diff options
Diffstat (limited to 'pcre/pcre_study.c')
| -rw-r--r-- | pcre/pcre_study.c | 60 |
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; |