no -- try a shorter match for this one */ |
| 425 | stp = rest - 1; |
| 426 | assert(stp >= sp); /* it did work */ |
| 427 | } |
| 428 | ssub = ss + 1; |
| 429 | esub = ss + OPND(m->g->strip[ss]) - 1; |
| 430 | assert(OP(m->g->strip[esub]) == OOR1); |
| 431 | for (;;) { /* find first matching branch */ |
| 432 | if (slow(m, sp, rest, ssub, esub) == rest) |
| 433 | break; /* it matched all of it */ |
| 434 | /* that one missed, try next one */ |
| 435 | assert(OP(m->g->strip[esub]) == OOR1); |
| 436 | esub++; |
| 437 | assert(OP(m->g->strip[esub]) == OOR2); |
| 438 | ssub = esub + 1; |
| 439 | esub += OPND(m->g->strip[esub]); |
| 440 | if (OP(m->g->strip[esub]) == OOR2) |
| 441 | esub--; |
| 442 | else |
| 443 | assert(OP(m->g->strip[esub]) == O_CH); |
| 444 | } |
| 445 | { |
| 446 | const char *dp = dissect(m, sp, rest, ssub, esub); |
| 447 | (void)dp; /* avoid warning if assertions off */ |
| 448 | assert(dp == rest); |
| 449 | } |
| 450 | sp = rest; |
| 451 | break; |
| 452 | case O_PLUS: |
| 453 | case O_QUEST: |
| 454 | case OOR1: |
| 455 | case OOR2: |
| 456 | case O_CH: |
| 457 | assert(nope); |
| 458 | break; |
| 459 | case OLPAREN: |
| 460 | i = OPND(m->g->strip[ss]); |
| 461 | assert(0 < i && i <= m->g->nsub); |
| 462 | m->pmatch[i].rm_so = sp - m->offp; |
| 463 | break; |
| 464 | case ORPAREN: |
| 465 | i = OPND(m->g->strip[ss]); |
| 466 | assert(0 < i && i <= m->g->nsub); |
| 467 | m->pmatch[i].rm_eo = sp - m->offp; |
| 468 | break; |
| 469 | default: /* uh oh */ |
| 470 | assert(nope); |
| 471 | break; |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | assert(sp == stop); |
| 476 | return(sp); |
| 477 | } |
| 478 | |
| 479 | /* |
| 480 | - backref - figure out what matched what, figuring in back references |
| 481 | */ |
| 482 | static const char * /* == stop (success) or NULL (failure) */ |
| 483 | backref(struct match *m, const char *start, const char *stop, sopno startst, |
| 484 | sopno stopst, sopno lev, int rec) /* PLUS nesting level */ |
| 485 | { |
| 486 | int i; |
| 487 | sopno ss; /* start sop of current subRE */ |
| 488 | const char *sp; /* start of string matched by it */ |
| 489 | sopno ssub; /* start sop of subsubRE */ |
| 490 | sopno esub; /* end sop of subsubRE */ |
| 491 | const char *ssp; /* start of string matched by subsubRE */ |
| 492 | const char *dp; |
| 493 | size_t len; |
| 494 | int hard; |
| 495 | sop s; |
| 496 | llvm_regoff_t offsave; |
| 497 | cset *cs; |
| 498 | |
| 499 | AT("back", start, stop, startst, stopst); |
| 500 | sp = start; |
| 501 | |
| 502 | /* get as far as we can with easy stuff */ |
| 503 | hard = 0; |
| 504 | for (ss = startst; !hard && ss < stopst; ss++) |
| 505 | switch (OP(s = m->g->strip[ss])) { |
| 506 | case OCHAR: |
| 507 | if (sp == stop || *sp++ != (char)OPND(s)) |
| 508 | return(NULL); |
