xref: /openbsd/usr.bin/awk/b.c (revision b39c5158)
1 /*	$OpenBSD: b.c,v 1.16 2010/06/13 17:58:19 millert Exp $	*/
2 /****************************************************************
3 Copyright (C) Lucent Technologies 1997
4 All Rights Reserved
5 
6 Permission to use, copy, modify, and distribute this software and
7 its documentation for any purpose and without fee is hereby
8 granted, provided that the above copyright notice appear in all
9 copies and that both that the copyright notice and this
10 permission notice and warranty disclaimer appear in supporting
11 documentation, and that the name Lucent Technologies or any of
12 its entities not be used in advertising or publicity pertaining
13 to distribution of the software without specific, written prior
14 permission.
15 
16 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
17 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
18 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
19 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
20 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
21 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
22 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
23 THIS SOFTWARE.
24 ****************************************************************/
25 
26 /* lasciate ogne speranza, voi ch'intrate. */
27 
28 #define	DEBUG
29 
30 #include <ctype.h>
31 #include <stdio.h>
32 #include <string.h>
33 #include <stdlib.h>
34 #include "awk.h"
35 #include "ytab.h"
36 
37 #define	HAT	(NCHARS+2)	/* matches ^ in regular expr */
38 				/* NCHARS is 2**n */
39 #define MAXLIN 22
40 
41 #define type(v)		(v)->nobj	/* badly overloaded here */
42 #define info(v)		(v)->ntype	/* badly overloaded here */
43 #define left(v)		(v)->narg[0]
44 #define right(v)	(v)->narg[1]
45 #define parent(v)	(v)->nnext
46 
47 #define LEAF	case CCL: case NCCL: case CHAR: case DOT: case FINAL: case ALL:
48 #define ELEAF	case EMPTYRE:		/* empty string in regexp */
49 #define UNARY	case STAR: case PLUS: case QUEST:
50 
51 /* encoding in tree Nodes:
52 	leaf (CCL, NCCL, CHAR, DOT, FINAL, ALL, EMPTYRE):
53 		left is index, right contains value or pointer to value
54 	unary (STAR, PLUS, QUEST): left is child, right is null
55 	binary (CAT, OR): left and right are children
56 	parent contains pointer to parent
57 */
58 
59 
60 int	*setvec;
61 int	*tmpset;
62 int	maxsetvec = 0;
63 
64 int	rtok;		/* next token in current re */
65 int	rlxval;
66 static uschar	*rlxstr;
67 static uschar	*prestr;	/* current position in current re */
68 static uschar	*lastre;	/* origin of last re */
69 
70 static	int setcnt;
71 static	int poscnt;
72 
73 char	*patbeg;
74 int	patlen;
75 
76 #define	NFA	20	/* cache this many dynamic fa's */
77 fa	*fatab[NFA];
78 int	nfatab	= 0;	/* entries in fatab */
79 
80 fa *makedfa(const char *s, int anchor)	/* returns dfa for reg expr s */
81 {
82 	int i, use, nuse;
83 	fa *pfa;
84 	static int now = 1;
85 
86 	if (setvec == 0) {	/* first time through any RE */
87 		maxsetvec = MAXLIN;
88 		setvec = (int *) calloc(maxsetvec, sizeof(int));
89 		tmpset = (int *) calloc(maxsetvec, sizeof(int));
90 		if (setvec == 0 || tmpset == 0)
91 			overflo("out of space initializing makedfa");
92 	}
93 
94 	if (compile_time)	/* a constant for sure */
95 		return mkdfa(s, anchor);
96 	for (i = 0; i < nfatab; i++)	/* is it there already? */
