b.c revision 90902
185587Sobrien/****************************************************************
285587SobrienCopyright (C) Lucent Technologies 1997
385587SobrienAll Rights Reserved
485587Sobrien
585587SobrienPermission to use, copy, modify, and distribute this software and
685587Sobrienits documentation for any purpose and without fee is hereby
785587Sobriengranted, provided that the above copyright notice appear in all
885587Sobriencopies and that both that the copyright notice and this
985587Sobrienpermission notice and warranty disclaimer appear in supporting
1085587Sobriendocumentation, and that the name Lucent Technologies or any of
1185587Sobrienits entities not be used in advertising or publicity pertaining
1285587Sobriento distribution of the software without specific, written prior
1385587Sobrienpermission.
1485587Sobrien
1585587SobrienLUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
1685587SobrienINCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
1785587SobrienIN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
1885587SobrienSPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
1985587SobrienWHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
2085587SobrienIN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
2185587SobrienARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
2285587SobrienTHIS SOFTWARE.
2385587Sobrien****************************************************************/
2485587Sobrien
2585587Sobrien/* lasciate ogne speranza, voi ch'entrate. */
2685587Sobrien
2785587Sobrien#define	DEBUG
2885587Sobrien
2985587Sobrien#include <ctype.h>
3085587Sobrien#include <stdio.h>
3185587Sobrien#include <string.h>
3285587Sobrien#include <stdlib.h>
3385587Sobrien#include "awk.h"
3485587Sobrien#include "ytab.h"
3585587Sobrien
3685587Sobrien#define	HAT	(NCHARS-2)	/* matches ^ in regular expr */
3785587Sobrien				/* NCHARS is 2**n */
3885587Sobrien#define MAXLIN 22
3985587Sobrien
4085587Sobrien#define type(v)		(v)->nobj	/* badly overloaded here */
4185587Sobrien#define info(v)		(v)->ntype	/* badly overloaded here */
4285587Sobrien#define left(v)		(v)->narg[0]
4385587Sobrien#define right(v)	(v)->narg[1]
4485587Sobrien#define parent(v)	(v)->nnext
4585587Sobrien
4685587Sobrien#define LEAF	case CCL: case NCCL: case CHAR: case DOT: case FINAL: case ALL:
4785587Sobrien#define UNARY	case STAR: case PLUS: case QUEST:
4885587Sobrien
4985587Sobrien/* encoding in tree Nodes:
5085587Sobrien	leaf (CCL, NCCL, CHAR, DOT, FINAL, ALL):
5185587Sobrien		left is index, right contains value or pointer to value
5285587Sobrien	unary (STAR, PLUS, QUEST): left is child, right is null
5385587Sobrien	binary (CAT, OR): left and right are children
5485587Sobrien	parent contains pointer to parent
5585587Sobrien*/
5685587Sobrien
5785587Sobrien
5885587Sobrienint	*setvec;
5985587Sobrienint	*tmpset;
6085587Sobrienint	maxsetvec = 0;
6185587Sobrien
6285587Sobrienint	rtok;		/* next token in current re */
6385587Sobrienint	rlxval;
6485587Sobrienstatic uschar	*rlxstr;
6585587Sobrienstatic uschar	*prestr;	/* current position in current re */
6685587Sobrienstatic uschar	*lastre;	/* origin of last re */
6785587Sobrien
6885587Sobrienstatic	int setcnt;
6985587Sobrienstatic	int poscnt;
7085587Sobrien
7185587Sobrienchar	*patbeg;
7285587Sobrienint	patlen;
7385587Sobrien
7485587Sobrien#define	NFA	20	/* cache this many dynamic fa's */
7585587Sobrienfa	*fatab[NFA];
7685587Sobrienint	nfatab	= 0;	/* entries in fatab */
7785587Sobrien
7885587Sobrienfa *makedfa(char *s, int anchor)	/* returns dfa for reg expr s */
7985587Sobrien{
8085587Sobrien	int i, use, nuse;
8185587Sobrien	fa *pfa;
8285587Sobrien	static int now = 1;
8385587Sobrien
8485587Sobrien	if (setvec == 0) {	/* first time through any RE */
8585587Sobrien		maxsetvec = MAXLIN;
8685587Sobrien		setvec = (int *) malloc(maxsetvec * sizeof(int));
8785587Sobrien		tmpset = (int *) malloc(maxsetvec * sizeof(int));
8885587Sobrien		if (setvec == 0 || tmpset == 0)
8985587Sobrien			overflo("out of space initializing makedfa");
9085587Sobrien	}
9185587Sobrien
9285587Sobrien	if (compile_time)	/* a constant for sure */
9385587Sobrien		return mkdfa(s, anchor);
9485587Sobrien	for (i = 0; i < nfatab; i++)	/* is it there already? */
9585587Sobrien		if (fatab[i]->anchor == anchor
9690902Sdes		  && strcmp((const char *) fatab[i]->restr, s) == 0) {
9785587Sobrien			fatab[i]->use = now++;
