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phunix/lib/libc/regex/engine.c
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify. 
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

1189 lines
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/* $NetBSD: engine.c,v 1.22 2009/02/12 05:06:54 lukem Exp $ */
/*-
* 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.
*
* @(#)engine.c 8.5 (Berkeley) 3/20/94
*/
/*-
* Copyright (c) 1992, 1993, 1994 Henry Spencer.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* @(#)engine.c 8.5 (Berkeley) 3/20/94
*/
/*
* The matching engine and friends. This file is #included by regexec.c
* after suitable #defines of a variety of macros used herein, so that
* different state representations can be used without duplicating masses
* of code.
*/
#ifdef SNAMES
#define matcher smatcher
#define fast sfast
#define slow sslow
#define dissect sdissect
#define backref sbackref
#define step sstep
#define print sprint
#define at sat
#define match smat
#define nope snope
#endif
#ifdef LNAMES
#define matcher lmatcher
#define fast lfast
#define slow lslow
#define dissect ldissect
#define backref lbackref
#define step lstep
#define print lprint
#define at lat
#define match lmat
#define nope lnope
#endif
/* another structure passed up and down to avoid zillions of parameters */
struct match {
struct re_guts *g;
int eflags;
regmatch_t *pmatch; /* [nsub+1] (0 element unused) */
const char *offp; /* offsets work from here */
const char *beginp; /* start of string -- virtual NUL precedes */
const char *endp; /* end of string -- virtual NUL here */
const char *coldp; /* can be no match starting before here */
const char **lastpos; /* [nplus+1] */
STATEVARS;
states st; /* current states */
states fresh; /* states for a fresh start */
states tmp; /* temporary */
states empty; /* empty set of states */
};
/* ========= begin header generated by ./mkh ========= */
#ifdef __cplusplus
extern "C" {
#endif
/* === engine.c === */
static int matcher(struct re_guts *g, const char *string, size_t nmatch, regmatch_t pmatch[], int eflags);
static const char *dissect(struct match *m, const char *start, const char *stop, sopno startst, sopno stopst);
static const char *backref(struct match *m, const char *start, const char *stop, sopno startst, sopno stopst, sopno lev);
static const char *fast(struct match *m, const char *start, const char *stop, sopno startst, sopno stopst);
static const char *slow(struct match *m, const char *start, const char *stop, sopno startst, sopno stopst);
static states step(struct re_guts *g, sopno start, sopno stop, states bef, int ch, states aft);
#define BOL (OUT+1)
#define EOL (BOL+1)
#define BOLEOL (BOL+2)
#define NOTHING (BOL+3)
#define BOW (BOL+4)
#define EOW (BOL+5)
#define CODEMAX (BOL+5) /* highest code used */
#define NONCHAR(c) ((c) > CHAR_MAX)
#define NNONCHAR (CODEMAX-CHAR_MAX)
#ifdef REDEBUG
static void print(struct match *m, char *caption, states st, int ch, FILE *d);
#endif
#ifdef REDEBUG
static void at(struct match *m, char *title, char *start, char *stop, sopno startst, sopno stopst);
#endif
#ifdef REDEBUG
static char *pchar(int ch);
#endif
#ifdef __cplusplus
}
#endif
/* ========= end header generated by ./mkh ========= */