97 		if (fatab[i]->anchor == anchor
98 		  && strcmp((const char *) fatab[i]->restr, s) == 0) {
99 			fatab[i]->use = now++;
100 			return fatab[i];
101 		}
102 	pfa = mkdfa(s, anchor);
103 	if (nfatab < NFA) {	/* room for another */
104 		fatab[nfatab] = pfa;
105 		fatab[nfatab]->use = now++;
106 		nfatab++;
107 		return pfa;
108 	}
109 	use = fatab[0]->use;	/* replace least-recently used */
110 	nuse = 0;
111 	for (i = 1; i < nfatab; i++)
112 		if (fatab[i]->use < use) {
113 			use = fatab[i]->use;
114 			nuse = i;
115 		}
116 	freefa(fatab[nuse]);
117 	fatab[nuse] = pfa;
118 	pfa->use = now++;
119 	return pfa;
120 }
121 
122 fa *mkdfa(const char *s, int anchor)	/* does the real work of making a dfa */
123 				/* anchor = 1 for anchored matches, else 0 */
124 {
125 	Node *p, *p1;
126 	fa *f;
127 
128 	p = reparse(s);
129 	p1 = op2(CAT, op2(STAR, op2(ALL, NIL, NIL), NIL), p);
130 		/* put ALL STAR in front of reg.  exp. */
131 	p1 = op2(CAT, p1, op2(FINAL, NIL, NIL));
132 		/* put FINAL after reg.  exp. */
133 
134 	poscnt = 0;
135 	penter(p1);	/* enter parent pointers and leaf indices */
136 	if ((f = (fa *) calloc(1, sizeof(fa) + poscnt*sizeof(rrow))) == NULL)
137 		overflo("out of space for fa");
138 	f->accept = poscnt-1;	/* penter has computed number of positions in re */
139 	cfoll(f, p1);	/* set up follow sets */
140 	freetr(p1);
141 	if ((f->posns[0] = (int *) calloc(*(f->re[0].lfollow), sizeof(int))) == NULL)
142 			overflo("out of space in makedfa");
143 	if ((f->posns[1] = (int *) calloc(1, sizeof(int))) == NULL)
144 		overflo("out of space in makedfa");
145 	*f->posns[1] = 0;
146 	f->initstat = makeinit(f, anchor);
147 	f->anchor = anchor;
148 	f->restr = (uschar *) tostring(s);
149 	return f;
150 }
151 
152 int makeinit(fa *f, int anchor)
153 {
154 	int i, k;
155 
156 	f->curstat = 2;
157 	f->out[2] = 0;
158 	f->reset = 0;
159 	k = *(f->re[0].lfollow);
160 	xfree(f->posns[2]);
161 	if ((f->posns[2] = (int *) calloc(k+1, sizeof(int))) == NULL)
162 		overflo("out of space in makeinit");
163 	for (i=0; i <= k; i++) {
164 		(f->posns[2])[i] = (f->re[0].lfollow)[i];
165 	}
166 	if ((f->posns[2])[1] == f->accept)
167 		f->out[2] = 1;
168 	for (i=0; i < NCHARS; i++)
169 		f->gototab[2][i] = 0;
170 	f->curstat = cgoto(f, 2, HAT);
171 	if (anchor) {
172 		*f->posns[2] = k-1;	/* leave out position 0 */
173 		for (i=0; i < k; i++) {
174 			(f->posns[0])[i] = (f->posns[2])[i];
175 		}
176 
177 		f->out[0] = f->out[2];
178 		if (f->curstat != 2)
179 			--(*f->posns[f->curstat]);
180 	}
181 	return f->curstat;
182 }
183 
184 void penter(Node *p)	/* set up parent pointers and leaf indices */
185 {
186 	switch (type(p)) {
187 	ELEAF
188 	LEAF
189 		info(p) = poscnt;
190 		poscnt++;
191 		break;
192 	UNARY
193 		penter(left(p));
194 		parent(left(p)) = p;
195 		break;
196 	case CAT:
197 	case OR:
198 		penter(left(p));
199 		penter(right(p));
200 		parent(left(p)) = p;
201 		parent(right(p)) = p;
202 		break;
203 	default:	/* can't happen */
204 		FATAL("can't happen: unknown type %d in penter", type(p));
205 		break;
206 	}
207 }
208 
209 void freetr(Node *p)	/* free parse tree */
210 {
211 	switch (type(p)) {
212 	ELEAF
213 	LEAF
214 		xfree(p);
215 		break;
216 	UNARY
217 		freetr(left(p));
218 		xfree(p);
219 		break;
220 	case CAT:
221 	case OR:
222 		freetr(left(p));
223 		freetr(right(p));
224 		xfree(p);
225 		break;
226 	default:	/* can't happen */
227 		FATAL("can't happen: unknown type %d in freetr", type(p));
228 		break;
229 	}
230 }
231 
232 /* in the parsing of regular expressions, metacharacters like . have */
233 /* to be seen literally;  \056 is not a metacharacter. */
234 
235 int hexstr(char **pp)	/* find and eval hex string at pp, return new p */
236 {			/* only pick up one 8-bit byte (2 chars) */
237 	uschar *p;
238 	int n = 0;
239 	int i;
240 
241 	for (i = 0, p = (uschar *) *pp; i < 2 && isxdigit(*p); i++, p++) {
242 		if (isdigit(*p))
243 			n = 16 * n + *p - '0';
244 		else if (*p >= 'a' && *p <= 'f')
245 			n = 16 * n + *p - 'a' + 10;
246 		else if (*p >= 'A' && *p <= 'F')
247 			n = 16 * n + *p - 'A' + 10;
248 	}
249 	*pp = (char *) p;
250 	return n;
251 }
252 
253 #define isoctdigit(c) ((c) >= '0' && (c) <= '7')	/* multiple use of arg */
254 
255 int quoted(char **pp)	/* pick up next thing after a \\ */
256 			/* and increment *pp */
257 {
258 	char *p = *pp;
259 	int c;
260 
261 	if ((c = *p++) == 't')
262 		c = '\t';
263 	else if (c == 'n')
264 		c = '\n';
265 	else if (c == 'f')
266 		c = '\f';
267 	else if (c == 'r')
268 		c = '\r';
269 	else if (c == 'b')
270 		c = '\b';
271 	else if (c == '\\')
272 		c = '\\';
273 	else if (c == 'x') {	/* hexadecimal goo follows */
274 		c = hexstr(&p);	/* this adds a null if number is invalid */
275 	} else if (isoctdigit(c)) {	/* \d \dd \ddd */
276 		int n = c - '0';
277 		if (isoctdigit(*p)) {
278 			n = 8 * n + *p++ - '0';
279 			if (isoctdigit(*p))
280 				n = 8 * n + *p++ - '0';
281 		}
282 		c = n;
283 	} /* else */
284 		/* c = c; */
285 	*pp = p;
286 	return c;
287 }
288 
289 char *cclenter(const char *argp)	/* add a character class */
290 {
291 	int i, c, c2;
292 	uschar *p = (uschar *) argp;
293 	uschar *op, *bp;
294 	static uschar *buf = 0;
295 	static int bufsz = 100;
296 
297 	op = p;
298 	if (buf == 0 && (buf = (uschar *) malloc(bufsz)) == NULL)
299 		FATAL("out of space for character class [%.10s...] 1", p);
300 	bp = buf;
301 	for (i = 0; (c = *p++) != 0; ) {
302 		if (c == '\\') {
303 			c = quoted((char **) &p);
304 		} else if (c == '-' && i > 0 && bp[-1] != 0) {
305 			if (*p != 0) {
306 				c = bp[-1];
307 				c2 = *p++;
308 				if (c2 == '\\')
309 					c2 = quoted((char **) &p);
310 				if (c > c2) {	/* empty; ignore */
311 					bp--;
312 					i--;
313 					continue;
314 				}
315 				while (c < c2) {
316 					if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, "cclenter1"))
317 						FATAL("out of space for character class [%.10s...] 2", p);
318 					*bp++ = ++c;
319 					i++;
320 				}
321 				continue;
322 			}
323 		}
324 		if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, "cclenter2"))
325 			FATAL("out of space for character class [%.10s...] 3", p);
326 		*bp++ = c;
327 		i++;
328 	}
329 	*bp = 0;
330 	dprintf( ("cclenter: in = |%s|, out = |%s|\n", op, buf) );
331 	xfree(op);
332 	return (char *) tostring((char *) buf);
333 }
334 
335 void overflo(const char *s)
336 {
337 	FATAL("regular expression too big: %.30s...", s);
338 }
339 
340 void cfoll(fa *f, Node *v)	/* enter follow set of each leaf of vertex v into lfollow[leaf] */
341 {
342 	int i;
343 	int *p;
344 
345 	switch (type(v)) {
346 	ELEAF
347 	LEAF
