#include "regimpl.h"
typedef struct RethreadQ RethreadQ;
-struct RethreadQ
-{
+struct RethreadQ {
Rethread *head;
Rethread **tail;
};
int
-regexec(Reprog *prog, char *str, Resub *sem, int msize)
+regexec(Reprog *p, char *str, Resub *sem, int msize)
{
RethreadQ lists[2], *clist, *nlist, *tmp;
- Rethread *t, *nextthr, **availthr;
- Reinst *curinst;
+ Rethread *t, *next, *pool, *avail;
+ Reinst *ci;
Rune r;
char *sp, *ep, endc;
- int i, match, first, gen, matchpri, pri;
+ int i, matchgen, gen;
+ memset(p->threads, 0, sizeof(Rethread)*p->nthr);
if(msize > NSUBEXPM)
msize = NSUBEXPM;
-
- if(prog->startinst->gen != 0) {
- for(curinst = prog->startinst; curinst < prog->startinst + prog->len; curinst++)
- curinst->gen = 0;
+ if(p->startinst->gen != 0) {
+ for(ci = p->startinst; ci < p->startinst + p->len; ci++)
+ ci->gen = 0;
}
clist = lists;
nlist->head = nil;
nlist->tail = &nlist->head;
- for(i = 0; i < prog->nthr; i++)
- prog->thrpool[i] = prog->threads + i;
- availthr = prog->thrpool + prog->nthr;
+ pool = p->threads;
+ avail = nil;
+ gen = matchgen = 0;
- pri = matchpri = gen = match = 0;
sp = str;
ep = nil;
endc = '\0';
*sem->ep = '\0';
}
}
- r = Runemax + 1;
- for(; r != L'\0'; sp += i) {
- gen++;
+
+ for(r = L'☺'; r != L'\0'; sp += i) {
i = chartorune(&r, sp);
- first = 1;
+ 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)
- goto Start;
- curinst = t->pc;
+ break;
+ ci = t->i;
Again:
- if(curinst->gen == gen)
+ if(ci->gen == gen)
goto Done;
- curinst->gen = gen;
- switch(curinst->op) {
+ ci->gen = gen;
+ switch(ci->op) {
case ORUNE:
- if(r != curinst->r)
+ if(r != ci->r)
goto Done;
case OANY: /* fallthrough */
- Any:
- nextthr = t->next;
- t->pc = curinst + 1;
+ next = t->next;
+ t->i = ci + 1;
t->next = nil;
*nlist->tail = t;
nlist->tail = &t->next;
- if(nextthr == nil)
- break;
- t = nextthr;
- curinst = t->pc;
- goto Again;
+ goto Next;
case OCLASS:
Class:
- if(r < curinst->r)
+ if(r < ci->r)
goto Done;
- if(r > curinst->r1) {
- curinst++;
+ if(r > ci->r1) {
+ ci++;
goto Class;
}
- nextthr = t->next;
- t->pc = curinst->a;
+ next = t->next;
+ t->i = ci->a;
t->next = nil;
*nlist->tail = t;
nlist->tail = &t->next;
- if(nextthr == nil)
- break;
- t = nextthr;
- curinst = t->pc;
- goto Again;
+ goto Next;
case ONOTNL:
if(r != L'\n') {
- curinst++;
+ ci++;
goto Again;
}
goto Done;
case OBOL:
if(sp == str || sp[-1] == '\n') {
- curinst++;
+ ci++;
goto Again;
}
goto Done;
case OEOL:
- if(r == L'\0' && ep == nil) {
- curinst++;
+ if(r == L'\n' || r == L'\0' && ep == nil) {
+ ci++;
goto Again;
}
- if(r == L'\n')
- goto Any;
goto Done;
case OJMP:
- curinst = curinst->a;
+ ci = ci->a;
goto Again;
case OSPLIT:
- nextthr = *--availthr;
- nextthr->pc = curinst->b;
+ 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(nextthr->sem, t->sem, sizeof(Resub)*msize);
- nextthr->pri = t->pri;
- nextthr->next = t->next;
- t->next = nextthr;
- curinst = curinst->a;
+ 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(curinst->sub < msize)
- t->sem[curinst->sub].sp = sp;
- curinst++;
+ if(ci->sub < msize)
+ t->sem[ci->sub].sp = sp;
+ ci++;
goto Again;
case OUNSAVE:
- if(curinst->sub == 0) {
- /* "Highest" priority is the left-most longest. */
- if (t->pri > matchpri)
- goto Done;
- match = 1;
- matchpri = t->pri;
+ if(ci->sub == 0) {
+ matchgen = t->gen;
if(sem != nil && msize > 0) {
memcpy(sem, t->sem, sizeof(Resub)*msize);
sem->ep = sp;
}
goto Done;
}
- if(curinst->sub < msize)
- t->sem[curinst->sub].ep = sp;
- curinst++;
+ if(ci->sub < msize)
+ t->sem[ci->sub].ep = sp;
+ ci++;
goto Again;
Done:
- *availthr++ = t;
- t = t->next;
- if(t == nil)
+ next = t->next;
+ t->next = avail;
+ avail = t;
+ Next:
+ if(next == nil)
break;
- curinst = t->pc;
- goto Again;
- }
-Start:
- /* Start again once if we haven't found anything. */
- if(first == 1 && match == 0) {
- first = 0;
- t = *--availthr;
- if(msize > 0)
- memset(t->sem, 0, sizeof(Resub)*msize);
- /* "Lower" priority thread */
- t->pri = matchpri = pri++;
- t->next = nil;
- curinst = prog->startinst;
+ if(matchgen && next->gen > matchgen) {
+ *clist->tail = avail;
+ avail = next;
+ break;
+ }
+ t = next;
+ ci = t->i;
goto Again;
}
- /* If we have a match and no extant threads, we are done. */
- if(match == 1 && nlist->head == nil)
- break;
tmp = clist;
clist = nlist;
nlist = tmp;
}
if(ep != nil)
*ep = endc;
- return match;
+ return matchgen > 0 ? 1 : 0;
}