tacme: regexp fix (see libregexp change) - plan9port - [fork] Plan 9 from user space
(HTM) git clone git://src.adamsgaard.dk/plan9port
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---
(DIR) commit 6f16e7fc1b35c2e99c9dc069e6ec81a9ac07ca21
(DIR) parent a7511dd43d9afe8025a6d7bd2fcccf8f594a6f2b
(HTM) Author: Russ Cox <rsc@swtch.com>
Date: Fri, 7 Dec 2007 15:33:38 -0500
acme: regexp fix (see libregexp change)
Diffstat:
M src/cmd/acme/regx.c | 110 +++++++++++++++++--------------
1 file changed, 59 insertions(+), 51 deletions(-)
---
(DIR) diff --git a/src/cmd/acme/regx.c b/src/cmd/acme/regx.c
t@@ -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
t@@ -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;
t@@ -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;
t@@ -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){
t@@ -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);
t@@ -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;
t@@ -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;
t@@ -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);
t@@ -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;
t@@ -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){
t@@ -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;
t@@ -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;
t@@ -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;