8354 sync regcomp(3C) with upstream

Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>

1 files changed, 1784 insertions, 0 deletions

diff --git a/usr/src/lib/libc/port/regex/regcomp.c b/usr/src/lib/libc/port/regex/regcomp.c
new file mode 100644
index 0000000000..c1c1ce90a3
--- /dev/null
+++ b/usr/src/lib/libc/port/regex/regcomp.c
@@ -0,0 +1,1784 @@
+/*
+ * Copyright 2013 Garrett D'Amore <garrett@damore.org>
+ * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright 2012 Milan Jurik. All rights reserved.
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "lint.h"
+#include "file64.h"
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <regex.h>
+#include <wchar.h>
+#include <wctype.h>
+
+#include "../locale/runetype.h"
+#include "../locale/collate.h"
+
+#include "utils.h"
+#include "regex2.h"
+
+#include "cname.h"
+#include "../locale/mblocal.h"
+
+/*
+ * parse structure, passed up and down to avoid global variables and
+ * other clumsinesses
+ */
+struct parse {
+	const char *next;	/* next character in RE */
+	const char *end;	/* end of string (-> NUL normally) */
+	int error;		/* has an error been seen? */
+	sop *strip;		/* malloced strip */
+	sopno ssize;		/* malloced strip size (allocated) */
+	sopno slen;		/* malloced strip length (used) */
+	int ncsalloc;		/* number of csets allocated */
+	struct re_guts *g;
+#define	NPAREN	10		/* we need to remember () 1-9 for back refs */
+	sopno pbegin[NPAREN];	/* -> ( ([0] unused) */
+	sopno pend[NPAREN];	/* -> ) ([0] unused) */
+};
+
+/* ========= begin header generated by ./mkh ========= */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* === regcomp.c === */
+static void p_ere(struct parse *p, int stop);
+static void p_ere_exp(struct parse *p);
+static void p_str(struct parse *p);
+static void p_bre(struct parse *p, int end1, int end2);
+static int p_simp_re(struct parse *p, int starordinary);
+static int p_count(struct parse *p);
+static void p_bracket(struct parse *p);
+static void p_b_term(struct parse *p, cset *cs);
+static void p_b_cclass(struct parse *p, cset *cs);
+static void p_b_eclass(struct parse *p, cset *cs);
+static wint_t p_b_symbol(struct parse *p);
+static wint_t p_b_coll_elem(struct parse *p, wint_t endc);
+static wint_t othercase(wint_t ch);
+static void bothcases(struct parse *p, wint_t ch);
+static void ordinary(struct parse *p, wint_t ch);
+static void nonnewline(struct parse *p);
+static void repeat(struct parse *p, sopno start, int from, int to);
+static int seterr(struct parse *p, int e);
+static cset *allocset(struct parse *p);
+static void freeset(struct parse *p, cset *cs);
+static void CHadd(struct parse *p, cset *cs, wint_t ch);
+static void CHaddrange(struct parse *p, cset *cs, wint_t min, wint_t max);
+static void CHaddtype(struct parse *p, cset *cs, wctype_t wct);
+static wint_t singleton(cset *cs);
+static sopno dupl(struct parse *p, sopno start, sopno finish);
+static void doemit(struct parse *p, sop op, size_t opnd);
+static void doinsert(struct parse *p, sop op, size_t opnd, sopno pos);
+static void dofwd(struct parse *p, sopno pos, sop value);
+static int enlarge(struct parse *p, sopno size);
+static void stripsnug(struct parse *p, struct re_guts *g);
+static void findmust(struct parse *p, struct re_guts *g);
+static int altoffset(sop *scan, int offset);
+static void computejumps(struct parse *p, struct re_guts *g);
+static void computematchjumps(struct parse *p, struct re_guts *g);
+static sopno pluscount(struct parse *p, struct re_guts *g);
+static wint_t wgetnext(struct parse *p);
+
+#ifdef __cplusplus
+}
+#endif
+/* ========= end header generated by ./mkh ========= */
+
+static char nuls[10];		/* place to point scanner in event of error */
+
+/*
+ * macros for use with parse structure
+ * BEWARE:  these know that the parse structure is named `p' !!!
+ */
+#define	PEEK()	(*p->next)
+#define	PEEK2()	(*(p->next+1))
+#define	MORE()	(p->next < p->end)
+#define	MORE2()	(p->next+1 < p->end)
+#define	SEE(c)	(MORE() && PEEK() == (c))
+#define	SEETWO(a, b)	(MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
+#define	EAT(c)	((SEE(c)) ? (NEXT(), 1) : 0)
+#define	EATTWO(a, b)	((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
+#define	NEXT()	(p->next++)
+#define	NEXT2()	(p->next += 2)
+#define	NEXTn(n)	(p->next += (n))
+#define	GETNEXT()	(*p->next++)
+#define	WGETNEXT()	wgetnext(p)
+#define	SETERROR(e)	((void)seterr(p, (e)))
+#define	REQUIRE(co, e)	((co) || seterr(p, e))
+#define	MUSTSEE(c, e)	(REQUIRE(MORE() && PEEK() == (c), e))
+#define	MUSTEAT(c, e)	(REQUIRE(MORE() && GETNEXT() == (c), e))
+#define	MUSTNOTSEE(c, e)	(REQUIRE(!MORE() || PEEK() != (c), e))
+#define	EMIT(op, sopnd)	doemit(p, (sop)(op), (size_t)(sopnd))
+#define	INSERT(op, pos)	doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
+#define	AHEAD(pos)		dofwd(p, pos, HERE()-(pos))
+#define	ASTERN(sop, pos)	EMIT(sop, HERE()-pos)
+#define	HERE()		(p->slen)
+#define	THERE()		(p->slen - 1)
+#define	THERETHERE()	(p->slen - 2)
+#define	DROP(n)	(p->slen -= (n))
+
+#ifndef NDEBUG
+static int never = 0;		/* for use in asserts; shuts lint up */
+#else
+#define	never	0		/* some <assert.h>s have bugs too */
+#endif
+
+/*
+ * regcomp - interface for parser and compilation
+ */
+int				/* 0 success, otherwise REG_something */
+regcomp(regex_t *_RESTRICT_KYWD preg, const char *_RESTRICT_KYWD pattern,
+    int cflags)
+{
+	struct parse pa;
+	struct re_guts *g;
+	struct parse *p = &pa;
+	int i;
+	size_t len;
+	size_t maxlen;
+#ifdef REDEBUG
+#define	GOODFLAGS(f)	(f)
+#else
+#define	GOODFLAGS(f)	((f)&~REG_DUMP)
+#endif
+
+	/* We had REG_INVARG, but we don't have that on Solaris. */
+	cflags = GOODFLAGS(cflags);
+	if ((cflags&REG_EXTENDED) && (cflags&REG_NOSPEC))
+		return (REG_EFATAL);
+
+	if (cflags&REG_PEND) {
+		if (preg->re_endp < pattern)
+			return (REG_EFATAL);
+		len = preg->re_endp - pattern;
+	} else
+		len = strlen(pattern);
+
+	/* do the mallocs early so failure handling is easy */
+	g = (struct re_guts *)malloc(sizeof (struct re_guts));
+	if (g == NULL)
+		return (REG_ESPACE);
+	/*
+	 * Limit the pattern space to avoid a 32-bit overflow on buffer
+	 * extension.  Also avoid any signed overflow in case of conversion
+	 * so make the real limit based on a 31-bit overflow.