9885587Sobrien			return fatab[i];
9985587Sobrien		}
10085587Sobrien	pfa = mkdfa(s, anchor);
10185587Sobrien	if (nfatab < NFA) {	/* room for another */
10285587Sobrien		fatab[nfatab] = pfa;
10385587Sobrien		fatab[nfatab]->use = now++;
10485587Sobrien		nfatab++;
10585587Sobrien		return pfa;
10685587Sobrien	}
10785587Sobrien	use = fatab[0]->use;	/* replace least-recently used */
10885587Sobrien	nuse = 0;
10985587Sobrien	for (i = 1; i < nfatab; i++)
11085587Sobrien		if (fatab[i]->use < use) {
11185587Sobrien			use = fatab[i]->use;
11285587Sobrien			nuse = i;
11385587Sobrien		}
11485587Sobrien	freefa(fatab[nuse]);
11585587Sobrien	fatab[nuse] = pfa;
11685587Sobrien	pfa->use = now++;
11785587Sobrien	return pfa;
11885587Sobrien}
11985587Sobrien
12085587Sobrienfa *mkdfa(char *s, int anchor)	/* does the real work of making a dfa */
12185587Sobrien				/* anchor = 1 for anchored matches, else 0 */
12285587Sobrien{
12385587Sobrien	Node *p, *p1;
12485587Sobrien	fa *f;
12585587Sobrien
12685587Sobrien	p = reparse(s);
12785587Sobrien	p1 = op2(CAT, op2(STAR, op2(ALL, NIL, NIL), NIL), p);
12885587Sobrien		/* put ALL STAR in front of reg.  exp. */
12985587Sobrien	p1 = op2(CAT, p1, op2(FINAL, NIL, NIL));
13085587Sobrien		/* put FINAL after reg.  exp. */
13185587Sobrien
13285587Sobrien	poscnt = 0;
13385587Sobrien	penter(p1);	/* enter parent pointers and leaf indices */
13485587Sobrien	if ((f = (fa *) calloc(1, sizeof(fa) + poscnt*sizeof(rrow))) == NULL)
13585587Sobrien		overflo("out of space for fa");
13685587Sobrien	f->accept = poscnt-1;	/* penter has computed number of positions in re */
13785587Sobrien	cfoll(f, p1);	/* set up follow sets */
13885587Sobrien	freetr(p1);
13985587Sobrien	if ((f->posns[0] = (int *) calloc(1, *(f->re[0].lfollow)*sizeof(int))) == NULL)
14085587Sobrien			overflo("out of space in makedfa");
14185587Sobrien	if ((f->posns[1] = (int *) calloc(1, sizeof(int))) == NULL)
14285587Sobrien		overflo("out of space in makedfa");
14385587Sobrien	*f->posns[1] = 0;
14485587Sobrien	f->initstat = makeinit(f, anchor);
14585587Sobrien	f->anchor = anchor;
14685587Sobrien	f->restr = (uschar *) tostring(s);
14785587Sobrien	return f;
14885587Sobrien}
14985587Sobrien
15085587Sobrienint makeinit(fa *f, int anchor)
15185587Sobrien{
15285587Sobrien	int i, k;
15385587Sobrien
15485587Sobrien	f->curstat = 2;
15585587Sobrien	f->out[2] = 0;
15685587Sobrien	f->reset = 0;
15785587Sobrien	k = *(f->re[0].lfollow);
15885587Sobrien	xfree(f->posns[2]);
15985587Sobrien	if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL)
16085587Sobrien		overflo("out of space in makeinit");
16185587Sobrien	for (i=0; i <= k; i++) {
16285587Sobrien		(f->posns[2])[i] = (f->re[0].lfollow)[i];
16385587Sobrien	}
16485587Sobrien	if ((f->posns[2])[1] == f->accept)
16585587Sobrien		f->out[2] = 1;
16685587Sobrien	for (i=0; i < NCHARS; i++)
16785587Sobrien		f->gototab[2][i] = 0;
16885587Sobrien	f->curstat = cgoto(f, 2, HAT);
16985587Sobrien	if (anchor) {
17085587Sobrien		*f->posns[2] = k-1;	/* leave out position 0 */
17185587Sobrien		for (i=0; i < k; i++) {
17285587Sobrien			(f->posns[0])[i] = (f->posns[2])[i];
17385587Sobrien		}
17485587Sobrien
17585587Sobrien		f->out[0] = f->out[2];
17685587Sobrien		if (f->curstat != 2)
17785587Sobrien			--(*f->posns[f->curstat]);
17885587Sobrien	}
17985587Sobrien	return f->curstat;
18085587Sobrien}
18185587Sobrien
18285587Sobrienvoid penter(Node *p)	/* set up parent pointers and leaf indices */
18385587Sobrien{
18485587Sobrien	switch (type(p)) {
18585587Sobrien	LEAF
18685587Sobrien		info(p) = poscnt;
18785587Sobrien		poscnt++;
18885587Sobrien		break;
18985587Sobrien	UNARY
19085587Sobrien		penter(left(p));
19185587Sobrien		parent(left(p)) = p;
19285587Sobrien		break;
19385587Sobrien	case CAT:
19485587Sobrien	case OR:
19585587Sobrien		penter(left(p));
19685587Sobrien		penter(right(p));
19785587Sobrien		parent(left(p)) = p;
19885587Sobrien		parent(right(p)) = p;
19985587Sobrien		break;
20085587Sobrien	default:	/* can't happen */
20185587Sobrien		FATAL("can't happen: unknown type %d in penter", type(p));
20285587Sobrien		break;
20385587Sobrien	}
20485587Sobrien}
20585587Sobrien
20685587Sobrienvoid freetr(Node *p)	/* free parse tree */
20785587Sobrien{
20885587Sobrien	switch (type(p)) {
20985587Sobrien	LEAF
21085587Sobrien		xfree(p);
21185587Sobrien		break;
21285587Sobrien	UNARY
21385587Sobrien		freetr(left(p));
