Generate PG schemas from the Oracle Data Modeler tool?

The best affordable (in this case, free) data modeling tool that I have found is the "Oracle SQL Developer Data Modeler" (http://www.oracle.com/technetwork/developer-tools/datamodeler/overview/index.html). 

The best DBMS (free or otherwise) that I have found is PostgreSQL.

So of course it would be great to be able to connect the Oracle tool to a PG database, so one could forward- and reverse-engineer between the two.  At present, apparently the Oracle tool only natively connects with Oracle, DB2, and SQL Server.

So I'm wondering if anybody knows of a utility or an Oracle Data Modeler add-on that will take some dialect of SQL DDL that that tool generates and turn it into PG-readable SQL.

I get it from the list at https://wiki.postgresql.org/wiki/Converting_from_other_Databases_to_PostgreSQL that there are tools that do something more ambitious: read schemas from actual Oracle databases and implement them as schemas in actual PG databases.  What I need is more modest than that: a tool that inputs a file of DDL from the Oracle Data Modeler tool and outputs that DDL in PG syntax.

~ Thanks for any leads you can provide

~ Ken