| 1 | /* NOTE: this is derived from Henry Spencer's regexp code, and should not |
| 2 | * confused with the original package (see point 3 below). Thanks, Henry! |
| 3 | */ |
| 4 | |
| 5 | /* Additional note: this code is very heavily munged from Henry's version |
| 6 | * in places. In some spots I've traded clarity for efficiency, so don't |
| 7 | * blame Henry for some of the lack of readability. |
| 8 | */ |
| 9 | |
| 10 | /* $Header: regcomp.c,v 3.0 89/10/18 15:22:29 lwall Locked $ |
| 11 | * |
| 12 | * $Log: regcomp.c,v $ |
| 13 | * Revision 3.0 89/10/18 15:22:29 lwall |
| 14 | * 3.0 baseline |
| 15 | * |
| 16 | */ |
| 17 | |
| 18 | /* |
| 19 | * regcomp and regexec -- regsub and regerror are not used in perl |
| 20 | * |
| 21 | * Copyright (c) 1986 by University of Toronto. |
| 22 | * Written by Henry Spencer. Not derived from licensed software. |
| 23 | * |
| 24 | * Permission is granted to anyone to use this software for any |
| 25 | * purpose on any computer system, and to redistribute it freely, |
| 26 | * subject to the following restrictions: |
| 27 | * |
| 28 | * 1. The author is not responsible for the consequences of use of |
| 29 | * this software, no matter how awful, even if they arise |
| 30 | * from defects in it. |
| 31 | * |
| 32 | * 2. The origin of this software must not be misrepresented, either |
| 33 | * by explicit claim or by omission. |
| 34 | * |
| 35 | * 3. Altered versions must be plainly marked as such, and must not |
| 36 | * be misrepresented as being the original software. |
| 37 | * |
| 38 | * |
| 39 | **** Alterations to Henry's code are... |
| 40 | **** |
| 41 | **** Copyright (c) 1989, Larry Wall |
| 42 | **** |
| 43 | **** You may distribute under the terms of the GNU General Public License |
| 44 | **** as specified in the README file that comes with the perl 3.0 kit. |
| 45 | * |
| 46 | * Beware that some of this code is subtly aware of the way operator |
| 47 | * precedence is structured in regular expressions. Serious changes in |
| 48 | * regular-expression syntax might require a total rethink. |
| 49 | */ |
| 50 | #include "EXTERN.h" |
| 51 | #include "perl.h" |
| 52 | #include "INTERN.h" |
| 53 | #include "regcomp.h" |
| 54 | |
| 55 | #ifndef STATIC |
| 56 | #define STATIC static |
| 57 | #endif |
| 58 | |
| 59 | #define ISMULT1(c) ((c) == '*' || (c) == '+' || (c) == '?') |
| 60 | #define ISMULT2(s) ((*s) == '*' || (*s) == '+' || (*s) == '?' || \ |
| 61 | ((*s) == '{' && regcurly(s))) |
| 62 | #define META "^$.[()|?+*\\" |
| 63 | |
| 64 | /* |
| 65 | * Flags to be passed up and down. |
| 66 | */ |
| 67 | #define HASWIDTH 01 /* Known never to match null string. */ |
| 68 | #define SIMPLE 02 /* Simple enough to be STAR/PLUS operand. */ |
| 69 | #define SPSTART 04 /* Starts with * or +. */ |
| 70 | #define WORST 0 /* Worst case. */ |
| 71 | |
| 72 | /* |
| 73 | * Global work variables for regcomp(). |
| 74 | */ |
| 75 | static char *regprecomp; /* uncompiled string. */ |
| 76 | static char *regparse; /* Input-scan pointer. */ |
| 77 | static char *regxend; /* End of input for compile */ |
| 78 | static int regnpar; /* () count. */ |
| 79 | static char *regcode; /* Code-emit pointer; ®dummy = don't. */ |
| 80 | static long regsize; /* Code size. */ |
| 81 | static int regfold; |
| 82 | static int regsawbracket; /* Did we do {d,d} trick? */ |
| 83 | |
| 84 | /* |
| 85 | * Forward declarations for regcomp()'s friends. |
| 86 | */ |
| 87 | STATIC int regcurly(); |
| 88 | STATIC char *reg(); |
| 89 | STATIC char *regbranch(); |
| 90 | STATIC char *regpiece(); |
| 91 | STATIC char *regatom(); |
| 92 | STATIC char *regclass(); |
| 93 | STATIC char *regnode(); |
| 94 | STATIC void regc(); |
| 95 | STATIC void reginsert(); |
| 96 | STATIC void regtail(); |
| 97 | STATIC void regoptail(); |
| 98 | |
| 99 | /* |
| 100 | - regcomp - compile a regular expression into internal code |
| 101 | * |
| 102 | * We can't allocate space until we know how big the compiled form will be, |
| 103 | * but we can't compile it (and thus know how big it is) until we've got a |
| 104 | * place to put the code. So we cheat: we compile it twice, once with code |
| 105 | * generation turned off and size counting turned on, and once "for real". |
| 106 | * This also means that we don't allocate space until we are sure that the |
| 107 | * thing really will compile successfully, and we never have to move the |
| 108 | * code and thus invalidate pointers into it. (Note that it has to be in |
| 109 | * one piece because free() must be able to free it all.) [NB: not true in perl] |
