codeql/python/ql/test/library-tests/PointsTo/customise/test.ql

import python
import semmle.python.types.Extensions

/* Customise: Claim any function called has_type_XXX return any class 
 * whose name matches XXX
 */
class HasTypeFact extends CustomPointsToOriginFact {

    HasTypeFact() {
        exists(FunctionObject func, string name |
            func.getACall() = this  and
            name = func.getName() and
            name.prefix("has_type_".length()) = "has_type_"
        )
    }

    override predicate pointsTo(Object value, ClassObject cls) {
        exists(FunctionObject func, string name |
            func.getACall() = this  and
            name = func.getName() and
            name.prefix("has_type_".length()) = "has_type_" |
            cls.getName() = name.suffix("has_type_".length())
        ) and
        value = this
    }

}


from int line, ControlFlowNode f, Object o, ClassObject c
where f.getLocation().getStartLine() = line and 
  exists(Comment ct | ct.getLocation().getStartLine() < line) and
  f.refersTo(o, c, _)
select line, f.toString(), o.toString(), c.toString()