/*
- complicatedFind - find a match for the main NFA (with complications)
^ static int complicatedFind(struct vars *, struct cnfa *, struct colormap *);
*/
static int
complicatedFind(
struct vars *const v,
struct cnfa *const cnfa,
struct colormap *const cm)
{
struct dfa *s, *d;
chr *cold = NULL; /* silence gcc 4 warning */
int ret;
s = newDFA(v, &v->g->search, cm, &v->dfa1);
NOERR();
d = newDFA(v, cnfa, cm, &v->dfa2);
if (ISERR()) {
assert(d == NULL);
freeDFA(s);
return v->err;
}
ret = complicatedFindLoop(v, cnfa, cm, d, s, &cold);
freeDFA(d);
freeDFA(s);
NOERR();
if (v->g->cflags®_EXPECT) {
assert(v->details != NULL);
if (cold != NULL) {
v->details->rm_extend.rm_so = OFF(cold);
} else {
v->details->rm_extend.rm_so = OFF(v->stop);
}
v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */
}
return ret;
}
/*
- alternationDissect - determine alternative subexpression matches (uncomplicated)
^ static int alternationDissect(struct vars *, struct subre *, chr *, chr *);
*/
static int /* regexec return code */
alternationDissect(
struct vars *const v,
struct subre *t,
chr *const begin, /* beginning of relevant substring */
chr *const end) /* end of same */
{
int i;
assert(t != NULL);
assert(t->op == '|');
for (i = 0; t != NULL; t = t->right, i++) {
struct dfa *d;
MDEBUG(("trying %dth\n", i));
assert(t->left != NULL && t->left->cnfa.nstates > 0);
d = newDFA(v, &t->left->cnfa, &v->g->cmap, &v->dfa1);
if (ISERR()) {
return v->err;
}
if (longest(v, d, begin, end, NULL) == end) {
MDEBUG(("success\n"));
freeDFA(d);
return dissect(v, t->left, begin, end);
}
freeDFA(d);
}
return REG_ASSERT; /* none of them matched?!? */
}
/*
- complicatedAlternationDissect - determine alternative subexpression matches (w.
- complications)
^ static int complicatedAlternationDissect(struct vars *, struct subre *, chr *, chr *);
*/
static int /* regexec return code */
complicatedAlternationDissect(
struct vars *const v,
struct subre *t,
chr *const begin, /* beginning of relevant substring */
chr *const end) /* end of same */
{
int er;
#define UNTRIED 0 /* not yet tried at all */
#define TRYING 1 /* top matched, trying submatches */
#define TRIED 2 /* top didn't match or submatches exhausted */
#ifndef COMPILER_DOES_TAILCALL_OPTIMIZATION
if (0) {
doRight:
t = t->right;
}
#endif
if (t == NULL) {
return REG_NOMATCH;
}
assert(t->op == '|');
if (v->mem[t->retry] == TRIED) {
goto doRight;
}
MDEBUG(("cAlt n%d\n", t->retry));
assert(t->left != NULL);
if (v->mem[t->retry] == UNTRIED) {
struct dfa *d = newDFA(v, &t->left->cnfa, &v->g->cmap, DOMALLOC);
if (ISERR()) {
return v->err;
}
if (longest(v, d, begin, end, NULL) != end) {
freeDFA(d);
v->mem[t->retry] = TRIED;
goto doRight;
}
freeDFA(d);
MDEBUG(("cAlt matched\n"));
v->mem[t->retry] = TRYING;
}
er = complicatedDissect(v, t->left, begin, end);
if (er != REG_NOMATCH) {
return er;
}
v->mem[t->retry] = TRIED;
#ifndef COMPILER_DOES_TAILCALL_OPTIMIZATION
goto doRight;
#else
doRight:
return complicatedAlternationDissect(v, t->right, begin, end);
#endif
}
/*
- getsubdfa - create or re-fetch the DFA for a subre node
* We only need to create the DFA once per overall regex execution.
* The DFA will be freed by the cleanup step in exec().