| 509 | break; |
| 510 | case OANY: |
| 511 | if (sp == stop) |
| 512 | return(NULL); |
| 513 | sp++; |
| 514 | break; |
| 515 | case OANYOF: |
| 516 | cs = &m->g->sets[OPND(s)]; |
| 517 | if (sp == stop || !CHIN(cs, *sp++)) |
| 518 | return(NULL); |
| 519 | break; |
| 520 | case OBOL: |
| 521 | if ( (sp == m->beginp && !(m->eflags®_NOTBOL)) || |
| 522 | (sp < m->endp && *(sp-1) == '\n' && |
| 523 | (m->g->cflags®_NEWLINE)) ) |
| 524 | { /* yes */ } |
| 525 | else |
| 526 | return(NULL); |
| 527 | break; |
| 528 | case OEOL: |
| 529 | if ( (sp == m->endp && !(m->eflags®_NOTEOL)) || |
| 530 | (sp < m->endp && *sp == '\n' && |
| 531 | (m->g->cflags®_NEWLINE)) ) |
| 532 | { /* yes */ } |
| 533 | else |
| 534 | return(NULL); |
| 535 | break; |
| 536 | case OBOW: |
| 537 | if (( (sp == m->beginp && !(m->eflags®_NOTBOL)) || |
| 538 | (sp < m->endp && *(sp-1) == '\n' && |
| 539 | (m->g->cflags®_NEWLINE)) || |
| 540 | (sp > m->beginp && |
| 541 | !ISWORD(*(sp-1))) ) && |
| 542 | (sp < m->endp && ISWORD(*sp)) ) |
| 543 | { /* yes */ } |
| 544 | else |
| 545 | return(NULL); |
| 546 | break; |
| 547 | case OEOW: |
| 548 | if (( (sp == m->endp && !(m->eflags®_NOTEOL)) || |
| 549 | (sp < m->endp && *sp == '\n' && |
| 550 | (m->g->cflags®_NEWLINE)) || |
| 551 | (sp < m->endp && !ISWORD(*sp)) ) && |
| 552 | (sp > m->beginp && ISWORD(*(sp-1))) ) |
| 553 | { /* yes */ } |
| 554 | else |
| 555 | return(NULL); |
| 556 | break; |
| 557 | case O_QUEST: |
| 558 | break; |
| 559 | case OOR1: /* matches null but needs to skip */ |
| 560 | ss++; |
| 561 | s = m->g->strip[ss]; |
| 562 | do { |
| 563 | assert(OP(s) == OOR2); |
| 564 | ss += OPND(s); |
| 565 | } while (OP(s = m->g->strip[ss]) != O_CH); |
| 566 | /* note that the ss++ gets us past the O_CH */ |
| 567 | break; |
| 568 | default: /* have to make a choice */ |
| 569 | hard = 1; |
| 570 | break; |
| 571 | } |
| 572 | if (!hard) { /* that was it! */ |
| 573 | if (sp != stop) |
| 574 | return(NULL); |
| 575 | return(sp); |
| 576 | } |
| 577 | ss--; /* adjust for the for's final increment */ |
| 578 | |
| 579 | /* the hard stuff */ |
| 580 | AT("hard", sp, stop, ss, stopst); |
| 581 | s = m->g->strip[ss]; |
| 582 | switch (OP(s)) { |
| 583 | case OBACK_: /* the vilest depths */ |
| 584 | i = OPND(s); |
| 585 | assert(0 < i && i <= m->g->nsub); |
| 586 | if (m->pmatch[i].rm_eo == -1) |
| 587 | return(NULL); |
| 588 | assert(m->pmatch[i].rm_so != -1); |
| 589 | len = m->pmatch[i].rm_eo - m->pmatch[i].rm_so; |
| 590 | if (len == 0 && rec++ > MAX_RECURSION) |
| 591 | return(NULL); |
| 592 | assert(stop - m->beginp >= len); |
| 593 | if (sp > stop - len) |
| 594 | return(NULL); /* not enough left to match */ |
| 595 | ssp = m->offp + m->pmatch[i].rm_so; |
| 596 | if (memcmp(sp, ssp, len) != 0) |
| 597 | return(NULL); |