#ifdef REDEBUG
#define SP(t, s, c) print(m, t, s, c, stdout)
#define AT(t, p1, p2, s1, s2) at(m, t, p1, p2, s1, s2)
#define NOTE(str) { if (m->eflags&REG_TRACE) printf("=%s\n", (str)); }
static int nope = 0;
#else
#define SP(t, s, c) /* nothing */
#define AT(t, p1, p2, s1, s2) /* nothing */
#define NOTE(s) /* nothing */
#endif
/*
- matcher - the actual matching engine
== static int matcher(struct re_guts *g, char *string, \
== size_t nmatch, regmatch_t pmatch[], int eflags);
*/
static int /* 0 success, REG_NOMATCH failure */
matcher(
struct re_guts *g,
const char *string,
size_t nmatch,
regmatch_t pmatch[],
int eflags)
{
const char *endp;
size_t i;
struct match mv;
struct match *m = &mv;
const char *dp;
const sopno gf = g->firststate+1; /* +1 for OEND */
const sopno gl = g->laststate;
const char *start;
const char *stop;
int error = 0;
_DIAGASSERT(g != NULL);
_DIAGASSERT(string != NULL);
/* pmatch checked below */
/* simplify the situation where possible */
if (g->cflags&REG_NOSUB)
nmatch = 0;
if (eflags&REG_STARTEND) {
_DIAGASSERT(pmatch != NULL);
start = string + (size_t)pmatch[0].rm_so;
stop = string + (size_t)pmatch[0].rm_eo;
} else {
start = string;
stop = start + strlen(start);
}
if (stop < start)
return(REG_INVARG);
/* prescreening; this does wonders for this rather slow code */
if (g->must != NULL) {
for (dp = start; dp < stop; dp++)
if (*dp == g->must[0] && stop - dp >= g->mlen &&
memcmp(dp, g->must, (size_t)g->mlen) == 0)
break;
if (dp == stop) /* we didn't find g->must */
return(REG_NOMATCH);
}
/* match struct setup */
m->g = g;
m->eflags = eflags;
m->pmatch = NULL;
m->lastpos = NULL;
m->offp = string;
m->beginp = start;
m->endp = stop;
STATESETUP(m, 4);
SETUP(m->st);
SETUP(m->fresh);
SETUP(m->tmp);
SETUP(m->empty);
CLEAR(m->empty);
/* this loop does only one repetition except for backrefs */
for (;;) {
endp = fast(m, start, stop, gf, gl);
if (endp == NULL) { /* a miss */
error = REG_NOMATCH;
goto done;
}
if (nmatch == 0 && !g->backrefs)
break; /* no further info needed */
/* where? */
assert(m->coldp != NULL);
for (;;) {
NOTE("finding start");
endp = slow(m, m->coldp, stop, gf, gl);
if (endp != NULL)
break;
assert(m->coldp < m->endp);
m->coldp++;
}
if (nmatch == 1 && !g->backrefs)
break; /* no further info needed */
/* oh my, he wants the subexpressions... */
if (m->pmatch == NULL)
m->pmatch = (regmatch_t *)malloc((m->g->nsub + 1) *
sizeof(regmatch_t));
if (m->pmatch == NULL) {
error = REG_ESPACE;
goto done;
}
for (i = 1; i <= m->g->nsub; i++)
m->pmatch[i].rm_so = m->pmatch[i].rm_eo = (regoff_t)-1;
if (!g->backrefs && !(m->eflags&REG_BACKR)) {
NOTE("dissecting");
dp = dissect(m, m->coldp, endp, gf, gl);
} else {
if (g->nplus > 0 && m->lastpos == NULL)
m->lastpos = malloc((g->nplus+1) *
sizeof(const char *));
if (g->nplus > 0 && m->lastpos == NULL) {
error = REG_ESPACE;
goto done;
}
NOTE("backref dissect");
dp = backref(m, m->coldp, endp, gf, gl, (sopno)0);
}
if (dp != NULL)
break;
/* uh-oh... we couldn't find a subexpression-level match */
assert(g->backrefs); /* must be back references doing it */
assert(g->nplus == 0 || m->lastpos != NULL);
for (;;) {
if (dp != NULL || endp <= m->coldp)
break; /* defeat */
NOTE("backoff");