21485587Sobrien		xfree(p);
21585587Sobrien		break;
21685587Sobrien	case CAT:
21785587Sobrien	case OR:
21885587Sobrien		freetr(left(p));
21985587Sobrien		freetr(right(p));
22085587Sobrien		xfree(p);
22185587Sobrien		break;
22285587Sobrien	default:	/* can't happen */
22385587Sobrien		FATAL("can't happen: unknown type %d in freetr", type(p));
22485587Sobrien		break;
22585587Sobrien	}
22685587Sobrien}
22785587Sobrien
22885587Sobrien/* in the parsing of regular expressions, metacharacters like . have */
22985587Sobrien/* to be seen literally;  \056 is not a metacharacter. */
23085587Sobrien
23185587Sobrienint hexstr(char **pp)	/* find and eval hex string at pp, return new p */
23285587Sobrien{			/* only pick up one 8-bit byte (2 chars) */
23385587Sobrien	uschar *p;
23485587Sobrien	int n = 0;
23585587Sobrien	int i;
23685587Sobrien
23785587Sobrien	for (i = 0, p = (uschar *) *pp; i < 2 && isxdigit(*p); i++, p++) {
23885587Sobrien		if (isdigit(*p))
23985587Sobrien			n = 16 * n + *p - '0';
24085587Sobrien		else if (*p >= 'a' && *p <= 'f')
24185587Sobrien			n = 16 * n + *p - 'a' + 10;
24285587Sobrien		else if (*p >= 'A' && *p <= 'F')
24385587Sobrien			n = 16 * n + *p - 'A' + 10;
24485587Sobrien	}
24585587Sobrien	*pp = (char *) p;
24685587Sobrien	return n;
24785587Sobrien}
24885587Sobrien
24985587Sobrien#define isoctdigit(c) ((c) >= '0' && (c) <= '7')	/* multiple use of arg */
25085587Sobrien
25185587Sobrienint quoted(char **pp)	/* pick up next thing after a \\ */
25285587Sobrien			/* and increment *pp */
25385587Sobrien{
25485587Sobrien	char *p = *pp;
25585587Sobrien	int c;
25685587Sobrien
25785587Sobrien	if ((c = *p++) == 't')
25885587Sobrien		c = '\t';
25985587Sobrien	else if (c == 'n')
26085587Sobrien		c = '\n';
26185587Sobrien	else if (c == 'f')
26285587Sobrien		c = '\f';
26385587Sobrien	else if (c == 'r')
26485587Sobrien		c = '\r';
26585587Sobrien	else if (c == 'b')
26685587Sobrien		c = '\b';
26785587Sobrien	else if (c == '\\')
26885587Sobrien		c = '\\';
26985587Sobrien	else if (c == 'x') {	/* hexadecimal goo follows */
27085587Sobrien		c = hexstr(&p);	/* this adds a null if number is invalid */
27185587Sobrien	} else if (isoctdigit(c)) {	/* \d \dd \ddd */
27285587Sobrien		int n = c - '0';
27385587Sobrien		if (isoctdigit(*p)) {
27485587Sobrien			n = 8 * n + *p++ - '0';
27585587Sobrien			if (isoctdigit(*p))
27685587Sobrien				n = 8 * n + *p++ - '0';
27785587Sobrien		}
27885587Sobrien		c = n;
27985587Sobrien	} /* else */
28085587Sobrien		/* c = c; */
28185587Sobrien	*pp = p;
28285587Sobrien	return c;
28385587Sobrien}
28485587Sobrien
28585587Sobrienchar *cclenter(char *argp)	/* add a character class */
28685587Sobrien{
28785587Sobrien	int i, c, c2;
28885587Sobrien	uschar *p = (uschar *) argp;
28985587Sobrien	uschar *op, *bp;
29085587Sobrien	static uschar *buf = 0;
29185587Sobrien	static int bufsz = 100;
29285587Sobrien
29385587Sobrien	op = p;
29485587Sobrien	if (buf == 0 && (buf = (uschar *) malloc(bufsz)) == NULL)
29585587Sobrien		FATAL("out of space for character class [%.10s...] 1", p);
29685587Sobrien	bp = buf;
29785587Sobrien	for (i = 0; (c = *p++) != 0; ) {
29885587Sobrien		if (c == '\\') {
29985587Sobrien			c = quoted((char **) &p);
30085587Sobrien		} else if (c == '-' && i > 0 && bp[-1] != 0) {
30185587Sobrien			if (*p != 0) {
30285587Sobrien				c = bp[-1];
30385587Sobrien				c2 = *p++;
30485587Sobrien				if (c2 == '\\')
30585587Sobrien					c2 = quoted((char **) &p);
30685587Sobrien				if (c > c2) {	/* empty; ignore */
30785587Sobrien					bp--;
30885587Sobrien					i--;
30985587Sobrien					continue;
31085587Sobrien				}
31185587Sobrien				while (c < c2) {
31285587Sobrien					if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, 0))
31385587Sobrien						FATAL("out of space for character class [%.10s...] 2", p);
31485587Sobrien					*bp++ = ++c;
31585587Sobrien					i++;
31685587Sobrien				}
31785587Sobrien				continue;
31885587Sobrien			}
31985587Sobrien		}
32085587Sobrien		if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, 0))
32185587Sobrien			FATAL("out of space for character class [%.10s...] 3", p);
32285587Sobrien		*bp++ = c;
32385587Sobrien		i++;
32485587Sobrien	}
32585587Sobrien	*bp = 0;
32685587Sobrien	dprintf( ("cclenter: in = |%s|, out = |%s|\n", op, buf) );
32785587Sobrien	xfree(op);
32885587Sobrien	return (char *) tostring((char *) buf);
32985587Sobrien}
