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#include <u.h>
#include <libc.h>
#include <regexp.h>
#include "regimpl.h"
typedef struct RethreadQ RethreadQ;
struct RethreadQ {
Rethread *head;
Rethread **tail;
};
int
rregexec(Reprog *p, Rune *str, Resub *sem, int msize)
{
RethreadQ lists[2], *clist, *nlist, *tmp;
Rethread *t, *next, *pool, *avail;
Reinst *ci;
Rune *rsp, *rep, endr, r;
int matchgen, gen;
memset(p->threads, 0, sizeof(Rethread)*p->nthr);
if(msize > NSUBEXPM)
msize = NSUBEXPM;
if(p->startinst->gen != 0) {
for(ci = p->startinst; ci < p->startinst + p->len; ci++)
ci->gen = 0;
}
clist = lists;
clist->head = nil;
clist->tail = &clist->head;
nlist = lists + 1;
nlist->head = nil;
nlist->tail = &nlist->head;
pool = p->threads;
avail = nil;
gen = matchgen = 0;
rsp = str;
rep = nil;
endr = L'\0';
if(sem != nil && msize > 0) {
if(sem->rsp != nil)
rsp = sem->rsp;
if(sem->rep != nil && *sem->rep != L'\0') {
rep = sem->rep;
endr = *sem->rep;
*sem->rep = '\0';
}
}
for(r = L'☺'; r != L'\0'; rsp++) {
r = *rsp;
gen++;
if(matchgen == 0) {
if(avail == nil) {
assert(pool < p->threads + p->nthr);
t = pool++;
} else {
t = avail;
avail = avail->next;
}
t->i = p->startinst;
if(msize > 0)
memset(t->sem, 0, sizeof(Resub)*msize);
t->next = nil;
t->gen = gen;
*clist->tail = t;
clist->tail = &t->next;
}
t = clist->head;
if(t == nil)
break;
ci = t->i;
Again:
if(ci->gen == gen)
goto Done;
ci->gen = gen;
switch(ci->op) {
case ORUNE:
if(r != ci->r)
goto Done;
case OANY: /* fallthrough */
next = t->next;
t->i = ci + 1;
t->next = nil;
*nlist->tail = t;
nlist->tail = &t->next;
goto Next;
case OCLASS:
Class:
if(r < ci->r)
goto Done;
if(r > ci->r1) {
ci++;
goto Class;
}
next = t->next;
t->i = ci->a;
t->next = nil;
*nlist->tail = t;
nlist->tail = &t->next;
goto Next;
case ONOTNL:
if(r != L'\n') {
ci++;
goto Again;
}
goto Done;
case OBOL:
if(rsp == str || rsp[-1] == L'\n') {
ci++;
goto Again;
}
goto Done;
case OEOL:
if(r == L'\n' || r == L'\0' && rep == nil) {
ci++;
goto Again;
}
goto Done;
case OJMP:
ci = ci->a;
goto Again;
case OSPLIT:
if(avail == nil) {
assert(pool < p->threads + p->nthr);
next = pool++;
} else {
next = avail;
avail = avail->next;
}
next->i = ci->b;
if(msize > 0)
memcpy(next->sem, t->sem, sizeof(Resub)*msize);
next->next = t->next;
next->gen = t->gen;
t->next = next;
ci = ci->a;
goto Again;
case OSAVE:
if(ci->sub < msize)
t->sem[ci->sub].rsp = rsp;
ci++;
goto Again;
case OUNSAVE:
if(ci->sub == 0) {
matchgen = t->gen;
if(sem != nil && msize > 0) {
memcpy(sem, t->sem, sizeof(Resub)*msize);
sem->rep = rsp;
}
goto Done;
}
if(ci->sub < msize)
t->sem[ci->sub].rep = rsp;
ci++;
goto Again;
Done:
next = t->next;
t->next = avail;
avail = t;
Next:
if(next == nil)
break;
if(matchgen && next->gen > matchgen) {
*clist->tail = avail;
avail = next;
break;
}
t = next;
ci = t->i;
goto Again;
}
tmp = clist;
clist = nlist;
nlist = tmp;
nlist->head = nil;
nlist->tail = &nlist->head;
}
if(rep != nil)
*rep = endr;
return matchgen > 0 ? 1 : 0;
}
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