cirno/plan9port
1
0
Fork 0
mirror of https://github.com/9fans/plan9port.git synced 2025-01-27 11:52:03 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

acme: regexp fix (see libregexp change)

Browse source
This commit is contained in:
Russ Cox 2007-12-07 15:33:38 -05:00
parent a7511dd43d
commit 6f16e7fc1b
1 changed files with 59 additions and 51 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

110
src/cmd/acme/regx.c
View file

@ -521,26 +521,56 @@ classmatch(int classno, int c, int negate)
}
/*
* Note optimization in addinst:
* *l must be pending when addinst called; if *l has been looked
* at already, the optimization is a bug.
* Add inst to the list [l, l+NLIST), but only if it is not there already.
* These work lists are stored and processed in increasing
* order of sep->p[0], so if the inst is there already, the one
* there already is a more left match and takes priority.
* (This works for backward searches too, because there
* is no explicit comparison.)
*/
int
addinst(Ilist *l, Inst *inst, Rangeset *sep)
Ilist*
addinst1(Ilist *l, Inst *inst, Rangeset *sep)
{
Ilist *p;
for(p = l; p->inst; p++){
if(p->inst==inst){
if((sep)->r[0].q0 < p->se.r[0].q0)
p->se= *sep; /* this would be bug */
return 0; /* It's already there */
for(p = l; p->inst; p++)
if(p->inst==inst)
return 0;
if(p == l+NLIST)
return l+NLIST;
p->inst = inst;
p->se = *sep;
(p+1)->inst = 0;
return p;
}
int
addinst(Ilist *l, Inst *inst, Rangeset *sep)
{
Ilist *ap;
ap = addinst1(l, inst, sep);
if(ap == 0)
return 0;
if(ap == l+NLIST)
return -1;
/*
* Added inst to list at ap.
* Expand any ORs right now, so that entire
* work list ends up being sorted by increasing sep->p[0].
*/
for(; ap->inst; ap++){
if(ap->inst->type == OR){
if(addinst1(l, ap->inst->u1.left, &ap->se) == l+NLIST)
return -1;
if(addinst1(l, ap->inst->u.right, &ap->se) == l+NLIST)
return -1;
}
}
p->inst = inst;
p->se= *sep;
(p+1)->inst = nil;
return 1;
return 0;
}
int
@ -557,7 +587,6 @@ rxexecute(Text *t, Rune *r, uint startp, uint eof, Rangeset *rp)
Inst *inst;
Ilist *tlp;
uint p;
int nnl, ntl;
int nc, c;
int wrapped;
int startchar;
@ -566,7 +595,6 @@ rxexecute(Text *t, Rune *r, uint startp, uint eof, Rangeset *rp)
p = startp;
startchar = 0;
wrapped = 0;
nnl = 0;
if(startinst->type<OPERATOR)
startchar = startinst->type;
list[0][0].inst = list[1][0].inst = nil;
@ -576,6 +604,7 @@ rxexecute(Text *t, Rune *r, uint startp, uint eof, Rangeset *rp)
else
nc = runestrlen(r);
/* Execute machine once for each character */
nl = list[0];
for(;;p++){
doloop:
if(p>=eof || p>=nc){
@ -594,7 +623,7 @@ rxexecute(Text *t, Rune *r, uint startp, uint eof, Rangeset *rp)
}
c = 0;
}else{
if(((wrapped && p>=startp) || sel.r[0].q0>0) && nnl==0)
if(((wrapped && p>=startp) || sel.r[0].q0>0) && nl->inst==0)
break;
if(t != nil)
c = textreadc(t, p);
@ -602,18 +631,15 @@ rxexecute(Text *t, Rune *r, uint startp, uint eof, Rangeset *rp)
c = r[p];
}
/* fast check for first char */
if(startchar && nnl==0 && c!=startchar)
if(startchar && nl->inst==0 && c!=startchar)