33085587Sobrien
33185587Sobrienvoid overflo(char *s)
33285587Sobrien{
33385587Sobrien	FATAL("regular expression too big: %.30s...", s);
33485587Sobrien}
33585587Sobrien
33685587Sobrienvoid cfoll(fa *f, Node *v)	/* enter follow set of each leaf of vertex v into lfollow[leaf] */
33785587Sobrien{
33885587Sobrien	int i;
33985587Sobrien	int *p;
34085587Sobrien
34185587Sobrien	switch (type(v)) {
34285587Sobrien	LEAF
34385587Sobrien		f->re[info(v)].ltype = type(v);
34485587Sobrien		f->re[info(v)].lval.np = right(v);
34585587Sobrien		while (f->accept >= maxsetvec) {	/* guessing here! */
34685587Sobrien			maxsetvec *= 4;
34785587Sobrien			setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
34885587Sobrien			tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int));
34985587Sobrien			if (setvec == 0 || tmpset == 0)
35085587Sobrien				overflo("out of space in cfoll()");
35185587Sobrien		}
35285587Sobrien		for (i = 0; i <= f->accept; i++)
35385587Sobrien			setvec[i] = 0;
35485587Sobrien		setcnt = 0;
35585587Sobrien		follow(v);	/* computes setvec and setcnt */
35685587Sobrien		if ((p = (int *) calloc(1, (setcnt+1)*sizeof(int))) == NULL)
35785587Sobrien			overflo("out of space building follow set");
35885587Sobrien		f->re[info(v)].lfollow = p;
35985587Sobrien		*p = setcnt;
36085587Sobrien		for (i = f->accept; i >= 0; i--)
36185587Sobrien			if (setvec[i] == 1)
36285587Sobrien				*++p = i;
36385587Sobrien		break;
36485587Sobrien	UNARY
36585587Sobrien		cfoll(f,left(v));
36685587Sobrien		break;
36785587Sobrien	case CAT:
36885587Sobrien	case OR:
36985587Sobrien		cfoll(f,left(v));
37085587Sobrien		cfoll(f,right(v));
37185587Sobrien		break;
37285587Sobrien	default:	/* can't happen */
37385587Sobrien		FATAL("can't happen: unknown type %d in cfoll", type(v));
37485587Sobrien	}
37585587Sobrien}
37685587Sobrien
37785587Sobrienint first(Node *p)	/* collects initially active leaves of p into setvec */
37885587Sobrien			/* returns 1 if p matches empty string */
37985587Sobrien{
38085587Sobrien	int b, lp;
38185587Sobrien
38285587Sobrien	switch (type(p)) {
38385587Sobrien	LEAF
38485587Sobrien		lp = info(p);	/* look for high-water mark of subscripts */
38585587Sobrien		while (setcnt >= maxsetvec || lp >= maxsetvec) {	/* guessing here! */
38685587Sobrien			maxsetvec *= 4;
38785587Sobrien			setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
38885587Sobrien			tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int));
38985587Sobrien			if (setvec == 0 || tmpset == 0)
39085587Sobrien				overflo("out of space in first()");
39185587Sobrien		}
39285587Sobrien		if (setvec[lp] != 1) {
39385587Sobrien			setvec[lp] = 1;
39485587Sobrien			setcnt++;
39585587Sobrien		}
39685587Sobrien		if (type(p) == CCL && (*(char *) right(p)) == '\0')
39785587Sobrien			return(0);		/* empty CCL */
39885587Sobrien		else return(1);
39985587Sobrien	case PLUS:
40085587Sobrien		if (first(left(p)) == 0) return(0);
40185587Sobrien		return(1);
40285587Sobrien	case STAR:
40385587Sobrien	case QUEST:
40485587Sobrien		first(left(p));
40585587Sobrien		return(0);
40685587Sobrien	case CAT:
40785587Sobrien		if (first(left(p)) == 0 && first(right(p)) == 0) return(0);
40885587Sobrien		return(1);
40985587Sobrien	case OR:
41085587Sobrien		b = first(right(p));
41185587Sobrien		if (first(left(p)) == 0 || b == 0) return(0);
41285587Sobrien		return(1);
41385587Sobrien	}
41485587Sobrien	FATAL("can't happen: unknown type %d in first", type(p));	/* can't happen */
41585587Sobrien	return(-1);
41685587Sobrien}
41785587Sobrien
41885587Sobrienvoid follow(Node *v)	/* collects leaves that can follow v into setvec */
41985587Sobrien{
42085587Sobrien	Node *p;
42185587Sobrien
42285587Sobrien	if (type(v) == FINAL)
42385587Sobrien		return;
42485587Sobrien	p = parent(v);
42585587Sobrien	switch (type(p)) {
42685587Sobrien	case STAR:
42785587Sobrien	case PLUS:
42885587Sobrien		first(v);
42985587Sobrien		follow(p);
43085587Sobrien		return;
43185587Sobrien
43285587Sobrien	case OR:
43385587Sobrien	case QUEST:
43485587Sobrien		follow(p);
43585587Sobrien		return;
43685587Sobrien
43785587Sobrien	case CAT:
43885587Sobrien		if (v == left(p)) {	/* v is left child of p */
43985587Sobrien			if (first(right(p)) == 0) {
44085587Sobrien				follow(p);
44185587Sobrien				return;
44285587Sobrien			}
44385587Sobrien		} else		/* v is right child */
44485587Sobrien			follow(p);
44585587Sobrien		return;