+	 *
+	 * Likely not applicable on 64-bit systems but handle the case
+	 * generically (who are we to stop people from using ~715MB+
+	 * patterns?).
+	 */
+	maxlen = ((size_t)-1 >> 1) / sizeof (sop) * 2 / 3;
+	if (len >= maxlen) {
+		free((char *)g);
+		return (REG_ESPACE);
+	}
+	p->ssize = len/(size_t)2*(size_t)3 + (size_t)1;	/* ugh */
+	assert(p->ssize >= len);
+
+	p->strip = (sop *)malloc(p->ssize * sizeof (sop));
+	p->slen = 0;
+	if (p->strip == NULL) {
+		free((char *)g);
+		return (REG_ESPACE);
+	}
+
+	/* set things up */
+	p->g = g;
+	p->next = pattern;	/* convenience; we do not modify it */
+	p->end = p->next + len;
+	p->error = 0;
+	p->ncsalloc = 0;
+	for (i = 0; i < NPAREN; i++) {
+		p->pbegin[i] = 0;
+		p->pend[i] = 0;
+	}
+	g->sets = NULL;
+	g->ncsets = 0;
+	g->cflags = cflags;
+	g->iflags = 0;
+	g->nbol = 0;
+	g->neol = 0;
+	g->must = NULL;
+	g->moffset = -1;
+	g->charjump = NULL;
+	g->matchjump = NULL;
+	g->mlen = 0;
+	g->nsub = 0;
+	g->backrefs = 0;
+
+	/* do it */
+	EMIT(OEND, 0);
+	g->firststate = THERE();
+	if (cflags&REG_EXTENDED)
+		p_ere(p, OUT);
+	else if (cflags&REG_NOSPEC)
+		p_str(p);
+	else
+		p_bre(p, OUT, OUT);
+	EMIT(OEND, 0);
+	g->laststate = THERE();
+
+	/* tidy up loose ends and fill things in */
+	stripsnug(p, g);
+	findmust(p, g);
+	/*
+	 * only use Boyer-Moore algorithm if the pattern is bigger
+	 * than three characters
+	 */
+	if (g->mlen > 3) {
+		computejumps(p, g);
+		computematchjumps(p, g);
+		if (g->matchjump == NULL && g->charjump != NULL) {
+			free(g->charjump);
+			g->charjump = NULL;
+		}
+	}
+	g->nplus = pluscount(p, g);
+	g->magic = MAGIC2;
+	preg->re_nsub = g->nsub;
+	preg->re_g = g;
+	preg->re_magic = MAGIC1;
+#ifndef REDEBUG
+	/* not debugging, so can't rely on the assert() in regexec() */
+	if (g->iflags&BAD)
+		SETERROR(REG_EFATAL);
+#endif
+
+	/* win or lose, we're done */
+	if (p->error != 0)	/* lose */
+		regfree(preg);
+	return (p->error);
+}
+
+/*
+ * p_ere - ERE parser top level, concatenation and alternation
+ */
+static void
+p_ere(struct parse *p,
+    int stop)		/* character this ERE should end at */
+{
+	char c;
+	sopno prevback;
+	sopno prevfwd;
+	sopno conc;
+	int first = 1;		/* is this the first alternative? */
+
+	for (;;) {
+		/* do a bunch of concatenated expressions */
+		conc = HERE();
+		while (MORE() && (c = PEEK()) != '|' && c != stop)
+			p_ere_exp(p);
+		/* require nonempty */
+		(void) REQUIRE(HERE() != conc, REG_BADPAT);
+
+		if (!EAT('|'))
+			break;		/* NOTE BREAK OUT */
+
+		if (first) {
+			INSERT(OCH_, conc);	/* offset is wrong */
+			prevfwd = conc;
+			prevback = conc;
+			first = 0;
+		}
+		ASTERN(OOR1, prevback);
+		prevback = THERE();
+		AHEAD(prevfwd);			/* fix previous offset */
+		prevfwd = HERE();
+		EMIT(OOR2, 0);			/* offset is very wrong */
+	}
+
+	if (!first) {		/* tail-end fixups */
+		AHEAD(prevfwd);
+		ASTERN(O_CH, prevback);
+	}
+
+	assert(!MORE() || SEE(stop));
+}
+
+/*
+ * p_ere_exp - parse one subERE, an atom possibly followed by a repetition op
+ */
+static void
+p_ere_exp(struct parse *p)
+{
+	char c;
+	wint_t wc;
+	sopno pos;
+	int count;
+	int count2;
+	sopno subno;
+	int wascaret = 0;
+
+	assert(MORE());		/* caller should have ensured this */
+	c = GETNEXT();
+
+	pos = HERE();
+	switch (c) {
+	case '(':
+		(void) REQUIRE(MORE(), REG_EPAREN);
+		p->g->nsub++;
+		subno = p->g->nsub;
+		if (subno < NPAREN)
+			p->pbegin[subno] = HERE();
+		EMIT(OLPAREN, subno);
+		if (!SEE(')'))
+			p_ere(p, ')');
+		if (subno < NPAREN) {
+			p->pend[subno] = HERE();
+			assert(p->pend[subno] != 0);
+		}
+		EMIT(ORPAREN, subno);
+		(void) MUSTEAT(')', REG_EPAREN);
+		break;
+#ifndef POSIX_MISTAKE
+	case ')':		/* happens only if no current unmatched ( */
+		/*
+		 * You may ask, why the ifndef?  Because I didn't notice
+		 * this until slightly too late for 1003.2, and none of the
+		 * other 1003.2 regular-expression reviewers noticed it at
+		 * all.  So an unmatched ) is legal POSIX, at least until
+		 * we can get it fixed.