*/
static struct dfa *
getsubdfa(struct vars * v,
struct subre * t)
{
if (v->subdfas[t->id] == NULL) {
v->subdfas[t->id] = newDFA(v, &t->cnfa, &v->g->cmap, DOMALLOC);
if (ISERR())
return NULL;
}
return v->subdfas[t->id];
}
/*
- simpleFind - find a match for the main NFA (no-complications case)
^ static int simpleFind(struct vars *, struct cnfa *, struct colormap *);
*/
static int
simpleFind(
struct vars *const v,
struct cnfa *const cnfa,
struct colormap *const cm)
{
struct dfa *s, *d;
chr *begin, *end = NULL;
chr *cold;
chr *open, *close; /* Open and close of range of possible
* starts */
int hitend;
int shorter = (v->g->tree->flags&SHORTER) ? 1 : 0;
/*
* First, a shot with the search RE.
*/
s = newDFA(v, &v->g->search, cm, &v->dfa1);
assert(!(ISERR() && s != NULL));
NOERR();
MDEBUG(("\nsearch at %ld\n", LOFF(v->start)));
cold = NULL;
close = shortest(v, s, v->start, v->start, v->stop, &cold, NULL);
freeDFA(s);
NOERR();
if (v->g->cflags®_EXPECT) {
assert(v->details != NULL);
if (cold != NULL) {
v->details->rm_extend.rm_so = OFF(cold);
} else {
v->details->rm_extend.rm_so = OFF(v->stop);
}
v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */
}
if (close == NULL) { /* not found */
return REG_NOMATCH;
}
if (v->nmatch == 0) { /* found, don't need exact location */
return REG_OKAY;
}
/*
* Find starting point and match.
*/
assert(cold != NULL);
open = cold;
cold = NULL;
MDEBUG(("between %ld and %ld\n", LOFF(open), LOFF(close)));
d = newDFA(v, cnfa, cm, &v->dfa1);
assert(!(ISERR() && d != NULL));
NOERR();
for (begin = open; begin <= close; begin++) {
MDEBUG(("\nfind trying at %ld\n", LOFF(begin)));
if (shorter) {
end = shortest(v, d, begin, begin, v->stop, NULL, &hitend);
} else {
end = longest(v, d, begin, v->stop, &hitend);
}
if (ISERR()) {
freeDFA(d);
return v->err;
}
if (hitend && cold == NULL) {
cold = begin;
}
if (end != NULL) {
break; /* NOTE BREAK OUT */
}
}
assert(end != NULL); /* search RE succeeded so loop should */
freeDFA(d);
/*
* And pin down details.
*/
assert(v->nmatch > 0);
v->pmatch[0].rm_so = OFF(begin);
v->pmatch[0].rm_eo = OFF(end);
if (v->g->cflags®_EXPECT) {
if (cold != NULL) {
v->details->rm_extend.rm_so = OFF(cold);
} else {
v->details->rm_extend.rm_so = OFF(v->stop);
}
v->details->rm_extend.rm_eo = OFF(v->stop); /* unknown */
}
if (v->nmatch == 1) { /* no need for submatches */
return REG_OKAY;
}
/*
* Find submatches.
*/
zapallsubs(v->pmatch, v->nmatch);
return cdissect(v, v->g->tree, begin, end);
}
/*
- complicatedReversedDissect - determine backref shortest-first subexpression
- matches
* The retry memory stores the offset of the trial midpoint from begin, plus 1
* so that 0 uniquely means "clean slate".
^ static int complicatedReversedDissect(struct vars *, struct subre *, chr *, chr *);
*/
static int /* regexec return code */
complicatedReversedDissect(
struct vars *const v,
struct subre *const t,
chr *const begin, /* beginning of relevant substring */
chr *const end) /* end of same */
{
struct dfa *d, *d2;
chr *mid;
assert(t->op == '.');
assert(t->left != NULL && t->left->cnfa.nstates > 0);
assert(t->right != NULL && t->right->cnfa.nstates > 0);
assert(t->left->flags&SHORTER);
/*
* Concatenation -- need to split the substring between parts.
*/
d = newDFA(v, &t->left->cnfa, &v->g->cmap, DOMALLOC);
if (ISERR()) {
return v->err;
}
d2 = newDFA(v, &t->right->cnfa, &v->g->cmap, DOMALLOC);
if (ISERR()) {
freeDFA(d);
return v->err;
}
MDEBUG(("cRev %d\n", t->retry));
/*
* Pick a tentative midpoint.
