| 1 | /* |
| 2 | * re_*exec and friends - match REs |
| 3 | * |
| 4 | * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved. |
| 5 | * |
| 6 | * Development of this software was funded, in part, by Cray Research Inc., |
| 7 | * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics |
| 8 | * Corporation, none of whom are responsible for the results. The author |
| 9 | * thanks all of them. |
| 10 | * |
| 11 | * Redistribution and use in source and binary forms -- with or without |
| 12 | * modification -- are permitted for any purpose, provided that |
| 13 | * redistributions in source form retain this entire copyright notice and |
| 14 | * indicate the origin and nature of any modifications. |
| 15 | * |
| 16 | * I'd appreciate being given credit for this package in the documentation |
| 17 | * of software which uses it, but that is not a requirement. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| 20 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY |
| 21 | * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL |
| 22 | * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 23 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 24 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 25 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 26 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 27 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 28 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | * |
| 30 | */ |
| 31 | |
| 32 | #include "regguts.h" |
| 33 | |
| 34 | |
| 35 | |
| 36 | /* lazy-DFA representation */ |
| 37 | struct arcp { /* "pointer" to an outarc */ |
| 38 | struct sset *ss; |
| 39 | color co; |
| 40 | }; |
| 41 | |
| 42 | struct sset { /* state set */ |
| 43 | unsigned *states; /* pointer to bitvector */ |
| 44 | unsigned hash; /* hash of bitvector */ |
| 45 | # define HASH(bv, nw) (((nw) == 1) ? *(bv) : hash(bv, nw)) |
| 46 | # define HIT(h,bv,ss,nw) ((ss)->hash == (h) && ((nw) == 1 || \ |
| 47 | memcmp(VS(bv), VS((ss)->states), (nw)*sizeof(unsigned)) == 0)) |
| 48 | int flags; |
| 49 | # define STARTER 01 /* the initial state set */ |
| 50 | # define POSTSTATE 02 /* includes the goal state */ |
| 51 | # define LOCKED 04 /* locked in cache */ |
| 52 | # define NOPROGRESS 010 /* zero-progress state set */ |
| 53 | struct arcp ins; /* chain of inarcs pointing here */ |
| 54 | chr *lastseen; /* last entered on arrival here */ |
| 55 | struct sset **outs; /* outarc vector indexed by color */ |
| 56 | struct arcp *inchain; /* chain-pointer vector for outarcs */ |
| 57 | }; |
| 58 | |
| 59 | struct dfa { |
| 60 | int nssets; /* size of cache */ |
| 61 | int nssused; /* how many entries occupied yet */ |
| 62 | int nstates; /* number of states */ |
| 63 | int ncolors; /* length of outarc and inchain vectors */ |
| 64 | int wordsper; /* length of state-set bitvectors */ |
| 65 | struct sset *ssets; /* state-set cache */ |
| 66 | unsigned *statesarea; /* bitvector storage */ |
| 67 | unsigned *work; /* pointer to work area within statesarea */ |
| 68 | struct sset **outsarea; /* outarc-vector storage */ |
| 69 | struct arcp *incarea; /* inchain storage */ |
| 70 | struct cnfa *cnfa; |
| 71 | struct colormap *cm; |
| 72 | chr *lastpost; /* location of last cache-flushed success */ |
| 73 | chr *lastnopr; /* location of last cache-flushed NOPROGRESS */ |
| 74 | struct sset *search; /* replacement-search-pointer memory */ |
| 75 | int cptsmalloced; /* were the areas individually malloced? */ |
| 76 | char *mallocarea; /* self, or master malloced area, or NULL */ |
| 77 | }; |
| 78 | |
| 79 | #define WORK 1 /* number of work bitvectors needed */ |
| 80 | |
| 81 | /* setup for non-malloc allocation for small cases */ |
| 82 | #define FEWSTATES 20 /* must be less than UBITS */ |
| 83 | #define FEWCOLORS 15 |
| 84 | struct smalldfa { |
| 85 | struct dfa dfa; |
| 86 | struct sset ssets[FEWSTATES*2]; |
| 87 | unsigned statesarea[FEWSTATES*2 + WORK]; |
| 88 | struct sset *outsarea[FEWSTATES*2 * FEWCOLORS]; |
| 89 | struct arcp incarea[FEWSTATES*2 * FEWCOLORS]; |
| 90 | }; |
| 91 | #define DOMALLOC ((struct smalldfa *)NULL) /* force malloc */ |
| 92 | |
| 93 | |
| 94 | |
| 95 | /* internal variables, bundled for easy passing around */ |
| 96 | struct vars { |
| 97 | regex_t *re; |
| 98 | struct guts *g; |
| 99 | int eflags; /* copies of arguments */ |
| 100 | size_t nmatch; |
| 101 | regmatch_t *pmatch; |
| 102 | rm_detail_t *details; |
| 103 | chr *start; /* start of string */ |
| 104 | chr *stop; /* just past end of string */ |
| 105 | int err; /* error code if any (0 none) */ |