| 110 | * |
| 111 | * Beware that the optimization-preparation code in here knows about some |
| 112 | * of the structure of the compiled regexp. [I'll say.] |
| 113 | */ |
| 114 | regexp * |
| 115 | regcomp(exp,xend,fold,rare) |
| 116 | char *exp; |
| 117 | char *xend; |
| 118 | int fold; |
| 119 | int rare; |
| 120 | { |
| 121 | register regexp *r; |
| 122 | register char *scan; |
| 123 | register STR *longest; |
| 124 | register int len; |
| 125 | register char *first; |
| 126 | int flags; |
| 127 | int back; |
| 128 | int curback; |
| 129 | extern char *safemalloc(); |
| 130 | extern char *savestr(); |
| 131 | |
| 132 | if (exp == NULL) |
| 133 | fatal("NULL regexp argument"); |
| 134 | |
| 135 | /* First pass: determine size, legality. */ |
| 136 | regfold = fold; |
| 137 | regparse = exp; |
| 138 | regxend = xend; |
| 139 | regprecomp = nsavestr(exp,xend-exp); |
| 140 | regsawbracket = 0; |
| 141 | regnpar = 1; |
| 142 | regsize = 0L; |
| 143 | regcode = ®dummy; |
| 144 | regc(MAGIC); |
| 145 | if (reg(0, &flags) == NULL) { |
| 146 | Safefree(regprecomp); |
| 147 | return(NULL); |
| 148 | } |
| 149 | |
| 150 | /* Small enough for pointer-storage convention? */ |
| 151 | if (regsize >= 32767L) /* Probably could be 65535L. */ |
| 152 | FAIL("regexp too big"); |
| 153 | |
| 154 | /* Allocate space. */ |
| 155 | Newc(1001, r, sizeof(regexp) + (unsigned)regsize, char, regexp); |
| 156 | if (r == NULL) |
| 157 | FAIL("regexp out of space"); |
| 158 | |
| 159 | /* Second pass: emit code. */ |
| 160 | if (regsawbracket) |
| 161 | bcopy(regprecomp,exp,xend-exp); |
| 162 | r->precomp = regprecomp; |
| 163 | r->subbase = NULL; |
| 164 | regparse = exp; |
| 165 | regnpar = 1; |
| 166 | regcode = r->program; |
| 167 | regc(MAGIC); |
| 168 | if (reg(0, &flags) == NULL) |
| 169 | return(NULL); |
| 170 | |
| 171 | /* Dig out information for optimizations. */ |
| 172 | r->regstart = Nullstr; /* Worst-case defaults. */ |
| 173 | r->reganch = 0; |
| 174 | r->regmust = Nullstr; |
| 175 | r->regback = -1; |
| 176 | r->regstclass = Nullch; |
| 177 | scan = r->program+1; /* First BRANCH. */ |
| 178 | if (OP(regnext(scan)) == END) {/* Only one top-level choice. */ |
| 179 | scan = NEXTOPER(scan); |
| 180 | |
| 181 | first = scan; |
| 182 | while ((OP(first) > OPEN && OP(first) < CLOSE) || |
| 183 | (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) || |
| 184 | (OP(first) == PLUS) ) |
| 185 | first = NEXTOPER(first); |
| 186 | |
| 187 | /* Starting-point info. */ |
| 188 | if (OP(first) == EXACTLY) { |
| 189 | r->regstart = |
| 190 | str_make(OPERAND(first)+1,*OPERAND(first)); |
| 191 | if (r->regstart->str_cur > !(sawstudy|fold)) |
| 192 | fbmcompile(r->regstart,fold); |
| 193 | } |
| 194 | else if ((exp = index(simple,OP(first))) && exp > simple) |
| 195 | r->regstclass = first; |
| 196 | else if (OP(first) == BOUND || OP(first) == NBOUND) |
| 197 | r->regstclass = first; |
| 198 | else if (OP(first) == BOL) |
| 199 | r->reganch++; |
| 200 | |
| 201 | #ifdef DEBUGGING |
| 202 | if (debug & 512) |
| 203 | fprintf(stderr,"first %d next %d offset %d\n", |
| 204 | OP(first), OP(NEXTOPER(first)), first - scan); |
| 205 | #endif |
| 206 | /* |
| 207 | * If there's something expensive in the r.e., find the |
| 208 | * longest literal string that must appear and make it the |
| 209 | * regmust. Resolve ties in favor of later strings, since |
| 210 | * the regstart check works with the beginning of the r.e. |
| 211 | * and avoiding duplication strengthens checking. Not a |
| 212 | * strong reason, but sufficient in the absence of others. |
| 213 | * [Now we resolve ties in favor of the earlier string if |
| 214 | * it happens that curback has been invalidated, since the |
| 215 | * earlier string may buy us something the later one won't.] |
| 216 | */ |
| 217 | longest = str_make("",0); |
| 218 | len = 0; |
| 219 | curback = 0; |
| 220 | back = 0; |
| 221 | while (scan != NULL) { |
| 222 | if (OP(scan) == BRANCH) { |
| 223 | if (OP(regnext(scan)) == BRANCH) { |
| 224 | curback = -30000; |
| 225 | while (OP(scan) == BRANCH) |
| 226 | scan = regnext(scan); |
| 227 | } |
| 228 | else /* single branch is ok */ |
| 229 | scan = NEXTOPER(scan); |
| 230 | } |
| 231 | if (OP(scan) == EXACTLY) { |
| 232 | first = scan; |
| 233 | while (OP(regnext(scan)) >= CLOSE) |
| 234 | scan = regnext(scan); |
| 235 | if (curback - back == len) { |
| 236 | str_ncat(longest, OPERAND(first)+1, |
| 237 | *OPERAND(first)); |
| 238 | len += *OPERAND(first); |
| 239 | curback += *OPERAND(first); |