endp = slow(m, m->coldp, endp-1, gf, gl);
if (endp == NULL)
break; /* defeat */
/* try it on a shorter possibility */
#ifndef NDEBUG
for (i = 1; i <= m->g->nsub; i++) {
assert(m->pmatch[i].rm_so == (regoff_t)-1);
assert(m->pmatch[i].rm_eo == (regoff_t)-1);
}
#endif
NOTE("backoff dissect");
dp = backref(m, m->coldp, endp, gf, gl, (sopno)0);
}
assert(dp == NULL || dp == endp);
if (dp != NULL) /* found a shorter one */
break;
/* despite initial appearances, there is no match here */
NOTE("false alarm");
start = m->coldp + 1; /* recycle starting later */
assert(start <= stop);
}
/* fill in the details if requested */
if (nmatch > 0) {
_DIAGASSERT(pmatch != NULL);
pmatch[0].rm_so = m->coldp - m->offp;
pmatch[0].rm_eo = endp - m->offp;
}
if (nmatch > 1) {
assert(m->pmatch != NULL);
for (i = 1; i < nmatch; i++)
if (i <= m->g->nsub)
pmatch[i] = m->pmatch[i];
else {
pmatch[i].rm_so = (regoff_t)-1;
pmatch[i].rm_eo = (regoff_t)-1;
}
}
done:
if (m->pmatch != NULL) {
free(m->pmatch);
m->pmatch = NULL;
}
if (m->lastpos != NULL) {
free(m->lastpos);
m->lastpos = NULL;
}
STATETEARDOWN(m);
return error;
}
/*
- dissect - figure out what matched what, no back references
== static const char *dissect(struct match *m, const char *start, \
== const char *stop, sopno startst, sopno stopst);
*/
static const char * /* == stop (success) always */
dissect(
struct match *m,
const char *start,
const char *stop,
sopno startst,
sopno stopst)
{
int i;
sopno ss; /* start sop of current subRE */
sopno es; /* end sop of current subRE */
const char *sp; /* start of string matched by it */
const char *stp; /* string matched by it cannot pass here */
const char *rest; /* start of rest of string */
const char *tail; /* string unmatched by rest of RE */
sopno ssub; /* start sop of subsubRE */
sopno esub; /* end sop of subsubRE */
const char *ssp; /* start of string matched by subsubRE */
const char *sep; /* end of string matched by subsubRE */
const char *oldssp; /* previous ssp */
#ifndef NDEBUG
const char *dp;
#endif
_DIAGASSERT(m != NULL);
_DIAGASSERT(start != NULL);
_DIAGASSERT(stop != NULL);
AT("diss", start, stop, startst, stopst);
sp = start;
for (ss = startst; ss < stopst; ss = es) {
/* identify end of subRE */
es = ss;
switch (OP(m->g->strip[es])) {
case OPLUS_:
case OQUEST_:
es += OPND(m->g->strip[es]);
break;
case OCH_:
while (OP(m->g->strip[es]) != O_CH)
es += OPND(m->g->strip[es]);
break;
}
es++;
/* figure out what it matched */
switch (OP(m->g->strip[ss])) {
case OEND:
assert(nope);
break;
case OCHAR:
sp++;
break;
case OBOL:
case OEOL:
case OBOW:
case OEOW:
break;
case OANY:
case OANYOF:
sp++;
break;
case OBACK_:
case O_BACK:
assert(nope);
break;
/* cases where length of match is hard to find */
case OQUEST_:
stp = stop;
for (;;) {
/* how long could this one be? */
rest = slow(m, sp, stp, ss, es);
assert(rest != NULL); /* it did match */
/* could the rest match the rest? */
tail = slow(m, rest, stop, es, stopst);
if (tail == stop)
break; /* yes! */
/* no -- try a shorter match for this one */
stp = rest - 1;
assert(stp >= sp); /* it did work */
}
ssub = ss + 1;
esub = es - 1;
/* did innards match? */
if (slow(m, sp, rest, ssub, esub) != NULL) {
#ifdef NDEBUG
(void)
#else
dp =
#endif
dissect(m, sp, rest, ssub, esub);
