It appears to build an AST from the code object on the generator, and then translate to SQL.

https://github.com/ponyorm/pony/blob/orm/pony/orm/decompilin...

https://github.com/ponyorm/pony/blob/orm/pony/orm/asttransla...

Pony gets the code object from a generator, decompiles it to a Python AST and then translates it to a SQL abstract tree.