| 106 | regoff_t *mem; /* memory vector for backtracking */ |
| 107 | struct smalldfa dfa1; |
| 108 | struct smalldfa dfa2; |
| 109 | }; |
| 110 | #define VISERR(vv) ((vv)->err != 0) /* have we seen an error yet? */ |
| 111 | #define ISERR() VISERR(v) |
| 112 | #define VERR(vv,e) (((vv)->err) ? (vv)->err : ((vv)->err = (e))) |
| 113 | #define ERR(e) VERR(v, e) /* record an error */ |
| 114 | #define NOERR() {if (ISERR()) return v->err;} /* if error seen, return it */ |
| 115 | #define OFF(p) ((p) - v->start) |
| 116 | #define LOFF(p) ((long)OFF(p)) |
| 117 | |
| 118 | |
| 119 | |
| 120 | /* |
| 121 | * forward declarations |
| 122 | */ |
| 123 | /* =====^!^===== begin forwards =====^!^===== */ |
| 124 | /* automatically gathered by fwd; do not hand-edit */ |
| 125 | /* === regexec.c === */ |
| 126 | int exec _ANSI_ARGS_((regex_t *, CONST chr *, size_t, rm_detail_t *, size_t, regmatch_t [], int)); |
| 127 | static int find _ANSI_ARGS_((struct vars *, struct cnfa *, struct colormap *)); |
| 128 | static int cfind _ANSI_ARGS_((struct vars *, struct cnfa *, struct colormap *)); |
| 129 | static int cfindloop _ANSI_ARGS_((struct vars *, struct cnfa *, struct colormap *, struct dfa *, struct dfa *, chr **)); |
| 130 | static VOID zapsubs _ANSI_ARGS_((regmatch_t *, size_t)); |
| 131 | static VOID zapmem _ANSI_ARGS_((struct vars *, struct subre *)); |
| 132 | static VOID subset _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 133 | static int dissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 134 | static int condissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 135 | static int altdissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 136 | static int cdissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 137 | static int ccondissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 138 | static int crevdissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 139 | static int cbrdissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 140 | static int caltdissect _ANSI_ARGS_((struct vars *, struct subre *, chr *, chr *)); |
| 141 | /* === rege_dfa.c === */ |
| 142 | static chr *longest _ANSI_ARGS_((struct vars *, struct dfa *, chr *, chr *, int *)); |
| 143 | static chr *shortest _ANSI_ARGS_((struct vars *, struct dfa *, chr *, chr *, chr *, chr **, int *)); |
| 144 | static chr *lastcold _ANSI_ARGS_((struct vars *, struct dfa *)); |
| 145 | static struct dfa *newdfa _ANSI_ARGS_((struct vars *, struct cnfa *, struct colormap *, struct smalldfa *)); |
| 146 | static VOID freedfa _ANSI_ARGS_((struct dfa *)); |
| 147 | static unsigned hash _ANSI_ARGS_((unsigned *, int)); |
| 148 | static struct sset *initialize _ANSI_ARGS_((struct vars *, struct dfa *, chr *)); |
| 149 | static struct sset *miss _ANSI_ARGS_((struct vars *, struct dfa *, struct sset *, pcolor, chr *, chr *)); |
| 150 | static int lacon _ANSI_ARGS_((struct vars *, struct cnfa *, chr *, pcolor)); |
| 151 | static struct sset *getvacant _ANSI_ARGS_((struct vars *, struct dfa *, chr *, chr *)); |
| 152 | static struct sset *pickss _ANSI_ARGS_((struct vars *, struct dfa *, chr *, chr *)); |
| 153 | /* automatically gathered by fwd; do not hand-edit */ |
| 154 | /* =====^!^===== end forwards =====^!^===== */ |
| 155 | |
| 156 | |
| 157 | |
| 158 | /* |
| 159 | - exec - match regular expression |
| 160 | ^ int exec(regex_t *, CONST chr *, size_t, rm_detail_t *, |
| 161 | ^ size_t, regmatch_t [], int); |
| 162 | */ |
| 163 | int |
| 164 | exec(re, string, len, details, nmatch, pmatch, flags) |
| 165 | regex_t *re; |
| 166 | CONST chr *string; |
| 167 | size_t len; |
| 168 | rm_detail_t *details; |
| 169 | size_t nmatch; |
| 170 | regmatch_t pmatch[]; |
| 171 | int flags; |
| 172 | { |
| 173 | struct vars var; |
| 174 | register struct vars *v = &var; |
| 175 | int st; |
| 176 | size_t n; |
| 177 | int backref; |
| 178 | # define LOCALMAT 20 |
| 179 | regmatch_t mat[LOCALMAT]; |
| 180 | # define LOCALMEM 40 |
| 181 | regoff_t mem[LOCALMEM]; |
| 182 | |
| 183 | /* sanity checks */ |
| 184 | if (re == NULL || string == NULL || re->re_magic != REMAGIC) |
| 185 | return REG_INVARG; |
| 186 | if (re->re_csize != sizeof(chr)) |
| 187 | return REG_MIXED; |
| 188 | |
| 189 | /* setup */ |
| 190 | v->re = re; |
| 191 | v->g = (struct guts *)re->re_guts; |
| 192 | if ((v->g->cflags®_EXPECT) && details == NULL) |
| 193 | return REG_INVARG; |
| 194 | if (v->g->info®_UIMPOSSIBLE) |
| 195 | return REG_NOMATCH; |
| 196 | backref = (v->g->info®_UBACKREF) ? 1 : 0; |
| 197 | v->eflags = flags; |
| 198 | if (v->g->cflags®_NOSUB) |
| 199 | nmatch = 0; /* override client */ |