+		 */
+		SETERROR(REG_EPAREN);
+		break;
+#endif
+	case '^':
+		EMIT(OBOL, 0);
+		p->g->iflags |= USEBOL;
+		p->g->nbol++;
+		wascaret = 1;
+		break;
+	case '$':
+		EMIT(OEOL, 0);
+		p->g->iflags |= USEEOL;
+		p->g->neol++;
+		break;
+	case '|':
+		SETERROR(REG_BADPAT);
+		break;
+	case '*':
+	case '+':
+	case '?':
+		SETERROR(REG_BADRPT);
+		break;
+	case '.':
+		if (p->g->cflags&REG_NEWLINE)
+			nonnewline(p);
+		else
+			EMIT(OANY, 0);
+		break;
+	case '[':
+		p_bracket(p);
+		break;
+	case '\\':
+		(void) REQUIRE(MORE(), REG_EESCAPE);
+		wc = WGETNEXT();
+		switch (wc) {
+		case '<':
+			EMIT(OBOW, 0);
+			break;
+		case '>':
+			EMIT(OEOW, 0);
+			break;
+		default:
+			ordinary(p, wc);
+			break;
+		}
+		break;
+	case '{':		/* okay as ordinary except if digit follows */
+		(void) REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT);
+		/* FALLTHROUGH */
+	default:
+		if (p->error != 0)
+			return;
+		p->next--;
+		wc = WGETNEXT();
+		ordinary(p, wc);
+		break;
+	}
+
+	if (!MORE())
+		return;
+	c = PEEK();
+	/* we call { a repetition if followed by a digit */
+	if (!(c == '*' || c == '+' || c == '?' ||
+	    (c == '{' && MORE2() && isdigit((uch)PEEK2()))))
+		return;		/* no repetition, we're done */
+	NEXT();
+
+	(void) REQUIRE(!wascaret, REG_BADRPT);
+	switch (c) {
+	case '*':	/* implemented as +? */
+		/* this case does not require the (y|) trick, noKLUDGE */
+		INSERT(OPLUS_, pos);
+		ASTERN(O_PLUS, pos);
+		INSERT(OQUEST_, pos);
+		ASTERN(O_QUEST, pos);
+		break;
+	case '+':
+		INSERT(OPLUS_, pos);
+		ASTERN(O_PLUS, pos);
+		break;
+	case '?':
+		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
+		INSERT(OCH_, pos);		/* offset slightly wrong */
+		ASTERN(OOR1, pos);		/* this one's right */
+		AHEAD(pos);			/* fix the OCH_ */
+		EMIT(OOR2, 0);			/* offset very wrong... */
+		AHEAD(THERE());			/* ...so fix it */
+		ASTERN(O_CH, THERETHERE());
+		break;
+	case '{':
+		count = p_count(p);
+		if (EAT(',')) {
+			if (isdigit((uch)PEEK())) {
+				count2 = p_count(p);
+				(void) REQUIRE(count <= count2, REG_BADBR);
+			} else		/* single number with comma */
+				count2 = INFINITY;
+		} else		/* just a single number */
+			count2 = count;
+		repeat(p, pos, count, count2);
+		if (!EAT('}')) {	/* error heuristics */
+			while (MORE() && PEEK() != '}')
+				NEXT();
+			(void) REQUIRE(MORE(), REG_EBRACE);
+			SETERROR(REG_BADBR);
+		}
+		break;
+	}
+
+	if (!MORE())
+		return;
+	c = PEEK();
+	if (!(c == '*' || c == '+' || c == '?' ||
+	    (c == '{' && MORE2() && isdigit((uch)PEEK2()))))
+		return;
+	SETERROR(REG_BADRPT);
+}
+
+/*
+ * p_str - string (no metacharacters) "parser"
+ */
+static void
+p_str(struct parse *p)
+{
+	(void) REQUIRE(MORE(), REG_BADPAT);
+	while (MORE())
+		ordinary(p, WGETNEXT());
+}
+
+/*
+ * p_bre - BRE parser top level, anchoring and concatenation
+ * Giving end1 as OUT essentially eliminates the end1/end2 check.
+ *
+ * This implementation is a bit of a kludge, in that a trailing $ is first
+ * taken as an ordinary character and then revised to be an anchor.
+ * The amount of lookahead needed to avoid this kludge is excessive.
+ */
+static void
+p_bre(struct parse *p,
+    int end1,		/* first terminating character */
+    int end2)		/* second terminating character */
+{
+	sopno start = HERE();
+	int first = 1;			/* first subexpression? */
+	int wasdollar = 0;
+
+	if (EAT('^')) {
+		EMIT(OBOL, 0);
+		p->g->iflags |= USEBOL;
+		p->g->nbol++;
+	}
+	while (MORE() && !SEETWO(end1, end2)) {
+		wasdollar = p_simp_re(p, first);
+		first = 0;
+	}
+	if (wasdollar) {	/* oops, that was a trailing anchor */
+		DROP(1);
+		EMIT(OEOL, 0);
+		p->g->iflags |= USEEOL;
+		p->g->neol++;
+	}
+
+	(void) REQUIRE(HERE() != start, REG_BADPAT);	/* require nonempty */
+}
+
+/*
+ * p_simp_re - parse a simple RE, an atom possibly followed by a repetition
+ */
+static int			/* was the simple RE an unbackslashed $? */
+p_simp_re(struct parse *p,
+    int starordinary)	/* is a leading * an ordinary character? */
+{
+	int c;
+	int count;
+	int count2;
+	sopno pos;
+	int i;
+	wint_t wc;
+	sopno subno;
+#define	BACKSL	(1<<CHAR_BIT)
+
+	pos = HERE();		/* repetition op, if any, covers from here */
+
+	assert(MORE());		/* caller should have ensured this */
+	c = GETNEXT();
+	if (c == '\\') {
+		(void) REQUIRE(MORE(), REG_EESCAPE);
+		c = BACKSL | GETNEXT();
+	}
+	switch (c) {
+	case '.':
+		if (p->g->cflags&REG_NEWLINE)
+			nonnewline(p);
+		else
+			EMIT(OANY, 0);
+		break;
+	case '[':
+		p_bracket(p);
+		break;
+	case BACKSL|'<':
+		EMIT(OBOW, 0);
+		break;
+	case BACKSL|'>':
+		EMIT(OEOW, 0);
+		break;
+	case BACKSL|'{':
+		SETERROR(REG_BADRPT);
+		break;
+	case BACKSL|'(':
+		p->g->nsub++;
+		subno = p->g->nsub;
+		if (subno < NPAREN)
+			p->pbegin[subno] = HERE();
+		EMIT(OLPAREN, subno);
+		/* the MORE here is an error heuristic */
+		if (MORE() && !SEETWO('\\', ')'))
+			p_bre(p, '\\', ')');
+		if (subno < NPAREN) {
+			p->pend[subno] = HERE();
+			assert(p->pend[subno] != 0);
+		}
+		EMIT(ORPAREN, subno);
+		(void) REQUIRE(EATTWO('\\', ')'), REG_EPAREN);
+		break;
+	case BACKSL|')':	/* should not get here -- must be user */
+	case BACKSL|'}':
+		SETERROR(REG_EPAREN);
+		break;
+	case BACKSL|'1':
+	case BACKSL|'2':
+	case BACKSL|'3':
+	case BACKSL|'4':
+	case BACKSL|'5':
+	case BACKSL|'6':
+	case BACKSL|'7':
+	case BACKSL|'8':
+	case BACKSL|'9':
+		i = (c&~BACKSL) - '0';
+		assert(i < NPAREN);
+		if (p->pend[i] != 0) {
+			assert(i <= p->g->nsub);
+			EMIT(OBACK_, i);
+			assert(p->pbegin[i] != 0);
