pedroediaz/lexvm
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posibly a saner implementation (plist)

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This commit is contained in:
Kyryl Melekhin
2021-10-15 20:32:09 +00:00
parent 55a582230c
commit 3c384b905e
2 changed files with 14 additions and 14 deletions
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2
README
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@@ -124,7 +124,7 @@ chance of overflowing the int and getting a run on a false state
left from previous use of the regex. Though if overflow never
happens there is no chance of getting a false state. Overflows
like this pose a high security threat, if the hacker knows
how many cycles he needs to overflow the gen varible and get
how many cycles he needs to overflow the gen variable and get
inconsistent result. It is possible to reset the marks if we
near the overflow, but as you may guess that does not come
for free.

26
pike.c
View File

@@ -458,17 +458,17 @@ if (--csub->ref == 0) { \
#define deccheck(nn) \
{ decref(nsub) goto rec_check##nn; } \
#define onnlist(nn, list, listidx, when, pre) \
when for (j = 0; j < listidx; j++) \
if (npc == list[j].pc) \
{ pre deccheck(nn) } \
#define onnlist(nn) \
for (j = 0; j < plistidx; j++) \
if (npc == plist[j]) \
deccheck(nn) \
plist[plistidx++] = npc; \
#define onclist(nn, list, listidx, i, pre) \
#define onclist(nn) \
#define fastrec(nn, list, listidx) \
nsub->ref++; \
if (*npc < WBEG) { \
on##list(nn, list, listidx, /*nop*/, subs[i++] = nsub;) \
list[listidx].sub = nsub; \
list[listidx++].pc = npc; \
npc = pcs[i]; \
@@ -490,7 +490,6 @@ memcpy(s1->sub, nsub->sub, osubp); \
int i = 0; \
rec##nn: \
if (*npc < WBEG) { \
on##list(nn, list, listidx, if (i), /*nop*/) \
list[listidx].sub = nsub; \
list[listidx++].pc = npc; \
rec_check##nn: \
@@ -507,10 +506,12 @@ memcpy(s1->sub, nsub->sub, osubp); \
npc += 2 + npc[1]; \
goto rec##nn; \
case SPLIT: \
on##list(nn) \
npc += 2; \
pcs[i] = npc + npc[-1]; \
fastrec(nn, list, listidx) \
case RSPLIT: \
on##list(nn) \
npc += 2; \
pcs[i] = npc; \
npc += npc[-1]; \
@@ -551,11 +552,11 @@ memcpy(s1->sub, nsub->sub, osubp); \
int re_pikevm(rcode *prog, const char *s, const char **subp, int nsubp)
{
int rsubsize = sizeof(rsub)+(sizeof(char*)*nsubp);
int i, j, c, suboff = rsubsize, *npc;
int clistidx = 0, nlistidx = 0, osubp = nsubp * sizeof(char*);
int i, j, c, suboff = rsubsize, *npc, osubp = nsubp * sizeof(char*);
int clistidx = 0, nlistidx = 0, plistidx = 0;
const char *sp = s, *_sp = s;
int *insts = prog->insts;
int *pcs[prog->splits];
int *pcs[prog->splits], *plist[prog->splits];
rsub *subs[prog->splits];
char nsubs[500000];
rsub *nsub, *s1, *matched = NULL, *freesub = NULL;
@@ -597,14 +598,13 @@ int re_pikevm(rcode *prog, const char *s, const char **subp, int nsubp)
clist = nlist;
nlist = tmp;
clistidx = nlistidx;
nlistidx = 0;
nlistidx = 0; plistidx = 0;
if (!matched) {
jmp_start:
newsub(memset(s1->sub, 0, osubp);, /*nop*/)
s1->ref = 1;
s1->sub[0] = _sp;
nsub = s1;
npc = insts;
nsub = s1; npc = insts;
addthread(1, clist, clistidx)
} else if (!clistidx)
break;