| 200 | v->nmatch = nmatch; |
| 201 | if (backref) { |
| 202 | /* need work area */ |
| 203 | if (v->g->nsub + 1 <= LOCALMAT) |
| 204 | v->pmatch = mat; |
| 205 | else |
| 206 | v->pmatch = (regmatch_t *)MALLOC((v->g->nsub + 1) * |
| 207 | sizeof(regmatch_t)); |
| 208 | if (v->pmatch == NULL) |
| 209 | return REG_ESPACE; |
| 210 | v->nmatch = v->g->nsub + 1; |
| 211 | } else |
| 212 | v->pmatch = pmatch; |
| 213 | v->details = details; |
| 214 | v->start = (chr *)string; |
| 215 | v->stop = (chr *)string + len; |
| 216 | v->err = 0; |
| 217 | if (backref) { |
| 218 | /* need retry memory */ |
| 219 | assert(v->g->ntree >= 0); |
| 220 | n = (size_t)v->g->ntree; |
| 221 | if (n <= LOCALMEM) |
| 222 | v->mem = mem; |
| 223 | else |
| 224 | v->mem = (regoff_t *)MALLOC(n*sizeof(regoff_t)); |
| 225 | if (v->mem == NULL) { |
| 226 | if (v->pmatch != pmatch && v->pmatch != mat) |
| 227 | FREE(v->pmatch); |
| 228 | return REG_ESPACE; |
| 229 | } |
| 230 | } else |
| 231 | v->mem = NULL; |
| 232 | |
| 233 | /* do it */ |
| 234 | assert(v->g->tree != NULL); |
| 235 | if (backref) |
| 236 | st = cfind(v, &v->g->tree->cnfa, &v->g->cmap); |
| 237 | else |
| 238 | st = find(v, &v->g->tree->cnfa, &v->g->cmap); |
| 239 | |
| 240 | /* copy (portion of) match vector over if necessary */ |
| 241 | if (st == REG_OKAY && v->pmatch != pmatch && nmatch > 0) { |
| 242 | zapsubs(pmatch, nmatch); |
| 243 | n = (nmatch < v->nmatch) ? nmatch : v->nmatch; |
| 244 | memcpy(VS(pmatch), VS(v->pmatch), n*sizeof(regmatch_t)); |
| 245 | } |
| 246 | |
| 247 | /* clean up */ |
| 248 | if (v->pmatch != pmatch && v->pmatch != mat) |
| 249 | FREE(v->pmatch); |
| 250 | if (v->mem != NULL && v->mem != mem) |
| 251 | FREE(v->mem); |
| 252 | return st; |
| 253 | } |
| 254 | |
| 255 | /* |
| 256 | - find - find a match for the main NFA (no-complications case) |
| 257 | ^ static int find(struct vars *, struct cnfa *, struct colormap *); |
| 258 | */ |
| 259 | static int |
| 260 | find(v, cnfa, cm) |
| 261 | struct vars *v; |
| 262 | struct cnfa *cnfa; |
| 263 | struct colormap *cm; |
| 264 | { |
| 265 | struct dfa *s; |
| 266 | struct dfa *d; |
| 267 | chr *begin; |
| 268 | chr *end = NULL; |
| 269 | chr *cold; |
| 270 | chr *open; /* open and close of range of possible starts */ |
| 271 | chr *close; |
| 272 | int hitend; |
| 273 | int shorter = (v->g->tree->flags&SHORTER) ? 1 : 0; |
| 274 | |
| 275 | /* first, a shot with the search RE */ |
| 276 | s = newdfa(v, &v->g->search, cm, &v->dfa1); |
| 277 | assert(!(ISERR() && s != NULL)); |
| 278 | NOERR(); |
| 279 | MDEBUG(("\nsearch at %ld\n", LOFF(v->start))); |
| 280 | cold = NULL; |
| 281 | close = shortest(v, s, v->start, v->start, v->stop, &cold, (int *)NULL); |
| 282 | freedfa(s); |
| 283 | NOERR(); |
| 284 | if (v->g->cflags®_EXPECT) { |
| 285 | assert(v->details != NULL); |
| 286 | if (cold != NULL) |
| 287 | v->details->rm_extend.rm_so = OFF(cold); |
| 288 | else |
| 289 | v->details->rm_extend.rm_so = OFF(v->stop); |
| 290 | v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */ |
| 291 | } |
| 292 | if (close == NULL) /* not found */ |
| 293 | return REG_NOMATCH; |
| 294 | if (v->nmatch == 0) /* found, don't need exact location */ |
| 295 | return REG_OKAY; |
| 296 | |
| 297 | /* find starting point and match */ |
| 298 | assert(cold != NULL); |
| 299 | open = cold; |
| 300 | cold = NULL; |
| 301 | MDEBUG(("between %ld and %ld\n", LOFF(open), LOFF(close))); |
| 302 | d = newdfa(v, cnfa, cm, &v->dfa1); |
| 303 | assert(!(ISERR() && d != NULL)); |
| 304 | NOERR(); |
| 305 | for (begin = open; begin <= close; begin++) { |
| 306 | MDEBUG(("\nfind trying at %ld\n", LOFF(begin))); |
| 307 | if (shorter) |
| 308 | end = shortest(v, d, begin, begin, v->stop, |
| 309 | (chr **)NULL, &hitend); |
| 310 | else |
| 311 | end = longest(v, d, begin, v->stop, &hitend); |
| 312 | NOERR(); |
| 313 | if (hitend && cold == NULL) |
| 314 | cold = begin; |
| 315 | if (end != NULL) |
| 316 | break; /* NOTE BREAK OUT */ |
| 317 | } |
| 318 | assert(end != NULL); /* search RE succeeded so loop should */ |
| 319 | freedfa(d); |
| 320 | |
| 321 | /* and pin down details */ |
| 322 | assert(v->nmatch > 0); |
| 323 | v->pmatch[0].rm_so = OFF(begin); |
| 324 | v->pmatch[0].rm_eo = OFF(end); |
| 325 | if (v->g->cflags®_EXPECT) { |
| 326 | if (cold != NULL) |
| 327 | v->details->rm_extend.rm_so = OFF(cold); |
| 328 | else |
| 329 | v->details->rm_extend.rm_so = OFF(v->stop); |
| 330 | v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */ |
| 331 | } |
| 332 | if (v->nmatch == 1) /* no need for submatches */ |
