CodeQL library for Java
codeql/java-all 0.3.5 (changelog, source)

Member predicate RegexString::charSet

Holds if there is a top-level character class beginning at start (inclusive) and ending at end (exclusive)

For now, nested character classes are approximated by only considering the top-level class for parsing. This leads to very similar results for ReDoS queries.

predicate charSet(int start, int end)