RFR(XS): 8144852: Corrupted oop in nmethod

[Vladimir Ivanov]

Sorry for the late response, Dean.

 >
> I thought of that, but didn't want to add
> print_value_on_maybe_null_or_non_oop :-)
Frankly speaking, I don't see much value in 
oopDesc::print_value_on_maybe_null vs oopDesc::print_value_on 
separation. So, I'm in favor of just enhancing current versions and not 
introducing new methods/longer names :-)

>
> If you feel strongly about that, then I should probably get input from
> runtime too, since I think they own that code.
I don't have a strong opinion here, but it definitely looks cleaner.

>
>> Also, the following is slightly misleading since metadata pointers
>> aren't oops:
>>  void nmethod::print_recorded_metadata() {
>> +    if (m == (Metadata*)Universe::non_oop_word()) {
>> +      tty->print("non-oop word");
>>
>
> Would "non-metadata word" be better?
Yes.

Best regards,
Vladimir Ivanov

>>
>> On 12/11/15 6:36 AM, Dean Long wrote:
>>> https://bugs.openjdk.java.net/browse/JDK-8144852
>>> http://cr.openjdk.java.net/~dlong//8144852/webrev/
>>>
>>> The fix for [1] introduced new functions nmethod::print_recorded_oops
>>> and nmethod::print_recorded_metadata that print all oop and metadata
>>> values in an nmethod.  Currently NULL values are handled OK, but
>>> Universe::non_oop_word values cause a crash.
>>>
>>> (This bug is marked confidential because it was reported against one of
>>> our closed ports.)
>>>
>>> dl
>>>
>>> [1]     JDK-8072008: Emit direct call instead of linkTo* for recursive
>>> indy/MH.invoke* calls
>