+			assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
+			assert(OP(p->strip[p->pend[i]]) == ORPAREN);
+			(void) dupl(p, p->pbegin[i]+1, p->pend[i]);
+			EMIT(O_BACK, i);
+		} else
+			SETERROR(REG_ESUBREG);
+		p->g->backrefs = 1;
+		break;
+	case '*':
+		(void) REQUIRE(starordinary, REG_BADRPT);
+		/* FALLTHROUGH */
+	default:
+		if (p->error != 0)
+			return (0);	/* Definitely not $... */
+		p->next--;
+		wc = WGETNEXT();
+		ordinary(p, wc);
+		break;
+	}
+
+	if (EAT('*')) {		/* implemented as +? */
+		/* this case does not require the (y|) trick, noKLUDGE */
+		INSERT(OPLUS_, pos);
+		ASTERN(O_PLUS, pos);
+		INSERT(OQUEST_, pos);
+		ASTERN(O_QUEST, pos);
+	} else if (EATTWO('\\', '{')) {
+		count = p_count(p);
+		if (EAT(',')) {
+			if (MORE() && isdigit((uch)PEEK())) {
+				count2 = p_count(p);
+				(void) REQUIRE(count <= count2, REG_BADBR);
+			} else		/* single number with comma */
+				count2 = INFINITY;
+		} else		/* just a single number */
+			count2 = count;
+		repeat(p, pos, count, count2);
+		if (!EATTWO('\\', '}')) {	/* error heuristics */
+			while (MORE() && !SEETWO('\\', '}'))
+				NEXT();
+			(void) REQUIRE(MORE(), REG_EBRACE);
+			SETERROR(REG_BADBR);
+		}
+	} else if (c == '$')	/* $ (but not \$) ends it */
+		return (1);
+
+	return (0);
+}
+
+/*
+ * p_count - parse a repetition count
+ */
+static int			/* the value */
+p_count(struct parse *p)
+{
+	int count = 0;
+	int ndigits = 0;
+
+	while (MORE() && isdigit((uch)PEEK()) && count <= DUPMAX) {
+		count = count*10 + (GETNEXT() - '0');
+		ndigits++;
+	}
+
+	(void) REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
+	return (count);
+}
+
+/*
+ * p_bracket - parse a bracketed character list
+ */
+static void
+p_bracket(struct parse *p)
+{
+	cset *cs;
+	wint_t ch;
+
+	/* Dept of Truly Sickening Special-Case Kludges */
+	if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) {
+		EMIT(OBOW, 0);
+		NEXTn(6);
+		return;
+	}
+	if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) {
+		EMIT(OEOW, 0);
+		NEXTn(6);
+		return;
+	}
+
+	if ((cs = allocset(p)) == NULL)
+		return;
+
+	if (p->g->cflags&REG_ICASE)
+		cs->icase = 1;
+	if (EAT('^'))
+		cs->invert = 1;
+	if (EAT(']'))
+		CHadd(p, cs, ']');
+	else if (EAT('-'))
+		CHadd(p, cs, '-');
+	while (MORE() && PEEK() != ']' && !SEETWO('-', ']'))
+		p_b_term(p, cs);
+	if (EAT('-'))
+		CHadd(p, cs, '-');
+	(void) MUSTEAT(']', REG_EBRACK);
+
+	if (p->error != 0)	/* don't mess things up further */
+		return;
+
+	if (cs->invert && p->g->cflags&REG_NEWLINE)
+		cs->bmp['\n' >> 3] |= 1 << ('\n' & 7);
+
+	if ((ch = singleton(cs)) != OUT) {	/* optimize singleton sets */
+		ordinary(p, ch);
+		freeset(p, cs);
+	} else
+		EMIT(OANYOF, (int)(cs - p->g->sets));
+}
+
+/*
+ * p_b_term - parse one term of a bracketed character list
+ */
+static void
+p_b_term(struct parse *p, cset *cs)
+{
+	char c;
+	wint_t start, finish;
+	wint_t i;
+	locale_t loc = uselocale(NULL);
+
+	/* classify what we've got */
+	switch ((MORE()) ? PEEK() : '\0') {
+	case '[':
+		c = (MORE2()) ? PEEK2() : '\0';
+		break;
+	case '-':
+		SETERROR(REG_ERANGE);
+		return;			/* NOTE RETURN */
+	default:
+		c = '\0';
+		break;
+	}
+
+	switch (c) {
+	case ':':		/* character class */
+		NEXT2();
+		(void) REQUIRE(MORE(), REG_EBRACK);
+		c = PEEK();
+		(void) REQUIRE(c != '-' && c != ']', REG_ECTYPE);
+		p_b_cclass(p, cs);
+		(void) REQUIRE(MORE(), REG_EBRACK);
+		(void) REQUIRE(EATTWO(':', ']'), REG_ECTYPE);
+		break;
+	case '=':		/* equivalence class */
+		NEXT2();
+		(void) REQUIRE(MORE(), REG_EBRACK);
+		c = PEEK();
+		(void) REQUIRE(c != '-' && c != ']', REG_ECOLLATE);
+		p_b_eclass(p, cs);
+		(void) REQUIRE(MORE(), REG_EBRACK);
+		(void) REQUIRE(EATTWO('=', ']'), REG_ECOLLATE);
+		break;
+	default:		/* symbol, ordinary character, or range */
+		start = p_b_symbol(p);
+		if (SEE('-') && MORE2() && PEEK2() != ']') {
+			/* range */
+			NEXT();
+			if (EAT('-'))
+				finish = '-';
+			else
+				finish = p_b_symbol(p);
+		} else
+			finish = start;
+		if (start == finish)
+			CHadd(p, cs, start);
+		else {
+			if (loc->collate->lc_is_posix) {
+				(void) REQUIRE((uch)start <= (uch)finish,
+				    REG_ERANGE);
+				CHaddrange(p, cs, start, finish);
+			} else {
+				(void) REQUIRE(_collate_range_cmp(start,
+				    finish, loc) <= 0, REG_ERANGE);
+				for (i = 0; i <= UCHAR_MAX; i++) {
+					if (_collate_range_cmp(start, i, loc)
+					    <= 0 &&
+					    _collate_range_cmp(i, finish, loc)
+					    <= 0)
+						CHadd(p, cs, i);
+				}
+			}
+		}
+		break;
+	}
+}
+
+/*
+ * p_b_cclass - parse a character-class name and deal with it
+ */
+static void
+p_b_cclass(struct parse *p, cset *cs)
+{
+	const char *sp = p->next;
+	size_t len;
+	wctype_t wct;
+	char clname[16];
+
+	while (MORE() && isalpha((uch)PEEK()))
+		NEXT();
+	len = p->next - sp;
+	if (len >= sizeof (clname) - 1) {
+		SETERROR(REG_ECTYPE);
+		return;
+	}
+	(void) memcpy(clname, sp, len);
+	clname[len] = '\0';
+	if ((wct = wctype(clname)) == 0) {
+		SETERROR(REG_ECTYPE);
+		return;
+	}
+	CHaddtype(p, cs, wct);
+}
+
+/*
+ * p_b_eclass - parse an equivalence-class name and deal with it
+ *
+ * This implementation is incomplete. xxx
+ */
+static void
+p_b_eclass(struct parse *p, cset *cs)
+{
+	wint_t c;
+
+	c = p_b_coll_elem(p, '=');
+	CHadd(p, cs, c);
+}
+
+/*
+ * p_b_symbol - parse a character or [..]ed multicharacter collating symbol
+ */
+static wint_t			/* value of symbol */
+p_b_symbol(struct parse *p)
+{
+	wint_t value;
+
+	(void) REQUIRE(MORE(), REG_EBRACK);
+	if (!EATTWO('[', '.'))