44685587Sobrien	}
44785587Sobrien}
44885587Sobrien
44985587Sobrienint member(int c, char *sarg)	/* is c in s? */
45085587Sobrien{
45185587Sobrien	uschar *s = (uschar *) sarg;
45285587Sobrien
45385587Sobrien	while (*s)
45485587Sobrien		if (c == *s++)
45585587Sobrien			return(1);
45685587Sobrien	return(0);
45785587Sobrien}
45885587Sobrien
45985587Sobrienint match(fa *f, char *p0)	/* shortest match ? */
46085587Sobrien{
46185587Sobrien	int s, ns;
46285587Sobrien	uschar *p = (uschar *) p0;
46385587Sobrien
46485587Sobrien	s = f->reset ? makeinit(f,0) : f->initstat;
46585587Sobrien	if (f->out[s])
46685587Sobrien		return(1);
46785587Sobrien	do {
46885587Sobrien		if ((ns = f->gototab[s][*p]) != 0)
46985587Sobrien			s = ns;
47085587Sobrien		else
47185587Sobrien			s = cgoto(f, s, *p);
47285587Sobrien		if (f->out[s])
47385587Sobrien			return(1);
47485587Sobrien	} while (*p++ != 0);
47585587Sobrien	return(0);
47685587Sobrien}
47785587Sobrien
47885587Sobrienint pmatch(fa *f, char *p0)	/* longest match, for sub */
47985587Sobrien{
48085587Sobrien	int s, ns;
48185587Sobrien	uschar *p = (uschar *) p0;
48285587Sobrien	uschar *q;
48385587Sobrien	int i, k;
48485587Sobrien
48585587Sobrien	s = f->reset ? makeinit(f,1) : f->initstat;
48685587Sobrien	patbeg = (char *) p;
48785587Sobrien	patlen = -1;
48885587Sobrien	do {
48985587Sobrien		q = p;
49085587Sobrien		do {
49185587Sobrien			if (f->out[s])		/* final state */
49285587Sobrien				patlen = q-p;
49385587Sobrien			if ((ns = f->gototab[s][*q]) != 0)
49485587Sobrien				s = ns;
49585587Sobrien			else
49685587Sobrien				s = cgoto(f, s, *q);
49785587Sobrien			if (s == 1) {	/* no transition */
49885587Sobrien				if (patlen >= 0) {
49985587Sobrien					patbeg = (char *) p;
50085587Sobrien					return(1);
50185587Sobrien				}
50285587Sobrien				else
50385587Sobrien					goto nextin;	/* no match */
50485587Sobrien			}
50585587Sobrien		} while (*q++ != 0);
50685587Sobrien		if (f->out[s])
50785587Sobrien			patlen = q-p-1;	/* don't count $ */
50885587Sobrien		if (patlen >= 0) {
50985587Sobrien			patbeg = (char *) p;
51085587Sobrien			return(1);
51185587Sobrien		}
51285587Sobrien	nextin:
51385587Sobrien		s = 2;
51485587Sobrien		if (f->reset) {
51585587Sobrien			for (i = 2; i <= f->curstat; i++)
51685587Sobrien				xfree(f->posns[i]);
51785587Sobrien			k = *f->posns[0];
51885587Sobrien			if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL)
51985587Sobrien				overflo("out of space in pmatch");
52085587Sobrien			for (i = 0; i <= k; i++)
52185587Sobrien				(f->posns[2])[i] = (f->posns[0])[i];
52285587Sobrien			f->initstat = f->curstat = 2;
52385587Sobrien			f->out[2] = f->out[0];
52485587Sobrien			for (i = 0; i < NCHARS; i++)
52585587Sobrien				f->gototab[2][i] = 0;
52685587Sobrien		}
52785587Sobrien	} while (*p++ != 0);
52885587Sobrien	return (0);
52985587Sobrien}
53085587Sobrien
53185587Sobrienint nematch(fa *f, char *p0)	/* non-empty match, for sub */
53285587Sobrien{
53385587Sobrien	int s, ns;
53485587Sobrien	uschar *p = (uschar *) p0;
53585587Sobrien	uschar *q;
53685587Sobrien	int i, k;
53785587Sobrien
53885587Sobrien	s = f->reset ? makeinit(f,1) : f->initstat;
53985587Sobrien	patlen = -1;
54085587Sobrien	while (*p) {
54185587Sobrien		q = p;
54285587Sobrien		do {
54385587Sobrien			if (f->out[s])		/* final state */
54485587Sobrien				patlen = q-p;
54585587Sobrien			if ((ns = f->gototab[s][*q]) != 0)
54685587Sobrien				s = ns;
54785587Sobrien			else
54885587Sobrien				s = cgoto(f, s, *q);
54985587Sobrien			if (s == 1) {	/* no transition */
55085587Sobrien				if (patlen > 0) {
55185587Sobrien					patbeg = (char *) p;
55285587Sobrien					return(1);
55385587Sobrien				} else
55485587Sobrien					goto nnextin;	/* no nonempty match */
55585587Sobrien			}
55685587Sobrien		} while (*q++ != 0);
55785587Sobrien		if (f->out[s])
55885587Sobrien			patlen = q-p-1;	/* don't count $ */
55985587Sobrien		if (patlen > 0 ) {
56085587Sobrien			patbeg = (char *) p;
56185587Sobrien			return(1);
56285587Sobrien		}
56385587Sobrien	nnextin:
56485587Sobrien		s = 2;
56585587Sobrien		if (f->reset) {
56685587Sobrien			for (i = 2; i <= f->curstat; i++)
56785587Sobrien				xfree(f->posns[i]);
56885587Sobrien			k = *f->posns[0];
56985587Sobrien			if ((f->posns[2] = (int *) calloc(1, (k+1)*sizeof(int))) == NULL)
57085587Sobrien				overflo("out of state space");
57185587Sobrien			for (i = 0; i <= k; i++)