348 		f->re[info(v)].ltype = type(v);
349 		f->re[info(v)].lval.np = right(v);
350 		while (f->accept >= maxsetvec) {	/* guessing here! */
351 			maxsetvec *= 4;
352 			setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
353 			tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int));
354 			if (setvec == 0 || tmpset == 0)
355 				overflo("out of space in cfoll()");
356 		}
357 		for (i = 0; i <= f->accept; i++)
358 			setvec[i] = 0;
359 		setcnt = 0;
360 		follow(v);	/* computes setvec and setcnt */
361 		if ((p = (int *) calloc(setcnt+1, sizeof(int))) == NULL)
362 			overflo("out of space building follow set");
363 		f->re[info(v)].lfollow = p;
364 		*p = setcnt;
365 		for (i = f->accept; i >= 0; i--)
366 			if (setvec[i] == 1)
367 				*++p = i;
368 		break;
369 	UNARY
370 		cfoll(f,left(v));
371 		break;
372 	case CAT:
373 	case OR:
374 		cfoll(f,left(v));
375 		cfoll(f,right(v));
376 		break;
377 	default:	/* can't happen */
378 		FATAL("can't happen: unknown type %d in cfoll", type(v));
379 	}
380 }
381 
382 int first(Node *p)	/* collects initially active leaves of p into setvec */
383 			/* returns 0 if p matches empty string */
384 {
385 	int b, lp;
386 
387 	switch (type(p)) {
388 	ELEAF
389 	LEAF
390 		lp = info(p);	/* look for high-water mark of subscripts */
391 		while (setcnt >= maxsetvec || lp >= maxsetvec) {	/* guessing here! */
392 			maxsetvec *= 4;
393 			setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
394 			tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int));
395 			if (setvec == 0 || tmpset == 0)
396 				overflo("out of space in first()");
397 		}
398 		if (type(p) == EMPTYRE) {
399 			setvec[lp] = 0;
400 			return(0);
401 		}
402 		if (setvec[lp] != 1) {
403 			setvec[lp] = 1;
404 			setcnt++;
405 		}
406 		if (type(p) == CCL && (*(char *) right(p)) == '\0')
407 			return(0);		/* empty CCL */
408 		else return(1);
409 	case PLUS:
410 		if (first(left(p)) == 0) return(0);
411 		return(1);
412 	case STAR:
413 	case QUEST:
414 		first(left(p));
415 		return(0);
416 	case CAT:
417 		if (first(left(p)) == 0 && first(right(p)) == 0) return(0);
418 		return(1);
419 	case OR:
420 		b = first(right(p));
421 		if (first(left(p)) == 0 || b == 0) return(0);
422 		return(1);
423 	}
424 	FATAL("can't happen: unknown type %d in first", type(p));	/* can't happen */
425 	return(-1);
426 }
427 
428 void follow(Node *v)	/* collects leaves that can follow v into setvec */
429 {
430 	Node *p;
431 
432 	if (type(v) == FINAL)
433 		return;
434 	p = parent(v);
435 	switch (type(p)) {
436 	case STAR:
437 	case PLUS:
438 		first(v);
439 		follow(p);
440 		return;
441 
442 	case OR:
443 	case QUEST:
444 		follow(p);
445 		return;
446 
447 	case CAT:
448 		if (v == left(p)) {	/* v is left child of p */
449 			if (first(right(p)) == 0) {
450 				follow(p);
451 				return;
452 			}
453 		} else		/* v is right child */
454 			follow(p);
455 		return;
456 	}
457 }
458 
459 int member(int c, const char *sarg)	/* is c in s? */
460 {
461 	uschar *s = (uschar *) sarg;
462 
463 	while (*s)
464 		if (c == *s++)
465 			return(1);
466 	return(0);
467 }
468 
469 int match(fa *f, const char *p0)	/* shortest match ? */
470 {
471 	int s, ns;
472 	uschar *p = (uschar *) p0;
473 
474 	s = f->reset ? makeinit(f,0) : f->initstat;
475 	if (f->out[s])
476 		return(1);
477 	do {