| 240 | first = regnext(scan); |
| 241 | } |
| 242 | else if (*OPERAND(first) >= len + (curback >= 0)) { |
| 243 | len = *OPERAND(first); |
| 244 | str_nset(longest, OPERAND(first)+1,len); |
| 245 | back = curback; |
| 246 | curback += len; |
| 247 | first = regnext(scan); |
| 248 | } |
| 249 | else |
| 250 | curback += *OPERAND(first); |
| 251 | } |
| 252 | else if (index(varies,OP(scan))) |
| 253 | curback = -30000; |
| 254 | else if (index(simple,OP(scan))) |
| 255 | curback++; |
| 256 | scan = regnext(scan); |
| 257 | } |
| 258 | if (len) { |
| 259 | r->regmust = longest; |
| 260 | if (back < 0) |
| 261 | back = -1; |
| 262 | r->regback = back; |
| 263 | if (len > !(sawstudy||fold||OP(first)==EOL)) |
| 264 | fbmcompile(r->regmust,fold); |
| 265 | r->regmust->str_u.str_useful = 100; |
| 266 | if (OP(first) == EOL) /* is match anchored to EOL? */ |
| 267 | r->regmust->str_pok |= SP_TAIL; |
| 268 | } |
| 269 | else |
| 270 | str_free(longest); |
| 271 | } |
| 272 | |
| 273 | r->do_folding = fold; |
| 274 | r->nparens = regnpar - 1; |
| 275 | #ifdef DEBUGGING |
| 276 | if (debug & 512) |
| 277 | regdump(r); |
| 278 | #endif |
| 279 | return(r); |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | - reg - regular expression, i.e. main body or parenthesized thing |
| 284 | * |
| 285 | * Caller must absorb opening parenthesis. |
| 286 | * |
| 287 | * Combining parenthesis handling with the base level of regular expression |
| 288 | * is a trifle forced, but the need to tie the tails of the branches to what |
| 289 | * follows makes it hard to avoid. |
| 290 | */ |
| 291 | static char * |
| 292 | reg(paren, flagp) |
| 293 | int paren; /* Parenthesized? */ |
| 294 | int *flagp; |
| 295 | { |
| 296 | register char *ret; |
| 297 | register char *br; |
| 298 | register char *ender; |
| 299 | register int parno; |
| 300 | int flags; |
| 301 | |
| 302 | *flagp = HASWIDTH; /* Tentatively. */ |
| 303 | |
| 304 | /* Make an OPEN node, if parenthesized. */ |
| 305 | if (paren) { |
| 306 | if (regnpar >= NSUBEXP) |
| 307 | FAIL("too many () in regexp"); |
| 308 | parno = regnpar; |
| 309 | regnpar++; |
| 310 | ret = regnode(OPEN+parno); |
| 311 | } else |
| 312 | ret = NULL; |
| 313 | |
| 314 | /* Pick up the branches, linking them together. */ |
| 315 | br = regbranch(&flags); |
| 316 | if (br == NULL) |
| 317 | return(NULL); |
| 318 | if (ret != NULL) |
| 319 | regtail(ret, br); /* OPEN -> first. */ |
| 320 | else |
| 321 | ret = br; |
| 322 | if (!(flags&HASWIDTH)) |
| 323 | *flagp &= ~HASWIDTH; |
| 324 | *flagp |= flags&SPSTART; |
| 325 | while (*regparse == '|') { |
| 326 | regparse++; |
| 327 | br = regbranch(&flags); |
| 328 | if (br == NULL) |
| 329 | return(NULL); |
| 330 | regtail(ret, br); /* BRANCH -> BRANCH. */ |
| 331 | if (!(flags&HASWIDTH)) |
| 332 | *flagp &= ~HASWIDTH; |
| 333 | *flagp |= flags&SPSTART; |
| 334 | } |
| 335 | |
| 336 | /* Make a closing node, and hook it on the end. */ |
| 337 | ender = regnode((paren) ? CLOSE+parno : END); |
| 338 | regtail(ret, ender); |
| 339 | |
| 340 | /* Hook the tails of the branches to the closing node. */ |
| 341 | for (br = ret; br != NULL; br = regnext(br)) |
| 342 | regoptail(br, ender); |
| 343 | |
| 344 | /* Check for proper termination. */ |
| 345 | if (paren && *regparse++ != ')') { |
| 346 | FAIL("unmatched () in regexp"); |
| 347 | } else if (!paren && regparse < regxend) { |
| 348 | if (*regparse == ')') { |
| 349 | FAIL("unmatched () in regexp"); |
| 350 | } else |
| 351 | FAIL("junk on end of regexp"); /* "Can't happen". */ |
| 352 | /* NOTREACHED */ |
| 353 | } |
| 354 | |
| 355 | return(ret); |
| 356 | } |
| 357 | |
| 358 | /* |
| 359 | - regbranch - one alternative of an | operator |
| 360 | * |
| 361 | * Implements the concatenation operator. |
| 362 | */ |
| 363 | static char * |
| 364 | regbranch(flagp) |
| 365 | int *flagp; |
| 366 | { |
| 367 | register char *ret; |
| 368 | register char *chain; |
| 369 | register char *latest; |
| 370 | int flags; |
| 371 | |
| 372 | *flagp = WORST; /* Tentatively. */ |
| 373 | |
| 374 | ret = regnode(BRANCH); |
| 375 | chain = NULL; |
| 376 | while (regparse < regxend && *regparse != '|' && *regparse != ')') { |
| 377 | latest = regpiece(&flags); |
| 378 | if (latest == NULL) |
| 379 | return(NULL); |
| 380 | *flagp |= flags&HASWIDTH; |
| 381 | if (chain == NULL) /* First piece. */ |
| 382 | *flagp |= flags&SPSTART; |
| 383 | else |
| 384 | regtail(chain, latest); |
| 385 | chain = latest; |
| 386 | } |
| 387 | if (chain == NULL) /* Loop ran zero times. */ |