assert(dp == rest);
} else /* no */
assert(sp == rest);
sp = rest;
break;
case OPLUS_:
stp = stop;
for (;;) {
/* how long could this one be? */
rest = slow(m, sp, stp, ss, es);
assert(rest != NULL); /* it did match */
/* could the rest match the rest? */
tail = slow(m, rest, stop, es, stopst);
if (tail == stop)
break; /* yes! */
/* no -- try a shorter match for this one */
stp = rest - 1;
assert(stp >= sp); /* it did work */
}
ssub = ss + 1;
esub = es - 1;
ssp = sp;
oldssp = ssp;
for (;;) { /* find last match of innards */
sep = slow(m, ssp, rest, ssub, esub);
if (sep == NULL || sep == ssp)
break; /* failed or matched null */
oldssp = ssp; /* on to next try */
ssp = sep;
}
if (sep == NULL) {
/* last successful match */
sep = ssp;
ssp = oldssp;
}
assert(sep == rest); /* must exhaust substring */
assert(slow(m, ssp, sep, ssub, esub) == rest);
#ifdef NDEBUG
(void)
#else
dp =
#endif
dissect(m, ssp, sep, ssub, esub);
assert(dp == sep);
sp = rest;
break;
case OCH_:
stp = stop;
for (;;) {
/* how long could this one be? */
rest = slow(m, sp, stp, ss, es);
assert(rest != NULL); /* it did match */
/* could the rest match the rest? */
tail = slow(m, rest, stop, es, stopst);
if (tail == stop)
break; /* yes! */
/* no -- try a shorter match for this one */
stp = rest - 1;
assert(stp >= sp); /* it did work */
}
ssub = ss + 1;
esub = ss + OPND(m->g->strip[ss]) - 1;
assert(OP(m->g->strip[esub]) == OOR1);
for (;;) { /* find first matching branch */
if (slow(m, sp, rest, ssub, esub) == rest)
break; /* it matched all of it */
/* that one missed, try next one */
assert(OP(m->g->strip[esub]) == OOR1);
esub++;
assert(OP(m->g->strip[esub]) == OOR2);
ssub = esub + 1;
esub += OPND(m->g->strip[esub]);
if (OP(m->g->strip[esub]) == OOR2)
esub--;
else
assert(OP(m->g->strip[esub]) == O_CH);
}
#ifdef NDEBUG
(void)
#else
dp =
#endif
dissect(m, sp, rest, ssub, esub);
assert(dp == rest);
sp = rest;
break;
case O_PLUS:
case O_QUEST:
case OOR1:
case OOR2:
case O_CH:
assert(nope);
break;
case OLPAREN:
i = OPND(m->g->strip[ss]);
assert(0 < i && i <= m->g->nsub);
m->pmatch[i].rm_so = sp - m->offp;
break;
case ORPAREN:
i = OPND(m->g->strip[ss]);
assert(0 < i && i <= m->g->nsub);
m->pmatch[i].rm_eo = sp - m->offp;
break;
default: /* uh oh */
assert(nope);
break;
}
}
assert(sp == stop);
return(sp);
}
/*
- backref - figure out what matched what, figuring in back references
== static const char *backref(struct match *m, const char *start, \
== const char *stop, sopno startst, sopno stopst, sopno lev);
*/
static const char * /* == stop (success) or NULL (failure) */
backref(
struct match *m,
const char *start,
const char *stop,
sopno startst,
sopno stopst,
sopno lev) /* PLUS nesting level */
{
int i;
sopno ss; /* start sop of current subRE */
const char *sp; /* start of string matched by it */
sopno ssub; /* start sop of subsubRE */
sopno esub; /* end sop of subsubRE */
const char *ssp; /* start of string matched by subsubRE */
const char *dp;
size_t len;
int hard;
sop s;
regoff_t offsave;
cset *cs;
_DIAGASSERT(m != NULL);
_DIAGASSERT(start != NULL);
_DIAGASSERT(stop != NULL);
AT("back", start, stop, startst, stopst);
sp = start;
/* get as far as we can with easy stuff */
hard = 0;