478 		/* assert(*p < NCHARS); */
479 		if ((ns = f->gototab[s][*p]) != 0)
480 			s = ns;
481 		else
482 			s = cgoto(f, s, *p);
483 		if (f->out[s])
484 			return(1);
485 	} while (*p++ != 0);
486 	return(0);
487 }
488 
489 int pmatch(fa *f, const char *p0)	/* longest match, for sub */
490 {
491 	int s, ns;
492 	uschar *p = (uschar *) p0;
493 	uschar *q;
494 	int i, k;
495 
496 	/* s = f->reset ? makeinit(f,1) : f->initstat; */
497 	if (f->reset) {
498 		f->initstat = s = makeinit(f,1);
499 	} else {
500 		s = f->initstat;
501 	}
502 	patbeg = (char *) p;
503 	patlen = -1;
504 	do {
505 		q = p;
506 		do {
507 			if (f->out[s])		/* final state */
508 				patlen = q-p;
509 			/* assert(*q < NCHARS); */
510 			if ((ns = f->gototab[s][*q]) != 0)
511 				s = ns;
512 			else
513 				s = cgoto(f, s, *q);
514 			if (s == 1) {	/* no transition */
515 				if (patlen >= 0) {
516 					patbeg = (char *) p;
517 					return(1);
518 				}
519 				else
520 					goto nextin;	/* no match */
521 			}
522 		} while (*q++ != 0);
523 		if (f->out[s])
524 			patlen = q-p-1;	/* don't count $ */
525 		if (patlen >= 0) {
526 			patbeg = (char *) p;
527 			return(1);
528 		}
529 	nextin:
530 		s = 2;
531 		if (f->reset) {
532 			for (i = 2; i <= f->curstat; i++)
533 				xfree(f->posns[i]);
534 			k = *f->posns[0];
535 			if ((f->posns[2] = (int *) calloc(k+1, sizeof(int))) == NULL)
536 				overflo("out of space in pmatch");
537 			for (i = 0; i <= k; i++)
538 				(f->posns[2])[i] = (f->posns[0])[i];
539 			f->initstat = f->curstat = 2;
540 			f->out[2] = f->out[0];
541 			for (i = 0; i < NCHARS; i++)
542 				f->gototab[2][i] = 0;
543 		}
544 	} while (*p++ != 0);
545 	return (0);
546 }
547 
548 int nematch(fa *f, const char *p0)	/* non-empty match, for sub */
549 {
550 	int s, ns;
551 	uschar *p = (uschar *) p0;
552 	uschar *q;
553 	int i, k;
554 
555 	/* s = f->reset ? makeinit(f,1) : f->initstat; */
556 	if (f->reset) {
557 		f->initstat = s = makeinit(f,1);
558 	} else {
559 		s = f->initstat;
560 	}
561 	patlen = -1;
562 	while (*p) {
563 		q = p;
564 		do {
565 			if (f->out[s])		/* final state */
566 				patlen = q-p;
567 			/* assert(*q < NCHARS); */
568 			if ((ns = f->gototab[s][*q]) != 0)
569 				s = ns;
570 			else
571 				s = cgoto(f, s, *q);
572 			if (s == 1) {	/* no transition */
573 				if (patlen > 0) {
574 					patbeg = (char *) p;
575 					return(1);
576 				} else
577 					goto nnextin;	/* no nonempty match */
578 			}
579 		} while (*q++ != 0);
580 		if (f->out[s])
581 			patlen = q-p-1;	/* don't count $ */
582 		if (patlen > 0 ) {
583 			patbeg = (char *) p;
584 			return(1);
585 		}
586 	nnextin:
587 		s = 2;
588 		if (f->reset) {
589 			for (i = 2; i <= f->curstat; i++)
590 				xfree(f->posns[i]);
591 			k = *f->posns[0];
592 			if ((f->posns[2] = (int *) calloc(k+1, sizeof(int))) == NULL)
593 				overflo("out of state space");
594 			for (i = 0; i <= k; i++)
595 				(f->posns[2])[i] = (f->posns[0])[i];
596 			f->initstat = f->curstat = 2;
597 			f->out[2] = f->out[0];
598 			for (i = 0; i < NCHARS; i++)
599 				f->gototab[2][i] = 0;
600 		}
601 		p++;
602 	}
603 	return (0);
604 }
605 
606 Node *reparse(const char *p)	/* parses regular expression pointed to by p */
607 {			/* uses relex() to scan regular expression */
608 	Node *np;
609 
610 	dprintf( ("reparse <%s>\n", p) );