| 388 | (void) regnode(NOTHING); |
| 389 | |
| 390 | return(ret); |
| 391 | } |
| 392 | |
| 393 | /* |
| 394 | - regpiece - something followed by possible [*+?] |
| 395 | * |
| 396 | * Note that the branching code sequences used for ? and the general cases |
| 397 | * of * and + are somewhat optimized: they use the same NOTHING node as |
| 398 | * both the endmarker for their branch list and the body of the last branch. |
| 399 | * It might seem that this node could be dispensed with entirely, but the |
| 400 | * endmarker role is not redundant. |
| 401 | */ |
| 402 | static char * |
| 403 | regpiece(flagp) |
| 404 | int *flagp; |
| 405 | { |
| 406 | register char *ret; |
| 407 | register char op; |
| 408 | register char *next; |
| 409 | int flags; |
| 410 | char *origparse = regparse; |
| 411 | int orignpar = regnpar; |
| 412 | char *max; |
| 413 | int iter; |
| 414 | char ch; |
| 415 | |
| 416 | ret = regatom(&flags); |
| 417 | if (ret == NULL) |
| 418 | return(NULL); |
| 419 | |
| 420 | op = *regparse; |
| 421 | |
| 422 | /* Here's a total kludge: if after the atom there's a {\d+,?\d*} |
| 423 | * then we decrement the first number by one and reset our |
| 424 | * parsing back to the beginning of the same atom. If the first number |
| 425 | * is down to 0, decrement the second number instead and fake up |
| 426 | * a ? after it. Given the way this compiler doesn't keep track |
| 427 | * of offsets on the first pass, this is the only way to replicate |
| 428 | * a piece of code. Sigh. |
| 429 | */ |
| 430 | if (op == '{' && regcurly(regparse)) { |
| 431 | next = regparse + 1; |
| 432 | max = Nullch; |
| 433 | while (isdigit(*next) || *next == ',') { |
| 434 | if (*next == ',') { |
| 435 | if (max) |
| 436 | break; |
| 437 | else |
| 438 | max = next; |
| 439 | } |
| 440 | next++; |
| 441 | } |
| 442 | if (*next == '}') { /* got one */ |
| 443 | regsawbracket++; /* remember we clobbered exp */ |
| 444 | if (!max) |
| 445 | max = next; |
| 446 | regparse++; |
| 447 | iter = atoi(regparse); |
| 448 | if (iter > 0) { |
| 449 | ch = *max; |
| 450 | sprintf(regparse,"%.*d", max-regparse, iter - 1); |
| 451 | *max = ch; |
| 452 | if (*max == ',' && atoi(max+1) > 0) { |
| 453 | ch = *next; |
| 454 | sprintf(max+1,"%.*d", next-(max+1), atoi(max+1) - 1); |
| 455 | *next = ch; |
| 456 | } |
| 457 | if (iter != 1 || (*max == ',' || atoi(max+1))) { |
| 458 | regparse = origparse; /* back up input pointer */ |
| 459 | regnpar = orignpar; /* don't make more parens */ |
| 460 | } |
| 461 | else { |
| 462 | regparse = next; |
| 463 | goto nest_check; |
| 464 | } |
| 465 | *flagp = flags; |
| 466 | return ret; |
| 467 | } |
| 468 | if (*max == ',') { |
| 469 | max++; |
| 470 | iter = atoi(max); |
| 471 | if (max == next) { /* any number more? */ |
| 472 | regparse = next; |
| 473 | op = '*'; /* fake up one with a star */ |
| 474 | } |
| 475 | else if (iter > 0) { |
| 476 | op = '?'; /* fake up optional atom */ |
| 477 | ch = *next; |
| 478 | sprintf(max,"%.*d", next-max, iter - 1); |
| 479 | *next = ch; |
| 480 | if (iter == 1) |
| 481 | regparse = next; |
| 482 | else { |
| 483 | regparse = origparse - 1; /* offset ++ below */ |
| 484 | regnpar = orignpar; |
| 485 | } |
| 486 | } |
| 487 | else |
| 488 | fatal("Can't do {n,0}"); |
| 489 | } |
| 490 | else |
| 491 | fatal("Can't do {0}"); |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | if (!ISMULT1(op)) { |
| 496 | *flagp = flags; |
| 497 | return(ret); |
| 498 | } |
| 499 | |
| 500 | if (!(flags&HASWIDTH) && op != '?') |
| 501 | FAIL("regexp *+ operand could be empty"); |
| 502 | *flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH); |
| 503 | |
| 504 | if (op == '*' && (flags&SIMPLE)) |
| 505 | reginsert(STAR, ret); |
| 506 | else if (op == '*') { |
| 507 | /* Emit x* as (x&|), where & means "self". */ |
| 508 | reginsert(BRANCH, ret); /* Either x */ |
| 509 | regoptail(ret, regnode(BACK)); /* and loop */ |
| 510 | regoptail(ret, ret); /* back */ |
| 511 | regtail(ret, regnode(BRANCH)); /* or */ |
| 512 | regtail(ret, regnode(NOTHING)); /* null. */ |
| 513 | } else if (op == '+' && (flags&SIMPLE)) |
| 514 | reginsert(PLUS, ret); |
| 515 | else if (op == '+') { |
| 516 | /* Emit x+ as x(&|), where & means "self". */ |
| 517 | next = regnode(BRANCH); /* Either */ |
| 518 | regtail(ret, next); |
| 519 | regtail(regnode(BACK), ret); /* loop back */ |
| 520 | regtail(next, regnode(BRANCH)); /* or */ |
| 521 | regtail(ret, regnode(NOTHING)); /* null. */ |
| 522 | } else if (op == '?') { |
| 523 | /* Emit x? as (x|) */ |
| 524 | reginsert(BRANCH, ret); /* Either x */ |