| 598 | while (m->g->strip[ss] != SOP(O_BACK, i)) |
| 599 | ss++; |
| 600 | return(backref(m, sp+len, stop, ss+1, stopst, lev, rec)); |
| 601 | break; |
| 602 | case OQUEST_: /* to null or not */ |
| 603 | dp = backref(m, sp, stop, ss+1, stopst, lev, rec); |
| 604 | if (dp != NULL) |
| 605 | return(dp); /* not */ |
| 606 | return(backref(m, sp, stop, ss+OPND(s)+1, stopst, lev, rec)); |
| 607 | break; |
| 608 | case OPLUS_: |
| 609 | assert(m->lastpos != NULL); |
| 610 | assert(lev+1 <= m->g->nplus); |
| 611 | m->lastpos[lev+1] = sp; |
| 612 | return(backref(m, sp, stop, ss+1, stopst, lev+1, rec)); |
| 613 | break; |
| 614 | case O_PLUS: |
| 615 | if (sp == m->lastpos[lev]) /* last pass matched null */ |
| 616 | return(backref(m, sp, stop, ss+1, stopst, lev-1, rec)); |
| 617 | /* try another pass */ |
| 618 | m->lastpos[lev] = sp; |
| 619 | dp = backref(m, sp, stop, ss-OPND(s)+1, stopst, lev, rec); |
| 620 | if (dp == NULL) |
| 621 | return(backref(m, sp, stop, ss+1, stopst, lev-1, rec)); |
| 622 | else |
| 623 | return(dp); |
| 624 | break; |
| 625 | case OCH_: /* find the right one, if any */ |
| 626 | ssub = ss + 1; |
| 627 | esub = ss + OPND(s) - 1; |
| 628 | assert(OP(m->g->strip[esub]) == OOR1); |
| 629 | for (;;) { /* find first matching branch */ |
| 630 | dp = backref(m, sp, stop, ssub, esub, lev, rec); |
| 631 | if (dp != NULL) |
| 632 | return(dp); |
| 633 | /* that one missed, try next one */ |
| 634 | if (OP(m->g->strip[esub]) == O_CH) |
| 635 | return(NULL); /* there is none */ |
| 636 | esub++; |
| 637 | assert(OP(m->g->strip[esub]) == OOR2); |
| 638 | ssub = esub + 1; |
| 639 | esub += OPND(m->g->strip[esub]); |
| 640 | if (OP(m->g->strip[esub]) == OOR2) |
| 641 | esub--; |
| 642 | else |
| 643 | assert(OP(m->g->strip[esub]) == O_CH); |
| 644 | } |
| 645 | break; |
| 646 | case OLPAREN: /* must undo assignment if rest fails */ |
| 647 | i = OPND(s); |
| 648 | assert(0 < i && i <= m->g->nsub); |
| 649 | offsave = m->pmatch[i].rm_so; |
| 650 | m->pmatch[i].rm_so = sp - m->offp; |
| 651 | dp = backref(m, sp, stop, ss+1, stopst, lev, rec); |
| 652 | if (dp != NULL) |
| 653 | return(dp); |
| 654 | m->pmatch[i].rm_so = offsave; |
| 655 | return(NULL); |
| 656 | break; |
| 657 | case ORPAREN: /* must undo assignment if rest fails */ |
| 658 | i = OPND(s); |
| 659 | assert(0 < i && i <= m->g->nsub); |
| 660 | offsave = m->pmatch[i].rm_eo; |
| 661 | m->pmatch[i].rm_eo = sp - m->offp; |
| 662 | dp = backref(m, sp, stop, ss+1, stopst, lev, rec); |
| 663 | if (dp != NULL) |
| 664 | return(dp); |
| 665 | m->pmatch[i].rm_eo = offsave; |
| 666 | return(NULL); |
| 667 | break; |
| 668 | default: /* uh oh */ |
| 669 | assert(nope); |
| 670 | break; |
| 671 | } |
| 672 | |
| 673 | /* "can't happen" */ |
| 674 | assert(nope); |
| 675 | /* NOTREACHED */ |