| 333 | return REG_OKAY; |
| 334 | |
| 335 | /* submatches */ |
| 336 | zapsubs(v->pmatch, v->nmatch); |
| 337 | return dissect(v, v->g->tree, begin, end); |
| 338 | } |
| 339 | |
| 340 | /* |
| 341 | - cfind - find a match for the main NFA (with complications) |
| 342 | ^ static int cfind(struct vars *, struct cnfa *, struct colormap *); |
| 343 | */ |
| 344 | static int |
| 345 | cfind(v, cnfa, cm) |
| 346 | struct vars *v; |
| 347 | struct cnfa *cnfa; |
| 348 | struct colormap *cm; |
| 349 | { |
| 350 | struct dfa *s; |
| 351 | struct dfa *d; |
| 352 | chr *cold; |
| 353 | int ret; |
| 354 | |
| 355 | s = newdfa(v, &v->g->search, cm, &v->dfa1); |
| 356 | NOERR(); |
| 357 | d = newdfa(v, cnfa, cm, &v->dfa2); |
| 358 | if (ISERR()) { |
| 359 | assert(d == NULL); |
| 360 | freedfa(s); |
| 361 | return v->err; |
| 362 | } |
| 363 | |
| 364 | ret = cfindloop(v, cnfa, cm, d, s, &cold); |
| 365 | |
| 366 | freedfa(d); |
| 367 | freedfa(s); |
| 368 | NOERR(); |
| 369 | if (v->g->cflags®_EXPECT) { |
| 370 | assert(v->details != NULL); |
| 371 | if (cold != NULL) |
| 372 | v->details->rm_extend.rm_so = OFF(cold); |
| 373 | else |
| 374 | v->details->rm_extend.rm_so = OFF(v->stop); |
| 375 | v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */ |
| 376 | } |
| 377 | return ret; |
| 378 | } |
| 379 | |
| 380 | /* |
| 381 | - cfindloop - the heart of cfind |
| 382 | ^ static int cfindloop(struct vars *, struct cnfa *, struct colormap *, |
| 383 | ^ struct dfa *, struct dfa *, chr **); |
| 384 | */ |
| 385 | static int |
| 386 | cfindloop(v, cnfa, cm, d, s, coldp) |
| 387 | struct vars *v; |
| 388 | struct cnfa *cnfa; |
| 389 | struct colormap *cm; |
| 390 | struct dfa *d; |
| 391 | struct dfa *s; |
| 392 | chr **coldp; /* where to put coldstart pointer */ |
| 393 | { |
| 394 | chr *begin; |
| 395 | chr *end; |
| 396 | chr *cold; |
| 397 | chr *open; /* open and close of range of possible starts */ |
| 398 | chr *close; |
| 399 | chr *estart; |
| 400 | chr *estop; |
| 401 | int er; |
| 402 | int shorter = v->g->tree->flags&SHORTER; |
| 403 | int hitend; |
| 404 | |
| 405 | assert(d != NULL && s != NULL); |
| 406 | cold = NULL; |
| 407 | close = v->start; |
| 408 | do { |
| 409 | MDEBUG(("\ncsearch at %ld\n", LOFF(close))); |
| 410 | close = shortest(v, s, close, close, v->stop, &cold, (int *)NULL); |
| 411 | if (close == NULL) |
| 412 | break; /* NOTE BREAK */ |
| 413 | assert(cold != NULL); |
| 414 | open = cold; |
| 415 | cold = NULL; |
| 416 | MDEBUG(("cbetween %ld and %ld\n", LOFF(open), LOFF(close))); |
| 417 | for (begin = open; begin <= close; begin++) { |
| 418 | MDEBUG(("\ncfind trying at %ld\n", LOFF(begin))); |
| 419 | estart = begin; |
| 420 | estop = v->stop; |
| 421 | for (;;) { |
| 422 | if (shorter) |
| 423 | end = shortest(v, d, begin, estart, |
| 424 | estop, (chr **)NULL, &hitend); |
| 425 | else |
| 426 | end = longest(v, d, begin, estop, |
| 427 | &hitend); |
| 428 | if (hitend && cold == NULL) |
| 429 | cold = begin; |
| 430 | if (end == NULL) |
| 431 | break; /* NOTE BREAK OUT */ |
| 432 | MDEBUG(("tentative end %ld\n", LOFF(end))); |
| 433 | zapsubs(v->pmatch, v->nmatch); |
| 434 | zapmem(v, v->g->tree); |
| 435 | er = cdissect(v, v->g->tree, begin, end); |
| 436 | if (er == REG_OKAY) { |
| 437 | if (v->nmatch > 0) { |
| 438 | v->pmatch[0].rm_so = OFF(begin); |
| 439 | v->pmatch[0].rm_eo = OFF(end); |
| 440 | } |
| 441 | *coldp = cold; |
| 442 | return REG_OKAY; |
| 443 | } |
| 444 | if (er != REG_NOMATCH) { |
| 445 | ERR(er); |
| 446 | return er; |
| 447 | } |
| 448 | if ((shorter) ? end == estop : end == begin) { |
| 449 | /* no point in trying again */ |
| 450 | *coldp = cold; |
| 451 | return REG_NOMATCH; |
| 452 | } |
| 453 | /* go around and try again */ |
| 454 | if (shorter) |
| 455 | estart = end + 1; |
| 456 | else |
| 457 | estop = end - 1; |
| 458 | } |
| 459 | } |
| 460 | } while (close < v->stop); |
| 461 | |
| 462 | *coldp = cold; |
| 463 | return REG_NOMATCH; |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | - zapsubs - initialize the subexpression matches to "no match" |
| 468 | ^ static VOID zapsubs(regmatch_t *, size_t); |
| 469 | */ |
| 470 | static VOID |
| 471 | zapsubs(p, n) |
| 472 | regmatch_t *p; |
| 473 | size_t n; |
| 474 | { |
| 475 | size_t i; |
| 476 | |
| 477 | for (i = n-1; i > 0; i--) { |
| 478 | p[i].rm_so = -1; |
| 479 | p[i].rm_eo = -1; |
| 480 | } |
| 481 | } |
| 482 | |
| 483 | /* |
| 484 | - zapmem - initialize the retry memory of a subtree to zeros |
| 485 | ^ static VOID zapmem(struct vars *, struct subre *); |
| 486 | */ |
| 487 | static VOID |