+		return (WGETNEXT());
+
+	/* collating symbol */
+	value = p_b_coll_elem(p, '.');
+	(void) REQUIRE(EATTWO('.', ']'), REG_ECOLLATE);
+	return (value);
+}
+
+/*
+ * p_b_coll_elem - parse a collating-element name and look it up
+ */
+static wint_t			/* value of collating element */
+p_b_coll_elem(struct parse *p,
+    wint_t endc)		/* name ended by endc,']' */
+{
+	const char *sp = p->next;
+	struct cname *cp;
+	mbstate_t mbs;
+	wchar_t wc;
+	size_t clen, len;
+
+	while (MORE() && !SEETWO(endc, ']'))
+		NEXT();
+	if (!MORE()) {
+		SETERROR(REG_EBRACK);
+		return (0);
+	}
+	len = p->next - sp;
+	for (cp = cnames; cp->name != NULL; cp++)
+		if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
+			return (cp->code);	/* known name */
+	(void) memset(&mbs, 0, sizeof (mbs));
+	if ((clen = mbrtowc(&wc, sp, len, &mbs)) == len)
+		return (wc);			/* single character */
+	else if (clen == (size_t)-1 || clen == (size_t)-2)
+		SETERROR(REG_ECHAR);
+	else
+		SETERROR(REG_ECOLLATE);		/* neither */
+	return (0);
+}
+
+/*
+ * othercase - return the case counterpart of an alphabetic
+ */
+static wint_t			/* if no counterpart, return ch */
+othercase(wint_t ch)
+{
+	assert(iswalpha(ch));
+	if (iswupper(ch))
+		return (towlower(ch));
+	else if (iswlower(ch))
+		return (towupper(ch));
+	else			/* peculiar, but could happen */
+		return (ch);
+}
+
+/*
+ * bothcases - emit a dualcase version of a two-case character
+ *
+ * Boy, is this implementation ever a kludge...
+ */
+static void
+bothcases(struct parse *p, wint_t ch)
+{
+	const char *oldnext = p->next;
+	const char *oldend = p->end;
+	char bracket[3 + MB_LEN_MAX];
+	size_t n;
+	mbstate_t mbs;
+
+	assert(othercase(ch) != ch);	/* p_bracket() would recurse */
+	p->next = bracket;
+	(void) memset(&mbs, 0, sizeof (mbs));
+	n = wcrtomb(bracket, ch, &mbs);
+	assert(n != (size_t)-1);
+	bracket[n] = ']';
+	bracket[n + 1] = '\0';
+	p->end = bracket+n+1;
+	p_bracket(p);
+	assert(p->next == p->end);
+	p->next = oldnext;
+	p->end = oldend;
+}
+
+/*
+ * ordinary - emit an ordinary character
+ */
+static void
+ordinary(struct parse *p, wint_t ch)
+{
+	cset *cs;
+
+	if ((p->g->cflags&REG_ICASE) && iswalpha(ch) && othercase(ch) != ch)
+		bothcases(p, ch);
+	else if ((ch & OPDMASK) == ch)
+		EMIT(OCHAR, ch);
+	else {
+		/*
+		 * Kludge: character is too big to fit into an OCHAR operand.
+		 * Emit a singleton set.
+		 */
+		if ((cs = allocset(p)) == NULL)
+			return;
+		CHadd(p, cs, ch);
+		EMIT(OANYOF, (int)(cs - p->g->sets));
+	}
+}
+
+/*
+ * nonnewline - emit REG_NEWLINE version of OANY
+ *
+ * Boy, is this implementation ever a kludge...
+ */
+static void
+nonnewline(struct parse *p)
+{
+	const char *oldnext = p->next;
+	const char *oldend = p->end;
+	char bracket[4];
+
+	p->next = bracket;
+	p->end = bracket+3;
+	bracket[0] = '^';
+	bracket[1] = '\n';
+	bracket[2] = ']';
+	bracket[3] = '\0';
+	p_bracket(p);
+	assert(p->next == bracket+3);
+	p->next = oldnext;
+	p->end = oldend;
+}
+
+/*
+ * repeat - generate code for a bounded repetition, recursively if needed
+ */
+static void
+repeat(struct parse *p,
+    sopno start,		/* operand from here to end of strip */
+    int from,			/* repeated from this number */
+    int to)			/* to this number of times (maybe INFINITY) */
+{
+	sopno finish = HERE();
+#define	N	2
+#define	INF	3
+#define	REP(f, t)	((f)*8 + (t))
+#define	MAP(n)	(((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N)
+	sopno copy;
+
+	if (p->error != 0)	/* head off possible runaway recursion */
+		return;
+
+	assert(from <= to);
+
+	switch (REP(MAP(from), MAP(to))) {
+	case REP(0, 0):			/* must be user doing this */
+		DROP(finish-start);	/* drop the operand */
+		break;
+	case REP(0, 1):			/* as x{1,1}? */
+	case REP(0, N):			/* as x{1,n}? */
+	case REP(0, INF):		/* as x{1,}? */
+		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
+		INSERT(OCH_, start);		/* offset is wrong... */
+		repeat(p, start+1, 1, to);
+		ASTERN(OOR1, start);
+		AHEAD(start);			/* ... fix it */
+		EMIT(OOR2, 0);
+		AHEAD(THERE());
+		ASTERN(O_CH, THERETHERE());
+		break;
+	case REP(1, 1):			/* trivial case */
+		/* done */
+		break;
+	case REP(1, N):			/* as x?x{1,n-1} */
+		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
+		INSERT(OCH_, start);
+		ASTERN(OOR1, start);
+		AHEAD(start);
+		EMIT(OOR2, 0);			/* offset very wrong... */
+		AHEAD(THERE());			/* ...so fix it */
+		ASTERN(O_CH, THERETHERE());
+		copy = dupl(p, start+1, finish+1);
+		assert(copy == finish+4);
+		repeat(p, copy, 1, to-1);
+		break;
+	case REP(1, INF):		/* as x+ */
+		INSERT(OPLUS_, start);
+		ASTERN(O_PLUS, start);
+		break;
+	case REP(N, N):			/* as xx{m-1,n-1} */
+		copy = dupl(p, start, finish);
+		repeat(p, copy, from-1, to-1);
+		break;
+	case REP(N, INF):		/* as xx{n-1,INF} */
+		copy = dupl(p, start, finish);
+		repeat(p, copy, from-1, to);
+		break;
+	default:			/* "can't happen" */
+		SETERROR(REG_EFATAL);	/* just in case */
+		break;
+	}
+}
+
+/*
+ * wgetnext - helper function for WGETNEXT() macro. Gets the next wide
+ * character from the parse struct, signals a REG_ILLSEQ error if the
+ * character can't be converted. Returns the number of bytes consumed.