for (ss = startst; !hard && ss < stopst; ss++)
switch (OP(s = m->g->strip[ss])) {
case OCHAR:
if (sp == stop || *sp++ != (char)OPND(s))
return(NULL);
break;
case OANY:
if (sp == stop)
return(NULL);
sp++;
break;
case OANYOF:
cs = &m->g->sets[OPND(s)];
if (sp == stop || !CHIN(cs, *sp++))
return(NULL);
break;
case OBOL:
if ( (sp == m->beginp && !(m->eflags&REG_NOTBOL)) ||
(sp < m->endp && *(sp-1) == '\n' &&
(m->g->cflags&REG_NEWLINE)) )
{ /* yes */ }
else
return(NULL);
break;
case OEOL:
if ( (sp == m->endp && !(m->eflags&REG_NOTEOL)) ||
(sp < m->endp && *sp == '\n' &&
(m->g->cflags&REG_NEWLINE)) )
{ /* yes */ }
else
return(NULL);
break;
case OBOW:
if (( (sp == m->beginp && !(m->eflags&REG_NOTBOL)) ||
(sp < m->endp && *(sp-1) == '\n' &&
(m->g->cflags&REG_NEWLINE)) ||
(sp > m->beginp &&
!ISWORD(*(sp-1))) ) &&
(sp < m->endp && ISWORD(*sp)) )
{ /* yes */ }
else
return(NULL);
break;
case OEOW:
if (( (sp == m->endp && !(m->eflags&REG_NOTEOL)) ||
(sp < m->endp && *sp == '\n' &&
(m->g->cflags&REG_NEWLINE)) ||
(sp < m->endp && !ISWORD(*sp)) ) &&
(sp > m->beginp && ISWORD(*(sp-1))) )
{ /* yes */ }
else
return(NULL);
break;
case O_QUEST:
break;
case OOR1: /* matches null but needs to skip */
ss++;
s = m->g->strip[ss];
do {
assert(OP(s) == OOR2);
ss += OPND(s);
} while (OP(s = m->g->strip[ss]) != O_CH);
/* note that the ss++ gets us past the O_CH */
break;
default: /* have to make a choice */
hard = 1;
break;
}
if (!hard) { /* that was it! */
if (sp != stop)
return(NULL);
return(sp);
}
ss--; /* adjust for the for's final increment */
/* the hard stuff */
AT("hard", sp, stop, ss, stopst);
s = m->g->strip[ss];
switch (OP(s)) {
case OBACK_: /* the vilest depths */
i = OPND(s);
assert(0 < i && i <= m->g->nsub);
if (m->pmatch[i].rm_eo == (regoff_t)-1)
return(NULL);
assert(m->pmatch[i].rm_so != (regoff_t)-1);
len = (size_t)(m->pmatch[i].rm_eo - m->pmatch[i].rm_so);
if (len == 0)
return(NULL);
assert(stop - m->beginp >= len);
if (sp > stop - len)
return(NULL); /* not enough left to match */
ssp = m->offp + (size_t)m->pmatch[i].rm_so;
if (memcmp(sp, ssp, len) != 0)
return(NULL);
while (m->g->strip[ss] != SOP(O_BACK, i))
ss++;
return(backref(m, sp+len, stop, ss+1, stopst, lev));
case OQUEST_: /* to null or not */
dp = backref(m, sp, stop, ss+1, stopst, lev);
if (dp != NULL)
return(dp); /* not */
return(backref(m, sp, stop, ss+OPND(s)+1, stopst, lev));
case OPLUS_:
assert(m->lastpos != NULL);
assert(lev+1 <= m->g->nplus);
m->lastpos[lev+1] = sp;
return(backref(m, sp, stop, ss+1, stopst, lev+1));
case O_PLUS:
if (sp == m->lastpos[lev]) /* last pass matched null */
return(backref(m, sp, stop, ss+1, stopst, lev-1));
/* try another pass */
m->lastpos[lev] = sp;
dp = backref(m, sp, stop, ss-OPND(s)+1, stopst, lev);
if (dp == NULL)
dp = backref(m, sp, stop, ss+1, stopst, lev-1);
return(dp);
case OCH_: /* find the right one, if any */
ssub = ss + 1;
esub = ss + OPND(s) - 1;
assert(OP(m->g->strip[esub]) == OOR1);
for (;;) { /* find first matching branch */
dp = backref(m, sp, stop, ssub, esub, lev);
if (dp != NULL)
return(dp);
/* that one missed, try next one */
if (OP(m->g->strip[esub]) == O_CH)
return(NULL); /* there is none */
esub++;
assert(OP(m->g->strip[esub]) == OOR2);
ssub = esub + 1;
esub += OPND(m->g->strip[esub]);