| 525 | regtail(ret, regnode(BRANCH)); /* or */ |
| 526 | next = regnode(NOTHING); /* null. */ |
| 527 | regtail(ret, next); |
| 528 | regoptail(ret, next); |
| 529 | } |
| 530 | nest_check: |
| 531 | regparse++; |
| 532 | if (ISMULT2(regparse)) |
| 533 | FAIL("nested *?+ in regexp"); |
| 534 | |
| 535 | return(ret); |
| 536 | } |
| 537 | |
| 538 | /* |
| 539 | - regatom - the lowest level |
| 540 | * |
| 541 | * Optimization: gobbles an entire sequence of ordinary characters so that |
| 542 | * it can turn them into a single node, which is smaller to store and |
| 543 | * faster to run. Backslashed characters are exceptions, each becoming a |
| 544 | * separate node; the code is simpler that way and it's not worth fixing. |
| 545 | * |
| 546 | * [Yes, it is worth fixing, some scripts can run twice the speed.] |
| 547 | */ |
| 548 | static char * |
| 549 | regatom(flagp) |
| 550 | int *flagp; |
| 551 | { |
| 552 | register char *ret; |
| 553 | int flags; |
| 554 | |
| 555 | *flagp = WORST; /* Tentatively. */ |
| 556 | |
| 557 | switch (*regparse++) { |
| 558 | case '^': |
| 559 | ret = regnode(BOL); |
| 560 | break; |
| 561 | case '$': |
| 562 | ret = regnode(EOL); |
| 563 | break; |
| 564 | case '.': |
| 565 | ret = regnode(ANY); |
| 566 | *flagp |= HASWIDTH|SIMPLE; |
| 567 | break; |
| 568 | case '[': |
| 569 | ret = regclass(); |
| 570 | *flagp |= HASWIDTH|SIMPLE; |
| 571 | break; |
| 572 | case '(': |
| 573 | ret = reg(1, &flags); |
| 574 | if (ret == NULL) |
| 575 | return(NULL); |
| 576 | *flagp |= flags&(HASWIDTH|SPSTART); |
| 577 | break; |
| 578 | case '|': |
| 579 | case ')': |
| 580 | FAIL("internal urp in regexp"); /* Supposed to be caught earlier. */ |
| 581 | break; |
| 582 | case '?': |
| 583 | case '+': |
| 584 | case '*': |
| 585 | FAIL("?+* follows nothing in regexp"); |
| 586 | break; |
| 587 | case '\\': |
| 588 | switch (*regparse) { |
| 589 | case 'w': |
| 590 | ret = regnode(ALNUM); |
| 591 | *flagp |= HASWIDTH|SIMPLE; |
| 592 | regparse++; |
| 593 | break; |
| 594 | case 'W': |
| 595 | ret = regnode(NALNUM); |
| 596 | *flagp |= HASWIDTH|SIMPLE; |
| 597 | regparse++; |
| 598 | break; |
| 599 | case 'b': |
| 600 | ret = regnode(BOUND); |
| 601 | *flagp |= SIMPLE; |
| 602 | regparse++; |
| 603 | break; |
| 604 | case 'B': |
| 605 | ret = regnode(NBOUND); |
| 606 | *flagp |= SIMPLE; |
| 607 | regparse++; |
| 608 | break; |
| 609 | case 's': |
| 610 | ret = regnode(SPACE); |
| 611 | *flagp |= HASWIDTH|SIMPLE; |
| 612 | regparse++; |
| 613 | break; |
| 614 | case 'S': |
| 615 | ret = regnode(NSPACE); |
| 616 | *flagp |= HASWIDTH|SIMPLE; |
| 617 | regparse++; |
| 618 | break; |
| 619 | case 'd': |
| 620 | ret = regnode(DIGIT); |
| 621 | *flagp |= HASWIDTH|SIMPLE; |
| 622 | regparse++; |
| 623 | break; |
| 624 | case 'D': |
| 625 | ret = regnode(NDIGIT); |
| 626 | *flagp |= HASWIDTH|SIMPLE; |
| 627 | regparse++; |
| 628 | break; |
| 629 | case 'n': |
| 630 | case 'r': |
| 631 | case 't': |
| 632 | case 'f': |
| 633 | goto defchar; |
| 634 | case '0': case '1': case '2': case '3': case '4': |
| 635 | case '5': case '6': case '7': case '8': case '9': |
| 636 | if (isdigit(regparse[1])) |
| 637 | goto defchar; |
| 638 | else { |
| 639 | ret = regnode(REF + *regparse++ - '0'); |
| 640 | *flagp |= SIMPLE; |
| 641 | } |
| 642 | break; |
| 643 | case '\0': |
| 644 | if (regparse >= regxend) |
| 645 | FAIL("trailing \\ in regexp"); |
| 646 | /* FALL THROUGH */ |
| 647 | default: |
| 648 | goto defchar; |
| 649 | } |
| 650 | break; |
| 651 | default: { |
| 652 | register int len; |
| 653 | register char ender; |
| 654 | register char *p; |
| 655 | char *oldp; |
| 656 | int foo; |
| 657 | |
| 658 | defchar: |
| 659 | ret = regnode(EXACTLY); |
| 660 | regc(0); /* save spot for len */ |
| 661 | for (len=0, p=regparse-1; |
| 662 | len < 127 && p < regxend; |
| 663 | len++) |
| 664 | { |
| 665 | oldp = p; |
| 666 | switch (*p) { |
| 667 | case '^': |
| 668 | case '$': |
| 669 | case '.': |
| 670 | case '[': |
| 671 | case '(': |
| 672 | case ')': |
| 673 | case '|': |
| 674 | goto loopdone; |
| 675 | case '\\': |
| 676 | switch (*++p) { |
| 677 | case 'w': |
| 678 | case 'W': |
| 679 | case 'b': |
| 680 | case 'B': |
| 681 | case 's': |
| 682 | case 'S': |
| 683 | case 'd': |
| 684 | case 'D': |
| 685 | --p; |
| 686 | goto loopdone; |
| 687 | case 'n': |
| 688 | ender = '\n'; |
| 689 | p++; |
| 690 | break; |
| 691 | case 'r': |
| 692 | ender = '\r'; |
| 693 | p++; |
| 694 | break; |
| 695 | case 't': |
| 696 | ender = '\t'; |
| 697 | p++; |
