-keep file_types

   Specifies which files to retain. To produce the object modules, the
   IDL compiler first creates C source modules, then invokes the
   target C compiler to produce object modules, and finally, deletes
   the C source modules.  If you do not use -keep, only the object
   modules are saved.

   The file types are as follows:

   none    Does not save the C source or the object modules. Does not
           invoke the C compiler.

   c_source
           Saves only the C source modules. Does not invoke the C
           compiler.

   object  Saves only the object modules.

   all     Saves both the C source and the object modules.