| 676 | return NULL; |
| 677 | } |
| 678 | |
| 679 | /* |
| 680 | - fast - step through the string at top speed |
| 681 | */ |
| 682 | static const char * /* where tentative match ended, or NULL */ |
| 683 | fast(struct match *m, const char *start, const char *stop, sopno startst, |
| 684 | sopno stopst) |
| 685 | { |
| 686 | states st = m->st; |
| 687 | states fresh = m->fresh; |
| 688 | states tmp = m->tmp; |
| 689 | const char *p = start; |
| 690 | int c = (start == m->beginp) ? OUT : *(start-1); |
| 691 | int lastc; /* previous c */ |
| 692 | int flagch; |
| 693 | int i; |
| 694 | const char *coldp; /* last p after which no match was underway */ |
| 695 | |
| 696 | CLEAR(st); |
| 697 | SET1(st, startst); |
| 698 | st = step(m->g, startst, stopst, st, NOTHING, st); |
| 699 | ASSIGN(fresh, st); |
| 700 | SP("start", st, *p); |
| 701 | coldp = NULL; |
| 702 | for (;;) { |
| 703 | /* next character */ |
| 704 | lastc = c; |
| 705 | c = (p == m->endp) ? OUT : *p; |
| 706 | if (EQ(st, fresh)) |
| 707 | coldp = p; |
| 708 | |
| 709 | /* is there an EOL and/or BOL between lastc and c? */ |
| 710 | flagch = '\0'; |
| 711 | i = 0; |
| 712 | if ( (lastc == '\n' && m->g->cflags®_NEWLINE) || |
| 713 | (lastc == OUT && !(m->eflags®_NOTBOL)) ) { |
| 714 | flagch = BOL; |
| 715 | i = m->g->nbol; |
| 716 | } |
| 717 | if ( (c == '\n' && m->g->cflags®_NEWLINE) || |
| 718 | (c == OUT && !(m->eflags®_NOTEOL)) ) { |
| 719 | flagch = (flagch == BOL) ? BOLEOL : EOL; |
| 720 | i += m->g->neol; |
| 721 | } |
| 722 | if (i != 0) { |
| 723 | for (; i > 0; i--) |
| 724 | st = step(m->g, startst, stopst, st, flagch, st); |
| 725 | SP("boleol", st, c); |
| 726 | } |
| 727 | |
| 728 | /* how about a word boundary? */ |
| 729 | if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) && |
| 730 | (c != OUT && ISWORD(c)) ) { |
| 731 | flagch = BOW; |
| 732 | } |
| 733 | if ( (lastc != OUT && ISWORD(lastc)) && |
| 734 | (flagch == EOL || (c != OUT && !ISWORD(c))) ) { |
| 735 | flagch = EOW; |
| 736 | } |
| 737 | if (flagch == BOW || flagch == EOW) { |
| 738 | st = step(m->g, startst, stopst, st, flagch, st); |
| 739 | SP("boweow", st, c); |
| 740 | } |
| 741 | |
| 742 | /* are we done? */ |
| 743 | if (ISSET(st, stopst) || p == stop) |
| 744 | break; /* NOTE BREAK OUT */ |
| 745 | |
| 746 | /* no, we must deal with this character */ |
| 747 | ASSIGN(tmp, st); |
| 748 | ASSIGN(st, fresh); |
| 749 | assert(c != OUT); |
| 750 | st = step(m->g, startst, stopst, tmp, c, st); |
| 751 | SP("aft", st, c); |
| 752 | assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st)); |
| 753 | p++; |
| 754 | } |
| 755 | |
| 756 | assert(coldp != NULL); |
| 757 | m->coldp = coldp; |
| 758 | if (ISSET(st, stopst)) |
| 759 | return(p+1); |
| 760 | else |
| 761 | return(NULL); |
| 762 | } |
| 763 | |