| 698 | break; |
| 699 | case 'f': |
| 700 | ender = '\f'; |
| 701 | p++; |
| 702 | break; |
| 703 | case '0': case '1': case '2': case '3':case '4': |
| 704 | case '5': case '6': case '7': case '8':case '9': |
| 705 | if (isdigit(p[1])) { |
| 706 | foo = *p++ - '0'; |
| 707 | foo <<= 3; |
| 708 | foo += *p - '0'; |
| 709 | if (isdigit(p[1])) |
| 710 | foo = (foo<<3) + *++p - '0'; |
| 711 | ender = foo; |
| 712 | p++; |
| 713 | } |
| 714 | else { |
| 715 | --p; |
| 716 | goto loopdone; |
| 717 | } |
| 718 | break; |
| 719 | case '\0': |
| 720 | if (p >= regxend) |
| 721 | FAIL("trailing \\ in regexp"); |
| 722 | /* FALL THROUGH */ |
| 723 | default: |
| 724 | ender = *p++; |
| 725 | break; |
| 726 | } |
| 727 | break; |
| 728 | default: |
| 729 | ender = *p++; |
| 730 | break; |
| 731 | } |
| 732 | if (regfold && isupper(ender)) |
| 733 | ender = tolower(ender); |
| 734 | if (ISMULT2(p)) { /* Back off on ?+*. */ |
| 735 | if (len) |
| 736 | p = oldp; |
| 737 | else { |
| 738 | len++; |
| 739 | regc(ender); |
| 740 | } |
| 741 | break; |
| 742 | } |
| 743 | regc(ender); |
| 744 | } |
| 745 | loopdone: |
| 746 | regparse = p; |
| 747 | if (len <= 0) |
| 748 | FAIL("internal disaster in regexp"); |
| 749 | *flagp |= HASWIDTH; |
| 750 | if (len == 1) |
| 751 | *flagp |= SIMPLE; |
| 752 | if (regcode != ®dummy) |
| 753 | *OPERAND(ret) = len; |
| 754 | regc('\0'); |
| 755 | } |
| 756 | break; |
| 757 | } |
| 758 | |
| 759 | return(ret); |
| 760 | } |
| 761 | |
| 762 | static void |
| 763 | regset(bits,def,c) |
| 764 | char *bits; |
| 765 | int def; |
| 766 | register int c; |
| 767 | { |
| 768 | if (regcode == ®dummy) |
| 769 | return; |
| 770 | if (def) |
| 771 | bits[c >> 3] &= ~(1 << (c & 7)); |
| 772 | else |
| 773 | bits[c >> 3] |= (1 << (c & 7)); |
| 774 | } |
| 775 | |
| 776 | static char * |
| 777 | regclass() |
| 778 | { |
| 779 | register char *bits; |
| 780 | register int class; |
| 781 | register int lastclass; |
| 782 | register int range = 0; |
| 783 | register char *ret; |
| 784 | register int def; |
| 785 | |
| 786 | if (*regparse == '^') { /* Complement of range. */ |
| 787 | ret = regnode(ANYBUT); |
| 788 | regparse++; |
| 789 | def = 0; |
| 790 | } else { |
| 791 | ret = regnode(ANYOF); |
| 792 | def = 255; |
| 793 | } |
| 794 | bits = regcode; |
| 795 | for (class = 0; class < 32; class++) |
| 796 | regc(def); |
| 797 | if (*regparse == ']' || *regparse == '-') |
| 798 | regset(bits,def,lastclass = *regparse++); |
| 799 | while (regparse < regxend && *regparse != ']') { |
| 800 | class = UCHARAT(regparse++); |
| 801 | if (class == '\\') { |
| 802 | class = UCHARAT(regparse++); |
| 803 | switch (class) { |
| 804 | case 'w': |
| 805 | for (class = 'a'; class <= 'z'; class++) |
| 806 | regset(bits,def,class); |
| 807 | for (class = 'A'; class <= 'Z'; class++) |
| 808 | regset(bits,def,class); |
| 809 | for (class = '0'; class <= '9'; class++) |
| 810 | regset(bits,def,class); |
| 811 | regset(bits,def,'_'); |
| 812 | lastclass = 1234; |
| 813 | continue; |
| 814 | case 's': |
| 815 | regset(bits,def,' '); |
| 816 | regset(bits,def,'\t'); |
| 817 | regset(bits,def,'\r'); |
| 818 | regset(bits,def,'\f'); |
| 819 | regset(bits,def,'\n'); |
| 820 | lastclass = 1234; |
| 821 | continue; |
| 822 | case 'd': |
| 823 | for (class = '0'; class <= '9'; class++) |
| 824 | regset(bits,def,class); |
| 825 | lastclass = 1234; |
| 826 | continue; |
| 827 | case 'n': |
| 828 | class = '\n'; |
| 829 | break; |
| 830 | case 'r': |
| 831 | class = '\r'; |
| 832 | break; |
| 833 | case 't': |
| 834 | class = '\t'; |
| 835 | break; |
| 836 | case 'f': |
| 837 | class = '\f'; |
| 838 | break; |
| 839 | case 'b': |
| 840 | class = '\b'; |
| 841 | break; |
| 842 | case '0': case '1': case '2': case '3': case '4': |
| 843 | case '5': case '6': case '7': case '8': case '9': |
| 844 | class -= '0'; |
| 845 | if (isdigit(*regparse)) { |
| 846 | class <<= 3; |
| 847 | class += *regparse++ - '0'; |
| 848 | } |
| 849 | if (isdigit(*regparse)) { |
| 850 | class <<= 3; |
| 851 | class += *regparse++ - '0'; |
| 852 | } |
| 853 | break; |
| 854 | } |
| 855 | } |
| 856 | if (!range && class == '-' && regparse < regxend && |
| 857 | *regparse != ']') { |
| 858 | range = 1; |
| 859 | continue; |
| 860 | } |
| 861 | if (range) { |
| 862 | if (lastclass > class) |
| 863 | FAIL("invalid [] range in regexp"); |
| 864 | } |
| 865 | else |
| 866 | lastclass = class - 1; |
| 867 | range = 0; |
| 868 | for (lastclass++; lastclass <= class; lastclass++) { |
| 869 | regset(bits,def,lastclass); |