+ */
+static wint_t
+wgetnext(struct parse *p)
+{
+	mbstate_t mbs;
+	wchar_t wc;
+	size_t n;
+
+	(void) memset(&mbs, 0, sizeof (mbs));
+	n = mbrtowc(&wc, p->next, p->end - p->next, &mbs);
+	if (n == (size_t)-1 || n == (size_t)-2) {
+		SETERROR(REG_ECHAR);
+		return (0);
+	}
+	if (n == 0)
+		n = 1;
+	p->next += n;
+	return (wc);
+}
+
+/*
+ * seterr - set an error condition
+ */
+static int			/* useless but makes type checking happy */
+seterr(struct parse *p, int e)
+{
+	if (p->error == 0)	/* keep earliest error condition */
+		p->error = e;
+	p->next = nuls;		/* try to bring things to a halt */
+	p->end = nuls;
+	return (0);		/* make the return value well-defined */
+}
+
+/*
+ * allocset - allocate a set of characters for []
+ */
+static cset *
+allocset(struct parse *p)
+{
+	cset *cs, *ncs;
+
+	ncs = realloc(p->g->sets, (p->g->ncsets + 1) * sizeof (*ncs));
+	if (ncs == NULL) {
+		SETERROR(REG_ESPACE);
+		return (NULL);
+	}
+	p->g->sets = ncs;
+	cs = &p->g->sets[p->g->ncsets++];
+	(void) memset(cs, 0, sizeof (*cs));
+
+	return (cs);
+}
+
+/*
+ * freeset - free a now-unused set
+ */
+static void
+freeset(struct parse *p, cset *cs)
+{
+	cset *top = &p->g->sets[p->g->ncsets];
+
+	free(cs->wides);
+	free(cs->ranges);
+	free(cs->types);
+	(void) memset(cs, 0, sizeof (*cs));
+	if (cs == top-1)	/* recover only the easy case */
+		p->g->ncsets--;
+}
+
+/*
+ * singleton - Determine whether a set contains only one character,
+ * returning it if so, otherwise returning OUT.
+ */
+static wint_t
+singleton(cset *cs)
+{
+	wint_t i, s, n;
+
+	for (i = n = 0; i < NC; i++)
+		if (CHIN(cs, i)) {
+			n++;
+			s = i;
+		}
+	if (n == 1)
+		return (s);
+	if (cs->nwides == 1 && cs->nranges == 0 && cs->ntypes == 0 &&
+	    cs->icase == 0)
+		return (cs->wides[0]);
+	/* Don't bother handling the other cases. */
+	return (OUT);
+}
+
+/*
+ * CHadd - add character to character set.
+ */
+static void
+CHadd(struct parse *p, cset *cs, wint_t ch)
+{
+	wint_t nch, *newwides;
+	assert(ch >= 0);
+	if (ch < NC)
+		cs->bmp[ch >> 3] |= 1 << (ch & 7);
+	else {
+		newwides = realloc(cs->wides, (cs->nwides + 1) *
+		    sizeof (*cs->wides));
+		if (newwides == NULL) {
+			SETERROR(REG_ESPACE);
+			return;
+		}
+		cs->wides = newwides;
+		cs->wides[cs->nwides++] = ch;
+	}
+	if (cs->icase) {
+		if ((nch = towlower(ch)) < NC)
+			cs->bmp[nch >> 3] |= 1 << (nch & 7);
+		if ((nch = towupper(ch)) < NC)
+			cs->bmp[nch >> 3] |= 1 << (nch & 7);
+	}
+}
+
+/*
+ * CHaddrange - add all characters in the range [min,max] to a character set.
+ */
+static void
+CHaddrange(struct parse *p, cset *cs, wint_t min, wint_t max)
+{
+	crange *newranges;
+
+	for (; min < NC && min <= max; min++)
+		CHadd(p, cs, min);
+	if (min >= max)
+		return;
+	newranges = realloc(cs->ranges, (cs->nranges + 1) *
+	    sizeof (*cs->ranges));
+	if (newranges == NULL) {
+		SETERROR(REG_ESPACE);
+		return;
+	}
+	cs->ranges = newranges;
+	cs->ranges[cs->nranges].min = min;
+	cs->ranges[cs->nranges].max = max;
+	cs->nranges++;
+}
+
+/*
+ * CHaddtype - add all characters of a certain type to a character set.
+ */
+static void
+CHaddtype(struct parse *p, cset *cs, wctype_t wct)
+{
+	wint_t i;
+	wctype_t *newtypes;
+
+	for (i = 0; i < NC; i++)
+		if (iswctype(i, wct))
+			CHadd(p, cs, i);
+	newtypes = realloc(cs->types, (cs->ntypes + 1) *
+	    sizeof (*cs->types));
+	if (newtypes == NULL) {
+		SETERROR(REG_ESPACE);
+		return;
+	}
+	cs->types = newtypes;
+	cs->types[cs->ntypes++] = wct;
+}
+
+/*
+ * dupl - emit a duplicate of a bunch of sops
+ */
+static sopno			/* start of duplicate */
+dupl(struct parse *p,
+    sopno start,		/* from here */
+    sopno finish)		/* to this less one */
+{
+	sopno ret = HERE();
+	sopno len = finish - start;
+
+	assert(finish >= start);
+	if (len == 0)
+		return (ret);
+	if (!enlarge(p, p->ssize + len)) /* this many unexpected additions */
+		return (ret);
+	assert(p->ssize >= p->slen + len);
+	(void) memcpy((char *)(p->strip + p->slen),
+	    (char *)(p->strip + start), (size_t)len*sizeof (sop));
+	p->slen += len;
+	return (ret);
+}
+
+/*
+ * doemit - emit a strip operator
+ *
+ * It might seem better to implement this as a macro with a function as
+ * hard-case backup, but it's just too big and messy unless there are
+ * some changes to the data structures.  Maybe later.