57285587Sobrien				(f->posns[2])[i] = (f->posns[0])[i];
57385587Sobrien			f->initstat = f->curstat = 2;
57485587Sobrien			f->out[2] = f->out[0];
57585587Sobrien			for (i = 0; i < NCHARS; i++)
57685587Sobrien				f->gototab[2][i] = 0;
57785587Sobrien		}
57885587Sobrien		p++;
57985587Sobrien	}
58085587Sobrien	return (0);
58185587Sobrien}
58285587Sobrien
58385587SobrienNode *reparse(char *p)	/* parses regular expression pointed to by p */
58485587Sobrien{			/* uses relex() to scan regular expression */
58585587Sobrien	Node *np;
58685587Sobrien
58785587Sobrien	dprintf( ("reparse <%s>\n", p) );
58885587Sobrien	lastre = prestr = (uschar *) p;	/* prestr points to string to be parsed */
58985587Sobrien	rtok = relex();
59085587Sobrien	if (rtok == '\0')
59185587Sobrien		FATAL("empty regular expression");
59285587Sobrien	np = regexp();
59385587Sobrien	if (rtok != '\0')
59485587Sobrien		FATAL("syntax error in regular expression %s at %s", lastre, prestr);
59585587Sobrien	return(np);
59685587Sobrien}
59785587Sobrien
59885587SobrienNode *regexp(void)	/* top-level parse of reg expr */
59985587Sobrien{
60085587Sobrien	return (alt(concat(primary())));
60185587Sobrien}
60285587Sobrien
60385587SobrienNode *primary(void)
60485587Sobrien{
60585587Sobrien	Node *np;
60685587Sobrien
60785587Sobrien	switch (rtok) {
60885587Sobrien	case CHAR:
60985587Sobrien		np = op2(CHAR, NIL, itonp(rlxval));
61085587Sobrien		rtok = relex();
61185587Sobrien		return (unary(np));
61285587Sobrien	case ALL:
61385587Sobrien		rtok = relex();
61485587Sobrien		return (unary(op2(ALL, NIL, NIL)));
61585587Sobrien	case DOT:
61685587Sobrien		rtok = relex();
61785587Sobrien		return (unary(op2(DOT, NIL, NIL)));
61885587Sobrien	case CCL:
61985587Sobrien		np = op2(CCL, NIL, (Node*) cclenter((char *) rlxstr));
62085587Sobrien		rtok = relex();
62185587Sobrien		return (unary(np));
62285587Sobrien	case NCCL:
62385587Sobrien		np = op2(NCCL, NIL, (Node *) cclenter((char *) rlxstr));
62485587Sobrien		rtok = relex();
62585587Sobrien		return (unary(np));
62685587Sobrien	case '^':
62785587Sobrien		rtok = relex();
62885587Sobrien		return (unary(op2(CHAR, NIL, itonp(HAT))));
62985587Sobrien	case '$':
63085587Sobrien		rtok = relex();
63185587Sobrien		return (unary(op2(CHAR, NIL, NIL)));
63285587Sobrien	case '(':
63385587Sobrien		rtok = relex();
63485587Sobrien		if (rtok == ')') {	/* special pleading for () */
63585587Sobrien			rtok = relex();
63685587Sobrien			return unary(op2(CCL, NIL, (Node *) tostring("")));
63785587Sobrien		}
63885587Sobrien		np = regexp();
63985587Sobrien		if (rtok == ')') {
64085587Sobrien			rtok = relex();
64185587Sobrien			return (unary(np));
64285587Sobrien		}
64385587Sobrien		else
64485587Sobrien			FATAL("syntax error in regular expression %s at %s", lastre, prestr);
64585587Sobrien	default:
64685587Sobrien		FATAL("illegal primary in regular expression %s at %s", lastre, prestr);
64785587Sobrien	}
64885587Sobrien	return 0;	/*NOTREACHED*/
64985587Sobrien}
65085587Sobrien
65185587SobrienNode *concat(Node *np)
65285587Sobrien{
65385587Sobrien	switch (rtok) {
65485587Sobrien	case CHAR: case DOT: case ALL: case CCL: case NCCL: case '$': case '(':
65585587Sobrien		return (concat(op2(CAT, np, primary())));
65685587Sobrien	}
65785587Sobrien	return (np);
65885587Sobrien}
65985587Sobrien
66085587SobrienNode *alt(Node *np)
66185587Sobrien{
66285587Sobrien	if (rtok == OR) {
66385587Sobrien		rtok = relex();
66485587Sobrien		return (alt(op2(OR, np, concat(primary()))));
66585587Sobrien	}
66685587Sobrien	return (np);
66785587Sobrien}
66885587Sobrien
66985587SobrienNode *unary(Node *np)
67085587Sobrien{
67185587Sobrien	switch (rtok) {
67285587Sobrien	case STAR:
67385587Sobrien		rtok = relex();
67485587Sobrien		return (unary(op2(STAR, np, NIL)));
67585587Sobrien	case PLUS:
67685587Sobrien		rtok = relex();
67785587Sobrien		return (unary(op2(PLUS, np, NIL)));
67885587Sobrien	case QUEST:
67985587Sobrien		rtok = relex();
68085587Sobrien		return (unary(op2(QUEST, np, NIL)));
68185587Sobrien	default:
68285587Sobrien		return (np);
68385587Sobrien	}
68485587Sobrien}
68585587Sobrien
68690902Sdes/*
68790902Sdes * Character class definitions conformant to the POSIX locale as
68890902Sdes * defined in IEEE P1003.1 draft 7 of June 2001, assuming the source
68990902Sdes * and operating character sets are both ASCII (ISO646) or supersets
69090902Sdes * thereof.