| 870 | if (regfold && isupper(lastclass)) |
| 871 | regset(bits,def,tolower(lastclass)); |
| 872 | } |
| 873 | lastclass = class; |
| 874 | } |
| 875 | if (*regparse != ']') |
| 876 | FAIL("unmatched [] in regexp"); |
| 877 | regset(bits,0,0); /* always bomb out on null */ |
| 878 | regparse++; |
| 879 | return ret; |
| 880 | } |
| 881 | |
| 882 | /* |
| 883 | - regnode - emit a node |
| 884 | */ |
| 885 | static char * /* Location. */ |
| 886 | regnode(op) |
| 887 | char op; |
| 888 | { |
| 889 | register char *ret; |
| 890 | register char *ptr; |
| 891 | |
| 892 | ret = regcode; |
| 893 | if (ret == ®dummy) { |
| 894 | #ifdef REGALIGN |
| 895 | if (!(regsize & 1)) |
| 896 | regsize++; |
| 897 | #endif |
| 898 | regsize += 3; |
| 899 | return(ret); |
| 900 | } |
| 901 | |
| 902 | #ifdef REGALIGN |
| 903 | #ifndef lint |
| 904 | if (!((long)ret & 1)) |
| 905 | *ret++ = 127; |
| 906 | #endif |
| 907 | #endif |
| 908 | ptr = ret; |
| 909 | *ptr++ = op; |
| 910 | *ptr++ = '\0'; /* Null "next" pointer. */ |
| 911 | *ptr++ = '\0'; |
| 912 | regcode = ptr; |
| 913 | |
| 914 | return(ret); |
| 915 | } |
| 916 | |
| 917 | /* |
| 918 | - regc - emit (if appropriate) a byte of code |
| 919 | */ |
| 920 | static void |
| 921 | regc(b) |
| 922 | char b; |
| 923 | { |
| 924 | if (regcode != ®dummy) |
| 925 | *regcode++ = b; |
| 926 | else |
| 927 | regsize++; |
| 928 | } |
| 929 | |
| 930 | /* |
| 931 | - reginsert - insert an operator in front of already-emitted operand |
| 932 | * |
| 933 | * Means relocating the operand. |
| 934 | */ |
| 935 | static void |
| 936 | reginsert(op, opnd) |
| 937 | char op; |
| 938 | char *opnd; |
| 939 | { |
| 940 | register char *src; |
| 941 | register char *dst; |
| 942 | register char *place; |
| 943 | |
| 944 | if (regcode == ®dummy) { |
| 945 | #ifdef REGALIGN |
| 946 | regsize += 4; |
| 947 | #else |
| 948 | regsize += 3; |
| 949 | #endif |
| 950 | return; |
| 951 | } |
| 952 | |
| 953 | src = regcode; |
| 954 | #ifdef REGALIGN |
| 955 | regcode += 4; |
| 956 | #else |
| 957 | regcode += 3; |
| 958 | #endif |
| 959 | dst = regcode; |
| 960 | while (src > opnd) |
| 961 | *--dst = *--src; |
| 962 | |
| 963 | place = opnd; /* Op node, where operand used to be. */ |
| 964 | *place++ = op; |
| 965 | *place++ = '\0'; |
| 966 | *place++ = '\0'; |
| 967 | } |
| 968 | |
| 969 | /* |
| 970 | - regtail - set the next-pointer at the end of a node chain |
| 971 | */ |
| 972 | static void |
| 973 | regtail(p, val) |
| 974 | char *p; |
| 975 | char *val; |
| 976 | { |
| 977 | register char *scan; |
| 978 | register char *temp; |
| 979 | register int offset; |
| 980 | |
| 981 | if (p == ®dummy) |
| 982 | return; |
| 983 | |
| 984 | /* Find last node. */ |
| 985 | scan = p; |
| 986 | for (;;) { |
| 987 | temp = regnext(scan); |
| 988 | if (temp == NULL) |
| 989 | break; |
| 990 | scan = temp; |
| 991 | } |
| 992 | |
| 993 | #ifdef REGALIGN |
| 994 | offset = val - scan; |
| 995 | #ifndef lint |
| 996 | *(short*)(scan+1) = offset; |
| 997 | #else |
| 998 | offset = offset; |
| 999 | #endif |
| 1000 | #else |
| 1001 | if (OP(scan) == BACK) |
| 1002 | offset = scan - val; |
| 1003 | else |
| 1004 | offset = val - scan; |
| 1005 | *(scan+1) = (offset>>8)&0377; |
| 1006 | *(scan+2) = offset&0377; |
| 1007 | #endif |
| 1008 | } |
| 1009 | |
| 1010 | /* |
| 1011 | - regoptail - regtail on operand of first argument; nop if operandless |
| 1012 | */ |
| 1013 | static void |
| 1014 | regoptail(p, val) |
| 1015 | char *p; |
| 1016 | char *val; |
| 1017 | { |
| 1018 | /* "Operandless" and "op != BRANCH" are synonymous in practice. */ |
| 1019 | if (p == NULL || p == ®dummy || OP(p) != BRANCH) |
| 1020 | return; |
| 1021 | regtail(NEXTOPER(p), val); |
| 1022 | } |
| 1023 | |
| 1024 | /* |
| 1025 | - regcurly - a little FSA that accepts {\d+,?\d*} |
| 1026 | */ |
| 1027 | STATIC int |
| 1028 | regcurly(s) |
| 1029 | register char *s; |
| 1030 | { |
| 1031 | if (*s++ != '{') |
| 1032 | return FALSE; |
| 1033 | if (!isdigit(*s)) |
| 1034 | return FALSE; |
| 1035 | while (isdigit(*s)) |
| 1036 | s++; |
| 1037 | if (*s == ',') |
| 1038 | s++; |
| 1039 | while (isdigit(*s)) |
| 1040 | s++; |
| 1041 | if (*s != '}') |
| 1042 | return FALSE; |
| 1043 | return TRUE; |
| 1044 | } |
| 1045 | |
| 1046 | #ifdef DEBUGGING |
| 1047 | |
| 1048 | /* |
| 1049 | - regdump - dump a regexp onto stderr in vaguely comprehensible form |
| 1050 | */ |
| 1051 | void |
| 1052 | regdump(r) |
| 1053 | regexp *r; |
| 1054 | { |
| 1055 | register char *s; |
| 1056 | register char op = EXACTLY; /* Arbitrary non-END op. */ |