continue;
tl = list[flag];
nl = list[flag^=1];
nl->inst = nil;
ntl = nnl;
nnl = 0;
if(sel.r[0].q0<0 && (!wrapped || p<startp || startp==eof)){
/* Add first instruction to this list */
sempty.r[0].q0 = p;
if(addinst(tl, startinst, &sempty))
if(++ntl >= NLIST){
if(addinst(tl, startinst, &sempty) < 0){
Overflow:
warning(nil, "regexp list overflow\n");
sel.r[0].q0 = -1;
@ -627,8 +653,7 @@ rxexecute(Text *t, Rune *r, uint startp, uint eof, Rangeset *rp)
default: /* regular character */
if(inst->type==c){
Addinst:
if(addinst(nl, inst->u1.next, &tlp->se))
if(++nnl >= NLIST)
if(addinst(nl, inst->u1.next, &tlp->se) < 0)
goto Overflow;
}
break;
@ -666,13 +691,8 @@ rxexecute(Text *t, Rune *r, uint startp, uint eof, Rangeset *rp)
goto Addinst;
break;
case OR:
/* evaluate right choice later */
if(addinst(tl, inst->u.right, &tlp->se))
if(++ntl >= NLIST)
goto Overflow;
/* efficiency: advance and re-evaluate */
inst = inst->u1.left;
goto Switchstmt;
/* already expanded; just a placeholder */
break;
case END: /* Match! */
tlp->se.r[0].q1 = p;
newmatch(&tlp->se);
@ -700,13 +720,11 @@ rxbexecute(Text *t, uint startp, Rangeset *rp)
Inst *inst;
Ilist *tlp;
int p;
int nnl, ntl;
int c;
int wrapped;
int startchar;
flag = 0;
nnl = 0;
wrapped = 0;
p = startp;
startchar = 0;
@ -715,6 +733,7 @@ rxbexecute(Text *t, uint startp, Rangeset *rp)
list[0][0].inst = list[1][0].inst = nil;
sel.r[0].q0= -1;
/* Execute machine once for each character, including terminal NUL */
nl = list[0];
for(;;--p){
doloop:
if(p <= 0){
@ -734,24 +753,20 @@ rxbexecute(Text *t, uint startp, Rangeset *rp)
}
c = 0;
}else{
if(((wrapped && p<=startp) || sel.r[0].q0>0) && nnl==0)
if(((wrapped && p<=startp) || sel.r[0].q0>0) && nl->inst==0)
break;
c = textreadc(t, p-1);
}
/* fast check for first char */
if(startchar && nnl==0 && c!=startchar)
if(startchar && nl->inst==0 && c!=startchar)
continue;
tl = list[flag];
nl = list[flag^=1];
nl->inst = nil;
ntl = nnl;
nnl = 0;
if(sel.r[0].q0<0 && (!wrapped || p>startp)){
/* Add first instruction to this list */
/* the minus is so the optimizations in addinst work */
sempty.r[0].q0 = -p;
if(addinst(tl, bstartinst, &sempty))
if(++ntl >= NLIST){
sempty.r[0].q0 = p;
if(addinst(tl, bstartinst, &sempty) < 0){
Overflow:
warning(nil, "regexp list overflow\n");
sel.r[0].q0 = -1;
@ -765,8 +780,7 @@ rxbexecute(Text *t, uint startp, Rangeset *rp)
default: /* regular character */
if(inst->type == c){
Addinst:
if(addinst(nl, inst->u1.next, &tlp->se))
if(++nnl >= NLIST)
if(addinst(nl, inst->u1.next, &tlp->se) < 0)
goto Overflow;
}
break;
@ -804,15 +818,9 @@ rxbexecute(Text *t, uint startp, Rangeset *rp)
goto Addinst;
break;
case OR:
/* evaluate right choice later */
if(addinst(tl, inst->u.right, &tlp->se))
if(++ntl >= NLIST)
goto Overflow;
/* efficiency: advance and re-evaluate */
inst = inst->u1.left;
goto Switchstmt;
/* already expanded; just a placeholder */
break;
case END: /* Match! */
tlp->se.r[0].q0 = -tlp->se.r[0].q0; /* minus sign */
tlp->se.r[0].q1 = p;
bnewmatch(&tlp->se);
break;