69190902Sdes *
69290902Sdes * Note that to avoid overflowing the temporary buffer used in
69390902Sdes * relex(), the expanded character class (prior to range expansion)
69490902Sdes * must be less than twice the size of their full name.
69590902Sdes */
69690902Sdesstruct charclass {
69790902Sdes	const char *cc_name;
69890902Sdes	int cc_namelen;
69990902Sdes	const char *cc_expand;
70090902Sdes} charclasses[] = {
70190902Sdes	{ "alnum",	5,	"0-9A-Za-z" },
70290902Sdes	{ "alpha",	5,	"A-Za-z" },
70390902Sdes	{ "blank",	5,	" \t" },
70490902Sdes	{ "cntrl",	5,	"\000-\037\177" },
70590902Sdes	{ "digit",	5,	"0-9" },
70690902Sdes	{ "graph",	5,	"\041-\176" },
70790902Sdes	{ "lower",	5,	"a-z" },
70890902Sdes	{ "print",	5,	" \041-\176" },
70990902Sdes	{ "punct",	5,	"\041-\057\072-\100\133-\140\173-\176" },
71090902Sdes	{ "space",	5,	" \f\n\r\t\v" },
71190902Sdes	{ "upper",	5,	"A-Z" },
71290902Sdes	{ "xdigit",	6,	"0-9A-Fa-f" },
71390902Sdes	{ NULL,		0,	NULL },
71490902Sdes};
71590902Sdes
71690902Sdes
71785587Sobrienint relex(void)		/* lexical analyzer for reparse */
71885587Sobrien{
71985587Sobrien	int c, n;
72085587Sobrien	int cflag;
72185587Sobrien	static uschar *buf = 0;
72285587Sobrien	static int bufsz = 100;
72385587Sobrien	uschar *bp;
72490902Sdes	struct charclass *cc;
72590902Sdes	const uschar *p;
72685587Sobrien
72785587Sobrien	switch (c = *prestr++) {
72885587Sobrien	case '|': return OR;
72985587Sobrien	case '*': return STAR;
73085587Sobrien	case '+': return PLUS;
73185587Sobrien	case '?': return QUEST;
73285587Sobrien	case '.': return DOT;
73385587Sobrien	case '\0': prestr--; return '\0';
73485587Sobrien	case '^':
73585587Sobrien	case '$':
73685587Sobrien	case '(':
73785587Sobrien	case ')':
73885587Sobrien		return c;
73985587Sobrien	case '\\':
74085587Sobrien		rlxval = quoted((char **) &prestr);
74185587Sobrien		return CHAR;
74285587Sobrien	default:
74385587Sobrien		rlxval = c;
74485587Sobrien		return CHAR;
74585587Sobrien	case '[':
74685587Sobrien		if (buf == 0 && (buf = (uschar *) malloc(bufsz)) == NULL)
74785587Sobrien			FATAL("out of space in reg expr %.10s..", lastre);
74885587Sobrien		bp = buf;
74985587Sobrien		if (*prestr == '^') {
75085587Sobrien			cflag = 1;
75185587Sobrien			prestr++;
75285587Sobrien		}
75385587Sobrien		else
75485587Sobrien			cflag = 0;
75590902Sdes		n = 2 * strlen((const char *) prestr)+1;
75685587Sobrien		if (!adjbuf((char **) &buf, &bufsz, n, n, (char **) &bp, 0))
75785587Sobrien			FATAL("out of space for reg expr %.10s...", lastre);
75885587Sobrien		for (; ; ) {
75985587Sobrien			if ((c = *prestr++) == '\\') {
76085587Sobrien				*bp++ = '\\';
76185587Sobrien				if ((c = *prestr++) == '\0')
76285587Sobrien					FATAL("nonterminated character class %.20s...", lastre);
76385587Sobrien				*bp++ = c;
76485587Sobrien			/* } else if (c == '\n') { */
76585587Sobrien			/* 	FATAL("newline in character class %.20s...", lastre); */
76690902Sdes			} else if (c == '[' && *prestr == ':') {
76790902Sdes				/* POSIX char class names, Dag-Erling Smorgrav, des@ofug.org */
76890902Sdes				for (cc = charclasses; cc->cc_name; cc++)
76990902Sdes					if (strncmp((const char *) prestr + 1, (const char *) cc->cc_name, cc->cc_namelen) == 0)
77090902Sdes						break;
77190902Sdes				if (cc->cc_name != NULL && prestr[1 + cc->cc_namelen] == ':' &&
77290902Sdes				    prestr[2 + cc->cc_namelen] == ']') {
77390902Sdes					prestr += cc->cc_namelen + 3;
77490902Sdes					for (p = (const uschar *) cc->cc_expand; *p; p++)
77590902Sdes						*bp++ = *p;
77690902Sdes				} else
77790902Sdes					*bp++ = c;
77885587Sobrien			} else if (c == '\0') {
77985587Sobrien				FATAL("nonterminated character class %.20s", lastre);
78085587Sobrien			} else if (bp == buf) {	/* 1st char is special */
78185587Sobrien				*bp++ = c;
78285587Sobrien			} else if (c == ']') {
78385587Sobrien				*bp++ = 0;
78485587Sobrien				rlxstr = (uschar *) tostring((char *) buf);
78585587Sobrien				if (cflag == 0)
78685587Sobrien					return CCL;
78785587Sobrien				else
78885587Sobrien					return NCCL;
78985587Sobrien			} else
79085587Sobrien				*bp++ = c;
79185587Sobrien		}
79285587Sobrien	}
79385587Sobrien}
79485587Sobrien
79585587Sobrienint cgoto(fa *f, int s, int c)
79685587Sobrien{