| 1057 | register char *next; |
| 1058 | extern char *index(); |
| 1059 | |
| 1060 | |
| 1061 | s = r->program + 1; |
| 1062 | while (op != END) { /* While that wasn't END last time... */ |
| 1063 | #ifdef REGALIGN |
| 1064 | if (!((long)s & 1)) |
| 1065 | s++; |
| 1066 | #endif |
| 1067 | op = OP(s); |
| 1068 | fprintf(stderr,"%2d%s", s-r->program, regprop(s)); /* Where, what. */ |
| 1069 | next = regnext(s); |
| 1070 | if (next == NULL) /* Next ptr. */ |
| 1071 | fprintf(stderr,"(0)"); |
| 1072 | else |
| 1073 | fprintf(stderr,"(%d)", (s-r->program)+(next-s)); |
| 1074 | s += 3; |
| 1075 | if (op == ANYOF || op == ANYBUT) { |
| 1076 | s += 32; |
| 1077 | } |
| 1078 | if (op == EXACTLY) { |
| 1079 | /* Literal string, where present. */ |
| 1080 | s++; |
| 1081 | while (*s != '\0') { |
| 1082 | (void)putchar(*s); |
| 1083 | s++; |
| 1084 | } |
| 1085 | s++; |
| 1086 | } |
| 1087 | (void)putchar('\n'); |
| 1088 | } |
| 1089 | |
| 1090 | /* Header fields of interest. */ |
| 1091 | if (r->regstart) |
| 1092 | fprintf(stderr,"start `%s' ", r->regstart->str_ptr); |
| 1093 | if (r->regstclass) |
| 1094 | fprintf(stderr,"stclass `%s' ", regprop(r->regstclass)); |
| 1095 | if (r->reganch) |
| 1096 | fprintf(stderr,"anchored "); |
| 1097 | if (r->regmust != NULL) |
| 1098 | fprintf(stderr,"must have \"%s\" back %d ", r->regmust->str_ptr, |
| 1099 | r->regback); |
| 1100 | fprintf(stderr,"\n"); |
| 1101 | } |
| 1102 | |
| 1103 | /* |
| 1104 | - regprop - printable representation of opcode |
| 1105 | */ |
| 1106 | char * |
| 1107 | regprop(op) |
| 1108 | char *op; |
| 1109 | { |
| 1110 | register char *p; |
| 1111 | |
| 1112 | (void) strcpy(buf, ":"); |
| 1113 | |
| 1114 | switch (OP(op)) { |
| 1115 | case BOL: |
| 1116 | p = "BOL"; |
| 1117 | break; |
| 1118 | case EOL: |
| 1119 | p = "EOL"; |
| 1120 | break; |
| 1121 | case ANY: |
| 1122 | p = "ANY"; |
| 1123 | break; |
| 1124 | case ANYOF: |
| 1125 | p = "ANYOF"; |
| 1126 | break; |
| 1127 | case ANYBUT: |
| 1128 | p = "ANYBUT"; |
| 1129 | break; |
| 1130 | case BRANCH: |
| 1131 | p = "BRANCH"; |
| 1132 | break; |
| 1133 | case EXACTLY: |
| 1134 | p = "EXACTLY"; |
| 1135 | break; |
| 1136 | case NOTHING: |
| 1137 | p = "NOTHING"; |
| 1138 | break; |
| 1139 | case BACK: |
| 1140 | p = "BACK"; |
| 1141 | break; |
| 1142 | case END: |
| 1143 | p = "END"; |
| 1144 | break; |
| 1145 | case ALNUM: |
| 1146 | p = "ALNUM"; |
| 1147 | break; |
| 1148 | case NALNUM: |
| 1149 | p = "NALNUM"; |
| 1150 | break; |
| 1151 | case BOUND: |
| 1152 | p = "BOUND"; |
| 1153 | break; |
| 1154 | case NBOUND: |
| 1155 | p = "NBOUND"; |
| 1156 | break; |
| 1157 | case SPACE: |
| 1158 | p = "SPACE"; |
| 1159 | break; |
| 1160 | case NSPACE: |
| 1161 | p = "NSPACE"; |
| 1162 | break; |
| 1163 | case DIGIT: |
| 1164 | p = "DIGIT"; |
| 1165 | break; |
| 1166 | case NDIGIT: |
| 1167 | p = "NDIGIT"; |
| 1168 | break; |
| 1169 | case REF: |
| 1170 | case REF+1: |
| 1171 | case REF+2: |
| 1172 | case REF+3: |
| 1173 | case REF+4: |
| 1174 | case REF+5: |
| 1175 | case REF+6: |
| 1176 | case REF+7: |
| 1177 | case REF+8: |
| 1178 | case REF+9: |
| 1179 | (void)sprintf(buf+strlen(buf), "REF%d", OP(op)-REF); |
| 1180 | p = NULL; |
| 1181 | break; |
| 1182 | case OPEN+1: |
| 1183 | case OPEN+2: |
| 1184 | case OPEN+3: |
| 1185 | case OPEN+4: |
| 1186 | case OPEN+5: |
| 1187 | case OPEN+6: |
| 1188 | case OPEN+7: |
| 1189 | case OPEN+8: |
| 1190 | case OPEN+9: |
| 1191 | (void)sprintf(buf+strlen(buf), "OPEN%d", OP(op)-OPEN); |
| 1192 | p = NULL; |
| 1193 | break; |
| 1194 | case CLOSE+1: |
| 1195 | case CLOSE+2: |
| 1196 | case CLOSE+3: |
| 1197 | case CLOSE+4: |
| 1198 | case CLOSE+5: |
| 1199 | case CLOSE+6: |
| 1200 | case CLOSE+7: |
| 1201 | case CLOSE+8: |
| 1202 | case CLOSE+9: |
| 1203 | (void)sprintf(buf+strlen(buf), "CLOSE%d", OP(op)-CLOSE); |
| 1204 | p = NULL; |
| 1205 | break; |
| 1206 | case STAR: |
| 1207 | p = "STAR"; |
| 1208 | break; |
| 1209 | case PLUS: |
| 1210 | p = "PLUS"; |
| 1211 | break; |
| 1212 | default: |
| 1213 | FAIL("corrupted regexp opcode"); |
| 1214 | } |
| 1215 | if (p != NULL) |
| 1216 | (void) strcat(buf, p); |
| 1217 | return(buf); |
| 1218 | } |
| 1219 | #endif /* DEBUGGING */ |
| 1220 | |
| 1221 | regfree(r) |
| 1222 | struct regexp *r; |
| 1223 | { |
| 1224 | if (r->precomp) |
| 1225 | Safefree(r->precomp); |
| 1226 | if (r->subbase) |
| 1227 | Safefree(r->subbase); |
| 1228 | if (r->regmust) |
| 1229 | str_free(r->regmust); |
| 1230 | if (r->regstart) |
| 1231 | str_free(r->regstart); |
| 1232 | Safefree(r); |
| 1233 | } |