/* This function runs a regular expression match, and sets up the pointers to
the matched substrings. The matched strings are copied so the lifetime of
-the subject is not a problem.
+the subject is not a problem. Matched strings will have the same taint status
+as the subject string (this is not a de-taint method, and must not be made so
+given the support for wildcards in REs).
Arguments:
re the compiled expression
expand_nmax = setup < 0 ? 0 : setup + 1;
for (int matchnum = setup < 0 ? 0 : 1; matchnum < res; matchnum++)
{
+ /* Although PCRE2 has a pcre2_substring_get_bynumber() conveneience, it
+ seems to return a bad pointer when a capture group had no data, eg. (.*)
+ matching zero letters. So use the underlying ovec and hope (!) that the
+ offsets are sane (including that case). Should we go further and range-
+ check each one vs. the subject string length? */
int off = matchnum * 2;
int len = ovec[off + 1] - ovec[off];
expand_nstring[expand_nmax] = string_copyn(subject + ovec[off], len);