if (OP(m->g->strip[esub]) == OOR2)
esub--;
else
assert(OP(m->g->strip[esub]) == O_CH);
}
case OLPAREN: /* must undo assignment if rest fails */
i = OPND(s);
assert(0 < i && i <= m->g->nsub);
offsave = m->pmatch[i].rm_so;
m->pmatch[i].rm_so = sp - m->offp;
dp = backref(m, sp, stop, ss+1, stopst, lev);
if (dp != NULL)
return(dp);
m->pmatch[i].rm_so = offsave;
return(NULL);
case ORPAREN: /* must undo assignment if rest fails */
i = OPND(s);
assert(0 < i && i <= m->g->nsub);
offsave = m->pmatch[i].rm_eo;
m->pmatch[i].rm_eo = sp - m->offp;
dp = backref(m, sp, stop, ss+1, stopst, lev);
if (dp != NULL)
return(dp);
m->pmatch[i].rm_eo = offsave;
return(NULL);
default: /* uh oh */
assert(nope);
break;
}
/* "can't happen" */
assert(nope);
/* NOTREACHED */
return NULL;
}
/*
- fast - step through the string at top speed
== static const char *fast(struct match *m, const char *start, \
== const char *stop, sopno startst, sopno stopst);
*/
static const char * /* where tentative match ended, or NULL */
fast(
struct match *m,
const char *start,
const char *stop,
sopno startst,
sopno stopst)
{
states st = m->st;
states fresh = m->fresh;
states tmp = m->tmp;
const char *p = start;
int c = (start == m->beginp) ? OUT : *(start-1);
int lastc; /* previous c */
int flagch;
int i;
const char *coldp; /* last p after which no match was underway */
_DIAGASSERT(m != NULL);
_DIAGASSERT(start != NULL);
_DIAGASSERT(stop != NULL);
CLEAR(st);
SET1(st, startst);
st = step(m->g, startst, stopst, st, NOTHING, st);
ASSIGN(fresh, st);
SP("start", st, *p);
coldp = NULL;
for (;;) {
/* next character */
lastc = c;
c = (p == m->endp) ? OUT : *p;
if (EQ(st, fresh))
coldp = p;
/* is there an EOL and/or BOL between lastc and c? */
flagch = '\0';
i = 0;
if ( (lastc == '\n' && m->g->cflags&REG_NEWLINE) ||
(lastc == OUT && !(m->eflags&REG_NOTBOL)) ) {
flagch = BOL;
i = m->g->nbol;
}
if ( (c == '\n' && m->g->cflags&REG_NEWLINE) ||
(c == OUT && !(m->eflags&REG_NOTEOL)) ) {
flagch = (flagch == BOL) ? BOLEOL : EOL;
i += m->g->neol;
}
if (i != 0) {
for (; i > 0; i--)
st = step(m->g, startst, stopst, st, flagch, st);
SP("boleol", st, c);
}
/* how about a word boundary? */
if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) &&
(c != OUT && ISWORD(c)) ) {
flagch = BOW;
}
if ( (lastc != OUT && ISWORD(lastc)) &&
(flagch == EOL || (c != OUT && !ISWORD(c))) ) {
flagch = EOW;
}
if (flagch == BOW || flagch == EOW) {
st = step(m->g, startst, stopst, st, flagch, st);
SP("boweow", st, c);
}
/* are we done? */
if (ISSET(st, stopst) || p == stop)
break; /* NOTE BREAK OUT */
/* no, we must deal with this character */
ASSIGN(tmp, st);
ASSIGN(st, fresh);
assert(c != OUT);
st = step(m->g, startst, stopst, tmp, c, st);
SP("aft", st, c);
assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st));
p++;
}
assert(coldp != NULL);
m->coldp = coldp;
if (ISSET(st, stopst))
return(p+1);
else
return(NULL);
}
/*
- slow - step through the string more deliberately
== static const char *slow(struct match *m, const char *start, \
== const char *stop, sopno startst, sopno stopst);
*/
static const char * /* where it ended */
slow(
struct match *m,
const char *start,
const char *stop,
sopno startst,
sopno stopst)
{
states st = m->st;