611 	lastre = prestr = (uschar *) p;	/* prestr points to string to be parsed */
612 	rtok = relex();
613 	/* GNU compatibility: an empty regexp matches anything */
614 	if (rtok == '\0') {
615 		/* FATAL("empty regular expression"); previous */
616 		return(op2(EMPTYRE, NIL, NIL));
617 	}
618 	np = regexp();
619 	if (rtok != '\0')
620 		FATAL("syntax error in regular expression %s at %s", lastre, prestr);
621 	return(np);
622 }
623 
624 Node *regexp(void)	/* top-level parse of reg expr */
625 {
626 	return (alt(concat(primary())));
627 }
628 
629 Node *primary(void)
630 {
631 	Node *np;
632 
633 	switch (rtok) {
634 	case CHAR:
635 		np = op2(CHAR, NIL, itonp(rlxval));
636 		rtok = relex();
637 		return (unary(np));
638 	case ALL:
639 		rtok = relex();
640 		return (unary(op2(ALL, NIL, NIL)));
641 	case EMPTYRE:
642 		rtok = relex();
643 		return (unary(op2(ALL, NIL, NIL)));
644 	case DOT:
645 		rtok = relex();
646 		return (unary(op2(DOT, NIL, NIL)));
647 	case CCL:
648 		np = op2(CCL, NIL, (Node*) cclenter((char *) rlxstr));
649 		rtok = relex();
650 		return (unary(np));
651 	case NCCL:
652 		np = op2(NCCL, NIL, (Node *) cclenter((char *) rlxstr));
653 		rtok = relex();
654 		return (unary(np));
655 	case '^':
656 		rtok = relex();
657 		return (unary(op2(CHAR, NIL, itonp(HAT))));
658 	case '$':
659 		rtok = relex();
660 		return (unary(op2(CHAR, NIL, NIL)));
661 	case '(':
662 		rtok = relex();
663 		if (rtok == ')') {	/* special pleading for () */
664 			rtok = relex();
665 			return unary(op2(CCL, NIL, (Node *) tostring("")));
666 		}
667 		np = regexp();
668 		if (rtok == ')') {
669 			rtok = relex();
670 			return (unary(np));
671 		}
672 		else
673 			FATAL("syntax error in regular expression %s at %s", lastre, prestr);
674 	default:
675 		FATAL("illegal primary in regular expression %s at %s", lastre, prestr);
676 	}
677 	return 0;	/*NOTREACHED*/
678 }
679 
680 Node *concat(Node *np)
681 {
682 	switch (rtok) {
683 	case CHAR: case DOT: case ALL: case EMPTYRE: case CCL: case NCCL: case '$': case '(':
684 		return (concat(op2(CAT, np, primary())));
685 	}
686 	return (np);
687 }
688 
689 Node *alt(Node *np)
690 {
691 	if (rtok == OR) {
692 		rtok = relex();
693 		return (alt(op2(OR, np, concat(primary()))));
694 	}
695 	return (np);
696 }
697 
698 Node *unary(Node *np)
699 {
700 	switch (rtok) {
701 	case STAR:
702 		rtok = relex();
703 		return (unary(op2(STAR, np, NIL)));
704 	case PLUS:
705 		rtok = relex();
706 		return (unary(op2(PLUS, np, NIL)));
707 	case QUEST:
708 		rtok = relex();
709 		return (unary(op2(QUEST, np, NIL)));
710 	default:
711 		return (np);
712 	}
713 }
714 
715 /*
716  * Character class definitions conformant to the POSIX locale as
717  * defined in IEEE P1003.1 draft 7 of June 2001, assuming the source
718  * and operating character sets are both ASCII (ISO646) or supersets
719  * thereof.
720  *
721  * Note that to avoid overflowing the temporary buffer used in
722  * relex(), the expanded character class (prior to range expansion)
723  * must be less than twice the size of their full name.
724  */
725 
726 /* Because isblank doesn't show up in any of the header files on any
727  * system i use, it's defined here.  if some other locale has a richer
728  * definition of "blank", define HAS_ISBLANK and provide your own
729  * version.