| 764 | /* |
| 765 | - slow - step through the string more deliberately |
| 766 | */ |
| 767 | static const char * /* where it ended */ |
| 768 | slow(struct match *m, const char *start, const char *stop, sopno startst, |
| 769 | sopno stopst) |
| 770 | { |
| 771 | states st = m->st; |
| 772 | states empty = m->empty; |
| 773 | states tmp = m->tmp; |
| 774 | const char *p = start; |
| 775 | int c = (start == m->beginp) ? OUT : *(start-1); |
| 776 | int lastc; /* previous c */ |
| 777 | int flagch; |
| 778 | int i; |
| 779 | const char *matchp; /* last p at which a match ended */ |
| 780 | |
| 781 | AT("slow", start, stop, startst, stopst); |
| 782 | CLEAR(st); |
| 783 | SET1(st, startst); |
| 784 | SP("sstart", st, *p); |
| 785 | st = step(m->g, startst, stopst, st, NOTHING, st); |
| 786 | matchp = NULL; |
| 787 | for (;;) { |
| 788 | /* next character */ |
| 789 | lastc = c; |
| 790 | c = (p == m->endp) ? OUT : *p; |
| 791 | |
| 792 | /* is there an EOL and/or BOL between lastc and c? */ |
| 793 | flagch = '\0'; |
| 794 | i = 0; |
| 795 | if ( (lastc == '\n' && m->g->cflags®_NEWLINE) || |
| 796 | (lastc == OUT && !(m->eflags®_NOTBOL)) ) { |
| 797 | flagch = BOL; |
| 798 | i = m->g->nbol; |
| 799 | } |
| 800 | if ( (c == '\n' && m->g->cflags®_NEWLINE) || |
| 801 | (c == OUT && !(m->eflags®_NOTEOL)) ) { |
| 802 | flagch = (flagch == BOL) ? BOLEOL : EOL; |
| 803 | i += m->g->neol; |
| 804 | } |
| 805 | if (i != 0) { |
| 806 | for (; i > 0; i--) |
| 807 | st = step(m->g, startst, stopst, st, flagch, st); |
| 808 | SP("sboleol", st, c); |
| 809 | } |
| 810 | |
| 811 | /* how about a word boundary? */ |
| 812 | if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) && |
| 813 | (c != OUT && ISWORD(c)) ) { |
| 814 | flagch = BOW; |
| 815 | } |
| 816 | if ( (lastc != OUT && ISWORD(lastc)) && |
| 817 | (flagch == EOL || (c != OUT && !ISWORD(c))) ) { |
| 818 | flagch = EOW; |
| 819 | } |
| 820 | if (flagch == BOW || flagch == EOW) { |
| 821 | st = step(m->g, startst, stopst, st, flagch, st); |
| 822 | SP("sboweow", st, c); |
| 823 | } |
| 824 | |
| 825 | /* are we done? */ |
| 826 | if (ISSET(st, stopst)) |
| 827 | matchp = p; |
| 828 | if (EQ(st, empty) || p == stop) |
| 829 | break; /* NOTE BREAK OUT */ |
| 830 | |
| 831 | /* no, we must deal with this character */ |
| 832 | ASSIGN(tmp, st); |
| 833 | ASSIGN(st, empty); |
| 834 | assert(c != OUT); |
| 835 | st = step(m->g, startst, stopst, tmp, c, st); |
| 836 | SP("saft", st, c); |
| 837 | assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st)); |
| 838 | p++; |
| 839 | } |
| 840 | |
| 841 | return(matchp); |
| 842 | } |
| 843 | |
| 844 | |
| 845 | /* |
| 846 | - step - map set of states reachable before char to set reachable after |
| 847 | */ |
| 848 | static states |
| 849 | step(struct re_guts *g, |