*/
if (v->mem[t->retry] == 0) {
mid = shortest(v, d, begin, begin, end, NULL, NULL);
if (mid == NULL) {
freeDFA(d);
freeDFA(d2);
return REG_NOMATCH;
}
MDEBUG(("tentative midpoint %ld\n", LOFF(mid)));
v->mem[t->retry] = (mid - begin) + 1;
} else {
mid = begin + (v->mem[t->retry] - 1);
MDEBUG(("working midpoint %ld\n", LOFF(mid)));
}
/*
* Iterate until satisfaction or failure.
*/
for (;;) {
/*
* Try this midpoint on for size.
*/
if (longest(v, d2, mid, end, NULL) == end) {
int er = complicatedDissect(v, t->left, begin, mid);
if (er == REG_OKAY) {
er = complicatedDissect(v, t->right, mid, end);
if (er == REG_OKAY) {
/*
* Satisfaction.
*/
MDEBUG(("successful\n"));
freeDFA(d);
freeDFA(d2);
return REG_OKAY;
}
}
if (er != REG_OKAY && er != REG_NOMATCH) {
freeDFA(d);
freeDFA(d2);
return er;
}
}
/*
* That midpoint didn't work, find a new one.
*/
if (mid == end) {
/*
* All possibilities exhausted.
*/
MDEBUG(("%d no midpoint\n", t->retry));
freeDFA(d);
freeDFA(d2);
return REG_NOMATCH;
}
mid = shortest(v, d, begin, mid+1, end, NULL, NULL);
if (mid == NULL) {
/*
* Failed to find a new one.
*/
MDEBUG(("%d failed midpoint\n", t->retry));
freeDFA(d);
freeDFA(d2);
return REG_NOMATCH;
}
MDEBUG(("%d: new midpoint %ld\n", t->retry, LOFF(mid)));
v->mem[t->retry] = (mid - begin) + 1;
zapSubtree(v, t->left);
zapSubtree(v, t->right);
}
}
/*
- concatenationDissect - determine concatenation subexpression matches
- (uncomplicated)
^ static int concatenationDissect(struct vars *, struct subre *, chr *, chr *);
*/
static int /* regexec return code */
concatenationDissect(
struct vars *const v,
struct subre *const t,
chr *const begin, /* beginning of relevant substring */
chr *const end) /* end of same */
{
struct dfa *d, *d2;
chr *mid;
int i;
int shorter = (t->left->flags&SHORTER) ? 1 : 0;
chr *stop = (shorter) ? end : begin;
assert(t->op == '.');
assert(t->left != NULL && t->left->cnfa.nstates > 0);
assert(t->right != NULL && t->right->cnfa.nstates > 0);
d = newDFA(v, &t->left->cnfa, &v->g->cmap, &v->dfa1);
NOERR();
d2 = newDFA(v, &t->right->cnfa, &v->g->cmap, &v->dfa2);
if (ISERR()) {
assert(d2 == NULL);
freeDFA(d);
return v->err;
}
/*
* Pick a tentative midpoint.
*/
if (shorter) {
mid = shortest(v, d, begin, begin, end, NULL, NULL);
} else {
mid = longest(v, d, begin, end, NULL);
}
if (mid == NULL) {
freeDFA(d);
freeDFA(d2);
return REG_ASSERT;
}
MDEBUG(("tentative midpoint %ld\n", LOFF(mid)));
/*
* Iterate until satisfaction or failure.
*/
while (longest(v, d2, mid, end, NULL) != end) {
/*
* That midpoint didn't work, find a new one.
*/
if (mid == stop) {
/*
* All possibilities exhausted!
*/
MDEBUG(("no midpoint!\n"));
freeDFA(d);
freeDFA(d2);
return REG_ASSERT;
}
if (shorter) {
mid = shortest(v, d, begin, mid+1, end, NULL, NULL);
} else {
mid = longest(v, d, begin, mid-1, NULL);
}
if (mid == NULL) {
/*
* Failed to find a new one!
*/
MDEBUG(("failed midpoint!\n"));
freeDFA(d);
freeDFA(d2);
return REG_ASSERT;
}
MDEBUG(("new midpoint %ld\n", LOFF(mid)));
}
/*
* Satisfaction.
*/
MDEBUG(("successful\n"));
freeDFA(d);
freeDFA(d2);
i = dissect(v, t->left, begin, mid);
if (i != REG_OKAY) {
return i;
}
return dissect(v, t->right, mid, end);
}