| 488 | zapmem(v, t) |
| 489 | struct vars *v; |
| 490 | struct subre *t; |
| 491 | { |
| 492 | if (t == NULL) |
| 493 | return; |
| 494 | |
| 495 | assert(v->mem != NULL); |
| 496 | v->mem[t->retry] = 0; |
| 497 | if (t->op == '(') { |
| 498 | assert(t->subno > 0); |
| 499 | v->pmatch[t->subno].rm_so = -1; |
| 500 | v->pmatch[t->subno].rm_eo = -1; |
| 501 | } |
| 502 | |
| 503 | if (t->left != NULL) |
| 504 | zapmem(v, t->left); |
| 505 | if (t->right != NULL) |
| 506 | zapmem(v, t->right); |
| 507 | } |
| 508 | |
| 509 | /* |
| 510 | - subset - set any subexpression relevant to a successful subre |
| 511 | ^ static VOID subset(struct vars *, struct subre *, chr *, chr *); |
| 512 | */ |
| 513 | static VOID |
| 514 | subset(v, sub, begin, end) |
| 515 | struct vars *v; |
| 516 | struct subre *sub; |
| 517 | chr *begin; |
| 518 | chr *end; |
| 519 | { |
| 520 | int n = sub->subno; |
| 521 | |
| 522 | assert(n > 0); |
| 523 | if ((size_t)n >= v->nmatch) |
| 524 | return; |
| 525 | |
| 526 | MDEBUG(("setting %d\n", n)); |
| 527 | v->pmatch[n].rm_so = OFF(begin); |
| 528 | v->pmatch[n].rm_eo = OFF(end); |
| 529 | } |
| 530 | |
| 531 | /* |
| 532 | - dissect - determine subexpression matches (uncomplicated case) |
| 533 | ^ static int dissect(struct vars *, struct subre *, chr *, chr *); |
| 534 | */ |
| 535 | static int /* regexec return code */ |
| 536 | dissect(v, t, begin, end) |
| 537 | struct vars *v; |
| 538 | struct subre *t; |
| 539 | chr *begin; /* beginning of relevant substring */ |
| 540 | chr *end; /* end of same */ |
| 541 | { |
| 542 | assert(t != NULL); |
| 543 | MDEBUG(("dissect %ld-%ld\n", LOFF(begin), LOFF(end))); |
| 544 | |
| 545 | switch (t->op) { |
| 546 | case '=': /* terminal node */ |
| 547 | assert(t->left == NULL && t->right == NULL); |
| 548 | return REG_OKAY; /* no action, parent did the work */ |
| 549 | break; |
| 550 | case '|': /* alternation */ |
| 551 | assert(t->left != NULL); |
| 552 | return altdissect(v, t, begin, end); |
| 553 | break; |
| 554 | case 'b': /* back ref -- shouldn't be calling us! */ |
| 555 | return REG_ASSERT; |
| 556 | break; |
| 557 | case '.': /* concatenation */ |
| 558 | assert(t->left != NULL && t->right != NULL); |
| 559 | return condissect(v, t, begin, end); |
| 560 | break; |
| 561 | case '(': /* capturing */ |
| 562 | assert(t->left != NULL && t->right == NULL); |
| 563 | assert(t->subno > 0); |
| 564 | subset(v, t, begin, end); |
| 565 | return dissect(v, t->left, begin, end); |
| 566 | break; |
| 567 | default: |
| 568 | return REG_ASSERT; |
| 569 | break; |
| 570 | } |
| 571 | } |
| 572 | |
| 573 | /* |
| 574 | - condissect - determine concatenation subexpression matches (uncomplicated) |
| 575 | ^ static int condissect(struct vars *, struct subre *, chr *, chr *); |
| 576 | */ |
| 577 | static int /* regexec return code */ |
| 578 | condissect(v, t, begin, end) |
| 579 | struct vars *v; |
| 580 | struct subre *t; |
| 581 | chr *begin; /* beginning of relevant substring */ |
| 582 | chr *end; /* end of same */ |
| 583 | { |
| 584 | struct dfa *d; |
| 585 | struct dfa *d2; |
| 586 | chr *mid; |
| 587 | int i; |
| 588 | int shorter = (t->left->flags&SHORTER) ? 1 : 0; |
| 589 | chr *stop = (shorter) ? end : begin; |
| 590 | |
| 591 | assert(t->op == '.'); |
| 592 | assert(t->left != NULL && t->left->cnfa.nstates > 0); |
| 593 | assert(t->right != NULL && t->right->cnfa.nstates > 0); |
| 594 | |
| 595 | d = newdfa(v, &t->left->cnfa, &v->g->cmap, &v->dfa1); |
| 596 | NOERR(); |
| 597 | d2 = newdfa(v, &t->right->cnfa, &v->g->cmap, &v->dfa2); |
| 598 | if (ISERR()) { |
| 599 | assert(d2 == NULL); |
| 600 | freedfa(d); |
| 601 | return v->err; |
| 602 | } |
| 603 | |
| 604 | /* pick a tentative midpoint */ |
| 605 | if (shorter) |
| 606 | mid = shortest(v, d, begin, begin, end, (chr **)NULL, |
| 607 | (int *)NULL); |
| 608 | else |
| 609 | mid = longest(v, d, begin, end, (int *)NULL); |
| 610 | if (mid == NULL) { |
| 611 | freedfa(d); |
| 612 | freedfa(d2); |
| 613 | return REG_ASSERT; |
| 614 | } |
| 615 | MDEBUG(("tentative midpoint %ld\n", LOFF(mid))); |
| 616 | |
| 617 | /* iterate until satisfaction or failure */ |
| 618 | while (longest(v, d2, mid, end, (int *)NULL) != end) { |
| 619 | /* that midpoint didn't work, find a new one */ |
| 620 | if (mid == stop) { |
| 621 | /* all possibilities exhausted! */ |
| 622 | MDEBUG(("no midpoint!\n")); |
| 623 | freedfa(d); |
| 624 | freedfa(d2); |
| 625 | return REG_ASSERT; |
| 626 | } |
| 627 | if (shorter) |
| 628 | mid = shortest(v, d, begin, mid+1, end, (chr **)NULL, |
| 629 | (int *)NULL); |
| 630 | else |