states empty = m->empty;
states tmp = m->tmp;
const char *p = start;
int c = (start == m->beginp) ? OUT : *(start-1);
int lastc; /* previous c */
int flagch;
int i;
const char *matchp; /* last p at which a match ended */
_DIAGASSERT(m != NULL);
_DIAGASSERT(start != NULL);
_DIAGASSERT(stop != NULL);
AT("slow", start, stop, startst, stopst);
CLEAR(st);
SET1(st, startst);
SP("sstart", st, *p);
st = step(m->g, startst, stopst, st, NOTHING, st);
matchp = NULL;
for (;;) {
/* next character */
lastc = c;
c = (p == m->endp) ? OUT : *p;
/* is there an EOL and/or BOL between lastc and c? */
flagch = '\0';
i = 0;
if ( (lastc == '\n' && m->g->cflags&REG_NEWLINE) ||
(lastc == OUT && !(m->eflags&REG_NOTBOL)) ) {
flagch = BOL;
i = m->g->nbol;
}
if ( (c == '\n' && m->g->cflags&REG_NEWLINE) ||
(c == OUT && !(m->eflags&REG_NOTEOL)) ) {
flagch = (flagch == BOL) ? BOLEOL : EOL;
i += m->g->neol;
}
if (i != 0) {
for (; i > 0; i--)
st = step(m->g, startst, stopst, st, flagch, st);
SP("sboleol", st, c);
}
/* how about a word boundary? */
if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) &&
(c != OUT && ISWORD(c)) ) {
flagch = BOW;
}
if ( (lastc != OUT && ISWORD(lastc)) &&
(flagch == EOL || (c != OUT && !ISWORD(c))) ) {
flagch = EOW;
}
if (flagch == BOW || flagch == EOW) {
st = step(m->g, startst, stopst, st, flagch, st);
SP("sboweow", st, c);
}
/* are we done? */
if (ISSET(st, stopst))
matchp = p;
if (EQ(st, empty) || p == stop)
break; /* NOTE BREAK OUT */
/* no, we must deal with this character */
ASSIGN(tmp, st);
ASSIGN(st, empty);
assert(c != OUT);
st = step(m->g, startst, stopst, tmp, c, st);
SP("saft", st, c);
assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st));
p++;
}
return(matchp);
}
/*
- step - map set of states reachable before char to set reachable after
== static states step(struct re_guts *g, sopno start, sopno stop, \
== states bef, int ch, states aft);
== #define BOL (OUT+1)
== #define EOL (BOL+1)
== #define BOLEOL (BOL+2)
== #define NOTHING (BOL+3)
== #define BOW (BOL+4)
== #define EOW (BOL+5)
== #define CODEMAX (BOL+5) // highest code used
== #define NONCHAR(c) ((c) > CHAR_MAX)
== #define NNONCHAR (CODEMAX-CHAR_MAX)
*/
static states
step(
struct re_guts *g,
sopno start, /* start state within strip */
sopno stop, /* state after stop state within strip */
states bef, /* states reachable before */
int ch, /* character or NONCHAR code */
states aft) /* states already known reachable after */
{
cset *cs;
sop s;
sopno pc;
onestate here; /* note, macros know this name */
sopno look;
int i;
_DIAGASSERT(g != NULL);
for (pc = start, INIT(here, pc); pc != stop; pc++, INC(here)) {
s = g->strip[pc];
switch (OP(s)) {
case OEND:
assert(pc == stop-1);
break;
case OCHAR:
/* only characters can match */
assert(!NONCHAR(ch) || ch != (char)OPND(s));
if (ch == (char)OPND(s))
FWD(aft, bef, 1);
break;
case OBOL:
if (ch == BOL || ch == BOLEOL)
FWD(aft, bef, 1);
break;
case OEOL:
if (ch == EOL || ch == BOLEOL)
FWD(aft, bef, 1);
break;
case OBOW:
if (ch == BOW)
FWD(aft, bef, 1);
break;
case OEOW:
if (ch == EOW)
FWD(aft, bef, 1);
break;
case OANY:
if (!NONCHAR(ch))
FWD(aft, bef, 1);
break;
case OANYOF:
cs = &g->sets[OPND(s)];
if (!NONCHAR(ch) && CHIN(cs, ch))
FWD(aft, bef, 1);
break;
