Hi John,
On 26/10/2017 2:03 PM, John Rose wrote:
On Oct 25, 2017, at 8:54 PM, David Holmes <david.hol...@oracle.com> wrote:
Though I still feel uncomfortable lying about the nest-host. I don't see what
usecases would be served by doing that. Other than informational uses, I can't
see a reason to actually identify the nest-host which would not be impacted by
lying about that identity. The only truly useful query is for nestmate access
and that doesn't need to expose the identity of the nest-host and
conservatively rejects access if anything goes wrong.
I'm sympathetic to this, but that implies that getNestHost should return null
rather than this for a non-nesty class. I think it's more valuable that
getNestHost
return 'this' for non-nesty classes, and therefore also for broken-nest classes.
Ok. The JVMS is proposed to state:
"A class or interface without a NestHost attribute belongs to the nest
hosted by itself."
That covers top-level classes and all types compiled with an earlier
version of javac. If we consider a class with an unresolvable, or
otherwise invalid, NestHost attribute, as-if it had no NestHost
attribute, then returning "this" is the natural response for that case.
Bottom line for my personal preferences:
- hasNestMateAccess: never throws, always returns true or false
Yes!
Okay.
- getNestHost(): throw if the host isn't there or else a membership validation
check fails
See above.
getNestHost() won't throw, as above.
Suggestion: also add getValidatedNestHost() that can throw?
- getNestMembers(): throw if any nest member isn't there or a membership
validation check fails
As I said before, I don't mind this choice. Especially if we have
hasNestMateAccess.
Okay. getNestMembers() will throw.
Now the question is what to throw? Dan's spec change for the access
checking allows resolution/linkage errors (and VME) to pass through, and
specifies IllegalAccessError for an invalid nest membership claim. The
IAE makes sense in the context of an access check - though could also be
ICCE.
But in the context of the reflection API, getNestMembers or
getValidatedNestHost, IllegalAccessError doesn't really make sense -
we're not trying to access anything. ICCE seems more fitting there.
Thanks,
David
Cheers,
David