| 631 | mid = longest(v, d, begin, mid-1, (int *)NULL); |
| 632 | if (mid == NULL) { |
| 633 | /* failed to find a new one! */ |
| 634 | MDEBUG(("failed midpoint!\n")); |
| 635 | freedfa(d); |
| 636 | freedfa(d2); |
| 637 | return REG_ASSERT; |
| 638 | } |
| 639 | MDEBUG(("new midpoint %ld\n", LOFF(mid))); |
| 640 | } |
| 641 | |
| 642 | /* satisfaction */ |
| 643 | MDEBUG(("successful\n")); |
| 644 | freedfa(d); |
| 645 | freedfa(d2); |
| 646 | i = dissect(v, t->left, begin, mid); |
| 647 | if (i != REG_OKAY) |
| 648 | return i; |
| 649 | return dissect(v, t->right, mid, end); |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | - altdissect - determine alternative subexpression matches (uncomplicated) |
| 654 | ^ static int altdissect(struct vars *, struct subre *, chr *, chr *); |
| 655 | */ |
| 656 | static int /* regexec return code */ |
| 657 | altdissect(v, t, begin, end) |
| 658 | struct vars *v; |
| 659 | struct subre *t; |
| 660 | chr *begin; /* beginning of relevant substring */ |
| 661 | chr *end; /* end of same */ |
| 662 | { |
| 663 | struct dfa *d; |
| 664 | int i; |
| 665 | |
| 666 | assert(t != NULL); |
| 667 | assert(t->op == '|'); |
| 668 | |
| 669 | for (i = 0; t != NULL; t = t->right, i++) { |
| 670 | MDEBUG(("trying %dth\n", i)); |
| 671 | assert(t->left != NULL && t->left->cnfa.nstates > 0); |
| 672 | d = newdfa(v, &t->left->cnfa, &v->g->cmap, &v->dfa1); |
| 673 | if (ISERR()) |
| 674 | return v->err; |
| 675 | if (longest(v, d, begin, end, (int *)NULL) == end) { |
| 676 | MDEBUG(("success\n")); |
| 677 | freedfa(d); |
| 678 | return dissect(v, t->left, begin, end); |
| 679 | } |
| 680 | freedfa(d); |
| 681 | } |
| 682 | return REG_ASSERT; /* none of them matched?!? */ |
| 683 | } |
| 684 | |
| 685 | /* |
| 686 | - cdissect - determine subexpression matches (with complications) |
| 687 | * The retry memory stores the offset of the trial midpoint from begin, |
| 688 | * plus 1 so that 0 uniquely means "clean slate". |
| 689 | ^ static int cdissect(struct vars *, struct subre *, chr *, chr *); |
| 690 | */ |
| 691 | static int /* regexec return code */ |
| 692 | cdissect(v, t, begin, end) |
| 693 | struct vars *v; |
| 694 | struct subre *t; |
| 695 | chr *begin; /* beginning of relevant substring */ |
| 696 | chr *end; /* end of same */ |
| 697 | { |
| 698 | int er; |
| 699 | |
| 700 | assert(t != NULL); |
| 701 | MDEBUG(("cdissect %ld-%ld %c\n", LOFF(begin), LOFF(end), t->op)); |
| 702 | |
| 703 | switch (t->op) { |
| 704 | case '=': /* terminal node */ |
| 705 | assert(t->left == NULL && t->right == NULL); |
| 706 | return REG_OKAY; /* no action, parent did the work */ |
| 707 | break; |
| 708 | case '|': /* alternation */ |
| 709 | assert(t->left != NULL); |
| 710 | return caltdissect(v, t, begin, end); |
| 711 | break; |
| 712 | case 'b': /* back ref -- shouldn't be calling us! */ |
| 713 | assert(t->left == NULL && t->right == NULL); |
| 714 | return cbrdissect(v, t, begin, end); |
| 715 | break; |
| 716 | case '.': /* concatenation */ |
| 717 | assert(t->left != NULL && t->right != NULL); |
| 718 | return ccondissect(v, t, begin, end); |
| 719 | break; |
| 720 | case '(': /* capturing */ |
| 721 | assert(t->left != NULL && t->right == NULL); |
| 722 | assert(t->subno > 0); |
| 723 | er = cdissect(v, t->left, begin, end); |
| 724 | if (er == REG_OKAY) |
| 725 | subset(v, t, begin, end); |
| 726 | return er; |
| 727 | break; |
| 728 | default: |
| 729 | return REG_ASSERT; |
| 730 | break; |
| 731 | } |
| 732 | } |
| 733 | |
| 734 | /* |
| 735 | - ccondissect - concatenation subexpression matches (with complications) |
| 736 | * The retry memory stores the offset of the trial midpoint from begin, |
| 737 | * plus 1 so that 0 uniquely means "clean slate". |
| 738 | ^ static int ccondissect(struct vars *, struct subre *, chr *, chr *); |
| 739 | */ |
| 740 | static int /* regexec return code */ |
| 741 | ccondissect(v, t, begin, end) |
| 742 | struct vars *v; |
| 743 | struct subre *t; |
| 744 | chr *begin; /* beginning of relevant substring */ |
| 745 | chr *end; /* end of same */ |
| 746 | { |
| 747 | struct dfa *d; |
| 748 | struct dfa *d2; |
| 749 | chr *mid; |
| 750 | int er; |
| 751 | |
| 752 | assert(t->op == '.'); |
| 753 | assert(t->left != NULL && t->left->cnfa.nstates > 0); |
| 754 | assert(t->right != NULL && t->right->cnfa.nstates > 0); |
| 755 | |
| 756 | if (t->left->flags&SHORTER) /* reverse scan */ |
| 757 | return crevdissect(v, t, begin, end); |
| 758 | |
| 759 | d = newdfa(v, &t->left->cnfa, &v->g->cmap, DOMALLOC); |
| 760 | if (ISERR()) |
| 761 | return v->err; |
