[analyzer] What do I need to pay attention to when I convert 'CastToStructChecker' from AST-based check to path-sensitive check?

Answer myself.

I have encountered some problems in the process of implementation, one of the problems comes from CastExpr with ‘CK_BaseToDerived’ kind.

For the ‘CK_BaseToDerived’, analyzer try dynamic cast first, then return if successful, otherwise fall back to the conservative approach.