+ */
+static void
+doemit(struct parse *p, sop op, size_t opnd)
+{
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	/* deal with oversize operands ("can't happen", more or less) */
+	assert(opnd < 1<<OPSHIFT);
+
+	/* deal with undersized strip */
+	if (p->slen >= p->ssize)
+		if (!enlarge(p, (p->ssize+1) / 2 * 3))	/* +50% */
+			return;
+
+	/* finally, it's all reduced to the easy case */
+	p->strip[p->slen++] = SOP(op, opnd);
+}
+
+/*
+ * doinsert - insert a sop into the strip
+ */
+static void
+doinsert(struct parse *p, sop op, size_t opnd, sopno pos)
+{
+	sopno sn;
+	sop s;
+	int i;
+
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	sn = HERE();
+	EMIT(op, opnd);		/* do checks, ensure space */
+	assert(HERE() == sn+1);
+	s = p->strip[sn];
+
+	/* adjust paren pointers */
+	assert(pos > 0);
+	for (i = 1; i < NPAREN; i++) {
+		if (p->pbegin[i] >= pos) {
+			p->pbegin[i]++;
+		}
+		if (p->pend[i] >= pos) {
+			p->pend[i]++;
+		}
+	}
+
+	(void) memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos],
+	    (HERE()-pos-1)*sizeof (sop));
+	p->strip[pos] = s;
+}
+
+/*
+ * dofwd - complete a forward reference
+ */
+static void
+dofwd(struct parse *p, sopno pos, sop value)
+{
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	assert(value < 1<<OPSHIFT);
+	p->strip[pos] = OP(p->strip[pos]) | value;
+}
+
+/*
+ * enlarge - enlarge the strip
+ */
+static int
+enlarge(struct parse *p, sopno size)
+{
+	sop *sp;
+
+	if (p->ssize >= size)
+		return (1);
+
+	sp = (sop *)realloc(p->strip, size*sizeof (sop));
+	if (sp == NULL) {
+		SETERROR(REG_ESPACE);
+		return (0);
+	}
+	p->strip = sp;
+	p->ssize = size;
+	return (1);
+}
+
+/*
+ * stripsnug - compact the strip
+ */
+static void
+stripsnug(struct parse *p, struct re_guts *g)
+{
+	g->nstates = p->slen;
+	g->strip = (sop *)realloc((char *)p->strip, p->slen * sizeof (sop));
+	if (g->strip == NULL) {
+		SETERROR(REG_ESPACE);
+		g->strip = p->strip;
+	}
+}
+
+/*
+ * findmust - fill in must and mlen with longest mandatory literal string
+ *
+ * This algorithm could do fancy things like analyzing the operands of |
+ * for common subsequences.  Someday.  This code is simple and finds most
+ * of the interesting cases.
+ *
+ * Note that must and mlen got initialized during setup.
+ */
+static void
+findmust(struct parse *p, struct re_guts *g)
+{
+	sop *scan;
+	sop *start = NULL;
+	sop *newstart = NULL;
+	sopno newlen;
+	sop s;
+	char *cp;
+	int offset;
+	char buf[MB_LEN_MAX];
+	size_t clen;
+	mbstate_t mbs;
+	locale_t loc = uselocale(NULL);
+
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	/*
+	 * It's not generally safe to do a ``char'' substring search on
+	 * multibyte character strings, but it's safe for at least
+	 * UTF-8 (see RFC 3629).
+	 */
+	if (MB_CUR_MAX > 1 &&
+	    strcmp(loc->runelocale->__encoding, "UTF-8") != 0)
+		return;
+
+	/* find the longest OCHAR sequence in strip */
+	newlen = 0;
+	offset = 0;
+	g->moffset = 0;
+	scan = g->strip + 1;
+	do {
+		s = *scan++;
+		switch (OP(s)) {
+		case OCHAR:		/* sequence member */
+			if (newlen == 0) {		/* new sequence */
+				(void) memset(&mbs, 0, sizeof (mbs));
+				newstart = scan - 1;
+			}
+			clen = wcrtomb(buf, OPND(s), &mbs);
+			if (clen == (size_t)-1)
+				goto toohard;
+			newlen += clen;
+			break;
+		case OPLUS_:		/* things that don't break one */
+		case OLPAREN:
+		case ORPAREN:
+			break;
+		case OQUEST_:		/* things that must be skipped */
+		case OCH_:
+			offset = altoffset(scan, offset);
+			scan--;
+			do {
+				scan += OPND(s);
+				s = *scan;
+				/* assert() interferes w debug printouts */
+				if (OP(s) != O_QUEST && OP(s) != O_CH &&
+				    OP(s) != OOR2) {
+					g->iflags |= BAD;
+					return;
+				}
+			} while (OP(s) != O_QUEST && OP(s) != O_CH);
+			/* FALLTHROUGH */
+		case OBOW:		/* things that break a sequence */
+		case OEOW:
+		case OBOL:
+		case OEOL:
+		case O_QUEST:
+		case O_CH:
+		case OEND:
+			if (newlen > g->mlen) {		/* ends one */
+				start = newstart;
+				g->mlen = newlen;
+				if (offset > -1) {
+					g->moffset += offset;
+					offset = newlen;
+				} else
+					g->moffset = offset;
+			} else {
+				if (offset > -1)
+					offset += newlen;
+			}
+			newlen = 0;
+			break;
+		case OANY:
+			if (newlen > g->mlen) {		/* ends one */
+				start = newstart;
+				g->mlen = newlen;
+				if (offset > -1) {
+					g->moffset += offset;
+					offset = newlen;
+				} else
+					g->moffset = offset;
+			} else {
+				if (offset > -1)
+					offset += newlen;
+			}
+			if (offset > -1)
+				offset++;
+			newlen = 0;
+			break;
+		case OANYOF:		/* may or may not invalidate offset */
+			/* First, everything as OANY */
+			if (newlen > g->mlen) {		/* ends one */
+				start = newstart;
+				g->mlen = newlen;
+				if (offset > -1) {
+					g->moffset += offset;
+					offset = newlen;
+				} else
+					g->moffset = offset;
+			} else {
+				if (offset > -1)
+					offset += newlen;
+			}
+			if (offset > -1)
+				offset++;
+			newlen = 0;
+			break;
+		toohard:
+		default:
+			/*
+			 * Anything here makes it impossible or too hard
+			 * to calculate the offset -- so we give up;
+			 * save the last known good offset, in case the
+			 * must sequence doesn't occur later.
+			 */
+			if (newlen > g->mlen) {		/* ends one */
+				start = newstart;
+				g->mlen = newlen;
+				if (offset > -1)
+					g->moffset += offset;
+				else
+					g->moffset = offset;
+			}
+			offset = -1;
+			newlen = 0;
+			break;
+		}
+	} while (OP(s) != OEND);
+
+	if (g->mlen == 0) {		/* there isn't one */
+		g->moffset = -1;
+		return;
+	}
+
+	/* turn it into a character string */
+	g->must = malloc((size_t)g->mlen + 1);
+	if (g->must == NULL) {		/* argh; just forget it */
+		g->mlen = 0;
+		g->moffset = -1;
+		return;
+	}
+	cp = g->must;
+	scan = start;
+	(void) memset(&mbs, 0, sizeof (mbs));
+	while (cp < g->must + g->mlen) {
+		while (OP(s = *scan++) != OCHAR)
+			continue;
+		clen = wcrtomb(cp, OPND(s), &mbs);
+		assert(clen != (size_t)-1);
+		cp += clen;
+	}
+	assert(cp == g->must + g->mlen);
+	*cp++ = '\0';		/* just on general principles */
+}
+
+/*
+ * altoffset - choose biggest offset among multiple choices
+ *
+ * Compute, recursively if necessary, the largest offset among multiple
+ * re paths.