730  * the parentheses here are an attempt to find a path through the maze
731  * of macro definition and/or function and/or version provided.  thanks
732  * to nelson beebe for the suggestion; let's see if it works everywhere.
733  */
734 
735 #ifndef HAS_ISBLANK
736 
737 int (isblank)(int c)
738 {
739 	return c==' ' || c=='\t';
740 }
741 
742 #endif
743 
744 struct charclass {
745 	const char *cc_name;
746 	int cc_namelen;
747 	int (*cc_func)(int);
748 } charclasses[] = {
749 	{ "alnum",	5,	isalnum },
750 	{ "alpha",	5,	isalpha },
751 	{ "blank",	5,	isblank },
752 	{ "cntrl",	5,	iscntrl },
753 	{ "digit",	5,	isdigit },
754 	{ "graph",	5,	isgraph },
755 	{ "lower",	5,	islower },
756 	{ "print",	5,	isprint },
757 	{ "punct",	5,	ispunct },
758 	{ "space",	5,	isspace },
759 	{ "upper",	5,	isupper },
760 	{ "xdigit",	6,	isxdigit },
761 	{ NULL,		0,	NULL },
762 };
763 
764 
765 int relex(void)		/* lexical analyzer for reparse */
766 {
767 	int c, n;
768 	int cflag;
769 	static uschar *buf = 0;
770 	static int bufsz = 100;
771 	uschar *bp;
772 	struct charclass *cc;
773 	int i;
774 
775 	switch (c = *prestr++) {
776 	case '|': return OR;
777 	case '*': return STAR;
778 	case '+': return PLUS;
779 	case '?': return QUEST;
780 	case '.': return DOT;
781 	case '\0': prestr--; return '\0';
782 	case '^':
783 	case '$':
784 	case '(':
785 	case ')':
786 		return c;
787 	case '\\':
788 		rlxval = quoted((char **) &prestr);
789 		return CHAR;
790 	default:
791 		rlxval = c;
792 		return CHAR;
793 	case '[':
794 		if (buf == 0 && (buf = (uschar *) malloc(bufsz)) == NULL)
795 			FATAL("out of space in reg expr %.10s..", lastre);
796 		bp = buf;
797 		if (*prestr == '^') {
798 			cflag = 1;
799 			prestr++;
800 		}
801 		else
802 			cflag = 0;
803 		n = 2 * strlen((const char *) prestr)+1;
804 		if (!adjbuf((char **) &buf, &bufsz, n, n, (char **) &bp, "relex1"))
805 			FATAL("out of space for reg expr %.10s...", lastre);
806 		for (; ; ) {
807 			if ((c = *prestr++) == '\\') {
808 				*bp++ = '\\';
809 				if ((c = *prestr++) == '\0')
810 					FATAL("nonterminated character class %.20s...", lastre);
811 				*bp++ = c;
812 			/* } else if (c == '\n') { */
813 			/* 	FATAL("newline in character class %.20s...", lastre); */
814 			} else if (c == '[' && *prestr == ':') {
815 				/* POSIX char class names, Dag-Erling Smorgrav, des@ofug.org */
816 				for (cc = charclasses; cc->cc_name; cc++)
817 					if (strncmp((const char *) prestr + 1, (const char *) cc->cc_name, cc->cc_namelen) == 0)
818 						break;
819 				if (cc->cc_name != NULL && prestr[1 + cc->cc_namelen] == ':' &&
820 				    prestr[2 + cc->cc_namelen] == ']') {
821 					prestr += cc->cc_namelen + 3;
822 					for (i = 0; i < NCHARS; i++) {
823 						if (!adjbuf((char **) &buf, &bufsz, bp-buf+1, 100, (char **) &bp, "relex2"))
824 						    FATAL("out of space for reg expr %.10s...", lastre);
825 						if (cc->cc_func(i)) {
826 							*bp++ = i;
827 							n++;
828 						}
829 					}
830 				} else
831 					*bp++ = c;
832 			} else if (c == '\0') {
833 				FATAL("nonterminated character class %.20s", lastre);
834 			} else if (bp == buf) {	/* 1st char is special */
835 				*bp++ = c;
836 			} else if (c == ']') {
837 				*bp++ = 0;