| 850 | sopno start, /* start state within strip */ |
| 851 | sopno stop, /* state after stop state within strip */ |
| 852 | states bef, /* states reachable before */ |
| 853 | int ch, /* character or NONCHAR code */ |
| 854 | states aft) /* states already known reachable after */ |
| 855 | { |
| 856 | cset *cs; |
| 857 | sop s; |
| 858 | sopno pc; |
| 859 | onestate here; /* note, macros know this name */ |
| 860 | sopno look; |
| 861 | int i; |
| 862 | |
| 863 | for (pc = start, INIT(here, pc); pc != stop; pc++, INC(here)) { |
| 864 | s = g->strip[pc]; |
| 865 | switch (OP(s)) { |
| 866 | case OEND: |
| 867 | assert(pc == stop-1); |
| 868 | break; |
| 869 | case OCHAR: |
| 870 | /* only characters can match */ |
| 871 | assert(!NONCHAR(ch) || ch != (char)OPND(s)); |
| 872 | if (ch == (char)OPND(s)) |
| 873 | FWD(aft, bef, 1); |
| 874 | break; |
| 875 | case OBOL: |
| 876 | if (ch == BOL || ch == BOLEOL) |
| 877 | FWD(aft, bef, 1); |
| 878 | break; |
| 879 | case OEOL: |
| 880 | if (ch == EOL || ch == BOLEOL) |
| 881 | FWD(aft, bef, 1); |
| 882 | break; |
| 883 | case OBOW: |
| 884 | if (ch == BOW) |
| 885 | FWD(aft, bef, 1); |
| 886 | break; |
| 887 | case OEOW: |
| 888 | if (ch == EOW) |
| 889 | FWD(aft, bef, 1); |
| 890 | break; |
| 891 | case OANY: |
| 892 | if (!NONCHAR(ch)) |
| 893 | FWD(aft, bef, 1); |
| 894 | break; |
| 895 | case OANYOF: |
| 896 | cs = &g->sets[OPND(s)]; |
| 897 | if (!NONCHAR(ch) && CHIN(cs, ch)) |
| 898 | FWD(aft, bef, 1); |
| 899 | break; |
| 900 | case OBACK_: /* ignored here */ |
| 901 | case O_BACK: |
| 902 | FWD(aft, aft, 1); |
| 903 | break; |
| 904 | case OPLUS_: /* forward, this is just an empty */ |
| 905 | FWD(aft, aft, 1); |
| 906 | break; |
| 907 | case O_PLUS: /* both forward and back */ |
| 908 | FWD(aft, aft, 1); |
| 909 | i = ISSETBACK(aft, OPND(s)); |
| 910 | BACK(aft, aft, OPND(s)); |
| 911 | if (!i && ISSETBACK(aft, OPND(s))) { |
| 912 | /* oho, must reconsider loop body */ |
| 913 | pc -= OPND(s) + 1; |
| 914 | INIT(here, pc); |
| 915 | } |
| 916 | break; |
| 917 | case OQUEST_: /* two branches, both forward */ |
| 918 | FWD(aft, aft, 1); |
| 919 | FWD(aft, aft, OPND(s)); |
| 920 | break; |
| 921 | case O_QUEST: /* just an empty */ |
| 922 | FWD(aft, aft, 1); |
| 923 | break; |
| 924 | case OLPAREN: /* not significant here */ |
| 925 | case ORPAREN: |
| 926 | FWD(aft, aft, 1); |
| 927 | break; |
| 928 | case OCH_: /* mark the first two branches */ |
| 929 | FWD(aft, aft, 1); |
| 930 | assert(OP(g->strip[pc+OPND(s)]) == OOR2); |
| 931 | FWD(aft, aft, OPND(s)); |
| 932 | break; |
| 933 | case OOR1: /* done a branch, find the O_CH */ |
| 934 | if (ISSTATEIN(aft, here)) { |
| 935 | for (look = 1; |
| 936 | OP(s = g->strip[pc+look]) != O_CH; |
| 937 | look += OPND(s)) |
| 938 | assert(OP(s) == OOR2); |