79785587Sobrien	int i, j, k;
79885587Sobrien	int *p, *q;
79985587Sobrien
80085587Sobrien	if (c < 0 || c > 255)
80185587Sobrien		FATAL("can't happen: neg char %d in cgoto", c);
80285587Sobrien	while (f->accept >= maxsetvec) {	/* guessing here! */
80385587Sobrien		maxsetvec *= 4;
80485587Sobrien		setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
80585587Sobrien		tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(int));
80685587Sobrien		if (setvec == 0 || tmpset == 0)
80785587Sobrien			overflo("out of space in cgoto()");
80885587Sobrien	}
80985587Sobrien	for (i = 0; i <= f->accept; i++)
81085587Sobrien		setvec[i] = 0;
81185587Sobrien	setcnt = 0;
81285587Sobrien	/* compute positions of gototab[s,c] into setvec */
81385587Sobrien	p = f->posns[s];
81485587Sobrien	for (i = 1; i <= *p; i++) {
81585587Sobrien		if ((k = f->re[p[i]].ltype) != FINAL) {
81685587Sobrien			if ((k == CHAR && c == ptoi(f->re[p[i]].lval.np))
81785587Sobrien			 || (k == DOT && c != 0 && c != HAT)
81885587Sobrien			 || (k == ALL && c != 0)
81985587Sobrien			 || (k == CCL && member(c, (char *) f->re[p[i]].lval.up))
82085587Sobrien			 || (k == NCCL && !member(c, (char *) f->re[p[i]].lval.up) && c != 0 && c != HAT)) {
82185587Sobrien				q = f->re[p[i]].lfollow;
82285587Sobrien				for (j = 1; j <= *q; j++) {
82385587Sobrien					if (q[j] >= maxsetvec) {
82485587Sobrien						maxsetvec *= 4;
82585587Sobrien						setvec = (int *) realloc(setvec, maxsetvec * sizeof(int));
82685587Sobrien						tmpset = (int *) realloc(setvec, maxsetvec * sizeof(int));
82785587Sobrien						if (setvec == 0 || tmpset == 0)
82885587Sobrien							overflo("cgoto overflow");
82985587Sobrien					}
83085587Sobrien					if (setvec[q[j]] == 0) {
83185587Sobrien						setcnt++;
83285587Sobrien						setvec[q[j]] = 1;
83385587Sobrien					}
83485587Sobrien				}
83585587Sobrien			}
83685587Sobrien		}
83785587Sobrien	}
83885587Sobrien	/* determine if setvec is a previous state */
83985587Sobrien	tmpset[0] = setcnt;
84085587Sobrien	j = 1;
84185587Sobrien	for (i = f->accept; i >= 0; i--)
84285587Sobrien		if (setvec[i]) {
84385587Sobrien			tmpset[j++] = i;
84485587Sobrien		}
84585587Sobrien	/* tmpset == previous state? */
84685587Sobrien	for (i = 1; i <= f->curstat; i++) {
84785587Sobrien		p = f->posns[i];
84885587Sobrien		if ((k = tmpset[0]) != p[0])
84985587Sobrien			goto different;
85085587Sobrien		for (j = 1; j <= k; j++)
85185587Sobrien			if (tmpset[j] != p[j])
85285587Sobrien				goto different;
85385587Sobrien		/* setvec is state i */
85485587Sobrien		f->gototab[s][c] = i;
85585587Sobrien		return i;
85685587Sobrien	  different:;
85785587Sobrien	}
85885587Sobrien
85985587Sobrien	/* add tmpset to current set of states */
86085587Sobrien	if (f->curstat >= NSTATES-1) {
86185587Sobrien		f->curstat = 2;
86285587Sobrien		f->reset = 1;
86385587Sobrien		for (i = 2; i < NSTATES; i++)
86485587Sobrien			xfree(f->posns[i]);
86585587Sobrien	} else
86685587Sobrien		++(f->curstat);
86785587Sobrien	for (i = 0; i < NCHARS; i++)
86885587Sobrien		f->gototab[f->curstat][i] = 0;
86985587Sobrien	xfree(f->posns[f->curstat]);
87085587Sobrien	if ((p = (int *) calloc(1, (setcnt+1)*sizeof(int))) == NULL)
87185587Sobrien		overflo("out of space in cgoto");
87285587Sobrien
87385587Sobrien	f->posns[f->curstat] = p;
87485587Sobrien	f->gototab[s][c] = f->curstat;
87585587Sobrien	for (i = 0; i <= setcnt; i++)
87685587Sobrien		p[i] = tmpset[i];
87785587Sobrien	if (setvec[f->accept])
87885587Sobrien		f->out[f->curstat] = 1;
87985587Sobrien	else
88085587Sobrien		f->out[f->curstat] = 0;
88185587Sobrien	return f->curstat;
88285587Sobrien}
88385587Sobrien
88485587Sobrien
88585587Sobrienvoid freefa(fa *f)	/* free a finite automaton */
88685587Sobrien{
88785587Sobrien	int i;
88885587Sobrien
88985587Sobrien	if (f == NULL)
89085587Sobrien		return;
89185587Sobrien	for (i = 0; i <= f->curstat; i++)
89285587Sobrien		xfree(f->posns[i]);
89385587Sobrien	for (i = 0; i <= f->accept; i++) {
89485587Sobrien		xfree(f->re[i].lfollow);
89585587Sobrien		if (f->re[i].ltype == CCL || f->re[i].ltype == NCCL)
89685587Sobrien			xfree((f->re[i].lval.np));
89785587Sobrien	}
89885587Sobrien	xfree(f->restr);
89985587Sobrien	xfree(f);
90085587Sobrien}
901