+ */
+static int
+altoffset(sop *scan, int offset)
+{
+	int largest;
+	int try;
+	sop s;
+
+	/* If we gave up already on offsets, return */
+	if (offset == -1)
+		return (-1);
+
+	largest = 0;
+	try = 0;
+	s = *scan++;
+	while (OP(s) != O_QUEST && OP(s) != O_CH) {
+		switch (OP(s)) {
+		case OOR1:
+			if (try > largest)
+				largest = try;
+			try = 0;
+			break;
+		case OQUEST_:
+		case OCH_:
+			try = altoffset(scan, try);
+			if (try == -1)
+				return (-1);
+			scan--;
+			do {
+				scan += OPND(s);
+				s = *scan;
+				if (OP(s) != O_QUEST && OP(s) != O_CH &&
+				    OP(s) != OOR2)
+					return (-1);
+			} while (OP(s) != O_QUEST && OP(s) != O_CH);
+			/*
+			 * We must skip to the next position, or we'll
+			 * leave altoffset() too early.
+			 */
+			scan++;
+			break;
+		case OANYOF:
+		case OCHAR:
+		case OANY:
+			try++;
+			/*FALLTHRU*/
+		case OBOW:
+		case OEOW:
+		case OLPAREN:
+		case ORPAREN:
+		case OOR2:
+			break;
+		default:
+			try = -1;
+			break;
+		}
+		if (try == -1)
+			return (-1);
+		s = *scan++;
+	}
+
+	if (try > largest)
+		largest = try;
+
+	return (largest+offset);
+}
+
+/*
+ * computejumps - compute char jumps for BM scan
+ *
+ * This algorithm assumes g->must exists and is has size greater than
+ * zero. It's based on the algorithm found on Computer Algorithms by
+ * Sara Baase.
+ *
+ * A char jump is the number of characters one needs to jump based on
+ * the value of the character from the text that was mismatched.
+ */
+static void
+computejumps(struct parse *p, struct re_guts *g)
+{
+	int ch;
+	int mindex;
+
+	/* Avoid making errors worse */
+	if (p->error != 0)
+		return;
+
+	g->charjump = (int *)malloc((NC + 1) * sizeof (int));
+	if (g->charjump == NULL)	/* Not a fatal error */
+		return;
+	/* Adjust for signed chars, if necessary */
+	g->charjump = &g->charjump[-(CHAR_MIN)];
+
+	/*
+	 * If the character does not exist in the pattern, the jump
+	 * is equal to the number of characters in the pattern.
+	 */
+	for (ch = CHAR_MIN; ch < (CHAR_MAX + 1); ch++)
+		g->charjump[ch] = g->mlen;
+
+	/*
+	 * If the character does exist, compute the jump that would
+	 * take us to the last character in the pattern equal to it
+	 * (notice that we match right to left, so that last character
+	 * is the first one that would be matched).
+	 */
+	for (mindex = 0; mindex < g->mlen; mindex++)
+		g->charjump[(int)g->must[mindex]] = g->mlen - mindex - 1;
+}
+
+/*
+ * computematchjumps - compute match jumps for BM scan
+ *
+ * This algorithm assumes g->must exists and is has size greater than
+ * zero. It's based on the algorithm found on Computer Algorithms by
+ * Sara Baase.
+ *
+ * A match jump is the number of characters one needs to advance based
+ * on the already-matched suffix.
+ * Notice that all values here are minus (g->mlen-1), because of the way
+ * the search algorithm works.
+ */
+static void
+computematchjumps(struct parse *p, struct re_guts *g)
+{
+	int mindex;		/* General "must" iterator */
+	int suffix;		/* Keeps track of matching suffix */
+	int ssuffix;		/* Keeps track of suffixes' suffix */
+	int *pmatches;
+				/*
+				 * pmatches[k] points to the next i
+				 * such that i+1...mlen is a substring
+				 * of k+1...k+mlen-i-1
+				 */
+
+	/* Avoid making errors worse */
+	if (p->error != 0)
+		return;
+
+	pmatches = (int *)malloc(g->mlen * sizeof (unsigned int));
+	if (pmatches == NULL) {
+		g->matchjump = NULL;
+		return;
+	}
+
+	g->matchjump = (int *)malloc(g->mlen * sizeof (unsigned int));
+	if (g->matchjump == NULL) {	/* Not a fatal error */
+		free(pmatches);
+		return;
+	}
+
+	/* Set maximum possible jump for each character in the pattern */
+	for (mindex = 0; mindex < g->mlen; mindex++)
+		g->matchjump[mindex] = 2*g->mlen - mindex - 1;
+
+	/* Compute pmatches[] */
+	for (mindex = g->mlen - 1, suffix = g->mlen; mindex >= 0;
+	    mindex--, suffix--) {
+		pmatches[mindex] = suffix;
+
+		/*
+		 * If a mismatch is found, interrupting the substring,
+		 * compute the matchjump for that position. If no
+		 * mismatch is found, then a text substring mismatched
+		 * against the suffix will also mismatch against the
+		 * substring.
+		 */
+		while (suffix < g->mlen && g->must[mindex] != g->must[suffix]) {
+			g->matchjump[suffix] = MIN(g->matchjump[suffix],
+			    g->mlen - mindex - 1);
+			suffix = pmatches[suffix];
+		}
+	}
+
+	/*
+	 * Compute the matchjump up to the last substring found to jump
+	 * to the beginning of the largest must pattern prefix matching
+	 * it's own suffix.
+	 */
+	for (mindex = 0; mindex <= suffix; mindex++)
+		g->matchjump[mindex] = MIN(g->matchjump[mindex],
+		    g->mlen + suffix - mindex);
+
+	ssuffix = pmatches[suffix];
+	while (suffix < g->mlen) {
+		while (suffix <= ssuffix && suffix < g->mlen) {
+			g->matchjump[suffix] = MIN(g->matchjump[suffix],
+			    g->mlen + ssuffix - suffix);
+			suffix++;
+		}
+		if (suffix < g->mlen)
+			ssuffix = pmatches[ssuffix];
+	}
+
+	free(pmatches);
+}
+
+/*
+ * pluscount - count + nesting
+ */
+static sopno			/* nesting depth */
+pluscount(struct parse *p, struct re_guts *g)
+{
+	sop *scan;
+	sop s;
+	sopno plusnest = 0;
+	sopno maxnest = 0;
+
+	if (p->error != 0)
+		return (0);	/* there may not be an OEND */
+
+	scan = g->strip + 1;
+	do {
+		s = *scan++;
+		switch (OP(s)) {
+		case OPLUS_:
+			plusnest++;
+			break;
+		case O_PLUS:
+			if (plusnest > maxnest)
+				maxnest = plusnest;
+			plusnest--;
+			break;
+		}
+	} while (OP(s) != OEND);
+	if (plusnest != 0)
+		g->iflags |= BAD;
+	return (maxnest);
+}