| 939 | FWD(aft, aft, look); |
| 940 | } |
| 941 | break; |
| 942 | case OOR2: /* propagate OCH_'s marking */ |
| 943 | FWD(aft, aft, 1); |
| 944 | if (OP(g->strip[pc+OPND(s)]) != O_CH) { |
| 945 | assert(OP(g->strip[pc+OPND(s)]) == OOR2); |
| 946 | FWD(aft, aft, OPND(s)); |
| 947 | } |
| 948 | break; |
| 949 | case O_CH: /* just empty */ |
| 950 | FWD(aft, aft, 1); |
| 951 | break; |
| 952 | default: /* ooooops... */ |
| 953 | assert(nope); |
| 954 | break; |
| 955 | } |
| 956 | } |
| 957 | |
| 958 | return(aft); |
| 959 | } |
| 960 | |
| 961 | #ifdef REDEBUG |
| 962 | /* |
| 963 | - print - print a set of states |
| 964 | */ |
| 965 | static void |
| 966 | print(struct match *m, char *caption, states st, int ch, FILE *d) |
| 967 | { |
| 968 | struct re_guts *g = m->g; |
| 969 | int i; |
| 970 | int first = 1; |
| 971 | |
| 972 | if (!(m->eflags®_TRACE)) |
| 973 | return; |
| 974 | |
| 975 | (void)fprintf(d, "%s", caption); |
| 976 | if (ch != '\0') |
| 977 | (void)fprintf(d, " %s", pchar(ch)); |
| 978 | for (i = 0; i < g->nstates; i++) |
| 979 | if (ISSET(st, i)) { |
| 980 | (void)fprintf(d, "%s%d", (first) ? "\t" : ", ", i); |
| 981 | first = 0; |
| 982 | } |
| 983 | (void)fprintf(d, "\n"); |
| 984 | } |
| 985 | |
| 986 | /* |
| 987 | - at - print current situation |
| 988 | */ |
| 989 | static void |
| 990 | at(struct match *m, char *title, char *start, char *stop, sopno startst, |
| 991 | sopno stopst) |
| 992 | { |
| 993 | if (!(m->eflags®_TRACE)) |
| 994 | return; |
| 995 | |
| 996 | (void)printf("%s %s-", title, pchar(*start)); |
| 997 | (void)printf("%s ", pchar(*stop)); |
| 998 | (void)printf("%ld-%ld\n", (long)startst, (long)stopst); |
| 999 | } |
| 1000 | |
| 1001 | #ifndef PCHARDONE |
| 1002 | #define PCHARDONE /* never again */ |
| 1003 | /* |
| 1004 | - pchar - make a character printable |
| 1005 | * |
| 1006 | * Is this identical to regchar() over in debug.c? Well, yes. But a |
| 1007 | * duplicate here avoids having a debugging-capable regexec.o tied to |
| 1008 | * a matching debug.o, and this is convenient. It all disappears in |
| 1009 | * the non-debug compilation anyway, so it doesn't matter much. |
| 1010 | */ |
| 1011 | static char * /* -> representation */ |
| 1012 | pchar(int ch) |
| 1013 | { |
| 1014 | static char pbuf[10]; |
| 1015 | |
| 1016 | if (isprint(ch) || ch == ' ') |
| 1017 | (void)snprintf(pbuf, sizeof pbuf, "%c", ch); |
| 1018 | else |
| 1019 | (void)snprintf(pbuf, sizeof pbuf, "\\%o", ch); |
| 1020 | return(pbuf); |
| 1021 | } |
| 1022 | #endif |
| 1023 | #endif |
| 1024 | |
| 1025 | #undef matcher |
| 1026 | #undef fast |
| 1027 | #undef slow |
| 1028 | #undef dissect |
| 1029 | #undef backref |
| 1030 | #undef step |
| 1031 | #undef print |
| 1032 | #undef at |
| 1033 | #undef match |
| 1034 | #undef nope |