| 762 | d2 = newdfa(v, &t->right->cnfa, &v->g->cmap, DOMALLOC); |
| 763 | if (ISERR()) { |
| 764 | freedfa(d); |
| 765 | return v->err; |
| 766 | } |
| 767 | MDEBUG(("cconcat %d\n", t->retry)); |
| 768 | |
| 769 | /* pick a tentative midpoint */ |
| 770 | if (v->mem[t->retry] == 0) { |
| 771 | mid = longest(v, d, begin, end, (int *)NULL); |
| 772 | if (mid == NULL) { |
| 773 | freedfa(d); |
| 774 | freedfa(d2); |
| 775 | return REG_NOMATCH; |
| 776 | } |
| 777 | MDEBUG(("tentative midpoint %ld\n", LOFF(mid))); |
| 778 | v->mem[t->retry] = (mid - begin) + 1; |
| 779 | } else { |
| 780 | mid = begin + (v->mem[t->retry] - 1); |
| 781 | MDEBUG(("working midpoint %ld\n", LOFF(mid))); |
| 782 | } |
| 783 | |
| 784 | /* iterate until satisfaction or failure */ |
| 785 | for (;;) { |
| 786 | /* try this midpoint on for size */ |
| 787 | er = cdissect(v, t->left, begin, mid); |
| 788 | if (er == REG_OKAY && |
| 789 | longest(v, d2, mid, end, (int *)NULL) == end && |
| 790 | (er = cdissect(v, t->right, mid, end)) == |
| 791 | REG_OKAY) |
| 792 | break; /* NOTE BREAK OUT */ |
| 793 | if (er != REG_OKAY && er != REG_NOMATCH) { |
| 794 | freedfa(d); |
| 795 | freedfa(d2); |
| 796 | return er; |
| 797 | } |
| 798 | |
| 799 | /* that midpoint didn't work, find a new one */ |
| 800 | if (mid == begin) { |
| 801 | /* all possibilities exhausted */ |
| 802 | MDEBUG(("%d no midpoint\n", t->retry)); |
| 803 | freedfa(d); |
| 804 | freedfa(d2); |
| 805 | return REG_NOMATCH; |
| 806 | } |
| 807 | mid = longest(v, d, begin, mid-1, (int *)NULL); |
| 808 | if (mid == NULL) { |
| 809 | /* failed to find a new one */ |
| 810 | MDEBUG(("%d failed midpoint\n", t->retry)); |
| 811 | freedfa(d); |
| 812 | freedfa(d2); |
| 813 | return REG_NOMATCH; |
| 814 | } |
| 815 | MDEBUG(("%d: new midpoint %ld\n", t->retry, LOFF(mid))); |
| 816 | v->mem[t->retry] = (mid - begin) + 1; |
| 817 | zapmem(v, t->left); |
| 818 | zapmem(v, t->right); |
| 819 | } |
| 820 | |
| 821 | /* satisfaction */ |
| 822 | MDEBUG(("successful\n")); |
| 823 | freedfa(d); |
| 824 | freedfa(d2); |
| 825 | return REG_OKAY; |
| 826 | } |
| 827 | |
| 828 | /* |
| 829 | - crevdissect - determine backref shortest-first subexpression matches |
| 830 | * The retry memory stores the offset of the trial midpoint from begin, |
| 831 | * plus 1 so that 0 uniquely means "clean slate". |
| 832 | ^ static int crevdissect(struct vars *, struct subre *, chr *, chr *); |
| 833 | */ |
| 834 | static int /* regexec return code */ |
| 835 | crevdissect(v, t, begin, end) |
| 836 | struct vars *v; |
| 837 | struct subre *t; |
| 838 | chr *begin; /* beginning of relevant substring */ |
| 839 | chr *end; /* end of same */ |
| 840 | { |
| 841 | struct dfa *d; |
| 842 | struct dfa *d2; |
| 843 | chr *mid; |
| 844 | int er; |
| 845 | |
| 846 | assert(t->op == '.'); |
| 847 | assert(t->left != NULL && t->left->cnfa.nstates > 0); |
| 848 | assert(t->right != NULL && t->right->cnfa.nstates > 0); |
| 849 | assert(t->left->flags&SHORTER); |
| 850 | |
| 851 | /* concatenation -- need to split the substring between parts */ |
| 852 | d = newdfa(v, &t->left->cnfa, &v->g->cmap, DOMALLOC); |
| 853 | if (ISERR()) |
| 854 | return v->err; |
| 855 | d2 = newdfa(v, &t->right->cnfa, &v->g->cmap, DOMALLOC); |
| 856 | if (ISERR()) { |
| 857 | freedfa(d); |
| 858 | return v->err; |
| 859 | } |
| 860 | MDEBUG(("crev %d\n", t->retry)); |
| 861 | |
| 862 | /* pick a tentative midpoint */ |
| 863 | if (v->mem[t->retry] == 0) { |
| 864 | mid = shortest(v, d, begin, begin, end, (chr **)NULL, (int *)NULL); |
| 865 | if (mid == NULL) { |
| 866 | freedfa(d); |
| 867 | freedfa(d2); |
| 868 | return REG_NOMATCH; |
| 869 | } |
| 870 | MDEBUG(("tentative midpoint %ld\n", LOFF(mid))); |
| 871 | v->mem[t->retry] = (mid - begin) + 1; |
| 872 | } else { |
| 873 | mid = begin + (v->mem[t->retry] - 1); |
| 874 | MDEBUG(("working midpoint %ld\n", LOFF(mid))); |
| 875 | } |
| 876 | |
| 877 | /* iterate until satisfaction or failure */ |
| 878 | for (;;) { |
| 879 | /* try this midpoint on for size */ |
| 880 | er = cdissect(v, t->left, begin, mid); |
| 881 | if (er == REG_OKAY && |
| 882 | longest(v, d2, mid, end, (int *)NULL) == end && |
| 883 | (er = cdissect(v, t->right, mid, end)) == |
| 884 | REG_OKAY) |
| 885 | break; /* NOTE BREAK OUT */ |
| 886 | if (er != REG_OKAY && er != REG_NOMATCH) { |
| 887 | freedfa(d); |
| 888 | freedfa(d2); |
| 889 | return er; |
| 890 | } |
| 891 | |
| 892 | /* that midpoint didn't work, find a new one */ |
| 893 | if (mid == end) { |
| 894 | /* all possibilities exhausted */ |
| 895 | MDEBUG(("%d no midpoint\n", t->retry)); |