838 				rlxstr = (uschar *) tostring((char *) buf);
839 				if (cflag == 0)
840 					return CCL;
841 				else
842 					return NCCL;
843 			} else
844 				*bp++ = c;
845 		}
846 	}
847 }
848 
849 int cgoto(fa *f, int s, int c)
850 {
851 	int i, j, k;
852 	int *p, *q;
853 
854 	assert(c == HAT || c < NCHARS);
855 	while (f->accept >= maxsetvec) {	/* guessing here! */
856 		maxsetvec *= 4;
857 		setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
858 		tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int));
859 		if (setvec == 0 || tmpset == 0)
860 			overflo("out of space in cgoto()");
861 	}
862 	for (i = 0; i <= f->accept; i++)
863 		setvec[i] = 0;
864 	setcnt = 0;
865 	/* compute positions of gototab[s,c] into setvec */
866 	p = f->posns[s];
867 	for (i = 1; i <= *p; i++) {
868 		if ((k = f->re[p[i]].ltype) != FINAL) {
869 			if ((k == CHAR && c == ptoi(f->re[p[i]].lval.np))
870 			 || (k == DOT && c != 0 && c != HAT)
871 			 || (k == ALL && c != 0)
872 			 || (k == EMPTYRE && c != 0)
873 			 || (k == CCL && member(c, (char *) f->re[p[i]].lval.up))
874 			 || (k == NCCL && !member(c, (char *) f->re[p[i]].lval.up) && c != 0 && c != HAT)) {
875 				q = f->re[p[i]].lfollow;
876 				for (j = 1; j <= *q; j++) {
877 					if (q[j] >= maxsetvec) {
878 						maxsetvec *= 4;
879 						setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
880 						tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int));
881 						if (setvec == 0 || tmpset == 0)
882 							overflo("cgoto overflow");
883 					}
884 					if (setvec[q[j]] == 0) {
885 						setcnt++;
886 						setvec[q[j]] = 1;
887 					}
888 				}
889 			}
890 		}
891 	}
892 	/* determine if setvec is a previous state */
893 	tmpset[0] = setcnt;
894 	j = 1;
895 	for (i = f->accept; i >= 0; i--)
896 		if (setvec[i]) {
897 			tmpset[j++] = i;
898 		}
899 	/* tmpset == previous state? */
900 	for (i = 1; i <= f->curstat; i++) {
901 		p = f->posns[i];
902 		if ((k = tmpset[0]) != p[0])
903 			goto different;
904 		for (j = 1; j <= k; j++)
905 			if (tmpset[j] != p[j])
906 				goto different;
907 		/* setvec is state i */
908 		f->gototab[s][c] = i;
909 		return i;
910 	  different:;
911 	}
912 
913 	/* add tmpset to current set of states */
914 	if (f->curstat >= NSTATES-1) {
915 		f->curstat = 2;
916 		f->reset = 1;
917 		for (i = 2; i < NSTATES; i++)
918 			xfree(f->posns[i]);
919 	} else
920 		++(f->curstat);
921 	for (i = 0; i < NCHARS; i++)
922 		f->gototab[f->curstat][i] = 0;
923 	xfree(f->posns[f->curstat]);
924 	if ((p = (int *) calloc(setcnt+1, sizeof(int))) == NULL)
925 		overflo("out of space in cgoto");
926 
927 	f->posns[f->curstat] = p;
928 	f->gototab[s][c] = f->curstat;
929 	for (i = 0; i <= setcnt; i++)
930 		p[i] = tmpset[i];
931 	if (setvec[f->accept])
932 		f->out[f->curstat] = 1;
933 	else
934 		f->out[f->curstat] = 0;
935 	return f->curstat;
936 }
937 
938 
939 void freefa(fa *f)	/* free a finite automaton */
940 {
941 	int i;
942 
943 	if (f == NULL)
944 		return;
945 	for (i = 0; i <= f->curstat; i++)
946 		xfree(f->posns[i]);
947 	for (i = 0; i <= f->accept; i++) {
948 		xfree(f->re[i].lfollow);
949 		if (f->re[i].ltype == CCL || f->re[i].ltype == NCCL)
950 			xfree((f->re[i].lval.np));
951 	}
952 	xfree(f->restr);
953 	xfree(f);
954 }
955