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-rw-r--r--pcre/pcre_study.c60
1 files changed, 48 insertions, 12 deletions
diff --git a/pcre/pcre_study.c b/pcre/pcre_study.c
index f19d9fbb902..998fe2325ef 100644
--- a/pcre/pcre_study.c
+++ b/pcre/pcre_study.c
@@ -70,7 +70,7 @@ Arguments:
code pointer to start of group (the bracket)
startcode pointer to start of the whole pattern's code
options the compiling options
- int RECURSE depth
+ recurses chain of recurse_check to catch mutual recursion
Returns: the minimum length
-1 if \C in UTF-8 mode or (*ACCEPT) was encountered
@@ -80,12 +80,13 @@ Returns: the minimum length
static int
find_minlength(const REAL_PCRE *re, const pcre_uchar *code,
- const pcre_uchar *startcode, int options, int recurse_depth)
+ const pcre_uchar *startcode, int options, recurse_check *recurses)
{
int length = -1;
/* PCRE_UTF16 has the same value as PCRE_UTF8. */
BOOL utf = (options & PCRE_UTF8) != 0;
BOOL had_recurse = FALSE;
+recurse_check this_recurse;
register int branchlength = 0;
register pcre_uchar *cc = (pcre_uchar *)code + 1 + LINK_SIZE;
@@ -130,7 +131,7 @@ for (;;)
case OP_SBRAPOS:
case OP_ONCE:
case OP_ONCE_NC:
- d = find_minlength(re, cc, startcode, options, recurse_depth);
+ d = find_minlength(re, cc, startcode, options, recurses);
if (d < 0) return d;
branchlength += d;
do cc += GET(cc, 1); while (*cc == OP_ALT);
@@ -393,7 +394,7 @@ for (;;)
ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(slot, 0));
if (cs == NULL) return -2;
do ce += GET(ce, 1); while (*ce == OP_ALT);
- if (cc > cs && cc < ce)
+ if (cc > cs && cc < ce) /* Simple recursion */
{
d = 0;
had_recurse = TRUE;
@@ -401,8 +402,22 @@ for (;;)
}
else
{
- int dd = find_minlength(re, cs, startcode, options, recurse_depth);
- if (dd < d) d = dd;
+ recurse_check *r = recurses;
+ for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
+ if (r != NULL) /* Mutual recursion */
+ {
+ d = 0;
+ had_recurse = TRUE;
+ break;
+ }
+ else
+ {
+ int dd;
+ this_recurse.prev = recurses;
+ this_recurse.group = cs;
+ dd = find_minlength(re, cs, startcode, options, &this_recurse);
+ if (dd < d) d = dd;
+ }
}
slot += re->name_entry_size;
}
@@ -418,14 +433,26 @@ for (;;)
ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(cc, 1));
if (cs == NULL) return -2;
do ce += GET(ce, 1); while (*ce == OP_ALT);
- if (cc > cs && cc < ce)
+ if (cc > cs && cc < ce) /* Simple recursion */
{
d = 0;
had_recurse = TRUE;
}
else
{
- d = find_minlength(re, cs, startcode, options, recurse_depth);
+ recurse_check *r = recurses;
+ for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
+ if (r != NULL) /* Mutual recursion */
+ {
+ d = 0;
+ had_recurse = TRUE;
+ }
+ else
+ {
+ this_recurse.prev = recurses;
+ this_recurse.group = cs;
+ d = find_minlength(re, cs, startcode, options, &this_recurse);
+ }
}
}
else d = 0;
@@ -474,12 +501,21 @@ for (;;)
case OP_RECURSE:
cs = ce = (pcre_uchar *)startcode + GET(cc, 1);
do ce += GET(ce, 1); while (*ce == OP_ALT);
- if ((cc > cs && cc < ce) || recurse_depth > 10)
+ if (cc > cs && cc < ce) /* Simple recursion */
had_recurse = TRUE;
else
{
- branchlength += find_minlength(re, cs, startcode, options,
- recurse_depth + 1);
+ recurse_check *r = recurses;
+ for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
+ if (r != NULL) /* Mutual recursion */
+ had_recurse = TRUE;
+ else
+ {
+ this_recurse.prev = recurses;
+ this_recurse.group = cs;
+ branchlength += find_minlength(re, cs, startcode, options,
+ &this_recurse);
+ }
}
cc += 1 + LINK_SIZE;
break;
@@ -1503,7 +1539,7 @@ if ((re->options & PCRE_ANCHORED) == 0 &&
/* Find the minimum length of subject string. */
-switch(min = find_minlength(re, code, code, re->options, 0))
+switch(min = find_minlength(re, code, code, re->options, NULL))
{
case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
case -3: *errorptr = "internal error: opcode not recognized"; return NULL;