| 896 | freedfa(d); |
| 897 | freedfa(d2); |
| 898 | return REG_NOMATCH; |
| 899 | } |
| 900 | mid = shortest(v, d, begin, mid+1, end, (chr **)NULL, (int *)NULL); |
| 901 | if (mid == NULL) { |
| 902 | /* failed to find a new one */ |
| 903 | MDEBUG(("%d failed midpoint\n", t->retry)); |
| 904 | freedfa(d); |
| 905 | freedfa(d2); |
| 906 | return REG_NOMATCH; |
| 907 | } |
| 908 | MDEBUG(("%d: new midpoint %ld\n", t->retry, LOFF(mid))); |
| 909 | v->mem[t->retry] = (mid - begin) + 1; |
| 910 | zapmem(v, t->left); |
| 911 | zapmem(v, t->right); |
| 912 | } |
| 913 | |
| 914 | /* satisfaction */ |
| 915 | MDEBUG(("successful\n")); |
| 916 | freedfa(d); |
| 917 | freedfa(d2); |
| 918 | return REG_OKAY; |
| 919 | } |
| 920 | |
| 921 | /* |
| 922 | - cbrdissect - determine backref subexpression matches |
| 923 | ^ static int cbrdissect(struct vars *, struct subre *, chr *, chr *); |
| 924 | */ |
| 925 | static int /* regexec return code */ |
| 926 | cbrdissect(v, t, begin, end) |
| 927 | struct vars *v; |
| 928 | struct subre *t; |
| 929 | chr *begin; /* beginning of relevant substring */ |
| 930 | chr *end; /* end of same */ |
| 931 | { |
| 932 | int i; |
| 933 | int n = t->subno; |
| 934 | size_t len; |
| 935 | chr *paren; |
| 936 | chr *p; |
| 937 | chr *stop; |
| 938 | int min = t->min; |
| 939 | int max = t->max; |
| 940 | |
| 941 | assert(t != NULL); |
| 942 | assert(t->op == 'b'); |
| 943 | assert(n >= 0); |
| 944 | assert((size_t)n < v->nmatch); |
| 945 | |
| 946 | MDEBUG(("cbackref n%d %d{%d-%d}\n", t->retry, n, min, max)); |
| 947 | |
| 948 | if (v->pmatch[n].rm_so == -1) |
| 949 | return REG_NOMATCH; |
| 950 | paren = v->start + v->pmatch[n].rm_so; |
| 951 | len = v->pmatch[n].rm_eo - v->pmatch[n].rm_so; |
| 952 | |
| 953 | /* no room to maneuver -- retries are pointless */ |
| 954 | if (v->mem[t->retry]) |
| 955 | return REG_NOMATCH; |
| 956 | v->mem[t->retry] = 1; |
| 957 | |
| 958 | /* special-case zero-length string */ |
| 959 | if (len == 0) { |
| 960 | if (begin == end) |
| 961 | return REG_OKAY; |
| 962 | return REG_NOMATCH; |
| 963 | } |
| 964 | |
| 965 | /* and too-short string */ |
| 966 | assert(end >= begin); |
| 967 | if ((size_t)(end - begin) < len) |
| 968 | return REG_NOMATCH; |
| 969 | stop = end - len; |
| 970 | |
| 971 | /* count occurrences */ |
| 972 | i = 0; |
| 973 | for (p = begin; p <= stop && (i < max || max == INFINITY); p += len) { |
| 974 | if ((*v->g->compare)(paren, p, len) != 0) |
| 975 | break; |
| 976 | i++; |
| 977 | } |
| 978 | MDEBUG(("cbackref found %d\n", i)); |
| 979 | |
| 980 | /* and sort it out */ |
| 981 | if (p != end) /* didn't consume all of it */ |
| 982 | return REG_NOMATCH; |
| 983 | if (min <= i && (i <= max || max == INFINITY)) |
| 984 | return REG_OKAY; |
| 985 | return REG_NOMATCH; /* out of range */ |
| 986 | } |
| 987 | |
| 988 | /* |
| 989 | - caltdissect - determine alternative subexpression matches (w. complications) |
| 990 | ^ static int caltdissect(struct vars *, struct subre *, chr *, chr *); |
| 991 | */ |
| 992 | static int /* regexec return code */ |
| 993 | caltdissect(v, t, begin, end) |
| 994 | struct vars *v; |
| 995 | struct subre *t; |
| 996 | chr *begin; /* beginning of relevant substring */ |
| 997 | chr *end; /* end of same */ |
| 998 | { |
| 999 | struct dfa *d; |
| 1000 | int er; |
| 1001 | # define UNTRIED 0 /* not yet tried at all */ |
| 1002 | # define TRYING 1 /* top matched, trying submatches */ |
| 1003 | # define TRIED 2 /* top didn't match or submatches exhausted */ |
| 1004 | |
| 1005 | if (t == NULL) |
| 1006 | return REG_NOMATCH; |
| 1007 | assert(t->op == '|'); |
| 1008 | if (v->mem[t->retry] == TRIED) |
| 1009 | return caltdissect(v, t->right, begin, end); |
| 1010 | |
| 1011 | MDEBUG(("calt n%d\n", t->retry)); |
| 1012 | assert(t->left != NULL); |
| 1013 | |
| 1014 | if (v->mem[t->retry] == UNTRIED) { |
| 1015 | d = newdfa(v, &t->left->cnfa, &v->g->cmap, DOMALLOC); |
| 1016 | if (ISERR()) |
| 1017 | return v->err; |
| 1018 | if (longest(v, d, begin, end, (int *)NULL) != end) { |
| 1019 | freedfa(d); |
| 1020 | v->mem[t->retry] = TRIED; |
| 1021 | return caltdissect(v, t->right, begin, end); |
| 1022 | } |
| 1023 | freedfa(d); |
| 1024 | MDEBUG(("calt matched\n")); |
| 1025 | v->mem[t->retry] = TRYING; |
| 1026 | } |
| 1027 | |
| 1028 | er = cdissect(v, t->left, begin, end); |
| 1029 | if (er != REG_NOMATCH) |
| 1030 | return er; |
| 1031 | |
| 1032 | v->mem[t->retry] = TRIED; |
| 1033 | return caltdissect(v, t->right, begin, end); |
| 1034 | } |
| 1035 | |
| 1036 | |
| 1037 | |
| 1038 | #include "rege_dfa.c" |