Re: [RFA] fix ref counting of inferior_to_inferior_object

[Tom Tromey <tromey@redhat.com>]

>>>>> "Doug" == Doug Evans <dje@google.com> writes:

Doug> While adding an inferior attribute to the newobjfile event,
Doug> I noticed inferior_to_inferior_object sometimes returns (AFAICT)
Doug> a new reference and sometimes returns a borrowed reference.

The current code is maybe weird but I think it isn't incorrect.  That
said it is fine to change it as well.

The current model is that the Python object mirroring the inferior
clears the inferior->Python mapping when it is finally destroyed.
If the Python code then requests the Python object for that inferior
again, a new object is created.  This is "ok" because the Inferior
object doesn't carry any user state.

Doug>  /* Return a reference to the Python object of type Inferior
Doug>     representing INFERIOR.  If the object has already been created,
Doug> -   return it and increment the reference count,  otherwise, create it.
Doug> +   return it,  otherwise create it.  The result is a borrowed reference.
Doug>     Return NULL on failure.  */

This change requires a CPYCHECKER_RETURNS_BORROWED_REF annotation on the
declaration of inferior_to_inferior_object.

Tom