case OBACK_: /* ignored here */
case O_BACK:
FWD(aft, aft, 1);
break;
case OPLUS_: /* forward, this is just an empty */
FWD(aft, aft, 1);
break;
case O_PLUS: /* both forward and back */
FWD(aft, aft, 1);
i = ISSETBACK(aft, OPND(s));
BACK(aft, aft, OPND(s));
if (!i && ISSETBACK(aft, OPND(s))) {
/* oho, must reconsider loop body */
pc -= OPND(s) + 1;
INIT(here, pc);
}
break;
case OQUEST_: /* two branches, both forward */
FWD(aft, aft, 1);
FWD(aft, aft, OPND(s));
break;
case O_QUEST: /* just an empty */
FWD(aft, aft, 1);
break;
case OLPAREN: /* not significant here */
case ORPAREN:
FWD(aft, aft, 1);
break;
case OCH_: /* mark the first two branches */
FWD(aft, aft, 1);
assert(OP(g->strip[pc+OPND(s)]) == OOR2);
FWD(aft, aft, OPND(s));
break;
case OOR1: /* done a branch, find the O_CH */
if (ISSTATEIN(aft, here)) {
for (look = 1;
OP(s = g->strip[pc+look]) != O_CH;
look += OPND(s))
assert(OP(s) == OOR2);
FWD(aft, aft, look);
}
break;
case OOR2: /* propagate OCH_'s marking */
FWD(aft, aft, 1);
if (OP(g->strip[pc+OPND(s)]) != O_CH) {
assert(OP(g->strip[pc+OPND(s)]) == OOR2);
FWD(aft, aft, OPND(s));
}
break;
case O_CH: /* just empty */
FWD(aft, aft, 1);
break;
default: /* ooooops... */
assert(nope);
break;
}
}
return(aft);
}
#ifdef REDEBUG
/*
- print - print a set of states
== #ifdef REDEBUG
== static void print(struct match *m, char *caption, states st, \
== int ch, FILE *d);
== #endif
*/
static void
print(
struct match *m,
char *caption,
states st,
int ch,
FILE *d)
{
struct re_guts *g = m->g;
int i;
int first = 1;
_DIAGASSERT(m != NULL);
_DIAGASSERT(caption != NULL);
if (!(m->eflags&REG_TRACE))
return;
_DIAGASSERT(d != NULL);
fprintf(d, "%s", caption);
if (ch != '\0')
fprintf(d, " %s", pchar(ch));
for (i = 0; i < g->nstates; i++)
if (ISSET(st, i)) {
fprintf(d, "%s%d", (first) ? "\t" : ", ", i);
first = 0;
}
fprintf(d, "\n");
}
/*
- at - print current situation
== #ifdef REDEBUG
== static void at(struct match *m, char *title, char *start, char *stop, \
== sopno startst, sopno stopst);
== #endif
*/
static void
at(
struct match *m,
char *title,
char *start,
char *stop,
sopno startst,
sopno stopst)
{
_DIAGASSERT(m != NULL);
_DIAGASSERT(title != NULL);
_DIAGASSERT(start != NULL);
_DIAGASSERT(stop != NULL);
if (!(m->eflags&REG_TRACE))
return;
printf("%s %s-", title, pchar(*start));
printf("%s ", pchar(*stop));
printf("%ld-%ld\n", (long)startst, (long)stopst);
}
#ifndef PCHARDONE
#define PCHARDONE /* never again */
/*
- pchar - make a character printable
== #ifdef REDEBUG
== static char *pchar(int ch);
== #endif
*
* Is this identical to regchar() over in debug.c? Well, yes. But a
* duplicate here avoids having a debugging-capable regexec.o tied to
* a matching debug.o, and this is convenient. It all disappears in
* the non-debug compilation anyway, so it doesn't matter much.
*/
static char * /* -> representation */
pchar(
int ch)
{
static char pbuf[10];
if (isprint(ch) || ch == ' ')
(void)snprintf(pbuf, sizeof pbuf, "%c", ch);
else
(void)snprintf(pbuf, sizeof pbuf, "\\%o", ch);
return(pbuf);
}
#endif
#endif
#undef matcher
#undef fast
#undef slow
#undef dissect
#undef backref
#undef step
#undef print
#undef at
#undef match
#undef nope
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